0 files changed, 0 insertions, 0 deletions
diff --git a/.dir-locals.el b/.dir-locals.el
new file mode 100644
index 0000000000..8f4b96445c
--- /dev/null
+++ b/.dir-locals.el
@@ -0,0 +1,39 @@
+;; Copyright (c) 2018 Urabe, Shyouhei.  All rights reserved.
+;;
+;; This file is a part of  the programming language Ruby.  Permission is hereby
+;; granted, to either  redistribute and/or modify this file,  provided that the
+;; conditions mentioned  in the  file COPYING  are met.   Consult the  file for
+;; details.
+
+((nil .
+     ((indent-tabs-mode . nil)
+      (require-final-newline . t)
+      (tab-width . 8)
+      (show-trailing-whitespace . t)
+      (whitespace-line-column . 80))) ;; See also [Misc #12277]
+
+ ;; (bat-mode . ((buffer-file-coding-system . utf-8-dos)))
+
+ (ruby-mode . ((ruby-indent-level . 2)))
+
+ (rdoc-mode . ((fill-column . 74)))
+
+ (yaml-mode . ((yaml-indent-offset . 2)))
+
+ (makefile-mode . ((indent-tabs-mode . t)))
+
+ (c-mode . ((c-file-style . "ruby")))
+
+ (c++-mode . ((c-file-style . "ruby")))
+
+ (change-log-mode .
+     ((buffer-file-coding-system . us-ascii)
+      (indent-tabs-mode . t)
+      (change-log-indent-text . 2)
+      (add-log-time-format . (lambda (&optional x y)
+        (let* ((time (or x (current-time)))
+	       (system-time-locale "C")
+	       (diff (+ (cadr time) 32400))
+	       (lo (% diff 65536))
+	       (hi (+ (car time) (/ diff 65536))))
+        (format-time-string "%a %b %e %H:%M:%S %Y" (list hi lo) t)))))))
diff --git a/.document b/.document
new file mode 100644
index 0000000000..8616203552
--- /dev/null
+++ b/.document
@@ -0,0 +1,46 @@
+# This file determines which files in the
+# Ruby hierarchy will be processed by the RDoc
+# tool when it is given the top-level directory
+# as an argument
+
+# Process all the C source files
+*.c
+*.y
+
+# prelude
+prelude.rb
+rbconfig.rb
+array.rb
+ast.rb
+dir.rb
+gc.rb
+integer.rb
+io.rb
+kernel.rb
+pack.rb
+trace_point.rb
+warning.rb
+ractor.rb
+
+# the lib/ directory (which has its own .document file)
+lib
+
+# and some of the ext/ directory (which has its own .document file)
+ext
+
+# rdoc files
+NEWS.md
+
+README.md
+README.ja.md
+
+COPYING
+COPYING.ja
+CONTRIBUTING.md
+
+LEGAL
+
+# win32/README.win32 linked from README.md
+win32
+
+doc
diff --git a/.editorconfig b/.editorconfig
new file mode 100644
index 0000000000..4633a7acae
--- /dev/null
+++ b/.editorconfig
@@ -0,0 +1,30 @@
+root = true
+
+[*]
+end_of_line = lf
+indent_size = 4
+indent_style = space
+insert_final_newline = true
+tab_width = 8
+trim_trailing_whitespace = true
+
+[*.bat]
+end_of_line = crlf
+
+[*.gemspec]
+indent_size = 2
+
+[*.rb]
+indent_size = 2
+
+[*.yml]
+indent_size = 2
+
+[{*[Mm]akefile*,*.mak,*.mk,depend}]
+indent_style = tab
+
+[enc/*]
+indent_size = 2
+
+[reg*.[ch]]
+indent_size = 2
diff --git a/.gdbinit b/.gdbinit
new file mode 100644
index 0000000000..49380951b8
--- /dev/null
+++ b/.gdbinit
@@ -0,0 +1,1351 @@
+set startup-with-shell off
+
+define hook-run
+  set $color_type = 0
+  set $color_highlite = 0
+  set $color_end = 0
+end
+
+define ruby_gdb_init
+  if !$color_type
+    set $color_type = "\033[31m"
+  end
+  if !$color_highlite
+    set $color_highlite = "\033[36m"
+  end
+  if !$color_end
+    set $color_end = "\033[m"
+  end
+  if ruby_dummy_gdb_enums.special_consts
+  end
+end
+
+# set prompt \033[36m(gdb)\033[m\040
+
+define rp
+  ruby_gdb_init
+  if (VALUE)($arg0) & RUBY_FIXNUM_FLAG
+    printf "FIXNUM: %ld\n", (long)($arg0) >> 1
+  else
+  if ((VALUE)($arg0) & ~(~(VALUE)0<<RUBY_SPECIAL_SHIFT)) == RUBY_SYMBOL_FLAG
+    set $id = (($arg0) >> RUBY_SPECIAL_SHIFT)
+    printf "%sSYMBOL%s: ", $color_type, $color_end
+    rp_id $id
+  else
+  if ($arg0) == RUBY_Qfalse
+    echo false\n
+  else
+  if ($arg0) == RUBY_Qtrue
+    echo true\n
+  else
+  if ($arg0) == RUBY_Qnil
+    echo nil\n
+  else
+  if ($arg0) == RUBY_Qundef
+    echo undef\n
+  else
+  if (VALUE)($arg0) & RUBY_IMMEDIATE_MASK
+    if ((VALUE)($arg0) & RUBY_FLONUM_MASK) == RUBY_FLONUM_FLAG
+      printf "%sFLONUM%s: %g\n", $color_type, $color_end, (double)rb_float_value($arg0)
+    else
+      echo immediate\n
+    end
+  else
+  set $flags = ((struct RBasic*)($arg0))->flags
+  if ($flags & RUBY_FL_PROMOTED) == RUBY_FL_PROMOTED
+    printf "[PROMOTED] "
+  end
+  if ($flags & RUBY_T_MASK) == RUBY_T_NONE
+    printf "%sT_NONE%s: ", $color_type, $color_end
+    print (struct RBasic *)($arg0)
+  else
+  if ($flags & RUBY_T_MASK) == RUBY_T_NIL
+    printf "%sT_NIL%s: ", $color_type, $color_end
+    print (struct RBasic *)($arg0)
+  else
+  if ($flags & RUBY_T_MASK) == RUBY_T_OBJECT
+    printf "%sT_OBJECT%s: ", $color_type, $color_end
+    print ((struct RObject *)($arg0))->basic
+    if ($flags & ROBJECT_EMBED)
+      print/x *((VALUE*)((struct RObject*)($arg0))->as.ary) @ (ROBJECT_EMBED_LEN_MAX+0)
+    else
+      print (((struct RObject *)($arg0))->as.heap)
+      if (((struct RObject*)($arg0))->as.heap.numiv) > 0
+        print/x *(((struct RObject*)($arg0))->as.heap.ivptr) @ (((struct RObject*)($arg0))->as.heap.numiv)
+      end
+    end
+  else
+  if ($flags & RUBY_T_MASK) == RUBY_T_CLASS
+    printf "%sT_CLASS%s%s: ", $color_type, ($flags & RUBY_FL_SINGLETON) ? "*" : "", $color_end
+    rp_class $arg0
+  else
+  if ($flags & RUBY_T_MASK) == RUBY_T_ICLASS
+    printf "%sT_ICLASS%s: ", $color_type, $color_end
+    rp_class $arg0
+  else
+  if ($flags & RUBY_T_MASK) == RUBY_T_MODULE
+    printf "%sT_MODULE%s: ", $color_type, $color_end
+    rp_class $arg0
+  else
+  if ($flags & RUBY_T_MASK) == RUBY_T_FLOAT
+    printf "%sT_FLOAT%s: %.16g ", $color_type, $color_end, (((struct RFloat*)($arg0))->float_value)
+    print (struct RFloat *)($arg0)
+  else
+  if ($flags & RUBY_T_MASK) == RUBY_T_STRING
+    printf "%sT_STRING%s: ", $color_type, $color_end
+    rp_string $arg0 $flags
+  else
+  if ($flags & RUBY_T_MASK) == RUBY_T_REGEXP
+    set $regsrc = ((struct RRegexp*)($arg0))->src
+    set $rsflags = ((struct RBasic*)$regsrc)->flags
+    printf "%sT_REGEXP%s: ", $color_type, $color_end
+    set $len = ($rsflags & RUBY_FL_USER1) ? \
+            ((struct RString*)$regsrc)->as.heap.len : \
+            (($rsflags & (RUBY_FL_USER2|RUBY_FL_USER3|RUBY_FL_USER4|RUBY_FL_USER5|RUBY_FL_USER6)) >> RUBY_FL_USHIFT+2)
+    set print address off
+    output *(char *)(($rsflags & RUBY_FL_USER1) ? \
+	    ((struct RString*)$regsrc)->as.heap.ptr : \
+	    ((struct RString*)$regsrc)->as.ary) @ $len
+    set print address on
+    printf " len:%ld ", $len
+    if $flags & RUBY_FL_USER6
+      printf "(none) "
+    end
+    if $flags & RUBY_FL_USER5
+      printf "(literal) "
+    end
+    if $flags & RUBY_FL_USER4
+      printf "(fixed) "
+    end
+    printf "encoding:%d ", ($flags & RUBY_ENCODING_MASK) >> RUBY_ENCODING_SHIFT
+    print (struct RRegexp *)($arg0)
+  else
+  if ($flags & RUBY_T_MASK) == RUBY_T_ARRAY
+    if ($flags & RUBY_FL_USER1)
+      set $len = (($flags & (RUBY_FL_USER3|RUBY_FL_USER4)) >> (RUBY_FL_USHIFT+3))
+      printf "%sT_ARRAY%s: len=%ld ", $color_type, $color_end, $len
+      printf "(embed) "
+      if ($len == 0)
+	printf "{(empty)} "
+      else
+	print/x *((VALUE*)((struct RArray*)($arg0))->as.ary) @ $len
+	printf " "
+      end
+    else
+      set $len = ((struct RArray*)($arg0))->as.heap.len
+      printf "%sT_ARRAY%s: len=%ld ", $color_type, $color_end, $len
+      if ($flags & RUBY_FL_USER2)
+	printf "(shared) shared="
+	output/x ((struct RArray*)($arg0))->as.heap.aux.shared_root
+	printf " "
+      else
+	printf "(ownership) capa=%ld ", ((struct RArray*)($arg0))->as.heap.aux.capa
+      end
+      if ($len == 0)
+	printf "{(empty)} "
+      else
+	print/x *((VALUE*)((struct RArray*)($arg0))->as.heap.ptr) @ $len
+	printf " "
+      end
+    end
+    print (struct RArray *)($arg0)
+  else
+  if ($flags & RUBY_T_MASK) == RUBY_T_FIXNUM
+    printf "%sT_FIXNUM%s: ", $color_type, $color_end
+    print (struct RBasic *)($arg0)
+  else
+  if ($flags & RUBY_T_MASK) == RUBY_T_HASH
+    printf "%sT_HASH%s: ", $color_type, $color_end,
+    if (((struct RHash *)($arg0))->basic.flags & RHASH_ST_TABLE_FLAG)
+      printf "st len=%ld ", ((struct RHash *)($arg0))->as.st->num_entries
+    else
+      printf "li len=%ld bound=%ld ", \
+        ((((struct RHash *)($arg0))->basic.flags & RHASH_AR_TABLE_SIZE_MASK) >> RHASH_AR_TABLE_SIZE_SHIFT), \
+        ((((struct RHash *)($arg0))->basic.flags & RHASH_AR_TABLE_BOUND_MASK) >> RHASH_AR_TABLE_BOUND_SHIFT)
+    end
+    print (struct RHash *)($arg0)
+  else
+  if ($flags & RUBY_T_MASK) == RUBY_T_STRUCT
+    set $len = (($flags & (RUBY_FL_USER1|RUBY_FL_USER2)) ? \
+       ($flags & (RUBY_FL_USER1|RUBY_FL_USER2)) >> (RUBY_FL_USHIFT+1) : \
+       ((struct RStruct *)($arg0))->as.heap.len)
+    printf "%sT_STRUCT%s: len=%ld ", $color_type, $color_end, $len
+    print (struct RStruct *)($arg0)
+    output/x *(($flags & (RUBY_FL_USER1|RUBY_FL_USER2)) ? \
+              ((struct RStruct *)($arg0))->as.ary : \
+              ((struct RStruct *)($arg0))->as.heap.ptr) @ $len
+  else
+  if ($flags & RUBY_T_MASK) == RUBY_T_BIGNUM
+    rp_bignum $arg0
+  else
+  if ($flags & RUBY_T_MASK) == RUBY_T_RATIONAL
+    printf "%sT_RATIONAL%s: ", $color_type, $color_end
+    print (struct RRational *)($arg0)
+  else
+  if ($flags & RUBY_T_MASK) == RUBY_T_COMPLEX
+    printf "%sT_COMPLEX%s: ", $color_type, $color_end
+    print (struct RComplex *)($arg0)
+  else
+  if ($flags & RUBY_T_MASK) == RUBY_T_FILE
+    printf "%sT_FILE%s: ", $color_type, $color_end
+    print (struct RFile *)($arg0)
+    output *((struct RFile *)($arg0))->fptr
+    printf "\n"
+  else
+  if ($flags & RUBY_T_MASK) == RUBY_T_TRUE
+    printf "%sT_TRUE%s: ", $color_type, $color_end
+    print (struct RBasic *)($arg0)
+  else
+  if ($flags & RUBY_T_MASK) == RUBY_T_FALSE
+    printf "%sT_FALSE%s: ", $color_type, $color_end
+    print (struct RBasic *)($arg0)
+  else
+  if ($flags & RUBY_T_MASK) == RUBY_T_DATA
+    if ((struct RTypedData *)($arg0))->typed_flag == 1
+      printf "%sT_DATA%s(%s): ", $color_type, $color_end, ((struct RTypedData *)($arg0))->type->wrap_struct_name
+      print (struct RTypedData *)($arg0)
+    else
+      printf "%sT_DATA%s: ", $color_type, $color_end
+      print (struct RData *)($arg0)
+    end
+  else
+  if ($flags & RUBY_T_MASK) == RUBY_T_MATCH
+    printf "%sT_MATCH%s: ", $color_type, $color_end
+    print (struct RMatch *)($arg0)
+  else
+  if ($flags & RUBY_T_MASK) == RUBY_T_SYMBOL
+    printf "%sT_SYMBOL%s: ", $color_type, $color_end
+    print (struct RSymbol *)($arg0)
+    set $id_type = ((struct RSymbol *)($arg0))->id & RUBY_ID_SCOPE_MASK
+    if $id_type == RUBY_ID_LOCAL
+      printf "l"
+    else
+    if $id_type == RUBY_ID_INSTANCE
+      printf "i"
+    else
+    if $id_type == RUBY_ID_GLOBAL
+      printf "G"
+    else
+    if $id_type == RUBY_ID_ATTRSET
+      printf "a"
+    else
+    if $id_type == RUBY_ID_CONST
+      printf "C"
+    else
+    if $id_type == RUBY_ID_CLASS
+      printf "c"
+    else
+      printf "j"
+    end
+    end
+    end
+    end
+    end
+    end
+    set $id_fstr = ((struct RSymbol *)($arg0))->fstr
+    rp_string $id_fstr
+  else
+  if ($flags & RUBY_T_MASK) == RUBY_T_UNDEF
+    printf "%sT_UNDEF%s: ", $color_type, $color_end
+    print (struct RBasic *)($arg0)
+  else
+  if ($flags & RUBY_T_MASK) == RUBY_T_IMEMO
+    printf "%sT_IMEMO%s(", $color_type, $color_end
+    output (enum imemo_type)(($flags>>RUBY_FL_USHIFT)&RUBY_IMEMO_MASK)
+    printf "): "
+    rp_imemo $arg0
+  else
+  if ($flags & RUBY_T_MASK) == RUBY_T_NODE
+    printf "%sT_NODE%s(", $color_type, $color_end
+    output (enum node_type)(($flags&RUBY_NODE_TYPEMASK)>>RUBY_NODE_TYPESHIFT)
+    printf "): "
+    print *(NODE *)($arg0)
+  else
+  if ($flags & RUBY_T_MASK) == RUBY_T_ZOMBIE
+    printf "%sT_ZOMBIE%s: ", $color_type, $color_end
+    print (struct RData *)($arg0)
+  else
+  if ($flags & RUBY_T_MASK) == RUBY_T_MOVED
+    printf "%sT_MOVED%s: ", $color_type, $color_end
+    print *(struct RMoved *)$arg0
+  else
+    printf "%sunknown%s: ", $color_type, $color_end
+    print (struct RBasic *)($arg0)
+  end
+  end
+  end
+  end
+  end
+  end
+  end
+  end
+  end
+  end
+  end
+  end
+  end
+  end
+  end
+  end
+  end
+  end
+  end
+  end
+  end
+  end
+  end
+  end
+  end
+  end
+  end
+  end
+  end
+  end
+  end
+  end
+  end
+  end
+end
+document rp
+  Print a Ruby's VALUE.
+end
+
+define rp_id
+  set $id = (ID)$arg0
+  if $id == '!' || $id == '+' || $id == '-' || $id == '*' || $id == '/' || $id == '%' || $id == '<' || $id == '>' || $id == '`'
+    printf "(:%c)\n", $id
+  else
+  if $id == idDot2
+    printf "(:..)\n"
+  else
+  if $id == idDot3
+    printf "(:...)\n"
+  else
+  if $id == idUPlus
+    printf "(:+@)\n"
+  else
+  if $id == idUMinus
+    printf "(:-@)\n"
+  else
+  if $id == idPow
+    printf "(:**)\n"
+  else
+  if $id == idCmp
+    printf "(:<=>)\n"
+  else
+  if $id == idLTLT
+    printf "(:<<)\n"
+  else
+  if $id == idGTGT
+    printf "(:>>)\n"
+  else
+  if $id == idLE
+    printf "(:<=)\n"
+  else
+  if $id == idGE
+    printf "(:>=)\n"
+  else
+  if $id == idEq
+    printf "(:==)\n"
+  else
+  if $id == idEqq
+    printf "(:===)\n"
+  else
+  if $id == idNeq
+    printf "(:!=)\n"
+  else
+  if $id == idEqTilde
+    printf "(:=~)\n"
+  else
+  if $id == idNeqTilde
+    printf "(:!~)\n"
+  else
+  if $id == idAREF
+    printf "(:[])\n"
+  else
+  if $id == idASET
+    printf "(:[]=)\n"
+  else
+  if $id == idCOLON2
+    printf "(:'::')\n"
+  else
+  if $id == idANDOP
+    printf "(:&&)\n"
+  else
+  if $id == idOROP
+    printf "(:||)\n"
+  else
+  if $id == idANDDOT
+    printf "(:&.)\n"
+  else
+    if $id <= tLAST_OP_ID
+      printf "O"
+    else
+      set $id_type = $id & RUBY_ID_SCOPE_MASK
+      if $id_type == RUBY_ID_LOCAL
+        printf "l"
+      else
+      if $id_type == RUBY_ID_INSTANCE
+        printf "i"
+      else
+      if $id_type == RUBY_ID_GLOBAL
+        printf "G"
+      else
+      if $id_type == RUBY_ID_ATTRSET
+        printf "a"
+      else
+      if $id_type == RUBY_ID_CONST
+        printf "C"
+      else
+      if $id_type == RUBY_ID_CLASS
+        printf "c"
+      else
+        printf "j"
+      end
+      end
+      end
+      end
+      end
+      end
+    end
+    printf "(%ld): ", $id
+    print_id $id
+    echo \n
+  end
+  end
+  end
+  end
+  end
+  end
+  end
+  end
+  end
+  end
+  end
+  end
+  end
+  end
+  end
+  end
+  end
+  end
+  end
+  end
+  end
+  end
+end
+document rp_id
+  Print an ID.
+end
+
+define output_string
+  set $flags = ((struct RBasic*)($arg0))->flags
+  set $len = ($flags & RUBY_FL_USER1) ? \
+          ((struct RString*)($arg0))->as.heap.len : \
+          (($flags & (RUBY_FL_USER2|RUBY_FL_USER3|RUBY_FL_USER4|RUBY_FL_USER5|RUBY_FL_USER6)) >> RUBY_FL_USHIFT+2)
+  if $len > 0
+    output *(char *)(($flags & RUBY_FL_USER1) ? \
+	    ((struct RString*)($arg0))->as.heap.ptr : \
+	    ((struct RString*)($arg0))->as.ary) @ $len
+  else
+    output ""
+  end
+end
+
+define print_string
+  set $flags = ((struct RBasic*)($arg0))->flags
+  set $len = ($flags & RUBY_FL_USER1) ? \
+          ((struct RString*)($arg0))->as.heap.len : \
+          (($flags & (RUBY_FL_USER2|RUBY_FL_USER3|RUBY_FL_USER4|RUBY_FL_USER5|RUBY_FL_USER6)) >> RUBY_FL_USHIFT+2)
+  if $len > 0
+    printf "%s", *(char *)(($flags & RUBY_FL_USER1) ? \
+	    ((struct RString*)($arg0))->as.heap.ptr : \
+	    ((struct RString*)($arg0))->as.ary) @ $len
+  end
+end
+
+define rp_string
+  output_string $arg0
+  printf " bytesize:%ld ", $len
+  if !($flags & RUBY_FL_USER1)
+    printf "(embed) "
+  else
+    if ($flags & RUBY_FL_USER2)
+      printf "(shared) "
+    end
+    if ($flags & RUBY_FL_USER3)
+      printf "(assoc) "
+    end
+  end
+  printf "encoding:%d ", ($flags & RUBY_ENCODING_MASK) >> RUBY_ENCODING_SHIFT
+  if ($flags & RUBY_ENC_CODERANGE_MASK) == 0
+    printf "coderange:unknown "
+  else
+  if ($flags & RUBY_ENC_CODERANGE_MASK) == RUBY_ENC_CODERANGE_7BIT
+    printf "coderange:7bit "
+  else
+  if ($flags & RUBY_ENC_CODERANGE_MASK) == RUBY_ENC_CODERANGE_VALID
+    printf "coderange:valid "
+  else
+    printf "coderange:broken "
+  end
+  end
+  end
+  print (struct RString *)($arg0)
+end
+document rp_string
+  Print the content of a String.
+end
+
+define rp_bignum
+  set $flags = ((struct RBignum*)($arg0))->basic.flags
+  set $len = (($flags & RUBY_FL_USER2) ? \
+       ($flags & (RUBY_FL_USER5|RUBY_FL_USER4|RUBY_FL_USER3)) >> (RUBY_FL_USHIFT+3) : \
+       ((struct RBignum*)($arg0))->as.heap.len)
+  printf "%sT_BIGNUM%s: sign=%d len=%ld ", $color_type, $color_end, \
+         (($flags & RUBY_FL_USER1) != 0), $len
+  if $flags & RUBY_FL_USER2
+    printf "(embed) "
+  end
+  print (struct RBignum *)($arg0)
+  set $ptr = (($flags & RUBY_FL_USER2) ? \
+              ((struct RBignum*)($arg0))->as.ary : \
+              ((struct RBignum*)($arg0))->as.heap.digits)
+  set $len = $len-1
+  printf "0x%x", $ptr[$len]
+  while $len > 0
+    set $len = $len-1
+    set $val = $ptr[$len]
+    set $w = sizeof($ptr[0])
+    printf "_"
+    if $w > 8
+      printf "%.32x", $val
+    else
+    if $w > 4
+      printf "%.16x", $val
+    else
+    if $w > 2
+      printf "%.8x", $val
+    else
+    if $w > 1
+      printf "%.4x", $val
+    else
+      printf "%.2x", $val
+    end
+    end
+    end
+    end
+  end
+  printf "\n"
+end
+document rp_bignum
+  Print the content of a Bignum.
+end
+
+define rp_class
+  printf "(struct RClass *) %p", (void*)$arg0
+  if ((struct RClass *)($arg0))->ptr.origin_ != $arg0
+    printf " -> %p", ((struct RClass *)($arg0))->ptr.origin_
+  end
+  printf "\n"
+  rb_classname $arg0
+  print/x *(struct RClass *)($arg0)
+  print *((struct RClass *)($arg0))->ptr
+end
+document rp_class
+  Print the content of a Class/Module.
+end
+
+define rp_imemo
+  set $flags = (enum imemo_type)((((struct RBasic *)($arg0))->flags >> RUBY_FL_USHIFT) & RUBY_IMEMO_MASK)
+  if $flags == imemo_cref
+    printf "(rb_cref_t *) %p\n", (void*)$arg0
+    print *(rb_cref_t *)$arg0
+  else
+  if $flags == imemo_svar
+    printf "(struct vm_svar *) %p\n", (void*)$arg0
+    print *(struct vm_svar *)$arg0
+  else
+  if $flags == imemo_throw_data
+    printf "(struct vm_throw_data *) %p\n", (void*)$arg0
+    print *(struct vm_throw_data *)$arg0
+  else
+  if $flags == imemo_ifunc
+    printf "(struct vm_ifunc *) %p\n", (void*)$arg0
+    print *(struct vm_ifunc *)$arg0
+  else
+  if $flags == imemo_memo
+    printf "(struct MEMO *) %p\n", (void*)$arg0
+    print *(struct MEMO *)$arg0
+  else
+  if $flags == imemo_ment
+    printf "(rb_method_entry_t *) %p\n", (void*)$arg0
+    print *(rb_method_entry_t *)$arg0
+  else
+  if $flags == imemo_iseq
+    printf "(rb_iseq_t *) %p\n", (void*)$arg0
+    print *(rb_iseq_t *)$arg0
+  else
+    printf "(struct RIMemo *) %p\n", (void*)$arg0
+    print *(struct RIMemo *)$arg0
+  end
+  end
+  end
+  end
+  end
+  end
+  end
+end
+document rp_imemo
+  Print the content of a memo
+end
+
+define nd_type
+  print (enum node_type)((((NODE*)($arg0))->flags&RUBY_NODE_TYPEMASK)>>RUBY_NODE_TYPESHIFT)
+end
+document nd_type
+  Print a Ruby' node type.
+end
+
+define nd_file
+  print ((NODE*)($arg0))->nd_file
+end
+document nd_file
+  Print the source file name of a node.
+end
+
+define nd_line
+  print ((unsigned int)((((NODE*)($arg0))->flags>>RUBY_NODE_LSHIFT)&RUBY_NODE_LMASK))
+end
+document nd_line
+  Print the source line number of a node.
+end
+
+# Print members of ruby node.
+
+define nd_head
+  printf "%su1.node%s: ", $color_highlite, $color_end
+  rp ($arg0).u1.node
+end
+
+define nd_alen
+  printf "%su2.argc%s: ", $color_highlite, $color_end
+  p ($arg0).u2.argc
+end
+
+define nd_next
+  printf "%su3.node%s: ", $color_highlite, $color_end
+  rp ($arg0).u3.node
+end
+
+
+define nd_cond
+  printf "%su1.node%s: ", $color_highlite, $color_end
+  rp ($arg0).u1.node
+end
+
+define nd_body
+  printf "%su2.node%s: ", $color_highlite, $color_end
+  rp ($arg0).u2.node
+end
+
+define nd_else
+  printf "%su3.node%s: ", $color_highlite, $color_end
+  rp ($arg0).u3.node
+end
+
+
+define nd_orig
+  printf "%su3.value%s: ", $color_highlite, $color_end
+  rp ($arg0).u3.value
+end
+
+
+define nd_resq
+  printf "%su2.node%s: ", $color_highlite, $color_end
+  rp ($arg0).u2.node
+end
+
+define nd_ensr
+  printf "%su3.node%s: ", $color_highlite, $color_end
+  rp ($arg0).u3.node
+end
+
+
+define nd_1st
+  printf "%su1.node%s: ", $color_highlite, $color_end
+  rp ($arg0).u1.node
+end
+
+define nd_2nd
+  printf "%su2.node%s: ", $color_highlite, $color_end
+  rp ($arg0).u2.node
+end
+
+
+define nd_stts
+  printf "%su1.node%s: ", $color_highlite, $color_end
+  rp ($arg0).u1.node
+end
+
+
+define nd_entry
+  printf "%su3.entry%s: ", $color_highlite, $color_end
+  p ($arg0).u3.entry
+end
+
+define nd_vid
+  printf "%su1.id%s: ", $color_highlite, $color_end
+  p ($arg0).u1.id
+end
+
+define nd_cflag
+  printf "%su2.id%s: ", $color_highlite, $color_end
+  p ($arg0).u2.id
+end
+
+define nd_cval
+  printf "%su3.value%s: ", $color_highlite, $color_end
+  rp ($arg0).u3.value
+end
+
+define nd_tbl
+  printf "%su1.tbl%s: ", $color_highlite, $color_end
+  p ($arg0).u1.tbl
+end
+
+
+define nd_var
+  printf "%su1.node%s: ", $color_highlite, $color_end
+  rp ($arg0).u1.node
+end
+
+define nd_ibdy
+  printf "%su2.node%s: ", $color_highlite, $color_end
+  rp ($arg0).u2.node
+end
+
+define nd_iter
+  printf "%su3.node%s: ", $color_highlite, $color_end
+  rp ($arg0).u3.node
+end
+
+
+define nd_value
+  printf "%su2.node%s: ", $color_highlite, $color_end
+  rp ($arg0).u2.node
+end
+
+define nd_aid
+  printf "%su3.id%s: ", $color_highlite, $color_end
+  p ($arg0).u3.id
+end
+
+
+define nd_lit
+  printf "%su1.value%s: ", $color_highlite, $color_end
+  rp ($arg0).u1.value
+end
+
+define nd_rest
+  printf "%su2.argc%s: ", $color_highlite, $color_end
+  p ($arg0).u2.argc
+end
+
+define nd_opt
+  printf "%su1.node%s: ", $color_highlite, $color_end
+  rp ($arg0).u1.node
+end
+
+
+define nd_recv
+  printf "%su1.node%s: ", $color_highlite, $color_end
+  rp ($arg0).u1.node
+end
+
+define nd_mid
+  printf "%su2.id%s: ", $color_highlite, $color_end
+  p ($arg0).u2.id
+end
+
+define nd_args
+  printf "%su3.node%s: ", $color_highlite, $color_end
+  rp ($arg0).u3.node
+end
+
+define nd_defn
+  printf "%su3.node%s: ", $color_highlite, $color_end
+  rp ($arg0).u3.node
+end
+
+
+define nd_old
+  printf "%su1.id%s: ", $color_highlite, $color_end
+  p ($arg0).u1.id
+end
+
+define nd_new
+  printf "%su2.id%s: ", $color_highlite, $color_end
+  p ($arg0).u2.id
+end
+
+
+define nd_cname
+  printf "%su1.id%s: ", $color_highlite, $color_end
+  p ($arg0).u1.id
+end
+
+define nd_super
+  printf "%su3.node%s: ", $color_highlite, $color_end
+  rp ($arg0).u3.node
+end
+
+
+define nd_modl
+  printf "%su1.id%s: ", $color_highlite, $color_end
+  p ($arg0).u1.id
+end
+
+define nd_clss
+  printf "%su1.value%s: ", $color_highlite, $color_end
+  rp ($arg0).u1.value
+end
+
+
+define nd_beg
+  printf "%su1.node%s: ", $color_highlite, $color_end
+  rp ($arg0).u1.node
+end
+
+define nd_end
+  printf "%su2.node%s: ", $color_highlite, $color_end
+  rp ($arg0).u2.node
+end
+
+define nd_state
+  printf "%su3.state%s: ", $color_highlite, $color_end
+  p ($arg0).u3.state
+end
+
+define nd_rval
+  printf "%su2.value%s: ", $color_highlite, $color_end
+  rp ($arg0).u2.value
+end
+
+
+define nd_nth
+  printf "%su2.argc%s: ", $color_highlite, $color_end
+  p ($arg0).u2.argc
+end
+
+
+define nd_tag
+  printf "%su1.id%s: ", $color_highlite, $color_end
+  p ($arg0).u1.id
+end
+
+define nd_tval
+  printf "%su2.value%s: ", $color_highlite, $color_end
+  rp ($arg0).u2.value
+end
+
+define nd_tree
+  set $buf = (struct RString *)rb_str_buf_new(0)
+  call dump_node((VALUE)($buf), rb_str_tmp_new(0), 0, ($arg0))
+  printf "%s\n", $buf->as.heap.ptr
+end
+
+define rb_p
+  call rb_p($arg0)
+end
+
+define rb_numtable_entry
+  set $rb_numtable_tbl = $arg0
+  set $rb_numtable_id = (st_data_t)$arg1
+  set $rb_numtable_key = 0
+  set $rb_numtable_rec = 0
+  if $rb_numtable_tbl->entries_packed
+    set $rb_numtable_p = $rb_numtable_tbl->as.packed.bins
+    while $rb_numtable_p && $rb_numtable_p < $rb_numtable_tbl->as.packed.bins+$rb_numtable_tbl->num_entries
+      if $rb_numtable_p.k == $rb_numtable_id
+	set $rb_numtable_key = $rb_numtable_p.k
+	set $rb_numtable_rec = $rb_numtable_p.v
+	set $rb_numtable_p = 0
+      else
+	set $rb_numtable_p = $rb_numtable_p + 1
+      end
+    end
+  else
+    set $rb_numtable_p = $rb_numtable_tbl->as.big.bins[st_numhash($rb_numtable_id) % $rb_numtable_tbl->num_bins]
+    while $rb_numtable_p
+      if $rb_numtable_p->key == $rb_numtable_id
+	set $rb_numtable_key = $rb_numtable_p->key
+	set $rb_numtable_rec = $rb_numtable_p->record
+	set $rb_numtable_p = 0
+      else
+	set $rb_numtable_p = $rb_numtable_p->next
+      end
+    end
+  end
+end
+
+define rb_id2name
+  ruby_gdb_init
+  printf "%sID%s: ", $color_type, $color_end
+  rp_id $arg0
+end
+document rb_id2name
+  Print the name of id
+end
+
+define rb_method_entry
+  set $rb_method_entry_klass = (struct RClass *)$arg0
+  set $rb_method_entry_id = (ID)$arg1
+  set $rb_method_entry_me = (rb_method_entry_t *)0
+  while !$rb_method_entry_me && $rb_method_entry_klass
+    rb_numtable_entry $rb_method_entry_klass->m_tbl_wrapper->tbl $rb_method_entry_id
+    set $rb_method_entry_me = (rb_method_entry_t *)$rb_numtable_rec
+    if !$rb_method_entry_me
+      set $rb_method_entry_klass = (struct RClass *)RCLASS_SUPER($rb_method_entry_klass)
+    end
+  end
+  if $rb_method_entry_me
+    print *$rb_method_entry_klass
+    print *$rb_method_entry_me
+  else
+    echo method not found\n
+  end
+end
+document rb_method_entry
+  Search method entry by class and id
+end
+
+define rb_classname
+  # up to 128bit int
+  set $rb_classname = rb_mod_name($arg0)
+  if $rb_classname != RUBY_Qnil
+    rp $rb_classname
+  else
+    echo anonymous class/module\n
+  end
+end
+
+define rb_ancestors
+  set $rb_ancestors_module = $arg0
+  while $rb_ancestors_module
+    rp_class $rb_ancestors_module
+    set $rb_ancestors_module = RCLASS_SUPER($rb_ancestors_module)
+  end
+end
+document rb_ancestors
+  Print ancestors.
+end
+
+define rb_backtrace
+  call rb_backtrace()
+end
+
+define iseq
+  if ruby_dummy_gdb_enums.special_consts
+  end
+  if ($arg0)->type == ISEQ_ELEMENT_NONE
+    echo [none]\n
+  end
+  if ($arg0)->type == ISEQ_ELEMENT_LABEL
+    print *(LABEL*)($arg0)
+  end
+  if ($arg0)->type == ISEQ_ELEMENT_INSN
+    print *(INSN*)($arg0)
+    if ((INSN*)($arg0))->insn_id != YARVINSN_jump
+      set $i = 0
+      set $operand_size = ((INSN*)($arg0))->operand_size
+      set $operands = ((INSN*)($arg0))->operands
+      while $i < $operand_size
+	rp $operands[$i++]
+      end
+    end
+  end
+  if ($arg0)->type == ISEQ_ELEMENT_ADJUST
+    print *(ADJUST*)($arg0)
+  end
+end
+
+define rb_ps
+  rb_ps_vm ruby_current_vm_ptr
+end
+document rb_ps
+Dump all threads and their callstacks
+end
+
+define rb_ps_vm
+  print $ps_vm = (rb_vm_t*)$arg0
+  set $ps_thread_ln = $ps_vm->living_threads.n.next
+  set $ps_thread_ln_last = $ps_vm->living_threads.n.prev
+  while 1
+    set $ps_thread_th = (rb_thread_t *)$ps_thread_ln
+    set $ps_thread = (VALUE)($ps_thread_th->self)
+    rb_ps_thread $ps_thread
+    if $ps_thread_ln == $ps_thread_ln_last
+      loop_break
+    end
+    set $ps_thread_ln = $ps_thread_ln->next
+  end
+end
+document rb_ps_vm
+Dump all threads in a (rb_vm_t*) and their callstacks
+end
+
+define print_lineno
+  set $cfp = $arg0
+  set $iseq = $cfp->iseq
+  set $pos = $cfp->pc - $iseq->body->iseq_encoded
+  if $pos != 0
+    set $pos = $pos - 1
+  end
+
+  set $index = 0
+  set $size = $iseq->body->insns_info.size
+  set $table = $iseq->body->insns_info.body
+  set $positions = $iseq->body->insns_info.positions
+  #printf "size: %d\n", $size
+  if $size == 0
+  else
+  if $size == 1
+    printf "%d", $table[0].line_no
+  else
+    if $positions
+      # get_insn_info_linear_search
+      set $index = 1
+      while $index < $size
+        #printf "table[%d]: position: %d, line: %d, pos: %d\n", $i, $positions[$i], $table[$i].line_no, $pos
+        if $positions[$index] > $pos
+          loop_break
+        end
+        set $index = $index + 1
+        if $positions[$index] == $pos
+          loop_break
+        end
+      end
+    else
+      # get_insn_info_succinct_bitvector
+      set $sd = $iseq->body->insns_info.succ_index_table
+      set $immediate_table_size = sizeof($sd->imm_part) / sizeof(uint64_t) * 9
+      if $pos < $immediate_table_size
+        set $i = $pos / 9
+        set $j = $pos % 9
+        set $index = ((int)($sd->imm_part[$i] >> ($j * 7))) & 0x7f
+      else
+        set $block_index = ($pos - $immediate_table_size) / 512
+        set $block = &$sd->succ_part[$block_index]
+        set $block_bit_index = ($pos - $immediate_table_size) % 512
+        set $small_block_index = $block_bit_index / 64
+        set $small_block_popcount = $small_block_index == 0 ? 0 : (((int)($block->small_block_ranks >> (($small_block_index - 1) * 9))) & 0x1ff)
+        set $x = $block->bits[$small_block_index] << (63 - $block_bit_index % 64)
+        set $x = ($x & 0x5555555555555555) + ($x >> 1 & 0x5555555555555555)
+        set $x = ($x & 0x3333333333333333) + ($x >> 2 & 0x3333333333333333)
+        set $x = ($x & 0x0707070707070707) + ($x >> 4 & 0x0707070707070707)
+        set $x = ($x & 0x001f001f001f001f) + ($x >> 8 & 0x001f001f001f001f)
+        set $x = ($x & 0x0000003f0000003f) + ($x >>16 & 0x0000003f0000003f)
+        set $popcnt = ($x & 0x7f) + ($x >>32 & 0x7f)
+        set $index = $block->rank + $small_block_popcount + $popcnt
+      end
+    end
+    printf "%d", $table[$index-1].line_no
+  end
+  end
+end
+
+define check_method_entry
+  set $imemo = (struct RBasic *)$arg0
+  if $imemo != RUBY_Qfalse
+    set $type = ($imemo->flags >> 12) & 0x07
+    if $type == imemo_ment
+      set $me = (rb_callable_method_entry_t *)$imemo
+    else
+    if $type == imemo_svar
+      set $imemo = ((struct vm_svar *)$imemo)->cref_or_me
+      check_method_entry $imemo
+    end
+    end
+  end
+end
+
+define print_id
+  set $id = $arg0
+  # rb_id_to_serial
+  if $id > tLAST_OP_ID
+    set $serial = (rb_id_serial_t)($id >> RUBY_ID_SCOPE_SHIFT)
+  else
+    set $serial = (rb_id_serial_t)$id
+  end
+  if $serial && $serial <= ruby_global_symbols.last_id
+    set $idx = $serial / ID_ENTRY_UNIT
+    set $ids = (struct RArray *)ruby_global_symbols.ids
+    set $flags = $ids->basic.flags
+    if ($flags & RUBY_FL_USER1)
+      set $idsptr = $ids->as.ary
+      set $idslen = (($flags & (RUBY_FL_USER3|RUBY_FL_USER4)) >> (RUBY_FL_USHIFT+3))
+    else
+      set $idsptr = $ids->as.heap.ptr
+      set $idslen = $ids->as.heap.len
+    end
+    if $idx < $idslen
+      set $t = 0
+      set $ary = (struct RArray *)$idsptr[$idx]
+      if $ary != RUBY_Qnil
+        set $flags = $ary->basic.flags
+        if ($flags & RUBY_FL_USER1)
+          set $aryptr = $ary->as.ary
+          set $arylen = (($flags & (RUBY_FL_USER3|RUBY_FL_USER4)) >> (RUBY_FL_USHIFT+3))
+        else
+          set $aryptr = $ary->as.heap.ptr
+          set $arylen = $ary->as.heap.len
+        end
+        set $result = $aryptr[($serial % ID_ENTRY_UNIT) * ID_ENTRY_SIZE + $t]
+	if $result != RUBY_Qnil
+          print_string $result
+	else
+	  echo undef
+	end
+      end
+    end
+  end
+end
+
+define print_pathobj
+  set $flags = ((struct RBasic*)($arg0))->flags
+  if ($flags & RUBY_T_MASK) == RUBY_T_STRING
+    print_string $arg0
+  end
+  if ($flags & RUBY_T_MASK) == RUBY_T_ARRAY
+    if $flags & RUBY_FL_USER1
+      set $str = ((struct RArray*)($arg0))->as.ary[0]
+    else
+      set $str = ((struct RArray*)($arg0))->as.heap.ptr[0]
+    end
+    print_string $str
+  end
+end
+
+define rb_ps_thread
+  set $ps_thread = (struct RTypedData*)$arg0
+  set $ps_thread_th = (rb_thread_t*)$ps_thread->data
+  printf "* #<Thread:%p rb_thread_t:%p native_thread:%p>\n", \
+    $ps_thread, $ps_thread_th, $ps_thread_th->thread_id
+  set $cfp = $ps_thread_th->ec->cfp
+  set $cfpend = (rb_control_frame_t *)($ps_thread_th->ec->vm_stack + $ps_thread_th->ec->vm_stack_size)-1
+  while $cfp < $cfpend
+    if $cfp->iseq
+      if !((VALUE)$cfp->iseq & RUBY_IMMEDIATE_MASK) && (((imemo_ifunc << RUBY_FL_USHIFT) | RUBY_T_IMEMO)==$cfp->iseq->flags & ((RUBY_IMEMO_MASK << RUBY_FL_USHIFT) | RUBY_T_MASK))
+        printf "%d:ifunc ", $cfpend-$cfp
+        set print symbol-filename on
+        output/a $cfp->iseq.body
+        set print symbol-filename off
+        printf "\n"
+      else
+      if $cfp->pc
+        set $location = $cfp->iseq->body->location
+        printf "%d:", $cfpend-$cfp
+        print_pathobj $location.pathobj
+        printf ":"
+        print_lineno $cfp
+        printf ":in `"
+        print_string $location.label
+        printf "'\n"
+      else
+        printf "%d: ???.rb:???:in `???'\n", $cfpend-$cfp
+      end
+      end
+    else
+      # if VM_FRAME_TYPE($cfp->flag) == VM_FRAME_MAGIC_CFUNC
+      set $ep = $cfp->ep
+      if ($ep[0] & 0xffff0001) == 0x55550001
+        #define VM_ENV_FLAG_LOCAL 0x02
+        #define VM_ENV_PREV_EP(ep)   GC_GUARDED_PTR_REF(ep[VM_ENV_DATA_INDEX_SPECVAL])
+        set $me = 0
+        set $env_specval = $ep[-1]
+        set $env_me_cref = $ep[-2]
+        while ($env_specval & 0x02) != 0
+          check_method_entry $env_me_cref
+          if $me != 0
+            loop_break
+          end
+          set $ep = $ep[0]
+          set $env_specval = $ep[-1]
+          set $env_me_cref = $ep[-2]
+        end
+        if $me == 0
+          check_method_entry $env_me_cref
+        end
+        printf "%d:", $cfpend-$cfp
+        set print symbol-filename on
+        output/a $me->def->body.cfunc.func
+        set print symbol-filename off
+        set $mid = $me->def->original_id
+        printf ":in `"
+        print_id $mid
+        printf "'\n"
+      else
+        printf "%d:unknown_frame:???:in `???'\n", $cfpend-$cfp
+      end
+    end
+    set $cfp = $cfp + 1
+  end
+end
+
+define rb_count_objects
+  set $objspace = ruby_current_vm_ptr->objspace
+  set $counts_00 = 0
+  set $counts_01 = 0
+  set $counts_02 = 0
+  set $counts_03 = 0
+  set $counts_04 = 0
+  set $counts_05 = 0
+  set $counts_06 = 0
+  set $counts_07 = 0
+  set $counts_08 = 0
+  set $counts_09 = 0
+  set $counts_0a = 0
+  set $counts_0b = 0
+  set $counts_0c = 0
+  set $counts_0d = 0
+  set $counts_0e = 0
+  set $counts_0f = 0
+  set $counts_10 = 0
+  set $counts_11 = 0
+  set $counts_12 = 0
+  set $counts_13 = 0
+  set $counts_14 = 0
+  set $counts_15 = 0
+  set $counts_16 = 0
+  set $counts_17 = 0
+  set $counts_18 = 0
+  set $counts_19 = 0
+  set $counts_1a = 0
+  set $counts_1b = 0
+  set $counts_1c = 0
+  set $counts_1d = 0
+  set $counts_1e = 0
+  set $counts_1f = 0
+  set $total = 0
+  set $i = 0
+  while $i < $objspace->heap_pages.allocated_pages
+    printf "\rcounting... %d/%d", $i, $objspace->heap_pages.allocated_pages
+    set $page = $objspace->heap_pages.sorted[$i]
+    set $p = $page->start
+    set $pend = $p + $page->total_slots
+    while $p < $pend
+      set $flags = $p->as.basic.flags & 0x1f
+      eval "set $counts_%02x = $counts_%02x + 1", $flags, $flags
+      set $p = $p + 1
+    end
+    set $total = $total + $page->total_slots
+    set $i = $i + 1
+  end
+  printf "\rTOTAL: %d, FREE: %d\n", $total, $counts_00
+  printf "T_OBJECT: %d\n", $counts_01
+  printf "T_CLASS: %d\n", $counts_02
+  printf "T_MODULE: %d\n", $counts_03
+  printf "T_FLOAT: %d\n", $counts_04
+  printf "T_STRING: %d\n", $counts_05
+  printf "T_REGEXP: %d\n", $counts_06
+  printf "T_ARRAY: %d\n", $counts_07
+  printf "T_HASH: %d\n", $counts_08
+  printf "T_STRUCT: %d\n", $counts_09
+  printf "T_BIGNUM: %d\n", $counts_0a
+  printf "T_FILE: %d\n", $counts_0b
+  printf "T_DATA: %d\n", $counts_0c
+  printf "T_MATCH: %d\n", $counts_0d
+  printf "T_COMPLEX: %d\n", $counts_0e
+  printf "T_RATIONAL: %d\n", $counts_0f
+  #printf "UNKNOWN_10: %d\n", $counts_10
+  printf "T_NIL: %d\n", $counts_11
+  printf "T_TRUE: %d\n", $counts_12
+  printf "T_FALSE: %d\n", $counts_13
+  printf "T_SYMBOL: %d\n", $counts_14
+  printf "T_FIXNUM: %d\n", $counts_15
+  printf "T_UNDEF: %d\n", $counts_16
+  #printf "UNKNOWN_17: %d\n", $counts_17
+  #printf "UNKNOWN_18: %d\n", $counts_18
+  #printf "UNKNOWN_19: %d\n", $counts_19
+  printf "T_IMEMO: %d\n", $counts_1a
+  printf "T_NODE: %d\n", $counts_1b
+  printf "T_ICLASS: %d\n", $counts_1c
+  printf "T_ZOMBIE: %d\n", $counts_1d
+  #printf "UNKNOWN_1E: %d\n", $counts_1e
+  printf "T_MASK: %d\n", $counts_1f
+end
+document rb_count_objects
+  Counts all objects grouped by type.
+end
+
+# Details: https://bugs.ruby-lang.org/projects/ruby-master/wiki/MachineInstructionsTraceWithGDB
+define trace_machine_instructions
+  set logging on
+  set height 0
+  set width 0
+  display/i $pc
+  while !$exit_code
+    info line *$pc
+    si
+  end
+end
+
+define SDR
+  call rb_vmdebug_stack_dump_raw_current()
+end
+
+define rbi
+  if ((LINK_ELEMENT*)$arg0)->type == ISEQ_ELEMENT_LABEL
+    p *(LABEL*)$arg0
+  else
+  if ((LINK_ELEMENT*)$arg0)->type == ISEQ_ELEMENT_INSN
+    p *(INSN*)$arg0
+  else
+  if ((LINK_ELEMENT*)$arg0)->type == ISEQ_ELEMENT_ADJUST
+    p *(ADJUST*)$arg0
+  else
+    print *$arg0
+  end
+  end
+  end
+end
+
+define dump_node
+  set $str = rb_parser_dump_tree($arg0, 0)
+  set $flags = ((struct RBasic*)($str))->flags
+  printf "%s", (char *)(($flags & RUBY_FL_USER1) ? \
+                        ((struct RString*)$str)->as.heap.ptr : \
+                        ((struct RString*)$str)->as.ary)
+end
+
+define print_flags
+  printf "RUBY_FL_WB_PROTECTED: %s\n", ((struct RBasic*)($arg0))->flags & RUBY_FL_WB_PROTECTED ? "1" : "0"
+  printf "RUBY_FL_PROMOTED0   : %s\n", ((struct RBasic*)($arg0))->flags & RUBY_FL_PROMOTED0 ? "1" : "0"
+  printf "RUBY_FL_PROMOTED1   : %s\n", ((struct RBasic*)($arg0))->flags & RUBY_FL_PROMOTED1 ? "1" : "0"
+  printf "RUBY_FL_FINALIZE    : %s\n", ((struct RBasic*)($arg0))->flags & RUBY_FL_FINALIZE ? "1" : "0"
+  printf "RUBY_FL_TAINT       : %s\n", ((struct RBasic*)($arg0))->flags & RUBY_FL_TAINT ? "1" : "0"
+  printf "RUBY_FL_UNTRUSTED   : %s\n", ((struct RBasic*)($arg0))->flags & RUBY_FL_UNTRUSTED ? "1" : "0"
+  printf "RUBY_FL_EXIVAR      : %s\n", ((struct RBasic*)($arg0))->flags & RUBY_FL_EXIVAR ? "1" : "0"
+  printf "RUBY_FL_FREEZE      : %s\n", ((struct RBasic*)($arg0))->flags & RUBY_FL_FREEZE ? "1" : "0"
+
+  printf "RUBY_FL_USER0       : %s\n", ((struct RBasic*)($arg0))->flags & RUBY_FL_USER0 ? "1" : "0"
+  printf "RUBY_FL_USER1       : %s\n", ((struct RBasic*)($arg0))->flags & RUBY_FL_USER1 ? "1" : "0"
+  printf "RUBY_FL_USER2       : %s\n", ((struct RBasic*)($arg0))->flags & RUBY_FL_USER2 ? "1" : "0"
+  printf "RUBY_FL_USER3       : %s\n", ((struct RBasic*)($arg0))->flags & RUBY_FL_USER3 ? "1" : "0"
+  printf "RUBY_FL_USER4       : %s\n", ((struct RBasic*)($arg0))->flags & RUBY_FL_USER4 ? "1" : "0"
+  printf "RUBY_FL_USER5       : %s\n", ((struct RBasic*)($arg0))->flags & RUBY_FL_USER5 ? "1" : "0"
+  printf "RUBY_FL_USER6       : %s\n", ((struct RBasic*)($arg0))->flags & RUBY_FL_USER6 ? "1" : "0"
+  printf "RUBY_FL_USER7       : %s\n", ((struct RBasic*)($arg0))->flags & RUBY_FL_USER7 ? "1" : "0"
+  printf "RUBY_FL_USER8       : %s\n", ((struct RBasic*)($arg0))->flags & RUBY_FL_USER8 ? "1" : "0"
+  printf "RUBY_FL_USER9       : %s\n", ((struct RBasic*)($arg0))->flags & RUBY_FL_USER9 ? "1" : "0"
+  printf "RUBY_FL_USER10      : %s\n", ((struct RBasic*)($arg0))->flags & RUBY_FL_USER10 ? "1" : "0"
+  printf "RUBY_FL_USER11      : %s\n", ((struct RBasic*)($arg0))->flags & RUBY_FL_USER11 ? "1" : "0"
+  printf "RUBY_FL_USER12      : %s\n", ((struct RBasic*)($arg0))->flags & RUBY_FL_USER12 ? "1" : "0"
+  printf "RUBY_FL_USER13      : %s\n", ((struct RBasic*)($arg0))->flags & RUBY_FL_USER13 ? "1" : "0"
+  printf "RUBY_FL_USER14      : %s\n", ((struct RBasic*)($arg0))->flags & RUBY_FL_USER14 ? "1" : "0"
+  printf "RUBY_FL_USER15      : %s\n", ((struct RBasic*)($arg0))->flags & RUBY_FL_USER15 ? "1" : "0"
+  printf "RUBY_FL_USER16      : %s\n", ((struct RBasic*)($arg0))->flags & RUBY_FL_USER16 ? "1" : "0"
+  printf "RUBY_FL_USER17      : %s\n", ((struct RBasic*)($arg0))->flags & RUBY_FL_USER17 ? "1" : "0"
+  printf "RUBY_FL_USER18      : %s\n", ((struct RBasic*)($arg0))->flags & RUBY_FL_USER18 ? "1" : "0"
+end
diff --git a/.gitattributes b/.gitattributes
new file mode 100644
index 0000000000..d0c2d266b4
--- /dev/null
+++ b/.gitattributes
@@ -0,0 +1,8 @@
+*.gemspec diff=ruby
+*.rb diff=ruby
+bin svn-properties=svn:ignore=ruby
+bin/* diff=ruby
+tool/update-deps diff=ruby
+tool/make-snapshot diff=ruby
+tool/format-release diff=ruby
+tool/leaked-globals diff=ruby
diff --git a/.github/SECURITY.md b/.github/SECURITY.md
new file mode 100644
index 0000000000..56baa29942
--- /dev/null
+++ b/.github/SECURITY.md
@@ -0,0 +1,9 @@
+# Security Policy
+
+## Supported Versions
+
+See <https://www.ruby-lang.org/en/downloads/branches/>.
+
+## Reporting a Vulnerability
+
+See <https://www.ruby-lang.org/en/security/>.
diff --git a/.github/codeql/codeql-config.yml b/.github/codeql/codeql-config.yml
new file mode 100644
index 0000000000..7196708b21
--- /dev/null
+++ b/.github/codeql/codeql-config.yml
@@ -0,0 +1,4 @@
+name: "CodeQL config for the Ruby language"
+
+paths-ignore:
+  - '/ext/**/*/conftest.c'
diff --git a/.github/workflows/baseruby.yml b/.github/workflows/baseruby.yml
new file mode 100644
index 0000000000..16d1e4a85a
--- /dev/null
+++ b/.github/workflows/baseruby.yml
@@ -0,0 +1,47 @@
+name: BASERUBY Check
+
+on: [push, pull_request]
+
+jobs:
+  baseruby:
+    name: BASERUBY
+    runs-on: ubuntu-20.04
+    if: "!contains(github.event.head_commit.message, '[ci skip]')"
+    strategy:
+      matrix:
+        ruby:
+          - ruby-2.2
+#         - ruby-2.3
+#         - ruby-2.4
+#         - ruby-2.5
+#         - ruby-2.6
+          - ruby-2.7
+
+    steps:
+      - uses: actions/checkout@v2
+      - uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: ${{ matrix.ruby }}
+          bundler: none
+      - run: echo "make=make -sj$((1 + $(nproc --all)))" >> $GITHUB_ENV
+      - run: sudo apt-get install build-essential autoconf bison
+      - run: ./autogen.sh
+      - run: ./configure --disable-install-doc
+      - run: $make update-unicode
+      - run: $make common-srcs
+      - run: $make incs
+      - run: $make all
+      - run: $make test
+      - uses: k0kubun/action-slack@v2.0.0
+        with:
+          payload: |
+            {
+              "ci": "GitHub Actions",
+              "env": "${{ github.workflow }} / BASERUBY @ ${{ matrix.ruby }}",
+              "url": "https://github.com/${{ github.repository }}/actions/runs/${{ github.run_id }}",
+              "commit": "${{ github.sha }}",
+              "branch": "${{ github.ref }}".split('/').reverse()[0]
+            }
+        env:
+          SLACK_WEBHOOK_URL: ${{ secrets.SIMPLER_ALERTS_URL }} # ruby-lang slack: ruby/simpler-alerts-bot
+        if: failure() && github.event_name == 'push'
diff --git a/.github/workflows/check_dependencies.yml b/.github/workflows/check_dependencies.yml
new file mode 100644
index 0000000000..26d2ca473d
--- /dev/null
+++ b/.github/workflows/check_dependencies.yml
@@ -0,0 +1,45 @@
+name: Check Dependencies
+on: [push, pull_request]
+jobs:
+  update-deps:
+    strategy:
+      matrix:
+        os: [ubuntu-20.04, macos-latest]
+      fail-fast: true
+    runs-on: ${{ matrix.os }}
+    if: "!contains(github.event.head_commit.message, '[ci skip]')"
+    steps:
+      - name: Install libraries
+        run: |
+          set -x
+          sudo apt-get update -q || :
+          sudo apt-get install --no-install-recommends -q -y build-essential libssl-dev libyaml-dev libreadline6-dev zlib1g-dev libncurses5-dev libffi-dev libgdbm-dev bison autoconf ruby
+        if: "contains(matrix.os, 'ubuntu')"
+      - name: Install libraries
+        run: |
+          brew update
+          brew install gdbm gmp libffi openssl@1.1 zlib autoconf automake libtool readline
+        if: "contains(matrix.os, 'macos')"
+      - name: git config
+        run: |
+          git config --global advice.detachedHead 0
+      - uses: actions/checkout@v2
+      - run: ./autogen.sh
+      - name: Run configure
+        run: ./configure -C --disable-install-doc --disable-rubygems --with-gcc 'optflags=-O0' 'debugflags=-save-temps=obj -g'
+      - run: make all golf
+      - run: ruby tool/update-deps --fix
+      - run: git diff --no-ext-diff --ignore-submodules --exit-code
+      - uses: k0kubun/action-slack@v2.0.0
+        with:
+          payload: |
+            {
+              "ci": "GitHub Actions",
+              "env": "${{ matrix.os }} / Dependencies need to update",
+              "url": "https://github.com/${{ github.repository }}/actions/runs/${{ github.run_id }}",
+              "commit": "${{ github.sha }}",
+              "branch": "${{ github.ref }}".split('/').reverse()[0]
+            }
+        env:
+          SLACK_WEBHOOK_URL: ${{ secrets.SIMPLER_ALERTS_URL }} # ruby-lang slack: ruby/simpler-alerts-bot
+        if: failure() && github.event_name == 'push'
diff --git a/.github/workflows/check_misc.yml b/.github/workflows/check_misc.yml
new file mode 100644
index 0000000000..576341bf88
--- /dev/null
+++ b/.github/workflows/check_misc.yml
@@ -0,0 +1,17 @@
+name: Miscellaneous checks
+on: [push, pull_request]
+
+jobs:
+  checks:
+    runs-on: ubuntu-20.04
+    steps:
+      - uses: actions/checkout@v2
+      - name: Check if C-sources are US-ASCII
+        run: |
+          ! grep -r -n '[^	 -~]' *.[chy] include internal win32/*.[ch]
+      - name: Check for header macros
+        run: |
+          ! for header in ruby/*.h; do \
+            git grep -l -F -e $header -e HAVE_`echo $header | tr a-z./ A-Z__` -- . > /dev/null || echo $header
+          done | grep -F .
+        working-directory: include
diff --git a/.github/workflows/codeql-analysis.yml b/.github/workflows/codeql-analysis.yml
new file mode 100644
index 0000000000..2dc47c0683
--- /dev/null
+++ b/.github/workflows/codeql-analysis.yml
@@ -0,0 +1,43 @@
+name: "Code scanning - action"
+
+on:
+  push:
+  pull_request:
+  schedule:
+    - cron: '0 12 * * 4'
+
+jobs:
+  CodeQL-Build:
+
+    # CodeQL runs on ubuntu-20.04 and windows-latest
+    runs-on: ubuntu-20.04
+
+    steps:
+    - name: Install libraries
+      run: |
+        set -x
+        sudo apt-get update -q || :
+        sudo apt-get install --no-install-recommends -q -y build-essential libssl-dev libyaml-dev libreadline6-dev zlib1g-dev libncurses5-dev libffi-dev libgdbm-dev bison autoconf ruby
+
+    - name: Checkout repository
+      uses: actions/checkout@v2
+      with:
+        fetch-depth: 2
+
+    - run: git checkout HEAD^2
+      if: ${{ github.event_name == 'pull_request' }}
+
+    - name: Remove an obsolete rubygems vendored file
+      run: sudo rm /usr/lib/ruby/vendor_ruby/rubygems/defaults/operating_system.rb
+
+    - name: Initialize CodeQL
+      uses: github/codeql-action/init@v2
+      with:
+        languages: cpp
+        config-file: ./.github/codeql/codeql-config.yml
+
+    - name: Autobuild
+      uses: github/codeql-action/autobuild@v2
+
+    - name: Perform CodeQL Analysis
+      uses: github/codeql-action/analyze@v2
diff --git a/.github/workflows/compilers.yml b/.github/workflows/compilers.yml
new file mode 100644
index 0000000000..47b73fb907
--- /dev/null
+++ b/.github/workflows/compilers.yml
@@ -0,0 +1,245 @@
+name: Compilations
+
+on:
+  push:
+    paths-ignore:
+      - 'doc/**'
+      - '**.md'
+      - '**.rdoc'
+  pull_request:
+    paths-ignore:
+      - 'doc/**'
+      - '**.md'
+      - '**.rdoc'
+
+concurrency:
+  group: ${{ github.workflow }} / ${{ startsWith(github.event_name, 'pull') && github.ref_name || github.sha }}
+  cancel-in-progress: ${{ startsWith(github.event_name, 'pull') }}
+
+# Github actions does not support YAML anchors.  This creative use of
+# environment variables (plus the "echo $GITHUB_ENV" hack) is to reroute that
+# restriction.
+env:
+  default_cc: clang-14
+  append_cc: ''
+  crosshost: ''
+
+  # -O1 is faster than -O3 in our tests... Majority of time are consumed trying
+  # to optimize binaries.  Also Github Actions run on relatively modern CPUs
+  # compared to, say, GCC 4 or Clang 3.  We don't specify `-march=native`
+  # because compilers tend not understand what the CPU is.
+  optflags: '-O1'
+
+  # -g0 disables backtraces when SEGV.  Do not set that.
+  debugflags: '-ggdb3'
+
+  default_configure: >-
+    --enable-debug-env
+    --disable-install-doc
+    --with-ext=-test-/cxxanyargs,+
+  append_configure: >-
+    --without-valgrind
+    --without-jemalloc
+    --without-gmp
+
+  UPDATE_UNICODE: >-
+    UNICODE_FILES=.
+    UNICODE_PROPERTY_FILES=.
+    UNICODE_AUXILIARY_FILES=.
+    UNICODE_EMOJI_FILES=.
+  CONFIGURE_TTY: never
+  GITPULLOPTIONS: --no-tags origin ${{github.ref}}
+  RUBY_DEBUG: ci rgengc
+  RUBY_TESTOPTS: >-
+    -q
+    --color=always
+    --tty=no
+
+jobs:
+  compile:
+    strategy:
+      fail-fast: false
+      matrix:
+        entry:
+          - { key: default_cc, name: gcc-11,    value: gcc-11,    container: gcc-11 }
+          - { key: default_cc, name: gcc-10,    value: gcc-10,    container: gcc-10 }
+          - { key: default_cc, name: gcc-9,     value: gcc-9,     container: gcc-9 }
+          - { key: default_cc, name: gcc-8,     value: gcc-8,     container: gcc-8 }
+          - { key: default_cc, name: gcc-7,     value: gcc-7,     container: gcc-7 }
+          - { key: default_cc, name: gcc-6,     value: gcc-6,     container: gcc-6 }
+          - { key: default_cc, name: gcc-5,     value: gcc-5,     container: gcc-5 }
+          - { key: default_cc, name: gcc-4.8,   value: gcc-4.8,   container: gcc-4.8 }
+          - key: default_cc
+            name: 'gcc-11 LTO'
+            value: 'gcc-11 -O2 -flto=auto -ffat-lto-objects'
+            container: gcc-11
+            shared: '--disable-shared'
+            # check: true
+          - { key: default_cc, name: clang-14,  value: clang-14,  container: clang-14 }
+          - { key: default_cc, name: clang-13,  value: clang-13,  container: clang-13 }
+          - { key: default_cc, name: clang-12,  value: clang-12,  container: clang-12 }
+          - { key: default_cc, name: clang-11,  value: clang-11,  container: clang-11 }
+          - { key: default_cc, name: clang-10,  value: clang-10,  container: clang-10 }
+          - { key: default_cc, name: clang-9,   value: clang-9,   container: clang-9 }
+          - { key: default_cc, name: clang-8,   value: clang-8,   container: clang-8 }
+          - { key: default_cc, name: clang-7,   value: clang-7,   container: clang-7 }
+          - { key: default_cc, name: clang-6.0, value: clang-6.0, container: clang-6.0 }
+          - { key: default_cc, name: clang-5.0, value: clang-5.0, container: clang-5.0 }
+          - { key: default_cc, name: clang-4.0, value: clang-4.0, container: clang-4.0 }
+          - { key: default_cc, name: clang-3.9, value: clang-3.9, container: clang-3.9 }
+          - key: default_cc
+            name: 'clang-14 LTO'
+            value: 'clang-14 -O2 -flto=auto'
+            container: clang-14
+            shared: '--disable-shared'
+            # check: true
+
+          - { key: crosshost, name: aarch64-linux-gnu,     value: aarch64-linux-gnu, container: crossbuild-essential-arm64 }
+#         - { key: crosshost, name: arm-linux-gnueabi,     value: arm-linux-gnueabi }
+#         - { key: crosshost, name: arm-linux-gnueabihf,   value: arm-linux-gnueabihf }
+#         - { key: crosshost, name: i686-w64-mingw32,      value: i686-w64-mingw32 }
+#         - { key: crosshost, name: powerpc-linux-gnu,     value: powerpc-linux-gnu }
+          - { key: crosshost, name: powerpc64le-linux-gnu, value: powerpc64le-linux-gnu, container: crossbuild-essential-ppc64el }
+          - { key: crosshost, name: s390x-linux-gnu,       value: s390x-linux-gnu, container: crossbuild-essential-s390x }
+          - { key: crosshost, name: x86_64-w64-mingw32,    value: x86_64-w64-mingw32, container: mingw-w64 }
+
+          - { key: append_cc, name: c99,   value: '-std=c99   -Werror=pedantic -pedantic-errors' }
+#         - { key: append_cc, name: c11,   value: '-std=c11   -Werror=pedantic -pedantic-errors' }
+#         - { key: append_cc, name: c17,   value: '-std=c17   -Werror=pedantic -pedantic-errors' }
+#         - { key: append_cc, name: c2x,   value: '-std=c2x   -Werror=pedantic -pedantic-errors' }
+          - { key: CXXFLAGS,  name: c++98, value: '-std=c++98 -Werror=pedantic -pedantic-errors -Wno-c++11-long-long' }
+#         - { key: CXXFLAGS,  name: c++11, value: '-std=c++11 -Werror=pedantic -pedantic-errors -Wno-c++11-long-long' }
+#         - { key: CXXFLAGS,  name: c++14, value: '-std=c++14 -Werror=pedantic -pedantic-errors -Wno-c++11-long-long' }
+#         - { key: CXXFLAGS,  name: c++17, value: '-std=c++17 -Werror=pedantic -pedantic-errors -Wno-c++11-long-long' }
+          - { key: CXXFLAGS,  name: c++2a, value: '-std=c++2a -Werror=pedantic -pedantic-errors -Wno-c++11-long-long' }
+
+          - { key: optflags, name: '-O0', value: '-O0 -march=x86-64 -mtune=generic' }
+#         - { key: optflags, name: '-O3', value: '-O3 -march=x86-64 -mtune=generic', check: true }
+
+          - { key: append_configure, name: gmp,                  value: '--with-gmp' }
+          - { key: append_configure, name: jemalloc,             value: '--with-jemalloc' }
+          - { key: append_configure, name: valgrind,             value: '--with-valgrind' }
+          - { key: append_configure, name: 'coroutine=ucontext', value: '--with-coroutine=ucontext' }
+          - { key: append_configure, name: 'coroutine=copy',     value: '--with-coroutine=copy' }
+          - { key: append_configure, name: disable-jit-support,  value: '--disable-jit-support' }
+          - { key: append_configure, name: disable-dln,          value: '--disable-dln' }
+          - { key: append_configure, name: disable-rubygems,     value: '--disable-rubygems' }
+
+          - { key: cppflags, name: OPT_THREADED_CODE=1,            value: '-DOPT_THREADED_CODE=1' }
+          - { key: cppflags, name: OPT_THREADED_CODE=2,            value: '-DOPT_THREADED_CODE=2' }
+          - { key: cppflags, name: OPT_THREADED_CODE=3,            value: '-DOPT_THREADED_CODE=3' }
+
+          - { key: cppflags, name: NDEBUG,                         value: '-DNDEBUG' }
+          - { key: cppflags, name: RUBY_DEBUG,                     value: '-DRUBY_DEBUG' }
+#         - { key: cppflags, name: ARRAY_DEBUG,                    value: '-DARRAY_DEBUG' }
+#         - { key: cppflags, name: BIGNUM_DEBUG,                   value: '-DBIGNUM_DEBUG' }
+#         - { key: cppflags, name: CCAN_LIST_DEBUG,                value: '-DCCAN_LIST_DEBUG' }
+#         - { key: cppflags, name: CPDEBUG=-1,                     value: '-DCPDEBUG=-1' }
+#         - { key: cppflags, name: ENC_DEBUG,                      value: '-DENC_DEBUG' }
+#         - { key: cppflags, name: GC_DEBUG,                       value: '-DGC_DEBUG' }
+#         - { key: cppflags, name: HASH_DEBUG,                     value: '-DHASH_DEBUG' }
+#         - { key: cppflags, name: ID_TABLE_DEBUG,                 value: '-DID_TABLE_DEBUG' }
+#         - { key: cppflags, name: RGENGC_DEBUG=-1,                value: '-DRGENGC_DEBUG=-1' }
+#         - { key: cppflags, name: SYMBOL_DEBUG,                   value: '-DSYMBOL_DEBUG' }
+#         - { key: cppflags, name: THREAD_DEBUG=-1,                value: '-DTHREAD_DEBUG=-1' }
+
+#         - { key: cppflags, name: RGENGC_CHECK_MODE,              value: '-DRGENGC_CHECK_MODE' }
+#         - { key: cppflags, name: TRANSIENT_HEAP_CHECK_MODE,      value: '-DTRANSIENT_HEAP_CHECK_MODE' }
+#         - { key: cppflags, name: VM_CHECK_MODE,                  value: '-DVM_CHECK_MODE' }
+
+          - { key: cppflags, name: USE_EMBED_CI=0,                 value: '-DUSE_EMBED_CI=0' }
+          - { key: cppflags, name: USE_FLONUM=0,                   value: '-DUSE_FLONUM=0' }
+#         - { key: cppflags, name: USE_GC_MALLOC_OBJ_INFO_DETAILS, value: '-DUSE_GC_MALLOC_OBJ_INFO_DETAILS' }
+          - { key: cppflags, name: USE_LAZY_LOAD,                  value: '-DUSE_LAZY_LOAD' }
+#         - { key: cppflags, name: USE_RINCGC=0,                   value: '-DUSE_RINCGC=0' }
+#         - { key: cppflags, name: USE_SYMBOL_GC=0,                value: '-DUSE_SYMBOL_GC=0' }
+#         - { key: cppflags, name: USE_THREAD_CACHE=0,             value: '-DUSE_THREAD_CACHE=0' }
+#         - { key: cppflags, name: USE_TRANSIENT_HEAP=0,           value: '-DUSE_TRANSIENT_HEAP=0' }
+#         - { key: cppflags, name: USE_RUBY_DEBUG_LOG=1,           value: '-DUSE_RUBY_DEBUG_LOG=1' }
+
+          - { key: cppflags, name: DEBUG_FIND_TIME_NUMGUESS,       value: '-DDEBUG_FIND_TIME_NUMGUESS' }
+          - { key: cppflags, name: DEBUG_INTEGER_PACK,             value: '-DDEBUG_INTEGER_PACK' }
+#         - { key: cppflags, name: ENABLE_PATH_CHECK,              value: '-DENABLE_PATH_CHECK' }
+
+          - { key: cppflags, name: GC_DEBUG_STRESS_TO_CLASS,       value: '-DGC_DEBUG_STRESS_TO_CLASS' }
+#         - { key: cppflags, name: GC_ENABLE_LAZY_SWEEP=0,         value: '-DGC_ENABLE_LAZY_SWEEP=0' }
+#         - { key: cppflags, name: GC_PROFILE_DETAIL_MEMOTY,       value: '-DGC_PROFILE_DETAIL_MEMOTY' }
+#         - { key: cppflags, name: GC_PROFILE_MORE_DETAIL,         value: '-DGC_PROFILE_MORE_DETAIL' }
+
+#         - { key: cppflags, name: CALC_EXACT_MALLOC_SIZE,         value: '-DCALC_EXACT_MALLOC_SIZE' }
+#         - { key: cppflags, name: MALLOC_ALLOCATED_SIZE_CHECK,    value: '-DMALLOC_ALLOCATED_SIZE_CHECK' }
+
+#         - { key: cppflags, name: IBF_ISEQ_ENABLE_LOCAL_BUFFER,   value: '-DIBF_ISEQ_ENABLE_LOCAL_BUFFER' }
+
+#         - { key: cppflags, name: RGENGC_ESTIMATE_OLDMALLOC,      value: '-DRGENGC_ESTIMATE_OLDMALLOC' }
+#         - { key: cppflags, name: RGENGC_FORCE_MAJOR_GC,          value: '-DRGENGC_FORCE_MAJOR_GC' }
+#         - { key: cppflags, name: RGENGC_OBJ_INFO,                value: '-DRGENGC_OBJ_INFO' }
+#         - { key: cppflags, name: RGENGC_OLD_NEWOBJ_CHECK,        value: '-DRGENGC_OLD_NEWOBJ_CHECK' }
+#         - { key: cppflags, name: RGENGC_PROFILE,                 value: '-DRGENGC_PROFILE' }
+
+#         - { key: cppflags, name: VM_DEBUG_BP_CHECK,              value: '-DVM_DEBUG_BP_CHECK' }
+#         - { key: cppflags, name: VM_DEBUG_VERIFY_METHOD_CACHE,   value: '-DVM_DEBUG_VERIFY_METHOD_CACHE' }
+
+          - { key: cppflags, name: MJIT_FORCE_ENABLE,              value: '-DMJIT_FORCE_ENABLE' }
+          - { key: cppflags, name: YJIT_FORCE_ENABLE,              value: '-DYJIT_FORCE_ENABLE' }
+
+    name: ${{ matrix.entry.name }}
+    runs-on: ubuntu-latest
+    container:
+      image: ghcr.io/ruby/ruby-ci-image:${{ matrix.entry.container || 'clang-14' }}
+      options: --user root
+    if: ${{ !startsWith(github.event.head_commit.message, '[DOC]') && !contains(github.event.pull_request.labels.*.name, 'Documentation') }}
+    steps:
+      - run: id
+        working-directory:
+      - run: mkdir build
+        working-directory:
+      - name: setenv
+        run: |
+          echo "${{ matrix.entry.key }}=${{ matrix.entry.value }}" >> $GITHUB_ENV
+          echo "GNUMAKEFLAGS=-sj$((1 + $(nproc --all)))" >> $GITHUB_ENV
+      - uses: actions/checkout@v3
+        with:
+          path: src
+      - uses: actions/cache@v3
+        with:
+          path: src/.downloaded-cache
+          key: downloaded-cache
+      - run: ./autogen.sh
+        working-directory: src
+      - name: Run configure
+        run: >
+          ../src/configure -C ${default_configure} ${append_configure}
+          ${{ matrix.entry.key == 'crosshost' && '--host="${crosshost}"' || '--with-gcc="${default_cc} ${append_cc}"' }}
+          ${{ matrix.entry.shared || '--enable-shared' }}
+      - run: make extract-extlibs
+      - run: make incs
+      - run: make
+#     - run: make leaked-globals
+      - run: make test
+      - run: make install
+        if: ${{ matrix.entry.check }}
+      - run: make test-tool
+        if: ${{ matrix.entry.check }}
+      - run: make test-all TESTS='-- ruby -ext-'
+        if: ${{ matrix.entry.check }}
+      - run: make test-spec
+        if: ${{ matrix.entry.check }}
+
+      - uses: k0kubun/action-slack@v2.0.0
+        with:
+          payload: |
+            {
+              "ci": "GitHub Actions",
+              "env": "${{ github.workflow }} / ${{ matrix.entry.name }}",
+              "url": "https://github.com/${{ github.repository }}/actions/runs/${{ github.run_id }}",
+              "commit": "${{ github.sha }}",
+              "branch": "${{ github.ref }}".split('/').reverse()[0]
+            }
+        env:
+          SLACK_WEBHOOK_URL: ${{ secrets.SIMPLER_ALERTS_URL }} # ruby-lang slack: ruby/simpler-alerts-bot
+        if: ${{ failure() && github.event_name == 'push' }}
+
+defaults:
+  run:
+    working-directory: build
diff --git a/.github/workflows/macos.yml b/.github/workflows/macos.yml
new file mode 100644
index 0000000000..1da94630fe
--- /dev/null
+++ b/.github/workflows/macos.yml
@@ -0,0 +1,66 @@
+name: macOS
+on: [push, pull_request]
+jobs:
+  make:
+    runs-on: macos-latest
+    strategy:
+      matrix:
+        test_task: [ "check" ] #, "test-bundler-parallel", "test-bundled-gems" ] matrix tests has unknown issues
+      fail-fast: false
+    env:
+      GITPULLOPTIONS: --no-tags origin ${{github.ref}}
+    if: "!contains(github.event.head_commit.message, '[ci skip]')"
+    steps:
+      - run: mkdir build
+        working-directory:
+      - name: Disable Firewall
+        run: |
+          sudo /usr/libexec/ApplicationFirewall/socketfilterfw --setglobalstate off
+          sudo /usr/libexec/ApplicationFirewall/socketfilterfw --getglobalstate
+      - name: git config
+        run: |
+          git config --global advice.detachedHead 0
+      - uses: actions/checkout@v2
+        with:
+          path: src
+      - name: Install libraries
+        run: |
+          export WAITS='5 60'
+          tool/travis_retry.sh brew update
+          tool/travis_retry.sh brew install gdbm gmp libffi openssl@1.1 zlib autoconf automake libtool readline
+        working-directory: src
+      - name: Set ENV
+        run: |
+          echo "JOBS=-j$((1 + $(sysctl -n hw.activecpu)))" >> $GITHUB_ENV
+      - run: ./autogen.sh
+        working-directory: src
+      - name: Run configure
+        run: ../src/configure -C --disable-install-doc --with-openssl-dir=$(brew --prefix openssl@1.1) --with-readline-dir=$(brew --prefix readline)
+      - run: make $JOBS incs
+      - run: make $JOBS
+      - run: make leaked-globals
+        if: matrix.test_task == 'check'
+      - run: make prepare-gems
+        if: matrix.test_task == 'check'
+      - run: make $JOBS -s ${{ matrix.test_task }}
+        timeout-minutes: 60
+        env:
+          RUBY_TESTOPTS: "-q --tty=no"
+          TEST_BUNDLED_GEMS_ALLOW_FAILURES: "rexml"
+      - uses: k0kubun/action-slack@v2.0.0
+        with:
+          payload: |
+            {
+              "ci": "GitHub Actions",
+              "env": "${{ github.workflow }} / ${{ matrix.test_task }}",
+              "url": "https://github.com/${{ github.repository }}/actions/runs/${{ github.run_id }}",
+              "commit": "${{ github.sha }}",
+              "branch": "${{ github.ref }}".split('/').reverse()[0]
+            }
+        env:
+          SLACK_WEBHOOK_URL: ${{ secrets.SIMPLER_ALERTS_URL }} # ruby-lang slack: ruby/simpler-alerts-bot
+        if: failure() && github.event_name == 'push'
+
+defaults:
+  run:
+    working-directory: build
diff --git a/.github/workflows/mingw.yml b/.github/workflows/mingw.yml
new file mode 100644
index 0000000000..a5d64c7b2d
--- /dev/null
+++ b/.github/workflows/mingw.yml
@@ -0,0 +1,141 @@
+name: MinGW
+on: [push, pull_request]
+
+# Notes:
+# Actions console encoding causes issues, see test-all & test-spec steps
+#
+jobs:
+  make:
+    runs-on: windows-2022
+    name: ${{ github.workflow }} (${{ matrix.msystem }})
+    env:
+      MSYSTEM: MINGW64
+      MSYSTEM_PREFIX: /mingw64
+      MSYS2_ARCH: x86_64
+      CHOST: "x86_64-w64-mingw32"
+      CFLAGS:   "-march=x86-64 -mtune=generic -O3 -pipe -fstack-protector-strong"
+      CXXFLAGS: "-march=x86-64 -mtune=generic -O3 -pipe"
+      CPPFLAGS: "-D_FORTIFY_SOURCE=2 -D__USE_MINGW_ANSI_STDIO=1 -DFD_SETSIZE=2048"
+      LDFLAGS:  "-pipe -fstack-protector-strong"
+      UPDATE_UNICODE: "UNICODE_FILES=. UNICODE_PROPERTY_FILES=. UNICODE_AUXILIARY_FILES=. UNICODE_EMOJI_FILES=."
+      GITPULLOPTIONS: --no-tags origin ${{github.ref}}
+    strategy:
+      matrix:
+        test_task: [ "check" ] # to make job names consistent
+      fail-fast: false
+    if: "!contains(github.event.head_commit.message, '[ci skip]')"
+    steps:
+      - run: mkdir build
+        working-directory:
+      - name: git config
+        run: |
+          git config --system core.autocrlf false
+          git config --system core.eol lf
+          git config --system advice.detachedHead 0
+      - uses: actions/checkout@v2
+        with:
+          path: src
+      - name: Set up Ruby & MSYS2
+        uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: 2.6
+          mingw: _upgrade_ gdbm gmp libffi libyaml openssl ragel readline
+          msys2: automake1.16 bison
+      - name: where check
+        run: |
+          # show where
+          Write-Host
+          $where = 'gcc.exe', 'ragel.exe', 'make.exe', 'bison.exe', 'libcrypto-1_1-x64.dll', 'libssl-1_1-x64.dll'
+          foreach ($e in $where) {
+            $rslt = where.exe $e 2>&1 | Out-String
+            if ($rslt.contains($e)) { Write-Host $rslt }
+            else { Write-Host "`nCan't find $e" }
+          }
+
+      - name: autogen
+        run: |
+          ./autogen.sh
+        working-directory: src
+        shell: sh
+
+      - name: configure
+        run: |
+          # Actions uses UTF8, causes test failures, similar to normal OS setup
+          $PSDefaultParameterValues['*:Encoding'] = 'utf8'
+          [Console]::OutputEncoding = [System.Text.Encoding]::GetEncoding("IBM437")
+          [Console]::InputEncoding  = [System.Text.Encoding]::GetEncoding("IBM437")
+          $config_args = "--build=$env:CHOST --host=$env:CHOST --target=$env:CHOST"
+          Write-Host $config_args
+          sh -c "../src/configure --disable-install-doc --prefix=/. $config_args"
+          # Write-Host "-------------------------------------- config.log"
+          # Get-Content ./config.log | foreach {Write-Output $_}
+
+      - name: update
+        run: |
+          $jobs = [int](2 * $env:NUMBER_OF_PROCESSORS)
+          make -j $jobs incs
+
+      - name: download gems
+        run: |
+          $jobs = [int](2 * $env:NUMBER_OF_PROCESSORS)
+          make -j $jobs update-gems
+
+      - name: make all
+        timeout-minutes: 40
+        run: |
+          $jobs = [int](2 * $env:NUMBER_OF_PROCESSORS)
+          make -j $jobs
+
+      - name: make install
+        run: |
+          # Actions uses UTF8, causes test failures, similar to normal OS setup
+          $PSDefaultParameterValues['*:Encoding'] = 'utf8'
+          [Console]::OutputEncoding = [System.Text.Encoding]::GetEncoding("IBM437")
+          [Console]::InputEncoding  = [System.Text.Encoding]::GetEncoding("IBM437")
+          make DESTDIR=../install install-nodoc
+
+      - name: test
+        timeout-minutes: 5
+        run: |
+          make test
+
+      - name: test-all
+        timeout-minutes: 60
+        run: |
+          # Actions uses UTF8, causes test failures, similar to normal OS setup
+          $PSDefaultParameterValues['*:Encoding'] = 'utf8'
+          [Console]::OutputEncoding = [System.Text.Encoding]::GetEncoding("IBM437")
+          [Console]::InputEncoding  = [System.Text.Encoding]::GetEncoding("IBM437")
+          $jobs = [int](1.5 * $env:NUMBER_OF_PROCESSORS)
+          if ($env:BUNDLER_VERSION) { Remove-Item env:\BUNDLER_VERSION }
+          make test-all TESTOPTS="-j $jobs --retry --job-status=normal --show-skip --timeout-scale=1.5"
+
+      - name: test-spec
+        timeout-minutes: 10
+        working-directory: src/spec/ruby
+        run: |
+          $env:Path = "$pwd/../../../install/bin;$env:Path"
+          # Actions uses UTF8, causes test failures, similar to normal OS setup
+          $PSDefaultParameterValues['*:Encoding'] = 'utf8'
+          [Console]::OutputEncoding = [System.Text.Encoding]::GetEncoding("IBM437")
+          [Console]::InputEncoding  = [System.Text.Encoding]::GetEncoding("IBM437")
+          ruby -v
+          ruby ../mspec/bin/mspec -I../../tool/lib -j
+
+      - uses: k0kubun/action-slack@v2.0.0
+        with:
+          payload: |
+            {
+              "ci": "GitHub Actions",
+              "env": "${{ github.workflow }} ${{ matrix.msystem }} / ${{ matrix.test_task }}",
+              "url": "https://github.com/${{ github.repository }}/actions/runs/${{ github.run_id }}",
+              "commit": "${{ github.sha }}",
+              "branch": "${{ github.ref }}".split('/').reverse()[0]
+            }
+        env:
+          SLACK_WEBHOOK_URL: ${{ secrets.SIMPLER_ALERTS_URL }} # ruby-lang slack: ruby/simpler-alerts-bot
+        if: failure() && github.event_name == 'push'
+
+defaults:
+  run:
+    working-directory: build
diff --git a/.github/workflows/mjit.yml b/.github/workflows/mjit.yml
new file mode 100644
index 0000000000..8dcbcf7760
--- /dev/null
+++ b/.github/workflows/mjit.yml
@@ -0,0 +1,77 @@
+name: MJIT
+on: [push, pull_request]
+jobs:
+  make:
+    strategy:
+      matrix:
+        test_task: [check] # to make job names consistent
+        jit_opts: [--jit-wait]
+      fail-fast: false
+    runs-on: ubuntu-20.04
+    if: "!contains(github.event.head_commit.message, '[ci skip]')"
+    env:
+      TESTOPTS: '-q --tty=no'
+      RUN_OPTS: '--disable-gems ${{ matrix.jit_opts }} --jit-debug=-ggdb3'
+      GITPULLOPTIONS: --no-tags origin ${{github.ref}}
+    steps:
+      - run: mkdir build
+        working-directory:
+      - name: Install libraries
+        run: |
+          set -x
+          sudo apt-get update -q || :
+          sudo apt-get install --no-install-recommends -q -y build-essential libssl-dev libyaml-dev libreadline6-dev zlib1g-dev libncurses5-dev libffi-dev libgdbm-dev bison autoconf ruby
+      - name: git config
+        run: |
+          git config --global advice.detachedHead 0
+      - uses: actions/checkout@v2
+        with:
+          path: src
+      - name: Fixed world writable dirs
+        run: |
+          chmod -v go-w $HOME $HOME/.config
+          sudo chmod -R go-w /usr/share
+          sudo bash -c 'IFS=:; for d in '"$PATH"'; do chmod -v go-w $d; done' || :
+      - name: Set ENV
+        run: |
+          echo "GNUMAKEFLAGS=-j$((1 + $(nproc --all)))" >> $GITHUB_ENV
+      - run: ./autogen.sh
+        working-directory: src
+      - name: Run configure
+        run: ../src/configure -C --disable-install-doc cppflags=-DVM_CHECK_MODE
+      - run: make incs
+      - run: make
+      - run: sudo make -s install
+      - run: sudo apt-get install gdb # used by test / test-all failure
+      - name: Run test
+        run: |
+          ulimit -c unlimited
+          make -s test RUN_OPTS="$RUN_OPTS"
+        timeout-minutes: 60
+      # - name: Run test-all
+      #   run: |
+      #     ulimit -c unlimited
+      #     make -s test-all RUN_OPTS="$RUN_OPTS"
+      #   timeout-minutes: 60
+      - name: Run test-spec
+        run: |
+          ulimit -c unlimited
+          make -s test-spec RUN_OPTS="$RUN_OPTS"
+        timeout-minutes: 60
+      - uses: k0kubun/action-slack@v2.0.0
+        with:
+          payload: |
+            {
+              "ci": "GitHub Actions",
+              "env": "${{ github.workflow }} / ${{ matrix.test_task }} ${{ matrix.jit_opts }}",
+              "url": "https://github.com/${{ github.repository }}/actions/runs/${{ github.run_id }}",
+              "commit": "${{ github.sha }}",
+              "branch": "${{ github.ref }}".split('/').reverse()[0]
+            }
+        env:
+          SLACK_WEBHOOK_URL: ${{ secrets.SIMPLER_ALERTS_URL }} # ruby-lang slack: ruby/simpler-alerts-bot
+        if: failure() && github.event_name == 'push'
+
+defaults:
+  run:
+    working-directory: build
diff --git a/.github/workflows/spec_guards.yml b/.github/workflows/spec_guards.yml
new file mode 100644
index 0000000000..bf053cdd05
--- /dev/null
+++ b/.github/workflows/spec_guards.yml
@@ -0,0 +1,41 @@
+name: Rubyspec Version Guards Check
+
+on: [push, pull_request]
+
+jobs:
+  rubyspec:
+    name: Rubyspec
+    runs-on: ubuntu-20.04
+    if: "!contains(github.event.head_commit.message, '[ci skip]')"
+    strategy:
+      matrix:
+        # Specs from ruby/spec should still run on all supported Ruby versions.
+        # This also ensures the needed ruby_version_is guards are there, see spec/README.md.
+        ruby:
+          - ruby-2.5
+#         - ruby-2.6
+          - ruby-2.7
+          - ruby-3.0
+
+    steps:
+      - uses: actions/checkout@v2
+      - uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: ${{ matrix.ruby }}
+          bundler: none
+      - run: gem install webrick
+      - run: ruby ../mspec/bin/mspec
+        working-directory: spec/ruby
+      - uses: k0kubun/action-slack@v2.0.0
+        with:
+          payload: |
+            {
+              "ci": "GitHub Actions",
+              "env": "${{ github.workflow }} / rubyspec @ ${{ matrix.ruby }}",
+              "url": "https://github.com/${{ github.repository }}/actions/runs/${{ github.run_id }}",
+              "commit": "${{ github.sha }}",
+              "branch": "${{ github.ref }}".split('/').reverse()[0]
+            }
+        env:
+          SLACK_WEBHOOK_URL: ${{ secrets.SIMPLER_ALERTS_URL }} # ruby-lang slack: ruby/simpler-alerts-bot
+        if: failure() && github.event_name == 'push'
diff --git a/.github/workflows/ubuntu.yml b/.github/workflows/ubuntu.yml
new file mode 100644
index 0000000000..93187699be
--- /dev/null
+++ b/.github/workflows/ubuntu.yml
@@ -0,0 +1,87 @@
+name: Ubuntu
+on: [push, pull_request]
+jobs:
+  make:
+    strategy:
+      matrix:
+        test_task: [ "check", "test-bundler-parallel", "test-bundled-gems", "test-all TESTS=--repeat-count=2" ]
+        os:
+          - ubuntu-20.04
+#         - ubuntu-18.04
+#         - ubuntu-16.04
+        debug: ["", "-DRUBY_DEBUG"]
+        exclude:
+          - test_task: test-bundler-parallel
+            os: ubuntu-16.04
+          - test_task: test-bundled-gems
+            os: ubuntu-16.04
+          - test_task: "test-all TESTS=--repeat-count=2"
+            os: ubuntu-16.04
+          - os: ubuntu-16.04
+            debug: -DRUBY_DEBUG
+          - test_task: "test-all TESTS=--repeat-count=2"
+            debug: -DRUBY_DEBUG
+      fail-fast: false
+    env:
+      GITPULLOPTIONS: --no-tags origin ${{github.ref}}
+      RUBY_DEBUG: ci
+    runs-on: ${{ matrix.os }}
+    if: "!contains(github.event.head_commit.message, '[ci skip]')"
+    steps:
+      - run: mkdir build
+        working-directory:
+      - name: Install libraries
+        run: |
+          set -x
+          sudo apt-get update -q || :
+          sudo apt-get install --no-install-recommends -q -y build-essential libssl-dev libyaml-dev libreadline6-dev zlib1g-dev libncurses5-dev libffi-dev libgdbm-dev bison autoconf ruby
+      - name: git config
+        run: |
+          git config --global advice.detachedHead 0
+      - uses: actions/checkout@v2
+        with:
+          path: src
+      - name: Fixed world writable dirs
+        run: |
+          chmod -v go-w $HOME $HOME/.config
+          sudo chmod -R go-w /usr/share
+          sudo bash -c 'IFS=:; for d in '"$PATH"'; do chmod -v go-w $d; done' || :
+      - name: Set ENV
+        run: |
+          echo "JOBS=-j$((1 + $(nproc --all)))" >> $GITHUB_ENV
+      - run: ./autogen.sh
+        working-directory: src
+      - name: Run configure
+        run: ../src/configure -C --disable-install-doc cppflags=${{ matrix.debug }}
+      - run: make $JOBS incs
+      - run: make $JOBS
+      - run: make leaked-globals
+        if: matrix.test_task == 'check'
+      - run: make prepare-gems
+        if: matrix.test_task == 'check'
+      - name: Create dummy files in build dir
+        run: |
+          ./miniruby -e '(("a".."z").to_a+("A".."Z").to_a+("0".."9").to_a+%w[foo bar test zzz]).each{|basename|File.write("#{basename}.rb", "raise %(do not load #{basename}.rb)")}'
+        if: matrix.test_task == 'check'
+      - run: make $JOBS -s ${{ matrix.test_task }}
+        timeout-minutes: 30
+        env:
+          RUBY_TESTOPTS: "-q --tty=no"
+          TEST_BUNDLED_GEMS_ALLOW_FAILURES: ""
+      - uses: k0kubun/action-slack@v2.0.0
+        with:
+          payload: |
+            {
+              "ci": "GitHub Actions",
+              "env": "${{ matrix.os }} / ${{ matrix.test_task }}${{ matrix.debug }}",
+              "url": "https://github.com/${{ github.repository }}/actions/runs/${{ github.run_id }}",
+              "commit": "${{ github.sha }}",
+              "branch": "${{ github.ref }}".split('/').reverse()[0]
+            }
+        env:
+          SLACK_WEBHOOK_URL: ${{ secrets.SIMPLER_ALERTS_URL }} # ruby-lang slack: ruby/simpler-alerts-bot
+        if: failure() && github.event_name == 'push'
+
+defaults:
+  run:
+    working-directory: build
diff --git a/.github/workflows/windows.yml b/.github/workflows/windows.yml
new file mode 100644
index 0000000000..98e59ae188
--- /dev/null
+++ b/.github/workflows/windows.yml
@@ -0,0 +1,80 @@
+name: Windows
+on: [push, pull_request]
+jobs:
+  make:
+    strategy:
+      matrix:
+        test_task: [test]
+        os: [windows-2019]
+        vs: [2019]
+      fail-fast: false
+    runs-on: ${{ matrix.os }}
+    env:
+      GITPULLOPTIONS: --no-tags origin ${{github.ref}}
+      VCVARS: C:\Program Files (x86)\Microsoft Visual Studio\${{ matrix.vs }}\Enterprise\VC\Auxiliary\Build\vcvars64.bat
+    if: "!contains(github.event.head_commit.message, '[ci skip]')"
+    steps:
+      - run: md build
+        working-directory:
+      - uses: actions/cache@v2
+        with:
+          path: C:\vcpkg\downloads
+          key: ${{ runner.os }}-vcpkg-download-${{ matrix.os }}-${{ github.sha }}
+          restore-keys: |
+            ${{ runner.os }}-vcpkg-download-${{ matrix.os }}-
+            ${{ runner.os }}-vcpkg-download-
+      - name: Install libraries with vcpkg
+        run: |
+          vcpkg --triplet x64-windows install readline zlib
+      - uses: actions/cache@v2
+        with:
+          path: C:\Users\runneradmin\AppData\Local\Temp\chocolatey
+          key: ${{ runner.os }}-chocolatey-${{ matrix.os }}-${{ github.sha }}
+          restore-keys: |
+            ${{ runner.os }}-chocolatey-${{ matrix.os }}-
+            ${{ runner.os }}-chocolatey-
+      - name: Install libraries with chocolatey
+        run: |
+          choco install --no-progress openssl
+          choco install --no-progress winflexbison3 --version=2.5.18.20190508
+      - name: git config
+        run: |
+          git config --system advice.detachedHead 0
+      - uses: actions/checkout@v2
+        with:
+          path: src
+      - name: Configure
+        run: |
+          call "%VCVARS%"
+          ../src/win32/configure.bat --disable-install-doc --without-ext=+,dbm,gdbm --enable-bundled-libffi --with-opt-dir=C:/vcpkg/installed/x64-windows --with-openssl-dir="C:/Program Files/OpenSSL-Win64"
+      - name: nmake
+        run: |
+          call "%VCVARS%"
+          set YACC=win_bison
+          echo on
+          nmake incs
+          nmake extract-extlibs
+          nmake
+      - name: nmake test
+        timeout-minutes: 30
+        run: |
+          call "%VCVARS%"
+          nmake ${{ matrix.test_task }}
+      - uses: k0kubun/action-slack@v2.0.0
+        with:
+          payload: |
+            {
+              "ci": "GitHub Actions",
+              "env": "${{ matrix.os }} / ${{ matrix.test_task }}",
+              "url": "https://github.com/${{ github.repository }}/actions/runs/${{ github.run_id }}",
+              "commit": "${{ github.sha }}",
+              "branch": "${{ github.ref }}".split('/').reverse()[0]
+            }
+        env:
+          SLACK_WEBHOOK_URL: ${{ secrets.SIMPLER_ALERTS_URL }} # ruby-lang slack: ruby/simpler-alerts-bot
+        if: failure() && github.event_name == 'push'
+
+defaults:
+  run:
+    working-directory: build
+    shell: cmd
diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000000..8d11d7278a
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,230 @@
+*-*-*.def
+*-*-*.exp
+*-*-*.lib
+*.a
+*.bak
+*.bc
+*.bundle
+*.dSYM
+*.dmyh
+*.dylib
+*.elc
+*.i
+*.inc
+*.log
+*.o
+*.obj
+*.old
+*.orig
+*.pch
+*.pdb
+*.rbinc
+*.rej
+*.s
+*.sav
+*.sl
+*.so
+*.swp
+*.yarb
+*~
+.*.list
+.*.time
+.DS_Store
+.bundle
+.ccmalloc
+.ext
+.pc
+.ppack
+.svn
+.time
+.ruby-version
+Makefile
+cygruby*.def
+extconf.h
+y.output
+y.tab.c
+*.gcda
+*.gcno
+*.gcov
+*.vscode
+lcov*.info
+
+# /
+/*-fake.rb
+/*.dll
+/*.exe
+/*.res
+/*.pc
+/*.rc
+/*_prelude.c
+/.downloaded-cache
+/.top-enc.mk
+/build*/
+/COPYING.LIB
+/ChangeLog
+/Doxyfile
+/GNUmakefile
+/README.atheos
+/README.fat-patch
+/README.v6
+/TAGS
+/archive
+/autom4te*.cache
+/automake
+/benchmark/benchmark-driver
+/beos
+/bmlog-*
+/breakpoints.gdb
+/config.cache
+/config.h
+/config.h.in
+/config.status
+/config.status.lineno
+/configure
+/coverage/simplecov
+/coverage/simplecov-html
+/coverage/doclie
+/coverage/.last_run.json
+/coverage/.resultset.json*
+/coverage/assets
+/coverage/index.html
+/doc/capi
+/enc.mk
+/encdb.h
+/exts.mk
+/goruby
+/id.[ch]
+/largefile.h
+/lcov-c-out
+/lcov-rb-out
+/lcov-out
+/lex.c
+/libruby*.*
+/miniprelude.c
+/miniruby
+/newdate.rb
+/newline.c
+/newver.rb
+/parse.c
+/parse.h
+/patches
+/patches-master
+/pitest.rb
+/ppack
+/prelude.c
+/preview
+/probes.dmyh
+/probes.h
+/rbconfig.rb
+/rename2.h
+/repack
+/revision.h
+/revision.tmp
+/riscos
+/rubicon
+/ruby
+/ruby-runner
+/ruby-runner.h
+/ruby-man.rd.gz
+/run.gdb
+/sizes.c
+/static-ruby
+/test.rb
+/test-coverage.dat
+/tmp
+/transdb.h
+/uncommon.mk
+/verconf.h
+/verconf.mk
+/web
+/yasmdata.rb
+
+# /bin/
+
+/bin/*.exe
+/bin/*.dll
+
+# /benchmark/
+/benchmark/bm_require.data
+/benchmark/bmx_*.rb
+/benchmark/fasta.output.*
+/benchmark/wc.input
+
+/enc/*.def
+/enc/*.exp
+/enc/*.lib
+/enc/jis/props.h
+/enc/unicode/data
+
+# /coroutine/
+!/coroutine/**/*.s
+
+# /enc/trans/
+/enc/trans/*.c
+/enc/trans/*.def
+/enc/trans/*.exp
+/enc/trans/*.lib
+
+# /exe/
+/exe/goruby
+/exe/ruby
+
+# /ext/
+/ext/extinit.c
+/ext/configure-ext.mk
+/ext/*/exts.mk
+
+# /ext/-test-/cxxanyargs
+/ext/-test-/cxxanyargs/failure*.failed
+
+# /ext/-test-/win32/dln/
+/ext/-test-/win32/dln/dlntest.dll
+/ext/-test-/win32/dln/dlntest.exp
+/ext/-test-/win32/dln/dlntest.lib
+
+# /ext/etc/
+/ext/etc/constdefs.h
+
+# /ext/fiddle/
+/ext/fiddle/libffi-*
+
+# /ext/rbconfig/
+/ext/rbconfig/sizeof/sizes.c
+/ext/rbconfig/sizeof/limits.c
+
+# /ext/ripper/
+/ext/ripper/eventids1.c
+/ext/ripper/.eventids2-check
+/ext/ripper/eventids2table.c
+/ext/ripper/ripper.*
+/ext/ripper/ids1
+/ext/ripper/ids2
+
+# /ext/socket/
+/ext/socket/constants.h
+/ext/socket/constdefs.h
+/ext/socket/constdefs.c
+
+# /gems
+/gems/*.gem
+/gems/src
+/gems/*-*
+
+# /lib/
+/lib/ruby/[1-9]*.*
+/lib/ruby/vendor_ruby
+
+# /spec/bundler
+/.rspec_status
+
+# /tool/
+/tool/config.guess
+/tool/config.sub
+
+# /win32/
+/win32/*.ico
+
+# MJIT
+/rb_mjit_header.h
+/mjit_config.h
+/include/ruby-*/*/rb_mjit_min_header-*.h
diff --git a/.rspec_parallel b/.rspec_parallel
new file mode 100644
index 0000000000..aaff198a32
--- /dev/null
+++ b/.rspec_parallel
@@ -0,0 +1,2 @@
+--format progress
+--format ParallelTests::RSpec::RuntimeLogger --out tmp/parallel_runtime_rspec.log
diff --git a/.travis.yml b/.travis.yml
new file mode 100644
index 0000000000..d480307dd6
--- /dev/null
+++ b/.travis.yml
@@ -0,0 +1,291 @@
+# -*- YAML -*-
+# Copyright (C) 2011 Urabe, Shyouhei.  All rights reserved.
+#
+# This file is  a part of the programming language  Ruby.  Permission is hereby
+# granted,  to either  redistribute  or  modify this  file,  provided that  the
+# conditions  mentioned in  the file  COPYING are  met.  Consult  the  file for
+# details.
+
+# This is  a Travis-CI  build configuration file.   The list  of configurations
+# available is located in
+#
+#     http://about.travis-ci.org/docs/user/build-configuration/
+#
+# and as Ruby itself is a project written in C language,
+#
+#     http://about.travis-ci.org/docs/user/languages/c/
+#
+# is also a good place to look at.
+
+language: c
+
+os: linux
+
+dist: xenial
+
+git:
+  quiet: true
+
+cache:
+  ccache: true
+  directories:
+    - $HOME/config_2nd
+    - $HOME/.downloaded-cache
+
+env:
+  global:
+    # Reset timestamps early
+    - _=$(touch NEWS && find . -type f -exec touch -r NEWS {} +)
+    - CONFIGURE_TTY=no
+    - CCACHE_COMPILERCHECK=none
+    - CCACHE_NOCOMPRESS=1
+    - CCACHE_MAXSIZE=512Mi
+    - NPROC="`nproc`"
+    # JOBS and SETARCH are overridden when necessary; see below.
+    - JOBS=-j$((1+${NPROC}))
+    - SETARCH=
+    - RUBY_PREFIX=/tmp/ruby-prefix
+    - GEMS_FOR_TEST='timezone tzinfo'
+    - UPDATE_UNICODE="UNICODE_FILES=. UNICODE_PROPERTY_FILES=. UNICODE_AUXILIARY_FILES=. UNICODE_EMOJI_FILES=."
+    - BEFORE_INSTALL=true
+    # https://github.com/travis-ci/travis-build/blob/e411371dda21430a60f61b8f3f57943d2fe4d344/lib/travis/build/bash/travis_apt_get_options.bash#L7
+    - travis_apt_get_options='--allow-downgrades --allow-remove-essential --allow-change-held-packages'
+    - travis_apt_get_options="-yq --no-install-suggests --no-install-recommends $travis_apt_get_options"
+
+.org.ruby-lang.ci.matrix-definitions:
+
+  - &make-test-only
+    script:
+      - $SETARCH make -s test TESTOPTS="${TESTOPTS=$JOBS -q --tty=no}"
+
+  - &gcc-8
+    compiler: gcc-8
+    # # Not using addon to control retries
+    # addons:
+    #   apt:
+    #     sources:
+    #       - ubuntu-toolchain-r-test
+    before_install:
+      - bash -cx "${BEFORE_INSTALL}"
+      - tool/travis_retry.sh sudo -E apt-add-repository -y "ppa:ubuntu-toolchain-r/test"
+      - tool/travis_retry.sh sudo bash -c "rm -rf '${TRAVIS_ROOT}/var/lib/apt/lists/'* && exec apt-get update -yq"
+      - >-
+        tool/travis_retry.sh sudo -E apt-get $travis_apt_get_options install
+        ccache
+        gcc-8
+        g++-8
+        libffi-dev
+        libgdbm-dev
+        libncurses5-dev
+        libncursesw5-dev
+        libreadline6-dev
+        libssl-dev
+        libyaml-dev
+        openssl
+        zlib1g-dev
+
+  - &clang-8
+    compiler: clang-8
+    addons:
+      apt:
+        # Not doing this manually unlike other sources, because it has been stable.
+        sources:
+          - llvm-toolchain-xenial-8
+        config:
+          retries: true
+    before_install:
+      - tool/travis_retry.sh sudo bash -c "rm -rf '${TRAVIS_ROOT}/var/lib/apt/lists/'* && exec apt-get update -yq"
+      - >-
+        tool/travis_retry.sh sudo -E apt-get $travis_apt_get_options install
+        clang-8
+        llvm-8-tools
+        libffi-dev
+        libgdbm-dev
+        libncurses5-dev
+        libncursesw5-dev
+        libreadline6-dev
+        libssl-dev
+        libyaml-dev
+        openssl
+        zlib1g-dev
+
+  # --------
+
+  - &x86_64-linux
+    name: x86_64-linux
+    <<: *gcc-8
+
+  - &arm64-linux
+    name: arm64-linux
+    arch: arm64
+    <<: *gcc-8
+
+  - &s390x-linux
+    name: s390x-linux
+    arch: s390x
+    <<: *gcc-8
+
+  - &i686-linux
+    name: i686-linux
+    compiler: gcc-8
+    env:
+      - GCC_FLAGS=-m32
+      - CXX='g++-8 -m32'
+      - debugflags=-g0
+      - SETARCH='setarch i686 --verbose --3gb'
+    # # Not using addon to control retries
+    # addons:
+    #   apt:
+    #     sources:
+    #       - ubuntu-toolchain-r-test
+    before_install:
+      - tool/travis_retry.sh sudo -E apt-add-repository -y "ppa:ubuntu-toolchain-r/test"
+      - tool/travis_retry.sh sudo bash -c "rm -rf '${TRAVIS_ROOT}/var/lib/apt/lists/'* && exec apt-get update -yq"
+      - >-
+        tool/travis_retry.sh sudo -E apt-get $travis_apt_get_options install
+        gcc-8-multilib
+        g++-8
+        g++-8-multilib
+        libstdc++-8-dev:i386
+        libffi-dev:i386
+        libffi6:i386
+        libgdbm-dev:i386
+        libgdbm3:i386
+        libncurses5-dev:i386
+        libncurses5:i386
+        libncursesw5-dev:i386
+        libreadline6-dev:i386
+        libreadline6:i386
+        libssl-dev:i386
+        libssl1.0.0:i386
+        linux-libc-dev:i386
+        zlib1g-dev:i386
+        zlib1g:i386
+
+  - &arm32-linux
+    name: arm32-linux
+    arch: arm64
+    # https://packages.ubuntu.com/xenial/crossbuild-essential-armhf
+    compiler: arm-linux-gnueabihf-gcc
+    env:
+      - debugflags=-g0
+      - SETARCH='setarch linux32 --verbose --32bit'
+    before_install:
+      - sudo dpkg --add-architecture armhf
+      - tool/travis_retry.sh sudo bash -c "rm -rf '${TRAVIS_ROOT}/var/lib/apt/lists/'* && exec apt-get update -yq"
+      - >-
+        tool/travis_retry.sh sudo -E apt-get $travis_apt_get_options install
+        ccache
+        crossbuild-essential-armhf
+        libc6:armhf
+        libstdc++-5-dev:armhf
+        libffi-dev:armhf
+        libffi6:armhf
+        libgdbm-dev:armhf
+        libgdbm3:armhf
+        libncurses5-dev:armhf
+        libncurses5:armhf
+        libncursesw5-dev:armhf
+        libreadline6-dev:armhf
+        libreadline6:armhf
+        libssl-dev:armhf
+        libssl1.0.0:armhf
+        linux-libc-dev:armhf
+        zlib1g-dev:armhf
+        zlib1g:armhf
+
+matrix:
+  include:
+    # Build every commit:
+    - <<: *i686-linux
+    # Build every commit (Allowed Failures):
+    - <<: *arm32-linux
+    - <<: *arm64-linux
+    - <<: *s390x-linux
+  allow_failures:
+    - name: arm32-linux
+    - name: arm64-linux
+    - name: s390x-linux
+  fast_finish: true
+
+before_script:
+  - rm -fr .ext autom4te.cache
+  - |-
+    [ -d ~/.downloaded-cache ] ||
+    mkdir ~/.downloaded-cache
+  - ln -s ~/.downloaded-cache
+  - "> config.status"
+  - "> .rbconfig.time"
+  - sed -f tool/prereq.status template/Makefile.in common.mk > Makefile
+  - make touch-unicode-files
+  - make -s $JOBS $UPDATE_UNICODE up
+  - make -s $JOBS srcs
+  - rm -f config.status Makefile rbconfig.rb .rbconfig.time
+  - |-
+    if [ -d ~/config_2nd ]; then
+      cp -pr ~/config_2nd build
+    else
+      mkdir build
+    fi
+  - mkdir config_1st config_2nd
+  - chmod -R a-w .
+  - chmod -R u+w build config_1st config_2nd
+  - cd build
+  - |-
+    case "$CC" in
+    gcc*)   CC="ccache $CC${GCC_FLAGS:+ }$GCC_FLAGS -fno-diagnostics-color";;
+    clang*) CC="ccache $CC${GCC_FLAGS:+ }$GCC_FLAGS -fno-color-diagnostics";;
+    esac
+  - |-
+    [ ! -f config.cache ] ||
+    [ "$CC" = "`sed -n s/^ac_cv_prog_CC=//p config.cache`" ] ||
+    (set -x; exec rm config.cache)
+  - $SETARCH ../configure -C --disable-install-doc --prefix=$RUBY_PREFIX $CONFIG_FLAG
+  - cp -pr config.cache config.status .ext/include ../config_1st
+  - $SETARCH make reconfig
+  - cp -pr config.cache config.status .ext/include ../config_2nd
+  - (cd .. && exec diff -ru config_1st config_2nd)
+  - chmod u+w ..
+  - rm -rf ~/config_2nd
+  - mv ../config_2nd ~
+  - chmod u-w ..
+  - $SETARCH make -s $JOBS
+  - make -s install
+  - |-
+    [ -z "${GEMS_FOR_TEST}" ] ||
+    $RUBY_PREFIX/bin/gem install --no-document $GEMS_FOR_TEST
+  - echo "raise 'do not load ~/.irbrc in test'" > ~/.irbrc
+
+script:
+  - $SETARCH make -s test -o showflags TESTOPTS="${TESTOPTS=$JOBS -q --tty=no}"
+  - travis_wait 50 $SETARCH make -s test-all -o exts TESTOPTS="${TESTOPTS} ${TEST_ALL_OPTS}" RUBYOPT="-w"
+  - $SETARCH make -s test-spec MSPECOPT=-ff # not using `-j` because sometimes `mspec -j` silently dies
+  - $SETARCH make -s -o showflags leaked-globals
+
+# Branch matrix.  Not all branches are Travis-ready so we limit branches here.
+branches:
+  only:
+    - master
+    - ruby_2_4
+    - ruby_2_5
+    - ruby_2_6
+    - ruby_2_7
+
+# We want to be notified when something happens.
+notifications:
+  irc:
+    channels:
+      - "chat.freenode.net#ruby-core"
+    on_success: change # [always|never|change] # default: always
+    on_failure: always # [always|never|change] # default: always
+    template:
+      - "%{message} by @%{author}: See %{build_url}"
+
+  webhooks:
+    urls:
+      - secure: mRsoS/UbqDkKkW5p3AEqM27d4SZnV6Gsylo3bm8T/deltQzTsGzZwrm7OIBXZv0UFZdE68XmPlyHfZFLSP2V9QZ7apXMf9/vw0GtcSe1gchtnjpAPF6lYBn7nMCbVPPx9cS0dwL927fjdRM1vj7IKZ2bk4F0lAJ25R25S6teqdk= # ruby-lang slack: ruby/simpler-alerts-bot (travis)
+    on_success: never
+    on_failure: always
+
+  email:
+    - ko1c-failure@atdot.net
diff --git a/BSDL b/BSDL
new file mode 100644
index 0000000000..66d93598aa
--- /dev/null
+++ b/BSDL
@@ -0,0 +1,22 @@
+Copyright (C) 1993-2013 Yukihiro Matsumoto. All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions
+are met:
+1. Redistributions of source code must retain the above copyright
+   notice, this list of conditions and the following disclaimer.
+2. Redistributions in binary form must reproduce the above copyright
+   notice, this list of conditions and the following disclaimer in the
+   documentation and/or other materials provided with the distribution.
+
+THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+SUCH DAMAGE.
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
new file mode 100644
index 0000000000..ffdf2dd4b8
--- /dev/null
+++ b/CONTRIBUTING.md
@@ -0,0 +1,4 @@
+Please see the [official issue tracker] and wiki [HowToContribute].
+
+[official issue tracker]: https://bugs.ruby-lang.org
+[HowToContribute]: https://bugs.ruby-lang.org/projects/ruby/wiki/HowToContribute
diff --git a/COPYING b/COPYING
index eeb586b392..48e5a96de7 100644
--- a/COPYING
+++ b/COPYING
@@ -1,340 +1,56 @@
-		    GNU GENERAL PUBLIC LICENSE
-		       Version 2, June 1991
+Ruby is copyrighted free software by Yukihiro Matsumoto <matz@netlab.jp>.
+You can redistribute it and/or modify it under either the terms of the
+2-clause BSDL (see the file BSDL), or the conditions below:
 
- Copyright (C) 1989, 1991 Free Software Foundation, Inc.
-     59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
- Everyone is permitted to copy and distribute verbatim copies
- of this license document, but changing it is not allowed.
+1. You may make and give away verbatim copies of the source form of the
+   software without restriction, provided that you duplicate all of the
+   original copyright notices and associated disclaimers.
 
-			    Preamble
+2. You may modify your copy of the software in any way, provided that
+   you do at least ONE of the following:
 
-  The licenses for most software are designed to take away your
-freedom to share and change it.  By contrast, the GNU General Public
-License is intended to guarantee your freedom to share and change free
-software--to make sure the software is free for all its users.  This
-General Public License applies to most of the Free Software
-Foundation's software and to any other program whose authors commit to
-using it.  (Some other Free Software Foundation software is covered by
-the GNU Library General Public License instead.)  You can apply it to
-your programs, too.
+   a. place your modifications in the Public Domain or otherwise
+      make them Freely Available, such as by posting said
+      modifications to Usenet or an equivalent medium, or by allowing
+      the author to include your modifications in the software.
 
-  When we speak of free software, we are referring to freedom, not
-price.  Our General Public Licenses are designed to make sure that you
-have the freedom to distribute copies of free software (and charge for
-this service if you wish), that you receive source code or can get it
-if you want it, that you can change the software or use pieces of it
-in new free programs; and that you know you can do these things.
+   b. use the modified software only within your corporation or
+      organization.
 
-  To protect your rights, we need to make restrictions that forbid
-anyone to deny you these rights or to ask you to surrender the rights.
-These restrictions translate to certain responsibilities for you if you
-distribute copies of the software, or if you modify it.
+   c. give non-standard binaries non-standard names, with
+      instructions on where to get the original software distribution.
 
-  For example, if you distribute copies of such a program, whether
-gratis or for a fee, you must give the recipients all the rights that
-you have.  You must make sure that they, too, receive or can get the
-source code.  And you must show them these terms so they know their
-rights.
+   d. make other distribution arrangements with the author.
 
-  We protect your rights with two steps: (1) copyright the software, and
-(2) offer you this license which gives you legal permission to copy,
-distribute and/or modify the software.
+3. You may distribute the software in object code or binary form,
+   provided that you do at least ONE of the following:
 
-  Also, for each author's protection and ours, we want to make certain
-that everyone understands that there is no warranty for this free
-software.  If the software is modified by someone else and passed on, we
-want its recipients to know that what they have is not the original, so
-that any problems introduced by others will not reflect on the original
-authors' reputations.
+   a. distribute the binaries and library files of the software,
+      together with instructions (in the manual page or equivalent)
+      on where to get the original distribution.
 
-  Finally, any free program is threatened constantly by software
-patents.  We wish to avoid the danger that redistributors of a free
-program will individually obtain patent licenses, in effect making the
-program proprietary.  To prevent this, we have made it clear that any
-patent must be licensed for everyone's free use or not licensed at all.
+   b. accompany the distribution with the machine-readable source of
+      the software.
 
-  The precise terms and conditions for copying, distribution and
-modification follow.
-
-		    GNU GENERAL PUBLIC LICENSE
-   TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
+   c. give non-standard binaries non-standard names, with
+      instructions on where to get the original software distribution.
 
-  0. This License applies to any program or other work which contains
-a notice placed by the copyright holder saying it may be distributed
-under the terms of this General Public License.  The "Program", below,
-refers to any such program or work, and a "work based on the Program"
-means either the Program or any derivative work under copyright law:
-that is to say, a work containing the Program or a portion of it,
-either verbatim or with modifications and/or translated into another
-language.  (Hereinafter, translation is included without limitation in
-the term "modification".)  Each licensee is addressed as "you".
+   d. make other distribution arrangements with the author.
 
-Activities other than copying, distribution and modification are not
-covered by this License; they are outside its scope.  The act of
-running the Program is not restricted, and the output from the Program
-is covered only if its contents constitute a work based on the
-Program (independent of having been made by running the Program).
-Whether that is true depends on what the Program does.
+4. You may modify and include the part of the software into any other
+   software (possibly commercial).  But some files in the distribution
+   are not written by the author, so that they are not under these terms.
 
-  1. You may copy and distribute verbatim copies of the Program's
-source code as you receive it, in any medium, provided that you
-conspicuously and appropriately publish on each copy an appropriate
-copyright notice and disclaimer of warranty; keep intact all the
-notices that refer to this License and to the absence of any warranty;
-and give any other recipients of the Program a copy of this License
-along with the Program.
+   For the list of those files and their copying conditions, see the
+   file LEGAL.
 
-You may charge a fee for the physical act of transferring a copy, and
-you may at your option offer warranty protection in exchange for a fee.
+5. The scripts and library files supplied as input to or produced as
+   output from the software do not automatically fall under the
+   copyright of the software, but belong to whomever generated them,
+   and may be sold commercially, and may be aggregated with this
+   software.
 
-  2. You may modify your copy or copies of the Program or any portion
-of it, thus forming a work based on the Program, and copy and
-distribute such modifications or work under the terms of Section 1
-above, provided that you also meet all of these conditions:
-
-    a) You must cause the modified files to carry prominent notices
-    stating that you changed the files and the date of any change.
-
-    b) You must cause any work that you distribute or publish, that in
-    whole or in part contains or is derived from the Program or any
-    part thereof, to be licensed as a whole at no charge to all third
-    parties under the terms of this License.
-
-    c) If the modified program normally reads commands interactively
-    when run, you must cause it, when started running for such
-    interactive use in the most ordinary way, to print or display an
-    announcement including an appropriate copyright notice and a
-    notice that there is no warranty (or else, saying that you provide
-    a warranty) and that users may redistribute the program under
-    these conditions, and telling the user how to view a copy of this
-    License.  (Exception: if the Program itself is interactive but
-    does not normally print such an announcement, your work based on
-    the Program is not required to print an announcement.)
-
-These requirements apply to the modified work as a whole.  If
-identifiable sections of that work are not derived from the Program,
-and can be reasonably considered independent and separate works in
-themselves, then this License, and its terms, do not apply to those
-sections when you distribute them as separate works.  But when you
-distribute the same sections as part of a whole which is a work based
-on the Program, the distribution of the whole must be on the terms of
-this License, whose permissions for other licensees extend to the
-entire whole, and thus to each and every part regardless of who wrote it.
-
-Thus, it is not the intent of this section to claim rights or contest
-your rights to work written entirely by you; rather, the intent is to
-exercise the right to control the distribution of derivative or
-collective works based on the Program.
-
-In addition, mere aggregation of another work not based on the Program
-with the Program (or with a work based on the Program) on a volume of
-a storage or distribution medium does not bring the other work under
-the scope of this License.
-
-  3. You may copy and distribute the Program (or a work based on it,
-under Section 2) in object code or executable form under the terms of
-Sections 1 and 2 above provided that you also do one of the following:
-
-    a) Accompany it with the complete corresponding machine-readable
-    source code, which must be distributed under the terms of Sections
-    1 and 2 above on a medium customarily used for software interchange; or,
-
-    b) Accompany it with a written offer, valid for at least three
-    years, to give any third party, for a charge no more than your
-    cost of physically performing source distribution, a complete
-    machine-readable copy of the corresponding source code, to be
-    distributed under the terms of Sections 1 and 2 above on a medium
-    customarily used for software interchange; or,
-
-    c) Accompany it with the information you received as to the offer
-    to distribute corresponding source code.  (This alternative is
-    allowed only for noncommercial distribution and only if you
-    received the program in object code or executable form with such
-    an offer, in accord with Subsection b above.)
-
-The source code for a work means the preferred form of the work for
-making modifications to it.  For an executable work, complete source
-code means all the source code for all modules it contains, plus any
-associated interface definition files, plus the scripts used to
-control compilation and installation of the executable.  However, as a
-special exception, the source code distributed need not include
-anything that is normally distributed (in either source or binary
-form) with the major components (compiler, kernel, and so on) of the
-operating system on which the executable runs, unless that component
-itself accompanies the executable.
-
-If distribution of executable or object code is made by offering
-access to copy from a designated place, then offering equivalent
-access to copy the source code from the same place counts as
-distribution of the source code, even though third parties are not
-compelled to copy the source along with the object code.
-
-  4. You may not copy, modify, sublicense, or distribute the Program
-except as expressly provided under this License.  Any attempt
-otherwise to copy, modify, sublicense or distribute the Program is
-void, and will automatically terminate your rights under this License.
-However, parties who have received copies, or rights, from you under
-this License will not have their licenses terminated so long as such
-parties remain in full compliance.
-
-  5. You are not required to accept this License, since you have not
-signed it.  However, nothing else grants you permission to modify or
-distribute the Program or its derivative works.  These actions are
-prohibited by law if you do not accept this License.  Therefore, by
-modifying or distributing the Program (or any work based on the
-Program), you indicate your acceptance of this License to do so, and
-all its terms and conditions for copying, distributing or modifying
-the Program or works based on it.
-
-  6. Each time you redistribute the Program (or any work based on the
-Program), the recipient automatically receives a license from the
-original licensor to copy, distribute or modify the Program subject to
-these terms and conditions.  You may not impose any further
-restrictions on the recipients' exercise of the rights granted herein.
-You are not responsible for enforcing compliance by third parties to
-this License.
-
-  7. If, as a consequence of a court judgment or allegation of patent
-infringement or for any other reason (not limited to patent issues),
-conditions are imposed on you (whether by court order, agreement or
-otherwise) that contradict the conditions of this License, they do not
-excuse you from the conditions of this License.  If you cannot
-distribute so as to satisfy simultaneously your obligations under this
-License and any other pertinent obligations, then as a consequence you
-may not distribute the Program at all.  For example, if a patent
-license would not permit royalty-free redistribution of the Program by
-all those who receive copies directly or indirectly through you, then
-the only way you could satisfy both it and this License would be to
-refrain entirely from distribution of the Program.
-
-If any portion of this section is held invalid or unenforceable under
-any particular circumstance, the balance of the section is intended to
-apply and the section as a whole is intended to apply in other
-circumstances.
-
-It is not the purpose of this section to induce you to infringe any
-patents or other property right claims or to contest validity of any
-such claims; this section has the sole purpose of protecting the
-integrity of the free software distribution system, which is
-implemented by public license practices.  Many people have made
-generous contributions to the wide range of software distributed
-through that system in reliance on consistent application of that
-system; it is up to the author/donor to decide if he or she is willing
-to distribute software through any other system and a licensee cannot
-impose that choice.
-
-This section is intended to make thoroughly clear what is believed to
-be a consequence of the rest of this License.
-
-  8. If the distribution and/or use of the Program is restricted in
-certain countries either by patents or by copyrighted interfaces, the
-original copyright holder who places the Program under this License
-may add an explicit geographical distribution limitation excluding
-those countries, so that distribution is permitted only in or among
-countries not thus excluded.  In such case, this License incorporates
-the limitation as if written in the body of this License.
-
-  9. The Free Software Foundation may publish revised and/or new versions
-of the General Public License from time to time.  Such new versions will
-be similar in spirit to the present version, but may differ in detail to
-address new problems or concerns.
-
-Each version is given a distinguishing version number.  If the Program
-specifies a version number of this License which applies to it and "any
-later version", you have the option of following the terms and conditions
-either of that version or of any later version published by the Free
-Software Foundation.  If the Program does not specify a version number of
-this License, you may choose any version ever published by the Free Software
-Foundation.
-
-  10. If you wish to incorporate parts of the Program into other free
-programs whose distribution conditions are different, write to the author
-to ask for permission.  For software which is copyrighted by the Free
-Software Foundation, write to the Free Software Foundation; we sometimes
-make exceptions for this.  Our decision will be guided by the two goals
-of preserving the free status of all derivatives of our free software and
-of promoting the sharing and reuse of software generally.
-
-			    NO WARRANTY
-
-  11. BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY
-FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW.  EXCEPT WHEN
-OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES
-PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED
-OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
-MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.  THE ENTIRE RISK AS
-TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU.  SHOULD THE
-PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING,
-REPAIR OR CORRECTION.
-
-  12. IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
-WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR
-REDISTRIBUTE THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES,
-INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING
-OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED
-TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY
-YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER
-PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE
-POSSIBILITY OF SUCH DAMAGES.
-
-		     END OF TERMS AND CONDITIONS
-
-	    How to Apply These Terms to Your New Programs
-
-  If you develop a new program, and you want it to be of the greatest
-possible use to the public, the best way to achieve this is to make it
-free software which everyone can redistribute and change under these terms.
-
-  To do so, attach the following notices to the program.  It is safest
-to attach them to the start of each source file to most effectively
-convey the exclusion of warranty; and each file should have at least
-the "copyright" line and a pointer to where the full notice is found.
-
-    <one line to give the program's name and a brief idea of what it does.>
-    Copyright (C) 19yy  <name of author>
-
-    This program is free software; you can redistribute it and/or modify
-    it under the terms of the GNU General Public License as published by
-    the Free Software Foundation; either version 2 of the License, or
-    (at your option) any later version.
-
-    This program is distributed in the hope that it will be useful,
-    but WITHOUT ANY WARRANTY; without even the implied warranty of
-    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-    GNU General Public License for more details.
-
-    You should have received a copy of the GNU General Public License
-    along with this program; if not, write to the Free Software
-    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
-
-
-Also add information on how to contact you by electronic and paper mail.
-
-If the program is interactive, make it output a short notice like this
-when it starts in an interactive mode:
-
-    Gnomovision version 69, Copyright (C) 19yy name of author
-    Gnomovision comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
-    This is free software, and you are welcome to redistribute it
-    under certain conditions; type `show c' for details.
-
-The hypothetical commands `show w' and `show c' should show the appropriate
-parts of the General Public License.  Of course, the commands you use may
-be called something other than `show w' and `show c'; they could even be
-mouse-clicks or menu items--whatever suits your program.
-
-You should also get your employer (if you work as a programmer) or your
-school, if any, to sign a "copyright disclaimer" for the program, if
-necessary.  Here is a sample; alter the names:
-
-  Yoyodyne, Inc., hereby disclaims all copyright interest in the program
-  `Gnomovision' (which makes passes at compilers) written by James Hacker.
-
-  <signature of Ty Coon>, 1 April 1989
-  Ty Coon, President of Vice
-
-This General Public License does not permit incorporating your program into
-proprietary programs.  If your program is a subroutine library, you may
-consider it more useful to permit linking proprietary applications with the
-library.  If this is what you want to do, use the GNU Library General
-Public License instead of this License.
+6. THIS SOFTWARE IS PROVIDED "AS IS" AND WITHOUT ANY EXPRESS OR
+   IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
+   WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+   PURPOSE.
diff --git a/COPYING.ja b/COPYING.ja
new file mode 100644
index 0000000000..230376bc60
--- /dev/null
+++ b/COPYING.ja
@@ -0,0 +1,51 @@
+本プログラムはフリーソフトウェアです．2-clause BSDL
+または以下に示す条件で本プログラムを再配布できます
+2-clause BSDLについてはBSDLファイルを参照して下さい．
+
+1. 複製は制限なく自由です．
+
+2. 以下の条件のいずれかを満たす時に本プログラムのソースを
+   自由に変更できます．
+
+   a.  ネットニューズにポストしたり，作者に変更を送付する
+       などの方法で，変更を公開する．
+
+   b.  変更した本プログラムを自分の所属する組織内部だけで
+       使う．
+
+   c.  変更点を明示したうえ，ソフトウェアの名前を変更する．
+       そのソフトウェアを配布する時には変更前の本プログラ
+       ムも同時に配布する．または変更前の本プログラムのソー
+       スの入手法を明示する．
+
+   d.  その他の変更条件を作者と合意する．
+
+3. 以下の条件のいずれかを満たす時に本プログラムをコンパイ
+   ルしたオブジェクトコードや実行形式でも配布できます．
+
+   a.  バイナリを受け取った人がソースを入手できるように，
+       ソースの入手法を明示する．
+
+   b.  機械可読なソースコードを添付する．
+
+   c.  変更を行ったバイナリは名前を変更したうえ，オリジナ
+       ルのソースコードの入手法を明示する．
+
+   d.  その他の配布条件を作者と合意する．
+
+4. 他のプログラムへの引用はいかなる目的であれ自由です．た
+   だし，本プログラムに含まれる他の作者によるコードは，そ
+   れぞれの作者の意向による制限が加えられる場合があります．
+
+   それらファイルの一覧とそれぞれの配布条件などに付いては
+   LEGALファイルを参照してください．
+
+5. 本プログラムへの入力となるスクリプトおよび，本プログラ
+   ムからの出力の権利は本プログラムの作者ではなく，それぞ
+   れの入出力を生成した人に属します．また，本プログラムに
+   組み込まれるための拡張ライブラリについても同様です．
+
+6. 本プログラムは無保証です．作者は本プログラムをサポート
+   する意志はありますが，プログラム自身のバグあるいは本プ
+   ログラムの実行などから発生するいかなる損害に対しても責
+   任を持ちません．
diff --git a/ChangeLog b/ChangeLog
deleted file mode 100644
index 4a1491bdf9..0000000000
--- a/ChangeLog
+++ /dev/null
@@ -1,3295 +0,0 @@
-Tue Feb  2 23:41:42 1999  Yoshida Masato  <yoshidam@yoshidam.net>
-
-	* regex.c (re_match): wrong boundary.
-
-	* regex.c (IS_A_LETTER): re_mbctab[c] may not be 1 for mbc.
-
-	* regex.c (re_search): mbchar support for shifting ranges.
-
-	* regex.c (MBC2WC): wrong conversion.
-
-Wed Feb  3 15:03:16 1999  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* parse.y (parse_regx): need to escape parens if terminators are
-	  not any kind of parenthesis.
-
-	* parse.y (parse_qstring): ditto.
-
-	* parse.y (parse_string): ditto.
-
-Tue Feb  2 17:11:26 1999  WATANABE Tetsuya  <tetsu@jpn.hp.com>
-
-	* string.c (rb_str_gsub_bang): too small realoc condition.
-
-Mon Feb  1 10:01:17 1999  EGUCHI Osamu  <eguchi@shizuokanet.ne.jp>
-
-	* parse.y (yylex): range check for the float literal.
-
-Sat Jan 30 18:34:16 1999  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* ruby.c (usage): -h option to show brief command description.
-
-Sat Jan 30 08:45:16 1999  IKARASHI Akira  <ikarashi@itlb.te.noda.sut.ac.jp>
-
-	* lib/cgi-lib.rb: cookie support added.
-
-Sat Jan 30 13:38:24 1999  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* regex.c (re_compile_pattern): mbchars should match with \w
-	  within character classs.  Was matching with \W.
-
-	* regex.c (re_match): \w should match with multi byte characters,
-	  not its first byte.
-
-Sat Jan 30 10:06:41 1999  Yoshida Masato  <yoshidam@yoshidam.net>
-
-	* re.c (rb_reg_s_new): UTF-8 flag handle (/u, /U).
-
-	* re.c (rb_kcode): $KCODE handle for UTF-8.
-
-Sat Jan 30 01:51:16 1999  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* array.c (rb_ary_delete_if): RTEST() missing.
-
-	* hash.c (delete_if_i): ditto.
-
-	* enum.c (Init_Enumerable): select (=find_all), detect (=find)
-	  added as aliases.
-
-Fri Jan 29 21:32:19 1999  WATANABE Tetsuya  <tetsu@jpn.hp.com>
-
-	* hash.c (rb_f_setenv): SEGV caused by small typo.
-
-Fri Jan 29 00:15:58 1999  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* lib/parsedate.rb (parsedate): support date format like
-	  23-Feb-93, which is required by HTTP/1.1.
-
-	* variable.c (find_class_path): avoid calling rb_iv_set().
-
-	* eval.c (backtrace): do not need to modify $SAFE internally.
-
-	* variable.c (classname): inline __classid__ access.
-
-	* eval.c (THREAD_ALLOC): needed to initialize wrapper.
-
-	* lib/ftools.rb (makedirs): allows slash at the end of the path.
-
-	* numeric.c (rb_fix_induced_from): ensure result to be Fixnum.
-
-Thu Jan 28 17:31:43 1999  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* numeric.c (flo_to_s): float format changed to "%16.10g".
-
-Thu Jan 28 02:13:11 1999  Yoshinori Toki  <toki@freedom.ne.jp>
-
-	* array.c (rb_ary_store): expand allocated buffer by 3/2.
-
-Wed Jan 27 17:50:02 1999  Kazuhiro HIWADA  <hiwada@kuee.kyoto-u.ac.jp>
-
-	* bignum.c (dbl2big): raised error if double is too big to cast
-	  into long.  check added.
-
-Wed Jan 27 03:16:18 1999  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* variable.c (rb_mod_const_at): can't list constants of the
-	  untainted objects in safe mode.
-
-	* class.c (method_list): can't list methods of untainted objects
-	  in safe mode.
-
-Tue Jan 26 02:40:41 1999  GOTO Kentaro  <gotoken@math.sci.hokudai.ac.jp>
-
-	* prec.c: Precision support for numbers.
-
-Thu Jan 21 19:08:14 1999  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* eval.c (rb_f_raise): calls `exception' method, not `new'.
-
-	* error.c (exc_exception): renamed from `new'.
-
-Wed Jan 20 03:39:48 1999  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* parse.y (yycompile): rb_in_compile renamed to ruby_in_compile.
-
-	* ruby.c (load_file): define DATA iff __END__ appeared in script.
-
-Tue Jan 19 14:57:51 1999  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* parse.y (here_document): need to protect lex_lastline.
-
-	* parse.y (yylex): disable %//, %'', %``.
-
-Tue Jan 19 05:01:16 1999  Koji Arai  <JCA02266@nifty.ne.jp>
-
-	* array.c (beg_len): round range value too much.
-
-Mon Jan 18 13:02:27 1999  Kuroda Jun  <jkuro@dwe.co.j>
-
-	* hash.c (env_keys): strchr() may return NULL.
-
-Mon Jan 18 17:51:47 1999  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* instruby.rb (wdir): install libruby.a in archdir.
-
-	* lib/ftools.rb (install): removes file before installing.
-
-Mon Jan 18 16:55:31 1999  MAEDA shugo  <shugo@aianet.ne.jp>
-
-	* eval.c (rb_callcc): experimental continuation support.
-
-Sun Jan 17 19:45:37 1999  WATANABE Hirofumi  <watanabe@ase.ptg.sony.co.jp>
-
-	* pack.c (pack_pack): nil packing caused SEGV.
-
-Sat Jan 16 13:18:03 1999  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* string.c (rb_str_concat): character (fixnum) can be append to
-	  strings
-
-	* array.c (rb_ary_unshift): unshift returns array.
-
-Sat Jan 16 01:39:19 1999  Yoshida Masato  <yoshidam@tau.bekkoame.ne.jp>
-
-	* string.c (rb_str_split_method): UTF-8 support.
-
-	* regex.c: UTF-8 support.
-
-Thu Jan 14 00:42:55 1999  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* string.c (rb_str_gsub_bang): forget to add offset for null match.
-
-	* eval.c (rb_thread_local_aset): can't modify in tainted mode.
-
-	* hash.c (env_each_key): avoid generating temporary array.
-
-Wed Jan 13 23:58:50 1999  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* hash.c (rb_f_setenv): name and value can be tainted.
-
-Wed Jan  6 02:42:08 1999  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* bignum.c (Init_Bignum): forgot to define Bignum#===.
-
-	* gc.c (gc_sweep): if add_heap() is called during GC, objects on
-	  allocated heap page(s) are not marked, should not be recycled.
-
-	* gc.c (gc_sweep): should refer latest freelist.
-
-	* gc.c (id2ref): modified to support performance patch.
-
-	* object.c (rb_obj_id): performance patch (no bignum for id).
-
-Tue Jan  5 01:56:18 1999  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* config.guess: merge up-to-date from autoconf 2.12.
-
-	* array.c (rb_ary_join): avoid calling rb_protect_inspect() till
-	  it is really needed.
-
-	* object.c (rb_obj_inspect): show detailed information for the
-	  instance variables (infinite loop can avoid now).
-
-	* struct.c (rb_struct_inspect): avoid infinite loop.
-
-Sun Jan  3 01:37:58 1999  Takao KAWAMURA  <kawamura@ike.tottori-u.ac.jp>
-
-	* misc/ruby-mode.el (ruby-end-of-defun): moved too much.
-
-	* misc/ruby-mode.el (ruby-mode-variables): set paragraph-separator
-	  for the mode.
-
-	* misc/ruby-mode.el: proper font-lock for `def' and `nil' etc.
-
-Sat Jan  2 17:09:06 1999  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* eval.c (rb_jump_tag): new api to invoke JUMP_TAG.  tag values
-	  can obtained from rb_eval_string_protect()/rb_load_protect().
-
-	* eval.c (rb_rescue): now catches all exceptions but SystemExit.
-
-	* eval.c (rb_eval_string_protect): eval string with protection.
-
-	* eval.c (rb_load_protect): load file with protection.
-
-	* io.c (rb_io_puts): avoid infinite loop for cyclic arrays.
-
-	* eval.c (rb_thread_local_aref): thread local hash tables.
-
-	* object.c (rb_equal): check exact equal before calling `=='.
-
-Thu Dec 31 22:28:53 1998  MAEDA shugo  <shugo@aianet.ne.jp>
-
-	* eval.c (rb_f_require): feature names should be provided with
-	  DLEXT extension.
-
-	* marshal.c (Init_marshal): need to provide `marshal.so'.
-
-Wed Dec 30 02:29:16 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* variable.c (classname): do not call rb_ivar_set().
-
-	* eval.c (ruby_run): finalizers were called too early.
-
-Fri Dec 25 12:19:30 1998  Fukuda Masaki  <fukuda@wni.co.jp>
-
-	* gc.c (rb_gc_mark): should not return on FL_EXIVAR.
-
-Fri Dec 25 11:56:51 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* gc.c (gc_mark): proper scanning for temporary region.
-
-	* eval.c (TMP_ALLOC): protection for C_ALLOCA was broken.
-
-Thu Dec 24 18:26:04 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* development version 1.3 released.
-
-Thu Dec 24 00:17:00 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* eval.c (rb_load): top self should be set properly.
-
-	* variable.c (classname): check __classpath__ iff it is defined.
-
-	* variable.c (classname): invalid warning at -v with static linked
-	  ruby interpreter.
-
-	* eval.c (is_defined): modified for expr::Const support.
-
-	* eval.c (rb_eval): invoke method expr::Const if expr is not class
-	  nor module.
-
-	* parse.y (primary): enable expr::identifier as method
-	  invocation.
-
-Wed Dec 23 03:04:36 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* regex.c (re_match): avoid too many loop pops for (?:..).
-
-Tue Dec 22 18:01:08 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* experimental version 1.1d1 released.
-
-Mon Dec 21 01:33:03 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* eval.c (TMP_PROTECT): add volatile to ensure GC protection.
-
-	* string.c (rb_str_gsub_bang): calculate buffer size properly.
-
-	* parse.y (lex_get_str): needed to return Qnil at EOS.
-
-	* eval.c (find_file): check policy modified, raise exception
-	  immediately for tainted load_path.
-
-	* hash.c (rb_f_setenv): do not depend on setenv() nor putenv().
-
-Thu Dec 17 06:29:23 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* ext/tk/tkutil.c (tk_s_new): use rb_obj_instance_eval(), instead
-	  of rb_yield_0().
-
-	* eval.c (rb_f_require): forgot to call find_file in some cases.
-
-	* eval.c (rb_f_require): `require "feature.so"' to load dynamic
-	  libraries.  old `require "feature.o"' is still OK.
-
-	* eval.c (rb_eval): yield without value dumped core.
-
-Wed Dec 16 16:28:31 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* experimental version 1.1d0 (pre1.2) released.
-
-Wed Dec 16 10:43:34 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* regex.c (re_search): bound check before calling re_match().
-
-Tue Dec 15 13:59:01 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* error.c (exc_to_s): returns class name for unset mesg.
-
-	* error.c (exc_initialize): do not initialize @mesg by "".
-
-	* parse.y (nextc): __END__ should handle CR+LF newlines.
-
-Wed Dec  9 13:37:12 1998  MAEDA shugo  <shugo@aianet.ne.jp>
-
-	* pack.c (encodes): use buffering for B-encoding.
-
-	* pack.c (pack_pack): Q-encoding by 'M'.
-
-Tue Dec  8 14:10:00 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* variable.c (generic_ivar_get): any object can have instance
-	  variables now.  great improvement.
-
-	* variable.c (rb_name_class): do not set __classpath__ by default,
-	  use __classid__ instead.
-
-Mon Dec  7 22:08:22 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* ruby.h (struct RFile): IO objects can have instance variables now.
-
-	* parse.y (primary): allows `def obj::foo; .. end'.
-
-Mon Dec  7 18:24:50 1998  WATANABE Tetsuya  <tetsu@jpn.hp.com>
-
-	* ruby.c (set_arg0): $0 supprt for HP-UX.
-
-Mon Dec  7 01:30:28 1998  WATANABE Hirofumi  <watanabe@ase.ptg.sony.co.jp>
-
-	* dln.c (dln_strerror): better error messages on win32.
-
-Sat Dec  5 23:27:23 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* parse.y (here_document): indentable here-doc delimiter by
-	  `<<-'.  Proposed by Clemens <c.hintze@gmx.net>.  Thanks.
-
-Thu Dec  3 16:50:17 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* ext/extmk.rb.in (realclean): trouble on install.
-
-Sun Nov 29 22:25:39 1998  Takaaki Tateishi  <ttate@jaist.ac.jp>
-
-	* process.c (f_exec): check number of argument.
-
-Thu Nov 26 17:27:30 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* version 1.1c9 released.
-
-Wed Nov 25 13:07:12 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* string.c (rb_str_dup): do not copy additional data (STR_NO_ORIG).
-
-	* parse.y (yycompile): reduce known memory leak (hard to remove).
-
-Wed Nov 25 03:41:21 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* st.c (st_init_table_with_size): round size up to prime number.
-
-Sat Nov 21 23:27:23 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* hash.c (rb_hash_aset): reduce copying key strings.
-
-	* gc.c (looks_pointerp): declare as inline function if possible.
-
-	* st.c (PTR_NOT_EQUAL): compare hash values first before calling
-	  comparing function.
-
-	* st.c (ADD_DIRECT): save hash value in entries to reduce hash
-	  calculation.
-
-	* string.c (rb_str_gsub_bang): avoid rb_scan_args() to speed-up.
-
-	* string.c (rb_str_sub_bang): ditto.
-
-Sat Nov 21 18:44:06 1998  Masaki Fukushima  <fukusima@goto.info.waseda.ac.jp>
-
-	* time.c (time_s_now): had memory leak.
-
-	* ext/md5/md5init.c (md5_new): had memory leak.
-
-	* ext/md5/md5init.c (md5_clone): ditto.
-
-Fri Nov 20 23:23:23 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* lib/delegate.rb: do not propagate hash and eql?.
-
-Thu Nov 19 01:40:52 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* sample/ruby-mode.el (ruby-expr-beg): failed to find reserved
-	  word boundary.
-
-	* eval.c (rb_eval): avoid calling `concat' method.  calls
-	  rb_ary_concat() directly for efficiency.
-
-	* eval.c (rb_eval): actual rest arguments extended arrays too much.
-
-Wed Nov 18 14:30:24 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* class.c (rb_define_global_function): global functions now be
-	  module function of the Kernel.
-
-Wed Nov 18 10:48:09 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* io.c (read_all): SEGV on large files.
-
-Tue Nov 17 18:11:20 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* version 1.1c8 released.
-
-Tue Nov 17 16:58:47 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* parse.y (arg): assignment to attribute name start with capital
-	  should be allowed.
-
-	* eval.c (thread_alloc): needed to mark terminated threads too.
-
-Tue Nov 17 12:33:48 1998  Motoyuki Kasahara  <m-kasahr@sra.co.jp>
-
-	* ext/extmk.rb.in (create_makefile): Set `libdir' to `@libdir@',
-	  Set `pkglibdir' to `$libdir/$(RUBY_INSTALL_NAME)'.
-
-Tue Nov 17 10:30:46 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* sprintf.c (f_sprintf): %l%%c -> %%l%c
-
-Tue Nov 17 01:08:50 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* parse.y (ret_args): distinguish `a' and `*a' for the arguments
-	  of yield and return.
-
-	* eval.c (rb_eval): flip3 should work like sed.
-
-	* eval.c (rb_eval): flip{2,3} now have independent state for each
-	  scope to work fine with thread.
-
-Mon Nov 16 23:26:29 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* parse.y (primary): exec else clause if no exception raised.
-
-Sun Nov 15 15:44:07 1998  Tadayoshi Funaba  <tadf@kt.rim.or.jp>
-
-	* ext/extmk.rb.in (install): bug in target.
-
-Sat Nov 14 11:02:05 1998  Motoyuki Kasahara  <m-kasahr@sra.co.jp>
-
-	* Makefile.in (install): Give the argument `$(DESTDIR)' to
-	`instruby.rb'.
-	* instruby.rb: Recognize ARG[0] as `destdir'.
-	* instruby.rb: Give the argument `destdir' to `extmk.rb'.
-	* ext/extmk.rb.in: Recognize ARG[1] as `$destdir'.
-
-	* instruby.rb: Create the installation directories (bindir, libdir,
-	archdir, pkglibdir, archdir, and mandir) under `destdir', and
-	install all files under there.
-	* ext/extmk.rb.in: Likewise.
-	
-Sat Nov 14 10:56:55 1998  Motoyuki Kasahara  <m-kasahr@sra.co.jp>
-
-	* instruby.rb: Add the variable `pkglibdir'.
-	* instruby.rb: Set the variable `libdir' to `$(libdir)', not
-	`$(libdir)/$(ruby_install_name)'. `libruby.so' and `libruby.so.LIB'
-	are installed at `libdir'.
-	* instruby.rb: Set the variable `archdir' to `$(pkglibdir)/$(arch)'.
-
-Fri Nov 13 19:43:29 1998  KIMURA Koichi  <kbk@kt.rim.or.jp>
-
-	* missing/nt.c (SafeFree): wrong free offset.
-
-Thu Nov 12 20:11:53 1998  Koji Arai  <JCA02266@nifty.ne.jp>
-
-	* sample/ruby-mode.el: wrong highlight.
-
-	* parse.y (parse_regx): newline in regexp was ignored.
-
-Wed Nov 11 10:54:57 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* parse.y (here_document): <<'FOO' should not escape anything.
-
-	* parse.y (here_document): bare << here-doc available, even though
-	  it's deprecated.
-
-	* file.c (rb_file_s_readlink): return value should be tainted.
-
-	* ext/etc/etc.c (setup_passwd): information (eg. GCOS name) should
-	  be tainted (modified at Perl Conference).
-
-Tue Nov 10 00:22:11 1998  EGUCHI Osamu  <eguchi@shizuokanet.ne.jp>
-
-	* configure.in: elf supprt for FreeBSD 3.x
-
-Tue Nov 10 00:05:43 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* parse.y (yylex): here document available in eval.
-
-Mon Nov  9 17:55:19 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* version 1.1c7 released.
-
-Fri Nov  6 19:25:27 1998  Takao KAWAMURA  <kawamura@ike.tottori-u.ac.jp>
-
-	* sample/ruby-mode.el: font-lock patch.
-
-Thu Nov  5 15:42:22 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* sample/README, lib/README: simple description for each file.
-
-Wed Nov  4 18:14:19 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* eval.c (assign): attribute assignment should be called as public.
-
-Tue Nov  3 23:36:39 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* string.c (rb_str_dump): dumps core for negative char value.
-
-	* regex.c (re_compile_pattern): out of boundary access for empty
-	  regexp.
-
-Mon Nov  2 22:54:01 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* string.c (rb_str_aset): `str[str]' replaces first match.
-
-Mon Nov  2 18:24:33 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* eval.c (thread_create): was accessing modified status.
-
-Sun Nov  1 01:18:52 1998  EGUCHI Osamu  <eguchi@shizuokanet.ne.jp>
-
-	* gc.c (xrealloc): size 0 needs round up to 1.
-
-Sat Oct 31 23:18:34 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* string.c (rb_str_split_method): negative LIMIT means number of
-	  splitted fields are unlimited, as in perl.
-
-	* string.c (rb_str_split_method): if LIMIT is unspecified,
-	  trailing null fields are stripped.
-
-Sat Oct 31 04:16:14 1998  Inaba Hiroto   <inaba@st.rim.or.jp>
-
-	* string.c (str_aref): regexp index SEGVed.
-
-Fri Oct 30 14:33:47 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* re.c (reg_match): returns nil for unmatch.
-
-	* dir.c (dir_entries): new method.
-
-	* eval.c (block_pass): do not push block, substitute it.
-
-Fri Oct 30 01:28:52 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* range.c (range_check): avoid <=> check for Fixnums.
-
-	* array.c (rb_ary_aset): accept negative index.
-
-Wed Oct 28 22:00:54 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* regex.c (re_match): access out of boundary fixed.
-
-Wed Oct 28 11:37:42 1998  TAMITO  <tommy@valley.ne.jp>
-
-	* io.c (f_select): fd number comparison bug.
-
-Tue Oct 27 23:07:11 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* sample/ruby-mode.el (ruby-parse-region): forgot to support %w()
-	  style array literal.
-
-	* eval.c (rb_eval): unused block raises warning.
-
-Mon Oct 26 09:37:53 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* eval.c (dvar_asgn_push): dvar pushed too many times if
-	  variable-in-block first appear in loops.
-
-Sun Oct 25 22:59:27 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* regex.c (set_list_bits): was using wrong offset.
-
-Thu Oct 22 00:07:11 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* eval.c (rb_obj_method): method retrieved from tainted object
-	  should be tainted too.
-
-	* eval.c (method_call): safe_level should be restored during
-	  Method#call.
-
-Wed Oct 21 14:21:06 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* io.c (Init_IO): new constants IO::SEEK_{SET,CUR,END}.
-
-	* io.c (rb_f_ungetc): ungetc pushes a char back into STDIN.
-
-Mon Oct 19 11:50:00 1998  Motoyuki Kasahara  <m-kasahr@sra.co.jp>
-
-	* ext/extmk.rb: Load '@top_srcdir@/lib/find.rb', not
-	'../lib/find.rb'.
-	* ext/extmk.rb: Distinguish between `top_srcdir' and `topdir'.
-	* Makefile.in (CFLAGS): Add `-I.'.
-	* Makefile.in (lex.c): Give `@srcdir@/keywords' to gperf, not
-	`keywords'.
-	* instruby.rb: Use `CONFIG["bindir"]', instead of `prefix + "/bin"'.
-	* instruby.rb: Use `CONFIG["libdir"]', instead of `prefix + "/lib"'.
-	* instruby.rb Use `CONFIG["mandir"]', instead of `prefix + "/man"'.
-	* instruby.rb (wdir): Add the variable to preserve the current
-	working directory.
-	* instruby.rb: Chdir to wdir before install `config.h' and
-	`rbconfig.rb'.
-
-Mon Oct 19 10:07:01 1998  EGUCHI Osamu  <eguchi@shizuokanet.ne.jp>
-
-	* eval.c (rb_eval): reduce recursive calls to rb_eval().
-
-Fri Oct 16 15:31:45 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* time.c (time_new_internal): timeval must be positive.
-
-Thu Oct 15 13:54:48 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* parse.y (arg): local variabls can be accessed within right side
- 	  expression in assignment, notably in blocks.
-
-Wed Oct 14 00:18:33 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* array.c (Init_Array): Array#=== is now for equal check, not
-	  inclusion check.
-
-	* parse.y (when_args): `when a, *b' style new syntax for array
-	  expansion in `case'.
-
-Tue Oct 13 14:30:32 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* object.c (rb_obj_untaint): taint marks can be unset.
-
-	* eval.c (rb_eval): taint propagation for embedded strings.
-
-Mon Oct 12 13:27:15 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* eval.c (rb_call0): check stack depth more frequently.
-
-Mon Oct 12 08:08:30 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* io.c (rb_p): can print even in secure mode.
-
-Sun Oct 11 22:50:13 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* variable.c (rb_const_set): taint check for modification.
-
-	* variable.c (rb_ivar_set): taint check for modification.
-
-	* string.c (rb_str_modify): taint check for modification.
-
-	* hash.c (rb_hash_modify): taint check for modification.
-
-	* array.c (rb_ary_modify): taint check for modification.
-
-	* ruby.h (FL_TAINT): taint for all objects, not only strings.
-
-Fri Oct  9 17:01:14 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* io.c (read_all): read() returns "" at immediate EOF.
-
-	* io.c (io_read): read(nil) read all until EOF.
-
-Thu Oct  8 13:32:13 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* time.c (time_dump): marshal can dump Time object now.
-
-	* marshal.c (Init_marshal): rename marshal methods `_dump_to' to
- 	  `_dump', `_load_from' to `_load'.
-
-	* parse.y (rb_intern): "+=".intern generates proper symbol.
-
-Mon Oct  5 18:31:53 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* version 1.1c6 released.
-
-Fri Oct  2 14:22:33 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* regex.c (re_search): `/\s*(--)$/ =~ "- --"' did not match,
-	  because of wrong optimize condition.
-
-Mon Oct  1 01:55:16 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* parse.y (rb_intern): should not raise exceptions.
-
-	* parse.y (yylex): symbol like `:foo?=' should not be allowed.
-
-	* ext/extmk.rb.in: makes *.a for static link modules.
-
-Wed Sep 30 14:13:06 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* eval.c (rb_thread_start): supports making a subclass of the
-	  Thread class.
-
-Tue Sep 29 17:46:01 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* eval.c (rb_thread_join): join is now an instance method.
-
-Fri Sep 25 12:01:19 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* parse.y (yylex): `@foo!' should be an error.
-
-Thu Sep 24 14:55:06 1998  WATANABE Tetsuya  <tetsu@jpn.hp.com>
-
-	* ext/etc/etc.c (Init_etc): wrong field definition.
-
-Thu Sep 17 17:09:05 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* io.c (io_reopen): was creating FILE* for wrong fd.
-
-Tue Sep 15 05:28:11 1998  Koji Arai  <JCA02266@nifty.ne.jp>
-
-	* regex.c (re_compile_pattern): forgot to fixup for the pattern
- 	  like (?=(A)|(B)).
-
-Tue Sep 15 01:06:08 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* io.c (rb_io_gets_internal): do not set $_ by default, only
-	  gets/readline set the variable.
-
-	* eval.c (rb_f_load): load toplevel class is set to anonymous
-	  module if safe_level >= 5, to encapsulate modification.
-
-	* eval.c (rb_f_load): set frame properly.
-
-	* string.c (rb_str_each_line): do not set $_.
-
-Mon Sep 14 14:42:27 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* regex.c (re_match): beginning and end of the string, do not
-	  automatically match `\b'.
-
-	* string.c (scan_once): comsume at leaset on character.
-
-	* regex.c (re_search): wrong behavior for negative range.
-
-Sat Sep 12 21:21:26 1998  Koji Arai  <JCA02266@nifty.ne.jp>
-
-	* regex.c (re_search): range value should be maintained.
-
-Thu Sep 10 10:55:00 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* parse.y (backref_error): yyerror does not understand formats.
-
-Tue Sep  8 18:05:33 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* version 1.1c5 released.
-
-Tue Sep  8 10:03:39 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* string.c (str_each_line): wrong line splitting with newline at
- 	  top of the string.
-
-	* string.c: non bang methods return copied string.
-
-	* eval.c (f_END): needed to initialize frame->argc;
-
-Fri Sep  4 11:27:40 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* bignum.c (bigadd): proper sign combination.
-
-	* regex.c (re_search): wrong return value for \A.
-
->>>>>>> 1.1.1.2.2.154
-Thu Sep  3 14:08:14 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* version 1.1c4 released.
-
-Tue Sep  1 10:47:16 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* regex.c (slow_search): do not compare llen and blen.  llen may
-	  be longer than blen, if little contains 0xff.
-
-	* regex.c (mbctab_euc): set 0x8e as multibyte character.
-
-	* string.c (str_inspect): mask character for octal output.
-
-Mon Aug 31 15:32:41 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* regex.c (re_search): use calculated offset if exactn is the
-	  first opcode in the compiled regexp.
-
-	* regex.c (bm_search): use Boyer-Moore search for simple search.
-
-	* regex.c (must_instr): wrong length check if pattern includes
-	  byte escape by 0xff.
-
-	* regex.c (re_compile_pattern): need not to check current_mbctype.
-
-Sat Aug 29 16:31:40 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* eval.c (rb_check_safe_str): avoid calling rb_id2name() in normal 
-	  cases to speed-up.
-
-	* eval.c (thread_raise): do not save context of terminated thread.
-
-	* regex.c (re_compile_pattern): mask \nnn over 256.
-
-Sat Aug 29 02:09:46 1998 1998  Koji Arai  <JCA02266@nifty.ne.jp>
-
-	* sprintf.c (f_sprintf): wrong buffer size check.
-
-Fri Aug 28 01:57:04 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* regex.c (re_compile_pattern): accepts (?ix-ix) and (?ix-ix:...).
-
-Fri Aug 28 12:25:33 1998  Hiroshi Igarashi  <igarashi@ueda.info.waseda.ac.jp>
-
-	* ruby.c (ruby_require_modules): load modules in appearing order.
-
-Fri Aug 28 01:57:04 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* regex.c (re_compile_pattern): accepts (?ix-ix) and (?ix-ix:...).
-
-Thu Aug 27 12:54:28 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* version 1.1c3 released.
-
-Wed Aug 26 14:40:56 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* eval.c (rb_eval): check whether ruby_class is properly set,
-	  before accessing it.
-
-	* eval.c (rb_obj_instance_eval): ruby_class should be Qnil for
-	  special objects like Fixnums.
-
-	* ext/tkutil/tkutil.c (Init_tkutil): removes calls to
-	  rb_yield_0().  used instance_eval() instead in the tk.rb.
-
-Wed Aug 26 11:47:00 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* regex.c (re_match): pop non-greedy stack elements on success.
-
-Wed Aug 26 09:25:35 1998  WATANABE Hirofumi  <watanabe@ase.ptg.sony.co.jp>
-
-	* ruby.h: add #define environ for cygwin32.
-
-Tue Aug 25 08:57:41 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* array.c (rb_ary_sort_bang): temporarily freeze sorting array.
-
-Mon Aug 24 18:46:44 1998  WATANABE Hirofumi  <watanabe@ase.ptg.sony.co.jp>
-
-	* dln.c (dln_find_1): path check was too strict.
-
-Mon Aug 24 15:28:11 1998  WATANABE Hirofumi  <watanabe@ase.ptg.sony.co.jp>
-
-	* parse.y (f_arglist): opt_nl added after f_args.
-
-Fri Aug 21 01:06:01 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* ext/socket/socket.c: grand renaming on socket.c.
-
-	* ext/socket/socket.c (inet_aton): supply inet_aton for those
-	  systems that do not have it.
-
-	* ext/socket/socket.c (setipaddr): use inet_aton instead of
-	  inet_addr.
-
-	* ext/socket/socket.c (tcp_s_gethostbyname): new method: works
-	  like Socket.gethostbyname but returning array contains ip-addrs
-	  as octet decimal string format like "127.0.0.1".
-
-	* ext/socket/socket.c (mkhostent): return format changed to
-	  [host, aliases, type, ipaddr..]  as documented.
-
-Wed Aug 19 00:31:09 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* io.c (io_ctl): forgot to place TRAP_END at right position.
-
-Fri Aug 14 11:01:47 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* eval.c (call_trace_func): save __FILE__, __LINE__ before
- 	  executing trace_func, since trace function should not corrupt
- 	  line number information.
-
-Thu Aug 13 15:09:02 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* array.c (ary_s_new): was marking unallocated region on GC.
-
-Tue Aug 11 11:57:35 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* version 1.1c2 released.
-
-Mon Aug 10 14:05:30 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* process.c (f_system): removed fflush(stdin).
-
-Fri Aug  7 17:44:44 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* error.c (err_snprintf): replace sprintf for fixed sized buffer,
- 	  with snprintf to avoid buffer over-run.  For systems which does
-	  dot provide snprintf, missing/snprintf.c added.
-
-Wed Aug  5 00:47:35 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* re.c (rb_reg_search): recycle match object.
-
-Mon Aug  3 09:17:55 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* string.c (rb_str_gsub_bang): do not allocate temporary string.
-
-	* string.c (rb_str_sub_bang): use inline replace.
-
-Wed Jul 29 00:36:08 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* hash.c (hash_s_new): the default value can be specified.
-
-	* hash.c (hash_default): method to set the default value.
-
-	* hash.c (hash_aref): now returns the default value.
-
-Tue Jul 28 13:03:25 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* array.c (ary_s_new): argument to specify initial value is added.
-
-	* array.c (ary_s_new): specifies size, not capacity.
-
-Mon Jul 27 12:39:34 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* string.c (str_replace): zero fill for expansion gap.
-
-	* regex.c (mbctab_euc): set flags on for 0xA1-0xFE.  suggested by
-	  <inaba@st.rim.or.jp>.
-
-	* string.c (str_inspect): consider current_mbctype.
-
-Sun Jul 26 15:37:11 1998  Tadayoshi Funaba  <tadf@kt.rim.or.jp>
-
-	* array.c (ary_s_new): Array.new(1<<30) dumps core.
-
-Fri Jul 24 13:40:19 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* version 1.1c1 released.
-
-Fri Jul 24 02:10:22 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* marshal.c (r_bytes2): allocated buffer size was too short.
-
-	* marshal.c (w_object): saves all options, not only casefold flag.
-
-	* re.c (reg_clone): now copies options properly.
-
-	* re.c (reg_get_kcode): code number was wrong.
-
-Thu Jul 23 13:11:32 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* eval.c (rb_attr): argument should be symbol or string.
-
-Wed Jul 22 11:59:34 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* regex.c (calculate_must_string): wrong offset added.
-
-Wed Jul 22 11:59:59 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* st.c (rehash): still had a GC problem.  fixed.
-
-Tue Jul 21 13:19:30 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* eval.c (gc_mark_threads): crashed on GC before thread allocation.
-
-	* st.c (rehash): GC during rehash caused SEGV.
-
-Tue Jul 21 01:25:10 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* sprintf.c (f_sprintf): integer formatter totally re-written.
-
-	* sprintf.c (remove_sign_bits): support uppercase hexadecimal.
-
-Sat Jul 18 00:14:13 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* sprintf.c (f_sprintf): proper sign position for %X and %O.
-
-Fri Jul 17 14:10:20 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* version 1.1c0 released.
-
-Fri Jul 17 08:01:49 1998  Tadayoshi Funaba  <tadf@kt.rim.or.jp>
-
-	* process.c (f_exec): Check_SafeStr() added.
-
-	* process.c (f_system): Check_SafeStr() moved before fork().
-
-Thu Jul 16 22:58:48 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* string.c (scan_once): substrings to the block should not be
- 	  tainted.  use reg_nth_match(), not str_substr().
-
-	* string.c (str_substr): needed to transfer taint.
-
-Thu Jul 16 16:15:57 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* gc.c (xmalloc): object allocation count added to GC trigger.
-
-	* eval.c (thread_save_context): avoid marking uninitialized stack
-	  in thread_mark.  GC may be triggered by REALLOC_N().
-
-Wed Jul 15 15:11:57 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* experimental release 1.1b9_31.
-
-Wed Jul 15 15:05:27 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* eval.c (thread_create): exit() and abort() in threads now
- 	  forwarded to main_thread.
-
-Tue Jul 14 14:03:47 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* variable.c (obj_instance_variables): list names that is not
-	  instance variables.
-
-	* gc.c (GC_MALLOC_LIMIT): choose smaller limit value.
-
-Mon Jul 13 12:39:38 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* object.c (str2cstr): should not return NULL.
-
-Fri Jul 10 11:51:46 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* parse.y (gettable): needed to add dyna_in_block() check.
-
-Thu Jul  9 17:38:23 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* experimental release 1.1b9_30.
-
-Thu Jul  9 16:01:48 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* sprintf.c (fmt_setup): format specifier for long needed.
-
-	* sprintf.c (f_sprintf): ditto.
-
-	* numeric.c (fix2str): ditto.
-
-	* eval.c (thread_create): no more ITIMER_REAL.
-
-	* eval.c (thread_create): thread finalization needed before
-	  aborting thread if thread_abort is set.
-
-Wed Jul  8 18:17:33 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* bignum.c (big_pow): abandon power by bignum (too big).
-
-Tue Jul  7 13:58:43 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* eval.c (rb_catch): add C level catch/throw feature.
-
-Mon Jul  6 15:18:09 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* parse.y (arg): proper return values for `||=' and `&&='.
-
-Fri Jul  3 16:05:11 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* experimental release 1.1b9_29.
-
-Fri Jul  3 11:20:46 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* marshal.c (r_byte): byte should not extend sign bit.
-
-	* numeric.c (fix_mul): use FIX2LONG() instead of FIX2INT() for
-	  64bit architectures.
-
-	* marshal.c (r_bytes): remove weird casting bwetween pointer and int.
-
-	* process.c (proc_setsid): new method Process#setsid().
-
-Thu Jul  2 12:49:21 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* marshal.c (w_object): remove `write_bignum' label for 64bit
- 	  architectures.
-
-	* marshal.c (r_bytes): needs int, not long.
-
-Wed Jul  1 14:21:06 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* numeric.c (flo_plus): should not allow addition with strings.
-
-Wed Jul  1 13:09:01 1998  Keiju ISHITSUKA  <keiju@rational.com>
-
-	* numeric.c (num_uminus): wrong coerce direction.
-
-Tue Jun 30 10:13:44 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* io.c (f_p): accepts arbitrary number of arguments.
-
-	* eval.c (rb_yield_0): there's some case that iterator_p() returns 
-	  true even if the_block was not set.  check added.
-
-Tue Jun 30 01:05:20 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* eval.c (BEGIN_CALLARGS): adjust the_block before evaluating the
-	  receiver's value and the arguments.
-
-Fri Jun 26 18:02:50 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* experimental release 1.1b9_28.
-
-Fri Jun 26 11:01:26 1998  WATANABE Hirofumi  <watanabe@ase.ptg.sony.co.jp>
-
-	* string.c (str_aset_method): needed to convert to string.
-
-Thu Jun 25 02:05:50 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* regex.c (re_search): optimize for `.*' at beginning of the
-	  pattern.
-
-	* regex.c (re_search): optimize for character class repeat at
-	  beginning of the pattern.
-
-	* regex.c (re_compile_pattern): detect optimization potential for
-	  the compiled patterns.
-
-Thu Jun 25 00:02:26 1998  WATANABE Hirofumi  <watanabe@ase.ptg.sony.co.jp>
-
-	* re.c (reg_s_new): flag value was wrong.
-
-Wed Jun 24 23:45:06 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* regex.c (re_search): wrong anchor handling for reverse search.
-
-Wed Jun 24 02:18:57 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* parse.y (mlhs): `((a,b)),c = [[1,2]],3' assigns a=1,b=2,c=3.
-
-Tue Jun 23 11:46:16 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* parse.y (yylex): `&&=' and `||=' added.
-
-Sat Jun 20 02:53:50 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* parse.y (assignable): nesting local variables should have higher
- 	  priority than normal local variables for assignment too.
-
-Fri Jun 19 18:28:19 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* experimental release 1.1b9_27.
-
-Fri Jun 19 14:34:49 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* eval.c (assign): support hack for nested multiple assignment.
-
-	* parse.y (mlhs): nested multiple assignment.
-
-	* eval.c (rb_eval): in-block variables now honors static scope.
-
-	* configure.in: RSHIFT check moved to configure.
-
-Thu Jun 18 16:46:04 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* experimental release 1.1b9_26.
-
-Thu Jun 18 13:37:19 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* file.c (file_s_ftype): uses lstat(2) instead of stat(2).
-
-	* dir.c (dir_s_glob): there can be buffer overrun, check added.
-
-	* eval.c (f_binding): handles in-block variables declared after
-	  binding's generation.
-
-	* numeric.c (flo_floor): floor, ceil, round added to Float.
-
-Wed Jun 17 11:20:00 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* parse.y (gettable): nesting local variables should have higher
- 	  priority than normal local variables.
-
-Tue Jun 16 12:30:46 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* bignum.c (str2inum): handles `+ddd'.
-
-	* struct.c (make_struct): name parameter can be nil for unnamed
-	  structures.
-
-Mon Jun 15 16:30:10 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* object.c (class_s_inherited): prohibiting to make subclass of
-	  class Class.
-
-	* object.c (module_s_new): support for making subclass of Module.
-
-	* parse.y (yycompile): clear eval_tree before compiling.
-
-Fri Jun 12 17:58:18 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* eval.c (eval): write back the_dyna_var into the block.
-
-Thu Jun 11 18:19:18 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* experimental release 1.1b9_25.
-
-	* eval.c (dvar_add_compiling): register dyna_var at compile time.
-
-	* regex.c (re_compile_pattern): RE_DUP_MAX iteration is too big.
-
-Wed Jun 10 15:12:04 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* io.c (io_eof): do not block other threads.
-
-	* signal.c (trap): reserve SIGALRM for thread.
-
-	* eval.c (thread_create): use ITIMER_REAL also to avoid system
-	  call blocking.
-
-	* io.c (f_syscall): add TRAP_BEG, TRAP_END around system calls.
-
-	* io.c (io_ctl): add TRAP_BEG, TRAP_END around system calls.
-
-	* enum.c (enum_collect): did not collect false values.
-
-	* array.c (ary_new2): forgot to initialize capa field.
-
-Tue Jun  9 18:36:15 1998  WATANABE Hirofumi  <watanabe@ase.ptg.sony.co.jp>
-
-	* string.c (str_split_method): split dumped core for "\xff".
-
-Tue Jun  9 16:22:12 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* experimental release 1.1b9_24.
-
-Tue Jun  9 16:04:07 1998  WATANABE Hirofumi  <watanabe@ase.ptg.sony.co.jp>
-
-	* ext/kconv/kconv.c (kconv_guess): more precise decision for EUC,
-	  using jless algorithm (3 sequential EUC hiragana characters).
-
-Tue Jun  9 15:12:44 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* ext/kconv/kconv.c (kconv_guess): wrong guess for EUC as SJIS in
-	  some cases (0xe0 - 0xef).
-
-	* gc.c (xmalloc): insert size check for big (negative in signed)
-	  allocation size.
-
-Tue Jun  9 02:54:51 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* lib/parsedate.rb: wday moved to the last in the return values.
-
-Mon Jun  8 10:40:16 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* string.c (str_split_method): split dumped core for "\0".
-
-Sat Jun  6 22:50:52 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* regex.c (calculate_must_string): wrong condition for
-	  {start,stop}_nowidth.
-
-	* regex.c (re_match): various features imported from GNU regex.c
- 	  0.12, such as nested grouping, avoiding infinite loop with empty
- 	  match, etc.
-
-	* regex.c (register_info_type): now use union.
-
-	* regex.c (re_search): more precise anchor(^) check.
-
-Wed Jun  3 18:07:54 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* re.c (reg_raise): check rb_in_compile, not rb_in_eval.
-
-Mon Jun  1 05:26:06 1998  WATANABE Tetsuya  <tetsu@jpn.hp.com>
-
-	* string.c (trnext): casting to signed char* needed.
-
-Tue Jun  2 16:00:12 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* ext/socket/socket.c (udp_addrsetup): error check enhanced.
-
-	* ext/socket/socket.c (sock_s_getservbyaname): use strtoul(), if
-	  possible.
-
-Sat May 30 07:10:02 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* re.c (reg_prepare_re): no more needless regular expression
- 	  recompile on casefold conditions.
-
-Thu May 28 18:02:55 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* object.c (nil_plus): no more `+' method for nil.
-
-Wed May 27 17:33:46 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* hash.c (hash_fetch): new method.
-
-	* regex.c (re_search): check whether translate table is set.
-
-Tue May 26 11:39:50 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* experimental release 1.1b9_23.
-
-	* parse.y (yylex): no UPLUS/UMINUS for 1st argument if
-	  parenthesises are omitted.
-
-Tue May 26 01:09:55 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* regex.c (re_compile_pattern): (?XI) for turns off the
-	  corresponding option.
-
-Mon May 25 12:38:56 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* regex.c (re_compile_pattern): inline i option (?i).
-
-	* regex.c (re_compile_pattern): inline x option (?x).
-
-	* regex.c (re_compile_pattern): x option for regexp.
-
-	* dir.c (dir_s_open): returns block's evaluated value.
-
-	* io.c (f_open): returns block's evaluated value.
-
-	* ext/curses/curses.c (curses_addstr): nil argument caused SEGV.
-
-Fri May 22 11:52:45 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* regex.c (re_compile_pattern): push mark on (?:), so that
-	  laststart check for {a,b} can be done.
-
-Thu May 21 17:31:16 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* regex.c (re_match): wrong match (too non-greedy) for `{a,b}?'.
-
-	* io.c (io_lineno): new method IO#lineno, IO#lineno=.
-
-Wed May 20 06:04:43 1998  MAEDA shugo  <shugo@aianet.ne.jp>
-
-	* BeOS patch.
-
-Wed May 20 16:32:19 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* bignum.c (BIGDN): use RSHIFT(), instead of mere `>>'.
-
-Tue May 19 16:36:26 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* experimental release 1.1b9_22.
-
-Tue May 19 16:31:57 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* parse.y (assignable): specification changed for in-block
- 	  variable definition.
-
-	* eval.c (dyna_var_asgn): error in in-block variables' compile
- 	  time definition.
-
-	* parse.y (str_extend): wrong nesting detection.
-
-Tue May 19 09:47:55 1998  WATANABE Hirofumi  <watanabe@ase.ptg.sony.co.jp>
-
-	* numeric.c (num2int): re-defined (extensions may use this).
-
-Mon May 18 16:40:50 1998  MAEDA shugo  <shugo@aianet.ne.jp>
-
-	* error.c (get_syserr): BeOS support.
-
-	* configure.in: modified for BeOS.
-
-	* string.c (str_dump): do not call isascii().
-
-	* sprintf.c (remove_sign_bits): forgot to initialize end pointer.
-
-	* glob.c: #include <alloca.h> added.
-
-Mon May 18 14:52:21 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-	
-	* experimental release 1.1b9_21.
-
-Mon May 18 03:27:57 1998  MAEDA shugo  <shugo@aianet.ne.jp>
-
-	* file.c (file_s_expand_path): optional second argument
-	  `default_directory' added.
-
-Sat May 16 22:06:52 1998  WATANABE Hirofumi  <watanabe@ase.ptg.sony.co.jp>
-
-	* error.c (RAISE_ERROR): wrong error message
-
-Fri May 15 14:43:25 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* experimental release 1.1b9_20.
-
-Thu May 14 14:44:21 1998  WATANABE Hirofumi  <watanabe@ase.ptg.sony.co.jp>
-
-	* sun4 cc patches for intern.h and regex.h.
-
-Thu May 14 14:03:16 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* random.c (RANDOM_MAX): guessing proper maximum value for random
- 	  numbers.
-
-	* random.c (f_rand): use drand48 if possible.
-
-Wed May 13 19:05:20 1998 1998  MAEDA shugo  <shugo@aianet.ne.jp>
-
-	* BeOS patches for io.c, error.c and config.guess.
-
-Wed May 13 14:56:23 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* experimental release 1.1b9_19.
-
-	* most of the Mac and BeOS patches merged, except path separators.
-
-	* error.c (err_append): generated SyntaxError was String.
-
-	* ruby.h: xxx2INT, xxx2UINT checks values as int, not long.
-
-	* ruby.h: remove typedef's. INT, UINT, UCHAR, USHORT.
-
-Tue May 12 17:38:00 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* experimental release 1.1b9_18.
-
-Tue May 12 11:38:08 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* error.c (syserr_errno): returns errno of the SystemCallError.
-
-	* error.c (rb_sys_fail): saves errno in the Exception.
-
-	* error.c (set_syserr): no need to protect syserr_list.
-
-	* error.c (rb_sys_fail): no more bufsize limit.
-
-	* error.c (set_syserr): integer value of errno can be accessed by
-	  Errno::EXXX::Errno.
-
-Sun May 10 03:10:33 1998  WATANABE Tetsuya  <tetsu@jpn.hp.com>
-
-	* io.c (io_tell etc.): moved from File class to IO class.
-
-Fri May  8 12:26:37 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* pack.c (pack_unpack): should be unsigned int (was signed int).
-
-Thu May  7 16:34:10 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* pack.c (pack_pack): `V', `N' uses newly created NUM2UINT().
-
-	* ruby.h (NUM2UINT): new macro.
-
-	* bignum.c (big2uint): try to convert bignum into UINT.
-
-	* re.c (reg_match): needed to return false for match with nil.
-
-	* gc.c (obj_free): wrong condition to free string.
-
-Wed May  6 21:08:08 1998  WATANABE Hirofumi  <watanabe@ase.ptg.sony.co.jp>
-
-	* ruby.c (ruby_process_options): modified for DJGPP.
-
-Wed May  6 15:48:03 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* experimental release 1.1b9_17.
-
-Wed May  6 01:37:39 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* eval.c: remove global variable `errat'.
-
-	* eval.c (rb_longjmp): embed error position information in the
- 	  exception object.
-
-Sat May  2 12:20:02 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* re.c (reg_search): supports reverse search.
-
-	* string.c (str_index_method): does update $~ etc.
-
-	* eval.c (f_load): needed to clear the_dyna_vars.
-
-	* eval.c (dyna_var_asgn): do not push dyna_var, which is id == 0.
-
-	* error.c (Init_Exception): NotImplementError is no longer
-	  StandardError, which is not handled by default rescue.
-
-Fri May  1 00:35:51 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* ruby.c (proc_options): `-d' turns on verbose flag too.
-
-	* error.c (exception): last argument may be the superclass of the
-	  defining exception(s).
-
-	* io.c (Init_IO): EOFError is now subclass of the IOError.
-
-	* io.c (Init_IO): forgot to define IOError.
-
-	* error.c (Init_Exception): old Exception class renamed to
-	  StandardError.  Exception now replaces old GlobalExit.
-
-	* error.c (Init_Exception): Exception is now the root of the
-	  Global Exits.  There's no longer GlobalExit class.
-
-	* util.c (ruby_mktemp): check TMP, TMPDIR first.
-
-Thu Apr 30 01:08:35 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* lib/tk.rb: call 'unknown', if proc not defined.
-
-	* eval.c (handle_rescue): default rescue handles `Exceptional' not 
-	  only the instance of the `Exception's.
-
-	* eval.c (f_raise): exception can be any object.
-
-	* time.c (time_gm_or_local): call time_gmtime or time_localtime.
-
-	* eval.c (f_raise): raises TypeError if the class which is not a
-	  subclass of String is specified (checked in exc_new()).
-
-	* error.c (exc_new): need to check whether invalid class (not a
-	  subclass of String) is specified.
-
-Wed Apr 29 21:05:44 1998  WATANABE Hirofumi  <eban@os.rim.or.jp>
-
-	* ruby.c (proc_options): option '-e' via tempfile.
-
-Tue Apr 28 15:27:58 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* experimental release 1.1b9_16.
-
-Tue Apr 28 00:07:38 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* eval.c (obj_is_proc): type check predicate.
-
-	* eval.c (obj_is_block): ditto.
-
-Mon Apr 27 16:59:17 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* ext/gtk/gtk.c (Init_gtk): use timeout, not idle to avoid
-	  comsuming CPU too much.
-
-	* lib/tk.rb: use tcltklib#_invoke instead of `_eval'.
-
-Mon Apr 27 16:59:17 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* array.c (ary_sort): use dup, not clone.
-
-Mon Apr 27 13:46:27 1998  Tadahiro Maebashi  <maebashi@iij.ad.jp>
-
-	* ext/tcltklib/tcltklib.c (ip_invoke): invoke tcl command
-	  directly.  need not worry about escaping tcl characters.
-
-Mon Apr 27 12:04:43 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* random.c (f_rand): do not call srand() implicitly.
-
-Fri Apr 24 14:35:45 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* experimental release 1.1b9_15.
-
-	* parse.y (assignable): dyna_var_asgn actually defines nested
-	  local variables in outer context.
-
-	* random.c (f_rand): call srand(), if it has not called yet.
-
-	* random.c (f_srand): use tv_usec as the default seed.
-
-	* eval.c (rb_eval): values of nested local variables should be
- 	  independent.
-
-	* eval.c (rb_yield_0): local variables wrong nested conditions.
-
-Wed Apr 22 23:27:17 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* io.c (select_get_io): get IO object by `to_io'.
-
-	* io.c (io_to_io): method to retrieve IO object, from delegating
- 	  object for example.
-
-Wed Apr 22 16:52:37 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* experimental release 1.1b9_14.
-
-	* string.c (str_modify): check for embedded pointer reference.
-
-	* gc.c (obj_free): ditto.
-
-	* pack.c (pack_pack): p/P template to embed pointers.
-
-Wed Apr 22 00:07:10 1998  Tadayoshi Funaba  <tadf@kt.rim.or.jp>
-
-	* array.c (ary_rindex): embarrassing typo.
-
-Tue Apr 21 12:31:48 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* experimental release 1.1b9_13.
-
-	* configure.in (RUBY_LIB): supports --program-{prefix,suffix}.
-
-	* array.c (ary_rindex): new method.
-
-	* io.c (io_binmode): should return self.
-
-Tue Apr 21 08:23:04 1998  Tadayoshi Funaba  <tadf@kt.rim.or.jp>
-
-	* parse.y (here_document): calling parse_string with wrong
-	  arguments.
-
-	* struct.c (struct_aset): problem member assignment with name.
-
-Mon Apr 20 14:47:49 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* experimental release 1.1b9_12.
-
-	* time.c (time_arg): args may be string (support for reduced
-	  implicit type conversion).
-
-	* lib/base64.rb: changed to use pack/unpack with `m' template.
-
-Mon Apr 20 06:23:20 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* variable.c (mod_remove_const): new method.
-
-Sat Apr 18 03:53:27 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* hash.c (hash_each_with_index): removed.  use Enumerable's
-	  each_with_index instead.
-
-	* class.c (rb_include_module): check for super modules, since
- 	  module's included modules may be changed.
-
-Fri Apr 17 21:50:47 1998  WATANABE Hirofumi  <watanabe@ase.ptg.sony.co.jp>
-
-	* marshal.c (r_long): r_byte() may return signed byte.
-
-Fri Apr 17 11:58:30 1998  NAGAI Hidetoshi  <nagai@dumbo.ai.kyutech.ac.jp>
-
-	* ext/tcltklib/tcltklib.c (lib_mainloop): thread and interrupt check.
-
-Fri Apr 17 11:06:30 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* eval.c (find_file): try to fopen() to check whether file exists.
-
-	* ruby.c (load_file): ditto.
-
-	* struct.c (struct_aset): struct member can be set by member name.
-
-Fri Apr 17 00:47:19 1998  WATANABE Hirofumi  <watanabe@ase.ptg.sony.co.jp>
-
-	* ext/extmk.rb.in: added m68k-human support
-
-	* file.c (LOCK_SH): defines moved.
-
-	* array.c (ary_flatten_bang): simplified loop.
-
-Thu Apr 16 16:52:01 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* experimental release 1.1b9_11.
-
-	* lib/tk.rb: thread support (experimental - maybe slow).
-
-	* eval.c (rb_longjmp): trace event on exception in raising
- 	  context, just before raising exception.
-
-	* struct.c (struct_s_members): forgot to check singletons.
-
-	* struct.c (struct_aref): members can be accessed by names too.
-
-	* array.c (ary_flatten): new method.
-
-	* eval.c (rb_longjmp): prints exception information with `-d'.
-
-	* object.c (any_to_s): remove class name restriction.
-
-Thu Apr 16 01:38:02 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* file.c (thread_flock): do not block other threads.
-
-	* eval.c (thread_trap_eval): signals are now delivered to the
- 	  current thread again.  In case that the current thread is dead,
- 	  signals are forwarded to the main thread.
-
-	* string.c (str_new4): need not to duplicate frozen strings.
-
-Wed Apr 15 08:33:47 1998  Tadayoshi Funaba  <tadf@kt.rim.or.jp>
-
-	* struct.c (struct_inspect): remove restriction for struct names.
-
-Wed Apr 15 02:55:02 1998  Kazuya 'Sharl' Masuda  <sharl@www.ufo.co.jp>
-
-	* x68 patches to config.sub, ext/extmk.rb.in
-
-Wed Apr 15 01:22:56 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* string.c (str_dup_frozen): do not duplicate frozen strings.
-
-	* parse.y (yylex): allow nested parenthesises.
-
-	* io.c (obj_displayln): prints newline after `display'ing the
-	  receiver.
-
-	* io.c (io_puts): avoid generating "\n" each time.  use RS_default
- 	  instead.
-
-	* io.c (f_p): ditto.
-
-Tue Apr 14 22:18:17 1998  Tadayoshi Funaba  <tadf@kt.rim.or.jp>
-
-	* struct.c (struct_aref): should not subtract negative index.
-
-Tue Apr 14 11:34:50 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* experimental release 1.1b9_10.
-
-	* parse.y: token names prefixed by `t'.
-
-	* struct.c (struct_s_def): supports subclassing of Struct.
-
-	* io.c (io_s_new): supports subclassing of IO.
-
-Mon Apr 13 11:07:39 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* eval.c (f_binding): need to restore method name.
-
-	* eval.c (rb_call0): raises SystemStackError, not Fatal.
-
-	* io.c (obj_display): same as `print self'.
-
-	* io.c (f_p): can now be called in the method form.
-
-	* re.c (reg_regsub): needed to be mbchar aware.
-
-Mon Apr 13 13:18:32 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* eval.c (thread_trap_eval): all signals delivered to main_thread.
-
-Mon Apr 13 12:47:03 1998  TAKAHASHI Masayoshi  <maki@inac.co.jp>
-
-	* re.c (kcode_set_option): did not set SJIS on SJIS condition.
-
-Sun Apr 12 22:14:07 1998  Kazunori NISHI  <kazunori@swlab.csce.kyushu-u.ac.jp>
-
-	* array.c (ary_uniq_bang): should be `==', not `='. embarrassing.
-
-Sat Apr 11 02:13:30 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* array.c (ary_subseq): SEGVed for `[][1,1]'.
-
-Fri Apr 10 21:29:06 1998  Tadayoshi Funaba  <tadf@kt.rim.or.jp>
-
-	* array.c (ary_subseq): add check for beg larger than array length.
-
-Wed Apr  8 17:24:11 1998  MAEDA shugo  <shugo@po.aianet.ne.jp>
-
-	* dir.c (dir_s_open): can be called with block (like IO#open).
-
-	* dir.c (dir_s_chdir): print directory path on error.
-
-	* dir.c (dir_s_chroot): ditto
-
-	* dir.c (Init_Dir): needed to override `new'.
-
-Thu Apr  9 18:24:58 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* experimental release 1.1b9_09.
-
-	* string.c (str_cmp): do not depend on sentinel at the end of the
-	  strings. 
-
-	* string.c (str_chomp_bang): forgot to set the sentinel.
-
-Wed Apr  8 00:59:13 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* bignum.c (big2int): converted int may be too big to fit in
-	  signed int.
-
-	* parse.y (arg): `foo += 1' should not cause an error.
-
-	* variable.c (rb_const_defined): returned false even if the
-	  constant is defined at the top level.
-
-	* eval.c (f_local_variables): dyna_var->id may be null.  should
-	  have checked before calling str_new2().
-
-Tue Apr  7 01:15:15 1998  Kaneko Naoshi  <wbs01621@mail.wbs.or.jp>
-
-	* re.c (reg_regsub): need to check string boundary.
-
-Tue Apr  7 19:19:12 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* string.c (str_cmp): returns either 1, 0, -1.
-
-	* array.c (ary_cmp): should check array length, too
-
-Tue Apr  7 18:50:16 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* experimental release 1.1b9_08.
-
-Tue Apr  7 18:31:27 1998  WATANABE Hirofumi  <watanabe@ase.ptg.sony.co.jp>
-
-	* instruby.rb (mandir): dll installation for cygwin32
-
-Tue Apr  7 01:16:45 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* config.sub (maybe_os): TOWNS support?
-
-	* config.guess: too strict check for libc versions on linuxes.
-
-	* experimental release 1.1b9_07.
-
-	* array.c (ary_cmp): compare each element using `<=>'.
-
-	* hash.c (hash_each_with_index): yields [value, key] pair.
-
-	* class.c (class_protected_instance_methods): list protected
-	  method names.
-
-	* class.c (ins_methods_i): exclude protected methods.
-
-	* eval.c (PUSH_BLOCK): dynamic variables can be accessed from
- 	  eval() with bindings.
-
-Mon Apr  6 14:49:06 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* eval.c (thread_yield): must return evaluated value.
-
-Fri Apr  3 13:07:29 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* eval.c (thread_schedule): context switch bypassed on wrong
-	  conditions.
-
-	* variable.c (rb_name_class): set classname by id before String
- 	  class is initialized (1.0 behavior restored).
-
-Fri Apr  3 11:25:45 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* numeric.c (num2int): no implicit conversion from string.
-
-	* numeric.c (num2int): check whether `to_i' returns an Integer.
-
-	* numeric.c (num_zero_p): new method.
-
-	* numeric.c (num_nonzero_p): new method.  returns the receiver if
- 	  it's not zero.
-
-	* eval.c (obj_instance_eval): the_class should be the object's
-	  singleton class.
-
-	* error.c (exc_s_new): message is converted into a string.
-
-Thu Apr  2 18:31:46 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* eval.c (obj_call_init): every object call `initialize'.
-
-Wed Apr  1 08:51:53 1998  Tadayoshi Funaba  <tadf@kt.rim.or.jp>
-
-	* parse.y (stmt): UNTIL_MOD should be for stmt, not only for expr.
-
-Wed Apr  1 01:20:31 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* object.c (true_and): boolean operators &, | and ^.
-
-Tue Mar 31 13:23:58 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* array.c (ary_compact_bang): returns nil, if it does not modify
-	  the array like String's bang methods.
-
-	* array.c (ary_uniq_bang): new method to remove duplicate items.
-
-	* eval.c (bind_s_new): new method.
-
-	* numeric.c (num2int): raise exception if Fixnums too big to
- 	  convert into `int' in case that sizeof(int) < sizeof(INT).
-
-	* string.c (str_center): SEGV on negative width.
-
-	* eval.c (eval): forgot to set sourcefile.
-
-Mon Mar 30 11:12:29 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* file.c (f_test): raises exception for unkown command.
-
-	* eval.c (Init_eval): `class_eval': alias to the module_eval.
-
-Mon Mar 30 18:50:42 1998  Tadayoshi Funaba  <tadf@kt.rim.or.jp>
-
-	* string.c (str_capitalize_bang): did not check string modification.
-
-	* string.c (str_delete_bang): wrong conversion.
-
-	* string.c (str_intern): typo in error message.
-
-Mon Mar 30 01:44:13 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* eval.c (obj_instance_eval): accepts block as evaluation body.
-	  No compilation needed each time.
-
-	* eval.c (mod_module_eval): ditto
-
-	* file.c (file_s_umask): umask did not return old values, if no
- 	  argument given.
-
-Sun Mar 29 00:54:23 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* eval.c (f_throw): nil returned always.
-
-Sat Mar 28 20:40:12 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* experimental release 1.1b9_06.
-
-Sat Mar 28 16:07:11 1998  WATANABE Hirofumi  <watanabe@ase.ptg.sony.co.jp>
-
-	* io.c (io_closed): should not cause exception fot closed IO.
-
-	* string.c (str_tr): returned nil for success.
-
-Sat Mar 28 00:47:19 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* eval.c (f_local_variables): new method to return an array of
- 	  local variable names.
-
-	* variable.c (obj_instance_variables): now returns an array of
-	  variable names, as described in the reference.
-
-	* eval.c (rb_attr): honors default method visibility of the
-	  current scope.
-
-Fri Mar 27 13:49:27 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* experimental release 1.1b9_05.
-
-	* ruby.c (ruby_prog_init): `site_ruby' added to load_path.
-
-	* ruby.c (ruby_prog_init): load-path order changed.  Paths in
- 	  the RUBYLIB environment variable comes first in non-tainted
- 	  mode.
-
-Thu Mar 26 11:51:09 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* eval.c (rb_call): new feature: `protected' methods.
-
-	* string.c (str_dump): new method.
-
-	* eval.c (block_pass): block argument can be nil, which means no
-	  block is supplied for the method.
-
-Wed Mar 25 21:20:13 1998  Tadayoshi Funaba  <tadf@kt.rim.or.jp>
-
-	* string.c (str_reverse_bang): string copied to wrong place.
-
-Wed Mar 25 08:12:07 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* numeric.c (flo_modulo): caused SEGV if left operand is not a
- 	  float value.
-
-	* eval.c (f_eval): optional third and fourth argument to specify
-	  file-name and line-number.
-
-	* eval.c (eval): file-name and line-number set properly.
-
-	* parse.y (assign_in_cond): literal assignment is now warning, not 
-	  compile error.
-
-	* error.c (Warn): Warn() always print message, OTOH Waring()
-	  prints when verbose flag is set.
-
-Tue Mar 24 12:50:06 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* ruby.c (ruby_prog_init): `.' should come last in the load-path.
-
-	* eval.c (Init_eval): `__send__', alias for `send'.
-
-Mon Mar 23 12:44:12 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* string.c (str_chomp_bang): now takes `rs' as an argument.
-
-	* eval.c (thread_free): main_thread should not be freed.
-
-Fri Mar 20 16:40:34 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* string.c (str_chomp_bang): chomp! (and other ! methods) returns
- 	  nil if it does not modify the string.
-
-	* string.c (str_sub_iter_s): should check last pattern since it
- 	  may be matched to null.
-
-Thu Mar 19 13:48:55 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* experimental release 1.1b9_04.
-
-	* parse.y (yylex): `10e0.9' should cause syntax error.
-
-Wed Mar 18 17:46:31 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* ruby.c (load_file): new file object constant DATA.  Only
-	  available for the script from the file.
-
-	* regex.c (re_match): forwading failure point popped too much. 
-
-Tue Mar 17 18:23:06 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* math.c (math_frexp): newly added.
-
-	* math.c (math_ldexp): ditto.
-
-	* bignum.c (bigdivmod): calculates modulo.
-
-	* numeric.c (fix_remainder): returns reminder, formerly introduced
- 	  as modulo.
-
-	* numeric.c (fix_modulo): calculates proper `modulo'.
-
-	* bignum.c (bigdivmod): wrong sign for reminder.
-
-Mon Mar 16 17:07:28 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* experimental release 1.1b9_03.
-
-Mon Mar 16 16:33:53 1998  WATANABE Hirofumi  <watanabe@ase.ptg.sony.co.jp>
-
-	* io.c (pipe_finalize): needed to add pipe_finalize to pipes on
-	  cygwin32.
-
-Mon Mar 16 14:11:06 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* class.c (ins_methods_i): needed to consider NOEX_UNDEF.
-
-Mon Mar 16 13:23:53 1998  WATANABE Hirofumi  <watanabe@ase.ptg.sony.co.jp>
-
-	* io.c (io_check_closed): check for `fptr->f2 == NULL'.
-
-	* io.c (io_fptr_close): ditto.
-
-Mon Mar 16 11:49:25 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* io.c (pipe_atexit): free()ing referencing pipe_list.
-
-	* range.c (range_length): returns zero, if the first is greater
-	  than the last.
-
-	* signal.c (trap_restore_mask): restore signal mask before raising 
-	  exceptions and throws.
-
-Fri Mar 13 13:49:24 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* experimental release 1.1b9_02.
-
-	* object.c (mod_clone): need to dups constants and instance
-	  variables.
-
-	* eval.c (rb_eval): forgot to initialize body for NODE_DEFS.
-
-	* eval.c (rb_eval): retrieve self from calling frame, since self
-	  changes sometimes.
-
-	* env.h (FRAME): need to save self in the calling frame.
-
-	* io.c (f_gets_method): rs should be initialized by RS.
-
-Thu Mar 12 15:33:57 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* experimental release 1.1b9_01.
-
-	* range.c (range_s_new): check values by `first <= last'.
-
-	* parse.y (lastline_set): fixed offset for $_ and $~ in the local
-	  variable space.
-
-Wed Mar 11 02:14:17 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* io.c (io_gets): handle normal case specially for speed.
-
-	* eval.c (rb_disable_super): function to disable superclass's
-	  method explicitly.
-
-	* eval.c (rb_eval): inherits previous method definition's
-	  NOEX_UNDEF-ness, if exists.
-
-	* class.c (rb_define_method): disables superclass's overriding
- 	  method by default.
-
-Wed Mar 11 01:40:48 1998  MAEDA shugo  <shugo@po.aianet.ne.jp>
-
-	* numeric.c (flo_gt,etc.): do not depend on `<=>', to handle NaN.
-
-Tue Mar 10 00:03:24 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* ruby.c (load_file): understands multiple options in #! line.
-
-	* regex.c (re_compile_pattern): support for [:alpha:] etc.
-
-Mon Mar  9 16:53:51 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* io.h (GetOpenFile): embed io_check_closed in GetOpenFile.
-
-	* sprintf.c (f_sprintf): zero padding failed for negative
-	  integers.
-
-	* sprintf.c (remove_sign_bits): failed to remove some bits.
-
-Sat Mar  7 21:51:46 1998  MAEDA shugo  <shugo@po.aianet.ne.jp>
-
-	* class.c (ins_methods_i): body may be NULL for some case.
-
-Fri Mar  6 17:23:07 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* regex.c (mbcinit): table driven mbchar detection.
-
-	* object.c (obj_alloc): check for allocating instance for the
-	  primitive classes (mostly perfect).
-
-	* ext/curses/curses.c (curses_finalize): restore original state at 
-	  interpreter temination.
-
-	* ext/curses/curses.c (curses_addstr): forgot to check argument
-	  type (caused SEGV).  now uses STR2CSTR() macro.
-
-Thu Mar  5 13:47:39 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* eval.c (block_pass): accepts method object as block args.
-
-	* eval.c (f_missing): use any_to_s() for stringify.
-
-Wed Mar  4 01:39:52 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* parse.y (block_arg): new syntax - block argument in the
-	  calling arglist.
-
-	* eval.c (rb_call): no module search. simplified a lot.
-
-	* eval.c (rb_eval): block arg support.
-
-	* parse.y (f_block_arg): new syntax - block argument in the
- 	  formal arglist.
-
-Tue Mar  3 14:20:15 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* eval.c (obj_method): returns bound method object.
-
-	* eval.c (rb_call): argument check for empty methods.
-
-	* ruby.h (NUM2CHR): new macro, originally from curses module.
-
-Tue Mar  3 13:03:35 1998  MAEDA shugo  <shugo@po.aianet.ne.jp>
-
-	* io.c (io_putc): new method.
-
-Tue Mar  3 11:21:28 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* string.c (str_inspect): more strict charcode detection.
-
-	* eval.c (thread_stop): stopping only thread raises ThreadError
-	  exception.
-
-Tue Mar  3 08:04:56 1998  Tadayoshi Funaba  <tadf@kt.rim.or.jp>
-
-	* struct.c (struct_alloc): imcomplete struct initialization made
- 	  GC to access unallocated addresses.
-
-Mon Mar  2 16:28:27 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* eval.c (thread_stop_method): remove Thread#stop.
-
-Fri Feb 27 18:16:26 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* version 1.1b9 released.
-
-Fri Feb 27 09:36:35 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* hash.c (hash_delete_nil): needed to compare value to nil, since
-	  nil is the valid key for hashes.
-
-	* hash.c (hash_foreach_iter): rehashing causes IndexError.
-
-	* hash.c (hash_foreach_iter): rehash check by pointer comparison.
-
-Thu Feb 26 17:22:13 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* parse.y (fname): convert reswords into symbols.
-
-	* parse.y (reswords): reserved words are now embedded in the
- 	  syntax (sigh).
-
-	* parse.y: now reserved words can be method names safely.
-
-Wed Feb 25 15:50:07 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* eval.c (mod_module_eval): clear the_scope's PRIVATE flag before
-	  calling eval().
-
-	* gc.c (gc_call_finalizer_at_exit): run finalizers before any data 
-	  object being freed.
-
-	* eval.c (rb_eval): needed to keep prot_tag->retval before
-	  evaluating the ensure clause.
-
-Tue Feb 24 11:16:32 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* parse.y (yylex): reserved words can be appear as method names at
- 	  right after 'def' and `.'(dot), like foo.next.
-
-	* eval.c (return_check): checks for return out of thread (formerly
- 	  done in return_value).
-
-	* eval.c (POP_TAG): copy retval to outer level.
-
-	* eval.c (return_value): just set retval, no check, no unwinding.
-
-	* parse.y (nextc): line continuation by backslash at end of line.
-
-	* regex.c (re_compile_pattern): forgot to clear pending_exact on
-	  closing parentheses.
-
-	* parse.y (assignable): should not assign dyna_var to true, if it
- 	  is already defined.
-
-Mon Feb 23 14:35:03 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* object.c (obj_is_kind_of): no longer accepts true/false/nil.
-
-	* object.c ({true,false,nil}_to_i): can be converted into integers.
-
-Mon Feb 23 12:11:51 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* re.c (reg_s_quote): needed to be mbchar aware.
-
-	* eval.c (proc_s_new): wrong iter mark.
-
-Sat Feb 21 22:59:30 1998  MAEDA shugo  <shugo@po.aianet.ne.jp>
-
-	* io.c (f_syscall): no argument check.
-
-Fri Feb 20 10:17:51 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* version 1.1b8 released.
-
-	* ext/kconv/kconv.c (kconv_kconv): default output code now be
-	  determined according to the value of $KCODE.
-
-	* re.c (rb_get_kcode): can retrieve $KCODE from C code. 
-
-	* parse.y (stmt): if/unless modifiers returns nil, if condition is 
-	  not established.
-
-Thu Feb 19 11:06:47 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* ext/kconv/kconv.c (kconv_kconv): charcode can be specified by
-	  code name (JIS, SJIS, EUC like value of $KCODE).
-
-	* regex.c (re_compile_pattern): forgot to fixup_jump for (?:..).
-
-	* regex.c (re_compile_pattern): needed to clear pending_exact on
-	  non-registering grouping (?:...).
-
-Wed Feb 18 19:54:21 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* parse.y (here_document): needed to set lex_state to EXPR_END.
-
-Wed Feb 18 18:45:10 1998  WATANABE Hirofumi  <watanabe@ase.ptg.sony.co.jp>
-
-	* patches for cygwin32 applied.
-
-Wed Feb 18 00:41:31 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* string.c (str_sub_s): needed to be mbchar aware to increment one
- 	  character.
-
-	* regex.c (re_match): \Z matches newline just before the end of
-	  the string.
-
-Tue Feb 17 00:04:32 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* time.c (time_arg): Time.gm and Time.local now understands
- 	  Time#to_a format.
-
-	* string.c (str_sub_s): replace happened twice for null pattern.
-
-	* regex.c (re_search): null pattern should not match after newline 
-	  at the end of string.
-
-	* time.c (time_isdst): now returns boolean value.
-
-	* error.c (rb_check_type): treat special constants in messages.
-
-	* parse.y (yylex): new form `::Const' to see toplevel constants.
-
-	* parse.y (cond): SEGV on `if ()'.
-
-	* gc.c (obj_free): some data needed explicit free().
-
-Mon Feb 16 23:55:40 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* eval.c (blk_free): release duplicated block informations.
-
-	* eval.c (blk_copy_prev): duplicate outer block information into
- 	  the heap, when proc/binding created.
-
-Mon Feb 16 14:38:25 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* time.c (time_mon): now 1 for January and so on.
-
-	* time.c (time_year): year in 19xx (no + 1900 needed anymore).
-
-Mon Feb 16 13:28:33 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* regex.c (re_compile_pattern): need to fetch mbchar's second byte
- 	  without translation.
-
-Mon Feb 16 12:29:27 1998  MAEDA shugo  <shugo@po.aianet.ne.jp>
-
-	* eval.c (f_pass_block): pass iterator block to other method.
-
-Fri Feb 13 08:16:11 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* parse.y (parse_regx): handle \s before read_escape().
-
-	* parse.y (read_escape): `\s' in strings as space.
-
-Tue Feb 10 17:29:08 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* version 1.1b7 released.
-
-	* string.c (str_aset): string insertion by `str[n] = str2'.
-
-	* string.c (str_oct): does recognize `0x'.
-
- 	* sprintf.c (f_sprintf): use baes 10 for conversion from string to
- 	  integer.
-
-Mon Feb  9 14:51:56 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* numeric.c (do_coerce): proper error message.
-
-	* string.c (str_sum): bug - masked by wrong value. (sigh..)
-
-Sat Feb  7 15:11:14 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* string.c (str_empty): new method
-
-Fri Feb  6 01:42:15 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* time.c (time_asctime): use asctime(3), not strftime(3).
-
-Thu Feb  5 18:58:46 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* io.c (io_fptr_close): do not free path on close().
-
-	* array.c (ary_filter): new method.
-
-	* enum.c (enum_each_with_index): new method.
-
-Thu Feb  5 14:10:35 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* parse.y (primary): singleton class def can be appeared inside
- 	  method bodies.
-
-	* hash.c (hash_replace): replace content.
-
-	* string.c (str_replace_method): replace content.
-
-	* array.c (ary_replace_method): replace elements.
-
-	* string.c (str_succ_bang): String#succ!
-
-Thu Feb  5 18:20:30 1998  WATANABE Hirofumi  <watanabe@ase.ptg.sony.co.jp>
-
-	* string.c (str_upcase_bang): multi byte character support.
-
-Wed Feb  4 13:55:26 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* array.c (ary_reverse): SEGV on empty array reverse.
-
-Tue Feb  3 12:24:07 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* re.c (match_to_a): non matching element should be nil.
-
-	* ruby.c (ruby_load_script): load script after all initialization.
-
-	* bignum.c (str2inum): need to interpret prefix `0' of `0x'.
-
-Tue Feb  3 10:00:18 1998  WATANABE Hirofumi  <watanabe@ase.ptg.sony.co.jp>
-
-	* numeric.c (fix_rshift): use `sizeof(INT)*8' instead of 32.
-
-Mon Feb  2 14:09:24 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* ruby.c (set_arg0): grab environment region too.
-
-Thu Jan 29 18:36:25 1998  WATANABE Hirofumi  <watanabe@ase.ptg.sony.co.jp>
-
-	* process.c (rb_proc_exec): check `sh' to be exist.
-
-Thu Jan 29 18:18:19 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* io.c (io_stdio_set): assignment to $stdin or $stdout does
-	  reopen() as well as $stderr.
-
-Thu Jan 29 14:18:40 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* class.c (mod_ancestors): should not include singleton classes.
-
-	* object.c (obj_type): should not return internal class.
-
-	* io.c (io_reopen): unwillingly closes stdio streams.
-
-Thu Jan 29 11:50:35 1998  Toshihiko SHIMOKAWA  <toshi@csce.kyushu-u.ac.jp>
-
-	* ext/socket/socket.c (udp_addrsetup): forgot to use htons().
-
-Tue Jan 27 23:15:24 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* keywords: __FILE__, __LINE__ are available again.
-
-Fri Jan 23 14:19:28 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* version 1.1b6 released.
-
-	* object.c (mod_to_s): need to duplicate classpath.
-
-	* error.c (exc_inspect): need to duplicate classpath.
-
-Thu Jan 22 00:37:47 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* ruby.h (STR2CSTR): new macro to retrieve char*.
-
-	* class.c (rb_define_method): `initialize' should always be
-	  private, even if it defined by C extensions.
-
-	* eval.c (rb_eval): `initialize' should always be private.
-
-Thu Jan 22 16:21:08 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* eval.c (rb_eval): some singleton class def cause SEGV.
-
-	* eval.c (TMP_ALLOC): replace ALLOCA_N, where thread context
- 	  switch may happen.
-
-Wed Jan 21 01:43:42 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* eval.c (PUSH_FRAME): do not use ALLOCA_N().  crash on some
-	  platforms that use missing/alloca.c.
-
-	* regex.c (re_compile_pattern): too many pops for non register
-	  subexpr.
-
-	* parse.y (yylex): open parentheses after identifiers are argument 
-	  list, even if whitespaces have seen.
-
-Tue Jan 20 15:19:59 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* parse.y (terms): quoted word list by %w(a b c).
-
-	* ext/tcltklib/extconf.rb: more accurate check for tcl/tk libs.
-
-	* file.c (rb_stat): most of the FileTest methods (and function
- 	  `test') accept File objects as the argument.
-
-Tue Jan 19 18:19:24 1998  WATANABE Hirofumi  <watanabe@ase.ptg.sony.co.jp>
-
-	* ext/extmk.rb.in (install): there should be no newline after install:
-
-	* re.c (MIN): renamed from min().  there's a local variable named
- 	  min in the file, so that some cpp will raise an error.
-
-Mon Jan 19 16:30:05 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* version 1.1b5 released.
-
-	* process.c (rb_syswait): no exception raised.
-
-Fri Jan 16 00:43:43 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* ruby.h (CLONESETUP): copies its singleton classes too.
-
-	* class.c (singleton_class_attached): saves binded object in the
-	  singleton classes.
-
-	* eval.c (rb_eval): calls singleton_method_added even in the
-	  singleton class clauses.
-
-Fri Jan 15 23:22:43 1998  WATANABE Hirofumi  <watanabe@ase.ptg.sony.co.jp>
-
-	* ruby.c (proc_options): -S does not recognize PATH.
-
-Thu Jan 15 02:03:12 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* eval.c (rb_clear_cache_by_id): clear only affected cache
-	  entries.
-
-Wed Jan 14 02:14:48 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* ext/socket/socket.c: new UDP/IP socket classes.
-
-Tue Jan 13 10:00:18 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* string.c (str_cmp): ignorecase($=) works wrong.
-
-Fri Jan  9 13:19:55 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* version 1.1b4 released.
-
-	* eval.c (f_missing): class name omitted from the error message.
-
-	* error.c (exc_inspect): description changed.
-
-	* string.c (Init_String): GlobalExit's superclass did not filled,
-	  since GlobalExit created earlier than String.
-
-Thu Jan  8 12:10:09 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* parse.y (aryset): expr in the brackets can be null.
-
-Wed Jan  7 21:13:56 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* io.c (io_reopen): keep stderr unclosed.
-
-	* io.c (io_errset): keep stderr unclosed.
-
-Tue Jan  6 00:27:43 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* parse.y: syntax modified for `while expr do .. end' etc.
-
-	* process.c (f_exec,f_system): can supply arbitrary name for the
- 	  new process.
-
-Mon Jan  5 16:59:13 1998  WATANABE Hirofumi  <watanabe@ase.ptg.sony.co.jp>
-
-	* file.c (file_s_basename): removes any extention by ".*".
-
-Sun Jan  4 19:36:22 1998  WATANABE Hirofumi  <watanabe@ase.ptg.sony.co.jp>
-
-	* parse.y (yylex): needed to update lex_p (reading point).
-
-Sat Jan  3 19:14:14 1998  WATANABE Hirofumi  <watanabe@ase.ptg.sony.co.jp>
-
-	* class.c,object.c: duplicate defines mKernel and cFinxnum.
-
-Fri Jan  2 20:38:59 1998  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* ext/curses/curses.c (NUM2CHAR): uses the first character for
- 	  string arguments.
-
-	* array.c (ary_fill): did not extend array for ranges.
-
-	* array.c (beg_len): did not return end pos bigger than size.
-
-Fri Jan  2 02:09:16 1998  WATANABE Hirofumi  <watanabe@ase.ptg.sony.co.jp>
-
-	* dir.c (dir_s_chdir): bug in nil check.
-
-	* array.c (ary_fill): bug in nil check.
-
-Tue Dec 30 11:46:23 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* hash.c (env_path_tainted): checks directories in PATH
-	  environment variable are not world writable.
-
-	* ruby.c (load_file): invoke specified interpreter if the #! line
- 	  does not contain the word `ruby'.
-
-Fri Dec 26 03:26:41 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* string.c (uscore_get): type information included in the error
- 	  message.
-
-	* variable.c (f_untrace_var): does not free trace-data within
- 	  trace procedure.
-
-Thu Dec 25 02:50:29 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* version 1.1b3 released.
-
-	* ruby.h: inlining some functions on gcc 2.x
-
-Tue Dec 23 02:47:33 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* eval.c (rb_eval): public/private information kept in the current 
-	  scope, to remove undesired state from the class/module.
-
-	* time.c (time_strftime): remove hidden limit of 100 bytes of
-	  result string, using malloc'ed buffer. 
-
-	* hash.c (hash_update): merges the contents of another hash,
-	  overriding existing keys.
-
-	* regex.c (must_instr): totally re-written.
-
-	* io.c (read_all): try to allocate proper sized buffer using
-	  fstat(2) for speedup.
-
-Sat Dec 20 00:27:28 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* regex.c (must_instr): need to skip 2 bytes for mbchars.
-
-Fri Dec 19 01:18:29 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* version 1.1b2 released.
-
-	* eval.c (check_errat): check and convert (if necessary) traceback 
-	  information before assigning to the variable $@.
-
-	* eval.c (f_raise): optional third argument to specify traceback
-	  information.
-
-	* io.c (f_open): prevent infinite recursive call.
-
-Thu Dec 18 19:33:47 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* string.c (str_rindex): now accepts regexp as index.
-
-Thu Dec 18 18:42:50 1997  WATANABE Hirofumi  <watanabe@ase.ptg.sony.co.jp>
-
-	* ext/socket/extconf.rb: modified to detect win32 socket lib.
-
-Thu Dec 18 00:25:03 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* re.c (reg_equal): checks for source and casefold and kcode matching.
-
-	* marshal.c: became built-in module.
-
-	* ext/marshal/marshal.c (r_object): displays struct name for
-	  non-compatible struct.
-
-	* string.c (str_index_method): now searches character (fixnum) in
-	  the string.
-
-	* string.c (str_include): redefine `include?'.
-
-	* regex.c (re_match): start_nowidth saves current stack position
-	  to stop_nowidth.
-
-	* regex.c (re_compile_pattern): add space to stop_nowidth to save
-	  runtime stack position.
-
-Tue Dec 16 14:57:43 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* string.c (scan_once): wrong exception for regexp that match with 
-	  null string (use substr instead of subseq).
-
-Sat Dec 13 00:13:32 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* parse.y (expr): remove bare assocs from expr rule.
-
-	* rbconfig.rb: renamed from config.rb (it was too generic name).
-
-Fri Dec 12 00:50:25 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* parse.y (expr): warns if BEGIN or END appear in the method
- 	  bodies.
-
-	* string.c (str_match): calls y =~ x if y is neither String nor
-	  Regexp so that eregex.rb works.  
-
-	* eval.c (f_at_exit): to register end proc.
-
-	* class.c (rb_define_module_function): define 'function' method
-	  for the Module, not private method.
-
-	* class.c (rb_define_function): function to define `function' method.
-
-	* eval.c (rb_eval): inherit visibility from superclass's method
-	  except when it is set to `function'
-
-	* eval.c (rb_eval): new visibility status `function'.
-
-	* parse.y (yycompile): do not clear eval_tree. thus enable multipe 
-	  command line script by optn `-e'.
-
-	* eval.c (rb_eval): END execute just once.
-
-	* parse.y (expr): BEGIN/END built in the syntax.
-
-Thu Dec 11 13:14:35 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* object.c (mod_le): Module (or Class) comparison.
-
-	* eval.c (rb_remove_method): raises NameError if named method does 
-	  not exist.
-
-	* ext/curses/curses.c: remove CHECK macro for BSD curses.
-	
-Thu Dec 11 12:44:01 1997  WATANABE Hirofumi  <watanabe@ase.ptg.sony.co.jp>
-
-	* pack.c: sun4 cc patch
-
-Wed Dec 10 15:21:36 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* ext/marshal/marshal.c (marshal_load): can supply evolution proc
-	  object as optional second argument.
-
-	* re.c (reg_source): get source string of the regular expression.
-
-Tue Dec  9 10:05:17 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* version 1.1b1 released.
-
-	* parse.y (tokadd): token buffer overrun.
-
-	* ruby.c (ruby_prog_init): forgot to protect rb_argv0 from gc.
-
-	* eval.c (ruby_run): call finalizers at process termination.
-
-	* gc.c (gc_call_finalizer_at_exit): call free proc for every Data
- 	  Wrapper, and finalizer for specified objects at termination.
-
-	* version.c (show_version): version format changed.
-
-	* regex.c (re_match): wrong match with non-greedy if they appear
-	  more than once in regular expressions.
-
-	* sample/ruby-mode.el (ruby-expr-beg): forgot to handle modifiers.
-
-Mon Dec  8 19:00:15 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* io.c (io_puts): just put a newline if no argument given.
-
-	* ext/tcltklib/tcltklib.c (lib_mainloop): thread-aware tk handle
- 	  when $tk_thread_safe is set.
-
-	* ext/tcltklib/tcltklib.c (lib_mainloop): use Tcl_DoOneEvent()
-	  instead of Tk_MainLoop().
-
-Mon Dec  6 07:11:16 1997  MAEDA shugo  <shugo@po.aianet.ne.jp>
-
-	* io.c (io_puts): core dumped without any argument.
-
-Fri Dec  5 18:17:17 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* eval.c (mod_remove_method): remove (not undef) a method from the 
-	  class/module.
-
-	* variable.c (obj_remove_instance_variable): method to remove
-	  instance variables.
-
-Thu Dec  4 13:50:29 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* version 1.1b0 released.
-
-	* string.c (str_aref): called str_index for regexp.
-
-Mon Dec  1 15:24:41 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* compar.c (cmp_between): wrong comparison made.
-
-Wed Nov 26 18:18:05 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* lib/mkmf.rb: generate Makefile for extention modules out of ruby 
-	  source tree. use like `ruby -r mkmf extconf.rb'.
-
-	* numeric.c (fix2str): enlarge buffer to prevent overflow on some
-	  machines.
-
-	* parse.y (here_document): wrong line number generated after here-doc.
-
-Fri Nov 21 13:17:12 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* parse.y (yylex): skip multibyte characters in comments.
-
-Wed Nov 19 17:19:20 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* object.c (nil_to_a): nil.to_a => [].
-
-	* parse.y (call_args): wrong node generation.
-
-Tue Nov 18 10:13:08 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* array.c (Init_Array): Array#=== works as Array#include?
-
-	* regex.c (re_compile_pattern): insert initialize code for jump_n, 
-	  before entering loops.
-
-	* re.c (reg_search): does not save registers unless $& etc appear
-	  in the script.
-
-Mon Nov 17 13:01:43 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* eval.c (is_defined): add defined? check for receivers and
- 	  arguments for calls.
-
-	* re.c (reg_search): cache last match object.
-
-	* re.c (match_aref): $[0] etc. are available.
-
-Sat Nov 15 00:11:36 1997  WATANABE Hirofumi  <watanabe@ase.ptg.sony.co.jp>
-
-	* io.c (io_s_popen): "rb" detection
-
-Fri Nov 14 18:28:40 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* string.c (scan_once): returns whole match if the pattern does
-	  not contain any parentheses.
-
-Thu Nov 13 14:39:06 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* string.c (str_sub): returns copy of the receiver string, even if 
-	  any substitution occurred.
-
-	* regex.c (re_compile_pattern): no-width match by (?=..), (?!..).
-
-Wed Nov 12 13:44:47 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* time.c: remove coerce from Time class.
-
-	* regex.c (re_match): non-greedy match by ??, *? +?, {n,m}?.
-
-Mon Nov 10 11:24:51 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* regex.c (re_compile_pattern): non-resitering parens (?:..).
-
-	* regex.c (re_compile_pattern): new meta character \< (wordbeg)
-	  and \> (wordend).
-
-	* regex.c (re_compile_pattern): embedded comment for regular
-	  expression by (?#...).
-
-Fri Nov  7 16:58:24 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* regex.c (re_compile_pattern): perl5 regxp \A and \Z available.
-
-	* regex.c (re_compile_pattern): can expand compile stack dynamically.
-
-	* regex.c (PUSH_FAILURE_POINT): wrong compare condition.
-
-Wed Nov  2 16:00:00 1997  WATANABE Hirofumi  <watanabe@ase.ptg.sony.co.jp>
-
-	* string.c (str_sub_s): "".sub! "", "" => "\000"
-
-Fri Oct 31 15:52:10 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* parse.y (assoc): keyword assoc like {fg->"black"}.
-
-Thu Oct 30 17:33:38 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* io.c (io_println): print with newline, which is not affected by
-	  the values of $/ and $\.
-
-Thu Oct 30 16:54:01 1997  WATANABE Hirofumi  <watanabe@ase.ptg.sony.co.jp>
-
-	* string.c (str_chop_bang): "".chop caused SEGV.
-
-	* string.c (str_chomp_bang): method to chop out last newline.
-
-Mon Oct 27 13:49:13 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* ext/extmk.rb.in: library may have pathname contains `.'
-
-	* eval.c (rb_rescue): should not protect SystemError.
-
-Fri Oct 24 10:58:53 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* io.c (io_s_with_open_stream): ensures to close stream.
-
-Thu Oct 23 11:17:44 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* io.c (io_errset): value of $stderr can be changed (to any IO
- 	  object).
-
-	* io.c (next_argv): $< can be anything that responds to `write'.
-
-	* file.c (file_s_with_open_file): ensures to close file.
-
-	* error.c (exception): create error under the current class/module.
-
-	* range.c (range_eqq): fixnum check for last needed too.
-
-Wed Oct 22 12:52:30 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* ext/socket/socket.c: Socket::Constants added.
-
-	* file.c: File::Constants added for inclusion.
-
-	* array.c (ary_join): call ary_join() recursively for the 1st
- 	  array element.
-
-Mon Oct 20 12:18:29 1997  WATANABE Hirofumi  <watanabe@ase.ptg.sony.co.jp>
-
-	* ruby.c (load_file): wrong condition for #! check with -x.
-
-	* file.c (file_s_dirname): did return "" for "/a".
-
-Fri Oct 17 14:29:09 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* ruby.c: now works on alpha-linux.
-
-	* bignum.c (bigadd): some undefined side effect order assumed.
-
-Wed Oct 15 17:49:24 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* intern.h: function prototypes added.
-
-Mon Oct 13 16:54:18 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* class.c (rb_define_class_id): call superclass's `inherited'
- 	  method when making subclasses.
-
-	* parse.y (nextc): clear lex_lastline at the end of file.
-
-	* object.c (Init_Object): need to undef Class#append_features.
-
-	* eval.c (rb_eval): no warning on extending classes or modules.
-
-Thu Oct  9 11:17:50 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* eval.c (error_print): the exception name follows after the error 
-	  message.
-
-	* eval.c (compile_error): error message slightly changed.
-
-	* parse.y (nextc): script parsing will be terminated by __END__ at
- 	  beginning of line.
-
-	* eval.c (compile_error): `__END__' is no longer a keyword.
-
-	* parse.y (nextc): protect lastline read from script stream.
-
-Tue Oct  7 14:06:06 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* version 1.1 alpha9 released.
-
-	* eval.c (mod_append_features): renamed from extend_class.
-
-	* eval.c (rb_eval): defining method calls `method_added'.
-
-	* eval.c (ruby_options): exception while processing options must
-	  terminate the interpreter.
-
-	* error.c (Init_Exception): wrong method configuration.  `new'
-	  should have been a singleton method.
-
-Mon Oct  6 18:55:38 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* ext/kconv/kconv.c (kconv_guess): code to guess character code
-	  from string.
-
-Mon Oct  6 18:38:17 1997  WATANABE Hirofumi  <watanabe@ase.ptg.sony.co.jp>
-
-	* pack.c: now encode/decode base64 by `m' template.
-
-Fri Oct  3 10:51:10 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* MANIFEST: needed to include lex.c in the distribution.
-
-	* eval.c (ruby_options): f_require() called too early.
-
-	* eval.c (rb_provide): module extentions should always be `.o'.
-
-Thu Oct  2 11:38:31 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* version 1.1 alpha8 released.
-
-	* ext/marshal/marshal.c (r_object): remove temporal regist for
- 	  structs. (caused problem if structs form cycles.)
-
-	* parse.y (match_gen): static binding for match(=~) calls
-	  with regexp literals.
-
-Wed Oct  1 15:26:55 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* eval.c: protect retval in struct tag from GC for C_ALLOCA.
-
-	* eval.c: no more pointer value from setjmp/longjmp.
-
-Wed Oct  1 14:01:49 1997  WATANABE Hirofumi  <watanabe@ase.ptg.sony.co.jp>
-
-	* ext/marshal/marshal.c (w_byte): argument must be char.
-
-Wed Oct  1 10:30:22 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* variable.c (mod_const_at): global constants now belongs to the
-	  class Object.
-
-	* object.c (Init_Object): new global constant NIL.
-
-	* ext/marshal/marshal.c (marshal_dump): try to set binmode.
-
-	* ext/marshal/marshal.c (r_object): forgot to re-regist structs in 
-	  the object table.
-
-	* eval.c (ruby_options): call Init_ext() before any require()
- 	  calls by `-r'.
-
-Fri Sep 30 14:29:22 1997  WATANABE Hirofumi  <watanabe@ase.ptg.sony.co.jp>
-
-	* ext/marshal/marshal.c (w_object): marshal dumped core.
-
-Tue Sep 30 10:27:39 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* sample/test.rb: bignum test suits added.
-
-	* eval.c (rb_eval): new pseudo variable `true' and `false'.
-
-	* parse.y: new keywords `true' and `false' added.
-
-Mon Sep 29 13:37:58 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* ruby.c (forbid_setid): forbid some options in suid mode.
-
-	* ruby.h (NUM2DBL): new macro to convert into doubles.
-
-Mon Sep 27 09:53:48 1997  EGUCHI Osamu  <eguchi@shizuokanet.or.jp>
-
-	* bignum.c: modified for speeding.
-
-Fri Sep 26 18:27:59 1997  WATANABE Hirofumi  <watanabe@ase.ptg.sony.co.jp>
-
-	* sample/from.rb: some extensions.
-
-Mon Sep 29 13:15:56 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* parse.y (lhs): no more syntax error on `obj.CONSTANT = value'.
-
-Fri Sep 26 14:41:46 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* eval.c (ruby_run): deferred calling Init_ext() just before eval_node.
-
-Fri Sep 26 13:27:24 1997  WATANABE Hirofumi  <watanabe@ase.ptg.sony.co.jp>
-
-	* io.c (io_isatty): forgot to return TRUE value.
-
-Fri Sep 25 11:10:58 1997  EGUCHI Osamu  <eguchi@shizuokanet.or.jp>
-
-	* eval.c: use _setjmp/_longjmp instead of setjmp/longjmp on some
-	  platforms.
-
-Wed Sep 24 17:43:13 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* string.c (Init_String): String#taint and String#taint? added.
-
-	* class.c (mod_ancestors): ancestors include the class itself.
-
-Wed Sep 24 00:57:00 1997  Katsuyuki Okabe  <HGC02147@niftyserve.or.jp>
-
-	* X68000 patch.
-
-Tue Sep 23 20:42:30 1997  EGUCHI Osamu  <eguchi@shizuokanet.or.jp>
-
-	* parse.y (node_newnode): SEGV on null node setup.
-
-Mon Sep 22 11:22:46 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* ruby.c (ruby_prog_init): wrong safe condition check.
-
-Sun Sep 21 14:46:02 1997  MAEDA shugo  <shugo@po.aianet.ne.jp>
-
-	* error.c (exc_inspect): garbage added to classpath.
-
-Fri Sep 19 11:49:23 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* parse.y (newtok): forgot to adjust buffer size when shrinking
-	  the token buffer.
-
-	* enum.c (enum_find): rb_eval_cmd() does not return value.
-
-	* io.c (pipe_open): close fds on pipe exec. fcntl(fd, F_SETFD, 1)
-	  no longer used.
-
-Tue Sep 16 17:54:25 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* file.c (f_test): problem if wrong command specified.
-
-	* ruby.c (ruby_prog_init): close stdaux and stdprn for MSDOS.
-
-	* ruby.c (ruby_prog_init): should not add path from environment
-	  variable, if ruby is running under seuid.
-
-	* process.c (init_ids): check suid check for setuid/seteuid etc.
-
-Mon Sep 15 00:42:04 1997  WATANABE Hirofumi  <watanabe@ase.ptg.sony.co.jp>
-
-	* regex.c (re_compile_pattern): \w{3} and \W{3} did not work.
-
-Thu Sep 11 10:31:48 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* version 1.1 alpha7 released.
-
-	* ext/socket/socket.c (sock_new): no setbuf() for NT.
-
-	* io.c (rb_fopen,rb_fdopen): set close-on-exec for every fd.
-
-Wed Sep 10 15:55:31 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* ext/marshal/marshal.c (r_bytes0): extra big length check.
-
-Tue Sep  9 16:27:14 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* io.c (pipe_fptr_atexit): clean up popen()'ed fptr.
-
-	* error.c (set_syserr): some system has error code that is bigger
-	  than sys_nerr. grrr.
-
-Mon Sep  8 18:33:33 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* io.c (io_s_new): dereferenced nil for optional mode.
-
-Fri Sep  5 10:26:03 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* class.c (class_instance_methods): do not include methods which
-	  are changed to private in subclasses.
-
-Thu Sep  4 12:38:53 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* variable.c (f_global_variables): list name of the global
-	  variables.
-
-	* object.c (obj_id): returns unique integer.
-
-Wed Sep  3 14:05:16 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* version 1.1 alpha6 released.
-
-	* eval.c (mod_s_constants): context sensitive constant list.
-
-	* variable.c (mod_constants): no more `all' option.
-
-	* variable.c (mod_const_of): the values for autoload classes are
-	  their name strings.
-
-	* class.c (class_instance_methods): no special treatment for
-	  singleton classes.
-
-	* object.c (obj_singleton_methods): returns list of singleton
-	  method names.
-
-	* parse.y (yylex): no here document after `class' keyword.
-
-	* eval.c (f_load): expand path if fname begins with `~'.
-
-Tue Sep  2 13:19:48 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* class.c (ins_methods_i): do not list undef'ed methods.
-
-Mon Sep  1 13:42:48 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* version 1.1 alpha5 released.
-
-	* object.c (mod_attr_reader): create methods to define attribute
- 	  reader/write/accessor.
-
-	* class.c (rb_define_attr): always defines accessors.
-
-	* eval.c (rb_call): alias occured in the module body caused SEGV.
-
-	* parse.y: did not generate here document strings properly.
-
-Mon Sep  1 11:43:57 1997  WATANABE Hirofumi  <watanabe@ase.ptg.sony.co.jp>
-	
-	* parse.y (yylex): heredoc dropped an extra character.
-
-Fri Aug 29 11:10:21 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* class.c (class_instance_methods): same method names should not
- 	  appear more than twice.
-
-	* parse.y (yylex): spaces can follow =begin/=end.
-
-	* variable.c (find_class_path): look for class_tbl also for
-	  unnamed fundamental classes, such as Object, String, etc.
-
-	* variable.c (rb_name_class): can't name class before String class
- 	  is initilialized.
-
-	* inits.c (rb_call_inits): unrecognized dependency from GC to
-	  Array.
-
-	* variable.c (find_class_path): could not find class if Object's
- 	  iv_tbl is NULL.
-
-Thu Aug 28 13:12:05 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* version 1.1 alpha4 released.
-
-	* variable.c (mod_constants): wrong condition for singleton
-	  class. 
-
-	* parse.y (yylex): revised `=begin' skip code.
-
-	* parse.y (here_document): forgot to free(eos).
-
-	* parse.y (yylex): spaces after `<<' prohibited for here
- 	  documents to avoid confusing with operator `<<'.
-
-	* eval.c (is_defined): separated from rb_eval().
-
-Wed Aug 27 11:32:42 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* version 1.1 alpha3 released.
-
-	* variable.c (mod_name): returns name of the class/module.
-
-	* parse.y (here_document): finally here document available now.
-
-	* variable.c (fc_i): some classes/modules does not have iv_tbl.
-
-	* variable.c (find_class_path): avoid inifinite loop.
-
-Tue Aug 26 13:43:47 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* eval.c (rb_eval): undef'ing non-existing method will raise
-	  NameError exception.
-
-	* object.c (class_s_new): needed to create metaclass too.
-
-	* eval.c (error_print): no class name print for anonymous class.
-
-	* eval.c (rb_longjmp): proper exception raised if raise() called
- 	  without arguments, with $! or $@ set.
-
-	* object.c (Init_Object): superclass()'s method argument setting
- 	  was wrong again.
-
-	* class.c (mod_anscestors): list superclasses and included modules 
-	  in priority order.
-
-Mon Aug 25 11:53:11 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* version 1.1 alpha2 released.
-
-	* sample/ruby-mode.el (ruby-parse-region): auto-indent now
- 	  supports "\\" in the strings.
-
-	* struct.c (struct_getmember): new API to get member value from C
-	  language side.
-
-Sat Aug 23 21:39:05 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* parse.y (asignable): remove unnecessary local variable
-	  initialize by nil.
-
-Fri Aug 22 14:26:40 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* eval.c (error_print): modified exception print format.
-
-Thu Aug 21 16:10:58 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* sample/ruby-mode.el (ruby-calculate-indent): wrong indent level
-	  calculated with keyword operators.
-
-Thu Aug 21 11:36:58 1997  WATANABE Hirofumi  <watanabe@ase.ptg.sony.co.jp>
-
-	* parse.y (arg): ary[0] += 1 cause SEGV
-
-Wed Aug 20 17:28:50 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* ruby.c (ruby_process_options): require() all modules after
- 	  processing all options
-
-	* process.c (rb_proc_exec): more security checks added.
-
-	* process.c (rb_proc_exec): insecure path on exec.
-
-	* hash.c (f_getenv): PATH modification security check.
-
-Tue Aug 19 00:15:38 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* version 1.1 alpha1 released.
-
-	* eval.c (mod_eval): work as normal eval() if second binding
- 	  argument given.
-
-	* eval.c (rb_call): did not raise ArgumentError if too many
- 	  arguments more than optional arguments (without rest arg).
-
-	* eval.c (rb_eval): did not work well for op_asgn2 (attribute
-	  self assignment).
-
-	* eval.c (Init_Thread): returns main thread.
-
-Mon Aug 18 09:25:56 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* object.c (inspect_i): did not display T_DATA instance variables.
-
-	* parse.y: provides more accurate line number information.
-
-	* eval.c (thread_value): include value's backtrace information in
-	  the variable `$@'. 
-
-	* eval.c (f_abort): print backtrace and exit.
-
-Sat Aug 16 00:17:44 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* eval.c (class_new_instance): do not make instance from virtual
-	  classes. 
-
-	* object.c (class_s_new): do not make subclass of singleton class.
-
-Fri Aug 15 15:49:46 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* eval.c (call_trace_func): block context switch in the trace
-          function.
-
-	* eval.c (rb_eval): clear method cache at class extention.
-
-	* object.c (obj_type): returns object's class even if it defines
-	  singleton methods.
-
-Fri Aug 15 19:40:43 1997  WATANABE Hirofumi  <watanabe@ase.ptg.sony.co.jp>
-
-	* ext/socket/socket.c (Init_socket): small typo caused SEGV.
-
-Wed Aug 13 17:51:46 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* version 1.1 alpha0 released.
-
diff --git a/GPL b/GPL
new file mode 100644
index 0000000000..d159169d10
--- /dev/null
+++ b/GPL
@@ -0,0 +1,339 @@
+                    GNU GENERAL PUBLIC LICENSE
+                       Version 2, June 1991
+
+ Copyright (C) 1989, 1991 Free Software Foundation, Inc.,
+ 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ Everyone is permitted to copy and distribute verbatim copies
+ of this license document, but changing it is not allowed.
+
+                            Preamble
+
+  The licenses for most software are designed to take away your
+freedom to share and change it.  By contrast, the GNU General Public
+License is intended to guarantee your freedom to share and change free
+software--to make sure the software is free for all its users.  This
+General Public License applies to most of the Free Software
+Foundation's software and to any other program whose authors commit to
+using it.  (Some other Free Software Foundation software is covered by
+the GNU Lesser General Public License instead.)  You can apply it to
+your programs, too.
+
+  When we speak of free software, we are referring to freedom, not
+price.  Our General Public Licenses are designed to make sure that you
+have the freedom to distribute copies of free software (and charge for
+this service if you wish), that you receive source code or can get it
+if you want it, that you can change the software or use pieces of it
+in new free programs; and that you know you can do these things.
+
+  To protect your rights, we need to make restrictions that forbid
+anyone to deny you these rights or to ask you to surrender the rights.
+These restrictions translate to certain responsibilities for you if you
+distribute copies of the software, or if you modify it.
+
+  For example, if you distribute copies of such a program, whether
+gratis or for a fee, you must give the recipients all the rights that
+you have.  You must make sure that they, too, receive or can get the
+source code.  And you must show them these terms so they know their
+rights.
+
+  We protect your rights with two steps: (1) copyright the software, and
+(2) offer you this license which gives you legal permission to copy,
+distribute and/or modify the software.
+
+  Also, for each author's protection and ours, we want to make certain
+that everyone understands that there is no warranty for this free
+software.  If the software is modified by someone else and passed on, we
+want its recipients to know that what they have is not the original, so
+that any problems introduced by others will not reflect on the original
+authors' reputations.
+
+  Finally, any free program is threatened constantly by software
+patents.  We wish to avoid the danger that redistributors of a free
+program will individually obtain patent licenses, in effect making the
+program proprietary.  To prevent this, we have made it clear that any
+patent must be licensed for everyone's free use or not licensed at all.
+
+  The precise terms and conditions for copying, distribution and
+modification follow.
+
+                    GNU GENERAL PUBLIC LICENSE
+   TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
+
+  0. This License applies to any program or other work which contains
+a notice placed by the copyright holder saying it may be distributed
+under the terms of this General Public License.  The "Program", below,
+refers to any such program or work, and a "work based on the Program"
+means either the Program or any derivative work under copyright law:
+that is to say, a work containing the Program or a portion of it,
+either verbatim or with modifications and/or translated into another
+language.  (Hereinafter, translation is included without limitation in
+the term "modification".)  Each licensee is addressed as "you".
+
+Activities other than copying, distribution and modification are not
+covered by this License; they are outside its scope.  The act of
+running the Program is not restricted, and the output from the Program
+is covered only if its contents constitute a work based on the
+Program (independent of having been made by running the Program).
+Whether that is true depends on what the Program does.
+
+  1. You may copy and distribute verbatim copies of the Program's
+source code as you receive it, in any medium, provided that you
+conspicuously and appropriately publish on each copy an appropriate
+copyright notice and disclaimer of warranty; keep intact all the
+notices that refer to this License and to the absence of any warranty;
+and give any other recipients of the Program a copy of this License
+along with the Program.
+
+You may charge a fee for the physical act of transferring a copy, and
+you may at your option offer warranty protection in exchange for a fee.
+
+  2. You may modify your copy or copies of the Program or any portion
+of it, thus forming a work based on the Program, and copy and
+distribute such modifications or work under the terms of Section 1
+above, provided that you also meet all of these conditions:
+
+    a) You must cause the modified files to carry prominent notices
+    stating that you changed the files and the date of any change.
+
+    b) You must cause any work that you distribute or publish, that in
+    whole or in part contains or is derived from the Program or any
+    part thereof, to be licensed as a whole at no charge to all third
+    parties under the terms of this License.
+
+    c) If the modified program normally reads commands interactively
+    when run, you must cause it, when started running for such
+    interactive use in the most ordinary way, to print or display an
+    announcement including an appropriate copyright notice and a
+    notice that there is no warranty (or else, saying that you provide
+    a warranty) and that users may redistribute the program under
+    these conditions, and telling the user how to view a copy of this
+    License.  (Exception: if the Program itself is interactive but
+    does not normally print such an announcement, your work based on
+    the Program is not required to print an announcement.)
+
+These requirements apply to the modified work as a whole.  If
+identifiable sections of that work are not derived from the Program,
+and can be reasonably considered independent and separate works in
+themselves, then this License, and its terms, do not apply to those
+sections when you distribute them as separate works.  But when you
+distribute the same sections as part of a whole which is a work based
+on the Program, the distribution of the whole must be on the terms of
+this License, whose permissions for other licensees extend to the
+entire whole, and thus to each and every part regardless of who wrote it.
+
+Thus, it is not the intent of this section to claim rights or contest
+your rights to work written entirely by you; rather, the intent is to
+exercise the right to control the distribution of derivative or
+collective works based on the Program.
+
+In addition, mere aggregation of another work not based on the Program
+with the Program (or with a work based on the Program) on a volume of
+a storage or distribution medium does not bring the other work under
+the scope of this License.
+
+  3. You may copy and distribute the Program (or a work based on it,
+under Section 2) in object code or executable form under the terms of
+Sections 1 and 2 above provided that you also do one of the following:
+
+    a) Accompany it with the complete corresponding machine-readable
+    source code, which must be distributed under the terms of Sections
+    1 and 2 above on a medium customarily used for software interchange; or,
+
+    b) Accompany it with a written offer, valid for at least three
+    years, to give any third party, for a charge no more than your
+    cost of physically performing source distribution, a complete
+    machine-readable copy of the corresponding source code, to be
+    distributed under the terms of Sections 1 and 2 above on a medium
+    customarily used for software interchange; or,
+
+    c) Accompany it with the information you received as to the offer
+    to distribute corresponding source code.  (This alternative is
+    allowed only for noncommercial distribution and only if you
+    received the program in object code or executable form with such
+    an offer, in accord with Subsection b above.)
+
+The source code for a work means the preferred form of the work for
+making modifications to it.  For an executable work, complete source
+code means all the source code for all modules it contains, plus any
+associated interface definition files, plus the scripts used to
+control compilation and installation of the executable.  However, as a
+special exception, the source code distributed need not include
+anything that is normally distributed (in either source or binary
+form) with the major components (compiler, kernel, and so on) of the
+operating system on which the executable runs, unless that component
+itself accompanies the executable.
+
+If distribution of executable or object code is made by offering
+access to copy from a designated place, then offering equivalent
+access to copy the source code from the same place counts as
+distribution of the source code, even though third parties are not
+compelled to copy the source along with the object code.
+
+  4. You may not copy, modify, sublicense, or distribute the Program
+except as expressly provided under this License.  Any attempt
+otherwise to copy, modify, sublicense or distribute the Program is
+void, and will automatically terminate your rights under this License.
+However, parties who have received copies, or rights, from you under
+this License will not have their licenses terminated so long as such
+parties remain in full compliance.
+
+  5. You are not required to accept this License, since you have not
+signed it.  However, nothing else grants you permission to modify or
+distribute the Program or its derivative works.  These actions are
+prohibited by law if you do not accept this License.  Therefore, by
+modifying or distributing the Program (or any work based on the
+Program), you indicate your acceptance of this License to do so, and
+all its terms and conditions for copying, distributing or modifying
+the Program or works based on it.
+
+  6. Each time you redistribute the Program (or any work based on the
+Program), the recipient automatically receives a license from the
+original licensor to copy, distribute or modify the Program subject to
+these terms and conditions.  You may not impose any further
+restrictions on the recipients' exercise of the rights granted herein.
+You are not responsible for enforcing compliance by third parties to
+this License.
+
+  7. If, as a consequence of a court judgment or allegation of patent
+infringement or for any other reason (not limited to patent issues),
+conditions are imposed on you (whether by court order, agreement or
+otherwise) that contradict the conditions of this License, they do not
+excuse you from the conditions of this License.  If you cannot
+distribute so as to satisfy simultaneously your obligations under this
+License and any other pertinent obligations, then as a consequence you
+may not distribute the Program at all.  For example, if a patent
+license would not permit royalty-free redistribution of the Program by
+all those who receive copies directly or indirectly through you, then
+the only way you could satisfy both it and this License would be to
+refrain entirely from distribution of the Program.
+
+If any portion of this section is held invalid or unenforceable under
+any particular circumstance, the balance of the section is intended to
+apply and the section as a whole is intended to apply in other
+circumstances.
+
+It is not the purpose of this section to induce you to infringe any
+patents or other property right claims or to contest validity of any
+such claims; this section has the sole purpose of protecting the
+integrity of the free software distribution system, which is
+implemented by public license practices.  Many people have made
+generous contributions to the wide range of software distributed
+through that system in reliance on consistent application of that
+system; it is up to the author/donor to decide if he or she is willing
+to distribute software through any other system and a licensee cannot
+impose that choice.
+
+This section is intended to make thoroughly clear what is believed to
+be a consequence of the rest of this License.
+
+  8. If the distribution and/or use of the Program is restricted in
+certain countries either by patents or by copyrighted interfaces, the
+original copyright holder who places the Program under this License
+may add an explicit geographical distribution limitation excluding
+those countries, so that distribution is permitted only in or among
+countries not thus excluded.  In such case, this License incorporates
+the limitation as if written in the body of this License.
+
+  9. The Free Software Foundation may publish revised and/or new versions
+of the General Public License from time to time.  Such new versions will
+be similar in spirit to the present version, but may differ in detail to
+address new problems or concerns.
+
+Each version is given a distinguishing version number.  If the Program
+specifies a version number of this License which applies to it and "any
+later version", you have the option of following the terms and conditions
+either of that version or of any later version published by the Free
+Software Foundation.  If the Program does not specify a version number of
+this License, you may choose any version ever published by the Free Software
+Foundation.
+
+  10. If you wish to incorporate parts of the Program into other free
+programs whose distribution conditions are different, write to the author
+to ask for permission.  For software which is copyrighted by the Free
+Software Foundation, write to the Free Software Foundation; we sometimes
+make exceptions for this.  Our decision will be guided by the two goals
+of preserving the free status of all derivatives of our free software and
+of promoting the sharing and reuse of software generally.
+
+                            NO WARRANTY
+
+  11. BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY
+FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW.  EXCEPT WHEN
+OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES
+PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED
+OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.  THE ENTIRE RISK AS
+TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU.  SHOULD THE
+PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING,
+REPAIR OR CORRECTION.
+
+  12. IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
+WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR
+REDISTRIBUTE THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES,
+INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING
+OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED
+TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY
+YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER
+PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE
+POSSIBILITY OF SUCH DAMAGES.
+
+                     END OF TERMS AND CONDITIONS
+
+            How to Apply These Terms to Your New Programs
+
+  If you develop a new program, and you want it to be of the greatest
+possible use to the public, the best way to achieve this is to make it
+free software which everyone can redistribute and change under these terms.
+
+  To do so, attach the following notices to the program.  It is safest
+to attach them to the start of each source file to most effectively
+convey the exclusion of warranty; and each file should have at least
+the "copyright" line and a pointer to where the full notice is found.
+
+    <one line to give the program's name and a brief idea of what it does.>
+    Copyright (C) <year>  <name of author>
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License along
+    with this program; if not, write to the Free Software Foundation, Inc.,
+    51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+
+Also add information on how to contact you by electronic and paper mail.
+
+If the program is interactive, make it output a short notice like this
+when it starts in an interactive mode:
+
+    Gnomovision version 69, Copyright (C) year name of author
+    Gnomovision comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
+    This is free software, and you are welcome to redistribute it
+    under certain conditions; type `show c' for details.
+
+The hypothetical commands `show w' and `show c' should show the appropriate
+parts of the General Public License.  Of course, the commands you use may
+be called something other than `show w' and `show c'; they could even be
+mouse-clicks or menu items--whatever suits your program.
+
+You should also get your employer (if you work as a programmer) or your
+school, if any, to sign a "copyright disclaimer" for the program, if
+necessary.  Here is a sample; alter the names:
+
+  Yoyodyne, Inc., hereby disclaims all copyright interest in the program
+  `Gnomovision' (which makes passes at compilers) written by James Hacker.
+
+  <signature of Ty Coon>, 1 April 1989
+  Ty Coon, President of Vice
+
+This General Public License does not permit incorporating your program into
+proprietary programs.  If your program is a subroutine library, you may
+consider it more useful to permit linking proprietary applications with the
+library.  If this is what you want to do, use the GNU Lesser General
+Public License instead of this License.
diff --git a/KNOWNBUGS.rb b/KNOWNBUGS.rb
new file mode 100644
index 0000000000..35a8e75876
--- /dev/null
+++ b/KNOWNBUGS.rb
@@ -0,0 +1,7 @@
+#
+# IMPORTANT: Always keep the first 7 lines (comments),
+# even if this file is otherwise empty.
+#
+# This test file includes tests which point out known bugs.
+# So all tests will cause failure.
+#
diff --git a/LEGAL b/LEGAL
new file mode 100644
index 0000000000..2a7964e771
--- /dev/null
+++ b/LEGAL
@@ -0,0 +1,1051 @@
+# -*- rdoc -*-
+
+= LEGAL NOTICE INFORMATION
+--------------------------
+
+All the files in this distribution are covered under either the Ruby's
+license (see the file COPYING) or public-domain except some files
+mentioned below.
+
+[addr2line.c]
+
+  A part of this file is from FreeBSD.
+
+  >>>
+    Copyright (c) 1986, 1988, 1991, 1993::
+    The Regents of the University of California.  All rights reserved.
+
+    (c) UNIX System Laboratories, Inc.
+
+    All or some portions of this file are derived from material licensed
+    to the University of California by American Telephone and Telegraph
+    Co. or Unix System Laboratories, Inc. and are reproduced herein with
+    the permission of UNIX System Laboratories, Inc.
+
+    Redistribution and use in source and binary forms, with or without
+    modification, are permitted provided that the following conditions
+    are met:
+    1. Redistributions of source code must retain the above copyright
+       notice, this list of conditions and the following disclaimer.
+    2. Redistributions in binary form must reproduce the above copyright
+       notice, this list of conditions and the following disclaimer in the
+       documentation and/or other materials provided with the distribution.
+    4. Neither the name of the University nor the names of its contributors
+       may be used to endorse or promote products derived from this software
+       without specific prior written permission.
+
+    THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+    ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+    IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+    ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+    FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+    DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+    OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+    HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+    LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+    OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+    SUCH DAMAGE.
+
+	@(#)subr_prf.c	8.3 (Berkeley) 1/21/94
+
+
+[ccan/build_assert/build_assert.h]
+[ccan/check_type/check_type.h]
+[ccan/container_of/container_of.h]
+[ccan/str/str.h]
+
+  These files are licensed under the {CC0}[https://creativecommons.org/choose/zero/].
+
+[ccan/list/list.h]
+
+  This file is licensed under the {MIT License}[rdoc-label:label-MIT+License].
+
+[coroutine]
+
+  Unless otherwise specified, these files are licensed under the
+  {MIT License}[rdoc-label:label-MIT+License].
+
+[include/ruby/onigmo.h]
+[include/ruby/oniguruma.h]
+[regcomp.c]
+[regenc.c]
+[regenc.h]
+[regerror.c]
+[regexec.c]
+[regint.h]
+[regparse.c]
+[regparse.h]
+[enc/ascii.c]
+[enc/big5.c]
+[enc/cp949.c]
+[enc/emacs_mule.c]
+[enc/encdb.c]
+[enc/euc_jp.c]
+[enc/euc_kr.c]
+[enc/euc_tw.c]
+[enc/gb18030.c]
+[enc/gb2312.c]
+[enc/gbk.c]
+[enc/iso_8859_1.c]
+[enc/iso_8859_10.c]
+[enc/iso_8859_11.c]
+[enc/iso_8859_13.c]
+[enc/iso_8859_14.c]
+[enc/iso_8859_15.c]
+[enc/iso_8859_16.c]
+[enc/iso_8859_2.c]
+[enc/iso_8859_3.c]
+[enc/iso_8859_4.c]
+[enc/iso_8859_5.c]
+[enc/iso_8859_6.c]
+[enc/iso_8859_7.c]
+[enc/iso_8859_8.c]
+[enc/iso_8859_9.c]
+[enc/koi8_r.c]
+[enc/koi8_u.c]
+[enc/shift_jis.c]
+[enc/unicode.c]
+[enc/us_ascii.c]
+[enc/utf_16be.c]
+[enc/utf_16le.c]
+[enc/utf_32be.c]
+[enc/utf_32le.c]
+[enc/utf_8.c]
+[enc/windows_1251.c]
+[enc/windows_31j.c]
+
+  Onigmo (Oniguruma-mod) LICENSE
+
+  >>>
+    Copyright (c) 2002-2009::  K.Kosako  <sndgk393 AT ybb DOT ne DOT jp>
+    Copyright (c) 2011-2014::  K.Takata  <kentkt AT csc DOT jp>
+    All rights reserved.
+
+    Redistribution and use in source and binary forms, with or without
+    modification, are permitted provided that the following conditions
+    are met:
+    1. Redistributions of source code must retain the above copyright
+       notice, this list of conditions and the following disclaimer.
+    2. Redistributions in binary form must reproduce the above copyright
+       notice, this list of conditions and the following disclaimer in the
+       documentation and/or other materials provided with the distribution.
+
+    THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+    ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+    IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+    ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+    FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+    DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+    OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+    HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+    LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+    OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+    SUCH DAMAGE.
+
+  Oniguruma LICENSE
+
+  >>>
+    Copyright (c) 2002-2009::  K.Kosako  <sndgk393 AT ybb DOT ne DOT jp>
+    All rights reserved.
+
+    Redistribution and use in source and binary forms, with or without
+    modification, are permitted provided that the following conditions
+    are met:
+    1. Redistributions of source code must retain the above copyright
+       notice, this list of conditions and the following disclaimer.
+    2. Redistributions in binary form must reproduce the above copyright
+       notice, this list of conditions and the following disclaimer in the
+       documentation and/or other materials provided with the distribution.
+
+    THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+    ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+    IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+    ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+    FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+    DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+    OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+    HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+    LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+    OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+    SUCH DAMAGE.
+
+  * https://github.com/k-takata/Onigmo/
+  * https://github.com/kkos/oniguruma
+  * https://svnweb.freebsd.org/ports/head/devel/oniguruma/
+
+    When this software is partly used or it is distributed with Ruby,
+    this of Ruby follows the license of Ruby.
+
+[enc/windows_1250.c]
+[enc/windows_1252.c]
+
+  >>>
+    Copyright (c) 2006-2007::  Byte      <byte AT mail DOT kna DOT ru>
+                               K.Kosako  <sndgk393 AT ybb DOT ne DOT jp>
+    All rights reserved.
+
+    Redistribution and use in source and binary forms, with or without
+    modification, are permitted provided that the following conditions
+    are met:
+    1. Redistributions of source code must retain the above copyright
+       notice, this list of conditions and the following disclaimer.
+    2. Redistributions in binary form must reproduce the above copyright
+       notice, this list of conditions and the following disclaimer in the
+       documentation and/or other materials provided with the distribution.
+
+    THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+    ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+    IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+    ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+    FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+    DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+    OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+    HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+    LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+    OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+    SUCH DAMAGE.
+
+[enc/cesu_8.c]
+[enc/windows_1253.c]
+[enc/windows_1254.c]
+[enc/windows_1257.c]
+
+  >>>
+    Copyright (c) 2002-2007::  K.Kosako  <sndgk393 AT ybb DOT ne DOT jp>
+    All rights reserved.
+
+    Redistribution and use in source and binary forms, with or without
+    modification, are permitted provided that the following conditions
+    are met:
+    1. Redistributions of source code must retain the above copyright
+       notice, this list of conditions and the following disclaimer.
+    2. Redistributions in binary form must reproduce the above copyright
+       notice, this list of conditions and the following disclaimer in the
+       documentation and/or other materials provided with the distribution.
+
+    THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+    ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+    IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+    ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+    FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+    DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+    OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+    HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+    LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+    OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+    SUCH DAMAGE.
+
+[enc/trans/GB/GB12345%UCS.src]
+[enc/trans/GB/UCS%GB12345.src]
+[enc/trans/GB/GB2312%UCS.src]
+[enc/trans/GB/UCS%GB2312.src]
+
+  These files have this explanatory texts.
+
+  >>>
+    This mapping data was created from files provided by Unicode, Inc.
+    (The Unicode Consortium). The files were used to create a product supporting
+    Unicode, as explicitly permitted in the files' copyright notices.
+    Please note that Unicode, Inc. never made any claims as to fitness of these
+    files for any particular purpose, and has ceased to publish the files many
+    years ago.
+
+[enc/trans/JIS/JISX0201-KANA%UCS.src]
+[enc/trans/JIS/JISX0208\@1990%UCS.src]
+[enc/trans/JIS/JISX0212%UCS.src]
+[enc/trans/JIS/UCS%JISX0201-KANA.src]
+[enc/trans/JIS/UCS%JISX0208@1990.src]
+[enc/trans/JIS/UCS%JISX0212.src]
+
+  These files are copyrighted as the following.
+
+  >>>
+    © 2015 Unicode®, Inc.
+
+    For terms of use, see http://www.unicode.org/terms_of_use.html
+
+[enc/trans/JIS/JISX0213-1%UCS@BMP.src]
+[enc/trans/JIS/JISX0213-1%UCS@SIP.src]
+[enc/trans/JIS/JISX0213-2%UCS@BMP.src]
+[enc/trans/JIS/JISX0213-2%UCS@SIP.src]
+
+  These files are copyrighted as the following.
+
+  >>>
+    Copyright (C) 2001:: earthian@tama.or.jp, All Rights Reserved.
+    Copyright (C) 2001:: I'O, All Rights Reserved.
+    Copyright (C) 2006:: Project X0213, All Rights Reserved.
+    You can use, modify, distribute this table freely.
+
+[enc/trans/JIS/UCS@BMP%JISX0213-1.src]
+[enc/trans/JIS/UCS@BMP%JISX0213-2.src]
+[enc/trans/JIS/UCS@SIP%JISX0213-1.src]
+[enc/trans/JIS/UCS@SIP%JISX0213-2.src]
+
+  These files are copyrighted as the following.
+
+  >>>
+    Copyright (C) 2001:: earthian@tama.or.jp, All Rights Reserved.
+    Copyright (C) 2001:: I'O, All Rights Reserved.
+    You can use, modify, distribute this table freely.
+
+[enc/trans/ucm/glibc-BIG5-2.3.3.ucm]
+[enc/trans/ucm/glibc-BIG5HKSCS-2.3.3.ucm]
+
+  >>>
+    Copyright (C) 2001-2005:: International Business Machines
+                              Corporation and others.  All Rights Reserved.
+
+[enc/trans/ucm/windows-950-2000.ucm]
+[enc/trans/ucm/windows-950_hkscs-2001.ucm]
+
+  >>>
+    Copyright (C) 2001-2002:: International Business Machines
+                              Corporation and others.  All Rights Reserved.
+
+
+[configure]
+
+  This file is free software.
+
+  >>>
+    Copyright (C) 1992-1996, 1998-2012:: Free Software Foundation, Inc.
+
+    This configure script is free software; the Free Software Foundation
+    gives unlimited permission to copy, distribute and modify it.
+
+[aclocal.m4]
+
+  This file is free software.
+
+  >>>
+    Copyright (C) 1996-2020:: Free Software Foundation, Inc.
+
+    This file is free software; the Free Software Foundation
+    gives unlimited permission to copy and/or distribute it,
+    with or without modifications, as long as this notice is preserved.
+
+[tool/config.guess]
+[tool/config.sub]
+
+  As long as you distribute these files with the file configure, they
+  are covered under the Ruby's license.
+
+  >>>
+    Copyright 1992-2018:: Free Software Foundation, Inc.
+
+    This file is free software; you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful, but
+    WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+    General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, see <https://www.gnu.org/licenses/>.
+
+    As a special exception to the GNU General Public License, if you
+    distribute this file as part of a program that contains a
+    configuration script generated by Autoconf, you may include it under
+    the same distribution terms that you use for the rest of that
+    program.  This Exception is an additional permission under section 7
+    of the GNU General Public License, version 3 ("GPLv3").
+
+[parse.c]
+[parse.h]
+
+  These files are licensed under the GPL, but are incorporated into Ruby and
+  redistributed under the terms of the Ruby license, as permitted by the
+  exception to the GPL below.
+
+  >>>
+    Copyright (C) 1984, 1989-1990, 2000-2015, 2018:: Free Software Foundation, Inc.
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+    As a special exception, you may create a larger work that contains
+    part or all of the Bison parser skeleton and distribute that work
+    under terms of your choice, so long as that work isn't itself a
+    parser generator using the skeleton or a modified version thereof
+    as a parser skeleton.  Alternatively, if you modify or redistribute
+    the parser skeleton itself, you may (at your option) remove this
+    special exception, which will cause the skeleton and the resulting
+    Bison output files to be licensed under the GNU General Public
+    License without this special exception.
+
+    This special exception was added by the Free Software Foundation in
+    version 2.2 of Bison.
+
+[missing/dtoa.c]
+
+  This file is under these licenses.
+
+  >>>
+    Copyright (c) 1991, 2000, 2001:: by Lucent Technologies.
+
+    Permission to use, copy, modify, and distribute this software for any
+    purpose without fee is hereby granted, provided that this entire notice
+    is included in all copies of any software which is or includes a copy
+    or modification of this software and in all copies of the supporting
+    documentation for such software.
+
+    THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR IMPLIED
+    WARRANTY.  IN PARTICULAR, NEITHER THE AUTHOR NOR LUCENT MAKES ANY
+    REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE MERCHANTABILITY
+    OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR PURPOSE.
+
+  >>>
+    Copyright (c) 2004-2008:: David Schultz <das@FreeBSD.ORG>
+                              All rights reserved.
+
+    Redistribution and use in source and binary forms, with or without
+    modification, are permitted provided that the following conditions
+    are met:
+    1. Redistributions of source code must retain the above copyright
+       notice, this list of conditions and the following disclaimer.
+    2. Redistributions in binary form must reproduce the above copyright
+       notice, this list of conditions and the following disclaimer in the
+       documentation and/or other materials provided with the distribution.
+
+    THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+    ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+    IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+    ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+    FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+    DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+    OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+    HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+    LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+    OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+    SUCH DAMAGE.
+
+[win32/win32.c]
+[include/ruby/win32.h]
+
+  You can apply the Artistic License to these files. (or GPL,
+  alternatively)
+
+  >>>
+    Copyright (c) 1993:: Intergraph Corporation
+
+    You may distribute under the terms of either the GNU General Public
+    License or the Artistic License, as specified in the perl README file.
+
+[missing/mt19937.c]
+
+  This file is under the new-style BSD license.
+
+  >>>
+    A C-program for MT19937, with initialization improved 2002/2/10.::
+    Coded by Takuji Nishimura and Makoto Matsumoto.  
+    This is a faster version by taking Shawn Cokus's optimization,
+    Matthe Bellew's simplification, Isaku Wada's real version.
+
+    Before using, initialize the state by using init_genrand(seed)
+    or init_by_array(init_key, key_length).
+
+    Copyright (C) 1997 - 2002:: Makoto Matsumoto and Takuji Nishimura,
+                                All rights reserved.
+
+    Redistribution and use in source and binary forms, with or without
+    modification, are permitted provided that the following conditions
+    are met:
+
+    1. Redistributions of source code must retain the above copyright
+       notice, this list of conditions and the following disclaimer.
+
+    2. Redistributions in binary form must reproduce the above copyright
+       notice, this list of conditions and the following disclaimer in the
+       documentation and/or other materials provided with the distribution.
+
+    3. The names of its contributors may not be used to endorse or promote
+       products derived from this software without specific prior written
+       permission.
+
+    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+    A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+    CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+    EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+    PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+    PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+    LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+    NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+    SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+
+    Any feedback is very welcome.
+    http://www.math.keio.ac.jp/matumoto/emt.html
+    email: matumoto@math.keio.ac.jp
+
+  The Wayback Machine url: http://web.archive.org/web/19990429082237/http://www.math.keio.ac.jp/matumoto/emt.html
+
+[missing/procstat_vm.c]
+
+  This file is under the new-style BSD license.
+
+  >>>
+    Copyright (c) 2007:: Robert N. M. Watson
+                         All rights reserved.
+
+    Redistribution and use in source and binary forms, with or without
+    modification, are permitted provided that the following conditions
+    are met:
+    1. Redistributions of source code must retain the above copyright
+       notice, this list of conditions and the following disclaimer.
+    2. Redistributions in binary form must reproduce the above copyright
+       notice, this list of conditions and the following disclaimer in the
+       documentation and/or other materials provided with the distribution.
+
+    THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+    ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+    IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+    ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+    FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+    DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+    OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+    HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+    LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+    OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+    SUCH DAMAGE.
+
+    $FreeBSD: head/usr.bin/procstat/procstat_vm.c 261780 2014-02-11 21:57:37Z jhb $
+
+[vsnprintf.c]
+
+  This file is under the {old-style BSD license}[rdoc-label:label-Old-style+BSD+license].
+
+  >>>
+    Copyright (c) 1990, 1993::
+    The Regents of the University of California.  All rights reserved.
+
+    This code is derived from software contributed to Berkeley by
+    Chris Torek.
+
+[st.c]
+[strftime.c]
+[include/ruby/st.h]
+[missing/acosh.c]
+[missing/alloca.c]
+[missing/dup2.c]
+[missing/erf.c]
+[missing/finite.c]
+[missing/hypot.c]
+[missing/isinf.c]
+[missing/isnan.c]
+[missing/lgamma_r.c]
+[missing/memcmp.c]
+[missing/memmove.c]
+[missing/strchr.c]
+[missing/strerror.c]
+[missing/strstr.c]
+[missing/tgamma.c]
+[ext/date/date_strftime.c]
+[ext/digest/sha1/sha1.c]
+[ext/digest/sha1/sha1.h]
+
+  These files are all under public domain.
+
+[missing/crypt.c]
+
+  This file is under the {old-style BSD license}[rdoc-label:label-Old-style+BSD+license].
+
+  >>>
+    Copyright (c) 1989, 1993::
+    The Regents of the University of California.  All rights reserved.
+
+    This code is derived from software contributed to Berkeley by
+    Tom Truscott.
+
+[missing/setproctitle.c]
+
+  This file is under the {old-style BSD license}[rdoc-label:label-Old-style+BSD+license].
+
+  >>>
+    Copyright 2003:: Damien Miller
+    Copyright (c) 1983, 1995-1997:: Eric P. Allman
+    Copyright (c) 1988, 1993::
+    The Regents of the University of California.  All rights reserved.
+
+[missing/strlcat.c]
+[missing/strlcpy.c]
+
+  These files are under an ISC-style license.
+
+  >>>
+    Copyright (c) 1998, 2015:: Todd C. Miller <Todd.Miller@courtesan.com>
+
+    Permission to use, copy, modify, and distribute this software for any
+    purpose with or without fee is hereby granted, provided that the above
+    copyright notice and this permission notice appear in all copies.
+
+    THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+    WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+    MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+    ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+    WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+    ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+
+[missing/langinfo.c]
+
+  This file is from http://www.cl.cam.ac.uk/~mgk25/ucs/langinfo.c.
+  Ruby uses a modified version. The file contains the following
+  author/copyright notice:
+
+  >>>
+    Markus.Kuhn@cl.cam.ac.uk -- 2002-03-11::
+    Permission to use, copy, modify, and distribute this software
+    for any purpose and without fee is hereby granted. The author
+    disclaims all warranties with regard to this software.
+
+[ext/digest/md5/md5.c]
+[ext/digest/md5/md5.h]
+
+  These files are under the following license.  Ruby uses modified
+  versions of them.
+
+  >>>
+    Copyright (C) 1999, 2000:: Aladdin Enterprises.  All rights reserved.
+
+    This software is provided 'as-is', without any express or implied
+    warranty.  In no event will the authors be held liable for any damages
+    arising from the use of this software.
+
+    Permission is granted to anyone to use this software for any purpose,
+    including commercial applications, and to alter it and redistribute it
+    freely, subject to the following restrictions:
+
+    1. The origin of this software must not be misrepresented; you must not
+       claim that you wrote the original software. If you use this software
+       in a product, an acknowledgment in the product documentation would be
+       appreciated but is not required.
+    2. Altered source versions must be plainly marked as such, and must not be
+       misrepresented as being the original software.
+    3. This notice may not be removed or altered from any source distribution.
+
+    L. Peter Deutsch
+    ghost@aladdin.com
+
+[ext/digest/rmd160/rmd160.c]
+[ext/digest/rmd160/rmd160.h]
+
+  These files have the following copyright information, and by the
+  author we are allowed to use it under the new-style BSD license.
+
+  >>>
+    AUTHOR::  Antoon Bosselaers, ESAT-COSIC
+              (Arranged for libc by Todd C. Miller)
+    DATE::    1 March 1996
+
+    Copyright (c):: Katholieke Universiteit Leuven
+    1996, All Rights Reserved
+
+[ext/digest/sha2/sha2.c]
+[ext/digest/sha2/sha2.h]
+
+  These files are under the new-style BSD license.
+
+  >>>
+    Copyright 2000:: Aaron D. Gifford.  All rights reserved.
+
+    Redistribution and use in source and binary forms, with or without
+    modification, are permitted provided that the following conditions
+    are met:
+    1. Redistributions of source code must retain the above copyright
+       notice, this list of conditions and the following disclaimer.
+    2. Redistributions in binary form must reproduce the above copyright
+       notice, this list of conditions and the following disclaimer in the
+       documentation and/or other materials provided with the distribution.
+    3. Neither the name of the copyright holder nor the names of contributors
+       may be used to endorse or promote products derived from this software
+       without specific prior written permission.
+
+    THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) AND CONTRIBUTOR(S) ``AS IS'' AND
+    ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+    IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+    ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR(S) OR CONTRIBUTOR(S) BE LIABLE
+    FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+    DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+    OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+    HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+    LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+    OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+    SUCH DAMAGE.
+
+[ext/json/generator/generator.c]
+
+  The file contains the following copyright notice.
+
+  >>>
+    Copyright 2001-2004:: Unicode, Inc.
+
+    Disclaimer::
+
+      This source code is provided as is by Unicode, Inc. No claims are
+      made as to fitness for any particular purpose. No warranties of any
+      kind are expressed or implied. The recipient agrees to determine
+      applicability of information provided. If this file has been
+      purchased on magnetic or optical media from Unicode, Inc., the
+      sole remedy for any claim will be exchange of defective media
+      within 90 days of receipt.
+
+    Limitations on Rights to Redistribute This Code::
+
+      Unicode, Inc. hereby grants the right to freely use the information
+      supplied in this file in the creation of products supporting the
+      Unicode Standard, and to make copies of this file in any form
+      for internal or external distribution as long as this notice
+      remains attached.
+
+[ext/nkf/nkf-utf8/config.h]
+[ext/nkf/nkf-utf8/nkf.c]
+[ext/nkf/nkf-utf8/utf8tbl.c]
+
+  These files are under the following license.  So to speak, it is
+  copyrighted semi-public-domain software.
+
+  >>>
+    Copyright (C) 1987:: Fujitsu LTD. (Itaru ICHIKAWA)
+
+    Everyone is permitted to do anything on this program
+    including copying, modifying, improving,
+    as long as you don't try to pretend that you wrote it.
+    i.e., the above copyright notice has to appear in all copies.
+    Binary distribution requires original version messages.
+    You don't have to ask before copying, redistribution or publishing.
+    THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE.
+
+[ext/psych]
+[test/psych]
+
+  The files under these directories are under the following license, except for
+  ext/psych/yaml.
+
+  >>>
+    Copyright 2009:: Aaron Patterson, et al.
+
+    Permission is hereby granted, free of charge, to any person obtaining a copy of
+    this software and associated documentation files (the 'Software'), to deal in
+    the Software without restriction, including without limitation the rights to
+    use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
+    of the Software, and to permit persons to whom the Software is furnished to do
+    so, subject to the following conditions:
+
+    The above copyright notice and this permission notice shall be included in all
+    copies or substantial portions of the Software.
+
+    THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+    SOFTWARE.
+
+[ext/psych/yaml]
+
+  The files under this directory are under the following license.
+
+  >>>
+    Copyright (c) 2006:: Kirill Simonov
+
+    Permission is hereby granted, free of charge, to any person obtaining a copy of
+    this software and associated documentation files (the "Software"), to deal in
+    the Software without restriction, including without limitation the rights to
+    use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
+    of the Software, and to permit persons to whom the Software is furnished to do
+    so, subject to the following conditions:
+
+    The above copyright notice and this permission notice shall be included in all
+    copies or substantial portions of the Software.
+
+    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+    SOFTWARE.
+
+[ext/pty/pty.c]
+
+  >>>
+    C) Copyright 1998:: by Akinori Ito.
+
+    This software may be redistributed freely for this purpose, in full
+    or in part, provided that this entire copyright notice is included
+    on any copies of this software and applications and derivations thereof.
+
+    This software is provided on an "as is" basis, without warranty of any
+    kind, either expressed or implied, as to any matter including, but not
+    limited to warranty of fitness of purpose, or merchantability, or
+    results obtained from use of this software.
+
+[ext/socket/addrinfo.h]
+[ext/socket/getaddrinfo.c]
+[ext/socket/getnameinfo.c]
+
+  These files are under the new-style BSD license.
+
+  >>>
+    Copyright (C) 1995, 1996, 1997, 1998, and 1999:: WIDE Project.
+    All rights reserved.
+
+    Redistribution and use in source and binary forms, with or without
+    modification, are permitted provided that the following conditions
+    are met:
+    1. Redistributions of source code must retain the above copyright
+       notice, this list of conditions and the following disclaimer.
+    2. Redistributions in binary form must reproduce the above copyright
+       notice, this list of conditions and the following disclaimer in the
+       documentation and/or other materials provided with the distribution.
+    3. Neither the name of the project nor the names of its contributors
+       may be used to endorse or promote products derived from this software
+       without specific prior written permission.
+
+    THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
+    ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+    IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+    ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
+    FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+    DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+    OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+    HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+    LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+    OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+    SUCH DAMAGE.
+
+[ext/win32ole/win32ole.c]
+
+  You can apply the Artistic License to this file. (or GPL,
+  alternatively)
+
+  >>>
+    (c) 1995:: Microsoft Corporation. All rights reserved.
+    Developed by ActiveWare Internet Corp., http://www.ActiveWare.com
+
+    Other modifications Copyright (c) 1997, 1998:: by Gurusamy Sarathy
+    <gsar@umich.edu> and Jan Dubois <jan.dubois@ibm.net>
+
+    You may distribute under the terms of either the GNU General Public
+    License or the Artistic License, as specified in the README file
+    of the Perl distribution.
+
+  The Wayback Machine url: http://web.archive.org/web/19970607104352/http://www.activeware.com:80/
+
+[lib/rdoc/generator/template/darkfish/css/fonts.css]
+
+  This file is licensed under the {SIL Open Font License}[http://scripts.sil.org/OFL].
+
+[spec/mspec]
+[spec/ruby]
+
+  The files under these directories are under the following license.
+
+  >>>
+    Copyright (c) 2008:: Engine Yard, Inc. All rights reserved.
+
+    Permission is hereby granted, free of charge, to any person
+    obtaining a copy of this software and associated documentation
+    files (the "Software"), to deal in the Software without
+    restriction, including without limitation the rights to use,
+    copy, modify, merge, publish, distribute, sublicense, and/or sell
+    copies of the Software, and to permit persons to whom the
+    Software is furnished to do so, subject to the following
+    conditions:
+
+    The above copyright notice and this permission notice shall be
+    included in all copies or substantial portions of the Software.
+
+    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+    EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
+    OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+    NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+    HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+    WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+    FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+    OTHER DEALINGS IN THE SOFTWARE.
+
+[lib/rubygems.rb]
+[lib/rubygems]
+[test/rubygems]
+
+  RubyGems is under the following license.
+
+  >>>
+    RubyGems is copyrighted free software by Chad Fowler, Rich Kilmer, Jim
+    Weirich and others.  You can redistribute it and/or modify it under
+    either the terms of the {MIT license}[rdoc-label:label-MIT+License], or the conditions
+    below:
+
+    1. You may make and give away verbatim copies of the source form of the
+       software without restriction, provided that you duplicate all of the
+       original copyright notices and associated disclaimers.
+
+    2. You may modify your copy of the software in any way, provided that
+       you do at least ONE of the following:
+
+       a. place your modifications in the Public Domain or otherwise
+          make them Freely Available, such as by posting said
+          modifications to Usenet or an equivalent medium, or by allowing
+          the author to include your modifications in the software.
+
+       b. use the modified software only within your corporation or
+          organization.
+
+       c. give non-standard executables non-standard names, with
+          instructions on where to get the original software distribution.
+
+       d. make other distribution arrangements with the author.
+
+    3. You may distribute the software in object code or executable
+       form, provided that you do at least ONE of the following:
+
+       a. distribute the executables and library files of the software,
+          together with instructions (in the manual page or equivalent)
+          on where to get the original distribution.
+
+       b. accompany the distribution with the machine-readable source of
+          the software.
+
+       c. give non-standard executables non-standard names, with
+          instructions on where to get the original software distribution.
+
+       d. make other distribution arrangements with the author.
+
+    4. You may modify and include the part of the software into any other
+       software (possibly commercial).
+
+    5. The scripts and library files supplied as input to or produced as
+       output from the software do not automatically fall under the
+       copyright of the software, but belong to whomever generated them,
+       and may be sold commercially, and may be aggregated with this
+       software.
+
+    6. THIS SOFTWARE IS PROVIDED "AS IS" AND WITHOUT ANY EXPRESS OR
+       IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
+       WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+       PURPOSE.
+
+[lib/bundler]
+[lib/bundler.rb]
+[lib/bundler.gemspec]
+[spec/bundler]
+[man/bundle-*,gemfile.*]
+
+  Bundler is under the following license.
+
+  >>>
+    Portions copyright (c) 2010:: Andre Arko
+    Portions copyright (c) 2009:: Engine Yard
+
+    {MIT License}[rdoc-label:label-MIT+License]
+
+[lib/did_you_mean]
+[lib/did_you_mean.rb]
+[test/did_you_mean]
+
+  did_you_mean is under the following license.
+
+  >>>
+    Copyright (c) 2014-2016 Yuki Nishijima
+
+    {MIT License}[rdoc-label:label-MIT+License]
+
+[benchmark/so_ackermann.rb]
+[benchmark/so_array.rb]
+[benchmark/so_binary_trees.rb]
+[benchmark/so_concatenate.rb]
+[benchmark/so_count_words.yml]
+[benchmark/so_exception.rb]
+[benchmark/so_fannkuch.rb]
+[benchmark/so_fasta.rb]
+[benchmark/so_k_nucleotide.yml]
+[benchmark/so_lists.rb]
+[benchmark/so_mandelbrot.rb]
+[benchmark/so_matrix.rb]
+[benchmark/so_meteor_contest.rb]
+[benchmark/so_nbody.rb]
+[benchmark/so_nested_loop.rb]
+[benchmark/so_nsieve.rb]
+[benchmark/so_nsieve_bits.rb]
+[benchmark/so_object.rb]
+[benchmark/so_partial_sums.rb]
+[benchmark/so_pidigits.rb]
+[benchmark/so_random.rb]
+[benchmark/so_reverse_complement.yml]
+[benchmark/so_sieve.rb]
+[benchmark/so_spectralnorm.rb]
+
+  These files are very old copy of then-called "The Great Computer Language
+  Shootout".  LEGAL SITUATION OF THESE FILES ARE UNCLEAR because the original
+  site has been lost.  Upstream diverged to delete several benchmarks listed
+  above.
+
+== MIT License
+>>>
+      Permission is hereby granted, free of charge, to any person obtaining
+      a copy of this software and associated documentation files (the
+      "Software"), to deal in the Software without restriction, including
+      without limitation the rights to use, copy, modify, merge, publish,
+      distribute, sublicense, and/or sell copies of the Software, and to
+      permit persons to whom the Software is furnished to do so, subject to
+      the following conditions:
+
+      The above copyright notice and this permission notice shall be
+      included in all copies or substantial portions of the Software.
+
+      THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+      EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+      MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+      NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+      LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+      OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+      WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+== Old-style BSD license
+>>>
+      Redistribution and use in source and binary forms, with or without
+      modification, are permitted provided that the following conditions
+      are met:
+      1. Redistributions of source code must retain the above copyright
+         notice, this list of conditions and the following disclaimer.
+      2. Redistributions in binary form must reproduce the above copyright
+         notice, this list of conditions and the following disclaimer in the
+         documentation and/or other materials provided with the distribution.
+      3. Neither the name of the University nor the names of its contributors
+         may be used to endorse or promote products derived from this software
+         without specific prior written permission.
+
+      THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+      ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+      IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+      ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+      FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+      DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+      OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+      HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+      LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+      OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+      SUCH DAMAGE.
+
+      IMPORTANT NOTE::
+
+      From ftp://ftp.cs.berkeley.edu/pub/4bsd/README.Impt.License.Change
+      paragraph 3 above is now null and void.
diff --git a/MANIFEST b/MANIFEST
deleted file mode 100644
index 8f8976bb98..0000000000
--- a/MANIFEST
+++ /dev/null
@@ -1,219 +0,0 @@
-COPYING
-ChangeLog
-MANIFEST
-Makefile.in
-README
-README.jp
-README.EXT
-README.EXT.jp
-ToDo
-array.c
-bignum.c
-class.c
-compar.c
-configure
-configure.bat
-configure.in
-config_h.dj
-config_s.dj
-config.guess
-config.sub
-defines.h
-dir.c
-dln.c
-dln.h
-dmyext.c
-enum.c
-env.h
-error.c
-eval.c
-file.c
-fnmatch.c
-fnmatch.h
-gc.c
-glob.c
-hash.c
-inits.c
-install-sh
-instruby.rb
-intern.h
-io.c
-keywords
-lex.c
-main.c
-marshal.c
-math.c
-mkconfig.rb
-node.h
-numeric.c
-object.c
-pack.c
-parse.c
-parse.y
-prec.c
-process.c
-random.c
-range.c
-re.c
-re.h
-regex.c
-regex.h
-ruby.1
-ruby.c
-ruby.h
-rubyio.h
-rubysig.h
-rubytest.rb
-signal.c
-sprintf.c
-st.c
-st.h
-string.c
-struct.c
-time.c
-top.sed
-util.h
-util.c
-variable.c
-version.c
-version.h
-beos/ruby.def.in
-ext/Setup
-ext/Setup.dj
-ext/Setup.nt
-ext/Setup.x68
-ext/aix_ld.rb
-ext/cygwin32_ld.rb
-ext/extmk.rb.in
-ext/extmk.rb.nt
-lib/English.rb
-lib/Env.rb
-lib/README
-lib/base64.rb
-lib/cgi-lib.rb
-lib/complex.rb
-lib/date.rb
-lib/date2.rb
-lib/debug.rb
-lib/delegate.rb
-lib/e2mmap.rb
-lib/eregex.rb
-lib/find.rb
-lib/final.rb
-lib/finalize.rb
-lib/ftplib.rb
-lib/ftools.rb
-lib/getopts.rb
-lib/getoptlong.rb
-lib/importenv.rb
-lib/jcode.rb
-lib/mailread.rb
-lib/mathn.rb
-lib/matrix.rb
-lib/mkmf.rb
-lib/monitor.rb
-lib/mutex_m.rb
-lib/observer.rb
-lib/open3.rb
-lib/ostruct.rb
-lib/parsearg.rb
-lib/parsedate.rb
-lib/ping.rb
-lib/profile.rb
-lib/pstore.rb
-lib/rational.rb
-lib/readbytes.rb
-lib/shellwords.rb
-lib/singleton.rb
-lib/sync.rb
-lib/telnet.rb
-lib/tempfile.rb
-lib/thread.rb
-lib/thwait.rb
-lib/timeout.rb
-lib/tracer.rb
-lib/weakref.rb
-misc/README
-misc/inf-ruby.el
-misc/ruby-mode.el
-misc/rubydb2x.el
-misc/rubydb3x.el
-missing/alloca.c
-missing/crypt.c
-missing/dir.h
-missing/dup2.c
-missing/file.h
-missing/flock.c
-missing/memcmp.c
-missing/memmove.c
-missing/mkdir.c
-missing/strcasecmp.c
-missing/strchr.c
-missing/strdup.c
-missing/strerror.c
-missing/strftime.c
-missing/strstr.c
-missing/strtol.c
-missing/strtoul.c
-missing/vsnprintf.c
-missing/x68.c
-sample/README
-sample/biorhythm.rb
-sample/cal.rb
-sample/cbreak.rb
-sample/clnt.rb
-sample/dbmtest.rb
-sample/dir.rb
-sample/eval.rb
-sample/export.rb
-sample/exyacc.rb
-sample/fact.rb
-sample/fib.awk
-sample/fib.pl
-sample/fib.py
-sample/fib.rb
-sample/fib.scm
-sample/freq.rb
-sample/from.rb
-sample/fullpath.rb
-sample/getopts.test
-sample/goodfriday.rb
-sample/less.rb
-sample/list.rb
-sample/list2.rb
-sample/list3.rb
-sample/mine.rb
-sample/mkproto.rb
-sample/mpart.rb
-sample/mrshtest.rb
-sample/observ.rb
-sample/occur.pl
-sample/occur.rb
-sample/occur2.rb
-sample/philos.rb
-sample/pi.rb
-sample/rename.rb
-sample/rbc.rb
-sample/rcs.awk
-sample/rcs.dat
-sample/rcs.rb
-sample/regx.rb
-sample/sieve.rb
-sample/svr.rb
-sample/test.rb
-sample/time.rb
-sample/trojan.rb
-sample/tsvr.rb
-sample/uumerge.rb
-win32/Makefile
-win32/config.h
-win32/ntsetup.bat
-win32/ruby.def
-win32/sdbm.c
-win32/sdbm.h
-win32/win32.c
-win32/win32.h
-x68/fconvert.c
-x68/select.c
-x68/_dtos18.c
-x68/_round.c
diff --git a/Makefile.in b/Makefile.in
deleted file mode 100644
index 25a0acacd3..0000000000
--- a/Makefile.in
+++ /dev/null
@@ -1,244 +0,0 @@
-SHELL = /bin/sh
-
-#### Start of system configuration section. ####
-
-MAJOR=	@MAJOR@
-MINOR=	@MINOR@
-TEENY=	@TEENY@
-
-RUBY_INSTALL_NAME=@RUBY_INSTALL_NAME@
-
-srcdir = @srcdir@
-VPATH = @srcdir@:@srcdir@/missing
-
-CC = @CC@
-YACC = @YACC@
-PURIFY =
-AUTOCONF = autoconf
-@SET_MAKE@
-
-prefix = @prefix@
-CFLAGS = @CFLAGS@ -I@srcdir@ -I@includedir@
-LDFLAGS = @STATIC@ $(CFLAGS) @LDFLAGS@
-EXTLIBS = 
-LIBS = @LIBS@ $(EXTLIBS)
-MISSING = @LIBOBJS@ @ALLOCA@
-LDSHARED = @LDSHARED@
-DLDFLAGS = @DLDFLAGS@
-SOLIBS = @SOLIBS@
-
-binsuffix = @binsuffix@
-
-#### End of system configuration section. ####
-
-LIBRUBY_A     = @LIBRUBY_A@
-LIBRUBY_SO    = @LIBRUBY_SO@
-LIBRUBY_ALIASES= @LIBRUBY_ALIASES@
-LIBRUBY	      = @LIBRUBY@
-LIBRUBYARG    = @LIBRUBYARG@
-
-EXTOBJS	      = 
-
-MAINOBJ	      = main.o
-
-OBJS	      = array.o \
-		bignum.o \
-		class.o \
-		compar.o \
-		dir.o \
-		dln.o \
-		enum.o \
-		error.o \
-		eval.o \
-		file.o \
-		fnmatch.o \
-		gc.o \
-		glob.o \
-		hash.o \
-		inits.o \
-		io.o \
-		marshal.o \
-		prec.o \
-		math.o \
-		numeric.o \
-		object.o \
-		pack.o \
-		parse.o \
-		process.o \
-		random.o \
-		range.o \
-		re.o \
-		regex.o \
-		ruby.o \
-		signal.o \
-		sprintf.o \
-		st.o \
-		string.o \
-		struct.o \
-		time.o \
-		util.o \
-		variable.o \
-		version.o \
-		$(MISSING)
-
-all:		miniruby$(binsuffix) rbconfig.rb
-		@./miniruby$(binsuffix) -Xext extmk.rb @EXTSTATIC@
-
-miniruby$(binsuffix):	$(LIBRUBY_A) $(MAINOBJ) dmyext.o
-		@rm -f $@
-		$(PURIFY) $(CC) $(LDFLAGS) $(MAINOBJ) dmyext.o $(LIBRUBY_A) $(LIBS) -o $@
-
-ruby$(binsuffix):     	$(LIBRUBY) $(MAINOBJ) $(EXTOBJS) 
-		@rm -f $@
-		$(PURIFY) $(CC) $(LDFLAGS) $(MAINOBJ) $(EXTOBJS) $(LIBRUBYARG) $(LIBS) -o $@
-
-$(LIBRUBY_A):	$(OBJS) dmyext.o
-		@AR@ rcu $@ $(OBJS) dmyext.o
-		@-@RANLIB@ $@ 2> /dev/null || true
-
-$(LIBRUBY_SO):	$(OBJS) dmyext.o
-		$(LDSHARED) $(DLDFLAGS) $(SOLIBS) $(OBJS) dmyext.o -o $@
-		@for alias in $(LIBRUBY_ALIASES); do \
-		  rm -f $$alias \
-		   && @LN_S@ $(LIBRUBY_SO) $$alias \
-		     && echo ln @LN_S@ $(LIBRUBY_SO) $$alias; \
-		done
-
-install:	rbconfig.rb
-		./miniruby$(binsuffix) $(srcdir)/instruby.rb $(DESTDIR)
-
-clean:;		@rm -f $(OBJS) $(LIBRUBY_A) $(LIBRUBY_SO) $(LIBRUBY_ALIASES) $(MAINOBJ) rbconfig.rb
-		@rm -f ext/extinit.c ext/extinit.o dmyext.o
-		@if test -f ./miniruby$(binsuffix); then \
-			./miniruby$(binsuffix) -Xext extmk.rb clean; \
-		fi
-
-distclean:	clean
-		@rm -f Makefile ext/extmk.rb config.h
-		@rm -f ext/config.cache config.cache config.log config.status
-		@rm -f parse.c *~ core *.core gmon.out y.tab.c y.output
-		@rm -f ruby$(binsuffix) miniruby$(binsuffix)
-
-realclean:	distclean
-		@rm -f lex.c
-
-test:		miniruby$(binsuffix)
-		@./miniruby$(binsuffix) $(srcdir)/rubytest.rb
-
-rbconfig.rb:	config.status miniruby$(binsuffix)
-		@./miniruby$(binsuffix) $(srcdir)/mkconfig.rb rbconfig.rb
-
-config.status:	$(srcdir)/configure
-		$(SHELL) ./config.status --recheck
-
-$(srcdir)/configure: $(srcdir)/configure.in
-		cd $(srcdir) && $(AUTOCONF)
-
-.c.o:
-	$(CC) $(CFLAGS) $(CPPFLAGS) -c $<
-
-lex.c: keywords
-	gperf -p -j1 -i 1 -g -o -t -N rb_reserved_word -k1,3,$$ @srcdir@/keywords > lex.c
-
-parse.c: parse.y
-	$(YACC) $<
-	mv -f y.tab.c parse.c
-
-alloca.o: @srcdir@/missing/alloca.c
-	$(CC) -I. $(CFLAGS) $(CPPFLAGS) -c @srcdir@/missing/alloca.c
-
-crypt.o: @srcdir@/missing/crypt.c
-	$(CC) -I. $(CFLAGS) $(CPPFLAGS) -c @srcdir@/missing/crypt.c
-
-dup2.o: @srcdir@/missing/dup2.c
-	$(CC) -I. $(CFLAGS) $(CPPFLAGS) -c @srcdir@/missing/dup2.c
-
-flock.o: @srcdir@/missing/flock.c
-	$(CC) -I. $(CFLAGS) $(CPPFLAGS) -c @srcdir@/missing/flock.c
-
-memcmp.o: @srcdir@/missing/memcmp.c
-	$(CC) $(CFLAGS) $(CPPFLAGS) -c @srcdir@/missing/memcmp.c
-
-memmove.o: @srcdir@/missing/memmove.c
-	$(CC) $(CFLAGS) $(CPPFLAGS) -c @srcdir@/missing/memmove.c
-
-mkdir.o: @srcdir@/missing/mkdir.c
-	$(CC) $(CFLAGS) $(CPPFLAGS) -c @srcdir@/missing/mkdir.c
-
-vsnprintf.o: @srcdir@/missing/vsnprintf.c
-	$(CC) $(CFLAGS) $(CPPFLAGS) -c @srcdir@/missing/vsnprintf.c
-
-strcasecmp.o: @srcdir@/missing/strcasecmp.c
-	$(CC) $(CFLAGS) $(CPPFLAGS) -c @srcdir@/missing/strcasecmp.c
-
-strchr.o: @srcdir@/missing/strchr.c
-	$(CC) $(CFLAGS) $(CPPFLAGS) -c @srcdir@/missing/strchr.c
-
-strdup.o: @srcdir@/missing/strdup.c
-	$(CC) $(CFLAGS) $(CPPFLAGS) -c @srcdir@/missing/strdup.c
-
-strerror.o: @srcdir@/missing/strerror.c
-	$(CC) $(CFLAGS) $(CPPFLAGS) -c @srcdir@/missing/strerror.c
-
-strftime.o: @srcdir@/missing/strftime.c
-	$(CC) -I. $(CFLAGS) $(CPPFLAGS) -c @srcdir@/missing/strftime.c
-
-strstr.o: @srcdir@/missing/strstr.c
-	$(CC) $(CFLAGS) $(CPPFLAGS) -c @srcdir@/missing/strstr.c
-
-strtol.o: @srcdir@/missing/strtol.c
-	$(CC) $(CFLAGS) $(CPPFLAGS) -c @srcdir@/missing/strtol.c
-
-strtoul.o: @srcdir@/missing/strtoul.c
-	$(CC) $(CFLAGS) $(CPPFLAGS) -c @srcdir@/missing/strtoul.c
-
-nt.o: @srcdir@/missing/nt.c
-	$(CC) $(CFLAGS) $(CPPFLAGS) -c @srcdir@/missing/nt.c
-
-x68.o: @srcdir@/missing/x68.c
-	$(CC) $(CFLAGS) $(CPPFLAGS) -c @srcdir@/missing/x68.c
-
-# Prevent GNU make v3 from overflowing arg limit on SysV.
-.NOEXPORT:
-###
-parse.o: parse.y ruby.h config.h defines.h intern.h env.h node.h st.h regex.h util.h lex.c
-###
-array.o: array.c ruby.h config.h defines.h intern.h
-bignum.o: bignum.c ruby.h config.h defines.h intern.h
-class.o: class.c ruby.h config.h defines.h intern.h node.h st.h
-compar.o: compar.c ruby.h config.h defines.h intern.h
-dir.o: dir.c ruby.h config.h defines.h intern.h
-dln.o: dln.c config.h defines.h dln.h
-dmyext.o: dmyext.c
-enum.o: enum.c ruby.h config.h defines.h intern.h
-error.o: error.c ruby.h config.h defines.h intern.h env.h
-eval.o: eval.c ruby.h config.h defines.h intern.h node.h env.h rubysig.h st.h dln.h
-file.o: file.c ruby.h config.h defines.h intern.h rubyio.h rubysig.h
-fnmatch.o: fnmatch.c config.h fnmatch.h
-gc.o: gc.c ruby.h config.h defines.h intern.h rubysig.h st.h node.h env.h re.h regex.h
-glob.o: config.h glob.c fnmatch.h
-hash.o: hash.c ruby.h config.h defines.h intern.h st.h rubysig.h
-inits.o: inits.c ruby.h config.h defines.h intern.h
-io.o: io.c ruby.h config.h defines.h intern.h rubyio.h rubysig.h
-main.o: main.c ruby.h config.h defines.h intern.h
-marshal.o: marshal.c ruby.h config.h defines.h intern.h rubyio.h st.h
-prec.o: prec.c ruby.h config.h defines.h intern.h
-math.o: math.c ruby.h config.h defines.h intern.h
-numeric.o: numeric.c ruby.h config.h defines.h intern.h
-object.o: object.c ruby.h config.h defines.h intern.h st.h
-pack.o: pack.c ruby.h config.h defines.h intern.h
-process.o: process.c ruby.h config.h defines.h intern.h rubysig.h st.h
-random.o: random.c ruby.h config.h defines.h intern.h
-range.o: range.c ruby.h config.h defines.h intern.h
-re.o: re.c ruby.h config.h defines.h intern.h re.h regex.h
-regex.o: regex.c config.h regex.h util.h
-ruby.o: ruby.c ruby.h config.h defines.h intern.h dln.h util.h
-signal.o: signal.c ruby.h config.h defines.h intern.h rubysig.h
-sprintf.o: sprintf.c ruby.h config.h defines.h intern.h
-st.o: st.c config.h st.h
-string.o: string.c ruby.h config.h defines.h intern.h re.h regex.h
-struct.o: struct.c ruby.h config.h defines.h intern.h
-time.o: time.c ruby.h config.h defines.h intern.h
-util.o: util.c ruby.h config.h defines.h intern.h util.h
-variable.o: variable.c ruby.h config.h defines.h intern.h env.h node.h st.h
-version.o: version.c ruby.h config.h defines.h intern.h version.h
diff --git a/NEWS.md b/NEWS.md
new file mode 100644
index 0000000000..2dcfacb6e2
--- /dev/null
+++ b/NEWS.md
@@ -0,0 +1,820 @@
+# NEWS for Ruby 3.0.0
+
+This document is a list of user visible feature changes
+since the **2.7.0** release, except for bug fixes.
+
+Note that each entry is kept so brief that no reason behind or reference
+information is supplied with.  For a full list of changes with all
+sufficient information, see the ChangeLog file or Redmine
+(e.g. `https://bugs.ruby-lang.org/issues/$FEATURE_OR_BUG_NUMBER`).
+
+## Language changes
+
+* Keyword arguments are now separated from positional arguments.
+  Code that resulted in deprecation warnings in Ruby 2.7 will now
+  result in ArgumentError or different behavior. [[Feature #14183]]
+
+* Procs accepting a single rest argument and keywords are no longer
+  subject to autosplatting.  This now matches the behavior of Procs
+  accepting a single rest argument and no keywords.
+  [[Feature #16166]]
+
+    ```ruby
+    pr = proc{|*a, **kw| [a, kw]}
+
+    pr.call([1])
+    # 2.7 => [[1], {}]
+    # 3.0 => [[[1]], {}]
+
+    pr.call([1, {a: 1}])
+    # 2.7 => [[1], {:a=>1}] # and deprecation warning
+    # 3.0 => [[[1, {:a=>1}]], {}]
+    ```
+
+* Arguments forwarding (`...`) now supports leading arguments.
+  [[Feature #16378]]
+
+    ```ruby
+    def method_missing(meth, ...)
+      send(:"do_#{meth}", ...)
+    end
+    ```
+
+* Pattern matching (`case/in`) is no longer experimental. [[Feature #17260]]
+
+* One-line pattern matching is redesigned.  [EXPERIMENTAL]
+
+    * `=>` is added. It can be used like a rightward assignment.
+      [[Feature #17260]]
+
+        ```ruby
+        0 => a
+        p a #=> 0
+
+        {b: 0, c: 1} => {b:}
+        p b #=> 0
+        ```
+
+    * `in` is changed to return `true` or `false`. [[Feature #17371]]
+
+        ```ruby
+        # version 3.0
+        0 in 1 #=> false
+
+        # version 2.7
+        0 in 1 #=> raise NoMatchingPatternError
+        ```
+
+* Find-pattern is added.  [EXPERIMENTAL]
+  [[Feature #16828]]
+
+    ```ruby
+    case ["a", 1, "b", "c", 2, "d", "e", "f", 3]
+    in [*pre, String => x, String => y, *post]
+      p pre  #=> ["a", 1]
+      p x    #=> "b"
+      p y    #=> "c"
+      p post #=> [2, "d", "e", "f", 3]
+    end
+    ```
+
+* Endless method definition is added.  [EXPERIMENTAL]
+  [[Feature #16746]]
+
+    ```ruby
+    def square(x) = x * x
+    ```
+
+* Interpolated String literals are no longer frozen when
+  `# frozen-string-literal: true` is used. [[Feature #17104]]
+
+* Magic comment `shareable_constant_value` added to freeze constants.
+  See {Magic Comments}[rdoc-ref:doc/syntax/comments.rdoc@Magic+Comments] for more details.
+  [[Feature #17273]]
+
+* A {static analysis}[rdoc-label:label-Static+analysis] foundation is
+  introduced.
+    * {RBS}[rdoc-label:label-RBS] is introduced. It is a type definition
+      language for Ruby programs.
+    * {TypeProf}[rdoc-label:label-TypeProf] is experimentally bundled. It is a
+      type analysis tool for Ruby programs.
+
+* Deprecation warnings are no longer shown by default (since Ruby 2.7.2).
+  Turn them on with `-W:deprecated` (or with `-w` to show other warnings too).
+  [[Feature #16345]]
+
+* $SAFE and $KCODE are now normal global variables with no special behavior.
+  C-API methods related to $SAFE have been removed.
+  [[Feature #16131]] [[Feature #17136]]
+
+* yield in singleton class definitions in methods is now a SyntaxError
+  instead of a warning. yield in a class definition outside of a method
+  is now a SyntaxError instead of a LocalJumpError.  [[Feature #15575]]
+
+* When a class variable is overtaken by the same definition in an
+  ancestor class/module, a RuntimeError is now raised (previously,
+  it only issued a warning in verbose mode).  Additionally, accessing a
+  class variable from the toplevel scope is now a RuntimeError.
+  [[Bug #14541]]
+
+* Assigning to a numbered parameter is now a SyntaxError instead of
+  a warning.
+
+## Command line options
+
+### `--help` option
+
+When the environment variable `RUBY_PAGER` or `PAGER` is present and has
+a non-empty value, and the standard input and output are tty, the `--help`
+option shows the help message via the pager designated by the value.
+[[Feature #16754]]
+
+### `--backtrace-limit` option
+
+The `--backtrace-limit` option limits the maximum length of a backtrace.
+[[Feature #8661]]
+
+## Core classes updates
+
+Outstanding ones only.
+
+* Array
+
+    * The following methods now return Array instances instead of
+      subclass instances when called on subclass instances:
+      [[Bug #6087]]
+
+        * Array#drop
+        * Array#drop_while
+        * Array#flatten
+        * Array#slice!
+        * Array#slice / Array#[]
+        * Array#take
+        * Array#take_while
+        * Array#uniq
+        * Array#*
+
+    * Can be sliced with Enumerator::ArithmeticSequence
+
+        ```ruby
+        dirty_data = ['--', 'data1', '--', 'data2', '--', 'data3']
+        dirty_data[(1..).step(2)] # take each second element
+        # => ["data1", "data2", "data3"]
+        ```
+
+* Binding
+
+    * Binding#eval when called with one argument will use "(eval)"
+      for `__FILE__` and 1 for `__LINE__` in the evaluated code.
+      [[Bug #4352]] [[Bug #17419]]
+
+* ConditionVariable
+
+    * ConditionVariable#wait may now invoke the `block`/`unblock` scheduler
+      hooks in a non-blocking context. [[Feature #16786]]
+
+* Dir
+
+    * Dir.glob and Dir.[] now sort the results by default, and
+      accept the `sort:` keyword option.  [[Feature #8709]]
+
+* ENV
+
+    * ENV.except has been added, which returns a hash excluding the
+      given keys and their values.  [[Feature #15822]]
+
+    * Windows: Read ENV names and values as UTF-8 encoded Strings
+      [[Feature #12650]]
+
+* Encoding
+
+    * Added new encoding IBM720.  [[Feature #16233]]
+
+    * Changed default for Encoding.default_external to UTF-8 on Windows
+      [[Feature #16604]]
+
+* Fiber
+
+    * Fiber.new(blocking: true/false) allows you to create non-blocking
+      execution contexts. [[Feature #16786]]
+
+    * Fiber#blocking? tells whether the fiber is non-blocking. [[Feature #16786]]
+
+    * Fiber#backtrace and Fiber#backtrace_locations provide per-fiber backtrace.
+      [[Feature #16815]]
+
+    * The limitation of Fiber#transfer is relaxed. [[Bug #17221]]
+
+* GC
+
+    * GC.auto_compact= and GC.auto_compact have been added to control
+      when compaction runs.  Setting `auto_compact=` to true will cause
+      compaction to occur during major collections.  At the moment,
+      compaction adds significant overhead to major collections, so please
+      test first!  [[Feature #17176]]
+
+* Hash
+
+    * Hash#transform_keys and Hash#transform_keys! now accept a hash that maps
+      keys to new keys.  [[Feature #16274]]
+
+    * Hash#except has been added, which returns a hash excluding the
+      given keys and their values.  [[Feature #15822]]
+
+* IO
+
+    * IO#nonblock? now defaults to `true`. [[Feature #16786]]
+
+    * IO#wait_readable, IO#wait_writable, IO#read, IO#write and other
+      related methods (e.g. IO#puts, IO#gets) may invoke the scheduler hook
+      `#io_wait(io, events, timeout)` in a non-blocking execution context.
+      [[Feature #16786]]
+
+* Kernel
+
+    * Kernel#clone when called with the `freeze: false` keyword will call
+      `#initialize_clone` with the `freeze: false` keyword.
+      [[Bug #14266]]
+
+    * Kernel#clone when called with the `freeze: true` keyword will call
+      `#initialize_clone` with the `freeze: true` keyword, and will
+      return a frozen copy even if the receiver is unfrozen.
+      [[Feature #16175]]
+
+    * Kernel#eval when called with two arguments will use "(eval)"
+      for `__FILE__` and 1 for `__LINE__` in the evaluated code.
+      [[Bug #4352]]
+
+    * Kernel#lambda now warns if called without a literal block.
+      [[Feature #15973]]
+
+    * Kernel.sleep invokes the scheduler hook `#kernel_sleep(...)` in a
+      non-blocking execution context. [[Feature #16786]]
+
+* Module
+
+    * Module#include and Module#prepend now affect classes and modules
+      that have already included or prepended the receiver, mirroring the
+      behavior if the arguments were included in the receiver before
+      the other modules and classes included or prepended the receiver.
+      [[Feature #9573]]
+
+        ```ruby
+        class C; end
+        module M1; end
+        module M2; end
+        C.include M1
+        M1.include M2
+        p C.ancestors #=> [C, M1, M2, Object, Kernel, BasicObject]
+        ```
+
+    * Module#public, Module#protected, Module#private, Module#public_class_method,
+      Module#private_class_method, toplevel "private" and "public" methods
+      now accept single array argument with a list of method names. [[Feature #17314]]
+
+    * Module#attr_accessor, Module#attr_reader, Module#attr_writer and Module#attr
+      methods now return an array of defined method names as symbols.
+      [[Feature #17314]]
+
+    * Module#alias_method now returns the defined alias as a symbol.
+      [[Feature #17314]]
+
+* Mutex
+
+    * `Mutex` is now acquired per-`Fiber` instead of per-`Thread`. This change
+      should be compatible for essentially all usages and avoids blocking when
+      using a scheduler. [[Feature #16792]]
+
+* Proc
+
+    * Proc#== and Proc#eql? are now defined and will return true for
+      separate Proc instances if the procs were created from the same block.
+      [[Feature #14267]]
+
+* Queue / SizedQueue
+
+    * Queue#pop, SizedQueue#push and related methods may now invoke the
+      `block`/`unblock` scheduler hooks in a non-blocking context.
+      [[Feature #16786]]
+
+* Ractor
+
+    * New class added to enable parallel execution. See rdoc-ref:ractor.md for
+      more details.
+
+* Random
+
+    * `Random::DEFAULT` now refers to the `Random` class instead of being a `Random` instance,
+      so it can work with `Ractor`.
+      [[Feature #17322]]
+
+    * `Random::DEFAULT` is deprecated since its value is now confusing and it is no longer global,
+      use `Kernel.rand`/`Random.rand` directly, or create a `Random` instance with `Random.new` instead.
+      [[Feature #17351]]
+
+
+* String
+
+    * The following methods now return or yield String instances
+      instead of subclass instances when called on subclass instances:
+      [[Bug #10845]]
+
+        * String#*
+        * String#capitalize
+        * String#center
+        * String#chomp
+        * String#chop
+        * String#delete
+        * String#delete_prefix
+        * String#delete_suffix
+        * String#downcase
+        * String#dump
+        * String#each_char
+        * String#each_grapheme_cluster
+        * String#each_line
+        * String#gsub
+        * String#ljust
+        * String#lstrip
+        * String#partition
+        * String#reverse
+        * String#rjust
+        * String#rpartition
+        * String#rstrip
+        * String#scrub
+        * String#slice!
+        * String#slice / String#[]
+        * String#split
+        * String#squeeze
+        * String#strip
+        * String#sub
+        * String#succ / String#next
+        * String#swapcase
+        * String#tr
+        * String#tr_s
+        * String#upcase
+
+* Symbol
+
+    * Symbol#to_proc now returns a lambda Proc.  [[Feature #16260]]
+
+    * Symbol#name has been added, which returns the name of the symbol
+      if it is named.  The returned string is frozen.  [[Feature #16150]]
+
+* Fiber
+
+    * Introduce Fiber.set_scheduler for intercepting blocking operations and
+      Fiber.scheduler for accessing the current scheduler. See
+      rdoc-ref:fiber.md for more details about what operations are supported and
+      how to implement the scheduler hooks. [[Feature #16786]]
+
+    * Fiber.blocking? tells whether the current execution context is
+      blocking. [[Feature #16786]]
+
+    * Thread#join invokes the scheduler hooks `block`/`unblock` in a
+      non-blocking execution context. [[Feature #16786]]
+
+* Thread
+
+    * Thread.ignore_deadlock accessor has been added for disabling the
+      default deadlock detection, allowing the use of signal handlers to
+      break deadlock. [[Bug #13768]]
+
+* Warning
+
+    * Warning#warn now supports a category keyword argument.
+      [[Feature #17122]]
+
+## Stdlib updates
+
+Outstanding ones only.
+
+* BigDecimal
+
+    * Update to BigDecimal 3.0.0
+
+    * This version is Ractor compatible.
+
+* Bundler
+
+    * Update to Bundler 2.2.3
+
+* CGI
+
+    * Update to 0.2.0
+
+    * This version is Ractor compatible.
+
+* CSV
+
+    * Update to CSV 3.1.9
+
+* Date
+
+    * Update to Date 3.1.1
+
+    * This version is Ractor compatible.
+
+* Digest
+
+    * Update to Digest 3.0.0
+
+    * This version is Ractor compatible.
+
+* Etc
+
+    * Update to Etc 1.2.0
+
+    * This version is Ractor compatible.
+
+* Fiddle
+
+    * Update to Fiddle 1.0.5
+
+* IRB
+
+    * Update to IRB 1.2.6
+
+* JSON
+
+    * Update to JSON 2.5.0
+
+    * This version is Ractor compatible.
+
+* Set
+
+    * Update to set 1.0.0
+
+    * SortedSet has been removed for dependency and performance reasons.
+
+    * Set#join is added as a shorthand for `.to_a.join`.
+
+    * Set#<=> is added.
+
+* Socket
+
+    * Add :connect_timeout to TCPSocket.new [[Feature #17187]]
+
+* Net::HTTP
+
+    * Net::HTTP#verify_hostname= and Net::HTTP#verify_hostname have been
+      added to skip hostname verification.  [[Feature #16555]]
+
+    * Net::HTTP.get, Net::HTTP.get_response, and Net::HTTP.get_print
+      can take the request headers as a Hash in the second argument when the
+      first argument is a URI.  [[Feature #16686]]
+
+* Net::SMTP
+
+    * Add SNI support.
+
+    * Net::SMTP.start arguments are keyword arguments.
+
+    * TLS should not check the host name by default.
+
+* OpenStruct
+
+    * Initialization is no longer lazy. [[Bug #12136]]
+
+    * Builtin methods can now be overridden safely. [[Bug #15409]]
+
+    * Implementation uses only methods ending with `!`.
+
+    * Ractor compatible.
+
+    * Improved support for YAML. [[Bug #8382]]
+
+    * Use officially discouraged. Read OpenStruct@Caveats section.
+
+* Pathname
+
+    * Ractor compatible.
+
+* Psych
+
+    * Update to Psych 3.3.0
+
+    * This version is Ractor compatible.
+
+* Reline
+
+    * Update to Reline 0.1.5
+
+* RubyGems
+
+    * Update to RubyGems 3.2.3
+
+* StringIO
+
+    * Update to StringIO 3.0.0
+
+    * This version is Ractor compatible.
+
+* StringScanner
+
+    * Update to StringScanner 3.0.0
+
+    * This version is Ractor compatible.
+
+## Compatibility issues
+
+Excluding feature bug fixes.
+
+* Regexp literals and all Range objects are frozen. [[Feature #8948]] [[Feature #16377]] [[Feature #15504]]
+
+    ```ruby
+    /foo/.frozen? #=> true
+    (42...).frozen? # => true
+    ```
+
+* EXPERIMENTAL: Hash#each consistently yields a 2-element array. [[Bug #12706]]
+
+    * Now `{ a: 1 }.each(&->(k, v) { })` raises an ArgumentError
+      due to lambda's arity check.
+
+* When writing to STDOUT redirected to a closed pipe, no broken pipe
+  error message will be shown now.  [[Feature #14413]]
+
+* `TRUE`/`FALSE`/`NIL` constants are no longer defined.
+
+* Integer#zero? overrides Numeric#zero? for optimization.  [[Misc #16961]]
+
+* Enumerable#grep and Enumerable#grep_v when passed a Regexp and no block no longer modify
+  Regexp.last_match. [[Bug #17030]]
+
+* Requiring 'open-uri' no longer redefines `Kernel#open`.
+  Call `URI.open` directly or `use URI#open` instead. [[Misc #15893]]
+
+* SortedSet has been removed for dependency and performance reasons.
+
+## Stdlib compatibility issues
+
+* Default gems
+
+    * The following libraries are promoted to default gems from stdlib.
+
+        * English
+        * abbrev
+        * base64
+        * drb
+        * debug
+        * erb
+        * find
+        * net-ftp
+        * net-http
+        * net-imap
+        * net-protocol
+        * open-uri
+        * optparse
+        * pp
+        * prettyprint
+        * resolv-replace
+        * resolv
+        * rinda
+        * set
+        * securerandom
+        * shellwords
+        * tempfile
+        * tmpdir
+        * time
+        * tsort
+        * un
+        * weakref
+
+    * The following extensions are promoted to default gems from stdlib.
+
+        * digest
+        * io-nonblock
+        * io-wait
+        * nkf
+        * pathname
+        * syslog
+        * win32ole
+
+* Bundled gems
+
+    * net-telnet and xmlrpc have been removed from the bundled gems.
+      If you are interested in maintaining them, please comment on
+      your plan to https://github.com/ruby/xmlrpc
+      or https://github.com/ruby/net-telnet.
+
+* SDBM has been removed from the Ruby standard library. [[Bug #8446]]
+
+    * The issues of sdbm will be handled at https://github.com/ruby/sdbm
+
+* WEBrick has been removed from the Ruby standard library. [[Feature #17303]]
+
+    * The issues of WEBrick will be handled at https://github.com/ruby/webrick
+
+## C API updates
+
+* C API functions related to $SAFE have been removed.
+  [[Feature #16131]]
+
+* C API header file `ruby/ruby.h` was split. [[GH-2991]]
+
+    This should have no impact on extension libraries,
+    but users might experience slow compilations.
+
+* Memory view interface [EXPERIMENTAL]
+
+    * The memory view interface is a C-API set to exchange a raw memory area,
+      such as a numeric array or a bitmap image, between extension libraries.
+      The extension libraries can share also the metadata of the memory area
+      that consists of the shape, the element format, and so on.
+      Using these kinds of metadata, the extension libraries can share even
+      a multidimensional array appropriately.
+      This feature is designed by referring to Python's buffer protocol.
+      [[Feature #13767]] [[Feature #14722]]
+
+* Ractor related C APIs are introduced (experimental) in "include/ruby/ractor.h".
+
+## Implementation improvements
+
+* New method cache mechanism for Ractor. [[Feature #16614]]
+
+    * Inline method caches pointed from ISeq can be accessed by multiple Ractors
+      in parallel and synchronization is needed even for method caches. However,
+      such synchronization can be overhead so introducing new inline method cache
+      mechanisms, (1) Disposable inline method cache (2) per-Class method cache
+      and (3) new invalidation mechanism. (1) can avoid per-method call
+      synchronization because it only uses atomic operations.
+      See the ticket for more details.
+
+* The number of hashes allocated when using a keyword splat in
+  a method call has been reduced to a maximum of 1, and passing
+  a keyword splat to a method that accepts specific keywords
+  does not allocate a hash.
+
+* `super` is optimized when the same type of method is called in the previous call
+  if it's not refinements or an attr reader or writer.
+
+### JIT
+
+* Performance improvements of JIT-ed code
+
+    * Microarchitectural optimizations
+
+        * Native functions shared by multiple methods are deduplicated on JIT compaction.
+
+        * Decrease code size of hot paths by some optimizations and partitioning cold paths.
+
+    * Instance variables
+
+        * Eliminate some redundant checks.
+
+        * Skip checking a class and a object multiple times in a method when possible.
+
+        * Optimize accesses in some core classes like Hash and their subclasses.
+
+    * Method inlining support for some C methods
+
+        * `Kernel`: `#class`, `#frozen?`
+
+        * `Integer`: `#-@`, `#~`, `#abs`, `#bit_length`, `#even?`, `#integer?`, `#magnitude`,
+          `#odd?`, `#ord`, `#to_i`, `#to_int`, `#zero?`
+
+        * `Struct`: reader methods for 10th or later members
+
+    * Constant references are inlined.
+
+    * Always generate appropriate code for `==`, `nil?`, and `!` calls depending on
+      a receiver class.
+
+    * Reduce the number of PC accesses on branches and method returns.
+
+    * Optimize C method calls a little.
+
+* Compilation process improvements
+
+    * It does not keep temporary files in /tmp anymore.
+
+    * Throttle GC and compaction of JIT-ed code.
+
+    * Avoid GC-ing JIT-ed code when not necessary.
+
+    * GC-ing JIT-ed code is executed in a background thread.
+
+    * Reduce the number of locks between Ruby and JIT threads.
+
+## Static analysis
+
+### RBS
+
+* RBS is a new language for type definition of Ruby programs.
+  It allows writing types of classes and modules with advanced
+  types including union types, overloading, generics, and
+  _interface types_ for duck typing.
+
+* Ruby ships with type definitions for core/stdlib classes.
+
+* `rbs` gem is bundled to load and process RBS files.
+
+### TypeProf
+
+* TypeProf is a type analysis tool for Ruby code based on abstract interpretation.
+
+    * It reads non-annotated Ruby code, tries inferring its type signature, and prints
+      the analysis result in RBS format.
+
+    * Though it supports only a subset of the Ruby language yet, we will continuously
+      improve the coverage of language features, analysis performance, and usability.
+
+```ruby
+# test.rb
+def foo(x)
+  if x > 10
+    x.to_s
+  else
+    nil
+  end
+end
+
+foo(42)
+```
+
+```
+$ typeprof test.rb
+# Classes
+class Object
+  def foo : (Integer) -> String?
+end
+```
+
+## Miscellaneous changes
+
+* Methods using `ruby2_keywords` will no longer keep empty keyword
+  splats, those are now removed just as they are for methods not
+  using `ruby2_keywords`.
+
+* When an exception is caught in the default handler, the error
+  message and backtrace are printed in order from the innermost.
+  [[Feature #8661]]
+
+* Accessing an uninitialized instance variable no longer emits a
+  warning in verbose mode. [[Feature #17055]]
+
+[Bug #4352]:      https://bugs.ruby-lang.org/issues/4352
+[Bug #6087]:      https://bugs.ruby-lang.org/issues/6087
+[Bug #8382]:      https://bugs.ruby-lang.org/issues/8382
+[Bug #8446]:      https://bugs.ruby-lang.org/issues/8446
+[Feature #8661]:  https://bugs.ruby-lang.org/issues/8661
+[Feature #8709]:  https://bugs.ruby-lang.org/issues/8709
+[Feature #8948]:  https://bugs.ruby-lang.org/issues/8948
+[Feature #9573]:  https://bugs.ruby-lang.org/issues/9573
+[Bug #10845]:     https://bugs.ruby-lang.org/issues/10845
+[Bug #12136]:     https://bugs.ruby-lang.org/issues/12136
+[Feature #12650]: https://bugs.ruby-lang.org/issues/12650
+[Bug #12706]:     https://bugs.ruby-lang.org/issues/12706
+[Feature #13767]: https://bugs.ruby-lang.org/issues/13767
+[Bug #13768]:     https://bugs.ruby-lang.org/issues/13768
+[Feature #14183]: https://bugs.ruby-lang.org/issues/14183
+[Bug #14266]:     https://bugs.ruby-lang.org/issues/14266
+[Feature #14267]: https://bugs.ruby-lang.org/issues/14267
+[Feature #14413]: https://bugs.ruby-lang.org/issues/14413
+[Bug #14541]:     https://bugs.ruby-lang.org/issues/14541
+[Feature #14722]: https://bugs.ruby-lang.org/issues/14722
+[Bug #15409]:     https://bugs.ruby-lang.org/issues/15409
+[Feature #15504]: https://bugs.ruby-lang.org/issues/15504
+[Feature #15575]: https://bugs.ruby-lang.org/issues/15575
+[Feature #15822]: https://bugs.ruby-lang.org/issues/15822
+[Misc #15893]:    https://bugs.ruby-lang.org/issues/15893
+[Feature #15921]: https://bugs.ruby-lang.org/issues/15921
+[Feature #15973]: https://bugs.ruby-lang.org/issues/15973
+[Feature #16131]: https://bugs.ruby-lang.org/issues/16131
+[Feature #16150]: https://bugs.ruby-lang.org/issues/16150
+[Feature #16166]: https://bugs.ruby-lang.org/issues/16166
+[Feature #16175]: https://bugs.ruby-lang.org/issues/16175
+[Feature #16233]: https://bugs.ruby-lang.org/issues/16233
+[Feature #16260]: https://bugs.ruby-lang.org/issues/16260
+[Feature #16274]: https://bugs.ruby-lang.org/issues/16274
+[Feature #16345]: https://bugs.ruby-lang.org/issues/16345
+[Feature #16377]: https://bugs.ruby-lang.org/issues/16377
+[Feature #16378]: https://bugs.ruby-lang.org/issues/16378
+[Feature #16555]: https://bugs.ruby-lang.org/issues/16555
+[Feature #16604]: https://bugs.ruby-lang.org/issues/16604
+[Feature #16614]: https://bugs.ruby-lang.org/issues/16614
+[Feature #16686]: https://bugs.ruby-lang.org/issues/16686
+[Feature #16746]: https://bugs.ruby-lang.org/issues/16746
+[Feature #16754]: https://bugs.ruby-lang.org/issues/16754
+[Feature #16786]: https://bugs.ruby-lang.org/issues/16786
+[Feature #16792]: https://bugs.ruby-lang.org/issues/16792
+[Feature #16815]: https://bugs.ruby-lang.org/issues/16815
+[Feature #16828]: https://bugs.ruby-lang.org/issues/16828
+[Misc #16961]:    https://bugs.ruby-lang.org/issues/16961
+[Bug #17030]:     https://bugs.ruby-lang.org/issues/17030
+[Feature #17055]: https://bugs.ruby-lang.org/issues/17055
+[Feature #17104]: https://bugs.ruby-lang.org/issues/17104
+[Feature #17122]: https://bugs.ruby-lang.org/issues/17122
+[Feature #17136]: https://bugs.ruby-lang.org/issues/17136
+[Feature #17176]: https://bugs.ruby-lang.org/issues/17176
+[Feature #17187]: https://bugs.ruby-lang.org/issues/17187
+[Bug #17221]:     https://bugs.ruby-lang.org/issues/17221
+[Feature #17260]: https://bugs.ruby-lang.org/issues/17260
+[Feature #17273]: https://bugs.ruby-lang.org/issues/17273
+[Feature #17303]: https://bugs.ruby-lang.org/issues/17303
+[Feature #17314]: https://bugs.ruby-lang.org/issues/17314
+[Feature #17322]: https://bugs.ruby-lang.org/issues/17322
+[Feature #17351]: https://bugs.ruby-lang.org/issues/17351
+[Feature #17371]: https://bugs.ruby-lang.org/issues/17371
+[Bug #17419]:     https://bugs.ruby-lang.org/issues/17419
+[GH-2991]:        https://github.com/ruby/ruby/pull/2991
diff --git a/README b/README
deleted file mode 100644
index dd93c592be..0000000000
--- a/README
+++ /dev/null
@@ -1,133 +0,0 @@
-* What's Ruby
-
-Ruby is the interpreted scripting language for quick and
-easy object-oriented programming.  It has many features to
-process text files and to do system management tasks (as in
-Perl).  It is simple, straight-forward, and extensible.
-
-* Features of Ruby
-
-  + Simple Syntax
-  + *Normal* Object-Oriented features(ex. class, method calls)
-  + *Advanced* Object-Oriented features(ex. Mix-in, Singleton-method)
-  + Operator Overloading
-  + Exception Handling
-  + Iterators and Closures
-  + Garbage Collection
-  + Dynamic Loading of Object files(on some architecture)
-  + Highly Portable(works on many UNIX machines, and on DOS,
-    Windows, Mac, BeOS etc.)
-
-* How to get Ruby
-
-The Ruby distribution can be found on
-
-  ftp://ftp.netlab.co.jp/pub/lang/ruby/
-
-* How to compile and install
-
-This is what you need to do to compile and install Ruby:
-
-  1. Run ./configure, which will generate config.h and Makefile.
-
-  2. Edit defines.h if you need.  Probably this step will not need.
-
-  3. Remove comment mark(#) before the module names from ext/Setup (or
-     add module names if not present), if you want to link modules
-     statically.
-
-     If you don't want to compile non static extension modules
-     (probably on architectures which does not allow dynamic loading),
-     remove comment mark from the line "#option nodynamic" in
-     ext/Setup.
-
-  4. Run make.
-
-  5. Optionally, run 'make test' to check whether the compiled Ruby
-     interpreter works well.  If you see the message "test succeeded",
-     your ruby works as it should (hopefully).
-
-  6. Run 'make install'
-
-     You may have to be a super user to install ruby.
-
-If you fail to compile ruby, please send the detailed error report with
-the error log and machine/OS type, to help others.
-
-* Copying
-
-Ruby is copyrighted free software by Yukihiro Matsumoto <matz@netlab.co.jp>.
-You can redistribute it and/or modify it under either the terms of the GPL
-(see COPYING file), or the conditions below:
-
-  1. You may make and give away verbatim copies of the source form of the
-     software without restriction, provided that you duplicate all of the
-     original copyright notices and associated disclaimers.
-
-  2. You may modify your copy of the software in any way, provided that
-     you do at least ONE of the following:
-
-       a) place your modifications in the Public Domain or otherwise
-          make them Freely Available, such as by posting said
-	  modifications to Usenet or an equivalent medium, or by allowing
-	  the author to include your modifications in the software.
-
-       b) use the modified software only within your corporation or
-          organization.
-
-       c) rename any non-standard executables so the names do not conflict
-	  with standard executables, which must also be provided.
-
-       d) make other distribution arrangements with the author.
-
-  3. You may distribute the software in object code or executable
-     form, provided that you do at least ONE of the following:
-
-       a) distribute the executables and library files of the software,
-	  together with instructions (in the manual page or equivalent)
-	  on where to get the original distribution.
-
-       b) accompany the distribution with the machine-readable source of
-	  the software.
-
-       c) give non-standard executables non-standard names, with
-          instructions on where to get the original software distribution.
-
-       d) make other distribution arrangements with the author.
-
-  4. You may modify and include the part of the software into any other
-     software (possibly commercial).  But some files in the distribution
-     are not written by the author, so that they are not under this terms.
-     They are gc.c(partly), utils.c(partly), regex.[ch], fnmatch.[ch],
-     glob.c, st.[ch] and some files under the ./missing directory.  See
-     each file for the copying condition.
-
-  5. The scripts and library files supplied as input to or produced as 
-     output from the software do not automatically fall under the
-     copyright of the software, but belong to whomever generated them, 
-     and may be sold commercially, and may be aggregated with this
-     software.
-
-  6. THIS SOFTWARE IS PROVIDED "AS IS" AND WITHOUT ANY EXPRESS OR
-     IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
-     WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
-     PURPOSE.
-
-* Ruby home-page
-
-The URL of the Ruby home-page is:
-
-   http://www.netlab.co.jp/ruby/
-
-* The Author
-
-Feel free to send comments and bug reports to the author.  Here is the 
-author's latest mail address:
-
-  matz@netlab.co.jp
-
--------------------------------------------------------
-created at: Thu Aug  3 11:57:36 JST 1995
-Local variables:
-mode: indented-text
-end:
diff --git a/README.EXT b/README.EXT
index 297b31b468..48b8d964c4 100644
--- a/README.EXT
+++ b/README.EXT
@@ -1,1017 +1 @@
-.\" README.EXT -  -*- Text -*- created at: Mon Aug  7 16:45:54 JST 1995
-
-This document explains how to make extention modules for Ruby.
-
-1��Basic knowledge
-
-In C, variables have types and data do not have types.  In contrast,
-Ruby variables do not have static type and data themselves have
-types.  So, data need to be converted across the languages.
-
-Data in Ruby represented C type `VALUE'.  Each VALUE data have its
-data-type.
-
-To retrieve an C data from the VALUE, you need to:
-
- (1) Identify VALUE's data type
- (2) Convert VALUE into C data
-
-Converting to wrong data type may cause serious promblems.
-
-
-1.1 Data-types
-
-Ruby interpreter has data-types as below:
-
-	T_NIL		nil
-	T_OBJECT	ordinaly object
-	T_CLASS		class
-	T_MODULE	module
-	T_FLOAT		floating point number
-	T_STRING	string
-	T_REGEXP	regular expression
-	T_ARRAY		array
-	T_FIXNUM	Fixnum(31bit integer)
-	T_HASH		assosiative array
-	T_STRUCT	(Ruby) structure
-	T_BIGNUM	multi precision integer
-	T_TRUE		true
-	T_FALSE		false
-	T_DATA		data
-
-Otherwise, there are several other types used internally:
-
-	T_ICLASS
-	T_MATCH
-	T_VARMAP
-	T_SCOPE
-	T_NODE
-
-Most of the types are represented by C structures.
-
-1.2 Check Data Type of the VALUE
-
-The macro TYPE() defined in ruby.h shows data-type of the VALUE.
-TYPE() returns the constant number T_XXXX described above.  To handle
-data-types, the code will be like:
-
-  switch (TYPE(obj)) {
-    case T_FIXNUM:
-      /* process Fixnum */
-      break;
-    case T_STRING:
-      /* process String */
-      break;
-    case T_ARRAY:
-      /* process Array */
-      break;
-    default:
-      /* raise exception */
-      Fail("not valid value");
-      break;
-  }
-
-There is the data-type check function.
-
-  void Check_Type(VALUE value, int type)
-
-It raises an exception, if the VALUE does not have the type specified.
-
-There are faster check-macros for fixnums and nil.
-
-  FIXNUM_P(obj)
-  NIL_P(obj)
-
-1.3 Convert VALUE into C data
-
-The data for type T_NIL, T_FALSE, T_TRUE are nil, true, false
-respectively.  They are singletons for the data type.
-
-The T_FIXNUM data is the 31bit length fixed integer (63bit length on
-some machines), which can be conver to the C integer by using
-FIX2INT() macro.  There also be NUM2INT() which converts any Ruby
-numbers into C integer.  The NUM2INT() macro includes type check, so
-the exception will be raised if conversion failed.
-
-Other data types have corresponding C structures, e.g. struct RArray
-for T_ARRAY etc.  VALUE of the type which has corresponding structure
-can be cast to retrieve the pointer to the struct.  The casting macro
-RXXXX for each data type like RARRAY(obj).  see "ruby.h".
-
-For example, `RSTRING(size)->len' is the way to get the size of the
-Ruby String object.  The allocated region can be accessed by
-`RSTRING(str)->ptr'.  For arrays, `RARRAY(ary)->len' and
-`RARRAY(ary)->ptr' respectively.
-
-Notice: Do not change the value of the structure directly, unless you
-are responsible about the result.  It will be the cause of interesting
-bugs.
-
-1.4 Convert C data into VALUE
-
-VALUE�μºݤι�¤��
-
-  * FIXNUM�ξ��
-
-    1bit�����եȤ��ơ�LSB��Ω�Ƥ롥
-
-  * ����¾�Υݥ��󥿤ξ��
-
-    ���Τޤ�VALUE�˥��㥹�Ȥ��롥
-
-�ȤʤäƤ��ޤ�����äơ�LSB������å������VALUE��FIXNUM����
-�����狼��櫓�Ǥ�(�ݥ��󥿤�LSB��Ω�äƤ��ʤ����Ȥ��ꤷ��
-����)��
-
-�Ǥ����顤FIXNUM�ʳ���Ruby�Υ��֥������Ȥι�¤�Τ�ñ��VALUE
-�˥��㥹�Ȥ��������VALUE���Ѵ�����ޤ�����������Ǥ�դι�¤
-�Τ�VALUE�˥��㥹�Ƚ����櫓�ǤϤ���ޤ��󡥥��㥹�Ȥ����
-��Ruby���ΤäƤ��빽¤��(ruby.h���������Ƥ���struct RXxxx
-�Τ��)�����ˤ��Ƥ����Ƥ���������
-
-To convert C numbers to Ruby value, use these macros.
-
-  INT2FIX()	for intergers within 31bits.
-  INT2NUM()	for arbitrary sized integer.
-
-INT2NUM() converts integers into Bignums, if it is out of FIXNUM
-range, but bit slower.
-
-1.5 Manipulate Ruby data
-
-As I already told, it is not recommended to modify object's internal
-structure.  To manipulate objects, use functions supplied by Ruby
-interpreter.  Useful functions are listed below (not all):
-
- String funtions
-
-  rb_str_new(char *ptr, int len)
-
-    Creates a new Ruby string.
-
-  rb_str_new2(char *ptr)
-
-    Creates a new Ruby string from C string.  This is equivalent to
-    rb_str_new(ptr, strlen(ptr)).
-
-  rb_str_cat(VALUE str, char *ptr, int len)
-
-    Appends len bytes data from ptr to the Ruby string.
-
- Array functions
-
-  rb_ary_new()
-
-    Creates an array with no element.
-
-  rb_ary_new2(int len)
-
-    Creates an array with no element, with allocating internal buffer
-    for len elements.
-
-  rb_ary_new3(int n, ...)
-
-    Creates an n-elements array from arguments.
-
-  rb_ary_new4(int n, VALUE *elts)
-
-    Creates an n-elements array from C array.
-
-  rb_ary_push(VALUE ary, VALUE val)
-  rb_ary_pop(VALUE ary)
-  rb_ary_shift(VALUE ary)
-  rb_ary_unshift(VALUE ary, VALUE val)
-  rb_ary_entry(VALUE ary, int idx)
-
-    Array operations.  The first argument to each functions must be an 
-    array.  They may dump core if other types given.
-
-2. Extend Ruby with C
-
-����Ū��Ruby�ǽ񤱤뤳�Ȥ�C�Ǥ�񤱤ޤ���Ruby���Τ�Τ�C�ǵ�
-�Ҥ���Ƥ����Ǥ����顤�����Ȥ����������ʤ�Ǥ����ɡ�������
-��Ruby�γ�ĥ�˻Ȥ����Ȥ�¿����������ͽ¬����뵡ǽ���濴�˾�
-�𤷤ޤ���
-
-2.1 Add new features to Ruby
-
-You can add new features (classes, methods, etc.) to the Ruby
-interpreter.  Ruby provides the API to define things below:
-
- * Classes, Modules
- * Methods, Singleton Methods
- * Constants
-
-2.1.1 Class/module definition
-
-To define class or module, use functions below:
-
-  VALUE rb_define_class(char *name, VALUE super)
-  VALUE rb_define_module(char *name)
-
-These functions return the newly created class ot module.  You may
-want to save this reference into the variable to use later.
-
-2.1.2 Method/singleton method definition
-
-To define methods or singleton methods, use functions below:
-
-  void rb_define_method(VALUE class, char *name, 
-		        VALUE (*func)(), int argc)
-
-  void rb_define_singleton_method(VALUE object, char *name, 
-			          VALUE (*func)(), int argc)
-
-The `argc' represents the number of the arguments to the C function,
-which must be less than 17.  But I believe you don't need that much. :-)
-
-If `argc' is negative, it specifies calling sequence, not number of
-the arguments.  
-
-If argc is -1, the function will be called like:
-
-  VALUE func(int argc, VALUE *argv, VALUE obj)
-
-where argc is the actual number of arguments, argv is the C array of
-the arguments, and obj is the receiver.
-
-if argc is -2, the arguments are passed in Ruby array. The function
-will be called like:
-
-  VALUE func(VALUE obj, VALUE args)
-
-where obj is the receiver, and args is the Ruby array containing
-actual arguments.
-
-There're two more functions to define method.  One is to define
-private method:
-
-  void rb_define_private_method(VALUE class, char *name, 
-			        VALUE (*func)(), int argc)
-
-The other is to define module function, which is private AND singleton
-method of the module.  For example, sqrt is the module function
-defined in Math module.  It can be call in the form like:
-
-  Math.sqrt(4)
-
-or
-
-  include Math
-  sqrt(4)
-
-To define module function
-
-  void rb_define_module_function(VALUE module, char *name, 
-				 VALUE (*func)(), int argc)
-
-Oh, in addition, function-like method, which is private method defined
-in Kernel module, can be defined using:
-
-  void rb_define_global_function(char *name, VALUE (*func)(), int argc)
-
-
-2.1.3 Constant definition
-
-We have 2 functions to define constants:
-
-  void rb_define_const(VALUE class, char *name, VALUE val)
-  void rb_define_global_const(char *name, VALUE val)
-
-The former is to define constant under specified class/module.  The
-latter is to define global constant.
-
-2.2 Use Ruby features from C
-
-There are several ways to invoke Ruby's features from C code.
-
-2.2.1 Evaluate Ruby Program in String
-
-Easiest way to call Ruby's function from C program is to evaluate the
-string as Ruby program.  This function will do the job.
-
-  VALUE rb_eval_string(char *str)
-
-Evaluation is done under current context, thus current local variables
-of the innermost method (which is defined by Ruby) can be accessed.
-
-2.2.2 ID or Symbol
-
-You can invoke methods directly, without parsing the string.  First I
-need to explain about symbols (which data type is ID).  ID is the
-integer number to represent Ruby's identifiers such as variable names.
-It can be accessed from Ruby in the form like:
-
- :Identifier
-
-You can get the symbol value from string within C code, by using
-
-  rb_intern(char *name)
-
-In addition, the symbols for one character operators (e.g +) is the
-code for that character.
-
-2.2.3 Invoke Ruby method from C
-
-To invoke methods directly, you can use the function below
-
-  VALUE rb_funcall(VALUE recv, ID mid, int argc, ...)
-
-This function invokes the method of the recv, which name is specified
-by the symbol mid.
-
-2.2.4 Accessing the variables and constants
-
-You can access class variables, and instance variables using access
-functions.  Also, global variables can be shared between both worlds.
-There's no way to access Ruby's local variables.
-
-The functions to access/modify instance variables are below:
-
-  VALUE rb_ivar_get(VALUE obj, ID id)
-  VALUE rb_ivar_set(VALUE obj, ID id, VALUE val)
-
-id must be the symbol, which can be retrieved by rb_intern().
-
-To access the constants of the class/module:
-
-  VALUE rb_const_get(VALUE obj, ID id)
-
-See 2.1.3 for defining new constant.
-
-3. Informatin sharing between Ruby and C
-
-3.1 Ruby constant that C can be accessed from C
-
-Following Ruby constants can be referred from C.
-
-  Qtrue
-  Qfalse
-
-Boolean values.  Qfalse is false in the C also (i.e. 0).
-
-  Qnil
-
-Ruby nil in C scope.
-
-3.2 Global variables shared between C and Ruby
-
-C��Ruby������ѿ���Ȥäƾ����ͭ�Ǥ��ޤ�����ͭ�Ǥ������
-�ѿ��ˤϤ����Ĥ��μ��ब����ޤ������Τʤ��Ǥ�äȤ��ɤ��Ȥ�
-���Ȼפ���Τ�rb_define_variable()�Ǥ���
-
-  void rb_define_variable(char *name, VALUE *var)
-
-This function defines the variable which is shared by the both world.
-The value of the global variable pointerd by `var', can be accessed
-through Ruby's global variable named `name'.
-
-You can define read-only (from Ruby, of course) variable by the
-function below.
-
-  void rb_define_readonly_variable(char *name, VALUE *var)
-
-������ѿ���¾��hook��Ĥ�������ѿ�������Ǥ��ޤ���hook�դ�
-������ѿ��ϰʲ��δؿ����Ѥ���������ޤ���hook�դ�����ѿ���
-�ͤλ��Ȥ������hook�ǹԤ�ɬ�פ�����ޤ���
-
-  void rb_define_hooked_variable(char *name, VALUE *var,
-				 VALUE (*getter)(), VALUE (*setter)())
-
-���δؿ���C�δؿ��ˤ�ä�hook�ΤĤ���줿����ѿ����������
-�����ѿ������Ȥ��줿���ˤϴؿ�getter�����ѿ����ͤ����åȤ���
-�����ˤϴؿ�setter���ƤФ�롥hook����ꤷ�ʤ�����getter��
-setter��0����ꤷ�ޤ���
-
-# getter��setter��0�ʤ��rb_define_variable()��Ʊ���ˤʤ롥
-
-���줫�顤C�δؿ��ˤ�äƼ¸������Ruby������ѿ����������
-�ؿ�������ޤ���
-
-  void rb_define_virtual_variable(char *name,
-				  VALUE (*getter)(), VALUE (*setter)())
-
-���δؿ��ˤ�ä�������줿Ruby������ѿ������Ȥ��줿���ˤ�
-getter�����ѿ����ͤ����åȤ��줿���ˤ�setter���ƤФ�ޤ���
-
-The prototypes of the getter and setter functions are as following:
-
-  (*getter)(ID id, void *data, struct global_entry* entry);
-  (*setter)(VALUE val, ID id, void *data, struct global_entry* entry);
-
-3.3 Encapsulate C data into Ruby object
-
-C��������������줿�ǡ���(��¤��)��Ruby�Υ��֥������ȤȤ���
-��갷��������礬���ꤨ�ޤ������Τ褦�ʾ��ˤϡ�Data�Ȥ���
-Ruby���֥������Ȥ�C�ι�¤��(�ؤΥݥ���)�򤯤�ळ�Ȥ�Ruby
-���֥������ȤȤ��Ƽ�갷����褦�ˤʤ�ޤ���
-
-To wrapping and objectify the C pointer, use Data_Wrap_Struct().
-
-  Data_Wrap_Struct(class,mark,free,ptr)
-
-Data_Wrap_Struct() returns a created Data object.
-
-class�Ϥ���Data���֥������ȤΥ��饹�Ǥ���ptr�ϥ��ץ��벽����
-C�ι�¤�ΤؤΥݥ��󥿤Ǥ���mark�Ϥ��ι�¤�Τ�Ruby�Υ��֥���
-���Ȥؤλ��Ȥ�������˻Ȥ��ؿ��Ǥ������Τ褦�ʻ��Ȥ�ޤޤʤ�
-���ˤ�0����ꤷ�ޤ���
-
-# ���Τ褦�ʻ��Ȥϴ�����ޤ���
-
-free�Ϥ��ι�¤�Τ��⤦���פˤʤä����˸ƤФ��ؿ��Ǥ�������
-�ؿ��������١������쥯������ƤФ�ޤ���
-
-C�ι�¤�Τγ�����Data���֥������Ȥ�������Ʊ���˹Ԥ��ޥ�����
-���ưʲ��Τ�Τ��󶡤���Ƥ��ޤ���
-
-  Data_Make_Struct(class, type, mark, free, sval)
-
-This macro returns an allocated Data object, wrapping the pointer to
-the structure, which is also allocated.
-
-Arguments, class, mark, free, works like thier counterpart of
-Data_Wrap_Struct().  The pointer to allocated structure will be
-assigned to sval, which should be the pointer to the type specified.
-
-To retrieve the C pointer from the Data object, use the macro
-Data_Get_Struct().
-
-  Data_Get_Struct(obj, type, sval)
-
-The pointer to the structure will be assigned to the variable sval.
-
-See example below for detail. 
-
-4��Example - Create dbm module
-
-�����ޤǤ������ǤȤꤢ������ĥ�饤�֥��Ϻ���Ϥ��Ǥ���
-Ruby��ext�ǥ��쥯�ȥ�ˤ��Ǥ˴ޤޤ�Ƥ���dbm�⥸�塼������
-�����ʳ�Ū���������ޤ���
-
-(1) make the directory
-
-  % mkdir ext/dbm
-
-Make a directory for the extension library under ext directory.
-
-(2) create MANIFEST file
-
-  % cd ext/dbm
-  % touch MANIFEST
-
-There should be MANIFEST file in the directory for the extension
-library.  Make empty file now.
-
-(3) design the library
-
-You need to design the library features, before making it.
-
-(4) write C code.
-
-��ĥ�饤�֥�����ΤȤʤ�C����Υ�������񤭤ޤ���C����Υ���
-�����ҤȤĤλ��ˤϡ֥⥸�塼��̾.c�פ����֤��ɤ��Ǥ��礦��C
-����Υ�������ʣ���ξ��ˤϵդˡ֥⥸�塼��̾.c�פȤ����ե�
-����̾���򤱤�ɬ�פ�����ޤ������֥������ȥե�����ȥ⥸�塼
-�������������Ū�����������֥⥸�塼��̾.o�פȤ����ե�����
-�Ȥ����ͤ��뤫��Ǥ���
-
-Ruby�ϳ�ĥ�饤�֥�������ɤ�����ˡ�Init_�⥸�塼��̾�פ�
-�����ؿ���ưŪ�˼¹Ԥ��ޤ���dbm�⥸�塼��ξ���Init_dbm��
-�Ǥ������δؿ�����ǥ��饹���⥸�塼�롤�᥽�åɡ�����ʤɤ�
-�����Ԥ��ޤ���dbm.c����������Ѥ��ޤ���
-
---
-Init_dbm()
-{
-    /* define DBM class */
-    cDBM = rb_define_class("DBM", rb_cObject);
-    /* DBM includes Enumerate module */
-    rb_include_module(cDBM, rb_mEnumerable);
-
-    /* DBM has class method open(): arguments are received as C array */
-    rb_define_singleton_method(cDBM, "open", fdbm_s_open, -1);
-
-    /* DBM instance method close(): no args */
-    rb_define_method(cDBM, "close", fdbm_close, 0);
-    /* DBM instance method []: 1 argument */
-    rb_define_method(cDBM, "[]", fdbm_fetch, 1);
-		:
-
-}
---
-
-DBM�⥸�塼���dbm�Υǡ������б����륪�֥������Ȥˤʤ�Ϥ���
-�����顤C��������dbm��Ruby�������˼�����ɬ�פ�����ޤ���
-
-
-dbm.c�Ǥ�Data_Make_Struct��ʲ��Τ褦�˻ȤäƤ��ޤ���
-
---
-struct dbmdata {
-    int  di_size;
-    DBM *di_dbm;
-};
-
-
-obj = Data_Make_Struct(class,struct dbmdata,0,free_dbm,dbmp);
---
-
-�����Ǥ�dbmstruct��¤�ΤؤΥݥ��󥿤�Data�˥��ץ��벽���Ƥ�
-�ޤ���DBM*��ľ�ܥ��ץ��벽���ʤ��Τ�close()�������ν������
-���ƤΤ��ȤǤ���
-
-Data���֥������Ȥ���dbmstruct��¤�ΤΥݥ��󥿤���Ф�����
-�˰ʲ��Υޥ�����ȤäƤ��ޤ���
-
---
-#define GetDBM(obj, dbmp) {\
-    Data_Get_Struct(obj, struct dbmdata, dbmp);\
-    if (dbmp->di_dbm == 0) closed_dbm();\
-}
---
-
-����ä�ʣ���ʥޥ����Ǥ������פ����dbmdata��¤�ΤΥݥ���
-�μ��Ф��ȡ�close����Ƥ��뤫�ɤ����Υ����å���ޤȤ�Ƥ�
-������Ǥ���
-
-DBM���饹�ˤϤ�������᥽�åɤ�����ޤ�����ʬ�ह���3�����
-�����μ�����������ޤ����ҤȤĤϰ����ο�������Τ�Τǡ����
-���Ƥ�delete�᥽�åɤ�����ޤ���delete�᥽�åɤ�������Ƥ���
-fdbm_delete()�Ϥ��Τ褦�ˤʤäƤ��ޤ���
-
---
-static VALUE
-fdbm_delete(obj, keystr)
-    VALUE obj, keystr;
-{
-	:
-}
---
-
-�����ο�������Υ����פ���1������self����2�����ʹߤ��᥽�å�
-�ΰ����Ȥʤ�ޤ���
-
-�����ο�������Τ�Τ�C������Ǽ������Τ�Ruby������Ǽ���
-���ΤȤ�����ޤ���dbm�⥸�塼�����ǡ�C������Ǽ�������
-��DBM�Υ��饹�᥽�åɤǤ���open()�Ǥ��������������Ƥ����
-��fdbm_s_open()�Ϥ����ʤäƤ��ޤ���
-
---
-static VALUE
-fdbm_s_open(argc, argv, class)
-    int argc;
-    VALUE *argv;
-    VALUE class;
-{
-	:
-    if (rb_scan_args(argc, argv, "11", &file, &vmode) == 1) {
-	mode = 0666;		/* default value */
-    }
-	:
-}
---
-
-���Υ����פδؿ�����1������Ϳ����줿�����ο�����2������Ϳ��
-��줿���������äƤ�������ˤʤ�ޤ���self����3�����Ȥ���Ϳ
-�����ޤ���
-
-���������Ϳ����줿��������Ϥ��뤿��δؿ���open()�Ǥ�Ȥ�
-��Ƥ���rb_scan_args()�Ǥ�����3�����˻��ꤷ���ե����ޥåȤ�
-��������4�ѿ��ʹߤ˻��ꤷ���ѿ����ͤ��������Ƥ���ޤ�������
-�ե����ޥåȤϡ���1ʸ���ܤ���ά�Ǥ��ʤ������ο�����2ʸ���ܤ�
-��ά�Ǥ�������ο�����3ʸ���ܤ��б�������̵꤬�����ޤ�ΰ�
-�������뤫�ɤ����򼨤�"*"�Ǥ���2ʸ���ܤ�3ʸ���ܤϾ�ά�Ǥ���
-����dbm.c����Ǥϡ��ե����ޥåȤ�"11"�Ǥ����顤�����Ϻ���1��
-�ǡ�2�Ĥޤǵ������Ȥ�����̣�ˤʤ�ޤ�����ά����Ƥ������
-�ѿ����ͤ�nil(C����Υ�٥�Ǥ�Qnil)�ˤʤ�ޤ���
-
-Ruby������ǰ������������Τ�indexes������ޤ��������Ϥ�
-���Ǥ���
-
---
-static VALUE
-fdbm_indexes(obj, args)
-    VALUE obj, args;
-{
-	:
-}
---
-
-The first argument is the receiver, the second one is the Ruby array
-which contains the arguments to the method.
-
-** Notice
-
-GC should know about global variables which refers Ruby's objects, but
-not exported to the Ruby world.  You need to protect them by
-
-  void rb_global_variable(VALUE *var)
-
-(5) prepare extconf.rb
-
-If there exists the file named extconf.rb, it will be executed to
-generate Makefile.  If not, compilation scheme try to generate
-Makefile anyway.
-
-extconf.rb�ϥ⥸�塼��Υ���ѥ����ɬ�פʾ��Υ����å��ʤ�
-��Ԥ����Ȥ���Ū�Ǥ���extconf.rb����Ǥϰʲ���Ruby�ؿ���Ȥ�
-���Ȥ�����ޤ���
-
-  have_library(lib, func): �饤�֥���¸�ߥ����å�
-  have_func(func): �ؿ���¸�ߥ����å�
-  have_header(header): �إå��ե������¸�ߥ����å�
-  create_makefile(target): Makefile������
-
-�ʲ����ѿ���Ȥ����Ȥ��Ǥ��ޤ���
-
-  $CFLAGS: ����ѥ�������ɲ�Ū�˻��ꤹ��ե饰(-I�ʤ�)
-  $LDFLAGS: ��󥯻����ɲ�Ū�˻��ꤹ��ե饰(-L�ʤ�)
-
-�⥸�塼��򥳥�ѥ��뤹���郎·��ʤ������Υ⥸�塼��ϥ�
-��ѥ��뤷�ʤ����ˤ�create_makefile��ƤФʤ����Makefile��
-�������줺������ѥ����Ԥ��ޤ���
-
-(6) prepare depend (optional)
-
-If the file named depend exists, Makefile will include that file to
-check dependency.  You can make this file by invoking
-
- % gcc -MM *.c > depend
-
-It's no harm.  Prepare it.
-
-(7) MANIFEST�ե�����˥ե�����̾�������
-
-  % find * -type f -print > MANIFEST
-  % vi MANIFEST
-
-Append file names into MANIFEST.  The compilation scheme requires
-MANIFEST only to be exist.  But, you'd better take this step to
-distinguish required files.
-
-(8) make
-
-Ruby�Υǥ��쥯�ȥ��make��¹Ԥ����Makefile����������make��
-ɬ�פˤ�äƤϤ��Υ⥸�塼���Ruby�ؤΥ�󥯤ޤǼ�ưŪ�˼¹�
-���Ƥ���ޤ���extconf.rb��񤭴�����ʤɤ���Makefile�κ�����
-��ɬ�פʻ��Ϥޤ�Ruby�ǥ��쥯�ȥ��make���Ƥ���������
-
-(9) debug
-
-You may need to rb_debug the module.  The modules can be linked 
-statically by adding directory name in the ext/Setup file,
-so that you can inspect the module by the debugger.
-
-(10) done, now you have the extension library
-
-You can do anything you want with your library.  The author of Ruby
-will not claim any restriction about your code depending Ruby API.
-Feel free to use, modify, distribute or sell your program.
-
-Appendix A. Ruby�Υ����������ɤ�ʬ��
-
-Ruby�Υ������Ϥ����Ĥ���ʬ�ह�뤳�Ȥ�����ޤ������Τ�������
-���饤�֥�����ʬ�ϴ���Ū�˳�ĥ�饤�֥���Ʊ��������ˤʤ�
-�Ƥ��ޤ��������Υ������Ϻ��ޤǤ������ǤۤȤ������Ǥ����
-�פ��ޤ���
-
-ruby language core
-
-  class.c
-  error.c
-  eval.c
-  gc.c
-  object.c
-  parse.y
-  variable.c
-
-utility functions
-
-  dln.c
-  fnmatch.c
-  glob.c
-  regex.c
-  st.c
-  util.c
-
-ruby interpreter implementation
-
-  dmyext.c
-  inits.c
-  main.c
-  ruby.c
-  version.c
-
-class library
-
-  array.c
-  bignum.c
-  compar.c
-  dir.c
-  enum.c
-  file.c
-  hash.c
-  io.c
-  math.c
-  numeric.c
-  pack.c
-  process.c
-  random.c
-  range.c
-  re.c
-  signal.c
-  sprintf.c
-  string.c
-  struct.c
-  time.c
-
-Appendix B. Ruby extension API reference
-
-C���줫��Ruby�ε�ǽ�����Ѥ���API�ϰʲ����̤�Ǥ��롥
-
-** ��
-
- VALUE
-
-Ruby���֥������Ȥ�ɽ�����뷿��ɬ�פ˱����ƥ��㥹�Ȥ����Ѥ��롥
-�Ȥ߹��߷���ɽ������C�η���ruby.h�˵��Ҥ��Ƥ���R�ǻϤޤ빽¤
-�ΤǤ��롥VALUE���򤳤��˥��㥹�Ȥ��뤿���R�ǻϤޤ빽¤��
-̾��������ʸ���ˤ���̾���Υޥ������Ѱդ���Ƥ��롥
-
-** Variables and constants
-
- Qnil
-
-const: nil object
-
- Qtrue
-
-const: Qtrue object(default true value)
-
- Qfalse
-
-const: Qfalse object
-
-** C pointer wrapping
-
- Data_Wrap_Struct(VALUE class, void (*mark)(), void (*free)(), void *sval)
-
-C��Ǥ�դΥݥ��󥿤򥫥ץ��벽����Ruby���֥������Ȥ��֤�����
-�Υݥ��󥿤�Ruby���饢����������ʤ��ʤä�����free�ǻ��ꤷ��
-�ؿ����ƤФ�롥�ޤ������Υݥ��󥿤λؤ��ǡ�����¾��Ruby����
-�������Ȥ�ؤ��Ƥ����硤mark�˻��ꤹ��ؿ��ǥޡ�������ɬ��
-�����롥
-
- Data_Make_Struct(class, type, mark, free, sval)
-
-type���Υ����malloc�����ѿ�sval�����������塤����򥫥ץ�
-�벽�����ǡ������֤��ޥ�����
-
- Data_Get_Struct(data, type, sval)
-
-data����type���Υݥ��󥿤���Ф��ѿ�sval����������ޥ�����
-
-** defining class/module
-
- VALUE rb_define_class(char *name, VALUE super)
-
-Defines new Ruby class as subclass of super.
-
- VALUE rb_define_class_under(VALUE module, char *name, VALUE super)
-
-Creates new Ruby class as subclass of super, under the module's
-namespace.
-
- VALUE rb_define_module(char *name)
-
-Defines new Ruby module.
-
- VALUE rb_define_module_under(VALUE module, char *name, VALUE super)
-
-Defines new Ruby module, under the modules's namespace.
-
- void rb_include_module(VALUE class, VALUE module)
-
-Includes module into class.  If class already includes it, just
-ignore.
-
- void rb_extend_object(VALUE object, VALUE module)
-
-Extend the object with module's attribute.
-
-** Defining Global Variables
-
- void rb_define_variable(char *name, VALUE *var)
-
-Defines a global variable which is shared between C and Ruby.  If name
-contains the character which is not allowed to be part of the symbol,
-it can't be seen from Ruby programs.
-
- void rb_define_readonly_variable(char *name, VALUE *var)
-
-Defines a read-only global variable.  Works just like
-rb_define_variable(), except defined variable is read-only.
-
- void rb_define_virtual_variable(char *name,
-				VALUE (*getter)(), VALUE (*setter)())
-
-Defines a virtual variable, whose behavior is defined by pair of C
-functions.  The getter function is called when the variable is
-referred. The setter function is called when the value is set to the
-variable.  The prototype for getter/setter functions are:
-
-	VALUE getter(ID id)
-	void setter(VALUE val, ID id)
-
-The getter function must return the value for the access.
-
- void rb_define_hooked_variable(char *name, VALUE *var,
-				VALUE (*getter)(), VALUE (*setter)())
-
-Defines hooked variable.  It's virtual variable with C variable.  The
-getter is called as
-
-	VALUE getter(ID id, VALUE *var)
-
-returning new value.  The setter is called as
-
-	void setter(VALUE val, ID id, VALUE *var)
-
-GC requires to mark the C global variables which hold Ruby values.
-
- void rb_global_variable(VALUE *var)
-
-Tells GC to protect these variables.
-
-** Constant Definition
-
- void rb_define_const(VALUE klass, char *name, VALUE val)
-
-Defines a new constant under the class/module.
-
- void rb_define_global_const(char *name, VALUE val)
-
-Defines global contant.  This is just work as
-
-     rb_define_const(cKernal, name, val)
-
-** Method Definition
-
- rb_define_method(VALUE class, char *name, VALUE (*func)(), int argc)
-
-Defines a method for the class.  func is the function pointer.  argc
-is the number of arguments.  if argc is -1, the function will receive
-3 arguments argc, argv, and self.  if argc is -2, the function will
-receive 2 arguments, self and args, where args is the Ruby array of
-the method arguments.
-
- rb_define_private_method(VALUE class, char *name, VALUE (*func)(), int argc)
-
-Defines a private method for the class.  Arguments are same as
-rb_define_method().
-
- rb_define_singleton_method(VALUE class, char *name, VALUE (*func)(), int argc)
-
-Defines a singleton method.  Arguments are same as rb_define_method().
-
- rb_scan_args(int atgc, VALUE *argv, char *fmt, ...)
-
-argc,argv������Ϳ����줿������ʬ�򤹤롥fmt��ɬ�ܰ����ο�, 
-�ղð����ο�, �Ĥ�ΰ��������뤫����ꤹ��ʸ�����, "������
-��*"�Ȥ��������Ǥ��롥 2 ���ܤο�����"*"�Ϥ��줾���ά��ǽ��
-���롥ɬ�ܰ�������Ĥ�ʤ�����0����ꤹ�롥��3�����ʹߤ���
-���ؤΥݥ��󥿤�, �����������Ǥ������ѿ��˳�Ǽ����롥�ղð�
-�����б����������Ϳ�����Ƥ��ʤ������ѿ���Qnil����������
-�롥
-
-** Ruby�᥽�åɸƤӽФ�
-
- VALUE rb_funcall(VALUE recv, ID mid, int narg, ...)
-
-Invokes the method.  To retrieve mid from method name, use rb_intern().
-
- VALUE rb_funcall2(VALUE recv, ID mid, int argc, VALUE *argv)
-
-Invokes method, passing arguments by array of values.
-
- VALUE rb_eval_string(char *str)
-
-Compiles and executes the string as Ruby program.
-
- ID rb_intern(char *name)
-
-Returns ID corresponding the name.
-
- char *rb_id2name(ID id)
-
-Returns the name corresponding ID.
-
- char *rb_class2name(VALUE class)
-
-Returns the name of the class.
-
-** Instance Variables
-
- VALUE rb_iv_get(VALUE obj, char *name)
-
-Retrieve the value of the instance variable.  If the name is not
-prefixed by `@', that variable shall be inaccessible from Ruby.
-
- VALUE rb_iv_set(VALUE obj, char *name, VALUE val)
-
-Sets the value of the instance variable.
-
-** Control Structure
-
- VALUE rb_iterate(VALUE (*func1)(), void *arg1, VALUE (*func2)(), void *arg2)
-
-func2��֥��å��Ȥ������ꤷ, func1�򥤥ƥ졼���Ȥ��ƸƤ֡� 
-func1�ˤ� arg1�������Ȥ����Ϥ���, func2�ˤ���1�����˥��ƥ졼
-������Ϳ����줿��, ��2������arg2���Ϥ���롥
- 
- VALUE rb_yield(VALUE val)
-
-val���ͤȤ��ƥ��ƥ졼���֥��å���ƤӽФ���
-
- VALUE rb_rescue(VALUE (*func1)(), void *arg1, VALUE (*func2)(), void *arg2)
-
-�ؿ�func1��arg1������˸ƤӽФ���func1�μ¹�����㳰��ȯ����
-�����ˤ� func2��arg2������Ȥ��ƸƤ֡�����ͤ��㳰��ȯ������
-���ä�����func1�������, �㳰��ȯ���������ˤ�func2������ͤ�
-���롥
-
- VALUE rb_ensure(VALUE (*func1)(), void *arg1, void (*func2)(), void *arg2)
-
-�ؿ�func1��arg1������Ȥ��Ƽ¹Ԥ�, �¹Խ�λ��(���Ȥ��㳰��ȯ
-�����Ƥ�) func2��arg2������Ȥ��Ƽ¹Ԥ��롥����ͤ�func1����
-���ͤǤ���(�㳰��ȯ�������������ʤ�)��
-
-** �㳰�����顼
-
- void rb_warning(char *fmt, ...)
-
-rb_verbose����ɸ�२�顼���Ϥ˷ٹ�����ɽ�����롥������printf()��Ʊ����
-
- void rb_raise(rb_eRuntimeError, char *fmt, ...)
-
-�㳰��ȯ�������롥������printf()��Ʊ����
-
- void rb_fatal(char *fmt, ...)
-
-��̿Ū�㳰��ȯ�������롥�̾���㳰�����ϹԤʤ�줺, ���󥿡�
-�ץ꥿����λ����(������ensure�ǻ��ꤵ�줿�����ɤϽ�λ���˼�
-�Ԥ����)��
-
- void rb_bug(char *fmt, ...)
-
-���󥿡��ץ꥿�ʤɥץ������ΥХ��Ǥ���ȯ������Ϥ��Τʤ���
-���λ��Ƥ֡����󥿡��ץ꥿�ϥ�������פ�ľ���˽�λ���롥�㳰
-�����ϰ��ڹԤʤ��ʤ���
-
-** Initialize and Starts the Interpreter
-
-The embedding API are below (not needed for extension libraries):
-
- void ruby_init(int argc, char **argv, char **envp)
-
-Initializes the interpreter.
-
- void ruby_run()
-
-Starts execution of the interpreter.
-
- void ruby_script(char *name)
-
-Specifies the name of the script ($0).
-
-Appendix B. Functions Available in extconf.rb
-
-extconf.rb����Ǥ����Ѳ�ǽ�ʥ���ѥ���������å��δؿ��ϰ�
-�����̤�Ǥ��롥
-
- have_library(lib, func)
-
-Checks whether library which contains specified function exists.
-Returns true if the library exists.
-
- have_func(func)
-
-Checks whether func exists.  Returns true if the function exists.  To
-check functions in the additional library, you need to check that
-library first using have_library().
-
- have_header(header)
-
-Checks for the header files.  Returns true if the header file exists.
-
- create_makefile(target)
-
-Generates the Makefile for the extension library.  If you don't invoke
-this method, the compilation will not be done.
-
-/*
- * Local variables:
- * fill-column: 70
- * end:
- */
+Moved to doc/extension.rdoc
diff --git a/README.EXT.ja b/README.EXT.ja
new file mode 100644
index 0000000000..f884ecbb0e
--- /dev/null
+++ b/README.EXT.ja
@@ -0,0 +1 @@
+doc/extension.ja.rdocに移動しました
diff --git a/README.EXT.jp b/README.EXT.jp
deleted file mode 100644
index 6adeab3f0b..0000000000
--- a/README.EXT.jp
+++ /dev/null
@@ -1,1144 +0,0 @@
-.\" README.EXT -  -*- Text -*- created at: Mon Aug  7 16:45:54 JST 1995
-
-Ruby�γ�ĥ�饤�֥��κ�������������ޤ���
-
-1�������μ�
-
-C���ѿ��ˤϷ������ꡤ�ǡ����ˤϷ�������ޤ��󡥤Ǥ����顤��
-�Ȥ��Хݥ��󥿤�int���ѿ�����������ȡ������ͤ������Ȥ��Ƽ�
-�갷���ޤ����դ�Ruby���ѿ��ˤϷ����ʤ����ǡ����˷��������
-�������ΰ㤤�Τ��ᡤC��Ruby����ߤ��Ѵ����ʤ���С����ߤ���
-�ǡ����򥢥������Ǥ��ޤ���
-
-Ruby�Υǡ�����VALUE�Ȥ���C�η���ɽ������ޤ���VALUE���Υǡ�
-���Ϥ��Υǡ��������פ�ʬ���ΤäƤ��ޤ������Υǡ��������פ�
-�����Τϥǡ���(���֥�������)�μºݤι�¤���̣���Ƥ��ơ�Ruby
-�Υ��饹�ȤϤޤ���ä���ΤǤ���
-
-VALUE����C�ˤȤäư�̣�Τ���ǡ�������Ф�����ˤ�
-
- (1) VALUE�Υǡ��������פ��Τ�
- (2) VALUE��C�Υǡ������Ѵ�����
-
-��ξ����ɬ�פǤ���(1)��˺���ȴְ�ä��ǡ������Ѵ����Ԥ��
-�ơ��ǰ��ץ�����बcore dump���ޤ���
-
-1.1 �ǡ���������
-
-Ruby�ˤϥ桼�����Ȥ���ǽ���Τ���ʲ��Υ����פ�����ޤ���
-
-	T_NIL		nil
-	T_OBJECT	�̾�Υ��֥�������
-	T_CLASS		���饹
-	T_MODULE	�⥸�塼��
-	T_FLOAT		��ư��������
-	T_STRING	ʸ����
-	T_REGEXP	����ɽ��
-	T_ARRAY		����
-	T_FIXNUM	Fixnum(31bitĹ����)
-	T_HASH		Ϣ������
-	T_STRUCT	(Ruby��)��¤��
-	T_BIGNUM	¿��Ĺ����
-	T_FILE		������
-	T_TRUE		��
-	T_FALSE		��
-	T_DATA		�ǡ���
-
-����¾�����������Ѥ���Ƥ���ʲ��Υ����פ�����ޤ���
-
-	T_ICLASS
-	T_MATCH
-	T_VARMAP
-	T_SCOPE
-	T_NODE
-
-�ۤȤ�ɤΥ����פ�C�ι�¤�ΤǼ�������Ƥ��ޤ���
-
-1.2 VALUE�Υǡ��������פ�����å�����
-
-ruby.h�Ǥ�TYPE()�Ȥ����ޥ������������Ƥ��ơ�VALUE�Υǡ���
-�����פ��Τ뤳�Ȥ�����ޤ���TYPE()�ޥ����Ͼ�ǾҲ𤷤�T_XXXX
-�η�����������֤��ޤ���VALUE�Υǡ��������פ˱����ƽ�������
-���ˤϡ�TYPE()���ͤ�ʬ�����뤳�Ȥˤʤ�ޤ���
-
-  switch (TYPE(obj)) {
-    case T_FIXNUM:
-      /* FIXNUM�ν��� */
-      break;
-    case T_STRING:
-      /* ʸ����ν��� */
-      break;
-    case T_ARRAY:
-      /* ����ν��� */
-      break;
-    default:
-      /* �㳰��ȯ�������� */
-      TypeError("not valid value");
-      break;
-  }
-
-����ȥǡ��������פ�����å����ơ��������ʤ�����㳰��ȯ����
-��ؿ����Ѱդ���Ƥ��ޤ���
-
-  void Check_Type(VALUE value, int type)
-
-���δؿ���value��type��̵����С��㳰��ȯ�������ޤ���������
-����Ϳ����줿VALUE�Υǡ��������פ����������ɤ��������å���
-�뤿��ˤϡ����δؿ���Ȥ��ޤ���
-
-FIXNUM��NIL�˴ؤ��ƤϤ���®��Ƚ�̥ޥ������Ѱդ���Ƥ��ޤ���
-
-  FIXNUM_P(obj)
-  NIL_P(obj)
-
-1.3 VALUE��C�Υǡ������Ѵ�����
-
-�ǡ��������פ�T_NIL, T_FALSE, T_TRUE�Ǥ�������ǡ����Ϥ��줾
-��nil, false, true�Ǥ������Υǡ��������פΥ��֥������ȤϤҤ�
-�Ĥ��Ĥ���¸�ߤ��ޤ���
-
-�ǡ��������פ�T_FIXNUM�λ��������31bit�Υ����������������
-����FIXNUM��C���������Ѵ����뤿��ˤϥޥ�����FIX2INT()�פ��
-���ޤ������줫�顤FIXNUM�˸¤餺Ruby�Υǡ������������Ѵ�����
-��NUM2INT()�פȤ����ޥ���������ޤ������Υޥ����ϥǡ�������
-�פΥ����å�̵���ǻȤ��ޤ�(�������Ѵ��Ǥ��ʤ����ˤ��㳰��
-ȯ������)��
-
-Ʊ�ͤ˥����å�̵���ǻȤ����Ѵ��ޥ�����double����Ф�
-��NUM2DBL()�פ�char*����Ф���STR2CSTR()�פ�����ޤ���
-
-����ʳ��Υǡ��������פ��б�����C�ι�¤�Τ�����ޤ����б���
-�빽¤�ΤΤ���VALUE�Ϥ��Τޤޥ��㥹��(���Ѵ�)����й�¤�Τ�
-�ݥ��󥿤��Ѵ��Ǥ��ޤ���
-
-��¤�Τϡ�struct RXxxxx�פȤ���̾����ruby.h���������Ƥ���
-�����㤨��ʸ����ϡ�struct RString�פǤ����ºݤ˻Ȥ���ǽ����
-����Τ�ʸ��������󤯤餤���Ȼפ��ޤ���
-
-ruby.h�ǤϹ�¤�Τإ��㥹�Ȥ���ޥ������RXXXXX()��(������ʸ
-���ˤ������)�Ȥ���̾�����󶡤���Ƥ��ޤ�(��: RSTRING())��
-
-�㤨�С�ʸ����str��Ĺ�������뤿��ˤϡ�RSTRING(str)->len�פ�
-����ʸ����str��char*�Ȥ������뤿��ˤϡ�RSTRING(str)->ptr��
-�Ȥ��ޤ�������ξ��ˤϡ����줾���RARRAY(ary)->len�ס�
-��RARRAY(ary)->ptr�פȤʤ�ޤ���
-
-Ruby�ι�¤�Τ�ľ�ܥ�������������˵���Ĥ��ʤ���Фʤ�ʤ���
-�Ȥϡ������ʸ����ι�¤�Τ���Ȥϻ��Ȥ�������ǡ�ľ���ѹ���
-�ʤ����ȤǤ���ľ���ѹ�������硤���֥������Ȥ����Ƥ���������
-�Ȥ�ʤ��ʤäơ��פ�̥Х��θ����ˤʤ�ޤ���
-
-1.4 C�Υǡ�����VALUE���Ѵ�����
-
-VALUE�μºݤι�¤��
-
-  * FIXNUM�ξ��
-
-    1bit�����եȤ��ơ�LSB��Ω�Ƥ롥
-
-  * ����¾�Υݥ��󥿤ξ��
-
-    ���Τޤ�VALUE�˥��㥹�Ȥ��롥
-
-�ȤʤäƤ��ޤ�����äơ�LSB������å������VALUE��FIXNUM����
-�����狼��櫓�Ǥ�(�ݥ��󥿤�LSB��Ω�äƤ��ʤ����Ȥ��ꤷ��
-����)��
-
-�Ǥ����顤FIXNUM�ʳ���Ruby�Υ��֥������Ȥι�¤�Τ�ñ��VALUE
-�˥��㥹�Ȥ��������VALUE���Ѵ�����ޤ�����������Ǥ�դι�¤
-�Τ�VALUE�˥��㥹�Ƚ����櫓�ǤϤ���ޤ��󡥥��㥹�Ȥ����
-��Ruby���ΤäƤ��빽¤��(ruby.h���������Ƥ���struct RXxxx
-�Τ��)�����Ǥ���
-
-FIXNUM�˴ؤ��Ƥ��Ѵ��ޥ������ͳ����ɬ�פ�����ޤ���C������
-����VALUE���Ѵ�����ޥ����ϰʲ��Τ�Τ�����ޤ���ɬ�פ˱���
-�ƻȤ�ʬ���Ƥ���������
-
-  INT2FIX()	��Ȥ�������31bit����˼��ޤ뼫���������
-  INT2NUM()	Ǥ�դ���������VALUE��
-
-INT2NUM()��������FIXNUM���ϰϤ˼��ޤ�ʤ���硤Bignum���Ѵ�
-���Ƥ���ޤ�(���������٤�)��
-
-1.5 Ruby�Υǡ���������
-
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-�Ԥ����Ȥϴ�����ޤ��󡥤ǡ�Ruby�Υǡ�����������ˤ�
-Ruby���Ѱդ��Ƥ���ؿ����Ѥ��Ƥ���������
-
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-���ؿ��򤢤��ޤ�(�����ǤϤʤ��Ǥ�)��
-
- ʸ������Ф���ؿ�
-
-  rb_str_new(char *ptr, int len)
-
-    ������Ruby��ʸ������������롥
-
-  rb_str_new2(char *ptr)
-
-    C��ʸ���󤫤�Ruby��ʸ������������롥���δؿ��ε�ǽ��
-    rb_str_new(ptr, strlen(ptr))��Ʊ���Ǥ��롥
-
-  rb_str_cat(VALUE str, char *ptr, int len)
-
-    Ruby��ʸ����str��len�Х��Ȥ�ʸ����ptr���ɲä��롥
-
- ������Ф���ؿ�
-
-  rb_ary_new()
-
-    ���Ǥ�0��������������롥
-
-  rb_ary_new2(int len)
-
-    ���Ǥ�0��������������롥len����ʬ���ΰ�򤢤餫������
-    ���ƤƤ�����
-
-  rb_ary_new3(int n, ...)
-
-    �����ǻ��ꤷ��n���Ǥ�ޤ�������������롥
-
-  rb_ary_new4(int n, VALUE *elts)
-
-    �����Ϳ����n���Ǥ�������������롥
-
-  rb_ary_push(VALUE ary, VALUE val)
-  rb_ary_pop(VALUE ary)
-  rb_ary_shift(VALUE ary)
-  rb_ary_unshift(VALUE ary, VALUE val)
-  rb_ary_entry(VALUE ary, int idx)
-
-    Array��Ʊ̾�Υ᥽�åɤ�Ʊ��Ư���򤹤�ؿ�����1������ɬ��
-    ����Ǥʤ���Фʤ�ʤ���
-
-2��Ruby�ε�ǽ��Ȥ�
-
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-�𤷤ޤ���
-
-2.1 Ruby�˵�ǽ���ɲä���
-
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-�󶡤���Ƥ��ޤ���
-
- * ���饹���⥸�塼��
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-
-2.1.1 ���饹/�⥸�塼�����
-
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-
-  VALUE rb_define_class(char *name, VALUE super)
-  VALUE rb_define_module(char *name)
-
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-
-  VALUE rb_define_class(VALUE outer, char *name, VALUE super)
-  VALUE rb_define_module(VALUE outer, char *name)
-
-2.1.2 �᥽�å�/�ðۥ᥽�å����
-
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-
-  void rb_define_method(VALUE class, char *name, 
-		        VALUE (*func)(), int argc)
-
-  void rb_define_singleton_method(VALUE object, char *name, 
-			          VALUE (*func)(), int argc)
-
-
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-�򶵤��Ƥ����Ƥ����������Ǥʤ���GC�ǥȥ�֥�򵯤����ޤ���
-
-  void rb_global_variable(VALUE *var)
-
-(5) extconf.rb���Ѱդ���
-
-Makefile������ο����ˤʤ�extconf.rb�Ȥ����ե��������
-�ޤ���extconf.rb�ϥ⥸�塼��Υ���ѥ����ɬ�פʾ��Υ�����
-���ʤɤ�Ԥ����Ȥ���Ū�Ǥ���extconf.rb����Ǥϰʲ���Ruby�ؿ�
-��Ȥ����Ȥ�����ޤ���
-
-  have_library(lib, func): �饤�֥���¸�ߥ����å�
-  have_func(func): �ؿ���¸�ߥ����å�
-  have_header(header): �إå��ե������¸�ߥ����å�
-  create_makefile(target): Makefile������
-
-�ʲ����ѿ���Ȥ����Ȥ��Ǥ��ޤ���
-
-  $CFLAGS: ����ѥ�������ɲ�Ū�˻��ꤹ��ե饰(-I�ʤ�)
-  $LDFLAGS: ��󥯻����ɲ�Ū�˻��ꤹ��ե饰(-L�ʤ�)
-
-�⥸�塼��򥳥�ѥ��뤹���郎·��ʤ������Υ⥸�塼��ϥ�
-��ѥ��뤷�ʤ����ˤ�create_makefile��ƤФʤ����Makefile��
-�������줺������ѥ����Ԥ��ޤ���
-
-�⥸�塼�뤬Ruby 1.1���ѤǤ�����ˤ� 
-
-  require 'mkmf'
-
-��extconf.rb����Ƭ���֤��������Ǥ��礦��
-
-(6) depend���Ѱդ���
-
-�⤷���ǥ��쥯�ȥ��depend�Ȥ����ե����뤬¸�ߤ���С�
-Makefile����¸�ط�������å����Ƥ���ޤ���
-
- % gcc -MM *.c > depend
-
-�ʤɤǺ�뤳�Ȥ�����ޤ������ä�»��̵���Ǥ��礦��
-
-(7) MANIFEST�ե�����˥ե�����̾�������
-
-  % find * -type f -print > MANIFEST
-  % vi MANIFEST
-
-*.o, *~�ʤ���ɬ�פʥե�����ʳ���MANIFEST���ɲä��Ƥ����ޤ���
-make���ˤ�MANIFEST�����Ƥϻ��Ȥ��ޤ���Τǡ����ΤޤޤǤ�����
-�ϵ����ޤ��󤬡��ѥå������󥰤λ��˻��Ȥ��뤳�Ȥ�����Τȡ�
-ɬ�פʥե��������̤Ǥ���Τǡ��Ѱդ��Ƥ����������ɤ��Ǥ���
-����
-
-(8) Makefile����������
-
-Makefile��ºݤ��������뤿��ˤ�
-
-  ruby extconf.rb
-
-�Ȥ��ޤ���extconf.rb�� require 'mkmf' �ιԤ��ʤ����ˤϥ��顼
-�ˤʤ�ޤ��Τǡ��������ɲä���
-
-  ruby -r mkmf extconf.rb
-
-�Ȥ��Ƥ���������
-
-�ǥ��쥯�ȥ��ext�ʲ����Ѱդ������ˤ�Ruby���Τ�make�λ���
-��ưŪ��Makefile����������ޤ��Τǡ����Υ��ƥåפ����פǤ���
-
-(9) make����
-
-ưŪ��󥯥饤�֥�������������ˤϤ��ξ��make���Ƥ�����
-����ɬ�פǤ���� make install �ǥ��󥹥ȡ��뤵��ޤ���
-
-ext�ʲ��˥ǥ��쥯�ȥ���Ѱդ������ϡ�Ruby�Υǥ��쥯�ȥ��
-make��¹Ԥ����Makefile����������make��ɬ�פˤ�äƤϤ��Υ�
-���塼���Ruby�ؤΥ�󥯤ޤǼ�ưŪ�˼¹Ԥ��Ƥ���ޤ���
-extconf.rb��񤭴�����ʤɤ���Makefile�κ�������ɬ�פʻ��Ϥ�
-��Ruby�ǥ��쥯�ȥ��make���Ƥ���������
-
-ưŪ��󥯥饤�֥���make install��Ruby�饤�֥��Υǥ��쥯
-�ȥ�β��˥��ԡ�����ޤ����⤷�⥸�塼��ȶ�Ĵ���ƻȤ�Ruby��
-���Ҥ��줿�ץ�����ब���ꡤRuby�饤�֥����֤��������ˤϡ�
-��ĥ�饤�֥���ѤΥǥ��쥯�ȥ�β��� lib �Ȥ����ǥ��쥯�ȥ�
-���ꡤ������ ��ĥ�� .rb �Υե�������֤��Ƥ�����Ʊ���˥���
-���ȡ��뤵��ޤ���
-
-(10) �ǥХå�
-
-�ޤ����ǥХå����ʤ���ư���ʤ��Ǥ��礦�͡�ext/Setup�˥ǥ���
-���ȥ�̾��񤯤���Ū�˥�󥯤���ΤǥǥХå����Ȥ���褦�ˤ�
-��ޤ�������ʬ����ѥ��뤬�٤��ʤ�ޤ����ɡ�
-
-(11) �Ǥ�������
-
-��Ϥ��ä���Ȥ��ʤꡤ������������ʤꡤ���ʤꡤ����ͳ�ˤ�
-�Ȥ�����������Ruby�κ�Ԥϳ�ĥ�饤�֥��˴ؤ��ư��ڤθ�����
-��ĥ���ޤ���
-
-Appendix A. Ruby�Υ����������ɤ�ʬ��
-
-Ruby�Υ������Ϥ����Ĥ���ʬ�ह�뤳�Ȥ�����ޤ������Τ�������
-���饤�֥�����ʬ�ϴ���Ū�˳�ĥ�饤�֥���Ʊ��������ˤʤ�
-�Ƥ��ޤ��������Υ������Ϻ��ޤǤ������ǤۤȤ������Ǥ����
-�פ��ޤ���
-
-Ruby����Υ���
-
-  class.c
-  error.c
-  eval.c
-  gc.c
-  object.c
-  parse.y
-  variable.c
-
-�桼�ƥ���ƥ��ؿ�
-
-  dln.c
-  fnmatch.c
-  glob.c
-  regex.c
-  st.c
-  util.c
-
-Ruby���ޥ�ɤμ���
-
-  dmyext.c
-  inits.c
-  main.c
-  ruby.c
-  version.c
-
-���饹�饤�֥��
-
-  array.c
-  bignum.c
-  compar.c
-  dir.c
-  enum.c
-  file.c
-  hash.c
-  io.c
-  marshal.c
-  math.c
-  numeric.c
-  pack.c
-  process.c
-  random.c
-  range.c
-  re.c
-  signal.c
-  sprintf.c
-  string.c
-  struct.c
-  time.c
-
-Appendix B. ��ĥ�Ѵؿ���ե����
-
-C���줫��Ruby�ε�ǽ�����Ѥ���API�ϰʲ����̤�Ǥ��롥
-
-** ��
-
- VALUE
-
-Ruby���֥������Ȥ�ɽ�����뷿��ɬ�פ˱����ƥ��㥹�Ȥ����Ѥ��롥
-�Ȥ߹��߷���ɽ������C�η���ruby.h�˵��Ҥ��Ƥ���R�ǻϤޤ빽¤
-�ΤǤ��롥VALUE���򤳤��˥��㥹�Ȥ��뤿���R�ǻϤޤ빽¤��
-̾��������ʸ���ˤ���̾���Υޥ������Ѱդ���Ƥ��롥
-
-** �ѿ������
-
- Qnil
-
-���: nil���֥�������
-
- Qtrue
-
-���: true���֥�������(���Υǥե������)
-
- Qfalse
-
-���: false���֥�������
-
-** C�ǡ����Υ��ץ��벽
-
- Data_Wrap_Struct(VALUE class, void (*mark)(), void (*free)(), void *sval)
-
-C��Ǥ�դΥݥ��󥿤򥫥ץ��벽����Ruby���֥������Ȥ��֤�����
-�Υݥ��󥿤�Ruby���饢����������ʤ��ʤä�����free�ǻ��ꤷ��
-�ؿ����ƤФ�롥�ޤ������Υݥ��󥿤λؤ��ǡ�����¾��Ruby����
-�������Ȥ�ؤ��Ƥ����硤mark�˻��ꤹ��ؿ��ǥޡ�������ɬ��
-�����롥
-
- Data_Make_Struct(class, type, mark, free, sval)
-
-type���Υ����malloc�����ѿ�sval�����������塤����򥫥ץ�
-�벽�����ǡ������֤��ޥ�����
-
- Data_Get_Struct(data, type, sval)
-
-data����type���Υݥ��󥿤���Ф��ѿ�sval����������ޥ�����
-
-** �������å�
-
- TYPE(value)
- FIXNUM_P(value)
- NIL_P(value)
- void Check_Type(VALUE value, int type)
- void Check_SafeStr(VALUE value)
-
-** ���Ѵ�
-
- FIX2INT(value)
- INT2FIX(i)
- NUM2INT(value)
- INT2NUM(i)
- NUM2DBL(value)
- rb_float_new(f)
- STR2CSTR(value)
- rb_str_new2(s)
-
-** ���饹/�⥸�塼�����
-
- VALUE rb_define_class(char *name, VALUE super)
-
-super�Υ��֥��饹�Ȥ��ƿ�����Ruby���饹��������롥
-
- VALUE rb_define_class_under(VALUE module, char *name, VALUE super)
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-super�Υ��֥��饹�Ȥ��ƿ�����Ruby���饹���������module����
-���Ȥ���������롥
-
- VALUE rb_define_module(char *name)
-
-������Ruby�⥸�塼���������롥
-
- VALUE rb_define_module_under(VALUE module, char *name, VALUE super)
-
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-
- void rb_include_module(VALUE class, VALUE module)
-
-�⥸�塼��򥤥󥯥롼�ɤ��롥class�����Ǥ�module�򥤥󥯥롼
-�ɤ��Ƥ�����ˤϲ��⤷�ʤ�(¿�ť��󥯥롼�ɤζػ�)��
-
- void rb_extend_object(VALUE object, VALUE module)
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-
-** ����ѿ����
-
- void rb_define_variable(char *name, VALUE *var)
-
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-�ϸ����ʤ��ʤ롥
-
- void rb_define_readonly_variable(char *name, VALUE *var)
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-only�Ǥ��뤳�Ȱʳ���rb_define_variable()��Ʊ����
-
- void rb_define_virtual_variable(char *name,
-				VALUE (*getter)(), VALUE (*setter)())
-
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-�ˤ�getter�����ѿ����ͤ����åȤ��줿���ˤ�setter���ƤФ�롥
-
- void rb_define_hooked_variable(char *name, VALUE *var,
-				VALUE (*getter)(), VALUE (*setter)())
-
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-
- void rb_global_variable(VALUE *var)
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-���Ȥ�ޤ�����ѿ���ޡ������롥
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-
- void rb_define_const(VALUE klass, char *name, VALUE val)
-
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-
- void rb_define_global_const(char *name, VALUE val)
-
-��������������롥
-
-     rb_define_const(cKernal, name, val)
-
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-
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-����Ϳ�����롥
-
- rb_define_private_method(VALUE class, char *name, VALUE (*func)(), int argc)
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-
- rb_define_singleton_method(VALUE class, char *name, VALUE (*func)(), int argc)
-
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-
- rb_scan_args(int atgc, VALUE *argv, char *fmt, ...)
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-��*"�Ȥ��������Ǥ��롥 2 ���ܤο�����"*"�Ϥ��줾���ά��ǽ��
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- VALUE rb_funcall(VALUE recv, ID mid, int narg, ...)
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-
- VALUE rb_eval_string(char *str)
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- ID rb_intern(char *name)
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-
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- VALUE rb_iterate(VALUE (*func1)(), void *arg1, VALUE (*func2)(), void *arg2)
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-func2��֥��å��Ȥ������ꤷ, func1�򥤥ƥ졼���Ȥ��ƸƤ֡� 
-func1�ˤ� arg1�������Ȥ����Ϥ���, func2�ˤ���1�����˥��ƥ졼
-������Ϳ����줿��, ��2������arg2���Ϥ���롥
- 
- VALUE rb_yield(VALUE val)
-
-val���ͤȤ��ƥ��ƥ졼���֥��å���ƤӽФ���
-
- VALUE rb_rescue(VALUE (*func1)(), void *arg1, VALUE (*func2)(), void *arg2)
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-
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- void rb_raise(rb_eRuntimeError, char *fmt, ...)
-
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-
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-
-
-Appendix B. extconf.rb�ǻȤ���ؿ�����
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diff --git a/README.ja.md b/README.ja.md
new file mode 100644
index 0000000000..6663b94680
--- /dev/null
+++ b/README.ja.md
@@ -0,0 +1,180 @@
+[![Build Status](https://travis-ci.org/ruby/ruby.svg?branch=master)](https://travis-ci.org/ruby/ruby)
+[![Build status](https://ci.appveyor.com/api/projects/status/0sy8rrxut4o0k960/branch/master?svg=true)](https://ci.appveyor.com/project/ruby/ruby/branch/master)
+[![Actions Status](https://github.com/ruby/ruby/workflows/macOS/badge.svg)](https://github.com/ruby/ruby/actions?query=workflow%3A"macOS")
+[![Actions Status](https://github.com/ruby/ruby/workflows/MinGW/badge.svg)](https://github.com/ruby/ruby/actions?query=workflow%3A"MinGW")
+[![Actions Status](https://github.com/ruby/ruby/workflows/MJIT/badge.svg)](https://github.com/ruby/ruby/actions?query=workflow%3A"MJIT")
+[![Actions Status](https://github.com/ruby/ruby/workflows/Ubuntu/badge.svg)](https://github.com/ruby/ruby/actions?query=workflow%3A"Ubuntu")
+[![Actions Status](https://github.com/ruby/ruby/workflows/Windows/badge.svg)](https://github.com/ruby/ruby/actions?query=workflow%3A"Windows")
+
+# Rubyとは
+
+Rubyはシンプルかつ強力なオブジェクト指向スクリプト言語です． Rubyは純粋なオブジェクト指向言語として設計されているので，
+オブジェクト指向プログラミングを手軽に行う事が出来ます．もちろん普通の手続き型のプログラミングも可能です．
+
+Rubyはテキスト処理関係の能力などに優れ，Perlと同じくらい強力です．さらにシンプルな文法と，
+例外処理やイテレータなどの機構によって，より分かりやすいプログラミングが出来ます．
+
+## Rubyの特長
+
+*   シンプルな文法
+*   普通のオブジェクト指向機能(クラス，メソッドコールなど)
+*   特殊なオブジェクト指向機能(Mixin，特異メソッドなど)
+*   演算子オーバーロード
+*   例外処理機能
+*   イテレータとクロージャ
+*   ガーベージコレクタ
+*   ダイナミックローディング (アーキテクチャによる)
+*   移植性が高い．多くのUnix-like/POSIX互換プラットフォーム上で動くだけでなく，Windows， macOS，
+    Haikuなどの上でも動く cf.
+    https://github.com/ruby/ruby/blob/master/doc/contributing.rdoc#platform-maintainers
+
+
+## 入手法
+
+サードパーティーツールを使った方法を含むRubyのインストール方法の一覧は
+
+https://www.ruby-lang.org/ja/downloads/
+
+を参照してください．
+
+### Git
+
+ミラーをGitHubに公開しています． 以下のコマンドでリポジトリを取得できます．
+
+    $ git clone https://github.com/ruby/ruby.git
+
+他のブランチの一覧は次のコマンドで見られます．
+
+    $ git ls-remote https://github.com/ruby/ruby.git
+
+Rubyリポジトリの本来のmasterは https://git.ruby-lang.org/ruby.git にあります．
+コミッタはこちらを使います．
+
+### Subversion
+
+古いRubyのバージョンのソースコードは次のコマンドでも取得できます．
+
+    $ svn co https://svn.ruby-lang.org/repos/ruby/branches/ruby_2_6/ ruby
+
+他のブランチの一覧は次のコマンドで見られます．
+
+    $ svn ls https://svn.ruby-lang.org/repos/ruby/branches/
+
+
+## ホームページ
+
+RubyのホームページのURLは
+
+https://www.ruby-lang.org/
+
+です．
+
+## メーリングリスト
+
+Rubyのメーリングリストがあります．参加希望の方は [ruby-list-request@ruby-lang.org] まで本文に
+
+    subscribe
+
+と書いて送って下さい．
+
+Ruby開発者向けメーリングリストもあります．こちらではrubyのバグ，将来の仕様拡張など実装上の問題について議論されています．
+参加希望の方は [ruby-dev-request@ruby-lang.org] までruby-listと同様の方法でメールしてください．
+
+Ruby拡張モジュールについて話し合うruby-extメーリングリストと数学関係の話題について話し合うruby-mathメーリングリストと
+英語でrubyについて話し合うruby-talkメーリングリストもあります．参加方法はどれも同じです．
+
+[ruby-list-request@ruby-lang.org]: mailto:ruby-list-request@ruby-lang.org?subject=Join%20Ruby%20Mailing%20List&body=subscribe
+[ruby-dev-request@ruby-lang.org]: mailto:ruby-dev-request@ruby-lang.org?subject=Join%20Ruby%20Mailing%20List&body=subscribe
+
+## コンパイル・インストール
+
+以下の手順で行ってください．
+
+1.  (Gitリポジトリから取得したソースをビルドする場合) `./autogen.sh` を実行して新しく `configure` を生成する
+
+2.  `configure` を実行して `Makefile` などを生成する
+
+    環境によってはデフォルトのCコンパイラ用オプションが付きます． `configure` オプションで `optflags=..`
+    `warnflags=..` 等で上書きできます．
+
+3.  (必要ならば)`include/ruby/defines.h` を編集する
+
+    多分，必要無いと思います．
+
+4.  (必要ならば)`ext/Setup` に静的にリンクする拡張モジュールを指定する
+
+    `ext/Setup` に記述したモジュールは静的にリンクされます．
+
+    ダイナミックローディングをサポートしていないアーキテクチャでは `Setup` の1行目の「`option nodynamic`」という行のコ
+    メントを外す必要があります．
+    また，このアーキテクチャで拡張モジュールを利用するためには，あらかじめ静的にリンクをしておく必要があります．
+
+5.  `make` を実行してコンパイルする
+
+6.  `make check`でテストを行う．
+
+    「`check succeeded`」と表示されれば成功です．ただしテストに成功しても完璧だと保証されている訳ではありません．
+
+7.  `make install`
+
+    以下のディレクトリを作って，そこにファイルをインストー ルします．
+
+    *   `${DESTDIR}${prefix}/bin`
+    *   `${DESTDIR}${prefix}/include/ruby-${MAJOR}.${MINOR}.${TEENY}`
+    *   `${DESTDIR}${prefix}/include/ruby-${MAJOR}.${MINOR}.${TEENY}/${PLATFORM}`
+    *   `${DESTDIR}${prefix}/lib`
+    *   `${DESTDIR}${prefix}/lib/ruby`
+    *   `${DESTDIR}${prefix}/lib/ruby/${MAJOR}.${MINOR}.${TEENY}`
+    *   `${DESTDIR}${prefix}/lib/ruby/${MAJOR}.${MINOR}.${TEENY}/${PLATFORM}`
+    *   `${DESTDIR}${prefix}/lib/ruby/site_ruby`
+    *   `${DESTDIR}${prefix}/lib/ruby/site_ruby/${MAJOR}.${MINOR}.${TEENY}`
+    *   `${DESTDIR}${prefix}/lib/ruby/site_ruby/${MAJOR}.${MINOR}.${TEENY}/${PLATFORM}`
+    *   `${DESTDIR}${prefix}/lib/ruby/vendor_ruby`
+    *   `${DESTDIR}${prefix}/lib/ruby/vendor_ruby/${MAJOR}.${MINOR}.${TEENY}`
+    *   `${DESTDIR}${prefix}/lib/ruby/vendor_ruby/${MAJOR}.${MINOR}.${TEENY}/${PLATFORM}`
+    *   `${DESTDIR}${prefix}/lib/ruby/gems/${MAJOR}.${MINOR}.${TEENY}`
+    *   `${DESTDIR}${prefix}/share/man/man1`
+    *   `${DESTDIR}${prefix}/share/ri/${MAJOR}.${MINOR}.${TEENY}/system`
+
+
+    RubyのAPIバージョンが'*x.y.z*'であれば，`${MAJOR}`は
+    '*x*'で，`${MINOR}`は'*y*'，`${TEENY}`は'*z*'です．
+
+    **注意**: APIバージョンの `teeny` は，Rubyプログラムのバージョンとは異なることがあります．
+
+    `root` で作業する必要があるかもしれません．
+
+
+もし，コンパイル時にエラーが発生した場合にはエラーのログとマシン，OSの種類を含むできるだけ詳しいレポートを作者に送って下さると他の方のためにもなります．
+
+## 移植
+
+UNIXであれば `configure` がほとんどの差異を吸収してくれるはずですが，思わぬ見落としがあった場合(ある事が多い)，作者にその
+ことを報告すれば，解決できる可能性があります．
+
+アーキテクチャにもっとも依存するのはGC部です．RubyのGCは対象
+のアーキテクチャが`setjmp()`または`getcontext()`によって全てのレジスタを `jmp_buf` や `ucontext_t`
+に格納することと， `jmp_buf` や `ucontext_t` とスタックが32bitアラインメントされていることを仮定
+しています．特に前者が成立しない場合の対応は非常に困難でしょう． 後者の解決は比較的簡単で， `gc.c` でスタックをマークしている
+部分にアラインメントのバイト数だけずらしてマークするコードを追加するだけで済みます．`defined(__mc68000__)`で括られてい
+る部分を参考にしてください．
+
+レジスタウィンドウを持つCPUでは，レジスタウィンドウをスタックにフラッシュするアセンブラコードを追加する必要があるかもしれません．
+
+## 配布条件
+
+[COPYING.ja](COPYING.ja) ファイルを参照してください．
+
+## フィードバック
+
+Rubyに関する質問は Ruby-Talk（英語）や Ruby-List（日本語） (https://www.ruby-lang.org/ja/community/mailing-lists) や，
+stackoverflow (https://ja.stackoverflow.com/) などのWebサイトに投稿してください．
+
+バグ報告は https://bugs.ruby-lang.org で受け付けています．
+
+
+## 著者
+
+Rubyのオリジナル版は，1995年にまつもとゆきひろ氏によって設計・開発されました．
+
+<mailto:matz@ruby-lang.org>
diff --git a/README.jp b/README.jp
deleted file mode 100644
index d137a435d8..0000000000
--- a/README.jp
+++ /dev/null
@@ -1,175 +0,0 @@
-* Ruby�Ȥ�
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-     root�Ǻ�Ȥ���ɬ�פ����뤫�⤷��ޤ���
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-     ͳ���ѹ��Ǥ��ޤ���
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--------------------------------------------------------
-created at: Thu Aug  3 11:57:36 JST 1995
-Local variables:
-mode: indented-text
-end:
diff --git a/README.md b/README.md
new file mode 100644
index 0000000000..bd7c7813a7
--- /dev/null
+++ b/README.md
@@ -0,0 +1,173 @@
+[![Build Status](https://travis-ci.org/ruby/ruby.svg?branch=master)](https://travis-ci.org/ruby/ruby)
+[![Build status](https://ci.appveyor.com/api/projects/status/0sy8rrxut4o0k960/branch/master?svg=true)](https://ci.appveyor.com/project/ruby/ruby/branch/master)
+[![Actions Status](https://github.com/ruby/ruby/workflows/macOS/badge.svg)](https://github.com/ruby/ruby/actions?query=workflow%3A"macOS")
+[![Actions Status](https://github.com/ruby/ruby/workflows/MinGW/badge.svg)](https://github.com/ruby/ruby/actions?query=workflow%3A"MinGW")
+[![Actions Status](https://github.com/ruby/ruby/workflows/MJIT/badge.svg)](https://github.com/ruby/ruby/actions?query=workflow%3A"MJIT")
+[![Actions Status](https://github.com/ruby/ruby/workflows/Ubuntu/badge.svg)](https://github.com/ruby/ruby/actions?query=workflow%3A"Ubuntu")
+[![Actions Status](https://github.com/ruby/ruby/workflows/Windows/badge.svg)](https://github.com/ruby/ruby/actions?query=workflow%3A"Windows")
+
+# What's Ruby
+
+Ruby is an interpreted object-oriented programming language often
+used for web development. It also offers many scripting features
+to process plain text and serialized files, or manage system tasks.
+It is simple, straightforward, and extensible.
+
+## Features of Ruby
+
+*   Simple Syntax
+*   **Normal** Object-oriented Features (e.g. class, method calls)
+*   **Advanced** Object-oriented Features (e.g. mix-in, singleton-method)
+*   Operator Overloading
+*   Exception Handling
+*   Iterators and Closures
+*   Garbage Collection
+*   Dynamic Loading of Object Files (on some architectures)
+*   Highly Portable (works on many Unix-like/POSIX compatible platforms as
+    well as Windows, macOS, etc.) cf.
+    https://github.com/ruby/ruby/blob/master/doc/contributing.rdoc#label-Platform+Maintainers
+
+
+## How to get Ruby
+
+For a complete list of ways to install Ruby, including using third-party tools
+like rvm, see:
+
+https://www.ruby-lang.org/en/downloads/
+
+### Git
+
+The mirror of the Ruby source tree can be checked out with the following command:
+
+    $ git clone https://github.com/ruby/ruby.git
+
+There are some other branches under development. Try the following command
+to see the list of branches:
+
+    $ git ls-remote https://github.com/ruby/ruby.git
+
+You may also want to use https://git.ruby-lang.org/ruby.git (actual master of Ruby source)
+if you are a committer.
+
+### Subversion
+
+Stable branches for older Ruby versions can be checked out with also the
+following command:
+
+    $ svn co https://svn.ruby-lang.org/repos/ruby/branches/ruby_2_6/ ruby
+
+Try the following command to see the list of branches:
+
+    $ svn ls https://svn.ruby-lang.org/repos/ruby/branches/
+
+
+## Ruby home page
+
+https://www.ruby-lang.org/
+
+## Mailing list
+
+There is a mailing list to discuss Ruby. To subscribe to this list, please
+send the following phrase:
+
+    subscribe
+
+in the mail body (not subject) to the address [ruby-talk-request@ruby-lang.org].
+
+[ruby-talk-request@ruby-lang.org]: mailto:ruby-talk-request@ruby-lang.org?subject=Join%20Ruby%20Mailing%20List&body=subscribe
+
+## How to compile and install
+
+1.  If you want to use Microsoft Visual C++ to compile Ruby, read
+    [win32/README.win32](win32/README.win32) instead of this document.
+
+2.  Run `./autogen.sh` to generate configure, when you build the source checked
+    out from the Git repository.
+
+3.  Run `./configure`, which will generate `config.h` and `Makefile`.
+
+    Some C compiler flags may be added by default depending on your
+    environment. Specify `optflags=..` and `warnflags=..` as necessary to
+    override them.
+
+4.  Edit `include/ruby/defines.h` if you need. Usually this step will not be needed.
+
+5.  Remove comment mark(`#`) before the module names from `ext/Setup` (or add
+    module names if not present), if you want to link modules statically.
+
+    If you don't want to compile non static extension modules (probably on
+    architectures which do not allow dynamic loading), remove comment mark
+    from the line "`#option nodynamic`" in `ext/Setup`.
+
+    Usually this step will not be needed.
+
+6.  Run `make`.
+
+    * On Mac, set RUBY\_CODESIGN environment variable with a signing identity.
+      It uses the identity to sign `ruby` binary. See also codesign(1).
+
+7.  Optionally, run '`make check`' to check whether the compiled Ruby
+    interpreter works well. If you see the message "`check succeeded`", your
+    Ruby works as it should (hopefully).
+
+8.  Run '`make install`'.
+
+    This command will create the following directories and install files into
+    them.
+
+    *   `${DESTDIR}${prefix}/bin`
+    *   `${DESTDIR}${prefix}/include/ruby-${MAJOR}.${MINOR}.${TEENY}`
+    *   `${DESTDIR}${prefix}/include/ruby-${MAJOR}.${MINOR}.${TEENY}/${PLATFORM}`
+    *   `${DESTDIR}${prefix}/lib`
+    *   `${DESTDIR}${prefix}/lib/ruby`
+    *   `${DESTDIR}${prefix}/lib/ruby/${MAJOR}.${MINOR}.${TEENY}`
+    *   `${DESTDIR}${prefix}/lib/ruby/${MAJOR}.${MINOR}.${TEENY}/${PLATFORM}`
+    *   `${DESTDIR}${prefix}/lib/ruby/site_ruby`
+    *   `${DESTDIR}${prefix}/lib/ruby/site_ruby/${MAJOR}.${MINOR}.${TEENY}`
+    *   `${DESTDIR}${prefix}/lib/ruby/site_ruby/${MAJOR}.${MINOR}.${TEENY}/${PLATFORM}`
+    *   `${DESTDIR}${prefix}/lib/ruby/vendor_ruby`
+    *   `${DESTDIR}${prefix}/lib/ruby/vendor_ruby/${MAJOR}.${MINOR}.${TEENY}`
+    *   `${DESTDIR}${prefix}/lib/ruby/vendor_ruby/${MAJOR}.${MINOR}.${TEENY}/${PLATFORM}`
+    *   `${DESTDIR}${prefix}/lib/ruby/gems/${MAJOR}.${MINOR}.${TEENY}`
+    *   `${DESTDIR}${prefix}/share/man/man1`
+    *   `${DESTDIR}${prefix}/share/ri/${MAJOR}.${MINOR}.${TEENY}/system`
+
+
+    If Ruby's API version is '*x.y.z*', the `${MAJOR}` is '*x*', the
+    `${MINOR}` is '*y*', and the `${TEENY}` is '*z*'.
+
+    **NOTE**: teeny of the API version may be different from one of Ruby's
+    program version
+
+    You may have to be a super user to install Ruby.
+
+If you fail to compile Ruby, please send the detailed error report with the
+error log and machine/OS type, to help others.
+
+Some extension libraries may not get compiled because of lack of necessary
+external libraries and/or headers, then you will need to run '`make distclean-ext`'
+to remove old configuration after installing them in such case.
+
+## Copying
+
+See the file [COPYING](COPYING).
+
+## Feedback
+
+Questions about the Ruby language can be asked on the Ruby-Talk mailing list
+(https://www.ruby-lang.org/en/community/mailing-lists) or on websites like
+(https://stackoverflow.com).
+
+Bugs should be reported at https://bugs.ruby-lang.org. Read [HowToReport] for more information.
+
+[HowToReport]: https://bugs.ruby-lang.org/projects/ruby/wiki/HowToReport
+
+## Contributing
+
+See the file [CONTRIBUTING.md](CONTRIBUTING.md)
+
+## The Author
+
+Ruby was originally designed and developed by Yukihiro Matsumoto (Matz) in 1995.
+
+<matz@ruby-lang.org>
diff --git a/ToDo b/ToDo
deleted file mode 100644
index 7f20c28ed3..0000000000
--- a/ToDo
+++ /dev/null
@@ -1,38 +0,0 @@
-Language Spec.
-
-* package or access control for global variables
-* named arguments like foo(nation:="german" or nation: "german").
-* method to retrieve argument information (need new C API)
-* multiple return values, yield values.  maybe imcompatible
-* cascading method invocation.
-
-Hacking Interpreter
-
-* non-blocking open (e.g. named pipe) for thread
-* avoid blocking with gethostbyname/gethostbyaddr
-* objectify interpreters
-* remove rb_eval() recursions
-* syntax tree -> bytecode ???
-* scrambled script, or script filter
-
-Extension Libraries
-
-* mod_ruby, FastCGI ruby
-* InterBase module
-* ptk.rb pTk wrapper that is compatible to tk.rb
-
-Ruby Libraries
-
-* CGI.rb
-* httplib.rb, urllib.rb, nttplib.rb, etc.
-* format like perl's
-
-Tools
-
-* extension library maker like XS or SWIG
-* freeze or undump to bundle everything
-
-Misc
-
-* translate README.EXT fully into English
-* publish Ruby books
diff --git a/aclocal.m4 b/aclocal.m4
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/aclocal.m4
diff --git a/addr2line.c b/addr2line.c
new file mode 100644
index 0000000000..0029cffbca
--- /dev/null
+++ b/addr2line.c
@@ -0,0 +1,2723 @@
+/**********************************************************************
+
+  addr2line.c -
+
+  $Author$
+
+  Copyright (C) 2010 Shinichiro Hamaji
+
+**********************************************************************/
+
+#if defined(__clang__)
+#pragma clang diagnostic ignored "-Wgnu-empty-initializer"
+#pragma clang diagnostic ignored "-Wgcc-compat"
+#endif
+
+#include "ruby/internal/config.h"
+#include "ruby/defines.h"
+#include "ruby/missing.h"
+#include "addr2line.h"
+
+#include <stdio.h>
+#include <errno.h>
+
+#ifdef HAVE_LIBPROC_H
+#include <libproc.h>
+#endif
+
+#include "ruby/internal/stdbool.h"
+
+#if defined(USE_ELF) || defined(HAVE_MACH_O_LOADER_H)
+
+#include <fcntl.h>
+#include <limits.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/mman.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+/* Make alloca work the best possible way.  */
+#ifdef __GNUC__
+# ifndef alloca
+#  define alloca __builtin_alloca
+# endif
+#else
+# ifdef HAVE_ALLOCA_H
+#  include <alloca.h>
+# else
+#  ifdef _AIX
+#pragma alloca
+#  else
+#   ifndef alloca		/* predefined by HP cc +Olibcalls */
+void *alloca();
+#   endif
+#  endif /* AIX */
+# endif	/* HAVE_ALLOCA_H */
+#endif /* __GNUC__ */
+
+#ifdef HAVE_DLADDR
+# include <dlfcn.h>
+#endif
+
+#ifdef HAVE_MACH_O_LOADER_H
+# include <crt_externs.h>
+# include <mach-o/fat.h>
+# include <mach-o/loader.h>
+# include <mach-o/nlist.h>
+# include <mach-o/stab.h>
+#endif
+
+#ifdef USE_ELF
+# ifdef __OpenBSD__
+#  include <elf_abi.h>
+# else
+#  include <elf.h>
+# endif
+
+#ifndef ElfW
+# if SIZEOF_VOIDP == 8
+#  define ElfW(x) Elf64##_##x
+# else
+#  define ElfW(x) Elf32##_##x
+# endif
+#endif
+#ifndef ELF_ST_TYPE
+# if SIZEOF_VOIDP == 8
+#  define ELF_ST_TYPE ELF64_ST_TYPE
+# else
+#  define ELF_ST_TYPE ELF32_ST_TYPE
+# endif
+#endif
+#endif
+
+#ifdef SHF_COMPRESSED
+# if defined(ELFCOMPRESS_ZLIB) && defined(HAVE_LIBZ)
+   /* FreeBSD 11.0 lacks ELFCOMPRESS_ZLIB */
+#  include <zlib.h>
+#  define SUPPORT_COMPRESSED_DEBUG_LINE
+# endif
+#else /* compatibility with glibc < 2.22 */
+# define SHF_COMPRESSED 0
+#endif
+
+#ifndef PATH_MAX
+#define PATH_MAX 4096
+#endif
+
+#define DW_LNS_copy                     0x01
+#define DW_LNS_advance_pc               0x02
+#define DW_LNS_advance_line             0x03
+#define DW_LNS_set_file                 0x04
+#define DW_LNS_set_column               0x05
+#define DW_LNS_negate_stmt              0x06
+#define DW_LNS_set_basic_block          0x07
+#define DW_LNS_const_add_pc             0x08
+#define DW_LNS_fixed_advance_pc         0x09
+#define DW_LNS_set_prologue_end         0x0a /* DWARF3 */
+#define DW_LNS_set_epilogue_begin       0x0b /* DWARF3 */
+#define DW_LNS_set_isa                  0x0c /* DWARF3 */
+
+/* Line number extended opcode name. */
+#define DW_LNE_end_sequence             0x01
+#define DW_LNE_set_address              0x02
+#define DW_LNE_define_file              0x03
+#define DW_LNE_set_discriminator        0x04  /* DWARF4 */
+
+PRINTF_ARGS(static int kprintf(const char *fmt, ...), 1, 2);
+
+typedef struct line_info {
+    const char *dirname;
+    const char *filename;
+    const char *path; /* object path */
+    int line;
+
+    uintptr_t base_addr;
+    uintptr_t saddr;
+    const char *sname; /* function name */
+
+    struct line_info *next;
+} line_info_t;
+
+struct dwarf_section {
+    char *ptr;
+    size_t size;
+    uint64_t flags;
+};
+
+typedef struct obj_info {
+    const char *path; /* object path */
+    char *mapped;
+    size_t mapped_size;
+    void *uncompressed;
+    uintptr_t base_addr;
+    uintptr_t vmaddr;
+    struct dwarf_section debug_abbrev;
+    struct dwarf_section debug_info;
+    struct dwarf_section debug_line;
+    struct dwarf_section debug_ranges;
+    struct dwarf_section debug_str;
+    struct obj_info *next;
+} obj_info_t;
+
+#define DWARF_SECTION_COUNT 5
+
+static struct dwarf_section *
+obj_dwarf_section_at(obj_info_t *obj, int n)
+{
+    struct dwarf_section *ary[] = {
+        &obj->debug_abbrev,
+        &obj->debug_info,
+        &obj->debug_line,
+        &obj->debug_ranges,
+        &obj->debug_str
+    };
+    if (n < 0 || DWARF_SECTION_COUNT <= n) {
+        abort();
+    }
+    return ary[n];
+}
+
+struct debug_section_definition {
+    const char *name;
+    struct dwarf_section *dwarf;
+};
+
+/* Avoid consuming stack as this module may be used from signal handler */
+static char binary_filename[PATH_MAX + 1];
+
+static unsigned long
+uleb128(char **p)
+{
+    unsigned long r = 0;
+    int s = 0;
+    for (;;) {
+	unsigned char b = *(unsigned char *)(*p)++;
+	if (b < 0x80) {
+	    r += (unsigned long)b << s;
+	    break;
+	}
+	r += (b & 0x7f) << s;
+	s += 7;
+    }
+    return r;
+}
+
+static long
+sleb128(char **p)
+{
+    long r = 0;
+    int s = 0;
+    for (;;) {
+	unsigned char b = *(unsigned char *)(*p)++;
+	if (b < 0x80) {
+	    if (b & 0x40) {
+		r -= (0x80 - b) << s;
+	    }
+	    else {
+		r += (b & 0x3f) << s;
+	    }
+	    break;
+	}
+	r += (b & 0x7f) << s;
+	s += 7;
+    }
+    return r;
+}
+
+static const char *
+get_nth_dirname(unsigned long dir, char *p)
+{
+    if (!dir--) {
+	return "";
+    }
+    while (dir--) {
+	while (*p) p++;
+	p++;
+	if (!*p) {
+	    kprintf("Unexpected directory number %lu in %s\n",
+		    dir, binary_filename);
+	    return "";
+	}
+    }
+    return p;
+}
+
+static void
+fill_filename(int file, char *include_directories, char *filenames, line_info_t *line, obj_info_t *obj)
+{
+    int i;
+    char *p = filenames;
+    char *filename;
+    unsigned long dir;
+    for (i = 1; i <= file; i++) {
+	filename = p;
+	if (!*p) {
+	    /* Need to output binary file name? */
+	    kprintf("Unexpected file number %d in %s at %tx\n",
+		    file, binary_filename, filenames - obj->mapped);
+	    return;
+	}
+	while (*p) p++;
+	p++;
+	dir = uleb128(&p);
+	/* last modified. */
+	uleb128(&p);
+	/* size of the file. */
+	uleb128(&p);
+
+	if (i == file) {
+	    line->filename = filename;
+	    line->dirname = get_nth_dirname(dir, include_directories);
+	}
+    }
+}
+
+static void
+fill_line(int num_traces, void **traces, uintptr_t addr, int file, int line,
+	  char *include_directories, char *filenames,
+	  obj_info_t *obj, line_info_t *lines, int offset)
+{
+    int i;
+    addr += obj->base_addr - obj->vmaddr;
+    for (i = offset; i < num_traces; i++) {
+	uintptr_t a = (uintptr_t)traces[i];
+	/* We assume one line code doesn't result >100 bytes of native code.
+       We may want more reliable way eventually... */
+	if (addr < a && a < addr + 100) {
+	    fill_filename(file, include_directories, filenames, &lines[i], obj);
+	    lines[i].line = line;
+	}
+    }
+}
+
+struct LineNumberProgramHeader {
+    uint64_t unit_length;
+    uint16_t version;
+    uint8_t format; /* 4 or 8 */
+    uint64_t header_length;
+    uint8_t minimum_instruction_length;
+    uint8_t maximum_operations_per_instruction;
+    uint8_t default_is_stmt;
+    int8_t line_base;
+    uint8_t line_range;
+    uint8_t opcode_base;
+    /* uint8_t standard_opcode_lengths[opcode_base-1]; */
+    const char *include_directories;
+    const char *filenames;
+    const char *cu_start;
+    const char *cu_end;
+};
+
+static int
+parse_debug_line_header(const char **pp, struct LineNumberProgramHeader *header)
+{
+    const char *p = *pp;
+    header->unit_length = *(uint32_t *)p;
+    p += sizeof(uint32_t);
+
+    header->format = 4;
+    if (header->unit_length == 0xffffffff) {
+	header->unit_length = *(uint64_t *)p;
+	p += sizeof(uint64_t);
+        header->format = 8;
+    }
+
+    header->cu_end = p + header->unit_length;
+
+    header->version = *(uint16_t *)p;
+    p += sizeof(uint16_t);
+    if (header->version > 4) return -1;
+
+    header->header_length = header->format == 4 ? *(uint32_t *)p : *(uint64_t *)p;
+    p += header->format;
+    header->cu_start = p + header->header_length;
+
+    header->minimum_instruction_length = *(uint8_t *)p++;
+
+    if (header->version >= 4) {
+        /* maximum_operations_per_instruction = *(uint8_t *)p; */
+        if (*p != 1) return -1; /* For non-VLIW architectures, this field is 1 */
+        p++;
+    }
+
+    header->default_is_stmt = *(uint8_t *)p++;
+    header->line_base = *(int8_t *)p++;
+    header->line_range = *(uint8_t *)p++;
+    header->opcode_base = *(uint8_t *)p++;
+    /* header->standard_opcode_lengths = (uint8_t *)p - 1; */
+    p += header->opcode_base - 1;
+
+    header->include_directories = p;
+
+    /* temporary measure for compress-debug-sections */
+    if (p >= header->cu_end) return -1;
+
+    /* skip include directories */
+    while (*p) {
+	p = memchr(p, '\0', header->cu_end - p);
+	if (!p) return -1;
+	p++;
+    }
+    p++;
+
+    header->filenames = p;
+
+    *pp = header->cu_start;
+
+    return 0;
+}
+
+static int
+parse_debug_line_cu(int num_traces, void **traces, char **debug_line,
+		obj_info_t *obj, line_info_t *lines, int offset)
+{
+    const char *p = (const char *)*debug_line;
+    struct LineNumberProgramHeader header;
+
+    /* The registers. */
+    unsigned long addr = 0;
+    unsigned int file = 1;
+    unsigned int line = 1;
+    /* unsigned int column = 0; */
+    int is_stmt;
+    /* int basic_block = 0; */
+    /* int end_sequence = 0; */
+    /* int prologue_end = 0; */
+    /* int epilogue_begin = 0; */
+    /* unsigned int isa = 0; */
+
+    if (parse_debug_line_header(&p, &header))
+        return -1;
+    is_stmt = header.default_is_stmt;
+
+#define FILL_LINE()						    \
+    do {							    \
+	fill_line(num_traces, traces, addr, file, line,		    \
+                  (char *)header.include_directories,               \
+                  (char *)header.filenames,                         \
+		  obj, lines, offset);				    \
+	/*basic_block = prologue_end = epilogue_begin = 0;*/	    \
+    } while (0)
+
+    while (p < header.cu_end) {
+	unsigned long a;
+	unsigned char op = *p++;
+	switch (op) {
+	case DW_LNS_copy:
+	    FILL_LINE();
+	    break;
+	case DW_LNS_advance_pc:
+	    a = uleb128((char **)&p);
+	    addr += a;
+	    break;
+	case DW_LNS_advance_line: {
+	    long a = sleb128((char **)&p);
+	    line += a;
+	    break;
+	}
+	case DW_LNS_set_file:
+	    file = (unsigned int)uleb128((char **)&p);
+	    break;
+	case DW_LNS_set_column:
+	    /*column = (unsigned int)*/(void)uleb128((char **)&p);
+	    break;
+	case DW_LNS_negate_stmt:
+	    is_stmt = !is_stmt;
+	    break;
+	case DW_LNS_set_basic_block:
+	    /*basic_block = 1; */
+	    break;
+	case DW_LNS_const_add_pc:
+	    a = ((255UL - header.opcode_base) / header.line_range) *
+		header.minimum_instruction_length;
+	    addr += a;
+	    break;
+	case DW_LNS_fixed_advance_pc:
+	    a = *(uint16_t *)p;
+	    p += sizeof(uint16_t);
+	    addr += a;
+	    break;
+	case DW_LNS_set_prologue_end:
+	    /* prologue_end = 1; */
+	    break;
+	case DW_LNS_set_epilogue_begin:
+	    /* epilogue_begin = 1; */
+	    break;
+	case DW_LNS_set_isa:
+	    /* isa = (unsigned int)*/(void)uleb128((char **)&p);
+	    break;
+	case 0:
+	    a = *(unsigned char *)p++;
+	    op = *p++;
+	    switch (op) {
+	    case DW_LNE_end_sequence:
+		/* end_sequence = 1; */
+		FILL_LINE();
+		addr = 0;
+		file = 1;
+		line = 1;
+		/* column = 0; */
+		is_stmt = header.default_is_stmt;
+		/* end_sequence = 0; */
+		/* isa = 0; */
+		break;
+	    case DW_LNE_set_address:
+		addr = *(unsigned long *)p;
+		p += sizeof(unsigned long);
+		break;
+	    case DW_LNE_define_file:
+		kprintf("Unsupported operation in %s\n",
+			binary_filename);
+		break;
+	    case DW_LNE_set_discriminator:
+		/* TODO:currently ignore */
+		uleb128((char **)&p);
+		break;
+	    default:
+		kprintf("Unknown extended opcode: %d in %s\n",
+			op, binary_filename);
+	    }
+	    break;
+	default: {
+            uint8_t adjusted_opcode = op - header.opcode_base;
+            uint8_t operation_advance = adjusted_opcode / header.line_range;
+            /* NOTE: this code doesn't support VLIW */
+            addr += operation_advance * header.minimum_instruction_length;
+            line += header.line_base + (adjusted_opcode % header.line_range);
+	    FILL_LINE();
+	}
+	}
+    }
+    *debug_line = (char *)p;
+    return 0;
+}
+
+static int
+parse_debug_line(int num_traces, void **traces,
+		 char *debug_line, unsigned long size,
+		 obj_info_t *obj, line_info_t *lines, int offset)
+{
+    char *debug_line_end = debug_line + size;
+    while (debug_line < debug_line_end) {
+	if (parse_debug_line_cu(num_traces, traces, &debug_line, obj, lines, offset))
+	    return -1;
+    }
+    if (debug_line != debug_line_end) {
+	kprintf("Unexpected size of .debug_line in %s\n",
+		binary_filename);
+    }
+    return 0;
+}
+
+/* read file and fill lines */
+static uintptr_t
+fill_lines(int num_traces, void **traces, int check_debuglink,
+	   obj_info_t **objp, line_info_t *lines, int offset);
+
+static void
+append_obj(obj_info_t **objp)
+{
+    obj_info_t *newobj = calloc(1, sizeof(obj_info_t));
+    if (*objp) (*objp)->next = newobj;
+    *objp = newobj;
+}
+
+#ifdef USE_ELF
+/* Ideally we should check 4 paths to follow gnu_debuglink:
+ *
+ *   - /usr/lib/debug/.build-id/ab/cdef1234.debug
+ *   - /usr/bin/ruby.debug
+ *   - /usr/bin/.debug/ruby.debug
+ *   - /usr/lib/debug/usr/bin/ruby.debug.
+ *
+ * but we handle only two cases for now as the two formats are
+ * used by some linux distributions.
+ *
+ * See GDB's info for detail.
+ * https://sourceware.org/gdb/onlinedocs/gdb/Separate-Debug-Files.html
+ */
+
+// check the path pattern of "/usr/lib/debug/usr/bin/ruby.debug"
+static void
+follow_debuglink(const char *debuglink, int num_traces, void **traces,
+		 obj_info_t **objp, line_info_t *lines, int offset)
+{
+    static const char global_debug_dir[] = "/usr/lib/debug";
+    const size_t global_debug_dir_len = sizeof(global_debug_dir) - 1;
+    char *p;
+    obj_info_t *o1 = *objp, *o2;
+    size_t len;
+
+    p = strrchr(binary_filename, '/');
+    if (!p) {
+	return;
+    }
+    p[1] = '\0';
+
+    len = strlen(binary_filename);
+    if (len >= PATH_MAX - global_debug_dir_len)
+	len = PATH_MAX - global_debug_dir_len - 1;
+    memmove(binary_filename + global_debug_dir_len, binary_filename, len);
+    memcpy(binary_filename, global_debug_dir, global_debug_dir_len);
+    len += global_debug_dir_len;
+    strlcpy(binary_filename + len, debuglink, PATH_MAX - len);
+
+    append_obj(objp);
+    o2 = *objp;
+    o2->base_addr = o1->base_addr;
+    o2->path = o1->path;
+    fill_lines(num_traces, traces, 0, objp, lines, offset);
+}
+
+// check the path pattern of "/usr/lib/debug/.build-id/ab/cdef1234.debug"
+static void
+follow_debuglink_build_id(const char *build_id, size_t build_id_size, int num_traces, void **traces,
+                          obj_info_t **objp, line_info_t *lines, int offset)
+{
+    static const char global_debug_dir[] = "/usr/lib/debug/.build-id/";
+    const size_t global_debug_dir_len = sizeof(global_debug_dir) - 1;
+    char *p;
+    obj_info_t *o1 = *objp, *o2;
+    size_t i;
+
+    if (PATH_MAX < global_debug_dir_len + 1 + build_id_size * 2 + 6) return;
+
+    memcpy(binary_filename, global_debug_dir, global_debug_dir_len);
+    p = binary_filename + global_debug_dir_len;
+    for (i = 0; i < build_id_size; i++) {
+        static const char tbl[] = "0123456789abcdef";
+        unsigned char n = build_id[i];
+        *p++ = tbl[n / 16];
+        *p++ = tbl[n % 16];
+        if (i == 0) *p++ = '/';
+    }
+    strcpy(p, ".debug");
+
+    append_obj(objp);
+    o2 = *objp;
+    o2->base_addr = o1->base_addr;
+    o2->path = o1->path;
+    fill_lines(num_traces, traces, 0, objp, lines, offset);
+}
+#endif
+
+enum
+{
+    DW_TAG_compile_unit = 0x11,
+    DW_TAG_inlined_subroutine = 0x1d,
+    DW_TAG_subprogram = 0x2e,
+};
+
+/* Attributes encodings */
+enum
+{
+    DW_AT_sibling = 0x01,
+    DW_AT_location = 0x02,
+    DW_AT_name = 0x03,
+    /* Reserved 0x04 */
+    /* Reserved 0x05 */
+    /* Reserved 0x06 */
+    /* Reserved 0x07 */
+    /* Reserved 0x08 */
+    DW_AT_ordering = 0x09,
+    /* Reserved 0x0a */
+    DW_AT_byte_size = 0x0b,
+    /* Reserved 0x0c */
+    DW_AT_bit_size = 0x0d,
+    /* Reserved 0x0e */
+    /* Reserved 0x0f */
+    DW_AT_stmt_list = 0x10,
+    DW_AT_low_pc = 0x11,
+    DW_AT_high_pc = 0x12,
+    DW_AT_language = 0x13,
+    /* Reserved 0x14 */
+    DW_AT_discr = 0x15,
+    DW_AT_discr_value = 0x16,
+    DW_AT_visibility = 0x17,
+    DW_AT_import = 0x18,
+    DW_AT_string_length = 0x19,
+    DW_AT_common_reference = 0x1a,
+    DW_AT_comp_dir = 0x1b,
+    DW_AT_const_value = 0x1c,
+    DW_AT_containing_type = 0x1d,
+    DW_AT_default_value = 0x1e,
+    /* Reserved 0x1f */
+    DW_AT_inline = 0x20,
+    DW_AT_is_optional = 0x21,
+    DW_AT_lower_bound = 0x22,
+    /* Reserved 0x23 */
+    /* Reserved 0x24 */
+    DW_AT_producer = 0x25,
+    /* Reserved 0x26 */
+    DW_AT_prototyped = 0x27,
+    /* Reserved 0x28 */
+    /* Reserved 0x29 */
+    DW_AT_return_addr = 0x2a,
+    /* Reserved 0x2b */
+    DW_AT_start_scope = 0x2c,
+    /* Reserved 0x2d */
+    DW_AT_bit_stride = 0x2e,
+    DW_AT_upper_bound = 0x2f,
+    /* Reserved 0x30 */
+    DW_AT_abstract_origin = 0x31,
+    DW_AT_accessibility = 0x32,
+    DW_AT_address_class = 0x33,
+    DW_AT_artificial = 0x34,
+    DW_AT_base_types = 0x35,
+    DW_AT_calling_convention = 0x36,
+    DW_AT_count = 0x37,
+    DW_AT_data_member_location = 0x38,
+    DW_AT_decl_column = 0x39,
+    DW_AT_decl_file = 0x3a,
+    DW_AT_decl_line = 0x3b,
+    DW_AT_declaration = 0x3c,
+    DW_AT_discr_list = 0x3d,
+    DW_AT_encoding = 0x3e,
+    DW_AT_external = 0x3f,
+    DW_AT_frame_base = 0x40,
+    DW_AT_friend = 0x41,
+    DW_AT_identifier_case = 0x42,
+    /* Reserved 0x43 */
+    DW_AT_namelist_item = 0x44,
+    DW_AT_priority = 0x45,
+    DW_AT_segment = 0x46,
+    DW_AT_specification = 0x47,
+    DW_AT_static_link = 0x48,
+    DW_AT_type = 0x49,
+    DW_AT_use_location = 0x4a,
+    DW_AT_variable_parameter = 0x4b,
+    DW_AT_virtuality = 0x4c,
+    DW_AT_vtable_elem_location = 0x4d,
+    DW_AT_allocated = 0x4e,
+    DW_AT_associated = 0x4f,
+    DW_AT_data_location = 0x50,
+    DW_AT_byte_stride = 0x51,
+    DW_AT_entry_pc = 0x52,
+    DW_AT_use_UTF8 = 0x53,
+    DW_AT_extension = 0x54,
+    DW_AT_ranges = 0x55,
+    DW_AT_trampoline = 0x56,
+    DW_AT_call_column = 0x57,
+    DW_AT_call_file = 0x58,
+    DW_AT_call_line = 0x59,
+    DW_AT_description = 0x5a,
+    DW_AT_binary_scale = 0x5b,
+    DW_AT_decimal_scale = 0x5c,
+    DW_AT_small = 0x5d,
+    DW_AT_decimal_sign = 0x5e,
+    DW_AT_digit_count = 0x5f,
+    DW_AT_picture_string = 0x60,
+    DW_AT_mutable = 0x61,
+    DW_AT_threads_scaled = 0x62,
+    DW_AT_explicit = 0x63,
+    DW_AT_object_pointer = 0x64,
+    DW_AT_endianity = 0x65,
+    DW_AT_elemental = 0x66,
+    DW_AT_pure = 0x67,
+    DW_AT_recursive = 0x68,
+    DW_AT_signature = 0x69,
+    DW_AT_main_subprogram = 0x6a,
+    DW_AT_data_bit_offset = 0x6b,
+    DW_AT_const_expr = 0x6c,
+    DW_AT_enum_class = 0x6d,
+    DW_AT_linkage_name = 0x6e,
+    DW_AT_string_length_bit_size = 0x6f,
+    DW_AT_string_length_byte_size = 0x70,
+    DW_AT_rank = 0x71,
+    DW_AT_str_offsets_base = 0x72,
+    DW_AT_addr_base = 0x73,
+    DW_AT_rnglists_base = 0x74,
+    /* Reserved 0x75 */
+    DW_AT_dwo_name = 0x76,
+    DW_AT_reference = 0x77,
+    DW_AT_rvalue_reference = 0x78,
+    DW_AT_macros = 0x79,
+    DW_AT_call_all_calls = 0x7a,
+    DW_AT_call_all_source_calls = 0x7b,
+    DW_AT_call_all_tail_calls = 0x7c,
+    DW_AT_call_return_pc = 0x7d,
+    DW_AT_call_value = 0x7e,
+    DW_AT_call_origin = 0x7f,
+    DW_AT_call_parameter = 0x80,
+    DW_AT_call_pc = 0x81,
+    DW_AT_call_tail_call = 0x82,
+    DW_AT_call_target = 0x83,
+    DW_AT_call_target_clobbered = 0x84,
+    DW_AT_call_data_location = 0x85,
+    DW_AT_call_data_value = 0x86,
+    DW_AT_noreturn = 0x87,
+    DW_AT_alignment = 0x88,
+    DW_AT_export_symbols = 0x89,
+    DW_AT_deleted = 0x8a,
+    DW_AT_defaulted = 0x8b,
+    DW_AT_loclists_base = 0x8c,
+    DW_AT_lo_user = 0x2000,
+    DW_AT_hi_user = 0x3fff
+};
+
+/* Attribute form encodings */
+enum
+{
+    DW_FORM_addr = 0x01,
+    /* Reserved 0x02 */
+    DW_FORM_block2 = 0x03,
+    DW_FORM_block4 = 0x04,
+    DW_FORM_data2 = 0x05,
+    DW_FORM_data4 = 0x06,
+    DW_FORM_data8 = 0x07,
+    DW_FORM_string = 0x08,
+    DW_FORM_block = 0x09,
+    DW_FORM_block1 = 0x0a,
+    DW_FORM_data1 = 0x0b,
+    DW_FORM_flag = 0x0c,
+    DW_FORM_sdata = 0x0d,
+    DW_FORM_strp = 0x0e,
+    DW_FORM_udata = 0x0f,
+    DW_FORM_ref_addr = 0x10,
+    DW_FORM_ref1 = 0x11,
+    DW_FORM_ref2 = 0x12,
+    DW_FORM_ref4 = 0x13,
+    DW_FORM_ref8 = 0x14,
+    DW_FORM_ref_udata = 0x15,
+    DW_FORM_indirect = 0x16,
+    DW_FORM_sec_offset = 0x17,
+    DW_FORM_exprloc = 0x18,
+    DW_FORM_flag_present = 0x19,
+    DW_FORM_strx = 0x1a,
+    DW_FORM_addrx = 0x1b,
+    DW_FORM_ref_sup4 = 0x1c,
+    DW_FORM_strp_sup = 0x1d,
+    DW_FORM_data16 = 0x1e,
+    DW_FORM_line_strp = 0x1f,
+    DW_FORM_ref_sig8 = 0x20,
+    DW_FORM_implicit_const = 0x21,
+    DW_FORM_loclistx = 0x22,
+    DW_FORM_rnglistx = 0x23,
+    DW_FORM_ref_sup8 = 0x24,
+    DW_FORM_strx1 = 0x25,
+    DW_FORM_strx2 = 0x26,
+    DW_FORM_strx3 = 0x27,
+    DW_FORM_strx4 = 0x28,
+    DW_FORM_addrx1 = 0x29,
+    DW_FORM_addrx2 = 0x2a,
+    DW_FORM_addrx3 = 0x2b,
+    DW_FORM_addrx4 = 0x2c
+};
+
+enum {
+    VAL_none = 0,
+    VAL_cstr = 1,
+    VAL_data = 2,
+    VAL_uint = 3,
+    VAL_int = 4
+};
+
+# define ABBREV_TABLE_SIZE 256
+typedef struct {
+    obj_info_t *obj;
+    char *file;
+    char *current_cu;
+    uint64_t current_low_pc;
+    char *debug_line_cu_end;
+    char *debug_line_files;
+    char *debug_line_directories;
+    char *p;
+    char *cu_end;
+    char *pend;
+    char *q0;
+    char *q;
+    int format; // 4 or 8
+    uint8_t address_size;
+    int level;
+    char *abbrev_table[ABBREV_TABLE_SIZE];
+} DebugInfoReader;
+
+typedef struct {
+    ptrdiff_t pos;
+    int tag;
+    int has_children;
+} DIE;
+
+typedef struct {
+    union {
+        char *ptr;
+        uint64_t uint64;
+        int64_t int64;
+    } as;
+    uint64_t off;
+    uint64_t at;
+    uint64_t form;
+    size_t size;
+    int type;
+} DebugInfoValue;
+
+/* TODO: Big Endian */
+#define MERGE_2INTS(a,b,sz) (((uint64_t)(b)<<sz)|(a))
+
+static uint16_t
+get_uint16(const uint8_t *p)
+{
+    return (uint16_t)MERGE_2INTS(p[0],p[1],8);
+}
+
+static uint32_t
+get_uint32(const uint8_t *p)
+{
+    return (uint32_t)MERGE_2INTS(get_uint16(p),get_uint16(p+2),16);
+}
+
+static uint64_t
+get_uint64(const uint8_t *p)
+{
+    return MERGE_2INTS(get_uint32(p),get_uint32(p+4),32);
+}
+
+static uint8_t
+read_uint8(char **ptr)
+{
+    const unsigned char *p = (const unsigned char *)*ptr;
+    *ptr = (char *)(p + 1);
+    return *p;
+}
+
+static uint16_t
+read_uint16(char **ptr)
+{
+    const unsigned char *p = (const unsigned char *)*ptr;
+    *ptr = (char *)(p + 2);
+    return get_uint16(p);
+}
+
+static uint32_t
+read_uint24(char **ptr)
+{
+    const unsigned char *p = (const unsigned char *)*ptr;
+    *ptr = (char *)(p + 3);
+    return (*p << 16) | get_uint16(p+1);
+}
+
+static uint32_t
+read_uint32(char **ptr)
+{
+    const unsigned char *p = (const unsigned char *)*ptr;
+    *ptr = (char *)(p + 4);
+    return get_uint32(p);
+}
+
+static uint64_t
+read_uint64(char **ptr)
+{
+    const unsigned char *p = (const unsigned char *)*ptr;
+    *ptr = (char *)(p + 8);
+    return get_uint64(p);
+}
+
+static uintptr_t
+read_uintptr(char **ptr)
+{
+    const unsigned char *p = (const unsigned char *)*ptr;
+    *ptr = (char *)(p + SIZEOF_VOIDP);
+#if SIZEOF_VOIDP == 8
+    return get_uint64(p);
+#else
+    return get_uint32(p);
+#endif
+}
+
+static uint64_t
+read_uint(DebugInfoReader *reader)
+{
+    if (reader->format == 4) {
+        return read_uint32(&reader->p);
+    } else { /* 64 bit */
+        return read_uint64(&reader->p);
+    }
+}
+
+static uint64_t
+read_uleb128(DebugInfoReader *reader)
+{
+    return uleb128(&reader->p);
+}
+
+static int64_t
+read_sleb128(DebugInfoReader *reader)
+{
+    return sleb128(&reader->p);
+}
+
+static void
+debug_info_reader_init(DebugInfoReader *reader, obj_info_t *obj)
+{
+    reader->file = obj->mapped;
+    reader->obj = obj;
+    reader->p = obj->debug_info.ptr;
+    reader->pend = obj->debug_info.ptr + obj->debug_info.size;
+    reader->debug_line_cu_end = obj->debug_line.ptr;
+    reader->current_low_pc = 0;
+}
+
+static void
+di_read_debug_abbrev_cu(DebugInfoReader *reader)
+{
+    uint64_t prev = 0;
+    char *p = reader->q0;
+    for (;;) {
+        uint64_t abbrev_number = uleb128(&p);
+        if (abbrev_number <= prev) break;
+        if (abbrev_number < ABBREV_TABLE_SIZE) {
+            reader->abbrev_table[abbrev_number] = p;
+        }
+        prev = abbrev_number;
+        uleb128(&p); /* tag */
+        p++; /* has_children */
+        /* skip content */
+        for (;;) {
+            uint64_t at = uleb128(&p);
+            uint64_t form = uleb128(&p);
+            if (!at && !form) break;
+        }
+    }
+}
+
+static int
+di_read_debug_line_cu(DebugInfoReader *reader)
+{
+    const char *p;
+    struct LineNumberProgramHeader header;
+
+    p = (const char *)reader->debug_line_cu_end;
+    if (parse_debug_line_header(&p, &header))
+        return -1;
+
+    reader->debug_line_cu_end = (char *)header.cu_end;
+    reader->debug_line_directories = (char *)header.include_directories;
+    reader->debug_line_files = (char *)header.filenames;
+
+    return 0;
+}
+
+static void
+set_uint_value(DebugInfoValue *v, uint64_t n)
+{
+    v->as.uint64 = n;
+    v->type = VAL_uint;
+}
+
+static void
+set_int_value(DebugInfoValue *v, int64_t n)
+{
+    v->as.int64 = n;
+    v->type = VAL_int;
+}
+
+static void
+set_cstr_value(DebugInfoValue *v, char *s)
+{
+    v->as.ptr = s;
+    v->off = 0;
+    v->type = VAL_cstr;
+}
+
+static void
+set_cstrp_value(DebugInfoValue *v, char *s, uint64_t off)
+{
+    v->as.ptr = s;
+    v->off = off;
+    v->type = VAL_cstr;
+}
+
+static void
+set_data_value(DebugInfoValue *v, char *s)
+{
+    v->as.ptr = s;
+    v->type = VAL_data;
+}
+
+static const char *
+get_cstr_value(DebugInfoValue *v)
+{
+    if (v->as.ptr) {
+        return v->as.ptr + v->off;
+    } else {
+        return NULL;
+    }
+}
+
+static void
+debug_info_reader_read_value(DebugInfoReader *reader, uint64_t form, DebugInfoValue *v)
+{
+    switch (form) {
+      case DW_FORM_addr:
+        if (reader->address_size == 4) {
+            set_uint_value(v, read_uint32(&reader->p));
+        } else if (reader->address_size == 8) {
+            set_uint_value(v, read_uint64(&reader->p));
+        } else {
+            fprintf(stderr,"unknown address_size:%d", reader->address_size);
+            abort();
+        }
+        break;
+      case DW_FORM_block2:
+        v->size = read_uint16(&reader->p);
+        set_data_value(v, reader->p);
+        reader->p += v->size;
+        break;
+      case DW_FORM_block4:
+        v->size = read_uint32(&reader->p);
+        set_data_value(v, reader->p);
+        reader->p += v->size;
+        break;
+      case DW_FORM_data2:
+        set_uint_value(v, read_uint16(&reader->p));
+        break;
+      case DW_FORM_data4:
+        set_uint_value(v, read_uint32(&reader->p));
+        break;
+      case DW_FORM_data8:
+        set_uint_value(v, read_uint64(&reader->p));
+        break;
+      case DW_FORM_string:
+        v->size = strlen(reader->p);
+        set_cstr_value(v, reader->p);
+        reader->p += v->size + 1;
+        break;
+      case DW_FORM_block:
+        v->size = uleb128(&reader->p);
+        set_data_value(v, reader->p);
+        reader->p += v->size;
+        break;
+      case DW_FORM_block1:
+        v->size = read_uint8(&reader->p);
+        set_data_value(v, reader->p);
+        reader->p += v->size;
+        break;
+      case DW_FORM_data1:
+        set_uint_value(v, read_uint8(&reader->p));
+        break;
+      case DW_FORM_flag:
+        set_uint_value(v, read_uint8(&reader->p));
+        break;
+      case DW_FORM_sdata:
+        set_int_value(v, read_sleb128(reader));
+        break;
+      case DW_FORM_strp:
+        set_cstrp_value(v, reader->obj->debug_str.ptr, read_uint(reader));
+        break;
+      case DW_FORM_udata:
+        set_uint_value(v, read_uleb128(reader));
+        break;
+      case DW_FORM_ref_addr:
+        if (reader->address_size == 4) {
+            set_uint_value(v, read_uint32(&reader->p));
+        } else if (reader->address_size == 8) {
+            set_uint_value(v, read_uint64(&reader->p));
+        } else {
+            fprintf(stderr,"unknown address_size:%d", reader->address_size);
+            abort();
+        }
+        break;
+      case DW_FORM_ref1:
+        set_uint_value(v, read_uint8(&reader->p));
+        break;
+      case DW_FORM_ref2:
+        set_uint_value(v, read_uint16(&reader->p));
+        break;
+      case DW_FORM_ref4:
+        set_uint_value(v, read_uint32(&reader->p));
+        break;
+      case DW_FORM_ref8:
+        set_uint_value(v, read_uint64(&reader->p));
+        break;
+      case DW_FORM_ref_udata:
+        set_uint_value(v, uleb128(&reader->p));
+        break;
+      case DW_FORM_indirect:
+        /* TODO: read the referred value */
+        set_uint_value(v, uleb128(&reader->p));
+        break;
+      case DW_FORM_sec_offset:
+        set_uint_value(v, read_uint(reader)); /* offset */
+        /* addrptr: debug_addr */
+        /* lineptr: debug_line */
+        /* loclist: debug_loclists */
+        /* loclistptr: debug_loclists */
+        /* macptr: debug_macro */
+        /* rnglist: debug_rnglists */
+        /* rnglistptr: debug_rnglists */
+        /* stroffsetsptr: debug_str_offsets */
+        break;
+      case DW_FORM_exprloc:
+        v->size = (size_t)read_uleb128(reader);
+        set_data_value(v, reader->p);
+        reader->p += v->size;
+        break;
+      case DW_FORM_flag_present:
+        set_uint_value(v, 1);
+        break;
+      case DW_FORM_strx:
+        set_uint_value(v, uleb128(&reader->p));
+        break;
+      case DW_FORM_addrx:
+        /* TODO: read .debug_addr */
+        set_uint_value(v, uleb128(&reader->p));
+        break;
+      case DW_FORM_ref_sup4:
+        set_uint_value(v, read_uint32(&reader->p));
+        break;
+      case DW_FORM_strp_sup:
+        set_uint_value(v, read_uint(reader));
+        /* *p = reader->sup_file + reader->sup_str->sh_offset + ret; */
+        break;
+      case DW_FORM_data16:
+        v->size = 16;
+        set_data_value(v, reader->p);
+        reader->p += v->size;
+        break;
+      case DW_FORM_line_strp:
+        set_uint_value(v, read_uint(reader));
+        /* *p = reader->file + reader->line->sh_offset + ret; */
+        break;
+      case DW_FORM_ref_sig8:
+        set_uint_value(v, read_uint64(&reader->p));
+        break;
+      case DW_FORM_implicit_const:
+        set_int_value(v, sleb128(&reader->q));
+        break;
+      case DW_FORM_loclistx:
+        set_uint_value(v, read_uleb128(reader));
+        break;
+      case DW_FORM_rnglistx:
+        set_uint_value(v, read_uleb128(reader));
+        break;
+      case DW_FORM_ref_sup8:
+        set_uint_value(v, read_uint64(&reader->p));
+        break;
+      case DW_FORM_strx1:
+        set_uint_value(v, read_uint8(&reader->p));
+        break;
+      case DW_FORM_strx2:
+        set_uint_value(v, read_uint16(&reader->p));
+        break;
+      case DW_FORM_strx3:
+        set_uint_value(v, read_uint24(&reader->p));
+        break;
+      case DW_FORM_strx4:
+        set_uint_value(v, read_uint32(&reader->p));
+        break;
+      case DW_FORM_addrx1:
+        set_uint_value(v, read_uint8(&reader->p));
+        break;
+      case DW_FORM_addrx2:
+        set_uint_value(v, read_uint16(&reader->p));
+        break;
+      case DW_FORM_addrx3:
+        set_uint_value(v, read_uint24(&reader->p));
+        break;
+      case DW_FORM_addrx4:
+        set_uint_value(v, read_uint32(&reader->p));
+        break;
+      case 0:
+        goto fail;
+        break;
+    }
+    return;
+
+  fail:
+    fprintf(stderr, "%d: unsupported form: %#"PRIx64"\n", __LINE__, form);
+    exit(1);
+}
+
+/* find abbrev in current compilation unit */
+static char *
+di_find_abbrev(DebugInfoReader *reader, uint64_t abbrev_number)
+{
+    char *p;
+    if (abbrev_number < ABBREV_TABLE_SIZE) {
+        return reader->abbrev_table[abbrev_number];
+    }
+    p = reader->abbrev_table[ABBREV_TABLE_SIZE-1];
+    /* skip 255th record */
+    uleb128(&p); /* tag */
+    p++; /* has_children */
+    /* skip content */
+    for (;;) {
+        uint64_t at = uleb128(&p);
+        uint64_t form = uleb128(&p);
+        if (!at && !form) break;
+    }
+    for (uint64_t n = uleb128(&p); abbrev_number != n; n = uleb128(&p)) {
+        if (n == 0) {
+            fprintf(stderr,"%d: Abbrev Number %"PRId64" not found\n",__LINE__, abbrev_number);
+            exit(1);
+        }
+        uleb128(&p); /* tag */
+        p++; /* has_children */
+        /* skip content */
+        for (;;) {
+            uint64_t at = uleb128(&p);
+            uint64_t form = uleb128(&p);
+            if (!at && !form) break;
+        }
+    }
+    return p;
+}
+
+#if 0
+static void
+hexdump0(const unsigned char *p, size_t n)
+{
+    size_t i;
+    fprintf(stderr, "     0  1  2  3  4  5  6  7  8  9  A  B  C  D  E  F\n");
+    for (i=0; i < n; i++){
+        switch (i & 15) {
+          case 0:
+            fprintf(stderr, "%02zd: %02X ", i/16, p[i]);
+            break;
+          case 15:
+            fprintf(stderr, "%02X\n", p[i]);
+            break;
+          default:
+            fprintf(stderr, "%02X ", p[i]);
+            break;
+        }
+    }
+    if ((i & 15) != 15) {
+        fprintf(stderr, "\n");
+    }
+}
+#define hexdump(p,n) hexdump0((const unsigned char *)p, n)
+
+static void
+div_inspect(DebugInfoValue *v)
+{
+    switch (v->type) {
+      case VAL_uint:
+        fprintf(stderr,"%d: type:%d size:%zx v:%lx\n",__LINE__,v->type,v->size,v->as.uint64);
+        break;
+      case VAL_int:
+        fprintf(stderr,"%d: type:%d size:%zx v:%ld\n",__LINE__,v->type,v->size,(int64_t)v->as.uint64);
+        break;
+      case VAL_cstr:
+        fprintf(stderr,"%d: type:%d size:%zx v:'%s'\n",__LINE__,v->type,v->size,v->as.ptr);
+        break;
+      case VAL_data:
+        fprintf(stderr,"%d: type:%d size:%zx v:\n",__LINE__,v->type,v->size);
+        hexdump(v->as.ptr, 16);
+        break;
+    }
+}
+#endif
+
+static DIE *
+di_read_die(DebugInfoReader *reader, DIE *die)
+{
+    uint64_t abbrev_number = uleb128(&reader->p);
+    if (abbrev_number == 0) {
+        reader->level--;
+        return NULL;
+    }
+
+    reader->q = di_find_abbrev(reader, abbrev_number);
+
+    die->pos = reader->p - reader->obj->debug_info.ptr - 1;
+    die->tag = (int)uleb128(&reader->q); /* tag */
+    die->has_children = *reader->q++; /* has_children */
+    if (die->has_children) {
+        reader->level++;
+    }
+    return die;
+}
+
+static DebugInfoValue *
+di_read_record(DebugInfoReader *reader, DebugInfoValue *vp)
+{
+    uint64_t at = uleb128(&reader->q);
+    uint64_t form = uleb128(&reader->q);
+    if (!at || !form) return NULL;
+    vp->at = at;
+    vp->form = form;
+    debug_info_reader_read_value(reader, form, vp);
+    return vp;
+}
+
+static void
+di_skip_records(DebugInfoReader *reader)
+{
+    for (;;) {
+        DebugInfoValue v = {{}};
+        uint64_t at = uleb128(&reader->q);
+        uint64_t form = uleb128(&reader->q);
+        if (!at || !form) return;
+        debug_info_reader_read_value(reader, form, &v);
+    }
+}
+
+typedef struct {
+    uint64_t low_pc;
+    uint64_t high_pc;
+    uint64_t ranges;
+    bool low_pc_set;
+    bool high_pc_set;
+    bool ranges_set;
+} ranges_t;
+
+static void
+ranges_set(ranges_t *ptr, DebugInfoValue *v)
+{
+    switch (v->at) {
+      case DW_AT_low_pc:
+        ptr->low_pc = v->as.uint64;
+        ptr->low_pc_set = true;
+        break;
+      case DW_AT_high_pc:
+        if (v->form == DW_FORM_addr) {
+            ptr->high_pc = v->as.uint64;
+        }
+        else {
+            ptr->high_pc = ptr->low_pc + v->as.uint64;
+        }
+        ptr->high_pc_set = true;
+        break;
+      case DW_AT_ranges:
+        ptr->ranges = v->as.uint64;
+        ptr->ranges_set = true;
+        break;
+    }
+}
+
+static uintptr_t
+ranges_include(DebugInfoReader *reader, ranges_t *ptr, uint64_t addr)
+{
+    if (ptr->high_pc_set) {
+        if (ptr->ranges_set || !ptr->low_pc_set) {
+            exit(1);
+        }
+        if (ptr->low_pc <= addr && addr <= ptr->high_pc) {
+            return (uintptr_t)ptr->low_pc;
+        }
+    }
+    else if (ptr->ranges_set) {
+        /* TODO: support base address selection entry */
+        char *p = reader->obj->debug_ranges.ptr + ptr->ranges;
+        uint64_t base = ptr->low_pc_set ? ptr->low_pc : reader->current_low_pc;
+        for (;;) {
+            uintptr_t from = read_uintptr(&p);
+            uintptr_t to = read_uintptr(&p);
+            if (!from && !to) break;
+            if (from == UINTPTR_MAX) {
+                /* base address selection entry */
+                base = to;
+            }
+            else if (base + from <= addr && addr < base + to) {
+                return from;
+            }
+        }
+    }
+    else if (ptr->low_pc_set) {
+        if (ptr->low_pc == addr) {
+            return (uintptr_t)ptr->low_pc;
+        }
+    }
+    return false;
+}
+
+#if 0
+static void
+ranges_inspect(DebugInfoReader *reader, ranges_t *ptr)
+{
+    if (ptr->high_pc_set) {
+        if (ptr->ranges_set || !ptr->low_pc_set) {
+            fprintf(stderr,"low_pc_set:%d high_pc_set:%d ranges_set:%d\n",ptr->low_pc_set,ptr->high_pc_set,ptr->ranges_set);
+            exit(1);
+        }
+        fprintf(stderr,"low_pc:%"PRIx64" high_pc:%"PRIx64"\n",ptr->low_pc,ptr->high_pc);
+    }
+    else if (ptr->ranges_set) {
+        char *p = reader->obj->debug_ranges.ptr + ptr->ranges;
+        fprintf(stderr,"low_pc:%"PRIx64" ranges:%"PRIx64" %lx ",ptr->low_pc,ptr->ranges, p-reader->obj->mapped);
+        for (;;) {
+            uintptr_t from = read_uintptr(&p);
+            uintptr_t to = read_uintptr(&p);
+            if (!from && !to) break;
+            fprintf(stderr,"%"PRIx64"-%"PRIx64" ",ptr->low_pc+from,ptr->low_pc+to);
+        }
+        fprintf(stderr,"\n");
+    }
+    else if (ptr->low_pc_set) {
+        fprintf(stderr,"low_pc:%"PRIx64"\n",ptr->low_pc);
+    }
+    else {
+        fprintf(stderr,"empty\n");
+    }
+}
+#endif
+
+static int
+di_read_cu(DebugInfoReader *reader)
+{
+    uint64_t unit_length;
+    uint16_t version;
+    uint64_t debug_abbrev_offset;
+    reader->format = 4;
+    reader->current_cu = reader->p;
+    unit_length = read_uint32(&reader->p);
+    if (unit_length == 0xffffffff) {
+        unit_length = read_uint64(&reader->p);
+        reader->format = 8;
+    }
+    reader->cu_end = reader->p + unit_length;
+    version = read_uint16(&reader->p);
+    if (version > 5) {
+        return -1;
+    }
+    else if (version == 5) {
+        /* unit_type = */ read_uint8(&reader->p);
+        reader->address_size = read_uint8(&reader->p);
+        debug_abbrev_offset = read_uint(reader);
+    }
+    else {
+        debug_abbrev_offset = read_uint(reader);
+        reader->address_size = read_uint8(&reader->p);
+    }
+    reader->q0 = reader->obj->debug_abbrev.ptr + debug_abbrev_offset;
+
+    reader->level = 0;
+    di_read_debug_abbrev_cu(reader);
+    if (di_read_debug_line_cu(reader)) return -1;
+
+#if defined(__GNUC__) && !defined(__clang__) && !defined(__INTEL_COMPILER_BUILD_DATE)
+    /* Though DWARF specifies "the applicable base address defaults to the base
+       address of the compilation unit", but GCC seems to use zero as default */
+#else
+    do {
+        DIE die;
+
+        if (!di_read_die(reader, &die)) continue;
+
+        if (die.tag != DW_TAG_compile_unit) {
+            di_skip_records(reader);
+            break;
+        }
+
+        /* enumerate abbrev */
+        for (;;) {
+            DebugInfoValue v = {{}};
+            if (!di_read_record(reader, &v)) break;
+            switch (v.at) {
+              case DW_AT_low_pc:
+                reader->current_low_pc = v.as.uint64;
+                break;
+            }
+        }
+    } while (0);
+#endif
+    return 0;
+}
+
+static void
+read_abstract_origin(DebugInfoReader *reader, uint64_t abstract_origin, line_info_t *line)
+{
+    char *p = reader->p;
+    char *q = reader->q;
+    int level = reader->level;
+    DIE die;
+
+    reader->p = reader->current_cu + abstract_origin;
+    if (!di_read_die(reader, &die)) goto finish;
+
+    /* enumerate abbrev */
+    for (;;) {
+        DebugInfoValue v = {{}};
+        if (!di_read_record(reader, &v)) break;
+        switch (v.at) {
+          case DW_AT_name:
+            line->sname = get_cstr_value(&v);
+            break;
+        }
+    }
+
+  finish:
+    reader->p = p;
+    reader->q = q;
+    reader->level = level;
+}
+
+static void
+debug_info_read(DebugInfoReader *reader, int num_traces, void **traces,
+         line_info_t *lines, int offset) {
+    while (reader->p < reader->cu_end) {
+        DIE die;
+        ranges_t ranges = {};
+        line_info_t line = {};
+
+        if (!di_read_die(reader, &die)) continue;
+        /* fprintf(stderr,"%d:%tx: <%d>\n",__LINE__,die.pos,reader->level,die.tag); */
+
+        if (die.tag != DW_TAG_subprogram && die.tag != DW_TAG_inlined_subroutine) {
+          skip_die:
+            di_skip_records(reader);
+            continue;
+        }
+
+        /* enumerate abbrev */
+        for (;;) {
+            DebugInfoValue v = {{}};
+            /* ptrdiff_t pos = reader->p - reader->p0; */
+            if (!di_read_record(reader, &v)) break;
+            /* fprintf(stderr,"\n%d:%tx: AT:%lx FORM:%lx\n",__LINE__,pos,v.at,v.form); */
+            /* div_inspect(&v); */
+            switch (v.at) {
+              case DW_AT_name:
+                line.sname = get_cstr_value(&v);
+                break;
+              case DW_AT_call_file:
+                fill_filename((int)v.as.uint64, reader->debug_line_directories, reader->debug_line_files, &line, reader->obj);
+                break;
+              case DW_AT_call_line:
+                line.line = (int)v.as.uint64;
+                break;
+              case DW_AT_low_pc:
+              case DW_AT_high_pc:
+              case DW_AT_ranges:
+                ranges_set(&ranges, &v);
+                break;
+              case DW_AT_declaration:
+                goto skip_die;
+              case DW_AT_inline:
+                /* 1 or 3 */
+                break; /* goto skip_die; */
+              case DW_AT_abstract_origin:
+                read_abstract_origin(reader, v.as.uint64, &line);
+                break; /* goto skip_die; */
+            }
+        }
+        /* ranges_inspect(reader, &ranges); */
+        /* fprintf(stderr,"%d:%tx: %x ",__LINE__,diepos,die.tag); */
+        for (int i=offset; i < num_traces; i++) {
+            uintptr_t addr = (uintptr_t)traces[i];
+            uintptr_t offset = addr - reader->obj->base_addr + reader->obj->vmaddr;
+            uintptr_t saddr = ranges_include(reader, &ranges, offset);
+            if (saddr) {
+                /* fprintf(stderr, "%d:%tx: %d %lx->%lx %x %s: %s/%s %d %s %s %s\n",__LINE__,die.pos, i,addr,offset, die.tag,line.sname,line.dirname,line.filename,line.line,reader->obj->path,line.sname,lines[i].sname); */
+                if (lines[i].sname) {
+                    line_info_t *lp = malloc(sizeof(line_info_t));
+                    memcpy(lp, &lines[i], sizeof(line_info_t));
+                    lines[i].next = lp;
+                    lp->dirname = line.dirname;
+                    lp->filename = line.filename;
+                    lp->line = line.line;
+                    lp->saddr = 0;
+                }
+                lines[i].path = reader->obj->path;
+                lines[i].base_addr = line.base_addr;
+                lines[i].sname = line.sname;
+                lines[i].saddr = saddr + reader->obj->base_addr - reader->obj->vmaddr;
+            }
+        }
+    }
+}
+
+#ifdef USE_ELF
+static unsigned long
+uncompress_debug_section(ElfW(Shdr) *shdr, char *file, char **ptr)
+{
+    *ptr = NULL;
+#ifdef SUPPORT_COMPRESSED_DEBUG_LINE
+    ElfW(Chdr) *chdr = (ElfW(Chdr) *)(file + shdr->sh_offset);
+    unsigned long destsize = chdr->ch_size;
+    int ret = 0;
+
+    if (chdr->ch_type != ELFCOMPRESS_ZLIB) {
+	/* unsupported compression type */
+	return 0;
+    }
+
+    *ptr = malloc(destsize);
+    if (!*ptr) return 0;
+    ret = uncompress((Bytef *)*ptr, &destsize,
+	    (const Bytef*)chdr + sizeof(ElfW(Chdr)),
+            shdr->sh_size - sizeof(ElfW(Chdr)));
+    if (ret != Z_OK) goto fail;
+    return destsize;
+
+fail:
+    free(*ptr);
+    *ptr = NULL;
+#endif
+    return 0;
+}
+
+/* read file and fill lines */
+static uintptr_t
+fill_lines(int num_traces, void **traces, int check_debuglink,
+	   obj_info_t **objp, line_info_t *lines, int offset)
+{
+    int i, j;
+    char *shstr;
+    ElfW(Ehdr) *ehdr;
+    ElfW(Shdr) *shdr, *shstr_shdr;
+    ElfW(Shdr) *gnu_debuglink_shdr = NULL;
+    ElfW(Shdr) *note_gnu_build_id = NULL;
+    int fd;
+    off_t filesize;
+    char *file;
+    ElfW(Shdr) *symtab_shdr = NULL, *strtab_shdr = NULL;
+    ElfW(Shdr) *dynsym_shdr = NULL, *dynstr_shdr = NULL;
+    obj_info_t *obj = *objp;
+    uintptr_t dladdr_fbase = 0;
+
+    fd = open(binary_filename, O_RDONLY);
+    if (fd < 0) {
+	goto fail;
+    }
+    filesize = lseek(fd, 0, SEEK_END);
+    if (filesize < 0) {
+	int e = errno;
+	close(fd);
+	kprintf("lseek: %s\n", strerror(e));
+	goto fail;
+    }
+#if SIZEOF_OFF_T > SIZEOF_SIZE_T
+    if (filesize > (off_t)SIZE_MAX) {
+	close(fd);
+	kprintf("Too large file %s\n", binary_filename);
+	goto fail;
+    }
+#endif
+    lseek(fd, 0, SEEK_SET);
+    /* async-signal unsafe */
+    file = (char *)mmap(NULL, (size_t)filesize, PROT_READ, MAP_SHARED, fd, 0);
+    if (file == MAP_FAILED) {
+	int e = errno;
+	close(fd);
+	kprintf("mmap: %s\n", strerror(e));
+	goto fail;
+    }
+    close(fd);
+
+    ehdr = (ElfW(Ehdr) *)file;
+    if (memcmp(ehdr->e_ident, "\177ELF", 4) != 0) {
+	/*
+	 * Huh? Maybe filename was overridden by setproctitle() and
+	 * it match non-elf file.
+	 */
+	goto fail;
+    }
+    obj->mapped = file;
+    obj->mapped_size = (size_t)filesize;
+
+    shdr = (ElfW(Shdr) *)(file + ehdr->e_shoff);
+
+    shstr_shdr = shdr + ehdr->e_shstrndx;
+    shstr = file + shstr_shdr->sh_offset;
+
+    for (i = 0; i < ehdr->e_shnum; i++) {
+        char *section_name = shstr + shdr[i].sh_name;
+	switch (shdr[i].sh_type) {
+	  case SHT_STRTAB:
+	    if (!strcmp(section_name, ".strtab")) {
+		strtab_shdr = shdr + i;
+	    }
+	    else if (!strcmp(section_name, ".dynstr")) {
+		dynstr_shdr = shdr + i;
+	    }
+	    break;
+	  case SHT_SYMTAB:
+	    /* if (!strcmp(section_name, ".symtab")) */
+	    symtab_shdr = shdr + i;
+	    break;
+	  case SHT_DYNSYM:
+	    /* if (!strcmp(section_name, ".dynsym")) */
+	    dynsym_shdr = shdr + i;
+	    break;
+          case SHT_NOTE:
+            if (!strcmp(section_name, ".note.gnu.build-id")) {
+                note_gnu_build_id = shdr + i;
+            }
+            break;
+	  case SHT_PROGBITS:
+	    if (!strcmp(section_name, ".gnu_debuglink")) {
+		gnu_debuglink_shdr = shdr + i;
+	    }
+            else {
+                const char *debug_section_names[] = {
+                    ".debug_abbrev",
+                    ".debug_info",
+                    ".debug_line",
+                    ".debug_ranges",
+                    ".debug_str"
+                };
+
+                for (j=0; j < DWARF_SECTION_COUNT; j++) {
+                    struct dwarf_section *s = obj_dwarf_section_at(obj, j);
+
+                    if (strcmp(section_name, debug_section_names[j]) != 0)
+                        continue;
+
+                    s->ptr = file + shdr[i].sh_offset;
+                    s->size = shdr[i].sh_size;
+                    s->flags = shdr[i].sh_flags;
+                    if (s->flags & SHF_COMPRESSED) {
+                        s->size = uncompress_debug_section(&shdr[i], file, &s->ptr);
+                        if (!s->size) goto fail;
+                    }
+                    break;
+                }
+            }
+	    break;
+	}
+    }
+
+    if (offset == -1) {
+	/* main executable */
+	offset = 0;
+	if (dynsym_shdr && dynstr_shdr) {
+	    char *strtab = file + dynstr_shdr->sh_offset;
+	    ElfW(Sym) *symtab = (ElfW(Sym) *)(file + dynsym_shdr->sh_offset);
+	    int symtab_count = (int)(dynsym_shdr->sh_size / sizeof(ElfW(Sym)));
+            void *handle = dlopen(NULL, RTLD_NOW|RTLD_LOCAL);
+            if (handle) {
+                for (j = 0; j < symtab_count; j++) {
+                    ElfW(Sym) *sym = &symtab[j];
+                    Dl_info info;
+                    void *s;
+                    if (ELF_ST_TYPE(sym->st_info) != STT_FUNC || sym->st_size == 0) continue;
+                    s = dlsym(handle, strtab + sym->st_name);
+                    if (s && dladdr(s, &info)) {
+                        obj->base_addr = dladdr_fbase;
+                        dladdr_fbase = (uintptr_t)info.dli_fbase;
+                        break;
+                    }
+                }
+                dlclose(handle);
+            }
+	    if (ehdr->e_type == ET_EXEC) {
+		obj->base_addr = 0;
+	    }
+	    else {
+		/* PIE (position-independent executable) */
+		obj->base_addr = dladdr_fbase;
+	    }
+	}
+    }
+
+    if (obj->debug_info.ptr && obj->debug_abbrev.ptr) {
+        DebugInfoReader reader;
+        debug_info_reader_init(&reader, obj);
+        i = 0;
+        while (reader.p < reader.pend) {
+            /* fprintf(stderr, "%d:%tx: CU[%d]\n", __LINE__, reader.p - reader.obj->debug_info.ptr, i++); */
+            if (di_read_cu(&reader)) goto use_symtab;
+            debug_info_read(&reader, num_traces, traces, lines, offset);
+        }
+    }
+    else {
+        /* This file doesn't have dwarf, use symtab or dynsym */
+use_symtab:
+        if (!symtab_shdr) {
+            /* This file doesn't have symtab, use dynsym instead */
+            symtab_shdr = dynsym_shdr;
+            strtab_shdr = dynstr_shdr;
+        }
+
+        if (symtab_shdr && strtab_shdr) {
+            char *strtab = file + strtab_shdr->sh_offset;
+            ElfW(Sym) *symtab = (ElfW(Sym) *)(file + symtab_shdr->sh_offset);
+            int symtab_count = (int)(symtab_shdr->sh_size / sizeof(ElfW(Sym)));
+            for (j = 0; j < symtab_count; j++) {
+                ElfW(Sym) *sym = &symtab[j];
+                uintptr_t saddr = (uintptr_t)sym->st_value + obj->base_addr;
+                if (ELF_ST_TYPE(sym->st_info) != STT_FUNC) continue;
+                for (i = offset; i < num_traces; i++) {
+                    uintptr_t d = (uintptr_t)traces[i] - saddr;
+                    if (lines[i].line > 0 || d > (uintptr_t)sym->st_size)
+                        continue;
+                    /* fill symbol name and addr from .symtab */
+                    if (!lines[i].sname) lines[i].sname = strtab + sym->st_name;
+                    lines[i].saddr = saddr;
+                    lines[i].path  = obj->path;
+                    lines[i].base_addr = obj->base_addr;
+                }
+            }
+        }
+    }
+
+    if (!obj->debug_line.ptr) {
+	/* This file doesn't have .debug_line section,
+	   let's check .gnu_debuglink section instead. */
+	if (gnu_debuglink_shdr && check_debuglink) {
+	    follow_debuglink(file + gnu_debuglink_shdr->sh_offset,
+			     num_traces, traces,
+			     objp, lines, offset);
+	}
+        if (note_gnu_build_id && check_debuglink) {
+            ElfW(Nhdr) *nhdr = (ElfW(Nhdr)*) (file + note_gnu_build_id->sh_offset);
+            const char *build_id = (char *)(nhdr + 1) + nhdr->n_namesz;
+            follow_debuglink_build_id(build_id, nhdr->n_descsz,
+			       num_traces, traces,
+			       objp, lines, offset);
+        }
+	goto finish;
+    }
+
+    if (parse_debug_line(num_traces, traces,
+            obj->debug_line.ptr,
+            obj->debug_line.size,
+            obj, lines, offset) == -1)
+        goto fail;
+
+finish:
+    return dladdr_fbase;
+fail:
+    return (uintptr_t)-1;
+}
+#else /* Mach-O */
+/* read file and fill lines */
+static uintptr_t
+fill_lines(int num_traces, void **traces, int check_debuglink,
+        obj_info_t **objp, line_info_t *lines, int offset)
+{
+# ifdef __LP64__
+#  define LP(x) x##_64
+# else
+#  define LP(x) x
+# endif
+    int fd;
+    off_t filesize;
+    char *file, *p = NULL;
+    obj_info_t *obj = *objp;
+    struct LP(mach_header) *header;
+    uintptr_t dladdr_fbase = 0;
+
+    {
+        char *s = binary_filename;
+        char *base = strrchr(binary_filename, '/')+1;
+        size_t max = PATH_MAX;
+        size_t size = strlen(binary_filename);
+        size_t basesize = size - (base - binary_filename);
+        s += size;
+        max -= size;
+        p = s;
+        size = strlcpy(s, ".dSYM/Contents/Resources/DWARF/", max);
+        if (size == 0) goto fail;
+        s += size;
+        max -= size;
+        if (max <= basesize) goto fail;
+        memcpy(s, base, basesize);
+        s[basesize] = 0;
+
+        fd = open(binary_filename, O_RDONLY);
+        if (fd < 0) {
+            *p = 0; /* binary_filename becomes original file name */
+            fd = open(binary_filename, O_RDONLY);
+            if (fd < 0) {
+                goto fail;
+            }
+        }
+    }
+
+    filesize = lseek(fd, 0, SEEK_END);
+    if (filesize < 0) {
+        int e = errno;
+        close(fd);
+        kprintf("lseek: %s\n", strerror(e));
+        goto fail;
+    }
+#if SIZEOF_OFF_T > SIZEOF_SIZE_T
+    if (filesize > (off_t)SIZE_MAX) {
+        close(fd);
+        kprintf("Too large file %s\n", binary_filename);
+        goto fail;
+    }
+#endif
+    lseek(fd, 0, SEEK_SET);
+    /* async-signal unsafe */
+    file = (char *)mmap(NULL, (size_t)filesize, PROT_READ, MAP_SHARED, fd, 0);
+    if (file == MAP_FAILED) {
+        int e = errno;
+        close(fd);
+        kprintf("mmap: %s\n", strerror(e));
+        goto fail;
+    }
+    close(fd);
+
+    obj->mapped = file;
+    obj->mapped_size = (size_t)filesize;
+
+    header = (struct LP(mach_header) *)file;
+    if (header->magic == LP(MH_MAGIC)) {
+        /* non universal binary */
+        p = file;
+    }
+    else if (header->magic == FAT_CIGAM) {
+        struct LP(mach_header) *mhp = _NSGetMachExecuteHeader();
+        struct fat_header *fat = (struct fat_header *)file;
+        char *q = file + sizeof(*fat);
+        uint32_t nfat_arch = __builtin_bswap32(fat->nfat_arch);
+        /* fprintf(stderr,"%d: fat:%s %d\n",__LINE__, binary_filename,nfat_arch); */
+        for (uint32_t i = 0; i < nfat_arch; i++) {
+            struct fat_arch *arch = (struct fat_arch *)q;
+            cpu_type_t cputype = __builtin_bswap32(arch->cputype);
+            cpu_subtype_t cpusubtype = __builtin_bswap32(arch->cpusubtype);
+            uint32_t offset = __builtin_bswap32(arch->offset);
+            /* fprintf(stderr,"%d: fat %d %x/%x %x/%x\n",__LINE__, i, mhp->cputype,mhp->cpusubtype, cputype,cpusubtype); */
+            if (mhp->cputype == cputype &&
+                    (cpu_subtype_t)(mhp->cpusubtype & ~CPU_SUBTYPE_MASK) == cpusubtype) {
+                p = file + offset;
+                file = p;
+                header = (struct LP(mach_header) *)p;
+                if (header->magic == LP(MH_MAGIC)) {
+                    goto found_mach_header;
+                }
+                break;
+            }
+            q += sizeof(*arch);
+        }
+        kprintf("'%s' is not a Mach-O universal binary file!\n",binary_filename);
+        close(fd);
+        goto fail;
+    }
+    else {
+        kprintf("'%s' is not a "
+# ifdef __LP64__
+                "64"
+# else
+                "32"
+# endif
+                "-bit Mach-O file!\n",binary_filename);
+        close(fd);
+        goto fail;
+    }
+found_mach_header:
+    p += sizeof(*header);
+
+    for (uint32_t i = 0; i < (uint32_t)header->ncmds; i++) {
+        struct load_command *lcmd = (struct load_command *)p;
+        switch (lcmd->cmd) {
+          case LP(LC_SEGMENT):
+            {
+                static const char *debug_section_names[] = {
+                    "__debug_abbrev",
+                    "__debug_info",
+                    "__debug_line",
+                    "__debug_ranges",
+                    "__debug_str"
+                };
+                struct LP(segment_command) *scmd = (struct LP(segment_command) *)lcmd;
+                if (strcmp(scmd->segname, "__TEXT") == 0) {
+                    obj->vmaddr = scmd->vmaddr;
+                }
+                else if (strcmp(scmd->segname, "__DWARF") == 0) {
+                    p += sizeof(struct LP(segment_command));
+                    for (uint64_t i = 0; i < scmd->nsects; i++) {
+                        struct LP(section) *sect = (struct LP(section) *)p;
+                        p += sizeof(struct LP(section));
+                        for (int j=0; j < DWARF_SECTION_COUNT; j++) {
+                            struct dwarf_section *s = obj_dwarf_section_at(obj, j);
+
+                            if (strcmp(sect->sectname, debug_section_names[j]) != 0)
+                                continue;
+
+                            s->ptr = file + sect->offset;
+                            s->size = sect->size;
+                            s->flags = sect->flags;
+                            if (s->flags & SHF_COMPRESSED) {
+                                goto fail;
+                            }
+                            break;
+                        }
+                    }
+                }
+            }
+            break;
+
+          case LC_SYMTAB:
+            {
+                struct symtab_command *cmd = (struct symtab_command *)lcmd;
+                struct LP(nlist) *nl = (struct LP(nlist) *)(file + cmd->symoff);
+                char *strtab = file + cmd->stroff, *sname = 0;
+                uint32_t j;
+                uintptr_t saddr = 0;
+                /* kprintf("[%2d]: %x/symtab %p\n", i, cmd->cmd, p); */
+                for (j = 0; j < cmd->nsyms; j++) {
+                    uintptr_t symsize, d;
+                    struct LP(nlist) *e = &nl[j];
+                        /* kprintf("[%2d][%4d]: %02x/%x/%x: %s %llx\n", i, j, e->n_type,e->n_sect,e->n_desc,strtab+e->n_un.n_strx,e->n_value); */
+                    if (e->n_type != N_FUN) continue;
+                    if (e->n_sect) {
+                        saddr = (uintptr_t)e->n_value + obj->base_addr - obj->vmaddr;
+                        sname = strtab + e->n_un.n_strx;
+                        /* kprintf("[%2d][%4d]: %02x/%x/%x: %s %llx\n", i, j, e->n_type,e->n_sect,e->n_desc,strtab+e->n_un.n_strx,e->n_value); */
+                        continue;
+                    }
+                    for (int k = offset; k < num_traces; k++) {
+                        d = (uintptr_t)traces[k] - saddr;
+                        symsize = e->n_value;
+                        /* kprintf("%lx %lx %lx\n",saddr,symsize,traces[k]); */
+                        if (lines[k].line > 0 || d > (uintptr_t)symsize)
+                            continue;
+                        /* fill symbol name and addr from .symtab */
+                        if (!lines[k].sname) lines[k].sname = sname;
+                        lines[k].saddr = saddr;
+                        lines[k].path  = obj->path;
+                        lines[k].base_addr = obj->base_addr;
+                    }
+                }
+            }
+        }
+        p += lcmd->cmdsize;
+    }
+
+    if (obj->debug_info.ptr && obj->debug_abbrev.ptr) {
+        DebugInfoReader reader;
+        debug_info_reader_init(&reader, obj);
+        while (reader.p < reader.pend) {
+            if (di_read_cu(&reader)) goto fail;
+            debug_info_read(&reader, num_traces, traces, lines, offset);
+        }
+    }
+
+    if (parse_debug_line(num_traces, traces,
+            obj->debug_line.ptr,
+            obj->debug_line.size,
+            obj, lines, offset) == -1)
+        goto fail;
+
+    return dladdr_fbase;
+fail:
+    return (uintptr_t)-1;
+}
+#endif
+
+#define HAVE_MAIN_EXE_PATH
+#if defined(__FreeBSD__)
+# include <sys/sysctl.h>
+#endif
+/* ssize_t main_exe_path(void)
+ *
+ * store the path of the main executable to `binary_filename`,
+ * and returns strlen(binary_filename).
+ * it is NUL terminated.
+ */
+#if defined(__linux__) || defined(__NetBSD__)
+static ssize_t
+main_exe_path(void)
+{
+# if defined(__linux__)
+#  define PROC_SELF_EXE "/proc/self/exe"
+# elif defined(__NetBSD__)
+#  define PROC_SELF_EXE "/proc/curproc/exe"
+# endif
+    ssize_t len = readlink(PROC_SELF_EXE, binary_filename, PATH_MAX);
+    if (len < 0) return 0;
+    binary_filename[len] = 0;
+    return len;
+}
+#elif defined(__FreeBSD__)
+static ssize_t
+main_exe_path(void)
+{
+    int mib[4] = {CTL_KERN, KERN_PROC, KERN_PROC_PATHNAME, -1};
+    size_t len = PATH_MAX;
+    int err = sysctl(mib, 4, binary_filename, &len, NULL, 0);
+    if (err) {
+	kprintf("Can't get the path of ruby");
+	return -1;
+    }
+    len--; /* sysctl sets strlen+1 */
+    return len;
+}
+#elif defined(HAVE_LIBPROC_H)
+static ssize_t
+main_exe_path(void)
+{
+    int len = proc_pidpath(getpid(), binary_filename, PATH_MAX);
+    if (len == 0) return 0;
+    binary_filename[len] = 0;
+    return len;
+}
+#else
+#undef HAVE_MAIN_EXE_PATH
+#endif
+
+static void
+print_line0(line_info_t *line, void *address)
+{
+    uintptr_t addr = (uintptr_t)address;
+    uintptr_t d = addr - line->saddr;
+    if (!address) {
+        /* inlined */
+        if (line->dirname && line->dirname[0]) {
+            kprintf("%s(%s) %s/%s:%d\n", line->path, line->sname, line->dirname, line->filename, line->line);
+        }
+        else {
+            kprintf("%s(%s) %s:%d\n", line->path, line->sname, line->filename, line->line);
+        }
+    }
+    else if (!line->path) {
+        kprintf("[0x%"PRIxPTR"]\n", addr);
+    }
+    else if (!line->saddr || !line->sname) {
+        kprintf("%s(0x%"PRIxPTR") [0x%"PRIxPTR"]\n", line->path, addr-line->base_addr, addr);
+    }
+    else if (line->line <= 0) {
+        kprintf("%s(%s+0x%"PRIxPTR") [0x%"PRIxPTR"]\n", line->path, line->sname,
+                d, addr);
+    }
+    else if (!line->filename) {
+        kprintf("%s(%s+0x%"PRIxPTR") [0x%"PRIxPTR"] ???:%d\n", line->path, line->sname,
+                d, addr, line->line);
+    }
+    else if (line->dirname && line->dirname[0]) {
+        kprintf("%s(%s+0x%"PRIxPTR") [0x%"PRIxPTR"] %s/%s:%d\n", line->path, line->sname,
+                d, addr, line->dirname, line->filename, line->line);
+    }
+    else {
+        kprintf("%s(%s+0x%"PRIxPTR") [0x%"PRIxPTR"] %s:%d\n", line->path, line->sname,
+                d, addr, line->filename, line->line);
+    }
+}
+
+static void
+print_line(line_info_t *line, void *address)
+{
+    print_line0(line, address);
+    if (line->next) {
+        print_line(line->next, NULL);
+    }
+}
+
+void
+rb_dump_backtrace_with_lines(int num_traces, void **traces)
+{
+    int i;
+    /* async-signal unsafe */
+    line_info_t *lines = (line_info_t *)calloc(num_traces, sizeof(line_info_t));
+    obj_info_t *obj = NULL;
+    /* 2 is NULL + main executable */
+    void **dladdr_fbases = (void **)calloc(num_traces+2, sizeof(void *));
+#ifdef HAVE_MAIN_EXE_PATH
+    char *main_path = NULL; /* used on printing backtrace */
+    ssize_t len;
+    if ((len = main_exe_path()) > 0) {
+	main_path = (char *)alloca(len + 1);
+	if (main_path) {
+	    uintptr_t addr;
+	    memcpy(main_path, binary_filename, len+1);
+	    append_obj(&obj);
+	    obj->path = main_path;
+	    addr = fill_lines(num_traces, traces, 1, &obj, lines, -1);
+	    if (addr != (uintptr_t)-1) {
+		dladdr_fbases[0] = (void *)addr;
+	    }
+	}
+    }
+#endif
+
+    /* fill source lines by reading dwarf */
+    for (i = 0; i < num_traces; i++) {
+	Dl_info info;
+	if (lines[i].line) continue;
+	if (dladdr(traces[i], &info)) {
+	    const char *path;
+	    void **p;
+
+	    /* skip symbols which is in already checked objects */
+	    /* if the binary is strip-ed, this may effect */
+	    for (p=dladdr_fbases; *p; p++) {
+		if (*p == info.dli_fbase) {
+		    lines[i].path = info.dli_fname;
+		    lines[i].sname = info.dli_sname;
+		    goto next_line;
+		}
+	    }
+	    *p = info.dli_fbase;
+
+	    append_obj(&obj);
+	    obj->base_addr = (uintptr_t)info.dli_fbase;
+	    path = info.dli_fname;
+	    obj->path = path;
+	    lines[i].path = path;
+            lines[i].sname = info.dli_sname;
+            lines[i].saddr = (uintptr_t)info.dli_saddr;
+	    strlcpy(binary_filename, path, PATH_MAX);
+	    if (fill_lines(num_traces, traces, 1, &obj, lines, i) == (uintptr_t)-1)
+		break;
+	}
+next_line:
+	continue;
+    }
+
+    /* output */
+    for (i = 0; i < num_traces; i++) {
+        print_line(&lines[i], traces[i]);
+
+	/* FreeBSD's backtrace may show _start and so on */
+	if (lines[i].sname && strcmp("main", lines[i].sname) == 0)
+	    break;
+    }
+
+    /* free */
+    while (obj) {
+	obj_info_t *o = obj;
+        for (i=0; i < DWARF_SECTION_COUNT; i++) {
+            struct dwarf_section *s = obj_dwarf_section_at(obj, i);
+            if (s->flags & SHF_COMPRESSED) {
+                free(s->ptr);
+            }
+        }
+	if (obj->mapped_size) {
+	    munmap(obj->mapped, obj->mapped_size);
+	}
+	obj = o->next;
+	free(o);
+    }
+    for (i = 0; i < num_traces; i++) {
+        line_info_t *line = lines[i].next;
+        while (line) {
+            line_info_t *l = line;
+            line = line->next;
+            free(l);
+        }
+    }
+    free(lines);
+    free(dladdr_fbases);
+}
+
+/* From FreeBSD's lib/libstand/printf.c */
+/*-
+ * Copyright (c) 1986, 1988, 1991, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ * (c) UNIX System Laboratories, Inc.
+ * All or some portions of this file are derived from material licensed
+ * to the University of California by American Telephone and Telegraph
+ * Co. or Unix System Laboratories, Inc. and are reproduced herein with
+ * the permission of UNIX System Laboratories, Inc.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *	@(#)subr_prf.c	8.3 (Berkeley) 1/21/94
+ */
+
+#include <stdarg.h>
+#define MAXNBUF (sizeof(intmax_t) * CHAR_BIT + 1)
+static inline int toupper(int c) { return ('A' <= c && c <= 'Z') ? (c&0x5f) : c; }
+#define    hex2ascii(hex)  (hex2ascii_data[hex])
+static const char hex2ascii_data[] = "0123456789abcdefghijklmnopqrstuvwxyz";
+static inline int imax(int a, int b) { return (a > b ? a : b); }
+static int kvprintf(char const *fmt, void (*func)(int), void *arg, int radix, va_list ap);
+
+static void putce(int c)
+{
+    char s[1];
+    ssize_t ret;
+
+    s[0] = (char)c;
+    ret = write(2, s, 1);
+    (void)ret;
+}
+
+static int
+kprintf(const char *fmt, ...)
+{
+	va_list ap;
+	int retval;
+
+	va_start(ap, fmt);
+	retval = kvprintf(fmt, putce, NULL, 10, ap);
+	va_end(ap);
+	return retval;
+}
+
+/*
+ * Put a NUL-terminated ASCII number (base <= 36) in a buffer in reverse
+ * order; return an optional length and a pointer to the last character
+ * written in the buffer (i.e., the first character of the string).
+ * The buffer pointed to by `nbuf' must have length >= MAXNBUF.
+ */
+static char *
+ksprintn(char *nbuf, uintmax_t num, int base, int *lenp, int upper)
+{
+	char *p, c;
+
+	p = nbuf;
+	*p = '\0';
+	do {
+		c = hex2ascii(num % base);
+		*++p = upper ? toupper(c) : c;
+	} while (num /= base);
+	if (lenp)
+		*lenp = (int)(p - nbuf);
+	return (p);
+}
+
+/*
+ * Scaled down version of printf(3).
+ *
+ * Two additional formats:
+ *
+ * The format %b is supported to decode error registers.
+ * Its usage is:
+ *
+ *	printf("reg=%b\n", regval, "<base><arg>*");
+ *
+ * where <base> is the output base expressed as a control character, e.g.
+ * \10 gives octal; \20 gives hex.  Each arg is a sequence of characters,
+ * the first of which gives the bit number to be inspected (origin 1), and
+ * the next characters (up to a control character, i.e. a character <= 32),
+ * give the name of the register.  Thus:
+ *
+ *	kvprintf("reg=%b\n", 3, "\10\2BITTWO\1BITONE\n");
+ *
+ * would produce output:
+ *
+ *	reg=3<BITTWO,BITONE>
+ *
+ * XXX:  %D  -- Hexdump, takes pointer and separator string:
+ *		("%6D", ptr, ":")   -> XX:XX:XX:XX:XX:XX
+ *		("%*D", len, ptr, " " -> XX XX XX XX ...
+ */
+static int
+kvprintf(char const *fmt, void (*func)(int), void *arg, int radix, va_list ap)
+{
+#define PCHAR(c) {int cc=(c); if (func) (*func)(cc); else *d++ = cc; retval++; }
+	char nbuf[MAXNBUF];
+	char *d;
+	const char *p, *percent, *q;
+	unsigned char *up;
+	int ch, n;
+	uintmax_t num;
+	int base, lflag, qflag, tmp, width, ladjust, sharpflag, neg, sign, dot;
+	int cflag, hflag, jflag, tflag, zflag;
+	int dwidth, upper;
+	char padc;
+	int stop = 0, retval = 0;
+
+	num = 0;
+	if (!func)
+		d = (char *) arg;
+	else
+		d = NULL;
+
+	if (fmt == NULL)
+		fmt = "(fmt null)\n";
+
+	if (radix < 2 || radix > 36)
+		radix = 10;
+
+	for (;;) {
+		padc = ' ';
+		width = 0;
+		while ((ch = (unsigned char)*fmt++) != '%' || stop) {
+			if (ch == '\0')
+				return (retval);
+			PCHAR(ch);
+		}
+		percent = fmt - 1;
+		qflag = 0; lflag = 0; ladjust = 0; sharpflag = 0; neg = 0;
+		sign = 0; dot = 0; dwidth = 0; upper = 0;
+		cflag = 0; hflag = 0; jflag = 0; tflag = 0; zflag = 0;
+reswitch:	switch (ch = (unsigned char)*fmt++) {
+		case '.':
+			dot = 1;
+			goto reswitch;
+		case '#':
+			sharpflag = 1;
+			goto reswitch;
+		case '+':
+			sign = 1;
+			goto reswitch;
+		case '-':
+			ladjust = 1;
+			goto reswitch;
+		case '%':
+			PCHAR(ch);
+			break;
+		case '*':
+			if (!dot) {
+				width = va_arg(ap, int);
+				if (width < 0) {
+					ladjust = !ladjust;
+					width = -width;
+				}
+			} else {
+				dwidth = va_arg(ap, int);
+			}
+			goto reswitch;
+		case '0':
+			if (!dot) {
+				padc = '0';
+				goto reswitch;
+			}
+		case '1': case '2': case '3': case '4':
+		case '5': case '6': case '7': case '8': case '9':
+				for (n = 0;; ++fmt) {
+					n = n * 10 + ch - '0';
+					ch = *fmt;
+					if (ch < '0' || ch > '9')
+						break;
+				}
+			if (dot)
+				dwidth = n;
+			else
+				width = n;
+			goto reswitch;
+		case 'b':
+			num = (unsigned int)va_arg(ap, int);
+			p = va_arg(ap, char *);
+			for (q = ksprintn(nbuf, num, *p++, NULL, 0); *q;)
+				PCHAR(*q--);
+
+			if (num == 0)
+				break;
+
+			for (tmp = 0; *p;) {
+				n = *p++;
+				if (num & (1 << (n - 1))) {
+					PCHAR(tmp ? ',' : '<');
+					for (; (n = *p) > ' '; ++p)
+						PCHAR(n);
+					tmp = 1;
+				} else
+					for (; *p > ' '; ++p)
+						continue;
+			}
+			if (tmp)
+				PCHAR('>');
+			break;
+		case 'c':
+			PCHAR(va_arg(ap, int));
+			break;
+		case 'D':
+			up = va_arg(ap, unsigned char *);
+			p = va_arg(ap, char *);
+			if (!width)
+				width = 16;
+			while(width--) {
+				PCHAR(hex2ascii(*up >> 4));
+				PCHAR(hex2ascii(*up & 0x0f));
+				up++;
+				if (width)
+					for (q=p;*q;q++)
+						PCHAR(*q);
+			}
+			break;
+		case 'd':
+		case 'i':
+			base = 10;
+			sign = 1;
+			goto handle_sign;
+		case 'h':
+			if (hflag) {
+				hflag = 0;
+				cflag = 1;
+			} else
+				hflag = 1;
+			goto reswitch;
+		case 'j':
+			jflag = 1;
+			goto reswitch;
+		case 'l':
+			if (lflag) {
+				lflag = 0;
+				qflag = 1;
+			} else
+				lflag = 1;
+			goto reswitch;
+		case 'n':
+			if (jflag)
+				*(va_arg(ap, intmax_t *)) = retval;
+			else if (qflag)
+				*(va_arg(ap, int64_t *)) = retval;
+			else if (lflag)
+				*(va_arg(ap, long *)) = retval;
+			else if (zflag)
+				*(va_arg(ap, size_t *)) = retval;
+			else if (hflag)
+				*(va_arg(ap, short *)) = retval;
+			else if (cflag)
+				*(va_arg(ap, char *)) = retval;
+			else
+				*(va_arg(ap, int *)) = retval;
+			break;
+		case 'o':
+			base = 8;
+			goto handle_nosign;
+		case 'p':
+			base = 16;
+			sharpflag = (width == 0);
+			sign = 0;
+			num = (uintptr_t)va_arg(ap, void *);
+			goto number;
+		case 'q':
+			qflag = 1;
+			goto reswitch;
+		case 'r':
+			base = radix;
+			if (sign)
+				goto handle_sign;
+			goto handle_nosign;
+		case 's':
+			p = va_arg(ap, char *);
+			if (p == NULL)
+				p = "(null)";
+			if (!dot)
+				n = (int)strlen (p);
+			else
+				for (n = 0; n < dwidth && p[n]; n++)
+					continue;
+
+			width -= n;
+
+			if (!ladjust && width > 0)
+				while (width--)
+					PCHAR(padc);
+			while (n--)
+				PCHAR(*p++);
+			if (ladjust && width > 0)
+				while (width--)
+					PCHAR(padc);
+			break;
+		case 't':
+			tflag = 1;
+			goto reswitch;
+		case 'u':
+			base = 10;
+			goto handle_nosign;
+		case 'X':
+			upper = 1;
+		case 'x':
+			base = 16;
+			goto handle_nosign;
+		case 'y':
+			base = 16;
+			sign = 1;
+			goto handle_sign;
+		case 'z':
+			zflag = 1;
+			goto reswitch;
+handle_nosign:
+			sign = 0;
+			if (jflag)
+				num = va_arg(ap, uintmax_t);
+			else if (qflag)
+				num = va_arg(ap, uint64_t);
+			else if (tflag)
+				num = va_arg(ap, ptrdiff_t);
+			else if (lflag)
+				num = va_arg(ap, unsigned long);
+			else if (zflag)
+				num = va_arg(ap, size_t);
+			else if (hflag)
+				num = (unsigned short)va_arg(ap, int);
+			else if (cflag)
+				num = (unsigned char)va_arg(ap, int);
+			else
+				num = va_arg(ap, unsigned int);
+			goto number;
+handle_sign:
+			if (jflag)
+				num = va_arg(ap, intmax_t);
+			else if (qflag)
+				num = va_arg(ap, int64_t);
+			else if (tflag)
+				num = va_arg(ap, ptrdiff_t);
+			else if (lflag)
+				num = va_arg(ap, long);
+			else if (zflag)
+				num = va_arg(ap, ssize_t);
+			else if (hflag)
+				num = (short)va_arg(ap, int);
+			else if (cflag)
+				num = (char)va_arg(ap, int);
+			else
+				num = va_arg(ap, int);
+number:
+			if (sign && (intmax_t)num < 0) {
+				neg = 1;
+				num = -(intmax_t)num;
+			}
+			p = ksprintn(nbuf, num, base, &n, upper);
+			tmp = 0;
+			if (sharpflag && num != 0) {
+				if (base == 8)
+					tmp++;
+				else if (base == 16)
+					tmp += 2;
+			}
+			if (neg)
+				tmp++;
+
+			if (!ladjust && padc == '0')
+				dwidth = width - tmp;
+			width -= tmp + imax(dwidth, n);
+			dwidth -= n;
+			if (!ladjust)
+				while (width-- > 0)
+					PCHAR(' ');
+			if (neg)
+				PCHAR('-');
+			if (sharpflag && num != 0) {
+				if (base == 8) {
+					PCHAR('0');
+				} else if (base == 16) {
+					PCHAR('0');
+					PCHAR('x');
+				}
+			}
+			while (dwidth-- > 0)
+				PCHAR('0');
+
+			while (*p)
+				PCHAR(*p--);
+
+			if (ladjust)
+				while (width-- > 0)
+					PCHAR(' ');
+
+			break;
+		default:
+			while (percent < fmt)
+				PCHAR(*percent++);
+			/*
+			 * Since we ignore an formatting argument it is no
+			 * longer safe to obey the remaining formatting
+			 * arguments as the arguments will no longer match
+			 * the format specs.
+			 */
+			stop = 1;
+			break;
+		}
+	}
+#undef PCHAR
+}
+#else /* defined(USE_ELF) */
+#error not supported
+#endif
diff --git a/addr2line.h b/addr2line.h
new file mode 100644
index 0000000000..f09b665800
--- /dev/null
+++ b/addr2line.h
@@ -0,0 +1,20 @@
+#ifndef RUBY_ADDR2LINE_H
+#define RUBY_ADDR2LINE_H
+/**********************************************************************
+
+  addr2line.h -
+
+  $Author$
+
+  Copyright (C) 2010 Shinichiro Hamaji
+
+**********************************************************************/
+
+#if (defined(USE_ELF) || defined(HAVE_MACH_O_LOADER_H))
+
+void
+rb_dump_backtrace_with_lines(int num_traces, void **traces);
+
+#endif /* USE_ELF */
+
+#endif /* RUBY_ADDR2LINE_H */
diff --git a/appveyor.yml b/appveyor.yml
new file mode 100644
index 0000000000..78e3102008
--- /dev/null
+++ b/appveyor.yml
@@ -0,0 +1,104 @@
+---
+version: '{build}'
+init:
+  - git config --global user.name git
+  - git config --global user.email svn-admin@ruby-lang.org
+clone_depth: 10
+platform:
+  - x64
+environment:
+  ruby_version: "24-%Platform%"
+  matrix:
+    - build: vs
+      vs: 120
+      ssl: OpenSSL
+      APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2015
+      GEMS_FOR_TEST: ""
+    - build: vs
+      vs: 140
+      ssl: OpenSSL-v111
+      APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2015
+      GEMS_FOR_TEST: ""
+  RELINE_TEST_ENCODING: "Windows-31J"
+  UPDATE_UNICODE: "UNICODE_FILES=. UNICODE_PROPERTY_FILES=. UNICODE_AUXILIARY_FILES=. UNICODE_EMOJI_FILES=."
+cache:
+  - c:\Tools\vcpkg\installed\
+for:
+-
+  matrix:
+    only:
+      - build: vs
+  install:
+    - ver
+    - chcp
+    - SET BITS=%Platform:x86=32%
+    - SET BITS=%BITS:x=%
+    - SET OPENSSL_DIR=C:\%ssl%-Win%BITS%
+    - cd C:\Tools\vcpkg
+    - git pull -q
+    - .\bootstrap-vcpkg.bat
+    - cd %APPVEYOR_BUILD_FOLDER%
+    - vcpkg --triplet %Platform%-windows install libffi libyaml zlib
+    - set PATH=c:\Tools\vcpkg\installed\%Platform%-windows\bin;%PATH%
+    - CALL SET vcvars=%%^VS%VS%COMNTOOLS^%%..\..\VC\vcvarsall.bat
+    - SET vcvars
+    - '"%vcvars%" %Platform:x64=amd64%'
+    - SET ruby_path=C:\Ruby%ruby_version:-x86=%
+    - SET PATH=\usr\local\bin;%ruby_path%\bin;%PATH%;C:\msys64\mingw64\bin;C:\msys64\usr\bin
+    - ruby --version
+    - 'cl'
+    - echo> Makefile srcdir=.
+    - echo>> Makefile MSC_VER=0
+    - echo>> Makefile RT=none
+    - echo>> Makefile RT_VER=0
+    - echo>> Makefile BUILTIN_ENCOBJS=nul
+    - type win32\Makefile.sub >> Makefile
+    - nmake %mflags% touch-unicode-files
+    - nmake %mflags% %UPDATE_UNICODE% incs
+    - nmake %mflags% extract-extlibs
+    - del Makefile
+    - mkdir \usr\local\bin
+    - mkdir \usr\local\include
+    - mkdir \usr\local\lib
+    - for %%I in (%OPENSSL_DIR%\*.dll) do mklink /h \usr\local\bin\%%~nxI %%I
+    - attrib +r /s /d
+    - mkdir %Platform%-mswin_%vs%
+  build_script:
+    - cd %APPVEYOR_BUILD_FOLDER%
+    - cd %Platform%-mswin_%vs%
+    - >-
+      ..\win32\configure.bat
+      --without-ext=+,dbm,gdbm,readline
+      --with-opt-dir="/usr/local;c:/Tools/vcpkg/installed/%Platform%-windows"
+      --with-openssl-dir=%OPENSSL_DIR:\=/%
+    - nmake -l
+    - nmake install-nodoc
+    - \usr\bin\ruby -v -e "p :locale => Encoding.find('locale'), :filesystem => Encoding.find('filesystem')"
+    - if not "%GEMS_FOR_TEST%" == "" \usr\bin\gem install --no-document %GEMS_FOR_TEST%
+    - \usr\bin\ruby -ropenssl -e "puts 'Build    ' + OpenSSL::OPENSSL_VERSION, 'Runtime  ' + OpenSSL::OPENSSL_LIBRARY_VERSION"
+  test_script:
+    - set /a JOBS=%NUMBER_OF_PROCESSORS%
+    - nmake -l "TESTOPTS=-v -q" btest
+    - nmake -l "TESTOPTS=-v -q" test-basic
+    - nmake -l "TESTOPTS=-v --timeout-scale=3.0 --excludes=../test/excludes/_appveyor -j%JOBS% --exclude readline --exclude win32ole --exclude test_bignum --exclude test_syntax --exclude test_open-uri --exclude test_bundled_ca" test-all
+    # separately execute tests without -j which may crash worker with -j.
+    - nmake -l "TESTOPTS=-v --timeout-scale=3.0 --excludes=../test/excludes/_appveyor" test-all TESTS="../test/win32ole ../test/ruby/test_bignum.rb ../test/ruby/test_syntax.rb ../test/open-uri/test_open-uri.rb ../test/rubygems/test_bundled_ca.rb"
+    - nmake -l test-spec MSPECOPT=-fs # not using `-j` because sometimes `mspec -j` silently dies on Windows
+notifications:
+  - provider: Webhook
+    method: POST
+    url:
+      secure: CcFlJNDJ/a6to7u3Z4Fnz6dScEPNx7hTha2GkSRlV+1U6dqmxY/7uBcLXYb9gR3jfQk6w+2o/HrjNAyXMNGU/JOka3s2WRI4VKitzM+lQ08owvJIh0R7LxrGH0J2e81U # ruby-lang slack: ruby/simpler-alerts-bot
+    body: >-
+      {{^isPullRequest}}
+        {
+          "ci": "AppVeyor CI",
+          "env": "Visual Studio 2013 / 2015",
+          "url": "{{buildUrl}}",
+          "commit": "{{commitId}}",
+          "branch": "{{branch}}"
+        }
+      {{/isPullRequest}}
+    on_build_success: false
+    on_build_failure: true
+    on_build_status_changed: false
diff --git a/array.c b/array.c
index a9de53f228..b48a6431e7 100644
--- a/array.c
+++ b/array.c
@@ -1,26 +1,263 @@
-/************************************************
+/**********************************************************************
 
   array.c -
 
   $Author$
-  $Date$
   created at: Fri Aug  6 09:46:12 JST 1993
 
-  Copyright (C) 1993-1999 Yukihiro Matsumoto
-
-************************************************/
-
-#include "ruby.h"
-#include "util.h"
+  Copyright (C) 1993-2007 Yukihiro Matsumoto
+  Copyright (C) 2000  Network Applied Communication Laboratory, Inc.
+  Copyright (C) 2000  Information-technology Promotion Agency, Japan
+
+**********************************************************************/
+
+#include "debug_counter.h"
+#include "id.h"
+#include "internal.h"
+#include "internal/array.h"
+#include "internal/compar.h"
+#include "internal/enum.h"
+#include "internal/gc.h"
+#include "internal/hash.h"
+#include "internal/numeric.h"
+#include "internal/object.h"
+#include "internal/proc.h"
+#include "internal/rational.h"
+#include "internal/vm.h"
+#include "probes.h"
+#include "ruby/encoding.h"
+#include "ruby/st.h"
+#include "ruby/util.h"
+#include "transient_heap.h"
+#include "builtin.h"
+
+#if !ARRAY_DEBUG
+# undef NDEBUG
+# define NDEBUG
+#endif
+#include "ruby_assert.h"
 
 VALUE rb_cArray;
 
+/* for OPTIMIZED_CMP: */
+#define id_cmp idCmp
+
 #define ARY_DEFAULT_SIZE 16
+#define ARY_MAX_SIZE (LONG_MAX / (int)sizeof(VALUE))
+#define SMALL_ARRAY_LEN 16
+
+RBIMPL_ATTR_MAYBE_UNUSED()
+static int
+should_be_T_ARRAY(VALUE ary)
+{
+    return RB_TYPE_P(ary, T_ARRAY);
+}
+
+RBIMPL_ATTR_MAYBE_UNUSED()
+static int
+should_not_be_shared_and_embedded(VALUE ary)
+{
+    return !FL_TEST((ary), ELTS_SHARED) || !FL_TEST((ary), RARRAY_EMBED_FLAG);
+}
+
+#define ARY_SHARED_P(ary) \
+  (assert(should_be_T_ARRAY((VALUE)(ary))), \
+   assert(should_not_be_shared_and_embedded((VALUE)ary)), \
+   FL_TEST_RAW((ary),ELTS_SHARED)!=0)
+
+#define ARY_EMBED_P(ary) \
+  (assert(should_be_T_ARRAY((VALUE)(ary))), \
+   assert(should_not_be_shared_and_embedded((VALUE)ary)), \
+   FL_TEST_RAW((ary), RARRAY_EMBED_FLAG) != 0)
+
+#define ARY_HEAP_PTR(a) (assert(!ARY_EMBED_P(a)), RARRAY(a)->as.heap.ptr)
+#define ARY_HEAP_LEN(a) (assert(!ARY_EMBED_P(a)), RARRAY(a)->as.heap.len)
+#define ARY_HEAP_CAPA(a) (assert(!ARY_EMBED_P(a)), assert(!ARY_SHARED_ROOT_P(a)), \
+                          RARRAY(a)->as.heap.aux.capa)
+
+#define ARY_EMBED_PTR(a) (assert(ARY_EMBED_P(a)), RARRAY(a)->as.ary)
+#define ARY_EMBED_LEN(a) \
+    (assert(ARY_EMBED_P(a)), \
+     (long)((RBASIC(a)->flags >> RARRAY_EMBED_LEN_SHIFT) & \
+	 (RARRAY_EMBED_LEN_MASK >> RARRAY_EMBED_LEN_SHIFT)))
+#define ARY_HEAP_SIZE(a) (assert(!ARY_EMBED_P(a)), assert(ARY_OWNS_HEAP_P(a)), ARY_CAPA(a) * sizeof(VALUE))
+
+#define ARY_OWNS_HEAP_P(a) (assert(should_be_T_ARRAY((VALUE)(a))), \
+                            !FL_TEST_RAW((a), ELTS_SHARED|RARRAY_EMBED_FLAG))
+
+#define FL_SET_EMBED(a) do { \
+    assert(!ARY_SHARED_P(a)); \
+    FL_SET((a), RARRAY_EMBED_FLAG); \
+    RARY_TRANSIENT_UNSET(a); \
+    ary_verify(a); \
+} while (0)
+
+#define FL_UNSET_EMBED(ary) FL_UNSET((ary), RARRAY_EMBED_FLAG|RARRAY_EMBED_LEN_MASK)
+#define FL_SET_SHARED(ary) do { \
+    assert(!ARY_EMBED_P(ary)); \
+    FL_SET((ary), ELTS_SHARED); \
+} while (0)
+#define FL_UNSET_SHARED(ary) FL_UNSET((ary), ELTS_SHARED)
+
+#define ARY_SET_PTR(ary, p) do { \
+    assert(!ARY_EMBED_P(ary)); \
+    assert(!OBJ_FROZEN(ary)); \
+    RARRAY(ary)->as.heap.ptr = (p); \
+} while (0)
+#define ARY_SET_EMBED_LEN(ary, n) do { \
+    long tmp_n = (n); \
+    assert(ARY_EMBED_P(ary)); \
+    assert(!OBJ_FROZEN(ary)); \
+    RBASIC(ary)->flags &= ~RARRAY_EMBED_LEN_MASK; \
+    RBASIC(ary)->flags |= (tmp_n) << RARRAY_EMBED_LEN_SHIFT; \
+} while (0)
+#define ARY_SET_HEAP_LEN(ary, n) do { \
+    assert(!ARY_EMBED_P(ary)); \
+    RARRAY(ary)->as.heap.len = (n); \
+} while (0)
+#define ARY_SET_LEN(ary, n) do { \
+    if (ARY_EMBED_P(ary)) { \
+        ARY_SET_EMBED_LEN((ary), (n)); \
+    } \
+    else { \
+        ARY_SET_HEAP_LEN((ary), (n)); \
+    } \
+    assert(RARRAY_LEN(ary) == (n)); \
+} while (0)
+#define ARY_INCREASE_PTR(ary, n) do  { \
+    assert(!ARY_EMBED_P(ary)); \
+    assert(!OBJ_FROZEN(ary)); \
+    RARRAY(ary)->as.heap.ptr += (n); \
+} while (0)
+#define ARY_INCREASE_LEN(ary, n) do  { \
+    assert(!OBJ_FROZEN(ary)); \
+    if (ARY_EMBED_P(ary)) { \
+        ARY_SET_EMBED_LEN((ary), RARRAY_LEN(ary)+(n)); \
+    } \
+    else { \
+        RARRAY(ary)->as.heap.len += (n); \
+    } \
+} while (0)
+
+#define ARY_CAPA(ary) (ARY_EMBED_P(ary) ? RARRAY_EMBED_LEN_MAX : \
+                       ARY_SHARED_ROOT_P(ary) ? RARRAY_LEN(ary) : ARY_HEAP_CAPA(ary))
+#define ARY_SET_CAPA(ary, n) do { \
+    assert(!ARY_EMBED_P(ary)); \
+    assert(!ARY_SHARED_P(ary)); \
+    assert(!OBJ_FROZEN(ary)); \
+    RARRAY(ary)->as.heap.aux.capa = (n); \
+} while (0)
+
+#define ARY_SHARED_ROOT(ary) (assert(ARY_SHARED_P(ary)), RARRAY(ary)->as.heap.aux.shared_root)
+#define ARY_SET_SHARED(ary, value) do { \
+    const VALUE _ary_ = (ary); \
+    const VALUE _value_ = (value); \
+    assert(!ARY_EMBED_P(_ary_)); \
+    assert(ARY_SHARED_P(_ary_)); \
+    assert(ARY_SHARED_ROOT_P(_value_)); \
+    RB_OBJ_WRITE(_ary_, &RARRAY(_ary_)->as.heap.aux.shared_root, _value_); \
+} while (0)
+#define RARRAY_SHARED_ROOT_FLAG FL_USER5
+#define ARY_SHARED_ROOT_P(ary) (assert(should_be_T_ARRAY((VALUE)(ary))), \
+                                FL_TEST_RAW((ary), RARRAY_SHARED_ROOT_FLAG))
+#define ARY_SHARED_ROOT_REFCNT(ary) \
+    (assert(ARY_SHARED_ROOT_P(ary)), RARRAY(ary)->as.heap.aux.capa)
+#define ARY_SHARED_ROOT_OCCUPIED(ary) (ARY_SHARED_ROOT_REFCNT(ary) == 1)
+#define ARY_SET_SHARED_ROOT_REFCNT(ary, value) do { \
+    assert(ARY_SHARED_ROOT_P(ary)); \
+    RARRAY(ary)->as.heap.aux.capa = (value); \
+} while (0)
+#define FL_SET_SHARED_ROOT(ary) do { \
+    assert(!ARY_EMBED_P(ary)); \
+    assert(!RARRAY_TRANSIENT_P(ary)); \
+    FL_SET((ary), RARRAY_SHARED_ROOT_FLAG); \
+} while (0)
+
+static inline void
+ARY_SET(VALUE a, long i, VALUE v)
+{
+    assert(!ARY_SHARED_P(a));
+    assert(!OBJ_FROZEN(a));
+
+    RARRAY_ASET(a, i, v);
+}
+#undef RARRAY_ASET
+
+
+#if ARRAY_DEBUG
+#define ary_verify(ary) ary_verify_(ary, __FILE__, __LINE__)
+
+static VALUE
+ary_verify_(VALUE ary, const char *file, int line)
+{
+    assert(RB_TYPE_P(ary, T_ARRAY));
+
+    if (FL_TEST(ary, ELTS_SHARED)) {
+        VALUE root = RARRAY(ary)->as.heap.aux.shared_root;
+        const VALUE *ptr = ARY_HEAP_PTR(ary);
+        const VALUE *root_ptr = RARRAY_CONST_PTR_TRANSIENT(root);
+        long len = ARY_HEAP_LEN(ary), root_len = RARRAY_LEN(root);
+        assert(FL_TEST(root, RARRAY_SHARED_ROOT_FLAG));
+        assert(root_ptr <= ptr && ptr + len <= root_ptr + root_len);
+        ary_verify(root);
+    }
+    else if (ARY_EMBED_P(ary)) {
+        assert(!RARRAY_TRANSIENT_P(ary));
+        assert(!ARY_SHARED_P(ary));
+        assert(RARRAY_LEN(ary) <= RARRAY_EMBED_LEN_MAX);
+    }
+    else {
+#if 1
+        const VALUE *ptr = RARRAY_CONST_PTR_TRANSIENT(ary);
+        long i, len = RARRAY_LEN(ary);
+        volatile VALUE v;
+        if (len > 1) len = 1; /* check only HEAD */
+        for (i=0; i<len; i++) {
+            v = ptr[i]; /* access check */
+        }
+        v = v;
+#endif
+    }
+
+#if USE_TRANSIENT_HEAP
+    if (RARRAY_TRANSIENT_P(ary)) {
+        assert(rb_transient_heap_managed_ptr_p(RARRAY_CONST_PTR_TRANSIENT(ary)));
+    }
+#endif
+
+    rb_transient_heap_verify();
+
+    return ary;
+}
+
+void
+rb_ary_verify(VALUE ary)
+{
+    ary_verify(ary);
+}
+#else
+#define ary_verify(ary) ((void)0)
+#endif
+
+VALUE *
+rb_ary_ptr_use_start(VALUE ary)
+{
+#if ARRAY_DEBUG
+    FL_SET_RAW(ary, RARRAY_PTR_IN_USE_FLAG);
+#endif
+    return (VALUE *)RARRAY_CONST_PTR_TRANSIENT(ary);
+}
 
 void
-rb_mem_clear(mem, size)
-    register VALUE *mem;
-    register size_t size;
+rb_ary_ptr_use_end(VALUE ary)
+{
+#if ARRAY_DEBUG
+    FL_UNSET_RAW(ary, RARRAY_PTR_IN_USE_FLAG);
+#endif
+}
+
+void
+rb_mem_clear(VALUE *mem, long size)
 {
     while (size--) {
 	*mem++ = Qnil;
@@ -28,1233 +265,4872 @@ rb_mem_clear(mem, size)
 }
 
 static void
-memfill(mem, size, val)
-    register VALUE *mem;
-    register size_t size;
-    register VALUE val;
+ary_mem_clear(VALUE ary, long beg, long size)
+{
+    RARRAY_PTR_USE_TRANSIENT(ary, ptr, {
+	rb_mem_clear(ptr + beg, size);
+    });
+}
+
+static inline void
+memfill(register VALUE *mem, register long size, register VALUE val)
 {
     while (size--) {
 	*mem++ = val;
     }
 }
 
-#define ARY_FREEZE   FL_USER1
-#define ARY_TMPLOCK  FL_USER2
+static void
+ary_memfill(VALUE ary, long beg, long size, VALUE val)
+{
+    RARRAY_PTR_USE_TRANSIENT(ary, ptr, {
+	memfill(ptr + beg, size, val);
+	RB_OBJ_WRITTEN(ary, Qundef, val);
+    });
+}
+
+static void
+ary_memcpy0(VALUE ary, long beg, long argc, const VALUE *argv, VALUE buff_owner_ary)
+{
+    assert(!ARY_SHARED_P(buff_owner_ary));
+
+    if (argc > (int)(128/sizeof(VALUE)) /* is magic number (cache line size) */) {
+        rb_gc_writebarrier_remember(buff_owner_ary);
+        RARRAY_PTR_USE_TRANSIENT(ary, ptr, {
+            MEMCPY(ptr+beg, argv, VALUE, argc);
+        });
+    }
+    else {
+        int i;
+        RARRAY_PTR_USE_TRANSIENT(ary, ptr, {
+            for (i=0; i<argc; i++) {
+                RB_OBJ_WRITE(buff_owner_ary, &ptr[i+beg], argv[i]);
+            }
+        });
+    }
+}
+
+static void
+ary_memcpy(VALUE ary, long beg, long argc, const VALUE *argv)
+{
+    ary_memcpy0(ary, beg, argc, argv, ary);
+}
+
+static VALUE *
+ary_heap_alloc(VALUE ary, size_t capa)
+{
+    VALUE *ptr = rb_transient_heap_alloc(ary, sizeof(VALUE) * capa);
+
+    if (ptr != NULL) {
+        RARY_TRANSIENT_SET(ary);
+    }
+    else {
+        RARY_TRANSIENT_UNSET(ary);
+        ptr = ALLOC_N(VALUE, capa);
+    }
+
+    return ptr;
+}
 
 static void
-rb_ary_modify(ary)
-    VALUE ary;
+ary_heap_free_ptr(VALUE ary, const VALUE *ptr, long size)
 {
-    if (FL_TEST(ary, ARY_FREEZE))
-	rb_raise(rb_eTypeError, "can't modify frozen array");
-    if (FL_TEST(ary, ARY_TMPLOCK))
-	rb_raise(rb_eTypeError, "can't modify array during sort");
-    if (!FL_TEST(ary, FL_TAINT) && rb_safe_level() >= 4)
-	rb_raise(rb_eSecurityError, "Insecure: can't modify array");
+    if (RARRAY_TRANSIENT_P(ary)) {
+        /* ignore it */
+    }
+    else {
+        ruby_sized_xfree((void *)ptr, size);
+    }
 }
 
-VALUE
-rb_ary_freeze(ary)
-    VALUE ary;
+static void
+ary_heap_free(VALUE ary)
 {
-    FL_SET(ary, ARY_FREEZE);
-    return ary;
+    if (RARRAY_TRANSIENT_P(ary)) {
+        RARY_TRANSIENT_UNSET(ary);
+    }
+    else {
+        ary_heap_free_ptr(ary, ARY_HEAP_PTR(ary), ARY_HEAP_SIZE(ary));
+    }
+}
+
+static void
+ary_heap_realloc(VALUE ary, size_t new_capa)
+{
+    size_t old_capa = ARY_HEAP_CAPA(ary);
+
+    if (RARRAY_TRANSIENT_P(ary)) {
+        if (new_capa <= old_capa) {
+            /* do nothing */
+        }
+        else {
+            VALUE *new_ptr = rb_transient_heap_alloc(ary, sizeof(VALUE) * new_capa);
+
+            if (new_ptr == NULL) {
+                new_ptr = ALLOC_N(VALUE, new_capa);
+                RARY_TRANSIENT_UNSET(ary);
+            }
+
+            MEMCPY(new_ptr, ARY_HEAP_PTR(ary), VALUE, old_capa);
+            ARY_SET_PTR(ary, new_ptr);
+        }
+    }
+    else {
+        SIZED_REALLOC_N(RARRAY(ary)->as.heap.ptr, VALUE, new_capa, old_capa);
+    }
+    ary_verify(ary);
+}
+
+#if USE_TRANSIENT_HEAP
+static inline void
+rb_ary_transient_heap_evacuate_(VALUE ary, int transient, int promote)
+{
+    if (transient) {
+        VALUE *new_ptr;
+        const VALUE *old_ptr = ARY_HEAP_PTR(ary);
+        long capa = ARY_HEAP_CAPA(ary);
+        long len  = ARY_HEAP_LEN(ary);
+
+        if (ARY_SHARED_ROOT_P(ary)) {
+            capa = len;
+        }
+
+        assert(ARY_OWNS_HEAP_P(ary));
+        assert(RARRAY_TRANSIENT_P(ary));
+        assert(!ARY_PTR_USING_P(ary));
+
+        if (promote) {
+            new_ptr = ALLOC_N(VALUE, capa);
+            RARY_TRANSIENT_UNSET(ary);
+        }
+        else {
+            new_ptr = ary_heap_alloc(ary, capa);
+        }
+
+        MEMCPY(new_ptr, old_ptr, VALUE, capa);
+        /* do not use ARY_SET_PTR() because they assert !frozen */
+        RARRAY(ary)->as.heap.ptr = new_ptr;
+    }
+
+    ary_verify(ary);
+}
+
+void
+rb_ary_transient_heap_evacuate(VALUE ary, int promote)
+{
+    rb_ary_transient_heap_evacuate_(ary, RARRAY_TRANSIENT_P(ary), promote);
+}
+
+void
+rb_ary_detransient(VALUE ary)
+{
+    assert(RARRAY_TRANSIENT_P(ary));
+    rb_ary_transient_heap_evacuate_(ary, TRUE, TRUE);
+}
+#else
+void
+rb_ary_detransient(VALUE ary)
+{
+    /* do nothing */
+}
+#endif
+
+static void
+ary_resize_capa(VALUE ary, long capacity)
+{
+    assert(RARRAY_LEN(ary) <= capacity);
+    assert(!OBJ_FROZEN(ary));
+    assert(!ARY_SHARED_P(ary));
+
+    if (capacity > RARRAY_EMBED_LEN_MAX) {
+        if (ARY_EMBED_P(ary)) {
+            long len = ARY_EMBED_LEN(ary);
+            VALUE *ptr = ary_heap_alloc(ary, capacity);
+
+            MEMCPY(ptr, ARY_EMBED_PTR(ary), VALUE, len);
+            FL_UNSET_EMBED(ary);
+            ARY_SET_PTR(ary, ptr);
+            ARY_SET_HEAP_LEN(ary, len);
+        }
+        else {
+            ary_heap_realloc(ary, capacity);
+        }
+        ARY_SET_CAPA(ary, capacity);
+    }
+    else {
+        if (!ARY_EMBED_P(ary)) {
+            long len = ARY_HEAP_LEN(ary);
+            long old_capa = ARY_HEAP_CAPA(ary);
+            const VALUE *ptr = ARY_HEAP_PTR(ary);
+
+            if (len > capacity) len = capacity;
+            MEMCPY((VALUE *)RARRAY(ary)->as.ary, ptr, VALUE, len);
+            ary_heap_free_ptr(ary, ptr, old_capa);
+
+            FL_SET_EMBED(ary);
+            ARY_SET_LEN(ary, len);
+        }
+    }
+
+    ary_verify(ary);
+}
+
+static inline void
+ary_shrink_capa(VALUE ary)
+{
+    long capacity = ARY_HEAP_LEN(ary);
+    long old_capa = ARY_HEAP_CAPA(ary);
+    assert(!ARY_SHARED_P(ary));
+    assert(old_capa >= capacity);
+    if (old_capa > capacity) ary_heap_realloc(ary, capacity);
+
+    ary_verify(ary);
+}
+
+static void
+ary_double_capa(VALUE ary, long min)
+{
+    long new_capa = ARY_CAPA(ary) / 2;
+
+    if (new_capa < ARY_DEFAULT_SIZE) {
+	new_capa = ARY_DEFAULT_SIZE;
+    }
+    if (new_capa >= ARY_MAX_SIZE - min) {
+	new_capa = (ARY_MAX_SIZE - min) / 2;
+    }
+    new_capa += min;
+    ary_resize_capa(ary, new_capa);
+
+    ary_verify(ary);
+}
+
+static void
+rb_ary_decrement_share(VALUE shared_root)
+{
+    if (shared_root) {
+        long num = ARY_SHARED_ROOT_REFCNT(shared_root) - 1;
+	if (num == 0) {
+            rb_ary_free(shared_root);
+            rb_gc_force_recycle(shared_root);
+	}
+	else if (num > 0) {
+            ARY_SET_SHARED_ROOT_REFCNT(shared_root, num);
+	}
+    }
+}
+
+static void
+rb_ary_unshare(VALUE ary)
+{
+    VALUE shared_root = RARRAY(ary)->as.heap.aux.shared_root;
+    rb_ary_decrement_share(shared_root);
+    FL_UNSET_SHARED(ary);
+}
+
+static inline void
+rb_ary_unshare_safe(VALUE ary)
+{
+    if (ARY_SHARED_P(ary) && !ARY_EMBED_P(ary)) {
+	rb_ary_unshare(ary);
+    }
 }
 
 static VALUE
-rb_ary_frozen_p(ary)
-    VALUE ary;
+rb_ary_increment_share(VALUE shared_root)
+{
+    long num = ARY_SHARED_ROOT_REFCNT(shared_root);
+    if (num >= 0) {
+        ARY_SET_SHARED_ROOT_REFCNT(shared_root, num + 1);
+    }
+    return shared_root;
+}
+
+static void
+rb_ary_set_shared(VALUE ary, VALUE shared_root)
+{
+    rb_ary_increment_share(shared_root);
+    FL_SET_SHARED(ary);
+    RB_DEBUG_COUNTER_INC(obj_ary_shared_create);
+    ARY_SET_SHARED(ary, shared_root);
+}
+
+static inline void
+rb_ary_modify_check(VALUE ary)
+{
+    rb_check_frozen(ary);
+    ary_verify(ary);
+}
+
+void
+rb_ary_cancel_sharing(VALUE ary)
+{
+    if (ARY_SHARED_P(ary)) {
+        long shared_len, len = RARRAY_LEN(ary);
+        VALUE shared_root = ARY_SHARED_ROOT(ary);
+
+        ary_verify(shared_root);
+
+        if (len <= RARRAY_EMBED_LEN_MAX) {
+            const VALUE *ptr = ARY_HEAP_PTR(ary);
+            FL_UNSET_SHARED(ary);
+            FL_SET_EMBED(ary);
+            MEMCPY((VALUE *)ARY_EMBED_PTR(ary), ptr, VALUE, len);
+            rb_ary_decrement_share(shared_root);
+            ARY_SET_EMBED_LEN(ary, len);
+        }
+        else if (ARY_SHARED_ROOT_OCCUPIED(shared_root) && len > ((shared_len = RARRAY_LEN(shared_root))>>1)) {
+            long shift = RARRAY_CONST_PTR_TRANSIENT(ary) - RARRAY_CONST_PTR_TRANSIENT(shared_root);
+            FL_UNSET_SHARED(ary);
+            ARY_SET_PTR(ary, RARRAY_CONST_PTR_TRANSIENT(shared_root));
+            ARY_SET_CAPA(ary, shared_len);
+            RARRAY_PTR_USE_TRANSIENT(ary, ptr, {
+                MEMMOVE(ptr, ptr+shift, VALUE, len);
+            });
+            FL_SET_EMBED(shared_root);
+            rb_ary_decrement_share(shared_root);
+        }
+        else {
+            VALUE *ptr = ary_heap_alloc(ary, len);
+            MEMCPY(ptr, ARY_HEAP_PTR(ary), VALUE, len);
+            rb_ary_unshare(ary);
+            ARY_SET_CAPA(ary, len);
+            ARY_SET_PTR(ary, ptr);
+        }
+
+        rb_gc_writebarrier_remember(ary);
+    }
+    ary_verify(ary);
+}
+
+void
+rb_ary_modify(VALUE ary)
+{
+    rb_ary_modify_check(ary);
+    rb_ary_cancel_sharing(ary);
+}
+
+static VALUE
+ary_ensure_room_for_push(VALUE ary, long add_len)
+{
+    long old_len = RARRAY_LEN(ary);
+    long new_len = old_len + add_len;
+    long capa;
+
+    if (old_len > ARY_MAX_SIZE - add_len) {
+	rb_raise(rb_eIndexError, "index %ld too big", new_len);
+    }
+    if (ARY_SHARED_P(ary)) {
+	if (new_len > RARRAY_EMBED_LEN_MAX) {
+            VALUE shared_root = ARY_SHARED_ROOT(ary);
+            if (ARY_SHARED_ROOT_OCCUPIED(shared_root)) {
+                if (ARY_HEAP_PTR(ary) - RARRAY_CONST_PTR_TRANSIENT(shared_root) + new_len <= RARRAY_LEN(shared_root)) {
+		    rb_ary_modify_check(ary);
+
+                    ary_verify(ary);
+                    ary_verify(shared_root);
+                    return shared_root;
+		}
+		else {
+		    /* if array is shared, then it is likely it participate in push/shift pattern */
+		    rb_ary_modify(ary);
+		    capa = ARY_CAPA(ary);
+		    if (new_len > capa - (capa >> 6)) {
+			ary_double_capa(ary, new_len);
+		    }
+                    ary_verify(ary);
+		    return ary;
+		}
+	    }
+	}
+        ary_verify(ary);
+        rb_ary_modify(ary);
+    }
+    else {
+	rb_ary_modify_check(ary);
+    }
+    capa = ARY_CAPA(ary);
+    if (new_len > capa) {
+	ary_double_capa(ary, new_len);
+    }
+
+    ary_verify(ary);
+    return ary;
+}
+
+/*
+ *  call-seq:
+ *    array.freeze -> self
+ *
+ *  Freezes +self+; returns +self+:
+ *    a = []
+ *    a.frozen? # => false
+ *    a.freeze
+ *    a.frozen? # => true
+ *
+ *  An attempt to modify a frozen \Array raises FrozenError.
+ */
+
+VALUE
+rb_ary_freeze(VALUE ary)
+{
+    return rb_obj_freeze(ary);
+}
+
+/* This can be used to take a snapshot of an array (with
+   e.g. rb_ary_replace) and check later whether the array has been
+   modified from the snapshot.  The snapshot is cheap, though if
+   something does modify the array it will pay the cost of copying
+   it.  If Array#pop or Array#shift has been called, the array will
+   be still shared with the snapshot, but the array length will
+   differ. */
+VALUE
+rb_ary_shared_with_p(VALUE ary1, VALUE ary2)
 {
-    if (FL_TEST(ary, ARY_FREEZE|ARY_TMPLOCK))
+    if (!ARY_EMBED_P(ary1) && ARY_SHARED_P(ary1) &&
+	!ARY_EMBED_P(ary2) && ARY_SHARED_P(ary2) &&
+        RARRAY(ary1)->as.heap.aux.shared_root == RARRAY(ary2)->as.heap.aux.shared_root &&
+	RARRAY(ary1)->as.heap.len == RARRAY(ary2)->as.heap.len) {
 	return Qtrue;
+    }
     return Qfalse;
 }
 
-VALUE
-rb_ary_new2(len)
-    int len;
+static VALUE
+ary_alloc(VALUE klass)
 {
-    NEWOBJ(ary, struct RArray);
-    OBJSETUP(ary, rb_cArray, T_ARRAY);
+    NEWOBJ_OF(ary, struct RArray, klass, T_ARRAY | RARRAY_EMBED_FLAG | (RGENGC_WB_PROTECTED_ARRAY ? FL_WB_PROTECTED : 0));
+    /* Created array is:
+     *   FL_SET_EMBED((VALUE)ary);
+     *   ARY_SET_EMBED_LEN((VALUE)ary, 0);
+     */
+    return (VALUE)ary;
+}
 
-    if (len < 0) {
+static VALUE
+empty_ary_alloc(VALUE klass)
+{
+    RUBY_DTRACE_CREATE_HOOK(ARRAY, 0);
+    return ary_alloc(klass);
+}
+
+static VALUE
+ary_new(VALUE klass, long capa)
+{
+    VALUE ary,*ptr;
+
+    if (capa < 0) {
 	rb_raise(rb_eArgError, "negative array size (or size too big)");
     }
-    if (len > 0 && len*sizeof(VALUE) <= 0) {
+    if (capa > ARY_MAX_SIZE) {
 	rb_raise(rb_eArgError, "array size too big");
     }
-    ary->len = 0;
-    ary->capa = len;
-    ary->ptr = 0;
-    ary->ptr = ALLOC_N(VALUE, len);
 
-    return (VALUE)ary;
+    RUBY_DTRACE_CREATE_HOOK(ARRAY, capa);
+
+    ary = ary_alloc(klass);
+    if (capa > RARRAY_EMBED_LEN_MAX) {
+        ptr = ary_heap_alloc(ary, capa);
+        FL_UNSET_EMBED(ary);
+        ARY_SET_PTR(ary, ptr);
+        ARY_SET_CAPA(ary, capa);
+        ARY_SET_HEAP_LEN(ary, 0);
+    }
+
+    return ary;
 }
 
 VALUE
-rb_ary_new()
+rb_ary_new_capa(long capa)
 {
-    return rb_ary_new2(ARY_DEFAULT_SIZE);
+    return ary_new(rb_cArray, capa);
 }
 
-#ifdef HAVE_STDARG_PROTOTYPES
-#include <stdarg.h>
-#define va_init_list(a,b) va_start(a,b)
-#else
-#include <varargs.h>
-#define va_init_list(a,b) va_start(a)
-#endif
+VALUE
+rb_ary_new(void)
+{
+    return rb_ary_new2(RARRAY_EMBED_LEN_MAX);
+}
 
 VALUE
-#ifdef HAVE_STDARG_PROTOTYPES
-rb_ary_new3(int n, ...)
-#else
-rb_ary_new3(n, va_alist)
-    int n;
-    va_dcl
-#endif
+(rb_ary_new_from_args)(long n, ...)
 {
     va_list ar;
     VALUE ary;
-    int i;
+    long i;
 
-    if (n < 0) {
-	rb_raise(rb_eIndexError, "negative number of items(%d)", n);
-    }
-    ary = rb_ary_new2(n<ARY_DEFAULT_SIZE?ARY_DEFAULT_SIZE:n);
+    ary = rb_ary_new2(n);
 
-    va_init_list(ar, n);
+    va_start(ar, n);
     for (i=0; i<n; i++) {
-	RARRAY(ary)->ptr[i] = va_arg(ar, VALUE);
+	ARY_SET(ary, i, va_arg(ar, VALUE));
     }
     va_end(ar);
 
-    RARRAY(ary)->len = n;
+    ARY_SET_LEN(ary, n);
     return ary;
 }
 
-VALUE
-rb_ary_new4(n, elts)
-    int n;
-    VALUE *elts;
+MJIT_FUNC_EXPORTED VALUE
+rb_ary_tmp_new_from_values(VALUE klass, long n, const VALUE *elts)
 {
     VALUE ary;
 
-    ary = rb_ary_new2(n);
-    if (elts) {
-	MEMCPY(RARRAY(ary)->ptr, elts, VALUE, n);
+    ary = ary_new(klass, n);
+    if (n > 0 && elts) {
+	ary_memcpy(ary, 0, n, elts);
+	ARY_SET_LEN(ary, n);
     }
-    RARRAY(ary)->len = n;
 
     return ary;
 }
 
 VALUE
-rb_assoc_new(car, cdr)
-    VALUE car, cdr;
+rb_ary_new_from_values(long n, const VALUE *elts)
+{
+    return rb_ary_tmp_new_from_values(rb_cArray, n, elts);
+}
+
+static VALUE
+ec_ary_alloc(rb_execution_context_t *ec, VALUE klass)
+{
+    RB_EC_NEWOBJ_OF(ec, ary, struct RArray, klass, T_ARRAY | RARRAY_EMBED_FLAG | (RGENGC_WB_PROTECTED_ARRAY ? FL_WB_PROTECTED : 0));
+    /* Created array is:
+     *   FL_SET_EMBED((VALUE)ary);
+     *   ARY_SET_EMBED_LEN((VALUE)ary, 0);
+     */
+    return (VALUE)ary;
+}
+
+static VALUE
+ec_ary_new(rb_execution_context_t *ec, VALUE klass, long capa)
+{
+    VALUE ary,*ptr;
+
+    if (capa < 0) {
+	rb_raise(rb_eArgError, "negative array size (or size too big)");
+    }
+    if (capa > ARY_MAX_SIZE) {
+	rb_raise(rb_eArgError, "array size too big");
+    }
+
+    RUBY_DTRACE_CREATE_HOOK(ARRAY, capa);
+
+    ary = ec_ary_alloc(ec, klass);
+
+    if (capa > RARRAY_EMBED_LEN_MAX) {
+        ptr = ary_heap_alloc(ary, capa);
+        FL_UNSET_EMBED(ary);
+        ARY_SET_PTR(ary, ptr);
+        ARY_SET_CAPA(ary, capa);
+        ARY_SET_HEAP_LEN(ary, 0);
+    }
+
+    return ary;
+}
+
+VALUE
+rb_ec_ary_new_from_values(rb_execution_context_t *ec, long n, const VALUE *elts)
 {
     VALUE ary;
 
-    ary = rb_ary_new2(2);
-    RARRAY(ary)->ptr[0] = car;
-    RARRAY(ary)->ptr[1] = cdr;
-    RARRAY(ary)->len = 2;
+    ary = ec_ary_new(ec, rb_cArray, n);
+    if (n > 0 && elts) {
+	ary_memcpy(ary, 0, n, elts);
+	ARY_SET_LEN(ary, n);
+    }
+
+    return ary;
+}
+
+VALUE
+rb_ary_tmp_new(long capa)
+{
+    VALUE ary = ary_new(0, capa);
+    rb_ary_transient_heap_evacuate(ary, TRUE);
+    return ary;
+}
 
+VALUE
+rb_ary_tmp_new_fill(long capa)
+{
+    VALUE ary = ary_new(0, capa);
+    ary_memfill(ary, 0, capa, Qnil);
+    ARY_SET_LEN(ary, capa);
+    rb_ary_transient_heap_evacuate(ary, TRUE);
     return ary;
 }
 
+void
+rb_ary_free(VALUE ary)
+{
+    if (ARY_OWNS_HEAP_P(ary)) {
+        if (USE_DEBUG_COUNTER &&
+            !ARY_SHARED_ROOT_P(ary) &&
+            ARY_HEAP_CAPA(ary) > RARRAY_LEN(ary)) {
+            RB_DEBUG_COUNTER_INC(obj_ary_extracapa);
+        }
+
+        if (RARRAY_TRANSIENT_P(ary)) {
+            RB_DEBUG_COUNTER_INC(obj_ary_transient);
+        }
+        else {
+            RB_DEBUG_COUNTER_INC(obj_ary_ptr);
+            ary_heap_free(ary);
+        }
+    }
+    else {
+        RB_DEBUG_COUNTER_INC(obj_ary_embed);
+    }
+
+    if (ARY_SHARED_P(ary)) {
+        RB_DEBUG_COUNTER_INC(obj_ary_shared);
+    }
+    if (ARY_SHARED_ROOT_P(ary) && ARY_SHARED_ROOT_OCCUPIED(ary)) {
+        RB_DEBUG_COUNTER_INC(obj_ary_shared_root_occupied);
+    }
+}
+
+RUBY_FUNC_EXPORTED size_t
+rb_ary_memsize(VALUE ary)
+{
+    if (ARY_OWNS_HEAP_P(ary)) {
+	return ARY_CAPA(ary) * sizeof(VALUE);
+    }
+    else {
+	return 0;
+    }
+}
+
+static inline void
+ary_discard(VALUE ary)
+{
+    rb_ary_free(ary);
+    RBASIC(ary)->flags |= RARRAY_EMBED_FLAG;
+    RBASIC(ary)->flags &= ~(RARRAY_EMBED_LEN_MASK | RARRAY_TRANSIENT_FLAG);
+}
+
 static VALUE
-rb_ary_s_new(argc, argv, klass)
-    int argc;
-    VALUE *argv;
-    VALUE klass;
+ary_make_shared(VALUE ary)
 {
-    int len = 0;
-    VALUE size, val;
-    NEWOBJ(ary, struct RArray);
-    OBJSETUP(ary, klass, T_ARRAY);
+    assert(!ARY_EMBED_P(ary));
+    ary_verify(ary);
 
-    ary->len = 0;
-    ary->ptr = 0;
-    if (rb_scan_args(argc, argv, "02", &size, &val) == 0) {
-	ary->capa = ARY_DEFAULT_SIZE;
+    if (ARY_SHARED_P(ary)) {
+        return ARY_SHARED_ROOT(ary);
+    }
+    else if (ARY_SHARED_ROOT_P(ary)) {
+	return ary;
+    }
+    else if (OBJ_FROZEN(ary)) {
+        rb_ary_transient_heap_evacuate(ary, TRUE);
+	ary_shrink_capa(ary);
+	FL_SET_SHARED_ROOT(ary);
+        ARY_SET_SHARED_ROOT_REFCNT(ary, 1);
+	return ary;
     }
     else {
-	int capa = NUM2INT(size);
+	long capa = ARY_CAPA(ary), len = RARRAY_LEN(ary);
+        const VALUE *ptr;
+	NEWOBJ_OF(shared, struct RArray, 0, T_ARRAY | (RGENGC_WB_PROTECTED_ARRAY ? FL_WB_PROTECTED : 0));
+        VALUE vshared = (VALUE)shared;
+
+        rb_ary_transient_heap_evacuate(ary, TRUE);
+        ptr = ARY_HEAP_PTR(ary);
+
+        FL_UNSET_EMBED(vshared);
+        ARY_SET_LEN(vshared, capa);
+        ARY_SET_PTR(vshared, ptr);
+        ary_mem_clear(vshared, len, capa - len);
+        FL_SET_SHARED_ROOT(vshared);
+        ARY_SET_SHARED_ROOT_REFCNT(vshared, 1);
+	FL_SET_SHARED(ary);
+        RB_DEBUG_COUNTER_INC(obj_ary_shared_create);
+        ARY_SET_SHARED(ary, vshared);
+        OBJ_FREEZE(vshared);
+
+        ary_verify(vshared);
+        ary_verify(ary);
+
+        return vshared;
+    }
+}
 
-	if (capa < 0) {
-	    rb_raise(rb_eArgError, "negative array size");
-	}
-	if (capa > 0 && capa*sizeof(VALUE) <= 0) {
-	    rb_raise(rb_eArgError, "array size too big");
-	}
-	ary->capa = capa;
-	len = capa;
+static VALUE
+ary_make_substitution(VALUE ary)
+{
+    long len = RARRAY_LEN(ary);
+
+    if (len <= RARRAY_EMBED_LEN_MAX) {
+	VALUE subst = rb_ary_new2(len);
+        ary_memcpy(subst, 0, len, RARRAY_CONST_PTR_TRANSIENT(ary));
+        ARY_SET_EMBED_LEN(subst, len);
+        return subst;
+    }
+    else {
+        return rb_ary_increment_share(ary_make_shared(ary));
     }
-    ary->ptr = ALLOC_N(VALUE, ary->capa);
-    memfill(ary->ptr, len, val);
-    ary->len = len;
-    rb_obj_call_init((VALUE)ary);
+}
 
-    return (VALUE)ary;
+VALUE
+rb_assoc_new(VALUE car, VALUE cdr)
+{
+    return rb_ary_new3(2, car, cdr);
 }
 
+VALUE
+rb_to_array_type(VALUE ary)
+{
+    return rb_convert_type_with_id(ary, T_ARRAY, "Array", idTo_ary);
+}
+#define to_ary rb_to_array_type
+
+VALUE
+rb_check_array_type(VALUE ary)
+{
+    return rb_check_convert_type_with_id(ary, T_ARRAY, "Array", idTo_ary);
+}
+
+MJIT_FUNC_EXPORTED VALUE
+rb_check_to_array(VALUE ary)
+{
+    return rb_check_convert_type_with_id(ary, T_ARRAY, "Array", idTo_a);
+}
+
+/*
+ *  call-seq:
+ *    Array.try_convert(object) -> object, new_array, or nil
+ *
+ *  If +object+ is an \Array object, returns +object+.
+ *
+ *  Otherwise if +object+ responds to <tt>:to_ary</tt>,
+ *  calls <tt>object.to_ary</tt> and returns the result.
+ *
+ *  Returns +nil+ if +object+ does not respond to <tt>:to_ary</tt>
+ *
+ *  Raises an exception unless <tt>object.to_ary</tt> returns an \Array object.
+ */
+
 static VALUE
-rb_ary_s_create(argc, argv, klass)
-    int argc;
-    VALUE *argv;
-    VALUE klass;
+rb_ary_s_try_convert(VALUE dummy, VALUE ary)
+{
+    return rb_check_array_type(ary);
+}
+
+/*
+ *  call-seq:
+ *    Array.new -> new_empty_array
+ *    Array.new(array) -> new_array
+ *    Array.new(size) -> new_array
+ *    Array.new(size, default_value) -> new_array
+ *    Array.new(size) {|index| ... } -> new_array
+ *
+ *  Returns a new \Array.
+ *
+ *  With no block and no arguments, returns a new empty \Array object.
+ *
+ *  With no block and a single \Array argument +array+,
+ *  returns a new \Array formed from +array+:
+ *    a = Array.new([:foo, 'bar', 2])
+ *    a.class # => Array
+ *    a # => [:foo, "bar", 2]
+ *
+ *  With no block and a single \Integer argument +size+,
+ *  returns a new \Array of the given size
+ *  whose elements are all +nil+:
+ *    a = Array.new(3)
+ *    a # => [nil, nil, nil]
+ *
+ *  With no block and arguments +size+ and +default_value+,
+ *  returns an \Array of the given size;
+ *  each element is that same +default_value+:
+ *    a = Array.new(3, 'x')
+ *    a # => ['x', 'x', 'x']
+ *
+ *  With a block and argument +size+,
+ *  returns an \Array of the given size;
+ *  the block is called with each successive integer +index+;
+ *  the element for that +index+ is the return value from the block:
+ *    a = Array.new(3) {|index| "Element #{index}" }
+ *    a # => ["Element 0", "Element 1", "Element 2"]
+ *
+ *  Raises ArgumentError if +size+ is negative.
+ *
+ *  With a block and no argument,
+ *  or a single argument +0+,
+ *  ignores the block and returns a new empty \Array.
+ */
+
+static VALUE
+rb_ary_initialize(int argc, VALUE *argv, VALUE ary)
 {
-    NEWOBJ(ary, struct RArray);
-    OBJSETUP(ary, klass, T_ARRAY);
+    long len;
+    VALUE size, val;
 
-    ary->len = argc;
-    ary->capa = argc;
+    rb_ary_modify(ary);
     if (argc == 0) {
-	ary->ptr = 0;
+        if (ARY_OWNS_HEAP_P(ary) && ARY_HEAP_PTR(ary) != NULL) {
+            ary_heap_free(ary);
+	}
+        rb_ary_unshare_safe(ary);
+        FL_SET_EMBED(ary);
+	ARY_SET_EMBED_LEN(ary, 0);
+	if (rb_block_given_p()) {
+	    rb_warning("given block not used");
+	}
+	return ary;
+    }
+    rb_scan_args(argc, argv, "02", &size, &val);
+    if (argc == 1 && !FIXNUM_P(size)) {
+	val = rb_check_array_type(size);
+	if (!NIL_P(val)) {
+	    rb_ary_replace(ary, val);
+	    return ary;
+	}
+    }
+
+    len = NUM2LONG(size);
+    /* NUM2LONG() may call size.to_int, ary can be frozen, modified, etc */
+    if (len < 0) {
+	rb_raise(rb_eArgError, "negative array size");
+    }
+    if (len > ARY_MAX_SIZE) {
+	rb_raise(rb_eArgError, "array size too big");
+    }
+    /* recheck after argument conversion */
+    rb_ary_modify(ary);
+    ary_resize_capa(ary, len);
+    if (rb_block_given_p()) {
+	long i;
+
+	if (argc == 2) {
+	    rb_warn("block supersedes default value argument");
+	}
+	for (i=0; i<len; i++) {
+	    rb_ary_store(ary, i, rb_yield(LONG2NUM(i)));
+	    ARY_SET_LEN(ary, i + 1);
+	}
     }
     else {
-	ary->ptr = ALLOC_N(VALUE, argc);
-	MEMCPY(ary->ptr, argv, VALUE, argc);
+	ary_memfill(ary, 0, len, val);
+	ARY_SET_LEN(ary, len);
+    }
+    return ary;
+}
+
+/*
+ * Returns a new array populated with the given objects.
+ *
+ *   Array.[]( 1, 'a', /^A/)  # => [1, "a", /^A/]
+ *   Array[ 1, 'a', /^A/ ]    # => [1, "a", /^A/]
+ *   [ 1, 'a', /^A/ ]         # => [1, "a", /^A/]
+ */
+
+static VALUE
+rb_ary_s_create(int argc, VALUE *argv, VALUE klass)
+{
+    VALUE ary = ary_new(klass, argc);
+    if (argc > 0 && argv) {
+        ary_memcpy(ary, 0, argc, argv);
+        ARY_SET_LEN(ary, argc);
     }
 
-    return (VALUE)ary;
+    return ary;
 }
 
 void
-rb_ary_store(ary, idx, val)
-    VALUE ary;
-    int idx;
-    VALUE val;
+rb_ary_store(VALUE ary, long idx, VALUE val)
 {
-    rb_ary_modify(ary);
+    long len = RARRAY_LEN(ary);
+
     if (idx < 0) {
-	idx = RARRAY(ary)->len + idx;
+	idx += len;
 	if (idx < 0) {
-	    rb_raise(rb_eIndexError, "negative index of array");
+	    rb_raise(rb_eIndexError, "index %ld too small for array; minimum: %ld",
+		     idx - len, -len);
 	}
     }
+    else if (idx >= ARY_MAX_SIZE) {
+	rb_raise(rb_eIndexError, "index %ld too big", idx);
+    }
 
-    if (idx >= RARRAY(ary)->capa) {
-	int capa_inc = RARRAY(ary)->capa / 2;
-	if (capa_inc < ARY_DEFAULT_SIZE) {
-	    capa_inc = ARY_DEFAULT_SIZE;
-	}
-	RARRAY(ary)->capa = idx + capa_inc;
-	REALLOC_N(RARRAY(ary)->ptr, VALUE, RARRAY(ary)->capa);
+    rb_ary_modify(ary);
+    if (idx >= ARY_CAPA(ary)) {
+	ary_double_capa(ary, idx);
     }
-    if (idx > RARRAY(ary)->len) {
-	rb_mem_clear(RARRAY(ary)->ptr+RARRAY(ary)->len,
-		     idx-RARRAY(ary)->len+1);
+    if (idx > len) {
+	ary_mem_clear(ary, len, idx - len + 1);
     }
 
-    if (idx >= RARRAY(ary)->len) {
-	RARRAY(ary)->len = idx + 1;
+    if (idx >= len) {
+	ARY_SET_LEN(ary, idx + 1);
     }
-    RARRAY(ary)->ptr[idx] = val;
+    ARY_SET(ary, idx, val);
 }
 
-VALUE
-rb_ary_push(ary, item)
-    VALUE ary;
-    VALUE item;
+static VALUE
+ary_make_partial(VALUE ary, VALUE klass, long offset, long len)
 {
-    rb_ary_store(ary, RARRAY(ary)->len, item);
-    return ary;
+    assert(offset >= 0);
+    assert(len >= 0);
+    assert(offset+len <= RARRAY_LEN(ary));
+
+    if (len <= RARRAY_EMBED_LEN_MAX) {
+        VALUE result = ary_alloc(klass);
+        ary_memcpy(result, 0, len, RARRAY_CONST_PTR_TRANSIENT(ary) + offset);
+        ARY_SET_EMBED_LEN(result, len);
+        return result;
+    }
+    else {
+        VALUE shared, result = ary_alloc(klass);
+        FL_UNSET_EMBED(result);
+
+        shared = ary_make_shared(ary);
+        ARY_SET_PTR(result, RARRAY_CONST_PTR_TRANSIENT(ary));
+        ARY_SET_LEN(result, RARRAY_LEN(ary));
+        rb_ary_set_shared(result, shared);
+
+        ARY_INCREASE_PTR(result, offset);
+        ARY_SET_LEN(result, len);
+
+        ary_verify(shared);
+        ary_verify(result);
+        return result;
+    }
 }
 
 static VALUE
-rb_ary_push_method(argc, argv, ary)
-    int argc;
-    VALUE *argv;
-    VALUE ary;
+ary_make_partial_step(VALUE ary, VALUE klass, long offset, long len, long step)
+{
+    assert(offset >= 0);
+    assert(len >= 0);
+    assert(offset+len <= RARRAY_LEN(ary));
+    assert(step != 0);
+
+    const VALUE *values = RARRAY_CONST_PTR_TRANSIENT(ary);
+    const long orig_len = len;
+
+    if ((step > 0 && step >= len) || (step < 0 && (step < -len))) {
+        VALUE result = ary_new(klass, 1);
+        VALUE *ptr = (VALUE *)ARY_EMBED_PTR(result);
+        RB_OBJ_WRITE(result, ptr, values[offset]);
+        ARY_SET_EMBED_LEN(result, 1);
+        return result;
+    }
+
+    long ustep = (step < 0) ? -step : step;
+    len = (len + ustep - 1) / ustep;
+
+    long i;
+    long j = offset + ((step > 0) ? 0 : (orig_len - 1));
+    VALUE result = ary_new(klass, len);
+    if (len <= RARRAY_EMBED_LEN_MAX) {
+        VALUE *ptr = (VALUE *)ARY_EMBED_PTR(result);
+        for (i = 0; i < len; ++i) {
+            RB_OBJ_WRITE(result, ptr+i, values[j]);
+            j += step;
+        }
+        ARY_SET_EMBED_LEN(result, len);
+    }
+    else {
+        RARRAY_PTR_USE_TRANSIENT(result, ptr, {
+            for (i = 0; i < len; ++i) {
+                RB_OBJ_WRITE(result, ptr+i, values[j]);
+                j += step;
+            }
+        });
+        ARY_SET_LEN(result, len);
+    }
+
+    return result;
+}
+
+static VALUE
+ary_make_shared_copy(VALUE ary)
+{
+    return ary_make_partial(ary, rb_cArray, 0, RARRAY_LEN(ary));
+}
+
+enum ary_take_pos_flags
 {
-    while (argc--) {
-	rb_ary_store(ary, RARRAY(ary)->len, *argv++);
+    ARY_TAKE_FIRST = 0,
+    ARY_TAKE_LAST = 1
+};
+
+static VALUE
+ary_take_first_or_last(int argc, const VALUE *argv, VALUE ary, enum ary_take_pos_flags last)
+{
+    long n;
+    long len;
+    long offset = 0;
+
+    argc = rb_check_arity(argc, 0, 1);
+    /* the case optional argument is omitted should be handled in
+     * callers of this function.  if another arity case is added,
+     * this arity check needs to rewrite. */
+    RUBY_ASSERT_ALWAYS(argc == 1);
+
+    n = NUM2LONG(argv[0]);
+    len = RARRAY_LEN(ary);
+    if (n > len) {
+	n = len;
+    }
+    else if (n < 0) {
+	rb_raise(rb_eArgError, "negative array size");
+    }
+    if (last) {
+	offset = len - n;
     }
+    return ary_make_partial(ary, rb_cArray, offset, n);
+}
+
+/*
+ *  call-seq:
+ *    array << object -> self
+ *
+ *  Appends +object+ to +self+; returns +self+:
+ *    a = [:foo, 'bar', 2]
+ *    a << :baz # => [:foo, "bar", 2, :baz]
+ *
+ *  Appends +object+ as one element, even if it is another \Array:
+ *    a = [:foo, 'bar', 2]
+ *    a1 = a << [3, 4]
+ *    a1 # => [:foo, "bar", 2, [3, 4]]
+ */
+
+VALUE
+rb_ary_push(VALUE ary, VALUE item)
+{
+    long idx = RARRAY_LEN((ary_verify(ary), ary));
+    VALUE target_ary = ary_ensure_room_for_push(ary, 1);
+    RARRAY_PTR_USE_TRANSIENT(ary, ptr, {
+	RB_OBJ_WRITE(target_ary, &ptr[idx], item);
+    });
+    ARY_SET_LEN(ary, idx + 1);
+    ary_verify(ary);
     return ary;
 }
 
 VALUE
-rb_ary_pop(ary)
-    VALUE ary;
+rb_ary_cat(VALUE ary, const VALUE *argv, long len)
 {
-    if (RARRAY(ary)->len == 0) return Qnil;
-    if (RARRAY(ary)->len * 10 < RARRAY(ary)->capa && RARRAY(ary)->capa > ARY_DEFAULT_SIZE) {
-	RARRAY(ary)->capa = RARRAY(ary)->len * 2;
-	REALLOC_N(RARRAY(ary)->ptr, VALUE, RARRAY(ary)->capa);
-    }
-    return RARRAY(ary)->ptr[--RARRAY(ary)->len];
+    long oldlen = RARRAY_LEN(ary);
+    VALUE target_ary = ary_ensure_room_for_push(ary, len);
+    ary_memcpy0(ary, oldlen, len, argv, target_ary);
+    ARY_SET_LEN(ary, oldlen + len);
+    return ary;
+}
+
+/*
+ *  call-seq:
+ *    array.push(*objects) -> self
+ *
+ *  Appends trailing elements.
+ *
+ *  Appends each argument in +objects+ to +self+;  returns +self+:
+ *    a = [:foo, 'bar', 2]
+ *    a.push(:baz, :bat) # => [:foo, "bar", 2, :baz, :bat]
+ *
+ *  Appends each argument as one element, even if it is another \Array:
+ *    a = [:foo, 'bar', 2]
+ *    a1 = a.push([:baz, :bat], [:bam, :bad])
+ *    a1 # => [:foo, "bar", 2, [:baz, :bat], [:bam, :bad]]
+ *
+ *  Array#append is an alias for \Array#push.
+ *
+ *  Related: #pop, #shift, #unshift.
+ */
+
+static VALUE
+rb_ary_push_m(int argc, VALUE *argv, VALUE ary)
+{
+    return rb_ary_cat(ary, argv, argc);
 }
 
 VALUE
-rb_ary_shift(ary)
-    VALUE ary;
+rb_ary_pop(VALUE ary)
 {
-    VALUE top;
+    long n;
+    rb_ary_modify_check(ary);
+    n = RARRAY_LEN(ary);
+    if (n == 0) return Qnil;
+    if (ARY_OWNS_HEAP_P(ary) &&
+	n * 3 < ARY_CAPA(ary) &&
+	ARY_CAPA(ary) > ARY_DEFAULT_SIZE)
+    {
+	ary_resize_capa(ary, n * 2);
+    }
+    --n;
+    ARY_SET_LEN(ary, n);
+    ary_verify(ary);
+    return RARRAY_AREF(ary, n);
+}
 
-    if (RARRAY(ary)->len == 0) return Qnil;
+/*
+ *  call-seq:
+ *    array.pop -> object or nil
+ *    array.pop(n) -> new_array
+ *
+ *  Removes and returns trailing elements.
+ *
+ *  When no argument is given and +self+ is not empty,
+ *  removes and returns the last element:
+ *    a = [:foo, 'bar', 2]
+ *    a.pop # => 2
+ *    a # => [:foo, "bar"]
+ *
+ *  Returns +nil+ if the array is empty.
+ *
+ *  When a non-negative \Integer argument +n+ is given and is in range,
+ *  removes and returns the last +n+ elements in a new \Array:
+ *    a = [:foo, 'bar', 2]
+ *    a.pop(2) # => ["bar", 2]
+ *
+ *  If +n+ is positive and out of range,
+ *  removes and returns all elements:
+ *    a = [:foo, 'bar', 2]
+ *    a.pop(50) # => [:foo, "bar", 2]
+ *
+ *  Related: #push, #shift, #unshift.
+ */
 
-    top = RARRAY(ary)->ptr[0];
-    RARRAY(ary)->len--;
+static VALUE
+rb_ary_pop_m(int argc, VALUE *argv, VALUE ary)
+{
+    VALUE result;
 
-    /* sliding items */
-    MEMMOVE(RARRAY(ary)->ptr, RARRAY(ary)->ptr+1, VALUE, RARRAY(ary)->len);
-    if (RARRAY(ary)->len * 10 < RARRAY(ary)->capa && RARRAY(ary)->capa > ARY_DEFAULT_SIZE) {
-	RARRAY(ary)->capa = RARRAY(ary)->len * 2;
-	REALLOC_N(RARRAY(ary)->ptr, VALUE, RARRAY(ary)->capa);
+    if (argc == 0) {
+	return rb_ary_pop(ary);
     }
 
-    return top;
+    rb_ary_modify_check(ary);
+    result = ary_take_first_or_last(argc, argv, ary, ARY_TAKE_LAST);
+    ARY_INCREASE_LEN(ary, -RARRAY_LEN(result));
+    ary_verify(ary);
+    return result;
 }
 
 VALUE
-rb_ary_unshift(ary, item)
-    VALUE ary, item;
+rb_ary_shift(VALUE ary)
 {
-    rb_ary_modify(ary);
-    if (RARRAY(ary)->len >= RARRAY(ary)->capa) {
-	int capa_inc = RARRAY(ary)->capa / 2;
-	if (capa_inc < ARY_DEFAULT_SIZE) {
-	    capa_inc = ARY_DEFAULT_SIZE;
+    VALUE top;
+    long len = RARRAY_LEN(ary);
+
+    rb_ary_modify_check(ary);
+    if (len == 0) return Qnil;
+    top = RARRAY_AREF(ary, 0);
+    if (!ARY_SHARED_P(ary)) {
+	if (len < ARY_DEFAULT_SIZE) {
+            RARRAY_PTR_USE_TRANSIENT(ary, ptr, {
+		MEMMOVE(ptr, ptr+1, VALUE, len-1);
+	    }); /* WB: no new reference */
+            ARY_INCREASE_LEN(ary, -1);
+            ary_verify(ary);
+	    return top;
 	}
-	RARRAY(ary)->capa+=capa_inc;
-	REALLOC_N(RARRAY(ary)->ptr, VALUE, RARRAY(ary)->capa);
+        assert(!ARY_EMBED_P(ary)); /* ARY_EMBED_LEN_MAX < ARY_DEFAULT_SIZE */
+
+	ARY_SET(ary, 0, Qnil);
+	ary_make_shared(ary);
+    }
+    else if (ARY_SHARED_ROOT_OCCUPIED(ARY_SHARED_ROOT(ary))) {
+        RARRAY_PTR_USE_TRANSIENT(ary, ptr, ptr[0] = Qnil);
     }
+    ARY_INCREASE_PTR(ary, 1);		/* shift ptr */
+    ARY_INCREASE_LEN(ary, -1);
 
-    /* sliding items */
-    MEMMOVE(RARRAY(ary)->ptr+1, RARRAY(ary)->ptr, VALUE, RARRAY(ary)->len);
+    ary_verify(ary);
 
-    RARRAY(ary)->len++;
-    RARRAY(ary)->ptr[0] = item;
+    return top;
+}
+
+/*
+ *  call-seq:
+ *     array.shift -> object or nil
+ *     array.shift(n) -> new_array
+ *
+ *  Removes and returns leading elements.
+ *
+ *  When no argument is given, removes and returns the first element:
+ *    a = [:foo, 'bar', 2]
+ *    a.shift # => :foo
+ *    a # => ['bar', 2]
+ *
+ *  Returns +nil+ if +self+ is empty.
+ *
+ *  When positive \Integer argument +n+ is given, removes the first +n+ elements;
+ *  returns those elements in a new \Array:
+ *    a = [:foo, 'bar', 2]
+ *    a.shift(2) # => [:foo, 'bar']
+ *    a # => [2]
+ *
+ *  If +n+ is as large as or larger than <tt>self.length</tt>,
+ *  removes all elements; returns those elements in a new \Array:
+ *    a = [:foo, 'bar', 2]
+ *    a.shift(3) # => [:foo, 'bar', 2]
+ *
+ *  If +n+ is zero, returns a new empty \Array; +self+ is unmodified.
+ *
+ *  Related: #push, #pop, #unshift.
+ */
 
+static VALUE
+rb_ary_shift_m(int argc, VALUE *argv, VALUE ary)
+{
+    VALUE result;
+    long n;
+
+    if (argc == 0) {
+	return rb_ary_shift(ary);
+    }
+
+    rb_ary_modify_check(ary);
+    result = ary_take_first_or_last(argc, argv, ary, ARY_TAKE_FIRST);
+    n = RARRAY_LEN(result);
+    rb_ary_behead(ary,n);
+
+    return result;
+}
+
+static VALUE
+behead_shared(VALUE ary, long n)
+{
+    assert(ARY_SHARED_P(ary));
+    rb_ary_modify_check(ary);
+    if (ARY_SHARED_ROOT_OCCUPIED(ARY_SHARED_ROOT(ary))) {
+        ary_mem_clear(ary, 0, n);
+    }
+    ARY_INCREASE_PTR(ary, n);
+    ARY_INCREASE_LEN(ary, -n);
+    ary_verify(ary);
     return ary;
 }
 
-VALUE
-rb_ary_entry(ary, offset)
-    VALUE ary;
-    int offset;
+static VALUE
+behead_transient(VALUE ary, long n)
 {
-    if (RARRAY(ary)->len == 0) return Qnil;
+    rb_ary_modify_check(ary);
+    RARRAY_PTR_USE_TRANSIENT(ary, ptr, {
+        MEMMOVE(ptr, ptr+n, VALUE, RARRAY_LEN(ary)-n);
+    }); /* WB: no new reference */
+    ARY_INCREASE_LEN(ary, -n);
+    ary_verify(ary);
+    return ary;
+}
 
-    if (offset < 0) {
-	offset = RARRAY(ary)->len + offset;
+MJIT_FUNC_EXPORTED VALUE
+rb_ary_behead(VALUE ary, long n)
+{
+    if (n <= 0) {
+        return ary;
     }
-    if (offset < 0 || RARRAY(ary)->len <= offset) {
-	return Qnil;
+    else if (ARY_SHARED_P(ary)) {
+        return behead_shared(ary, n);
+    }
+    else if (RARRAY_LEN(ary) >= ARY_DEFAULT_SIZE) {
+        ary_make_shared(ary);
+        return behead_shared(ary, n);
+    }
+    else {
+        return behead_transient(ary, n);
     }
-
-    return RARRAY(ary)->ptr[offset];
 }
 
 static VALUE
-rb_ary_subseq(ary, beg, len)
-    VALUE ary;
-    int beg, len;
+make_room_for_unshift(VALUE ary, const VALUE *head, VALUE *sharedp, int argc, long capa, long len)
 {
-    VALUE ary2;
+    if (head - sharedp < argc) {
+        long room = capa - len - argc;
 
-    if (len <= 0) {
-	return rb_ary_new2(0);
+        room -= room >> 4;
+        MEMMOVE((VALUE *)sharedp + argc + room, head, VALUE, len);
+        head = sharedp + argc + room;
     }
-    if (beg < 0) {
-	len += beg;
-	beg = 0;
+    ARY_SET_PTR(ary, head - argc);
+    assert(ARY_SHARED_ROOT_OCCUPIED(ARY_SHARED_ROOT(ary)));
+
+    ary_verify(ary);
+    return ARY_SHARED_ROOT(ary);
+}
+
+static VALUE
+ary_modify_for_unshift(VALUE ary, int argc)
+{
+    long len = RARRAY_LEN(ary);
+    long new_len = len + argc;
+    long capa;
+    const VALUE *head, *sharedp;
+
+    rb_ary_modify(ary);
+    capa = ARY_CAPA(ary);
+    if (capa - (capa >> 6) <= new_len) {
+	ary_double_capa(ary, new_len);
     }
-    if (beg + len > RARRAY(ary)->len) {
-	len = RARRAY(ary)->len - beg;
+
+    /* use shared array for big "queues" */
+    if (new_len > ARY_DEFAULT_SIZE * 4) {
+        ary_verify(ary);
+
+        /* make a room for unshifted items */
+	capa = ARY_CAPA(ary);
+	ary_make_shared(ary);
+
+        head = sharedp = RARRAY_CONST_PTR_TRANSIENT(ary);
+        return make_room_for_unshift(ary, head, (void *)sharedp, argc, capa, len);
     }
-    if (len < 0) {
-	len = 0;
+    else {
+	/* sliding items */
+        RARRAY_PTR_USE_TRANSIENT(ary, ptr, {
+	    MEMMOVE(ptr + argc, ptr, VALUE, len);
+	});
+
+        ary_verify(ary);
+	return ary;
     }
+}
 
-    ary2 = rb_ary_new2(len);
-    MEMCPY(RARRAY(ary2)->ptr, RARRAY(ary)->ptr+beg, VALUE, len);
-    RARRAY(ary2)->len = len;
+static VALUE
+ary_ensure_room_for_unshift(VALUE ary, int argc)
+{
+    long len = RARRAY_LEN(ary);
+    long new_len = len + argc;
 
-    return ary2;
+    if (len > ARY_MAX_SIZE - argc) {
+        rb_raise(rb_eIndexError, "index %ld too big", new_len);
+    }
+    else if (! ARY_SHARED_P(ary)) {
+        return ary_modify_for_unshift(ary, argc);
+    }
+    else {
+        VALUE shared_root = ARY_SHARED_ROOT(ary);
+        long capa = RARRAY_LEN(shared_root);
+
+        if (! ARY_SHARED_ROOT_OCCUPIED(shared_root)) {
+            return ary_modify_for_unshift(ary, argc);
+        }
+        else if (new_len > capa) {
+            return ary_modify_for_unshift(ary, argc);
+        }
+        else {
+            const VALUE * head = RARRAY_CONST_PTR_TRANSIENT(ary);
+            void *sharedp = (void *)RARRAY_CONST_PTR_TRANSIENT(shared_root);
+
+            rb_ary_modify_check(ary);
+            return make_room_for_unshift(ary, head, sharedp, argc, capa, len);
+        }
+    }
 }
 
+/*
+ *  call-seq:
+ *    array.unshift(*objects) -> self
+ *
+ *  Prepends the given +objects+ to +self+:
+ *    a = [:foo, 'bar', 2]
+ *    a.unshift(:bam, :bat) # => [:bam, :bat, :foo, "bar", 2]
+ *
+ *  Array#prepend is an alias for Array#unshift.
+ *
+ *  Related: #push, #pop, #shift.
+ */
+
 static VALUE
-beg_len(range, begp, lenp, len)
-    VALUE range;
-    int *begp, *lenp, len;
+rb_ary_unshift_m(int argc, VALUE *argv, VALUE ary)
+{
+    long len = RARRAY_LEN(ary);
+    VALUE target_ary;
+
+    if (argc == 0) {
+	rb_ary_modify_check(ary);
+	return ary;
+    }
+
+    target_ary = ary_ensure_room_for_unshift(ary, argc);
+    ary_memcpy0(ary, 0, argc, argv, target_ary);
+    ARY_SET_LEN(ary, len + argc);
+    return ary;
+}
+
+VALUE
+rb_ary_unshift(VALUE ary, VALUE item)
+{
+    return rb_ary_unshift_m(1,&item,ary);
+}
+
+/* faster version - use this if you don't need to treat negative offset */
+static inline VALUE
+rb_ary_elt(VALUE ary, long offset)
+{
+    long len = RARRAY_LEN(ary);
+    if (len == 0) return Qnil;
+    if (offset < 0 || len <= offset) {
+	return Qnil;
+    }
+    return RARRAY_AREF(ary, offset);
+}
+
+VALUE
+rb_ary_entry(VALUE ary, long offset)
+{
+    return rb_ary_entry_internal(ary, offset);
+}
+
+VALUE
+rb_ary_subseq_step(VALUE ary, long beg, long len, long step)
+{
+    VALUE klass;
+    long alen = RARRAY_LEN(ary);
+
+    if (beg > alen) return Qnil;
+    if (beg < 0 || len < 0) return Qnil;
+
+    if (alen < len || alen < beg + len) {
+	len = alen - beg;
+    }
+    klass = rb_cArray;
+    if (len == 0) return ary_new(klass, 0);
+    if (step == 0)
+        rb_raise(rb_eArgError, "slice step cannot be zero");
+    if (step == 1)
+        return ary_make_partial(ary, klass, beg, len);
+    else
+        return ary_make_partial_step(ary, klass, beg, len, step);
+}
+
+VALUE
+rb_ary_subseq(VALUE ary, long beg, long len)
 {
-    int beg, end;
-    int b, e;
+    return rb_ary_subseq_step(ary, beg, len, 1);
+}
+
+static VALUE rb_ary_aref2(VALUE ary, VALUE b, VALUE e);
+
+/*
+ *  call-seq:
+ *    array[index] -> object or nil
+ *    array[start, length] -> object or nil
+ *    array[range] -> object or nil
+ *    array[aseq] -> object or nil
+ *    array.slice(index) -> object or nil
+ *    array.slice(start, length) -> object or nil
+ *    array.slice(range) -> object or nil
+ *    array.slice(aseq) -> object or nil
+ *
+ *  Returns elements from +self+; does not modify +self+.
+ *
+ *  When a single \Integer argument +index+ is given, returns the element at offset +index+:
+ *    a = [:foo, 'bar', 2]
+ *    a[0] # => :foo
+ *    a[2] # => 2
+ *    a # => [:foo, "bar", 2]
+ *
+ *  If +index+ is negative, counts relative to the end of +self+:
+ *    a = [:foo, 'bar', 2]
+ *    a[-1] # => 2
+ *    a[-2] # => "bar"
+ *
+ *  If +index+ is out of range, returns +nil+.
+ *
+ *  When two \Integer arguments +start+ and +length+ are given,
+ *  returns a new \Array of size +length+ containing successive elements beginning at offset +start+:
+ *    a = [:foo, 'bar', 2]
+ *    a[0, 2] # => [:foo, "bar"]
+ *    a[1, 2] # => ["bar", 2]
+ *
+ *  If <tt>start + length</tt> is greater than <tt>self.length</tt>,
+ *  returns all elements from offset +start+ to the end:
+ *    a = [:foo, 'bar', 2]
+ *    a[0, 4] # => [:foo, "bar", 2]
+ *    a[1, 3] # => ["bar", 2]
+ *    a[2, 2] # => [2]
+ *
+ *  If <tt>start == self.size</tt> and <tt>length >= 0</tt>,
+ *  returns a new empty \Array.
+ *
+ *  If +length+ is negative, returns +nil+.
+ *
+ *  When a single \Range argument +range+ is given,
+ *  treats <tt>range.min</tt> as +start+ above
+ *  and <tt>range.size</tt> as +length+ above:
+ *    a = [:foo, 'bar', 2]
+ *    a[0..1] # => [:foo, "bar"]
+ *    a[1..2] # => ["bar", 2]
+ *
+ *  Special case: If <tt>range.start == a.size</tt>, returns a new empty \Array.
+ *
+ *  If <tt>range.end</tt> is negative, calculates the end index from the end:
+ *    a = [:foo, 'bar', 2]
+ *    a[0..-1] # => [:foo, "bar", 2]
+ *    a[0..-2] # => [:foo, "bar"]
+ *    a[0..-3] # => [:foo]
+ *
+ *  If <tt>range.start</tt> is negative, calculates the start index from the end:
+ *    a = [:foo, 'bar', 2]
+ *    a[-1..2] # => [2]
+ *    a[-2..2] # => ["bar", 2]
+ *    a[-3..2] # => [:foo, "bar", 2]
+ *
+ *  If <tt>range.start</tt> is larger than the array size, returns +nil+.
+ *    a = [:foo, 'bar', 2]
+ *    a[4..1] # => nil
+ *    a[4..0] # => nil
+ *    a[4..-1] # => nil
+ *
+ *  When a single Enumerator::ArithmeticSequence argument +aseq+ is given,
+ *  returns an Array of elements corresponding to the indexes produced by
+ *  the sequence.
+ *    a = ['--', 'data1', '--', 'data2', '--', 'data3']
+ *    a[(1..).step(2)] # => ["data1", "data2", "data3"]
+ *
+ *  Unlike slicing with range, if the start or the end of the arithmetic sequence
+ *  is larger than array size, throws RangeError.
+ *    a = ['--', 'data1', '--', 'data2', '--', 'data3']
+ *    a[(1..11).step(2)]
+ *    # RangeError (((1..11).step(2)) out of range)
+ *    a[(7..).step(2)]
+ *    # RangeError (((7..).step(2)) out of range)
+ *
+ *  If given a single argument, and its type is not one of the listed, tries to
+ *  convert it to Integer, and raises if it is impossible:
+ *    a = [:foo, 'bar', 2]
+ *    # Raises TypeError (no implicit conversion of Symbol into Integer):
+ *    a[:foo]
+ *
+ *  Array#slice is an alias for Array#[].
+ */
 
-    if (!rb_range_beg_end(range, &beg, &end)) return Qfalse;
-    b = beg; e = end;
+VALUE
+rb_ary_aref(int argc, const VALUE *argv, VALUE ary)
+{
+    rb_check_arity(argc, 1, 2);
+    if (argc == 2) {
+	return rb_ary_aref2(ary, argv[0], argv[1]);
+    }
+    return rb_ary_aref1(ary, argv[0]);
+}
 
+static VALUE
+rb_ary_aref2(VALUE ary, VALUE b, VALUE e)
+{
+    long beg = NUM2LONG(b);
+    long len = NUM2LONG(e);
     if (beg < 0) {
-	beg = len + beg;
+	beg += RARRAY_LEN(ary);
     }
-    if (end < 0) {
-	end = len + end;
+    return rb_ary_subseq(ary, beg, len);
+}
+
+MJIT_FUNC_EXPORTED VALUE
+rb_ary_aref1(VALUE ary, VALUE arg)
+{
+    long beg, len, step;
+
+    /* special case - speeding up */
+    if (FIXNUM_P(arg)) {
+	return rb_ary_entry(ary, FIX2LONG(arg));
     }
-    if (beg > end) {
-	rb_raise(rb_eIndexError, "end smaller than beg [%d..%d]", b, e);
+    /* check if idx is Range or ArithmeticSequence */
+    switch (rb_arithmetic_sequence_beg_len_step(arg, &beg, &len, &step, RARRAY_LEN(ary), 0)) {
+      case Qfalse:
+        break;
+      case Qnil:
+        return Qnil;
+      default:
+        return rb_ary_subseq_step(ary, beg, len, step);
     }
 
-    *begp = beg;
-    if (beg > len) {
-	*lenp = 0;
+    return rb_ary_entry(ary, NUM2LONG(arg));
+}
+
+/*
+ *  call-seq:
+ *    array.at(index) -> object
+ *
+ *  Returns the element at \Integer offset +index+; does not modify +self+.
+ *    a = [:foo, 'bar', 2]
+ *    a.at(0) # => :foo
+ *    a.at(2) # => 2
+ */
+
+VALUE
+rb_ary_at(VALUE ary, VALUE pos)
+{
+    return rb_ary_entry(ary, NUM2LONG(pos));
+}
+
+/*
+ *  call-seq:
+ *    array.first -> object or nil
+ *    array.first(n) -> new_array
+ *
+ *  Returns elements from +self+; does not modify +self+.
+ *
+ *  When no argument is given, returns the first element:
+ *    a = [:foo, 'bar', 2]
+ *    a.first # => :foo
+ *    a # => [:foo, "bar", 2]
+ *
+ *  If +self+ is empty, returns +nil+.
+ *
+ *  When non-negative \Integer argument +n+ is given,
+ *  returns the first +n+ elements in a new \Array:
+ *    a = [:foo, 'bar', 2]
+ *    a.first(2) # => [:foo, "bar"]
+ *
+ *  If <tt>n >= array.size</tt>, returns all elements:
+ *    a = [:foo, 'bar', 2]
+ *    a.first(50) # => [:foo, "bar", 2]
+ *
+ *  If <tt>n == 0</tt> returns an new empty \Array:
+ *    a = [:foo, 'bar', 2]
+ *    a.first(0) # []
+ *
+ *  Related: #last.
+ */
+static VALUE
+rb_ary_first(int argc, VALUE *argv, VALUE ary)
+{
+    if (argc == 0) {
+	if (RARRAY_LEN(ary) == 0) return Qnil;
+	return RARRAY_AREF(ary, 0);
     }
     else {
-	len = end - beg +1;
-	*lenp = len;
+	return ary_take_first_or_last(argc, argv, ary, ARY_TAKE_FIRST);
     }
-    return Qtrue;
 }
 
+/*
+ *  call-seq:
+ *    array.last  -> object or nil
+ *    array.last(n) -> new_array
+ *
+ *  Returns elements from +self+; +self+ is not modified.
+ *
+ *  When no argument is given, returns the last element:
+ *    a = [:foo, 'bar', 2]
+ *    a.last # => 2
+ *    a # => [:foo, "bar", 2]
+ *
+ *  If +self+ is empty, returns +nil+.
+ *
+ *  When non-negative \Innteger argument +n+ is given,
+ *  returns the last +n+ elements in a new \Array:
+ *    a = [:foo, 'bar', 2]
+ *    a.last(2) # => ["bar", 2]
+ *
+ *  If <tt>n >= array.size</tt>, returns all elements:
+ *    a = [:foo, 'bar', 2]
+ *    a.last(50) # => [:foo, "bar", 2]
+ *
+ *  If <tt>n == 0</tt>, returns an new empty \Array:
+ *    a = [:foo, 'bar', 2]
+ *    a.last(0) # []
+ *
+ *  Related: #first.
+ */
+
 VALUE
-rb_ary_aref(argc, argv, ary)
-    int argc;
-    VALUE *argv;
-    VALUE ary;
+rb_ary_last(int argc, const VALUE *argv, VALUE ary)
 {
-    VALUE arg1, arg2;
-    int beg, len;
-
-    if (rb_scan_args(argc, argv, "11", &arg1, &arg2) == 2) {
-	beg = NUM2INT(arg1);
-	len = NUM2INT(arg2);
-	if (beg < 0) {
-	    beg = RARRAY(ary)->len + beg;
-	}
-	return rb_ary_subseq(ary, beg, len);
+    if (argc == 0) {
+	long len = RARRAY_LEN(ary);
+	if (len == 0) return Qnil;
+	return RARRAY_AREF(ary, len-1);
     }
+    else {
+	return ary_take_first_or_last(argc, argv, ary, ARY_TAKE_LAST);
+    }
+}
 
-    /* special case - speeding up */
-    if (FIXNUM_P(arg1)) {
-	return rb_ary_entry(ary, FIX2INT(arg1));
+/*
+ *  call-seq:
+ *    array.fetch(index) -> element
+ *    array.fetch(index, default_value) -> element
+ *    array.fetch(index) {|index| ... } -> element
+ *
+ *  Returns the element at offset  +index+.
+ *
+ *  With the single \Integer argument +index+,
+ *  returns the element at offset +index+:
+ *    a = [:foo, 'bar', 2]
+ *    a.fetch(1) # => "bar"
+ *
+ *  If +index+ is negative, counts from the end of the array:
+ *    a = [:foo, 'bar', 2]
+ *    a.fetch(-1) # => 2
+ *    a.fetch(-2) # => "bar"
+ *
+ *  With arguments +index+ and +default_value+,
+ *  returns the element at offset +index+ if index is in range,
+ *  otherwise returns +default_value+:
+ *    a = [:foo, 'bar', 2]
+ *    a.fetch(1, nil) # => "bar"
+ *
+ *  With argument +index+ and a block,
+ *  returns the element at offset +index+ if index is in range
+ *  (and the block is not called); otherwise calls the block with index and returns its return value:
+ *
+ *    a = [:foo, 'bar', 2]
+ *    a.fetch(1) {|index| raise 'Cannot happen' } # => "bar"
+ *    a.fetch(50) {|index| "Value for #{index}" } # => "Value for 50"
+ */
+
+static VALUE
+rb_ary_fetch(int argc, VALUE *argv, VALUE ary)
+{
+    VALUE pos, ifnone;
+    long block_given;
+    long idx;
+
+    rb_scan_args(argc, argv, "11", &pos, &ifnone);
+    block_given = rb_block_given_p();
+    if (block_given && argc == 2) {
+	rb_warn("block supersedes default value argument");
     }
-    else if (TYPE(arg1) == T_BIGNUM) {
-	rb_raise(rb_eIndexError, "index too big");
+    idx = NUM2LONG(pos);
+
+    if (idx < 0) {
+	idx +=  RARRAY_LEN(ary);
     }
-    else if (beg_len(arg1, &beg, &len, RARRAY(ary)->len)) {
-	/* check if idx is Range */
-	return rb_ary_subseq(ary, beg, len);
+    if (idx < 0 || RARRAY_LEN(ary) <= idx) {
+	if (block_given) return rb_yield(pos);
+	if (argc == 1) {
+	    rb_raise(rb_eIndexError, "index %ld outside of array bounds: %ld...%ld",
+			idx - (idx < 0 ? RARRAY_LEN(ary) : 0), -RARRAY_LEN(ary), RARRAY_LEN(ary));
+	}
+	return ifnone;
     }
-    return rb_ary_entry(ary, NUM2INT(arg1));
+    return RARRAY_AREF(ary, idx);
 }
 
+/*
+ *  call-seq:
+ *    array.index(object) -> integer or nil
+ *    array.index {|element| ... } -> integer or nil
+ *    array.index -> new_enumerator
+ *
+ *  Returns the index of a specified element.
+ *
+ *  When argument +object+ is given but no block,
+ *  returns the index of the first element +element+
+ *  for which <tt>object == element</tt>:
+ *    a = [:foo, 'bar', 2, 'bar']
+ *    a.index('bar') # => 1
+ *
+ *  Returns +nil+ if no such element found.
+ *
+ *  When both argument +object+ and a block are given,
+ *  calls the block with each successive element;
+ *  returns the index of the first element for which the block returns a truthy value:
+ *    a = [:foo, 'bar', 2, 'bar']
+ *    a.index {|element| element == 'bar' } # => 1
+ *
+ *  Returns +nil+ if the block never returns a truthy value.
+ *
+ *  When neither an argument nor a block is given, returns a new Enumerator:
+ *    a = [:foo, 'bar', 2]
+ *    e = a.index
+ *    e # => #<Enumerator: [:foo, "bar", 2]:index>
+ *    e.each {|element| element == 'bar' } # => 1
+ *
+ *  Array#find_index is an alias for Array#index.
+ *
+ *  Related: #rindex.
+ */
+
 static VALUE
-rb_ary_index(ary, val)
-    VALUE ary;
-    VALUE val;
+rb_ary_index(int argc, VALUE *argv, VALUE ary)
 {
-    int i;
+    VALUE val;
+    long i;
 
-    for (i=0; i<RARRAY(ary)->len; i++) {
-	if (rb_equal(RARRAY(ary)->ptr[i], val))
-	    return INT2FIX(i);
+    if (argc == 0) {
+	RETURN_ENUMERATOR(ary, 0, 0);
+	for (i=0; i<RARRAY_LEN(ary); i++) {
+	    if (RTEST(rb_yield(RARRAY_AREF(ary, i)))) {
+		return LONG2NUM(i);
+	    }
+	}
+	return Qnil;
+    }
+    rb_check_arity(argc, 0, 1);
+    val = argv[0];
+    if (rb_block_given_p())
+	rb_warn("given block not used");
+    for (i=0; i<RARRAY_LEN(ary); i++) {
+	VALUE e = RARRAY_AREF(ary, i);
+	if (rb_equal(e, val)) {
+	    return LONG2NUM(i);
+	}
     }
     return Qnil;
 }
 
+/*
+ *  call-seq:
+ *    array.rindex(object) -> integer or nil
+ *    array.rindex {|element| ... } -> integer or nil
+ *    array.rindex -> new_enumerator
+ *
+ *  Returns the index of the last element for which <tt>object == element</tt>.
+ *
+ *  When argument +object+ is given but no block, returns the index of the last such element found:
+ *    a = [:foo, 'bar', 2, 'bar']
+ *    a.rindex('bar') # => 3
+ *
+ *  Returns +nil+ if no such object found.
+ *
+ *  When a block is given but no argument, calls the block with each successive element;
+ *  returns the index of the last element for which the block returns a truthy value:
+ *    a = [:foo, 'bar', 2, 'bar']
+ *    a.rindex {|element| element == 'bar' } # => 3
+ *
+ *  Returns +nil+ if the block never returns a truthy value.
+ *
+ *  When neither an argument nor a block is given, returns a new \Enumerator:
+ *
+ *    a = [:foo, 'bar', 2, 'bar']
+ *    e = a.rindex
+ *    e # => #<Enumerator: [:foo, "bar", 2, "bar"]:rindex>
+ *    e.each {|element| element == 'bar' } # => 3
+ *
+ *  Related: #index.
+ */
+
 static VALUE
-rb_ary_rindex(ary, val)
-    VALUE ary;
-    VALUE val;
+rb_ary_rindex(int argc, VALUE *argv, VALUE ary)
 {
-    int i = RARRAY(ary)->len;
+    VALUE val;
+    long i = RARRAY_LEN(ary), len;
 
+    if (argc == 0) {
+	RETURN_ENUMERATOR(ary, 0, 0);
+	while (i--) {
+	    if (RTEST(rb_yield(RARRAY_AREF(ary, i))))
+		return LONG2NUM(i);
+	    if (i > (len = RARRAY_LEN(ary))) {
+		i = len;
+	    }
+	}
+	return Qnil;
+    }
+    rb_check_arity(argc, 0, 1);
+    val = argv[0];
+    if (rb_block_given_p())
+	rb_warn("given block not used");
     while (i--) {
-	if (rb_equal(RARRAY(ary)->ptr[i], val))
-	    return INT2FIX(i);
+	VALUE e = RARRAY_AREF(ary, i);
+	if (rb_equal(e, val)) {
+	    return LONG2NUM(i);
+	}
+        if (i > RARRAY_LEN(ary)) {
+            break;
+        }
     }
     return Qnil;
 }
 
-static VALUE
-rb_ary_indexes(argc, argv, ary)
-    int argc;
-    VALUE *argv;
-    VALUE ary;
+VALUE
+rb_ary_to_ary(VALUE obj)
 {
-    VALUE new_ary;
-    int i;
+    VALUE tmp = rb_check_array_type(obj);
 
-    new_ary = rb_ary_new2(argc);
-    for (i=0; i<argc; i++) {
-	rb_ary_store(new_ary, i, rb_ary_entry(ary, NUM2INT(argv[i])));
-    }
-
-    return new_ary;
+    if (!NIL_P(tmp)) return tmp;
+    return rb_ary_new3(1, obj);
 }
 
 static void
-rb_ary_replace(ary, beg, len, rpl)
-    VALUE ary, rpl;
-    int beg, len;
+rb_ary_splice(VALUE ary, long beg, long len, const VALUE *rptr, long rlen)
 {
-    if (len < 0) {
-	rb_raise(rb_eIndexError, "negative length %d", len);
-    }
+    long olen;
+    long rofs;
 
-    if (TYPE(rpl) != T_ARRAY) {
-	rpl = rb_Array(rpl);
+    if (len < 0) rb_raise(rb_eIndexError, "negative length (%ld)", len);
+    olen = RARRAY_LEN(ary);
+    if (beg < 0) {
+	beg += olen;
+	if (beg < 0) {
+	    rb_raise(rb_eIndexError, "index %ld too small for array; minimum: %ld",
+		     beg - olen, -olen);
+	}
     }
-
-    if (beg + len < 0 || (beg < 0 && beg <= -len)) {
-	rb_raise(rb_eIndexError, "index %d out of range", beg);
+    if (olen < len || olen < beg + len) {
+	len = olen - beg;
     }
-    if (beg < 0) {
-	len += beg;
-	beg = 0;
+
+    {
+        const VALUE *optr = RARRAY_CONST_PTR_TRANSIENT(ary);
+	rofs = (rptr >= optr && rptr < optr + olen) ? rptr - optr : -1;
     }
 
-    rb_ary_modify(ary);
-    if (beg >= RARRAY(ary)->len) {
-	len = beg + RARRAY(rpl)->len;
-	if (len >= RARRAY(ary)->capa) {
-	    RARRAY(ary)->capa=len;
-	    REALLOC_N(RARRAY(ary)->ptr, VALUE, RARRAY(ary)->capa);
+    if (beg >= olen) {
+	VALUE target_ary;
+	if (beg > ARY_MAX_SIZE - rlen) {
+	    rb_raise(rb_eIndexError, "index %ld too big", beg);
 	}
-	rb_mem_clear(RARRAY(ary)->ptr+RARRAY(ary)->len, beg-RARRAY(ary)->len);
-	MEMCPY(RARRAY(ary)->ptr+beg, RARRAY(rpl)->ptr, VALUE, RARRAY(rpl)->len);
-	RARRAY(ary)->len = len;
+	target_ary = ary_ensure_room_for_push(ary, rlen-len); /* len is 0 or negative */
+	len = beg + rlen;
+	ary_mem_clear(ary, olen, beg - olen);
+	if (rlen > 0) {
+            if (rofs != -1) rptr = RARRAY_CONST_PTR_TRANSIENT(ary) + rofs;
+	    ary_memcpy0(ary, beg, rlen, rptr, target_ary);
+	}
+	ARY_SET_LEN(ary, len);
     }
     else {
-	int alen;
+	long alen;
 
-	if (beg + len > RARRAY(ary)->len) {
-	    len = RARRAY(ary)->len - beg;
+	if (olen - len > ARY_MAX_SIZE - rlen) {
+	    rb_raise(rb_eIndexError, "index %ld too big", olen + rlen - len);
+	}
+	rb_ary_modify(ary);
+	alen = olen + rlen - len;
+	if (alen >= ARY_CAPA(ary)) {
+	    ary_double_capa(ary, alen);
 	}
 
-	alen = RARRAY(ary)->len + RARRAY(rpl)->len - len;
-	if (alen >= RARRAY(ary)->capa) {
-	    RARRAY(ary)->capa=alen;
-	    REALLOC_N(RARRAY(ary)->ptr, VALUE, RARRAY(ary)->capa);
+	if (len != rlen) {
+            RARRAY_PTR_USE_TRANSIENT(ary, ptr,
+                                     MEMMOVE(ptr + beg + rlen, ptr + beg + len,
+                                             VALUE, olen - (beg + len)));
+	    ARY_SET_LEN(ary, alen);
 	}
+	if (rlen > 0) {
+            if (rofs != -1) rptr = RARRAY_CONST_PTR_TRANSIENT(ary) + rofs;
+            /* give up wb-protected ary */
+            RB_OBJ_WB_UNPROTECT_FOR(ARRAY, ary);
+
+            /* do not use RARRAY_PTR() because it can causes GC.
+             * ary can contain T_NONE object because it is not cleared.
+             */
+            RARRAY_PTR_USE_TRANSIENT(ary, ptr,
+                                     MEMMOVE(ptr + beg, rptr, VALUE, rlen));
+	}
+    }
+}
+
+void
+rb_ary_set_len(VALUE ary, long len)
+{
+    long capa;
+
+    rb_ary_modify_check(ary);
+    if (ARY_SHARED_P(ary)) {
+	rb_raise(rb_eRuntimeError, "can't set length of shared ");
+    }
+    if (len > (capa = (long)ARY_CAPA(ary))) {
+	rb_bug("probable buffer overflow: %ld for %ld", len, capa);
+    }
+    ARY_SET_LEN(ary, len);
+}
+
+/*!
+ * expands or shrinks \a ary to \a len elements.
+ * expanded region will be filled with Qnil.
+ * \param ary  an array
+ * \param len  new size
+ * \return     \a ary
+ * \post       the size of \a ary is \a len.
+ */
+VALUE
+rb_ary_resize(VALUE ary, long len)
+{
+    long olen;
 
-	if (len != RARRAY(rpl)->len) {
-	    MEMMOVE(RARRAY(ary)->ptr+beg+RARRAY(rpl)->len, RARRAY(ary)->ptr+beg+len,
-		    VALUE, RARRAY(ary)->len-(beg+len));
-	    RARRAY(ary)->len = alen;
+    rb_ary_modify(ary);
+    olen = RARRAY_LEN(ary);
+    if (len == olen) return ary;
+    if (len > ARY_MAX_SIZE) {
+	rb_raise(rb_eIndexError, "index %ld too big", len);
+    }
+    if (len > olen) {
+	if (len >= ARY_CAPA(ary)) {
+	    ary_double_capa(ary, len);
 	}
-	MEMCPY(RARRAY(ary)->ptr+beg, RARRAY(rpl)->ptr, VALUE, RARRAY(rpl)->len);
+	ary_mem_clear(ary, olen, len - olen);
+	ARY_SET_LEN(ary, len);
+    }
+    else if (ARY_EMBED_P(ary)) {
+        ARY_SET_EMBED_LEN(ary, len);
     }
+    else if (len <= RARRAY_EMBED_LEN_MAX) {
+	VALUE tmp[RARRAY_EMBED_LEN_MAX];
+	MEMCPY(tmp, ARY_HEAP_PTR(ary), VALUE, len);
+	ary_discard(ary);
+	MEMCPY((VALUE *)ARY_EMBED_PTR(ary), tmp, VALUE, len); /* WB: no new reference */
+        ARY_SET_EMBED_LEN(ary, len);
+    }
+    else {
+	if (olen > len + ARY_DEFAULT_SIZE) {
+            ary_heap_realloc(ary, len);
+	    ARY_SET_CAPA(ary, len);
+	}
+	ARY_SET_HEAP_LEN(ary, len);
+    }
+    ary_verify(ary);
+    return ary;
 }
 
 static VALUE
-rb_ary_aset(argc, argv, ary)
-    int argc;
-    VALUE *argv;
-    VALUE ary;
+ary_aset_by_rb_ary_store(VALUE ary, long key, VALUE val)
 {
-    VALUE arg1, arg2, arg3;
-    int offset, beg, len;
+    rb_ary_store(ary, key, val);
+    return val;
+}
 
-    if (rb_scan_args(argc, argv, "21", &arg1, &arg2, &arg3) == 3) {
-	beg = NUM2INT(arg1);
-	len = NUM2INT(arg2);
+static VALUE
+ary_aset_by_rb_ary_splice(VALUE ary, long beg, long len, VALUE val)
+{
+    VALUE rpl = rb_ary_to_ary(val);
+    rb_ary_splice(ary, beg, len, RARRAY_CONST_PTR_TRANSIENT(rpl), RARRAY_LEN(rpl));
+    RB_GC_GUARD(rpl);
+    return val;
+}
 
-	if (beg < 0) {
-	    beg = RARRAY(ary)->len + beg;
-	}
-	rb_ary_replace(ary, beg, len, arg3);
-	return arg3;
+/*
+ *  call-seq:
+ *    array[index] = object -> object
+ *    array[start, length] = object -> object
+ *    array[range] = object -> object
+ *
+ *  Assigns elements in +self+; returns the given +object+.
+ *
+ *  When \Integer argument +index+ is given, assigns +object+ to an element in +self+.
+ *
+ *  If +index+ is non-negative, assigns +object+ the element at offset +index+:
+ *    a = [:foo, 'bar', 2]
+ *    a[0] = 'foo' # => "foo"
+ *    a # => ["foo", "bar", 2]
+ *
+ *  If +index+ is greater than <tt>self.length</tt>, extends the array:
+ *    a = [:foo, 'bar', 2]
+ *    a[7] = 'foo' # => "foo"
+ *    a # => [:foo, "bar", 2, nil, nil, nil, nil, "foo"]
+ *
+ *  If +index+ is negative, counts backwards from the end of the array:
+ *    a = [:foo, 'bar', 2]
+ *    a[-1] = 'two' # => "two"
+ *    a # => [:foo, "bar", "two"]
+ *
+ *  When \Integer arguments +start+ and +length+ are given and +object+ is not an \Array,
+ *  removes <tt>length - 1</tt> elements beginning at offset +start+,
+ *  and assigns +object+ at offset +start+:
+ *    a = [:foo, 'bar', 2]
+ *    a[0, 2] = 'foo' # => "foo"
+ *    a # => ["foo", 2]
+ *
+ *  If +start+ is negative, counts backwards from the end of the array:
+ *    a = [:foo, 'bar', 2]
+ *    a[-2, 2] = 'foo' # => "foo"
+ *    a # => [:foo, "foo"]
+ *
+ *  If +start+ is non-negative and outside the array (<tt> >= self.size</tt>),
+ *  extends the array with +nil+, assigns +object+ at offset +start+,
+ *  and ignores +length+:
+ *    a = [:foo, 'bar', 2]
+ *    a[6, 50] = 'foo' # => "foo"
+ *    a # => [:foo, "bar", 2, nil, nil, nil, "foo"]
+ *
+ *  If +length+ is zero, shifts elements at and following offset +start+
+ *  and assigns +object+ at offset +start+:
+ *    a = [:foo, 'bar', 2]
+ *    a[1, 0] = 'foo' # => "foo"
+ *    a # => [:foo, "foo", "bar", 2]
+ *
+ *  If +length+ is too large for the existing array, does not extend the array:
+ *    a = [:foo, 'bar', 2]
+ *    a[1, 5] = 'foo' # => "foo"
+ *    a # => [:foo, "foo"]
+ *
+ *  When \Range argument +range+ is given and +object+ is an \Array,
+ *  removes <tt>length - 1</tt> elements beginning at offset +start+,
+ *  and assigns +object+ at offset +start+:
+ *    a = [:foo, 'bar', 2]
+ *    a[0..1] = 'foo' # => "foo"
+ *    a # => ["foo", 2]
+ *
+ *  if <tt>range.begin</tt> is negative, counts backwards from the end of the array:
+ *    a = [:foo, 'bar', 2]
+ *    a[-2..2] = 'foo' # => "foo"
+ *    a # => [:foo, "foo"]
+ *
+ *  If the array length is less than <tt>range.begin</tt>,
+ *  assigns +object+ at offset <tt>range.begin</tt>, and ignores +length+:
+ *    a = [:foo, 'bar', 2]
+ *    a[6..50] = 'foo' # => "foo"
+ *    a # => [:foo, "bar", 2, nil, nil, nil, "foo"]
+ *
+ *  If <tt>range.end</tt> is zero, shifts elements at and following offset +start+
+ *  and assigns +object+ at offset +start+:
+ *    a = [:foo, 'bar', 2]
+ *    a[1..0] = 'foo' # => "foo"
+ *    a # => [:foo, "foo", "bar", 2]
+ *
+ *  If <tt>range.end</tt> is negative, assigns +object+ at offset +start+,
+ *  retains <tt>range.end.abs -1</tt> elements past that, and removes those beyond:
+ *    a = [:foo, 'bar', 2]
+ *    a[1..-1] = 'foo' # => "foo"
+ *    a # => [:foo, "foo"]
+ *    a = [:foo, 'bar', 2]
+ *    a[1..-2] = 'foo' # => "foo"
+ *    a # => [:foo, "foo", 2]
+ *    a = [:foo, 'bar', 2]
+ *    a[1..-3] = 'foo' # => "foo"
+ *    a # => [:foo, "foo", "bar", 2]
+ *    a = [:foo, 'bar', 2]
+ *
+ *  If <tt>range.end</tt> is too large for the existing array,
+ *  replaces array elements, but does not extend the array with +nil+ values:
+ *    a = [:foo, 'bar', 2]
+ *    a[1..5] = 'foo' # => "foo"
+ *    a # => [:foo, "foo"]
+ */
+
+static VALUE
+rb_ary_aset(int argc, VALUE *argv, VALUE ary)
+{
+    long offset, beg, len;
+
+    rb_check_arity(argc, 2, 3);
+    rb_ary_modify_check(ary);
+    if (argc == 3) {
+	beg = NUM2LONG(argv[0]);
+	len = NUM2LONG(argv[1]);
+        return ary_aset_by_rb_ary_splice(ary, beg, len, argv[2]);
     }
-    else if (FIXNUM_P(arg1)) {
-	offset = FIX2INT(arg1);
-	goto fixnum;
+    if (FIXNUM_P(argv[0])) {
+	offset = FIX2LONG(argv[0]);
+        return ary_aset_by_rb_ary_store(ary, offset, argv[1]);
     }
-    else if (beg_len(arg1, &beg, &len, RARRAY(ary)->len)) {
+    if (rb_range_beg_len(argv[0], &beg, &len, RARRAY_LEN(ary), 1)) {
 	/* check if idx is Range */
-	rb_ary_replace(ary, beg, len, arg2);
-	return arg2;
+        return ary_aset_by_rb_ary_splice(ary, beg, len, argv[1]);
     }
-    if (TYPE(arg1) == T_BIGNUM) {
-	rb_raise(rb_eIndexError, "index too big");
+
+    offset = NUM2LONG(argv[0]);
+    return ary_aset_by_rb_ary_store(ary, offset, argv[1]);
+}
+
+/*
+ *  call-seq:
+ *    array.insert(index, *objects) -> self
+ *
+ *  Inserts given +objects+ before or after the element at \Integer index +offset+;
+ *  returns +self+.
+ *
+ *  When +index+ is non-negative, inserts all given +objects+
+ *  before the element at offset +index+:
+ *    a = [:foo, 'bar', 2]
+ *    a.insert(1, :bat, :bam) # => [:foo, :bat, :bam, "bar", 2]
+ *
+ *  Extends the array if +index+ is beyond the array (<tt>index >= self.size</tt>):
+ *    a = [:foo, 'bar', 2]
+ *    a.insert(5, :bat, :bam)
+ *    a # => [:foo, "bar", 2, nil, nil, :bat, :bam]
+ *
+ *  Does nothing if no objects given:
+ *    a = [:foo, 'bar', 2]
+ *    a.insert(1)
+ *    a.insert(50)
+ *    a.insert(-50)
+ *    a # => [:foo, "bar", 2]
+ *
+ *  When +index+ is negative, inserts all given +objects+
+ *  _after_ the element at offset <tt>index+self.size</tt>:
+ *    a = [:foo, 'bar', 2]
+ *    a.insert(-2, :bat, :bam)
+ *    a # => [:foo, "bar", :bat, :bam, 2]
+ */
+
+static VALUE
+rb_ary_insert(int argc, VALUE *argv, VALUE ary)
+{
+    long pos;
+
+    rb_check_arity(argc, 1, UNLIMITED_ARGUMENTS);
+    rb_ary_modify_check(ary);
+    pos = NUM2LONG(argv[0]);
+    if (argc == 1) return ary;
+    if (pos == -1) {
+	pos = RARRAY_LEN(ary);
+    }
+    else if (pos < 0) {
+	long minpos = -RARRAY_LEN(ary) - 1;
+	if (pos < minpos) {
+	    rb_raise(rb_eIndexError, "index %ld too small for array; minimum: %ld",
+		     pos, minpos);
+	}
+	pos++;
     }
+    rb_ary_splice(ary, pos, 0, argv + 1, argc - 1);
+    return ary;
+}
+
+static VALUE
+rb_ary_length(VALUE ary);
 
-    offset = NUM2INT(arg1);
-  fixnum:
-    rb_ary_store(ary, offset, arg2);
-    return arg2;
+static VALUE
+ary_enum_length(VALUE ary, VALUE args, VALUE eobj)
+{
+    return rb_ary_length(ary);
 }
 
+/*
+ *  call-seq:
+ *    array.each {|element| ... } -> self
+ *    array.each -> Enumerator
+ *
+ *  Iterates over array elements.
+ *
+ *  When a block given, passes each successive array element to the block;
+ *  returns +self+:
+ *    a = [:foo, 'bar', 2]
+ *    a.each {|element|  puts "#{element.class} #{element}" }
+ *
+ *  Output:
+ *    Symbol foo
+ *    String bar
+ *    Integer 2
+ *
+ *  Allows the array to be modified during iteration:
+ *    a = [:foo, 'bar', 2]
+ *    a.each {|element| puts element; a.clear if element.to_s.start_with?('b') }
+ *
+ *  Output:
+ *    foo
+ *    bar
+ *
+ *  When no block given, returns a new \Enumerator:
+ *    a = [:foo, 'bar', 2]
+ *    e = a.each
+ *    e # => #<Enumerator: [:foo, "bar", 2]:each>
+ *    a1 = e.each {|element|  puts "#{element.class} #{element}" }
+ *
+ *  Output:
+ *    Symbol foo
+ *    String bar
+ *    Integer 2
+ *
+ *  Related: #each_index, #reverse_each.
+ */
+
 VALUE
-rb_ary_each(ary)
-    VALUE ary;
+rb_ary_each(VALUE ary)
 {
-    int i;
-
-    for (i=0; i<RARRAY(ary)->len; i++) {
-	rb_yield(RARRAY(ary)->ptr[i]);
+    long i;
+    ary_verify(ary);
+    RETURN_SIZED_ENUMERATOR(ary, 0, 0, ary_enum_length);
+    for (i=0; i<RARRAY_LEN(ary); i++) {
+	rb_yield(RARRAY_AREF(ary, i));
     }
-    return Qnil;
+    return ary;
 }
 
+/*
+ *  call-seq:
+ *    array.each_index {|index| ... } -> self
+ *    array.each_index -> Enumerator
+ *
+ *  Iterates over array indexes.
+ *
+ *  When a block given, passes each successive array index to the block;
+ *  returns +self+:
+ *    a = [:foo, 'bar', 2]
+ *    a.each_index {|index|  puts "#{index} #{a[index]}" }
+ *
+ *  Output:
+ *    0 foo
+ *    1 bar
+ *    2 2
+ *
+ *  Allows the array to be modified during iteration:
+ *    a = [:foo, 'bar', 2]
+ *    a.each_index {|index| puts index; a.clear if index > 0 }
+ *
+ *  Output:
+ *    0
+ *    1
+ *
+ *  When no block given, returns a new \Enumerator:
+ *    a = [:foo, 'bar', 2]
+ *    e = a.each_index
+ *    e # => #<Enumerator: [:foo, "bar", 2]:each_index>
+ *    a1 = e.each {|index|  puts "#{index} #{a[index]}"}
+ *
+ *  Output:
+ *    0 foo
+ *    1 bar
+ *    2 2
+ *
+ *  Related: #each, #reverse_each.
+ */
+
 static VALUE
-rb_ary_each_index(ary)
-    VALUE ary;
+rb_ary_each_index(VALUE ary)
 {
-    int i;
+    long i;
+    RETURN_SIZED_ENUMERATOR(ary, 0, 0, ary_enum_length);
 
-    for (i=0; i<RARRAY(ary)->len; i++) {
-	rb_yield(INT2FIX(i));
+    for (i=0; i<RARRAY_LEN(ary); i++) {
+	rb_yield(LONG2NUM(i));
     }
-    return Qnil;
+    return ary;
 }
 
+/*
+ *  call-seq:
+ *    array.reverse_each {|element| ... } -> self
+ *    array.reverse_each -> Enumerator
+ *
+ *  Iterates backwards over array elements.
+ *
+ *  When a block given, passes, in reverse order, each element to the block;
+ *  returns +self+:
+ *    a = [:foo, 'bar', 2]
+ *    a.reverse_each {|element|  puts "#{element.class} #{element}" }
+ *
+ *  Output:
+ *    Integer 2
+ *    String bar
+ *    Symbol foo
+ *
+ *  Allows the array to be modified during iteration:
+ *    a = [:foo, 'bar', 2]
+ *    a.reverse_each {|element| puts element; a.clear if element.to_s.start_with?('b') }
+ *
+ *  Output:
+ *    2
+ *    bar
+ *
+ *  When no block given, returns a new \Enumerator:
+ *    a = [:foo, 'bar', 2]
+ *    e = a.reverse_each
+ *    e # => #<Enumerator: [:foo, "bar", 2]:reverse_each>
+ *    a1 = e.each {|element|  puts "#{element.class} #{element}" }
+ *  Output:
+ *    Integer 2
+ *    String bar
+ *    Symbol foo
+ *
+ *  Related: #each, #each_index.
+ */
+
 static VALUE
-rb_ary_reverse_each(ary)
-    VALUE ary;
+rb_ary_reverse_each(VALUE ary)
 {
-    int len = RARRAY(ary)->len;
+    long len;
 
+    RETURN_SIZED_ENUMERATOR(ary, 0, 0, ary_enum_length);
+    len = RARRAY_LEN(ary);
     while (len--) {
-	rb_yield(RARRAY(ary)->ptr[len]);
+	long nlen;
+	rb_yield(RARRAY_AREF(ary, len));
+	nlen = RARRAY_LEN(ary);
+	if (nlen < len) {
+	    len = nlen;
+	}
     }
-    return Qnil;
+    return ary;
 }
 
+/*
+ *  call-seq:
+ *    array.length -> an_integer
+ *
+ *  Returns the count of elements in +self+.
+ */
+
 static VALUE
-rb_ary_length(ary)
-    VALUE ary;
+rb_ary_length(VALUE ary)
 {
-    return INT2FIX(RARRAY(ary)->len);
+    long len = RARRAY_LEN(ary);
+    return LONG2NUM(len);
 }
 
+/*
+ *  call-seq:
+ *    array.empty?  -> true or false
+ *
+ *  Returns +true+ if the count of elements in +self+ is zero,
+ *  +false+ otherwise.
+ */
+
 static VALUE
-rb_ary_empty_p(ary)
-    VALUE ary;
+rb_ary_empty_p(VALUE ary)
 {
-    if (RARRAY(ary)->len == 0)
+    if (RARRAY_LEN(ary) == 0)
 	return Qtrue;
     return Qfalse;
 }
 
-static VALUE
-rb_ary_clone(ary)
-    VALUE ary;
+VALUE
+rb_ary_dup(VALUE ary)
 {
-    VALUE ary2 = rb_ary_new2(RARRAY(ary)->len);
+    long len = RARRAY_LEN(ary);
+    VALUE dup = rb_ary_new2(len);
+    ary_memcpy(dup, 0, len, RARRAY_CONST_PTR_TRANSIENT(ary));
+    ARY_SET_LEN(dup, len);
+
+    ary_verify(ary);
+    ary_verify(dup);
+    return dup;
+}
 
-    CLONESETUP(ary2, ary);
-    MEMCPY(RARRAY(ary2)->ptr, RARRAY(ary)->ptr, VALUE, RARRAY(ary)->len);
-    RARRAY(ary2)->len = RARRAY(ary)->len;
-    return ary2;
+VALUE
+rb_ary_resurrect(VALUE ary)
+{
+    return ary_make_partial(ary, rb_cArray, 0, RARRAY_LEN(ary));
 }
 
+extern VALUE rb_output_fs;
+
+static void ary_join_1(VALUE obj, VALUE ary, VALUE sep, long i, VALUE result, int *first);
+
 static VALUE
-rb_ary_dup(ary)
-    VALUE ary;
+recursive_join(VALUE obj, VALUE argp, int recur)
 {
-    return rb_ary_new4(RARRAY(ary)->len, RARRAY(ary)->ptr);
+    VALUE *arg = (VALUE *)argp;
+    VALUE ary = arg[0];
+    VALUE sep = arg[1];
+    VALUE result = arg[2];
+    int *first = (int *)arg[3];
+
+    if (recur) {
+	rb_raise(rb_eArgError, "recursive array join");
+    }
+    else {
+	ary_join_1(obj, ary, sep, 0, result, first);
+    }
+    return Qnil;
 }
 
-static VALUE
-to_ary(ary)
-    VALUE ary;
+static long
+ary_join_0(VALUE ary, VALUE sep, long max, VALUE result)
 {
-    return rb_convert_type(ary, T_ARRAY, "Array", "to_ary");
+    long i;
+    VALUE val;
+
+    if (max > 0) rb_enc_copy(result, RARRAY_AREF(ary, 0));
+    for (i=0; i<max; i++) {
+	val = RARRAY_AREF(ary, i);
+        if (!RB_TYPE_P(val, T_STRING)) break;
+	if (i > 0 && !NIL_P(sep))
+	    rb_str_buf_append(result, sep);
+	rb_str_buf_append(result, val);
+    }
+    return i;
 }
 
-extern VALUE rb_output_fs;
+static void
+ary_join_1_str(VALUE dst, VALUE src, int *first)
+{
+    rb_str_buf_append(dst, src);
+    if (*first) {
+        rb_enc_copy(dst, src);
+        *first = FALSE;
+    }
+}
 
-static VALUE
-inspect_join(ary, arg)
-    VALUE ary;
-    VALUE *arg;
+static void
+ary_join_1_ary(VALUE obj, VALUE ary, VALUE sep, VALUE result, VALUE val, int *first)
 {
-    return rb_ary_join(arg[0], arg[1]);
+    if (val == ary) {
+        rb_raise(rb_eArgError, "recursive array join");
+    }
+    else {
+        VALUE args[4];
+
+        *first = FALSE;
+        args[0] = val;
+        args[1] = sep;
+        args[2] = result;
+        args[3] = (VALUE)first;
+        rb_exec_recursive(recursive_join, obj, (VALUE)args);
+    }
 }
 
-VALUE
-rb_ary_join(ary, sep)
-    VALUE ary, sep;
+static void
+ary_join_1(VALUE obj, VALUE ary, VALUE sep, long i, VALUE result, int *first)
 {
-    int i;
-    VALUE result, tmp;
-    if (RARRAY(ary)->len == 0) return rb_str_new(0, 0);
+    VALUE val, tmp;
 
-    tmp = RARRAY(ary)->ptr[0];
-    switch (TYPE(tmp)) {
-      case T_STRING:
-	result = rb_str_dup(tmp);
-	break;
-      case T_ARRAY:
-	if (rb_inspecting_p(tmp)) {
-	    result = rb_str_new2("[...]");
-	}
-	else {
-	    VALUE args[2];
+    for (; i<RARRAY_LEN(ary); i++) {
+	if (i > 0 && !NIL_P(sep))
+	    rb_str_buf_append(result, sep);
 
-	    args[0] = tmp;
-	    args[1] = sep;
-	    result = rb_protect_inspect(inspect_join, ary, (VALUE)args);
+	val = RARRAY_AREF(ary, i);
+	if (RB_TYPE_P(val, T_STRING)) {
+            ary_join_1_str(result, val, first);
+	}
+	else if (RB_TYPE_P(val, T_ARRAY)) {
+            ary_join_1_ary(val, ary, sep, result, val, first);
+	}
+        else if (!NIL_P(tmp = rb_check_string_type(val))) {
+            ary_join_1_str(result, tmp, first);
+        }
+        else if (!NIL_P(tmp = rb_check_array_type(val))) {
+            ary_join_1_ary(val, ary, sep, result, tmp, first);
+        }
+        else {
+            ary_join_1_str(result, rb_obj_as_string(val), first);
 	}
-	break;
-      default:
-	result = rb_obj_as_string(tmp);
-	break;
     }
+}
 
-    for (i=1; i<RARRAY(ary)->len; i++) {
-	tmp = RARRAY(ary)->ptr[i];
-	switch (TYPE(tmp)) {
-	  case T_STRING:
-	    break;
-	  case T_ARRAY:
-	    if (rb_inspecting_p(tmp)) {
-		tmp = rb_str_new2("[...]");
-	    }
-	    else {
-		VALUE args[2];
+VALUE
+rb_ary_join(VALUE ary, VALUE sep)
+{
+    long len = 1, i;
+    VALUE val, tmp, result;
 
-		args[0] = tmp;
-		args[1] = sep;
-		tmp = rb_protect_inspect(inspect_join, ary, (VALUE)args);
-	    }
-	    break;
-	  default:
-	    tmp = rb_obj_as_string(tmp);
+    if (RARRAY_LEN(ary) == 0) return rb_usascii_str_new(0, 0);
+
+    if (!NIL_P(sep)) {
+	StringValue(sep);
+	len += RSTRING_LEN(sep) * (RARRAY_LEN(ary) - 1);
+    }
+    for (i=0; i<RARRAY_LEN(ary); i++) {
+	val = RARRAY_AREF(ary, i);
+	tmp = rb_check_string_type(val);
+
+	if (NIL_P(tmp) || tmp != val) {
+	    int first;
+            long n = RARRAY_LEN(ary);
+            if (i > n) i = n;
+            result = rb_str_buf_new(len + (n-i)*10);
+	    rb_enc_associate(result, rb_usascii_encoding());
+            i = ary_join_0(ary, sep, i, result);
+	    first = i == 0;
+	    ary_join_1(ary, ary, sep, i, result, &first);
+	    return result;
 	}
-	if (!NIL_P(sep)) rb_str_concat(result, sep);
-	rb_str_cat(result, RSTRING(tmp)->ptr, RSTRING(tmp)->len);
-	if (OBJ_TAINTED(tmp)) OBJ_TAINT(result);
+
+	len += RSTRING_LEN(tmp);
     }
 
+    result = rb_str_new(0, len);
+    rb_str_set_len(result, 0);
+
+    ary_join_0(ary, sep, RARRAY_LEN(ary), result);
+
     return result;
 }
 
+/*
+ *  call-seq:
+ *    array.join ->new_string
+ *    array.join(separator = $,) -> new_string
+ *
+ *  Returns the new \String formed by joining the array elements after conversion.
+ *  For each element +element+
+ *  - Uses <tt>element.to_s</tt> if +element+ is not a <tt>kind_of?(Array)</tt>.
+ *  - Uses recursive <tt>element.join(separator)</tt> if +element+ is a <tt>kind_of?(Array)</tt>.
+ *
+ *  With no argument, joins using the output field separator, <tt>$,</tt>:
+ *    a = [:foo, 'bar', 2]
+ *    $, # => nil
+ *    a.join # => "foobar2"
+ *
+ *  With \string argument +separator+, joins using that separator:
+ *    a = [:foo, 'bar', 2]
+ *    a.join("\n") # => "foo\nbar\n2"
+ *
+ *  Joins recursively for nested Arrays:
+ *   a = [:foo, [:bar, [:baz, :bat]]]
+ *   a.join # => "foobarbazbat"
+ */
 static VALUE
-rb_ary_join_method(argc, argv, ary)
-    int argc;
-    VALUE *argv;
-    VALUE ary;
+rb_ary_join_m(int argc, VALUE *argv, VALUE ary)
 {
     VALUE sep;
 
-    rb_scan_args(argc, argv, "01", &sep);
-    if (NIL_P(sep)) sep = rb_output_fs;
+    if (rb_check_arity(argc, 0, 1) == 0 || NIL_P(sep = argv[0])) {
+        sep = rb_output_fs;
+        if (!NIL_P(sep)) {
+            rb_category_warn(RB_WARN_CATEGORY_DEPRECATED, "$, is set to non-nil value");
+        }
+    }
+
     return rb_ary_join(ary, sep);
 }
 
-VALUE
-rb_ary_to_s(ary)
-    VALUE ary;
+static VALUE
+inspect_ary(VALUE ary, VALUE dummy, int recur)
 {
-    VALUE str;
+    long i;
+    VALUE s, str;
 
-    if (RARRAY(ary)->len == 0) return rb_str_new(0, 0);
-    str = rb_ary_join(ary, rb_output_fs);
-    if (NIL_P(str)) return rb_str_new(0, 0);
+    if (recur) return rb_usascii_str_new_cstr("[...]");
+    str = rb_str_buf_new2("[");
+    for (i=0; i<RARRAY_LEN(ary); i++) {
+	s = rb_inspect(RARRAY_AREF(ary, i));
+	if (i > 0) rb_str_buf_cat2(str, ", ");
+	else rb_enc_copy(str, s);
+	rb_str_buf_append(str, s);
+    }
+    rb_str_buf_cat2(str, "]");
     return str;
 }
 
-#ifdef USE_THREAD
-static ID inspect_key;
-#else
-static VALUE inspect_tbl;
-#endif
+/*
+ *  call-seq:
+ *    array.inspect -> new_string
+ *
+ *  Returns the new \String formed by calling method <tt>#inspect</tt>
+ *  on each array element:
+ *    a = [:foo, 'bar', 2]
+ *    a.inspect # => "[:foo, \"bar\", 2]"
+ *
+ *  Array#to_s is an alias for Array#inspect.
+ */
 
-struct inspect_arg {
-    VALUE (*func)();
-    VALUE arg1, arg2;
-};
+static VALUE
+rb_ary_inspect(VALUE ary)
+{
+    if (RARRAY_LEN(ary) == 0) return rb_usascii_str_new2("[]");
+    return rb_exec_recursive(inspect_ary, ary, 0);
+}
 
 VALUE
-inspect_call(arg)
-    struct inspect_arg *arg;
+rb_ary_to_s(VALUE ary)
 {
-    return (*arg->func)(arg->arg1, arg->arg2);
+    return rb_ary_inspect(ary);
 }
 
+/*
+ *  call-seq:
+ *    to_a -> self or new_array
+ *
+ *  When +self+ is an instance of \Array, returns +self+:
+ *    a = [:foo, 'bar', 2]
+ *    a.to_a # => [:foo, "bar", 2]
+ *
+ *  Otherwise, returns a new \Array containing the elements of +self+:
+ *    class MyArray < Array; end
+ *    a = MyArray.new(['foo', 'bar', 'two'])
+ *    a.instance_of?(Array) # => false
+ *    a.kind_of?(Array) # => true
+ *    a1 = a.to_a
+ *    a1 # => ["foo", "bar", "two"]
+ *    a1.class # => Array # Not MyArray
+ */
+
 static VALUE
-inspect_ensure(obj)
-    VALUE obj;
+rb_ary_to_a(VALUE ary)
 {
-#ifdef USE_THREAD
-    VALUE inspect_tbl;
-
-    inspect_tbl = rb_thread_local_aref(rb_thread_current(), inspect_key);
-#endif
-    rb_ary_pop(inspect_tbl);
-    return 0;
+    if (rb_obj_class(ary) != rb_cArray) {
+	VALUE dup = rb_ary_new2(RARRAY_LEN(ary));
+	rb_ary_replace(dup, ary);
+	return dup;
+    }
+    return ary;
 }
 
-VALUE
-rb_protect_inspect(func, obj, arg)
-    VALUE (*func)();
-    VALUE obj, arg;
+/*
+ *  call-seq:
+ *    array.to_h -> new_hash
+ *    array.to_h {|item| ... } -> new_hash
+ *
+ *  Returns a new \Hash formed from +self+.
+ *
+ *  When a block is given, calls the block with each array element;
+ *  the block must return a 2-element \Array whose two elements
+ *  form a key-value pair in the returned \Hash:
+ *    a = ['foo', :bar, 1, [2, 3], {baz: 4}]
+ *    h = a.to_h {|item| [item, item] }
+ *    h # => {"foo"=>"foo", :bar=>:bar, 1=>1, [2, 3]=>[2, 3], {:baz=>4}=>{:baz=>4}}
+ *
+ *  When no block is given, +self+ must be an \Array of 2-element sub-arrays,
+ *  each sub-array is formed into a key-value pair in the new \Hash:
+ *    [].to_h # => {}
+ *    a = [['foo', 'zero'], ['bar', 'one'], ['baz', 'two']]
+ *    h = a.to_h
+ *    h # => {"foo"=>"zero", "bar"=>"one", "baz"=>"two"}
+ */
+
+static VALUE
+rb_ary_to_h(VALUE ary)
 {
-    struct inspect_arg iarg;
+    long i;
+    VALUE hash = rb_hash_new_with_size(RARRAY_LEN(ary));
+    int block_given = rb_block_given_p();
+
+    for (i=0; i<RARRAY_LEN(ary); i++) {
+	const VALUE e = rb_ary_elt(ary, i);
+	const VALUE elt = block_given ? rb_yield_force_blockarg(e) : e;
+	const VALUE key_value_pair = rb_check_array_type(elt);
+	if (NIL_P(key_value_pair)) {
+	    rb_raise(rb_eTypeError, "wrong element type %"PRIsVALUE" at %ld (expected array)",
+		     rb_obj_class(elt), i);
+	}
+	if (RARRAY_LEN(key_value_pair) != 2) {
+	    rb_raise(rb_eArgError, "wrong array length at %ld (expected 2, was %ld)",
+		i, RARRAY_LEN(key_value_pair));
+	}
+	rb_hash_aset(hash, RARRAY_AREF(key_value_pair, 0), RARRAY_AREF(key_value_pair, 1));
+    }
+    return hash;
+}
 
-#ifdef USE_THREAD
-    VALUE inspect_tbl;
+/*
+ *  call-seq:
+ *    array.to_ary -> self
+ *
+ *  Returns +self+.
+ */
 
-    if (!inspect_key) {
-	inspect_key = rb_intern("__inspect_key__");
-    }
-    inspect_tbl = rb_thread_local_aref(rb_thread_current(), inspect_key);
-    if (NIL_P(inspect_tbl)) {
-	inspect_tbl = rb_ary_new();
-	rb_thread_local_aset(rb_thread_current(), inspect_key, inspect_tbl);
-    }
-#else
-    if (!inspect_tbl) {
-	inspect_tbl = rb_ary_new();
-	rb_global_variable(&inspect_tbl);
+static VALUE
+rb_ary_to_ary_m(VALUE ary)
+{
+    return ary;
+}
+
+static void
+ary_reverse(VALUE *p1, VALUE *p2)
+{
+    while (p1 < p2) {
+	VALUE tmp = *p1;
+	*p1++ = *p2;
+	*p2-- = tmp;
     }
-#endif
-    rb_ary_push(inspect_tbl, obj);
-    iarg.func = func;
-    iarg.arg1 = obj;
-    iarg.arg2 = arg;
-    return rb_ensure(inspect_call, (VALUE)&iarg, inspect_ensure, obj);
 }
 
 VALUE
-rb_inspecting_p(obj)
-    VALUE obj;
+rb_ary_reverse(VALUE ary)
 {
-#ifdef USE_THREAD
-    VALUE inspect_tbl;
+    VALUE *p2;
+    long len = RARRAY_LEN(ary);
 
-    if (!inspect_key) return Qfalse;
-    inspect_tbl = rb_thread_local_aref(rb_thread_current(), inspect_key);
-    if (NIL_P(inspect_tbl)) return Qfalse;
-#else
-    if (!inspect_tbl) return Qnil;
-#endif
-    return rb_ary_includes(inspect_tbl, obj);
+    rb_ary_modify(ary);
+    if (len > 1) {
+        RARRAY_PTR_USE_TRANSIENT(ary, p1, {
+            p2 = p1 + len - 1;	/* points last item */
+            ary_reverse(p1, p2);
+	}); /* WB: no new reference */
+    }
+    return ary;
 }
 
+/*
+ *  call-seq:
+ *    array.reverse! -> self
+ *
+ *  Reverses +self+ in place:
+ *    a = ['foo', 'bar', 'two']
+ *    a.reverse! # => ["two", "bar", "foo"]
+ */
+
 static VALUE
-inspect_ary(ary)
-    VALUE ary;
+rb_ary_reverse_bang(VALUE ary)
 {
-    int i = 0;
-    VALUE s, str;
+    return rb_ary_reverse(ary);
+}
 
-    str = rb_str_new2("[");
+/*
+ *  call-seq:
+ *    array.reverse -> new_array
+ *
+ *  Returns a new \Array with the elements of +self+ in reverse order.
+ *    a = ['foo', 'bar', 'two']
+ *    a1 = a.reverse
+ *    a1 # => ["two", "bar", "foo"]
+ */
 
-    for (i=0; i<RARRAY(ary)->len; i++) {
-	s = rb_inspect(RARRAY(ary)->ptr[i]);
-	if (i > 0) rb_str_cat(str, ", ", 2);
-	rb_str_cat(str, RSTRING(s)->ptr, RSTRING(s)->len);
+static VALUE
+rb_ary_reverse_m(VALUE ary)
+{
+    long len = RARRAY_LEN(ary);
+    VALUE dup = rb_ary_new2(len);
+
+    if (len > 0) {
+        const VALUE *p1 = RARRAY_CONST_PTR_TRANSIENT(ary);
+        VALUE *p2 = (VALUE *)RARRAY_CONST_PTR_TRANSIENT(dup) + len - 1;
+	do *p2-- = *p1++; while (--len > 0);
     }
-    rb_str_cat(str, "]", 1);
+    ARY_SET_LEN(dup, RARRAY_LEN(ary));
+    return dup;
+}
 
-    return str;
+static inline long
+rotate_count(long cnt, long len)
+{
+    return (cnt < 0) ? (len - (~cnt % len) - 1) : (cnt % len);
 }
 
+static void
+ary_rotate_ptr(VALUE *ptr, long len, long cnt)
+{
+    if (cnt == 1) {
+        VALUE tmp = *ptr;
+        memmove(ptr, ptr + 1, sizeof(VALUE)*(len - 1));
+        *(ptr + len - 1) = tmp;
+    } else if (cnt == len - 1) {
+        VALUE tmp = *(ptr + len - 1);
+        memmove(ptr + 1, ptr, sizeof(VALUE)*(len - 1));
+        *ptr = tmp;
+    } else {
+        --len;
+        if (cnt < len) ary_reverse(ptr + cnt, ptr + len);
+        if (--cnt > 0) ary_reverse(ptr, ptr + cnt);
+        if (len > 0) ary_reverse(ptr, ptr + len);
+    }
+}
+
+VALUE
+rb_ary_rotate(VALUE ary, long cnt)
+{
+    rb_ary_modify(ary);
+
+    if (cnt != 0) {
+        long len = RARRAY_LEN(ary);
+        if (len > 1 && (cnt = rotate_count(cnt, len)) > 0) {
+            RARRAY_PTR_USE_TRANSIENT(ary, ptr, ary_rotate_ptr(ptr, len, cnt));
+            return ary;
+        }
+    }
+    return Qnil;
+}
+
+/*
+ *  call-seq:
+ *    array.rotate! -> self
+ *    array.rotate!(count) -> self
+ *
+ *  Rotates +self+ in place by moving elements from one end to the other; returns +self+.
+ *
+ *  When no argument given, rotates the first element to the last position:
+ *    a = [:foo, 'bar', 2, 'bar']
+ *    a.rotate! # => ["bar", 2, "bar", :foo]
+ *
+ *  When given a non-negative \Integer +count+,
+ *  rotates +count+ elements from the beginning to the end:
+ *    a = [:foo, 'bar', 2]
+ *    a.rotate!(2)
+ *    a # => [2, :foo, "bar"]
+ *
+ *  If +count+ is large, uses <tt>count % array.size</tt> as the count:
+ *    a = [:foo, 'bar', 2]
+ *    a.rotate!(20)
+ *    a # => [2, :foo, "bar"]
+ *
+ *  If +count+ is zero, returns +self+ unmodified:
+ *    a = [:foo, 'bar', 2]
+ *    a.rotate!(0)
+ *    a # => [:foo, "bar", 2]
+ *
+ *  When given a negative Integer +count+, rotates in the opposite direction,
+ *  from end to beginning:
+ *    a = [:foo, 'bar', 2]
+ *    a.rotate!(-2)
+ *    a # => ["bar", 2, :foo]
+ *
+ *  If +count+ is small (far from zero), uses <tt>count % array.size</tt> as the count:
+ *    a = [:foo, 'bar', 2]
+ *    a.rotate!(-5)
+ *    a # => ["bar", 2, :foo]
+ */
+
 static VALUE
-rb_ary_inspect(ary)
-    VALUE ary;
+rb_ary_rotate_bang(int argc, VALUE *argv, VALUE ary)
 {
-    if (RARRAY(ary)->len == 0) return rb_str_new2("[]");
-    if (rb_inspecting_p(ary)) return rb_str_new2("[...]");
-    return rb_protect_inspect(inspect_ary, ary, 0);
+    long n = (rb_check_arity(argc, 0, 1) ? NUM2LONG(argv[0]) : 1);
+    rb_ary_rotate(ary, n);
+    return ary;
 }
 
+/*
+ *  call-seq:
+ *    array.rotate -> new_array
+ *    array.rotate(count) -> new_array
+ *
+ *  Returns a new \Array formed from +self+ with elements
+ *  rotated from one end to the other.
+ *
+ *  When no argument given, returns a new \Array that is like +self+,
+ *  except that the first element has been rotated to the last position:
+ *    a = [:foo, 'bar', 2, 'bar']
+ *    a1 = a.rotate
+ *    a1 # => ["bar", 2, "bar", :foo]
+ *
+ *  When given a non-negative \Integer +count+,
+ *  returns a new \Array with +count+ elements rotated from the beginning to the end:
+ *    a = [:foo, 'bar', 2]
+ *    a1 = a.rotate(2)
+ *    a1 # => [2, :foo, "bar"]
+ *
+ *  If +count+ is large, uses <tt>count % array.size</tt> as the count:
+ *    a = [:foo, 'bar', 2]
+ *    a1 = a.rotate(20)
+ *    a1 # => [2, :foo, "bar"]
+ *
+ *  If +count+ is zero, returns a copy of +self+, unmodified:
+ *    a = [:foo, 'bar', 2]
+ *    a1 = a.rotate(0)
+ *    a1 # => [:foo, "bar", 2]
+ *
+ *  When given a negative \Integer +count+, rotates in the opposite direction,
+ *  from end to beginning:
+ *    a = [:foo, 'bar', 2]
+ *    a1 = a.rotate(-2)
+ *    a1 # => ["bar", 2, :foo]
+ *
+ *  If +count+ is small (far from zero), uses <tt>count % array.size</tt> as the count:
+ *    a = [:foo, 'bar', 2]
+ *    a1 = a.rotate(-5)
+ *    a1 # => ["bar", 2, :foo]
+ */
+
 static VALUE
-rb_ary_to_a(ary)
+rb_ary_rotate_m(int argc, VALUE *argv, VALUE ary)
+{
+    VALUE rotated;
+    const VALUE *ptr;
+    long len;
+    long cnt = (rb_check_arity(argc, 0, 1) ? NUM2LONG(argv[0]) : 1);
+
+    len = RARRAY_LEN(ary);
+    rotated = rb_ary_new2(len);
+    if (len > 0) {
+	cnt = rotate_count(cnt, len);
+        ptr = RARRAY_CONST_PTR_TRANSIENT(ary);
+	len -= cnt;
+	ary_memcpy(rotated, 0, len, ptr + cnt);
+	ary_memcpy(rotated, len, cnt, ptr);
+    }
+    ARY_SET_LEN(rotated, RARRAY_LEN(ary));
+    return rotated;
+}
+
+struct ary_sort_data {
     VALUE ary;
+    struct cmp_opt_data cmp_opt;
+};
+
+static VALUE
+sort_reentered(VALUE ary)
 {
+    if (RBASIC(ary)->klass) {
+	rb_raise(rb_eRuntimeError, "sort reentered");
+    }
+    return Qnil;
+}
+
+static int
+sort_1(const void *ap, const void *bp, void *dummy)
+{
+    struct ary_sort_data *data = dummy;
+    VALUE retval = sort_reentered(data->ary);
+    VALUE a = *(const VALUE *)ap, b = *(const VALUE *)bp;
+    VALUE args[2];
+    int n;
+
+    args[0] = a;
+    args[1] = b;
+    retval = rb_yield_values2(2, args);
+    n = rb_cmpint(retval, a, b);
+    sort_reentered(data->ary);
+    return n;
+}
+
+static int
+sort_2(const void *ap, const void *bp, void *dummy)
+{
+    struct ary_sort_data *data = dummy;
+    VALUE retval = sort_reentered(data->ary);
+    VALUE a = *(const VALUE *)ap, b = *(const VALUE *)bp;
+    int n;
+
+    if (FIXNUM_P(a) && FIXNUM_P(b) && CMP_OPTIMIZABLE(data->cmp_opt, Integer)) {
+	if ((long)a > (long)b) return 1;
+	if ((long)a < (long)b) return -1;
+	return 0;
+    }
+    if (STRING_P(a) && STRING_P(b) && CMP_OPTIMIZABLE(data->cmp_opt, String)) {
+	return rb_str_cmp(a, b);
+    }
+    if (RB_FLOAT_TYPE_P(a) && CMP_OPTIMIZABLE(data->cmp_opt, Float)) {
+	return rb_float_cmp(a, b);
+    }
+
+    retval = rb_funcallv(a, id_cmp, 1, &b);
+    n = rb_cmpint(retval, a, b);
+    sort_reentered(data->ary);
+
+    return n;
+}
+
+/*
+ *  call-seq:
+ *    array.sort! -> self
+ *    array.sort! {|a, b| ... } -> self
+ *
+ *  Returns +self+ with its elements sorted in place.
+ *
+ *  With no block, compares elements using operator <tt><=></tt>
+ *  (see Comparable):
+ *    a = 'abcde'.split('').shuffle
+ *    a # => ["e", "b", "d", "a", "c"]
+ *    a.sort!
+ *    a # => ["a", "b", "c", "d", "e"]
+ *
+ *  With a block, calls the block with each element pair;
+ *  for each element pair +a+ and +b+, the block should return an integer:
+ *  - Negative when +b+ is to follow +a+.
+ *  - Zero when +a+ and +b+ are equivalent.
+ *  - Positive when +a+ is to follow +b+.
+ *
+ *  Example:
+ *    a = 'abcde'.split('').shuffle
+ *    a # => ["e", "b", "d", "a", "c"]
+ *    a.sort! {|a, b| a <=> b }
+ *    a # => ["a", "b", "c", "d", "e"]
+ *    a.sort! {|a, b| b <=> a }
+ *    a # => ["e", "d", "c", "b", "a"]
+ *
+ *  When the block returns zero, the order for +a+ and +b+ is indeterminate,
+ *  and may be unstable:
+ *    a = 'abcde'.split('').shuffle
+ *    a # => ["e", "b", "d", "a", "c"]
+ *    a.sort! {|a, b| 0 }
+ *    a # => ["d", "e", "c", "a", "b"]
+ */
+
+VALUE
+rb_ary_sort_bang(VALUE ary)
+{
+    rb_ary_modify(ary);
+    assert(!ARY_SHARED_P(ary));
+    if (RARRAY_LEN(ary) > 1) {
+	VALUE tmp = ary_make_substitution(ary); /* only ary refers tmp */
+	struct ary_sort_data data;
+	long len = RARRAY_LEN(ary);
+	RBASIC_CLEAR_CLASS(tmp);
+	data.ary = tmp;
+	data.cmp_opt.opt_methods = 0;
+	data.cmp_opt.opt_inited = 0;
+	RARRAY_PTR_USE(tmp, ptr, {
+            ruby_qsort(ptr, len, sizeof(VALUE),
+                       rb_block_given_p()?sort_1:sort_2, &data);
+	}); /* WB: no new reference */
+	rb_ary_modify(ary);
+        if (ARY_EMBED_P(tmp)) {
+            if (ARY_SHARED_P(ary)) { /* ary might be destructively operated in the given block */
+                rb_ary_unshare(ary);
+		FL_SET_EMBED(ary);
+            }
+	    ary_memcpy(ary, 0, ARY_EMBED_LEN(tmp), ARY_EMBED_PTR(tmp));
+            ARY_SET_LEN(ary, ARY_EMBED_LEN(tmp));
+        }
+        else {
+            if (!ARY_EMBED_P(ary) && ARY_HEAP_PTR(ary) == ARY_HEAP_PTR(tmp)) {
+                FL_UNSET_SHARED(ary);
+                ARY_SET_CAPA(ary, RARRAY_LEN(tmp));
+            }
+            else {
+                assert(!ARY_SHARED_P(tmp));
+                if (ARY_EMBED_P(ary)) {
+                    FL_UNSET_EMBED(ary);
+                }
+                else if (ARY_SHARED_P(ary)) {
+                    /* ary might be destructively operated in the given block */
+                    rb_ary_unshare(ary);
+                }
+                else {
+                    ary_heap_free(ary);
+                }
+                ARY_SET_PTR(ary, ARY_HEAP_PTR(tmp));
+                ARY_SET_HEAP_LEN(ary, len);
+                ARY_SET_CAPA(ary, ARY_HEAP_LEN(tmp));
+            }
+            /* tmp was lost ownership for the ptr */
+            FL_UNSET(tmp, FL_FREEZE);
+            FL_SET_EMBED(tmp);
+            ARY_SET_EMBED_LEN(tmp, 0);
+            FL_SET(tmp, FL_FREEZE);
+        }
+        /* tmp will be GC'ed. */
+        RBASIC_SET_CLASS_RAW(tmp, rb_cArray); /* rb_cArray must be marked */
+    }
+    ary_verify(ary);
     return ary;
 }
 
+/*
+ *  call-seq:
+ *    array.sort -> new_array
+ *    array.sort {|a, b| ... } -> new_array
+ *
+ *  Returns a new \Array whose elements are those from +self+, sorted.
+ *
+ *  With no block, compares elements using operator <tt><=></tt>
+ *  (see Comparable):
+ *    a = 'abcde'.split('').shuffle
+ *    a # => ["e", "b", "d", "a", "c"]
+ *    a1 = a.sort
+ *    a1 # => ["a", "b", "c", "d", "e"]
+ *
+ *  With a block, calls the block with each element pair;
+ *  for each element pair +a+ and +b+, the block should return an integer:
+ *  - Negative when +b+ is to follow +a+.
+ *  - Zero when +a+ and +b+ are equivalent.
+ *  - Positive when +a+ is to follow +b+.
+ *
+ *  Example:
+ *    a = 'abcde'.split('').shuffle
+ *    a # => ["e", "b", "d", "a", "c"]
+ *    a1 = a.sort {|a, b| a <=> b }
+ *    a1 # => ["a", "b", "c", "d", "e"]
+ *    a2 = a.sort {|a, b| b <=> a }
+ *    a2 # => ["e", "d", "c", "b", "a"]
+ *
+ *  When the block returns zero, the order for +a+ and +b+ is indeterminate,
+ *  and may be unstable:
+ *    a = 'abcde'.split('').shuffle
+ *    a # => ["e", "b", "d", "a", "c"]
+ *    a1 = a.sort {|a, b| 0 }
+ *    a1 # =>  ["c", "e", "b", "d", "a"]
+ *
+ *  Related: Enumerable#sort_by.
+ */
+
 VALUE
-rb_ary_reverse(ary)
-    VALUE ary;
+rb_ary_sort(VALUE ary)
 {
-    VALUE *p1, *p2;
-    VALUE tmp;
+    ary = rb_ary_dup(ary);
+    rb_ary_sort_bang(ary);
+    return ary;
+}
 
-    if (RARRAY(ary)->len == 0) return ary;
+static VALUE rb_ary_bsearch_index(VALUE ary);
+
+/*
+ *  call-seq:
+ *    array.bsearch {|element| ... } -> object
+ *    array.bsearch -> new_enumerator
+ *
+ *  Returns an element from +self+ selected by a binary search.
+ *  +self+ should be sorted, but this is not checked.
+ *
+ *  By using binary search, finds a value from this array which meets
+ *  the given condition in <tt>O(log n)</tt> where +n+ is the size of the array.
+ *
+ *  There are two search modes:
+ *  - <b>Find-minimum mode</b>: the block should return +true+ or +false+.
+ *  - <b>Find-any mode</b>: the block should return a numeric value.
+ *
+ *  The block should not mix the modes by and sometimes returning +true+ or +false+
+ *  and sometimes returning a numeric value, but this is not checked.
+ *
+ *  <b>Find-Minimum Mode</b>
+ *
+ *  In find-minimum mode, the block always returns +true+ or +false+.
+ *  The further requirement (though not checked) is that
+ *  there are no indexes +i+ and +j+ such that:
+ *  - <tt>0 <= i < j <= self.size</tt>.
+ *  - The block returns +true+ for <tt>self[i]</tt> and +false+ for <tt>self[j]</tt>.
+ *
+ *  In find-minimum mode, method bsearch returns the first element for which the block returns true.
+ *
+ *  Examples:
+ *    a = [0, 4, 7, 10, 12]
+ *    a.bsearch {|x| x >= 4 } # => 4
+ *    a.bsearch {|x| x >= 6 } # => 7
+ *    a.bsearch {|x| x >= -1 } # => 0
+ *    a.bsearch {|x| x >= 100 } # => nil
+ *
+ *  Less formally: the block is such that all +false+-evaluating elements
+ *  precede all +true+-evaluating elements.
+ *
+ *  These make sense as blocks in find-minimum mode:
+ *    a = [0, 4, 7, 10, 12]
+ *    a.map {|x| x >= 4 } # => [false, true, true, true, true]
+ *    a.map {|x| x >= 6 } # => [false, false, true, true, true]
+ *    a.map {|x| x >= -1 } # => [true, true, true, true, true]
+ *    a.map {|x| x >= 100 } # => [false, false, false, false, false]
+ *
+ *  This would not make sense:
+ *    a = [0, 4, 7, 10, 12]
+ *    a.map {|x| x == 7 } # => [false, false, true, false, false]
+ *
+ *  <b>Find-Any Mode</b>
+ *
+ *  In find-any mode, the block always returns a numeric value.
+ *  The further requirement (though not checked) is that
+ *  there are no indexes +i+ and +j+ such that:
+ *  - <tt>0 <= i < j <= self.size</tt>.
+ *  - The block returns a negative value for <tt>self[i]</tt>
+ *    and a positive value for <tt>self[j]</tt>.
+ *  - The block returns a negative value for <tt>self[i]</tt> and zero <tt>self[j]</tt>.
+ *  - The block returns zero for <tt>self[i]</tt> and a positive value for <tt>self[j]</tt>.
+ *
+ *  In find-any mode, method bsearch returns some element
+ *  for which the block returns zero, or +nil+ if no such element is found.
+ *
+ *  Examples:
+ *    a = [0, 4, 7, 10, 12]
+ *    a.bsearch {|element| 7 <=> element } # => 7
+ *    a.bsearch {|element| -1 <=> element } # => nil
+ *    a.bsearch {|element| 5 <=> element } # => nil
+ *    a.bsearch {|element| 15 <=> element } # => nil
+ *
+ *  Less formally: the block is such that:
+ *  - All positive-evaluating elements precede all zero-evaluating elements.
+ *  - All positive-evaluating elements precede all negative-evaluating elements.
+ *  - All zero-evaluating elements precede all negative-evaluating elements.
+ *
+ *  These make sense as blocks in find-any mode:
+ *    a = [0, 4, 7, 10, 12]
+ *    a.map {|element| 7 <=> element } # => [1, 1, 0, -1, -1]
+ *    a.map {|element| -1 <=> element } # => [-1, -1, -1, -1, -1]
+ *    a.map {|element| 5 <=> element } # => [1, 1, -1, -1, -1]
+ *    a.map {|element| 15 <=> element } # => [1, 1, 1, 1, 1]
+ *
+ *  This would not make sense:
+ *    a = [0, 4, 7, 10, 12]
+ *    a.map {|element| element <=> 7 } # => [-1, -1, 0, 1, 1]
+ *
+ *  Returns an enumerator if no block given:
+ *    a = [0, 4, 7, 10, 12]
+ *    a.bsearch # => #<Enumerator: [0, 4, 7, 10, 12]:bsearch>
+ */
 
-    p1 = RARRAY(ary)->ptr;
-    p2 = p1 + RARRAY(ary)->len - 1;	/* points last item */
+static VALUE
+rb_ary_bsearch(VALUE ary)
+{
+    VALUE index_result = rb_ary_bsearch_index(ary);
 
-    while (p1 < p2) {
-	tmp = *p1;
-	*p1 = *p2;
-	*p2 = tmp;
-	p1++; p2--;
+    if (FIXNUM_P(index_result)) {
+	return rb_ary_entry(ary, FIX2LONG(index_result));
     }
+    return index_result;
+}
+
+/*
+ *  call-seq:
+ *    array.bsearch_index {|element| ... } -> integer or nil
+ *    array.bsearch_index -> new_enumerator
+ *
+ *  Searches +self+ as described at method #bsearch,
+ *  but returns the _index_ of the found element instead of the element itself.
+ */
 
+static VALUE
+rb_ary_bsearch_index(VALUE ary)
+{
+    long low = 0, high = RARRAY_LEN(ary), mid;
+    int smaller = 0, satisfied = 0;
+    VALUE v, val;
+
+    RETURN_ENUMERATOR(ary, 0, 0);
+    while (low < high) {
+	mid = low + ((high - low) / 2);
+	val = rb_ary_entry(ary, mid);
+	v = rb_yield(val);
+	if (FIXNUM_P(v)) {
+	    if (v == INT2FIX(0)) return INT2FIX(mid);
+	    smaller = (SIGNED_VALUE)v < 0; /* Fixnum preserves its sign-bit */
+	}
+	else if (v == Qtrue) {
+	    satisfied = 1;
+	    smaller = 1;
+	}
+	else if (v == Qfalse || v == Qnil) {
+	    smaller = 0;
+	}
+	else if (rb_obj_is_kind_of(v, rb_cNumeric)) {
+	    const VALUE zero = INT2FIX(0);
+	    switch (rb_cmpint(rb_funcallv(v, id_cmp, 1, &zero), v, zero)) {
+	      case 0: return INT2FIX(mid);
+	      case 1: smaller = 1; break;
+	      case -1: smaller = 0;
+	    }
+	}
+	else {
+	    rb_raise(rb_eTypeError, "wrong argument type %"PRIsVALUE
+		     " (must be numeric, true, false or nil)",
+		     rb_obj_class(v));
+	}
+	if (smaller) {
+	    high = mid;
+	}
+	else {
+	    low = mid + 1;
+	}
+    }
+    if (!satisfied) return Qnil;
+    return INT2FIX(low);
+}
+
+
+static VALUE
+sort_by_i(RB_BLOCK_CALL_FUNC_ARGLIST(i, dummy))
+{
+    return rb_yield(i);
+}
+
+/*
+ *  call-seq:
+ *    array.sort_by! {|element| ... } -> self
+ *    array.sort_by! -> new_enumerator
+ *
+ *  Sorts the elements of +self+ in place,
+ *  using an ordering determined by the block; returns self.
+ *
+ *  Calls the block with each successive element;
+ *  sorts elements based on the values returned from the block.
+ *
+ *  For duplicates returned by the block, the ordering is indeterminate, and may be unstable.
+ *
+ *  This example sorts strings based on their sizes:
+ *    a = ['aaaa', 'bbb', 'cc', 'd']
+ *    a.sort_by! {|element| element.size }
+ *    a # => ["d", "cc", "bbb", "aaaa"]
+ *
+ *  Returns a new \Enumerator if no block given:
+ *
+ *    a = ['aaaa', 'bbb', 'cc', 'd']
+ *    a.sort_by! # => #<Enumerator: ["aaaa", "bbb", "cc", "d"]:sort_by!>
+ */
+
+static VALUE
+rb_ary_sort_by_bang(VALUE ary)
+{
+    VALUE sorted;
+
+    RETURN_SIZED_ENUMERATOR(ary, 0, 0, ary_enum_length);
+    rb_ary_modify(ary);
+    sorted = rb_block_call(ary, rb_intern("sort_by"), 0, 0, sort_by_i, 0);
+    rb_ary_replace(ary, sorted);
     return ary;
 }
 
+
+/*
+ *  call-seq:
+ *    array.map {|element| ... } -> new_array
+ *    array.map -> new_enumerator
+ *
+ *  Calls the block, if given, with each element of +self+;
+ *  returns a new \Array whose elements are the return values from the block:
+ *    a = [:foo, 'bar', 2]
+ *    a1 = a.map {|element| element.class }
+ *    a1 # => [Symbol, String, Integer]
+ *
+ *  Returns a new \Enumerator if no block given:
+ *    a = [:foo, 'bar', 2]
+ *    a1 = a.map
+ *    a1 # => #<Enumerator: [:foo, "bar", 2]:map>
+ *
+ *  Array#collect is an alias for Array#map.
+ */
+
 static VALUE
-rb_ary_reverse_method(ary)
-    VALUE ary;
+rb_ary_collect(VALUE ary)
 {
-    return rb_ary_reverse(rb_ary_dup(ary));
+    long i;
+    VALUE collect;
+
+    RETURN_SIZED_ENUMERATOR(ary, 0, 0, ary_enum_length);
+    collect = rb_ary_new2(RARRAY_LEN(ary));
+    for (i = 0; i < RARRAY_LEN(ary); i++) {
+        rb_ary_push(collect, rb_yield(RARRAY_AREF(ary, i)));
+    }
+    return collect;
 }
 
-static ID cmp;
 
-static int
-sort_1(a, b)
-    VALUE *a, *b;
+/*
+ *  call-seq:
+ *    array.map! {|element| ... } -> self
+ *    array.map! -> new_enumerator
+ *
+ *  Calls the block, if given, with each element;
+ *  replaces the element with the block's return value:
+ *    a = [:foo, 'bar', 2]
+ *    a.map! { |element| element.class } # => [Symbol, String, Integer]
+ *
+ *  Returns a new \Enumerator if no block given:
+ *    a = [:foo, 'bar', 2]
+ *    a1 = a.map!
+ *    a1 # => #<Enumerator: [:foo, "bar", 2]:map!>
+ *
+ *  Array#collect! is an alias for Array#map!.
+ */
+
+static VALUE
+rb_ary_collect_bang(VALUE ary)
 {
-    VALUE retval = rb_yield(rb_assoc_new(*a, *b));
-    return NUM2INT(retval);
+    long i;
+
+    RETURN_SIZED_ENUMERATOR(ary, 0, 0, ary_enum_length);
+    rb_ary_modify(ary);
+    for (i = 0; i < RARRAY_LEN(ary); i++) {
+	rb_ary_store(ary, i, rb_yield(RARRAY_AREF(ary, i)));
+    }
+    return ary;
 }
 
-static int
-sort_2(a, b)
-    VALUE *a, *b;
+VALUE
+rb_get_values_at(VALUE obj, long olen, int argc, const VALUE *argv, VALUE (*func) (VALUE, long))
 {
-    VALUE retval;
+    VALUE result = rb_ary_new2(argc);
+    long beg, len, i, j;
 
-    if (FIXNUM_P(*a)) {
-	if (FIXNUM_P(*b)) return *a - *b;
+    for (i=0; i<argc; i++) {
+	if (FIXNUM_P(argv[i])) {
+	    rb_ary_push(result, (*func)(obj, FIX2LONG(argv[i])));
+	    continue;
+	}
+	/* check if idx is Range */
+	if (rb_range_beg_len(argv[i], &beg, &len, olen, 1)) {
+	    long end = olen < beg+len ? olen : beg+len;
+	    for (j = beg; j < end; j++) {
+		rb_ary_push(result, (*func)(obj, j));
+	    }
+	    if (beg + len > j)
+		rb_ary_resize(result, RARRAY_LEN(result) + (beg + len) - j);
+	    continue;
+	}
+	rb_ary_push(result, (*func)(obj, NUM2LONG(argv[i])));
     }
-    else if (TYPE(*a) == T_STRING && TYPE(*b) == T_STRING) {
-	return rb_str_cmp(*a, *b);
+    return result;
+}
+
+static VALUE
+append_values_at_single(VALUE result, VALUE ary, long olen, VALUE idx)
+{
+    long beg, len;
+    if (FIXNUM_P(idx)) {
+	beg = FIX2LONG(idx);
     }
+    /* check if idx is Range */
+    else if (rb_range_beg_len(idx, &beg, &len, olen, 1)) {
+	if (len > 0) {
+            const VALUE *const src = RARRAY_CONST_PTR_TRANSIENT(ary);
+	    const long end = beg + len;
+	    const long prevlen = RARRAY_LEN(result);
+	    if (beg < olen) {
+		rb_ary_cat(result, src + beg, end > olen ? olen-beg : len);
+	    }
+	    if (end > olen) {
+		rb_ary_store(result, prevlen + len - 1, Qnil);
+	    }
+	}
+	return result;
+    }
+    else {
+	beg = NUM2LONG(idx);
+    }
+    return rb_ary_push(result, rb_ary_entry(ary, beg));
+}
+
+/*
+ *  call-seq:
+ *    array.values_at(*indexes) -> new_array
+ *
+ *  Returns a new \Array whose elements are the elements
+ *  of +self+ at the given \Integer +indexes+.
+ *
+ *  For each positive +index+, returns the element at offset +index+:
+ *    a = [:foo, 'bar', 2]
+ *    a.values_at(0, 2) # => [:foo, 2]
+ *
+ *  The given +indexes+ may be in any order, and may repeat:
+ *    a = [:foo, 'bar', 2]
+ *    a.values_at(2, 0, 1, 0, 2) # => [2, :foo, "bar", :foo, 2]
+ *
+ *  Assigns +nil+ for an +index+ that is too large:
+ *    a = [:foo, 'bar', 2]
+ *    a.values_at(0, 3, 1, 3) # => [:foo, nil, "bar", nil]
+ *
+ *  Returns a new empty \Array if no arguments given.
+ *
+ *  For each negative +index+, counts backward from the end of the array:
+ *    a = [:foo, 'bar', 2]
+ *    a.values_at(-1, -3) # => [2, :foo]
+ *
+ *  Assigns +nil+ for an +index+ that is too small:
+ *    a = [:foo, 'bar', 2]
+ *    a.values_at(0, -5, 1, -6, 2) # => [:foo, nil, "bar", nil, 2]
+ *
+ *  The given +indexes+ may have a mixture of signs:
+ *    a = [:foo, 'bar', 2]
+ *    a.values_at(0, -2, 1, -1) # => [:foo, "bar", "bar", 2]
+ */
 
-    retval = rb_funcall(*a, cmp, 1, *b);
-    return NUM2INT(retval);
+static VALUE
+rb_ary_values_at(int argc, VALUE *argv, VALUE ary)
+{
+    long i, olen = RARRAY_LEN(ary);
+    VALUE result = rb_ary_new_capa(argc);
+    for (i = 0; i < argc; ++i) {
+	append_values_at_single(result, ary, olen, argv[i]);
+    }
+    RB_GC_GUARD(ary);
+    return result;
 }
 
+
+/*
+ *  call-seq:
+ *    array.select {|element| ... } -> new_array
+ *    array.select -> new_enumerator
+ *
+ *  Calls the block, if given, with each element of +self+;
+ *  returns a new \Array containing those elements of +self+
+ *  for which the block returns a truthy value:
+ *    a = [:foo, 'bar', 2, :bam]
+ *    a1 = a.select {|element| element.to_s.start_with?('b') }
+ *    a1 # => ["bar", :bam]
+ *
+ *  Returns a new \Enumerator if no block given:
+ *    a = [:foo, 'bar', 2, :bam]
+ *    a.select # => #<Enumerator: [:foo, "bar", 2, :bam]:select>
+ *
+ *  Array#filter is an alias for Array#select.
+ */
+
 static VALUE
-sort_internal(ary)
+rb_ary_select(VALUE ary)
+{
+    VALUE result;
+    long i;
+
+    RETURN_SIZED_ENUMERATOR(ary, 0, 0, ary_enum_length);
+    result = rb_ary_new2(RARRAY_LEN(ary));
+    for (i = 0; i < RARRAY_LEN(ary); i++) {
+	if (RTEST(rb_yield(RARRAY_AREF(ary, i)))) {
+	    rb_ary_push(result, rb_ary_elt(ary, i));
+	}
+    }
+    return result;
+}
+
+struct select_bang_arg {
     VALUE ary;
+    long len[2];
+};
+
+static VALUE
+select_bang_i(VALUE a)
 {
-    qsort(RARRAY(ary)->ptr, RARRAY(ary)->len, sizeof(VALUE),
-	  rb_iterator_p()?sort_1:sort_2);
-    return ary;
+    volatile struct select_bang_arg *arg = (void *)a;
+    VALUE ary = arg->ary;
+    long i1, i2;
+
+    for (i1 = i2 = 0; i1 < RARRAY_LEN(ary); arg->len[0] = ++i1) {
+	VALUE v = RARRAY_AREF(ary, i1);
+	if (!RTEST(rb_yield(v))) continue;
+	if (i1 != i2) {
+	    rb_ary_store(ary, i2, v);
+	}
+	arg->len[1] = ++i2;
+    }
+    return (i1 == i2) ? Qnil : ary;
 }
 
 static VALUE
-sort_unlock(ary)
-    VALUE ary;
+select_bang_ensure(VALUE a)
 {
-    FL_UNSET(ary, ARY_TMPLOCK);
+    volatile struct select_bang_arg *arg = (void *)a;
+    VALUE ary = arg->ary;
+    long len = RARRAY_LEN(ary);
+    long i1 = arg->len[0], i2 = arg->len[1];
+
+    if (i2 < len && i2 < i1) {
+	long tail = 0;
+        rb_ary_modify(ary);
+	if (i1 < len) {
+	    tail = len - i1;
+            RARRAY_PTR_USE_TRANSIENT(ary, ptr, {
+		    MEMMOVE(ptr + i2, ptr + i1, VALUE, tail);
+		});
+	}
+	ARY_SET_LEN(ary, i2 + tail);
+    }
     return ary;
 }
 
-VALUE
-rb_ary_sort_bang(ary)
-    VALUE ary;
+/*
+ *  call-seq:
+ *    array.select! {|element| ... } -> self or nil
+ *    array.select! -> new_enumerator
+ *
+ *  Calls the block, if given  with each element of +self+;
+ *  removes from +self+ those elements for which the block returns +false+ or +nil+.
+ *
+ *  Returns +self+ if any elements were removed:
+ *    a = [:foo, 'bar', 2, :bam]
+ *    a.select! {|element| element.to_s.start_with?('b') } # => ["bar", :bam]
+ *
+ *  Returns +nil+ if no elements were removed.
+ *
+ *  Returns a new \Enumerator if no block given:
+ *    a = [:foo, 'bar', 2, :bam]
+ *    a.select! # => #<Enumerator: [:foo, "bar", 2, :bam]:select!>
+ *
+ *  Array#filter! is an alias for Array#select!.
+ */
+
+static VALUE
+rb_ary_select_bang(VALUE ary)
 {
-    if (RARRAY(ary)->len <= 1) return ary;
+    struct select_bang_arg args;
 
+    RETURN_SIZED_ENUMERATOR(ary, 0, 0, ary_enum_length);
     rb_ary_modify(ary);
-    FL_SET(ary, ARY_TMPLOCK);	/* prohibit modification during sort */
-    rb_ensure(sort_internal, ary, sort_unlock, ary);
+
+    args.ary = ary;
+    args.len[0] = args.len[1] = 0;
+    return rb_ensure(select_bang_i, (VALUE)&args, select_bang_ensure, (VALUE)&args);
+}
+
+/*
+ *  call-seq:
+ *    array.keep_if {|element| ... } -> self
+ *    array.keep_if -> new_enumeration
+ *
+ *  Retains those elements for which the block returns a truthy value;
+ *  deletes all other elements; returns +self+:
+ *    a = [:foo, 'bar', 2, :bam]
+ *    a.keep_if {|element| element.to_s.start_with?('b') } # => ["bar", :bam]
+ *
+ *  Returns a new \Enumerator if no block given:
+ *    a = [:foo, 'bar', 2, :bam]
+ *    a.keep_if # => #<Enumerator: [:foo, "bar", 2, :bam]:keep_if>
+ */
+
+static VALUE
+rb_ary_keep_if(VALUE ary)
+{
+    RETURN_SIZED_ENUMERATOR(ary, 0, 0, ary_enum_length);
+    rb_ary_select_bang(ary);
     return ary;
 }
 
-VALUE
-rb_ary_sort(ary)
-    VALUE ary;
+static void
+ary_resize_smaller(VALUE ary, long len)
 {
-    if (RARRAY(ary)->len == 0) return ary;
-    return rb_ary_sort_bang(rb_ary_dup(ary));
+    rb_ary_modify(ary);
+    if (RARRAY_LEN(ary) > len) {
+	ARY_SET_LEN(ary, len);
+	if (len * 2 < ARY_CAPA(ary) &&
+	    ARY_CAPA(ary) > ARY_DEFAULT_SIZE) {
+	    ary_resize_capa(ary, len * 2);
+	}
+    }
 }
 
+/*
+ *  call-seq:
+ *    array.delete(obj) -> deleted_object
+ *    array.delete(obj) {|nosuch| ... } -> deleted_object or block_return
+ *
+ *  Removes zero or more elements from +self+; returns +self+.
+ *
+ *  When no block is given,
+ *  removes from +self+ each element +ele+ such that <tt>ele == obj</tt>;
+ *  returns the last deleted element:
+ *    s1 = 'bar'; s2 = 'bar'
+ *    a = [:foo, s1, 2, s2]
+ *    a.delete('bar') # => "bar"
+ *    a # => [:foo, 2]
+ *
+ *  Returns +nil+ if no elements removed.
+ *
+ *  When a block is given,
+ *  removes from +self+ each element +ele+ such that <tt>ele == obj</tt>.
+ *
+ *  If any such elements are found, ignores the block
+ *  and returns the last deleted element:
+ *    s1 = 'bar'; s2 = 'bar'
+ *    a = [:foo, s1, 2, s2]
+ *    deleted_obj = a.delete('bar') {|obj| fail 'Cannot happen' }
+ *    a # => [:foo, 2]
+ *
+ *  If no such elements are found, returns the block's return value:
+ *    a = [:foo, 'bar', 2]
+ *    a.delete(:nosuch) {|obj| "#{obj} not found" } # => "nosuch not found"
+ */
+
 VALUE
-rb_ary_delete(ary, item)
-    VALUE ary;
-    VALUE item;
+rb_ary_delete(VALUE ary, VALUE item)
 {
-    int i1, i2;
+    VALUE v = item;
+    long i1, i2;
 
-    rb_ary_modify(ary);
-    for (i1 = i2 = 0; i1 < RARRAY(ary)->len; i1++) {
-	if (rb_equal(RARRAY(ary)->ptr[i1], item)) continue;
+    for (i1 = i2 = 0; i1 < RARRAY_LEN(ary); i1++) {
+	VALUE e = RARRAY_AREF(ary, i1);
+
+	if (rb_equal(e, item)) {
+	    v = e;
+	    continue;
+	}
 	if (i1 != i2) {
-	    RARRAY(ary)->ptr[i2] = RARRAY(ary)->ptr[i1];
+	    rb_ary_store(ary, i2, e);
 	}
 	i2++;
     }
-    if (RARRAY(ary)->len == i2) {
-	if (rb_iterator_p()) {
+    if (RARRAY_LEN(ary) == i2) {
+	if (rb_block_given_p()) {
 	    return rb_yield(item);
 	}
 	return Qnil;
     }
-    else {
-	RARRAY(ary)->len = i2;
-    }
 
-    return item;
+    ary_resize_smaller(ary, i2);
+
+    ary_verify(ary);
+    return v;
 }
 
-VALUE
-rb_ary_delete_at(ary, at)
-    VALUE ary;
-    VALUE at;
+void
+rb_ary_delete_same(VALUE ary, VALUE item)
 {
-    int i1, i2, pos;
-    VALUE del = Qnil;
+    long i1, i2;
 
-    rb_ary_modify(ary);
-    pos = NUM2INT(at);
-    for (i1 = i2 = 0; i1 < RARRAY(ary)->len; i1++) {
-	if (i1 == pos) {
-	    del = RARRAY(ary)->ptr[i1];
+    for (i1 = i2 = 0; i1 < RARRAY_LEN(ary); i1++) {
+	VALUE e = RARRAY_AREF(ary, i1);
+
+	if (e == item) {
 	    continue;
 	}
 	if (i1 != i2) {
-	    RARRAY(ary)->ptr[i2] = RARRAY(ary)->ptr[i1];
+	    rb_ary_store(ary, i2, e);
 	}
 	i2++;
     }
-    RARRAY(ary)->len = i2;
+    if (RARRAY_LEN(ary) == i2) {
+	return;
+    }
+
+    ary_resize_smaller(ary, i2);
+}
 
+VALUE
+rb_ary_delete_at(VALUE ary, long pos)
+{
+    long len = RARRAY_LEN(ary);
+    VALUE del;
+
+    if (pos >= len) return Qnil;
+    if (pos < 0) {
+	pos += len;
+	if (pos < 0) return Qnil;
+    }
+
+    rb_ary_modify(ary);
+    del = RARRAY_AREF(ary, pos);
+    RARRAY_PTR_USE_TRANSIENT(ary, ptr, {
+        MEMMOVE(ptr+pos, ptr+pos+1, VALUE, len-pos-1);
+    });
+    ARY_INCREASE_LEN(ary, -1);
+    ary_verify(ary);
     return del;
 }
 
+/*
+ *  call-seq:
+ *    array.delete_at(index) -> deleted_object or nil
+ *
+ *  Deletes an element from +self+, per the given \Integer +index+.
+ *
+ *  When +index+ is non-negative, deletes the element at offset +index+:
+ *    a = [:foo, 'bar', 2]
+ *    a.delete_at(1) # => "bar"
+ *    a # => [:foo, 2]
+ *
+ *  If index is too large, returns +nil+.
+ *
+ *  When +index+ is negative, counts backward from the end of the array:
+ *    a = [:foo, 'bar', 2]
+ *    a.delete_at(-2) # => "bar"
+ *    a # => [:foo, 2]
+ *
+ *  If +index+ is too small (far from zero), returns nil.
+ */
+
 static VALUE
-rb_ary_delete_if(ary)
-    VALUE ary;
+rb_ary_delete_at_m(VALUE ary, VALUE pos)
 {
-    int i1, i2;
+    return rb_ary_delete_at(ary, NUM2LONG(pos));
+}
 
-    rb_ary_modify(ary);
-    for (i1 = i2 = 0; i1 < RARRAY(ary)->len; i1++) {
-	if (RTEST(rb_yield(RARRAY(ary)->ptr[i1]))) continue;
-	if (i1 != i2) {
-	    RARRAY(ary)->ptr[i2] = RARRAY(ary)->ptr[i1];
+static VALUE
+ary_slice_bang_by_rb_ary_splice(VALUE ary, long pos, long len)
+{
+    const long orig_len = RARRAY_LEN(ary);
+
+    if (len < 0) {
+        return Qnil;
+    }
+    else if (pos < -orig_len) {
+        return Qnil;
+    }
+    else if (pos < 0) {
+        pos += orig_len;
+    }
+    else if (orig_len < pos) {
+        return Qnil;
+    }
+    if (orig_len < pos + len) {
+        len = orig_len - pos;
+    }
+    if (len == 0) {
+        return rb_ary_new2(0);
+    }
+    else {
+        VALUE arg2 = rb_ary_new4(len, RARRAY_CONST_PTR_TRANSIENT(ary)+pos);
+        rb_ary_splice(ary, pos, len, 0, 0);
+        return arg2;
+    }
+}
+
+/*
+ *  call-seq:
+ *    array.slice!(n) -> object or nil
+ *    array.slice!(start, length) -> new_array or nil
+ *    array.slice!(range) -> new_array or nil
+ *
+ *  Removes and returns elements from +self+.
+ *
+ *  When the only argument is an \Integer +n+,
+ *  removes and returns the _nth_ element in +self+:
+ *    a = [:foo, 'bar', 2]
+ *    a.slice!(1) # => "bar"
+ *    a # => [:foo, 2]
+ *
+ *  If +n+ is negative, counts backwards from the end of +self+:
+ *    a = [:foo, 'bar', 2]
+ *    a.slice!(-1) # => 2
+ *    a # => [:foo, "bar"]
+ *
+ *  If +n+ is out of range, returns +nil+.
+ *
+ *  When the only arguments are Integers +start+ and +length+,
+ *  removes +length+ elements from +self+ beginning at offset  +start+;
+ *  returns the deleted objects in a new Array:
+ *    a = [:foo, 'bar', 2]
+ *    a.slice!(0, 2) # => [:foo, "bar"]
+ *    a # => [2]
+ *
+ *  If <tt>start + length</tt> exceeds the array size,
+ *  removes and returns all elements from offset +start+ to the end:
+ *    a = [:foo, 'bar', 2]
+ *    a.slice!(1, 50) # => ["bar", 2]
+ *    a # => [:foo]
+ *
+ *  If <tt>start == a.size</tt> and +length+ is non-negative,
+ *  returns a new empty \Array.
+ *
+ *  If +length+ is negative, returns +nil+.
+ *
+ *  When the only argument is a \Range object +range+,
+ *  treats <tt>range.min</tt> as +start+ above and <tt>range.size</tt> as +length+ above:
+ *    a = [:foo, 'bar', 2]
+ *     a.slice!(1..2) # => ["bar", 2]
+ *    a # => [:foo]
+ *
+ *  If <tt>range.start == a.size</tt>, returns a new empty \Array.
+ *
+ *  If <tt>range.start</tt> is larger than the array size, returns +nil+.
+ *
+ *  If <tt>range.end</tt> is negative, counts backwards from the end of the array:
+ *    a = [:foo, 'bar', 2]
+ *    a.slice!(0..-2) # => [:foo, "bar"]
+ *    a # => [2]
+ *
+ *  If <tt>range.start</tt> is negative,
+ *  calculates the start index backwards from the end of the array:
+ *    a = [:foo, 'bar', 2]
+ *    a.slice!(-2..2) # => ["bar", 2]
+ *    a # => [:foo]
+ */
+
+static VALUE
+rb_ary_slice_bang(int argc, VALUE *argv, VALUE ary)
+{
+    VALUE arg1;
+    long pos, len;
+
+    rb_ary_modify_check(ary);
+    rb_check_arity(argc, 1, 2);
+    arg1 = argv[0];
+
+    if (argc == 2) {
+	pos = NUM2LONG(argv[0]);
+	len = NUM2LONG(argv[1]);
+        return ary_slice_bang_by_rb_ary_splice(ary, pos, len);
+    }
+
+    if (!FIXNUM_P(arg1)) {
+	switch (rb_range_beg_len(arg1, &pos, &len, RARRAY_LEN(ary), 0)) {
+	  case Qtrue:
+	    /* valid range */
+            return ary_slice_bang_by_rb_ary_splice(ary, pos, len);
+	  case Qnil:
+	    /* invalid range */
+	    return Qnil;
+	  default:
+	    /* not a range */
+	    break;
 	}
-	i2++;
     }
-    RARRAY(ary)->len = i2;
 
-    return ary;
+    return rb_ary_delete_at(ary, NUM2LONG(arg1));
 }
 
 static VALUE
-rb_ary_filter(ary)
-    VALUE ary;
+ary_reject(VALUE orig, VALUE result)
 {
-    int i;
+    long i;
 
-    rb_ary_modify(ary);
-    for (i = 0; i < RARRAY(ary)->len; i++) {
-	RARRAY(ary)->ptr[i] = rb_yield(RARRAY(ary)->ptr[i]);
+    for (i = 0; i < RARRAY_LEN(orig); i++) {
+	VALUE v = RARRAY_AREF(orig, i);
+
+        if (!RTEST(rb_yield(v))) {
+	    rb_ary_push(result, v);
+	}
     }
-    return ary;
+    return result;
 }
 
 static VALUE
-rb_ary_replace_method(ary, ary2)
-    VALUE ary, ary2;
+reject_bang_i(VALUE a)
 {
-    ary2 = to_ary(ary2);
-    rb_ary_replace(ary, 0, RARRAY(ary2)->len, ary2);
+    volatile struct select_bang_arg *arg = (void *)a;
+    VALUE ary = arg->ary;
+    long i1, i2;
+
+    for (i1 = i2 = 0; i1 < RARRAY_LEN(ary); arg->len[0] = ++i1) {
+	VALUE v = RARRAY_AREF(ary, i1);
+	if (RTEST(rb_yield(v))) continue;
+	if (i1 != i2) {
+	    rb_ary_store(ary, i2, v);
+	}
+	arg->len[1] = ++i2;
+    }
+    return (i1 == i2) ? Qnil : ary;
+}
+
+static VALUE
+ary_reject_bang(VALUE ary)
+{
+    struct select_bang_arg args;
+    rb_ary_modify_check(ary);
+    args.ary = ary;
+    args.len[0] = args.len[1] = 0;
+    return rb_ensure(reject_bang_i, (VALUE)&args, select_bang_ensure, (VALUE)&args);
+}
+
+/*
+ *  call-seq:
+ *    array.reject! {|element| ... } -> self or nil
+ *    array.reject! -> new_enumerator
+ *
+ *  Removes each element for which the block returns a truthy value.
+ *
+ *  Returns +self+ if any elements removed:
+ *    a = [:foo, 'bar', 2, 'bat']
+ *    a.reject! {|element| element.to_s.start_with?('b') } # => [:foo, 2]
+ *
+ *  Returns +nil+ if no elements removed.
+ *
+ *  Returns a new \Enumerator if no block given:
+ *    a = [:foo, 'bar', 2]
+ *    a.reject! # => #<Enumerator: [:foo, "bar", 2]:reject!>
+ */
+
+static VALUE
+rb_ary_reject_bang(VALUE ary)
+{
+    RETURN_SIZED_ENUMERATOR(ary, 0, 0, ary_enum_length);
+    rb_ary_modify(ary);
+    return ary_reject_bang(ary);
+}
+
+/*
+ *  call-seq:
+ *    array.reject {|element| ... } -> new_array
+ *    array.reject -> new_enumerator
+ *
+ *  Returns a new \Array whose elements are all those from +self+
+ *  for which the block returns +false+ or +nil+:
+ *    a = [:foo, 'bar', 2, 'bat']
+ *    a1 = a.reject {|element| element.to_s.start_with?('b') }
+ *    a1 # => [:foo, 2]
+ *
+ *  Returns a new \Enumerator if no block given:
+ *     a = [:foo, 'bar', 2]
+ *     a.reject # => #<Enumerator: [:foo, "bar", 2]:reject>
+ */
+
+static VALUE
+rb_ary_reject(VALUE ary)
+{
+    VALUE rejected_ary;
+
+    RETURN_SIZED_ENUMERATOR(ary, 0, 0, ary_enum_length);
+    rejected_ary = rb_ary_new();
+    ary_reject(ary, rejected_ary);
+    return rejected_ary;
+}
+
+/*
+ *  call-seq:
+ *    array.delete_if {|element| ... } -> self
+ *    array.delete_if -> Enumerator
+ *
+ *  Removes each element in +self+ for which the block returns a truthy value;
+ *  returns +self+:
+ *    a = [:foo, 'bar', 2, 'bat']
+ *    a.delete_if {|element| element.to_s.start_with?('b') } # => [:foo, 2]
+ *
+ *  Returns a new \Enumerator if no block given:
+ *    a = [:foo, 'bar', 2]
+ *    a.delete_if # => #<Enumerator: [:foo, "bar", 2]:delete_if>
+ */
+
+static VALUE
+rb_ary_delete_if(VALUE ary)
+{
+    ary_verify(ary);
+    RETURN_SIZED_ENUMERATOR(ary, 0, 0, ary_enum_length);
+    ary_reject_bang(ary);
     return ary;
 }
 
 static VALUE
-rb_ary_clear(ary)
-    VALUE ary;
+take_i(RB_BLOCK_CALL_FUNC_ARGLIST(val, cbarg))
+{
+    VALUE *args = (VALUE *)cbarg;
+    if (args[1] == 0) rb_iter_break();
+    else args[1]--;
+    if (argc > 1) val = rb_ary_new4(argc, argv);
+    rb_ary_push(args[0], val);
+    return Qnil;
+}
+
+static VALUE
+take_items(VALUE obj, long n)
+{
+    VALUE result = rb_check_array_type(obj);
+    VALUE args[2];
+
+    if (!NIL_P(result)) return rb_ary_subseq(result, 0, n);
+    result = rb_ary_new2(n);
+    args[0] = result; args[1] = (VALUE)n;
+    if (rb_check_block_call(obj, idEach, 0, 0, take_i, (VALUE)args) == Qundef)
+	rb_raise(rb_eTypeError, "wrong argument type %"PRIsVALUE" (must respond to :each)",
+		 rb_obj_class(obj));
+    return result;
+}
+
+
+/*
+ *  call-seq:
+ *    array.zip(*other_arrays) -> new_array
+ *    array.zip(*other_arrays) {|other_array| ... } -> nil
+ *
+ *  When no block given, returns a new \Array +new_array+ of size <tt>self.size</tt>
+ *  whose elements are Arrays.
+ *
+ *  Each nested array <tt>new_array[n]</tt> is of size <tt>other_arrays.size+1</tt>,
+ *  and contains:
+ *  - The _nth_ element of +self+.
+ *  - The _nth_ element of each of the +other_arrays+.
+ *
+ *  If all +other_arrays+ and +self+ are the same size:
+ *    a = [:a0, :a1, :a2, :a3]
+ *    b = [:b0, :b1, :b2, :b3]
+ *    c = [:c0, :c1, :c2, :c3]
+ *    d = a.zip(b, c)
+ *    d # => [[:a0, :b0, :c0], [:a1, :b1, :c1], [:a2, :b2, :c2], [:a3, :b3, :c3]]
+ *
+ *  If any array in +other_arrays+ is smaller than +self+,
+ *  fills to <tt>self.size</tt> with +nil+:
+ *    a = [:a0, :a1, :a2, :a3]
+ *    b = [:b0, :b1, :b2]
+ *    c = [:c0, :c1]
+ *    d = a.zip(b, c)
+ *    d # => [[:a0, :b0, :c0], [:a1, :b1, :c1], [:a2, :b2, nil], [:a3, nil, nil]]
+ *
+ *  If any array in +other_arrays+ is larger than +self+,
+ *  its trailing elements are ignored:
+ *    a = [:a0, :a1, :a2, :a3]
+ *    b = [:b0, :b1, :b2, :b3, :b4]
+ *    c = [:c0, :c1, :c2, :c3, :c4, :c5]
+ *    d = a.zip(b, c)
+ *    d # => [[:a0, :b0, :c0], [:a1, :b1, :c1], [:a2, :b2, :c2], [:a3, :b3, :c3]]
+ *
+ *  When a block is given, calls the block with each of the sub-arrays (formed as above); returns nil
+ *    a = [:a0, :a1, :a2, :a3]
+ *    b = [:b0, :b1, :b2, :b3]
+ *    c = [:c0, :c1, :c2, :c3]
+ *    a.zip(b, c) {|sub_array| p sub_array} # => nil
+ *
+ *  Output:
+ *    [:a0, :b0, :c0]
+ *    [:a1, :b1, :c1]
+ *    [:a2, :b2, :c2]
+ *    [:a3, :b3, :c3]
+ */
+
+static VALUE
+rb_ary_zip(int argc, VALUE *argv, VALUE ary)
+{
+    int i, j;
+    long len = RARRAY_LEN(ary);
+    VALUE result = Qnil;
+
+    for (i=0; i<argc; i++) {
+	argv[i] = take_items(argv[i], len);
+    }
+
+    if (rb_block_given_p()) {
+	int arity = rb_block_arity();
+
+	if (arity > 1) {
+	    VALUE work, *tmp;
+
+	    tmp = ALLOCV_N(VALUE, work, argc+1);
+
+	    for (i=0; i<RARRAY_LEN(ary); i++) {
+		tmp[0] = RARRAY_AREF(ary, i);
+		for (j=0; j<argc; j++) {
+		    tmp[j+1] = rb_ary_elt(argv[j], i);
+		}
+		rb_yield_values2(argc+1, tmp);
+	    }
+
+	    if (work) ALLOCV_END(work);
+	}
+	else {
+	    for (i=0; i<RARRAY_LEN(ary); i++) {
+		VALUE tmp = rb_ary_new2(argc+1);
+
+		rb_ary_push(tmp, RARRAY_AREF(ary, i));
+		for (j=0; j<argc; j++) {
+		    rb_ary_push(tmp, rb_ary_elt(argv[j], i));
+		}
+		rb_yield(tmp);
+	    }
+	}
+    }
+    else {
+	result = rb_ary_new_capa(len);
+
+	for (i=0; i<len; i++) {
+	    VALUE tmp = rb_ary_new_capa(argc+1);
+
+	    rb_ary_push(tmp, RARRAY_AREF(ary, i));
+	    for (j=0; j<argc; j++) {
+		rb_ary_push(tmp, rb_ary_elt(argv[j], i));
+	    }
+	    rb_ary_push(result, tmp);
+	}
+    }
+
+    return result;
+}
+
+/*
+ *  call-seq:
+ *    array.transpose -> new_array
+ *
+ *  Transposes the rows and columns in an \Array of Arrays;
+ *  the nested Arrays must all be the same size:
+ *    a = [[:a0, :a1], [:b0, :b1], [:c0, :c1]]
+ *    a.transpose # => [[:a0, :b0, :c0], [:a1, :b1, :c1]]
+ */
+
+static VALUE
+rb_ary_transpose(VALUE ary)
 {
-    RARRAY(ary)->len = 0;
-    if (ARY_DEFAULT_SIZE*3 < RARRAY(ary)->capa) {
-	RARRAY(ary)->capa = ARY_DEFAULT_SIZE * 2;
-	REALLOC_N(RARRAY(ary)->ptr, VALUE, RARRAY(ary)->capa);
+    long elen = -1, alen, i, j;
+    VALUE tmp, result = 0;
+
+    alen = RARRAY_LEN(ary);
+    if (alen == 0) return rb_ary_dup(ary);
+    for (i=0; i<alen; i++) {
+	tmp = to_ary(rb_ary_elt(ary, i));
+	if (elen < 0) {		/* first element */
+	    elen = RARRAY_LEN(tmp);
+	    result = rb_ary_new2(elen);
+	    for (j=0; j<elen; j++) {
+		rb_ary_store(result, j, rb_ary_new2(alen));
+	    }
+	}
+	else if (elen != RARRAY_LEN(tmp)) {
+	    rb_raise(rb_eIndexError, "element size differs (%ld should be %ld)",
+		     RARRAY_LEN(tmp), elen);
+	}
+	for (j=0; j<elen; j++) {
+	    rb_ary_store(rb_ary_elt(result, j), i, rb_ary_elt(tmp, j));
+	}
+    }
+    return result;
+}
+
+/*
+ *  call-seq:
+ *    array.replace(other_array) -> self
+ *
+ *  Replaces the content of +self+ with the content of +other_array+; returns +self+:
+ *    a = [:foo, 'bar', 2]
+ *    a.replace(['foo', :bar, 3]) # => ["foo", :bar, 3]
+ */
+
+VALUE
+rb_ary_replace(VALUE copy, VALUE orig)
+{
+    rb_ary_modify_check(copy);
+    orig = to_ary(orig);
+    if (copy == orig) return copy;
+
+    if (RARRAY_LEN(orig) <= RARRAY_EMBED_LEN_MAX) {
+        VALUE shared_root = 0;
+
+        if (ARY_OWNS_HEAP_P(copy)) {
+            ary_heap_free(copy);
+	}
+        else if (ARY_SHARED_P(copy)) {
+            shared_root = ARY_SHARED_ROOT(copy);
+            FL_UNSET_SHARED(copy);
+        }
+        FL_SET_EMBED(copy);
+        ary_memcpy(copy, 0, RARRAY_LEN(orig), RARRAY_CONST_PTR_TRANSIENT(orig));
+        if (shared_root) {
+            rb_ary_decrement_share(shared_root);
+        }
+        ARY_SET_LEN(copy, RARRAY_LEN(orig));
     }
+    else {
+        VALUE shared_root = ary_make_shared(orig);
+        if (ARY_OWNS_HEAP_P(copy)) {
+            ary_heap_free(copy);
+        }
+        else {
+            rb_ary_unshare_safe(copy);
+        }
+        FL_UNSET_EMBED(copy);
+        ARY_SET_PTR(copy, ARY_HEAP_PTR(orig));
+        ARY_SET_LEN(copy, ARY_HEAP_LEN(orig));
+        rb_ary_set_shared(copy, shared_root);
+    }
+    ary_verify(copy);
+    return copy;
+}
+
+/*
+ *  call-seq:
+ *     array.clear -> self
+ *
+ *  Removes all elements from +self+:
+ *    a = [:foo, 'bar', 2]
+ *    a.clear # => []
+ */
+
+VALUE
+rb_ary_clear(VALUE ary)
+{
+    rb_ary_modify_check(ary);
+    if (ARY_SHARED_P(ary)) {
+	if (!ARY_EMBED_P(ary)) {
+	    rb_ary_unshare(ary);
+	    FL_SET_EMBED(ary);
+            ARY_SET_EMBED_LEN(ary, 0);
+	}
+    }
+    else {
+        ARY_SET_LEN(ary, 0);
+        if (ARY_DEFAULT_SIZE * 2 < ARY_CAPA(ary)) {
+            ary_resize_capa(ary, ARY_DEFAULT_SIZE * 2);
+        }
+    }
+    ary_verify(ary);
     return ary;
 }
 
+/*
+ *  call-seq:
+ *    array.fill(obj) -> self
+ *    array.fill(obj, start) -> self
+ *    array.fill(obj, start, length) -> self
+ *    array.fill(obj, range) -> self
+ *    array.fill {|index| ... } -> self
+ *    array.fill(start) {|index| ... } -> self
+ *    array.fill(start, length) {|index| ... } -> self
+ *    array.fill(range) {|index| ... } -> self
+ *
+ *  Replaces specified elements in +self+ with specified objects; returns +self+.
+ *
+ *  With argument +obj+ and no block given, replaces all elements with that one object:
+ *    a = ['a', 'b', 'c', 'd']
+ *    a # => ["a", "b", "c", "d"]
+ *    a.fill(:X) # => [:X, :X, :X, :X]
+ *
+ *  With arguments +obj+ and \Integer +start+, and no block given,
+ *  replaces elements based on the given start.
+ *
+ *  If +start+ is in range (<tt>0 <= start < array.size</tt>),
+ *  replaces all elements from offset +start+ through the end:
+ *    a = ['a', 'b', 'c', 'd']
+ *    a.fill(:X, 2) # => ["a", "b", :X, :X]
+ *
+ *  If +start+ is too large (<tt>start >= array.size</tt>), does nothing:
+ *    a = ['a', 'b', 'c', 'd']
+ *    a.fill(:X, 4) # => ["a", "b", "c", "d"]
+ *    a = ['a', 'b', 'c', 'd']
+ *    a.fill(:X, 5) # => ["a", "b", "c", "d"]
+ *
+ *  If +start+ is negative, counts from the end (starting index is <tt>start + array.size</tt>):
+ *    a = ['a', 'b', 'c', 'd']
+ *    a.fill(:X, -2) # => ["a", "b", :X, :X]
+ *
+ *  If +start+ is too small (less than and far from zero), replaces all elements:
+ *    a = ['a', 'b', 'c', 'd']
+ *    a.fill(:X, -6) # => [:X, :X, :X, :X]
+ *    a = ['a', 'b', 'c', 'd']
+ *    a.fill(:X, -50) # => [:X, :X, :X, :X]
+ *
+ *  With arguments +obj+, \Integer +start+, and \Integer +length+, and no block given,
+ *  replaces elements based on the given +start+ and +length+.
+ *
+ *  If +start+ is in range, replaces +length+ elements beginning at offset +start+:
+ *    a = ['a', 'b', 'c', 'd']
+ *    a.fill(:X, 1, 1) # => ["a", :X, "c", "d"]
+ *
+ *  If +start+ is negative, counts from the end:
+ *    a = ['a', 'b', 'c', 'd']
+ *    a.fill(:X, -2, 1) # => ["a", "b", :X, "d"]
+ *
+ *  If +start+ is large (<tt>start >= array.size</tt>), extends +self+ with +nil+:
+ *    a = ['a', 'b', 'c', 'd']
+ *    a.fill(:X, 5, 0) # => ["a", "b", "c", "d", nil]
+ *    a = ['a', 'b', 'c', 'd']
+ *    a.fill(:X, 5, 2) # => ["a", "b", "c", "d", nil, :X, :X]
+ *
+ *  If +length+ is zero or negative, replaces no elements:
+ *    a = ['a', 'b', 'c', 'd']
+ *    a.fill(:X, 1, 0) # => ["a", "b", "c", "d"]
+ *    a.fill(:X, 1, -1) # => ["a", "b", "c", "d"]
+ *
+ *  With arguments +obj+ and \Range +range+, and no block given,
+ *  replaces elements based on the given range.
+ *
+ *  If the range is positive and ascending (<tt>0 < range.begin <= range.end</tt>),
+ *  replaces elements from <tt>range.begin</tt> to <tt>range.end</tt>:
+ *    a = ['a', 'b', 'c', 'd']
+ *    a.fill(:X, (1..1)) # => ["a", :X, "c", "d"]
+ *
+ *  If <tt>range.first</tt> is negative, replaces no elements:
+ *    a = ['a', 'b', 'c', 'd']
+ *    a.fill(:X, (-1..1)) # => ["a", "b", "c", "d"]
+ *
+ *  If <tt>range.last</tt> is negative, counts from the end:
+ *    a = ['a', 'b', 'c', 'd']
+ *    a.fill(:X, (0..-2)) # => [:X, :X, :X, "d"]
+ *    a = ['a', 'b', 'c', 'd']
+ *    a.fill(:X, (1..-2)) # => ["a", :X, :X, "d"]
+ *
+ *  If <tt>range.last</tt> and <tt>range.last</tt> are both negative,
+ *  both count from the end of the array:
+ *    a = ['a', 'b', 'c', 'd']
+ *    a.fill(:X, (-1..-1)) # => ["a", "b", "c", :X]
+ *    a = ['a', 'b', 'c', 'd']
+ *    a.fill(:X, (-2..-2)) # => ["a", "b", :X, "d"]
+ *
+ *  With no arguments and a block given, calls the block with each index;
+ *  replaces the corresponding element with the block's return value:
+ *    a = ['a', 'b', 'c', 'd']
+ *    a.fill { |index| "new_#{index}" } # => ["new_0", "new_1", "new_2", "new_3"]
+ *
+ *  With argument +start+ and a block given, calls the block with each index
+ *  from offset +start+ to the end; replaces the corresponding element
+ *  with the block's return value:
+ *
+ *  If start is in range (<tt>0 <= start < array.size</tt>),
+ *  replaces from offset +start+ to the end:
+ *    a = ['a', 'b', 'c', 'd']
+ *    a.fill(1) { |index| "new_#{index}" } # => ["a", "new_1", "new_2", "new_3"]
+ *
+ *  If +start+ is too large(<tt>start >= array.size</tt>), does nothing:
+ *    a = ['a', 'b', 'c', 'd']
+ *    a.fill(4) { |index| fail 'Cannot happen' } # => ["a", "b", "c", "d"]
+ *    a = ['a', 'b', 'c', 'd']
+ *    a.fill(4) { |index| fail 'Cannot happen' } # => ["a", "b", "c", "d"]
+ *
+ *  If +start+ is negative, counts from the end:
+ *    a = ['a', 'b', 'c', 'd']
+ *    a.fill(-2) { |index| "new_#{index}" } # => ["a", "b", "new_2", "new_3"]
+ *
+ *  If start is too small (<tt>start <= -array.size</tt>, replaces all elements:
+ *    a = ['a', 'b', 'c', 'd']
+ *    a.fill(-6) { |index| "new_#{index}" } # => ["new_0", "new_1", "new_2", "new_3"]
+ *    a = ['a', 'b', 'c', 'd']
+ *    a.fill(-50) { |index| "new_#{index}" } # => ["new_0", "new_1", "new_2", "new_3"]
+ *
+ *  With arguments +start+ and +length+, and a block given,
+ *  calls the block for each index specified by start length;
+ *  replaces the corresponding element with the block's return value.
+ *
+ *  If +start+ is in range, replaces +length+ elements beginning at offset +start+:
+ *    a = ['a', 'b', 'c', 'd']
+ *    a.fill(1, 1) { |index| "new_#{index}" } # => ["a", "new_1", "c", "d"]
+ *
+ *  If start is negative, counts from the end:
+ *    a = ['a', 'b', 'c', 'd']
+ *    a.fill(-2, 1) { |index| "new_#{index}" } # => ["a", "b", "new_2", "d"]
+ *
+ *  If +start+ is large (<tt>start >= array.size</tt>), extends +self+ with +nil+:
+ *    a = ['a', 'b', 'c', 'd']
+ *    a.fill(5, 0) { |index| "new_#{index}" } # => ["a", "b", "c", "d", nil]
+ *    a = ['a', 'b', 'c', 'd']
+ *    a.fill(5, 2) { |index| "new_#{index}" } # => ["a", "b", "c", "d", nil, "new_5", "new_6"]
+ *
+ *  If +length+ is zero or less, replaces no elements:
+ *    a = ['a', 'b', 'c', 'd']
+ *    a.fill(1, 0) { |index| "new_#{index}" } # => ["a", "b", "c", "d"]
+ *    a.fill(1, -1) { |index| "new_#{index}" } # => ["a", "b", "c", "d"]
+ *
+ *  With arguments +obj+ and +range+, and a block given,
+ *  calls the block with each index in the given range;
+ *  replaces the corresponding element with the block's return value.
+ *
+ *  If the range is positive and ascending (<tt>range 0 < range.begin <= range.end</tt>,
+ *  replaces elements from <tt>range.begin</tt> to <tt>range.end</tt>:
+ *    a = ['a', 'b', 'c', 'd']
+ *    a.fill(1..1) { |index| "new_#{index}" } # => ["a", "new_1", "c", "d"]
+ *
+ *  If +range.first+ is negative, does nothing:
+ *    a = ['a', 'b', 'c', 'd']
+ *    a.fill(-1..1) { |index| fail 'Cannot happen' } # => ["a", "b", "c", "d"]
+ *
+ *  If <tt>range.last</tt> is negative, counts from the end:
+ *    a = ['a', 'b', 'c', 'd']
+ *    a.fill(0..-2) { |index| "new_#{index}" } # => ["new_0", "new_1", "new_2", "d"]
+ *    a = ['a', 'b', 'c', 'd']
+ *    a.fill(1..-2) { |index| "new_#{index}" } # => ["a", "new_1", "new_2", "d"]
+ *
+ *  If <tt>range.first</tt> and <tt>range.last</tt> are both negative,
+ *  both count from the end:
+ *    a = ['a', 'b', 'c', 'd']
+ *    a.fill(-1..-1) { |index| "new_#{index}" } # => ["a", "b", "c", "new_3"]
+ *    a = ['a', 'b', 'c', 'd']
+ *    a.fill(-2..-2) { |index| "new_#{index}" } # => ["a", "b", "new_2", "d"]
+ */
+
 static VALUE
-rb_ary_fill(argc, argv, ary)
-    int argc;
-    VALUE *argv;
-    VALUE ary;
+rb_ary_fill(int argc, VALUE *argv, VALUE ary)
 {
-    VALUE item, arg1, arg2;
-    int beg, end, len;
-    VALUE *p, *pend;
+    VALUE item = Qundef, arg1, arg2;
+    long beg = 0, end = 0, len = 0;
 
-    if (rb_scan_args(argc, argv, "12", &item, &arg1, &arg2) == 2 &&
-	beg_len(arg1, &beg, &len, RARRAY(ary)->len)) {
-	/* beg and len set already */
+    if (rb_block_given_p()) {
+	rb_scan_args(argc, argv, "02", &arg1, &arg2);
+	argc += 1;		/* hackish */
     }
     else {
-	beg = NIL_P(arg1)?0:NUM2INT(arg1);
+	rb_scan_args(argc, argv, "12", &item, &arg1, &arg2);
+    }
+    switch (argc) {
+      case 1:
+	beg = 0;
+	len = RARRAY_LEN(ary);
+	break;
+      case 2:
+	if (rb_range_beg_len(arg1, &beg, &len, RARRAY_LEN(ary), 1)) {
+	    break;
+	}
+	/* fall through */
+      case 3:
+	beg = NIL_P(arg1) ? 0 : NUM2LONG(arg1);
 	if (beg < 0) {
-	    beg = RARRAY(ary)->len + beg;
+	    beg = RARRAY_LEN(ary) + beg;
 	    if (beg < 0) beg = 0;
 	}
-	len = NIL_P(arg2)?RARRAY(ary)->len - beg:NUM2INT(arg2);
+	len = NIL_P(arg2) ? RARRAY_LEN(ary) - beg : NUM2LONG(arg2);
+	break;
     }
     rb_ary_modify(ary);
+    if (len < 0) {
+        return ary;
+    }
+    if (beg >= ARY_MAX_SIZE || len > ARY_MAX_SIZE - beg) {
+	rb_raise(rb_eArgError, "argument too big");
+    }
     end = beg + len;
-    if (end > RARRAY(ary)->len) {
-	if (end >= RARRAY(ary)->capa) {
-	    RARRAY(ary)->capa=end;
-	    REALLOC_N(RARRAY(ary)->ptr, VALUE, RARRAY(ary)->capa);
-	}
-	if (beg > RARRAY(ary)->len) {
-	    rb_mem_clear(RARRAY(ary)->ptr+RARRAY(ary)->len,end-RARRAY(ary)->len);
+    if (RARRAY_LEN(ary) < end) {
+	if (end >= ARY_CAPA(ary)) {
+	    ary_resize_capa(ary, end);
 	}
-	RARRAY(ary)->len = end;
+	ary_mem_clear(ary, RARRAY_LEN(ary), end - RARRAY_LEN(ary));
+	ARY_SET_LEN(ary, end);
     }
-    p = RARRAY(ary)->ptr + beg; pend = p + len;
 
-    while (p < pend) {
-	*p++ = item;
+    if (item == Qundef) {
+	VALUE v;
+	long i;
+
+	for (i=beg; i<end; i++) {
+	    v = rb_yield(LONG2NUM(i));
+	    if (i>=RARRAY_LEN(ary)) break;
+	    ARY_SET(ary, i, v);
+	}
+    }
+    else {
+	ary_memfill(ary, beg, len, item);
     }
     return ary;
 }
 
+/*
+ *  call-seq:
+ *    array + other_array -> new_array
+ *
+ *  Returns a new \Array containing all elements of +array+
+ *  followed by all elements of +other_array+:
+ *    a = [0, 1] + [2, 3]
+ *    a # => [0, 1, 2, 3]
+ *
+ *  Related: #concat.
+ */
+
 VALUE
-rb_ary_plus(x, y)
-    VALUE x, y;
+rb_ary_plus(VALUE x, VALUE y)
 {
     VALUE z;
+    long len, xlen, ylen;
 
-    if (TYPE(y) != T_ARRAY) {
-	return rb_ary_plus(x, rb_Array(y));
-    }
+    y = to_ary(y);
+    xlen = RARRAY_LEN(x);
+    ylen = RARRAY_LEN(y);
+    len = xlen + ylen;
+    z = rb_ary_new2(len);
 
-    z = rb_ary_new2(RARRAY(x)->len + RARRAY(y)->len);
-    MEMCPY(RARRAY(z)->ptr, RARRAY(x)->ptr, VALUE, RARRAY(x)->len);
-    MEMCPY(RARRAY(z)->ptr+RARRAY(x)->len, RARRAY(y)->ptr, VALUE, RARRAY(y)->len);
-    RARRAY(z)->len = RARRAY(x)->len + RARRAY(y)->len;
+    ary_memcpy(z, 0, xlen, RARRAY_CONST_PTR_TRANSIENT(x));
+    ary_memcpy(z, xlen, ylen, RARRAY_CONST_PTR_TRANSIENT(y));
+    ARY_SET_LEN(z, len);
     return z;
 }
 
-VALUE
-rb_ary_concat(x, y)
-    VALUE x, y;
+static VALUE
+ary_append(VALUE x, VALUE y)
 {
-    VALUE *p, *pend;
-
-    if (TYPE(y) != T_ARRAY) {
-	return rb_ary_concat(x, rb_Array(y));
+    long n = RARRAY_LEN(y);
+    if (n > 0) {
+        rb_ary_splice(x, RARRAY_LEN(x), 0, RARRAY_CONST_PTR_TRANSIENT(y), n);
     }
+    RB_GC_GUARD(y);
+    return x;
+}
+
+/*
+ *  call-seq:
+ *    array.concat(*other_arrays) -> self
+ *
+ *  Adds to +array+ all elements from each \Array in +other_arrays+; returns +self+:
+ *    a = [0, 1]
+ *    a.concat([2, 3], [4, 5]) # => [0, 1, 2, 3, 4, 5]
+ */
 
-    p = RARRAY(y)->ptr;
-    pend = p + RARRAY(y)->len;
-    while (p < pend) {
-	rb_ary_store(x, RARRAY(x)->len, *p);
-	p++;
+static VALUE
+rb_ary_concat_multi(int argc, VALUE *argv, VALUE ary)
+{
+    rb_ary_modify_check(ary);
+
+    if (argc == 1) {
+	rb_ary_concat(ary, argv[0]);
     }
-    return x;
+    else if (argc > 1) {
+	int i;
+	VALUE args = rb_ary_tmp_new(argc);
+	for (i = 0; i < argc; i++) {
+	    rb_ary_concat(args, argv[i]);
+	}
+	ary_append(ary, args);
+    }
+
+    ary_verify(ary);
+    return ary;
+}
+
+VALUE
+rb_ary_concat(VALUE x, VALUE y)
+{
+    return ary_append(x, to_ary(y));
 }
 
+/*
+ *  call-seq:
+ *    array * n -> new_array
+ *    array * string_separator -> new_string
+ *
+ *  When non-negative argument \Integer +n+ is given,
+ *  returns a new \Array built by concatenating the +n+ copies of +self+:
+ *    a = ['x', 'y']
+ *    a * 3 # => ["x", "y", "x", "y", "x", "y"]
+ *
+ *  When \String argument +string_separator+ is given,
+ *  equivalent to <tt>array.join(string_separator)</tt>:
+ *    [0, [0, 1], {foo: 0}] * ', ' # => "0, 0, 1, {:foo=>0}"
+ */
+
 static VALUE
-rb_ary_times(ary, times)
-    VALUE ary;
-    VALUE times;
+rb_ary_times(VALUE ary, VALUE times)
 {
-    VALUE ary2;
-    int i, len;
+    VALUE ary2, tmp;
+    const VALUE *ptr;
+    long t, len;
 
-    if (TYPE(times) == T_STRING) {
-	return rb_ary_join(ary, times);
+    tmp = rb_check_string_type(times);
+    if (!NIL_P(tmp)) {
+	return rb_ary_join(ary, tmp);
     }
 
-    len = NUM2INT(times);
+    len = NUM2LONG(times);
+    if (len == 0) {
+        ary2 = ary_new(rb_cArray, 0);
+	goto out;
+    }
     if (len < 0) {
 	rb_raise(rb_eArgError, "negative argument");
     }
-    len *= RARRAY(ary)->len;
-
-    ary2 = rb_ary_new2(len);
-    RARRAY(ary2)->len = len;
-
-    for (i=0; i<len; i+=RARRAY(ary)->len) {
-	MEMCPY(RARRAY(ary2)->ptr+i, RARRAY(ary)->ptr, VALUE, RARRAY(ary)->len);
+    if (ARY_MAX_SIZE/len < RARRAY_LEN(ary)) {
+	rb_raise(rb_eArgError, "argument too big");
     }
-
+    len *= RARRAY_LEN(ary);
+
+    ary2 = ary_new(rb_cArray, len);
+    ARY_SET_LEN(ary2, len);
+
+    ptr = RARRAY_CONST_PTR_TRANSIENT(ary);
+    t = RARRAY_LEN(ary);
+    if (0 < t) {
+	ary_memcpy(ary2, 0, t, ptr);
+	while (t <= len/2) {
+            ary_memcpy(ary2, t, t, RARRAY_CONST_PTR_TRANSIENT(ary2));
+            t *= 2;
+        }
+        if (t < len) {
+            ary_memcpy(ary2, t, len-t, RARRAY_CONST_PTR_TRANSIENT(ary2));
+        }
+    }
+  out:
     return ary2;
 }
 
+/*
+ *  call-seq:
+ *    array.assoc(obj) -> found_array or nil
+ *
+ *  Returns the first element in +self+ that is an \Array
+ *  whose first element <tt>==</tt> +obj+:
+ *    a = [{foo: 0}, [2, 4], [4, 5, 6], [4, 5]]
+ *    a.assoc(4) # => [4, 5, 6]
+ *
+ *  Returns +nil+ if no such element is found.
+ *
+ *  Related: #rassoc.
+ */
+
 VALUE
-rb_ary_assoc(ary, key)
-    VALUE ary;
-    VALUE key;
+rb_ary_assoc(VALUE ary, VALUE key)
 {
-    VALUE *p, *pend;
+    long i;
+    VALUE v;
 
-    p = RARRAY(ary)->ptr; pend = p + RARRAY(ary)->len;
-    while (p < pend) {
-	if (TYPE(*p) == T_ARRAY
-	    && RARRAY(*p)->len > 1
-	    && rb_equal(RARRAY(*p)->ptr[0], key))
-	    return *p;
-	p++;
+    for (i = 0; i < RARRAY_LEN(ary); ++i) {
+	v = rb_check_array_type(RARRAY_AREF(ary, i));
+	if (!NIL_P(v) && RARRAY_LEN(v) > 0 &&
+	    rb_equal(RARRAY_AREF(v, 0), key))
+	    return v;
     }
     return Qnil;
 }
 
+/*
+ *  call-seq:
+ *    array.rassoc(obj) -> found_array or nil
+ *
+ *  Returns the first element in +self+ that is an \Array
+ *  whose second element <tt>==</tt> +obj+:
+ *    a = [{foo: 0}, [2, 4], [4, 5, 6], [4, 5]]
+ *    a.rassoc(4) # => [2, 4]
+ *
+ *  Returns +nil+ if no such element is found.
+ *
+ *  Related: #assoc.
+ */
+
 VALUE
-rb_ary_rassoc(ary, value)
-    VALUE ary;
-    VALUE value;
+rb_ary_rassoc(VALUE ary, VALUE value)
 {
-    VALUE *p, *pend;
+    long i;
+    VALUE v;
 
-    p = RARRAY(ary)->ptr; pend = p + RARRAY(ary)->len;
-    while (p < pend) {
-	if (TYPE(*p) == T_ARRAY
-	    && RARRAY(*p)->len > 1
-	    && rb_equal(RARRAY(*p)->ptr[1], value))
-	    return *p;
-	p++;
+    for (i = 0; i < RARRAY_LEN(ary); ++i) {
+	v = RARRAY_AREF(ary, i);
+	if (RB_TYPE_P(v, T_ARRAY) &&
+	    RARRAY_LEN(v) > 1 &&
+	    rb_equal(RARRAY_AREF(v, 1), value))
+	    return v;
     }
     return Qnil;
 }
 
 static VALUE
-rb_ary_equal(ary1, ary2)
-    VALUE ary1, ary2;
+recursive_equal(VALUE ary1, VALUE ary2, int recur)
 {
-    int i;
+    long i, len1;
+    const VALUE *p1, *p2;
+
+    if (recur) return Qtrue; /* Subtle! */
+
+    /* rb_equal() can evacuate ptrs */
+    p1 = RARRAY_CONST_PTR(ary1);
+    p2 = RARRAY_CONST_PTR(ary2);
+    len1 = RARRAY_LEN(ary1);
+
+    for (i = 0; i < len1; i++) {
+	if (*p1 != *p2) {
+	    if (rb_equal(*p1, *p2)) {
+		len1 = RARRAY_LEN(ary1);
+		if (len1 != RARRAY_LEN(ary2))
+		    return Qfalse;
+		if (len1 < i)
+		    return Qtrue;
+                p1 = RARRAY_CONST_PTR(ary1) + i;
+                p2 = RARRAY_CONST_PTR(ary2) + i;
+	    }
+	    else {
+		return Qfalse;
+	    }
+	}
+	p1++;
+	p2++;
+    }
+    return Qtrue;
+}
 
-    if (TYPE(ary2) != T_ARRAY) return Qfalse;
-    if (RARRAY(ary1)->len != RARRAY(ary2)->len) return Qfalse;
-    for (i=0; i<RARRAY(ary1)->len; i++) {
-	if (!rb_equal(RARRAY(ary1)->ptr[i], RARRAY(ary2)->ptr[i]))
+/*
+ *  call-seq:
+ *    array == other_array -> true or false
+ *
+ *  Returns +true+ if both <tt>array.size == other_array.size</tt>
+ *  and for each index +i+ in +array+, <tt>array[i] == other_array[i]</tt>:
+ *    a0 = [:foo, 'bar', 2]
+ *    a1 = [:foo, 'bar', 2.0]
+ *    a1 == a0 # => true
+ *    [] == [] # => true
+ *
+ *  Otherwise, returns +false+.
+ *
+ *  This method is different from method Array#eql?,
+ *  which compares elements using <tt>Object#eql?</tt>.
+ */
+
+static VALUE
+rb_ary_equal(VALUE ary1, VALUE ary2)
+{
+    if (ary1 == ary2) return Qtrue;
+    if (!RB_TYPE_P(ary2, T_ARRAY)) {
+	if (!rb_respond_to(ary2, idTo_ary)) {
 	    return Qfalse;
+	}
+	return rb_equal(ary2, ary1);
     }
-    return Qtrue;
+    if (RARRAY_LEN(ary1) != RARRAY_LEN(ary2)) return Qfalse;
+    if (RARRAY_CONST_PTR_TRANSIENT(ary1) == RARRAY_CONST_PTR_TRANSIENT(ary2)) return Qtrue;
+    return rb_exec_recursive_paired(recursive_equal, ary1, ary2, ary2);
 }
 
 static VALUE
-rb_ary_eql(ary1, ary2)
-    VALUE ary1, ary2;
+recursive_eql(VALUE ary1, VALUE ary2, int recur)
 {
-    int i;
+    long i;
 
-    if (TYPE(ary2) != T_ARRAY) return Qfalse;
-    if (RARRAY(ary1)->len != RARRAY(ary2)->len)
-	return Qfalse;
-    for (i=0; i<RARRAY(ary1)->len; i++) {
-	if (!rb_eql(RARRAY(ary1)->ptr[i], RARRAY(ary2)->ptr[i]))
+    if (recur) return Qtrue; /* Subtle! */
+    for (i=0; i<RARRAY_LEN(ary1); i++) {
+	if (!rb_eql(rb_ary_elt(ary1, i), rb_ary_elt(ary2, i)))
 	    return Qfalse;
     }
     return Qtrue;
 }
 
+/*
+ *  call-seq:
+ *    array.eql? other_array -> true or false
+ *
+ *  Returns +true+ if +self+ and +other_array+ are the same size,
+ *  and if, for each index +i+ in +self+, <tt>self[i].eql? other_array[i]</tt>:
+ *    a0 = [:foo, 'bar', 2]
+ *    a1 = [:foo, 'bar', 2]
+ *    a1.eql?(a0) # => true
+ *
+ *  Otherwise, returns +false+.
+ *
+ *  This method is different from method {Array#==}[#method-i-3D-3D],
+ *  which compares using method <tt>Object#==</tt>.
+ */
+
 static VALUE
-rb_ary_hash(ary)
-    VALUE ary;
+rb_ary_eql(VALUE ary1, VALUE ary2)
 {
-    int i, h;
+    if (ary1 == ary2) return Qtrue;
+    if (!RB_TYPE_P(ary2, T_ARRAY)) return Qfalse;
+    if (RARRAY_LEN(ary1) != RARRAY_LEN(ary2)) return Qfalse;
+    if (RARRAY_CONST_PTR_TRANSIENT(ary1) == RARRAY_CONST_PTR_TRANSIENT(ary2)) return Qtrue;
+    return rb_exec_recursive_paired(recursive_eql, ary1, ary2, ary2);
+}
 
-    h = RARRAY(ary)->len;
-    for (i=0; i<RARRAY(ary)->len; i++) {
-	int n = rb_hash(RARRAY(ary)->ptr[i]);
-	h ^= NUM2LONG(n);
+/*
+ *  call-seq:
+ *    array.hash -> integer
+ *
+ *  Returns the integer hash value for +self+.
+ *
+ *  Two arrays with the same content will have the same hash code (and will compare using eql?):
+ *    [0, 1, 2].hash == [0, 1, 2].hash # => true
+ *    [0, 1, 2].hash == [0, 1, 3].hash # => false
+ */
+
+static VALUE
+rb_ary_hash(VALUE ary)
+{
+    long i;
+    st_index_t h;
+    VALUE n;
+
+    h = rb_hash_start(RARRAY_LEN(ary));
+    h = rb_hash_uint(h, (st_index_t)rb_ary_hash);
+    for (i=0; i<RARRAY_LEN(ary); i++) {
+	n = rb_hash(RARRAY_AREF(ary, i));
+	h = rb_hash_uint(h, NUM2LONG(n));
     }
-    return INT2FIX(h);
+    h = rb_hash_end(h);
+    return ST2FIX(h);
 }
 
+/*
+ *  call-seq:
+ *    array.include?(obj) -> true or false
+ *
+ *  Returns +true+ if for some index +i+ in +self+, <tt>obj == self[i]</tt>;
+ *  otherwise +false+:
+ *    [0, 1, 2].include?(2) # => true
+ *    [0, 1, 2].include?(3) # => false
+ */
+
 VALUE
-rb_ary_includes(ary, item)
-    VALUE ary;
-    VALUE item;
+rb_ary_includes(VALUE ary, VALUE item)
 {
-    int i;
-    for (i=0; i<RARRAY(ary)->len; i++) {
-	if (rb_equal(RARRAY(ary)->ptr[i], item)) {
+    long i;
+    VALUE e;
+
+    for (i=0; i<RARRAY_LEN(ary); i++) {
+	e = RARRAY_AREF(ary, i);
+	if (rb_equal(e, item)) {
 	    return Qtrue;
 	}
     }
@@ -1262,261 +5138,3029 @@ rb_ary_includes(ary, item)
 }
 
 static VALUE
-rb_ary_cmp(ary, ary2)
-    VALUE ary;
-    VALUE ary2;
+rb_ary_includes_by_eql(VALUE ary, VALUE item)
 {
-    int i, len;
+    long i;
+    VALUE e;
 
-    ary2 = to_ary(ary2);
-    len = RARRAY(ary)->len;
-    if (len > RARRAY(ary2)->len) {
-	len = RARRAY(ary2)->len;
+    for (i=0; i<RARRAY_LEN(ary); i++) {
+	e = RARRAY_AREF(ary, i);
+	if (rb_eql(item, e)) {
+	    return Qtrue;
+	}
+    }
+    return Qfalse;
+}
+
+static VALUE
+recursive_cmp(VALUE ary1, VALUE ary2, int recur)
+{
+    long i, len;
+
+    if (recur) return Qundef;	/* Subtle! */
+    len = RARRAY_LEN(ary1);
+    if (len > RARRAY_LEN(ary2)) {
+	len = RARRAY_LEN(ary2);
     }
     for (i=0; i<len; i++) {
-	VALUE v = rb_funcall(RARRAY(ary)->ptr[i],cmp,1,RARRAY(ary2)->ptr[i]);
+	VALUE e1 = rb_ary_elt(ary1, i), e2 = rb_ary_elt(ary2, i);
+	VALUE v = rb_funcallv(e1, id_cmp, 1, &e2);
 	if (v != INT2FIX(0)) {
 	    return v;
 	}
     }
-    len = RARRAY(ary)->len - RARRAY(ary2)->len;
+    return Qundef;
+}
+
+/*
+ *  call-seq:
+ *    array <=> other_array -> -1, 0, or 1
+ *
+ *  Returns -1, 0, or 1 as +self+ is less than, equal to, or greater than +other_array+.
+ *  For each index +i+ in +self+, evaluates <tt>result = self[i] <=> other_array[i]</tt>.
+ *
+ *  Returns -1 if any result is -1:
+ *    [0, 1, 2] <=> [0, 1, 3] # => -1
+ *
+ *  Returns 1 if any result is 1:
+ *    [0, 1, 2] <=> [0, 1, 1] # => 1
+ *
+ *  When all results are zero:
+ *  - Returns -1 if +array+ is smaller than +other_array+:
+ *      [0, 1, 2] <=> [0, 1, 2, 3] # => -1
+ *  - Returns 1 if +array+ is larger than +other_array+:
+ *      [0, 1, 2] <=> [0, 1] # => 1
+ *  - Returns 0 if +array+ and +other_array+ are the same size:
+ *      [0, 1, 2] <=> [0, 1, 2] # => 0
+ */
+
+VALUE
+rb_ary_cmp(VALUE ary1, VALUE ary2)
+{
+    long len;
+    VALUE v;
+
+    ary2 = rb_check_array_type(ary2);
+    if (NIL_P(ary2)) return Qnil;
+    if (ary1 == ary2) return INT2FIX(0);
+    v = rb_exec_recursive_paired(recursive_cmp, ary1, ary2, ary2);
+    if (v != Qundef) return v;
+    len = RARRAY_LEN(ary1) - RARRAY_LEN(ary2);
     if (len == 0) return INT2FIX(0);
     if (len > 0) return INT2FIX(1);
     return INT2FIX(-1);
 }
 
 static VALUE
-rb_ary_diff(ary1, ary2)
-    VALUE ary1, ary2;
+ary_add_hash(VALUE hash, VALUE ary)
+{
+    long i;
+
+    for (i=0; i<RARRAY_LEN(ary); i++) {
+	VALUE elt = RARRAY_AREF(ary, i);
+	rb_hash_add_new_element(hash, elt, elt);
+    }
+    return hash;
+}
+
+static inline VALUE
+ary_tmp_hash_new(VALUE ary)
+{
+    long size = RARRAY_LEN(ary);
+    VALUE hash = rb_hash_new_with_size(size);
+
+    RBASIC_CLEAR_CLASS(hash);
+    return hash;
+}
+
+static VALUE
+ary_make_hash(VALUE ary)
+{
+    VALUE hash = ary_tmp_hash_new(ary);
+    return ary_add_hash(hash, ary);
+}
+
+static VALUE
+ary_add_hash_by(VALUE hash, VALUE ary)
+{
+    long i;
+
+    for (i = 0; i < RARRAY_LEN(ary); ++i) {
+	VALUE v = rb_ary_elt(ary, i), k = rb_yield(v);
+	rb_hash_add_new_element(hash, k, v);
+    }
+    return hash;
+}
+
+static VALUE
+ary_make_hash_by(VALUE ary)
+{
+    VALUE hash = ary_tmp_hash_new(ary);
+    return ary_add_hash_by(hash, ary);
+}
+
+static inline void
+ary_recycle_hash(VALUE hash)
+{
+    assert(RBASIC_CLASS(hash) == 0);
+    if (RHASH_ST_TABLE_P(hash)) {
+        st_table *tbl = RHASH_ST_TABLE(hash);
+	st_free_table(tbl);
+        RHASH_ST_CLEAR(hash);
+    }
+}
+
+/*
+ *  call-seq:
+ *    array - other_array -> new_array
+ *
+ *  Returns a new \Array containing only those elements from +array+
+ *  that are not found in \Array +other_array+;
+ *  items are compared using <tt>eql?</tt>;
+ *  the order from +array+ is preserved:
+ *    [0, 1, 1, 2, 1, 1, 3, 1, 1] - [1] # => [0, 2, 3]
+ *    [0, 1, 2, 3] - [3, 0] # => [1, 2]
+ *    [0, 1, 2] - [4] # => [0, 1, 2]
+ *
+ *  Related: Array#difference.
+ */
+
+static VALUE
+rb_ary_diff(VALUE ary1, VALUE ary2)
 {
     VALUE ary3;
-    int i;
+    VALUE hash;
+    long i;
 
     ary2 = to_ary(ary2);
     ary3 = rb_ary_new();
-    for (i=0; i<RARRAY(ary1)->len; i++) {
-	if (rb_ary_includes(ary2, RARRAY(ary1)->ptr[i])) continue;
-	if (rb_ary_includes(ary3, RARRAY(ary1)->ptr[i])) continue;
-	rb_ary_push(ary3, RARRAY(ary1)->ptr[i]);
+
+    if (RARRAY_LEN(ary1) <= SMALL_ARRAY_LEN || RARRAY_LEN(ary2) <= SMALL_ARRAY_LEN) {
+	for (i=0; i<RARRAY_LEN(ary1); i++) {
+	    VALUE elt = rb_ary_elt(ary1, i);
+	    if (rb_ary_includes_by_eql(ary2, elt)) continue;
+	    rb_ary_push(ary3, elt);
+	}
+	return ary3;
     }
+
+    hash = ary_make_hash(ary2);
+    for (i=0; i<RARRAY_LEN(ary1); i++) {
+        if (rb_hash_stlike_lookup(hash, RARRAY_AREF(ary1, i), NULL)) continue;
+	rb_ary_push(ary3, rb_ary_elt(ary1, i));
+    }
+    ary_recycle_hash(hash);
     return ary3;
 }
 
+/*
+ *  call-seq:
+ *    array.difference(*other_arrays) -> new_array
+ *
+ *  Returns a new \Array containing only those elements from +self+
+ *  that are not found in any of the Arrays +other_arrays+;
+ *  items are compared using <tt>eql?</tt>;  order from +self+ is preserved:
+ *    [0, 1, 1, 2, 1, 1, 3, 1, 1].difference([1]) # => [0, 2, 3]
+ *    [0, 1, 2, 3].difference([3, 0], [1, 3]) # => [2]
+ *    [0, 1, 2].difference([4]) # => [0, 1, 2]
+ *
+ *  Returns a copy of +self+ if no arguments given.
+ *
+ *  Related: Array#-.
+ */
+
 static VALUE
-rb_ary_and(ary1, ary2)
-    VALUE ary1, ary2;
+rb_ary_difference_multi(int argc, VALUE *argv, VALUE ary)
 {
-    VALUE ary3;
-    int i;
+    VALUE ary_diff;
+    long i, length;
+    volatile VALUE t0;
+    bool *is_hash = ALLOCV_N(bool, t0, argc);
+    ary_diff = rb_ary_new();
+    length = RARRAY_LEN(ary);
+
+    for (i = 0; i < argc; i++) {
+        argv[i] = to_ary(argv[i]);
+        is_hash[i] = (length > SMALL_ARRAY_LEN && RARRAY_LEN(argv[i]) > SMALL_ARRAY_LEN);
+        if (is_hash[i]) argv[i] = ary_make_hash(argv[i]);
+    }
+
+    for (i = 0; i < RARRAY_LEN(ary); i++) {
+        int j;
+        VALUE elt = rb_ary_elt(ary, i);
+        for (j = 0; j < argc; j++) {
+            if (is_hash[j]) {
+                if (rb_hash_stlike_lookup(argv[j], RARRAY_AREF(ary, i), NULL))
+                    break;
+            }
+            else {
+                if (rb_ary_includes_by_eql(argv[j], elt)) break;
+            }
+        }
+        if (j == argc) rb_ary_push(ary_diff, elt);
+    }
+
+    ALLOCV_END(t0);
+
+    return ary_diff;
+}
+
+
+/*
+ *  call-seq:
+ *    array & other_array -> new_array
+ *
+ *  Returns a new \Array containing each element found in both +array+ and \Array +other_array+;
+ *  duplicates are omitted; items are compared using <tt>eql?</tt>:
+ *    [0, 1, 2, 3] & [1, 2] # => [1, 2]
+ *    [0, 1, 0, 1] & [0, 1] # => [0, 1]
+ *
+ *  Preserves order from +array+:
+ *    [0, 1, 2] & [3, 2, 1, 0] # => [0, 1, 2]
+ *
+ *  Related: Array#intersection.
+ */
+
+
+static VALUE
+rb_ary_and(VALUE ary1, VALUE ary2)
+{
+    VALUE hash, ary3, v;
+    st_data_t vv;
+    long i;
 
     ary2 = to_ary(ary2);
     ary3 = rb_ary_new();
-    for (i=0; i<RARRAY(ary1)->len; i++) {
-	if (rb_ary_includes(ary2, RARRAY(ary1)->ptr[i])
-	    && !rb_ary_includes(ary3, RARRAY(ary1)->ptr[i])) {
-	    rb_ary_push(ary3, RARRAY(ary1)->ptr[i]);
+    if (RARRAY_LEN(ary1) == 0 || RARRAY_LEN(ary2) == 0) return ary3;
+
+    if (RARRAY_LEN(ary1) <= SMALL_ARRAY_LEN && RARRAY_LEN(ary2) <= SMALL_ARRAY_LEN) {
+	for (i=0; i<RARRAY_LEN(ary1); i++) {
+	    v = RARRAY_AREF(ary1, i);
+	    if (!rb_ary_includes_by_eql(ary2, v)) continue;
+	    if (rb_ary_includes_by_eql(ary3, v)) continue;
+	    rb_ary_push(ary3, v);
 	}
+	return ary3;
     }
+
+    hash = ary_make_hash(ary2);
+
+    for (i=0; i<RARRAY_LEN(ary1); i++) {
+	v = RARRAY_AREF(ary1, i);
+	vv = (st_data_t)v;
+        if (rb_hash_stlike_delete(hash, &vv, 0)) {
+	    rb_ary_push(ary3, v);
+	}
+    }
+    ary_recycle_hash(hash);
+
     return ary3;
 }
 
+/*
+ *  call-seq:
+ *    array.intersection(*other_arrays) -> new_array
+ *
+ *  Returns a new \Array containing each element found both in +self+
+ *  and in all of the given Arrays +other_arrays+;
+ *  duplicates are omitted; items are compared using <tt>eql?</tt>:
+ *    [0, 1, 2, 3].intersection([0, 1, 2], [0, 1, 3]) # => [0, 1]
+ *    [0, 0, 1, 1, 2, 3].intersection([0, 1, 2], [0, 1, 3]) # => [0, 1]
+ *
+ *  Preserves order from +self+:
+ *    [0, 1, 2].intersection([2, 1, 0]) # => [0, 1, 2]
+ *
+ *  Returns a copy of +self+ if no arguments given.
+ *
+ *  Related: Array#&.
+ */
+
 static VALUE
-rb_ary_or(ary1, ary2)
-    VALUE ary1, ary2;
+rb_ary_intersection_multi(int argc, VALUE *argv, VALUE ary)
 {
-    VALUE ary3;
+    VALUE result = rb_ary_dup(ary);
     int i;
 
-    if (TYPE(ary2) != T_ARRAY) {
-	if (rb_ary_includes(ary1, ary2)) return ary1;
-	else return rb_ary_plus(ary1, ary2);
+    for (i = 0; i < argc; i++) {
+        result = rb_ary_and(result, argv[i]);
     }
 
-    ary3 = rb_ary_new();
-    for (i=0; i<RARRAY(ary1)->len; i++) {
-	if (!rb_ary_includes(ary3, RARRAY(ary1)->ptr[i]))
-		rb_ary_push(ary3, RARRAY(ary1)->ptr[i]);
+    return result;
+}
+
+static int
+ary_hash_orset(st_data_t *key, st_data_t *value, st_data_t arg, int existing)
+{
+    if (existing) return ST_STOP;
+    *key = *value = (VALUE)arg;
+    return ST_CONTINUE;
+}
+
+static void
+rb_ary_union(VALUE ary_union, VALUE ary)
+{
+    long i;
+    for (i = 0; i < RARRAY_LEN(ary); i++) {
+        VALUE elt = rb_ary_elt(ary, i);
+        if (rb_ary_includes_by_eql(ary_union, elt)) continue;
+        rb_ary_push(ary_union, elt);
+    }
+}
+
+static void
+rb_ary_union_hash(VALUE hash, VALUE ary2)
+{
+    long i;
+    for (i = 0; i < RARRAY_LEN(ary2); i++) {
+        VALUE elt = RARRAY_AREF(ary2, i);
+        if (!rb_hash_stlike_update(hash, (st_data_t)elt, ary_hash_orset, (st_data_t)elt)) {
+            RB_OBJ_WRITTEN(hash, Qundef, elt);
+        }
     }
-    for (i=0; i<RARRAY(ary2)->len; i++) {
-	if (!rb_ary_includes(ary3, RARRAY(ary2)->ptr[i]))
-		rb_ary_push(ary3, RARRAY(ary2)->ptr[i]);
+}
+
+/*
+ *  call-seq:
+ *    array | other_array -> new_array
+ *
+ *  Returns the union of +array+ and \Array +other_array+;
+ *  duplicates are removed; order is preserved;
+ *  items are compared using <tt>eql?</tt>:
+ *    [0, 1] | [2, 3] # => [0, 1, 2, 3]
+ *    [0, 1, 1] | [2, 2, 3] # => [0, 1, 2, 3]
+ *    [0, 1, 2] | [3, 2, 1, 0] # => [0, 1, 2, 3]
+ *
+ *  Related: Array#union.
+ */
+
+static VALUE
+rb_ary_or(VALUE ary1, VALUE ary2)
+{
+    VALUE hash, ary3;
+
+    ary2 = to_ary(ary2);
+    if (RARRAY_LEN(ary1) + RARRAY_LEN(ary2) <= SMALL_ARRAY_LEN) {
+	ary3 = rb_ary_new();
+        rb_ary_union(ary3, ary1);
+        rb_ary_union(ary3, ary2);
+	return ary3;
     }
+
+    hash = ary_make_hash(ary1);
+    rb_ary_union_hash(hash, ary2);
+
+    ary3 = rb_hash_values(hash);
+    ary_recycle_hash(hash);
     return ary3;
 }
 
+/*
+ *  call-seq:
+ *    array.union(*other_arrays) -> new_array
+ *
+ *  Returns a new \Array that is the union of +self+ and all given Arrays +other_arrays+;
+ *  duplicates are removed;  order is preserved;  items are compared using <tt>eql?</tt>:
+ *    [0, 1, 2, 3].union([4, 5], [6, 7]) # => [0, 1, 2, 3, 4, 5, 6, 7]
+ *    [0, 1, 1].union([2, 1], [3, 1]) # => [0, 1, 2, 3]
+ *    [0, 1, 2, 3].union([3, 2], [1, 0]) # => [0, 1, 2, 3]
+ *
+ *  Returns a copy of +self+ if no arguments given.
+ *
+ *  Related: Array#|.
+ */
+
 static VALUE
-rb_ary_uniq_bang(ary)
-    VALUE ary;
+rb_ary_union_multi(int argc, VALUE *argv, VALUE ary)
+{
+    int i;
+    long sum;
+    VALUE hash, ary_union;
+
+    sum = RARRAY_LEN(ary);
+    for (i = 0; i < argc; i++) {
+        argv[i] = to_ary(argv[i]);
+        sum += RARRAY_LEN(argv[i]);
+    }
+
+    if (sum <= SMALL_ARRAY_LEN) {
+        ary_union = rb_ary_new();
+
+        rb_ary_union(ary_union, ary);
+        for (i = 0; i < argc; i++) rb_ary_union(ary_union, argv[i]);
+
+        return ary_union;
+    }
+
+    hash = ary_make_hash(ary);
+    for (i = 0; i < argc; i++) rb_ary_union_hash(hash, argv[i]);
+
+    ary_union = rb_hash_values(hash);
+    ary_recycle_hash(hash);
+    return ary_union;
+}
+
+static VALUE
+ary_max_generic(VALUE ary, long i, VALUE vmax)
 {
-    VALUE *p, *q, *t, *end;
+    RUBY_ASSERT(i > 0 && i < RARRAY_LEN(ary));
+
     VALUE v;
+    for (; i < RARRAY_LEN(ary); ++i) {
+        v = RARRAY_AREF(ary, i);
 
-    rb_ary_modify(ary);
-    p = RARRAY(ary)->ptr;
-    end = p + RARRAY(ary)->len;
+        if (rb_cmpint(rb_funcallv(vmax, id_cmp, 1, &v), vmax, v) < 0) {
+            vmax = v;
+        }
+    }
+
+    return vmax;
+}
+
+static VALUE
+ary_max_opt_fixnum(VALUE ary, long i, VALUE vmax)
+{
+    const long n = RARRAY_LEN(ary);
+    RUBY_ASSERT(i > 0 && i < n);
+    RUBY_ASSERT(FIXNUM_P(vmax));
+
+    VALUE v;
+    for (; i < n; ++i) {
+        v = RARRAY_AREF(ary, i);
+
+        if (FIXNUM_P(v)) {
+            if ((long)vmax < (long)v) {
+                vmax = v;
+            }
+        }
+        else {
+            return ary_max_generic(ary, i, vmax);
+        }
+    }
+
+    return vmax;
+}
+
+static VALUE
+ary_max_opt_float(VALUE ary, long i, VALUE vmax)
+{
+    const long n = RARRAY_LEN(ary);
+    RUBY_ASSERT(i > 0 && i < n);
+    RUBY_ASSERT(RB_FLOAT_TYPE_P(vmax));
+
+    VALUE v;
+    for (; i < n; ++i) {
+        v = RARRAY_AREF(ary, i);
+
+        if (RB_FLOAT_TYPE_P(v)) {
+            if (rb_float_cmp(vmax, v) < 0) {
+                vmax = v;
+            }
+        }
+        else {
+            return ary_max_generic(ary, i, vmax);
+        }
+    }
+
+    return vmax;
+}
+
+static VALUE
+ary_max_opt_string(VALUE ary, long i, VALUE vmax)
+{
+    const long n = RARRAY_LEN(ary);
+    RUBY_ASSERT(i > 0 && i < n);
+    RUBY_ASSERT(STRING_P(vmax));
+
+    VALUE v;
+    for (; i < n; ++i) {
+        v = RARRAY_AREF(ary, i);
+
+        if (STRING_P(v)) {
+            if (rb_str_cmp(vmax, v) < 0) {
+                vmax = v;
+            }
+        }
+        else {
+            return ary_max_generic(ary, i, vmax);
+        }
+    }
+
+    return vmax;
+}
 
-    while (p < end) {
-	v = *p++;
-	q = t = p;
-	while (q < end) {
-	    if (rb_equal(*q, v)) q++;
-	    else *t++ = *q++;
+/*
+ *  call-seq:
+ *    array.max -> element
+ *    array.max {|a, b| ... } -> element
+ *    array.max(n) -> new_array
+ *    array.max(n) {|a, b| ... } -> new_array
+ *
+ *  Returns one of the following:
+ *  - The maximum-valued element from +self+.
+ *  - A new \Array of maximum-valued elements selected from +self+.
+ *
+ *  When no block is given, each element in +self+ must respond to method <tt><=></tt>
+ *  with an \Integer.
+ *
+ *  With no argument and no block, returns the element in +self+
+ *  having the maximum value per method <tt><=></tt>:
+ *    [0, 1, 2].max # => 2
+ *
+ *  With an argument \Integer +n+ and no block, returns a new \Array with at most +n+ elements,
+ *  in descending order per method <tt><=></tt>:
+ *    [0, 1, 2, 3].max(3) # => [3, 2, 1]
+ *    [0, 1, 2, 3].max(6) # => [3, 2, 1]
+ *
+ *  When a block is given, the block must return an \Integer.
+ *
+ *  With a block and no argument, calls the block <tt>self.size-1</tt> times to compare elements;
+ *  returns the element having the maximum value per the block:
+ *    ['0', '00', '000'].max {|a, b| a.size <=> b.size } # => "000"
+ *
+ *  With an argument +n+ and a block, returns a new \Array with at most +n+ elements,
+ *  in descending order per the block:
+ *    ['0', '00', '000'].max(2) {|a, b| a.size <=> b.size } # => ["000", "00"]
+ */
+static VALUE
+rb_ary_max(int argc, VALUE *argv, VALUE ary)
+{
+    struct cmp_opt_data cmp_opt = { 0, 0 };
+    VALUE result = Qundef, v;
+    VALUE num;
+    long i;
+
+    if (rb_check_arity(argc, 0, 1) && !NIL_P(num = argv[0]))
+       return rb_nmin_run(ary, num, 0, 1, 1);
+
+    const long n = RARRAY_LEN(ary);
+    if (rb_block_given_p()) {
+	for (i = 0; i < RARRAY_LEN(ary); i++) {
+	   v = RARRAY_AREF(ary, i);
+	   if (result == Qundef || rb_cmpint(rb_yield_values(2, v, result), v, result) > 0) {
+	       result = v;
+	   }
 	}
-	end = t;
     }
-    if (RARRAY(ary)->len == (end - RARRAY(ary)->ptr)) {
-	return Qnil;
+    else if (n > 0) {
+        result = RARRAY_AREF(ary, 0);
+        if (n > 1) {
+            if (FIXNUM_P(result) && CMP_OPTIMIZABLE(cmp_opt, Integer)) {
+                return ary_max_opt_fixnum(ary, 1, result);
+            }
+            else if (STRING_P(result) && CMP_OPTIMIZABLE(cmp_opt, String)) {
+                return ary_max_opt_string(ary, 1, result);
+            }
+            else if (RB_FLOAT_TYPE_P(result) && CMP_OPTIMIZABLE(cmp_opt, Float)) {
+                return ary_max_opt_float(ary, 1, result);
+            }
+            else {
+                return ary_max_generic(ary, 1, result);
+            }
+        }
+    }
+    if (result == Qundef) return Qnil;
+    return result;
+}
+
+static VALUE
+ary_min_generic(VALUE ary, long i, VALUE vmin)
+{
+    RUBY_ASSERT(i > 0 && i < RARRAY_LEN(ary));
+
+    VALUE v;
+    for (; i < RARRAY_LEN(ary); ++i) {
+        v = RARRAY_AREF(ary, i);
+
+        if (rb_cmpint(rb_funcallv(vmin, id_cmp, 1, &v), vmin, v) > 0) {
+            vmin = v;
+        }
+    }
+
+    return vmin;
+}
+
+static VALUE
+ary_min_opt_fixnum(VALUE ary, long i, VALUE vmin)
+{
+    const long n = RARRAY_LEN(ary);
+    RUBY_ASSERT(i > 0 && i < n);
+    RUBY_ASSERT(FIXNUM_P(vmin));
+
+    VALUE a;
+    for (; i < n; ++i) {
+        a = RARRAY_AREF(ary, i);
+
+        if (FIXNUM_P(a)) {
+            if ((long)vmin > (long)a) {
+                vmin = a;
+            }
+        }
+        else {
+            return ary_min_generic(ary, i, vmin);
+        }
     }
 
-    RARRAY(ary)->len = (end - RARRAY(ary)->ptr);
+    return vmin;
+}
+
+static VALUE
+ary_min_opt_float(VALUE ary, long i, VALUE vmin)
+{
+    const long n = RARRAY_LEN(ary);
+    RUBY_ASSERT(i > 0 && i < n);
+    RUBY_ASSERT(RB_FLOAT_TYPE_P(vmin));
+
+    VALUE a;
+    for (; i < n; ++i) {
+        a = RARRAY_AREF(ary, i);
+
+        if (RB_FLOAT_TYPE_P(a)) {
+            if (rb_float_cmp(vmin, a) > 0) {
+                vmin = a;
+            }
+        }
+        else {
+            return ary_min_generic(ary, i, vmin);
+        }
+    }
+
+    return vmin;
+}
+
+static VALUE
+ary_min_opt_string(VALUE ary, long i, VALUE vmin)
+{
+    const long n = RARRAY_LEN(ary);
+    RUBY_ASSERT(i > 0 && i < n);
+    RUBY_ASSERT(STRING_P(vmin));
+
+    VALUE a;
+    for (; i < n; ++i) {
+        a = RARRAY_AREF(ary, i);
+
+        if (STRING_P(a)) {
+            if (rb_str_cmp(vmin, a) > 0) {
+                vmin = a;
+            }
+        }
+        else {
+            return ary_min_generic(ary, i, vmin);
+        }
+    }
+
+    return vmin;
+}
+
+/*
+ *  call-seq:
+ *    array.min -> element
+ *    array.min { |a, b| ... } -> element
+ *    array.min(n) -> new_array
+ *    array.min(n) { |a, b| ... } -> new_array
+ *
+ *  Returns one of the following:
+ *  - The minimum-valued element from +self+.
+ *  - A new \Array of minimum-valued elements selected from +self+.
+ *
+ *  When no block is given, each element in +self+ must respond to method <tt><=></tt>
+ *  with an \Integer.
+ *
+ *  With no argument and no block, returns the element in +self+
+ *  having the minimum value per method <tt><=></tt>:
+ *    [0, 1, 2].min # => 0
+ *
+ *  With \Integer argument +n+ and no block, returns a new \Array with at most +n+ elements,
+ *  in ascending order per method <tt><=></tt>:
+ *    [0, 1, 2, 3].min(3) # => [0, 1, 2]
+ *    [0, 1, 2, 3].min(6) # => [0, 1, 2, 3]
+ *
+ *  When a block is given, the block must return an Integer.
+ *
+ *  With a block and no argument, calls the block <tt>self.size-1</tt> times to compare elements;
+ *  returns the element having the minimum value per the block:
+ *    ['0', '00', '000'].min { |a, b| a.size <=> b.size } # => "0"
+ *
+ *  With an argument +n+ and a block, returns a new \Array with at most +n+ elements,
+ *  in ascending order per the block:
+ *    [0, 1, 2, 3].min(3) # => [0, 1, 2]
+ *    [0, 1, 2, 3].min(6) # => [0, 1, 2, 3]
+ */
+static VALUE
+rb_ary_min(int argc, VALUE *argv, VALUE ary)
+{
+    struct cmp_opt_data cmp_opt = { 0, 0 };
+    VALUE result = Qundef, v;
+    VALUE num;
+    long i;
+
+    if (rb_check_arity(argc, 0, 1) && !NIL_P(num = argv[0]))
+       return rb_nmin_run(ary, num, 0, 0, 1);
+
+    const long n = RARRAY_LEN(ary);
+    if (rb_block_given_p()) {
+	for (i = 0; i < RARRAY_LEN(ary); i++) {
+	   v = RARRAY_AREF(ary, i);
+	   if (result == Qundef || rb_cmpint(rb_yield_values(2, v, result), v, result) < 0) {
+	       result = v;
+	   }
+	}
+    }
+    else if (n > 0) {
+        result = RARRAY_AREF(ary, 0);
+        if (n > 1) {
+            if (FIXNUM_P(result) && CMP_OPTIMIZABLE(cmp_opt, Integer)) {
+                return ary_min_opt_fixnum(ary, 1, result);
+            }
+            else if (STRING_P(result) && CMP_OPTIMIZABLE(cmp_opt, String)) {
+                return ary_min_opt_string(ary, 1, result);
+            }
+            else if (RB_FLOAT_TYPE_P(result) && CMP_OPTIMIZABLE(cmp_opt, Float)) {
+                return ary_min_opt_float(ary, 1, result);
+            }
+            else {
+                return ary_min_generic(ary, 1, result);
+            }
+        }
+    }
+    if (result == Qundef) return Qnil;
+    return result;
+}
+
+/*
+ *  call-seq:
+ *    array.minmax -> [min_val, max_val]
+ *    array.minmax {|a, b| ... } -> [min_val, max_val]
+ *
+ *  Returns a new 2-element \Array containing the minimum and maximum values
+ *  from +self+, either per method <tt><=></tt> or per a given block:.
+ *
+ *  When no block is given, each element in +self+ must respond to method <tt><=></tt>
+ *  with an \Integer;
+ *  returns a new 2-element \Array containing the minimum and maximum values
+ *  from +self+, per method <tt><=></tt>:
+ *    [0, 1, 2].minmax # => [0, 2]
+ *
+ *  When a block is given, the block must return an \Integer;
+ *  the block is called <tt>self.size-1</tt> times to compare elements;
+ *  returns a new 2-element \Array containing the minimum and maximum values
+ *  from +self+, per the block:
+ *    ['0', '00', '000'].minmax {|a, b| a.size <=> b.size } # => ["0", "000"]
+ */
+static VALUE
+rb_ary_minmax(VALUE ary)
+{
+    if (rb_block_given_p()) {
+        return rb_call_super(0, NULL);
+    }
+    return rb_assoc_new(rb_ary_min(0, 0, ary), rb_ary_max(0, 0, ary));
+}
+
+static int
+push_value(st_data_t key, st_data_t val, st_data_t ary)
+{
+    rb_ary_push((VALUE)ary, (VALUE)val);
+    return ST_CONTINUE;
+}
+
+/*
+ *  call-seq:
+ *    array.uniq! -> self or nil
+ *    array.uniq! {|element| ... } -> self or nil
+ *
+ *  Removes duplicate elements from +self+, the first occurrence always being retained;
+ *  returns +self+ if any elements removed, +nil+ otherwise.
+ *
+ *  With no block given, identifies and removes elements using method <tt>eql?</tt>
+ *  to compare.
+ *
+ *  Returns +self+ if any elements removed:
+ *    a = [0, 0, 1, 1, 2, 2]
+ *    a.uniq! # => [0, 1, 2]
+ *
+ *  Returns +nil+ if no elements removed.
+ *
+ *  With a block given, calls the block for each element;
+ *  identifies (using method <tt>eql?</tt>) and removes
+ *  elements for which the block returns duplicate values.
+ *
+ *  Returns +self+ if any elements removed:
+ *    a = ['a', 'aa', 'aaa', 'b', 'bb', 'bbb']
+ *    a.uniq! {|element| element.size } # => ['a', 'aa', 'aaa']
+ *
+ *  Returns +nil+ if no elements removed.
+ */
+static VALUE
+rb_ary_uniq_bang(VALUE ary)
+{
+    VALUE hash;
+    long hash_size;
+
+    rb_ary_modify_check(ary);
+    if (RARRAY_LEN(ary) <= 1)
+        return Qnil;
+    if (rb_block_given_p())
+	hash = ary_make_hash_by(ary);
+    else
+	hash = ary_make_hash(ary);
+
+    hash_size = RHASH_SIZE(hash);
+    if (RARRAY_LEN(ary) == hash_size) {
+	return Qnil;
+    }
+    rb_ary_modify_check(ary);
+    ARY_SET_LEN(ary, 0);
+    if (ARY_SHARED_P(ary) && !ARY_EMBED_P(ary)) {
+	rb_ary_unshare(ary);
+	FL_SET_EMBED(ary);
+    }
+    ary_resize_capa(ary, hash_size);
+    rb_hash_foreach(hash, push_value, ary);
+    ary_recycle_hash(hash);
 
     return ary;
 }
 
+/*
+ *  call-seq:
+ *    array.uniq -> new_array
+ *    array.uniq {|element| ... } -> new_array
+ *
+ *  Returns a new \Array containing those elements from +self+ that are not duplicates,
+ *  the first occurrence always being retained.
+ *
+ *  With no block given, identifies and omits duplicates using method <tt>eql?</tt>
+ *  to compare.
+ *    a = [0, 0, 1, 1, 2, 2]
+ *    a.uniq # => [0, 1, 2]
+ *
+ *  With a block given, calls the block for each element;
+ *  identifies (using method <tt>eql?</tt>) and omits duplicate values,
+ *  that is, those elements for which the block returns the same value:
+ *    a = ['a', 'aa', 'aaa', 'b', 'bb', 'bbb']
+ *    a.uniq {|element| element.size } # => ["a", "aa", "aaa"]
+ */
+
 static VALUE
-rb_ary_uniq(ary)
-    VALUE ary;
+rb_ary_uniq(VALUE ary)
 {
-    VALUE v = rb_ary_uniq_bang(rb_ary_dup(ary));
+    VALUE hash, uniq;
 
-    if (NIL_P(v)) return ary;
-    return v;
+    if (RARRAY_LEN(ary) <= 1) {
+        hash = 0;
+        uniq = rb_ary_dup(ary);
+    }
+    else if (rb_block_given_p()) {
+	hash = ary_make_hash_by(ary);
+	uniq = rb_hash_values(hash);
+    }
+    else {
+	hash = ary_make_hash(ary);
+	uniq = rb_hash_values(hash);
+    }
+    if (hash) {
+        ary_recycle_hash(hash);
+    }
+
+    return uniq;
 }
 
+/*
+ *  call-seq:
+ *    array.compact! -> self or nil
+ *
+ *  Removes all +nil+ elements from +self+.
+ *
+ *  Returns +self+ if any elements removed, otherwise +nil+.
+ */
+
 static VALUE
-rb_ary_compact_bang(ary)
-    VALUE ary;
+rb_ary_compact_bang(VALUE ary)
 {
     VALUE *p, *t, *end;
+    long n;
 
     rb_ary_modify(ary);
-    p = t = RARRAY(ary)->ptr;
-    end = p + RARRAY(ary)->len;
+    p = t = (VALUE *)RARRAY_CONST_PTR_TRANSIENT(ary); /* WB: no new reference */
+    end = p + RARRAY_LEN(ary);
+
     while (t < end) {
 	if (NIL_P(*t)) t++;
 	else *p++ = *t++;
     }
-    if (RARRAY(ary)->len == (p - RARRAY(ary)->ptr)) {
+    n = p - RARRAY_CONST_PTR_TRANSIENT(ary);
+    if (RARRAY_LEN(ary) == n) {
 	return Qnil;
     }
-    RARRAY(ary)->len = RARRAY(ary)->capa = (p - RARRAY(ary)->ptr);
-    REALLOC_N(RARRAY(ary)->ptr, VALUE, RARRAY(ary)->len);
+    ary_resize_smaller(ary, n);
 
     return ary;
 }
 
+/*
+ *  call-seq:
+ *    array.compact -> new_array
+ *
+ *  Returns a new \Array containing all non-+nil+ elements from +self+:
+ *    a = [nil, 0, nil, 1, nil, 2, nil]
+ *    a.compact # => [0, 1, 2]
+ */
+
 static VALUE
-rb_ary_compact(ary)
-    VALUE ary;
+rb_ary_compact(VALUE ary)
+{
+    ary = rb_ary_dup(ary);
+    rb_ary_compact_bang(ary);
+    return ary;
+}
+
+/*
+ *  call-seq:
+ *    array.count -> an_integer
+ *    array.count(obj) -> an_integer
+ *    array.count {|element| ... } -> an_integer
+ *
+ *  Returns a count of specified elements.
+ *
+ *  With no argument and no block, returns the count of all elements:
+ *    [0, 1, 2].count # => 3
+ *    [].count # => 0
+ *
+ *  With argument +obj+, returns the count of elements <tt>eql?</tt> to +obj+:
+ *    [0, 1, 2, 0].count(0) # => 2
+ *    [0, 1, 2].count(3) # => 0
+ *
+ *  With no argument and a block given, calls the block with each element;
+ *  returns the count of elements for which the block returns a truthy value:
+ *    [0, 1, 2, 3].count {|element| element > 1} # => 2
+ *
+ *  With argument +obj+ and a block given, issues a warning, ignores the block,
+ *  and returns the count of elements <tt>eql?</tt> to +obj+:
+ */
+
+static VALUE
+rb_ary_count(int argc, VALUE *argv, VALUE ary)
 {
-    VALUE v = rb_ary_compact_bang(rb_ary_dup(ary));
+    long i, n = 0;
 
-    if (NIL_P(v)) return ary;
-    return v;
+    if (rb_check_arity(argc, 0, 1) == 0) {
+	VALUE v;
+
+	if (!rb_block_given_p())
+	    return LONG2NUM(RARRAY_LEN(ary));
+
+	for (i = 0; i < RARRAY_LEN(ary); i++) {
+	    v = RARRAY_AREF(ary, i);
+	    if (RTEST(rb_yield(v))) n++;
+	}
+    }
+    else {
+        VALUE obj = argv[0];
+
+	if (rb_block_given_p()) {
+	    rb_warn("given block not used");
+	}
+	for (i = 0; i < RARRAY_LEN(ary); i++) {
+	    if (rb_equal(RARRAY_AREF(ary, i), obj)) n++;
+	}
+    }
+
+    return LONG2NUM(n);
 }
 
 static VALUE
-rb_ary_nitems(ary)
-    VALUE ary;
+flatten(VALUE ary, int level)
 {
-    int n = 0;
-    VALUE *p, *pend;
+    long i;
+    VALUE stack, result, tmp = 0, elt, vmemo;
+    st_table *memo = 0;
+    st_data_t id;
+
+    for (i = 0; i < RARRAY_LEN(ary); i++) {
+        elt = RARRAY_AREF(ary, i);
+        tmp = rb_check_array_type(elt);
+        if (!NIL_P(tmp)) {
+            break;
+        }
+    }
+    if (i == RARRAY_LEN(ary)) {
+        return ary;
+    }
 
-    p = RARRAY(ary)->ptr;
-    pend = p + RARRAY(ary)->len;
-    while (p < pend) {
-	if (!NIL_P(*p)) n++;
-	p++;
+    result = ary_new(0, RARRAY_LEN(ary));
+    ary_memcpy(result, 0, i, RARRAY_CONST_PTR_TRANSIENT(ary));
+    ARY_SET_LEN(result, i);
+
+    stack = ary_new(0, ARY_DEFAULT_SIZE);
+    rb_ary_push(stack, ary);
+    rb_ary_push(stack, LONG2NUM(i + 1));
+
+    if (level < 0) {
+	vmemo = rb_hash_new();
+	RBASIC_CLEAR_CLASS(vmemo);
+	memo = st_init_numtable();
+	rb_hash_st_table_set(vmemo, memo);
+	st_insert(memo, (st_data_t)ary, (st_data_t)Qtrue);
+	st_insert(memo, (st_data_t)tmp, (st_data_t)Qtrue);
     }
-    return INT2FIX(n);
+
+    ary = tmp;
+    i = 0;
+
+    while (1) {
+	while (i < RARRAY_LEN(ary)) {
+	    elt = RARRAY_AREF(ary, i++);
+	    if (level >= 0 && RARRAY_LEN(stack) / 2 >= level) {
+		rb_ary_push(result, elt);
+		continue;
+	    }
+	    tmp = rb_check_array_type(elt);
+	    if (RBASIC(result)->klass) {
+		if (memo) {
+		    RB_GC_GUARD(vmemo);
+		    st_clear(memo);
+		}
+		rb_raise(rb_eRuntimeError, "flatten reentered");
+	    }
+	    if (NIL_P(tmp)) {
+		rb_ary_push(result, elt);
+	    }
+	    else {
+		if (memo) {
+		    id = (st_data_t)tmp;
+		    if (st_is_member(memo, id)) {
+			st_clear(memo);
+			rb_raise(rb_eArgError, "tried to flatten recursive array");
+		    }
+		    st_insert(memo, id, (st_data_t)Qtrue);
+		}
+		rb_ary_push(stack, ary);
+		rb_ary_push(stack, LONG2NUM(i));
+		ary = tmp;
+		i = 0;
+	    }
+	}
+	if (RARRAY_LEN(stack) == 0) {
+	    break;
+	}
+	if (memo) {
+	    id = (st_data_t)ary;
+	    st_delete(memo, &id, 0);
+	}
+	tmp = rb_ary_pop(stack);
+	i = NUM2LONG(tmp);
+	ary = rb_ary_pop(stack);
+    }
+
+    if (memo) {
+	st_clear(memo);
+    }
+
+    RBASIC_SET_CLASS(result, rb_cArray);
+    return result;
 }
 
+/*
+ *  call-seq:
+ *    array.flatten! -> self or nil
+ *    array.flatten!(level) -> self or nil
+ *
+ *  Replaces each nested \Array in +self+ with the elements from that \Array;
+ *  returns +self+ if any changes, +nil+ otherwise.
+ *
+ *  With non-negative \Integer argument +level+, flattens recursively through +level+ levels:
+ *    a = [ 0, [ 1, [2, 3], 4 ], 5 ]
+ *    a.flatten!(1) # => [0, 1, [2, 3], 4, 5]
+ *    a = [ 0, [ 1, [2, 3], 4 ], 5 ]
+ *    a.flatten!(2) # => [0, 1, 2, 3, 4, 5]
+ *    a = [ 0, [ 1, [2, 3], 4 ], 5 ]
+ *    a.flatten!(3) # => [0, 1, 2, 3, 4, 5]
+ *    [0, 1, 2].flatten!(1) # => nil
+ *
+ *  With no argument, a +nil+ argument, or with negative argument +level+, flattens all levels:
+ *    a = [ 0, [ 1, [2, 3], 4 ], 5 ]
+ *    a.flatten! # => [0, 1, 2, 3, 4, 5]
+ *    [0, 1, 2].flatten! # => nil
+ *    a = [ 0, [ 1, [2, 3], 4 ], 5 ]
+ *    a.flatten!(-1) # => [0, 1, 2, 3, 4, 5]
+ *    a = [ 0, [ 1, [2, 3], 4 ], 5 ]
+ *    a.flatten!(-2) # => [0, 1, 2, 3, 4, 5]
+ *    [0, 1, 2].flatten!(-1) # => nil
+ */
+
 static VALUE
-rb_ary_flatten_bang(ary)
-    VALUE ary;
+rb_ary_flatten_bang(int argc, VALUE *argv, VALUE ary)
 {
-    int i;
-    int mod = 0;
+    int mod = 0, level = -1;
+    VALUE result, lv;
+
+    lv = (rb_check_arity(argc, 0, 1) ? argv[0] : Qnil);
+    rb_ary_modify_check(ary);
+    if (!NIL_P(lv)) level = NUM2INT(lv);
+    if (level == 0) return Qnil;
+
+    result = flatten(ary, level);
+    if (result == ary) {
+	return Qnil;
+    }
+    if (!(mod = ARY_EMBED_P(result))) rb_obj_freeze(result);
+    rb_ary_replace(ary, result);
+    if (mod) ARY_SET_EMBED_LEN(result, 0);
+
+    return ary;
+}
+
+/*
+ *  call-seq:
+ *    array.flatten -> new_array
+ *    array.flatten(level) -> new_array
+ *
+ *  Returns a new \Array that is a recursive flattening of +self+:
+ *  - Each non-Array element is unchanged.
+ *  - Each \Array is replaced by its individual elements.
+ *
+ *  With non-negative \Integer argument +level+, flattens recursively through +level+ levels:
+ *    a = [ 0, [ 1, [2, 3], 4 ], 5 ]
+ *    a.flatten(0) # => [0, [1, [2, 3], 4], 5]
+ *    a = [ 0, [ 1, [2, 3], 4 ], 5 ]
+ *    a.flatten(1) # => [0, 1, [2, 3], 4, 5]
+ *    a = [ 0, [ 1, [2, 3], 4 ], 5 ]
+ *    a.flatten(2) # => [0, 1, 2, 3, 4, 5]
+ *    a = [ 0, [ 1, [2, 3], 4 ], 5 ]
+ *    a.flatten(3) # => [0, 1, 2, 3, 4, 5]
+ *
+ *  With no argument, a +nil+ argument, or with negative argument +level+, flattens all levels:
+ *    a = [ 0, [ 1, [2, 3], 4 ], 5 ]
+ *    a.flatten # => [0, 1, 2, 3, 4, 5]
+ *    [0, 1, 2].flatten # => [0, 1, 2]
+ *    a = [ 0, [ 1, [2, 3], 4 ], 5 ]
+ *    a.flatten(-1) # => [0, 1, 2, 3, 4, 5]
+ *    a = [ 0, [ 1, [2, 3], 4 ], 5 ]
+ *    a.flatten(-2) # => [0, 1, 2, 3, 4, 5]
+ *    [0, 1, 2].flatten(-1) # => [0, 1, 2]
+ */
+
+static VALUE
+rb_ary_flatten(int argc, VALUE *argv, VALUE ary)
+{
+    int level = -1;
+    VALUE result;
+
+    if (rb_check_arity(argc, 0, 1) && !NIL_P(argv[0])) {
+        level = NUM2INT(argv[0]);
+        if (level == 0) return ary_make_shared_copy(ary);
+    }
+
+    result = flatten(ary, level);
+    if (result == ary) {
+        result = ary_make_shared_copy(ary);
+    }
+
+    return result;
+}
+
+#define RAND_UPTO(max) (long)rb_random_ulong_limited((randgen), (max)-1)
+
+static VALUE
+rb_ary_shuffle_bang(rb_execution_context_t *ec, VALUE ary, VALUE randgen)
+{
+    long i, len;
 
     rb_ary_modify(ary);
-    for (i=0; i<RARRAY(ary)->len; i++) {
-	VALUE ary2 = RARRAY(ary)->ptr[i];
-	if (TYPE(ary2) == T_ARRAY) {
-	    rb_ary_replace(ary, i--, 1, ary2);
-	    mod = 1;
+    i = len = RARRAY_LEN(ary);
+    RARRAY_PTR_USE(ary, ptr, {
+	while (i) {
+	    long j = RAND_UPTO(i);
+	    VALUE tmp;
+            if (len != RARRAY_LEN(ary) || ptr != RARRAY_CONST_PTR_TRANSIENT(ary)) {
+                rb_raise(rb_eRuntimeError, "modified during shuffle");
+	    }
+	    tmp = ptr[--i];
+	    ptr[i] = ptr[j];
+	    ptr[j] = tmp;
+	}
+    }); /* WB: no new reference */
+    return ary;
+}
+
+static VALUE
+rb_ary_shuffle(rb_execution_context_t *ec, VALUE ary, VALUE randgen)
+{
+    ary = rb_ary_dup(ary);
+    rb_ary_shuffle_bang(ec, ary, randgen);
+    return ary;
+}
+
+static VALUE
+rb_ary_sample(rb_execution_context_t *ec, VALUE ary, VALUE randgen, VALUE nv, VALUE to_array)
+{
+    VALUE result;
+    long n, len, i, j, k, idx[10];
+    long rnds[numberof(idx)];
+    long memo_threshold;
+
+    len = RARRAY_LEN(ary);
+    if (!to_array) {
+	if (len < 2)
+	    i = 0;
+	else
+	    i = RAND_UPTO(len);
+
+	return rb_ary_elt(ary, i);
+    }
+    n = NUM2LONG(nv);
+    if (n < 0) rb_raise(rb_eArgError, "negative sample number");
+    if (n > len) n = len;
+    if (n <= numberof(idx)) {
+	for (i = 0; i < n; ++i) {
+	    rnds[i] = RAND_UPTO(len - i);
+	}
+    }
+    k = len;
+    len = RARRAY_LEN(ary);
+    if (len < k && n <= numberof(idx)) {
+	for (i = 0; i < n; ++i) {
+	    if (rnds[i] >= len) return rb_ary_new_capa(0);
+	}
+    }
+    if (n > len) n = len;
+    switch (n) {
+      case 0:
+	return rb_ary_new_capa(0);
+      case 1:
+	i = rnds[0];
+	return rb_ary_new_from_args(1, RARRAY_AREF(ary, i));
+      case 2:
+	i = rnds[0];
+	j = rnds[1];
+	if (j >= i) j++;
+	return rb_ary_new_from_args(2, RARRAY_AREF(ary, i), RARRAY_AREF(ary, j));
+      case 3:
+	i = rnds[0];
+	j = rnds[1];
+	k = rnds[2];
+	{
+	    long l = j, g = i;
+	    if (j >= i) l = i, g = ++j;
+	    if (k >= l && (++k >= g)) ++k;
+	}
+	return rb_ary_new_from_args(3, RARRAY_AREF(ary, i), RARRAY_AREF(ary, j), RARRAY_AREF(ary, k));
+    }
+    memo_threshold =
+	len < 2560 ? len / 128 :
+	len < 5120 ? len / 64 :
+	len < 10240 ? len / 32 :
+	len / 16;
+    if (n <= numberof(idx)) {
+	long sorted[numberof(idx)];
+	sorted[0] = idx[0] = rnds[0];
+	for (i=1; i<n; i++) {
+	    k = rnds[i];
+	    for (j = 0; j < i; ++j) {
+		if (k < sorted[j]) break;
+		++k;
+	    }
+	    memmove(&sorted[j+1], &sorted[j], sizeof(sorted[0])*(i-j));
+	    sorted[j] = idx[i] = k;
+	}
+	result = rb_ary_new_capa(n);
+        RARRAY_PTR_USE_TRANSIENT(result, ptr_result, {
+	    for (i=0; i<n; i++) {
+		ptr_result[i] = RARRAY_AREF(ary, idx[i]);
+	    }
+	});
+    }
+    else if (n <= memo_threshold / 2) {
+	long max_idx = 0;
+#undef RUBY_UNTYPED_DATA_WARNING
+#define RUBY_UNTYPED_DATA_WARNING 0
+	VALUE vmemo = Data_Wrap_Struct(0, 0, st_free_table, 0);
+	st_table *memo = st_init_numtable_with_size(n);
+	DATA_PTR(vmemo) = memo;
+	result = rb_ary_new_capa(n);
+	RARRAY_PTR_USE(result, ptr_result, {
+	    for (i=0; i<n; i++) {
+		long r = RAND_UPTO(len-i) + i;
+		ptr_result[i] = r;
+		if (r > max_idx) max_idx = r;
+	    }
+	    len = RARRAY_LEN(ary);
+	    if (len <= max_idx) n = 0;
+	    else if (n > len) n = len;
+            RARRAY_PTR_USE_TRANSIENT(ary, ptr_ary, {
+		for (i=0; i<n; i++) {
+		    long j2 = j = ptr_result[i];
+		    long i2 = i;
+		    st_data_t value;
+		    if (st_lookup(memo, (st_data_t)i, &value)) i2 = (long)value;
+		    if (st_lookup(memo, (st_data_t)j, &value)) j2 = (long)value;
+		    st_insert(memo, (st_data_t)j, (st_data_t)i2);
+		    ptr_result[i] = ptr_ary[j2];
+		}
+	    });
+	});
+	DATA_PTR(vmemo) = 0;
+	st_free_table(memo);
+    }
+    else {
+	result = rb_ary_dup(ary);
+	RBASIC_CLEAR_CLASS(result);
+	RB_GC_GUARD(ary);
+	RARRAY_PTR_USE(result, ptr_result, {
+	    for (i=0; i<n; i++) {
+		j = RAND_UPTO(len-i) + i;
+		nv = ptr_result[j];
+		ptr_result[j] = ptr_result[i];
+		ptr_result[i] = nv;
+	    }
+	});
+	RBASIC_SET_CLASS_RAW(result, rb_cArray);
+    }
+    ARY_SET_LEN(result, n);
+
+    return result;
+}
+
+static VALUE
+rb_ary_cycle_size(VALUE self, VALUE args, VALUE eobj)
+{
+    long mul;
+    VALUE n = Qnil;
+    if (args && (RARRAY_LEN(args) > 0)) {
+	n = RARRAY_AREF(args, 0);
+    }
+    if (RARRAY_LEN(self) == 0) return INT2FIX(0);
+    if (n == Qnil) return DBL2NUM(HUGE_VAL);
+    mul = NUM2LONG(n);
+    if (mul <= 0) return INT2FIX(0);
+    n = LONG2FIX(mul);
+    return rb_fix_mul_fix(rb_ary_length(self), n);
+}
+
+/*
+ *  call-seq:
+ *    array.cycle {|element| ... } -> nil
+ *    array.cycle(count) {|element| ... } -> nil
+ *    array.cycle -> new_enumerator
+ *    array.cycle(count) -> new_enumerator
+ *
+ *  When called with positive \Integer argument +count+ and a block,
+ *  calls the block with each element, then does so again,
+ *  until it has done so +count+ times; returns +nil+:
+ *    output = []
+ *    [0, 1].cycle(2) {|element| output.push(element) } # => nil
+ *    output # => [0, 1, 0, 1]
+ *
+ *  If +count+ is zero or negative, does not call the block:
+ *    [0, 1].cycle(0) {|element| fail 'Cannot happen' } # => nil
+ *    [0, 1].cycle(-1) {|element| fail 'Cannot happen' } # => nil
+ *
+ *  When a block is given, and argument is omitted or +nil+, cycles forever:
+ *    # Prints 0 and 1 forever.
+ *    [0, 1].cycle {|element| puts element }
+ *    [0, 1].cycle(nil) {|element| puts element }
+ *
+ *  When no block is given, returns a new \Enumerator:
+ *
+ *    [0, 1].cycle(2) # => #<Enumerator: [0, 1]:cycle(2)>
+ *    [0, 1].cycle # => # => #<Enumerator: [0, 1]:cycle>
+ *    [0, 1].cycle.first(5) # => [0, 1, 0, 1, 0]
+ */
+static VALUE
+rb_ary_cycle(int argc, VALUE *argv, VALUE ary)
+{
+    long n, i;
+
+    rb_check_arity(argc, 0, 1);
+
+    RETURN_SIZED_ENUMERATOR(ary, argc, argv, rb_ary_cycle_size);
+    if (argc == 0 || NIL_P(argv[0])) {
+        n = -1;
+    }
+    else {
+        n = NUM2LONG(argv[0]);
+        if (n <= 0) return Qnil;
+    }
+
+    while (RARRAY_LEN(ary) > 0 && (n < 0 || 0 < n--)) {
+        for (i=0; i<RARRAY_LEN(ary); i++) {
+            rb_yield(RARRAY_AREF(ary, i));
+        }
+    }
+    return Qnil;
+}
+
+#define tmpary(n) rb_ary_tmp_new(n)
+#define tmpary_discard(a) (ary_discard(a), RBASIC_SET_CLASS_RAW(a, rb_cArray))
+
+/*
+ * Build a ruby array of the corresponding values and yield it to the
+ * associated block.
+ * Return the class of +values+ for reentry check.
+ */
+static int
+yield_indexed_values(const VALUE values, const long r, const long *const p)
+{
+    const VALUE result = rb_ary_new2(r);
+    long i;
+
+    for (i = 0; i < r; i++) ARY_SET(result, i, RARRAY_AREF(values, p[i]));
+    ARY_SET_LEN(result, r);
+    rb_yield(result);
+    return !RBASIC(values)->klass;
+}
+
+/*
+ * Compute permutations of +r+ elements of the set <code>[0..n-1]</code>.
+ *
+ * When we have a complete permutation of array indices, copy the values
+ * at those indices into a new array and yield that array.
+ *
+ * n: the size of the set
+ * r: the number of elements in each permutation
+ * p: the array (of size r) that we're filling in
+ * used: an array of booleans: whether a given index is already used
+ * values: the Ruby array that holds the actual values to permute
+ */
+static void
+permute0(const long n, const long r, long *const p, char *const used, const VALUE values)
+{
+    long i = 0, index = 0;
+
+    for (;;) {
+	const char *const unused = memchr(&used[i], 0, n-i);
+	if (!unused) {
+	    if (!index) break;
+	    i = p[--index];                /* pop index */
+	    used[i++] = 0;                 /* index unused */
+	}
+	else {
+	    i = unused - used;
+	    p[index] = i;
+	    used[i] = 1;                   /* mark index used */
+	    ++index;
+	    if (index < r-1) {             /* if not done yet */
+		p[index] = i = 0;
+		continue;
+	    }
+	    for (i = 0; i < n; ++i) {
+		if (used[i]) continue;
+		p[index] = i;
+		if (!yield_indexed_values(values, r, p)) {
+		    rb_raise(rb_eRuntimeError, "permute reentered");
+		}
+	    }
+	    i = p[--index];                /* pop index */
+	    used[i] = 0;                   /* index unused */
+	    p[index] = ++i;
 	}
     }
-    if (mod == 0) return Qnil;
+}
+
+/*
+ * Returns the product of from, from-1, ..., from - how_many + 1.
+ * https://en.wikipedia.org/wiki/Pochhammer_symbol
+ */
+static VALUE
+descending_factorial(long from, long how_many)
+{
+    VALUE cnt;
+    if (how_many > 0) {
+	cnt = LONG2FIX(from);
+	while (--how_many > 0) {
+	    long v = --from;
+	    cnt = rb_int_mul(cnt, LONG2FIX(v));
+	}
+    }
+    else {
+	cnt = LONG2FIX(how_many == 0);
+    }
+    return cnt;
+}
+
+static VALUE
+binomial_coefficient(long comb, long size)
+{
+    VALUE r;
+    long i;
+    if (comb > size-comb) {
+	comb = size-comb;
+    }
+    if (comb < 0) {
+	return LONG2FIX(0);
+    }
+    else if (comb == 0) {
+	return LONG2FIX(1);
+    }
+    r = LONG2FIX(size);
+    for (i = 1; i < comb; ++i) {
+	r = rb_int_mul(r, LONG2FIX(size - i));
+	r = rb_int_idiv(r, LONG2FIX(i + 1));
+    }
+    return r;
+}
+
+static VALUE
+rb_ary_permutation_size(VALUE ary, VALUE args, VALUE eobj)
+{
+    long n = RARRAY_LEN(ary);
+    long k = (args && (RARRAY_LEN(args) > 0)) ? NUM2LONG(RARRAY_AREF(args, 0)) : n;
+
+    return descending_factorial(n, k);
+}
+
+/*
+ *  call-seq:
+ *    array.permutation {|element| ... } -> self
+ *    array.permutation(n) {|element| ... } -> self
+ *    array.permutation -> new_enumerator
+ *    array.permutation(n) -> new_enumerator
+ *
+ *  When invoked with a block, yield all permutations of elements of +self+; returns +self+.
+ *  The order of permutations is indeterminate.
+ *
+ *  When a block and an in-range positive \Integer argument +n+ (<tt>0 < n <= self.size</tt>)
+ *  are given, calls the block with all +n+-tuple permutations of +self+.
+ *
+ *  Example:
+ *    a = [0, 1, 2]
+ *    a.permutation(2) {|permutation| p permutation }
+ *  Output:
+ *    [0, 1]
+ *    [0, 2]
+ *    [1, 0]
+ *    [1, 2]
+ *    [2, 0]
+ *    [2, 1]
+ *  Another example:
+ *    a = [0, 1, 2]
+ *    a.permutation(3) {|permutation| p permutation }
+ *  Output:
+ *    [0, 1, 2]
+ *    [0, 2, 1]
+ *    [1, 0, 2]
+ *    [1, 2, 0]
+ *    [2, 0, 1]
+ *    [2, 1, 0]
+ *
+ *  When +n+ is zero, calls the block once with a new empty \Array:
+ *    a = [0, 1, 2]
+ *    a.permutation(0) {|permutation| p permutation }
+ *  Output:
+ *    []
+ *
+ *  When +n+ is out of range (negative or larger than <tt>self.size</tt>),
+ *  does not call the block:
+ *    a = [0, 1, 2]
+ *    a.permutation(-1) {|permutation| fail 'Cannot happen' }
+ *    a.permutation(4) {|permutation| fail 'Cannot happen' }
+ *
+ *  When a block given but no argument,
+ *  behaves the same as <tt>a.permutation(a.size)</tt>:
+ *    a = [0, 1, 2]
+ *    a.permutation {|permutation| p permutation }
+ *  Output:
+ *    [0, 1, 2]
+ *    [0, 2, 1]
+ *    [1, 0, 2]
+ *    [1, 2, 0]
+ *    [2, 0, 1]
+ *    [2, 1, 0]
+ *
+ *  Returns a new \Enumerator if no block given:
+ *    a = [0, 1, 2]
+ *    a.permutation # => #<Enumerator: [0, 1, 2]:permutation>
+ *    a.permutation(2) # => #<Enumerator: [0, 1, 2]:permutation(2)>
+ */
+
+static VALUE
+rb_ary_permutation(int argc, VALUE *argv, VALUE ary)
+{
+    long r, n, i;
+
+    n = RARRAY_LEN(ary);                  /* Array length */
+    RETURN_SIZED_ENUMERATOR(ary, argc, argv, rb_ary_permutation_size);   /* Return enumerator if no block */
+    r = n;
+    if (rb_check_arity(argc, 0, 1) && !NIL_P(argv[0]))
+        r = NUM2LONG(argv[0]);            /* Permutation size from argument */
+
+    if (r < 0 || n < r) {
+	/* no permutations: yield nothing */
+    }
+    else if (r == 0) { /* exactly one permutation: the zero-length array */
+	rb_yield(rb_ary_new2(0));
+    }
+    else if (r == 1) { /* this is a special, easy case */
+	for (i = 0; i < RARRAY_LEN(ary); i++) {
+	    rb_yield(rb_ary_new3(1, RARRAY_AREF(ary, i)));
+	}
+    }
+    else {             /* this is the general case */
+	volatile VALUE t0;
+	long *p = ALLOCV_N(long, t0, r+roomof(n, sizeof(long)));
+	char *used = (char*)(p + r);
+	VALUE ary0 = ary_make_shared_copy(ary); /* private defensive copy of ary */
+	RBASIC_CLEAR_CLASS(ary0);
+
+	MEMZERO(used, char, n); /* initialize array */
+
+	permute0(n, r, p, used, ary0); /* compute and yield permutations */
+	ALLOCV_END(t0);
+	RBASIC_SET_CLASS_RAW(ary0, rb_cArray);
+    }
     return ary;
 }
 
+static void
+combinate0(const long len, const long n, long *const stack, const VALUE values)
+{
+    long lev = 0;
+
+    MEMZERO(stack+1, long, n);
+    stack[0] = -1;
+    for (;;) {
+	for (lev++; lev < n; lev++) {
+	    stack[lev+1] = stack[lev]+1;
+	}
+	if (!yield_indexed_values(values, n, stack+1)) {
+	    rb_raise(rb_eRuntimeError, "combination reentered");
+	}
+	do {
+	    if (lev == 0) return;
+	    stack[lev--]++;
+	} while (stack[lev+1]+n == len+lev+1);
+    }
+}
+
 static VALUE
-rb_ary_flatten(ary)
-    VALUE ary;
+rb_ary_combination_size(VALUE ary, VALUE args, VALUE eobj)
+{
+    long n = RARRAY_LEN(ary);
+    long k = NUM2LONG(RARRAY_AREF(args, 0));
+
+    return binomial_coefficient(k, n);
+}
+
+/*
+ *  call-seq:
+ *    array.combination(n) {|element| ... } -> self
+ *    array.combination(n) -> new_enumerator
+ *
+ *  Calls the block, if given, with combinations of elements of +self+;
+ *  returns +self+. The order of combinations is indeterminate.
+ *
+ *  When a block and an in-range positive \Integer argument +n+ (<tt>0 < n <= self.size</tt>)
+ *  are given, calls the block with all +n+-tuple combinations of +self+.
+ *
+ *  Example:
+ *    a = [0, 1, 2]
+ *    a.combination(2) {|combination| p combination }
+ *  Output:
+ *    [0, 1]
+ *    [0, 2]
+ *    [1, 2]
+ *
+ *  Another example:
+ *    a = [0, 1, 2]
+ *    a.combination(3) {|combination| p combination }
+ *  Output:
+ *    [0, 1, 2]
+ *
+ *  When +n+ is zero, calls the block once with a new empty \Array:
+ *    a = [0, 1, 2]
+ *    a1 = a.combination(0) {|combination| p combination }
+ *  Output:
+ *    []
+ *
+ *  When +n+ is out of range (negative or larger than <tt>self.size</tt>),
+ *  does not call the block:
+ *    a = [0, 1, 2]
+ *    a.combination(-1) {|combination| fail 'Cannot happen' }
+ *    a.combination(4) {|combination| fail 'Cannot happen' }
+ *
+ *  Returns a new \Enumerator if no block given:
+ *    a = [0, 1, 2]
+ *    a.combination(2) # => #<Enumerator: [0, 1, 2]:combination(2)>
+ */
+
+static VALUE
+rb_ary_combination(VALUE ary, VALUE num)
+{
+    long i, n, len;
+
+    n = NUM2LONG(num);
+    RETURN_SIZED_ENUMERATOR(ary, 1, &num, rb_ary_combination_size);
+    len = RARRAY_LEN(ary);
+    if (n < 0 || len < n) {
+	/* yield nothing */
+    }
+    else if (n == 0) {
+	rb_yield(rb_ary_new2(0));
+    }
+    else if (n == 1) {
+	for (i = 0; i < RARRAY_LEN(ary); i++) {
+	    rb_yield(rb_ary_new3(1, RARRAY_AREF(ary, i)));
+	}
+    }
+    else {
+	VALUE ary0 = ary_make_shared_copy(ary); /* private defensive copy of ary */
+	volatile VALUE t0;
+	long *stack = ALLOCV_N(long, t0, n+1);
+
+	RBASIC_CLEAR_CLASS(ary0);
+	combinate0(len, n, stack, ary0);
+	ALLOCV_END(t0);
+	RBASIC_SET_CLASS_RAW(ary0, rb_cArray);
+    }
+    return ary;
+}
+
+/*
+ * Compute repeated permutations of +r+ elements of the set
+ * <code>[0..n-1]</code>.
+ *
+ * When we have a complete repeated permutation of array indices, copy the
+ * values at those indices into a new array and yield that array.
+ *
+ * n: the size of the set
+ * r: the number of elements in each permutation
+ * p: the array (of size r) that we're filling in
+ * values: the Ruby array that holds the actual values to permute
+ */
+static void
+rpermute0(const long n, const long r, long *const p, const VALUE values)
+{
+    long i = 0, index = 0;
+
+    p[index] = i;
+    for (;;) {
+	if (++index < r-1) {
+	    p[index] = i = 0;
+	    continue;
+	}
+	for (i = 0; i < n; ++i) {
+	    p[index] = i;
+	    if (!yield_indexed_values(values, r, p)) {
+		rb_raise(rb_eRuntimeError, "repeated permute reentered");
+	    }
+	}
+	do {
+	    if (index <= 0) return;
+	} while ((i = ++p[--index]) >= n);
+    }
+}
+
+static VALUE
+rb_ary_repeated_permutation_size(VALUE ary, VALUE args, VALUE eobj)
+{
+    long n = RARRAY_LEN(ary);
+    long k = NUM2LONG(RARRAY_AREF(args, 0));
+
+    if (k < 0) {
+	return LONG2FIX(0);
+    }
+    if (n <= 0) {
+	return LONG2FIX(!k);
+    }
+    return rb_int_positive_pow(n, (unsigned long)k);
+}
+
+/*
+ *  call-seq:
+ *    array.repeated_permutation(n) {|permutation| ... } -> self
+ *    array.repeated_permutation(n) -> new_enumerator
+ *
+ *  Calls the block with each repeated permutation of length +n+ of the elements of +self+;
+ *  each permutation is an \Array;
+ *  returns +self+. The order of the permutations is indeterminate.
+ *
+ *  When a block and a positive \Integer argument +n+ are given, calls the block with each
+ *  +n+-tuple repeated permutation of the elements of +self+.
+ *  The number of permutations is <tt>self.size**n</tt>.
+ *
+ *  +n+ = 1:
+ *    a = [0, 1, 2]
+ *    a.repeated_permutation(1) {|permutation| p permutation }
+ *  Output:
+ *    [0]
+ *    [1]
+ *    [2]
+ *
+ *  +n+ = 2:
+ *    a.repeated_permutation(2) {|permutation| p permutation }
+ *  Output:
+ *    [0, 0]
+ *    [0, 1]
+ *    [0, 2]
+ *    [1, 0]
+ *    [1, 1]
+ *    [1, 2]
+ *    [2, 0]
+ *    [2, 1]
+ *    [2, 2]
+ *
+ *  If +n+ is zero, calls the block once with an empty \Array.
+ *
+ *  If +n+ is negative, does not call the block:
+ *    a.repeated_permutation(-1) {|permutation| fail 'Cannot happen' }
+ *
+ *  Returns a new \Enumerator if no block given:
+ *    a = [0, 1, 2]
+ *    a.repeated_permutation(2) # => #<Enumerator: [0, 1, 2]:permutation(2)>
+ *
+ *  Using Enumerators, it's convenient to show the permutations and counts
+ *  for some values of +n+:
+ *    e = a.repeated_permutation(0)
+ *    e.size # => 1
+ *    e.to_a # => [[]]
+ *    e = a.repeated_permutation(1)
+ *    e.size # => 3
+ *    e.to_a # => [[0], [1], [2]]
+ *    e = a.repeated_permutation(2)
+ *    e.size # => 9
+ *    e.to_a # => [[0, 0], [0, 1], [0, 2], [1, 0], [1, 1], [1, 2], [2, 0], [2, 1], [2, 2]]
+ */
+static VALUE
+rb_ary_repeated_permutation(VALUE ary, VALUE num)
+{
+    long r, n, i;
+
+    n = RARRAY_LEN(ary);                  /* Array length */
+    RETURN_SIZED_ENUMERATOR(ary, 1, &num, rb_ary_repeated_permutation_size);      /* Return Enumerator if no block */
+    r = NUM2LONG(num);                    /* Permutation size from argument */
+
+    if (r < 0) {
+	/* no permutations: yield nothing */
+    }
+    else if (r == 0) { /* exactly one permutation: the zero-length array */
+	rb_yield(rb_ary_new2(0));
+    }
+    else if (r == 1) { /* this is a special, easy case */
+	for (i = 0; i < RARRAY_LEN(ary); i++) {
+	    rb_yield(rb_ary_new3(1, RARRAY_AREF(ary, i)));
+	}
+    }
+    else {             /* this is the general case */
+	volatile VALUE t0;
+	long *p = ALLOCV_N(long, t0, r);
+	VALUE ary0 = ary_make_shared_copy(ary); /* private defensive copy of ary */
+	RBASIC_CLEAR_CLASS(ary0);
+
+	rpermute0(n, r, p, ary0); /* compute and yield repeated permutations */
+	ALLOCV_END(t0);
+	RBASIC_SET_CLASS_RAW(ary0, rb_cArray);
+    }
+    return ary;
+}
+
+static void
+rcombinate0(const long n, const long r, long *const p, const long rest, const VALUE values)
 {
-    VALUE v = rb_ary_flatten_bang(rb_ary_dup(ary));
+    long i = 0, index = 0;
+
+    p[index] = i;
+    for (;;) {
+	if (++index < r-1) {
+	    p[index] = i;
+	    continue;
+	}
+	for (; i < n; ++i) {
+	    p[index] = i;
+	    if (!yield_indexed_values(values, r, p)) {
+		rb_raise(rb_eRuntimeError, "repeated combination reentered");
+	    }
+	}
+	do {
+	    if (index <= 0) return;
+	} while ((i = ++p[--index]) >= n);
+    }
+}
+
+static VALUE
+rb_ary_repeated_combination_size(VALUE ary, VALUE args, VALUE eobj)
+{
+    long n = RARRAY_LEN(ary);
+    long k = NUM2LONG(RARRAY_AREF(args, 0));
+    if (k == 0) {
+	return LONG2FIX(1);
+    }
+    return binomial_coefficient(k, n + k - 1);
+}
+
+/*
+ *  call-seq:
+ *    array.repeated_combination(n) {|combination| ... } -> self
+ *    array.repeated_combination(n) -> new_enumerator
+ *
+ *  Calls the block with each repeated combination of length +n+ of the elements of +self+;
+ *  each combination is an \Array;
+ *  returns +self+. The order of the combinations is indeterminate.
+ *
+ *  When a block and a positive \Integer argument +n+ are given, calls the block with each
+ *  +n+-tuple repeated combination of the elements of +self+.
+ *  The number of combinations is <tt>(n+1)(n+2)/2</tt>.
+ *
+ *  +n+ = 1:
+ *    a = [0, 1, 2]
+ *    a.repeated_combination(1) {|combination| p combination }
+ *  Output:
+ *    [0]
+ *    [1]
+ *    [2]
+ *
+ *  +n+ = 2:
+ *    a.repeated_combination(2) {|combination| p combination }
+ *  Output:
+ *    [0, 0]
+ *    [0, 1]
+ *    [0, 2]
+ *    [1, 1]
+ *    [1, 2]
+ *    [2, 2]
+ *
+ *  If +n+ is zero, calls the block once with an empty \Array.
+ *
+ *  If +n+ is negative, does not call the block:
+ *    a.repeated_combination(-1) {|combination| fail 'Cannot happen' }
+ *
+ *  Returns a new \Enumerator if no block given:
+ *    a = [0, 1, 2]
+ *    a.repeated_combination(2) # => #<Enumerator: [0, 1, 2]:combination(2)>
+ *
+ *  Using Enumerators, it's convenient to show the combinations and counts
+ *  for some values of +n+:
+ *    e = a.repeated_combination(0)
+ *    e.size # => 1
+ *    e.to_a # => [[]]
+ *    e = a.repeated_combination(1)
+ *    e.size # => 3
+ *    e.to_a # => [[0], [1], [2]]
+ *    e = a.repeated_combination(2)
+ *    e.size # => 6
+ *    e.to_a # => [[0, 0], [0, 1], [0, 2], [1, 1], [1, 2], [2, 2]]
+ */
+
+static VALUE
+rb_ary_repeated_combination(VALUE ary, VALUE num)
+{
+    long n, i, len;
+
+    n = NUM2LONG(num);                 /* Combination size from argument */
+    RETURN_SIZED_ENUMERATOR(ary, 1, &num, rb_ary_repeated_combination_size);   /* Return enumerator if no block */
+    len = RARRAY_LEN(ary);
+    if (n < 0) {
+	/* yield nothing */
+    }
+    else if (n == 0) {
+	rb_yield(rb_ary_new2(0));
+    }
+    else if (n == 1) {
+	for (i = 0; i < RARRAY_LEN(ary); i++) {
+	    rb_yield(rb_ary_new3(1, RARRAY_AREF(ary, i)));
+	}
+    }
+    else if (len == 0) {
+	/* yield nothing */
+    }
+    else {
+	volatile VALUE t0;
+	long *p = ALLOCV_N(long, t0, n);
+	VALUE ary0 = ary_make_shared_copy(ary); /* private defensive copy of ary */
+	RBASIC_CLEAR_CLASS(ary0);
+
+	rcombinate0(len, n, p, n, ary0); /* compute and yield repeated combinations */
+	ALLOCV_END(t0);
+	RBASIC_SET_CLASS_RAW(ary0, rb_cArray);
+    }
+    return ary;
+}
+
+/*
+ *  call-seq:
+ *    array.product(*other_arrays) -> new_array
+ *    array.product(*other_arrays) {|combination| ... } -> self
+ *
+ *  Computes and returns or yields all combinations of elements from all the Arrays,
+ *  including both +self+ and +other_arrays+.
+ *  - The number of combinations is the product of the sizes of all the arrays,
+ *    including both +self+ and +other_arrays+.
+ *  - The order of the returned combinations is indeterminate.
+ *
+ *  When no block is given, returns the combinations as an \Array of Arrays:
+ *    a = [0, 1, 2]
+ *    a1 = [3, 4]
+ *    a2 = [5, 6]
+ *    p = a.product(a1)
+ *    p.size # => 6 # a.size * a1.size
+ *    p # => [[0, 3], [0, 4], [1, 3], [1, 4], [2, 3], [2, 4]]
+ *    p = a.product(a1, a2)
+ *    p.size # => 12 # a.size * a1.size * a2.size
+ *    p # => [[0, 3, 5], [0, 3, 6], [0, 4, 5], [0, 4, 6], [1, 3, 5], [1, 3, 6], [1, 4, 5], [1, 4, 6], [2, 3, 5], [2, 3, 6], [2, 4, 5], [2, 4, 6]]
+ *
+ *  If any argument is an empty \Array, returns an empty \Array.
+ *
+ *  If no argument is given, returns an \Array of 1-element Arrays,
+ *  each containing an element of +self+:
+ *    a.product # => [[0], [1], [2]]
+ *
+ *  When a block is given, yields each combination as an \Array; returns +self+:
+ *    a.product(a1) {|combination| p combination }
+ *  Output:
+ *    [0, 3]
+ *    [0, 4]
+ *    [1, 3]
+ *    [1, 4]
+ *    [2, 3]
+ *    [2, 4]
+ *
+ *  If any argument is an empty \Array, does not call the block:
+ *    a.product(a1, a2, []) {|combination| fail 'Cannot happen' }
+ *
+ *  If no argument is given, yields each element of +self+ as a 1-element \Array:
+ *    a.product {|combination| p combination }
+ *  Output:
+ *    [0]
+ *    [1]
+ *    [2]
+ */
+
+static VALUE
+rb_ary_product(int argc, VALUE *argv, VALUE ary)
+{
+    int n = argc+1;    /* How many arrays we're operating on */
+    volatile VALUE t0 = tmpary(n);
+    volatile VALUE t1 = Qundef;
+    VALUE *arrays = RARRAY_PTR(t0); /* The arrays we're computing the product of */
+    int *counters = ALLOCV_N(int, t1, n); /* The current position in each one */
+    VALUE result = Qnil;      /* The array we'll be returning, when no block given */
+    long i,j;
+    long resultlen = 1;
+
+    RBASIC_CLEAR_CLASS(t0);
+
+    /* initialize the arrays of arrays */
+    ARY_SET_LEN(t0, n);
+    arrays[0] = ary;
+    for (i = 1; i < n; i++) arrays[i] = Qnil;
+    for (i = 1; i < n; i++) arrays[i] = to_ary(argv[i-1]);
+
+    /* initialize the counters for the arrays */
+    for (i = 0; i < n; i++) counters[i] = 0;
+
+    /* Otherwise, allocate and fill in an array of results */
+    if (rb_block_given_p()) {
+	/* Make defensive copies of arrays; exit if any is empty */
+	for (i = 0; i < n; i++) {
+	    if (RARRAY_LEN(arrays[i]) == 0) goto done;
+	    arrays[i] = ary_make_shared_copy(arrays[i]);
+	}
+    }
+    else {
+	/* Compute the length of the result array; return [] if any is empty */
+	for (i = 0; i < n; i++) {
+	    long k = RARRAY_LEN(arrays[i]);
+	    if (k == 0) {
+		result = rb_ary_new2(0);
+		goto done;
+	    }
+            if (MUL_OVERFLOW_LONG_P(resultlen, k))
+		rb_raise(rb_eRangeError, "too big to product");
+	    resultlen *= k;
+	}
+	result = rb_ary_new2(resultlen);
+    }
+    for (;;) {
+	int m;
+	/* fill in one subarray */
+	VALUE subarray = rb_ary_new2(n);
+	for (j = 0; j < n; j++) {
+	    rb_ary_push(subarray, rb_ary_entry(arrays[j], counters[j]));
+	}
+
+	/* put it on the result array */
+	if (NIL_P(result)) {
+	    FL_SET(t0, FL_USER5);
+	    rb_yield(subarray);
+	    if (! FL_TEST(t0, FL_USER5)) {
+		rb_raise(rb_eRuntimeError, "product reentered");
+	    }
+	    else {
+		FL_UNSET(t0, FL_USER5);
+	    }
+	}
+	else {
+	    rb_ary_push(result, subarray);
+	}
+
+	/*
+	 * Increment the last counter.  If it overflows, reset to 0
+	 * and increment the one before it.
+	 */
+	m = n-1;
+	counters[m]++;
+	while (counters[m] == RARRAY_LEN(arrays[m])) {
+	    counters[m] = 0;
+	    /* If the first counter overflows, we are done */
+	    if (--m < 0) goto done;
+	    counters[m]++;
+	}
+    }
+done:
+    tmpary_discard(t0);
+    ALLOCV_END(t1);
 
-    if (NIL_P(v)) return ary;
+    return NIL_P(result) ? ary : result;
+}
+
+/*
+ *  call-seq:
+ *    array.take(n) -> new_array
+ *
+ *  Returns a new \Array containing the first +n+ element of +self+,
+ *  where +n+ is a non-negative \Integer;
+ *  does not modify +self+.
+ *
+ *  Examples:
+ *    a = [0, 1, 2, 3, 4, 5]
+ *    a.take(1) # => [0]
+ *    a.take(2) # => [0, 1]
+ *    a.take(50) # => [0, 1, 2, 3, 4, 5]
+ *    a # => [0, 1, 2, 3, 4, 5]
+ */
+
+static VALUE
+rb_ary_take(VALUE obj, VALUE n)
+{
+    long len = NUM2LONG(n);
+    if (len < 0) {
+	rb_raise(rb_eArgError, "attempt to take negative size");
+    }
+    return rb_ary_subseq(obj, 0, len);
+}
+
+/*
+ *  call-seq:
+ *    array.take_while {|element| ... } -> new_array
+ *    array.take_while -> new_enumerator
+ *
+ *  Returns a new \Array containing zero or more leading elements of +self+;
+ *  does not modify +self+.
+ *
+ *  With a block given, calls the block with each successive element of +self+;
+ *  stops if the block returns +false+ or +nil+;
+ *  returns a new Array containing those elements for which the block returned a truthy value:
+ *    a = [0, 1, 2, 3, 4, 5]
+ *    a.take_while {|element| element < 3 } # => [0, 1, 2]
+ *    a.take_while {|element| true } # => [0, 1, 2, 3, 4, 5]
+ *    a # => [0, 1, 2, 3, 4, 5]
+ *
+ *  With no block given, returns a new \Enumerator:
+ *    [0, 1].take_while # => #<Enumerator: [0, 1]:take_while>
+ */
+
+static VALUE
+rb_ary_take_while(VALUE ary)
+{
+    long i;
+
+    RETURN_ENUMERATOR(ary, 0, 0);
+    for (i = 0; i < RARRAY_LEN(ary); i++) {
+	if (!RTEST(rb_yield(RARRAY_AREF(ary, i)))) break;
+    }
+    return rb_ary_take(ary, LONG2FIX(i));
+}
+
+/*
+ *  call-seq:
+ *    array.drop(n) -> new_array
+ *
+ *  Returns a new \Array containing all but the first +n+ element of +self+,
+ *  where +n+ is a non-negative \Integer;
+ *  does not modify +self+.
+ *
+ *  Examples:
+ *    a = [0, 1, 2, 3, 4, 5]
+ *    a.drop(0) # => [0, 1, 2, 3, 4, 5]
+ *    a.drop(1) # => [1, 2, 3, 4, 5]
+ *    a.drop(2) # => [2, 3, 4, 5]
+ */
+
+static VALUE
+rb_ary_drop(VALUE ary, VALUE n)
+{
+    VALUE result;
+    long pos = NUM2LONG(n);
+    if (pos < 0) {
+	rb_raise(rb_eArgError, "attempt to drop negative size");
+    }
+
+    result = rb_ary_subseq(ary, pos, RARRAY_LEN(ary));
+    if (result == Qnil) result = rb_ary_new();
+    return result;
+}
+
+/*
+ *  call-seq:
+ *    array.drop_while {|element| ... } -> new_array
+ *    array.drop_while -> new_enumerator
+
+ *  Returns a new \Array containing zero or more trailing elements of +self+;
+ *  does not modify +self+.
+ *
+ *  With a block given, calls the block with each successive element of +self+;
+ *  stops if the block returns +false+ or +nil+;
+ *  returns a new Array _omitting_ those elements for which the block returned a truthy value:
+ *    a = [0, 1, 2, 3, 4, 5]
+ *    a.drop_while {|element| element < 3 } # => [3, 4, 5]
+ *
+ *  With no block given, returns a new \Enumerator:
+ *    [0, 1].drop_while # => # => #<Enumerator: [0, 1]:drop_while>
+ */
+
+static VALUE
+rb_ary_drop_while(VALUE ary)
+{
+    long i;
+
+    RETURN_ENUMERATOR(ary, 0, 0);
+    for (i = 0; i < RARRAY_LEN(ary); i++) {
+	if (!RTEST(rb_yield(RARRAY_AREF(ary, i)))) break;
+    }
+    return rb_ary_drop(ary, LONG2FIX(i));
+}
+
+/*
+ *  call-seq:
+ *    array.any? -> true or false
+ *    array.any? {|element| ... } -> true or false
+ *    array.any?(obj) -> true or false
+ *
+ *  Returns +true+ if any element of +self+ meets a given criterion.
+ *
+ *  With no block given and no argument, returns +true+ if +self+ has any truthy element,
+ *  +false+ otherwise:
+ *    [nil, 0, false].any? # => true
+ *    [nil, false].any? # => false
+ *    [].any? # => false
+ *
+ *  With a block given and no argument, calls the block with each element in +self+;
+ *  returns +true+ if the block returns any truthy value, +false+ otherwise:
+ *    [0, 1, 2].any? {|element| element > 1 } # => true
+ *    [0, 1, 2].any? {|element| element > 2 } # => false
+ *
+ *  If argument +obj+ is given, returns +true+ if +obj+.<tt>===</tt> any element,
+ *  +false+ otherwise:
+ *    ['food', 'drink'].any?(/foo/) # => true
+ *    ['food', 'drink'].any?(/bar/) # => false
+ *    [].any?(/foo/) # => false
+ *    [0, 1, 2].any?(1) # => true
+ *    [0, 1, 2].any?(3) # => false
+ *
+ *  Related: Enumerable#any?
+ */
+
+static VALUE
+rb_ary_any_p(int argc, VALUE *argv, VALUE ary)
+{
+    long i, len = RARRAY_LEN(ary);
+
+    rb_check_arity(argc, 0, 1);
+    if (!len) return Qfalse;
+    if (argc) {
+        if (rb_block_given_p()) {
+            rb_warn("given block not used");
+        }
+	for (i = 0; i < RARRAY_LEN(ary); ++i) {
+	    if (RTEST(rb_funcall(argv[0], idEqq, 1, RARRAY_AREF(ary, i)))) return Qtrue;
+	}
+    }
+    else if (!rb_block_given_p()) {
+        for (i = 0; i < len; ++i) {
+            if (RTEST(RARRAY_AREF(ary, i))) return Qtrue;
+        }
+    }
+    else {
+	for (i = 0; i < RARRAY_LEN(ary); ++i) {
+	    if (RTEST(rb_yield(RARRAY_AREF(ary, i)))) return Qtrue;
+	}
+    }
+    return Qfalse;
+}
+
+/*
+ *  call-seq:
+ *    array.all? -> true or false
+ *    array.all? {|element| ... } -> true or false
+ *    array.all?(obj) -> true or false
+ *
+ *  Returns +true+ if all elements of +self+ meet a given criterion.
+ *
+ *  With no block given and no argument, returns +true+ if +self+ contains only truthy elements,
+ *  +false+ otherwise:
+ *    [0, 1, :foo].all? # => true
+ *    [0, nil, 2].all? # => false
+ *    [].all? # => true
+ *
+ *  With a block given and no argument, calls the block with each element in +self+;
+ *  returns +true+ if the block returns only truthy values, +false+ otherwise:
+ *    [0, 1, 2].all? { |element| element < 3 } # => true
+ *    [0, 1, 2].all? { |element| element < 2 } # => false
+ *
+ *  If argument +obj+ is given, returns +true+ if <tt>obj.===</tt> every element, +false+ otherwise:
+ *    ['food', 'fool', 'foot'].all?(/foo/) # => true
+ *    ['food', 'drink'].all?(/bar/) # => false
+ *    [].all?(/foo/) # => true
+ *    [0, 0, 0].all?(0) # => true
+ *    [0, 1, 2].all?(1) # => false
+ *
+ *  Related: Enumerable#all?
+ */
+
+static VALUE
+rb_ary_all_p(int argc, VALUE *argv, VALUE ary)
+{
+    long i, len = RARRAY_LEN(ary);
+
+    rb_check_arity(argc, 0, 1);
+    if (!len) return Qtrue;
+    if (argc) {
+        if (rb_block_given_p()) {
+            rb_warn("given block not used");
+        }
+        for (i = 0; i < RARRAY_LEN(ary); ++i) {
+            if (!RTEST(rb_funcall(argv[0], idEqq, 1, RARRAY_AREF(ary, i)))) return Qfalse;
+        }
+    }
+    else if (!rb_block_given_p()) {
+        for (i = 0; i < len; ++i) {
+            if (!RTEST(RARRAY_AREF(ary, i))) return Qfalse;
+        }
+    }
+    else {
+        for (i = 0; i < RARRAY_LEN(ary); ++i) {
+            if (!RTEST(rb_yield(RARRAY_AREF(ary, i)))) return Qfalse;
+        }
+    }
+    return Qtrue;
+}
+
+/*
+ *  call-seq:
+ *    array.none? -> true or false
+ *    array.none? {|element| ... } -> true or false
+ *    array.none?(obj) -> true or false
+ *
+ *  Returns +true+ if no element of +self+ meet a given criterion.
+ *
+ *  With no block given and no argument, returns +true+ if +self+ has no truthy elements,
+ *  +false+ otherwise:
+ *    [nil, false].none? # => true
+ *    [nil, 0, false].none? # => false
+ *    [].none? # => true
+ *
+ *  With a block given and no argument, calls the block with each element in +self+;
+ *  returns +true+ if the block returns no truthy value, +false+ otherwise:
+ *    [0, 1, 2].none? {|element| element > 3 } # => true
+ *    [0, 1, 2].none? {|element| element > 1 } # => false
+ *
+ *  If argument +obj+ is given, returns +true+ if <tt>obj.===</tt> no element, +false+ otherwise:
+ *    ['food', 'drink'].none?(/bar/) # => true
+ *    ['food', 'drink'].none?(/foo/) # => false
+ *    [].none?(/foo/) # => true
+ *    [0, 1, 2].none?(3) # => true
+ *    [0, 1, 2].none?(1) # => false
+ *
+ *  Related: Enumerable#none?
+ */
+
+static VALUE
+rb_ary_none_p(int argc, VALUE *argv, VALUE ary)
+{
+    long i, len = RARRAY_LEN(ary);
+
+    rb_check_arity(argc, 0, 1);
+    if (!len) return Qtrue;
+    if (argc) {
+        if (rb_block_given_p()) {
+            rb_warn("given block not used");
+        }
+        for (i = 0; i < RARRAY_LEN(ary); ++i) {
+            if (RTEST(rb_funcall(argv[0], idEqq, 1, RARRAY_AREF(ary, i)))) return Qfalse;
+        }
+    }
+    else if (!rb_block_given_p()) {
+        for (i = 0; i < len; ++i) {
+            if (RTEST(RARRAY_AREF(ary, i))) return Qfalse;
+        }
+    }
+    else {
+        for (i = 0; i < RARRAY_LEN(ary); ++i) {
+            if (RTEST(rb_yield(RARRAY_AREF(ary, i)))) return Qfalse;
+        }
+    }
+    return Qtrue;
+}
+
+/*
+ *  call-seq:
+ *    array.one? -> true or false
+ *    array.one? {|element| ... } -> true or false
+ *    array.one?(obj) -> true or false
+ *
+ *  Returns +true+ if exactly one element of +self+ meets a given criterion.
+ *
+ *  With no block given and no argument, returns +true+ if +self+ has exactly one truthy element,
+ *  +false+ otherwise:
+ *    [nil, 0].one? # => true
+ *    [0, 0].one? # => false
+ *    [nil, nil].one? # => false
+ *    [].one? # => false
+ *
+ *  With a block given and no argument, calls the block with each element in +self+;
+ *  returns +true+ if the block a truthy value for exactly one element, +false+ otherwise:
+ *    [0, 1, 2].one? {|element| element > 0 } # => false
+ *    [0, 1, 2].one? {|element| element > 1 } # => true
+ *    [0, 1, 2].one? {|element| element > 2 } # => false
+ *
+ *  If argument +obj+ is given, returns +true+ if <tt>obj.===</tt> exactly one element,
+ *  +false+ otherwise:
+ *    [0, 1, 2].one?(0) # => true
+ *    [0, 0, 1].one?(0) # => false
+ *    [1, 1, 2].one?(0) # => false
+ *    ['food', 'drink'].one?(/bar/) # => false
+ *    ['food', 'drink'].one?(/foo/) # => true
+ *    [].one?(/foo/) # => false
+ *
+ *  Related: Enumerable#one?
+ */
+
+static VALUE
+rb_ary_one_p(int argc, VALUE *argv, VALUE ary)
+{
+    long i, len = RARRAY_LEN(ary);
+    VALUE result = Qfalse;
+
+    rb_check_arity(argc, 0, 1);
+    if (!len) return Qfalse;
+    if (argc) {
+        if (rb_block_given_p()) {
+            rb_warn("given block not used");
+        }
+        for (i = 0; i < RARRAY_LEN(ary); ++i) {
+            if (RTEST(rb_funcall(argv[0], idEqq, 1, RARRAY_AREF(ary, i)))) {
+                if (result) return Qfalse;
+                result = Qtrue;
+            }
+        }
+    }
+    else if (!rb_block_given_p()) {
+        for (i = 0; i < len; ++i) {
+            if (RTEST(RARRAY_AREF(ary, i))) {
+                if (result) return Qfalse;
+                result = Qtrue;
+            }
+        }
+    }
+    else {
+        for (i = 0; i < RARRAY_LEN(ary); ++i) {
+            if (RTEST(rb_yield(RARRAY_AREF(ary, i)))) {
+                if (result) return Qfalse;
+                result = Qtrue;
+            }
+        }
+    }
+    return result;
+}
+
+/*
+ *  call-seq:
+ *    array.dig(index, *identifiers) -> object
+ *
+ *  Finds and returns the object in nested objects
+ *  that is specified by +index+ and +identifiers+.
+ *  The nested objects may be instances of various classes.
+ *  See {Dig Methods}[rdoc-ref:doc/dig_methods.rdoc].
+ *
+ *  Examples:
+ *    a = [:foo, [:bar, :baz, [:bat, :bam]]]
+ *    a.dig(1) # => [:bar, :baz, [:bat, :bam]]
+ *    a.dig(1, 2) # => [:bat, :bam]
+ *    a.dig(1, 2, 0) # => :bat
+ *    a.dig(1, 2, 3) # => nil
+ */
+
+static VALUE
+rb_ary_dig(int argc, VALUE *argv, VALUE self)
+{
+    rb_check_arity(argc, 1, UNLIMITED_ARGUMENTS);
+    self = rb_ary_at(self, *argv);
+    if (!--argc) return self;
+    ++argv;
+    return rb_obj_dig(argc, argv, self, Qnil);
+}
+
+static inline VALUE
+finish_exact_sum(long n, VALUE r, VALUE v, int z)
+{
+    if (n != 0)
+        v = rb_fix_plus(LONG2FIX(n), v);
+    if (r != Qundef) {
+        v = rb_rational_plus(r, v);
+    }
+    else if (!n && z) {
+        v = rb_fix_plus(LONG2FIX(0), v);
+    }
+    return v;
+}
+
+/*
+ * call-seq:
+ *   array.sum(init = 0) -> object
+ *   array.sum(init = 0) {|element| ... } -> object
+ *
+ *  When no block is given, returns the object equivalent to:
+ *    sum = init
+ *    array.each {|element| sum += element }
+ *    sum
+ *  For example, <tt>[e1, e2, e3].sum</tt> returns </tt>init + e1 + e2 + e3</tt>.
+ *
+ *  Examples:
+ *    a = [0, 1, 2, 3]
+ *    a.sum # => 6
+ *    a.sum(100) # => 106
+ *
+ *  The elements need not be numeric, but must be <tt>+</tt>-compatible
+ *  with each other and with +init+:
+ *    a = ['abc', 'def', 'ghi']
+ *    a.sum('jkl') # => "jklabcdefghi"
+ *
+ *  When a block is given, it is called with each element
+ *  and the block's return value (instead of the element itself) is used as the addend:
+ *    a = ['zero', 1, :two]
+ *    s = a.sum('Coerced and concatenated: ') {|element| element.to_s }
+ *    s # => "Coerced and concatenated: zero1two"
+ *
+ *  Notes:
+ *  - Array#join and Array#flatten may be faster than Array#sum
+ *    for an \Array of Strings or an \Array of Arrays.
+ *  - Array#sum method may not respect method redefinition of "+" methods such as Integer#+.
+ */
+
+static VALUE
+rb_ary_sum(int argc, VALUE *argv, VALUE ary)
+{
+    VALUE e, v, r;
+    long i, n;
+    int block_given;
+
+    v = (rb_check_arity(argc, 0, 1) ? argv[0] : LONG2FIX(0));
+
+    block_given = rb_block_given_p();
+
+    if (RARRAY_LEN(ary) == 0)
+        return v;
+
+    n = 0;
+    r = Qundef;
+    for (i = 0; i < RARRAY_LEN(ary); i++) {
+        e = RARRAY_AREF(ary, i);
+        if (block_given)
+            e = rb_yield(e);
+        if (FIXNUM_P(e)) {
+            n += FIX2LONG(e); /* should not overflow long type */
+            if (!FIXABLE(n)) {
+                v = rb_big_plus(LONG2NUM(n), v);
+                n = 0;
+            }
+        }
+        else if (RB_TYPE_P(e, T_BIGNUM))
+            v = rb_big_plus(e, v);
+        else if (RB_TYPE_P(e, T_RATIONAL)) {
+            if (r == Qundef)
+                r = e;
+            else
+                r = rb_rational_plus(r, e);
+        }
+        else
+            goto not_exact;
+    }
+    v = finish_exact_sum(n, r, v, argc!=0);
+    return v;
+
+  not_exact:
+    v = finish_exact_sum(n, r, v, i!=0);
+
+    if (RB_FLOAT_TYPE_P(e)) {
+        /*
+         * Kahan-Babuska balancing compensated summation algorithm
+         * See https://link.springer.com/article/10.1007/s00607-005-0139-x
+         */
+        double f, c;
+        double x, t;
+
+        f = NUM2DBL(v);
+        c = 0.0;
+        goto has_float_value;
+        for (; i < RARRAY_LEN(ary); i++) {
+            e = RARRAY_AREF(ary, i);
+            if (block_given)
+                e = rb_yield(e);
+            if (RB_FLOAT_TYPE_P(e))
+              has_float_value:
+                x = RFLOAT_VALUE(e);
+            else if (FIXNUM_P(e))
+                x = FIX2LONG(e);
+            else if (RB_TYPE_P(e, T_BIGNUM))
+                x = rb_big2dbl(e);
+            else if (RB_TYPE_P(e, T_RATIONAL))
+                x = rb_num2dbl(e);
+            else
+                goto not_float;
+
+            if (isnan(f)) continue;
+            if (isnan(x)) {
+                f = x;
+                continue;
+            }
+            if (isinf(x)) {
+                if (isinf(f) && signbit(x) != signbit(f))
+                    f = NAN;
+                else
+                    f = x;
+                continue;
+            }
+            if (isinf(f)) continue;
+
+            t = f + x;
+            if (fabs(f) >= fabs(x))
+                c += ((f - t) + x);
+            else
+                c += ((x - t) + f);
+            f = t;
+        }
+        f += c;
+        return DBL2NUM(f);
+
+      not_float:
+        v = DBL2NUM(f);
+    }
+
+    goto has_some_value;
+    for (; i < RARRAY_LEN(ary); i++) {
+        e = RARRAY_AREF(ary, i);
+        if (block_given)
+            e = rb_yield(e);
+      has_some_value:
+        v = rb_funcall(v, idPLUS, 1, e);
+    }
     return v;
 }
 
+static VALUE
+rb_ary_deconstruct(VALUE ary)
+{
+    return ary;
+}
+
+/*
+ *  An \Array is an ordered, integer-indexed collection of objects,
+ *  called _elements_.  Any object may be an \Array element.
+ *
+ *  == \Array Indexes
+ *
+ *  \Array indexing starts at 0, as in C or Java.
+ *
+ *  A positive index is an offset from the first element:
+ *  - Index 0 indicates the first element.
+ *  - Index 1 indicates the second element.
+ *  - ...
+ *
+ *  A negative index is an offset, backwards, from the end of the array:
+ *  - Index -1 indicates the last element.
+ *  - Index -2 indicates the next-to-last element.
+ *  - ...
+ *
+ *  A non-negative index is <i>in range</i> if it is smaller than
+ *  the size of the array.  For a 3-element array:
+ *  - Indexes 0 through 2 are in range.
+ *  - Index 3 is out of range.
+ *
+ *  A negative index is <i>in range</i> if its absolute value is
+ *  not larger than the size of the array.  For a 3-element array:
+ *  - Indexes -1 through -3 are in range.
+ *  - Index -4 is out of range.
+ *
+ *  == Creating Arrays
+ *
+ *  A new array can be created by using the literal constructor
+ *  <code>[]</code>.  Arrays can contain different types of objects.  For
+ *  example, the array below contains an Integer, a String and a Float:
+ *
+ *     ary = [1, "two", 3.0] #=> [1, "two", 3.0]
+ *
+ *  An array can also be created by explicitly calling Array.new with zero, one
+ *  (the initial size of the Array) or two arguments (the initial size and a
+ *  default object).
+ *
+ *     ary = Array.new    #=> []
+ *     Array.new(3)       #=> [nil, nil, nil]
+ *     Array.new(3, true) #=> [true, true, true]
+ *
+ *  Note that the second argument populates the array with references to the
+ *  same object.  Therefore, it is only recommended in cases when you need to
+ *  instantiate arrays with natively immutable objects such as Symbols,
+ *  numbers, true or false.
+ *
+ *  To create an array with separate objects a block can be passed instead.
+ *  This method is safe to use with mutable objects such as hashes, strings or
+ *  other arrays:
+ *
+ *     Array.new(4) {Hash.new}    #=> [{}, {}, {}, {}]
+ *     Array.new(4) {|i| i.to_s } #=> ["0", "1", "2", "3"]
+ *
+ *  This is also a quick way to build up multi-dimensional arrays:
+ *
+ *     empty_table = Array.new(3) {Array.new(3)}
+ *     #=> [[nil, nil, nil], [nil, nil, nil], [nil, nil, nil]]
+ *
+ *  An array can also be created by using the Array() method, provided by
+ *  Kernel, which tries to call #to_ary, then #to_a on its argument.
+ *
+ *	Array({:a => "a", :b => "b"}) #=> [[:a, "a"], [:b, "b"]]
+ *
+ *  == Example Usage
+ *
+ *  In addition to the methods it mixes in through the Enumerable module, the
+ *  Array class has proprietary methods for accessing, searching and otherwise
+ *  manipulating arrays.
+ *
+ *  Some of the more common ones are illustrated below.
+ *
+ *  == Accessing Elements
+ *
+ *  Elements in an array can be retrieved using the Array#[] method.  It can
+ *  take a single integer argument (a numeric index), a pair of arguments
+ *  (start and length) or a range. Negative indices start counting from the end,
+ *  with -1 being the last element.
+ *
+ *     arr = [1, 2, 3, 4, 5, 6]
+ *     arr[2]    #=> 3
+ *     arr[100]  #=> nil
+ *     arr[-3]   #=> 4
+ *     arr[2, 3] #=> [3, 4, 5]
+ *     arr[1..4] #=> [2, 3, 4, 5]
+ *     arr[1..-3] #=> [2, 3, 4]
+ *
+ *  Another way to access a particular array element is by using the #at method
+ *
+ *     arr.at(0) #=> 1
+ *
+ *  The #slice method works in an identical manner to Array#[].
+ *
+ *  To raise an error for indices outside of the array bounds or else to
+ *  provide a default value when that happens, you can use #fetch.
+ *
+ *     arr = ['a', 'b', 'c', 'd', 'e', 'f']
+ *     arr.fetch(100) #=> IndexError: index 100 outside of array bounds: -6...6
+ *     arr.fetch(100, "oops") #=> "oops"
+ *
+ *  The special methods #first and #last will return the first and last
+ *  elements of an array, respectively.
+ *
+ *     arr.first #=> 1
+ *     arr.last  #=> 6
+ *
+ *  To return the first +n+ elements of an array, use #take
+ *
+ *     arr.take(3) #=> [1, 2, 3]
+ *
+ *  #drop does the opposite of #take, by returning the elements after +n+
+ *  elements have been dropped:
+ *
+ *     arr.drop(3) #=> [4, 5, 6]
+ *
+ *  == Obtaining Information about an Array
+ *
+ *  Arrays keep track of their own length at all times.  To query an array
+ *  about the number of elements it contains, use #length, #count or #size.
+ *
+ *    browsers = ['Chrome', 'Firefox', 'Safari', 'Opera', 'IE']
+ *    browsers.length #=> 5
+ *    browsers.count #=> 5
+ *
+ *  To check whether an array contains any elements at all
+ *
+ *    browsers.empty? #=> false
+ *
+ *  To check whether a particular item is included in the array
+ *
+ *    browsers.include?('Konqueror') #=> false
+ *
+ *  == Adding Items to Arrays
+ *
+ *  Items can be added to the end of an array by using either #push or #<<
+ *
+ *    arr = [1, 2, 3, 4]
+ *    arr.push(5) #=> [1, 2, 3, 4, 5]
+ *    arr << 6    #=> [1, 2, 3, 4, 5, 6]
+ *
+ *  #unshift will add a new item to the beginning of an array.
+ *
+ *     arr.unshift(0) #=> [0, 1, 2, 3, 4, 5, 6]
+ *
+ *  With #insert you can add a new element to an array at any position.
+ *
+ *     arr.insert(3, 'apple')  #=> [0, 1, 2, 'apple', 3, 4, 5, 6]
+ *
+ *  Using the #insert method, you can also insert multiple values at once:
+ *
+ *     arr.insert(3, 'orange', 'pear', 'grapefruit')
+ *     #=> [0, 1, 2, "orange", "pear", "grapefruit", "apple", 3, 4, 5, 6]
+ *
+ *  == Removing Items from an Array
+ *
+ *  The method #pop removes the last element in an array and returns it:
+ *
+ *     arr =  [1, 2, 3, 4, 5, 6]
+ *     arr.pop #=> 6
+ *     arr #=> [1, 2, 3, 4, 5]
+ *
+ *  To retrieve and at the same time remove the first item, use #shift:
+ *
+ *     arr.shift #=> 1
+ *     arr #=> [2, 3, 4, 5]
+ *
+ *  To delete an element at a particular index:
+ *
+ *     arr.delete_at(2) #=> 4
+ *     arr #=> [2, 3, 5]
+ *
+ *  To delete a particular element anywhere in an array, use #delete:
+ *
+ *     arr = [1, 2, 2, 3]
+ *     arr.delete(2) #=> 2
+ *     arr #=> [1,3]
+ *
+ *  A useful method if you need to remove +nil+ values from an array is
+ *  #compact:
+ *
+ *     arr = ['foo', 0, nil, 'bar', 7, 'baz', nil]
+ *     arr.compact  #=> ['foo', 0, 'bar', 7, 'baz']
+ *     arr          #=> ['foo', 0, nil, 'bar', 7, 'baz', nil]
+ *     arr.compact! #=> ['foo', 0, 'bar', 7, 'baz']
+ *     arr          #=> ['foo', 0, 'bar', 7, 'baz']
+ *
+ *  Another common need is to remove duplicate elements from an array.
+ *
+ *  It has the non-destructive #uniq, and destructive method #uniq!
+ *
+ *     arr = [2, 5, 6, 556, 6, 6, 8, 9, 0, 123, 556]
+ *     arr.uniq #=> [2, 5, 6, 556, 8, 9, 0, 123]
+ *
+ *  == Iterating over Arrays
+ *
+ *  Like all classes that include the Enumerable module, Array has an each
+ *  method, which defines what elements should be iterated over and how.  In
+ *  case of Array's #each, all elements in the Array instance are yielded to
+ *  the supplied block in sequence.
+ *
+ *  Note that this operation leaves the array unchanged.
+ *
+ *     arr = [1, 2, 3, 4, 5]
+ *     arr.each {|a| print a -= 10, " "}
+ *     # prints: -9 -8 -7 -6 -5
+ *     #=> [1, 2, 3, 4, 5]
+ *
+ *  Another sometimes useful iterator is #reverse_each which will iterate over
+ *  the elements in the array in reverse order.
+ *
+ *     words = %w[first second third fourth fifth sixth]
+ *     str = ""
+ *     words.reverse_each {|word| str += "#{word} "}
+ *     p str #=> "sixth fifth fourth third second first "
+ *
+ *  The #map method can be used to create a new array based on the original
+ *  array, but with the values modified by the supplied block:
+ *
+ *     arr.map {|a| 2*a}     #=> [2, 4, 6, 8, 10]
+ *     arr                   #=> [1, 2, 3, 4, 5]
+ *     arr.map! {|a| a**2}   #=> [1, 4, 9, 16, 25]
+ *     arr                   #=> [1, 4, 9, 16, 25]
+ *
+ *  == Selecting Items from an Array
+ *
+ *  Elements can be selected from an array according to criteria defined in a
+ *  block.  The selection can happen in a destructive or a non-destructive
+ *  manner.  While the destructive operations will modify the array they were
+ *  called on, the non-destructive methods usually return a new array with the
+ *  selected elements, but leave the original array unchanged.
+ *
+ *  === Non-destructive Selection
+ *
+ *     arr = [1, 2, 3, 4, 5, 6]
+ *     arr.select {|a| a > 3}       #=> [4, 5, 6]
+ *     arr.reject {|a| a < 3}       #=> [3, 4, 5, 6]
+ *     arr.drop_while {|a| a < 4}   #=> [4, 5, 6]
+ *     arr                          #=> [1, 2, 3, 4, 5, 6]
+ *
+ *  === Destructive Selection
+ *
+ *  #select! and #reject! are the corresponding destructive methods to #select
+ *  and #reject
+ *
+ *  Similar to #select vs. #reject, #delete_if and #keep_if have the exact
+ *  opposite result when supplied with the same block:
+ *
+ *     arr.delete_if {|a| a < 4}   #=> [4, 5, 6]
+ *     arr                         #=> [4, 5, 6]
+ *
+ *     arr = [1, 2, 3, 4, 5, 6]
+ *     arr.keep_if {|a| a < 4}   #=> [1, 2, 3]
+ *     arr                       #=> [1, 2, 3]
+ */
+
 void
-Init_Array()
+Init_Array(void)
 {
     rb_cArray  = rb_define_class("Array", rb_cObject);
     rb_include_module(rb_cArray, rb_mEnumerable);
 
-    rb_define_singleton_method(rb_cArray, "new", rb_ary_s_new, -1);
+    rb_define_alloc_func(rb_cArray, empty_ary_alloc);
     rb_define_singleton_method(rb_cArray, "[]", rb_ary_s_create, -1);
-    rb_define_method(rb_cArray, "to_s", rb_ary_to_s, 0);
+    rb_define_singleton_method(rb_cArray, "try_convert", rb_ary_s_try_convert, 1);
+    rb_define_method(rb_cArray, "initialize", rb_ary_initialize, -1);
+    rb_define_method(rb_cArray, "initialize_copy", rb_ary_replace, 1);
+
     rb_define_method(rb_cArray, "inspect", rb_ary_inspect, 0);
+    rb_define_alias(rb_cArray,  "to_s", "inspect");
     rb_define_method(rb_cArray, "to_a", rb_ary_to_a, 0);
-    rb_define_method(rb_cArray, "to_ary", rb_ary_to_a, 0);
-
-    rb_define_method(rb_cArray, "freeze",  rb_ary_freeze, 0);
-    rb_define_method(rb_cArray, "frozen?",  rb_ary_frozen_p, 0);
+    rb_define_method(rb_cArray, "to_h", rb_ary_to_h, 0);
+    rb_define_method(rb_cArray, "to_ary", rb_ary_to_ary_m, 0);
 
     rb_define_method(rb_cArray, "==", rb_ary_equal, 1);
     rb_define_method(rb_cArray, "eql?", rb_ary_eql, 1);
     rb_define_method(rb_cArray, "hash", rb_ary_hash, 0);
-    rb_define_method(rb_cArray, "===", rb_ary_equal, 1);
 
     rb_define_method(rb_cArray, "[]", rb_ary_aref, -1);
     rb_define_method(rb_cArray, "[]=", rb_ary_aset, -1);
-    rb_define_method(rb_cArray, "concat", rb_ary_concat, 1);
+    rb_define_method(rb_cArray, "at", rb_ary_at, 1);
+    rb_define_method(rb_cArray, "fetch", rb_ary_fetch, -1);
+    rb_define_method(rb_cArray, "first", rb_ary_first, -1);
+    rb_define_method(rb_cArray, "last", rb_ary_last, -1);
+    rb_define_method(rb_cArray, "concat", rb_ary_concat_multi, -1);
+    rb_define_method(rb_cArray, "union", rb_ary_union_multi, -1);
+    rb_define_method(rb_cArray, "difference", rb_ary_difference_multi, -1);
+    rb_define_method(rb_cArray, "intersection", rb_ary_intersection_multi, -1);
     rb_define_method(rb_cArray, "<<", rb_ary_push, 1);
-    rb_define_method(rb_cArray, "push", rb_ary_push_method, -1);
-    rb_define_method(rb_cArray, "pop", rb_ary_pop, 0);
-    rb_define_method(rb_cArray, "shift", rb_ary_shift, 0);
-    rb_define_method(rb_cArray, "unshift", rb_ary_unshift, 1);
+    rb_define_method(rb_cArray, "push", rb_ary_push_m, -1);
+    rb_define_alias(rb_cArray,  "append", "push");
+    rb_define_method(rb_cArray, "pop", rb_ary_pop_m, -1);
+    rb_define_method(rb_cArray, "shift", rb_ary_shift_m, -1);
+    rb_define_method(rb_cArray, "unshift", rb_ary_unshift_m, -1);
+    rb_define_alias(rb_cArray,  "prepend", "unshift");
+    rb_define_method(rb_cArray, "insert", rb_ary_insert, -1);
     rb_define_method(rb_cArray, "each", rb_ary_each, 0);
     rb_define_method(rb_cArray, "each_index", rb_ary_each_index, 0);
     rb_define_method(rb_cArray, "reverse_each", rb_ary_reverse_each, 0);
     rb_define_method(rb_cArray, "length", rb_ary_length, 0);
-    rb_define_alias(rb_cArray,  "size", "length");
+    rb_define_method(rb_cArray, "size", rb_ary_length, 0);
     rb_define_method(rb_cArray, "empty?", rb_ary_empty_p, 0);
-    rb_define_method(rb_cArray, "index", rb_ary_index, 1);
-    rb_define_method(rb_cArray, "rindex", rb_ary_rindex, 1);
-    rb_define_method(rb_cArray, "indexes", rb_ary_indexes, -1);
-    rb_define_method(rb_cArray, "indices", rb_ary_indexes, -1);
-    rb_define_method(rb_cArray, "clone", rb_ary_clone, 0);
-    rb_define_method(rb_cArray, "dup", rb_ary_dup, 0);
-    rb_define_method(rb_cArray, "join", rb_ary_join_method, -1);
-    rb_define_method(rb_cArray, "reverse", rb_ary_reverse_method, 0);
-    rb_define_method(rb_cArray, "reverse!", rb_ary_reverse, 0);
+    rb_define_method(rb_cArray, "find_index", rb_ary_index, -1);
+    rb_define_method(rb_cArray, "index", rb_ary_index, -1);
+    rb_define_method(rb_cArray, "rindex", rb_ary_rindex, -1);
+    rb_define_method(rb_cArray, "join", rb_ary_join_m, -1);
+    rb_define_method(rb_cArray, "reverse", rb_ary_reverse_m, 0);
+    rb_define_method(rb_cArray, "reverse!", rb_ary_reverse_bang, 0);
+    rb_define_method(rb_cArray, "rotate", rb_ary_rotate_m, -1);
+    rb_define_method(rb_cArray, "rotate!", rb_ary_rotate_bang, -1);
     rb_define_method(rb_cArray, "sort", rb_ary_sort, 0);
     rb_define_method(rb_cArray, "sort!", rb_ary_sort_bang, 0);
+    rb_define_method(rb_cArray, "sort_by!", rb_ary_sort_by_bang, 0);
+    rb_define_method(rb_cArray, "collect", rb_ary_collect, 0);
+    rb_define_method(rb_cArray, "collect!", rb_ary_collect_bang, 0);
+    rb_define_method(rb_cArray, "map", rb_ary_collect, 0);
+    rb_define_method(rb_cArray, "map!", rb_ary_collect_bang, 0);
+    rb_define_method(rb_cArray, "select", rb_ary_select, 0);
+    rb_define_method(rb_cArray, "select!", rb_ary_select_bang, 0);
+    rb_define_method(rb_cArray, "filter", rb_ary_select, 0);
+    rb_define_method(rb_cArray, "filter!", rb_ary_select_bang, 0);
+    rb_define_method(rb_cArray, "keep_if", rb_ary_keep_if, 0);
+    rb_define_method(rb_cArray, "values_at", rb_ary_values_at, -1);
     rb_define_method(rb_cArray, "delete", rb_ary_delete, 1);
-    rb_define_method(rb_cArray, "delete_at", rb_ary_delete_at, 1);
+    rb_define_method(rb_cArray, "delete_at", rb_ary_delete_at_m, 1);
     rb_define_method(rb_cArray, "delete_if", rb_ary_delete_if, 0);
-    rb_define_method(rb_cArray, "reject!", rb_ary_delete_if, 0);
-    rb_define_method(rb_cArray, "filter", rb_ary_filter, 0);
-    rb_define_method(rb_cArray, "replace", rb_ary_replace_method, 1);
+    rb_define_method(rb_cArray, "reject", rb_ary_reject, 0);
+    rb_define_method(rb_cArray, "reject!", rb_ary_reject_bang, 0);
+    rb_define_method(rb_cArray, "zip", rb_ary_zip, -1);
+    rb_define_method(rb_cArray, "transpose", rb_ary_transpose, 0);
+    rb_define_method(rb_cArray, "replace", rb_ary_replace, 1);
     rb_define_method(rb_cArray, "clear", rb_ary_clear, 0);
     rb_define_method(rb_cArray, "fill", rb_ary_fill, -1);
     rb_define_method(rb_cArray, "include?", rb_ary_includes, 1);
     rb_define_method(rb_cArray, "<=>", rb_ary_cmp, 1);
 
+    rb_define_method(rb_cArray, "slice", rb_ary_aref, -1);
+    rb_define_method(rb_cArray, "slice!", rb_ary_slice_bang, -1);
+
     rb_define_method(rb_cArray, "assoc", rb_ary_assoc, 1);
     rb_define_method(rb_cArray, "rassoc", rb_ary_rassoc, 1);
 
@@ -1527,13 +8171,38 @@ Init_Array()
     rb_define_method(rb_cArray, "&", rb_ary_and, 1);
     rb_define_method(rb_cArray, "|", rb_ary_or, 1);
 
+    rb_define_method(rb_cArray, "max", rb_ary_max, -1);
+    rb_define_method(rb_cArray, "min", rb_ary_min, -1);
+    rb_define_method(rb_cArray, "minmax", rb_ary_minmax, 0);
+
     rb_define_method(rb_cArray, "uniq", rb_ary_uniq, 0);
     rb_define_method(rb_cArray, "uniq!", rb_ary_uniq_bang, 0);
     rb_define_method(rb_cArray, "compact", rb_ary_compact, 0);
     rb_define_method(rb_cArray, "compact!", rb_ary_compact_bang, 0);
-    rb_define_method(rb_cArray, "flatten", rb_ary_flatten, 0);
-    rb_define_method(rb_cArray, "flatten!", rb_ary_flatten_bang, 0);
-    rb_define_method(rb_cArray, "nitems", rb_ary_nitems, 0);
-
-    cmp = rb_intern("<=>");
+    rb_define_method(rb_cArray, "flatten", rb_ary_flatten, -1);
+    rb_define_method(rb_cArray, "flatten!", rb_ary_flatten_bang, -1);
+    rb_define_method(rb_cArray, "count", rb_ary_count, -1);
+    rb_define_method(rb_cArray, "cycle", rb_ary_cycle, -1);
+    rb_define_method(rb_cArray, "permutation", rb_ary_permutation, -1);
+    rb_define_method(rb_cArray, "combination", rb_ary_combination, 1);
+    rb_define_method(rb_cArray, "repeated_permutation", rb_ary_repeated_permutation, 1);
+    rb_define_method(rb_cArray, "repeated_combination", rb_ary_repeated_combination, 1);
+    rb_define_method(rb_cArray, "product", rb_ary_product, -1);
+
+    rb_define_method(rb_cArray, "take", rb_ary_take, 1);
+    rb_define_method(rb_cArray, "take_while", rb_ary_take_while, 0);
+    rb_define_method(rb_cArray, "drop", rb_ary_drop, 1);
+    rb_define_method(rb_cArray, "drop_while", rb_ary_drop_while, 0);
+    rb_define_method(rb_cArray, "bsearch", rb_ary_bsearch, 0);
+    rb_define_method(rb_cArray, "bsearch_index", rb_ary_bsearch_index, 0);
+    rb_define_method(rb_cArray, "any?", rb_ary_any_p, -1);
+    rb_define_method(rb_cArray, "all?", rb_ary_all_p, -1);
+    rb_define_method(rb_cArray, "none?", rb_ary_none_p, -1);
+    rb_define_method(rb_cArray, "one?", rb_ary_one_p, -1);
+    rb_define_method(rb_cArray, "dig", rb_ary_dig, -1);
+    rb_define_method(rb_cArray, "sum", rb_ary_sum, -1);
+
+    rb_define_method(rb_cArray, "deconstruct", rb_ary_deconstruct, 0);
 }
+
+#include "array.rbinc"
diff --git a/array.rb b/array.rb
new file mode 100644
index 0000000000..a43a3b27b1
--- /dev/null
+++ b/array.rb
@@ -0,0 +1,61 @@
+class Array
+  # call-seq:
+  #    array.shuffle!(random: Random) -> array
+  #
+  # Shuffles the elements of +self+ in place.
+  #    a = [1, 2, 3] #=> [1, 2, 3]
+  #    a.shuffle!    #=> [2, 3, 1]
+  #    a             #=> [2, 3, 1]
+  #
+  # The optional +random+ argument will be used as the random number generator:
+  #    a.shuffle!(random: Random.new(1))  #=> [1, 3, 2]
+  def shuffle!(random: Random)
+    Primitive.rb_ary_shuffle_bang(random)
+  end
+
+  # call-seq:
+  #    array.shuffle(random: Random) -> new_ary
+  #
+  # Returns a new array with elements of +self+ shuffled.
+  #    a = [1, 2, 3] #=> [1, 2, 3]
+  #    a.shuffle     #=> [2, 3, 1]
+  #    a             #=> [1, 2, 3]
+  #
+  # The optional +random+ argument will be used as the random number generator:
+  #    a.shuffle(random: Random.new(1))  #=> [1, 3, 2]
+  def shuffle(random: Random)
+    Primitive.rb_ary_shuffle(random)
+  end
+
+  # call-seq:
+  #    array.sample(random: Random) -> object
+  #    array.sample(n, random: Random) -> new_ary
+  #
+  # Returns random elements from +self+.
+  #
+  # When no arguments are given, returns a random element from +self+:
+  #    a = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
+  #    a.sample # => 3
+  #    a.sample # => 8
+  # If +self+ is empty, returns +nil+.
+  #
+  # When argument +n+ is given, returns a new \Array containing +n+ random
+  # elements from +self+:
+  #    a.sample(3) # => [8, 9, 2]
+  #    a.sample(6) # => [9, 6, 10, 3, 1, 4]
+  # Returns no more than <tt>a.size</tt> elements
+  # (because no new duplicates are introduced):
+  #    a.sample(a.size * 2) # => [6, 4, 1, 8, 5, 9, 10, 2, 3, 7]
+  # But +self+ may contain duplicates:
+  #    a = [1, 1, 1, 2, 2, 3]
+  #    a.sample(a.size * 2) # => [1, 1, 3, 2, 1, 2]
+  # Returns a new empty \Array if +self+ is empty.
+  #
+  # The optional +random+ argument will be used as the random number generator:
+  #    a = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
+  #    a.sample(random: Random.new(1))     #=> 6
+  #    a.sample(4, random: Random.new(1))  #=> [6, 10, 9, 2]
+  def sample(n = (ary = false), random: Random)
+    Primitive.rb_ary_sample(random, n, ary)
+  end
+end
diff --git a/ast.c b/ast.c
new file mode 100644
index 0000000000..2af0b3e530
--- /dev/null
+++ b/ast.c
@@ -0,0 +1,699 @@
+/* indent-tabs-mode: nil */
+#include "internal.h"
+#include "internal/parse.h"
+#include "internal/symbol.h"
+#include "internal/warnings.h"
+#include "iseq.h"
+#include "node.h"
+#include "ruby.h"
+#include "ruby/encoding.h"
+#include "ruby/util.h"
+#include "vm_core.h"
+
+#include "builtin.h"
+
+static VALUE rb_mAST;
+static VALUE rb_cNode;
+
+struct ASTNodeData {
+    rb_ast_t *ast;
+    const NODE *node;
+};
+
+static void
+node_gc_mark(void *ptr)
+{
+    struct ASTNodeData *data = (struct ASTNodeData *)ptr;
+    rb_gc_mark((VALUE)data->ast);
+}
+
+static size_t
+node_memsize(const void *ptr)
+{
+    struct ASTNodeData *data = (struct ASTNodeData *)ptr;
+    return rb_ast_memsize(data->ast);
+}
+
+static const rb_data_type_t rb_node_type = {
+    "AST/node",
+    {node_gc_mark, RUBY_TYPED_DEFAULT_FREE, node_memsize,},
+    0, 0,
+    RUBY_TYPED_FREE_IMMEDIATELY,
+};
+
+static VALUE rb_ast_node_alloc(VALUE klass);
+
+static void
+setup_node(VALUE obj, rb_ast_t *ast, const NODE *node)
+{
+    struct ASTNodeData *data;
+
+    TypedData_Get_Struct(obj, struct ASTNodeData, &rb_node_type, data);
+    data->ast = ast;
+    data->node = node;
+}
+
+static VALUE
+ast_new_internal(rb_ast_t *ast, const NODE *node)
+{
+    VALUE obj;
+
+    obj = rb_ast_node_alloc(rb_cNode);
+    setup_node(obj, ast, node);
+
+    return obj;
+}
+
+static VALUE rb_ast_parse_str(VALUE str);
+static VALUE rb_ast_parse_file(VALUE path);
+static VALUE rb_ast_parse_array(VALUE array);
+
+static VALUE
+ast_parse_new(void)
+{
+    return rb_parser_set_context(rb_parser_new(), NULL, 0);
+}
+
+static VALUE
+ast_parse_done(rb_ast_t *ast)
+{
+    if (!ast->body.root) {
+        rb_ast_dispose(ast);
+        rb_exc_raise(GET_EC()->errinfo);
+    }
+
+    return ast_new_internal(ast, (NODE *)ast->body.root);
+}
+
+static VALUE
+ast_s_parse(rb_execution_context_t *ec, VALUE module, VALUE str)
+{
+    return rb_ast_parse_str(str);
+}
+
+static VALUE
+rb_ast_parse_str(VALUE str)
+{
+    rb_ast_t *ast = 0;
+
+    StringValue(str);
+    ast = rb_parser_compile_string_path(ast_parse_new(), Qnil, str, 1);
+    return ast_parse_done(ast);
+}
+
+static VALUE
+ast_s_parse_file(rb_execution_context_t *ec, VALUE module, VALUE path)
+{
+    return rb_ast_parse_file(path);
+}
+
+static VALUE
+rb_ast_parse_file(VALUE path)
+{
+    VALUE f;
+    rb_ast_t *ast = 0;
+    rb_encoding *enc = rb_utf8_encoding();
+
+    FilePathValue(path);
+    f = rb_file_open_str(path, "r");
+    rb_funcall(f, rb_intern("set_encoding"), 2, rb_enc_from_encoding(enc), rb_str_new_cstr("-"));
+    ast = rb_parser_compile_file_path(ast_parse_new(), Qnil, f, 1);
+    rb_io_close(f);
+    return ast_parse_done(ast);
+}
+
+static VALUE
+lex_array(VALUE array, int index)
+{
+    VALUE str = rb_ary_entry(array, index);
+    if (!NIL_P(str)) {
+        StringValue(str);
+        if (!rb_enc_asciicompat(rb_enc_get(str))) {
+            rb_raise(rb_eArgError, "invalid source encoding");
+        }
+    }
+    return str;
+}
+
+static VALUE
+rb_ast_parse_array(VALUE array)
+{
+    rb_ast_t *ast = 0;
+
+    array = rb_check_array_type(array);
+    ast = rb_parser_compile_generic(ast_parse_new(), lex_array, Qnil, array, 1);
+    return ast_parse_done(ast);
+}
+
+static VALUE node_children(rb_ast_t*, const NODE*);
+
+static VALUE
+node_find(VALUE self, const int node_id)
+{
+    VALUE ary;
+    long i;
+    struct ASTNodeData *data;
+    TypedData_Get_Struct(self, struct ASTNodeData, &rb_node_type, data);
+
+    if (nd_node_id(data->node) == node_id) return self;
+
+    ary = node_children(data->ast, data->node);
+
+    for (i = 0; i < RARRAY_LEN(ary); i++) {
+        VALUE child = RARRAY_AREF(ary, i);
+
+        if (CLASS_OF(child) == rb_cNode) {
+            VALUE result = node_find(child, node_id);
+            if (RTEST(result)) return result;
+        }
+    }
+
+    return Qnil;
+}
+
+extern VALUE rb_e_script;
+
+static VALUE
+script_lines(VALUE path)
+{
+    VALUE hash, lines;
+    ID script_lines;
+    CONST_ID(script_lines, "SCRIPT_LINES__");
+    if (!rb_const_defined_at(rb_cObject, script_lines)) return Qnil;
+    hash = rb_const_get_at(rb_cObject, script_lines);
+    if (!RB_TYPE_P(hash, T_HASH)) return Qnil;
+    lines = rb_hash_lookup(hash, path);
+    if (!RB_TYPE_P(lines, T_ARRAY)) return Qnil;
+    return lines;
+}
+
+static VALUE
+ast_s_of(rb_execution_context_t *ec, VALUE module, VALUE body)
+{
+    VALUE path, node, lines;
+    int node_id;
+    const rb_iseq_t *iseq = NULL;
+
+    if (rb_obj_is_proc(body)) {
+        iseq = vm_proc_iseq(body);
+
+        if (!rb_obj_is_iseq((VALUE)iseq)) {
+            iseq = NULL;
+        }
+    }
+    else {
+        iseq = rb_method_iseq(body);
+    }
+
+    if (!iseq) return Qnil;
+
+    path = rb_iseq_path(iseq);
+    node_id = iseq->body->location.node_id;
+    if (!NIL_P(lines = script_lines(path))) {
+        node = rb_ast_parse_array(lines);
+    }
+    else if (RSTRING_LEN(path) == 2 && memcmp(RSTRING_PTR(path), "-e", 2) == 0) {
+        node = rb_ast_parse_str(rb_e_script);
+    }
+    else {
+        node = rb_ast_parse_file(path);
+    }
+
+    return node_find(node, node_id);
+}
+
+static VALUE
+rb_ast_node_alloc(VALUE klass)
+{
+    struct ASTNodeData *data;
+    VALUE obj = TypedData_Make_Struct(klass, struct ASTNodeData, &rb_node_type, data);
+
+    return obj;
+}
+
+static const char*
+node_type_to_str(const NODE *node)
+{
+    return (ruby_node_name(nd_type(node)) + rb_strlen_lit("NODE_"));
+}
+
+static VALUE
+ast_node_type(rb_execution_context_t *ec, VALUE self)
+{
+    struct ASTNodeData *data;
+    TypedData_Get_Struct(self, struct ASTNodeData, &rb_node_type, data);
+
+    return rb_sym_intern_ascii_cstr(node_type_to_str(data->node));
+}
+
+#define NEW_CHILD(ast, node) node ? ast_new_internal(ast, node) : Qnil
+
+static VALUE
+rb_ary_new_from_node_args(rb_ast_t *ast, long n, ...)
+{
+    va_list ar;
+    VALUE ary;
+    long i;
+
+    ary = rb_ary_new2(n);
+
+    va_start(ar, n);
+    for (i=0; i<n; i++) {
+        NODE *node;
+        node = va_arg(ar, NODE *);
+        rb_ary_push(ary, NEW_CHILD(ast, node));
+    }
+    va_end(ar);
+    return ary;
+}
+
+static VALUE
+dump_block(rb_ast_t *ast, const NODE *node)
+{
+    VALUE ary = rb_ary_new();
+    do {
+        rb_ary_push(ary, NEW_CHILD(ast, node->nd_head));
+    } while (node->nd_next &&
+        nd_type(node->nd_next) == NODE_BLOCK &&
+        (node = node->nd_next, 1));
+    if (node->nd_next) {
+        rb_ary_push(ary, NEW_CHILD(ast, node->nd_next));
+    }
+
+    return ary;
+}
+
+static VALUE
+dump_array(rb_ast_t *ast, const NODE *node)
+{
+    VALUE ary = rb_ary_new();
+    rb_ary_push(ary, NEW_CHILD(ast, node->nd_head));
+
+    while (node->nd_next && nd_type(node->nd_next) == NODE_LIST) {
+        node = node->nd_next;
+        rb_ary_push(ary, NEW_CHILD(ast, node->nd_head));
+    }
+    rb_ary_push(ary, NEW_CHILD(ast, node->nd_next));
+
+    return ary;
+}
+
+static VALUE
+var_name(ID id)
+{
+    if (!id) return Qnil;
+    if (!rb_id2str(id)) return Qnil;
+    return ID2SYM(id);
+}
+
+static VALUE
+no_name_rest(void)
+{
+    ID rest;
+    CONST_ID(rest, "NODE_SPECIAL_NO_NAME_REST");
+    return ID2SYM(rest);
+}
+
+static VALUE
+rest_arg(rb_ast_t *ast, const NODE *rest_arg)
+{
+    return NODE_NAMED_REST_P(rest_arg) ? NEW_CHILD(ast, rest_arg) : no_name_rest();
+}
+
+static VALUE
+node_children(rb_ast_t *ast, const NODE *node)
+{
+    char name[DECIMAL_SIZE_OF_BITS(sizeof(long) * CHAR_BIT) + 2]; /* including '$' */
+
+    enum node_type type = nd_type(node);
+    switch (type) {
+      case NODE_BLOCK:
+        return dump_block(ast, node);
+      case NODE_IF:
+        return rb_ary_new_from_node_args(ast, 3, node->nd_cond, node->nd_body, node->nd_else);
+      case NODE_UNLESS:
+        return rb_ary_new_from_node_args(ast, 3, node->nd_cond, node->nd_body, node->nd_else);
+      case NODE_CASE:
+        return rb_ary_new_from_node_args(ast, 2, node->nd_head, node->nd_body);
+      case NODE_CASE2:
+        return rb_ary_new_from_node_args(ast, 2, node->nd_head, node->nd_body);
+      case NODE_CASE3:
+        return rb_ary_new_from_node_args(ast, 2, node->nd_head, node->nd_body);
+      case NODE_WHEN:
+        return rb_ary_new_from_node_args(ast, 3, node->nd_head, node->nd_body, node->nd_next);
+      case NODE_IN:
+        return rb_ary_new_from_node_args(ast, 3, node->nd_head, node->nd_body, node->nd_next);
+      case NODE_WHILE:
+      case NODE_UNTIL:
+        return rb_ary_push(rb_ary_new_from_node_args(ast, 2, node->nd_cond, node->nd_body),
+                           (node->nd_state ? Qtrue : Qfalse));
+      case NODE_ITER:
+      case NODE_FOR:
+        return rb_ary_new_from_node_args(ast, 2, node->nd_iter, node->nd_body);
+      case NODE_FOR_MASGN:
+        return rb_ary_new_from_node_args(ast, 1, node->nd_var);
+      case NODE_BREAK:
+      case NODE_NEXT:
+      case NODE_RETURN:
+        return rb_ary_new_from_node_args(ast, 1, node->nd_stts);
+      case NODE_REDO:
+        return rb_ary_new_from_node_args(ast, 0);
+      case NODE_RETRY:
+        return rb_ary_new_from_node_args(ast, 0);
+      case NODE_BEGIN:
+        return rb_ary_new_from_node_args(ast, 1, node->nd_body);
+      case NODE_RESCUE:
+        return rb_ary_new_from_node_args(ast, 3, node->nd_head, node->nd_resq, node->nd_else);
+      case NODE_RESBODY:
+        return rb_ary_new_from_node_args(ast, 3, node->nd_args, node->nd_body, node->nd_head);
+      case NODE_ENSURE:
+        return rb_ary_new_from_node_args(ast, 2, node->nd_head, node->nd_ensr);
+      case NODE_AND:
+      case NODE_OR:
+        {
+            VALUE ary = rb_ary_new();
+
+            while (1) {
+                rb_ary_push(ary, NEW_CHILD(ast, node->nd_1st));
+                if (!node->nd_2nd || nd_type(node->nd_2nd) != (int)type)
+                    break;
+                node = node->nd_2nd;
+            }
+            rb_ary_push(ary, NEW_CHILD(ast, node->nd_2nd));
+            return ary;
+        }
+      case NODE_MASGN:
+        if (NODE_NAMED_REST_P(node->nd_args)) {
+            return rb_ary_new_from_node_args(ast, 3, node->nd_value, node->nd_head, node->nd_args);
+        }
+        else {
+            return rb_ary_new_from_args(3, NEW_CHILD(ast, node->nd_value),
+                                        NEW_CHILD(ast, node->nd_head),
+                                        no_name_rest());
+        }
+      case NODE_LASGN:
+      case NODE_DASGN:
+      case NODE_DASGN_CURR:
+      case NODE_IASGN:
+      case NODE_CVASGN:
+      case NODE_GASGN:
+        if (NODE_REQUIRED_KEYWORD_P(node)) {
+            return rb_ary_new_from_args(2, var_name(node->nd_vid), ID2SYM(rb_intern("NODE_SPECIAL_REQUIRED_KEYWORD")));
+        }
+        return rb_ary_new_from_args(2, var_name(node->nd_vid), NEW_CHILD(ast, node->nd_value));
+      case NODE_CDECL:
+        if (node->nd_vid) {
+            return rb_ary_new_from_args(2, ID2SYM(node->nd_vid), NEW_CHILD(ast, node->nd_value));
+        }
+        return rb_ary_new_from_args(3, NEW_CHILD(ast, node->nd_else), ID2SYM(node->nd_else->nd_mid), NEW_CHILD(ast, node->nd_value));
+      case NODE_OP_ASGN1:
+        return rb_ary_new_from_args(4, NEW_CHILD(ast, node->nd_recv),
+                                    ID2SYM(node->nd_mid),
+                                    NEW_CHILD(ast, node->nd_args->nd_head),
+                                    NEW_CHILD(ast, node->nd_args->nd_body));
+      case NODE_OP_ASGN2:
+        return rb_ary_new_from_args(5, NEW_CHILD(ast, node->nd_recv),
+                                    node->nd_next->nd_aid ? Qtrue : Qfalse,
+                                    ID2SYM(node->nd_next->nd_vid),
+                                    ID2SYM(node->nd_next->nd_mid),
+                                    NEW_CHILD(ast, node->nd_value));
+      case NODE_OP_ASGN_AND:
+        return rb_ary_new_from_args(3, NEW_CHILD(ast, node->nd_head), ID2SYM(idANDOP),
+                                    NEW_CHILD(ast, node->nd_value));
+      case NODE_OP_ASGN_OR:
+        return rb_ary_new_from_args(3, NEW_CHILD(ast, node->nd_head), ID2SYM(idOROP),
+                                    NEW_CHILD(ast, node->nd_value));
+      case NODE_OP_CDECL:
+        return rb_ary_new_from_args(3, NEW_CHILD(ast, node->nd_head),
+                                    ID2SYM(node->nd_aid),
+                                    NEW_CHILD(ast, node->nd_value));
+      case NODE_CALL:
+      case NODE_OPCALL:
+      case NODE_QCALL:
+        return rb_ary_new_from_args(3, NEW_CHILD(ast, node->nd_recv),
+                                    ID2SYM(node->nd_mid),
+                                    NEW_CHILD(ast, node->nd_args));
+      case NODE_FCALL:
+        return rb_ary_new_from_args(2, ID2SYM(node->nd_mid),
+                                    NEW_CHILD(ast, node->nd_args));
+      case NODE_VCALL:
+        return rb_ary_new_from_args(1, ID2SYM(node->nd_mid));
+      case NODE_SUPER:
+        return rb_ary_new_from_node_args(ast, 1, node->nd_args);
+      case NODE_ZSUPER:
+        return rb_ary_new_from_node_args(ast, 0);
+      case NODE_LIST:
+      case NODE_VALUES:
+        return dump_array(ast, node);
+      case NODE_ZLIST:
+        return rb_ary_new_from_node_args(ast, 0);
+      case NODE_HASH:
+        return rb_ary_new_from_node_args(ast, 1, node->nd_head);
+      case NODE_YIELD:
+        return rb_ary_new_from_node_args(ast, 1, node->nd_head);
+      case NODE_LVAR:
+      case NODE_DVAR:
+        return rb_ary_new_from_args(1, var_name(node->nd_vid));
+      case NODE_IVAR:
+      case NODE_CONST:
+      case NODE_CVAR:
+      case NODE_GVAR:
+        return rb_ary_new_from_args(1, ID2SYM(node->nd_vid));
+      case NODE_NTH_REF:
+        snprintf(name, sizeof(name), "$%ld", node->nd_nth);
+        return rb_ary_new_from_args(1, ID2SYM(rb_intern(name)));
+      case NODE_BACK_REF:
+        name[0] = '$';
+        name[1] = (char)node->nd_nth;
+        name[2] = '\0';
+        return rb_ary_new_from_args(1, ID2SYM(rb_intern(name)));
+      case NODE_MATCH2:
+        if (node->nd_args) {
+            return rb_ary_new_from_node_args(ast, 3, node->nd_recv, node->nd_value, node->nd_args);
+        }
+        return rb_ary_new_from_node_args(ast, 2, node->nd_recv, node->nd_value);
+      case NODE_MATCH3:
+        return rb_ary_new_from_node_args(ast, 2, node->nd_recv, node->nd_value);
+      case NODE_MATCH:
+      case NODE_LIT:
+      case NODE_STR:
+      case NODE_XSTR:
+        return rb_ary_new_from_args(1, node->nd_lit);
+      case NODE_ONCE:
+        return rb_ary_new_from_node_args(ast, 1, node->nd_body);
+      case NODE_DSTR:
+      case NODE_DXSTR:
+      case NODE_DREGX:
+      case NODE_DSYM:
+        {
+            NODE *n = node->nd_next;
+            VALUE head = Qnil, next = Qnil;
+            if (n) {
+                head = NEW_CHILD(ast, n->nd_head);
+                next = NEW_CHILD(ast, n->nd_next);
+            }
+            return rb_ary_new_from_args(3, node->nd_lit, head, next);
+        }
+      case NODE_EVSTR:
+        return rb_ary_new_from_node_args(ast, 1, node->nd_body);
+      case NODE_ARGSCAT:
+        return rb_ary_new_from_node_args(ast, 2, node->nd_head, node->nd_body);
+      case NODE_ARGSPUSH:
+        return rb_ary_new_from_node_args(ast, 2, node->nd_head, node->nd_body);
+      case NODE_SPLAT:
+        return rb_ary_new_from_node_args(ast, 1, node->nd_head);
+      case NODE_BLOCK_PASS:
+        return rb_ary_new_from_node_args(ast, 2, node->nd_head, node->nd_body);
+      case NODE_DEFN:
+        return rb_ary_new_from_args(2, ID2SYM(node->nd_mid), NEW_CHILD(ast, node->nd_defn));
+      case NODE_DEFS:
+        return rb_ary_new_from_args(3, NEW_CHILD(ast, node->nd_recv), ID2SYM(node->nd_mid), NEW_CHILD(ast, node->nd_defn));
+      case NODE_ALIAS:
+        return rb_ary_new_from_node_args(ast, 2, node->nd_1st, node->nd_2nd);
+      case NODE_VALIAS:
+        return rb_ary_new_from_args(2, ID2SYM(node->nd_alias), ID2SYM(node->nd_orig));
+      case NODE_UNDEF:
+        return rb_ary_new_from_node_args(ast, 1, node->nd_undef);
+      case NODE_CLASS:
+        return rb_ary_new_from_node_args(ast, 3, node->nd_cpath, node->nd_super, node->nd_body);
+      case NODE_MODULE:
+        return rb_ary_new_from_node_args(ast, 2, node->nd_cpath, node->nd_body);
+      case NODE_SCLASS:
+        return rb_ary_new_from_node_args(ast, 2, node->nd_recv, node->nd_body);
+      case NODE_COLON2:
+        return rb_ary_new_from_args(2, NEW_CHILD(ast, node->nd_head), ID2SYM(node->nd_mid));
+      case NODE_COLON3:
+        return rb_ary_new_from_args(1, ID2SYM(node->nd_mid));
+      case NODE_DOT2:
+      case NODE_DOT3:
+      case NODE_FLIP2:
+      case NODE_FLIP3:
+        return rb_ary_new_from_node_args(ast, 2, node->nd_beg, node->nd_end);
+      case NODE_SELF:
+        return rb_ary_new_from_node_args(ast, 0);
+      case NODE_NIL:
+        return rb_ary_new_from_node_args(ast, 0);
+      case NODE_TRUE:
+        return rb_ary_new_from_node_args(ast, 0);
+      case NODE_FALSE:
+        return rb_ary_new_from_node_args(ast, 0);
+      case NODE_ERRINFO:
+        return rb_ary_new_from_node_args(ast, 0);
+      case NODE_DEFINED:
+        return rb_ary_new_from_node_args(ast, 1, node->nd_head);
+      case NODE_POSTEXE:
+        return rb_ary_new_from_node_args(ast, 1, node->nd_body);
+      case NODE_ATTRASGN:
+        return rb_ary_new_from_args(3, NEW_CHILD(ast, node->nd_recv), ID2SYM(node->nd_mid), NEW_CHILD(ast, node->nd_args));
+      case NODE_LAMBDA:
+        return rb_ary_new_from_node_args(ast, 1, node->nd_body);
+      case NODE_OPT_ARG:
+        return rb_ary_new_from_node_args(ast, 2, node->nd_body, node->nd_next);
+      case NODE_KW_ARG:
+        return rb_ary_new_from_node_args(ast, 2, node->nd_body, node->nd_next);
+      case NODE_POSTARG:
+        if (NODE_NAMED_REST_P(node->nd_1st)) {
+            return rb_ary_new_from_node_args(ast, 2, node->nd_1st, node->nd_2nd);
+        }
+        return rb_ary_new_from_args(2, no_name_rest(),
+                                    NEW_CHILD(ast, node->nd_2nd));
+      case NODE_ARGS:
+        {
+            struct rb_args_info *ainfo = node->nd_ainfo;
+            return rb_ary_new_from_args(10,
+                                        INT2NUM(ainfo->pre_args_num),
+                                        NEW_CHILD(ast, ainfo->pre_init),
+                                        NEW_CHILD(ast, ainfo->opt_args),
+                                        var_name(ainfo->first_post_arg),
+                                        INT2NUM(ainfo->post_args_num),
+                                        NEW_CHILD(ast, ainfo->post_init),
+                                        (ainfo->rest_arg == NODE_SPECIAL_EXCESSIVE_COMMA
+                                            ? ID2SYM(rb_intern("NODE_SPECIAL_EXCESSIVE_COMMA"))
+                                            : var_name(ainfo->rest_arg)),
+                                        (ainfo->no_kwarg ? Qfalse : NEW_CHILD(ast, ainfo->kw_args)),
+                                        (ainfo->no_kwarg ? Qfalse : NEW_CHILD(ast, ainfo->kw_rest_arg)),
+                                        var_name(ainfo->block_arg));
+        }
+      case NODE_SCOPE:
+        {
+            ID *tbl = node->nd_tbl;
+            int i, size = tbl ? (int)*tbl++ : 0;
+            VALUE locals = rb_ary_new_capa(size);
+            for (i = 0; i < size; i++) {
+                rb_ary_push(locals, var_name(tbl[i]));
+            }
+            return rb_ary_new_from_args(3, locals, NEW_CHILD(ast, node->nd_args), NEW_CHILD(ast, node->nd_body));
+        }
+      case NODE_ARYPTN:
+        {
+            struct rb_ary_pattern_info *apinfo = node->nd_apinfo;
+            VALUE rest = rest_arg(ast, apinfo->rest_arg);
+            return rb_ary_new_from_args(4,
+                                        NEW_CHILD(ast, node->nd_pconst),
+                                        NEW_CHILD(ast, apinfo->pre_args),
+                                        rest,
+                                        NEW_CHILD(ast, apinfo->post_args));
+        }
+      case NODE_FNDPTN:
+        {
+            struct rb_fnd_pattern_info *fpinfo = node->nd_fpinfo;
+            VALUE pre_rest = rest_arg(ast, fpinfo->pre_rest_arg);
+            VALUE post_rest = rest_arg(ast, fpinfo->post_rest_arg);
+            return rb_ary_new_from_args(4,
+                                        NEW_CHILD(ast, node->nd_pconst),
+                                        pre_rest,
+                                        NEW_CHILD(ast, fpinfo->args),
+                                        post_rest);
+        }
+      case NODE_HSHPTN:
+        {
+            VALUE kwrest = node->nd_pkwrestarg == NODE_SPECIAL_NO_REST_KEYWORD ? ID2SYM(rb_intern("NODE_SPECIAL_NO_REST_KEYWORD")) :
+                                                                                 NEW_CHILD(ast, node->nd_pkwrestarg);
+
+            return rb_ary_new_from_args(3,
+                                        NEW_CHILD(ast, node->nd_pconst),
+                                        NEW_CHILD(ast, node->nd_pkwargs),
+                                        kwrest);
+        }
+      case NODE_ARGS_AUX:
+      case NODE_LAST:
+        break;
+    }
+
+    rb_bug("node_children: unknown node: %s", ruby_node_name(type));
+}
+
+static VALUE
+ast_node_children(rb_execution_context_t *ec, VALUE self)
+{
+    struct ASTNodeData *data;
+    TypedData_Get_Struct(self, struct ASTNodeData, &rb_node_type, data);
+
+    return node_children(data->ast, data->node);
+}
+
+static VALUE
+ast_node_first_lineno(rb_execution_context_t *ec, VALUE self)
+{
+    struct ASTNodeData *data;
+    TypedData_Get_Struct(self, struct ASTNodeData, &rb_node_type, data);
+
+    return INT2NUM(nd_first_lineno(data->node));
+}
+
+static VALUE
+ast_node_first_column(rb_execution_context_t *ec, VALUE self)
+{
+    struct ASTNodeData *data;
+    TypedData_Get_Struct(self, struct ASTNodeData, &rb_node_type, data);
+
+    return INT2NUM(nd_first_column(data->node));
+}
+
+static VALUE
+ast_node_last_lineno(rb_execution_context_t *ec, VALUE self)
+{
+    struct ASTNodeData *data;
+    TypedData_Get_Struct(self, struct ASTNodeData, &rb_node_type, data);
+
+    return INT2NUM(nd_last_lineno(data->node));
+}
+
+static VALUE
+ast_node_last_column(rb_execution_context_t *ec, VALUE self)
+{
+    struct ASTNodeData *data;
+    TypedData_Get_Struct(self, struct ASTNodeData, &rb_node_type, data);
+
+    return INT2NUM(nd_last_column(data->node));
+}
+
+static VALUE
+ast_node_inspect(rb_execution_context_t *ec, VALUE self)
+{
+    VALUE str;
+    VALUE cname;
+    struct ASTNodeData *data;
+    TypedData_Get_Struct(self, struct ASTNodeData, &rb_node_type, data);
+
+    cname = rb_class_path(rb_obj_class(self));
+    str = rb_str_new2("#<");
+
+    rb_str_append(str, cname);
+    rb_str_catf(str, ":%s@%d:%d-%d:%d>",
+                node_type_to_str(data->node),
+                nd_first_lineno(data->node), nd_first_column(data->node),
+                nd_last_lineno(data->node), nd_last_column(data->node));
+
+    return str;
+}
+
+#include "ast.rbinc"
+
+void
+Init_ast(void)
+{
+    rb_mAST = rb_define_module_under(rb_cRubyVM, "AbstractSyntaxTree");
+    rb_cNode = rb_define_class_under(rb_mAST, "Node", rb_cObject);
+    rb_undef_alloc_func(rb_cNode);
+}
diff --git a/ast.rb b/ast.rb
new file mode 100644
index 0000000000..34fa645671
--- /dev/null
+++ b/ast.rb
@@ -0,0 +1,146 @@
+# for ast.c
+
+class RubyVM
+
+  # AbstractSyntaxTree provides methods to parse Ruby code into
+  # abstract syntax trees. The nodes in the tree
+  # are instances of RubyVM::AbstractSyntaxTree::Node.
+  #
+  # This module is MRI specific as it exposes implementation details
+  # of the MRI abstract syntax tree.
+  #
+  # This module is experimental and its API is not stable, therefore it might
+  # change without notice. As examples, the order of children nodes is not
+  # guaranteed, the number of children nodes might change, there is no way to
+  # access children nodes by name, etc.
+  #
+  # If you are looking for a stable API or an API working under multiple Ruby
+  # implementations, consider using the _parser_ gem or Ripper. If you would
+  # like to make RubyVM::AbstractSyntaxTree stable, please join the discussion
+  # at https://bugs.ruby-lang.org/issues/14844.
+  #
+  module AbstractSyntaxTree
+
+    #  call-seq:
+    #     RubyVM::AbstractSyntaxTree.parse(string) -> RubyVM::AbstractSyntaxTree::Node
+    #
+    #  Parses the given _string_ into an abstract syntax tree,
+    #  returning the root node of that tree.
+    #
+    #  SyntaxError is raised if the given _string_ is invalid syntax.
+    #
+    #    RubyVM::AbstractSyntaxTree.parse("x = 1 + 2")
+    #    # => #<RubyVM::AbstractSyntaxTree::Node:SCOPE@1:0-1:9>
+    def self.parse string
+      Primitive.ast_s_parse string
+    end
+
+    #  call-seq:
+    #     RubyVM::AbstractSyntaxTree.parse_file(pathname) -> RubyVM::AbstractSyntaxTree::Node
+    #
+    #   Reads the file from _pathname_, then parses it like ::parse,
+    #   returning the root node of the abstract syntax tree.
+    #
+    #   SyntaxError is raised if _pathname_'s contents are not
+    #   valid Ruby syntax.
+    #
+    #     RubyVM::AbstractSyntaxTree.parse_file("my-app/app.rb")
+    #     # => #<RubyVM::AbstractSyntaxTree::Node:SCOPE@1:0-31:3>
+    def self.parse_file pathname
+      Primitive.ast_s_parse_file pathname
+    end
+
+    #  call-seq:
+    #     RubyVM::AbstractSyntaxTree.of(proc)   -> RubyVM::AbstractSyntaxTree::Node
+    #     RubyVM::AbstractSyntaxTree.of(method) -> RubyVM::AbstractSyntaxTree::Node
+    #
+    #   Returns AST nodes of the given _proc_ or _method_.
+    #
+    #     RubyVM::AbstractSyntaxTree.of(proc {1 + 2})
+    #     # => #<RubyVM::AbstractSyntaxTree::Node:SCOPE@1:35-1:42>
+    #
+    #     def hello
+    #       puts "hello, world"
+    #     end
+    #
+    #     RubyVM::AbstractSyntaxTree.of(method(:hello))
+    #     # => #<RubyVM::AbstractSyntaxTree::Node:SCOPE@1:0-3:3>
+    def self.of body
+      Primitive.ast_s_of body
+    end
+
+    # RubyVM::AbstractSyntaxTree::Node instances are created by parse methods in
+    # RubyVM::AbstractSyntaxTree.
+    #
+    # This class is MRI specific.
+    #
+    class Node
+
+      #  call-seq:
+      #     node.type -> symbol
+      #
+      #  Returns the type of this node as a symbol.
+      #
+      #    root = RubyVM::AbstractSyntaxTree.parse("x = 1 + 2")
+      #    root.type # => :SCOPE
+      #    lasgn = root.children[2]
+      #    lasgn.type # => :LASGN
+      #    call = lasgn.children[1]
+      #    call.type # => :OPCALL
+      def type
+        Primitive.ast_node_type
+      end
+
+      #  call-seq:
+      #     node.first_lineno -> integer
+      #
+      #  The line number in the source code where this AST's text began.
+      def first_lineno
+        Primitive.ast_node_first_lineno
+      end
+
+      #  call-seq:
+      #     node.first_column -> integer
+      #
+      #  The column number in the source code where this AST's text began.
+      def first_column
+        Primitive.ast_node_first_column
+      end
+
+      #  call-seq:
+      #     node.last_lineno -> integer
+      #
+      #  The line number in the source code where this AST's text ended.
+      def last_lineno
+        Primitive.ast_node_last_lineno
+      end
+
+      #  call-seq:
+      #     node.last_column -> integer
+      #
+      #  The column number in the source code where this AST's text ended.
+      def last_column
+        Primitive.ast_node_last_column
+      end
+
+      #  call-seq:
+      #     node.children -> array
+      #
+      #  Returns AST nodes under this one.  Each kind of node
+      #  has different children, depending on what kind of node it is.
+      #
+      #  The returned array may contain other nodes or <code>nil</code>.
+      def children
+        Primitive.ast_node_children
+      end
+
+      #  call-seq:
+      #     node.inspect -> string
+      #
+      #  Returns debugging information about this node as a string.
+      def inspect
+        Primitive.ast_node_inspect
+      end
+    end
+  end
+end
diff --git a/autogen.sh b/autogen.sh
new file mode 100755
index 0000000000..44a1922cb0
--- /dev/null
+++ b/autogen.sh
@@ -0,0 +1,9 @@
+#!/bin/sh
+
+PWD=
+case "$0" in
+*/*) srcdir=`dirname $0`;;
+*) srcdir="";;
+esac
+
+exec ${AUTORECONF:-autoreconf} --install --symlink "$@" ${srcdir:+"$srcdir"}
diff --git a/basictest/runner.rb b/basictest/runner.rb
new file mode 100755
index 0000000000..0f398e7acc
--- /dev/null
+++ b/basictest/runner.rb
@@ -0,0 +1,33 @@
+#! ./miniruby
+
+exit if defined?(CROSS_COMPILING) and CROSS_COMPILING
+ruby = ENV["RUBY"]
+unless ruby
+  load './rbconfig.rb'
+  ruby = "./#{RbConfig::CONFIG['ruby_install_name']}#{RbConfig::CONFIG['EXEEXT']}"
+end
+unless File.exist? ruby
+  print "#{ruby} is not found.\n"
+  print "Try `make' first, then `make test', please.\n"
+  exit false
+end
+ARGV[0] and opt = ARGV[0][/\A--run-opt=(.*)/, 1] and ARGV.shift
+
+$stderr.reopen($stdout)
+error = ''
+
+srcdir = File.expand_path('..', File.dirname(__FILE__))
+if env = ENV["RUBYOPT"]
+  ENV["RUBYOPT"] = env + " -W1"
+end
+`#{ruby} #{opt} -W1 #{srcdir}/basictest/test.rb #{ARGV.join(' ')}`.each_line do |line|
+  if line =~ /^end of test/
+    print "\ntest succeeded\n"
+    exit true
+  end
+  error << line if %r:^(basictest/test.rb|not): =~ line
+end
+puts
+print error
+print "test failed\n"
+exit false
diff --git a/basictest/test.rb b/basictest/test.rb
new file mode 100755
index 0000000000..52008b78db
--- /dev/null
+++ b/basictest/test.rb
@@ -0,0 +1,2364 @@
+#! /usr/bin/env ruby
+# -*- coding: us-ascii -*-
+
+$testnum=0
+$ntest=0
+$failed = 0
+class Progress
+  def initialize
+    @color = nil
+    @tty = nil
+    @quiet = nil
+    @verbose = nil
+    ARGV.each do |arg|
+      case arg
+      when /\A--color(?:=(?:always|(auto)|(never)|(.*)))?\z/
+        warn "unknown --color argument: #$3" if $3
+        @color = $1 ? nil : !$2
+      when /\A--tty(=(?:yes|(no)|(.*)))?\z/
+        warn "unknown --tty argument: #$3" if $3
+        @tty = !$1 || !$2
+        true
+      when /\A-(q|-quiet)\z/
+        @quiet = true
+      when /\A-(v|-verbose)\z/
+        @verbose = true
+      end
+    end
+    @tty = STDERR.tty? && !STDOUT.tty? && /dumb/ !~ ENV["TERM"] if @tty.nil?
+    @eol = @tty && !@verbose ? "\r\e[K\r" : "\n"
+    case @color
+    when nil
+      @color = @tty
+    end
+    if @color
+      # dircolors-like style
+      colors = (colors = ENV['TEST_COLORS']) ? Hash[colors.scan(/(\w+)=([^:\n]*)/)] : {}
+      begin
+        File.read(File.join(__dir__, "../tool/colors")).scan(/(\w+)=([^:\n]*)/) do |n, c|
+          colors[n] ||= c
+        end
+      rescue
+      end
+      @passed = "\e[;#{colors["pass"] || "32"}m"
+      @failed = "\e[;#{colors["fail"] || "31"}m"
+      @reset = "\e[m"
+    else
+      @passed = @failed = @reset = ""
+    end
+    extend(Rotator) if @tty
+  end
+
+  def passed_string
+    "."
+  end
+  def failed_string
+    "#{@failed}F#{@reset}"
+  end
+  def init_string
+  end
+  def finish_string
+    if @quiet
+      @eol
+    else
+      "#{@passed}#{@ok ? 'OK' : ''} #{$testnum}#{@reset}#{@eol}"
+    end
+  end
+  def pass
+    STDERR.print passed_string
+  end
+  def fail
+    @ok = false
+    STDERR.print failed_string
+  end
+  def init
+    @ok = true
+    STDERR.print init_string
+  end
+  def finish
+    STDERR.print finish_string
+  end
+
+  module Rotator
+    ROTATOR = %w[- \\ | /]
+    BS = "\b" * ROTATOR[0].size
+    def passed_string
+      "#{BS}#{ROTATOR[(@count += 1) % ROTATOR.size]}"
+    end
+    def failed_string
+      "#{BS}#{super}#{ROTATOR[@count % ROTATOR.size]}"
+    end
+    def init_string
+      @count = 0
+      " "
+    end
+    def finish_string
+      s = "#{BS}#{' ' * BS.size}#{BS}#{super}"
+      s.gsub!(/\n/, "\r\e[2K\r") if @quiet
+      s
+    end
+  end
+end
+PROGRESS = Progress.new
+
+def test_check(what)
+  unless $ntest.zero?
+    PROGRESS.finish
+  end
+  STDERR.print "#{$0}:#{what} "
+  PROGRESS.init
+  $what = what
+  $testnum = 0
+end
+
+def test_ok(cond,n=1)
+  $testnum+=1
+  $ntest+=1
+  where = (st = caller(n)) ? st[0] : "caller error! (n=#{n}, trace=#{caller(0).join(', ')}"
+  if cond
+    PROGRESS.pass
+    printf "ok %d (%s)\n", $testnum, where
+  else
+    PROGRESS.fail
+    printf "not ok %s %d -- %s\n", $what, $testnum, where
+    $failed+=1
+  end
+  STDOUT.flush
+  STDERR.flush
+end
+
+# make sure conditional operators work
+
+test_check "assignment"
+
+a=[]; a[0] ||= "bar";
+test_ok(a[0] == "bar")
+h={}; h["foo"] ||= "bar";
+test_ok(h["foo"] == "bar")
+
+aa = 5
+aa ||= 25
+test_ok(aa == 5)
+bb ||= 25
+test_ok(bb == 25)
+cc &&=33
+test_ok(cc == nil)
+cc = 5
+cc &&=44
+test_ok(cc == 44)
+
+a = nil; test_ok(a == nil)
+a = 1; test_ok(a == 1)
+a = []; test_ok(a == [])
+a = [1]; test_ok(a == [1])
+a = [nil]; test_ok(a == [nil])
+a = [[]]; test_ok(a == [[]])
+a = [1,2]; test_ok(a == [1,2])
+a = [*[]]; test_ok(a == [])
+a = [*[1]]; test_ok(a == [1])
+a = [*[1,2]]; test_ok(a == [1,2])
+
+a = *[]; test_ok(a == [])
+a = *[1]; test_ok(a == [1])
+a = *[nil]; test_ok(a == [nil])
+a = *[[]]; test_ok(a == [[]])
+a = *[1,2]; test_ok(a == [1,2])
+a = *[*[]]; test_ok(a == [])
+a = *[*[1]]; test_ok(a == [1])
+a = *[*[1,2]]; test_ok(a == [1,2])
+
+a, = nil; test_ok(a == nil)
+a, = 1; test_ok(a == 1)
+a, = []; test_ok(a == nil)
+a, = [1]; test_ok(a == 1)
+a, = [nil]; test_ok(a == nil)
+a, = [[]]; test_ok(a == [])
+a, = 1,2; test_ok(a == 1)
+a, = [1,2]; test_ok(a == 1)
+a, = [*[]]; test_ok(a == nil)
+a, = [*[1]]; test_ok(a == 1)
+a, = *[1,2]; test_ok(a == 1)
+a, = [*[1,2]]; test_ok(a == 1)
+
+a, = *[]; test_ok(a == nil)
+a, = *[1]; test_ok(a == 1)
+a, = *[nil]; test_ok(a == nil)
+a, = *[[]]; test_ok(a == [])
+a, = *[1,2]; test_ok(a == 1)
+a, = *[*[]]; test_ok(a == nil)
+a, = *[*[1]]; test_ok(a == 1)
+a, = *[*[1,2]]; test_ok(a == 1)
+
+*a = nil; test_ok(a == [nil])
+*a = 1; test_ok(a == [1])
+*a = []; test_ok(a == [])
+*a = [1]; test_ok(a == [1])
+*a = [nil]; test_ok(a == [nil])
+*a = [[]]; test_ok(a == [[]])
+*a = [1,2]; test_ok(a == [1,2])
+*a = [*[]]; test_ok(a == [])
+*a = [*[1]]; test_ok(a == [1])
+*a = [*[1,2]]; test_ok(a == [1,2])
+
+*a = *[]; test_ok(a == [])
+*a = *[1]; test_ok(a == [1])
+*a = *[nil]; test_ok(a == [nil])
+*a = *[[]]; test_ok(a == [[]])
+*a = *[1,2]; test_ok(a == [1,2])
+*a = *[*[]]; test_ok(a == [])
+*a = *[*[1]]; test_ok(a == [1])
+*a = *[*[1,2]]; test_ok(a == [1,2])
+
+a,b,*c = nil; test_ok([a,b,c] == [nil,nil,[]])
+a,b,*c = 1; test_ok([a,b,c] == [1,nil,[]])
+a,b,*c = []; test_ok([a,b,c] == [nil,nil,[]])
+a,b,*c = [1]; test_ok([a,b,c] == [1,nil,[]])
+a,b,*c = [nil]; test_ok([a,b,c] == [nil,nil,[]])
+a,b,*c = [[]]; test_ok([a,b,c] == [[],nil,[]])
+a,b,*c = [1,2]; test_ok([a,b,c] == [1,2,[]])
+a,b,*c = [*[]]; test_ok([a,b,c] == [nil,nil,[]])
+a,b,*c = [*[1]]; test_ok([a,b,c] == [1,nil,[]])
+a,b,*c = [*[1,2]]; test_ok([a,b,c] == [1,2,[]])
+
+a,b,*c = *[]; test_ok([a,b,c] == [nil,nil,[]])
+a,b,*c = *[1]; test_ok([a,b,c] == [1,nil,[]])
+a,b,*c = *[nil]; test_ok([a,b,c] == [nil,nil,[]])
+a,b,*c = *[[]]; test_ok([a,b,c] == [[],nil,[]])
+a,b,*c = *[1,2]; test_ok([a,b,c] == [1,2,[]])
+a,b,*c = *[*[]]; test_ok([a,b,c] == [nil,nil,[]])
+a,b,*c = *[*[1]]; test_ok([a,b,c] == [1,nil,[]])
+a,b,*c = *[*[1,2]]; test_ok([a,b,c] == [1,2,[]])
+
+def f; yield nil; end; f {|a| test_ok(a == nil)}
+def f; yield 1; end; f {|a| test_ok(a == 1)}
+def f; yield []; end; f {|a| test_ok(a == [])}
+def f; yield [1]; end; f {|a| test_ok(a == [1])}
+def f; yield [nil]; end; f {|a| test_ok(a == [nil])}
+def f; yield [[]]; end; f {|a| test_ok(a == [[]])}
+def f; yield [*[]]; end; f {|a| test_ok(a == [])}
+def f; yield [*[1]]; end; f {|a| test_ok(a == [1])}
+def f; yield [*[1,2]]; end; f {|a| test_ok(a == [1,2])}
+def f; yield *[]; end; f {|a| test_ok(a == nil)}
+def f; yield *[1]; end; f {|a| test_ok(a == 1)}
+def f; yield *[nil]; end; f {|a| test_ok(a == nil)}
+def f; yield *[[]]; end; f {|a| test_ok(a == [])}
+def f; yield *[*[]]; end; f {|a| test_ok(a == nil)}
+def f; yield *[*[1]]; end; f {|a| test_ok(a == 1)}
+def f; yield *[*[1,2]]; end; f {|a| test_ok(a == 1)}
+
+def f; yield; end; f {|a,| test_ok(a == nil)}
+def f; yield nil; end; f {|a,| test_ok(a == nil)}
+def f; yield 1; end; f {|a,| test_ok(a == 1)}
+def f; yield []; end; f {|a,| test_ok(a == nil)}
+def f; yield [1]; end; f {|a,| test_ok(a == 1)}
+def f; yield [nil]; end; f {|a,| test_ok(a == nil)}
+def f; yield [[]]; end; f {|a,| test_ok(a == [])}
+def f; yield [*[]]; end; f {|a,| test_ok(a == nil)}
+def f; yield [*[1]]; end; f {|a,| test_ok(a == 1)}
+def f; yield [*[1,2]]; end; f {|a,| test_ok(a == 1)}
+
+def f; yield *[]; end; f {|a,| test_ok(a == nil)}
+def f; yield *[1]; end; f {|a,| test_ok(a == 1)}
+def f; yield *[nil]; end; f {|a,| test_ok(a == nil)}
+def f; yield *[[]]; end; f {|a,| test_ok(a == nil)}
+def f; yield *[*[]]; end; f {|a,| test_ok(a == nil)}
+def f; yield *[*[1]]; end; f {|a,| test_ok(a == 1)}
+def f; yield *[*[1,2]]; end; f {|a,| test_ok(a == 1)}
+
+def f; yield; end; f {|*a| test_ok(a == [])}
+def f; yield nil; end; f {|*a| test_ok(a == [nil])}
+def f; yield 1; end; f {|*a| test_ok(a == [1])}
+def f; yield []; end; f {|*a| test_ok(a == [[]])}
+def f; yield [1]; end; f {|*a| test_ok(a == [[1]])}
+def f; yield [nil]; end; f {|*a| test_ok(a == [[nil]])}
+def f; yield [[]]; end; f {|*a| test_ok(a == [[[]]])}
+def f; yield [1,2]; end; f {|*a| test_ok(a == [[1,2]])}
+def f; yield [*[]]; end; f {|*a| test_ok(a == [[]])}
+def f; yield [*[1]]; end; f {|*a| test_ok(a == [[1]])}
+def f; yield [*[1,2]]; end; f {|*a| test_ok(a == [[1,2]])}
+
+def f; yield *[]; end; f {|*a| test_ok(a == [])}
+def f; yield *[1]; end; f {|*a| test_ok(a == [1])}
+def f; yield *[nil]; end; f {|*a| test_ok(a == [nil])}
+def f; yield *[[]]; end; f {|*a| test_ok(a == [[]])}
+def f; yield *[*[]]; end; f {|*a| test_ok(a == [])}
+def f; yield *[*[1]]; end; f {|*a| test_ok(a == [1])}
+def f; yield *[*[1,2]]; end; f {|*a| test_ok(a == [1,2])}
+
+def f; yield; end; f {|a,b,*c| test_ok([a,b,c] == [nil,nil,[]])}
+def f; yield nil; end; f {|a,b,*c| test_ok([a,b,c] == [nil,nil,[]])}
+def f; yield 1; end; f {|a,b,*c| test_ok([a,b,c] == [1,nil,[]])}
+def f; yield []; end; f {|a,b,*c| test_ok([a,b,c] == [nil,nil,[]])}
+def f; yield [1]; end; f {|a,b,*c| test_ok([a,b,c] == [1,nil,[]])}
+def f; yield [nil]; end; f {|a,b,*c| test_ok([a,b,c] == [nil,nil,[]])}
+def f; yield [[]]; end; f {|a,b,*c| test_ok([a,b,c] == [[],nil,[]])}
+def f; yield [*[]]; end; f {|a,b,*c| test_ok([a,b,c] == [nil,nil,[]])}
+def f; yield [*[1]]; end; f {|a,b,*c| test_ok([a,b,c] == [1,nil,[]])}
+def f; yield [*[1,2]]; end; f {|a,b,*c| test_ok([a,b,c] == [1,2,[]])}
+
+def f; yield *[]; end; f {|a,b,*c| test_ok([a,b,c] == [nil,nil,[]])}
+def f; yield *[1]; end; f {|a,b,*c| test_ok([a,b,c] == [1,nil,[]])}
+def f; yield *[nil]; end; f {|a,b,*c| test_ok([a,b,c] == [nil,nil,[]])}
+def f; yield *[[]]; end; f {|a,b,*c| test_ok([a,b,c] == [nil,nil,[]])}
+def f; yield *[*[]]; end; f {|a,b,*c| test_ok([a,b,c] == [nil,nil,[]])}
+def f; yield *[*[1]]; end; f {|a,b,*c| test_ok([a,b,c] == [1,nil,[]])}
+def f; yield *[*[1,2]]; end; f {|a,b,*c| test_ok([a,b,c] == [1,2,[]])}
+
+def r; return; end; a = r(); test_ok(a == nil)
+def r; return nil; end; a = r(); test_ok(a == nil)
+def r; return 1; end; a = r(); test_ok(a == 1)
+def r; return []; end; a = r(); test_ok(a == [])
+def r; return [1]; end; a = r(); test_ok(a == [1])
+def r; return [nil]; end; a = r(); test_ok(a == [nil])
+def r; return [[]]; end; a = r(); test_ok(a == [[]])
+def r; return [*[]]; end; a = r(); test_ok(a == [])
+def r; return [*[1]]; end; a = r(); test_ok(a == [1])
+def r; return [*[1,2]]; end; a = r(); test_ok(a == [1,2])
+
+def r; return *[]; end; a = r(); test_ok(a == [])
+def r; return *[1]; end; a = r(); test_ok(a == [1])
+def r; return *[nil]; end; a = r(); test_ok(a == [nil])
+def r; return *[[]]; end; a = r(); test_ok(a == [[]])
+def r; return *[*[]]; end; a = r(); test_ok(a == [])
+def r; return *[*[1]]; end; a = r(); test_ok(a == [1])
+def r; return *[*[1,2]]; end; a = r(); test_ok(a == [1,2])
+
+def r; return *[[]]; end; a = *r(); test_ok(a == [[]])
+def r; return *[*[1,2]]; end; a = *r(); test_ok(a == [1,2])
+
+def r; return; end; *a = r(); test_ok(a == [nil])
+def r; return nil; end; *a = r(); test_ok(a == [nil])
+def r; return 1; end; *a = r(); test_ok(a == [1])
+def r; return []; end; *a = r(); test_ok(a == [])
+def r; return [1]; end; *a = r(); test_ok(a == [1])
+def r; return [nil]; end; *a = r(); test_ok(a == [nil])
+def r; return [[]]; end; *a = r(); test_ok(a == [[]])
+def r; return [1,2]; end; *a = r(); test_ok(a == [1,2])
+def r; return [*[]]; end; *a = r(); test_ok(a == [])
+def r; return [*[1]]; end; *a = r(); test_ok(a == [1])
+def r; return [*[1,2]]; end; *a = r(); test_ok(a == [1,2])
+
+def r; return *[]; end; *a = r(); test_ok(a == [])
+def r; return *[1]; end; *a = r(); test_ok(a == [1])
+def r; return *[nil]; end; *a = r(); test_ok(a == [nil])
+def r; return *[[]]; end; *a = r(); test_ok(a == [[]])
+def r; return *[1,2]; end; *a = r(); test_ok(a == [1,2])
+def r; return *[*[]]; end; *a = r(); test_ok(a == [])
+def r; return *[*[1]]; end; *a = r(); test_ok(a == [1])
+def r; return *[*[1,2]]; end; *a = r(); test_ok(a == [1,2])
+
+def r; return *[[]]; end; *a = *r(); test_ok(a == [[]])
+def r; return *[1,2]; end; *a = *r(); test_ok(a == [1,2])
+def r; return *[*[1,2]]; end; *a = *r(); test_ok(a == [1,2])
+
+def r; return; end; a,b,*c = r(); test_ok([a,b,c] == [nil,nil,[]])
+def r; return nil; end; a,b,*c = r(); test_ok([a,b,c] == [nil,nil,[]])
+def r; return 1; end; a,b,*c = r(); test_ok([a,b,c] == [1,nil,[]])
+def r; return []; end; a,b,*c = r(); test_ok([a,b,c] == [nil,nil,[]])
+def r; return [1]; end; a,b,*c = r(); test_ok([a,b,c] == [1,nil,[]])
+def r; return [nil]; end; a,b,*c = r(); test_ok([a,b,c] == [nil,nil,[]])
+def r; return [[]]; end; a,b,*c = r(); test_ok([a,b,c] == [[],nil,[]])
+def r; return [1,2]; end; a,b,*c = r(); test_ok([a,b,c] == [1,2,[]])
+def r; return [*[]]; end; a,b,*c = r(); test_ok([a,b,c] == [nil,nil,[]])
+def r; return [*[1]]; end; a,b,*c = r(); test_ok([a,b,c] == [1,nil,[]])
+def r; return [*[1,2]]; end; a,b,*c = r(); test_ok([a,b,c] == [1,2,[]])
+
+def r; return *[]; end; a,b,*c = r(); test_ok([a,b,c] == [nil,nil,[]])
+def r; return *[1]; end; a,b,*c = r(); test_ok([a,b,c] == [1,nil,[]])
+def r; return *[nil]; end; a,b,*c = r(); test_ok([a,b,c] == [nil,nil,[]])
+def r; return *[[]]; end; a,b,*c = r(); test_ok([a,b,c] == [[],nil,[]])
+def r; return *[1,2]; end; a,b,*c = r(); test_ok([a,b,c] == [1,2,[]])
+def r; return *[*[]]; end; a,b,*c = r(); test_ok([a,b,c] == [nil,nil,[]])
+def r; return *[*[1]]; end; a,b,*c = r(); test_ok([a,b,c] == [1,nil,[]])
+def r; return *[*[1,2]]; end; a,b,*c = r(); test_ok([a,b,c] == [1,2,[]])
+
+f = lambda {|r,| test_ok([] == r)}
+f.call([], *[])
+
+f = lambda {|r,*l| test_ok([] == r); test_ok([1] == l)}
+f.call([], *[1])
+
+f = lambda{|x| x}
+test_ok(f.call(42) == 42)
+test_ok(f.call([42]) == [42])
+test_ok(f.call([[42]]) == [[42]])
+test_ok(f.call([42,55]) == [42,55])
+
+f = lambda{|x,| x}
+test_ok(f.call(42) == 42)
+test_ok(f.call([42]) == [42])
+test_ok(f.call([[42]]) == [[42]])
+test_ok(f.call([42,55]) == [42,55])
+
+f = lambda{|*x| x}
+test_ok(f.call(42) == [42])
+test_ok(f.call([42]) == [[42]])
+test_ok(f.call([[42]]) == [[[42]]])
+test_ok(f.call([42,55]) == [[42,55]])
+test_ok(f.call(42,55) == [42,55])
+
+f = lambda { |a, b=42, *c| [a,b,c] }
+test_ok(f.call(1      ) == [1,42,[  ]] )
+test_ok(f.call(1,43   ) == [1,43,[  ]] )
+test_ok(f.call(1,43,44) == [1,43,[44]] )
+
+f = lambda { |a, b=(a|16), *c, &block| [a,b,c,block&&block[]] }
+test_ok(f.call(8      )     == [8,24,[  ],nil] )
+test_ok(f.call(8,43   )     == [8,43,[  ],nil] )
+test_ok(f.call(8,43,44)     == [8,43,[44],nil] )
+test_ok(f.call(8      ){45} == [8,24,[  ],45 ] )
+test_ok(f.call(8,43   ){45} == [8,43,[  ],45 ] )
+test_ok(f.call(8,43,44){45} == [8,43,[44],45 ] )
+
+f = lambda { |a, b=42, *c, d| [a,b,c,d] }
+test_ok(f.call(1      ,99) == [1,42,[  ],99] )
+test_ok(f.call(1,43   ,99) == [1,43,[  ],99] )
+test_ok(f.call(1,43,44,99) == [1,43,[44],99] )
+
+f = lambda { |a, b=(a|16), &block| [a,b,block&&block[]] }
+test_ok(f.call(8   )     == [8,24,nil] )
+test_ok(f.call(8,43)     == [8,43,nil] )
+test_ok(f.call(8,43)     == [8,43,nil] )
+test_ok(f.call(8   ){45} == [8,24,45 ] )
+test_ok(f.call(8,43){45} == [8,43,45 ] )
+test_ok(f.call(8,43){45} == [8,43,45 ] )
+
+f = lambda { |a, b=42, d| [a,b,d] }
+test_ok(f.call(1   ,99) == [1,42,99] )
+test_ok(f.call(1,43,99) == [1,43,99] )
+test_ok(f.call(1,43,99) == [1,43,99] )
+
+f = lambda { |b=42, *c, &block| [b,c,block&&block[]] }
+test_ok(f.call(     )     == [42,[  ],nil] )
+test_ok(f.call(43   )     == [43,[  ],nil] )
+test_ok(f.call(43,44)     == [43,[44],nil] )
+test_ok(f.call(     ){45} == [42,[  ],45 ] )
+test_ok(f.call(43   ){45} == [43,[  ],45 ] )
+test_ok(f.call(43,44){45} == [43,[44],45 ] )
+
+f = lambda { |b=42, *c, d| [b,c,d] }
+test_ok(f.call(      99) == [42,[  ],99] )
+test_ok(f.call(43   ,99) == [43,[  ],99] )
+test_ok(f.call(43,44,99) == [43,[44],99] )
+
+f = lambda { |b=42, &block| [b,block&&block[]] }
+test_ok(f.call(  )     == [42,nil] )
+test_ok(f.call(43)     == [43,nil] )
+test_ok(f.call(43)     == [43,nil] )
+test_ok(f.call(  ){45} == [42,45 ] )
+test_ok(f.call(43){45} == [43,45 ] )
+test_ok(f.call(43){45} == [43,45 ] )
+
+f = lambda { |b=42, d| [b,d] }
+test_ok(f.call(   99) == [42,99] )
+test_ok(f.call(43,99) == [43,99] )
+test_ok(f.call(43,99) == [43,99] )
+
+
+a,=*[1]
+test_ok(a == 1)
+a,=*[[1]]
+test_ok(a == [1])
+a,=*[[[1]]]
+test_ok(a == [[1]])
+
+x, (y, z) = 1, 2, 3
+test_ok([1,2,nil] == [x,y,z])
+x, (y, z) = 1, [2,3]
+test_ok([1,2,3] == [x,y,z])
+x, (y, z) = 1, [2]
+test_ok([1,2,nil] == [x,y,z])
+
+a = loop do break; end; test_ok(a == nil)
+a = loop do break nil; end; test_ok(a == nil)
+a = loop do break 1; end; test_ok(a == 1)
+a = loop do break []; end; test_ok(a == [])
+a = loop do break [1]; end; test_ok(a == [1])
+a = loop do break [nil]; end; test_ok(a == [nil])
+a = loop do break [[]]; end; test_ok(a == [[]])
+a = loop do break [*[]]; end; test_ok(a == [])
+a = loop do break [*[1]]; end; test_ok(a == [1])
+a = loop do break [*[1,2]]; end; test_ok(a == [1,2])
+
+a = loop do break *[]; end; test_ok(a == [])
+a = loop do break *[1]; end; test_ok(a == [1])
+a = loop do break *[nil]; end; test_ok(a == [nil])
+a = loop do break *[[]]; end; test_ok(a == [[]])
+a = loop do break *[*[]]; end; test_ok(a == [])
+a = loop do break *[*[1]]; end; test_ok(a == [1])
+a = loop do break *[*[1,2]]; end; test_ok(a == [1,2])
+
+*a = loop do break; end; test_ok(a == [nil])
+*a = loop do break nil; end; test_ok(a == [nil])
+*a = loop do break 1; end; test_ok(a == [1])
+*a = loop do break []; end; test_ok(a == [])
+*a = loop do break [1]; end; test_ok(a == [1])
+*a = loop do break [nil]; end; test_ok(a == [nil])
+*a = loop do break [[]]; end; test_ok(a == [[]])
+*a = loop do break [1,2]; end; test_ok(a == [1,2])
+*a = loop do break [*[]]; end; test_ok(a == [])
+*a = loop do break [*[1]]; end; test_ok(a == [1])
+*a = loop do break [*[1,2]]; end; test_ok(a == [1,2])
+
+*a = loop do break *[]; end; test_ok(a == [])
+*a = loop do break *[1]; end; test_ok(a == [1])
+*a = loop do break *[nil]; end; test_ok(a == [nil])
+*a = loop do break *[[]]; end; test_ok(a == [[]])
+*a = loop do break *[1,2]; end; test_ok(a == [1,2])
+*a = loop do break *[*[]]; end; test_ok(a == [])
+*a = loop do break *[*[1]]; end; test_ok(a == [1])
+*a = loop do break *[*[1,2]]; end; test_ok(a == [1,2])
+
+*a = *loop do break *[[]]; end; test_ok(a == [[]])
+*a = *loop do break *[1,2]; end; test_ok(a == [1,2])
+*a = *loop do break *[*[1,2]]; end; test_ok(a == [1,2])
+
+a,b,*c = loop do break; end; test_ok([a,b,c] == [nil,nil,[]])
+a,b,*c = loop do break nil; end; test_ok([a,b,c] == [nil,nil,[]])
+a,b,*c = loop do break 1; end; test_ok([a,b,c] == [1,nil,[]])
+a,b,*c = loop do break []; end; test_ok([a,b,c] == [nil,nil,[]])
+a,b,*c = loop do break [1]; end; test_ok([a,b,c] == [1,nil,[]])
+a,b,*c = loop do break [nil]; end; test_ok([a,b,c] == [nil,nil,[]])
+a,b,*c = loop do break [[]]; end; test_ok([a,b,c] == [[],nil,[]])
+a,b,*c = loop do break [1,2]; end; test_ok([a,b,c] == [1,2,[]])
+a,b,*c = loop do break [*[]]; end; test_ok([a,b,c] == [nil,nil,[]])
+a,b,*c = loop do break [*[1]]; end; test_ok([a,b,c] == [1,nil,[]])
+a,b,*c = loop do break [*[1,2]]; end; test_ok([a,b,c] == [1,2,[]])
+
+a,b,*c = loop do break *[]; end; test_ok([a,b,c] == [nil,nil,[]])
+a,b,*c = loop do break *[1]; end; test_ok([a,b,c] == [1,nil,[]])
+a,b,*c = loop do break *[nil]; end; test_ok([a,b,c] == [nil,nil,[]])
+a,b,*c = loop do break *[[]]; end; test_ok([a,b,c] == [[],nil,[]])
+a,b,*c = loop do break *[1,2]; end; test_ok([a,b,c] == [1,2,[]])
+a,b,*c = loop do break *[*[]]; end; test_ok([a,b,c] == [nil,nil,[]])
+a,b,*c = loop do break *[*[1]]; end; test_ok([a,b,c] == [1,nil,[]])
+a,b,*c = loop do break *[*[1,2]]; end; test_ok([a,b,c] == [1,2,[]])
+
+def r(val); a = yield(); test_ok(a == val, 2); end
+r(nil){next}
+r(nil){next nil}
+r(1){next 1}
+r([]){next []}
+r([1]){next [1]}
+r([nil]){next [nil]}
+r([[]]){next [[]]}
+r([]){next [*[]]}
+r([1]){next [*[1]]}
+r([1,2]){next [*[1,2]]}
+
+r([]){next *[]}
+r([1]){next *[1]}
+r([nil]){next *[nil]}
+r([[]]){next *[[]]}
+r([]){next *[*[]]}
+r([1]){next *[*[1]]}
+r([1,2]){next *[*[1,2]]}
+
+def r(val); *a = yield(); test_ok(a == val, 2); end
+r([nil]){next}
+r([nil]){next nil}
+r([1]){next 1}
+r([]){next []}
+r([1]){next [1]}
+r([nil]){next [nil]}
+r([[]]){next [[]]}
+r([1,2]){next [1,2]}
+r([]){next [*[]]}
+r([1]){next [*[1]]}
+r([1,2]){next [*[1,2]]}
+
+def r(val); *a = *yield(); test_ok(a == val, 2); end
+r([[]]){next *[[]]}
+r([1,2]){next *[1,2]}
+r([1,2]){next *[*[1,2]]}
+
+def r(val); a,b,*c = yield(); test_ok([a,b,c] == val, 2); end
+r([nil,nil,[]]){next}
+r([nil,nil,[]]){next nil}
+r([1,nil,[]]){next 1}
+r([nil,nil,[]]){next []}
+r([1,nil,[]]){next [1]}
+r([nil,nil,[]]){next [nil]}
+r([[],nil,[]]){next [[]]}
+r([1,2,[]]){next [1,2]}
+r([nil,nil,[]]){next [*[]]}
+r([1,nil,[]]){next [*[1]]}
+r([1,2,[]]){next [*[1,2]]}
+
+def r(val); a,b,*c = *yield(); test_ok([a,b,c] == val, 2); end
+r([[],nil,[]]){next *[[]]}
+r([1,2,[]]){next *[1,2]}
+r([1,2,[]]){next *[*[1,2]]}
+
+test_check "condition"
+
+$x = '0';
+
+$x == $x && test_ok(true)
+$x != $x && test_ok(false)
+$x == $x || test_ok(false)
+$x != $x || test_ok(true)
+
+# first test to see if we can run the tests.
+
+test_check "if/unless";
+
+$x = 'test';
+test_ok(if $x == $x then true else false end)
+$bad = false
+unless $x == $x
+  $bad = true
+end
+test_ok(!$bad)
+test_ok(unless $x != $x then true else false end)
+
+test_check "case"
+
+case 5
+when 1, 2, 3, 4, 6, 7, 8
+  test_ok(false)
+when 5
+  test_ok(true)
+end
+
+case 5
+when 5
+  test_ok(true)
+when 1..10
+  test_ok(false)
+end
+
+case 5
+when 1..10
+  test_ok(true)
+else
+  test_ok(false)
+end
+
+case 5
+when 5
+  test_ok(true)
+else
+  test_ok(false)
+end
+
+case "foobar"
+when /^f.*r$/
+  test_ok(true)
+else
+  test_ok(false)
+end
+
+test_check "while/until";
+
+while_tmp = "while_tmp.#{$$}"
+tmp = open(while_tmp, "w")
+tmp.print "tvi925\n";
+tmp.print "tvi920\n";
+tmp.print "vt100\n";
+tmp.print "Amiga\n";
+tmp.print "paper\n";
+tmp.close
+
+# test break
+
+tmp = open(while_tmp, "r")
+test_ok(tmp.kind_of?(File))
+
+while line = tmp.gets()
+  break if /vt100/ =~ line
+end
+
+test_ok(!tmp.eof? && /vt100/ =~ line)
+tmp.close
+
+# test next
+$bad = false
+tmp = open(while_tmp, "r")
+while line = tmp.gets()
+  next if /vt100/ =~ line
+  $bad = 1 if /vt100/ =~ line
+end
+test_ok(!(!tmp.eof? || /vt100/ =~ line || $bad))
+tmp.close
+
+# test redo
+$bad = false
+tmp = open(while_tmp, "r")
+while line = tmp.gets()
+  lastline = line
+  line = line.gsub(/vt100/, 'VT100')
+  if lastline != line
+    line.gsub!('VT100', 'Vt100')
+    redo
+  end
+  $bad = 1 if /vt100/ =~ line
+  $bad = 1 if /VT100/ =~ line
+end
+test_ok(tmp.eof? && !$bad)
+tmp.close
+
+sum=0
+for i in 1..10
+  sum += i
+  i -= 1
+  if i > 0
+    redo
+  end
+end
+test_ok(sum == 220)
+
+# test interval
+$bad = false
+tmp = open(while_tmp, "r")
+while line = tmp.gets()
+  break if 3
+  case line
+  when /vt100/, /Amiga/, /paper/
+    $bad = true
+  end
+end
+test_ok(!$bad)
+tmp.close
+
+File.unlink while_tmp or `/bin/rm -f "#{while_tmp}"`
+test_ok(!File.exist?(while_tmp))
+
+i = 0
+until i>4
+  i+=1
+end
+test_ok(i>4)
+
+
+# exception handling
+test_check "exception";
+
+begin
+  raise "this must be handled"
+  test_ok(false)
+rescue
+  test_ok(true)
+end
+
+$bad = true
+begin
+  raise "this must be handled no.2"
+rescue
+  if $bad
+    $bad = false
+    retry
+    test_ok(false)
+  end
+end
+test_ok(true)
+
+# exception in rescue clause
+$string = "this must be handled no.3"
+begin
+  begin
+    raise "exception in rescue clause"
+  rescue
+    raise $string
+  end
+  test_ok(false)
+rescue => e
+  test_ok($! == e)
+  test_ok(e.message == $string)
+  test_ok(e != $string)
+end
+
+# exception in ensure clause
+begin
+  begin
+    raise "this must be handled no.4"
+  ensure
+    raise "exception in ensure clause"
+  end
+  test_ok(false)
+rescue
+  test_ok(true)
+end
+
+$bad = true
+begin
+  begin
+    raise "this must be handled no.5"
+  ensure
+    $bad = false
+  end
+rescue
+end
+test_ok(!$bad)
+
+$bad = true
+begin
+  begin
+    raise "this must be handled no.6"
+  ensure
+    $bad = false
+  end
+rescue
+end
+test_ok(!$bad)
+
+$bad = true
+while true
+  begin
+    break
+  ensure
+    $bad = false
+  end
+end
+test_ok(!$bad)
+
+test_ok(catch(:foo) {
+     loop do
+       loop do
+	 throw :foo, true
+	 break
+       end
+       break
+       test_ok(false)			# should not reach here
+     end
+     false
+   })
+
+test_check "array"
+test_ok([1, 2] + [3, 4] == [1, 2, 3, 4])
+test_ok([1, 2] * 2 == [1, 2, 1, 2])
+test_ok([1, 2] * ":" == "1:2")
+
+test_ok([1, 2].hash == [1, 2].hash)
+
+test_ok([1,2,3] & [2,3,4] == [2,3])
+test_ok([1,2,3] | [2,3,4] == [1,2,3,4])
+test_ok([1,2,3] - [2,3] == [1])
+
+$x = [0, 1, 2, 3, 4, 5]
+test_ok($x[2] == 2)
+test_ok($x[1..3] == [1, 2, 3])
+test_ok($x[1,3] == [1, 2, 3])
+
+$x[0, 2] = 10
+test_ok($x[0] == 10 && $x[1] == 2)
+
+$x[0, 0] = -1
+test_ok($x[0] == -1 && $x[1] == 10)
+
+$x[-1, 1] = 20
+test_ok($x[-1] == 20 && $x.pop == 20)
+
+# array and/or
+test_ok(([1,2,3]&[2,4,6]) == [2])
+test_ok(([1,2,3]|[2,4,6]) == [1,2,3,4,6])
+
+# compact
+$x = [nil, 1, nil, nil, 5, nil, nil]
+$x.compact!
+test_ok($x == [1, 5])
+
+# uniq
+$x = [1, 1, 4, 2, 5, 4, 5, 1, 2]
+$x.uniq!
+test_ok($x == [1, 4, 2, 5])
+
+# empty?
+test_ok(!$x.empty?)
+$x = []
+test_ok($x.empty?)
+
+# sort
+$x = ["it", "came", "to", "pass", "that", "..."]
+$x = $x.sort.join(" ")
+test_ok($x == "... came it pass that to")
+$x = [2,5,3,1,7]
+$x.sort!{|a,b| a<=>b}		# sort with condition
+test_ok($x == [1,2,3,5,7])
+$x.sort!{|a,b| b-a}		# reverse sort
+test_ok($x == [7,5,3,2,1])
+
+# split test
+$x = "The Book of Mormon"
+test_ok($x.split(//).reverse!.join == $x.reverse)
+test_ok($x.reverse == $x.reverse!)
+test_ok("1 byte string".split(//).reverse.join(":") == "g:n:i:r:t:s: :e:t:y:b: :1")
+$x = "a b c  d"
+test_ok($x.split == ['a', 'b', 'c', 'd'])
+test_ok($x.split(' ') == ['a', 'b', 'c', 'd'])
+test_ok(defined? "a".chomp)
+test_ok("abc".scan(/./) == ["a", "b", "c"])
+test_ok("1a2b3c".scan(/(\d.)/) == [["1a"], ["2b"], ["3c"]])
+# non-greedy match
+test_ok("a=12;b=22".scan(/(.*?)=(\d*);?/) == [["a", "12"], ["b", "22"]])
+
+$x = [1]
+test_ok(($x * 5).join(":") == '1:1:1:1:1')
+test_ok(($x * 1).join(":") == '1')
+test_ok(($x * 0).join(":") == '')
+
+*$x = *(1..7).to_a
+test_ok($x.size == 7)
+test_ok($x == [1, 2, 3, 4, 5, 6, 7])
+
+$x = [1,2,3]
+$x[1,0] = $x
+test_ok($x == [1,1,2,3,2,3])
+
+$x = [1,2,3]
+$x[-1,0] = $x
+test_ok($x == [1,2,1,2,3,3])
+
+$x = [1,2,3]
+$x.concat($x)
+test_ok($x == [1,2,3,1,2,3])
+
+test_check "hash"
+$x = {1=>2, 2=>4, 3=>6}
+
+test_ok($x[1] == 2)
+
+test_ok(begin
+     for k,v in $x
+       raise if k*2 != v
+     end
+     true
+   rescue
+     false
+   end)
+
+test_ok($x.length == 3)
+test_ok($x.has_key?(1))
+test_ok($x.has_value?(4))
+test_ok($x.values_at(2,3) == [4,6])
+test_ok($x == {1=>2, 2=>4, 3=>6})
+
+$z = $x.keys.sort.join(":")
+test_ok($z == "1:2:3")
+
+$z = $x.values.sort.join(":")
+test_ok($z == "2:4:6")
+test_ok($x == $x)
+
+$x.shift
+test_ok($x.length == 2)
+
+$z = [1,2]
+$x[$z] = 256
+test_ok($x[$z] == 256)
+
+$x = Hash.new(0)
+$x[1] = 1
+test_ok($x[1] == 1)
+test_ok($x[2] == 0)
+
+$x = Hash.new([])
+test_ok($x[22] == [])
+test_ok($x[22].equal?($x[22]))
+
+$x = Hash.new{[]}
+test_ok($x[22] == [])
+test_ok(!$x[22].equal?($x[22]))
+
+$x = Hash.new{|h,k| $z = k; h[k] = k*2}
+$z = 0
+test_ok($x[22] == 44)
+test_ok($z == 22)
+$z = 0
+test_ok($x[22] == 44)
+test_ok($z == 0)
+$x.default = 5
+test_ok($x[23] == 5)
+
+$x = Hash.new
+def $x.default(k)
+  $z = k
+  self[k] = k*2
+end
+$z = 0
+test_ok($x[22] == 44)
+test_ok($z == 22)
+$z = 0
+test_ok($x[22] == 44)
+test_ok($z == 0)
+
+test_check "iterator"
+
+# yield at top level
+test_ok(!defined?(yield))
+
+$x = [1, 2, 3, 4]
+$y = []
+
+# iterator over array
+for i in $x
+  $y.push i
+end
+test_ok($x == $y)
+
+# nested iterator
+def tt
+  1.upto(10) {|i|
+    yield i
+  }
+end
+
+i=0
+tt{|i| break if i == 5}
+test_ok(i == 0)
+
+def tt2(dummy)
+  yield 1
+end
+
+def tt3(&block)
+  tt2(raise(ArgumentError,""),&block)
+end
+
+$x = false
+begin
+  tt3{}
+rescue ArgumentError
+  $x = true
+rescue Exception
+end
+test_ok($x)
+
+def tt4 &block
+  tt2(raise(ArgumentError,""),&block)
+end
+$x = false
+begin
+  tt4{}
+rescue ArgumentError
+  $x = true
+rescue Exception
+end
+test_ok($x)
+
+# iterator break/redo/next/retry
+done = true
+loop{
+  break
+  done = false			# should not reach here
+}
+test_ok(done)
+
+done = false
+$bad = false
+loop {
+  break if done
+  done = true
+  next
+  $bad = true			# should not reach here
+}
+test_ok(!$bad)
+
+done = false
+$bad = false
+loop {
+  break if done
+  done = true
+  redo
+  $bad = true			# should not reach here
+}
+test_ok(!$bad)
+
+$x = []
+for i in 1 .. 7
+  $x.push i
+end
+test_ok($x.size == 7)
+test_ok($x == [1, 2, 3, 4, 5, 6, 7])
+
+# append method to built-in class
+class Array
+  def iter_test1
+    collect{|e| [e, yield(e)]}.sort{|a,b|a[1]<=>b[1]}
+  end
+  def iter_test2
+    a = collect{|e| [e, yield(e)]}
+    a.sort{|a,b|a[1]<=>b[1]}
+  end
+end
+$x = [[1,2],[3,4],[5,6]]
+test_ok($x.iter_test1{|x|x} == $x.iter_test2{|x|x})
+
+class IterTest
+  def initialize(e); @body = e; end
+
+  def each0(&block); @body.each(&block); end
+  def each1(&block); @body.each {|*x| block.call(*x) } end
+  def each2(&block); @body.each {|*x| block.call(x) } end
+  def each3(&block); @body.each {|x| block.call(*x) } end
+  def each4(&block); @body.each {|x| block.call(x) } end
+  def each5; @body.each {|*x| yield(*x) } end
+  def each6; @body.each {|*x| yield(x) } end
+  def each7; @body.each {|x| yield(*x) } end
+  def each8; @body.each {|x| yield(x) } end
+
+  def f(a)
+    a
+  end
+end
+test_ok(IterTest.new(nil).method(:f).to_proc.call([1]) == [1])
+m = /\w+/.match("abc")
+test_ok(IterTest.new(nil).method(:f).to_proc.call([m]) == [m])
+
+IterTest.new([0]).each0 {|x| test_ok(x == 0)}
+IterTest.new([1]).each1 {|x| test_ok(x == 1)}
+IterTest.new([2]).each2 {|x| test_ok(x == [2])}
+#IterTest.new([3]).each3 {|x| test_ok(x == 3)}
+IterTest.new([4]).each4 {|x| test_ok(x == 4)}
+IterTest.new([5]).each5 {|x| test_ok(x == 5)}
+IterTest.new([6]).each6 {|x| test_ok(x == [6])}
+#IterTest.new([7]).each7 {|x| test_ok(x == 7)}
+IterTest.new([8]).each8 {|x| test_ok(x == 8)}
+
+IterTest.new([[0]]).each0 {|x| test_ok(x == [0])}
+IterTest.new([[1]]).each1 {|x| test_ok(x == [1])}
+IterTest.new([[2]]).each2 {|x| test_ok(x == [[2]])}
+IterTest.new([[3]]).each3 {|x| test_ok(x == 3)}
+IterTest.new([[4]]).each4 {|x| test_ok(x == [4])}
+IterTest.new([[5]]).each5 {|x| test_ok(x == [5])}
+IterTest.new([[6]]).each6 {|x| test_ok(x == [[6]])}
+IterTest.new([[7]]).each7 {|x| test_ok(x == 7)}
+IterTest.new([[8]]).each8 {|x| test_ok(x == [8])}
+
+IterTest.new([[0,0]]).each0 {|*x| test_ok(x == [[0,0]])}
+IterTest.new([[8,8]]).each8 {|*x| test_ok(x == [[8,8]])}
+
+def m0(v)
+  v
+end
+
+def m1
+  m0(block_given?)
+end
+test_ok(m1{p 'test'})
+test_ok(!m1)
+
+def m
+  m0(block_given?,&Proc.new{})
+end
+test_ok(m1{p 'test'})
+test_ok(!m1)
+
+class C
+  include Enumerable
+  def initialize
+    @a = [1,2,3]
+  end
+  def each(&block)
+    @a.each(&block)
+  end
+end
+
+test_ok(C.new.collect{|n| n} == [1,2,3])
+
+test_ok(Proc == lambda{}.class)
+test_ok(Proc == Proc.new{}.class)
+lambda{|a|test_ok(a==1)}.call(1)
+def block_test(klass, &block)
+  test_ok(klass === block)
+end
+
+block_test(NilClass)
+block_test(Proc){}
+
+def call_argument_test(state, proc, *args)
+  x = state
+  begin
+    proc.call(*args)
+  rescue ArgumentError
+    x = !x
+  end
+  test_ok(x,2)
+end
+
+call_argument_test(true, lambda{||})
+call_argument_test(false, lambda{||}, 1)
+call_argument_test(true, lambda{|a,|}, 1)
+call_argument_test(false, lambda{|a,|})
+call_argument_test(false, lambda{|a,|}, 1,2)
+
+call_argument_test(true, Proc.new{||})
+call_argument_test(true, Proc.new{||}, 1)
+call_argument_test(true, Proc.new{|a,|}, 1)
+call_argument_test(true, Proc.new{|a,|})
+call_argument_test(true, Proc.new{|a,|}, 1,2)
+
+def block_get(&block)
+  block
+end
+
+test_ok(Proc == block_get{}.class)
+call_argument_test(true, block_get{||})
+call_argument_test(true, block_get{||}, 1)
+call_argument_test(true, block_get{|a,|}, 1)
+call_argument_test(true, block_get{|a,|})
+call_argument_test(true, block_get{|a,|}, 1,2)
+
+call_argument_test(true, block_get(&lambda{||}))
+call_argument_test(false, block_get(&lambda{||}),1)
+call_argument_test(true, block_get(&lambda{|a,|}),1)
+call_argument_test(false, block_get(&lambda{|a,|}),1,2)
+
+blk = block_get{11}
+test_ok(blk.class == Proc)
+test_ok(blk.to_proc.class == Proc)
+test_ok(blk.clone.call == 11)
+test_ok(block_get(&blk).class == Proc)
+
+lmd = lambda{44}
+test_ok(lmd.class == Proc)
+test_ok(lmd.to_proc.class == Proc)
+test_ok(lmd.clone.call == 44)
+test_ok(block_get(&lmd).class == Proc)
+
+test_ok(Proc.new{|a,| a}.yield(1,2,3) == 1)
+call_argument_test(true, Proc.new{|a,|}, 1,2)
+
+test_ok(Proc.new{|&b| b.call(10)}.call {|x| x} == 10)
+test_ok(Proc.new{|a,&b| b.call(a)}.call(12) {|x| x} == 12)
+
+def test_return1
+  Proc.new {
+    return 55
+  }.yield + 5
+end
+test_ok(test_return1() == 55)
+def test_return2
+  lambda {
+    return 55
+  }.call + 5
+end
+test_ok(test_return2() == 60)
+
+def proc_call(&b)
+  b.call
+end
+def proc_yield()
+  yield
+end
+def proc_return1
+  lambda{return 42}.call+1
+end
+test_ok(proc_return1() == 43)
+def proc_return2
+  ->{return 42}.call+1
+end
+test_ok(proc_return2() == 43)
+def proc_return3
+  proc_call{return 42}+1
+end
+test_ok(proc_return3() == 42)
+def proc_return4
+  proc_yield{return 42}+1
+end
+test_ok(proc_return4() == 42)
+
+def ljump_test(state, proc, *args)
+  x = state
+  begin
+    proc.call(*args)
+  rescue LocalJumpError
+    x = !x
+  end
+  test_ok(x,2)
+end
+
+ljump_test(false, block_get{break})
+ljump_test(true, lambda{break})
+
+def exit_value_test(&block)
+  block.call
+rescue LocalJumpError
+  $!.exit_value
+end
+
+test_ok(45 == exit_value_test{break 45})
+
+test_ok(55 == begin
+              block_get{break 55}.call
+            rescue LocalJumpError
+              $!.exit_value
+            end)
+
+def block_call(&block)
+  block.call
+end
+
+def test_b1
+  block_call{break 11}
+end
+test_ok(test_b1() == 11)
+
+def ljump_rescue(r)
+  begin
+    yield
+  rescue LocalJumpError => e
+    r if /from proc-closure/ =~ e.message
+  end
+end
+
+def test_b2
+  ljump_rescue(22) do
+    block_get{break 21}.call
+  end
+end
+test_ok(test_b2() == 22)
+
+def test_b3
+  ljump_rescue(33) do
+    Proc.new{break 31}.yield
+  end
+end
+test_ok(test_b3() == 33)
+
+def test_b4
+  lambda{break 44}.call
+end
+test_ok(test_b4() == 44)
+
+def test_b5
+  ljump_rescue(55) do
+    b = block_get{break 54}
+    block_call(&b)
+  end
+end
+test_ok(test_b5() == 55)
+
+def test_b6
+  b = lambda{break 67}
+  block_call(&b)
+  66
+end
+test_ok(test_b6() == 66)
+
+def util_r7
+  block_get{break 78}
+end
+
+def test_b7
+  b = util_r7()
+  ljump_rescue(77) do
+    block_call(&b)
+  end
+end
+test_ok(test_b7() == 77)
+
+def util_b8(&block)
+  block_call(&block)
+end
+
+def test_b8
+  util_b8{break 88}
+end
+test_ok(test_b8() == 88)
+
+def util_b9(&block)
+  lambda{block.call; 98}.call
+end
+
+def test_b9
+  util_b9{break 99}
+end
+test_ok(test_b9() == 99)
+
+def util_b10
+  util_b9{break 100}
+end
+
+def test_b10
+  util_b10()
+end
+test_ok(test_b10() == 100)
+
+def test_b11
+  ljump_rescue(111) do
+    loop do
+      Proc.new{break 110}.yield
+      break 112
+    end
+  end
+end
+test_ok(test_b11() == 111)
+
+def test_b12
+  loop do
+    break lambda{break 122}.call
+    break 121
+  end
+end
+test_ok(test_b12() == 122)
+
+def test_b13
+  ljump_rescue(133) do
+    while true
+      Proc.new{break 130}.yield
+      break 131
+    end
+  end
+end
+test_ok(test_b13() == 133)
+
+def test_b14
+  while true
+    break lambda{break 144}.call
+    break 143
+  end
+end
+test_ok(test_b14() == 144)
+
+def test_b15
+  [0].each {|c| yield 1 }
+  156
+end
+test_ok(test_b15{|e| break 155 } == 155)
+
+def marity_test(m)
+  method = method(m)
+  test_ok(method.arity == method.to_proc.arity, 2)
+end
+marity_test(:test_ok)
+marity_test(:marity_test)
+marity_test(:p)
+
+class ITER_TEST1
+   def a
+     block_given?
+   end
+end
+
+class ITER_TEST2 < ITER_TEST1
+   def a
+     test_ok(super)
+     super
+   end
+end
+test_ok(ITER_TEST2.new.a {})
+
+class ITER_TEST3
+  def foo x
+    return yield if block_given?
+    x
+  end
+end
+
+class ITER_TEST4 < ITER_TEST3
+  def foo x
+    test_ok(super == yield)
+    test_ok(super(x, &nil) == x)
+  end
+end
+
+ITER_TEST4.new.foo(44){55}
+
+class ITER_TEST5
+   def tt(aa)
+     aa
+   end
+
+   def uu(a)
+      class << self
+         define_method(:tt) do |sym|
+            super(sym)
+         end
+      end
+   end
+
+   def xx(*x)
+     x.size
+   end
+end
+
+a = ITER_TEST5.new
+a.uu(12)
+test_ok(a.tt(1) == 1)
+
+class ITER_TEST6 < ITER_TEST5
+   def xx(*a)
+      a << 12
+      super
+   end
+end
+
+test_ok(ITER_TEST6.new.xx([24]) == 2)
+
+test_check "float"
+test_ok(2.6.floor == 2)
+test_ok((-2.6).floor == -3)
+test_ok(2.6.ceil == 3)
+test_ok((-2.6).ceil == -2)
+test_ok(2.6.truncate == 2)
+test_ok((-2.6).truncate == -2)
+test_ok(2.6.round == 3)
+test_ok((-2.4).truncate == -2)
+test_ok((13.4 % 1 - 0.4).abs < 0.0001)
+nan = 0.0/0
+def nan_test(x,y)
+  test_ok(x != y)
+  test_ok((x < y) == false)
+  test_ok((x > y) == false)
+  test_ok((x <= y) == false)
+  test_ok((x >= y) == false)
+end
+nan_test(nan, nan)
+nan_test(nan, 0)
+nan_test(nan, 1)
+nan_test(nan, -1)
+nan_test(nan, 1000)
+nan_test(nan, -1000)
+nan_test(nan, 1_000_000_000_000)
+nan_test(nan, -1_000_000_000_000)
+nan_test(nan, 100.0);
+nan_test(nan, -100.0);
+nan_test(nan, 0.001);
+nan_test(nan, -0.001);
+nan_test(nan, 1.0/0);
+nan_test(nan, -1.0/0);
+
+#s = "3.7517675036461267e+17"
+#test_ok(s == sprintf("%.16e", s.to_f))
+f = 3.7517675036461267e+17
+test_ok(f == sprintf("%.16e", f).to_f)
+
+
+test_check "bignum"
+def fact(n)
+  return 1 if n == 0
+  f = 1
+  while n>0
+    f *= n
+    n -= 1
+  end
+  return f
+end
+$x = fact(40)
+test_ok($x == $x)
+test_ok($x == fact(40))
+test_ok($x < $x+2)
+test_ok($x > $x-2)
+test_ok($x == 815915283247897734345611269596115894272000000000)
+test_ok($x != 815915283247897734345611269596115894272000000001)
+test_ok($x+1 == 815915283247897734345611269596115894272000000001)
+test_ok($x/fact(20) == 335367096786357081410764800000)
+$x = -$x
+test_ok($x == -815915283247897734345611269596115894272000000000)
+test_ok(2-(2**32) == -(2**32-2))
+test_ok(2**32 - 5 == (2**32-3)-2)
+
+$good = true;
+for i in 1000..1014
+  $good = false if ((1 << i) != (2**i))
+end
+test_ok($good)
+
+$good = true;
+n1= 1 << 1000
+for i in 1000..1014
+  $good = false if ((1 << i) != n1)
+  n1 *= 2
+end
+test_ok($good)
+
+$good = true;
+n2=n1
+for i in 1..10
+  n1 = n1 / 2
+  n2 = n2 >> 1
+  $good = false if (n1 != n2)
+end
+test_ok($good)
+
+$good = true;
+for i in 4000..4096
+  n1 = 1 << i;
+  if (n1**2-1) / (n1+1) != (n1-1)
+    $good = false
+  end
+end
+test_ok($good)
+
+b = 10**80
+a = b * 9 + 7
+test_ok(7 == a.modulo(b))
+test_ok(-b + 7 == a.modulo(-b))
+test_ok(b + -7 == (-a).modulo(b))
+test_ok(-7 == (-a).modulo(-b))
+test_ok(7 == a.remainder(b))
+test_ok(7 == a.remainder(-b))
+test_ok(-7 == (-a).remainder(b))
+test_ok(-7 == (-a).remainder(-b))
+
+test_ok(10**40+10**20 == 10000000000000000000100000000000000000000)
+test_ok(10**40/10**20 == 100000000000000000000)
+
+a = 677330545177305025495135714080
+b = 14269972710765292560
+test_ok(a % b == 0)
+test_ok(-a % b == 0)
+
+def shift_test(a)
+  b = a / (2 ** 32)
+  c = a >> 32
+  test_ok(b == c)
+
+  b = a * (2 ** 32)
+  c = a << 32
+  test_ok(b == c)
+end
+
+shift_test(-4518325415524767873)
+shift_test(-0xfffffffffffffffff)
+
+test_check "string & char"
+
+test_ok("abcd" == "abcd")
+test_ok("abcd" =~ /abcd/)
+test_ok("abcd" === "abcd")
+# compile time string concatenation
+test_ok("ab" "cd" == "abcd")
+test_ok("#{22}aa" "cd#{44}" == "22aacd44")
+test_ok("#{22}aa" "cd#{44}" "55" "#{66}" == "22aacd445566")
+test_ok("abc" !~ /^$/)
+test_ok("abc\n" !~ /^$/)
+test_ok("abc" !~ /^d*$/)
+test_ok(("abc" =~ /d*$/) == 3)
+test_ok("" =~ /^$/)
+test_ok("\n" =~ /^$/)
+test_ok("a\n\n" =~ /^$/)
+test_ok("abcabc" =~ /.*a/ && $& == "abca")
+test_ok("abcabc" =~ /.*c/ && $& == "abcabc")
+test_ok("abcabc" =~ /.*?a/ && $& == "a")
+test_ok("abcabc" =~ /.*?c/ && $& == "abc")
+test_ok(/(.|\n)*?\n(b|\n)/ =~ "a\nb\n\n" && $& == "a\nb")
+
+test_ok(/^(ab+)+b/ =~ "ababb" && $& == "ababb")
+test_ok(/^(?:ab+)+b/ =~ "ababb" && $& == "ababb")
+test_ok(/^(ab+)+/ =~ "ababb" && $& == "ababb")
+test_ok(/^(?:ab+)+/ =~ "ababb" && $& == "ababb")
+
+test_ok(/(\s+\d+){2}/ =~ " 1 2" && $& == " 1 2")
+test_ok(/(?:\s+\d+){2}/ =~ " 1 2" && $& == " 1 2")
+
+$x = <<END;
+ABCD
+ABCD
+END
+$x.gsub!(/((.|\n)*?)B((.|\n)*?)D/, '\1\3')
+test_ok($x == "AC\nAC\n")
+
+test_ok("foobar" =~ /foo(?=(bar)|(baz))/)
+test_ok("foobaz" =~ /foo(?=(bar)|(baz))/)
+
+$foo = "abc"
+test_ok("#$foo = abc" == "abc = abc")
+test_ok("#{$foo} = abc" == "abc = abc")
+
+foo = "abc"
+test_ok("#{foo} = abc" == "abc = abc")
+
+test_ok('-' * 5 == '-----')
+test_ok('-' * 1 == '-')
+test_ok('-' * 0 == '')
+
+foo = '-'
+test_ok(foo * 5 == '-----')
+test_ok(foo * 1 == '-')
+test_ok(foo * 0 == '')
+
+$x = "a.gif"
+test_ok($x.sub(/.*\.([^\.]+)$/, '\1') == "gif")
+test_ok($x.sub(/.*\.([^\.]+)$/, 'b.\1') == "b.gif")
+test_ok($x.sub(/.*\.([^\.]+)$/, '\2') == "")
+test_ok($x.sub(/.*\.([^\.]+)$/, 'a\2b') == "ab")
+test_ok($x.sub(/.*\.([^\.]+)$/, '<\&>') == "<a.gif>")
+
+# character constants(assumes ASCII)
+test_ok("a"[0] == ?a)
+test_ok(?a == ?a)
+test_ok(?\C-a == "\1")
+test_ok(?\M-a == "\341")
+test_ok(?\M-\C-a == "\201")
+test_ok("a".upcase![0] == ?A)
+test_ok("A".downcase![0] == ?a)
+test_ok("abc".tr!("a-z", "A-Z") == "ABC")
+test_ok("aabbcccc".tr_s!("a-z", "A-Z") == "ABC")
+test_ok("abcc".squeeze!("a-z") == "abc")
+test_ok("abcd".delete!("bc") == "ad")
+
+$x = "abcdef"
+$y = [ ?a, ?b, ?c, ?d, ?e, ?f ]
+$bad = false
+$x.each_byte {|i|
+  if i.chr != $y.shift
+    $bad = true
+    break
+  end
+}
+test_ok(!$bad)
+
+s = "a string"
+s[0..s.size]="another string"
+test_ok(s == "another string")
+
+s = <<EOS
+#{
+[1,2,3].join(",")
+}
+EOS
+test_ok(s == "1,2,3\n")
+test_ok("Just".to_i(36) == 926381)
+test_ok("-another".to_i(36) == -23200231779)
+test_ok(1299022.to_s(36) == "ruby")
+test_ok(-1045307475.to_s(36) == "-hacker")
+test_ok("Just_another_Ruby_hacker".to_i(36) == 265419172580680477752431643787347)
+test_ok(-265419172580680477752431643787347.to_s(36) == "-justanotherrubyhacker")
+
+a = []
+(0..255).each {|n|
+  ch = [n].pack("C")
+  a.push ch if /a#{Regexp.quote ch}b/x =~ "ab"
+}
+test_ok(a.size == 0)
+
+test_check "assignment"
+a = nil
+test_ok(defined?(a))
+test_ok(a == nil)
+
+# multiple assignment
+a, b = 1, 2
+test_ok(a == 1 && b == 2)
+
+a, b = b, a
+test_ok(a == 2 && b == 1)
+
+a, = 1,2
+test_ok(a == 1)
+
+a, *b = 1, 2, 3
+test_ok(a == 1 && b == [2, 3])
+
+a, (b, c), d = 1, [2, 3], 4
+test_ok(a == 1 && b == 2 && c == 3 && d == 4)
+
+*a = 1, 2, 3
+test_ok(a == [1, 2, 3])
+
+*a = 4
+test_ok(a == [4])
+
+*a = nil
+test_ok(a == [nil])
+
+test_check "call"
+def aaa(a, b=100, *rest)
+  res = [a, b]
+  res += rest if rest
+  return res
+end
+
+# not enough argument
+begin
+  aaa()				# need at least 1 arg
+  test_ok(false)
+rescue
+  test_ok(true)
+end
+
+begin
+  aaa				# no arg given (exception raised)
+  test_ok(false)
+rescue
+  test_ok(true)
+end
+
+test_ok(aaa(1) == [1, 100])
+test_ok(aaa(1, 2) == [1, 2])
+test_ok(aaa(1, 2, 3, 4) == [1, 2, 3, 4])
+test_ok(aaa(1, *[2, 3, 4]) == [1, 2, 3, 4])
+
+test_check "proc"
+$proc = Proc.new{|i| i}
+test_ok($proc.call(2) == 2)
+test_ok($proc.call(3) == 3)
+
+$proc = Proc.new{|i| i*2}
+test_ok($proc.call(2) == 4)
+test_ok($proc.call(3) == 6)
+
+Proc.new{
+  iii=5				# nested local variable
+  $proc = Proc.new{|i|
+    iii = i
+  }
+  $proc2 = Proc.new {
+    $x = iii			# nested variables shared by procs
+  }
+  # scope of nested variables
+  test_ok(defined?(iii))
+}.call
+test_ok(!defined?(iii))		# out of scope
+
+loop{iii=5; test_ok(eval("defined? iii")); break}
+loop {
+  iii = 10
+  def dyna_var_check
+    loop {
+      test_ok(!defined?(iii))
+      break
+    }
+  end
+  dyna_var_check
+  break
+}
+$x=0
+$proc.call(5)
+$proc2.call
+test_ok($x == 5)
+
+if defined? Process.kill
+  test_check "signal"
+
+  $x = 0
+  trap "SIGINT", Proc.new{|sig| $x = 2}
+  Process.kill "SIGINT", $$
+  100.times {
+    sleep 0.1
+    break if $x != 0
+  }
+  test_ok($x == 2)
+
+  trap "SIGINT", Proc.new{raise "Interrupt"}
+
+  x = false
+  begin
+    Process.kill "SIGINT", $$
+    sleep 0.1
+  rescue
+    x = $!
+  end
+  test_ok(x && /Interrupt/ =~ x.message)
+end
+
+test_check "eval"
+test_ok(eval("") == nil)
+$bad=false
+eval 'while false; $bad = true; print "foo\n" end'
+test_ok(!$bad)
+
+test_ok(eval('Object'))
+test_ok(eval('true'))
+test_ok(!eval('nil'))
+test_ok(!eval('false'))
+
+$foo = 'test_ok(true)'
+begin
+  eval $foo
+rescue
+  test_ok(false)
+end
+
+test_ok(eval("$foo") == 'test_ok(true)')
+test_ok(eval("true") == true)
+i = 5
+test_ok(eval("i == 5"))
+test_ok(eval("i") == 5)
+test_ok(eval("defined? i"))
+
+# eval with binding
+def test_ev
+  local1 = "local1"
+  lambda {
+    local2 = "local2"
+    return binding
+  }.call
+end
+
+$x = test_ev
+test_ok(eval("local1", $x) == "local1") # normal local var
+test_ok(eval("local2", $x) == "local2") # nested local var
+$bad = true
+begin
+  p eval("local1")
+rescue NameError		# must raise error
+  $bad = false
+end
+test_ok(!$bad)
+
+module EvTest
+  EVTEST1 = 25
+  evtest2 = 125
+  $x = binding
+end
+test_ok(eval("EVTEST1", $x) == 25)	# constant in module
+test_ok(eval("evtest2", $x) == 125)	# local var in module
+$bad = true
+begin
+  eval("EVTEST1")
+rescue NameError		# must raise error
+  $bad = false
+end
+test_ok(!$bad)
+
+x = binding #! YARV Limitation: Proc.new{}
+eval "i4 = 1", x
+test_ok(eval("i4", x) == 1)
+x = Proc.new{binding}.call #! YARV Limitation: Proc.new{Proc.new{}}.call
+eval "i4 = 22", x
+test_ok(eval("i4", x) == 22)
+$x = []
+x = Proc.new{binding}.call #! YARV Limitation: Proc.new{Proc.new{}}.call
+eval "(0..9).each{|i5| $x[i5] = Proc.new{i5*2}}", x
+test_ok($x[4].call == 8)
+
+x = binding
+eval "i = 1", x
+test_ok(eval("i", x) == 1)
+x = Proc.new{binding}.call
+eval "i = 22", x
+test_ok(eval("i", x) == 22)
+$x = []
+x = Proc.new{binding}.call
+eval "(0..9).each{|i5| $x[i5] = Proc.new{i5*2}}", x
+test_ok($x[4].call == 8)
+x = Proc.new{binding}.call
+eval "for i6 in 1..1; j6=i6; end", x
+test_ok(eval("defined? i6", x))
+test_ok(eval("defined? j6", x))
+
+Proc.new {
+  p = binding
+  eval "foo11 = 1", p
+  foo22 = 5
+  Proc.new{foo11=22}.call
+  Proc.new{foo22=55}.call
+  test_ok(eval("foo11", p) == eval("foo11"))
+  test_ok(eval("foo11") == 1)
+  test_ok(eval("foo22", p) == eval("foo22"))
+  test_ok(eval("foo22") == 55)
+}.call if false #! YARV Limitation
+
+#! YARV Limitation: p1 = Proc.new{i7 = 0; Proc.new{i7}}.call
+p1 = Proc.new{i7 = 0; binding}.call
+#! YARV Limitation: test_ok(p1.call == 0)
+eval "i7=5", p1
+#! YARV Limitation: test_ok(p1.call == 5)
+test_ok(!defined?(i7))
+
+if false #! YARV Limitation
+p1 = Proc.new{i7 = 0; Proc.new{i7}}.call
+i7 = nil
+test_ok(p1.call == 0)
+eval "i7=1", p1
+test_ok(p1.call == 1)
+eval "i7=5", p1
+test_ok(p1.call == 5)
+test_ok(i7 == nil)
+end
+
+test_check "system"
+test_ok(`echo foobar` == "foobar\n")
+test_ok(`./miniruby -e 'print "foobar"'` == 'foobar')
+
+script_tmp = "script_tmp.#{$$}"
+tmp = open(script_tmp, "w")
+tmp.print "print $zzz\n";
+tmp.close
+
+test_ok(`./miniruby -s #{script_tmp} -zzz` == 'true')
+test_ok(`./miniruby -s #{script_tmp} -zzz=555` == '555')
+
+tmp = open(script_tmp, "w")
+tmp.print "#! /usr/local/bin/ruby -s\n";
+tmp.print "print $zzz\n";
+tmp.close
+
+test_ok(`./miniruby #{script_tmp} -zzz=678` == '678')
+
+tmp = open(script_tmp, "w")
+tmp.print "this is a leading junk\n";
+tmp.print "#! /usr/local/bin/ruby -s\n";
+tmp.print "print $zzz\n";
+tmp.print "__END__\n";
+tmp.print "this is a trailing junk\n";
+tmp.close
+
+test_ok(`./miniruby -x #{script_tmp}` == '')
+test_ok(`./miniruby -x #{script_tmp} -zzz=555` == '555')
+
+tmp = open(script_tmp, "w")
+for i in 1..5
+  tmp.print i, "\n"
+end
+tmp.close
+
+`./miniruby -i.bak -pe '$_.sub!(/^[0-9]+$/){$&.to_i * 5}' #{script_tmp}`
+done = true
+tmp = open(script_tmp, "r")
+while tmp.gets
+  if $_.to_i % 5 != 0
+    done = false
+    break
+  end
+end
+tmp.close
+test_ok(done)
+
+File.unlink script_tmp or `/bin/rm -f "#{script_tmp}"`
+File.unlink "#{script_tmp}.bak" or `/bin/rm -f "#{script_tmp}.bak"`
+
+test_check "const"
+TEST1 = 1
+TEST2 = 2
+
+module Const
+  TEST3 = 3
+  TEST4 = 4
+end
+
+module Const2
+  TEST3 = 6
+  TEST4 = 8
+end
+
+include Const
+
+test_ok([TEST1,TEST2,TEST3,TEST4] == [1,2,3,4])
+
+include Const2
+STDERR.print "intentionally redefines TEST3, TEST4\n" if $VERBOSE
+test_ok([TEST1,TEST2,TEST3,TEST4] == [1,2,6,8])
+
+
+test_ok((String <=> Object) == -1)
+test_ok((Object <=> String) == 1)
+test_ok((Array <=> String) == nil)
+
+test_check "clone"
+foo = Object.new
+def foo.test
+  "test"
+end
+bar = foo.clone
+def bar.test2
+  "test2"
+end
+
+test_ok(bar.test2 == "test2")
+test_ok(bar.test == "test")
+test_ok(foo.test == "test")
+
+begin
+  foo.test2
+  test_ok false
+rescue NoMethodError
+  test_ok true
+end
+
+module M001; end
+module M002; end
+module M003; include M002; end
+module M002; include M001; end
+module M003; include M002; end
+
+test_ok(M003.ancestors == [M003, M002, M001])
+
+test_check "marshal"
+$x = [1,2,3,[4,5,"foo"],{1=>"bar"},2.5,fact(30)]
+$y = Marshal.dump($x)
+test_ok($x == Marshal.load($y))
+
+StrClone=String.clone;
+test_ok(Marshal.load(Marshal.dump(StrClone.new("abc"))).class == StrClone)
+
+[[1,2,3,4], [81, 2, 118, 3146]].each { |w,x,y,z|
+  a = (x.to_f + y.to_f / z.to_f) * Math.exp(w.to_f / (x.to_f + y.to_f / z.to_f))
+  ma = Marshal.dump(a)
+  b = Marshal.load(ma)
+  test_ok(a == b)
+}
+
+test_check "pack"
+
+$format = "c2x5CCxsdils_l_a6";
+# Need the expression in here to force ary[5] to be numeric.  This avoids
+# test2 failing because ary2 goes str->numeric->str and ary does not.
+ary = [1,-100,127,128,32767,987.654321098 / 100.0,12345,123456,-32767,-123456,"abcdef"]
+$x = ary.pack($format)
+ary2 = $x.unpack($format)
+
+test_ok(ary.length == ary2.length)
+test_ok(ary.join(':') == ary2.join(':'))
+test_ok($x =~ /def/)
+
+$x = [-1073741825]
+test_ok($x.pack("q").unpack("q") == $x)
+
+test_check "math"
+test_ok(Math.sqrt(4) == 2)
+
+include Math
+test_ok(sqrt(4) == 2)
+
+test_check "struct"
+struct_test = Struct.new("Test", :foo, :bar)
+test_ok(struct_test == Struct::Test)
+
+test = struct_test.new(1, 2)
+test_ok(test.foo == 1 && test.bar == 2)
+test_ok(test[0] == 1 && test[1] == 2)
+
+a, b = test.to_a
+test_ok(a == 1 && b == 2)
+
+test[0] = 22
+test_ok(test.foo == 22)
+
+test.bar = 47
+test_ok(test.bar == 47)
+
+test_check "variable"
+test_ok($$.instance_of?(Integer))
+
+# read-only variable
+begin
+  $$ = 5
+  test_ok false
+rescue NameError
+  test_ok true
+end
+
+foobar = "foobar"
+$_ = foobar
+test_ok($_ == foobar)
+
+class Gods
+  @@rule = "Uranus"
+  def ruler0
+    @@rule
+  end
+
+  def self.ruler1		# <= per method definition style
+    @@rule
+  end
+  class << self			# <= multiple method definition style
+    def ruler2
+      @@rule
+    end
+  end
+end
+
+module Olympians
+  @@rule ="Zeus"
+  def ruler3
+    @@rule
+  end
+end
+
+class Titans < Gods
+  @@rule = "Cronus"		# modifies @@rule in Gods
+  include Olympians
+  def ruler4
+    @@rule
+  end
+end
+
+test_ok(Gods.new.ruler0 == "Cronus")
+test_ok(Gods.ruler1 == "Cronus")
+test_ok(Gods.ruler2 == "Cronus")
+test_ok(Titans.ruler1 == "Cronus")
+test_ok(Titans.ruler2 == "Cronus")
+atlas = Titans.new
+test_ok(atlas.ruler0 == "Cronus")
+test_ok(atlas.ruler3 == "Zeus")
+begin
+  atlas.ruler4
+rescue RuntimeError => e
+  test_ok(e.message.include?("class variable @@rule of Olympians is overtaken by Gods"))
+else
+  test_ok(false)
+end
+test_ok(atlas.ruler3 == "Zeus")
+
+test_check "trace"
+$x = 1234
+$y = 0
+trace_var :$x, Proc.new{$y = $x}
+$x = 40414
+test_ok($y == $x)
+
+untrace_var :$x
+$x = 19660208
+test_ok($y != $x)
+
+trace_var :$x, Proc.new{$x *= 2}
+$x = 5
+test_ok($x == 10)
+
+untrace_var :$x
+
+test_check "defined?"
+
+test_ok(defined?($x))		# global variable
+test_ok(defined?($x) == 'global-variable')# returns description
+
+foo=5
+test_ok(defined?(foo))		# local variable
+
+test_ok(defined?(Array))	# constant
+test_ok(defined?(Object.new))	# method
+test_ok(!defined?(Object.print))# private method
+test_ok(defined?(1 == 2))	# operator expression
+
+class Foo
+  def foo
+    p :foo
+  end
+  protected :foo
+  def bar(f)
+    test_ok(defined?(self.foo))
+    test_ok(defined?(f.foo))
+  end
+end
+f = Foo.new
+test_ok(defined?(f.foo) == nil)
+f.bar(f)
+
+def defined_test
+  return !defined?(yield)
+end
+
+test_ok(defined_test)		# not iterator
+test_ok(!defined_test{})	# called as iterator
+
+test_check "alias"
+class Alias0
+  def foo; "foo" end
+end
+class Alias1 < Alias0
+  alias bar foo
+  def foo; "foo+" + super end
+end
+class Alias2 < Alias1
+  alias baz foo
+  undef foo
+end
+
+x = Alias2.new
+test_ok(x.bar == "foo")
+test_ok(x.baz == "foo+foo")
+
+# test_check for cache
+test_ok(x.baz == "foo+foo")
+
+class Alias3 < Alias2
+  def foo
+    defined? super
+  end
+  def bar
+    defined? super
+  end
+  def quux
+    defined? super
+  end
+end
+x = Alias3.new
+test_ok(!x.foo)
+test_ok(x.bar)
+test_ok(!x.quux)
+
+test_check "path"
+test_ok(File.basename("a") == "a")
+test_ok(File.basename("a/b") == "b")
+test_ok(File.basename("a/b/") == "b")
+test_ok(File.basename("/") == "/")
+test_ok(File.basename("//") == "/")
+test_ok(File.basename("///") == "/")
+test_ok(File.basename("a/b////") == "b")
+test_ok(File.basename("a.rb", ".rb") == "a")
+test_ok(File.basename("a.rb///", ".rb") == "a")
+test_ok(File.basename("a.rb///", ".*") == "a")
+test_ok(File.basename("a.rb///", ".c") == "a.rb")
+test_ok(File.dirname("a") == ".")
+test_ok(File.dirname("/") == "/")
+test_ok(File.dirname("/a") == "/")
+test_ok(File.dirname("a/b") == "a")
+test_ok(File.dirname("a/b/c") == "a/b")
+test_ok(File.dirname("/a/b/c") == "/a/b")
+test_ok(File.dirname("/a/b/") == "/a")
+test_ok(File.dirname("/a/b///") == "/a")
+case Dir.pwd
+when %r'\A\w:'
+  test_ok(/\A\w:\/\z/ =~ File.expand_path(".", "/"))
+  test_ok(/\A\w:\/a\z/ =~ File.expand_path("a", "/"))
+  dosish = true
+when %r'\A//'
+  test_ok(%r'\A//[^/]+/[^/]+\z' =~ File.expand_path(".", "/"))
+  test_ok(%r'\A//[^/]+/[^/]+/a\z' =~ File.expand_path(".", "/"))
+  dosish = true
+else
+  test_ok(File.expand_path(".", "/") == "/")
+  test_ok(File.expand_path("sub", "/") == "/sub")
+end
+if dosish
+  test_ok(File.expand_path("/", "//machine/share/sub") == "//machine/share")
+  test_ok(File.expand_path("/dir", "//machine/share/sub") == "//machine/share/dir")
+  test_ok(File.expand_path("/", "z:/sub") == "z:/")
+  test_ok(File.expand_path("/dir", "z:/sub") == "z:/dir")
+end
+test_ok(File.expand_path(".", "//") == "//")
+test_ok(File.expand_path("sub", "//") == "//sub")
+
+# test_check "Proc#binding"
+ObjectSpace.each_object(Proc){|o|
+  begin
+    b = o.binding
+    eval 'self', b
+  rescue ArgumentError
+  end
+}
+
+test_check "gc"
+begin
+  1.upto(10000) {
+    tmp = [0,1,2,3,4,5,6,7,8,9]
+  }
+  tmp = nil
+  test_ok true
+rescue
+  test_ok false
+end
+class S
+  def initialize(a)
+    @a = a
+  end
+end
+l=nil
+100000.times {
+  l = S.new(l)
+}
+GC.start
+test_ok true   # reach here or dumps core
+l = []
+100000.times {
+  l.push([l])
+}
+GC.start
+test_ok true   # reach here or dumps core
+
+ObjectSpace.each_object{|o|
+  o.class.name
+}
+
+test_ok true   # reach here or dumps core
+
+PROGRESS.finish
+if $failed > 0
+  printf "not ok/test: %d failed %d\n", $ntest, $failed
+else
+  printf "end of test(test: %d)\n", $ntest
+end
diff --git a/benchmark/README.md b/benchmark/README.md
new file mode 100644
index 0000000000..39a5aa139b
--- /dev/null
+++ b/benchmark/README.md
@@ -0,0 +1,72 @@
+# ruby/benchmark
+
+This directory has benchmark definitions to be run with
+[benchmark\_driver.gem](https://github.com/benchmark-driver/benchmark-driver).
+
+## Normal usage
+
+Execute `gem install benchmark_driver` and run a command like:
+
+```bash
+# Run a benchmark script with the ruby in the $PATH
+benchmark-driver benchmark/app_fib.rb
+
+# Run benchmark scripts with multiple Ruby executables or options
+benchmark-driver benchmark/*.rb -e /path/to/ruby -e '/path/to/ruby --jit'
+
+# Or compare Ruby versions managed by rbenv
+benchmark-driver benchmark/*.rb --rbenv '2.5.1;2.6.0-preview2 --jit'
+
+# You can collect many metrics in many ways
+benchmark-driver benchmark/*.rb --runner memory --output markdown
+
+# Some are defined with YAML for complex setup or accurate measurement
+benchmark-driver benchmark/*.yml
+```
+
+See also:
+
+```console
+Usage: benchmark-driver [options] RUBY|YAML...
+    -r, --runner TYPE                Specify runner type: ips, time, memory, once (default: ips)
+    -o, --output TYPE                Specify output type: compare, simple, markdown, record (default: compare)
+    -e, --executables EXECS          Ruby executables (e1::path1 arg1; e2::path2 arg2;...)
+        --rbenv VERSIONS             Ruby executables in rbenv (x.x.x arg1;y.y.y arg2;...)
+        --repeat-count NUM           Try benchmark NUM times and use the fastest result or the worst memory usage
+        --repeat-result TYPE         Yield "best", "average" or "worst" result with --repeat-count (default: best)
+        --bundler                    Install and use gems specified in Gemfile
+        --filter REGEXP              Filter out benchmarks with given regexp
+        --run-duration SECONDS       Warmup estimates loop_count to run for this duration (default: 3)
+    -v, --verbose                    Verbose mode. Multiple -v options increase visilibity (max: 2)
+```
+
+## make benchmark
+
+Using `make benchmark`, `make update-benchmark-driver` automatically downloads
+the supported version of benchmark\_driver, and it runs benchmarks with the downloaded
+benchmark\_driver.
+
+```bash
+# Run all benchmarks with the ruby in the $PATH and the built ruby
+make benchmark
+
+# Or compare with specific ruby binary
+make benchmark COMPARE_RUBY="/path/to/ruby --jit"
+
+# Run vm benchmarks
+make benchmark ITEM=vm
+
+# Run some limited benchmarks in ITEM-matched files
+make benchmark ITEM=vm OPTS=--filter=block
+
+# You can specify the benchmark by an exact filename instead of using the default argument:
+# ARGS = $$(find $(srcdir)/benchmark -maxdepth 1 -name '*$(ITEM)*.yml' -o -name '*$(ITEM)*.rb')
+make benchmark ARGS=benchmark/erb_render.yml
+
+# You can specify any option via $OPTS
+make benchmark OPTS="--help"
+
+# With `make benchmark`, some special runner plugins are available:
+#   -r peak, -r size, -r total, -r utime, -r stime, -r cutime, -r cstime
+make benchmark ITEM=vm_bigarray OPTS="-r peak"
+```
diff --git a/benchmark/app_answer.rb b/benchmark/app_answer.rb
new file mode 100644
index 0000000000..3cd8a8fd37
--- /dev/null
+++ b/benchmark/app_answer.rb
@@ -0,0 +1,15 @@
+def ack(m, n)
+  if m == 0 then
+    n + 1
+  elsif n == 0 then
+    ack(m - 1, 1)
+  else
+    ack(m - 1, ack(m, n - 1))
+  end
+end
+
+def the_answer_to_life_the_universe_and_everything
+  (ack(3,7).to_s.split(//).inject(0){|s,x| s+x.to_i}.to_s + "2" ).to_i
+end
+
+answer = the_answer_to_life_the_universe_and_everything
diff --git a/benchmark/app_aobench.rb b/benchmark/app_aobench.rb
new file mode 100644
index 0000000000..16296af12b
--- /dev/null
+++ b/benchmark/app_aobench.rb
@@ -0,0 +1,297 @@
+# coding: US-ASCII
+
+# AO render benchmark
+# Original program (C) Syoyo Fujita in Javascript (and other languages)
+#      https://code.google.com/p/aobench/
+# Ruby(yarv2llvm) version by Hideki Miura
+#
+
+IMAGE_WIDTH = 256
+IMAGE_HEIGHT = 256
+NSUBSAMPLES = 2
+NAO_SAMPLES = 8
+
+srand(0)
+
+class Vec
+  def initialize(x, y, z)
+    @x = x
+    @y = y
+    @z = z
+  end
+
+  attr_accessor :x, :y, :z
+
+  def vadd(b)
+    Vec.new(@x + b.x, @y + b.y, @z + b.z)
+  end
+
+  def vsub(b)
+    Vec.new(@x - b.x, @y - b.y, @z - b.z)
+  end
+
+  def vcross(b)
+    Vec.new(@y * b.z - @z * b.y,
+            @z * b.x - @x * b.z,
+            @x * b.y - @y * b.x)
+  end
+
+  def vdot(b)
+    @x * b.x + @y * b.y + @z * b.z
+  end
+
+  def vlength
+    Math.sqrt(@x * @x + @y * @y + @z * @z)
+  end
+
+  def vnormalize
+    len = vlength
+    v = Vec.new(@x, @y, @z)
+    if len > 1.0e-17 then
+      v.x = v.x / len
+      v.y = v.y / len
+      v.z = v.z / len
+    end
+    v
+  end
+end
+
+
+class Sphere
+  def initialize(center, radius)
+    @center = center
+    @radius = radius
+  end
+
+  attr_reader :center, :radius
+
+  def intersect(ray, isect)
+    rs = ray.org.vsub(@center)
+    b = rs.vdot(ray.dir)
+    c = rs.vdot(rs) - (@radius * @radius)
+    d = b * b - c
+    if d > 0.0 then
+      t = - b - Math.sqrt(d)
+
+      if t > 0.0 and t < isect.t then
+        isect.t = t
+        isect.hit = true
+        isect.pl = Vec.new(ray.org.x + ray.dir.x * t,
+                          ray.org.y + ray.dir.y * t,
+                          ray.org.z + ray.dir.z * t)
+        n = isect.pl.vsub(@center)
+        isect.n = n.vnormalize
+      else
+        0.0
+      end
+    end
+    nil
+  end
+end
+
+class Plane
+  def initialize(p, n)
+    @p = p
+    @n = n
+  end
+
+  def intersect(ray, isect)
+    d = -@p.vdot(@n)
+    v = ray.dir.vdot(@n)
+    v0 = v
+    if v < 0.0 then
+      v0 = -v
+    end
+    if v0 < 1.0e-17 then
+      return
+    end
+
+    t = -(ray.org.vdot(@n) + d) / v
+
+    if t > 0.0 and t < isect.t then
+      isect.hit = true
+      isect.t = t
+      isect.n = @n
+      isect.pl = Vec.new(ray.org.x + t * ray.dir.x,
+                        ray.org.y + t * ray.dir.y,
+                        ray.org.z + t * ray.dir.z)
+    end
+    nil
+  end
+end
+
+class Ray
+  def initialize(org, dir)
+    @org = org
+    @dir = dir
+  end
+
+  attr_accessor :org, :dir
+end
+
+class Isect
+  def initialize
+    @t = 10000000.0
+    @hit = false
+    @pl = Vec.new(0.0, 0.0, 0.0)
+    @n = Vec.new(0.0, 0.0, 0.0)
+  end
+
+  attr_accessor :t, :hit, :pl, :n
+end
+
+def clamp(f)
+  i = f * 255.5
+  if i > 255.0 then
+    i = 255.0
+  end
+  if i < 0.0 then
+    i = 0.0
+  end
+  i.to_i
+end
+
+def otherBasis(basis, n)
+  basis[2] = Vec.new(n.x, n.y, n.z)
+  basis[1] = Vec.new(0.0, 0.0, 0.0)
+
+  if n.x < 0.6 and n.x > -0.6 then
+    basis[1].x = 1.0
+  elsif n.y < 0.6 and n.y > -0.6 then
+    basis[1].y = 1.0
+  elsif n.z < 0.6 and n.z > -0.6 then
+    basis[1].z = 1.0
+  else
+    basis[1].x = 1.0
+  end
+
+  basis[0] = basis[1].vcross(basis[2])
+  basis[0] = basis[0].vnormalize
+
+  basis[1] = basis[2].vcross(basis[0])
+  basis[1] = basis[1].vnormalize
+end
+
+class Scene
+  def initialize
+    @spheres = Array.new
+    @spheres[0] = Sphere.new(Vec.new(-2.0, 0.0, -3.5), 0.5)
+    @spheres[1] = Sphere.new(Vec.new(-0.5, 0.0, -3.0), 0.5)
+    @spheres[2] = Sphere.new(Vec.new(1.0, 0.0, -2.2), 0.5)
+    @plane = Plane.new(Vec.new(0.0, -0.5, 0.0), Vec.new(0.0, 1.0, 0.0))
+  end
+
+  def ambient_occlusion(isect)
+    basis = Array.new
+    otherBasis(basis, isect.n)
+
+    ntheta    = NAO_SAMPLES
+    nphi      = NAO_SAMPLES
+    eps       = 0.0001
+    occlusion = 0.0
+
+    p0 = Vec.new(isect.pl.x + eps * isect.n.x,
+                isect.pl.y + eps * isect.n.y,
+                isect.pl.z + eps * isect.n.z)
+    nphi.times do |j|
+      ntheta.times do |i|
+        r = rand
+        phi = 2.0 * 3.14159265 * rand
+        x = Math.cos(phi) * Math.sqrt(1.0 - r)
+        y = Math.sin(phi) * Math.sqrt(1.0 - r)
+        z = Math.sqrt(r)
+
+        rx = x * basis[0].x + y * basis[1].x + z * basis[2].x
+        ry = x * basis[0].y + y * basis[1].y + z * basis[2].y
+        rz = x * basis[0].z + y * basis[1].z + z * basis[2].z
+
+        raydir = Vec.new(rx, ry, rz)
+        ray = Ray.new(p0, raydir)
+
+        occisect = Isect.new
+        @spheres[0].intersect(ray, occisect)
+        @spheres[1].intersect(ray, occisect)
+        @spheres[2].intersect(ray, occisect)
+        @plane.intersect(ray, occisect)
+        if occisect.hit then
+          occlusion = occlusion + 1.0
+        else
+          0.0
+        end
+      end
+    end
+
+    occlusion = (ntheta.to_f * nphi.to_f - occlusion) / (ntheta.to_f * nphi.to_f)
+
+    Vec.new(occlusion, occlusion, occlusion)
+  end
+
+  def render(w, h, nsubsamples)
+    cnt = 0
+    nsf = nsubsamples.to_f
+    h.times do |y|
+      w.times do |x|
+        rad = Vec.new(0.0, 0.0, 0.0)
+
+        # Subsampling
+        nsubsamples.times do |v|
+          nsubsamples.times do |u|
+
+            cnt = cnt + 1
+            wf = w.to_f
+            hf = h.to_f
+            xf = x.to_f
+            yf = y.to_f
+            uf = u.to_f
+            vf = v.to_f
+
+            px = (xf + (uf / nsf) - (wf / 2.0)) / (wf / 2.0)
+            py = -(yf + (vf / nsf) - (hf / 2.0)) / (hf / 2.0)
+
+            eye = Vec.new(px, py, -1.0).vnormalize
+
+            ray = Ray.new(Vec.new(0.0, 0.0, 0.0), eye)
+
+            isect = Isect.new
+            @spheres[0].intersect(ray, isect)
+            @spheres[1].intersect(ray, isect)
+            @spheres[2].intersect(ray, isect)
+            @plane.intersect(ray, isect)
+            if isect.hit then
+              col = ambient_occlusion(isect)
+              rad.x = rad.x + col.x
+              rad.y = rad.y + col.y
+              rad.z = rad.z + col.z
+            end
+          end
+        end
+
+        r = rad.x / (nsf * nsf)
+        g = rad.y / (nsf * nsf)
+        b = rad.z / (nsf * nsf)
+        printf("%c", clamp(r))
+        printf("%c", clamp(g))
+        printf("%c", clamp(b))
+      end
+      nil
+    end
+
+    nil
+  end
+end
+
+alias printf_orig printf
+def printf *args
+  # $fp.printf(*args)
+end
+
+# File.open("ao.ppm", "w") do |fp|
+  # $fp = fp
+  printf("P6\n")
+  printf("%d %d\n", IMAGE_WIDTH, IMAGE_HEIGHT)
+  printf("255\n")
+  Scene.new.render(IMAGE_WIDTH, IMAGE_HEIGHT, NSUBSAMPLES)
+# end
+
+undef printf
+alias printf printf_orig
diff --git a/benchmark/app_erb.yml b/benchmark/app_erb.yml
new file mode 100644
index 0000000000..31e29b7644
--- /dev/null
+++ b/benchmark/app_erb.yml
@@ -0,0 +1,23 @@
+#
+# Create many HTML strings with ERB.
+#
+prelude: |
+  require 'erb'
+
+  data = <<erb
+  <html>
+    <head> <%= title %> </head>
+    <body>
+      <h1> <%= title %> </h1>
+      <p>
+        <%= content %>
+      </p>
+    </body>
+  </html>
+  erb
+
+  title = "hello world!"
+  content = "hello world!\n" * 10
+benchmark:
+  app_erb: ERB.new(data).result(binding)
+loop_count: 15000
diff --git a/benchmark/app_factorial.rb b/benchmark/app_factorial.rb
new file mode 100644
index 0000000000..45f471dfdb
--- /dev/null
+++ b/benchmark/app_factorial.rb
@@ -0,0 +1,11 @@
+def fact(n)
+  if(n > 1)
+    n * fact(n-1)
+  else
+    1
+  end
+end
+
+100.times {
+  fact(5000)
+}
diff --git a/benchmark/app_fib.rb b/benchmark/app_fib.rb
new file mode 100644
index 0000000000..34a7b2e725
--- /dev/null
+++ b/benchmark/app_fib.rb
@@ -0,0 +1,10 @@
+def fib n
+  if n < 3
+    1
+  else
+    fib(n-1) + fib(n-2)
+  end
+end
+
+fib(34)
+
diff --git a/benchmark/app_lc_fizzbuzz.rb b/benchmark/app_lc_fizzbuzz.rb
new file mode 100644
index 0000000000..f09574bbeb
--- /dev/null
+++ b/benchmark/app_lc_fizzbuzz.rb
@@ -0,0 +1,52 @@
+#
+# FizzBuzz program using only lambda calculus
+#
+# This program is quoted from
+#   "Understanding Computation" by Tom Stuart
+#   http://computationbook.com/
+#
+# You can understand why this program works fine by reading this book.
+#
+
+solution = -> k { -> f { -> f { -> x { f[-> y { x[x][y] }] }[-> x { f[-> y { x[x][y] }] }] }[-> f { -> l { -> x { -> g { -> b { b }[-> p { p[-> x { -> y { x } }] }[l]][x][-> y { g[f[-> l { -> p { p[-> x { -> y { y } }] }[-> p { p[-> x { -> y { y } }] }[l]] }[l]][x][g]][-> l { -> p { p[-> x { -> y { x } }] }[-> p { p[-> x { -> y { y } }] }[l]] }[l]][y] }] } } } }][k][-> x { -> y { -> f { f[x][y] } } }[-> x { -> y { x } }][-> x { -> y { x } }]][-> l { -> x { -> l { -> x { -> x { -> y { -> f { f[x][y] } } }[-> x { -> y { y } }][-> x { -> y { -> f { f[x][y] } } }[x][l]] } }[l][f[x]] } }] } }[-> f { -> x { f[-> y { x[x][y] }] }[-> x { f[-> y { x[x][y] }] }] }[-> f { -> m { -> n { -> b { b }[-> m { -> n { -> n { n[-> x { -> x { -> y { y } } }][-> x { -> y { x } }] }[-> m { -> n { n[-> n { -> p { p[-> x { -> y { x } }] }[n[-> p { -> x { -> y { -> f { f[x][y] } } }[-> p { p[-> x { -> y { y } }] }[p]][-> n { -> p { -> x { p[n[p][x]] } } }[-> p { p[-> x { -> y { y } }] }[p]]] }][-> x { -> y { -> f { f[x][y] } } }[-> p { -> x { x } }][-> p { -> x { x } }]]] }][m] } }[m][n]] } }[m][n]][-> x { -> l { -> x { -> x { -> y { -> f { f[x][y] } } }[-> x { -> y { y } }][-> x { -> y { -> f { f[x][y] } } }[x][l]] } }[f[-> n { -> p { -> x { p[n[p][x]] } } }[m]][n]][m][x] }][-> x { -> y { -> f { f[x][y] } } }[-> x { -> y { x } }][-> x { -> y { x } }]] } } }][-> p { -> x { p[x] } }][-> p { -> x { p[p[p[p[p[p[p[p[p[p[p[p[p[p[p[p[p[p[p[p[p[p[p[p[p[p[p[p[p[p[p[p[p[p[p[p[p[p[p[p[p[p[p[p[p[p[p[p[p[p[p[p[p[p[p[p[p[p[p[p[p[p[p[p[p[p[p[p[p[p[p[p[p[p[p[p[p[p[p[p[p[p[p[p[p[p[p[p[p[p[p[p[p[p[p[p[p[p[p[p[x]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]] } }]][-> n { -> b { b }[-> n { n[-> x { -> x { -> y { y } } }][-> x { -> y { x } }] }[-> f { -> x { f[-> y { x[x][y] }] }[-> x { f[-> y { x[x][y] }] }] }[-> f { -> m { -> n { -> b { b }[-> m { -> n { -> n { n[-> x { -> x { -> y { y } } }][-> x { -> y { x } }] }[-> m { -> n { n[-> n { -> p { p[-> x { -> y { x } }] }[n[-> p { -> x { -> y { -> f { f[x][y] } } }[-> p { p[-> x { -> y { y } }] }[p]][-> n { -> p { -> x { p[n[p][x]] } } }[-> p { p[-> x { -> y { y } }] }[p]]] }][-> x { -> y { -> f { f[x][y] } } }[-> p { -> x { x } }][-> p { -> x { x } }]]] }][m] } }[m][n]] } }[n][m]][-> x { f[-> m { -> n { n[-> n { -> p { p[-> x { -> y { x } }] }[n[-> p { -> x { -> y { -> f { f[x][y] } } }[-> p { p[-> x { -> y { y } }] }[p]][-> n { -> p { -> x { p[n[p][x]] } } }[-> p { p[-> x { -> y { y } }] }[p]]] }][-> x { -> y { -> f { f[x][y] } } }[-> p { -> x { x } }][-> p { -> x { x } }]]] }][m] } }[m][n]][n][x] }][m] } } }][n][-> p { -> x { p[p[p[p[p[p[p[p[p[p[p[p[p[p[p[x]]]]]]]]]]]]]]] } }]]][-> l { -> x { -> x { -> y { -> f { f[x][y] } } }[-> x { -> y { y } }][-> x { -> y { -> f { f[x][y] } } }[x][l]] } }[-> l { -> x { -> x { -> y { -> f { f[x][y] } } }[-> x { -> y { y } }][-> x { -> y { -> f { f[x][y] } } }[x][l]] } }[-> l { -> x { -> x { -> y { -> f { f[x][y] } } }[-> x { -> y { y } }][-> x { -> y { -> f { f[x][y] } } }[x][l]] } }[-> l { -> x { -> x { -> y { -> f { f[x][y] } } }[-> x { -> y { y } }][-> x { -> y { -> f { f[x][y] } } }[x][l]] } }[-> l { -> x { -> x { -> y { -> f { f[x][y] } } }[-> x { -> y { y } }][-> x { -> y { -> f { f[x][y] } } }[x][l]] } }[-> l { -> x { -> x { -> y { -> f { f[x][y] } } }[-> x { -> y { y } }][-> x { -> y { -> f { f[x][y] } } }[x][l]] } }[-> l { -> x { -> x { -> y { -> f { f[x][y] } } }[-> x { -> y { y } }][-> x { -> y { -> f { f[x][y] } } }[x][l]] } }[-> l { -> x { -> x { -> y { -> f { f[x][y] } } }[-> x { -> y { y } }][-> x { -> y { -> f { f[x][y] } } }[x][l]] } }[-> x { -> y { -> f { f[x][y] } } }[-> x { -> y { x } }][-> x { -> y { x } }]][-> n { -> p { -> x { p[n[p][x]] } } }[-> n { -> p { -> x { p[n[p][x]] } } }[-> n { -> p { -> x { p[n[p][x]] } } }[-> n { -> p { -> x { p[n[p][x]] } } }[-> m { -> n { n[-> m { -> n { n[-> n { -> p { -> x { p[n[p][x]] } } }][m] } }[m]][-> p { -> x { x } }] } }[-> p { -> x { p[p[x]] } }][-> p { -> x { p[p[p[p[p[x]]]]] } }]]]]]]][-> n { -> p { -> x { p[n[p][x]] } } }[-> n { -> p { -> x { p[n[p][x]] } } }[-> n { -> p { -> x { p[n[p][x]] } } }[-> n { -> p { -> x { p[n[p][x]] } } }[-> m { -> n { n[-> m { -> n { n[-> n { -> p { -> x { p[n[p][x]] } } }][m] } }[m]][-> p { -> x { x } }] } }[-> p { -> x { p[p[x]] } }][-> p { -> x { p[p[p[p[p[x]]]]] } }]]]]]]][-> n { -> p { -> x { p[n[p][x]] } } }[-> n { -> p { -> x { p[n[p][x]] } } }[-> n { -> p { -> x { p[n[p][x]] } } }[-> m { -> n { n[-> m { -> n { n[-> n { -> p { -> x { p[n[p][x]] } } }][m] } }[m]][-> p { -> x { x } }] } }[-> p { -> x { p[p[x]] } }][-> p { -> x { p[p[p[p[p[x]]]]] } }]]]]]][-> m { -> n { n[-> m { -> n { n[-> n { -> p { -> x { p[n[p][x]] } } }][m] } }[m]][-> p { -> x { x } }] } }[-> p { -> x { p[p[x]] } }][-> p { -> x { p[p[p[p[p[x]]]]] } }]]][-> n { -> p { -> x { p[n[p][x]] } } }[-> n { -> p { -> x { p[n[p][x]] } } }[-> n { -> p { -> x { p[n[p][x]] } } }[-> n { -> p { -> x { p[n[p][x]] } } }[-> m { -> n { n[-> m { -> n { n[-> n { -> p { -> x { p[n[p][x]] } } }][m] } }[m]][-> p { -> x { x } }] } }[-> p { -> x { p[p[x]] } }][-> p { -> x { p[p[p[p[p[x]]]]] } }]]]]]]][-> n { -> p { -> x { p[n[p][x]] } } }[-> n { -> p { -> x { p[n[p][x]] } } }[-> n { -> p { -> x { p[n[p][x]] } } }[-> n { -> p { -> x { p[n[p][x]] } } }[-> m { -> n { n[-> m { -> n { n[-> n { -> p { -> x { p[n[p][x]] } } }][m] } }[m]][-> p { -> x { x } }] } }[-> p { -> x { p[p[x]] } }][-> p { -> x { p[p[p[p[p[x]]]]] } }]]]]]]][-> n { -> p { -> x { p[n[p][x]] } } }[-> n { -> p { -> x { p[n[p][x]] } } }[-> m { -> n { n[-> m { -> n { n[-> n { -> p { -> x { p[n[p][x]] } } }][m] } }[m]][-> p { -> x { x } }] } }[-> p { -> x { p[p[x]] } }][-> p { -> x { p[p[p[p[p[x]]]]] } }]]]]][-> n { -> p { -> x { p[n[p][x]] } } }[-> m { -> n { n[-> m { -> n { n[-> n { -> p { -> x { p[n[p][x]] } } }][m] } }[m]][-> p { -> x { x } }] } }[-> p { -> x { p[p[x]] } }][-> p { -> x { p[p[p[p[p[x]]]]] } }]]]][-> b { b }[-> n { n[-> x { -> x { -> y { y } } }][-> x { -> y { x } }] }[-> f { -> x { f[-> y { x[x][y] }] }[-> x { f[-> y { x[x][y] }] }] }[-> f { -> m { -> n { -> b { b }[-> m { -> n { -> n { n[-> x { -> x { -> y { y } } }][-> x { -> y { x } }] }[-> m { -> n { n[-> n { -> p { p[-> x { -> y { x } }] }[n[-> p { -> x { -> y { -> f { f[x][y] } } }[-> p { p[-> x { -> y { y } }] }[p]][-> n { -> p { -> x { p[n[p][x]] } } }[-> p { p[-> x { -> y { y } }] }[p]]] }][-> x { -> y { -> f { f[x][y] } } }[-> p { -> x { x } }][-> p { -> x { x } }]]] }][m] } }[m][n]] } }[n][m]][-> x { f[-> m { -> n { n[-> n { -> p { p[-> x { -> y { x } }] }[n[-> p { -> x { -> y { -> f { f[x][y] } } }[-> p { p[-> x { -> y { y } }] }[p]][-> n { -> p { -> x { p[n[p][x]] } } }[-> p { p[-> x { -> y { y } }] }[p]]] }][-> x { -> y { -> f { f[x][y] } } }[-> p { -> x { x } }][-> p { -> x { x } }]]] }][m] } }[m][n]][n][x] }][m] } } }][n][-> p { -> x { p[p[p[x]]] } }]]][-> l { -> x { -> x { -> y { -> f { f[x][y] } } }[-> x { -> y { y } }][-> x { -> y { -> f { f[x][y] } } }[x][l]] } }[-> l { -> x { -> x { -> y { -> f { f[x][y] } } }[-> x { -> y { y } }][-> x { -> y { -> f { f[x][y] } } }[x][l]] } }[-> l { -> x { -> x { -> y { -> f { f[x][y] } } }[-> x { -> y { y } }][-> x { -> y { -> f { f[x][y] } } }[x][l]] } }[-> l { -> x { -> x { -> y { -> f { f[x][y] } } }[-> x { -> y { y } }][-> x { -> y { -> f { f[x][y] } } }[x][l]] } }[-> x { -> y { -> f { f[x][y] } } }[-> x { -> y { x } }][-> x { -> y { x } }]][-> n { -> p { -> x { p[n[p][x]] } } }[-> n { -> p { -> x { p[n[p][x]] } } }[-> n { -> p { -> x { p[n[p][x]] } } }[-> n { -> p { -> x { p[n[p][x]] } } }[-> m { -> n { n[-> m { -> n { n[-> n { -> p { -> x { p[n[p][x]] } } }][m] } }[m]][-> p { -> x { x } }] } }[-> p { -> x { p[p[x]] } }][-> p { -> x { p[p[p[p[p[x]]]]] } }]]]]]]][-> n { -> p { -> x { p[n[p][x]] } } }[-> n { -> p { -> x { p[n[p][x]] } } }[-> n { -> p { -> x { p[n[p][x]] } } }[-> n { -> p { -> x { p[n[p][x]] } } }[-> m { -> n { n[-> m { -> n { n[-> n { -> p { -> x { p[n[p][x]] } } }][m] } }[m]][-> p { -> x { x } }] } }[-> p { -> x { p[p[x]] } }][-> p { -> x { p[p[p[p[p[x]]]]] } }]]]]]]][-> n { -> p { -> x { p[n[p][x]] } } }[-> n { -> p { -> x { p[n[p][x]] } } }[-> m { -> n { n[-> m { -> n { n[-> n { -> p { -> x { p[n[p][x]] } } }][m] } }[m]][-> p { -> x { x } }] } }[-> p { -> x { p[p[x]] } }][-> p { -> x { p[p[p[p[p[x]]]]] } }]]]]][-> n { -> p { -> x { p[n[p][x]] } } }[-> m { -> n { n[-> m { -> n { n[-> n { -> p { -> x { p[n[p][x]] } } }][m] } }[m]][-> p { -> x { x } }] } }[-> p { -> x { p[p[x]] } }][-> p { -> x { p[p[p[p[p[x]]]]] } }]]]][-> b { b }[-> n { n[-> x { -> x { -> y { y } } }][-> x { -> y { x } }] }[-> f { -> x { f[-> y { x[x][y] }] }[-> x { f[-> y { x[x][y] }] }] }[-> f { -> m { -> n { -> b { b }[-> m { -> n { -> n { n[-> x { -> x { -> y { y } } }][-> x { -> y { x } }] }[-> m { -> n { n[-> n { -> p { p[-> x { -> y { x } }] }[n[-> p { -> x { -> y { -> f { f[x][y] } } }[-> p { p[-> x { -> y { y } }] }[p]][-> n { -> p { -> x { p[n[p][x]] } } }[-> p { p[-> x { -> y { y } }] }[p]]] }][-> x { -> y { -> f { f[x][y] } } }[-> p { -> x { x } }][-> p { -> x { x } }]]] }][m] } }[m][n]] } }[n][m]][-> x { f[-> m { -> n { n[-> n { -> p { p[-> x { -> y { x } }] }[n[-> p { -> x { -> y { -> f { f[x][y] } } }[-> p { p[-> x { -> y { y } }] }[p]][-> n { -> p { -> x { p[n[p][x]] } } }[-> p { p[-> x { -> y { y } }] }[p]]] }][-> x { -> y { -> f { f[x][y] } } }[-> p { -> x { x } }][-> p { -> x { x } }]]] }][m] } }[m][n]][n][x] }][m] } } }][n][-> p { -> x { p[p[p[p[p[x]]]]] } }]]][-> l { -> x { -> x { -> y { -> f { f[x][y] } } }[-> x { -> y { y } }][-> x { -> y { -> f { f[x][y] } } }[x][l]] } }[-> l { -> x { -> x { -> y { -> f { f[x][y] } } }[-> x { -> y { y } }][-> x { -> y { -> f { f[x][y] } } }[x][l]] } }[-> l { -> x { -> x { -> y { -> f { f[x][y] } } }[-> x { -> y { y } }][-> x { -> y { -> f { f[x][y] } } }[x][l]] } }[-> l { -> x { -> x { -> y { -> f { f[x][y] } } }[-> x { -> y { y } }][-> x { -> y { -> f { f[x][y] } } }[x][l]] } }[-> x { -> y { -> f { f[x][y] } } }[-> x { -> y { x } }][-> x { -> y { x } }]][-> n { -> p { -> x { p[n[p][x]] } } }[-> n { -> p { -> x { p[n[p][x]] } } }[-> n { -> p { -> x { p[n[p][x]] } } }[-> n { -> p { -> x { p[n[p][x]] } } }[-> m { -> n { n[-> m { -> n { n[-> n { -> p { -> x { p[n[p][x]] } } }][m] } }[m]][-> p { -> x { x } }] } }[-> p { -> x { p[p[x]] } }][-> p { -> x { p[p[p[p[p[x]]]]] } }]]]]]]][-> n { -> p { -> x { p[n[p][x]] } } }[-> n { -> p { -> x { p[n[p][x]] } } }[-> n { -> p { -> x { p[n[p][x]] } } }[-> n { -> p { -> x { p[n[p][x]] } } }[-> m { -> n { n[-> m { -> n { n[-> n { -> p { -> x { p[n[p][x]] } } }][m] } }[m]][-> p { -> x { x } }] } }[-> p { -> x { p[p[x]] } }][-> p { -> x { p[p[p[p[p[x]]]]] } }]]]]]]][-> n { -> p { -> x { p[n[p][x]] } } }[-> n { -> p { -> x { p[n[p][x]] } } }[-> n { -> p { -> x { p[n[p][x]] } } }[-> m { -> n { n[-> m { -> n { n[-> n { -> p { -> x { p[n[p][x]] } } }][m] } }[m]][-> p { -> x { x } }] } }[-> p { -> x { p[p[x]] } }][-> p { -> x { p[p[p[p[p[x]]]]] } }]]]]]][-> m { -> n { n[-> m { -> n { n[-> n { -> p { -> x { p[n[p][x]] } } }][m] } }[m]][-> p { -> x { x } }] } }[-> p { -> x { p[p[x]] } }][-> p { -> x { p[p[p[p[p[x]]]]] } }]]][-> f { -> x { f[-> y { x[x][y] }] }[-> x { f[-> y { x[x][y] }] }] }[-> f { -> n { -> l { -> x { -> f { -> x { f[-> y { x[x][y] }] }[-> x { f[-> y { x[x][y] }] }] }[-> f { -> l { -> x { -> g { -> b { b }[-> p { p[-> x { -> y { x } }] }[l]][x][-> y { g[f[-> l { -> p { p[-> x { -> y { y } }] }[-> p { p[-> x { -> y { y } }] }[l]] }[l]][x][g]][-> l { -> p { p[-> x { -> y { x } }] }[-> p { p[-> x { -> y { y } }] }[l]] }[l]][y] }] } } } }][l][-> l { -> x { -> x { -> y { -> f { f[x][y] } } }[-> x { -> y { y } }][-> x { -> y { -> f { f[x][y] } } }[x][l]] } }[-> x { -> y { -> f { f[x][y] } } }[-> x { -> y { x } }][-> x { -> y { x } }]][x]][-> l { -> x { -> x { -> y { -> f { f[x][y] } } }[-> x { -> y { y } }][-> x { -> y { -> f { f[x][y] } } }[x][l]] } }] } }[-> b { b }[-> m { -> n { -> n { n[-> x { -> x { -> y { y } } }][-> x { -> y { x } }] }[-> m { -> n { n[-> n { -> p { p[-> x { -> y { x } }] }[n[-> p { -> x { -> y { -> f { f[x][y] } } }[-> p { p[-> x { -> y { y } }] }[p]][-> n { -> p { -> x { p[n[p][x]] } } }[-> p { p[-> x { -> y { y } }] }[p]]] }][-> x { -> y { -> f { f[x][y] } } }[-> p { -> x { x } }][-> p { -> x { x } }]]] }][m] } }[m][n]] } }[n][-> n { -> p { p[-> x { -> y { x } }] }[n[-> p { -> x { -> y { -> f { f[x][y] } } }[-> p { p[-> x { -> y { y } }] }[p]][-> n { -> p { -> x { p[n[p][x]] } } }[-> p { p[-> x { -> y { y } }] }[p]]] }][-> x { -> y { -> f { f[x][y] } } }[-> p { -> x { x } }][-> p { -> x { x } }]]] }[-> m { -> n { n[-> m { -> n { n[-> n { -> p { -> x { p[n[p][x]] } } }][m] } }[m]][-> p { -> x { x } }] } }[-> p { -> x { p[p[x]] } }][-> p { -> x { p[p[p[p[p[x]]]]] } }]]]][-> x { -> y { -> f { f[x][y] } } }[-> x { -> y { x } }][-> x { -> y { x } }]][-> x { f[-> f { -> x { f[-> y { x[x][y] }] }[-> x { f[-> y { x[x][y] }] }] }[-> f { -> m { -> n { -> b { b }[-> m { -> n { -> n { n[-> x { -> x { -> y { y } } }][-> x { -> y { x } }] }[-> m { -> n { n[-> n { -> p { p[-> x { -> y { x } }] }[n[-> p { -> x { -> y { -> f { f[x][y] } } }[-> p { p[-> x { -> y { y } }] }[p]][-> n { -> p { -> x { p[n[p][x]] } } }[-> p { p[-> x { -> y { y } }] }[p]]] }][-> x { -> y { -> f { f[x][y] } } }[-> p { -> x { x } }][-> p { -> x { x } }]]] }][m] } }[m][n]] } }[n][m]][-> x { -> n { -> p { -> x { p[n[p][x]] } } }[f[-> m { -> n { n[-> n { -> p { p[-> x { -> y { x } }] }[n[-> p { -> x { -> y { -> f { f[x][y] } } }[-> p { p[-> x { -> y { y } }] }[p]][-> n { -> p { -> x { p[n[p][x]] } } }[-> p { p[-> x { -> y { y } }] }[p]]] }][-> x { -> y { -> f { f[x][y] } } }[-> p { -> x { x } }][-> p { -> x { x } }]]] }][m] } }[m][n]][n]][x] }][-> p { -> x { x } }] } } }][n][-> m { -> n { n[-> m { -> n { n[-> n { -> p { -> x { p[n[p][x]] } } }][m] } }[m]][-> p { -> x { x } }] } }[-> p { -> x { p[p[x]] } }][-> p { -> x { p[p[p[p[p[x]]]]] } }]]][x] }]][-> f { -> x { f[-> y { x[x][y] }] }[-> x { f[-> y { x[x][y] }] }] }[-> f { -> m { -> n { -> b { b }[-> m { -> n { -> n { n[-> x { -> x { -> y { y } } }][-> x { -> y { x } }] }[-> m { -> n { n[-> n { -> p { p[-> x { -> y { x } }] }[n[-> p { -> x { -> y { -> f { f[x][y] } } }[-> p { p[-> x { -> y { y } }] }[p]][-> n { -> p { -> x { p[n[p][x]] } } }[-> p { p[-> x { -> y { y } }] }[p]]] }][-> x { -> y { -> f { f[x][y] } } }[-> p { -> x { x } }][-> p { -> x { x } }]]] }][m] } }[m][n]] } }[n][m]][-> x { f[-> m { -> n { n[-> n { -> p { p[-> x { -> y { x } }] }[n[-> p { -> x { -> y { -> f { f[x][y] } } }[-> p { p[-> x { -> y { y } }] }[p]][-> n { -> p { -> x { p[n[p][x]] } } }[-> p { p[-> x { -> y { y } }] }[p]]] }][-> x { -> y { -> f { f[x][y] } } }[-> p { -> x { x } }][-> p { -> x { x } }]]] }][m] } }[m][n]][n][x] }][m] } } }][n][-> m { -> n { n[-> m { -> n { n[-> n { -> p { -> x { p[n[p][x]] } } }][m] } }[m]][-> p { -> x { x } }] } }[-> p { -> x { p[p[x]] } }][-> p { -> x { p[p[p[p[p[x]]]]] } }]]] } }][n]]]] }]
+
+FIRST     = -> l { LEFT[RIGHT[l]] }
+IF        = -> b { b }
+LEFT      = -> p { p[-> x { -> y { x } } ] }
+RIGHT     = -> p { p[-> x { -> y { y } } ] }
+IS_EMPTY  = LEFT
+REST      = -> l { RIGHT[RIGHT[l]] }
+
+def to_integer(proc)
+  proc[-> n { n + 1 }][0]
+end
+
+def to_boolean(proc)
+  IF[proc][true][false]
+end
+
+def to_array(proc)
+  array = []
+
+  until to_boolean(IS_EMPTY[proc])
+    array.push(FIRST[proc])
+    proc = REST[proc]
+  end
+
+  array
+end
+
+def to_char(c)
+  '0123456789BFiuz'.slice(to_integer(c))
+end
+
+def to_string(s)
+  to_array(s).map { |c| to_char(c) }.join
+end
+
+answer = to_array(solution).map do |p|
+  to_string(p)
+end
+
+answer_ary = answer.to_a
+# puts answer_ary
diff --git a/benchmark/app_mandelbrot.rb b/benchmark/app_mandelbrot.rb
new file mode 100644
index 0000000000..801b75e8e2
--- /dev/null
+++ b/benchmark/app_mandelbrot.rb
@@ -0,0 +1,23 @@
+require 'complex'
+
+def mandelbrot? z
+  i = 0
+  while i<100
+    i += 1
+    z = z * z
+    return false if z.abs > 2
+  end
+  true
+end
+
+ary = []
+
+(0..1000).each{|dx|
+  (0..1000).each{|dy|
+    x = dx / 50.0
+    y = dy / 50.0
+    c = Complex(x, y)
+    ary << c if mandelbrot?(c)
+  }
+}
+
diff --git a/benchmark/app_pentomino.rb b/benchmark/app_pentomino.rb
new file mode 100644
index 0000000000..47be7b203f
--- /dev/null
+++ b/benchmark/app_pentomino.rb
@@ -0,0 +1,130 @@
+#!/usr/local/bin/ruby
+# This program is contributed by Shin Nishiyama
+
+
+# modified by K.Sasada
+
+NP = 5
+ROW = 8 + NP
+COL = 8
+
+$p = []
+$b = []
+$no = 0
+
+def piece(n, a, nb)
+  nb.each{|x|
+    a[n] = x
+    if n == NP-1
+      $p << [a.sort]
+    else
+      nbc=nb.dup
+      [-ROW, -1, 1, ROW].each{|d|
+        if x+d > 0 and not a.include?(x+d) and not nbc.include?(x+d)
+          nbc << x+d
+        end
+      }
+      nbc.delete x
+      piece(n+1,a[0..n],nbc)
+    end
+  }
+end
+
+def kikaku(a)
+  a.collect {|x| x - a[0]}
+end
+def ud(a)
+  kikaku(a.collect {|x| ((x+NP)%ROW)-ROW*((x+NP)/ROW) }.sort)
+end
+def rl(a)
+  kikaku(a.collect {|x| ROW*((x+NP)/ROW)+ROW-((x+NP)%ROW)}.sort)
+end
+def xy(a)
+  kikaku(a.collect {|x| ROW*((x+NP)%ROW) + (x+NP)/ROW }.sort)
+end
+
+def mkpieces
+  piece(0,[],[0])
+  $p.each do |a|
+    a0 = a[0]
+    a[1] = ud(a0)
+    a[2] = rl(a0)
+    a[3] = ud(rl(a0))
+    a[4] = xy(a0)
+    a[5] = ud(xy(a0))
+    a[6] = rl(xy(a0))
+    a[7] = ud(rl(xy(a0)))
+    a.sort!
+    a.uniq!
+  end
+  $p.uniq!.sort! {|x,y| x[0] <=> y[0] }
+end
+
+def mkboard
+  (0...ROW*COL).each{|i|
+    if i % ROW >= ROW-NP
+      $b[i] = -2
+    else
+      $b[i] = -1
+    end
+    $b[3*ROW+3]=$b[3*ROW+4]=$b[4*ROW+3]=$b[4*ROW+4]=-2
+  }
+end
+
+def pboard
+  return # skip print
+  print "No. #$no\n"
+  (0...COL).each{|i|
+    print "|"
+    (0...ROW-NP).each{|j|
+      x = $b[i*ROW+j]
+      if x < 0
+        print "..|"
+      else
+        printf "%2d|",x+1
+      end
+    }
+    print "\n"
+  }
+  print "\n"
+end
+
+$pnum=[]
+def setpiece(a,pos)
+  if a.length == $p.length then
+    $no += 1
+    pboard
+    return
+  end
+  while $b[pos] != -1
+    pos += 1
+  end
+  ($pnum - a).each do |i|
+    $p[i].each do |x|
+      f = 0
+      x.each{|s|
+        if $b[pos+s] != -1
+          f=1
+          break
+        end
+      }
+      if f == 0 then
+        x.each{|s|
+          $b[pos+s] = i
+        }
+        a << i
+        setpiece(a.dup, pos)
+        a.pop
+        x.each{|s|
+          $b[pos+s] = -1
+        }
+      end
+    end
+  end
+end
+
+mkpieces
+mkboard
+$p[4] = [$p[4][0]]
+$pnum = (0...$p.length).to_a
+setpiece([],0)
diff --git a/benchmark/app_raise.rb b/benchmark/app_raise.rb
new file mode 100644
index 0000000000..5db8f95d50
--- /dev/null
+++ b/benchmark/app_raise.rb
@@ -0,0 +1,8 @@
+i = 0
+while i<300000
+  i += 1
+  begin
+    raise
+  rescue
+  end
+end
diff --git a/benchmark/app_strconcat.rb b/benchmark/app_strconcat.rb
new file mode 100644
index 0000000000..7eed7c1aed
--- /dev/null
+++ b/benchmark/app_strconcat.rb
@@ -0,0 +1,5 @@
+i = 0
+while i<2_000_000
+  "#{1+1} #{1+1} #{1+1}"
+  i += 1
+end
diff --git a/benchmark/app_tak.rb b/benchmark/app_tak.rb
new file mode 100644
index 0000000000..efe5380f4e
--- /dev/null
+++ b/benchmark/app_tak.rb
@@ -0,0 +1,13 @@
+
+def tak x, y, z
+  unless y < x
+    z
+  else
+    tak( tak(x-1, y, z),
+         tak(y-1, z, x),
+         tak(z-1, x, y))
+  end
+end
+
+tak(18, 9, 0)
+
diff --git a/benchmark/app_tarai.rb b/benchmark/app_tarai.rb
new file mode 100644
index 0000000000..4c146f5ccf
--- /dev/null
+++ b/benchmark/app_tarai.rb
@@ -0,0 +1,10 @@
+def tarai( x, y, z )
+  if x <= y
+  then y
+  else tarai(tarai(x-1, y, z),
+             tarai(y-1, z, x),
+             tarai(z-1, x, y))
+  end
+end
+
+tarai(12, 6, 0)
diff --git a/benchmark/app_uri.rb b/benchmark/app_uri.rb
new file mode 100644
index 0000000000..586edfd5dc
--- /dev/null
+++ b/benchmark/app_uri.rb
@@ -0,0 +1,8 @@
+require 'uri'
+
+100_000.times{
+  uri = URI.parse('http://www.ruby-lang.org')
+  uri.scheme
+  uri.host
+  uri.port
+}
diff --git a/benchmark/array_flatten.yml b/benchmark/array_flatten.yml
new file mode 100644
index 0000000000..88ef544ba0
--- /dev/null
+++ b/benchmark/array_flatten.yml
@@ -0,0 +1,19 @@
+prelude: |
+  small_flat_ary = 5.times.to_a
+  large_flat_ary = 100.times.to_a
+  small_pairs_ary = [[1, 2]] * 5
+  large_pairs_ary = [[1, 2]] * 100
+  mostly_flat_ary = 100.times.to_a.push([101, 102])
+
+benchmark:
+  small_flat_ary.flatten: small_flat_ary.flatten
+  small_flat_ary.flatten!: small_flat_ary.flatten!
+  large_flat_ary.flatten: large_flat_ary.flatten
+  large_flat_ary.flatten!: large_flat_ary.flatten!
+  small_pairs_ary.flatten: small_pairs_ary.flatten
+  small_pairs_ary.flatten!: small_pairs_ary.dup.flatten!
+  large_pairs_ary.flatten: large_pairs_ary.flatten
+  large_pairs_ary.flatten!: large_pairs_ary.dup.flatten!
+  mostly_flat_ary.flatten: mostly_flat_ary.flatten
+  mostly_flat_ary.flatten!: mostly_flat_ary.dup.flatten!
+loop_count: 10000
diff --git a/benchmark/array_intersection.yml b/benchmark/array_intersection.yml
new file mode 100644
index 0000000000..26705323fd
--- /dev/null
+++ b/benchmark/array_intersection.yml
@@ -0,0 +1,14 @@
+prelude: |
+  small1 = [1, 2, 3]
+  small2 = [1, 2, 3, 4, 5]
+  small3 = [2, 3, 4, 5]
+  small4 = [2]
+  big1 = [1, 2, 3, 4] * 64
+  big2 = [1, 2, 3] * 64
+  big3 = [1, 2] * 64
+
+benchmark:
+  small-&: small1 & small2 & small3 & small4
+  small-intersection: small1.intersection(small2, small3, small4)
+  big-&: big1 & big2 & big3
+  big-intersection: big1.intersection(big2, big3)
diff --git a/benchmark/array_max_float.yml b/benchmark/array_max_float.yml
new file mode 100644
index 0000000000..ace1ae2e14
--- /dev/null
+++ b/benchmark/array_max_float.yml
@@ -0,0 +1,30 @@
+prelude: |
+  ary2 = 2.times.map(&:to_f).shuffle
+  ary10 = 10.times.map(&:to_f).shuffle
+  ary100 = 100.times.map(&:to_f).shuffle
+  ary500 = 500.times.map(&:to_f).shuffle
+  ary1000 = 1000.times.map(&:to_f).shuffle
+  ary2000 = 2500.times.map(&:to_f).shuffle
+  ary3000 = 2500.times.map(&:to_f).shuffle
+  ary5000 = 5000.times.map(&:to_f).shuffle
+  ary10000 = 10000.times.map(&:to_f).shuffle
+  ary20000 = 20000.times.map(&:to_f).shuffle
+  ary50000 = 50000.times.map(&:to_f).shuffle
+  ary100000 = 100000.times.map(&:to_f).shuffle
+
+benchmark:
+  ary2.max: ary2.max
+  ary10.max: ary10.max
+  ary100.max: ary100.max
+  ary500.max: ary500.max
+  ary1000.max: ary1000.max
+  ary2000.max: ary2000.max
+  ary3000.max: ary3000.max
+  ary5000.max: ary5000.max
+  ary10000.max: ary10000.max
+  ary20000.max: ary20000.max
+  ary50000.max: ary50000.max
+  ary100000.max: ary100000.max
+
+loop_count: 10000
+
diff --git a/benchmark/array_max_int.yml b/benchmark/array_max_int.yml
new file mode 100644
index 0000000000..acd83684d0
--- /dev/null
+++ b/benchmark/array_max_int.yml
@@ -0,0 +1,31 @@
+prelude: |
+  ary2 = 2.times.to_a.shuffle
+  ary10 = 10.times.to_a.shuffle
+  ary100 = 100.times.to_a.shuffle
+  ary500 = 500.times.to_a.shuffle
+  ary1000 = 1000.times.to_a.shuffle
+  ary2000 = 2500.times.to_a.shuffle
+  ary3000 = 2500.times.to_a.shuffle
+  ary5000 = 5000.times.to_a.shuffle
+  ary10000 = 10000.times.to_a.shuffle
+  ary20000 = 20000.times.to_a.shuffle
+  ary50000 = 50000.times.to_a.shuffle
+  ary100000 = 100000.times.to_a.shuffle
+  ary1000000 = 1000000.times.to_a.shuffle
+
+benchmark:
+  ary2.max: ary2.max
+  ary10.max: ary10.max
+  ary100.max: ary100.max
+  ary500.max: ary500.max
+  ary1000.max: ary1000.max
+  ary2000.max: ary2000.max
+  ary3000.max: ary3000.max
+  ary5000.max: ary5000.max
+  ary10000.max: ary10000.max
+  ary20000.max: ary20000.max
+  ary50000.max: ary50000.max
+  ary100000.max: ary100000.max
+  ary1000000.max: ary1000000.max
+
+loop_count: 10000
diff --git a/benchmark/array_max_str.yml b/benchmark/array_max_str.yml
new file mode 100644
index 0000000000..2aeed010f2
--- /dev/null
+++ b/benchmark/array_max_str.yml
@@ -0,0 +1,30 @@
+prelude: |
+  ary2 = 2.times.map(&:to_s).shuffle
+  ary10 = 10.times.map(&:to_s).shuffle
+  ary100 = 100.times.map(&:to_s).shuffle
+  ary500 = 500.times.map(&:to_s).shuffle
+  ary1000 = 1000.times.map(&:to_s).shuffle
+  ary2000 = 2500.times.map(&:to_s).shuffle
+  ary3000 = 2500.times.map(&:to_s).shuffle
+  ary5000 = 5000.times.map(&:to_s).shuffle
+  ary10000 = 10000.times.map(&:to_s).shuffle
+  ary20000 = 20000.times.map(&:to_s).shuffle
+  ary50000 = 50000.times.map(&:to_s).shuffle
+  ary100000 = 100000.times.map(&:to_s).shuffle
+
+benchmark:
+  ary2.max: ary2.max
+  ary10.max: ary10.max
+  ary100.max: ary100.max
+  ary500.max: ary500.max
+  ary1000.max: ary1000.max
+  ary2000.max: ary2000.max
+  ary3000.max: ary3000.max
+  ary5000.max: ary5000.max
+  ary10000.max: ary10000.max
+  ary20000.max: ary20000.max
+  ary50000.max: ary50000.max
+  ary100000.max: ary100000.max
+
+loop_count: 10000
+
diff --git a/benchmark/array_min.yml b/benchmark/array_min.yml
new file mode 100644
index 0000000000..53e5072b14
--- /dev/null
+++ b/benchmark/array_min.yml
@@ -0,0 +1,31 @@
+prelude: |
+  ary2 = 2.times.to_a.shuffle
+  ary10 = 10.times.to_a.shuffle
+  ary100 = 100.times.to_a.shuffle
+  ary500 = 500.times.to_a.shuffle
+  ary1000 = 1000.times.to_a.shuffle
+  ary2000 = 2500.times.to_a.shuffle
+  ary3000 = 2500.times.to_a.shuffle
+  ary5000 = 5000.times.to_a.shuffle
+  ary10000 = 10000.times.to_a.shuffle
+  ary20000 = 20000.times.to_a.shuffle
+  ary50000 = 50000.times.to_a.shuffle
+  ary100000 = 100000.times.to_a.shuffle
+  ary1000000 = 1000000.times.to_a.shuffle
+
+benchmark:
+  ary2.min: ary2.min
+  ary10.min: ary10.min
+  ary100.min: ary100.min
+  ary500.min: ary500.min
+  ary1000.min: ary1000.min
+  ary2000.min: ary2000.min
+  ary3000.min: ary3000.min
+  ary5000.min: ary5000.min
+  ary10000.min: ary10000.min
+  ary20000.min: ary20000.min
+  ary50000.min: ary50000.min
+  ary100000.min: ary100000.min
+  ary1000000.min: ary1000000.min
+
+loop_count: 10000
diff --git a/benchmark/array_sample_100k_10.rb b/benchmark/array_sample_100k_10.rb
new file mode 100644
index 0000000000..5f41ecc32b
--- /dev/null
+++ b/benchmark/array_sample_100k_10.rb
@@ -0,0 +1,2 @@
+arr = [*0...100000]
+10_000.times {arr.sample 10}
diff --git a/benchmark/array_sample_100k_11.rb b/benchmark/array_sample_100k_11.rb
new file mode 100644
index 0000000000..18b1715319
--- /dev/null
+++ b/benchmark/array_sample_100k_11.rb
@@ -0,0 +1,2 @@
+arr = [*0...100000]
+10_000.times {arr.sample 11}
diff --git a/benchmark/array_sample_100k__100.rb b/benchmark/array_sample_100k__100.rb
new file mode 100644
index 0000000000..22863afe89
--- /dev/null
+++ b/benchmark/array_sample_100k__100.rb
@@ -0,0 +1,2 @@
+arr = [*0...100000]
+10_000.times {arr.sample 100}
diff --git a/benchmark/array_sample_100k__1k.rb b/benchmark/array_sample_100k__1k.rb
new file mode 100644
index 0000000000..4cd79e6c67
--- /dev/null
+++ b/benchmark/array_sample_100k__1k.rb
@@ -0,0 +1,2 @@
+arr = [*0...100000]
+10_000.times {arr.sample 1000}
diff --git a/benchmark/array_sample_100k__6k.rb b/benchmark/array_sample_100k__6k.rb
new file mode 100644
index 0000000000..b3d264249e
--- /dev/null
+++ b/benchmark/array_sample_100k__6k.rb
@@ -0,0 +1,2 @@
+arr = [*0...100000]
+10_000.times {arr.sample 6000}
diff --git a/benchmark/array_sample_100k___10k.rb b/benchmark/array_sample_100k___10k.rb
new file mode 100644
index 0000000000..5dd55ec058
--- /dev/null
+++ b/benchmark/array_sample_100k___10k.rb
@@ -0,0 +1,2 @@
+arr = [*0...100000]
+10_000.times {arr.sample 10_000}
diff --git a/benchmark/array_sample_100k___50k.rb b/benchmark/array_sample_100k___50k.rb
new file mode 100644
index 0000000000..1506732c3c
--- /dev/null
+++ b/benchmark/array_sample_100k___50k.rb
@@ -0,0 +1,2 @@
+arr = [*0...100000]
+10_000.times {arr.sample 50_000}
diff --git a/benchmark/array_shift.rb b/benchmark/array_shift.rb
new file mode 100644
index 0000000000..798bb9e3f4
--- /dev/null
+++ b/benchmark/array_shift.rb
@@ -0,0 +1,14 @@
+require 'benchmark'
+
+Benchmark.bm do |x|
+  [10_000,1_000_000,100_000_000].each do |n|
+    ary = Array.new(n,0)
+    GC.start
+    x.report("#{n}:shift"){ ary.shift }
+    (0..4).each do |i|
+      ary = Array.new(n,0)
+      GC.start
+      x.report("#{n}:shift(#{i})"){ ary.shift(i) }
+    end
+  end
+end
diff --git a/benchmark/array_small_and.rb b/benchmark/array_small_and.rb
new file mode 100644
index 0000000000..e53a6edae6
--- /dev/null
+++ b/benchmark/array_small_and.rb
@@ -0,0 +1,17 @@
+MIN_SIZE = ENV.fetch('SMALL_ARRAY_MIN', 0).to_i
+MAX_SIZE = ENV.fetch('SMALL_ARRAY_MAX', 16).to_i
+ITERATIONS = ENV.fetch('SMALL_ARRAY_ITERATIONS', 100).to_i
+
+ARRAYS = (MIN_SIZE..MAX_SIZE).map do |size1|
+  (MIN_SIZE..MAX_SIZE).map do |size2|
+    [Array.new(size1) { rand(MAX_SIZE) }, Array.new(size2) { rand(MAX_SIZE) }]
+  end
+end
+
+ITERATIONS.times do
+  ARRAYS.each do |group|
+    group.each do |arr1, arr2|
+      arr1 & arr2
+    end
+  end
+end
diff --git a/benchmark/array_small_diff.rb b/benchmark/array_small_diff.rb
new file mode 100644
index 0000000000..9661ee48db
--- /dev/null
+++ b/benchmark/array_small_diff.rb
@@ -0,0 +1,17 @@
+MIN_SIZE = ENV.fetch('SMALL_ARRAY_MIN', 0).to_i
+MAX_SIZE = ENV.fetch('SMALL_ARRAY_MAX', 16).to_i
+ITERATIONS = ENV.fetch('SMALL_ARRAY_ITERATIONS', 100).to_i
+
+ARRAYS = (MIN_SIZE..MAX_SIZE).map do |size1|
+  (MIN_SIZE..MAX_SIZE).map do |size2|
+    [Array.new(size1) { rand(MAX_SIZE) }, Array.new(size2) { rand(MAX_SIZE) }]
+  end
+end
+
+ITERATIONS.times do
+  ARRAYS.each do |group|
+    group.each do |arr1, arr2|
+      arr1 - arr2
+    end
+  end
+end
diff --git a/benchmark/array_small_or.rb b/benchmark/array_small_or.rb
new file mode 100644
index 0000000000..c58b5fd1ff
--- /dev/null
+++ b/benchmark/array_small_or.rb
@@ -0,0 +1,17 @@
+MIN_SIZE = ENV.fetch('SMALL_ARRAY_MIN', 0).to_i
+MAX_SIZE = ENV.fetch('SMALL_ARRAY_MAX', 16).to_i
+ITERATIONS = ENV.fetch('SMALL_ARRAY_ITERATIONS', 100).to_i
+
+ARRAYS = (MIN_SIZE..MAX_SIZE).map do |size1|
+  (MIN_SIZE..MAX_SIZE).map do |size2|
+    [Array.new(size1) { rand(MAX_SIZE) }, Array.new(size2) { rand(MAX_SIZE) }]
+  end
+end
+
+ITERATIONS.times do
+  ARRAYS.each do |group|
+    group.each do |arr1, arr2|
+      arr1 | arr2
+    end
+  end
+end
diff --git a/benchmark/array_sort_block.rb b/benchmark/array_sort_block.rb
new file mode 100644
index 0000000000..3579786056
--- /dev/null
+++ b/benchmark/array_sort_block.rb
@@ -0,0 +1,2 @@
+ary = Array.new(1000) { rand(1000) }
+10000.times { ary.sort { |a, b| a <=> b } }
diff --git a/benchmark/array_sort_float.rb b/benchmark/array_sort_float.rb
new file mode 100644
index 0000000000..9a6e2f8bd2
--- /dev/null
+++ b/benchmark/array_sort_float.rb
@@ -0,0 +1,2 @@
+arr = Array.new(1000) { rand }
+10000.times { arr.sort }
diff --git a/benchmark/array_values_at_int.rb b/benchmark/array_values_at_int.rb
new file mode 100644
index 0000000000..6cb394cb9f
--- /dev/null
+++ b/benchmark/array_values_at_int.rb
@@ -0,0 +1,2 @@
+ary = Array.new(10000) {|i| i}
+100000.times { ary.values_at(500) }
diff --git a/benchmark/array_values_at_range.rb b/benchmark/array_values_at_range.rb
new file mode 100644
index 0000000000..5b53806d1c
--- /dev/null
+++ b/benchmark/array_values_at_range.rb
@@ -0,0 +1,2 @@
+ary = Array.new(10000) {|i| i}
+100000.times { ary.values_at(1..2000) }
diff --git a/benchmark/bighash.rb b/benchmark/bighash.rb
new file mode 100644
index 0000000000..e2ad5a5c94
--- /dev/null
+++ b/benchmark/bighash.rb
@@ -0,0 +1 @@
+h = {}; 5000000.times {|n| h[n] = n }
diff --git a/benchmark/cgi_escape_html.yml b/benchmark/cgi_escape_html.yml
new file mode 100644
index 0000000000..af6abd08ac
--- /dev/null
+++ b/benchmark/cgi_escape_html.yml
@@ -0,0 +1,40 @@
+prelude: require 'cgi/escape'
+benchmark:
+  - name: escape_html_blank
+    prelude: str = ""
+    script: CGI.escapeHTML(str)
+    loop_count: 20000000
+  - name: escape_html_short_none
+    prelude: str = "abcde"
+    script: CGI.escapeHTML(str)
+    loop_count: 20000000
+  - name: escape_html_short_one
+    prelude: str = "abcd<"
+    script: CGI.escapeHTML(str)
+    loop_count: 20000000
+  - name: escape_html_short_all
+    prelude: str = "'&\"<>"
+    script: CGI.escapeHTML(str)
+    loop_count: 5000000
+  - name: escape_html_long_none
+    prelude: str = "abcde" * 300
+    script: CGI.escapeHTML(str)
+    loop_count: 1000000
+  - name: escape_html_long_all
+    prelude: str = "'&\"<>" * 10
+    script: CGI.escapeHTML(str)
+    loop_count: 1000000
+  - name: escape_html_real
+    prelude: | # http://example.com/
+      str = <<~HTML
+        <body>
+        <div>
+            <h1>Example Domain</h1>
+            <p>This domain is established to be used for illustrative examples in documents. You may use this
+            domain in examples without prior coordination or asking for permission.</p>
+            <p><a href="http://www.iana.org/domains/example">More information...</a></p>
+        </div>
+        </body>
+      HTML
+    script: CGI.escapeHTML(str)
+    loop_count: 1000000
diff --git a/benchmark/complex_float_add.yml b/benchmark/complex_float_add.yml
new file mode 100644
index 0000000000..d0150c5e5b
--- /dev/null
+++ b/benchmark/complex_float_add.yml
@@ -0,0 +1,7 @@
+prelude: |
+  max, min = 1000.0, -1000.0
+  a = Complex(rand(max)+min, rand(max)+min)
+  b = Complex(rand(max)+min, rand(max)+min)
+benchmark:
+  complex_float_add: c = a + b
+loop_count: 1000000
diff --git a/benchmark/complex_float_div.yml b/benchmark/complex_float_div.yml
new file mode 100644
index 0000000000..b9f5e1d51c
--- /dev/null
+++ b/benchmark/complex_float_div.yml
@@ -0,0 +1,7 @@
+prelude: |
+  max, min = 1000.0, -1000.0
+  a = Complex(rand(max)+min, rand(max)+min)
+  b = Complex(rand(max)+min, rand(max)+min)
+benchmark:
+  complex_float_div: c = a / b
+loop_count: 1000000
diff --git a/benchmark/complex_float_mul.yml b/benchmark/complex_float_mul.yml
new file mode 100644
index 0000000000..59b096a6dc
--- /dev/null
+++ b/benchmark/complex_float_mul.yml
@@ -0,0 +1,7 @@
+prelude: |
+  max, min = 1000.0, -1000.0
+  a = Complex(rand(max)+min, rand(max)+min)
+  b = Complex(rand(max)+min, rand(max)+min)
+benchmark:
+  complex_float_mul: c = a * b
+loop_count: 1000000
diff --git a/benchmark/complex_float_new.yml b/benchmark/complex_float_new.yml
new file mode 100644
index 0000000000..6fcde3125b
--- /dev/null
+++ b/benchmark/complex_float_new.yml
@@ -0,0 +1,7 @@
+prelude: |
+  max, min = 1000.0, -1000.0
+  a = Complex(rand(max)+min, rand(max)+min)
+  b = Complex(rand(max)+min, rand(max)+min)
+benchmark:
+  complex_float_new: c = Complex(a, b)
+loop_count: 1000000
diff --git a/benchmark/complex_float_power.yml b/benchmark/complex_float_power.yml
new file mode 100644
index 0000000000..c40a31ab55
--- /dev/null
+++ b/benchmark/complex_float_power.yml
@@ -0,0 +1,7 @@
+prelude: |
+  max, min = 1000.0, -1000.0
+  a = Complex(rand(max)+min, rand(max)+min)
+  b = Complex(rand(max)+min, rand(max)+min)
+benchmark:
+  complex_float_power: c = a ** b
+loop_count: 1000000
diff --git a/benchmark/complex_float_sub.yml b/benchmark/complex_float_sub.yml
new file mode 100644
index 0000000000..3fafe7cdbe
--- /dev/null
+++ b/benchmark/complex_float_sub.yml
@@ -0,0 +1,7 @@
+prelude: |
+  max, min = 1000.0, -1000.0
+  a = Complex(rand(max)+min, rand(max)+min)
+  b = Complex(rand(max)+min, rand(max)+min)
+benchmark:
+  complex_float_sub: c = a - b
+loop_count: 1000000
diff --git a/benchmark/dir_empty_p.rb b/benchmark/dir_empty_p.rb
new file mode 100644
index 0000000000..8329c757cf
--- /dev/null
+++ b/benchmark/dir_empty_p.rb
@@ -0,0 +1,5 @@
+require 'tmpdir'
+max = 100_000
+Dir.mktmpdir('bm_dir_empty_p') do |dir|
+  max.times { Dir.empty?(dir) }
+end
diff --git a/benchmark/enum_lazy_flat_map.yml b/benchmark/enum_lazy_flat_map.yml
new file mode 100644
index 0000000000..0ee390a441
--- /dev/null
+++ b/benchmark/enum_lazy_flat_map.yml
@@ -0,0 +1,16 @@
+prelude: |
+  num = (1..).lazy.take(100)
+  ary2 = [[1,2]].cycle.lazy.take(10)
+  ary10 = [[*1..10]].cycle.lazy.take(10)
+  ary20 = [[*1..20]].cycle.lazy.take(10)
+  ary50 = [[*1..50]].cycle.lazy.take(10)
+  ary100 = [[*1..100]].cycle.lazy.take(10)
+
+benchmark:
+  num3: num.flat_map {|x| x}.take(3).to_a
+  num10: num.flat_map {|x| x}.take(3).to_a
+  ary2:  ary2.flat_map {|x| x}.take(3).to_a
+  ary10: ary10.flat_map {|x| x}.take(3).to_a
+  ary20: ary20.flat_map {|x| x}.take(3).to_a
+  ary50: ary50.flat_map {|x| x}.take(3).to_a
+  ary100: ary100.flat_map {|x| x}.take(3).to_a
diff --git a/benchmark/enum_lazy_grep_v_100.rb b/benchmark/enum_lazy_grep_v_100.rb
new file mode 100644
index 0000000000..8832392e65
--- /dev/null
+++ b/benchmark/enum_lazy_grep_v_100.rb
@@ -0,0 +1,4 @@
+grep_data = (1..10).to_a * 1000
+N = 100
+enum = grep_data.lazy.grep_v(->(i){i == 0}).grep_v(->(i){i == 0})
+N.times {enum.each {}}
diff --git a/benchmark/enum_lazy_grep_v_20.rb b/benchmark/enum_lazy_grep_v_20.rb
new file mode 100644
index 0000000000..329509fa8f
--- /dev/null
+++ b/benchmark/enum_lazy_grep_v_20.rb
@@ -0,0 +1,4 @@
+grep_data = (1..10).to_a * 1000
+N = 100
+enum = grep_data.lazy.grep_v(->(i){i > 2}).grep_v(->(i){i > 2})
+N.times {enum.each {}}
diff --git a/benchmark/enum_lazy_grep_v_50.rb b/benchmark/enum_lazy_grep_v_50.rb
new file mode 100644
index 0000000000..02ea4d4e71
--- /dev/null
+++ b/benchmark/enum_lazy_grep_v_50.rb
@@ -0,0 +1,4 @@
+grep_data = (1..10).to_a * 1000
+N = 100
+enum = grep_data.lazy.grep_v(->(i){i > 5}).grep_v(->(i){i > 5})
+N.times {enum.each {}}
diff --git a/benchmark/enum_lazy_uniq_100.rb b/benchmark/enum_lazy_uniq_100.rb
new file mode 100644
index 0000000000..2e6434d9c4
--- /dev/null
+++ b/benchmark/enum_lazy_uniq_100.rb
@@ -0,0 +1,4 @@
+uniq_data = (1..10_000).to_a
+N = 100
+enum = uniq_data.lazy.uniq {|i| i % 10000}.uniq {|i| i % 10000}
+N.times {enum.each {}}
diff --git a/benchmark/enum_lazy_uniq_20.rb b/benchmark/enum_lazy_uniq_20.rb
new file mode 100644
index 0000000000..75e6398fee
--- /dev/null
+++ b/benchmark/enum_lazy_uniq_20.rb
@@ -0,0 +1,4 @@
+uniq_data = (1..10_000).to_a
+N = 100
+enum = uniq_data.lazy.uniq {|i| i % 2000}.uniq {|i| i % 2000}
+N.times {enum.each {}}
diff --git a/benchmark/enum_lazy_uniq_50.rb b/benchmark/enum_lazy_uniq_50.rb
new file mode 100644
index 0000000000..59a39b78ff
--- /dev/null
+++ b/benchmark/enum_lazy_uniq_50.rb
@@ -0,0 +1,4 @@
+uniq_data = (1..10_000).to_a
+N = 100
+enum = uniq_data.lazy.uniq {|i| i % 5000}.uniq {|i| i % 5000}
+N.times {enum.each {}}
diff --git a/benchmark/enum_lazy_zip.yml b/benchmark/enum_lazy_zip.yml
new file mode 100644
index 0000000000..4566ff0261
--- /dev/null
+++ b/benchmark/enum_lazy_zip.yml
@@ -0,0 +1,22 @@
+prelude: |
+  a = (1..3).lazy
+  b = a.map {|x| x}
+
+benchmark:
+  first_ary: a.zip(["a", "b", "c"]).first
+  first_nonary: a.zip("a".."c").first
+  first_noarg: a.zip.first
+
+  take3_ary: a.zip(["a", "b", "c"]).take(3).force
+  take3_nonary: a.zip("a".."c").take(3).force
+  take3_noarg: a.zip.take(3).force
+
+  chain-first_ary: b.zip(["a", "b", "c"]).first
+  chain-first_nonary: b.zip("a".."c").first
+  chain-first_noarg: b.zip.first
+
+  chain-take3_ary: b.zip(["a", "b", "c"]).take(3).force
+  chain-take3_nonary: b.zip("a".."c").take(3).force
+  chain-take3_noarg: b.zip.take(3).force
+
+  block: a.zip("a".."c") {|x, y| [x, y]}
diff --git a/benchmark/erb_render.yml b/benchmark/erb_render.yml
new file mode 100644
index 0000000000..15f6c3880b
--- /dev/null
+++ b/benchmark/erb_render.yml
@@ -0,0 +1,24 @@
+prelude: |
+  require 'erb'
+
+  data = <<erb
+  <html>
+    <head> <%= title %> </head>
+    <body>
+      <h1> <%= title %> </h1>
+      <p>
+        <%= content %>
+      </p>
+    </body>
+  </html>
+  erb
+
+  title = "hello world!"
+  content = "hello world!\n" * 10
+
+  src = "def self.render(title, content); #{ERB.new(data).src}; end"
+  mod = Module.new
+  mod.instance_eval(src, "(ERB)")
+benchmark:
+  erb_render: mod.render(title, content)
+loop_count: 1500000
diff --git a/benchmark/fiber_chain.yml b/benchmark/fiber_chain.yml
new file mode 100644
index 0000000000..a36c759f8e
--- /dev/null
+++ b/benchmark/fiber_chain.yml
@@ -0,0 +1,36 @@
+prelude: |
+  def make_link(previous)
+    Fiber.new do
+      while message = previous.resume
+        Fiber.yield(message)
+      end
+    end
+  end
+
+  def make_chain(length = 1000, &block)
+    chain = Fiber.new(&block)
+
+    (length - 1).times do
+      chain = make_link(chain)
+    end
+
+    return chain
+  end
+
+  message = "Hello World!"
+
+  chain = make_chain do
+    while true
+      Fiber.yield(message)
+    end
+  end
+benchmark:
+  make_chain: |
+    make_chain(100) do
+      while true
+        Fiber.yield(message)
+      end
+    end
+  resume_chain: |
+    chain.resume
+loop_count: 5000
diff --git a/benchmark/fiber_locals.yml b/benchmark/fiber_locals.yml
new file mode 100644
index 0000000000..8588686477
--- /dev/null
+++ b/benchmark/fiber_locals.yml
@@ -0,0 +1,8 @@
+prelude: |
+  th = Thread.current
+  th[:key] = :val
+benchmark:
+  key?: th.key?(:key)
+  []: th[:key]
+  keys: th.keys
+loop_count: 1_000_000
diff --git a/benchmark/file_chmod.rb b/benchmark/file_chmod.rb
new file mode 100644
index 0000000000..1cd4760c9d
--- /dev/null
+++ b/benchmark/file_chmod.rb
@@ -0,0 +1,9 @@
+# chmod file
+require 'tempfile'
+max = 200_000
+tmp = Tempfile.new('chmod')
+path = tmp.path
+max.times do
+  File.chmod(0777, path)
+end
+tmp.close!
diff --git a/benchmark/file_rename.rb b/benchmark/file_rename.rb
new file mode 100644
index 0000000000..bbb44aebac
--- /dev/null
+++ b/benchmark/file_rename.rb
@@ -0,0 +1,11 @@
+# rename file
+require 'tempfile'
+
+max = 100_000
+tmp = [ Tempfile.new('rename-a'), Tempfile.new('rename-b') ]
+a, b = tmp.map { |x| x.path }
+tmp.each { |t| t.close } # Windows can't rename files without closing them
+max.times do
+  File.rename(a, b)
+  File.rename(b, a)
+end
diff --git a/benchmark/gc/aobench.rb b/benchmark/gc/aobench.rb
new file mode 100644
index 0000000000..275f58b924
--- /dev/null
+++ b/benchmark/gc/aobench.rb
@@ -0,0 +1 @@
+require_relative '../app_aobench'
diff --git a/benchmark/gc/binary_trees.rb b/benchmark/gc/binary_trees.rb
new file mode 100644
index 0000000000..83347cdd20
--- /dev/null
+++ b/benchmark/gc/binary_trees.rb
@@ -0,0 +1 @@
+require_relative '../so_binary_trees'
diff --git a/benchmark/gc/gcbench.rb b/benchmark/gc/gcbench.rb
new file mode 100644
index 0000000000..23d0b91c6c
--- /dev/null
+++ b/benchmark/gc/gcbench.rb
@@ -0,0 +1,57 @@
+require 'benchmark'
+require 'pp'
+require 'optparse'
+
+$list = true
+$gcprof = false
+
+opt = OptionParser.new
+opt.on('-q'){$list = false}
+opt.on('-d'){$gcprof = false}
+opt.on('-p'){$gcprof = true}
+opt.parse!(ARGV)
+
+script = File.join(File.dirname(__FILE__), ARGV.shift)
+script += '.rb' unless FileTest.exist?(script)
+raise "#{script} not found" unless FileTest.exist?(script)
+
+puts "Script: #{script}"
+
+if $gcprof
+  GC::Profiler.enable
+end
+
+tms = Benchmark.measure{|x|
+  load script
+}
+
+gc_time = 0
+
+if $gcprof
+  gc_time = GC::Profiler.total_time
+  GC::Profiler.report if $list and RUBY_VERSION >= '2.0.0' # before 1.9.3, report() may run infinite loop
+  GC::Profiler.disable
+end
+
+pp GC.stat
+
+puts "#{RUBY_DESCRIPTION} #{GC::OPTS.inspect}" if defined?(GC::OPTS)
+
+desc = "#{RUBY_VERSION}#{RUBY_PATCHLEVEL >= 0 ? "p#{RUBY_PATCHLEVEL}" : "dev"}"
+name = File.basename(script, '.rb')
+
+puts
+puts script
+puts Benchmark::CAPTION
+puts tms
+puts "GC total time (sec): #{gc_time}"
+
+# show High-Water Mark on Linux
+if File.exist?('/proc/self/status') && /VmHWM:\s*(\d+.+)/ =~ File.read('/proc/self/status')
+  puts
+  puts "VmHWM: #{$1.chomp}"
+end
+
+puts
+puts "Summary of #{name} on #{desc}\t#{tms.real}\t#{gc_time}\t#{GC.count}"
+puts "         (real time in sec, GC time in sec, GC count)"
diff --git a/benchmark/gc/hash1.rb b/benchmark/gc/hash1.rb
new file mode 100644
index 0000000000..cb030d458d
--- /dev/null
+++ b/benchmark/gc/hash1.rb
@@ -0,0 +1,11 @@
+value = 0.01
+h = {}
+n = 50_000
+
+1.upto(n){|i|
+  h["%020d" % i] = "v-#{i}"
+}
+
+(n * 1_000).times{
+  ''
+}
diff --git a/benchmark/gc/hash2.rb b/benchmark/gc/hash2.rb
new file mode 100644
index 0000000000..e8c943fb21
--- /dev/null
+++ b/benchmark/gc/hash2.rb
@@ -0,0 +1,7 @@
+value = 0.01
+h = {}
+n = 4*(10**6)
+
+1.upto(n){|i|
+  h["%020d" % i] = value * i
+}
diff --git a/benchmark/gc/null.rb b/benchmark/gc/null.rb
new file mode 100644
index 0000000000..c05a79f561
--- /dev/null
+++ b/benchmark/gc/null.rb
@@ -0,0 +1 @@
+# null
diff --git a/benchmark/gc/pentomino.rb b/benchmark/gc/pentomino.rb
new file mode 100644
index 0000000000..8ebdff7d1d
--- /dev/null
+++ b/benchmark/gc/pentomino.rb
@@ -0,0 +1 @@
+require_relative '../app_pentomino'
diff --git a/benchmark/gc/rdoc.rb b/benchmark/gc/rdoc.rb
new file mode 100644
index 0000000000..14c89f5611
--- /dev/null
+++ b/benchmark/gc/rdoc.rb
@@ -0,0 +1,13 @@
+require 'rdoc/rdoc'
+require 'tmpdir'
+
+srcdir = File.expand_path('../..', __dir__)
+
+Dir.mktmpdir('rdocbench-'){|d|
+  dir = File.join(d, 'rdocbench')
+  args = %W(--root #{srcdir} --page-dir #{srcdir}/doc --encoding=UTF-8 --no-force-update --all --ri --debug --quiet #{srcdir})
+  args << '--op' << dir
+
+  r = RDoc::RDoc.new
+  r.document args
+}
diff --git a/benchmark/gc/redblack.rb b/benchmark/gc/redblack.rb
new file mode 100644
index 0000000000..c66290140a
--- /dev/null
+++ b/benchmark/gc/redblack.rb
@@ -0,0 +1,366 @@
+# This benchmark is imported from https://github.com/jruby/rubybench/blob/master/time/bench_red_black.rb
+# License is License is Apache-2
+
+require 'benchmark'
+
+# Algorithm based on "Introduction to Algorithms" by Cormen and others
+class RedBlackTree
+  class Node
+    attr_accessor :color
+    attr_accessor :key
+    attr_accessor :left
+    attr_accessor :right
+    attr_accessor :parent
+
+    RED = :red
+    BLACK = :black
+    COLORS = [RED, BLACK].freeze
+
+    def initialize(key, color = RED)
+      raise ArgumentError, "Bad value for color parameter" unless COLORS.include?(color)
+      @color = color
+      @key = key
+      @left = @right = @parent = NilNode.instance
+    end
+
+    def black?
+      return color == BLACK
+    end
+
+    def red?
+      return color == RED
+    end
+  end
+
+  class NilNode < Node
+    class << self
+      private :new
+
+      # it's not thread safe
+      def instance
+        @instance ||= begin
+          def instance
+            return @instance
+          end
+
+          new
+        end
+      end
+    end
+
+    def initialize
+      self.color = BLACK
+      self.key = 0
+      self.left = nil
+      self.right = nil
+      self.parent = nil
+    end
+
+    def nil?
+      return true
+    end
+  end
+
+  include Enumerable
+
+  attr_accessor :root
+  attr_accessor :size
+
+  def initialize
+    self.root = NilNode.instance
+    self.size = 0
+  end
+
+  def add(key)
+    insert(Node.new(key))
+  end
+
+  def insert(x)
+    insert_helper(x)
+
+    x.color = Node::RED
+    while x != root && x.parent.color == Node::RED
+      if x.parent == x.parent.parent.left
+        y = x.parent.parent.right
+        if !y.nil? && y.color == Node::RED
+          x.parent.color = Node::BLACK
+          y.color = Node::BLACK
+          x.parent.parent.color = Node::RED
+          x = x.parent.parent
+        else
+          if x == x.parent.right
+            x = x.parent
+            left_rotate(x)
+          end
+          x.parent.color = Node::BLACK
+          x.parent.parent.color = Node::RED
+          right_rotate(x.parent.parent)
+        end
+      else
+        y = x.parent.parent.left
+        if !y.nil? && y.color == Node::RED
+          x.parent.color = Node::BLACK
+          y.color = Node::BLACK
+          x.parent.parent.color = Node::RED
+          x = x.parent.parent
+        else
+          if x == x.parent.left
+            x = x.parent
+            right_rotate(x)
+          end
+          x.parent.color = Node::BLACK
+          x.parent.parent.color = Node::RED
+          left_rotate(x.parent.parent)
+        end
+      end
+    end
+    root.color = Node::BLACK
+  end
+
+  alias << insert
+
+  def delete(z)
+    y = (z.left.nil? || z.right.nil?) ? z : successor(z)
+    x = y.left.nil? ? y.right : y.left
+    x.parent = y.parent
+
+    if y.parent.nil?
+      self.root = x
+    else
+      if y == y.parent.left
+        y.parent.left = x
+      else
+        y.parent.right = x
+      end
+    end
+
+    z.key = y.key if y != z
+
+    if y.color == Node::BLACK
+      delete_fixup(x)
+    end
+
+    self.size -= 1
+    return y
+  end
+
+  def minimum(x = root)
+    while !x.left.nil?
+      x = x.left
+    end
+    return x
+  end
+
+  def maximum(x = root)
+    while !x.right.nil?
+      x = x.right
+    end
+    return x
+  end
+
+  def successor(x)
+    if !x.right.nil?
+      return minimum(x.right)
+    end
+    y = x.parent
+    while !y.nil? && x == y.right
+      x = y
+      y = y.parent
+    end
+    return y
+  end
+
+  def predecessor(x)
+    if !x.left.nil?
+      return maximum(x.left)
+    end
+    y = x.parent
+    while !y.nil? && x == y.left
+      x = y
+      y = y.parent
+    end
+    return y
+  end
+
+  def inorder_walk(x = root)
+    x = self.minimum
+    while !x.nil?
+      yield x.key
+      x = successor(x)
+    end
+  end
+
+  alias each inorder_walk
+
+  def reverse_inorder_walk(x = root)
+    x = self.maximum
+    while !x.nil?
+      yield x.key
+      x = predecessor(x)
+    end
+  end
+
+  alias reverse_each reverse_inorder_walk
+
+  def search(key, x = root)
+    while !x.nil? && x.key != key
+      key < x.key ? x = x.left : x = x.right
+    end
+    return x
+  end
+
+  def empty?
+    return self.root.nil?
+  end
+
+  def black_height(x = root)
+    height = 0
+    while !x.nil?
+      x = x.left
+      height +=1 if x.nil? || x.black?
+    end
+    return height
+  end
+
+private
+
+  def left_rotate(x)
+    raise "x.right is nil!" if x.right.nil?
+    y = x.right
+    x.right = y.left
+    y.left.parent = x if !y.left.nil?
+    y.parent = x.parent
+    if x.parent.nil?
+      self.root = y
+    else
+      if x == x.parent.left
+        x.parent.left = y
+      else
+        x.parent.right = y
+      end
+    end
+    y.left = x
+    x.parent = y
+  end
+
+  def right_rotate(x)
+    raise "x.left is nil!" if x.left.nil?
+    y = x.left
+    x.left = y.right
+    y.right.parent = x if !y.right.nil?
+    y.parent = x.parent
+    if x.parent.nil?
+      self.root = y
+    else
+      if x == x.parent.left
+        x.parent.left = y
+      else
+        x.parent.right = y
+      end
+    end
+    y.right = x
+    x.parent = y
+  end
+
+  def insert_helper(z)
+    y = NilNode.instance
+    x = root
+    while !x.nil?
+      y = x
+      z.key < x.key ? x = x.left : x = x.right
+    end
+    z.parent = y
+    if y.nil?
+      self.root = z
+    else
+      z.key < y.key ? y.left = z : y.right = z
+    end
+    self.size += 1
+  end
+
+  def delete_fixup(x)
+    while x != root && x.color == Node::BLACK
+      if x == x.parent.left
+        w = x.parent.right
+        if w.color == Node::RED
+          w.color = Node::BLACK
+          x.parent.color = Node::RED
+          left_rotate(x.parent)
+          w = x.parent.right
+        end
+        if w.left.color == Node::BLACK && w.right.color == Node::BLACK
+          w.color = Node::RED
+          x = x.parent
+        else
+          if w.right.color == Node::BLACK
+            w.left.color = Node::BLACK
+            w.color = Node::RED
+            right_rotate(w)
+            w = x.parent.right
+          end
+          w.color = x.parent.color
+          x.parent.color = Node::BLACK
+          w.right.color = Node::BLACK
+          left_rotate(x.parent)
+          x = root
+        end
+      else
+        w = x.parent.left
+        if w.color == Node::RED
+          w.color = Node::BLACK
+          x.parent.color = Node::RED
+          right_rotate(x.parent)
+          w = x.parent.left
+        end
+        if w.right.color == Node::BLACK && w.left.color == Node::BLACK
+          w.color = Node::RED
+          x = x.parent
+        else
+          if w.left.color == Node::BLACK
+            w.right.color = Node::BLACK
+            w.color = Node::RED
+            left_rotate(w)
+            w = x.parent.left
+          end
+          w.color = x.parent.color
+          x.parent.color = Node::BLACK
+          w.left.color = Node::BLACK
+          right_rotate(x.parent)
+          x = root
+        end
+      end
+    end
+    x.color = Node::BLACK
+  end
+end
+
+def rbt_bm
+  n = 100_000
+  a1 = []; n.times { a1 << rand(999_999) }
+  a2 = []; n.times { a2 << rand(999_999) }
+
+  start = Time.now
+
+  tree = RedBlackTree.new
+
+  n.times {|i| tree.add(i) }
+  n.times { tree.delete(tree.root) }
+
+  tree = RedBlackTree.new
+  a1.each {|e| tree.add(e) }
+  a2.each {|e| tree.search(e) }
+  tree.inorder_walk {|key| key + 1 }
+  tree.reverse_inorder_walk {|key| key + 1 }
+  n.times { tree.minimum }
+  n.times { tree.maximum }
+
+  return Time.now - start
+end
+
+N = (ARGV[0] || 10).to_i
+
+N.times do
+  # puts rbt_bm.to_f
+  rbt_bm.to_f
+  # puts "GC.count = #{GC.count}" if GC.respond_to?(:count)
+end
diff --git a/benchmark/gc/ring.rb b/benchmark/gc/ring.rb
new file mode 100644
index 0000000000..be2c7b7250
--- /dev/null
+++ b/benchmark/gc/ring.rb
@@ -0,0 +1,29 @@
+# create many old objects
+
+max = 30_000_000
+
+class Ring
+  attr_reader :next_ring
+  def initialize n = nil
+    @next_ring = n
+  end
+
+
+  def size
+    s = 1
+    ring = self
+    while ring.next_ring
+      s += 1
+      ring = ring.next_ring
+    end
+    s
+  end
+end
+
+ring = Ring.new
+
+max.times{
+  ring = Ring.new(ring)
+}
+
+# p ring.size
diff --git a/benchmark/hash_aref_dsym.rb b/benchmark/hash_aref_dsym.rb
new file mode 100644
index 0000000000..af4f8c36d4
--- /dev/null
+++ b/benchmark/hash_aref_dsym.rb
@@ -0,0 +1,4 @@
+h = {}
+syms = ('a'..'z').map { |s| s.to_sym }
+syms.each { |s| h[s] = 1 }
+200_000.times { syms.each { |s| h[s] } }
diff --git a/benchmark/hash_aref_dsym_long.rb b/benchmark/hash_aref_dsym_long.rb
new file mode 100644
index 0000000000..9d7759379e
--- /dev/null
+++ b/benchmark/hash_aref_dsym_long.rb
@@ -0,0 +1,21 @@
+# [ruby-core:70129] [Bug #11396]
+collection_size = 200000
+sample_size = 10000
+
+values = (1..collection_size).to_a.map do |x|
+  "THIS IS A LONGER STRING THAT IS ALSO UNIQUE #{x}"
+end
+
+symbol_hash = {}
+
+values.each do |x|
+  symbol_hash[x.to_sym] = 1
+end
+
+# use the same samples each time to minimize deviations
+rng = Random.new(0)
+symbol_sample_array = values.sample(sample_size, random: rng).map(&:to_sym)
+
+3000.times do
+  symbol_sample_array.each { |x| symbol_hash[x] }
+end
diff --git a/benchmark/hash_aref_fix.rb b/benchmark/hash_aref_fix.rb
new file mode 100644
index 0000000000..1346890582
--- /dev/null
+++ b/benchmark/hash_aref_fix.rb
@@ -0,0 +1,4 @@
+h = {}
+nums = (1..26).to_a
+nums.each { |i| h[i] = i }
+200_000.times { nums.each { |s| h[s] } }
diff --git a/benchmark/hash_aref_flo.rb b/benchmark/hash_aref_flo.rb
new file mode 100644
index 0000000000..2217274c82
--- /dev/null
+++ b/benchmark/hash_aref_flo.rb
@@ -0,0 +1,4 @@
+h = {}
+strs = [*1..10000].map! {|i| i.fdiv(10)}
+strs.each { |s| h[s] = s }
+50.times { strs.each { |s| h[s] } }
diff --git a/benchmark/hash_aref_miss.rb b/benchmark/hash_aref_miss.rb
new file mode 100644
index 0000000000..b0913dd4bb
--- /dev/null
+++ b/benchmark/hash_aref_miss.rb
@@ -0,0 +1,5 @@
+h = {}
+strs = ('a'..'z').to_a.map!(&:freeze)
+strs.each { |s| h[s] = s }
+strs = ('A'..'Z').to_a
+200_000.times { strs.each { |s| h[s] } }
diff --git a/benchmark/hash_aref_str.rb b/benchmark/hash_aref_str.rb
new file mode 100644
index 0000000000..19439b061b
--- /dev/null
+++ b/benchmark/hash_aref_str.rb
@@ -0,0 +1,4 @@
+h = {}
+strs = ('a'..'z').to_a.map!(&:freeze)
+strs.each { |s| h[s] = s }
+200_000.times { strs.each { |s| h[s] } }
diff --git a/benchmark/hash_aref_sym.rb b/benchmark/hash_aref_sym.rb
new file mode 100644
index 0000000000..f75d163fe6
--- /dev/null
+++ b/benchmark/hash_aref_sym.rb
@@ -0,0 +1,9 @@
+h = {}
+syms = ('a'..'z').to_a
+begin
+  syms = eval("%i[#{syms.join(' ')}]")
+rescue SyntaxError # <= 1.9.3
+  syms.map!(&:to_sym)
+end
+syms.each { |s| h[s] = s }
+200_000.times { syms.each { |s| h[s] } }
diff --git a/benchmark/hash_aref_sym_long.rb b/benchmark/hash_aref_sym_long.rb
new file mode 100644
index 0000000000..9dab8df7be
--- /dev/null
+++ b/benchmark/hash_aref_sym_long.rb
@@ -0,0 +1,13 @@
+h = {}
+syms = %w[puts warn syswrite write stat bacon lettuce tomato
+some symbols in this array may already be interned  others should not be
+hash browns make good breakfast but not cooked using prime numbers
+shift for division entries delete_if keys exist?
+]
+begin
+  syms = eval("%i[#{syms.join(' ')}]")
+rescue SyntaxError # <= 1.9.3
+  syms.map!(&:to_sym)
+end
+syms.each { |s| h[s] = s }
+200_000.times { syms.each { |s| h[s] } }
diff --git a/benchmark/hash_defaults.yml b/benchmark/hash_defaults.yml
new file mode 100644
index 0000000000..833f10e1c7
--- /dev/null
+++ b/benchmark/hash_defaults.yml
@@ -0,0 +1,6 @@
+prelude: |
+  h = Hash.new { :foo }
+benchmark:
+  default_aref: h[1]
+  default_method: h.default(1)
+loop_count: 1000000
diff --git a/benchmark/hash_dup.yml b/benchmark/hash_dup.yml
new file mode 100644
index 0000000000..65f521ec94
--- /dev/null
+++ b/benchmark/hash_dup.yml
@@ -0,0 +1,8 @@
+prelude: |
+  small_hash = { a: 1 }
+  larger_hash = 20.times.map { |i| [('a'.ord + i).chr.to_sym, i] }.to_h
+
+benchmark:
+  dup_small: small_hash.dup
+  dup_larger: larger_hash.dup
+loop_count: 10000
diff --git a/benchmark/hash_flatten.rb b/benchmark/hash_flatten.rb
new file mode 100644
index 0000000000..e944aae9f2
--- /dev/null
+++ b/benchmark/hash_flatten.rb
@@ -0,0 +1,9 @@
+h = {}
+
+10000.times do |i|
+  h[i] = nil
+end
+
+1000.times do
+  h.flatten
+end
diff --git a/benchmark/hash_ident_flo.rb b/benchmark/hash_ident_flo.rb
new file mode 100644
index 0000000000..0c7edfed3e
--- /dev/null
+++ b/benchmark/hash_ident_flo.rb
@@ -0,0 +1,4 @@
+h = {}.compare_by_identity
+strs = (1..10000).to_a.map!(&:to_f)
+strs.each { |s| h[s] = s }
+50.times { strs.each { |s| h[s] } }
diff --git a/benchmark/hash_ident_num.rb b/benchmark/hash_ident_num.rb
new file mode 100644
index 0000000000..b226736c6f
--- /dev/null
+++ b/benchmark/hash_ident_num.rb
@@ -0,0 +1,4 @@
+h = {}.compare_by_identity
+nums = (1..26).to_a
+nums.each { |n| h[n] = n }
+200_000.times { nums.each { |n| h[n] } }
diff --git a/benchmark/hash_ident_obj.rb b/benchmark/hash_ident_obj.rb
new file mode 100644
index 0000000000..4b3b58edec
--- /dev/null
+++ b/benchmark/hash_ident_obj.rb
@@ -0,0 +1,4 @@
+h = {}.compare_by_identity
+objs = 26.times.map { Object.new }
+objs.each { |o| h[o] = o }
+200_000.times { objs.each { |o| h[o] } }
diff --git a/benchmark/hash_ident_str.rb b/benchmark/hash_ident_str.rb
new file mode 100644
index 0000000000..8582b38e31
--- /dev/null
+++ b/benchmark/hash_ident_str.rb
@@ -0,0 +1,4 @@
+h = {}.compare_by_identity
+strs = ('a'..'z').to_a
+strs.each { |s| h[s] = s }
+200_000.times { strs.each { |s| h[s] } }
diff --git a/benchmark/hash_ident_sym.rb b/benchmark/hash_ident_sym.rb
new file mode 100644
index 0000000000..4c81e3d28e
--- /dev/null
+++ b/benchmark/hash_ident_sym.rb
@@ -0,0 +1,4 @@
+h = {}.compare_by_identity
+syms = ('a'..'z').to_a.map(&:to_sym)
+syms.each { |s| h[s] = s }
+200_000.times { syms.each { |s| h[s] } }
diff --git a/benchmark/hash_keys.rb b/benchmark/hash_keys.rb
new file mode 100644
index 0000000000..6863cd01f9
--- /dev/null
+++ b/benchmark/hash_keys.rb
@@ -0,0 +1,9 @@
+h = {}
+
+10000.times do |i|
+  h[i] = nil
+end
+
+5000.times do
+  h.keys
+end
diff --git a/benchmark/hash_literal_small2.rb b/benchmark/hash_literal_small2.rb
new file mode 100644
index 0000000000..c188529260
--- /dev/null
+++ b/benchmark/hash_literal_small2.rb
@@ -0,0 +1,3 @@
+# frozen_string_literal: true
+
+1_000_000.times.map { { "foo" => "bar", "bar" => "baz" }  }
diff --git a/benchmark/hash_literal_small4.rb b/benchmark/hash_literal_small4.rb
new file mode 100644
index 0000000000..739f71b5b0
--- /dev/null
+++ b/benchmark/hash_literal_small4.rb
@@ -0,0 +1,3 @@
+# frozen_string_literal: true
+
+1_000_000.times.map { { "foo" => "bar", "bar" => "baz", "baz" => "lol", "lol" => "lgtm" } }
diff --git a/benchmark/hash_literal_small8.rb b/benchmark/hash_literal_small8.rb
new file mode 100644
index 0000000000..53d80af535
--- /dev/null
+++ b/benchmark/hash_literal_small8.rb
@@ -0,0 +1,3 @@
+# frozen_string_literal: true
+
+1_000_000.times.map { { "foo" => "bar", "bar" => "baz", "baz" => "lol", "lol" => "lgtm", "lgtm" => "nope", "nope" => "ok", "ok" => "again", "again" => "wait" } }
diff --git a/benchmark/hash_long.rb b/benchmark/hash_long.rb
new file mode 100644
index 0000000000..03d9109602
--- /dev/null
+++ b/benchmark/hash_long.rb
@@ -0,0 +1,4 @@
+k1 = "Ping Pong Ping Pong Ping Pong Ping Pong Ping Pong Ping Pong Ping Pong Ping Pong Ping Pong Ping Pong";
+k2 = "Pong Ping Pong Ping Pong Ping Pong Ping Pong Ping Pong Ping Pong Ping Pong Ping Pong Ping Pong Ping";
+h = {k1 => 0, k2 => 0};
+3000000.times{|i| k = i % 2 ? k2 : k1; h [k] = h[k] + 1}
diff --git a/benchmark/hash_shift.rb b/benchmark/hash_shift.rb
new file mode 100644
index 0000000000..a645671a5b
--- /dev/null
+++ b/benchmark/hash_shift.rb
@@ -0,0 +1,10 @@
+h = {}
+
+10000.times do |i|
+  h[i] = nil
+end
+
+50000.times do
+  k, v = h.shift
+  h[k] = v
+end
diff --git a/benchmark/hash_shift_u16.rb b/benchmark/hash_shift_u16.rb
new file mode 100644
index 0000000000..ec800d0342
--- /dev/null
+++ b/benchmark/hash_shift_u16.rb
@@ -0,0 +1,10 @@
+h = {}
+
+(16384..65536).each do |i|
+  h[i] = nil
+end
+
+300000.times do
+  k, v = h.shift
+  h[k] = v
+end
diff --git a/benchmark/hash_shift_u24.rb b/benchmark/hash_shift_u24.rb
new file mode 100644
index 0000000000..de4e0fa696
--- /dev/null
+++ b/benchmark/hash_shift_u24.rb
@@ -0,0 +1,10 @@
+h = {}
+
+(0xff4000..0xffffff).each do |i|
+  h[i] = nil
+end
+
+300000.times do
+  k, v = h.shift
+  h[k] = v
+end
diff --git a/benchmark/hash_shift_u32.rb b/benchmark/hash_shift_u32.rb
new file mode 100644
index 0000000000..656aa55583
--- /dev/null
+++ b/benchmark/hash_shift_u32.rb
@@ -0,0 +1,10 @@
+h = {}
+
+(0xffff4000..0xffffffff).each do |i|
+  h[i] = nil
+end
+
+300000.times do
+  k, v = h.shift
+  h[k] = v
+end
diff --git a/benchmark/hash_small2.rb b/benchmark/hash_small2.rb
new file mode 100644
index 0000000000..45485d9c71
--- /dev/null
+++ b/benchmark/hash_small2.rb
@@ -0,0 +1 @@
+1000000.times.map{|i| a={}; 2.times{|j| a[j]=j}; a}
diff --git a/benchmark/hash_small4.rb b/benchmark/hash_small4.rb
new file mode 100644
index 0000000000..acd4084334
--- /dev/null
+++ b/benchmark/hash_small4.rb
@@ -0,0 +1 @@
+1000000.times.map{|i| a={}; 4.times{|j| a[j]=j}; a}
diff --git a/benchmark/hash_small8.rb b/benchmark/hash_small8.rb
new file mode 100644
index 0000000000..9cffcc91b6
--- /dev/null
+++ b/benchmark/hash_small8.rb
@@ -0,0 +1 @@
+1000000.times.map{|i| a={}; 8.times{|j| a[j]=j}; a}
diff --git a/benchmark/hash_to_proc.rb b/benchmark/hash_to_proc.rb
new file mode 100644
index 0000000000..2b675bf509
--- /dev/null
+++ b/benchmark/hash_to_proc.rb
@@ -0,0 +1,9 @@
+h = {}
+
+10000.times do |i|
+  h[i] = nil
+end
+
+5000.times do |i|
+  [i].map(&h)
+end
diff --git a/benchmark/hash_values.rb b/benchmark/hash_values.rb
new file mode 100644
index 0000000000..069441302f
--- /dev/null
+++ b/benchmark/hash_values.rb
@@ -0,0 +1,9 @@
+h = {}
+
+10000.times do |i|
+  h[i] = nil
+end
+
+5000.times do
+  h.values
+end
diff --git a/benchmark/int_quo.rb b/benchmark/int_quo.rb
new file mode 100644
index 0000000000..e22a3f8c30
--- /dev/null
+++ b/benchmark/int_quo.rb
@@ -0,0 +1 @@
+5000000.times { 42.quo(3) }
diff --git a/benchmark/io_copy_stream_write.rb b/benchmark/io_copy_stream_write.rb
new file mode 100644
index 0000000000..3fd87250a4
--- /dev/null
+++ b/benchmark/io_copy_stream_write.rb
@@ -0,0 +1,24 @@
+# The goal of this is to use a synthetic (non-IO) reader
+# to trigger the read/write loop of IO.copy_stream,
+# bypassing in-kernel mechanisms like sendfile for zero copy,
+# so we wrap the /dev/zero IO object:
+
+class Zero
+  def initialize
+    @n = 100000
+    @in = File.open('/dev/zero', 'rb')
+  end
+
+  def read(len, buf)
+    return if (@n -= 1) == 0
+    @in.read(len, buf)
+  end
+end
+
+begin
+  src = Zero.new
+  dst = File.open(IO::NULL, 'wb')
+  n = IO.copy_stream(src, dst)
+rescue Errno::ENOENT
+  # not *nix
+end if IO.respond_to?(:copy_stream) && IO.const_defined?(:NULL)
diff --git a/benchmark/io_copy_stream_write_socket.rb b/benchmark/io_copy_stream_write_socket.rb
new file mode 100644
index 0000000000..11f369bd0d
--- /dev/null
+++ b/benchmark/io_copy_stream_write_socket.rb
@@ -0,0 +1,35 @@
+# The goal of this is to use a synthetic (non-IO) reader
+# to trigger the read/write loop of IO.copy_stream,
+# bypassing in-kernel mechanisms like sendfile for zero copy,
+# so we wrap the /dev/zero IO object:
+class Zero
+  def initialize
+    @n = 100000
+    @in = File.open('/dev/zero', 'rb')
+  end
+
+  def read(len, buf)
+    return if (@n -= 1) == 0
+    @in.read(len, buf)
+  end
+end
+
+begin
+  require 'socket'
+  src = Zero.new
+  rd, wr = UNIXSocket.pair
+  pid = fork do
+    wr.close
+    buf = String.new
+    while rd.read(16384, buf)
+    end
+  end
+  rd.close
+  IO.copy_stream(src, wr)
+rescue Errno::ENOENT, NotImplementedError, NameError
+  # not *nix: missing /dev/zero, fork, or UNIXSocket
+rescue LoadError # no socket?
+ensure
+  wr.close if wr
+  Process.waitpid(pid) if pid
+end if IO.respond_to?(:copy_stream)
diff --git a/benchmark/io_file_create.rb b/benchmark/io_file_create.rb
new file mode 100644
index 0000000000..2f205c1333
--- /dev/null
+++ b/benchmark/io_file_create.rb
@@ -0,0 +1,13 @@
+#
+# Create files
+#
+
+max = 200_000
+file = './tmpfile_of_bm_io_file_create'
+
+max.times{
+  f = open(file, 'w')
+  f.close#(true)
+}
+File.unlink(file)
+
diff --git a/benchmark/io_file_read.rb b/benchmark/io_file_read.rb
new file mode 100644
index 0000000000..b9e796ed30
--- /dev/null
+++ b/benchmark/io_file_read.rb
@@ -0,0 +1,15 @@
+#
+# Seek and Read file.
+#
+
+require 'tempfile'
+
+max = 200_000
+str = "Hello world!  " * 1000
+f = Tempfile.new('yarv-benchmark')
+f.write str
+
+max.times{
+  f.seek 0
+  f.read
+}
diff --git a/benchmark/io_file_write.rb b/benchmark/io_file_write.rb
new file mode 100644
index 0000000000..aa1be0e5fe
--- /dev/null
+++ b/benchmark/io_file_write.rb
@@ -0,0 +1,14 @@
+#
+# Seek and Write file.
+#
+
+require 'tempfile'
+
+max = 200_000
+str = "Hello world!  " * 1000
+f = Tempfile.new('yarv-benchmark')
+
+max.times{
+  f.seek 0
+  f.write str
+}
diff --git a/benchmark/io_nonblock_noex.rb b/benchmark/io_nonblock_noex.rb
new file mode 100644
index 0000000000..da9357fdc6
--- /dev/null
+++ b/benchmark/io_nonblock_noex.rb
@@ -0,0 +1,22 @@
+nr = 1_000_000
+i = 0
+msg = '.'
+buf = '.'
+noex = { exception: false }
+begin
+  r, w = IO.pipe
+  while i < nr
+    i += 1
+    w.write_nonblock(msg, noex)
+    r.read_nonblock(1, buf, noex)
+  end
+rescue ArgumentError # old Rubies
+  while i < nr
+    i += 1
+    w.write_nonblock(msg)
+    r.read_nonblock(1, buf)
+  end
+ensure
+  r.close
+  w.close
+end
diff --git a/benchmark/io_nonblock_noex2.rb b/benchmark/io_nonblock_noex2.rb
new file mode 100644
index 0000000000..56819d049b
--- /dev/null
+++ b/benchmark/io_nonblock_noex2.rb
@@ -0,0 +1,21 @@
+nr = 1_000_000
+i = 0
+msg = '.'
+buf = '.'
+begin
+  r, w = IO.pipe
+  while i < nr
+    i += 1
+    w.write_nonblock(msg, exception: false)
+    r.read_nonblock(1, buf, exception: false)
+  end
+rescue ArgumentError # old Rubies
+  while i < nr
+    i += 1
+    w.write_nonblock(msg)
+    r.read_nonblock(1, buf)
+  end
+ensure
+  r.close
+  w.close
+end
diff --git a/benchmark/io_pipe_rw.rb b/benchmark/io_pipe_rw.rb
new file mode 100644
index 0000000000..6862a8ae61
--- /dev/null
+++ b/benchmark/io_pipe_rw.rb
@@ -0,0 +1,13 @@
+# Measure uncontended GVL performance via read/write with 1:1 threading
+# If we switch to M:N threading, this will benchmark something else...
+r, w = IO.pipe
+src = '0'.freeze
+dst = String.new
+i = 0
+while i < 1_000_000
+  i += 1
+  w.write(src)
+  r.read(1, dst)
+end
+w.close
+r.close
diff --git a/benchmark/io_select.rb b/benchmark/io_select.rb
new file mode 100644
index 0000000000..19248daeb1
--- /dev/null
+++ b/benchmark/io_select.rb
@@ -0,0 +1,9 @@
+# IO.select performance
+
+w = [ IO.pipe[1] ];
+
+nr = 1000000
+nr.times {
+  IO.select nil, w
+}
+
diff --git a/benchmark/io_select2.rb b/benchmark/io_select2.rb
new file mode 100644
index 0000000000..10e37d71b2
--- /dev/null
+++ b/benchmark/io_select2.rb
@@ -0,0 +1,22 @@
+# IO.select performance. worst case of single fd.
+
+ios = []
+nr = 1000000
+if defined?(Process::RLIMIT_NOFILE)
+  max = Process.getrlimit(Process::RLIMIT_NOFILE)[0]
+else
+  max = 64
+end
+puts "max fd: #{max} (results not apparent with <= 1024 max fd)"
+
+((max / 2) - 10).times do
+  ios.concat IO.pipe
+end
+
+last = [ ios[-1] ]
+puts "last IO: #{last[0].inspect}"
+
+nr.times do
+  IO.select nil, last
+end
+
diff --git a/benchmark/io_select3.rb b/benchmark/io_select3.rb
new file mode 100644
index 0000000000..7d0ba1f092
--- /dev/null
+++ b/benchmark/io_select3.rb
@@ -0,0 +1,21 @@
+# IO.select performance. a lot of fd
+
+ios = []
+nr = 100
+if defined?(Process::RLIMIT_NOFILE)
+  max = Process.getrlimit(Process::RLIMIT_NOFILE)[0]
+else
+  max = 64
+end
+puts "max fd: #{max} (results not apparent with <= 1024 max fd)"
+
+(max - 10).times do
+  r, w = IO.pipe
+  r.close
+  ios.push w
+end
+
+nr.times do
+  IO.select nil, ios
+end
+
diff --git a/benchmark/irb_color.yml b/benchmark/irb_color.yml
new file mode 100644
index 0000000000..ebdc8d7e8b
--- /dev/null
+++ b/benchmark/irb_color.yml
@@ -0,0 +1,13 @@
+prelude: |
+  require 'irb/color'
+  code = <<~'CODE'
+    def self.foo # bar
+      :"erb #{ERB.new("<%= self %>", trim_mode: ?-).result}"
+    end
+  CODE
+benchmark:
+  irb_color_complete: |
+    IRB::Color.colorize_code(code, complete: true)
+  irb_color_incomplete: |
+    IRB::Color.colorize_code(code, complete: false)
+loop_count: 2000000
diff --git a/benchmark/irb_exec.yml b/benchmark/irb_exec.yml
new file mode 100644
index 0000000000..28933f8b38
--- /dev/null
+++ b/benchmark/irb_exec.yml
@@ -0,0 +1,10 @@
+prelude: |
+  # frozen_string_literal: true
+  require 'rbconfig'
+  irb_f = [File.join(File.dirname(RbConfig.ruby), 'irb'), '-f']
+benchmark:
+  irb_exec: |
+    IO.popen(irb_f, 'w') do |io|
+      io.write('exit')
+    end
+loop_count: 30
diff --git a/benchmark/kernel_clone.yml b/benchmark/kernel_clone.yml
new file mode 100644
index 0000000000..069b23abcd
--- /dev/null
+++ b/benchmark/kernel_clone.yml
@@ -0,0 +1,6 @@
+prelude: "object = Object.new"
+benchmark:
+  clone: "object.clone"
+  clone_true: "object.clone(freeze: true)"
+  clone_false: "object.clone(freeze: false)"
+loop_count: 10000
diff --git a/benchmark/kernel_float.yml b/benchmark/kernel_float.yml
new file mode 100644
index 0000000000..215f6750fc
--- /dev/null
+++ b/benchmark/kernel_float.yml
@@ -0,0 +1,5 @@
+benchmark:
+  float: "Float(42)"
+  float_true: "Float(42, exception: true)"
+  float_false: "Float(42, exception: false)"
+loop_count: 10000
diff --git a/benchmark/kernel_tap.yml b/benchmark/kernel_tap.yml
new file mode 100644
index 0000000000..4dcbb31b4d
--- /dev/null
+++ b/benchmark/kernel_tap.yml
@@ -0,0 +1,6 @@
+prelude: |
+  obj = Object.new
+  x = nil
+benchmark:
+  kernel_tap: obj.tap { |o| x = o }
+loop_count: 20000000
diff --git a/benchmark/kernel_then.yml b/benchmark/kernel_then.yml
new file mode 100644
index 0000000000..85f7341e33
--- /dev/null
+++ b/benchmark/kernel_then.yml
@@ -0,0 +1,6 @@
+benchmark:
+  kernel_then: 1.then { |i| i + 1 }
+  kernel_then_enum: 1.then
+  kernel_yield_self: 1.yield_self { |i| i + 1 }
+  kernel_yield_self_enum: 1.yield_self
+loop_count: 20000000
diff --git a/benchmark/keyword_arguments.yml b/benchmark/keyword_arguments.yml
new file mode 100644
index 0000000000..fce6bce0b8
--- /dev/null
+++ b/benchmark/keyword_arguments.yml
@@ -0,0 +1,13 @@
+prelude: |
+  h = {a: 1}
+  def kw(a: 1) a end
+  def kws(**kw) kw end
+benchmark:
+  kw_to_kw: "kw(a: 1)"
+  kw_splat_to_kw: "kw(**h)"
+  kw_to_kw_splat: "kws(a: 1)"
+  kw_splat_to_kw_splat: "kws(**h)"
+  kw_and_splat_to_kw: "kw(a: 1, **h)"
+  kw_splats_to_kw: "kw(**h, **h)"
+  kw_and_splat_to_kw_splat: "kws(a: 1, **h)"
+  kw_splats_to_kw_splat: "kws(**h, **h)"
diff --git a/benchmark/lib/benchmark_driver/output/driver.rb b/benchmark/lib/benchmark_driver/output/driver.rb
new file mode 100644
index 0000000000..d22236e9fb
--- /dev/null
+++ b/benchmark/lib/benchmark_driver/output/driver.rb
@@ -0,0 +1,36 @@
+require 'benchmark_driver/output/simple'
+
+# This replicates the legacy benchmark/driver.rb behavior.
+class BenchmarkDriver::Output::Driver < BenchmarkDriver::Output::Simple
+  def initialize(*)
+    super
+    @stdout = $stdout
+    @strio  = StringIO.new
+    $stdout = IOMultiplexer.new(@stdout, @strio)
+  end
+
+  def with_benchmark(*)
+    super
+  ensure
+    logfile = "bmlog-#{Time.now.strftime('%Y%m%d-%H%M%S')}.#{$$}.log"
+    puts "\nLog file: #{logfile}"
+
+    $stdout = @stdout
+    File.write(logfile, @strio.tap(&:rewind).read)
+  end
+
+  class IOMultiplexer
+    def initialize(io1, io2)
+      @io1 = io1
+      @io2 = io2
+    end
+
+    [:write, :sync, :sync=, :puts, :print, :flush].each do |method|
+      define_method(method) do |*args|
+        @io1.send(method, *args)
+        @io2.send(method, *args)
+      end
+    end
+  end
+  private_constant :IOMultiplexer
+end
diff --git a/benchmark/lib/benchmark_driver/runner/cstime.rb b/benchmark/lib/benchmark_driver/runner/cstime.rb
new file mode 100644
index 0000000000..3c3453e527
--- /dev/null
+++ b/benchmark/lib/benchmark_driver/runner/cstime.rb
@@ -0,0 +1,22 @@
+require 'benchmark_driver/runner/total'
+
+class BenchmarkDriver::Runner::Cstime < BenchmarkDriver::Runner::Total
+  METRIC = BenchmarkDriver::Metric.new(name: 'cstime', unit: 's', larger_better: false)
+
+  # JobParser returns this, `BenchmarkDriver::Runner.runner_for` searches "*::Job"
+  Job = Class.new(BenchmarkDriver::DefaultJob)
+  # Dynamically fetched and used by `BenchmarkDriver::JobParser.parse`
+  JobParser = BenchmarkDriver::DefaultJobParser.for(klass: Job, metrics: [METRIC])
+
+  private
+
+  # Overriding BenchmarkDriver::Runner::Total#metric
+  def metric
+    METRIC
+  end
+
+  # Overriding BenchmarkDriver::Runner::Total#target
+  def target
+    :cstime
+  end
+end
diff --git a/benchmark/lib/benchmark_driver/runner/cutime.rb b/benchmark/lib/benchmark_driver/runner/cutime.rb
new file mode 100644
index 0000000000..e139962ef2
--- /dev/null
+++ b/benchmark/lib/benchmark_driver/runner/cutime.rb
@@ -0,0 +1,22 @@
+require 'benchmark_driver/runner/total'
+
+class BenchmarkDriver::Runner::Cutime < BenchmarkDriver::Runner::Total
+  METRIC = BenchmarkDriver::Metric.new(name: 'cutime', unit: 's', larger_better: false)
+
+  # JobParser returns this, `BenchmarkDriver::Runner.runner_for` searches "*::Job"
+  Job = Class.new(BenchmarkDriver::DefaultJob)
+  # Dynamically fetched and used by `BenchmarkDriver::JobParser.parse`
+  JobParser = BenchmarkDriver::DefaultJobParser.for(klass: Job, metrics: [METRIC])
+
+  private
+
+  # Overriding BenchmarkDriver::Runner::Total#metric
+  def metric
+    METRIC
+  end
+
+  # Overriding BenchmarkDriver::Runner::Total#target
+  def target
+    :cutime
+  end
+end
diff --git a/benchmark/lib/benchmark_driver/runner/mjit.rb b/benchmark/lib/benchmark_driver/runner/mjit.rb
new file mode 100644
index 0000000000..1d4693e8be
--- /dev/null
+++ b/benchmark/lib/benchmark_driver/runner/mjit.rb
@@ -0,0 +1,34 @@
+require 'benchmark_driver/struct'
+require 'benchmark_driver/metric'
+require 'erb'
+
+# A runner to measure after-JIT performance easily
+class BenchmarkDriver::Runner::Mjit < BenchmarkDriver::Runner::Ips
+  # JobParser returns this, `BenchmarkDriver::Runner.runner_for` searches "*::Job"
+  Job = Class.new(BenchmarkDriver::DefaultJob)
+
+  # Dynamically fetched and used by `BenchmarkDriver::JobParser.parse`
+  JobParser = BenchmarkDriver::DefaultJobParser.for(klass: Job, metrics: [METRIC]).extend(Module.new{
+    def parse(**)
+      jobs = super
+      jobs.map do |job|
+        job = job.dup
+        job.prelude = "#{job.prelude}\n#{<<~EOS}"
+          if defined?(RubyVM::MJIT) && RubyVM::MJIT.enabled?
+            __bmdv_ruby_i = 0
+            while __bmdv_ruby_i < 10000 # jit_min_calls
+              #{job.script}
+              __bmdv_ruby_i += 1
+            end
+            RubyVM::MJIT.pause # compile
+            #{job.script}
+            RubyVM::MJIT.resume; RubyVM::MJIT.pause # recompile
+            #{job.script}
+            RubyVM::MJIT.resume; RubyVM::MJIT.pause # recompile 2
+          end
+        EOS
+        job
+      end
+    end
+  })
+end
diff --git a/benchmark/lib/benchmark_driver/runner/mjit_exec.rb b/benchmark/lib/benchmark_driver/runner/mjit_exec.rb
new file mode 100644
index 0000000000..eac3dfba84
--- /dev/null
+++ b/benchmark/lib/benchmark_driver/runner/mjit_exec.rb
@@ -0,0 +1,237 @@
+require 'benchmark_driver/struct'
+require 'benchmark_driver/metric'
+require 'erb'
+
+# A special runner dedicated for measuring mjit_exec overhead.
+class BenchmarkDriver::Runner::MjitExec
+  METRIC = BenchmarkDriver::Metric.new(name: 'Iteration per second', unit: 'i/s')
+
+  # JobParser returns this, `BenchmarkDriver::Runner.runner_for` searches "*::Job"
+  Job = ::BenchmarkDriver::Struct.new(
+    :name,        # @param [String] name - This is mandatory for all runner
+    :metrics,     # @param [Array<BenchmarkDriver::Metric>]
+    :num_methods, # @param [Integer] num_methods - The number of methods to be defined
+    :loop_count,  # @param [Integer] loop_count
+    :from_jit,    # @param [TrueClass,FalseClass] from_jit - Whether the mjit_exec() is from JIT or not
+    :to_jit,      # @param [TrueClass,FalseClass] to_jit - Whether the mjit_exec() is to JIT or not
+  )
+  # Dynamically fetched and used by `BenchmarkDriver::JobParser.parse`
+  class << JobParser = Module.new
+    # @param [Array,String] num_methods
+    # @param [Integer] loop_count
+    # @param [TrueClass,FalseClass] from_jit
+    # @param [TrueClass,FalseClass] to_jit
+    def parse(num_methods:, loop_count:, from_jit:, to_jit:)
+      if num_methods.is_a?(String)
+        num_methods = eval(num_methods)
+      end
+
+      num_methods.map do |num|
+        if num_methods.size > 1
+          suffix = "[#{'%4d' % num}]"
+        else
+          suffix = "_#{num}"
+        end
+        Job.new(
+          name: "mjit_exec_#{from_jit ? 'JT' : 'VM'}2#{to_jit ? 'JT' : 'VM'}#{suffix}",
+          metrics: [METRIC],
+          num_methods: num,
+          loop_count: loop_count,
+          from_jit: from_jit,
+          to_jit: to_jit,
+        )
+      end
+    end
+  end
+
+  # @param [BenchmarkDriver::Config::RunnerConfig] config
+  # @param [BenchmarkDriver::Output] output
+  # @param [BenchmarkDriver::Context] contexts
+  def initialize(config:, output:, contexts:)
+    @config = config
+    @output = output
+    @contexts = contexts
+  end
+
+  # This method is dynamically called by `BenchmarkDriver::JobRunner.run`
+  # @param [Array<BenchmarkDriver::Runner::Peak::Job>] jobs
+  def run(jobs)
+    @output.with_benchmark do
+      jobs.each do |job|
+        @output.with_job(name: job.name) do
+          @contexts.each do |context|
+            result = BenchmarkDriver::Repeater.with_repeat(config: @config, larger_better: true, rest_on_average: :average) do
+              run_benchmark(job, context: context)
+            end
+            value, duration = result.value
+            @output.with_context(name: context.name, executable: context.executable, gems: context.gems, prelude: context.prelude) do
+              @output.report(values: { METRIC => value }, duration: duration, loop_count: job.loop_count)
+            end
+          end
+        end
+      end
+    end
+  end
+
+  private
+
+  # @param [BenchmarkDriver::Runner::Ips::Job] job - loop_count is not nil
+  # @param [BenchmarkDriver::Context] context
+  # @return [BenchmarkDriver::Metrics]
+  def run_benchmark(job, context:)
+    if job.from_jit
+      if job.to_jit
+        benchmark = BenchmarkJT2JT.new(num_methods: job.num_methods, loop_count: job.loop_count)
+      else
+        raise NotImplementedError, "JT2VM is not implemented yet"
+      end
+    else
+      if job.to_jit
+        benchmark = BenchmarkVM2JT.new(num_methods: job.num_methods, loop_count: job.loop_count)
+      else
+        benchmark = BenchmarkVM2VM.new(num_methods: job.num_methods, loop_count: job.loop_count)
+      end
+    end
+
+    duration = Tempfile.open(['benchmark_driver-result', '.txt']) do |f|
+      with_script(benchmark.render(result: f.path)) do |path|
+        opt = []
+        if context.executable.command.any? { |c| c.start_with?('--jit') }
+          opt << '--jit-min-calls=2'
+        end
+        IO.popen([*context.executable.command, '--disable-gems', *opt, path], &:read)
+        if $?.success?
+          Float(f.read)
+        else
+          BenchmarkDriver::Result::ERROR
+        end
+      end
+    end
+
+    [job.loop_count.to_f / duration, duration]
+  end
+
+  def with_script(script)
+    if @config.verbose >= 2
+      sep = '-' * 30
+      $stdout.puts "\n\n#{sep}[Script begin]#{sep}\n#{script}#{sep}[Script end]#{sep}\n\n"
+    end
+
+    Tempfile.open(['benchmark_driver-', '.rb']) do |f|
+      f.puts script
+      f.close
+      return yield(f.path)
+    end
+  end
+
+  # @param [Integer] num_methods
+  # @param [Integer] loop_count
+  BenchmarkVM2VM = ::BenchmarkDriver::Struct.new(:num_methods, :loop_count) do
+    # @param [String] result - A file to write result
+    def render(result:)
+      ERB.new(<<~EOS, trim_mode: '%').result(binding)
+        % num_methods.times do |i|
+        def a<%= i %>
+          nil
+        end
+        % end
+        RubyVM::MJIT.pause if defined?(RubyVM::MJIT) && RubyVM::MJIT.enabled?
+
+        def vm
+          t = Process.clock_gettime(Process::CLOCK_MONOTONIC)
+          i = 0
+          while i < <%= loop_count / 1000 %>
+        % 1000.times do |i|
+            a<%= i % num_methods %>
+        % end
+            i += 1
+          end
+        % (loop_count % 1000).times do |i|
+          a<%= i % num_methods %>
+        % end
+          Process.clock_gettime(Process::CLOCK_MONOTONIC) - t
+        end
+
+        vm # warmup call cache
+        File.write(<%= result.dump %>, vm)
+      EOS
+    end
+  end
+  private_constant :BenchmarkVM2VM
+
+  # @param [Integer] num_methods
+  # @param [Integer] loop_count
+  BenchmarkVM2JT = ::BenchmarkDriver::Struct.new(:num_methods, :loop_count) do
+    # @param [String] result - A file to write result
+    def render(result:)
+      ERB.new(<<~EOS, trim_mode: '%').result(binding)
+        % num_methods.times do |i|
+        def a<%= i %>
+          nil
+        end
+        a<%= i %>
+        a<%= i %> # --jit-min-calls=2
+        % end
+        RubyVM::MJIT.pause if defined?(RubyVM::MJIT) && RubyVM::MJIT.enabled?
+
+        def vm
+          t = Process.clock_gettime(Process::CLOCK_MONOTONIC)
+          i = 0
+          while i < <%= loop_count / 1000 %>
+        % 1000.times do |i|
+            a<%= i % num_methods %>
+        % end
+            i += 1
+          end
+        % (loop_count % 1000).times do |i|
+          a<%= i % num_methods %>
+        % end
+          Process.clock_gettime(Process::CLOCK_MONOTONIC) - t
+        end
+
+        vm # warmup call cache
+        File.write(<%= result.dump %>, vm)
+      EOS
+    end
+  end
+  private_constant :BenchmarkVM2JT
+
+  # @param [Integer] num_methods
+  # @param [Integer] loop_count
+  BenchmarkJT2JT = ::BenchmarkDriver::Struct.new(:num_methods, :loop_count) do
+    # @param [String] result - A file to write result
+    def render(result:)
+      ERB.new(<<~EOS, trim_mode: '%').result(binding)
+        % num_methods.times do |i|
+        def a<%= i %>
+          nil
+        end
+        % end
+
+        # You may need to:
+        #   * Increase `JIT_ISEQ_SIZE_THRESHOLD` to 10000000 in mjit.h
+        #   * Always return false in `inlinable_iseq_p()` of mjit_compile.c
+        def jit
+          t = Process.clock_gettime(Process::CLOCK_MONOTONIC)
+          i = 0
+          while i < <%= loop_count / 1000 %>
+        % 1000.times do |i|
+            a<%= i % num_methods %>
+        % end
+            i += 1
+          end
+        % (loop_count % 1000).times do |i|
+          a<%= i % num_methods %>
+        % end
+          Process.clock_gettime(Process::CLOCK_MONOTONIC) - t
+        end
+
+        jit
+        jit
+        RubyVM::MJIT.pause if defined?(RubyVM::MJIT) && RubyVM::MJIT.enabled?
+        File.write(<%= result.dump %>, jit)
+      EOS
+    end
+  end
+  private_constant :BenchmarkJT2JT
+end
diff --git a/benchmark/lib/benchmark_driver/runner/peak.rb b/benchmark/lib/benchmark_driver/runner/peak.rb
new file mode 100644
index 0000000000..d04f2e51ff
--- /dev/null
+++ b/benchmark/lib/benchmark_driver/runner/peak.rb
@@ -0,0 +1,151 @@
+require 'benchmark_driver/struct'
+require 'benchmark_driver/metric'
+require 'benchmark_driver/default_job'
+require 'benchmark_driver/default_job_parser'
+require 'tempfile'
+
+class BenchmarkDriver::Runner::Peak
+  METRIC = BenchmarkDriver::Metric.new(
+    name: 'Peak memory usage', unit: 'bytes', larger_better: false, worse_word: 'larger',
+  )
+
+  # JobParser returns this, `BenchmarkDriver::Runner.runner_for` searches "*::Job"
+  Job = Class.new(BenchmarkDriver::DefaultJob)
+  # Dynamically fetched and used by `BenchmarkDriver::JobParser.parse`
+  JobParser = BenchmarkDriver::DefaultJobParser.for(klass: Job, metrics: [METRIC])
+
+  # @param [BenchmarkDriver::Config::RunnerConfig] config
+  # @param [BenchmarkDriver::Output] output
+  # @param [BenchmarkDriver::Context] contexts
+  def initialize(config:, output:, contexts:)
+    @config = config
+    @output = output
+    @contexts = contexts
+  end
+
+  # This method is dynamically called by `BenchmarkDriver::JobRunner.run`
+  # @param [Array<BenchmarkDriver::Runner::Peak::Job>] jobs
+  def run(jobs)
+    if jobs.any? { |job| job.loop_count.nil? }
+      jobs = jobs.map do |job|
+        job.loop_count ? job : Job.new(job.to_h.merge(loop_count: 1))
+      end
+    end
+
+    @output.with_benchmark do
+      jobs.each do |job|
+        @output.with_job(name: job.name) do
+          job.runnable_contexts(@contexts).each do |context|
+            value = BenchmarkDriver::Repeater.with_repeat(config: @config, larger_better: false) do
+              run_benchmark(job, context: context)
+            end
+            @output.with_context(name: context.name, executable: context.executable, gems: context.gems, prelude: context.prelude) do
+              @output.report(values: { metric => value }, loop_count: job.loop_count)
+            end
+          end
+        end
+      end
+    end
+  end
+
+  private
+
+  # @param [BenchmarkDriver::Runner::Ips::Job] job - loop_count is not nil
+  # @param [BenchmarkDriver::Context] context
+  # @return [BenchmarkDriver::Metrics]
+  def run_benchmark(job, context:)
+    benchmark = BenchmarkScript.new(
+      preludes:   [context.prelude, job.prelude],
+      script:     job.script,
+      teardown:   job.teardown,
+      loop_count: job.loop_count,
+    )
+
+    memory_status = File.expand_path('../../../../tool/lib/memory_status', __dir__)
+    Tempfile.open(['benchmark_driver-', '.rb']) do |f|
+      with_script(benchmark.render) do |path|
+        output = IO.popen([*context.executable.command, path, f.path, target, memory_status], &:read)
+        if $?.success?
+          Integer(f.read)
+        else
+          $stdout.print(output)
+          BenchmarkDriver::Result::ERROR
+        end
+      end
+    end
+  end
+
+  # Overridden by BenchmarkDriver::Runner::Size
+  def target
+    'peak'
+  end
+
+  # Overridden by BenchmarkDriver::Runner::Size
+  def metric
+    METRIC
+  end
+
+  def with_script(script)
+    if @config.verbose >= 2
+      sep = '-' * 30
+      $stdout.puts "\n\n#{sep}[Script begin]#{sep}\n#{script}#{sep}[Script end]#{sep}\n\n"
+    end
+
+    Tempfile.open(['benchmark_driver-', '.rb']) do |f|
+      f.puts script
+      f.close
+      return yield(f.path)
+    end
+  end
+
+  # @param [String] prelude
+  # @param [String] script
+  # @param [String] teardown
+  # @param [Integer] loop_count
+  BenchmarkScript = ::BenchmarkDriver::Struct.new(:preludes, :script, :teardown, :loop_count) do
+    def render
+      prelude = preludes.reject(&:nil?).reject(&:empty?).join("\n")
+      <<-RUBY
+#{prelude}
+#{while_loop(script, loop_count)}
+#{teardown}
+
+result_file, target, memory_status = ARGV
+require_relative memory_status
+
+ms = Memory::Status.new
+case target.to_sym
+when :peak
+  key = ms.respond_to?(:hwm) ? :hwm : :peak
+when :size
+  key = ms.respond_to?(:rss) ? :rss : :size
+else
+  raise('unexpected target: ' + target)
+end
+
+File.write(result_file, ms[key])
+      RUBY
+    end
+
+    private
+
+    def while_loop(content, times)
+      if !times.is_a?(Integer) || times <= 0
+        raise ArgumentError.new("Unexpected times: #{times.inspect}")
+      end
+
+      if times > 1
+        <<-RUBY
+__bmdv_i = 0
+while __bmdv_i < #{times}
+  #{content}
+  __bmdv_i += 1
+end
+        RUBY
+      else
+        content
+      end
+    end
+  end
+  private_constant :BenchmarkScript
+end
diff --git a/benchmark/lib/benchmark_driver/runner/size.rb b/benchmark/lib/benchmark_driver/runner/size.rb
new file mode 100644
index 0000000000..1b31f901c7
--- /dev/null
+++ b/benchmark/lib/benchmark_driver/runner/size.rb
@@ -0,0 +1,25 @@
+require 'benchmark_driver/runner/peak'
+
+# Actually the same as BenchmarkDriver::Runner::Memory
+class BenchmarkDriver::Runner::Size < BenchmarkDriver::Runner::Peak
+  METRIC = BenchmarkDriver::Metric.new(
+    name: 'Max resident set size', unit: 'bytes', larger_better: false, worse_word: 'larger',
+  )
+
+  # JobParser returns this, `BenchmarkDriver::Runner.runner_for` searches "*::Job"
+  Job = Class.new(BenchmarkDriver::DefaultJob)
+  # Dynamically fetched and used by `BenchmarkDriver::JobParser.parse`
+  JobParser = BenchmarkDriver::DefaultJobParser.for(klass: Job, metrics: [METRIC])
+
+  private
+
+  # Overriding BenchmarkDriver::Runner::Peak#metric
+  def metric
+    METRIC
+  end
+
+  # Overriding BenchmarkDriver::Runner::Peak#target
+  def target
+    'size'
+  end
+end
diff --git a/benchmark/lib/benchmark_driver/runner/stime.rb b/benchmark/lib/benchmark_driver/runner/stime.rb
new file mode 100644
index 0000000000..4577fb0bf8
--- /dev/null
+++ b/benchmark/lib/benchmark_driver/runner/stime.rb
@@ -0,0 +1,22 @@
+require 'benchmark_driver/runner/total'
+
+class BenchmarkDriver::Runner::Stime < BenchmarkDriver::Runner::Total
+  METRIC = BenchmarkDriver::Metric.new(name: 'stime', unit: 's', larger_better: false)
+
+  # JobParser returns this, `BenchmarkDriver::Runner.runner_for` searches "*::Job"
+  Job = Class.new(BenchmarkDriver::DefaultJob)
+  # Dynamically fetched and used by `BenchmarkDriver::JobParser.parse`
+  JobParser = BenchmarkDriver::DefaultJobParser.for(klass: Job, metrics: [METRIC])
+
+  private
+
+  # Overriding BenchmarkDriver::Runner::Total#metric
+  def metric
+    METRIC
+  end
+
+  # Overriding BenchmarkDriver::Runner::Total#target
+  def target
+    :stime
+  end
+end
diff --git a/benchmark/lib/benchmark_driver/runner/total.rb b/benchmark/lib/benchmark_driver/runner/total.rb
new file mode 100644
index 0000000000..64dc14f84e
--- /dev/null
+++ b/benchmark/lib/benchmark_driver/runner/total.rb
@@ -0,0 +1,137 @@
+require 'benchmark_driver/struct'
+require 'benchmark_driver/metric'
+require 'benchmark_driver/default_job'
+require 'benchmark_driver/default_job_parser'
+require 'tempfile'
+
+class BenchmarkDriver::Runner::Total
+  METRIC = BenchmarkDriver::Metric.new(name: 'Total time', unit: 's', larger_better: false)
+
+  # JobParser returns this, `BenchmarkDriver::Runner.runner_for` searches "*::Job"
+  Job = Class.new(BenchmarkDriver::DefaultJob)
+  # Dynamically fetched and used by `BenchmarkDriver::JobParser.parse`
+  JobParser = BenchmarkDriver::DefaultJobParser.for(klass: Job, metrics: [METRIC])
+
+  # @param [BenchmarkDriver::Config::RunnerConfig] config
+  # @param [BenchmarkDriver::Output] output
+  # @param [BenchmarkDriver::Context] contexts
+  def initialize(config:, output:, contexts:)
+    @config = config
+    @output = output
+    @contexts = contexts
+  end
+
+  # This method is dynamically called by `BenchmarkDriver::JobRunner.run`
+  # @param [Array<BenchmarkDriver::Runner::Total::Job>] jobs
+  def run(jobs)
+    if jobs.any? { |job| job.loop_count.nil? }
+      raise 'missing loop_count is not supported in Ruby repository'
+    end
+
+    @output.with_benchmark do
+      jobs.each do |job|
+        @output.with_job(name: job.name) do
+          job.runnable_contexts(@contexts).each do |context|
+            duration = BenchmarkDriver::Repeater.with_repeat(config: @config, larger_better: false) do
+              run_benchmark(job, context: context)
+            end
+            @output.with_context(name: context.name, executable: context.executable, gems: context.gems, prelude: context.prelude) do
+              @output.report(values: { metric => duration }, duration: duration, loop_count: job.loop_count)
+            end
+          end
+        end
+      end
+    end
+  end
+
+  private
+
+  # @param [BenchmarkDriver::Runner::Ips::Job] job - loop_count is not nil
+  # @param [BenchmarkDriver::Context] context
+  # @return [BenchmarkDriver::Metrics]
+  def run_benchmark(job, context:)
+    benchmark = BenchmarkScript.new(
+      preludes:   [context.prelude, job.prelude],
+      script:     job.script,
+      teardown:   job.teardown,
+      loop_count: job.loop_count,
+    )
+
+    Tempfile.open(['benchmark_driver-', '.rb']) do |f|
+      with_script(benchmark.render(result: f.path, target: target)) do |path|
+        IO.popen([*context.executable.command, path], &:read) # TODO: print stdout if verbose=2
+        if $?.success?
+          Float(f.read)
+        else
+          BenchmarkDriver::Result::ERROR
+        end
+      end
+    end
+  end
+
+  # This method is overridden by some subclasses
+  def metric
+    METRIC
+  end
+
+  # This method is overridden by some subclasses
+  def target
+    :total
+  end
+
+  def with_script(script)
+    if @config.verbose >= 2
+      sep = '-' * 30
+      $stdout.puts "\n\n#{sep}[Script begin]#{sep}\n#{script}#{sep}[Script end]#{sep}\n\n"
+    end
+
+    Tempfile.open(['benchmark_driver-', '.rb']) do |f|
+      f.puts script
+      f.close
+      return yield(f.path)
+    end
+  end
+
+  # @param [String] prelude
+  # @param [String] script
+  # @param [String] teardown
+  # @param [Integer] loop_count
+  BenchmarkScript = ::BenchmarkDriver::Struct.new(:preludes, :script, :teardown, :loop_count) do
+    # @param [String] result - A file to write result
+    def render(result:, target:)
+      prelude = preludes.reject(&:nil?).reject(&:empty?).join("\n")
+      <<-RUBY
+#{prelude}
+
+require 'benchmark'
+__bmdv_result = Benchmark.measure {
+  #{while_loop(script, loop_count)}
+}
+
+#{teardown}
+
+File.write(#{result.dump}, __bmdv_result.#{target})
+      RUBY
+    end
+
+    private
+
+    def while_loop(content, times)
+      if !times.is_a?(Integer) || times <= 0
+        raise ArgumentError.new("Unexpected times: #{times.inspect}")
+      elsif times == 1
+        return content
+      end
+
+      # TODO: execute in batch
+      <<-RUBY
+__bmdv_i = 0
+while __bmdv_i < #{times}
+  #{content}
+  __bmdv_i += 1
+end
+      RUBY
+    end
+  end
+  private_constant :BenchmarkScript
+end
diff --git a/benchmark/lib/benchmark_driver/runner/utime.rb b/benchmark/lib/benchmark_driver/runner/utime.rb
new file mode 100644
index 0000000000..b61d83a188
--- /dev/null
+++ b/benchmark/lib/benchmark_driver/runner/utime.rb
@@ -0,0 +1,22 @@
+require 'benchmark_driver/runner/total'
+
+class BenchmarkDriver::Runner::Utime < BenchmarkDriver::Runner::Total
+  METRIC = BenchmarkDriver::Metric.new(name: 'utime', unit: 's', larger_better: false)
+
+  # JobParser returns this, `BenchmarkDriver::Runner.runner_for` searches "*::Job"
+  Job = Class.new(BenchmarkDriver::DefaultJob)
+  # Dynamically fetched and used by `BenchmarkDriver::JobParser.parse`
+  JobParser = BenchmarkDriver::DefaultJobParser.for(klass: Job, metrics: [METRIC])
+
+  private
+
+  # Overriding BenchmarkDriver::Runner::Total#metric
+  def metric
+    METRIC
+  end
+
+  # Overriding BenchmarkDriver::Runner::Total#target
+  def target
+    :utime
+  end
+end
diff --git a/benchmark/lib/load.rb b/benchmark/lib/load.rb
new file mode 100644
index 0000000000..31b770c484
--- /dev/null
+++ b/benchmark/lib/load.rb
@@ -0,0 +1,18 @@
+# How to use this file:
+#   1. write a `$(srcdir)/test.rb` like:
+=begin
+require_relative 'benchmark/lib/load'
+
+Benchmark.driver(repeat_count: 5){|x|
+  x.executable name: 'clean-miniruby', command: %w'../clean-trunk/miniruby'
+  x.executable name: 'modif-miniruby', command: %w'./miniruby'
+
+  x.report %q{
+    h = {a: 1, b: 2, c: 3, d: 4}
+  }
+}
+=end
+#
+#  2. `make run`
+$:.unshift(File.join(__dir__, '../benchmark-driver/lib'))
+require 'benchmark_driver'
diff --git a/benchmark/loop_for.rb b/benchmark/loop_for.rb
new file mode 100644
index 0000000000..0fc4cc1511
--- /dev/null
+++ b/benchmark/loop_for.rb
@@ -0,0 +1,3 @@
+for i in 1..30_000_000
+  #
+end
diff --git a/benchmark/loop_generator.rb b/benchmark/loop_generator.rb
new file mode 100644
index 0000000000..d3375c744c
--- /dev/null
+++ b/benchmark/loop_generator.rb
@@ -0,0 +1,14 @@
+max = 600000
+
+if defined? Fiber
+  gen = (1..max).each
+  loop do
+    gen.next
+  end
+else
+  require 'generator'
+  gen = Generator.new((0..max))
+  while gen.next?
+    gen.next
+  end
+end
diff --git a/benchmark/loop_times.rb b/benchmark/loop_times.rb
new file mode 100644
index 0000000000..521f72ad1a
--- /dev/null
+++ b/benchmark/loop_times.rb
@@ -0,0 +1 @@
+30_000_000.times{|e|}
diff --git a/benchmark/loop_whileloop.rb b/benchmark/loop_whileloop.rb
new file mode 100644
index 0000000000..0072822c06
--- /dev/null
+++ b/benchmark/loop_whileloop.rb
@@ -0,0 +1,4 @@
+i = 0
+while i<30_000_000 # benchmark loop 1
+  i += 1
+end
diff --git a/benchmark/loop_whileloop2.rb b/benchmark/loop_whileloop2.rb
new file mode 100644
index 0000000000..47d02dffc4
--- /dev/null
+++ b/benchmark/loop_whileloop2.rb
@@ -0,0 +1,4 @@
+i = 0
+while i< 6_000_000 # benchmark loop 2
+  i += 1
+end
diff --git a/benchmark/marshal_dump_flo.rb b/benchmark/marshal_dump_flo.rb
new file mode 100644
index 0000000000..9b8d0c6afb
--- /dev/null
+++ b/benchmark/marshal_dump_flo.rb
@@ -0,0 +1,2 @@
+bug10761 = 10000.times.map { |x| x.to_f }
+100.times { Marshal.dump(bug10761) }
diff --git a/benchmark/marshal_dump_load_geniv.rb b/benchmark/marshal_dump_load_geniv.rb
new file mode 100644
index 0000000000..8252ad90fa
--- /dev/null
+++ b/benchmark/marshal_dump_load_geniv.rb
@@ -0,0 +1,10 @@
+a = ''
+a.instance_eval do
+  @a = :a
+  @b = :b
+  @c = :c
+end
+100000.times do
+  a = Marshal.load(Marshal.dump(a))
+end
+#p(a.instance_eval { @a == :a && @b == :b && @c == :c })
diff --git a/benchmark/marshal_dump_load_time.rb b/benchmark/marshal_dump_load_time.rb
new file mode 100644
index 0000000000..e29743b791
--- /dev/null
+++ b/benchmark/marshal_dump_load_time.rb
@@ -0,0 +1 @@
+100000.times { Marshal.load(Marshal.dump(Time.now)) }
diff --git a/benchmark/match_gt4.rb b/benchmark/match_gt4.rb
new file mode 100644
index 0000000000..ffda109912
--- /dev/null
+++ b/benchmark/match_gt4.rb
@@ -0,0 +1 @@
+1000000.times { /(.)(.)(\d+)(\d)/.match("THX1138.") }
diff --git a/benchmark/match_small.rb b/benchmark/match_small.rb
new file mode 100644
index 0000000000..3b743d484a
--- /dev/null
+++ b/benchmark/match_small.rb
@@ -0,0 +1 @@
+1000000.times { 'haystack'.match(/hay/) }
diff --git a/benchmark/mjit_exec_jt2jt.yml b/benchmark/mjit_exec_jt2jt.yml
new file mode 100644
index 0000000000..6c303c7a44
--- /dev/null
+++ b/benchmark/mjit_exec_jt2jt.yml
@@ -0,0 +1,6 @@
+type: lib/benchmark_driver/runner/mjit_exec
+num_methods: [1]
+#num_methods: (1..100).to_a + [200, 300, 400, 500, 600, 700, 800, 900, 1000]
+loop_count: 50000000
+from_jit: true
+to_jit: true
diff --git a/benchmark/mjit_exec_vm2jt.yml b/benchmark/mjit_exec_vm2jt.yml
new file mode 100644
index 0000000000..764883f070
--- /dev/null
+++ b/benchmark/mjit_exec_vm2jt.yml
@@ -0,0 +1,6 @@
+type: lib/benchmark_driver/runner/mjit_exec
+num_methods: [1]
+#num_methods: (1..100).to_a + [200, 300, 400, 500, 600, 700, 800, 900, 1000]
+loop_count: 50000000
+from_jit: false
+to_jit: true
diff --git a/benchmark/mjit_exec_vm2vm.yml b/benchmark/mjit_exec_vm2vm.yml
new file mode 100644
index 0000000000..030aa76c1c
--- /dev/null
+++ b/benchmark/mjit_exec_vm2vm.yml
@@ -0,0 +1,6 @@
+type: lib/benchmark_driver/runner/mjit_exec
+num_methods: [1]
+#num_methods: (1..100).to_a + [200, 300, 400, 500, 600, 700, 800, 900, 1000]
+loop_count: 50000000
+from_jit: false
+to_jit: false
diff --git a/benchmark/mjit_exivar.yml b/benchmark/mjit_exivar.yml
new file mode 100644
index 0000000000..2584fa6410
--- /dev/null
+++ b/benchmark/mjit_exivar.yml
@@ -0,0 +1,18 @@
+type: lib/benchmark_driver/runner/mjit
+prelude: |
+  class Bench < Hash
+    def initialize
+      @exivar = nil
+    end
+
+    def exivar
+      @exivar
+    end
+  end
+
+  bench = Bench.new
+
+benchmark:
+  mjit_exivar: bench.exivar
+
+loop_count: 200000000
diff --git a/benchmark/mjit_integer.yml b/benchmark/mjit_integer.yml
new file mode 100644
index 0000000000..edc3556479
--- /dev/null
+++ b/benchmark/mjit_integer.yml
@@ -0,0 +1,30 @@
+type: lib/benchmark_driver/runner/mjit
+prelude: |
+  def mjit_abs(int)        int.abs        end
+  def mjit_bit_length(int) int.bit_length end
+  def mjit_comp(int)       ~int           end
+  def mjit_even?(int)      int.even?      end
+  def mjit_integer?(int)   int.integer?   end
+  def mjit_magnitude(int)  int.magnitude  end
+  def mjit_odd?(int)       int.odd?       end
+  def mjit_ord(int)        int.ord        end
+  def mjit_to_i(int)       int.to_i       end
+  def mjit_to_int(int)     int.to_int     end
+  def mjit_uminus(int)     -int           end
+  def mjit_zero?(int)      int.zero?      end
+
+benchmark:
+  - mjit_abs(-1)
+  - mjit_bit_length(100)
+  - mjit_comp(1)
+  - mjit_even?(2)
+  - mjit_integer?(0)
+  - mjit_magnitude(-1)
+  - mjit_odd?(1)
+  - mjit_ord(1)
+  - mjit_to_i(1)
+  - mjit_to_int(1)
+  - mjit_uminus(1)
+  - mjit_zero?(0)
+
+loop_count: 40000000
diff --git a/benchmark/mjit_kernel.yml b/benchmark/mjit_kernel.yml
new file mode 100644
index 0000000000..7720e65c2c
--- /dev/null
+++ b/benchmark/mjit_kernel.yml
@@ -0,0 +1,20 @@
+type: lib/benchmark_driver/runner/mjit
+prelude: |
+  def mjit_class(obj)
+    obj.class
+  end
+
+  def mjit_frozen?(obj)
+    obj.frozen?
+  end
+
+  str = ""
+  fstr = "".freeze
+
+benchmark:
+  - mjit_class(self)
+  - mjit_class(1)
+  - mjit_frozen?(str)
+  - mjit_frozen?(fstr)
+
+loop_count: 40000000
diff --git a/benchmark/mjit_leave.yml b/benchmark/mjit_leave.yml
new file mode 100644
index 0000000000..9ac68b164b
--- /dev/null
+++ b/benchmark/mjit_leave.yml
@@ -0,0 +1,8 @@
+type: lib/benchmark_driver/runner/mjit
+prelude: |
+  def leave
+    nil
+  end
+benchmark:
+  mjit_leave: leave
+loop_count: 200000000
diff --git a/benchmark/mjit_opt_cc_insns.yml b/benchmark/mjit_opt_cc_insns.yml
new file mode 100644
index 0000000000..fed6d34bd5
--- /dev/null
+++ b/benchmark/mjit_opt_cc_insns.yml
@@ -0,0 +1,27 @@
+# opt_* insns using vm_method_cfunc_is with send-compatible operands:
+#   * opt_nil_p
+#   * opt_not
+#   * opt_eq
+type: lib/benchmark_driver/runner/mjit
+prelude: |
+  def mjit_nil?(obj)
+    obj.nil?
+  end
+
+  def mjit_not(obj)
+    !obj
+  end
+
+  def mjit_eq(a, b)
+    a == b
+  end
+
+benchmark:
+  - script: mjit_nil?(1)
+    loop_count: 40000000
+  - script: mjit_not(1)
+    loop_count: 40000000
+  - script: mjit_eq(1, nil)
+    loop_count: 8000000
+  - script: mjit_eq(nil, 1)
+    loop_count: 8000000
diff --git a/benchmark/mjit_struct_aref.yml b/benchmark/mjit_struct_aref.yml
new file mode 100644
index 0000000000..bfba1323f2
--- /dev/null
+++ b/benchmark/mjit_struct_aref.yml
@@ -0,0 +1,10 @@
+type: lib/benchmark_driver/runner/mjit
+prelude: |
+  def mjit_struct_aref(struct)
+    struct.aa
+  end
+  struct = Struct.new(:a0, :a1, :a2, :a3, :a4, :a5, :a6, :a7, :a8, :a9, :aa).new
+
+benchmark: mjit_struct_aref(struct)
+
+loop_count: 40000000
diff --git a/benchmark/nil_p.yml b/benchmark/nil_p.yml
new file mode 100644
index 0000000000..79ba4f2177
--- /dev/null
+++ b/benchmark/nil_p.yml
@@ -0,0 +1,9 @@
+prelude: |
+  class Niller; def nil?; true; end; end
+  xnil, notnil = nil, Object.new
+  niller = Niller.new
+benchmark:
+  - xnil.nil?
+  - notnil.nil?
+  - niller.nil?
+loop_count: 10000000
diff --git a/benchmark/num_zero_p.yml b/benchmark/num_zero_p.yml
new file mode 100644
index 0000000000..2195963433
--- /dev/null
+++ b/benchmark/num_zero_p.yml
@@ -0,0 +1,8 @@
+benchmark:
+  - 0.zero?
+  - 1.zero?
+  - 0r.zero?
+  - 1r.zero?
+  - 0i.zero?
+  - 1i.zero?
+loop_count: 50000000
diff --git a/benchmark/object_allocate.yml b/benchmark/object_allocate.yml
new file mode 100644
index 0000000000..93ff463e41
--- /dev/null
+++ b/benchmark/object_allocate.yml
@@ -0,0 +1,21 @@
+prelude: |
+  class Eight
+    8.times { include(Module.new) }
+  end
+  class ThirtyTwo
+    32.times { include(Module.new) }
+  end
+  class SixtyFour
+    64.times { include(Module.new) }
+  end
+  class OneTwentyEight
+    128.times { include(Module.new) }
+  end
+  # Disable GC to see raw throughput:
+  GC.disable
+benchmark:
+  allocate_8_deep: Eight.new
+  allocate_32_deep: ThirtyTwo.new
+  allocate_64_deep: SixtyFour.new
+  allocate_128_deep: OneTwentyEight.new
+loop_count: 100000
diff --git a/benchmark/objspace_dump_all.yml b/benchmark/objspace_dump_all.yml
new file mode 100644
index 0000000000..ebab562d2e
--- /dev/null
+++ b/benchmark/objspace_dump_all.yml
@@ -0,0 +1,13 @@
+prelude: |
+  require 'objspace'
+  require 'tempfile'
+  $objs = 1_000.times.map { Object.new }
+  $strings = 1_000.times.map { |i| "string #{i}" }
+  $file = Tempfile.new('heap')
+  $dev_null = File.open(File::NULL, 'w+')
+
+benchmark:
+  dump_all_string: "ObjectSpace.dump_all(output: :string)"
+  dump_all_file: "ObjectSpace.dump_all(output: $file)"
+  dump_all_dev_null: "ObjectSpace.dump_all(output: $dev_null)"
+loop_count: 1
diff --git a/benchmark/other-lang/ack.pl b/benchmark/other-lang/ack.pl
new file mode 100644
index 0000000000..201e22ddfa
--- /dev/null
+++ b/benchmark/other-lang/ack.pl
@@ -0,0 +1,11 @@
+use integer;
+
+sub Ack {
+    return $_[0] ? ($_[1] ? Ack($_[0]-1, Ack($_[0], $_[1]-1))
+		    : Ack($_[0]-1, 1))
+	: $_[1]+1;
+}
+
+my $NUM = 9;
+$NUM = 1 if ($NUM < 1);
+my $ack = Ack(3, $NUM);
diff --git a/benchmark/other-lang/ack.py b/benchmark/other-lang/ack.py
new file mode 100644
index 0000000000..9968e7cfcf
--- /dev/null
+++ b/benchmark/other-lang/ack.py
@@ -0,0 +1,16 @@
+import sys
+sys.setrecursionlimit(5000000)
+
+def Ack(M, N):
+    if (not M):
+        return( N + 1 )
+    if (not N):
+        return( Ack(M-1, 1) )
+    return( Ack(M-1, Ack(M, N-1)) )
+
+def main():
+    NUM = 9
+    sys.setrecursionlimit(10000)
+    Ack(3, NUM)
+
+main()
diff --git a/benchmark/other-lang/ack.rb b/benchmark/other-lang/ack.rb
new file mode 100644
index 0000000000..7451bed6c4
--- /dev/null
+++ b/benchmark/other-lang/ack.rb
@@ -0,0 +1,12 @@
+def ack(m, n)
+    if m == 0 then
+        n + 1
+    elsif n == 0 then
+        ack(m - 1, 1)
+    else
+        ack(m - 1, ack(m, n - 1))
+    end
+end
+
+NUM = 9
+ack(3, NUM)
diff --git a/benchmark/other-lang/ack.scm b/benchmark/other-lang/ack.scm
new file mode 100644
index 0000000000..a80b73ba55
--- /dev/null
+++ b/benchmark/other-lang/ack.scm
@@ -0,0 +1,7 @@
+(define (ack m n)
+  (cond ((zero? m) (+ n 1))
+	((zero? n) (ack (- m 1) 1))
+	(else      (ack (- m 1) (ack m (- n 1))))))
+
+(ack 3 9)
+
diff --git a/benchmark/other-lang/eval.rb b/benchmark/other-lang/eval.rb
new file mode 100644
index 0000000000..48a2cea019
--- /dev/null
+++ b/benchmark/other-lang/eval.rb
@@ -0,0 +1,66 @@
+
+Bench = %w(
+  loop
+  ack
+  fib
+  tak
+  fact
+)
+
+Lang = <<EOP.map{|l| l.strip}
+  ruby-cyg
+  ../../../test6/miniruby
+  perl
+  python
+  gosh
+EOP
+
+Bench.replace ['loop2']
+Lang.replace ['ruby-cyg']
+
+Ext = %w(
+  .rb
+  .rb
+  .pl
+  .py
+  .scm
+)
+
+p Bench
+p Lang
+
+require 'benchmark'
+
+def bench cmd
+  m = Benchmark.measure{
+    #p cmd
+    system(cmd)
+  }
+  [m.utime, m.real]
+end
+
+Result = []
+Bench.each{|b|
+  r = []
+  Lang.each_with_index{|l, idx|
+    cmd = "#{l} #{b}#{Ext[idx]}"
+    r << bench(cmd)
+  }
+  Result << r
+}
+
+require 'pp'
+# utime
+puts Lang.join("\t")
+Bench.each_with_index{|b, bi|
+  print b, "\t"
+  puts Result[bi].map{|e| e[0]}.join("\t")
+}
+
+# rtime
+puts Lang.join("\t")
+Bench.each_with_index{|b, bi|
+  print b, "\t"
+  puts Result[bi].map{|e| e[1]}.join("\t")
+}
+
diff --git a/benchmark/other-lang/fact.pl b/benchmark/other-lang/fact.pl
new file mode 100644
index 0000000000..a9b0b69cdf
--- /dev/null
+++ b/benchmark/other-lang/fact.pl
@@ -0,0 +1,13 @@
+sub fact{
+  my $n = @_[0];
+  if($n < 2){
+    return 1;
+  }
+  else{
+    return $n * fact($n-1);
+  }
+}
+
+for($i=0; $i<10000; $i++){
+  &fact(100);
+}
diff --git a/benchmark/other-lang/fact.py b/benchmark/other-lang/fact.py
new file mode 100644
index 0000000000..1ce9f76275
--- /dev/null
+++ b/benchmark/other-lang/fact.py
@@ -0,0 +1,18 @@
+#import sys
+#sys.setrecursionlimit(1000)
+
+def factL(n):
+	r = 1
+	for x in range(2, n+1):
+		r *= x
+	return r
+
+def factR(n):
+	if n < 2:
+		return 1
+	else:
+		return n * factR(n-1)
+
+for i in range(10000):
+	factR(100)
+
diff --git a/benchmark/other-lang/fact.rb b/benchmark/other-lang/fact.rb
new file mode 100644
index 0000000000..6cedc752cd
--- /dev/null
+++ b/benchmark/other-lang/fact.rb
@@ -0,0 +1,13 @@
+def fact(n)
+  if n < 2
+    1
+  else
+    n * fact(n-1)
+  end
+end
+
+i = 0
+while i<10000
+  i += 1
+  fact(100)
+end
diff --git a/benchmark/other-lang/fact.scm b/benchmark/other-lang/fact.scm
new file mode 100644
index 0000000000..c98a7fedd3
--- /dev/null
+++ b/benchmark/other-lang/fact.scm
@@ -0,0 +1,8 @@
+(define (fact n)
+        (if (< n 2)
+            1
+          (* n (fact (- n 1)))))
+
+(dotimes (i 10000)
+  (fact 100))
+
diff --git a/benchmark/other-lang/fib.pl b/benchmark/other-lang/fib.pl
new file mode 100644
index 0000000000..a46f666d1e
--- /dev/null
+++ b/benchmark/other-lang/fib.pl
@@ -0,0 +1,11 @@
+sub fib{
+  my $n = $_[0];
+  if($n < 3){
+    return 1;
+  }
+  else{
+    return fib($n-1) + fib($n-2);
+  }
+};
+
+&fib(34);
diff --git a/benchmark/other-lang/fib.py b/benchmark/other-lang/fib.py
new file mode 100644
index 0000000000..45f2bceb8d
--- /dev/null
+++ b/benchmark/other-lang/fib.py
@@ -0,0 +1,7 @@
+def fib(n):
+  if n < 3:
+    return 1
+  else:
+    return fib(n-1) + fib(n-2)
+
+fib(34)
diff --git a/benchmark/other-lang/fib.rb b/benchmark/other-lang/fib.rb
new file mode 100644
index 0000000000..ec587eabe0
--- /dev/null
+++ b/benchmark/other-lang/fib.rb
@@ -0,0 +1,9 @@
+def fib n
+  if n < 3
+    1
+  else
+    fib(n-1) + fib(n-2)
+  end
+end
+
+fib(34)
diff --git a/benchmark/other-lang/fib.scm b/benchmark/other-lang/fib.scm
new file mode 100644
index 0000000000..2fc4e225bd
--- /dev/null
+++ b/benchmark/other-lang/fib.scm
@@ -0,0 +1,7 @@
+(define (fib n)
+        (if (< n 3)
+            1
+          (+ (fib (- n 1)) (fib (- n 2)))))
+
+(fib 34)
+
diff --git a/benchmark/other-lang/loop.pl b/benchmark/other-lang/loop.pl
new file mode 100644
index 0000000000..2777490aaa
--- /dev/null
+++ b/benchmark/other-lang/loop.pl
@@ -0,0 +1,3 @@
+for($i=0; $i<30000000; $i++){
+}
+
diff --git a/benchmark/other-lang/loop.py b/benchmark/other-lang/loop.py
new file mode 100644
index 0000000000..003749bf3a
--- /dev/null
+++ b/benchmark/other-lang/loop.py
@@ -0,0 +1,2 @@
+for i in xrange(30000000):
+	pass
diff --git a/benchmark/other-lang/loop.rb b/benchmark/other-lang/loop.rb
new file mode 100644
index 0000000000..b367b9dbf3
--- /dev/null
+++ b/benchmark/other-lang/loop.rb
@@ -0,0 +1,4 @@
+i = 0
+while i<30000000
+  i += 1
+end
diff --git a/benchmark/other-lang/loop.scm b/benchmark/other-lang/loop.scm
new file mode 100644
index 0000000000..3364f7e679
--- /dev/null
+++ b/benchmark/other-lang/loop.scm
@@ -0,0 +1 @@
+(dotimes (x 30000000))
diff --git a/benchmark/other-lang/loop2.rb b/benchmark/other-lang/loop2.rb
new file mode 100644
index 0000000000..df8fffc1ff
--- /dev/null
+++ b/benchmark/other-lang/loop2.rb
@@ -0,0 +1 @@
+30000000.times{}
diff --git a/benchmark/other-lang/tak.pl b/benchmark/other-lang/tak.pl
new file mode 100644
index 0000000000..7e748a67c6
--- /dev/null
+++ b/benchmark/other-lang/tak.pl
@@ -0,0 +1,11 @@
+sub tak {
+    local($x, $y, $z) = @_;
+    if (!($y < $x)) {
+	return $z;
+    } else {
+	return &tak(&tak($x - 1, $y, $z),
+		    &tak($y - 1, $z, $x),
+		    &tak($z - 1, $x, $y));
+    }
+}
+&tak(18, 9, 0);
diff --git a/benchmark/other-lang/tak.py b/benchmark/other-lang/tak.py
new file mode 100644
index 0000000000..04f3f6829c
--- /dev/null
+++ b/benchmark/other-lang/tak.py
@@ -0,0 +1,8 @@
+def tak(x, y, z):
+	if not(y<x):
+		return z
+	else:
+		return tak(tak(x-1, y, z),
+		           tak(y-1, z, x),
+		           tak(z-1, x, y))
+tak(18, 9, 0)
diff --git a/benchmark/other-lang/tak.rb b/benchmark/other-lang/tak.rb
new file mode 100644
index 0000000000..efe5380f4e
--- /dev/null
+++ b/benchmark/other-lang/tak.rb
@@ -0,0 +1,13 @@
+
+def tak x, y, z
+  unless y < x
+    z
+  else
+    tak( tak(x-1, y, z),
+         tak(y-1, z, x),
+         tak(z-1, x, y))
+  end
+end
+
+tak(18, 9, 0)
+
diff --git a/benchmark/other-lang/tak.scm b/benchmark/other-lang/tak.scm
new file mode 100644
index 0000000000..52a7629ee5
--- /dev/null
+++ b/benchmark/other-lang/tak.scm
@@ -0,0 +1,10 @@
+(define (tak x y z)
+        (if (not (< y x))
+            z
+          (tak (tak (- x 1) y z)
+               (tak (- y 1) z x)
+               (tak (- z 1) x y))))
+
+(tak 18 9 0)
+
+
diff --git a/benchmark/pm_array.yml b/benchmark/pm_array.yml
new file mode 100644
index 0000000000..babb65a289
--- /dev/null
+++ b/benchmark/pm_array.yml
@@ -0,0 +1,19 @@
+prelude: |
+  def call(*val)
+    case val
+      in [String => body]
+        [200, {}, [body]]
+      in [Integer => status]
+        [status, {}, [""]]
+      in [Integer, String] => response
+        [response[0], {}, [response[1]]]
+      in [Integer, Hash, String] => response
+        [response[0], response[1], [response[2]]]
+    end
+  end
+
+benchmark:
+  first_match: call("ok")
+  second_match: call(401)
+  third_match: call(200, "ok")
+  fourth_match: call(201, {}, "created")
diff --git a/benchmark/range_last.yml b/benchmark/range_last.yml
new file mode 100644
index 0000000000..a6674f82ee
--- /dev/null
+++ b/benchmark/range_last.yml
@@ -0,0 +1,4 @@
+benchmark:
+  - (1..1_000_000).last(100)
+  - (1..1_000_000).last(1000)
+  - (1..1_000_000).last(10000)
diff --git a/benchmark/realpath.yml b/benchmark/realpath.yml
new file mode 100644
index 0000000000..90a029d5b9
--- /dev/null
+++ b/benchmark/realpath.yml
@@ -0,0 +1,30 @@
+prelude: |
+  f = File
+  pwd = Dir.pwd
+  Dir.mkdir('b') unless f.directory?('b')
+  f.write('b/a', '') unless f.file?('b/a')
+
+  relative = 'b/a'
+  absolute = File.join(pwd, relative)
+  dir = 'b'
+  file = 'a'
+
+  relative_dir = 'b/c'
+  absolute_dir = File.join(pwd, relative_dir)
+  file_dir = 'c'
+benchmark:
+  relative_nil: "f.realpath(relative, nil)"
+  absolute_nil: "f.realpath(absolute, nil)"
+  relative_relative: "f.realpath(file, dir)"
+  absolute_relative: "f.realpath(absolute, dir)"
+  relative_absolute: "f.realpath(relative, pwd)"
+  relative_nil_dir: "f.realdirpath(relative_dir, nil)"
+  absolute_nil_dir: "f.realdirpath(absolute_dir, nil)"
+  relative_relative_dir: "f.realdirpath(file_dir, dir)"
+  absolute_relative_dir: "f.realdirpath(absolute_dir, dir)"
+  relative_absolute_dir: "f.realdirpath(relative_dir, pwd)"
+  relative_nil_notexist: "f.realpath(relative_dir, nil) rescue nil"
+  absolute_nil_notexist: "f.realpath(absolute_dir, nil) rescue nil"
+  relative_relative_notexist: "f.realpath(file_dir, dir) rescue nil"
+  absolute_relative_notexist: "f.realpath(absolute_dir, dir) rescue nil"
+  relative_absolute_notexist: "f.realpath(relative_dir, pwd) rescue nil"
diff --git a/benchmark/require.yml b/benchmark/require.yml
new file mode 100644
index 0000000000..09f218cf08
--- /dev/null
+++ b/benchmark/require.yml
@@ -0,0 +1,32 @@
+prelude: |
+  require "fileutils"
+
+  def prepare
+    num_files = 10000
+
+    basename = File.dirname($0)
+    data_dir = File.join(basename, "bm_require.data")
+
+    # skip if all of files exists
+    if File.exist?(File.join(data_dir, "c#{num_files}.rb"))
+      return
+    end
+
+    FileUtils.mkdir_p(data_dir)
+
+    1.upto(num_files) do |i|
+      File.write("#{data_dir}/c#{i}.rb", "class C#{i}\n""end\n")
+    end
+  end
+
+  prepare
+benchmark:
+  require: |
+    $:.push File.join(File.dirname(__FILE__), "bm_require.data")
+
+    1.upto(10000) do |i|
+      require "c#{i}"
+    end
+
+    $:.pop
+loop_count: 1
diff --git a/benchmark/require_thread.yml b/benchmark/require_thread.yml
new file mode 100644
index 0000000000..0c63257106
--- /dev/null
+++ b/benchmark/require_thread.yml
@@ -0,0 +1,40 @@
+prelude: |
+  require "fileutils"
+
+  def prepare
+    num_files = 10000
+
+    basename = File.dirname($0)
+    data_dir = File.join(basename, "bm_require.data")
+
+    # skip if all of files exists
+    if File.exist?(File.join(data_dir, "c#{num_files}.rb"))
+      return
+    end
+
+    FileUtils.mkdir_p(data_dir)
+
+    1.upto(num_files) do |i|
+      File.write("#{data_dir}/c#{i}.rb", "class C#{i}\n""end\n")
+    end
+  end
+
+  prepare
+benchmark:
+  require_thread: |
+    $:.push File.join(File.dirname(__FILE__), "bm_require.data")
+
+    i=0
+    t = Thread.new do
+      while true
+        i = i+1 # dummy loop
+      end
+    end
+
+    1.upto(100) do |i|
+      require "c#{i}"
+    end
+
+    $:.pop
+    t.kill
+loop_count: 1
diff --git a/benchmark/securerandom.rb b/benchmark/securerandom.rb
new file mode 100644
index 0000000000..a082ea6d5b
--- /dev/null
+++ b/benchmark/securerandom.rb
@@ -0,0 +1,5 @@
+require "securerandom"
+
+20_0000.times do
+  SecureRandom.random_number(100)
+end
diff --git a/benchmark/so_ackermann.rb b/benchmark/so_ackermann.rb
new file mode 100644
index 0000000000..4effa1ecaf
--- /dev/null
+++ b/benchmark/so_ackermann.rb
@@ -0,0 +1,19 @@
+#!/usr/bin/ruby
+# -*- Ruby -*-
+# $Id: ackermann-ruby.code,v 1.4 2004/11/13 07:40:41 bfulgham Exp $
+# http://www.bagley.org/~doug/shootout/
+
+def ack(m, n)
+    if m == 0 then
+        n + 1
+    elsif n == 0 then
+        ack(m - 1, 1)
+    else
+        ack(m - 1, ack(m, n - 1))
+    end
+end
+
+NUM = 9
+ack(3, NUM)
+
+
diff --git a/benchmark/so_array.rb b/benchmark/so_array.rb
new file mode 100644
index 0000000000..767e03db5f
--- /dev/null
+++ b/benchmark/so_array.rb
@@ -0,0 +1,23 @@
+#!/usr/bin/ruby
+# -*- Ruby -*-
+# $Id: ary-ruby.code,v 1.4 2004/11/13 07:41:27 bfulgham Exp $
+# http://www.bagley.org/~doug/shootout/
+# with help from Paul Brannan and Mark Hubbart
+
+n = 9000 # Integer(ARGV.shift || 1)
+
+x = Array.new(n)
+y = Array.new(n, 0)
+
+n.times{|bi|
+  x[bi] = bi + 1
+}
+
+(0 .. 999).each do |e|
+  (n-1).step(0,-1) do |bi|
+    y[bi] += x.at(bi)
+  end
+end
+# puts "#{y.first} #{y.last}"
+
+
diff --git a/benchmark/so_binary_trees.rb b/benchmark/so_binary_trees.rb
new file mode 100644
index 0000000000..b1693e4109
--- /dev/null
+++ b/benchmark/so_binary_trees.rb
@@ -0,0 +1,62 @@
+# The Computer Language Shootout Benchmarks
+# http://shootout.alioth.debian.org
+#
+# contributed by Jesse Millikan
+
+# disable output
+alias puts_orig puts
+def puts str
+  # disable puts
+end
+
+def item_check(tree)
+ if tree[0] == nil
+  tree[1]
+ else
+  tree[1] + item_check(tree[0]) - item_check(tree[2])
+ end
+end
+
+def bottom_up_tree(item, depth)
+ if depth > 0
+  item_item = 2 * item
+  depth -= 1
+  [bottom_up_tree(item_item - 1, depth), item, bottom_up_tree(item_item, depth)]
+ else
+  [nil, item, nil]
+ end
+end
+
+max_depth = 16 # ARGV[0].to_i
+min_depth = 4
+
+max_depth = min_depth + 2 if min_depth + 2 > max_depth
+
+stretch_depth = max_depth + 1
+stretch_tree = bottom_up_tree(0, stretch_depth)
+
+puts "stretch tree of depth #{stretch_depth}\t check: #{item_check(stretch_tree)}"
+stretch_tree = nil
+
+long_lived_tree = bottom_up_tree(0, max_depth)
+
+min_depth.step(max_depth + 1, 2) do |depth|
+ iterations = 2**(max_depth - depth + min_depth)
+
+ check = 0
+
+ for i in 1..iterations
+  temp_tree = bottom_up_tree(i, depth)
+  check += item_check(temp_tree)
+
+  temp_tree = bottom_up_tree(-i, depth)
+  check += item_check(temp_tree)
+ end
+
+ puts "#{iterations * 2}\t trees of depth #{depth}\t check: #{check}"
+end
+
+puts "long lived tree of depth #{max_depth}\t check: #{item_check(long_lived_tree)}"
+
+undef puts
+alias puts puts_orig
diff --git a/benchmark/so_concatenate.rb b/benchmark/so_concatenate.rb
new file mode 100644