9722 files changed, 2158185 insertions, 57321 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..bdb9011f25
--- /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: autoconf
+      - 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: ${{ secrets.SIMPLER_ALERTS_URL }} # ruby-lang slack: ruby/simpler-alerts-bot
+        if: failure() && github.event_name == 'push'
diff --git a/.github/workflows/check_branch.yml b/.github/workflows/check_branch.yml
new file mode 100644
index 0000000000..37cf3a9a8f
--- /dev/null
+++ b/.github/workflows/check_branch.yml
@@ -0,0 +1,22 @@
+# We bidirectionally synchronize github.com/ruby/ruby.git's master branch and
+# git.ruby-lang.org/ruby.git's master branch.
+# We can use a pull request's merge button only on the master branch.
+#
+# Therefore, we require to pass this "check_branch" on all protected branches
+# to prevent us from accidentally pushing commits to GitHub directly.
+#
+# Details: https://bugs.ruby-lang.org/issues/16094
+name: Pull Request
+on: [pull_request]
+jobs:
+  check_branch:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Check if branch is master
+        run: |
+          if [ "$BASE_REF" != master ]; then
+            echo "Only master branch accepts a pull request, but it's '$BASE_REF'."
+            exit 1
+          fi
+        env:
+          BASE_REF: ${{ github.base_ref }}
diff --git a/.github/workflows/check_dependencies.yml b/.github/workflows/check_dependencies.yml
new file mode 100644
index 0000000000..c878caddeb
--- /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: ${{ matrix.os }}
+    if: "!contains(github.event.head_commit.message, '[ci skip]')"
+    steps:
+      - name: Install libraries
+        run: |
+          set -x
+          sudo apt-get update -q || :
+          sudo apt-get install --no-install-recommends -q -y build-essential libssl-dev libyaml-dev libreadline6-dev zlib1g-dev libncurses5-dev libffi-dev libgdbm-dev bison autoconf ruby
+        if: "contains(matrix.os, 'ubuntu')"
+      - name: Install libraries
+        run: |
+          brew upgrade
+          brew install gdbm gmp libffi openssl@1.1 zlib autoconf automake libtool readline
+        if: "contains(matrix.os, 'macos')"
+      - name: git config
+        run: |
+          git config --global advice.detachedHead 0
+      - uses: actions/checkout@v2
+      - run: autoconf
+      - name: Run configure
+        run: ./configure -C --disable-install-doc --disable-rubygems --with-gcc 'optflags=-O0' 'debugflags=-save-temps=obj -g'
+      - run: make all golf
+      - run: ruby tool/update-deps --fix
+      - run: git diff --no-ext-diff --ignore-submodules --exit-code
+      - uses: k0kubun/action-slack@v2.0.0
+        with:
+          payload: |
+            {
+              "ci": "GitHub Actions",
+              "env": "${{ 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..2f4bbc7093
--- /dev/null
+++ b/.github/workflows/check_misc.yml
@@ -0,0 +1,17 @@
+name: Miscellaneous checks
+on: [push, pull_request]
+
+jobs:
+  checks:
+    runs-on: ubuntu-latest
+    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..9fbabd35c6
--- /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-latest and windows-latest
+    runs-on: ubuntu-latest
+
+    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@v1
+      with:
+        languages: cpp
+        config-file: ./.github/codeql/codeql-config.yml
+
+    - name: Autobuild
+      uses: github/codeql-action/autobuild@v1
+
+    - name: Perform CodeQL Analysis
+      uses: github/codeql-action/analyze@v1
diff --git a/.github/workflows/compilers.yml b/.github/workflows/compilers.yml
new file mode 100644
index 0000000000..532e4589e2
--- /dev/null
+++ b/.github/workflows/compilers.yml
@@ -0,0 +1,216 @@
+name: Compilations
+
+on: [push, pull_request]
+
+# Github actions does not support YAML anchors.  This creative use of
+# environment variables (plus the "echo ::set-env" hack) is to reroute that
+# restriction.
+env:
+  default_cc: clang-11
+  append_cc: ''
+  crosshost: ''
+
+  # -O1 is faster than -O3 in our tests... Majority of time are consumed trying
+  # to optimize binaries.  Also Github Actions runs on a relatively modern CPU
+  # 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-10,    value: gcc-10 }
+#         - { key: default_cc, name: gcc-9,     value: gcc-9 }
+#         - { key: default_cc, name: gcc-8,     value: gcc-8 }
+#         - { key: default_cc, name: gcc-7,     value: gcc-7 }
+#         - { key: default_cc, name: gcc-6,     value: gcc-6 }
+#         - { key: default_cc, name: gcc-5,     value: gcc-5 }
+          - { key: default_cc, name: gcc-4.8,   value: gcc-4.8 }
+          - { key: default_cc, name: clang-12,  value: clang-12 }
+#         - { key: default_cc, name: clang-11,  value: clang-11 }
+#         - { key: default_cc, name: clang-10,  value: clang-10 }
+#         - { key: default_cc, name: clang-9,   value: clang-9 }
+#         - { key: default_cc, name: clang-8,   value: clang-8 }
+#         - { key: default_cc, name: clang-7,   value: clang-7 }
+#         - { key: default_cc, name: clang-6.0, value: clang-6.0 }
+#         - { key: default_cc, name: clang-5.0, value: clang-5.0 }
+#         - { key: default_cc, name: clang-4.0, value: clang-4.0 }
+          - { key: default_cc, name: clang-3.9, value: clang-3.9 }
+
+          - { key: crosshost, name: aarch64-linux-gnu,     value: aarch64-linux-gnu }
+#         - { 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 }
+          - { key: crosshost, name: s390x-linux-gnu,       value: s390x-linux-gnu }
+          - { key: crosshost, name: x86_64-w64-mingw32,    value: x86_64-w64-mingw32 }
+
+          - { 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' }
+
+          - { 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' }
+
+    name: ${{ matrix.entry.name }}
+    runs-on: ubuntu-latest
+    container: ghcr.io/ruby/ruby-ci-image:latest
+    if: "!contains(github.event.head_commit.message, '[ci skip]')"
+    steps:
+      - run: mkdir build
+        working-directory:
+      - name: setenv
+        run: |
+          echo "${{ matrix.entry.key }}=${{ matrix.entry.value }}" >> $GITHUB_ENV
+          echo "make=make -sj$((1 + $(nproc --all)))" >> $GITHUB_ENV
+      - uses: actions/checkout@v2
+        with:
+          path: src
+      - run: autoconf
+        working-directory: src
+      - name: Run configure
+        run: |
+          if [ -n "${crosshost}" ]; then
+            ../src/configure -C \
+              ${default_configure} \
+              ${append_configure} \
+              --host="${crosshost}"
+          else
+            ../src/configure -C \
+              ${default_configure} \
+              ${append_configure} \
+              --with-gcc="${default_cc} ${append_cc}"
+          fi
+      - run: $make extract-extlibs
+      - run: $make incs
+      - run: $make
+      - run: $make test
+      - run: $make install
+        if: "matrix.entry.name == '-O3'"
+      - run: /usr/local/bin/gem install --no-doc timezone tzinfo
+        if: "matrix.entry.name == '-O3'"
+      - run: $make test-tool
+        if: "matrix.entry.name == '-O3'"
+      - run: $make test-all TESTS='-- ruby -ext-'
+        if: "matrix.entry.name == '-O3'"
+      - run: $make test-spec
+        if: "matrix.entry.name == '-O3'"
+
+      - uses: k0kubun/action-slack@v2.0.0
+        with:
+          payload: |
+            {
+              "ci": "GitHub Actions",
+              "env": "${{ 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..f0355258f1
--- /dev/null
+++ b/.github/workflows/macos.yml
@@ -0,0 +1,64 @@
+name: macOS
+on: [push, pull_request]
+jobs:
+  make:
+    runs-on: macos-latest
+    strategy:
+      matrix:
+        test_task: [ "check", "test-bundler-parallel", "test-bundled-gems", "leaked-globals" ]
+      fail-fast: false
+    env:
+      GITPULLOPTIONS: --no-tags origin ${{github.ref}}
+    if: "!contains(github.event.head_commit.message, '[ci skip]')"
+    steps:
+      - run: mkdir build
+        working-directory:
+      - name: Disable Firewall
+        run: |
+          sudo /usr/libexec/ApplicationFirewall/socketfilterfw --setglobalstate off
+          sudo /usr/libexec/ApplicationFirewall/socketfilterfw --getglobalstate
+      - name: git config
+        run: |
+          git config --global advice.detachedHead 0
+      - uses: actions/checkout@v2
+        with:
+          path: src
+      - name: Install libraries
+        run: |
+          export WAITS='5 60'
+          tool/travis_retry.sh brew upgrade
+          tool/travis_retry.sh brew install gdbm gmp libffi openssl@1.1 zlib autoconf automake libtool readline
+        working-directory: src
+      - name: Set ENV
+        run: |
+          echo "JOBS=-j$((1 + $(sysctl -n hw.activecpu)))" >> $GITHUB_ENV
+      - run: autoconf
+        working-directory: src
+      - name: Run configure
+        run: ../src/configure -C --disable-install-doc --with-openssl-dir=$(brew --prefix openssl@1.1) --with-readline-dir=$(brew --prefix readline)
+      - run: make $JOBS incs
+      - run: make $JOBS
+      - run: make 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..c0366f2942
--- /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-2019
+    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: MSP-Greg/setup-ruby-pkgs@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: misc setup, autoreconf
+        run: |
+          mkdir install
+          mkdir temp
+          cd src
+          sh -c "autoreconf -fi"
+        working-directory:
+
+      - 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=/install $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-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 }} / ${{ matrix.test_task }}",
+              "url": "https://github.com/${{ 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..68889ecf3d
--- /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", "--jit-wait" ]
+      fail-fast: false
+    runs-on: ubuntu-latest
+    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 $d; done' || :
+      - name: Set ENV
+        run: |
+          echo "JOBS=-j$((1 + $(nproc --all)))" >> $GITHUB_ENV
+      - run: autoconf
+        working-directory: src
+      - name: Run configure
+        run: ../src/configure -C --disable-install-doc
+      - run: make $JOBS incs
+      - run: make $JOBS
+      - run: sudo make $JOBS -s install
+      - run: sudo apt-get install gdb # used by test / test-all failure
+      - name: Run test
+        run: |
+          ulimit -c unlimited
+          make $JOBS -s test RUN_OPTS="$RUN_OPTS"
+        timeout-minutes: 60
+      - name: Run test-all
+        run: |
+          ulimit -c unlimited
+          make $JOBS -s test-all RUN_OPTS="$RUN_OPTS"
+        timeout-minutes: 60
+      - name: Run test-spec
+        run: |
+          ulimit -c unlimited
+          make $JOBS -s test-spec RUN_OPTS="$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..75b7d1220a
--- /dev/null
+++ b/.github/workflows/spec_guards.yml
@@ -0,0 +1,39 @@
+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
+
+    steps:
+      - uses: actions/checkout@v2
+      - uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: ${{ matrix.ruby }}
+          bundler: none
+      - run: ruby ../mspec/bin/mspec
+        working-directory: spec/ruby
+      - uses: k0kubun/action-slack@v2.0.0
+        with:
+          payload: |
+            {
+              "ci": "GitHub Actions",
+              "env": "${{ 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..fe517d2750
--- /dev/null
+++ b/.github/workflows/ubuntu.yml
@@ -0,0 +1,89 @@
+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", "leaked-globals" ]
+        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
+          - test_task: leaked-globals
+            os: ubuntu-16.04
+          - os: ubuntu-16.04
+            debug: -DRUBY_DEBUG
+          - test_task: "test-all TESTS=--repeat-count=2"
+            debug: -DRUBY_DEBUG
+          - test_task: leaked-globals
+            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)))" >> $GITHUB_ENV
+      - run: autoconf
+        working-directory: src
+      - name: Run configure
+        run: ../src/configure -C --disable-install-doc cppflags=${{ matrix.debug }}
+      - run: make $JOBS incs
+      - run: make $JOBS
+      - run: make 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
new file mode 100644
index 0000000000..48e5a96de7
--- /dev/null
+++ b/COPYING
@@ -0,0 +1,56 @@
+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:
+
+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 binaries 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 binary form,
+   provided that you do at least ONE of the following:
+
+   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.
+
+   b. accompany the distribution with the machine-readable source of
+      the software.
+
+   c. give non-standard binaries 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 these terms.
+
+   For the list of those files and their copying conditions, see the
+   file LEGAL.
+
+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.
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 9fda8fc114..0000000000
--- a/ChangeLog
+++ /dev/null
@@ -1,4208 +0,0 @@
-Fri Oct  3 10:51:10 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* version 1.0-971003
-
-	* eval.c (ruby_options): f_require() called too early.
-
-	* eval.c (rb_provide): module extentions should always be `.o'.
-
-Thu Oct  2 17:59:18 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* ext/marshal/marshal.c (r_object): remove temporal regist for
- 	  structs. (caused problem if structs form cycles.)
-
-	* version 1.0-971002
-
-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>
-
-	* 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'.
-
-Tue Sep 30 14:51:07 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* version 1.0-970930
-
-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.
-
-Mon Sep 29 13:37:58 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* ruby.c (forbid_setid): forbid some options in suid mode.
-
-Mon Sep 27 09:53:48 1997  EGUCHI Matsumoto  <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.
-
-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    <matz@netlab.co.jp>
-
-	* version 1.0-970919
-
-	* 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 1.0-970911
-
-	* 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>
-
-	* version 1.0-970910
-
-	* 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.
-
-Tue Sep  9 16:27:14 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* version 1.0-970909
-
-	* error.c (set_syserr): some system has error code that is bigger
-	  than sys_nerr. grrr.
-
-Wed Sep  3 18:11:00 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* version 1.0-970903
-
-	* eval.c (f_load): expand path if fname begins with `~'.
-
-Mon Sep  1 13:42:48 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* eval.c (rb_call): alias occured in the module body caused SEGV.
-
-Fri Aug 29 11:10:21 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* 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>
-
-	* parse.y (yylex): revised `=begin' skip code.
-
-	* eval.c (is_defined): separated from rb_eval().
-
-Wed Aug 27 11:32:42 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* 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 $@ set.
-
-	* object.c (Init_Object): superclass()'s method argument setting
- 	  was wrong again.
-
-Mon Aug 25 11:53:11 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* sample/ruby-mode.el (ruby-parse-region): auto-indent now
- 	  supports "\\" in the strings.
-
-	* struct.c (struct_getmember): new API to get member value from C
-	  language side.
-
-Fri Aug 22 14:26:40 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* eval.c (error_print): modified exception print format.
-
-Thu Aug 21 16:10:58 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* sample/ruby-mode.el (ruby-calculate-indent): wrong indent level
-	  calculated with keyword operators.
-
-Thu Aug 21 11:55:41 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* version 1.0-970821
-
-Thu Aug 21 11:36:58 1997  WATANABE Hirofumi  <watanabe@ase.ptg.sony.co.jp>
-
-	* parse.y (arg): ary[0] += 1 cause SEGV
-
-Wed Aug 20 14:24:42 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* version 1.0-970820
-
-	* eval.c (rb_call): infinite loop bug
-
-Tue Aug 19 00:15:38 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* version 1.0-970819
-
-	* eval.c (rb_call): did not raise ArgumentError if too many
- 	  arguments more than optional arguments (without rest arg).
-
-	* eval.c (rb_eval): did not work well for op_asgn2 (attribute
-	  self assignment).
-
-Mon Aug 18 09:25:56 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* object.c (inspect_i): did not display T_DATA instance variables.
-
-	* parse.y: provides more accurate line number information.
-
-	* eval.c (thread_value): include value's backtrace information in
-	  the variable `$@'. 
-
-	* eval.c (f_abort): print backtrace and exit.
-
-Sat Aug 16 00:17:44 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* 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.
-
-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.
-
-Tue Aug 12 16:02:18 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* variable.c: option variables: $-0, $-p(readonly), $-v,
-	  $-I(load_path), $-a(readonly), $-K, $-d, $-F, $-i, $-l. 
-
-	* parse.y (yylex): ignore rd (ruby document) in the code.
-
-Mon Aug 11 12:37:58 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* re.c (Init_Regexp): $-K as alias to the $KCODE.
-
-	* io.c (Init_IO): new virtual variable $-i for the value of -i
- 	  option.
-
-	* enum.c (Init_Enumerable): include? as alias of member?
-
-Fri Aug  8 11:16:50 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* io.c (io_foreach): now the record separator can be specified.
-
-	* io.c (io_s_readlines): new method to read in whole file (or
- 	  command output) from path.
-
-	* ext/socket/socket.c (Init_socket): recvfrom did not work.
-
-	* ext/socket/socket.c (sock_send): forgot to check nil for false
-	  value.
-
-Thu Aug  7 11:40:01 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* object.c (Init_Object): remove private_attr/public_attr.
-
-Wed Aug  6 14:21:36 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* object.c (mod_attr): forgot to check nil for false value.
-
-Mon Aug  4 11:50:28 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* variable.c (rb_class_path): scan class constants for anonymous
-	  classes/modules to make up pathes.
-
-Wed Jul 30 08:45:12 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* eval.c (rb_eval): stop to cache const value in nodes.
-
-Sat Jul 26 03:17:22 1997  WATANABE Hirofumi  <watanabe@ase.ptg.sony.co.jp>
-
-	* numeric.c (flo_to_s): wrong .0 at end.
-
-Sat Jul 26 00:36:36 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* eval.c (error_print): always print exception type in the
- 	  toplevel exception handler.
-
-	* string.c (str_hash): wrong hash value.
-
-Thu Jul 24 11:05:51 1997  Yukihiro Matsumoto  <matz@netlab.co.jp>
-
-	* string.c (uscore_get): proper error message for unset $_.
-
-Wed Jul 23 09:56:55 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* object.c (obj_methods): returns list of method names of the
-	  specified object.
-
-	* class.c (mod_instance_methods): returns list of method names of 
-	  the class instnace.
-
-Fri Jul 11 22:38:55 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* object.c (class_superclass): returns class's superclass
- 	  itself. (1.1)
-
-	* object.c (obj_type): returns object's class itself. (1.1)
-
-	* class.c (mod_included_modules): list included modules.
-
-	* object.c (class_superclass): raises error for Object.
-
-Thu Jul  3 09:54:02 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* eval.c (SETUP_ARGS): save source position, remove nd_line().
-
-	* eval.c (rb_call): replace modulo by bit-masking.
-
-	* eval.c (POP_SCOPE): force recycle scope object to reduce gc rate.
-
-	* gc.c (obj_free): aboid calling run_final() when no finalizer is set.
-
-	* eval.c (PUSH_VARS): do not allocate the dynamic scope's end-mark
-	  object.
-
-Wed Jul  2 14:25:07 1997  KIMURA Koichi  <kkimura@pure.cpdc.canon.co.jp>
-
-	* Native mswin32 support.
-
-Tue Jul  1 09:59:00 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* version 1.0-970701
-
-	* parse.y (mrhs): allow rest-star(*) in right hand side.
-
-Tue Jun 24 19:04:31 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* version 1.0-970624
-
-Sat Jun 20 22:22:51 1997  Michio "Karl" Jinbo  <karl@marcer.nagaokaut.ac.jp>
-
-	* eval.c: freebsd 3.0 <sys/select.h> support.
-
-Fri Jun 20 01:24:45 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* version 1.0-970620
-
-	* gc.c: eliminate uninitilalized field of Hash, Array etc., to
-	  avoid dumping core.
-
-Thu Jun 19 01:29:44 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* version 1.0-970619
-
-	* string.c (str_split_method): wrong limit.
-
-Sat Jun 14 01:54:16 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* class.c (rb_singleton_class): no singleton for special
-	  constants (now raises exception).
-
-	* eval.c (ruby_init): cbase in TOPLEVEL_BINDING need to be
-	  initialized.
-
-Sat Jun 14 01:01:16 1997  maeda shugo  <shugo@po.aianet.ne.jp>
-
-	* array.c (sort_2): wrong comparison.
-
-Sat Jun 14 00:53:44 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* hash.c (hash_foreach): safe iteration.
-
-Fri Jun 13 14:04:56 1997  Michio "Karl" Jinbo  <karl@marcer.nagaokaut.ac.jp>
-
-	* configure.in: -Bshareable option for netbsd.
-
-Fri Jun 13 01:16:22 1997  WATANABE Hirofumi  <watanabe@ase.ptg.sony.co.jp>
-
-	* io.c (pipe_open): call io_unbuffered() only for writable pipes.
-
-Thu Jun 12 01:14:15 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* version 1.0-970612
-
-	* ext/socket/socket.c (sock_new): use io_unbuffered().
-
-	* ext/marshal/marshal.c (w_long): compact long format, which
-	  supports 64 bit architectures (unless longs are >32 bit size).
-
-	* ext/marshal/marshal.c: allows recursive data for marshaling.
-
-	* parse.y (rb_intern): raise exception for non-internable string.
-
-	* ext/marshal/marshal.c (marshal_load): allows direct loading from
- 	  strings.
-
-	* ext/marshal/marshal.c (marshal_dump): allows direct dump to strings.
-
-	* ext/marshal/marshal.c (marshal_dump): interface changed.
-
-Wed Jun 11 18:26:00 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* gc.c (rb_newobj): remove needless memset().
-
-Mon Jun  9 13:03:43 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* eval.c (rb_eval): reduce condition checks from while/until loop.
-
-	* eval.c (rb_eval): wrong jump point for `next'.
-
-Fri Jun  6 11:47:39 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* ruby.c (ruby_set_argv): initialize dln_argv0 for dln_a_out.
-
-	* ext/socket/socket.c (open_unix): display path name for exceptions.
-
-	* ruby.c (proc_options): option -S did not work well.
-
-Fri May 30 02:14:44 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* version 1.0-970530
-
-	* eval.c (eval): set $! properly if exception raised in eval().
-
-	* io.c (io_write): now handles non T_FILE object.
-
-	* io.c (io_defset): $< can be anything which has `write' method.
-
-Thu May 29 15:40:22 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* eval.c (eval): $@ is always an array (not string).
-
-	* pack.c (pack_unpack): avoid corrupting memory for unexpected
-	  input strings.
-
-Wed May 28 12:46:13 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* version 1.0-970528
-
-	* process.c (rb_waitpid): do not block other threads.
-
-Tue May 27 12:02:31 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* eval.c (ruby_init): split initialize and processing command line
-	  options.
-
-	* ruby.c (ruby_options): ruby_init(0, 0, envp) dumps core.
-
-Tue May 20 18:59:45 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* variable.c (rb_ivar_set): invalid instance variable access for
-	  built-in object raises TypeError.
-
-Fri May 16 17:32:21 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* version 1.0-970516
-
-	* dir.c (push_globs): was freeing non heap pointer.
-
-	* gc.c: remove some duplicated prototypes.
-
-	* ext/kconv/kconv.c: fix prototypes.
-
-Fri May  9 11:38:59 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* version 1.0-970509
-
-	* gc.c (obj_free): avoid free(NULL).
-
-	* eval.c (rb_check_safe_str): argument missing for TypeError().
-
-Thu May  8 01:14:28 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* file.c (file_s_dirname): need to return "." for path without
-	  slashes.
-
-Wed May  7 19:18:48 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* process.c (f_fork): child processe does not inherit parent's
- 	  itimer setting on linux.  call setitimer() again in the child
-	  process.
-
-Sat May  3 02:49:43 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* ext/curses/curses.c: modified for portability and add to the
- 	  standard distribution.
-
-Wed Apr 30 00:34:00 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* file.c (file_s_size): returns 0 for empty files (not FALSE).
-
-Fri Apr 25 02:17:50 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* version 1.0-970425
-
-	* eval.c (f_load): free unused name-table.
-
-	* eval.c (f_load): copy local variable name-table.
-
-	* gc.c (obj_free): avoid free(NULL).
-
-	* eval.c (rb_eval): forgot to make link from the scope object to
-	  NODE_SCOPE.  It may crash the interpreter.
-
-Thu Apr 24 00:35:09 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* random.c (f_srand): save old seed anyway.  srand() returns no
- 	  value on some systems.
-
-	* gc.c (obj_free): avoid double free of the local variable name
-	  table.
-
-	* parse.y (top_local_setup): modify realloc to handle offset.
-
-Tue Apr 22 12:58:26 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* version 1.0-970422
-
-Thu Apr 17 00:40:51 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* configure.in (rb_cv_bsdpgrp): proper check for BSD
-	  setpgrp/setpgrp. 
-
-Wed Apr 16 16:14:02 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* eval.c (proc_call): proc called in other thread must be orphan.
-
-Tue Apr 15 10:46:31 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* version 1.0-970415
-
-	* gc.c (obj_free): NODE_SCOPE marked from SCOPE object.
-
-	* gc.c (gc_mark): some nodes marked wrong.
-
-	* process.c (proc_getpgrp): wrong argument
-
-Fri Apr 14 18:32:42 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* version 1.0-970414
-
-Fri Apr 12 01:20:12 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* ruby.h: String pointer changed to unsigned char.
-
-Fri Apr 11 10:27:29 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* version 1.0-970411
-
-	* Makefile.in: create libruby.a before linking ruby.
-
-	* string.c (str_strip_bang): >0x80 characters for isspace().
-
-	* eval.c (proc_call): set safe-level temporally
-
-	* eval.c (proc_s_new): save safe-level in the proc context.
-
-	* eval.c (rb_eval): no class/module extention in safe mode.
-
-Thu Apr 10 02:10:41 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* gc.c (gc_mark): remove some pointer checks for speeding up.
-
-	* ruby.c (ruby_options): set $0 temporally for -r option.
-
-	* eval.c: built-in security feature.
-
-	* gc.c (gc_sweep): do not free nodes during compile.
-
-	* parse.y (yycompile): set flag when compiling.
-
-Wed Apr  9 10:19:02 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* ruby.c: forgot to include <ctype.h> for isspace().
-
-	* file.c: provide S_ISREG for some platforms.
-
-	* io.c (Init_IO): added some $< operations.
-
-	* lib/ping.rb: check host upness using TCP echo.
-
-Tue Apr  8 00:10:15 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* io.c (arg_read): bug with 0 length input.
-
-Mon Apr  7 11:36:16 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* ext/fcntl/fcntl.c: module for fcntl constants.
-
-	* eval.c (rb_alias): bug when original was an alias.
-
-	* parse.y (primary): syntax to access singleton class.
-
-	* eval.c (mod_public_method): method's to specify visibitily of
-	  the class methods.  make_method_{public,private} removed.
-
-Fri Apr  4 21:43:57 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* version 1.0-970404
-
-	* gc.c (obj_free): finalizer added for experiment.
-
-Thu Apr  3 02:12:31 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* eval.c (thread_schedule): make Fatal rise on main_thread on
-	  deadlocks.
-
-	* eval.c (thread_join): raise ThreadError instead of Fatal, in
-	  case of deadlock.
-
-	* regex.c (re_compile_fastmap): uninitialized local variable.
-
-	* parse.y (parse_regx): new option //[nes] to specify character
-	  code for regexp literals.  Last specified code option is valid.
-
-	* re.c (reg_s_new): addtional 3rd argument to specify compiled
- 	  regexp's character code.
-
-	* re.c (reg_new_1): regexp character code can be specified for
-	  each regexp object.
-
-Wed Apr  2 14:51:06 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* eval.c (thread_create): handle uncaught throw.
-
-	* eval.c (thread_create): halt on some deadlock conditions.
-
-	* regex.c (is_in_list): wrong result for non-mbc higher-byte
-	  characters. 
-
-	* regex.c (re_match): wrong skip for multi-byte characters.
-
-	* regex.c (re_compile_fastmap): wrong fastmap in non-mbc mode.
-
-	* hash.c (Init_Hash): hash compatible features added to ENV.
-
-Tue Apr  1 15:24:06 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* eval.c (obj_extend): remove Object#extend as an iterator which
- 	  is in experimental state, since it unveils internal singleton
- 	  classes.
-
-Mon Mar 31 14:29:39 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* version 1.0-970331
-
-Sun Mar 30 19:40:57 1997  WATANABE Hirofumi  <watanabe@ase.ptg.sony.co.jp>
-
-	* parse.y (terms): avoided win32 gcc's optimization bug.
-
-Sat Mar 29 11:21:58 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* struct.c (make_struct): St[val,..] creates new structure.
-
-Fri Mar 28 11:24:51 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* eval.c (obj_make_private): new method make_method_{public,private}
-	  to change visibility of singleton methods.
-
-	* regex.c (re_compile_pattern): enables numeric literal >= 0x80 in 
-	  the character class.
-
-	* regex.c (re_compile_pattern): enabled numeric literal >= 0x80,
-	  in multibyte mode.
-
-	* regex.c (re_compile_fastmap): modified exantn and charset(_not)
-	  to set fastmap for higher bytes properly.
-
-	* regex.c (is_in_list): now matches numeric literals.
-
-Thu Mar 27 13:34:20 1997  WATANABE Hirofumi  <watanabe@ase.ptg.sony.co.jp>
-
-	* pack.c (pack_unpack): extra null byte after unpacked string.
-
-Wed Mar 26 15:20:34 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* regex.c (re_compile_pattern): register numbers must be fit in a
- 	  byte (0 <= regnum <= 0xff).
-
-	* regex.c (re_compile_fastmap): forgot to set mbchar map for
- 	  charset_not if RE_MBCTYPE is on.
-
-	* regex.c (re_compile_pattern): set list bits for multi-byte
-	  characters for \W, \S, \D in range expression.
-
-	* object.c (obj_is_kind_of): defined that nil itself is kind of
- 	  nil.  TRUE is kind of TRUE, FALSE is kind of FALSE likewise.
-  	  This change makes `obj.kind_of?(eval(obj.type))' always true.
-
-Tue Mar 25 14:08:43 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* lib/English.rb: provides nicer English alias for the variables.
-
-	* parse.y (expr): alias $var1 $var2 makes alias of the global
-	  variable. 
-
-Mon Mar 24 18:23:20 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* version 1.0-970324
-
-Thu Mar 20 22:04:59 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* eval.c (mod_modfunc): forget to clear method cache.
-
-Wed Mar 19 17:06:55 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* parse.y (program): set methods' default private/public status
-	  correctly under eval().
-
-	* eval.c (eval): set the_class correctly while evaluating string.
-
-Tue Mar 18 12:23:53 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* eval.c (eval): yield can be called from eval().
-
-	* version 1.0-970318
-
-	* parse.y (program): regexp in condition expression should do
-	  matching operation with $_.
-
-	* re.c (reg_regsub): wrong substitution.
-
-Fri Mar 14 14:36:28 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* hash.c (hash_invert): returns value to key mapping of the
-	  associative array.
-
-	* ext/socket/extconf.rb: set environment variable SOCKS_SERVER to
-	  compile with libsocks.a.
-
-	* ext/socket/socket.c (socks_s_open): SOCKSsocket class to access
-	  internet via SOCKS library.
-
-	* sprintf.c (f_sprintf): unsigned formats display leading double
- 	  dots for imaginary sequence of signed bit to the left.
-
-	* sprintf.c (f_sprintf): correct width and precision formatting
-	  for big integers.
-
-	* parse.y (yylex): enables negative hex/octal numbers and `_' in
-	  non-decimal numbers.
-
-	* sprintf.c (f_sprintf): %u added for unsigned decimal format.
-
-Thu Mar 13 10:24:27 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* sprintf.c (f_sprintf): wrong output for bignums.
-
-	* array.c (ary_reverse_each): iterates in reverse order.
-
-	* pack.c (pack_unpack): L unpacked signed long.
-
-	* io.c (f_backquote): now returns an empty string for no output.
-
-Wed Mar 12 10:20:30 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* ext/socks/socks.c: socket module with socks library.
-
-Mon Mar 10 20:44:22 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* re.c (reg_regsub): \& for substitution.  \`, \', and \+ are
-	  avaiable also.
-
-Thu Mar  6 01:47:03 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* version 1.0-970306
-
-	* sample/rubydb.el (gud): ruby debugger emacs interface
-
-	* lib/debug.rb: ruby debugger
-
-	* parse.y (exprs): more accurate line number display.
-
-Wed Mar  5 21:31:46 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* version 1.0-970305
-
-Tue Mar  4 12:28:32 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* ruby.c (proc_options): search through RUBYPATH and PATH for
-	  option -S.
-
-Mon Mar  3 22:44:55 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* eval.c (thread_status): returns nil for exception terminated
-	  threads. 
-
-	* eval.c (thread_value): re-raise exceptions.
-
-Sat Mar  1 00:59:47 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* eval.c (rb_eval): restore $! value after rescue clause, to 
-	  re-raise exceptions correctly.
-
-Fri Feb 28 16:43:38 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* version 1.0-970228
-
-Thu Feb 27 11:23:41 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* eval.c (rb_yield_0): redo raises exception
-
-	* eval.c (thread_schedule): bug in interrupt handling by rescue.
-
-Wed Feb 26 00:55:36 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* eval.c (eval): forgot to restore dynamic local variable
-	  bindings.
-
-Tue Feb 25 11:22:08 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* ext/aix_ld.rb: AIX dynamic load support (not tested).
-
-	* eval.c (rb_eval): wrong return value for defined? super.
-
-	* error.c (exception): more error check.
-
-	* re.c (reg_regsub): wrong substitution when sub expanded to null
- 	  string.
-
-Fri Feb 21 13:01:47 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* version 1.0-970221
-
-	* eval.c (f_require): volatile added.  register variable was
- 	  recycled, so that GC did not mark that variable.
-
-	* object.c (Init_Object): forget to mark main object (was mostly
-	  ok, but made trouble with early GC.)
-
-Thu Feb 20 11:50:50 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* version 1.0-970220
-
-Thu Feb 20 11:25:50 1997  Yasuo OHBA  <jammy@shljapan.co.jp>
-
-	* lib/date.rb: update
-
-Thu Feb 20 08:25:57 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* parse.y (yylex): forgot tokfix() before rb_intern().
-
-	* lib/tk.rb (TkVariable): give up using trace_var.
-
-Wed Feb 19 00:24:35 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* version 1.0-970219
-
-	* pack.c (pack_pack): packed by null for A specifier. must be
-	  space filled.
-
-	* pack.c (pack_unpack): bug in skipping spaces
-
-	* gc.c (xmalloc): garbage collect for every 4 Meg. allocation.
-
-	* string.c (str_split_method): limit worked wrong way.
-
-	* io.c (io_gets_method): misunderstand 0xff in binary files when
-	  $/ == nil.
-
-	* re.c (reg_regsub): re-implement.
-
-	* ext/socket/socket.c (thread_connect): remove O_NONBLOCK, which
-	  is not defined on some platform like NeXT.
-
-Mon Feb 17 13:08:30 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* version 1.0-970217
-
-	* object.c (mod_eqq): === extended for subclass check (to use case
-	  as typecase).
-
-Sat Feb 15 02:07:22 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* regex.c (re_compile_pattern): wrong match backref at end of pattern.
-
-	* io.c (arg_read): now works beyond end of file.
-
-Thu Feb 13 16:21:24 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* parse.y (expr): return/yield now accept normal argument format.
-
-	* parse.y (yylex): a star in `yield *x' must not be multiplication 
-	  operator.
-
-Wed Feb 12 15:06:44 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* time.c (time_plus): bug in simple addition.
-
-	* eval.c (thread_raise): raise exceptions from outside.
-
-	* eval.c (Init_Thread): Thread#alive? -- alias for Thread#status.
-
-Mon Feb 10 00:38:55 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* ruby.h (Data_Make_Struct): rename macros.
-
-Sun Feb  8 11:48:13 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* io.c (f_syscall): argument offset was wrong.
-
-Fri Feb  7 18:01:17 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* version 1.0-970207
-
-	* eval.c: add volatiles to avoid variable crobbering by longjmp().
-
-	* eval.c (f_raise): 1st argument can be the GlobalExit object now.
-
-	* array.c (ary_unshift): no longer accept more than 2 args.
-
-	* eval.c (f_raise): bug if 2nd argument is the exception.
-
-Tue Feb  4 00:37:29 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* version 1.0-970204
-
-	* eval.c (eval): check compile errors by nerrs.
-
-	* eval.c (rb_eval): check syntax error by nerrs, not by the return
- 	  value, which may be NULL.
-
-	* eval.c (compile): Do not clear errinfo.
-
-Mon Feb  3 10:13:06 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* eval.c (obj_extend): move real inclusion to Module#extend_object 
-	  to allow redfinition.
-
-	* object.c (Init_Object): Kernel class is now Module. Object class 
-	  became the true root class.
-
-	* object.c (obj_inspect): remove useless buffer.
-
-	* hash.c (any_cmp): disable interrupts and context switching.
-
-	* st.c: remove ALLOW_INTS to disable interrupt during operations.
-
-Fri Jan 31 22:10:08 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* hash.c (hash_rehash): re-register all key-value.
-
-Thu Jan 30 02:14:49 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* io.c (io_reopen): re-implement according to clone() way.
-
-	* io.c (io_clone): copy IO object.
-
-	* struct.c (struct_eql): compare elements by eql?.
-
-	* io.c (io_mode_flags): detect "rb", "wb" etc.
-
-	* io.h (FMODE_BINMODE): added.
-
-	* ext/socket/socket.c (Init_socket): undef BasicSocket.new
-
-	* file.c (Init_File): File.new(path[,mode])
-
-	* io.c (Init_IO): IO.new(fd[,mode])
-
-	* eval.c (rb_method_boundp): forgot to enable priv argument.
-
-	* object.c (Init_Object): remove `=~' from Kernel class.
-
-	* ext/socket/socket.c (open_inet): initialize sockaddr before
-	  calling bind(2).
-
-	* sample/ruby-mode.el (ruby-calculate-indent): skip comment lines
-
-Wed Jan 29 18:43:22 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* eval.c (Init_Thread): DEFER_INTS during initializing threads.
-
-	* hash.c (Init_Hash): Hash#eql? checks for object identity.
-
-	* eval.c (thread_set_critical): wrong value assigned.
-
-Mon Jan 27 16:10:51 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* io.c (io_print): remove print_on().
-
-	* eval.c (f_missing): proper error message for undefined method
-	  without argument
-
-Sat Jan 25 23:32:32 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* string.c (str_sub_s): false alert - sub() does not modify string.
-
-	* array.c (ary_times): negative multiplication detected
-
-	* string.c (str_times): negative multiplication detected
-
-Fri Jan 24 10:51:39 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* time.c (time_arg): month -> 0 == "jan" == "1" == "01", little bit
-	  confusing but wanted to conform japanese style.
-
-	* version 1.0-970124
-
-Fri Jan 24 09:52:49 1997  WATANABE Hirofumi  <watanabe@ase.ptg.sony.co.jp>
-
-	* util.c (_fixpath): supports SJIS filenames on DJGPP.
-
-Thu Jan 23 16:52:06 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* README.EXT: update. partially translated into English.
-
-	* ext/extmk.rb.in: inherit $LDFLAGS to the final link.
-
-	* ext/socket/socket.c (Init_socket): add various constants.
-
-Mon Jan 23 11:40:59 1997  WATANABE Hirofumi  <watanabe@ase.ptg.sony.co.jp>
-
-	* eval.c (Init_Thread): allocate main_thread first to avoid crash.
-
-Thu Jan 23 02:09:26 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* gc.c (ObjectSpace): API modified. each_object method will do all
- 	  the iteration.
-
-	* eval.c (proc_call): wrong return from nested lambda.
-
-	* ext/GD/GD.c: debugged.
-
-Wed Jan 22 16:12:25 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* version 1.0-970122
-
-	* gc.c (gc_mark): forgot to mark match->str.
-
-	* ext/GD/GD.c: GD interface module.
-
-	* eval.c (PUSH_BLOCK): wrong value pushed as the block level.
-
-Mon Jan 20 14:01:31 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* eval.c (thread_run): no context switch in the critical section.
-
-Mon Jan 20 09:40:59 1997  WATANABE Hirofumi  <watanabe@ase.ptg.sony.co.jp>
-
-	* utils.c: supports 8+3 filenames
-
-Sat Jan 18 01:23:03 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* version 1.0-970118
-
-	* regex.c (PATFETCH): need cast to unsigned char.
-
-	* io.c (io_ctl): bug in case when arg is not a string.
-
-	* lib/tk.rb: forgot that Kernel#type returns the class name now.
-
-	* regex.c (re_search): "abc\n" =~ "^$" should not match.
-
-Fri Jan 17 12:31:37 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* version 1.0-970117
-
-	* ruby.c (ruby_options): constant PLATFORM, which is in the {cpu}-{os} 
-	  form, defined.
-
-	* configure.in: platform infomation embedded in the interpreter.
-
-	* regex.c (re_search): /^$/ did not match to "" by wrong exit condition.
-
-	* lib/thread.rb: re-write Mutex/Queue based on Thread.critical.
-
-	* eval.c (thread_set_critical): remove Thread.exclusive, add
-	  Thread.critical = TRUE/FALSE instead.
-
-	* re.c (reg_search): re-compile pattern if needed
-
-	* regex.c (PATFETCH): do translate at compile time
-
-Thu Jan 16 00:49:10 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* gc.c (gc_mark_frame): forgot to mark frame->cbase.
-
-	* regex.c (re_compile_pattern): /a$|b)/ causes error.
-
-	* regex.c (re_compile_pattern): /(^|b)/ causes error.
-
-	* version 1.0-970116
-
-	* re.c (Init_Regexp): set RE_CONTEXTUAL_INVALID_OPS flag.
-
-Tue Jan 14 02:09:06 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* eval.c (proc_call): Proc#call�򥤥ƥ졼���Ȥ��ƸƤ�������б�
-
-	* configure.in: nextstep���
-
-	* eval.c (rb_eval): a[b]=c��̵�̤�����������Ƥʤ�
-
-	* eval.c (f_send): ���ƥ졼���Ȥ��ƸƤФ줿�饤�ƥ졼���Ȥ��ƥ᥽��
-	  �ɤ�Ƥ֡�
-
-	* string.c (str_new4): match��ͭ�Ѥ������ؿ�
-
-	* re.c (reg_search): match�μ���(ʸ����)��ޥå���Ԥä�ʸ�����
-	  copy-on-write�Ƕ�ͭ
-
-	* string.c (str_hash): toupper�򤫤����郎��äƤ���
-
-	* array.c (sort_2): Fixnum��String�����̰������ƹ�®��
-
-Mon Jan 13 11:03:53 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* eval.c (thread_create): thread�����������ޤdz���ߤ����ꤷ�ʤ�
-
-	* eval.c (Init_Thread): ����ߥ����ߥ󥰤�100msec��
-
-Sat Jan 11 00:17:05 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* regex.c (re_search): �ޥå��˼��Ԥ����礬���ä�(������ľ�ä�����)
-
-	* io.c (io_ioctl,io_fcntl): ��2�������ά��ǽ��
-
-	* io.c (io_ioctl,io_fcntl): ����ͤ�IO���ä�������(�����ƥॳ����
-	  �������)���֤��褦�ˤ�����
-
-	* io.c (io_ctl): �����������λ����б�
-
-	* io.c (io_fcntl): file.c�����ư
-
-Fri Jan 10 17:01:47 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* version 1.0-970110
-
-	* ext/socket/socket.c (thread_connect): open(connect(2))��¾��
-	  thread��֥��å����ʤ��褦��
-
-	* eval.c (thread_create): exit�Ǥʤ��Ȥ���exit���Ȼפ�����
-
-Mon Jan  6 17:42:22 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* string.c (str_sub_s): ʸ����Ĺ���Ĺ��offset�θ���
-
-	* regex.c (re_search): ���˥ޥå�����ѥ�������$�Ǽ���
-
-Thu Jan  2 16:36:23 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* file.c (file_reopen): File��reopen(path�ޤ���IO�ǻ���)��
-
-	* io.c (io_reopen): IO��reopen(IO�ǻ���) -- change class�Ĥ�
-
-Wed Jan  1 11:09:01 1997  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* io.c (f_select): timeout��nil���֤�
-
-Fri Dec 27 13:06:44 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* file.c (file_s_open): ���֥��饹�ǤϤ��Υ��饹�Υ��󥹥��󥹤���
-	  ���褦�ˡ�
-
-Fri Dec 27 08:58:27 1996  ono@isl.nara.sharp.co.jp
-
-	* numeric.c (flo_to_s): index()��Ȥ�ʤ���strstr()�ˡ�
-
-Thu Dec 26 01:34:17 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* lib/tk.rb: place���Ȥ���褦��
-
-	* pack.c (endian): �ޥ���DYNAMIC_ENDIAN����ꤹ��ȼ¹Ի���endian
-	  ��Ƚ�ꤹ��褦�ˡ�
-
-	* eval.c (thread_alloc): �����˺��Υ��Ф����ä���
-
-Wed Dec 25 00:33:19 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* version 1.0-961225
-
-	* io.c (Init_IO): new��̵����
-
-	* lib/tkthcore.rb: tk_call "global $foo; set foo 5"�ʤɤ�Ǥ���褦��
-
-	* eval.c (thread_restore_context): $~, $_�ǥ����å�������Ƥ���
-
-	* process.c (rb_waitpid): thread�˰���б�
-
-Tue Dec 24 15:20:58 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* version 0.99.4-961224
-
-	* configure.in: char��unsigned���ɤ���������å�
-
-	* regex.c (SIGN_EXTEND_CHAR): __CHAR_UNSIGNED__�ˤ��б�
-
-	* pack.c (pack_unpack): ����Ū��signed char����ꡥ
-
-Mon Dec 23 14:41:23 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* ruby.c (load_file): ɸ�����Ϥ���Υ�����ץȤǰ���ե������Ȥ�
-	  �ʤ��褦��
-
-	* object.c (f_integer): `0x', `0'�ʤɤ�base���᤹��褦�ˡ�
-
-Fri Dec 20 01:44:39 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* Makefile.in (flock.o): flock���б�
-
-Thu Dec 19 20:13:32 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* version 0.99.4-961219
-
-Wed Dec 18 00:06:48 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* glob.c (glob_filename): strrchr���ޥ����ξ����б�
-
-	* configure.in: <sys/select.h>������å�
-
-	* ext/kconv/kconv.c: 1.62�١�����
-
-	* ext/kconv/kconv.c: Kconv�⥸�塼��
-
-	* string.c (str_substr): len������ʸ������Ĺ�������б�
-
-	* parse.y (iterator): ��$bar do .. end�פʤɤϵ����ʤ��褦��
-
-	* parse.y (iterator): FID(foo!,foo?)��do�����Υ��ƥ졼���ˤǤ��롥
-
-	* missing/flock.c (flock): lockf()��Ȥä�����
-
-	* file.c (file_flock): flock�����
-
-Tue Dec 17 12:13:38 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* version 0.99.4-961217
-
-Fri Dec 13 02:05:03 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* configure.in: RUBYLIB�Υ����Ȥ���(@mix/awk offline)
-
-	* dln.c: AIX���������(@mix/awk offline)
-
-	* eval.c (thread_schedule): critical section�Ǥ�����Ū�ʥ���ƥ���
-	  �ȥ����å��ϵ����ʤ��Ȥޤ���
-
-	* re.c (reg_search): match�˼��Ԥ�������$~��nil�ˡ�
-
-	* re.c (reg_search): ���match����������褦��
-
-Thu Dec 12 17:03:30 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* numeric.c (flo_to_s): 2.0.to_s -> 2.0��
-
-	* eval.c (thread_save_context): $_, $~��thread�����¸
-
-	* eval.c (thread_kill): main thread�Ǥ�exit(0)
-
-	* string.c (str_split_method): �ְ�ä���̤��֤��Ƥ���
-
-Thu Dec 12 15:32:48 1996  WATANABE Hirofumi  <watanabe@ase.ptg.sony.co.jp>
-
-	* dir.c: CYGWIN32�б�
-
-	* ext/socket/socket.c: CYGWIN32�б�
-
-	* io.c: CYGWIN32�б�
-
-Thu Dec 12 14:43:51 1996  Jun Kuroda  <j_kuro@pluto.ai.kutech.ac.jp>
-
-	* lib/tk.rb: wish4.2��õ������˴ޤ��
-
-	* config.guess: JCC�б�
-
-Thu Dec 12 00:41:17 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* version 0.99.4-961212
-
-	* parse.y (parse_string): """..."""�Ϥ�Ϥ�̵�������Ȥˤ���
-
-	* parse.y (parse_regx): %r|...|��terminator�� \ �ǥ��������פǤ���
-	  �褦��
-
-	* signal.c (posix_signal): sigaction��Ȥ�signal
-
-	* configure.in: posix signal/bsd signal���
-
-Wed Dec 11 17:47:35 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* eval.c (thread_schedule): critical section�Ǥϥ���ƥ����ȥ�����
-	  ���������ʤ��褦��
-
-	* lib/thread.rb: SharedMutex���饹
-
-	* lib/jcode.rb: String#scan��Ȥ��褦��
-
-Tue Dec 10 12:21:28 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* version 0.99.3-961210
-
-	* string.c (str_split_method): ����ɽ����()��ޤ���˥Х�
-
-	* lib/jcode.rb: ����äȤޤ��ˤʤä�
-
-	* string.c (tr_setup_table): �ִ�ʸ����û������(2ʸ��)�ΤȤ��ΥХ�
-
-Mon Dec  9 11:38:04 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* string.c (str_scan): ʸ����Υޥå���Ԥ������ƥ졼���Ȥ��Ƥ�ư
-	  ���
-
-	* regex.c (re_copy_registers): allocated�����������Ƥ��ʤ��ä�
-
-	* re.c (match_to_s): $~��ʸ����
-
-	* re.c (match_to_a): $~�����󲽤Ǥ���褦��
-
-	* re.c (match_getter): �쥸���������������Ƥ��ʤ��ä�
-
-Thu Dec  5 11:06:10 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* string.c (str_split_method): �ޥå����ʤ��ä���̤϶�ʸ�����
-	  push����٤��ǤϤʤ�
-
-	* string.c (str_succ): ����ե��٥åȤ�ޤޤʤ�ʸ�����б�
-
-Wed Dec  4 10:48:09 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* version 0.99.3-961204
-
-	* io.c (io_binmode): DJGPP�Ǥ�binmode�б�
-
-	* sprintf.c (f_sprintf): int���ϰϤο��ͤ�ľ��sprintf���Ѵ�����
-
-	* sprintf.c (f_sprintf): "%02s"�����ʤ�
-
-	* re.c (reg_search): index��SEGV
-
-Tue Dec  3 10:09:36 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* version 0.99.3-961203
-
-	* ext/extmk.rb.in (install): INSTALL_DATA����INSTALL���ѹ�
-
-	* dln.c: hpux�б�
-
-	* string.c (str_aset_method): ����ͤ�ޤ��ϰϤǤ��㳰�򵯤����ʤ�
-
-	* array.c (ary_replace): ����ͤ�ޤ��ϰϤǤ��㳰�򵯤����ʤ�
-
-	* array.c (beg_len): beg==end�λ���Ĺ��0��
-
-Mon Dec  2 14:07:12 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* configure.in: HP shl�б�
-
-	* string.c (str_upto): beg > end�λ�̵�¥롼�פ������Τ�ߤ᤿
-
-	* range.c (range_each): String#upto����������줿�����б�
-
-	* string.c (str_split_method): "ABC".split(/(B)/)����ư��
-
-Sat Nov 30 01:43:52 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* eval.c (rb_eval): undef��SEGV
-
-Fri Nov 29 12:17:59 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* sample/ruby-mode.el (ruby-parse-region): %Q#..#�ʤɤ��б�������
-	  �������ڤ�ʸ�����黻�Ҥǹ����ˤ�����ˤ��б��Ǥ��ʤ��ä���
-
-	* re.c (reg_raise): �㳰�Ǥ⥹��å���򥨥�������
-
-	* re.c (reg_inspect): ����å���򥨥�������
-
-	* parse.y (parse_string): `%[QqXxRr](.)..\1'�ʤ�ʸ�������(�ƥ���
-	  ����)
-
-	* parse.y (parse_qstring): '''...'''���
-
-	* ext/dbm/dbm.c (Init_dbm): �Ҹ�key?,value?���ɲ�
-
-	* ext/dbm/dbm.c (Init_dbm): includes->include?
-
-	* hash.c (Init_Hash): �Ҹ�key?,value?,include?���ɲ�
-
-	* eval.c (rb_eval): unless��else�᤬�¹Ԥ���ʤ�(������)
-
-	* string.c (str_sub_iter_s): ���ƥ졼���֥��å���ǥޥå����Ԥ��
-	  ��Ȱ��֤������(����̵�¥롼�פ������)
-
-	* string.c (str_resize): len��0�λ�size��Ĵ�����Ԥ��ʤ��ä�
-
-Thu Nov 28 00:59:54 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* version 0.99.3-961128
-
-	* parse.y (parse_string): 3-quote style��ʸ����(��:"""abc"d"e""")
-
-	* configure.in (EXTSTATIC): ext����Ū�˥�󥯤�����ˤ�ruby��dll��
-	  �Ȥ��褦��
-
-	* io.c (Init_IO): gets�ΰ������ְ�äƤ���
-
-	* string.c (str_each_line): RS������Ū�˻���Ǥ���褦��
-
-Wed Nov 27 12:37:46 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* version 0.99.3-961127
-
-	* eval.c (rb_eval): iver defined? ��self����ꤹ��Τ�˺�줿
-
-	* io.c: gets����RS������Ū�˻���Ǥ���褦��
-
-	* ext/extmk.rb.in (install): static link�˼���
-
-Tue Nov 26 10:33:04 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* version 0.99.3-961126
-
-	* string.c (str_sub_s): �ִ����ʸ����Ĺ�����ְ�äƤ���
-
-Mon Nov 25 09:11:22 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* numeric.c (fix_rshift): 32�ʾ�α����եȤ�0���֤��褦��(C��
-	  rshift��(x>>(y%32))���֤��Ƥ���)��
-
-	* string.c (str_gsub): �ִ����Ԥ��ʤ���礬���ä�
-
-	* string.c (str_resize): ������ɬ�פʻ�����realloc
-
-Thu Nov 21 04:13:21 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* configure.in (EXTSTATIC): --with-static-linked-ext�����ƤΥ⥸�塼
-	  �����Ū��󥯤���褦��
-
-	* pack.c (pack_unpack): �����β��Ԥ��ʤ����ˤ�����å�����򥹥���
-	  �פ���褦�� 
-
-Wed Nov 20 96 21:42:51 1996  Yasuo OHBA  <jammy@shljapan.co.jp>xc
-
-	* configure.in: freebsd�б�
-
-Wed Nov 20 10:24:24 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* ext/extmk.rb.in (install): �̾����Ѥ�LDFLAGS�ȥ����ʥߥå���
-	  ���Ѥ�DLDFALGS��ʬΥ
-
-	* ext/extmk.rb.in (install): ����ѥ��������������Τ���Ū���
-	  �Υꥹ�Ȥ��ɲä���
-
-	* eval.c (f_missing): ���֥������Ȥ�ʸ����ɽ����Ĺ��������Хåե�
-	  ����٤��Ƥ���
-
-	* process.c (proc_exec_v): fork�������㳰��ȯ�������ƤϤ����ʤ�
-
-Tue Nov 19 13:28:15 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* version 0.99.3-961119
-
-	* eval.c (mod_method_defined): Module#method_defined? ���ɲ�
-
-	* parse.y (call_args): ������ͣ��Υ��ޥ�ɥ�����Ǥ�����ΥХ�(��
-	  ���ͤ�Ÿ������Ƥ��ޤ�)
-
-Mon Nov 18 13:28:18 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* string.c (str_sub): ���Ԥ�������nil���֤��Ƥ���
-
-	* string.c (str_split_method): �������ϰ��֤���ư���Ƥʤ��ä�
-
-	* ext/socket/socket.c (sock_s_getservbyaname): �ޤ��ְ�äƤ���
-
-	* version 0.99.3-961118
-
-	* string.c (str_sub_s): ����ʸ������ִ�����Τ�ߤ᤿
-
-	* pack.c (encodes): �ΰ賰�򥢥��������Ƥ���
-
-Fri Nov 15 17:10:35 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* bignum.c (big_divmod): Bignum�������ξ����б�˺��
-
-	* sample/ruby-mode.el (ruby-expr-beg): word?�����ؤ��б����Դ���
-
-Wed Nov 13 15:42:40 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* string.c (str_tr_s_bang): tr_s��tr���Ԥ��Ƥ��ʤ��ä�
-
-	* eval.c (rb_eval): autoload���饹�Υ����å�
-
-	* string.c (f_sub): sub��sub!��Ʊ��ư��ˤʤäƤ���
-
-	* eval.c (thread_sleep): stop��sleep��ʬΥ
-
-Mon Nov 11 13:53:19 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* version 0.99.3-961111
-
-	* numeric.c (fix_step): to, step�������ʳ��ξ����б�
-
-	* eval.c (rb_call): dynamic var��dynamic scoping�ˤʤäƤ���(����
-	  �Ϥޤ���)
-
-	* string.c (str_chop_bang): Ĺ��0��ʸ�����chop�ǡ��ΰ賰�Υ�����
-	  ����ȯ�����Ƥ�����
-
-	* parse.y (yyerror): ������Ƥ��ΰ賰�򥢥��������Ƥ���
-
-Fri Nov  8 11:54:46 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* eval.c (thread_yield): scope��heap�˥��ԡ�
-
-Thu Nov  7 09:56:53 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* numeric.c (num_coerce): �Ȥꤢ����ξ�դ�Float���Ѵ����뤳�Ȥ�
-
-Wed Nov  6 10:45:13 1996  Yasuo OHBA  <jammy@shljapan.co.jp>
-
-	* lib/parsearg.rb: ��2�������ѹ���
-
-Tue Nov  5 14:21:09 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* version 0.99.3-961105
-
-Sat Nov  2 01:11:40 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* bignum.c (big_pow): typo (dy -> dx)
-
-	* bignum.c (big_divmod): �Τ�ʤ�����float���Ѵ����Ƥߤ�
-
-	* numeric.c (fix_lshift): �������ΥХ�(��ˤʤäƤ���)
-
-	* bignum.c (big_pow): ̵�̤�float�ؤ��Ѵ���ʤ�����
-
-	* math.c (math_atan2): typo(x -> y)
-
-Fri Nov  1 15:30:59 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* ext/socket/socket.c (sock_gethostname): gethostname���ʤ����ˤ�
-	  uname��Ȥäƥۥ���̾������
-
-	* ext/etc/etc.c (etc_getlogin): getlogin��NULL���֤��Ƥ�Ķ��ѿ���
-	  Ĵ�٤�褦��
-
-	* object.c (krn_clone): ���֥������ȤΥե饰�⥳�ԡ�
-
-	* hash.c (rb_cmp): �ϥå������Ӥ�`=='�Ǥʤ�`eql?'���ѹ�
-
-	* math.c (Need_Float): Float()��Ȥä��Ѵ�����
-
-	* compar.c (cmp_gt): �����α��դ��֤����ͤ�̾�Ĥ��ĤäƤ���
-
-Thu Oct 31 12:55:51 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* version 0.99.3-961031
-
-	* numeric.c (Init_Numeric): typo
-
-	* eval.c (error_print): Ĺ������trace back�������ά����
-
-	* regex.c (re_compile_pattern): ���Ѥ�range���б�
-
-Wed Oct 30 03:03:18 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* version 0.99.3-961030
-
-	* io.c (f_ungetc): �ؿ����ɲ�
-
-	* eval.c (dyna_var_asgn): return��˺��
-
-Tue Oct 29 10:05:28 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* string.c (f_split): �ؿ�split���ɲ�
-
-	* eval.c (rb_call): �ͥ��Ȥ�����¦�Υ��饹/�⥸�塼�������򻲾�
-	  �Ǥ���褦��
-
-Mon Oct 28 09:51:03 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* string.c (str_sub): offset��ʸ���������ˤ�����Υ����å�
-
-	* regex.c (re_match): ������Ƥ�쥸�����ο���1¿���ä�
-
-	* io.c (io_gets): $/ = ""��ư���perl�˹�碌��(awk�ȤϤ���äȰ�
-	  ���餷��)
-
-	* io.c (io_gets): $/ = nil�λ�������®��
-
-	* string.c (str_split_method): ��̤�null�˥ޥå��������ˤ�̵�뤷
-	  �ʤ��褦��
-
-	* string.c (str_split_method): ��̤˥ޥå�����ʬ��limit�ο��˴ޤ�
-	  �ʤ��褦�ˡ�
-
-	* numeric.c (num_coerce_bin): coerce��������ѹ���2���Ǥ�����
-	  [x,y]���֤��褦��
-
-	* sample/ruby-mode.el (ruby-calculate-indent): "do |aa|"������
-	  ��������
-
-Sat Oct 26 01:43:51 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* ext/marshal/marshal.c (w_object): �ӥ�ȥ��󥯥饹�Υ��֥��饹��
-	  ����������Ǥ���褦��
-
-	* ext/marshal/marshal.c (w_object): �桼�����dump��ͥ��
-
-	* numeric.c (flo_coerce): Float()��Ȥä����
-
-	* numeric.c (Init_Numeric): Numeric��new��undef�Ϥޤ���
-
-	* ext/marshal/marshal.c (w_symbol): ����ܥ������(ʸ����)�ϰ��٤�
-	  ���ե�����˽񤭽Ф��ʤ���
-
-	* sample/ruby-mode.el (ruby-parse-region): if/while�����Ҥ��б���
-	  �ʤ��ʤäƤ���
-
-	* bignum.c (Init_Bignum): Bignum.new�����
-
-	* eval.c (rb_eval): ����ɾ����˥ե�����̾�ȹ��ֹ�������
-
-	* numeric.c (flo_div): typo
-
-	* sample/ruby-mode.el (ruby-parse-region): def /, def `���б�
-
-Fri Oct 25 09:26:29 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* sample/ruby-mode.el (ruby-calculate-indent): "do |aa|"���б�
-
-	* array.c (ary_aset): index��fixnum�ξ�����äȹ�®��
-
-	* eval.c (thread_fd_writable): �񤭹�������select�����å�
-
-	* array.c (ary_assoc): ̵�¥롼�פ������
-
-	* eval.c (thread_wait_for): select�����顼��λ��������linux�ʳ���
-	  ��ư��������ʤ��ä���
-
-Thu Oct 24 08:26:48 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* eval.c (backtrace): `$@'��ʸ���󤫤�������ѹ�������
-
-	* eval.c (eval): eval����㳰ȯ�����֤���¸����
-
-	* bignum.c (bigsub): ���ڥ��ɤ��羮��Ӥμ���
-
-	* re.c (reg_search): ľ�ܻ��Ȥ��ʤ����ˤ�`$~'�����åȤ����褦��
-
-Wed Oct 23 10:40:10 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* version 0.99.2-961023
-
-	* ext/marshal/marshal.c (r_bytes): malloc���ᡤalloca��Ȥ�
-
-	* sample/ruby-mode.el (ruby-calculate-indent): ��̤��б����ѹ���
-	  ()��Ǥϥ���ǥ�Ȥ��٥���碌��褦��
-
-Tue Oct 22 12:59:11 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* hash.c (hash_s_new): size�����Ǥ���褦��
-
-	* ext/marshal/marshal.c (w_object): dump���뿼�����¤����Ǥ����
-	  ����
-
-	* array.c (ary_s_new): size����ꤷ�����ν����˺��
-
-	* object.c (f_float): big2dbl�����˺�졥
-
-	* bignum.c (bigsub): �礭���ζᤤBignumƱ�Τα黻�Ƿ�̤���ˤʤ�
-	  ���˴ְ㤤�����ä���
-
-	* array.c (ary_aset): �ִ�����ִ�����Ʊ��Ĺ���λ����Ƥ�
-	  shift(memmove)���ʤ��褦�ˡ�
-
-	* ext/marshal/marshal.c (marshal_dump): �ե�����ե����ޥåȤ˥С�
-	  ������������褦��
-
-	* ext/marshal/marshal.c (tmpnam): linux-aout-dln�Ѥ����
-
-Mon Oct 21 08:40:20 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* ext/socket/socket.c (sock_s_gethostbyname): hostent��¤�Τξ���
-	  ���֤�
-	  (sock_s_gethostbyaddr): IP���ɥ쥹����hostent��¤�Τ�����
-	  (sock_s_getservbyaname): getservbyname(3)
-
-Fri Oct 18 10:37:36 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* sample/ruby-mode.el (ruby-indent-to): ��ư�襫��ब��ˤʤ�Х�
-
-	* eval.c (compile): eval�Ǹ��������ι��ֹ�ǥ��顼��ɽ������
-
-Thu Oct 17 09:52:28 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* eval.c (eval): eval��ʸˡ���顼�����ä�����SEGV
-
-	* lib/safe.rb: Restricted.eval����������¤�ä��롥
-
-	* eval.c (error_print): �Хå��ȥ졼���ν��ϡ�caller���㳰ȯ������
-	  ��Ĵ�������������꤬�Ф�(����ʤ��Ȥ򤷤ʤ�����ɤ��Τ�����)
-
-	* eval.c (make_backtrace): �Хå��ȥ졼��������
-
-Wed Oct 16 12:56:22 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* ruby-man-0.99.2-jp/index.html: ���ܸ��ǥɥ�����Ȥδ���(Ĺ���ä���)
-
-	* re.c (reg_regcomp): $=��nil����
-
-	* string.c (f_chop): $_������chop
-
-Tue Oct 15 11:04:23 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* version 0.99.2-961015
-
-Mon Oct 14 18:22:38 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* eval.c (thread_schedule): BOW�б���select��-1���֤������˥Х�(��
-	  ��do .. while��continue����Ƭ�˥����פ���Ȼפ�����Ǥ�������
-	  ���ľ�����ä��Τ� ^^);;;;;
-
-	* sample/ruby-mode.el (ruby-mode-syntax-table): ?��syntax��"/"�Ǥ�
-	  �ޤ����餷��
-
-	* hash.c (rb_hash): name conflict
-
-Fri Oct 11 00:23:05 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* version 0.99.2-961011
-
-	* ext/marshal/marshal.c (w_object): ���ư���Ƥ��ʤ��ä��۴ĥ��֥���
-	  �����б��򳰤�����
-
-	* hash.c (rb_hash): Fixnum��ʸ����ι�®��
-
-	* ext/marshal/marshal.c (w_object): ̵�̤ʥǡ����κ��(�ե����ޥ�
-	  �Ȥ���ߴ���)
-
-	* io.c (io_readline): ����ͤ�����
-
-	* ext/marshal/marshal.c (marshal_dumps): MSDOS�б�
-
-	* ruby.c (load_file): MSDOS�б�
-
-Wed Oct  9 17:46:27 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* ext/extmk.rb.in (install): ̵�̤ʥ��ԡ����򤱤�
-
-	* string.c (str_sub_method): �ޥå����ʤ��ä�����String#sub���ͤ�
-	  ��äƤ�����
-
-	* eval.c (obj_extend): extend��������object_extended��Ƥ֤褦��
-
-Tue Oct  8 00:55:38 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* eval.c (thread_alloc): ������ʿ�Ѳ�
-
-	* eval.c (thread_schedule): join�ΥХ�����
-
-	* eval.c (thread_wait_for): select�ؤγ���ߤʤɤ��б�
-
-	* eval.c (thread_select): linux��select�ε�ư���б�(timeout���Ѳ�
-	  ����)
-
-Mon Oct  7 09:47:19 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* version 0.99.2-961007
-
-	* eval.c (PUSH_BLOCK): the_class����¸��˺��Ƥ�����
-
-	* ext/dbm/dbm.c (fdbm_store): size����¸�����꤬�ְ�äƤ���
-
-	* ext/socket/socket.c (s_accept): thread�б����Ƥ��ʤ��ä�
-
-Sat Oct  5 01:32:27 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* io.c (io_readchar): EOF���㳰��ȯ��������
-
-Fri Oct  4 11:59:54 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* ext/marshal/marshal.c (w_object): Hash��Object�������ɬ�פʥϥ�
-	  ����ơ��֥뤬�Ϥ���Ƥ��ʤ��ä���
-
-	* variable.c (rb_path2class): �桼��������饹������˼��Ԥ��Ƥ���
-
-	* variable.c (rb_path2class): ���饹��¸�ߤ��ʤ����Υ��顼��Fatal
-	  ����NameError�ء�
-
-	* range.c (range_s_new): first,last��ξ��Numeric�λ����顼�ˤʤä�
-	  ������
-
-	* range.c: start->first, end->last
-
-Wed Oct  2 02:02:46 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* file.c: DJGPP��chmod,chown��Ȥ���褦��(�ä�DOS��chown������Τ�?)
-
-	* class.c (rb_singleton_class): �ӥ�ȥ��󥯥饹��extend�������ð�
-	  �᥽�åɤ��ɲä�����Ǥ���褦��
-
-	* variable.c (rb_set_class_path): �桼������Υȥåץ�٥륯�饹��
-	  path�����ꤷ�ʤ�
-
-	* eval.c (eval): �㳰��RuntimeError�˲����Ƥ���
-
-	* eval.c (eval): eval����㳰��ɽ���β���
-
-	* eval.c (eval): eval_with_binding�Ȥΰ��ܲ�
-
-	* eval.c (rb_eval): ���饹/�⥸�塼��������椫�������Υ��饹/��
-	  ���塼�뤬���ȤǤ���褦��
-
-Tue Oct  1 01:40:09 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* version 0.99.2-961001
-
-	* parse.y: cur_cref��2���������Ƥ���
-
-	* signal.c (trap): SIGSEGV��SIGBUS�Τʤ�������б�
-
-	* io.c (Init_IO): ���������פλ���ְ㤤
-
-Mon Sep 30 15:28:00 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* version 0.99.2-960930
-
-	* config.guess,config.sub: $host_os�����������ꤵ��ʤ�
-
-	* eval.c (rb_eval): yield���������ʤ�self�����ꤵ��Ƥ���
-
-	* eval.c (ruby_run): toplevel���㳰�����ΥХ�
-	
-Mon Sep 30 09:13:26 1996  WATANABE Hirofumi  <watanabe@ase.ptg.sony.co.jp>
-
-	* djgpp�б�
-
-Sat Sep 28 02:45:10 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* version 0.99.2-960928
-
-	* sample/ruby-mode.el (ruby-beginning-of-block): �֥��å�����Ƭ��
-	  ��ư(����������ǥ�Ȥ��Ƥ��ʤ���ư��ʤ�)
-	  (ruby-end-of-block): Ʊ��
-
-	* eval.c (class_s_new): Class#new�����ƥ졼���Ȥ��ƸƤФ줿����
-	  initialize�⥤�ƥ졼���Ȥ��ƸƤФ��褦��
-
-	* signal.c (sigsegv): SEGV��backtrace��ɽ������褦��
-
-Fri Sep 27 09:51:07 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* version 0.99.2-960927
-
-	* eval.c (error_print): �����Τʤ�raise�ǥ�å�������������ɽ����
-	  ���褦�ˡ�
-
-	* eval.c (rb_longjmp): mesg��nil�λ�RuntimeError���������롥
-
-	* eval.c (f_raise): �������ʤ������б�
-
-	* eval.c (thread_mark): stack��ˤʤ��ǡ����Υ��ɥ쥹�Ѵ���Ԥä�
-	  ������
-
-	* eval.c (Init_Thread): ����ߤδֳ֤�1�ä�Ĺ��������
-
-Thu Sep 26 16:02:45 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* eval.c (thread_schedule): ���٥ڥ�ǥ��󥰤ˤʤ�ȥե饰�����ꥢ
-	  ����Ƥ��ʤ��ä���
-
-	* process.c (rb_proc_exec): system/exec�ΰ�������ʸ����Ǥ��ä���
-	  �硤�㳰��ȯ�����٤����ä���
-
-	* config.sub/config.guess: ��������Τ��֤�����
-
-Thu Sep 26 15:41:35 1996  WATANABE Hirofumi  <watanabe@ase.ptg.sony.co.jp>
-
-	* io.c (next_argv): -i.bak��BOW��DOS�����
-
-Thu Sep 26 01:31:43 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* io.c (io_sysread): EOF���㳰
-
-	* io.c (f_readline): EOF���㳰��ȯ������褦�ˡ�gets�ϸߴ����Τ���
-	  nil���֤��ޤޤˤ���
-
-	* eval.c (proc_call): lambda�����return��IN_BLOCK�ե饰��Ω�ä���
-	  �ޤ��ä�
-
-	* eval.c (PUSH_BLOCK2): thread���б����뤿��Block�����stack�˥��ԡ�
-
-Wed Sep 25 11:54:11 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* parse.y (method_call): Const::method()������Ȥ���褦�ˤ��Ƥߤ���
-	  ������̤Ͼ�ά�Ǥ��ʤ���
-
-	* sample/test.rb: Process.kill��¸�ߤ�Τ���Ƥ���ƥ��Ȥ�Ԥ�
-
-	* eval.c (eval_with_binding): ��2�����Ȥ���binding(�ޤ���lambda)��
-	  Ϳ����Ȥ��δĶ���eval��¹Ԥ���褦�ˤ���
-
-	* eval.c (f_binding): ���ߤ�binding���֤��ؿ�
-
-	* eval.c: block��¤�Τ�the_class����¸������Ф��ɲ�
-
-	* process.c (Init_process): kill,wait,waitpid��Process�˰�ư
-
-Tue Sep 24 02:44:43 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* sample/ruby-mode.el: �����������꤬¿���Τǰ����ι�®�����˴���
-	  �̤Υ��ץ�������Ȥä���
-
-	* lib/tk.rb (Tk.pack): ʣ���Υ�����ɥ�������դ���pack
-
-Sat Sep 21 11:08:09 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* parse.y (exprs): ��ʸ������դ���褦��ʸˡ���ѹ������ޤǤϲ���
-	  ��Ϣ³������������Ƥ�����
-
-Fri Sep 20 11:39:18 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* Fail����Ⱦ��̾���Ĥ��㳰���ѹ���
-
-	* re.c (Init_Regexp): ̾���Ĥ��㳰��Ƴ����
-
-	* eval.c (f_missing): Object��inspect���ʤ���
-
-	* object.c (inspect_i): Object#inspect��loop�����
-
-	* regex.c (re_search): /^$/��""�˥ޥå����ʤ��ä���
-
-Thu Sep 19 19:25:12 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* regex.c (re_search): /^$/������Ԥ˥ޥå����Ƥ�����
-
-Tue Sep 17 10:28:11 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* version 0.99.2-960917
-
-Mon Sep 16 10:47:56 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* sample/ruby-mode.el (ruby-calculate-indent): �黻�ҷ�³�ξ���
-	  ʸ�����Ƚ��ΥХ�
-
-	* sample/ruby-mode.el (ruby-calculate-indent): else�ʤɤμ��ιԤ�
-	  ����ǥ�ȷ׻�����������
-
-Sat Sep 14 08:37:19 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* version 0.99.2-960914
-
-Fri Sep 13 08:06:03 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* ext/socket/socket.c (tcpaddr): port�ֹ��ntohs��Ĥ�˺��
-
-	* dln.c (link_undef): �ơ��֥�μ��ब�ְ�äƤ�����
-
-	* bignum.c (bigadd): ��������ȯ��������˷׻��㤤�������Ƥ�����
-
-	* parse.y (iter_do_block): do..end�Ǥ�dynamic variable��
-
-	* bignum.c (big_pow): ������Τʷ׻���(����Ʊ�ΤǤ�float���Ѵ�����
-	  ��)��
-
-Thu Sep 12 13:11:55 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* variable.c (rb_set_class_path): String���饹����������������
-	  String���äƤ������ȹ��ߥ��饹�ˤ�path�Ϥ���ʤ�
-
-	* parse.y (yylex): 0.1��0�ˤʤäƤ���
-
-	* parse.y (yylex): ���ֹ��������
-
-	* gc.c (oblist_live_obj): ���������Ƥ���������Υ��֥������Ȥ��֤�
-	  ���ƥ졼�������Υ��饹(�ޤ��ϥ��֥��饹)�������Υ��󥹥��󥹤���
-	  ��each_object_of�����������
-
-	* class.c (rb_define_class_id): ̵�̤ʥ��饹�������ƤƤ��������
-	  �Ȥ���̤������Υ��饹���֥������Ȥ�¸�ߤ��Ƥ�����
-
-Wed Sep 11 00:56:23 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* parse.y (yylex): octal������θ��Ф������Τ�(090�ϥ��顼�Ȥ�)��
-
-	* bignum.c (big_minus): y��x����礭�����˥��顼��
-
-	* parse.y (yylex): ���顼���ֹ��ɽ���������Τ�
-
-	* sample/ruby-mode.el (ruby-expr-beg): �ѿ�̾��1ʸ���λ���ư���
-	  ������
-
-	* sample/ruby-mode.el (ruby-calculate-indent): ?/�ǥ롼�פ������
-	  ����������
-
-	* enum.c (enum_min,enum_max): sort�Τ褦�˥��ƥ졼���Ȥ��Ƥ�ư�
-	  ��褦�ˡ�
-
-	* enum.c (enum_find_all): typo
-
-Tue Sep 10 12:07:12 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* node.h (nd_line): NODE��line��flags�˲�������ƥ��֥������ȥ���
-	  ���򾮤�������������:32bit int�Υޥ���ξ�硤�ե�����ιԿ���
-	  32767��ۤ���������ɽ������ʤ���
-
-	* st.c: hash��compare�δؿ����Ф�¤�Τ˥ѥå������饹Ū�ʻȤ�
-	  ����Ԥ���1 table������4 byte������
-
-Mon Sep  9 16:35:54 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* file.c (file_truncate): �󶡤���ʤ����ˤ����̤��㳰��ȯ�������
-	  ���ˡ�
-
-	* eval.c (Init_Proc): ��Ŭ�ڤʰ��֤�local-jump���㳰�ˡ�
-
-Sat Sep  7 17:06:15 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* eval.c (proc_call): �ޤ��������פ������å���ˤ�����ˤ϶ɽ�æ��
-	  ��ͭ���ˤ��롥����ǡ�proc����������call���뤳�Ȥϡ��������פ�æ
-	  �Ф��ʤ��¤ꡤyield��Ʊ����̣����Ĥ��Ȥˤʤ롥
-
-Fri Sep  6 13:30:59 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* sample/ruby-mode.el (ruby-indent-to): ����ǥ�Ȥ��Ѥ��ʤ�����
-	  �ϥХåե����ѹ����ʤ���
-	  (ruby-calculate-indent): �ޤ�ʸ�����������Ƚ�Ǥ��Ƥ��顤���ι�
-	  ����ѡ�����Ԥ���defun���礭���ʤä����ι�®����
-	  (ruby-in-string-p): ʸ������������ɤ�����Ƚ�Ǥ���ؿ�(������
-	  parse����ʬΥ)
-	  (ruby-parse-region): ʸ������Ф��������Ϥ�����
-	  (ruby-beginning-of-block): �֥��å�����Ƭ��
-	  (ruby-end-of-block): �֥��å���������(�٤���)
-
-Thu Sep  5 14:23:07 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* file.c (file_s_split): [dirname,basename]��split���롥
-
-	* eval.c (rb_eval): eval����Ǥ�������ͤ��������ʤ�褦�ˡ������
-	  ����˴ؤ��Ƥ���Ū�ʥ������פ��ݾڤ����褦�ˤʤä���
-
-	* st.c (rehash): �ϥå������ηϿ���2����1.79�ˡ��任������ɤ���
-	  ���֤��褦�ˡ�
-
-Thu Sep  5 00:32:07 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* eval.c (class_superclass) ���饹�Υ����ѡ����饹���֤��᥽�åɡ� 
-
-Wed Sep  4 16:54:56 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* random.c (f_rand): Bignum��long���ϰϤ�ۤ���Float���Ф��������
-	  ȯ���Ǥ���褦�ˡ�
-
-	* struct.c (struct_alloc): Fatal�ǤϤʤ��㳰��ȯ��������褦��(��
-	  ��λ��Ѥ�ȯ��������)��
-
-	* struct.c (struct_s_members): Struct���ðۥ᥽�åɤǤϤʤ�������
-	  ���줿Struct���饹���ðۥ᥽�åɤˤ�����
-
-	* st.c (st_init_table): ruby���Ѥ˥ѥ�᥿�����ˤ���(����
-	  �������ä�)
-
-Mon Sep  2 11:37:59 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* array.c (ary_shift): capa�����ޤ�ˤ��礭�����ˤ��ΰ��REALLOC
-	(ary_pop): Ʊ��
-
-	* string.c (str_inspect): multibyte character �б��˥ߥ���
-	(str_inspect): unsigned char�ˤ��ʤ������Ÿ������Ƥ��ޤ�
-
-	* parse.y (primary): `::'��primary�˰�ư Foo::Bar.Baz�����顼�ˤ�
-	  ��ʤ��褦�ˡ�
-	
-	* parse.y (primary): ���ڥ졼���������ðۥ᥽�åɤ�����Ǥ��ʤ�
-
-	* random.c (f_rand): max��0�λ����б�
-
-	* io.c (io_printf): �ؿ���������Ƥ��������󥿥ץ꥿����Ͽ���Ƥ���
-	  �����
-
-	* file.c (file_s_basename): ��2������̵�����˥��顼��
-
-Thu Aug 29 10:49:40 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* parse.y (expr): ���ƥ졼���ο������ˡ�method do .. end�׷������
-	  �Ѥ�������������Τη�����ͭ����
-
-	* sample/ruby-mode.el (ruby-calculate-indent): end�ο�������¿����
-	  ��ˤ⥨�顼�򵯤����ʤ��褦�ˡ�
-
-Wed Aug 28 09:41:36 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* numeric.c (upto,downto,step,times): �оݤ�fixnum���ϰϤ�ۤ��Ƥ�
-	  ư���褦�ˡ�
-
-Mon Aug 26 10:04:37 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* missing/setenv.c (envix): typo(missing `== 0' for memcmp)
-
-	* dir.c (dir_foreach): foreach(dir open -> read loop -> close�ޤ�)
-
-	* io.c (io_foreach): foreach(file open -> read loop -> close�ޤ�)
-
-	* Fatal�Τ�����ª��ǽ�ʤ����Ĥ����㳰�ˡ�
-
-Sat Aug 24 23:56:37 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* bignum.c (bigdivmod): FIX2INT -> INT2FIX ��ְ㤤
-
-Fri Aug 23 18:13:03 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* regex.c (re_free_registers): allocate���Ƥ��ʤ����ˤ����� free 
-	  ���ƤϤ����ʤ���
-
-Thu Aug 22 01:20:35 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* eval.c (thread_create): ��¦���鶯����λ������줿thread��
-	  cleanup����ɬ�פ�̵����
-
-Wed Aug 21 09:57:28 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* eval.c (thread_create): thread��λ���������æ�Фξ����
-	  main_thread���Ϥ��褦�ˡ�
-
-	* parse.y (call_args): �ǽ������˳�̤��ά�����᥽�åɸƽФ�����
-	  ����褦��(��: print foo bar, baz == print(foo(bar,baz)))
-
-Tue Aug 20 13:37:16 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* eval.c (masign): ¿��������rest������ư����碌�ƶ����������
-	  ������褦�ˡ�
-
-	* parse.y (arg): defined?�ζ��٤�⤦����äȶ���
-
-	* eval.c (error_print): -w���㳰̾��ɽ������褦��
-
-	* eval.c (rb_eval): ����ʸ���б�
-	(handle_rescue): ��ª�����㳰�� kind_of? ��Ʊ��
-
-	* parse.y (primary): rescue�ι�ʸ���ѹ�(Ʊ��������ɲá�ʣ��rescue)
-
-	* Fail()�Τ��ʤ��Ŭ�����㳰��Ȥ��褦��
-
-	* eval.c (thread_interrupt): Interrupt(����non-local jump)��
-	  main-thread��������褦�ˡ�
-
-	* eval.c (rb_longjmp): $! �����Ƥ�ʸ���󤫤��㳰���饹���ѹ�
-	(rb_raise): rb_fail ����̾���ѹ�
-	(rb_interrupt): �㳰��
-	(rb_exit): �㳰��
-
-	* error.c (Init_Exception): �㳰���饹�ο���(ʸ����Υ��֥��饹)
-
-Mon Aug 19 19:40:52 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* signal.c (trap): �Ť��ϥ�ɥ���֤��褦�ˡ�
-
-Wed Aug 14 00:07:18 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* eval.c (rb_trap_eval): �ϥ�ɥ�Τ����thread��fork���뤳�Ȥ��
-	  �᤿��
-
-	* eval.c (thread_mark): thread��� $!, $@ ��ޡ�����˺��
-
-	* ext/dbm/dbm.c (fdbm_delete): ���ƥ졼���Ȥ��ƸƤФ줿��硤����
-	  ��̵����Х֥��å���ɾ�����롥
-
-	* hash.c (hash_delete): ���ƥ졼���Ȥ��ƸƤФ줿��硤���Ǥ�̵����
-	  �Х֥��å���ɾ�����롥
-
-	* array.c (ary_delete): ���ƥ졼���Ȥ��ƸƤФ줿��硤���Ǥ�̵����
-	  �Х֥��å���ɾ�����롥
-
-	* eval.c (rb_interrupt): SIGINT�Υǥե���Ȥ�exit�������̤����æ
-	  �Фˡ���Ϥ�����ޤ줿���֤�ɽ����̵���Τϼ䤷���Τǡ�
-
-Tue Aug 13 01:34:00 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* eval.c (rb_exit): sub-thread��Ǥ�exit��status����¸����褦��
-	(thread_create): ��thread���exit���б�
-
-	* signal.c (sighandle): SIGINT�Υǥե���ȥϥ�ɥ��exit����褦��
-	  (�������㳰��ȯ�����Ƥ���)��
-
-	* �㳰�ΰ�����Fatal�ˡ�
-
-	* string.c (str_aset): ʸ������ִ����оݤ���ʬʸ����Ǥʤ��ä�����
-	  �㳰��ȯ�������ʤ��褦��
-
-	* eval.c (proc_call): Proc���椫��break/next���̤���¾�Τ�Τ��̤�
-	  �ʤ��褦��
-
-Mon Aug 12 14:15:09 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* object.c (krn_type): ʸ������֤�
-
-	* eval.c (thread_create): sub-thread��Ǥ�exit���б�
-
-	* numeric.c (fix_type): ʸ������֤�
-
-	* io.c (f_p): �ǥХå��ѥǡ���ɽ���᥽�å�
-
-	* eval.c (f_missing): nil/TRUE/FALSE�����̰���
-
-	* string.c (str_inspect): Ĺ��ʸ�����û��ɽ����inspect��Ư����
-	  human readable string������������(re-generatable string ��������
-	  ̵���ʤä�)��
-
-Sat Aug 10 16:54:21 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* object.c (Init_Object): kernel/nil/false/true�Υ��饹̾���ѹ�(��
-	  ʸ����)��ruby������ץȤ��饢�������Ǥ��ʤ��褦�ˡ�
-
-	* eval.c (rb_eval): CONSTANT�Υ����������ñ�㲽��cref��Ȥ�ʤ���
-
-	* eval.c (f_eval): �ðۥ᥽�å���Ǥ�������ͤ��������ʤ�褦��
-
-Fri Aug  9 12:23:17 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* array.c (ary_concat): append -> concat String�˹�碌��
-
-	* parse.y (yylex): `$;'���Ȥ��ʤ��ä���
-
-	* array.c (ary_push_method): ʣ������������դ���褦�ˡ�
-	(ary_unshift): ʣ������������դ���褦�ˡ�
-
-	* io.c (io_popen): IO.popen��command pipe��������褦�ˡ�
-
-	* object.c (Init_Object): Kernel��Nil��ruby script���饢�������Ǥ�
-	  �ʤ��褦�ˡ�
-
-Thu Aug  8 01:21:47 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* object.c (f_integer): �����ؤ��Ѵ��ؿ�
-	(f_float): �¿��ؤ��Ѵ��ؿ�
-	(f_string): ʸ����ؤ��Ѵ��ؿ�
-	(f_array): ����ؤ��Ѵ��ؿ�
-
-	* bignum.c (big_to_i): FIXNUM���ϰϤǤʤ�����Bignum�Τޤ��֤��褦
-	  ���ѹ���
-
-Wed Aug  7 09:28:38 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* version 0.99.1-960807
-
-	* parse.y (mlhs): ��*foo = 1,2,3�ץ����פ�¿���������ǽ�ˡ�
-
-	* object.c (Init_Object): ���饹True/False��ruby script���饢����
-	  ���Ǥ��ʤ��褦�ˡ�
-
-	* object.c (nil_inspect): inspectɽ����"nil"��
-
-	* io.c (io_print): nil��print��nil�ˡ�
-
-	* object.c (nil_to_s): nil��ʸ����ɽ����""�ˡ�
-
-Tue Aug  6 01:12:32 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* dir.c (dir_s_open): file descripter��­��ʤ����ˤ�gc���Ƥ����
-	  ������open���Ƥߤ롥
-
-	* io.c (rb_fopen): ���٤Ƥ�fopen()�ˤĤ���file descripter��­���
-	  �����ˤ�gc���Ƥ���⤦����open���Ƥߤ롥
-
-	* ext/socket/socket.c (Init_socket): ������ɲá�
-
-	* sample/ruby-mode.el (ruby-indent-to): ����ǥ�ȸ�Υ����������
-	  ��Ĵ������������
-
-	* gc.c (gc): ����ߥ����å���Ԥ�ʤ�(C�����ɤ���ǰ¿�����
-	  malloc()���Ȥ��ʤ��ʤ�Τ�)��
-
-	* st.c (call_hash_func): signal��thread�ˤ�����ߤ��б���
-
-	* sig.h (DEFER_INTS): ����߶ػ߶�֤λ���
-
-	* eval.c (f_require): thread�ˤ��require�ζ�����б�(�ǽ��
-	  require����λ����ޤ�¾��thread���Ԥ�)��
-
-	* bignum.c (str2inum): 0x80000000���ͤ���ˤʤäƤ���
-
-	* sprintf.c (f_sprintf): ʸ����������������ñ�Ȥ�`%'���б�
-
-	* bignum.c (big_cmp): ��Ӥη�̤��դˤʤ�������ä���
-
-Mon Aug  5 10:58:13 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* process.c (proc_exec_v): �㳰�Υ�å�������ʬ����䤹����
-
-	* ext/dbm/dbm.c (fdbm_store): nil���Ǽ��������Ǥκ���ˤʤ�
-
-	* ext/dbm/dbm.c: �������򥭥�å��塥
-
-Sat Aug  3 01:52:52 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* eval.c (rb_fail): `fail'������̵���ǸƤФ줿������������`$@'����
-	  ¸����褦�ˡ�
-
-	* eval.c (f_fail): frame��Ĵ��
-
-Fri Aug  2 11:26:21 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* ext/socket/socket.c (bsock_setopt): val�Ȥ���TRUE/FALSE/Fixnum��
-	  �����դ���褦�ˡ�
-
-	* ext/socket/socket.c (Init_socket): SO_REUSEADDR����������ɲ�
-
-	* ext/md5/md5init.c: md5�⥸�塼��(���ʣ���ե����뤫��ʤ�⥸�塼
-	  ��Ǥ⤢��)
-
-	* ruby.h (Make_Data_Struct): Data: object��instance�ѿ��˳�Ǽ ->
-	  Data����Object��(Dir,Time,Proc,Thread,DBM)
-
-Thu Aug  1 11:38:44 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* ext/dbm/dbm.c (fdbm_store): value��ʸ����̵�������б�
-
-Wed Jul 31 10:53:42 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* ext/socket/socket.c (open_inet): htons��ɬ�פǤ��ä�
-	(tcpaddr): ntohl���Ѵ�����
-
-	* process.c (rb_proc_exec): execvp -> execv
-
-Tue Jul 30 17:48:33 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* eval.c: `$?'��thread local��
-
-	* Makefile.in (install): install����strip��Ԥ�
-
-	* configure.in: install����strip���
-
-	* configure.in: NEXTSTEP�б�
-
-	* version 0.99.1-960730
-
-Tue Jul 30 16:40:35 1996  SHIROYAMA Takayuki  <psi@fortune.nest.or.jp>
-
-	* dln.c (dln_load): NeXT dln(mach-o)�б���configure��̤�б�
-
-Tue Jul 30 09:46:51 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* process.c (f_system): ʣ��������Ȥ��褦��
-
-	* process.c (f_exec): ʣ��������Ȥ��褦��
-
-	* array.c (ary_append): ����(�ޤ���Enum)�����Ǥ��˲�Ū���ɲ�
-
-	* array.c (ary_plus): Enum�Ϥ������Ǥ��ɲ�
-
-	* file.c (file_s_open): File.open���ɲ�
-
-	* struct.c (struct_new): FIX2INT��˺��Ƥ���
-
-	* file.c (Init_File): exists? -> exist?
-
-	* object.c (obj_is_kind_of): is_kind_of? -> kind_of?, is_a?
-
-	* object.c (obj_is_instance_of): is_instance_of? -> instance_of?
-
-Mon Jul 29 16:40:02 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* parse.y (parse_regx): ��Ÿ����Ԥä���硤casefold�����꤬�Ǥ���
-	  ���ʤ��ä���
-
-	* object.c (true_type): TRUE/FALSE��type�������
-
-	* parse.y (read_escape): 3ʸ�������octal���б�(\0�Ȥ�)
-
-Fri Jul 26 00:31:45 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* array.c (ary_reverse_bang): in-place�������ȿž������
-	(ary_sort_bang): in-place��sort����
-	(ary_sort): sort����������֤��褦��
-	(ary_delete_at): ���ꤷ�����֤����Ǥ�������
-
-	* eval.c (rb_call): stack���������å������ϹԤ�ʤ��褦��
-
-	* error.c (Warning): �¹����warning��ɽ������Ƥ��ʤ��ä�
-
-	* eval.c (compile): �㳰ȯ����ʬΥ��
-
-	* eval.c (f_eval): �ѿ�rb_in_eval����������������褦��
-
-	* ext/dbm/dbm.c (fdbm_store): ��Ǽ����key��ʸ������Ѵ�
-
-	* eval.c (rb_call): ̵�ºƵ��Υ����å������æ�Ф�Ԥ�C method�ˤ�
-	  �б���������thread��stack���������å��롼�����ή�ѡ�
-
-	* parse.y (yylex): ��1������unary -/+��Ƚ�꤬�ְ�äƤ�����
-
-	* parse.y (yylex): unary +�ǿ�����;�פ��ɤ�Ǥ���(ex. +5 -> 55)
-
-Thu Jul 25 12:15:04 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* parse.y (yylex): ۣ��Ǥʤ��������Ф��Ʒٹ��Ф��Ƥ�����
-
-	* eval.c (iterator_p): �����ǸƤ�Ǥ���������̤��֤��褦�ˡ�
-
-	* parse.y: break/next/redo/retry�Υ᥽�åɲ���
-
-	* sample/ruby-mode.el (ruby-calculate-indent): nest�Υ����å��ߥ�
-
-	* sample/ruby-mode.el (ruby-parse-region): ͽ���Υ����å��򶯲�
-
-	* parse.y (primary): unless/until������
-
-Tue Jul 23 18:50:10 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* array.c (Array#empty?), Hash.c (Hash#empty?), ext/dbm/dbm.c (DBM#empty?):
-	  ����Ƚ��Ҹ�
-
-	* eval.c (f_unless): if�εդ򤹤륤�ƥ졼��
-
-	* eval.c (f_until): while�εդ򤹤륤�ƥ졼��
-
-	* parse.y: not��ͥ���̤�and/or���⤯
-
-	* parse.y (expr): `!'�������̤��ά����call�Ǥ�ͭ����
-
-Mon Jul 22 10:15:38 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* version 0.99-960722
-
-	* array.c (ary_print_on): OFS��NIL�����å����Դ���
-
-	* ruby.c  (load_file): ɸ�����Ϥ���Υ�����ץȤ����λ����б���
-
-	* ruby.c (proc_options): -w�Ǥϰ���̵���λ��ˤ�ɸ�����Ϥ��饹����
-	  �ץȤ�Ȥ�(-v�ǤϤ���˽�λ����)��
-
-	* array.c (ary_compact): nil�����Ǥ�������᥽�å�
-
-	* array.c (ary_nitems): nil�Ǥʤ����Ǥ������᥽�å�
-
-Sun Jul 20 00:51:53 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* ruby.c (proc_options): -w option���ɲ�
-
-	* parse.y: {}���Ĥ��Ƥ��ʤ����ˤ�Ÿ�����ʤ�ʸ�����
-
-Fri Jul 19 16:16:05 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* version 0.99-960719
-
-	* lib/find.rb: ������(prune�γ�ĥ�դ�)
-
-	* file.c (test_l): lstat��Ĵ�٤ʤ��Ȥ͡�
-
-	* eval.c (f_throw): ��2�������ά��ǽ�ˡ�
-
-	* parse.y (str_extend): {}�Υͥ��Ȥ��б�
-
-Thu Jul 18 18:25:46 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* version 0.99-960718
-
-	* parse.y (str_extend): ʸ������μ�Ÿ���� \" ' ` / ��ޤ�����Ǥ�
-	  ��褦�ˡ�
-
-Tue Jul 16 15:55:31 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* sample/ruby-mode.el (ruby-parse-region): ����ɽ����Υ���������
-	  ���б�
-
-	* version 0.99-960716
-
-Fri Jul 12 10:06:19 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* io.c (f_select): ������close check.
-
-	* ruby.c (load_file): #!�Ԥΰ��������å�����1�����˸���(�¤򤤤���
-	  DOS�����к�)
-
-Wed Jul 10 17:18:35 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* version 0.99-960710
-
-	* time.c (time_s_timegm/time_s_timelocal): ���֤���������᥽�å�
-
-Mon Jun 17 15:59:20 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* version 0.99-960617
-
-	* parse.y (yyerror): ���顼ɽ���δ�ά����
-
-Wed Jun 12 14:11:01 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* signal.c (rb_trap_exit): trap 0��thread�����������˽������롥
-
-Fri Jun  7 10:17:01 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* array.c/hash.c (indexes): ����1�����Υѥ������̵�������������
-	  ����`*ary'��ȤäƤ�餪����
-
-	* eval.c (thread_wait_threads): main_thread����λ��������¾��
-	  thread���Ԥ�(����Ū�ˤϽ�λ�����ʤ�)��
-	  (ruby_run): ¾��thread���ԤäƤ���֤˥����ʥ뤬�褿�顤��thread
-	  ������λ�����롥
-
-	* eval.c (rb_fail): �᥽�å�̾��`$!'�������ࡥ
-
-	* eval.c (thread_create): main_thread�Υ���ƥ����Ȥ������֤����
-	  ����礬���ä���
-
-	* process.c (f_sleep): ���֤���ꤻ����thread���ҤȤĤ����ʤ�����
-	  �ˤ��б���
-
-	* eval.c (thread_create): create�塤fn��ƤӽФ�����context switch
-	  ��������Ȱ㤦context��fn���¹Ԥ���Ƥ��ޤ��Х���
-
-Mon Jun  3 08:03:17 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* struct.c (struct_s_def): ���Фλ����ʸ���󡤥���ܥ�(FIXNUM)
-	  �����Dz�ǽ�ˤ�����
-
-	* ext/etc/etc.c (Init_etc): ��¤�Υ��֥������Ȥ�GC�����ݸ����
-
-	* error.c (rb_sys_fail): nil/FALSE������Ȥ��Ƽ����դ���褦�ˡ�
-
-Thu May 30 16:19:08 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* eval.c (thread_select): EINTR�����
-
-Wed May 29 11:04:51 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* eval.c (f_catch): catch/throw�����������
-
-Tue May 28 13:30:52 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* version 0.99-960528
-
-	* eval.c (thread_cleanup): main thread����λ�����¾��thread�⽪λ
-	  ���뤳�Ȥ����β���
-
-	* signal.c (trap): SIGINT�Υǥե���Ȥ�����ߥ�(������SIG_DFL�Ǥ�
-	  �ޤ����ä�)��ruby�ǤϤ����ȥϥ�ɥ뤷�ʤ��ȡ�
-
-	* eval.c (thread_interrupt): SIGINT��main_thread���㳰��ȯ��������
-	  �褦�ˡ�
-
-Mon May 27 15:13:31 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* eval.c (thread_status): thread�ξ��֤��֤��᥽�åɡ�thread�ν�λ
-	  ���Ԥ��ʤ���
-
-	* eval.c (thread_value): ����promise��������뤿��Υ᥽�åɡ�
-
-	* eval.c (thread_join): �ԤäƤ���thread���㳰�򵯤��������ˤϡ�
-	  join�������㳰��ȯ������褦�ˡ�
-
-	* eval.c (thread_create): thread�Ǥ��㳰��propagate���ʤ��褦�ˡ�
-
-Fri May 24 10:47:53 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* enum.c (Init_Enumerable): `size' as alias to the `length'
-
-	* eval.c (thread_save_context): `$@', `$!'�򥹥�å���˥����֡�
-
-	* eval.c (superclass): ���顼ɽ��������ڤˡ�
-
-Thu May 23 10:38:41 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* version 0.99-960523
-
-	* eval.c (superclass): ���顼���˥����ѡ����饹̾��(ʬ�����)ɽ��
-	  ����褦�ˡ�
-
-Wed May 22 19:48:42 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* parse.y (superclass): �����ѡ����饹�λ���Ҥ�`:'����`<'���ѹ���
-
-Tue May 21 09:27:59 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* lib/thread.rb: thread�򥵥ݡ��Ȥ��륯�饹(Mutex, Queue)��
-
-Mon May 20 09:39:49 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* time.c (time_cmp): ��ư���������ⰷ����褦�ˡ�
-	(time_minus): Time - Time����ư�����������֤��褦�ˡ�
-
-Fri May 17 15:40:10 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* process.c (rb_proc_exec): Thread�б�����exec��ľ����
-	  ITIMER_VIRTUAL��ꥻ�åȤ��롥
-
-Tue May 14 02:12:44 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* signal.c (sighandle): SIGINT���Ф��ƥǥե���Ȥ��㳰��ȯ��������
-	  �Τ��ᡤstatus 130��exit����褦�ˤ�����
-
-	* eval.c (thread_schedule): Thread�ΥХ��ϤۤȤ�ɤȤ줿�褦����
-
-Fri May 10 11:21:08 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* eval.c (thread_schedule): �桼����٥�Thread��ǽ����Ψ�ϤȤ⤫��
-	  �ܿ����Ϥ��롥���塤thread�֤��̿���ǽ���������ͽ�ꡥ
-
-Thu May  2 21:22:31 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* time.c (time_timeval): struct timeval��ľ���֤��褦��(static�ѿ�
-	  ��Ȥ�ʤ�)��
-
-Wed May  1 17:27:32 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* process.c (f_sleep): �����ʳ���time�����Ǥ���褦�ˡ�
-
-Thu Apr 25 08:19:15 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* file.c (file_s_dirname): �ե�����̾��"/"��ޤޤʤ�����"."���֤�
-	  �褦��(GNU dirname�λ���)��
-
-	* file.c (file_s_basename): �ޤ�nil��0��Ʊ���Ƥ��륽�������Ĥä�
-	  ������
-
-	* parse.y (exprs): ���顼�ꥫ�Х���ɲá�
-
-Wed Apr 24 15:51:05 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* string.c (str_chop_bang): CRLF�ξ��2 bytes��chop!����褦�ˡ�
-
-	* ext/socket/socket.c (tcp_svr_s_open): �ޤ�nil��0��Ʊ���Ƥ��륽��
-	  �����ĤäƤ�����
-
-Tue Apr 23 18:14:25 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* pack.c (pack_pack): "A/a"�ΥХ���;�פ�padding�����äƤ�����
-
-Thu Apr 18 13:02:11 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* configure.in: �������ƥ������¸�����̥ǥ��쥯�ȥ�˥��󥹥ȡ���
-	  ����褦�ˡ�
-
-	* parse.y (yyerror): ���顼ȯ�����˥��顼�ԤȤ��ΰ��֤�ɽ�������
-	  ���ˡ�
-
-Wed Apr 17 14:22:42 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* defines.h: SAFE_SIGHANDLE��̵����������������ϤǤ��ʤ��褦�ˡ�
-
-	* io.c (io_ungetc): ����ǽ��
-
-	* ruby.c (load_file): �ե����뤫����ɤ߹����������Ѥ�ä��Τ��б���
-
-	* parse.y (compile_file): �ե����뤫������Ϥ���������ɤ߹���Τ�
-	  �ߤ�ơ�gets��Ȥ����Ȥˤ�����
-
-Wed Apr 10 17:40:11 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* version 0.98
-
-Tue Apr  9 09:54:30 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* parse.y (iter_block): ���ƥ졼���֥��å��λ����᥽�åɸƤӽФ�
-	  �˸��ꡥʸˡ�����β���
-
-	* eval.c (rb_eval): ��Ｐ������ɽ������Ӥ�inline����
-
-	* eval.c (rb_eval): defined? �� �������(����)��ʸ������֤���
-
-	* node.h: NODE_BEGIN -> NODE_RESCUE, NODE_ENSURE��ʬΥ��
-
-	* eval.c (rb_eval): option -n/-p�Υȥåץ�٥�롼�פ�inlineŸ����
-
-	* parse.y (cond0): ��Ｐ���ʸ�������Ӥ��оݤȤ��ʤ�
-
-Wed Mar 27 12:33:54 1996  Tairo Nomura <tairo@hucom.tp.titech.ac.jp>
-
-	* defines.h: NeXT�б�
-
-Wed Mar 27 10:02:44 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* parse.y: ͽ�����ѹ� continue -> next
-
-Mon Mar 25 07:34:37 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* parse.y (parse_regx): o(once)���ץ������ɲá�
-
-Fri Mar 22 14:25:35 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* version 0.97d
-
-	* eval.c (dyna_var_defined): ưŪ���������ѿ�����������å��ѥ롼
-	  ����
-
-	* parse.y (gettable): eval()����Ǥ�ưŪ���������ѿ�(�����ͤ����
-	  �Ƥ�����)�θ��Ф˼��Ԥ��Ƥ�����
-
-Tue Mar 19 10:46:47 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* version 0.97c
-
-	* re.c (reg_s_new): compile����segmentation fault��
-
-	* parse.y (str_extend): ���Ĥ�eval����褦�ˡ�
-
-Wed Mar 13 11:00:42 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* parse.y (str_extend): ʸ������μ�Ÿ����������̵��������
-
-	* parse.y: ����ʥ��顼�ꥫ�Х�򳰤�����
-
-Tue Mar 12 12:30:20 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* eval.c (rescue): �ְ�ä�ensure�Ǥ��㳰����ª���Ƥ�����
-
-Wed Mar  6 12:11:03 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* parse.y (var_extend): �ѿ�Ÿ��"#{}"�ǡ�Ǥ�դμ���񤱤�褦�ˤ�
-	  ��������ǡ��ѿ���Ÿ���Ǥ�̵���ʤä���ä��ʤ���
-
-	* regex.c (init_syntax_once): `_'��word���ɲá�
-
-	* regex.c (re_compile_pattern): `\w',`\W'��Ƚ���syntax table���
-	  ���褦�ˡ�
-
-Tue Feb 27 10:15:32 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* object.c (obj_inspect): ɽ�����륤�󥹥����ѿ���̵�����ˤϡ�
-	  to_s��Ȥ���
-
-	* configure.in: dln�θ��Ф�ưŪ�ˡ�
-
-Mon Feb 26 19:55:33 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* ruby.c (readin): read(2)�ǰ��٤˥ե����뤬�ɤ߹���ʤ������б���
-
-Sat Feb 24 14:47:18 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* version 0.97b
-
-Fri Feb 23 11:26:02 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* class.c (rb_define_module): C�����������줿�⥸�塼���PATH��
-	  ����˺�졥ʸ���󲽤�core dump��
-
-	* eval.c (mod_include): ����ͤ�nil�ˡ�
-
-	* version 0.97a
-
-Thu Feb 22 21:03:42 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* array.c (ary_times): ������*ʸ����פ�join��Ʊ��Ư���򤹤�褦�ˡ�
-
-Wed Feb 21 11:18:09 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* configure.in : fileCount��cache��
-
-	* configure.in : Linux��ELF�Ķ���ưŪ�˸��ФǤ���褦��
-
-Tue Feb 20 11:18:09 1996  Mitsuhide Satou  <mit-sato@aries.bekkoame.or.jp>
-
-	* FreeBSD dynamic link���
-
-Fri Feb 16 08:50:01 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* object.c (obj_inspect): ���󥹥����ѿ�������ʤ����֥������Ȥ�
-	  ������ɽ�������褦�ˡ�
-
-Wed Feb 14 16:56:44 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* eval.c (rb_eval): ��Ｐ��`2..2'�ʤɺ�����Ωľ��˱��դ���Ω����
-	  �ѥ�����˥Х���
-
-Tue Feb 13 18:22:22 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* version 0.97
-
-Fri Feb  9 21:32:55 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* lib/tkscrollbox.rb: �����������tcl�������Ԥ���ruby<->wish����
-	  �פ��̿���̵��������
-
-Wed Feb  7 10:26:52 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* string.c (str_aref): index��unsigned int�ǤȤäƤ�����
-
-	* string.c (str_aref): �ϰϳ���index���Ф���nil���֤���
-
-	* parse.y (special_local_set): `$_'�����̵���˻Ȥ�줿�����б���
-	  �ؿ���variable.c�����ư��
-
-	* string.c (str_sub): �ִ����ϰ��֤��ְ�äƤ�����
-
-Tue Feb  6 16:17:31 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* sample/ruby-mode.el (ruby-parse-region): �����Ȥ��ɤ����Ф���
-	  ����
-
-Fri Feb  2 18:35:28 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* variable.c (lastline_get): `$_'��`$~'��Ʊ���褦��SCOPE���������
-	  �ѿ��ˤ�����
-
-Thu Feb  1 14:14:07 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* file.c: stat��cache���᤿��
-
-Wed Jan 31 07:13:08 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* eval.c (proc_s_new): proc�����yield��ƤФ줿����core dump����
-	  �������Ȥꤢ�����㳰��ȯ�������롥
-
-	* variable.c (rb_class2path): singleton class�����
-
-	* ext/etc/etc.c (Init_etc): struct_define�Υ����ߥ͡�����nil���ä�
-	  (0�Ǥʤ���Фʤ�ʤ�)��
-
-	* ext/marshal/marshal.c: TRUE/FALSE���Ǥ��Ф���褦�ˡ�
-
-	* eval.c (rb_get_method_body): ����å����alias�б������ޤޤǤ�
-	  alias�ϥ���å�������äƤ��ʤ��ä���
-
-Tue Jan 30 09:55:13 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* eval.c (rb_eval): NODE_BLOCK - tail recursive(�Ȥ����ۤɤǤ�ʤ�
-	  ��)��
-
-	* io.c (io_pipe): pipe(2)�����������
-
-	* eval.c (rb_eval): Qself��ʤ�������thread�б��ؤ�����⡥��ϱ�
-	  �����ġ�
-
-	* eval.c (proc_call): proc����Ǥ�return��proc�ν�λ���̣����褦
-	  �ˡ���������proc�����yield����Ǥ�return���㳰��ȯ�����롥
-
-Wed Jan 24 11:33:48 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* version 0.96a
-
-	* dir.c (dir_each): `$_'���ͤ��ѹ�����Τ��᤿��
-
-	* io.c (f_readlines): nil��FALSE��ʬΥ�Τ������̵�¥롼�פ������
-	  ������
-
-	* ruby.c (ruby_options): $0������ߥ���
-
-Tue Jan 23 15:28:21 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* eval.c (rb_eval): ``��ʸ���������Ȥ���᥽�å�(`)�ƤӽФ��Υ�
-	  �󥿥å������奬���Ǥ���Ȥ�����
-
-	* ruby.c (addpath): `-I'���ץ����ǥǥ��쥯�ȥ꤬�����ˡ��ɲä���
-	  ��褦���ѹ���
-
-Fri Jan 19 11:23:12 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* dln.c (load_1): N_INDR�б�(���褿�褦�ʵ�������)��
-
-Thu Jan 18 18:14:20 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* ruby.texi: FALSE��nil��ʬΥ��ȿ�Ǥ�����
-
-Tue Jan 16 17:39:23 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* version 0.96 - �Ȥꤢ����nil��FALSE����̤�����
-
-Wed Jan 10 15:31:48 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* re.c (reg_match): �ޥå����ʤ��ä���������ͤ�FALSE��
-
-	* object.c (rb_equal): `0 == nil'��TRUE�ˤʤ�Х���
-
-Tue Jan  9 00:44:58 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* nil��FALSE��ʬΥ��ǽ���ѹ���
-
-	* nil��FALSE��0�ζ��̤�̩�ˡ�
-
-	* struct.c (struct_new): ������0�ǽ���ɬ�פ�̵���ʤä���
-
-	* object.c (inspect_i): ���֥������ȤΥ����å��ΥХ�(Fixnum��core
-	  dump���Ƥ���)��
-
-	* range.c (range_to_s): Range��ɽ���������
-
-	* object.c (true_inspect): TRUE��ɽ����`TRUE'�ˡ�
-
-Mon Jan  8 15:02:33 1996  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* numeric.c (fix_mul): divide by zero error��ȯ������(�����С��ե���
-	  ���ФΥХ�)
-
-	* texinfo.tex��ѥå������˴ޤ᤿��
-
-Sun Dec 31 00:08:49 1995  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* eval.c (rb_eval): `::'�Ǥϡ����Υ��饹��������줿����򻲾Ȥ���
-	  �褦���ѹ���
-
-	* string.c (Init_String): each��each_line���ᤷ����
-
-Thu Dec 28 12:31:55 1995  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* eval.c (rb_eval): case�α黻�Ҥ�`=~'����`==='�ˡ�
-
-	* variable.c (rb_const_set): ���饹����κ���������(Ʊ�����饹��
-	  ���Բ�)���ٹ�ϽФ���
-
-Wed Dec 27 13:27:52 1995  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* version 0.95c
-
-	* ext/tkutil/tkutil.c: wish�����äƤ�ʤ��Ƥ�������ѥ��������
-	  ����褦�ˡ�
-
-	* lib/tk.rb: �Ķ��ѿ�PATH����{wish|wish4.0}��õ���褦�ˡ�
-
-Tue Dec 26 01:03:42 1995  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* sample/ruby-mode.el (ruby-parse-region): ����ɽ���θ��ж�����
-
-	* numeric.c (fix_mul): �軻�Υ����С��ե������Х��르�ꥺ��ΥХ���
-
-	* ext/extmk.rb.in: ./install-sh��Ȥ�����PATH��Ĵ����
-
-	* Makefile.in (install): lib/*.rb���Ĥ��ĥ��󥹥ȡ��롥
-
-	* io.c (io_each_line): ���ƥ졼��������ͤ�nil�����졥
-
-Fri Dec 22 10:34:32 1995  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* version 0.95b
-
-	* variable.c (f_untrace_var): ��2��������ꤹ��������trace����
-	  �Ǥ���褦�ˡ�
-
-	* variable.c (f_trace_var): ��2������nil�λ���trace�������롥
-
-	* lib/tk.rb (file_readable/file_writable): ��2������nil�ˤ��뤳��
-	  �ˤ��event handler�κ����
-
-	* parse.y (variable): �ɥ�����Ȥ�`__FILE__'��`__LINE__'���Ĥä�
-	  ������`caller(0)'�����Ѥ����Ϥ����ä��Τˡ�
-
-	* eval.c (f_eval): $!�Υꥻ�åȡ�
-
-	* error.c (err_sprintf): �����"\n"���ղä���Τ�ߤ᤿��
-
-	* parse.y (f_arglist): �����ꥹ��ľ���if/while���ɤߴְ㤤��
-	  lex_state���ͤ����ꤵ��Ƥ��ʤ��ä���
-
-Thu Dec 21 00:56:57 1995  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* version 0.95a - ^^;;;
-
-	* lib/tkscrollbox.rb: �ѥå����������äƤʤ��ä���
-
-	* configure.in: FILE structure�Υ����å��˥Х���
-
-	* Makefile.in (clean): ext�ʲ���install���Ƥ�����
-
-	* ext/socket/extconf.rb: Solaris�ˤ�����-lnls�Υ����å���
-
-	* array.c (beg_len): �Х������ä��ġ��ᤷ����
-
-	* version 0.95 - fj.sources��
-
-	* eval.c (rb_eval): rescue�Υ����å���rb_rescue()�˰층����
-
-Wed Dec 20 19:30:58 1995  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* Makefile.in: ���פʥ���ѥ���β���(��괰����)��
-
-	* class.c (singleton_class_new): `single'->`singleton'
-
-Tue Dec 19 07:14:33 1995  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* io.c (closed?): IO��close����Ƥ��뤫�ɤ������Τ�Ҹ졥
-
-	* parse.y (primary): �ðۥ᥽�åɤΰ�����lex_state����Ŭ�ڡ�
-
-	* lib/tk.rb: tcl->ruby���Ѵ��ؿ����Ѱա�
-
-	* ext/extmk.rb.in (install): install��2�ť���ѥ���β���
-
-	* array.c (range_beg_len): range�������Ŭ�ڤʥ��顼��������
-
-	* string.c (str_aref): range����ΥХ�������
-
-	* lib/tk.rb (tk_split_list): Tcl�Υꥹ�Ȥ��б���
-
-Mon Dec 18 09:58:12 1995  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* version 0.94
-
-	* dln.c (dln_load): HP�б�(̤��ǧ)
-
-	* eval.c (Init_Proc): Block��Proc�˲�̾��
-
-Sat Dec 16 13:46:14 1995  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* eval.c (rb_eval): retry�ǥ��ƥ졼���κƼ¹Ԥ��Ǥ���褦�ˡ�
-
-Fri Dec 15 17:14:30 1995  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* eval.c: proc:lambda�οƤ��ߤ䤹����̾
-
-Thu Dec 14 17:21:55 1995  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* eval.c (dyna_var_asgn): ���ƥ졼���֥��å���Ǻǽ�˽�������줿
-	  ���������ѿ���ͭ���ϰϤ򤽤Υ֥��å���˸��ꡥ�����lambda�ȸƤ�
-	  �ʤ����ȤϤʤ���
-
-Wed Dec 13 02:30:58 1995  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* gc.c: autoload�Υޡ����ߥ���
-
-	* lib/tk.rb: wish�����ʣ���Ԥ�����ͤ��б�
-
-	* lib/tkcomposite.rb: ʣ��widget
-
-	* variable.c (rb_class2path): ICLASS���б����Ƥʤ��ä���
-
-	* eval.c (ruby_run): exit(0)�ΥХ�
-
-Sat Dec  9 01:21:24 1995  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* ext/marshal/marshal.c (dumps|load): ʸ������Ф��������Ϥ��ǽ��
-	  ����(�������¤ϥե������ͳ�ʤΤ�)��
-
-Fri Dec  8 18:29:11 1995  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* ext/marshal/marshal.c: ����ܥ����٤�����������롥
-
-Thu Dec  7 07:58:50 1995  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* parse.y (yylex): ��1����������ɽ����ǧ���˥��顼�����ä���Ʊ����
-	  ���ֿ��򸺤餷����
-
-	* string.c (str_sub): �ִ��ǥ����å������礭��������
-
-Wed Dec  6 15:14:23 1995  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* string.c (str_sub_method): sub/gsub(!�ʤ�)���ִ����Ԥʤ��ʤ���
-	  �������ִ�����ʸ������֤���
-
-Tue Dec  5 00:55:15 1995  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* parse.y (yylex): ��̤��ά�������ΰ���Ÿ����`*'���б���
-
-	* eval.c (ruby_run): EXIT�ϥ�ɥ���Ǥ��㳰���б���
-
-	* bignum.c (big_cmp): Bignum��Fixnum����Ӥ�����롥
-
-Mon Dec  4 14:21:18 1995  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* parse.y (call_op): ����ѥ�������������Ÿ�����᤿��ϫ¿����
-	  �Ʊ׾��ʤ���Ƚ�Ǥ����Τǡ�
-
-Thu Nov 30 01:35:15 1995  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* lib/tk.rb: {Radio,Check}Button��variable�����
-
-	* eval.c (rb_yield_0): Block.call���ͥ��Ȥ������ΥХ���
-
-	* io.c (f_select): �������3�Ĥ�դ���������֤��褦��
-
-	* lib/tk.rb: fileevent��ruby¦�Ǽ�����
-
-Wed Nov 29 17:53:23 1995  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* variable.c (rb_ivar_get): self���˻��ꤹ��褦�ˡ�
-
-Tue Nov 14 00:07:29 1995  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* lib/tk.rb: Tk4.0�б�
-
-Mon Nov 13 16:23:32 1995  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* version 0.93
-
-Thu Nov  9 23:26:01 1995  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* gc.c (gc_mark): �⥸�塼���Mixin�Υޡ���˺�졥
-
-	* parse.y (f_arglist): �᥽�å�����ΰ������̤dz��ʤ��Ƥ��ɤ�
-	  �褦�ˤ�����
-
-Wed Nov  8 00:17:51 1995  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* eval.c (rb_yield_0): ̤������Υ��������ѿ������ä���
-
-	* eval.c (rb_eval): pendig signal�Υ����å���eval�¹Ը�˹Ԥ��褦
-	  �ˤ������Ǥʤ��ȥ����ʥ��ȯ���ȸ��Ф���Υ��Ƥ��ޤ��������롥
-
-	* parse.y: classʸ��superclass����������鼰�˳�ĥ������
-
-	* lib/tk.rb: Tk�Τۤ���������ɥ����饹���б��������Х��ȥƥ���
-	  �Ⱦ�Υ��֥������Ȥ��ĤäƤ��롥
-
-Tue Nov  7 08:18:37 1995  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* signal.c (trap): �֥��å������Ǥ���褦�ˡ�
-
-Mon Nov  6 16:44:00 1995  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* eval.c (f_caller): �ƽи��ξ�������롥
-
-	* ext/tkutil/tkutil.c: wish��stderr���Ϥ�ƻ뤹�뤳�Ȥǡ����顼��
-	  ����Ԥ���
-
-	* ext/tkutil/tkutil.c: wish�Ȥ��̿�����C�ǵ��ҡ�
-
-Sat Nov  4 01:12:59 1995  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* sample/ruby-mode.el (ruby-calculate-indent): ����ǥ�Ȥη׻���
-	  �⤦�������ޡ��Ȥˤ���(����ɽ���Υ����å�����³�ԤΥ����å�)��
-
-	* eval.c (rb_call): ̵�ºƵ����򤱤뤿�ᡤ�ؿ��Υͥ��ȥ�٥������
-	  ��Ԥʤ���
-
-	* lib/tk.rb: Tk���󥿡��ե��������ޤ��Դ���������
-
-	* eval.c (rb_yield_0): ����Block�ΥХ���
-
-	* sample/ruby-mode.el (ruby-calculate-indent): �����α黻�Ҥˤ��
-	  �Է�³���б���
-
-Fri Nov  3 12:56:21 1995  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* eval.c (rb_call): ���Τ����δؿ��μ¹Ԥ˥Х���
-
-	* parse.y (var_extend): ʸ������������ѿ�Ÿ���ΥХ���
-
-	* variable.c (rb_gvar_set): trace��ɾ�����ˤ��ѿ��ͤ�Ϳ����褦�ˡ�
-
-	* eval.c (f_require): ruby script��require��bug��
-
-	* variable.c (rb_const_get): �⥸�塼���include�к���
-
-Thu Oct 19 13:56:06 1995  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* dln.c (dln_load): HP�б��Ǥ�typo.
-
-Wed Oct 18 17:39:39 1995  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* version 0.92
-
-	* object.c (krn_type): ���֥������Ȥ�ưŪ�ʷ����֤��᥽�åɡ�
-
-Tue Oct 17 00:48:18 1995  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* ruby.c (proc_options): -X ���ץ����chdir������Ԥ���
-
-	* re.c (reg_search): ���������ɤ�������ѹ��Ǥ���褦�ˡ�����ѥ�
-	  ����Υ����ɤ��ѹ����줿���ˤϥޥå���ľ��������ɽ���κƥ���ѥ�
-	  ���Ԥ������KCODE�����ѿ�$KCODE�ء�
-
-	* parse.y: ()�Τʤ���compexpr�������
-
-	* re.c (reg_search): ����꡼����ľ������
-
-Fri Oct 13 13:19:19 1995  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* string.c (str_sub): ʸ�����ִ��˥Х���
-
-	* string.c (str_strip_bang): ʸ����θ����Ĺ����Ĵ�����Ԥ��Ƥ�
-	  �ʤ��ä���
-
-	* re.c (reg_search): $&, $1...�ϥ��������«������褦�ˤʤä�����
-	  �ӽФ����᥽�åɤǤΥޥå��ϸ��������פ�$&�ʤɤ��ͤ˱ƶ����ʤ���
-	  �ޥå��ξ���򥹥����׳����������Ȥ��ˤ�$~��Ȥä�«����������
-	  �Ф�ɬ�פ����롥
-
-Thu Oct 12 00:33:33 1995  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* re.c (reg_search): String:split, String:index�Ǥ�$&, $1...���Ѳ�
-	  ���ʤ��褦�ˤ�����
-
-	* io.c (rb_str_setter): setter�λ��ͤ��ѹ��ˤʤäƤ�����
-
-	* variable.c (f_trace_var): ��2�������ά���ƥ��ƥ졼���Ȥ��ƸƤ�
-	  ��褦�ˡ�
-
-Wed Oct 11 11:50:59 1995  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* version 0.91
-
-	* variable.c (var_setter): �������ְ�äƤ�������̿Ū�Х���
-
-	* io.c (pipe_open): $stderr���ͤ��ѹ�����Ƥ�����ˤϤ������
-	  �ҥץ�������stderr�����ꤹ�롥
-
-Mon Oct  9 13:06:33 1995  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* object.c (mod_to_s): �⥸�塼����Υ⥸�塼���`::'��Ȥä�ɽ��
-	  ��ɽ�������褦�ˡ�
-
-	* variable.c (rb_gvar_set): �����ˤ��롼�פ�ȯ�����ʤ��褦�ˡ�
-	  trace��Ǥ������Ǥ�trace��ɾ�����ʤ���
-
-	* struct.c (struct_equal): struct��equalȽ��˥��饹�ΰ��פ�ޤ᤿��
-
-Sat Oct  7 00:18:32 1995  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* eval.c (rb_eval): defined?�ε�ǽ���ĥ(yield�Υ����å���super��
-	  ¸�ߤʤ�)��
-
-Fri Oct  6 12:06:47 1995  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* version 0.90
-
-	* st.c (st_foreach): ���Ǥ��������������ǿ����Ѳ����Ƥ��ʤ��ä���
-
-	* hash.c (hash_values): �Х�������keys���֤��Ƥ����ġ�
-
-	* parse.y (call_op): defined? �ΰ����Ǥ�����ξ��߹��ߤ�Ԥ�ʤ�
-	  (�����å��������˥���ѥ��륨�顼�ˤʤäƤϺ���)��
-
-	* �������������ΰ�����ľ����
-
-Thu Oct  5 00:29:43 1995  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* �ؿ��ȥ��饹��̿̾��§���ѹ��������ؿ�̾���ѿ�̾�����̽񤭴�����
-
-	* gc.c (looks_pointerp): �ҡ��ץ����å��ι�®����
-
-	* struct.c (Fstruct_aset): ��¤�Τ��Ф���`[]='��
-	(struct_set): ��¤�Υ��Ф��Ф���������
-
-Wed Oct  4 09:54:07 1995  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* version 0.89
-
-	* eval.c (Frequire): �����ʥߥå������ɤΥ��顼�����å��򸷤�����
-
-	* struct.c: struct�ι�¤�����˽񤭴������������Ͻ���դ���
-	  id->value��Ϣ������Ǥ��ä��������٤Ϲ�¤����˿��������饹����
-	  ������褦�ˤ�����
-
-	* parse.y: `::'�ΰ�̣��Assoc���������饯�饹(�⥸�塼��)��������
-	  ���������ѹ���
-
-	* assoc.c: �ʤ�����
-
-Tue Oct  3 13:31:08 1995  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* variable.c (Ftrace_var): trace_var, ����ѿ��ؤν񤭹���hook����
-	  �ꤹ�롥
-
-	* variable.c: global_entry�ι�����񤭴������������trace_var���
-	  ���Ǥ��롥
-
-	* file.c (Ffile_stat): "&"��ľ����fstat�η�̤⻲�ȤǤ���褦�ˡ�
-
-Fri Sep 29 14:15:13 1995  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* version 0.88
-
-	* dln.c (dln_load): AIX��HP���б����������ɤ����줿(ư���̤��ǧ)��
-
-	* ext/extmk.rb.in: ɬ�פ˱����ơ����EXTLIB���������褦�ˡ�
-
-	* dln.c (dln_load): dln��Ω�˽񤭴����롥����γ�ĥ�ѡ�
-	(load_1): dln_a_out�ˤ����ƥ����������ɤǥ饤�֥�������Ū�˥���
-	�ɤ���ɬ�פ��ʤ��褦���ѹ�������
-
-Thu Sep 28 13:31:37 1995  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* sample/ruby-mode.el: ��äȤޤ���hilit19�б�(����ɽ��)��
-
-Wed Sep 27 04:12:44 1995  Takahasi Mamoru <taka@soum.co.jp>
-
-	* sample/test.rb: echo��-n��Ȥ�ʤ��褦��(SysV�к�)��
-
-	* ext/extmk.rb.in: sub -> sub!
-
-Tue Sep 26 19:12:42 1995  Yasuo OHBA  <jammy@csg.mes.co.jp>
-
-	* dln.c (dln_find_1): `.', `..'����Ϥޤ�ѥ����б�����. 
-
-Mon Sep 25 12:33:03 1995  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* version 0.87
-
-Sat Sep 23 10:00:18 1995  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* eval.c (Fmod_modfunc): �᥽�åɤ�private�ˤ���Ʊ�����ðۥ᥽�å�
-	  ���������᥽�åɡ��ѥå�����Ū�Ȥ����Υ⥸�塼���ѡ�
-
-Fri Sep 22 11:02:44 1995  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* lib/find.rb: find���󶡤���饤�֥��
-
-	* variable.c (rb_define_variable): hook�������ʬΥ��
-	(add_hook): 1�ѿ����Ф���ʣ����hook������Ǥ���褦�ˡ�
-
-Thu Sep 21 00:22:11 1995  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* string.c (Fstr_frozen): ʸ���󤬹����ԲĤ��ɤ���������å������
-	  ��᥽�åɡ�
-
-	* hash.c (Fhash_aset): key��ʸ����λ������������Ƥ��Ѳ����ʤ��褦
-	  �ˡ�dup����freeze���롥
-
-Wed Sep 20 16:12:44 1995  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* version 0.86
-
-	* ext/extmk.rb.in (have_header): ����å���˥Х���
-
-	* ext/extmk.rb.in (have_library): �����ν�����Ѥ�ä���
-
-Thu Sep 14 18:00:59 1995  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* object.c (obj_is_instance_of): is_member_of����̾���ѹ���
-
-	Wed Sep 13 15:44:35 1995  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* string.c (Fstr_tr_bang): �ϰϳ���ʸ�����Ф����Ѵ��Х���
-
-Tue Sep 12 14:27:58 1995  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* file.c (Sfile_expand_path): expand_file_name -> expand_path��̾
-	  ���ѹ���
-
-	* enum.c (Fenum_member): includes? -> member? ��̾���ѹ���
-
-	* string.c (Fstr_each_byte): String��ByteArray�Ǥ���Ȥ������ܤ����
-	  �ơ�each�������each_byte���ѹ����������ޤǤ�each��each_line�ǥ�
-	  �������Ǥ��롥
-
-Mon Sep 11 18:31:17 1995  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* file.c (cache_stat): �ե�����̾�Ȥ���"&"����ꤹ���ľ����
-	  stat(2)�η�̤�����Ѥ���褦�ˡ�
-
-Fri Sep  8 14:18:51 1995  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* ruby.texi: `!', `?'���б����ƥ��åץǡ��ȡ�
-
-	* parse.y: defined -> defined?
-
-	* file.c: FileOp�ΰ�ʸ���᥽�åɤ�ʤ�������ʸ���ƥ��Ȥ�test�᥽��
-	  �ɤˤޤ����롥
-
-	* parse.y (yylex): �ѿ�̾�θ����`?'��������Ҹ�᥽�åɤθ����
-	  `?'���ɲä��롥
-
-Thu Sep  7 20:01:33 1995  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* string.c: ʸ�������Ȥ򹹿�����᥽�åɤ�̾���ν����`!'���ղá�
-	  `!'��̵���С��������Ѱդ�����
-
-	* parse.y: �ѿ�̾�θ����`!'�������
-
-Wed Sep  6 14:12:19 1995  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* version 0.85
-
-	* string.c (Fstr_dup): ʸ�����ʣ������
-	(Fstr_freeze): ʸ����ι����Բ�°��������Ǥ���褦�ˡ�
-	(Fsub/Fgsub): $_�����Ƥ�dup���Ƥ����ִ���Ԥ��褦�ˡ�
-
-	* ruby.h (CLONESETUP): flags�ξ��֤⥳�ԡ�
-
-Tue Sep  5 01:27:50 1995  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* sample/test.rb: ���Ԥθ��Ф򸷤�����
-
-Fri Aug 25 14:31:02 1995  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* process.c (Ffork): ���ƥ졼���Ȥ��Ƥ�ư���褦�ˡ�
-
-	* version 0.84
-
-	* signal.c (sig_beg): �ϥ�ɥ餬���ꤵ��Ƥ�����ˤϺ����ꤷ�ʤ���
-
-	* ext/extmk.rb.in (create_makefile): shared object�Υ�󥯤κݤ�
-	  `-l'���ץ�������ꤹ��褦�ˡ�
-
-	* signal.c (trap): `EXIT'�ǽ�λ������Ԥ����꤬����롥
-
-Wed Aug 16 00:13:22 1995  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* signal.c (sig_beg): �ǥե���ȤǤ�begin�����Ǥ���SIGINT����ª
-	  ����褦���ѹ���
-
-	* io.c (io_ctl): fcntl������ʤ������ƥ�ˤ��б���
-
-	* �ƥǥ��쥯�ȥ��ʬ�����Ƥ���MANIFEST��ޤȤ᤿����ĥ�⥸�塼����
-	  �ˤ�ɬ�ס�
-
-	* string.c (Sstr_new,str_sub,Fstr_crypt): ������ưŪ��ʸ�������
-	  ������褦�ˡ�
-
-Sat Aug 12 00:44:02 1995  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* string.c (Fstr_crypt): PD crypt���Ѱդ�����
-
-Fri Aug 11 14:37:03 1995  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* assoc.c (Fassoc_clone): assoc��clone�Ǥ���褦�ˡ�
-
-	* io.c: �ޥ���READ_DATA_PENDING��������ѹ�(Linux�б�)
-
-	* io.c (io_fptr_finalize): fptr�γ������ν��������Ǥ���褦�ˡ�
-
-Wed Aug  9 16:52:41 1995  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* eval.c (rb_provided): ʣ����feature������ɤ����̵�¥롼�פ���
-	  ����Ȥ���ñ���(������������)�ߥ���
-
-	* ext/extmk.rb.in (install): dlopen�б���Ԥä������ޤ�dln�ˤ�����
-	  ʬ���б����Ƥ��ʤ��ä���
-
-Tue Aug  8 14:17:06 1995  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* version 0.83
-
-Mon Aug  7 12:47:41 1995  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* parse.y: resque -> rescue���Ѥ���������typo��Ĥ��Ƥ����櫓�ˤ�
-	  �����ʤ���ʤ����ʤ�Ǻ��ޤǵ����Ĥ��ʤ��ä��Τ��ġ�
-
-Thu Aug  3 18:18:05 1995  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* missing/nt.c: NT�ܿ��Ѥδؿ�����ޤȤ᤿��
-
-	* variable.c (rb_const_get): �ޤ��㳰��ȯ������褦�ˤ�����defined
-	  ������ʾ��㳰��ȯ�������ʤ���ͳ���ʤ��Τ�(�㳰��ȯ������������
-	  ���ץߥ��θ��Фʤɤ�����ͭ��)��
-
-	* variable.c (Fautoload): autoload����������٤ϻȤ��뤫��
-
-Mon Jul 31 15:44:21 1995  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* parse.y (arg_ambiguous): ��1�����Τ����ޤ�����ٹ�(-v���ץ����
-	  ��ͭ��)��
-
-	* eval.c (rb_eval): `-v'���ץ�����Ĥ���`def'���ƤФ�����ɬ��
-	  �ʥ��顼��å��������Ф���
-
-	* parse.y (yylex): �᥽�åɤ���1������Ƚ���⤦����äȸ���������
-
-Fri Jul 28 19:04:43 1995  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* parse.y (yylex): `+/-/['��ľ���˶�����뤫�ɤ�����ư����ѹ���
-	  ��(����Τ�Ȥ�?)
-
-Wed Jul 26 09:21:23 1995  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* version 0.82a
-
-	* sprintf.c (Fsprintf): `%s'��'\0'��ޤ�ʸ������б���
-
-	* pack.c (Fpck_pack): pack�����dz��ݤΥХ���
-
-	* eval.c (Floop): ̵�¥롼�פΥ��ƥ졼����
-
-	* io.c (next_argv): ¸�ߤ��ʤ��ե�����̾�����ꤵ�줿���Υ��顼����
-	  ���Ԥ��Ƥ��ʤ��ä���
-
-Mon Jul 24 17:37:34 1995  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* version 0.82
-
-	* ext/extmk.rb.in (install): ��ĥ�⥸�塼���static link�������
-	  ���Υ⥸�塼�뤬����require���줿�Τ�Ʊ���褦��feature�����ꤹ�롥
-	  ����dz�ĥ�⥸�塼��ε�ǽ��ɬ�פʻ��ˤ�(static link����Ƥ��뤫
-	  �ɤ����ˤ�����餺)require����Ф褯�ʤ롥
-
-	* eval.c (Frequire): `$"'�˳�Ǽ����ʸ�����ե�ѥ��Ǥʤ��ե�������
-	  ̾�Ȥ��롥ruby������ץȤ�����ɤ������ˤ�`.rb'�����֥������Ȥ�
-	  �����ɤ������ˤ�`.o'��ե�������̾���ղä��롥lisp��require��
-	  provide��Ư����(����)�ᤤ��
-
-Thu Jul 20 12:50:05 1995  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* Makefile.in (test): make test���Ǥ���褦�ˡ�
-
-	* struct.c (struct_new): typo.
-
-	* eval.c (rb_eval): `defined'���ɲá��᥽�å�/�ѿ�/������������
-	  ���Τ��������롥
-
-Wed Jul 19 18:04:01 1995  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* version 0.81
-
-Mon Jul 17 14:53:51 1995  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* variable.c (rb_const_get): ̤�������CONSTANT���ͤ�nil�ˤ�������
-	  ����������ޤ��㳰���᤹��ǽ���Ϥ��롥�פ�optional�ʥ��饹/�⥸�塼
-	  �뤬¸�ߤ��뤫�����å������������ʤ���ʡ�
-	  
-	* st.c (int): grow_factor�����ˤ���(���褵��Υޥ�����б�)��
-
-Fri Jul 14 00:48:40 1995  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* ext/extmk.rb.in: ����å���ΥХ�������
-
-	* parse.y (var_extend): #{$����}���������
-
-	* dln.c (dln_load_1): `Init_FILENAME'������ͭ���ˡ�`init_*'�Ϻ���
-	  �¹Ԥ��ʤ���
-
-	* ext/etc/etc.c : Etc�⥸�塼����ĥ�⥸�塼��Ȥ���ʬΥ���¤�NT
-	  �б��ؤ����Ф��ä��ꤹ�뤫�⤷��ʤ���
-
-Tue Jul 11 17:12:48 1995  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* gcc -Wall�ǽФ�warning�򸵤˥��������ѹ���
-
-	* signal.c (trap): typo.
-
-Fri Jul  7 10:08:51 1995  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* version 0.80
-
-	* ruby.texi: texinfo document���󶡡�spec��ruby.1��̵���ʤä���
-
-	* signal.c (Ftrap): ����߶ػ�����㳰ȯ�����б���
-
-	* eval.c (Flambda): Block���֥������Ȥ��֤���Block.new��Ʊ����
-
-Thu Jul  6 00:35:03 1995  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* signal.c (Ftrap): SIG_DFL�ν������ѹ���SIGINT�ؤΥǥե���ȥϥ�
-	�ɥ���Ѱ�(�㳰��ȯ������)��
-
-	* file.c (Sfile_expand_fname): �ѥ�̾�����Хѥ���Ÿ������᥽�åɡ�
-	(Sfile_basename): basename������᥽�åɡ���ĥ�Ҥ⳰���롥
-	(Sfile_dirname): basename��ȿ�С�
-
-	* eval.c (rb_call): argumentɾ������㳰ȯ�����б���
-
-	* file.c (Ftest): `M', `A', `C'���ɲ�.
-
-Tue Jul  4 12:36:33 1995  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* file.c (Ftest): �ե�����ƥ����ѥ᥽�åɡ�
-
-	* ruby.c (proc_options): `-r'���ץ������ɲá�
-
-	* parse.y (f_args): �ǥե���Ȱ������ɲá�
-
-	* eval.c (rb_call): �������������̵������rest�������ͤ�nil�ˡ�
-
-	* numeric.c (num_equal): ���Ͱʳ��Ȥ���Ӥ��㳰��ȯ�����Ƥ�����
-	  FALSE���֤��褦�ˡ�
-
-	* eval.c (masign): ¿��������rest����ư����������ä���
-
-Sat Jun 17 01:03:16 1995  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* parse.y (gettable): ̤������Υ��������ѿ��λ���(��Ω�������̻�)
-	  �������˥᥽�åɸƤӽФ��Ȥ�����
-
-	* parse.y (read_escape): tokenbuf��Ȥ�ʤ��褦�˽���������ˤȤ�
-	  �ʤ���`\C-x',`\M-x'�ʤɤΥ���������ɽ�������补����ǥɥ�����
-	  �Ȥȼºݤν����Ϥ����פ�����
-
-Thu Jun 15 15:42:00 1995  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* re.c (re_regcomp): cache�Υ����å��������
-
-Mon Jun 12 18:50:51 1995  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* version 0.79
-
-Sat Jun 10 00:25:01 1995  Yukihiro Matsumoto  <matz@caelum.co.jp>
-
-	* re.c (re_regcomp): cacheȽ���`$='���ͤ�ȿ�Ǥ�������
-
-	* sample/test.rb: test suite������
-
-Fri Jun  9 15:58:34 1995  Yukihiro Matsumoto  <matz@ix-02>
-
-	* re.c (re_regcomp): cache��Ƚ�꤬�ְ�äƤ�����
-
-Fri Jun  9 00:01:35 1995  Yukihiro Matsumoto  (matz@dyna)
-
-	* eval.c (rb_yield): block��¤�Τ˽�������Ƥ��ʤ�����(iter)������
-	  ���Τǥ��ƥ졼���Υͥ��Ȥ�������ư��ʤ��ä���
-
-Thu Jun  8 00:59:03 1995  Yukihiro Matsumoto  (matz@dyna)
-
-	* re.c (=~): String�ʳ��Ȥ���Ӥ�FALSE���֤��褦��(�㳰��ȯ������
-	  ����)��
-
-	* extmk.rb.in: Ƚ�ꤷ���ͤ�ե�����˥���å��夹��褦�ˤ�����
-
-	* assoc.c (to_a): to_a�᥽�åɤ����������Ƥ��ʤ��ä���
-					 
-	* eval.c (rb_eval): ���������Ƥ��ʤ����������ѿ��ؤΥ����������
-	  ����̵���᥽�åɸƤӽФ��Ȳ�᤹�롥��������(�����Ǥ�)�᥽�åɤ�
-	  �������Ƥ��ʤ���硤���顼�ˤ����ѿ�̤�������waring��Ф���
-	  nil���֤��Ƥ��롥��ruby -pe print�פʤɤ��¹ԤǤ���Ȥ�����̣��
-	  �Ϥ��꤬�������λ��ͤϡ�����������θ�Ƥ��ɬ�פǤ��롥-- �᥽��
-	  �ɸƤӽФ��Ȥ���Τ�ߤ�뤫(�����λ���)�����Ĥ�᥽�åɸƤӽФ�
-	  �Ȥ���(̤����ʤ�Х��顼)�������λ��ͤǹԤ�����
-
-	* eval.c (rb_eval): ���������Ƥ��ʤ����������ѿ��ؤΥ���������
-	  (eval�ʤɤ�)��������줿����ʬ���ä����ˤϰʸ��������줿������
-	  ���ѿ��Ȥߤʤ���
-
-Wed Jun  7 11:58:12 1995  Yukihiro Matsumoto  <matz@ix-02>
-
-	* eval.c (rb_fail): �㳰�������`$!'�򥯥ꥢ���ʤ��褦�ˡ�
-	  (rb_fail): `$!'�ѿ��˺Ǹ�˲��Ԥ��ɲä��ʤ���
-
-	* io.c (Fprint): private�᥽�åɤ��ѹ�����������ʤ�����ư�����
-	  ��(`$_'����Ϥ���)��
-	  (Fio_print): ����������print�᥽�åɡ�
-	  (Fio_printf): ����������printf�᥽�åɡ�
-
-	* parse.y: not�黻�Ҥ��ɲá�ͥ���̤��㤤`!'�黻�ҡ�
-
-Mon Jun  5 19:00:55 1995  Yukihiro Matsumoto  <matz@ix-02>
-
-	* version 0.78
-
-Fri Jun  2 17:52:03 1995  Yukihiro Matsumoto  <matz@ix-02>
-
-	* ruby.c (proc_options): -I���ץ�����`$:'�ؤ��ɲä������֤�
-	  ��������
-
-Fri Jun  2 00:36:34 1995  Yukihiro Matsumoto  (matz@dyna)
-
-	* parse.y: while�����Ҥ�ư����̾��while��Ʊ���ˤ�������������
-	  begin���ؤ�while�����Ҥ�����do..while���Υ롼�פȤʤ롥
-
-Wed May 31 18:36:30 1995  Yukihiro Matsumoto  <matz@ix-02>
-
-	* version 0.77
-
-Mon May 29 18:39:37 1995  Yukihiro Matsumoto  <matz@ix-02>
-
-	* ext/extmk.rb.in (install): ��ĥ�⥸�塼��⥤�󥹥ȡ���Ǥ����
-	  ���ˡ�
-
-Fri May 26 14:43:01 1995  Yukihiro Matsumoto  <matz@ix-02>
-
-	* process.c (Fsystem): ����ͤ򥵥֥ץ������μ���/������ɽ��������
-	  �ˤ�������λ���ơ�������`$?'�����롥
-
-Tue May 23 10:58:11 1995  Yukihiro Matsumoto  <matz@ix-02>
-
-	* string.c (Fstr_upto): ̵�¥롼�פ˴٤�ʤ��褦�ˡ�
-
-	* parse.y (cond): `||'�ʤɤα��դ����漰���񤱤�褦�ˡ���Ｐ����
-	  �ʤ餺�����ͤ�����ʤ��Ƥ��ɤ��褦�ˤ�����
-
-	* ext/marshal/marshal.c: ���֥������Ȥ��ɤ߽񤭤�᥽�åɤκ����
-	  �ǥ���ȥ�����Ǥ���褦�ˡ����󥹥��󥹤�`_dump_to'�Ȥ����᥽��
-	  �ɤ�������Ƥ�����Ϥ������Ȥ��褦�ˡ�
-
-	* ext/extmk.rb.in: static link������Ǥ���褦�ʻ��ͤˤ�����
-	  ext/Setup�Ȥ����ե�����˥ǥ��쥯�ȥ�̾�򵭽Ҥ���Ȥ��Υǥ��쥯
-	  �ȥ��¸�ߤ���⥸�塼���static link�����(�Ϥ�)��
-
-	* eval.c (rb_eval): `..'��ʸˡ���Ȥ߹��ߡ�`..'��`...'��ư���perl
-	  �˹�碌����
-
-Sat May 20 01:22:48 1995  Yukihiro Matsumoto  (matz@dyna)
-
-	* io.c (select): timeout���ȳ���߻���ư������β���
-
-Fri May 19 15:33:23 1995  Yukihiro Matsumoto  <matz@ix-02>
-
-	* version 0.76
-
-Fri May 19 00:48:08 1995  Yukihiro Matsumoto  (matz@dyna)
-
-	* string.c (Fstr_each): ���ƥ졼���֥��å����ʸ������ѹ����Ԥ��
-	  �����ɤ���������å����ݥ��󥿤��ͤ��Ѥ�äƤ�����㳰��ȯ�����롥
-
-	* ruby-mode.el: ruby-electric-brace�ο��ߡ�
-
-Thu May 18 12:27:23 1995  Yukihiro Matsumoto  <matz@ix-02>
-
-	* string.c (Fstr_tr): tr���ִ��оݤ�`\0'��ޤ�����������ִ���Ԥ�
-	  �ʤ��Х������ä��������ִ�ʸ�����ASCII��˻��ꤷ�ʤ���ư���
-	  ������⤢�ä�����̤Ȥ���tr��񤭴������Τǡ�copyright�������
-	  ̵���ʤä�(�Ȼפ�)��
-
-	* gc.c (gc): the_scope��ޡ������Ƥ��ʤ��ä��Τǡ����������ѿ��λ�
-	  ���Ƥ��륪�֥������Ȥ��ְ�äƳ���������礬���ä���
-
-	* gc.c (mark_locations_array): �㴳�ι�®����
-
-Mon May 15 11:43:49 1995  Yukihiro Matsumoto  <matz@ix-02>
-
-	* ext/extmk.rb.in: Dynamic Load�⥸�塼��Υ���ѥ����ѥ����å���
-	  �Ԥ�ruby script��autoconf�˶ᤤ���ФǻȤ��롥�������⥸�塼���
-	  �󶡤������ͤ�ext�β��˥ǥ��쥯�ȥ����������ɤ���ɬ�ܤΥե�
-	  ����ϥե�����̾�ΰ�����Ͽ����`MANIFEST'�Ȥ����ե�����Τߡ�ɬ
-	  �פ˱�����`depend'(�ե�����ΰ�¸�ط��򵭽Ҥ���ե����� gcc -MM
-	  �ν���)��`extconf.rb'(����ѥ����Ѥ˥饤�֥��ȴؿ���¸�ߥ�����
-	  ������ե�����)���ѰդǤ��롥
-
-	* eval.c (rb_call): ruby�᥽�åɤΰ��������å�����̤�������
-	  jmp_buf����Ѥ��Ƥ�����
-
-	* parse.y: `or'��`and'��ͥ���̤�Ʊ���ˤ�����
-
-Wed May  3 18:21:36 1995  Yukihiro Matsumoto  (matz@dyna)
-
-	* dln.c: Linux�Ǥ�`__.SYMDEF/'�Ǥ��ä���
-
-	* dln.c: system call�Υ��顼�����å���˺��Ƥ�����
-
-Wed Apr 26 09:50:56 1995  Yukihiro Matsumoto  (matz@ix-02)
-
-	* parse.y: ���ƥ졼���֥��å����ѿ������`|'�dz��褦�ˤ���������
-	  �ǥ��ƥ졼���ѿ����ʤ�����������Τ�Τ��ά�Ǥ��롥ʸˡ���ѹ���
-	  �פ��֤����
-
-Tue Apr 25 12:04:17 1995  Yukihiro Matsumoto  (matz@ix-02)
-
-	* eval.c(require): load��������ʥߥå������ɤε�ǽ��ܤ��Ƥ�����
-	  ����˳�ĥ�Ҥ��䴰��ǽ���ɲä��ƥ桼����dln/dlopen�κ���ռ�����
-	  ɬ�פΤʤ��褦�ˤ�����
-
-	* string.c(sub,sub): ���ƥ졼���Ȥ��Ƥ�ư���褦�ˡ�
-
-	* object.c: init_object -> initialize.
-
-Mon Apr 24 14:22:39 1995  Yukihiro Matsumoto  (matz@ix-02)
-
-	* NEWS-OS 3.4�б�
-
-	* io.c: Solaris��stdio��ư��㤦�褦����signal��EOF���֤��Ƥ���
-	  ���ġ�perl�Ǥ�Ʊ�ͤ����꤬���롥
-
-Fri Apr 21 20:04:39 1995  Yukihiro Matsumoto  (matz@ix-02)
-
-	* version 0.75
-
-	* signal.c: trap���ʤ��ʤäƤ����������ࡥ
-
-	* configure: Solaris 2.3���
-
-	* io.c: #elif�Τʤ�cpp�⤢�롥
-
-	* dir.c: autoconf 2.x�ؤ��б����Խ�ʬ
-
-Thu Apr 20 12:31:24 1995  Yukihiro Matsumoto  (matz@ix-02)
-
-	* version 0.74
-
-	* env.h, gc.c, regex.c: IRIX�ؤΰܿ��б�
-
-	* configure: dlopen�Ѥ�pic����������option�θ��ФΤ��ᡤ�����ƥॿ
-	  ���פ�����å�����褦�ˡ�
-
-Tue Apr 18 19:08:17 1995  Yukihiro Matsumoto  (matz@ix-02)
-
-	* gc.c(xrealloc): ptr=nil�λ���malloc()��Ʊ��Ư����
-
-	* array.c(astore): ���������0���ܤ����Ǥ����������size=0��
-	  realloc()��Ƥ�Ǥ�����
-
-	* configure, glob.c: Solaris 2.x�ǥ���ѥ���Ǥ���褦��
-
-Mon Apr 10 18:36:06 1995  Yukihiro Matsumoto  (matz@ix-02)
-
-	* version 0.73
-
-Fri Apr  7 13:51:08 1995  Yukihiro Matsumoto  (matz@ix-02)
-
-	* cons.c->assoc.c: cons��;�פʵ�ǽ�ϳ�����pair�Ȥ��Ƥε�ǽ������
-	  �Ĥ�����Enumerable��include����Τ��᤿��
-
-	* string.c(esub): ʸ�����ִ����ƥ졼����perl��s///e���������롥
-
-Wed Apr  5 11:35:21 1995  Yukihiro Matsumoto  (matz@ix-02)
-
-	* version 0.72
-
-	* EWS4800�б�
-
-	* file.c: utimes���ʤ�����utime��Ȥ��褦�ˡ�
-
-Mon Apr  3 15:19:41 1995  Yukihiro Matsumoto  (matz@ix-02)
-
-	* version 0.71
-
-	* regexp.c(re_match): �Х������ä���match_2������������enbug����
-	  �����Τ��ä���
-
-Mon Mar 27 15:41:43 1995  Yukihiro Matsumoto  (matz@ix-02)
-
-	* dict.c: Dict->Hash������Ū�˰ܹԡ�
-
-Thu Mar 23 20:30:00 1995  Yukihiro Matsumoto  (matz@ix-02)
-
-	* dbm.c,socket.c: ext�ǥ��쥯�ȥ��ʬΥ��
-
-	* configure: dln����Υ����å��ζ���
-
-	* dln.c: init�θƤӽФ���dlopen()�Ǥ˹�碌����
-
-Mon Mar 20 17:45:08 1995  Yukihiro Matsumoto  (matz@ix-02)
-
-	* configure: autoconf 2.2���б�(����)��
-
-Fri Mar 17 15:56:44 1995  Yukihiro Matsumoto  (matz@ix-02)
-
-	* dln.c: dlopen�Τ���ޥ���ǤϤ������Ȥ��褦�ˡ��������������
-	  ��ư���Ƥ��뤫�ɤ����ϼ������ʤ���
-
-	* regex.c: virtual concatination���᤿��
-
-Thu Mar 16 11:32:57 1995  Yukihiro Matsumoto  (matz@ix-02)
-
-	* version 0.70
-
-	* eval.c,regex.c: gcc�ǤΥ���ѥ��륨�顼��
-
-	* io.c: inplace-edit�dz�ĥ�Ҥ����ꤵ��ʤ���硤��ȤΥե�������
-	  �����롥
-
-Wed Mar 15 14:59:18 1995  Yukihiro Matsumoto  (matz@ix-02)
-
-	* version 0.69
-
-	* eval.c(method_missing): unknown����̾���ѹ���
-
-	* eval.c(single_method_added): �ðۥ᥽�åɤ�������줿���˸ƤФ�
-	  ��᥽�åɡ�hook�Ȥ��ƻȤ��롥�ºݤ���������ľ���˸ƤФ�롥
-
-Tue Mar 14 14:46:44 1995  Yukihiro Matsumoto  (matz@ix-02)
-
-	* ruby.c(proc_options): �����β��Ϥ�ʬ�Ǥ�뤳�Ȥˤ����������
-	  ��ˡ��perl�˶��դ�����getopt_long�Ϥ⤦�Ȥ�ʤ���
-
-	* dir.c(glob): `{}'�Υͥ��Ȥ�����褦�ˤ�����
-
-Mon Mar 13 17:56:25 1995  Yukihiro Matsumoto  (matz@ix-02)
-
-	* glob.c: Glob(�磻��ɥ����ɥ��֥�������)�Ϥʤ��ʤä����磻��ɥ���
-	  �ɤ�Ÿ����Dir.glob(ʸ����)��Ȥ����磻��ɥ����ɤΥޥå�������ɽ
-	  �������ѡ�
-
-Fri Mar 10 18:35:46 1995  Yukihiro Matsumoto  (matz@ix-02)
-
-	* eval.c: Math�Τ褦�ʥ⥸�塼��ϼ�ʬ���Ȥ�extend���롥
-
-	* eval.c: ���饹��⥸�塼�����������������Ʊ̾�Τ�Τ��������
-	  ������Ȥʤ�褦�ˡ���������super���饹�ΰ㤤�ʤɤϥ����å����롥
-
-	* regex.c: debug.
-
-	* math.c: ���PI��E�������
-
-Thu Mar  9 21:35:12 1995  Yukihiro Matsumoto  (matz@ix-02)
-
-	* regex.c: EUC,SJIS�⡼�ɤǤ�0x80�ʾ��8�ʡ�16�ʥ�ƥ���ػߡ�
-
-	* regex.c: ���饹��Ǥ���ͥ�ƥ�롦ʸ�����饹���Ȥ���褦������
-
-Wed Mar  8 17:39:05 1995  Yukihiro Matsumoto  (matz@ix-02)
-
-	* regex.c: \200�ʤɳ�̤ο��ʾ��ɽ����8�ʥ�ƥ��Ȳ�᤹�롥����
-	  ����\1����\9�ޤǤ��㳰��
-
-	* regex.c: \9�ʾ�Υ�ե���󥹤�ͭ���ˤ�����
-
-Tue Mar  7 14:26:01 1995  Yukihiro Matsumoto  (matz@ix-02)
-
-	* eval.c(public/private): ������������᥽�åɤ�̾���ѹ�����Ū�ʥ�
-	  ������������褦�ˤ��Ƥߤ������Ժ��ѡ�
-
-Mon Mar  6 19:34:32 1995  Yukihiro Matsumoto  (matz@ix-02)
-
-	* eval.c(inlcude): �᥽�åɲ���ưŪ�˥⥸�塼��򥤥󥯥롼�ɤǤ�
-	  ��褦�ˡ������Ǥ�դΥ��֥������Ȥˤ�⥸�塼��򥤥󥯥롼�ɤ�
-	  ����᥽�å� `extend'���Ѱդ�����
-
-	* parse.y: ʸˡ����include�������᥽�åɲ���
-
-Tue Feb 28 15:35:10 1995  Yukihiro Matsumoto  (matz@ix-02)
-
-	* parse.y: ����Ϣ������κǸ��`,'�򤪤���褦�ˡ�
-
-Fri Feb 24 13:15:43 1995  Yukihiro Matsumoto  (matz@ix-02)
-
-	* version 0.68
-
-Thu Feb 23 11:19:19 1995  Yukihiro Matsumoto  (matz@ix-02)
-
-	* eval.c: resque���self���ͤ��ְ�äƤ�����
-
-	* eval.c(rb_clear_cache): ����å���Υ��ꥢ��˺�줬���ä���
-
-	* eval.c: ����Υ������פ򥯥饹�����Ū�������פ��ѹ������������
-	  ��äơ��ðۥ᥽�åɤ��黲�Ȥ��������ϡ��쥷���ФΥ��饹�ǤϤ�
-	  ����������줿�������פΥ��饹������Ȥʤ롥
-
-Wed Feb 22 00:51:38 1995  Yukihiro Matsumoto  (matz@dyna)
-
-	* regex.c: ignorecase������ɽ���Υ���ѥ������˻��ꤷ�ʤ���������
-	  ư��ʤ���������
-
-	* string.c(toupper,tolower): bug fix.
-
-	* ENV,VERSION: readonly�ѿ���������ء�
-
-Tue Feb 21 18:56:56 1995  Yukihiro Matsumoto  (matz@ix-02)
-
-	* io.c(STDIN, STDOUT, STDERR): ����Ȥ��������
-
-	* io.c(select): bug fix.
-
-	* version 0.67
-
-Mon Feb 20 16:10:14 1995  Yukihiro Matsumoto  (matz@ix-02)
-
-	* parse.y(yylex): �����`%���̻�'���顤��1ʸ������ʸ���μ��̻Ҥ���
-	  ��������ˤȤ�ʤ����饹������Ȥʤä���
-
-	* eval.c: ���饹������self�����饹���������the_class���ä���
-
-	* variable.c(rb_name_class): ���饹̾�򥤥󥹥����ѿ��˳�Ǽ���롥
-
-Thu Feb 16 15:36:17 1995  Yukihiro Matsumoto  (matz@ix-02)
-
-	* parse.y: BLOCK��brace��ɽ������ʸˡ���ѹ�������Τ��äƤߤ롥
-	  ML���󼨤��Ƥߤ뤬ȿ�����ʤ���
-
-	* object.c(do,forever): �ʤ�������
-
-Wed Feb 15 13:20:49 1995  Yukihiro Matsumoto  (matz@ix-02)
-
-	* re.c(new): ��2������Ϳ�����ơ�����nil�Ǥʤ��Ȥ��������ꤹ���
-	  ����(������nil�λ��ˤ������ԤʤäƤ���)��
-
-	* parse.y(parse_regexp): ����ɽ����ƥ�����ʸ����ʸ����̵�뤹��
-	  ���ɤ�������Ǥ���褦�ˡ�
-
-Tue Feb 14 00:55:33 1995  Yukihiro Matsumoto  (matz@dyna)
-
-	* parse.y: (compexpr) -> (expr).
-
-Fri Feb 10 16:30:00 1995  Yukihiro Matsumoto  (matz@ix-02)
-
-	* ruby.c(load_file): script���ɤ߹��������"#!"�β��Ϥ�Ԥ��褦�ˡ�
-
-	* ruby.c(readin): �ե������ɤ߹��߻�����Ƭ��"#!"�����ꡤ���ιԤ�
-	  "ruby"�Ȥ���ʸ�����ޤ����ruby�˰�����Ϳ�����Ƥ���С����ΰ�
-	  ����ͭ���ˤʤ롥
-
-	* parse.y(yylex): �����ȹԤν��꤬`\'�Ǥ��ä��������ιԤ˷�³��
-	  �Ƥ���Ȥߤʤ��褦�ˤ�����
-
-Thu Feb  9 16:18:37 1995  Yukihiro Matsumoto  (matz@ix-02)
-
-	* version 0.66
-
-	* parse.y: protect��begin���ѹ���begin..end���㳰���������Ǥʤ���
-	  ʸ��̤Ȥ��Ƥ�Ư�����Ȥˤʤä���
-
-Wed Feb  1 19:48:24 1995  Yukihiro Matsumoto  (matz@ix-02)
-
-	* version 0.65
-
-	* string.c(str_replace): �֤�������ʸ�����Ĺ���������������ꥳ
-	  �ԡ��򤷤ʤ���
-
-	* string.c(rindex): ��������
-
-Mon Jan 30 11:23:05 1995  Yukihiro Matsumoto  (matz@ix-02)
-
-	* parse.y(value_expr): if�Υ����å����ɲá�
-
-	* gc.c(gc_mark): free cell�ΰ����˥Х���
-
-	* parse.y: ʸˡ���ѹ�(��ꥷ��ץ��)���㳰�򸺤餷����
-
-Thu Jan 26 00:52:55 1995  Yukihiro Matsumoto  (matz@dyna)
-
-	* parse.y: �����Ȥ���Ϣ��������֤����Ȥ��Ǥ���褦�ˡ����ξ�硤
-	  Ϣ�������ƥ�뤬�ǽ������Ȥʤ롥
-
-	* parse.y: ���󻲾Ȥ�`[]'�⤬���Ǥ�褤���Ȥˤ�����
-
-Tue Jan 24 14:45:15 1995  Yukihiro Matsumoto  (matz@ix-02)
-
-	* class.c(rb_include_module): `-v'����ꤷ�����ˤ�include�����⥸�塼
-	  ��ȥ��饹��������ͤ��Ƥ��ʤ��������å����롥
-
-Mon Jan 23 10:42:09 1995  Yukihiro Matsumoto  (matz@ix-02)
-
-	* parse.y(rb_class2name): �᥿���饹�˴ؤ���bug fix.
-
-	* dict.c: Dict[..]�Ǽ���������������褦�ˡ�
-
-	* array.c: Array[..]������������������褦�ˡ�
-
-	* parse.y: �����ɽ���Ȥ���{a,b,..}�Ȥ�������������褦�ˡ�
-
-Fri Jan 20 10:28:38 1995  Yukihiro Matsumoto  (matz@ix-02)
-
-	* re.c(Regexp.quote): ����ɽ���򥨥������פ���᥽�åɡ�
-
-	* ̵�̤�rb_intern()�򸺤餷����
-
-	* parse.y: `!', `!=', `!~'���ü�黻�Ҥˤ��롥��äƤ����Ϻ����
-	  �Ǥ��ʤ��ʤä���
-
-Wed Jan 18 13:20:41 1995  Yukihiro Matsumoto  (matz@ix-02)
-
-	* parse.y: ʸˡ������(unless,until��ʤ�����)��
-
-Tue Jan 17 11:11:27 1995  Yukihiro Matsumoto  (matz@ix-02)
-
-	* eval.c: def�ǥ᥽�åɺ�������ˤϥ����ѡ����饹�Υ᥽�åɤβĻ�
-	  ����Ѿ����롥�ǽ������λ��Ϻ��ޤǤ�Ʊ���ǥե����(�ȥåץ��
-	  ��Ǵؿ�Ū�����饹�������̾�᥽�å�)��
-
-	* object.c(Class#new): ���֥������Ȥ��������˴ؿ�Ū�᥽�å�
-	  init_object��ɬ���ƤФ��褦���ѹ���
-
-	* eval.c: ̤����Υ᥽�åɤ��Ф���unknown�᥽�åɤ��ƤФ��褦��
-	  �ʤä������顼ɽ�������ޤǤ�Ʊ���ˤʤ�褦��env��Ĵ�ᤷ�Ƥ��롥
-
-Fri Jan 13 14:40:30 1995  Yukihiro Matsumoto  (matz@ix-02)
-
-	* gc.c: gc��㴳�񤭴����������������������ޤ��Ѳ��Ϥʤ��ä��褦����
-
-	* parse.y(yylex): symbol��\sym����:sym���ѹ�������
-
-Thu Jan 12 01:39:28 1995  Yukihiro Matsumoto  (matz@dyna)
-
-	* eval.c: �����ؿ� rb_eval_string()��
-
-	* gc.c: gc_mark()�������Ƶ�����
-
-	* variable.c(rb_ivar_{get,set}): ���󥹥����ѿ��Υ������������
-	  �����å���­��ʤ��ä���
-
-	* variable.c: ���饹����ȥ��󥹥����ѿ��ǥϥå���ơ��֥��ͭ
-	  ����褦�ˤ�����
-
-	* ruby.h: iv_tbl��RBasic����RObject��RClass�ذ�ư����������ˤ�ꡤ
-	  Object��Class,Module�������󥹥����ѿ�����Ƥʤ��ʤ롥�������
-	  ���Ψ�ϼ㴳���夹�롥
-
-Tue Jan 10 00:58:20 1995  Yukihiro Matsumoto  (matz@dyna)
-
-	* 0.64 released
-
-	* eval.c: �쥷���ФȰ����Ͼ��iter�ǤϤʤ���
-
-	* cons.c(aref,aset): negative offset���
-
-Mon Jan  9 14:40:39 1995  Yukihiro Matsumoto  (matz@ix-02)
-
-	* parse.y: foo{..}�η����ˤ����ơ�foo����������ѿ��䥯�饹̾�Ǥ�
-	  �ʤ��������ʤ��δؿ����᥽�åɸƤӽФ��Ȥߤʤ��褦�ˤ�����
-
-	* list.c -> cons.c: ̾���ѹ�(���饹̾��)��
-
-	* list.c: a::b::c::nil��ꥹ��(a b c)�Ȥߤʤ�lisp�������顤a::b::c
-	  ��ꥹ��(a b c)�Ȥߤʤ�ruby�������ѹ���[], []=, each�⤽��˲��
-	  �������ͤȤ��롥
-
-	* list.c: cons�ڥ��Ȥ��Ƥε�ǽ��Ĵ�������ѹ���
-
-Sat Jan  7 01:26:26 1995  Yukihiro Matsumoto  (matz@dyna)
-
-	* eval.c: �����������Զ�罤����
-
-	* eval.c(masign): ¿�������������ꥹ�Ȥ�Ȥ��褦�ˤ�����
-
-	* list.c: assoc��2���Ǥ����󤫤�List(CONS�ڥ�)���ѹ�������
-
-Fri Jan  6 13:42:12 1995  Yukihiro Matsumoto  (matz@ix-02)
-
-	* parse.y: a[b]+=c��a.b+=c�ʤɤμ������������ǡ�a��b��2��ɾ������
-	  ���ʤä���
-
-	* eval.c: iterator����ΥХ��ե��å�����
-
-	* list.c: List���饹���ߡ�
-
-Thu Jan  5 13:55:00 1995  Yukihiro Matsumoto  (matz@ix-02)
-
-	* parse.y: SCOPE�Υ���꡼����ʤ�������
-
-	* eval.c: built-in�᥽�åɤؤΰ����ΰ����Ϥ������ѹ����ơ��������
-	  �����򸺤餷����
-
-	* re.c: match-data������������뤳�Ȥ��᤿��`$~'�򥢥�����������
-	  ��on-demand���������롥
-
-	* string.c etc: ��ɬ�פ�memmove��memcpy���ִ���
-
-	* parse.y: =~, !~�������Ѥ�����Τǥ���ѥ������Ÿ���Ǥ��ʤ���
-
-Tue Jan  3 02:04:36 1995  Yukihiro Matsumoto  (matz@dyna)
-
-	* eval.c: rest������bug fix.
-
-	* eval.c,gc.c: scope�򥪥֥������Ȥˤ�����
-
-	* eval.c: env��scope�ΰ������ѹ�������
-
-Wed Dec 28 09:46:57 1994  Yukihiro Matsumoto  (matz@ix-02)
-
-	* parse.y: eval�ǥ��������ѿ����ɲä��줿�����б�������
-
-	* parse.y: �黻�Ҥ�ޤ�alias��bug fix.
-
-Tue Dec 27 16:45:20 1994  Yukihiro Matsumoto  (matz@ix-02)
-
-	* parse.y: def A B��alias A B���ѹ���
-
-	* eval.c: alias�ط���bug������node�򥪥֥������Ȳ���������enbug��
-	  ���褦����
-
-	* signal.c: �����ƥॳ����κ������ߤ᤿��
-
-	* io.c(select): write/except�Υե饰����˥Х���
-
-	* Makefile.in: static link�ѥ��ץ�����Make�ѿ��Ȥ�����Ω��������
-
-Tue Dec 20 00:46:19 1994  Yukihiro Matsumoto  (matz@dyna)
-
-	* 0.63 released
-
-	* eval.c(rb_call): super�θƤӽФ�������롥argc, argv�������˺��
-	  �Ƥ�����
-
-	* parse.y(read_escape): Ÿ�����顼��
-
-	* variable.c: ����Ѥߤ��ѿ���hook���ѹ����ʤ��褦�ˡ�
-
-Mon Dec 19 12:01:10 1994  Yukihiro Matsumoto  (matz@ix-02)
-
-	* parse.y(cond): ��Ｐ�����������֤��줿��硤`-v'���ץ����Ƿ�
-	  �𤬽Ф�褦�ˡ�
-
-	* parse.y(**): �Ѿ�黻��`**'��ͥ���̤�ñ��黻�Ҥ��⤯������
-
-	* parse.y(and,or): ͥ���̤��㤤�黻��`and', `or'.
-
-	* 0.62 released.
-
-	* eval.c: ��ɬ�פˤʤä�PUSH_ENV, POP_ENV�򸺤餷����
-
-	* env.h: ENVION����self��Ϥ�������PUSH_ENV��super�ν����Τ������
-	  ���Ѥ��뤳�Ȥˤ�����
-
-	* eval.c: �����Υ��֥������Ȳ����٤��ʤä��¹�®�٤��Ȥ��ᤷ����
-
-Mon Dec 17 23:01:10 1994  Yukihiro Matsumoto  (matz@ix-02)
-
-	* eval.c: env.{argv,argc}��scope.local_vars�Υ��֥������Ȳ���
-
-	* eval.c: 1�����������ʣ��Block�����������Ȥ��ΥХ�������
-
-Fri Dec 16 15:52:06 1994  Yukihiro Matsumoto  (matz@ix-02)
-
-	* parse.y: `&&'��`||'��ξ�դϤ��ĤǤ��Ｐ�Ȥ�����
-
-Thu Dec 15 00:16:04 1994  Yukihiro Matsumoto  (matz@dyna)
-
-	* eval.c(Block): Block���֥������Ȥ�¸���
-
-	* node.h: NODE_QLIST�Ϥʤ��ʤä���
-
-	* eval.c(rb_call): �����ؤ�������̾���ǰ�Ĥ�����������Τ���ơ�
-	  ���٤˥��ԡ�����褦�ˤ�����
-
-	* eval.c(rb_call): ruby�ǵ��Ҥ��줿�᥽�åɤؤΰ����Ϥ���inline����
-
-	* eval.c: ���ƥ졼��Ƚ����������̽񤭴�������Ŭ�ڤʥ��ƥ졼���Ƥ�
-	  �Ф���ʤ��������㤨�С�[foo(),bar()]{i|baz(i)}�פ�foo��bar�⥤
-	  �ƥ졼���Ȥ��ƸƤӽФ���*�ʤ�*��
-
-	* eval.c(rb_call): SCOPE������inline�����᥽�åɸƤӽФ��μ㴳�ι�
-	  ®����
-
-Wed Dec 14 18:09:33 1994  Yukihiro Matsumoto  (matz@ix-02)
-
-	* node.h: node�⥪�֥������Ȥˤ��롥��ä�GC�Dz������롥
-
-Thu Dec  8 14:17:29 1994  Yukihiro Matsumoto  (matz@ix-02)
-
-	* 0.60 released - alpha test baseline.
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 a1129f908a..0000000000
--- a/MANIFEST
+++ /dev/null
@@ -1,186 +0,0 @@
-ChangeLog
-MANIFEST
-Makefile.in
-README
-README.jp
-README.EXT
-ToDo
-array.c
-bignum.c
-class.c
-compar.c
-configure
-configure.bat
-configure.in
-config.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
-io.c
-io.h
-main.c
-math.c
-node.h
-numeric.c
-object.c
-pack.c
-parse.y
-process.c
-random.c
-range.c
-re.c
-re.h
-regex.c
-regex.h
-ruby.1
-ruby.c
-ruby.h
-sig.h
-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
-ext/Setup
-ext/Setup.dj
-ext/Setup.nt
-ext/Setup.x68
-ext/extmk.rb.in
-ext/extmk.rb.nt
-ext/aix_ld.rb
-lib/English.rb
-lib/base64.rb
-lib/cgi-lib.rb
-lib/complex.rb
-lib/date.rb
-lib/debug.rb
-lib/e2mmap.rb
-lib/e2mmap1_0.rb
-lib/find.rb
-lib/finalize.rb
-lib/ftplib.rb
-lib/getopts.rb
-lib/jcode.rb
-lib/mailread.rb
-lib/mathn.rb
-lib/matrix.rb
-lib/mutex_m.rb
-lib/observer.rb
-lib/parsearg.rb
-lib/parsedate.rb
-lib/ping.rb
-lib/rational.rb
-lib/sync.rb
-lib/thread.rb
-lib/thwait.rb
-lib/tk.rb
-lib/tkcore.rb
-lib/tkcanvas.rb
-lib/tkclass.rb
-lib/tkentry.rb
-lib/tkscrollbox.rb
-lib/tktext.rb
-lib/tkthcore.rb
-lib/tracer.rb
-missing/alloca.c
-missing/crypt.c
-missing/dir.h
-missing/dup2.c
-missing/file.h
-missing/flock.c
-missing/memmove.c
-missing/mkdir.c
-missing/nt.c
-missing/nt.h
-missing/setenv.c
-missing/strcasecmp.c
-missing/strdup.c
-missing/strerror.c
-missing/strftime.c
-missing/strstr.c
-missing/strtol.c
-missing/strtoul.c
-sample/biorhythm.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.rb
-sample/fib.scm
-sample/freq.rb
-sample/from.rb
-sample/fullpath.rb
-sample/getopts.test
-sample/io.rb
-sample/less.rb
-sample/list.rb
-sample/list2.rb
-sample/list3.rb
-sample/mrshtest.rb
-sample/mkproto.rb
-sample/mpart.rb
-sample/observ.rb
-sample/occur.pl
-sample/occur.rb
-sample/occur2.rb
-sample/philos.rb
-sample/pi.rb
-sample/rcs.awk
-sample/rcs.dat
-sample/rcs.rb
-sample/regx.rb
-sample/ruby-mode.el
-sample/rubydb2x.el
-sample/rubydb3x.el
-sample/sieve.rb
-sample/svr.rb
-sample/test.rb
-sample/time.rb
-sample/tkbiff.rb
-sample/tkbrowse.rb
-sample/tkdialog.rb
-sample/tkfrom.rb
-sample/tkhello.rb
-sample/tkline.rb
-sample/tktimer.rb
-sample/trojan.rb
-sample/tsvr.rb
-sample/uumerge.rb
-win32/Makefile
-win32/config.h
-win32/ntsetup.bat
-win32/ruby.def
-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 ee0ac1fcfc..0000000000
--- a/Makefile.in
+++ /dev/null
@@ -1,219 +0,0 @@
-SHELL = /bin/sh
-
-#### Start of system configuration section. ####
-
-srcdir = @srcdir@
-VPATH = @srcdir@:@srcdir@/missing
-
-CC = @CC@
-YACC = @YACC@
-INSTALL = @INSTALL@
-INSTALL_PROGRAM = @INSTALL_PROGRAM@
-INSTALL_DATA = @INSTALL_DATA@
-PURIFY =
-@SET_MAKE@
-
-CFLAGS = @CFLAGS@ -I@srcdir@
-LDFLAGS = @STATIC@ $(CFLAGS) @LDFLAGS@
-LIBS = @LIBS@ $(EXTLIBS)
-MISSING = @LIBOBJS@ @ALLOCA@
-
-program_transform_name = -e @program_transform_name@
-RUBY_INSTALL_NAME = `t='$(program_transform_name)'; echo ruby | sed $$t`
-
-prefix = @prefix@
-exec_prefix = @exec_prefix@
-bindir = @bindir@
-libdir = @libdir@/$(RUBY_INSTALL_NAME)
-
-binsuffix = @binsuffix@
-
-#### End of system configuration section. ####
-
-
-LIBRUBY	      = libruby.a
-
-EXTOBJS	      = dmyext.o
-
-MAINOBJ	      = main.o
-
-OBJS	      = array.o \
-		bignum.o \
-		class.o \
-		compar.o \
-		dir.o \
-		dln.o \
-		enum.o \
-		error.o \
-		eval.o \
-		file.o \
-		fnmatch.o \
-		gc.o \
-		glob.o \
-		hash.o \
-		inits.o \
-		io.o \
-		math.o \
-		numeric.o \
-		object.o \
-		pack.o \
-		parse.o \
-		process.o \
-		random.o \
-		range.o \
-		re.o \
-		regex.o \
-		ruby.o \
-		signal.o \
-		sprintf.o \
-		st.o \
-		string.o \
-		struct.o \
-		time.o \
-		util.o \
-		variable.o \
-		version.o \
-		$(MISSING)
-
-all:		miniruby$(binsuffix) @srcdir@/ext/Setup 
-		@if test -z "$$UNDER_EXTMAKE_RB"; \
-		then echo "Compiling ext modules"; \
-		UNDER_EXTMAKE_RB=yes; export UNDER_EXTMAKE_RB; \
-		cd ext; ../miniruby ./extmk.rb @EXTSTATIC@; fi
-
-miniruby$(binsuffix):	$(OBJS) $(MAINOBJ) $(EXTOBJS) 
-		@rm -f $@
-		$(PURIFY) $(CC) $(LDFLAGS) $(MAINOBJ) $(OBJS) $(EXTOBJS) $(LIBS) -o miniruby
-
-ruby$(binsuffix):     	$(LIBRUBY) $(MAINOBJ) $(EXTOBJS) 
-		@rm -f $@
-		$(PURIFY) $(CC) $(LDFLAGS) $(MAINOBJ) $(EXTOBJS) $(LIBRUBY) $(LIBS) -o ruby
-
-$(LIBRUBY):	$(OBJS) dmyext.o
-		@AR@ rcu $(LIBRUBY) $(OBJS) dmyext.o
-		@-@RANLIB@ $(LIBRUBY) 2> /dev/null || true
-
-install:;	$(INSTALL_PROGRAM) ruby$(binsuffix) $(bindir)/$(RUBY_INSTALL_NAME)$(binsuffix)
-		@-@STRIP@ $(bindir)/$(RUBY_INSTALL_NAME)$(binsuffix)
-		@test -d $(libdir) || mkdir $(libdir)
-		cd ext; ../miniruby ./extmk.rb install
-		@for rb in `grep '^lib/' @srcdir@/MANIFEST`; do \
-		  $(INSTALL_DATA) @srcdir@/$$rb $(libdir); \
-		done
-
-clean:;		@rm -f $(OBJS) $(LIBRUBY) $(MAINOBJ)
-		@rm -f ext/extinit.c ext/extinit.o dmyext.o
-		cd ext; ../miniruby ./extmk.rb clean
-
-realclean:	clean
-		@rm -f Makefile ext/extmk.rb ext/config.cache parse.c
-		@rm -f config.cache config.h config.log config.status
-		@rm -f core ruby$(binsuffix) miniruby$(binsuffix) parse.c *~ *.core gmon.out
-
-test:;		@-./ruby @srcdir@/sample/test.rb > ./ruby_test 2>&1; \
-		 if grep '^end of test' ./ruby_test > /dev/null; then \
-		   echo "test succeeded"; \
-		 else \
-	           grep '^sample/test.rb' ./ruby_test; \
-		   grep '^not' ./ruby_test; \
-	   	   echo "test failed";\
-		 fi;\
-		 rm -f ./ruby_test
-
-.c.o:
-	$(CC) $(CFLAGS) $(CPPFLAGS) -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
-
-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
-
-setenv.o: @srcdir@/missing/setenv.c
-	$(CC) $(CFLAGS) $(CPPFLAGS) -c @srcdir@/missing/setenv.c
-
-strcasecmp.o: @srcdir@/missing/strcasecmp.c
-	$(CC) $(CFLAGS) $(CPPFLAGS) -c @srcdir@/missing/strcasecmp.c
-
-strerror.o: @srcdir@/missing/strerror.c
-	$(CC) $(CFLAGS) $(CPPFLAGS) -c @srcdir@/missing/strerror.c
-
-strdup.o: @srcdir@/missing/strdup.c
-	$(CC) $(CFLAGS) $(CPPFLAGS) -c @srcdir@/missing/strdup.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 defines.h config.h env.h node.h st.h regex.h 
-###
-array.o: array.c ruby.h config.h defines.h
-bignum.o: bignum.c ruby.h config.h defines.h
-class.o: class.c ruby.h config.h defines.h node.h st.h
-compar.o: compar.c ruby.h config.h defines.h
-dir.o: dir.c ruby.h config.h defines.h
-dln.o: dln.c config.h defines.h dln.h st.h
-dmyext.o: dmyext.c
-enum.o: enum.c ruby.h config.h defines.h
-error.o: error.c ruby.h config.h defines.h env.h
-eval.o: eval.c ruby.h config.h defines.h env.h node.h sig.h st.h dln.h
-file.o: file.c ruby.h config.h defines.h io.h sig.h
-fnmatch.o: fnmatch.c config.h fnmatch.h
-gc.o: gc.c ruby.h config.h defines.h env.h sig.h st.h node.h re.h regex.h
-glob.o: glob.c config.h fnmatch.h
-hash.o: hash.c ruby.h config.h defines.h st.h
-inits.o: inits.c ruby.h config.h defines.h
-io.o: io.c ruby.h config.h defines.h io.h sig.h
-main.o: main.c
-math.o: math.c ruby.h config.h defines.h
-numeric.o: numeric.c ruby.h config.h defines.h
-object.o: object.c ruby.h config.h defines.h st.h
-pack.o: pack.c ruby.h config.h defines.h
-process.o: process.c ruby.h config.h defines.h sig.h st.h
-random.o: random.c ruby.h config.h defines.h
-range.o: range.c ruby.h config.h defines.h
-re.o: re.c ruby.h config.h defines.h re.h regex.h
-regex.o: regex.c config.h defines.h regex.h util.h
-ruby.o: ruby.c ruby.h config.h defines.h re.h regex.h dln.h
-signal.o: signal.c ruby.h config.h defines.h sig.h
-sprintf.o: sprintf.c ruby.h config.h defines.h
-st.o: st.c config.h st.h
-string.o: string.c ruby.h config.h defines.h re.h regex.h
-struct.o: struct.c ruby.h config.h defines.h
-time.o: time.c ruby.h config.h defines.h
-util.o: util.c defines.h config.h util.h
-variable.o: variable.c ruby.h config.h defines.h env.h st.h
-version.o: version.c ruby.h config.h defines.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 6583bc889f..0000000000
--- a/README
+++ /dev/null
@@ -1,108 +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)
-
-* How to get ruby
-
-** by ftp
-
-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, if 
-     you want to link modules statically.
-
-     If you want to link all the extension modules, remove comment
-     mark from the line "#option nodynamic".
-
-  4. Run make.
-
-  5. Optionally, run 'make test' to check that the compiled ruby
-     interpreter works well.  If you see the message "test succeeded", 
-     your ruby works as it should.
-
-  6. Run 'make install'
-
-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 by Yukihiro Matsumoto <matz@ruby.club.co.jp>.
-
-This source is distributed under the conditions blow:
-
- 1. You may make and give away verbatim copies of the source form of
-    the software without restriction, provided that you do not modify
-    the original distribution files.
-
-    If you want to distribute the modified version in any way, contact 
-    the author.
-
-  2. You may distribute the software in object code or executable
-     form, provided that you distribute it with instructions on where
-     to get the software.
-
-  3. You may modify the software in any way, provided that you do not
-     distribute the modified version.
-
-  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 somme files under the ./missing directory.  See
-     each files 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 c2f81d1a7a..48b8d964c4 100644
--- a/README.EXT
+++ b/README.EXT
@@ -1,1064 +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.
-
-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���
-
-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
-
-�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������)��
-
-����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���RARRAT(str)->len�ס�
-��RARRAT(str)->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 Convert C data into VALUE
-
-VALUE�μºݤι�¤��
-
-  * FIXNUM��
-
-    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���������
-
-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����˼��ޤ��
-  INT2NUM()	Ǥ�դ���������VALUE��
-
-INT2NUM()��������FIXNUM���ϰϤ˼��ޤ�ʤ���硤Bignum���Ѵ�
-���Ƥ���ޤ�(���������٤�)��
-
-1.5 Manipulate ruby data
-
-������Ҥ٤��̤ꡤruby�ι�¤�Τ򥢥���������������Ƥι�����
-�Ԥ����Ȥϴ�����ޤ��󡥤ǡ�ruby�Υǡ�����������ˤ�
-ruby���Ѱդ��Ƥ���ؿ����Ѥ��Ƥ���������
-
-�����ǤϤ�äȤ�Ȥ���Ǥ�����ʸ��������������/�����
-���ؿ��򤢤��ޤ�(�����ǤϤʤ��Ǥ�)��
-
- String funtions
-
-  str_new(char *ptr, int len)
-
-    Creates a new ruby string.
-
-  str_new2(char *ptr)
-
-    Creates a new ruby string from C string.  This is equivalent to
-    str_new(ptr, strlen(ptr)).
-
-  str_cat(VALUE str, char *ptr, int len)
-
-    Appends len bytes data from ptr to the ruby string.
-
- Array functions
-
-  ary_new()
-
-    Creates an array with no element.
-
-  ary_new2(int len)
-
-    Creates an array with no element, with allocating internal buffer
-    for len elements.
-
-  ary_new3(int n, ...)
-
-    Creates an n-elements array from arguments.
-
-  ary_new4(int n, VALUE *elts)
-
-    Creates an n-elements array from C array.
-
-  ary_push(VALUE ary)
-  ary_pop(VALUE ary, VALUE val)
-  ary_shift(VALUE ary)
-  ary_unshift(VALUE ary, VALUE val)
-  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
-
-ruby���󶡤���Ƥ���ؿ���Ȥ���ruby���󥿥ץ꥿�˿�������ǽ
-���ɲä��뤳�Ȥ��Ǥ��ޤ���ruby�Ǥϰʲ��ε�ǽ���ɲä���ؿ���
-�󶡤���Ƥ��ޤ���
-
- * ���饹���⥸�塼��
- * �᥽�åɡ��ðۥ᥽�åɤʤ�
- * ���
-
-�ǤϽ�˾Ҳ𤷤ޤ���
-
-2.1.1 Class/module definition
-
-���饹��⥸�塼���������뤿��ˤϡ��ʲ��δؿ���Ȥ��ޤ���
-
-  VALUE rb_define_class(char *name, VALUE super)
-  VALUE rb_define_module(char *name)
-
-�����δؿ��Ͽ�����������줿���饹��⥸�塼����֤��ޤ���
-�᥽�åɤ����������ˤ������ͤ�ɬ�פʤΤǡ��ۤȤ�ɤξ��
-������ͤ��ѿ��˳�Ǽ���Ƥ���ɬ�פ�����Ǥ��礦��
-
-2.1.2 Method/singleton method definition
-
-�᥽�åɤ��ðۥ᥽�åɤ��������ˤϰʲ��δؿ���Ȥ��ޤ���
-
-  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)
-
-
-ǰ�Τ�����������ȡ��ðۥ᥽�åɡפȤϡ���������Υ��֥�����
-�Ȥ��Ф��Ƥ���ͭ���ʥ᥽�åɤǤ���ruby�ǤϤ褯Smalltalk�ˤ�
-���륯�饹�᥽�åɤȤ��ơ����饹���Ф����ðۥ᥽�åɤ��Ȥ��
-�ޤ���
-
-�����δؿ��� argc�Ȥ���������C�δؿ����Ϥ��������ο�(��
-����)����ޤ���argc�����λ��ϴؿ��˰����Ϥ������ο����̣
-���ޤ���16�İʾ�ΰ����ϻȤ��ޤ���(�����פ�ޤ����͡�����
-�ʤ�)��
-
-argc����λ��ϰ����ο��ǤϤʤ�����������ꤷ�����Ȥˤʤ�ޤ���
-argc��-1�λ��ϰ����������������Ϥ���ޤ���argc��-2�λ��ϰ�
-����ruby������Ȥ����Ϥ���ޤ���
-
-�᥽�åɤ��������ؿ��Ϥ⤦��Ĥ���ޤ����ҤȤĤ�private��
-���åɤ��������ؿ��ǡ�������rb_define_method()��Ʊ���Ǥ���
-
-  void rb_define_private_method(VALUE class, char *name, 
-			        VALUE (*func)(), int argc)
-
-private�᥽�åɤȤϴؿ������Ǥ����ƤӽФ����Ȥν���ʤ��᥽��
-�ɤǤ���
-
-�⤦�ҤȤĤϥ⥸�塼��ؿ�����������ΤǤ����⥸�塼��ؿ�
-�Ȥϥ⥸�塼����ðۥ᥽�åɤǤ��ꡤƱ����private�᥽�åɤ�
-�⤢���ΤǤ�����򤢤����Math�⥸�塼���sqrt()�ʤɤ�����
-���ޤ������Υ᥽�åɤ�
-
-  Math.sqrt(4)
-
-�Ȥ��������Ǥ�
-
-  include Math
-  sqrt(4)
-
-�Ȥ��������Ǥ�Ȥ��ޤ����⥸�塼��ؿ����������ؿ��ϰʲ���
-�̤�Ǥ���
-
-  void rb_define_module_function(VALUE module, char *name, 
-				 VALUE (*func)(), int argc)
-
-�ؿ�Ū�᥽�å�(Kernel�⥸�塼���privaet method)��������뤿
-��δؿ��ϰʲ����̤�Ǥ���
-
-  void rb_define_global_function(char *name, VALUE (*func)(), int argc)
-
-
-2.1.3 Constant definition
-
-��ĥ�⥸�塼�뤬ɬ�פ�����Ϥ��餫����������Ƥ����������ɤ�
-�Ǥ��礦��������������ؿ�����Ĥ���ޤ���
-
-  void rb_define_const(VALUE class, char *name, VALUE val)
-  void rb_define_global_const(char *name, VALUE val)
-
-���Ԥ�����Υ��饹/�⥸�塼���°�����������������Ρ���
-�Ԥϥ������Х���������������ΤǤ���
-
-2.2 Use ruby features from C
-
-���ˡ�1.5 ruby�Υǡ���������٤ǰ����Ҳ𤷤��褦�ʴؿ���
-�Ȥ��С�ruby�ε�ǽ��¸����Ƥ���ؿ���ľ�ܸƤӽФ����Ȥ�����
-�ޤ���
-
-# ���Τ褦�ʴؿ��ΰ���ɽ�Ϥ��ޤΤȤ�������ޤ��󡥥�������
-# �뤷���ʤ��Ǥ��͡�
-
-����ʳ��ˤ�ruby�ε�ǽ��ƤӽФ���ˡ�Ϥ����Ĥ�����ޤ���
-
-2.2.1 ruby�Υץ�������eval����
-
-C����ruby�ε�ǽ��ƤӽФ���äȤ��ñ����ˡ�Ȥ��ơ�ʸ�����
-Ϳ����줿ruby�Υץ�������ɾ������ؿ�������ޤ���
-
-  VALUE rb_eval_string(char *str)
-
-����ɾ���ϸ��ߤδĶ��ǹԤ��ޤ����Ĥޤꡤ���ߤΥ��������ѿ�
-�ʤɤ�����Ѥ��ޤ���
-
-2.2.2 ID or Symbol
-
-C����ʸ������ͳ������ruby�Υ᥽�åɤ�ƤӽФ����Ȥ�Ǥ���
-�����������ˡ�ruby���󥿥ץ꥿��ǥ᥽�åɤ��ѿ�̾����ꤹ��
-���˻Ȥ��Ƥ���ID�ˤĤ����������Ƥ����ޤ��礦��
-
-ID�Ȥ��ѿ�̾���᥽�å�̾��ɽ�������Ǥ���ruby����Ǥ�
-
- :���̻�
-
-�ǥ��������Ǥ��ޤ���C���餳�����������뤿��ˤϴؿ�
-
-  rb_intern(char *name)
-
-��Ȥ��ޤ����ޤ���ʸ���α黻�ҤϤ���ʸ�������ɤ����Τޤޥ���
-�ܥ�ˤʤäƤ��ޤ���
-
-2.2.3 Invoke ruby method from C
-
-C����ʸ������ͳ������ruby�Υ᥽�åɤ�ƤӽФ�����ˤϰʲ�
-�δؿ���Ȥ��ޤ���
-
-  VALUE rb_funcall(VALUE recv, ID mid, int argc, ...)
-
-���δؿ��ϥ��֥�������recv��mid�ǻ��ꤵ���᥽�åɤ�Ƥӽ�
-���ޤ���
-
-2.2.4 �ѿ�/����򻲾�/��������
-
-C����ؿ���Ȥäƻ��ȡ������Ǥ���Τϡ����饹��������󥹥�
-���ѿ��Ǥ�������ѿ��ϰ����Τ�Τ�C������ѿ��Ȥ��ƥ�����
-���Ǥ��ޤ������������ѿ��򻲾Ȥ�����ˡ�ϸ������Ƥ��ޤ���
-
-���֥������ȤΥ��󥹥����ѿ��򻲾ȡ���������ؿ��ϰʲ�����
-��Ǥ���
-
-  VALUE rb_ivar_get(VALUE obj, ID id)
-  VALUE rb_ivar_set(VALUE obj, ID id, VALUE val)
-
-id��rb_intern()���������Τ�ȤäƤ���������
-
-���饹����򻲾Ȥ���ˤϰʲ��δؿ���ȤäƤ���������
-
-  VALUE rb_const_get(VALUE obj, ID id)
-
-���饹����򿷤���������뤿��ˤϡ�2.1.3 �������٤ǾҲ�
-��Ƥ���ؿ���ȤäƤ���������
-
-3. Informatin sharing between ruby and C
-
-C�����ruby�δ֤Ǿ����ͭ������ˡ�ˤĤ��Ʋ��⤷�ޤ���
-
-3.1 Ruby constant that C���黲�ȤǤ���ruby�����
-
-Following ruby constants can be referred from C.
-
-  TRUE
-  FALSE
-
-Boolean values.  FALSE 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)
-
-���δؿ���ruby��C�ȤǶ�ͭ��������ѿ���������ޤ����ѿ�̾��
-`$'�ǻϤޤ�ʤ����ˤϼ�ưŪ���ɲä���ޤ��������ѿ����ͤ���
-������ȼ�ưŪ��ruby���б������ѿ����ͤ��Ѥ��ޤ���
-
-�ޤ�ruby¦����Ϲ����Ǥ��ʤ��ѿ��⤢��ޤ�������read only��
-�ѿ��ϰʲ��δؿ���������ޤ���
-
-  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���
-
-Data���֥������Ȥ��������ƹ�¤�Τ�ruby���֥������Ȥ˥��ץ���
-�����뤿��ˤϡ��ʲ��Υޥ�����Ȥ��ޤ���
-
-  Data_Wrap_Struct(class,mark,free,ptr)
-
-���Υޥ���������ͤ��������줿Data���֥������ȤǤ���
-
-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)
-
-���Υޥ���������ͤ��������줿Data���֥������ȤǤ���
-
-class, mark, free��Data_Wrap_Struct��Ʊ��Ư���򤷤ޤ���type
-�ϳ�����Ƥ�C��¤�Τη��Ǥ���������Ƥ�줿��¤�Τ��ѿ�sval
-����������ޤ��������ѿ��η��� (type*) �Ǥ���ɬ�פ�����ޤ���
-
-Data���֥������Ȥ���ݥ��󥿤���Ф��Τϰʲ��Υޥ������Ѥ�
-�ޤ���
-
-  Data_Get_Struct(obj, type, sval)
-
-C�ι�¤�ΤؤΥݥ��󥿤��ѿ�sval����������ޤ���
-
-������Data�λȤ����Ϥ���ä�ʬ����ˤ����Τǡ������������
-����򻲾Ȥ��Ƥ���������
-
-4��Example - Create dbm module
-
-�����ޤǤ������ǤȤꤢ������ĥ�⥸�塼��Ϻ���Ϥ��Ǥ���
-ruby��ext�ǥ��쥯�ȥ�ˤ��Ǥ˴ޤޤ�Ƥ���dbm�⥸�塼������
-�����ʳ�Ū���������ޤ���
-
-(1) make the directory
-
-  % mkdir ext/dbm
-
-ruby��Ÿ�������ǥ��쥯�ȥ�β���ext�ǥ��쥯�ȥ����˳�ĥ��
-���塼���ѤΥǥ��쥯�ȥ����ޤ���̾����Ŭ��������ǹ�����
-����
-
-(2) create MANIFEST file
-
-  % cd ext/dbm
-  % touch MANIFEST
-
-��ĥ�⥸�塼��Υǥ��쥯�ȥ�β��ˤ�MANIFEST�Ȥ����ե����뤬
-ɬ�פʤΤǡ��Ȥꤢ�������Υե�������äƤ����ޤ�����Ǥ���
-�ե�����ˤ�ɬ�פʥե�������������뤳�Ȥˤʤ�ޤ���
-
-MANIFEST�Ȥ����ե�����ϡ�make�λ��˥ǥ��쥯�ȥ꤬��ĥ�⥸�塼
-���ޤ�Ǥ��뤫�ɤ���Ƚ�ꤹ�뤿��˻Ȥ���Ƥ��ޤ���
-
-(3) design the library
-
-�ޤ��������ʤ�Ǥ����ɡ��ɤ�������ǽ��¸����뤫�ɤ����ޤ���
-�פ���ɬ�פ�����ޤ����ɤ�ʥ��饹��Ĥ��뤫�����Υ��饹�ˤ�
-�ɤ�ʥ᥽�åɤ����뤫�����饹���󶡤�������ʤɤˤĤ����߷�
-���ޤ���dbm���饹�ˤĤ��Ƥ�ext/dbm.doc�򻲾Ȥ��Ƥ���������
-
-(4) write C code.
-
-��ĥ�⥸�塼�����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�⥸�塼�������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()
-{
-    /* DBM���饹��������� */
-    cDBM = rb_define_class("DBM", cObject);
-    /* DBM��Enumerate�⥸�塼��򥤥󥯥롼�ɤ��� */
-    rb_include_module(cDBM, mEnumerable);
-
-    /* DBM���饹�Υ��饹�᥽�å�open(): ������C������Ǽ����� */
-    rb_define_singleton_method(cDBM, "open", fdbm_s_open, -1);
-
-    /* DBM���饹�Υ᥽�å�close(): �����Ϥʤ� */
-    rb_define_method(cDBM, "close", fdbm_close, 0);
-    /* DBM���饹�Υ᥽�å�[]: ������1�� */
-    rb_define_method(cDBM, "[]", fdbm_fetch, 1);
-		:
-
-    /* DBM�ǡ������Ǽ���륤�󥹥����ѿ�̾�Τ����ID */
-    id_dbm = rb_intern("dbm");
-}
---
-
-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;
-    struct RArray *args;
-{
-	:
-}
---
-
-��1������self����2������ruby������Ǥ��������Ǥϥ��㥹�Ȥ�
-�餹���� struct RArray* �Ǽ����Ƥ��ޤ�����VALUE�Ǥ�Ʊ������
-�Ǥ���
-
-** ���ջ���
-
-ruby�ȶ�ͭ�Ϥ��ʤ���ruby�Υ��֥������Ȥ��Ǽ�����ǽ���Τ���
-C������ѿ��ϰʲ��δؿ���Ȥä�ruby���󥿥ץ꥿���ѿ���¸��
-�򶵤��Ƥ����Ƥ����������Ǥʤ���GC�ǥȥ�֥�򵯤����ޤ���
-
-  void rb_global_variable(VALUE *var)
-
-(5) prepare extconf.rb
-
-�⤷�ǥ��쥯�ȥ�ˡ�extconf.rb�פȤ����ե����뤬¸�ߤ���С�
-make���˼¹Ԥ���ޤ����ʤ����Ŭ����Makefile����������ޤ���
-
-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)
-
-�⤷���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�����̾�������
-
-  % ls > 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) 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
-
-�ޤ����ǥХå����ʤ���ư���ʤ��Ǥ��礦�͡�ext/Setup�˥ǥ���
-���ȥ�̾��񤯤���Ū�˥�󥯤���ΤǥǥХå����Ȥ���褦�ˤ�
-��ޤ�������ʬ����ѥ��뤬�٤��ʤ�ޤ����ɡ�
-
-(10) done, now you have the extension module
-
-��Ϥ��ä���Ȥ��ʤꡤ������������ʤꡤ���ʤꡤ����ͳ�ˤ�
-�Ȥ�����������ruby�κ�Ԥϳ�ĥ�⥸�塼��˴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�⥸�塼���Ʊ��������ˤʤ�
-�Ƥ��ޤ��������Υ������Ϻ��ޤǤ������ǤۤȤ������Ǥ����
-�פ��ޤ���
-
-coore ruby language
-
-  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. ��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
-
-** Variables and constants
-
- Qnil
-
-const: nil object
-
- TRUE
-
-const: TRUE object(default true value)
-
- FALSE
-
-const: FALSE object
-
-** 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��
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-�������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�����
-
-** ���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)
-
-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)
-
-������ruby�⥸�塼����������module������Ȥ���������롥
-
- 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)
-
-���֥������Ȥ�⥸�塼��(���������Ƥ���᥽�å�)�dz�ĥ���롥
-
-** ����ѿ����
-
- void rb_define_variable(char *name, VALUE *var)
-
-ruby��C�ȤǶ�ͭ���륰�����Х��ѿ���������롥�ѿ�̾��`$'�ǻ�
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-�Ƶ�����ʤ�ʸ��(�㤨��` ')��ޤ���ˤ�ruby�ץ�����फ��
-�ϸ����ʤ��ʤ롥
-
- void rb_define_readonly_variable(char *name, VALUE *var)
-
-ruby��C�ȤǶ�ͭ����read only�Υ������Х��ѿ���������롥read
-only�Ǥ��뤳�Ȱʳ���rb_define_variable()��Ʊ����
-
- void rb_define_virtual_variable(char *name,
-				VALUE (*getter)(), VALUE (*setter)())
-
-�ؿ��ˤ�äƼ¸������ruby�ѿ���������롥�ѿ������Ȥ��줿��
-�ˤ�getter�����ѿ����ͤ����åȤ��줿���ˤ�setter���ƤФ�롥
-
- void rb_define_hooked_variable(char *name, VALUE *var,
-				VALUE (*getter)(), VALUE (*setter)())
-
-�ؿ��ˤ�ä�hook�ΤĤ���줿�������Х��ѿ���������롥�ѿ���
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-���Τ�Ʊ�����ˤʤ롥
-
- void rb_global_variable(VALUE *var)
-
-GC�Τ��ᡤruby�ץ�����फ��ϥ�����������ʤ���, ruby���֥���
-���Ȥ�ޤ�����ѿ���ޡ������롥
-
-** ���饹���
-
- void rb_define_const(VALUE class, char *name, VALUE val)
-
-���饹�����������롥
-
- void rb_define_global_const(char *name, VALUE val)
-
-��������������롥
-
-     rb_define_const(cKernal, name, val)
-
-��Ʊ����̣��
-
-** �᥽�å����
-
- rb_define_method(VALUE class, char *name, VALUE (*func)(), int argc)
-
-�᥽�åɤ�������롥argc��self����������ο���argc��-1�λ�, 
-�ؿ��ˤϰ����ο�(self��ޤޤʤ�)����1����, �������������2��
-���Ȥ��������Ϳ������(��3������self)��argc��-2�λ�, ��1��
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-����Ϳ�����롥
-
- rb_define_private_method(VALUE class, char *name, VALUE (*func)(), int argc)
-
-private�᥽�åɤ�������롥������rb_define_method()��Ʊ����
-
- rb_define_singleton_method(VALUE class, char *name, VALUE (*func)(), int argc)
-
-�ðۥ᥽�åɤ�������롥������rb_define_method()��Ʊ����
-
- 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, ...)
-
-�᥽�åɸƤӽФ���ʸ���󤫤�mid�����뤿��ˤ�rb_intern()��Ȥ���
-
- VALUE rb_funcall2(VALUE recv, ID mid, int argc, VALUE *argv)
-
-�᥽�åɸƤӽФ���������argc,argv�������Ϥ���
-
- VALUE rb_eval_string(char *str)
-
-ʸ�����ruby�ȥ�����ץȤ��ƥ���ѥ��롦�¹Ԥ��롥
-
- ID rb_intern(char *name)
-
-ʸ������б�����ID���֤���
-
- char *rb_id2name(ID id)
-
-ID���б�����ʸ������֤�(�ǥХå���)��
-
- char *rb_class2name(VALUE class)
-
-class��̾�����֤�(�ǥХå���)��class��̾��������ʤ����ˤ�, 
-������̤ä�̾������ĥ��饹��̾�����֤���
-
-** ���󥹥����ѿ�
-
- VALUE rb_iv_get(VALUE obj, char *name)
-
-obj�Υ��󥹥����ѿ����ͤ����롥`@'�ǻϤޤ�ʤ����󥹥���
-�ѿ��� ruby�ץ�����फ�饢�������Ǥ��ʤ��ֱ��줿�ץ��󥹥�
-���ѿ��ˤʤ롥
-
- VALUE rb_iv_set(VALUE obj, char *name, VALUE val)
-
-obj�Υ��󥹥����ѿ���val�˥��åȤ��롥
-
-** ���湽¤
-
- 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 Warning(char *fmt, ...)
-
-verbose����ɸ�२�顼���Ϥ˷ٹ�����ɽ�����롥������printf()��Ʊ����
-
- void Fail(char *fmt, ...)
-
-�㳰��ȯ�������롥������printf()��Ʊ����
-
- void Fatal(char *fmt, ...)
-
-��̿Ū�㳰��ȯ�������롥�̾���㳰�����ϹԤʤ�줺, ���󥿡�
-�ץ꥿����λ����(������ensure�ǻ��ꤵ�줿�����ɤϽ�λ���˼�
-�Ԥ����)��
-
- void Bug(char *fmt, ...)
-
-���󥿡��ץ꥿�ʤɥץ������ΥХ��Ǥ���ȯ������Ϥ��Τʤ���
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-
-** ruby�ν�������¹�
-
-ruby�򥢥ץꥱ����������������ˤϰʲ��Υ��󥿥ե�����
-��Ȥ����̾�γ�ĥ�⥸�塼��ˤ�ɬ�פʤ���
-
- void ruby_init(int argc, char **argv, char **envp)
-
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-
- void ruby_run()
-
-ruby���󥿥ץ꥿��¹Ԥ��롥
-
- void ruby_script(char *name)
-
-ruby�Υ�����ץ�̾($0)�����ꤹ�롥
-
-Appendix B. extconf.rb�ǻȤ���ؿ�����
-
-extconf.rb����Ǥ����Ѳ�ǽ�ʥ���ѥ���������å��δؿ��ϰ�
-�����̤�Ǥ��롥
-
- have_library(lib, func)
-
-�ؿ�func��������Ƥ���饤�֥��lib��¸�ߤ�����å����롥��
-���֥�꤬¸�ߤ������TRUE���֤���
-
- have_func(func)
-
-�ؿ�func��¸�ߤ�����å����롥func��ɸ��Ǥϥ�󥯤���ʤ���
-���֥����Τ�ΤǤ�����ˤ����have_library�Ǥ��Υ饤�֥��
-������å����Ƥ��������ؿ���¸�ߤ����TRUE���֤���
-
- have_header(header)
-
-�إå��ե������¸�ߤ�����å����롥�إå��ե����뤬¸�ߤ���
-��TRUE���֤���
-
- create_makefile(target)
-
-��ĥ�⥸�塼���Ѥ�Makefile���������롥���δؿ���ƤФʤ����
-���Υ⥸�塼��ϥ���ѥ��뤵��ʤ���target�ϥ⥸�塼��̾��ɽ
-����
-
-/*
- * Local variables:
- * fill-column: 60
- * 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.ja.md b/README.ja.md
new file mode 100644
index 0000000000..bee6433c62
--- /dev/null
+++ b/README.ja.md
@@ -0,0 +1,185 @@
+[![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取得できます．
+
+    $ svn co https://svn.ruby-lang.org/repos/ruby/branches/ruby_2_6/ ruby
+
+他に開発中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
+
+mailto: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
+
+mailto: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．
+
+## 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.  もし `configure` ファイルが見つからない，もしくは `configure.ac` より古いようなら， `autoconf` 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 8a100106b1..0000000000
--- a/README.jp
+++ /dev/null
@@ -1,150 +0,0 @@
-* Ruby�Ȥ�
-
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-Ruby�Ϻǽ餫����ʥ��֥������Ȼظ�����Ȥ����߷פ���Ƥ���
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-������������̾�μ�³�����Υץ�����ߥ󥰤��ǽ�Ǥ���
-
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-�ˤ�äơ����ʬ����䤹���ץ�����ߥ󥰤�����ޤ���
-
-* Ruby������
-
-  + ����ץ��ʸˡ
-  + ���̤Υ��֥������Ȼظ���ǽ(���饹���᥽�åɥ�����ʤ�)
-  + �ü�ʥ��֥������Ȼظ���ǽ(Mixin, �ðۥ᥽�åɤʤ�)
-  + �黻�ҥ����С�������
-  + �㳰������ǽ
-  + ���ƥ졼���ȥ���������
-  + �����١������쥯��
-  + �����ʥߥå������ǥ��� (�������ƥ�����ˤ��)
-  + �ܿ������⤤��¿����UNIX���ư��
-
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-
-** ftp��
-
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-
-  ftp://ftp.netlab.co.jp/pub/lang/ruby/
-
-* �ۡ���ڡ���
-
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-
-   http://www.netlab.co.jp/ruby/jp/
-
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-
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- �ɥ쥹��
-
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-
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-
-* ����ѥ��롦���󥹥ȡ���
-
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-
-  1. configure��¹Ԥ���Makefile�ʤɤ���������
-
-  2. (ɬ�פʤ��)defines.h���Խ�����
-
-     ¿ʬ��ɬ��̵���Ȼפ��ޤ���
-
-  3. (ɬ�פʤ��)ext/Setup����Ū�˥�󥯤����ĥ�⥸�塼���
-     ���ꤹ��
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-     ext/Setup�˵��Ҥ����⥸�塼�����Ū�˥�󥯤���ޤ���
-
-     �����ʥߥå������ǥ��󥰤򥵥ݡ��Ȥ��Ƥ��ʤ��������ƥ�
-     ����Ǥ�Setup��1���ܤΡ�option nodynamic�פȤ����ԤΥ�
-     ���Ȥ򳰤�ɬ�פ�����ޤ����ޤ������Υ������ƥ������
-     ��ĥ�⥸�塼������Ѥ��뤿��ˤϡ����餫������Ū�˥��
-     �����Ƥ���ɬ�פ�����ޤ���
-
-  4. make��¹Ԥ��ƥ���ѥ��뤹��
-
-  5. make test�ǥƥ��Ȥ�Ԥ���
-
-     ��test succeeded�פ�ɽ�������������Ǥ����������ƥ���
-     ���������Ƥⴰ�������ݾڤ���Ƥ������ǤϤ���ޤ���
-
-  6. make install
-
-�⤷������ѥ�����˥��顼��ȯ���������ˤϥ��顼�Υ����ȥ�
-����OS�μ����ޤ�Ǥ�������ܤ�����ݡ��Ȥ��Ԥ����äƤ�
-�������¾�����Τ���ˤ�ʤ�ޤ���
-
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-
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-�������פ�̸���Ȥ������ä����(����˰㤤�ʤ�)����Ԥˤ���
-���Ȥ��ݡ��Ȥ���С����Ǥ��뤫���Τ�ޤ���
-
-�������ƥ�����ˤ�äȤ��¸����Τ�GC���Ǥ���ruby��GC���о�
-�Υ������ƥ����㤬setjmp()�ˤ�ä����ƤΥ쥸������ jmp_buf��
-��Ǽ���뤳�Ȥȡ�jmp_buf�ȥ����å���32bit���饤����Ȥ����
-���뤳�Ȥ��ꤷ�Ƥ��ޤ����ä����Ԥ���Ω���ʤ������б�����
-��˺���Ǥ��礦����Ԥβ������Ū��ñ�ǡ�gc.c�ǥ����å���
-�ޡ������Ƥ�����ʬ�˥��饤����ȤΥХ��ȿ��������餷�ƥޡ�
-�����륳���ɤ��ɲä�������ǺѤߤޤ�����defined(THINK_C)�פ�
-����Ƥ�����ʬ�򻲹ͤˤ��Ƥ�������
-
-# �ºݤˤ�ruby��Think C�Ǥϥ���ѥ���Ǥ��ޤ���
-
-�쥸����������ɥ������CPU�Ǥϡ��쥸����������ɥ��򥹥���
-���˥ե�å��夹�륢����֥饳���ɤ��ɲä���ɬ�פ����뤫����
-��ޤ���
-
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-
-��Ԥϰʲ��ξ��Τ�Ȥ�ruby�����ۤ��ޤ���
-
-  + ������
-
-    ���ۤ������֤�ݻ�����¤꼫ͳ�Ǥ����ѹ���Ԥä���Τ��
-    ���ۤ��뤳�Ȥ��˾������ˤϺ�Ԥ�Ϣ�����Ƥ���������
-
-    �ѹ���Ԥʤ�ʤ�ruby�򥳥�ѥ��뤷���Х��ʥ�����ۤ϶ػ�
-    ���ޤ��󤬡��Х��ʥ�������ä��ͤ�������������Ǥ����
-    ���ˡ�������������ˡ���������Ƥ���������
-
-  + �ѹ�
-
-    �����ۤ�Ԥ�ʤ��¤ꡤ�����ʤ���Ū�Ǥ��켫ͳ�Ǥ�����������
-    ��ǽ��ĥ��Х������Ϻ�ԤؤΥե����ɥХå�����Ԥ��ޤ�
-    (����������ǤϤ���ޤ���)��
-
-  + ¾�Υץ������ؤΰ���
-
-    �����ʤ���Ū�Ǥ��켫ͳ�Ǥ�����������ruby�˴ޤޤ��¾�κ�
-    �Ԥˤ�륳���ɤϡ����줾��κ�Ԥΰո��ˤ�����¤��ä���
-    ��ޤ�������Ū�ˤ�gc.c(����)��util.c(����)��regex.[ch]��
-    fnmatch.[ch]��glob.c��st.[ch]��./missing�ǥ��쥯�ȥ겼��
-    �ե����뷲���������ޤ���
-
-  + Ruby������ץȤθ���
-
-    ���Ƥ�ruby������ץȤθ����Ϥ��줾�������Ԥ�°���ޤ���
-    ��ԤϤ����˴ؤ��ư��ڤθ������ĥ���ޤ��󡥤ޤ�ruby��
-    �Ȥ߹��ि��γ�ĥ�⥸�塼��˴ؤ��Ƥ�Ʊ�ͤǤ���
-
-  + ̵�ݾ�
-
-    Ruby��̵�ݾڤǤ�����Ԥ�ruby�򥵥ݡ��Ȥ���ջ֤Ϥ���ޤ�
-    ����ruby���ȤΥХ����뤤��ruby������ץȤΥХ��ʤɤ���ȯ
-    �����뤤���ʤ�»�����Ф��Ƥ���Ǥ������ޤ���
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-* ����
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-�����ȡ��Х���ݡ��Ȥ���¾�� matz@netlab.co.jp �ޤǡ�
--------------------------------------------------------
-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..350b560905
--- /dev/null
+++ b/README.md
@@ -0,0 +1,171 @@
+[![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 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](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.  If `./configure` does not exist or is older than `configure.ac`, run
+    `autoconf` to (re)generate configure.
+
+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 3b6edee08f..0000000000
--- a/ToDo
+++ /dev/null
@@ -1,4 +0,0 @@
-* non-blocking open/write for thread
-* �ѥå������ޤ�������ѿ��Υ�����������
-* format��ǽ
-* re-write regex code for speed and copyright
diff --git a/aclocal.m4 b/aclocal.m4
new file mode 100644
index 0000000000..940d91e83f
--- /dev/null
+++ b/aclocal.m4
@@ -0,0 +1,48 @@
+# generated automatically by aclocal 1.16.2 -*- Autoconf -*-
+
+# 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.
+
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY, to the extent permitted by law; without
+# even the implied warranty of MERCHANTABILITY or FITNESS FOR A
+# PARTICULAR PURPOSE.
+
+m4_ifndef([AC_CONFIG_MACRO_DIRS], [m4_defun([_AM_CONFIG_MACRO_DIRS], [])m4_defun([AC_CONFIG_MACRO_DIRS], [_AM_CONFIG_MACRO_DIRS($@)])])
+m4_include([tool/m4/_colorize_result_prepare.m4])
+m4_include([tool/m4/ac_msg_result.m4])
+m4_include([tool/m4/colorize_result.m4])
+m4_include([tool/m4/ruby_append_option.m4])
+m4_include([tool/m4/ruby_append_options.m4])
+m4_include([tool/m4/ruby_check_builtin_func.m4])
+m4_include([tool/m4/ruby_check_builtin_setjmp.m4])
+m4_include([tool/m4/ruby_check_printf_prefix.m4])
+m4_include([tool/m4/ruby_check_setjmp.m4])
+m4_include([tool/m4/ruby_check_signedness.m4])
+m4_include([tool/m4/ruby_check_sizeof.m4])
+m4_include([tool/m4/ruby_check_sysconf.m4])
+m4_include([tool/m4/ruby_cppoutfile.m4])
+m4_include([tool/m4/ruby_decl_attribute.m4])
+m4_include([tool/m4/ruby_default_arch.m4])
+m4_include([tool/m4/ruby_define_if.m4])
+m4_include([tool/m4/ruby_defint.m4])
+m4_include([tool/m4/ruby_dtrace_available.m4])
+m4_include([tool/m4/ruby_dtrace_postprocess.m4])
+m4_include([tool/m4/ruby_func_attribute.m4])
+m4_include([tool/m4/ruby_mingw32.m4])
+m4_include([tool/m4/ruby_prepend_option.m4])
+m4_include([tool/m4/ruby_prog_gnu_ld.m4])
+m4_include([tool/m4/ruby_replace_funcs.m4])
+m4_include([tool/m4/ruby_replace_type.m4])
+m4_include([tool/m4/ruby_rm_recursive.m4])
+m4_include([tool/m4/ruby_setjmp_type.m4])
+m4_include([tool/m4/ruby_stack_grow_direction.m4])
+m4_include([tool/m4/ruby_try_cflags.m4])
+m4_include([tool/m4/ruby_try_cxxflags.m4])
+m4_include([tool/m4/ruby_try_ldflags.m4])
+m4_include([tool/m4/ruby_type_attribute.m4])
+m4_include([tool/m4/ruby_universal_arch.m4])
+m4_include([tool/m4/ruby_werror_flag.m4])
diff --git a/addr2line.c b/addr2line.c
new file mode 100644
index 0000000000..dc4364aaf5
--- /dev/null
+++ b/addr2line.c
@@ -0,0 +1,2716 @@
+/**********************************************************************
+
+  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 = *(unsigned char *)p++;
+	    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)
+{
+#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);
+#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__)
+static ssize_t
+main_exe_path(void)
+{
+# define PROC_SELF_EXE "/proc/self/exe"
+    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..d31d4b2df9
--- /dev/null
+++ b/appveyor.yml
@@ -0,0 +1,96 @@
+---
+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%"
+  zlib_version: "1.2.11"
+  matrix:
+    - build: vs
+      vs: 120
+      ssl: OpenSSL
+      APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2013
+      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=."
+for:
+-
+  matrix:
+    only:
+      - build: vs
+  install:
+    - ver
+    - chcp
+    - SET BITS=%Platform:x86=32%
+    - SET BITS=%BITS:x=%
+    - SET OPENSSL_DIR=C:\%ssl%-Win%BITS%
+    - 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
+    - SET ZLIB_ZIP=.downloaded-cache\zlib%zlib_version:.=%.zip
+    - if not exist %ZLIB_ZIP% curl -fsSL -o %ZLIB_ZIP% --retry 10 https://zlib.net/zlib%zlib_version:.=%.zip
+    - 7z x -aos -o%APPVEYOR_BUILD_FOLDER%\ext\zlib %ZLIB_ZIP%
+    - 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 --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 c1ad9981c1..ea84473fdf 100644
--- a/array.c
+++ b/array.c
@@ -1,1235 +1,8206 @@
-/************************************************
+/**********************************************************************
 
   array.c -
 
-  $Author: matz $
-  $Date: 1996/12/25 10:42:18 $
+  $Author$
   created at: Fri Aug  6 09:46:12 JST 1993
 
-  Copyright (C) 1993-1996 Yukihiro Matsumoto
+  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;
 
-#include "ruby.h"
+/* for OPTIMIZED_CMP: */
+#define id_cmp idCmp
 
-VALUE cArray;
+#define ARY_DEFAULT_SIZE 16
+#define ARY_MAX_SIZE (LONG_MAX / (int)sizeof(VALUE))
+#define SMALL_ARRAY_LEN 16
 
-VALUE rb_to_a();
+RBIMPL_ATTR_MAYBE_UNUSED()
+static int
+should_be_T_ARRAY(VALUE ary)
+{
+    return RB_TYPE_P(ary, T_ARRAY);
+}
 
-#define ARY_DEFAULT_SIZE 16
+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
-memclear(mem, size)
-    register VALUE *mem;
-    register int size;
+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_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;
     }
 }
 
-#define ARY_FREEZE   FL_USER1
+static void
+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;
+    }
+}
+
+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_modify(ary)
-    VALUE ary;
+ary_memcpy0(VALUE ary, long beg, long argc, const VALUE *argv, VALUE buff_owner_ary)
 {
-    rb_secure(5);
-    if (FL_TEST(ary, ARY_FREEZE)) {
-	TypeError("can't modify frozen array");
+    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]);
+            }
+        });
     }
 }
 
-VALUE
-ary_freeze(ary)
-    VALUE ary;
+static void
+ary_memcpy(VALUE ary, long beg, long argc, const VALUE *argv)
 {
-    FL_SET(ary, ARY_FREEZE);
-    return ary;
+    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
+ary_heap_free_ptr(VALUE ary, const VALUE *ptr, long size)
+{
+    if (RARRAY_TRANSIENT_P(ary)) {
+        /* ignore it */
+    }
+    else {
+        ruby_sized_xfree((void *)ptr, size);
+    }
+}
+
+static void
+ary_heap_free(VALUE 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
-ary_frozen_p(ary)
-    VALUE ary;
+rb_ary_increment_share(VALUE shared_root)
 {
-    if (FL_TEST(ary, ARY_FREEZE))
-	return TRUE;
-    return FALSE;
+    long num = ARY_SHARED_ROOT_REFCNT(shared_root);
+    if (num >= 0) {
+        ARY_SET_SHARED_ROOT_REFCNT(shared_root, num + 1);
+    }
+    return shared_root;
 }
 
-VALUE
-ary_new2(len)
-    int len;
+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)
 {
-    NEWOBJ(ary, struct RArray);
-    OBJSETUP(ary, cArray, T_ARRAY);
+    rb_check_frozen(ary);
+    ary_verify(ary);
+}
 
-    ary->len = 0;
-    ary->capa = len;
-    if (len == 0)
-	ary->ptr = 0;
+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 {
-	ary->ptr = ALLOC_N(VALUE, len);
-	memclear(ary->ptr, len);
+	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 (!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;
+}
 
+static VALUE
+ary_alloc(VALUE klass)
+{
+    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;
 }
 
+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 (capa > ARY_MAX_SIZE) {
+	rb_raise(rb_eArgError, "array size too big");
+    }
+
+    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
-ary_new()
+rb_ary_new_capa(long capa)
 {
-    return ary_new2(ARY_DEFAULT_SIZE);
+    return ary_new(rb_cArray, capa);
 }
 
-#include <varargs.h>
+VALUE
+rb_ary_new(void)
+{
+    return rb_ary_new2(RARRAY_EMBED_LEN_MAX);
+}
 
 VALUE
-ary_new3(n, va_alist)
-    int n;
-    va_dcl
+(rb_ary_new_from_args)(long n, ...)
 {
     va_list ar;
-    struct RArray* ary;
-    int i;
+    VALUE ary;
+    long i;
 
-    if (n < 0) {
-	IndexError("Negative number of items(%d)", n);
-    }
-    ary = (struct RArray*)ary_new2(n<ARY_DEFAULT_SIZE?ARY_DEFAULT_SIZE:n);
+    ary = rb_ary_new2(n);
 
-    va_start(ar);
+    va_start(ar, n);
     for (i=0; i<n; i++) {
-	ary->ptr[i] = va_arg(ar, VALUE);
+	ARY_SET(ary, i, va_arg(ar, VALUE));
     }
     va_end(ar);
 
-    ary->len = n;
+    ARY_SET_LEN(ary, n);
+    return ary;
+}
+
+MJIT_FUNC_EXPORTED VALUE
+rb_ary_tmp_new_from_values(VALUE klass, long n, const VALUE *elts)
+{
+    VALUE ary;
+
+    ary = ary_new(klass, n);
+    if (n > 0 && elts) {
+	ary_memcpy(ary, 0, n, elts);
+	ARY_SET_LEN(ary, n);
+    }
+
+    return ary;
+}
+
+VALUE
+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
-ary_new4(n, elts)
-    int n;
-    VALUE *elts;
+rb_ec_ary_new_from_values(rb_execution_context_t *ec, long n, const VALUE *elts)
 {
-    struct RArray* ary;
+    VALUE ary;
 
-    ary = (struct RArray*)ary_new2(n);
-    MEMCPY(ary->ptr, elts, VALUE, n);
-    ary->len = n;
+    ary = ec_ary_new(ec, rb_cArray, n);
+    if (n > 0 && elts) {
+	ary_memcpy(ary, 0, n, elts);
+	ARY_SET_LEN(ary, n);
+    }
 
-    return (VALUE)ary;
+    return ary;
 }
 
 VALUE
-assoc_new(car, cdr)
-    VALUE car, cdr;
+rb_ary_tmp_new(long capa)
 {
-    struct RArray* ary;
+    VALUE ary = ary_new(0, capa);
+    rb_ary_transient_heap_evacuate(ary, TRUE);
+    return ary;
+}
 
-    ary = (struct RArray*)ary_new2(2);
-    ary->ptr[0] = car;
-    ary->ptr[1] = cdr;
-    ary->len = 2;
+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;
+}
 
-    return (VALUE)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
-ary_s_new(argc, argv, class)
-    int argc;
-    VALUE *argv;
-    VALUE class;
+ary_make_shared(VALUE ary)
 {
-    VALUE size;
-    NEWOBJ(ary, struct RArray);
-    OBJSETUP(ary, class, T_ARRAY);
+    assert(!ARY_EMBED_P(ary));
+    ary_verify(ary);
 
-    rb_scan_args(argc, argv, "01", &size);
-    ary->len = 0;
-    ary->capa = NIL_P(size)?ARY_DEFAULT_SIZE:NUM2INT(size);
-    ary->ptr = ALLOC_N(VALUE, ary->capa);
-    memclear(ary->ptr, ary->capa);
+    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 {
+	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;
+    }
+}
 
-    return (VALUE)ary;
+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));
+    }
+}
+
+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_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
-ary_s_create(argc, argv, class)
-    int argc;
-    VALUE *argv;
-    VALUE class;
+rb_ary_initialize(int argc, VALUE *argv, VALUE ary)
 {
-    NEWOBJ(ary, struct RArray);
-    OBJSETUP(ary, class, 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;
+}
 
-    return (VALUE)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 ary;
 }
 
 void
-ary_store(ary, idx, val)
-    struct RArray *ary;
-    int idx;
-    VALUE val;
+rb_ary_store(VALUE ary, long idx, VALUE val)
 {
-    ary_modify(ary);
+    long len = RARRAY_LEN(ary);
+
     if (idx < 0) {
-	IndexError("negative index for array");
+	idx += len;
+	if (idx < 0) {
+	    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 >= ary->capa) {
-	ary->capa = idx + ARY_DEFAULT_SIZE;
-	REALLOC_N(ary->ptr, VALUE, ary->capa);
+    rb_ary_modify(ary);
+    if (idx >= ARY_CAPA(ary)) {
+	ary_double_capa(ary, idx);
     }
-    if (idx > ary->len) {
-	memclear(ary->ptr+ary->len, idx-ary->len+1);
+    if (idx > len) {
+	ary_mem_clear(ary, len, idx - len + 1);
     }
 
-    if (idx >= ary->len) {
-	ary->len = idx + 1;
+    if (idx >= len) {
+	ARY_SET_LEN(ary, idx + 1);
     }
-    ary->ptr[idx] = val;
+    ARY_SET(ary, idx, val);
 }
 
-VALUE
-ary_push(ary, item)
-    struct RArray *ary;
-    VALUE item;
+static VALUE
+ary_make_partial(VALUE ary, VALUE klass, long offset, long len)
 {
-    ary_store(ary, ary->len, item);
-    return (VALUE)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
-ary_push_method(argc, argv, ary)
-    int argc;
-    VALUE *argv;
-    struct RArray *ary;
+ary_make_partial_step(VALUE ary, VALUE klass, long offset, long len, long step)
 {
-    while (argc--) {
-	ary_store(ary, ary->len, *argv++);
+    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;
     }
-    return (VALUE)ary;
+
+    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;
 }
 
-VALUE
-ary_pop(ary)
-    struct RArray *ary;
+static VALUE
+ary_make_shared_copy(VALUE ary)
+{
+    return ary_make_partial(ary, rb_cArray, 0, RARRAY_LEN(ary));
+}
+
+enum ary_take_pos_flags
+{
+    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)
 {
-    if (ary->len == 0) return Qnil;
-    if (ary->len * 10 < ary->capa && ary->capa > ARY_DEFAULT_SIZE) {
-	ary->capa = ary->len * 2;
-	REALLOC_N(ary->ptr, VALUE, ary->capa);
+    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");
     }
-    return ary->ptr[--ary->len];
+    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
-ary_shift(ary)
-    struct RArray *ary;
+rb_ary_push(VALUE ary, VALUE item)
 {
-    VALUE top;
-
-    if (ary->len == 0) return Qnil;
+    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;
+}
 
-    top = ary->ptr[0];
-    ary->len--;
+VALUE
+rb_ary_cat(VALUE ary, const VALUE *argv, long 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;
+}
 
-    /* sliding items */
-    MEMMOVE(ary->ptr, ary->ptr+1, VALUE, ary->len);
-    if (ary->len * 10 < ary->capa && ary->capa > ARY_DEFAULT_SIZE) {
-	ary->capa = ary->len * 2;
-	REALLOC_N(ary->ptr, VALUE, ary->capa);
-    }
+/*
+ *  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.
+ */
 
-    return top;
+static VALUE
+rb_ary_push_m(int argc, VALUE *argv, VALUE ary)
+{
+    return rb_ary_cat(ary, argv, argc);
 }
 
 VALUE
-ary_unshift(ary, item)
-    struct RArray *ary;
-    int item;
+rb_ary_pop(VALUE ary)
 {
-    ary_modify(ary);
-    if (ary->len >= ary->capa) {
-	ary->capa+=ARY_DEFAULT_SIZE;
-	REALLOC_N(ary->ptr, VALUE, ary->capa);
+    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);
+}
+
+/*
+ *  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.
+ */
+
+static VALUE
+rb_ary_pop_m(int argc, VALUE *argv, VALUE ary)
+{
+    VALUE result;
 
-    /* sliding items */
-    MEMMOVE(ary->ptr+1, ary->ptr, VALUE, ary->len);
+    if (argc == 0) {
+	return rb_ary_pop(ary);
+    }
 
-    ary->len++;
-    return ary->ptr[0] = item;
+    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
-ary_entry(ary, offset)
-    struct RArray *ary;
-    int offset;
+rb_ary_shift(VALUE ary)
 {
-    if (ary->len == 0) return Qnil;
+    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;
+	}
+        assert(!ARY_EMBED_P(ary)); /* ARY_EMBED_LEN_MAX < ARY_DEFAULT_SIZE */
 
-    if (offset < 0) {
-	offset = ary->len + offset;
+	ARY_SET(ary, 0, Qnil);
+	ary_make_shared(ary);
     }
-    if (offset < 0 || ary->len <= offset) {
-	return Qnil;
+    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);
 
-    return ary->ptr[offset];
+    ary_verify(ary);
+
+    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
-ary_subseq(ary, beg, len)
-    struct RArray *ary;
-    int beg, len;
+rb_ary_shift_m(int argc, VALUE *argv, VALUE ary)
 {
-    struct RArray *ary2;
+    VALUE result;
+    long n;
 
-    if (beg < 0) {
-	beg = ary->len + beg;
-	if (beg < 0) beg = 0;
+    if (argc == 0) {
+	return rb_ary_shift(ary);
     }
-    if (len < 0) {
-	IndexError("negative length %d", ary->len);
+
+    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);
     }
-    if (len == 0) {
-	return ary_new2(0);
+    ARY_INCREASE_PTR(ary, n);
+    ARY_INCREASE_LEN(ary, -n);
+    ary_verify(ary);
+    return ary;
+}
+
+static VALUE
+behead_transient(VALUE ary, long n)
+{
+    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;
+}
+
+MJIT_FUNC_EXPORTED VALUE
+rb_ary_behead(VALUE ary, long n)
+{
+    if (n <= 0) {
+        return ary;
+    }
+    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);
     }
-    if (beg + len > ary->len) {
-	len = ary->len - beg;
+    else {
+        return behead_transient(ary, n);
     }
+}
 
-    ary2 = (struct RArray*)ary_new2(len);
-    MEMCPY(ary2->ptr, ary->ptr+beg, VALUE, len);
-    ary2->len = len;
+static VALUE
+make_room_for_unshift(VALUE ary, const VALUE *head, VALUE *sharedp, int argc, long capa, long len)
+{
+    if (head - sharedp < argc) {
+        long room = capa - len - argc;
 
-    return (VALUE)ary2;
+        room -= room >> 4;
+        MEMMOVE((VALUE *)sharedp + argc + room, head, VALUE, len);
+        head = sharedp + argc + room;
+    }
+    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
-beg_len(range, begp, lenp, len)
-    VALUE range;
-    int *begp, *lenp;
-    int len;
+ary_modify_for_unshift(VALUE ary, int argc)
 {
-    int beg, end;
+    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 (!range_beg_end(range, &beg, &end)) return FALSE;
+    /* use shared array for big "queues" */
+    if (new_len > ARY_DEFAULT_SIZE * 4) {
+        ary_verify(ary);
 
-    if ((beg > 0 && end > 0 || beg < 0 && end < 0) && beg > end) {
-	IndexError("end smaller than beg [%d..%d]", beg, end);
+        /* 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);
     }
+    else {
+	/* sliding items */
+        RARRAY_PTR_USE_TRANSIENT(ary, ptr, {
+	    MEMMOVE(ptr + argc, ptr, VALUE, len);
+	});
 
-    if (beg < 0) {
-	beg = len + beg;
-	if (beg < 0) beg = 0;
+        ary_verify(ary);
+	return ary;
     }
-    *begp = beg;
-    if (beg > len) {
-	*lenp = 0;
+}
+
+static VALUE
+ary_ensure_room_for_unshift(VALUE ary, int argc)
+{
+    long len = RARRAY_LEN(ary);
+    long new_len = len + argc;
+
+    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 {
-	if (end < 0) {
-	    end = len + end;
-	    if (end < 0) end = -1;
-	}
-	if (end > len) end = len;
-	if (beg > end) {
-	    *lenp = 0;
-	}
-	else {
-	    *lenp = end - beg +1;
-	}
+        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);
+        }
     }
-    return TRUE;
 }
 
+/*
+ *  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
-ary_aref(argc, argv, ary)
-    int argc;
-    VALUE *argv;
-    struct RArray *ary;
+rb_ary_unshift_m(int argc, VALUE *argv, VALUE ary)
 {
-    VALUE arg1, arg2;
-    int beg, len;
+    long len = RARRAY_LEN(ary);
+    VALUE target_ary;
 
-    if (rb_scan_args(argc, argv, "11", &arg1, &arg2) == 2) {
-	beg = NUM2INT(arg1);
-	len = NUM2INT(arg2);
-	if (len <= 0) {
-	    return ary_new();
-	}
-	return ary_subseq(ary, beg, len);
+    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)
+{
+    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#[].
+ */
+
+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 += RARRAY_LEN(ary);
+    }
+    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(arg1)) {
-	return ary_entry(ary, FIX2INT(arg1));
+    if (FIXNUM_P(arg)) {
+	return rb_ary_entry(ary, FIX2LONG(arg));
+    }
+    /* 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);
+    }
+
+    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 {
-	/* check if idx is Range */
-	if (beg_len(arg1, &beg, &len, ary->len)) {
-	    return ary_subseq(ary, beg, len);
-	}
+	return ary_take_first_or_last(argc, argv, ary, ARY_TAKE_FIRST);
     }
-    if (TYPE(arg1) == T_BIGNUM) {
-	IndexError("index too big");
+}
+
+/*
+ *  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_last(int argc, const VALUE *argv, VALUE ary)
+{
+    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);
     }
-    return ary_entry(ary, NUM2INT(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
-ary_index(ary, val)
-    struct RArray *ary;
-    VALUE val;
+rb_ary_fetch(int argc, VALUE *argv, VALUE ary)
 {
-    int i;
+    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");
+    }
+    idx = NUM2LONG(pos);
 
-    for (i=0; i<ary->len; i++) {
-	if (rb_equal(ary->ptr[i], val))
-	    return INT2FIX(i);
+    if (idx < 0) {
+	idx +=  RARRAY_LEN(ary);
     }
-    return Qnil;
+    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 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
-ary_indexes(ary, args)
-    struct RArray *ary, *args;
+rb_ary_index(int argc, VALUE *argv, VALUE ary)
 {
-    VALUE *p, *pend;
-    VALUE new_ary;
-    int i = 0;
+    VALUE val;
+    long i;
 
-    if (!args || NIL_P(args)) {
-	return ary_new2(0);
+    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;
+}
 
-    new_ary = ary_new2(args->len);
+/*
+ *  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.
+ */
 
-    p = args->ptr; pend = p + args->len;
-    while (p < pend) {
-	ary_store(new_ary, i++, ary_entry(ary, NUM2INT(*p)));
-	p++;
+static VALUE
+rb_ary_rindex(int argc, VALUE *argv, VALUE ary)
+{
+    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;
     }
-    return new_ary;
+    rb_check_arity(argc, 0, 1);
+    val = argv[0];
+    if (rb_block_given_p())
+	rb_warn("given block not used");
+    while (i--) {
+	VALUE e = RARRAY_AREF(ary, i);
+	if (rb_equal(e, val)) {
+	    return LONG2NUM(i);
+	}
+        if (i > RARRAY_LEN(ary)) {
+            break;
+        }
+    }
+    return Qnil;
+}
+
+VALUE
+rb_ary_to_ary(VALUE obj)
+{
+    VALUE tmp = rb_check_array_type(obj);
+
+    if (!NIL_P(tmp)) return tmp;
+    return rb_ary_new3(1, obj);
 }
 
 static void
-ary_replace(ary, beg, len, rpl)
-    struct RArray *ary, *rpl;
-    int beg, len;
+rb_ary_splice(VALUE ary, long beg, long len, const VALUE *rptr, long rlen)
 {
-    ary_modify(ary);
-    if (TYPE(rpl) != T_ARRAY) {
-	rpl = (struct RArray*)rb_to_a(rpl);
-    }
+    long olen;
+    long rofs;
+
+    if (len < 0) rb_raise(rb_eIndexError, "negative length (%ld)", len);
+    olen = RARRAY_LEN(ary);
     if (beg < 0) {
-	beg = ary->len + beg;
-	if (beg < 0) beg = 0;
+	beg += olen;
+	if (beg < 0) {
+	    rb_raise(rb_eIndexError, "index %ld too small for array; minimum: %ld",
+		     beg - olen, -olen);
+	}
+    }
+    if (olen < len || olen < beg + len) {
+	len = olen - beg;
     }
-    if (beg >= ary->len) {
-	len = beg + rpl->len;
-	if (len >= ary->capa) {
-	    ary->capa=len;
-	    REALLOC_N(ary->ptr, VALUE, ary->capa);
+
+    {
+        const VALUE *optr = RARRAY_CONST_PTR_TRANSIENT(ary);
+	rofs = (rptr >= optr && rptr < optr + olen) ? rptr - optr : -1;
+    }
+
+    if (beg >= olen) {
+	VALUE target_ary;
+	if (beg > ARY_MAX_SIZE - rlen) {
+	    rb_raise(rb_eIndexError, "index %ld too big", beg);
+	}
+	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);
 	}
-	memclear(ary->ptr+ary->len, beg-ary->len);
-	MEMCPY(ary->ptr+beg, rpl->ptr, VALUE, rpl->len);
-	ary->len = len;
+	ARY_SET_LEN(ary, len);
     }
     else {
-	int alen;
+	long alen;
 
-	if (beg + len > ary->len) {
-	    len = ary->len - beg;
+	if (olen - len > ARY_MAX_SIZE - rlen) {
+	    rb_raise(rb_eIndexError, "index %ld too big", olen + rlen - len);
 	}
-	if (len < 0) {
-	    IndexError("negative length %d", ary->len);
+	rb_ary_modify(ary);
+	alen = olen + rlen - len;
+	if (alen >= ARY_CAPA(ary)) {
+	    ary_double_capa(ary, alen);
 	}
 
-	alen = ary->len + rpl->len - len;
-	if (alen >= ary->capa) {
-	    ary->capa=alen;
-	    REALLOC_N(ary->ptr, VALUE, 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));
+	}
+    }
+}
 
-	if (len != RARRAY(rpl)->len) {
-	    MEMMOVE(ary->ptr+beg+rpl->len, ary->ptr+beg+len,
-		    VALUE, ary->len-(beg+len));
-	    ary->len = alen;
+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;
+
+    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);
+	}
+	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);
 	}
-	MEMCPY(ary->ptr+beg, rpl->ptr, VALUE, rpl->len);
+	ARY_SET_HEAP_LEN(ary, len);
     }
+    ary_verify(ary);
+    return ary;
+}
+
+static VALUE
+ary_aset_by_rb_ary_store(VALUE ary, long key, VALUE val)
+{
+    rb_ary_store(ary, key, val);
+    return val;
 }
 
 static VALUE
-ary_aset(argc, argv, ary)
-    int argc;
-    VALUE *argv;
-    struct RArray *ary;
+ary_aset_by_rb_ary_splice(VALUE ary, long beg, long len, VALUE val)
 {
-    VALUE arg1, arg2;
-    struct RArray *arg3;
-    int offset;
-    int beg, len;
+    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 (rb_scan_args(argc, argv, "21", &arg1, &arg2, &arg3) == 3) {
-	beg = NUM2INT(arg1);
-	len = NUM2INT(arg2);
-	ary_replace(ary, beg, len, arg3);
-	return (VALUE)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, ary->len)) {
+    if (rb_range_beg_len(argv[0], &beg, &len, RARRAY_LEN(ary), 1)) {
 	/* check if idx is Range */
-	ary_replace(ary, beg, len, arg2);
-	return arg2;
-    }
-    if (TYPE(arg1) == T_BIGNUM) {
-	IndexError("index too big");
+        return ary_aset_by_rb_ary_splice(ary, beg, len, argv[1]);
     }
 
-    offset = NUM2INT(arg1);
-  fixnum:
-    if (offset < 0) {
-	offset = ary->len + offset;
+    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);
     }
-    ary_store(ary, offset, arg2);
-    return arg2;
+    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;
 }
 
-VALUE
-ary_each(ary)
-    struct RArray *ary;
+static VALUE
+rb_ary_length(VALUE ary);
+
+static VALUE
+ary_enum_length(VALUE ary, VALUE args, VALUE eobj)
 {
-    int i;
+    return rb_ary_length(ary);
+}
 
-    for (i=0; i<ary->len; i++) {
-	rb_yield(ary->ptr[i]);
+/*
+ *  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(VALUE ary)
+{
+    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
-ary_each_index(ary)
-    struct RArray *ary;
+rb_ary_each_index(VALUE ary)
 {
-    int i;
+    long i;
+    RETURN_SIZED_ENUMERATOR(ary, 0, 0, ary_enum_length);
 
-    for (i=0; i<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
-ary_reverse_each(ary)
-    struct RArray *ary;
+rb_ary_reverse_each(VALUE ary)
 {
-    int len = ary->len;
+    long len;
 
+    RETURN_SIZED_ENUMERATOR(ary, 0, 0, ary_enum_length);
+    len = RARRAY_LEN(ary);
     while (len--) {
-	rb_yield(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
-ary_length(ary)
-    struct RArray *ary;
+rb_ary_length(VALUE ary)
 {
-    return INT2FIX(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
-ary_empty_p(ary)
-    struct RArray *ary;
+rb_ary_empty_p(VALUE ary)
 {
-    if (ary->len == 0)
-	return TRUE;
-    return FALSE;
+    if (RARRAY_LEN(ary) == 0)
+	return Qtrue;
+    return Qfalse;
 }
 
+VALUE
+rb_ary_dup(VALUE ary)
+{
+    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;
+}
+
+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
-ary_clone(ary)
-    struct RArray *ary;
+recursive_join(VALUE obj, VALUE argp, int recur)
+{
+    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 long
+ary_join_0(VALUE ary, VALUE sep, long max, VALUE result)
 {
-    VALUE ary2 = ary_new2(ary->len);
+    long i;
+    VALUE val;
 
-    CLONESETUP(ary2, ary);
-    MEMCPY(RARRAY(ary2)->ptr, ary->ptr, VALUE, ary->len);
-    RARRAY(ary2)->len = ary->len;
-    return ary2;
+    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 OFS;
+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 void
+ary_join_1_ary(VALUE obj, VALUE ary, VALUE sep, VALUE result, VALUE val, int *first)
+{
+    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);
+    }
+}
+
+static void
+ary_join_1(VALUE obj, VALUE ary, VALUE sep, long i, VALUE result, int *first)
+{
+    VALUE val, tmp;
+
+    for (; i<RARRAY_LEN(ary); i++) {
+	if (i > 0 && !NIL_P(sep))
+	    rb_str_buf_append(result, sep);
+
+	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);
+	}
+    }
+}
 
 VALUE
-ary_join(ary, sep)
-    struct RArray *ary;
-    struct RString *sep;
+rb_ary_join(VALUE ary, VALUE sep)
 {
-    int i;
-    VALUE result, tmp;
-    if (ary->len == 0) return str_new(0, 0);
+    long len = 1, i;
+    VALUE val, tmp, result;
 
-    if (TYPE(ary->ptr[0]) == T_STRING)
-	result = str_dup(ary->ptr[0]);
-    else
-	result = obj_as_string(ary->ptr[0]);
+    if (RARRAY_LEN(ary) == 0) return rb_usascii_str_new(0, 0);
 
-    for (i=1; i<ary->len; i++) {
-	tmp = ary->ptr[i];
-	switch (TYPE(tmp)) {
-	  case T_STRING:
-	    break;
-	  case T_ARRAY:
-	    tmp = ary_join(tmp, sep);
-	    break;
-	  default:
-	    tmp = obj_as_string(tmp);
+    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)) str_cat(result, sep->ptr, sep->len);
-	str_cat(result, RSTRING(tmp)->ptr, RSTRING(tmp)->len);
-	if (str_tainted(tmp)) str_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
-ary_join_method(argc, argv, ary)
-    int argc;
-    VALUE *argv;
-    struct RArray *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 = OFS;
-    if (!NIL_P(sep)) Check_Type(sep, T_STRING);
+    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 ary_join(ary, sep);
+    return rb_ary_join(ary, sep);
 }
 
-VALUE
-ary_to_s(ary)
-    VALUE ary;
+static VALUE
+inspect_ary(VALUE ary, VALUE dummy, int recur)
 {
-    VALUE str = ary_join(ary, OFS);
-    if (NIL_P(str)) return str_new(0, 0);
+    long i;
+    VALUE s, str;
+
+    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;
 }
 
+/*
+ *  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.
+ */
+
+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
-ary_print_on(ary, port)
-    struct RArray *ary;
-    VALUE port;
+rb_ary_to_s(VALUE ary)
 {
-    int i;
+    return rb_ary_inspect(ary);
+}
 
-    for (i=0; i<ary->len; i++) {
-	if (!NIL_P(OFS) && i>0) {
-	    io_write(port, OFS);
-	}
-	io_write(port, ary->ptr[i]);
+/*
+ *  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
+rb_ary_to_a(VALUE ary)
+{
+    if (rb_obj_class(ary) != rb_cArray) {
+	VALUE dup = rb_ary_new2(RARRAY_LEN(ary));
+	rb_ary_replace(dup, ary);
+	return dup;
     }
-    return port;
+    return ary;
 }
 
+/*
+ *  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
-ary_inspect(ary)
-    struct RArray *ary;
+rb_ary_to_h(VALUE ary)
 {
-    int i, len;
-    VALUE s, str;
+    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;
+}
 
-    if (ary->len == 0) return str_new2("[]");
-    str = str_new2("[");
-    len = 1;
+/*
+ *  call-seq:
+ *    array.to_ary -> self
+ *
+ *  Returns +self+.
+ */
 
-    for (i=0; i<ary->len; i++) {
-	s = rb_inspect(ary->ptr[i]);
-	if (i > 0) str_cat(str, ", ", 2);
-	str_cat(str, RSTRING(s)->ptr, RSTRING(s)->len);
-	len += RSTRING(s)->len + 2;
+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;
     }
-    str_cat(str, "]", 1);
+}
 
-    return str;
+VALUE
+rb_ary_reverse(VALUE ary)
+{
+    VALUE *p2;
+    long len = RARRAY_LEN(ary);
+
+    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
-ary_to_a(ary)
-    VALUE ary;
+rb_ary_reverse_bang(VALUE ary)
 {
-    return ary;
+    return rb_ary_reverse(ary);
 }
 
-VALUE
-rb_to_a(obj)
-    VALUE obj;
+/*
+ *  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"]
+ */
+
+static VALUE
+rb_ary_reverse_m(VALUE ary)
 {
-    if (TYPE(obj) == T_ARRAY) return obj;
-    obj = rb_funcall(obj, rb_intern("to_a"), 0);
-    if (TYPE(obj) != T_ARRAY) {
-	Bug("`to_a' did not return Array");
+    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);
     }
-    return obj;
+    ARY_SET_LEN(dup, RARRAY_LEN(ary));
+    return dup;
 }
 
-VALUE
-ary_reverse(ary)
-    struct RArray *ary;
+static inline long
+rotate_count(long cnt, long len)
 {
-    VALUE *p1, *p2;
-    VALUE tmp;
+    return (cnt < 0) ? (len - (~cnt % len) - 1) : (cnt % len);
+}
 
-    p1 = ary->ptr;
-    p2 = p1 + ary->len - 1;	/* points last item */
+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);
+    }
+}
 
-    while (p1 < p2) {
-	tmp = *p1;
-	*p1 = *p2;
-	*p2 = tmp;
-	p1++; p2--;
+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;
+}
 
-    return (VALUE)ary;
+/*
+ *  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_rotate_bang(int argc, VALUE *argv, VALUE ary)
+{
+    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
-ary_reverse_method(ary)
-    struct RArray *ary;
+rb_ary_rotate_m(int argc, VALUE *argv, VALUE ary)
 {
-    return ary_reverse(ary_clone(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;
 }
 
-static ID cmp;
+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(a, b)
-    VALUE *a, *b;
+sort_1(const void *ap, const void *bp, void *dummy)
 {
-    VALUE retval = rb_yield(assoc_new(*a, *b));
-    return NUM2INT(retval);
+    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(a, b)
-    VALUE *a, *b;
+sort_2(const void *ap, const void *bp, void *dummy)
 {
-    VALUE retval;
+    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)) {
-	if (FIXNUM_P(*b)) return *a - *b;
+    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);
     }
-    else if (TYPE(*a) == T_STRING) {
-	if (TYPE(*b) == T_STRING) return str_cmp(*a, *b);
+    if (RB_FLOAT_TYPE_P(a) && CMP_OPTIMIZABLE(data->cmp_opt, Float)) {
+	return rb_float_cmp(a, b);
     }
 
-    retval = rb_funcall(*a, cmp, 1, *b);
-    return NUM2INT(retval);
+    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
-ary_sort_bang(ary)
-    struct RArray *ary;
+rb_ary_sort_bang(VALUE ary)
 {
-    ary_modify(ary);
-    qsort(ary->ptr, ary->len, sizeof(VALUE), iterator_p()?sort_1:sort_2);
-    return (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_sort(VALUE ary)
+{
+    ary = rb_ary_dup(ary);
+    rb_ary_sort_bang(ary);
+    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>
+ */
+
+static VALUE
+rb_ary_bsearch(VALUE ary)
+{
+    VALUE index_result = rb_ary_bsearch_index(ary);
+
+    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_collect(VALUE 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;
+}
+
+
+/*
+ *  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)
+{
+    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;
 }
 
 VALUE
-ary_sort(ary)
+rb_get_values_at(VALUE obj, long olen, int argc, const VALUE *argv, VALUE (*func) (VALUE, long))
+{
+    VALUE result = rb_ary_new2(argc);
+    long beg, len, i, j;
+
+    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])));
+    }
+    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]
+ */
+
+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
+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)
+{
+    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
+select_bang_ensure(VALUE a)
+{
+    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;
+	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;
+}
+
+/*
+ *  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)
 {
-    return ary_sort_bang(ary_clone(ary));
+    struct select_bang_arg args;
+
+    RETURN_SIZED_ENUMERATOR(ary, 0, 0, ary_enum_length);
+    rb_ary_modify(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;
+}
+
+static void
+ary_resize_smaller(VALUE ary, long len)
+{
+    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
-ary_delete(ary, item)
-    struct RArray *ary;
-    VALUE item;
+rb_ary_delete(VALUE ary, VALUE item)
 {
-    int i1, i2;
+    VALUE v = item;
+    long i1, i2;
+
+    for (i1 = i2 = 0; i1 < RARRAY_LEN(ary); i1++) {
+	VALUE e = RARRAY_AREF(ary, i1);
 
-    ary_modify(ary);
-    for (i1 = i2 = 0; i1 < ary->len; i1++) {
-	if (rb_equal(ary->ptr[i1], item)) continue;
+	if (rb_equal(e, item)) {
+	    v = e;
+	    continue;
+	}
 	if (i1 != i2) {
-	    ary->ptr[i2] = ary->ptr[i1];
+	    rb_ary_store(ary, i2, e);
 	}
 	i2++;
     }
-    if (ary->len == i2) {
-	if (iterator_p()) rb_yield(item);
+    if (RARRAY_LEN(ary) == i2) {
+	if (rb_block_given_p()) {
+	    return rb_yield(item);
+	}
 	return Qnil;
     }
-    else {
-	ary->len = i2;
-    }
 
-    return item;
+    ary_resize_smaller(ary, i2);
+
+    ary_verify(ary);
+    return v;
 }
 
-VALUE
-ary_delete_at(ary, at)
-    struct RArray *ary;
-    VALUE at;
-{
-    int i1, i2, pos;
-    VALUE del = Qnil;
-
-    ary_modify(ary);
-    pos = NUM2INT(at);
-    for (i1 = i2 = 0; i1 < ary->len; i1++) {
-	if (i1 == pos) {
-	    del = ary->ptr[i1];
+void
+rb_ary_delete_same(VALUE ary, VALUE item)
+{
+    long i1, i2;
+
+    for (i1 = i2 = 0; i1 < RARRAY_LEN(ary); i1++) {
+	VALUE e = RARRAY_AREF(ary, i1);
+
+	if (e == item) {
 	    continue;
 	}
 	if (i1 != i2) {
-	    ary->ptr[i2] = ary->ptr[i1];
+	    rb_ary_store(ary, i2, e);
 	}
 	i2++;
     }
-    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_at_m(VALUE ary, VALUE pos)
+{
+    return rb_ary_delete_at(ary, NUM2LONG(pos));
+}
+
+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;
+    }
+    else 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;
+	}
+    }
+
+    return rb_ary_delete_at(ary, NUM2LONG(arg1));
+}
+
+static VALUE
+ary_reject(VALUE orig, VALUE result)
+{
+    long 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 result;
+}
+
 static VALUE
-ary_delete_if(ary)
-    struct RArray *ary;
+reject_bang_i(VALUE a)
 {
-    int i1, i2;
+    volatile struct select_bang_arg *arg = (void *)a;
+    VALUE ary = arg->ary;
+    long i1, i2;
 
-    ary_modify(ary);
-    for (i1 = i2 = 0; i1 < ary->len; i1++) {
-	if (rb_yield(ary->ptr[i1])) continue;
+    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) {
-	    ary->ptr[i2] = ary->ptr[i1];
+	    rb_ary_store(ary, i2, v);
 	}
-	i2++;
+	arg->len[1] = ++i2;
     }
-    ary->len = i2;
+    return (i1 == i2) ? Qnil : ary;
+}
 
-    return (VALUE)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);
 }
 
-#if 0
+/*
+ *  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
-ary_replace(ary)
-    struct RArray *ary;
+rb_ary_reject_bang(VALUE ary)
 {
-    int i;
+    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
+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]
+ */
 
-    for (i = 0; i < ary->len; i++) {
-	ary->ptr[i] = rb_yield(ary->ptr[i]);
+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);
     }
 
-    return (VALUE)ary;
+    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;
 }
-#endif
+
+/*
+ *  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
-ary_clear(ary)
-    struct RArray *ary;
+rb_ary_transpose(VALUE ary)
 {
-    ary->len = 0;
-    if (ARY_DEFAULT_SIZE*3 < ary->capa) {
-	ary->capa = ARY_DEFAULT_SIZE * 2;
-	REALLOC_N(ary->ptr, VALUE, 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 (VALUE)ary;
+    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
-ary_fill(argc, argv, ary)
-    int argc;
-    VALUE *argv;
-    struct RArray *ary;
+rb_ary_fill(int argc, VALUE *argv, VALUE ary)
 {
-    VALUE item, arg1, arg2;
-    int beg, len, end;
-    VALUE *p, *pend;
+    VALUE item = Qundef, arg1, arg2;
+    long beg = 0, end = 0, len = 0;
 
-    rb_scan_args(argc, argv, "12", &item, &arg1, &arg2);
-    if (NIL_P(arg2) && beg_len(arg1, &beg, &len, 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 = 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 = ary->len + beg;
+	    beg = RARRAY_LEN(ary) + beg;
 	    if (beg < 0) beg = 0;
 	}
-	if (arg2) {
-	    len = NUM2INT(arg2);
-	}
-	else {
-	    len = ary->len - beg;
-	}
+	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 > ary->len) {
-	if (end >= ary->capa) {
-	    ary->capa=end;
-	    REALLOC_N(ary->ptr, VALUE, ary->capa);
+    if (RARRAY_LEN(ary) < end) {
+	if (end >= ARY_CAPA(ary)) {
+	    ary_resize_capa(ary, end);
 	}
-	if (beg > ary->len) {
-	    memclear(ary->ptr+ary->len, end-ary->len);
+	ary_mem_clear(ary, RARRAY_LEN(ary), end - RARRAY_LEN(ary));
+	ARY_SET_LEN(ary, end);
+    }
+
+    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);
 	}
-	ary->len = end;
     }
-    p = ary->ptr + beg; pend = p + len;
+    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(VALUE x, VALUE y)
+{
+    VALUE z;
+    long len, xlen, ylen;
+
+    y = to_ary(y);
+    xlen = RARRAY_LEN(x);
+    ylen = RARRAY_LEN(y);
+    len = xlen + ylen;
+    z = rb_ary_new2(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;
+}
 
-    while (p < pend) {
-	*p++ = item;
+static VALUE
+ary_append(VALUE x, VALUE y)
+{
+    long n = RARRAY_LEN(y);
+    if (n > 0) {
+        rb_ary_splice(x, RARRAY_LEN(x), 0, RARRAY_CONST_PTR_TRANSIENT(y), n);
     }
-    return (VALUE)ary;
+    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]
+ */
+
+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]);
+    }
+    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
-ary_plus(x, y)
-    struct RArray *x, *y;
+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(VALUE ary, VALUE times)
 {
-    struct RArray *z;
+    VALUE ary2, tmp;
+    const VALUE *ptr;
+    long t, len;
 
-    if (TYPE(y) != T_ARRAY) {
-	return ary_plus(x, rb_to_a(y));
+    tmp = rb_check_string_type(times);
+    if (!NIL_P(tmp)) {
+	return rb_ary_join(ary, tmp);
     }
 
-    z = (struct RArray*)ary_new2(x->len + y->len);
-    MEMCPY(z->ptr, x->ptr, VALUE, x->len);
-    MEMCPY(z->ptr+x->len, y->ptr, VALUE, y->len);
-    z->len = x->len + RARRAY(y)->len;
-    return (VALUE)z;
+    len = NUM2LONG(times);
+    if (len == 0) {
+        ary2 = ary_new(rb_cArray, 0);
+	goto out;
+    }
+    if (len < 0) {
+	rb_raise(rb_eArgError, "negative argument");
+    }
+    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
-ary_concat(x, y)
-    struct RArray *x, *y;
+rb_ary_assoc(VALUE ary, VALUE key)
 {
-    VALUE *p, *pend;
+    long i;
+    VALUE v;
+
+    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.
+ */
 
-    if (TYPE(y) != T_ARRAY) {
-	return ary_concat(x, rb_to_a(y));
+VALUE
+rb_ary_rassoc(VALUE ary, VALUE value)
+{
+    long i;
+    VALUE v;
+
+    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
+recursive_equal(VALUE ary1, VALUE ary2, int recur)
+{
+    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;
+}
+
+/*
+ *  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>.
+ */
 
-    p = y->ptr;
-    pend = p + y->len;
-    while (p < pend) {
-	ary_store(x, x->len, *p);
-	p++;
+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 (VALUE)x;
+    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
-ary_times(ary, times)
-    struct RArray *ary;
-    VALUE times;
+recursive_eql(VALUE ary1, VALUE ary2, int recur)
 {
-    struct RArray *ary2;
-    int i, len;
+    long i;
 
-    if (TYPE(times) == T_STRING) {
-	return ary_join(ary, times);
+    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;
+}
 
-    len = NUM2INT(times) * ary->len;
-    ary2 = (struct RArray*)ary_new2(len);
-    ary2->len = len;
+/*
+ *  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>.
+ */
 
-    if (len < 0) {
-	ArgError("negative argument");
+static VALUE
+rb_ary_eql(VALUE ary1, VALUE ary2)
+{
+    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);
+}
+
+/*
+ *  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));
     }
+    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
+ */
 
-    for (i=0; i<len; i+=ary->len) {
-	MEMCPY(ary2->ptr+i, ary->ptr, VALUE, ary->len);
+VALUE
+rb_ary_includes(VALUE ary, VALUE 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;
+	}
     }
+    return Qfalse;
+}
+
+static VALUE
+rb_ary_includes_by_eql(VALUE ary, VALUE item)
+{
+    long i;
+    VALUE e;
 
-    return (VALUE)ary2;
+    for (i=0; i<RARRAY_LEN(ary); i++) {
+	e = RARRAY_AREF(ary, i);
+	if (rb_eql(item, e)) {
+	    return Qtrue;
+	}
+    }
+    return Qfalse;
 }
 
-VALUE
-ary_assoc(ary, key)
-    struct RArray *ary;
-    VALUE key;
+static VALUE
+recursive_cmp(VALUE ary1, VALUE ary2, int recur)
 {
-    VALUE *p, *pend;
+    long i, len;
 
-    p = ary->ptr; pend = p + ary->len;
-    while (p < pend) {
-	if (TYPE(*p) == T_ARRAY
-	    && RARRAY(*p)->len > 1
-	    && rb_equal(RARRAY(*p)->ptr[0], key))
-	    return *p;
-	p++;
+    if (recur) return Qundef;	/* Subtle! */
+    len = RARRAY_LEN(ary1);
+    if (len > RARRAY_LEN(ary2)) {
+	len = RARRAY_LEN(ary2);
     }
-    return Qnil;
+    for (i=0; i<len; 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;
+	}
+    }
+    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
-ary_rassoc(ary, value)
-    struct RArray *ary;
-    VALUE value;
+rb_ary_cmp(VALUE ary1, VALUE ary2)
 {
-    VALUE *p, *pend;
+    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);
+}
 
-    p = ary->ptr; pend = p + ary->len;
-    while (p < pend) {
-	if (TYPE(*p) == T_ARRAY
-	    && RARRAY(*p)->len > 1
-	    && rb_equal(RARRAY(*p)->ptr[1], value))
-	    return *p;
-	p++;
+static VALUE
+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 Qnil;
+    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_equal(ary1, ary2)
-    struct RArray *ary1, *ary2;
+ary_make_hash(VALUE ary)
 {
-    int i;
+    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;
 
-    if (TYPE(ary2) != T_ARRAY) return FALSE;
-    if (ary1->len != ary2->len) return FALSE;
-    for (i=0; i<ary1->len; i++) {
-	if (!rb_equal(ary1->ptr[i], ary2->ptr[i]))
-	    return FALSE;
+    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 TRUE;
+    return hash;
 }
 
 static VALUE
-ary_eql(ary1, ary2)
-    struct RArray *ary1, *ary2;
+ary_make_hash_by(VALUE ary)
 {
-    int i;
+    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.
+ */
 
-    if (TYPE(ary2) != T_ARRAY) return FALSE;
-    if (ary1->len != ary2->len) return FALSE;
-    for (i=0; i<ary1->len; i++) {
-	if (!rb_eql(ary1->ptr[i], ary2->ptr[i]))
-	    return FALSE;
+static VALUE
+rb_ary_diff(VALUE ary1, VALUE ary2)
+{
+    VALUE ary3;
+    VALUE hash;
+    long i;
+
+    ary2 = to_ary(ary2);
+    ary3 = rb_ary_new();
+
+    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;
     }
-    return TRUE;
+
+    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
-ary_hash(ary)
-    struct RArray *ary;
+rb_ary_difference_multi(int argc, VALUE *argv, VALUE ary)
 {
-    int h, 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]);
+    }
 
-    h = ary->len;
-    for (i=0; i<ary->len; i++) {
-	h ^= rb_hash(ary->ptr[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);
     }
-    return INT2FIX(h);
+
+    ALLOCV_END(t0);
+
+    return ary_diff;
 }
 
-VALUE
-ary_includes(ary, item)
-    struct RArray *ary;
-    VALUE item;
+
+/*
+ *  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)
 {
-    int i;
-    for (i=0; i<ary->len; i++) {
-	if (rb_equal(ary->ptr[i], item)) {
-	    return TRUE;
+    VALUE hash, ary3, v;
+    st_data_t vv;
+    long i;
+
+    ary2 = to_ary(ary2);
+    ary3 = rb_ary_new();
+    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;
     }
-    return FALSE;
+
+    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
-ary_diff(ary1, ary2)
-    struct RArray *ary1, *ary2;
+rb_ary_intersection_multi(int argc, VALUE *argv, VALUE ary)
 {
-    VALUE ary3;
+    VALUE result = rb_ary_dup(ary);
     int i;
 
-    Check_Type(ary2, T_ARRAY);
-    ary3 = ary_new();
-    for (i=0; i<ary1->len; i++) {
-	if (ary_includes(ary2, ary1->ptr[i])) continue;
-	if (ary_includes(ary3, ary1->ptr[i])) continue;
-	ary_push(ary3, ary1->ptr[i]);
+    for (i = 0; i < argc; i++) {
+        result = rb_ary_and(result, argv[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);
+        }
+    }
+}
+
+/*
+ *  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
-ary_and(ary1, ary2)
-    struct RArray *ary1, *ary2;
+rb_ary_union_multi(int argc, VALUE *argv, VALUE ary)
 {
-    VALUE ary3;
     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)
+{
+    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(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;
+}
 
-    Check_Type(ary2, T_ARRAY);
-    ary3 = ary_new();
-    for (i=0; i<ary1->len; i++) {
-	if (ary_includes(ary2, ary1->ptr[i])
-	    && !ary_includes(ary3, ary1->ptr[i])) {
-	    ary_push(ary3, ary1->ptr[i]);
+/*
+ *  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;
+	   }
 	}
     }
-    return ary3;
+    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_or(ary1, ary2)
-    struct RArray *ary1, *ary2;
+ary_min_generic(VALUE ary, long i, VALUE vmin)
 {
-    VALUE ary3;
-    int i;
+    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;
+}
 
-    if (TYPE(ary2) != T_ARRAY) {
-	if (ary_includes(ary1, ary2)) return (VALUE)ary1;
-	else return ary_plus(ary1, ary2);
+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);
+        }
     }
 
-    ary3 = ary_new();
-    for (i=0; i<ary1->len; i++) {
-	if (!ary_includes(ary3, ary1->ptr[i]))
-		ary_push(ary3, ary1->ptr[i]);
+    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);
+        }
     }
-    for (i=0; i<ary2->len; i++) {
-	if (!ary_includes(ary3, ary2->ptr[i]))
-		ary_push(ary3, ary2->ptr[i]);
+
+    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 ary3;
+
+    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(VALUE ary)
+{
+    VALUE hash, uniq;
+
+    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
-ary_compact_bang(ary)
-    struct RArray *ary;
+rb_ary_compact_bang(VALUE ary)
 {
     VALUE *p, *t, *end;
+    long n;
+
+    rb_ary_modify(ary);
+    p = t = (VALUE *)RARRAY_CONST_PTR_TRANSIENT(ary); /* WB: no new reference */
+    end = p + RARRAY_LEN(ary);
 
-    ary_modify(ary);
-    p = t = ary->ptr;
-    end = p + ary->len;
     while (t < end) {
 	if (NIL_P(*t)) t++;
 	else *p++ = *t++;
     }
-    ary->len = ary->capa = (p - ary->ptr);
-    REALLOC_N(ary->ptr, VALUE, ary->len);
+    n = p - RARRAY_CONST_PTR_TRANSIENT(ary);
+    if (RARRAY_LEN(ary) == n) {
+	return Qnil;
+    }
+    ary_resize_smaller(ary, n);
 
-    return (VALUE)ary;
+    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
-ary_compact(ary)
-    struct RArray *ary;
+rb_ary_compact(VALUE ary)
 {
-    return ary_compact_bang(ary_clone(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)
+{
+    long i, n = 0;
+
+    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
-ary_nitems(ary)
-    struct RArray *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 = ary->ptr;
-    pend = p + 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;
 }
 
-extern VALUE mEnumerable;
+/*
+ *  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
+ */
 
-void
-Init_Array()
-{
-    cArray  = rb_define_class("Array", cObject);
-    rb_include_module(cArray, mEnumerable);
-
-    rb_define_singleton_method(cArray, "new", ary_s_new, -1);
-    rb_define_singleton_method(cArray, "[]", ary_s_create, -1);
-    rb_define_method(cArray, "to_s", ary_to_s, 0);
-    rb_define_method(cArray, "inspect", ary_inspect, 0);
-    rb_define_method(cArray, "to_a", ary_to_a, 0);
-
-    rb_define_method(cArray, "freeze",  ary_freeze, 0);
-    rb_define_method(cArray, "frozen?",  ary_frozen_p, 0);
-
-    rb_define_method(cArray, "==", ary_equal, 1);
-    rb_define_method(cArray, "eql?", ary_eql, 1);
-    rb_define_method(cArray, "hash", ary_hash, 0);
-
-    rb_define_method(cArray, "[]", ary_aref, -1);
-    rb_define_method(cArray, "[]=", ary_aset, -1);
-    rb_define_method(cArray, "concat", ary_concat, 1);
-    rb_define_method(cArray, "<<", ary_push, 1);
-    rb_define_method(cArray, "push", ary_push_method, -1);
-    rb_define_method(cArray, "pop", ary_pop, 0);
-    rb_define_method(cArray, "shift", ary_shift, 0);
-    rb_define_method(cArray, "unshift", ary_unshift, 1);
-    rb_define_method(cArray, "each", ary_each, 0);
-    rb_define_method(cArray, "each_index", ary_each_index, 0);
-    rb_define_method(cArray, "reverse_each", ary_reverse_each, 0);
-    rb_define_method(cArray, "length", ary_length, 0);
-    rb_define_alias(cArray,  "size", "length");
-    rb_define_method(cArray, "empty?", ary_empty_p, 0);
-    rb_define_method(cArray, "index", ary_index, 1);
-    rb_define_method(cArray, "indexes", ary_indexes, -2);
-    rb_define_method(cArray, "clone", ary_clone, 0);
-    rb_define_method(cArray, "join", ary_join_method, -1);
-    rb_define_method(cArray, "reverse", ary_reverse_method, 0);
-    rb_define_method(cArray, "reverse!", ary_reverse, 0);
-    rb_define_method(cArray, "sort", ary_sort, 0);
-    rb_define_method(cArray, "sort!", ary_sort_bang, 0);
-    rb_define_method(cArray, "delete", ary_delete, 1);
-    rb_define_method(cArray, "delete_at", ary_delete_at, 1);
-    rb_define_method(cArray, "delete_if", ary_delete_if, 0);
-#if 0
-    rb_define_method(cArray, "replace", ary_replace, 0);
-#endif
-    rb_define_method(cArray, "clear", ary_clear, 0);
-    rb_define_method(cArray, "fill", ary_fill, -1);
-    rb_define_method(cArray, "include?", ary_includes, 1);
+static VALUE
+rb_ary_flatten_bang(int argc, VALUE *argv, VALUE ary)
+{
+    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);
+    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;
+	}
+    }
+}
+
+/*
+ * 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_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)
+{
+    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);
+
+    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;
+}
 
-    rb_define_method(cArray, "assoc", ary_assoc, 1);
-    rb_define_method(cArray, "rassoc", ary_rassoc, 1);
+/*
+ *  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
+ */
 
-    rb_define_method(cArray, "+", ary_plus, 1);
-    rb_define_method(cArray, "*", ary_times, 1);
+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);
+}
 
-    rb_define_method(cArray, "-", ary_diff, 1);
-    rb_define_method(cArray, "&", ary_and, 1);
-    rb_define_method(cArray, "|", ary_or, 1);
+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#+.
+ */
 
-    rb_define_method(cArray, "compact", ary_compact, 0);
-    rb_define_method(cArray, "compact!", ary_compact_bang, 0);
-    rb_define_method(cArray, "nitems", ary_nitems, 0);
+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);
+    }
 
-    cmp = rb_intern("<=>");
+    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(void)
+{
+    rb_cArray  = rb_define_class("Array", rb_cObject);
+    rb_include_module(rb_cArray, rb_mEnumerable);
+
+    rb_define_alloc_func(rb_cArray, empty_ary_alloc);
+    rb_define_singleton_method(rb_cArray, "[]", rb_ary_s_create, -1);
+    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_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_aref, -1);
+    rb_define_method(rb_cArray, "[]=", rb_ary_aset, -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_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, "empty?", rb_ary_empty_p, 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_m, 1);
+    rb_define_method(rb_cArray, "delete_if", rb_ary_delete_if, 0);
+    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);
+
+    rb_define_method(rb_cArray, "+", rb_ary_plus, 1);
+    rb_define_method(rb_cArray, "*", rb_ary_times, 1);
+
+    rb_define_method(rb_cArray, "-", rb_ary_diff, 1);
+    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, -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/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