9503 files changed, 2117462 insertions, 29729 deletions

diff --git a/.dir-locals.el b/.dir-locals.el
new file mode 100644
index 0000000000..7c32d1f7ee
--- /dev/null
+++ b/.dir-locals.el
@@ -0,0 +1,37 @@
+;; 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")))
+
+ (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..8a418e5d4a
--- /dev/null
+++ b/.document
@@ -0,0 +1,42 @@
+# 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
+
+ast.rb
+gc.rb
+io.rb
+pack.rb
+trace_point.rb
+warning.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
+
+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..0d44622691
--- /dev/null
+++ b/.gdbinit
@@ -0,0 +1,1346 @@
+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*)($arg0))->as.heap.aux.shared
+	printf " "
+      else
+	printf "(ownership) capa=%ld ", ((struct RArray*)($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
+    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
+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-trunk/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/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/cygwin.yml b/.github/workflows/cygwin.yml
new file mode 100644
index 0000000000..515b47e141
--- /dev/null
+++ b/.github/workflows/cygwin.yml
@@ -0,0 +1,79 @@
+name: Cygwin
+on:
+  push:
+    branches:
+      - master
+  pull_request:
+    branches:
+      - '*'
+jobs:
+  make:
+    strategy:
+      matrix:
+        test_task: [test]
+        os: [windows-2019]
+        vs: [2019]
+      fail-fast: false
+    runs-on: ${{ matrix.os }}
+    if: "!contains(github.event.head_commit.message, '[ci skip]')"
+    steps:
+      - uses: actions/cache@v1
+        with:
+          path: C:\Users\runneradmin\AppData\Local\Temp\chocolatey
+          key: ${{ runner.os }}-cygwin-chocolatey-${{ matrix.os }}-${{ github.sha }}
+          restore-keys: |
+            ${{ runner.os }}-cygwin-chocolatey-${{ matrix.os }}-
+            ${{ runner.os }}-cygwin-chocolatey-
+      - name: Install cygwin base packages with chocolatey
+        run: |
+          choco install --no-progress cygwin
+      - uses: actions/cache@v1
+        with:
+          path: C:\tools\cygwin\package
+          key: ${{ runner.os }}-cygwin-package-${{ matrix.os }}-${{ github.sha }}
+          restore-keys: |
+            ${{ runner.os }}-cygwin-package-${{ matrix.os }}-
+            ${{ runner.os }}-cygwin-package-
+      - name: Install cygwin additional packages
+        run: |
+          C:\tools\cygwin\cygwinsetup.exe -qgnNdO -R C:/tools/cygwin -l C:/tools/cygwin/package -s http://mirrors.kernel.org/sourceware/cygwin/ -P autoconf,bison,gcc-core,git,libffi-devel,libgdbm-devel,libgmp-devel,libreadline-devel,libssl-devel,make,patch,ruby,zlib-devel
+        shell: cmd
+      - name: Set ENV
+        run: |
+          echo '::set-env name=PATH::C:\tools\cygwin\bin;C:\tools\cygwin\usr\bin'
+      # Not using official actions/checkout because it's unstable and sometimes doesn't work for a fork.
+      - name: Checkout ruby/ruby
+        run: |
+          git clone --single-branch --shallow-since=yesterday https://github.com/ruby/ruby src
+          git -C src reset --hard ${{ github.sha }}
+        if: github.event_name == 'push'
+        shell: cmd
+      - name: Checkout a pull request
+        run: |
+          git clone --single-branch --shallow-since=yesterday --branch=${{ github.event.pull_request.head.ref }} https://github.com/${{ github.event.pull_request.head.repo.full_name }} src
+          git -C src reset --hard ${{ github.event.pull_request.head.sha }}
+        if: github.event_name == 'pull_request'
+        shell: cmd
+      - run: ./src/tool/actions-commit-info.sh
+        shell: bash
+        id: commit_info
+      - name: Autoconf
+        run: |
+          cd src
+          bash /usr/bin/autoconf
+        shell: cmd
+      - name: Configure
+        run: |
+          md build
+          cd build
+          bash ../src/configure
+        shell: cmd
+      - name: make
+        run: |
+          make -C build
+        shell: cmd
+      # TODO: Fix test fail on cygwin environment on GitHub Actions
+      # - name: make btest
+      #   run: |
+      #     make -C build btest
+      #   shell: cmd
diff --git a/.github/workflows/macos.yml b/.github/workflows/macos.yml
new file mode 100644
index 0000000000..724081d9dc
--- /dev/null
+++ b/.github/workflows/macos.yml
@@ -0,0 +1,81 @@
+name: macOS
+on:
+  push:
+    branches:
+      - master
+  pull_request:
+    branches:
+      - '*'
+jobs:
+  make:
+    runs-on: macos-latest
+    strategy:
+      matrix:
+        test_task: [ "check", "test-bundler", "test-bundled-gems" ]
+      fail-fast: false
+    if: "!contains(github.event.head_commit.message, '[ci skip]')"
+    steps:
+      - name: Disable Firewall
+        run: |
+          sudo /usr/libexec/ApplicationFirewall/socketfilterfw --setglobalstate off
+          sudo /usr/libexec/ApplicationFirewall/socketfilterfw --getglobalstate
+      # Not using official actions/checkout because it's unstable and sometimes doesn't work for a fork.
+      - name: Checkout ruby/ruby
+        run: |
+          git clone --single-branch --shallow-since=yesterday https://github.com/ruby/ruby src
+          git -C src reset --hard "$GITHUB_SHA"
+        if: github.event_name == 'push'
+      - name: Checkout a pull request
+        run: |
+          git clone --single-branch --shallow-since=yesterday "--branch=$GITHUB_BRANCH" "https://github.com/${GITHUB_REPO}" src
+          git -C src reset --hard "$GITHUB_REV"
+        env:
+          GITHUB_REV: ${{ github.event.pull_request.head.sha }}
+          GITHUB_BRANCH: ${{ github.event.pull_request.head.ref }}
+          GITHUB_REPO: ${{ github.event.pull_request.head.repo.full_name }}
+        if: github.event_name == 'pull_request'
+      - run: ./src/tool/actions-commit-info.sh
+        id: commit_info
+      - name: Install libraries
+        run: |
+          export WAITS='5 60'
+          cd src
+          tool/travis_retry.sh brew update
+          tool/travis_retry.sh brew install gdbm gmp libffi openssl@1.1 zlib autoconf automake libtool readline
+      - name: Set ENV
+        run: |
+          echo '::set-env name=JOBS::'-j$((1 + $(sysctl -n hw.activecpu)))
+      - name: Autoconf
+        run: |
+          cd src
+          autoconf
+      - name: Configure
+        run: |
+          mkdir build
+          cd build
+          ../src/configure -C --disable-install-doc --with-openssl-dir=$(brew --prefix openssl@1.1) --with-readline-dir=$(brew --prefix readline)
+      - name: Make
+        run: make -C build $JOBS
+      - name: Extract gems
+        run: make -C build update-gems extract-gems
+        if: matrix.test_task == 'check'
+      - name: Tests
+        run: make -C build $JOBS -s ${{ matrix.test_task }}
+        env:
+          RUBY_TESTOPTS: "-q --tty=no"
+      - name: Leaked Globals
+        run: make -C build -s leaked-globals
+      - uses: k0kubun/action-slack@v2.0.0
+        with:
+          payload: |
+            {
+              "attachments": [{
+                "text": "${{ job.status }}: ${{ github.workflow }} / ${{ matrix.test_task }} <https://github.com/${{ github.repository }}/commit/${{ github.sha }}/checks|${{ steps.commit_info.outputs.COMMIT_DATE }} #${{ steps.commit_info.outputs.COMMIT_NUMBER_OF_DAY }}> " +
+                        "(<https://github.com/${{ github.repository }}/commit/${{ github.sha }}|" + "${{ github.sha }}".substring(0, 10) + ">) " +
+                        "of ${{ github.repository }}@" + "${{ github.ref }}".split('/').reverse()[0] + " by ${{ github.event.head_commit.committer.name }}",
+                "color": "danger"
+              }]
+            }
+        env:
+          SLACK_WEBHOOK_URL: ${{ secrets.SLACK_WEBHOOK_URL }}
+        if: failure() && github.event_name == 'push'
diff --git a/.github/workflows/mjit.yml b/.github/workflows/mjit.yml
new file mode 100644
index 0000000000..d23c136619
--- /dev/null
+++ b/.github/workflows/mjit.yml
@@ -0,0 +1,79 @@
+name: MJIT
+on:
+  push:
+    branches:
+      - master
+  pull_request:
+    branches:
+      - '*'
+jobs:
+  test:
+    strategy:
+      matrix:
+        jit_opts: [ "--jit", "--jit-wait" ]
+      fail-fast: false
+    runs-on: ubuntu-latest
+    if: "!contains(github.event.head_commit.message, '[ci skip]')"
+    steps:
+      - name: Install libraries
+        run: |
+          set -x
+          sudo apt-get update -q || :
+          sudo apt-get install --no-install-recommends -q -y build-essential libssl-dev libyaml-dev libreadline6-dev zlib1g-dev libncurses5-dev libffi-dev libgdbm-dev bison autoconf ruby
+      # Not using official actions/checkout because it's unstable and sometimes doesn't work for a fork.
+      - name: Checkout ruby/ruby
+        run: |
+          git clone --single-branch --shallow-since=yesterday https://github.com/ruby/ruby src
+          git -C src reset --hard "$GITHUB_SHA"
+        if: github.event_name == 'push'
+      - name: Checkout a pull request
+        run: |
+          git clone --single-branch --shallow-since=yesterday "--branch=$GITHUB_BRANCH" "https://github.com/${GITHUB_REPO}" src
+          git -C src reset --hard "$GITHUB_REV"
+        env:
+          GITHUB_REV: ${{ github.event.pull_request.head.sha }}
+          GITHUB_BRANCH: ${{ github.event.pull_request.head.ref }}
+          GITHUB_REPO: ${{ github.event.pull_request.head.repo.full_name }}
+        if: github.event_name == 'pull_request'
+      - run: ./src/tool/actions-commit-info.sh
+        id: commit_info
+      - name: Fixed world writable dirs
+        run: |
+          chmod go-w $HOME
+          sudo chmod -R go-w /usr/share
+      - name: Set ENV
+        run: |
+          echo '::set-env name=JOBS::'-j$((1 + $(nproc --all)))
+      - name: Autoconf
+        run: cd src && exec autoconf
+      - name: configure
+        run: |
+          mkdir build
+          cd build
+          ../src/configure -C --disable-install-doc
+      - name: make all
+        run: make -C build $JOBS
+      - name: make install
+        run: sudo make -C build $JOBS install
+      - name: make test
+        run: "make -C build $JOBS -s test TESTOPTS='-q --tty=no' RUN_OPTS='--disable-gems --jit-warnings ${{ matrix.jit_opts }}'"
+      - name: make test-all
+        run: "make -C build $JOBS -s test-all TESTOPTS='-q --tty=no' RUN_OPTS='--disable-gems --jit-warnings ${{ matrix.jit_opts }}'"
+      - name: make test-spec
+        run: "make -C build $JOBS -s test-spec RUN_OPTS='--disable-gems --jit-warnings ${{ matrix.jit_opts }}'"
+      - name: Leaked Globals
+        run: make -C build -s leaked-globals
+      - uses: k0kubun/action-slack@v2.0.0
+        with:
+          payload: |
+            {
+              "attachments": [{
+                "text": "${{ job.status }}: ${{ github.workflow }} / ${{ matrix.jit_opts }} <https://github.com/${{ github.repository }}/commit/${{ github.sha }}/checks|${{ steps.commit_info.outputs.COMMIT_DATE }} #${{ steps.commit_info.outputs.COMMIT_NUMBER_OF_DAY }}> " +
+                        "(<https://github.com/${{ github.repository }}/commit/${{ github.sha }}|" + "${{ github.sha }}".substring(0, 10) + ">) " +
+                        "of ${{ github.repository }}@" + "${{ github.ref }}".split('/').reverse()[0] + " by ${{ github.event.head_commit.committer.name }}",
+                "color": "danger"
+              }]
+            }
+        env:
+          SLACK_WEBHOOK_URL: ${{ secrets.SLACK_WEBHOOK_URL }}
+        if: failure() && github.event_name == 'push'
diff --git a/.github/workflows/ubuntu.yml b/.github/workflows/ubuntu.yml
new file mode 100644
index 0000000000..885f078f07
--- /dev/null
+++ b/.github/workflows/ubuntu.yml
@@ -0,0 +1,115 @@
+name: Ubuntu
+on:
+  push:
+    branches:
+      - master
+  pull_request:
+    branches:
+      - '*'
+jobs:
+  make:
+    strategy:
+      matrix:
+        test_task: [ "check", "test-bundler", "test-bundled-gems" ]
+        os: [ubuntu-latest, ubuntu-16.04]
+        exclude:
+          - test_task: test-bundler
+            os: ubuntu-16.04
+          - test_task: test-bundled-gems
+            os: ubuntu-16.04
+      fail-fast: false
+    runs-on: ${{ matrix.os }}
+    if: "!contains(github.event.head_commit.message, '[ci skip]')"
+    steps:
+      - run: env | sort
+      - name: Dump GitHub context
+        env:
+          GITHUB_CONTEXT: ${{ toJson(github) }}
+        run: echo "$GITHUB_CONTEXT"
+      - name: Dump job context
+        env:
+          JOB_CONTEXT: ${{ toJson(job) }}
+        run: echo "$JOB_CONTEXT"
+      - name: Dump steps context
+        env:
+          STEPS_CONTEXT: ${{ toJson(steps) }}
+        run: echo "$STEPS_CONTEXT"
+      - name: Dump runner context
+        env:
+          RUNNER_CONTEXT: ${{ toJson(runner) }}
+        run: echo "$RUNNER_CONTEXT"
+      - name: Dump strategy context
+        env:
+          STRATEGY_CONTEXT: ${{ toJson(strategy) }}
+        run: echo "$STRATEGY_CONTEXT"
+      - name: Dump matrix context
+        env:
+          MATRIX_CONTEXT: ${{ toJson(matrix) }}
+        run: echo "$MATRIX_CONTEXT"
+
+      - 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
+      # Not using official actions/checkout because it's unstable and sometimes doesn't work for a fork.
+      - name: Checkout ruby/ruby
+        run: |
+          git clone --single-branch --shallow-since=yesterday https://github.com/ruby/ruby src
+          git -C src reset --hard "$GITHUB_SHA"
+        if: github.event_name == 'push'
+      - name: Checkout a pull request
+        run: |
+          git clone --single-branch --shallow-since=yesterday "--branch=$GITHUB_BRANCH" "https://github.com/${GITHUB_REPO}" src
+          git -C src reset --hard "$GITHUB_REV"
+        env:
+          GITHUB_REV: ${{ github.event.pull_request.head.sha }}
+          GITHUB_BRANCH: ${{ github.event.pull_request.head.ref }}
+          GITHUB_REPO: ${{ github.event.pull_request.head.repo.full_name }}
+        if: github.event_name == 'pull_request'
+      - run: ./src/tool/actions-commit-info.sh
+        id: commit_info
+      - name: Fixed world writable dirs
+        run: |
+          chmod go-w $HOME
+          sudo chmod -R go-w /usr/share
+      - name: Set ENV
+        run: |
+          echo '::set-env name=JOBS::'-j$((1 + $(nproc --all)))
+      - name: Autoconf
+        run: cd src && exec autoconf
+      - name: configure
+        run: |
+          mkdir build
+          cd build
+          ../src/configure -C --disable-install-doc
+      - name: Make
+        run: make -C build $JOBS
+      - name: Extract gems
+        run: make -C build update-gems extract-gems
+        if: matrix.test_task == 'check'
+      - name: Create dummy files in build dir
+        run: |
+          cd build
+          ./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'
+      - name: Tests
+        run: make -C build $JOBS -s ${{ matrix.test_task }}
+        env:
+          RUBY_TESTOPTS: "-q --tty=no"
+      - name: Leaked Globals
+        run: make -C build -s leaked-globals
+      - uses: k0kubun/action-slack@v2.0.0
+        with:
+          payload: |
+            {
+              "attachments": [{
+                "text": "${{ job.status }}: ${{ matrix.os }} / ${{ matrix.test_task }} <https://github.com/${{ github.repository }}/commit/${{ github.sha }}/checks|${{ steps.commit_info.outputs.COMMIT_DATE }} #${{ steps.commit_info.outputs.COMMIT_NUMBER_OF_DAY }}> " +
+                        "(<https://github.com/${{ github.repository }}/commit/${{ github.sha }}|" + "${{ github.sha }}".substring(0, 10) + ">) " +
+                        "of ${{ github.repository }}@" + "${{ github.ref }}".split('/').reverse()[0] + " by ${{ github.event.head_commit.committer.name }}",
+                "color": "danger"
+              }]
+            }
+        env:
+          SLACK_WEBHOOK_URL: ${{ secrets.SLACK_WEBHOOK_URL }}
+        if: failure() && github.event_name == 'push'
diff --git a/.github/workflows/windows.yml b/.github/workflows/windows.yml
new file mode 100644
index 0000000000..09e588784c
--- /dev/null
+++ b/.github/workflows/windows.yml
@@ -0,0 +1,90 @@
+name: Windows
+on:
+  push:
+    branches:
+      - master
+  pull_request:
+    branches:
+      - '*'
+jobs:
+  make:
+    strategy:
+      matrix:
+        test_task: [test]
+        os: [windows-2019]
+        vs: [2019]
+      fail-fast: false
+    runs-on: ${{ matrix.os }}
+    if: "!contains(github.event.head_commit.message, '[ci skip]')"
+    steps:
+      - uses: actions/cache@v1
+        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@v1
+        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 winflexbison3
+      # Not using official actions/checkout because it's unstable and sometimes doesn't work for a fork.
+      - name: Checkout ruby/ruby
+        run: |
+          git clone --single-branch --shallow-since=yesterday https://github.com/ruby/ruby src
+          git -C src reset --hard ${{ github.sha }}
+        if: github.event_name == 'push'
+      - name: Checkout a pull request
+        run: |
+          git clone --single-branch --shallow-since=yesterday --branch=${{ github.event.pull_request.head.ref }} https://github.com/${{ github.event.pull_request.head.repo.full_name }} src
+          git -C src reset --hard ${{ github.event.pull_request.head.sha }}
+        if: github.event_name == 'pull_request'
+      - run: ./src/tool/actions-commit-info.sh
+        shell: bash
+        id: commit_info
+      - name: Configure
+        run: |
+          md build
+          cd build
+          call "C:\Program Files (x86)\Microsoft Visual Studio\${{ matrix.vs }}\Enterprise\VC\Auxiliary\Build\vcvars64.bat"
+          ../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"
+        shell: cmd
+      - name: nmake
+        run: |
+          call "C:\Program Files (x86)\Microsoft Visual Studio\${{ matrix.vs }}\Enterprise\VC\Auxiliary\Build\vcvars64.bat"
+          set YACC=win_bison
+          cd build
+          echo on
+          nmake up
+          nmake extract-gems
+          nmake
+        shell: cmd
+      - name: nmake test
+        run: |
+          call "C:\Program Files (x86)\Microsoft Visual Studio\${{ matrix.vs }}\Enterprise\VC\Auxiliary\Build\vcvars64.bat"
+          cd build
+          nmake ${{ matrix.test_task }}
+        shell: cmd
+      - uses: k0kubun/action-slack@v2.0.0
+        with:
+          payload: |
+            {
+              "attachments": [{
+                "text": "${{ job.status }}: ${{ matrix.os }} / ${{ matrix.test_task }} <https://github.com/${{ github.repository }}/commit/${{ github.sha }}/checks|${{ steps.commit_info.outputs.COMMIT_DATE }} #${{ steps.commit_info.outputs.COMMIT_NUMBER_OF_DAY }}> " +
+                        "(<https://github.com/${{ github.repository }}/commit/${{ github.sha }}|" + "${{ github.sha }}".substring(0, 10) + ">) " +
+                        "of ${{ github.repository }}@" + "${{ github.ref }}".split('/').reverse()[0] + " by ${{ github.event.head_commit.committer.name }}",
+                "color": "danger"
+              }]
+            }
+        env:
+          SLACK_WEBHOOK_URL: ${{ secrets.SLACK_WEBHOOK_URL }}
+        if: failure() && github.event_name == 'push'
diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000000..487af950f3
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,225 @@
+*-*-*.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
+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
+/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
+/riscos
+/rubicon
+/ruby
+/ruby-runner
+/ruby-runner.h
+/ruby-man.rd.gz
+/run.gdb
+/sizes.c
+/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/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..71945e349e
--- /dev/null
+++ b/.travis.yml
@@ -0,0 +1,550 @@
+# -*- 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=."
+    # 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:
+
+  - &cron-only
+    if: (type = cron) AND (branch = master) AND (fork = false)
+
+  - &make-test-only
+    script:
+      - $SETARCH make -s test TESTOPTS="${TESTOPTS=$JOBS -q --tty=no}"
+
+  - &gcc-8
+    compiler: gcc-8
+    # # Not using addon to control retries
+    # addons:
+    #   apt:
+    #     sources:
+    #       - ubuntu-toolchain-r-test
+    before_install:
+      - tool/travis_retry.sh sudo -E apt-add-repository -y "ppa:ubuntu-toolchain-r/test"
+      - tool/travis_retry.sh sudo bash -c "rm -rf '${TRAVIS_ROOT}/var/lib/apt/lists/'* && exec apt-get update -yq"
+      - |-
+        ${BEFORE_INSTALL}
+        tool/travis_retry.sh sudo -E apt-get $travis_apt_get_options install \
+          ccache \
+          gcc-8 \
+          g++-8 \
+          libffi-dev \
+          libgdbm-dev \
+          libgmp-dev \
+          libjemalloc-dev \
+          libncurses5-dev \
+          libncursesw5-dev \
+          libreadline6-dev \
+          libssl-dev \
+          libyaml-dev \
+          openssl \
+          valgrind \
+          zlib1g-dev
+
+  - &clang-8
+    compiler: clang-8
+    addons:
+      apt:
+        # Not doing this manually unlike other sources, because it has been stable.
+        sources:
+          - llvm-toolchain-xenial-8
+        config:
+          retries: true
+    before_install:
+      - tool/travis_retry.sh sudo bash -c "rm -rf '${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 \
+          libgmp-dev \
+          libjemalloc-dev \
+          libncurses5-dev \
+          libncursesw5-dev \
+          libreadline6-dev \
+          libssl-dev \
+          libyaml-dev \
+          openssl \
+          valgrind \
+          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
+    
+  - &jemalloc
+    name: --with-jemalloc
+    <<: *gcc-8
+    <<: *cron-only
+    env:
+      - CONFIG_FLAG='--with-gmp --with-jemalloc --with-valgrind'
+
+  - &assertions
+    name: RUBY_DEBUG=1
+    <<: *gcc-8
+    #<<: *cron-only
+    <<: *make-test-only
+    env:
+      - GEMS_FOR_TEST=
+      - cppflags='-DRUBY_DEBUG -DVM_CHECK_MODE=1 -DTRANSIENT_HEAP_CHECK_MODE -DRGENGC_CHECK_MODE -DENC_DEBUG'
+
+  - &VM_CHECK_MODE
+    name: VM_CHECK_MODE=3
+    <<: *gcc-8
+    <<: *cron-only
+    <<: *make-test-only
+    env:
+      - GEMS_FOR_TEST=
+      - cppflags=-DVM_CHECK_MODE=0x0003
+
+  - &SUPPORT_JOKE
+    name: SUPPORT_JOKE
+    <<: *gcc-8
+    <<: *cron-only
+    <<: *make-test-only
+    env:
+      - BEFORE_INSTALL="sed vm_opts.h -e 's/OPT_SUPPORT_JOKE *0/OPT_SUPPORT_JOKE 1/' -i"
+
+  - &CPDEBUG
+    name: CPDEBUG
+    <<: *gcc-8
+    <<: *cron-only
+    <<: *make-test-only
+    env:
+      - cppflags=-DCPDEBUG
+
+  - &WITH_COROUTINE_UCONTEXT
+    name: COROUTINE=ucontext
+    <<: *gcc-8
+    <<: *cron-only
+    env:
+      - CONFIG_FLAG='--with-coroutine=ucontext'
+
+  - &WITH_COROUTINE_COPY
+    name: COROUTINE=copy
+    <<: *gcc-8
+    <<: *cron-only
+    env:
+      - CONFIG_FLAG='--with-coroutine=copy'
+
+  - &TOKEN_THREADED_CODE
+    name: TOKEN_THREADED_CODE
+    <<: *gcc-8
+    <<: *cron-only
+    <<: *make-test-only
+    env:
+      - GEMS_FOR_TEST=
+      - cppflags=-DOPT_THREADED_CODE=1
+
+  - &CALL_THREADED_CODE
+    name: CALL_THREADED_CODE
+    <<: *gcc-8
+    <<: *cron-only
+    <<: *make-test-only
+    env:
+      - GEMS_FOR_TEST=
+      - cppflags=-DOPT_THREADED_CODE=2
+
+  - &NO_THREADED_CODE
+    name: NO_THREADED_CODE
+    <<: *gcc-8
+    <<: *cron-only
+    <<: *make-test-only
+    env:
+      - GEMS_FOR_TEST=
+      - cppflags=-DOPT_THREADED_CODE=3
+
+  - &ASAN
+    name: -fsanitize=address
+    <<: *clang-8
+    #<<: *cron-only
+    <<: *make-test-only
+    env:
+      - GEMS_FOR_TEST=
+      - ASAN_OPTIONS=detect_leaks=0
+      - cflags='-U_FORTIFY_SOURCE -march=native -fsanitize=address -fno-omit-frame-pointer -fPIC'
+      - debugflags=-ggdb3
+      - optflags=-O1
+      - LD=clang-8
+      - LDFLAGS='-fsanitize=address -fPIC'
+      - CONFIG_FLAG='--with-out-ext=openssl --without-gmp --without-jemalloc --without-valgrind'
+
+  - &MSAN
+    name: -fsanitize=memory
+    <<: *clang-8
+    #<<: *cron-only
+    <<: *make-test-only
+    env:
+      - GEMS_FOR_TEST=
+      - cflags='-U_FORTIFY_SOURCE -fsanitize=memory -fsanitize-memory-track-origins=2 -fno-omit-frame-pointer -fPIC'
+      - optflags=-O1
+      - LD=clang-8
+      - LDFLAGS='-fsanitize=memory -fPIC'
+      - CONFIG_FLAG='--with-out-ext=openssl --without-gmp --without-jemalloc --without-valgrind'
+
+  - &UBSAN
+    name: -fsanitize=undefined
+    <<: *clang-8
+    #<<: *cron-only
+    <<: *make-test-only
+    env:
+      - GEMS_FOR_TEST=
+      - cflags='-U_FORTIFY_SOURCE -fsanitize=undefined,integer,nullability -fno-sanitize=implicit-integer-sign-change,unsigned-integer-overflow'
+      - cppflags=-DUNALIGNED_WORD_ACCESS=0
+      - debugflags=-ggdb3
+      - optflags='-O1 -march=native'
+      - LD=clang-8
+      - LDFLAGS='-fsanitize=undefined,integer,nullability -fno-sanitize=implicit-integer-sign-change,unsigned-integer-overflow'
+
+  - &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
+
+  - &pedanticism
+    name: -std=c99 -pedantic
+    compiler: clang
+    <<: *make-test-only
+    env:
+      - GEMS_FOR_TEST=
+      - GCC_FLAGS='-std=c99 -Werror=pedantic -pedantic-errors'
+      - CONFIG_FLAG=
+      - JOBS=
+      - >-
+        warnflags='
+        -Wall
+        -Wextra
+        -Werror=deprecated-declarations
+        -Werror=division-by-zero
+        -Werror=extra-tokens
+        -Werror=implicit-function-declaration
+        -Werror=implicit-int
+        -Werror=pointer-arith
+        -Werror=shorten-64-to-32
+        -Werror=write-strings
+        -Wmissing-noreturn
+        -Wno-constant-logical-operand
+        -Wno-missing-field-initializers
+        -Wno-overlength-strings
+        -Wno-parentheses-equality
+        -Wno-self-assign
+        -Wno-tautological-compare
+        -Wno-unused-local-typedef
+        -Wno-unused-parameter
+        -Wunused-variable'
+      - LDFLAGS=-Wno-unused-command-line-argument
+
+  - &rubyspec
+    name: Check ruby/spec version guards on Ruby 2.4
+    language: ruby
+    rvm: 2.4.6
+    before_install:
+    install:
+    before_script: chmod -R u+w spec/ruby
+    # -j randomly hangs.
+    script: ruby -C spec/ruby ../mspec/bin/mspec .
+    after_failure:
+      - echo "ruby/spec failed on Ruby 2.4. This is likely because of a missing ruby_version_is guard, please add it. See spec/README.md."
+
+  - &baseruby
+    name: "BASERUBY: Ruby 2.2"
+    <<: *gcc-8
+    <<: *make-test-only
+    language: ruby
+    rvm: 2.2
+
+  - &dependency
+    name: Check dependencies in makefiles
+    language: ruby
+    before_install:
+    install:
+    before_script:
+      - |-
+        ruby -e 'new = []
+          Dir.glob("ext/**/extconf.rb") {|ex|
+            unless File.exist?(dep = File.dirname(ex)+"/depend")
+              puts "Adding "+dep
+              File.copy_stream("template/depend.tmpl", dep)
+              new << dep
+            end
+          }
+          exec("git", "add", *new) unless new.empty?'
+      - git diff --cached
+      - "> 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
+      - $SETARCH ./configure -C --disable-install-doc --prefix=$RUBY_PREFIX --disable-rubygems 'optflags=-O0' 'debugflags=-save-temps=obj -g'
+      - ruby tool/update-deps --fix
+    script:
+      - git diff --no-ext-diff --ignore-submodules --exit-code
+    after_failure:
+      - echo "Dependencies need to update"
+    env:
+      - CONFIG_FLAG=
+
+matrix:
+  include:
+    # Build every commit:
+    - <<: *x86_64-linux
+    - <<: *arm64-linux
+    - <<: *i686-linux
+    - <<: *arm32-linux
+    - <<: *s390x-linux
+    - <<: *pedanticism
+    - <<: *assertions
+    - <<: *baseruby
+    - <<: *rubyspec
+    - <<: *dependency
+    # Build every commit (Allowed Failures):
+    - <<: *ASAN
+    - <<: *MSAN
+    - <<: *UBSAN
+    # Cron only:
+    - <<: *jemalloc
+    - <<: *VM_CHECK_MODE
+    - <<: *SUPPORT_JOKE
+    - <<: *CPDEBUG
+    - <<: *WITH_COROUTINE_UCONTEXT
+    - <<: *WITH_COROUTINE_COPY
+    - <<: *TOKEN_THREADED_CODE
+    - <<: *CALL_THREADED_CODE
+    - <<: *NO_THREADED_CODE
+  allow_failures:
+    - name: s390x-linux
+    - name: -fsanitize=address
+    - name: -fsanitize=memory
+    - name: -fsanitize=undefined
+  fast_finish: true
+
+before_script:
+  - date # Debugging "Permission defined" failure on darwin like https://travis-ci.org/ruby/ruby/jobs/508683759
+  - dpkg --print-architecture
+  - dpkg --print-foreign-architectures
+  - setarch --list
+  - echo JOBS=${JOBS} SETARCH=${SETARCH}
+  - $SETARCH uname -a
+  - $SETARCH uname -r
+  - rm -fr .ext autom4te.cache
+  - echo $TERM
+  - |-
+    [ -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
+  - date; make touch-unicode-files
+  - date; make -s $JOBS $UPDATE_UNICODE up
+  - date; make -s $JOBS srcs
+  - rm -f config.status Makefile rbconfig.rb .rbconfig.time
+  - |-
+    if [ -d ~/config_2nd ]; then
+      cp -pr ~/config_2nd build
+    else
+      mkdir build
+    fi
+  - mkdir config_1st config_2nd
+  - chmod -R a-w .
+  - chmod -R u+w build config_1st config_2nd
+  - cd build
+  - ccache --show-stats
+  - |-
+    case "$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 $JOBS
+  - |-
+    date; : # Debugging "Permission defined" failure on darwin like https://travis-ci.org/ruby/ruby/jobs/508683759
+    if ! make install; then
+      if [ "$(uname)" = Darwin ]; then
+        # Debugging "Permission defined" failure on darwin like https://travis-ci.org/ruby/ruby/jobs/508683759
+        set -x
+        date
+        ./miniruby -e 'ARGV.map{|path|[path,File.stat(path)]}.sort_by{|path,st|st.mtime}.each{|path,st|p mtime:st.mtime.to_f, ctime:st.ctime.to_f, path:path}' .ext/.timestamp/.RUBYCOMMONDIR*time .ext/common/bigdecimal/*.rb ../ext/bigdecimal/lib/bigdecimal/*.rb . .. .ext .ext/common .ext/common/bigdecimal ext/bigdecimal ../ext ../ext/bigdecimal ../ext/bigdecimal/lib ../ext/bigdecimal/lib/bigdecimal
+        make COPY='cp -f' install
+      else
+        exit 1
+      fi
+    fi
+  - ccache --show-stats
+  - |-
+    [ -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
+
+# 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}"
+
+  slack:
+    rooms:
+      - secure: ah7UEHBvncXT7bM5mvYIQAO+tIyV/wl7nXLb7wQD16dO2v8Gragy0mWjB79Q09hrrMGmp6H9bCDpdGS80boIA5EHaHoG4QaP0i9bsSt8U2AMWgZtfyIgQKJ4H2kXkGlrjO+AXTgnIkP7LNjdgAVUUTGQPb26T3QmoN2Splt+fIQ= # ruby:<token>#alerts
+    on_pull_requests: false
+    on_success: change
+    on_failure: always
+
+  email:
+    - ko1c-failure@atdot.net
diff --git a/BSDL b/BSDL
new file mode 100644
index 0000000000..a009caefea
--- /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/C-IF b/C-IF
deleted file mode 100644
index 5c66a20ddc..0000000000
--- a/C-IF
+++ /dev/null
@@ -1,204 +0,0 @@
-.\" C-IF -  -*- Text -*- created at: Tue Oct 12 14:15:00 JST 1993
-
-Ruby-C ¥¤¥ó¥¿¡¼¥Õ¥§¡¼¥¹
-
-·¿
-
- VALUE
-
-   Ruby¥ª¥Ö¥¸¥§¥¯¥È¤òɽ¸½¤¹¤ë·¿. ɬÍפ˱þ¤¸¤Æ¥­¥ã¥¹¥È¤·¤ÆÍѤ¤¤ë. ÁȤß
-   ¹þ¤ß·¿¤òɽ¸½¤¹¤ëC¤Î·¿¤Ïruby.h¤Ëµ­½Ò¤·¤Æ¤¢¤ëR¤Ç»Ï¤Þ¤ë¹½Â¤ÂΤǤ¢¤ë.
-   VALUE·¿¤ò¤³¤ì¤é¤Ë¥­¥ã¥¹¥È¤¹¤ë¤¿¤á¤ËR¤Ç»Ï¤Þ¤ë¹½Â¤ÂÎ̾¤òÁ´¤ÆÂçʸ»ú¤Ë
-   ¤·¤¿Ì¾Á°¤Î¥Þ¥¯¥í¤¬ÍÑ°Õ¤µ¤ì¤Æ¤¤¤ë.
-
-ÊÑ¿ô¡¦Äê¿ô
-
- Qnil
-
-   Äê¿ô: nil¥ª¥Ö¥¸¥§¥¯¥È
-
- Qself
-
-   ÊÑ¿ô: ¸½ºß¤Îself¥ª¥Ö¥¸¥§¥¯¥È¤ÎÃÍ. °ìÈ̤˥᥽¥Ã¥É¤Ë¤Ïself¤ò»Ø¤¹°ú¿ô
-   ¤¬Í¿¤¨¤é¤ì¤ë¤Î¤Ç, ¤³¤ÎÊÑ¿ô¤Ë¥¢¥¯¥»¥¹¤¹¤ëɬÍפϤʤ¤. ¤³¤ÎÊÑ¿ô¤ÎÃͤò
-   Êѹ¹¤¹¤ë»þ¤Ï°Ê¸å¤Îself¤ÎÃͤ½¤Î¤â¤Î¤¬ÊѤï¤Ã¤Æ¤·¤Þ¤¦¤Î¤Ç, ÆÃÊ̤ʻö¾ð
-   ¤¬¤Ê¤¤¸Â¤êÂåÆþ¤·¤Æ¤Ï¤Ê¤é¤Ê¤¤.
-
- TRUE
-
-   Äê¿ô: t¥ª¥Ö¥¸¥§¥¯¥È(¿¿¤Î¥Ç¥Õ¥©¥ë¥ÈÃÍ)
-
- FALSE
-
-   Äê¿ô: nil¥ª¥Ö¥¸¥§¥¯¥È
-
-¥¯¥é¥¹¡¦¥â¥¸¥å¡¼¥ëÄêµÁ
-
- VALUE rb_define_class(char *name, VALUE super)
-
-   super¤Î¥µ¥Ö¥¯¥é¥¹¤È¤·¤Æ¿·¤·¤¤Ruby¥¯¥é¥¹¤òÄêµÁ¤¹¤ë.
-
- VALUE rb_define_module(char *name)
-
-   ¿·¤·¤¤Ruby¥â¥¸¥å¡¼¥ë¤òÄêµÁ¤¹¤ë.
-
- void rb_include_module(VALUE class, VALUE module)
-
-   ¥â¥¸¥å¡¼¥ë¤ò¥¤¥ó¥¯¥ë¡¼¥É¤¹¤ë. class¤¬¤¹¤Ç¤Ëmodule¤ò¥¤¥ó¥¯¥ë¡¼¥É¤·¤Æ
-   ¤¤¤ë»þ¤Ë¤Ï²¿¤â¤·¤Ê¤¤(¿½Å¥¤¥ó¥¯¥ë¡¼¥É¤Î¶Ø»ß).
-
-Âç°èÊÑ¿ô
-
- void rb_define_variable(char *name, VALUE *var,
-			 VALUE (*get_hook), VALUE (*set_hook)(), void *data)
-
-   Ruby¤ÈC¤È¤Ç¶¦Í­¤¹¤ë¥°¥í¡¼¥Ð¥ëÊÑ¿ô¤òÄêµÁ¤¹¤ë. get_hook¤¬Qnil¤Ç¤Ê¤¤»þ, 
-   ÊÑ¿ô»²¾È¤ÎºÝ¤Ëget_hook¤Ë¥»¥Ã¥È¤µ¤ì¤¿´Ø¿ô¤¬¸Æ¤Ð¤ì¤ë. set_hook¤¬Qnil 
-   ¤Ç¤Ê¤¤»þ¤Ë¤ÏÂåÆþ¤Î»þ¤Ëset_hook¤¬¸Æ¤Ð¤ì¤ë. hook´Ø¿ô¤Ë¤ÏÊÑ¿ô̾¤ò¼¨¤¹ 
-   ID¡¤(set hook¤Î¾ì¹ç¿·¤·¤¤Ãͤâ)¤È¤È¤â¤Ëdata¤ÇÍ¿¤¨¤¿¥Ç¡¼¥¿¤¬°ú¿ô¤È¤·
-   ¤ÆÅϤµ¤ì¤ë.
-
-   ÊÑ¿ô̾¤¬`$'¤Ç»Ï¤Þ¤é¤Ê¤¤»þ¤Ë¤Ï¼«Æ°Åª¤ËÄɲ䵤ì¤ë. ÊÑ¿ô̾¤È¤·¤Æruby¤Î
-   ¼±Ê̻ҤȤ·¤Æµö¤µ¤ì¤Ê¤¤Ê¸»ú(Î㤨¤Ð` ')¤ò´Þ¤à¾ì¹ç¤Ë¤Ïruby¥×¥í¥°¥é¥à¤«
-   ¤é¥¢¥¯¥»¥¹¤Ç¤­¤Ê¤¯¤Ê¤ë.
-
- void rb_global_variable(VALUE *var)
-
-   GC¤Î¤¿¤á¡¤Ruby¥×¥í¥°¥é¥à¤«¤é¤Ï¥¢¥¯¥»¥¹¤µ¤ì¤Ê¤¤¤¬, Ruby¥ª¥Ö¥¸¥§¥¯¥È
-   ¤ò´Þ¤àÂç°èÊÑ¿ô¤ò¥Þ¡¼¥¯¤¹¤ë.
-
- void rb_read_only_hook()
-
-   Æɤ߽Ф·ÀìÍѤÎÊÑ¿ô¤Î¤¿¤á¤Îset_hook´Ø¿ô. ÃͤòÀßÄꤷ¤è¤¦¤È¤¹¤ë¤ÈÎã³°
-   ¤òȯÀ¸¤µ¤»¤ë.
-
-¥¯¥é¥¹Äê¿ô
-
- void rb_define_const(VALUE class, char *name, VALUE val)
-
-   ¥¯¥é¥¹Äê¿ô¤òÄêµÁ¤¹¤ë.
-
-¥á¥½¥Ã¥ÉÄêµÁ
-
- rb_define_method(VALUE class, char *name, VALUE (*func)(), int argc)
-
-   ¥á¥½¥Ã¥É¤òÄêµÁ¤¹¤ë. argc¤Ïself¤ò½ü¤¯°ú¿ô¤Î¿ô. argc¤¬-1¤Î»þ, ´Ø¿ô¤Ë
-   ¤Ï°ú¿ô¤Î¿ô(self¤ò´Þ¤Þ¤Ê¤¤)¤òÂè1°ú¿ô, °ú¿ô¤ÎÇÛÎó¤òÂè2°ú¿ô¤È¤¹¤ë·Á¼°
-   ¤ÇÍ¿¤¨¤é¤ì¤ë(Âè3°ú¿ô¤Ïself). argc¤¬-2¤Î»þ, °ú¿ô¤Ïself, args(args¤Ï
-   °ú¿ô¤ò´Þ¤àruby¤ÎÇÛÎó)¤È¤¤¤¦·Á¼°¤ÇÍ¿¤¨¤é¤ì¤ë.
-
- rb_define_single_method(VALUE class, char *name, VALUE (*func)(), int argc)
-
-   Æðۥ᥽¥Ã¥É¤òÄêµÁ¤¹¤ë. °ú¿ô¤Ïrb_define_method()¤ÈƱ¤¸.
-
- rb_scan_args(int atgc, VALUE *argv, char *fmt, ...)
-
-   argc,argv·Á¼°¤ÇÍ¿¤¨¤é¤ì¤¿°ú¿ô¤òʬ²ò¤¹¤ë. fmt¤Ïɬ¿Ü°ú¿ô¤Î¿ô, Éղðú
-   ¿ô¤Î¿ô, »Ä¤ê¤Î°ú¿ô¤¬¤¢¤ë¤«¤ò»ØÄꤹ¤ëʸ»úÎó¤Ç, "¿ô»ú¿ô»ú*"¤È¤¤¤¦·Á¼°
-   ¤Ç¤¢¤ë.  2 ÈÖÌܤοô»ú¤È"*"¤Ï¤½¤ì¤¾¤ì¾Êά²Äǽ¤Ç¤¢¤ë. ɬ¿Ü°ú¿ô¤¬°ì¤Ä
-   ¤â¤Ê¤¤¾ì¹ç¤Ï0¤ò»ØÄꤹ¤ë¡¥Âè3°ú¿ô°Ê¹ß¤ÏÊÑ¿ô¤Ø¤Î¥Ý¥¤¥ó¥¿¤Ç, ³ºÅö¤¹¤ë
-   Í×ÁǤ¬¤½¤ÎÊÑ¿ô¤Ë³ÊǼ¤µ¤ì¤ë. Éղðú¿ô¤ËÂбþ¤¹¤ë°ú¿ô¤¬Í¿¤¨¤é¤ì¤Æ¤¤¤Ê
-   ¤¤¾ì¹ç¤ÏÊÑ¿ô¤ËQnil¤¬ÂåÆþ¤µ¤ì¤ë.
-
-Ruby¥á¥½¥Ã¥É¸Æ¤Ó½Ð¤·
-
- VALUE rb_funcall(VALUE recv, ID mid, int narg, ...)
-
-   ¥á¥½¥Ã¥É¸Æ¤Ó½Ð¤·. ʸ»úÎ󤫤émid¤òÆÀ¤ë¤¿¤á¤Ë¤Ïrb_intern()¤ò»È¤¦.
-
- VALUE rb_funcall2(VALUE recv, ID mid, int argc, VALUE *argv)
-
-   ¥á¥½¥Ã¥É¸Æ¤Ó½Ð¤·. °ú¿ô¤òargc,argv·Á¼°¤ÇÅϤ¹¡¥
-
- VALUE rb_eval_string(char *str)
-
-   ʸ»úÎó¤òruby¤È¥¹¥¯¥ê¥×¥È¤·¤Æ¥³¥ó¥Ñ¥¤¥ë¡¦¼Â¹Ô¤¹¤ë¡¥
-
- ID rb_intern(char *name)
-
-   ʸ»úÎó¤ËÂбþ¤¹¤ëID¤òÊÖ¤¹.
-
- char *rb_id2name(ID id)
-
-   ID¤ËÂбþ¤¹¤ëʸ»úÎó¤òÊÖ¤¹(¥Ç¥Ð¥Ã¥°ÍÑ).
-
- char *rb_class2name(VALUE class)
-
-   class¤Î̾Á°¤òÊÖ¤¹(¥Ç¥Ð¥Ã¥°ÍÑ). class¤¬Ì¾Á°¤ò»ý¤¿¤Ê¤¤»þ¤Ë¤Ï, °ìÈÖ¶á
-   ¤¤Ì¾Á°¤ò»ý¤Ä¥¯¥é¥¹¤Î̾Á°¤òÊÖ¤¹.
-
-¥¤¥ó¥¹¥¿¥ó¥¹ÊÑ¿ô
-
- VALUE rb_iv_get(VALUE obj, char *name)
-
-   obj¤Î¥¤¥ó¥¹¥¿¥ó¥¹ÊÑ¿ô¤ÎÃͤòÆÀ¤ë. `@'¤Ç»Ï¤Þ¤é¤Ê¤¤¥¤¥ó¥¹¥¿¥ó¥¹ÊÑ¿ô¤Ï 
-   Ruby¥×¥í¥°¥é¥à¤«¤é¥¢¥¯¥»¥¹¤Ç¤­¤Ê¤¤.
-
- VALUE rb_iv_set(VALUE obj, char *name, VALUE val)
-
-   obj¤Î¥¤¥ó¥¹¥¿¥ó¥¹ÊÑ¿ô¤òval¤Ë¥»¥Ã¥È¤¹¤ë.
-
-À©¸æ¹½Â¤
-
- VALUE rb_iterate(VALUE (*func1)(), char *arg1, VALUE (*func2)(), char *arg2)
-
-   func2¤ò¥Ö¥í¥Ã¥¯¤È¤·¤ÆÀßÄꤷ, func1¤ò¥¤¥Æ¥ì¡¼¥¿¤È¤·¤Æ¸Æ¤Ö.  func1¤Ë
-   ¤Ï arg1¤¬°ú¿ô¤È¤·¤ÆÅϤµ¤ì, func2¤Ë¤ÏÂè1°ú¿ô¤Ë¥¤¥Æ¥ì¡¼¥¿¤«¤éÍ¿¤¨¤é¤ì
-   ¤¿ÃÍ, Âè2°ú¿ô¤Ëarg2¤¬ÅϤµ¤ì¤ë.
- 
- VALUE rb_yield(VALUE val)
-
-   val¤òÃͤȤ·¤Æ¥¤¥Æ¥ì¡¼¥¿¥Ö¥í¥Ã¥¯¤ò¸Æ¤Ó½Ð¤¹.
-
- VALUE rb_resque(VALUE (*func1)(), char *arg1, VALUE (*func2)(), char *arg2)
-
-   ´Ø¿ôfunc1¤òarg1¤ò°ú¿ô¤Ë¸Æ¤Ó½Ð¤¹. func1¤Î¼Â¹ÔÃæ¤ËÎã³°¤¬È¯À¸¤·¤¿»þ¤Ë
-   ¤Ï func2¤òarg2¤ò°ú¿ô¤È¤·¤Æ¸Æ¤Ö. Ìá¤êÃͤÏÎã³°¤¬È¯À¸¤·¤Ê¤«¤Ã¤¿»þ¤Ï
-   func1¤ÎÌá¤êÃÍ, Îã³°¤¬È¯À¸¤·¤¿»þ¤Ë¤Ïfunc2¤ÎÌá¤êÃͤǤ¢¤ë.
-
- VALUE rb_ensure(VALUE (*func1)(), char *arg1, VALUE (*func2)(), char *arg2)
-
-   ´Ø¿ôfunc1¤òarg1¤ò°ú¿ô¤È¤·¤Æ¼Â¹Ô¤·, ¼Â¹Ô½ªÎ»¸å(¤¿¤È¤¨Îã³°¤¬È¯À¸¤·¤Æ
-   ¤â) func2¤òarg2¤ò°ú¿ô¤È¤·¤Æ¼Â¹Ô¤¹¤ë. Ìá¤êÃͤÏfunc1¤ÎÌá¤êÃͤǤ¢¤ë(Îã
-   ³°¤¬È¯À¸¤·¤¿»þ¤ÏÌá¤é¤Ê¤¤).
-
-Îã³°¡¦¥¨¥é¡¼
-
- void Warning(char *fmt, ...)
-
-   ɸ½à¥¨¥é¡¼½ÐÎϤ˷ٹð¾ðÊó¤òɽ¼¨¤¹¤ë. °ú¿ô¤Ïprintf()¤ÈƱ¤¸.
-
- void Fail(char *fmt, ...)
-
-   Îã³°¤òȯÀ¸¤µ¤»¤ë. °ú¿ô¤Ïprintf()¤ÈƱ¤¸.
-
- void Fatal(char *fmt, ...)
-
-   Ã×̿ŪÎã³°¤òȯÀ¸¤µ¤»¤ë. Ä̾ï¤ÎÎã³°½èÍý¤Ï¹Ô¤Ê¤ï¤ì¤º, ¥¤¥ó¥¿¡¼¥×¥ê¥¿
-   ¤¬½ªÎ»¤¹¤ë(¤¿¤À¤·ensure¤Ç»ØÄꤵ¤ì¤¿¥³¡¼¥É¤Ï½ªÎ»Á°¤Ë¼Â¹Ô¤µ¤ì¤ë).
-
- void Bug(char *fmt, ...)
-
-   ¥¤¥ó¥¿¡¼¥×¥ê¥¿¤Ê¤É¥×¥í¥°¥é¥à¤Î¥Ð¥°¤Ç¤·¤«È¯À¸¤¹¤ë¤Ï¤º¤Î¤Ê¤¤¾õ¶·¤Î»þ
-   ¸Æ¤Ö. ¥¤¥ó¥¿¡¼¥×¥ê¥¿¤Ï¥³¥¢¥À¥ó¥×¤·Ä¾¤Á¤Ë½ªÎ»¤¹¤ë. Îã³°½èÍý¤Ï°ìÀÚ¹Ô
-   ¤Ê¤ï¤ì¤Ê¤¤.
-
-ruby¤Î½é´ü²½¡¦¼Â¹Ô
-
- void ruby_init(int argc, char **argv, char **envp)
-
-  ruby¥¤¥ó¥¿¥×¥ê¥¿¤Î½é´ü²½¤ò¹Ô¤Ê¤¦.
-
- void ruby_run()
-
-  ruby¥¤¥ó¥¿¥×¥ê¥¿¤ò¼Â¹Ô¤¹¤ë.
-
- void ruby_script(char *name)
-
-  ruby¤Î¥¹¥¯¥ê¥×¥È̾($0)¤òÀßÄꤹ¤ë.
-
-/*
- * Local variables:
- * fill-column: 70
- * end:
- */
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�フリーソフトウェア��．2-clause BSDL
+���以下�示��件�本プログラムを��布����
+2-clause BSDL�����BSDLファイルを�照��下��．
+
+1. 複製�制���自由��．
+
+2. 以下��件���れ�を満��時�本プログラム�ソースを
+   自由�変更����．
+
+   a.  �ットニューズ��スト��り，作者�変更を�付�る
+       ���方法�，変更を公開�る．
+
+   b.  変更��本プログラムを自分�所属�る組織内部���
+       使�．
+
+   c.  変更点を明示����，ソフトウェア���を変更�る．
+       ��ソフトウェアを�布�る時��変更��本プログラ
+       ムも�時��布�る．���変更��本プログラム�ソー
+       ス�入手法を明示�る．
+
+   d.  ��他�変更�件を作者����る．
+
+3. 以下��件���れ�を満��時�本プログラムをコンパイ
+   ル��オブジェクトコードや実行形��も�布����．
+
+   a.  �イナリを�����人�ソースを入手��るよ��，
+       ソース�入手法を明示�る．
+
+   b.  機械�読�ソースコードを添付�る．
+
+   c.  変更を行���イナリ���を変更����，オリジナ
+       ル�ソースコード�入手法を明示�る．
+
+   d.  ��他��布�件を作者����る．
+
+4. 他�プログラム��引用����る目的��れ自由��．�
+   ��，本プログラム���れる他�作者�よるコード�，�
+   れ�れ�作者����よる制��加�られる場���り��．
+
+   �れらファイル�一覧��れ�れ��布�件���付���
+   LEGALファイルを�照������．
+
+5. 本プログラム��入力��るスクリプト�よ�，本プログラ
+   ム�ら�出力�権利�本プログラム�作者����，�れ�
+   れ�入出力を生���人�属���．��，本プログラム�
+   組�込�れる���拡張ライブラリ����も�様��．
+
+6. 本プログラム�無�証��．作者�本プログラムをサ�ート
+   �る�志��り���，プログラム自身��グ�る��本プ
+   ログラム�実行���ら発生�る���る�害�対��も責
+   任を����ん．
diff --git a/ChangeLog b/ChangeLog
deleted file mode 100644
index f66a446971..0000000000
--- a/ChangeLog
+++ /dev/null
@@ -1,270 +0,0 @@
-Mon Feb 20 16:10:14 1995  Yukihiro Matsumoto  (matz@ix-02)
-
-	* parse.y(yylex): Äê¿ô¤ò`%¼±ÊÌ»Ò'¤«¤é¡¤Âè1ʸ»ú¤¬Âçʸ»ú¤Î¼±Ê̻ҤËÊÑ
-	  ¹¹¡¥¤½¤ì¤Ë¤È¤â¤Ê¤¤¥¯¥é¥¹¤ÏÄê¿ô¤È¤Ê¤Ã¤¿¡¥
-
-	* eval.c: ¥¯¥é¥¹ÄêµÁÆâ¤Îself¤¬¥¯¥é¥¹ÄêµÁ³°Éô¤Îthe_class¤À¤Ã¤¿¡¥
-
-	* variable.c(rb_name_class): ¥¯¥é¥¹Ì¾¤ò¥¤¥ó¥¹¥¿¥ó¥¹ÊÑ¿ô¤Ë³ÊǼ¤¹¤ë¡¥
-
-Thu Feb 16 15:36:17 1995  Yukihiro Matsumoto  (matz@ix-02)
-
-	* parse.y: BLOCK¤òbrace¤Çɽ¸½¤¹¤ëʸˡ¤ËÊѹ¹¤·¤¿¤â¤Î¤òºî¤Ã¤Æ¤ß¤ë¡¥
-	  ML¤ËÄ󼨤·¤Æ¤ß¤ë¤¬È¿±þ¤¬¤Ê¤¤¡¥
-
-	* object.c(do,forever): ¤Ê¤¯¤·¤¿¡¥
-
-Wed Feb 15 13:20:49 1995  Yukihiro Matsumoto  (matz@ix-02)
-
-	* re.c(new): Âè2°ú¿ô¤¬Í¿¤¨¤é¤ì¤Æ¡¤¤«¤Änil¤Ç¤Ê¤¤¤È¤­¤À¤±ÀßÄꤹ¤ë¤è
-	  ¤¦¤Ë(°ÊÁ°¤Ïnil¤Î»þ¤Ë¤âÀßÄê¤ò¹Ô¤Ê¤Ã¤Æ¤¤¤¿)¡¥
-
-	* parse.y(parse_regexp): Àµµ¬É½¸½¥ê¥Æ¥é¥ë¤ÇÂçʸ»ú¾®Ê¸»ú¤ò̵»ë¤¹¤ë
-	  ¤«¤É¤¦¤«»ØÄê¤Ç¤­¤ë¤è¤¦¤Ë¡¥
-
-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¤òÆɤ߹þ¤à»þ¤À¤±"#!"¤Î²òÀϤò¹Ô¤¦¤è¤¦¤Ë¡¥
-
-	* ruby.c(readin): ¥Õ¥¡¥¤¥ëÆɤ߹þ¤ß»þ¤ËÀèƬ¤Ë"#!"¤¬¤¢¤ê¡¤ruby¤Ë°ú¿ô
-	  ¤¬Í¿¤¨¤é¤ì¤Æ¤¤¤ì¤Ð¡¤¤½¤Î°ú¿ô¤âÍ­¸ú¤Ë¤Ê¤ë¡¥
-
-	* parse.y(yylex): ¥³¥á¥ó¥È¹Ô¤Î½ª¤ê¤¬`\'¤Ç¤¢¤Ã¤¿»þ¡¤¼¡¤Î¹Ô¤Ë·Ñ³¤·
-	  ¤Æ¤¤¤ë¤È¤ß¤Ê¤¹¤è¤¦¤Ë¤·¤¿¡¥
-
-Thu Feb  9 16:18:37 1995  Yukihiro Matsumoto  (matz@ix-02)
-
-	* parse.y: protect¤òbegin¤ËÊѹ¹¡¥begin..end¤ÏÎã³°½èÍý¤À¤±¤Ç¤Ê¤¯¡¤
-	  ʸ³ç¸Ì¤È¤·¤Æ¤âƯ¤¯¤³¤È¤Ë¤Ê¤Ã¤¿¡¥
-
-Wed Feb  1 19:48:24 1995  Yukihiro Matsumoto  (matz@ix-02)
-
-	* string.c(str_replace): ÃÖ¤­´¹¤¨¤ëʸ»úÎó¤ÎŤµ¤¬Åù¤·¤¤»þ¥á¥â¥ê¥³
-	  ¥Ô¡¼¤ò¤·¤Ê¤¤¡¥
-
-	* string.c(rindex): ¥Ð¥°½¤Àµ¡¥
-
-Mon Jan 30 11:23:05 1995  Yukihiro Matsumoto  (matz@ix-02)
-
-	* parse.y(value_expr): if¤Î¥Á¥§¥Ã¥¯¤òÄɲá¥
-
-	* gc.c(gc_mark): free cell¤Î°·¤¤¤Ë¥Ð¥°¡¥
-
-	* parse.y: ʸˡ¤ÎÊѹ¹(¤è¤ê¥·¥ó¥×¥ë¤Ë)¡¥Îã³°¤ò¸º¤é¤·¤¿¡¥
-
-Thu Jan 26 00:52:55 1995  Yukihiro Matsumoto  (matz@dyna)
-
-	* parse.y: °ú¿ô¤È¤·¤ÆÏ¢ÁÛÇÛÎó¤òÃÖ¤¯¤³¤È¤¬¤Ç¤­¤ë¤è¤¦¤Ë¡¥¤³¤Î¾ì¹ç¡¤
-	  Ï¢ÁÛÇÛÎó¥ê¥Æ¥é¥ë¤¬ºÇ½ª°ú¿ô¤È¤Ê¤ë¡¥
-
-	* parse.y: ÇÛÎ󻲾ȤÎ`[]'Æ⤬¶õ¤Ç¤â¤è¤¤¤³¤È¤Ë¤·¤¿¡¥
-
-Tue Jan 24 14:45:15 1995  Yukihiro Matsumoto  (matz@ix-02)
-
-	* class.c(rb_include_module): `-v'¤ò»ØÄꤷ¤¿»þ¤Ë¤Ïinclude¤·¤¿¥â¥¸¥å¡¼
-	  ¥ë¤È¥¯¥é¥¹Äê¿ô¤¬¾×Æͤ·¤Æ¤¤¤Ê¤¤¤«¥Á¥§¥Ã¥¯¤¹¤ë¡¥
-
-Mon Jan 23 10:42:09 1995  Yukihiro Matsumoto  (matz@ix-02)
-
-	* parse.y(rb_class2name): ¥á¥¿¥¯¥é¥¹¤Ë´Ø¤¹¤ëbug fix.
-
-	* dict.c: Dict[..]¤Ç¼­½ñ¤ÎÀ¸À®¤¬½ÐÍè¤ë¤è¤¦¤Ë¡¥
-
-	* array.c: Array[..]¤ÇÇÛÎó¤ÎÀ¸À®¤¬½ÐÍè¤ë¤è¤¦¤Ë¡¥
-
-	* parse.y: ¼­½ñ¤Îɽ¸½¤È¤·¤Æ{a,b,..}¤È¤¤¤¦·Á¼°¤âµö¤¹¤è¤¦¤Ë¡¥
-
-Fri Jan 20 10:28:38 1995  Yukihiro Matsumoto  (matz@ix-02)
-
-	* re.c(Regexp.quote): Àµµ¬É½¸½¤ò¥¨¥¹¥±¡¼¥×¤¹¤ë¥á¥½¥Ã¥É¡¥
-
-	* ̵Â̤Êrb_intern()¤ò¸º¤é¤·¤¿¡¥
-
-	* parse.y: `!', `!=', `!~'¤òÆüì±é»»»Ò¤Ë¤¹¤ë¡¥¤è¤Ã¤Æ¤³¤ì¤é¤ÏºÆÄêµÁ
-	  ¤Ç¤­¤Ê¤¯¤Ê¤Ã¤¿¡¥
-
-Wed Jan 18 13:20:41 1995  Yukihiro Matsumoto  (matz@ix-02)
-
-	* parse.y: ʸˡ¤ÎÀ°Íý(unless,until¤ò¤Ê¤¯¤·¤¿)¡¥
-
-Tue Jan 17 11:11:27 1995  Yukihiro Matsumoto  (matz@ix-02)
-
-	* eval.c: def¤Ç¥á¥½¥Ã¥ÉºÆÄêµÁ»þ¤Ë¤Ï¥¹¡¼¥Ñ¡¼¥¯¥é¥¹¤Î¥á¥½¥Ã¥É¤Î²Ä»ë
-	  À­¤ò·Ñ¾µ¤¹¤ë¡¥ºÇ½é¤ÎÄêµÁ¤Î»þ¤Ïº£¤Þ¤Ç¤ÈƱ¤¸¥Ç¥Õ¥©¥ë¥È(¥È¥Ã¥×¥ì¥Ù
-	  ¥ë¤Ç´Ø¿ôŪ¡¤¥¯¥é¥¹ÄêµÁÆâ¤ÇÄ̾ï¥á¥½¥Ã¥É)¡¥
-
-	* object.c(Class::new): ¥ª¥Ö¥¸¥§¥¯¥È¤ÎÀ¸À®»þ¤Ë´Ø¿ôŪ¥á
-	  ¥½¥Ã¥Éinit_object¤¬É¬¤º¸Æ¤Ð¤ì¤ë¤è¤¦¤ËÊѹ¹¡¥
-
-	* eval.c: ̤ÄêµÁ¤Î¥á¥½¥Ã¥É¤ËÂФ·¤Æunknown¥á¥½¥Ã¥É¤¬¸Æ¤Ð¤ì¤ë¤è¤¦¤Ë
-	  ¤Ê¤Ã¤¿¡¥¥¨¥é¡¼É½¼¨¤¬º£¤Þ¤Ç¤ÈƱ¤¸¤Ë¤Ê¤ë¤è¤¦¤Ëenv¤òÄ´Àᤷ¤Æ¤¤¤ë¡¥
-
-Fri Jan 13 14:40:30 1995  Yukihiro Matsumoto  (matz@ix-02)
-
-	* gc.c: gc¤ò¼ã´³½ñ¤­´¹¤¨¤ÆÀ°Íý¤·¤¿¡¥¤¬¡¤¤¢¤Þ¤êÊѲ½¤Ï¤Ê¤«¤Ã¤¿¤è¤¦¤À¡¥
-
-	* parse.y(yylex): symbol¤ò\sym¤«¤é:sym¤ËÊѹ¹¤·¤¿¡¥
-
-Thu Jan 12 01:39:28 1995  Yukihiro Matsumoto  (matz@dyna)
-
-	* eval.c: ¿·µ¬´Ø¿ô rb_eval_string()¡¥
-
-	* gc.c: gc_mark()¤ò°ìÉôÈóºÆµ¢²½¡¥
-
-	* variable.c(rb_ivar_{get,set}): ¥¤¥ó¥¹¥¿¥ó¥¹ÊÑ¿ô¤Î¥¢¥¯¥»¥¹¼þ¤ê¤Ç
-	  ¥Á¥§¥Ã¥¯¤¬Â­¤ê¤Ê¤«¤Ã¤¿¡¥
-
-	* variable.c: ¥¯¥é¥¹Äê¿ô¤È¥¤¥ó¥¹¥¿¥ó¥¹ÊÑ¿ô¤Ç¥Ï¥Ã¥·¥å¥Æ¡¼¥Ö¥ë¤ò¶¦Í­
-	  ¤¹¤ë¤è¤¦¤Ë¤·¤¿¡¥
-
-	* ruby.h: iv_tbl¤òRBasic¤«¤éRObject¤ÈRClass¤Ø°ÜÆ°¤·¤¿¡¥¤³¤ì¤Ë¤è¤ê¡¤
-	  Object¤ÈClass,Module¤·¤«¥¤¥ó¥¹¥¿¥ó¥¹ÊÑ¿ô¤ò»ý¤Æ¤Ê¤¯¤Ê¤ë¡¥¤¬¡¤¥á¥â
-	  ¥ê¸úΨ¤Ï¼ã´³¸þ¾å¤¹¤ë¡¥
-
-Tue Jan 10 00:58:20 1995  Yukihiro Matsumoto  (matz@dyna)
-
-	* 0.64 released
-
-	* eval.c: ¥ì¥·¡¼¥Ð¤È°ú¿ô¤Ï¾ï¤Ëiter¤Ç¤Ï¤Ê¤¤¡¥
-
-	* cons.c(aref,aset): negative offsetÂбþ¡¥
-
-Mon Jan  9 14:40:39 1995  Yukihiro Matsumoto  (matz@ix-02)
-
-	* parse.y: foo{..}¤Î·Á¼°¤Ë¤ª¤¤¤Æ¡¤foo¤ò¥í¡¼¥«¥ëÊÑ¿ô¤ä¥¯¥é¥¹Ì¾¤Ç¤Ï
-	  ¤Ê¤¯¡¤°ú¿ô¤Ê¤·¤Î´Ø¿ô·¿¥á¥½¥Ã¥É¸Æ¤Ó½Ð¤·¤È¤ß¤Ê¤¹¤è¤¦¤Ë¤·¤¿¡¥
-
-	* list.c -> cons.c: ̾¾ÎÊѹ¹(¥¯¥é¥¹Ì¾¤â)¡¥
-
-	* list.c: a::b::c::nil¤ò¥ê¥¹¥È(a b c)¤È¤ß¤Ê¤¹lisp·Á¼°¤«¤é¡¤a::b::c
-	  ¤ò¥ê¥¹¥È(a b c)¤È¤ß¤Ê¤¹ruby·Á¼°¤ËÊѹ¹¡¥[], []=, each¤â¤½¤ì¤Ë²ñ¤ï
-	  ¤»¤¿»ÅÍͤȤ¹¤ë¡¥
-
-	* list.c: cons¥Ú¥¢¤È¤·¤Æ¤Îµ¡Ç½¤ò¶¯Ä´¡¥»ÅÍÍÊѹ¹¡¥
-
-Sat Jan  7 01:26:26 1995  Yukihiro Matsumoto  (matz@dyna)
-
-	* eval.c: ¼«¸ÊÂåÆþ¤ÎÉÔ¶ñ¹ç½¤Àµ¡¥
-
-	* eval.c(masign): ¿½ÅÂåÆþ¤¬ÇÛÎó¤â¥ê¥¹¥È¤â¤È¤ì¤ë¤è¤¦¤Ë¤·¤¿¡¥
-
-	* list.c: assoc¤ò2Í×ÁǤÎÇÛÎ󤫤éList(CONS¥Ú¥¢)¤ËÊѹ¹¤·¤¿¡¥
-
-Fri Jan  6 13:42:12 1995  Yukihiro Matsumoto  (matz@ix-02)
-
-	* parse.y: a[b]+=c¤äa.b+=c¤Ê¤É¤Î¼«¸ÊÂåÆþ·Á¼°¤Ç¡¤a¤äb¤ò2ÅÙɾ²Á¤·¤Ê
-	  ¤¯¤Ê¤Ã¤¿¡¥
-
-	* eval.c: iteratorÀßÄê¤Î¥Ð¥°¥Õ¥£¥Ã¥¯¥¹¡¥
-
-	* list.c: List¥¯¥é¥¹¤ò¿·Àß¡¥
-
-Thu Jan  5 13:55:00 1995  Yukihiro Matsumoto  (matz@ix-02)
-
-	* parse.y: SCOPE¤Î¥á¥â¥ê¥ê¡¼¥¯¤ò¤Ê¤¯¤·¤¿¡¥
-
-	* eval.c: built-in¥á¥½¥Ã¥É¤Ø¤Î°ú¿ô¤Î°ú¤­ÅϤ·Êý¤òÊѹ¹¤·¤Æ¡¤ÇÛÎó¤ÎÀ¸
-	  À®¿ô¤ò¸º¤é¤·¤¿¡¥
-
-	* re.c: match-data¤òËè²óÀ¸À®¤¹¤ë¤³¤È¤ò¤ä¤á¤¿¡¥`$~'¤ò¥¢¥¯¥»¥¹¤·¤¿»þ
-	  ¤Ëon-demand¤ÇÀ¸À®¤¹¤ë¡¥
-
-	* string.c etc: ÉÔɬÍפÊmemmove¤òmemcpy¤ËÃÖ´¹¡¥
-
-	* parse.y: =~, !~¤ÏÉûºîÍѤ¬¤¢¤ë¤Î¤Ç¥³¥ó¥Ñ¥¤¥ë»þ¤ËŸ³«¤Ç¤­¤Ê¤¤¡¥
-
-Tue Jan  3 02:04:36 1995  Yukihiro Matsumoto  (matz@dyna)
-
-	* eval.c: rest°ú¿ô¤Îbug fix.
-
-	* eval.c,gc.c: scope¤ò¥ª¥Ö¥¸¥§¥¯¥È¤Ë¤·¤¿¡¥
-
-	* eval.c: env¤Èscope¤Î°·¤¤¤òÊѹ¹¤·¤¿¡¥
-
-Wed Dec 28 09:46:57 1994  Yukihiro Matsumoto  (matz@ix-02)
-
-	* parse.y: eval¤Ç¥í¡¼¥«¥ëÊÑ¿ô¤¬Äɲ䵤줿¾ì¹ç¤ËÂбþ¤·¤¿¡¥
-
-	* parse.y: ±é»»»Ò¤ò´Þ¤àalias¤Îbug fix.
-
-Tue Dec 27 16:45:20 1994  Yukihiro Matsumoto  (matz@ix-02)
-
-	* parse.y: def A B¤òalias A B¤ËÊѹ¹¡¥
-
-	* eval.c: alias´Ø·¸¤Îbug½¤Àµ¡¥node¤ò¥ª¥Ö¥¸¥§¥¯¥È²½¤·¤¿»þ¤Ëenbug¤·
-	  ¤¿¤è¤¦¤À¡¥
-
-	* signal.c: ¥·¥¹¥Æ¥à¥³¡¼¥ë¤ÎºÆÄêµÁ¤ò»ß¤á¤¿¡¥
-
-	* io.c(select): write/except¤Î¥Õ¥é¥°ÀßÄê¤Ë¥Ð¥°¡¥
-
-	* Makefile.in: static linkÍÑ¥ª¥×¥·¥ç¥ó¤òMakeÊÑ¿ô¤È¤·¤ÆÆÈΩ¤µ¤»¤¿¡¥
-
-Tue Dec 20 00:46:19 1994  Yukihiro Matsumoto  (matz@dyna)
-
-	* 0.63 released
-
-	* eval.c(rb_call): super¤Î¸Æ¤Ó½Ð¤·¤ÇÍî¤Á¤ë¡¥argc, argv¤ÎÀßÄê¤ò˺¤ì
-	  ¤Æ¤¤¤¿¡¥
-
-	* parse.y(read_escape): Ÿ³«¥¨¥é¡¼¡¥
-
-	* variable.c: ÄêµÁºÑ¤ß¤ÎÊÑ¿ô¤Îhook¤òÊѹ¹¤·¤Ê¤¤¤è¤¦¤Ë¡¥
-
-Mon Dec 19 12:01:10 1994  Yukihiro Matsumoto  (matz@ix-02)
-
-	* parse.y(cond): ¾ò·ï¼°¤ËÂåÆþ¼°¤¬ÃÖ¤«¤ì¤¿¾ì¹ç¡¤`-v'¥ª¥×¥·¥ç¥ó¤Ç·Ù
-	  ¹ð¤¬½Ð¤ë¤è¤¦¤Ë¡¥
-
-	* parse.y(**): ÑѾè±é»»»Ò`**'¤ÎÍ¥Àè½ç°Ì¤òñ¹à±é»»»Ò¤è¤ê¹â¤¯¤·¤¿¡¥
-
-	* parse.y(and,or): Í¥Àè½ç°Ì¤ÎÄ㤤±é»»»Ò`and', `or'.
-
-	* 0.62 released.
-
-	* eval.c: ÉÔɬÍפˤʤä¿PUSH_ENV, POP_ENV¤ò¸º¤é¤·¤¿¡¥
-
-	* env.h: ENVION¤«¤éself¤ò¤Ï¤º¤·¤¿¡¥PUSH_ENV¤Ïsuper¤Î½àÈ÷¤Î¤¿¤á¤À¤±
-	  ¤ËÍѤ¤¤ë¤³¤È¤Ë¤·¤¿¡¥
-
-	* eval.c: ²¼µ­¤Î¥ª¥Ö¥¸¥§¥¯¥È²½¤ÇÃÙ¤¯¤Ê¤Ã¤¿¼Â¹Ô®ÅÙ¤ò¤â¤È¤ËÌᤷ¤¿¡¥
-
-Mon Dec 17 23:01:10 1994  Yukihiro Matsumoto  (matz@ix-02)
-
-	* eval.c: env.{argv,argc}¤Èscope.local_vars¤Î¥ª¥Ö¥¸¥§¥¯¥È²½¡¥
-
-	* eval.c: 1¥¹¥³¡¼¥×Æâ¤ÇÊ£¿ôBlock¤òÀ¸À®¤·¤¿¤È¤­¤Î¥Ð¥°¤ò½¤Àµ¡¥
-
-Fri Dec 16 15:52:06 1994  Yukihiro Matsumoto  (matz@ix-02)
-
-	* parse.y: `&&'¤È`||'¤ÎξÊդϤ¤¤Ä¤Ç¤â¾ò·ï¼°¤È¤·¤¿¡¥
-
-Thu Dec 15 00:16:04 1994  Yukihiro Matsumoto  (matz@dyna)
-
-	* eval.c(Block): Block¥ª¥Ö¥¸¥§¥¯¥È¤ò¼Â¸½¡¥
-
-	* node.h: NODE_QLIST¤Ï¤Ê¤¯¤Ê¤Ã¤¿¡¥
-
-	* eval.c(rb_call): °ú¿ô¤Ø¤ÎÂåÆþ¤ò̾Á°¤Ç°ì¤Ä¤º¤ÄÂåÆþ¤¹¤ë¤Î¤ò¤ä¤á¤Æ¡¤
-	  °ìÅ٤˥³¥Ô¡¼¤¹¤ë¤è¤¦¤Ë¤·¤¿¡¥
-
-	* eval.c(rb_call): ruby¤Çµ­½Ò¤µ¤ì¤¿¥á¥½¥Ã¥É¤Ø¤Î°ú¿ôÅϤ·¤òinline²½¡¥
-
-	* eval.c: ¥¤¥Æ¥ì¡¼¥¿È½Äê½èÍý¤ÎÁ´Ì̽ñ¤­´¹¤¨¡¥ÉÔŬÀڤʥ¤¥Æ¥ì¡¼¥¿¸Æ¤Ó
-	  ½Ð¤·¤ò¤Ê¤¯¤·¤¿¡¥Î㤨¤Ð¡Ö[foo(),bar()]{i|baz(i)}¡×¤Çfoo¤âbar¤â¥¤
-	  ¥Æ¥ì¡¼¥¿¤È¤·¤Æ¸Æ¤Ó½Ð¤µ¤ì*¤Ê¤¤*¡¥
-
-	* eval.c(rb_call): SCOPE½èÍý¤òinline²½¡¥¥á¥½¥Ã¥É¸Æ¤Ó½Ð¤·¤Î¼ã´³¤Î¹â
-	  ®²½¡¥
-
-Wed Dec 14 18:09:33 1994  Yukihiro Matsumoto  (matz@ix-02)
-
-	* node.h: node¤â¥ª¥Ö¥¸¥§¥¯¥È¤Ë¤¹¤ë¡¥¤è¤Ã¤ÆGC¤Ç²ó¼ý¤µ¤ì¤ë¡¥
-
-Thu Dec  8 14:17:29 1994  Yukihiro Matsumoto  (matz@ix-02)
-
-	* 0.60 released - alpha test baseline.
diff --git a/FAQ b/FAQ
deleted file mode 100644
index eaa9c86056..0000000000
--- a/FAQ
+++ /dev/null
@@ -1,65 +0,0 @@
-.\" FAQ -  -*- Indented-Text -*- created at: Tue Jan  4 12:48:12 JST 1994
-¤³¤ì¤ÏRuby¤Ë´Ø¤¹¤ëFAQ(Frequently Asked Question)¤ò¤Þ¤È¤á¤¿¤â¤Î¤Ç¤¹.
-Emacs¤Ç¤³¤Î¥Õ¥¡¥¤¥ë¤ò¸«¤Æ¤¤¤ë¾ì¹ç¤Ë¤ÏM-2 C-x $¤Ç¼ÁÌä¤ÎÉôʬ¤À¤±¤òÆɤळ
-¤È¤¬¤Ç¤­¤Þ¤¹. C-x $¤ÇÁ´¤Æ¤òÆɤà¾õÂÖ¤ËÌ᤻¤Þ¤¹.
-------------------------------
-1) Ruby¤Î̾¾Î¤ÎͳÍè¤Ï
-    
-    Ruby¤Ï²¿¤«¤Îά¾Î¤Ç¤Ï¤Ê¤¯, ÀÖ¤¤ÊõÀФÎ̾Á°¤ò¤È¤Ã¤Æ̾ÉÕ¤±¤é¤ì¤Þ¤·¤¿. 
-    perl(pearl¤Ï6·î¤ÎÃÂÀ¸ÀÐ)¤Î¼¡¤òÌܻؤ¹(Ruby¤Ï7·î¤ÎÃÂÀ¸ÀÐ)¤È¤¤¤¦°ÕÌ£
-    ¤¬¤¢¤ê¤Þ¤¹. ¹¹¤ËÈþ¤·¤¯²ÁÃͤ¢¤ë¤â¤Î¤Ç¤¢¤Ã¤ÆÍߤ·¤¤¤È¤¤¤¦´ê¤¤¤â´Þ¤Þ¤ì
-    ¤Æ¤¤¤Þ¤¹.
-------------------------------
-2) Ruby¤¬±Æ¶Á¤ò¼õ¤±¤¿¸À¸ì¤Ï?
-   
-    Ruby¤Î¸À¸ì»ÅÍͤÏC, Perl, Eiffel¤Î³Æ¸À¸ì¤Ë¤³¤Î½ç¤Ë±Æ¶Á¤ò¼õ¤±¤Æ¤¤¤Þ
-    ¤¹. ¤½¤Î¾¤Ë±Æ¶Á¤ò¼õ¤±¤¿¸À¸ì¤È¤·¤Æ¤Ïtcl, AWK, bourne shell, CLU,
-    Icon, Sather, Smalltalk, Emacs Lisp¤Ê¤É¤¬¤¢¤ê¤Þ¤¹.
-------------------------------
-3) Ruby¤ÎÆÃħ¤Ï?
-    
-    °Ê²¼¤Ë²Õ¾ò½ñ¤Ë¤·¤Þ¤¹.
-    
-      + ¥¤¥ó¥¿¥×¥ê¥¿¤Ç¤¢¤ê, ¼ê·Ú¤Ë¥×¥í¥°¥é¥à¤Ç¤­¤ë.
-      + ÊÑ¿ôÀë¸À¤¬Íפé¤Ê¤¤.
-      + ¥Õ¥¡¥¤¥ë¤ä¥¹¥È¥ê¡¼¥à¤Ê¤É¤Ø¤ÎUNIXŪ¤ÊÁàºî¤¬´Êñ¤Ë¤Ç¤­¤ë.
-      + ¥Ð¥¤¥Ê¥ê¥Õ¥¡¥¤¥ë¤â°·¤¨¤ë.
-      + ¤­¤Á¤ó¤È¤·¤¿¥ª¥Ö¥¸¥§¥¯¥È»Ø¸þ¸À¸ì¤Ç¤¢¤ë.
-      + Æðۥ᥽¥Ã¥É¤Îµ¡Ç½¤¬Ä󶡤µ¤ì¤Æ¤¤¤ë.
-      + ¥â¥¸¥å¡¼¥ë¤Ë¤è¤ëµ¡Ç½¤Î¶¦Í­¤¬¤Ç¤­¤ë.
-      + Îã³°½èÍýµ¡Ç½¤¬¤¢¤ë.
-      + GC¤¬¤¢¤ë¤Î¤Ç¥á¥â¥ê´ÉÍý¤òµ¤¤Ë¤·¤Ê¤¯¤ÆºÑ¤à.
-      + °ì´ÓÀ­¤Î¤¢¤ë¸À¸ì»ÅÍÍ.
-      + Ê£»¨¤Ê¥Ç¡¼¥¿¹½Â¤¤â°·¤¨¤ë.
-      + ¥À¥¤¥Ê¥ß¥Ã¥¯¥í¡¼¥É¤ò¥µ¥Ý¡¼¥È¤¹¤ë(¥·¥¹¥Æ¥à¤Ë¤è¤ë).
-    
-    µÕ¤Ë·çÅÀ¤Ï
-    
-      - ȯŸÅÓ¾å¤Çµ¡Ç½¤¬¾¯¤Ê¤¤.
-      - ¥Ç¥Ð¥Ã¥¬¤¬(¤Þ¤À)¤Ê¤¤.
-      - ÃÙ¤¤.
-      
-    ¤³¤È¤Ç¤·¤ç¤¦¤«.
-------------------------------
-4) Ruby¤ËÊÑ¿ôÀë¸À¤¬¤Ê¤¤¤³¤È¤Î¥á¥ê¥Ã¥È¤Ï?
-    
-    ¤¢¤ëÊÑ¿ô¤¬¤É¤Î¥¹¥³¡¼¥×¤Ë°¤¹¤ë¤«¤¬°ìÌܤÇʬ¤«¤ë¤Î¤Ç, ¥×¥í¥°¥é¥à¤ÎÆɤß
-    °×¤µ, Íý²ò¤·°×¤µ¤¬Áý¤¹¤³¤È¤¬ºÇÂç¤Î¥á¥ê¥Ã¥È¤Ç¤¹. ¤Þ¤¿¥È¡¼¥¿¥ë¤Î¥¿¥¤¥×
-    Î̤¬¸º¤ë¤Î¤Ç½ñ¤­°×¤µ, ¼ê·Ú¤µ¤Ë¤â¹×¸¥¤·¤Þ¤¹.
-------------------------------
-5) Ruby¤ÈPerl¤Î°ã¤¤¤Ï?
-    
-    Ruby¤ÈPerl¤Ï¥Æ¥­¥¹¥ÈÁàºî¤ËÍ¥¤ì¤¿¥¹¥¯¥ê¥×¥È¸À¸ì¤Ç¤¢¤ë¤È¤¤¤¦ÅÀ¤Ç, ¥«
-    ¥Ð¡¼¤¹¤ëÈϰϤ¬¶á¤¯, °ì¸«¤¹¤ë¤È¥é¥¤¥Ð¥ë¤Ë¸«¤¨¤Þ¤¹. ³Î¤«¤ËRuby¤ÎÀß·×
-    ¤Ë¤ª¤¤¤Æ¡ÖPerl¤Ë¤Ç¤­¤ë¤³¤È¤Ï¤Ç¤­¤ë¤è¤¦¤Ë¡×¤È¤¤¤¦¤³¤È¤Ï, °ì¤Ä¤Î½ÅÍ×
-    ¤ÊÌÜɸ¤Ç¤·¤¿. ¤·¤«¤·, Ruby¤Î¿¿¤ÎÌÜŪ¤Ï¤¢¤¯¤Þ¤Ç¤â¡Ö¼ê·Ú¤Ê¥ª¥Ö¥¸¥§¥¯
-    ¥È»Ø¸þ¸À¸ì¡×¤Ç¤¢¤ê, ¤Þ¤¿, RubyÀ߷פÎ3ÂçÌÜɸ¤Ç¤¢¤ë, µ¡Ç½À­¡¦°ì´ÓÀ­¡¦
-    ³ÈÄ¥À­¤Î·ë²Ì¤È¤·¤Æ, Ruby¤ÏPerl¤È¤Ï°Û¤Ê¤ë¸À¸ì¤Ë¤Ê¤ê¤Þ¤·¤¿.
-    
-    Ruby¤ÏPerl¤Û¤É¡Ö²¿¤Ç¤â¤¢¤ê¡×¤Ç¤Ï¤¢¤ê¤Þ¤»¤ó¤·, ¤Û¤È¤ó¤É¤Î¾ì¹çPerl¤è
-    ¤ê½èÍý®ÅÙ¤¬ÃÙ¤¤¤Ç¤¹. ¤·¤«¤·, Ruby¤Î¥ª¥Ö¥¸¥§¥¯¥È»Ø¸þµ¡Ç½¤ÏPerl¤Ç¤Ï
-    Ëþ­¤Ç¤­¤Ê¤¤¿Í¤¿¤Á¤Ë¥¢¥Ô¡¼¥ë¤¹¤ë¤È»×¤¤¤Þ¤¹.
-------------------------------
-Local variables:
-fill-column: 70
-end:
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..565c4c9cde
--- /dev/null
+++ b/LEGAL
@@ -0,0 +1,935 @@
+# -*- 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.
+
+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.
+
+  >>>
+    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.
+
+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::
+
+  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/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.
+
+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.
+
+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::
+
+  This file is licensed under the GPL, but is 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,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.  Note that the
+  paragraph 3 below is now null and void.
+
+  >>>
+    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.
+
+    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.
+
+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::
+ext/sdbm/_sdbm.c::
+ext/sdbm/sdbm.h::
+
+  These files are all under public domain.
+
+missing/crypt.c::
+
+  This file is under the old-style BSD license.  Note that the
+  paragraph 3 below is now null and void.
+
+  >>>
+    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.
+
+    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.
+
+missing/setproctitle.c::
+
+  This file is under the old-style BSD license.  Note that the
+  paragraph 3 below is now null and void.
+
+  >>>
+    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.
+
+    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.
+
+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/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 (see the file MIT.txt), 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::
+
+      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.
diff --git a/MANIFEST b/MANIFEST
deleted file mode 100644
index 429e921074..0000000000
--- a/MANIFEST
+++ /dev/null
@@ -1,67 +0,0 @@
-C-IF
-ChangeLog
-FAQ
-MANIFEST
-Makefile.in
-README
-ToDo
-array.c
-bignum.c
-class.c
-compar.c
-configure
-configure.in
-cons.c
-dbm.c
-defines.h
-dict.c
-dir.c
-dln.c
-dln.h
-enum.c
-env.h
-error.c
-etc.c
-eval.c
-file.c
-fnmatch.c
-fnmatch.h
-gc.c
-getopt.c
-getopt.h
-getopt1.c
-glob.c
-gnuglob.c
-ident.h
-inits.c
-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
-signal.c
-socket.c
-spec
-sprintf.c
-st.c
-st.h
-string.c
-struct.c
-time.c
-variable.c
-version.c
-version.h
diff --git a/Makefile.in b/Makefile.in
deleted file mode 100644
index b0c6eb5ea9..0000000000
--- a/Makefile.in
+++ /dev/null
@@ -1,178 +0,0 @@
-SHELL = /bin/sh
-
-#### Start of system configuration section. ####
-
-srcdir = @srcdir@
-VPATH = @srcdir@
-
-CC = @CC@
-DBMCC = cc
-YACC = @YACC@
-INSTALL = @INSTALL@
-INSTALL_PROGRAM = @INSTALL_PROGRAM@
-INSTALL_DATA = @INSTALL_DATA@
-PURIFY=
-
-CFLAGS = -g
-STATIC = @STATIC@
-LDFLAGS = $(CFLAGS)
-LIBS = @LIBS@
-MISSING = @LIBOBJS@ @ALLOCA@
-
-prefix = /usr/local
-binprefix = 
-exec_prefix = $(prefix)
-bindir = $(exec_prefix)/bin
-
-#### End of system configuration section. ####
-
-HDRS          = defines.h \
-		dln.h \
-		getopt.h \
-		ident.h \
-		io.h \
-		node.h \
-		re.h \
-		regex.h \
-		ruby.h \
-		st.h \
-		version.h
-
-OBJS	      = array.o \
-		bignum.o \
-		class.o \
-		compar.o \
-		cons.o \
-		dbm.o \
-		dict.o \
-		dir.o \
-		dln.o \
-		enum.o \
-		error.o \
-		etc.o \
-		eval.o \
-		file.o \
-		fnmatch.o \
-		gc.o \
-		getopt.o \
-		getopt1.o \
-		glob.o \
-		gnuglob.o \
-		inits.o \
-		io.o \
-		main.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 \
-		socket.o \
-		sprintf.o \
-		st.o \
-		string.o \
-		struct.o \
-		time.o \
-		variable.o \
-		version.o \
-		$(MISSING)
-
-PROGRAM	      = ruby
-
-all:		$(PROGRAM)
-
-$(PROGRAM):     $(OBJS)
-		@rm -f $(PROGRAM)
-		$(PURIFY) $(CC) $(STATIC) $(LDFLAGS) $(OBJS) $(LIBS) -o $(PROGRAM)
-
-$(bindir)/$(PROGRAM): $(PROGRAM)
-	$(INSTALL_PROGRAM) $(PROGRAM) $(bindir)/$(PROGRAM)
-
-install: $(bindir)/$(PROGRAM)
-
-clean:;		@rm -f $(OBJS)
-
-realclean:;	@rm -f $(OBJS)
-		@rm -f core ruby *~ config.status Makefile
-.c.o:
-	$(CC) $(CFLAGS) $(CPPFLAGS) -c $<
-
-dbm.o:dbm.c
-	$(DBMCC) $(CFLAGS) $(CPPFLAGS) -c dbm.c
-
-alloca.o: missing/alloca.c
-	$(CC) -I. $(CFLAGS) $(CPPFLAGS) -c missing/alloca.c
-
-memmove.o: missing/memmove.c
-	$(CC) $(CFLAGS) $(CPPFLAGS) -c missing/memmove.c
-
-mkdir.o: missing/mkdir.c
-	$(CC) $(CFLAGS) $(CPPFLAGS) -c missing/mkdir.c
-
-strerror.o: missing/strerror.c
-	$(CC) $(CFLAGS) $(CPPFLAGS) -c missing/strerror.c
-
-strdup.o: missing/strdup.c
-	$(CC) $(CFLAGS) $(CPPFLAGS) -c missing/strdup.c
-
-strftime.o: missing/strftime.c
-	$(CC) -I. $(CFLAGS) $(CPPFLAGS) -c missing/strftime.c
-
-strstr.o: missing/strstr.c
-	$(CC) $(CFLAGS) $(CPPFLAGS) -c missing/strstr.c
-
-strtol.o: missing/strtol.c
-	$(CC) $(CFLAGS) $(CPPFLAGS) -c missing/strtol.c
-
-strtoul.o: missing/strtoul.c
-	$(CC) $(CFLAGS) $(CPPFLAGS) -c missing/strtoul.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 ident.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 env.h node.h st.h
-compar.o: compar.c ruby.h config.h defines.h
-dbm.o: dbm.c ruby.h config.h defines.h
-dict.o: dict.c ruby.h config.h defines.h st.h
-dir.o: dir.c ruby.h config.h defines.h
-dln.o: dln.c defines.h dln.h
-enum.o: enum.c ruby.h config.h defines.h
-error.o: error.c ruby.h config.h defines.h env.h
-etc.o: etc.c ruby.h config.h defines.h
-eval.o: eval.c ruby.h config.h defines.h ident.h env.h node.h st.h
-file.o: file.c ruby.h config.h defines.h io.h
-fnmatch.o: fnmatch.c fnmatch.h
-gc.o: gc.c ruby.h config.h defines.h env.h st.h
-glob.o: glob.c ruby.h config.h defines.h fnmatch.h
-gnuglob.o: gnuglob.c fnmatch.h
-inits.o: inits.c ruby.h config.h defines.h
-io.o: io.c ruby.h config.h defines.h io.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 env.h
-object.o: object.c ruby.h config.h defines.h env.h st.h
-pack.o: pack.c ruby.h config.h defines.h
-process.o: process.c ruby.h config.h defines.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 defines.h regex.h
-ruby.o: ruby.c ruby.h config.h defines.h re.h regex.h getopt.h
-socket.o: socket.c ruby.h config.h defines.h io.h
-sprintf.o: sprintf.c ruby.h config.h defines.h
-st.o: st.c 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 env.h
-time.o: time.c ruby.h config.h defines.h
-variable.o: variable.c ruby.h config.h defines.h env.h ident.h st.h
-version.o: version.c ruby.h config.h defines.h version.h
diff --git a/NEWS b/NEWS
new file mode 100644
index 0000000000..e1adb5115d
--- /dev/null
+++ b/NEWS
@@ -0,0 +1,826 @@
+# -*- rdoc -*-
+
+= NEWS for Ruby 2.7.0
+
+This document is a list of user visible feature changes made between
+releases 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. <tt>https://bugs.ruby-lang.org/issues/$FEATURE_OR_BUG_NUMBER</tt>).
+
+== Changes since the 2.6.0 release
+
+=== Language changes
+
+==== Pattern matching
+
+* Pattern matching is introduced as an experimental feature. [Feature #14912]
+
+    case [0, [1, 2, 3]]
+    in [a, [b, *c]]
+      p a #=> 0
+      p b #=> 1
+      p c #=> [2, 3]
+    end
+
+    case {a: 0, b: 1}
+    in {a: 0, x: 1}
+      :unreachable
+    in {a: 0, b: var}
+      p var #=> 1
+    end
+
+    case -1
+    in 0 then :unreachable
+    in 1 then :unreachable
+    end #=> NoMatchingPatternError
+
+    json = <<END
+    {
+      "name": "Alice",
+      "age": 30,
+      "children": [{ "name": "Bob", "age": 2 }]
+    }
+    END
+
+    JSON.parse(json, symbolize_names: true) in {name: "Alice", children: [{name: name, age: age}]}
+
+    p name #=> "Bob"
+    p age  #=> 2
+
+    JSON.parse(json, symbolize_names: true) in {name: "Alice", children: [{name: "Charlie", age: age}]}
+    #=> NoMatchingPatternError
+
+* See the following slides for more details:
+  * https://speakerdeck.com/k_tsj/pattern-matching-new-feature-in-ruby-2-dot-7
+  * Note that the slides are slightly obsolete.
+
+* The warning against pattern matching can be suppressed with
+  {-W:no-experimental option}[#label-Warning+option].
+
+==== The spec of keyword arguments is changed towards 3.0
+
+* Automatic conversion of keyword arguments and positional arguments is
+  deprecated, and conversion will be removed in Ruby 3.  [Feature #14183]
+
+  * When a method call passes a Hash at the last argument, and when it
+    passes no keywords, and when the called method accepts keywords,
+    a warning is emitted.  To continue treating the hash as keywords,
+    add a double splat operator to avoid the warning and ensure
+    correct behavior in Ruby 3.
+
+      def foo(key: 42); end; foo({key: 42})   # warned
+      def foo(**kw);    end; foo({key: 42})   # warned
+      def foo(key: 42); end; foo(**{key: 42}) # OK
+      def foo(**kw);    end; foo(**{key: 42}) # OK
+
+  * When a method call passes keywords to a method that accepts keywords,
+    but it does not pass enough required positional arguments, the
+    keywords are treated as a final required positional argument, and a
+    warning is emitted.  Pass the argument as a hash instead of keywords
+    to avoid the warning and ensure correct behavior in Ruby 3.
+
+      def foo(h, **kw); end; foo(key: 42)      # warned
+      def foo(h, key: 42); end; foo(key: 42)   # warned
+      def foo(h, **kw); end; foo({key: 42})    # OK
+      def foo(h, key: 42); end; foo({key: 42}) # OK
+
+  * When a method accepts specific keywords but not a keyword splat, and
+    a hash or keywords splat is passed to the method that includes both
+    Symbol and non-Symbol keys, the hash will continue to be split, and
+    a warning will be emitted.  You will need to update the calling code
+    to pass separate hashes to ensure correct behavior in Ruby 3.
+
+      def foo(h={}, key: 42); end; foo("key" => 43, key: 42)   # warned
+      def foo(h={}, key: 42); end; foo({"key" => 43, key: 42}) # warned
+      def foo(h={}, key: 42); end; foo({"key" => 43}, key: 42) # OK
+
+  * If a method does not accept keywords, and is called with keywords,
+    the keywords are still treated as a positional hash, with no warning.
+    This behavior will continue to work in Ruby 3.
+
+      def foo(opt={});  end; foo( key: 42 )   # OK
+
+* Non-symbols are allowed as keyword argument keys if the method accepts
+  arbitrary keywords. [Feature #14183]
+
+  * Non-Symbol keys in a keyword arguments hash were prohibited in 2.6.0,
+    but are now allowed again.  [Bug #15658]
+
+      def foo(**kw); p kw; end; foo("str" => 1) #=> {"str"=>1}
+
+* <code>**nil</code> is allowed in method definitions to explicitly mark
+  that the method accepts no keywords. Calling such a method with keywords
+  will result in an ArgumentError. [Feature #14183]
+
+    def foo(h, **nil); end; foo(key: 1)       # ArgumentError
+    def foo(h, **nil); end; foo(**{key: 1})   # ArgumentError
+    def foo(h, **nil); end; foo("str" => 1)   # ArgumentError
+    def foo(h, **nil); end; foo({key: 1})     # OK
+    def foo(h, **nil); end; foo({"str" => 1}) # OK
+
+* Passing an empty keyword splat to a method that does not accept keywords
+  no longer passes an empty hash, unless the empty hash is necessary for
+  a required parameter, in which case a warning will be emitted.  Remove
+  the double splat to continue passing a positional hash.  [Feature #14183]
+
+    h = {}; def foo(*a) a end; foo(**h) # []
+    h = {}; def foo(a) a end; foo(**h)  # {} and warning
+    h = {}; def foo(*a) a end; foo(h)   # [{}]
+    h = {}; def foo(a) a end; foo(h)    # {}
+
+* Above warnings can be suppressed also with {-W:no-deprecated option}[#label-Warning+option].
+
+==== Numbered parameters
+
+* Numbered parameters as default block parameters are introduced.
+  [Feature #4475]
+
+    [1, 2, 10].map { _1.to_s(16) }    #=> ["1", "2", "a"]
+    [[1, 2], [3, 4]].map { _1 + _2 }  #=> [3, 7]
+
+  You can still define a local variable named +_1+ and so on,
+  and that is honored when present, but renders a warning.
+
+    _1 = 0            #=> warning: `_1' is reserved for numbered parameter; consider another name
+    [1].each { p _1 } # prints 0 instead of 1
+
+==== proc/lambda without block is deprecated
+
+* Proc.new and Kernel#proc with no block in a method called with a block is
+  warned now.
+
+    def foo
+      proc
+    end
+    foo { puts "Hello" } #=> warning: Capturing the given block using Kernel#proc is deprecated; use `&block` instead
+
+  This warning can be suppressed with {-W:no-deprecated option}[#label-Warning+option].
+
+* Kernel#lambda with no block in a method called with a block raises an exception.
+
+    def bar
+      lambda
+    end
+    bar { puts "Hello" } #=> tried to create Proc object without a block (ArgumentError)
+
+==== Other miscellaneous changes
+
+* A beginless range is experimentally introduced.  It might be useful
+  in +case+, new call-sequence of the <code>Comparable#clamp</code>,
+  constants and DSLs.  [Feature #14799]
+
+     ary[..3]  # identical to ary[0..3]
+
+     case RUBY_VERSION
+     when ..."2.4" then puts "EOL"
+     # ...
+     end
+
+     age.clamp(..100)
+
+     where(sales: ..100)
+
+* Setting <code>$;</code> to a non-nil value is warned now. [Feature #14240]
+  Use of it in String#split is warned too.
+  This warning can be suppressed with {-W:no-deprecated option}[#label-Warning+option].
+
+* Setting <code>$,</code> to a non-nil value is warned now. [Feature #14240]
+  Use of it in Array#join is warned too.
+  This warning can be suppressed with {-W:no-deprecated option}[#label-Warning+option].
+
+* Quoted here-document identifiers must end within the same line.
+
+     <<"EOS
+     " # This had been warned since 2.4; Now it raises a SyntaxError
+     EOS
+
+* The flip-flop syntax deprecation is reverted. [Feature #5400]
+
+* Comment lines can be placed between fluent dot now.
+
+    foo
+      # .bar
+      .baz # => foo.baz
+
+* Calling a private method with a literal +self+ as the receiver
+  is now allowed. [Feature #11297] [Feature #16123]
+
+* Modifier rescue now operates the same for multiple assignment as single
+  assignment. [Bug #8279]
+
+    a, b = raise rescue [1, 2]
+    # Previously parsed as: (a, b = raise) rescue [1, 2]
+    # Now parsed as:         a, b = (raise rescue [1, 2])
+
+* +yield+ in singleton class syntax is warned and will be deprecated later. [Feature #15575].
+
+   def foo
+     class << Object.new
+       yield #=> warning: `yield' in class syntax will not be supported from Ruby 3.0. [Feature #15575]
+     end
+   end
+   foo { p :ok }
+
+  This warning can be suppressed with {-W:no-deprecated option}[#label-Warning+option].
+
+* Argument forwarding by <code>(...)</code> is introduced. [Feature #16253]
+
+    def foo(...)
+      bar(...)
+    end
+
+  All arguments to +foo+ are forwarded to +bar+, including keyword and
+  block arguments.
+  Note that the parentheses are mandatory.  <code>bar ...</code> is parsed
+  as an endless range.
+
+* Access and setting of <code>$SAFE</code> is now always warned. <code>$SAFE</code>
+  will become a normal global variable in Ruby 3.0. [Feature #16131]
+
+* <code>Object#{taint,untaint,trust,untrust}</code> and related functions in the C-API
+  no longer have an effect (all objects are always considered untainted), and are now
+  warned in verbose mode. This warning will be disabled even in non-verbose mode in
+  Ruby 3.0, and the methods and C functions will be removed in Ruby 3.2. [Feature #16131]
+
+* Refinements take place at Object#method and Module#instance_method. [Feature #15373]
+
+=== Command line options
+
+==== Warning option
+
+The +-W+ option has been extended with a following +:+, to manage categorized
+warnings.  [Feature #16345] [Feature #16420]
+
+* To suppress deprecation warnings:
+
+    $ ruby -e '$; = ""'
+    -e:1: warning: `$;' is deprecated
+
+    $ ruby -W:no-deprecated -e '$; = //'
+
+* It works with the +RUBYOPT+ environment variable:
+
+    $ RUBYOPT=-W:no-deprecated ruby -e '$; = //'
+
+* To suppress experimental feature warnings:
+
+    $ ruby -e '0 in a'
+    -e:1: warning: Pattern matching is experimental, and the behavior may change in future versions of Ruby!
+
+    $ ruby -W:no-experimental -e '0 in a'
+
+* To suppress both by using +RUBYOPT+, set space separated values:
+
+    $ RUBYOPT='-W:no-deprecated -W:no-experimental' ruby -e '($; = "") in a'
+
+See also Warning in {Core classes updates}[#label-Core+classes+updates+-28outstanding+ones+only-29].
+
+=== Core classes updates (outstanding ones only)
+
+Array::
+
+  New methods::
+
+    * Added Array#intersection. [Feature #16155]
+
+    * Added Array#minmax, with a faster implementation than Enumerable#minmax. [Bug #15929]
+
+Comparable::
+
+  Modified method::
+
+    * Comparable#clamp now accepts a Range argument. [Feature #14784]
+
+        -1.clamp(0..2) #=> 0
+         1.clamp(0..2) #=> 1
+         3.clamp(0..2) #=> 2
+        # With beginless and endless ranges:
+        -1.clamp(0..)  #=> 0
+         3.clamp(..2)  #=> 2
+
+
+Complex::
+
+  New method::
+
+    * Added Complex#<=>.
+      So <code>0 <=> 0i</code> will not raise NoMethodError. [Bug #15857]
+
+Dir::
+
+  Modified methods::
+
+    * Dir.glob and Dir.[] no longer allow NUL-separated glob pattern.
+      Use Array instead.  [Feature #14643]
+
+Encoding::
+
+  New encoding::
+
+    * Added new encoding CESU-8. [Feature #15931]
+
+Enumerable::
+
+  New methods::
+
+    * Added Enumerable#filter_map.  [Feature #15323]
+
+        [1, 2, 3].filter_map {|x| x.odd? ? x.to_s : nil } #=> ["1", "3"]
+
+    * Added Enumerable#tally.  [Feature #11076]
+
+        ["A", "B", "C", "B", "A"].tally #=> {"A"=>2, "B"=>2, "C"=>1}
+
+Enumerator::
+
+  New methods::
+
+    * Added Enumerator.produce to generate an Enumerator from any custom
+      data transformation.  [Feature #14781]
+
+        require "date"
+        dates = Enumerator.produce(Date.today, &:succ) #=> infinite sequence of dates
+        dates.detect(&:tuesday?) #=> next Tuesday
+
+    * Added Enumerator::Lazy#eager that generates a non-lazy enumerator
+      from a lazy enumerator.  [Feature #15901]
+
+        a = %w(foo bar baz)
+        e = a.lazy.map {|x| x.upcase }.map {|x| x + "!" }.eager
+        p e.class               #=> Enumerator
+        p e.map {|x| x + "?" }  #=> ["FOO!?", "BAR!?", "BAZ!?"]
+
+    * Added Enumerator::Yielder#to_proc so that a Yielder object
+      can be directly passed to another method as a block
+      argument.  [Feature #15618]
+
+Fiber::
+
+  New method::
+
+    * Added Fiber#raise that behaves like Fiber#resume but raises an
+      exception on the resumed fiber.  [Feature #10344]
+
+File::
+
+  Modified method::
+
+    * File.extname now returns a dot string for names ending with a dot on
+      non-Windows platforms.  [Bug #15267]
+
+          File.extname("foo.") #=> "."
+
+FrozenError::
+
+  New method::
+
+    * Added FrozenError#receiver to return the frozen object on which
+      modification was attempted.  To set this object when raising
+      FrozenError in Ruby code, FrozenError.new accepts a +:receiver+
+      option.  [Feature #15751]
+
+GC::
+
+  New method::
+
+    * Added GC.compact method for compacting the heap.
+      This function compacts live objects in the heap so that fewer pages may
+      be used, and the heap may be more CoW (copy-on-write) friendly. [Feature #15626]
+
+      Details on the algorithm and caveats can be found here:
+      https://bugs.ruby-lang.org/issues/15626
+
+IO::
+
+  New method::
+
+    * Added IO#set_encoding_by_bom to check the BOM and set the external
+      encoding.  [Bug #15210]
+
+Integer::
+
+  Modified method::
+
+    * Integer#[] now supports range operations.  [Feature #8842]
+
+         0b01001101[2, 4]  #=> 0b0011
+         0b01001100[2..5]  #=> 0b0011
+         0b01001100[2...6] #=> 0b0011
+         #   ^^^^
+
+Method::
+
+  Modified method::
+
+    * Method#inspect shows more information. [Feature #14145]
+
+Module::
+
+  New methods::
+
+    * Added Module#const_source_location to retrieve the location where a
+      constant is defined.  [Feature #10771]
+
+    * Added Module#ruby2_keywords for marking a method as passing keyword
+      arguments through a regular argument splat, useful when delegating
+      all arguments to another method in a way that can be backwards
+      compatible with older Ruby versions.  [Bug #16154]
+
+  Modified methods::
+
+    * Module#autoload? now takes an +inherit+ optional argument, like
+      Module#const_defined?.  [Feature #15777]
+
+    * Module#name now always returns a frozen String. The returned String is
+      always the same for a given Module. This change is
+      experimental. [Feature #16150]
+
+NilClass / TrueClass / FalseClass::
+
+  Modified methods::
+
+    * NilClass#to_s, TrueClass#to_s, and FalseClass#to_s now always return a
+      frozen String. The returned String is always the same for each of these
+      values. This change is experimental. [Feature #16150]
+
+ObjectSpace::WeakMap::
+
+  Modified method::
+
+    * ObjectSpace::WeakMap#[]= now accepts special objects as either key or
+      values.  [Feature #16035]
+
+Proc::
+
+  New method::
+
+    * Added Proc#ruby2_keywords for marking the proc as passing keyword
+      arguments through a regular argument splat, useful when delegating
+      all arguments to another method or proc in a way that can be backwards
+      compatible with older Ruby versions.  [Feature #16404]
+
+Range::
+
+  New method::
+
+    * Added Range#minmax, with a faster implementation than Enumerable#minmax.
+      It returns a maximum that now corresponds to Range#max. [Bug #15807]
+
+  Modified method::
+
+    * Range#=== now uses Range#cover? for String arguments, too (in Ruby 2.6, it was
+      changed from Range#include? for all types except strings). [Bug #15449]
+
+
+RubyVM::
+
+  Removed method::
+
+    * +RubyVM.resolve_feature_path+ moved to
+      <code>$LOAD_PATH.resolve_feature_path</code>.  [Feature #15903] [Feature #15230]
+
+String::
+
+  Unicode::
+
+    * Update Unicode version and Emoji version from 11.0.0 to
+      12.0.0.  [Feature #15321]
+
+    * Update Unicode version to 12.1.0, adding support for
+      U+32FF SQUARE ERA NAME REIWA.  [Feature #15195]
+
+    * Update Unicode Emoji version to 12.1. [Feature #16272]
+
+Symbol::
+
+  New methods::
+
+    * Added Symbol#start_with? and Symbol#end_with? methods.  [Feature #16348]
+
+Time::
+
+  New methods::
+
+    * Added Time#ceil method.  [Feature #15772]
+
+    * Added Time#floor method.  [Feature #15653]
+
+  Modified method::
+
+    * Time#inspect is separated from Time#to_s and it shows
+      the time's sub second.  [Feature #15958]
+
+UnboundMethod::
+
+  New method::
+
+    * Added UnboundMethod#bind_call method.  [Feature #15955]
+
+      <code>umethod.bind_call(obj, ...)</code> is semantically equivalent
+      to <code>umethod.bind(obj).call(...)</code>.  This idiom is used in
+      some libraries to call a method that is overridden.  The added
+      method does the same without allocation of an intermediate Method
+      object.
+
+          class Foo
+            def add_1(x)
+              x + 1
+            end
+          end
+          class Bar < Foo
+            def add_1(x) # override
+              x + 2
+            end
+          end
+
+          obj = Bar.new
+          p obj.add_1(1) #=> 3
+          p Foo.instance_method(:add_1).bind(obj).call(1) #=> 2
+          p Foo.instance_method(:add_1).bind_call(obj, 1) #=> 2
+
+Warning::
+
+  New methods::
+
+    * Added Warning.[] and Warning.[]= to manage emitting/suppressing
+      some categories of warnings.  [Feature #16345] [Feature #16420]
+
+$LOAD_PATH::
+
+  New method::
+
+    * Added <code>$LOAD_PATH.resolve_feature_path</code>.  [Feature #15903] [Feature #15230]
+
+=== Stdlib updates (outstanding ones only)
+
+Bundler::
+
+  * Upgrade to Bundler 2.1.2.
+    See https://github.com/bundler/bundler/releases/tag/v2.1.2
+
+CGI::
+
+  * CGI.escapeHTML becomes 2~5x faster when there is at least one escaped character.
+    See https://github.com/ruby/ruby/pull/2226
+
+CSV::
+
+  * Upgrade to 3.1.2.
+    See https://github.com/ruby/csv/blob/master/NEWS.md.
+
+Date::
+
+  * Date.jisx0301, Date#jisx0301, and Date.parse support the new Japanese
+    era.  [Feature #15742]
+
+Delegator::
+
+  * Object#DelegateClass accepts a block and module_evals it in the context
+    of the returned class, similar to Class.new and Struct.new.
+
+ERB::
+
+  * Prohibit marshaling ERB instance.
+
+IRB::
+
+  * Introduce syntax highlighting inspired by the Pry gem to Binding#irb
+    source lines, REPL input, and inspect output of some core-class objects.
+
+  * Introduce multiline editing mode provided by Reline.
+
+  * Show documentation when completion.
+
+  * Enable auto indent and save/load history by default.
+
+JSON::
+
+  * Upgrade to 2.3.0.
+
+Net::FTP::
+
+  * Add Net::FTP#features to check available features, and Net::FTP#option to
+    enable/disable each of them.  [Feature #15964]
+
+Net::HTTP::
+
+  * Add +ipaddr+ optional parameter to Net::HTTP#start to replace the address for
+    the TCP/IP connection. [Feature #5180]
+
+Net::IMAP::
+
+  * Add Server Name Indication (SNI) support.  [Feature #15594]
+
+open-uri::
+
+  * Warn open-uri's "open" method at Kernel.
+    Use URI.open instead.  [Misc #15893]
+
+  * The default charset of "text/*" media type is UTF-8 instead of
+    ISO-8859-1.  [Bug #15933]
+
+OptionParser::
+
+  * Now show "Did you mean?" for unknown options.  [Feature #16256]
+
+    test.rb:
+
+      require "optparse"
+      OptionParser.new do |opts|
+        opts.on("-f", "--foo", "foo") {|v| }
+        opts.on("-b", "--bar", "bar") {|v| }
+        opts.on("-c", "--baz", "baz") {|v| }
+      end.parse!
+
+    example:
+
+      $ ruby test.rb --baa
+      Traceback (most recent call last):
+      test.rb:7:in `<main>': invalid option: --baa (OptionParser::InvalidOption)
+      Did you mean?  baz
+                     bar
+
+Pathname::
+
+  * Pathname.glob now delegates 3 arguments to Dir.glob
+    to accept +base+ keyword. [Feature #14405]
+
+Racc::
+
+  * Merge 1.4.15 from upstream repository and added cli of racc.
+
+Reline::
+
+  * New stdlib that is compatible with the readline stdlib but is
+    implemented in pure Ruby. It also provides a multiline editing mode.
+
+REXML::
+
+  * Upgrade to 3.2.3.
+    See https://github.com/ruby/rexml/blob/master/NEWS.md.
+
+RSS::
+
+  * Upgrade to RSS 0.2.8.
+    See https://github.com/ruby/rss/blob/master/NEWS.md.
+
+RubyGems::
+
+  * Upgrade to RubyGems 3.1.2.
+    * https://github.com/rubygems/rubygems/releases/tag/v3.1.0
+    * https://github.com/rubygems/rubygems/releases/tag/v3.1.1
+    * https://github.com/rubygems/rubygems/releases/tag/v3.1.2
+
+StringScanner::
+
+  * Upgrade to 1.0.3.
+    See https://github.com/ruby/strscan/blob/master/NEWS.md.
+
+=== Compatibility issues (excluding feature bug fixes)
+
+* The following libraries are no longer bundled gems.
+  Install corresponding gems to use these features.
+  * CMath (cmath gem)
+  * Scanf (scanf gem)
+  * Shell (shell gem)
+  * Synchronizer (sync gem)
+  * ThreadsWait (thwait gem)
+  * E2MM (e2mmap gem)
+
+Proc::
+  * The Proc#to_s format was changed. [Feature #16101]
+
+Range::
+  * Range#minmax used to iterate on the range to determine the maximum.
+    It now uses the same algorithm as Range#max. In rare cases (e.g.
+    ranges of Floats or Strings), this may yield different results. [Bug #15807]
+
+=== Stdlib compatibility issues (excluding feature bug fixes)
+
+* Promote stdlib to default gems
+  * The following default gems were published on rubygems.org
+    * benchmark
+    * cgi
+    * delegate
+    * getoptlong
+    * net-pop
+    * net-smtp
+    * open3
+    * pstore
+    * readline
+    * readline-ext
+    * singleton
+  * The following default gems were only promoted at ruby-core,
+    but not yet published on rubygems.org.
+    * monitor
+    * observer
+    * timeout
+    * tracer
+    * uri
+    * yaml
+* The <tt>did_you_mean</tt> gem has been promoted up to a default gem from a bundled gem
+
+pathname::
+
+  * Kernel#Pathname when called with a Pathname argument now returns
+    the argument instead of creating a new Pathname. This is more
+    similar to other Kernel methods, but can break code that modifies
+    the return value and expects the argument not to be modified.
+
+profile.rb, Profiler__::
+
+  * Removed from standard library. It was unmaintained since Ruby 2.0.0.
+
+=== C API updates
+
+* Many <code>*_kw</code> functions have been added for setting whether
+  the final argument being passed should be treated as keywords. You
+  may need to switch to these functions to avoid keyword argument
+  separation warnings, and to ensure correct behavior in Ruby 3.
+
+* The <code>:</code> character in rb_scan_args format string is now
+  treated as keyword arguments. Passing a positional hash instead of
+  keyword arguments will emit a deprecation warning.
+
+* C API declarations with +ANYARGS+ are changed not to use +ANYARGS+.
+  See https://github.com/ruby/ruby/pull/2404
+
+=== Implementation improvements
+
+Fiber::
+
+  * Allow selecting different coroutine implementations by using
+    +--with-coroutine=+, e.g.
+
+         $ ./configure --with-coroutine=ucontext
+         $ ./configure --with-coroutine=copy
+
+  * Replace previous stack cache with fiber pool cache. The fiber pool
+    allocates many stacks in a single memory region. Stack allocation
+    becomes O(log N) and fiber creation is amortized O(1). Around 10x
+    performance improvement was measured in micro-benchmarks.
+    https://github.com/ruby/ruby/pull/2224
+
+File::
+  * File.realpath now uses realpath(3) on many platforms, which can
+    significantly improve performance. [Feature #15797]
+
+Hash::
+  * Change data structure of small Hash objects. [Feature #15602]
+
+Monitor::
+  * Monitor class is written in C-extension. [Feature #16255]
+
+Thread::
+
+  * VM stack memory allocation is now combined with native thread stack,
+    improving thread allocation performance and reducing allocation related
+    failures. Around 10x performance improvement was measured in micro-benchmarks.
+
+JIT::
+
+  * JIT-ed code is recompiled to less-optimized code when an optimization assumption is invalidated.
+
+  * Method inlining is performed when a method is considered as pure.
+    This optimization is still experimental and many methods are NOT considered as pure yet.
+
+  * The default value of +--jit-max-cache+ is changed from 1,000 to 100.
+
+  * The default value of +--jit-min-calls+ is changed from 5 to 10,000.
+
+RubyVM::
+
+  * Per-call-site method cache, which has been there since around 1.9, was
+    improved: cache hit rate raised from 89% to 94%.
+    See https://github.com/ruby/ruby/pull/2583
+
+RubyVM::InstructionSequence::
+
+  * RubyVM::InstructionSequence#to_binary method generates compiled binary.
+    The binary size is reduced. [Feature #16163]
+
+=== Miscellaneous changes
+
+* Support for IA64 architecture has been removed. Hardware for testing was
+  difficult to find, native fiber code is difficult to implement, and it added
+  non-trivial complexity to the interpreter. [Feature #15894]
+
+* Require compilers to support C99. [Misc #15347]
+
+  * Details of our dialect: https://bugs.ruby-lang.org/projects/ruby-trunk/wiki/C99
+
+* Ruby's upstream repository is changed from Subversion to Git.
+
+  * https://git.ruby-lang.org/ruby.git
+
+  * RUBY_REVISION class is changed from Integer to String.
+
+  * RUBY_DESCRIPTION includes Git revision instead of Subversion's one.
+
+* Support built-in methods in Ruby with the <code>_\_builtin_</code> syntax. [Feature #16254]
+
+  Some methods are defined in *.rb (such as trace_point.rb).
+  For example, it is easy to define a method which accepts keyword arguments.
diff --git a/README b/README
deleted file mode 100644
index 9dc79e8e26..0000000000
--- a/README
+++ /dev/null
@@ -1,73 +0,0 @@
-.\" README -  -*- Text -*- created at: Wed Aug  3 11:57:36 JST 1994
-
-¥³¥ó¥Ñ¥¤¥ë¡¦¥¤¥ó¥¹¥È¡¼¥ë
-
-  1. configure¤ò¼Â¹Ô¤·¤ÆMakefile¤òÀ¸À®¤¹¤ë.
-  2. (ɬÍפʤé¤Ð)defines.h¤òÊÔ½¸¤¹¤ë.
-  3. make¤ò¼Â¹Ô¤·¤Æ¥³¥ó¥Ñ¥¤¥ë¤¹¤ë
-  4. make install
-
-  ¤â¤·, ¥³¥ó¥Ñ¥¤¥ë»þ¤Ë¥¨¥é¡¼¤¬È¯À¸¤·¤¿¾ì¹ç¤Ë¤Ï¥¨¥é¡¼¤Î¥í¥°¤È¥Þ
-  ¥·¥ó, OS¤Î¼ïÎà¤ò´Þ¤à¤Ç¤­¤ë¤À¤±¾Ü¤·¤¤¥ì¥Ý¡¼¥È¤òºî¼Ô¤ËÁ÷¤Ã¤Æ¤¤
-  ¤¿¤À¤­¤¿¤¤.
-
-µ¡Ç½ÄɲÃ
-
-  C¥³¡¼¥É¤ò½ñ¤¯¤³¤È¤Ë¤è¤Ã¤Æ, ´Êñ¤Ëruby¤Ëµ¡Ç½¤òÄɲäǤ­¤ë. 
-  ¤½¤Î¤ª¤ª¤Þ¤«¤Ê¼ê½ç¤Ï°Ê²¼¤ÎÄ̤ê¤Ç¤¢¤ë.
-
-  * ´Ø¿ôŪ¥á¥½¥Ã¥É¤òÄɲ乤ë¾ì¹ç
-
-    (1) C¤Ç´Ø¿ô¤ò½ñ¤¯
-    (2) rb_define_method()¤Ç¥«¡¼¥Í¥ë¥¯¥é¥¹¤Î¥á¥½¥Ã¥É¤È¤·¤Æ´Ø
-	¿ô¤òruby¤ËÅÐÏ¿¤¹¤ë´Ø¿ô¤ò½ñ¤¯
-    (3) init.c¤òÊÔ½¸¤·¤Æ, ÅÐÏ¿¤¹¤ë´Ø¿ô¤ò¸Æ¤Ó½Ð¤¹
-
-  * ¥¯¥é¥¹¤òÄɲ乤ë¾ì¹ç
-
-    (1) ¥¯¥é¥¹¤òÀ߷פ¹¤ë
-    (2) ¥á¥½¥Ã¥É¤òC¤Çµ­½Ò¤¹¤ë
-    (3) rb_define_class()¤Ç¥¯¥é¥¹¤òÀ¸À®¤¹¤ë¥³¡¼¥É¤ò½ñ¤¯
-    (4) rb_define_method()¤Ç¥á¥½¥Ã¥É¤òÅÐÏ¿¤¹¤ë¥³¡¼¥É¤ò½ñ¤¯
-    (5) init.c¤òÊÔ½¸¤·¤Æ, ½é´ü²½¤¹¤ë´Ø¿ô¤ò¸Æ¤Ó½Ð¤¹
-
-  ¾Ü¤·¤¯¤ÏC-IF¤ò»²¾È.
-
-°Ü¿¢
-
-  UNIX¤Ç¤¢¤ì¤Ðconfigure¤¬¤Û¤È¤ó¤É¤Îº¹°Û¤òµÛ¼ý¤·¤Æ¤¯¤ì¤ë¤Ï¤º
-  ¤À¤¬, »×¤ï¤Ì¸«Íî¤È¤·¤¬¤¢¤Ã¤¿¾ì¹ç(¤¢¤ë¤Ë°ã¤¤¤Ê¤¤), ºî¼Ô¤Ë¥ì
-  ¥Ý¡¼¥È¤¹¤ì¤Ð, ²ò·è¤Ç¤­¤ë¤«¤âÃΤì¤Ê¤¤.
-
-  ¥¢¡¼¥¯¥Æ¥¯¥Á¥ã¤Ë¤â¤Ã¤È¤â°Í¸¤¹¤ë¤Î¤ÏGCÉô¤Ç¤¢¤ë. ruby¤ÎGC¤Ï
-  ÂоݤΥ¢¡¼¥­¥Æ¥¯¥Á¥ã¤¬setjmp()¤Ë¤è¤Ã¤Æ, Á´¤Æ¤Î¥ì¥¸¥¹¥¿¤ò 
-  jmp_buf¤Ë³ÊǼ¤¹¤ë¤³¤È¤È, jmp_buf¤È¥¹¥¿¥Ã¥¯¤¬32bit¥¢¥é¥¤¥ó
-  ¥á¥ó¥È¤µ¤ì¤Æ¤¤¤ë¤³¤È¤ò²¾Äꤷ¤Æ¤¤¤ë. Á°¼Ô¤¬¿¿¼Â¤Ç¤Ê¤¤¾ì¹ç¤Î
-  °Ü¿¢¤Ïº¤Æñ¤ò¶Ë¤á¤ë¤À¤í¤¦. ¸å¼Ô¤Ï³ä¤È´Êñ¤Ë²ò·è¤Ç¤­¤ë. gc.c
-  ¤Î¥¹¥¿¥Ã¥¯¤ò¥Þ¡¼¥¯¤¹¤ëÉôʬ¤Ë¥¢¥é¥¤¥ó¥á¥ó¥È¤Î¥Ð¥¤¥È¿ô¤À¤±¤º
-  ¤é¤·¤Æ¥Þ¡¼¥¯¤¹¤ë¥³¡¼¥É¤òÄɲ乤ë¤À¤±¤ÇºÑ¤à.
-
-  sparc°Ê³°¤Î¥ì¥¸¥¹¥¿¥¦¥£¥ó¥É¥¦¤ò»ý¤ÄCPU¤Ç¤Ï, ¥ì¥¸¥¹¥¿¥¦¥£¥ó
-  ¥É¥¦¤ò¥Õ¥é¥Ã¥·¥å¤¹¤ë¥³¡¼¥É¤òÄɲ乤ëɬÍפ¬¤¢¤ë¤«¤âÃΤì¤Ê¤¤.
-
-ÇÛÉÛ¾ò·ï
-
-  Ruby¤ÏºÇ½ªÅª¤Ë¤ÏGNU Public License¤Ë¤·¤¿¤¬¤Ã¤¿¾ò·ï¤ÇÇÛÉÛ¤µ
-  ¤ì¤ëͽÄê¤À¤¬, ¸½»þÅÀ¤Ç¤Ï°Ê²¼¤Î¾ò·ï¤ÇÇÛÉÛ¤¹¤ë.
-
-  * ¹¹¿·
-
-    ¤¤¤«¤Ê¤ëÌÜŪ¤Ç¤¢¤ì¼«Í³¤Ç¤¢¤ë. ¤¿¤À¤·, ¥Ð¥°½¤Àµ¤Ïºî¼Ô¤Ø¤Î
-    ¥Õ¥£¡¼¥É¥Ð¥Ã¥¯¤ò´üÂÔ¤¹¤ë(¶¯À©¤Ç¤Ï¤Ê¤¤)
-
-  * ¾¤Î¥×¥í¥°¥é¥à¤Ø¤Î°úÍÑ
-
-    ¤¤¤«¤Ê¤ëÌÜŪ¤Ç¤¢¤ì¼«Í³¤Ç¤¢¤ë. ¤¿¤À¤·, ÇÛÉÛ¤·¤¿¥³¡¼¥É¤Ë´Þ
-    ¤Þ¤ì¤ë¾¤Îºî¼Ô¤Ë¤è¤ë¥³¡¼¥É¤Ï, ¤½¤ì¤¾¤ì¤Îºî¼Ô¤Î°Õ¸þ¤Ë¤è¤ë
-    À©¸Â¤¬²Ã¤¨¤é¤ì¤ë.
-
-  * ºÆÇÛÉÛ
-
-    ¶Ø»ß¤¹¤ë. Æþ¼ê¤·¤¿¤¤¿Í¤Ïºî¼Ô¤ËľÀÜÏ¢Íí¤ò¤È¤ë¤³¤È. ¤³¤ì¤Ï
-    Ruby¤Î¸À¸ì»ÅÍͤ¬ÉÔ°ÂÄê¤Ê¾õÂ֤Τޤ޹­¤¯Î®ÉÛ¤¹¤ë¤Î¤òÀ©¸Â¤¹
-    ¤ë¤¿¤á¤Ç¤¢¤ê, ¸À¸ì»ÅÍͤ¬°ÂÄꤷ¤¿»þÅÀ¤ÇºÆÇÛÉÛ¼«Í³¤È¤¹¤ë.
diff --git a/README.EXT b/README.EXT
new file mode 100644
index 0000000000..48b8d964c4
--- /dev/null
+++ b/README.EXT
@@ -0,0 +1 @@
+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�移動����
diff --git a/README.ja.md b/README.ja.md
new file mode 100644
index 0000000000..4e1e6b9d87
--- /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)
+![](https://github.com/ruby/ruby/workflows/Cygwin/badge.svg)
+![](https://github.com/ruby/ruby/workflows/macOS/badge.svg)
+![](https://github.com/ruby/ruby/workflows/MJIT/badge.svg)
+![](https://github.com/ruby/ruby/workflows/Ubuntu/badge.svg)
+![](https://github.com/ruby/ruby/workflows/Windows/badge.svg)
+
+# Ruby��
+
+Ruby�シンプル��強力�オブジェクト指�スクリプト言語��． Ruby�純粋�オブジェクト指�言語���設計�れ��る��，
+オブジェクト指�プログラミングを手軽�行�事�出���．も��ん普通�手続�型�プログラミングも�能��．
+
+Ruby�テキスト処�関係�能力���優れ，Perl����ら�強力��．�ら�シンプル�文法�，
+例外処�やイテレータ���機構�よ��，より分�りや��プログラミング�出���．
+
+## Ruby�特長
+
+*   シンプル�文法
+*   普通�オブジェクト指�機能(クラス，メソッドコール��)
+*   特殊�オブジェクト指�機能(Mixin，特異メソッド��)
+*   演算�オー�ーロード
+*   例外処�機能
+*   イテレータ�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�ャ�よる)
+*   移�性�高�．多��Unix-like/POSIX互�プラットフォーム上�動������，Windows， macOS，
+    Haiku���上�も動� 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��方法を�むRuby�インストール方法�一覧�
+
+https://www.ruby-lang.org/ja/downloads/
+
+を�照������．
+
+### Git
+
+ミラーをGitHub�公開�����． 以下�コマンド�リ�ジトリを�得����．
+
+    $ git clone https://github.com/ruby/ruby.git
+
+他�ブラン��一覧�次�コマンド�見られ��．
+
+    $ git ls-remote https://github.com/ruby/ruby.git
+
+Rubyリ�ジトリ�本��master� https://git.ruby-lang.org/ruby.git ��り��．
+コミッタ���らを使���．
+
+### Subversion
+
+��Ruby��ージョン�ソースコード�次�コマンド��得����．
+
+    $ svn co https://svn.ruby-lang.org/repos/ruby/branches/ruby_2_6/ ruby
+
+他�開発中�ブラン��一覧�次�コマンド�見られ��．
+
+    $ svn ls https://svn.ruby-lang.org/repos/ruby/branches/
+
+
+## ホームページ
+
+Ruby�ホームページ�URL�
+
+https://www.ruby-lang.org/
+
+��．
+
+## メーリングリスト
+
+Ruby�メーリングリスト��り��．�加希望�方�
+
+mailto:ruby-list-request@ruby-lang.org
+
+��本文�
+
+    subscribe
+
+�書�����下��．
+
+Ruby開発者��メーリングリストも�り��．��ら��ruby��グ，将��仕様拡張��実装上��題����議論�れ����． �加希望�方�
+
+mailto:ruby-dev-request@ruby-lang.org
+
+��ruby-list��様�方法�メール������．
+
+Ruby拡張モジュール����話���ruby-extメーリングリスト�数学関係�話題����話���ruby-mathメーリングリスト�
+英語�ruby����話���ruby-talkメーリングリストも�り��．�加方法��れも����．
+
+## コンパイル・インストール
+
+以下�手順�行������．
+
+1.  も� `configure` ファイル�見��ら��，も��� `configure.ac` より��よ��ら， `autoconf` を実行��
+    新�� `configure` を生��る
+
+2.  `configure` を実行�� `Makefile` ��を生��る
+
+    環境�よ���デフォルト�Cコンパイラ用オプション�付���． `configure` オプション� `optflags=..`
+    `warnflags=..` 等�上書�����．
+
+3.  (必��ら�)`defines.h` を編集�る
+
+    多分，必�無������．
+
+4.  (必��ら�)`ext/Setup` ��的�リンク�る拡張モジュールを指定�る
+
+    `ext/Setup` �記述��モジュール��的�リンク�れ��．
+
+    ダイナミックローディングをサ�ート�����アーキテク�ャ�� `Setup` �1行目�「`option nodynamic`����行�コ
+    メントを外�必���り��．
+    ��，��アーキテク�ャ�拡張モジュールを利用�る����，�ら����的�リンクを����必���り��．
+
+5.  `make` を実行��コンパイル�る
+
+6.  `make check`�テストを行�．
+
+    「`check succeeded`��表示�れれ��功��．���テスト��功��も完璧���証�れ��る訳���り��ん．
+
+7.  `make install`
+
+    以下�ディレクトリを作��，���ファイルをインストー ル���．
+
+    *   `${DESTDIR}${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�API�ージョン�'*x.y.z*'��れ�，`${MAJOR}`�
+    '*x*'�，`${MINOR}`�'*y*'，`${TEENY}`�'*z*'��．
+
+    **注�**: API�ージョン� `teeny` �，Rubyプログラム��ージョン��異�る����り��．
+
+    `root` �作業�る必���る�も�れ��ん．
+
+
+も�，コンパイル時�エラー�発生��場���エラー�ログ�マシン，OS�種類を�む��る��詳��レ�ートを作者����下�る�他�方����も�り��．
+
+## 移�
+
+UNIX��れ� `configure` ���ん��差異を�����れる�����，���見�������場�(�る事�多�)，作者���
+��を報告�れ�，解決��る�能性��り��．
+
+アーキテク�ャ�も��も�存�る��GC部��．Ruby�GC�対象
+�アーキテク�ャ�`setjmp()`���`getcontext()`�よ��全��レジスタを `jmp_buf` や `ucontext_t`
+�格��る���， `jmp_buf` や `ucontext_t` �スタック�32bitアラインメント�れ��る��を仮定
+�����．特��者��立���場��対応��常�困難��ょ�． 後者�解決�比較的簡��， `gc.c` �スタックをマーク���る
+部分�アラインメント��イト数���ら��マーク�るコードを追加�る���済���．`defined(__mc68000__)`�括られ��
+る部分を�考�������．
+
+レジスタウィンドウを��CPU��，レジスタウィンドウをスタック�フラッシュ�るアセンブラコードを追加�る必���る�も�れ��ん．
+
+## �布�件
+
+[COPYING.ja](COPYING.ja) ファイルを�照������．
+
+## フィード�ック
+
+Ruby�関�る質�� 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/) ���Webサイト�投稿������．
+
+�グ報告� https://bugs.ruby-lang.org ���付�����．
+
+
+## 著者
+
+Ruby�オリジナル版�，1995年���も�ゆ�����よ��設計・開発�れ���．
+
+<mailto:matz@ruby-lang.org>
diff --git a/README.md b/README.md
new file mode 100644
index 0000000000..1e935095c6
--- /dev/null
+++ b/README.md
@@ -0,0 +1,176 @@
+[![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)
+![](https://github.com/ruby/ruby/workflows/Cygwin/badge.svg)
+![](https://github.com/ruby/ruby/workflows/macOS/badge.svg)
+![](https://github.com/ruby/ruby/workflows/MJIT/badge.svg)
+![](https://github.com/ruby/ruby/workflows/Ubuntu/badge.svg)
+![](https://github.com/ruby/ruby/workflows/Windows/badge.svg)
+
+# 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, Haiku, etc.) cf.
+    https://github.com/ruby/ruby/blob/master/doc/contributing.rdoc#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 `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.  Optionally, run `make update-gems` and `make extract-gems`.
+
+    If you want to install bundled gems, run `make update-gems` and
+    `make extract-gems` before running `make install`.
+
+9.  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 5dcb005f52..0000000000
--- a/ToDo
+++ /dev/null
@@ -1,12 +0,0 @@
-* Process Class
-* ¥¯¥é¥¹¥é¥¤¥Ö¥é¥ê¤Î¸«Ä¾¤·(UNIX°Í¸¤ò¸º¤é¤¹)
-* formatµ¡Ç½
-* here document
-* perl¤Î¤è¤¦¤Êsetuid check
-* tr¤«¤éBSD¥³¡¼¥É¤ò¼è¤ê½ü¤¯(¤Þ¤¿¤Ïcopyright¤ò¤Ï¤Ã¤­¤ê¤µ¤»¤ë)
-* ŬÀÚ¤Êsignal handling
-* dln¤ÎCOFFÂбþ(¤Þ¤¿¤ÏdlopenÂбþ)
-* ruby¤ÇÄêµÁ¤¹¤ëÊÑ¿ôhook¤Î¼Â¸½
-* write debugger for ruby
-* re-write regex code for speed
-* byte code interpretor
diff --git a/aclocal.m4 b/aclocal.m4
new file mode 100644
index 0000000000..ed7d14ef63
--- /dev/null
+++ b/aclocal.m4
@@ -0,0 +1,47 @@
+# generated automatically by aclocal 1.16.1 -*- Autoconf -*-
+
+# Copyright (C) 1996-2018 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_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..635194b96b
--- /dev/null
+++ b/addr2line.c
@@ -0,0 +1,2663 @@
+/**********************************************************************
+
+  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/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
+
+#ifdef HAVE_STDBOOL_H
+#include <stdbool.h>
+#else
+#include "missing/stdbool.h"
+#endif
+
+#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
+static void
+follow_debuglink(const char *debuglink, int num_traces, void **traces,
+		 obj_info_t **objp, line_info_t *lines, int offset)
+{
+    /* Ideally we should check 4 paths to follow gnu_debuglink,
+       but we handle only one case for now as this format is used
+       by some linux distributions. See GDB's info for detail. */
+    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);
+}
+#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;
+}
+
+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;
+    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_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);
+	}
+	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..4f6cf179ef
--- /dev/null
+++ b/addr2line.h
@@ -0,0 +1,21 @@
+/**********************************************************************
+
+  addr2line.h -
+
+  $Author$
+
+  Copyright (C) 2010 Shinichiro Hamaji
+
+**********************************************************************/
+
+#ifndef RUBY_ADDR2LINE_H
+#define RUBY_ADDR2LINE_H
+
+#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..bf10c97222
--- /dev/null
+++ b/appveyor.yml
@@ -0,0 +1,147 @@
+---
+version: '{build}'
+shallow_clone: true
+platform:
+  - x64
+branches:
+  except:
+    - trunk # mirrored from trunk. avoid doubly building on it
+environment:
+  ruby_version: "24-%Platform%"
+  zlib_version: "1.2.11"
+  matrix:
+    # to reduce time for finishing all jobs, run the slowest msys2 build first.
+    - build: msys2
+      APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2015
+      GEMS_FOR_TEST: "timezone tzinfo"
+    - 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% up incs
+    - del Makefile
+    - mkdir \usr\local\bin
+    - mkdir \usr\local\include
+    - mkdir \usr\local\lib
+    - curl -fsSL -o zlib%zlib_version:.=%.zip --retry 10 https://zlib.net/zlib%zlib_version:.=%.zip
+    - 7z x -o%APPVEYOR_BUILD_FOLDER%\ext\zlib zlib%zlib_version:.=%.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
+-
+  matrix:
+    only:
+      - build: msys2
+  install:
+    - ver
+    - chcp
+    - set /a JOBS=%NUMBER_OF_PROCESSORS%
+    - set MSYS_NO_PATHCONV=1
+    - SET MSYSTEM=%Platform:x86=32%
+    - SET MSYSTEM=%MSYSTEM:x=MINGW%
+    - SET MSYS2_ARCH=%Platform:x86=i686%
+    - SET MSYS2_ARCH=%MSYS2_ARCH:x64=x86_64%
+    - set MSYSTEM_PREFIX=/mingw64
+    - set MINGW_CHOST=%MSYS2_ARCH%-w64-mingw32
+    - SET ruby_path=C:\Ruby%ruby_version:-x86=%
+    - cd ..
+    - mkdir build
+    - mkdir install
+    - SET PATH=%ruby_path%\bin;C:\msys64\%MSYSTEM%\bin;C:\msys64\usr\bin;%PATH%
+    - ruby --version
+  build_script:
+    - pacman -Syd --noconfirm --noprogressbar --needed mingw-w64-x86_64-binutils mingw-w64-x86_64-isl mingw-w64-x86_64-libiconv mingw-w64-x86_64-mpc mingw-w64-x86_64-gcc-libs mingw-w64-x86_64-windows-default-manifest mingw-w64-x86_64-winpthreads mingw-w64-x86_64-gcc
+    # when fixed in MSYS2 / Mingw-w64, remove above and use normal code below
+    #- pacman -Sy --noconfirm --noprogressbar --needed mingw-w64-x86_64-toolchain
+    - pacman -S  --noconfirm --noprogressbar --needed mingw-w64-x86_64-gdbm mingw-w64-x86_64-gmp mingw-w64-x86_64-libffi mingw-w64-x86_64-libyaml mingw-w64-x86_64-openssl mingw-w64-x86_64-ragel mingw-w64-x86_64-readline mingw-w64-x86_64-zlib
+    - cd %APPVEYOR_BUILD_FOLDER%
+    - set CFLAGS=-march=%MSYS2_ARCH:_=-% -mtune=generic -O3 -pipe
+    - set CXXFLAGS=%CFLAGS%
+    - set CPPFLAGS=-D_FORTIFY_SOURCE=2 -D__USE_MINGW_ANSI_STDIO=1 -DFD_SETSIZE=2048
+    - set LDFLAGS=-pipe
+    - sh -c "autoreconf -fi"
+    - cd ..\build
+    - sh ../ruby/configure --disable-install-doc --prefix=/. --build=%MINGW_CHOST% --host=%MINGW_CHOST% --target=%MINGW_CHOST%
+    - mingw32-make %mflags% touch-unicode-files
+    - mingw32-make -j%JOBS% %UPDATE_UNICODE% up incs
+    - mingw32-make -j%JOBS% V=1
+    - mingw32-make DESTDIR=../install install-nodoc
+    - if not "%GEMS_FOR_TEST%" == "" ..\install\bin\gem install --no-document %GEMS_FOR_TEST%
+    - ..\install\bin\ruby.exe -v -ropenssl -e "puts 'Build    ' + OpenSSL::OPENSSL_VERSION, 'Runtime  ' + OpenSSL::OPENSSL_LIBRARY_VERSION"
+  test_script:
+    - mingw32-make test
+    - mingw32-make test-all TESTOPTS="--retry --job-status=normal --show-skip --timeout-scale=1.5 --excludes=../ruby/test/excludes/_appveyor -j %JOBS% --exclude win32ole --exclude test_open-uri"
+    # separately execute tests without -j which may crash worker with -j.
+    - mingw32-make test-all TESTOPTS="--retry --job-status=normal --show-skip --timeout-scale=1.5 --excludes=../ruby/test/excludes/_appveyor" TESTS="../ruby/test/win32ole ../ruby/test/open-uri/test_open-uri.rb"
+    - mingw32-make test-spec MSPECOPT=-fs # not using `-j` because sometimes `mspec -j` silently dies on Windows
+notifications:
+  # Using "Webhook" with templated body to skip notification on Pull Request
+  - provider: Webhook
+    method: POST
+    url:
+      secure: iMINHMS0nZabaDsxN9omRDsekxzVvAAzEq5ev7lN6vb+gUETT+rbDKLGxBxBpEpxlnPlLdzroIJ+DTKlwfJA8VkGawTn9EXNsucH0OkSf2M= # AppVeyor CI
+    body: >-
+      {{^isPullRequest}}
+        {
+          "attachments": [
+            {
+              "text": "Build <{{buildUrl}}|#{{buildVersion}}> (<{{commitUrl}}|{{commitId}}>) of {{repositoryName}}@{{branch}} by {{commitAuthor}} {{status}}",
+              "color": "{{#passed}}good{{/passed}}{{#failed}}danger{{/failed}}"
+            }
+          ],
+          "channel": "#alerts"
+        }
+      {{/isPullRequest}}
+    on_build_success: false
+    on_build_failure: true
+    on_build_status_changed: true
diff --git a/array.c b/array.c
index 895a6797ed..28bd8c866b 100644
--- a/array.c
+++ b/array.c
@@ -1,982 +1,7051 @@
-/************************************************
+/**********************************************************************
 
   array.c -
 
-  $Author: matz $
-  $Date: 1995/01/10 10:42:18 $
+  $Author$
   created at: Fri Aug  6 09:46:12 JST 1993
 
-  Copyright (C) 1994 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 "ruby/encoding.h"
+#include "ruby/util.h"
+#include "ruby/st.h"
+#include "probes.h"
+#include "id.h"
+#include "debug_counter.h"
+#include "transient_heap.h"
+#include "internal.h"
 
-#include "ruby.h"
+#if !ARRAY_DEBUG
+# define NDEBUG
+#endif
+#include "ruby_assert.h"
 
-VALUE C_Array;
+VALUE rb_cArray;
 
-VALUE rb_to_a();
+/* for OPTIMIZED_CMP: */
+#define id_cmp idCmp
 
 #define ARY_DEFAULT_SIZE 16
+#define ARY_MAX_SIZE (LONG_MAX / (int)sizeof(VALUE))
+#define SMALL_ARRAY_LEN 16
+
+static int
+should_be_T_ARRAY(VALUE ary)
+{
+    return RB_TYPE_P(ary, T_ARRAY);
+}
+
+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 (RARRAY_TRANSIENT_P(ary)) {
+        assert(rb_transient_heap_managed_ptr_p(RARRAY_CONST_PTR_TRANSIENT(ary)));
+    }
+
+    rb_transient_heap_verify();
+
+    return ary;
+}
+
+void
+rb_ary_verify(VALUE ary)
+{
+    ary_verify(ary);
+}
+#else
+#define ary_verify(ary) ((void)0)
+#endif
+
+VALUE *
+rb_ary_ptr_use_start(VALUE ary)
+{
+#if ARRAY_DEBUG
+    FL_SET_RAW(ary, RARRAY_PTR_IN_USE_FLAG);
+#endif
+    return (VALUE *)RARRAY_CONST_PTR_TRANSIENT(ary);
+}
+
+void
+rb_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;
+    }
+}
+
+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_memcpy0(VALUE ary, long beg, long argc, const VALUE *argv, VALUE buff_owner_ary)
+{
+    assert(!ARY_SHARED_P(buff_owner_ary));
+
+    if (argc > (int)(128/sizeof(VALUE)) /* is magic number (cache line size) */) {
+        rb_gc_writebarrier_remember(buff_owner_ary);
+        RARRAY_PTR_USE_TRANSIENT(ary, ptr, {
+            MEMCPY(ptr+beg, argv, VALUE, argc);
+        });
+    }
+    else {
+        int i;
+        RARRAY_PTR_USE_TRANSIENT(ary, ptr, {
+            for (i=0; i<argc; i++) {
+                RB_OBJ_WRITE(buff_owner_ary, &ptr[i+beg], argv[i]);
+            }
+        });
+    }
+}
+
+static void
+ary_memcpy(VALUE ary, long beg, long argc, const VALUE *argv)
+{
+    ary_memcpy0(ary, beg, argc, argv, ary);
+}
+
+static VALUE *
+ary_heap_alloc(VALUE ary, size_t capa)
+{
+    VALUE *ptr = rb_transient_heap_alloc(ary, sizeof(VALUE) * capa);
+
+    if (ptr != NULL) {
+        RARY_TRANSIENT_SET(ary);
+    }
+    else {
+        RARY_TRANSIENT_UNSET(ary);
+        ptr = ALLOC_N(VALUE, capa);
+    }
+
+    return ptr;
+}
+
+static void
+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
+rb_ary_increment_share(VALUE shared_root)
+{
+    long num = ARY_SHARED_ROOT_REFCNT(shared_root);
+    if (num >= 0) {
+        ARY_SET_SHARED_ROOT_REFCNT(shared_root, num + 1);
+    }
+    return shared_root;
+}
+
+static void
+rb_ary_set_shared(VALUE ary, VALUE shared_root)
+{
+    rb_ary_increment_share(shared_root);
+    FL_SET_SHARED(ary);
+    RB_DEBUG_COUNTER_INC(obj_ary_shared_create);
+    ARY_SET_SHARED(ary, shared_root);
+}
+
+static inline void
+rb_ary_modify_check(VALUE ary)
+{
+    rb_check_frozen(ary);
+    ary_verify(ary);
+}
+
+void
+rb_ary_modify(VALUE ary)
+{
+    rb_ary_modify_check(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);
+}
+
+static VALUE
+ary_ensure_room_for_push(VALUE ary, long add_len)
+{
+    long old_len = RARRAY_LEN(ary);
+    long new_len = old_len + add_len;
+    long capa;
+
+    if (old_len > ARY_MAX_SIZE - add_len) {
+	rb_raise(rb_eIndexError, "index %ld too big", new_len);
+    }
+    if (ARY_SHARED_P(ary)) {
+	if (new_len > RARRAY_EMBED_LEN_MAX) {
+            VALUE shared_root = ARY_SHARED_ROOT(ary);
+            if (ARY_SHARED_ROOT_OCCUPIED(shared_root)) {
+                if (ARY_HEAP_PTR(ary) - RARRAY_CONST_PTR_TRANSIENT(shared_root) + new_len <= RARRAY_LEN(shared_root)) {
+		    rb_ary_modify_check(ary);
+
+                    ary_verify(ary);
+                    ary_verify(shared_root);
+                    return shared_root;
+		}
+		else {
+		    /* if array is shared, then it is likely it participate in push/shift pattern */
+		    rb_ary_modify(ary);
+		    capa = ARY_CAPA(ary);
+		    if (new_len > capa - (capa >> 6)) {
+			ary_double_capa(ary, new_len);
+		    }
+                    ary_verify(ary);
+		    return ary;
+		}
+	    }
+	}
+        ary_verify(ary);
+        rb_ary_modify(ary);
+    }
+    else {
+	rb_ary_modify_check(ary);
+    }
+    capa = ARY_CAPA(ary);
+    if (new_len > capa) {
+	ary_double_capa(ary, new_len);
+    }
+
+    ary_verify(ary);
+    return ary;
+}
+
+/*
+ *  call-seq:
+ *      ary.freeze -> ary
+ *
+ *  Calls Object#freeze on +ary+ to prevent any further
+ *  modification. A RuntimeError will be raised if a modification
+ *  attempt is made.
+ *
+ */
 
 VALUE
-ary_new2(len)
+rb_ary_freeze(VALUE ary)
 {
-    NEWOBJ(ary, struct RArray);
-    OBJSETUP(ary, C_Array, T_ARRAY);
+    return rb_obj_freeze(ary);
+}
 
-    ary->len = 0;
-    ary->capa = len;
-    ary->ptr = ALLOC_N(VALUE, len);
+/* 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 len, i;
+    VALUE ary;
+    long i;
 
-    if (n < 0) {
-	Fail("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;
-    return (VALUE)ary;
+    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
-ary_new4(n, elts)
-    int n;
-    VALUE *elts;
+rb_ary_new_from_values(long n, const VALUE *elts)
 {
-    struct RArray* ary;
+    return rb_ary_tmp_new_from_values(rb_cArray, n, elts);
+}
 
-    ary = (struct RArray*)ary_new2(n);
-    MEMCPY(ary->ptr, elts, VALUE, n);
-    ary->len = n;
+VALUE
+rb_ary_tmp_new(long capa)
+{
+    VALUE ary = ary_new(0, capa);
+    rb_ary_transient_heap_evacuate(ary, TRUE);
+    return ary;
+}
 
-    return (VALUE)ary;
+VALUE
+rb_ary_tmp_new_fill(long capa)
+{
+    VALUE ary = ary_new(0, capa);
+    ary_memfill(ary, 0, capa, Qnil);
+    ARY_SET_LEN(ary, capa);
+    rb_ary_transient_heap_evacuate(ary, TRUE);
+    return ary;
+}
+
+void
+rb_ary_free(VALUE ary)
+{
+    if (ARY_OWNS_HEAP_P(ary)) {
+        if (USE_DEBUG_COUNTER &&
+            !ARY_SHARED_ROOT_P(ary) &&
+            ARY_HEAP_CAPA(ary) > RARRAY_LEN(ary)) {
+            RB_DEBUG_COUNTER_INC(obj_ary_extracapa);
+        }
+
+        if (RARRAY_TRANSIENT_P(ary)) {
+            RB_DEBUG_COUNTER_INC(obj_ary_transient);
+        }
+        else {
+            RB_DEBUG_COUNTER_INC(obj_ary_ptr);
+            ary_heap_free(ary);
+        }
+    }
+    else {
+        RB_DEBUG_COUNTER_INC(obj_ary_embed);
+    }
+
+    if (ARY_SHARED_P(ary)) {
+        RB_DEBUG_COUNTER_INC(obj_ary_shared);
+    }
+    if (ARY_SHARED_ROOT_P(ary) && ARY_SHARED_ROOT_OCCUPIED(ary)) {
+        RB_DEBUG_COUNTER_INC(obj_ary_shared_root_occupied);
+    }
+}
+
+RUBY_FUNC_EXPORTED size_t
+rb_ary_memsize(VALUE ary)
+{
+    if (ARY_OWNS_HEAP_P(ary)) {
+	return ARY_CAPA(ary) * sizeof(VALUE);
+    }
+    else {
+	return 0;
+    }
+}
+
+static inline void
+ary_discard(VALUE ary)
+{
+    rb_ary_free(ary);
+    RBASIC(ary)->flags |= RARRAY_EMBED_FLAG;
+    RBASIC(ary)->flags &= ~(RARRAY_EMBED_LEN_MASK | RARRAY_TRANSIENT_FLAG);
+}
+
+static VALUE
+ary_make_shared(VALUE ary)
+{
+    assert(!ARY_EMBED_P(ary));
+    ary_verify(ary);
+
+    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));
+
+        rb_ary_transient_heap_evacuate(ary, TRUE);
+        ptr = ARY_HEAP_PTR(ary);
+
+        FL_UNSET_EMBED(shared);
+	ARY_SET_LEN((VALUE)shared, capa);
+        ARY_SET_PTR((VALUE)shared, ptr);
+        ary_mem_clear((VALUE)shared, len, capa - len);
+	FL_SET_SHARED_ROOT(shared);
+        ARY_SET_SHARED_ROOT_REFCNT((VALUE)shared, 1);
+	FL_SET_SHARED(ary);
+        RB_DEBUG_COUNTER_INC(obj_ary_shared_create);
+	ARY_SET_SHARED(ary, (VALUE)shared);
+	OBJ_FREEZE(shared);
+
+        ary_verify((VALUE)shared);
+        ary_verify(ary);
+
+        return (VALUE)shared;
+    }
 }
 
 static VALUE
-Sary_new(class)
-    VALUE class;
+ary_make_substitution(VALUE ary)
 {
-    NEWOBJ(ary, struct RArray);
-    OBJSETUP(ary, class, T_ARRAY);
+    long len = RARRAY_LEN(ary);
 
-    ary->len = 0;
-    ary->capa = ARY_DEFAULT_SIZE;
-    ary->ptr = ALLOC_N(VALUE, ARY_DEFAULT_SIZE);
+    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));
+    }
+}
 
-    return (VALUE)ary;
+VALUE
+rb_assoc_new(VALUE car, VALUE cdr)
+{
+    return rb_ary_new3(2, car, cdr);
 }
 
+VALUE
+rb_to_array_type(VALUE ary)
+{
+    return rb_convert_type_with_id(ary, T_ARRAY, "Array", idTo_ary);
+}
+#define to_ary rb_to_array_type
+
+VALUE
+rb_check_array_type(VALUE ary)
+{
+    return rb_check_convert_type_with_id(ary, T_ARRAY, "Array", idTo_ary);
+}
+
+MJIT_FUNC_EXPORTED VALUE
+rb_check_to_array(VALUE ary)
+{
+    return rb_check_convert_type_with_id(ary, T_ARRAY, "Array", idTo_a);
+}
+
+/*
+ *  call-seq:
+ *     Array.try_convert(obj) -> array or nil
+ *
+ *  Tries to convert +obj+ into an array, using the +to_ary+ method.  Returns
+ *  the converted array or +nil+ if +obj+ cannot be converted.
+ *  This method can be used to check if an argument is an array.
+ *
+ *     Array.try_convert([1])   #=> [1]
+ *     Array.try_convert("1")   #=> nil
+ *
+ *     if tmp = Array.try_convert(arg)
+ *       # the argument is an array
+ *     elsif tmp = String.try_convert(arg)
+ *       # the argument is a string
+ *     end
+ *
+ */
+
 static VALUE
-Sary_create(argc, argv, class)
-    int argc;
-    VALUE *argv;
-    VALUE class;
+rb_ary_s_try_convert(VALUE dummy, VALUE ary)
 {
-    NEWOBJ(ary, struct RArray);
-    OBJSETUP(ary, class, T_ARRAY);
+    return rb_check_array_type(ary);
+}
 
-    ary->len = argc;
-    ary->capa = argc;
-    ary->ptr = ALLOC_N(VALUE, argc);
-    MEMCPY(ary->ptr, argv, VALUE, argc);
+/*
+ *  call-seq:
+ *     Array.new(size=0, default=nil)
+ *     Array.new(array)
+ *     Array.new(size) {|index| block }
+ *
+ *  Returns a new array.
+ *
+ *  In the first form, if no arguments are sent, the new array will be empty.
+ *  When a +size+ and an optional +default+ are sent, an array is created with
+ *  +size+ copies of +default+.  Take notice that all elements will reference the
+ *  same object +default+.
+ *
+ *  The second form creates a copy of the array passed as a parameter (the
+ *  array is generated by calling to_ary on the parameter).
+ *
+ *    first_array = ["Matz", "Guido"]
+ *
+ *    second_array = Array.new(first_array) #=> ["Matz", "Guido"]
+ *
+ *    first_array.equal? second_array       #=> false
+ *
+ *  In the last form, an array of the given size is created.  Each element in
+ *  this array is created by passing the element's index to the given block
+ *  and storing the return value.
+ *
+ *    Array.new(3) {|index| index ** 2}
+ *    # => [0, 1, 4]
+ *
+ *  == Common gotchas
+ *
+ *  When sending the second parameter, the same object will be used as the
+ *  value for all the array elements:
+ *
+ *     a = Array.new(2, Hash.new)
+ *     # => [{}, {}]
+ *
+ *     a[0]['cat'] = 'feline'
+ *     a # => [{"cat"=>"feline"}, {"cat"=>"feline"}]
+ *
+ *     a[1]['cat'] = 'Felix'
+ *     a # => [{"cat"=>"Felix"}, {"cat"=>"Felix"}]
+ *
+ *  Since all the Array elements store the same hash, changes to one of them
+ *  will affect them all.
+ *
+ *  If multiple copies are what you want, you should use the block
+ *  version which uses the result of that block each time an element
+ *  of the array needs to be initialized:
+ *
+ *     a = Array.new(2) {Hash.new}
+ *     a[0]['cat'] = 'feline'
+ *     a # => [{"cat"=>"feline"}, {}]
+ *
+ */
 
-    return (VALUE)ary;
+static VALUE
+rb_ary_initialize(int argc, VALUE *argv, VALUE ary)
+{
+    long len;
+    VALUE size, val;
+
+    rb_ary_modify(ary);
+    if (argc == 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_memfill(ary, 0, len, val);
+	ARY_SET_LEN(ary, len);
+    }
+    return ary;
 }
 
-static void
-astore(ary, idx, val)
-    struct RArray *ary;
-    int idx;
-    VALUE val;
+/*
+ * 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
+rb_ary_store(VALUE ary, long idx, VALUE val)
+{
+    long len = RARRAY_LEN(ary);
+
     if (idx < 0) {
-	Fail("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->capa/5;
-	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) {
-	MEMZERO(ary->ptr+ary->len, VALUE, 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);
 }
 
+static VALUE
+ary_make_partial(VALUE ary, VALUE klass, long offset, long len)
+{
+    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_make_shared_copy(VALUE ary)
+{
+    return ary_make_partial(ary, rb_obj_class(ary), 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)
+{
+    long n;
+    long len;
+    long offset = 0;
+
+    argc = rb_check_arity(argc, 0, 1);
+    /* the case optional argument is omitted should be handled in
+     * callers of this function.  if another arity case is added,
+     * this arity check needs to rewrite. */
+    RUBY_ASSERT_ALWAYS(argc == 1);
+
+    n = NUM2LONG(argv[0]);
+    len = RARRAY_LEN(ary);
+    if (n > len) {
+	n = len;
+    }
+    else if (n < 0) {
+	rb_raise(rb_eArgError, "negative array size");
+    }
+    if (last) {
+	offset = len - n;
+    }
+    return ary_make_partial(ary, rb_cArray, offset, n);
+}
+
+/*
+ *  call-seq:
+ *     ary << obj            -> ary
+ *
+ *  Append---Pushes the given object on to the end of this array. This
+ *  expression returns the array itself, so several appends
+ *  may be chained together.
+ *
+ *     a = [ 1, 2 ]
+ *     a << "c" << "d" << [ 3, 4 ]
+ *             #=>  [ 1, 2, "c", "d", [ 3, 4 ] ]
+ *     a
+ *             #=>  [ 1, 2, "c", "d", [ 3, 4 ] ]
+ *
+ */
+
 VALUE
-ary_push(ary, item)
-    struct RArray *ary;
-    VALUE item;
+rb_ary_push(VALUE ary, VALUE item)
 {
-    astore(ary, ary->len, item);
-    return (VALUE)ary;
+    long idx = RARRAY_LEN((ary_verify(ary), ary));
+    VALUE target_ary = ary_ensure_room_for_push(ary, 1);
+    RARRAY_PTR_USE_TRANSIENT(ary, ptr, {
+	RB_OBJ_WRITE(target_ary, &ptr[idx], item);
+    });
+    ARY_SET_LEN(ary, idx + 1);
+    ary_verify(ary);
+    return ary;
+}
+
+VALUE
+rb_ary_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;
 }
 
+/*
+ *  call-seq:
+ *     ary.push(obj, ...)    -> ary
+ *     ary.append(obj, ...)  -> ary
+ *
+ *  Append --- Pushes the given object(s) on to the end of this array. This
+ *  expression returns the array itself, so several appends
+ *  may be chained together. See also Array#pop for the opposite
+ *  effect.
+ *
+ *     a = [ "a", "b", "c" ]
+ *     a.push("d", "e", "f")
+ *             #=> ["a", "b", "c", "d", "e", "f"]
+ *     [1, 2, 3].push(4).push(5)
+ *             #=> [1, 2, 3, 4, 5]
+ */
+
 static VALUE
-Fary_append(ary, item)
-    struct RArray *ary;
-    VALUE item;
+rb_ary_push_m(int argc, VALUE *argv, VALUE ary)
 {
-    astore(ary, ary->len, item);
-    return (VALUE)ary;
+    return rb_ary_cat(ary, argv, argc);
 }
 
 VALUE
-ary_pop(ary)
-    struct RArray *ary;
+rb_ary_pop(VALUE ary)
 {
-    if (ary->len == 0) return Qnil;
-    return ary->ptr[--ary->len];
+    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:
+ *     ary.pop    -> obj or nil
+ *     ary.pop(n) -> new_ary
+ *
+ *  Removes the last element from +self+ and returns it, or
+ *  +nil+ if the array is empty.
+ *
+ *  If a number +n+ is given, returns an array of the last +n+ elements
+ *  (or less) just like <code>array.slice!(-n, n)</code> does. See also
+ *  Array#push for the opposite effect.
+ *
+ *     a = [ "a", "b", "c", "d" ]
+ *     a.pop     #=> "d"
+ *     a.pop(2)  #=> ["b", "c"]
+ *     a         #=> ["a"]
+ */
+
+static VALUE
+rb_ary_pop_m(int argc, VALUE *argv, VALUE ary)
+{
+    VALUE result;
+
+    if (argc == 0) {
+	return rb_ary_pop(ary);
+    }
+
+    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_shift(ary)
-    struct RArray *ary;
+rb_ary_shift(VALUE ary)
 {
     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 (ary->len == 0) return Qnil;
-
-    top = ary->ptr[0];
-    ary->len--;
+	ARY_SET(ary, 0, Qnil);
+	ary_make_shared(ary);
+    }
+    else if (ARY_SHARED_ROOT_OCCUPIED(ARY_SHARED_ROOT(ary))) {
+        RARRAY_PTR_USE_TRANSIENT(ary, ptr, ptr[0] = Qnil);
+    }
+    ARY_INCREASE_PTR(ary, 1);		/* shift ptr */
+    ARY_INCREASE_LEN(ary, -1);
 
-    /* sliding items */
-    memmove(ary->ptr, ary->ptr+1, sizeof(VALUE)*(ary->len));
+    ary_verify(ary);
 
     return top;
 }
 
+/*
+ *  call-seq:
+ *     ary.shift    -> obj or nil
+ *     ary.shift(n) -> new_ary
+ *
+ *  Removes the first element of +self+ and returns it (shifting all
+ *  other elements down by one). Returns +nil+ if the array
+ *  is empty.
+ *
+ *  If a number +n+ is given, returns an array of the first +n+ elements
+ *  (or less) just like <code>array.slice!(0, n)</code> does. With +ary+
+ *  containing only the remainder elements, not including what was shifted to
+ *  +new_ary+. See also Array#unshift for the opposite effect.
+ *
+ *     args = [ "-m", "-q", "filename" ]
+ *     args.shift     #=> "-m"
+ *     args           #=> ["-q", "filename"]
+ *
+ *     args = [ "-m", "-q", "filename" ]
+ *     args.shift(2)  #=> ["-m", "-q"]
+ *     args           #=> ["filename"]
+ */
+
+static VALUE
+rb_ary_shift_m(int argc, VALUE *argv, VALUE ary)
+{
+    VALUE result;
+    long n;
+
+    if (argc == 0) {
+	return rb_ary_shift(ary);
+    }
+
+    rb_ary_modify_check(ary);
+    result = ary_take_first_or_last(argc, argv, ary, ARY_TAKE_FIRST);
+    n = RARRAY_LEN(result);
+    rb_ary_behead(ary,n);
+
+    return result;
+}
+
+MJIT_FUNC_EXPORTED VALUE
+rb_ary_behead(VALUE ary, long n)
+{
+    if (n<=0) return ary;
+
+    rb_ary_modify_check(ary);
+    if (ARY_SHARED_P(ary)) {
+        if (ARY_SHARED_ROOT_OCCUPIED(ARY_SHARED_ROOT(ary))) {
+	  setup_occupied_shared:
+	    ary_mem_clear(ary, 0, n);
+	}
+        ARY_INCREASE_PTR(ary, n);
+    }
+    else {
+	if (RARRAY_LEN(ary) < ARY_DEFAULT_SIZE) {
+            RARRAY_PTR_USE_TRANSIENT(ary, ptr, {
+                MEMMOVE(ptr, ptr+n, VALUE, RARRAY_LEN(ary)-n);
+	    }); /* WB: no new reference */
+	}
+	else {
+	    ary_make_shared(ary);
+	    goto setup_occupied_shared;
+	}
+    }
+    ARY_INCREASE_LEN(ary, -n);
+
+    ary_verify(ary);
+    return ary;
+}
+
+static VALUE
+ary_ensure_room_for_unshift(VALUE ary, int argc)
+{
+    long len = RARRAY_LEN(ary);
+    long new_len = len + argc;
+    long capa;
+    const VALUE *head, *sharedp;
+
+    if (len > ARY_MAX_SIZE - argc) {
+	rb_raise(rb_eIndexError, "index %ld too big", new_len);
+    }
+
+    if (ARY_SHARED_P(ary)) {
+        VALUE shared_root = ARY_SHARED_ROOT(ary);
+        capa = RARRAY_LEN(shared_root);
+        if (ARY_SHARED_ROOT_OCCUPIED(shared_root) && capa > new_len) {
+            rb_ary_modify_check(ary);
+            head = RARRAY_CONST_PTR_TRANSIENT(ary);
+            sharedp = RARRAY_CONST_PTR_TRANSIENT(shared_root);
+	    goto makeroom_if_need;
+	}
+    }
+
+    rb_ary_modify(ary);
+    capa = ARY_CAPA(ary);
+    if (capa - (capa >> 6) <= new_len) {
+	ary_double_capa(ary, new_len);
+    }
+
+    /* use shared array for big "queues" */
+    if (new_len > ARY_DEFAULT_SIZE * 4) {
+        ary_verify(ary);
+
+        /* make a room for unshifted items */
+	capa = ARY_CAPA(ary);
+	ary_make_shared(ary);
+
+        head = sharedp = RARRAY_CONST_PTR_TRANSIENT(ary);
+	goto makeroom;
+      makeroom_if_need:
+	if (head - sharedp < argc) {
+	    long room;
+	  makeroom:
+	    room = capa - new_len;
+	    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);
+    }
+    else {
+	/* sliding items */
+        RARRAY_PTR_USE_TRANSIENT(ary, ptr, {
+	    MEMMOVE(ptr + argc, ptr, VALUE, len);
+	});
+
+        ary_verify(ary);
+	return ary;
+    }
+}
+
+/*
+ *  call-seq:
+ *     ary.unshift(obj, ...)  -> ary
+ *     ary.prepend(obj, ...)  -> ary
+ *
+ *  Prepends objects to the front of +self+, moving other elements upwards.
+ *  See also Array#shift for the opposite effect.
+ *
+ *     a = [ "b", "c", "d" ]
+ *     a.unshift("a")   #=> ["a", "b", "c", "d"]
+ *     a.unshift(1, 2)  #=> [ 1, 2, "a", "b", "c", "d"]
+ */
+
+static VALUE
+rb_ary_unshift_m(int argc, VALUE *argv, VALUE ary)
+{
+    long len = RARRAY_LEN(ary);
+    VALUE target_ary;
+
+    if (argc == 0) {
+	rb_ary_modify_check(ary);
+	return ary;
+    }
+
+    target_ary = ary_ensure_room_for_unshift(ary, argc);
+    ary_memcpy0(ary, 0, argc, argv, target_ary);
+    ARY_SET_LEN(ary, len + argc);
+    return ary;
+}
+
 VALUE
-ary_unshift(ary, item)
-    struct RArray *ary;
+rb_ary_unshift(VALUE ary, VALUE item)
 {
-    VALUE top;
+    return rb_ary_unshift_m(1,&item,ary);
+}
 
-    if (ary->len >= ary->capa) {
-	ary->capa+=ARY_DEFAULT_SIZE;
-	REALLOC_N(ary->ptr, VALUE, ary->capa);
+/* 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(VALUE ary, long beg, long len)
+{
+    VALUE klass;
+    long alen = RARRAY_LEN(ary);
+
+    if (beg > alen) return Qnil;
+    if (beg < 0 || len < 0) return Qnil;
 
-    /* sliding items */
-    memmove(ary->ptr+1, ary->ptr, sizeof(VALUE)*(ary->len));
+    if (alen < len || alen < beg + len) {
+	len = alen - beg;
+    }
+    klass = rb_obj_class(ary);
+    if (len == 0) return ary_new(klass, 0);
 
-    ary->len++;
-    return ary->ptr[0] = item;
+    return ary_make_partial(ary, klass, beg, len);
 }
 
+static VALUE rb_ary_aref2(VALUE ary, VALUE b, VALUE e);
+
+/*
+ *  call-seq:
+ *     ary[index]                -> obj     or nil
+ *     ary[start, length]        -> new_ary or nil
+ *     ary[range]                -> new_ary or nil
+ *     ary.slice(index)          -> obj     or nil
+ *     ary.slice(start, length)  -> new_ary or nil
+ *     ary.slice(range)          -> new_ary or nil
+ *
+ *  Element Reference --- Returns the element at +index+, or returns a
+ *  subarray starting at the +start+ index and continuing for +length+
+ *  elements, or returns a subarray specified by +range+ of indices.
+ *
+ *  Negative indices count backward from the end of the array (-1 is the last
+ *  element).  For +start+ and +range+ cases the starting index is just before
+ *  an element.  Additionally, an empty array is returned when the starting
+ *  index for an element range is at the end of the array.
+ *
+ *  Returns +nil+ if the index (or starting index) are out of range.
+ *
+ *     a = [ "a", "b", "c", "d", "e" ]
+ *     a[2] +  a[0] + a[1]    #=> "cab"
+ *     a[6]                   #=> nil
+ *     a[1, 2]                #=> [ "b", "c" ]
+ *     a[1..3]                #=> [ "b", "c", "d" ]
+ *     a[4..7]                #=> [ "e" ]
+ *     a[6..10]               #=> nil
+ *     a[-3, 3]               #=> [ "c", "d", "e" ]
+ *     # special cases
+ *     a[5]                   #=> nil
+ *     a[6, 1]                #=> nil
+ *     a[5, 1]                #=> []
+ *     a[5..10]               #=> []
+ *
+ */
+
 VALUE
-ary_entry(ary, offset)
-    struct RArray *ary;
-    int offset;
+rb_ary_aref(int argc, const VALUE *argv, VALUE ary)
 {
-    if (ary->len == 0) return Qnil;
+    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]);
+}
+
+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;
 
-    if (offset < 0) {
-	offset = ary->len + offset;
+    /* special case - speeding up */
+    if (FIXNUM_P(arg)) {
+	return rb_ary_entry(ary, FIX2LONG(arg));
     }
-    if (offset < 0 || ary->len <= offset) {
+    /* check if idx is Range */
+    switch (rb_range_beg_len(arg, &beg, &len, RARRAY_LEN(ary), 0)) {
+      case Qfalse:
+	break;
+      case Qnil:
 	return Qnil;
+      default:
+	return rb_ary_subseq(ary, beg, len);
     }
+    return rb_ary_entry(ary, NUM2LONG(arg));
+}
+
+/*
+ *  call-seq:
+ *     ary.at(index)   ->   obj  or nil
+ *
+ *  Returns the element at +index+. A negative index counts from the end of
+ *  +self+. Returns +nil+ if the index is out of range. See also
+ *  Array#[].
+ *
+ *     a = [ "a", "b", "c", "d", "e" ]
+ *     a.at(0)     #=> "a"
+ *     a.at(-1)    #=> "e"
+ */
 
-    return ary->ptr[offset];
+VALUE
+rb_ary_at(VALUE ary, VALUE pos)
+{
+    return rb_ary_entry(ary, NUM2LONG(pos));
 }
 
+/*
+ *  call-seq:
+ *     ary.first     ->   obj or nil
+ *     ary.first(n)  ->   new_ary
+ *
+ *  Returns the first element, or the first +n+ elements, of the array.
+ *  If the array is empty, the first form returns +nil+, and the
+ *  second form returns an empty array. See also Array#last for
+ *  the opposite effect.
+ *
+ *     a = [ "q", "r", "s", "t" ]
+ *     a.first     #=> "q"
+ *     a.first(2)  #=> ["q", "r"]
+ */
+
 static VALUE
-ary_subseq(ary, beg, len)
-    struct RArray *ary;
-    int beg, len;
+rb_ary_first(int argc, VALUE *argv, VALUE ary)
 {
-    struct RArray *ary2;
-    VALUE *ptr;
+    if (argc == 0) {
+	if (RARRAY_LEN(ary) == 0) return Qnil;
+	return RARRAY_AREF(ary, 0);
+    }
+    else {
+	return ary_take_first_or_last(argc, argv, ary, ARY_TAKE_FIRST);
+    }
+}
 
-    if (beg < 0) {
-	beg = ary->len + beg;
-	if (beg < 0) beg = 0;
+/*
+ *  call-seq:
+ *     ary.last     ->  obj or nil
+ *     ary.last(n)  ->  new_ary
+ *
+ *  Returns the last element(s) of +self+. If the array is empty,
+ *  the first form returns +nil+.
+ *
+ *  See also Array#first for the opposite effect.
+ *
+ *     a = [ "w", "x", "y", "z" ]
+ *     a.last     #=> "z"
+ *     a.last(2)  #=> ["y", "z"]
+ */
+
+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);
     }
-    if (len < 0) {
-	Fail("negative length for sub-array(size: %d)", ary->len);
+    else {
+	return ary_take_first_or_last(argc, argv, ary, ARY_TAKE_LAST);
     }
-    if (len == 0) {
-	return ary_new();
+}
+
+/*
+ *  call-seq:
+ *     ary.fetch(index)                    -> obj
+ *     ary.fetch(index, default)           -> obj
+ *     ary.fetch(index) {|index| block}    -> obj
+ *
+ *  Tries to return the element at position +index+, but throws an IndexError
+ *  exception if the referenced +index+ lies outside of the array bounds.  This
+ *  error can be prevented by supplying a second argument, which will act as a
+ *  +default+ value.
+ *
+ *  Alternatively, if a block is given it will only be executed when an
+ *  invalid +index+ is referenced.
+ *
+ *  Negative values of +index+ count from the end of the array.
+ *
+ *     a = [ 11, 22, 33, 44 ]
+ *     a.fetch(1)               #=> 22
+ *     a.fetch(-1)              #=> 44
+ *     a.fetch(4, 'cat')        #=> "cat"
+ *     a.fetch(100) {|i| puts "#{i} is out of bounds"}
+ *                              #=> "100 is out of bounds"
+ */
+
+static VALUE
+rb_ary_fetch(int argc, VALUE *argv, VALUE ary)
+{
+    VALUE pos, ifnone;
+    long block_given;
+    long idx;
+
+    rb_scan_args(argc, argv, "11", &pos, &ifnone);
+    block_given = rb_block_given_p();
+    if (block_given && argc == 2) {
+	rb_warn("block supersedes default value argument");
     }
-    if (beg + len > ary->len) {
-	len = ary->len - beg;
+    idx = NUM2LONG(pos);
+
+    if (idx < 0) {
+	idx +=  RARRAY_LEN(ary);
     }
+    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:
+ *     ary.find_index(obj)             ->  int or nil
+ *     ary.find_index {|item| block}  ->  int or nil
+ *     ary.find_index                  ->  Enumerator
+ *     ary.index(obj)             ->  int or nil
+ *     ary.index {|item| block}   ->  int or nil
+ *     ary.index                  ->  Enumerator
+ *
+ *  Returns the _index_ of the first object in +ary+ such that the object is
+ *  <code>==</code> to +obj+.
+ *
+ *  If a block is given instead of an argument, returns the _index_ of the
+ *  first object for which the block returns +true+.  Returns +nil+ if no
+ *  match is found.
+ *
+ *  See also Array#rindex.
+ *
+ *  An Enumerator is returned if neither a block nor argument is given.
+ *
+ *     a = [ "a", "b", "c" ]
+ *     a.index("b")              #=> 1
+ *     a.index("z")              #=> nil
+ *     a.index {|x| x == "b"}    #=> 1
+ */
 
-    ary2 = (struct RArray*)ary_new2(len);
-    MEMCPY(ary2->ptr, ary->ptr+beg, VALUE, len);
-    ary2->len = len;
+static VALUE
+rb_ary_index(int argc, VALUE *argv, VALUE ary)
+{
+    VALUE val;
+    long i;
 
-    return (VALUE)ary2;
+    if (argc == 0) {
+	RETURN_ENUMERATOR(ary, 0, 0);
+	for (i=0; i<RARRAY_LEN(ary); i++) {
+	    if (RTEST(rb_yield(RARRAY_AREF(ary, i)))) {
+		return LONG2NUM(i);
+	    }
+	}
+	return Qnil;
+    }
+    rb_check_arity(argc, 0, 1);
+    val = argv[0];
+    if (rb_block_given_p())
+	rb_warn("given block not used");
+    for (i=0; i<RARRAY_LEN(ary); i++) {
+	VALUE e = RARRAY_AREF(ary, i);
+	if (rb_equal(e, val)) {
+	    return LONG2NUM(i);
+	}
+    }
+    return Qnil;
+}
+
+/*
+ *  call-seq:
+ *     ary.rindex(obj)             ->  int or nil
+ *     ary.rindex {|item| block}   ->  int or nil
+ *     ary.rindex                  ->  Enumerator
+ *
+ *  Returns the _index_ of the last object in +self+ <code>==</code> to +obj+.
+ *
+ *  If a block is given instead of an argument, returns the _index_ of the
+ *  first object for which the block returns +true+, starting from the last
+ *  object.
+ *
+ *  Returns +nil+ if no match is found.
+ *
+ *  See also Array#index.
+ *
+ *  If neither block nor argument is given, an Enumerator is returned instead.
+ *
+ *     a = [ "a", "b", "b", "b", "c" ]
+ *     a.rindex("b")             #=> 3
+ *     a.rindex("z")             #=> nil
+ *     a.rindex {|x| x == "b"}   #=> 3
+ */
+
+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;
+    }
+    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;
 }
 
-extern VALUE C_Range;
+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
-range_beg_end(range, begp, lenp, len)
-    VALUE range;
-    int *begp, *lenp;
-    int len;
+rb_ary_splice(VALUE ary, long beg, long len, const VALUE *rptr, long rlen)
 {
-    int beg, end;
+    long olen;
+    long rofs;
 
-    beg = rb_iv_get(range, "start"); beg = NUM2INT(beg);
-    end = rb_iv_get(range, "end");   end = NUM2INT(end);
+    if (len < 0) rb_raise(rb_eIndexError, "negative length (%ld)", len);
+    olen = RARRAY_LEN(ary);
     if (beg < 0) {
-	beg = 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 (end < 0) {
-	end = len + end;
-	if (end < 0) end = 0;
+
+    {
+        const VALUE *optr = RARRAY_CONST_PTR_TRANSIENT(ary);
+	rofs = (rptr >= optr && rptr < optr + olen) ? rptr - optr : -1;
     }
-    if (beg > end) {
-	int tmp;
 
-	Warning("start %d is bigger than end %d", beg, end);
-	tmp = beg; beg = end; end = tmp;
+    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);
+	}
+	ARY_SET_LEN(ary, len);
+    }
+    else {
+	long alen;
+
+	if (olen - len > ARY_MAX_SIZE - rlen) {
+	    rb_raise(rb_eIndexError, "index %ld too big", olen + rlen - len);
+	}
+	rb_ary_modify(ary);
+	alen = olen + rlen - len;
+	if (alen >= ARY_CAPA(ary)) {
+	    ary_double_capa(ary, alen);
+	}
+
+	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));
+	}
     }
-    *begp = beg; *lenp = end - beg + 1;
 }
 
+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);
+	}
+	ARY_SET_HEAP_LEN(ary, len);
+    }
+    ary_verify(ary);
+    return ary;
+}
+
+/*
+ *  call-seq:
+ *     ary[index]         = obj                      ->  obj
+ *     ary[start, length] = obj or other_ary or nil  ->  obj or other_ary or nil
+ *     ary[range]         = obj or other_ary or nil  ->  obj or other_ary or nil
+ *
+ *  Element Assignment --- Sets the element at +index+, or replaces a subarray
+ *  from the +start+ index for +length+ elements, or replaces a subarray
+ *  specified by the +range+ of indices.
+ *
+ *  If indices are greater than the current capacity of the array, the array
+ *  grows automatically.  Elements are inserted into the array at +start+ if
+ *  +length+ is zero.
+ *
+ *  Negative indices will count backward from the end of the array.  For
+ *  +start+ and +range+ cases the starting index is just before an element.
+ *
+ *  An IndexError is raised if a negative index points past the beginning of
+ *  the array.
+ *
+ *  See also Array#push, and Array#unshift.
+ *
+ *     a = Array.new
+ *     a[4] = "4";                 #=> [nil, nil, nil, nil, "4"]
+ *     a[0, 3] = [ 'a', 'b', 'c' ] #=> ["a", "b", "c", nil, "4"]
+ *     a[1..2] = [ 1, 2 ]          #=> ["a", 1, 2, nil, "4"]
+ *     a[0, 2] = "?"               #=> ["?", 2, nil, "4"]
+ *     a[0..2] = "A"               #=> ["A", "4"]
+ *     a[-1]   = "Z"               #=> ["A", "Z"]
+ *     a[1..-1] = nil              #=> ["A", nil]
+ *     a[1..-1] = []               #=> ["A"]
+ *     a[0, 0] = [ 1, 2 ]          #=> [1, 2, "A"]
+ *     a[3, 0] = "B"               #=> [1, 2, "A", "B"]
+ */
+
 static VALUE
-Fary_aref(argc, argv, ary)
-    int argc;
-    VALUE *argv;
-    struct RArray *ary;
+rb_ary_aset(int argc, VALUE *argv, VALUE ary)
 {
-    VALUE arg1, arg2;
+    long offset, beg, len;
+    VALUE rpl;
+
+    if (argc == 3) {
+	rb_ary_modify_check(ary);
+	beg = NUM2LONG(argv[0]);
+	len = NUM2LONG(argv[1]);
+	goto range;
+    }
+    rb_check_arity(argc, 2, 2);
+    rb_ary_modify_check(ary);
+    if (FIXNUM_P(argv[0])) {
+	offset = FIX2LONG(argv[0]);
+	goto fixnum;
+    }
+    if (rb_range_beg_len(argv[0], &beg, &len, RARRAY_LEN(ary), 1)) {
+	/* check if idx is Range */
+      range:
+	rpl = rb_ary_to_ary(argv[argc-1]);
+        rb_ary_splice(ary, beg, len, RARRAY_CONST_PTR_TRANSIENT(rpl), RARRAY_LEN(rpl));
+	RB_GC_GUARD(rpl);
+	return argv[argc-1];
+    }
+
+    offset = NUM2LONG(argv[0]);
+fixnum:
+    rb_ary_store(ary, offset, argv[1]);
+    return argv[1];
+}
 
-    if (rb_scan_args(argc, argv, "11", &arg1, &arg2) == 2) {
-	int beg, len;
+/*
+ *  call-seq:
+ *     ary.insert(index, obj...)  -> ary
+ *
+ *  Inserts the given values before the element with the given +index+.
+ *
+ *  Negative indices count backwards from the end of the array, where +-1+ is
+ *  the last element. If a negative index is used, the given values will be
+ *  inserted after that element, so using an index of +-1+ will insert the
+ *  values at the end of the array.
+ *
+ *     a = %w{ a b c d }
+ *     a.insert(2, 99)         #=> ["a", "b", 99, "c", "d"]
+ *     a.insert(-2, 1, 2, 3)   #=> ["a", "b", 99, "c", 1, 2, 3, "d"]
+ */
 
-	beg = NUM2INT(arg1);
-	len = NUM2INT(arg2);
-	if (len <= 0) {
-	    return ary_new();
+static VALUE
+rb_ary_insert(int argc, VALUE *argv, VALUE ary)
+{
+    long pos;
+
+    rb_check_arity(argc, 1, UNLIMITED_ARGUMENTS);
+    rb_ary_modify_check(ary);
+    pos = NUM2LONG(argv[0]);
+    if (argc == 1) return ary;
+    if (pos == -1) {
+	pos = RARRAY_LEN(ary);
+    }
+    else if (pos < 0) {
+	long minpos = -RARRAY_LEN(ary) - 1;
+	if (pos < minpos) {
+	    rb_raise(rb_eIndexError, "index %ld too small for array; minimum: %ld",
+		     pos, minpos);
 	}
-	return ary_subseq(ary, beg, len);
+	pos++;
     }
+    rb_ary_splice(ary, pos, 0, argv + 1, argc - 1);
+    return ary;
+}
 
-    /* special case - speeding up */
-    if (FIXNUM_P(arg1)) {
-	return ary_entry(ary, NUM2INT(arg1));
+static VALUE
+rb_ary_length(VALUE ary);
+
+static VALUE
+ary_enum_length(VALUE ary, VALUE args, VALUE eobj)
+{
+    return rb_ary_length(ary);
+}
+
+/*
+ *  call-seq:
+ *     ary.each {|item| block}    -> ary
+ *     ary.each                   -> Enumerator
+ *
+ *  Calls the given block once for each element in +self+, passing that element
+ *  as a parameter.  Returns the array itself.
+ *
+ *  If no block is given, an Enumerator is returned.
+ *
+ *     a = [ "a", "b", "c" ]
+ *     a.each {|x| print x, " -- " }
+ *
+ *  produces:
+ *
+ *     a -- b -- c --
+ */
+
+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 ary;
+}
 
-    /* check if idx is Range */
-    if (obj_is_kind_of(arg1, C_Range)) {
-	int beg, len;
+/*
+ *  call-seq:
+ *     ary.each_index {|index| block}    -> ary
+ *     ary.each_index                    -> Enumerator
+ *
+ *  Same as Array#each, but passes the +index+ of the element instead of the
+ *  element itself.
+ *
+ *  An Enumerator is returned if no block is given.
+ *
+ *     a = [ "a", "b", "c" ]
+ *     a.each_index {|x| print x, " -- " }
+ *
+ *  produces:
+ *
+ *     0 -- 1 -- 2 --
+ */
+
+static VALUE
+rb_ary_each_index(VALUE ary)
+{
+    long i;
+    RETURN_SIZED_ENUMERATOR(ary, 0, 0, ary_enum_length);
+
+    for (i=0; i<RARRAY_LEN(ary); i++) {
+	rb_yield(LONG2NUM(i));
+    }
+    return ary;
+}
+
+/*
+ *  call-seq:
+ *     ary.reverse_each {|item| block}    -> ary
+ *     ary.reverse_each                   -> Enumerator
+ *
+ *  Same as Array#each, but traverses +self+ in reverse order.
+ *
+ *     a = [ "a", "b", "c" ]
+ *     a.reverse_each {|x| print x, " " }
+ *
+ *  produces:
+ *
+ *     c b a
+ */
 
-	range_beg_end(arg1, &beg, &len, ary->len);
-	return ary_subseq(ary, beg, len);
+static VALUE
+rb_ary_reverse_each(VALUE ary)
+{
+    long len;
+
+    RETURN_SIZED_ENUMERATOR(ary, 0, 0, ary_enum_length);
+    len = RARRAY_LEN(ary);
+    while (len--) {
+	long nlen;
+	rb_yield(RARRAY_AREF(ary, len));
+	nlen = RARRAY_LEN(ary);
+	if (nlen < len) {
+	    len = nlen;
+	}
     }
+    return ary;
+}
+
+/*
+ *  call-seq:
+ *     ary.length -> int
+ *
+ *  Returns the number of elements in +self+. May be zero.
+ *
+ *     [ 1, 2, 3, 4, 5 ].length   #=> 5
+ *     [].length                  #=> 0
+ */
+
+static VALUE
+rb_ary_length(VALUE ary)
+{
+    long len = RARRAY_LEN(ary);
+    return LONG2NUM(len);
+}
+
+/*
+ *  call-seq:
+ *     ary.empty?   -> true or false
+ *
+ *  Returns +true+ if +self+ contains no elements.
+ *
+ *     [].empty?   #=> true
+ */
+
+static VALUE
+rb_ary_empty_p(VALUE ary)
+{
+    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;
+}
 
-    return ary_entry(ary, NUM2INT(arg1));
+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
-Fary_index(ary, val)
-    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 void
+ary_join_0(VALUE ary, VALUE sep, long max, VALUE result)
+{
+    long i;
     VALUE val;
+
+    if (max > 0) rb_enc_copy(result, RARRAY_AREF(ary, 0));
+    for (i=0; i<max; i++) {
+	val = RARRAY_AREF(ary, i);
+	if (i > 0 && !NIL_P(sep))
+	    rb_str_buf_append(result, sep);
+	rb_str_buf_append(result, val);
+    }
+}
+
+static void
+ary_join_1(VALUE obj, VALUE ary, VALUE sep, long i, VALUE result, int *first)
 {
-    int i;
+    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)) {
+	  str_join:
+	    rb_str_buf_append(result, val);
+	    if (*first) {
+		rb_enc_copy(result, val);
+		*first = FALSE;
+	    }
+	}
+	else if (RB_TYPE_P(val, T_ARRAY)) {
+	    obj = val;
+	  ary_join:
+	    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);
+	    }
+	}
+	else {
+	    tmp = rb_check_string_type(val);
+	    if (!NIL_P(tmp)) {
+		val = tmp;
+		goto str_join;
+	    }
+	    tmp = rb_check_array_type(val);
+	    if (!NIL_P(tmp)) {
+		obj = val;
+		val = tmp;
+		goto ary_join;
+	    }
+	    val = rb_obj_as_string(val);
+	    goto str_join;
+	}
+    }
+}
+
+VALUE
+rb_ary_join(VALUE ary, VALUE sep)
+{
+    long len = 1, i;
+    VALUE val, tmp, result;
+
+    if (RARRAY_LEN(ary) == 0) return rb_usascii_str_new(0, 0);
+
+    if (!NIL_P(sep)) {
+	StringValue(sep);
+	len += RSTRING_LEN(sep) * (RARRAY_LEN(ary) - 1);
+    }
+    for (i=0; i<RARRAY_LEN(ary); i++) {
+	val = RARRAY_AREF(ary, i);
+	tmp = rb_check_string_type(val);
+
+	if (NIL_P(tmp) || tmp != val) {
+	    int first;
+	    result = rb_str_buf_new(len + (RARRAY_LEN(ary)-i)*10);
+	    rb_enc_associate(result, rb_usascii_encoding());
+	    ary_join_0(ary, sep, i, result);
+	    first = i == 0;
+	    ary_join_1(ary, ary, sep, i, result, &first);
+	    return 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:
+ *     ary.join(separator=$,)    -> str
+ *
+ *  Returns a string created by converting each element of the array to
+ *  a string, separated by the given +separator+.
+ *  If the +separator+ is +nil+, it uses current <code>$,</code>.
+ *  If both the +separator+ and <code>$,</code> are +nil+,
+ *  it uses an empty string.
+ *
+ *     [ "a", "b", "c" ].join        #=> "abc"
+ *     [ "a", "b", "c" ].join("-")   #=> "a-b-c"
+ *
+ *  For nested arrays, join is applied recursively:
+ *
+ *     [ "a", [1, 2, [:x, :y]], "b" ].join("-")   #=> "a-1-2-x-y-b"
+ */
+
+static VALUE
+rb_ary_join_m(int argc, VALUE *argv, VALUE ary)
+{
+    VALUE sep;
+
+    if (rb_check_arity(argc, 0, 1) == 0 || NIL_P(sep = argv[0])) {
+        sep = rb_output_fs;
+        if (!NIL_P(sep)) {
+            rb_warn("$, is set to non-nil value");
+        }
+    }
+
+    return rb_ary_join(ary, sep);
+}
+
+static VALUE
+inspect_ary(VALUE ary, VALUE dummy, int recur)
+{
+    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:
+ *     ary.inspect  -> string
+ *     ary.to_s     -> string
+ *
+ *  Creates a string representation of +self+, by calling #inspect
+ *  on each element.
+ *
+ *     [ "a", "b", "c" ].to_s     #=> "[\"a\", \"b\", \"c\"]"
+ */
+
+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
+rb_ary_to_s(VALUE ary)
+{
+    return rb_ary_inspect(ary);
+}
 
-    for (i=0; i<ary->len; i++) {
-	if (rb_equal(ary->ptr[i], val))
-	    return INT2FIX(i);
+/*
+ *  call-seq:
+ *     ary.to_a     -> ary
+ *
+ *  Returns +self+.
+ *
+ *  If called on a subclass of Array, converts the receiver to an Array object.
+ */
+
+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 ary;
+}
+
+/*
+ *  call-seq:
+ *     ary.to_h                  -> hash
+ *     ary.to_h {|item| block }  -> hash
+ *
+ *  Returns the result of interpreting <i>ary</i> as an array of
+ *  <tt>[key, value]</tt> pairs.
+ *
+ *     [[:foo, :bar], [1, 2]].to_h
+ *       # => {:foo => :bar, 1 => 2}
+ *
+ *  If a block is given, the results of the block on each element of
+ *  the array will be used as pairs.
+ *
+ *     ["foo", "bar"].to_h {|s| [s.ord, s]}
+ *       # => {102=>"foo", 98=>"bar"}
+ */
+
+static VALUE
+rb_ary_to_h(VALUE ary)
+{
+    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;
+}
+
+/*
+ *  call-seq:
+ *     ary.to_ary -> ary
+ *
+ *  Returns +self+.
+ */
+
+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;
+    }
+}
+
+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:
+ *     ary.reverse!   -> ary
+ *
+ *  Reverses +self+ in place.
+ *
+ *     a = [ "a", "b", "c" ]
+ *     a.reverse!       #=> ["c", "b", "a"]
+ *     a                #=> ["c", "b", "a"]
+ */
+
+static VALUE
+rb_ary_reverse_bang(VALUE ary)
+{
+    return rb_ary_reverse(ary);
+}
+
+/*
+ *  call-seq:
+ *     ary.reverse    -> new_ary
+ *
+ *  Returns a new array containing +self+'s elements in reverse order.
+ *
+ *     [ "a", "b", "c" ].reverse   #=> ["c", "b", "a"]
+ *     [ 1 ].reverse               #=> [1]
+ */
+
+static VALUE
+rb_ary_reverse_m(VALUE ary)
+{
+    long len = RARRAY_LEN(ary);
+    VALUE dup = rb_ary_new2(len);
+
+    if (len > 0) {
+        const VALUE *p1 = RARRAY_CONST_PTR_TRANSIENT(ary);
+        VALUE *p2 = (VALUE *)RARRAY_CONST_PTR_TRANSIENT(dup) + len - 1;
+	do *p2-- = *p1++; while (--len > 0);
+    }
+    ARY_SET_LEN(dup, RARRAY_LEN(ary));
+    return dup;
+}
+
+static inline long
+rotate_count(long cnt, long len)
+{
+    return (cnt < 0) ? (len - (~cnt % len) - 1) : (cnt % len);
+}
+
+static void
+ary_rotate_ptr(VALUE *ptr, long len, long cnt)
+{
+    --len;
+    if (cnt < len) ary_reverse(ptr + cnt, ptr + len);
+    if (--cnt > 0) ary_reverse(ptr, ptr + cnt);
+    if (len > 0) ary_reverse(ptr, ptr + len);
+}
+
+VALUE
+rb_ary_rotate(VALUE ary, long cnt)
+{
+    rb_ary_modify(ary);
+
+    if (cnt != 0) {
+        long len = RARRAY_LEN(ary);
+        if (len > 0 && (cnt = rotate_count(cnt, len)) > 0) {
+            RARRAY_PTR_USE_TRANSIENT(ary, ptr, ary_rotate_ptr(ptr, len, cnt));
+            return ary;
+        }
     }
     return Qnil;
 }
 
+/*
+ *  call-seq:
+ *     ary.rotate!(count=1)   -> ary
+ *
+ *  Rotates +self+ in place so that the element at +count+ comes first, and
+ *  returns +self+.
+ *
+ *  If +count+ is negative then it rotates in the opposite direction, starting
+ *  from the end of the array where +-1+ is the last element.
+ *
+ *     a = [ "a", "b", "c", "d" ]
+ *     a.rotate!        #=> ["b", "c", "d", "a"]
+ *     a                #=> ["b", "c", "d", "a"]
+ *     a.rotate!(2)     #=> ["d", "a", "b", "c"]
+ *     a.rotate!(-3)    #=> ["a", "b", "c", "d"]
+ */
+
 static VALUE
-Fary_indexes(ary, args)
-    struct RArray *ary, *args;
+rb_ary_rotate_bang(int argc, VALUE *argv, VALUE ary)
 {
-    VALUE *p, *pend;
-    VALUE new;
-    int i = 0;
+    long n = (rb_check_arity(argc, 0, 1) ? NUM2LONG(argv[0]) : 1);
+    rb_ary_rotate(ary, n);
+    return ary;
+}
+
+/*
+ *  call-seq:
+ *     ary.rotate(count=1)    -> new_ary
+ *
+ *  Returns a new array by rotating +self+ so that the element at +count+ is
+ *  the first element of the new array.
+ *
+ *  If +count+ is negative then it rotates in the opposite direction, starting
+ *  from the end of +self+ where +-1+ is the last element.
+ *
+ *     a = [ "a", "b", "c", "d" ]
+ *     a.rotate         #=> ["b", "c", "d", "a"]
+ *     a                #=> ["a", "b", "c", "d"]
+ *     a.rotate(2)      #=> ["c", "d", "a", "b"]
+ *     a.rotate(-3)     #=> ["b", "c", "d", "a"]
+ */
 
-    if (!args || args->len == 1) {
-	args = (struct RArray*)rb_to_a(args->ptr[0]);
+static VALUE
+rb_ary_rotate_m(int argc, VALUE *argv, VALUE ary)
+{
+    VALUE rotated;
+    const VALUE *ptr;
+    long len;
+    long cnt = (rb_check_arity(argc, 0, 1) ? NUM2LONG(argv[0]) : 1);
+
+    len = RARRAY_LEN(ary);
+    rotated = rb_ary_new2(len);
+    if (len > 0) {
+	cnt = rotate_count(cnt, len);
+        ptr = RARRAY_CONST_PTR_TRANSIENT(ary);
+	len -= cnt;
+	ary_memcpy(rotated, 0, len, ptr + cnt);
+	ary_memcpy(rotated, len, cnt, ptr);
     }
+    ARY_SET_LEN(rotated, RARRAY_LEN(ary));
+    return rotated;
+}
 
-    new = ary_new2(args->len);
+struct ary_sort_data {
+    VALUE ary;
+    struct cmp_opt_data cmp_opt;
+};
 
-    p = args->ptr; pend = p + args->len;
-    while (p < pend) {
-	astore(new, i++, ary_entry(ary, NUM2INT(*p)));
-	p++;
+static VALUE
+sort_reentered(VALUE ary)
+{
+    if (RBASIC(ary)->klass) {
+	rb_raise(rb_eRuntimeError, "sort reentered");
     }
-    return new;
+    return Qnil;
+}
+
+static int
+sort_1(const void *ap, const void *bp, void *dummy)
+{
+    struct ary_sort_data *data = dummy;
+    VALUE retval = sort_reentered(data->ary);
+    VALUE a = *(const VALUE *)ap, b = *(const VALUE *)bp;
+    VALUE args[2];
+    int n;
+
+    args[0] = a;
+    args[1] = b;
+    retval = rb_yield_values2(2, args);
+    n = rb_cmpint(retval, a, b);
+    sort_reentered(data->ary);
+    return n;
 }
 
+static int
+sort_2(const void *ap, const void *bp, void *dummy)
+{
+    struct ary_sort_data *data = dummy;
+    VALUE retval = sort_reentered(data->ary);
+    VALUE a = *(const VALUE *)ap, b = *(const VALUE *)bp;
+    int n;
+
+    if (FIXNUM_P(a) && FIXNUM_P(b) && CMP_OPTIMIZABLE(data->cmp_opt, Fixnum)) {
+	if ((long)a > (long)b) return 1;
+	if ((long)a < (long)b) return -1;
+	return 0;
+    }
+    if (STRING_P(a) && STRING_P(b) && CMP_OPTIMIZABLE(data->cmp_opt, String)) {
+	return rb_str_cmp(a, b);
+    }
+    if (RB_FLOAT_TYPE_P(a) && CMP_OPTIMIZABLE(data->cmp_opt, Float)) {
+	return rb_float_cmp(a, b);
+    }
+
+    retval = rb_funcallv(a, id_cmp, 1, &b);
+    n = rb_cmpint(retval, a, b);
+    sort_reentered(data->ary);
+
+    return n;
+}
+
+/*
+ *  call-seq:
+ *     ary.sort!                   -> ary
+ *     ary.sort! {|a, b| block}    -> ary
+ *
+ *  Sorts +self+ in place.
+ *
+ *  Comparisons for the sort will be done using the <code><=></code> operator
+ *  or using an optional code block.
+ *
+ *  The block must implement a comparison between +a+ and +b+ and return
+ *  an integer less than 0 when +b+ follows +a+, +0+ when +a+ and +b+
+ *  are equivalent, or an integer greater than 0 when +a+ follows +b+.
+ *
+ *  The result is not guaranteed to be stable.  When the comparison of two
+ *  elements returns +0+, the order of the elements is unpredictable.
+ *
+ *     ary = [ "d", "a", "e", "c", "b" ]
+ *     ary.sort!                     #=> ["a", "b", "c", "d", "e"]
+ *     ary.sort! {|a, b| b <=> a}    #=> ["e", "d", "c", "b", "a"]
+ *
+ *  See also Enumerable#sort_by.
+ */
+
+VALUE
+rb_ary_sort_bang(VALUE ary)
+{
+    rb_ary_modify(ary);
+    assert(!ARY_SHARED_P(ary));
+    if (RARRAY_LEN(ary) > 1) {
+	VALUE tmp = ary_make_substitution(ary); /* only ary refers tmp */
+	struct ary_sort_data data;
+	long len = RARRAY_LEN(ary);
+	RBASIC_CLEAR_CLASS(tmp);
+	data.ary = tmp;
+	data.cmp_opt.opt_methods = 0;
+	data.cmp_opt.opt_inited = 0;
+	RARRAY_PTR_USE(tmp, ptr, {
+            ruby_qsort(ptr, len, sizeof(VALUE),
+                       rb_block_given_p()?sort_1:sort_2, &data);
+	}); /* WB: no new reference */
+	rb_ary_modify(ary);
+        if (ARY_EMBED_P(tmp)) {
+            if (ARY_SHARED_P(ary)) { /* ary might be destructively operated in the given block */
+                rb_ary_unshare(ary);
+		FL_SET_EMBED(ary);
+            }
+	    ary_memcpy(ary, 0, ARY_EMBED_LEN(tmp), ARY_EMBED_PTR(tmp));
+            ARY_SET_LEN(ary, ARY_EMBED_LEN(tmp));
+        }
+        else {
+            if (!ARY_EMBED_P(ary) && ARY_HEAP_PTR(ary) == ARY_HEAP_PTR(tmp)) {
+                FL_UNSET_SHARED(ary);
+                ARY_SET_CAPA(ary, RARRAY_LEN(tmp));
+            }
+            else {
+                assert(!ARY_SHARED_P(tmp));
+                if (ARY_EMBED_P(ary)) {
+                    FL_UNSET_EMBED(ary);
+                }
+                else if (ARY_SHARED_P(ary)) {
+                    /* ary might be destructively operated in the given block */
+                    rb_ary_unshare(ary);
+                }
+                else {
+                    ary_heap_free(ary);
+                }
+                ARY_SET_PTR(ary, ARY_HEAP_PTR(tmp));
+                ARY_SET_HEAP_LEN(ary, len);
+                ARY_SET_CAPA(ary, ARY_HEAP_LEN(tmp));
+            }
+            /* tmp was lost ownership for the ptr */
+            FL_UNSET(tmp, FL_FREEZE);
+            FL_SET_EMBED(tmp);
+            ARY_SET_EMBED_LEN(tmp, 0);
+            FL_SET(tmp, FL_FREEZE);
+        }
+        /* tmp will be GC'ed. */
+        RBASIC_SET_CLASS_RAW(tmp, rb_cArray); /* rb_cArray must be marked */
+    }
+    ary_verify(ary);
+    return ary;
+}
+
+/*
+ *  call-seq:
+ *     ary.sort                   -> new_ary
+ *     ary.sort {|a, b| block}    -> new_ary
+ *
+ *  Returns a new array created by sorting +self+.
+ *
+ *  Comparisons for the sort will be done using the <code><=></code> operator
+ *  or using an optional code block.
+ *
+ *  The block must implement a comparison between +a+ and +b+ and return
+ *  an integer less than 0 when +b+ follows +a+, +0+ when +a+ and +b+
+ *  are equivalent, or an integer greater than 0 when +a+ follows +b+.
+ *
+ *  The result is not guaranteed to be stable.  When the comparison of two
+ *  elements returns +0+, the order of the elements is unpredictable.
+ *
+ *     ary = [ "d", "a", "e", "c", "b" ]
+ *     ary.sort                     #=> ["a", "b", "c", "d", "e"]
+ *     ary.sort {|a, b| b <=> a}    #=> ["e", "d", "c", "b", "a"]
+ *
+ *  To produce the reverse order, the following can also be used
+ *  (and may be faster):
+ *
+ *    ary.sort.reverse!             #=> ["e", "d", "c", "b", "a"]
+ *
+ *  See also 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:
+ *     ary.bsearch {|x| block }  -> elem
+ *
+ *  By using binary search, finds a value from this array which meets
+ *  the given condition in O(log n) where n is the size of the array.
+ *
+ *  You can use this method in two modes: a find-minimum mode and
+ *  a find-any mode.  In either case, the elements of the array must be
+ *  monotone (or sorted) with respect to the block.
+ *
+ *  In find-minimum mode (this is a good choice for typical use cases),
+ *  the block must always return true or false, and there must be an index i
+ *  (0 <= i <= ary.size) so that:
+ *
+ *  - the block returns false for any element whose index is less than
+ *    i, and
+ *  - the block returns true for any element whose index is greater
+ *    than or equal to i.
+ *
+ *  This method returns the i-th element.  If i is equal to ary.size,
+ *  it returns nil.
+ *
+ *     ary = [0, 4, 7, 10, 12]
+ *     ary.bsearch {|x| x >=   4 } #=> 4
+ *     ary.bsearch {|x| x >=   6 } #=> 7
+ *     ary.bsearch {|x| x >=  -1 } #=> 0
+ *     ary.bsearch {|x| x >= 100 } #=> nil
+ *
+ *  In find-any mode (this behaves like libc's bsearch(3)), the block
+ *  must always return a number, and there must be two indices i and j
+ *  (0 <= i <= j <= ary.size) so that:
+ *
+ *  - the block returns a positive number for ary[k] if 0 <= k < i,
+ *  - the block returns zero for ary[k] if i <= k < j, and
+ *  - the block returns a negative number for ary[k] if
+ *    j <= k < ary.size.
+ *
+ *  Under this condition, this method returns any element whose index
+ *  is within i...j.  If i is equal to j (i.e., there is no element
+ *  that satisfies the block), this method returns nil.
+ *
+ *     ary = [0, 4, 7, 10, 12]
+ *     # try to find v such that 4 <= v < 8
+ *     ary.bsearch {|x| 1 - x / 4 } #=> 4 or 7
+ *     # try to find v such that 8 <= v < 10
+ *     ary.bsearch {|x| 4 - x / 2 } #=> nil
+ *
+ *  You must not mix the two modes at a time; the block must always
+ *  return either true/false, or always return a number.  It is
+ *  undefined which value is actually picked up at each iteration.
+ */
+
 static VALUE
-Fary_aset(argc, argv, ary)
-    int argc;
-    VALUE *argv;
-    struct RArray *ary;
+rb_ary_bsearch(VALUE ary)
 {
-    VALUE arg1, arg2;
-    struct RArray *arg3;
-    int offset;
+    VALUE index_result = rb_ary_bsearch_index(ary);
 
-    if (rb_scan_args(argc, argv, "21", &arg1, &arg2, &arg3) == 3) {
-	int beg, len;
+    if (FIXNUM_P(index_result)) {
+	return rb_ary_entry(ary, FIX2LONG(index_result));
+    }
+    return index_result;
+}
+
+/*
+ *  call-seq:
+ *     ary.bsearch_index {|x| block }  -> int or nil
+ *
+ *  By using binary search, finds an index of a value from this array which
+ *  meets the given condition in O(log n) where n is the size of the array.
+ *
+ *  It supports two modes, depending on the nature of the block. They are
+ *  exactly the same as in the case of the #bsearch method, with the only difference
+ *  being that this method returns the index of the element instead of the
+ *  element itself. For more details consult the documentation for #bsearch.
+ */
 
-	beg = NUM2INT(arg1);
-	if (TYPE(arg3) != T_ARRAY) {
-	    arg3 = (struct RArray*)rb_to_a(arg3);
+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 */
 	}
-	if (beg < 0) {
-	    beg = ary->len + beg;
-	    if (beg < 0) {
-		Fail("negative index for array(size: %d)", ary->len);
-	    }
+	else if (v == Qtrue) {
+	    satisfied = 1;
+	    smaller = 1;
+	}
+	else if (v == Qfalse || v == Qnil) {
+	    smaller = 0;
 	}
-	if (beg >= ary->len) {
-	    len = beg + arg3->len;
-	    if (len >= ary->capa) {
-		ary->capa=len;
-		REALLOC_N(ary->ptr, VALUE, ary->capa);
+	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;
 	    }
-	    MEMZERO(ary->ptr+ary->len, VALUE, beg-ary->len);
-	    MEMCPY(ary->ptr+beg, arg3->ptr, VALUE, arg3->len);
-	    ary->len = len;
 	}
 	else {
-	    int alen;
+	    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);
+}
 
-	    len = NUM2INT(arg2);
-	    if (beg + len > ary->len) {
-		len = ary->len - beg;
-	    }
-	    if (len < 0) {
-		Fail("negative length for sub-array(size: %d)", ary->len);
+
+static VALUE
+sort_by_i(RB_BLOCK_CALL_FUNC_ARGLIST(i, dummy))
+{
+    return rb_yield(i);
+}
+
+/*
+ *  call-seq:
+ *     ary.sort_by! {|obj| block}      -> ary
+ *     ary.sort_by!                    -> Enumerator
+ *
+ *  Sorts +self+ in place using a set of keys generated by mapping the
+ *  values in +self+ through the given block.
+ *
+ *  The result is not guaranteed to be stable.  When two keys are equal,
+ *  the order of the corresponding elements is unpredictable.
+ *
+ *  If no block is given, an Enumerator is returned instead.
+ *
+ *  See also Enumerable#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:
+ *     ary.collect {|item| block}    -> new_ary
+ *     ary.map     {|item| block}    -> new_ary
+ *     ary.collect                   -> Enumerator
+ *     ary.map                       -> Enumerator
+ *
+ *  Invokes the given block once for each element of +self+.
+ *
+ *  Creates a new array containing the values returned by the block.
+ *
+ *  See also Enumerable#collect.
+ *
+ *  If no block is given, an Enumerator is returned instead.
+ *
+ *     a = [ "a", "b", "c", "d" ]
+ *     a.collect {|x| x + "!"}           #=> ["a!", "b!", "c!", "d!"]
+ *     a.map.with_index {|x, i| x * i}   #=> ["", "b", "cc", "ddd"]
+ *     a                                 #=> ["a", "b", "c", "d"]
+ */
+
+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:
+ *     ary.collect! {|item| block }   -> ary
+ *     ary.map!     {|item| block }   -> ary
+ *     ary.collect!                   -> Enumerator
+ *     ary.map!                       -> Enumerator
+ *
+ *  Invokes the given block once for each element of +self+, replacing the
+ *  element with the value returned by the block.
+ *
+ *  See also Enumerable#collect.
+ *
+ *  If no block is given, an Enumerator is returned instead.
+ *
+ *     a = [ "a", "b", "c", "d" ]
+ *     a.map! {|x| x + "!" }
+ *     a #=>  [ "a!", "b!", "c!", "d!" ]
+ *     a.collect!.with_index {|x, i| x[0...i] }
+ *     a #=>  ["", "b", "c!", "d!"]
+ */
+
+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
+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;
+}
 
-	    alen = ary->len + arg3->len - len;
-	    if (alen >= ary->capa) {
-		ary->capa=alen;
-		REALLOC_N(ary->ptr, VALUE, ary->capa);
+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:
+ *     ary.values_at(selector, ...)  -> new_ary
+ *
+ *  Returns an array containing the elements in +self+ corresponding to the
+ *  given +selector+(s).
+ *
+ *  The selectors may be either integer indices or ranges.
+ *
+ *  See also Array#select.
+ *
+ *     a = %w{ a b c d e f }
+ *     a.values_at(1, 3, 5)          # => ["b", "d", "f"]
+ *     a.values_at(1, 3, 5, 7)       # => ["b", "d", "f", nil]
+ *     a.values_at(-1, -2, -2, -7)   # => ["f", "e", "e", nil]
+ *     a.values_at(4..6, 3...6)      # => ["e", "f", nil, "d", "e", "f"]
+ */
+
+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;
+}
+
 
-	    memmove(ary->ptr+beg+arg3->len, ary->ptr+beg+len,
-		    sizeof(VALUE)*(ary->len-(beg+len)));
-	    memcpy(ary->ptr+beg, arg3->ptr, sizeof(VALUE)*arg3->len);
-	    ary->len = alen;
+/*
+ *  call-seq:
+ *     ary.select {|item| block}   -> new_ary
+ *     ary.select                  -> Enumerator
+ *     ary.filter {|item| block}   -> new_ary
+ *     ary.filter                  -> Enumerator
+ *
+ *  Returns a new array containing all elements of +ary+
+ *  for which the given +block+ returns a true value.
+ *
+ *  If no block is given, an Enumerator is returned instead.
+ *
+ *     [1,2,3,4,5].select {|num| num.even? }     #=> [2, 4]
+ *
+ *     a = %w[ a b c d e f ]
+ *     a.select {|v| v =~ /[aeiou]/ }    #=> ["a", "e"]
+ *
+ *  See also Enumerable#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 (VALUE)arg3;
     }
+    return result;
+}
 
-    /* check if idx is Range */
-    if (obj_is_kind_of(arg1, C_Range)) {
-	int beg, len;
+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:
+ *     ary.select! {|item| block } -> ary or nil
+ *     ary.select!                 -> Enumerator
+ *     ary.filter! {|item| block } -> ary or nil
+ *     ary.filter!                 -> Enumerator
+ *
+ *  Invokes the given block passing in successive elements from +self+,
+ *  deleting elements for which the block returns a +false+ value.
+ *
+ *  The array may not be changed instantly every time the block is called.
+ *
+ *  If changes were made, it will return +self+, otherwise it returns +nil+.
+ *
+ *  If no block is given, an Enumerator is returned instead.
+ *
+ *  See also Array#keep_if.
+ *
+ *  Array#filter! is an alias for Array#select!.
+ */
+
+static VALUE
+rb_ary_select_bang(VALUE 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:
+ *     ary.keep_if {|item| block}   -> ary
+ *     ary.keep_if                  -> Enumerator
+ *
+ *  Deletes every element of +self+ for which the given block evaluates to
+ *  +false+, and returns +self+.
+ *
+ *  If no block is given, an Enumerator is returned instead.
+ *
+ *     a = %w[ a b c d e f ]
+ *     a.keep_if {|v| v =~ /[aeiou]/ }    #=> ["a", "e"]
+ *     a                                  #=> ["a", "e"]
+ *
+ *  See also Array#select!.
+ */
+
+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:
+ *     ary.delete(obj)            -> item or nil
+ *     ary.delete(obj) {block}    -> item or result of block
+ *
+ *  Deletes all items from +self+ that are equal to +obj+.
+ *
+ *  Returns the last deleted item, or +nil+ if no matching item is found.
+ *
+ *  If the optional code block is given, the result of the block is returned if
+ *  the item is not found.  (To remove +nil+ elements and get an informative
+ *  return value, use Array#compact!)
+ *
+ *     a = [ "a", "b", "b", "b", "c" ]
+ *     a.delete("b")                   #=> "b"
+ *     a                               #=> ["a", "c"]
+ *     a.delete("z")                   #=> nil
+ *     a.delete("z") {"not found"}     #=> "not found"
+ */
+
+VALUE
+rb_ary_delete(VALUE ary, VALUE item)
+{
+    VALUE v = item;
+    long i1, i2;
+
+    for (i1 = i2 = 0; i1 < RARRAY_LEN(ary); i1++) {
+	VALUE e = RARRAY_AREF(ary, i1);
+
+	if (rb_equal(e, item)) {
+	    v = e;
+	    continue;
+	}
+	if (i1 != i2) {
+	    rb_ary_store(ary, i2, e);
+	}
+	i2++;
+    }
+    if (RARRAY_LEN(ary) == i2) {
+	if (rb_block_given_p()) {
+	    return rb_yield(item);
+	}
+	return Qnil;
+    }
+
+    ary_resize_smaller(ary, i2);
+
+    ary_verify(ary);
+    return v;
+}
+
+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) {
+	    rb_ary_store(ary, i2, e);
+	}
+	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:
+ *     ary.delete_at(index)  -> obj or nil
+ *
+ *  Deletes the element at the specified +index+, returning that element, or
+ *  +nil+ if the +index+ is out of range.
+ *
+ *  See also Array#slice!
+ *
+ *     a = ["ant", "bat", "cat", "dog"]
+ *     a.delete_at(2)    #=> "cat"
+ *     a                 #=> ["ant", "bat", "dog"]
+ *     a.delete_at(99)   #=> nil
+ */
+
+static VALUE
+rb_ary_delete_at_m(VALUE ary, VALUE pos)
+{
+    return rb_ary_delete_at(ary, NUM2LONG(pos));
+}
+
+/*
+ *  call-seq:
+ *     ary.slice!(index)         -> obj or nil
+ *     ary.slice!(start, length) -> new_ary or nil
+ *     ary.slice!(range)         -> new_ary or nil
+ *
+ *  Deletes the element(s) given by an +index+ (optionally up to +length+
+ *  elements) or by a +range+.
+ *
+ *  Returns the deleted object (or objects), or +nil+ if the +index+ is out of
+ *  range.
+ *
+ *     a = [ "a", "b", "c" ]
+ *     a.slice!(1)     #=> "b"
+ *     a               #=> ["a", "c"]
+ *     a.slice!(-1)    #=> "c"
+ *     a               #=> ["a"]
+ *     a.slice!(100)   #=> nil
+ *     a               #=> ["a"]
+ */
+
+static VALUE
+rb_ary_slice_bang(int argc, VALUE *argv, VALUE ary)
+{
+    VALUE arg1, arg2;
+    long pos, len, orig_len;
+
+    rb_ary_modify_check(ary);
+    if (argc == 2) {
+	pos = NUM2LONG(argv[0]);
+	len = NUM2LONG(argv[1]);
+      delete_pos_len:
+	if (len < 0) return Qnil;
+	orig_len = RARRAY_LEN(ary);
+	if (pos < 0) {
+	    pos += orig_len;
+	    if (pos < 0) return Qnil;
+	}
+	else if (orig_len < pos) return Qnil;
+	if (orig_len < pos + len) {
+	    len = orig_len - pos;
+	}
+	if (len == 0) return rb_ary_new2(0);
+        arg2 = rb_ary_new4(len, RARRAY_CONST_PTR_TRANSIENT(ary)+pos);
+	RBASIC_SET_CLASS(arg2, rb_obj_class(ary));
+	rb_ary_splice(ary, pos, len, 0, 0);
+	return arg2;
+    }
+
+    rb_check_arity(argc, 1, 2);
+    arg1 = argv[0];
+
+    if (!FIXNUM_P(arg1)) {
+	switch (rb_range_beg_len(arg1, &pos, &len, RARRAY_LEN(ary), 0)) {
+	  case Qtrue:
+	    /* valid range */
+	    goto delete_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
+reject_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
+ary_reject_bang(VALUE ary)
+{
+    struct select_bang_arg args;
+    rb_ary_modify_check(ary);
+    args.ary = ary;
+    args.len[0] = args.len[1] = 0;
+    return rb_ensure(reject_bang_i, (VALUE)&args, select_bang_ensure, (VALUE)&args);
+}
+
+/*
+ *  call-seq:
+ *     ary.reject! {|item| block}    -> ary or nil
+ *     ary.reject!                   -> Enumerator
+ *
+ *  Deletes every element of +self+ for which the block evaluates to +true+,
+ *  if no changes were made returns +nil+.
+ *
+ *  The array may not be changed instantly every time the block is called.
+ *
+ *  See also Enumerable#reject and Array#delete_if.
+ *
+ *  If no block is given, an Enumerator is returned instead.
+ */
+
+static VALUE
+rb_ary_reject_bang(VALUE ary)
+{
+    RETURN_SIZED_ENUMERATOR(ary, 0, 0, ary_enum_length);
+    rb_ary_modify(ary);
+    return ary_reject_bang(ary);
+}
+
+/*
+ *  call-seq:
+ *     ary.reject  {|item| block }  -> new_ary
+ *     ary.reject                   -> Enumerator
+ *
+ *  Returns a new array containing the items in +self+ for which the given
+ *  block is not +true+. The ordering of non-rejected elements is maintained.
+ *
+ *  See also Array#delete_if
+ *
+ *  If no block is given, an Enumerator is returned instead.
+ */
 
-	Check_Type(arg2, T_ARRAY);
-	range_beg_end(arg1, &beg, &len, ary->len);
-	if (ary->len < beg) {
-	    len = beg + RARRAY(arg2)->len;
-	    if (len >= ary-