0 files changed, 0 insertions, 0 deletions
diff --git a/.appveyor.yml b/.appveyor.yml
deleted file mode 100644
index 8f1ece3313..0000000000
--- a/.appveyor.yml
+++ /dev/null
@@ -1,134 +0,0 @@
----
-version: '{build}'
-init:
-  - git config --global user.name git
-  - git config --global user.email svn-admin@ruby-lang.org
-  - git config --global core.autocrlf false
-  - git config --global core.eol lf
-  - git config --global advice.detachedHead 0
-shallow_clone: true
-clone_depth: 10
-platform:
-  - x64
-skip_commits:
-  message: /\[DOC\]/
-  files:
-    - doc/*
-    - '**/*.md'
-    - '**/*.rdoc'
-    - '**/.document'
-    - '**/*.[1-8]'
-    - '**/*.ronn'
-environment:
-  ruby_version: "25-%Platform%"
-  matrix:
-    # Test only the oldest supported version because AppVeyor is unstable, its concurrency
-    # is limited, and compatibility issues that happen only in newer versions are rare.
-    # You may test some other stuff on GitHub Actions instead.
-    - build: vs
-      vs: 120 # Visual Studio 2013
-      ssl: OpenSSL-v111
-      # The worker image name. This is NOT the Visual Studio version we're using here.
-      APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2015
-      GEMS_FOR_TEST: ""
-  RELINE_TEST_ENCODING: "UTF-8"
-cache:
-  - c:\Tools\vcpkg\installed\
-for:
--
-  matrix:
-    only:
-      - build: vs
-  install:
-    - ver
-    - chcp
-    - SET BITS=%Platform:x86=32%
-    - SET BITS=%BITS:x=%
-    - SET OPENSSL_DIR=C:\%ssl%-Win%BITS%
-    - cd C:\Tools\vcpkg
-    - git pull -q
-    - .\bootstrap-vcpkg.bat
-    - ps: Start-FileDownload 'https://github.com/microsoft/vcpkg-tool/releases/download/2023-08-09/vcpkg.exe' -FileName 'C:\Tools\vcpkg\vcpkg.exe'
-    - cd %APPVEYOR_BUILD_FOLDER%
-    - vcpkg --triplet %Platform%-windows install --x-use-aria2 libffi libyaml readline zlib
-    - 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% up VCSUP="echo Update OK"
-    - nmake %mflags% extract-extlibs
-    - del Makefile
-    - mkdir \usr\local\bin
-    - mkdir \usr\local\include
-    - mkdir \usr\local\lib
-    - for %%I in (%OPENSSL_DIR%\*.dll) do mklink /h \usr\local\bin\%%~nxI %%I
-    - for %%I in (c:\Tools\vcpkg\installed\%Platform%-windows\bin\*.dll) do (
-        if not %%~nI == readline mklink \usr\local\bin\%%~nxI %%I
-      )
-    - attrib +r /s /d
-    - mkdir %Platform%-mswin_%vs%
-  build_script:
-    - set HAVE_GIT=no
-    - cd %APPVEYOR_BUILD_FOLDER%
-    - cd %Platform%-mswin_%vs%
-    - >-
-      ..\win32\configure.bat
-      --with-opt-dir="/usr/local;c:/Tools/vcpkg/installed/%Platform%-windows"
-      --with-openssl-dir=%OPENSSL_DIR:\=/%
-    - nmake -l
-    - nmake install-nodoc
-    - \usr\bin\ruby -v -e "p :locale => Encoding.find('locale'), :filesystem => Encoding.find('filesystem')"
-    - if not "%GEMS_FOR_TEST%" == "" \usr\bin\gem install --no-document %GEMS_FOR_TEST%
-    - \usr\bin\ruby -ropenssl -e "puts 'Build    ' + OpenSSL::OPENSSL_VERSION, 'Runtime  ' + OpenSSL::OPENSSL_LIBRARY_VERSION"
-  test_script:
-    - set /a JOBS=%NUMBER_OF_PROCESSORS%
-    - nmake -l "TESTOPTS=-v -q" btest
-    - nmake -l "TESTOPTS=-v -q" test-basic
-    - >-
-      nmake -l "TESTOPTS=--timeout-scale=3.0
-      --excludes=../test/.excludes/_appveyor -j%JOBS%
-      --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=--timeout-scale=3.0 --excludes=../test/.excludes/_appveyor"
-      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
-      " test-all
-    - nmake -l test-spec # not using `-j` because sometimes `mspec -j` silently dies on Windows
-notifications:
-  - provider: Webhook
-    method: POST
-    url:
-      secure: CcFlJNDJ/a6to7u3Z4Fnz6dScEPNx7hTha2GkSRlV+1U6dqmxY/7uBcLXYb9gR3jfQk6w+2o/HrjNAyXMNGU/JOka3s2WRI4VKitzM+lQ08owvJIh0R7LxrGH0J2e81U # ruby-lang slack: ruby/simpler-alerts-bot
-    body: >-
-      {{^isPullRequest}}
-        {
-          "ci": "AppVeyor CI",
-          "env": "Visual Studio 2013",
-          "url": "{{buildUrl}}",
-          "commit": "{{commitId}}",
-          "branch": "{{branch}}"
-        }
-      {{/isPullRequest}}
-    on_build_success: false
-    on_build_failure: true
-    on_build_status_changed: false
diff --git a/.document b/.document
index e875e42546..753d6f9892 100644
--- a/.document
+++ b/.document
@@ -15,13 +15,14 @@ array.rb
 ast.rb
 dir.rb
 gc.rb
+hash.rb
 io.rb
 kernel.rb
 marshal.rb
-rjit.rb
 numeric.rb
 nilclass.rb
 pack.rb
+pathname_builtin.rb
 ractor.rb
 string.rb
 symbol.rb
@@ -30,6 +31,10 @@ thread_sync.rb
 trace_point.rb
 warning.rb
 yjit.rb
+zjit.rb
+
+# Errno::*
+known_errors.inc
 
 # the lib/ directory (which has its own .document file)
 lib
@@ -37,6 +42,9 @@ lib
 # and some of the ext/ directory (which has its own .document file)
 ext
 
+# For `prism`, ruby code is in lib and c in the prism folder
+prism
+
 # rdoc files
 NEWS.md
 
diff --git a/.gdbinit b/.gdbinit
index 7dd3336e28..4457f6f12b 100644
--- a/.gdbinit
+++ b/.gdbinit
@@ -1,23 +1,7 @@
-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
+  init-if-undefined $color_type = "\033[31m"
+  init-if-undefined $color_highlite = "\033[36m"
+  init-if-undefined $color_end = "\033[m"
 end
 
 # set prompt \033[36m(gdb)\033[m\040
@@ -67,7 +51,7 @@ define rp
     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) @ (rb_shape_get_shape($arg0)->capacity)
+      print/x *((VALUE*)((struct RObject*)($arg0))->as.ary) @ (RSHAPE_CAPACITY(rb_obj_shape_id($arg0)))
     else
       print (((struct RObject *)($arg0))->as.heap)
       if (((struct RObject*)($arg0))->as.heap.numiv) > 0
@@ -99,13 +83,11 @@ define rp
     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 $len = ((struct RString*)($arg0))->len
     set print address off
     output *(char *)(($rsflags & RUBY_FL_USER1) ? \
             ((struct RString*)$regsrc)->as.heap.ptr : \
-            ((struct RString*)$regsrc)->as.ary) @ $len
+            ((struct RString*)$regsrc)->as.embed.ary) @ $len
     set print address on
     printf " len:%ld ", $len
     if $flags & RUBY_FL_USER6
@@ -157,13 +139,15 @@ define rp
   if ($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
+      set $st = (struct st_table *)((uintptr_t)($arg0) + sizeof(struct RHash))
+      printf "st len=%ld ", $st->num_entries
+      print $st
     else
       printf "li len=%ld bound=%ld ", \
         ((((struct RHash *)($arg0))->basic.flags & RHASH_AR_TABLE_SIZE_MASK) >> RHASH_AR_TABLE_SIZE_SHIFT), \
         ((((struct RHash *)($arg0))->basic.flags & RHASH_AR_TABLE_BOUND_MASK) >> RHASH_AR_TABLE_BOUND_SHIFT)
+	print (struct ar_table_struct *)((uintptr_t)($arg0) + sizeof(struct RHash))
     end
-    print (struct RHash *)($arg0)
   else
   if ($flags & RUBY_T_MASK) == RUBY_T_STRUCT
     set $len = (($flags & (RUBY_FL_USER1|RUBY_FL_USER2)) ? \
@@ -201,12 +185,14 @@ define rp
     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)
+    set $data = (struct RTypedData *)($arg0)
+    set $type = (const rb_data_type_t *)($data->type & ~1)
+    printf "%sT_DATA%s(%s): ", $color_type, $color_end, $type->wrap_struct_name
+    print *$type
+    if ($data->type & 1)
+      print (void *)&$data->data
     else
-      printf "%sT_DATA%s: ", $color_type, $color_end
-      print (struct RData *)($arg0)
+      print $data
     end
   else
   if ($flags & RUBY_T_MASK) == RUBY_T_MATCH
@@ -440,13 +426,11 @@ 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)
+  set $len = ((struct RString*)($arg0))->len
   if $len > 0
     output *(char *)(($flags & RUBY_FL_USER1) ? \
             ((struct RString*)($arg0))->as.heap.ptr : \
-            ((struct RString*)($arg0))->as.ary) @ $len
+            ((struct RString*)($arg0))->as.embed.ary) @ $len
   else
     output ""
   end
@@ -454,13 +438,11 @@ 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)
+  set $len = ((struct RString*)($arg0))->len
   if $len > 0
     printf "%s", *(char *)(($flags & RUBY_FL_USER1) ? \
             ((struct RString*)($arg0))->as.heap.ptr : \
-            ((struct RString*)($arg0))->as.ary) @ $len
+            ((struct RString*)($arg0))->as.embed.ary) @ $len
   end
 end
 
@@ -543,14 +525,14 @@ document rp_bignum
 end
 
 define rp_class
+  set $class_and_classext = (struct RClass_and_rb_classext_t *)($arg0)
   printf "(struct RClass *) %p", (void*)$arg0
-  if RCLASS_ORIGIN((struct RClass *)($arg0)) != $arg0
-    printf " -> %p", RCLASS_ORIGIN((struct RClass *)($arg0))
+  if $class_and_classext->classext->origin_ != (VALUE)$arg0
+    printf " -> %p", $class_and_classext->classext->origin_
   end
   printf "\n"
   rb_classname $arg0
-  print/x *(struct RClass *)($arg0)
-  print *RCLASS_EXT((struct RClass *)($arg0))
+  print/x *$class_and_classext
 end
 document rp_class
   Print the content of a Class/Module.
@@ -916,10 +898,10 @@ document rb_method_entry
 end
 
 define rb_classname
-  # up to 128bit int
-  set $rb_classname = rb_mod_name($arg0)
-  if $rb_classname != RUBY_Qnil
-    rp $rb_classname
+  set $rb_classname = ((struct RClass_and_rb_classext_t*)$arg0)->classext->classpath
+  if $rb_classname != RUBY_Qfalse
+    print_string $rb_classname
+    printf "\n"
   else
     echo anonymous class/module\n
   end
@@ -992,7 +974,7 @@ end
 
 define print_lineno
   set $cfp = $arg0
-  set $iseq = $cfp->iseq
+  set $iseq = rb_get_cfp_iseq($cfp)
   set $pos = $cfp->pc - $iseq->body->iseq_encoded
   if $pos != 0
     set $pos = $pos - 1
@@ -1073,7 +1055,7 @@ define print_id
   else
     set $serial = (rb_id_serial_t)$id
   end
-  if $serial && $serial <= ruby_global_symbols.last_id
+  if $serial && $serial < ruby_global_symbols.next_id
     set $idx = $serial / ID_ENTRY_UNIT
     set $ids = (struct RArray *)ruby_global_symbols.ids
     set $flags = $ids->basic.flags
@@ -1096,7 +1078,7 @@ define print_id
           set $aryptr = $ary->as.heap.ptr
           set $arylen = $ary->as.heap.len
         end
-        set $result = $aryptr[($serial % ID_ENTRY_UNIT) * ID_ENTRY_SIZE + $t]
+        set $result = $aryptr[($serial % ID_ENTRY_UNIT) + $t]
         if $result != RUBY_Qnil
           print_string $result
         else
@@ -1126,20 +1108,21 @@ 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
+    $ps_thread, $ps_thread_th, $ps_thread_th->nt
   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))
+    if $cfp->_iseq
+      set $iseq = rb_get_cfp_iseq($cfp)
+      if !((VALUE)$iseq & RUBY_IMMEDIATE_MASK) && (((imemo_ifunc << RUBY_FL_USHIFT) | RUBY_T_IMEMO)==$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
+        output/a $iseq.body
         set print symbol-filename off
         printf "\n"
       else
       if $cfp->pc
-        set $location = $cfp->iseq->body->location
+        set $location = $iseq->body->location
         printf "%d:", $cfpend-$cfp
         print_pathobj $location.pathobj
         printf ":"
@@ -1311,13 +1294,12 @@ define dump_node
   set $flags = ((struct RBasic*)($str))->flags
   printf "%s", (char *)(($flags & RUBY_FL_USER1) ? \
                         ((struct RString*)$str)->as.heap.ptr : \
-                        ((struct RString*)$str)->as.ary)
+                        ((struct RString*)$str)->as.embed.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*)($arg0))->flags & RUBY_FL_PROMOTED1 ? "1" : "0"
+  printf "RUBY_FL_PROMOTED    : %s\n", ((struct RBasic*)($arg0))->flags & RUBY_FL_PROMOTED ? "1" : "0"
   printf "RUBY_FL_FINALIZE    : %s\n", ((struct RBasic*)($arg0))->flags & RUBY_FL_FINALIZE ? "1" : "0"
   printf "RUBY_FL_SHAREABLE   : %s\n", ((struct RBasic*)($arg0))->flags & RUBY_FL_SHAREABLE ? "1" : "0"
   printf "RUBY_FL_EXIVAR      : %s\n", ((struct RBasic*)($arg0))->flags & RUBY_FL_EXIVAR ? "1" : "0"
@@ -1344,4 +1326,7 @@ define print_flags
   printf "RUBY_FL_USER18      : %s\n", ((struct RBasic*)($arg0))->flags & RUBY_FL_USER18 ? "1" : "0"
 end
 
-source misc/gdb.py
+source -s misc/gdb.py
+
+# Moved from beginning, since it fails on older gdbs
+set startup-with-shell off
diff --git a/.git-blame-ignore-revs b/.git-blame-ignore-revs
index 1bf7db40ad..d752612085 100644
--- a/.git-blame-ignore-revs
+++ b/.git-blame-ignore-revs
@@ -6,6 +6,15 @@
 # Expand tabs
 5b21e94bebed90180d8ff63dad03b8b948361089
 c5e9af9c9d890578182a21e7b71b50334cd5579e
+e63a2115f64433b21cb5dd67c5bf8b30f87ef293
+712ac99e4d0384a941c80a9f48f62943ba7d97c0
+d1474affa8e105bece209cc9d594bb0a989859e1
+2da92388b948821269b18d6b178a680f17e41750
+5062c0c621d887367af8a054e5e5d83d7ec57dd3
+
+# Indentation
+0e4bad888e605d424b9222ae0ca43f85c1634e5e
+61aa46c41648c6d1e9b0daa1a292de551fde78df
 
 # Enable Style/StringLiterals cop for RubyGems/Bundler
 d7ffd3fea402239b16833cc434404a7af82d44f3
@@ -26,3 +35,20 @@ fc4acf8cae82e5196186d3278d831f2438479d91
 # Make prism_compile.c indentation consistent
 40b2c8e5e7e6e5f83cee9276dc9c1922a69292d6
 d2c5867357ed88eccc28c2b3bd4a46e206e7ff85
+
+# Miss-and-revived commits
+a0f7de814ae5c299d6ce99bed5fb308a05d50ba0
+d4e24021d39e1f80f0055b55d91f8d5f22e15084
+7a56c316418980b8a41fcbdc94067b2bda2ad112
+e90282be7ba1bc8e3119f6e1a2c80356ceb3f80a
+26a9e0b4e31f7b5a9cbd755e0a15823a8fa51bae
+2f53985da9ee593fe524d408256835667938c7d7
+bf01f6ae89a95d8f5572e050facfe311c8c28aaf
+7480cd8d37fd71a41ce12b759090051c7e14fb5a
+
+# Win32: EOL code of batch files
+23f9a0d655c4d405bb2397a147a1523436205486
+b839989fd22fef85e2af19de1bc83aa72a5b22bd
+
+# ZJIT cargo-insta snapshot raw string literals
+b78e0a6ddf7df8a7568ea71284f593423c739551
diff --git a/.gitattributes b/.gitattributes
index d0c2d266b4..f98c091e3f 100644
--- a/.gitattributes
+++ b/.gitattributes
@@ -1,8 +1,14 @@
 *.gemspec diff=ruby
 *.rb diff=ruby
+*.inc.rs linguist-generated=true
 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
+
+# To strip CR from the batch files, set the `diff.dos.textconv` filter
+# like as `git config diff.dos.textconv $'sed \'s/\r$//\''`.
+*.bat diff=dos
+*.cmd diff=dos
diff --git a/.github/actions/capiext/action.yml b/.github/actions/capiext/action.yml
new file mode 100644
index 0000000000..ed69c8ac5e
--- /dev/null
+++ b/.github/actions/capiext/action.yml
@@ -0,0 +1,86 @@
+name: rubyspec C-API extensions
+
+inputs:
+  builddir:
+    required: false
+    default: '.'
+  make:
+    required: false
+    default: 'make -s'
+
+outputs:
+  key:
+    value: >-
+      ${{
+      !steps.restore.outputs.cache-hit &&
+      github.ref == 'refs/heads/master' &&
+      steps.config.outputs.key
+      }}
+
+runs:
+  using: composite
+
+  steps:
+    - id: config
+      shell: bash
+      run: |
+        eval $(grep -e '^arch *=' -e '^ruby_version *=' -e '^DLEXT *=' Makefile |
+            sed 's/ *= */=/')
+        case "${ruby_version}" in
+        *+*) key=capiexts-${arch}-${ruby_version}-${{ hashFiles('src/spec/ruby/optional/capi/ext/*.[ch]') }};;
+        *)   key=;;
+        esac
+        echo version=$ruby_version >> $GITHUB_OUTPUT
+        echo key="$key" >> $GITHUB_OUTPUT
+        echo DLEXT=$DLEXT >> $GITHUB_OUTPUT
+      working-directory: ${{ inputs.builddir }}
+
+    - name: Restore previous CAPI extensions
+      uses: actions/cache/restore@0400d5f644dc74513175e3cd8d07132dd4860809 # v4.2.4
+      id: cache
+      with:
+        path: ${{ inputs.builddir }}/spec/ruby/optional/capi/ext/
+        key: ${{ steps.config.outputs.key }}
+      if: ${{ steps.config.outputs.key }}
+
+    - name: Run test-spec with previous CAPI extension binaries
+      id: check
+      shell: bash
+      run: | # zizmor: ignore[template-injection]
+        touch spec/ruby/optional/capi/ext/*.$DLEXT
+        [ ! -f spec/ruby/optional/capi/ext/\*.$DLEXT ]
+        ${{ inputs.make }} SPECOPTS=optional/capi test-spec
+      env:
+        DLEXT: ${{ steps.config.outputs.DLEXT }}
+      working-directory: ${{ inputs.builddir }}
+      if: ${{ steps.cache.outputs.cache-hit }}
+
+    - name: Strip CAPI extensions
+      id: strip
+      shell: bash
+      run: |
+        rm -f spec/ruby/optional/capi/ext/*.c
+        [ "$DLEXT" = bundle ] || # separated to .dSYM directories
+        strip spec/ruby/optional/capi/ext/*.$DLEXT
+      env:
+        DLEXT: ${{ steps.config.outputs.DLEXT }}
+      working-directory: ${{ inputs.builddir }}
+      if: >-
+        ${{true
+        && ! steps.cache.outputs.cache-hit
+        && github.ref_name == 'master'
+        }}
+
+    - name: Save CAPI extensions
+      uses: actions/cache/save@0400d5f644dc74513175e3cd8d07132dd4860809 # v4.2.4
+      with:
+        path: ${{ inputs.builddir }}/spec/ruby/optional/capi/ext/
+        key: ${{ steps.config.outputs.key }}
+      if: ${{ steps.strip.outcome == 'success' }}
+
+    - shell: bash
+      run: |
+        echo "::error::Change from ${prev} detected; bump up ABI version"
+      env:
+        prev: ${{ steps.config.outputs.version }}
+      if: ${{ always() && steps.check.outcome == 'failure' }}
diff --git a/.github/actions/compilers/action.yml b/.github/actions/compilers/action.yml
new file mode 100644
index 0000000000..c700bbfe9e
--- /dev/null
+++ b/.github/actions/compilers/action.yml
@@ -0,0 +1,164 @@
+name: Compiles ruby in a container
+description: >-
+  Makes ruby using a dedicated container
+
+inputs:
+  tag:
+    required: false
+    default: clang-20
+    description: >-
+      container image tag to use in this run.
+
+  with_gcc:
+    required: false
+    description: >-
+      override compiler path & flags.
+
+  CFLAGS:
+    required: false
+    description: >-
+      C compiler flags to override.
+
+  CXXFLAGS:
+    required: false
+    description: >-
+      C++ compiler flags to override.
+
+  optflags:
+    required: false
+    # -O1 is faster than -O3 in our tests... Majority of time are consumed trying
+    # to optimize binaries.  Also GitHub Actions run on relatively modern CPUs
+    # compared to, say, GCC 4 or Clang 3.  We don't specify `-march=native`
+    # because compilers tend not understand what the CPU is.
+    default: '-O1'
+    description: >-
+      Compiler flags for optimisations.
+
+  cppflags:
+    required: false
+    description: >-
+      Additional preprocessor flags.
+
+  append_configure:
+    required: false
+    default: >-
+      --without-valgrind
+      --without-jemalloc
+      --without-gmp
+    description: >-
+      flags to append to configure.
+
+  enable_shared:
+    required: false
+    default: true
+    description: >-
+      Whether to build libruby.so.
+
+  check:
+    required: false
+    default: ''
+    description: >-
+      Whether to run `make check`
+
+  test_all:
+    required: false
+    default: ''
+    description: >-
+      Whether to run `make test-all` with options for test-all.
+
+  test_spec:
+    required: false
+    default: ''
+    description: >-
+      Whether to run `make test-spec` with options for mspec.
+
+  static_exts:
+    required: false
+    description: >-
+      whitespace separated list of extensions that need be linked statically.
+
+runs:
+  using: composite
+  steps:
+    - shell: bash
+      run: docker pull --quiet "ghcr.io/ruby/ruby-ci-image:${INPUT_TAG}"
+      env:
+        INPUT_TAG: ${{ inputs.tag }}
+
+    - name: Enable Launchable conditionally
+      id: enable-launchable
+      run: echo "enable-launchable=true" >> $GITHUB_OUTPUT
+      shell: bash
+      if: >-
+        ${{
+        github.repository == 'ruby/ruby' ||
+        (github.repository != 'ruby/ruby' && env.LAUNCHABLE_TOKEN)
+        }}
+
+    - name: compile
+      shell: bash
+      run: >-
+        docker run
+        --rm
+        --user=root
+        --volume "${GITHUB_WORKSPACE}:/github/workspace:ro"
+        --workdir=/github/workspace
+        --entrypoint=/github/workspace/.github/actions/compilers/entrypoint.sh
+        --env CI
+        --env GITHUB_ACTION
+        --env INPUT_WITH_GCC
+        --env INPUT_CFLAGS
+        --env INPUT_CXXFLAGS
+        --env INPUT_OPTFLAGS
+        --env INPUT_CPPFLAGS
+        --env INPUT_APPEND_CONFIGURE
+        --env INPUT_CHECK
+        --env INPUT_TEST_ALL
+        --env INPUT_TEST_SPEC
+        --env INPUT_ENABLE_SHARED
+        --env INPUT_STATIC_EXTS
+        --env LAUNCHABLE_ORGANIZATION
+        --env LAUNCHABLE_WORKSPACE
+        --env LAUNCHABLE_ENABLED
+        --env GITHUB_PR_HEAD_SHA
+        --env GITHUB_PULL_REQUEST_URL
+        --env GITHUB_REF
+        --env GITHUB_ACTIONS
+        --env GITHUB_RUN_ID
+        --env GITHUB_REPOSITORY
+        --env GITHUB_WORKFLOW
+        --env GITHUB_RUN_NUMBER
+        --env GITHUB_EVENT_NAME
+        --env GITHUB_SHA
+        --env GITHUB_HEAD_REF
+        --env GITHUB_SERVER_URL
+        "ghcr.io/ruby/ruby-ci-image:${INPUT_TAG}"
+      env:
+        INPUT_TAG: ${{ inputs.tag }}
+        INPUT_WITH_GCC: ${{ inputs.with_gcc || inputs.tag }}
+        INPUT_CFLAGS: ${{ inputs.CFLAGS }}
+        INPUT_CXXFLAGS: ${{ inputs.CXXFLAGS }}
+        INPUT_OPTFLAGS: ${{ inputs.OPTFLAGS }}
+        INPUT_CPPFLAGS: ${{ inputs.cppflags }}
+        INPUT_APPEND_CONFIGURE: ${{ inputs.append_configure }}
+        INPUT_CHECK: ${{ inputs.check }}
+        INPUT_TEST_ALL: ${{ inputs.test_all }}
+        INPUT_TEST_SPEC: ${{ inputs.test_spec }}
+        INPUT_ENABLE_SHARED: ${{ inputs.enable_shared }}
+        INPUT_STATIC_EXTS: ${{ inputs.static_exts }}
+        LAUNCHABLE_ORGANIZATION: ${{ github.repository_owner }}
+        LAUNCHABLE_WORKSPACE: ${{ github.event.repository.name }}
+        LAUNCHABLE_ENABLED: ${{ steps.enable-launchable.outputs.enable-launchable || false }}
+        GITHUB_PR_HEAD_SHA: ${{ github.event.pull_request.head.sha || github.sha }}
+        GITHUB_PULL_REQUEST_URL: ${{ github.event.pull_request.html_url }}
+        GITHUB_REF: ${{ github.ref }}
+
+    # Clean up non-default docker images to save disk space.
+    # The default image (clang-20) is reused across multiple steps
+    # within the same job, so we keep it to avoid redundant pulls.
+    - name: clean up docker image
+      shell: bash
+      run: docker rmi "ghcr.io/ruby/ruby-ci-image:${INPUT_TAG}" || true
+      if: ${{ always() && inputs.tag != 'clang-20' }}
+      env:
+        INPUT_TAG: ${{ inputs.tag }}
diff --git a/.github/actions/compilers/entrypoint.sh b/.github/actions/compilers/entrypoint.sh
new file mode 100755
index 0000000000..b554151091
--- /dev/null
+++ b/.github/actions/compilers/entrypoint.sh
@@ -0,0 +1,90 @@
+#! /bin/bash
+
+# Copyright (c) 2024 Ruby developers.  All rights reserved.
+#
+# This file is  a part of the programming language  Ruby.  Permission is hereby
+# granted, to  either redistribute and/or  modify this file, provided  that the
+# conditions  mentioned in  the file  COPYING are  met.  Consult  the file  for
+# details.
+
+grouped()
+{
+    echo "::group::${@}"
+    "${@}"
+    echo "::endgroup::"
+}
+
+set -e
+set -u
+set -o pipefail
+
+srcdir="/github/workspace/src"
+builddir="$(mktemp -dt)"
+
+export GITHUB_WORKFLOW='Compilations'
+export CONFIGURE_TTY='never'
+export RUBY_DEBUG='ci rgengc'
+export RUBY_TESTOPTS='-q --color=always --tty=no'
+export RUBY_DEBUG_COUNTER_DISABLE='1'
+export GNUMAKEFLAGS="-j$((1 + $(nproc)))"
+
+case "x${INPUT_ENABLE_SHARED}" in
+x | xno | xfalse )
+    enable_shared='--disable-shared'
+    ;;
+*)
+    enable_shared='--enable-shared'
+    ;;
+esac
+
+pushd ${builddir}
+
+grouped git config --global --add safe.directory ${srcdir}
+
+grouped ${srcdir}/configure        \
+    -C                             \
+    --with-gcc="${INPUT_WITH_GCC}" \
+    --enable-debug-env             \
+    --disable-install-doc          \
+    --with-ext=-test-/cxxanyargs,+ \
+    --without-git                  \
+    ${enable_shared}               \
+    ${INPUT_APPEND_CONFIGURE}      \
+    CFLAGS="${INPUT_CFLAGS}"       \
+    CXXFLAGS="${INPUT_CXXFLAGS}"   \
+    optflags="${INPUT_OPTFLAGS}"   \
+    cppflags="${INPUT_CPPFLAGS}"   \
+    debugflags='-ggdb3' # -g0 disables backtraces when SEGV.  Do not set that.
+
+popd
+
+if [[ -n "${INPUT_STATIC_EXTS}" ]]; then
+    echo "::group::ext/Setup"
+    set -x
+    mkdir ${builddir}/ext
+    (
+        for ext in ${INPUT_STATIC_EXTS}; do
+            echo "${ext}"
+        done
+    ) >> ${builddir}/ext/Setup
+    set +x
+    echo "::endgroup::"
+fi
+
+if [ -n "$INPUT_TEST_ALL" ]; then
+  tests=" -- $INPUT_TEST_ALL"
+else
+  tests=" -- ruby -ext-"
+fi
+
+pushd ${builddir}
+
+grouped make showflags
+grouped make all
+# grouped make install
+
+# Run only `make test` by default. Run other tests if specified.
+grouped make test
+if [[ -n "$INPUT_CHECK" ]]; then grouped make test-tool; fi
+if [[ -n "$INPUT_CHECK" || -n "$INPUT_TEST_ALL" ]]; then grouped make test-all TESTS="$tests"; fi
+if [[ -n "$INPUT_CHECK" || -n "$INPUT_TEST_SPEC" ]]; then grouped env CHECK_LEAKS=true make test-spec MSPECOPT="$INPUT_TEST_SPEC"; fi
diff --git a/.github/actions/launchable/setup/action.yml b/.github/actions/launchable/setup/action.yml
new file mode 100644
index 0000000000..305878492c
--- /dev/null
+++ b/.github/actions/launchable/setup/action.yml
@@ -0,0 +1,337 @@
+name: Set up Launchable
+description: >-
+  Install the required dependencies and execute the necessary Launchable commands for test recording
+
+inputs:
+  os:
+    required: true
+    description: The operating system that CI runs on. This value is used in Launchable flavor.
+
+  test-opts:
+    default: none
+    required: false
+    description: >-
+      Test options that determine how tests are run.
+      This value is used in the Launchable flavor.
+
+  launchable-token:
+    required: false
+    description: >-
+      Launchable token is needed if you want to run Launchable on your forked repository.
+      See https://github.com/ruby/ruby/wiki/CI-Servers#launchable-ci for details.
+
+  builddir:
+    required: false
+    default: ${{ github.workspace }}
+    description: >-
+      Directory to create Launchable report file.
+
+  srcdir:
+    required: false
+    default: ${{ github.workspace }}
+    description: >-
+      Directory to (re-)checkout source codes. Launchable retrieves the commit information
+      from the directory.
+
+  test-task:
+    required: false
+    default: ${{ matrix.test_task }}
+    description: >-
+      Specifies a single test task to be executed.
+      This value is used in the Launchable flavor.
+      Either 'test-task' or 'multi-test-tasks' must be configured.
+
+  test-tasks:
+    required: false
+    default: '[]'
+    description: >-
+      Specifies an array of multiple test tasks to be executed.
+      For example: '["test", "test-all"]'.
+      If you want to run a single test task, use the 'test-task' input instead.
+
+  is-yjit:
+    required: false
+    default: 'false'
+    description: >-
+      Whether this workflow is executed on YJIT.
+
+  is-zjit:
+    required: false
+    default: 'false'
+    description: >-
+      Whether this workflow is executed on ZJIT.
+
+outputs:
+  stdout_report_path:
+    value: ${{ steps.global.outputs.stdout_report_path }}
+    description: >-
+      Report file path for standard output.
+
+  stderr_report_path:
+    value: ${{ steps.global.outputs.stderr_report_path }}
+    description: >-
+      Report file path for standard error.
+
+runs:
+  using: composite
+
+  steps:
+    - name: Enable Launchable conditionally
+      id: enable-launchable
+      run: echo "enable-launchable=true" >> $GITHUB_OUTPUT
+      shell: bash
+      if: >-
+        ${{
+        (github.repository == 'ruby/ruby'
+          || (github.repository != 'ruby/ruby'
+          && env.LAUNCHABLE_TOKEN))
+        && (inputs.test-task == 'check'
+          || inputs.test-task == 'test-all'
+          || inputs.test-task == 'test'
+          || contains(fromJSON(inputs.test-tasks), 'test-all')
+          || contains(fromJSON(inputs.test-tasks), 'test'))
+        }}
+
+    # Launchable CLI requires Python and Java.
+    # https://www.launchableinc.com/docs/resources/cli-reference/
+    - name: Set up Python
+      uses: actions/setup-python@a26af69be951a213d495a4c3e4e4022e16d87065 # v5.6.0
+      with:
+        python-version: "3.x"
+      if: >-
+        ${{ steps.enable-launchable.outputs.enable-launchable
+        && !endsWith(inputs.os, 'ppc64le') && !endsWith(inputs.os, 's390x') }}
+
+    - name: Set up Java
+      uses: actions/setup-java@c1e323688fd81a25caa38c78aa6df2d33d3e20d9 # v4.8.0
+      with:
+        distribution: 'temurin'
+        java-version: '17'
+      if: >-
+        ${{ steps.enable-launchable.outputs.enable-launchable
+        && !endsWith(inputs.os, 'ppc64le') && !endsWith(inputs.os, 's390x') }}
+
+    - name: Set up Java ppc64le
+      uses: actions/setup-java@c1e323688fd81a25caa38c78aa6df2d33d3e20d9 # v4.8.0
+      with:
+        distribution: 'semeru'
+        architecture: 'ppc64le'
+        java-version: '17'
+      if: >-
+        ${{ steps.enable-launchable.outputs.enable-launchable
+        && endsWith(inputs.os, 'ppc64le') }}
+
+    - name: Set up Java s390x
+      uses: actions/setup-java@c1e323688fd81a25caa38c78aa6df2d33d3e20d9 # v4.8.0
+      with:
+        distribution: 'semeru'
+        architecture: 's390x'
+        java-version: '17'
+      if: >-
+        ${{ steps.enable-launchable.outputs.enable-launchable
+        && endsWith(inputs.os, 's390x') }}
+
+    - name: Set global vars
+      id: global
+      shell: bash
+      run: |
+        test_all_enabled="${{ inputs.test-task == 'check' ||  inputs.test-task == 'test-all' || contains(fromJSON(inputs.test-tasks), 'test-all') }}"
+        btest_enabled="${{ inputs.test-task == 'check' ||  inputs.test-task == 'test' || contains(fromJSON(inputs.test-tasks), 'test') }}"
+        test_spec_enabled="${{ inputs.test-task == 'check' ||  inputs.test-task == 'test-spec' || contains(fromJSON(inputs.test-tasks), 'test-spec') }}"
+        echo test_all_enabled="${test_all_enabled}" >> $GITHUB_OUTPUT
+        echo btest_enabled="${btest_enabled}" >> $GITHUB_OUTPUT
+        echo test_spec_enabled="${test_spec_enabled}" >> $GITHUB_OUTPUT
+        echo test_all_report_file='launchable_test_all_report.json' >> $GITHUB_OUTPUT
+        echo btest_report_file='launchable_btest_report.json' >> $GITHUB_OUTPUT
+        echo test_spec_report_dir='launchable_test_spec_report' >> $GITHUB_OUTPUT
+        echo stdout_report_path="launchable_stdout.log" >> $GITHUB_OUTPUT
+        echo stderr_report_path="launchable_stderr.log" >> $GITHUB_OUTPUT
+      if: steps.enable-launchable.outputs.enable-launchable
+
+    - name: Set environment variables for Launchable
+      shell: bash
+      run: | # zizmor: ignore[github-env]
+        : # GITHUB_PULL_REQUEST_URL are used for commenting test reports in Launchable Github App.
+        : # https://github.com/launchableinc/cli/blob/v1.80.1/launchable/utils/link.py#L42
+        echo "GITHUB_PULL_REQUEST_URL=${INPUT_PR_HTML_URL}" >> $GITHUB_ENV
+        : # The following envs are necessary in Launchable tokenless authentication.
+        : # https://github.com/launchableinc/cli/blob/v1.80.1/launchable/utils/authentication.py#L20
+        echo "LAUNCHABLE_ORGANIZATION=${INPUT_REPOSITORY_OWNER}" >> $GITHUB_ENV
+        echo "LAUNCHABLE_WORKSPACE=${INPUT_REPOSITORY_NAME}" >> $GITHUB_ENV
+        : # https://github.com/launchableinc/cli/blob/v1.80.1/launchable/utils/authentication.py#L71
+        echo "GITHUB_PR_HEAD_SHA=${INPUT_PR_HEAD_SHA}" >> $GITHUB_ENV
+        echo "LAUNCHABLE_TOKEN=${INPUT_LAUNCHABLE_TOKEN}" >> $GITHUB_ENV
+        : # To prevent a slowdown in CI, disable request retries when the Launchable server is unstable.
+        echo "LAUNCHABLE_SKIP_TIMEOUT_RETRY=1" >> $GITHUB_ENV
+        echo "LAUNCHABLE_COMMIT_TIMEOUT=1" >> $GITHUB_ENV
+      env:
+        INPUT_PR_HTML_URL: ${{ github.event.pull_request.html_url }}
+        INPUT_REPOSITORY_OWNER: ${{ github.repository_owner }}
+        INPUT_REPOSITORY_NAME: ${{ github.event.repository.name }}
+        INPUT_PR_HEAD_SHA: ${{ github.event.pull_request.head.sha || github.sha }}
+        INPUT_LAUNCHABLE_TOKEN: ${{ inputs.launchable-token }}
+      if: steps.enable-launchable.outputs.enable-launchable
+
+    - name: Set up path
+      shell: bash
+      working-directory: ${{ inputs.srcdir }}
+      # Since updated PATH variable will be available in only subsequent actions, we need to add the path beforehand.
+      # https://docs.github.com/en/actions/using-workflows/workflow-commands-for-github-actions#adding-a-system-path
+      run: echo "$(python -msite --user-base)/bin" >> $GITHUB_PATH # zizmor: ignore[github-env]
+      if: >-
+        ${{
+        steps.enable-launchable.outputs.enable-launchable
+        && (startsWith(inputs.os, 'macos')
+          || endsWith(inputs.os, 'ppc64le')
+          || endsWith(inputs.os, 's390x'))
+        }}
+
+    - name: Set up Launchable
+      id: setup-launchable
+      shell: bash
+      working-directory: ${{ inputs.srcdir }}
+      run: | # zizmor: ignore[github-env]
+        set -x
+        pip install --user launchable
+        : # The build name cannot include a slash, so we replace the string here.
+        github_ref="${INPUT_GITHUB_REF}"
+        github_ref="${github_ref//\//_}"
+        : # With the --name option, we need to configure a unique identifier for this build.
+        : # To avoid setting the same build name as the CI which runs on other branches, we use the branch name here.
+        build_name="${github_ref}_${GITHUB_PR_HEAD_SHA}"
+        test_opts="${INPUT_TEST_OPTS}"
+        test_opts="${test_opts// /}"
+        test_opts="${test_opts//=/:}"
+        test_all_test_suite='test-all'
+        btest_test_suite='btest'
+        test_spec_test_suite='test-spec'
+        if [ "${INPUT_IS_YJIT}" = "true" ]; then
+          test_all_test_suite="yjit-${test_all_test_suite}"
+          btest_test_suite="yjit-${btest_test_suite}"
+          test_spec_test_suite="yjit-${test_spec_test_suite}"
+        fi
+        if [ "${INPUT_IS_ZJIT}" = "true" ]; then
+          test_all_test_suite="zjit-${test_all_test_suite}"
+          btest_test_suite="zjit-${btest_test_suite}"
+          test_spec_test_suite="zjit-${test_spec_test_suite}"
+        fi
+        # launchable_setup target var -- refers ${target} prefixed variables
+        launchable_setup() {
+          local target=$1 session
+          eval [ "\${${target}_enabled}" = "true" ] || return
+          eval local suite=\${${target}_test_suite}
+          session=$(launchable record session \
+            --build "${build_name}" \
+            --observation \
+            --flavor os="${INPUT_OS}" \
+            --flavor test_task="${INPUT_TEST_TASK}" \
+            --flavor test_opts="${test_opts}" \
+            --flavor workflow="${INPUT_WORKFLOW}" \
+            --test-suite ${suite} \
+            )
+          echo "${target}_session=${session}" >> $GITHUB_OUTPUT
+        }
+
+        launchable record build --name "${build_name}"
+        if launchable_setup test_all; then
+          echo "TESTS=${TESTS:+$TESTS }--launchable-test-reports=${test_all_report_file}" >> $GITHUB_ENV
+        fi
+        if launchable_setup btest; then
+          echo "BTESTS=${BTESTS:+$BTESTS }--launchable-test-reports=${btest_report_file}" >> $GITHUB_ENV
+        fi
+        if launchable_setup test_spec; then
+          echo "SPECOPTS=${SPECOPTS:$SPECOPTS }--launchable-test-reports=${test_spec_report_dir}" >> $GITHUB_ENV
+          echo test_spec_enabled=true >> $GITHUB_OUTPUT
+        fi
+
+        echo launchable_setup_dir=$(pwd) >> $GITHUB_OUTPUT
+      if: steps.enable-launchable.outputs.enable-launchable
+      env:
+        INPUT_GITHUB_REF: ${{ github.ref }}
+        INPUT_TEST_OPTS: ${{ inputs.test-opts }}
+        INPUT_IS_YJIT: ${{ inputs.is-yjit }}
+        INPUT_IS_ZJIT: ${{ inputs.is-zjit }}
+        INPUT_OS: ${{ inputs.os }}
+        INPUT_TEST_TASK: ${{ inputs.test-task }}
+        INPUT_WORKFLOW: ${{ github.workflow }}
+        test_all_enabled: ${{ steps.global.outputs.test_all_enabled }}
+        btest_enabled: ${{ steps.global.outputs.btest_enabled }}
+        test_spec_enabled: ${{ steps.global.outputs.test_spec_enabled }}
+        test_all_report_file: ${{ steps.global.outputs.test_all_report_file }}
+        btest_report_file: ${{ steps.global.outputs.btest_report_file }}
+        test_spec_report_dir: ${{ steps.global.outputs.test_spec_report_dir }}
+
+    - name: make test-spec report directory in build directory
+      shell: bash
+      working-directory: ${{ inputs.builddir }}
+      run: mkdir "${test_spec_report_dir}"
+      if: ${{ steps.setup-launchable.outputs.test_spec_enabled == 'true' }}
+      env:
+        test_spec_report_dir: ${{ steps.global.outputs.test_spec_report_dir }}
+
+    - name: Clean up test results in Launchable
+      uses: gacts/run-and-post-run@81b6ce503cde93862cec047c54652e45c5dca991 # v1.4.3
+      with:
+        shell: bash
+        working-directory: ${{ inputs.builddir }}
+        post: |
+          rm -f "${test_all_report_file}"
+          rm -f "${btest_report_file}"
+          rm -fr "${test_spec_report_dir}"
+          rm -f launchable_stdout.log
+          rm -f launchable_stderr.log
+      if: always() && steps.setup-launchable.outcome == 'success'
+      env:
+        test_all_report_file: ${{ steps.global.outputs.test_all_report_file }}
+        btest_report_file: ${{ steps.global.outputs.btest_report_file }}
+        test_spec_report_dir: ${{ steps.global.outputs.test_spec_report_dir }}
+
+    - name: Record test results in Launchable
+      uses: gacts/run-and-post-run@81b6ce503cde93862cec047c54652e45c5dca991 # v1.4.3
+      with:
+        shell: bash
+        working-directory: ${{ inputs.builddir }}
+        post: |
+          if [[ "${test_all_enabled}" = "true" ]]; then \
+            launchable record attachment \
+              --session "${test_all_session}" \
+              "${stdout_report_path}" \
+              "${stderr_report_path}"; \
+            launchable record tests \
+              --session "${test_all_session}" \
+              raw "${test_all_report_file}" || true; \
+          fi
+
+          if [[ "${btest_enabled}" = "true" ]]; then \
+            launchable record attachment \
+              --session "${btest_session}" \
+              "${stdout_report_path}" \
+              "${stderr_report_path}"; \
+            launchable record tests \
+              --session "${btest_session}" \
+              raw "${btest_report_file}" || true; \
+          fi
+
+          if [[ "${test_spec_enabled}" = "true" ]]; then \
+            launchable record attachment \
+              --session "${test_spec_session}" \
+              "${stdout_report_path}" \
+              "${stderr_report_path}"; \
+            launchable record tests \
+              --session "${test_spec_session}" \
+              raw ${test_spec_report_dir}/* || true; \
+          fi
+      if: ${{ always() && steps.setup-launchable.outcome == 'success' }}
+      env:
+        test_all_report_file: ${{ steps.global.outputs.test_all_report_file }}
+        btest_report_file: ${{ steps.global.outputs.btest_report_file }}
+        test_spec_report_dir: ${{ steps.global.outputs.test_spec_report_dir }}
+        test_all_enabled: ${{ steps.global.outputs.test_all_enabled }}
+        btest_enabled: ${{ steps.global.outputs.btest_enabled }}
+        test_spec_enabled: ${{ steps.global.outputs.test_spec_enabled }}
+        test_all_session: ${{ steps.setup-launchable.outputs.test_all_session }}
+        btest_session: ${{ steps.setup-launchable.outputs.btest_session }}
+        test_spec_session: ${{ steps.setup-launchable.outputs.test_spec_session }}
+        stdout_report_path: ${{ steps.global.outputs.stdout_report_path }}
+        stderr_report_path: ${{ steps.global.outputs.stderr_report_path }}
+        LAUNCHABLE_SETUP_DIR: ${{ steps.setup-launchable.outputs.launchable_setup_dir }}
diff --git a/.github/actions/make-snapshot/action.yml b/.github/actions/make-snapshot/action.yml
new file mode 100644
index 0000000000..4552f0e067
--- /dev/null
+++ b/.github/actions/make-snapshot/action.yml
@@ -0,0 +1,77 @@
+name: 'make-snapshot'
+description: 'Make snapshot tarballs'
+inputs:
+  archname:
+    description: 'archname passed to tool/make-snapshot (e.g. snapshot-master)'
+    required: true
+  version:
+    description: 'Target Version'
+    required: false
+  shallow-since:
+    description: 'git fetch --shallow-since'
+    required: true
+    default: '2018-12-25 00:00:00'
+  fetch-branch:
+    description: 'fetch branch'
+    required: false
+  srcdir:
+    description: 'srcdir for tool/make-snapshot. Empty = clone ruby/ruby into ./ruby.'
+    required: false
+    default: ''
+  upload-artifact:
+    description: 'Upload Packages and Info as workflow artifacts. Pass "false" when callers run in a matrix that would collide on artifact names.'
+    required: false
+    default: 'true'
+
+runs:
+  using: "composite"
+  steps:
+    - name: Install libraries
+      run: |
+        set -x
+        sudo apt-get update -q || :
+        sudo apt-get install --no-install-recommends -q -y build-essential git bison autoconf ruby p7zip-full curl
+      shell: bash
+    - name: Checkout ruby/ruby for tool/make-snapshot
+      if: inputs.srcdir == ''
+      run: git clone --single-branch --depth=1 https://github.com/ruby/ruby ruby
+      shell: bash
+    - name: Fetch branches and notes (clone mode)
+      if: inputs.srcdir == ''
+      env:
+        SHALLOW_SINCE: ${{ inputs.shallow-since }}
+        FETCH_BRANCH: ${{ inputs.fetch-branch }}
+      run: |
+        set -x
+        cd ruby
+        git fetch --shallow-since="$SHALLOW_SINCE"
+        [ -n "$FETCH_BRANCH" ] && git fetch origin "+$FETCH_BRANCH:$FETCH_BRANCH"
+        git fetch origin '+refs/notes/commits:refs/notes/commits'
+        git fetch origin '+refs/notes/log-fix:refs/notes/log-fix'
+      shell: bash
+    - name: Fetch notes (local srcdir mode)
+      if: inputs.srcdir != ''
+      working-directory: ${{ inputs.srcdir }}
+      run: |
+        git fetch origin '+refs/notes/commits:refs/notes/commits' || :
+        git fetch origin '+refs/notes/log-fix:refs/notes/log-fix' || :
+      shell: bash
+    - name: Make snapshot
+      env:
+        ARCHNAME: ${{ inputs.archname }}
+        SRCDIR: ${{ inputs.srcdir }}
+        VERSION: ${{ inputs.version }}
+      run: |
+        [ -z "$SRCDIR" ] && SRCDIR=ruby
+        ruby "$SRCDIR/tool/make-snapshot" "-archname=$ARCHNAME" -srcdir="$SRCDIR" -packages=gzip,xz,zip pkg $VERSION
+      shell: bash
+    - uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7.0.1
+      with:
+        name: Packages
+        path: pkg
+      if: ${{ inputs.upload-artifact == 'true' }}
+    - uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7.0.1
+      with:
+        name: Info
+        path: pkg/info
+      if: ${{ inputs.upload-artifact == 'true' }}
diff --git a/.github/actions/setup/baseruby/action.yml b/.github/actions/setup/baseruby/action.yml
new file mode 100644
index 0000000000..76fe068897
--- /dev/null
+++ b/.github/actions/setup/baseruby/action.yml
@@ -0,0 +1,73 @@
+name: Setup directories etc.
+description: >-
+  Build baseruby for cross-compiling
+
+inputs:
+  srcdir:
+    required: true
+    default: ${{ github.workspace }}
+    description: >-
+      Directory of source codes.
+
+  builddir:
+    required: false
+    default: ${{ github.workspace }}/baseruby
+    description: >-
+      Where baseruby will be built.
+
+  installdir:
+    required: false
+    default: install
+    description: >-
+      The path where the baseruby will be installed to.
+      This is relative from the workspace.
+
+outputs:
+  ruby:
+    value: ${{ steps.build.outputs.installdir }}/bin/ruby
+    description: >-
+      The path of the executable baseruby.
+  dump_ast:
+    value: ${{ steps.build.outputs.installdir }}/bin/dump_ast
+    description: >-
+      The path of the executable dump_ast.
+
+runs:
+  using: composite
+
+  steps:
+    - name: Build baseruby
+      shell: bash
+      id: build
+      run: |
+        case "$installdir" in /*) ;; *) installdir="$PWD/$installdir";; esac
+        mkdir "$builddir"
+        ln -sr "$srcdir" "$builddir/.src"
+        pushd "$builddir"
+        .src/configure "--prefix=${installdir}" --disable-install-doc
+        CONFIGURE_ARGS=--with-out-ext=-test- make install
+        install dump_ast "${installdir}/bin"
+        {
+          echo "${installdir}/bin/dump_ast"
+          echo "${installdir}/.installed.list"
+          echo "${installdir}/"
+        } >> .installed.list
+        cp .installed.list "${installdir}/"
+        make distclean
+        rm .src
+        popd
+        rmdir "$builddir"
+        {
+          echo "installdir=${installdir}"
+        } | tee -a "$GITHUB_OUTPUT"
+      env:
+        srcdir: ${{ inputs.srcdir }}
+        builddir: ${{ inputs.builddir }}
+        installdir: ${{ inputs.installdir }}
+
+    - name: clean
+      uses: gacts/run-and-post-run@598d7a875d5620e0457490555b5e18e46082aa47 # v1.4.4
+      with:
+        working-directory: ${{ inputs.srcdir }}
+        post: |
+          ruby tool/rbuninstall.rb "${{ steps.build.outputs.installdir }}/.installed.list" > /dev/null
diff --git a/.github/actions/setup/directories/action.yml b/.github/actions/setup/directories/action.yml
index 325af6608d..15dc097b6e 100644
--- a/.github/actions/setup/directories/action.yml
+++ b/.github/actions/setup/directories/action.yml
@@ -19,6 +19,13 @@ inputs:
       Where binaries and other generated contents go.  This will be
       created if absent.
 
+  make-command:
+    required: false
+    type: string
+    default: 'make'
+    description: >-
+      The command of `make`.
+
   makeup:
     required: false
     type: boolean
@@ -44,6 +51,18 @@ inputs:
     description: >-
       If set to true, creates dummy files in build dir.
 
+  fetch-depth:
+    required: false
+    default: '1'
+    description: The depth of commit history fetched from the remote repository
+
+  clean:
+    required: false
+    type: boolean
+    default: ''
+    description: >-
+      If set to true, clean build directory.
+
 outputs: {} # nothing?
 
 runs:
@@ -55,8 +74,11 @@ runs:
     # their bash manually installed.
     - shell: bash
       run: |
-        mkdir -p ${{ inputs.srcdir }}
-        mkdir -p ${{ inputs.builddir }}
+        mkdir -p "${INPUT_SRCDIR}"
+        mkdir -p "${INPUT_BUILDDIR}"
+      env:
+        INPUT_SRCDIR: ${{ inputs.srcdir }}
+        INPUT_BUILDDIR: ${{ inputs.builddir }}
 
     # Did you know that actions/checkout works without git(1)?  We are
     # checking that here.
@@ -64,7 +86,7 @@ runs:
       shell: bash
       run: |
         echo "git=`command -v git`" >> "$GITHUB_OUTPUT"
-        echo "sudo=`command -v sudo`" >> "$GITHUB_OUTPUT"
+        echo "sudo=`sudo true && command -v sudo`" >> "$GITHUB_OUTPUT"
         echo "autoreconf=`command -v autoreconf`" >> "$GITHUB_OUTPUT"
 
     - if: steps.which.outputs.git
@@ -76,62 +98,108 @@ runs:
         git config --global init.defaultBranch garbage
 
     - if: inputs.checkout
-      uses: actions/checkout@c85c95e3d7251135ab7dc9ce3241c5835cc595a9 # v3.5.3
+      uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
       with:
         path: ${{ inputs.srcdir }}
+        fetch-depth: ${{ inputs.fetch-depth }}
+        persist-credentials: false
 
-    - uses: actions/cache@88522ab9f39a2ea568f7027eddc7d8d8bc9d59c8 # v3.3.1
+    - uses: actions/cache@27d5ce7f107fe9357f9df03efb73ab90386fccae # v5.0.5
       with:
         path: ${{ inputs.srcdir }}/.downloaded-cache
-        key: downloaded-cache
+        key: ${{ runner.os }}-${{ runner.arch }}-downloaded-cache
 
     - if: steps.which.outputs.autoreconf
       shell: bash
       working-directory: ${{ inputs.srcdir }}
-      run: ./autogen.sh
+      run: ./autogen.sh --install
 
     # This is for MinGW.
     - if: runner.os == 'Windows'
       shell: bash
-      run: echo "GNUMAKEFLAGS=-j$((2 * NUMBER_OF_PROCESSORS))" >> $GITHUB_ENV
+      run: echo "GNUMAKEFLAGS=-j$((2 * NUMBER_OF_PROCESSORS))" >> $GITHUB_ENV # zizmor: ignore[github-env]
 
     - if: runner.os == 'Linux'
       shell: bash
-      run: echo "GNUMAKEFLAGS=-sj$((1 + $(nproc --all)))" >> "$GITHUB_ENV"
+      run: echo "GNUMAKEFLAGS=-sj$((1 + $(nproc)))" >> "$GITHUB_ENV" # zizmor: ignore[github-env]
 
     # macOS' GNU make is so old that they doesn't understand `GNUMAKEFLAGS`.
     - if: runner.os == 'macOS'
       shell: bash
-      run: echo "MAKEFLAGS=-j$((1 + $(sysctl -n hw.activecpu)))" >> "$GITHUB_ENV"
+      run: echo "MAKEFLAGS=-j$((1 + $(sysctl -n hw.activecpu)))" >> "$GITHUB_ENV" # zizmor: ignore[github-env]
 
     - if: inputs.makeup
       shell: bash
       working-directory: ${{ inputs.srcdir }}
       run: |
-        touch config.status
-        touch .rbconfig.time
-        sed -f tool/prereq.status template/Makefile.in > Makefile
-        sed -f tool/prereq.status template/GNUmakefile.in > GNUmakefile
+        touch config.status .rbconfig.time
+        for mk in Makefile GNUmakefile; do
+          sed -f tool/prereq.status template/$mk.in > $mk
+        done
         make up
 
     # Cleanup, runs even on failure
     - if: always() && inputs.makeup
       shell: bash
       working-directory: ${{ inputs.srcdir }}
-      run: rm -f config.status Makefile rbconfig.rb .rbconfig.time
+      run: |
+        rm -f config.status .rbconfig.time \
+          Makefile GNUmakefile uncommon.mk enc.mk noarch-fake.rb
+        rm -f prism/.time prism/util/.time
 
     - if: steps.which.outputs.sudo
       shell: bash
       run: |
         sudo chmod -R go-w /usr/share
         chmod -v go-w $HOME $HOME/.config || :
-        sudo bash -c 'IFS=:; for d in '"$PATH"'; do chmod -v go-w $d; done' || :
+        declare -a dirs # -A is not supported by old bash, e.g. macos
+        SAVE_IFS="$IFS" IFS=:; set $PATH
+        for d do
+          while [ -d "$d" ]; do
+            case "$IFS${dirs[*]}$IFS" in *"$IFS$d$IFS"*) ;; *) dirs+=("$d");; esac
+            d="${d%/*}"
+          done
+        done
+        IFS="$SAVE_IFS"
+        sudo chmod -v go-w "${dirs[@]}" || :
 
     - if: inputs.dummy-files == 'true'
       shell: bash
+      id: dummy-files
       working-directory: ${{ inputs.builddir }}
       run: |
         : Create dummy files in build dir
-        for basename in {a..z} {A..Z} {0..9} foo bar test zzz; do
-          echo > ${basename}.rb "raise %(do not load ${basename}.rb)"
+        set {{a..z},{A..Z},{0..9},foo,bar,test,zzz}.rb
+        for file; do \
+          echo > $file "raise 'do not load $file'"; \
         done
+        # drop {a..z}.rb if case-insensitive filesystem
+        grep -F A.rb a.rb > /dev/null && set "${@:27}"
+        echo clean="cd ${INPUT_BUILDDIR} && rm $*" >> $GITHUB_OUTPUT
+      env:
+        INPUT_BUILDDIR: ${{ inputs.builddir }}
+
+    - if: inputs.clean == 'true'
+      shell: bash
+      id: clean
+      run: |
+        echo distclean="cd ${INPUT_BUILDDIR} && ${INPUT_MAKE_COMMAND} distclean" >> $GITHUB_OUTPUT
+        echo remained-files="find ${INPUT_BUILDDIR} -ls" >> $GITHUB_OUTPUT
+        [ "${INPUT_BUILDDIR}" = "${INPUT_SRCDIR}" ] ||
+        echo final="rmdir ${INPUT_BUILDDIR}" >> $GITHUB_OUTPUT
+      env:
+        INPUT_BUILDDIR: ${{ inputs.builddir }}
+        INPUT_SRCDIR: ${{ inputs.srcdir }}
+        INPUT_MAKE_COMMAND: ${{ inputs.make-command }}
+
+    - name: clean
+      uses: gacts/run-and-post-run@598d7a875d5620e0457490555b5e18e46082aa47 # v1.4.4
+      with:
+        working-directory:
+        post: |
+          ${{ steps.dummy-files.outputs.clean }}
+          ${{ steps.clean.outputs.distclean }}
+          ${{ steps.clean.outputs.remained-files }}
+          ${{ steps.clean.outputs.final }}
+      # rmdir randomly fails due to launchable files
+      continue-on-error: true
diff --git a/.github/actions/setup/macos/action.yml b/.github/actions/setup/macos/action.yml
index 3649a64876..9cd37a9b12 100644
--- a/.github/actions/setup/macos/action.yml
+++ b/.github/actions/setup/macos/action.yml
@@ -13,12 +13,17 @@ runs:
     - name: brew
       shell: bash
       run: |
-        brew install --quiet gmp libffi openssl@1.1 zlib autoconf automake libtool readline
+        brew install --quiet jemalloc gmp libffi openssl@3 zlib autoconf automake libtool
 
     - name: Set ENV
       shell: bash
-      run: |
-        for lib in openssl@1.1 readline; do
-          CONFIGURE_ARGS="${CONFIGURE_ARGS:+$CONFIGURE_ARGS }--with-${lib%@*}-dir=$(brew --prefix $lib)"
-        done
-        echo CONFIGURE_ARGS="${CONFIGURE_ARGS}" >> $GITHUB_ENV
+      run: | # zizmor: ignore[github-env]
+        dir_config() {
+          local args=() lib var="$1"; shift
+          for lib in "$@"; do
+            args+=("--with-${lib%@*}-dir=$(brew --prefix $lib)")
+          done
+          echo "$var=${args[*]}" >> $GITHUB_ENV
+        }
+        dir_config ruby_configure_args gmp
+        dir_config CONFIGURE_ARGS openssl@3
diff --git a/.github/actions/setup/ubuntu/action.yml b/.github/actions/setup/ubuntu/action.yml
index a9e5b41951..5209ccc03f 100644
--- a/.github/actions/setup/ubuntu/action.yml
+++ b/.github/actions/setup/ubuntu/action.yml
@@ -24,18 +24,38 @@ runs:
   using: composite
 
   steps:
+    - id: uname
+      name: uname
+      shell: bash
+      env:
+        arch: ${{ inputs.arch }}
+      run: |
+        setarch="${arch:+setarch $arch --}"
+        # normalize `uname`
+        if uname=$(${setarch} uname -m 2> /dev/null); then
+          # `setarch` works, `$arch` is a valid architecture name.
+          echo "setarch=${setarch}" >> "$GITHUB_OUTPUT"
+        else
+          # if `setarch` failed, take the given `arch` as-is.
+          uname="${arch}"
+          setarch=""
+        fi
+        echo "uname=$uname" >> "$GITHUB_OUTPUT"
+        echo "dpkg=${uname/686/386}" >> "$GITHUB_OUTPUT"
+
     - name: set SETARCH
       shell: bash
-      run: echo "SETARCH=${setarch}" >> "$GITHUB_ENV"
+      run: echo "SETARCH=${setarch}" >> "$GITHUB_ENV" # zizmor: ignore[github-env]
       env:
-        setarch: ${{ inputs.arch && format('setarch {0} --', inputs.arch) }}
+        setarch: ${{ steps.uname.outputs.setarch }} # validated
 
-    - id: uname
-      name: uname
+    - name: dpkg setup
       shell: bash
-      run: |
-        echo uname=`${SETARCH} uname -m` >> "$GITHUB_OUTPUT"
-        echo dpkg=`${SETARCH} uname -m | sed s/686/386/` >> "$GITHUB_OUTPUT"
+      run: sudo dpkg --add-architecture "${dpkg}"
+      # `dpkg` is valid, also `uname`.
+      if: ${{ inputs.arch }}
+      env:
+        dpkg: ${{ steps.uname.outputs.dpkg }}
 
     - name: apt-get
       shell: bash
@@ -43,7 +63,6 @@ runs:
         arch: ${{ inputs.arch && format(':{0}', steps.uname.outputs.dpkg) || '' }}
       run: |
         set -x
-        ${arch:+sudo dpkg --add-architecture ${arch#:}}
         sudo apt-get update -qq || :
         sudo apt-get install --no-install-recommends -qq -y -o=Dpkg::Use-Pty=0 \
         ${arch:+cross}build-essential${arch/:/-} \
diff --git a/.github/actions/slack/action.yml b/.github/actions/slack/action.yml
index c98be085a8..6f89bef11a 100644
--- a/.github/actions/slack/action.yml
+++ b/.github/actions/slack/action.yml
@@ -9,7 +9,7 @@ inputs:
     required: true
     description: >-
       The URL to post the payload.  This is an input because it tends
-      to be stored in a secrets valut and a composite action cannot
+      to be stored in a secrets vault and a composite action cannot
       look into one.
 
   label:
@@ -18,13 +18,24 @@ inputs:
       Human-readable description of the run, something like "DEBUG=1".
       This need not be unique among runs.
 
+  event_name:
+    required: false
+    default: 'push'
+    description: >-
+      Target event to trigger notification. Notify only push by default.
+
+  extra_channel_id:
+    required: false
+    description: >-
+      Slack channel ID to notify besides #alerts and #alerts-emoji.
+
 outputs: {} # Nothing?
 
 runs:
   using: composite
 
   steps:
-    - uses: ruby/action-slack@0bd85c72233cdbb6a0fe01d37aaeff1d21b5fce1 # v3.2.1
+    - uses: ruby/action-slack@d260b61aa817726d5bedd22dd6cc305787fa4cdd # v4.0.0
       with:
         payload: |
           {
@@ -33,7 +44,8 @@ runs:
             "url": "https://github.com/${{ github.repository }}/actions/runs/${{ github.run_id }}",
             "commit": "${{ github.sha }}",
             "branch": "${{ github.ref_name }}"
+            ${{ inputs.extra_channel_id && format(', "extra_channel_id": "{0}"', inputs.extra_channel_id) }}
           }
       env:
         SLACK_WEBHOOK_URL: ${{ inputs.SLACK_WEBHOOK_URL }}
-      if: ${{github.event_name == 'push' && startsWith(github.repository, 'ruby/')}}
+      if: ${{ github.event_name == inputs.event_name && startsWith(github.repository, 'ruby/') }}
diff --git a/.github/auto_request_review.yml b/.github/auto_request_review.yml
index 8726df577d..9e20cb7459 100644
--- a/.github/auto_request_review.yml
+++ b/.github/auto_request_review.yml
@@ -1,13 +1,21 @@
 files:
-  'yjit*': [team:yjit]
-  'yjit/**/*': [team:yjit]
+  'yjit*': [team:jit]
+  'yjit/**/*': [team:jit]
   'yjit/src/cruby_bindings.inc.rs': []
-  'doc/yjit/*': [team:yjit]
-  'bootstraptest/test_yjit*': [team:yjit]
-  'test/ruby/test_yjit*': [team:yjit]
+  'bootstraptest/test_yjit*': [team:jit]
+  'test/ruby/test_yjit*': [team:jit]
+  'zjit*': [team:jit]
+  'zjit/**/*': [team:jit]
+  'zjit/src/cruby_bindings.inc.rs': []
+  'test/ruby/test_zjit*': [team:jit]
+  'defs/jit.mk': [team:jit]
+  'tool/zjit_bisect.rb': [team:jit]
+  'doc/jit/*': [team:jit]
+  # Skip files updated by dependabot. It's noisy in notifications, and they're auto-merged anyway.
+  'yjit/Cargo.lock': []
+  'zjit/Cargo.lock': []
+  '.github/workflows/yjit-*.yml': []
+  '.github/workflows/zjit-*.yml': []
 options:
   ignore_draft: true
-  # This currently doesn't work as intended. We want to skip reviews when only
-  # cruby_bingings.inc.rs is modified, but this skips reviews even when other
-  # yjit files are modified as well. To be enabled after fixing the behavior.
-  #last_files_match_only: true
+  last_files_match_only: true
diff --git a/.github/codeql/codeql-config.yml b/.github/codeql/codeql-config.yml
new file mode 100644
index 0000000000..f5d33545c1
--- /dev/null
+++ b/.github/codeql/codeql-config.yml
@@ -0,0 +1,22 @@
+paths-ignore:
+  - benchmark
+  - sample
+  - spec/ruby/command_line/fixtures
+  - spec/ruby/core/enumerable/shared/inject.rb
+  - spec/ruby/core/exception/fixtures
+  - spec/ruby/core/proc/parameters_spec.rb
+  - spec/ruby/core/proc/ruby2_keywords_spec.rb
+  - spec/ruby/core/range/reverse_each_spec.rb
+  - spec/ruby/language/fixtures
+  - spec/ruby/language/lambda_spec.rb
+  - spec/ruby/language/method_spec.rb
+  - spec/ruby/language/string_spec.rb
+  - test/error_highlight/test_error_highlight.rb
+  - test/prism/result/named_capture_test.rb
+  - test/ruby/test_call.rb
+  - test/ruby/test_signal.rb
+  - test/ruby/test_super.rb
+  - test/ruby/test_syntax.rb
+  - test/ruby/test_unicode_escape.rb
+  - test/rubygems/specifications/foo-0.0.1-x86-mswin32.gemspec
+  - trace_point.rb
diff --git a/.github/dependabot.yml b/.github/dependabot.yml
index 6778b0493a..57da742e5c 100644
--- a/.github/dependabot.yml
+++ b/.github/dependabot.yml
@@ -1,6 +1,29 @@
 version: 2
 updates:
   - package-ecosystem: 'github-actions'
+    directories:
+      - '/'
+      - '/.github/actions/slack'
+      - '/.github/actions/setup/directories'
+    schedule:
+      interval: 'daily'
+    groups:
+      github-actions:
+        patterns:
+          - "*"
+  - package-ecosystem: 'cargo'
+    directories:
+      - '/yjit'
+      - '/zjit'
+    exclude-paths:
+      - 'gc/mmtk/**'
+    schedule:
+      interval: 'monthly'
+    groups:
+      jit:
+        patterns:
+          - "*"
+  - package-ecosystem: 'vcpkg'
     directory: '/'
     schedule:
       interval: 'daily'
diff --git a/.github/labeler.yml b/.github/labeler.yml
new file mode 100644
index 0000000000..f39fcec386
--- /dev/null
+++ b/.github/labeler.yml
@@ -0,0 +1,7 @@
+Documentation:
+- changed-files:
+  - all-globs-to-all-files: doc/**
+
+Backport:
+- base-branch: 'ruby_3_\d'
+- base-branch: 'ruby_4_\d'
diff --git a/.github/workflows/annocheck.yml b/.github/workflows/annocheck.yml
index 582285afa8..5991165d43 100644
--- a/.github/workflows/annocheck.yml
+++ b/.github/workflows/annocheck.yml
@@ -4,24 +4,20 @@ on:
   push:
     paths-ignore:
       - 'doc/**'
-      - '**/man'
+      - '**/man/*'
       - '**.md'
       - '**.rdoc'
       - '**/.document'
+      - '.*.yml'
   pull_request:
     paths-ignore:
       - 'doc/**'
-      - '**/man'
+      - '**/man/*'
       - '**.md'
       - '**.rdoc'
       - '**/.document'
+      - '.*.yml'
   merge_group:
-    paths-ignore:
-      - 'doc/**'
-      - '**/man'
-      - '**.md'
-      - '**.rdoc'
-      - '**/.document'
 
 concurrency:
   group: ${{ github.workflow }} / ${{ startsWith(github.event_name, 'pull') && github.ref_name || github.sha }}
@@ -32,7 +28,7 @@ permissions:
 
 jobs:
   compile:
-    name: gcc-11 annocheck
+    name: test-annocheck
 
     runs-on: ubuntu-latest
 
@@ -45,7 +41,7 @@ jobs:
       || contains(github.event.head_commit.message, '[DOC]')
       || contains(github.event.pull_request.title, '[DOC]')
       || contains(github.event.pull_request.labels.*.name, 'Documentation')
-      || (github.event_name == 'push' && github.actor == 'dependabot[bot]')
+      || (github.event.pull_request.user.login == 'dependabot[bot]')
       )}}
 
     env:
@@ -65,10 +61,11 @@ jobs:
       - run: id
         working-directory:
 
-      - uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4.1.1
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
         with:
           sparse-checkout-cone-mode: false
           sparse-checkout: /.github
+          persist-credentials: false
 
       - uses: ./.github/actions/setup/directories
         with:
@@ -76,6 +73,11 @@ jobs:
           builddir: build
           makeup: true
 
+      - uses: ruby/setup-ruby@afeafc3d1ab54a631816aba4c914a0081c12ff2f # v1.310.0
+        with:
+          ruby-version: '3.1'
+          bundler: none
+
       # Minimal flags to pass the check.
       # -g0 disables backtraces when SEGV.  Do not set that.
       - name: Run configure
@@ -97,20 +99,6 @@ jobs:
 
       - run: make
 
-      - run: make test
-
-      - run: make install
-
-      - run: make test-tool
-
-      ### test-all doesn't work: https://github.com/ruby/ruby/actions/runs/4340112185/jobs/7578344307
-      # - run: make test-all TESTS='-- ruby -ext-'
-
-      ### test-spec doesn't work: https://github.com/ruby/ruby/actions/runs/4340193212/jobs/7578505652
-      # - run: make test-spec
-      #   env:
-      #     CHECK_LEAKS: true
-
       - run: make test-annocheck
 
       - uses: ./.github/actions/slack
diff --git a/.github/workflows/auto_request_review.yml b/.github/workflows/auto_request_review.yml
index d9eb774e3f..80f2517eb5 100644
--- a/.github/workflows/auto_request_review.yml
+++ b/.github/workflows/auto_request_review.yml
@@ -2,6 +2,7 @@ name: Auto Request Review
 on:
   pull_request_target:
     types: [opened, ready_for_review, reopened]
+    branches: [master]
 
 permissions:
   contents: read
@@ -10,10 +11,10 @@ jobs:
   auto-request-review:
     name: Auto Request Review
     runs-on: ubuntu-latest
-    if: ${{ github.repository == 'ruby/ruby' }}
+    if: ${{ github.repository == 'ruby/ruby' && github.base_ref == 'master' }}
     steps:
       - name: Request review based on files changes and/or groups the author belongs to
-        uses: necojackarc/auto-request-review@6a51cebffe2c084705d9a7b394abd802e0119633 # v0.12.0
+        uses: necojackarc/auto-request-review@035f049cb68460341ab744f19aa9f31aae685e36 # master
         with:
           # scope: public_repo
-          token: ${{ secrets.MATZBOT_GITHUB_TOKEN }}
+          token: ${{ secrets.MATZBOT_AUTO_REQUEST_REVIEW_TOKEN }}
diff --git a/.github/workflows/auto_review_pr.yml b/.github/workflows/auto_review_pr.yml
new file mode 100644
index 0000000000..bb84a51573
--- /dev/null
+++ b/.github/workflows/auto_review_pr.yml
@@ -0,0 +1,41 @@
+name: Auto Review PR
+on:
+  pull_request_target:
+    types: [opened, ready_for_review, reopened]
+    branches: [master]
+  workflow_dispatch:
+    inputs:
+      pr_number:
+        description: 'PR number to review'
+        required: true
+        type: number
+
+permissions:
+  contents: read
+
+jobs:
+  auto-review-pr:
+    name: Auto Review PR
+    runs-on: ubuntu-latest
+    if: ${{ github.repository == 'ruby/ruby' && (github.base_ref == 'master' || github.event_name == 'workflow_dispatch') }}
+
+    permissions:
+      pull-requests: write
+      contents: read
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with:
+          persist-credentials: false
+
+      - uses: ruby/setup-ruby@afeafc3d1ab54a631816aba4c914a0081c12ff2f # v1.310.0
+        with:
+          ruby-version: '3.4'
+          bundler: none
+
+      - name: Auto Review PR
+        run: ruby tool/auto_review_pr.rb "$GITHUB_PR_NUMBER"
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          GITHUB_PR_NUMBER: ${{ github.event.pull_request.number || github.event.inputs.pr_number }}
diff --git a/.github/workflows/baseruby.yml b/.github/workflows/baseruby.yml
index 8e79ac67c9..9e7720f659 100644
--- a/.github/workflows/baseruby.yml
+++ b/.github/workflows/baseruby.yml
@@ -4,24 +4,20 @@ on:
   push:
     paths-ignore:
       - 'doc/**'
-      - '**/man'
+      - '**/man/*'
       - '**.md'
       - '**.rdoc'
       - '**/.document'
+      - '.*.yml'
   pull_request:
     paths-ignore:
       - 'doc/**'
-      - '**/man'
+      - '**/man/*'
       - '**.md'
       - '**.rdoc'
       - '**/.document'
+      - '.*.yml'
   merge_group:
-    paths-ignore:
-      - 'doc/**'
-      - '**/man'
-      - '**.md'
-      - '**.rdoc'
-      - '**/.document'
 
 concurrency:
   group: ${{ github.workflow }} / ${{ startsWith(github.event_name, 'pull') && github.ref_name || github.sha }}
@@ -34,33 +30,32 @@ jobs:
   baseruby:
     name: BASERUBY
 
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-22.04
 
     if: >-
       ${{!(false
       || contains(github.event.head_commit.message, '[DOC]')
       || contains(github.event.pull_request.title, '[DOC]')
       || contains(github.event.pull_request.labels.*.name, 'Documentation')
-      || (github.event_name == 'push' && github.actor == 'dependabot[bot]')
+      || (github.event.pull_request.user.login == 'dependabot[bot]')
       )}}
 
     strategy:
       matrix:
         ruby:
-          - ruby-2.5
-#         - ruby-2.6
-#         - ruby-2.7
-          - ruby-3.0
           - ruby-3.1
           - ruby-3.2
+          - ruby-3.3
 
     steps:
-      - uses: ruby/setup-ruby@a05e47355e80e57b9a67566a813648fa67d92011 # v1.157.0
+      - uses: ruby/setup-ruby@afeafc3d1ab54a631816aba4c914a0081c12ff2f # v1.310.0
         with:
           ruby-version: ${{ matrix.ruby }}
           bundler: none
 
-      - uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4.1.1
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with:
+          persist-credentials: false
 
       - uses: ./.github/actions/setup/ubuntu
 
diff --git a/.github/workflows/bundled_gems.yml b/.github/workflows/bundled_gems.yml
index 1827420154..d329ee9b4b 100644
--- a/.github/workflows/bundled_gems.yml
+++ b/.github/workflows/bundled_gems.yml
@@ -1,5 +1,8 @@
 name: bundled_gems
 
+env:
+  UPDATE_ENABLED: true
+
 on:
   push:
     branches: ['master']
@@ -12,10 +15,6 @@ on:
       - '.github/workflows/bundled_gems.yml'
       - 'gems/bundled_gems'
   merge_group:
-    branches: ['master']
-    paths:
-      - '.github/workflows/bundled_gems.yml'
-      - 'gems/bundled_gems'
   schedule:
     - cron: '45 6 * * *'
   workflow_dispatch:
@@ -35,9 +34,18 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-      - uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4.1.1
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with:
+          token: ${{ (github.repository == 'ruby/ruby' && !startsWith(github.event_name, 'pull')) && secrets.MATZBOT_AUTO_UPDATE_TOKEN || secrets.GITHUB_TOKEN }}
+
+      - uses: ruby/setup-ruby@afeafc3d1ab54a631816aba4c914a0081c12ff2f # v1.310.0
+        with:
+          ruby-version: 4.0
 
       - uses: ./.github/actions/setup/directories
+        with:
+          # Skip overwriting MATZBOT_AUTO_UPDATE_TOKEN
+          checkout: '' # false (ref: https://github.com/actions/runner/issues/2238)
 
       - name: Set ENV
         run: |
@@ -45,19 +53,23 @@ jobs:
 
       - name: Download previous gems list
         run: |
-          data=bundled_gems.json
           mkdir -p .downloaded-cache
-          ln -s .downloaded-cache/$data .
-          curl -O -R -z ./$data https://stdgems.org/$data
+          for data in bundled_gems.json default_gems.json; do
+            ln -s .downloaded-cache/$data .
+            curl --retry 5 --retry-connrefused --retry-delay 2 --retry-max-time 60 -O -R -z ./$data https://stdgems.org/$data
+          done
 
       - name: Update bundled gems list
         id: bundled_gems
         run: |
-          ruby -i~ tool/update-bundled_gems.rb gems/bundled_gems > $GITHUB_OUTPUT
+          ruby -i~ tool/update-bundled_gems.rb gems/bundled_gems >> $GITHUB_OUTPUT
+        if: ${{ env.UPDATE_ENABLED == 'true' }}
 
       - name: Maintain updated gems list in NEWS
         run: |
           ruby tool/update-NEWS-gemlist.rb bundled
+          ruby tool/update-NEWS-github-release.rb --update
+        if: ${{ env.UPDATE_ENABLED == 'true' }}
 
       - name: Check diffs
         id: diff
@@ -72,6 +84,67 @@ jobs:
           echo gems=$gems >> $GITHUB_OUTPUT
           echo update=${news:-$gems} >> $GITHUB_OUTPUT
 
+      - name: Commit
+        id: commit
+        run: |
+          git pull --ff-only origin ${GITHUB_REF#refs/heads/}
+          message="Update bundled gems list"
+          if [ -z "${gems}" ]; then
+            git commit --message="[DOC] ${message} at ${GITHUB_SHA:0:30}"
+          else
+            git commit --message="${message} as of ${TODAY}"
+          fi
+        env:
+          TODAY: ${{ steps.bundled_gems.outputs.latest_date || env.TODAY }}
+          EMAIL: svn-admin@ruby-lang.org
+          GIT_AUTHOR_NAME: git
+          GIT_COMMITTER_NAME: git
+          gems: ${{ steps.diff.outputs.gems }}
+        if: ${{ steps.diff.outputs.update }}
+
+      - name: Development revision of bundled gems
+        run: |
+          #!ruby
+          file = "gems/bundled_gems"
+
+          SECONDS_IN_DAY = 86400
+          today = Time.new("#{ENV['TODAY']}Z")
+          if !(december = today.month == 12)
+            days = 30
+          elsif (days = 26 - today.day).positive?
+            days += 4
+          else
+            puts "::info:: just after released"
+            exit
+          end
+
+          since = "#{today.year-1}-12-26"
+          ref = ENV['GITHUB_REF']
+          puts "::group::\e[94mfetching \e[1m#{file}\e[22m since \e[1m#{since}\e[22m from \e[1m#{ref}\e[m"
+          system(*%W[git fetch --shallow-since=#{since} --no-tags origin #{ref}], exception: true)
+          puts "::endgroup::"
+
+          puts "\e[94mchecking development version bundled gems older than \e[1m#{days}\e[22m days\e[m"
+          limit = today.to_i - days * SECONDS_IN_DAY
+          old = 0
+          IO.popen(%W"git blame --line-porcelain -- #{file}") do |blame|
+            while head = blame.gets("\n\t") and s = blame.gets
+              next unless (gem = s.split(/\s+|#.*/)).size > 3
+              time = head[/^committer-time \K\d+/].to_i
+              next if (d = limit - time) <= 0
+              d /= SECONDS_IN_DAY
+              line = head[/\A\h+ \d+ \K\d+/].to_i
+              level = if d < days; 'warning'; else old += 1; 'error'; end
+              d += days
+              puts "::#{level} file=#{file},line=#{line},title=Older than #{d} days::#{gem[0]} #{gem[3]}"
+            end
+          end
+          abort "::error title=Too long-standing gems::The release comes soon." if december and old.nonzero?
+        shell: ruby {0}
+        env:
+          file: ${{ steps.logs.outputs.file }}
+          days: ${{ steps.logs.outputs.days }}
+
       - name: Install libraries
         uses: ./.github/actions/setup/ubuntu
         if: ${{ steps.diff.outputs.gems }}
@@ -97,27 +170,14 @@ jobs:
           TEST_BUNDLED_GEMS_ALLOW_FAILURES: ''
         if: ${{ steps.diff.outputs.gems }}
 
-      - name: Commit
+      - name: Push
         run: |
-          git pull --ff-only origin ${GITHUB_REF#refs/heads/}
-          message="Update bundled gems list"
-          if [ -z "${gem}" ]; then
-            git commit --message="${message} at ${GITHUB_SHA:0:30} [ci skip]"
-          else
-            git commit --message="${message} as of ${TODAY}"
-          fi
           git push origin ${GITHUB_REF#refs/heads/}
-        env:
-          TODAY: ${{ steps.bundled_gems.outputs.latest_date || env.TODAY }}
-          EMAIL: svn-admin@ruby-lang.org
-          GIT_AUTHOR_NAME: git
-          GIT_COMMITTER_NAME: git
-          gems: ${{ steps.diff.outputs.gems }}
         if: >-
           ${{
           github.repository == 'ruby/ruby' &&
           !startsWith(github.event_name, 'pull') &&
-          steps.diff.outputs.update
+          steps.commit.outcome == 'success'
           }}
 
       - uses: ./.github/actions/slack
diff --git a/.github/workflows/check_dependencies.yml b/.github/workflows/check_dependencies.yml
index 4da0b3696c..a120dde7e5 100644
--- a/.github/workflows/check_dependencies.yml
+++ b/.github/workflows/check_dependencies.yml
@@ -3,24 +3,13 @@ on:
   push:
     paths-ignore:
       - 'doc/**'
-      - '**/man'
+      - '**/man/*'
       - '**.md'
       - '**.rdoc'
       - '**/.document'
+      - '.*.yml'
   pull_request:
-    paths-ignore:
-      - 'doc/**'
-      - '**/man'
-      - '**.md'
-      - '**.rdoc'
-      - '**/.document'
   merge_group:
-    paths-ignore:
-      - 'doc/**'
-      - '**/man'
-      - '**.md'
-      - '**.rdoc'
-      - '**/.document'
 
 concurrency:
   group: ${{ github.workflow }} / ${{ startsWith(github.event_name, 'pull') && github.ref_name || github.sha }}
@@ -31,23 +20,19 @@ permissions:
 
 jobs:
   update-deps:
+    name: Dependency checks
+
     strategy:
       matrix:
-        os: [ubuntu-20.04]
+        os: [ubuntu-latest]
       fail-fast: true
 
     runs-on: ${{ matrix.os }}
 
-    if: >-
-      ${{!(false
-      || contains(github.event.head_commit.message, '[DOC]')
-      || contains(github.event.pull_request.title, '[DOC]')
-      || contains(github.event.pull_request.labels.*.name, 'Documentation')
-      || (github.event_name == 'push' && github.actor == 'dependabot[bot]')
-      )}}
-
     steps:
-      - uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4.1.1
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with:
+          persist-credentials: false
 
       - uses: ./.github/actions/setup/ubuntu
         if: ${{ contains(matrix.os, 'ubuntu') }}
@@ -57,14 +42,17 @@ jobs:
 
       - uses: ./.github/actions/setup/directories
 
+      - uses: ruby/setup-ruby@afeafc3d1ab54a631816aba4c914a0081c12ff2f # v1.310.0
+        with:
+          ruby-version: '3.1'
+          bundler: none
+
       - name: Run configure
         run: ./configure -C --disable-install-doc --disable-rubygems --with-gcc 'optflags=-O0' 'debugflags=-save-temps=obj -g'
 
-      - run: make all golf
-
-      - run: ruby tool/update-deps --fix
+      - run: make fix-depends
 
-      - run: git diff --no-ext-diff --ignore-submodules --exit-code
+      - run: git diff --color --no-ext-diff --ignore-submodules --exit-code
 
       - uses: ./.github/actions/slack
         with:
diff --git a/.github/workflows/check_misc.yml b/.github/workflows/check_misc.yml
index 32ba8d71a6..cb1642b9e2 100644
--- a/.github/workflows/check_misc.yml
+++ b/.github/workflows/check_misc.yml
@@ -1,4 +1,4 @@
-name: Miscellaneous checks
+name: Misc
 on: [push, pull_request, merge_group]
 
 concurrency:
@@ -10,30 +10,57 @@ permissions:
 
 jobs:
   checks:
+    name: Miscellaneous checks
+
     permissions:
       contents: write # for Git to git push
 
     runs-on: ubuntu-latest
 
     steps:
-      - uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4.1.1
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with:
+          token: ${{ (github.repository == 'ruby/ruby' && !startsWith(github.event_name, 'pull')) && secrets.MATZBOT_AUTO_UPDATE_TOKEN || secrets.GITHUB_TOKEN }}
+          persist-credentials: false
+
+      - uses: ruby/setup-ruby@afeafc3d1ab54a631816aba4c914a0081c12ff2f # v1.310.0
         with:
-          token: ${{ (github.repository == 'ruby/ruby' && !startsWith(github.event_name, 'pull')) && secrets.MATZBOT_GITHUB_TOKEN || secrets.GITHUB_TOKEN }}
+          ruby-version: head
 
       - uses: ./.github/actions/setup/directories
         with:
           makeup: true
-          # Skip overwriting MATZBOT_GITHUB_TOKEN
+          # Skip overwriting MATZBOT_AUTO_UPDATE_TOKEN
           checkout: '' # false (ref: https://github.com/actions/runner/issues/2238)
 
-      - name: Check if C-sources are US-ASCII
+      - name: Re-generate Makefiles
+        run: |
+          # config.status needs to run as a shell script
+          { echo ':&&exit'; cat tool/prereq.status; } > config.status
+          : # same as actions/setup/directories/action.yml
+          for mk in Makefile GNUmakefile; do
+            sed -f tool/prereq.status template/$mk.in > $mk
+          done
+
+      - name: Check for code styles
         run: |
-          grep -r -n $'[^\t -~]' -- *.[chy] include internal win32/*.[ch] && exit 1 || :
+          set -x
+          ruby tool/auto-style.rb "$GITHUB_OLD_SHA" "$GITHUB_NEW_SHA"
+        env:
+          GITHUB_OLD_SHA: ${{ github.event.pull_request.base.sha }}
+          GITHUB_NEW_SHA: ${{ github.event.pull_request.merge_commit_sha }}
+        # Skip 'push' events because post_push.yml fixes them on push
+        if: ${{ github.repository == 'ruby/ruby' && startsWith(github.event_name, 'pull') }}
 
-      - name: Check for trailing spaces
+      - name: Check if date in man pages is up-to-date
         run: |
-          git grep -I -n $'[\t ]$' -- '*.rb' '*.[chy]' '*.rs' '*.yml' && exit 1 || :
-          git grep -n $'^[\t ][\t ]*$' -- '*.md' && exit 1 || :
+          git fetch origin --depth=1 "${GITHUB_OLD_SHA}"
+          git diff --exit-code --name-only "${GITHUB_OLD_SHA}" HEAD -- man ||
+          make V=1 GIT=git BASERUBY=ruby update-man-date
+          git diff --color --no-ext-diff --ignore-submodules --exit-code -- man
+        env:
+          GITHUB_OLD_SHA: ${{ github.event.pull_request.base.sha }}
+        if: ${{ startsWith(github.event_name, 'pull') }}
 
       - name: Check for bash specific substitution in configure.ac
         run: |
@@ -50,65 +77,74 @@ jobs:
           exit $fail
         working-directory: include
 
-      - id: gems
-        run: true
-        if: ${{ github.ref == 'refs/heads/master' }}
-
-      - name: Download previous gems list
+      - id: now
         run: |
-          data=default_gems.json
-          mkdir -p .downloaded-cache
-          ln -s .downloaded-cache/$data .
-          curl -O -R -z ./$data https://stdgems.org/$data
-        if: ${{ steps.gems.outcome == 'success' }}
+          date +"mon=%-m"%n"day=%-d" >> $GITHUB_OUTPUT
+        env:
+          TZ: Asia/Tokyo
 
-      - name: Make default gems list
+      - id: deprecation
         run: |
-          #!ruby
-          require 'rubygems'
-          $:.unshift "lib"
-          rgver = File.foreach("lib/rubygems.rb") do |line|
-            break $1 if /^\s*VERSION\s*=\s*"([^"]+)"/ =~ line
-          end
-          gems = Dir.glob("{ext,lib}/**/*.gemspec").map do |f|
-            spec = Gem::Specification.load(f)
-            "#{spec.name} #{spec.version}"
-          end.sort
-          File.open("gems/default_gems", "w") do |f|
-            f.puts "RubyGems #{rgver}"
-            f.puts gems
-          end
-        shell: ruby --disable=gems {0}
-        if: ${{ steps.gems.outcome == 'success' }}
-
-      - name: Maintain updated gems list in NEWS
+          eval $(sed -n 's/^#define RUBY_API_VERSION_\(MAJOR\|MINOR\) /\1=/p' include/ruby/version.h)
+          if git --no-pager grep --color -o 'rb_warn_deprecated_to_remove_at('$MAJOR'\.'$MINOR',.*' -- '*.c' >&2; then
+              false
+          else
+              true
+          fi
+        continue-on-error: ${{ steps.now.outputs.mon < 12 }}
+
+      - name: Check if to generate documents
+        id: rdoc
         run: |
-          ruby tool/update-NEWS-gemlist.rb default
-        if: ${{ steps.gems.outcome == 'success' }}
+          set -- $(sed 's/#.*//;/^rdoc /!d' gems/bundled_gems)
+          { echo version=$2; echo ref=$4; } >> $GITHUB_OUTPUT
+
+      - name: Checkout rdoc
+        uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with:
+          repository: ruby/rdoc
+          ref: ${{ steps.rdoc.outputs.ref }}
+          path: .bundle/gems/rdoc-${{ steps.rdoc.outputs.version }}
+          persist-credentials: false
+        if: ${{ steps.rdoc.outputs.ref != '' }}
 
-      - name: Check diffs
-        id: diff
+      - name: Generate rdoc scripts
         run: |
-          git diff --color --no-ext-diff --ignore-submodules --exit-code NEWS.md ||
-          echo update=true >> $GITHUB_OUTPUT
-        if: ${{ steps.gems.outcome == 'success' }}
+          set -x
+          gempath=$(ruby -e 'print Gem.user_dir, "/bin"')
+          PATH=$gempath:$PATH
+          gem install --user bundler
+          bundle config --local path vendor/bundle
+          bundle install --jobs 4
+          bundle exec rake generate
+        working-directory: .bundle/gems/rdoc-${{ steps.rdoc.outputs.version }}
+        if: ${{ steps.rdoc.outputs.ref != '' }}
+
+      - name: Core docs coverage
+        run: |
+          make XRUBY=ruby RDOC_DEPENDS= RBCONFIG=update-rbconfig rdoc-coverage
 
-      - name: Commit
+      - name: Generate docs
+        id: docs
         run: |
-          git pull --ff-only origin ${GITHUB_REF#refs/heads/}
-          git commit --message="Update default gems list at ${GITHUB_SHA:0:30} [ci skip]" NEWS.md
-          git push origin ${GITHUB_REF#refs/heads/}
-        env:
-          EMAIL: svn-admin@ruby-lang.org
-          GIT_AUTHOR_NAME: git
-          GIT_COMMITTER_NAME: git
+          make XRUBY=ruby RDOC_DEPENDS= RBCONFIG=update-rbconfig HTMLOUT=html html
+          echo htmlout=ruby-html-${GITHUB_SHA:0:10} >> $GITHUB_OUTPUT
+        # Generate only when document commit/PR
         if: >-
-          ${{
-          github.repository == 'ruby/ruby' &&
-          !startsWith(github.event_name, 'pull') &&
-          steps.diff.outputs.update
+          ${{false
+          || contains(github.event.head_commit.message, '[ruby/rdoc]')
+          || contains(github.event.head_commit.message, '[DOC]')
+          || contains(github.event.pull_request.title, '[DOC]')
+          || contains(github.event.pull_request.labels.*.name, 'Documentation')
           }}
 
+      - name: Upload docs
+        uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7.0.1
+        with:
+          path: html
+          name: ${{ steps.docs.outputs.htmlout }}
+        if: ${{ steps.docs.outcome == 'success' }}
+
       - uses: ./.github/actions/slack
         with:
           SLACK_WEBHOOK_URL: ${{ secrets.SIMPLER_ALERTS_URL }} # ruby-lang slack: ruby/simpler-alerts-bot
diff --git a/.github/workflows/check_sast.yml b/.github/workflows/check_sast.yml
new file mode 100644
index 0000000000..c8db1103ed
--- /dev/null
+++ b/.github/workflows/check_sast.yml
@@ -0,0 +1,133 @@
+name: 'Check SAST tool'
+
+on:
+  push:
+    branches: ['master']
+    paths-ignore:
+      - 'doc/**'
+      - '**/man/*'
+      - '**.md'
+      - '**.rdoc'
+      - '**/.document'
+      - '.*.yml'
+  pull_request:
+    paths-ignore:
+      - 'doc/**'
+      - '**/man/*'
+      - '**.md'
+      - '**.rdoc'
+      - '**/.document'
+      - '.*.yml'
+  schedule:
+    - cron: '0 12 * * *'
+  workflow_dispatch:
+
+concurrency:
+  group: ${{ github.workflow }} / ${{ startsWith(github.event_name, 'pull') && github.ref_name || github.sha }}
+  cancel-in-progress: ${{ startsWith(github.event_name, 'pull') }}
+
+permissions: # added using https://github.com/step-security/secure-workflows
+  contents: read
+
+jobs:
+  zizmor:
+    name: zizmor
+
+    runs-on: ubuntu-latest
+
+    permissions:
+      contents: read
+      security-events: write
+
+    steps:
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with:
+          persist-credentials: false
+
+      - name: Run zizmor
+        uses: zizmorcore/zizmor-action@5f14fd08f7cf1cb1609c1e344975f152c7ee938d # v0.5.6
+        continue-on-error: true
+
+  analyze:
+    name: Analyze
+    runs-on: ubuntu-latest
+    permissions:
+      actions: read # for github/codeql-action/init to get workflow details
+      contents: read # for actions/checkout to fetch code
+      security-events: write # for github/codeql-action/upload-sarif to send a status report
+    # CodeQL fails to run pull requests from dependabot due to missing write access to upload results.
+    if: >-
+      ${{!(false
+      || contains(github.event.head_commit.message, '[DOC]')
+      || contains(github.event.pull_request.title, '[DOC]')
+      || contains(github.event.pull_request.labels.*.name, 'Documentation')
+      || (github.event.pull_request.user.login == 'dependabot[bot]')
+      )}}
+
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - language: cpp
+          - language: ruby
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with:
+          persist-credentials: false
+
+      - name: Initialize CodeQL
+        uses: github/codeql-action/init@8aad20d150bbac5944a9f9d289da16a4b0d87c1e # v4.36.2
+        with:
+          languages: ${{ matrix.language }}
+          build-mode: none
+          config-file: .github/codeql/codeql-config.yml
+
+      - name: Perform CodeQL Analysis
+        uses: github/codeql-action/analyze@8aad20d150bbac5944a9f9d289da16a4b0d87c1e # v4.36.2
+        with:
+          category: '/language:${{ matrix.language }}'
+          upload: False
+          output: sarif-results
+
+      - name: filter-sarif
+        uses: advanced-security/filter-sarif@2da736ff05ef065cb2894ac6892e47b5eac2c3c0 # v1.1
+        with:
+          patterns: |
+            +**/*.rb
+            -lib/uri/mailto.rb:rb/overly-large-range
+            -lib/uri/rfc3986_parser.rb:rb/overly-large-range
+            -lib/bundler/vendor/uri/lib/uri/mailto.rb:rb/overly-large-range
+            -lib/bundler/vendor/uri/lib/uri/rfc3986_parser.rb:rb/overly-large-range
+            -spec/ruby/core/regexp/timeout_spec.rb:rb/redos
+            -test/ruby/test_io.rb:rb/non-constant-kernel-open
+            -test/open-uri/test_open-uri.rb:rb/non-constant-kernel-open
+            -test/open-uri/test_ssl.rb:rb/non-constant-kernel-open
+            -spec/ruby/core/io/binread_spec.rb:rb/non-constant-kernel-open
+            -spec/ruby/core/io/readlines_spec.rb:rb/non-constant-kernel-open
+            -spec/ruby/core/io/foreach_spec.rb:rb/non-constant-kernel-open
+            -spec/ruby/core/io/write_spec.rb:rb/non-constant-kernel-open
+            -spec/ruby/core/io/read_spec.rb:rb/non-constant-kernel-open
+            -spec/ruby/core/kernel/open_spec.rb:rb/non-constant-kernel-open
+          input: sarif-results/${{ matrix.language }}.sarif
+          output: sarif-results/${{ matrix.language }}.sarif
+        if: ${{ matrix.language == 'ruby' }}
+        continue-on-error: true
+
+      - name: filter-sarif
+        uses: advanced-security/filter-sarif@2da736ff05ef065cb2894ac6892e47b5eac2c3c0 # v1.1
+        with:
+          patterns: |
+            +**/*.c
+            +**/*.h
+          input: sarif-results/${{ matrix.language }}.sarif
+          output: sarif-results/${{ matrix.language }}.sarif
+        if: ${{ matrix.language == 'cpp' }}
+        continue-on-error: true
+
+      - name: Upload SARIF
+        uses: github/codeql-action/upload-sarif@8aad20d150bbac5944a9f9d289da16a4b0d87c1e # v4.36.2
+        with:
+          sarif_file: sarif-results/${{ matrix.language }}.sarif
+        continue-on-error: true
diff --git a/.github/workflows/codeql-analysis.yml b/.github/workflows/codeql-analysis.yml
deleted file mode 100644
index 4c6e9fd639..0000000000
--- a/.github/workflows/codeql-analysis.yml
+++ /dev/null
@@ -1,111 +0,0 @@
-name: 'CodeQL'
-
-on:
-  push:
-    branches: ['master']
-    paths-ignore:
-      - 'doc/**'
-      - '**/man'
-      - '**.md'
-      - '**.rdoc'
-      - '**/.document'
-  pull_request:
-    paths-ignore:
-      - 'doc/**'
-      - '**/man'
-      - '**.md'
-      - '**.rdoc'
-      - '**/.document'
-  schedule:
-    - cron: '0 12 * * *'
-  workflow_dispatch:
-
-concurrency:
-  group: ${{ github.workflow }} / ${{ startsWith(github.event_name, 'pull') && github.ref_name || github.sha }}
-  cancel-in-progress: ${{ startsWith(github.event_name, 'pull') }}
-
-permissions: # added using https://github.com/step-security/secure-workflows
-  contents: read
-
-jobs:
-  analyze:
-    name: Analyze
-    runs-on: ubuntu-latest
-    permissions:
-      actions: read # for github/codeql-action/init to get workflow details
-      contents: read # for actions/checkout to fetch code
-      security-events: write # for github/codeql-action/autobuild to send a status report
-    # CodeQL fails to run pull requests from dependabot due to missing write access to upload results.
-    if: >-
-      ${{!(false
-      || contains(github.event.head_commit.message, '[DOC]')
-      || contains(github.event.pull_request.title, '[DOC]')
-      || contains(github.event.pull_request.labels.*.name, 'Documentation')
-      || (github.event_name == 'push' && github.actor == 'dependabot[bot]')
-      )}}
-
-    env:
-      enable_install_doc: no
-
-    strategy:
-      fail-fast: false
-      matrix:
-        language: ['cpp', 'ruby']
-
-    steps:
-      - name: Checkout repository
-        uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4.1.1
-
-      - name: Install libraries
-        uses: ./.github/actions/setup/ubuntu
-
-      - uses: ./.github/actions/setup/directories
-
-      - name: Remove an obsolete rubygems vendored file
-        run: sudo rm /usr/lib/ruby/vendor_ruby/rubygems/defaults/operating_system.rb
-
-      - name: Initialize CodeQL
-        uses: github/codeql-action/init@cdcdbb579706841c47f7063dda365e292e5cad7a # v2.13.4
-        with:
-          languages: ${{ matrix.language }}
-
-      - name: Autobuild
-        uses: github/codeql-action/autobuild@cdcdbb579706841c47f7063dda365e292e5cad7a # v2.13.4
-
-      - name: Perform CodeQL Analysis
-        uses: github/codeql-action/analyze@cdcdbb579706841c47f7063dda365e292e5cad7a # v2.13.4
-        with:
-          category: '/language:${{ matrix.language }}'
-          upload: False
-          output: sarif-results
-          ram: 8192
-        # CodeQL randomly hits `OutOfMemoryError "Java heap space"`.
-        # GitHub recommends running a larger runner to fix it, but we don't pay for it.
-        continue-on-error: true
-
-      - name: filter-sarif
-        uses: advanced-security/filter-sarif@f3b8118a9349d88f7b1c0c488476411145b6270d # v1.0
-        with:
-          patterns: |
-            +**/*.rb
-            -lib/uri/mailto.rb:rb/overly-large-range
-            -lib/uri/rfc3986_parser.rb:rb/overly-large-range
-            -lib/bundler/vendor/uri/lib/uri/mailto.rb:rb/overly-large-range
-            -lib/bundler/vendor/uri/lib/uri/rfc3986_parser.rb:rb/overly-large-range
-            -test/ruby/test_io.rb:rb/non-constant-kernel-open
-            -test/open-uri/test_open-uri.rb:rb/non-constant-kernel-open
-            -test/open-uri/test_ssl.rb:rb/non-constant-kernel-open
-            -spec/ruby/core/io/binread_spec.rb:rb/non-constant-kernel-open
-            -spec/ruby/core/io/readlines_spec.rb:rb/non-constant-kernel-open
-            -spec/ruby/core/io/foreach_spec.rb:rb/non-constant-kernel-open
-            -spec/ruby/core/io/write_spec.rb:rb/non-constant-kernel-open
-            -spec/ruby/core/io/read_spec.rb:rb/non-constant-kernel-open
-            -spec/ruby/core/kernel/open_spec.rb:rb/non-constant-kernel-open
-          input: sarif-results/${{ matrix.language }}.sarif
-          output: sarif-results/${{ matrix.language }}.sarif
-        if: ${{ matrix.language == 'ruby' }}
-
-      - name: Upload SARIF
-        uses: github/codeql-action/upload-sarif@cdcdbb579706841c47f7063dda365e292e5cad7a # v2.13.4
-        with:
-          sarif_file: sarif-results/${{ matrix.language }}.sarif
diff --git a/.github/workflows/compilers.yml b/.github/workflows/compilers.yml
index 0262c70ef8..f747b7fd03 100644
--- a/.github/workflows/compilers.yml
+++ b/.github/workflows/compilers.yml
@@ -1,292 +1,332 @@
+# Some tests depending on this name 'Compilations' via $GITHUB_WORKFLOW. Make sure to update such tests when renaming this workflow.
 name: Compilations
 
 on:
   push:
     paths-ignore:
       - 'doc/**'
-      - '**/man'
+      - '**/man/*'
       - '**.md'
       - '**.rdoc'
       - '**/.document'
+      - '.*.yml'
   pull_request:
     paths-ignore:
       - 'doc/**'
-      - '**/man'
+      - '**/man/*'
       - '**.md'
       - '**.rdoc'
       - '**/.document'
+      - '.*.yml'
   merge_group:
-    paths-ignore:
-      - 'doc/**'
-      - '**/man'
-      - '**.md'
-      - '**.rdoc'
-      - '**/.document'
 
 concurrency:
   group: ${{ github.workflow }} / ${{ startsWith(github.event_name, 'pull') && github.ref_name || github.sha }}
   cancel-in-progress: ${{ startsWith(github.event_name, 'pull') }}
 
-# GitHub actions does not support YAML anchors.  This creative use of
-# environment variables (plus the "echo $GITHUB_ENV" hack) is to reroute that
-# restriction.
-env:
-  default_cc: clang-17
-  append_cc: ''
-
-  # -O1 is faster than -O3 in our tests... Majority of time are consumed trying
-  # to optimize binaries.  Also GitHub Actions run on relatively modern CPUs
-  # compared to, say, GCC 4 or Clang 3.  We don't specify `-march=native`
-  # because compilers tend not understand what the CPU is.
-  optflags: '-O1'
-
-  # -g0 disables backtraces when SEGV.  Do not set that.
-  debugflags: '-ggdb3'
-
-  default_configure: >-
-    --enable-debug-env
-    --disable-install-doc
-    --with-ext=-test-/cxxanyargs,+
-  append_configure: >-
-    --without-valgrind
-    --without-jemalloc
-    --without-gmp
-
-  CONFIGURE_TTY: never
-  GITPULLOPTIONS: --no-tags origin ${{ github.ref }}
-  RUBY_DEBUG: ci rgengc
-  RUBY_TESTOPTS: >-
-    -q
-    --color=always
-    --tty=no
-
 permissions:
   contents: read
 
+# Each job is split so that they roughly take 30min to run through.
 jobs:
-  compile:
-    strategy:
-      fail-fast: false
-      matrix:
-        env:
-          - {}
-        entry:
-          - { name: gcc-13,    env: { default_cc: gcc-13 } }
-          - { name: gcc-12,    env: { default_cc: gcc-12 } }
-          - { name: gcc-11,    env: { default_cc: gcc-11 } }
-          - { name: gcc-10,    env: { default_cc: gcc-10 } }
-          - { name: gcc-9,     env: { default_cc: gcc-9 } }
-          - { name: gcc-8,     env: { default_cc: gcc-8 } }
-          - { name: gcc-7,     env: { default_cc: gcc-7 } }
-          - name: 'gcc-13 LTO'
-            container: gcc-13
-            env:
-              default_cc: 'gcc-13 -flto=auto -ffat-lto-objects -Werror=lto-type-mismatch'
-              optflags: '-O2'
-            shared: disable
-            # check: true
-          - { name: clang-18,  env: { default_cc: clang-18 } }
-          - { name: clang-17,  env: { default_cc: clang-17 } }
-          - { name: clang-16,  env: { default_cc: clang-16 } }
-          - { name: clang-15,  env: { default_cc: clang-15 } }
-          - { name: clang-14,  env: { default_cc: clang-14 } }
-          - { name: clang-13,  env: { default_cc: clang-13 } }
-          - { name: clang-12,  env: { default_cc: clang-12 } }
-          - { name: clang-11,  env: { default_cc: clang-11 } }
-          - { name: clang-10,  env: { default_cc: clang-10 } }
-          # llvm-objcopy<=9 doesn't have --wildcard. It compiles, but leaves Rust symbols in libyjit.o.
-          - { name: clang-9,   env: { default_cc: clang-9,   append_configure: '--disable-yjit' } }
-          - { name: clang-8,   env: { default_cc: clang-8,   append_configure: '--disable-yjit' } }
-          - { name: clang-7,   env: { default_cc: clang-7,   append_configure: '--disable-yjit' } }
-          - { name: clang-6.0, env: { default_cc: clang-6.0, append_configure: '--disable-yjit' } }
-          - name: 'clang-16 LTO'
-            container: clang-16
-            env:
-              default_cc: 'clang-16 -flto=auto'
-              optflags: '-O2'
-            shared: disable
-            # check: true
-
-          - { name: ext/Setup }
-
-#         - { name: aarch64-linux-gnu,     crosshost: aarch64-linux-gnu, container: crossbuild-essential-arm64 }
-#         - { name: arm-linux-gnueabi,     crosshost: arm-linux-gnueabi }
-#         - { name: arm-linux-gnueabihf,   crosshost: arm-linux-gnueabihf }
-#         - { name: i686-w64-mingw32,      crosshost: i686-w64-mingw32 }
-#         - { name: powerpc-linux-gnu,     crosshost: powerpc-linux-gnu }
-#         - { name: powerpc64le-linux-gnu, crosshost: powerpc64le-linux-gnu, container: crossbuild-essential-ppc64el }
-#         - { name: s390x-linux-gnu,       crosshost: s390x-linux-gnu, container: crossbuild-essential-s390x }
-#         - { name: x86_64-w64-mingw32,    crosshost: x86_64-w64-mingw32, container: mingw-w64 }
-
-          # -Wno-strict-prototypes is necessary with current clang-15 since
-          # older autoconf generate functions without prototype and -pedantic
-          # now implies strict-prototypes. Disabling the error but leaving the
-          # warning generates a lot of noise from use of ANYARGS in
-          # rb_define_method() and friends.
-          # See: https://github.com/llvm/llvm-project/commit/11da1b53d8cd3507959022cd790d5a7ad4573d94
-          - { name: c99,   env: { CFLAGS:   '-std=c99   -Werror=pedantic -pedantic-errors -Wno-strict-prototypes' } }
-#         - { name: c11,   env: { CFLAGS:   '-std=c11   -Werror=pedantic -pedantic-errors -Wno-strict-prototypes' } }
-#         - { name: c17,   env: { CFLAGS:   '-std=c17   -Werror=pedantic -pedantic-errors -Wno-strict-prototypes' } }
-          - { name: c23,   env: { CFLAGS:   '-std=c2x   -Werror=pedantic -pedantic-errors -Wno-strict-prototypes' } }
-          - { name: c++98, env: { CXXFLAGS: '-std=c++98 -Werror=pedantic -pedantic-errors -Wno-c++11-long-long' } }
-#         - { name: c++11, env: { CXXFLAGS: '-std=c++11 -Werror=pedantic -pedantic-errors -Wno-c++11-long-long' } }
-#         - { name: c++14, env: { CXXFLAGS: '-std=c++14 -Werror=pedantic -pedantic-errors -Wno-c++11-long-long' } }
-#         - { name: c++17, env: { CXXFLAGS: '-std=c++17 -Werror=pedantic -pedantic-errors -Wno-c++11-long-long' } }
-#         - { name: c++20, env: { CXXFLAGS: '-std=c++20 -Werror=pedantic -pedantic-errors -Wno-c++11-long-long' } }
-#         - { name: c++23, env: { CXXFLAGS: '-std=c++23 -Werror=pedantic -pedantic-errors -Wno-c++11-long-long' } }
-          - { name: c++26, env: { CXXFLAGS: '-std=c++26 -Werror=pedantic -pedantic-errors -Wno-c++11-long-long' } }
-
-          - { name: '-O0', env: { optflags: '-O0 -march=x86-64 -mtune=generic' } }
-#         - { name: '-O3', env: { optflags: '-O3 -march=x86-64 -mtune=generic' }, check: true }
-
-          - { name: gmp,                  env: { append_configure: '--with-gmp' } }
-          - { name: jemalloc,             env: { append_configure: '--with-jemalloc' } }
-          - { name: valgrind,             env: { append_configure: '--with-valgrind' } }
-          - { name: 'coroutine=ucontext', env: { append_configure: '--with-coroutine=ucontext' } }
-          - { name: 'coroutine=pthread',  env: { append_configure: '--with-coroutine=pthread' } }
-          - { name: disable-jit,          env: { append_configure: '--disable-yjit --disable-rjit' } }
-          - { name: disable-dln,          env: { append_configure: '--disable-dln' } }
-          - { name: enable-mkmf-verbose,  env: { append_configure: '--enable-mkmf-verbose' } }
-          - { name: disable-rubygems,     env: { append_configure: '--disable-rubygems' } }
-          - { name: RUBY_DEVEL,           env: { append_configure: '--enable-devel' } }
-
-          - { name: OPT_THREADED_CODE=1,            env: { cppflags: '-DOPT_THREADED_CODE=1' } }
-          - { name: OPT_THREADED_CODE=2,            env: { cppflags: '-DOPT_THREADED_CODE=2' } }
-          - { name: OPT_THREADED_CODE=3,            env: { cppflags: '-DOPT_THREADED_CODE=3' } }
-
-          - { name: NDEBUG,                         env: { cppflags: '-DNDEBUG' } }
-          - { name: RUBY_DEBUG,                     env: { cppflags: '-DRUBY_DEBUG' } }
-#         - { name: ARRAY_DEBUG,                    env: { cppflags: '-DARRAY_DEBUG' } }
-#         - { name: BIGNUM_DEBUG,                   env: { cppflags: '-DBIGNUM_DEBUG' } }
-#         - { name: CCAN_LIST_DEBUG,                env: { cppflags: '-DCCAN_LIST_DEBUG' } }
-#         - { name: CPDEBUG=-1,                     env: { cppflags: '-DCPDEBUG=-1' } }
-#         - { name: ENC_DEBUG,                      env: { cppflags: '-DENC_DEBUG' } }
-#         - { name: GC_DEBUG,                       env: { cppflags: '-DGC_DEBUG' } }
-#         - { name: HASH_DEBUG,                     env: { cppflags: '-DHASH_DEBUG' } }
-#         - { name: ID_TABLE_DEBUG,                 env: { cppflags: '-DID_TABLE_DEBUG' } }
-#         - { name: RGENGC_DEBUG=-1,                env: { cppflags: '-DRGENGC_DEBUG=-1' } }
-#         - { name: SYMBOL_DEBUG,                   env: { cppflags: '-DSYMBOL_DEBUG' } }
-
-#         - { name: RGENGC_CHECK_MODE,              env: { cppflags: '-DRGENGC_CHECK_MODE' } }
-#         - { name: VM_CHECK_MODE,                  env: { cppflags: '-DVM_CHECK_MODE' } }
-
-#         - { name: USE_EMBED_CI=0,                 env: { cppflags: '-DUSE_EMBED_CI=0' } }
-          - name: USE_FLONUM=0
-            env:
-              cppflags: '-DUSE_FLONUM=0'
-              # yjit requires FLONUM for the pointer tagging scheme
-              append_configure: '--disable-yjit'
-#         - { name: USE_GC_MALLOC_OBJ_INFO_DETAILS, env: { cppflags: '-DUSE_GC_MALLOC_OBJ_INFO_DETAILS' } }
-#         - { name: USE_LAZY_LOAD,                  env: { cppflags: '-DUSE_LAZY_LOAD' } }
-#         - { name: USE_SYMBOL_GC=0,                env: { cppflags: '-DUSE_SYMBOL_GC=0' } }
-#         - { name: USE_THREAD_CACHE=0,             env: { cppflags: '-DUSE_THREAD_CACHE=0' } }
-          - { name: USE_RUBY_DEBUG_LOG=1,           env: { cppflags: '-DUSE_RUBY_DEBUG_LOG=1' } }
-#         - { name: USE_DEBUG_COUNTER,              env: { cppflags: '-DUSE_DEBUG_COUNTER=1', RUBY_DEBUG_COUNTER_DISABLE: '1' } }
-          - { name: SHARABLE_MIDDLE_SUBSTRING,      env: { cppflags: '-DSHARABLE_MIDDLE_SUBSTRING=1' } }
-
-#         - { name: DEBUG_FIND_TIME_NUMGUESS,       env: { cppflags: '-DDEBUG_FIND_TIME_NUMGUESS' } }
-#         - { name: DEBUG_INTEGER_PACK,             env: { cppflags: '-DDEBUG_INTEGER_PACK' } }
-#         - { name: ENABLE_PATH_CHECK,              env: { cppflags: '-DENABLE_PATH_CHECK' } }
-
-#         - { name: GC_DEBUG_STRESS_TO_CLASS,       env: { cppflags: '-DGC_DEBUG_STRESS_TO_CLASS' } }
-#         - { name: GC_ENABLE_LAZY_SWEEP=0,         env: { cppflags: '-DGC_ENABLE_LAZY_SWEEP=0' } }
-#         - { name: GC_PROFILE_DETAIL_MEMOTY,       env: { cppflags: '-DGC_PROFILE_DETAIL_MEMOTY' } }
-#         - { name: GC_PROFILE_MORE_DETAIL,         env: { cppflags: '-DGC_PROFILE_MORE_DETAIL' } }
-
-#         - { name: CALC_EXACT_MALLOC_SIZE,         env: { cppflags: '-DCALC_EXACT_MALLOC_SIZE' } }
-#         - { name: MALLOC_ALLOCATED_SIZE_CHECK,    env: { cppflags: '-DMALLOC_ALLOCATED_SIZE_CHECK' } }
-
-#         - { name: IBF_ISEQ_ENABLE_LOCAL_BUFFER,   env: { cppflags: '-DIBF_ISEQ_ENABLE_LOCAL_BUFFER' } }
-
-#         - { name: RGENGC_ESTIMATE_OLDMALLOC,      env: { cppflags: '-DRGENGC_ESTIMATE_OLDMALLOC' } }
-#         - { name: RGENGC_FORCE_MAJOR_GC,          env: { cppflags: '-DRGENGC_FORCE_MAJOR_GC' } }
-#         - { name: RGENGC_OBJ_INFO,                env: { cppflags: '-DRGENGC_OBJ_INFO' } }
-#         - { name: RGENGC_PROFILE,                 env: { cppflags: '-DRGENGC_PROFILE' } }
-
-#         - { name: VM_DEBUG_BP_CHECK,              env: { cppflags: '-DVM_DEBUG_BP_CHECK' } }
-#         - { name: VM_DEBUG_VERIFY_METHOD_CACHE,   env: { cppflags: '-DVM_DEBUG_VERIFY_METHOD_CACHE' } }
-
-          - { name: enable-yjit,                    env: { append_configure: '--enable-yjit --disable-rjit' } }
-          - { name: enable-rjit,                    env: { append_configure: '--enable-rjit --disable-yjit' } }
-          - { name: YJIT_FORCE_ENABLE,              env: { cppflags: '-DYJIT_FORCE_ENABLE' } }
-#         - { name: RJIT_FORCE_ENABLE,              env: { cppflags: '-DRJIT_FORCE_ENABLE' } }
-          - { name: UNIVERSAL_PARSER,               env: { cppflags: '-DUNIVERSAL_PARSER' } }
-
-    name: ${{ matrix.entry.name }}
-
+  compile-if:
+    name: 'omnibus compilations, trigger'
     runs-on: ubuntu-latest
-
-    container:
-      image: ghcr.io/ruby/ruby-ci-image:${{ matrix.entry.container || matrix.entry.env.default_cc || 'clang-17' }}
-      options: --user root
-
     if: >-
       ${{!(false
       || contains(github.event.head_commit.message, '[DOC]')
       || contains(github.event.pull_request.title, '[DOC]')
       || contains(github.event.pull_request.labels.*.name, 'Documentation')
-      || (github.event_name == 'push' && github.actor == 'dependabot[bot]')
+      || (github.event.pull_request.user.login == 'dependabot[bot]')
       )}}
-
-    env: ${{ matrix.entry.env || matrix.env }}
-
     steps:
-      - run: id
+      - run: true
         working-directory:
 
-      - uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4.1.1
-        with:
-          sparse-checkout-cone-mode: false
-          sparse-checkout: /.github
+  compile1:
+    name: 'omnibus compilations, #1'
+    runs-on: ubuntu-latest
+    needs: compile-if
+    if: ${{ needs.compile-if.result == 'success' }}
+    timeout-minutes: 60
 
-      - uses: ./.github/actions/setup/directories
+    steps:
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with: { sparse-checkout-cone-mode: false, sparse-checkout: /.github, persist-credentials: false }
+      # Set fetch-depth: 10 so that Launchable can receive commits information.
+      - { uses: './.github/actions/setup/directories', with: { srcdir: 'src', builddir: 'build', makeup: true, fetch-depth: 10 } }
+      - name: 'clang 22 LTO'
+        uses: './.github/actions/compilers'
         with:
-          srcdir: src
-          builddir: build
-          makeup: true
+          tag: clang-22
+          with_gcc: 'clang-22 -flto=auto'
+          optflags: '-O2'
+          enable_shared: false
+        timeout-minutes: 30
+      - { uses: './.github/actions/compilers', name: '-O0', with: { optflags: '-O0 -march=x86-64 -mtune=generic' }, timeout-minutes: 5 }
+      # - { uses: './.github/actions/compilers', name: '-O3', with: { optflags: '-O3 -march=x86-64 -mtune=generic', check: true } }
+
+  compile2:
+    name: 'omnibus compilations, #2'
+    runs-on: ubuntu-latest
+    needs: compile-if
+    if: ${{ needs.compile-if.result == 'success' }}
+    timeout-minutes: 60
 
-      - name: Run configure
-        run: >
-          ../src/configure -C ${default_configure} ${append_configure}
-          --${{
-            matrix.entry.crosshost && 'host' || 'with-gcc'
-          }}=${{
-            matrix.entry.crosshost || '"${default_cc}${append_cc:+ $append_cc}"'
-          }}
-          --${{ matrix.entry.shared || 'enable' }}-shared
+    steps:
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with: { sparse-checkout-cone-mode: false, sparse-checkout: /.github, persist-credentials: false }
+      - { uses: './.github/actions/setup/directories', with: { srcdir: 'src', builddir: 'build', makeup: true, fetch-depth: 10 } }
+      - name: 'GCC 15 LTO'
+        uses: './.github/actions/compilers'
+        with:
+          tag: gcc-15
+          with_gcc: 'gcc-15 -flto=auto -ffat-lto-objects -Werror=lto-type-mismatch'
+          optflags: '-O2'
+          enable_shared: false
+        timeout-minutes: 10
+      - { uses: './.github/actions/compilers', name: 'ext/Setup', with: { static_exts: 'etc json/* */escape' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'GCC 15', with: { tag: 'gcc-15' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'GCC 14', with: { tag: 'gcc-14' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'GCC 13', with: { tag: 'gcc-13' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'GCC 12', with: { tag: 'gcc-12' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'GCC 11', with: { tag: 'gcc-11' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'GCC 10', with: { tag: 'gcc-10' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'GCC 9',  with: { tag: 'gcc-9'  }, timeout-minutes: 5 }
+
+  compile3:
+    name: 'omnibus compilations, #3'
+    runs-on: ubuntu-latest
+    needs: compile-if
+    if: ${{ needs.compile-if.result == 'success' }}
+    timeout-minutes: 60
 
-      - name: Add to ext/Setup # statically link just the etc extension
-        run: mkdir ext && echo etc >> ext/Setup
-        if: ${{ matrix.entry.name == 'ext/Setup' }}
+    steps:
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with: { sparse-checkout-cone-mode: false, sparse-checkout: /.github, persist-credentials: false }
+      - { uses: './.github/actions/setup/directories', with: { srcdir: 'src', builddir: 'build', makeup: true, fetch-depth: 10 } }
+      - { uses: './.github/actions/compilers', name: 'clang 20', with: { tag: 'clang-20' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'clang 19', with: { tag: 'clang-19' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'clang 18', with: { tag: 'clang-18' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'clang 17', with: { tag: 'clang-17' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'clang 16', with: { tag: 'clang-16' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'clang 15', with: { tag: 'clang-15' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'clang 14', with: { tag: 'clang-14' }, timeout-minutes: 5 }
+
+  compile4:
+    name: 'omnibus compilations, #4'
+    runs-on: ubuntu-latest
+    needs: compile-if
+    if: ${{ needs.compile-if.result == 'success' }}
+    timeout-minutes: 60
 
-      - run: make showflags
+    steps:
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with: { sparse-checkout-cone-mode: false, sparse-checkout: /.github, persist-credentials: false }
+      - { uses: './.github/actions/setup/directories', with: { srcdir: 'src', builddir: 'build', makeup: true, fetch-depth: 10 } }
+      - { uses: './.github/actions/compilers', name: 'clang 13', with: { tag: 'clang-13' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'clang 12', with: { tag: 'clang-12' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'clang 11', with: { tag: 'clang-11' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'clang 10', with: { tag: 'clang-10' }, timeout-minutes: 5 }
+        # llvm-objcopy<=9 doesn't have --wildcard. It compiles, but leaves Rust symbols in libyjit.o and fail `make test-leaked-globals`.
+      - { uses: './.github/actions/compilers', name: 'clang 9',  with: { tag: 'clang-9',   append_configure: '--disable-yjit --disable-zjit' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'clang 8',  with: { tag: 'clang-8',   append_configure: '--disable-yjit --disable-zjit' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'clang 7',  with: { tag: 'clang-7',   append_configure: '--disable-yjit --disable-zjit' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'clang 6',  with: { tag: 'clang-6.0', append_configure: '--disable-yjit --disable-zjit' }, timeout-minutes: 5 }
+
+  compile5:
+    name: 'omnibus compilations, #5'
+    runs-on: ubuntu-latest
+    needs: compile-if
+    if: ${{ needs.compile-if.result == 'success' }}
+    timeout-minutes: 60
 
-      - run: make
+    steps:
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with: { sparse-checkout-cone-mode: false, sparse-checkout: /.github, persist-credentials: false }
+      - { uses: './.github/actions/setup/directories', with: { srcdir: 'src', builddir: 'build', makeup: true, fetch-depth: 10 } }
+      # -Wno-strict-prototypes is necessary with current clang-15 since
+      # older autoconf generate functions without prototype and -pedantic
+      # now implies strict-prototypes. Disabling the error but leaving the
+      # warning generates a lot of noise from use of ANYARGS in
+      # rb_define_method() and friends.
+      # See: https://github.com/llvm/llvm-project/commit/11da1b53d8cd3507959022cd790d5a7ad4573d94
+      - { uses: './.github/actions/compilers', name: 'C99',      with: { CFLAGS: '-std=c99 -Werror=pedantic -pedantic-errors -Wno-strict-prototypes' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'C11',   with: { CFLAGS:   '-std=c11   -Werror=pedantic -pedantic-errors -Wno-strict-prototypes' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'C17',   with: { CFLAGS:   '-std=c17   -Werror=pedantic -pedantic-errors -Wno-strict-prototypes' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'C23',   with: { CFLAGS:   '-std=c2x   -Werror=pedantic -pedantic-errors -Wno-strict-prototypes' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'C++98', with: { CXXFLAGS: '-std=c++98 -Werror=pedantic -pedantic-errors -Wno-c++11-long-long' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'C++11', with: { CXXFLAGS: '-std=c++11 -Werror=pedantic -pedantic-errors -Wno-c++11-long-long' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'C++14', with: { CXXFLAGS: '-std=c++14 -Werror=pedantic -pedantic-errors -Wno-c++11-long-long' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'C++17', with: { CXXFLAGS: '-std=c++17 -Werror=pedantic -pedantic-errors -Wno-c++11-long-long' }, timeout-minutes: 5 }
+
+  compile6:
+    name: 'omnibus compilations, #6'
+    runs-on: ubuntu-latest
+    needs: compile-if
+    if: ${{ needs.compile-if.result == 'success' }}
+    timeout-minutes: 60
 
-      - run: make test
+    steps:
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with: { sparse-checkout-cone-mode: false, sparse-checkout: /.github, persist-credentials: false }
+      - { uses: './.github/actions/setup/directories', with: { srcdir: 'src', builddir: 'build', makeup: true, fetch-depth: 10 } }
+      - { uses: './.github/actions/compilers', name: 'C++20', with: { CXXFLAGS: '-std=c++20 -Werror=pedantic -pedantic-errors -Wno-c++11-long-long' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'C++23', with: { CXXFLAGS: '-std=c++23 -Werror=pedantic -pedantic-errors -Wno-c++11-long-long' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'C++26', with: { CXXFLAGS: '-std=c++26 -Werror=pedantic -pedantic-errors -Wno-c++11-long-long' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'gmp',                 with: { append_configure: '--with-gmp', test_all: 'ruby/test_bignum.rb', test_spec: "/github/workspace/src/spec/ruby/core/integer" }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'jemalloc',            with: { append_configure: '--with-jemalloc' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'valgrind',            with: { append_configure: '--with-valgrind' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'coroutine=ucontext',  with: { append_configure: '--with-coroutine=ucontext' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'coroutine=pthread',   with: { append_configure: '--with-coroutine=pthread' }, timeout-minutes: 5 }
+
+  compile7:
+    name: 'omnibus compilations, #7'
+    runs-on: ubuntu-latest
+    needs: compile-if
+    if: ${{ needs.compile-if.result == 'success' }}
+    timeout-minutes: 60
 
-      - run: make install
-        if: ${{ matrix.entry.check }}
+    steps:
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with: { sparse-checkout-cone-mode: false, sparse-checkout: /.github, persist-credentials: false }
+      - { uses: './.github/actions/setup/directories', with: { srcdir: 'src', builddir: 'build', makeup: true, fetch-depth: 10 } }
+      - { uses: './.github/actions/compilers', name: 'disable-jit',         with: { append_configure: '--disable-yjit --disable-zjit' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'disable-yjit',        with: { append_configure: '--disable-yjit' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'disable-zjit',        with: { append_configure: '--disable-zjit' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'disable-dln',         with: { append_configure: '--disable-dln' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'enable-mkmf-verbose', with: { append_configure: '--enable-mkmf-verbose' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'disable-rubygems',    with: { append_configure: '--disable-rubygems' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'RUBY_DEVEL',          with: { append_configure: '--enable-devel' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'OPT_THREADED_CODE=0',            with: { cppflags: '-DOPT_THREADED_CODE=0' }, timeout-minutes: 5 }
+
+  compile8:
+    name: 'omnibus compilations, #8'
+    runs-on: ubuntu-latest
+    needs: compile-if
+    if: ${{ needs.compile-if.result == 'success' }}
+    timeout-minutes: 60
 
-      - run: make test-tool
-        if: ${{ matrix.entry.check }}
+    steps:
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with: { sparse-checkout-cone-mode: false, sparse-checkout: /.github, persist-credentials: false }
+      - { uses: './.github/actions/setup/directories', with: { srcdir: 'src', builddir: 'build', makeup: true, fetch-depth: 10 } }
+      - { uses: './.github/actions/compilers', name: 'NDEBUG',                         with: { cppflags: '-DNDEBUG' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'RUBY_DEBUG',                     with: { cppflags: '-DRUBY_DEBUG' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'ARRAY_DEBUG',                    with: { cppflags: '-DARRAY_DEBUG' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'CCAN_LIST_DEBUG',                with: { cppflags: '-DCCAN_LIST_DEBUG' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'CPDEBUG=-1',                     with: { cppflags: '-DCPDEBUG=-1' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'ENC_DEBUG',                      with: { cppflags: '-DENC_DEBUG' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'GC_DEBUG',                       with: { cppflags: '-DGC_DEBUG' }, timeout-minutes: 5 }
+
+  compile9:
+    name: 'omnibus compilations, #9'
+    runs-on: ubuntu-latest
+    needs: compile-if
+    if: ${{ needs.compile-if.result == 'success' }}
+    timeout-minutes: 60
 
-      - run: make test-all TESTS='-- ruby -ext-'
-        if: ${{ matrix.entry.check }}
+    steps:
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with: { sparse-checkout-cone-mode: false, sparse-checkout: /.github, persist-credentials: false }
+      - { uses: './.github/actions/setup/directories', with: { srcdir: 'src', builddir: 'build', makeup: true, fetch-depth: 10 } }
+      - { uses: './.github/actions/compilers', name: 'HASH_DEBUG',                     with: { cppflags: '-DHASH_DEBUG' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'ID_TABLE_DEBUG',                 with: { cppflags: '-DID_TABLE_DEBUG' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'RGENGC_DEBUG=-1',                with: { cppflags: '-DRGENGC_DEBUG=-1' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'SYMBOL_DEBUG',                   with: { cppflags: '-DSYMBOL_DEBUG' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'RGENGC_CHECK_MODE',              with: { cppflags: '-DRGENGC_CHECK_MODE' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'VM_CHECK_MODE',                  with: { cppflags: '-DVM_CHECK_MODE' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'USE_EMBED_CI=0',                 with: { cppflags: '-DUSE_EMBED_CI=0' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'USE_FLONUM=0',                   with: { cppflags: '-DUSE_FLONUM=0', append_configure: '--disable-yjit --disable-zjit' }, timeout-minutes: 5 }
+
+  compileX:
+    name: 'omnibus compilations, #10'
+    runs-on: ubuntu-latest
+    needs: compile-if
+    if: ${{ needs.compile-if.result == 'success' }}
+    timeout-minutes: 60
 
-      - run: make test-spec
-        env:
-          CHECK_LEAKS: true
-        if: ${{ matrix.entry.check }}
+    steps:
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with: { sparse-checkout-cone-mode: false, sparse-checkout: /.github, persist-credentials: false }
+      - { uses: './.github/actions/setup/directories', with: { srcdir: 'src', builddir: 'build', makeup: true, fetch-depth: 10 } }
+      - { uses: './.github/actions/compilers', name: 'USE_LAZY_LOAD',                  with: { cppflags: '-DUSE_LAZY_LOAD' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'USE_RUBY_DEBUG_LOG=1',           with: { cppflags: '-DUSE_RUBY_DEBUG_LOG=1' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'USE_DEBUG_COUNTER',              with: { cppflags: '-DUSE_DEBUG_COUNTER=1' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'SHARABLE_MIDDLE_SUBSTRING',      with: { cppflags: '-DSHARABLE_MIDDLE_SUBSTRING=1' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'DEBUG_FIND_TIME_NUMGUESS',       with: { cppflags: '-DDEBUG_FIND_TIME_NUMGUESS' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'DEBUG_INTEGER_PACK',             with: { cppflags: '-DDEBUG_INTEGER_PACK' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'OPT_THREADED_CODE=1',            with: { cppflags: '-DOPT_THREADED_CODE=1' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'OPT_THREADED_CODE=2',            with: { cppflags: '-DOPT_THREADED_CODE=2' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'clang 21', with: { tag: 'clang-21' }, timeout-minutes: 5 }
+
+  compileB:
+    name: 'omnibus compilations, #11'
+    runs-on: ubuntu-latest
+    needs: compile-if
+    if: ${{ needs.compile-if.result == 'success' }}
+    timeout-minutes: 60
 
-      - run: make test-annocheck
-        if: ${{ matrix.entry.check && endsWith(matrix.entry.name, 'annocheck') }}
+    steps:
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with: { sparse-checkout-cone-mode: false, sparse-checkout: /.github, persist-credentials: false }
+      - { uses: './.github/actions/setup/directories', with: { srcdir: 'src', builddir: 'build', makeup: true, fetch-depth: 10 } }
+      - { uses: './.github/actions/compilers', name: 'GC_DEBUG_STRESS_TO_CLASS',       with: { cppflags: '-DGC_DEBUG_STRESS_TO_CLASS' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'GC_ENABLE_LAZY_SWEEP=0',         with: { cppflags: '-DGC_ENABLE_LAZY_SWEEP=0' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'GC_PROFILE_DETAIL_MEMORY',       with: { cppflags: '-DGC_PROFILE_DETAIL_MEMORY' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'GC_PROFILE_MORE_DETAIL',         with: { cppflags: '-DGC_PROFILE_MORE_DETAIL' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'MALLOC_ALLOCATED_SIZE_CHECK',    with: { cppflags: '-DMALLOC_ALLOCATED_SIZE_CHECK' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'RGENGC_ESTIMATE_OLDMALLOC',      with: { cppflags: '-DRGENGC_ESTIMATE_OLDMALLOC' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'RGENGC_PROFILE',                 with: { cppflags: '-DRGENGC_PROFILE' }, timeout-minutes: 5 }
+
+  compileC:
+    name: 'omnibus compilations, #12'
+    runs-on: ubuntu-latest
+    needs: compile-if
+    if: ${{ needs.compile-if.result == 'success' }}
+    timeout-minutes: 60
 
+    steps:
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with: { sparse-checkout-cone-mode: false, sparse-checkout: /.github, persist-credentials: false }
+      - { uses: './.github/actions/setup/directories', with: { srcdir: 'src', builddir: 'build', makeup: true, fetch-depth: 10 } }
+      - { uses: './.github/actions/compilers', name: 'VM_DEBUG_BP_CHECK',              with: { cppflags: '-DVM_DEBUG_BP_CHECK' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'VM_DEBUG_VERIFY_METHOD_CACHE',   with: { cppflags: '-DVM_DEBUG_VERIFY_METHOD_CACHE' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'YJIT_FORCE_ENABLE',              with: { cppflags: '-DYJIT_FORCE_ENABLE' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'UNIVERSAL_PARSER',               with: { cppflags: '-DUNIVERSAL_PARSER' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'clang 23', with: { tag: 'clang-23' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'clang 22', with: { tag: 'clang-22' }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'GCC 8',  with: { tag: 'gcc-8'  }, timeout-minutes: 5 }
+      - { uses: './.github/actions/compilers', name: 'GCC 7',  with: { tag: 'gcc-7'  }, timeout-minutes: 5 }
+
+  compilemax:
+    name: 'omnibus compilations, result'
+    runs-on: ubuntu-latest
+    if: ${{ always() }}
+    needs:
+      - 'compile1'
+      - 'compile2'
+      - 'compile3'
+      - 'compile4'
+      - 'compile5'
+      - 'compile6'
+      - 'compile7'
+      - 'compile8'
+      - 'compile9'
+      - 'compileX'
+      - 'compileB'
+      - 'compileC'
+    steps:
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with: { sparse-checkout-cone-mode: false, sparse-checkout: /.github, persist-credentials: false }
       - uses: ./.github/actions/slack
         with:
-          label: ${{ matrix.entry.name }}
+          label: 'omnibus'
           SLACK_WEBHOOK_URL: ${{ secrets.SIMPLER_ALERTS_URL }} # ruby-lang slack: ruby/simpler-alerts-bot
-        if: ${{ failure() }}
+        if: ${{ contains(needs.*.result, 'failure') || contains(needs.*.result, 'cancelled') }}
+      - run: false
+        working-directory:
+        if: ${{ contains(needs.*.result, 'failure') || contains(needs.*.result, 'cancelled') }}
 
 defaults:
   run:
diff --git a/.github/workflows/crosscompile.yml b/.github/workflows/crosscompile.yml
new file mode 100644
index 0000000000..3ed6429a1e
--- /dev/null
+++ b/.github/workflows/crosscompile.yml
@@ -0,0 +1,123 @@
+name: Cross compile
+on:
+  push:
+    paths-ignore:
+      - 'doc/**'
+      - '**/man/*'
+      - '**.md'
+      - '**.rdoc'
+      - '**/.document'
+      - '.*.yml'
+  pull_request:
+    # Do not use paths-ignore for required status checks
+    # https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/collaborating-on-repositories-with-code-quality-features/troubleshooting-required-status-checks
+  merge_group:
+
+concurrency:
+  group: ${{ github.workflow }} / ${{ startsWith(github.event_name, 'pull') && github.ref_name || github.sha }}
+  cancel-in-progress: ${{ startsWith(github.event_name, 'pull') }}
+
+permissions:
+  contents: read
+
+jobs:
+  make:
+    name: make (${{ matrix.host }} host on ${{ matrix.build }})
+    strategy:
+      matrix:
+        include:
+          - host: aarch64-linux-gnu
+            arch: arm64
+            build: x86_64-linux-gnu
+            runs-on: ubuntu-24.04
+            file_arch: ARM aarch64
+          - host: x86_64-linux-gnu
+            arch: amd64
+            build: aarch64-linux-gnu
+            runs-on: ubuntu-24.04-arm
+            file_arch: x86-64
+      fail-fast: false
+
+    env:
+      GITPULLOPTIONS: --no-tags origin ${{ github.ref }}
+
+    runs-on: ${{ matrix.runs-on }}
+
+    if: >-
+      ${{!(false
+      || contains(github.event.head_commit.message, '[DOC]')
+      || contains(github.event.pull_request.title, '[DOC]')
+      || contains(github.event.pull_request.labels.*.name, 'Documentation')
+      || (github.event.pull_request.user.login == 'dependabot[bot]')
+      )}}
+
+    steps:
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with:
+          sparse-checkout-cone-mode: false
+          sparse-checkout: /.github
+          persist-credentials: false
+
+      - uses: ./.github/actions/setup/directories
+        with:
+          srcdir: src
+          builddir: build
+          makeup: true
+
+      - name: Setup cross-compilation toolchain sources
+        run: |
+          native_arch=$(dpkg --print-architecture)
+          # Restrict existing sources to native arch
+          sudo sed -i '/^Architectures:/d' /etc/apt/sources.list.d/ubuntu.sources
+          sudo sed -i "/^Types:/a Architectures: ${native_arch}" /etc/apt/sources.list.d/ubuntu.sources
+          # Add cross-arch sources
+          if [ "${{ matrix.arch }}" = "arm64" ]; then
+            cross_uri="http://ports.ubuntu.com/"
+          else
+            cross_uri="http://archive.ubuntu.com/ubuntu/"
+          fi
+          printf '%s\n' \
+            "Types: deb" \
+            "URIs: ${cross_uri}" \
+            "Suites: noble noble-updates noble-security" \
+            "Components: main universe" \
+            "Architectures: ${{ matrix.arch }}" \
+            | sudo tee /etc/apt/sources.list.d/cross-${{ matrix.arch }}.sources
+
+      - uses: ./.github/actions/setup/ubuntu
+        with:
+          arch: ${{ matrix.arch }}
+
+      - uses: ./.github/actions/setup/baseruby
+        id: baseruby
+        with:
+          srcdir: src
+
+      - name: Run configure
+        run: >-
+          ../src/configure -C --disable-install-doc
+          --prefix=/usr
+          --build=${{ matrix.build }}
+          --host=${{ matrix.host }}
+          --with-baseruby="$baseruby"
+        env:
+          baseruby: ${{ steps.baseruby.outputs.ruby }}
+
+      - run: make
+
+      - run: make install DESTDIR=$PWD/install
+
+      - name: Verify cross-compiled binary
+        run: |
+          file install/usr/bin/ruby
+          file install/usr/bin/ruby | grep -q '${{ matrix.file_arch }}'
+
+      - uses: ./.github/actions/slack
+        with:
+          label: cross ${{ matrix.host }}
+          SLACK_WEBHOOK_URL: ${{ secrets.SIMPLER_ALERTS_URL }} # ruby-lang slack: ruby/simpler-alerts-bot
+        if: ${{ failure() }}
+
+defaults:
+  run:
+    working-directory: build
diff --git a/.github/workflows/cygwin.yml b/.github/workflows/cygwin.yml
new file mode 100644
index 0000000000..f1a6f79587
--- /dev/null
+++ b/.github/workflows/cygwin.yml
@@ -0,0 +1,75 @@
+name: Cygwin
+on:
+  push:
+    paths-ignore:
+      - 'doc/**'
+      - '**/man/*'
+      - '**.md'
+      - '**.rdoc'
+      - '**/.document'
+      - '.*.yml'
+  pull_request:
+    paths-ignore:
+      - 'doc/**'
+      - '**/man/*'
+      - '**.md'
+      - '**.rdoc'
+      - '**/.document'
+      - '.*.yml'
+  merge_group:
+
+concurrency:
+  group: ${{ github.workflow }} / ${{ startsWith(github.event_name, 'pull') && github.ref_name || github.sha }}
+  cancel-in-progress: ${{ startsWith(github.event_name, 'pull') }}
+
+permissions:
+  contents: read
+
+jobs:
+  make:
+    runs-on: windows-2022
+
+    if: >-
+      ${{!(false
+      || contains(github.event.head_commit.message, '[DOC]')
+      || contains(github.event.pull_request.title, '[DOC]')
+      || contains(github.event.pull_request.labels.*.name, 'Documentation')
+      || (github.event.pull_request.user.login == 'dependabot[bot]')
+      )}}
+
+    steps:
+      - run: git config --global core.autocrlf input
+
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with:
+          persist-credentials: false
+
+      - name: Setup Cygwin
+        uses: cygwin/cygwin-install-action@711d29f3da23c9f4a1798e369a6f01198c13b11a # v6.1
+        with:
+          packages: ruby gcc-core make autoconf libtool libssl-devel libyaml-devel libffi-devel zlib-devel rubygems
+          site: |
+            https://cygwin.osuosl.org/
+
+      - name: configure
+        run: |
+          ./autogen.sh
+          ./configure --disable-install-doc
+        shell: C:\cygwin\bin\bash.EXE --noprofile --norc -e -o igncr -o pipefail {0}
+
+      - name: Extract bundled gems
+        run: |
+          make ruby -j5
+          make extract-gems
+        shell: C:\cygwin\bin\bash.EXE --noprofile --norc -e -o igncr -o pipefail {0}
+
+      - name: make all
+        timeout-minutes: 30
+        run: make -j4 V=1
+        shell: C:\cygwin\bin\bash.EXE --noprofile --norc -e -o igncr -o pipefail {0}
+
+      - uses: ./.github/actions/slack
+        with:
+          label: Cygwin
+          SLACK_WEBHOOK_URL: ${{ secrets.SIMPLER_ALERTS_URL }} # ruby-lang slack: ruby/simpler-alerts-bot
+        if: ${{ failure() }}
diff --git a/.github/workflows/default_gems_list.yml b/.github/workflows/default_gems_list.yml
new file mode 100644
index 0000000000..68f2d18dd6
--- /dev/null
+++ b/.github/workflows/default_gems_list.yml
@@ -0,0 +1,99 @@
+name: Update default gems list
+on: [push, pull_request, merge_group]
+
+env:
+  UPDATE_NEWS_ENABLED: true
+
+concurrency:
+  group: ${{ github.workflow }} / ${{ startsWith(github.event_name, 'pull') && github.ref_name || github.sha }}
+  cancel-in-progress: ${{ startsWith(github.event_name, 'pull') }}
+
+permissions:
+  contents: read
+
+jobs:
+  update_default_gems_list:
+    name: Update default gems list
+
+    permissions:
+      contents: write # for Git to git push
+
+    runs-on: ubuntu-latest
+
+    if: ${{ github.repository == 'ruby/ruby' }}
+
+    steps:
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with:
+          token: ${{ (github.repository == 'ruby/ruby' && !startsWith(github.event_name, 'pull')) && secrets.MATZBOT_AUTO_UPDATE_TOKEN || secrets.GITHUB_TOKEN }}
+
+      - id: gems
+        run: true
+        if: ${{ github.ref == 'refs/heads/master' }}
+
+      - uses: ./.github/actions/setup/directories
+        with:
+          makeup: true
+          # Skip overwriting MATZBOT_AUTO_UPDATE_TOKEN
+          checkout: '' # false (ref: https://github.com/actions/runner/issues/2238)
+        if: ${{ steps.gems.outcome == 'success' }}
+
+      - name: Download previous gems list
+        run: |
+          data=default_gems.json
+          mkdir -p .downloaded-cache
+          ln -s .downloaded-cache/$data .
+          curl --retry 5 --retry-connrefused --retry-delay 2 --retry-max-time 60 -O -R -z ./$data https://stdgems.org/$data
+        if: ${{ steps.gems.outcome == 'success' }}
+
+      - name: Make default gems list
+        run: |
+          #!ruby
+          require 'rubygems'
+          $:.unshift "lib"
+          rgver = File.foreach("lib/rubygems.rb") do |line|
+            break $1 if /^\s*VERSION\s*=\s*"([^"]+)"/ =~ line
+          end
+          gems = Dir.glob("{ext,lib}/**/*.gemspec").map do |f|
+            spec = Gem::Specification.load(f)
+            "#{spec.name} #{spec.version}"
+          end.sort
+          File.open("gems/default_gems", "w") do |f|
+            f.puts "RubyGems #{rgver}"
+            f.puts gems
+          end
+        shell: ruby --disable=gems {0}
+        if: ${{ steps.gems.outcome == 'success' }}
+
+      - name: Maintain updated gems list in NEWS
+        run: |
+          ruby tool/update-NEWS-gemlist.rb default
+        if: ${{ steps.gems.outcome == 'success' && env.UPDATE_NEWS_ENABLED == 'true' }}
+
+      - name: Check diffs
+        id: diff
+        run: |
+          git diff --color --no-ext-diff --ignore-submodules --exit-code NEWS.md ||
+          echo update=true >> $GITHUB_OUTPUT
+        if: ${{ steps.gems.outcome == 'success' }}
+
+      - name: Commit
+        run: |
+          git pull --ff-only origin ${GITHUB_REF#refs/heads/}
+          git commit --message="Update default gems list at ${GITHUB_SHA:0:30} [ci skip]" NEWS.md
+          git push origin ${GITHUB_REF#refs/heads/}
+        env:
+          EMAIL: svn-admin@ruby-lang.org
+          GIT_AUTHOR_NAME: git
+          GIT_COMMITTER_NAME: git
+        if: >-
+          ${{
+          github.repository == 'ruby/ruby' &&
+          !startsWith(github.event_name, 'pull') &&
+          steps.diff.outputs.update
+          }}
+
+      - uses: ./.github/actions/slack
+        with:
+          SLACK_WEBHOOK_URL: ${{ secrets.SIMPLER_ALERTS_URL }} # ruby-lang slack: ruby/simpler-alerts-bot
+        if: ${{ failure() }}
diff --git a/.github/workflows/dependabot_automerge.yml b/.github/workflows/dependabot_automerge.yml
index 6259199b11..2e4dc8d7a2 100644
--- a/.github/workflows/dependabot_automerge.yml
+++ b/.github/workflows/dependabot_automerge.yml
@@ -1,23 +1,25 @@
 # from https://github.com/gofiber/swagger/blob/main/.github/workflows/dependabot_automerge.yml
 name: Dependabot auto-merge
 on:
-  pull_request_target:
+  pull_request:
+
+permissions:
+  contents: write
+  pull-requests: write
 
 jobs:
   automerge:
     runs-on: ubuntu-latest
-
-    if: ${{ github.actor == 'dependabot[bot]' }}
-
+    if: github.event.pull_request.user.login == 'dependabot[bot]' && github.repository == 'ruby/ruby'
     steps:
       - name: Dependabot metadata
-        uses: dependabot/fetch-metadata@c9c4182bf1b97f5224aee3906fd373f6b61b4526 # v1.6.0
+        uses: dependabot/fetch-metadata@25dd0e34f4fe68f24cc83900b1fe3fe149efef98 # v3.1.0
         id: metadata
 
       - name: Wait for status checks
-        uses: lewagon/wait-on-check-action@e106e5c43e8ca1edea6383a39a01c5ca495fd812 # v1.3.1
+        uses: lewagon/wait-on-check-action@9312864dfbc9fd208e9c0417843430751c042800 # v1.7.0
         with:
-          repo-token: ${{ secrets.MATZBOT_GITHUB_TOKEN }}
+          repo-token: ${{ secrets.GITHUB_TOKEN }}
           ref: ${{ github.event.pull_request.head.sha || github.sha }}
           check-regexp: 'make \(check, .*\)'
           wait-interval: 30
@@ -27,4 +29,4 @@ jobs:
         run: gh pr merge --auto --rebase "$PR_URL"
         env:
           PR_URL: ${{ github.event.pull_request.html_url }}
-          GITHUB_TOKEN: ${{ secrets.MATZBOT_GITHUB_TOKEN }}
+          GITHUB_TOKEN: ${{ secrets.MATZBOT_DEPENDABOT_MERGE_TOKEN }}
diff --git a/.github/workflows/labeler.yml b/.github/workflows/labeler.yml
new file mode 100644
index 0000000000..d0a8024b05
--- /dev/null
+++ b/.github/workflows/labeler.yml
@@ -0,0 +1,15 @@
+name: "Pull Request Labeler"
+on:
+- pull_request_target
+
+permissions:
+  contents: read
+
+jobs:
+  labeler:
+    permissions:
+      contents: read
+      pull-requests: write
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/labeler@f27b608878404679385c85cfa523b85ccb86e213 # v6.1.0
diff --git a/.github/workflows/macos.yml b/.github/workflows/macos.yml
index 363ef8566e..4f1807121f 100644
--- a/.github/workflows/macos.yml
+++ b/.github/workflows/macos.yml
@@ -3,20 +3,15 @@ on:
   push:
     paths-ignore:
       - 'doc/**'
-      - '**/man'
+      - '**/man/*'
       - '**.md'
       - '**.rdoc'
       - '**/.document'
+      - '.*.yml'
   pull_request:
     # Do not use paths-ignore for required status checks
     # https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/collaborating-on-repositories-with-code-quality-features/troubleshooting-required-status-checks#handling-skipped-but-required-checks
   merge_group:
-    paths-ignore:
-      - 'doc/**'
-      - '**/man'
-      - '**.md'
-      - '**.rdoc'
-      - '**/.document'
 
 concurrency:
   group: ${{ github.workflow }} / ${{ startsWith(github.event_name, 'pull') && github.ref_name || github.sha }}
@@ -29,9 +24,31 @@ jobs:
   make:
     strategy:
       matrix:
-        test_task: ['check']
-        configure: ['']
-        os: ${{ fromJSON(format('["macos-11","macos-12"{0}]', (github.repository == 'ruby/ruby' && ',"macos-arm-oss"' || ''))) }}
+        include:
+          - test_task: check
+            os: macos-26
+          - test_task: check
+            os: macos-15
+            configure_args: '--with-gcc=gcc-14'
+          - test_task: check
+            os: macos-26
+            configure_args: '--with-jemalloc --with-opt-dir=$(brew --prefix jemalloc)'
+          - test_task: check
+            os: macos-26
+            configure_args: '--with-gmp'
+          - test_task: test-all
+            test_opts: --repeat-count=2
+            os: macos-26
+          - test_task: test-bundler-parallel
+            os: macos-26
+          - test_task: test-bundled-gems
+            os: macos-26
+          - test_task: check
+            os: macos-15
+          - test_task: check
+            os: macos-15-intel
+          - test_task: check
+            os: macos-14
       fail-fast: false
 
     env:
@@ -44,14 +61,15 @@ jobs:
       || contains(github.event.head_commit.message, '[DOC]')
       || contains(github.event.pull_request.title, '[DOC]')
       || contains(github.event.pull_request.labels.*.name, 'Documentation')
-      || (github.event_name == 'push' && github.actor == 'dependabot[bot]')
+      || (github.event.pull_request.user.login == 'dependabot[bot]')
       )}}
 
     steps:
-      - uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4.1.1
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
         with:
           sparse-checkout-cone-mode: false
           sparse-checkout: /.github
+          persist-credentials: false
 
       - name: Install libraries
         uses: ./.github/actions/setup/macos
@@ -61,50 +79,111 @@ jobs:
           srcdir: src
           builddir: build
           makeup: true
+          clean: true
           dummy-files: ${{ matrix.test_task == 'check' }}
+          # Set fetch-depth: 0 so that Launchable can receive commits information.
+          fetch-depth: 10
+
+      - name: make sure that kern.coredump=1
+        run: |
+          sysctl -n kern.coredump
+          sudo sysctl -w kern.coredump=1
+          sudo chmod -R +rwx /cores/
+
+      - name: Delete unused SDKs
+        # To free up disk space to not run out during the run
+        run: |
+          sudo rm -rf ~/.dotnet
+          sudo rm -rf /Library/Android
+          sudo rm -rf /Library/Developer/CoreSimulator
+        continue-on-error: true
 
       - name: Run configure
-        run: ../src/configure -C --disable-install-doc ${{ matrix.configure }}
+        run: ../src/configure -C --disable-install-doc ${ruby_configure_args} ${{ matrix.configure_args }}
 
       - run: make prepare-gems
         if: ${{ matrix.test_task == 'test-bundled-gems' }}
 
       - run: make
 
+      - run: make hello
+
+      - name: runirb
+        run: |
+          echo IRB::VERSION | make runirb RUNOPT="-- -f"
+
+      - name: Set test options for skipped tests
+        run: |
+          set -x
+          TESTS="$(echo "${{ matrix.skipped_tests }}" | sed 's| |$$/ -n!/|g;s|^|-n!/|;s|$|$$/|')"
+          echo "TESTS=${TESTS}" >> $GITHUB_ENV
+        if: ${{ matrix.test_task == 'check' && matrix.skipped_tests }}
+
+      - name: Set up Launchable
+        id: launchable
+        uses: ./.github/actions/launchable/setup
+        with:
+          os: ${{ matrix.os }}
+          test-opts: ${{ matrix.test_opts }}
+          launchable-token: ${{ secrets.LAUNCHABLE_TOKEN }}
+          builddir: build
+          srcdir: src
+        continue-on-error: true
+        timeout-minutes: 3
+
+      - name: Set extra test options
+        run: |
+          echo "TESTS=$TESTS ${{ matrix.test_opts }}" >> $GITHUB_ENV
+          echo "RUBY_TEST_TIMEOUT_SCALE=10" >> $GITHUB_ENV # With --repeat-count=2, flaky test by timeout occurs frequently for some reason
+        if: matrix.test_opts
+
       - name: make ${{ matrix.test_task }}
         run: |
-          make -s ${{ matrix.test_task }} ${TESTS:+TESTS=`echo "$TESTS" | sed 's| |$$/ -n!/|g;s|^|-n!/|;s|$|$$/|'`}
-        timeout-minutes: 60
+          test -n "${LAUNCHABLE_STDOUT}" && exec 1> >(tee "${LAUNCHABLE_STDOUT}")
+          test -n "${LAUNCHABLE_STDERR}" && exec 2> >(tee "${LAUNCHABLE_STDERR}")
+
+          ulimit -c unlimited
+          make -s ${{ matrix.test_task }} ${TESTS:+TESTS="$TESTS"}
+        timeout-minutes: 90
         env:
           RUBY_TESTOPTS: '-q --tty=no'
-          TESTS: ${{ matrix.test_task == 'check' && matrix.skipped_tests || '' }}
           TEST_BUNDLED_GEMS_ALLOW_FAILURES: ''
           PRECHECK_BUNDLED_GEMS: 'no'
+          LAUNCHABLE_STDOUT: ${{ steps.launchable.outputs.stdout_report_path }}
+          LAUNCHABLE_STDERR: ${{ steps.launchable.outputs.stderr_report_path }}
 
       - name: make skipped tests
         run: |
-          make -s test-all TESTS=`echo "$TESTS" | sed 's| |$$/ -n/|g;s|^|-n/|;s|$|$$/|'`
+          make -s test-all TESTS="${TESTS//-n!\//-n/}"
         env:
           GNUMAKEFLAGS: ''
           RUBY_TESTOPTS: '-v --tty=no'
-          TESTS: ${{ matrix.skipped_tests }}
           PRECHECK_BUNDLED_GEMS: 'no'
-        if: ${{ matrix.test_task == 'check' && matrix.skipped_tests != '' }}
+        if: ${{ matrix.test_task == 'check' && matrix.skipped_tests }}
         continue-on-error: ${{ matrix.continue-on-skipped_tests || false }}
 
+      - name: CAPI extensions
+        uses: ./.github/actions/capiext
+        with:
+          builddir: build
+        env:
+          RUBY_TESTOPTS: '-v --tty=no'
+        if: ${{ contains(matrix.extra_checks, 'capi') }}
+
       - uses: ./.github/actions/slack
         with:
-          label: ${{ matrix.os }} / ${{ matrix.test_task }} ${{ matrix.configure }}
+          label: ${{ matrix.os }} / ${{ matrix.test_task }}
           SLACK_WEBHOOK_URL: ${{ secrets.SIMPLER_ALERTS_URL }} # ruby-lang slack: ruby/simpler-alerts-bot
         if: ${{ failure() }}
 
   result:
     if: ${{ always() }}
     name: ${{ github.workflow }} result
-    runs-on: macos-latest
+    runs-on: ubuntu-latest
     needs: [make]
     steps:
       - run: exit 1
+        working-directory:
         if: ${{ contains(needs.*.result, 'failure') || contains(needs.*.result, 'cancelled') }}
 
 defaults:
diff --git a/.github/workflows/mingw.yml b/.github/workflows/mingw.yml
index 41e7718d2e..9a47e70f8c 100644
--- a/.github/workflows/mingw.yml
+++ b/.github/workflows/mingw.yml
@@ -3,24 +3,20 @@ on:
   push:
     paths-ignore:
       - 'doc/**'
-      - '**/man'
+      - '**/man/*'
       - '**.md'
       - '**.rdoc'
       - '**/.document'
+      - '.*.yml'
   pull_request:
     paths-ignore:
       - 'doc/**'
-      - '**/man'
+      - '**/man/*'
       - '**.md'
       - '**.rdoc'
       - '**/.document'
+      - '.*.yml'
   merge_group:
-    paths-ignore:
-      - 'doc/**'
-      - '**/man'
-      - '**.md'
-      - '**.rdoc'
-      - '**/.document'
 
 concurrency:
   group: ${{ github.workflow }} / ${{ startsWith(github.event_name, 'pull') && github.ref_name || github.sha }}
@@ -34,16 +30,32 @@ permissions:
 #
 jobs:
   make:
-    runs-on: windows-2022
+    runs-on: windows-${{ matrix.os }}
 
     name: ${{ github.workflow }} (${{ matrix.msystem }})
 
     env:
       MSYSTEM: ${{ matrix.msystem }}
-      MSYS2_ARCH: x86_64
-      CHOST: 'x86_64-w64-mingw32'
-      CFLAGS: '-march=x86-64 -mtune=generic -O3 -pipe'
-      CXXFLAGS: '-march=x86-64 -mtune=generic -O3 -pipe'
+      MSYS2_ARCH: >-
+        ${{ case(
+        contains(matrix.msystem, 'arm64'), 'aarch64',
+        contains(matrix.msystem, '64'), 'x86_64',
+        'i686'
+        ) }}
+      MINGW_PACKAGE_PREFIX: >-
+        mingw-w${{
+        case(endsWith(matrix.msystem, '64'), '64', '32')
+        }}-${{ case(
+        startsWith(matrix.msystem, 'clang'), 'clang',
+        startsWith(matrix.msystem, 'ucrt'), 'ucrt',
+        'mingw'
+        ) }}-${{ case(
+        contains(matrix.msystem, 'arm64'), 'aarch64',
+        endsWith(matrix.msystem, '64'), 'x86_64',
+        'i686'
+        ) }}
+      CFLAGS: '-mtune=generic -O3 -pipe'
+      CXXFLAGS: '-mtune=generic -O3 -pipe'
       CPPFLAGS: '-D_FORTIFY_SOURCE=2 -D__USE_MINGW_ANSI_STDIO=1 -DFD_SETSIZE=2048'
       LDFLAGS: '-pipe'
       GITPULLOPTIONS: --no-tags origin ${{ github.ref }}
@@ -52,10 +64,14 @@ jobs:
       matrix:
         include:
           # To mitigate flakiness of MinGW CI, we test only one runtime that newer MSYS2 uses.
+          # Ruby 3.2 is the first Windows Ruby to use OpenSSL 3.x
           - msystem: 'UCRT64'
-            base_ruby: head
+            os: 2022
             test_task: 'check'
             test-all-opts: '--name=!/TestObjSpace#test_reachable_objects_during_iteration/'
+          - msystem: 'CLANGARM64'
+            os: 11-arm
+            test_task: 'check'
       fail-fast: false
 
     if: >-
@@ -63,68 +79,138 @@ jobs:
       || contains(github.event.head_commit.message, '[DOC]')
       || contains(github.event.pull_request.title, '[DOC]')
       || contains(github.event.pull_request.labels.*.name, 'Documentation')
-      || (github.event_name == 'push' && github.actor == 'dependabot[bot]')
+      || (github.event.pull_request.user.login == 'dependabot[bot]' && !startsWith(github.head_ref, 'dependabot/vcpkg'))
       )}}
 
     steps:
-      - name: Set up Ruby & MSYS2
-        uses: ruby/setup-ruby@a05e47355e80e57b9a67566a813648fa67d92011 # v1.157.0
+      - uses: msys2/setup-msys2@e9898307ac31d1a803454791be09ab9973336e1c # v2.31.1
+        id: msys2
         with:
-          ruby-version: ${{ matrix.base_ruby }}
-
-      - name: where check
-        run: |
-          # show where
-          mv /c/Windows/System32/libcrypto-1_1-x64.dll /c/Windows/System32/libcrypto-1_1-x64.dll_
-          mv /c/Windows/System32/libssl-1_1-x64.dll    /c/Windows/System32/libssl-1_1-x64.dll_
-          result=true
-          for e in gcc.exe ragel.exe make.exe libcrypto-1_1-x64.dll libssl-1_1-x64.dll; do
-            echo ::group::$'\033[93m'$e$'\033[m'
-            where $e || result=false
-            echo ::endgroup::
-          done
-          $result
+          msystem: ${{ matrix.msystem }}
+          update: true
+          install: >-
+            git
+            make
+            ruby
+            autoconf
+            ${{ env.MINGW_PACKAGE_PREFIX }}-gcc
+            ${{ env.MINGW_PACKAGE_PREFIX }}-ragel
+            ${{ env.MINGW_PACKAGE_PREFIX }}-openssl
+            ${{ env.MINGW_PACKAGE_PREFIX }}-libyaml
+            ${{ env.MINGW_PACKAGE_PREFIX }}-libffi
+
+      - name: Set up env
+        id: setup-env
         working-directory:
-
-      - name: version check
         run: |
-          # show version
-          result=true
-          for e in gcc ragel make "openssl version"; do
-            case "$e" in *" "*) ;; *) e="$e --version";; esac
-            echo ::group::$'\033[93m'$e$'\033[m'
-            $e || result=false
-            echo ::endgroup::
-          done
-          $result
+          $msys2 = ${env:MSYS2_LOCATION}
+          $msystem = ${env:MSYSTEM}.ToLower()
+          echo $msys2\usr\bin $msys2\$msystem\bin |
+            Tee-Object ${env:GITHUB_PATH} -Append -Encoding utf-8
+
+          # Use the fast device for the temporary directory.
+          # %TEMP% is inconsistent with %TMP% and test-all expects they are consistent.
+          # https://github.com/actions/virtual-environments/issues/712#issuecomment-613004302
+          $tmp = ${env:RUNNER_TEMP}
+          echo HOME=$home TMP=$tmp TEMP=$tmp TMPDIR=$tmp |
+            Tee-Object ${env:GITHUB_ENV} -Append -Encoding utf-8
+        shell: pwsh             # cmd.exe does not strip spaces before `|`.
+        env:
+          MSYS2_LOCATION: ${{ steps.msys2.outputs.msys2-location }}
+          MSYSTEM: ${{ matrix.msystem }}
+
+      - name: Remove Strawberry Perl pkg-config
         working-directory:
+        # `pkg-config.bat` included in Strawberry Perl is written in
+        # Perl and doesn't work when another msys2 `perl` precede its
+        # own `perl`.
+        #
+        # ```
+        # Can't find C:\Strawberry\perl\bin\pkg-config.bat on PATH, '.' not in PATH.
+        # ```
+        run: |
+          Get-Command pkg-config.bat | % { ren $_.path ($_.path + "~") }
+        shell: pwsh
 
-      - uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4.1.1
+      - name: Misc system & package info
+        working-directory:
+        run: |
+          group() { echo ::group::$'\e[94;1m'"$*"$'\e[m'; }
+          endgroup() { echo ::endgroup::; }
+
+          group Path
+          cygpath -wa / . $(type -p cygpath bash sh)
+          endgroup
+
+          I() {
+              group $1
+              run Where type -pa $1 && { [ $# -eq 1 ] || run Version "$@"; } ||
+                  failed+=($1)
+              endgroup
+          }
+          run() { local w m=$1; shift; w="$("$@")" && show "$m" && indent "$w"; }
+          indent() { [ -z "$1" ] || echo "$1" | /bin/sed '/^$/!s/^/  /'; }
+          show() { echo $'\e[96m'"$*"$'\e[m'; }
+
+          failed=()
+
+          I gcc.exe --version
+          I ragel.exe --version
+          I make.exe --version
+          I openssl.exe version
+          I libcrypto-3-x64.dll
+          I libssl-3-x64.dll
+
+          group Packages
+          pacman -Qs $MINGW_PACKAGE_PREFIX-* | /bin/sed -n "s,local/$MINGW_PACKAGE_PREFIX-,,p"
+          endgroup
+
+          [ ${#failed[@]} -eq 0 ]
+        shell: sh
+
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
         with:
           sparse-checkout-cone-mode: false
           sparse-checkout: /.github
+          persist-credentials: false
 
       - uses: ./.github/actions/setup/directories
         with:
           srcdir: src
           builddir: build
           makeup: true
+          # Set fetch-depth: 10 so that Launchable can receive commits information.
+          fetch-depth: 10
 
       - name: configure
         run: >
           ../src/configure --disable-install-doc --prefix=/.
           --build=$CHOST --host=$CHOST --target=$CHOST
+        shell: sh
+        env:
+          CHOST: ${{ env.MSYS2_ARCH }}-w64-mingw32
 
       - name: make all
         timeout-minutes: 30
-        run: make
+        run: make -j4
 
       - name: make install
         run: make DESTDIR=../install install-nodoc
 
+      - name: Set up Launchable
+        uses: ./.github/actions/launchable/setup
+        with:
+          os: windows-2022
+          launchable-token: ${{ secrets.LAUNCHABLE_TOKEN }}
+          builddir: build
+          srcdir: src
+          test-tasks: '["test", "test-all", "test-spec"]'
+        continue-on-error: true
+        timeout-minutes: 3
+
       - name: test
         timeout-minutes: 30
-        run: make test
+        run: make test test-tool
         env:
           GNUMAKEFLAGS: ''
           RUBY_TESTOPTS: '-v --tty=no'
@@ -133,13 +219,12 @@ jobs:
       - name: test-all
         timeout-minutes: 45
         run: |
-          # Actions uses UTF8, causes test failures, similar to normal OS setup
-          chcp.com 437
           make ${{ StartsWith(matrix.test_task, 'test/') && matrix.test_task || 'test-all' }}
         env:
           RUBY_TESTOPTS: >-
-            --retry --job-status=normal --show-skip --timeout-scale=1.5
+            --retry --job-status=normal --show-skip --timeout-scale=1.5 -j4
             ${{ matrix.test-all-opts }}
+            ${{ env.TESTS }}
           BUNDLER_VERSION:
         if: ${{ matrix.test_task == 'check' || matrix.test_task == 'test-all' || StartsWith(matrix.test_task, 'test/') }}
 
@@ -158,4 +243,4 @@ jobs:
 defaults:
   run:
     working-directory: build
-    shell: sh
+    shell: cmd
diff --git a/.github/workflows/modgc.yml b/.github/workflows/modgc.yml
new file mode 100644
index 0000000000..218127aad7
--- /dev/null
+++ b/.github/workflows/modgc.yml
@@ -0,0 +1,179 @@
+name: ModGC
+on:
+  push:
+    paths-ignore:
+      - 'doc/**'
+      - '**/man/*'
+      - '**.md'
+      - '**.rdoc'
+      - '**/.document'
+      - '.*.yml'
+  pull_request:
+    # Do not use paths-ignore for required status checks
+    # https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/collaborating-on-repositories-with-code-quality-features/troubleshooting-required-status-checks#handling-skipped-but-required-checks
+  merge_group:
+
+concurrency:
+  group: ${{ github.workflow }} / ${{ startsWith(github.event_name, 'pull') && github.ref_name || github.sha }}
+  cancel-in-progress: ${{ startsWith(github.event_name, 'pull') }}
+
+permissions:
+  contents: read
+
+jobs:
+  check:
+    strategy:
+      matrix:
+        gc:
+          - name: default
+          - name: mmtk
+            mmtk_build: release
+        os: [macos-26, ubuntu-latest]
+        include:
+          - test_task: check
+      fail-fast: false
+
+    env:
+      GITPULLOPTIONS: --no-tags origin ${{ github.ref }}
+      RUBY_DEBUG: ci
+
+    runs-on: ${{ matrix.os }}
+
+    if: >-
+      ${{!(false
+      || contains(github.event.head_commit.message, '[DOC]')
+      || contains(github.event.pull_request.title, '[DOC]')
+      || contains(github.event.pull_request.labels.*.name, 'Documentation')
+      || (github.event.pull_request.user.login == 'dependabot[bot]')
+      )}}
+
+    steps:
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with:
+          sparse-checkout-cone-mode: false
+          sparse-checkout: /.github
+          persist-credentials: false
+
+      - name: Install libraries (macOS)
+        uses: ./.github/actions/setup/macos
+        if: ${{ contains(matrix.os, 'macos') }}
+
+      - name: Install libraries (Ubuntu)
+        uses: ./.github/actions/setup/ubuntu
+        if: ${{ contains(matrix.os, 'ubuntu') }}
+
+      - uses: ruby/setup-ruby@afeafc3d1ab54a631816aba4c914a0081c12ff2f # v1.310.0
+        with:
+          ruby-version: '3.1'
+          bundler: none
+        if: ${{ contains(matrix.os, 'ubuntu') }}
+
+      - uses: ./.github/actions/setup/directories
+        with:
+          srcdir: src
+          builddir: build
+          makeup: true
+          clean: true
+          dummy-files: false
+          # Set fetch-depth: 10 so that Launchable can receive commits information.
+          fetch-depth: 10
+
+      - name: make sure that kern.coredump=1
+        run: |
+          sysctl -n kern.coredump
+          sudo sysctl -w kern.coredump=1
+          sudo chmod -R +rwx /cores/
+        if: ${{ contains(matrix.os, 'macos') }}
+
+      - name: Delete unused SDKs
+        # To free up disk space to not run out during the run
+        run: |
+          sudo rm -rf ~/.dotnet
+          sudo rm -rf /Library/Android
+          sudo rm -rf /Library/Developer/CoreSimulator
+        continue-on-error: true
+        if: ${{ contains(matrix.os, 'macos') }}
+
+      - name: Setup Ruby GC Directory
+        run: |
+          echo "MODULAR_GC_DIR=$HOME/ruby_gc" >> $GITHUB_ENV
+
+      - name: Run configure
+        env:
+          arch: ${{ matrix.arch }}
+        run: |
+          ${SETARCH} ../src/configure -C --disable-install-doc --with-modular-gc="${MODULAR_GC_DIR}" \
+          ${arch:+--target=$arch-$OSTYPE --host=$arch-$OSTYPE}
+
+      - uses: actions-rust-lang/setup-rust-toolchain@46268bd060767258de96ed93c1251119784f2ab6 # v1.16.1
+        with:
+          cache-bin: false
+      - name: Set MMTk environment variables
+        run: |
+          echo 'EXCLUDES=../src/test/.excludes-mmtk' >> $GITHUB_ENV
+          echo 'MSPECOPT=-B../src/spec/mmtk.mspec' >> $GITHUB_ENV
+        if: ${{ matrix.gc.name == 'mmtk' }}
+
+      - run: ${SETARCH} make
+
+      - name: Build Modular  GC
+        run: |
+          echo "RUBY_GC_LIBRARY=${{ matrix.gc.name }}" >> $GITHUB_ENV
+          make install-modular-gc MODULAR_GC=${{ matrix.gc.name }} MMTK_BUILD=${{ matrix.gc.mmtk_build }}
+          make distclean-modular-gc MODULAR_GC=${{ matrix.gc.name }}
+
+      - run: ${SETARCH} make hello
+
+      - name: Set test options for skipped tests
+        run: |
+          set -x
+          TESTS="$(echo "${{ matrix.skipped_tests }}" | sed 's| |$$/ -n!/|g;s|^|-n!/|;s|$|$$/|')"
+          echo "TESTS=${TESTS}" >> $GITHUB_ENV
+        if: ${{ matrix.test_task == 'check' && matrix.skipped_tests }}
+
+      - name: Set up Launchable
+        id: launchable
+        uses: ./.github/actions/launchable/setup
+        with:
+          os: ${{ matrix.os || 'ubuntu-22.04' }}
+          test-opts: ${{ matrix.configure }}
+          launchable-token: ${{ secrets.LAUNCHABLE_TOKEN }}
+          builddir: build
+          srcdir: src
+        continue-on-error: true
+        timeout-minutes: 3
+
+      - name: make ${{ matrix.test_task }}
+        run: |
+          test -n "${LAUNCHABLE_STDOUT}" && exec 1> >(tee "${LAUNCHABLE_STDOUT}")
+          test -n "${LAUNCHABLE_STDERR}" && exec 2> >(tee "${LAUNCHABLE_STDERR}")
+
+          ${SETARCH} make -s ${{ matrix.test_task }} \
+            ${TESTS:+TESTS="$TESTS"} \
+            ${{ !contains(matrix.test_task, 'bundle') && 'RUBYOPT=-w' || '' }}
+        timeout-minutes: ${{ matrix.gc.timeout || 40 }}
+        env:
+          RUBY_TESTOPTS: '-q --tty=no'
+          TEST_BUNDLED_GEMS_ALLOW_FAILURES: ''
+          PRECHECK_BUNDLED_GEMS: 'no'
+          LAUNCHABLE_STDOUT: ${{ steps.launchable.outputs.stdout_report_path }}
+          LAUNCHABLE_STDERR: ${{ steps.launchable.outputs.stderr_report_path }}
+
+      - name: make skipped tests
+        run: |
+          ${SETARCH} make -s test-all TESTS="${TESTS//-n!\//-n/}"
+        env:
+          GNUMAKEFLAGS: ''
+          RUBY_TESTOPTS: '-v --tty=no'
+        if: ${{ matrix.test_task == 'check' && matrix.skipped_tests }}
+        continue-on-error: ${{ matrix.continue-on-skipped_tests || false }}
+
+      - uses: ./.github/actions/slack
+        with:
+          label: ${{ matrix.test_task }} ${{ matrix.configure }}${{ matrix.arch }}
+          SLACK_WEBHOOK_URL: ${{ secrets.SIMPLER_ALERTS_URL }} # ruby-lang slack: ruby/simpler-alerts-bot
+        if: ${{ failure() }}
+
+defaults:
+  run:
+    working-directory: build
diff --git a/.github/workflows/parse_y.yml b/.github/workflows/parse_y.yml
new file mode 100644
index 0000000000..7c26e87e57
--- /dev/null
+++ b/.github/workflows/parse_y.yml
@@ -0,0 +1,101 @@
+name: parse.y
+on:
+  push:
+    paths-ignore:
+      - 'doc/**'
+      - '**/man/*'
+      - '**.md'
+      - '**.rdoc'
+      - '**/.document'
+      - '.*.yml'
+  pull_request:
+    paths-ignore:
+      - 'doc/**'
+      - '**/man/*'
+      - '**.md'
+      - '**.rdoc'
+      - '**/.document'
+      - '.*.yml'
+  merge_group:
+
+concurrency:
+  group: ${{ github.workflow }} / ${{ startsWith(github.event_name, 'pull') && github.ref_name || github.sha }}
+  cancel-in-progress: ${{ startsWith(github.event_name, 'pull') }}
+
+permissions:
+  contents: read
+
+jobs:
+  make:
+    strategy:
+      matrix:
+        include:
+          - test_task: check
+          - test_task: test-bundler-parallel
+          - test_task: test-bundled-gems
+      fail-fast: false
+
+    env:
+      GITPULLOPTIONS: --no-tags origin ${{ github.ref }}
+      RUBY_DEBUG: ci
+      SETARCH: ${{ matrix.arch && format('setarch {0}', matrix.arch) }}
+
+    runs-on: ubuntu-22.04
+
+    if: >-
+      ${{!(false
+      || contains(github.event.head_commit.message, '[DOC]')
+      || contains(github.event.pull_request.title, '[DOC]')
+      || contains(github.event.pull_request.labels.*.name, 'Documentation')
+      || (github.event.pull_request.user.login == 'dependabot[bot]')
+      )}}
+
+    steps:
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with:
+          sparse-checkout-cone-mode: false
+          sparse-checkout: /.github
+          persist-credentials: false
+
+      - uses: ./.github/actions/setup/ubuntu
+
+      - uses: ruby/setup-ruby@afeafc3d1ab54a631816aba4c914a0081c12ff2f # v1.310.0
+        with:
+          ruby-version: '3.1'
+          bundler: none
+
+      - uses: ./.github/actions/setup/directories
+        with:
+          srcdir: src
+          builddir: build
+          makeup: true
+          clean: true
+          dummy-files: ${{ matrix.test_task == 'check' }}
+
+      - name: Run configure
+        run: ../src/configure -C --disable-install-doc cppflags=-DRUBY_DEBUG --with-parser=parse.y
+
+      - run: make
+
+      - run: make TESTRUN_SCRIPT='-renvutil -v -e "exit EnvUtil.current_parser == %[parse.y]"' run
+        env:
+          RUNOPT0: -I$(tooldir)/lib
+
+      - name: make ${{ matrix.test_task }}
+        run: make -s ${{ matrix.test_task }} RUN_OPTS="$RUN_OPTS" SPECOPTS="$SPECOPTS"
+        env:
+          RUBY_TESTOPTS: ${{ matrix.testopts }}
+          EXCLUDES: '../src/test/.excludes-parsey'
+          RUN_OPTS: ${{ matrix.run_opts || '--parser=parse.y' }}
+          SPECOPTS: ${{ matrix.specopts || '-T --parser=parse.y' }}
+          TEST_BUNDLED_GEMS_ALLOW_FAILURES: ''
+
+      - uses: ./.github/actions/slack
+        with:
+          label: ${{ matrix.run_opts }}
+          SLACK_WEBHOOK_URL: ${{ secrets.SIMPLER_ALERTS_URL }} # ruby-lang slack: ruby/simpler-alerts-bot
+        if: ${{ failure() }}
+
+defaults:
+  run:
+    working-directory: build
diff --git a/.github/workflows/post_push.yml b/.github/workflows/post_push.yml
new file mode 100644
index 0000000000..e351c8c286
--- /dev/null
+++ b/.github/workflows/post_push.yml
@@ -0,0 +1,97 @@
+name: Post-push
+on:
+  push:
+    branches:
+      - master
+      - 'ruby_*_*'
+
+permissions:
+  contents: read
+
+jobs:
+  hooks:
+    name: Post-push hooks
+    runs-on: ubuntu-latest
+    if: ${{ github.repository == 'ruby/ruby' }}
+    steps:
+      - name: Sync git.ruby-lang.org
+        id: sync-git
+        continue-on-error: true
+        run: |
+          mkdir -p ~/.ssh
+          (umask 066; printenv RUBY_GIT_SYNC_PRIVATE_KEY > ~/.ssh/id_ed25519)
+          ssh-keyscan -t ed25519 git.ruby-lang.org >> ~/.ssh/known_hosts
+          ssh -i ~/.ssh/id_ed25519 git-sync@git.ruby-lang.org "sudo -u git /home/git/git.ruby-lang.org/bin/update-ruby.sh $GITHUB_REF"
+        env:
+          GITHUB_REF: ${{ github.ref }}
+          RUBY_GIT_SYNC_PRIVATE_KEY: ${{ secrets.RUBY_GIT_SYNC_PRIVATE_KEY }}
+        if: ${{ github.ref == 'refs/heads/master' || startsWith(github.ref, 'refs/heads/ruby_') }}
+
+      - name: Fetch changesets on bugs.ruby-lang.org
+        run: |
+          curl "https://bugs.ruby-lang.org/sys/fetch_changesets?key=${REDMINE_SYS_API_KEY}" -s --fail-with-body -w '* status: %{http_code}\n'
+        env:
+          REDMINE_SYS_API_KEY: ${{ secrets.REDMINE_SYS_API_KEY }}
+        if: ${{ github.ref == 'refs/heads/master' || startsWith(github.ref, 'refs/heads/ruby_') }}
+
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with:
+          fetch-depth: 500 # for notify-slack-commits
+          token: ${{ secrets.MATZBOT_AUTO_UPDATE_TOKEN }}
+
+      - name: Notify commit to Slack
+        run: ruby tool/notify-slack-commits.rb "$GITHUB_OLD_SHA" "$GITHUB_NEW_SHA" refs/heads/master
+        env:
+          GITHUB_OLD_SHA: ${{ github.event.before }}
+          GITHUB_NEW_SHA: ${{ github.event.after }}
+          SLACK_WEBHOOK_URL_ALERTS: ${{ secrets.SLACK_WEBHOOK_URL_ALERTS }}
+          SLACK_WEBHOOK_URL_COMMITS: ${{ secrets.SLACK_WEBHOOK_URL_COMMITS }}
+          SLACK_WEBHOOK_URL_RUBY_JP: ${{ secrets.SLACK_WEBHOOK_URL_RUBY_JP }}
+        if: ${{ github.ref == 'refs/heads/master' }}
+
+      - name: Notify commit to ruby-cvs
+        run: |
+          SENDMAIL="ssh -i ${HOME}/.ssh/id_ed25519 git-sync@git.ruby-lang.org /usr/sbin/sendmail" \
+            ruby tool/commit-email.rb . ruby-cvs@g.ruby-lang.org \
+            "$GITHUB_OLD_SHA" "$GITHUB_NEW_SHA" "$GITHUB_REF" \
+            --viewer-uri "https://github.com/ruby/ruby/commit/" \
+            --error-to cvs-admin@ruby-lang.org
+        env:
+          GITHUB_OLD_SHA: ${{ github.event.before }}
+          GITHUB_NEW_SHA: ${{ github.event.after }}
+          GITHUB_REF: ${{ github.ref }}
+        if: ${{ github.ref == 'refs/heads/master' || startsWith(github.ref, 'refs/heads/ruby_') }}
+
+      - name: Auto-correct code styles
+        run: |
+          set -x
+          ruby tool/auto-style.rb "$GITHUB_OLD_SHA" "$GITHUB_NEW_SHA" refs/heads/master
+        env:
+          GITHUB_OLD_SHA: ${{ github.event.before }}
+          GITHUB_NEW_SHA: ${{ github.event.after }}
+          GIT_AUTHOR_NAME: git
+          GIT_COMMITTER_NAME: git
+          EMAIL: svn-admin@ruby-lang.org
+        if: ${{ github.ref == 'refs/heads/master' }}
+
+      - name: Push PR notes to GitHub
+        id: pr-notes
+        continue-on-error: true
+        run: ruby tool/notes-github-pr.rb "$(pwd)/.git" "$GITHUB_OLD_SHA" "$GITHUB_NEW_SHA" refs/heads/master
+        env:
+          GITHUB_OLD_SHA: ${{ github.event.before }}
+          GITHUB_NEW_SHA: ${{ github.event.after }}
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          GIT_AUTHOR_NAME: git
+          GIT_COMMITTER_NAME: git
+          EMAIL: svn-admin@ruby-lang.org
+        if: ${{ github.ref == 'refs/heads/master' }}
+
+      - name: Check for failures
+        run: exit 1
+        if: ${{ steps.sync-git.outcome == 'failure' || steps.pr-notes.outcome == 'failure' }}
+
+      - uses: ./.github/actions/slack
+        with:
+          SLACK_WEBHOOK_URL: ${{ secrets.SIMPLER_ALERTS_URL }} # ruby-lang slack: ruby/simpler-alerts-bot
+        if: ${{ failure() }}
diff --git a/.github/workflows/pr-playground.yml b/.github/workflows/pr-playground.yml
new file mode 100644
index 0000000000..dc4f075a38
--- /dev/null
+++ b/.github/workflows/pr-playground.yml
@@ -0,0 +1,131 @@
+name: Post Playground link to PR
+on:
+  pull_request_target:
+    types: [labeled]
+  workflow_run:
+    workflows: ["WebAssembly"]
+    types: [completed]
+
+permissions:
+  contents: read
+  actions: read
+
+jobs:
+  post-summary:
+    name: Post Playground link
+    runs-on: ubuntu-latest
+    permissions:
+      pull-requests: write
+    # Post a comment only if the PR status check is passed and the PR is labeled with `Playground`.
+    # Triggered twice: when the PR is labeled and when PR build is passed.
+    if: >-
+      ${{ false
+      || (true
+        && github.event_name == 'pull_request_target'
+        && contains(github.event.pull_request.labels.*.name, 'Playground'))
+      || (true
+        && github.event_name == 'workflow_run'
+        && github.event.workflow_run.conclusion == 'success'
+        && github.event.workflow_run.event == 'pull_request')
+      }}
+    steps:
+      - uses: actions/github-script@3a2844b7e9c422d3c10d287c895573f7108da1b3 # v9.0.0
+        with:
+          github-token: ${{ secrets.GITHUB_TOKEN }}
+          script: |
+            const fs = require('fs/promises');
+
+            const buildWorkflowPath = '.github/workflows/wasm.yml';
+            const findSuccessfuBuildRun = async (pr) => {
+              const opts = github.rest.actions.listWorkflowRunsForRepo.endpoint.merge({
+                owner: context.repo.owner,
+                repo: context.repo.repo,
+                status: 'success',
+                branch: pr.head.ref,
+              });
+              const runs = await github.paginate(opts);
+              const buildRun = runs.find(run => run.path == buildWorkflowPath);
+              return buildRun;
+            }
+
+            const postComment = async (body, pr) => {
+              const { data: comments } = await github.rest.issues.listComments({
+                owner: context.repo.owner,
+                repo: context.repo.repo,
+                issue_number: pr.number,
+              });
+
+              const commentOpts = { owner: context.repo.owner, repo: context.repo.repo, body: comment };
+
+              const existingComment = comments.find(comment => comment.body.startsWith(magicComment));
+              if (existingComment) {
+                core.info(`Updating existing comment: ${existingComment.html_url}`);
+                await github.rest.issues.updateComment({
+                  ...commentOpts, comment_id: existingComment.id
+                });
+              } else {
+                await github.rest.issues.createComment({
+                  ...commentOpts, issue_number: pr.number
+                });
+              }
+            }
+
+            const derivePRNumber = async () => {
+              if (context.payload.pull_request) {
+                return context.payload.pull_request.number;
+              }
+              // Workaround for https://github.com/orgs/community/discussions/25220
+
+              const { data: { artifacts } } = await github.rest.actions.listWorkflowRunArtifacts({
+                owner: context.repo.owner,
+                repo: context.repo.repo,
+                run_id: context.payload.workflow_run.id,
+              });
+              const artifact = artifacts.find(artifact => artifact.name == 'github-pr-info');
+              if (!artifact) {
+                throw new Error('Cannot find github-pr-info.txt artifact');
+              }
+
+              const { data } = await github.rest.actions.downloadArtifact({
+                owner: context.repo.owner,
+                repo: context.repo.repo,
+                artifact_id: artifact.id,
+                archive_format: 'zip',
+              });
+
+              await fs.writeFile('pr-info.zip', Buffer.from(data));
+              await exec.exec('unzip', ['pr-info.zip']);
+              return await fs.readFile('github-pr-info.txt', 'utf8');
+            }
+
+            const prNumber = await derivePRNumber();
+
+            const { data: pr } = await github.rest.pulls.get({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              pull_number: prNumber,
+            });
+
+            core.info(`Checking if the PR ${prNumber} is labeled with Playground...`);
+            if (!pr.labels.some(label => label.name == 'Playground')) {
+              core.info(`The PR is not labeled with Playground.`);
+              return;
+            }
+
+            core.info(`Checking if the build is successful for ${pr.head.ref} in ${pr.head.repo.owner.login}/${pr.head.repo.name}...`);
+            const buildRun = await findSuccessfuBuildRun(pr);
+            if (!buildRun) {
+              core.info(`No successful build run found for ${buildWorkflowPath} on ${pr.head.ref} yet.`);
+              return;
+            }
+            core.info(`Found a successful build run: ${buildRun.html_url}`);
+
+            const runLink = `${process.env.GITHUB_SERVER_URL}/${process.env.GITHUB_REPOSITORY}/actions/runs/${process.env.GITHUB_RUN_ID}`;
+            const magicComment = `<!-- AUTO-GENERATED-COMMENT-PR-PLAYGROUND -->`;
+            const comment = `${magicComment}
+            **Try on Playground**: https://ruby.github.io/play-ruby?run=${buildRun.id}
+            This is an automated comment by [\`pr-playground.yml\`](${runLink}) workflow.
+            `;
+            core.info(`Comment: ${comment}`);
+            await postComment(comment, pr);
+
diff --git a/.github/workflows/publish.yml b/.github/workflows/publish.yml
new file mode 100644
index 0000000000..5d4a31d287
--- /dev/null
+++ b/.github/workflows/publish.yml
@@ -0,0 +1,114 @@
+name: Publish Ruby packages
+
+on:
+  repository_dispatch:
+    types:
+      - release
+  workflow_dispatch:
+    inputs:
+      version:
+        description: 'Version of the Ruby package to release'
+        required: true
+        default: '4.0.0'
+
+permissions:
+  contents: read
+
+jobs:
+  release:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with:
+          persist-credentials: false
+
+      - uses: ruby/setup-ruby@afeafc3d1ab54a631816aba4c914a0081c12ff2f # v1.310.0
+        with:
+          ruby-version: 3.3.4
+
+      - name: Store Ruby version
+        env:
+          RUBY_VERSION: ${{ github.event.client_payload.version || github.event.inputs.version }}
+        run: |
+          echo "RUBY_VERSION=${RUBY_VERSION}" >> $GITHUB_ENV
+
+      - name: Store ABI version
+        run: echo "ABI_VERSION=$(echo ${RUBY_VERSION} | cut -d '.' -f 1-2)" >> $GITHUB_ENV
+
+      - name: Copy draft package `/tmp` to `/pub` directory
+        run: tool/release.sh ${RUBY_VERSION}
+        env:
+          AWS_ACCESS_KEY_ID: ${{ secrets.FTP_R_L_O_AWS_ACCESS_KEY_ID }}
+          AWS_SECRET_ACCESS_KEY: ${{ secrets.FTP_R_L_O_AWS_SECRET_ACCESS_KEY }}
+          AWS_DEFAULT_REGION: us-west-2
+
+      - name: Purge URLs of release package
+        run: |
+          curl -X POST \
+            -H "Fastly-Key: ${{ secrets.FASTLY_PURGE_TOKEN }}" \
+            https://api.fastly.com/purge/cache.ruby-lang.org/pub/ruby/${ABI_VERSION}/ruby-${RUBY_VERSION}.tar.gz
+          curl -X POST \
+            -H "Fastly-Key: ${{ secrets.FASTLY_PURGE_TOKEN }}" \
+            https://api.fastly.com/purge/cache.ruby-lang.org/pub/ruby/${ABI_VERSION}/ruby-${RUBY_VERSION}.tar.xz
+          curl -X POST \
+            -H "Fastly-Key: ${{ secrets.FASTLY_PURGE_TOKEN }}" \
+            https://api.fastly.com/purge/cache.ruby-lang.org/pub/ruby/${ABI_VERSION}/ruby-${RUBY_VERSION}.zip
+
+      - name: Create a release on GitHub
+        run: |
+          RELEASE_TAG=$(ruby tool/ruby-version.rb tag "${RUBY_VERSION}")
+          echo $RELEASE_TAG
+          PREVIOUS_RELEASE_TAG=$(ruby tool/ruby-version.rb previous-tag "${RUBY_VERSION}")
+          echo $PREVIOUS_RELEASE_TAG
+          tool/gen-github-release.rb $PREVIOUS_RELEASE_TAG $RELEASE_TAG --no-dry-run
+        env:
+          GITHUB_TOKEN: ${{ secrets.MATZBOT_AUTO_UPDATE_TOKEN }}
+
+      - name: Update versions index
+        run: |
+          curl -L -X POST \
+            -H "Authorization: Bearer ${{ secrets.MATZBOT_GITHUB_WORKFLOW_TOKEN }}" \
+            -H "Accept: application/vnd.github+json" \
+            -H "X-GitHub-Api-Version: 2022-11-28" \
+            https://api.github.com/repos/ruby/actions/dispatches \
+            -d '{"event_type": "update_index"}'
+
+      - name: Build and push Docker images
+        run: |
+          curl -L -X POST \
+            -H "Authorization: Bearer ${{ secrets.MATZBOT_GITHUB_WORKFLOW_TOKEN }}" \
+            -H "Accept: application/vnd.github+json" \
+            -H "X-GitHub-Api-Version: 2022-11-28" \
+            https://api.github.com/repos/ruby/docker-images/dispatches \
+            -d "{\"event_type\": \"build\", \"client_payload\": {\"ruby_version\": \"${RUBY_VERSION}\"}}"
+
+      - name: Build snapcraft packages
+        run: |
+          curl -L -X POST \
+            -H "Authorization: Bearer ${{ secrets.MATZBOT_GITHUB_WORKFLOW_TOKEN }}" \
+            -H "Accept: application/vnd.github+json" \
+            -H "X-GitHub-Api-Version: 2022-11-28" \
+            https://api.github.com/repos/ruby/snap.ruby/dispatches \
+            -d "{\"event_type\": \"build\", \"client_payload\": {\"ruby_version\": \"${RUBY_VERSION}\"}}"
+
+      - name: Store the latest LTS version of OpenSSL
+        run: |
+          echo "OPENSSL_VERSION=`curl -s https://api.github.com/repos/openssl/openssl/releases | jq -r '.[].tag_name | select(startswith("openssl-3.0"))' | sort -Vr | head -n1 | cut -d'-' -f2`" >> $GITHUB_ENV
+
+      - name: Update ruby-build definition
+        run: |
+          curl -L -X POST \
+            -H "Authorization: Bearer ${{ secrets.RUBY_BUILD_WORKFLOW_TOKEN }}" \
+            -H "Accept: application/vnd.github+json" \
+            -H "X-GitHub-Api-Version: 2022-11-28" \
+            https://api.github.com/repos/rbenv/ruby-build/dispatches \
+            -d "{\"event_type\": \"update-ruby\", \"client_payload\": {\"ruby_version\": \"${RUBY_VERSION}\", \"openssl_version\": \"${OPENSSL_VERSION}\"}}"
+
+      - name: Update all-ruby definition
+        run: |
+          curl -L -X POST \
+            -H "Authorization: Bearer ${{ secrets.MATZBOT_GITHUB_WORKFLOW_TOKEN }}" \
+            -H "Accept: application/vnd.github+json" \
+            -H "X-GitHub-Api-Version: 2022-11-28" \
+            https://api.github.com/repos/ruby/all-ruby/dispatches \
+            -d '{"event_type": "update"}'
diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
new file mode 100644
index 0000000000..a35bcff99a
--- /dev/null
+++ b/.github/workflows/release.yml
@@ -0,0 +1,21 @@
+name: Start release workflow
+on:
+  push:
+    tags:
+      - '*'
+
+permissions:
+  contents: read
+
+jobs:
+  notify:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Build release package
+        run: |
+          curl -L -X POST \
+            -H "Authorization: Bearer ${{ secrets.MATZBOT_GITHUB_WORKFLOW_TOKEN }}" \
+            -H "Accept: application/vnd.github+json" \
+            -H "X-GitHub-Api-Version: 2022-11-28" \
+            https://api.github.com/repos/ruby/actions/dispatches \
+            -d "{\"event_type\": \"$GITHUB_REF\"}"
diff --git a/.github/workflows/rjit-bindgen.yml b/.github/workflows/rjit-bindgen.yml
deleted file mode 100644
index 4c4e9b4899..0000000000
--- a/.github/workflows/rjit-bindgen.yml
+++ /dev/null
@@ -1,88 +0,0 @@
-name: RJIT bindgen
-on:
-  push:
-    paths-ignore:
-      - 'doc/**'
-      - '**/man'
-      - '**.md'
-      - '**.rdoc'
-      - '**/.document'
-  pull_request:
-    paths-ignore:
-      - 'doc/**'
-      - '**/man'
-      - '**.md'
-      - '**.rdoc'
-      - '**/.document'
-  merge_group:
-    paths-ignore:
-      - 'doc/**'
-      - '**/man'
-      - '**.md'
-      - '**.rdoc'
-      - '**/.document'
-
-concurrency:
-  group: ${{ github.workflow }} / ${{ startsWith(github.event_name, 'pull') && github.ref_name || github.sha }}
-  cancel-in-progress: ${{ startsWith(github.event_name, 'pull') }}
-
-permissions:
-  contents: read
-
-jobs:
-  make:
-    strategy:
-      matrix:
-        include:
-          - task: rjit-bindgen
-      fail-fast: false
-
-    runs-on: ubuntu-20.04
-
-    if: >-
-      ${{!(false
-      || contains(github.event.head_commit.message, '[DOC]')
-      || contains(github.event.pull_request.title, '[DOC]')
-      || contains(github.event.pull_request.labels.*.name, 'Documentation')
-      || (github.event_name == 'push' && github.actor == 'dependabot[bot]')
-      )}}
-
-    steps:
-      - name: Set up Ruby
-        uses: ruby/setup-ruby@a05e47355e80e57b9a67566a813648fa67d92011 # v1.157.0
-        with:
-          ruby-version: '3.1'
-
-      - uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4.1.1
-        with:
-          sparse-checkout-cone-mode: false
-          sparse-checkout: /.github
-
-      - uses: ./.github/actions/setup/ubuntu
-
-      - uses: ./.github/actions/setup/directories
-        with:
-          srcdir: src
-          builddir: build
-          makeup: true
-
-      - name: Run configure
-        run: ../src/configure -C --disable-install-doc --prefix=$(pwd)/install --enable-yjit=dev_nodebug
-
-      - run: make
-
-      - run: make install
-
-      - run: make ${{ matrix.task }}
-
-      - run: git diff --exit-code
-        working-directory: src
-
-      - uses: ./.github/actions/slack
-        with:
-          SLACK_WEBHOOK_URL: ${{ secrets.SIMPLER_ALERTS_URL }} # ruby-lang slack: ruby/simpler-alerts-bot
-        if: ${{ failure() }}
-
-defaults:
-  run:
-    working-directory: build
diff --git a/.github/workflows/rjit.yml b/.github/workflows/rjit.yml
deleted file mode 100644
index 53c29959eb..0000000000
--- a/.github/workflows/rjit.yml
+++ /dev/null
@@ -1,117 +0,0 @@
-name: RJIT
-on:
-  push:
-    paths-ignore:
-      - 'doc/**'
-      - '**.md'
-      - '**.rdoc'
-      - '**/.document'
-      - '**.[1-8]'
-      - '**.ronn'
-  pull_request:
-    paths-ignore:
-      - 'doc/**'
-      - '**.md'
-      - '**.rdoc'
-      - '**/.document'
-      - '**.[1-8]'
-      - '**.ronn'
-  merge_group:
-    paths-ignore:
-      - 'doc/**'
-      - '**.md'
-      - '**.rdoc'
-      - '**/.document'
-      - '**.[1-8]'
-      - '**.ronn'
-
-concurrency:
-  group: ${{ github.workflow }} / ${{ startsWith(github.event_name, 'pull') && github.ref_name || github.sha }}
-  cancel-in-progress: ${{ startsWith(github.event_name, 'pull') }}
-
-permissions:
-  contents: read
-
-jobs:
-  make:
-    strategy:
-      matrix:
-        # main variables included in the job name
-        test_task: [check]
-        run_opts: ['--rjit-call-threshold=1']
-        arch: ['']
-      fail-fast: false
-
-    env:
-      GITPULLOPTIONS: --no-tags origin ${{ github.ref }}
-      RUBY_DEBUG: ci
-      SETARCH: ${{ matrix.arch && format('setarch {0}', matrix.arch) }}
-
-    runs-on: ubuntu-22.04
-
-    if: >-
-      ${{!(false
-      || contains(github.event.head_commit.message, '[DOC]')
-      || contains(github.event.pull_request.title, '[DOC]')
-      || contains(github.event.pull_request.labels.*.name, 'Documentation')
-      || (github.event_name == 'push' && github.actor == 'dependabot[bot]')
-      )}}
-
-    steps:
-      - uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4.1.1
-        with:
-          sparse-checkout-cone-mode: false
-          sparse-checkout: /.github
-
-      - uses: ./.github/actions/setup/ubuntu
-
-      - uses: ./.github/actions/setup/directories
-        with:
-          srcdir: src
-          builddir: build
-          makeup: true
-
-      - name: Run configure
-        env:
-          arch: ${{ matrix.arch }}
-        run: >-
-          $SETARCH ../src/configure -C --disable-install-doc cppflags=-DRUBY_DEBUG
-          ${arch:+--target=$arch-$OSTYPE --host=$arch-$OSTYPE}
-
-      - run: $SETARCH make
-
-      - name: make test
-        run: |
-          $SETARCH make -s test RUN_OPTS="$RUN_OPTS"
-        timeout-minutes: 30
-        env:
-          GNUMAKEFLAGS: ''
-          RUBY_TESTOPTS: '-v --tty=no'
-          RUN_OPTS: ${{ matrix.run_opts }}
-
-      - name: make test-all
-        run: |
-          $SETARCH make -s test-all RUN_OPTS="$RUN_OPTS"
-        timeout-minutes: 40
-        env:
-          GNUMAKEFLAGS: ''
-          RUBY_TESTOPTS: '-q --tty=no'
-          RUN_OPTS: ${{ matrix.run_opts }}
-
-      - name: make test-spec
-        run: |
-          $SETARCH make -s test-spec RUN_OPTS="$RUN_OPTS"
-        timeout-minutes: 10
-        env:
-          GNUMAKEFLAGS: ''
-          RUN_OPTS: ${{ matrix.run_opts }}
-
-      - uses: ./.github/actions/slack
-        with:
-          label: ${{ matrix.run_opts }}
-          SLACK_WEBHOOK_URL: ${{ secrets.SIMPLER_ALERTS_URL }} # ruby-lang slack: ruby/simpler-alerts-bot
-        if: ${{ failure() }}
-
-defaults:
-  run:
-    working-directory: build
diff --git a/.github/workflows/rust-warnings.yml b/.github/workflows/rust-warnings.yml
new file mode 100644
index 0000000000..7ea7d0c950
--- /dev/null
+++ b/.github/workflows/rust-warnings.yml
@@ -0,0 +1,62 @@
+# Surface Rust warnings on PRs that touch any Rust code.
+# Not a required check so we never block people over new warnings
+# that might come from a new Rust version being released.
+name: Rust warnings
+on:
+  pull_request:
+    types:
+      - opened
+      - synchronize
+      - reopened
+    paths:
+      - '**.rs'
+      - '!**.inc.rs'
+  merge_group:
+
+concurrency:
+  group: ${{ github.workflow }} / ${{ startsWith(github.event_name, 'pull') && github.ref_name || github.sha }}
+  cancel-in-progress: ${{ startsWith(github.event_name, 'pull') }}
+
+permissions:
+  contents: read
+
+jobs:
+  rust-warnings:
+    env:
+      GITPULLOPTIONS: --no-tags origin ${{ github.ref }}
+
+    runs-on: ubuntu-24.04
+
+    if: >-
+      ${{!(false
+      || contains(github.event.head_commit.message, '[DOC]')
+      || contains(github.event.pull_request.title, '[DOC]')
+      || contains(github.event.pull_request.labels.*.name, 'Documentation')
+      || (github.event.pull_request.user.login == 'dependabot[bot]' && !startsWith(github.head_ref, 'dependabot/cargo'))
+      )}}
+
+    steps:
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with:
+          persist-credentials: false
+
+      - name: Install Rust
+        run: rustup default beta
+
+      - name: Rust warnings
+        shell: bash
+        run: |
+          set -eu
+          cargo check --quiet --all-features --message-format=json \
+            | jq -r 'select(.message.level | IN("warning", "error")) | .message.rendered' \
+            | tee messages.txt
+          (exit "${PIPESTATUS[0]}") && ! grep --quiet '[^[:space:]]' messages.txt
+
+      - name: "📜 `rustdoc` warnings"
+        shell: bash
+        run: |
+          set -eu
+          cargo doc --document-private-items --all --no-deps --message-format=json \
+            | jq -r 'select(.message.level | IN("warning", "error")) | .message.rendered' \
+            | tee messages.txt
+          (exit "${PIPESTATUS[0]}") && ! grep --quiet '[^[:space:]]' messages.txt
diff --git a/.github/workflows/scorecards.yml b/.github/workflows/scorecards.yml
index 51ce54a518..6dc4a7c6ad 100644
--- a/.github/workflows/scorecards.yml
+++ b/.github/workflows/scorecards.yml
@@ -2,7 +2,7 @@
 # by a third-party and are governed by separate terms of service, privacy
 # policy, and support documentation.
 
-name: Scorecards supply-chain security
+name: Scorecard supply-chain security
 on:
   # For Branch-Protection check. Only the default branch is supported. See
   # https://github.com/ossf/scorecard/blob/main/docs/checks.md#branch-protection
@@ -10,7 +10,7 @@ on:
   # To guarantee Maintained check is occasionally updated. See
   # https://github.com/ossf/scorecard/blob/main/docs/checks.md#maintained
   schedule:
-    - cron: '22 4 * * 2'
+    - cron: '39 3 * * 5'
   # push:
   #   branches: [ "master" ]
 
@@ -19,8 +19,10 @@ permissions: read-all
 
 jobs:
   analysis:
-    name: Scorecards analysis
+    name: Scorecard analysis
     runs-on: ubuntu-latest
+    # `publish_results: true` only works when run from the default branch. conditional can be removed if disabled.
+    if: github.event.repository.default_branch == github.ref_name || github.event_name == 'pull_request'
     permissions:
       # Needed to upload the results to code-scanning dashboard.
       security-events: write
@@ -31,21 +33,21 @@ jobs:
       # actions: read
 
     steps:
-      - name: 'Checkout code'
-        uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4.1.1
+      - name: "Checkout code"
+        uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
         with:
           persist-credentials: false
 
-      - name: 'Run analysis'
-        uses: ossf/scorecard-action@0864cf19026789058feabb7e87baa5f140aac736 # v2.3.1
+      - name: "Run analysis"
+        uses: ossf/scorecard-action@4eaacf0543bb3f2c246792bd56e8cdeffafb205a # v2.4.3
         with:
           results_file: results.sarif
           results_format: sarif
-          # (Optional) Read-only PAT token. Uncomment the `repo_token` line below if:
+          # (Optional) "write" PAT token. Uncomment the `repo_token` line below if:
           # - you want to enable the Branch-Protection check on a *public* repository, or
-          # - you are installing Scorecards on a *private* repository
-          # To create the PAT, follow the steps in https://github.com/ossf/scorecard-action#authentication-with-pat.
-          repo_token: ${{ secrets.SCORECARD_READ_TOKEN }}
+          # - you are installing Scorecard on a *private* repository
+          # To create the PAT, follow the steps in https://github.com/ossf/scorecard-action?tab=readme-ov-file#authentication-with-fine-grained-pat-optional.
+          # repo_token: ${{ secrets.SCORECARD_TOKEN }}
 
           # Public repositories:
           #   - Publish results to OpenSSF REST API for easy access by consumers
@@ -56,17 +58,21 @@ jobs:
           #     of the value entered here.
           publish_results: true
 
+          # (Optional) Uncomment file_mode if you have a .gitattributes with files marked export-ignore
+          # file_mode: git
+
       # Upload the results as artifacts (optional). Commenting out will disable uploads of run results in SARIF
       # format to the repository Actions tab.
-      # - name: "Upload artifact"
-      #   uses: actions/upload-artifact@0b7f8abb1508181956e8e162db84b466c27e18ce # v3.1.2
-      #   with:
-      #     name: SARIF file
-      #     path: results.sarif
-      #     retention-days: 5
+      - name: "Upload artifact"
+        uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7.0.1
+        with:
+          name: SARIF file
+          path: results.sarif
+          retention-days: 5
 
-      # Upload the results to GitHub's code scanning dashboard.
-      - name: 'Upload to code-scanning'
-        uses: github/codeql-action/upload-sarif@cdcdbb579706841c47f7063dda365e292e5cad7a # v2.1.27
+      # Upload the results to GitHub's code scanning dashboard (optional).
+      # Commenting out will disable upload of results to your repo's Code Scanning dashboard
+      - name: "Upload to code-scanning"
+        uses: github/codeql-action/upload-sarif@8aad20d150bbac5944a9f9d289da16a4b0d87c1e # v4.36.2
         with:
           sarif_file: results.sarif
diff --git a/.github/workflows/spec_guards.yml b/.github/workflows/spec_guards.yml
index 8974b56e4b..39714b13a4 100644
--- a/.github/workflows/spec_guards.yml
+++ b/.github/workflows/spec_guards.yml
@@ -3,16 +3,15 @@ name: Rubyspec Version Guards Check
 on:
   push:
     paths:
+      - '.github/workflows/spec_guards.yml'
       - 'spec/**'
       - '!spec/*.md'
   pull_request:
-    paths-ignore:
+    paths:
+      - '.github/workflows/spec_guards.yml'
       - 'spec/**'
       - '!spec/*.md'
   merge_group:
-    paths-ignore:
-      - 'spec/**'
-      - '!spec/*.md'
 
 concurrency:
   group: ${{ github.workflow }} / ${{ startsWith(github.event_name, 'pull') && github.ref_name || github.sha }}
@@ -25,14 +24,14 @@ jobs:
   rubyspec:
     name: Rubyspec
 
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-22.04
 
     if: >-
       ${{!(false
       || contains(github.event.head_commit.message, '[DOC]')
       || contains(github.event.pull_request.title, '[DOC]')
       || contains(github.event.pull_request.labels.*.name, 'Documentation')
-      || (github.event_name == 'push' && github.actor == 'dependabot[bot]')
+      || (github.event.pull_request.user.login == 'dependabot[bot]')
       )}}
 
     strategy:
@@ -40,14 +39,17 @@ jobs:
         # Specs from ruby/spec should still run on all supported Ruby versions.
         # This also ensures the needed ruby_version_is guards are there, see spec/README.md.
         ruby:
-          - ruby-3.0
-          - ruby-3.1
-          - ruby-3.2
+          - ruby-3.3
+          - ruby-3.4
+          - ruby-4.0
+      fail-fast: false
 
     steps:
-      - uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4.1.1
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with:
+          persist-credentials: false
 
-      - uses: ruby/setup-ruby@a05e47355e80e57b9a67566a813648fa67d92011 # v1.157.0
+      - uses: ruby/setup-ruby@afeafc3d1ab54a631816aba4c914a0081c12ff2f # v1.310.0
         with:
           ruby-version: ${{ matrix.ruby }}
           bundler: none
diff --git a/.github/workflows/sync_default_gems.yml b/.github/workflows/sync_default_gems.yml
new file mode 100644
index 0000000000..3aaae5864f
--- /dev/null
+++ b/.github/workflows/sync_default_gems.yml
@@ -0,0 +1,80 @@
+name: Sync default gems
+
+env:
+  DEFAULT_GEM_SYNC_ENABLED: true
+
+on:
+  workflow_dispatch:
+    inputs:
+      gem:
+        required: true
+        description: 'Name of the gem to be synchronized'
+        type: string
+      before:
+        required: true
+        description: 'Gem commit SHA before sync'
+        type: string
+      after:
+        required: true
+        description: 'Gem commit SHA after sync'
+        type: string
+
+permissions:
+  contents: read
+
+jobs:
+  sync_default_gems:
+    name: Sync default gem ${{ github.event.inputs.gem }}
+
+    permissions:
+      contents: write # for Git to git push
+
+    runs-on: ubuntu-latest
+
+    if: ${{ github.repository == 'ruby/ruby' }}
+
+    steps:
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        name: Check out ruby/ruby
+        with:
+          token: ${{ github.repository == 'ruby/ruby' && secrets.MATZBOT_AUTO_UPDATE_TOKEN || secrets.GITHUB_TOKEN }}
+
+      - uses: ruby/setup-ruby@afeafc3d1ab54a631816aba4c914a0081c12ff2f # v1.310.0
+        with:
+          ruby-version: '3.4'
+          bundler: none
+
+      - name: Run tool/sync_default_gems.rb
+        id: sync
+        run: |
+          ruby_before=$(git rev-parse HEAD)
+          set -x
+          ruby tool/sync_default_gems.rb "${gem_name}" "${gem_before}..${gem_after}"
+          if [[ "$(git rev-parse HEAD)" != "$ruby_before" ]]; then
+            echo update=true >> $GITHUB_OUTPUT
+          fi
+        env:
+          gem_name: ${{ github.event.inputs.gem }}
+          gem_before: ${{ github.event.inputs.before }}
+          gem_after: ${{ github.event.inputs.after }}
+          EMAIL: svn-admin@ruby-lang.org
+          GIT_AUTHOR_NAME: git
+          GIT_COMMITTER_NAME: git
+
+      - name: Push
+        run: |
+          git pull --rebase origin ${GITHUB_REF#refs/heads/}
+          git push origin ${GITHUB_REF#refs/heads/}
+        if: ${{ steps.sync.outputs.update && env.DEFAULT_GEM_SYNC_ENABLED == 'true' }}
+        env:
+          EMAIL: svn-admin@ruby-lang.org
+          GIT_AUTHOR_NAME: git
+          GIT_COMMITTER_NAME: git
+
+      - uses: ./.github/actions/slack
+        with:
+          SLACK_WEBHOOK_URL: ${{ secrets.SIMPLER_ALERTS_URL }} # ruby-lang slack: ruby/simpler-alerts-bot
+          label: "${{ github.event.inputs.gem }} (<https://github.com/${{ github.event.inputs.gem == 'rubygems' && 'rubygems' || 'ruby' }}/${{ github.event.inputs.gem }}/compare/${{ github.event.inputs.before }}...${{ github.event.inputs.after }}|diff>)"
+          event_name: workflow_dispatch
+          extra_channel_id: C05FPKAU743 # alerts-sync
+        if: ${{ failure() }}
diff --git a/.github/workflows/tarball-macos.yml b/.github/workflows/tarball-macos.yml
new file mode 100644
index 0000000000..0d02cf6ae1
--- /dev/null
+++ b/.github/workflows/tarball-macos.yml
@@ -0,0 +1,101 @@
+name: tarball-macos (reusable)
+
+on:
+  workflow_call:
+    inputs:
+      archname:
+        description: 'archname (e.g. snapshot-master, snapshot-ruby_3_3)'
+        required: true
+        type: string
+      notify-release-channel:
+        description: 'Also send failure notifications to SNAPSHOT_SLACK_WEBHOOK_URL (schedule/release builds).'
+        required: false
+        type: boolean
+        default: false
+    secrets:
+      SIMPLER_ALERTS_URL:
+        required: false
+      SNAPSHOT_SLACK_WEBHOOK_URL:
+        required: false
+
+permissions:
+  contents: read
+
+jobs:
+  macos:
+    strategy:
+      matrix:
+        test_task: [check, test-bundled-gems, test-bundler-parallel]
+        os: [macos-26, macos-15, macos-14]
+        include:
+          - os: macos-15-intel
+            test_task: check
+      fail-fast: false
+    runs-on: ${{ matrix.os }}
+    env:
+      ARCHNAME: ${{ inputs.archname }}
+    steps:
+      - uses: actions/download-artifact@3e5f45b2cfb9172054b4087a40e8e0b5a5461e7c # v8.0.1
+        with:
+          name: Packages
+          path: pkg
+      - name: Extract
+        run: tar xf pkg/*.tar.xz
+      - name: Install libraries
+        run: |
+          with_retry () {
+            "$@" || { sleep 5 && "$@"; } || { sleep 60 && "$@"; }
+          }
+          set -x
+          with_retry brew install gmp libffi openssl zlib autoconf automake libtool libyaml
+      - name: Set ENV
+        run: |
+          echo "JOBS=-j$((1 + $(sysctl -n hw.activecpu)))" >> $GITHUB_ENV
+      - name: configure
+        run: cd "$ARCHNAME/" && ./configure --with-openssl-dir=$(brew --prefix openssl) --with-libyaml-dir=$(brew --prefix libyaml)
+      - name: make
+        run: cd "$ARCHNAME/" && make $JOBS
+      - name: Tests
+        run: cd "$ARCHNAME/" && make $JOBS -s ${{ matrix.test_task }}
+        env:
+          RUBY_TESTOPTS: "-q --tty=no"
+          RUBY_DEBUG_TEST_NO_REMOTE: "1"
+      # leaked-globals since 2.7
+      - name: Leaked Globals
+        run: cd "$ARCHNAME/" && make -s leaked-globals
+        if: matrix.test_task == 'check'
+      - name: make install without root privilege
+        run: cd "$ARCHNAME/" && make $JOBS install DESTDIR="/tmp/destdir"
+        if: matrix.test_task == 'check'
+      - name: make install
+        run: cd "$ARCHNAME/" && sudo make $JOBS install
+        if: matrix.test_task == 'check'
+      - name: Verify installed binaries
+        run: |
+          /usr/local/bin/ruby -v
+          /usr/local/bin/gem -v
+          /usr/local/bin/bundle -v
+        if: matrix.test_task == 'check'
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with:
+          sparse-checkout: .github/actions/slack
+          sparse-checkout-cone-mode: false
+          persist-credentials: false
+        if: ${{ failure() }}
+      - uses: ./.github/actions/slack
+        with:
+          label: "${{ matrix.os }} / ${{ matrix.test_task }}"
+          SLACK_WEBHOOK_URL: ${{ secrets.SIMPLER_ALERTS_URL }} # ruby-lang slack: ruby/simpler-alerts-bot
+        if: ${{ failure() }}
+      - uses: ruby/action-slack@d260b61aa817726d5bedd22dd6cc305787fa4cdd # v4.0.0
+        with:
+          payload: |
+            {
+              "attachments": [{
+                "text": "${{ job.status }}: ${{ matrix.os }} / ${{ matrix.test_task }} <https://github.com/${{ github.repository }}/actions/runs/${{ github.run_id }}|${{ inputs.archname }}>",
+                "color": "danger"
+              }]
+            }
+        env:
+          SLACK_WEBHOOK_URL: ${{ secrets.SNAPSHOT_SLACK_WEBHOOK_URL }}
+        if: failure() && inputs.notify-release-channel
diff --git a/.github/workflows/tarball-non-development.yml b/.github/workflows/tarball-non-development.yml
new file mode 100644
index 0000000000..db6230b301
--- /dev/null
+++ b/.github/workflows/tarball-non-development.yml
@@ -0,0 +1,87 @@
+name: tarball-non-development (reusable)
+
+on:
+  workflow_call: {}
+
+permissions:
+  contents: read
+
+jobs:
+  non_development:
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - { variant: default,     remove_ruby: false, configure_extra: '' }
+          - { variant: no-ruby,     remove_ruby: true,  configure_extra: '' }
+          - { variant: baseruby-no, remove_ruby: false, configure_extra: '--with-baseruby=no' }
+    runs-on: ubuntu-24.04
+    env:
+      ruby_prefix: /tmp/ruby-snapshot
+    steps:
+      - uses: actions/download-artifact@3e5f45b2cfb9172054b4087a40e8e0b5a5461e7c # v8.0.1
+        with:
+          name: Packages
+          path: pkg
+      - name: Extract
+        run: tar xf pkg/*.tar.xz
+      - name: Substitute patchlevel
+        run: |
+          set -x
+          cd snapshot-*/
+          sed -i.orig 's/^\( *# *define  *RUBY_PATCHLEVEL\)  *-.*/\1 0/' version.h
+          diff -u version.h.orig version.h || :
+          rm -f version.h.orig
+      - 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 zlib1g-dev libffi-dev libgmp-dev bison- autoconf-
+      - name: Remove host ruby
+        if: matrix.remove_ruby
+        run: |
+          set -x
+          sudo apt-get purge -y -q 'ruby*' || :
+          sudo rm -rf /opt/hostedtoolcache/Ruby
+          ! command -v ruby
+      - name: Set ENV
+        run: |
+          echo "JOBS=-j$((1 + $(nproc --all)))" >> $GITHUB_ENV
+      - name: configure
+        run: cd snapshot-*/ && ./configure --prefix="${ruby_prefix}" ${{ matrix.configure_extra }}
+      - name: make
+        run: cd snapshot-*/ && make $JOBS
+      - name: Leaked Globals
+        run: cd snapshot-*/ && make -s leaked-globals
+      - name: make install
+        run: cd snapshot-*/ && make $JOBS install
+      - name: Set PATH
+        run: echo "PATH=${ruby_prefix}/bin:$PATH" >> $GITHUB_ENV
+      - name: Check patchlevel
+        id: check-patchlevel
+        run: |
+          exec "${ruby_prefix}/bin/ruby" -vx "$0"
+          #!ruby
+          puts "RUBY_PATCHLEVEL=#{RUBY_PATCHLEVEL.inspect}"
+          abort unless RUBY_PATCHLEVEL >= 0
+        working-directory: ${{ env.ruby_prefix }}
+        continue-on-error: true
+      - name: Check LOADPATH
+        id: check-loadpath
+        run: |
+          exec ${ruby_prefix}/bin/ruby -vx "$0"
+          #!ruby
+          paths = $:.grep(/\+/)
+          pp paths
+          abort unless paths.empty?
+        working-directory: ${{ env.ruby_prefix }}
+        continue-on-error: true
+      - name: Check pathnames
+        id: check-pathnames
+        run: |
+          ! find -name '*+*' | grep +
+        working-directory: ${{ env.ruby_prefix }}
+        continue-on-error: true
+      - name: result
+        run: false
+        if: ${{ contains(steps.*.outcome, 'failure') }}
diff --git a/.github/workflows/tarball-test-schedule.yml b/.github/workflows/tarball-test-schedule.yml
new file mode 100644
index 0000000000..6684b09edb
--- /dev/null
+++ b/.github/workflows/tarball-test-schedule.yml
@@ -0,0 +1,26 @@
+name: tarball-test-schedule
+on:
+  schedule:
+    - cron: '30 18 * * *' # Daily at 18:30 UTC
+  workflow_dispatch:
+
+permissions: {}
+
+jobs:
+  dispatch:
+    if: ${{ github.event_name != 'schedule' || github.repository == 'ruby/ruby' }}
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        branch:
+          - master
+          - ruby_4_0
+          - ruby_3_4
+          - ruby_3_3
+    steps:
+      - name: Trigger tarball-test on ${{ matrix.branch }}
+        run: gh workflow run tarball-test.yml --ref "$BRANCH" --repo "$GITHUB_REPOSITORY" -f notify-release-channel=true
+        env:
+          BRANCH: ${{ matrix.branch }}
+          GH_TOKEN: ${{ secrets.MATZBOT_GITHUB_ACTION_TOKEN }}
diff --git a/.github/workflows/tarball-test.yml b/.github/workflows/tarball-test.yml
new file mode 100644
index 0000000000..f75d76761a
--- /dev/null
+++ b/.github/workflows/tarball-test.yml
@@ -0,0 +1,104 @@
+name: tarball-test
+on:
+  push:
+    paths-ignore:
+      - 'doc/**'
+      - '**/man/*'
+      - '**.md'
+      - '**.rdoc'
+      - '**/.document'
+      - '.*.yml'
+  pull_request:
+    # Do not use paths-ignore for required status checks
+    # https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/collaborating-on-repositories-with-code-quality-features/troubleshooting-required-status-checks#handling-skipped-but-required-checks
+  merge_group:
+  workflow_dispatch:
+    inputs:
+      notify-release-channel:
+        description: 'Also send failure notifications to SNAPSHOT_SLACK_WEBHOOK_URL (set by tarball-test-schedule).'
+        type: boolean
+        default: false
+
+concurrency:
+  group: ${{ github.workflow }} / ${{ startsWith(github.event_name, 'pull') && github.ref_name || github.sha }}
+  cancel-in-progress: ${{ startsWith(github.event_name, 'pull') }}
+
+permissions:
+  contents: read
+
+jobs:
+  tarball:
+    runs-on: ubuntu-latest
+    # Cherry-pick to maintenance branches by changing only env.BRANCH below;
+    # archname / branch-label / Materialize all derive from it.
+    env:
+      BRANCH: master
+    outputs:
+      branch: ${{ env.BRANCH }}
+      skip: ${{ steps.skipping.outputs.skip }}
+    steps:
+      - id: skipping
+        run: echo 'skip=true' >> $GITHUB_OUTPUT
+        if: >-
+          ${{(false
+          || contains(github.event.head_commit.message, '[DOC]')
+          || contains(github.event.pull_request.title, '[DOC]')
+          || contains(github.event.pull_request.labels.*.name, 'Documentation')
+          || (github.event.pull_request.user.login == 'dependabot[bot]')
+          )}}
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with:
+          fetch-depth: 1 # actions/checkout fetches all heads/tags unless > 0
+          persist-credentials: false
+      # tool/make-snapshot derives the branch name from HEAD and looks up
+      # the upstream during ChangeLog generation. Detached checkouts
+      # (pull_request, merge_group) lack a local branch with tracking, so
+      # pin one to HEAD and connect it to the matching origin ref.
+      - name: Materialize local branch
+        run: |
+          git fetch --no-tags --depth=1 origin "+refs/heads/$BASE:refs/remotes/origin/$BASE"
+          git checkout -B "$BRANCH" HEAD
+          git branch --set-upstream-to="origin/$BASE" "$BRANCH"
+        env:
+          BASE: ${{ github.base_ref || env.BRANCH }}
+      - uses: ./.github/actions/make-snapshot
+        with:
+          archname: snapshot-${{ env.BRANCH }}
+          srcdir: '.'
+
+  ubuntu:
+    needs: tarball
+    if: ${{ ! needs.tarball.outputs.skip }}
+    uses: ./.github/workflows/tarball-ubuntu.yml
+    with:
+      archname: snapshot-${{ needs.tarball.outputs.branch }}
+      notify-release-channel: ${{ github.event_name == 'workflow_dispatch' && inputs.notify-release-channel || false }}
+    secrets:
+      SIMPLER_ALERTS_URL: ${{ secrets.SIMPLER_ALERTS_URL }}
+      SNAPSHOT_SLACK_WEBHOOK_URL: ${{ secrets.SNAPSHOT_SLACK_WEBHOOK_URL }}
+
+  macos:
+    needs: tarball
+    if: ${{ ! needs.tarball.outputs.skip }}
+    uses: ./.github/workflows/tarball-macos.yml
+    with:
+      archname: snapshot-${{ needs.tarball.outputs.branch }}
+      notify-release-channel: ${{ github.event_name == 'workflow_dispatch' && inputs.notify-release-channel || false }}
+    secrets:
+      SIMPLER_ALERTS_URL: ${{ secrets.SIMPLER_ALERTS_URL }}
+      SNAPSHOT_SLACK_WEBHOOK_URL: ${{ secrets.SNAPSHOT_SLACK_WEBHOOK_URL }}
+
+  windows:
+    needs: tarball
+    if: ${{ ! needs.tarball.outputs.skip }}
+    uses: ./.github/workflows/tarball-windows.yml
+    with:
+      archname: snapshot-${{ needs.tarball.outputs.branch }}
+      notify-release-channel: ${{ github.event_name == 'workflow_dispatch' && inputs.notify-release-channel || false }}
+    secrets:
+      SIMPLER_ALERTS_URL: ${{ secrets.SIMPLER_ALERTS_URL }}
+      SNAPSHOT_SLACK_WEBHOOK_URL: ${{ secrets.SNAPSHOT_SLACK_WEBHOOK_URL }}
+
+  non_development:
+    needs: tarball
+    uses: ./.github/workflows/tarball-non-development.yml
diff --git a/.github/workflows/tarball-ubuntu.yml b/.github/workflows/tarball-ubuntu.yml
new file mode 100644
index 0000000000..0482db3c7f
--- /dev/null
+++ b/.github/workflows/tarball-ubuntu.yml
@@ -0,0 +1,151 @@
+name: tarball-ubuntu (reusable)
+
+on:
+  workflow_call:
+    inputs:
+      archname:
+        description: 'archname (e.g. snapshot-master, snapshot-ruby_3_3)'
+        required: true
+        type: string
+      notify-release-channel:
+        description: 'Also send failure notifications to SNAPSHOT_SLACK_WEBHOOK_URL (schedule/release builds).'
+        required: false
+        type: boolean
+        default: false
+    secrets:
+      SIMPLER_ALERTS_URL:
+        required: false
+      SNAPSHOT_SLACK_WEBHOOK_URL:
+        required: false
+
+permissions:
+  contents: read
+
+jobs:
+  ubuntu:
+    strategy:
+      matrix:
+        test_task: [check, test-bundler-parallel, test-bundled-gems]
+        os: [ubuntu-24.04, ubuntu-22.04]
+      fail-fast: false
+    runs-on: ${{ matrix.os }}
+    env:
+      ARCHNAME: ${{ inputs.archname }}
+    steps:
+      - uses: actions/download-artifact@3e5f45b2cfb9172054b4087a40e8e0b5a5461e7c # v8.0.1
+        with:
+          name: Packages
+          path: pkg
+      - name: Extract
+        run: tar xf pkg/*.tar.xz
+      - 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 zlib1g-dev libffi-dev libgmp-dev bison- autoconf-
+      - uses: ruby/setup-ruby@afeafc3d1ab54a631816aba4c914a0081c12ff2f # v1.310.0
+        with:
+          ruby-version: '3.2'
+        # test-bundled-gems requires executable host ruby
+        if: matrix.test_task == 'test-bundled-gems'
+      - name: Fixed world writable dirs
+        run: |
+          mkdir -p $HOME/.local/share
+          mkdir -p $HOME/.cache/gem/specs
+          mkdir -p $HOME/.bundle/cache
+          mkdir -p $HOME/.ssh
+          chmod a-w $HOME/.bundle
+          # chmod a-w $HOME
+          # allow to write $HOME and check stats of HOME around tests (see below)
+          chmod -v a-w $HOME/.config
+          sudo chmod -R a-w /usr/share
+          sudo bash -c 'IFS=:; for d in '"$PATH"'; do chmod -v a-w $d; done' || :
+      - name: Set ENV
+        run: |
+          echo "JOBS=-j$((1 + $(nproc --all)))" >> $GITHUB_ENV
+      - name: configure
+        run: cd "$ARCHNAME/" && ./configure
+      - name: make
+        run: cd "$ARCHNAME/" && make $JOBS
+      - name: Save stats of HOME
+        run: |
+          set -euxo pipefail
+          cat >"$ARCHNAME/save-stats.rb" <<'EOF'
+          require 'pathname'
+          require 'digest'
+          out = []
+          [
+            Dir.home,
+          ].each do |dir|
+            Dir.each_child(dir) do |name|
+              pn = File.join(dir, name)
+              st = File.stat(pn)
+              if st.file?
+                content = Digest::SHA1.file(pn).hexdigest
+              elsif st.directory? && st.nlink <= 10
+                content = Dir.children(pn).sort
+              end
+              out << [pn, "%o"%st.mode, st.nlink, st.uid, st.gid, st.size, content].to_s
+            rescue
+              out << [pn, $!.inspect].to_s
+            end
+          end
+          File.open(ARGV.shift, "w") do |io|
+            io.puts out.sort
+          end
+          EOF
+          make -C "$ARCHNAME" TESTRUN_SCRIPT=save-stats.rb RUNOPT=/tmp/stat-before-tests.txt runruby
+      - name: Tests
+        run: cd "$ARCHNAME/" && make $JOBS -s ${{ matrix.test_task }}
+        env:
+          RUBY_TESTOPTS: "-q --tty=no"
+      # test_sync_default_gems triggers gpg, whose agent processes leave
+      # $HOME/.gnupg around even when GNUPGHOME points elsewhere.
+      - name: Forcibly remove ~/.gnupg
+        run: rm -rf $HOME/.gnupg
+      - name: Diff stats of HOME
+        run: |
+          make -C "$ARCHNAME" TESTRUN_SCRIPT=save-stats.rb RUNOPT=/tmp/stat-after-tests.txt runruby
+          rm -f "$ARCHNAME/save-stats.rb"
+          diff -u /tmp/stat-before-tests.txt /tmp/stat-after-tests.txt
+      # leaked-globals since 2.7
+      - name: Leaked Globals
+        run: cd "$ARCHNAME/" && make -s leaked-globals
+        if: matrix.test_task == 'check'
+      - name: make install without root privilege
+        run: cd "$ARCHNAME/" && make $JOBS install DESTDIR="/tmp/destdir"
+        if: matrix.test_task == 'check'
+      - name: make install
+        run: cd "$ARCHNAME/" && sudo make $JOBS install
+        if: matrix.test_task == 'check'
+      - name: Verify installed binaries
+        run: |
+          /usr/local/bin/ruby -v
+          /usr/local/bin/gem -v
+          /usr/local/bin/bundle -v
+        if: matrix.test_task == 'check'
+      - name: Show .local
+        run: find $HOME/.local -ls
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with:
+          sparse-checkout: .github/actions/slack
+          sparse-checkout-cone-mode: false
+          persist-credentials: false
+        if: ${{ failure() }}
+      - uses: ./.github/actions/slack
+        with:
+          label: "${{ matrix.os }} / ${{ matrix.test_task }}"
+          SLACK_WEBHOOK_URL: ${{ secrets.SIMPLER_ALERTS_URL }} # ruby-lang slack: ruby/simpler-alerts-bot
+        if: ${{ failure() }}
+      - uses: ruby/action-slack@d260b61aa817726d5bedd22dd6cc305787fa4cdd # v4.0.0
+        with:
+          payload: |
+            {
+              "attachments": [{
+                "text": "${{ job.status }}: ${{ matrix.os }} / ${{ matrix.test_task }} <https://github.com/${{ github.repository }}/actions/runs/${{ github.run_id }}|${{ inputs.archname }}>",
+                "color": "danger"
+              }]
+            }
+        env:
+          SLACK_WEBHOOK_URL: ${{ secrets.SNAPSHOT_SLACK_WEBHOOK_URL }}
+        if: failure() && inputs.notify-release-channel
diff --git a/.github/workflows/tarball-windows.yml b/.github/workflows/tarball-windows.yml
new file mode 100644
index 0000000000..a66cdf729d
--- /dev/null
+++ b/.github/workflows/tarball-windows.yml
@@ -0,0 +1,163 @@
+name: tarball-windows (reusable)
+
+on:
+  workflow_call:
+    inputs:
+      archname:
+        description: 'archname (e.g. snapshot-master)'
+        required: true
+        type: string
+      notify-release-channel:
+        description: 'Also send failure notifications to SNAPSHOT_SLACK_WEBHOOK_URL (schedule/release builds).'
+        required: false
+        type: boolean
+        default: false
+    secrets:
+      SIMPLER_ALERTS_URL:
+        required: false
+      SNAPSHOT_SLACK_WEBHOOK_URL:
+        required: false
+
+permissions:
+  contents: read
+
+jobs:
+  windows:
+    strategy:
+      matrix:
+        include:
+          - os: '2022'
+            test_task: check
+          - os: '2025-vs2026'
+            test_task: check
+      fail-fast: false
+    runs-on: windows-${{ matrix.os }}
+    defaults:
+      run:
+        shell: cmd
+        working-directory: build
+    name: Windows ${{ matrix.os }} (${{ matrix.test_task }})
+    env:
+      GITPULLOPTIONS: --no-tags origin ${{github.ref}}
+      PATCH: C:\msys64\usr\bin\patch.exe
+      OS_VER: windows-${{ matrix.os }}
+      # see https://github.com/ruby/ruby/commit/9ff4399decef0036897d3cfb9ac2c710dea913ca
+      OPENSSL_MODULES: C:\vcpkg\installed\x64-windows\bin
+    steps:
+      - run: md build
+        working-directory:
+
+      - uses: ruby/setup-ruby@afeafc3d1ab54a631816aba4c914a0081c12ff2f # v1.310.0
+        with:
+          ruby-version: '3.2'
+          bundler: none
+          windows-toolchain: none
+
+      - uses: msys2/setup-msys2@e9898307ac31d1a803454791be09ab9973336e1c # v2.31.1
+        id: setup-msys2
+        with:
+          update: true
+          install: >-
+            patch
+      - name: patch path
+        shell: msys2 {0}
+        run: echo PATCH=$(cygpath -wa $(command -v patch)) >> $GITHUB_ENV
+        if: ${{ steps.setup-msys2.outcome == 'success' }}
+      - uses: actions/cache@27d5ce7f107fe9357f9df03efb73ab90386fccae # v5.0.5
+        with:
+          path: C:\vcpkg\installed
+          key: ${{ runner.os }}-vcpkg-installed-${{ env.OS_VER }}-${{ github.sha }}
+          restore-keys: |
+            ${{ runner.os }}-vcpkg-installed-${{ env.OS_VER }}-
+            ${{ runner.os }}-vcpkg-installed-
+      - name: Install libraries with vcpkg
+        run: |
+          vcpkg --triplet x64-windows install gmp libffi libyaml openssl zlib
+
+      - uses: actions/download-artifact@3e5f45b2cfb9172054b4087a40e8e0b5a5461e7c # v8.0.1
+        with:
+          name: Packages
+          path: pkg
+      - name: Extract
+        run: 7z x pkg/*.zip
+        working-directory:
+
+      - uses: actions/cache@27d5ce7f107fe9357f9df03efb73ab90386fccae # v5.0.5
+        with:
+          path: snapshot-*/.downloaded-cache
+          key: downloaded-cache
+
+      - name: setup env
+        # %TEMP% is inconsistent with %TMP% and test-all expects they are consistent.
+        # https://github.com/actions/virtual-environments/issues/712#issuecomment-613004302
+        env:
+          ARCHNAME: ${{ inputs.archname }}
+        run: |
+          set > old.env
+          call ..\%ARCHNAME%\win32\vssetup.cmd
+          set TMP=%USERPROFILE%\AppData\Local\Temp
+          set TEMP=%USERPROFILE%\AppData\Local\Temp
+          set /a TEST_JOBS=(15 * %NUMBER_OF_PROCESSORS% / 10) > nul
+          set > new.env
+
+      - name: update env
+        shell: pwsh
+        run: |
+          $old = (Get-Content old.env); $new = (Get-Content new.env)
+          del *.env
+          Compare-Object $old $new |
+            Where-Object { $_.SideIndicator -eq '=>' } |
+            Select-Object -ExpandProperty InputObject |
+            Add-Content -Path $env:GITHUB_ENV
+      - name: link libraries
+        run: |
+          for %%I in (C:\vcpkg\installed\x64-windows\bin\*.dll) do (
+            mklink %%~nxI %%I
+          )
+      - name: Configure
+        env:
+          ARCHNAME: ${{ inputs.archname }}
+        run: >-
+          ../%ARCHNAME%/win32/configure.bat --disable-install-doc
+          --with-opt-dir=C:/vcpkg/installed/x64-windows
+      - run: nmake incs
+      - run: nmake extract-extlibs
+      - run: nmake
+        env:
+          YACC: win_bison
+
+      - name: ruby -v
+        run: .\ruby -v
+
+      - run: nmake test
+        timeout-minutes: 5
+
+      - run: nmake ${{ matrix.test_task }}
+        env:
+          RUBY_TESTOPTS: -j${{env.TEST_JOBS}}
+        timeout-minutes: 70
+        continue-on-error: ${{ matrix.continue-on-error || false }}
+
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with:
+          sparse-checkout: .github/actions/slack
+          sparse-checkout-cone-mode: false
+          persist-credentials: false
+        if: ${{ failure() }}
+      - uses: ./.github/actions/slack
+        with:
+          label: "${{ env.OS_VER }} / ${{ matrix.test_task }}"
+          SLACK_WEBHOOK_URL: ${{ secrets.SIMPLER_ALERTS_URL }} # ruby-lang slack: ruby/simpler-alerts-bot
+        if: ${{ failure() }}
+      - uses: ruby/action-slack@d260b61aa817726d5bedd22dd6cc305787fa4cdd # v4.0.0
+        with:
+          payload: |
+            {
+              "attachments": [{
+                "text": "${{ job.status }}: ${{ env.OS_VER }} / ${{ matrix.test_task }} <https://github.com/${{ github.repository }}/actions/runs/${{ github.run_id }}|${{ inputs.archname }}>",
+                "color": "danger"
+              }]
+            }
+        env:
+          SLACK_WEBHOOK_URL: ${{ secrets.SNAPSHOT_SLACK_WEBHOOK_URL }}
+        if: failure() && inputs.notify-release-channel
diff --git a/.github/workflows/ubuntu.yml b/.github/workflows/ubuntu.yml
index e701a98515..c887ae3811 100644
--- a/.github/workflows/ubuntu.yml
+++ b/.github/workflows/ubuntu.yml
@@ -3,20 +3,15 @@ on:
   push:
     paths-ignore:
       - 'doc/**'
-      - '**/man'
+      - '**/man/*'
       - '**.md'
       - '**.rdoc'
       - '**/.document'
+      - '.*.yml'
   pull_request:
     # Do not use paths-ignore for required status checks
     # https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/collaborating-on-repositories-with-code-quality-features/troubleshooting-required-status-checks#handling-skipped-but-required-checks
   merge_group:
-    paths-ignore:
-      - 'doc/**'
-      - '**/man'
-      - '**.md'
-      - '**.rdoc'
-      - '**/.document'
 
 concurrency:
   group: ${{ github.workflow }} / ${{ startsWith(github.event_name, 'pull') && github.ref_name || github.sha }}
@@ -29,59 +24,76 @@ jobs:
   make:
     strategy:
       matrix:
-        test_task: [check]
-        arch: ['']
-        configure: ['cppflags=-DVM_CHECK_MODE']
-        # specifying other jobs with `include` to avoid redundant tests
+        # We enumerate every job in matrix.include to save build time
         include:
           - test_task: check
+            configure: 'cppflags=-DVM_CHECK_MODE'
+          - test_task: check
             arch: i686
           - test_task: check
+            configure: '--disable-yjit'
+          - test_task: check
             configure: '--enable-shared --enable-load-relative'
-          - test_task: test-all TESTS=--repeat-count=2
-          - test_task: test-all
-            configure: 'cppflags=-DUNIVERSAL_PARSER'
           - test_task: test-bundler-parallel
+            timeout: 50
           - test_task: test-bundled-gems
+          - test_task: check
+            os: ubuntu-24.04
+            extra_checks: [capi]
+          # ubuntu-24.04-arm jobs don't start on ruby/ruby as of 2025-10-29
+          #- test_task: check
+          #  os: ubuntu-24.04-arm
       fail-fast: false
 
-    env:
+    env: &make-env
       GITPULLOPTIONS: --no-tags origin ${{ github.ref }}
       RUBY_DEBUG: ci
 
-    runs-on: ubuntu-20.04
+    runs-on: ${{ matrix.os || 'ubuntu-22.04' }}
 
     if: >-
       ${{!(false
       || contains(github.event.head_commit.message, '[DOC]')
       || contains(github.event.pull_request.title, '[DOC]')
       || contains(github.event.pull_request.labels.*.name, 'Documentation')
-      || (github.event_name == 'push' && github.actor == 'dependabot[bot]')
+      || (github.event.pull_request.user.login == 'dependabot[bot]')
       )}}
 
-    steps:
-      - uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4.1.1
+    steps: &make-steps
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
         with:
           sparse-checkout-cone-mode: false
           sparse-checkout: /.github
+          persist-credentials: false
 
       - uses: ./.github/actions/setup/ubuntu
         with:
           arch: ${{ matrix.arch }}
 
+      - uses: ruby/setup-ruby@afeafc3d1ab54a631816aba4c914a0081c12ff2f # v1.310.0
+        with:
+          ruby-version: '3.1'
+          bundler: none
+        if: >-
+          ${{ !endsWith(matrix.os, 'arm')
+          && !endsWith(matrix.os, 'ppc64le') && !endsWith(matrix.os, 's390x') }}
+
       - uses: ./.github/actions/setup/directories
         with:
           srcdir: src
           builddir: build
           makeup: true
+          clean: true
           dummy-files: ${{ matrix.test_task == 'check' }}
+          # Set fetch-depth: 10 so that Launchable can receive commits information.
+          fetch-depth: 10
 
       - name: Run configure
         env:
           arch: ${{ matrix.arch }}
           configure: ${{ matrix.configure }}
         run: >-
-          $SETARCH ../src/configure -C --disable-install-doc ${configure:-cppflags=-DRUBY_DEBUG}
+          $SETARCH ../src/configure -C --disable-install-doc ${configure:- --enable-debug-env cppflags=-DRUBY_DEBUG}
           ${arch:+--target=$arch-$OSTYPE --host=$arch-$OSTYPE}
 
       - run: $SETARCH make prepare-gems
@@ -89,31 +101,162 @@ jobs:
 
       - run: $SETARCH make
 
+      - run: $SETARCH make hello
+
+      - name: runirb
+        run: |
+          echo IRB::VERSION | $SETARCH make runirb RUNOPT="-- -f"
+
+      - name: Set test options for skipped tests
+        run: |
+          set -x
+          TESTS="$(echo "${{ matrix.skipped_tests }}" | sed 's| |$$/ -n!/|g;s|^|-n!/|;s|$|$$/|')"
+          echo "TESTS=${TESTS}" >> $GITHUB_ENV
+        if: ${{ matrix.test_task == 'check' && matrix.skipped_tests }}
+
+      - name: Set up Launchable
+        id: launchable
+        uses: ./.github/actions/launchable/setup
+        with:
+          os: ${{ matrix.os || 'ubuntu-22.04' }}
+          test-opts: ${{ matrix.configure }}
+          launchable-token: ${{ secrets.LAUNCHABLE_TOKEN }}
+          builddir: build
+          srcdir: src
+        continue-on-error: true
+        timeout-minutes: 3
+
+      # Avoid possible test failures with the zlib applying the following patch
+      # on s390x CPU architecture.
+      # https://github.com/madler/zlib/pull/410
+      - name: Disable DFLTCC
+        run: echo "DFLTCC=0" >> $GITHUB_ENV
+        if: ${{ endsWith(matrix.os, 's390x') }}
+
       - name: make ${{ matrix.test_task }}
-        run: >-
-          $SETARCH make -s ${{ matrix.test_task }}
-          ${TESTS:+TESTS=`echo "$TESTS" | sed 's| |$$/ -n!/|g;s|^|-n!/|;s|$|$$/|'`}
+        run: |
+          test -n "${LAUNCHABLE_STDOUT}" && exec 1> >(tee "${LAUNCHABLE_STDOUT}")
+          test -n "${LAUNCHABLE_STDERR}" && exec 2> >(tee "${LAUNCHABLE_STDERR}")
+
+          $SETARCH make -s ${{ matrix.test_task }} \
+          ${TESTS:+TESTS="$TESTS"} \
           ${{ !contains(matrix.test_task, 'bundle') && 'RUBYOPT=-w' || '' }}
-        timeout-minutes: 40
+        timeout-minutes: ${{ matrix.timeout || 40 }}
         env:
           RUBY_TESTOPTS: '-q --tty=no'
-          TESTS: ${{ matrix.test_task == 'check' && matrix.skipped_tests || '' }}
           TEST_BUNDLED_GEMS_ALLOW_FAILURES: ''
           PRECHECK_BUNDLED_GEMS: 'no'
+          LAUNCHABLE_STDOUT: ${{ steps.launchable.outputs.stdout_report_path }}
+          LAUNCHABLE_STDERR: ${{ steps.launchable.outputs.stderr_report_path }}
 
       - name: make skipped tests
         run: |
-          $SETARCH make -s test-all TESTS=`echo "$TESTS" | sed 's| |$$/ -n/|g;s|^|-n/|;s|$|$$/|'`
+          $SETARCH make -s test-all TESTS="${TESTS//-n!\//-n/}"
         env:
           GNUMAKEFLAGS: ''
           RUBY_TESTOPTS: '-v --tty=no'
-          TESTS: ${{ matrix.skipped_tests }}
-        if: ${{ matrix.test_task == 'check' && matrix.skipped_tests != '' }}
+        if: ${{ matrix.test_task == 'check' && matrix.skipped_tests }}
         continue-on-error: ${{ matrix.continue-on-skipped_tests || false }}
 
+      - name: test-pc
+        run: |
+          DESTDIR=${RUNNER_TEMP-${TMPDIR-/tmp}}/installed
+          $SETARCH make test-pc "DESTDIR=$DESTDIR"
+
+      - name: CAPI extensions
+        uses: ./.github/actions/capiext
+        with:
+          builddir: build
+          make: '$SETARCH make'
+        env:
+          RUBY_TESTOPTS: '-v --tty=no'
+        if: ${{ contains(matrix.extra_checks, 'capi') }}
+
+      - uses: ./.github/actions/slack
+        with:
+          label: ${{ matrix.test_task }} ${{ matrix.configure }}${{ matrix.arch }}${{ matrix.os }}
+          SLACK_WEBHOOK_URL: ${{ secrets.SIMPLER_ALERTS_URL }} # ruby-lang slack: ruby/simpler-alerts-bot
+        if: ${{ failure() }}
+
+  make-ibm:
+    strategy:
+      matrix:
+        include:
+          - test_task: check
+            os: ubuntu-24.04-ppc64le
+          - test_task: check
+            os: ubuntu-24.04-s390x
+      fail-fast: false
+
+    env: *make-env
+
+    runs-on: ${{ matrix.os }}
+
+    if: >-
+      ${{github.repository == 'ruby/ruby'
+      && !(false
+      || contains(github.event.head_commit.message, '[DOC]')
+      || contains(github.event.pull_request.title, '[DOC]')
+      || contains(github.event.pull_request.labels.*.name, 'Documentation')
+      || (github.event.pull_request.user.login == 'dependabot[bot]')
+      )}}
+
+    steps: *make-steps
+
+  # Separated from `make` job to avoid making it a required status check
+  ruby-bench:
+    strategy:
+      matrix:
+        include:
+          # Using the same setup as ZJIT jobs
+          - bench_opts: '--warmup=1 --bench=1 --excludes=shipit'
+
+    runs-on: ubuntu-24.04
+
+    if: >-
+      ${{!(false
+      || contains(github.event.head_commit.message, '[DOC]')
+      || contains(github.event.pull_request.title, '[DOC]')
+      || contains(github.event.pull_request.labels.*.name, 'Documentation')
+      || (github.event.pull_request.user.login == 'dependabot[bot]')
+      )}}
+
+    steps:
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with:
+          persist-credentials: false
+
+      - uses: ./.github/actions/setup/ubuntu
+
+      - uses: ./.github/actions/setup/directories
+        with:
+          srcdir: src
+          builddir: build
+          makeup: true
+
+      - name: Run configure
+        run: ../src/configure -C --disable-install-doc --prefix="$(pwd)/install"
+
+      - run: make install
+
+      - name: Checkout ruby-bench
+        uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with:
+          repository: ruby/ruby-bench
+          persist-credentials: false
+          path: ruby-bench
+
+      # If you want to skip failing benchmark, consider using `--excludes`.
+      # e.g. `bench_opts: '--warmup=1 --bench=1 --excludes=railsbench,lobsters'`
+      - name: Run ruby-bench
+        run: ruby run_benchmarks.rb -e "ruby::../build/install/bin/ruby" ${{ matrix.bench_opts }}
+        working-directory: ruby-bench
+        env:
+          BUNDLER_VERSION: 0
+
       - uses: ./.github/actions/slack
         with:
-          label: ${{ matrix.test_task }} ${{ matrix.configure }}${{ matrix.arch }}
+          label: ruby-bench ${{ matrix.bench_opts }} ${{ matrix.ruby_opts }}
           SLACK_WEBHOOK_URL: ${{ secrets.SIMPLER_ALERTS_URL }} # ruby-lang slack: ruby/simpler-alerts-bot
         if: ${{ failure() }}
 
@@ -124,6 +267,7 @@ jobs:
     needs: [make]
     steps:
       - run: exit 1
+        working-directory:
         if: ${{ contains(needs.*.result, 'failure') || contains(needs.*.result, 'cancelled') }}
 
 defaults:
diff --git a/.github/workflows/wasm.yml b/.github/workflows/wasm.yml
index 956a00840d..f0263de5ef 100644
--- a/.github/workflows/wasm.yml
+++ b/.github/workflows/wasm.yml
@@ -3,24 +3,20 @@ on:
   push:
     paths-ignore:
       - 'doc/**'
-      - '**/man'
+      - '**/man/*'
       - '**.md'
       - '**.rdoc'
       - '**/.document'
+      - '.*.yml'
   pull_request:
     paths-ignore:
       - 'doc/**'
-      - '**/man'
+      - '**/man/*'
       - '**.md'
       - '**.rdoc'
       - '**/.document'
+      - '.*.yml'
   merge_group:
-    paths-ignore:
-      - 'doc/**'
-      - '**/man'
-      - '**.md'
-      - '**.rdoc'
-      - '**/.document'
 
 concurrency:
   group: ${{ github.workflow }} / ${{ startsWith(github.event_name, 'pull') && github.ref_name || github.sha }}
@@ -47,26 +43,32 @@ jobs:
     env:
       RUBY_TESTOPTS: '-q --tty=no'
       GITPULLOPTIONS: --no-tags origin ${{ github.ref }}
-      WASI_SDK_VERSION_MAJOR: 14
+      WASI_SDK_VERSION_MAJOR: 25
       WASI_SDK_VERSION_MINOR: 0
-      BINARYEN_VERSION: 109
-      WASMTIME_VERSION: v0.33.0
+      BINARYEN_VERSION: 113
+      WASMTIME_VERSION: v15.0.0
 
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-22.04
 
     if: >-
       ${{!(false
       || contains(github.event.head_commit.message, '[DOC]')
       || contains(github.event.pull_request.title, '[DOC]')
       || contains(github.event.pull_request.labels.*.name, 'Documentation')
-      || (github.event_name == 'push' && github.actor == 'dependabot[bot]')
+      || (github.event.pull_request.user.login == 'dependabot[bot]')
       )}}
 
     steps:
-      - uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4.1.1
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
         with:
           sparse-checkout-cone-mode: false
           sparse-checkout: /.github
+          persist-credentials: false
+
+      - uses: ruby/setup-ruby@afeafc3d1ab54a631816aba4c914a0081c12ff2f # v1.310.0
+        with:
+          ruby-version: '3.1'
+          bundler: none
 
       - uses: ./.github/actions/setup/directories
         with:
@@ -80,7 +82,7 @@ jobs:
           sudo apt-get update -q || :
           sudo apt-get install --no-install-recommends -q -y ruby make autoconf git wget
 
-          wasi_sdk_deb="wasi-sdk_${WASI_SDK_VERSION_MAJOR}.${WASI_SDK_VERSION_MINOR}_amd64.deb"
+          wasi_sdk_deb="wasi-sdk-${WASI_SDK_VERSION_MAJOR}.${WASI_SDK_VERSION_MINOR}-x86_64-linux.deb"
           wget "https://github.com/WebAssembly/wasi-sdk/releases/download/wasi-sdk-${WASI_SDK_VERSION_MAJOR}/${wasi_sdk_deb}"
           sudo dpkg -i "$wasi_sdk_deb"
           rm -f "$wasi_sdk_deb"
@@ -102,22 +104,66 @@ jobs:
         run: |
           echo "WASI_SDK_PATH=/opt/wasi-sdk" >> $GITHUB_ENV
 
-      - name: Run configure
+      - uses: ./.github/actions/setup/baseruby
+        id: baseruby
+        with:
+          srcdir: src
+
+      - name: Download config.guess with wasi version
         run: |
-          ../src/configure \
-            --host wasm32-unknown-wasi \
-            --with-static-linked-ext \
-            LDFLAGS=" \
-              -Xlinker --stack-first \
-              -Xlinker -z -Xlinker stack-size=16777216 \
-            " \
-            optflags="${{ matrix.entry.optflags }}" \
-            debugflags="${{ matrix.entry.debugflags }}" \
-            wasmoptflags="${{ matrix.entry.wasmoptflags }} ${{ matrix.entry.debugflags }}"
+          rm tool/config.guess tool/config.sub
+          ruby tool/downloader.rb -d tool -e gnu config.guess config.sub
+        working-directory: src
+
+      - name: Run configure
+        run: >-
+          ../src/configure
+          --host wasm32-unknown-wasi
+          --with-baseruby="${{ steps.baseruby.outputs.ruby }}"
+          --with-dump-ast="${{ steps.baseruby.outputs.dump_ast }}"
+          --with-static-linked-ext
+          --with-ext=${EXTS// /,}
+          LDFLAGS="
+          -Xlinker --stack-first
+          -Xlinker -z -Xlinker stack-size=16777216
+          "
+          optflags="${{ matrix.entry.optflags }}"
+          debugflags="${{ matrix.entry.debugflags }}"
+          wasmoptflags="${{ matrix.entry.wasmoptflags }} ${{ matrix.entry.debugflags }}"
+        env:
+          EXTS:
+            cgi/escape
+            continuation
+            coverage
+            date
+            digest
+            digest/*
+            erb/escape
+            etc
+            fcntl
+            json
+            json/*
+            objspace
+            rbconfig/sizeof
+            ripper
+            stringio
+            strscan
 
       # miniruby may not be built when cross-compling
       - run: make mini ruby
 
+      - run: make install DESTDIR=$PWD/../install
+      - run: tar cfz ../install.tar.gz -C ../install .
+
+      - name: Upload artifacts
+        uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7.0.1
+        with:
+          name: ruby-wasm-install
+          path: ${{ github.workspace }}/install.tar.gz
+      - name: Show Playground URL to try the build
+        run: |
+          echo "Try on Playground: https://ruby.github.io/play-ruby?run=$GITHUB_RUN_ID" >> $GITHUB_STEP_SUMMARY
+
       - name: Run basictest
         run: wasmtime run ./../build/miniruby --mapdir /::./ -- basictest/test.rb
         working-directory: src
@@ -134,6 +180,16 @@ jobs:
           SLACK_WEBHOOK_URL: ${{ secrets.SIMPLER_ALERTS_URL }} # ruby-lang slack: ruby/simpler-alerts-bot
         if: ${{ failure() }}
 
+      # Workaround for https://github.com/orgs/community/discussions/25220
+      - name: Save Pull Request number
+        if: ${{ github.event_name == 'pull_request' }}
+        run: echo "${{ github.event.pull_request.number }}" >> ${{ github.workspace }}/github-pr-info.txt
+      - uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7.0.1
+        if: ${{ github.event_name == 'pull_request' }}
+        with:
+          name: github-pr-info
+          path: ${{ github.workspace }}/github-pr-info.txt
+
 defaults:
   run:
     working-directory: build
diff --git a/.github/workflows/windows.yml b/.github/workflows/windows.yml
index 982f855345..03e75ad445 100644
--- a/.github/workflows/windows.yml
+++ b/.github/workflows/windows.yml
@@ -3,24 +3,15 @@ on:
   push:
     paths-ignore:
       - 'doc/**'
-      - '**/man'
+      - '**/man/*'
       - '**.md'
       - '**.rdoc'
       - '**/.document'
+      - '.*.yml'
   pull_request:
-    paths-ignore:
-      - 'doc/**'
-      - '**/man'
-      - '**.md'
-      - '**.rdoc'
-      - '**/.document'
+    # Do not use paths-ignore for required status checks
+    # https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/collaborating-on-repositories-with-code-quality-features/troubleshooting-required-status-checks#handling-skipped-but-required-checks
   merge_group:
-    paths-ignore:
-      - 'doc/**'
-      - '**/man'
-      - '**.md'
-      - '**.rdoc'
-      - '**/.document'
 
 concurrency:
   group: ${{ github.workflow }} / ${{ startsWith(github.event_name, 'pull') && github.ref_name || github.sha }}
@@ -34,164 +25,192 @@ jobs:
     strategy:
       matrix:
         include:
-          - vs: 2019
-          - vs: 2022
+          - os: 2022
+            test_task: check
+          - os: 2022
+            test_task: test-bundled-gems
+          - os: 2025-vs2026
+            test_task: check
+          - os: 2025-vs2026
+            test_task: test-bundled-gems
+          - os: 11-arm
+            test_task: 'btest test-basic test-tool' # check and test-spec are broken yet.
+            target: arm64
       fail-fast: false
 
-    runs-on: windows-${{ matrix.vs < 2022 && '2019' || matrix.vs }}
+    runs-on: windows-${{ matrix.os }}
 
     if: >-
       ${{!(false
       || contains(github.event.head_commit.message, '[DOC]')
       || contains(github.event.pull_request.title, '[DOC]')
       || contains(github.event.pull_request.labels.*.name, 'Documentation')
-      || (github.event_name == 'push' && github.actor == 'dependabot[bot]')
+      || (github.event.pull_request.user.login == 'dependabot[bot]' && !startsWith(github.head_ref, 'dependabot/vcpkg'))
       )}}
 
-    name: VisualStudio ${{ matrix.vs }}
+    name: Windows ${{ matrix.os }} (${{ matrix.test_task }})
 
     env:
       GITPULLOPTIONS: --no-tags origin ${{ github.ref }}
-      OS_VER: windows-${{ matrix.vs < 2022 && '2019' || matrix.vs }}
-      # FIXME: This is a workaround for the vcpkg's issue present as of openssl 3.1.1
-      # where OpenSSL's default modules directory is incorrectly set to C:\vcpkg\packages\openssl_x64-windows\bin
-      # cf. https://github.com/ruby/openssl/pull/635#issuecomment-1596833720
-      OPENSSL_MODULES: C:\vcpkg\installed\x64-windows\bin
+      VCPKG_DEFAULT_TRIPLET: ${{ matrix.target || 'x64' }}-windows
 
     steps:
       - run: md build
         working-directory:
 
-      - name: find tools
-        id: find-tools
-        run: |
-          ::- find needed tools
-          set NEEDS=
-          for %%I in (%NEEDED_TOOLS%) do if "%%~$PATH:I" == "" (
-            call set NEEDS=%%NEEDS%% %%~nI
-          ) else (
-            echo %%I: %%~$PATH:I
-          )
-          echo.needs=%NEEDS%>>%GITHUB_OUTPUT%
-          if "%NEEDS%" == "" (
-            echo [debug] All needed tools found
-          ) else (
-            echo [warning^]Needs%NEEDS%
-          )
-        env:
-          NEEDED_TOOLS: >-
-            patch.exe
-
-      - uses: msys2/setup-msys2@d40200dc2db4c351366b048a9565ad82919e1c24 # v2
-        id: setup-msys2
+      - uses: ruby/setup-ruby@afeafc3d1ab54a631816aba4c914a0081c12ff2f # v1.310.0
         with:
-          update: true
-          install: >-
-            ${{ steps.find-tools.outputs.needs }}
-        if: ${{ steps.find-tools.outputs.needs != '' }}
+          # windows-11-arm has only 3.4.1, 3.4.2, 3.4.3, head
+          ruby-version: ${{ !endsWith(matrix.os, 'arm') && '3.1' || '3.4' }}
+          bundler: none
+          windows-toolchain: none
 
-      - uses: actions/cache@704facf57e6136b1bc63b828d79edcd491f0ee84 # v3.3.2
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
         with:
-          path: C:\vcpkg\downloads
-          key: ${{ runner.os }}-vcpkg-download-${{ env.OS_VER }}-${{ github.sha }}
-          restore-keys: |
-            ${{ runner.os }}-vcpkg-download-${{ env.OS_VER }}-
-            ${{ runner.os }}-vcpkg-download-
+          persist-credentials: false
+          sparse-checkout-cone-mode: false
+          sparse-checkout: /.github
 
-      - uses: actions/cache@704facf57e6136b1bc63b828d79edcd491f0ee84 # v3.3.2
+      - uses: ./.github/actions/setup/directories
         with:
-          path: C:\vcpkg\installed
-          key: ${{ runner.os }}-vcpkg-installed-${{ env.OS_VER }}-${{ github.sha }}
-          restore-keys: |
-            ${{ runner.os }}-vcpkg-installed-${{ env.OS_VER }}-
-            ${{ runner.os }}-vcpkg-installed-
-
-      - name: Install libraries with vcpkg
-        run: |
-          vcpkg --triplet x64-windows install libffi libyaml openssl readline zlib
+          srcdir: src
+          builddir: build
+          make-command: nmake
+          clean: true
 
-      - name: Install libraries with scoop
+      - name: Install tools with scoop
         run: |
-          iex "& {$(irm get.scoop.sh)} -RunAsAdmin"
+          if ((vcpkg.exe help install) -match "manifest") { exit }
+          Set-ExecutionPolicy -ExecutionPolicy RemoteSigned -Scope CurrentUser
+          iwr -useb get.scoop.sh | iex
           Join-Path (Resolve-Path ~).Path "scoop\shims" >> $Env:GITHUB_PATH
+          scoop install vcpkg
         shell: pwsh
 
-      - uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4.1.1
+      - name: Restore vcpkg artifact
+        id: restore-vcpkg
+        uses: actions/cache/restore@27d5ce7f107fe9357f9df03efb73ab90386fccae # v5.0.5
         with:
-          sparse-checkout-cone-mode: false
-          sparse-checkout: /.github
+          path: src\vcpkg_installed
+          key: windows-${{ matrix.os }}-vcpkg-${{ hashFiles('src/vcpkg.json') }}
 
-      - uses: ./.github/actions/setup/directories
+      - name: Install libraries with vcpkg
+        id: build-vcpkg
+        run: |
+          git -C "%VCPKG_INSTALLATION_ROOT%" pull --quiet
+          vcpkg install
+        working-directory: src
+        if: ${{ ! steps.restore-vcpkg.outputs.cache-hit }}
+
+      - name: Save vcpkg artifact
+        uses: actions/cache/save@27d5ce7f107fe9357f9df03efb73ab90386fccae # v5.0.5
         with:
-          srcdir: src
-          builddir: build
+          path: src\vcpkg_installed
+          key: windows-${{ matrix.os }}-vcpkg-${{ hashFiles('src/vcpkg.json') }}
+        if: >-
+          steps.build-vcpkg.outcome == 'success' &&
+          (  github.ref_name == 'master'
+          || startsWith(github.ref_name, 'ruby_')
+          || ( github.event.pull_request.user.login == 'dependabot[bot]'
+          &&   startsWith(github.head_ref || github.ref_name, 'dependabot/vcpkg'))
+          )
 
       - name: setup env
+        # Available Ruby versions: https://github.com/actions/runner-images/blob/main/images/windows/Windows2019-Readme.md#ruby
         # %TEMP% is inconsistent with %TMP% and test-all expects they are consistent.
         # https://github.com/actions/virtual-environments/issues/712#issuecomment-613004302
         run: |
-          set VS=${{ matrix.vs }}
-          set VCVARS=${{ matrix.vcvars || '' }}
-          if not "%VCVARS%" == "" goto :vcset
-            set VCVARS="C:\Program Files (x86)\Microsoft Visual Studio\%VS%\Enterprise\VC\Auxiliary\Build\vcvars64.bat"
-            if not exist %VCVARS% set VCVARS="C:\Program Files\Microsoft Visual Studio\%VS%\Enterprise\VC\Auxiliary\Build\vcvars64.bat"
-          :vcset
-          set | C:\msys64\usr\bin\sort > old.env
-          call %VCVARS%
+          set > old.env
+          call ..\src\win32\vssetup.cmd ^
+            -arch=${{ matrix.target || 'amd64' }} ^
+            ${{ matrix.vcvars && '-vcvars_ver=' || '' }}${{ matrix.vcvars }}
           nmake -f nul
-          set TMP=%USERPROFILE%\AppData\Local\Temp
-          set TEMP=%USERPROFILE%\AppData\Local\Temp
+          set TMP=%RUNNER_TEMP%
+          set TEMP=%RUNNER_TEMP%
           set MAKEFLAGS=l
           set /a TEST_JOBS=(15 * %NUMBER_OF_PROCESSORS% / 10) > nul
-          set | C:\msys64\usr\bin\sort > new.env
-          C:\msys64\usr\bin\comm -13 old.env new.env >> %GITHUB_ENV%
+          set RUBY_OPT_DIR=%GITHUB_WORKSPACE:\=/%/src/vcpkg_installed/%VCPKG_DEFAULT_TRIPLET%
+          set > new.env
+
+      - name: update env
+        shell: pwsh
+        run: |
+          $old = (Get-Content old.env); $new = (Get-Content new.env)
           del *.env
+          Compare-Object $old $new |
+            Where-Object { $_.SideIndicator -eq '=>' } |
+            Select-Object -ExpandProperty InputObject |
+            Add-Content -Path $env:GITHUB_ENV
+
+      - name: baseruby version
+        run: ruby -v
 
       - name: compiler version
         run: cl
 
-      - name: link libraries
-        run: |
-          for %%I in (C:\vcpkg\installed\x64-windows\bin\*.dll) do (
-            if not %%~nI == readline mklink %%~nxI %%I
-          )
-      # We use OpenSSL instealled by vcpkg instead
-      - name: disable system OpenSSL
-        run: |
-          for %%I in (libcrypto-1_1-x64 libssl-1_1-x64) do (
-            ren c:\Windows\System32\%%I.dll %%I.dll_
-          )
-        # windows-2019 image doesn't have OpenSSL as of 2023/9/14
-        if: ${{ matrix.vs != 2019 }}
+      - name: volume info
+        run: Get-Volume
+        shell: pwsh
 
+      # TODO: We should use `../src` instead of `D:/a/ruby/ruby/src`
       - name: Configure
         run: >-
           ../src/win32/configure.bat --disable-install-doc
-          --with-opt-dir=C:/vcpkg/installed/x64-windows
+          --with-opt-dir=%RUBY_OPT_DIR%
+          --with-gmp
+
+      - run: nmake prepare-vcpkg
 
       - run: nmake incs
 
       - run: nmake extract-extlibs
 
-      - run: nmake
+      # On all other platforms, test-spec depending on extract-gems (in common.mk) is enough.
+      # But not for this Visual Studio workflow. So here we extract gems before building.
+      - run: nmake extract-gems
 
-      - run: nmake test
-        timeout-minutes: 5
+      # windows-11-arm runner cannot run `ruby tool/file2lastrev.rb --revision.h --output=revision.h`
+      - name: make revision.h
+        run: |
+          win32\lastrev.bat | win32\ifchange.bat --timestamp=.revision.time revision.h -
+          type revision.h
+        working-directory: src
 
-      - run: nmake test-spec
-        timeout-minutes: 10
+      - run: nmake
 
-      - run: nmake test-all
+      - name: Set up Launchable
+        uses: ./.github/actions/launchable/setup
+        with:
+          os: windows-${{ matrix.os }}
+          launchable-token: ${{ secrets.LAUNCHABLE_TOKEN }}
+          builddir: build
+          srcdir: src
+          test-task: ${{ matrix.test_task || 'check' }}
+        continue-on-error: true
+        if: ${{ matrix.test_task != 'test-bundled-gems' }}
+        timeout-minutes: 3
+
+      - run: nmake ${{ matrix.test_task || 'check' }}
         env:
-          RUBY_TESTOPTS: -j${{ env.TEST_JOBS || 4 }} --job-status=normal
-        timeout-minutes: 60
+          RUBY_TESTOPTS: -j${{ env.TEST_JOBS || 4 }}
+        timeout-minutes: 70
 
       - uses: ./.github/actions/slack
         with:
-          label: VS${{ matrix.vs }} / ${{ matrix.test_task || 'check' }}
+          label: Windows ${{ matrix.os }} / ${{ matrix.test_task || 'check' }}
           SLACK_WEBHOOK_URL: ${{ secrets.SIMPLER_ALERTS_URL }} # ruby-lang slack: ruby/simpler-alerts-bot
         if: ${{ failure() }}
 
+  result:
+    if: ${{ always() }}
+    name: ${{ github.workflow }} result
+    runs-on: windows-2025-vs2026
+    needs: [make]
+    steps:
+      - run: exit 1
+        working-directory:
+        if: ${{ contains(needs.*.result, 'failure') || contains(needs.*.result, 'cancelled') }}
+
 defaults:
   run:
     working-directory: build
diff --git a/.github/workflows/wsl.yml b/.github/workflows/wsl.yml
new file mode 100644
index 0000000000..470b68fe66
--- /dev/null
+++ b/.github/workflows/wsl.yml
@@ -0,0 +1,73 @@
+name: Ubuntu on WSL
+
+on:
+  push:
+    paths-ignore:
+      - 'doc/**'
+      - '**/man/*'
+      - '**.md'
+      - '**.rdoc'
+      - '**/.document'
+      - '.*.yml'
+  pull_request:
+    # Do not use paths-ignore for required status checks
+    # https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/collaborating-on-repositories-with-code-quality-features/troubleshooting-required-status-checks#handling-skipped-but-required-checks
+  merge_group:
+
+permissions:
+  contents: read
+
+jobs:
+  wsl:
+    runs-on: windows-2025-vs2026
+
+    if: >-
+      ${{!(false
+      || contains(github.event.head_commit.message, '[DOC]')
+      || contains(github.event.pull_request.title, '[DOC]')
+      || contains(github.event.pull_request.labels.*.name, 'Documentation')
+      || (github.event.pull_request.user.login == 'dependabot[bot]')
+      )}}
+
+    steps:
+      - name: Install or update WSL
+        uses: Ubuntu/WSL/.github/actions/wsl-install@main
+        with:
+          distro: Ubuntu-24.04
+
+      - name: Install dependencies
+        uses: Ubuntu/WSL/.github/actions/wsl-bash@main
+        with:
+         distro: Ubuntu-24.04
+         working-dir: /tmp/github/
+         exec: |
+            DEBIAN_FRONTEND=noninteractive sudo apt update
+            DEBIAN_FRONTEND=noninteractive sudo apt install -y ruby build-essential autoconf libssl-dev libyaml-dev zlib1g-dev libgmp-dev libffi-dev
+
+      - name: Check out the repository
+        uses: Ubuntu/WSL/.github/actions/wsl-checkout@main
+        with:
+          distro: Ubuntu-24.04
+          working-dir: /tmp/github/
+          submodules: true
+
+      - name: Build
+        uses: Ubuntu/WSL/.github/actions/wsl-bash@main
+        with:
+         distro: Ubuntu-24.04
+         working-dir: /tmp/github/
+         exec: |
+            ./autogen.sh
+            ./configure --disable-install-doc
+            make ruby -j4
+            make extract-gems
+            make -j4
+
+      - name: Test
+        uses: Ubuntu/WSL/.github/actions/wsl-bash@main
+        with:
+         distro: Ubuntu-24.04
+         working-dir: /tmp/github/
+         exec: |
+            ./ruby -v
+            # make check TESTS="-j4" MSPECOPT="-j"
diff --git a/.github/workflows/yjit-macos.yml b/.github/workflows/yjit-macos.yml
index 2681ae15b8..e11de6bc51 100644
--- a/.github/workflows/yjit-macos.yml
+++ b/.github/workflows/yjit-macos.yml
@@ -1,22 +1,23 @@
-name: YJIT macOS Arm64
+name: YJIT macOS
 on:
   push:
+    branches:
+      - master
     paths-ignore:
       - 'doc/**'
-      - '**/man'
+      - '**/man/*'
       - '**.md'
       - '**.rdoc'
       - '**/.document'
+      - '.*.yml'
   pull_request:
+    types:
+      - opened
+      - synchronize
+      - reopened
     # Do not use paths-ignore for required status checks
     # https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/collaborating-on-repositories-with-code-quality-features/troubleshooting-required-status-checks#handling-skipped-but-required-checks
   merge_group:
-    paths-ignore:
-      - 'doc/**'
-      - '**/man'
-      - '**.md'
-      - '**.rdoc'
-      - '**/.document'
 
 concurrency:
   group: ${{ github.workflow }} / ${{ startsWith(github.event_name, 'pull') && github.ref_name || github.sha }}
@@ -29,19 +30,20 @@ jobs:
   cargo:
     name: cargo test
 
-    runs-on: macos-arm-oss
+    runs-on: macos-26
 
     if: >-
-      ${{github.repository == 'ruby/ruby' &&
-      !(false
+      ${{!(false
       || contains(github.event.head_commit.message, '[DOC]')
       || contains(github.event.pull_request.title, '[DOC]')
       || contains(github.event.pull_request.labels.*.name, 'Documentation')
-      || (github.event_name == 'push' && github.actor == 'dependabot[bot]')
+      || (github.event.pull_request.user.login == 'dependabot[bot]' && !startsWith(github.head_ref, 'dependabot/cargo'))
       )}}
 
     steps:
-      - uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4.1.1
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with:
+          persist-credentials: false
 
       - run: RUST_BACKTRACE=1 cargo test
         working-directory: yjit
@@ -63,29 +65,31 @@ jobs:
             yjit_opts: '--yjit'
           - test_task: 'check'
             configure: '--enable-yjit=dev'
-            yjit_opts: '--yjit-call-threshold=1 --yjit-verify-ctx'
+            yjit_opts: '--yjit-call-threshold=1 --yjit-verify-ctx --yjit-code-gc'
+            specopts: '-T --yjit-call-threshold=1 -T --yjit-verify-ctx -T --yjit-code-gc'
       fail-fast: false
 
     env:
       GITPULLOPTIONS: --no-tags origin ${{ github.ref }}
       RUN_OPTS: ${{ matrix.yjit_opts }}
+      SPECOPTS: ${{ matrix.specopts }}
 
-    runs-on: macos-arm-oss
+    runs-on: macos-26
 
     if: >-
-      ${{github.repository == 'ruby/ruby' &&
-      !(false
+      ${{!(false
       || contains(github.event.head_commit.message, '[DOC]')
       || contains(github.event.pull_request.title, '[DOC]')
       || contains(github.event.pull_request.labels.*.name, 'Documentation')
-      || (github.event_name == 'push' && github.actor == 'dependabot[bot]')
+      || (github.event.pull_request.user.login == 'dependabot[bot]' && !startsWith(github.head_ref, 'dependabot/cargo'))
       )}}
 
     steps:
-      - uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4.1.1
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
         with:
           sparse-checkout-cone-mode: false
           sparse-checkout: /.github
+          persist-credentials: false
 
       - name: Install libraries
         uses: ./.github/actions/setup/macos
@@ -96,6 +100,8 @@ jobs:
           builddir: build
           makeup: true
           dummy-files: ${{ matrix.test_task == 'check' }}
+          # Set fetch-depth: 10 so that Launchable can receive commits information.
+          fetch-depth: 10
 
       - name: Run configure
         run: ../src/configure -C --disable-install-doc ${{ matrix.configure }}
@@ -105,30 +111,74 @@ jobs:
 
       - run: make
 
-      - name: Enable YJIT through ENV
-        run: echo "RUBY_YJIT_ENABLE=1" >> $GITHUB_ENV
+      - name: Verify that --yjit-dump-disasm works
+        run: |
+          ./miniruby --yjit-call-threshold=1 --yjit-dump-disasm -e0 | \
+          wc -l | \
+          ruby -ne 'raise "Disassembly seems broken in dev build (output has too few lines)" unless $_.to_i > 10'
+        if: ${{ contains(matrix.configure, 'jit=dev') }}
+
+      - name: Set ENV for YJIT
+        run: |
+          echo "RUBY_YJIT_ENABLE=1" >> $GITHUB_ENV
+          echo "RUBY_CRASH_REPORT=$(pwd)/rb_crash_%p.txt" >> $GITHUB_ENV
+
+      - name: Set test options for skipped tests
+        run: |
+          set -x
+          TESTS="$(echo "${{ matrix.skipped_tests }}" | sed 's| |$$/ -n!/|g;s|^|-n!/|;s|$|$$/|')"
+          echo "TESTS=${TESTS}" >> $GITHUB_ENV
+        if: ${{ matrix.test_task == 'check' && matrix.skipped_tests }}
+
+      - name: Set up Launchable
+        id: launchable
+        uses: ./.github/actions/launchable/setup
+        with:
+          os: macos-26
+          test-opts: ${{ matrix.configure }}
+          launchable-token: ${{ secrets.LAUNCHABLE_TOKEN }}
+          builddir: build
+          srcdir: src
+          is-yjit: true
+        continue-on-error: true
+        timeout-minutes: 3
 
       - name: make ${{ matrix.test_task }}
         run: |
-          make -s ${{ matrix.test_task }} ${TESTS:+TESTS=`echo "$TESTS" | sed 's| |$$/ -n!/|g;s|^|-n!/|;s|$|$$/|'`}
+          test -n "${LAUNCHABLE_STDOUT}" && exec 1> >(tee "${LAUNCHABLE_STDOUT}")
+          test -n "${LAUNCHABLE_STDERR}" && exec 2> >(tee "${LAUNCHABLE_STDERR}")
+
+          set -x
+          make -s ${{ matrix.test_task }} ${TESTS:+TESTS="$TESTS"} \
+            RUN_OPTS="$RUN_OPTS" \
+            SPECOPTS="$SPECOPTS"
         timeout-minutes: 60
         env:
           RUBY_TESTOPTS: '-q --tty=no'
-          TESTS: ${{ matrix.test_task == 'check' && matrix.skipped_tests || '' }}
           TEST_BUNDLED_GEMS_ALLOW_FAILURES: ''
+          SYNTAX_SUGGEST_TIMEOUT: '5'
           PRECHECK_BUNDLED_GEMS: 'no'
+          LAUNCHABLE_STDOUT: ${{ steps.launchable.outputs.stdout_report_path }}
+          LAUNCHABLE_STDERR: ${{ steps.launchable.outputs.stderr_report_path }}
+        continue-on-error: ${{ matrix.continue-on-test_task || false }}
 
       - name: make skipped tests
         run: |
-          make -s test-all TESTS=`echo "$TESTS" | sed 's| |$$/ -n/|g;s|^|-n/|;s|$|$$/|'`
+          make -s test-all TESTS="${TESTS//-n!\//-n/}"
         env:
           GNUMAKEFLAGS: ''
           RUBY_TESTOPTS: '-v --tty=no'
-          TESTS: ${{ matrix.skipped_tests }}
           PRECHECK_BUNDLED_GEMS: 'no'
-        if: ${{ matrix.test_task == 'check' && matrix.skipped_tests != '' }}
+        if: ${{ matrix.test_task == 'check' && matrix.skipped_tests }}
         continue-on-error: ${{ matrix.continue-on-skipped_tests || false }}
 
+      - name: Dump crash logs
+        if: ${{ failure() }}
+        continue-on-error: true
+        run: |
+          tail --verbose --lines=+1 rb_crash_*.txt
+          exit 1
+
       - uses: ./.github/actions/slack
         with:
           label: ${{ matrix.test_task }} ${{ matrix.configure }} ${{ matrix.yjit_opts }}
@@ -136,12 +186,14 @@ jobs:
         if: ${{ failure() }}
 
   result:
-    if: ${{ always() && github.repository == 'ruby/ruby' }}
+    if: ${{ always() }}
     name: ${{ github.workflow }} result
-    runs-on: macos-arm-oss
+    runs-on: ubuntu-latest
     needs: [make]
     steps:
-      - run: exit 1
+      - name: ${{ github.workflow }} jobs have failed
+        run: exit 1
+        working-directory:
         if: ${{ contains(needs.*.result, 'failure') || contains(needs.*.result, 'cancelled') }}
 
 defaults:
diff --git a/.github/workflows/yjit-ubuntu.yml b/.github/workflows/yjit-ubuntu.yml
index f6bcd2ac9a..ab816940f4 100644
--- a/.github/workflows/yjit-ubuntu.yml
+++ b/.github/workflows/yjit-ubuntu.yml
@@ -3,20 +3,15 @@ on:
   push:
     paths-ignore:
       - 'doc/**'
-      - '**/man'
+      - '**/man/*'
       - '**.md'
       - '**.rdoc'
       - '**/.document'
+      - '.*.yml'
   pull_request:
     # Do not use paths-ignore for required status checks
     # https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/collaborating-on-repositories-with-code-quality-features/troubleshooting-required-status-checks#handling-skipped-but-required-checks
   merge_group:
-    paths-ignore:
-      - 'doc/**'
-      - '**/man'
-      - '**.md'
-      - '**.rdoc'
-      - '**/.document'
 
 concurrency:
   group: ${{ github.workflow }} / ${{ startsWith(github.event_name, 'pull') && github.ref_name || github.sha }}
@@ -30,18 +25,20 @@ jobs:
     name: cargo test
 
     # GitHub Action's image seems to already contain a Rust 1.58.0.
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-22.04
 
     if: >-
       ${{!(false
       || contains(github.event.head_commit.message, '[DOC]')
       || contains(github.event.pull_request.title, '[DOC]')
       || contains(github.event.pull_request.labels.*.name, 'Documentation')
-      || (github.event_name == 'push' && github.actor == 'dependabot[bot]')
+      || (github.event.pull_request.user.login == 'dependabot[bot]' && !startsWith(github.head_ref, 'dependabot/cargo'))
       )}}
 
     steps:
-      - uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4.1.1
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with:
+          persist-credentials: false
 
       # For now we can't run cargo test --offline because it complains about the
       # capstone dependency, even though the dependency is optional
@@ -62,18 +59,20 @@ jobs:
     name: cargo clippy
 
     # GitHub Action's image seems to already contain a Rust 1.58.0.
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-22.04
 
     if: >-
       ${{!(false
       || contains(github.event.head_commit.message, '[DOC]')
       || contains(github.event.pull_request.title, '[DOC]')
       || contains(github.event.pull_request.labels.*.name, 'Documentation')
-      || (github.event_name == 'push' && github.actor == 'dependabot[bot]')
+      || (github.event.pull_request.user.login == 'dependabot[bot]' && !startsWith(github.head_ref, 'dependabot/cargo'))
       )}}
 
     steps:
-      - uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4.1.1
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with:
+          persist-credentials: false
 
       # Check that we don't have linting errors in release mode, too
       - run: cargo clippy --all-targets --all-features
@@ -86,7 +85,9 @@ jobs:
         include:
           - test_task: 'yjit-bindgen'
             hint: 'To fix: use patch in logs'
-            configure: '--with-gcc=clang-12 --enable-yjit=dev'
+            # Build with YJIT+ZJIT for output that works in the most number of configurations
+            configure: '--with-gcc=clang-14 --enable-yjit=dev --enable-zjit'
+            libclang_path: '/usr/lib/llvm-14/lib/libclang.so.1'
 
           - test_task: 'check'
             # YJIT should be automatically built in release mode on x86-64 Linux with rustc present
@@ -99,52 +100,63 @@ jobs:
 
           - test_task: 'check'
             configure: '--enable-yjit=dev'
-            yjit_opts: '--yjit-call-threshold=1 --yjit-verify-ctx'
+            yjit_opts: '--yjit-call-threshold=1 --yjit-verify-ctx --yjit-code-gc'
+            specopts: '-T --yjit-call-threshold=1 -T --yjit-verify-ctx -T --yjit-code-gc'
 
           - test_task: 'test-bundled-gems'
             configure: '--enable-yjit=dev'
 
-          - test_task: 'yjit-bench'
-            configure: '--enable-yjit=dev'
-            yjit_bench_opts: '--yjit-stats'
-
     env:
       GITPULLOPTIONS: --no-tags origin ${{ github.ref }}
       RUN_OPTS: ${{ matrix.yjit_opts }}
       YJIT_BENCH_OPTS: ${{ matrix.yjit_bench_opts }}
+      SPECOPTS: ${{ matrix.specopts }}
       RUBY_DEBUG: ci
-      BUNDLE_JOBS: 8 # for yjit-bench
       RUST_BACKTRACE: 1
 
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-22.04
 
     if: >-
       ${{!(false
       || contains(github.event.head_commit.message, '[DOC]')
       || contains(github.event.pull_request.title, '[DOC]')
       || contains(github.event.pull_request.labels.*.name, 'Documentation')
-      || (github.event_name == 'push' && github.actor == 'dependabot[bot]')
+      || (github.event.pull_request.user.login == 'dependabot[bot]' && !startsWith(github.head_ref, 'dependabot/cargo'))
       )}}
 
     steps:
-      - uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4.1.1
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
         with:
           sparse-checkout-cone-mode: false
           sparse-checkout: /.github
+          persist-credentials: false
 
       - uses: ./.github/actions/setup/ubuntu
 
+      - uses: ruby/setup-ruby@afeafc3d1ab54a631816aba4c914a0081c12ff2f # v1.310.0
+        with:
+          ruby-version: '3.1'
+          bundler: none
+
       - uses: ./.github/actions/setup/directories
         with:
           srcdir: src
           builddir: build
           makeup: true
           dummy-files: ${{ matrix.test_task == 'check' }}
+          # Set fetch-depth: 10 so that Launchable can receive commits information.
+          fetch-depth: 10
 
       - name: Install Rust
         if: ${{ matrix.rust_version }}
         run: rustup install ${{ matrix.rust_version }} --profile minimal
 
+      - name: Remove cargo
+        # Since this tests a `rustc` build for release, remove `cargo` to ensure
+        # that only `rustc` is used.
+        if: ${{ contains(matrix.configure, 'rustc') }}
+        run: sudo rm $(which -a cargo | uniq)
+
       - name: Run configure
         run: ../src/configure -C --disable-install-doc --prefix=$(pwd)/install ${{ matrix.configure }}
 
@@ -155,30 +167,62 @@ jobs:
 
       - run: make
 
-      - name: Enable YJIT through ENV
-        run: echo "RUBY_YJIT_ENABLE=1" >> $GITHUB_ENV
+      - name: Verify that --yjit-dump-disasm works
+        run: |
+          ./miniruby --yjit-call-threshold=1 --yjit-dump-disasm -e0 | \
+          wc -l | \
+          ruby -ne 'raise "Disassembly seems broken in dev build (output has too few lines)" unless $_.to_i > 10'
+        if: ${{ contains(matrix.configure, 'jit=dev') }}
+
+      - name: Set ENV for YJIT
+        run: |
+          echo "RUBY_YJIT_ENABLE=1" >> $GITHUB_ENV
+          echo "RUBY_CRASH_REPORT=$(pwd)/rb_crash_%p.txt" >> $GITHUB_ENV
 
       # Check that the binary was built with YJIT
       - name: Check YJIT enabled
         run: ./miniruby --yjit -v | grep "+YJIT"
 
+      - name: Set up Launchable
+        id: launchable
+        uses: ./.github/actions/launchable/setup
+        with:
+          os: ubuntu-22.04
+          test-opts: ${{ matrix.configure }}
+          launchable-token: ${{ secrets.LAUNCHABLE_TOKEN }}
+          builddir: build
+          srcdir: src
+          is-yjit: true
+        continue-on-error: true
+        timeout-minutes: 3
+
       - name: make ${{ matrix.test_task }}
-        run: make -s -j ${{ matrix.test_task }} RUN_OPTS="$RUN_OPTS" MSPECOPT=--debug YJIT_BENCH_OPTS="$YJIT_BENCH_OPTS" YJIT_BINDGEN_DIFF_OPTS="$YJIT_BINDGEN_DIFF_OPTS"
-        timeout-minutes: 60
+        run: |
+          test -n "${LAUNCHABLE_STDOUT}" && exec 1> >(tee "${LAUNCHABLE_STDOUT}")
+          test -n "${LAUNCHABLE_STDERR}" && exec 2> >(tee "${LAUNCHABLE_STDERR}")
+
+          set -x
+          make -s ${{ matrix.test_task }} ${TESTS:+TESTS="$TESTS"} \
+            RUN_OPTS="$RUN_OPTS" MSPECOPT=--debug SPECOPTS="$SPECOPTS" \
+            YJIT_BENCH_OPTS="$YJIT_BENCH_OPTS" YJIT_BINDGEN_DIFF_OPTS="$YJIT_BINDGEN_DIFF_OPTS"
+        timeout-minutes: 90
         env:
           RUBY_TESTOPTS: '-q --tty=no'
-          TEST_BUNDLED_GEMS_ALLOW_FAILURES: 'rbs'
+          TEST_BUNDLED_GEMS_ALLOW_FAILURES: ''
           PRECHECK_BUNDLED_GEMS: 'no'
           SYNTAX_SUGGEST_TIMEOUT: '5'
           YJIT_BINDGEN_DIFF_OPTS: '--exit-code'
-        continue-on-error: ${{ matrix.test_task == 'yjit-bench' }}
+          LIBCLANG_PATH: ${{ matrix.libclang_path }}
+          LAUNCHABLE_STDOUT: ${{ steps.launchable.outputs.stdout_report_path }}
+          LAUNCHABLE_STDERR: ${{ steps.launchable.outputs.stderr_report_path }}
+        continue-on-error: ${{ matrix.continue-on-test_task || false }}
 
-      - name: Show ${{ github.event.pull_request.base.ref }} GitHub URL for yjit-bench comparison
-        run: echo "https://github.com/${BASE_REPO}/commit/${BASE_SHA}"
-        env:
-          BASE_REPO: ${{ github.event.pull_request.base.repo.full_name }}
-          BASE_SHA: ${{ github.event.pull_request.base.sha }}
-        if: ${{ matrix.test_task == 'yjit-bench' && startsWith(github.event_name, 'pull') }}
+      - name: Dump crash logs
+        if: ${{ failure() }}
+        continue-on-error: true
+        run: |
+          tail --verbose --lines=+1 rb_crash_*.txt
+          exit 1
 
       - uses: ./.github/actions/slack
         with:
@@ -193,6 +237,7 @@ jobs:
     needs: [make]
     steps:
       - run: exit 1
+        working-directory:
         if: ${{ contains(needs.*.result, 'failure') || contains(needs.*.result, 'cancelled') }}
 
 defaults:
diff --git a/.github/workflows/zjit-macos.yml b/.github/workflows/zjit-macos.yml
new file mode 100644
index 0000000000..707e50e36b
--- /dev/null
+++ b/.github/workflows/zjit-macos.yml
@@ -0,0 +1,239 @@
+name: ZJIT macOS
+on:
+  push:
+    branches:
+      - master
+    paths-ignore:
+      - 'doc/**'
+      - '**/man/*'
+      - '**.md'
+      - '**.rdoc'
+      - '**/.document'
+      - '.*.yml'
+  pull_request:
+    types:
+      - opened
+      - synchronize
+      - reopened
+    # Do not use paths-ignore for required status checks
+    # https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/collaborating-on-repositories-with-code-quality-features/troubleshooting-required-status-checks#handling-skipped-but-required-checks
+  merge_group:
+
+concurrency:
+  group: ${{ github.workflow }} / ${{ startsWith(github.event_name, 'pull') && github.ref_name || github.sha }}
+  cancel-in-progress: ${{ startsWith(github.event_name, 'pull') }}
+
+permissions:
+  contents: read
+
+jobs:
+  make:
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - test_task: 'check'
+            run_opts: '--zjit-call-threshold=1'
+            specopts: '-T --zjit-call-threshold=1'
+            configure: '--enable-zjit=dev'
+
+          - test_task: 'check'
+            run_opts: '--zjit-disable-hir-opt --zjit-call-threshold=1'
+            specopts: '-T --zjit-disable-hir-opt -T --zjit-call-threshold=1'
+            configure: '--enable-zjit=dev'
+
+          - test_task: 'zjit-check' # zjit-test + quick feedback of test_zjit.rb
+            configure: '--enable-yjit=dev --enable-zjit'
+            rust_version: "1.85.0"
+
+          - test_task: 'ruby'
+            hint: 'combo build test'
+            configure: '--enable-yjit --enable-zjit'
+
+    env:
+      GITPULLOPTIONS: --no-tags origin ${{ github.ref }}
+      RUN_OPTS: ${{ matrix.run_opts }}
+      SPECOPTS: ${{ matrix.specopts }}
+      TESTOPTS: ${{ matrix.testopts }}
+      RUST_BACKTRACE: 1
+      ZJIT_RB_BUG: 1
+
+    runs-on: macos-26
+
+    if: >-
+      ${{!(false
+      || contains(github.event.head_commit.message, '[DOC]')
+      || contains(github.event.pull_request.title, '[DOC]')
+      || contains(github.event.pull_request.labels.*.name, 'Documentation')
+      || (github.event.pull_request.user.login == 'dependabot[bot]' && !startsWith(github.head_ref, 'dependabot/cargo'))
+      )}}
+
+    steps:
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with:
+          sparse-checkout-cone-mode: false
+          sparse-checkout: /.github
+          persist-credentials: false
+
+      - name: Install libraries
+        uses: ./.github/actions/setup/macos
+
+      - uses: ./.github/actions/setup/directories
+        with:
+          srcdir: src
+          builddir: build
+          makeup: true
+          dummy-files: ${{ matrix.test_task == 'check' }}
+          # Set fetch-depth: 10 so that Launchable can receive commits information.
+          fetch-depth: 10
+
+      - name: Install Rust
+        if: ${{ matrix.rust_version }}
+        run: |
+          rustup install ${{ matrix.rust_version }} --profile minimal
+          rustup default ${{ matrix.rust_version }}
+
+      - uses: taiki-e/install-action@4bc351f7f2614e48088386e2a0ad917ca3a7e4ba # v2.81.5
+        with:
+          tool: nextest@0.9
+        if: ${{ matrix.test_task == 'zjit-check' }}
+
+      - name: Run configure
+        run: ../src/configure -C --disable-install-doc ${{ matrix.configure }}
+
+      - run: make
+
+      - name: Verify that --zjit-dump-disasm works
+        run: |
+          ./miniruby --zjit-call-threshold=1 --zjit-dump-disasm -e0 | \
+          wc -l | \
+          ruby -ne 'raise "Disassembly seems broken in dev build (output has too few lines)" unless $_.to_i > 10'
+        if: ${{ contains(matrix.configure, 'jit=dev') }}
+
+      - name: Set ENV for ZJIT
+        run: |
+          echo "RUBY_CRASH_REPORT=$(pwd)/rb_crash_%p.txt" >> $GITHUB_ENV
+
+      - name: Set up Launchable
+        id: launchable
+        uses: ./.github/actions/launchable/setup
+        with:
+          os: macos-26
+          test-opts: ${{ matrix.configure }}
+          launchable-token: ${{ secrets.LAUNCHABLE_TOKEN }}
+          builddir: build
+          srcdir: src
+          is-zjit: true
+        continue-on-error: true
+        timeout-minutes: 3
+
+      - name: make ${{ matrix.test_task }}
+        run: |
+          test -n "${LAUNCHABLE_STDOUT}" && exec 1> >(tee "${LAUNCHABLE_STDOUT}")
+          test -n "${LAUNCHABLE_STDERR}" && exec 2> >(tee "${LAUNCHABLE_STDERR}")
+
+          set -x
+          make -s ${{ matrix.test_task }} ${TESTS:+TESTS="$TESTS"} \
+            RUN_OPTS="$RUN_OPTS" \
+            SPECOPTS="$SPECOPTS" \
+            TESTOPTS="$TESTOPTS"
+        timeout-minutes: 60
+        env:
+          RUBY_TESTOPTS: '-q --tty=no'
+          EXCLUDES: '../src/test/.excludes-zjit'
+          TEST_BUNDLED_GEMS_ALLOW_FAILURES: ''
+          SYNTAX_SUGGEST_TIMEOUT: '30'
+          PRECHECK_BUNDLED_GEMS: 'no'
+          LAUNCHABLE_STDOUT: ${{ steps.launchable.outputs.stdout_report_path }}
+          LAUNCHABLE_STDERR: ${{ steps.launchable.outputs.stderr_report_path }}
+        continue-on-error: ${{ matrix.continue-on-test_task || false }}
+
+      - name: Dump crash logs
+        if: ${{ failure() }}
+        continue-on-error: true
+        run: |
+          tail --verbose --lines=+1 rb_crash_*.txt
+          exit 1
+
+      - uses: ./.github/actions/slack
+        with:
+          label: ${{ matrix.test_task }} ${{ matrix.configure }}
+          SLACK_WEBHOOK_URL: ${{ secrets.SIMPLER_ALERTS_URL }} # ruby-lang slack: ruby/simpler-alerts-bot
+        if: ${{ failure() }}
+
+  result:
+    if: ${{ always() }}
+    name: ${{ github.workflow }} result
+    runs-on: ubuntu-latest
+    needs: [make]
+    steps:
+      - run: exit 1
+        working-directory:
+        if: ${{ contains(needs.*.result, 'failure') || contains(needs.*.result, 'cancelled') }}
+
+  # Separated from `make` job to avoid making it a required status check for now
+  ruby-bench:
+    strategy:
+      matrix:
+        include:
+          # Test --call-threshold=2 with 2 iterations in total
+          - ruby_opts: '--zjit-call-threshold=2'
+            bench_opts: '--warmup=1 --bench=1 --excludes=shipit'
+            configure: '--enable-zjit=dev_nodebug' # --enable-zjit=dev is too slow
+
+    runs-on: macos-26
+
+    if: >-
+      ${{!(false
+      || contains(github.event.head_commit.message, '[DOC]')
+      || contains(github.event.pull_request.title, '[DOC]')
+      || contains(github.event.pull_request.labels.*.name, 'Documentation')
+      || (github.event.pull_request.user.login == 'dependabot[bot]' && !startsWith(github.head_ref, 'dependabot/cargo'))
+      )}}
+
+    steps:
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with:
+          persist-credentials: false
+
+      - uses: ./.github/actions/setup/macos
+
+      - uses: ./.github/actions/setup/directories
+        with:
+          srcdir: src
+          builddir: build
+          makeup: true
+
+      - name: Run configure
+        run: ../src/configure -C --disable-install-doc --prefix="$(pwd)/install" ${{ matrix.configure }}
+
+      - run: make install
+
+      # setup/directories set MAKEFLAGS=-j4 for macOS, which randomly fails sqlite3.gem builds
+      - name: Unset MAKEFLAGS
+        run: echo "MAKEFLAGS=" >> "$GITHUB_ENV"
+
+      - name: Checkout ruby-bench
+        uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with:
+          persist-credentials: false
+          repository: ruby/ruby-bench
+          path: ruby-bench
+
+      # If you want to skip failing benchmark, consider using `--excludes`.
+      # e.g. `bench_opts: '--warmup=1 --bench=1 --excludes=railsbench,lobsters'`
+      - name: Run ruby-bench
+        run: ruby run_benchmarks.rb -e "zjit::../build/install/bin/ruby ${{ matrix.ruby_opts }}" ${{ matrix.bench_opts }}
+        working-directory: ruby-bench
+        env:
+          BUNDLER_VERSION: 0
+
+      - uses: ./.github/actions/slack
+        with:
+          label: ruby-bench ${{ matrix.bench_opts }} ${{ matrix.ruby_opts }}
+          SLACK_WEBHOOK_URL: ${{ secrets.SIMPLER_ALERTS_URL }} # ruby-lang slack: ruby/simpler-alerts-bot
+        if: ${{ failure() }}
+
+defaults:
+  run:
+    working-directory: build
diff --git a/.github/workflows/zjit-ubuntu.yml b/.github/workflows/zjit-ubuntu.yml
new file mode 100644
index 0000000000..1c3e3f6531
--- /dev/null
+++ b/.github/workflows/zjit-ubuntu.yml
@@ -0,0 +1,293 @@
+name: ZJIT Ubuntu
+on:
+  push:
+    branches:
+      - master
+    paths-ignore:
+      - 'doc/**'
+      - '**/man/*'
+      - '**.md'
+      - '**.rdoc'
+      - '**/.document'
+      - '.*.yml'
+  pull_request:
+    types:
+      - opened
+      - synchronize
+      - reopened
+    # Do not use paths-ignore for required status checks
+    # https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/collaborating-on-repositories-with-code-quality-features/troubleshooting-required-status-checks#handling-skipped-but-required-checks
+  merge_group:
+
+concurrency:
+  group: ${{ github.workflow }} / ${{ startsWith(github.event_name, 'pull') && github.ref_name || github.sha }}
+  cancel-in-progress: ${{ startsWith(github.event_name, 'pull') }}
+
+permissions:
+  contents: read
+
+jobs:
+  lint:
+    name: cargo clippy
+
+    runs-on: ubuntu-22.04
+
+    if: >-
+      ${{!(false
+      || contains(github.event.head_commit.message, '[DOC]')
+      || contains(github.event.pull_request.title, '[DOC]')
+      || contains(github.event.pull_request.labels.*.name, 'Documentation')
+      || (github.event.pull_request.user.login == 'dependabot[bot]' && !startsWith(github.head_ref, 'dependabot/cargo'))
+      )}}
+
+    steps:
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with:
+          persist-credentials: false
+
+      - run: cargo clippy --all-targets --all-features
+        working-directory: zjit
+
+  make:
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - test_task: 'check'
+            run_opts: '--zjit-call-threshold=1'
+            specopts: '-T --zjit-call-threshold=1'
+            configure: '--enable-zjit=dev'
+
+          - test_task: 'check'
+            run_opts: '--zjit-disable-hir-opt --zjit-call-threshold=1'
+            specopts: '-T --zjit-disable-hir-opt -T --zjit-call-threshold=1'
+            configure: '--enable-zjit=dev'
+
+            # The optimizer benefits from at least 1 iteration of profiling. Also, many
+            # regression tests in bootstraptest/test_yjit.rb assume call-threshold=2.
+          - test_task: 'btest'
+            run_opts: '--zjit-call-threshold=2'
+            configure: '--enable-zjit=dev'
+
+          - test_task: 'zjit-check' # zjit-test + quick feedback of test_zjit.rb
+            configure: '--enable-yjit --enable-zjit=dev'
+            rust_version: '1.85.0'
+
+          - test_task: 'zjit-bindgen'
+            hint: 'To fix: use patch in logs'
+            # Build with YJIT+ZJIT for output that works in the most number of configurations
+            configure: '--enable-zjit=dev --enable-yjit --with-gcc=clang-16'
+            clang_path: '/usr/bin/clang-16'
+            runs-on: 'ubuntu-24.04' # for clang-16
+
+          - test_task: 'test-bundled-gems'
+            configure: '--enable-zjit=dev'
+            run_opts: '--zjit-call-threshold=1'
+
+    env:
+      GITPULLOPTIONS: --no-tags origin ${{ github.ref }}
+      RUN_OPTS: ${{ matrix.run_opts }}
+      YJIT_BENCH_OPTS: ${{ matrix.yjit_bench_opts }}
+      SPECOPTS: ${{ matrix.specopts }}
+      TESTOPTS: ${{ matrix.testopts }}
+      RUBY_DEBUG: ci
+      BUNDLE_JOBS: 8 # for yjit-bench
+      RUST_BACKTRACE: 1
+      ZJIT_RB_BUG: 1
+
+    runs-on: ${{ matrix.runs-on || 'ubuntu-22.04' }}
+
+    if: >-
+      ${{!(false
+      || contains(github.event.head_commit.message, '[DOC]')
+      || contains(github.event.pull_request.title, '[DOC]')
+      || contains(github.event.pull_request.labels.*.name, 'Documentation')
+      || (github.event.pull_request.user.login == 'dependabot[bot]' && !startsWith(github.head_ref, 'dependabot/cargo'))
+      )}}
+
+    steps:
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with:
+          sparse-checkout-cone-mode: false
+          sparse-checkout: /.github
+          persist-credentials: false
+
+      - uses: ./.github/actions/setup/ubuntu
+
+      - uses: ruby/setup-ruby@afeafc3d1ab54a631816aba4c914a0081c12ff2f # v1.310.0
+        with:
+          ruby-version: '3.1'
+          bundler: none
+
+      - uses: taiki-e/install-action@4bc351f7f2614e48088386e2a0ad917ca3a7e4ba # v2.81.5
+        with:
+          tool: nextest@0.9
+        if: ${{ matrix.test_task == 'zjit-check' }}
+
+      - uses: ./.github/actions/setup/directories
+        with:
+          srcdir: src
+          builddir: build
+          makeup: true
+          dummy-files: ${{ matrix.test_task == 'check' }}
+          # Set fetch-depth: 10 so that Launchable can receive commits information.
+          fetch-depth: 10
+
+      - name: Install Rust
+        if: ${{ matrix.rust_version }}
+        run: |
+          rustup install ${{ matrix.rust_version }} --profile minimal
+          rustup default ${{ matrix.rust_version }}
+
+      - name: Install rustfmt
+        if: ${{ matrix.test_task == 'zjit-bindgen' }}
+        run: rustup component add rustfmt
+
+      - name: Run configure
+        run: ../src/configure -C --disable-install-doc --prefix=$(pwd)/install ${{ matrix.configure }}
+
+      - run: make incs
+
+      - run: make prepare-gems
+        if: ${{ matrix.test_task == 'test-bundled-gems' }}
+
+      - run: make
+
+      - name: Verify that --zjit-dump-disasm works
+        run: |
+          ./miniruby --zjit-call-threshold=1 --zjit-dump-disasm -e0 | \
+          wc -l | \
+          ruby -ne 'raise "Disassembly seems broken in dev build (output has too few lines)" unless $_.to_i > 10'
+        if: ${{ contains(matrix.configure, 'jit=dev') }}
+
+      # Check that the binary was built with ZJIT
+      - name: Check ZJIT enabled
+        run: ./miniruby --zjit -v | grep "+ZJIT"
+        if: ${{ matrix.configure != '--disable-zjit' }}
+
+      - name: Set ENV for ZJIT
+        run: |
+          echo "RUBY_CRASH_REPORT=$(pwd)/rb_crash_%p.txt" >> $GITHUB_ENV
+
+      - name: Set up Launchable
+        id: launchable
+        uses: ./.github/actions/launchable/setup
+        with:
+          os: ${{ matrix.runs-on || 'ubuntu-22.04' }}
+          test-opts: ${{ matrix.configure }}
+          launchable-token: ${{ secrets.LAUNCHABLE_TOKEN }}
+          builddir: build
+          srcdir: src
+          is-zjit: true
+        continue-on-error: true
+        timeout-minutes: 3
+
+      - name: make ${{ matrix.test_task }}
+        run: |
+          test -n "${LAUNCHABLE_STDOUT}" && exec 1> >(tee "${LAUNCHABLE_STDOUT}")
+          test -n "${LAUNCHABLE_STDERR}" && exec 2> >(tee "${LAUNCHABLE_STDERR}")
+
+          set -x
+          make -s ${{ matrix.test_task }} ${TESTS:+TESTS="$TESTS"} \
+            RUN_OPTS="$RUN_OPTS" MSPECOPT=--debug SPECOPTS="$SPECOPTS" \
+            TESTOPTS="$TESTOPTS" \
+            ZJIT_BINDGEN_DIFF_OPTS="$ZJIT_BINDGEN_DIFF_OPTS"
+        timeout-minutes: 90
+        env:
+          RUBY_TESTOPTS: '-q --tty=no'
+          EXCLUDES: '../src/test/.excludes-zjit'
+          TEST_BUNDLED_GEMS_ALLOW_FAILURES: ''
+          PRECHECK_BUNDLED_GEMS: 'no'
+          SYNTAX_SUGGEST_TIMEOUT: '30'
+          ZJIT_BINDGEN_DIFF_OPTS: '--exit-code'
+          CLANG_PATH: ${{ matrix.clang_path }}
+          LAUNCHABLE_STDOUT: ${{ steps.launchable.outputs.stdout_report_path }}
+          LAUNCHABLE_STDERR: ${{ steps.launchable.outputs.stderr_report_path }}
+        continue-on-error: ${{ matrix.continue-on-test_task || false }}
+
+      - name: Dump crash logs
+        if: ${{ failure() }}
+        continue-on-error: true
+        run: |
+          tail --verbose --lines=+1 rb_crash_*.txt
+          exit 1
+
+      - uses: ./.github/actions/slack
+        with:
+          label: ${{ matrix.test_task }} ${{ matrix.configure }}
+          SLACK_WEBHOOK_URL: ${{ secrets.SIMPLER_ALERTS_URL }} # ruby-lang slack: ruby/simpler-alerts-bot
+        if: ${{ failure() }}
+
+  result:
+    if: ${{ always() }}
+    name: ${{ github.workflow }} result
+    runs-on: ubuntu-22.04
+    needs: [make]
+    steps:
+      - name: ${{ github.workflow }} jobs have failed
+        run: exit 1
+        working-directory:
+        if: ${{ contains(needs.*.result, 'failure') || contains(needs.*.result, 'cancelled') }}
+
+  # Separated from `make` job to avoid making it a required status check for now
+  ruby-bench:
+    strategy:
+      matrix:
+        include:
+          # Test --call-threshold=2 with 2 iterations in total
+          - ruby_opts: '--zjit-call-threshold=2'
+            bench_opts: '--warmup=1 --bench=1 --excludes=shipit'
+            configure: '--enable-zjit=dev_nodebug' # --enable-zjit=dev is too slow
+
+    runs-on: ubuntu-24.04
+
+    if: >-
+      ${{!(false
+      || contains(github.event.head_commit.message, '[DOC]')
+      || contains(github.event.pull_request.title, '[DOC]')
+      || contains(github.event.pull_request.labels.*.name, 'Documentation')
+      || (github.event.pull_request.user.login == 'dependabot[bot]' && !startsWith(github.head_ref, 'dependabot/cargo'))
+      )}}
+
+    steps:
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with:
+          persist-credentials: false
+
+      - uses: ./.github/actions/setup/ubuntu
+
+      - uses: ./.github/actions/setup/directories
+        with:
+          srcdir: src
+          builddir: build
+          makeup: true
+
+      - name: Run configure
+        run: ../src/configure -C --disable-install-doc --prefix="$(pwd)/install" ${{ matrix.configure }}
+
+      - run: make install
+
+      - name: Checkout ruby-bench
+        uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with:
+          repository: ruby/ruby-bench
+          persist-credentials: false
+          path: ruby-bench
+
+      # If you want to skip failing benchmark, consider using `--excludes`.
+      # e.g. `bench_opts: '--warmup=1 --bench=1 --excludes=railsbench,lobsters'`
+      - name: Run ruby-bench
+        run: ruby run_benchmarks.rb -e "zjit::../build/install/bin/ruby ${{ matrix.ruby_opts }}" ${{ matrix.bench_opts }}
+        working-directory: ruby-bench
+        env:
+          BUNDLER_VERSION: 0
+
+      - uses: ./.github/actions/slack
+        with:
+          label: ruby-bench ${{ matrix.bench_opts }} ${{ matrix.ruby_opts }}
+          SLACK_WEBHOOK_URL: ${{ secrets.SIMPLER_ALERTS_URL }} # ruby-lang slack: ruby/simpler-alerts-bot
+        if: ${{ failure() }}
+
+defaults:
+  run:
+    working-directory: build
diff --git a/.github/zizmor.yml b/.github/zizmor.yml
new file mode 100644
index 0000000000..2a8cad1d5c
--- /dev/null
+++ b/.github/zizmor.yml
@@ -0,0 +1,33 @@
+# Ignore existing findings (baseline)
+# Composite action findings are suppressed inline with # zizmor: ignore
+rules:
+  artipacked:
+    # These jobs push back to the repo and need persisted credentials.
+    ignore:
+      - bundled_gems.yml
+      - default_gems_list.yml
+      - post_push.yml
+      - sync_default_gems.yml
+  dangerous-triggers:
+    ignore:
+      - auto_request_review.yml
+      - auto_review_pr.yml
+      - labeler.yml
+      - pr-playground.yml
+  dependabot-cooldown:
+    ignore:
+      - dependabot.yml
+  misfeature:
+    ignore:
+      - mingw.yml
+      - tarball-windows.yml
+      - windows.yml
+  unpinned-images:
+    ignore:
+      - compilers.yml
+  secrets-outside-env:
+    # All committers with write access are trusted; no need for environment-scoped secrets.
+    disable: true
+  unpinned-uses:
+    ignore:
+      - wsl.yml
diff --git a/.gitignore b/.gitignore
index f30842adb5..7ead3a81f5 100644
--- a/.gitignore
+++ b/.gitignore
@@ -21,6 +21,7 @@
 *.pch
 *.pdb
 *.rbinc
+*.rbbin
 *.rej
 *.s
 *.sav
@@ -96,6 +97,7 @@ lcov*.info
 /enc.mk
 /encdb.h
 /exts.mk
+/gc/*/exts.mk
 /goruby
 /id.[ch]
 /largefile.h
@@ -138,12 +140,12 @@ lcov*.info
 /test.rb
 /test-coverage.dat
 /tmp
+/vcpkg_installed
 /transdb.h
 /uncommon.mk
 /verconf.h
 /verconf.mk
 /web
-/yasmdata.rb
 
 # /bin/
 
@@ -166,6 +168,7 @@ lcov*.info
 
 # /coroutine/
 !/coroutine/**/*.s
+!/coroutine/**/*.S
 
 # /enc/trans/
 /enc/trans/*.c
@@ -232,7 +235,6 @@ lcov*.info
 
 # for `make test-bundler`
 /.rspec_status
-/tool/bundler/*.lock
 
 # /tool/
 /tool/config.guess
@@ -241,36 +243,49 @@ lcov*.info
 # /win32/
 /win32/*.ico
 
-# RJIT
-/include/ruby-*/*/rb_rjit_min_header-*.h
-/lib/ruby_vm/rjit/instruction.rb
-/lib/ruby_vm/rjit/instruction.rb
-/rjit_config.h
-/rb_rjit_header.h*
 
 # YJIT
 /yjit-bench
 /yjit_exit_locations.dump
 
+# Rust
+/target
+
 # /wasm/
 /wasm/tests/*.wasm
 
 # prism
 /lib/prism/compiler.rb
 /lib/prism/dispatcher.rb
+/lib/prism/dot_visitor.rb
 /lib/prism/dsl.rb
+/lib/prism/inspect_visitor.rb
 /lib/prism/mutation_compiler.rb
 /lib/prism/node.rb
+/lib/prism/reflection.rb
 /lib/prism/serialize.rb
 /lib/prism/visitor.rb
+/prism/internal/diagnostic.h
 /prism/api_node.c
 /prism/ast.h
+/prism/diagnostic.c
+/prism/json.c
 /prism/node.c
 /prism/prettyprint.c
 /prism/serialize.c
+/prism/tokens.c
+/prism/srcs.mk
+/dump_ast
+
+# prism (old file)
 /prism/token_type.c
 
 # tool/update-NEWS-gemlist.rb
 /bundled_gems.json
 /default_gems.json
 /gems/default_gems
+
+# AI agents
+/.claude
+/AGENTS.md
+/CLAUDE.md
diff --git a/.mailmap b/.mailmap
new file mode 100644
index 0000000000..213a0f4916
--- /dev/null
+++ b/.mailmap
@@ -0,0 +1,431 @@
+git[bot]                                <svn-admin@ruby-lang.org>
+git[bot]                                <svn-admin@ruby-lang.org> git <svn@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+svn[bot]                                <svn-admin@ruby-lang.org> svn <svn@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# a_matsuda
+Akira Matsuda                           <ronnie@dio.jp>
+Akira Matsuda                           <ronnie@dio.jp> <a_matsuda@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# aamine
+Minero Aoki                             <aamine@loveruby.net>
+Minero Aoki                             <aamine@loveruby.net> <aamine@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# akira
+akira yamada                            <akira@ruby-lang.org>
+## akira yamada                         <akira@ruby-lang.org> <akira@rice.p.arika.org>
+akira yamada                            <akira@ruby-lang.org> <akira@arika.org>
+akira yamada                            <akira@ruby-lang.org> <akira@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# akiyoshi
+AKIYOSHI, Masamichi                     <masamichi.akiyoshi@hp.com>
+AKIYOSHI, Masamichi                     <masamichi.akiyoshi@hp.com> <akiyoshi@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# akr
+Tanaka Akira                            <akr@fsij.org>
+Tanaka Akira                            <akr@fsij.org> <akr@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# arai
+Koji Arai                               <jca02266@nifty.ne.jp>
+Koji Arai                               <jca02266@nifty.ne.jp> <arai@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# arton
+Akio Tajima                             <artonx@yahoo.co.jp>
+Akio Tajima                             <artonx@yahoo.co.jp> <arton@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# aycabta
+aycabta                                 <aycabta@gmail.com>
+aycabta                                 <aycabta@gmail.com> <aycabta@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# ayumin
+Ayumu AIZAWA                            <ayumu.aizawa@gmail.com>
+Ayumu AIZAWA                            <ayumu.aizawa@gmail.com> <ayumin@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# azav
+Alexander Zavorine                      <alexandre.zavorine@nokia.com>
+Alexander Zavorine                      <alexandre.zavorine@nokia.com> <azav@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# charliesome
+Charlie Somerville                      <charliesome@ruby-lang.org>
+Charlie Somerville                      <charliesome@ruby-lang.org> <charliesome@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# dave
+Dave Thomas                             <dave@pragprog.com>
+Dave Thomas                             <dave@pragprog.com> <dave@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# davidflanagan
+David Flanagan                          <davidflanagan@ruby-lang.org>
+David Flanagan                          <davidflanagan@ruby-lang.org> <david@think32>
+David Flanagan                          <davidflanagan@ruby-lang.org> <david@davidflanagan.com>
+David Flanagan                          <davidflanagan@ruby-lang.org> <davidflanagan@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# dblack
+David A. Black                          <dblack@rubypal.com>
+David A. Black                          <dblack@rubypal.com> <dblack@wobblini.net>
+David A. Black                          <dblack@rubypal.com> <dblack@superlink.net>
+David A. Black                          <dblack@rubypal.com> <dblack@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# drbrain
+Eric Hodel                              <drbrain@segment7.net>
+Eric Hodel                              <drbrain@segment7.net> <drbrain@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# duerst
+Martin Dürst                            <duerst@it.aoyama.ac.jp>
+Martin Dürst                            <duerst@it.aoyama.ac.jp> <duerst@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# eban
+WATANABE Hirofumi                       <eban@ruby-lang.org>
+WATANABE Hirofumi                       <eban@ruby-lang.org> <eban@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# emboss
+Martin Bosslet                          <Martin.Bosslet@gmail.com>
+Martin Bosslet                          <Martin.Bosslet@gmail.com> <Martin.Bosslet@googlemail.com>
+Martin Bosslet                          <Martin.Bosslet@gmail.com> <emboss@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# eregon
+Benoit Daloze                           <eregontp@gmail.com>
+Benoit Daloze                           <eregontp@gmail.com> <eregon@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# evan
+Evan Phoenix                            <evan@ruby-lang.org>
+Evan Phoenix                            <evan@ruby-lang.org> <evan@fallingsnow.net>
+Evan Phoenix                            <evan@ruby-lang.org> <evan@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# glass
+Masaki Matsushita                       <glass.saga@gmail.com>
+Masaki Matsushita                       <glass.saga@gmail.com> <glass@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# gogotanaka
+Kazuki Tanaka                           <gogotanaka@ruby-lang.org>
+Kazuki Tanaka                           <gogotanaka@ruby-lang.org> <gogotanaka@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# gotoken
+Kentaro Goto                            <gotoken@gmail.com>
+Kentaro Goto                            <gotoken@gmail.com> <gotoken@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# gotoyuzo
+GOTOU Yuuzou                            <gotoyuzo@notwork.org>
+GOTOU Yuuzou                            <gotoyuzo@notwork.org> <gotoyuzo@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# gsinclair
+Gavin Sinclair                          <gsinclair@soyabean.com.au>
+Gavin Sinclair                          <gsinclair@soyabean.com.au> <gsinclair@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# H_Konishi
+KONISHI Hiromasa                        <konishih@fd6.so-net.ne.jp>
+KONISHI Hiromasa                        <konishih@fd6.so-net.ne.jp> <H_Konishi@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# headius
+Charles Oliver Nutter                   <headius@headius.com>
+Charles Oliver Nutter                   <headius@headius.com> <headius@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# hone
+Terence Lee                             <hone@heroku.com>
+Terence Lee                             <hone@heroku.com> <hone@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# hsbt
+Hiroshi SHIBATA                         <hsbt@ruby-lang.org>
+Hiroshi SHIBATA                         <hsbt@ruby-lang.org> <hsbt@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# iwamatsu
+Nobuhiro Iwamatsu                       <iwamatsu@nigauri.org>
+Nobuhiro Iwamatsu                       <iwamatsu@nigauri.org> <iwamatsu@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# jeg2
+James Edward Gray II                    <james@graysoftinc.com>
+James Edward Gray II                    <james@graysoftinc.com> <jeg2@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# jim
+Jim Weirich                             <jim@tardis.local>
+Jim Weirich                             <jim@tardis.local> <jim@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# k0kubun
+Takashi Kokubun                         <takashikkbn@gmail.com>
+Takashi Kokubun                         <takashikkbn@gmail.com> <k0kubun@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# kanemoto
+Yutaka Kanemoto                         <kanemoto@ruby-lang.org>
+Yutaka Kanemoto                         <kanemoto@ruby-lang.org> <kanemoto@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# katsu
+UENO Katsuhiro                          <katsu@blue.sky.or.jp>
+UENO Katsuhiro                          <katsu@blue.sky.or.jp> <katsu@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# kazu
+Kazuhiro NISHIYAMA                      <zn@mbf.nifty.com>
+Kazuhiro NISHIYAMA                      <zn@mbf.nifty.com> <kazu@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# keiju
+Keiju Ishitsuka                         <keiju@ishitsuka.com>
+Keiju Ishitsuka                         <keiju@ishitsuka.com> <keiju@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# knu
+Akinori MUSHA                           <knu@iDaemons.org>
+Akinori MUSHA                           <knu@iDaemons.org> <knu@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# ko1
+Koichi Sasada                           <ko1@atdot.net>
+Koichi Sasada                           <ko1@atdot.net> <ko1@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# kosaki
+KOSAKI Motohiro                         <kosaki.motohiro@gmail.com>
+KOSAKI Motohiro                         <kosaki.motohiro@gmail.com> <kosaki@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# kosako
+K.Kosako                                <sndgk393@ybb.ne.jp>
+K.Kosako                                <sndgk393@ybb.ne.jp> <kosako@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# kou
+Sutou Kouhei                            <kou@clear-code.com>
+Sutou Kouhei                            <kou@clear-code.com> <kou@cozmixng.org>
+Sutou Kouhei                            <kou@clear-code.com> <kou@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# kouji
+Kouji Takao                             <kouji.takao@gmail.com>
+Kouji Takao                             <kouji.takao@gmail.com> <kouji@takao7.net>
+Kouji Takao                             <kouji.takao@gmail.com> <kouji@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# ksaito
+Kazuo Saito                             <ksaito@uranus.dti.ne.jp>
+Kazuo Saito                             <ksaito@uranus.dti.ne.jp> <ksaito@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# ktsj
+Kazuki Tsujimoto                        <kazuki@callcc.net>
+Kazuki Tsujimoto                        <kazuki@callcc.net> <ktsj@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# luislavena
+Luis Lavena                             <luislavena@gmail.com>
+Luis Lavena                             <luislavena@gmail.com> <luislavena@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# mame
+Yusuke Endoh                            <mame@ruby-lang.org>
+## Yusuke Endoh                         <mame@ruby-lang.org> <mame@tsg.ne.jp>
+Yusuke Endoh                            <mame@ruby-lang.org> <mame@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# marcandre
+Marc-Andre Lafortune                    <github@marc-andre.ca>
+Marc-Andre Lafortune                    <ruby-core@marc-andre.ca>
+Marc-Andre Lafortune                    <ruby-core@marc-andre.ca> <marcandre@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# matz
+Yukihiro "Matz" Matsumoto               <matz@ruby.or.jp>
+Yukihiro "Matz" Matsumoto               <matz@ruby.or.jp> <matz@ruby-lang.org>
+Yukihiro "Matz" Matsumoto               <matz@ruby.or.jp> <matz@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# michal
+Michal Rokos                            <michal@ruby-lang.org>
+Michal Rokos                            <michal@ruby-lang.org> <michal@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# mneumann
+Michael Neumann                         <mneumann@ruby-lang.org>
+Michael Neumann                         <mneumann@ruby-lang.org> <mneumann@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# mrkn
+Kenta Murata                            <mrkn@mrkn.jp>
+Kenta Murata                            <mrkn@mrkn.jp> <muraken@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+Kenta Murata                            <mrkn@mrkn.jp> <3959+mrkn@users.noreply.github.com>
+Kenta Murata                            <mrkn@mrkn.jp> <mrkn@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# nagachika
+nagachika                               <nagachika@ruby-lang.org>
+nagachika                               <nagachika@ruby-lang.org> <nagachika@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# nagai
+Hidetoshi NAGAI                         <nagai@ai.kyutech.ac.jp>
+Hidetoshi NAGAI                         <nagai@ai.kyutech.ac.jp> <nagai@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# nahi
+Hiroshi Nakamura                        <nahi@ruby-lang.org>
+Hiroshi Nakamura                        <nahi@ruby-lang.org> <nahi@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# nari
+Narihiro Nakamura                       <authornari@gmail.com>
+Narihiro Nakamura                       <authornari@gmail.com> <nari@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# naruse
+NARUSE, Yui                             <naruse@airemix.jp>
+NARUSE, Yui                             <naruse@airemix.jp> <naruse@ruby-lang.org>
+NARUSE, Yui                             <naruse@airemix.jp> <naruse@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# ngoto
+Naohisa Goto                            <ngotogenome@gmail.com>
+Naohisa Goto                            <ngotogenome@gmail.com> <ngoto@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# nobu
+Nobuyoshi Nakada                        <nobu@ruby-lang.org>
+Nobuyoshi Nakada                        <nobu@ruby-lang.org> <nobu@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# normal
+Eric Wong                               <normal@ruby-lang.org>
+Eric Wong                               <normal@ruby-lang.org> <e@80x24.org>
+Eric Wong                               <normal@ruby-lang.org> <normal@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# ntalbott
+Nathaniel Talbott                       <ntalbott@ruby-lang.org>
+Nathaniel Talbott                       <ntalbott@ruby-lang.org> <ntalbott@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# ocean
+Hirokazu Yamamoto                       <ocean@m2.ccsnet.ne.jp>
+Hirokazu Yamamoto                       <ocean@m2.ccsnet.ne.jp> <ocean@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# odaira
+Rei Odaira                              <rodaira@us.ibm.com>
+Rei Odaira                              <rodaira@us.ibm.com> <Rei.Odaira@gmail.com>
+Rei Odaira                              <rodaira@us.ibm.com> <odaira@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# okkez
+okkez                                   <okkez000@gmail.com>
+okkez                                   <okkez000@gmail.com> <okkez@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# rhe
+Kazuki Yamaguchi                        <k@rhe.jp>
+Kazuki Yamaguchi                        <k@rhe.jp> <rhe@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# ryan
+Ryan Davis                              <ryand-github@zenspider.com>
+Ryan Davis                              <ryand-github@zenspider.com> <ryand-ruby@zenspider.com>
+Ryan Davis                              <ryand-github@zenspider.com> <ryan@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# samuel
+Samuel Williams                         <samuel.williams@oriontransfer.co.nz>
+Samuel Williams                         <samuel.williams@oriontransfer.co.nz> <samuel@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# seki
+Masatoshi SEKI                          <m_seki@mva.biglobe.ne.jp>
+Masatoshi SEKI                          <m_seki@mva.biglobe.ne.jp> <seki@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# ser
+Sean Russell                            <ser@germane-software.com>
+Sean Russell                            <ser@germane-software.com> <ser@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# shigek
+Shigeo Kobayashi                        <shigek@ruby-lang.org>
+Shigeo Kobayashi                        <shigek@ruby-lang.org> <shigek@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# shirosaki
+Hiroshi Shirosaki                       <h.shirosaki@gmail.com>
+Hiroshi Shirosaki                       <h.shirosaki@gmail.com> <shirosaki@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# sho-h
+Sho Hashimoto                           <sho-h@ruby-lang.org>
+Sho Hashimoto                           <sho-h@ruby-lang.org> <sho-h@netlab.jp>
+Sho Hashimoto                           <sho-h@ruby-lang.org> <sho.hsmt@gmail.com>
+Sho Hashimoto                           <sho-h@ruby-lang.org> <sho-h@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# shugo
+Shugo Maeda                             <shugo@ruby-lang.org>
+Shugo Maeda                             <shugo@ruby-lang.org> <shugo@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# shyouhei
+卜部昌平                                    <shyouhei@ruby-lang.org>
+卜部昌平                                    <shyouhei@ruby-lang.org> <shyouhei@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# siena
+Siena.                                  <siena@faculty.chiba-u.jp>
+Siena.                                  <siena@faculty.chiba-u.jp> <siena@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# sonots
+sonots                                  <sonots@gmail.com>
+sonots                                  <sonots@gmail.com> <sonots@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# sorah
+Sorah Fukumori                          <her@sorah.jp>
+Sorah Fukumori                          <her@sorah.jp> <sorah@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# stomar
+Marcus Stollsteimer                     <sto.mar@web.de>
+Marcus Stollsteimer                     <sto.mar@web.de> <stomar@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# suke
+Masaki Suketa                           <masaki.suketa@nifty.ne.jp>
+Masaki Suketa                           <masaki.suketa@nifty.ne.jp> <suke@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# tadd
+Tadashi Saito                           <tad.a.digger@gmail.com>
+Tadashi Saito                           <tad.a.digger@gmail.com> <tadd@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# tadf
+Tadayoshi Funaba                        <tadf@dotrb.org>
+Tadayoshi Funaba                        <tadf@dotrb.org> <tadf@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# takano32
+TAKANO Mitsuhiro                        <takano32@gmail.com>
+TAKANO Mitsuhiro                        <takano32@gmail.com> <takano32@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# tarui
+Masaya Tarui                            <tarui@ruby-lang.org>
+Masaya Tarui                            <tarui@ruby-lang.org> <tarui@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# technorama
+Technorama Ltd.                         <oss-ruby@technorama.net>
+Technorama Ltd.                         <oss-ruby@technorama.net> <technorama@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# tenderlove
+Aaron Patterson                         <tenderlove@ruby-lang.org>
+Aaron Patterson                         <tenderlove@ruby-lang.org> <tenderlove@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# tmm1
+Aman Gupta                              <ruby@tmm1.net>
+Aman Gupta                              <ruby@tmm1.net> <tmm1@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# ts
+Guy Decoux                              <ts@moulon.inra.fr>
+Guy Decoux                              <ts@moulon.inra.fr> <ts@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# ttate
+Takaaki Tateishi                        <ttate@ttsky.net>
+## Takaaki Tateishi                     <ttate@ttsky.net> <ttate@kt.jaist.ac.jp>
+Takaaki Tateishi                        <ttate@ttsky.net> <ttate@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# uema2
+Takaaki Uematsu                         <uema2x@jcom.home.ne.jp>
+Takaaki Uematsu                         <uema2x@jcom.home.ne.jp> <uema2@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# usa
+U.Nakamura                              <usa@ruby-lang.org>
+U.Nakamura                              <usa@ruby-lang.org> <usa@garbagecollect.jp>
+U.Nakamura                              <usa@ruby-lang.org> <usa@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# wakou
+Wakou Aoyama                            <wakou@ruby-lang.org>
+Wakou Aoyama                            <wakou@ruby-lang.org> <wakou@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# wanabe
+wanabe                                  <s.wanabe@gmail.com>
+wanabe                                  <s.wanabe@gmail.com> <wanabe@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# watson1978
+Watson                                  <watson1978@gmail.com>
+Watson                                  <watson1978@gmail.com> <watson1978@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# wew
+William Webber                          <william@williamwebber.com>
+William Webber                          <william@williamwebber.com> <wew@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# why
+why the lucky stiff                     <why@ruby-lang.org>
+why the lucky stiff                     <why@ruby-lang.org> <why@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# xibbar
+Takeyuki FUJIOKA                        <xibbar@ruby-lang.org>
+Takeyuki FUJIOKA                        <xibbar@ruby-lang.org> <xibbar@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# yugui
+Yuki Yugui Sonoda                       <yugui@yugui.jp>
+Yuki Yugui Sonoda                       <yugui@yugui.jp> <yugui@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# yui-knk
+yui-knk                                 <spiketeika@gmail.com>
+yui-knk                                 <spiketeika@gmail.com> <yui-knk@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# yuki
+Yuki Nishijima                          <yuki24@hey.com>
+Yuki Nishijima                          <yuki24@hey.com> <mail@yukinishijima.net>
+Yuki Nishijima                          <yuki24@hey.com> <yuki@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# zsombor
+Dee Zsombor                             <zsombor@ruby-lang.org>
+Dee Zsombor                             <zsombor@ruby-lang.org> <zsombor@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+
+# zzak
+zzak                                    <zzakscott@gmail.com>
+zzak                                    <zzakscott@gmail.com> <zzak@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
diff --git a/.rdoc_options b/.rdoc_options
index 760507c7a2..5172911e16 100644
--- a/.rdoc_options
+++ b/.rdoc_options
@@ -1,4 +1,37 @@
 ---
 page_dir: doc
-main_page: README.md
+main_page: index.md
 title: Documentation for Ruby development version
+visibility: :private
+rdoc_include:
+- doc
+
+exclude:
+- \.gemspec\z
+- lib/set/subclass_compatible.rb
+
+autolink_excluded_words:
+- Box
+- Class
+- Method
+- Module
+- Process
+- RDoc
+- Ruby
+- Set
+- ZJIT
+- YJIT
+
+canonical_root: https://docs.ruby-lang.org/en/master
+
+footer_content:
+  Ruby:
+    Documentation: index.html
+    Official Website: https://www.ruby-lang.org/
+    Playground: https://ruby.github.io/play-ruby/
+  Resources:
+    GitHub: https://github.com/ruby/ruby
+    Issue Tracker: https://bugs.ruby-lang.org/projects/ruby-master/issues
+    RubyGems: https://rubygems.org/
+  Community:
+    X: https://x.com/rubylangorg
diff --git a/.travis.yml b/.travis.yml
deleted file mode 100644
index bfae9130f3..0000000000
--- a/.travis.yml
+++ /dev/null
@@ -1,241 +0,0 @@
-# -*- 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.
-
-# We only manage non-amd64 free pipelines.
-# https://docs.travis-ci.com/user/billing-overview/
-
-language: c
-
-os: linux
-
-if: commit_message !~ /\[DOC\]/
-
-dist: focal
-
-git:
-  quiet: true
-
-cache:
-  ccache: true
-  directories:
-    - $HOME/config_2nd
-    - $HOME/.downloaded-cache
-
-env:
-  global:
-    # The tests skipped in `make test-all`.
-    - TEST_ALL_SKIPPED_TESTS=
-    # The tests executed separately by `make test-all`.
-    - TEST_ALL_SEPARATED_TESTS=
-    # Reset timestamps early
-    - _=$(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'
-    # 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 $travis_apt_get_options"
-    # -O1 is faster than -O3 in our tests.
-    - optflags=-O1
-    # -g0 disables backtraces when SEGV.  Do not set that.
-    - debugflags=-ggdb3
-
-.org.ruby-lang.ci.matrix-definitions:
-
-  - &gcc-10
-    compiler: gcc-10
-    before_install:
-      - tool/travis_retry.sh sudo bash -c "rm -rf '${TRAVIS_ROOT}/var/lib/apt/lists/'* && exec apt-get update -yq"
-      - >-
-        tool/travis_retry.sh sudo -E apt-get $travis_apt_get_options install
-        ccache
-        gcc-10
-        g++-10
-        libffi-dev
-        libncurses-dev
-        libncursesw5-dev
-        libreadline-dev
-        libssl-dev
-        libyaml-dev
-        openssl
-        zlib1g-dev
-
-  # --------
-
-  - &arm64-linux
-    name: arm64-linux
-    arch: arm64
-    <<: *gcc-10
-
-  - &ppc64le-linux
-    name: ppc64le-linux
-    arch: ppc64le
-    compiler: gcc
-
-  - &s390x-linux
-    name: s390x-linux
-    arch: s390x
-    dist: jammy
-    compiler: gcc
-    env:
-      # Avoid possible test failures with the zlib applying the following patch
-      # on s390x CPU architecture.
-      # https://github.com/madler/zlib/pull/410
-      - DFLTCC=0
-
-  - &arm32-linux
-    name: arm32-linux
-    arch: arm64
-    # https://packages.ubuntu.com/focal/crossbuild-essential-armhf
-    compiler: arm-linux-gnueabihf-gcc
-    env:
-      - SETARCH='setarch linux32 --verbose --32bit'
-      # The "TestReadline#test_interrupt_in_other_thread" started failing on arm32
-      # from https://www.travis-ci.com/github/ruby/ruby/jobs/529005145
-      - TEST_ALL_SKIPPED_TESTS=test_interrupt_in_other_thread
-    before_install:
-      - sudo dpkg --add-architecture armhf
-      - tool/travis_retry.sh sudo bash -c "rm -rf '${TRAVIS_ROOT}/var/lib/apt/lists/'* && exec apt-get update -yq"
-      - >-
-        tool/travis_retry.sh sudo -E apt-get $travis_apt_get_options install
-        ccache
-        crossbuild-essential-armhf
-        libc6:armhf
-        libstdc++-10-dev:armhf
-        libffi-dev:armhf
-        libncurses-dev:armhf
-        libncursesw5-dev:armhf
-        libreadline-dev:armhf
-        libssl-dev:armhf
-        libyaml-dev:armhf
-        linux-libc-dev:armhf
-        zlib1g-dev:armhf
-
-matrix:
-  include:
-    # Build every commit (Allowed Failures):
-    - <<: *arm32-linux
-    # Comment out as the 2nd arm64 pipeline is unstable.
-    # - <<: *arm64-linux
-    - <<: *ppc64le-linux
-    - <<: *s390x-linux
-  allow_failures:
-    # We see multiple errors indicating errors on the Travis environment itself in a short while:
-    # https://app.travis-ci.com/github/ruby/ruby/jobs/544382885
-    # https://app.travis-ci.com/github/ruby/ruby/jobs/544361370
-    # It's not a fault of Ruby's arm32 support but just Travis arm32 seems unsable.
-    - name: arm32-linux
-    # - name: arm64-linux
-    # We see "Some worker was crashed." in about 40% of recent ppc64le-linux jobs
-    # e.g. https://app.travis-ci.com/github/ruby/ruby/jobs/530959548
-    - name: ppc64le-linux
-    # Tentatively disable, because often hungs up **after** all tests
-    # have finished successfully and saving caches.
-    - name: s390x-linux
-  fast_finish: true
-
-before_script:
-  - . tool/ci_functions.sh
-  - |-
-    if [ -n "${TEST_ALL_SKIPPED_TESTS}" ]; then
-      TEST_ALL_OPTS="${TEST_ALL_OPTS} $(ci_to_excluded_test_opts "${TEST_ALL_SKIPPED_TESTS}")"
-      if [ -z "${TEST_ALL_SEPARATED_TESTS}" ]; then
-        TEST_ALL_SEPARATED_TESTS="${TEST_ALL_SKIPPED_TESTS}"
-      fi
-    fi
-  - |-
-    if [ -n "${TEST_ALL_SEPARATED_TESTS}" ]; then
-      TEST_ALL_OPTS_SEPARATED="$(ci_to_included_test_opts "${TEST_ALL_SEPARATED_TESTS}")"
-    fi
-  - echo TEST_ALL_OPTS="${TEST_ALL_OPTS}" TEST_ALL_OPTS_SEPARATED="${TEST_ALL_OPTS_SEPARATED}"
-  - rm -fr .ext autom4te.cache
-  - |-
-    [ -d ~/.downloaded-cache ] ||
-    mkdir ~/.downloaded-cache
-  - ln -s ~/.downloaded-cache
-  - "> config.status"
-  - "> .rbconfig.time"
-  - sed -f tool/prereq.status template/Makefile.in common.mk > Makefile
-  - make -s $JOBS up
-  - make -s $JOBS srcs
-  - rm -f config.status Makefile rbconfig.rb .rbconfig.time
-  - |-
-    if [ -d ~/config_2nd ]; then
-      cp -pr ~/config_2nd build
-    else
-      mkdir build
-    fi
-  - mkdir config_1st config_2nd gems/src
-  - chmod -R a-w .
-  - chmod -R u+w build config_1st config_2nd gems/src .bundle
-  - cd build
-  - |-
-    case "$CC" in
-    gcc*)   CC="ccache $CC${GCC_FLAGS:+ }$GCC_FLAGS -fno-diagnostics-color";;
-    clang*) CC="ccache $CC${GCC_FLAGS:+ }$GCC_FLAGS -fno-color-diagnostics";;
-    esac
-  - |-
-    [ ! -f config.cache ] ||
-    [ "$CC" = "`sed -n s/^ac_cv_prog_CC=//p config.cache`" ] ||
-    (set -x; exec rm config.cache)
-  - $SETARCH ../configure -C --disable-install-doc --prefix=$RUBY_PREFIX $CONFIG_FLAG
-  - cp -pr config.cache config.status .ext/include ../config_1st
-  - $SETARCH make reconfig
-  - cp -pr config.cache config.status .ext/include ../config_2nd
-  - (cd .. && exec diff -ru config_1st config_2nd)
-  - chmod u+w ..
-  - rm -rf ~/config_2nd
-  - mv ../config_2nd ~
-  - chmod u-w ..
-  - $SETARCH make -s $JOBS
-  - make -s install
-  - |-
-    [ -z "${GEMS_FOR_TEST}" ] ||
-    $RUBY_PREFIX/bin/gem install --no-document $GEMS_FOR_TEST
-  - echo "raise 'do not load ~/.irbrc in test'" > ~/.irbrc
-
-script:
-  - $SETARCH make -s test -o showflags TESTOPTS="${TESTOPTS=$JOBS -q --tty=no}"
-  - ../tool/travis_wait.sh $SETARCH make -s test-all -o exts TESTOPTS="$JOBS -q --tty=no ${TEST_ALL_OPTS}" RUBYOPT="-w"
-  # Run the failing tests separately returning ok status to check if it works,
-  # visualize them.
-  - |
-    if [ -n "${TEST_ALL_OPTS_SEPARATED}" ]; then
-      $SETARCH make -s test-all -o exts TESTOPTS="$JOBS -v --tty=no ${TEST_ALL_OPTS_SEPARATED}" RUBYOPT="-w" || :
-    fi
-  - $SETARCH make -s test-spec # not using `-j` because sometimes `mspec -j` silently dies
-  - $SETARCH make -s -o showflags leaked-globals
-
-# We enable Travis on the specific branches or forked repositories here.
-if: (repo = ruby/ruby AND (branch = master OR branch =~ /^ruby_\d_\d$/)) OR repo != ruby/ruby
-
-# We want to be notified when something happens.
-notifications:
-  irc:
-    channels:
-      - "chat.freenode.net#ruby-core"
-    on_success: change # [always|never|change] # default: always
-    on_failure: always # [always|never|change] # default: always
-    template:
-      - "%{message} by @%{author}: See %{build_url}"
-
-  webhooks:
-    urls:
-      - secure: mRsoS/UbqDkKkW5p3AEqM27d4SZnV6Gsylo3bm8T/deltQzTsGzZwrm7OIBXZv0UFZdE68XmPlyHfZFLSP2V9QZ7apXMf9/vw0GtcSe1gchtnjpAPF6lYBn7nMCbVPPx9cS0dwL927fjdRM1vj7IKZ2bk4F0lAJ25R25S6teqdk= # ruby-lang slack: ruby/simpler-alerts-bot (travis)
-    on_success: never
-    on_failure: always
-
-  email:
-    - jaruga@ruby-lang.org
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 13df6087ca..35e79dd3b9 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -1 +1 @@
-See ["Contributing to Ruby"](https://docs.ruby-lang.org/en/master/contributing_md.html), which includes setup and build instructions.
+See ["Contributing to Ruby"](https://docs.ruby-lang.org/en/master/contributing/contributing_md.html), which includes setup and build instructions.
diff --git a/COPYING b/COPYING
index 48e5a96de7..428ce03ed7 100644
--- a/COPYING
+++ b/COPYING
@@ -1,3 +1,5 @@
+{日本語}[rdoc-ref:COPYING.ja]
+
 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:
diff --git a/COPYING.ja b/COPYING.ja
index 230376bc60..5de2dbcc8f 100644
--- a/COPYING.ja
+++ b/COPYING.ja
@@ -1,3 +1,5 @@
+{English}[rdoc-ref:COPYING]
+
 本プログラムはフリーソフトウェアです．2-clause BSDL
 または以下に示す条件で本プログラムを再配布できます
 2-clause BSDLについてはBSDLファイルを参照して下さい．
diff --git a/Cargo.lock b/Cargo.lock
new file mode 100644
index 0000000000..2108276e72
--- /dev/null
+++ b/Cargo.lock
@@ -0,0 +1,766 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "anyhow"
+version = "1.0.100"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a23eb6b1614318a8071c9b2521f36b424b2c83db5eb3a0fead4a6c0809af6e61"
+
+[[package]]
+name = "autocfg"
+version = "1.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c08606f8c3cbf4ce6ec8e28fb0014a2c086708fe954eaa885384a6165172e7e8"
+
+[[package]]
+name = "bitflags"
+version = "1.3.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bef38d45163c2f1dde094a7dfd33ccf595c92905c8f8f4fdc18d06fb1037718a"
+
+[[package]]
+name = "bitflags"
+version = "2.11.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "843867be96c8daad0d758b57df9392b6d8d271134fce549de6ce169ff98a92af"
+
+[[package]]
+name = "capstone"
+version = "0.14.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f442ae0f2f3f1b923334b4a5386c95c69c1cfa072bafa23d6fae6d9682eb1dd4"
+dependencies = [
+ "capstone-sys",
+ "static_assertions",
+]
+
+[[package]]
+name = "capstone-sys"
+version = "0.18.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a4e8087cab6731295f5a2a2bd82989ba4f41d3a428aab2e7c98d8f4db38aac05"
+dependencies = [
+ "cc",
+]
+
+[[package]]
+name = "cc"
+version = "1.0.94"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "17f6e324229dc011159fcc089755d1e2e216a90d43a7dea6853ca740b84f35e7"
+
+[[package]]
+name = "cfg-if"
+version = "1.0.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9330f8b2ff13f34540b44e946ef35111825727b38d33286ef986142615121801"
+
+[[package]]
+name = "chacha20"
+version = "0.10.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6f8d983286843e49675a4b7a2d174efe136dc93a18d69130dd18198a6c167601"
+dependencies = [
+ "cfg-if",
+ "cpufeatures",
+ "rand_core",
+]
+
+[[package]]
+name = "console"
+version = "0.16.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d64e8af5551369d19cf50138de61f1c42074ab970f74e99be916646777f8fc87"
+dependencies = [
+ "encode_unicode",
+ "libc",
+ "windows-sys 0.61.2",
+]
+
+[[package]]
+name = "cpufeatures"
+version = "0.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8b2a41393f66f16b0823bb79094d54ac5fbd34ab292ddafb9a0456ac9f87d201"
+dependencies = [
+ "libc",
+]
+
+[[package]]
+name = "encode_unicode"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "34aa73646ffb006b8f5147f3dc182bd4bcb190227ce861fc4a4844bf8e3cb2c0"
+
+[[package]]
+name = "equivalent"
+version = "1.0.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "877a4ace8713b0bcf2a4e7eec82529c029f1d0619886d18145fea96c3ffe5c0f"
+
+[[package]]
+name = "errno"
+version = "0.3.14"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "39cab71617ae0d63f51a36d69f866391735b51691dbda63cf6f96d042b63efeb"
+dependencies = [
+ "libc",
+ "windows-sys 0.52.0",
+]
+
+[[package]]
+name = "fastrand"
+version = "1.9.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e51093e27b0797c359783294ca4f0a911c270184cb10f85783b118614a1501be"
+dependencies = [
+ "instant",
+]
+
+[[package]]
+name = "foldhash"
+version = "0.1.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a0d2fde1f7b3d48b8395d5f2de76c18a528bd6a9cdde438df747bfcba3e05d6f"
+
+[[package]]
+name = "getrandom"
+version = "0.4.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0de51e6874e94e7bf76d726fc5d13ba782deca734ff60d5bb2fb2607c7406555"
+dependencies = [
+ "cfg-if",
+ "libc",
+ "r-efi",
+ "rand_core",
+ "wasip2",
+ "wasip3",
+]
+
+[[package]]
+name = "hashbrown"
+version = "0.15.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9229cfe53dfd69f0609a49f65461bd93001ea1ef889cd5529dd176593f5338a1"
+dependencies = [
+ "foldhash",
+]
+
+[[package]]
+name = "hashbrown"
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+name = "wit-component"
+version = "0.244.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9d66ea20e9553b30172b5e831994e35fbde2d165325bec84fc43dbf6f4eb9cb2"
+dependencies = [
+ "anyhow",
+ "bitflags 2.11.0",
+ "indexmap",
+ "log",
+ "serde",
+ "serde_derive",
+ "serde_json",
+ "wasm-encoder",
+ "wasm-metadata",
+ "wasmparser",
+ "wit-parser",
+]
+
+[[package]]
+name = "wit-parser"
+version = "0.244.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ecc8ac4bc1dc3381b7f59c34f00b67e18f910c2c0f50015669dde7def656a736"
+dependencies = [
+ "anyhow",
+ "id-arena",
+ "indexmap",
+ "log",
+ "semver",
+ "serde",
+ "serde_derive",
+ "serde_json",
+ "unicode-xid",
+ "wasmparser",
+]
+
+[[package]]
+name = "yjit"
+version = "0.1.0"
+dependencies = [
+ "capstone",
+ "jit",
+]
+
+[[package]]
+name = "zjit"
+version = "0.0.1"
+dependencies = [
+ "capstone",
+ "insta",
+ "jit",
+ "rand",
+ "yjit",
+]
diff --git a/Cargo.toml b/Cargo.toml
new file mode 100644
index 0000000000..33010e65fb
--- /dev/null
+++ b/Cargo.toml
@@ -0,0 +1,64 @@
+# This is the root Cargo [workspace](https://doc.rust-lang.org/cargo/reference/workspaces.html)
+# and the root package for all the rust code that are statically linked into ruby. Rust tooling
+# limitations means all Rust code need to share a single archive library (staticlib) at the
+# integration point with non-rust code. (See rustlang/rust#44322 and #104707 for a taste of
+# the linking challenges.)
+#
+# Do not add required dependencies. This is a policy that helps downstream consumers and give
+# us tight control over what we ship. All of the optional dependencies are used exclusively
+# during development.
+#
+# Release builds avoid Cargo entirely because offline builds can fail even when none of the
+# optional dependencies are built (rust-lang/cargo#10352).
+
+[workspace]
+members = ["zjit", "yjit", "jit"]
+
+[package]
+name = "ruby"
+version = "0.0.0"
+edition = "2024"
+rust-version = "1.85.0"
+publish = false # Don't publish to crates.io
+
+[dependencies]
+yjit = { path = "yjit", optional = true }
+zjit = { path = "zjit", optional = true }
+
+[lib]
+crate-type = ["staticlib"]
+path = "ruby.rs"
+
+[features]
+disasm = ["yjit?/disasm", "zjit?/disasm"]
+runtime_checks = ["yjit?/runtime_checks", "zjit?/runtime_checks"]
+yjit = [ "dep:yjit" ]
+zjit = [ "dep:zjit" ]
+
+[profile.dev]
+opt-level = 1 # On 0, functions use so much stack space that we get stray `SystemStackError`s
+debug = true
+debug-assertions = true
+overflow-checks = true
+
+[profile.test]
+inherits = "dev"
+opt-level = 0
+
+[profile.dev_nodebug]
+inherits = "dev"
+
+[profile.stats]
+inherits = "release"
+
+[profile.release]
+# NOTE: --enable-yjit and zjit builds use `rustc` without going through Cargo. You
+# might want to update the `rustc` invocation if you change this profile.
+opt-level = 3
+# The extra robustness that comes from checking for arithmetic overflow is
+# worth the performance cost for the compiler.
+overflow-checks = true
+# Generate debug info
+debug = true
+# Use ThinLTO. Much smaller output for a small amount of build time increase.
+lto = "thin"
diff --git a/LEGAL b/LEGAL
index e352c55ee5..2777aa2c14 100644
--- a/LEGAL
+++ b/LEGAL
@@ -58,12 +58,12 @@ mentioned below.
 
 [ccan/list/list.h]
 
-  This file is licensed under the {MIT License}[rdoc-label:label-MIT+License].
+  This file is licensed under the {MIT License}[rdoc-ref:@MIT+License].
 
 [coroutine]
 
   Unless otherwise specified, these files are licensed under the
-  {MIT License}[rdoc-label:label-MIT+License].
+  {MIT License}[rdoc-ref:@MIT+License].
 
 [include/ruby/onigmo.h]
 [include/ruby/oniguruma.h]
@@ -546,7 +546,7 @@ mentioned below.
 
 [vsnprintf.c]
 
-  This file is under the {old-style BSD license}[rdoc-label:label-Old-style+BSD+license].
+  This file is under the {old-style BSD license}[rdoc-ref:@Old-style+BSD+license].
 
   >>>
     Copyright (c) 1990, 1993::
@@ -577,7 +577,7 @@ mentioned below.
 
 [missing/crypt.c]
 
-  This file is under the {old-style BSD license}[rdoc-label:label-Old-style+BSD+license].
+  This file is under the {old-style BSD license}[rdoc-ref:@Old-style+BSD+license].
 
   >>>
     Copyright (c) 1989, 1993::
@@ -588,7 +588,7 @@ mentioned below.
 
 [missing/setproctitle.c]
 
-  This file is under the {old-style BSD license}[rdoc-label:label-Old-style+BSD+license].
+  This file is under the {old-style BSD license}[rdoc-ref:@Old-style+BSD+license].
 
   >>>
     Copyright 2003:: Damien Miller
@@ -702,48 +702,22 @@ mentioned below.
     OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     SUCH DAMAGE.
 
-[ext/json/generator/generator.c]
+[ext/json/vendor/fpconv.c]
 
-  The file contains the following copyright notice.
+  This file is under the {Boost Software License}[rdoc-ref:@Boost+Software+License+1.0].
 
-  >>>
-    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.
+[ext/json/vendor/jeaiii-ltoa.h]
 
   >>>
-    Copyright (C) 1987:: Fujitsu LTD. (Itaru ICHIKAWA)
+    Copyright (c) 2024,2025 Enrico Thierbach - https://github.com/radiospiel
+    Copyright (c) 2022 James Edward Anhalt III - https://github.com/jeaiii/itoa
 
-    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.
+    {MIT License}[rdoc-ref:@MIT+License]
+
+[ext/json/vendor/ryu.h]
+  This file is adapted from the Ryu algorithm by Ulf Adams https://github.com/ulfjack/ryu.
+  It is dual-licensed under {Apache License 2.0}[rdoc-ref:@Apache+License+2.0] OR
+  {Boost Software License 1.0}[rdoc-ref:@Boost+Software+License+1.0].
 
 [ext/psych]
 [test/psych]
@@ -879,7 +853,7 @@ mentioned below.
   >>>
     RubyGems is copyrighted free software by Chad Fowler, Rich Kilmer, Jim
     Weirich and others.  You can redistribute it and/or modify it under
-    either the terms of the {MIT license}[rdoc-label:label-MIT+License], or the conditions
+    either the terms of the {MIT license}[rdoc-ref:@MIT+License], or the conditions
     below:
 
     1. You may make and give away verbatim copies of the source form of the
@@ -941,7 +915,7 @@ mentioned below.
     Portions copyright (c) 2010:: Andre Arko
     Portions copyright (c) 2009:: Engine Yard
 
-    {MIT License}[rdoc-label:label-MIT+License]
+    {MIT License}[rdoc-ref:@MIT+License]
 
 [lib/bundler/vendor/thor]
 
@@ -950,16 +924,16 @@ mentioned below.
   >>>
     Copyright (c) 2008 Yehuda Katz, Eric Hodel, et al.
 
-    {MIT License}[rdoc-label:label-MIT+License]
+    {MIT License}[rdoc-ref:@MIT+License]
 
-[lib/rubygems/resolver/molinillo]
+[lib/rubygems/vendor/molinillo]
 
   molinillo is under the following license.
 
   >>>
     Copyright (c) 2014 Samuel E. Giddins segiddins@segiddins.me
 
-    {MIT License}[rdoc-label:label-MIT+License]
+    {MIT License}[rdoc-ref:@MIT+License]
 
 [lib/bundler/vendor/pub_grub]
 
@@ -968,7 +942,7 @@ mentioned below.
   >>>
     Copyright (c) 2018 John Hawthorn
 
-    {MIT License}[rdoc-label:label-MIT+License]
+    {MIT License}[rdoc-ref:@MIT+License]
 
 [lib/bundler/vendor/connection_pool]
 
@@ -977,7 +951,7 @@ mentioned below.
   >>>
     Copyright (c) 2011 Mike Perham
 
-    {MIT License}[rdoc-label:label-MIT+License]
+    {MIT License}[rdoc-ref:@MIT+License]
 
 [lib/bundler/vendor/net-http-persistent]
 
@@ -986,7 +960,7 @@ mentioned below.
   >>>
     Copyright (c) Eric Hodel, Aaron Patterson
 
-    {MIT License}[rdoc-label:label-MIT+License]
+    {MIT License}[rdoc-ref:@MIT+License]
 
 [lib/did_you_mean]
 [lib/did_you_mean.rb]
@@ -997,7 +971,7 @@ mentioned below.
   >>>
     Copyright (c) 2014-2016 Yuki Nishijima
 
-    {MIT License}[rdoc-label:label-MIT+License]
+    {MIT License}[rdoc-ref:@MIT+License]
 
 [lib/error_highlight]
 [lib/error_highlight.rb]
@@ -1008,7 +982,7 @@ mentioned below.
   >>>
     Copyright (c) 2021 Yusuke Endoh
 
-    {MIT License}[rdoc-label:label-MIT+License]
+    {MIT License}[rdoc-ref:@MIT+License]
 
 [benchmark/so_ackermann.rb]
 [benchmark/so_array.rb]
@@ -1091,3 +1065,236 @@ mentioned below.
 
       From ftp://ftp.cs.berkeley.edu/pub/4bsd/README.Impt.License.Change
       paragraph 3 above is now null and void.
+
+== Boost Software License 1.0
+
+>>>
+      Boost Software License - Version 1.0 - August 17th, 2003
+
+      Permission is hereby granted, free of charge, to any person or organization
+      obtaining a copy of the software and accompanying documentation covered by
+      this license (the "Software") to use, reproduce, display, distribute,
+      execute, and transmit the Software, and to prepare derivative works of the
+      Software, and to permit third-parties to whom the Software is furnished to
+      do so, all subject to the following:
+
+      The copyright notices in the Software and this entire statement, including
+      the above license grant, this restriction and the following disclaimer,
+      must be included in all copies of the Software, in whole or in part, and
+      all derivative works of the Software, unless such copies or derivative
+      works are solely in the form of machine-executable object code generated by
+      a source language processor.
+
+      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, TITLE AND NON-INFRINGEMENT. IN NO EVENT
+      SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
+      FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
+      ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+      DEALINGS IN THE SOFTWARE.
+
+== Apache License 2.0
+
+>>>
+      Apache License
+      Version 2.0, January 2004
+      http://www.apache.org/licenses/
+
+      TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+      1. Definitions.
+
+         "License" shall mean the terms and conditions for use, reproduction,
+         and distribution as defined by Sections 1 through 9 of this document.
+
+         "Licensor" shall mean the copyright owner or entity authorized by
+         the copyright owner that is granting the License.
+
+         "Legal Entity" shall mean the union of the acting entity and all
+         other entities that control, are controlled by, or are under common
+         control with that entity. For the purposes of this definition,
+         "control" means (i) the power, direct or indirect, to cause the
+         direction or management of such entity, whether by contract or
+         otherwise, or (ii) ownership of fifty percent (50%) or more of the
+         outstanding shares, or (iii) beneficial ownership of such entity.
+
+         "You" (or "Your") shall mean an individual or Legal Entity
+         exercising permissions granted by this License.
+
+         "Source" form shall mean the preferred form for making modifications,
+         including but not limited to software source code, documentation
+         source, and configuration files.
+
+         "Object" form shall mean any form resulting from mechanical
+         transformation or translation of a Source form, including but
+         not limited to compiled object code, generated documentation,
+         and conversions to other media types.
+
+         "Work" shall mean the work of authorship, whether in Source or
+         Object form, made available under the License, as indicated by a
+         copyright notice that is included in or attached to the work
+         (an example is provided in the Appendix below).
+
+         "Derivative Works" shall mean any work, whether in Source or Object
+         form, that is based on (or derived from) the Work and for which the
+         editorial revisions, annotations, elaborations, or other modifications
+         represent, as a whole, an original work of authorship. For the purposes
+         of this License, Derivative Works shall not include works that remain
+         separable from, or merely link (or bind by name) to the interfaces of,
+         the Work and Derivative Works thereof.
+
+         "Contribution" shall mean any work of authorship, including
+         the original version of the Work and any modifications or additions
+         to that Work or Derivative Works thereof, that is intentionally
+         submitted to Licensor for inclusion in the Work by the copyright owner
+         or by an individual or Legal Entity authorized to submit on behalf of
+         the copyright owner. For the purposes of this definition, "submitted"
+         means any form of electronic, verbal, or written communication sent
+         to the Licensor or its representatives, including but not limited to
+         communication on electronic mailing lists, source code control systems,
+         and issue tracking systems that are managed by, or on behalf of, the
+         Licensor for the purpose of discussing and improving the Work, but
+         excluding communication that is conspicuously marked or otherwise
+         designated in writing by the copyright owner as "Not a Contribution."
+
+         "Contributor" shall mean Licensor and any individual or Legal Entity
+         on behalf of whom a Contribution has been received by Licensor and
+         subsequently incorporated within the Work.
+
+      2. Grant of Copyright License. Subject to the terms and conditions of
+         this License, each Contributor hereby grants to You a perpetual,
+         worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+         copyright license to reproduce, prepare Derivative Works of,
+         publicly display, publicly perform, sublicense, and distribute the
+         Work and such Derivative Works in Source or Object form.
+
+      3. Grant of Patent License. Subject to the terms and conditions of
+         this License, each Contributor hereby grants to You a perpetual,
+         worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+         (except as stated in this section) patent license to make, have made,
+         use, offer to sell, sell, import, and otherwise transfer the Work,
+         where such license applies only to those patent claims licensable
+         by such Contributor that are necessarily infringed by their
+         Contribution(s) alone or by combination of their Contribution(s)
+         with the Work to which such Contribution(s) was submitted. If You
+         institute patent litigation against any entity (including a
+         cross-claim or counterclaim in a lawsuit) alleging that the Work
+         or a Contribution incorporated within the Work constitutes direct
+         or contributory patent infringement, then any patent licenses
+         granted to You under this License for that Work shall terminate
+         as of the date such litigation is filed.
+
+      4. Redistribution. You may reproduce and distribute copies of the
+         Work or Derivative Works thereof in any medium, with or without
+         modifications, and in Source or Object form, provided that You
+         meet the following conditions:
+
+         a.  You must give any other recipients of the Work or
+             Derivative Works a copy of this License; and
+
+         b.  You must cause any modified files to carry prominent notices
+             stating that You changed the files; and
+
+         c.  You must retain, in the Source form of any Derivative Works
+             that You distribute, all copyright, patent, trademark, and
+             attribution notices from the Source form of the Work,
+             excluding those notices that do not pertain to any part of
+             the Derivative Works; and
+
+         d.  If the Work includes a "NOTICE" text file as part of its
+             distribution, then any Derivative Works that You distribute must
+             include a readable copy of the attribution notices contained
+             within such NOTICE file, excluding those notices that do not
+             pertain to any part of the Derivative Works, in at least one
+             of the following places: within a NOTICE text file distributed
+             as part of the Derivative Works; within the Source form or
+             documentation, if provided along with the Derivative Works; or,
+             within a display generated by the Derivative Works, if and
+             wherever such third-party notices normally appear. The contents
+             of the NOTICE file are for informational purposes only and
+             do not modify the License. You may add Your own attribution
+             notices within Derivative Works that You distribute, alongside
+             or as an addendum to the NOTICE text from the Work, provided
+             that such additional attribution notices cannot be construed
+             as modifying the License.
+
+         You may add Your own copyright statement to Your modifications and
+         may provide additional or different license terms and conditions
+         for use, reproduction, or distribution of Your modifications, or
+         for any such Derivative Works as a whole, provided Your use,
+         reproduction, and distribution of the Work otherwise complies with
+         the conditions stated in this License.
+
+      5. Submission of Contributions. Unless You explicitly state otherwise,
+         any Contribution intentionally submitted for inclusion in the Work
+         by You to the Licensor shall be under the terms and conditions of
+         this License, without any additional terms or conditions.
+         Notwithstanding the above, nothing herein shall supersede or modify
+         the terms of any separate license agreement you may have executed
+         with Licensor regarding such Contributions.
+
+      6. Trademarks. This License does not grant permission to use the trade
+         names, trademarks, service marks, or product names of the Licensor,
+         except as required for reasonable and customary use in describing the
+         origin of the Work and reproducing the content of the NOTICE file.
+
+      7. Disclaimer of Warranty. Unless required by applicable law or
+         agreed to in writing, Licensor provides the Work (and each
+         Contributor provides its Contributions) on an "AS IS" BASIS,
+         WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+         implied, including, without limitation, any warranties or conditions
+         of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
+         PARTICULAR PURPOSE. You are solely responsible for determining the
+         appropriateness of using or redistributing the Work and assume any
+         risks associated with Your exercise of permissions under this License.
+
+      8. Limitation of Liability. In no event and under no legal theory,
+         whether in tort (including negligence), contract, or otherwise,
+         unless required by applicable law (such as deliberate and grossly
+         negligent acts) or agreed to in writing, shall any Contributor be
+         liable to You for damages, including any direct, indirect, special,
+         incidental, or consequential damages of any character arising as a
+         result of this License or out of the use or inability to use the
+         Work (including but not limited to damages for loss of goodwill,
+         work stoppage, computer failure or malfunction, or any and all
+         other commercial damages or losses), even if such Contributor
+         has been advised of the possibility of such damages.
+
+      9. Accepting Warranty or Additional Liability. While redistributing
+         the Work or Derivative Works thereof, You may choose to offer,
+         and charge a fee for, acceptance of support, warranty, indemnity,
+         or other liability obligations and/or rights consistent with this
+         License. However, in accepting such obligations, You may act only
+         on Your own behalf and on Your sole responsibility, not on behalf
+         of any other Contributor, and only if You agree to indemnify,
+         defend, and hold each Contributor harmless for any liability
+         incurred by, or claims asserted against, such Contributor by reason
+         of your accepting any such warranty or additional liability.
+
+      END OF TERMS AND CONDITIONS
+
+      APPENDIX: How to apply the Apache License to your work.
+
+      >>>
+         To apply the Apache License to your work, attach the following
+         boilerplate notice, with the fields enclosed by brackets "[]"
+         replaced with your own identifying information. (Don't include
+         the brackets!)  The text should be enclosed in the appropriate
+         comment syntax for the file format. We also recommend that a
+         file or class name and description of purpose be included on the
+         same "printed page" as the copyright notice for easier
+         identification within third-party archives.
+
+      Copyright [yyyy] [name of copyright owner]
+
+      Licensed under the Apache License, Version 2.0 (the "License");
+      you may not use this file except in compliance with the License.
+      You may obtain a copy of the License at
+
+          http://www.apache.org/licenses/LICENSE-2.0
+
+      Unless required by applicable law or agreed to in writing, software
+      distributed under the License is distributed on an "AS IS" BASIS,
+      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+      See the License for the specific language governing permissions and
+      limitations under the License.
diff --git a/NEWS.md b/NEWS.md
index 912c9e6c1a..9ff290ad75 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -1,20 +1,16 @@
-# NEWS for Ruby 3.3.0
+# NEWS for Ruby 4.1.0
 
 This document is a list of user-visible feature changes
-since the **3.2.0** release, except for bug fixes.
+since the **4.0.0** release, except for bug fixes.
 
 Note that each entry is kept to a minimum, see links for details.
 
 ## Language changes
 
-## Command line options
-
-* A new `performance` warning category was introduced.
-  They are not displayed by default even in verbose mode.
-  Turn them on with `-W:performance` or `Warning[:performance] = true`. [[Feature #19538]]
-* The `RUBY_GC_HEAP_INIT_SLOTS` environment variable has been deprecated and
-  removed. Environment variables `RUBY_GC_HEAP_%d_INIT_SLOTS` should be
-  used instead.  [[Feature #19785]]
+* `Module#clone` and `Module#dup` no longer rewrite the lexical scope of
+  copied methods. Constants and class variables resolve through the
+  original class, consistent with inheritance and mixins.
+  [[Feature #21981]]
 
 ## Core classes updates
 
@@ -22,209 +18,252 @@ Note: We're only listing outstanding class updates.
 
 * Array
 
-    * Array#pack now raises ArgumentError for unknown directives. [[Bug #19150]]
+    * `Array#pack` accepts a new format `R` and `r` for unpacking unsigned
+      and signed LEB128 encoded integers. [[Feature #21785]]
+    * `Array#pack` accepts a new format `^` that returns the current offset.
+      Useful when combined with variable width formats like LEB128. [[Feature #21796]]
 
-* Dir
+* ENV
 
-    * Dir.for_fd added for returning a Dir object for the directory specified
-      by the provided directory file descriptor. [[Feature #19347]]
-    * Dir.fchdir added for changing the directory to the directory specified
-      by the provided directory file descriptor. [[Feature #19347]]
-    * Dir#chdir added for changing the directory to the directory specified by
-      the provided `Dir` object. [[Feature #19347]]
+    * `ENV.fetch_values` is added. It returns an array of values for the
+      given names, raising `KeyError` for missing names unless a block is
+      given. [[Feature #21781]]
 
-* MatchData
+* Kernel
 
-    * MatchData#named_captures now accepts optional `symbolize_names`
-      keyword. [[Feature #19591]]
+    * `Kernel#autoload_relative` and `Module#autoload_relative` are added.
+      These methods work like `autoload`, but resolve the file path relative
+      to the file where the method is called, similar to `require_relative`.
+      This makes it easier to autoload constants from files in the same
+      directory without hardcoding absolute paths or manipulating `$LOAD_PATH`.
+      [[Feature #15330]]
 
-* Module
+* MatchData
 
-    * Module#set_temporary_name added for setting a temporary name for a
-      module. [[Feature #19521]]
+    * `MatchData#integer_at` is added.  It converts the matched substring to
+      integer and return the result.  [[Feature #21932]]
 
-* ObjectSpace::WeakKeyMap
+* Regexp
 
-    * New core class to build collections with weak references.
-      The class use equality semantic to lookup keys like a regular hash,
-      but it doesn't hold strong references on the keys. [[Feature #18498]]
+    * All instances of `Regexp` are now frozen, not just literals.
+      Subclasses of `Regexp` are not frozen for compatibility.
+      [[Feature #8948]]
 
-* Process.warmup
+* Set
 
-    * Notify the Ruby virtual machine that the boot sequence is finished,
-      and that now is a good time to optimize the application. This is useful
-      for long running applications. The actual optimizations performed are entirely
-      implementation specific and may change in the future without notice. [[Feature #18885]]
+    * A deprecated behavior, `Set#to_set`, `Range#to_set`, and
+      `Enumerable#to_set` accepting arguments, was removed.  [[Feature #21390]]
 
-* Process::Status
+## Stdlib updates
 
-    * Process::Status#& and Process::Status#>> are deprecated. [[Bug #19868]]
+### The following bundled gems are added.
+
+
+We only list stdlib changes that are notable feature changes.
+
+Other changes are listed in the following sections. We also listed release
+history from the previous bundled version that is Ruby 3.4.0 if it has GitHub
+releases.
+
+### The following bundled gems are promoted from default gems.
+
+* tsort 0.2.0
+* win32-registry 0.1.2
+
+### The following default gem is added.
+
+### The following default gems are updated.
+
+* RubyGems 4.1.0.dev
+  * 4.0.3 to [v4.0.4][RubyGems-v4.0.4], [v4.0.5][RubyGems-v4.0.5], [v4.0.6][RubyGems-v4.0.6], [v4.0.7][RubyGems-v4.0.7], [v4.0.8][RubyGems-v4.0.8], [v4.0.9][RubyGems-v4.0.9], [v4.0.10][RubyGems-v4.0.10], [v4.0.11][RubyGems-v4.0.11], [v4.0.12][RubyGems-v4.0.12], [v4.0.13][RubyGems-v4.0.13]
+* bundler 4.1.0.dev
+  * 4.0.3 to [v4.0.4][bundler-v4.0.4], [v4.0.5][bundler-v4.0.5], [v4.0.6][bundler-v4.0.6], [v4.0.7][bundler-v4.0.7], [v4.0.8][bundler-v4.0.8], [v4.0.9][bundler-v4.0.9], [v4.0.10][bundler-v4.0.10], [v4.0.11][bundler-v4.0.11], [v4.0.12][bundler-v4.0.12], [v4.0.13][bundler-v4.0.13]
+* erb 6.0.4
+  * 6.0.1 to [v6.0.1.1][erb-v6.0.1.1], [v6.0.2][erb-v6.0.2], [v6.0.3][erb-v6.0.3], [v6.0.4][erb-v6.0.4]
+* ipaddr 1.2.9
+  * 1.2.8 to [v1.2.9][ipaddr-v1.2.9]
+* json 2.19.8
+  * 2.18.0 to [v2.18.1][json-v2.18.1], [v2.19.0][json-v2.19.0], [v2.19.1][json-v2.19.1], [v2.19.2][json-v2.19.2], [v2.19.3][json-v2.19.3], [v2.19.4][json-v2.19.4], [v2.19.5][json-v2.19.5], [v2.19.6][json-v2.19.6], [v2.19.7][json-v2.19.7]
+* openssl 4.0.2
+  * 4.0.0 to [v4.0.1][openssl-v4.0.1], [v4.0.2][openssl-v4.0.2]
+* prism 1.9.0
+  * 1.7.0 to [v1.8.0][prism-v1.8.0], [v1.8.1][prism-v1.8.1], [v1.9.0][prism-v1.9.0]
+* psych 5.4.0
+* resolv 0.7.1
+  * 0.7.0 to [v0.7.1][resolv-v0.7.1]
+* stringio 3.2.1.dev
+* strscan 3.1.9.dev
+  * 3.1.6 to [v3.1.7][strscan-v3.1.7], [v3.1.8][strscan-v3.1.8]
+* syntax_suggest 3.0.0
+* timeout 0.6.1
+  * 0.6.0 to [v0.6.1][timeout-v0.6.1]
+* zlib 3.2.3
+  * 3.2.2 to [v3.2.3][zlib-v3.2.3]
+
+### The following bundled gems are updated.
+
+* minitest 6.0.6
+* rake 13.4.2
+  * 13.3.1 to [v13.4.0][rake-v13.4.0], [v13.4.1][rake-v13.4.1], [v13.4.2][rake-v13.4.2]
+* test-unit 3.7.8
+  * 3.7.5 to [3.7.6][test-unit-3.7.6], [3.7.7][test-unit-3.7.7], [3.7.8][test-unit-3.7.8]
+* net-imap 0.6.4
+  * 0.6.2 to [v0.6.3][net-imap-v0.6.3], [v0.6.4][net-imap-v0.6.4]
+* rbs 4.0.2
+  * 3.10.0 to [v3.10.1][rbs-v3.10.1], [v3.10.2][rbs-v3.10.2], [v3.10.3][rbs-v3.10.3], [v3.10.4][rbs-v3.10.4], [v4.0.0.dev.5][rbs-v4.0.0.dev.5], [v4.0.0][rbs-v4.0.0], [v4.0.2][rbs-v4.0.2]
+* typeprof 0.32.0
+* mutex_m 0.3.0
+* bigdecimal 4.1.2
+  * 4.0.1 to [v4.1.0][bigdecimal-v4.1.0], [v4.1.1][bigdecimal-v4.1.1], [v4.1.2][bigdecimal-v4.1.2]
+* resolv-replace 0.2.0
+  * 0.1.1 to [v0.2.0][resolv-replace-v0.2.0]
+* syslog 0.4.0
+  * 0.3.0 to [v0.4.0][syslog-v0.4.0]
+* repl_type_completor 0.1.15
+  * 0.1.12 to [v0.1.13][repl_type_completor-v0.1.13], [v0.1.14][repl_type_completor-v0.1.14], [v0.1.15][repl_type_completor-v0.1.15]
+* pstore 0.2.1
+  * 0.2.0 to [v0.2.1][pstore-v0.2.1]
+* rdoc 7.2.0
+  * 7.0.3 to [v7.0.4][rdoc-v7.0.4], [v7.1.0][rdoc-v7.1.0], [v7.2.0][rdoc-v7.2.0]
+* win32ole 1.9.3
+  * 1.9.2 to [v1.9.3][win32ole-v1.9.3]
+* irb 1.18.0
+  * 1.16.0 to [v1.17.0][irb-v1.17.0], [v1.18.0][irb-v1.18.0]
+
+### RubyGems and Bundler
+
+Ruby 4.0 bundled RubyGems and Bundler version 4. see the following links for details.
 
-* Range
+## Supported platforms
 
-    * Range#reverse_each can now process beginless ranges with an Integer endpoint. [[Feature #18515]]
+## Compatibility issues
 
-* Refinement
+## Stdlib compatibility issues
 
-    * Add Refinement#target as an alternative of Refinement#refined_class.
-      Refinement#refined_class is deprecated and will be removed in Ruby
-      3.4.  [[Feature #19714]]
+## C API updates
 
-* String
+### Embedded TypedData
 
-    * String#unpack now raises ArgumentError for unknown directives. [[Bug #19150]]
-    * String#bytesplice now accepts new arguments index/length or range of the
-      source string to be copied.  [[Feature #19314]]
+* The `RUBY_TYPED_EMBEDDABLE` flag is now public and documented and can be used by C extensions.
+  It allows allocating C structs directly into Ruby object slots, which reduces pointer chasing,
+  and in some case memory usage.
+  See the C extension documentation for details. [[Feature #21853]]
 
-## Stdlib updates
+* Added new C23 inspired allocator functions, that takes the previous memory size.
+  This allow the Ruby GC to better keep track of memory usage, improving its heuristics.
+  It also improves the performance of system allocators that support C23 `free_sized`.
 
-* RubyGems and Bundler warn if users require gem that is scheduled to become the bundled gems
-  in the future version of Ruby. [[Feature #19351]] [[Feature #19776]] [[Feature #19843]]
-
-  Targeted libraries are:
-    * abbrev
-    * base64
-    * bigdecimal
-    * csv
-    * drb
-    * getoptlong
-    * mutex_m
-    * nkf
-    * observer
-    * resolv-replace
-    * rinda
-    * syslog
-
-* Socket#recv and Socket#recv_nonblock returns `nil` instead of an empty string on closed
-  connections. Socket#recvmsg and Socket#recvmsg_nonblock returns `nil` instead of an empty packet on closed
-  connections. [[Bug #19012]]
-
-* Random::Formatter#alphanumeric is extended to accept optional `chars`
-  keyword argument. [[Feature #18183]]
-
-The following default gem is added.
-
-* prism 0.15.1
-
-The following default gems are updated.
-
-* RubyGems 3.5.0.dev
-* bigdecimal 3.1.5
-* bundler 2.5.0.dev
-* csv 3.2.8
-* erb 4.0.3
-* fiddle 1.1.2
-* fileutils 1.7.1
-* io-console 0.6.1.dev
-* irb 1.8.3
-* nkf 0.1.3
-* openssl 3.2.0
-* optparse 0.4.0.pre.1
-* psych 5.1.1.1
-* reline 0.3.9
-* stringio 3.0.9
-* strscan 3.0.7
-* syntax_suggest 1.1.0
-* time 0.2.2
-* timeout 0.4.0
-* uri 0.12.2
-
-The following bundled gem is promoted from default gems.
-
-* racc 1.7.1
-
-The following bundled gems are updated.
-
-* minitest 5.20.0
-* test-unit 3.6.1
-* rexml 3.2.6
-* rss 0.3.0
-* net-imap 0.4.1
-* net-smtp 0.4.0
-* rbs 3.2.2
-* typeprof 0.21.8
-* debug 1.8.0
-
-See GitHub releases like [Logger](https://github.com/ruby/logger/releases) or
-changelog for details of the default gems or bundled gems.
+  However, it is important to note that passing an incorrect size to these function is undefined
+  behavior and may result in crashes or memory leaks.
 
-## Supported platforms
+  - `ruby_xfree_sized(void *ptr, size_t size)`
+  - `ruby_xrealloc_sized(void *ptr, size_t newsiz, size_t oldsiz)`
+  - `ruby_xrealloc2_sized(void *ptr, size_t newelems, size_t newsiz, size_t oldelems)`
 
-## Compatibility issues
+  [[Feature #21861]]
 
-## Stdlib compatibility issues
+### Removed APIs
 
-* `racc` is promoted to bundled gems.
-  * You need to add `racc` to your `Gemfile` if you use `racc` under bundler environment.
-* `ext/readline` is retired
-  * We have `reline` that is pure Ruby implementation compatible with `ext/readline` API. We rely on `reline` in the future. If you need to use `ext/readline`, you can install `ext/readline` via rubygems.org with `gem install readline-ext`.
-  * We no longer need to install libraries like `libreadline` or `libedit`.
+The following APIs, which have been deprecated for many years, are removed.
+[[Feature #21768]]
 
-## C API updates
+* old postponed job functions,
+* untyped data object type/functions,
+* old APIs to allocate a data object,
+* taintedness/trustedness enums/macros,
+* `rb_gc_force_recycle` function,
+* `rb_iterate` function,
+* and some functions and constants for internal use.
 
 ## Implementation improvements
 
-* `defined?(@ivar)` is optimized with Object Shapes.
-
-### YJIT
-
-* Major performance improvements over 3.2
-  * Support for splat and rest arguments has been improved.
-  * Registers are allocated for stack operations of the virtual machine.
-  * More calls with optional arguments are compiled.
-  * Exception handlers are also compiled.
-  * Instance variables no longer exit to the interpreter
-    with megamorphic object shapes.
-  * Unsupported call types no longer exit to the interpreter.
-  * `Integer#!=`, `String#!=`, `Kernel#block_given?`, `Kernel#is_a?`,
-    `Kernel#instance_of?`, `Module#===` are specially optimized.
-  * Now more than 3x faster than the interpreter on optcarrot!
-* Significantly improved memory usage over 3.2
-    * Metadata for compiled code uses a lot less memory.
-    * Generate more compact code on ARM64
-* Compilation speed is now slightly faster than 3.2.
-* Add `RubyVM::YJIT.enable` that can enable YJIT later
-  * You can start YJIT without modifying command-line arguments or environment variables.
-  * This can also be used to enable YJIT only once your application is
-    done booting. `--yjit-disable` can be used if you want to use other
-    YJIT options while disabling YJIT at boot.
-* Option to disable code GC and treat `--yjit-exec-mem-size` as a hard limit
-  * Can produce better copy-on-write behavior on servers using unicorn and forking
-* `ratio_in_yjit` stat produced by `--yjit-stats` is now avaiable in release builds,
-  a special stats or dev build is no longer required to access most stats.
-* Exit tracing option now supports sampling
-  * `--trace-exits-sample-rate=N`
-* More thorough testing and multiple bug fixes
-* `--yjit-stats=quiet` is added to avoid printing stats on exit.
-* `--yjit-perf` is added to facilitate profiling with Linux perf.
-
-### MJIT
-
-* MJIT is removed.
-  * `--disable-jit-support` is removed. Consider using `--disable-yjit --disable-rjit` instead.
-
-### RJIT
-
-* Introduced a pure-Ruby JIT compiler RJIT.
-  * RJIT supports only x86\_64 architecture on Unix platforms.
-  * Unlike MJIT, it doesn't require a C compiler at runtime.
-* RJIT exists only for experimental purposes.
-  * You should keep using YJIT in production.
-
-[Feature #18183]: https://bugs.ruby-lang.org/issues/18183
-[Feature #18498]: https://bugs.ruby-lang.org/issues/18498
-[Feature #18515]: https://bugs.ruby-lang.org/issues/18515
-[Feature #18885]: https://bugs.ruby-lang.org/issues/18885
-[Bug #19012]:     https://bugs.ruby-lang.org/issues/19012
-[Bug #19150]:     https://bugs.ruby-lang.org/issues/19150
-[Feature #19314]: https://bugs.ruby-lang.org/issues/19314
-[Feature #19347]: https://bugs.ruby-lang.org/issues/19347
-[Feature #19351]: https://bugs.ruby-lang.org/issues/19351
-[Feature #19521]: https://bugs.ruby-lang.org/issues/19521
-[Feature #19538]: https://bugs.ruby-lang.org/issues/19538
-[Feature #19591]: https://bugs.ruby-lang.org/issues/19591
-[Feature #19714]: https://bugs.ruby-lang.org/issues/19714
-[Feature #19776]: https://bugs.ruby-lang.org/issues/19776
-[Feature #19785]: https://bugs.ruby-lang.org/issues/19785
-[Feature #19843]: https://bugs.ruby-lang.org/issues/19843
-[Bug #19868]:     https://bugs.ruby-lang.org/issues/19868
+### Ractor
+
+A lot of work has gone into making Ractors more stable, performant, and usable. These improvements bring Ractor implementation closer to leaving experimental status.
+
+## JIT
+
+[Feature #8948]: https://bugs.ruby-lang.org/issues/8948
+[Feature #15330]: https://bugs.ruby-lang.org/issues/15330
+[Feature #21390]: https://bugs.ruby-lang.org/issues/21390
+[Feature #21768]: https://bugs.ruby-lang.org/issues/21768
+[Feature #21785]: https://bugs.ruby-lang.org/issues/21785
+[Feature #21796]: https://bugs.ruby-lang.org/issues/21796
+[Feature #21853]: https://bugs.ruby-lang.org/issues/21853
+[Feature #21861]: https://bugs.ruby-lang.org/issues/21861
+[Feature #21932]: https://bugs.ruby-lang.org/issues/21932
+[Feature #21981]: https://bugs.ruby-lang.org/issues/21981
+[RubyGems-v4.0.4]: https://github.com/rubygems/rubygems/releases/tag/v4.0.4
+[RubyGems-v4.0.5]: https://github.com/rubygems/rubygems/releases/tag/v4.0.5
+[RubyGems-v4.0.6]: https://github.com/rubygems/rubygems/releases/tag/v4.0.6
+[RubyGems-v4.0.7]: https://github.com/rubygems/rubygems/releases/tag/v4.0.7
+[RubyGems-v4.0.8]: https://github.com/rubygems/rubygems/releases/tag/v4.0.8
+[RubyGems-v4.0.9]: https://github.com/rubygems/rubygems/releases/tag/v4.0.9
+[RubyGems-v4.0.10]: https://github.com/rubygems/rubygems/releases/tag/v4.0.10
+[RubyGems-v4.0.11]: https://github.com/rubygems/rubygems/releases/tag/v4.0.11
+[RubyGems-v4.0.12]: https://github.com/rubygems/rubygems/releases/tag/v4.0.12
+[RubyGems-v4.0.13]: https://github.com/rubygems/rubygems/releases/tag/v4.0.13
+[bundler-v4.0.4]: https://github.com/rubygems/rubygems/releases/tag/bundler-v4.0.4
+[bundler-v4.0.5]: https://github.com/rubygems/rubygems/releases/tag/bundler-v4.0.5
+[bundler-v4.0.6]: https://github.com/rubygems/rubygems/releases/tag/bundler-v4.0.6
+[bundler-v4.0.7]: https://github.com/rubygems/rubygems/releases/tag/bundler-v4.0.7
+[bundler-v4.0.8]: https://github.com/rubygems/rubygems/releases/tag/bundler-v4.0.8
+[bundler-v4.0.9]: https://github.com/rubygems/rubygems/releases/tag/bundler-v4.0.9
+[bundler-v4.0.10]: https://github.com/rubygems/rubygems/releases/tag/bundler-v4.0.10
+[bundler-v4.0.11]: https://github.com/rubygems/rubygems/releases/tag/bundler-v4.0.11
+[bundler-v4.0.12]: https://github.com/rubygems/rubygems/releases/tag/bundler-v4.0.12
+[bundler-v4.0.13]: https://github.com/rubygems/rubygems/releases/tag/bundler-v4.0.13
+[erb-v6.0.1.1]: https://github.com/ruby/erb/releases/tag/v6.0.1.1
+[erb-v6.0.2]: https://github.com/ruby/erb/releases/tag/v6.0.2
+[erb-v6.0.3]: https://github.com/ruby/erb/releases/tag/v6.0.3
+[erb-v6.0.4]: https://github.com/ruby/erb/releases/tag/v6.0.4
+[ipaddr-v1.2.9]: https://github.com/ruby/ipaddr/releases/tag/v1.2.9
+[json-v2.18.1]: https://github.com/ruby/json/releases/tag/v2.18.1
+[json-v2.19.0]: https://github.com/ruby/json/releases/tag/v2.19.0
+[json-v2.19.1]: https://github.com/ruby/json/releases/tag/v2.19.1
+[json-v2.19.2]: https://github.com/ruby/json/releases/tag/v2.19.2
+[json-v2.19.3]: https://github.com/ruby/json/releases/tag/v2.19.3
+[json-v2.19.4]: https://github.com/ruby/json/releases/tag/v2.19.4
+[json-v2.19.5]: https://github.com/ruby/json/releases/tag/v2.19.5
+[json-v2.19.6]: https://github.com/ruby/json/releases/tag/v2.19.6
+[json-v2.19.7]: https://github.com/ruby/json/releases/tag/v2.19.7
+[openssl-v4.0.1]: https://github.com/ruby/openssl/releases/tag/v4.0.1
+[openssl-v4.0.2]: https://github.com/ruby/openssl/releases/tag/v4.0.2
+[prism-v1.8.0]: https://github.com/ruby/prism/releases/tag/v1.8.0
+[prism-v1.8.1]: https://github.com/ruby/prism/releases/tag/v1.8.1
+[prism-v1.9.0]: https://github.com/ruby/prism/releases/tag/v1.9.0
+[resolv-v0.7.1]: https://github.com/ruby/resolv/releases/tag/v0.7.1
+[strscan-v3.1.7]: https://github.com/ruby/strscan/releases/tag/v3.1.7
+[strscan-v3.1.8]: https://github.com/ruby/strscan/releases/tag/v3.1.8
+[timeout-v0.6.1]: https://github.com/ruby/timeout/releases/tag/v0.6.1
+[zlib-v3.2.3]: https://github.com/ruby/zlib/releases/tag/v3.2.3
+[rake-v13.4.0]: https://github.com/ruby/rake/releases/tag/v13.4.0
+[rake-v13.4.1]: https://github.com/ruby/rake/releases/tag/v13.4.1
+[rake-v13.4.2]: https://github.com/ruby/rake/releases/tag/v13.4.2
+[test-unit-3.7.6]: https://github.com/test-unit/test-unit/releases/tag/3.7.6
+[test-unit-3.7.7]: https://github.com/test-unit/test-unit/releases/tag/3.7.7
+[test-unit-3.7.8]: https://github.com/test-unit/test-unit/releases/tag/3.7.8
+[net-imap-v0.6.3]: https://github.com/ruby/net-imap/releases/tag/v0.6.3
+[net-imap-v0.6.4]: https://github.com/ruby/net-imap/releases/tag/v0.6.4
+[rbs-v3.10.1]: https://github.com/ruby/rbs/releases/tag/v3.10.1
+[rbs-v3.10.2]: https://github.com/ruby/rbs/releases/tag/v3.10.2
+[rbs-v3.10.3]: https://github.com/ruby/rbs/releases/tag/v3.10.3
+[rbs-v3.10.4]: https://github.com/ruby/rbs/releases/tag/v3.10.4
+[rbs-v4.0.0.dev.5]: https://github.com/ruby/rbs/releases/tag/v4.0.0.dev.5
+[rbs-v4.0.0]: https://github.com/ruby/rbs/releases/tag/v4.0.0
+[rbs-v4.0.2]: https://github.com/ruby/rbs/releases/tag/v4.0.2
+[bigdecimal-v4.1.0]: https://github.com/ruby/bigdecimal/releases/tag/v4.1.0
+[bigdecimal-v4.1.1]: https://github.com/ruby/bigdecimal/releases/tag/v4.1.1
+[bigdecimal-v4.1.2]: https://github.com/ruby/bigdecimal/releases/tag/v4.1.2
+[resolv-replace-v0.2.0]: https://github.com/ruby/resolv-replace/releases/tag/v0.2.0
+[syslog-v0.4.0]: https://github.com/ruby/syslog/releases/tag/v0.4.0
+[repl_type_completor-v0.1.13]: https://github.com/ruby/repl_type_completor/releases/tag/v0.1.13
+[repl_type_completor-v0.1.14]: https://github.com/ruby/repl_type_completor/releases/tag/v0.1.14
+[repl_type_completor-v0.1.15]: https://github.com/ruby/repl_type_completor/releases/tag/v0.1.15
+[pstore-v0.2.1]: https://github.com/ruby/pstore/releases/tag/v0.2.1
+[rdoc-v7.0.4]: https://github.com/ruby/rdoc/releases/tag/v7.0.4
+[rdoc-v7.1.0]: https://github.com/ruby/rdoc/releases/tag/v7.1.0
+[rdoc-v7.2.0]: https://github.com/ruby/rdoc/releases/tag/v7.2.0
+[win32ole-v1.9.3]: https://github.com/ruby/win32ole/releases/tag/v1.9.3
+[irb-v1.17.0]: https://github.com/ruby/irb/releases/tag/v1.17.0
+[irb-v1.18.0]: https://github.com/ruby/irb/releases/tag/v1.18.0
diff --git a/README.EXT b/README.EXT
deleted file mode 100644
index 48b8d964c4..0000000000
--- a/README.EXT
+++ /dev/null
@@ -1 +0,0 @@
-Moved to doc/extension.rdoc
diff --git a/README.EXT.ja b/README.EXT.ja
deleted file mode 100644
index f884ecbb0e..0000000000
--- a/README.EXT.ja
+++ /dev/null
@@ -1 +0,0 @@
-doc/extension.ja.rdocに移動しました
diff --git a/README.ja.md b/README.ja.md
index 0d2d309fb8..9bbc3a83a5 100644
--- a/README.ja.md
+++ b/README.ja.md
@@ -1,10 +1,10 @@
 [![Actions Status: MinGW](https://github.com/ruby/ruby/workflows/MinGW/badge.svg)](https://github.com/ruby/ruby/actions?query=workflow%3A"MinGW")
-[![Actions Status: RJIT](https://github.com/ruby/ruby/workflows/RJIT/badge.svg)](https://github.com/ruby/ruby/actions?query=workflow%3A"RJIT")
 [![Actions Status: Ubuntu](https://github.com/ruby/ruby/workflows/Ubuntu/badge.svg)](https://github.com/ruby/ruby/actions?query=workflow%3A"Ubuntu")
 [![Actions Status: Windows](https://github.com/ruby/ruby/workflows/Windows/badge.svg)](https://github.com/ruby/ruby/actions?query=workflow%3A"Windows")
 [![AppVeyor status](https://ci.appveyor.com/api/projects/status/0sy8rrxut4o0k960/branch/master?svg=true)](https://ci.appveyor.com/project/ruby/ruby/branch/master)
 [![Travis Status](https://app.travis-ci.com/ruby/ruby.svg?branch=master)](https://app.travis-ci.com/ruby/ruby)
-[![Cirrus Status](https://api.cirrus-ci.com/github/ruby/ruby.svg)](https://cirrus-ci.com/github/ruby/ruby/master)
+
+[English](rdoc-ref:README.md)
 
 # Rubyとは
 
@@ -41,11 +41,15 @@ https://www.ruby-lang.org/ja/downloads/
 
 ミラーをGitHubに公開しています． 以下のコマンドでリポジトリを取得できます．
 
-    $ git clone https://github.com/ruby/ruby.git
+```console
+$ git clone https://github.com/ruby/ruby.git
+```
 
 他のブランチの一覧は次のコマンドで見られます．
 
-    $ git ls-remote https://github.com/ruby/ruby.git
+```console
+$ git ls-remote https://github.com/ruby/ruby.git
+```
 
 Rubyリポジトリの本来のmasterは https://git.ruby-lang.org/ruby.git にあります．
 コミッタはこちらを使います．
diff --git a/README.md b/README.md
index c0cbf05b7a..02435b419e 100644
--- a/README.md
+++ b/README.md
@@ -1,10 +1,9 @@
 [![Actions Status: MinGW](https://github.com/ruby/ruby/workflows/MinGW/badge.svg)](https://github.com/ruby/ruby/actions?query=workflow%3A"MinGW")
-[![Actions Status: RJIT](https://github.com/ruby/ruby/workflows/RJIT/badge.svg)](https://github.com/ruby/ruby/actions?query=workflow%3A"RJIT")
 [![Actions Status: Ubuntu](https://github.com/ruby/ruby/workflows/Ubuntu/badge.svg)](https://github.com/ruby/ruby/actions?query=workflow%3A"Ubuntu")
 [![Actions Status: Windows](https://github.com/ruby/ruby/workflows/Windows/badge.svg)](https://github.com/ruby/ruby/actions?query=workflow%3A"Windows")
-[![AppVeyor status](https://ci.appveyor.com/api/projects/status/0sy8rrxut4o0k960/branch/master?svg=true)](https://ci.appveyor.com/project/ruby/ruby/branch/master)
 [![Travis Status](https://app.travis-ci.com/ruby/ruby.svg?branch=master)](https://app.travis-ci.com/ruby/ruby)
-[![Cirrus Status](https://api.cirrus-ci.com/github/ruby/ruby.svg)](https://cirrus-ci.com/github/ruby/ruby/master)
+
+[日本語](rdoc-ref:README.ja.md)
 
 # What is Ruby?
 
@@ -88,7 +87,7 @@ Bugs should be reported at https://bugs.ruby-lang.org. Read ["Reporting Issues"]
 
 ## Contributing
 
-See ["Contributing to Ruby"](https://docs.ruby-lang.org/en/master/contributing_md.html), which includes setup and build instructions.
+See ["Contributing to Ruby"](https://docs.ruby-lang.org/en/master/contributing/contributing_md.html), which includes setup and build instructions.
 
 ## The Author
 
diff --git a/addr2line.c b/addr2line.c
index 2a69dd0966..19a6a425c1 100644
--- a/addr2line.c
+++ b/addr2line.c
@@ -56,11 +56,11 @@
 #  ifdef _AIX
 #pragma alloca
 #  else
-#   ifndef alloca		/* predefined by HP cc +Olibcalls */
+#   ifndef alloca                /* predefined by HP cc +Olibcalls */
 void *alloca();
 #   endif
 #  endif /* AIX */
-# endif	/* HAVE_ALLOCA_H */
+# endif        /* HAVE_ALLOCA_H */
 # ifndef UNREACHABLE
 #  define UNREACHABLE __builtin_unreachable()
 # endif
@@ -220,13 +220,13 @@ uleb128(const 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;
+        unsigned char b = (unsigned char)*(*p)++;
+        if (b < 0x80) {
+            r += (unsigned long)b << s;
+            break;
+        }
+        r += (b & 0x7f) << s;
+        s += 7;
     }
     return r;
 }
@@ -237,18 +237,18 @@ sleb128(const 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;
+        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;
 }
@@ -257,16 +257,16 @@ static const char *
 get_nth_dirname(unsigned long dir, const char *p, FILE *errout)
 {
     if (!dir--) {
-	return "";
+        return "";
     }
     while (dir--) {
-	while (*p) p++;
-	p++;
-	if (!*p) {
-	    kprintf("Unexpected directory number %lu in %s\n",
-		    dir, binary_filename);
-	    return "";
-	}
+        while (*p) p++;
+        p++;
+        if (!*p) {
+            kprintf("Unexpected directory number %lu in %s\n",
+                    dir, binary_filename);
+            return "";
+        }
     }
     return p;
 }
@@ -296,9 +296,11 @@ fill_filename(int file, uint8_t format, uint16_t version, const char *include_di
         for (i = 1; i <= file; i++) {
             filename = p;
             if (!*p) {
+#ifndef __APPLE__
                 /* Need to output binary file name? */
                 kprintf("Unexpected file number %d in %s at %tx\n",
                         file, binary_filename, filenames - obj->mapped);
+#endif
                 return;
             }
             while (*p) p++;
@@ -319,19 +321,19 @@ fill_filename(int file, uint8_t format, uint16_t version, const char *include_di
 
 static void
 fill_line(int num_traces, void **traces, uintptr_t addr, int file, int line,
-	  uint8_t format, uint16_t version, const char *include_directories, const char *filenames,
-	  obj_info_t *obj, line_info_t *lines, int offset, FILE *errout)
+          uint8_t format, uint16_t version, const char *include_directories, const char *filenames,
+          obj_info_t *obj, line_info_t *lines, int offset, FILE *errout)
 {
     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.
+        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, format, version, include_directories, filenames, &lines[i], obj, errout);
-	    lines[i].line = line;
-	}
+        if (addr < a && a < addr + 100) {
+            fill_filename(file, format, version, include_directories, filenames, &lines[i], obj, errout);
+            lines[i].line = line;
+        }
     }
 }
 
@@ -362,8 +364,8 @@ parse_debug_line_header(obj_info_t *obj, const char **pp, struct LineNumberProgr
 
     header->format = 4;
     if (header->unit_length == 0xffffffff) {
-	header->unit_length = *(uint64_t *)p;
-	p += sizeof(uint64_t);
+        header->unit_length = *(uint64_t *)p;
+        p += sizeof(uint64_t);
         header->format = 8;
     }
 
@@ -427,7 +429,7 @@ parse_debug_line_header(obj_info_t *obj, const char **pp, struct LineNumberProgr
 
 static int
 parse_debug_line_cu(int num_traces, void **traces, const char **debug_line,
-		obj_info_t *obj, line_info_t *lines, int offset, FILE *errout)
+                obj_info_t *obj, line_info_t *lines, int offset, FILE *errout)
 {
     const char *p = (const char *)*debug_line;
     struct LineNumberProgramHeader header;
@@ -448,105 +450,105 @@ parse_debug_line_cu(int num_traces, void **traces, const char **debug_line,
         return -1;
     is_stmt = header.default_is_stmt;
 
-#define FILL_LINE()						    \
-    do {							    \
-	fill_line(num_traces, traces, addr, file, line,		    \
+#define FILL_LINE()                                                 \
+    do {                                                            \
+        fill_line(num_traces, traces, addr, file, line,             \
                   header.format,                                    \
                   header.version,                                   \
                   header.include_directories,                       \
                   header.filenames,                                 \
-		  obj, lines, offset, errout);                      \
-	/*basic_block = prologue_end = epilogue_begin = 0;*/	    \
+                  obj, lines, offset, errout);                      \
+        /*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(&p) * header.minimum_instruction_length;
-	    addr += a;
-	    break;
-	case DW_LNS_advance_line: {
-	    long a = sleb128(&p);
-	    line += a;
-	    break;
-	}
-	case DW_LNS_set_file:
-	    file = (unsigned int)uleb128(&p);
-	    break;
-	case DW_LNS_set_column:
-	    /*column = (unsigned int)*/(void)uleb128(&p);
-	    break;
-	case DW_LNS_negate_stmt:
-	    is_stmt = !is_stmt;
-	    break;
-	case DW_LNS_set_basic_block:
-	    /*basic_block = 1; */
-	    break;
-	case DW_LNS_const_add_pc:
-	    a = ((255UL - header.opcode_base) / header.line_range) *
-		header.minimum_instruction_length;
-	    addr += a;
-	    break;
-	case DW_LNS_fixed_advance_pc:
-	    a = *(uint16_t *)p;
-	    p += sizeof(uint16_t);
-	    addr += a;
-	    break;
-	case DW_LNS_set_prologue_end:
-	    /* prologue_end = 1; */
-	    break;
-	case DW_LNS_set_epilogue_begin:
-	    /* epilogue_begin = 1; */
-	    break;
-	case DW_LNS_set_isa:
-	    /* isa = (unsigned int)*/(void)uleb128(&p);
-	    break;
-	case 0:
-	    a = uleb128(&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(&p);
-		break;
-	    default:
-		kprintf("Unknown extended opcode: %d in %s\n",
-			op, binary_filename);
-	    }
-	    break;
-	default: {
+        unsigned long a;
+        unsigned char op = *p++;
+        switch (op) {
+        case DW_LNS_copy:
+            FILL_LINE();
+            break;
+        case DW_LNS_advance_pc:
+            a = uleb128(&p) * header.minimum_instruction_length;
+            addr += a;
+            break;
+        case DW_LNS_advance_line: {
+            long a = sleb128(&p);
+            line += a;
+            break;
+        }
+        case DW_LNS_set_file:
+            file = (unsigned int)uleb128(&p);
+            break;
+        case DW_LNS_set_column:
+            /*column = (unsigned int)*/(void)uleb128(&p);
+            break;
+        case DW_LNS_negate_stmt:
+            is_stmt = !is_stmt;
+            break;
+        case DW_LNS_set_basic_block:
+            /*basic_block = 1; */
+            break;
+        case DW_LNS_const_add_pc:
+            a = ((255UL - header.opcode_base) / header.line_range) *
+                header.minimum_instruction_length;
+            addr += a;
+            break;
+        case DW_LNS_fixed_advance_pc:
+            a = *(uint16_t *)p;
+            p += sizeof(uint16_t);
+            addr += a;
+            break;
+        case DW_LNS_set_prologue_end:
+            /* prologue_end = 1; */
+            break;
+        case DW_LNS_set_epilogue_begin:
+            /* epilogue_begin = 1; */
+            break;
+        case DW_LNS_set_isa:
+            /* isa = (unsigned int)*/(void)uleb128(&p);
+            break;
+        case 0:
+            a = uleb128(&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(&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();
-	}
-	}
+            FILL_LINE();
+        }
+        }
     }
     *debug_line = (char *)p;
     return 0;
@@ -554,17 +556,17 @@ parse_debug_line_cu(int num_traces, void **traces, const char **debug_line,
 
 static int
 parse_debug_line(int num_traces, void **traces,
-		 const char *debug_line, unsigned long size,
-		 obj_info_t *obj, line_info_t *lines, int offset, FILE *errout)
+                 const char *debug_line, unsigned long size,
+                 obj_info_t *obj, line_info_t *lines, int offset, FILE *errout)
 {
     const 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, errout))
-	    return -1;
+        if (parse_debug_line_cu(num_traces, traces, &debug_line, obj, lines, offset, errout))
+            return -1;
     }
     if (debug_line != debug_line_end) {
-	kprintf("Unexpected size of .debug_line in %s\n",
-		binary_filename);
+        kprintf("Unexpected size of .debug_line in %s\n",
+                binary_filename);
     }
     return 0;
 }
@@ -572,7 +574,7 @@ parse_debug_line(int num_traces, void **traces,
 /* 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, FILE *errout);
+           obj_info_t **objp, line_info_t *lines, int offset, FILE *errout);
 
 static void
 append_obj(obj_info_t **objp)
@@ -600,7 +602,7 @@ append_obj(obj_info_t **objp)
 // check the path pattern of "/usr/lib/debug/usr/bin/ruby.debug"
 static void
 follow_debuglink(const char *debuglink, int num_traces, void **traces,
-		 obj_info_t **objp, line_info_t *lines, int offset, FILE *errout)
+                 obj_info_t **objp, line_info_t *lines, int offset, FILE *errout)
 {
     static const char global_debug_dir[] = "/usr/lib/debug";
     const size_t global_debug_dir_len = sizeof(global_debug_dir) - 1;
@@ -610,13 +612,13 @@ follow_debuglink(const char *debuglink, int num_traces, void **traces,
 
     p = strrchr(binary_filename, '/');
     if (!p) {
-	return;
+        return;
     }
     p[1] = '\0';
 
     len = strlen(binary_filename);
     if (len >= PATH_MAX - global_debug_dir_len)
-	len = PATH_MAX - global_debug_dir_len - 1;
+        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;
@@ -635,12 +637,13 @@ follow_debuglink_build_id(const char *build_id, size_t build_id_size, int num_tr
                           obj_info_t **objp, line_info_t *lines, int offset, FILE *errout)
 {
     static const char global_debug_dir[] = "/usr/lib/debug/.build-id/";
+    static const char debug_suffix[] = ".debug";
     const size_t global_debug_dir_len = sizeof(global_debug_dir) - 1;
     char *p;
     obj_info_t *o1 = *objp, *o2;
     size_t i;
 
-    if (PATH_MAX < global_debug_dir_len + 1 + build_id_size * 2 + 6) return;
+    if (PATH_MAX < global_debug_dir_len + build_id_size * 2 + sizeof(debug_suffix)) return;
 
     memcpy(binary_filename, global_debug_dir, global_debug_dir_len);
     p = binary_filename + global_debug_dir_len;
@@ -651,7 +654,7 @@ follow_debuglink_build_id(const char *build_id, size_t build_id_size, int num_tr
         *p++ = tbl[n % 16];
         if (i == 0) *p++ = '/';
     }
-    strcpy(p, ".debug");
+    memcpy(p, debug_suffix, sizeof(debug_suffix));
 
     append_obj(objp);
     o2 = *objp;
@@ -2029,14 +2032,14 @@ uncompress_debug_section(ElfW(Shdr) *shdr, char *file, char **ptr)
     int ret = 0;
 
     if (chdr->ch_type != ELFCOMPRESS_ZLIB) {
-	/* unsupported compression type */
-	return 0;
+        /* unsupported compression type */
+        return 0;
     }
 
     *ptr = malloc(destsize);
     if (!*ptr) return 0;
     ret = uncompress((Bytef *)*ptr, &destsize,
-	    (const Bytef*)chdr + sizeof(ElfW(Chdr)),
+            (const Bytef*)chdr + sizeof(ElfW(Chdr)),
             shdr->sh_size - sizeof(ElfW(Chdr)));
     if (ret != Z_OK) goto fail;
     return destsize;
@@ -2051,7 +2054,7 @@ fail:
 /* 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, FILE *errout)
+           obj_info_t **objp, line_info_t *lines, int offset, FILE *errout)
 {
     int i, j;
     char *shstr;
@@ -2069,40 +2072,40 @@ fill_lines(int num_traces, void **traces, int check_debuglink,
 
     fd = open(binary_filename, O_RDONLY);
     if (fd < 0) {
-	goto fail;
+        goto fail;
     }
     filesize = lseek(fd, 0, SEEK_END);
     if (filesize < 0) {
-	int e = errno;
-	close(fd);
-	kprintf("lseek: %s\n", strerror(e));
-	goto fail;
+        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;
+        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;
+        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;
+        /*
+         * Huh? Maybe filename was overridden by setproctitle() and
+         * it match non-elf file.
+         */
+        goto fail;
     }
     obj->mapped = file;
     obj->mapped_size = (size_t)filesize;
@@ -2114,32 +2117,32 @@ fill_lines(int num_traces, void **traces, int check_debuglink,
 
     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;
+        switch (shdr[i].sh_type) {
+          case SHT_STRTAB:
+            if (!strcmp(section_name, ".strtab")) {
+                strtab_shdr = shdr + i;
+            }
+            else if (!strcmp(section_name, ".dynstr")) {
+                dynstr_shdr = shdr + i;
+            }
+            break;
+          case SHT_SYMTAB:
+            /* if (!strcmp(section_name, ".symtab")) */
+            symtab_shdr = shdr + i;
+            break;
+          case SHT_DYNSYM:
+            /* if (!strcmp(section_name, ".dynsym")) */
+            dynsym_shdr = shdr + i;
+            break;
           case SHT_NOTE:
             if (!strcmp(section_name, ".note.gnu.build-id")) {
                 note_gnu_build_id = shdr + i;
             }
             break;
-	  case SHT_PROGBITS:
-	    if (!strcmp(section_name, ".gnu_debuglink")) {
-		gnu_debuglink_shdr = shdr + i;
-	    }
+          case SHT_PROGBITS:
+            if (!strcmp(section_name, ".gnu_debuglink")) {
+                gnu_debuglink_shdr = shdr + i;
+            }
             else {
                 const char *debug_section_names[] = {
                     ".debug_abbrev",
@@ -2169,17 +2172,16 @@ fill_lines(int num_traces, void **traces, int check_debuglink,
                     break;
                 }
             }
-	    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)));
+    if (offset == 0) {
+        /* main executable */
+        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++) {
@@ -2196,14 +2198,14 @@ fill_lines(int num_traces, void **traces, int check_debuglink,
                 }
                 dlclose(handle);
             }
-	    if (ehdr->e_type == ET_EXEC) {
-		obj->base_addr = 0;
-	    }
-	    else {
-		/* PIE (position-independent executable) */
-		obj->base_addr = dladdr_fbase;
-	    }
-	}
+            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) {
@@ -2249,21 +2251,21 @@ use_symtab:
     }
 
     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, errout);
-	}
+        /* 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, errout);
+        }
         if (note_gnu_build_id && check_debuglink) {
             ElfW(Nhdr) *nhdr = (ElfW(Nhdr)*) (file + note_gnu_build_id->sh_offset);
             const char *build_id = (char *)(nhdr + 1) + nhdr->n_namesz;
             follow_debuglink_build_id(build_id, nhdr->n_descsz,
-			       num_traces, traces,
+                               num_traces, traces,
                                objp, lines, offset, errout);
         }
-	goto finish;
+        goto finish;
     }
 
     if (parse_debug_line(num_traces, traces,
@@ -2384,13 +2386,14 @@ fill_lines(int num_traces, void **traces, int check_debuglink,
         goto fail;
     }
     else {
-        kprintf("'%s' is not a "
 # ifdef __LP64__
-                "64"
+#   define bitsize "64"
 # else
-                "32"
+#   define bitsize "32"
 # endif
+        kprintf("'%s' is not a " bitsize
                 "-bit Mach-O file!\n",binary_filename);
+# undef bitsize
         close(fd);
         goto fail;
     }
@@ -2425,7 +2428,17 @@ found_mach_header:
                         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)
+                            if (strcmp(sect->sectname, debug_section_names[j]) != 0
+#ifdef __APPLE__
+                                    /* macOS clang 16 generates DWARF5, which have Mach-O
+                                     * section names that are limited to 16 characters,
+                                     * which causes sections with long names to be truncated
+                                     * and not match above.
+                                     * See: https://wiki.dwarfstd.org/Best_Practices.md#Mach-2d-O
+                                     */
+                                    && strncmp(sect->sectname, debug_section_names[j], 16) != 0
+#endif
+                                )
                                 continue;
 
                             s->ptr = file + sect->offset;
@@ -2532,8 +2545,8 @@ main_exe_path(FILE *errout)
     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;
+        kprintf("Can't get the path of ruby");
+        return -1;
     }
     len--; /* sysctl sets strlen+1 */
     return len;
@@ -2615,79 +2628,79 @@ rb_dump_backtrace_with_lines(int num_traces, void **traces, FILE *errout)
     char *main_path = NULL; /* used on printing backtrace */
     ssize_t len;
     if ((len = main_exe_path(errout)) > 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, errout);
-	    if (addr != (uintptr_t)-1) {
-		dladdr_fbases[0] = (void *)addr;
-	    }
-	}
+        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, 0, errout);
+            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) {
-		    if (info.dli_fname) lines[i].path = info.dli_fname;
-		    if (info.dli_sname) 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;
-	    if (path) lines[i].path = path;
+        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) {
+                    if (info.dli_fname) lines[i].path = info.dli_fname;
+                    if (info.dli_sname) 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;
+            if (path) lines[i].path = path;
             if (info.dli_sname) {
                 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, errout) == (uintptr_t)-1)
-		break;
-	}
+            strlcpy(binary_filename, path, PATH_MAX);
+            if (fill_lines(num_traces, traces, 1, &obj, lines, i, errout) == (uintptr_t)-1)
+                break;
+        }
 next_line:
-	continue;
+        continue;
     }
 
     /* output */
     for (i = 0; i < num_traces; i++) {
         print_line(&lines[i], traces[i], errout);
 
-	/* FreeBSD's backtrace may show _start and so on */
-	if (lines[i].sname && strcmp("main", lines[i].sname) == 0)
-	    break;
+        /* 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;
+        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);
+        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;
diff --git a/array.c b/array.c
index 1032696308..db4c2c4802 100644
--- a/array.c
+++ b/array.c
@@ -27,7 +27,11 @@
 #include "probes.h"
 #include "ruby/encoding.h"
 #include "ruby/st.h"
+#include "ruby/thread.h"
 #include "ruby/util.h"
+#include "ruby/ractor.h"
+#include "shape.h"
+#include "vm_core.h"
 #include "builtin.h"
 
 #if !ARRAY_DEBUG
@@ -37,15 +41,16 @@
 #include "ruby_assert.h"
 
 VALUE rb_cArray;
+VALUE rb_cArray_empty_frozen;
 
 /* Flags of RArray
  *
+ * 0:   RARRAY_SHARED_FLAG (equal to ELTS_SHARED)
+ *          The array is shared. The buffer this array points to is owned by
+ *          another array (the shared root).
  * 1:   RARRAY_EMBED_FLAG
  *          The array is embedded (its contents follow the header, rather than
  *          being on a separately allocated buffer).
- * 2:   RARRAY_SHARED_FLAG (equal to ELTS_SHARED)
- *          The array is shared. The buffer this array points to is owned by
- *          another array (the shared root).
  * 3-9: RARRAY_EMBED_LEN
  *          The length of the array when RARRAY_EMBED_FLAG is set.
  * 12:  RARRAY_SHARED_ROOT_FLAG
@@ -76,47 +81,49 @@ should_be_T_ARRAY(VALUE ary)
     return RB_TYPE_P(ary, T_ARRAY);
 }
 
-#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)), \
+#define ARY_HEAP_PTR(a) (RUBY_ASSERT(!ARY_EMBED_P(a)), RARRAY(a)->as.heap.ptr)
+#define ARY_HEAP_LEN(a) (RUBY_ASSERT(!ARY_EMBED_P(a)), RARRAY(a)->as.heap.len)
+#define ARY_HEAP_CAPA(a) (RUBY_ASSERT(!ARY_EMBED_P(a)), RUBY_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_PTR(a) (RUBY_ASSERT(ARY_EMBED_P(a)), RARRAY(a)->as.ary)
 #define ARY_EMBED_LEN(a) \
-    (assert(ARY_EMBED_P(a)), \
+    (RUBY_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_HEAP_SIZE(a) (RUBY_ASSERT(!ARY_EMBED_P(a)), RUBY_ASSERT(ARY_OWNS_HEAP_P(a)), ARY_CAPA(a) * sizeof(VALUE))
 
-#define ARY_OWNS_HEAP_P(a) (assert(should_be_T_ARRAY((VALUE)(a))), \
+#define ARY_OWNS_HEAP_P(a) (RUBY_ASSERT(should_be_T_ARRAY((VALUE)(a))), \
                             !FL_TEST_RAW((a), RARRAY_SHARED_FLAG|RARRAY_EMBED_FLAG))
 
 #define FL_SET_EMBED(a) do { \
-    assert(!ARY_SHARED_P(a)); \
+    RUBY_ASSERT(!ARY_SHARED_P(a)); \
     FL_SET((a), RARRAY_EMBED_FLAG); \
     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)); \
+    RUBY_ASSERT(!ARY_EMBED_P(ary)); \
     FL_SET((ary), RARRAY_SHARED_FLAG); \
 } while (0)
 #define FL_UNSET_SHARED(ary) FL_UNSET((ary), RARRAY_SHARED_FLAG)
 
+#define ARY_SET_PTR_FORCE(ary, p) \
+    (RARRAY(ary)->as.heap.ptr = (p))
 #define ARY_SET_PTR(ary, p) do { \
-    assert(!ARY_EMBED_P(ary)); \
-    assert(!OBJ_FROZEN(ary)); \
-    RARRAY(ary)->as.heap.ptr = (p); \
+    RUBY_ASSERT(!ARY_EMBED_P(ary)); \
+    RUBY_ASSERT(!OBJ_FROZEN(ary)); \
+    ARY_SET_PTR_FORCE(ary, p); \
 } while (0)
 #define ARY_SET_EMBED_LEN(ary, n) do { \
     long tmp_n = (n); \
-    assert(ARY_EMBED_P(ary)); \
+    RUBY_ASSERT(ARY_EMBED_P(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)); \
+    RUBY_ASSERT(!ARY_EMBED_P(ary)); \
     RARRAY(ary)->as.heap.len = (n); \
 } while (0)
 #define ARY_SET_LEN(ary, n) do { \
@@ -126,15 +133,15 @@ should_be_T_ARRAY(VALUE ary)
     else { \
         ARY_SET_HEAP_LEN((ary), (n)); \
     } \
-    assert(RARRAY_LEN(ary) == (n)); \
+    RUBY_ASSERT(RARRAY_LEN(ary) == (n)); \
 } while (0)
 #define ARY_INCREASE_PTR(ary, n) do  { \
-    assert(!ARY_EMBED_P(ary)); \
-    assert(!OBJ_FROZEN(ary)); \
+    RUBY_ASSERT(!ARY_EMBED_P(ary)); \
+    RUBY_ASSERT(!OBJ_FROZEN(ary)); \
     RARRAY(ary)->as.heap.ptr += (n); \
 } while (0)
 #define ARY_INCREASE_LEN(ary, n) do  { \
-    assert(!OBJ_FROZEN(ary)); \
+    RUBY_ASSERT(!OBJ_FROZEN(ary)); \
     if (ARY_EMBED_P(ary)) { \
         ARY_SET_EMBED_LEN((ary), RARRAY_LEN(ary)+(n)); \
     } \
@@ -145,31 +152,33 @@ should_be_T_ARRAY(VALUE ary)
 
 #define ARY_CAPA(ary) (ARY_EMBED_P(ary) ? ary_embed_capa(ary) : \
                        ARY_SHARED_ROOT_P(ary) ? RARRAY_LEN(ary) : ARY_HEAP_CAPA(ary))
+#define ARY_SET_CAPA_FORCE(ary, n) \
+    RARRAY(ary)->as.heap.aux.capa = (n);
 #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); \
+    RUBY_ASSERT(!ARY_EMBED_P(ary)); \
+    RUBY_ASSERT(!ARY_SHARED_P(ary)); \
+    RUBY_ASSERT(!OBJ_FROZEN(ary)); \
+    ARY_SET_CAPA_FORCE(ary, n); \
 } while (0)
 
 #define ARY_SHARED_ROOT_OCCUPIED(ary) (!OBJ_FROZEN(ary) && ARY_SHARED_ROOT_REFCNT(ary) == 1)
 #define ARY_SET_SHARED_ROOT_REFCNT(ary, value) do { \
-    assert(ARY_SHARED_ROOT_P(ary)); \
-    assert(!OBJ_FROZEN(ary)); \
-    assert((value) >= 0); \
+    RUBY_ASSERT(ARY_SHARED_ROOT_P(ary)); \
+    RUBY_ASSERT(!OBJ_FROZEN(ary)); \
+    RUBY_ASSERT((value) >= 0); \
     RARRAY(ary)->as.heap.aux.capa = (value); \
 } while (0)
 #define FL_SET_SHARED_ROOT(ary) do { \
-    assert(!OBJ_FROZEN(ary)); \
-    assert(!ARY_EMBED_P(ary)); \
+    RUBY_ASSERT(!OBJ_FROZEN(ary)); \
+    RUBY_ASSERT(!ARY_EMBED_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));
+    RUBY_ASSERT(!ARY_SHARED_P(a));
+    RUBY_ASSERT(!OBJ_FROZEN(a));
 
     RARRAY_ASET(a, i, v);
 }
@@ -179,14 +188,16 @@ static long
 ary_embed_capa(VALUE ary)
 {
     size_t size = rb_gc_obj_slot_size(ary) - offsetof(struct RArray, as.ary);
-    assert(size % sizeof(VALUE) == 0);
+    RUBY_ASSERT(size % sizeof(VALUE) == 0);
     return size / sizeof(VALUE);
 }
 
 static size_t
 ary_embed_size(long capa)
 {
-    return offsetof(struct RArray, as.ary) + (sizeof(VALUE) * capa);
+    size_t size = offsetof(struct RArray, as.ary) + (sizeof(VALUE) * capa);
+    if (size < sizeof(struct RArray)) size = sizeof(struct RArray);
+    return size;
 }
 
 static bool
@@ -233,23 +244,22 @@ rb_ary_size_as_embedded(VALUE ary)
 static VALUE
 ary_verify_(VALUE ary, const char *file, int line)
 {
-    assert(RB_TYPE_P(ary, T_ARRAY));
+    RUBY_ASSERT(RB_TYPE_P(ary, T_ARRAY));
 
     if (ARY_SHARED_P(ary)) {
         VALUE root = ARY_SHARED_ROOT(ary);
         const VALUE *ptr = ARY_HEAP_PTR(ary);
         const VALUE *root_ptr = RARRAY_CONST_PTR(root);
         long len = ARY_HEAP_LEN(ary), root_len = RARRAY_LEN(root);
-        assert(ARY_SHARED_ROOT_P(root) || OBJ_FROZEN(root));
-        assert(root_ptr <= ptr && ptr + len <= root_ptr + root_len);
+        RUBY_ASSERT(ARY_SHARED_ROOT_P(root) || OBJ_FROZEN(root));
+        RUBY_ASSERT(root_ptr <= ptr && ptr + len <= root_ptr + root_len);
         ary_verify(root);
     }
     else if (ARY_EMBED_P(ary)) {
-        assert(!ARY_SHARED_P(ary));
-        assert(RARRAY_LEN(ary) <= ary_embed_capa(ary));
+        RUBY_ASSERT(!ARY_SHARED_P(ary));
+        RUBY_ASSERT(RARRAY_LEN(ary) <= ary_embed_capa(ary));
     }
     else {
-#if 1
         const VALUE *ptr = RARRAY_CONST_PTR(ary);
         long i, len = RARRAY_LEN(ary);
         volatile VALUE v;
@@ -258,17 +268,10 @@ ary_verify_(VALUE ary, const char *file, int line)
             v = ptr[i]; /* access check */
         }
         v = v;
-#endif
     }
 
     return ary;
 }
-
-void
-rb_ary_verify(VALUE ary)
-{
-    ary_verify(ary);
-}
 #else
 #define ary_verify(ary) ((void)0)
 #endif
@@ -326,7 +329,7 @@ ary_memfill(VALUE ary, long beg, long size, VALUE 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));
+    RUBY_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);
@@ -351,7 +354,7 @@ ary_memcpy(VALUE ary, long beg, long argc, const VALUE *argv)
 }
 
 static VALUE *
-ary_heap_alloc(size_t capa)
+ary_heap_alloc_buffer(size_t capa)
 {
     return ALLOC_N(VALUE, capa);
 }
@@ -359,7 +362,7 @@ ary_heap_alloc(size_t capa)
 static void
 ary_heap_free_ptr(VALUE ary, const VALUE *ptr, long size)
 {
-    ruby_sized_xfree((void *)ptr, size);
+    ruby_xfree_sized((void *)ptr, size);
 }
 
 static void
@@ -371,6 +374,7 @@ ary_heap_free(VALUE ary)
 static size_t
 ary_heap_realloc(VALUE ary, size_t new_capa)
 {
+    RUBY_ASSERT(!OBJ_FROZEN(ary));
     SIZED_REALLOC_N(RARRAY(ary)->as.heap.ptr, VALUE, new_capa, ARY_HEAP_CAPA(ary));
     ary_verify(ary);
 
@@ -380,32 +384,33 @@ ary_heap_realloc(VALUE ary, size_t new_capa)
 void
 rb_ary_make_embedded(VALUE ary)
 {
-    assert(rb_ary_embeddable_p(ary));
+    RUBY_ASSERT(rb_ary_embeddable_p(ary));
     if (!ARY_EMBED_P(ary)) {
         const VALUE *buf = ARY_HEAP_PTR(ary);
         long len = ARY_HEAP_LEN(ary);
+        long capa = ARY_HEAP_CAPA(ary);
 
         FL_SET_EMBED(ary);
         ARY_SET_EMBED_LEN(ary, len);
 
         MEMCPY((void *)ARY_EMBED_PTR(ary), (void *)buf, VALUE, len);
 
-        ary_heap_free_ptr(ary, buf, len * sizeof(VALUE));
+        ary_heap_free_ptr(ary, buf, capa * sizeof(VALUE));
     }
 }
 
 static void
 ary_resize_capa(VALUE ary, long capacity)
 {
-    assert(RARRAY_LEN(ary) <= capacity);
-    assert(!OBJ_FROZEN(ary));
-    assert(!ARY_SHARED_P(ary));
+    RUBY_ASSERT(RARRAY_LEN(ary) <= capacity);
+    RUBY_ASSERT(!OBJ_FROZEN(ary));
+    RUBY_ASSERT(!ARY_SHARED_P(ary));
 
     if (capacity > ary_embed_capa(ary)) {
         size_t new_capa = capacity;
         if (ARY_EMBED_P(ary)) {
             long len = ARY_EMBED_LEN(ary);
-            VALUE *ptr = ary_heap_alloc(capacity);
+            VALUE *ptr = ary_heap_alloc_buffer(capacity);
 
             MEMCPY(ptr, ARY_EMBED_PTR(ary), VALUE, len);
             FL_UNSET_EMBED(ary);
@@ -425,7 +430,7 @@ ary_resize_capa(VALUE ary, long capacity)
 
             if (len > capacity) len = capacity;
             MEMCPY((VALUE *)RARRAY(ary)->as.ary, ptr, VALUE, len);
-            ary_heap_free_ptr(ary, ptr, old_capa);
+            ary_heap_free_ptr(ary, ptr, old_capa * sizeof(VALUE));
 
             FL_SET_EMBED(ary);
             ARY_SET_LEN(ary, len);
@@ -440,9 +445,12 @@ 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);
+    RUBY_ASSERT(!ARY_SHARED_P(ary));
+    RUBY_ASSERT(old_capa >= capacity);
+    if (old_capa > capacity) {
+        size_t new_capa = ary_heap_realloc(ary, capacity);
+        ARY_SET_CAPA(ary, new_capa);
+    }
 
     ary_verify(ary);
 }
@@ -500,7 +508,7 @@ rb_ary_increment_share(VALUE shared_root)
 {
     if (!OBJ_FROZEN(shared_root)) {
         long num = ARY_SHARED_ROOT_REFCNT(shared_root);
-        assert(num >= 0);
+        RUBY_ASSERT(num >= 0);
         ARY_SET_SHARED_ROOT_REFCNT(shared_root, num + 1);
     }
     return shared_root;
@@ -509,9 +517,9 @@ rb_ary_increment_share(VALUE shared_root)
 static void
 rb_ary_set_shared(VALUE ary, VALUE shared_root)
 {
-    assert(!ARY_EMBED_P(ary));
-    assert(!OBJ_FROZEN(ary));
-    assert(ARY_SHARED_ROOT_P(shared_root) || OBJ_FROZEN(shared_root));
+    RUBY_ASSERT(!ARY_EMBED_P(ary));
+    RUBY_ASSERT(!OBJ_FROZEN(ary));
+    RUBY_ASSERT(ARY_SHARED_ROOT_P(shared_root) || OBJ_FROZEN(shared_root));
 
     rb_ary_increment_share(shared_root);
     FL_SET_SHARED(ary);
@@ -523,6 +531,8 @@ rb_ary_set_shared(VALUE ary, VALUE shared_root)
 static inline void
 rb_ary_modify_check(VALUE ary)
 {
+    RUBY_ASSERT(ruby_thread_has_gvl_p());
+
     rb_check_frozen(ary);
     ary_verify(ary);
 }
@@ -556,11 +566,11 @@ rb_ary_cancel_sharing(VALUE ary)
             rb_ary_decrement_share(shared_root);
         }
         else {
-            VALUE *ptr = ary_heap_alloc(len);
+            VALUE *ptr = ary_heap_alloc_buffer(len);
             MEMCPY(ptr, ARY_HEAP_PTR(ary), VALUE, len);
             rb_ary_unshare(ary);
-            ARY_SET_CAPA(ary, len);
-            ARY_SET_PTR(ary, ptr);
+            ARY_SET_CAPA_FORCE(ary, len);
+            ARY_SET_PTR_FORCE(ary, ptr);
         }
 
         rb_gc_writebarrier_remember(ary);
@@ -625,21 +635,32 @@ ary_ensure_room_for_push(VALUE ary, long add_len)
 
 /*
  *  call-seq:
- *    array.freeze -> self
+ *    freeze -> self
  *
- *  Freezes +self+; returns +self+:
+ *  Freezes +self+ (if not already frozen); returns +self+:
  *
  *    a = []
  *    a.frozen? # => false
  *    a.freeze
  *    a.frozen? # => true
  *
- *  An attempt to modify a frozen \Array raises FrozenError.
+ *  No further changes may be made to +self+;
+ *  raises FrozenError if a change is attempted.
+ *
+ *  Related: Kernel#frozen?.
  */
 
 VALUE
 rb_ary_freeze(VALUE ary)
 {
+    RUBY_ASSERT(RB_TYPE_P(ary, T_ARRAY));
+
+    if (OBJ_FROZEN(ary)) return ary;
+
+    if (!ARY_EMBED_P(ary) && !ARY_SHARED_P(ary) && !ARY_SHARED_ROOT_P(ary)) {
+        ary_shrink_capa(ary);
+    }
+
     return rb_obj_freeze(ary);
 }
 
@@ -666,23 +687,23 @@ static VALUE
 ary_alloc_embed(VALUE klass, long capa)
 {
     size_t size = ary_embed_size(capa);
-    assert(rb_gc_size_allocatable_p(size));
-    NEWOBJ_OF(ary, struct RArray, klass,
-                     T_ARRAY | RARRAY_EMBED_FLAG | (RGENGC_WB_PROTECTED_ARRAY ? FL_WB_PROTECTED : 0),
-                     size, 0);
-    /* Created array is:
-     *   FL_SET_EMBED((VALUE)ary);
-     *   ARY_SET_EMBED_LEN((VALUE)ary, 0);
-     */
-    return (VALUE)ary;
+    RUBY_ASSERT(rb_gc_size_allocatable_p(size));
+   /* Created array is:
+    *   FL_SET_EMBED((VALUE)ary);
+    *   ARY_SET_EMBED_LEN((VALUE)ary, 0);
+    */
+    return rb_newobj_of(klass, T_ARRAY | RARRAY_EMBED_FLAG, size);
 }
 
 static VALUE
 ary_alloc_heap(VALUE klass)
 {
-    NEWOBJ_OF(ary, struct RArray, klass,
-                     T_ARRAY | (RGENGC_WB_PROTECTED_ARRAY ? FL_WB_PROTECTED : 0),
-                     sizeof(struct RArray), 0);
+    NEWOBJ_OF(ary, struct RArray, klass, T_ARRAY, sizeof(struct RArray));
+
+    ary->as.heap.len = 0;
+    ary->as.heap.aux.capa = 0;
+    ary->as.heap.ptr = NULL;
+
     return (VALUE)ary;
 }
 
@@ -696,6 +717,8 @@ empty_ary_alloc(VALUE klass)
 static VALUE
 ary_new(VALUE klass, long capa)
 {
+    RUBY_ASSERT(ruby_thread_has_gvl_p());
+
     VALUE ary;
 
     if (capa < 0) {
@@ -713,9 +736,9 @@ ary_new(VALUE klass, long capa)
     else {
         ary = ary_alloc_heap(klass);
         ARY_SET_CAPA(ary, capa);
-        assert(!ARY_EMBED_P(ary));
+        RUBY_ASSERT(!ARY_EMBED_P(ary));
 
-        ARY_SET_PTR(ary, ary_heap_alloc(capa));
+        ARY_SET_PTR(ary, ary_heap_alloc_buffer(capa));
         ARY_SET_HEAP_LEN(ary, 0);
     }
 
@@ -777,24 +800,22 @@ static VALUE
 ec_ary_alloc_embed(rb_execution_context_t *ec, VALUE klass, long capa)
 {
     size_t size = ary_embed_size(capa);
-    assert(rb_gc_size_allocatable_p(size));
-    NEWOBJ_OF(ary, struct RArray, klass,
-            T_ARRAY | RARRAY_EMBED_FLAG | (RGENGC_WB_PROTECTED_ARRAY ? FL_WB_PROTECTED : 0),
-            size, ec);
-    /* Created array is:
-     *   FL_SET_EMBED((VALUE)ary);
-     *   ARY_SET_EMBED_LEN((VALUE)ary, 0);
-     */
-    return (VALUE)ary;
+    RUBY_ASSERT(rb_gc_size_allocatable_p(size));
+   /* Created array is:
+    *   FL_SET_EMBED((VALUE)ary);
+    *   ARY_SET_EMBED_LEN((VALUE)ary, 0);
+    */
+    return rb_ec_newobj_of(ec, klass, T_ARRAY | RARRAY_EMBED_FLAG, size);
 }
 
 static VALUE
 ec_ary_alloc_heap(rb_execution_context_t *ec, VALUE klass)
 {
-    NEWOBJ_OF(ary, struct RArray, klass,
-            T_ARRAY | (RGENGC_WB_PROTECTED_ARRAY ? FL_WB_PROTECTED : 0),
-            sizeof(struct RArray), ec);
-    return (VALUE)ary;
+    VALUE ary = rb_ec_newobj_of(ec, klass, T_ARRAY, sizeof(struct RArray));
+    RARRAY(ary)->as.heap.len = 0;
+    RARRAY(ary)->as.heap.aux.capa = 0;
+    RARRAY(ary)->as.heap.ptr = NULL;
+    return ary;
 }
 
 static VALUE
@@ -817,9 +838,9 @@ ec_ary_new(rb_execution_context_t *ec, VALUE klass, long capa)
     else {
         ary = ec_ary_alloc_heap(ec, klass);
         ARY_SET_CAPA(ary, capa);
-        assert(!ARY_EMBED_P(ary));
+        RUBY_ASSERT(!ARY_EMBED_P(ary));
 
-        ARY_SET_PTR(ary, ary_heap_alloc(capa));
+        ARY_SET_PTR(ary, ary_heap_alloc_buffer(capa));
         ARY_SET_HEAP_LEN(ary, 0);
     }
 
@@ -881,7 +902,33 @@ rb_ary_free(VALUE ary)
     }
 }
 
-RUBY_FUNC_EXPORTED size_t
+static VALUE fake_ary_flags;
+
+static VALUE
+init_fake_ary_flags(void)
+{
+    struct RArray fake_ary = {0};
+    fake_ary.basic.flags = T_ARRAY;
+    VALUE ary = (VALUE)&fake_ary;
+    RBASIC_SET_SHAPE_ID(ary, ROOT_SHAPE_ID | SHAPE_ID_LAYOUT_OTHER);
+    rb_ary_freeze(ary);
+    return fake_ary.basic.flags;
+}
+
+VALUE
+rb_setup_fake_ary(struct RArray *fake_ary, const VALUE *list, long len)
+{
+    fake_ary->basic.flags = fake_ary_flags;
+    RBASIC_CLEAR_CLASS((VALUE)fake_ary);
+
+    // bypass frozen checks
+    fake_ary->as.heap.ptr = list;
+    fake_ary->as.heap.len = len;
+    fake_ary->as.heap.aux.capa = len;
+    return (VALUE)fake_ary;
+}
+
+size_t
 rb_ary_memsize(VALUE ary)
 {
     if (ARY_OWNS_HEAP_P(ary)) {
@@ -904,9 +951,6 @@ ary_make_shared(VALUE ary)
         return ary;
     }
     else if (OBJ_FROZEN(ary)) {
-        if (!ARY_EMBED_P(ary)) {
-            ary_shrink_capa(ary);
-        }
         return ary;
     }
     else {
@@ -919,7 +963,7 @@ ary_make_shared(VALUE ary)
         FL_SET_SHARED_ROOT(shared);
 
         if (ARY_EMBED_P(ary)) {
-            VALUE *ptr = ary_heap_alloc(capa);
+            VALUE *ptr = ary_heap_alloc_buffer(capa);
             ARY_SET_PTR(shared, ptr);
             ary_memcpy(shared, 0, len, RARRAY_CONST_PTR(ary));
 
@@ -949,7 +993,7 @@ ary_make_substitution(VALUE ary)
 
     if (ary_embeddable_p(len)) {
         VALUE subst = rb_ary_new_capa(len);
-        assert(ARY_EMBED_P(subst));
+        RUBY_ASSERT(ARY_EMBED_P(subst));
 
         ary_memcpy(subst, 0, len, RARRAY_CONST_PTR(ary));
         ARY_SET_EMBED_LEN(subst, len);
@@ -995,14 +1039,18 @@ rb_to_array(VALUE ary)
  *  call-seq:
  *    Array.try_convert(object) -> object, new_array, or nil
  *
- *  If +object+ is an \Array object, returns +object+.
+ *  Attempts to return an array, based on the given +object+.
+ *
+ *  If +object+ is an array, returns +object+.
  *
- *  Otherwise if +object+ responds to <tt>:to_ary</tt>,
- *  calls <tt>object.to_ary</tt> and returns the result.
+ *  Otherwise if +object+ responds to <tt>:to_ary</tt>.
+ *  calls <tt>object.to_ary</tt>:
+ *  if the return value is an array or +nil+, returns that value;
+ *  if not, raises TypeError.
  *
- *  Returns +nil+ if +object+ does not respond to <tt>:to_ary</tt>
+ *  Otherwise returns +nil+.
  *
- *  Raises an exception unless <tt>object.to_ary</tt> returns an \Array object.
+ *  Related: see {Methods for Creating an Array}[rdoc-ref:Array@Methods+for+Creating+an+Array].
  */
 
 static VALUE
@@ -1039,48 +1087,51 @@ rb_ary_s_new(int argc, VALUE *argv, VALUE klass)
  *  call-seq:
  *    Array.new -> new_empty_array
  *    Array.new(array) -> new_array
- *    Array.new(size) -> new_array
- *    Array.new(size, default_value) -> new_array
- *    Array.new(size) {|index| ... } -> new_array
+ *    Array.new(size, default_value = nil) -> new_array
+ *    Array.new(size = 0) {|index| ... } -> new_array
  *
- *  Returns a new \Array.
+ *  Returns a new array.
  *
- *  With no block and no arguments, returns a new empty \Array object.
+ *  With no block and no argument given, returns a new empty array:
  *
- *  With no block and a single \Array argument +array+,
- *  returns a new \Array formed from +array+:
+ *    Array.new # => []
  *
- *    a = Array.new([:foo, 'bar', 2])
- *    a.class # => Array
- *    a # => [:foo, "bar", 2]
+ *  With no block and array argument given, returns a new array with the same elements:
+ *
+ *    Array.new([:foo, 'bar', 2]) # => [:foo, "bar", 2]
  *
- *  With no block and a single Integer argument +size+,
- *  returns a new \Array of the given size
- *  whose elements are all +nil+:
+ *  With no block and integer argument given, returns a new array containing
+ *  that many instances of the given +default_value+:
  *
- *    a = Array.new(3)
- *    a # => [nil, nil, nil]
+ *    Array.new(0)    # => []
+ *    Array.new(3)    # => [nil, nil, nil]
+ *    Array.new(2, 3) # => [3, 3]
  *
- *  With no block and arguments +size+ and +default_value+,
- *  returns an \Array of the given size;
- *  each element is that same +default_value+:
+ *  With a block given, returns an array of the given +size+;
+ *  calls the block with each +index+ in the range <tt>(0...size)</tt>;
+ *  the element at that +index+ in the returned array is the blocks return value:
  *
- *    a = Array.new(3, 'x')
- *    a # => ['x', 'x', 'x']
+ *    Array.new(3)  {|index| "Element #{index}" } # => ["Element 0", "Element 1", "Element 2"]
  *
- *  With a block and argument +size+,
- *  returns an \Array of the given size;
- *  the block is called with each successive integer +index+;
- *  the element for that +index+ is the return value from the block:
+ *  A common pitfall for new Rubyists is providing an expression as +default_value+:
  *
- *    a = Array.new(3) {|index| "Element #{index}" }
- *    a # => ["Element 0", "Element 1", "Element 2"]
+ *    array = Array.new(2, {})
+ *    array # => [{}, {}]
+ *    array[0][:a] = 1
+ *    array # => [{a: 1}, {a: 1}], as array[0] and array[1] are same object
  *
- *  Raises ArgumentError if +size+ is negative.
+ *  If you want the elements of the array to be distinct, you should pass a block:
  *
- *  With a block and no argument,
- *  or a single argument +0+,
- *  ignores the block and returns a new empty \Array.
+ *    array = Array.new(2) { {} }
+ *    array # => [{}, {}]
+ *    array[0][:a] = 1
+ *    array # => [{a: 1}, {}], as array[0] and array[1] are different objects
+ *
+ *  Raises TypeError if the first argument is not either an array
+ *  or an {integer-convertible object}[rdoc-ref:implicit_conversion.rdoc@Integer-Convertible+Objects]).
+ *  Raises ArgumentError if the first argument is a negative integer.
+ *
+ *  Related: see {Methods for Creating an Array}[rdoc-ref:Array@Methods+for+Creating+an+Array].
  */
 
 static VALUE
@@ -1092,8 +1143,8 @@ rb_ary_initialize(int argc, VALUE *argv, VALUE ary)
     rb_ary_modify(ary);
     if (argc == 0) {
         rb_ary_reset(ary);
-        assert(ARY_EMBED_P(ary));
-        assert(ARY_EMBED_LEN(ary) == 0);
+        RUBY_ASSERT(ARY_EMBED_P(ary));
+        RUBY_ASSERT(ARY_EMBED_LEN(ary) == 0);
         if (rb_block_given_p()) {
             rb_warning("given block not used");
         }
@@ -1138,11 +1189,13 @@ rb_ary_initialize(int argc, VALUE *argv, VALUE ary)
 }
 
 /*
- * Returns a new array populated with the given objects.
+ * Returns a new array, populated with the given objects:
+ *
+ *   Array[1, 'a', /^A/]    # => [1, "a", /^A/]
+ *   Array[]                # => []
+ *   Array.[](1, 'a', /^A/) # => [1, "a", /^A/]
  *
- *   Array.[]( 1, 'a', /^A/)  # => [1, "a", /^A/]
- *   Array[ 1, 'a', /^A/ ]    # => [1, "a", /^A/]
- *   [ 1, 'a', /^A/ ]         # => [1, "a", /^A/]
+ * Related: see {Methods for Creating an Array}[rdoc-ref:Array@Methods+for+Creating+an+Array].
  */
 
 static VALUE
@@ -1190,9 +1243,9 @@ rb_ary_store(VALUE ary, long idx, VALUE 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));
+    RUBY_ASSERT(offset >= 0);
+    RUBY_ASSERT(len >= 0);
+    RUBY_ASSERT(offset+len <= RARRAY_LEN(ary));
 
     VALUE result = ary_alloc_heap(klass);
     size_t embed_capa = ary_embed_capa(result);
@@ -1204,7 +1257,10 @@ ary_make_partial(VALUE ary, VALUE klass, long offset, long len)
     else {
         VALUE shared = ary_make_shared(ary);
 
-        assert(!ARY_EMBED_P(result));
+        /* The ary_make_shared call may allocate, which can trigger a GC
+         * compaction. This can cause the array to be embedded because it has
+         * a length of 0. */
+        FL_UNSET_EMBED(result);
 
         ARY_SET_PTR(result, RARRAY_CONST_PTR(ary));
         ARY_SET_LEN(result, RARRAY_LEN(ary));
@@ -1223,17 +1279,18 @@ ary_make_partial(VALUE ary, VALUE klass, long offset, long len)
 static VALUE
 ary_make_partial_step(VALUE ary, VALUE klass, long offset, long len, long step)
 {
-    assert(offset >= 0);
-    assert(len >= 0);
-    assert(offset+len <= RARRAY_LEN(ary));
-    assert(step != 0);
+    RUBY_ASSERT(offset >= 0);
+    RUBY_ASSERT(len >= 0);
+    RUBY_ASSERT(offset+len <= RARRAY_LEN(ary));
+    RUBY_ASSERT(step != 0);
 
-    const VALUE *values = RARRAY_CONST_PTR(ary);
     const long orig_len = len;
 
     if (step > 0 && step >= len) {
         VALUE result = ary_new(klass, 1);
         VALUE *ptr = (VALUE *)ARY_EMBED_PTR(result);
+        const VALUE *values = RARRAY_CONST_PTR(ary);
+
         RB_OBJ_WRITE(result, ptr, values[offset]);
         ARY_SET_EMBED_LEN(result, 1);
         return result;
@@ -1251,6 +1308,8 @@ ary_make_partial_step(VALUE ary, VALUE klass, long offset, long len, long step)
     VALUE result = ary_new(klass, len);
     if (ARY_EMBED_P(result)) {
         VALUE *ptr = (VALUE *)ARY_EMBED_PTR(result);
+        const VALUE *values = RARRAY_CONST_PTR(ary);
+
         for (i = 0; i < len; ++i) {
             RB_OBJ_WRITE(result, ptr+i, values[j]);
             j += step;
@@ -1258,6 +1317,8 @@ ary_make_partial_step(VALUE ary, VALUE klass, long offset, long len, long step)
         ARY_SET_EMBED_LEN(result, len);
     }
     else {
+        const VALUE *values = RARRAY_CONST_PTR(ary);
+
         RARRAY_PTR_USE(result, ptr, {
             for (i = 0; i < len; ++i) {
                 RB_OBJ_WRITE(result, ptr+i, values[j]);
@@ -1313,19 +1374,17 @@ ary_take_first_or_last(int argc, const VALUE *argv, VALUE ary, enum ary_take_pos
 
 /*
  *  call-seq:
- *    array << object -> self
+ *    self << object -> self
  *
- *  Appends +object+ to +self+; returns +self+:
+ *  Appends +object+ as the last element in +self+; returns +self+:
  *
- *    a = [:foo, 'bar', 2]
- *    a << :baz # => [:foo, "bar", 2, :baz]
+ *    [:foo, 'bar', 2] << :baz # => [:foo, "bar", 2, :baz]
  *
- *  Appends +object+ as one element, even if it is another \Array:
+ *  Appends +object+ as a single element, even if it is another array:
  *
- *    a = [:foo, 'bar', 2]
- *    a1 = a << [3, 4]
- *    a1 # => [:foo, "bar", 2, [3, 4]]
+ *    [:foo, 'bar', 2] << [3, 4] # => [:foo, "bar", 2, [3, 4]]
  *
+ *  Related: see {Methods for Assigning}[rdoc-ref:Array@Methods+for+Assigning].
  */
 
 VALUE
@@ -1353,22 +1412,20 @@ rb_ary_cat(VALUE ary, const VALUE *argv, long len)
 
 /*
  *  call-seq:
- *    array.push(*objects) -> self
+ *    push(*objects) -> self
+ *    append(*objects) -> self
  *
- *  Appends trailing elements.
+ *  Appends each argument in +objects+ to +self+; returns +self+:
  *
- *  Appends each argument in +objects+ to +self+;  returns +self+:
+ *    a = [:foo, 'bar', 2] # => [:foo, "bar", 2]
+ *    a.push(:baz, :bat)   # => [:foo, "bar", 2, :baz, :bat]
  *
- *    a = [:foo, 'bar', 2]
- *    a.push(:baz, :bat) # => [:foo, "bar", 2, :baz, :bat]
+ *  Appends each argument as a single element, even if it is another array:
  *
- *  Appends each argument as one element, even if it is another \Array:
+ *    a = [:foo, 'bar', 2]               # => [:foo, "bar", 2]
+      a.push([:baz, :bat], [:bam, :bad]) # => [:foo, "bar", 2, [:baz, :bat], [:bam, :bad]]
  *
- *    a = [:foo, 'bar', 2]
- *    a1 = a.push([:baz, :bat], [:bam, :bad])
- *    a1 # => [:foo, "bar", 2, [:baz, :bat], [:bam, :bad]]
- *
- *  Related: #pop, #shift, #unshift.
+ *  Related: see {Methods for Assigning}[rdoc-ref:Array@Methods+for+Assigning].
  */
 
 static VALUE
@@ -1390,41 +1447,42 @@ rb_ary_pop(VALUE ary)
     {
         ary_resize_capa(ary, n * 2);
     }
-    --n;
-    ARY_SET_LEN(ary, n);
+
+    VALUE obj = RARRAY_AREF(ary, n - 1);
+
+    ARY_SET_LEN(ary, n - 1);
     ary_verify(ary);
-    return RARRAY_AREF(ary, n);
+    return obj;
 }
 
 /*
  *  call-seq:
- *    array.pop -> object or nil
- *    array.pop(n) -> new_array
+ *    pop -> object or nil
+ *    pop(count) -> new_array
  *
- *  Removes and returns trailing elements.
+ *  Removes and returns trailing elements of +self+.
  *
- *  When no argument is given and +self+ is not empty,
- *  removes and returns the last element:
+ *  With no argument given, removes and returns the last element, if available;
+ *  otherwise returns +nil+:
  *
  *    a = [:foo, 'bar', 2]
- *    a.pop # => 2
- *    a # => [:foo, "bar"]
+ *    a.pop  # => 2
+ *    a      # => [:foo, "bar"]
+ *    [].pop # => nil
  *
- *  Returns +nil+ if the array is empty.
+ *  With non-negative integer argument +count+ given,
+ *  returns a new array containing the trailing +count+ elements of +self+, as available:
  *
- *  When a non-negative Integer argument +n+ is given and is in range,
- *
- *  removes and returns the last +n+ elements in a new \Array:
  *    a = [:foo, 'bar', 2]
  *    a.pop(2) # => ["bar", 2]
- *
- *  If +n+ is positive and out of range,
- *  removes and returns all elements:
+ *    a        # => [:foo]
  *
  *    a = [:foo, 'bar', 2]
  *    a.pop(50) # => [:foo, "bar", 2]
+ *    a         # => []
  *
- *  Related: #push, #shift, #unshift.
+ *  Related: Array#push;
+ *  see also {Methods for Deleting}[rdoc-ref:Array@Methods+for+Deleting].
  */
 
 static VALUE
@@ -1463,35 +1521,40 @@ rb_ary_shift(VALUE ary)
 
 /*
  *  call-seq:
- *     array.shift -> object or nil
- *     array.shift(n) -> new_array
- *
- *  Removes and returns leading elements.
- *
- *  When no argument is given, removes and returns the first element:
+ *    shift -> object or nil
+ *    shift(count) -> new_array or nil
  *
- *    a = [:foo, 'bar', 2]
- *    a.shift # => :foo
- *    a # => ['bar', 2]
+ *  Removes and returns leading elements from +self+.
  *
- *  Returns +nil+ if +self+ is empty.
+ *  With no argument, removes and returns one element, if available,
+ *  or +nil+ otherwise:
  *
- *  When positive Integer argument +n+ is given, removes the first +n+ elements;
- *  returns those elements in a new \Array:
+ *    a = [0, 1, 2, 3]
+ *    a.shift  # => 0
+ *    a        # => [1, 2, 3]
+ *    [].shift # => nil
  *
- *    a = [:foo, 'bar', 2]
- *    a.shift(2) # => [:foo, 'bar']
- *    a # => [2]
+ *  With non-negative numeric argument +count+ given,
+ *  removes and returns the first +count+ elements:
  *
- *  If +n+ is as large as or larger than <tt>self.length</tt>,
- *  removes all elements; returns those elements in a new \Array:
+ *    a = [0, 1, 2, 3]
+ *    a.shift(2)   # => [0, 1]
+ *    a            # => [2, 3]
+ *    a.shift(1.1) # => [2]
+ *    a            # => [3]
+ *    a.shift(0)   # => []
+ *    a            # => [3]
+ *
+ *  If +count+ is large,
+ *  removes and returns all elements:
  *
- *    a = [:foo, 'bar', 2]
- *    a.shift(3) # => [:foo, 'bar', 2]
+ *    a = [0, 1, 2, 3]
+ *    a.shift(50) # => [0, 1, 2, 3]
+ *    a           # => []
  *
- *  If +n+ is zero, returns a new empty \Array; +self+ is unmodified.
+ *  If +self+ is empty, returns a new empty array.
  *
- *  Related: #push, #pop, #unshift.
+ *  Related: see {Methods for Deleting}[rdoc-ref:Array@Methods+for+Deleting].
  */
 
 static VALUE
@@ -1556,7 +1619,7 @@ make_room_for_unshift(VALUE ary, const VALUE *head, VALUE *sharedp, int argc, lo
         head = sharedp + argc + room;
     }
     ARY_SET_PTR(ary, head - argc);
-    assert(ARY_SHARED_ROOT_OCCUPIED(ARY_SHARED_ROOT(ary)));
+    RUBY_ASSERT(ARY_SHARED_ROOT_OCCUPIED(ARY_SHARED_ROOT(ary)));
 
     ary_verify(ary);
     return ARY_SHARED_ROOT(ary);
@@ -1632,14 +1695,16 @@ ary_ensure_room_for_unshift(VALUE ary, int argc)
 
 /*
  *  call-seq:
- *    array.unshift(*objects) -> self
+ *    unshift(*objects) -> self
+ *    prepend(*objects) -> self
  *
  *  Prepends the given +objects+ to +self+:
  *
  *    a = [:foo, 'bar', 2]
  *    a.unshift(:bam, :bat) # => [:bam, :bat, :foo, "bar", 2]
  *
- *  Related: #push, #pop, #shift.
+ *  Related: Array#shift;
+ *  see also {Methods for Assigning}[rdoc-ref:Array@Methods+for+Assigning].
  */
 
 VALUE
@@ -1715,25 +1780,38 @@ static VALUE rb_ary_aref2(VALUE ary, VALUE b, VALUE e);
 
 /*
  *  call-seq:
- *    array[index] -> object or nil
- *    array[start, length] -> object or nil
- *    array[range] -> object or nil
- *    array[aseq] -> object or nil
- *    array.slice(index) -> object or nil
- *    array.slice(start, length) -> object or nil
- *    array.slice(range) -> object or nil
- *    array.slice(aseq) -> object or nil
+ *    self[offset] -> object or nil
+ *    self[offset, size] -> object or nil
+ *    self[range] -> object or nil
+ *    self[aseq] -> object or nil
  *
  *  Returns elements from +self+; does not modify +self+.
  *
- *  When a single Integer argument +index+ is given, returns the element at offset +index+:
+ *  In brief:
+ *
+ *    a = [:foo, 'bar', 2]
+ *
+ *    # Single argument offset: returns one element.
+ *    a[0]     # => :foo          # Zero-based index.
+ *    a[-1]    # => 2             # Negative index counts backwards from end.
+ *
+ *    # Arguments offset and size: returns an array.
+ *    a[1, 2]  # => ["bar", 2]
+ *    a[-2, 2] # => ["bar", 2]    # Negative offset counts backwards from end.
+ *
+ *    # Single argument range: returns an array.
+ *    a[0..1]  # => [:foo, "bar"]
+ *    a[0..-2] # => [:foo, "bar"] # Negative range-begin counts backwards from end.
+ *    a[-2..2] # => ["bar", 2]    # Negative range-end counts backwards from end.
+ *
+ *  When a single integer argument +offset+ is given, returns the element at offset +offset+:
  *
  *    a = [:foo, 'bar', 2]
  *    a[0] # => :foo
  *    a[2] # => 2
  *    a # => [:foo, "bar", 2]
  *
- *  If +index+ is negative, counts relative to the end of +self+:
+ *  If +offset+ is negative, counts backwards from the end of +self+:
  *
  *    a = [:foo, 'bar', 2]
  *    a[-1] # => 2
@@ -1741,35 +1819,35 @@ static VALUE rb_ary_aref2(VALUE ary, VALUE b, VALUE e);
  *
  *  If +index+ is out of range, returns +nil+.
  *
- *  When two Integer arguments +start+ and +length+ are given,
- *  returns a new \Array of size +length+ containing successive elements beginning at offset +start+:
+ *  When two Integer arguments +offset+ and +size+ are given,
+ *  returns a new array of size +size+ containing successive elements beginning at offset +offset+:
  *
  *    a = [:foo, 'bar', 2]
  *    a[0, 2] # => [:foo, "bar"]
  *    a[1, 2] # => ["bar", 2]
  *
- *  If <tt>start + length</tt> is greater than <tt>self.length</tt>,
- *  returns all elements from offset +start+ to the end:
+ *  If <tt>offset + size</tt> is greater than <tt>self.size</tt>,
+ *  returns all elements from offset +offset+ to the end:
  *
  *    a = [:foo, 'bar', 2]
  *    a[0, 4] # => [:foo, "bar", 2]
  *    a[1, 3] # => ["bar", 2]
  *    a[2, 2] # => [2]
  *
- *  If <tt>start == self.size</tt> and <tt>length >= 0</tt>,
- *  returns a new empty \Array.
+ *  If <tt>offset == self.size</tt> and <tt>size >= 0</tt>,
+ *  returns a new empty array.
  *
- *  If +length+ is negative, returns +nil+.
+ *  If +size+ is negative, returns +nil+.
  *
  *  When a single Range argument +range+ is given,
- *  treats <tt>range.min</tt> as +start+ above
- *  and <tt>range.size</tt> as +length+ above:
+ *  treats <tt>range.min</tt> as +offset+ above
+ *  and <tt>range.size</tt> as +size+ above:
  *
  *    a = [:foo, 'bar', 2]
  *    a[0..1] # => [:foo, "bar"]
  *    a[1..2] # => ["bar", 2]
  *
- *  Special case: If <tt>range.start == a.size</tt>, returns a new empty \Array.
+ *  Special case: If <tt>range.start == a.size</tt>, returns a new empty array.
  *
  *  If <tt>range.end</tt> is negative, calculates the end index from the end:
  *
@@ -1793,7 +1871,7 @@ static VALUE rb_ary_aref2(VALUE ary, VALUE b, VALUE e);
  *    a[4..-1] # => nil
  *
  *  When a single Enumerator::ArithmeticSequence argument +aseq+ is given,
- *  returns an \Array of elements corresponding to the indexes produced by
+ *  returns an array of elements corresponding to the indexes produced by
  *  the sequence.
  *
  *    a = ['--', 'data1', '--', 'data2', '--', 'data3']
@@ -1815,6 +1893,7 @@ static VALUE rb_ary_aref2(VALUE ary, VALUE b, VALUE e);
  *    # Raises TypeError (no implicit conversion of Symbol into Integer):
  *    a[:foo]
  *
+ *  Related: see {Methods for Fetching}[rdoc-ref:Array@Methods+for+Fetching].
  */
 
 VALUE
@@ -1862,13 +1941,26 @@ rb_ary_aref1(VALUE ary, VALUE arg)
 
 /*
  *  call-seq:
- *    array.at(index) -> object
+ *    at(index) -> object or nil
+ *
+ *  Returns the element of +self+ specified by the given +index+
+ *  or +nil+ if there is no such element;
+ *  +index+ must be an
+ *  {integer-convertible object}[rdoc-ref:implicit_conversion.rdoc@Integer-Convertible+Objects].
+ *
+ *  For non-negative +index+, returns the element of +self+ at offset +index+:
  *
- *  Returns the element at Integer offset +index+; does not modify +self+.
  *    a = [:foo, 'bar', 2]
- *    a.at(0) # => :foo
- *    a.at(2) # => 2
+ *    a.at(0)   # => :foo
+ *    a.at(2)   # => 2
+ *    a.at(2.0) # => 2
+ *
+ *  For negative +index+, counts backwards from the end of +self+:
  *
+ *    a.at(-2) # => "bar"
+ *
+ *  Related: Array#[];
+ *  see also {Methods for Fetching}[rdoc-ref:Array@Methods+for+Fetching].
  */
 
 VALUE
@@ -1917,17 +2009,19 @@ rb_ary_last(int argc, const VALUE *argv, VALUE ary) // used by parse.y
 
 /*
  *  call-seq:
- *    array.fetch(index) -> element
- *    array.fetch(index, default_value) -> element
- *    array.fetch(index) {|index| ... } -> element
+ *    fetch(index) -> element
+ *    fetch(index, default_value) -> element or default_value
+ *    fetch(index) {|index| ... } -> element or block_return_value
  *
- *  Returns the element at offset  +index+.
+ *  Returns the element of +self+ at offset +index+ if +index+ is in range; +index+ must be an
+ *  {integer-convertible object}[rdoc-ref:implicit_conversion.rdoc@Integer-Convertible+Objects].
  *
- *  With the single Integer argument +index+,
+ *  With the single argument +index+ and no block,
  *  returns the element at offset +index+:
  *
  *    a = [:foo, 'bar', 2]
- *    a.fetch(1) # => "bar"
+ *    a.fetch(1)   # => "bar"
+ *    a.fetch(1.1) # => "bar"
  *
  *  If +index+ is negative, counts from the end of the array:
  *
@@ -1935,12 +2029,12 @@ rb_ary_last(int argc, const VALUE *argv, VALUE ary) // used by parse.y
  *    a.fetch(-1) # => 2
  *    a.fetch(-2) # => "bar"
  *
- *  With arguments +index+ and +default_value+,
- *  returns the element at offset +index+ if index is in range,
- *  otherwise returns +default_value+:
+ *  With arguments +index+ and +default_value+ (which may be any object) and no block,
+ *  returns +default_value+ if +index+ is out-of-range:
  *
  *    a = [:foo, 'bar', 2]
- *    a.fetch(1, nil) # => "bar"
+ *    a.fetch(1, nil)  # => "bar"
+ *    a.fetch(3, :foo) # => :foo
  *
  *  With argument +index+ and a block,
  *  returns the element at offset +index+ if index is in range
@@ -1950,6 +2044,7 @@ rb_ary_last(int argc, const VALUE *argv, VALUE ary) // used by parse.y
  *    a.fetch(1) {|index| raise 'Cannot happen' } # => "bar"
  *    a.fetch(50) {|index| "Value for #{index}" } # => "Value for 50"
  *
+ *  Related: see {Methods for Fetching}[rdoc-ref:Array@Methods+for+Fetching].
  */
 
 static VALUE
@@ -1981,14 +2076,106 @@ rb_ary_fetch(int argc, VALUE *argv, VALUE ary)
 }
 
 /*
+ * call-seq:
+ *   find(if_none_proc = nil) {|element| ... } -> object or nil
+ *   find(if_none_proc = nil) -> enumerator
+ *
+ * Returns the first element for which the block returns a truthy value.
+ *
+ * With a block given, calls the block with successive elements of the array;
+ * returns the first element for which the block returns a truthy value:
+ *
+ *   [1, 3, 5].find {|element| element > 2}                # => 3
+ *
+ * If no such element is found, calls +if_none_proc+ and returns its return value.
+ *
+ *   [1, 3, 5].find(proc {-1}) {|element| element > 12} # => -1
+ *
+ * With no block given, returns an Enumerator.
+ *
+ */
+
+static VALUE
+rb_ary_find(int argc, VALUE *argv, VALUE ary)
+{
+    VALUE if_none;
+    long idx;
+
+    RETURN_ENUMERATOR(ary, argc, argv);
+    if_none = rb_check_arity(argc, 0, 1) ? argv[0] : Qnil;
+
+    for (idx = 0; idx < RARRAY_LEN(ary); idx++) {
+        VALUE elem = RARRAY_AREF(ary, idx);
+        if (RTEST(rb_yield(elem))) {
+            return elem;
+        }
+    }
+
+    if (!NIL_P(if_none)) {
+        return rb_funcallv(if_none, idCall, 0, 0);
+    }
+    return Qnil;
+}
+
+/*
+ * call-seq:
+ *   rfind(if_none_proc = nil) {|element| ... } -> object or nil
+ *   rfind(if_none_proc = nil) -> enumerator
+ *
+ * Returns the last element for which the block returns a truthy value.
+ *
+ * With a block given, calls the block with successive elements of the array in
+ * reverse order; returns the first element for which the block returns a truthy
+ * value:
+ *
+ *   [1, 2, 3, 4, 5, 6].rfind {|element| element < 5}       # => 4
+ *
+ * If no such element is found, calls +if_none_proc+ and returns its return value.
+ *
+ *   [1, 2, 3, 4].rfind(proc {0}) {|element| element < -2}  # => 0
+ *
+ * With no block given, returns an Enumerator.
+ *
+ */
+
+static VALUE
+rb_ary_rfind(int argc, VALUE *argv, VALUE ary)
+{
+    VALUE if_none;
+    long len, idx;
+
+    RETURN_ENUMERATOR(ary, argc, argv);
+    if_none = rb_check_arity(argc, 0, 1) ? argv[0] : Qnil;
+
+    idx = RARRAY_LEN(ary);
+    while (idx--) {
+        VALUE elem = RARRAY_AREF(ary, idx);
+        if (RTEST(rb_yield(elem))) {
+            return elem;
+        }
+
+        len = RARRAY_LEN(ary);
+        idx = (idx >= len) ? len : idx;
+    }
+
+    if (!NIL_P(if_none)) {
+        return rb_funcallv(if_none, idCall, 0, 0);
+    }
+    return Qnil;
+}
+
+/*
  *  call-seq:
- *    array.index(object) -> integer or nil
- *    array.index {|element| ... } -> integer or nil
- *    array.index -> new_enumerator
+ *    find_index(object) -> integer or nil
+ *    find_index {|element| ... } -> integer or nil
+ *    find_index -> new_enumerator
+ *    index(object) -> integer or nil
+ *    index {|element| ... } -> integer or nil
+ *    index -> new_enumerator
  *
- *  Returns the index of a specified element.
+ *  Returns the zero-based integer index of a specified element, or +nil+.
  *
- *  When argument +object+ is given but no block,
+ *  With only argument +object+ given,
  *  returns the index of the first element +element+
  *  for which <tt>object == element</tt>:
  *
@@ -1997,7 +2184,7 @@ rb_ary_fetch(int argc, VALUE *argv, VALUE ary)
  *
  *  Returns +nil+ if no such element found.
  *
- *  When both argument +object+ and a block are given,
+ *  With only a block given,
  *  calls the block with each successive element;
  *  returns the index of the first element for which the block returns a truthy value:
  *
@@ -2006,14 +2193,9 @@ rb_ary_fetch(int argc, VALUE *argv, VALUE ary)
  *
  *  Returns +nil+ if the block never returns a truthy value.
  *
- *  When neither an argument nor a block is given, returns a new Enumerator:
- *
- *    a = [:foo, 'bar', 2]
- *    e = a.index
- *    e # => #<Enumerator: [:foo, "bar", 2]:index>
- *    e.each {|element| element == 'bar' } # => 1
+ *  With neither an argument nor a block given, returns a new Enumerator.
  *
- *  Related: #rindex.
+ *  Related: see {Methods for Querying}[rdoc-ref:Array@Methods+for+Querying].
  */
 
 static VALUE
@@ -2046,20 +2228,20 @@ rb_ary_index(int argc, VALUE *argv, VALUE ary)
 
 /*
  *  call-seq:
- *    array.rindex(object) -> integer or nil
- *    array.rindex {|element| ... } -> integer or nil
- *    array.rindex -> new_enumerator
+ *    rindex(object) -> integer or nil
+ *    rindex {|element| ... } -> integer or nil
+ *    rindex -> new_enumerator
  *
  *  Returns the index of the last element for which <tt>object == element</tt>.
  *
- *  When argument +object+ is given but no block, returns the index of the last such element found:
+ *  With argument +object+ given, returns the index of the last such element found:
  *
  *    a = [:foo, 'bar', 2, 'bar']
  *    a.rindex('bar') # => 3
  *
  *  Returns +nil+ if no such object found.
  *
- *  When a block is given but no argument, calls the block with each successive element;
+ *  With a block given, calls the block with each successive element;
  *  returns the index of the last element for which the block returns a truthy value:
  *
  *    a = [:foo, 'bar', 2, 'bar']
@@ -2067,14 +2249,9 @@ rb_ary_index(int argc, VALUE *argv, VALUE ary)
  *
  *  Returns +nil+ if the block never returns a truthy value.
  *
- *  When neither an argument nor a block is given, returns a new Enumerator:
+ *  When neither an argument nor a block is given, returns a new Enumerator.
  *
- *    a = [:foo, 'bar', 2, 'bar']
- *    e = a.rindex
- *    e # => #<Enumerator: [:foo, "bar", 2, "bar"]:rindex>
- *    e.each {|element| element == 'bar' } # => 3
- *
- *  Related: #index.
+ *  Related: see {Methods for Querying}[rdoc-ref:Array@Methods+for+Querying].
  */
 
 static VALUE
@@ -2221,7 +2398,7 @@ rb_ary_resize(VALUE ary, long len)
         rb_raise(rb_eIndexError, "index %ld too big", len);
     }
     if (len > olen) {
-        if (len >= ARY_CAPA(ary)) {
+        if (len > ARY_CAPA(ary)) {
             ary_double_capa(ary, len);
         }
         ary_mem_clear(ary, olen, len - olen);
@@ -2240,7 +2417,7 @@ rb_ary_resize(VALUE ary, long len)
         MEMCPY((VALUE *)ARY_EMBED_PTR(ary), ptr, VALUE, len); /* WB: no new reference */
         ARY_SET_EMBED_LEN(ary, len);
 
-        if (is_malloc_ptr) ruby_sized_xfree((void *)ptr, ptr_capa);
+        if (is_malloc_ptr) ruby_xfree_sized((void *)ptr, ptr_capa);
     }
     else {
         if (olen > len + ARY_DEFAULT_SIZE) {
@@ -2271,11 +2448,39 @@ ary_aset_by_rb_ary_splice(VALUE ary, long beg, long len, VALUE val)
 
 /*
  *  call-seq:
- *    array[index] = object -> object
- *    array[start, length] = object -> object
- *    array[range] = object -> object
- *
- *  Assigns elements in +self+; returns the given +object+.
+ *    self[index] = object -> object
+ *    self[start, length] = object -> object
+ *    self[range] = object -> object
+ *
+ *  Assigns elements in +self+, based on the given +object+; returns +object+.
+ *
+ *  In brief:
+ *
+ *      a_orig = [:foo, 'bar', 2]
+ *
+ *      # With argument index.
+ *      a = a_orig.dup
+ *      a[0] = 'foo' # => "foo"
+ *      a # => ["foo", "bar", 2]
+ *      a = a_orig.dup
+ *      a[7] = 'foo' # => "foo"
+ *      a # => [:foo, "bar", 2, nil, nil, nil, nil, "foo"]
+ *
+ *      # With arguments start and length.
+ *      a = a_orig.dup
+ *      a[0, 2] = 'foo' # => "foo"
+ *      a # => ["foo", 2]
+ *      a = a_orig.dup
+ *      a[6, 50] = 'foo' # => "foo"
+ *      a # => [:foo, "bar", 2, nil, nil, nil, "foo"]
+ *
+ *      # With argument range.
+ *      a = a_orig.dup
+ *      a[0..1] = 'foo' # => "foo"
+ *      a # => ["foo", 2]
+ *      a = a_orig.dup
+ *      a[6..50] = 'foo' # => "foo"
+ *      a # => [:foo, "bar", 2, nil, nil, nil, "foo"]
  *
  *  When Integer argument +index+ is given, assigns +object+ to an element in +self+.
  *
@@ -2297,7 +2502,7 @@ ary_aset_by_rb_ary_splice(VALUE ary, long beg, long len, VALUE val)
  *    a[-1] = 'two' # => "two"
  *    a # => [:foo, "bar", "two"]
  *
- *  When Integer arguments +start+ and +length+ are given and +object+ is not an \Array,
+ *  When Integer arguments +start+ and +length+ are given and +object+ is not an array,
  *  removes <tt>length - 1</tt> elements beginning at offset +start+,
  *  and assigns +object+ at offset +start+:
  *
@@ -2332,7 +2537,7 @@ ary_aset_by_rb_ary_splice(VALUE ary, long beg, long len, VALUE val)
  *    a[1, 5] = 'foo' # => "foo"
  *    a # => [:foo, "foo"]
  *
- *  When Range argument +range+ is given and +object+ is an \Array,
+ *  When Range argument +range+ is given and +object+ is not an array,
  *  removes <tt>length - 1</tt> elements beginning at offset +start+,
  *  and assigns +object+ at offset +start+:
  *
@@ -2347,7 +2552,8 @@ ary_aset_by_rb_ary_splice(VALUE ary, long beg, long len, VALUE val)
  *    a # => [:foo, "foo"]
  *
  *  If the array length is less than <tt>range.begin</tt>,
- *  assigns +object+ at offset <tt>range.begin</tt>, and ignores +length+:
+ *  extends the array with +nil+, assigns +object+ at offset <tt>range.begin</tt>,
+ *  and ignores +length+:
  *
  *    a = [:foo, 'bar', 2]
  *    a[6..50] = 'foo' # => "foo"
@@ -2381,6 +2587,7 @@ ary_aset_by_rb_ary_splice(VALUE ary, long beg, long len, VALUE val)
  *    a[1..5] = 'foo' # => "foo"
  *    a # => [:foo, "foo"]
  *
+ *  Related: see {Methods for Assigning}[rdoc-ref:Array@Methods+for+Assigning].
  */
 
 static VALUE
@@ -2410,38 +2617,38 @@ rb_ary_aset(int argc, VALUE *argv, VALUE ary)
 
 /*
  *  call-seq:
- *    array.insert(index, *objects) -> self
+ *    insert(index, *objects) -> self
  *
- *  Inserts given +objects+ before or after the element at Integer index +offset+;
+ *  Inserts the given +objects+ as elements of +self+;
  *  returns +self+.
  *
- *  When +index+ is non-negative, inserts all given +objects+
- *  before the element at offset +index+:
+ *  When +index+ is non-negative, inserts +objects+
+ *  _before_ the element at offset +index+:
  *
- *    a = [:foo, 'bar', 2]
- *    a.insert(1, :bat, :bam) # => [:foo, :bat, :bam, "bar", 2]
+ *    a = ['a', 'b', 'c']     # => ["a", "b", "c"]
+ *    a.insert(1, :x, :y, :z) # => ["a", :x, :y, :z, "b", "c"]
  *
  *  Extends the array if +index+ is beyond the array (<tt>index >= self.size</tt>):
  *
- *    a = [:foo, 'bar', 2]
- *    a.insert(5, :bat, :bam)
- *    a # => [:foo, "bar", 2, nil, nil, :bat, :bam]
+ *    a = ['a', 'b', 'c']     # => ["a", "b", "c"]
+ *    a.insert(5, :x, :y, :z) # => ["a", "b", "c", nil, nil, :x, :y, :z]
  *
- *  Does nothing if no objects given:
+ *  When +index+ is negative, inserts +objects+
+ *  _after_ the element at offset <tt>index + self.size</tt>:
  *
- *    a = [:foo, 'bar', 2]
- *    a.insert(1)
- *    a.insert(50)
- *    a.insert(-50)
- *    a # => [:foo, "bar", 2]
+ *    a = ['a', 'b', 'c']      # => ["a", "b", "c"]
+ *    a.insert(-2, :x, :y, :z) # => ["a", "b", :x, :y, :z, "c"]
  *
- *  When +index+ is negative, inserts all given +objects+
- *  _after_ the element at offset <tt>index+self.size</tt>:
+ *  With no +objects+ given, does nothing:
  *
- *    a = [:foo, 'bar', 2]
- *    a.insert(-2, :bat, :bam)
- *    a # => [:foo, "bar", :bat, :bam, 2]
+ *    a = ['a', 'b', 'c'] # => ["a", "b", "c"]
+ *    a.insert(1)         # => ["a", "b", "c"]
+ *    a.insert(50)        # => ["a", "b", "c"]
+ *    a.insert(-50)       # => ["a", "b", "c"]
  *
+ *  Raises IndexError if +objects+ are given and +index+ is negative and out of range.
+ *
+ *  Related: see {Methods for Assigning}[rdoc-ref:Array@Methods+for+Assigning].
  */
 
 static VALUE
@@ -2477,14 +2684,48 @@ ary_enum_length(VALUE ary, VALUE args, VALUE eobj)
     return rb_ary_length(ary);
 }
 
+// These array primitives enable tight compatibility with the C implementation
+// in terms of what method calls happen. They can use unchecked utilities such as
+// FIX2LONG since unlike userland Ruby code, these methods cannot be traced with
+// TracePoint (or ruby/debug.h APIs) and have their local variables changed from
+// underneath them.
+
+// Return true if the index is at or past the end of the array.
+VALUE
+rb_jit_ary_at_end(rb_execution_context_t *ec, VALUE self, VALUE index)
+{
+    return FIX2LONG(index) >= RARRAY_LEN(self) ? Qtrue : Qfalse;
+}
+
+// Return the element at the given fixnum index.
+VALUE
+rb_jit_ary_at(rb_execution_context_t *ec, VALUE self, VALUE index)
+{
+    return RARRAY_AREF(self, FIX2LONG(index));
+}
+
+// Increment a fixnum by 1.
+VALUE
+rb_jit_fixnum_inc(rb_execution_context_t *ec, VALUE self, VALUE num)
+{
+    return LONG2FIX(FIX2LONG(num) + 1);
+}
+
+// Push a value onto an array and return the value.
+VALUE
+rb_jit_ary_push(rb_execution_context_t *ec, VALUE self, VALUE ary, VALUE val)
+{
+    rb_ary_push(ary, val);
+    return val;
+}
+
 /*
  *  call-seq:
- *    array.each {|element| ... } -> self
- *    array.each -> Enumerator
+ *    each {|element| ... } -> self
+ *    each -> new_enumerator
  *
- *  Iterates over array elements.
- *
- *  When a block given, passes each successive array element to the block;
+ *  With a block given, iterates over the elements of +self+,
+ *  passing each element to the block;
  *  returns +self+:
  *
  *    a = [:foo, 'bar', 2]
@@ -2506,20 +2747,9 @@ ary_enum_length(VALUE ary, VALUE args, VALUE eobj)
  *    foo
  *    bar
  *
- *  When no block given, returns a new Enumerator:
- *    a = [:foo, 'bar', 2]
- *
- *    e = a.each
- *    e # => #<Enumerator: [:foo, "bar", 2]:each>
- *    a1 = e.each {|element|  puts "#{element.class} #{element}" }
- *
- *  Output:
- *
- *    Symbol foo
- *    String bar
- *    Integer 2
+ *  With no block given, returns a new Enumerator.
  *
- *  Related: #each_index, #reverse_each.
+ *  Related: see {Methods for Iterating}[rdoc-ref:Array@Methods+for+Iterating].
  */
 
 VALUE
@@ -2536,12 +2766,11 @@ rb_ary_each(VALUE ary)
 
 /*
  *  call-seq:
- *    array.each_index {|index| ... } -> self
- *    array.each_index -> Enumerator
- *
- *  Iterates over array indexes.
+ *    each_index {|index| ... } -> self
+ *    each_index -> new_enumerator
  *
- *  When a block given, passes each successive array index to the block;
+ *  With a block given, iterates over the elements of +self+,
+ *  passing each <i>array index</i> to the block;
  *  returns +self+:
  *
  *    a = [:foo, 'bar', 2]
@@ -2557,26 +2786,16 @@ rb_ary_each(VALUE ary)
  *
  *    a = [:foo, 'bar', 2]
  *    a.each_index {|index| puts index; a.clear if index > 0 }
+ *    a # => []
  *
  *  Output:
  *
  *    0
  *    1
  *
- *  When no block given, returns a new Enumerator:
+ *  With no block given, returns a new Enumerator.
  *
- *    a = [:foo, 'bar', 2]
- *    e = a.each_index
- *    e # => #<Enumerator: [:foo, "bar", 2]:each_index>
- *    a1 = e.each {|index|  puts "#{index} #{a[index]}"}
- *
- *  Output:
- *
- *    0 foo
- *    1 bar
- *    2 2
- *
- *  Related: #each, #reverse_each.
+ *  Related: see {Methods for Iterating}[rdoc-ref:Array@Methods+for+Iterating].
  */
 
 static VALUE
@@ -2593,47 +2812,26 @@ rb_ary_each_index(VALUE ary)
 
 /*
  *  call-seq:
- *    array.reverse_each {|element| ... } -> self
- *    array.reverse_each -> Enumerator
+ *    reverse_each {|element| ... } -> self
+ *    reverse_each -> Enumerator
  *
- *  Iterates backwards over array elements.
- *
- *  When a block given, passes, in reverse order, each element to the block;
+ *  When a block given, iterates backwards over the elements of +self+,
+ *  passing, in reverse order, each element to the block;
  *  returns +self+:
  *
- *    a = [:foo, 'bar', 2]
- *    a.reverse_each {|element|  puts "#{element.class} #{element}" }
- *
- *  Output:
- *
- *    Integer 2
- *    String bar
- *    Symbol foo
+ *    a = []
+ *    [0, 1, 2].reverse_each {|element| a.push(element) }
+ *    a # => [2, 1, 0]
  *
  *  Allows the array to be modified during iteration:
  *
- *    a = [:foo, 'bar', 2]
- *    a.reverse_each {|element| puts element; a.clear if element.to_s.start_with?('b') }
- *
- *  Output:
+ *    a = ['a', 'b', 'c']
+ *    a.reverse_each {|element| a.clear if element.start_with?('b') }
+ *    a # => []
  *
- *    2
- *    bar
- *
- *  When no block given, returns a new Enumerator:
- *
- *    a = [:foo, 'bar', 2]
- *    e = a.reverse_each
- *    e # => #<Enumerator: [:foo, "bar", 2]:reverse_each>
- *    a1 = e.each {|element|  puts "#{element.class} #{element}" }
+ *  When no block given, returns a new Enumerator.
  *
- *  Output:
- *
- *    Integer 2
- *    String bar
- *    Symbol foo
- *
- *  Related: #each, #each_index.
+ *  Related: see {Methods for Iterating}[rdoc-ref:Array@Methods+for+Iterating].
  */
 
 static VALUE
@@ -2656,9 +2854,15 @@ rb_ary_reverse_each(VALUE ary)
 
 /*
  *  call-seq:
- *    array.length -> an_integer
+ *    length -> integer
+ *    size -> integer
+ *
+ *  Returns the count of elements in +self+:
+ *
+ *    [0, 1, 2].length # => 3
+ *    [].length        # => 0
  *
- *  Returns the count of elements in +self+.
+ *  Related: see {Methods for Querying}[rdoc-ref:Array@Methods+for+Querying].
  */
 
 static VALUE
@@ -2670,10 +2874,12 @@ rb_ary_length(VALUE ary)
 
 /*
  *  call-seq:
- *    array.empty?  -> true or false
+ *    empty?  -> true or false
  *
  *  Returns +true+ if the count of elements in +self+ is zero,
  *  +false+ otherwise.
+ *
+ *  Related: see {Methods for Querying}[rdoc-ref:Array@Methods+for+Querying].
  */
 
 static VALUE
@@ -2808,23 +3014,28 @@ rb_ary_join(VALUE ary, VALUE sep)
         StringValue(sep);
         len += RSTRING_LEN(sep) * (RARRAY_LEN(ary) - 1);
     }
-    for (i=0; i<RARRAY_LEN(ary); i++) {
+    long len_memo = RARRAY_LEN(ary);
+    for (i=0; i < len_memo; i++) {
         val = RARRAY_AREF(ary, i);
-        tmp = rb_check_string_type(val);
-
-        if (NIL_P(tmp) || tmp != val) {
-            int first;
-            long n = RARRAY_LEN(ary);
-            if (i > n) i = n;
-            result = rb_str_buf_new(len + (n-i)*10);
-            rb_enc_associate(result, rb_usascii_encoding());
-            i = ary_join_0(ary, sep, i, result);
-            first = i == 0;
-            ary_join_1(ary, ary, sep, i, result, &first);
-            return result;
+        if (RB_UNLIKELY(!RB_TYPE_P(val, T_STRING))) {
+            tmp = rb_check_string_type(val);
+            if (NIL_P(tmp) || tmp != val) {
+                int first;
+                long n = RARRAY_LEN(ary);
+                if (i > n) i = n;
+                result = rb_str_buf_new(len + (n-i)*10);
+                rb_enc_associate(result, rb_usascii_encoding());
+                i = ary_join_0(ary, sep, i, result);
+                first = i == 0;
+                ary_join_1(ary, ary, sep, i, result, &first);
+                return result;
+            }
+            len += RSTRING_LEN(tmp);
+            len_memo = RARRAY_LEN(ary);
+        }
+        else {
+            len += RSTRING_LEN(val);
         }
-
-        len += RSTRING_LEN(tmp);
     }
 
     result = rb_str_new(0, len);
@@ -2837,31 +3048,32 @@ rb_ary_join(VALUE ary, VALUE sep)
 
 /*
  *  call-seq:
- *    array.join ->new_string
- *    array.join(separator = $,) -> new_string
+ *    join(separator = $,) -> new_string
  *
- *  Returns the new String formed by joining the array elements after conversion.
- *  For each element +element+:
+ *  Returns the new string formed by joining the converted elements of +self+;
+ *  for each element +element+:
  *
- *  - Uses <tt>element.to_s</tt> if +element+ is not a <tt>kind_of?(Array)</tt>.
- *  - Uses recursive <tt>element.join(separator)</tt> if +element+ is a <tt>kind_of?(Array)</tt>.
+ *  - Converts recursively using <tt>element.join(separator)</tt>
+ *    if +element+ is a <tt>kind_of?(Array)</tt>.
+ *  - Otherwise, converts using <tt>element.to_s</tt>.
  *
- *  With no argument, joins using the output field separator, <tt>$,</tt>:
+ *  With no argument given, joins using the output field separator, <tt>$,</tt>:
  *
  *    a = [:foo, 'bar', 2]
  *    $, # => nil
  *    a.join # => "foobar2"
  *
- *  With \string argument +separator+, joins using that separator:
+ *  With string argument +separator+ given, joins using that separator:
  *
  *    a = [:foo, 'bar', 2]
  *    a.join("\n") # => "foo\nbar\n2"
  *
- *  Joins recursively for nested Arrays:
+ *  Joins recursively for nested arrays:
  *
  *   a = [:foo, [:bar, [:baz, :bat]]]
  *   a.join # => "foobarbazbat"
  *
+ *  Related: see {Methods for Converting}[rdoc-ref:Array@Methods+for+Converting].
  */
 static VALUE
 rb_ary_join_m(int argc, VALUE *argv, VALUE ary)
@@ -2898,14 +3110,16 @@ inspect_ary(VALUE ary, VALUE dummy, int recur)
 
 /*
  *  call-seq:
- *    array.inspect -> new_string
+ *    inspect -> new_string
+ *    to_s -> new_string
  *
- *  Returns the new String formed by calling method <tt>#inspect</tt>
+ *  Returns the new string formed by calling method <tt>#inspect</tt>
  *  on each array element:
  *
  *    a = [:foo, 'bar', 2]
  *    a.inspect # => "[:foo, \"bar\", 2]"
  *
+ *  Related: see {Methods for Converting}[rdoc-ref:Array@Methods+for+Converting].
  */
 
 static VALUE
@@ -2925,21 +3139,17 @@ rb_ary_to_s(VALUE ary)
  *  call-seq:
  *    to_a -> self or new_array
  *
- *  When +self+ is an instance of \Array, returns +self+:
+ *  When +self+ is an instance of \Array, returns +self+.
  *
- *    a = [:foo, 'bar', 2]
- *    a.to_a # => [:foo, "bar", 2]
- *
- *  Otherwise, returns a new \Array containing the elements of +self+:
+ *  Otherwise, returns a new array containing the elements of +self+:
  *
  *    class MyArray < Array; end
- *    a = MyArray.new(['foo', 'bar', 'two'])
- *    a.instance_of?(Array) # => false
- *    a.kind_of?(Array) # => true
- *    a1 = a.to_a
- *    a1 # => ["foo", "bar", "two"]
- *    a1.class # => Array # Not MyArray
+ *    my_a = MyArray.new(['foo', 'bar', 'two'])
+ *    a = my_a.to_a
+ *    a # => ["foo", "bar", "two"]
+ *    a.class # => Array # Not MyArray.
  *
+ *  Related: see {Methods for Converting}[rdoc-ref:Array@Methods+for+Converting].
  */
 
 static VALUE
@@ -2955,27 +3165,27 @@ rb_ary_to_a(VALUE ary)
 
 /*
  *  call-seq:
- *    array.to_h -> new_hash
- *    array.to_h {|item| ... } -> new_hash
+ *    to_h -> new_hash
+ *    to_h {|element| ... } -> new_hash
  *
- *  Returns a new Hash formed from +self+.
+ *  Returns a new hash formed from +self+.
  *
- *  When a block is given, calls the block with each array element;
- *  the block must return a 2-element \Array whose two elements
- *  form a key-value pair in the returned Hash:
+ *  With no block given, each element of +self+ must be a 2-element sub-array;
+ *  forms each sub-array into a key-value pair in the new hash:
  *
- *    a = ['foo', :bar, 1, [2, 3], {baz: 4}]
- *    h = a.to_h {|item| [item, item] }
- *    h # => {"foo"=>"foo", :bar=>:bar, 1=>1, [2, 3]=>[2, 3], {:baz=>4}=>{:baz=>4}}
+ *    a = [['foo', 'zero'], ['bar', 'one'], ['baz', 'two']]
+ *    a.to_h # => {"foo" => "zero", "bar" => "one", "baz" => "two"}
+ *    [].to_h # => {}
  *
- *  When no block is given, +self+ must be an \Array of 2-element sub-arrays,
- *  each sub-array is formed into a key-value pair in the new Hash:
+ *  With a block given, the block must return a 2-element array;
+ *  calls the block with each element of +self+;
+ *  forms each returned array into a key-value pair in the returned hash:
  *
- *    [].to_h # => {}
- *    a = [['foo', 'zero'], ['bar', 'one'], ['baz', 'two']]
- *    h = a.to_h
- *    h # => {"foo"=>"zero", "bar"=>"one", "baz"=>"two"}
+ *    a = ['foo', :bar, 1, [2, 3], {baz: 4}]
+ *    a.to_h {|element| [element, element.class] }
+ *    # => {"foo" => String, bar: Symbol, 1 => Integer, [2, 3] => Array, {baz: 4} => Hash}
  *
+ *  Related: see {Methods for Converting}[rdoc-ref:Array@Methods+for+Converting].
  */
 
 static VALUE
@@ -3004,7 +3214,7 @@ rb_ary_to_h(VALUE ary)
 
 /*
  *  call-seq:
- *    array.to_ary -> self
+ *    to_ary -> self
  *
  *  Returns +self+.
  */
@@ -3043,13 +3253,16 @@ rb_ary_reverse(VALUE ary)
 
 /*
  *  call-seq:
- *    array.reverse! -> self
+ *    reverse! -> self
  *
- *  Reverses +self+ in place:
+ *  Reverses the order of the elements of +self+;
+ *  returns +self+:
  *
- *    a = ['foo', 'bar', 'two']
- *    a.reverse! # => ["two", "bar", "foo"]
+ *    a = [0, 1, 2]
+ *    a.reverse! # => [2, 1, 0]
+ *    a          # => [2, 1, 0]
  *
+ *  Related: see {Methods for Assigning}[rdoc-ref:Array@Methods+for+Assigning].
  */
 
 static VALUE
@@ -3060,14 +3273,13 @@ rb_ary_reverse_bang(VALUE ary)
 
 /*
  *  call-seq:
- *    array.reverse -> new_array
+ *    reverse -> new_array
  *
- *  Returns a new \Array with the elements of +self+ in reverse order:
+ *  Returns a new array containing the elements of +self+ in reverse order:
  *
- *    a = ['foo', 'bar', 'two']
- *    a1 = a.reverse
- *    a1 # => ["two", "bar", "foo"]
+ *    [0, 1, 2].reverse # => [2, 1, 0]
  *
+ *  Related: see {Methods for Combining}[rdoc-ref:Array@Methods+for+Combining].
  */
 
 static VALUE
@@ -3129,48 +3341,34 @@ rb_ary_rotate(VALUE ary, long cnt)
 
 /*
  *  call-seq:
- *    array.rotate! -> self
- *    array.rotate!(count) -> self
+ *    rotate!(count = 1) -> self
  *
  *  Rotates +self+ in place by moving elements from one end to the other; returns +self+.
  *
- *  When no argument given, rotates the first element to the last position:
- *
- *    a = [:foo, 'bar', 2, 'bar']
- *    a.rotate! # => ["bar", 2, "bar", :foo]
- *
- *  When given a non-negative Integer +count+,
+ *  With non-negative numeric +count+,
  *  rotates +count+ elements from the beginning to the end:
  *
- *    a = [:foo, 'bar', 2]
- *    a.rotate!(2)
- *    a # => [2, :foo, "bar"]
+ *    [0, 1, 2, 3].rotate!(2)   # => [2, 3, 0, 1]
+      [0, 1, 2, 3].rotate!(2.1) # => [2, 3, 0, 1]
  *
  *  If +count+ is large, uses <tt>count % array.size</tt> as the count:
  *
- *    a = [:foo, 'bar', 2]
- *    a.rotate!(20)
- *    a # => [2, :foo, "bar"]
+ *    [0, 1, 2, 3].rotate!(21) # => [1, 2, 3, 0]
  *
- *  If +count+ is zero, returns +self+ unmodified:
+ *  If +count+ is zero, rotates no elements:
  *
- *    a = [:foo, 'bar', 2]
- *    a.rotate!(0)
- *    a # => [:foo, "bar", 2]
+ *    [0, 1, 2, 3].rotate!(0) # => [0, 1, 2, 3]
  *
- *  When given a negative Integer +count+, rotates in the opposite direction,
+ *  With a negative numeric +count+, rotates in the opposite direction,
  *  from end to beginning:
  *
- *    a = [:foo, 'bar', 2]
- *    a.rotate!(-2)
- *    a # => ["bar", 2, :foo]
+ *    [0, 1, 2, 3].rotate!(-1) # => [3, 0, 1, 2]
  *
  *  If +count+ is small (far from zero), uses <tt>count % array.size</tt> as the count:
  *
- *    a = [:foo, 'bar', 2]
- *    a.rotate!(-5)
- *    a # => ["bar", 2, :foo]
+ *    [0, 1, 2, 3].rotate!(-21) # => [3, 0, 1, 2]
  *
+ *  Related: see {Methods for Assigning}[rdoc-ref:Array@Methods+for+Assigning].
  */
 
 static VALUE
@@ -3183,51 +3381,35 @@ rb_ary_rotate_bang(int argc, VALUE *argv, VALUE ary)
 
 /*
  *  call-seq:
- *    array.rotate -> new_array
- *    array.rotate(count) -> new_array
+ *    rotate(count = 1) -> new_array
  *
- *  Returns a new \Array formed from +self+ with elements
+ *  Returns a new array formed from +self+ with elements
  *  rotated from one end to the other.
  *
- *  When no argument given, returns a new \Array that is like +self+,
- *  except that the first element has been rotated to the last position:
+ *  With non-negative numeric +count+,
+ *  rotates elements from the beginning to the end:
  *
- *    a = [:foo, 'bar', 2, 'bar']
- *    a1 = a.rotate
- *    a1 # => ["bar", 2, "bar", :foo]
- *
- *  When given a non-negative Integer +count+,
- *  returns a new \Array with +count+ elements rotated from the beginning to the end:
- *
- *    a = [:foo, 'bar', 2]
- *    a1 = a.rotate(2)
- *    a1 # => [2, :foo, "bar"]
+ *    [0, 1, 2, 3].rotate(2)   # => [2, 3, 0, 1]
+ *    [0, 1, 2, 3].rotate(2.1) # => [2, 3, 0, 1]
  *
  *  If +count+ is large, uses <tt>count % array.size</tt> as the count:
  *
- *    a = [:foo, 'bar', 2]
- *    a1 = a.rotate(20)
- *    a1 # => [2, :foo, "bar"]
+ *    [0, 1, 2, 3].rotate(22) # => [2, 3, 0, 1]
  *
- *  If +count+ is zero, returns a copy of +self+, unmodified:
+ *  With a +count+ of zero, rotates no elements:
  *
- *    a = [:foo, 'bar', 2]
- *    a1 = a.rotate(0)
- *    a1 # => [:foo, "bar", 2]
+ *    [0, 1, 2, 3].rotate(0) # => [0, 1, 2, 3]
  *
- *  When given a negative Integer +count+, rotates in the opposite direction,
- *  from end to beginning:
+ *  With negative numeric +count+, rotates in the opposite direction,
+ *  from the end to the beginning:
  *
- *    a = [:foo, 'bar', 2]
- *    a1 = a.rotate(-2)
- *    a1 # => ["bar", 2, :foo]
+ *    [0, 1, 2, 3].rotate(-1) # => [3, 0, 1, 2]
  *
  *  If +count+ is small (far from zero), uses <tt>count % array.size</tt> as the count:
  *
- *    a = [:foo, 'bar', 2]
- *    a1 = a.rotate(-5)
- *    a1 # => ["bar", 2, :foo]
+ *    [0, 1, 2, 3].rotate(-21) # => [3, 0, 1, 2]
  *
+ *  Related: see {Methods for Fetching}[rdoc-ref:Array@Methods+for+Fetching].
  */
 
 static VALUE
@@ -3320,50 +3502,19 @@ sort_2(const void *ap, const void *bp, void *dummy)
 
 /*
  *  call-seq:
- *    array.sort! -> self
- *    array.sort! {|a, b| ... } -> self
+ *    sort! -> self
+ *    sort! {|a, b| ... } -> self
  *
- *  Returns +self+ with its elements sorted in place.
- *
- *  With no block, compares elements using operator <tt><=></tt>
- *  (see Comparable):
- *
- *    a = 'abcde'.split('').shuffle
- *    a # => ["e", "b", "d", "a", "c"]
- *    a.sort!
- *    a # => ["a", "b", "c", "d", "e"]
- *
- *  With a block, calls the block with each element pair;
- *  for each element pair +a+ and +b+, the block should return an integer:
- *
- *  - Negative when +b+ is to follow +a+.
- *  - Zero when +a+ and +b+ are equivalent.
- *  - Positive when +a+ is to follow +b+.
- *
- *  Example:
- *
- *    a = 'abcde'.split('').shuffle
- *    a # => ["e", "b", "d", "a", "c"]
- *    a.sort! {|a, b| a <=> b }
- *    a # => ["a", "b", "c", "d", "e"]
- *    a.sort! {|a, b| b <=> a }
- *    a # => ["e", "d", "c", "b", "a"]
- *
- *  When the block returns zero, the order for +a+ and +b+ is indeterminate,
- *  and may be unstable:
- *
- *    a = 'abcde'.split('').shuffle
- *    a # => ["e", "b", "d", "a", "c"]
- *    a.sort! {|a, b| 0 }
- *    a # => ["d", "e", "c", "a", "b"]
+ *  Like Array#sort, but returns +self+ with its elements sorted in place.
  *
+ *  Related: see {Methods for Assigning}[rdoc-ref:Array@Methods+for+Assigning].
  */
 
 VALUE
 rb_ary_sort_bang(VALUE ary)
 {
     rb_ary_modify(ary);
-    assert(!ARY_SHARED_P(ary));
+    RUBY_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;
@@ -3381,6 +3532,9 @@ rb_ary_sort_bang(VALUE ary)
                 rb_ary_unshare(ary);
                 FL_SET_EMBED(ary);
             }
+            if (ARY_EMBED_LEN(tmp) > ARY_CAPA(ary)) {
+                ary_resize_capa(ary, ARY_EMBED_LEN(tmp));
+            }
             ary_memcpy(ary, 0, ARY_EMBED_LEN(tmp), ARY_EMBED_PTR(tmp));
             ARY_SET_LEN(ary, ARY_EMBED_LEN(tmp));
         }
@@ -3390,7 +3544,7 @@ rb_ary_sort_bang(VALUE ary)
                 ARY_SET_CAPA(ary, RARRAY_LEN(tmp));
             }
             else {
-                assert(!ARY_SHARED_P(tmp));
+                RUBY_ASSERT(!ARY_SHARED_P(tmp));
                 if (ARY_EMBED_P(ary)) {
                     FL_UNSET_EMBED(ary);
                 }
@@ -3406,10 +3560,9 @@ rb_ary_sort_bang(VALUE ary)
                 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);
+            OBJ_FREEZE(tmp);
         }
         /* tmp will be GC'ed. */
         RBASIC_SET_CLASS_RAW(tmp, rb_cArray); /* rb_cArray must be marked */
@@ -3420,21 +3573,18 @@ rb_ary_sort_bang(VALUE ary)
 
 /*
  *  call-seq:
- *    array.sort -> new_array
- *    array.sort {|a, b| ... } -> new_array
+ *    sort -> new_array
+ *    sort {|a, b| ... } -> new_array
  *
- *  Returns a new \Array whose elements are those from +self+, sorted.
+ *  Returns a new array containing the elements of +self+, sorted.
  *
- *  With no block, compares elements using operator <tt><=></tt>
- *  (see Comparable):
+ *  With no block given, compares elements using operator <tt>#<=></tt>
+ *  (see Object#<=>):
  *
- *    a = 'abcde'.split('').shuffle
- *    a # => ["e", "b", "d", "a", "c"]
- *    a1 = a.sort
- *    a1 # => ["a", "b", "c", "d", "e"]
+ *    [0, 2, 3, 1].sort # => [0, 1, 2, 3]
  *
- *  With a block, calls the block with each element pair;
- *  for each element pair +a+ and +b+, the block should return an integer:
+ *  With a block given, calls the block with each combination of pairs of elements from +self+;
+ *  for each pair +a+ and +b+, the block should return a numeric:
  *
  *  - Negative when +b+ is to follow +a+.
  *  - Zero when +a+ and +b+ are equivalent.
@@ -3442,22 +3592,17 @@ rb_ary_sort_bang(VALUE ary)
  *
  *  Example:
  *
- *    a = 'abcde'.split('').shuffle
- *    a # => ["e", "b", "d", "a", "c"]
- *    a1 = a.sort {|a, b| a <=> b }
- *    a1 # => ["a", "b", "c", "d", "e"]
- *    a2 = a.sort {|a, b| b <=> a }
- *    a2 # => ["e", "d", "c", "b", "a"]
+ *    a = [3, 2, 0, 1]
+ *    a.sort {|a, b| a <=> b } # => [0, 1, 2, 3]
+ *    a.sort {|a, b| b <=> a } # => [3, 2, 1, 0]
  *
  *  When the block returns zero, the order for +a+ and +b+ is indeterminate,
- *  and may be unstable:
+ *  and may be unstable.
  *
- *    a = 'abcde'.split('').shuffle
- *    a # => ["e", "b", "d", "a", "c"]
- *    a1 = a.sort {|a, b| 0 }
- *    a1 # =>  ["c", "e", "b", "d", "a"]
+ *  See an example in Numeric#nonzero? for the idiom to sort more
+ *  complex structure.
  *
- *  Related: Enumerable#sort_by.
+ *  Related: see {Methods for Fetching}[rdoc-ref:Array@Methods+for+Fetching].
  */
 
 VALUE
@@ -3472,12 +3617,15 @@ static VALUE rb_ary_bsearch_index(VALUE ary);
 
 /*
  *  call-seq:
- *    array.bsearch {|element| ... } -> object
- *    array.bsearch -> new_enumerator
+ *    bsearch {|element| ... } -> found_element or nil
+ *    bsearch -> new_enumerator
  *
- *  Returns an element from +self+ selected by a binary search.
+ *  Returns the element from +self+ found by a binary search,
+ *  or +nil+ if the search found no suitable element.
  *
- *  See {Binary Searching}[rdoc-ref:bsearch.rdoc].
+ *  See {Binary Searching}[rdoc-ref:language/bsearch.rdoc].
+ *
+ *  Related: see {Methods for Fetching}[rdoc-ref:Array@Methods+for+Fetching].
  */
 
 static VALUE
@@ -3493,11 +3641,15 @@ rb_ary_bsearch(VALUE ary)
 
 /*
  *  call-seq:
- *    array.bsearch_index {|element| ... } -> integer or nil
- *    array.bsearch_index -> new_enumerator
+ *    bsearch_index {|element| ... } -> integer or nil
+ *    bsearch_index -> new_enumerator
+ *
+ *  Returns the integer index of the element from +self+ found by a binary search,
+ *  or +nil+ if the search found no suitable element.
+ *
+ *  See {Binary Searching}[rdoc-ref:language/bsearch.rdoc].
  *
- *  Searches +self+ as described at method #bsearch,
- *  but returns the _index_ of the found element instead of the element itself.
+ *  Related: see {Methods for Fetching}[rdoc-ref:Array@Methods+for+Fetching].
  */
 
 static VALUE
@@ -3556,28 +3708,24 @@ sort_by_i(RB_BLOCK_CALL_FUNC_ARGLIST(i, dummy))
 
 /*
  *  call-seq:
- *    array.sort_by! {|element| ... } -> self
- *    array.sort_by! -> new_enumerator
+ *    sort_by! {|element| ... } -> self
+ *    sort_by! -> new_enumerator
  *
- *  Sorts the elements of +self+ in place,
- *  using an ordering determined by the block; returns self.
+ *  With a block given, sorts the elements of +self+ in place;
+ *  returns self.
  *
  *  Calls the block with each successive element;
- *  sorts elements based on the values returned from the block.
- *
- *  For duplicates returned by the block, the ordering is indeterminate, and may be unstable.
- *
- *  This example sorts strings based on their sizes:
+ *  sorts elements based on the values returned from the block:
  *
  *    a = ['aaaa', 'bbb', 'cc', 'd']
  *    a.sort_by! {|element| element.size }
  *    a # => ["d", "cc", "bbb", "aaaa"]
  *
- *  Returns a new Enumerator if no block given:
+ *  For duplicate values returned by the block, the ordering is indeterminate, and may be unstable.
  *
- *    a = ['aaaa', 'bbb', 'cc', 'd']
- *    a.sort_by! # => #<Enumerator: ["aaaa", "bbb", "cc", "d"]:sort_by!>
+ *  With no block given, returns a new Enumerator.
  *
+ *  Related: see {Methods for Assigning}[rdoc-ref:Array@Methods+for+Assigning].
  */
 
 static VALUE
@@ -3587,29 +3735,32 @@ rb_ary_sort_by_bang(VALUE ary)
 
     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);
+    if (RARRAY_LEN(ary) > 1) {
+        sorted = rb_block_call(ary, rb_intern("sort_by"), 0, 0, sort_by_i, 0);
+        rb_ary_replace(ary, sorted);
+    }
     return ary;
 }
 
 
 /*
  *  call-seq:
- *    array.map {|element| ... } -> new_array
- *    array.map -> new_enumerator
+ *    collect {|element| ... } -> new_array
+ *    collect -> new_enumerator
+ *    map {|element| ... } -> new_array
+ *    map -> new_enumerator
  *
- *  Calls the block, if given, with each element of +self+;
- *  returns a new \Array whose elements are the return values from the block:
+ *  With a block given, calls the block with each element of +self+;
+ *  returns a new array whose elements are the return values from the block:
  *
  *    a = [:foo, 'bar', 2]
  *    a1 = a.map {|element| element.class }
  *    a1 # => [Symbol, String, Integer]
  *
- *  Returns a new Enumerator if no block given:
- *    a = [:foo, 'bar', 2]
- *    a1 = a.map
- *    a1 # => #<Enumerator: [:foo, "bar", 2]:map>
+ *  With no block given, returns a new Enumerator.
  *
+ *  Related: #collect!;
+ *  see also {Methods for Converting}[rdoc-ref:Array@Methods+for+Converting].
  */
 
 static VALUE
@@ -3629,21 +3780,22 @@ rb_ary_collect(VALUE ary)
 
 /*
  *  call-seq:
- *    array.map! {|element| ... } -> self
- *    array.map! -> new_enumerator
+ *    collect! {|element| ... } -> self
+ *    collect! -> new_enumerator
+ *    map! {|element| ... } -> self
+ *    map! -> new_enumerator
  *
- *  Calls the block, if given, with each element;
- *  replaces the element with the block's return value:
+ *  With a block given, calls the block with each element of +self+
+ *  and replaces the element with the block's return value;
+ *  returns +self+:
  *
  *    a = [:foo, 'bar', 2]
  *    a.map! { |element| element.class } # => [Symbol, String, Integer]
  *
- *  Returns a new Enumerator if no block given:
- *
- *    a = [:foo, 'bar', 2]
- *    a1 = a.map!
- *    a1 # => #<Enumerator: [:foo, "bar", 2]:map!>
+ *  With no block given, returns a new Enumerator.
  *
+ *  Related: #collect;
+ *  see also {Methods for Converting}[rdoc-ref:Array@Methods+for+Converting].
  */
 
 static VALUE
@@ -3715,45 +3867,108 @@ append_values_at_single(VALUE result, VALUE ary, long olen, VALUE idx)
 
 /*
  *  call-seq:
- *    array.values_at(*indexes) -> new_array
+ *    values_at(*specifiers) -> new_array
  *
- *  Returns a new \Array whose elements are the elements
- *  of +self+ at the given Integer or Range +indexes+.
+ *  Returns elements from +self+ in a new array; does not modify +self+.
  *
- *  For each positive +index+, returns the element at offset +index+:
+ *  The objects included in the returned array are the elements of +self+
+ *  selected by the given +specifiers+,
+ *  each of which must be a numeric index or a Range.
  *
- *    a = [:foo, 'bar', 2]
- *    a.values_at(0, 2) # => [:foo, 2]
- *    a.values_at(0..1) # => [:foo, "bar"]
+ *  In brief:
  *
- *  The given +indexes+ may be in any order, and may repeat:
+ *    a = ['a', 'b', 'c', 'd']
  *
- *    a = [:foo, 'bar', 2]
- *    a.values_at(2, 0, 1, 0, 2) # => [2, :foo, "bar", :foo, 2]
- *    a.values_at(1, 0..2) # => ["bar", :foo, "bar", 2]
+ *    # Index specifiers.
+ *    a.values_at(2, 0, 2, 0)     # => ["c", "a", "c", "a"] # May repeat.
+ *    a.values_at(-4, -3, -2, -1) # => ["a", "b", "c", "d"] # Counts backwards if negative.
+ *    a.values_at(-50, 50)        # => [nil, nil]           # Outside of self.
  *
- *  Assigns +nil+ for an +index+ that is too large:
+ *    # Range specifiers.
+ *    a.values_at(1..3)       # => ["b", "c", "d"] # From range.begin to range.end.
+ *    a.values_at(1...3)      # => ["b", "c"]      # End excluded.
+ *    a.values_at(3..1)       # => []              # No such elements.
  *
- *    a = [:foo, 'bar', 2]
- *    a.values_at(0, 3, 1, 3) # => [:foo, nil, "bar", nil]
+ *    a.values_at(-3..3)  # => ["b", "c", "d"]     # Negative range.begin counts backwards.
+ *    a.values_at(-50..3)                          # Raises RangeError.
  *
- *  Returns a new empty \Array if no arguments given.
+ *    a.values_at(1..-2)  # => ["b", "c"]          # Negative range.end counts backwards.
+ *    a.values_at(1..-50) # => []                  # No such elements.
  *
- *  For each negative +index+, counts backward from the end of the array:
+ *    # Mixture of specifiers.
+ *    a.values_at(2..3, 3, 0..1, 0) # => ["c", "d", "d", "a", "b", "a"]
  *
- *    a = [:foo, 'bar', 2]
- *    a.values_at(-1, -3) # => [2, :foo]
+ *  With no +specifiers+ given, returns a new empty array:
  *
- *  Assigns +nil+ for an +index+ that is too small:
+ *    a = ['a', 'b', 'c', 'd']
+ *    a.values_at # => []
  *
- *    a = [:foo, 'bar', 2]
- *    a.values_at(0, -5, 1, -6, 2) # => [:foo, nil, "bar", nil, 2]
+ *  For each numeric specifier +index+, includes an element:
  *
- *  The given +indexes+ may have a mixture of signs:
+ *  - For each non-negative numeric specifier +index+ that is in-range (less than <tt>self.size</tt>),
+ *    includes the element at offset +index+:
  *
- *    a = [:foo, 'bar', 2]
- *    a.values_at(0, -2, 1, -1) # => [:foo, "bar", "bar", 2]
+ *      a.values_at(0, 2)     # => ["a", "c"]
+ *      a.values_at(0.1, 2.9) # => ["a", "c"]
+ *
+ *  - For each negative numeric +index+ that is in-range (greater than or equal to <tt>- self.size</tt>),
+ *    counts backwards from the end of +self+:
+ *
+ *      a.values_at(-1, -4) # => ["d", "a"]
+ *
+ *  The given indexes may be in any order, and may repeat:
+ *
+ *    a.values_at(2, 0, 1, 0, 2) # => ["c", "a", "b", "a", "c"]
+ *
+ *  For each +index+ that is out-of-range, includes +nil+:
+ *
+ *    a.values_at(4, -5) # => [nil, nil]
+ *
+ *  For each Range specifier +range+, includes elements
+ *  according to <tt>range.begin</tt> and <tt>range.end</tt>:
+ *
+ *  - If both <tt>range.begin</tt> and <tt>range.end</tt>
+ *    are non-negative and in-range (less than <tt>self.size</tt>),
+ *    includes elements from index <tt>range.begin</tt>
+ *    through <tt>range.end - 1</tt> (if <tt>range.exclude_end?</tt>),
+ *    or through <tt>range.end</tt> (otherwise):
+ *
+ *      a.values_at(1..2)  # => ["b", "c"]
+ *      a.values_at(1...2) # => ["b"]
+ *
+ *  - If <tt>range.begin</tt> is negative and in-range (greater than or equal to <tt>- self.size</tt>),
+ *    counts backwards from the end of +self+:
+ *
+ *      a.values_at(-2..3) # => ["c", "d"]
+ *
+ *  - If <tt>range.begin</tt> is negative and out-of-range, raises an exception:
+ *
+ *      a.values_at(-5..3) # Raises RangeError.
+ *
+ *  - If <tt>range.end</tt> is positive and out-of-range,
+ *    extends the returned array with +nil+ elements:
+ *
+ *      a.values_at(1..5) # => ["b", "c", "d", nil, nil]
+ *
+ *  - If <tt>range.end</tt> is negative and in-range,
+ *    counts backwards from the end of +self+:
+ *
+ *      a.values_at(1..-2) # => ["b", "c"]
+ *
+ *  - If <tt>range.end</tt> is negative and out-of-range,
+ *    returns an empty array:
  *
+ *      a.values_at(1..-5) # => []
+ *
+ *  The given ranges may be in any order and may repeat:
+ *
+ *    a.values_at(2..3, 0..1, 2..3) # => ["c", "d", "a", "b", "c", "d"]
+ *
+ *  The given specifiers may be any mixture of indexes and ranges:
+ *
+ *    a.values_at(3, 1..2, 0, 2..3) # => ["d", "b", "c", "a", "c", "d"]
+ *
+ *  Related: see {Methods for Fetching}[rdoc-ref:Array@Methods+for+Fetching].
  */
 
 static VALUE
@@ -3771,22 +3986,22 @@ rb_ary_values_at(int argc, VALUE *argv, VALUE ary)
 
 /*
  *  call-seq:
- *    array.select {|element| ... } -> new_array
- *    array.select -> new_enumerator
+ *    select {|element| ... } -> new_array
+ *    select -> new_enumerator
+ *    filter {|element| ... } -> new_array
+ *    filter -> new_enumerator
  *
- *  Calls the block, if given, with each element of +self+;
- *  returns a new \Array containing those elements of +self+
+ *  With a block given, calls the block with each element of +self+;
+ *  returns a new array containing those elements of +self+
  *  for which the block returns a truthy value:
  *
  *    a = [:foo, 'bar', 2, :bam]
- *    a1 = a.select {|element| element.to_s.start_with?('b') }
- *    a1 # => ["bar", :bam]
+ *    a.select {|element| element.to_s.start_with?('b') }
+ *    # => ["bar", :bam]
  *
- *  Returns a new Enumerator if no block given:
- *
- *    a = [:foo, 'bar', 2, :bam]
- *    a.select # => #<Enumerator: [:foo, "bar", 2, :bam]:select>
+ *  With no block given, returns a new Enumerator.
  *
+ *  Related: see {Methods for Fetching}[rdoc-ref:Array@Methods+for+Fetching].
  */
 
 static VALUE
@@ -3852,10 +4067,12 @@ select_bang_ensure(VALUE a)
 
 /*
  *  call-seq:
- *    array.select! {|element| ... } -> self or nil
- *    array.select! -> new_enumerator
+ *    select! {|element| ... } -> self or nil
+ *    select! -> new_enumerator
+ *    filter! {|element| ... } -> self or nil
+ *    filter! -> new_enumerator
  *
- *  Calls the block, if given  with each element of +self+;
+ *  With a block given, calls the block with each element of +self+;
  *  removes from +self+ those elements for which the block returns +false+ or +nil+.
  *
  *  Returns +self+ if any elements were removed:
@@ -3865,11 +4082,9 @@ select_bang_ensure(VALUE a)
  *
  *  Returns +nil+ if no elements were removed.
  *
- *  Returns a new Enumerator if no block given:
- *
- *    a = [:foo, 'bar', 2, :bam]
- *    a.select! # => #<Enumerator: [:foo, "bar", 2, :bam]:select!>
+ *  With no block given, returns a new Enumerator.
  *
+ *  Related: see {Methods for Deleting}[rdoc-ref:Array@Methods+for+Deleting].
  */
 
 static VALUE
@@ -3887,20 +4102,18 @@ rb_ary_select_bang(VALUE ary)
 
 /*
  *  call-seq:
- *    array.keep_if {|element| ... } -> self
- *    array.keep_if -> new_enumeration
+ *    keep_if {|element| ... } -> self
+ *    keep_if -> new_enumerator
  *
- *  Retains those elements for which the block returns a truthy value;
- *  deletes all other elements; returns +self+:
+ *  With a block given, calls the block with each element of +self+;
+ *  removes the element from +self+ if the block does not return a truthy value:
  *
  *    a = [:foo, 'bar', 2, :bam]
  *    a.keep_if {|element| element.to_s.start_with?('b') } # => ["bar", :bam]
  *
- *  Returns a new Enumerator if no block given:
- *
- *    a = [:foo, 'bar', 2, :bam]
- *    a.keep_if # => #<Enumerator: [:foo, "bar", 2, :bam]:keep_if>
+ *  With no block given, returns a new Enumerator.
  *
+ *  Related: see {Methods for Deleting}[rdoc-ref:Array@Methods+for+Deleting].
  */
 
 static VALUE
@@ -3926,38 +4139,39 @@ ary_resize_smaller(VALUE ary, long len)
 
 /*
  *  call-seq:
- *    array.delete(obj) -> deleted_object
- *    array.delete(obj) {|nosuch| ... } -> deleted_object or block_return
+ *    delete(object) -> last_removed_object
+ *    delete(object) {|element| ... } -> last_removed_object or block_return
  *
  *  Removes zero or more elements from +self+.
  *
- *  When no block is given,
- *  removes from +self+ each element +ele+ such that <tt>ele == obj</tt>;
- *  returns the last deleted element:
+ *  With no block given,
+ *  removes from +self+ each element +ele+ such that <tt>ele == object</tt>;
+ *  returns the last removed element:
  *
- *    s1 = 'bar'; s2 = 'bar'
- *    a = [:foo, s1, 2, s2]
- *    a.delete('bar') # => "bar"
- *    a # => [:foo, 2]
+ *    a = [0, 1, 2, 2.0]
+ *    a.delete(2) # => 2.0
+ *    a           # => [0, 1]
  *
- *  Returns +nil+ if no elements removed.
+ *  Returns +nil+ if no elements removed:
  *
- *  When a block is given,
- *  removes from +self+ each element +ele+ such that <tt>ele == obj</tt>.
+ *    a.delete(2) # => nil
+ *
+ *  With a block given,
+ *  removes from +self+ each element +ele+ such that <tt>ele == object</tt>.
  *
  *  If any such elements are found, ignores the block
- *  and returns the last deleted element:
+ *  and returns the last removed element:
  *
- *    s1 = 'bar'; s2 = 'bar'
- *    a = [:foo, s1, 2, s2]
- *    deleted_obj = a.delete('bar') {|obj| fail 'Cannot happen' }
- *    a # => [:foo, 2]
+ *    a = [0, 1, 2, 2.0]
+ *    a.delete(2) {|element| fail 'Cannot happen' } # => 2.0
+ *    a                                             # => [0, 1]
  *
- *  If no such elements are found, returns the block's return value:
+ *  If no such element is found, returns the block's return value:
  *
- *    a = [:foo, 'bar', 2]
- *    a.delete(:nosuch) {|obj| "#{obj} not found" } # => "nosuch not found"
+ *    a.delete(2) {|element| "Element #{element} not found." }
+ *    # => "Element 2 not found."
  *
+ *  Related: see {Methods for Deleting}[rdoc-ref:Array@Methods+for+Deleting].
  */
 
 VALUE
@@ -4038,9 +4252,10 @@ rb_ary_delete_at(VALUE ary, long pos)
 
 /*
  *  call-seq:
- *    array.delete_at(index) -> deleted_object or nil
+ *    delete_at(index) -> removed_object or nil
  *
- *  Deletes an element from +self+, per the given Integer +index+.
+ *  Removes the element of +self+ at the given +index+, which must be an
+ *  {integer-convertible object}[rdoc-ref:implicit_conversion.rdoc@Integer-Convertible+Objects].
  *
  *  When +index+ is non-negative, deletes the element at offset +index+:
  *
@@ -4048,15 +4263,19 @@ rb_ary_delete_at(VALUE ary, long pos)
  *    a.delete_at(1) # => "bar"
  *    a # => [:foo, 2]
  *
- *  If index is too large, returns +nil+.
- *
  *  When +index+ is negative, counts backward from the end of the array:
  *
  *    a = [:foo, 'bar', 2]
  *    a.delete_at(-2) # => "bar"
  *    a # => [:foo, 2]
  *
- *  If +index+ is too small (far from zero), returns nil.
+ *  When +index+ is out of range, returns +nil+.
+ *
+ *    a = [:foo, 'bar', 2]
+ *    a.delete_at(3)  # => nil
+ *    a.delete_at(-4) # => nil
+ *
+ *  Related: see {Methods for Deleting}[rdoc-ref:Array@Methods+for+Deleting].
  */
 
 static VALUE
@@ -4097,71 +4316,94 @@ ary_slice_bang_by_rb_ary_splice(VALUE ary, long pos, long len)
 
 /*
  *  call-seq:
- *    array.slice!(n) -> object or nil
- *    array.slice!(start, length) -> new_array or nil
- *    array.slice!(range) -> new_array or nil
+ *    slice!(index) -> object or nil
+ *    slice!(start, length) -> new_array or nil
+ *    slice!(range) -> new_array or nil
  *
  *  Removes and returns elements from +self+.
  *
- *  When the only argument is an Integer +n+,
- *  removes and returns the _nth_ element in +self+:
+ *  With numeric argument +index+ given,
+ *  removes and returns the element at offset +index+:
  *
- *    a = [:foo, 'bar', 2]
- *    a.slice!(1) # => "bar"
- *    a # => [:foo, 2]
+ *    a = ['a', 'b', 'c', 'd']
+ *    a.slice!(2)   # => "c"
+ *    a             # => ["a", "b", "d"]
+ *    a.slice!(2.1) # => "d"
+ *    a             # => ["a", "b"]
  *
- *  If +n+ is negative, counts backwards from the end of +self+:
+ *  If +index+ is negative, counts backwards from the end of +self+:
  *
- *    a = [:foo, 'bar', 2]
- *    a.slice!(-1) # => 2
- *    a # => [:foo, "bar"]
+ *    a = ['a', 'b', 'c', 'd']
+ *    a.slice!(-2) # => "c"
+ *    a            # => ["a", "b", "d"]
  *
- *  If +n+ is out of range, returns +nil+.
+ *  If +index+ is out of range, returns +nil+.
  *
- *  When the only arguments are Integers +start+ and +length+,
- *  removes +length+ elements from +self+ beginning at offset  +start+;
- *  returns the deleted objects in a new \Array:
+ *  With numeric arguments +start+ and +length+ given,
+ *  removes +length+ elements from +self+ beginning at zero-based offset +start+;
+ *  returns the removed objects in a new array:
  *
- *    a = [:foo, 'bar', 2]
- *    a.slice!(0, 2) # => [:foo, "bar"]
- *    a # => [2]
+ *    a = ['a', 'b', 'c', 'd']
+ *    a.slice!(1, 2)     # => ["b", "c"]
+ *    a                  # => ["a", "d"]
+ *    a.slice!(0.1, 1.1) # => ["a"]
+ *    a                  # => ["d"]
+ *
+ *  If +start+ is negative, counts backwards from the end of +self+:
+ *
+ *    a = ['a', 'b', 'c', 'd']
+ *    a.slice!(-2, 1) # => ["c"]
+ *    a               # => ["a", "b", "d"]
+ *
+ *  If +start+ is out-of-range, returns +nil+:
+ *
+ *    a = ['a', 'b', 'c', 'd']
+ *    a.slice!(5, 1)  # => nil
+ *    a.slice!(-5, 1) # => nil
  *
  *  If <tt>start + length</tt> exceeds the array size,
  *  removes and returns all elements from offset +start+ to the end:
  *
- *    a = [:foo, 'bar', 2]
- *    a.slice!(1, 50) # => ["bar", 2]
- *    a # => [:foo]
+ *    a = ['a', 'b', 'c', 'd']
+ *    a.slice!(2, 50) # => ["c", "d"]
+ *    a               # => ["a", "b"]
  *
  *  If <tt>start == a.size</tt> and +length+ is non-negative,
- *  returns a new empty \Array.
+ *  returns a new empty array.
  *
  *  If +length+ is negative, returns +nil+.
  *
- *  When the only argument is a Range object +range+,
- *  treats <tt>range.min</tt> as +start+ above and <tt>range.size</tt> as +length+ above:
+ *  With Range argument +range+ given,
+ *  treats <tt>range.min</tt> as +start+ (as above)
+ *  and <tt>range.size</tt> as +length+ (as above):
  *
- *    a = [:foo, 'bar', 2]
- *    a.slice!(1..2) # => ["bar", 2]
- *    a # => [:foo]
+ *    a = ['a', 'b', 'c', 'd']
+ *    a.slice!(1..2) # => ["b", "c"]
+ *    a              # => ["a", "d"]
  *
- *  If <tt>range.start == a.size</tt>, returns a new empty \Array.
+ *  If <tt>range.start == a.size</tt>, returns a new empty array:
  *
- *  If <tt>range.start</tt> is larger than the array size, returns +nil+.
+ *    a = ['a', 'b', 'c', 'd']
+ *    a.slice!(4..5) # => []
  *
- *  If <tt>range.end</tt> is negative, counts backwards from the end of the array:
+ *  If <tt>range.start</tt> is larger than the array size, returns +nil+:
  *
- *    a = [:foo, 'bar', 2]
- *    a.slice!(0..-2) # => [:foo, "bar"]
- *    a # => [2]
+ *    a = ['a', 'b', 'c', 'd']
+      a.slice!(5..6) # => nil
  *
  *  If <tt>range.start</tt> is negative,
- *  calculates the start index backwards from the end of the array:
+ *  calculates the start index by counting backwards from the end of +self+:
  *
- *    a = [:foo, 'bar', 2]
- *    a.slice!(-2..2) # => ["bar", 2]
- *    a # => [:foo]
+ *    a = ['a', 'b', 'c', 'd']
+ *    a.slice!(-2..2) # => ["c"]
  *
+ *  If <tt>range.end</tt> is negative,
+ *  calculates the end index by counting backwards from the end of +self+:
+ *
+ *    a = ['a', 'b', 'c', 'd']
+ *    a.slice!(0..-2) # => ["a", "b", "c"]
+ *
+ *  Related: see {Methods for Deleting}[rdoc-ref:Array@Methods+for+Deleting].
  */
 
 static VALUE
@@ -4242,10 +4484,11 @@ ary_reject_bang(VALUE ary)
 
 /*
  *  call-seq:
- *    array.reject! {|element| ... } -> self or nil
- *    array.reject! -> new_enumerator
+ *    reject! {|element| ... } -> self or nil
+ *    reject! -> new_enumerator
  *
- *  Removes each element for which the block returns a truthy value.
+ *  With a block given, calls the block with each element of +self+;
+ *  removes each element for which the block returns a truthy value.
  *
  *  Returns +self+ if any elements removed:
  *
@@ -4254,11 +4497,9 @@ ary_reject_bang(VALUE ary)
  *
  *  Returns +nil+ if no elements removed.
  *
- *  Returns a new Enumerator if no block given:
- *
- *    a = [:foo, 'bar', 2]
- *    a.reject! # => #<Enumerator: [:foo, "bar", 2]:reject!>
+ *  With no block given, returns a new Enumerator.
  *
+ *  Related: see {Methods for Deleting}[rdoc-ref:Array@Methods+for+Deleting].
  */
 
 static VALUE
@@ -4271,21 +4512,19 @@ rb_ary_reject_bang(VALUE ary)
 
 /*
  *  call-seq:
- *    array.reject {|element| ... } -> new_array
- *    array.reject -> new_enumerator
+ *    reject {|element| ... } -> new_array
+ *    reject -> new_enumerator
  *
- *  Returns a new \Array whose elements are all those from +self+
+ *  With a block given, returns a new array whose elements are all those from +self+
  *  for which the block returns +false+ or +nil+:
  *
  *    a = [:foo, 'bar', 2, 'bat']
  *    a1 = a.reject {|element| element.to_s.start_with?('b') }
  *    a1 # => [:foo, 2]
  *
- *  Returns a new Enumerator if no block given:
- *
- *     a = [:foo, 'bar', 2]
- *     a.reject # => #<Enumerator: [:foo, "bar", 2]:reject>
+ *  With no block given, returns a new Enumerator.
  *
+ *  Related: {Methods for Fetching}[rdoc-ref:Array@Methods+for+Fetching].
  */
 
 static VALUE
@@ -4301,20 +4540,19 @@ rb_ary_reject(VALUE ary)
 
 /*
  *  call-seq:
- *    array.delete_if {|element| ... } -> self
- *    array.delete_if -> Enumerator
+ *    delete_if {|element| ... } -> self
+ *    delete_if -> new_numerator
  *
- *  Removes each element in +self+ for which the block returns a truthy value;
+ *  With a block given, calls the block with each element of +self+;
+ *  removes the element if the block returns a truthy value;
  *  returns +self+:
  *
  *    a = [:foo, 'bar', 2, 'bat']
  *    a.delete_if {|element| element.to_s.start_with?('b') } # => [:foo, 2]
  *
- *  Returns a new Enumerator if no block given:
- *
- *    a = [:foo, 'bar', 2]
- *    a.delete_if # => #<Enumerator: [:foo, "bar", 2]:delete_if>
+ *  With no block given, returns a new Enumerator.
  *
+ *  Related: see {Methods for Deleting}[rdoc-ref:Array@Methods+for+Deleting].
  */
 
 static VALUE
@@ -4355,58 +4593,95 @@ take_items(VALUE obj, long n)
 
 /*
  *  call-seq:
- *    array.zip(*other_arrays) -> new_array
- *    array.zip(*other_arrays) {|other_array| ... } -> nil
+ *    zip(*other_arrays) -> new_array
+ *    zip(*other_arrays) {|sub_array| ... } -> nil
+ *
+ *  With no block given, combines +self+ with the collection of +other_arrays+;
+ *  returns a new array of sub-arrays:
+ *
+ *    [0, 1].zip(['zero', 'one'], [:zero, :one])
+ *    # => [[0, "zero", :zero], [1, "one", :one]]
  *
- *  When no block given, returns a new \Array +new_array+ of size <tt>self.size</tt>
- *  whose elements are Arrays.
+ *  Returned:
  *
- *  Each nested array <tt>new_array[n]</tt> is of size <tt>other_arrays.size+1</tt>,
- *  and contains:
+ *  - The outer array is of size <tt>self.size</tt>.
+ *  - Each sub-array is of size <tt>other_arrays.size + 1</tt>.
+ *  - The _nth_ sub-array contains (in order):
  *
- *  - The _nth_ element of +self+.
- *  - The _nth_ element of each of the +other_arrays+.
+ *    - The _nth_ element of +self+.
+ *    - The _nth_ element of each of the other arrays, as available.
+ *
+ *  Example:
+ *
+ *    a = [0, 1]
+ *    zipped = a.zip(['zero', 'one'], [:zero, :one])
+ *    # => [[0, "zero", :zero], [1, "one", :one]]
+ *    zipped.size       # => 2 # Same size as a.
+ *    zipped.first.size # => 3 # Size of other arrays plus 1.
  *
- *  If all +other_arrays+ and +self+ are the same size:
+ *  When the other arrays are all the same size as +self+,
+ *  the returned sub-arrays are a rearrangement containing exactly elements of all the arrays
+ *  (including +self+), with no omissions or additions:
  *
  *    a = [:a0, :a1, :a2, :a3]
  *    b = [:b0, :b1, :b2, :b3]
  *    c = [:c0, :c1, :c2, :c3]
  *    d = a.zip(b, c)
- *    d # => [[:a0, :b0, :c0], [:a1, :b1, :c1], [:a2, :b2, :c2], [:a3, :b3, :c3]]
+ *    pp d
+ *    # =>
+ *    [[:a0, :b0, :c0],
+ *     [:a1, :b1, :c1],
+ *     [:a2, :b2, :c2],
+ *     [:a3, :b3, :c3]]
  *
- *  If any array in +other_arrays+ is smaller than +self+,
- *  fills to <tt>self.size</tt> with +nil+:
+ *  When one of the other arrays is smaller than +self+,
+ *  pads the corresponding sub-array with +nil+ elements:
  *
  *    a = [:a0, :a1, :a2, :a3]
  *    b = [:b0, :b1, :b2]
  *    c = [:c0, :c1]
  *    d = a.zip(b, c)
- *    d # => [[:a0, :b0, :c0], [:a1, :b1, :c1], [:a2, :b2, nil], [:a3, nil, nil]]
+ *    pp d
+ *    # =>
+ *    [[:a0, :b0, :c0],
+ *     [:a1, :b1, :c1],
+ *     [:a2, :b2, nil],
+ *     [:a3, nil, nil]]
  *
- *  If any array in +other_arrays+ is larger than +self+,
- *  its trailing elements are ignored:
+ *  When one of the other arrays is larger than +self+,
+ *  _ignores_ its trailing elements:
  *
  *    a = [:a0, :a1, :a2, :a3]
  *    b = [:b0, :b1, :b2, :b3, :b4]
  *    c = [:c0, :c1, :c2, :c3, :c4, :c5]
  *    d = a.zip(b, c)
- *    d # => [[:a0, :b0, :c0], [:a1, :b1, :c1], [:a2, :b2, :c2], [:a3, :b3, :c3]]
+ *    pp d
+ *    # =>
+ *    [[:a0, :b0, :c0],
+ *     [:a1, :b1, :c1],
+ *     [:a2, :b2, :c2],
+ *     [:a3, :b3, :c3]]
  *
- *  When a block is given, calls the block with each of the sub-arrays (formed as above); returns +nil+:
+ *  With a block given, calls the block with each of the other arrays;
+ *  returns +nil+:
  *
+ *    d = []
  *    a = [:a0, :a1, :a2, :a3]
  *    b = [:b0, :b1, :b2, :b3]
  *    c = [:c0, :c1, :c2, :c3]
- *    a.zip(b, c) {|sub_array| p sub_array} # => nil
- *
- *  Output:
- *
- *    [:a0, :b0, :c0]
- *    [:a1, :b1, :c1]
- *    [:a2, :b2, :c2]
- *    [:a3, :b3, :c3]
- *
+ *    a.zip(b, c) {|sub_array| d.push(sub_array.reverse) } # => nil
+ *    pp d
+ *    # =>
+ *    [[:c0, :b0, :a0],
+ *     [:c1, :b1, :a1],
+ *     [:c2, :b2, :a2],
+ *     [:c3, :b3, :a3]]
+ *
+ *  For an *object* in *other_arrays* that is not actually an array,
+ *  forms the "other array" as <tt>object.to_ary</tt>, if defined,
+ *  or as <tt>object.each.to_a</tt> otherwise.
+ *
+ *  Related: see {Methods for Converting}[rdoc-ref:Array@Methods+for+Converting].
  */
 
 static VALUE
@@ -4469,14 +4744,17 @@ rb_ary_zip(int argc, VALUE *argv, VALUE ary)
 
 /*
  *  call-seq:
- *    array.transpose -> new_array
+ *    transpose -> new_array
  *
- *  Transposes the rows and columns in an \Array of Arrays;
- *  the nested Arrays must all be the same size:
+ *  Returns a new array that is +self+
+ *  as a {transposed matrix}[https://en.wikipedia.org/wiki/Transpose]:
  *
  *    a = [[:a0, :a1], [:b0, :b1], [:c0, :c1]]
  *    a.transpose # => [[:a0, :b0, :c0], [:a1, :b1, :c1]]
  *
+ *  The elements of +self+ must all be the same size.
+ *
+ *  Related: see {Methods for Converting}[rdoc-ref:Array@Methods+for+Converting].
  */
 
 static VALUE
@@ -4509,13 +4787,17 @@ rb_ary_transpose(VALUE ary)
 
 /*
  *  call-seq:
- *    array.replace(other_array) -> self
+ *    initialize_copy(other_array) -> self
+ *    replace(other_array) -> self
  *
- *  Replaces the content of +self+ with the content of +other_array+; returns +self+:
+ *  Replaces the elements of +self+ with the elements of +other_array+, which must be an
+ *  {array-convertible object}[rdoc-ref:implicit_conversion.rdoc@Array-Convertible+Objects];
+ *  returns +self+:
  *
- *    a = [:foo, 'bar', 2]
- *    a.replace(['foo', :bar, 3]) # => ["foo", :bar, 3]
+ *    a = ['a', 'b', 'c']   # => ["a", "b", "c"]
+ *    a.replace(['d', 'e']) # => ["d", "e"]
  *
+ *  Related: see {Methods for Assigning}[rdoc-ref:Array@Methods+for+Assigning].
  */
 
 VALUE
@@ -4529,7 +4811,7 @@ rb_ary_replace(VALUE copy, VALUE orig)
 
     /* orig has enough space to embed the contents of orig. */
     if (RARRAY_LEN(orig) <= ary_embed_capa(copy)) {
-        assert(ARY_EMBED_P(copy));
+        RUBY_ASSERT(ARY_EMBED_P(copy));
         ary_memcpy(copy, 0, RARRAY_LEN(orig), RARRAY_CONST_PTR(orig));
         ARY_SET_EMBED_LEN(copy, RARRAY_LEN(orig));
     }
@@ -4537,7 +4819,7 @@ rb_ary_replace(VALUE copy, VALUE orig)
      * contents of orig. */
     else if (ARY_EMBED_P(orig)) {
         long len = ARY_EMBED_LEN(orig);
-        VALUE *ptr = ary_heap_alloc(len);
+        VALUE *ptr = ary_heap_alloc_buffer(len);
 
         FL_UNSET_EMBED(copy);
         ARY_SET_PTR(copy, ptr);
@@ -4556,6 +4838,8 @@ rb_ary_replace(VALUE copy, VALUE orig)
         ARY_SET_PTR(copy, ARY_HEAP_PTR(orig));
         ARY_SET_LEN(copy, ARY_HEAP_LEN(orig));
         rb_ary_set_shared(copy, shared_root);
+
+        RUBY_ASSERT(RB_OBJ_SHAREABLE_P(copy) ? RB_OBJ_SHAREABLE_P(shared_root) : 1);
     }
     ary_verify(copy);
     return copy;
@@ -4563,13 +4847,14 @@ rb_ary_replace(VALUE copy, VALUE orig)
 
 /*
  *  call-seq:
- *     array.clear -> self
+ *    clear -> self
  *
- *  Removes all elements from +self+:
+ *  Removes all elements from +self+; returns +self+:
  *
  *    a = [:foo, 'bar', 2]
  *    a.clear # => []
  *
+ *  Related: see {Methods for Deleting}[rdoc-ref:Array@Methods+for+Deleting].
  */
 
 VALUE
@@ -4577,11 +4862,9 @@ rb_ary_clear(VALUE ary)
 {
     rb_ary_modify_check(ary);
     if (ARY_SHARED_P(ary)) {
-        if (!ARY_EMBED_P(ary)) {
-            rb_ary_unshare(ary);
-            FL_SET_EMBED(ary);
-            ARY_SET_EMBED_LEN(ary, 0);
-        }
+        rb_ary_unshare(ary);
+        FL_SET_EMBED(ary);
+        ARY_SET_EMBED_LEN(ary, 0);
     }
     else {
         ARY_SET_LEN(ary, 0);
@@ -4595,198 +4878,182 @@ rb_ary_clear(VALUE ary)
 
 /*
  *  call-seq:
- *    array.fill(obj) -> self
- *    array.fill(obj, start) -> self
- *    array.fill(obj, start, length) -> self
- *    array.fill(obj, range) -> self
- *    array.fill {|index| ... } -> self
- *    array.fill(start) {|index| ... } -> self
- *    array.fill(start, length) {|index| ... } -> self
- *    array.fill(range) {|index| ... } -> self
+ *    fill(object, start = nil, count = nil) -> self
+ *    fill(object, range) -> self
+ *    fill(start = nil, count = nil) {|element| ... } -> self
+ *    fill(range) {|element| ... } -> self
  *
- *  Replaces specified elements in +self+ with specified objects; returns +self+.
+ *  Replaces selected elements in +self+;
+ *  may add elements to +self+;
+ *  always returns +self+ (never a new array).
  *
- *  With argument +obj+ and no block given, replaces all elements with that one object:
+ *  In brief:
  *
- *    a = ['a', 'b', 'c', 'd']
- *    a # => ["a", "b", "c", "d"]
- *    a.fill(:X) # => [:X, :X, :X, :X]
+ *    # Non-negative start.
+ *    ['a', 'b', 'c', 'd'].fill('-', 1, 2)          # => ["a", "-", "-", "d"]
+ *    ['a', 'b', 'c', 'd'].fill(1, 2) {|e| e.to_s } # => ["a", "1", "2", "d"]
  *
- *  With arguments +obj+ and Integer +start+, and no block given,
- *  replaces elements based on the given start.
+ *    # Extends with specified values if necessary.
+ *    ['a', 'b', 'c', 'd'].fill('-', 3, 2)          # => ["a", "b", "c", "-", "-"]
+ *    ['a', 'b', 'c', 'd'].fill(3, 2) {|e| e.to_s } # => ["a", "b", "c", "3", "4"]
  *
- *  If +start+ is in range (<tt>0 <= start < array.size</tt>),
- *  replaces all elements from offset +start+ through the end:
+ *    # Fills with nils if necessary.
+ *    ['a', 'b', 'c', 'd'].fill('-', 6, 2)          # => ["a", "b", "c", "d", nil, nil, "-", "-"]
+ *    ['a', 'b', 'c', 'd'].fill(6, 2) {|e| e.to_s } # => ["a", "b", "c", "d", nil, nil, "6", "7"]
  *
- *    a = ['a', 'b', 'c', 'd']
- *    a.fill(:X, 2) # => ["a", "b", :X, :X]
+ *    # For negative start, counts backwards from the end.
+ *    ['a', 'b', 'c', 'd'].fill('-', -3, 3)          # => ["a", "-", "-", "-"]
+ *    ['a', 'b', 'c', 'd'].fill(-3, 3) {|e| e.to_s } # => ["a", "1", "2", "3"]
  *
- *  If +start+ is too large (<tt>start >= array.size</tt>), does nothing:
+ *    # Range.
+ *    ['a', 'b', 'c', 'd'].fill('-', 1..2)          # => ["a", "-", "-", "d"]
+ *    ['a', 'b', 'c', 'd'].fill(1..2) {|e| e.to_s } # => ["a", "1", "2", "d"]
  *
- *    a = ['a', 'b', 'c', 'd']
- *    a.fill(:X, 4) # => ["a", "b", "c", "d"]
- *    a = ['a', 'b', 'c', 'd']
- *    a.fill(:X, 5) # => ["a", "b", "c", "d"]
+ *  When arguments +start+ and +count+ are given,
+ *  they select the elements of +self+ to be replaced;
+ *  each must be an
+ *  {integer-convertible object}[rdoc-ref:implicit_conversion.rdoc@Integer-Convertible+Objects]
+ *  (or +nil+):
  *
- *  If +start+ is negative, counts from the end (starting index is <tt>start + array.size</tt>):
+ *  - +start+ specifies the zero-based offset of the first element to be replaced;
+ *    +nil+ means zero.
+ *  - +count+ is the number of consecutive elements to be replaced;
+ *    +nil+ means "all the rest."
  *
- *    a = ['a', 'b', 'c', 'd']
- *    a.fill(:X, -2) # => ["a", "b", :X, :X]
+ *  With argument +object+ given,
+ *  that one object is used for all replacements:
  *
- *  If +start+ is too small (less than and far from zero), replaces all elements:
+ *    o = Object.new           # => #<Object:0x0000014e7bff7600>
+ *    a = ['a', 'b', 'c', 'd'] # => ["a", "b", "c", "d"]
+ *    a.fill(o, 1, 2)
+ *    # => ["a", #<Object:0x0000014e7bff7600>, #<Object:0x0000014e7bff7600>, "d"]
  *
- *    a = ['a', 'b', 'c', 'd']
- *    a.fill(:X, -6) # => [:X, :X, :X, :X]
- *    a = ['a', 'b', 'c', 'd']
- *    a.fill(:X, -50) # => [:X, :X, :X, :X]
+ *  With a block given, the block is called once for each element to be replaced;
+ *  the value passed to the block is the _index_ of the element to be replaced
+ *  (not the element itself);
+ *  the block's return value replaces the element:
  *
- *  With arguments +obj+, Integer +start+, and Integer +length+, and no block given,
- *  replaces elements based on the given +start+ and +length+.
+ *    a = ['a', 'b', 'c', 'd']               # => ["a", "b", "c", "d"]
+ *    a.fill(1, 2) {|element| element.to_s } # => ["a", "1", "2", "d"]
  *
- *  If +start+ is in range, replaces +length+ elements beginning at offset +start+:
+ *  For arguments +start+ and +count+:
  *
- *    a = ['a', 'b', 'c', 'd']
- *    a.fill(:X, 1, 1) # => ["a", :X, "c", "d"]
+ *  - If +start+ is non-negative,
+ *    replaces +count+ elements beginning at offset +start+:
  *
- *  If +start+ is negative, counts from the end:
+ *      ['a', 'b', 'c', 'd'].fill('-', 0, 2) # => ["-", "-", "c", "d"]
+ *      ['a', 'b', 'c', 'd'].fill('-', 1, 2) # => ["a", "-", "-", "d"]
+ *      ['a', 'b', 'c', 'd'].fill('-', 2, 2) # => ["a", "b", "-", "-"]
  *
- *    a = ['a', 'b', 'c', 'd']
- *    a.fill(:X, -2, 1) # => ["a", "b", :X, "d"]
+ *      ['a', 'b', 'c', 'd'].fill(0, 2) {|e| e.to_s } # => ["0", "1", "c", "d"]
+ *      ['a', 'b', 'c', 'd'].fill(1, 2) {|e| e.to_s } # => ["a", "1", "2", "d"]
+ *      ['a', 'b', 'c', 'd'].fill(2, 2) {|e| e.to_s } # => ["a", "b", "2", "3"]
  *
- *  If +start+ is large (<tt>start >= array.size</tt>), extends +self+ with +nil+:
+ *    Extends +self+ if necessary:
  *
- *    a = ['a', 'b', 'c', 'd']
- *    a.fill(:X, 5, 0) # => ["a", "b", "c", "d", nil]
- *    a = ['a', 'b', 'c', 'd']
- *    a.fill(:X, 5, 2) # => ["a", "b", "c", "d", nil, :X, :X]
+ *      ['a', 'b', 'c', 'd'].fill('-', 3, 2) # => ["a", "b", "c", "-", "-"]
+ *      ['a', 'b', 'c', 'd'].fill('-', 4, 2) # => ["a", "b", "c", "d", "-", "-"]
  *
- *  If +length+ is zero or negative, replaces no elements:
+ *      ['a', 'b', 'c', 'd'].fill(3, 2) {|e| e.to_s } # => ["a", "b", "c", "3", "4"]
+ *      ['a', 'b', 'c', 'd'].fill(4, 2) {|e| e.to_s } # => ["a", "b", "c", "d", "4", "5"]
  *
- *    a = ['a', 'b', 'c', 'd']
- *    a.fill(:X, 1, 0) # => ["a", "b", "c", "d"]
- *    a.fill(:X, 1, -1) # => ["a", "b", "c", "d"]
+ *    Fills with +nil+ if necessary:
  *
- *  With arguments +obj+ and Range +range+, and no block given,
- *  replaces elements based on the given range.
+ *      ['a', 'b', 'c', 'd'].fill('-', 5, 2) # => ["a", "b", "c", "d", nil, "-", "-"]
+ *      ['a', 'b', 'c', 'd'].fill('-', 6, 2) # => ["a", "b", "c", "d", nil, nil, "-", "-"]
  *
- *  If the range is positive and ascending (<tt>0 < range.begin <= range.end</tt>),
- *  replaces elements from <tt>range.begin</tt> to <tt>range.end</tt>:
+ *      ['a', 'b', 'c', 'd'].fill(5, 2) {|e| e.to_s } # => ["a", "b", "c", "d", nil, "5", "6"]
+ *      ['a', 'b', 'c', 'd'].fill(6, 2) {|e| e.to_s } # => ["a", "b", "c", "d", nil, nil, "6", "7"]
  *
- *    a = ['a', 'b', 'c', 'd']
- *    a.fill(:X, (1..1)) # => ["a", :X, "c", "d"]
+ *    Does nothing if +count+ is non-positive:
  *
- *  If <tt>range.first</tt> is negative, replaces no elements:
+ *      ['a', 'b', 'c', 'd'].fill('-', 2, 0)    # => ["a", "b", "c", "d"]
+ *      ['a', 'b', 'c', 'd'].fill('-', 2, -100) # => ["a", "b", "c", "d"]
+ *      ['a', 'b', 'c', 'd'].fill('-', 6, -100) # => ["a", "b", "c", "d"]
  *
- *    a = ['a', 'b', 'c', 'd']
- *    a.fill(:X, (-1..1)) # => ["a", "b", "c", "d"]
+ *      ['a', 'b', 'c', 'd'].fill(2, 0) {|e| fail 'Cannot happen' }    # => ["a", "b", "c", "d"]
+ *      ['a', 'b', 'c', 'd'].fill(2, -100) {|e| fail 'Cannot happen' } # => ["a", "b", "c", "d"]
+ *      ['a', 'b', 'c', 'd'].fill(6, -100) {|e| fail 'Cannot happen' } # => ["a", "b", "c", "d"]
  *
- *  If <tt>range.last</tt> is negative, counts from the end:
+ *  - If +start+ is negative, counts backwards from the end of +self+:
  *
- *    a = ['a', 'b', 'c', 'd']
- *    a.fill(:X, (0..-2)) # => [:X, :X, :X, "d"]
- *    a = ['a', 'b', 'c', 'd']
- *    a.fill(:X, (1..-2)) # => ["a", :X, :X, "d"]
+ *      ['a', 'b', 'c', 'd'].fill('-', -4, 3) # => ["-", "-", "-", "d"]
+ *      ['a', 'b', 'c', 'd'].fill('-', -3, 3) # => ["a", "-", "-", "-"]
  *
- *  If <tt>range.last</tt> and <tt>range.last</tt> are both negative,
- *  both count from the end of the array:
+ *      ['a', 'b', 'c', 'd'].fill(-4, 3) {|e| e.to_s } # => ["0", "1", "2", "d"]
+ *      ['a', 'b', 'c', 'd'].fill(-3, 3) {|e| e.to_s } # => ["a", "1", "2", "3"]
  *
- *    a = ['a', 'b', 'c', 'd']
- *    a.fill(:X, (-1..-1)) # => ["a", "b", "c", :X]
- *    a = ['a', 'b', 'c', 'd']
- *    a.fill(:X, (-2..-2)) # => ["a", "b", :X, "d"]
+ *    Extends +self+ if necessary:
  *
- *  With no arguments and a block given, calls the block with each index;
- *  replaces the corresponding element with the block's return value:
+ *      ['a', 'b', 'c', 'd'].fill('-', -2, 3) # => ["a", "b", "-", "-", "-"]
+ *      ['a', 'b', 'c', 'd'].fill('-', -1, 3) # => ["a", "b", "c", "-", "-", "-"]
  *
- *    a = ['a', 'b', 'c', 'd']
- *    a.fill { |index| "new_#{index}" } # => ["new_0", "new_1", "new_2", "new_3"]
+ *      ['a', 'b', 'c', 'd'].fill(-2, 3) {|e| e.to_s } # => ["a", "b", "2", "3", "4"]
+ *      ['a', 'b', 'c', 'd'].fill(-1, 3) {|e| e.to_s } # => ["a", "b", "c", "3", "4", "5"]
  *
- *  With argument +start+ and a block given, calls the block with each index
- *  from offset +start+ to the end; replaces the corresponding element
- *  with the block's return value.
+ *    Starts at the beginning of +self+ if +start+ is negative and out-of-range:
  *
- *  If start is in range (<tt>0 <= start < array.size</tt>),
- *  replaces from offset +start+ to the end:
+ *      ['a', 'b', 'c', 'd'].fill('-', -5, 2) # => ["-", "-", "c", "d"]
+ *      ['a', 'b', 'c', 'd'].fill('-', -6, 2) # => ["-", "-", "c", "d"]
  *
- *    a = ['a', 'b', 'c', 'd']
- *    a.fill(1) { |index| "new_#{index}" } # => ["a", "new_1", "new_2", "new_3"]
+ *      ['a', 'b', 'c', 'd'].fill(-5, 2) {|e| e.to_s } # => ["0", "1", "c", "d"]
+ *      ['a', 'b', 'c', 'd'].fill(-6, 2) {|e| e.to_s } # => ["0", "1", "c", "d"]
  *
- *  If +start+ is too large(<tt>start >= array.size</tt>), does nothing:
+ *    Does nothing if +count+ is non-positive:
  *
- *    a = ['a', 'b', 'c', 'd']
- *    a.fill(4) { |index| fail 'Cannot happen' } # => ["a", "b", "c", "d"]
- *    a = ['a', 'b', 'c', 'd']
- *    a.fill(4) { |index| fail 'Cannot happen' } # => ["a", "b", "c", "d"]
+ *      ['a', 'b', 'c', 'd'].fill('-', -2, 0)  # => ["a", "b", "c", "d"]
+ *      ['a', 'b', 'c', 'd'].fill('-', -2, -1) # => ["a", "b", "c", "d"]
  *
- *  If +start+ is negative, counts from the end:
+ *      ['a', 'b', 'c', 'd'].fill(-2, 0) {|e| fail 'Cannot happen' }  # => ["a", "b", "c", "d"]
+ *      ['a', 'b', 'c', 'd'].fill(-2, -1) {|e| fail 'Cannot happen' } # => ["a", "b", "c", "d"]
  *
- *    a = ['a', 'b', 'c', 'd']
- *    a.fill(-2) { |index| "new_#{index}" } # => ["a", "b", "new_2", "new_3"]
+ *  When argument +range+ is given,
+ *  it must be a Range object whose members are numeric;
+ *  its +begin+ and +end+ values determine the elements of +self+
+ *  to be replaced:
  *
- *  If start is too small (<tt>start <= -array.size</tt>, replaces all elements:
+ *  - If both +begin+ and +end+ are positive, they specify the first and last elements
+ *    to be replaced:
  *
- *    a = ['a', 'b', 'c', 'd']
- *    a.fill(-6) { |index| "new_#{index}" } # => ["new_0", "new_1", "new_2", "new_3"]
- *    a = ['a', 'b', 'c', 'd']
- *    a.fill(-50) { |index| "new_#{index}" } # => ["new_0", "new_1", "new_2", "new_3"]
- *
- *  With arguments +start+ and +length+, and a block given,
- *  calls the block for each index specified by start length;
- *  replaces the corresponding element with the block's return value.
+ *      ['a', 'b', 'c', 'd'].fill('-', 1..2)          # => ["a", "-", "-", "d"]
+ *      ['a', 'b', 'c', 'd'].fill(1..2) {|e| e.to_s } # => ["a", "1", "2", "d"]
  *
- *  If +start+ is in range, replaces +length+ elements beginning at offset +start+:
+ *    If +end+ is smaller than +begin+, replaces no elements:
  *
- *    a = ['a', 'b', 'c', 'd']
- *    a.fill(1, 1) { |index| "new_#{index}" } # => ["a", "new_1", "c", "d"]
+ *      ['a', 'b', 'c', 'd'].fill('-', 2..1)          # => ["a", "b", "c", "d"]
+ *      ['a', 'b', 'c', 'd'].fill(2..1) {|e| e.to_s } # => ["a", "b", "c", "d"]
  *
- *  If start is negative, counts from the end:
- *
- *    a = ['a', 'b', 'c', 'd']
- *    a.fill(-2, 1) { |index| "new_#{index}" } # => ["a", "b", "new_2", "d"]
+ *  - If either is negative (or both are negative), counts backwards from the end of +self+:
  *
- *  If +start+ is large (<tt>start >= array.size</tt>), extends +self+ with +nil+:
+ *      ['a', 'b', 'c', 'd'].fill('-', -3..2)  # => ["a", "-", "-", "d"]
+ *      ['a', 'b', 'c', 'd'].fill('-', 1..-2)  # => ["a", "-", "-", "d"]
+ *      ['a', 'b', 'c', 'd'].fill('-', -3..-2) # => ["a", "-", "-", "d"]
  *
- *    a = ['a', 'b', 'c', 'd']
- *    a.fill(5, 0) { |index| "new_#{index}" } # => ["a", "b", "c", "d", nil]
- *    a = ['a', 'b', 'c', 'd']
- *    a.fill(5, 2) { |index| "new_#{index}" } # => ["a", "b", "c", "d", nil, "new_5", "new_6"]
+ *      ['a', 'b', 'c', 'd'].fill(-3..2) {|e| e.to_s }  # => ["a", "1", "2", "d"]
+ *      ['a', 'b', 'c', 'd'].fill(1..-2) {|e| e.to_s }  # => ["a", "1", "2", "d"]
+ *      ['a', 'b', 'c', 'd'].fill(-3..-2) {|e| e.to_s } # => ["a", "1", "2", "d"]
  *
- *  If +length+ is zero or less, replaces no elements:
+ *  - If the +end+ value is excluded (see Range#exclude_end?), omits the last replacement:
  *
- *    a = ['a', 'b', 'c', 'd']
- *    a.fill(1, 0) { |index| "new_#{index}" } # => ["a", "b", "c", "d"]
- *    a.fill(1, -1) { |index| "new_#{index}" } # => ["a", "b", "c", "d"]
+ *      ['a', 'b', 'c', 'd'].fill('-', 1...2)  # => ["a", "-", "c", "d"]
+ *      ['a', 'b', 'c', 'd'].fill('-', 1...-2) # => ["a", "-", "c", "d"]
  *
- *  With arguments +obj+ and +range+, and a block given,
- *  calls the block with each index in the given range;
- *  replaces the corresponding element with the block's return value.
+ *      ['a', 'b', 'c', 'd'].fill(1...2) {|e| e.to_s }  # => ["a", "1", "c", "d"]
+ *      ['a', 'b', 'c', 'd'].fill(1...-2) {|e| e.to_s } # => ["a", "1", "c", "d"]
  *
- *  If the range is positive and ascending (<tt>range 0 < range.begin <= range.end</tt>,
- *  replaces elements from <tt>range.begin</tt> to <tt>range.end</tt>:
+ *  - If the range is endless (see {Endless Ranges}[rdoc-ref:Range@Endless+Ranges]),
+ *    replaces elements to the end of +self+:
  *
- *    a = ['a', 'b', 'c', 'd']
- *    a.fill(1..1) { |index| "new_#{index}" } # => ["a", "new_1", "c", "d"]
+ *      ['a', 'b', 'c', 'd'].fill('-', 1..)          # => ["a", "-", "-", "-"]
+ *      ['a', 'b', 'c', 'd'].fill(1..) {|e| e.to_s } # => ["a", "1", "2", "3"]
  *
- *  If +range.first+ is negative, does nothing:
+ *  - If the range is beginless (see {Beginless Ranges}[rdoc-ref:Range@Beginless+Ranges]),
+ *    replaces elements from the beginning of +self+:
  *
- *    a = ['a', 'b', 'c', 'd']
- *    a.fill(-1..1) { |index| fail 'Cannot happen' } # => ["a", "b", "c", "d"]
- *
- *  If <tt>range.last</tt> is negative, counts from the end:
- *
- *    a = ['a', 'b', 'c', 'd']
- *    a.fill(0..-2) { |index| "new_#{index}" } # => ["new_0", "new_1", "new_2", "d"]
- *    a = ['a', 'b', 'c', 'd']
- *    a.fill(1..-2) { |index| "new_#{index}" } # => ["a", "new_1", "new_2", "d"]
- *
- *  If <tt>range.first</tt> and <tt>range.last</tt> are both negative,
- *  both count from the end:
- *
- *    a = ['a', 'b', 'c', 'd']
- *    a.fill(-1..-1) { |index| "new_#{index}" } # => ["a", "b", "c", "new_3"]
- *    a = ['a', 'b', 'c', 'd']
- *    a.fill(-2..-2) { |index| "new_#{index}" } # => ["a", "b", "new_2", "d"]
+ *      ['a', 'b', 'c', 'd'].fill('-', ..2)          # => ["-", "-", "-", "d"]
+ *      ['a', 'b', 'c', 'd'].fill(..2) {|e| e.to_s } # => ["0", "1", "2", "d"]
  *
+ *  Related: see {Methods for Assigning}[rdoc-ref:Array@Methods+for+Assigning].
  */
 
 static VALUE
@@ -4855,15 +5122,15 @@ rb_ary_fill(int argc, VALUE *argv, VALUE ary)
 
 /*
  *  call-seq:
- *    array + other_array -> new_array
+ *    self + other_array -> new_array
  *
- *  Returns a new \Array containing all elements of +array+
+ *  Returns a new array containing all elements of +self+
  *  followed by all elements of +other_array+:
  *
  *    a = [0, 1] + [2, 3]
  *    a # => [0, 1, 2, 3]
  *
- *  Related: #concat.
+ *  Related: see {Methods for Combining}[rdoc-ref:Array@Methods+for+Combining].
  */
 
 VALUE
@@ -4897,12 +5164,15 @@ ary_append(VALUE x, VALUE y)
 
 /*
  *  call-seq:
- *    array.concat(*other_arrays) -> self
+ *    concat(*other_arrays) -> self
  *
- *  Adds to +array+ all elements from each \Array in +other_arrays+; returns +self+:
+ *  Adds to +self+ all elements from each array in +other_arrays+; returns +self+:
  *
  *    a = [0, 1]
- *    a.concat([2, 3], [4, 5]) # => [0, 1, 2, 3, 4, 5]
+ *    a.concat(['two', 'three'], [:four, :five], a)
+ *    # => [0, 1, "two", "three", :four, :five, 0, 1]
+ *
+ *  Related: see {Methods for Assigning}[rdoc-ref:Array@Methods+for+Assigning].
  */
 
 static VALUE
@@ -4934,19 +5204,19 @@ rb_ary_concat(VALUE x, VALUE y)
 
 /*
  *  call-seq:
- *    array * n -> new_array
- *    array * string_separator -> new_string
+ *    self * n -> new_array
+ *    self * string_separator -> new_string
  *
- *  When non-negative argument Integer +n+ is given,
- *  returns a new \Array built by concatenating the +n+ copies of +self+:
+ *  When non-negative integer argument +n+ is given,
+ *  returns a new array built by concatenating +n+ copies of +self+:
  *
  *    a = ['x', 'y']
  *    a * 3 # => ["x", "y", "x", "y", "x", "y"]
  *
- *  When String argument +string_separator+ is given,
- *  equivalent to <tt>array.join(string_separator)</tt>:
+ *  When string argument +string_separator+ is given,
+ *  equivalent to <tt>self.join(string_separator)</tt>:
  *
- *    [0, [0, 1], {foo: 0}] * ', ' # => "0, 0, 1, {:foo=>0}"
+ *    [0, [0, 1], {foo: 0}] * ', ' # => "0, 0, 1, {foo: 0}"
  *
  */
 
@@ -4996,17 +5266,18 @@ rb_ary_times(VALUE ary, VALUE times)
 
 /*
  *  call-seq:
- *    array.assoc(obj) -> found_array or nil
+ *    assoc(object) -> found_array or nil
  *
- *  Returns the first element in +self+ that is an \Array
- *  whose first element <tt>==</tt> +obj+:
+ *  Returns the first element +ele+ in +self+ such that +ele+ is an array
+ *  and <tt>ele[0] == object</tt>:
  *
  *    a = [{foo: 0}, [2, 4], [4, 5, 6], [4, 5]]
  *    a.assoc(4) # => [4, 5, 6]
  *
  *  Returns +nil+ if no such element is found.
  *
- *  Related: #rassoc.
+ *  Related: Array#rassoc;
+ *  see also {Methods for Fetching}[rdoc-ref:Array@Methods+for+Fetching].
  */
 
 VALUE
@@ -5026,17 +5297,19 @@ rb_ary_assoc(VALUE ary, VALUE key)
 
 /*
  *  call-seq:
- *    array.rassoc(obj) -> found_array or nil
+ *    rassoc(object) -> found_array or nil
  *
- *  Returns the first element in +self+ that is an \Array
- *  whose second element <tt>==</tt> +obj+:
+ *  Returns the first element +ele+ in +self+ such that +ele+ is an array
+ *  and <tt>ele[1] == object</tt>:
  *
  *    a = [{foo: 0}, [2, 4], [4, 5, 6], [4, 5]]
  *    a.rassoc(4) # => [2, 4]
+ *    a.rassoc(5) # => [4, 5, 6]
  *
  *  Returns +nil+ if no such element is found.
  *
- *  Related: #assoc.
+ *  Related: Array#assoc;
+ *  see also {Methods for Fetching}[rdoc-ref:Array@Methods+for+Fetching].
  */
 
 VALUE
@@ -5046,7 +5319,7 @@ rb_ary_rassoc(VALUE ary, VALUE value)
     VALUE v;
 
     for (i = 0; i < RARRAY_LEN(ary); ++i) {
-        v = RARRAY_AREF(ary, i);
+        v = rb_check_array_type(RARRAY_AREF(ary, i));
         if (RB_TYPE_P(v, T_ARRAY) &&
             RARRAY_LEN(v) > 1 &&
             rb_equal(RARRAY_AREF(v, 1), value))
@@ -5091,20 +5364,26 @@ recursive_equal(VALUE ary1, VALUE ary2, int recur)
 
 /*
  *  call-seq:
- *    array == other_array -> true or false
+ *    self == other_array -> true or false
  *
- *  Returns +true+ if both <tt>array.size == other_array.size</tt>
- *  and for each index +i+ in +array+, <tt>array[i] == other_array[i]</tt>:
+ *  Returns whether both:
  *
- *    a0 = [:foo, 'bar', 2]
- *    a1 = [:foo, 'bar', 2.0]
- *    a1 == a0 # => true
- *    [] == [] # => true
+ *  - +self+ and +other_array+ are the same size.
+ *  - Their corresponding elements are the same;
+ *    that is, for each index +i+ in <tt>(0...self.size)</tt>,
+ *    <tt>self[i] == other_array[i]</tt>.
  *
- *  Otherwise, returns +false+.
+ *  Examples:
+ *
+ *    [:foo, 'bar', 2] == [:foo, 'bar', 2]   # => true
+ *    [:foo, 'bar', 2] == [:foo, 'bar', 2.0] # => true
+ *    [:foo, 'bar', 2] == [:foo, 'bar']      # => false # Different sizes.
+ *    [:foo, 'bar', 2] == [:foo, 'bar', 3]   # => false # Different elements.
  *
  *  This method is different from method Array#eql?,
  *  which compares elements using <tt>Object#eql?</tt>.
+ *
+ *  Related: see {Methods for Comparing}[rdoc-ref:Array@Methods+for+Comparing].
  */
 
 static VALUE
@@ -5137,10 +5416,10 @@ recursive_eql(VALUE ary1, VALUE ary2, int recur)
 
 /*
  *  call-seq:
- *    array.eql? other_array -> true or false
+ *    eql?(other_array) -> true or false
  *
  *  Returns +true+ if +self+ and +other_array+ are the same size,
- *  and if, for each index +i+ in +self+, <tt>self[i].eql? other_array[i]</tt>:
+ *  and if, for each index +i+ in +self+, <tt>self[i].eql?(other_array[i])</tt>:
  *
  *    a0 = [:foo, 'bar', 2]
  *    a1 = [:foo, 'bar', 2]
@@ -5150,6 +5429,8 @@ recursive_eql(VALUE ary1, VALUE ary2, int recur)
  *
  *  This method is different from method Array#==,
  *  which compares using method <tt>Object#==</tt>.
+ *
+ *  Related: see {Methods for Querying}[rdoc-ref:Array@Methods+for+Querying].
  */
 
 static VALUE
@@ -5162,8 +5443,8 @@ rb_ary_eql(VALUE ary1, VALUE ary2)
     return rb_exec_recursive_paired(recursive_eql, ary1, ary2, ary2);
 }
 
-VALUE
-rb_ary_hash_values(long len, const VALUE *elements)
+static VALUE
+ary_hash_values(long len, const VALUE *elements, const VALUE ary)
 {
     long i;
     st_index_t h;
@@ -5174,39 +5455,55 @@ rb_ary_hash_values(long len, const VALUE *elements)
     for (i=0; i<len; i++) {
         n = rb_hash(elements[i]);
         h = rb_hash_uint(h, NUM2LONG(n));
+        if (ary) {
+            len = RARRAY_LEN(ary);
+            elements = RARRAY_CONST_PTR(ary);
+        }
     }
     h = rb_hash_end(h);
     return ST2FIX(h);
 }
 
+VALUE
+rb_ary_hash_values(long len, const VALUE *elements)
+{
+    return ary_hash_values(len, elements, 0);
+}
+
 /*
  *  call-seq:
- *    array.hash -> integer
+ *    hash -> integer
  *
  *  Returns the integer hash value for +self+.
  *
- *  Two arrays with the same content will have the same hash code (and will compare using eql?):
+ *  Two arrays with the same content will have the same hash value
+ *  (and will compare using eql?):
  *
- *    [0, 1, 2].hash == [0, 1, 2].hash # => true
- *    [0, 1, 2].hash == [0, 1, 3].hash # => false
+ *    ['a', 'b'].hash == ['a', 'b'].hash # => true
+ *    ['a', 'b'].hash == ['a', 'c'].hash # => false
+ *    ['a', 'b'].hash == ['a'].hash      # => false
  *
  */
 
 static VALUE
 rb_ary_hash(VALUE ary)
 {
-    return rb_ary_hash_values(RARRAY_LEN(ary), RARRAY_CONST_PTR(ary));
+    RBIMPL_ASSERT_OR_ASSUME(ary);
+    return ary_hash_values(RARRAY_LEN(ary), RARRAY_CONST_PTR(ary), ary);
 }
 
 /*
  *  call-seq:
- *    array.include?(obj) -> true or false
+ *    include?(object) -> true or false
+ *
+ *  Returns whether for some element +element+ in +self+,
+ *  <tt>object == element</tt>:
  *
- *  Returns +true+ if for some index +i+ in +self+, <tt>obj == self[i]</tt>;
- *  otherwise +false+:
+ *    [0, 1, 2].include?(2)   # => true
+ *    [0, 1, 2].include?(2.0) # => true
+ *    [0, 1, 2].include?(2.1) # => false
  *
- *    [0, 1, 2].include?(2) # => true
- *    [0, 1, 2].include?(3) # => false
+ *  Related: see {Methods for Querying}[rdoc-ref:Array@Methods+for+Querying].
  */
 
 VALUE
@@ -5261,33 +5558,40 @@ recursive_cmp(VALUE ary1, VALUE ary2, int recur)
 
 /*
  *  call-seq:
- *    array <=> other_array -> -1, 0, or 1
+ *    self <=> other_array -> -1, 0, or 1
  *
- *  Returns -1, 0, or 1 as +self+ is less than, equal to, or greater than +other_array+.
- *  For each index +i+ in +self+, evaluates <tt>result = self[i] <=> other_array[i]</tt>.
+ *  Returns -1, 0, or 1 as +self+ is determined
+ *  to be less than, equal to, or greater than +other_array+.
  *
- *  Returns -1 if any result is -1:
+ *  Iterates over each index +i+ in <tt>(0...self.size)</tt>:
  *
- *    [0, 1, 2] <=> [0, 1, 3] # => -1
+ *  - Computes <tt>result[i]</tt> as <tt>self[i] <=> other_array[i]</tt>.
+ *  - Immediately returns 1 if <tt>result[i]</tt> is 1:
  *
- *  Returns 1 if any result is 1:
+ *      [0, 1, 2] <=> [0, 0, 2] # => 1
  *
- *    [0, 1, 2] <=> [0, 1, 1] # => 1
+ *  - Immediately returns -1 if <tt>result[i]</tt> is -1:
  *
- *  When all results are zero:
+ *      [0, 1, 2] <=> [0, 2, 2] # => -1
  *
- *  - Returns -1 if +array+ is smaller than +other_array+:
+ *  - Continues if <tt>result[i]</tt> is 0.
  *
- *      [0, 1, 2] <=> [0, 1, 2, 3] # => -1
+ *  When every +result+ is 0,
+ *  returns <tt>self.size <=> other_array.size</tt>
+ *  (see Integer#<=>):
  *
- *  - Returns 1 if +array+ is larger than +other_array+:
+ *    [0, 1, 2] <=> [0, 1]        # => 1
+ *    [0, 1, 2] <=> [0, 1, 2]     # => 0
+ *    [0, 1, 2] <=> [0, 1, 2, 3]  # => -1
  *
- *      [0, 1, 2] <=> [0, 1] # => 1
+ *  Note that when +other_array+ is larger than +self+,
+ *  its trailing elements do not affect the result:
  *
- *  - Returns 0 if +array+ and +other_array+ are the same size:
- *
- *      [0, 1, 2] <=> [0, 1, 2] # => 0
+ *    [0, 1, 2] <=> [0, 1, 2, -3] # => -1
+ *    [0, 1, 2] <=> [0, 1, 2, 0]  # => -1
+ *    [0, 1, 2] <=> [0, 1, 2, 3]  # => -1
  *
+ *  Related: see {Methods for Comparing}[rdoc-ref:Array@Methods+for+Comparing].
  */
 
 VALUE
@@ -5357,18 +5661,20 @@ ary_make_hash_by(VALUE ary)
 
 /*
  *  call-seq:
- *    array - other_array -> new_array
+ *    self - other_array -> new_array
+ *
+ *  Returns a new array containing only those elements of +self+
+ *  that are not found in +other_array+;
+ *  the order from +self+ is preserved:
  *
- *  Returns a new \Array containing only those elements from +array+
- *  that are not found in \Array +other_array+;
- *  items are compared using <tt>eql?</tt>;
- *  the order from +array+ is preserved:
+ *    [0, 1, 1, 2, 1, 1, 3, 1, 1] - [1]             # => [0, 2, 3]
+ *    [0, 1, 1, 2, 1, 1, 3, 1, 1] - [3, 2, 0, :foo] # => [1, 1, 1, 1, 1, 1]
+ *    [0, 1, 2] - [:foo]                            # => [0, 1, 2]
  *
- *    [0, 1, 1, 2, 1, 1, 3, 1, 1] - [1] # => [0, 2, 3]
- *    [0, 1, 2, 3] - [3, 0] # => [1, 2]
- *    [0, 1, 2] - [4] # => [0, 1, 2]
+ *  Element are compared using method <tt>#eql?</tt>
+ *  (as defined in each element of +self+).
  *
- *  Related: Array#difference.
+ *  Related: see {Methods for Combining}[rdoc-ref:Array@Methods+for+Combining].
  */
 
 VALUE
@@ -5402,19 +5708,21 @@ rb_ary_diff(VALUE ary1, VALUE ary2)
 
 /*
  *  call-seq:
- *    array.difference(*other_arrays) -> new_array
+ *    difference(*other_arrays = []) -> new_array
  *
- *  Returns a new \Array containing only those elements from +self+
- *  that are not found in any of the Arrays +other_arrays+;
+ *  Returns a new array containing only those elements from +self+
+ *  that are not found in any of the given +other_arrays+;
  *  items are compared using <tt>eql?</tt>;  order from +self+ is preserved:
  *
  *    [0, 1, 1, 2, 1, 1, 3, 1, 1].difference([1]) # => [0, 2, 3]
- *    [0, 1, 2, 3].difference([3, 0], [1, 3]) # => [2]
- *    [0, 1, 2].difference([4]) # => [0, 1, 2]
+ *    [0, 1, 2, 3].difference([3, 0], [1, 3])     # => [2]
+ *    [0, 1, 2].difference([4])                   # => [0, 1, 2]
+ *    [0, 1, 2].difference                        # => [0, 1, 2]
  *
- *  Returns a copy of +self+ if no arguments given.
+ *  Returns a copy of +self+ if no arguments are given.
  *
- *  Related: Array#-.
+ *  Related: Array#-;
+ *  see also {Methods for Combining}[rdoc-ref:Array@Methods+for+Combining].
  */
 
 static VALUE
@@ -5438,7 +5746,7 @@ rb_ary_difference_multi(int argc, VALUE *argv, VALUE ary)
         VALUE elt = rb_ary_elt(ary, i);
         for (j = 0; j < argc; j++) {
             if (is_hash[j]) {
-                if (rb_hash_stlike_lookup(argv[j], RARRAY_AREF(ary, i), NULL))
+                if (rb_hash_stlike_lookup(argv[j], elt, NULL))
                     break;
             }
             else {
@@ -5456,20 +5764,25 @@ rb_ary_difference_multi(int argc, VALUE *argv, VALUE ary)
 
 /*
  *  call-seq:
- *    array & other_array -> new_array
+ *    self & other_array -> new_array
  *
- *  Returns a new \Array containing each element found in both +array+ and \Array +other_array+;
- *  duplicates are omitted; items are compared using <tt>eql?</tt>
- *  (items must also implement +hash+ correctly):
+ *  Returns a new array containing the _intersection_ of +self+ and +other_array+;
+ *  that is, containing those elements found in both +self+ and +other_array+:
  *
  *    [0, 1, 2, 3] & [1, 2] # => [1, 2]
- *    [0, 1, 0, 1] & [0, 1] # => [0, 1]
  *
- *  Preserves order from +array+:
+ *  Omits duplicates:
+ *
+ *    [0, 1, 1, 0] & [0, 1] # => [0, 1]
+ *
+ *  Preserves order from +self+:
  *
  *    [0, 1, 2] & [3, 2, 1, 0] # => [0, 1, 2]
  *
- *  Related: Array#intersection.
+ *  Identifies common elements using method <tt>#eql?</tt>
+ *  (as defined in each element of +self+).
+ *
+ *  Related: see {Methods for Combining}[rdoc-ref:Array@Methods+for+Combining].
  */
 
 
@@ -5509,23 +5822,23 @@ rb_ary_and(VALUE ary1, VALUE ary2)
 
 /*
  *  call-seq:
- *    array.intersection(*other_arrays) -> new_array
+ *    intersection(*other_arrays) -> new_array
  *
- *  Returns a new \Array containing each element found both in +self+
- *  and in all of the given Arrays +other_arrays+;
- *  duplicates are omitted; items are compared using <tt>eql?</tt>
- *  (items must also implement +hash+ correctly):
+ *  Returns a new array containing each element in +self+ that is +#eql?+
+ *  to at least one element in each of the given +other_arrays+;
+ *  duplicates are omitted:
  *
- *    [0, 1, 2, 3].intersection([0, 1, 2], [0, 1, 3]) # => [0, 1]
  *    [0, 0, 1, 1, 2, 3].intersection([0, 1, 2], [0, 1, 3]) # => [0, 1]
  *
- *  Preserves order from +self+:
+ *  Each element must correctly implement method <tt>#hash</tt>.
+ *
+ *  Order from +self+ is preserved:
  *
  *    [0, 1, 2].intersection([2, 1, 0]) # => [0, 1, 2]
  *
- *  Returns a copy of +self+ if no arguments given.
+ *  Returns a copy of +self+ if no arguments are given.
  *
- *  Related: Array#&.
+ *  Related: see {Methods for Combining}[rdoc-ref:Array@Methods+for+Combining].
  */
 
 static VALUE
@@ -5574,17 +5887,17 @@ rb_ary_union_hash(VALUE hash, VALUE ary2)
 
 /*
  *  call-seq:
- *    array | other_array -> new_array
+ *    self | other_array -> new_array
  *
- *  Returns the union of +array+ and \Array +other_array+;
+ *  Returns the union of +self+ and +other_array+;
  *  duplicates are removed; order is preserved;
- *  items are compared using <tt>eql?</tt>:
+ *  items are compared using <tt>eql?</tt> and <tt>hash</tt>:
  *
  *    [0, 1] | [2, 3] # => [0, 1, 2, 3]
  *    [0, 1, 1] | [2, 2, 3] # => [0, 1, 2, 3]
  *    [0, 1, 2] | [3, 2, 1, 0] # => [0, 1, 2, 3]
  *
- *  Related: Array#union.
+ *  Related: see {Methods for Combining}[rdoc-ref:Array@Methods+for+Combining].
  */
 
 static VALUE
@@ -5608,18 +5921,25 @@ rb_ary_or(VALUE ary1, VALUE ary2)
 
 /*
  *  call-seq:
- *    array.union(*other_arrays) -> new_array
+ *    union(*other_arrays) -> new_array
  *
- *  Returns a new \Array that is the union of +self+ and all given Arrays +other_arrays+;
- *  duplicates are removed;  order is preserved;  items are compared using <tt>eql?</tt>:
+ *  Returns a new array that is the union of the elements of +self+
+ *  and all given arrays +other_arrays+;
+ *  items are compared using <tt>eql?</tt> and <tt>hash</tt>:
  *
  *    [0, 1, 2, 3].union([4, 5], [6, 7]) # => [0, 1, 2, 3, 4, 5, 6, 7]
+ *
+ *  Removes duplicates (preserving the first found):
+ *
  *    [0, 1, 1].union([2, 1], [3, 1]) # => [0, 1, 2, 3]
- *    [0, 1, 2, 3].union([3, 2], [1, 0]) # => [0, 1, 2, 3]
  *
- *  Returns a copy of +self+ if no arguments given.
+ *  Preserves order (preserving the position of the first found):
  *
- *  Related: Array#|.
+ *    [3, 2, 1, 0].union([5, 3], [4, 2]) # => [3, 2, 1, 0, 5, 4]
+ *
+ *  With no arguments given, returns a copy of +self+.
+ *
+ *  Related: see {Methods for Combining}[rdoc-ref:Array@Methods+for+Combining].
  */
 
 static VALUE
@@ -5652,19 +5972,16 @@ rb_ary_union_multi(int argc, VALUE *argv, VALUE ary)
 
 /*
  *  call-seq:
- *     ary.intersect?(other_ary)   -> true or false
+ *    intersect?(other_array) -> true or false
+ *
+ *  Returns whether +other_array+ has at least one element that is +#eql?+ to some element of +self+:
  *
- *  Returns +true+ if the array and +other_ary+ have at least one element in
- *  common, otherwise returns +false+:
+ *    [1, 2, 3].intersect?([3, 4, 5]) # => true
+ *    [1, 2, 3].intersect?([4, 5, 6]) # => false
  *
- *     a = [ 1, 2, 3 ]
- *     b = [ 3, 4, 5 ]
- *     c = [ 5, 6, 7 ]
- *     a.intersect?(b)   #=> true
- *     a.intersect?(c)   #=> false
+ *  Each element must correctly implement method <tt>#hash</tt>.
  *
- *  Array elements are compared using <tt>eql?</tt>
- *  (items must also implement +hash+ correctly).
+ *  Related: see {Methods for Querying}[rdoc-ref:Array@Methods+for+Querying].
  */
 
 static VALUE
@@ -5798,42 +6115,51 @@ ary_max_opt_string(VALUE ary, long i, VALUE vmax)
 
 /*
  *  call-seq:
- *    array.max -> element
- *    array.max {|a, b| ... } -> element
- *    array.max(n) -> new_array
- *    array.max(n) {|a, b| ... } -> new_array
+ *    max -> element
+ *    max(count) -> new_array
+ *    max {|a, b| ... } -> element
+ *    max(count) {|a, b| ... } -> new_array
  *
  *  Returns one of the following:
  *
  *  - The maximum-valued element from +self+.
- *  - A new \Array of maximum-valued elements selected from +self+.
+ *  - A new array of maximum-valued elements from +self+.
  *
- *  When no block is given, each element in +self+ must respond to method <tt><=></tt>
- *  with an Integer.
+ *  Does not modify +self+.
+ *
+ *  With no block given, each element in +self+ must respond to method <tt>#<=></tt>
+ *  with a numeric.
  *
  *  With no argument and no block, returns the element in +self+
- *  having the maximum value per method <tt><=></tt>:
+ *  having the maximum value per method <tt>#<=></tt>:
  *
- *    [0, 1, 2].max # => 2
+ *    [1, 0, 3, 2].max # => 3
  *
- *  With an argument Integer +n+ and no block, returns a new \Array with at most +n+ elements,
- *  in descending order per method <tt><=></tt>:
+ *  With non-negative numeric argument +count+ and no block,
+ *  returns a new array with at most +count+ elements,
+ *  in descending order, per method <tt>#<=></tt>:
  *
- *    [0, 1, 2, 3].max(3) # => [3, 2, 1]
- *    [0, 1, 2, 3].max(6) # => [3, 2, 1, 0]
+ *    [1, 0, 3, 2].max(3)   # => [3, 2, 1]
+ *    [1, 0, 3, 2].max(3.0) # => [3, 2, 1]
+ *    [1, 0, 3, 2].max(9)   # => [3, 2, 1, 0]
+ *    [1, 0, 3, 2].max(0)   # => []
  *
- *  When a block is given, the block must return an Integer.
+ *  With a block given, the block must return a numeric.
  *
- *  With a block and no argument, calls the block <tt>self.size-1</tt> times to compare elements;
+ *  With a block and no argument, calls the block <tt>self.size - 1</tt> times to compare elements;
  *  returns the element having the maximum value per the block:
  *
- *    ['0', '00', '000'].max {|a, b| a.size <=> b.size } # => "000"
+ *    ['0', '', '000', '00'].max {|a, b| a.size <=> b.size }
+ *    # => "000"
  *
- *  With an argument +n+ and a block, returns a new \Array with at most +n+ elements,
- *  in descending order per the block:
+ *  With non-negative numeric argument +count+ and a block,
+ *  returns a new array with at most +count+ elements,
+ *  in descending order, per the block:
  *
- *    ['0', '00', '000'].max(2) {|a, b| a.size <=> b.size } # => ["000", "00"]
+ *    ['0', '', '000', '00'].max(2) {|a, b| a.size <=> b.size }
+ *    # => ["000", "00"]
  *
+ *  Related: see {Methods for Fetching}[rdoc-ref:Array@Methods+for+Fetching].
  */
 static VALUE
 rb_ary_max(int argc, VALUE *argv, VALUE ary)
@@ -5966,42 +6292,51 @@ ary_min_opt_string(VALUE ary, long i, VALUE vmin)
 
 /*
  *  call-seq:
- *    array.min -> element
- *    array.min { |a, b| ... } -> element
- *    array.min(n) -> new_array
- *    array.min(n) { |a, b| ... } -> new_array
+ *    min -> element
+ *    min(count) -> new_array
+ *    min {|a, b| ... } -> element
+ *    min(count) {|a, b| ... } -> new_array
  *
  *  Returns one of the following:
  *
  *  - The minimum-valued element from +self+.
- *  - A new \Array of minimum-valued elements selected from +self+.
+ *  - A new array of minimum-valued elements from +self+.
+ *
+ *  Does not modify +self+.
  *
- *  When no block is given, each element in +self+ must respond to method <tt><=></tt>
- *  with an Integer.
+ *  With no block given, each element in +self+ must respond to method <tt>#<=></tt>
+ *  with a numeric.
  *
  *  With no argument and no block, returns the element in +self+
- *  having the minimum value per method <tt><=></tt>:
+ *  having the minimum value per method <tt>#<=></tt>:
  *
- *    [0, 1, 2].min # => 0
+ *    [1, 0, 3, 2].min # => 0
  *
- *  With Integer argument +n+ and no block, returns a new \Array with at most +n+ elements,
- *  in ascending order per method <tt><=></tt>:
+ *  With non-negative numeric argument +count+ and no block,
+ *  returns a new array with at most +count+ elements,
+ *  in ascending order, per method <tt>#<=></tt>:
  *
- *    [0, 1, 2, 3].min(3) # => [0, 1, 2]
- *    [0, 1, 2, 3].min(6) # => [0, 1, 2, 3]
+ *    [1, 0, 3, 2].min(3)   # => [0, 1, 2]
+ *    [1, 0, 3, 2].min(3.0) # => [0, 1, 2]
+ *    [1, 0, 3, 2].min(9)   # => [0, 1, 2, 3]
+ *    [1, 0, 3, 2].min(0)   # => []
  *
- *  When a block is given, the block must return an Integer.
+ *  With a block given, the block must return a numeric.
  *
- *  With a block and no argument, calls the block <tt>self.size-1</tt> times to compare elements;
+ *  With a block and no argument, calls the block <tt>self.size - 1</tt> times to compare elements;
  *  returns the element having the minimum value per the block:
  *
- *    ['0', '00', '000'].min { |a, b| a.size <=> b.size } # => "0"
+ *    ['0', '', '000', '00'].min {|a, b| a.size <=> b.size }
+ *    # => ""
  *
- *  With an argument +n+ and a block, returns a new \Array with at most +n+ elements,
- *  in ascending order per the block:
+ *  With non-negative numeric argument +count+ and a block,
+ *  returns a new array with at most +count+ elements,
+ *  in ascending order, per the block:
  *
- *    ['0', '00', '000'].min(2) {|a, b| a.size <=> b.size } # => ["0", "00"]
+ *    ['0', '', '000', '00'].min(2) {|a, b| a.size <=> b.size }
+ *    # => ["", "0"]
  *
+ *  Related: see {Methods for Fetching}[rdoc-ref:Array@Methods+for+Fetching].
  */
 static VALUE
 rb_ary_min(int argc, VALUE *argv, VALUE ary)
@@ -6045,26 +6380,25 @@ rb_ary_min(int argc, VALUE *argv, VALUE ary)
 
 /*
  *  call-seq:
- *    array.minmax -> [min_val, max_val]
- *    array.minmax {|a, b| ... } -> [min_val, max_val]
+ *    minmax -> array
+ *    minmax {|a, b| ... } -> array
  *
- *  Returns a new 2-element \Array containing the minimum and maximum values
- *  from +self+, either per method <tt><=></tt> or per a given block:.
+ *  Returns a 2-element array containing the minimum-valued and maximum-valued
+ *  elements from +self+;
+ *  does not modify +self+.
  *
- *  When no block is given, each element in +self+ must respond to method <tt><=></tt>
- *  with an Integer;
- *  returns a new 2-element \Array containing the minimum and maximum values
- *  from +self+, per method <tt><=></tt>:
+ *  With no block given, the minimum and maximum values are determined using method <tt>#<=></tt>:
  *
- *    [0, 1, 2].minmax # => [0, 2]
+ *    [1, 0, 3, 2].minmax # => [0, 3]
  *
- *  When a block is given, the block must return an Integer;
- *  the block is called <tt>self.size-1</tt> times to compare elements;
- *  returns a new 2-element \Array containing the minimum and maximum values
- *  from +self+, per the block:
+ *  With a block given, the block must return a numeric;
+ *  the block is called <tt>self.size - 1</tt> times to compare elements;
+ *  returns the elements having the minimum and maximum values per the block:
  *
- *    ['0', '00', '000'].minmax {|a, b| a.size <=> b.size } # => ["0", "000"]
+ *    ['0', '', '000', '00'].minmax {|a, b| a.size <=> b.size }
+ *    # => ["", "000"]
  *
+ *  Related: see {Methods for Fetching}[rdoc-ref:Array@Methods+for+Fetching].
  */
 static VALUE
 rb_ary_minmax(VALUE ary)
@@ -6084,32 +6418,30 @@ push_value(st_data_t key, st_data_t val, st_data_t ary)
 
 /*
  *  call-seq:
- *    array.uniq! -> self or nil
- *    array.uniq! {|element| ... } -> self or nil
+ *    uniq! -> self or nil
+ *    uniq! {|element| ... } -> self or nil
  *
  *  Removes duplicate elements from +self+, the first occurrence always being retained;
  *  returns +self+ if any elements removed, +nil+ otherwise.
  *
  *  With no block given, identifies and removes elements using method <tt>eql?</tt>
- *  to compare.
- *
- *  Returns +self+ if any elements removed:
+ *  and <tt>hash</tt> to compare elements:
  *
  *    a = [0, 0, 1, 1, 2, 2]
  *    a.uniq! # => [0, 1, 2]
- *
- *  Returns +nil+ if no elements removed.
+ *    a.uniq! # => nil
  *
  *  With a block given, calls the block for each element;
- *  identifies (using method <tt>eql?</tt>) and removes
- *  elements for which the block returns duplicate values.
- *
- *  Returns +self+ if any elements removed:
+ *  identifies and omits "duplicate" elements using method <tt>eql?</tt>
+ *  and <tt>hash</tt> to compare <i>block return values</i>;
+ *  that is, an element is a duplicate if its block return value
+ *  is the same as that of a previous element:
  *
  *    a = ['a', 'aa', 'aaa', 'b', 'bb', 'bbb']
- *    a.uniq! {|element| element.size } # => ['a', 'aa', 'aaa']
+ *    a.uniq! {|element| element.size } # => ["a", "aa", "aaa"]
+ *    a.uniq! {|element| element.size } # => nil
  *
- *  Returns +nil+ if no elements removed.
+ *  Related: see {Methods for Deleting}[rdoc-ref:Array@Methods+for+Deleting].
  */
 static VALUE
 rb_ary_uniq_bang(VALUE ary)
@@ -6131,7 +6463,7 @@ rb_ary_uniq_bang(VALUE ary)
     }
     rb_ary_modify_check(ary);
     ARY_SET_LEN(ary, 0);
-    if (ARY_SHARED_P(ary) && !ARY_EMBED_P(ary)) {
+    if (ARY_SHARED_P(ary)) {
         rb_ary_unshare(ary);
         FL_SET_EMBED(ary);
     }
@@ -6143,25 +6475,28 @@ rb_ary_uniq_bang(VALUE ary)
 
 /*
  *  call-seq:
- *    array.uniq -> new_array
- *    array.uniq {|element| ... } -> new_array
+ *    uniq -> new_array
+ *    uniq {|element| ... } -> new_array
  *
- *  Returns a new \Array containing those elements from +self+ that are not duplicates,
+ *  Returns a new array containing those elements from +self+ that are not duplicates,
  *  the first occurrence always being retained.
  *
- *  With no block given, identifies and omits duplicates using method <tt>eql?</tt>
- *  to compare:
+ *  With no block given, identifies and omits duplicate elements using method <tt>eql?</tt>
+ *  and <tt>hash</tt> to compare elements:
  *
  *    a = [0, 0, 1, 1, 2, 2]
  *    a.uniq # => [0, 1, 2]
  *
  *  With a block given, calls the block for each element;
- *  identifies (using method <tt>eql?</tt>) and omits duplicate values,
- *  that is, those elements for which the block returns the same value:
+ *  identifies and omits "duplicate" elements using method <tt>eql?</tt>
+ *  and <tt>hash</tt> to compare <i>block return values</i>;
+ *  that is, an element is a duplicate if its block return value
+ *  is the same as that of a previous element:
  *
  *    a = ['a', 'aa', 'aaa', 'b', 'bb', 'bbb']
  *    a.uniq {|element| element.size } # => ["a", "aa", "aaa"]
  *
+ *  Related: {Methods for Fetching}[rdoc-ref:Array@Methods+for+Fetching].
  */
 
 static VALUE
@@ -6187,14 +6522,21 @@ rb_ary_uniq(VALUE ary)
 
 /*
  *  call-seq:
- *    array.compact! -> self or nil
+ *    compact! -> self or nil
  *
- *  Removes all +nil+ elements from +self+.
+ *  Removes all +nil+ elements from +self+;
+ *  Returns +self+ if any elements are removed, +nil+ otherwise:
  *
- *  Returns +self+ if any elements removed, otherwise +nil+.
+ *    a = [nil, 0, nil, false, nil, '', nil, [], nil, {}]
+ *    a.compact! # => [0, false, "", [], {}]
+ *    a          # => [0, false, "", [], {}]
+ *    a.compact! # => nil
+ *
+ *  Related: Array#compact;
+ *  see also {Methods for Deleting}[rdoc-ref:Array@Methods+for+Deleting].
  */
 
-static VALUE
+VALUE
 rb_ary_compact_bang(VALUE ary)
 {
     VALUE *p, *t, *end;
@@ -6219,12 +6561,16 @@ rb_ary_compact_bang(VALUE ary)
 
 /*
  *  call-seq:
- *    array.compact -> new_array
+ *    compact -> new_array
  *
- *  Returns a new \Array containing all non-+nil+ elements from +self+:
+ *  Returns a new array containing only the non-+nil+ elements from +self+;
+ *  element order is preserved:
  *
- *    a = [nil, 0, nil, 1, nil, 2, nil]
- *    a.compact # => [0, 1, 2]
+ *    a = [nil, 0, nil, false, nil, '', nil, [], nil, {}]
+ *    a.compact # => [0, false, "", [], {}]
+ *
+ *  Related: Array#compact!;
+ *  see also {Methods for Deleting}[rdoc-ref:Array@Methods+for+Deleting].
  */
 
 static VALUE
@@ -6237,29 +6583,29 @@ rb_ary_compact(VALUE ary)
 
 /*
  *  call-seq:
- *    array.count -> an_integer
- *    array.count(obj) -> an_integer
- *    array.count {|element| ... } -> an_integer
+ *    count -> integer
+ *    count(object) -> integer
+ *    count {|element| ... } -> integer
  *
  *  Returns a count of specified elements.
  *
  *  With no argument and no block, returns the count of all elements:
  *
- *    [0, 1, 2].count # => 3
- *    [].count # => 0
+ *    [0, :one, 'two', 3, 3.0].count # => 5
  *
- *  With argument +obj+, returns the count of elements <tt>==</tt> to +obj+:
+ *  With argument +object+ given, returns the count of elements <tt>==</tt> to +object+:
  *
- *    [0, 1, 2, 0.0].count(0) # => 2
- *    [0, 1, 2].count(3) # => 0
+ *    [0, :one, 'two', 3, 3.0].count(3) # => 2
  *
  *  With no argument and a block given, calls the block with each element;
  *  returns the count of elements for which the block returns a truthy value:
  *
- *    [0, 1, 2, 3].count {|element| element > 1} # => 2
+ *    [0, 1, 2, 3].count {|element| element > 1 } # => 2
+ *
+ *  With argument +object+ and a block given, issues a warning, ignores the block,
+ *  and returns the count of elements <tt>==</tt> to +object+.
  *
- *  With argument +obj+ and a block given, issues a warning, ignores the block,
- *  and returns the count of elements <tt>==</tt> to +obj+.
+ *  Related: see {Methods for Querying}[rdoc-ref:Array@Methods+for+Querying].
  */
 
 static VALUE
@@ -6295,16 +6641,9 @@ rb_ary_count(int argc, VALUE *argv, VALUE ary)
 static VALUE
 flatten(VALUE ary, int level)
 {
-    static const rb_data_type_t flatten_memo_data_type = {
-        .wrap_struct_name = "array_flatten_memo_data_type",
-        .function = { NULL, (RUBY_DATA_FUNC)st_free_table },
-        NULL, NULL, RUBY_TYPED_FREE_IMMEDIATELY | RUBY_TYPED_WB_PROTECTED
-    };
-
     long i;
-    VALUE stack, result, tmp = 0, elt, vmemo;
-    st_table *memo = 0;
-    st_data_t id;
+    VALUE stack, result, tmp = 0, elt;
+    VALUE memo = Qfalse;
 
     for (i = 0; i < RARRAY_LEN(ary); i++) {
         elt = RARRAY_AREF(ary, i);
@@ -6326,10 +6665,9 @@ flatten(VALUE ary, int level)
     rb_ary_push(stack, LONG2NUM(i + 1));
 
     if (level < 0) {
-        memo = st_init_numtable();
-        vmemo = TypedData_Wrap_Struct(0, &flatten_memo_data_type, memo);
-        st_insert(memo, (st_data_t)ary, (st_data_t)Qtrue);
-        st_insert(memo, (st_data_t)tmp, (st_data_t)Qtrue);
+        memo = rb_obj_hide(rb_ident_hash_new());
+        rb_hash_aset(memo, ary, Qtrue);
+        rb_hash_aset(memo, tmp, Qtrue);
     }
 
     ary = tmp;
@@ -6344,9 +6682,8 @@ flatten(VALUE ary, int level)
             }
             tmp = rb_check_array_type(elt);
             if (RBASIC(result)->klass) {
-                if (memo) {
-                    RB_GC_GUARD(vmemo);
-                    st_clear(memo);
+                if (RTEST(memo)) {
+                    rb_hash_clear(memo);
                 }
                 rb_raise(rb_eRuntimeError, "flatten reentered");
             }
@@ -6355,12 +6692,11 @@ flatten(VALUE ary, int level)
             }
             else {
                 if (memo) {
-                    id = (st_data_t)tmp;
-                    if (st_is_member(memo, id)) {
-                        st_clear(memo);
+                    if (rb_hash_aref(memo, tmp) == Qtrue) {
+                        rb_hash_clear(memo);
                         rb_raise(rb_eArgError, "tried to flatten recursive array");
                     }
-                    st_insert(memo, id, (st_data_t)Qtrue);
+                    rb_hash_aset(memo, tmp, Qtrue);
                 }
                 rb_ary_push(stack, ary);
                 rb_ary_push(stack, LONG2NUM(i));
@@ -6372,8 +6708,7 @@ flatten(VALUE ary, int level)
             break;
         }
         if (memo) {
-            id = (st_data_t)ary;
-            st_delete(memo, &id, 0);
+            rb_hash_delete(memo, ary);
         }
         tmp = rb_ary_pop(stack);
         i = NUM2LONG(tmp);
@@ -6381,7 +6716,7 @@ flatten(VALUE ary, int level)
     }
 
     if (memo) {
-        st_clear(memo);
+        rb_hash_clear(memo);
     }
 
     RBASIC_SET_CLASS(result, rb_cArray);
@@ -6390,33 +6725,37 @@ flatten(VALUE ary, int level)
 
 /*
  *  call-seq:
- *    array.flatten! -> self or nil
- *    array.flatten!(level) -> self or nil
+ *    flatten!(depth = nil) -> self or nil
+ *
+ *  Returns +self+ as a recursively flattening of +self+ to +depth+ levels of recursion;
+ *  +depth+ must be an
+ *  {integer-convertible object}[rdoc-ref:implicit_conversion.rdoc@Integer-Convertible+Objects],
+ *  or +nil+.
+ *  At each level of recursion:
  *
- *  Replaces each nested \Array in +self+ with the elements from that \Array;
- *  returns +self+ if any changes, +nil+ otherwise.
+ *  - Each element that is an array is "flattened"
+ *    (that is, replaced by its individual array elements).
+ *  - Each element that is not an array is unchanged
+ *    (even if the element is an object that has instance method +flatten+).
  *
- *  With non-negative Integer argument +level+, flattens recursively through +level+ levels:
+ *  Returns +nil+ if no elements were flattened.
  *
- *    a = [ 0, [ 1, [2, 3], 4 ], 5 ]
- *    a.flatten!(1) # => [0, 1, [2, 3], 4, 5]
- *    a = [ 0, [ 1, [2, 3], 4 ], 5 ]
- *    a.flatten!(2) # => [0, 1, 2, 3, 4, 5]
- *    a = [ 0, [ 1, [2, 3], 4 ], 5 ]
- *    a.flatten!(3) # => [0, 1, 2, 3, 4, 5]
- *    [0, 1, 2].flatten!(1) # => nil
+ *  With non-negative integer argument +depth+, flattens recursively through +depth+ levels:
  *
- *  With no argument, a +nil+ argument, or with negative argument +level+, flattens all levels:
+ *    a = [ 0, [ 1, [2, 3], 4 ], 5, {foo: 0}, Set.new([6, 7]) ]
+ *    a                   # => [0, [1, [2, 3], 4], 5, {foo: 0}, #<Set: {6, 7}>]
+ *    a.dup.flatten!(1)   # => [0, 1, [2, 3], 4, 5, {foo: 0}, #<Set: {6, 7}>]
+ *    a.dup.flatten!(1.1) # => [0, 1, [2, 3], 4, 5, {foo: 0}, #<Set: {6, 7}>]
+ *    a.dup.flatten!(2)   # => [0, 1, 2, 3, 4, 5, {foo: 0}, #<Set: {6, 7}>]
+ *    a.dup.flatten!(3)   # => [0, 1, 2, 3, 4, 5, {foo: 0}, #<Set: {6, 7}>]
  *
- *    a = [ 0, [ 1, [2, 3], 4 ], 5 ]
- *    a.flatten! # => [0, 1, 2, 3, 4, 5]
- *    [0, 1, 2].flatten! # => nil
- *    a = [ 0, [ 1, [2, 3], 4 ], 5 ]
- *    a.flatten!(-1) # => [0, 1, 2, 3, 4, 5]
- *    a = [ 0, [ 1, [2, 3], 4 ], 5 ]
- *    a.flatten!(-2) # => [0, 1, 2, 3, 4, 5]
- *    [0, 1, 2].flatten!(-1) # => nil
+ *  With +nil+ or negative argument +depth+, flattens all levels:
  *
+ *    a.dup.flatten!     # => [0, 1, 2, 3, 4, 5, {foo: 0}, #<Set: {6, 7}>]
+ *    a.dup.flatten!(-1) # => [0, 1, 2, 3, 4, 5, {foo: 0}, #<Set: {6, 7}>]
+ *
+ *  Related: Array#flatten;
+ *  see also {Methods for Assigning}[rdoc-ref:Array@Methods+for+Assigning].
  */
 
 static VALUE
@@ -6434,7 +6773,7 @@ rb_ary_flatten_bang(int argc, VALUE *argv, VALUE ary)
     if (result == ary) {
         return Qnil;
     }
-    if (!(mod = ARY_EMBED_P(result))) rb_obj_freeze(result);
+    if (!(mod = ARY_EMBED_P(result))) rb_ary_freeze(result);
     rb_ary_replace(ary, result);
     if (mod) ARY_SET_EMBED_LEN(result, 0);
 
@@ -6443,35 +6782,37 @@ rb_ary_flatten_bang(int argc, VALUE *argv, VALUE ary)
 
 /*
  *  call-seq:
- *    array.flatten -> new_array
- *    array.flatten(level) -> new_array
- *
- *  Returns a new \Array that is a recursive flattening of +self+:
- *  - Each non-Array element is unchanged.
- *  - Each \Array is replaced by its individual elements.
- *
- *  With non-negative Integer argument +level+, flattens recursively through +level+ levels:
- *
- *    a = [ 0, [ 1, [2, 3], 4 ], 5 ]
- *    a.flatten(0) # => [0, [1, [2, 3], 4], 5]
- *    a = [ 0, [ 1, [2, 3], 4 ], 5 ]
- *    a.flatten(1) # => [0, 1, [2, 3], 4, 5]
- *    a = [ 0, [ 1, [2, 3], 4 ], 5 ]
- *    a.flatten(2) # => [0, 1, 2, 3, 4, 5]
- *    a = [ 0, [ 1, [2, 3], 4 ], 5 ]
- *    a.flatten(3) # => [0, 1, 2, 3, 4, 5]
- *
- *  With no argument, a +nil+ argument, or with negative argument +level+, flattens all levels:
- *
- *    a = [ 0, [ 1, [2, 3], 4 ], 5 ]
- *    a.flatten # => [0, 1, 2, 3, 4, 5]
- *    [0, 1, 2].flatten # => [0, 1, 2]
- *    a = [ 0, [ 1, [2, 3], 4 ], 5 ]
- *    a.flatten(-1) # => [0, 1, 2, 3, 4, 5]
- *    a = [ 0, [ 1, [2, 3], 4 ], 5 ]
- *    a.flatten(-2) # => [0, 1, 2, 3, 4, 5]
- *    [0, 1, 2].flatten(-1) # => [0, 1, 2]
+ *    flatten(depth = nil) -> new_array
+ *
+ *  Returns a new array that is a recursive flattening of +self+
+ *  to +depth+ levels of recursion;
+ *  +depth+ must be an
+ *  {integer-convertible object}[rdoc-ref:implicit_conversion.rdoc@Integer-Convertible+Objects]
+ *  or +nil+.
+ *  At each level of recursion:
+ *
+ *  - Each element that is an array is "flattened"
+ *    (that is, replaced by its individual array elements).
+ *  - Each element that is not an array is unchanged
+ *    (even if the element is an object that has instance method +flatten+).
+ *
+ *  With non-negative integer argument +depth+, flattens recursively through +depth+ levels:
+ *
+ *    a = [ 0, [ 1, [2, 3], 4 ], 5, {foo: 0}, Set.new([6, 7]) ]
+ *    a              # => [0, [1, [2, 3], 4], 5, {foo: 0}, #<Set: {6, 7}>]
+ *    a.flatten(0)   # => [0, [1, [2, 3], 4], 5, {foo: 0}, #<Set: {6, 7}>]
+ *    a.flatten(1  ) # => [0, 1, [2, 3], 4, 5, {foo: 0}, #<Set: {6, 7}>]
+ *    a.flatten(1.1) # => [0, 1, [2, 3], 4, 5, {foo: 0}, #<Set: {6, 7}>]
+ *    a.flatten(2)   # => [0, 1, 2, 3, 4, 5, {foo: 0}, #<Set: {6, 7}>]
+ *    a.flatten(3)   # => [0, 1, 2, 3, 4, 5, {foo: 0}, #<Set: {6, 7}>]
+ *
+ *  With +nil+ or negative +depth+, flattens all levels.
  *
+ *    a.flatten     # => [0, 1, 2, 3, 4, 5, {foo: 0}, #<Set: {6, 7}>]
+ *    a.flatten(-1) # => [0, 1, 2, 3, 4, 5, {foo: 0}, #<Set: {6, 7}>]
+ *
+ *  Related: Array#flatten!;
+ *  see also {Methods for Converting}[rdoc-ref:Array@Methods+for+Converting].
  */
 
 static VALUE
@@ -6503,7 +6844,7 @@ rb_ary_shuffle_bang(rb_execution_context_t *ec, VALUE ary, VALUE randgen)
     rb_ary_modify(ary);
     i = len = RARRAY_LEN(ary);
     RARRAY_PTR_USE(ary, ptr, {
-        while (i) {
+        while (i > 1) {
             long j = RAND_UPTO(i);
             VALUE tmp;
             if (len != RARRAY_LEN(ary) || ptr != RARRAY_CONST_PTR(ary)) {
@@ -6525,6 +6866,14 @@ rb_ary_shuffle(rb_execution_context_t *ec, VALUE ary, VALUE randgen)
     return ary;
 }
 
+static const rb_data_type_t ary_sample_memo_type = {
+    .wrap_struct_name = "ary_sample_memo",
+    .function = {
+        .dfree = (RUBY_DATA_FUNC)st_free_table,
+    },
+    .flags = RUBY_TYPED_WB_PROTECTED | RUBY_TYPED_FREE_IMMEDIATELY
+};
+
 static VALUE
 ary_sample(rb_execution_context_t *ec, VALUE ary, VALUE randgen, VALUE nv, VALUE to_array)
 {
@@ -6606,11 +6955,9 @@ ary_sample(rb_execution_context_t *ec, VALUE ary, VALUE randgen, VALUE nv, VALUE
     }
     else if (n <= memo_threshold / 2) {
         long max_idx = 0;
-#undef RUBY_UNTYPED_DATA_WARNING
-#define RUBY_UNTYPED_DATA_WARNING 0
-        VALUE vmemo = Data_Wrap_Struct(0, 0, st_free_table, 0);
+        VALUE vmemo = TypedData_Wrap_Struct(0, &ary_sample_memo_type, 0);
         st_table *memo = st_init_numtable_with_size(n);
-        DATA_PTR(vmemo) = memo;
+        RTYPEDDATA_DATA(vmemo) = memo;
         result = rb_ary_new_capa(n);
         RARRAY_PTR_USE(result, ptr_result, {
             for (i=0; i<n; i++) {
@@ -6633,8 +6980,9 @@ ary_sample(rb_execution_context_t *ec, VALUE ary, VALUE randgen, VALUE nv, VALUE
                 }
             });
         });
-        DATA_PTR(vmemo) = 0;
+        RTYPEDDATA_DATA(vmemo) = 0;
         st_free_table(memo);
+        RB_GC_GUARD(vmemo);
     }
     else {
         result = rb_ary_dup(ary);
@@ -6656,6 +7004,12 @@ ary_sample(rb_execution_context_t *ec, VALUE ary, VALUE randgen, VALUE nv, VALUE
 }
 
 static VALUE
+ary_sized_alloc(rb_execution_context_t *ec, VALUE self)
+{
+    return rb_ary_new2(RARRAY_LEN(self));
+}
+
+static VALUE
 ary_sample0(rb_execution_context_t *ec, VALUE ary)
 {
     return ary_sample(ec, ary, rb_cRandom, Qfalse, Qfalse);
@@ -6679,36 +7033,36 @@ rb_ary_cycle_size(VALUE self, VALUE args, VALUE eobj)
 
 /*
  *  call-seq:
- *    array.cycle {|element| ... } -> nil
- *    array.cycle(count) {|element| ... } -> nil
- *    array.cycle -> new_enumerator
- *    array.cycle(count) -> new_enumerator
+ *    cycle(count = nil) {|element| ... } -> nil
+ *    cycle(count = nil) -> new_enumerator
+ *
+ *  With a block given, may call the block, depending on the value of argument +count+;
+ *  +count+ must be an
+ *  {integer-convertible object}[rdoc-ref:implicit_conversion.rdoc@Integer-Convertible+Objects],
+ *  or +nil+.
  *
- *  When called with positive Integer argument +count+ and a block,
- *  calls the block with each element, then does so again,
+ *  When +count+ is positive,
+ *  calls the block with each element, then does so repeatedly,
  *  until it has done so +count+ times; returns +nil+:
  *
  *    output = []
  *    [0, 1].cycle(2) {|element| output.push(element) } # => nil
  *    output # => [0, 1, 0, 1]
  *
- *  If +count+ is zero or negative, does not call the block:
+ *  When +count+ is zero or negative, does not call the block:
  *
- *    [0, 1].cycle(0) {|element| fail 'Cannot happen' } # => nil
+ *    [0, 1].cycle(0) {|element| fail 'Cannot happen' }  # => nil
  *    [0, 1].cycle(-1) {|element| fail 'Cannot happen' } # => nil
  *
- *  When a block is given, and argument is omitted or +nil+, cycles forever:
+ *  When +count+ is +nil+, cycles forever:
  *
  *    # Prints 0 and 1 forever.
  *    [0, 1].cycle {|element| puts element }
  *    [0, 1].cycle(nil) {|element| puts element }
  *
- *  When no block is given, returns a new Enumerator:
- *
- *    [0, 1].cycle(2) # => #<Enumerator: [0, 1]:cycle(2)>
- *    [0, 1].cycle # => # => #<Enumerator: [0, 1]:cycle>
- *    [0, 1].cycle.first(5) # => [0, 1, 0, 1, 0]
+ *  With no block given, returns a new Enumerator.
  *
+ *  Related: see {Methods for Iterating}[rdoc-ref:Array@Methods+for+Iterating].
  */
 static VALUE
 rb_ary_cycle(int argc, VALUE *argv, VALUE ary)
@@ -6852,82 +7206,44 @@ rb_ary_permutation_size(VALUE ary, VALUE args, VALUE eobj)
 
 /*
  *  call-seq:
- *    array.permutation {|element| ... } -> self
- *    array.permutation(n) {|element| ... } -> self
- *    array.permutation -> new_enumerator
- *    array.permutation(n) -> new_enumerator
- *
- *  When invoked with a block, yield all permutations of elements of +self+; returns +self+.
- *  The order of permutations is indeterminate.
+ *    permutation(count = self.size) {|permutation| ... } -> self
+ *    permutation(count = self.size) -> new_enumerator
  *
- *  When a block and an in-range positive Integer argument +n+ (<tt>0 < n <= self.size</tt>)
- *  are given, calls the block with all +n+-tuple permutations of +self+.
+ *  Iterates over permutations of the elements of +self+;
+ *  the order of permutations is indeterminate.
  *
- *  Example:
- *
- *    a = [0, 1, 2]
- *    a.permutation(2) {|permutation| p permutation }
- *
- *  Output:
- *
- *    [0, 1]
- *    [0, 2]
- *    [1, 0]
- *    [1, 2]
- *    [2, 0]
- *    [2, 1]
- *
- *  Another example:
+ *  With a block and an in-range positive integer argument +count+ (<tt>0 < count <= self.size</tt>) given,
+ *  calls the block with each permutation of +self+ of size +count+;
+ *  returns +self+:
  *
  *    a = [0, 1, 2]
- *    a.permutation(3) {|permutation| p permutation }
+ *    perms = []
+ *    a.permutation(1) {|perm| perms.push(perm) }
+ *    perms # => [[0], [1], [2]]
  *
- *  Output:
+ *    perms = []
+ *    a.permutation(2) {|perm| perms.push(perm) }
+ *    perms # => [[0, 1], [0, 2], [1, 0], [1, 2], [2, 0], [2, 1]]
  *
- *    [0, 1, 2]
- *    [0, 2, 1]
- *    [1, 0, 2]
- *    [1, 2, 0]
- *    [2, 0, 1]
- *    [2, 1, 0]
+ *    perms = []
+ *    a.permutation(3) {|perm| perms.push(perm) }
+ *    perms # => [[0, 1, 2], [0, 2, 1], [1, 0, 2], [1, 2, 0], [2, 0, 1], [2, 1, 0]]
  *
- *  When +n+ is zero, calls the block once with a new empty \Array:
+ *  When +count+ is zero, calls the block once with a new empty array:
  *
- *    a = [0, 1, 2]
- *    a.permutation(0) {|permutation| p permutation }
+ *    perms = []
+ *    a.permutation(0) {|perm| perms.push(perm) }
+ *    perms # => [[]]
  *
- *  Output:
- *
- *    []
- *
- *  When +n+ is out of range (negative or larger than <tt>self.size</tt>),
+ *  When +count+ is out of range (negative or larger than <tt>self.size</tt>),
  *  does not call the block:
  *
- *    a = [0, 1, 2]
  *    a.permutation(-1) {|permutation| fail 'Cannot happen' }
  *    a.permutation(4) {|permutation| fail 'Cannot happen' }
  *
- *  When a block given but no argument,
- *  behaves the same as <tt>a.permutation(a.size)</tt>:
- *
- *    a = [0, 1, 2]
- *    a.permutation {|permutation| p permutation }
- *
- *  Output:
- *
- *    [0, 1, 2]
- *    [0, 2, 1]
- *    [1, 0, 2]
- *    [1, 2, 0]
- *    [2, 0, 1]
- *    [2, 1, 0]
- *
- *  Returns a new Enumerator if no block given:
- *
- *    a = [0, 1, 2]
- *    a.permutation # => #<Enumerator: [0, 1, 2]:permutation>
- *    a.permutation(2) # => #<Enumerator: [0, 1, 2]:permutation(2)>
+ *  With no block given, returns a new Enumerator.
  *
+ *  Related: {Methods for Iterating}[rdoc-ref:Array@Methods+for+Iterating].
  */
 
 static VALUE
@@ -7000,56 +7316,46 @@ rb_ary_combination_size(VALUE ary, VALUE args, VALUE eobj)
 
 /*
  *  call-seq:
- *    array.combination(n) {|element| ... } -> self
- *    array.combination(n) -> new_enumerator
- *
- *  Calls the block, if given, with combinations of elements of +self+;
- *  returns +self+. The order of combinations is indeterminate.
- *
- *  When a block and an in-range positive Integer argument +n+ (<tt>0 < n <= self.size</tt>)
- *  are given, calls the block with all +n+-tuple combinations of +self+.
+ *    combination(count) {|element| ... } -> self
+ *    combination(count) -> new_enumerator
  *
- *  Example:
+ *  When a block and a positive
+ *  {integer-convertible object}[rdoc-ref:implicit_conversion.rdoc@Integer-Convertible+Objects]
+ *  argument +count+ (<tt>0 < count <= self.size</tt>)
+ *  are given, calls the block with each combination of +self+ of size +count+;
+ *  returns +self+:
  *
- *    a = [0, 1, 2]
- *    a.combination(2) {|combination| p combination }
+ *    a = %w[a b c]                                   # => ["a", "b", "c"]
+ *    a.combination(2) {|combination| p combination } # => ["a", "b", "c"]
  *
  *  Output:
  *
- *    [0, 1]
- *    [0, 2]
- *    [1, 2]
+ *    ["a", "b"]
+ *    ["a", "c"]
+ *    ["b", "c"]
  *
- *  Another example:
+ *  The order of the yielded combinations is not guaranteed.
  *
- *    a = [0, 1, 2]
- *    a.combination(3) {|combination| p combination }
+ *  When +count+ is zero, calls the block once with a new empty array:
  *
- *  Output:
- *
- *    [0, 1, 2]
- *
- *  When +n+ is zero, calls the block once with a new empty \Array:
- *
- *    a = [0, 1, 2]
- *    a1 = a.combination(0) {|combination| p combination }
+ *    a.combination(0) {|combination| p combination }
+ *    [].combination(0) {|combination| p combination }
  *
  *  Output:
  *
  *    []
+ *    []
  *
- *  When +n+ is out of range (negative or larger than <tt>self.size</tt>),
+ *  When +count+ is negative or larger than +self.size+ and +self+ is non-empty,
  *  does not call the block:
  *
- *    a = [0, 1, 2]
- *    a.combination(-1) {|combination| fail 'Cannot happen' }
- *    a.combination(4) {|combination| fail 'Cannot happen' }
+ *    a.combination(-1) {|combination| fail 'Cannot happen' } # => ["a", "b", "c"]
+ *    a.combination(4)  {|combination| fail 'Cannot happen' } # => ["a", "b", "c"]
  *
- *  Returns a new Enumerator if no block given:
- *
- *    a = [0, 1, 2]
- *    a.combination(2) # => #<Enumerator: [0, 1, 2]:combination(2)>
+ *  With no block given, returns a new Enumerator.
  *
+ *  Related: Array#permutation;
+ *  see also {Methods for Iterating}[rdoc-ref:Array@Methods+for+Iterating].
  */
 
 static VALUE
@@ -7136,68 +7442,41 @@ rb_ary_repeated_permutation_size(VALUE ary, VALUE args, VALUE eobj)
 
 /*
  *  call-seq:
- *    array.repeated_permutation(n) {|permutation| ... } -> self
- *    array.repeated_permutation(n) -> new_enumerator
+ *    repeated_permutation(size) {|permutation| ... } -> self
+ *    repeated_permutation(size) -> new_enumerator
  *
- *  Calls the block with each repeated permutation of length +n+ of the elements of +self+;
- *  each permutation is an \Array;
+ *  With a block given, calls the block with each repeated permutation of length +size+
+ *  of the elements of +self+;
+ *  each permutation is an array;
  *  returns +self+. The order of the permutations is indeterminate.
  *
- *  When a block and a positive Integer argument +n+ are given, calls the block with each
- *  +n+-tuple repeated permutation of the elements of +self+.
- *  The number of permutations is <tt>self.size**n</tt>.
- *
- *  +n+ = 1:
+ *  If a positive integer argument +size+ is given,
+ *  calls the block with each +size+-tuple repeated permutation of the elements of +self+.
+ *  The number of permutations is <tt>self.size**size</tt>.
  *
- *    a = [0, 1, 2]
- *    a.repeated_permutation(1) {|permutation| p permutation }
- *
- *  Output:
- *
- *    [0]
- *    [1]
- *    [2]
- *
- *  +n+ = 2:
- *
- *    a.repeated_permutation(2) {|permutation| p permutation }
- *
- *  Output:
+ *  Examples:
  *
- *    [0, 0]
- *    [0, 1]
- *    [0, 2]
- *    [1, 0]
- *    [1, 1]
- *    [1, 2]
- *    [2, 0]
- *    [2, 1]
- *    [2, 2]
+ *  - +size+ is 1:
  *
- *  If +n+ is zero, calls the block once with an empty \Array.
+ *      p = []
+ *      [0, 1, 2].repeated_permutation(1) {|permutation| p.push(permutation) }
+ *      p # => [[0], [1], [2]]
  *
- *  If +n+ is negative, does not call the block:
+ *  - +size+ is 2:
  *
- *    a.repeated_permutation(-1) {|permutation| fail 'Cannot happen' }
+ *      p = []
+ *      [0, 1, 2].repeated_permutation(2) {|permutation| p.push(permutation) }
+ *      p # => [[0, 0], [0, 1], [0, 2], [1, 0], [1, 1], [1, 2], [2, 0], [2, 1], [2, 2]]
  *
- *  Returns a new Enumerator if no block given:
+ *  If +size+ is zero, calls the block once with an empty array.
  *
- *    a = [0, 1, 2]
- *    a.repeated_permutation(2) # => #<Enumerator: [0, 1, 2]:permutation(2)>
+ *  If +size+ is negative, does not call the block:
  *
- *  Using Enumerators, it's convenient to show the permutations and counts
- *  for some values of +n+:
+ *    [0, 1, 2].repeated_permutation(-1) {|permutation| fail 'Cannot happen' }
  *
- *    e = a.repeated_permutation(0)
- *    e.size # => 1
- *    e.to_a # => [[]]
- *    e = a.repeated_permutation(1)
- *    e.size # => 3
- *    e.to_a # => [[0], [1], [2]]
- *    e = a.repeated_permutation(2)
- *    e.size # => 9
- *    e.to_a # => [[0, 0], [0, 1], [0, 2], [1, 0], [1, 1], [1, 2], [2, 0], [2, 1], [2, 2]]
+ *  With no block given, returns a new Enumerator.
  *
+ *  Related: see {Methods for Combining}[rdoc-ref:Array@Methods+for+Combining].
  */
 static VALUE
 rb_ary_repeated_permutation(VALUE ary, VALUE num)
@@ -7268,65 +7547,41 @@ rb_ary_repeated_combination_size(VALUE ary, VALUE args, VALUE eobj)
 
 /*
  *  call-seq:
- *    array.repeated_combination(n) {|combination| ... } -> self
- *    array.repeated_combination(n) -> new_enumerator
+ *    repeated_combination(size) {|combination| ... } -> self
+ *    repeated_combination(size) -> new_enumerator
  *
- *  Calls the block with each repeated combination of length +n+ of the elements of +self+;
- *  each combination is an \Array;
+ *  With a block given, calls the block with each repeated combination of length +size+
+ *  of the elements of +self+;
+ *  each combination is an array;
  *  returns +self+. The order of the combinations is indeterminate.
  *
- *  When a block and a positive Integer argument +n+ are given, calls the block with each
- *  +n+-tuple repeated combination of the elements of +self+.
- *  The number of combinations is <tt>(n+1)(n+2)/2</tt>.
- *
- *  +n+ = 1:
- *
- *    a = [0, 1, 2]
- *    a.repeated_combination(1) {|combination| p combination }
- *
- *  Output:
- *
- *    [0]
- *    [1]
- *    [2]
- *
- *  +n+ = 2:
+ *  If a positive integer argument +size+ is given,
+ *  calls the block with each +size+-tuple repeated combination of the elements of +self+.
+ *  The number of combinations is <tt>(size+1)(size+2)/2</tt>.
  *
- *    a.repeated_combination(2) {|combination| p combination }
- *
- *  Output:
+ *  Examples:
  *
- *    [0, 0]
- *    [0, 1]
- *    [0, 2]
- *    [1, 1]
- *    [1, 2]
- *    [2, 2]
+ *  - +size+ is 1:
  *
- *  If +n+ is zero, calls the block once with an empty \Array.
+ *      c = []
+ *      [0, 1, 2].repeated_combination(1) {|combination| c.push(combination) }
+ *      c # => [[0], [1], [2]]
  *
- *  If +n+ is negative, does not call the block:
+ *  - +size+ is 2:
  *
- *    a.repeated_combination(-1) {|combination| fail 'Cannot happen' }
+ *      c = []
+ *      [0, 1, 2].repeated_combination(2) {|combination| c.push(combination) }
+ *      c # => [[0, 0], [0, 1], [0, 2], [1, 1], [1, 2], [2, 2]]
  *
- *  Returns a new Enumerator if no block given:
+ *  If +size+ is zero, calls the block once with an empty array.
  *
- *    a = [0, 1, 2]
- *    a.repeated_combination(2) # => #<Enumerator: [0, 1, 2]:combination(2)>
+ *  If +size+ is negative, does not call the block:
  *
- *  Using Enumerators, it's convenient to show the combinations and counts
- *  for some values of +n+:
+ *    [0, 1, 2].repeated_combination(-1) {|combination| fail 'Cannot happen' }
  *
- *    e = a.repeated_combination(0)
- *    e.size # => 1
- *    e.to_a # => [[]]
- *    e = a.repeated_combination(1)
- *    e.size # => 3
- *    e.to_a # => [[0], [1], [2]]
- *    e = a.repeated_combination(2)
- *    e.size # => 6
- *    e.to_a # => [[0, 0], [0, 1], [0, 2], [1, 1], [1, 2], [2, 2]]
+ *  With no block given, returns a new Enumerator.
  *
+ *  Related: see {Methods for Combining}[rdoc-ref:Array@Methods+for+Combining].
  */
 
 static VALUE
@@ -7366,62 +7621,55 @@ rb_ary_repeated_combination(VALUE ary, VALUE num)
 
 /*
  *  call-seq:
- *    array.product(*other_arrays) -> new_array
- *    array.product(*other_arrays) {|combination| ... } -> self
+ *    product(*other_arrays) -> new_array
+ *    product(*other_arrays) {|combination| ... } -> self
  *
- *  Computes and returns or yields all combinations of elements from all the Arrays,
+ *  Computes all combinations of elements from all the arrays,
  *  including both +self+ and +other_arrays+:
  *
  *  - The number of combinations is the product of the sizes of all the arrays,
  *    including both +self+ and +other_arrays+.
  *  - The order of the returned combinations is indeterminate.
  *
- *  When no block is given, returns the combinations as an \Array of Arrays:
+ *  With no block given, returns the combinations as an array of arrays:
  *
- *    a = [0, 1, 2]
- *    a1 = [3, 4]
- *    a2 = [5, 6]
- *    p = a.product(a1)
- *    p.size # => 6 # a.size * a1.size
- *    p # => [[0, 3], [0, 4], [1, 3], [1, 4], [2, 3], [2, 4]]
- *    p = a.product(a1, a2)
- *    p.size # => 12 # a.size * a1.size * a2.size
- *    p # => [[0, 3, 5], [0, 3, 6], [0, 4, 5], [0, 4, 6], [1, 3, 5], [1, 3, 6], [1, 4, 5], [1, 4, 6], [2, 3, 5], [2, 3, 6], [2, 4, 5], [2, 4, 6]]
- *
- *  If any argument is an empty \Array, returns an empty \Array.
- *
- *  If no argument is given, returns an \Array of 1-element Arrays,
- *  each containing an element of +self+:
+ *    p = [0, 1].product([2, 3])
+ *    # => [[0, 2], [0, 3], [1, 2], [1, 3]]
+ *    p.size # => 4
+ *    p = [0, 1].product([2, 3], [4, 5])
+ *    # => [[0, 2, 4], [0, 2, 5], [0, 3, 4], [0, 3, 5], [1, 2, 4], [1, 2, 5], [1, 3, 4], [1, 3,...
+ *    p.size # => 8
  *
- *    a.product # => [[0], [1], [2]]
+ *  If +self+ or any argument is empty, returns an empty array:
  *
- *  When a block is given, yields each combination as an \Array; returns +self+:
+ *    [].product([2, 3], [4, 5]) # => []
+ *    [0, 1].product([2, 3], []) # => []
  *
- *    a.product(a1) {|combination| p combination }
+ *  If no argument is given, returns an array of 1-element arrays,
+ *  each containing an element of +self+:
  *
- *  Output:
+ *    a.product # => [[0], [1], [2]]
  *
- *    [0, 3]
- *    [0, 4]
- *    [1, 3]
- *    [1, 4]
- *    [2, 3]
- *    [2, 4]
+ *  With a block given, calls the block with each combination; returns +self+:
  *
- *  If any argument is an empty \Array, does not call the block:
+ *    p = []
+ *    [0, 1].product([2, 3]) {|combination| p.push(combination) }
+ *    p # => [[0, 2], [0, 3], [1, 2], [1, 3]]
  *
- *    a.product(a1, a2, []) {|combination| fail 'Cannot happen' }
+ *  If +self+ or any argument is empty, does not call the block:
  *
- *  If no argument is given, yields each element of +self+ as a 1-element \Array:
+ *    [].product([2, 3], [4, 5]) {|combination| fail 'Cannot happen' }
+ *    # => []
+ *    [0, 1].product([2, 3], []) {|combination| fail 'Cannot happen' }
+ *    # => [0, 1]
  *
- *    a.product {|combination| p combination }
+ *  If no argument is given, calls the block with each element of +self+ as a 1-element array:
  *
- *  Output:
- *
- *    [0]
- *    [1]
- *    [2]
+ *    p = []
+ *    [0, 1].product {|combination| p.push(combination) }
+ *    p # => [[0], [1]]
  *
+ *  Related: see {Methods for Combining}[rdoc-ref:Array@Methods+for+Combining].
  */
 
 static VALUE
@@ -7514,20 +7762,20 @@ done:
 
 /*
  *  call-seq:
- *    array.take(n) -> new_array
+ *    take(count) -> new_array
  *
- *  Returns a new \Array containing the first +n+ element of +self+,
- *  where +n+ is a non-negative Integer;
- *  does not modify +self+.
+ *  Returns a new array containing the first +count+ element of +self+
+ *  (as available);
+ *  +count+ must be a non-negative numeric;
+ *  does not modify +self+:
  *
- *  Examples:
- *
- *    a = [0, 1, 2, 3, 4, 5]
- *    a.take(1) # => [0]
- *    a.take(2) # => [0, 1]
- *    a.take(50) # => [0, 1, 2, 3, 4, 5]
- *    a # => [0, 1, 2, 3, 4, 5]
+ *    a = ['a', 'b', 'c', 'd']
+ *    a.take(2)   # => ["a", "b"]
+ *    a.take(2.1) # => ["a", "b"]
+ *    a.take(50)  # => ["a", "b", "c", "d"]
+ *    a.take(0)   # => []
  *
+ *  Related: see {Methods for Fetching}[rdoc-ref:Array@Methods+for+Fetching].
  */
 
 static VALUE
@@ -7542,25 +7790,23 @@ rb_ary_take(VALUE obj, VALUE n)
 
 /*
  *  call-seq:
- *    array.take_while {|element| ... } -> new_array
- *    array.take_while -> new_enumerator
- *
- *  Returns a new \Array containing zero or more leading elements of +self+;
- *  does not modify +self+.
+ *    take_while {|element| ... } -> new_array
+ *    take_while -> new_enumerator
  *
  *  With a block given, calls the block with each successive element of +self+;
- *  stops if the block returns +false+ or +nil+;
- *  returns a new \Array containing those elements for which the block returned a truthy value:
+ *  stops iterating if the block returns +false+ or +nil+;
+ *  returns a new array containing those elements for which the block returned a truthy value:
  *
  *    a = [0, 1, 2, 3, 4, 5]
  *    a.take_while {|element| element < 3 } # => [0, 1, 2]
- *    a.take_while {|element| true } # => [0, 1, 2, 3, 4, 5]
- *    a # => [0, 1, 2, 3, 4, 5]
+ *    a.take_while {|element| true }        # => [0, 1, 2, 3, 4, 5]
+ *    a.take_while {|element| false }       # => []
  *
- *  With no block given, returns a new Enumerator:
+ *  With no block given, returns a new Enumerator.
  *
- *    [0, 1].take_while # => #<Enumerator: [0, 1]:take_while>
+ *  Does not modify +self+.
  *
+ *  Related: see {Methods for Fetching}[rdoc-ref:Array@Methods+for+Fetching].
  */
 
 static VALUE
@@ -7577,10 +7823,10 @@ rb_ary_take_while(VALUE ary)
 
 /*
  *  call-seq:
- *    array.drop(n) -> new_array
+ *    drop(count) -> new_array
  *
- *  Returns a new \Array containing all but the first +n+ element of +self+,
- *  where +n+ is a non-negative Integer;
+ *  Returns a new array containing all but the first +count+ element of +self+,
+ *  where +count+ is a non-negative integer;
  *  does not modify +self+.
  *
  *  Examples:
@@ -7589,7 +7835,9 @@ rb_ary_take_while(VALUE ary)
  *    a.drop(0) # => [0, 1, 2, 3, 4, 5]
  *    a.drop(1) # => [1, 2, 3, 4, 5]
  *    a.drop(2) # => [2, 3, 4, 5]
+ *    a.drop(9) # => []
  *
+ *  Related: see {Methods for Fetching}[rdoc-ref:Array@Methods+for+Fetching].
  */
 
 static VALUE
@@ -7608,23 +7856,20 @@ rb_ary_drop(VALUE ary, VALUE n)
 
 /*
  *  call-seq:
- *    array.drop_while {|element| ... } -> new_array
- *    array.drop_while -> new_enumerator
-
- *  Returns a new \Array containing zero or more trailing elements of +self+;
- *  does not modify +self+.
+ *    drop_while {|element| ... } -> new_array
+ *    drop_while -> new_enumerator
  *
  *  With a block given, calls the block with each successive element of +self+;
  *  stops if the block returns +false+ or +nil+;
- *  returns a new \Array _omitting_ those elements for which the block returned a truthy value:
+ *  returns a new array _omitting_ those elements for which the block returned a truthy value;
+ *  does not modify +self+:
  *
  *    a = [0, 1, 2, 3, 4, 5]
  *    a.drop_while {|element| element < 3 } # => [3, 4, 5]
  *
- *  With no block given, returns a new Enumerator:
- *
- *    [0, 1].drop_while # => # => #<Enumerator: [0, 1]:drop_while>
+ *  With no block given, returns a new Enumerator.
  *
+ *  Related: see {Methods for Fetching}[rdoc-ref:Array@Methods+for+Fetching].
  */
 
 static VALUE
@@ -7641,38 +7886,41 @@ rb_ary_drop_while(VALUE ary)
 
 /*
  *  call-seq:
- *    array.any? -> true or false
- *    array.any? {|element| ... } -> true or false
- *    array.any?(obj) -> true or false
+ *    any? -> true or false
+ *    any?(object) -> true or false
+ *    any? {|element| ... } -> true or false
  *
- *  Returns +true+ if any element of +self+ meets a given criterion.
+ *  Returns whether for any element of +self+, a given criterion is satisfied.
  *
- *  If +self+ has no element, returns +false+ and argument or block
- *  are not used.
+ *  With no block and no argument, returns whether any element of +self+ is truthy:
  *
- *  With no block given and no argument, returns +true+ if +self+ has any truthy element,
- *  +false+ otherwise:
+ *    [nil, false, []].any? # => true  # Array object is truthy.
+ *    [nil, false, {}].any? # => true  # Hash object is truthy.
+ *    [nil, false, ''].any? # => true  # String object is truthy.
+ *    [nil, false].any?     # => false # Nil and false are not truthy.
  *
- *    [nil, 0, false].any? # => true
- *    [nil, false].any? # => false
- *    [].any? # => false
+ *  With argument +object+ given,
+ *  returns whether <tt>object === ele</tt> for any element +ele+ in +self+:
  *
- *  With a block given and no argument, calls the block with each element in +self+;
- *  returns +true+ if the block returns any truthy value, +false+ otherwise:
+ *    [nil, false, 0].any?(0)          # => true
+ *    [nil, false, 1].any?(0)          # => false
+ *    [nil, false, 'food'].any?(/foo/) # => true
+ *    [nil, false, 'food'].any?(/bar/) # => false
  *
- *    [0, 1, 2].any? {|element| element > 1 } # => true
- *    [0, 1, 2].any? {|element| element > 2 } # => false
+ *  With a block given,
+ *  calls the block with each element in +self+;
+ *  returns whether the block returns any truthy value:
  *
- *  If argument +obj+ is given, returns +true+ if +obj+.<tt>===</tt> any element,
- *  +false+ otherwise:
+ *    [0, 1, 2].any? {|ele| ele < 1 } # => true
+ *    [0, 1, 2].any? {|ele| ele < 0 } # => false
+ *
+ *  With both a block and argument +object+ given,
+ *  ignores the block and uses +object+ as above.
  *
- *    ['food', 'drink'].any?(/foo/) # => true
- *    ['food', 'drink'].any?(/bar/) # => false
- *    [].any?(/foo/) # => false
- *    [0, 1, 2].any?(1) # => true
- *    [0, 1, 2].any?(3) # => false
+ *  <b>Special case</b>: returns +false+ if +self+ is empty
+ *  (regardless of any given argument or block).
  *
- *  Related: Enumerable#any?
+ *  Related: see {Methods for Querying}[rdoc-ref:Array@Methods+for+Querying].
  */
 
 static VALUE
@@ -7705,37 +7953,41 @@ rb_ary_any_p(int argc, VALUE *argv, VALUE ary)
 
 /*
  *  call-seq:
- *    array.all? -> true or false
- *    array.all? {|element| ... } -> true or false
- *    array.all?(obj) -> true or false
+ *    all? -> true or false
+ *    all?(object) -> true or false
+ *    all? {|element| ... } -> true or false
  *
- *  Returns +true+ if all elements of +self+ meet a given criterion.
+ *  Returns whether for every element of +self+,
+ *  a given criterion is satisfied.
  *
- *  If +self+ has no element, returns +true+ and argument or block
- *  are not used.
+ *  With no block and no argument,
+ *  returns whether every element of +self+ is truthy:
  *
- *  With no block given and no argument, returns +true+ if +self+ contains only truthy elements,
- *  +false+ otherwise:
+ *    [[], {}, '', 0, 0.0, Object.new].all? # => true  # All truthy objects.
+ *    [[], {}, '', 0, 0.0, nil].all?        # => false # nil is not truthy.
+ *    [[], {}, '', 0, 0.0, false].all?      # => false # false is not truthy.
+ *
+ *  With argument +object+ given, returns whether <tt>object === ele</tt>
+ *  for every element +ele+ in +self+:
  *
- *    [0, 1, :foo].all? # => true
- *    [0, nil, 2].all? # => false
- *    [].all? # => true
+ *    [0, 0, 0].all?(0)                    # => true
+ *    [0, 1, 2].all?(1)                    # => false
+ *    ['food', 'fool', 'foot'].all?(/foo/) # => true
+ *    ['food', 'drink'].all?(/foo/)        # => false
  *
- *  With a block given and no argument, calls the block with each element in +self+;
- *  returns +true+ if the block returns only truthy values, +false+ otherwise:
+ *  With a block given, calls the block with each element in +self+;
+ *  returns whether the block returns only truthy values:
  *
- *    [0, 1, 2].all? { |element| element < 3 } # => true
- *    [0, 1, 2].all? { |element| element < 2 } # => false
+ *    [0, 1, 2].all? { |ele| ele < 3 } # => true
+ *    [0, 1, 2].all? { |ele| ele < 2 } # => false
  *
- *  If argument +obj+ is given, returns +true+ if <tt>obj.===</tt> every element, +false+ otherwise:
+ *  With both a block and argument +object+ given,
+ *  ignores the block and uses +object+ as above.
  *
- *    ['food', 'fool', 'foot'].all?(/foo/) # => true
- *    ['food', 'drink'].all?(/bar/) # => false
- *    [].all?(/foo/) # => true
- *    [0, 0, 0].all?(0) # => true
- *    [0, 1, 2].all?(1) # => false
+ *  <b>Special case</b>: returns +true+ if +self+ is empty
+ *  (regardless of any given argument or block).
  *
- *  Related: Enumerable#all?
+ *  Related: see {Methods for Querying}[rdoc-ref:Array@Methods+for+Querying].
  */
 
 static VALUE
@@ -7768,34 +8020,35 @@ rb_ary_all_p(int argc, VALUE *argv, VALUE ary)
 
 /*
  *  call-seq:
- *    array.none? -> true or false
- *    array.none? {|element| ... } -> true or false
- *    array.none?(obj) -> true or false
+ *    none? -> true or false
+ *    none?(object) -> true or false
+ *    none? {|element| ... } -> true or false
  *
- *  Returns +true+ if no element of +self+ meet a given criterion.
+ *  Returns +true+ if no element of +self+ meets a given criterion, +false+ otherwise.
  *
  *  With no block given and no argument, returns +true+ if +self+ has no truthy elements,
  *  +false+ otherwise:
  *
- *    [nil, false].none? # => true
+ *    [nil, false].none?    # => true
  *    [nil, 0, false].none? # => false
- *    [].none? # => true
+ *    [].none?              # => true
  *
- *  With a block given and no argument, calls the block with each element in +self+;
+ *  With argument +object+ given, returns +false+ if for any element +element+,
+ *  <tt>object === element</tt>; +true+ otherwise:
+ *
+ *    ['food', 'drink'].none?(/bar/) # => true
+ *    ['food', 'drink'].none?(/foo/) # => false
+ *    [].none?(/foo/)                # => true
+ *    [0, 1, 2].none?(3)             # => true
+ *    [0, 1, 2].none?(1)             # => false
+ *
+ *  With a block given, calls the block with each element in +self+;
  *  returns +true+ if the block returns no truthy value, +false+ otherwise:
  *
  *    [0, 1, 2].none? {|element| element > 3 } # => true
  *    [0, 1, 2].none? {|element| element > 1 } # => false
  *
- *  If argument +obj+ is given, returns +true+ if <tt>obj.===</tt> no element, +false+ otherwise:
- *
- *    ['food', 'drink'].none?(/bar/) # => true
- *    ['food', 'drink'].none?(/foo/) # => false
- *    [].none?(/foo/) # => true
- *    [0, 1, 2].none?(3) # => true
- *    [0, 1, 2].none?(1) # => false
- *
- *  Related: Enumerable#none?
+ *  Related: see {Methods for Querying}[rdoc-ref:Array@Methods+for+Querying].
  */
 
 static VALUE
@@ -7828,9 +8081,9 @@ rb_ary_none_p(int argc, VALUE *argv, VALUE ary)
 
 /*
  *  call-seq:
- *    array.one? -> true or false
- *    array.one? {|element| ... } -> true or false
- *    array.one?(obj) -> true or false
+ *    one? -> true or false
+ *    one? {|element| ... } -> true or false
+ *    one?(object) -> true or false
  *
  *  Returns +true+ if exactly one element of +self+ meets a given criterion.
  *
@@ -7842,14 +8095,14 @@ rb_ary_none_p(int argc, VALUE *argv, VALUE ary)
  *    [nil, nil].one? # => false
  *    [].one? # => false
  *
- *  With a block given and no argument, calls the block with each element in +self+;
+ *  With a block given, calls the block with each element in +self+;
  *  returns +true+ if the block a truthy value for exactly one element, +false+ otherwise:
  *
  *    [0, 1, 2].one? {|element| element > 0 } # => false
  *    [0, 1, 2].one? {|element| element > 1 } # => true
  *    [0, 1, 2].one? {|element| element > 2 } # => false
  *
- *  If argument +obj+ is given, returns +true+ if <tt>obj.===</tt> exactly one element,
+ *  With argument +object+ given, returns +true+ if for exactly one element +element+, <tt>object === element</tt>;
  *  +false+ otherwise:
  *
  *    [0, 1, 2].one?(0) # => true
@@ -7859,7 +8112,7 @@ rb_ary_none_p(int argc, VALUE *argv, VALUE ary)
  *    ['food', 'drink'].one?(/foo/) # => true
  *    [].one?(/foo/) # => false
  *
- *  Related: Enumerable#one?
+ *  Related: see {Methods for Querying}[rdoc-ref:Array@Methods+for+Querying].
  */
 
 static VALUE
@@ -7902,11 +8155,11 @@ rb_ary_one_p(int argc, VALUE *argv, VALUE ary)
 
 /*
  *  call-seq:
- *    array.dig(index, *identifiers) -> object
+ *    dig(index, *identifiers) -> object
  *
- *  Finds and returns the object in nested objects
- *  that is specified by +index+ and +identifiers+.
- *  The nested objects may be instances of various classes.
+ *  Finds and returns the object in nested object
+ *  specified by +index+ and +identifiers+;
+ *  the nested objects may be instances of various classes.
  *  See {Dig Methods}[rdoc-ref:dig_methods.rdoc].
  *
  *  Examples:
@@ -7917,6 +8170,7 @@ rb_ary_one_p(int argc, VALUE *argv, VALUE ary)
  *    a.dig(1, 2, 0) # => :bat
  *    a.dig(1, 2, 3) # => nil
  *
+ *  Related: see {Methods for Fetching}[rdoc-ref:Array@Methods+for+Fetching].
  */
 
 static VALUE
@@ -7945,40 +8199,41 @@ finish_exact_sum(long n, VALUE r, VALUE v, int z)
 
 /*
  * call-seq:
- *   array.sum(init = 0) -> object
- *   array.sum(init = 0) {|element| ... } -> object
+ *   sum(init = 0) -> object
+ *   sum(init = 0) {|element| ... } -> object
  *
- *  When no block is given, returns the object equivalent to:
+ *  With no block given, returns the sum of +init+ and all elements of +self+;
+ *  for array +array+ and value +init+, equivalent to:
  *
  *    sum = init
  *    array.each {|element| sum += element }
  *    sum
  *
- *  For example, <tt>[e1, e2, e3].sum</tt> returns <tt>init + e1 + e2 + e3</tt>.
+ *  For example, <tt>[e0, e1, e2].sum</tt> returns <tt>init + e0 + e1 + e2</tt>.
  *
  *  Examples:
  *
- *    a = [0, 1, 2, 3]
- *    a.sum # => 6
- *    a.sum(100) # => 106
+ *    [0, 1, 2, 3].sum                 # => 6
+ *    [0, 1, 2, 3].sum(100)            # => 106
+ *    ['abc', 'def', 'ghi'].sum('jkl') # => "jklabcdefghi"
+ *    [[:foo, :bar], ['foo', 'bar']].sum([2, 3])
+ *    # => [2, 3, :foo, :bar, "foo", "bar"]
  *
- *  The elements need not be numeric, but must be <tt>+</tt>-compatible
- *  with each other and with +init+:
+ *  The +init+ value and elements need not be numeric, but must all be <tt>+</tt>-compatible:
  *
- *    a = ['abc', 'def', 'ghi']
- *    a.sum('jkl') # => "jklabcdefghi"
+ *    # Raises TypeError: Array can't be coerced into Integer.
+ *    [[:foo, :bar], ['foo', 'bar']].sum(2)
  *
- *  When a block is given, it is called with each element
- *  and the block's return value (instead of the element itself) is used as the addend:
+ *  With a block given, calls the block with each element of +self+;
+ *  the block's return value (instead of the element itself) is used as the addend:
  *
- *    a = ['zero', 1, :two]
- *    s = a.sum('Coerced and concatenated: ') {|element| element.to_s }
- *    s # => "Coerced and concatenated: zero1two"
+ *    ['zero', 1, :two].sum('Coerced and concatenated: ') {|element| element.to_s }
+ *    # => "Coerced and concatenated: zero1two"
  *
  *  Notes:
  *
  *  - Array#join and Array#flatten may be faster than Array#sum
- *    for an \Array of Strings or an \Array of Arrays.
+ *    for an array of strings or an array of arrays.
  *  - Array#sum method may not respect method redefinition of "+" methods such as Integer#+.
  *
  */
@@ -8000,7 +8255,11 @@ rb_ary_sum(int argc, VALUE *argv, VALUE ary)
     n = 0;
     r = Qundef;
 
-    if (!FIXNUM_P(v) && !RB_BIGNUM_TYPE_P(v) && !RB_TYPE_P(v, T_RATIONAL)) {
+    bool init_is_float = RB_FLOAT_TYPE_P(v);
+    if (init_is_float) {
+        v = LONG2FIX(0);
+    }
+    else if (!RB_INTEGER_TYPE_P(v) && !RB_TYPE_P(v, T_RATIONAL)) {
         i = 0;
         goto init_is_a_value;
     }
@@ -8028,12 +8287,13 @@ rb_ary_sum(int argc, VALUE *argv, VALUE ary)
             goto not_exact;
     }
     v = finish_exact_sum(n, r, v, argc!=0);
+    if (init_is_float) v = rb_float_plus(argv[0], v);
     return v;
 
   not_exact:
     v = finish_exact_sum(n, r, v, i!=0);
 
-    if (RB_FLOAT_TYPE_P(e)) {
+    if (init_is_float ? (--i, e = argv[0], true) : RB_FLOAT_TYPE_P(e)) {
         /*
          * Kahan-Babuska balancing compensated summation algorithm
          * See https://link.springer.com/article/10.1007/s00607-005-0139-x
@@ -8100,6 +8360,7 @@ rb_ary_sum(int argc, VALUE *argv, VALUE ary)
     return v;
 }
 
+/* :nodoc: */
 static VALUE
 rb_ary_deconstruct(VALUE ary)
 {
@@ -8107,15 +8368,37 @@ rb_ary_deconstruct(VALUE ary)
 }
 
 /*
- *  An \Array is an ordered, integer-indexed collection of objects, called _elements_.
- *  Any object (even another array) may be an array element,
- *  and an array can contain objects of different types.
+ *  An \Array object is an ordered, integer-indexed collection of objects,
+ *  called _elements_;
+ *  the object represents
+ *  an {array data structure}[https://en.wikipedia.org/wiki/Array_(data_structure)].
+ *
+ *  An element may be any object (even another array);
+ *  elements may be any mixture of objects of different types.
+ *
+ *  Important data structures that use arrays include:
+ *
+ *  - {Coordinate vector}[https://en.wikipedia.org/wiki/Coordinate_vector].
+ *  - {Matrix}[https://en.wikipedia.org/wiki/Matrix_(mathematics)].
+ *  - {Heap}[https://en.wikipedia.org/wiki/Heap_(data_structure)].
+ *  - {Hash table}[https://en.wikipedia.org/wiki/Hash_table].
+ *  - {Deque (double-ended queue)}[https://en.wikipedia.org/wiki/Double-ended_queue].
+ *  - {Queue}[https://en.wikipedia.org/wiki/Queue_(abstract_data_type)].
+ *  - {Stack}[https://en.wikipedia.org/wiki/Stack_(abstract_data_type)].
+ *
+ *  There are also array-like data structures:
+ *
+ *  - {Associative array}[https://en.wikipedia.org/wiki/Associative_array] (see Hash).
+ *  - {Directory}[https://en.wikipedia.org/wiki/Directory_(computing)] (see Dir).
+ *  - {Environment}[https://en.wikipedia.org/wiki/Environment_variable] (see ENV).
+ *  - {Set}[https://en.wikipedia.org/wiki/Set_(abstract_data_type)] (see Set).
+ *  - {String}[https://en.wikipedia.org/wiki/String_(computer_science)] (see String).
  *
  *  == \Array Indexes
  *
  *  \Array indexing starts at 0, as in C or Java.
  *
- *  A positive index is an offset from the first element:
+ *  A non-negative index is an offset from the first element:
  *
  *  - Index 0 indicates the first element.
  *  - Index 1 indicates the second element.
@@ -8127,6 +8410,9 @@ rb_ary_deconstruct(VALUE ary)
  *  - Index -2 indicates the next-to-last element.
  *  - ...
  *
+ *
+ *  === In-Range and Out-of-Range Indexes
+ *
  *  A non-negative index is <i>in range</i> if and only if it is smaller than
  *  the size of the array.  For a 3-element array:
  *
@@ -8139,31 +8425,32 @@ rb_ary_deconstruct(VALUE ary)
  *  - Indexes -1 through -3 are in range.
  *  - Index -4 is out of range.
  *
+ *  === Effective Index
+ *
  *  Although the effective index into an array is always an integer,
- *  some methods (both within and outside of class \Array)
+ *  some methods (both within class \Array and elsewhere)
  *  accept one or more non-integer arguments that are
  *  {integer-convertible objects}[rdoc-ref:implicit_conversion.rdoc@Integer-Convertible+Objects].
  *
- *
  *  == Creating Arrays
  *
  *  You can create an \Array object explicitly with:
  *
- *  - An {array literal}[rdoc-ref:literals.rdoc@Array+Literals]:
+ *  - An {array literal}[rdoc-ref:syntax/literals.rdoc@Array+Literals]:
  *
  *      [1, 'one', :one, [2, 'two', :two]]
  *
- *  - A {%w or %W: string-array Literal}[rdoc-ref:literals.rdoc@25w+and+-25W-3A+String-Array+Literals]:
+ *  - A {%w or %W string-array Literal}[rdoc-ref:syntax/literals.rdoc@w-and-w-String-Array-Literals]:
  *
  *      %w[foo bar baz] # => ["foo", "bar", "baz"]
  *      %w[1 % *]       # => ["1", "%", "*"]
  *
- *  - A {%i pr %I: symbol-array Literal}[rdoc-ref:literals.rdoc@25i+and+-25I-3A+Symbol-Array+Literals]:
+ *  - A {%i or %I symbol-array Literal}[rdoc-ref:syntax/literals.rdoc@i+and-I-Symbol-Array+Literals]:
  *
  *      %i[foo bar baz] # => [:foo, :bar, :baz]
  *      %i[1 % *]       # => [:"1", :%, :*]
  *
- *  - \Method Kernel#Array:
+ *  - Method Kernel#Array:
  *
  *      Array(["a", "b"])             # => ["a", "b"]
  *      Array(1..5)                   # => [1, 2, 3, 4, 5]
@@ -8172,7 +8459,7 @@ rb_ary_deconstruct(VALUE ary)
  *      Array(1)                      # => [1]
  *      Array({:a => "a", :b => "b"}) # => [[:a, "a"], [:b, "b"]]
  *
- *  - \Method Array.new:
+ *  - Method Array.new:
  *
  *      Array.new               # => []
  *      Array.new(3)            # => [nil, nil, nil]
@@ -8227,8 +8514,8 @@ rb_ary_deconstruct(VALUE ary)
  *
  *  == Example Usage
  *
- *  In addition to the methods it mixes in through the Enumerable module, the
- *  \Array class has proprietary methods for accessing, searching and otherwise
+ *  In addition to the methods it mixes in through the Enumerable module,
+ *  class \Array has proprietary methods for accessing, searching and otherwise
  *  manipulating arrays.
  *
  *  Some of the more common ones are illustrated below.
@@ -8278,7 +8565,7 @@ rb_ary_deconstruct(VALUE ary)
  *
  *  == Obtaining Information about an \Array
  *
- *  Arrays keep track of their own length at all times.  To query an array
+ *  An array keeps track of its own length at all times.  To query an array
  *  about the number of elements it contains, use #length, #count or #size.
  *
  *    browsers = ['Chrome', 'Firefox', 'Safari', 'Opera', 'IE']
@@ -8293,7 +8580,7 @@ rb_ary_deconstruct(VALUE ary)
  *
  *    browsers.include?('Konqueror') #=> false
  *
- *  == Adding Items to Arrays
+ *  == Adding Items to an \Array
  *
  *  Items can be added to the end of an array by using either #push or #<<
  *
@@ -8354,11 +8641,11 @@ rb_ary_deconstruct(VALUE ary)
  *     arr = [2, 5, 6, 556, 6, 6, 8, 9, 0, 123, 556]
  *     arr.uniq #=> [2, 5, 6, 556, 8, 9, 0, 123]
  *
- *  == Iterating over Arrays
+ *  == Iterating over an \Array
  *
- *  Like all classes that include the Enumerable module, \Array has an each
+ *  Like all classes that include the Enumerable module, class \Array has an each
  *  method, which defines what elements should be iterated over and how.  In
- *  case of Array's #each, all elements in the \Array instance are yielded to
+ *  case of Array#each, all elements in +self+ are yielded to
  *  the supplied block in sequence.
  *
  *  Note that this operation leaves the array unchanged.
@@ -8418,10 +8705,10 @@ rb_ary_deconstruct(VALUE ary)
  *
  *  == What's Here
  *
- *  First, what's elsewhere. \Class \Array:
+ *  First, what's elsewhere. Class \Array:
  *
- *  - Inherits from {class Object}[rdoc-ref:Object@What-27s+Here].
- *  - Includes {module Enumerable}[rdoc-ref:Enumerable@What-27s+Here],
+ *  - Inherits from {class Object}[rdoc-ref:Object@Whats-Here].
+ *  - Includes {module Enumerable}[rdoc-ref:Enumerable@Whats-Here],
  *    which provides dozens of additional methods.
  *
  *  Here, class \Array provides methods that are useful for:
@@ -8443,148 +8730,132 @@ rb_ary_deconstruct(VALUE ary)
  *  - ::new: Returns a new array.
  *  - ::try_convert: Returns a new array created from a given object.
  *
+ *  See also {Creating Arrays}[rdoc-ref:Array@Creating+Arrays].
+ *
  *  === Methods for Querying
  *
- *  - #length, #size: Returns the count of elements.
- *  - #include?: Returns whether any element <tt>==</tt> a given object.
- *  - #empty?: Returns whether there are no elements.
  *  - #all?: Returns whether all elements meet a given criterion.
  *  - #any?: Returns whether any element meets a given criterion.
+ *  - #count: Returns the count of elements that meet a given criterion.
+ *  - #empty?: Returns whether there are no elements.
+ *  - #find_index (aliased as #index): Returns the index of the first element that meets a given criterion.
+ *  - #hash: Returns the integer hash code.
+ *  - #include?: Returns whether any element <tt>==</tt> a given object.
+ *  - #length (aliased as #size): Returns the count of elements.
  *  - #none?: Returns whether no element <tt>==</tt> a given object.
  *  - #one?: Returns whether exactly one element <tt>==</tt> a given object.
- *  - #count: Returns the count of elements that meet a given criterion.
- *  - #find_index, #index: Returns the index of the first element that meets a given criterion.
  *  - #rindex: Returns the index of the last element that meets a given criterion.
- *  - #hash: Returns the integer hash code.
  *
  *  === Methods for Comparing
  *
- *  - #<=>: Returns -1, 0, or 1 * as +self+ is less than, equal to, or
- *    greater than a given object.
- *  - #==: Returns whether each element in +self+ is <tt>==</tt> to the corresponding element
- *    in a given object.
- *  - #eql?: Returns whether each element in +self+ is <tt>eql?</tt> to the corresponding
- *    element in a given object.
+ *  - #<=>: Returns -1, 0, or 1, as +self+ is less than, equal to, or greater than a given object.
+ *  - #==: Returns whether each element in +self+ is <tt>==</tt> to the corresponding element in a given object.
+ *  - #eql?: Returns whether each element in +self+ is <tt>eql?</tt> to the corresponding element in a given object.
 
  *  === Methods for Fetching
  *
  *  These methods do not modify +self+.
  *
- *  - #[]: Returns one or more elements.
- *  - #fetch: Returns the element at a given offset.
- *  - #first: Returns one or more leading elements.
- *  - #last: Returns one or more trailing elements.
- *  - #max: Returns one or more maximum-valued elements,
- *    as determined by <tt><=></tt> or a given block.
- *  - #min: Returns one or more minimum-valued elements,
- *    as determined by <tt><=></tt> or a given block.
- *  - #minmax: Returns the minimum-valued and maximum-valued elements,
- *    as determined by <tt><=></tt> or a given block.
- *  - #assoc: Returns the first element that is an array
- *    whose first element <tt>==</tt> a given object.
- *  - #rassoc: Returns the first element that is an array
- *    whose second element <tt>==</tt> a given object.
+ *  - #[] (aliased as #slice): Returns consecutive elements as determined by a given argument.
+ *  - #assoc: Returns the first element that is an array whose first element <tt>==</tt> a given object.
  *  - #at: Returns the element at a given offset.
- *  - #values_at: Returns the elements at given offsets.
- *  - #dig: Returns the object in nested objects
- *    that is specified by a given index and additional arguments.
+ *  - #bsearch: Returns an element selected via a binary search as determined by a given block.
+ *  - #bsearch_index: Returns the index of an element selected via a binary search as determined by a given block.
+ *  - #compact: Returns an array containing all non-+nil+ elements.
+ *  - #dig: Returns the object in nested objects that is specified by a given index and additional arguments.
  *  - #drop: Returns trailing elements as determined by a given index.
- *  - #take: Returns leading elements as determined by a given index.
  *  - #drop_while: Returns trailing elements as determined by a given block.
- *  - #take_while: Returns leading elements as determined by a given block.
- *  - #slice: Returns consecutive elements as determined by a given argument.
- *  - #sort: Returns all elements in an order determined by <tt><=></tt> or a given block.
+ *  - #fetch: Returns the element at a given offset.
+ *  - #fetch_values: Returns elements at given offsets.
+ *  - #first: Returns one or more leading elements.
+ *  - #last: Returns one or more trailing elements.
+ *  - #max: Returns one or more maximum-valued elements, as determined by <tt>#<=></tt> or a given block.
+ *  - #min: Returns one or more minimum-valued elements, as determined by <tt>#<=></tt> or a given block.
+ *  - #minmax: Returns the minimum-valued and maximum-valued elements, as determined by <tt>#<=></tt> or a given block.
+ *  - #rassoc: Returns the first element that is an array whose second element <tt>==</tt> a given object.
+ *  - #reject: Returns an array containing elements not rejected by a given block.
  *  - #reverse: Returns all elements in reverse order.
- *  - #compact: Returns an array containing all non-+nil+ elements.
- *  - #select, #filter: Returns an array containing elements selected by a given block.
- *  - #uniq: Returns an array containing non-duplicate elements.
  *  - #rotate: Returns all elements with some rotated from one end to the other.
- *  - #bsearch: Returns an element selected via a binary search
- *    as determined by a given block.
- *  - #bsearch_index: Returns the index of an element selected via a binary search
- *    as determined by a given block.
  *  - #sample: Returns one or more random elements.
+ *  - #select (aliased as #filter): Returns an array containing elements selected by a given block.
  *  - #shuffle: Returns elements in a random order.
+ *  - #sort: Returns all elements in an order determined by <tt>#<=></tt> or a given block.
+ *  - #take: Returns leading elements as determined by a given index.
+ *  - #take_while: Returns leading elements as determined by a given block.
+ *  - #uniq: Returns an array containing non-duplicate elements.
+ *  - #values_at: Returns the elements at given offsets.
  *
  *  === Methods for Assigning
  *
  *  These methods add, replace, or reorder elements in +self+.
  *
+ *  - #<<: Appends an element.
  *  - #[]=: Assigns specified elements with a given object.
- *  - #push, #append, #<<: Appends trailing elements.
- *  - #unshift, #prepend: Prepends leading elements.
- *  - #insert: Inserts given objects at a given offset; does not replace elements.
  *  - #concat: Appends all elements from given arrays.
  *  - #fill: Replaces specified elements with specified objects.
- *  - #replace: Replaces the content of +self+ with the content of a given array.
+ *  - #flatten!: Replaces each nested array in +self+ with the elements from that array.
+ *  - #initialize_copy (aliased as #replace): Replaces the content of +self+ with the content of a given array.
+ *  - #insert: Inserts given objects at a given offset; does not replace elements.
+ *  - #push (aliased as #append): Appends elements.
  *  - #reverse!: Replaces +self+ with its elements reversed.
  *  - #rotate!: Replaces +self+ with its elements rotated.
  *  - #shuffle!: Replaces +self+ with its elements in random order.
- *  - #sort!: Replaces +self+ with its elements sorted,
- *    as determined by <tt><=></tt> or a given block.
+ *  - #sort!: Replaces +self+ with its elements sorted, as determined by <tt>#<=></tt> or a given block.
  *  - #sort_by!: Replaces +self+ with its elements sorted, as determined by a given block.
+ *  - #unshift (aliased as #prepend): Prepends leading elements.
  *
  *  === Methods for Deleting
  *
  *  Each of these methods removes elements from +self+:
  *
- *  - #pop: Removes and returns the last element.
- *  - #shift:  Removes and returns the first element.
+ *  - #clear: Removes all elements.
  *  - #compact!: Removes all +nil+ elements.
  *  - #delete: Removes elements equal to a given object.
  *  - #delete_at: Removes the element at a given offset.
  *  - #delete_if: Removes elements specified by a given block.
  *  - #keep_if: Removes elements not specified by a given block.
+ *  - #pop: Removes and returns the last element.
  *  - #reject!: Removes elements specified by a given block.
- *  - #select!, #filter!: Removes elements not specified by a given block.
+ *  - #select! (aliased as #filter!): Removes elements not specified by a given block.
+ *  - #shift:  Removes and returns the first element.
  *  - #slice!: Removes and returns a sequence of elements.
  *  - #uniq!: Removes duplicates.
  *
  *  === Methods for Combining
  *
  *  - #&: Returns an array containing elements found both in +self+ and a given array.
- *  - #intersection: Returns an array containing elements found both in +self+
- *    and in each given array.
  *  - #+: Returns an array containing all elements of +self+ followed by all elements of a given array.
  *  - #-: Returns an array containing all elements of +self+ that are not found in a given array.
- *  - #|: Returns an array containing all elements of +self+ and all elements of a given array,
- *    duplicates removed.
- *  - #union: Returns an array containing all elements of +self+ and all elements of given arrays,
- *    duplicates removed.
- *  - #difference: Returns an array containing all elements of +self+ that are not found
- *    in any of the given arrays..
+ *  - #|: Returns an array containing all element of +self+ and all elements of a given array, duplicates removed.
+ *  - #difference: Returns an array containing all elements of +self+ that are not found in any of the given arrays..
+ *  - #intersection: Returns an array containing elements found both in +self+ and in each given array.
  *  - #product: Returns or yields all combinations of elements from +self+ and given arrays.
+ *  - #reverse: Returns an array containing all elements of +self+ in reverse order.
+ *  - #union: Returns an array containing all elements of +self+ and all elements of given arrays, duplicates removed.
  *
  *  === Methods for Iterating
  *
+ *  - #combination: Calls a given block with combinations of elements of +self+; a combination does not use the same element more than once.
+ *  - #cycle: Calls a given block with each element, then does so again, for a specified number of times, or forever.
  *  - #each: Passes each element to a given block.
- *  - #reverse_each:  Passes each element, in reverse order, to a given block.
  *  - #each_index: Passes each element index to a given block.
- *  - #cycle: Calls a given block with each element, then does so again,
- *    for a specified number of times, or forever.
- *  - #combination: Calls a given block with combinations of elements of +self+;
- *    a combination does not use the same element more than once.
- *  - #permutation: Calls a given block with permutations of elements of +self+;
- *    a permutation does not use the same element more than once.
- *  - #repeated_combination: Calls a given block with combinations of elements of +self+;
- *    a combination may use the same element more than once.
- *  - #repeated_permutation: Calls a given block with permutations of elements of +self+;
- *    a permutation may use the same element more than once.
+ *  - #permutation: Calls a given block with permutations of elements of +self+; a permutation does not use the same element more than once.
+ *  - #repeated_combination: Calls a given block with combinations of elements of +self+; a combination may use the same element more than once.
+ *  - #repeated_permutation: Calls a given block with permutations of elements of +self+; a permutation may use the same element more than once.
+ *  - #reverse_each:  Passes each element, in reverse order, to a given block.
  *
  *  === Methods for Converting
  *
- *  - #map, #collect: Returns an array containing the block return-value for each element.
- *  - #map!, #collect!: Replaces each element with a block return-value.
+ *  - #collect (aliased as #map): Returns an array containing the block return-value for each element.
+ *  - #collect! (aliased as #map!): Replaces each element with a block return-value.
  *  - #flatten: Returns an array that is a recursive flattening of +self+.
- *  - #flatten!: Replaces each nested array in +self+ with the elements from that array.
- *  - #inspect, #to_s: Returns a new String containing the elements.
- *  - #join: Returns a newsString containing the elements joined by the field separator.
+ *  - #inspect (aliased as #to_s): Returns a new String containing the elements.
+ *  - #join: Returns a new String containing the elements joined by the field separator.
  *  - #to_a: Returns +self+ or a new array containing all elements.
  *  - #to_ary: Returns +self+.
  *  - #to_h: Returns a new hash formed from the elements.
  *  - #transpose: Transposes +self+, which must be an array of arrays.
- *  - #zip: Returns a new array of arrays containing +self+ and given arrays;
- *    follow the link for details.
+ *  - #zip: Returns a new array of arrays containing +self+ and given arrays.
  *
  *  === Other Methods
  *
@@ -8595,7 +8866,6 @@ rb_ary_deconstruct(VALUE ary)
  *    - With string argument +field_separator+, a new string that is equivalent to
  *      <tt>join(field_separator)</tt>.
  *
- *  - #abbrev: Returns a hash of unambiguous abbreviations for elements.
  *  - #pack: Packs the elements into a binary sequence.
  *  - #sum: Returns a sum of elements according to either <tt>+</tt> or a given block.
  */
@@ -8603,6 +8873,8 @@ rb_ary_deconstruct(VALUE ary)
 void
 Init_Array(void)
 {
+    fake_ary_flags = init_fake_ary_flags();
+
     rb_cArray  = rb_define_class("Array", rb_cObject);
     rb_include_module(rb_cArray, rb_mEnumerable);
 
@@ -8646,6 +8918,9 @@ Init_Array(void)
     rb_define_method(rb_cArray, "length", rb_ary_length, 0);
     rb_define_method(rb_cArray, "size", rb_ary_length, 0);
     rb_define_method(rb_cArray, "empty?", rb_ary_empty_p, 0);
+    rb_define_method(rb_cArray, "find", rb_ary_find, -1);
+    rb_define_method(rb_cArray, "detect", rb_ary_find, -1);
+    rb_define_method(rb_cArray, "rfind", rb_ary_rfind, -1);
     rb_define_method(rb_cArray, "find_index", rb_ary_index, -1);
     rb_define_method(rb_cArray, "index", rb_ary_index, -1);
     rb_define_method(rb_cArray, "rindex", rb_ary_rindex, -1);
@@ -8723,8 +8998,12 @@ Init_Array(void)
     rb_define_method(rb_cArray, "one?", rb_ary_one_p, -1);
     rb_define_method(rb_cArray, "dig", rb_ary_dig, -1);
     rb_define_method(rb_cArray, "sum", rb_ary_sum, -1);
+    rb_define_method(rb_cArray, "freeze", rb_ary_freeze, 0);
 
     rb_define_method(rb_cArray, "deconstruct", rb_ary_deconstruct, 0);
+
+    rb_cArray_empty_frozen = RB_OBJ_SET_SHAREABLE(rb_ary_freeze(rb_ary_new()));
+    rb_vm_register_global_object(rb_cArray_empty_frozen);
 }
 
 #include "array.rbinc"
diff --git a/array.rb b/array.rb
index d17f374235..7ee4e09a4c 100644
--- a/array.rb
+++ b/array.rb
@@ -1,62 +1,97 @@
 class Array
   # call-seq:
-  #    array.shuffle!(random: Random) -> array
+  #   shuffle!(random: Random) -> self
   #
-  # Shuffles the elements of +self+ in place.
-  #    a = [1, 2, 3] #=> [1, 2, 3]
-  #    a.shuffle!    #=> [2, 3, 1]
-  #    a             #=> [2, 3, 1]
+  # Shuffles all elements in +self+ into a random order,
+  # as selected by the object given by the keyword argument +random+.
+  # Returns +self+:
   #
-  # The optional +random+ argument will be used as the random number generator:
-  #    a.shuffle!(random: Random.new(1))  #=> [1, 3, 2]
+  #   a =             [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
+  #   a.shuffle! # => [5, 3, 8, 7, 6, 1, 9, 4, 2, 0]
+  #   a.shuffle! # => [9, 4, 0, 6, 2, 8, 1, 5, 3, 7]
+  #
+  # Duplicate elements are included:
+  #
+  #   a =             [0, 1, 0, 1, 0, 1, 0, 1, 0, 1]
+  #   a.shuffle! # => [1, 0, 0, 1, 1, 0, 1, 0, 0, 1]
+  #   a.shuffle! # => [0, 1, 0, 1, 1, 0, 1, 0, 1, 0]
+  #
+  # The object given with the keyword argument +random+ is used as the random number generator.
+  #
+  # Related: see {Methods for Assigning}[rdoc-ref:Array@Methods+for+Assigning].
   def shuffle!(random: Random)
     Primitive.rb_ary_shuffle_bang(random)
   end
 
   # call-seq:
-  #    array.shuffle(random: Random) -> new_ary
+  #   shuffle(random: Random) -> new_array
+  #
+  # Returns a new array containing all elements from +self+ in a random order,
+  # as selected by the object given by the keyword argument +random+:
   #
-  # Returns a new array with elements of +self+ shuffled.
-  #    a = [1, 2, 3] #=> [1, 2, 3]
-  #    a.shuffle     #=> [2, 3, 1]
-  #    a             #=> [1, 2, 3]
+  #   a =            [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
+  #   a.shuffle # => [0, 8, 1, 9, 6, 3, 4, 7, 2, 5]
+  #   a.shuffle # => [8, 9, 0, 5, 1, 2, 6, 4, 7, 3]
   #
-  # The optional +random+ argument will be used as the random number generator:
-  #    a.shuffle(random: Random.new(1))  #=> [1, 3, 2]
+  # Duplicate elements are included:
+  #
+  #   a =            [0, 1, 0, 1, 0, 1, 0, 1, 0, 1]
+  #   a.shuffle # => [1, 0, 1, 1, 0, 0, 1, 0, 0, 1]
+  #   a.shuffle # => [1, 1, 0, 0, 0, 1, 1, 0, 0, 1]
+  #
+  # The object given with the keyword argument +random+ is used as the random number generator.
+  #
+  # Related: see {Methods for Fetching}[rdoc-ref:Array@Methods+for+Fetching].
   def shuffle(random: Random)
     Primitive.rb_ary_shuffle(random)
   end
 
   # call-seq:
-  #    array.sample(random: Random) -> object
-  #    array.sample(n, random: Random) -> new_ary
+  #   sample(random: Random) -> object
+  #   sample(count, random: Random) -> new_ary
   #
-  # Returns random elements from +self+.
+  # Returns random elements from +self+,
+  # as selected by the object given by the keyword argument +random+.
   #
-  # When no arguments are given, returns a random element from +self+:
-  #    a = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
-  #    a.sample # => 3
-  #    a.sample # => 8
-  # If +self+ is empty, returns +nil+.
+  # With no argument +count+ given, returns one random element from +self+:
+  #
+  #   a = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
+  #   a.sample # => 3
+  #   a.sample # => 8
+  #
+  # Returns +nil+ if +self+ is empty:
+  #
+  #   [].sample # => nil
+  #
+  # With a non-negative numeric argument +count+ given,
+  # returns a new array containing +count+ random elements from +self+:
+  #
+  #   a.sample(3) # => [8, 9, 2]
+  #   a.sample(6) # => [9, 6, 0, 3, 1, 4]
+  #
+  # The order of the result array is unrelated to the order of +self+.
+  #
+  # Returns a new empty array if +self+ is empty:
+  #
+  #   [].sample(4) # => []
+  #
+  # May return duplicates in +self+:
+  #
+  #   a = [1, 1, 1, 2, 2, 3]
+  #   a.sample(a.size) # => [1, 1, 3, 2, 1, 2]
   #
-  # When argument +n+ is given, returns a new \Array containing +n+ random
-  # elements from +self+:
-  #    a.sample(3) # => [8, 9, 2]
-  #    a.sample(6) # => [9, 6, 10, 3, 1, 4]
   # Returns no more than <tt>a.size</tt> elements
   # (because no new duplicates are introduced):
-  #    a.sample(a.size * 2) # => [6, 4, 1, 8, 5, 9, 10, 2, 3, 7]
-  # But +self+ may contain duplicates:
-  #    a = [1, 1, 1, 2, 2, 3]
-  #    a.sample(a.size * 2) # => [1, 1, 3, 2, 1, 2]
-  # The argument +n+ must be a non-negative numeric value.
-  # The order of the result array is unrelated to the order of +self+.
-  # Returns a new empty \Array if +self+ is empty.
   #
-  # The optional +random+ argument will be used as the random number generator:
-  #    a = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
-  #    a.sample(random: Random.new(1))     #=> 6
-  #    a.sample(4, random: Random.new(1))  #=> [6, 10, 9, 2]
+  #   a.sample(50) # => [6, 4, 1, 8, 5, 9, 0, 2, 3, 7]
+  #
+  # The object given with the keyword argument +random+ is used as the random number generator:
+  #
+  #   a = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
+  #   a.sample(random: Random.new(1))     # => 6
+  #   a.sample(4, random: Random.new(1))  # => [6, 10, 9, 2]
+  #
+  # Related: see {Methods for Fetching}[rdoc-ref:Array@Methods+for+Fetching].
   def sample(n = (ary = false), random: Random)
     if Primitive.mandatory_only?
       # Primitive.cexpr! %{ rb_ary_sample(self, rb_cRandom, Qfalse, Qfalse) }
@@ -68,12 +103,12 @@ class Array
   end
 
   # call-seq:
-  #   array.first -> object or nil
-  #   array.first(n) -> new_array
+  #   first -> object or nil
+  #   first(count) -> new_array
   #
-  # Returns elements from +self+; does not modify +self+.
+  # Returns elements from +self+, or +nil+; does not modify +self+.
   #
-  # When no argument is given, returns the first element:
+  # With no argument given, returns the first element (if available):
   #
   #   a = [:foo, 'bar', 2]
   #   a.first # => :foo
@@ -81,23 +116,16 @@ class Array
   #
   # If +self+ is empty, returns +nil+.
   #
-  # When non-negative Integer argument +n+ is given,
-  # returns the first +n+ elements in a new \Array:
-  #
-  #   a = [:foo, 'bar', 2]
-  #   a.first(2) # => [:foo, "bar"]
+  #   [].first # => nil
   #
-  # If <tt>n >= array.size</tt>, returns all elements:
+  # With a non-negative integer argument +count+ given,
+  # returns the first +count+ elements (as available) in a new array:
   #
-  #   a = [:foo, 'bar', 2]
+  #   a.first(0)  # => []
+  #   a.first(2)  # => [:foo, "bar"]
   #   a.first(50) # => [:foo, "bar", 2]
   #
-  # If <tt>n == 0</tt> returns an new empty \Array:
-  #
-  #   a = [:foo, 'bar', 2]
-  #   a.first(0) # []
-  #
-  # Related: #last.
+  # Related: see {Methods for Querying}[rdoc-ref:Array@Methods+for+Querying].
   def first n = unspecified = true
     if Primitive.mandatory_only?
       Primitive.attr! :leaf
@@ -112,36 +140,29 @@ class Array
   end
 
   # call-seq:
-  #   array.last  -> object or nil
-  #   array.last(n) -> new_array
+  #  last  -> last_object or nil
+  #  last(count) -> new_array
   #
-  # Returns elements from +self+; +self+ is not modified.
+  # Returns elements from +self+, or +nil+; +self+ is not modified.
   #
-  # When no argument is given, returns the last element:
+  # With no argument given, returns the last element, or +nil+ if +self+ is empty:
   #
   #   a = [:foo, 'bar', 2]
   #   a.last # => 2
   #   a # => [:foo, "bar", 2]
+  #   [].last # => nil
   #
-  # If +self+ is empty, returns +nil+.
   #
-  # When non-negative Integer argument +n+ is given,
-  # returns the last +n+ elements in a new \Array:
-  #
-  #   a = [:foo, 'bar', 2]
-  #   a.last(2) # => ["bar", 2]
-  #
-  # If <tt>n >= array.size</tt>, returns all elements:
+  # With non-negative integer argument +count+ given,
+  # returns a new array containing the trailing +count+ elements of +self+, as available:
   #
   #   a = [:foo, 'bar', 2]
+  #   a.last(2)  # => ["bar", 2]
   #   a.last(50) # => [:foo, "bar", 2]
+  #   a.last(0)  # => []
+  #   [].last(3) # => []
   #
-  # If <tt>n == 0</tt>, returns an new empty \Array:
-  #
-  #   a = [:foo, 'bar', 2]
-  #   a.last(0) # []
-  #
-  # Related: #first.
+  # Related: see {Methods for Fetching}[rdoc-ref:Array@Methods+for+Fetching].
   def last n = unspecified = true
     if Primitive.mandatory_only?
       Primitive.attr! :leaf
@@ -154,4 +175,133 @@ class Array
       end
     end
   end
+
+  # call-seq:
+  #   fetch_values(*indexes) -> new_array
+  #   fetch_values(*indexes) { |index| ... } -> new_array
+  #
+  # With no block given, returns a new array containing the elements of +self+
+  # at the offsets specified by +indexes+. Each of the +indexes+ must be an
+  # {integer-convertible object}[rdoc-ref:implicit_conversion.rdoc@Integer-Convertible+Objects]:
+  #
+  #    a = [:foo, :bar, :baz]
+  #    a.fetch_values(2, 0)   # => [:baz, :foo]
+  #    a.fetch_values(2.1, 0) # => [:baz, :foo]
+  #    a.fetch_values         # => []
+  #
+  # For a negative index, counts backwards from the end of the array:
+  #
+  #    a.fetch_values(-2, -1) # [:bar, :baz]
+  #
+  # When no block is given, raises an exception if any index is out of range.
+  #
+  # With a block given, for each index:
+  #
+  # - If the index is in range, uses an element of +self+ (as above).
+  # - Otherwise, calls the block with the index and uses the block's return value.
+  #
+  # Example:
+  #
+  #   a = [:foo, :bar, :baz]
+  #   a.fetch_values(1, 0, 42, 777) { |index| index.to_s }
+  #   # => [:bar, :foo, "42", "777"]
+  #
+  # Related: see {Methods for Fetching}[rdoc-ref:Array@Methods+for+Fetching].
+  def fetch_values(*indexes, &block)
+    indexes.map! { |i| fetch(i, &block) }
+    indexes
+  end
+
+  with_jit do
+    if Primitive.rb_builtin_basic_definition_p(:each)
+      undef :each
+
+      def each # :nodoc:
+        Primitive.attr! :inline_block, :c_trace, :without_interrupts
+
+        unless defined?(yield)
+          return Primitive.cexpr! 'SIZED_ENUMERATOR(self, 0, 0, ary_enum_length)'
+        end
+        i = 0
+        until Primitive.rb_jit_ary_at_end(i)
+          yield Primitive.rb_jit_ary_at(i)
+          i = Primitive.rb_jit_fixnum_inc(i)
+        end
+        self
+      end
+    end
+
+    if Primitive.rb_builtin_basic_definition_p(:map)
+      undef :map
+
+      def map # :nodoc:
+        Primitive.attr! :inline_block, :c_trace, :without_interrupts
+
+        unless defined?(yield)
+          return Primitive.cexpr! 'SIZED_ENUMERATOR(self, 0, 0, ary_enum_length)'
+        end
+
+        i = 0
+        result = Primitive.ary_sized_alloc
+        until Primitive.rb_jit_ary_at_end(i)
+          value = yield(Primitive.rb_jit_ary_at(i))
+          Primitive.rb_jit_ary_push(result, value)
+          i = Primitive.rb_jit_fixnum_inc(i)
+        end
+        result
+      end
+
+      if Primitive.rb_builtin_basic_definition_p(:collect)
+        undef :collect
+        alias collect map
+      end
+    end
+
+    if Primitive.rb_builtin_basic_definition_p(:select)
+      undef :select
+
+      def select # :nodoc:
+        Primitive.attr! :inline_block, :c_trace, :without_interrupts
+
+        unless defined?(yield)
+          return Primitive.cexpr! 'SIZED_ENUMERATOR(self, 0, 0, ary_enum_length)'
+        end
+
+        i = 0
+        result = Primitive.ary_sized_alloc
+        until Primitive.rb_jit_ary_at_end(i)
+          value = Primitive.rb_jit_ary_at(i)
+          if yield value
+            Primitive.rb_jit_ary_push(result, value)
+          end
+          i = Primitive.rb_jit_fixnum_inc(i)
+        end
+        result
+      end
+
+      if Primitive.rb_builtin_basic_definition_p(:filter)
+        undef :filter
+        alias filter select
+      end
+    end
+
+    if Primitive.rb_builtin_basic_definition_p(:find)
+      undef :find
+
+      def find(if_none_proc = nil) # :nodoc:
+        Primitive.attr! :inline_block, :c_trace, :without_interrupts
+
+        unless defined?(yield)
+          return Primitive.cexpr! 'SIZED_ENUMERATOR(self, 0, 0, ary_enum_length)'
+        end
+        i = 0
+        until Primitive.rb_jit_ary_at_end(i)
+          value = Primitive.rb_jit_ary_at(i)
+          return value if yield(value)
+          i = Primitive.rb_jit_fixnum_inc(i)
+        end
+        if_none_proc&.call
+      end
+    end
+  end
 end
diff --git a/ast.c b/ast.c
index c71b7b3987..1ddc2b5791 100644
--- a/ast.c
+++ b/ast.c
@@ -14,9 +14,10 @@
 
 static VALUE rb_mAST;
 static VALUE rb_cNode;
+static VALUE rb_cLocation;
 
 struct ASTNodeData {
-    rb_ast_t *ast;
+    VALUE ast_value;
     const NODE *node;
 };
 
@@ -24,14 +25,20 @@ static void
 node_gc_mark(void *ptr)
 {
     struct ASTNodeData *data = (struct ASTNodeData *)ptr;
-    rb_gc_mark((VALUE)data->ast);
+    rb_gc_mark(data->ast_value);
 }
 
 static size_t
 node_memsize(const void *ptr)
 {
     struct ASTNodeData *data = (struct ASTNodeData *)ptr;
-    return rb_ast_memsize(data->ast);
+    size_t size = sizeof(struct ASTNodeData);
+    if (data->ast_value) {
+        rb_ast_t *ast = rb_ruby_ast_data_get(data->ast_value);
+        size += rb_ast_memsize(ast);
+    }
+
+    return size;
 }
 
 static const rb_data_type_t rb_node_type = {
@@ -41,25 +48,51 @@ static const rb_data_type_t rb_node_type = {
     RUBY_TYPED_FREE_IMMEDIATELY,
 };
 
+struct ASTLocationData {
+    int first_lineno;
+    int first_column;
+    int last_lineno;
+    int last_column;
+};
+
+static void
+location_gc_mark(void *ptr)
+{
+}
+
+static size_t
+location_memsize(const void *ptr)
+{
+    return sizeof(struct ASTLocationData);
+}
+
+static const rb_data_type_t rb_location_type = {
+    "AST/location",
+    {location_gc_mark, RUBY_TYPED_DEFAULT_FREE, location_memsize,},
+    0, 0,
+    RUBY_TYPED_FREE_IMMEDIATELY,
+};
+
+
 static VALUE rb_ast_node_alloc(VALUE klass);
 
 static void
-setup_node(VALUE obj, rb_ast_t *ast, const NODE *node)
+setup_node(VALUE obj, VALUE ast_value, const NODE *node)
 {
     struct ASTNodeData *data;
 
     TypedData_Get_Struct(obj, struct ASTNodeData, &rb_node_type, data);
-    data->ast = ast;
+    data->ast_value = ast_value;
     data->node = node;
 }
 
 static VALUE
-ast_new_internal(rb_ast_t *ast, const NODE *node)
+ast_new_internal(VALUE ast_value, const NODE *node)
 {
     VALUE obj;
 
     obj = rb_ast_node_alloc(rb_cNode);
-    setup_node(obj, ast, node);
+    setup_node(obj, ast_value, node);
 
     return obj;
 }
@@ -74,14 +107,26 @@ ast_parse_new(void)
 }
 
 static VALUE
-ast_parse_done(rb_ast_t *ast)
+ast_parse_done(VALUE ast_value)
 {
+    rb_ast_t *ast = rb_ruby_ast_data_get(ast_value);
+
     if (!ast->body.root) {
         rb_ast_dispose(ast);
         rb_exc_raise(GET_EC()->errinfo);
     }
 
-    return ast_new_internal(ast, (NODE *)ast->body.root);
+    return ast_new_internal(ast_value, (NODE *)ast->body.root);
+}
+
+static VALUE
+setup_vparser(VALUE keep_script_lines, VALUE error_tolerant, VALUE keep_tokens)
+{
+    VALUE vparser = ast_parse_new();
+    if (RTEST(keep_script_lines)) rb_parser_set_script_lines(vparser);
+    if (RTEST(error_tolerant)) rb_parser_error_tolerant(vparser);
+    if (RTEST(keep_tokens)) rb_parser_keep_tokens(vparser);
+    return vparser;
 }
 
 static VALUE
@@ -93,15 +138,11 @@ ast_s_parse(rb_execution_context_t *ec, VALUE module, VALUE str, VALUE keep_scri
 static VALUE
 rb_ast_parse_str(VALUE str, VALUE keep_script_lines, VALUE error_tolerant, VALUE keep_tokens)
 {
-    rb_ast_t *ast = 0;
-
+    VALUE ast_value = Qnil;
     StringValue(str);
-    VALUE vparser = ast_parse_new();
-    if (RTEST(keep_script_lines)) rb_parser_set_script_lines(vparser, Qtrue);
-    if (RTEST(error_tolerant)) rb_parser_error_tolerant(vparser);
-    if (RTEST(keep_tokens)) rb_parser_keep_tokens(vparser);
-    ast = rb_parser_compile_string_path(vparser, Qnil, str, 1);
-    return ast_parse_done(ast);
+    VALUE vparser = setup_vparser(keep_script_lines, error_tolerant, keep_tokens);
+    ast_value = rb_parser_compile_string_path(vparser, Qnil, str, 1);
+    return ast_parse_done(ast_value);
 }
 
 static VALUE
@@ -114,49 +155,29 @@ static VALUE
 rb_ast_parse_file(VALUE path, VALUE keep_script_lines, VALUE error_tolerant, VALUE keep_tokens)
 {
     VALUE f;
-    rb_ast_t *ast = 0;
+    VALUE ast_value = Qnil;
     rb_encoding *enc = rb_utf8_encoding();
 
-    FilePathValue(path);
     f = rb_file_open_str(path, "r");
     rb_funcall(f, rb_intern("set_encoding"), 2, rb_enc_from_encoding(enc), rb_str_new_cstr("-"));
-    VALUE vparser = ast_parse_new();
-    if (RTEST(keep_script_lines)) rb_parser_set_script_lines(vparser, Qtrue);
-    if (RTEST(error_tolerant))  rb_parser_error_tolerant(vparser);
-    if (RTEST(keep_tokens))  rb_parser_keep_tokens(vparser);
-    ast = rb_parser_compile_file_path(vparser, Qnil, f, 1);
+    VALUE vparser = setup_vparser(keep_script_lines, error_tolerant, keep_tokens);
+    ast_value = rb_parser_compile_file_path(vparser, Qnil, f, 1);
     rb_io_close(f);
-    return ast_parse_done(ast);
-}
-
-static VALUE
-lex_array(VALUE array, int index)
-{
-    VALUE str = rb_ary_entry(array, index);
-    if (!NIL_P(str)) {
-        StringValue(str);
-        if (!rb_enc_asciicompat(rb_enc_get(str))) {
-            rb_raise(rb_eArgError, "invalid source encoding");
-        }
-    }
-    return str;
+    return ast_parse_done(ast_value);
 }
 
 static VALUE
 rb_ast_parse_array(VALUE array, VALUE keep_script_lines, VALUE error_tolerant, VALUE keep_tokens)
 {
-    rb_ast_t *ast = 0;
+    VALUE ast_value = Qnil;
 
     array = rb_check_array_type(array);
-    VALUE vparser = ast_parse_new();
-    if (RTEST(keep_script_lines)) rb_parser_set_script_lines(vparser, Qtrue);
-    if (RTEST(error_tolerant)) rb_parser_error_tolerant(vparser);
-    if (RTEST(keep_tokens)) rb_parser_keep_tokens(vparser);
-    ast = rb_parser_compile_generic(vparser, lex_array, Qnil, array, 1);
-    return ast_parse_done(ast);
+    VALUE vparser = setup_vparser(keep_script_lines, error_tolerant, keep_tokens);
+    ast_value = rb_parser_compile_array(vparser, Qnil, array, 1);
+    return ast_parse_done(ast_value);
 }
 
-static VALUE node_children(rb_ast_t*, const NODE*);
+static VALUE node_children(VALUE, const NODE*);
 
 static VALUE
 node_find(VALUE self, const int node_id)
@@ -168,7 +189,7 @@ node_find(VALUE self, const int node_id)
 
     if (nd_node_id(data->node) == node_id) return self;
 
-    ary = node_children(data->ast, data->node);
+    ary = node_children(data->ast_value, data->node);
 
     for (i = 0; i < RARRAY_LEN(ary); i++) {
         VALUE child = RARRAY_AREF(ary, i);
@@ -184,29 +205,6 @@ node_find(VALUE self, const int node_id)
 
 extern VALUE rb_e_script;
 
-VALUE
-rb_script_lines_for(VALUE path, bool add)
-{
-    VALUE hash, lines;
-    ID script_lines;
-    CONST_ID(script_lines, "SCRIPT_LINES__");
-    if (!rb_const_defined_at(rb_cObject, script_lines)) return Qnil;
-    hash = rb_const_get_at(rb_cObject, script_lines);
-    if (!RB_TYPE_P(hash, T_HASH)) return Qnil;
-    if (add) {
-        rb_hash_aset(hash, path, lines = rb_ary_new());
-    }
-    else if (!RB_TYPE_P((lines = rb_hash_lookup(hash, path)), T_ARRAY)) {
-        return Qnil;
-    }
-    return lines;
-}
-static VALUE
-script_lines(VALUE path)
-{
-    return rb_script_lines_for(path, false);
-}
-
 static VALUE
 node_id_for_backtrace_location(rb_execution_context_t *ec, VALUE module, VALUE location)
 {
@@ -254,6 +252,11 @@ ast_s_of(rb_execution_context_t *ec, VALUE module, VALUE body, VALUE keep_script
     if (!iseq) {
         return Qnil;
     }
+
+    if (ISEQ_BODY(iseq)->prism) {
+        rb_raise(rb_eRuntimeError, "cannot get AST for ISEQ compiled by prism");
+    }
+
     lines = ISEQ_BODY(iseq)->variable.script_lines;
 
     VALUE path = rb_iseq_path(iseq);
@@ -263,7 +266,7 @@ ast_s_of(rb_execution_context_t *ec, VALUE module, VALUE body, VALUE keep_script
         rb_raise(rb_eArgError, "cannot get AST for method defined in eval");
     }
 
-    if (!NIL_P(lines) || !NIL_P(lines = script_lines(path))) {
+    if (!NIL_P(lines)) {
         node = rb_ast_parse_array(lines, keep_script_lines, error_tolerant, keep_tokens);
     }
     else if (e_option) {
@@ -309,10 +312,10 @@ ast_node_node_id(rb_execution_context_t *ec, VALUE self)
     return INT2FIX(nd_node_id(data->node));
 }
 
-#define NEW_CHILD(ast, node) node ? ast_new_internal(ast, node) : Qnil
+#define NEW_CHILD(ast_value, node) (node ? ast_new_internal(ast_value, node) : Qnil)
 
 static VALUE
-rb_ary_new_from_node_args(rb_ast_t *ast, long n, ...)
+rb_ary_new_from_node_args(VALUE ast_value, long n, ...)
 {
     va_list ar;
     VALUE ary;
@@ -324,39 +327,57 @@ rb_ary_new_from_node_args(rb_ast_t *ast, long n, ...)
     for (i=0; i<n; i++) {
         NODE *node;
         node = va_arg(ar, NODE *);
-        rb_ary_push(ary, NEW_CHILD(ast, node));
+        rb_ary_push(ary, NEW_CHILD(ast_value, node));
     }
     va_end(ar);
     return ary;
 }
 
 static VALUE
-dump_block(rb_ast_t *ast, const struct RNode_BLOCK *node)
+dump_block(VALUE ast_value, const struct RNode_BLOCK *node)
 {
     VALUE ary = rb_ary_new();
     do {
-        rb_ary_push(ary, NEW_CHILD(ast, node->nd_head));
+        rb_ary_push(ary, NEW_CHILD(ast_value, node->nd_head));
     } while (node->nd_next &&
         nd_type_p(node->nd_next, NODE_BLOCK) &&
         (node = RNODE_BLOCK(node->nd_next), 1));
     if (node->nd_next) {
-        rb_ary_push(ary, NEW_CHILD(ast, node->nd_next));
+        rb_ary_push(ary, NEW_CHILD(ast_value, node->nd_next));
     }
 
     return ary;
 }
 
 static VALUE
-dump_array(rb_ast_t *ast, const struct RNode_LIST *node)
+dump_array(VALUE ast_value, const struct RNode_LIST *node)
 {
     VALUE ary = rb_ary_new();
-    rb_ary_push(ary, NEW_CHILD(ast, node->nd_head));
+    rb_ary_push(ary, NEW_CHILD(ast_value, node->nd_head));
 
     while (node->nd_next && nd_type_p(node->nd_next, NODE_LIST)) {
         node = RNODE_LIST(node->nd_next);
-        rb_ary_push(ary, NEW_CHILD(ast, node->nd_head));
+        rb_ary_push(ary, NEW_CHILD(ast_value, node->nd_head));
+    }
+    rb_ary_push(ary, NEW_CHILD(ast_value, node->nd_next));
+
+    return ary;
+}
+
+static VALUE
+dump_parser_array(VALUE ast_value, rb_parser_ary_t *p_ary)
+{
+    VALUE ary;
+
+    if (p_ary->data_type != PARSER_ARY_DATA_NODE) {
+        rb_bug("unexpected rb_parser_ary_data_type: %d", p_ary->data_type);
+    }
+
+    ary = rb_ary_new();
+
+    for (long i = 0; i < p_ary->len; i++) {
+        rb_ary_push(ary, NEW_CHILD(ast_value, p_ary->data[i]));
     }
-    rb_ary_push(ary, NEW_CHILD(ast, node->nd_next));
 
     return ary;
 }
@@ -378,155 +399,168 @@ no_name_rest(void)
 }
 
 static VALUE
-rest_arg(rb_ast_t *ast, const NODE *rest_arg)
+rest_arg(VALUE ast_value, const NODE *rest_arg)
 {
-    return NODE_NAMED_REST_P(rest_arg) ? NEW_CHILD(ast, rest_arg) : no_name_rest();
+    return NODE_NAMED_REST_P(rest_arg) ? NEW_CHILD(ast_value, rest_arg) : no_name_rest();
+}
+
+static ID
+node_colon_name(const NODE *node)
+{
+    switch (nd_type(node)) {
+      case NODE_COLON2:
+        return RNODE_COLON2(node)->nd_mid;
+      case NODE_COLON3:
+        return RNODE_COLON3(node)->nd_mid;
+      default:
+        rb_bug("unexpected node: %s", ruby_node_name(nd_type(node)));
+    }
 }
 
 static VALUE
-node_children(rb_ast_t *ast, const NODE *node)
+node_children(VALUE ast_value, const NODE *node)
 {
     char name[sizeof("$") + DECIMAL_SIZE_OF(long)];
 
     enum node_type type = nd_type(node);
     switch (type) {
       case NODE_BLOCK:
-        return dump_block(ast, RNODE_BLOCK(node));
+        return dump_block(ast_value, RNODE_BLOCK(node));
       case NODE_IF:
-        return rb_ary_new_from_node_args(ast, 3, RNODE_IF(node)->nd_cond, RNODE_IF(node)->nd_body, RNODE_IF(node)->nd_else);
+        return rb_ary_new_from_node_args(ast_value, 3, RNODE_IF(node)->nd_cond, RNODE_IF(node)->nd_body, RNODE_IF(node)->nd_else);
       case NODE_UNLESS:
-        return rb_ary_new_from_node_args(ast, 3, RNODE_UNLESS(node)->nd_cond, RNODE_UNLESS(node)->nd_body, RNODE_UNLESS(node)->nd_else);
+        return rb_ary_new_from_node_args(ast_value, 3, RNODE_UNLESS(node)->nd_cond, RNODE_UNLESS(node)->nd_body, RNODE_UNLESS(node)->nd_else);
       case NODE_CASE:
-        return rb_ary_new_from_node_args(ast, 2, RNODE_CASE(node)->nd_head, RNODE_CASE(node)->nd_body);
+        return rb_ary_new_from_node_args(ast_value, 2, RNODE_CASE(node)->nd_head, RNODE_CASE(node)->nd_body);
       case NODE_CASE2:
-        return rb_ary_new_from_node_args(ast, 2, RNODE_CASE2(node)->nd_head, RNODE_CASE2(node)->nd_body);
+        return rb_ary_new_from_node_args(ast_value, 2, RNODE_CASE2(node)->nd_head, RNODE_CASE2(node)->nd_body);
       case NODE_CASE3:
-        return rb_ary_new_from_node_args(ast, 2, RNODE_CASE3(node)->nd_head, RNODE_CASE3(node)->nd_body);
+        return rb_ary_new_from_node_args(ast_value, 2, RNODE_CASE3(node)->nd_head, RNODE_CASE3(node)->nd_body);
       case NODE_WHEN:
-        return rb_ary_new_from_node_args(ast, 3, RNODE_WHEN(node)->nd_head, RNODE_WHEN(node)->nd_body, RNODE_WHEN(node)->nd_next);
+        return rb_ary_new_from_node_args(ast_value, 3, RNODE_WHEN(node)->nd_head, RNODE_WHEN(node)->nd_body, RNODE_WHEN(node)->nd_next);
       case NODE_IN:
-        return rb_ary_new_from_node_args(ast, 3, RNODE_IN(node)->nd_head, RNODE_IN(node)->nd_body, RNODE_IN(node)->nd_next);
+        return rb_ary_new_from_node_args(ast_value, 3, RNODE_IN(node)->nd_head, RNODE_IN(node)->nd_body, RNODE_IN(node)->nd_next);
       case NODE_WHILE:
       case NODE_UNTIL:
-        return rb_ary_push(rb_ary_new_from_node_args(ast, 2, RNODE_WHILE(node)->nd_cond, RNODE_WHILE(node)->nd_body),
+        return rb_ary_push(rb_ary_new_from_node_args(ast_value, 2, RNODE_WHILE(node)->nd_cond, RNODE_WHILE(node)->nd_body),
                            RBOOL(RNODE_WHILE(node)->nd_state));
       case NODE_ITER:
       case NODE_FOR:
-        return rb_ary_new_from_node_args(ast, 2, RNODE_ITER(node)->nd_iter, RNODE_ITER(node)->nd_body);
+        return rb_ary_new_from_node_args(ast_value, 2, RNODE_ITER(node)->nd_iter, RNODE_ITER(node)->nd_body);
       case NODE_FOR_MASGN:
-        return rb_ary_new_from_node_args(ast, 1, RNODE_FOR_MASGN(node)->nd_var);
+        return rb_ary_new_from_node_args(ast_value, 1, RNODE_FOR_MASGN(node)->nd_var);
       case NODE_BREAK:
-        return rb_ary_new_from_node_args(ast, 1, RNODE_BREAK(node)->nd_stts);
+        return rb_ary_new_from_node_args(ast_value, 1, RNODE_BREAK(node)->nd_stts);
       case NODE_NEXT:
-        return rb_ary_new_from_node_args(ast, 1, RNODE_NEXT(node)->nd_stts);
+        return rb_ary_new_from_node_args(ast_value, 1, RNODE_NEXT(node)->nd_stts);
       case NODE_RETURN:
-        return rb_ary_new_from_node_args(ast, 1, RNODE_RETURN(node)->nd_stts);
+        return rb_ary_new_from_node_args(ast_value, 1, RNODE_RETURN(node)->nd_stts);
       case NODE_REDO:
-        return rb_ary_new_from_node_args(ast, 0);
+        return rb_ary_new_from_node_args(ast_value, 0);
       case NODE_RETRY:
-        return rb_ary_new_from_node_args(ast, 0);
+        return rb_ary_new_from_node_args(ast_value, 0);
       case NODE_BEGIN:
-        return rb_ary_new_from_node_args(ast, 1, RNODE_BEGIN(node)->nd_body);
+        return rb_ary_new_from_node_args(ast_value, 1, RNODE_BEGIN(node)->nd_body);
       case NODE_RESCUE:
-        return rb_ary_new_from_node_args(ast, 3, RNODE_RESCUE(node)->nd_head, RNODE_RESCUE(node)->nd_resq, RNODE_RESCUE(node)->nd_else);
+        return rb_ary_new_from_node_args(ast_value, 3, RNODE_RESCUE(node)->nd_head, RNODE_RESCUE(node)->nd_resq, RNODE_RESCUE(node)->nd_else);
       case NODE_RESBODY:
-        return rb_ary_new_from_node_args(ast, 3, RNODE_RESBODY(node)->nd_args, RNODE_RESBODY(node)->nd_body, RNODE_RESBODY(node)->nd_head);
+        return rb_ary_new_from_node_args(ast_value, 4, RNODE_RESBODY(node)->nd_args, RNODE_RESBODY(node)->nd_exc_var, RNODE_RESBODY(node)->nd_body, RNODE_RESBODY(node)->nd_next);
       case NODE_ENSURE:
-        return rb_ary_new_from_node_args(ast, 2, RNODE_ENSURE(node)->nd_head, RNODE_ENSURE(node)->nd_ensr);
+        return rb_ary_new_from_node_args(ast_value, 2, RNODE_ENSURE(node)->nd_head, RNODE_ENSURE(node)->nd_ensr);
       case NODE_AND:
       case NODE_OR:
         {
             VALUE ary = rb_ary_new();
 
             while (1) {
-                rb_ary_push(ary, NEW_CHILD(ast, RNODE_AND(node)->nd_1st));
+                rb_ary_push(ary, NEW_CHILD(ast_value, RNODE_AND(node)->nd_1st));
                 if (!RNODE_AND(node)->nd_2nd || !nd_type_p(RNODE_AND(node)->nd_2nd, type))
                     break;
                 node = RNODE_AND(node)->nd_2nd;
             }
-            rb_ary_push(ary, NEW_CHILD(ast, RNODE_AND(node)->nd_2nd));
+            rb_ary_push(ary, NEW_CHILD(ast_value, RNODE_AND(node)->nd_2nd));
             return ary;
         }
       case NODE_MASGN:
         if (NODE_NAMED_REST_P(RNODE_MASGN(node)->nd_args)) {
-            return rb_ary_new_from_node_args(ast, 3, RNODE_MASGN(node)->nd_value, RNODE_MASGN(node)->nd_head, RNODE_MASGN(node)->nd_args);
+            return rb_ary_new_from_node_args(ast_value, 3, RNODE_MASGN(node)->nd_value, RNODE_MASGN(node)->nd_head, RNODE_MASGN(node)->nd_args);
         }
         else {
-            return rb_ary_new_from_args(3, NEW_CHILD(ast, RNODE_MASGN(node)->nd_value),
-                                        NEW_CHILD(ast, RNODE_MASGN(node)->nd_head),
+            return rb_ary_new_from_args(3, NEW_CHILD(ast_value, RNODE_MASGN(node)->nd_value),
+                                        NEW_CHILD(ast_value, RNODE_MASGN(node)->nd_head),
                                         no_name_rest());
         }
       case NODE_LASGN:
         if (NODE_REQUIRED_KEYWORD_P(RNODE_LASGN(node)->nd_value)) {
             return rb_ary_new_from_args(2, var_name(RNODE_LASGN(node)->nd_vid), ID2SYM(rb_intern("NODE_SPECIAL_REQUIRED_KEYWORD")));
         }
-        return rb_ary_new_from_args(2, var_name(RNODE_LASGN(node)->nd_vid), NEW_CHILD(ast, RNODE_LASGN(node)->nd_value));
+        return rb_ary_new_from_args(2, var_name(RNODE_LASGN(node)->nd_vid), NEW_CHILD(ast_value, RNODE_LASGN(node)->nd_value));
       case NODE_DASGN:
         if (NODE_REQUIRED_KEYWORD_P(RNODE_DASGN(node)->nd_value)) {
             return rb_ary_new_from_args(2, var_name(RNODE_DASGN(node)->nd_vid), ID2SYM(rb_intern("NODE_SPECIAL_REQUIRED_KEYWORD")));
         }
-        return rb_ary_new_from_args(2, var_name(RNODE_DASGN(node)->nd_vid), NEW_CHILD(ast, RNODE_DASGN(node)->nd_value));
+        return rb_ary_new_from_args(2, var_name(RNODE_DASGN(node)->nd_vid), NEW_CHILD(ast_value, RNODE_DASGN(node)->nd_value));
       case NODE_IASGN:
-        return rb_ary_new_from_args(2, var_name(RNODE_IASGN(node)->nd_vid), NEW_CHILD(ast, RNODE_IASGN(node)->nd_value));
+        return rb_ary_new_from_args(2, var_name(RNODE_IASGN(node)->nd_vid), NEW_CHILD(ast_value, RNODE_IASGN(node)->nd_value));
       case NODE_CVASGN:
-        return rb_ary_new_from_args(2, var_name(RNODE_CVASGN(node)->nd_vid), NEW_CHILD(ast, RNODE_CVASGN(node)->nd_value));
+        return rb_ary_new_from_args(2, var_name(RNODE_CVASGN(node)->nd_vid), NEW_CHILD(ast_value, RNODE_CVASGN(node)->nd_value));
       case NODE_GASGN:
-        return rb_ary_new_from_args(2, var_name(RNODE_GASGN(node)->nd_vid), NEW_CHILD(ast, RNODE_GASGN(node)->nd_value));
+        return rb_ary_new_from_args(2, var_name(RNODE_GASGN(node)->nd_vid), NEW_CHILD(ast_value, RNODE_GASGN(node)->nd_value));
       case NODE_CDECL:
         if (RNODE_CDECL(node)->nd_vid) {
-            return rb_ary_new_from_args(2, ID2SYM(RNODE_CDECL(node)->nd_vid), NEW_CHILD(ast, RNODE_CDECL(node)->nd_value));
+            return rb_ary_new_from_args(2, ID2SYM(RNODE_CDECL(node)->nd_vid), NEW_CHILD(ast_value, RNODE_CDECL(node)->nd_value));
         }
-        return rb_ary_new_from_args(3, NEW_CHILD(ast, RNODE_CDECL(node)->nd_else), ID2SYM(RNODE_COLON2(RNODE_CDECL(node)->nd_else)->nd_mid), NEW_CHILD(ast, RNODE_CDECL(node)->nd_value));
+        return rb_ary_new_from_args(3, NEW_CHILD(ast_value, RNODE_CDECL(node)->nd_else), ID2SYM(node_colon_name(RNODE_CDECL(node)->nd_else)), NEW_CHILD(ast_value, RNODE_CDECL(node)->nd_value));
       case NODE_OP_ASGN1:
-        return rb_ary_new_from_args(4, NEW_CHILD(ast, RNODE_OP_ASGN1(node)->nd_recv),
+        return rb_ary_new_from_args(4, NEW_CHILD(ast_value, RNODE_OP_ASGN1(node)->nd_recv),
                                     ID2SYM(RNODE_OP_ASGN1(node)->nd_mid),
-                                    NEW_CHILD(ast, RNODE_OP_ASGN1(node)->nd_index),
-                                    NEW_CHILD(ast, RNODE_OP_ASGN1(node)->nd_rvalue));
+                                    NEW_CHILD(ast_value, RNODE_OP_ASGN1(node)->nd_index),
+                                    NEW_CHILD(ast_value, RNODE_OP_ASGN1(node)->nd_rvalue));
       case NODE_OP_ASGN2:
-        return rb_ary_new_from_args(5, NEW_CHILD(ast, RNODE_OP_ASGN2(node)->nd_recv),
+        return rb_ary_new_from_args(5, NEW_CHILD(ast_value, RNODE_OP_ASGN2(node)->nd_recv),
                                     RBOOL(RNODE_OP_ASGN2(node)->nd_aid),
                                     ID2SYM(RNODE_OP_ASGN2(node)->nd_vid),
                                     ID2SYM(RNODE_OP_ASGN2(node)->nd_mid),
-                                    NEW_CHILD(ast, RNODE_OP_ASGN2(node)->nd_value));
+                                    NEW_CHILD(ast_value, RNODE_OP_ASGN2(node)->nd_value));
       case NODE_OP_ASGN_AND:
-        return rb_ary_new_from_args(3, NEW_CHILD(ast, RNODE_OP_ASGN_AND(node)->nd_head), ID2SYM(idANDOP),
-                                    NEW_CHILD(ast, RNODE_OP_ASGN_AND(node)->nd_value));
+        return rb_ary_new_from_args(3, NEW_CHILD(ast_value, RNODE_OP_ASGN_AND(node)->nd_head), ID2SYM(idANDOP),
+                                    NEW_CHILD(ast_value, RNODE_OP_ASGN_AND(node)->nd_value));
       case NODE_OP_ASGN_OR:
-        return rb_ary_new_from_args(3, NEW_CHILD(ast, RNODE_OP_ASGN_OR(node)->nd_head), ID2SYM(idOROP),
-                                    NEW_CHILD(ast, RNODE_OP_ASGN_OR(node)->nd_value));
+        return rb_ary_new_from_args(3, NEW_CHILD(ast_value, RNODE_OP_ASGN_OR(node)->nd_head), ID2SYM(idOROP),
+                                    NEW_CHILD(ast_value, RNODE_OP_ASGN_OR(node)->nd_value));
       case NODE_OP_CDECL:
-        return rb_ary_new_from_args(3, NEW_CHILD(ast, RNODE_OP_CDECL(node)->nd_head),
+        return rb_ary_new_from_args(3, NEW_CHILD(ast_value, RNODE_OP_CDECL(node)->nd_head),
                                     ID2SYM(RNODE_OP_CDECL(node)->nd_aid),
-                                    NEW_CHILD(ast, RNODE_OP_CDECL(node)->nd_value));
+                                    NEW_CHILD(ast_value, RNODE_OP_CDECL(node)->nd_value));
       case NODE_CALL:
-        return rb_ary_new_from_args(3, NEW_CHILD(ast, RNODE_CALL(node)->nd_recv),
+        return rb_ary_new_from_args(3, NEW_CHILD(ast_value, RNODE_CALL(node)->nd_recv),
                                     ID2SYM(RNODE_CALL(node)->nd_mid),
-                                    NEW_CHILD(ast, RNODE_CALL(node)->nd_args));
+                                    NEW_CHILD(ast_value, RNODE_CALL(node)->nd_args));
       case NODE_OPCALL:
-        return rb_ary_new_from_args(3, NEW_CHILD(ast, RNODE_OPCALL(node)->nd_recv),
+        return rb_ary_new_from_args(3, NEW_CHILD(ast_value, RNODE_OPCALL(node)->nd_recv),
                                     ID2SYM(RNODE_OPCALL(node)->nd_mid),
-                                    NEW_CHILD(ast, RNODE_OPCALL(node)->nd_args));
+                                    NEW_CHILD(ast_value, RNODE_OPCALL(node)->nd_args));
       case NODE_QCALL:
-        return rb_ary_new_from_args(3, NEW_CHILD(ast, RNODE_QCALL(node)->nd_recv),
+        return rb_ary_new_from_args(3, NEW_CHILD(ast_value, RNODE_QCALL(node)->nd_recv),
                                     ID2SYM(RNODE_QCALL(node)->nd_mid),
-                                    NEW_CHILD(ast, RNODE_QCALL(node)->nd_args));
+                                    NEW_CHILD(ast_value, RNODE_QCALL(node)->nd_args));
       case NODE_FCALL:
         return rb_ary_new_from_args(2, ID2SYM(RNODE_FCALL(node)->nd_mid),
-                                    NEW_CHILD(ast, RNODE_FCALL(node)->nd_args));
+                                    NEW_CHILD(ast_value, RNODE_FCALL(node)->nd_args));
       case NODE_VCALL:
         return rb_ary_new_from_args(1, ID2SYM(RNODE_VCALL(node)->nd_mid));
       case NODE_SUPER:
-        return rb_ary_new_from_node_args(ast, 1, RNODE_SUPER(node)->nd_args);
+        return rb_ary_new_from_node_args(ast_value, 1, RNODE_SUPER(node)->nd_args);
       case NODE_ZSUPER:
-        return rb_ary_new_from_node_args(ast, 0);
+        return rb_ary_new_from_node_args(ast_value, 0);
       case NODE_LIST:
-        return dump_array(ast, RNODE_LIST(node));
+        return dump_array(ast_value, RNODE_LIST(node));
       case NODE_ZLIST:
-        return rb_ary_new_from_node_args(ast, 0);
+        return rb_ary_new_from_node_args(ast_value, 0);
       case NODE_HASH:
-        return rb_ary_new_from_node_args(ast, 1, RNODE_HASH(node)->nd_head);
+        return rb_ary_new_from_node_args(ast_value, 1, RNODE_HASH(node)->nd_head);
       case NODE_YIELD:
-        return rb_ary_new_from_node_args(ast, 1, RNODE_YIELD(node)->nd_head);
+        return rb_ary_new_from_node_args(ast_value, 1, RNODE_YIELD(node)->nd_head);
       case NODE_LVAR:
         return rb_ary_new_from_args(1, var_name(RNODE_LVAR(node)->nd_vid));
       case NODE_DVAR:
@@ -547,20 +581,30 @@ node_children(rb_ast_t *ast, const NODE *node)
         name[1] = (char)RNODE_BACK_REF(node)->nd_nth;
         name[2] = '\0';
         return rb_ary_new_from_args(1, ID2SYM(rb_intern(name)));
+      case NODE_MATCH:
+        return rb_ary_new_from_args(1, rb_node_regx_string_val(node));
       case NODE_MATCH2:
         if (RNODE_MATCH2(node)->nd_args) {
-            return rb_ary_new_from_node_args(ast, 3, RNODE_MATCH2(node)->nd_recv, RNODE_MATCH2(node)->nd_value, RNODE_MATCH2(node)->nd_args);
+            return rb_ary_new_from_node_args(ast_value, 3, RNODE_MATCH2(node)->nd_recv, RNODE_MATCH2(node)->nd_value, RNODE_MATCH2(node)->nd_args);
         }
-        return rb_ary_new_from_node_args(ast, 2, RNODE_MATCH2(node)->nd_recv, RNODE_MATCH2(node)->nd_value);
+        return rb_ary_new_from_node_args(ast_value, 2, RNODE_MATCH2(node)->nd_recv, RNODE_MATCH2(node)->nd_value);
       case NODE_MATCH3:
-        return rb_ary_new_from_node_args(ast, 2, RNODE_MATCH3(node)->nd_recv, RNODE_MATCH3(node)->nd_value);
-      case NODE_MATCH:
-      case NODE_LIT:
+        return rb_ary_new_from_node_args(ast_value, 2, RNODE_MATCH3(node)->nd_recv, RNODE_MATCH3(node)->nd_value);
       case NODE_STR:
       case NODE_XSTR:
-        return rb_ary_new_from_args(1, RNODE_LIT(node)->nd_lit);
+        return rb_ary_new_from_args(1, rb_node_str_string_val(node));
+      case NODE_INTEGER:
+        return rb_ary_new_from_args(1, rb_node_integer_literal_val(node));
+      case NODE_FLOAT:
+        return rb_ary_new_from_args(1, rb_node_float_literal_val(node));
+      case NODE_RATIONAL:
+        return rb_ary_new_from_args(1, rb_node_rational_literal_val(node));
+      case NODE_IMAGINARY:
+        return rb_ary_new_from_args(1, rb_node_imaginary_literal_val(node));
+      case NODE_REGX:
+        return rb_ary_new_from_args(1, rb_node_regx_string_val(node));
       case NODE_ONCE:
-        return rb_ary_new_from_node_args(ast, 1, RNODE_ONCE(node)->nd_body);
+        return rb_ary_new_from_node_args(ast_value, 1, RNODE_ONCE(node)->nd_body);
       case NODE_DSTR:
       case NODE_DXSTR:
       case NODE_DREGX:
@@ -569,90 +613,92 @@ node_children(rb_ast_t *ast, const NODE *node)
             struct RNode_LIST *n = RNODE_DSTR(node)->nd_next;
             VALUE head = Qnil, next = Qnil;
             if (n) {
-                head = NEW_CHILD(ast, n->nd_head);
-                next = NEW_CHILD(ast, n->nd_next);
+                head = NEW_CHILD(ast_value, n->nd_head);
+                next = NEW_CHILD(ast_value, n->nd_next);
             }
-            return rb_ary_new_from_args(3, RNODE_DSTR(node)->nd_lit, head, next);
+            return rb_ary_new_from_args(3, rb_node_dstr_string_val(node), head, next);
         }
+      case NODE_SYM:
+        return rb_ary_new_from_args(1, rb_node_sym_string_val(node));
       case NODE_EVSTR:
-        return rb_ary_new_from_node_args(ast, 1, RNODE_EVSTR(node)->nd_body);
+        return rb_ary_new_from_node_args(ast_value, 1, RNODE_EVSTR(node)->nd_body);
       case NODE_ARGSCAT:
-        return rb_ary_new_from_node_args(ast, 2, RNODE_ARGSCAT(node)->nd_head, RNODE_ARGSCAT(node)->nd_body);
+        return rb_ary_new_from_node_args(ast_value, 2, RNODE_ARGSCAT(node)->nd_head, RNODE_ARGSCAT(node)->nd_body);
       case NODE_ARGSPUSH:
-        return rb_ary_new_from_node_args(ast, 2, RNODE_ARGSPUSH(node)->nd_head, RNODE_ARGSPUSH(node)->nd_body);
+        return rb_ary_new_from_node_args(ast_value, 2, RNODE_ARGSPUSH(node)->nd_head, RNODE_ARGSPUSH(node)->nd_body);
       case NODE_SPLAT:
-        return rb_ary_new_from_node_args(ast, 1, RNODE_SPLAT(node)->nd_head);
+        return rb_ary_new_from_node_args(ast_value, 1, RNODE_SPLAT(node)->nd_head);
       case NODE_BLOCK_PASS:
-        return rb_ary_new_from_node_args(ast, 2, RNODE_BLOCK_PASS(node)->nd_head, RNODE_BLOCK_PASS(node)->nd_body);
+        return rb_ary_new_from_node_args(ast_value, 2, RNODE_BLOCK_PASS(node)->nd_head, RNODE_BLOCK_PASS(node)->nd_body);
       case NODE_DEFN:
-        return rb_ary_new_from_args(2, ID2SYM(RNODE_DEFN(node)->nd_mid), NEW_CHILD(ast, RNODE_DEFN(node)->nd_defn));
+        return rb_ary_new_from_args(2, ID2SYM(RNODE_DEFN(node)->nd_mid), NEW_CHILD(ast_value, RNODE_DEFN(node)->nd_defn));
       case NODE_DEFS:
-        return rb_ary_new_from_args(3, NEW_CHILD(ast, RNODE_DEFS(node)->nd_recv), ID2SYM(RNODE_DEFS(node)->nd_mid), NEW_CHILD(ast, RNODE_DEFS(node)->nd_defn));
+        return rb_ary_new_from_args(3, NEW_CHILD(ast_value, RNODE_DEFS(node)->nd_recv), ID2SYM(RNODE_DEFS(node)->nd_mid), NEW_CHILD(ast_value, RNODE_DEFS(node)->nd_defn));
       case NODE_ALIAS:
-        return rb_ary_new_from_node_args(ast, 2, RNODE_ALIAS(node)->nd_1st, RNODE_ALIAS(node)->nd_2nd);
+        return rb_ary_new_from_node_args(ast_value, 2, RNODE_ALIAS(node)->nd_1st, RNODE_ALIAS(node)->nd_2nd);
       case NODE_VALIAS:
         return rb_ary_new_from_args(2, ID2SYM(RNODE_VALIAS(node)->nd_alias), ID2SYM(RNODE_VALIAS(node)->nd_orig));
       case NODE_UNDEF:
-        return rb_ary_new_from_node_args(ast, 1, RNODE_UNDEF(node)->nd_undef);
+        return rb_ary_new_from_args(1, dump_parser_array(ast_value, RNODE_UNDEF(node)->nd_undefs));
       case NODE_CLASS:
-        return rb_ary_new_from_node_args(ast, 3, RNODE_CLASS(node)->nd_cpath, RNODE_CLASS(node)->nd_super, RNODE_CLASS(node)->nd_body);
+        return rb_ary_new_from_node_args(ast_value, 3, RNODE_CLASS(node)->nd_cpath, RNODE_CLASS(node)->nd_super, RNODE_CLASS(node)->nd_body);
       case NODE_MODULE:
-        return rb_ary_new_from_node_args(ast, 2, RNODE_MODULE(node)->nd_cpath, RNODE_MODULE(node)->nd_body);
+        return rb_ary_new_from_node_args(ast_value, 2, RNODE_MODULE(node)->nd_cpath, RNODE_MODULE(node)->nd_body);
       case NODE_SCLASS:
-        return rb_ary_new_from_node_args(ast, 2, RNODE_SCLASS(node)->nd_recv, RNODE_SCLASS(node)->nd_body);
+        return rb_ary_new_from_node_args(ast_value, 2, RNODE_SCLASS(node)->nd_recv, RNODE_SCLASS(node)->nd_body);
       case NODE_COLON2:
-        return rb_ary_new_from_args(2, NEW_CHILD(ast, RNODE_COLON2(node)->nd_head), ID2SYM(RNODE_COLON2(node)->nd_mid));
+        return rb_ary_new_from_args(2, NEW_CHILD(ast_value, RNODE_COLON2(node)->nd_head), ID2SYM(RNODE_COLON2(node)->nd_mid));
       case NODE_COLON3:
         return rb_ary_new_from_args(1, ID2SYM(RNODE_COLON3(node)->nd_mid));
       case NODE_DOT2:
       case NODE_DOT3:
       case NODE_FLIP2:
       case NODE_FLIP3:
-        return rb_ary_new_from_node_args(ast, 2, RNODE_DOT2(node)->nd_beg, RNODE_DOT2(node)->nd_end);
+        return rb_ary_new_from_node_args(ast_value, 2, RNODE_DOT2(node)->nd_beg, RNODE_DOT2(node)->nd_end);
       case NODE_SELF:
-        return rb_ary_new_from_node_args(ast, 0);
+        return rb_ary_new_from_node_args(ast_value, 0);
       case NODE_NIL:
-        return rb_ary_new_from_node_args(ast, 0);
+        return rb_ary_new_from_node_args(ast_value, 0);
       case NODE_TRUE:
-        return rb_ary_new_from_node_args(ast, 0);
+        return rb_ary_new_from_node_args(ast_value, 0);
       case NODE_FALSE:
-        return rb_ary_new_from_node_args(ast, 0);
+        return rb_ary_new_from_node_args(ast_value, 0);
       case NODE_ERRINFO:
-        return rb_ary_new_from_node_args(ast, 0);
+        return rb_ary_new_from_node_args(ast_value, 0);
       case NODE_DEFINED:
-        return rb_ary_new_from_node_args(ast, 1, RNODE_DEFINED(node)->nd_head);
+        return rb_ary_new_from_node_args(ast_value, 1, RNODE_DEFINED(node)->nd_head);
       case NODE_POSTEXE:
-        return rb_ary_new_from_node_args(ast, 1, RNODE_POSTEXE(node)->nd_body);
+        return rb_ary_new_from_node_args(ast_value, 1, RNODE_POSTEXE(node)->nd_body);
       case NODE_ATTRASGN:
-        return rb_ary_new_from_args(3, NEW_CHILD(ast, RNODE_ATTRASGN(node)->nd_recv), ID2SYM(RNODE_ATTRASGN(node)->nd_mid), NEW_CHILD(ast, RNODE_ATTRASGN(node)->nd_args));
+        return rb_ary_new_from_args(3, NEW_CHILD(ast_value, RNODE_ATTRASGN(node)->nd_recv), ID2SYM(RNODE_ATTRASGN(node)->nd_mid), NEW_CHILD(ast_value, RNODE_ATTRASGN(node)->nd_args));
       case NODE_LAMBDA:
-        return rb_ary_new_from_node_args(ast, 1, RNODE_LAMBDA(node)->nd_body);
+        return rb_ary_new_from_node_args(ast_value, 1, RNODE_LAMBDA(node)->nd_body);
       case NODE_OPT_ARG:
-        return rb_ary_new_from_node_args(ast, 2, RNODE_OPT_ARG(node)->nd_body, RNODE_OPT_ARG(node)->nd_next);
+        return rb_ary_new_from_node_args(ast_value, 2, RNODE_OPT_ARG(node)->nd_body, RNODE_OPT_ARG(node)->nd_next);
       case NODE_KW_ARG:
-        return rb_ary_new_from_node_args(ast, 2, RNODE_KW_ARG(node)->nd_body, RNODE_KW_ARG(node)->nd_next);
+        return rb_ary_new_from_node_args(ast_value, 2, RNODE_KW_ARG(node)->nd_body, RNODE_KW_ARG(node)->nd_next);
       case NODE_POSTARG:
         if (NODE_NAMED_REST_P(RNODE_POSTARG(node)->nd_1st)) {
-            return rb_ary_new_from_node_args(ast, 2, RNODE_POSTARG(node)->nd_1st, RNODE_POSTARG(node)->nd_2nd);
+            return rb_ary_new_from_node_args(ast_value, 2, RNODE_POSTARG(node)->nd_1st, RNODE_POSTARG(node)->nd_2nd);
         }
         return rb_ary_new_from_args(2, no_name_rest(),
-                                    NEW_CHILD(ast, RNODE_POSTARG(node)->nd_2nd));
+                                    NEW_CHILD(ast_value, RNODE_POSTARG(node)->nd_2nd));
       case NODE_ARGS:
         {
-            struct rb_args_info *ainfo = RNODE_ARGS(node)->nd_ainfo;
+            struct rb_args_info *ainfo = &RNODE_ARGS(node)->nd_ainfo;
             return rb_ary_new_from_args(10,
                                         INT2NUM(ainfo->pre_args_num),
-                                        NEW_CHILD(ast, ainfo->pre_init),
-                                        NEW_CHILD(ast, (NODE *)ainfo->opt_args),
+                                        NEW_CHILD(ast_value, ainfo->pre_init),
+                                        NEW_CHILD(ast_value, (NODE *)ainfo->opt_args),
                                         var_name(ainfo->first_post_arg),
                                         INT2NUM(ainfo->post_args_num),
-                                        NEW_CHILD(ast, ainfo->post_init),
+                                        NEW_CHILD(ast_value, ainfo->post_init),
                                         (ainfo->rest_arg == NODE_SPECIAL_EXCESSIVE_COMMA
                                             ? ID2SYM(rb_intern("NODE_SPECIAL_EXCESSIVE_COMMA"))
                                             : var_name(ainfo->rest_arg)),
-                                        (ainfo->no_kwarg ? Qfalse : NEW_CHILD(ast, (NODE *)ainfo->kw_args)),
-                                        (ainfo->no_kwarg ? Qfalse : NEW_CHILD(ast, ainfo->kw_rest_arg)),
-                                        var_name(ainfo->block_arg));
+                                        (ainfo->no_kwarg ? Qfalse : NEW_CHILD(ast_value, (NODE *)ainfo->kw_args)),
+                                        (ainfo->no_kwarg ? Qfalse : NEW_CHILD(ast_value, ainfo->kw_rest_arg)),
+                                        (ainfo->no_blockarg ? Qfalse : var_name(ainfo->block_arg)));
         }
       case NODE_SCOPE:
         {
@@ -662,42 +708,46 @@ node_children(rb_ast_t *ast, const NODE *node)
             for (i = 0; i < size; i++) {
                 rb_ary_push(locals, var_name(tbl->ids[i]));
             }
-            return rb_ary_new_from_args(3, locals, NEW_CHILD(ast, (NODE *)RNODE_SCOPE(node)->nd_args), NEW_CHILD(ast, RNODE_SCOPE(node)->nd_body));
+            return rb_ary_new_from_args(3, locals, NEW_CHILD(ast_value, (NODE *)RNODE_SCOPE(node)->nd_args), NEW_CHILD(ast_value, RNODE_SCOPE(node)->nd_body));
         }
       case NODE_ARYPTN:
         {
-            VALUE rest = rest_arg(ast, RNODE_ARYPTN(node)->rest_arg);
+            VALUE rest = rest_arg(ast_value, RNODE_ARYPTN(node)->rest_arg);
             return rb_ary_new_from_args(4,
-                                        NEW_CHILD(ast, RNODE_ARYPTN(node)->nd_pconst),
-                                        NEW_CHILD(ast, RNODE_ARYPTN(node)->pre_args),
+                                        NEW_CHILD(ast_value, RNODE_ARYPTN(node)->nd_pconst),
+                                        NEW_CHILD(ast_value, RNODE_ARYPTN(node)->pre_args),
                                         rest,
-                                        NEW_CHILD(ast, RNODE_ARYPTN(node)->post_args));
+                                        NEW_CHILD(ast_value, RNODE_ARYPTN(node)->post_args));
         }
       case NODE_FNDPTN:
         {
-            VALUE pre_rest = rest_arg(ast, RNODE_FNDPTN(node)->pre_rest_arg);
-            VALUE post_rest = rest_arg(ast, RNODE_FNDPTN(node)->post_rest_arg);
+            VALUE pre_rest = rest_arg(ast_value, RNODE_FNDPTN(node)->pre_rest_arg);
+            VALUE post_rest = rest_arg(ast_value, RNODE_FNDPTN(node)->post_rest_arg);
             return rb_ary_new_from_args(4,
-                                        NEW_CHILD(ast, RNODE_FNDPTN(node)->nd_pconst),
+                                        NEW_CHILD(ast_value, RNODE_FNDPTN(node)->nd_pconst),
                                         pre_rest,
-                                        NEW_CHILD(ast, RNODE_FNDPTN(node)->args),
+                                        NEW_CHILD(ast_value, RNODE_FNDPTN(node)->args),
                                         post_rest);
         }
       case NODE_HSHPTN:
         {
             VALUE kwrest = RNODE_HSHPTN(node)->nd_pkwrestarg == NODE_SPECIAL_NO_REST_KEYWORD ? ID2SYM(rb_intern("NODE_SPECIAL_NO_REST_KEYWORD")) :
-                                                                                 NEW_CHILD(ast, RNODE_HSHPTN(node)->nd_pkwrestarg);
+                                                                                 NEW_CHILD(ast_value, RNODE_HSHPTN(node)->nd_pkwrestarg);
 
             return rb_ary_new_from_args(3,
-                                        NEW_CHILD(ast, RNODE_HSHPTN(node)->nd_pconst),
-                                        NEW_CHILD(ast, RNODE_HSHPTN(node)->nd_pkwargs),
+                                        NEW_CHILD(ast_value, RNODE_HSHPTN(node)->nd_pconst),
+                                        NEW_CHILD(ast_value, RNODE_HSHPTN(node)->nd_pkwargs),
                                         kwrest);
         }
+      case NODE_LINE:
+        return rb_ary_new_from_args(1, rb_node_line_lineno_val(node));
+      case NODE_FILE:
+        return rb_ary_new_from_args(1, rb_node_file_path_val(node));
+      case NODE_ENCODING:
+        return rb_ary_new_from_args(1, rb_node_encoding_val(node));
       case NODE_ERROR:
-        return rb_ary_new_from_node_args(ast, 0);
+        return rb_ary_new_from_node_args(ast_value, 0);
       case NODE_ARGS_AUX:
-      case NODE_RIPPER:
-      case NODE_RIPPER_VALUES:
       case NODE_LAST:
         break;
     }
@@ -711,7 +761,250 @@ ast_node_children(rb_execution_context_t *ec, VALUE self)
     struct ASTNodeData *data;
     TypedData_Get_Struct(self, struct ASTNodeData, &rb_node_type, data);
 
-    return node_children(data->ast, data->node);
+    return node_children(data->ast_value, data->node);
+}
+
+static int
+null_loc_p(rb_code_location_t *loc)
+{
+    return (loc->beg_pos.lineno == 0 && loc->beg_pos.column == -1 && loc->end_pos.lineno == 0 && loc->end_pos.column == -1);
+}
+
+static VALUE
+location_new(rb_code_location_t *loc)
+{
+    VALUE obj;
+    struct ASTLocationData *data;
+
+    if (null_loc_p(loc)) return Qnil;
+
+    obj = TypedData_Make_Struct(rb_cLocation, struct ASTLocationData, &rb_location_type, data);
+    data->first_lineno = loc->beg_pos.lineno;
+    data->first_column = loc->beg_pos.column;
+    data->last_lineno = loc->end_pos.lineno;
+    data->last_column = loc->end_pos.column;
+
+    return obj;
+}
+
+static VALUE
+node_locations(VALUE ast_value, const NODE *node)
+{
+    enum node_type type = nd_type(node);
+    switch (type) {
+      case NODE_ALIAS:
+        return rb_ary_new_from_args(2,
+                                    location_new(nd_code_loc(node)),
+                                    location_new(&RNODE_ALIAS(node)->keyword_loc));
+      case NODE_AND:
+        return rb_ary_new_from_args(2,
+                                    location_new(nd_code_loc(node)),
+                                    location_new(&RNODE_AND(node)->operator_loc));
+      case NODE_BLOCK_PASS:
+        return rb_ary_new_from_args(2,
+                                    location_new(nd_code_loc(node)),
+                                    location_new(&RNODE_BLOCK_PASS(node)->operator_loc));
+      case NODE_BREAK:
+        return rb_ary_new_from_args(2,
+                                    location_new(nd_code_loc(node)),
+                                    location_new(&RNODE_BREAK(node)->keyword_loc));
+      case NODE_CASE:
+        return rb_ary_new_from_args(3,
+                                    location_new(nd_code_loc(node)),
+                                    location_new(&RNODE_CASE(node)->case_keyword_loc),
+                                    location_new(&RNODE_CASE(node)->end_keyword_loc));
+      case NODE_CASE2:
+        return rb_ary_new_from_args(3,
+                                    location_new(nd_code_loc(node)),
+                                    location_new(&RNODE_CASE2(node)->case_keyword_loc),
+                                    location_new(&RNODE_CASE2(node)->end_keyword_loc));
+      case NODE_CASE3:
+        return rb_ary_new_from_args(3,
+                                    location_new(nd_code_loc(node)),
+                                    location_new(&RNODE_CASE3(node)->case_keyword_loc),
+                                    location_new(&RNODE_CASE3(node)->end_keyword_loc));
+      case NODE_CLASS:
+        return rb_ary_new_from_args(4,
+                                    location_new(nd_code_loc(node)),
+                                    location_new(&RNODE_CLASS(node)->class_keyword_loc),
+                                    location_new(&RNODE_CLASS(node)->inheritance_operator_loc),
+                                    location_new(&RNODE_CLASS(node)->end_keyword_loc));
+      case NODE_COLON2:
+        return rb_ary_new_from_args(3,
+                                    location_new(nd_code_loc(node)),
+                                    location_new(&RNODE_COLON2(node)->delimiter_loc),
+                                    location_new(&RNODE_COLON2(node)->name_loc));
+      case NODE_COLON3:
+        return rb_ary_new_from_args(3,
+                                    location_new(nd_code_loc(node)),
+                                    location_new(&RNODE_COLON3(node)->delimiter_loc),
+                                    location_new(&RNODE_COLON3(node)->name_loc));
+      case NODE_DEFINED:
+        return rb_ary_new_from_args(2,
+                                    location_new(nd_code_loc(node)),
+                                    location_new(&RNODE_DEFINED(node)->keyword_loc));
+      case NODE_DOT2:
+        return rb_ary_new_from_args(2,
+                                    location_new(nd_code_loc(node)),
+                                    location_new(&RNODE_DOT2(node)->operator_loc));
+      case NODE_DOT3:
+        return rb_ary_new_from_args(2,
+                                    location_new(nd_code_loc(node)),
+                                    location_new(&RNODE_DOT3(node)->operator_loc));
+      case NODE_EVSTR:
+        return rb_ary_new_from_args(3,
+                                    location_new(nd_code_loc(node)),
+                                    location_new(&RNODE_EVSTR(node)->opening_loc),
+                                    location_new(&RNODE_EVSTR(node)->closing_loc));
+      case NODE_FLIP2:
+        return rb_ary_new_from_args(2,
+                                    location_new(nd_code_loc(node)),
+                                    location_new(&RNODE_FLIP2(node)->operator_loc));
+      case NODE_FLIP3:
+        return rb_ary_new_from_args(2,
+                                    location_new(nd_code_loc(node)),
+                                    location_new(&RNODE_FLIP3(node)->operator_loc));
+      case NODE_FOR:
+        return rb_ary_new_from_args(5,
+                                    location_new(nd_code_loc(node)),
+                                    location_new(&RNODE_FOR(node)->for_keyword_loc),
+                                    location_new(&RNODE_FOR(node)->in_keyword_loc),
+                                    location_new(&RNODE_FOR(node)->do_keyword_loc),
+                                    location_new(&RNODE_FOR(node)->end_keyword_loc));
+      case NODE_LAMBDA:
+        return rb_ary_new_from_args(4,
+                                    location_new(nd_code_loc(node)),
+                                    location_new(&RNODE_LAMBDA(node)->operator_loc),
+                                    location_new(&RNODE_LAMBDA(node)->opening_loc),
+                                    location_new(&RNODE_LAMBDA(node)->closing_loc));
+      case NODE_IF:
+        return rb_ary_new_from_args(4,
+                                    location_new(nd_code_loc(node)),
+                                    location_new(&RNODE_IF(node)->if_keyword_loc),
+                                    location_new(&RNODE_IF(node)->then_keyword_loc),
+                                    location_new(&RNODE_IF(node)->end_keyword_loc));
+      case NODE_IN:
+        return rb_ary_new_from_args(4,
+                                    location_new(nd_code_loc(node)),
+                                    location_new(&RNODE_IN(node)->in_keyword_loc),
+                                    location_new(&RNODE_IN(node)->then_keyword_loc),
+                                    location_new(&RNODE_IN(node)->operator_loc));
+      case NODE_MODULE:
+        return rb_ary_new_from_args(3,
+                                    location_new(nd_code_loc(node)),
+                                    location_new(&RNODE_MODULE(node)->module_keyword_loc),
+                                    location_new(&RNODE_MODULE(node)->end_keyword_loc));
+      case NODE_NEXT:
+        return rb_ary_new_from_args(2,
+                                    location_new(nd_code_loc(node)),
+                                    location_new(&RNODE_NEXT(node)->keyword_loc));
+      case NODE_OR:
+        return rb_ary_new_from_args(2,
+                                    location_new(nd_code_loc(node)),
+                                    location_new(&RNODE_OR(node)->operator_loc));
+      case NODE_OP_ASGN1:
+        return rb_ary_new_from_args(5,
+                                    location_new(nd_code_loc(node)),
+                                    location_new(&RNODE_OP_ASGN1(node)->call_operator_loc),
+                                    location_new(&RNODE_OP_ASGN1(node)->opening_loc),
+                                    location_new(&RNODE_OP_ASGN1(node)->closing_loc),
+                                    location_new(&RNODE_OP_ASGN1(node)->binary_operator_loc));
+      case NODE_OP_ASGN2:
+        return rb_ary_new_from_args(4,
+                                    location_new(nd_code_loc(node)),
+                                    location_new(&RNODE_OP_ASGN2(node)->call_operator_loc),
+                                    location_new(&RNODE_OP_ASGN2(node)->message_loc),
+                                    location_new(&RNODE_OP_ASGN2(node)->binary_operator_loc));
+      case NODE_POSTEXE:
+        return rb_ary_new_from_args(4,
+                                    location_new(nd_code_loc(node)),
+                                    location_new(&RNODE_POSTEXE(node)->keyword_loc),
+                                    location_new(&RNODE_POSTEXE(node)->opening_loc),
+                                    location_new(&RNODE_POSTEXE(node)->closing_loc));
+      case NODE_REDO:
+        return rb_ary_new_from_args(2,
+                                    location_new(nd_code_loc(node)),
+                                    location_new(&RNODE_REDO(node)->keyword_loc));
+      case NODE_REGX:
+        return rb_ary_new_from_args(4,
+                                    location_new(nd_code_loc(node)),
+                                    location_new(&RNODE_REGX(node)->opening_loc),
+                                    location_new(&RNODE_REGX(node)->content_loc),
+                                    location_new(&RNODE_REGX(node)->closing_loc));
+      case NODE_RETURN:
+        return rb_ary_new_from_args(2,
+                                    location_new(nd_code_loc(node)),
+                                    location_new(&RNODE_RETURN(node)->keyword_loc));
+
+      case NODE_SCLASS:
+        return rb_ary_new_from_args(4,
+                                    location_new(nd_code_loc(node)),
+                                    location_new(&RNODE_SCLASS(node)->class_keyword_loc),
+                                    location_new(&RNODE_SCLASS(node)->operator_loc),
+                                    location_new(&RNODE_SCLASS(node)->end_keyword_loc));
+
+      case NODE_SPLAT:
+        return rb_ary_new_from_args(2,
+                                    location_new(nd_code_loc(node)),
+                                    location_new(&RNODE_SPLAT(node)->operator_loc));
+      case NODE_SUPER:
+        return rb_ary_new_from_args(4,
+                                    location_new(nd_code_loc(node)),
+                                    location_new(&RNODE_SUPER(node)->keyword_loc),
+                                    location_new(&RNODE_SUPER(node)->lparen_loc),
+                                    location_new(&RNODE_SUPER(node)->rparen_loc));
+      case NODE_UNDEF:
+        return rb_ary_new_from_args(2,
+                                    location_new(nd_code_loc(node)),
+                                    location_new(&RNODE_UNDEF(node)->keyword_loc));
+      case NODE_UNLESS:
+        return rb_ary_new_from_args(4,
+                                    location_new(nd_code_loc(node)),
+                                    location_new(&RNODE_UNLESS(node)->keyword_loc),
+                                    location_new(&RNODE_UNLESS(node)->then_keyword_loc),
+                                    location_new(&RNODE_UNLESS(node)->end_keyword_loc));
+      case NODE_VALIAS:
+        return rb_ary_new_from_args(2,
+                                    location_new(nd_code_loc(node)),
+                                    location_new(&RNODE_VALIAS(node)->keyword_loc));
+      case NODE_WHEN:
+        return rb_ary_new_from_args(3,
+                                    location_new(nd_code_loc(node)),
+                                    location_new(&RNODE_WHEN(node)->keyword_loc),
+                                    location_new(&RNODE_WHEN(node)->then_keyword_loc));
+      case NODE_WHILE:
+        return rb_ary_new_from_args(3,
+                                    location_new(nd_code_loc(node)),
+                                    location_new(&RNODE_WHILE(node)->keyword_loc),
+                                    location_new(&RNODE_WHILE(node)->closing_loc));
+      case NODE_UNTIL:
+        return rb_ary_new_from_args(3,
+                                    location_new(nd_code_loc(node)),
+                                    location_new(&RNODE_UNTIL(node)->keyword_loc),
+                                    location_new(&RNODE_UNTIL(node)->closing_loc));
+      case NODE_YIELD:
+        return rb_ary_new_from_args(4,
+                                    location_new(nd_code_loc(node)),
+                                    location_new(&RNODE_YIELD(node)->keyword_loc),
+                                    location_new(&RNODE_YIELD(node)->lparen_loc),
+                                    location_new(&RNODE_YIELD(node)->rparen_loc));
+      case NODE_ARGS_AUX:
+      case NODE_LAST:
+        break;
+      default:
+        return rb_ary_new_from_args(1, location_new(nd_code_loc(node)));
+    }
+
+    rb_bug("node_locations: unknown node: %s", ruby_node_name(type));
+}
+
+static VALUE
+ast_node_locations(rb_execution_context_t *ec, VALUE self)
+{
+    struct ASTNodeData *data;
+    TypedData_Get_Struct(self, struct ASTNodeData, &rb_node_type, data);
+
+    return node_locations(data->ast_value, data->node);
 }
 
 static VALUE
@@ -753,10 +1046,37 @@ ast_node_last_column(rb_execution_context_t *ec, VALUE self)
 static VALUE
 ast_node_all_tokens(rb_execution_context_t *ec, VALUE self)
 {
+    long i;
     struct ASTNodeData *data;
+    rb_ast_t *ast;
+    rb_parser_ary_t *parser_tokens;
+    rb_parser_ast_token_t *parser_token;
+    VALUE str, loc, token, all_tokens;
+
     TypedData_Get_Struct(self, struct ASTNodeData, &rb_node_type, data);
+    ast = rb_ruby_ast_data_get(data->ast_value);
+
+    parser_tokens = ast->node_buffer->tokens;
+    if (parser_tokens == NULL) {
+        return Qnil;
+    }
+
+    all_tokens = rb_ary_new2(parser_tokens->len);
+    for (i = 0; i < parser_tokens->len; i++) {
+        parser_token = parser_tokens->data[i];
+        str = rb_str_new(parser_token->str->ptr, parser_token->str->len);
+        loc = rb_ary_new_from_args(4,
+            INT2FIX(parser_token->loc.beg_pos.lineno),
+            INT2FIX(parser_token->loc.beg_pos.column),
+            INT2FIX(parser_token->loc.end_pos.lineno),
+            INT2FIX(parser_token->loc.end_pos.column)
+        );
+        token = rb_ary_new_from_args(4, INT2FIX(parser_token->id), ID2SYM(rb_intern(parser_token->type_name)), str, loc);
+        rb_ary_push(all_tokens, token);
+    }
+    rb_ary_freeze(all_tokens);
 
-    return rb_ast_tokens(data->ast);
+    return all_tokens;
 }
 
 static VALUE
@@ -783,10 +1103,66 @@ static VALUE
 ast_node_script_lines(rb_execution_context_t *ec, VALUE self)
 {
     struct ASTNodeData *data;
+    rb_ast_t *ast;
     TypedData_Get_Struct(self, struct ASTNodeData, &rb_node_type, data);
-    VALUE ret = data->ast->body.script_lines;
-    if (!RB_TYPE_P(ret, T_ARRAY)) return Qnil;
-    return ret;
+    ast = rb_ruby_ast_data_get(data->ast_value);
+    rb_parser_ary_t *ret = ast->body.script_lines;
+    return rb_parser_build_script_lines_from(ret);
+}
+
+static VALUE
+ast_location_first_lineno(rb_execution_context_t *ec, VALUE self)
+{
+    struct ASTLocationData *data;
+    TypedData_Get_Struct(self, struct ASTLocationData, &rb_location_type, data);
+
+    return INT2NUM(data->first_lineno);
+}
+
+static VALUE
+ast_location_first_column(rb_execution_context_t *ec, VALUE self)
+{
+    struct ASTLocationData *data;
+    TypedData_Get_Struct(self, struct ASTLocationData, &rb_location_type, data);
+
+    return INT2NUM(data->first_column);
+}
+
+static VALUE
+ast_location_last_lineno(rb_execution_context_t *ec, VALUE self)
+{
+    struct ASTLocationData *data;
+    TypedData_Get_Struct(self, struct ASTLocationData, &rb_location_type, data);
+
+    return INT2NUM(data->last_lineno);
+}
+
+static VALUE
+ast_location_last_column(rb_execution_context_t *ec, VALUE self)
+{
+    struct ASTLocationData *data;
+    TypedData_Get_Struct(self, struct ASTLocationData, &rb_location_type, data);
+
+    return INT2NUM(data->last_column);
+}
+
+static VALUE
+ast_location_inspect(rb_execution_context_t *ec, VALUE self)
+{
+    VALUE str;
+    VALUE cname;
+    struct ASTLocationData *data;
+    TypedData_Get_Struct(self, struct ASTLocationData, &rb_location_type, data);
+
+    cname = rb_class_path(rb_obj_class(self));
+    str = rb_str_new2("#<");
+
+    rb_str_append(str, cname);
+    rb_str_catf(str, ":@%d:%d-%d:%d>",
+                data->first_lineno, data->first_column,
+                data->last_lineno, data->last_column);
+
+    return str;
 }
 
 #include "ast.rbinc"
@@ -796,5 +1172,7 @@ Init_ast(void)
 {
     rb_mAST = rb_define_module_under(rb_cRubyVM, "AbstractSyntaxTree");
     rb_cNode = rb_define_class_under(rb_mAST, "Node", rb_cObject);
+    rb_cLocation = rb_define_class_under(rb_mAST, "Location", rb_cObject);
     rb_undef_alloc_func(rb_cNode);
+    rb_undef_alloc_func(rb_cLocation);
 }
diff --git a/ast.rb b/ast.rb
index fa9b69507c..6380621780 100644
--- a/ast.rb
+++ b/ast.rb
@@ -13,9 +13,8 @@
 # access children nodes by name, etc.
 #
 # If you are looking for a stable API or an API working under multiple Ruby
-# implementations, consider using the _parser_ gem or Ripper. If you would
-# like to make RubyVM::AbstractSyntaxTree stable, please join the discussion
-# at https://bugs.ruby-lang.org/issues/14844.
+# implementations, consider using the _prism_ gem, which is the official
+# Ruby API to parse Ruby code.
 #
 module RubyVM::AbstractSyntaxTree
 
@@ -265,12 +264,69 @@ module RubyVM::AbstractSyntaxTree
       lines = script_lines
       if lines
         lines = lines[first_lineno - 1 .. last_lineno - 1]
-        lines[-1] = lines[-1][0...last_column]
-        lines[0] = lines[0][first_column..-1]
+        lines[-1] = lines[-1].byteslice(0...last_column)
+        lines[0] = lines[0].byteslice(first_column..-1)
         lines.join
       else
         nil
       end
     end
+
+    #  call-seq:
+    #     node.locations -> array
+    #
+    #  Returns location objects associated with the AST node.
+    #  The returned array contains RubyVM::AbstractSyntaxTree::Location.
+    def locations
+      Primitive.ast_node_locations
+    end
+  end
+
+  # RubyVM::AbstractSyntaxTree::Location instances are created by
+  # RubyVM::AbstractSyntaxTree::Node#locations.
+  #
+  # This class is MRI specific.
+  #
+  class Location
+
+    #  call-seq:
+    #     location.first_lineno -> integer
+    #
+    #  The line number in the source code where this AST's text began.
+    def first_lineno
+      Primitive.ast_location_first_lineno
+    end
+
+    #  call-seq:
+    #     location.first_column -> integer
+    #
+    #  The column number in the source code where this AST's text began.
+    def first_column
+      Primitive.ast_location_first_column
+    end
+
+    #  call-seq:
+    #     location.last_lineno -> integer
+    #
+    #  The line number in the source code where this AST's text ended.
+    def last_lineno
+      Primitive.ast_location_last_lineno
+    end
+
+    #  call-seq:
+    #     location.last_column -> integer
+    #
+    #  The column number in the source code where this AST's text ended.
+    def last_column
+      Primitive.ast_location_last_column
+    end
+
+    #  call-seq:
+    #     location.inspect -> string
+    #
+    #  Returns debugging information about this location as a string.
+    def inspect
+      Primitive.ast_location_inspect
+    end
   end
 end
diff --git a/autogen.sh b/autogen.sh
index f8cdf3c0c1..6cbc5dddab 100755
--- a/autogen.sh
+++ b/autogen.sh
@@ -1,17 +1,22 @@
 #!/bin/sh
 
+# Clear PWD to force commands to recompute working directory
 PWD=
+
+# Figure out the source directory for this script
+# configure.ac should be in the same place
 case "$0" in
-*/*) srcdir=`dirname $0`;;
-*) srcdir="";;
+    */* )  srcdir=`dirname "$0"` ;; # Called with path
+    *   )  srcdir="";; # Otherwise
 esac
 
-symlink='--install --symlink'
+# If install-only is explicitly requested, disable symlink flags
 case " $* " in
-    *" -i "*|*" --install "*)
-        # reset to copy missing standard auxiliary files, instead of symlinks
-        symlink=
-        ;;
+    *" -i "* | *" --install"* ) symlink_flags="" ;;
+    *                         ) symlink_flags="--install --symlink" ;;
 esac
 
-exec ${AUTORECONF:-autoreconf} ${symlink} "$@" ${srcdir:+"$srcdir"}
+exec ${AUTORECONF:-autoreconf} \
+     $symlink_flags \
+     "$@" \
+     $srcdir
diff --git a/basictest/test.rb b/basictest/test.rb
index 95875b52a6..711e4f4ab3 100755
--- a/basictest/test.rb
+++ b/basictest/test.rb
@@ -879,7 +879,7 @@ $x.sort!{|a,b| b-a}		# reverse sort
 test_ok($x == [7,5,3,2,1])
 
 # split test
-$x = "The Book of Mormon"
+$x = +"The Book of Mormon"
 test_ok($x.split(//).reverse!.join == $x.reverse)
 test_ok($x.reverse == $x.reverse!)
 test_ok("1 byte string".split(//).reverse.join(":") == "g:n:i:r:t:s: :e:t:y:b: :1")
@@ -1643,7 +1643,7 @@ test_ok(/^(?:ab+)+/ =~ "ababb" && $& == "ababb")
 test_ok(/(\s+\d+){2}/ =~ " 1 2" && $& == " 1 2")
 test_ok(/(?:\s+\d+){2}/ =~ " 1 2" && $& == " 1 2")
 
-$x = <<END;
+$x = +<<END;
 ABCD
 ABCD
 END
@@ -1682,12 +1682,12 @@ test_ok(?a == ?a)
 test_ok(?\C-a == "\1")
 test_ok(?\M-a == "\341")
 test_ok(?\M-\C-a == "\201")
-test_ok("a".upcase![0] == ?A)
-test_ok("A".downcase![0] == ?a)
-test_ok("abc".tr!("a-z", "A-Z") == "ABC")
-test_ok("aabbcccc".tr_s!("a-z", "A-Z") == "ABC")
-test_ok("abcc".squeeze!("a-z") == "abc")
-test_ok("abcd".delete!("bc") == "ad")
+test_ok("a".dup.upcase![0] == ?A)
+test_ok("A".dup.downcase![0] == ?a)
+test_ok("abc".dup.tr!("a-z", "A-Z") == "ABC")
+test_ok("aabbcccc".dup.tr_s!("a-z", "A-Z") == "ABC")
+test_ok("abcc".dup.squeeze!("a-z") == "abc")
+test_ok("abcd".dup.delete!("bc") == "ad")
 
 $x = "abcdef"
 $y = [ ?a, ?b, ?c, ?d, ?e, ?f ]
@@ -1700,7 +1700,7 @@ $x.each_byte {|i|
 }
 test_ok(!$bad)
 
-s = "a string"
+s = +"a string"
 s[0..s.size]="another string"
 test_ok(s == "another string")
 
diff --git a/benchmark/README.md b/benchmark/README.md
index e11381cad9..9f9192685e 100644
--- a/benchmark/README.md
+++ b/benchmark/README.md
@@ -27,6 +27,7 @@ benchmark-driver benchmark/*.yml
 See also:
 
 ```console
+benchmark-driver --help
 Usage: benchmark-driver [options] RUBY|YAML...
     -r, --runner TYPE                Specify runner type: ips, time, memory, once, block (default: ips)
     -o, --output TYPE                Specify output type: compare, simple, markdown, record, all (default: compare)
@@ -39,7 +40,7 @@ Usage: benchmark-driver [options] RUBY|YAML...
         --filter REGEXP              Filter out benchmarks with given regexp
         --run-duration SECONDS       Warmup estimates loop_count to run for this duration (default: 3)
         --timeout SECONDS            Timeout ruby command execution with timeout(1)
-    -v, --verbose                    Verbose mode. Multiple -v options increase visilibity (max: 2)
+    -v, --verbose                    Verbose mode. Multiple -v options increase visibility (max: 2)
 ```
 
 ## make benchmark
diff --git a/benchmark/app_aobench.rb b/benchmark/app_aobench.rb
index 16296af12b..c1546e08ab 100644
--- a/benchmark/app_aobench.rb
+++ b/benchmark/app_aobench.rb
@@ -151,7 +151,7 @@ def clamp(f)
   i.to_i
 end
 
-def otherBasis(basis, n)
+def orthoBasis(basis, n)
   basis[2] = Vec.new(n.x, n.y, n.z)
   basis[1] = Vec.new(0.0, 0.0, 0.0)
 
@@ -183,7 +183,7 @@ class Scene
 
   def ambient_occlusion(isect)
     basis = Array.new
-    otherBasis(basis, isect.n)
+    orthoBasis(basis, isect.n)
 
     ntheta    = NAO_SAMPLES
     nphi      = NAO_SAMPLES
diff --git a/benchmark/app_fib.rb b/benchmark/app_fib.rb
index 34a7b2e725..e61bc8aa32 100644
--- a/benchmark/app_fib.rb
+++ b/benchmark/app_fib.rb
@@ -1,4 +1,4 @@
-def fib n
+def fib(n)
   if n < 3
     1
   else
diff --git a/benchmark/array_large_literal.yml b/benchmark/array_large_literal.yml
new file mode 100644
index 0000000000..423d68391f
--- /dev/null
+++ b/benchmark/array_large_literal.yml
@@ -0,0 +1,19 @@
+prelude: |
+  def def_array(size)
+    Object.class_eval(<<-END)
+      def array_#{size}
+        x = 1
+        [#{(['x'] * size).join(',')}]
+      end
+    END
+  end
+  def_array(100)
+  def_array(1000)
+  def_array(10000)
+  def_array(100000)
+benchmark:
+  array_100: array_100
+  array_1000: array_1000
+  array_10000: array_10000
+  array_100000: array_100000
+
diff --git a/benchmark/class_superclass.yml b/benchmark/class_superclass.yml
new file mode 100644
index 0000000000..847ff811f1
--- /dev/null
+++ b/benchmark/class_superclass.yml
@@ -0,0 +1,23 @@
+prelude: |
+  class SimpleClass; end
+  class OneModuleClass
+    1.times { include Module.new }
+  end
+  class MediumClass
+    10.times { include Module.new }
+  end
+  class LargeClass
+    100.times { include Module.new }
+  end
+benchmark:
+  object_class_superclass: |
+    Object.superclass
+  simple_class_superclass: |
+    SimpleClass.superclass
+  one_module_class: |
+    OneModuleClass.superclass
+  medium_class_superclass: |
+    MediumClass.superclass
+  large_class_superclass: |
+    LargeClass.superclass
+loop_count: 20000000
diff --git a/benchmark/dir_pwd.yml b/benchmark/dir_pwd.yml
new file mode 100644
index 0000000000..c435d3ac5e
--- /dev/null
+++ b/benchmark/dir_pwd.yml
@@ -0,0 +1,2 @@
+benchmark:
+  pwd: Dir.pwd
diff --git a/benchmark/file_basename.yml b/benchmark/file_basename.yml
new file mode 100644
index 0000000000..fbd78785aa
--- /dev/null
+++ b/benchmark/file_basename.yml
@@ -0,0 +1,6 @@
+prelude: |
+  # frozen_string_literal: true
+benchmark:
+  long: File.basename("/Users/george/src/github.com/ruby/ruby/benchmark/file_dirname.yml")
+  long_name: File.basename("Users_george_src_github.com_ruby_ruby_benchmark_file_dirname.yml")
+  withext: File.basename("/Users/george/src/github.com/ruby/ruby/benchmark/file_dirname.yml", ".yml")
diff --git a/benchmark/file_dirname.yml b/benchmark/file_dirname.yml
new file mode 100644
index 0000000000..43a81c9371
--- /dev/null
+++ b/benchmark/file_dirname.yml
@@ -0,0 +1,6 @@
+prelude: |
+  # frozen_string_literal: true
+benchmark:
+  long: File.dirname("/Users/george/src/github.com/ruby/ruby/benchmark/file_dirname.yml")
+  short: File.dirname("foo/bar")
+  n_4: File.dirname("/Users/george/src/github.com/ruby/ruby/benchmark/file_dirname.yml", 4)
diff --git a/benchmark/file_expand_path.yml b/benchmark/file_expand_path.yml
new file mode 100644
index 0000000000..9e503ab003
--- /dev/null
+++ b/benchmark/file_expand_path.yml
@@ -0,0 +1,4 @@
+prelude: |
+  # frozen_string_literal: true
+benchmark:
+  expand_path: File.expand_path("../../foo.txt", __FILE__)
diff --git a/benchmark/file_extname.yml b/benchmark/file_extname.yml
new file mode 100644
index 0000000000..fb16e55840
--- /dev/null
+++ b/benchmark/file_extname.yml
@@ -0,0 +1,6 @@
+prelude: |
+  # frozen_string_literal: true
+benchmark:
+  long: File.extname("/Users/george/src/github.com/ruby/ruby/benchmark/file_dirname.yml")
+  long_name: File.extname("Users_george_src_github.com_ruby_ruby_benchmark_file_dirname.yml")
+  short: File.extname("foo/bar")
diff --git a/benchmark/file_join.yml b/benchmark/file_join.yml
new file mode 100644
index 0000000000..845257cf1e
--- /dev/null
+++ b/benchmark/file_join.yml
@@ -0,0 +1,7 @@
+prelude: |
+  # frozen_string_literal: true
+benchmark:
+  two_strings: File.join(__FILE__, "path")
+  many_strings: File.join(__FILE__, "path", "a", "b", "c", "d")
+  array: File.join([__FILE__, "path", "a", "b", "c", "d"])
+  mixed: File.join(__FILE__, "path", "a", "b", ["c", "d"])
diff --git a/benchmark/float_predicate.yml b/benchmark/float_predicate.yml
new file mode 100644
index 0000000000..b946937666
--- /dev/null
+++ b/benchmark/float_predicate.yml
@@ -0,0 +1,12 @@
+prelude: |
+  floats = [1.0, -1.0, 0.0, Float::NAN, Float::INFINITY, -Float::INFINITY]
+
+benchmark:
+  float_nan?: floats.each { |f| f.nan? }
+  float_finite?: floats.each { |f| f.finite? }
+  float_infinite?: floats.each { |f| f.infinite? }
+  float_zero?: floats.each { |f| f.zero? }
+  float_positive?: floats.each { |f| f.positive? }
+  float_negative?: floats.each { |f| f.negative? }
+
+loop_count: 1000000
diff --git a/benchmark/hash_aref_str_lit.yml b/benchmark/hash_aref_str_lit.yml
new file mode 100644
index 0000000000..ed8142bcf1
--- /dev/null
+++ b/benchmark/hash_aref_str_lit.yml
@@ -0,0 +1,20 @@
+prelude: |
+  # frozen_string_literal: true
+  hash = 10.times.to_h do |i|
+    [i, i]
+  end
+  dyn_sym = "dynamic_symbol".to_sym
+  binary = RubyVM::InstructionSequence.compile("# frozen_string_literal: true\n'iseq_load'").to_binary
+  iseq_literal_string = RubyVM::InstructionSequence.load_from_binary(binary).eval
+
+  hash[:some_symbol] = 1
+  hash[dyn_sym] = 2
+  hash["small"] = 3
+  hash["frozen_string_literal"] = 4
+  hash[iseq_literal_string] = 5
+benchmark:
+  symbol: hash[:some_symbol]
+  dyn_symbol: hash[dyn_sym]
+  small_lit: hash["small"]
+  frozen_lit: hash["frozen_string_literal"]
+  iseq_lit: hash[iseq_literal_string]
diff --git a/benchmark/hash_key.yml b/benchmark/hash_key.yml
new file mode 100644
index 0000000000..cab4cf9ca4
--- /dev/null
+++ b/benchmark/hash_key.yml
@@ -0,0 +1,5 @@
+prelude: |
+  obj = Object.new
+  hash = { obj => true }
+benchmark: hash.key?(obj)
+loop_count: 30000000
diff --git a/benchmark/hash_new.yml b/benchmark/hash_new.yml
new file mode 100644
index 0000000000..9d8e34187f
--- /dev/null
+++ b/benchmark/hash_new.yml
@@ -0,0 +1,16 @@
+prelude: |
+  has_hash_with_capa = Hash.instance_method(:initialize).parameters.include?([:key, :capacity])
+  strings_1k = 1_000.times.map { |i| -i.to_s.freeze }
+  strings_100k = 100_000.times.map { |i| -i.to_s.freeze }
+benchmark:
+  new: Hash.new
+  new_with_capa_1k: |
+    h = has_hash_with_capa ? Hash.new(capacity: strings_1k.size) : {}
+    strings_1k.each do |x|
+      h[x] = true
+    end
+  new_with_capa_100k: |
+    h = has_hash_with_capa ? Hash.new(capacity: strings_100k.size) : {}
+    strings_100k.each do |x|
+      h[x] = true
+    end
diff --git a/benchmark/int_to_s.yml b/benchmark/int_to_s.yml
new file mode 100644
index 0000000000..000dae9612
--- /dev/null
+++ b/benchmark/int_to_s.yml
@@ -0,0 +1,25 @@
+prelude: |
+  # frozen_string_literal: true
+  N1   = 5
+  N2   = 42
+  N3   = 400
+  N5   = 12345
+  N10  = 1_234_567_890
+  N19  = 4_611_686_018_427_387_903
+  NEG  = -1_234_567_890
+  BIG20  = 10 ** 19 + 12_345_678_901_234_567
+  BIG40  = 10 ** 39 + 123_456_789_012_345
+  BIG100 = 10 ** 99 + 42
+benchmark:
+  fix_1digit:   "N1.to_s"
+  fix_2digit:   "N2.to_s"
+  fix_3digit:   "N3.to_s"
+  fix_5digit:   "N5.to_s"
+  fix_10digit:  "N10.to_s"
+  fix_19digit:  "N19.to_s"
+  fix_negative: "NEG.to_s"
+  big_20digit:  "BIG20.to_s"
+  big_40digit:  "BIG40.to_s"
+  big_100digit: "BIG100.to_s"
+  interp_id:    '"id=#{N10}"'
+  interp_mixed: '"a=#{N2},b=#{N5},c=#{N10}"'
diff --git a/benchmark/integer_predicate.yml b/benchmark/integer_predicate.yml
new file mode 100644
index 0000000000..7c05ff2587
--- /dev/null
+++ b/benchmark/integer_predicate.yml
@@ -0,0 +1,9 @@
+prelude: |
+  nums = (0..9).to_a
+
+benchmark:
+  integer_zero?: nums.each { |n| n.zero? }
+  integer_even?: nums.each { |n| n.even? }
+  integer_odd?: nums.each { |n| n.odd? }
+
+loop_count: 1000000
diff --git a/benchmark/io_close.yml b/benchmark/io_close.yml
new file mode 100644
index 0000000000..a552872884
--- /dev/null
+++ b/benchmark/io_close.yml
@@ -0,0 +1,13 @@
+prelude: |
+  ios = 1000.times.map do
+    100.times.map{IO.pipe}
+  end
+benchmark:
+  # Close IO
+  io_close: |
+    # Process each batch of ios per iteration of the benchmark.
+    ios.pop.each do |r, w|
+      r.close
+      w.close
+    end
+loop_count: 100
diff --git a/benchmark/io_close_contended.yml b/benchmark/io_close_contended.yml
new file mode 100644
index 0000000000..1d9e4e0d0f
--- /dev/null
+++ b/benchmark/io_close_contended.yml
@@ -0,0 +1,21 @@
+prelude: |
+  ios = 100.times.map do
+    10.times.map do
+      pipe = IO.pipe.tap do |r, w|
+        Thread.new do
+          r.read
+        rescue IOError
+          # Ignore
+        end
+      end
+    end
+  end
+benchmark:
+  # Close IO
+  io_close_contended: |
+    # Process each batch of ios per iteration of the benchmark.
+    ios.pop.each do |r, w|
+      r.close
+      w.close
+    end
+loop_count: 10
diff --git a/benchmark/lib/benchmark_driver/runner/ractor.rb b/benchmark/lib/benchmark_driver/runner/ractor.rb
index c730b8e4a5..fd9c2dd4db 100644
--- a/benchmark/lib/benchmark_driver/runner/ractor.rb
+++ b/benchmark/lib/benchmark_driver/runner/ractor.rb
@@ -87,7 +87,7 @@ __bmdv_ractors << Ractor.new(__bmdv_loop_after - __bmdv_loop_before) { |__bmdv_l
 <% end %>
 
 # Wait for all Ractors before executing code to write results
-__bmdv_ractors.map!(&:take)
+__bmdv_ractors.map!(&:value)
 
 <% results.each do |result| %>
 File.write(<%= result.dump %>, __bmdv_ractors.shift)
diff --git a/benchmark/loop_each.yml b/benchmark/loop_each.yml
new file mode 100644
index 0000000000..1c757185a8
--- /dev/null
+++ b/benchmark/loop_each.yml
@@ -0,0 +1,4 @@
+prelude: |
+  arr = [nil] * 30_000_000
+benchmark:
+  loop_each: arr.each{|e|}
diff --git a/benchmark/loop_times_megamorphic.yml b/benchmark/loop_times_megamorphic.yml
new file mode 100644
index 0000000000..f9343ba897
--- /dev/null
+++ b/benchmark/loop_times_megamorphic.yml
@@ -0,0 +1,7 @@
+prelude: |
+  eval(<<~EOS)
+    def loop_times_megamorphic
+      #{"1.times {|i|};" * 1000}
+    end
+  EOS
+benchmark: loop_times_megamorphic
diff --git a/benchmark/module_eqq.yml b/benchmark/module_eqq.yml
index a561fb86dc..2f9c490d92 100644
--- a/benchmark/module_eqq.yml
+++ b/benchmark/module_eqq.yml
@@ -1,4 +1,5 @@
 prelude: |
+  module SomeModule; end
   class SimpleClass; end
   class MediumClass
     10.times { include Module.new }
@@ -24,4 +25,8 @@ benchmark:
     SimpleClass === LargeObj
   simple_class_eqq_huge_obj: |
     SimpleClass === HugeObj
-loop_count: 20000000
+  simple_class_eqq_module: |
+    SimpleClass === HugeObj
+  module_eqq_module: |
+    SomeModule === HugeObj
+loop_count: 10000000
diff --git a/benchmark/nilclass.yml b/benchmark/nilclass.yml
index fba67a5f6a..66234c4cdf 100644
--- a/benchmark/nilclass.yml
+++ b/benchmark/nilclass.yml
@@ -1,6 +1,16 @@
+prelude: |
+  def a = nil
 benchmark:
+  rationalize:
+    nil.rationalize
+  to_c: |
+    nil.to_c
   to_i: |
     nil.to_i
   to_f: |
     nil.to_f
+  to_r: |
+    nil.to_r
+  splat: |
+    a(*nil)
 loop_count: 100000
diff --git a/benchmark/object_allocate.yml b/benchmark/object_allocate.yml
index 93ff463e41..c6269923f0 100644
--- a/benchmark/object_allocate.yml
+++ b/benchmark/object_allocate.yml
@@ -11,6 +11,26 @@ prelude: |
   class OneTwentyEight
     128.times { include(Module.new) }
   end
+  class OnePositional
+    def initialize a; end
+  end
+  class TwoPositional
+    def initialize a, b; end
+  end
+  class ThreePositional
+    def initialize a, b, c; end
+  end
+  class FourPositional
+    def initialize a, b, c, d; end
+  end
+  class KWArg
+    def initialize a:, b:, c:, d:
+    end
+  end
+  class Mixed
+    def initialize a, b, c:, d:
+    end
+  end
   # Disable GC to see raw throughput:
   GC.disable
 benchmark:
@@ -18,4 +38,12 @@ benchmark:
   allocate_32_deep: ThirtyTwo.new
   allocate_64_deep: SixtyFour.new
   allocate_128_deep: OneTwentyEight.new
+  allocate_1_positional_params: OnePositional.new(1)
+  allocate_2_positional_params: TwoPositional.new(1, 2)
+  allocate_3_positional_params: ThreePositional.new(1, 2, 3)
+  allocate_4_positional_params: FourPositional.new(1, 2, 3, 4)
+  allocate_kwarg_params: "KWArg.new(a: 1, b: 2, c: 3, d: 4)"
+  allocate_mixed_params: "Mixed.new(1, 2, c: 3, d: 4)"
+  allocate_no_params: "Object.new"
+  allocate_allocate: "Object.allocate"
 loop_count: 100000
diff --git a/benchmark/object_class.yml b/benchmark/object_class.yml
new file mode 100644
index 0000000000..1e5409d1e2
--- /dev/null
+++ b/benchmark/object_class.yml
@@ -0,0 +1,40 @@
+prelude: |
+  def get_class(obj)
+    i = 10_000
+    while i > 0
+      i -= 1
+      # 100 times per loop
+      obj.class; obj.class; obj.class; obj.class; obj.class; obj.class; obj.class; obj.class; obj.class; obj.class;
+      obj.class; obj.class; obj.class; obj.class; obj.class; obj.class; obj.class; obj.class; obj.class; obj.class;
+      obj.class; obj.class; obj.class; obj.class; obj.class; obj.class; obj.class; obj.class; obj.class; obj.class;
+      obj.class; obj.class; obj.class; obj.class; obj.class; obj.class; obj.class; obj.class; obj.class; obj.class;
+      obj.class; obj.class; obj.class; obj.class; obj.class; obj.class; obj.class; obj.class; obj.class; obj.class;
+      obj.class; obj.class; obj.class; obj.class; obj.class; obj.class; obj.class; obj.class; obj.class; obj.class;
+      obj.class; obj.class; obj.class; obj.class; obj.class; obj.class; obj.class; obj.class; obj.class; obj.class;
+      obj.class; obj.class; obj.class; obj.class; obj.class; obj.class; obj.class; obj.class; obj.class; obj.class;
+      obj.class; obj.class; obj.class; obj.class; obj.class; obj.class; obj.class; obj.class; obj.class; obj.class;
+      obj.class; obj.class; obj.class; obj.class; obj.class; obj.class; obj.class; obj.class; obj.class; obj.class;
+      obj.class; obj.class; obj.class; obj.class; obj.class; obj.class; obj.class; obj.class; obj.class; obj.class;
+    end
+  end
+
+  class Obj
+  end
+  obj = Obj.new
+
+  singleton = Obj.new
+  def singleton.bar
+  end
+
+  extended = Obj.new
+  2.times do
+    extended.extend Module.new
+  end
+
+  immediate = 1.4
+benchmark:
+  obj: get_class(obj)
+  extended: get_class(extended)
+  singleton: get_class(singleton)
+  immediate: get_class(immediate)
+loop_count: 1000
diff --git a/benchmark/object_id.yml b/benchmark/object_id.yml
new file mode 100644
index 0000000000..2bd52b923f
--- /dev/null
+++ b/benchmark/object_id.yml
@@ -0,0 +1,4 @@
+benchmark:
+  baseline: "Object.new"
+  object_id: "Object.new.object_id"
+# loop_count: 100000
diff --git a/benchmark/pathname.yml b/benchmark/pathname.yml
new file mode 100644
index 0000000000..bcf3011eab
--- /dev/null
+++ b/benchmark/pathname.yml
@@ -0,0 +1,15 @@
+prelude: |
+  abs = Pathname("/a")
+  rel = Pathname("a")
+  p1 = Pathname.new('foo/././././bar')
+  p2 = Pathname.new('foo/bar/./../..')
+  p3 = Pathname.new('foo/bar/zot')
+benchmark:
+  p1+p2: p1+p2
+  abs.root?: abs.root?
+  rel.root?: rel.root?
+  abs.absolute?: abs.absolute?
+  rel.absolute?: rel.absolute?
+  p1.cleanpath: p1.cleanpath
+  p2.cleanpath: p2.cleanpath
+  relative_path_from: p3.relative_path_from('foo/bar/qux/quax')
diff --git a/benchmark/ractor_string_fstring.yml b/benchmark/ractor_string_fstring.yml
new file mode 100644
index 0000000000..14b92d8fd8
--- /dev/null
+++ b/benchmark/ractor_string_fstring.yml
@@ -0,0 +1,18 @@
+type: lib/benchmark_driver/runner/ractor
+benchmark:
+  ractor_fstring_random: |
+    i = 0
+    str = "same".dup
+    while i < 2000000
+      -(i.to_s.freeze)
+      i += 1
+    end
+  ractor_fstring_same: |
+    i = 0
+    str = "same".dup
+    while i < 2000000
+      -str
+      i += 1
+    end
+loop_count: 1
+ractor: 4
diff --git a/benchmark/realpath.yml b/benchmark/realpath.yml
index 90a029d5b9..6b6a4836b0 100644
--- a/benchmark/realpath.yml
+++ b/benchmark/realpath.yml
@@ -12,6 +12,9 @@ prelude: |
   relative_dir = 'b/c'
   absolute_dir = File.join(pwd, relative_dir)
   file_dir = 'c'
+teardown: |
+  require 'fileutils'
+  FileUtils.rm_rf('b')
 benchmark:
   relative_nil: "f.realpath(relative, nil)"
   absolute_nil: "f.realpath(absolute, nil)"
diff --git a/benchmark/scan.yaml b/benchmark/scan.yaml
new file mode 100644
index 0000000000..62ad1d6862
--- /dev/null
+++ b/benchmark/scan.yaml
@@ -0,0 +1,16 @@
+prelude: |
+  $LOAD_PATH.unshift(File.expand_path("lib"))
+  require "strscan"
+  str = "test string"
+  scanner = StringScanner.new(str)
+  str = "test"
+  reg = /test/
+benchmark:
+  check(reg): |
+    scanner.check(reg)
+  check(str): |
+    scanner.check(str)
+  match?(reg): |
+    scanner.match?(reg)
+  match?(str): |
+    scanner.match?(str)
diff --git a/benchmark/search.yaml b/benchmark/search.yaml
new file mode 100644
index 0000000000..42a50c90e6
--- /dev/null
+++ b/benchmark/search.yaml
@@ -0,0 +1,16 @@
+prelude: |
+  $LOAD_PATH.unshift(File.expand_path("lib"))
+  require "strscan"
+  str = "test string"
+  scanner = StringScanner.new(str)
+  str = "string"
+  reg = /string/
+benchmark:
+  check_until(reg): |
+    scanner.check_until(reg)
+  check_until(str): |
+    scanner.check_until(str)
+  exist?(reg): |
+    scanner.exist?(reg)
+  exist?(str): |
+    scanner.exist?(str)
diff --git a/benchmark/set.yml b/benchmark/set.yml
new file mode 100644
index 0000000000..061509cb1f
--- /dev/null
+++ b/benchmark/set.yml
@@ -0,0 +1,261 @@
+prelude: |
+  # First 1000 digits of pi
+  pi = <<~END.gsub(/\D/, '')
+    31415926535897932384626433832795028841971693993751058209749445923078164062862089
+    98628034825342117067982148086513282306647093844609550582231725359408128481117450
+    28410270193852110555964462294895493038196442881097566593344612847564823378678316
+    52712019091456485669234603486104543266482133936072602491412737245870066063155881
+    74881520920962829254091715364367892590360011330530548820466521384146951941511609
+    43305727036575959195309218611738193261179310511854807446237996274956735188575272
+    48912279381830119491298336733624406566430860213949463952247371907021798609437027
+    70539217176293176752384674818467669405132000568127145263560827785771342757789609
+    17363717872146844090122495343014654958537105079227968925892354201995611212902196
+    08640344181598136297747713099605187072113499999983729780499510597317328160963185
+    95024459455346908302642522308253344685035261931188171010003137838752886587533208
+    38142061717766914730359825349042875546873115956286388235378759375195778185778053
+    21712268066130019278766111959092164201989380952572010654505906988788448549
+  END
+  array1 = 10.times.flat_map do |i|
+    pi[i...].chars.each_slice(10).map(&:join)
+  end
+  array2 = array1.map(&:reverse)
+  array1.map!(&:to_i)
+  array2.map!(&:to_i)
+  a1 = array1[...10]
+  a2 = array1[...100]
+  a3 = array1
+  oa1 = array2[...10]
+  oa2 = array2[...100]
+  oa3 = array2
+  s0 = Set.new
+  s0 = Set.new
+  s1 = Set.new(a1)
+  s2 = Set.new(a2)
+  s3 = Set.new(a3)
+  o0 = Set.new
+  o1 = Set.new(array2[...10])
+  o2 = Set.new(array2[...100])
+  o3 = Set.new(array2)
+  d0 = s0.dup
+  d1 = s1.dup
+  d2 = s2.dup
+  d3 = s3.dup
+  ss1 = s1 - a1[-1..-1]
+  ss2 = s2 - a2[-1..-1]
+  ss3 = s3 - a3[-1..-1]
+  os1 = o1 - oa1[-1..-1]
+  os2 = o2 - oa2[-1..-1]
+  os3 = o3 - oa3[-1..-1]
+  member = a1.first
+  cbi = s0.dup.compare_by_identity
+  ns = Set[s3, o3, d3]
+  set_subclass = Class.new(Set)
+
+benchmark:
+  new_0: Set.new
+  new_10: Set.new(a1)
+  new_100: Set.new(a2)
+  new_1000: Set.new(a3)
+  aref_0: Set[]
+  aref_10: Set[*a1]
+  aref_100: Set[*a2]
+  aref_1000: Set[*a3]
+  amp_0: s0 & o0
+  amp_10: s1 & o1
+  amp_100: s2 & o2
+  amp_1000: s3 & o3
+  amp_same_0: s0 & d0
+  amp_same_10: s1 & d1
+  amp_same_100: s2 & d2
+  amp_same_1000: s3 & d3
+  minus_0: s0 - o0
+  minus_10: s1 - o1
+  minus_100: s2 - o2
+  minus_1000: s3 - o3
+  minus_same_0: s0 - d0
+  minus_same_10: s1 - d1
+  minus_same_100: s2 - d2
+  minus_same_1000: s3 - d3
+  spaceship_0: s0 <=> o0
+  spaceship_diff_10: s1 <=> o1
+  spaceship_diff_100: s2 <=> o2
+  spaceship_diff_1000: s2 <=> o3
+  spaceship_sub_10: s1 <=> ss1
+  spaceship_sub_100: s2 <=> ss2
+  spaceship_sub_1000: s2 <=> ss3
+  spaceship_sup_10: ss1 <=> s1
+  spaceship_sup_100: ss2 <=> s2
+  spaceship_sup_1000: ss2 <=> s3
+  eq_0: s0 == o0
+  eq_10: s1 == o1
+  eq_100: s2 == o2
+  eq_1000: s3 == o3
+  eq_same_0: s0 == d0
+  eq_same_10: s1 == d1
+  eq_same_100: s2 == d2
+  eq_same_1000: s3 == d3
+  xor_0: s0 ^ o0
+  xor_10: s1 ^ o1
+  xor_100: s2 ^ o2
+  xor_1000: s3 ^ o3
+  xor_same_0: s0 ^ d0
+  xor_same_10: s1 ^ d1
+  xor_same_100: s2 ^ d2
+  xor_same_1000: s3 ^ d3
+  pipe_0: s0 | o0
+  pipe_10: s1 | o1
+  pipe_100: s2 | o2
+  pipe_1000: s3 | o3
+  pipe_same_0: s0 | d0
+  pipe_same_10: s1 | d1
+  pipe_same_100: s2 | d2
+  pipe_same_1000: s3 | d3
+  add: a3.each { s0.add(it) }
+  add_exist: a3.each { s3.add(it) }
+  addq: a3.each { s0.add?(it) }
+  addq_exist: a3.each { s3.add?(it) }
+  classify_0: s0.classify { it }
+  classify_10: s1.classify { it & 2 }
+  classify_100: s2.classify { it & 8 }
+  classify_1000: s3.classify { it & 32 }
+  clear: s0.clear
+  collect_0: s0.collect! { it }
+  collect_10: s1.collect! { it }
+  collect_100: s2.collect! { it }
+  collect_1000: s3.collect! { it }
+  compare_by_identity_0: s0.dup.compare_by_identity
+  compare_by_identity_10: s1.dup.compare_by_identity
+  compare_by_identity_100: s2.dup.compare_by_identity
+  compare_by_identity_1000: s3.dup.compare_by_identity
+  compare_by_identityq_false: s0.compare_by_identity?
+  compare_by_identityq_true: cbi.compare_by_identity?
+  clone_0: s0.clone
+  clone_10: s1.clone
+  clone_100: s2.clone
+  clone_1000: s3.clone
+  delete: a3.each { s3.delete(it) }
+  delete_not_exist: a3.each { o3.delete(it) }
+  deleteq: a3.each { s3.delete?(it) }
+  deleteq_not_exist: a3.each { o3.delete?(it) }
+  delete_if_0: s0.delete_if { it }
+  delete_if_10: s1.delete_if { it & 2 == 0 }
+  delete_if_100: s2.delete_if { it & 2 == 0 }
+  delete_if_1000: s3.delete_if { it & 2 == 0 }
+  disjoint_0: s0.disjoint? o0
+  disjoint_10: s1.disjoint? o1
+  disjoint_100: s2.disjoint? o2
+  disjoint_1000: s3.disjoint? o3
+  disjoint_same_0: s0.disjoint? d0
+  disjoint_same_10: s1.disjoint? d1
+  disjoint_same_100: s2.disjoint? d2
+  disjoint_same_1000: s3.disjoint? d3
+  divide_1arity_0: s0.divide { true }
+  divide_1arity_10: s1.divide { it & 2 }
+  divide_1arity_100: s2.divide { it & 8 }
+  divide_1arity_1000: s3.divide { it & 32 }
+  divide_2arity_0: s0.divide { true }
+  divide_2arity_10: s1.divide { (_1 & 2) == (_2 & 2) }
+  divide_2arity_100: s2.divide { (_1 & 8) == (_2 & 8) }
+  divide_2arity_1000: s3.divide { (_1 & 32) == (_2 & 32) }
+  dup_0: s0.dup
+  dup_10: s1.dup
+  dup_100: s2.dup
+  dup_1000: s3.dup
+  each_0: s0.each { it }
+  each_10: s1.each { it }
+  each_100: s2.each { it }
+  each_1000: s3.each { it }
+  empty_true: s0.empty?
+  empty_false: s3.empty?
+  flatten: ns.flatten
+  flattenb: ns.flatten!
+  include_true_0: s0.include? member
+  include_true_10: s1.include? member
+  include_true_100: s2.include? member
+  include_true_1000: s3.include? member
+  include_false_0: s0.include?(-1)
+  include_false_10: s1.include?(-1)
+  include_false_100: s2.include?(-1)
+  include_false_1000: s3.include?(-1)
+  intersect_0: s0.intersect? o0
+  intersect_10: s1.intersect? o1
+  intersect_100: s2.intersect? o2
+  intersect_1000: s3.intersect? o3
+  intersect_same_0: s0.intersect? d0
+  intersect_same_10: s1.intersect? d1
+  intersect_same_100: s2.intersect? d2
+  intersect_same_1000: s3.intersect? d3
+  join_0: s0.join
+  join_10: s1.join
+  join_100: s2.join
+  join_1000: s3.join
+  join_arg_0: s0.join ""
+  join_arg_10: s1.join ""
+  join_arg_100: s2.join ""
+  join_arg_1000: s3.join ""
+  keep_if_0: s0.keep_if { it }
+  keep_if_10: s1.keep_if { it & 2 == 0 }
+  keep_if_100: s2.keep_if { it & 2 == 0 }
+  keep_if_1000: s3.keep_if { it & 2 == 0 }
+  merge_set: s0.dup.merge(s3, o3)
+  merge_enum: s0.dup.merge(array1, array2)
+  proper_subset_0: s0.proper_subset? s0
+  proper_subset_10: s1.proper_subset? ss1
+  proper_subset_100: s2.proper_subset? ss2
+  proper_subset_1000: s3.proper_subset? ss3
+  proper_subset_false_10: s1.proper_subset? os1
+  proper_subset_false_100: s2.proper_subset? os2
+  proper_subset_false_1000: s3.proper_subset? os3
+  proper_superset_0: s0.proper_superset? s0
+  proper_superset_10: ss1.proper_superset? s1
+  proper_superset_100: ss2.proper_superset? s2
+  proper_superset_1000: ss3.proper_superset? s3
+  proper_superset_false_10: os1.proper_superset? s1
+  proper_superset_false_100: os2.proper_superset? s2
+  proper_superset_false_1000: os3.proper_superset? s3
+  reject_0: s0.reject! { it }
+  reject_10: s1.reject! { it & 2 == 0 }
+  reject_100: s2.reject! { it & 2 == 0 }
+  reject_1000: s3.reject! { it & 2 == 0 }
+  replace_0: s = Set.new; array1.each { s.replace(s0) }
+  replace_10: s = Set.new; array1.each { s.replace(s1) }
+  replace_100: s = Set.new; array1.each { s.replace(s2) }
+  replace_1000: s = Set.new; array1.each { s.replace(s3) }
+  reset_0: s0.reset
+  reset_10: s1.reset
+  reset_100: s2.reset
+  reset_1000: s3.reset
+  select_0: s0.select! { it }
+  select_10: s1.select! { it & 2 == 0 }
+  select_100: s2.select! { it & 2 == 0 }
+  select_1000: s3.select! { it & 2 == 0 }
+  size_0: s0.size
+  size_10: s1.size
+  size_100: s2.size
+  size_1000: s3.size
+  subtract_set: s3.dup.subtract(os3)
+  subtract_enum: s3.dup.subtract(oa3)
+  subtract_same_set: s3.dup.subtract(s3)
+  subtract_same_enum: s3.dup.subtract(a3)
+  subset_0: s0.subset? s0
+  subset_10: s1.subset? ss1
+  subset_100: s2.subset? ss2
+  subset_1000: s3.subset? ss3
+  subset_false_10: s1.subset? os1
+  subset_false_100: s2.subset? os2
+  subset_false_1000: s3.subset? os3
+  superset_0: s0.superset? s0
+  superset_10: ss1.superset? s1
+  superset_100: ss2.superset? s2
+  superset_1000: ss3.superset? s3
+  superset_false_10: os1.superset? s1
+  superset_false_100: os2.superset? s2
+  superset_false_1000: os3.superset? s3
+  to_a_0: s0.to_a
+  to_a_10: s1.to_a
+  to_a_100: s2.to_a
+  to_a_1000: s3.to_a
+  to_set_0: s0.to_set
+  to_set_10: s1.to_set
+  to_set_100: s2.to_set
+  to_set_1000: s3.to_set
diff --git a/benchmark/string_casecmp.yml b/benchmark/string_casecmp.yml
index 2354040a04..88a3555c8a 100644
--- a/benchmark/string_casecmp.yml
+++ b/benchmark/string_casecmp.yml
@@ -20,7 +20,9 @@ benchmark:
   casecmp-10: lstr10.casecmp(ustr10)
   casecmp-100: lstr100.casecmp(ustr100)
   casecmp-1000: lstr1000.casecmp(ustr1000)
+  casecmp-1000vs10: lstr1000.casecmp(ustr10)
   casecmp-nonascii1: lnonascii1.casecmp(unonascii1)
   casecmp-nonascii10: lnonascii10.casecmp(unonascii10)
   casecmp-nonascii100: lnonascii100.casecmp(unonascii100)
   casecmp-nonascii1000: lnonascii1000.casecmp(unonascii1000)
+  casecmp-nonascii1000vs10: lnonascii1000.casecmp(unonascii10)
diff --git a/benchmark/string_codepoints.yml b/benchmark/string_codepoints.yml
new file mode 100644
index 0000000000..6a07db7ce1
--- /dev/null
+++ b/benchmark/string_codepoints.yml
@@ -0,0 +1,9 @@
+prelude: |
+  mixed_ascii64 = ("a" * 63 + "\u{100}") * 2048
+  mixed_ascii256 = ("a" * 255 + "\u{100}") * 512
+  utf8_2byte = "\u{100}" * 65536
+
+benchmark:
+  codepoints_mixed_ascii64: mixed_ascii64.codepoints
+  codepoints_mixed_ascii256: mixed_ascii256.codepoints
+  codepoints_utf8_2byte: utf8_2byte.codepoints
diff --git a/benchmark/string_coderange_scan.yml b/benchmark/string_coderange_scan.yml
new file mode 100644
index 0000000000..d47bbd2b30
--- /dev/null
+++ b/benchmark/string_coderange_scan.yml
@@ -0,0 +1,10 @@
+prelude: |
+  def unknown(s) = s.b.force_encoding("UTF-8")
+  multibyte   = unknown("\u{00e9}" * 16384)   # best case: every byte non-ASCII
+  alternating = unknown("\u{00e9}a" * 10922)  # worst case: non-ASCII then ASCII
+  ascii       = unknown("a" * 32768)          # baseline
+
+benchmark:
+  coderange_multibyte:   multibyte.dup.valid_encoding?
+  coderange_alternating: alternating.dup.valid_encoding?
+  coderange_ascii:       ascii.dup.valid_encoding?
diff --git a/benchmark/string_concat.yml b/benchmark/string_concat.yml
index da14692f5e..c07fd21013 100644
--- a/benchmark/string_concat.yml
+++ b/benchmark/string_concat.yml
@@ -1,8 +1,8 @@
 prelude: |
   CHUNK = "a" * 64
   UCHUNK = "é" * 32
-  SHORT = "a" * (GC::INTERNAL_CONSTANTS[:BASE_SLOT_SIZE] / 2)
-  LONG = "a" * (GC::INTERNAL_CONSTANTS[:BASE_SLOT_SIZE] * 2)
+  SHORT = "a" * (GC.stat_heap(0, :slot_size) / 2)
+  LONG = "a" * (GC.stat_heap(0, :slot_size) * 2)
   GC.disable # GC causes a lot of variance
 benchmark:
   binary_concat_7bit: |
@@ -45,7 +45,7 @@ benchmark:
       "#{CHUNK}#{CHUNK}#{CHUNK}#{CHUNK}#{CHUNK}#{CHUNK}#{CHUNK}#{CHUNK}#{CHUNK}#{CHUNK}" \
       "#{CHUNK}#{CHUNK}#{CHUNK}#{CHUNK}#{CHUNK}#{CHUNK}#{CHUNK}#{CHUNK}#{CHUNK}#{CHUNK}" \
       "#{CHUNK}#{CHUNK}#{CHUNK}#{CHUNK}#{CHUNK}#{CHUNK}#{CHUNK}#{CHUNK}#{CHUNK}"
-  interpolation_same_size_pool: |
+  interpolation_same_heap: |
     buffer = "#{SHORT}#{SHORT}"
-  interpolation_switching_size_pools: |
+  interpolation_switching_heaps: |
     buffer = "#{SHORT}#{LONG}"
diff --git a/benchmark/string_dup.yml b/benchmark/string_dup.yml
new file mode 100644
index 0000000000..90793f9f2a
--- /dev/null
+++ b/benchmark/string_dup.yml
@@ -0,0 +1,7 @@
+prelude: |
+  # frozen_string_literal: true
+benchmark:
+  uplus: |
+    +"A"
+  dup: |
+    "A".dup
diff --git a/benchmark/string_fstring.yml b/benchmark/string_fstring.yml
new file mode 100644
index 0000000000..cafef1f3fe
--- /dev/null
+++ b/benchmark/string_fstring.yml
@@ -0,0 +1,16 @@
+benchmark:
+  fstring_random: |
+    i = 0
+    str = "same".dup
+    while i < 5_000_000
+      -(i.to_s.freeze)
+      i += 1
+    end
+  fstring_same: |
+    i = 0
+    str = "same".dup
+    while i < 10_000_000
+      -str
+      i += 1
+    end
+loop_count: 1
diff --git a/benchmark/string_gsub.yml b/benchmark/string_gsub.yml
new file mode 100644
index 0000000000..c26e1a6498
--- /dev/null
+++ b/benchmark/string_gsub.yml
@@ -0,0 +1,54 @@
+prelude: |
+  # frozen_string_literal: true
+  STR = ((("a" * 31) + "<") * 1000).freeze
+  STR_UNICODE = ((("a" * 30) + "\u2028") * 1000).freeze
+  ESCAPED_CHARS_BINARY = {
+    "\u2028".b => '\u2028'.b,
+    "\u2029".b => '\u2029'.b,
+    ">".b => '\u003e'.b.freeze,
+    "<".b => '\u003c'.b.freeze,
+    "&".b => '\u0026'.b.freeze,
+  }
+  BINARY_PATTERN = Regexp.union(ESCAPED_CHARS_BINARY.keys)
+
+  ESCAPED_CHARS = {
+    "\u2028" => '\u2028',
+    "\u2029" => '\u2029',
+    ">" => '\u003e',
+    "<" => '\u003c',
+    "&" => '\u0026',
+  }
+  ESCAPE_PATTERN = Regexp.union(ESCAPED_CHARS.keys)
+
+  NO_MATCH_SHARED_STRING = ("a" * 100_000).freeze
+
+benchmark:
+  gsub_no_match_shared: |
+    str = NO_MATCH_SHARED_STRING.dup
+    str.gsub!("z", "x")
+    str
+
+  sub_no_match_shared: |
+    str = NO_MATCH_SHARED_STRING.dup
+    str.sub!("z", "x")
+    str
+
+  escape: |
+    str = STR.dup
+    str.gsub!(ESCAPE_PATTERN, ESCAPED_CHARS)
+    str
+
+  escape_bin: |
+    str = STR.b
+    str.gsub!(BINARY_PATTERN, ESCAPED_CHARS_BINARY)
+    str.force_encoding(Encoding::UTF_8)
+
+  escape_utf8: |
+    str = STR_UNICODE.dup
+    str.gsub!(ESCAPE_PATTERN, ESCAPED_CHARS)
+    str
+
+  escape_utf8_bin: |
+    str = STR_UNICODE.b
+    str.gsub!(BINARY_PATTERN, ESCAPED_CHARS_BINARY)
+    str.force_encoding(Encoding::UTF_8)
diff --git a/benchmark/string_inspect.yml b/benchmark/string_inspect.yml
new file mode 100644
index 0000000000..62a884e19d
--- /dev/null
+++ b/benchmark/string_inspect.yml
@@ -0,0 +1,13 @@
+prelude: |
+  ascii = "Hello, World! This is a benchmark test string." * 100
+  utf8 = "こんにちは世界。これはベンチマーク用のテスト文字列です。" * 100
+  mixed = ("Hello World! " + "テスト" + " is great! ") * 100
+  binary = ("\xE3\x81\x82" * 100).b
+  escapy = "\n\t\"\\\#" * 100
+
+benchmark:
+  inspect_ascii: ascii.inspect
+  inspect_utf8: utf8.inspect
+  inspect_mixed: mixed.inspect
+  inspect_binary: binary.inspect
+  inspect_escapy: escapy.inspect
diff --git a/benchmark/string_memsearch.yml b/benchmark/string_memsearch.yml
new file mode 100644
index 0000000000..cde363289a
--- /dev/null
+++ b/benchmark/string_memsearch.yml
@@ -0,0 +1,75 @@
+prelude: |
+  # Haystacks of various sizes
+  small_hay  = "a" * 256
+  medium_hay = "a" * 4096
+  large_hay  = "a" * 65536
+
+  # Short needles (2-8 bytes) that exercise rb_memsearch_ss
+  needle_2 = "xy"
+  needle_4 = "xyzw"
+  needle_8 = "xyzwabcd"
+
+  # Needle whose first byte is absent from the haystack (memchr fast-path)
+  # vs needle whose first byte is common (rolling hash comparison)
+  first_byte_absent  = "x" + "a" * 3
+  first_byte_common  = "a" + "x" * 3
+
+  # Haystack with match at the end
+  hay_match_end = "a" * 4095 + "xy"
+
+  # Haystack with match at the start
+  hay_match_start = "xy" + "a" * 4094
+
+  # Mixed content haystack (more realistic)
+  mixed_hay = (("abcdefghij" * 100) + "z") * 10
+
+benchmark:
+  # === First byte absent from haystack (biggest win for rolling hash) ===
+  index_first_byte_absent_small: |
+    small_hay.index(first_byte_absent)
+  index_first_byte_absent_medium: |
+    medium_hay.index(first_byte_absent)
+  index_first_byte_absent_large: |
+    large_hay.index(first_byte_absent)
+
+  # === First byte common in haystack (stresses comparison loop) ===
+  index_first_byte_common_small: |
+    small_hay.index(first_byte_common)
+  index_first_byte_common_medium: |
+    medium_hay.index(first_byte_common)
+  index_first_byte_common_large: |
+    large_hay.index(first_byte_common)
+
+  # === Needle length variations (all absent) ===
+  index_needle_2_absent: |
+    medium_hay.index(needle_2)
+  index_needle_4_absent: |
+    medium_hay.index(needle_4)
+  index_needle_8_absent: |
+    medium_hay.index(needle_8)
+
+  # === Match at end of haystack ===
+  index_match_at_end: |
+    hay_match_end.index(needle_2)
+
+  # === Match at start of haystack ===
+  index_match_at_start: |
+    hay_match_start.index(needle_2)
+
+  # === include? (same code path) ===
+  include_first_byte_absent: |
+    medium_hay.include?(first_byte_absent)
+  include_first_byte_common: |
+    medium_hay.include?(first_byte_common)
+
+  # === byteindex ===
+  byteindex_first_byte_absent: |
+    medium_hay.byteindex(first_byte_absent)
+  byteindex_first_byte_common: |
+    medium_hay.byteindex(first_byte_common)
+
+  # === Mixed/realistic haystack ===
+  index_mixed_absent: |
+    mixed_hay.index(needle_4)
+  index_mixed_present: |
+    mixed_hay.index("ijab")
diff --git a/benchmark/string_scrub.yml b/benchmark/string_scrub.yml
new file mode 100644
index 0000000000..4b5faaad8e
--- /dev/null
+++ b/benchmark/string_scrub.yml
@@ -0,0 +1,48 @@
+prelude: |
+
+  STRING_SIZE = 1024
+  def duplicate_to_length(str, target_length)
+    return "" if target_length <= 0
+    return str[0, target_length] if str.length >= target_length
+
+    (str * ((target_length / str.length) + 1))[0, target_length]
+  end
+  base = "Hello \u{1f600} world! \u{00e9}\u{00f1}"
+  padding = duplicate_to_length(base, STRING_SIZE)
+
+  valid_utf8 = (padding.b + "OK".b).force_encoding("UTF-8")
+  valid_utf8.valid_encoding?
+  unknown_but_valid_utf8 = valid_utf8.dup.b.force_encoding("UTF-8")
+  invalid_utf8 = (padding.b + "\x80\xFF".b).force_encoding("UTF-8")
+  invalid_utf8.valid_encoding?
+  unknown_but_invalid_utf8 = (padding.b + "\x80\xFF".b).force_encoding("UTF-8")
+
+  worst_case_utf8 = duplicate_to_length("\u{1f600}\u{00e9}\u{00f1}", STRING_SIZE).b.force_encoding("UTF-8")
+
+  unknown_but_valid_utf8_worst_case = worst_case_utf8.dup.b.force_encoding("UTF-8")
+  unknown_but_invalid_utf8_worst_case = (worst_case_utf8.b + "\x80\xFF".b).force_encoding("UTF-8")
+
+benchmark:
+  scrub_known_valid: |
+    string = valid_utf8.dup
+    string.scrub!
+
+  scrub_known_invalid: |
+    string = invalid_utf8.dup
+    string.scrub!
+
+  scrub_unknown_but_valid_coderange: |
+    string = unknown_but_valid_utf8.dup
+    string.scrub!
+
+  scrub_unknown_and_invalid_coderange: |
+    string = unknown_but_invalid_utf8.dup
+    string.scrub!
+
+  scrub_unknown_but_valid_coderange_worst_case: |
+    string = unknown_but_valid_utf8_worst_case.dup
+    string.scrub!
+
+  scrub_unknown_and_invalid_coderange_worst_case: |
+    string = unknown_but_invalid_utf8_worst_case.dup
+    string.scrub!
+\ No newline at end of file
diff --git a/benchmark/struct_accessor.yml b/benchmark/struct_accessor.yml
new file mode 100644
index 0000000000..d95240e2dd
--- /dev/null
+++ b/benchmark/struct_accessor.yml
@@ -0,0 +1,37 @@
+prelude: |
+  C = Struct.new(:x) do
+    def initialize(...)
+      super
+      @ivar = 42
+    end
+
+    attr_accessor :ivar
+
+    class_eval <<-END
+      def r
+        #{'x;'*256}
+      end
+      def w
+        #{'self.x = nil;'*256}
+      end
+      def rm
+        m = method(:x)
+        #{'m.call;'*256}
+      end
+      def wm
+        m = method(:x=)
+        #{'m.call(nil);'*256}
+      end
+      def r_ivar
+        #{'ivar;'*256}
+      end
+    END
+  end
+  C.new(nil) # ensure common shape is known
+  obj = C.new(nil)
+benchmark:
+  member_reader: "obj.r"
+  member_writer: "obj.w"
+  member_reader_method: "obj.rm"
+  member_writer_method: "obj.wm"
+  ivar_reader: "obj.r_ivar"
diff --git a/benchmark/time_now.yml b/benchmark/time_now.yml
index f6d6a31489..9336877cd4 100644
--- a/benchmark/time_now.yml
+++ b/benchmark/time_now.yml
@@ -1,3 +1,4 @@
 benchmark:
   - 'Time.now'
   - 'Time.now(in: "+09:00")'
+  - 'Time.now.year'
diff --git a/benchmark/time_strftime.yml b/benchmark/time_strftime.yml
new file mode 100644
index 0000000000..28f62aec87
--- /dev/null
+++ b/benchmark/time_strftime.yml
@@ -0,0 +1,7 @@
+prelude: |
+  # frozen_string_literal: true
+  time = Time.now
+benchmark:
+  - time.strftime("%FT%T")     # 19B
+  - time.strftime("%FT%T.%3N") # 23B
+  - time.strftime("%FT%T.%6N") # 26B
diff --git a/benchmark/time_xmlschema.yml b/benchmark/time_xmlschema.yml
new file mode 100644
index 0000000000..654e5cfcbc
--- /dev/null
+++ b/benchmark/time_xmlschema.yml
@@ -0,0 +1,27 @@
+prelude: |
+  # frozen_string_literal
+  unless Time.method_defined?(:xmlschema)
+    class Time
+      def xmlschema(fraction_digits=0)
+        fraction_digits = fraction_digits.to_i
+        s = strftime("%FT%T")
+        if fraction_digits > 0
+          s << strftime(".%#{fraction_digits}N")
+        end
+        s << (utc? ? 'Z' : strftime("%:z"))
+      end
+    end
+  end
+  time = Time.now
+  utc_time = Time.now.utc
+  fraction_sec = Time.at(123456789.quo(9999999999)).getlocal("+09:00")
+  future_time = Time.utc(10000)
+benchmark:
+  - time.xmlschema
+  - utc_time.xmlschema
+  - time.xmlschema(6)
+  - utc_time.xmlschema(6)
+  - time.xmlschema(9)
+  - utc_time.xmlschema(9)
+  - fraction_sec.xmlschema(10)
+  - future_time.xmlschema
diff --git a/benchmark/vm_call_kw_and_kw_splat.yml b/benchmark/vm_call_kw_and_kw_splat.yml
new file mode 100644
index 0000000000..aa6e549e0c
--- /dev/null
+++ b/benchmark/vm_call_kw_and_kw_splat.yml
@@ -0,0 +1,25 @@
+prelude: |
+  h1, h10, h100, h1000 = [1, 10, 100, 1000].map do |n|
+    h = {kw: 1}
+    n.times{|i| h[i.to_s.to_sym] = i}
+    h
+  end
+  eh = {}
+  def kw(kw: nil, **kws) end
+benchmark:
+  1: |
+    kw(**h1)
+  1_mutable: |
+    kw(**eh, **h1)
+  10: |
+    kw(**h10)
+  10_mutable: |
+    kw(**eh, **h10)
+  100: |
+    kw(**h100)
+  100_mutable: |
+    kw(**eh, **h100)
+  1000: |
+    kw(**h1000)
+  1000_mutable: |
+    kw(**eh, **h1000)
diff --git a/benchmark/vm_ivar_get.yml b/benchmark/vm_ivar_get.yml
index 9174af6965..1e0dad665f 100644
--- a/benchmark/vm_ivar_get.yml
+++ b/benchmark/vm_ivar_get.yml
@@ -1,17 +1,75 @@
 prelude: |
   class Example
     def initialize
+      @levar = 1
       @v0 = 1
       @v1 = 2
       @v3 = 3
+    end
+
+    def get_value_loop
+      sum = 0
+
+      i = 0
+      while i < 100_000
+        # 10 times to de-emphasize loop overhead
+        sum += @levar
+        sum += @levar
+        sum += @levar
+        sum += @levar
+        sum += @levar
+        sum += @levar
+        sum += @levar
+        sum += @levar
+        sum += @levar
+        sum += @levar
+        i += 1
+      end
+
+      return sum
+    end
+
+    @levar = 1
+    @v0 = 1
+    @v1 = 2
+    @v3 = 3
+
+    def self.get_value_loop
+      sum = 0
+
+      i = 0
+      while i < 100_000
+        # 10 times to de-emphasize loop overhead
+        sum += @levar
+        sum += @levar
+        sum += @levar
+        sum += @levar
+        sum += @levar
+        sum += @levar
+        sum += @levar
+        sum += @levar
+        sum += @levar
+        sum += @levar
+        i += 1
+      end
+
+      return sum
+    end
+  end
+
+  class GenExample < Time
+    def initialize
       @levar = 1
+      @v0 = 1
+      @v1 = 2
+      @v3 = 3
     end
 
     def get_value_loop
       sum = 0
 
       i = 0
-      while i < 1000000
+      while i < 100_000
         # 10 times to de-emphasize loop overhead
         sum += @levar
         sum += @levar
@@ -31,7 +89,12 @@ prelude: |
   end
 
   obj = Example.new
+  gen = GenExample.new
 benchmark:
-  vm_ivar_get: |
+  vm_ivar_get_on_obj: |
     obj.get_value_loop
+  vm_ivar_get_on_class: |
+    Example.get_value_loop
+  vm_ivar_get_on_generic: |
+    gen.get_value_loop
 loop_count: 100
diff --git a/benchmark/vm_ivar_ic_miss.yml b/benchmark/vm_ivar_ic_miss.yml
index f20ca7efac..944fb1a9e6 100644
--- a/benchmark/vm_ivar_ic_miss.yml
+++ b/benchmark/vm_ivar_ic_miss.yml
@@ -4,13 +4,13 @@ prelude: |
       if diverge
         @a = 1
       end
-  
+
       @a0 = @a1 = @a2 = @a3 = @a4 = @a5 = @a6 = @a7 = @a8 = @a9 = @a10 = @a11 = @a12 = @a13 = @a14 = @a15 = @a16 = @a17 = @a18 = @a19 = @a20 = @a21 = @a22 = @a23 = @a24 = @a25 = @a26 = @a27 = @a28 = @a29 = @a30 = @a31 = @a32 = @a33 = @a34 = @a35 = @a36 = @a37 = @a38 = @a39 = @a40 = @a41 = @a42 = @a43 = @a44 = @a45 = @a46 = @a47 = @a48 = @a49 = @a50 = @a51 = @a52 = @a53 = @a54 = @a55 = @a56 = @a57 = @a58 = @a59 = @a60 = @a61 = @a62 = @a63 = @a64 = @a65 = @a66 = @a67 = @a68 = @a69 = @a70 = @a71 = @a72 = @a73 = @a74 = @b = 1
     end
 
     def b; @b; end
   end
-  
+
   a = Foo.new false
   b = Foo.new true
 benchmark:
diff --git a/benchmark/vm_ivar_memoize.yml b/benchmark/vm_ivar_memoize.yml
new file mode 100644
index 0000000000..90f6b07f05
--- /dev/null
+++ b/benchmark/vm_ivar_memoize.yml
@@ -0,0 +1,85 @@
+prelude: |
+  IVARS = 60
+  class Record
+    def initialize(offset = false)
+      @offset = 1 if offset
+      @first = 0
+      IVARS.times do |i|
+        instance_variable_set("@ivar_#{i}", i)
+      end
+    end
+
+    def first
+      @first
+    end
+
+    def lazy_set
+      @lazy_set ||= 123
+    end
+
+    def undef
+      @undef
+    end
+  end
+
+  Record.new # Need one alloc to right size
+
+  BASE = Record.new
+  LAZY = Record.new
+  LAZY.lazy_set
+
+  class Miss < Record
+    @first = 0
+    IVARS.times do |i|
+      instance_variable_set("@i_#{i}", i)
+    end
+  end
+
+  Miss.new # Need one alloc to right size
+  MISS = Miss.new
+
+  DIVERGENT = Record.new(true)
+
+benchmark:
+  vm_ivar_stable_shape: |
+    BASE.first
+    BASE.first
+    BASE.first
+    BASE.first
+    BASE.first
+    BASE.first
+  vm_ivar_memoize_unstable_shape: |
+    BASE.first
+    LAZY.first
+    BASE.first
+    LAZY.first
+    BASE.first
+    LAZY.first
+  vm_ivar_memoize_unstable_shape_miss: |
+    BASE.first
+    MISS.first
+    BASE.first
+    MISS.first
+    BASE.first
+    MISS.first
+  vm_ivar_unstable_undef: |
+    BASE.undef
+    LAZY.undef
+    BASE.undef
+    LAZY.undef
+    BASE.undef
+    LAZY.undef
+  vm_ivar_divergent_shape: |
+    BASE.first
+    DIVERGENT.first
+    BASE.first
+    DIVERGENT.first
+    BASE.first
+    DIVERGENT.first
+  vm_ivar_divergent_shape_imbalanced: |
+    BASE.first
+    DIVERGENT.first
+    DIVERGENT.first
+    DIVERGENT.first
+    DIVERGENT.first
+    DIVERGENT.first
diff --git a/benchmark/vm_ivar_set_on_instance.yml b/benchmark/vm_ivar_set_on_instance.yml
index 91857b7742..6ce53a86ec 100644
--- a/benchmark/vm_ivar_set_on_instance.yml
+++ b/benchmark/vm_ivar_set_on_instance.yml
@@ -1,16 +1,44 @@
 prelude: |
   class TheClass
     def initialize
+      @levar = 1
       @v0 = 1
       @v1 = 2
       @v3 = 3
+    end
+
+    def set_value_loop
+      # 100k
+      i = 0
+      while i < 100_000
+        # 10 times to de-emphasize loop overhead
+        @levar = i
+        @levar = i
+        @levar = i
+        @levar = i
+        @levar = i
+        @levar = i
+        @levar = i
+        @levar = i
+        @levar = i
+        @levar = i
+        i += 1
+      end
+    end
+  end
+
+  class Generic < Time
+    def initialize
       @levar = 1
+      @v0 = 1
+      @v1 = 2
+      @v3 = 3
     end
 
     def set_value_loop
-      # 1M
+      # 100k
       i = 0
-      while i < 1000000
+      while i < 100_000
         # 10 times to de-emphasize loop overhead
         @levar = i
         @levar = i
@@ -28,8 +56,39 @@ prelude: |
   end
 
   obj = TheClass.new
+  gen_obj = Generic.new
+
+  class SomeClass
+    @levar = 1
+    @v0 = 1
+    @v1 = 2
+    @v3 = 3
+
+    def self.set_value_loop
+      # 100k
+      i = 0
+      while i < 100_000
+        # 10 times to de-emphasize loop overhead
+        @levar = i
+        @levar = i
+        @levar = i
+        @levar = i
+        @levar = i
+        @levar = i
+        @levar = i
+        @levar = i
+        @levar = i
+        @levar = i
+        i += 1
+      end
+    end
+  end
 
 benchmark:
   vm_ivar_set_on_instance: |
     obj.set_value_loop
+  vm_ivar_set_on_generic: |
+    gen_obj.set_value_loop
+  vm_ivar_set_on_class: |
+    SomeClass.set_value_loop
 loop_count: 100
diff --git a/benchmark/vm_method_splat_calls.yml b/benchmark/vm_method_splat_calls.yml
new file mode 100644
index 0000000000..f2f366e99c
--- /dev/null
+++ b/benchmark/vm_method_splat_calls.yml
@@ -0,0 +1,13 @@
+prelude: |
+  def f(x=0, y: 0) end
+  a = [1]
+  ea = []
+  kw = {y: 1}
+  b = lambda{}
+benchmark:
+  arg_splat: "f(1, *ea)"
+  arg_splat_block: "f(1, *ea, &b)"
+  splat_kw_splat: "f(*a, **kw)"
+  splat_kw_splat_block: "f(*a, **kw, &b)"
+  splat_kw: "f(*a, y: 1)"
+  splat_kw_block: "f(*a, y: 1, &b)"
diff --git a/benchmark/vm_method_splat_calls2.yml b/benchmark/vm_method_splat_calls2.yml
new file mode 100644
index 0000000000..d33dcd7e8b
--- /dev/null
+++ b/benchmark/vm_method_splat_calls2.yml
@@ -0,0 +1,27 @@
+prelude: |
+  def named_arg_splat(*a) end
+  def named_arg_kw_splat(*a, **kw) end
+  def anon_arg_splat(*) end
+  def anon_kw_splat(**) end
+  def anon_arg_kw_splat(*, **) end
+  def anon_fw_to_named(*, **) named_arg_kw_splat(*, **) end
+  def fw_to_named(...) named_arg_kw_splat(...) end
+  def fw_to_anon_to_named(...) anon_fw_to_named(...) end
+  def fw_no_kw(...) named_arg_splat(...) end
+  a = [1]
+  kw = {y: 1}
+benchmark:
+  named_multi_arg_splat: "named_arg_splat(*a, *a)"
+  named_post_splat: "named_arg_splat(*a, a)"
+  anon_arg_splat: "anon_arg_splat(*a)"
+  anon_arg_kw_splat: "anon_arg_kw_splat(*a, **kw)"
+  anon_multi_arg_splat: "anon_arg_splat(*a, *a)"
+  anon_post_splat: "anon_arg_splat(*a, a)"
+  anon_kw_splat: "anon_kw_splat(**kw)"
+  anon_fw_to_named_splat: "anon_fw_to_named(*a, **kw)"
+  anon_fw_to_named_no_splat: "anon_fw_to_named(1, y: 1)"
+  fw_to_named_splat: "fw_to_named(*a, **kw)"
+  fw_to_named_no_splat: "fw_to_named(1, y: 1)"
+  fw_to_anon_to_named_splat: "fw_to_anon_to_named(*a, **kw)"
+  fw_to_anon_to_named_no_splat: "fw_to_anon_to_named(1, y: 1)"
+  fw_no_kw: "fw_no_kw(1, 2)"
diff --git a/benchmark/vm_regexp.yml b/benchmark/vm_regexp.yml
index 2aa3d94dbd..80541332b1 100644
--- a/benchmark/vm_regexp.yml
+++ b/benchmark/vm_regexp.yml
@@ -3,6 +3,12 @@ prelude: |
 benchmark:
   vm_regexp: |
     /hoge/ =~ str
+  vm_regexp_alternating: |
+    /hoge/ =~ str
+    /huge/ =~ str
   vm_regexp_invert: |
     str =~ /hoge/
+  vm_regexp_invert_alternating: |
+    str =~ /hoge/
+    str =~ /huge/
 loop_count: 6000000
diff --git a/benchmark/vm_super_splat_calls.yml b/benchmark/vm_super_splat_calls.yml
new file mode 100644
index 0000000000..795e44e4da
--- /dev/null
+++ b/benchmark/vm_super_splat_calls.yml
@@ -0,0 +1,25 @@
+prelude: |
+  @a = [1].freeze
+  @ea = [].freeze
+  @kw = {y: 1}.freeze
+  @b = lambda{}
+  extend(Module.new{def arg_splat(x=0, y: 0) end})
+  extend(Module.new{def arg_splat_block(x=0, y: 0) end})
+  extend(Module.new{def splat_kw_splat(x=0, y: 0) end})
+  extend(Module.new{def splat_kw_splat_block(x=0, y: 0) end})
+  extend(Module.new{def splat_kw(x=0, y: 0) end})
+  extend(Module.new{def splat_kw_block(x=0, y: 0) end})
+
+  extend(Module.new{def arg_splat; super(1, *@ea) end})
+  extend(Module.new{def arg_splat_block; super(1, *@ea, &@b) end})
+  extend(Module.new{def splat_kw_splat; super(*@a, **@kw) end})
+  extend(Module.new{def splat_kw_splat_block; super(*@a, **@kw, &@b) end})
+  extend(Module.new{def splat_kw; super(*@a, y: 1) end})
+  extend(Module.new{def splat_kw_block; super(*@a, y: 1, &@b) end})
+benchmark:
+  arg_splat: "arg_splat"
+  arg_splat_block: "arg_splat_block"
+  splat_kw_splat: "splat_kw_splat"
+  splat_kw_splat_block: "splat_kw_splat_block"
+  splat_kw: "splat_kw"
+  splat_kw_block: "splat_kw_block"
diff --git a/benchmark/vm_zsuper_splat_calls.yml b/benchmark/vm_zsuper_splat_calls.yml
new file mode 100644
index 0000000000..82dc22349d
--- /dev/null
+++ b/benchmark/vm_zsuper_splat_calls.yml
@@ -0,0 +1,28 @@
+prelude: |
+  a = [1].freeze
+  ea = [].freeze
+  kw = {y: 1}.freeze
+  b = lambda{}
+  extend(Module.new{def arg_splat(x=0, y: 0) end})
+  extend(Module.new{def arg_splat_block(x=0, y: 0) end})
+  extend(Module.new{def arg_splat_post(x=0, y: 0) end})
+  extend(Module.new{def splat_kw_splat(x=0, y: 0) end})
+  extend(Module.new{def splat_kw_splat_block(x=0, y: 0) end})
+  extend(Module.new{def splat_kw(x=0, y: 0) end})
+  extend(Module.new{def splat_kw_block(x=0, y: 0) end})
+
+  extend(Module.new{def arg_splat(x, *a) super end})
+  extend(Module.new{def arg_splat_block(x, *a, &b) super end})
+  extend(Module.new{def arg_splat_post(*a, x) super end})
+  extend(Module.new{def splat_kw_splat(*a, **kw) super end})
+  extend(Module.new{def splat_kw_splat_block(*a, **kw, &b) super end})
+  extend(Module.new{def splat_kw(*a, y: 1) super end})
+  extend(Module.new{def splat_kw_block(*a, y: 1, &b) super end})
+benchmark:
+  arg_splat: "arg_splat(1, *ea)"
+  arg_splat_block: "arg_splat_block(1, *ea, &b)"
+  arg_splat_post: "arg_splat_post(1, *ea, &b)"
+  splat_kw_splat: "splat_kw_splat(*a, **kw)"
+  splat_kw_splat_block: "splat_kw_splat_block(*a, **kw, &b)"
+  splat_kw: "splat_kw(*a, y: 1)"
+  splat_kw_block: "splat_kw_block(*a, y: 1, &b)"
diff --git a/bignum.c b/bignum.c
index e9bf37d206..28924b4eb9 100644
--- a/bignum.c
+++ b/bignum.c
@@ -30,9 +30,6 @@
 # define USE_GMP 0
 #endif
 #endif
-#if USE_GMP
-# include <gmp.h>
-#endif
 
 #include "id.h"
 #include "internal.h"
@@ -48,6 +45,15 @@
 #include "ruby/util.h"
 #include "ruby_assert.h"
 
+#if USE_GMP
+RBIMPL_WARNING_PUSH()
+# ifdef _MSC_VER
+RBIMPL_WARNING_IGNORED(4146) /* for mpn_neg() */
+# endif
+# include <gmp.h>
+RBIMPL_WARNING_POP()
+#endif
+
 static const bool debug_integer_pack = (
 #ifdef DEBUG_INTEGER_PACK
     DEBUG_INTEGER_PACK+0
@@ -58,6 +64,21 @@ static const bool debug_integer_pack = (
 
 const char ruby_digitmap[] = "0123456789abcdefghijklmnopqrstuvwxyz";
 
+/* Two-digit decimal lookup table.  Offset 2*n holds the ASCII pair for
+ * n in the range 0..99.  Used by both rb_fix2str in numeric.c and
+ * big2str_2bdigits below to emit two base-10 digits per iteration. */
+const char ruby_decimal_digit_pairs[201] =
+    "00010203040506070809"
+    "10111213141516171819"
+    "20212223242526272829"
+    "30313233343536373839"
+    "40414243444546474849"
+    "50515253545556575859"
+    "60616263646566676869"
+    "70717273747576777879"
+    "80818283848586878889"
+    "90919293949596979899";
+
 #ifndef SIZEOF_BDIGIT_DBL
 # if SIZEOF_INT*2 <= SIZEOF_LONG_LONG
 #  define SIZEOF_BDIGIT_DBL SIZEOF_LONG_LONG
@@ -73,7 +94,6 @@ STATIC_ASSERT(sizeof_bdigit_and_dbl, SIZEOF_BDIGIT*2 <= SIZEOF_BDIGIT_DBL);
 STATIC_ASSERT(bdigit_signedness, 0 < (BDIGIT)-1);
 STATIC_ASSERT(bdigit_dbl_signedness, 0 < (BDIGIT_DBL)-1);
 STATIC_ASSERT(bdigit_dbl_signed_signedness, 0 > (BDIGIT_DBL_SIGNED)-1);
-STATIC_ASSERT(rbignum_embed_len_max, BIGNUM_EMBED_LEN_MAX <= (BIGNUM_EMBED_LEN_MASK >> BIGNUM_EMBED_LEN_SHIFT));
 
 #if SIZEOF_BDIGIT < SIZEOF_LONG
 STATIC_ASSERT(sizeof_long_and_sizeof_bdigit, SIZEOF_LONG % SIZEOF_BDIGIT == 0);
@@ -349,7 +369,7 @@ maxpow_in_bdigit_dbl(int base, int *exp_ret)
     BDIGIT_DBL maxpow;
     int exponent;
 
-    assert(2 <= base && base <= 36);
+    RUBY_ASSERT(2 <= base && base <= 36);
 
     {
 #if SIZEOF_BDIGIT_DBL == 2
@@ -381,7 +401,7 @@ maxpow_in_bdigit_dbl(int base, int *exp_ret)
 static inline BDIGIT_DBL
 bary2bdigitdbl(const BDIGIT *ds, size_t n)
 {
-    assert(n <= 2);
+    RUBY_ASSERT(n <= 2);
 
     if (n == 2)
         return ds[0] | BIGUP(ds[1]);
@@ -393,7 +413,7 @@ bary2bdigitdbl(const BDIGIT *ds, size_t n)
 static inline void
 bdigitdbl2bary(BDIGIT *ds, size_t n, BDIGIT_DBL num)
 {
-    assert(n == 2);
+    RUBY_ASSERT(n == 2);
 
     ds[0] = BIGLO(num);
     ds[1] = (BDIGIT)BIGDN(num);
@@ -424,7 +444,7 @@ bary_small_lshift(BDIGIT *zds, const BDIGIT *xds, size_t n, int shift)
 {
     size_t i;
     BDIGIT_DBL num = 0;
-    assert(0 <= shift && shift < BITSPERDIG);
+    RUBY_ASSERT(0 <= shift && shift < BITSPERDIG);
 
     for (i=0; i<n; i++) {
         num = num | (BDIGIT_DBL)*xds++ << shift;
@@ -440,7 +460,7 @@ bary_small_rshift(BDIGIT *zds, const BDIGIT *xds, size_t n, int shift, BDIGIT hi
     size_t i;
     BDIGIT_DBL num = 0;
 
-    assert(0 <= shift && shift < BITSPERDIG);
+    RUBY_ASSERT(0 <= shift && shift < BITSPERDIG);
 
     num = BIGUP(higher_bdigit);
     for (i = 0; i < n; i++) {
@@ -1060,8 +1080,8 @@ integer_unpack_num_bdigits(size_t numwords, size_t wordsize, size_t nails, int *
         if (debug_integer_pack) {
             int nlp_bits1;
             size_t num_bdigits1 = integer_unpack_num_bdigits_generic(numwords, wordsize, nails, &nlp_bits1);
-            assert(num_bdigits == num_bdigits1);
-            assert(*nlp_bits_ret == nlp_bits1);
+            RUBY_ASSERT(num_bdigits == num_bdigits1);
+            RUBY_ASSERT(*nlp_bits_ret == nlp_bits1);
             (void)num_bdigits1;
         }
     }
@@ -1271,7 +1291,7 @@ bary_unpack_internal(BDIGIT *bdigits, size_t num_bdigits, const void *words, siz
         }
         if (dd)
             *dp++ = (BDIGIT)dd;
-        assert(dp <= de);
+        RUBY_ASSERT(dp <= de);
         while (dp < de)
             *dp++ = 0;
 #undef PUSH_BITS
@@ -1330,7 +1350,7 @@ bary_unpack(BDIGIT *bdigits, size_t num_bdigits, const void *words, size_t numwo
 
     num_bdigits0 = integer_unpack_num_bdigits(numwords, wordsize, nails, &nlp_bits);
 
-    assert(num_bdigits0 <= num_bdigits);
+    RUBY_ASSERT(num_bdigits0 <= num_bdigits);
 
     sign = bary_unpack_internal(bdigits, num_bdigits0, words, numwords, wordsize, nails, flags, nlp_bits);
 
@@ -1349,8 +1369,8 @@ bary_subb(BDIGIT *zds, size_t zn, const BDIGIT *xds, size_t xn, const BDIGIT *yd
     size_t i;
     size_t sn;
 
-    assert(xn <= zn);
-    assert(yn <= zn);
+    RUBY_ASSERT(xn <= zn);
+    RUBY_ASSERT(yn <= zn);
 
     sn = xn < yn ? xn : yn;
 
@@ -1411,8 +1431,8 @@ bary_addc(BDIGIT *zds, size_t zn, const BDIGIT *xds, size_t xn, const BDIGIT *yd
     BDIGIT_DBL num;
     size_t i;
 
-    assert(xn <= zn);
-    assert(yn <= zn);
+    RUBY_ASSERT(xn <= zn);
+    RUBY_ASSERT(yn <= zn);
 
     if (xn > yn) {
         const BDIGIT *tds;
@@ -1476,7 +1496,7 @@ bary_mul_single(BDIGIT *zds, size_t zn, BDIGIT x, BDIGIT y)
 {
     BDIGIT_DBL n;
 
-    assert(2 <= zn);
+    RUBY_ASSERT(2 <= zn);
 
     n = (BDIGIT_DBL)x * y;
     bdigitdbl2bary(zds, 2, n);
@@ -1490,7 +1510,7 @@ bary_muladd_1xN(BDIGIT *zds, size_t zn, BDIGIT x, const BDIGIT *yds, size_t yn)
     BDIGIT_DBL dd;
     size_t j;
 
-    assert(zn > yn);
+    RUBY_ASSERT(zn > yn);
 
     if (x == 0)
         return 0;
@@ -1525,7 +1545,7 @@ bigdivrem_mulsub(BDIGIT *zds, size_t zn, BDIGIT x, const BDIGIT *yds, size_t yn)
     BDIGIT_DBL t2;
     BDIGIT_DBL_SIGNED num;
 
-    assert(zn == yn + 1);
+    RUBY_ASSERT(zn == yn + 1);
 
     num = 0;
     t2 = 0;
@@ -1550,7 +1570,7 @@ bary_mulsub_1xN(BDIGIT *zds, size_t zn, BDIGIT x, const BDIGIT *yds, size_t yn)
 {
     BDIGIT_DBL_SIGNED num;
 
-    assert(zn == yn + 1);
+    RUBY_ASSERT(zn == yn + 1);
 
     num = bigdivrem_mulsub(zds, zn, x, yds, yn);
     zds[yn] = BIGLO(num);
@@ -1564,7 +1584,7 @@ bary_mul_normal(BDIGIT *zds, size_t zn, const BDIGIT *xds, size_t xn, const BDIG
 {
     size_t i;
 
-    assert(xn + yn <= zn);
+    RUBY_ASSERT(xn + yn <= zn);
 
     BDIGITS_ZERO(zds, zn);
     for (i = 0; i < xn; i++) {
@@ -1595,7 +1615,7 @@ bary_sq_fast(BDIGIT *zds, size_t zn, const BDIGIT *xds, size_t xn)
     BDIGIT vl;
     int vh;
 
-    assert(xn * 2 <= zn);
+    RUBY_ASSERT(xn * 2 <= zn);
 
     BDIGITS_ZERO(zds, zn);
 
@@ -1667,9 +1687,9 @@ bary_mul_balance_with_mulfunc(BDIGIT *const zds, const size_t zn,
     VALUE work = 0;
     size_t n;
 
-    assert(xn + yn <= zn);
-    assert(xn <= yn);
-    assert(!KARATSUBA_BALANCED(xn, yn) || !TOOM3_BALANCED(xn, yn));
+    RUBY_ASSERT(xn + yn <= zn);
+    RUBY_ASSERT(xn <= yn);
+    RUBY_ASSERT(!KARATSUBA_BALANCED(xn, yn) || !TOOM3_BALANCED(xn, yn));
 
     BDIGITS_ZERO(zds, xn);
 
@@ -1751,9 +1771,9 @@ bary_mul_karatsuba(BDIGIT *zds, size_t zn, const BDIGIT *xds, size_t xn, const B
     const BDIGIT *xds0, *xds1, *yds0, *yds1;
     BDIGIT *zds0, *zds1, *zds2, *zds3;
 
-    assert(xn + yn <= zn);
-    assert(xn <= yn);
-    assert(yn < 2 * xn);
+    RUBY_ASSERT(xn + yn <= zn);
+    RUBY_ASSERT(xn <= yn);
+    RUBY_ASSERT(yn < 2 * xn);
 
     sq = xds == yds && xn == yn;
 
@@ -1768,7 +1788,7 @@ bary_mul_karatsuba(BDIGIT *zds, size_t zn, const BDIGIT *xds, size_t xn, const B
 
     n = yn / 2;
 
-    assert(n < xn);
+    RUBY_ASSERT(n < xn);
 
     if (wn < n) {
         /* This function itself needs only n BDIGITs for work area.
@@ -1889,7 +1909,7 @@ bary_mul_karatsuba(BDIGIT *zds, size_t zn, const BDIGIT *xds, size_t xn, const B
         for (x = 0, i = xn-1; 0 <= i; i--) { x <<= SIZEOF_BDIGIT*CHAR_BIT; x |= xds[i]; }
         for (y = 0, i = yn-1; 0 <= i; i--) { y <<= SIZEOF_BDIGIT*CHAR_BIT; y |= yds[i]; }
         for (z = 0, i = zn-1; 0 <= i; i--) { z <<= SIZEOF_BDIGIT*CHAR_BIT; z |= zds[i]; }
-        assert(z == x * y);
+        RUBY_ASSERT(z == x * y);
     }
     */
 
@@ -1957,11 +1977,11 @@ bary_mul_toom3(BDIGIT *zds, size_t zn, const BDIGIT *xds, size_t xn, const BDIGI
 
     int sq = xds == yds && xn == yn;
 
-    assert(xn <= yn);  /* assume y >= x */
-    assert(xn + yn <= zn);
+    RUBY_ASSERT(xn <= yn);  /* assume y >= x */
+    RUBY_ASSERT(xn + yn <= zn);
 
     n = (yn + 2) / 3;
-    assert(2*n < xn);
+    RUBY_ASSERT(2*n < xn);
 
     wnc = 0;
 
@@ -2148,19 +2168,19 @@ bary_mul_toom3(BDIGIT *zds, size_t zn, const BDIGIT *xds, size_t xn, const BDIGI
     /* z(1) : t1 <- u1 * v1 */
     bary_mul_toom3_start(t1ds, t1n, u1ds, u1n, v1ds, v1n, wds, wn);
     t1p = u1p == v1p;
-    assert(t1ds[t1n-1] == 0);
+    RUBY_ASSERT(t1ds[t1n-1] == 0);
     t1n--;
 
     /* z(-1) : t2 <- u2 * v2 */
     bary_mul_toom3_start(t2ds, t2n, u2ds, u2n, v2ds, v2n, wds, wn);
     t2p = u2p == v2p;
-    assert(t2ds[t2n-1] == 0);
+    RUBY_ASSERT(t2ds[t2n-1] == 0);
     t2n--;
 
     /* z(-2) : t3 <- u3 * v3 */
     bary_mul_toom3_start(t3ds, t3n, u3ds, u3n, v3ds, v3n, wds, wn);
     t3p = u3p == v3p;
-    assert(t3ds[t3n-1] == 0);
+    RUBY_ASSERT(t3ds[t3n-1] == 0);
     t3n--;
 
     /* z(inf) : t4 <- x2 * y2 */
@@ -2336,7 +2356,7 @@ bary_mul_gmp(BDIGIT *zds, size_t zn, const BDIGIT *xds, size_t xn, const BDIGIT
     mpz_t x, y, z;
     size_t count;
 
-    assert(xn + yn <= zn);
+    RUBY_ASSERT(xn + yn <= zn);
 
     mpz_init(x);
     mpz_init(y);
@@ -2371,7 +2391,7 @@ rb_big_mul_gmp(VALUE x, VALUE y)
 static void
 bary_short_mul(BDIGIT *zds, size_t zn, const BDIGIT *xds, size_t xn, const BDIGIT *yds, size_t yn)
 {
-    assert(xn + yn <= zn);
+    RUBY_ASSERT(xn + yn <= zn);
 
     if (xn == 1 && yn == 1) {
         bary_mul_single(zds, zn, xds[0], yds[0]);
@@ -2407,7 +2427,7 @@ bary_mul_precheck(BDIGIT **zdsp, size_t *znp, const BDIGIT **xdsp, size_t *xnp,
     const BDIGIT *yds = *ydsp;
     size_t yn = *ynp;
 
-    assert(xn + yn <= zn);
+    RUBY_ASSERT(xn + yn <= zn);
 
     nlsz = 0;
 
@@ -2456,7 +2476,7 @@ bary_mul_precheck(BDIGIT **zdsp, size_t *znp, const BDIGIT **xdsp, size_t *xnp,
         tds = xds; xds = yds; yds = tds;
         tn = xn; xn = yn; yn = tn;
     }
-    assert(xn <= yn);
+    RUBY_ASSERT(xn <= yn);
 
     if (xn <= 1) {
         if (xn == 0) {
@@ -2639,8 +2659,8 @@ rb_big_stop(void *ptr)
 static BDIGIT
 bigdivrem_single1(BDIGIT *qds, const BDIGIT *xds, size_t xn, BDIGIT x_higher_bdigit, BDIGIT y)
 {
-    assert(0 < xn);
-    assert(x_higher_bdigit < y);
+    RUBY_ASSERT(0 < xn);
+    RUBY_ASSERT(x_higher_bdigit < y);
     if (POW2_P(y)) {
         BDIGIT r;
         r = xds[0] & (y-1);
@@ -2672,9 +2692,9 @@ bigdivrem_restoring(BDIGIT *zds, size_t zn, BDIGIT *yds, size_t yn)
     struct big_div_struct bds;
     size_t ynzero;
 
-    assert(yn < zn);
-    assert(BDIGIT_MSB(yds[yn-1]));
-    assert(zds[zn-1] < yds[yn-1]);
+    RUBY_ASSERT(yn < zn);
+    RUBY_ASSERT(BDIGIT_MSB(yds[yn-1]));
+    RUBY_ASSERT(zds[zn-1] < yds[yn-1]);
 
     for (ynzero = 0; !yds[ynzero]; ynzero++);
 
@@ -2693,7 +2713,7 @@ bigdivrem_restoring(BDIGIT *zds, size_t zn, BDIGIT *yds, size_t yn)
     if (bds.zn > 10000 || bds.yn > 10000) {
       retry:
         bds.stop = Qfalse;
-        rb_nogvl(bigdivrem1, &bds, rb_big_stop, &bds, RB_NOGVL_UBF_ASYNC_SAFE);
+        rb_nogvl(bigdivrem1, &bds, rb_big_stop, &bds, RB_NOGVL_UBF_ASYNC_SAFE | RB_NOGVL_OFFLOAD_SAFE);
 
         if (bds.stop == Qtrue) {
             /* execute trap handler, but exception was not raised. */
@@ -2713,9 +2733,9 @@ bary_divmod_normal(BDIGIT *qds, size_t qn, BDIGIT *rds, size_t rn, const BDIGIT
     size_t zn;
     VALUE tmpyz = 0;
 
-    assert(yn < xn || (xn == yn && yds[yn - 1] <= xds[xn - 1]));
-    assert(qds ? (xn - yn + 1) <= qn : 1);
-    assert(rds ? yn <= rn : 1);
+    RUBY_ASSERT(yn < xn || (xn == yn && yds[yn - 1] <= xds[xn - 1]));
+    RUBY_ASSERT(qds ? (xn - yn + 1) <= qn : 1);
+    RUBY_ASSERT(rds ? yn <= rn : 1);
 
     zn = xn + BIGDIVREM_EXTRA_WORDS;
 
@@ -2807,10 +2827,10 @@ bary_divmod_gmp(BDIGIT *qds, size_t qn, BDIGIT *rds, size_t rn, const BDIGIT *xd
     mpz_t x, y, q, r;
     size_t count;
 
-    assert(yn < xn || (xn == yn && yds[yn - 1] <= xds[xn - 1]));
-    assert(qds ? (xn - yn + 1) <= qn : 1);
-    assert(rds ? yn <= rn : 1);
-    assert(qds || rds);
+    RUBY_ASSERT(yn < xn || (xn == yn && yds[yn - 1] <= xds[xn - 1]));
+    RUBY_ASSERT(qds ? (xn - yn + 1) <= qn : 1);
+    RUBY_ASSERT(rds ? yn <= rn : 1);
+    RUBY_ASSERT(qds || rds);
 
     mpz_init(x);
     mpz_init(y);
@@ -2896,8 +2916,8 @@ bary_divmod_branch(BDIGIT *qds, size_t qn, BDIGIT *rds, size_t rn, const BDIGIT
 static void
 bary_divmod(BDIGIT *qds, size_t qn, BDIGIT *rds, size_t rn, const BDIGIT *xds, size_t xn, const BDIGIT *yds, size_t yn)
 {
-    assert(xn <= qn);
-    assert(yn <= rn);
+    RUBY_ASSERT(xn <= qn);
+    RUBY_ASSERT(yn <= rn);
 
     BARY_TRUNC(yds, yn);
     if (yn == 0)
@@ -2938,11 +2958,6 @@ bary_divmod(BDIGIT *qds, size_t qn, BDIGIT *rds, size_t rn, const BDIGIT *xds, s
     }
 }
 
-
-#ifndef BIGNUM_DEBUG
-# define BIGNUM_DEBUG (0+RUBY_DEBUG)
-#endif
-
 static int
 bigzero_p(VALUE x)
 {
@@ -2959,7 +2974,7 @@ int
 rb_cmpint(VALUE val, VALUE a, VALUE b)
 {
     if (NIL_P(val)) {
-        rb_cmperr(a, b);
+        rb_cmperr_reason(a, b, "comparator returned nil");
     }
     if (FIXNUM_P(val)) {
         long l = FIX2LONG(val);
@@ -2984,36 +2999,68 @@ rb_cmpint(VALUE val, VALUE a, VALUE b)
             ((l) << BIGNUM_EMBED_LEN_SHIFT)) : \
      (void)(RBIGNUM(b)->as.heap.len = (l)))
 
+static size_t
+big_embed_capa(VALUE big)
+{
+    size_t size = rb_gc_obj_slot_size(big) - offsetof(struct RBignum, as.ary);
+    RUBY_ASSERT(size % sizeof(BDIGIT) == 0);
+    size_t capa = size / sizeof(BDIGIT);
+    RUBY_ASSERT(capa <= BIGNUM_EMBED_LEN_MAX);
+    return capa;
+}
+
+static size_t
+big_embed_size(size_t capa)
+{
+    size_t size = offsetof(struct RBignum, as.ary) + (sizeof(BDIGIT) * capa);
+    if (size < sizeof(struct RBignum)) {
+        size = sizeof(struct RBignum);
+    }
+    return size;
+}
+
+static bool
+big_embeddable_p(size_t capa)
+{
+    if (capa > BIGNUM_EMBED_LEN_MAX) {
+        return false;
+    }
+    return rb_gc_size_allocatable_p(big_embed_size(capa));
+}
+
 static void
 rb_big_realloc(VALUE big, size_t len)
 {
     BDIGIT *ds;
+    size_t embed_capa = big_embed_capa(big);
+
     if (BIGNUM_EMBED_P(big)) {
-        if (BIGNUM_EMBED_LEN_MAX < len) {
+        if (embed_capa < len) {
             ds = ALLOC_N(BDIGIT, len);
-            MEMCPY(ds, RBIGNUM(big)->as.ary, BDIGIT, BIGNUM_EMBED_LEN_MAX);
+            MEMCPY(ds, RBIGNUM(big)->as.ary, BDIGIT, embed_capa);
             RBIGNUM(big)->as.heap.len = BIGNUM_LEN(big);
             RBIGNUM(big)->as.heap.digits = ds;
             FL_UNSET_RAW(big, BIGNUM_EMBED_FLAG);
         }
     }
     else {
-        if (len <= BIGNUM_EMBED_LEN_MAX) {
+        if (len <= embed_capa) {
             ds = RBIGNUM(big)->as.heap.digits;
+            size_t old_len = RBIGNUM(big)->as.heap.len;
             FL_SET_RAW(big, BIGNUM_EMBED_FLAG);
             BIGNUM_SET_LEN(big, len);
-            (void)VALGRIND_MAKE_MEM_UNDEFINED((void*)RBIGNUM(big)->as.ary, sizeof(RBIGNUM(big)->as.ary));
+            (void)VALGRIND_MAKE_MEM_UNDEFINED((void*)RBIGNUM(big)->as.ary, embed_capa * sizeof(BDIGIT));
             if (ds) {
                 MEMCPY(RBIGNUM(big)->as.ary, ds, BDIGIT, len);
-                xfree(ds);
+                SIZED_FREE_N(ds, old_len);
             }
         }
         else {
             if (BIGNUM_LEN(big) == 0) {
                 RBIGNUM(big)->as.heap.digits = ALLOC_N(BDIGIT, len);
             }
-            else {
-                REALLOC_N(RBIGNUM(big)->as.heap.digits, BDIGIT, len);
+            else if (BIGNUM_LEN(big) != len) {
+                SIZED_REALLOC_N(RBIGNUM(big)->as.heap.digits, BDIGIT, len, BIGNUM_LEN(big));
             }
         }
     }
@@ -3029,16 +3076,21 @@ rb_big_resize(VALUE big, size_t len)
 static VALUE
 bignew_1(VALUE klass, size_t len, int sign)
 {
-    NEWOBJ_OF(big, struct RBignum, klass,
-            T_BIGNUM | (RGENGC_WB_PROTECTED_BIGNUM ? FL_WB_PROTECTED : 0), sizeof(struct RBignum), 0);
-    VALUE bigv = (VALUE)big;
-    BIGNUM_SET_SIGN(bigv, sign);
-    if (len <= BIGNUM_EMBED_LEN_MAX) {
-        FL_SET_RAW(bigv, BIGNUM_EMBED_FLAG);
+    VALUE bigv;
+
+    if (big_embeddable_p(len)) {
+        size_t size = big_embed_size(len);
+        RUBY_ASSERT(rb_gc_size_allocatable_p(size));
+        NEWOBJ_OF(big, struct RBignum, klass, T_BIGNUM | BIGNUM_EMBED_FLAG, size);
+        bigv = (VALUE)big;
+        BIGNUM_SET_SIGN(bigv, sign);
         BIGNUM_SET_LEN(bigv, len);
-        (void)VALGRIND_MAKE_MEM_UNDEFINED((void*)big->as.ary, sizeof(big->as.ary));
+        (void)VALGRIND_MAKE_MEM_UNDEFINED((void*)big->as.ary, len * sizeof(BDIGIT));
     }
     else {
+        NEWOBJ_OF(big, struct RBignum, klass, T_BIGNUM, sizeof(struct RBignum));
+        bigv = (VALUE)big;
+        BIGNUM_SET_SIGN(bigv, sign);
         big->as.heap.digits = ALLOC_N(BDIGIT, len);
         big->as.heap.len = len;
     }
@@ -3049,7 +3101,9 @@ bignew_1(VALUE klass, size_t len, int sign)
 VALUE
 rb_big_new(size_t len, int sign)
 {
-    return bignew(len, sign != 0);
+    VALUE obj = bignew(len, sign != 0);
+    memset(BIGNUM_DIGITS(obj), 0, len * sizeof(BDIGIT));
+    return obj;
 }
 
 VALUE
@@ -3432,8 +3486,8 @@ rb_absint_numwords(VALUE val, size_t word_numbits, size_t *nlz_bits_ret)
         if (debug_integer_pack) {
             size_t numwords0, nlz_bits0;
             numwords0 = absint_numwords_generic(numbytes, nlz_bits_in_msbyte, word_numbits, &nlz_bits0);
-            assert(numwords0 == numwords);
-            assert(nlz_bits0 == nlz_bits);
+            RUBY_ASSERT(numwords0 == numwords);
+            RUBY_ASSERT(nlz_bits0 == nlz_bits);
             (void)numwords0;
         }
     }
@@ -3848,7 +3902,7 @@ str2big_poweroftwo(
     if (numbits) {
         *dp++ = BIGLO(dd);
     }
-    assert((size_t)(dp - BDIGITS(z)) == num_bdigits);
+    RUBY_ASSERT((size_t)(dp - BDIGITS(z)) == num_bdigits);
 
     return z;
 }
@@ -3891,7 +3945,7 @@ str2big_normal(
             }
             break;
         }
-        assert(blen <= num_bdigits);
+        RUBY_ASSERT(blen <= num_bdigits);
     }
 
     return z;
@@ -3949,7 +4003,7 @@ str2big_karatsuba(
             current_base = 1;
         }
     }
-    assert(i == num_bdigits);
+    RUBY_ASSERT(i == num_bdigits);
     for (unit = 2; unit < num_bdigits; unit *= 2) {
         for (i = 0; i < num_bdigits; i += unit*2) {
             if (2*unit <= num_bdigits - i) {
@@ -4094,8 +4148,8 @@ rb_int_parse_cstr(const char *str, ssize_t len, char **endp, size_t *ndigits,
         len -= (n); \
     } while (0)
 #define ASSERT_LEN() do {\
-        assert(len != 0); \
-        if (len0 >= 0) assert(s + len0 == str + len); \
+        RUBY_ASSERT(len != 0); \
+        if (len0 >= 0) RUBY_ASSERT(s + len0 == str + len); \
     } while (0)
 
     if (!str) {
@@ -4469,7 +4523,7 @@ rb_str2big_gmp(VALUE arg, int base, int badcheck)
 
 #if HAVE_LONG_LONG
 
-static VALUE
+VALUE
 rb_ull2big(unsigned LONG_LONG n)
 {
     long i;
@@ -4491,7 +4545,7 @@ rb_ull2big(unsigned LONG_LONG n)
     return big;
 }
 
-static VALUE
+VALUE
 rb_ll2big(LONG_LONG n)
 {
     long neg = 0;
@@ -4529,7 +4583,7 @@ rb_ll2inum(LONG_LONG n)
 #endif  /* HAVE_LONG_LONG */
 
 #ifdef HAVE_INT128_T
-static VALUE
+VALUE
 rb_uint128t2big(uint128_t n)
 {
     long i;
@@ -4640,8 +4694,8 @@ big_shift2(VALUE x, int lshift_p, VALUE y)
     size_t shift_numdigits;
     int shift_numbits;
 
-    assert(POW2_P(CHAR_BIT));
-    assert(POW2_P(BITSPERDIG));
+    RUBY_ASSERT(POW2_P(CHAR_BIT));
+    RUBY_ASSERT(POW2_P(BITSPERDIG));
 
     if (BIGZEROP(x))
         return INT2FIX(0);
@@ -4728,7 +4782,7 @@ power_cache_get_power(int base, int power_level, size_t *numdigits_ret)
         rb_obj_hide(power);
         base36_power_cache[base - 2][power_level] = power;
         base36_numdigits_cache[base - 2][power_level] = numdigits;
-        rb_gc_register_mark_object(power);
+        rb_vm_register_global_object(power);
     }
     if (numdigits_ret)
         *numdigits_ret = base36_numdigits_cache[base - 2][power_level];
@@ -4764,7 +4818,7 @@ big2str_2bdigits(struct big2str_struct *b2s, BDIGIT *xds, size_t xn, size_t tail
     int beginning = !b2s->ptr;
     size_t len = 0;
 
-    assert(xn <= 2);
+    RUBY_ASSERT(xn <= 2);
     num = bary2bdigitdbl(xds, xn);
 
     if (beginning) {
@@ -4772,11 +4826,34 @@ big2str_2bdigits(struct big2str_struct *b2s, BDIGIT *xds, size_t xn, size_t tail
             return;
         p = buf;
         j = sizeof(buf);
-        do {
-            BDIGIT_DBL idx = num % b2s->base;
-            num /= b2s->base;
-            p[--j] = ruby_digitmap[idx];
-        } while (num);
+        if (b2s->base == 10) {
+            /* Emit two decimal digits per iteration from ruby_decimal_digit_pairs.
+             * See the comment on the table in bignum.c near ruby_digitmap. */
+            while (num >= 100) {
+                BDIGIT_DBL idx = (num % 100) * 2;
+                num /= 100;
+                j -= 2;
+                p[j]     = ruby_decimal_digit_pairs[idx];
+                p[j + 1] = ruby_decimal_digit_pairs[idx + 1];
+            }
+            if (num >= 10) {
+                BDIGIT_DBL idx = num * 2;
+                j -= 2;
+                p[j]     = ruby_decimal_digit_pairs[idx];
+                p[j + 1] = ruby_decimal_digit_pairs[idx + 1];
+            }
+            else {
+                /* num is 1..9 here (0 was handled above) */
+                p[--j] = (char)('0' + num);
+            }
+        }
+        else {
+            do {
+                BDIGIT_DBL idx = num % b2s->base;
+                num /= b2s->base;
+                p[--j] = ruby_digitmap[idx];
+            } while (num);
+        }
         len = sizeof(buf) - j;
         big2str_alloc(b2s, len + taillen);
         MEMCPY(b2s->ptr, buf + j, char, len);
@@ -4784,11 +4861,39 @@ big2str_2bdigits(struct big2str_struct *b2s, BDIGIT *xds, size_t xn, size_t tail
     else {
         p = b2s->ptr;
         j = b2s->hbase2_numdigits;
-        do {
-            BDIGIT_DBL idx = num % b2s->base;
-            num /= b2s->base;
-            p[--j] = ruby_digitmap[idx];
-        } while (j);
+        if (b2s->base == 10) {
+            /* Non-beginning chunks must emit EXACTLY hbase2_numdigits,
+             * zero-padded on the left.  Consume num in 2-digit groups,
+             * handle the odd trailing digit, then memset remaining
+             * positions with '0'. */
+            while (num >= 100) {
+                BDIGIT_DBL idx = (num % 100) * 2;
+                num /= 100;
+                j -= 2;
+                p[j]     = ruby_decimal_digit_pairs[idx];
+                p[j + 1] = ruby_decimal_digit_pairs[idx + 1];
+            }
+            if (num >= 10) {
+                BDIGIT_DBL idx = num * 2;
+                j -= 2;
+                p[j]     = ruby_decimal_digit_pairs[idx];
+                p[j + 1] = ruby_decimal_digit_pairs[idx + 1];
+            }
+            else if (num > 0) {
+                p[--j] = (char)('0' + num);
+            }
+            if (j > 0) {
+                memset(p, '0', j);
+                j = 0;
+            }
+        }
+        else {
+            do {
+                BDIGIT_DBL idx = num % b2s->base;
+                num /= b2s->base;
+                p[--j] = ruby_digitmap[idx];
+            } while (j);
+        }
         len = b2s->hbase2_numdigits;
     }
     b2s->ptr += len;
@@ -4892,7 +4997,7 @@ big2str_karatsuba(struct big2str_struct *b2s, BDIGIT *xds, size_t xn, size_t wn,
             /* bigdivrem_restoring will modify y.
              * So use temporary buffer.  */
             tds = xds + qn;
-            assert(qn + bn <= xn + wn);
+            RUBY_ASSERT(qn + bn <= xn + wn);
             bary_small_lshift(tds, bds, bn, shift);
             xds[xn] = bary_small_lshift(xds, xds, xn, shift);
         }
@@ -4910,7 +5015,7 @@ big2str_karatsuba(struct big2str_struct *b2s, BDIGIT *xds, size_t xn, size_t wn,
         }
 
         BARY_TRUNC(qds, qn);
-        assert(qn <= bn);
+        RUBY_ASSERT(qn <= bn);
         big2str_karatsuba(b2s, qds, qn, xn+wn - (rn+qn), lower_power_level, lower_numdigits+taillen);
         BARY_TRUNC(rds, rn);
         big2str_karatsuba(b2s, rds, rn, xn+wn - rn, lower_power_level, taillen);
@@ -4975,7 +5080,7 @@ big2str_generic(VALUE x, int base)
         invalid_radix(base);
 
     if (xn >= LONG_MAX/BITSPERDIG) {
-        rb_raise(rb_eRangeError, "bignum too big to convert into `string'");
+        rb_raise(rb_eRangeError, "bignum too big to convert into 'string'");
     }
 
     power_level = 0;
@@ -4985,7 +5090,7 @@ big2str_generic(VALUE x, int base)
         power_level++;
         power = power_cache_get_power(base, power_level, NULL);
     }
-    assert(power_level != MAX_BASE36_POWER_TABLE_ENTRIES);
+    RUBY_ASSERT(power_level != MAX_BASE36_POWER_TABLE_ENTRIES);
 
     if ((size_t)BIGNUM_LEN(power) <= xn) {
         /*
@@ -5100,7 +5205,7 @@ rb_big2str1(VALUE x, int base)
         invalid_radix(base);
 
     if (xn >= LONG_MAX/BITSPERDIG) {
-        rb_raise(rb_eRangeError, "bignum too big to convert into `string'");
+        rb_raise(rb_eRangeError, "bignum too big to convert into 'string'");
     }
 
     if (POW2_P(base)) {
@@ -5136,7 +5241,7 @@ big2ulong(VALUE x, const char *type)
     if (len == 0)
         return 0;
     if (BIGSIZE(x) > sizeof(long)) {
-        rb_raise(rb_eRangeError, "bignum too big to convert into `%s'", type);
+        rb_raise(rb_eRangeError, "bignum too big to convert into '%s'", type);
     }
     ds = BDIGITS(x);
 #if SIZEOF_LONG <= SIZEOF_BDIGIT
@@ -5179,7 +5284,7 @@ rb_big2long(VALUE x)
         if (num <= 1+(unsigned long)(-(LONG_MIN+1)))
             return -(long)(num-1)-1;
     }
-    rb_raise(rb_eRangeError, "bignum too big to convert into `long'");
+    rb_raise(rb_eRangeError, "bignum too big to convert into 'long'");
 }
 
 #if HAVE_LONG_LONG
@@ -5197,7 +5302,7 @@ big2ull(VALUE x, const char *type)
     if (len == 0)
         return 0;
     if (BIGSIZE(x) > SIZEOF_LONG_LONG)
-        rb_raise(rb_eRangeError, "bignum too big to convert into `%s'", type);
+        rb_raise(rb_eRangeError, "bignum too big to convert into '%s'", type);
 #if SIZEOF_LONG_LONG <= SIZEOF_BDIGIT
     num = (unsigned LONG_LONG)ds[0];
 #else
@@ -5238,7 +5343,7 @@ rb_big2ll(VALUE x)
         if (num <= 1+(unsigned LONG_LONG)(-(LLONG_MIN+1)))
             return -(LONG_LONG)(num-1)-1;
     }
-    rb_raise(rb_eRangeError, "bignum too big to convert into `long long'");
+    rb_raise(rb_eRangeError, "bignum too big to convert into 'long long'");
 }
 
 #endif  /* HAVE_LONG_LONG */
@@ -5501,10 +5606,10 @@ big_op(VALUE x, VALUE y, enum big_op_t op)
     n = FIX2INT(rel);
 
     switch (op) {
-        case big_op_gt: return RBOOL(n >  0);
-        case big_op_ge: return RBOOL(n >= 0);
-        case big_op_lt: return RBOOL(n <  0);
-        case big_op_le: return RBOOL(n <= 0);
+      case big_op_gt: return RBOOL(n >  0);
+      case big_op_ge: return RBOOL(n >= 0);
+      case big_op_lt: return RBOOL(n <  0);
+      case big_op_le: return RBOOL(n <= 0);
     }
     return Qundef;
 }
@@ -5660,7 +5765,7 @@ bigsub_int(VALUE x, long y0)
     zds = BDIGITS(z);
 
 #if SIZEOF_BDIGIT >= SIZEOF_LONG
-    assert(xn == zn);
+    RUBY_ASSERT(xn == zn);
     num = (BDIGIT_DBL_SIGNED)xds[0] - y;
     if (xn == 1 && num < 0) {
         BIGNUM_NEGATE(z);
@@ -5723,7 +5828,7 @@ bigsub_int(VALUE x, long y0)
     goto finish;
 
   finish:
-    assert(num == 0 || num == -1);
+    RUBY_ASSERT(num == 0 || num == -1);
     if (num < 0) {
         get2comp(z);
         BIGNUM_NEGATE(z);
@@ -5908,6 +6013,8 @@ bigsq(VALUE x)
     BDIGIT *xds, *zds;
 
     xn = BIGNUM_LEN(x);
+    if (MUL_OVERFLOW_LONG_P(2, xn))
+        rb_raise(rb_eArgError, "square overflow");
     zn = 2 * xn;
 
     z = bignew(zn, 1);
@@ -5936,6 +6043,8 @@ bigmul0(VALUE x, VALUE y)
 
     xn = BIGNUM_LEN(x);
     yn = BIGNUM_LEN(y);
+    if (ADD_OVERFLOW_LONG_P(xn, yn))
+        rb_raise(rb_eArgError, "multiplication overflow");
     zn = xn + yn;
 
     z = bignew(zn, BIGNUM_SIGN(x)==BIGNUM_SIGN(y));
@@ -6281,8 +6390,7 @@ rb_big_pow(VALUE x, VALUE y)
         y = bignorm(y);
         if (FIXNUM_P(y))
             goto again;
-        rb_warn("in a**b, b may be too big");
-        d = rb_big2dbl(y);
+        rb_raise(rb_eArgError, "exponent is too large");
     }
     else if (FIXNUM_P(y)) {
         yy = FIX2LONG(y);
@@ -6298,13 +6406,17 @@ rb_big_pow(VALUE x, VALUE y)
             VALUE z = 0;
             SIGNED_VALUE mask;
             const size_t xbits = rb_absint_numwords(x, 1, NULL);
-            const size_t BIGLEN_LIMIT = 32*1024*1024;
+#if SIZEOF_SIZE_T == 4
+            const size_t BIGLEN_LIMIT = 1ULL << 31; // 2 GB
+#else // SIZEOF_SIZE_T == 8
+            const size_t BIGLEN_LIMIT = 1ULL << 34; // 16 GB
+#endif
 
             if (xbits == (size_t)-1 ||
                 (xbits > BIGLEN_LIMIT) ||
+                MUL_OVERFLOW_LONG_P(yy, xbits) ||
                 (xbits * yy > BIGLEN_LIMIT)) {
-                rb_warn("in a**b, b may be too big");
-                d = (double)yy;
+                rb_raise(rb_eArgError, "exponent is too large");
             }
             else {
                 for (mask = FIXNUM_MAX + 1; mask; mask >>= 1) {
@@ -6333,7 +6445,7 @@ bigand_int(VALUE x, long xn, BDIGIT hibitsx, long y)
     BDIGIT hibitsy;
 
     if (y == 0) return INT2FIX(0);
-    if (xn == 0) return hibitsx ? LONG2NUM(y) : 0;
+    if (xn == 0) return hibitsx ? LONG2NUM(y) : INT2FIX(0);
     hibitsy = 0 <= y ? 0 : BDIGMAX;
     xds = BDIGITS(x);
 #if SIZEOF_BDIGIT >= SIZEOF_LONG
@@ -6745,6 +6857,73 @@ rb_big_aref(VALUE x, VALUE y)
 }
 
 VALUE
+rb_big_aref2(VALUE x, VALUE beg, VALUE len)
+{
+    BDIGIT *xds, *vds;
+    VALUE v;
+    size_t copy_begin, xn, shift;
+    ssize_t begin, length, end;
+    bool negative_add_one;
+
+    beg = rb_to_int(beg);
+    len = rb_to_int(len);
+    length = NUM2SSIZET(len);
+    begin = NUM2SSIZET(beg);
+    end = NUM2SSIZET(rb_int_plus(beg, len));
+    shift = begin < 0 ? -begin : 0;
+    xn = BIGNUM_LEN(x);
+    xds = BDIGITS(x);
+
+    if (length < 0) return rb_big_rshift(x, beg);
+    if (length == 0 || end <= 0) return INT2FIX(0);
+    if (begin < 0) begin = 0;
+
+    if ((size_t)(end - 1) / BITSPERDIG >= xn) {
+        /* end > xn * BITSPERDIG */
+        end = xn * BITSPERDIG;
+    }
+
+    if ((size_t)begin / BITSPERDIG < xn) {
+        /* begin < xn * BITSPERDIG */
+        size_t shift_bits, copy_end;
+        copy_begin = begin / BITSPERDIG;
+        shift_bits = begin % BITSPERDIG;
+        copy_end = (end - 1) / BITSPERDIG + 1;
+        v = bignew(copy_end - copy_begin, 1);
+        vds = BDIGITS(v);
+        MEMCPY(vds, xds + copy_begin, BDIGIT, copy_end - copy_begin);
+        negative_add_one = (vds[0] & ((1 << shift_bits) - 1)) == 0;
+        v = bignorm(v);
+        if (shift_bits) v = rb_int_rshift(v, SIZET2NUM(shift_bits));
+    }
+    else {
+        /* Out of range */
+        v = INT2FIX(0);
+        negative_add_one = false;
+        copy_begin = begin = end = 0;
+    }
+
+    if (BIGNUM_NEGATIVE_P(x)) {
+        size_t mask_size = length - shift;
+        VALUE mask = rb_int_minus(rb_int_lshift(INT2FIX(1), SIZET2NUM(mask_size)), INT2FIX(1));
+        v = rb_int_xor(v, mask);
+        for (size_t i = 0; negative_add_one && i < copy_begin; i++) {
+            if (xds[i]) negative_add_one = false;
+        }
+        if (negative_add_one) v = rb_int_plus(v, INT2FIX(1));
+        v = rb_int_and(v, mask);
+    }
+    else {
+        size_t mask_size = (size_t)end - begin;
+        VALUE mask = rb_int_minus(rb_int_lshift(INT2FIX(1), SIZET2NUM(mask_size)), INT2FIX(1));
+        v = rb_int_and(v, mask);
+    }
+    RB_GC_GUARD(x);
+    if (shift) v = rb_int_lshift(v, SSIZET2NUM(shift));
+    return v;
+}
+
+VALUE
 rb_big_hash(VALUE x)
 {
     st_index_t hash;
@@ -6878,63 +7057,11 @@ BDIGIT rb_bdigit_dbl_isqrt(BDIGIT_DBL);
 # define BDIGIT_DBL_TO_DOUBLE(n) (double)(n)
 #endif
 
-static BDIGIT *
-estimate_initial_sqrt(VALUE *xp, const size_t xn, const BDIGIT *nds, size_t len)
-{
-    enum {dbl_per_bdig = roomof(DBL_MANT_DIG,BITSPERDIG)};
-    const int zbits = nlz(nds[len-1]);
-    VALUE x = *xp = bignew_1(0, xn, 1); /* division may release the GVL */
-    BDIGIT *xds = BDIGITS(x);
-    BDIGIT_DBL d = bary2bdigitdbl(nds+len-dbl_per_bdig, dbl_per_bdig);
-    BDIGIT lowbits = 1;
-    int rshift = (int)((BITSPERDIG*2-zbits+(len&BITSPERDIG&1) - DBL_MANT_DIG + 1) & ~1);
-    double f;
-
-    if (rshift > 0) {
-        lowbits = (BDIGIT)d & ~(~(BDIGIT)1U << rshift);
-        d >>= rshift;
-    }
-    else if (rshift < 0) {
-        d <<= -rshift;
-        d |= nds[len-dbl_per_bdig-1] >> (BITSPERDIG+rshift);
-    }
-    f = sqrt(BDIGIT_DBL_TO_DOUBLE(d));
-    d = (BDIGIT_DBL)ceil(f);
-    if (BDIGIT_DBL_TO_DOUBLE(d) == f) {
-        if (lowbits || (lowbits = !bary_zero_p(nds, len-dbl_per_bdig)))
-            ++d;
-    }
-    else {
-        lowbits = 1;
-    }
-    rshift /= 2;
-    rshift += (2-(len&1))*BITSPERDIG/2;
-    if (rshift >= 0) {
-        if (nlz((BDIGIT)d) + rshift >= BITSPERDIG) {
-            /* (d << rshift) does cause overflow.
-             * example: Integer.sqrt(0xffff_ffff_ffff_ffff ** 2)
-             */
-            d = ~(BDIGIT_DBL)0;
-        }
-        else {
-            d <<= rshift;
-        }
-    }
-    BDIGITS_ZERO(xds, xn-2);
-    bdigitdbl2bary(&xds[xn-2], 2, d);
-
-    if (!lowbits) return NULL; /* special case, exact result */
-    return xds;
-}
-
 VALUE
 rb_big_isqrt(VALUE n)
 {
     BDIGIT *nds = BDIGITS(n);
     size_t len = BIGNUM_LEN(n);
-    size_t xn = (len+1) / 2;
-    VALUE x;
-    BDIGIT *xds;
 
     if (len <= 2) {
         BDIGIT sq = rb_bdigit_dbl_isqrt(bary2bdigitdbl(nds, len));
@@ -6944,25 +7071,19 @@ rb_big_isqrt(VALUE n)
         return ULONG2NUM(sq);
 #endif
     }
-    else if ((xds = estimate_initial_sqrt(&x, xn, nds, len)) != 0) {
-        size_t tn = xn + BIGDIVREM_EXTRA_WORDS;
-        VALUE t = bignew_1(0, tn, 1);
-        BDIGIT *tds = BDIGITS(t);
-        tn = BIGNUM_LEN(t);
-
-        /* t = n/x */
-        while (bary_divmod_branch(tds, tn, NULL, 0, nds, len, xds, xn),
-               bary_cmp(tds, tn, xds, xn) < 0) {
-            int carry;
-            BARY_TRUNC(tds, tn);
-            /* x = (x+t)/2 */
-            carry = bary_add(xds, xn, xds, xn, tds, tn);
-            bary_small_rshift(xds, xds, xn, 1, carry);
-            tn = BIGNUM_LEN(t);
+    else {
+        size_t shift = FIX2LONG(rb_big_bit_length(n)) / 4;
+        VALUE n2 = rb_int_rshift(n, SIZET2NUM(2 * shift));
+        VALUE x = FIXNUM_P(n2) ? LONG2FIX(rb_ulong_isqrt(FIX2ULONG(n2))) : rb_big_isqrt(n2);
+        /* x = (x+n/x)/2 */
+        x = rb_int_plus(rb_int_lshift(x, SIZET2NUM(shift - 1)), rb_int_idiv(rb_int_rshift(n, SIZET2NUM(shift + 1)), x));
+        VALUE xx = rb_int_mul(x, x);
+        while (rb_int_gt(xx, n)) {
+            xx = rb_int_minus(xx, rb_int_minus(rb_int_plus(x, x), INT2FIX(1)));
+            x = rb_int_minus(x, INT2FIX(1));
         }
+        return x;
     }
-    RBASIC_SET_CLASS_RAW(x, rb_cInteger);
-    return x;
 }
 
 #if USE_GMP
@@ -7001,14 +7122,14 @@ int_pow_tmp3(VALUE x, VALUE y, VALUE m, int nega_flg)
     if (FIXNUM_P(y)) {
        y = rb_int2big(FIX2LONG(y));
     }
-    assert(RB_BIGNUM_TYPE_P(m));
+    RUBY_ASSERT(RB_BIGNUM_TYPE_P(m));
     xn = BIGNUM_LEN(x);
     yn = BIGNUM_LEN(y);
     mn = BIGNUM_LEN(m);
     zn = mn;
     z = bignew(zn, 1);
     bary_powm_gmp(BDIGITS(z), zn, BDIGITS(x), xn, BDIGITS(y), yn, BDIGITS(m), mn);
-    if (nega_flg & BIGNUM_POSITIVE_P(z)) {
+    if (nega_flg && BIGNUM_POSITIVE_P(z) && !BIGZEROP(z)) {
         z = rb_big_minus(z, m);
     }
     RB_GC_GUARD(x);
@@ -7036,7 +7157,7 @@ int_pow_tmp3(VALUE x, VALUE y, VALUE m, int nega_flg)
         x = rb_int_modulo(x, m);
     }
 
-    if (nega_flg && rb_int_positive_p(tmp)) {
+    if (nega_flg && rb_int_positive_p(tmp) && !rb_int_zero_p(tmp)) {
         tmp = rb_int_minus(tmp, m);
     }
     return tmp;
@@ -7148,6 +7269,11 @@ rb_int_powm(int const argc, VALUE * const argv, VALUE const num)
             rb_raise(rb_eTypeError, "Integer#pow() 2nd argument not allowed unless all arguments are integers");
         }
 
+        if (rb_int_zero_p(a) && !rb_int_zero_p(b)) {
+            /* shortcut; 0**x => 0 except for x == 0 */
+            return INT2FIX(0);
+        }
+
         if (rb_int_negative_p(m)) {
             m = rb_int_uminus(m);
             nega_flg = 1;
diff --git a/bootstraptest/runner.rb b/bootstraptest/runner.rb
index c8ba824407..04de0c93b9 100755
--- a/bootstraptest/runner.rb
+++ b/bootstraptest/runner.rb
@@ -6,7 +6,6 @@
 # Never use optparse in this file.
 # Never use test/unit in this file.
 # Never use Ruby extensions in this file.
-# Maintain Ruby 1.8 compatibility for now
 
 $start_time = Time.now
 
@@ -17,6 +16,7 @@ rescue LoadError
   $:.unshift File.join(File.dirname(__FILE__), '../lib')
   retry
 end
+require_relative '../tool/lib/test/jobserver'
 
 if !Dir.respond_to?(:mktmpdir)
   # copied from lib/tmpdir.rb
@@ -77,6 +77,9 @@ bt = Struct.new(:ruby,
                 :width,
                 :indent,
                 :platform,
+                :timeout,
+                :timeout_scale,
+                :launchable_test_reports
                 )
 BT = Class.new(bt) do
   def indent=(n)
@@ -108,35 +111,7 @@ BT = Class.new(bt) do
 
   def wn=(wn)
     unless wn == 1
-      if /(?:\A|\s)--jobserver-(?:auth|fds)=(?:(\d+),(\d+)|fifo:((?:\\.|\S)+))/ =~ ENV.delete("MAKEFLAGS")
-        begin
-          if fifo = $3
-            fifo.gsub!(/\\(?=.)/, '')
-            r = File.open(fifo, IO::RDONLY|IO::NONBLOCK|IO::BINARY)
-            w = File.open(fifo, IO::WRONLY|IO::NONBLOCK|IO::BINARY)
-          else
-            r = IO.for_fd($1.to_i(10), "rb", autoclose: false)
-            w = IO.for_fd($2.to_i(10), "wb", autoclose: false)
-          end
-        rescue
-          r.close if r
-        else
-          r.close_on_exec = true
-          w.close_on_exec = true
-          tokens = r.read_nonblock(wn > 0 ? wn : 1024, exception: false)
-          r.close
-          if String === tokens
-            tokens.freeze
-            auth = w
-            w = nil
-            at_exit {auth << tokens; auth.close}
-            wn = tokens.size + 1
-          else
-            w.close
-            wn = 1
-          end
-        end
-      end
+      wn = Test::JobServer.max_jobs(wn > 0 ? wn : 1024, ENV.delete("MAKEFLAGS")) || wn
       if wn <= 0
         require 'etc'
         wn = [Etc.nprocessors / 2, 1].max
@@ -144,6 +119,10 @@ BT = Class.new(bt) do
     end
     super wn
   end
+
+  def apply_timeout_scale(timeout)
+    timeout&.*(timeout_scale)
+  end
 end.new
 
 BT_STATE = Struct.new(:count, :error).new
@@ -156,6 +135,12 @@ def main
   BT.color = nil
   BT.tty = nil
   BT.quiet = false
+  BT.timeout = 180
+  BT.timeout_scale = 1
+  if (ts = (ENV["RUBY_TEST_TIMEOUT_SCALE"] || ENV["RUBY_TEST_SUBPROCESS_TIMEOUT_SCALE"]).to_i) > 1
+    BT.timeout_scale *= ts
+  end
+
   # BT.wn = 1
   dir = nil
   quiet = false
@@ -186,14 +171,18 @@ def main
       warn "unknown --tty argument: #$3" if $3
       BT.tty = !$1 || !$2
       true
-    when /\A(-q|--q(uiet))\z/
+    when /\A(-q|--q(uiet)?)\z/
       quiet = true
       BT.quiet = true
       true
     when /\A-j(\d+)?/
       BT.wn = $1.to_i
       true
-    when /\A(-v|--v(erbose))\z/
+    when /\A--timeout=(\d+(?:_\d+)*(?:\.\d+(?:_\d+)*)?)(?::(\d+(?:_\d+)*(?:\.\d+(?:_\d+)*)?))?/
+      BT.timeout = $1.to_f
+      BT.timeout_scale = $2.to_f if defined?($2)
+      true
+    when /\A(-v|--v(erbose)?)\z/
       BT.verbose = true
       BT.quiet = false
       true
@@ -205,6 +194,7 @@ Usage: #{File.basename($0, '.*')} --ruby=PATH [--sets=NAME,NAME,...]
                                     default: /tmp/bootstraptestXXXXX.tmpwd
         --color[=WHEN]              Colorize the output.  WHEN defaults to 'always'
                                     or can be 'never' or 'auto'.
+        --timeout=TIMEOUT           Default timeout in seconds.
     -s, --stress                    stress test.
     -v, --verbose                   Output test name before exec.
     -q, --quiet                     Don\'t print header message.
@@ -213,6 +203,31 @@ End
       exit true
     when /\A-j/
       true
+    when /--launchable-test-reports=(.*)/
+      if File.exist?($1)
+        # To protect files from overwritten, do nothing when the file exists.
+        return true
+      end
+
+      begin
+        require_relative '../tool/lib/launchable'
+      rescue LoadError
+        # The following error sometimes happens, so we're going to skip writing Launchable report files in this case.
+        #
+        # ```
+        # /tmp/tmp.bISss9CtXZ/.ext/common/json/ext.rb:15:in 'Kernel#require':
+        #   /tmp/tmp.bISss9CtXZ/.ext/x86_64-linux/json/ext/parser.so:
+        #     undefined symbol: ruby_abi_version - ruby_abi_version (LoadError)
+        # ```
+        #
+        return true
+      end
+      BT.launchable_test_reports = writer = Launchable::JsonStreamWriter.new($1)
+      writer.write_array('testCases')
+      at_exit {
+        writer.close
+      }
+      true
     else
       false
     end
@@ -222,7 +237,7 @@ End
   end
   tests ||= ARGV
   tests = Dir.glob("#{File.dirname($0)}/test_*.rb").sort if tests.empty?
-  pathes = tests.map {|path| File.expand_path(path) }
+  paths = tests.map {|path| File.expand_path(path) }
 
   BT.progress = %w[- \\ | /]
   BT.progress_bs = "\b" * BT.progress[0].size
@@ -256,7 +271,7 @@ End
     if defined?(RUBY_DESCRIPTION)
       puts "Driver is #{RUBY_DESCRIPTION}"
     elsif defined?(RUBY_PATCHLEVEL)
-      puts "Driver is ruby #{RUBY_VERSION} (#{RUBY_RELEASE_DATE}#{RUBY_PLATFORM}) [#{RUBY_PLATFORM}]"
+      puts "Driver is ruby #{RUBY_VERSION} (#{RUBY_RELEASE_DATE}#{RUBY_PATCHLEVEL}) [#{RUBY_PLATFORM}]"
     else
       puts "Driver is ruby #{RUBY_VERSION} (#{RUBY_RELEASE_DATE}) [#{RUBY_PLATFORM}]"
     end
@@ -266,7 +281,7 @@ End
   end
 
   in_temporary_working_directory(dir) do
-    exec_test pathes
+    exec_test paths
   end
 end
 
@@ -278,8 +293,8 @@ def erase(e = true)
   end
 end
 
-def load_test pathes
-  pathes.each do |path|
+def load_test paths
+  paths.each do |path|
     load File.expand_path(path)
   end
 end
@@ -312,6 +327,7 @@ def concurrent_exec_test
   begin
     while BT.wn != term_wn
       if r = rq.pop
+        BT_STATE.count += 1
         case
         when BT.quiet
         when BT.tty
@@ -329,13 +345,66 @@ def concurrent_exec_test
   end
 end
 
-def exec_test(pathes)
+##
+# Module for writing a test file for uploading test results into Launchable.
+# In bootstraptest, we aggregate the test results based on file level.
+module Launchable
+  @@last_test_name = nil
+  @@failure_log = ''
+  @@duration = 0
+
+  def show_progress(message = '')
+    faildesc, t = super
+
+    if writer = BT.launchable_test_reports
+      if faildesc
+        @@failure_log += faildesc
+      end
+      repo_path = File.expand_path("#{__dir__}/../")
+      relative_path = File.join(__dir__, self.path).delete_prefix("#{repo_path}/")
+      if @@last_test_name != nil && @@last_test_name != relative_path
+        # The test path is a URL-encoded representation.
+        # https://github.com/launchableinc/cli/blob/v1.81.0/launchable/testpath.py#L18
+        test_path = "#{encode_test_path_component("file")}=#{encode_test_path_component(@@last_test_name)}"
+        if @@failure_log.size > 0
+          status = 'TEST_FAILED'
+        else
+          status = 'TEST_PASSED'
+        end
+        writer.write_object(
+          {
+            testPath: test_path,
+            status: status,
+            duration: t,
+            createdAt: Time.now.to_s,
+            stderr: @@failure_log,
+            stdout: nil,
+            data: {
+              lineNumber: self.lineno
+            }
+          }
+        )
+        @@duration = 0
+        @@failure_log = ''
+      end
+      @@last_test_name = relative_path
+      @@duration += t
+    end
+  end
+
+  private
+  def encode_test_path_component component
+    component.to_s.gsub('%', '%25').gsub('=', '%3D').gsub('#', '%23').gsub('&', '%26')
+  end
+end
+
+def exec_test(paths)
   # setup
-  load_test pathes
+  load_test paths
   BT_STATE.count = 0
   BT_STATE.error = 0
   BT.columns = 0
-  BT.width = pathes.map {|path| File.basename(path).size}.max + 2
+  BT.width = paths.map {|path| File.basename(path).size}.max + 2
 
   # execute tests
   if BT.wn > 1
@@ -405,6 +474,7 @@ def target_platform
 end
 
 class Assertion < Struct.new(:src, :path, :lineno, :proc)
+  prepend Launchable
   @count = 0
   @all = Hash.new{|h, k| h[k] = []}
   @errbuf = []
@@ -428,7 +498,7 @@ class Assertion < Struct.new(:src, :path, :lineno, :proc)
   def initialize(*args)
     super
     self.class.add self
-    @category = self.path.match(/test_(.+)\.rb/)[1]
+    @category = self.path[/\Atest_(.+)\.rb\z/, 1]
   end
 
   def call
@@ -479,9 +549,9 @@ class Assertion < Struct.new(:src, :path, :lineno, :proc)
       $stderr.print "#{BT.progress_bs}#{BT.progress[BT_STATE.count % BT.progress.size]}"
     end
 
-    t = Time.now if BT.verbose
+    t = Time.now if BT.verbose || BT.launchable_test_reports
     faildesc, errout = with_stderr {yield}
-    t = Time.now - t if BT.verbose
+    t = Time.now - t if BT.verbose || BT.launchable_test_reports
 
     if !faildesc
       # success
@@ -508,6 +578,8 @@ class Assertion < Struct.new(:src, :path, :lineno, :proc)
         $stderr.printf("%-*s%s", BT.width, path, BT.progress[BT_STATE.count % BT.progress.size])
       end
     end
+
+    [faildesc, t]
   rescue Interrupt
     $stderr.puts "\##{@id} #{path}:#{lineno}"
     raise
@@ -526,14 +598,22 @@ class Assertion < Struct.new(:src, :path, :lineno, :proc)
     end
   end
 
-  def get_result_string(opt = '', **argh)
+  class Timeout < StandardError; end
+
+  def get_result_string(opt = '', timeout: BT.timeout, **argh)
     if BT.ruby
+      timeout = BT.apply_timeout_scale(timeout)
       filename = make_srcfile(**argh)
       begin
         kw = self.err ? {err: self.err} : {}
         out = IO.popen("#{BT.ruby} -W0 #{opt} #{filename}", **kw)
         pid = out.pid
-        out.read.tap{ Process.waitpid(pid); out.close }
+        th = Thread.new {out.read.tap {Process.waitpid(pid); out.close}}
+        if th.join(timeout)
+          th.value
+        else
+          Timeout.new("timed out after #{timeout} seconds")
+        end
       ensure
         raise Interrupt if $? and $?.signaled? && $?.termsig == Signal.list["INT"]
 
@@ -551,9 +631,14 @@ class Assertion < Struct.new(:src, :path, :lineno, :proc)
   def make_srcfile(frozen_string_literal: nil)
     filename = "bootstraptest.#{self.path}_#{self.lineno}_#{self.id}.rb"
     File.open(filename, 'w') {|f|
-      f.puts "#frozen_string_literal:true" if frozen_string_literal
-      f.puts "GC.stress = true" if $stress
-      f.puts "print(begin; #{self.src}; end)"
+      f.puts "#frozen_string_literal:#{frozen_string_literal}" unless frozen_string_literal.nil?
+      if $stress
+        f.puts "GC.stress = true" if $stress
+      else
+        f.puts ""
+      end
+      f.puts "class BT_Skip < Exception; end; def skip(msg) = raise(BT_Skip, msg.to_s)"
+      f.puts "print(begin; #{self.src}; rescue BT_Skip; $!.message; end)"
     }
     filename
   end
@@ -567,9 +652,9 @@ def add_assertion src, pr
   Assertion.new(src, path, lineno, pr)
 end
 
-def assert_equal(expected, testsrc, message = '', opt = '', **argh)
+def assert_equal(expected, testsrc, message = '', opt = '', **kwargs)
   add_assertion testsrc, -> as do
-    as.assert_check(message, opt, **argh) {|result|
+    as.assert_check(message, opt, **kwargs) {|result|
       if expected == result
         nil
       else
@@ -580,9 +665,9 @@ def assert_equal(expected, testsrc, message = '', opt = '', **argh)
   end
 end
 
-def assert_match(expected_pattern, testsrc, message = '')
+def assert_match(expected_pattern, testsrc, message = '', **argh)
   add_assertion testsrc, -> as do
-    as.assert_check(message) {|result|
+    as.assert_check(message, **argh) {|result|
       if expected_pattern =~ result
         nil
       else
@@ -614,8 +699,9 @@ def assert_valid_syntax(testsrc, message = '')
   end
 end
 
-def assert_normal_exit(testsrc, *rest, timeout: nil, **opt)
+def assert_normal_exit(testsrc, *rest, timeout: BT.timeout, **opt)
   add_assertion testsrc, -> as do
+    timeout = BT.apply_timeout_scale(timeout)
     message, ignore_signals = rest
     message ||= ''
     as.show_progress(message) {
@@ -624,23 +710,19 @@ def assert_normal_exit(testsrc, *rest, timeout: nil, **opt)
       timeout_signaled = false
       logfile = "assert_normal_exit.#{as.path}.#{as.lineno}.log"
 
-      begin
-        err = open(logfile, "w")
-        io = IO.popen("#{BT.ruby} -W0 #{filename}", err: err)
-        pid = io.pid
-        th = Thread.new {
-          io.read
-          io.close
-          $?
-        }
-        if !th.join(timeout)
-          Process.kill :KILL, pid
-          timeout_signaled = true
-        end
-        status = th.value
-      ensure
-        err.close
+      io = IO.popen("#{BT.ruby} -W0 #{filename}", err: logfile)
+      pid = io.pid
+      th = Thread.new {
+        io.read
+        io.close
+        $?
+      }
+      if !th.join(timeout)
+        Process.kill :KILL, pid
+        timeout_signaled = true
       end
+      status = th.value
+
       if status && status.signaled?
         signo = status.termsig
         signame = Signal.list.invert[signo]
@@ -669,9 +751,7 @@ end
 
 def assert_finish(timeout_seconds, testsrc, message = '')
   add_assertion testsrc, -> as do
-    if defined?(RubyVM::RJIT) && RubyVM::RJIT.enabled? # for --jit-wait
-      timeout_seconds *= 3
-    end
+    timeout_seconds = BT.apply_timeout_scale(timeout_seconds)
 
     as.show_progress(message) {
       faildesc = nil
@@ -727,6 +807,8 @@ end
 
 def pretty(src, desc, result)
   src = src.sub(/\A\s*\n/, '')
+  lines = src.lines
+  src = lines[0..20].join + "(...snip)\n" if lines.size > 20
   (/\n/ =~ src ? "\n#{adjust_indent(src)}" : src) + "  #=> #{desc}"
 end
 
@@ -784,4 +866,12 @@ def check_coredump
   end
 end
 
+def yjit_enabled?
+  ENV.key?('RUBY_YJIT_ENABLE') || ENV.fetch('RUN_OPTS', '').include?('yjit') || BT.ruby.include?('yjit')
+end
+
+def zjit_enabled?
+  ENV.key?('RUBY_ZJIT_ENABLE') || ENV.fetch('RUN_OPTS', '').include?('zjit') || BT.ruby.include?('zjit')
+end
+
 exit main
diff --git a/bootstraptest/test_autoload.rb b/bootstraptest/test_autoload.rb
index 9e0850bc52..de66f1f3ee 100644
--- a/bootstraptest/test_autoload.rb
+++ b/bootstraptest/test_autoload.rb
@@ -11,7 +11,7 @@ assert_equal 'ok', %q{
 }, '[ruby-dev:43816]'
 
 assert_equal 'ok', %q{
-  open('zzz2.rb', 'w') {|f| f.puts '' }
+  File.write('zzz2.rb', '')
   instance_eval do
     autoload :ZZZ, './zzz2.rb'
     begin
@@ -23,7 +23,7 @@ assert_equal 'ok', %q{
 }, '[ruby-dev:43816]'
 
 assert_equal 'ok', %q{
-  open('zzz3.rb', 'w') {|f| f.puts 'class ZZZ; def self.ok;:ok;end;end'}
+  File.write('zzz3.rb', "class ZZZ; def self.ok;:ok;end;end\n")
   instance_eval do
     autoload :ZZZ, './zzz3.rb'
     ZZZ.ok
@@ -31,20 +31,20 @@ assert_equal 'ok', %q{
 }, '[ruby-dev:43816]'
 
 assert_equal 'ok', %q{
-  open("zzz4.rb", "w") {|f| f.puts "class ZZZ; def self.ok;:ok;end;end"}
+  File.write("zzz4.rb", "class ZZZ; def self.ok;:ok;end;end\n")
   autoload :ZZZ, "./zzz4.rb"
   ZZZ.ok
 }
 
 assert_equal 'ok', %q{
-  open("zzz5.rb", "w") {|f| f.puts "class ZZZ; def self.ok;:ok;end;end"}
+  File.write("zzz5.rb", "class ZZZ; def self.ok;:ok;end;end\n")
   autoload :ZZZ, "./zzz5.rb"
   require "./zzz5.rb"
   ZZZ.ok
 }
 
 assert_equal 'okok', %q{
-  open("zzz6.rb", "w") {|f| f.puts "class ZZZ; def self.ok;:ok;end;end"}
+  File.write("zzz6.rb", "class ZZZ; def self.ok;:ok;end;end\n")
   autoload :ZZZ, "./zzz6.rb"
   t1 = Thread.new {ZZZ.ok}
   t2 = Thread.new {ZZZ.ok}
@@ -60,7 +60,7 @@ assert_finish 5, %q{
 }, '[ruby-core:21696]'
 
 assert_equal 'A::C', %q{
-  open("zzz7.rb", "w") {}
+  File.write("zzz7.rb", "")
   class A
     autoload :C, "./zzz7"
     class C
diff --git a/bootstraptest/test_eval.rb b/bootstraptest/test_eval.rb
index a9f389c673..20bd9615f4 100644
--- a/bootstraptest/test_eval.rb
+++ b/bootstraptest/test_eval.rb
@@ -217,7 +217,7 @@ assert_equal %q{[10, main]}, %q{
 }
 
 %w[break next redo].each do |keyword|
-  assert_match %r"Can't escape from eval with #{keyword}\b", %{
+  assert_match %r"Invalid #{keyword}\b", %{
     $stderr = STDOUT
     begin
       eval "0 rescue #{keyword}"
@@ -227,6 +227,16 @@ assert_equal %q{[10, main]}, %q{
   }, '[ruby-dev:31372]'
 end
 
+assert_normal_exit %{
+  $stderr = STDOUT
+  5000.times do
+    begin
+      eval "0 rescue break"
+    rescue SyntaxError
+    end
+  end
+}
+
 assert_normal_exit %q{
   $stderr = STDOUT
   class Foo
@@ -354,3 +364,34 @@ assert_normal_exit %q{
   end
 }, 'check escaping the internal value th->base_block'
 
+assert_equal "false", <<~RUBY, "literal strings are mutable", "--disable-frozen-string-literal"
+  eval("'test'").frozen?
+RUBY
+
+assert_equal "false", <<~RUBY, "literal strings are mutable", "--disable-frozen-string-literal", frozen_string_literal: true
+  eval("'test'").frozen?
+RUBY
+
+assert_equal "true", <<~RUBY, "literal strings are frozen", "--enable-frozen-string-literal"
+  eval("'test'").frozen?
+RUBY
+
+assert_equal "true", <<~RUBY, "literal strings are frozen", "--enable-frozen-string-literal", frozen_string_literal: false
+  eval("'test'").frozen?
+RUBY
+
+assert_equal "false", <<~RUBY, "__FILE__ is mutable", "--disable-frozen-string-literal"
+  eval("__FILE__").frozen?
+RUBY
+
+assert_equal "false", <<~RUBY, "__FILE__ is mutable", "--disable-frozen-string-literal", frozen_string_literal: true
+  eval("__FILE__").frozen?
+RUBY
+
+assert_equal "true", <<~RUBY, "__FILE__ is frozen", "--enable-frozen-string-literal"
+  eval("__FILE__").frozen?
+RUBY
+
+assert_equal "true", <<~RUBY, "__FILE__ is frozen", "--enable-frozen-string-literal", frozen_string_literal: false
+  eval("__FILE__").frozen?
+RUBY
diff --git a/bootstraptest/test_exception.rb b/bootstraptest/test_exception.rb
index 0fb6f552b8..decfdc08a3 100644
--- a/bootstraptest/test_exception.rb
+++ b/bootstraptest/test_exception.rb
@@ -370,7 +370,7 @@ assert_equal %q{}, %q{
 }
 
 ##
-assert_match /undefined method `foo\'/, %q{#`
+assert_match /undefined method 'foo\'/, %q{#`
   STDERR.reopen(STDOUT)
   class C
     def inspect
diff --git a/bootstraptest/test_fiber.rb b/bootstraptest/test_fiber.rb
index 2614dd13bf..ae809a5936 100644
--- a/bootstraptest/test_fiber.rb
+++ b/bootstraptest/test_fiber.rb
@@ -37,3 +37,8 @@ assert_normal_exit %q{
 assert_normal_exit %q{
   Fiber.new(&Object.method(:class_eval)).resume("foo")
 }, '[ruby-dev:34128]'
+
+# [Bug #21400]
+assert_normal_exit %q{
+  Thread.new { Fiber.current.kill }.join
+}
diff --git a/bootstraptest/test_finalizer.rb b/bootstraptest/test_finalizer.rb
index 22a16b1220..ccfa0b55d6 100644
--- a/bootstraptest/test_finalizer.rb
+++ b/bootstraptest/test_finalizer.rb
@@ -6,3 +6,11 @@ ObjectSpace.define_finalizer(b1,proc{b1.inspect})
 ObjectSpace.define_finalizer(a2,proc{a1.inspect})
 ObjectSpace.define_finalizer(a1,proc{})
 }, '[ruby-dev:35778]'
+
+assert_equal 'true', %q{
+  obj = Object.new
+  id = obj.object_id
+
+  ObjectSpace.define_finalizer(obj, proc { |i| print(id == i) })
+  nil
+}
diff --git a/bootstraptest/test_flow.rb b/bootstraptest/test_flow.rb
index 35f19db588..7a95def1e6 100644
--- a/bootstraptest/test_flow.rb
+++ b/bootstraptest/test_flow.rb
@@ -363,7 +363,7 @@ assert_equal %q{[1, 2, 3, 5, 2, 3, 5, 7, 8]}, %q{$a = []; begin;  ; $a << 1
 ; $a << 8
 ; rescue Exception; $a << 99; end; $a}
 assert_equal %q{[1, 2, 6, 3, 5, 7, 8]}, %q{$a = []; begin;  ; $a << 1
-  o = "test"; $a << 2
+  o = "test".dup; $a << 2
   def o.test(a); $a << 3
     return a; $a << 4
   ensure; $a << 5
@@ -376,7 +376,7 @@ assert_equal %q{[1, 4, 7, 5, 8, 9]}, %q{$a = []; begin; ; $a << 1
     ; $a << 3
   end; $a << 4
   def m2; $a << 5
-    m1(:a, :b, (return 1; :c)); $a << 6
+    m1(:a, :b, (return 1 if true; :c)); $a << 6
   end; $a << 7
   m2; $a << 8
 ; $a << 9
@@ -399,7 +399,7 @@ assert_equal %q{[1, 3, 11, 4, 5, 6, 7, 12, 13]}, %q{$a = []; begin; ; $a << 1
     m2(begin; $a << 5
          2; $a << 6
        ensure; $a << 7
-         return 3; $a << 8
+         return 3 if true; $a << 8
        end); $a << 9
     4; $a << 10
   end; $a << 11
diff --git a/bootstraptest/test_fork.rb b/bootstraptest/test_fork.rb
index 83923dad97..860ef285d0 100644
--- a/bootstraptest/test_fork.rb
+++ b/bootstraptest/test_fork.rb
@@ -75,3 +75,30 @@ assert_equal '[1, 2]', %q{
   end
 }, '[ruby-dev:44005] [Ruby 1.9 - Bug #4950]'
 
+assert_equal 'ok', %q{
+  def now = Process.clock_gettime(Process::CLOCK_MONOTONIC)
+
+  Thread.new do
+    loop { sleep 0.0001 }
+  end
+
+  10.times do
+    pid = fork{ exit!(0) }
+    deadline = now + 10
+    while true
+      _, status = Process.waitpid2(pid, Process::WNOHANG)
+      break if status
+      if now > deadline
+        Process.kill(:KILL, pid)
+        raise "failed"
+      end
+      sleep 0.001
+    end
+    unless status.success?
+      raise "child exited with status #{status}"
+    end
+  rescue NotImplementedError
+  end
+  :ok
+}, '[Bug #20670]'
+
diff --git a/bootstraptest/test_gc.rb b/bootstraptest/test_gc.rb
index 9f17e14814..eb68c9845e 100644
--- a/bootstraptest/test_gc.rb
+++ b/bootstraptest/test_gc.rb
@@ -14,7 +14,7 @@ ms = "a".."k"
     o.send(meth)
   end
 end
-}, '[ruby-dev:39453]' unless ENV.fetch('RUN_OPTS', '').include?('rjit') # speed up RJIT CI
+}, '[ruby-dev:39453]'
 
 assert_normal_exit %q{
 a = []
diff --git a/bootstraptest/test_insns.rb b/bootstraptest/test_insns.rb
index d2e799f855..1f70c8075c 100644
--- a/bootstraptest/test_insns.rb
+++ b/bootstraptest/test_insns.rb
@@ -86,13 +86,13 @@ tests = [
   [ 'putobject',            %q{ /(?<x>x)/ =~ "x"; x == "x" }, ],
 
   [ 'putspecialobject',         %q{ {//=>true}[//] }, ],
-  [ 'putstring',                %q{ "true" }, ],
+  [ 'dupstring',                %q{ "true" }, ],
   [ 'tostring / concatstrings', %q{ "#{true}" }, ],
   [ 'toregexp',                 %q{ /#{true}/ =~ "true" && $~ }, ],
   [ 'intern',                   %q{ :"#{true}" }, ],
 
   [ 'newarray',    %q{ ["true"][0] }, ],
-  [ 'newarraykwsplat', %q{ [**{x:'true'}][0][:x] }, ],
+  [ 'pushtoarraykwsplat', %q{ [**{x:'true'}][0][:x] }, ],
   [ 'duparray',    %q{ [ true ][0] }, ],
   [ 'expandarray', %q{ y = [ true, false, nil ]; x, = y; x }, ],
   [ 'expandarray', %q{ y = [ true, false, nil ]; x, *z = y; x }, ],
@@ -214,8 +214,21 @@ tests = [
     'true'.freeze
   },
 
+  [ 'opt_duparray_send', %q{ x = :a; [:a, :b].include?(x) }, ],
+  [ 'opt_duparray_send', <<-'},', ], # {
+    class Array
+      def include?(i)
+        i == 1
+      end
+    end
+    x = 1
+    [:a, :b].include?(x)
+  },
+
   [ 'opt_newarray_send', %q{ ![ ].hash.nil? }, ],
 
+  [ 'opt_newarray_send', %q{ v=2; [1, Object.new, 2].include?(v) }, ],
+
   [ 'opt_newarray_send', %q{ [ ].max.nil? }, ],
   [ 'opt_newarray_send', %q{ [1, x = 2, 3].max == 3 }, ],
   [ 'opt_newarray_send', <<-'},', ], # {
@@ -236,6 +249,48 @@ tests = [
     end
     [3, x = 2, 1].min
   },
+  [ 'opt_newarray_send', %q{ v = 1.23; [v, v*2].pack("E*").unpack("E*") == [v, v*2] }, ],
+  [ 'opt_newarray_send', %q{ v = 4.56; b = +"x"; [v, v*2].pack("E*", buffer: b); b[1..].unpack("E*") == [v, v*2] }, ],
+  [ 'opt_newarray_send', <<-'},', ], # {
+    v = 7.89;
+    b = +"x";
+    class Array
+      alias _pack pack
+      def pack(s, buffer: nil, prefix: "y")
+        buffer ||= +"b"
+        buffer << prefix
+        _pack(s, buffer: buffer)
+      end
+    end
+    tests = []
+
+    ret = [v].pack("E*", prefix: "z")
+    tests << (ret[0..1] == "bz")
+    tests << (ret[2..].unpack("E*") == [v])
+
+    ret = [v].pack("E*")
+    tests << (ret[0..1] == "by")
+    tests << (ret[2..].unpack("E*") == [v])
+
+    [v, v*2, v*3].pack("E*", buffer: b)
+    tests << (b[0..1] == "xy")
+    tests << (b[2..].unpack("E*") == [v, v*2, v*3])
+
+    class Array
+      def pack(_fmt, buffer:) = buffer
+    end
+
+    b = nil
+    tests << [v].pack("E*", buffer: b).nil?
+
+    class Array
+      def pack(_fmt, **kw) = kw.empty?
+    end
+
+    tests << [v].pack("E*") == true
+
+    tests.all? or puts tests
+  },
 
   [ 'throw',        %q{ false.tap { break true } }, ],
   [ 'branchif',     %q{ x = nil;  x ||= true }, ],
@@ -354,7 +409,7 @@ tests = [
   [ 'opt_ge', %q{ +0.0.next_float >= 0.0 }, ],
   [ 'opt_ge', %q{              ?z >= ?a }, ],
 
-  [ 'opt_ltlt', %q{  '' << 'true' }, ],
+  [ 'opt_ltlt', %q{  +'' << 'true' }, ],
   [ 'opt_ltlt', %q{ ([] << 'true').join }, ],
   [ 'opt_ltlt', %q{ (1 << 31) == 2147483648 }, ],
 
@@ -363,7 +418,7 @@ tests = [
   [ 'opt_aref', %q{ 'true'[0] == ?t }, ],
   [ 'opt_aset', %q{ [][0] = true }, ],
   [ 'opt_aset', %q{ {}[0] = true }, ],
-  [ 'opt_aset', %q{ x = 'frue'; x[0] = 't'; x }, ],
+  [ 'opt_aset', %q{ x = +'frue'; x[0] = 't'; x }, ],
   [ 'opt_aset', <<-'},', ], # {
     # opt_aref / opt_aset mixup situation
     class X; def x; {}; end; end
@@ -371,11 +426,6 @@ tests = [
     x&.x[true] ||= true         # here
   },
 
-  [ 'opt_aref_with', %q{ { 'true' => true }['true'] }, ],
-  [ 'opt_aref_with', %q{ Struct.new(:nil).new['nil'].nil? }, ],
-  [ 'opt_aset_with', %q{ {}['true'] = true }, ],
-  [ 'opt_aset_with', %q{ Struct.new(:true).new['true'] = true }, ],
-
   [ 'opt_length',  %q{   'true'       .length == 4 }, ],
   [ 'opt_length',  %q{   :true        .length == 4 }, ],
   [ 'opt_length',  %q{ [ 'true' ]     .length == 1 }, ],
diff --git a/bootstraptest/test_io.rb b/bootstraptest/test_io.rb
index 666e5a011b..4081769a8c 100644
--- a/bootstraptest/test_io.rb
+++ b/bootstraptest/test_io.rb