[ruby/rubygems] Take one timestamp per multi-source repo buildHEAD master

Stamping each solo_gem with its own Time.now.utc lets the two dates drift apart and matches neither the surrounding before block. Snapshot the time once so the cooldown window stays stable as thresholds tighten. https://github.com/ruby/rubygems/commit/69c6d876d4 Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
author: Hiroshi SHIBATA <hsbt@ruby-lang.org> 2026-06-08 17:53:34 +0900
committer: git <svn-admin@ruby-lang.org> 2026-06-08 09:39:45 +0000
commit: 7ed00ca7a9d3b28330afd4451b8f1613ccd01d83 (patch)
tree: 00e3212c0c1cd8043bd465a87f0819de119b9397 /spec/rubyspec/core/enumerable/map_spec.rb
parent: fadf8f0ea07c94b16d99e369481c3f62614e9ebe (diff)
0 files changed, 0 insertions, 0 deletions
diff --git a/.appveyor.yml b/.appveyor.yml
deleted file mode 100644
index 6803edff9b..0000000000
--- a/.appveyor.yml
+++ /dev/null
@@ -1,131 +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: "24-%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
-      ssl: OpenSSL-v111
-      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
-    - 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:
-    - 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=-v --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=-v --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 MSPECOPT=-fs # not using `-j` because sometimes `mspec -j` silently dies on Windows
-notifications:
-  - provider: Webhook
-    method: POST
-    url:
-      secure: CcFlJNDJ/a6to7u3Z4Fnz6dScEPNx7hTha2GkSRlV+1U6dqmxY/7uBcLXYb9gR3jfQk6w+2o/HrjNAyXMNGU/JOka3s2WRI4VKitzM+lQ08owvJIh0R7LxrGH0J2e81U # ruby-lang slack: ruby/simpler-alerts-bot
-    body: >-
-      {{^isPullRequest}}
-        {
-          "ci": "AppVeyor CI",
-          "env": "Visual Studio 2013",
-          "url": "{{buildUrl}}",
-          "commit": "{{commitId}}",
-          "branch": "{{branch}}"
-        }
-      {{/isPullRequest}}
-    on_build_success: false
-    on_build_failure: true
-    on_build_status_changed: false
diff --git a/.cirrus.yml b/.cirrus.yml
deleted file mode 100644
index 20c14f375c..0000000000
--- a/.cirrus.yml
+++ /dev/null
@@ -1,134 +0,0 @@
-# This CI is used to test Arm cases. We can set the maximum 16 tasks.
-# The entire testing design is inspired from .github/workflows/compilers.yml.
-
-# By default, Cirrus mounts an empty volume to `/tmp`
-# which triggers all sorts of warnings like "system temporary path is world-writable: /tmp".
-# Lets workaround it by specifying a custom volume mount point.
-env:
-  CIRRUS_VOLUME: /cirrus-ci-volume
-  LANG: C.UTF-8
-
-task:
-  name: Arm64 Graviton2 / $CC
-  skip: "changesIncludeOnly('doc/**', '**.{md,rdoc,ronn,[1-8]}', '.document')"
-  arm_container:
-    # We use the arm64 images at https://github.com/ruby/ruby-ci-image/pkgs/container/ruby-ci-image .
-    image: ghcr.io/ruby/ruby-ci-image:$CC
-    # Define the used cpu core in each matrix task. We can use total 16 cpu
-    # cores in entire matrix. [cpu] = [total cpu: 16] / [number of tasks]
-    cpu: 8
-    # We can request maximum 4 GB per cpu.
-    # [memory per task] = [memory per cpu: 4 GB] * [cpu]
-    memory: 32G
-  env:
-    CIRRUS_CLONE_DEPTH: 50
-    optflags: '-O1'
-    debugflags: '-ggdb3'
-    RUBY_PREFIX: /tmp/ruby-prefix
-    RUBY_DEBUG: ci rgengc
-    RUBY_TESTOPTS: >-
-      -q
-      --color=always
-      --tty=no
-    matrix:
-      CC: clang-12
-      CC: gcc-11
-  id_script: id
-  set_env_script:
-    # Set `GNUMAKEFLAGS`, because the flags are GNU make specific. Note using
-    # the `make` environment variable used in compilers.yml causes some rubygems
-    # tests to fail.
-    # https://github.com/rubygems/rubygems/issues/4921
-    - echo "GNUMAKEFLAGS=-s -j$((1 + $CIRRUS_CPU))" >> "$CIRRUS_ENV"
-    - cat "$CIRRUS_ENV"
-  # Arm containers are executed in AWS's EKS, and it's not yet supporting IPv6
-  # See https://github.com/aws/containers-roadmap/issues/835
-  disable_ipv6_script: sudo ./tool/disable_ipv6.sh
-  autogen_script: ./autogen.sh
-  configure_script: >-
-    ./configure -C
-    --enable-debug-env
-    --disable-install-doc
-    --with-ext=-test-/cxxanyargs,+
-    --prefix="$RUBY_PREFIX"
-  make_extract-extlibs_script: make extract-extlibs
-  make_incs_script: make incs
-  make_script: make
-  make_leaked-globals_script: make leaked-globals
-  make_test_script: make test
-  make_install_script: make install
-  install_gems_for_test_script: $RUBY_PREFIX/bin/gem install --no-doc timezone tzinfo
-  make_test-tool_script: make test-tool
-  make_test-all_script: make test-all
-  make_test-spec_script: make test-spec
-
-# The following is to test YJIT on ARM64 CPUs available on Cirrus CI
-yjit_task:
-  name: Arm64 Graviton2 / $CC YJIT
-  auto_cancellation: $CIRRUS_BRANCH != 'master'
-  skip: "changesIncludeOnly('doc/**', '**.{md,rdoc,ronn,[1-8]}', '.document')"
-  arm_container:
-    # We use the arm64 images at https://github.com/ruby/ruby-ci-image/pkgs/container/ruby-ci-image .
-    image: ghcr.io/ruby/ruby-ci-image:$CC
-    # Define the used cpu core in each matrix task. We can use total 16 cpu
-    # cores in entire matrix. [cpu] = [total cpu: 16] / [number of tasks]
-    cpu: 8
-    # We can request maximum 4 GB per cpu.
-    # [memory per task] = [memory per cpu: 4 GB] * [cpu]
-    memory: 32G
-  env:
-    CIRRUS_CLONE_DEPTH: 50
-    optflags: '-O1'
-    debugflags: '-ggdb3'
-    RUBY_PREFIX: /tmp/ruby-prefix
-    RUBY_DEBUG: ci rgengc
-    RUBY_TESTOPTS: >-
-      -q
-      --color=always
-      --tty=no
-    matrix:
-      - CC: clang-12
-        configure: --enable-yjit=dev
-        rustup_init: --default-toolchain=1.58.0
-      - CC: gcc-11
-        configure: --enable-yjit
-  id_script: id
-  set_env_script:
-    # Set `GNUMAKEFLAGS`, because the flags are GNU make specific. Note using
-    # the `make` environment variable used in compilers.yml causes some rubygems
-    # tests to fail.
-    # https://github.com/rubygems/rubygems/issues/4921
-    - echo "GNUMAKEFLAGS=-s -j$((1 + $CIRRUS_CPU))" >> "$CIRRUS_ENV"
-    - echo RUST_BACKTRACE=1 >> "$CIRRUS_ENV"
-    - cat "$CIRRUS_ENV"
-  # Arm containers are executed in AWS's EKS, and it's not yet supporting IPv6
-  # See https://github.com/aws/containers-roadmap/issues/835
-  disable_ipv6_script: sudo ./tool/disable_ipv6.sh
-  install_rust_script:
-    - sudo apt-get update -y
-    - sudo apt-get install -y curl
-    - "curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh -s -- -y $rustup_init"
-  autogen_script: ./autogen.sh
-  configure_script: >-
-    source $HOME/.cargo/env && ./configure -C
-    --enable-debug-env
-    --disable-install-doc
-    --with-ext=-test-/cxxanyargs,+
-    --prefix="$RUBY_PREFIX"
-    $configure
-  make_miniruby_script: source $HOME/.cargo/env && make miniruby
-  make_bindgen_script: |
-    if [[ "$CC" = "clang-12" ]]; then
-      source $HOME/.cargo/env && make yjit-bindgen
-    else
-      echo "only running bindgen on clang image"
-    fi
-  boot_miniruby_script: ./miniruby --yjit-call-threshold=1 -e0
-  test_dump_insns_script: ./miniruby --yjit-call-threshold=1 --yjit-dump-insns -e0
-  output_stats_script: ./miniruby --yjit-call-threshold=1 --yjit-stats -e0
-  full_build_script: source $HOME/.cargo/env && make
-  cargo_test_script: source $HOME/.cargo/env && cd yjit && cargo test
-  make_test_script: source $HOME/.cargo/env && make test RUN_OPTS="--yjit-call-threshold=1 --yjit-verify-ctx"
-  make_test_all_script: source $HOME/.cargo/env && make test-all RUN_OPTS="--yjit-call-threshold=1 --yjit-verify-ctx" TESTOPTS="$RUBY_TESTOPTS"
-  make_test_spec_script: source $HOME/.cargo/env && make test-spec RUN_OPTS="--yjit-call-threshold=1 --yjit-verify-ctx"
-  clippy_script: source $HOME/.cargo/env && cd yjit && cargo clippy --all-targets --all-features
diff --git a/.document b/.document
index 3a6b0c238c..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
-mjit.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
 
@@ -48,7 +56,4 @@ COPYING.ja
 
 LEGAL
 
-# win32/README.win32 linked from README.md
-win32
-
 doc
diff --git a/.gdbinit b/.gdbinit
index 7657d240c5..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) @ (ROBJECT_EMBED_LEN_MAX+0)
+      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.heap.ptr : \
+            ((struct RString*)$regsrc)->as.embed.ary) @ $len
     set print address on
     printf " len:%ld ", $len
     if $flags & RUBY_FL_USER6
@@ -126,26 +108,26 @@ define rp
       printf "%sT_ARRAY%s: len=%ld ", $color_type, $color_end, $len
       printf "(embed) "
       if ($len == 0)
-	printf "{(empty)} "
+        printf "{(empty)} "
       else
-	print/x *((VALUE*)((struct RArray*)($arg0))->as.ary) @ $len
-	printf " "
+        print/x *((VALUE*)((struct RArray*)($arg0))->as.ary) @ $len
+        printf " "
       end
     else
       set $len = ((struct RArray*)($arg0))->as.heap.len
       printf "%sT_ARRAY%s: len=%ld ", $color_type, $color_end, $len
       if ($flags & RUBY_FL_USER2)
-	printf "(shared) shared="
-	output/x ((struct RArray*)($arg0))->as.heap.aux.shared_root
-	printf " "
+        printf "(shared) shared="
+        output/x ((struct RArray*)($arg0))->as.heap.aux.shared_root
+        printf " "
       else
-	printf "(ownership) capa=%ld ", ((struct RArray*)($arg0))->as.heap.aux.capa
+        printf "(ownership) capa=%ld ", ((struct RArray*)($arg0))->as.heap.aux.capa
       end
       if ($len == 0)
-	printf "{(empty)} "
+        printf "{(empty)} "
       else
-	print/x *((VALUE*)((struct RArray*)($arg0))->as.heap.ptr) @ $len
-	printf " "
+        print/x *((VALUE*)((struct RArray*)($arg0))->as.heap.ptr) @ $len
+        printf " "
       end
     end
     print (struct RArray *)($arg0)
@@ -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.heap.ptr : \
+            ((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.heap.ptr : \
+            ((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.
@@ -689,11 +671,6 @@ define nd_stts
 end
 
 
-define nd_entry
-  printf "%su3.entry%s: ", $color_highlite, $color_end
-  p ($arg0).u3.entry
-end
-
 define nd_vid
   printf "%su1.id%s: ", $color_highlite, $color_end
   p ($arg0).u1.id
@@ -868,22 +845,22 @@ define rb_numtable_entry
     set $rb_numtable_p = $rb_numtable_tbl->as.packed.bins
     while $rb_numtable_p && $rb_numtable_p < $rb_numtable_tbl->as.packed.bins+$rb_numtable_tbl->num_entries
       if $rb_numtable_p.k == $rb_numtable_id
-	set $rb_numtable_key = $rb_numtable_p.k
-	set $rb_numtable_rec = $rb_numtable_p.v
-	set $rb_numtable_p = 0
+        set $rb_numtable_key = $rb_numtable_p.k
+        set $rb_numtable_rec = $rb_numtable_p.v
+        set $rb_numtable_p = 0
       else
-	set $rb_numtable_p = $rb_numtable_p + 1
+        set $rb_numtable_p = $rb_numtable_p + 1
       end
     end
   else
     set $rb_numtable_p = $rb_numtable_tbl->as.big.bins[st_numhash($rb_numtable_id) % $rb_numtable_tbl->num_bins]
     while $rb_numtable_p
       if $rb_numtable_p->key == $rb_numtable_id
-	set $rb_numtable_key = $rb_numtable_p->key
-	set $rb_numtable_rec = $rb_numtable_p->record
-	set $rb_numtable_p = 0
+        set $rb_numtable_key = $rb_numtable_p->key
+        set $rb_numtable_rec = $rb_numtable_p->record
+        set $rb_numtable_p = 0
       else
-	set $rb_numtable_p = $rb_numtable_p->next
+        set $rb_numtable_p = $rb_numtable_p->next
       end
     end
   end
@@ -921,10 +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
@@ -961,7 +938,7 @@ define iseq
       set $operand_size = ((INSN*)($arg0))->operand_size
       set $operands = ((INSN*)($arg0))->operands
       while $i < $operand_size
-	rp $operands[$i++]
+        rp $operands[$i++]
       end
     end
   end
@@ -997,7 +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
@@ -1078,7 +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
@@ -1101,7 +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
@@ -1131,20 +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 ":"
@@ -1279,7 +1257,7 @@ document rb_count_objects
   Counts all objects grouped by type.
 end
 
-# Details: https://bugs.ruby-lang.org/projects/ruby-master/wiki/MachineInstructionsTraceWithGDB
+# Details: https://github.com/ruby/ruby/wiki/Machine-Instructions-Trace-with-GDB
 define trace_machine_instructions
   set logging enabled
   set height 0
@@ -1316,13 +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*)($arg0))->flags & RUBY_FL_EXIVAR ? "1" : "0"
@@ -1348,3 +1325,8 @@ define print_flags
   printf "RUBY_FL_USER17      : %s\n", ((struct RBasic*)($arg0))->flags & RUBY_FL_USER17 ? "1" : "0"
   printf "RUBY_FL_USER18      : %s\n", ((struct RBasic*)($arg0))->flags & RUBY_FL_USER18 ? "1" : "0"
 end
+
+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 6c5eac5a0f..d752612085 100644
--- a/.git-blame-ignore-revs
+++ b/.git-blame-ignore-revs
@@ -5,6 +5,16 @@
 
 # Expand tabs
 5b21e94bebed90180d8ff63dad03b8b948361089
+c5e9af9c9d890578182a21e7b71b50334cd5579e
+e63a2115f64433b21cb5dd67c5bf8b30f87ef293
+712ac99e4d0384a941c80a9f48f62943ba7d97c0
+d1474affa8e105bece209cc9d594bb0a989859e1
+2da92388b948821269b18d6b178a680f17e41750
+5062c0c621d887367af8a054e5e5d83d7ec57dd3
+
+# Indentation
+0e4bad888e605d424b9222ae0ca43f85c1634e5e
+61aa46c41648c6d1e9b0daa1a292de551fde78df
 
 # Enable Style/StringLiterals cop for RubyGems/Bundler
 d7ffd3fea402239b16833cc434404a7af82d44f3
@@ -21,3 +31,24 @@ f28287d34c03f472ffe90ea262bdde9affd4b965
 
 # Make benchmark indentation consistent
 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
new file mode 100644
index 0000000000..15dc097b6e
--- /dev/null
+++ b/.github/actions/setup/directories/action.yml
@@ -0,0 +1,205 @@
+name: Setup directories etc.
+description: >-
+  Set up the source code and build directories (plus some
+  environmental tweaks)
+
+inputs:
+  srcdir:
+    required: false
+    default: ${{ github.workspace }}
+    description: >-
+      Directory to (re-)checkout source codes.  This will be created
+      if absent.  If there is no `configure` file that is also
+      generated inside.
+
+  builddir:
+    required: false
+    default: ${{ github.workspace }}
+    description: >-
+      Where binaries and other generated contents go.  This will be
+      created if absent.
+
+  make-command:
+    required: false
+    type: string
+    default: 'make'
+    description: >-
+      The command of `make`.
+
+  makeup:
+    required: false
+    type: boolean
+    # Note that `default: false` evaluates to a string constant
+    # `'false'`, which is a truthy value :sigh:
+    # https://github.com/actions/runner/issues/2238
+    default: ''
+    description: >-
+      If set to true, additionally runs `make up`.
+
+  checkout:
+    required: false
+    type: boolean
+    default: true
+    description: >-
+      If set to '' (false), skip running actions/checkout. This is useful when
+      you don't want to overwrite a GitHub token that is already set up.
+
+  dummy-files:
+    required: false
+    type: boolean
+    default: ''
+    description: >-
+      If set to true, creates dummy files in build dir.
+
+  fetch-depth:
+    required: false
+    default: '1'
+    description: The depth of commit history fetched from the remote repository
+
+  clean:
+    required: false
+    type: boolean
+    default: ''
+    description: >-
+      If set to true, clean build directory.
+
+outputs: {} # nothing?
+
+runs:
+  using: composite
+
+  steps:
+    # Note that `shell: bash` works on both Windows and Linux, but not
+    # `shell: sh`.  This is because GitHub hosted Windows runners have
+    # their bash manually installed.
+    - shell: bash
+      run: |
+        mkdir -p "${INPUT_SRCDIR}"
+        mkdir -p "${INPUT_BUILDDIR}"
+      env:
+        INPUT_SRCDIR: ${{ inputs.srcdir }}
+        INPUT_BUILDDIR: ${{ inputs.builddir }}
+
+    # Did you know that actions/checkout works without git(1)?  We are
+    # checking that here.
+    - id: which
+      shell: bash
+      run: |
+        echo "git=`command -v git`" >> "$GITHUB_OUTPUT"
+        echo "sudo=`sudo true && command -v sudo`" >> "$GITHUB_OUTPUT"
+        echo "autoreconf=`command -v autoreconf`" >> "$GITHUB_OUTPUT"
+
+    - if: steps.which.outputs.git
+      shell: bash
+      run: |
+        git config --global core.autocrlf false
+        git config --global core.eol lf
+        git config --global advice.detachedHead 0
+        git config --global init.defaultBranch garbage
+
+    - if: inputs.checkout
+      uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+      with:
+        path: ${{ inputs.srcdir }}
+        fetch-depth: ${{ inputs.fetch-depth }}
+        persist-credentials: false
+
+    - uses: actions/cache@27d5ce7f107fe9357f9df03efb73ab90386fccae # v5.0.5
+      with:
+        path: ${{ inputs.srcdir }}/.downloaded-cache
+        key: ${{ runner.os }}-${{ runner.arch }}-downloaded-cache
+
+    - if: steps.which.outputs.autoreconf
+      shell: bash
+      working-directory: ${{ inputs.srcdir }}
+      run: ./autogen.sh --install
+
+    # This is for MinGW.
+    - if: runner.os == 'Windows'
+      shell: bash
+      run: echo "GNUMAKEFLAGS=-j$((2 * NUMBER_OF_PROCESSORS))" >> $GITHUB_ENV # zizmor: ignore[github-env]
+
+    - if: runner.os == 'Linux'
+      shell: bash
+      run: echo "GNUMAKEFLAGS=-sj$((1 + $(nproc)))" >> "$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" # zizmor: ignore[github-env]
+
+    - if: inputs.makeup
+      shell: bash
+      working-directory: ${{ inputs.srcdir }}
+      run: |
+        touch config.status .rbconfig.time
+        for mk in Makefile GNUmakefile; do
+          sed -f tool/prereq.status template/$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 .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 $HOME/.config || :
+        declare -a dirs # -A is not supported by old bash, e.g. macos
+        SAVE_IFS="$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
+        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
new file mode 100644
index 0000000000..9cd37a9b12
--- /dev/null
+++ b/.github/actions/setup/macos/action.yml
@@ -0,0 +1,29 @@
+name: Setup macOS environment
+description: >-
+  Installs necessary packages via Homebrew.
+
+inputs: {} # nothing?
+
+outputs: {} # nothing?
+
+runs:
+  using: composite
+
+  steps:
+    - name: brew
+      shell: bash
+      run: |
+        brew install --quiet jemalloc gmp libffi openssl@3 zlib autoconf automake libtool
+
+    - name: Set ENV
+      shell: bash
+      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
new file mode 100644
index 0000000000..5209ccc03f
--- /dev/null
+++ b/.github/actions/setup/ubuntu/action.yml
@@ -0,0 +1,72 @@
+name: Setup ubuntu environment
+description: >-
+  At the beginning there was no way but to copy & paste `apt-get`
+  everywhere.  But now that we have composite actions, it seems better
+  merge them into one.
+
+inputs:
+  arch:
+    required: false
+    default: ''
+    description: >-
+      Architecture.  Because we run this on a GitHub-hosted runner
+      acceptable value for this input is very limited.
+
+outputs:
+  arch:
+    value: ${{ steps.uname.outputs.uname }}
+    description: >-
+      Actual architecture.  This could be different from the one
+      passed to the `inputs.arch`.  For instance giving `i386` to this
+      action yields `i686`.
+
+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" # zizmor: ignore[github-env]
+      env:
+        setarch: ${{ steps.uname.outputs.setarch }} # validated
+
+    - name: dpkg setup
+      shell: bash
+      run: sudo dpkg --add-architecture "${dpkg}"
+      # `dpkg` is valid, also `uname`.
+      if: ${{ inputs.arch }}
+      env:
+        dpkg: ${{ steps.uname.outputs.dpkg }}
+
+    - name: apt-get
+      shell: bash
+      env:
+        arch: ${{ inputs.arch && format(':{0}', steps.uname.outputs.dpkg) || '' }}
+      run: |
+        set -x
+        sudo apt-get update -qq || :
+        sudo apt-get install --no-install-recommends -qq -y -o=Dpkg::Use-Pty=0 \
+        ${arch:+cross}build-essential${arch/:/-} \
+        libssl-dev${arch} libyaml-dev${arch} libreadline6-dev${arch} \
+        zlib1g-dev${arch} libncurses5-dev${arch} libffi-dev${arch} \
+        autoconf ruby
+        sudo apt-get install -qq -y pkg-config${arch} || :
diff --git a/.github/actions/slack/action.yml b/.github/actions/slack/action.yml
new file mode 100644
index 0000000000..6f89bef11a
--- /dev/null
+++ b/.github/actions/slack/action.yml
@@ -0,0 +1,51 @@
+name: Post a message to slack
+description: >-
+  We have our ruby/action-slack webhook.  However its arguments are
+  bit verbose to be listed in every workflow files.  Better merge them
+  into one.
+
+inputs:
+  SLACK_WEBHOOK_URL:
+    required: true
+    description: >-
+      The URL to post the payload.  This is an input because it tends
+      to be stored in a secrets vault and a composite action cannot
+      look into one.
+
+  label:
+    required: false
+    description: >-
+      Human-readable description of the run, something like "DEBUG=1".
+      This need not be unique among runs.
+
+  event_name:
+    required: false
+    default: 'push'
+    description: >-
+      Target event to trigger notification. Notify only push by default.
+
+  extra_channel_id:
+    required: false
+    description: >-
+      Slack channel ID to notify besides #alerts and #alerts-emoji.
+
+outputs: {} # Nothing?
+
+runs:
+  using: composite
+
+  steps:
+    - uses: ruby/action-slack@d260b61aa817726d5bedd22dd6cc305787fa4cdd # v4.0.0
+      with:
+        payload: |
+          {
+            "ci": "GitHub Actions",
+            "env": "${{ github.workflow }}${{ inputs.label && format(' / {0}', inputs.label) }}",
+            "url": "https://github.com/${{ 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 == inputs.event_name && startsWith(github.repository, 'ruby/') }}
diff --git a/.github/auto_request_review.yml b/.github/auto_request_review.yml
index f694a1c72f..9e20cb7459 100644
--- a/.github/auto_request_review.yml
+++ b/.github/auto_request_review.yml
@@ -1,14 +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]
-  '.github/workflows/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
index 91f82b842b..f5d33545c1 100644
--- a/.github/codeql/codeql-config.yml
+++ b/.github/codeql/codeql-config.yml
@@ -1,3 +1,22 @@
-name: "CodeQL config for the Ruby language"
-
-languages: cpp
+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 bc63aca35b..57da742e5c 100644
--- a/.github/dependabot.yml
+++ b/.github/dependabot.yml
@@ -1,6 +1,29 @@
 version: 2
 updates:
   - package-ecosystem: 'github-actions'
-    directory: '/'
+    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
new file mode 100644
index 0000000000..5991165d43
--- /dev/null
+++ b/.github/workflows/annocheck.yml
@@ -0,0 +1,111 @@
+name: Annocheck
+
+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:
+  compile:
+    name: test-annocheck
+
+    runs-on: ubuntu-latest
+
+    container:
+      image: ghcr.io/ruby/ruby-ci-image:gcc-11
+      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.pull_request.user.login == 'dependabot[bot]')
+      )}}
+
+    env:
+      CONFIGURE_TTY: never
+      GITPULLOPTIONS: --no-tags origin ${{ github.ref }}
+      RUBY_DEBUG: ci rgengc
+      RUBY_TESTOPTS: >-
+        -q
+        --color=always
+        --tty=no
+      # FIXME: Drop skipping options
+      # https://bugs.ruby-lang.org/issues/18061
+      # https://sourceware.org/annobin/annobin.html/Test-pie.html
+      TEST_ANNOCHECK_OPTS: '--skip-pie --skip-gaps'
+
+    steps:
+      - run: id
+        working-directory:
+
+      - 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
+
+      - 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
+        run: >
+          ../src/configure -C
+          --enable-debug-env
+          --disable-install-doc
+          --with-ext=-test-/cxxanyargs,+
+          --without-valgrind
+          --without-jemalloc
+          --without-gmp
+          --with-gcc="gcc-11 -fcf-protection -Wa,--generate-missing-build-notes=yes"
+          --enable-shared
+          debugflags=-ggdb3
+          optflags=-O2
+          LDFLAGS=-Wl,-z,now
+
+      - run: make showflags
+
+      - run: make
+
+      - run: make test-annocheck
+
+      - 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/auto_request_review.yml b/.github/workflows/auto_request_review.yml
index 340aae4391..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@5f91f424cabb3211c669e49e79da8363f7df395b # v0.10.0
+        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 7ba87944c2..9e7720f659 100644
--- a/.github/workflows/baseruby.yml
+++ b/.github/workflows/baseruby.yml
@@ -4,17 +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:
 
 concurrency:
   group: ${{ github.workflow }} / ${{ startsWith(github.event_name, 'pull') && github.ref_name || github.sha }}
@@ -26,49 +29,48 @@ permissions:
 jobs:
   baseruby:
     name: BASERUBY
-    runs-on: ubuntu-20.04
-    if: ${{ !contains(github.event.head_commit.message, '[DOC]') && !contains(github.event.pull_request.labels.*.name, 'Documentation') }}
+
+    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]')
+      )}}
+
     strategy:
       matrix:
         ruby:
-          - ruby-2.2
-#         - ruby-2.3
-#         - ruby-2.4
-#         - ruby-2.5
-#         - ruby-2.6
-#         - ruby-2.7
-          - ruby-3.0
           - ruby-3.1
           - ruby-3.2
+          - ruby-3.3
 
     steps:
-      - uses: actions/checkout@ac593985615ec2ede58e132d2e21d2b1cbd6127c # v3.3.0
-      - uses: actions/cache@627f0f41f6904a5b1efbaed9f96d9eb58e92e920 # v3.2.4
-        with:
-          path: .downloaded-cache
-          key: downloaded-cache
-      - uses: ruby/setup-ruby@ee26e27437bde475b19a6bf8cb73c9fa658876a2 # v1.134.0
+      - uses: ruby/setup-ruby@afeafc3d1ab54a631816aba4c914a0081c12ff2f # v1.310.0
         with:
           ruby-version: ${{ matrix.ruby }}
           bundler: none
-      - run: echo "GNUMAKEFLAGS=-j$((1 + $(nproc --all)))" >> $GITHUB_ENV
-      - run: sudo apt-get install build-essential autoconf bison libyaml-dev
-      - run: ./autogen.sh
+
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with:
+          persist-credentials: false
+
+      - uses: ./.github/actions/setup/ubuntu
+
+      - uses: ./.github/actions/setup/directories
+        with:
+          makeup: true
+
       - run: ./configure --disable-install-doc
-      - run: make common-srcs
-      - run: make incs
+
       - run: make all
+
       - run: make test
-      - uses: ruby/action-slack@b6882ea6ef8f556f9f9af9ec1220d3f1ced74acf # v3.0.0
+
+      - uses: ./.github/actions/slack
         with:
-          payload: |
-            {
-              "ci": "GitHub Actions",
-              "env": "${{ github.workflow }} / BASERUBY @ ${{ matrix.ruby }}",
-              "url": "https://github.com/${{ github.repository }}/actions/runs/${{ github.run_id }}",
-              "commit": "${{ github.sha }}",
-              "branch": "${{ github.ref_name }}"
-            }
-        env:
+          label: ${{ matrix.ruby }}
           SLACK_WEBHOOK_URL: ${{ secrets.SIMPLER_ALERTS_URL }} # ruby-lang slack: ruby/simpler-alerts-bot
-        if: ${{ failure() && github.event_name == 'push' }}
+        if: ${{ failure() }}
diff --git a/.github/workflows/bundled_gems.yml b/.github/workflows/bundled_gems.yml
index 2850b18d6f..d329ee9b4b 100644
--- a/.github/workflows/bundled_gems.yml
+++ b/.github/workflows/bundled_gems.yml
@@ -1,131 +1,186 @@
 name: bundled_gems
 
+env:
+  UPDATE_ENABLED: true
+
 on:
   push:
+    branches: ['master']
     paths:
       - '.github/workflows/bundled_gems.yml'
       - 'gems/bundled_gems'
   pull_request:
+    branches: ['master']
     paths:
       - '.github/workflows/bundled_gems.yml'
       - 'gems/bundled_gems'
+  merge_group:
   schedule:
     - cron: '45 6 * * *'
   workflow_dispatch:
 
-permissions:  # added using https://github.com/step-security/secure-workflows
+permissions: # added using https://github.com/step-security/secure-workflows
   contents: read
 
 jobs:
   update:
     permissions:
-      contents: write  # for Git to git push
+      contents: write # for Git to git push
+
     if: ${{ github.event_name != 'schedule' || github.repository == 'ruby/ruby' }}
+
     name: update ${{ github.workflow }}
+
     runs-on: ubuntu-latest
+
     steps:
-      - name: git config
-        run: |
-          git config --global advice.detachedHead 0
-          git config --global init.defaultBranch garbage
+      - 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: |
-          echo "GNUMAKEFLAGS=-j$((1 + $(nproc --all)))" >> $GITHUB_ENV
           echo "TODAY=$(date +%F)" >> $GITHUB_ENV
 
-      - uses: actions/checkout@ac593985615ec2ede58e132d2e21d2b1cbd6127c # v3.3.0
-
-      - uses: actions/cache@627f0f41f6904a5b1efbaed9f96d9eb58e92e920 # v3.2.4
-        with:
-          path: .downloaded-cache
-          key: downloaded-cache-${{ github.sha }}
-          restore-keys: |
-            downloaded-cache
-
       - name: Download previous gems list
         run: |
-          data=bundled_gems.json
           mkdir -p .downloaded-cache
-          ln -s .downloaded-cache/$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
+          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
         run: |
-          git add -- NEWS.md
-          git diff --no-ext-diff --ignore-submodules --quiet -- gems/bundled_gems
-        continue-on-error: true
+          news= gems=
+          git diff --color --no-ext-diff --ignore-submodules --exit-code -- NEWS.md ||
+          news=true
+          git diff --color --no-ext-diff --ignore-submodules --exit-code -- gems/bundled_gems ||
+          gems=true
+          git add -- NEWS.md gems/bundled_gems
+          echo news=$news >> $GITHUB_OUTPUT
+          echo gems=$gems >> $GITHUB_OUTPUT
+          echo update=${news:-$gems} >> $GITHUB_OUTPUT
 
-      - name: Install libraries
+      - name: Commit
+        id: commit
         run: |
-          set -x
-          sudo apt-get update -q || :
-          sudo apt-get install --no-install-recommends -q -y build-essential libssl-dev libyaml-dev libreadline6-dev zlib1g-dev libncurses5-dev libffi-dev bison autoconf ruby
-        if: ${{ steps.diff.outcome == 'failure' }}
+          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 }}
 
       - name: Build
         run: |
           ./autogen.sh
           ./configure -C --disable-install-doc
           make
-        if: ${{ steps.diff.outcome == 'failure' }}
+        if: ${{ steps.diff.outputs.gems }}
 
       - name: Prepare bundled gems
         run: |
           make -s prepare-gems
-        if: ${{ steps.diff.outcome == 'failure' }}
+        if: ${{ steps.diff.outputs.gems }}
 
       - name: Test bundled gems
         run: |
           make -s test-bundled-gems
-          git add -- gems/bundled_gems
         timeout-minutes: 30
         env:
-          RUBY_TESTOPTS: "-q --tty=no"
-          TEST_BUNDLED_GEMS_ALLOW_FAILURES: ""
-        if: ${{ steps.diff.outcome == 'failure' }}
-
-      - name: Show diffs
-        id: show
-        run: |
-          git diff --cached --color --no-ext-diff --ignore-submodules --exit-code --
-        continue-on-error: true
+          RUBY_TESTOPTS: '-q --tty=no'
+          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 at "
-          if [ ${{ steps.diff.outcome }} = success ]; then
-            git commit --message="${message}${GITHUB_SHA:0:30} [ci skip]"
-          else
-            git commit --message="${message}${TODAY}"
-          fi
           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.show.outcome == 'failure' }}
-
-      - uses: ruby/action-slack@b6882ea6ef8f556f9f9af9ec1220d3f1ced74acf # v3.0.0
+        if: >-
+          ${{
+          github.repository == 'ruby/ruby' &&
+          !startsWith(github.event_name, 'pull') &&
+          steps.commit.outcome == 'success'
+          }}
+
+      - uses: ./.github/actions/slack
         with:
-          payload: |
-            {
-              "ci": "GitHub Actions",
-              "env": "${{ github.workflow }} / update",
-              "url": "https://github.com/${{ github.repository }}/actions/runs/${{ github.run_id }}",
-              "commit": "${{ github.sha }}",
-              "branch": "${{ github.ref_name }}"
-            }
-        env:
           SLACK_WEBHOOK_URL: ${{ secrets.SIMPLER_ALERTS_URL }} # ruby-lang slack: ruby/simpler-alerts-bot
-        if: ${{ failure() && github.event_name == 'push' }}
+        if: ${{ failure() }}
diff --git a/.github/workflows/check_dependencies.yml b/.github/workflows/check_dependencies.yml
index b843d66cc6..a120dde7e5 100644
--- a/.github/workflows/check_dependencies.yml
+++ b/.github/workflows/check_dependencies.yml
@@ -3,17 +3,13 @@ on:
   push:
     paths-ignore:
       - 'doc/**'
-      - '**/man'
+      - '**/man/*'
       - '**.md'
       - '**.rdoc'
       - '**/.document'
+      - '.*.yml'
   pull_request:
-    paths-ignore:
-      - 'doc/**'
-      - '**/man'
-      - '**.md'
-      - '**.rdoc'
-      - '**/.document'
+  merge_group:
 
 concurrency:
   group: ${{ github.workflow }} / ${{ startsWith(github.event_name, 'pull') && github.ref_name || github.sha }}
@@ -24,49 +20,42 @@ permissions:
 
 jobs:
   update-deps:
+    name: Dependency checks
+
     strategy:
       matrix:
-        os: [ubuntu-20.04]
+        os: [ubuntu-latest]
       fail-fast: true
+
     runs-on: ${{ matrix.os }}
-    if: ${{ !contains(github.event.head_commit.message, '[DOC]') && !contains(github.event.pull_request.labels.*.name, 'Documentation') }}
+
     steps:
-      - name: Install libraries
-        run: |
-          set -x
-          sudo apt-get update -q || :
-          sudo apt-get install --no-install-recommends -q -y build-essential libssl-dev libyaml-dev libreadline6-dev zlib1g-dev libncurses5-dev libffi-dev bison autoconf ruby
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with:
+          persist-credentials: false
+
+      - uses: ./.github/actions/setup/ubuntu
         if: ${{ contains(matrix.os, 'ubuntu') }}
-      - name: Install libraries
-        run: |
-          brew upgrade
-          brew install gmp libffi openssl@1.1 zlib autoconf automake libtool readline
+
+      - uses: ./.github/actions/setup/macos
         if: ${{ contains(matrix.os, 'macos') }}
-      - name: git config
-        run: |
-          git config --global advice.detachedHead 0
-          git config --global init.defaultBranch garbage
-      - uses: actions/checkout@ac593985615ec2ede58e132d2e21d2b1cbd6127c # v3.3.0
-      - uses: actions/cache@627f0f41f6904a5b1efbaed9f96d9eb58e92e920 # v3.2.4
+
+      - uses: ./.github/actions/setup/directories
+
+      - uses: ruby/setup-ruby@afeafc3d1ab54a631816aba4c914a0081c12ff2f # v1.310.0
         with:
-          path: .downloaded-cache
-          key: downloaded-cache
-      - run: ./autogen.sh
+          ruby-version: '3.1'
+          bundler: none
+
       - name: Run configure
         run: ./configure -C --disable-install-doc --disable-rubygems --with-gcc 'optflags=-O0' 'debugflags=-save-temps=obj -g'
-      - run: make all golf
-      - run: ruby tool/update-deps --fix
-      - run: git diff --no-ext-diff --ignore-submodules --exit-code
-      - uses: ruby/action-slack@b6882ea6ef8f556f9f9af9ec1220d3f1ced74acf # v3.0.0
+
+      - run: make fix-depends
+
+      - run: git diff --color --no-ext-diff --ignore-submodules --exit-code
+
+      - uses: ./.github/actions/slack
         with:
-          payload: |
-            {
-              "ci": "GitHub Actions",
-              "env": "${{ matrix.os }} / Dependencies need to update",
-              "url": "https://github.com/${{ github.repository }}/actions/runs/${{ github.run_id }}",
-              "commit": "${{ github.sha }}",
-              "branch": "${{ github.ref_name }}"
-            }
-        env:
+          label: ${{ matrix.os }} / Dependencies need to update
           SLACK_WEBHOOK_URL: ${{ secrets.SIMPLER_ALERTS_URL }} # ruby-lang slack: ruby/simpler-alerts-bot
-        if: ${{ failure() && github.event_name == 'push' }}
+        if: ${{ failure() }}
diff --git a/.github/workflows/check_misc.yml b/.github/workflows/check_misc.yml
index e9e14af2eb..cb1642b9e2 100644
--- a/.github/workflows/check_misc.yml
+++ b/.github/workflows/check_misc.yml
@@ -1,5 +1,5 @@
-name: Miscellaneous checks
-on: [push, pull_request]
+name: Misc
+on: [push, pull_request, merge_group]
 
 concurrency:
   group: ${{ github.workflow }} / ${{ startsWith(github.event_name, 'pull') && github.ref_name || github.sha }}
@@ -10,90 +10,142 @@ permissions:
 
 jobs:
   checks:
+    name: Miscellaneous checks
+
     permissions:
-      contents: write  # for Git to git push
+      contents: write # for Git to git push
+
     runs-on: ubuntu-latest
+
     steps:
-      - uses: actions/checkout@ac593985615ec2ede58e132d2e21d2b1cbd6127c # v3.3.0
-      - name: Check if C-sources are US-ASCII
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with:
+          token: ${{ (github.repository == 'ruby/ruby' && !startsWith(github.event_name, 'pull')) && secrets.MATZBOT_AUTO_UPDATE_TOKEN || secrets.GITHUB_TOKEN }}
+          persist-credentials: false
+
+      - uses: ruby/setup-ruby@afeafc3d1ab54a631816aba4c914a0081c12ff2f # v1.310.0
+        with:
+          ruby-version: head
+
+      - uses: ./.github/actions/setup/directories
+        with:
+          makeup: true
+          # Skip overwriting MATZBOT_AUTO_UPDATE_TOKEN
+          checkout: '' # false (ref: https://github.com/actions/runner/issues/2238)
+
+      - name: Re-generate Makefiles
         run: |
-          ! grep -r -n '[^	 -~]' -- *.[chy] include internal win32/*.[ch]
-      - name: Check for trailing spaces
+          # config.status needs to run as a shell script
+          { echo ':&&exit'; cat tool/prereq.status; } > config.status
+          : # same as actions/setup/directories/action.yml
+          for mk in Makefile GNUmakefile; do
+            sed -f tool/prereq.status template/$mk.in > $mk
+          done
+
+      - name: Check for code styles
         run: |
-          ! git grep -n '[	 ]$' -- '*.rb' '*.[chy]' '*.rs'
-          ! git grep -n '^[	 ][	 ]*$' -- '*.md'
+          set -x
+          ruby tool/auto-style.rb "$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: ${{ github.repository == 'ruby/ruby' && startsWith(github.event_name, 'pull') }}
+
+      - name: Check if date in man pages is up-to-date
+        run: |
+          git fetch origin --depth=1 "${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: |
-          ! git grep -n '\${[A-Za-z_0-9]*/' -- configure.ac
+          git grep -n '\${[A-Za-z_0-9]*/' -- configure.ac && exit 1 || :
+
       - name: Check for header macros
         run: |
-          ! for header in ruby/*.h; do \
-            git grep -l -F -e $header -e HAVE_`echo $header | tr a-z./ A-Z__` -- . > /dev/null || echo $header
-          done | grep -F .
+          fail=
+          for header in ruby/*.h; do
+            git grep -l -F -e $header -e HAVE_`echo $header | tr a-z./ A-Z__` -- . > /dev/null && continue
+            fail=1
+            echo $header
+          done
+          exit $fail
         working-directory: include
 
-      - uses: actions/cache@627f0f41f6904a5b1efbaed9f96d9eb58e92e920 # v3.2.4
-        with:
-          path: .downloaded-cache
-          key: downloaded-cache-${{ github.sha }}
-          restore-keys: |
-            downloaded-cache
+      - id: now
+        run: |
+          date +"mon=%-m"%n"day=%-d" >> $GITHUB_OUTPUT
+        env:
+          TZ: Asia/Tokyo
 
-      - name: Download previous gems list
+      - id: deprecation
         run: |
-          data=default_gems.json
-          mkdir -p .downloaded-cache
-          ln -s .downloaded-cache/$data .
-          curl -O -R -z ./$data https://stdgems.org/$data
+          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: Make default gems list
+      - name: Check if to generate documents
+        id: rdoc
         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}
-
-      - name: Maintain updated gems list in NEWS
+          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: ${{ steps.rdoc.outputs.ref != '' }}
+
+      - name: Generate rdoc scripts
         run: |
-          ruby tool/update-NEWS-gemlist.rb default
+          set -x
+          gempath=$(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: Check diffs
-        id: diff
+      - name: Core docs coverage
         run: |
-          git diff --color --no-ext-diff --ignore-submodules --exit-code NEWS.md
-        continue-on-error: true
-      - name: Commit
+          make XRUBY=ruby RDOC_DEPENDS= RBCONFIG=update-rbconfig rdoc-coverage
+
+      - 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
-        if: ${{ github.repository == 'ruby/ruby' && !startsWith(github.event_name, 'pull') && steps.diff.outcome == 'failure' }}
+          make XRUBY=ruby RDOC_DEPENDS= RBCONFIG=update-rbconfig HTMLOUT=html html
+          echo htmlout=ruby-html-${GITHUB_SHA:0:10} >> $GITHUB_OUTPUT
+        # Generate only when document commit/PR
+        if: >-
+          ${{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')
+          }}
 
-      - uses: ruby/action-slack@b6882ea6ef8f556f9f9af9ec1220d3f1ced74acf # v3.0.0
+      - name: Upload docs
+        uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7.0.1
+        with:
+          path: html
+          name: ${{ steps.docs.outputs.htmlout }}
+        if: ${{ steps.docs.outcome == 'success' }}
+
+      - uses: ./.github/actions/slack
         with:
-          payload: |
-            {
-              "ci": "GitHub Actions",
-              "env": "${{ github.workflow }}",
-              "url": "https://github.com/${{ github.repository }}/actions/runs/${{ github.run_id }}",
-              "commit": "${{ github.sha }}",
-              "branch": "${{ github.ref_name }}"
-            }
-        env:
           SLACK_WEBHOOK_URL: ${{ secrets.SIMPLER_ALERTS_URL }} # ruby-lang slack: ruby/simpler-alerts-bot
-        if: ${{ failure() && github.event_name == 'push' }}
+        if: ${{ failure() }}
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/cirrus-notify.yml b/.github/workflows/cirrus-notify.yml
deleted file mode 100644
index 55d64b7f39..0000000000
--- a/.github/workflows/cirrus-notify.yml
+++ /dev/null
@@ -1,46 +0,0 @@
-on:
-  check_suite:
-    type: ['completed']
-name: Cirrus CI failure notification
-
-permissions:
-  contents: read
-
-jobs:
-  cirrus-notify:
-    name: After Cirrus CI Failure
-    if: >-
-      github.event.check_suite.app.name == 'Cirrus CI'
-      && github.event.check_suite.conclusion != 'success'
-      && github.event.check_suite.conclusion != 'cancelled'
-      && github.event.check_suite.conclusion != 'skipped'
-      && github.event.check_suite.head_branch == 'master'
-    runs-on: ubuntu-latest
-    steps:
-      - uses: octokit/request-action@89a1754fe82ca777b044ca8e79e9881a42f15a93 # v2.1.7
-        id: get_failed_check_run
-        with:
-          route: GET /repos/${{ github.repository }}/check-suites/${{ github.event.check_suite.id }}/check-runs?status=completed
-          mediaType: '{"previews": ["antiope"]}'
-        env:
-          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
-      - name: Dump GitHub context
-        env:
-          GITHUB_CONTEXT: ${{ toJson(github) }}
-        run: echo "$GITHUB_CONTEXT"
-      - name: Dump check_runs
-        env:
-          CHECK_RUNS: ${{ steps.get_failed_check_run.outputs.data }}
-        run: echo "$CHECK_RUNS"
-      - uses: ruby/action-slack@b6882ea6ef8f556f9f9af9ec1220d3f1ced74acf # v3.0.0
-        with:
-          payload: |
-            {
-              "ci": "Cirrus CI",
-              "env": "Cirrus CI",
-              "url": "${{ fromJson(steps.get_failed_check_run.outputs.data).check_runs[0].html_url }}",
-              "commit": "${{ github.event.check_suite.head_commit.id }}",
-              "branch": "${{ github.event.check_suite.head_branch }}"
-            }
-        env:
-          SLACK_WEBHOOK_URL: ${{ secrets.SIMPLER_ALERTS_URL }} # ruby-lang slack: ruby/simpler-alerts-bot
diff --git a/.github/workflows/codeql-analysis.yml b/.github/workflows/codeql-analysis.yml
deleted file mode 100644
index f500b33ad1..0000000000
--- a/.github/workflows/codeql-analysis.yml
+++ /dev/null
@@ -1,74 +0,0 @@
-name: "Code scanning - action"
-
-on:
-  # push:
-  #   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:
-  CodeQL-Build:
-
-    # CodeQL runs on ubuntu-latest and windows-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
-    runs-on: ubuntu-latest
-    # CodeQL fails to run pull requests from dependabot due to missing write access to upload results.
-    if: ${{ !contains(github.event.head_commit.message, '[DOC]') && !contains(github.event.pull_request.labels.*.name, 'Documentation') && github.event.head_commit.pusher.name != 'dependabot[bot]' }}
-
-    env:
-      enable_install_doc: no
-
-    steps:
-    - name: Install libraries
-      run: |
-        set -x
-        sudo apt-get update -q || :
-        sudo apt-get install --no-install-recommends -q -y build-essential libssl-dev libyaml-dev libreadline6-dev zlib1g-dev libncurses5-dev libffi-dev bison autoconf ruby
-
-    - name: Checkout repository
-      uses: actions/checkout@ac593985615ec2ede58e132d2e21d2b1cbd6127c # v3.3.0
-
-    - uses: actions/cache@627f0f41f6904a5b1efbaed9f96d9eb58e92e920 # v3.2.4
-      with:
-        path: .downloaded-cache
-        key: downloaded-cache
-
-    - name: Remove an obsolete rubygems vendored file
-      run: sudo rm /usr/lib/ruby/vendor_ruby/rubygems/defaults/operating_system.rb
-
-    - name: Initialize CodeQL
-      uses: github/codeql-action/init@3ebbd71c74ef574dbc558c82f70e52732c8b44fe # v2.2.1
-      with:
-        config-file: ./.github/codeql/codeql-config.yml
-
-    - name: Set ENV
-      run: echo "GNUMAKEFLAGS=-j$((1 + $(nproc --all)))" >> $GITHUB_ENV
-
-    - name: Autobuild
-      uses: github/codeql-action/autobuild@3ebbd71c74ef574dbc558c82f70e52732c8b44fe # v2.2.1
-
-    - name: Perform CodeQL Analysis
-      uses: github/codeql-action/analyze@3ebbd71c74ef574dbc558c82f70e52732c8b44fe # v2.2.1
diff --git a/.github/workflows/compilers.yml b/.github/workflows/compilers.yml
index 992ba831cf..f747b7fd03 100644
--- a/.github/workflows/compilers.yml
+++ b/.github/workflows/compilers.yml
@@ -1,282 +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:
 
 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-15
-  append_cc: ''
+permissions:
+  contents: read
 
-  # -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'
+# Each job is split so that they roughly take 30min to run through.
+jobs:
+  compile-if:
+    name: 'omnibus compilations, trigger'
+    runs-on: ubuntu-latest
+    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: true
+        working-directory:
+
+  compile1:
+    name: 'omnibus compilations, #1'
+    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 }
+      # 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:
+          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 } }
 
-  # -g0 disables backtraces when SEGV.  Do not set that.
-  debugflags: '-ggdb3'
+  compile2:
+    name: 'omnibus compilations, #2'
+    runs-on: ubuntu-latest
+    needs: compile-if
+    if: ${{ needs.compile-if.result == 'success' }}
+    timeout-minutes: 60
 
-  default_configure: >-
-    --enable-debug-env
-    --disable-install-doc
-    --with-ext=-test-/cxxanyargs,+
-  append_configure: >-
-    --without-valgrind
-    --without-jemalloc
-    --without-gmp
+    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 }
 
-  CONFIGURE_TTY: never
-  GITPULLOPTIONS: --no-tags origin ${{github.ref}}
-  RUBY_DEBUG: ci rgengc
-  RUBY_TESTOPTS: >-
-    -q
-    --color=always
-    --tty=no
+  compile3:
+    name: 'omnibus compilations, #3'
+    runs-on: ubuntu-latest
+    needs: compile-if
+    if: ${{ needs.compile-if.result == 'success' }}
+    timeout-minutes: 60
 
-permissions:
-  contents: read
+    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 }
 
-jobs:
-  compile:
-    strategy:
-      fail-fast: false
-      matrix:
-        env:
-          - {}
-        entry:
-          - { 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-6,     env: { default_cc: gcc-6 } }
-          - { name: gcc-5,     env: { default_cc: gcc-5 } }
-          - { name: gcc-4.8,   env: { default_cc: gcc-4.8 } }
-          - name: 'gcc-11 LTO'
-            container: gcc-11
-            env:
-              default_cc: 'gcc-11 -flto=auto -ffat-lto-objects'
-              optflags: '-O2'
-            shared: disable
-            # check: true
-          - name: 'gcc-11 annocheck'
-            container: gcc-11
-            env:
-              # Minimal flags to pass the check.
-              default_cc: 'gcc-11 -fcf-protection -Wa,--generate-missing-build-notes=yes'
-              optflags: '-O2'
-              LDFLAGS: '-Wl,-z,now'
-              # FIXME: Drop skipping options
-              # https://bugs.ruby-lang.org/issues/18061
-              # https://sourceware.org/annobin/annobin.html/Test-pie.html
-              TEST_ANNOCHECK_OPTS: "--skip-pie --skip-gaps"
-            check: true
-          - { 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 } }
-          - { name: clang-9,   env: { default_cc: clang-9 } }
-          - { name: clang-8,   env: { default_cc: clang-8 } }
-          - { name: clang-7,   env: { default_cc: clang-7 } }
-          - { name: clang-6.0, env: { default_cc: clang-6.0 } }
-          - { name: clang-5.0, env: { default_cc: clang-5.0 } }
-          - { name: clang-4.0, env: { default_cc: clang-4.0 } }
-          - { name: clang-3.9, env: { default_cc: clang-3.9 } }
-          - name: 'clang-14 LTO'
-            container: clang-14
-            env:
-              default_cc: 'clang-14 -flto=auto'
-              optflags: '-O2'
-            shared: disable
-            # check: true
+  compile4:
+    name: 'omnibus compilations, #4'
+    runs-on: ubuntu-latest
+    needs: compile-if
+    if: ${{ needs.compile-if.result == 'success' }}
+    timeout-minutes: 60
 
-#         - { 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 }
+    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 }
 
-          # -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: { append_cc: '-std=c99   -Werror=pedantic -pedantic-errors -Wno-strict-prototypes' } }
-#         - { name: c11,   env: { append_cc: '-std=c11   -Werror=pedantic -pedantic-errors -Wno-strict-prototypes' } }
-#         - { name: c17,   env: { append_cc: '-std=c17   -Werror=pedantic -pedantic-errors -Wno-strict-prototypes' } }
-          - { name: c2x,   env: { append_cc: '-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++2a, env: { CXXFLAGS: '-std=c++2a -Werror=pedantic -pedantic-errors -Wno-c++11-long-long' } }
+  compile5:
+    name: 'omnibus compilations, #5'
+    runs-on: ubuntu-latest
+    needs: compile-if
+    if: ${{ needs.compile-if.result == 'success' }}
+    timeout-minutes: 60
 
-          - { name: '-O0', env: { optflags: '-O0 -march=x86-64 -mtune=generic' } }
-#         - { name: '-O3', env: { optflags: '-O3 -march=x86-64 -mtune=generic' }, check: true }
+    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 }
 
-          - { 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-support,  env: { append_configure: '--disable-jit-support' } }
-          - { 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' } }
+  compile6:
+    name: 'omnibus compilations, #6'
+    runs-on: ubuntu-latest
+    needs: compile-if
+    if: ${{ needs.compile-if.result == 'success' }}
+    timeout-minutes: 60
 
-          - { 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' } }
+    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 }
 
-          - { 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' } }
+  compile7:
+    name: 'omnibus compilations, #7'
+    runs-on: ubuntu-latest
+    needs: compile-if
+    if: ${{ needs.compile-if.result == 'success' }}
+    timeout-minutes: 60
 
-#         - { name: RGENGC_CHECK_MODE,              env: { cppflags: '-DRGENGC_CHECK_MODE' } }
-#         - { name: TRANSIENT_HEAP_CHECK_MODE,      env: { cppflags: '-DTRANSIENT_HEAP_CHECK_MODE' } }
-#         - { name: VM_CHECK_MODE,                  env: { cppflags: '-DVM_CHECK_MODE' } }
+    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 }
 
-          - { name: USE_EMBED_CI=0,                 env: { cppflags: '-DUSE_EMBED_CI=0' } }
-          - { name: USE_FLONUM=0,                   env: { cppflags: '-DUSE_FLONUM=0' } }
-#         - { 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_RINCGC=0,                   env: { cppflags: '-DUSE_RINCGC=0' } }
-#         - { name: USE_SYMBOL_GC=0,                env: { cppflags: '-DUSE_SYMBOL_GC=0' } }
-#         - { name: USE_THREAD_CACHE=0,             env: { cppflags: '-DUSE_THREAD_CACHE=0' } }
-#         - { name: USE_TRANSIENT_HEAP=0,           env: { cppflags: '-DUSE_TRANSIENT_HEAP=0' } }
-#         - { name: USE_RUBY_DEBUG_LOG=1,           env: { cppflags: '-DUSE_RUBY_DEBUG_LOG=1' } }
-          - { name: USE_RVARGC=0,                   env: { cppflags: '-DUSE_RVARGC=0' } }
-#         - { name: USE_RVARGC=1,                   env: { cppflags: '-DUSE_RVARGC=1' } }
-#         - { name: USE_DEBUG_COUNTER,              env: { cppflags: '-DUSE_DEBUG_COUNTER=1', RUBY_DEBUG_COUNTER_DISABLE: '1' } }
+  compile8:
+    name: 'omnibus compilations, #8'
+    runs-on: ubuntu-latest
+    needs: compile-if
+    if: ${{ needs.compile-if.result == 'success' }}
+    timeout-minutes: 60
 
-          - { 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' } }
+    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 }
 
-          - { 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' } }
+  compile9:
+    name: 'omnibus compilations, #9'
+    runs-on: ubuntu-latest
+    needs: compile-if
+    if: ${{ needs.compile-if.result == 'success' }}
+    timeout-minutes: 60
 
-#         - { name: CALC_EXACT_MALLOC_SIZE,         env: { cppflags: '-DCALC_EXACT_MALLOC_SIZE' } }
-#         - { name: MALLOC_ALLOCATED_SIZE_CHECK,    env: { cppflags: '-DMALLOC_ALLOCATED_SIZE_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 }
 
-#         - { name: IBF_ISEQ_ENABLE_LOCAL_BUFFER,   env: { cppflags: '-DIBF_ISEQ_ENABLE_LOCAL_BUFFER' } }
+  compileX:
+    name: 'omnibus compilations, #10'
+    runs-on: ubuntu-latest
+    needs: compile-if
+    if: ${{ needs.compile-if.result == 'success' }}
+    timeout-minutes: 60
 
-#         - { 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_OLD_NEWOBJ_CHECK,        env: { cppflags: '-DRGENGC_OLD_NEWOBJ_CHECK' } }
-#         - { name: RGENGC_PROFILE,                 env: { cppflags: '-DRGENGC_PROFILE' } }
+    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 }
 
-#         - { name: VM_DEBUG_BP_CHECK,              env: { cppflags: '-DVM_DEBUG_BP_CHECK' } }
-#         - { name: VM_DEBUG_VERIFY_METHOD_CACHE,   env: { cppflags: '-DVM_DEBUG_VERIFY_METHOD_CACHE' } }
+  compileB:
+    name: 'omnibus compilations, #11'
+    runs-on: ubuntu-latest
+    needs: compile-if
+    if: ${{ needs.compile-if.result == 'success' }}
+    timeout-minutes: 60
 
-          - { name: MJIT_FORCE_ENABLE,              env: { cppflags: '-DMJIT_FORCE_ENABLE' } }
-          - { name: YJIT_FORCE_ENABLE,              env: { cppflags: '-DYJIT_FORCE_ENABLE' } }
+    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 }
 
-    name: ${{ matrix.entry.name }}
+  compileC:
+    name: 'omnibus compilations, #12'
     runs-on: ubuntu-latest
-    container:
-      image: ghcr.io/ruby/ruby-ci-image:${{ matrix.entry.container || matrix.entry.env.default_cc || 'clang-15' }}
-      options: --user root
-    if: ${{ !contains(github.event.head_commit.message, '[DOC]') && !contains(github.event.pull_request.labels.*.name, 'Documentation') }}
-    env: ${{ matrix.entry.env || matrix.env }}
+    needs: compile-if
+    if: ${{ needs.compile-if.result == 'success' }}
+    timeout-minutes: 60
+
     steps:
-      - run: id
-        working-directory:
-      - run: mkdir build
-        working-directory:
-      - name: setenv
-        run: |
-          echo "GNUMAKEFLAGS=-sj$((1 + $(nproc --all)))" >> $GITHUB_ENV
-      - uses: actions/checkout@ac593985615ec2ede58e132d2e21d2b1cbd6127c # v3.3.0
-        with:
-          path: src
-      - uses: actions/cache@627f0f41f6904a5b1efbaed9f96d9eb58e92e920 # v3.2.4
-        with:
-          path: src/.downloaded-cache
-          key: downloaded-cache
-      - run: ./autogen.sh
-        working-directory: src
-      - name: Run configure
-        run: >
-          ../src/configure -C ${default_configure} ${append_configure}
-          --${{
-            matrix.entry.crosshost && 'host' || 'with-gcc'
-          }}=${{
-            matrix.entry.crosshost || '"${default_cc}${append_cc:+ $append_cc}"'
-          }}
-          --${{ matrix.entry.shared || 'enable' }}-shared
-      - run: make extract-extlibs
-      - run: make incs
-      - run: make showflags
-      - run: make
-      - run: make leaked-globals
-      - run: make test
-      - run: make install
-        if: ${{ matrix.entry.check }}
-      - run: make test-tool
-        if: ${{ matrix.entry.check }}
-      - run: make test-all TESTS='-- ruby -ext-'
-        if: ${{ matrix.entry.check }}
-      - run: make test-spec
-        env:
-          CHECK_LEAKS: true
-        if: ${{ matrix.entry.check }}
-      - run: make test-annocheck
-        if: ${{ matrix.entry.check && endsWith(matrix.entry.name, 'annocheck') }}
+      - 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 }
 
-      - uses: ruby/action-slack@b6882ea6ef8f556f9f9af9ec1220d3f1ced74acf # v3.0.0
+  compilemax:
+    name: 'omnibus compilations, result'
+    runs-on: ubuntu-latest
+    if: ${{ always() }}
+    needs:
+      - 'compile1'
+      - 'compile2'
+      - 'compile3'
+      - 'compile4'
+      - 'compile5'
+      - 'compile6'
+      - 'compile7'
+      - 'compile8'
+      - 'compile9'
+      - 'compileX'
+      - 'compileB'
+      - 'compileC'
+    steps:
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with: { sparse-checkout-cone-mode: false, sparse-checkout: /.github, persist-credentials: false }
+      - uses: ./.github/actions/slack
         with:
-          payload: |
-            {
-              "ci": "GitHub Actions",
-              "env": "${{ github.workflow }} / ${{ matrix.entry.name }}",
-              "url": "https://github.com/${{ github.repository }}/actions/runs/${{ github.run_id }}",
-              "commit": "${{ github.sha }}",
-              "branch": "${{ github.ref_name }}"
-            }
-        env:
+          label: 'omnibus'
           SLACK_WEBHOOK_URL: ${{ secrets.SIMPLER_ALERTS_URL }} # ruby-lang slack: ruby/simpler-alerts-bot
-        if: ${{ failure() && github.event_name == 'push' }}
+        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
new file mode 100644
index 0000000000..2e4dc8d7a2
--- /dev/null
+++ b/.github/workflows/dependabot_automerge.yml
@@ -0,0 +1,32 @@
+# from https://github.com/gofiber/swagger/blob/main/.github/workflows/dependabot_automerge.yml
+name: Dependabot auto-merge
+on:
+  pull_request:
+
+permissions:
+  contents: write
+  pull-requests: write
+
+jobs:
+  automerge:
+    runs-on: ubuntu-latest
+    if: github.event.pull_request.user.login == 'dependabot[bot]' && github.repository == 'ruby/ruby'
+    steps:
+      - name: Dependabot metadata
+        uses: dependabot/fetch-metadata@25dd0e34f4fe68f24cc83900b1fe3fe149efef98 # v3.1.0
+        id: metadata
+
+      - name: Wait for status checks
+        uses: lewagon/wait-on-check-action@9312864dfbc9fd208e9c0417843430751c042800 # v1.7.0
+        with:
+          repo-token: ${{ secrets.GITHUB_TOKEN }}
+          ref: ${{ github.event.pull_request.head.sha || github.sha }}
+          check-regexp: 'make \(check, .*\)'
+          wait-interval: 30
+
+      - name: Auto-merge for Dependabot PRs
+        if: ${{ steps.metadata.outputs.update-type == 'version-update:semver-minor' || steps.metadata.outputs.update-type == 'version-update:semver-patch' }}
+        run: gh pr merge --auto --rebase "$PR_URL"
+        env:
+          PR_URL: ${{ github.event.pull_request.html_url }}
+          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 68a0bd404c..4f1807121f 100644
--- a/.github/workflows/macos.yml
+++ b/.github/workflows/macos.yml
@@ -3,17 +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:
 
 concurrency:
   group: ${{ github.workflow }} / ${{ startsWith(github.event_name, 'pull') && github.ref_name || github.sha }}
@@ -26,84 +24,167 @@ jobs:
   make:
     strategy:
       matrix:
-        test_task: ["check"] # "test-bundler-parallel", "test-bundled-gems"
-        os:
-          - macos-11
-          - macos-12
+        include:
+          - test_task: check
+            os: macos-26
+          - test_task: check
+            os: macos-15
+            configure_args: '--with-gcc=gcc-14'
+          - test_task: check
+            os: macos-26
+            configure_args: '--with-jemalloc --with-opt-dir=$(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:
-      GITPULLOPTIONS: --no-tags origin ${{github.ref}}
+      GITPULLOPTIONS: --no-tags origin ${{ github.ref }}
+
     runs-on: ${{ matrix.os }}
-    if: ${{ !contains(github.event.head_commit.message, '[DOC]') && !contains(github.event.pull_request.labels.*.name, 'Documentation') }}
+
+    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: mkdir build
-        working-directory:
-      - name: git config
-        run: |
-          git config --global advice.detachedHead 0
-          git config --global init.defaultBranch garbage
-      - uses: actions/checkout@ac593985615ec2ede58e132d2e21d2b1cbd6127c # v3.3.0
-        with:
-          path: src
-      - uses: actions/cache@627f0f41f6904a5b1efbaed9f96d9eb58e92e920 # v3.2.4
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
         with:
-          path: src/.downloaded-cache
-          key: downloaded-cache
+          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
+          clean: true
+          dummy-files: ${{ matrix.test_task == 'check' }}
+          # Set fetch-depth: 0 so that Launchable can receive commits information.
+          fetch-depth: 10
+
+      - name: make sure that kern.coredump=1
         run: |
-          brew upgrade
-          brew install gmp libffi openssl@1.1 zlib autoconf automake libtool readline bison
-        working-directory: src
-      - name: Set ENV
+          sysctl -n kern.coredump
+          sudo sysctl -w kern.coredump=1
+          sudo chmod -R +rwx /cores/
+
+      - name: Delete unused SDKs
+        # To free up disk space to not run out during the run
         run: |
-          echo "MAKEFLAGS=-j$((1 + $(sysctl -n hw.activecpu)))" >> $GITHUB_ENV
-          echo "PATH="/usr/local/opt/bison/bin:$PATH"" >> $GITHUB_ENV
-          for lib in openssl@1.1 readline; do
-            CONFIGURE_ARGS="${CONFIGURE_ARGS:+$CONFIGURE_ARGS }--with-${lib%@*}-dir=$(brew --prefix $lib)"
-          done
-          echo CONFIGURE_ARGS="${CONFIGURE_ARGS}" >> $GITHUB_ENV
-      - run: ./autogen.sh
-        working-directory: src
+          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
-      - run: make incs
+        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 leaked-globals
-        if: ${{ matrix.test_task == 'check' }}
+
+      - run: make hello
+
+      - name: runirb
+        run: |
+          echo IRB::VERSION | make runirb RUNOPT="-- -f"
+
+      - name: Set test options for skipped tests
+        run: |
+          set -x
+          TESTS="$(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: 40
+          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"
+          RUBY_TESTOPTS: '-q --tty=no'
+          TEST_BUNDLED_GEMS_ALLOW_FAILURES: ''
+          PRECHECK_BUNDLED_GEMS: 'no'
+          LAUNCHABLE_STDOUT: ${{ steps.launchable.outputs.stdout_report_path }}
+          LAUNCHABLE_STDERR: ${{ steps.launchable.outputs.stderr_report_path }}
+
       - name: make skipped tests
         run: |
-          make -s test-all TESTS=`echo "$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 != '' }}
+          GNUMAKEFLAGS: ''
+          RUBY_TESTOPTS: '-v --tty=no'
+          PRECHECK_BUNDLED_GEMS: 'no'
+        if: ${{ matrix.test_task == 'check' && matrix.skipped_tests }}
         continue-on-error: ${{ matrix.continue-on-skipped_tests || false }}
-      - uses: ruby/action-slack@b6882ea6ef8f556f9f9af9ec1220d3f1ced74acf # v3.0.0
+
+      - name: CAPI extensions
+        uses: ./.github/actions/capiext
         with:
-          payload: |
-            {
-              "ci": "GitHub Actions",
-              "env": "${{ matrix.os }} / ${{ matrix.test_task }}${{ matrix.configure }}",
-              "url": "https://github.com/${{ github.repository }}/actions/runs/${{ github.run_id }}",
-              "commit": "${{ github.sha }}",
-              "branch": "${{ github.ref_name }}"
-            }
+          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 }}
           SLACK_WEBHOOK_URL: ${{ secrets.SIMPLER_ALERTS_URL }} # ruby-lang slack: ruby/simpler-alerts-bot
-        if: ${{ failure() && github.event_name == 'push' }}
+        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') }}
 
 defaults:
   run:
diff --git a/.github/workflows/mingw.yml b/.github/workflows/mingw.yml
index e5d1ffb565..9a47e70f8c 100644
--- a/.github/workflows/mingw.yml
+++ b/.github/workflows/mingw.yml
@@ -3,17 +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:
 
 concurrency:
   group: ${{ github.workflow }} / ${{ startsWith(github.event_name, 'pull') && github.ref_name || github.sha }}
@@ -27,145 +30,217 @@ permissions:
 #
 jobs:
   make:
-    runs-on: windows-2022
+    runs-on: windows-${{ 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"
-      CPPFLAGS: "-D_FORTIFY_SOURCE=2 -D__USE_MINGW_ANSI_STDIO=1 -DFD_SETSIZE=2048"
-      LDFLAGS:  "-pipe"
-      GITPULLOPTIONS: --no-tags origin ${{github.ref}}
+      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 }}
+
     strategy:
       matrix:
         include:
           # To mitigate flakiness of MinGW CI, we test only one runtime that newer MSYS2 uses.
-          - msystem: "UCRT64"
-            base_ruby: head
-            test_task: "check"
-            test-all-opts: "--name=!/TestObjSpace#test_reachable_objects_during_iteration/"
+          # Ruby 3.2 is the first Windows Ruby to use OpenSSL 3.x
+          - msystem: 'UCRT64'
+            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: ${{ !contains(github.event.head_commit.message, '[DOC]') && !contains(github.event.pull_request.labels.*.name, 'Documentation') }}
+
+    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/vcpkg'))
+      )}}
+
     steps:
-      - run: mkdir build
-        working-directory:
-      - name: git config
-        run: |
-          git config --global core.autocrlf false
-          git config --global core.eol lf
-          git config --global advice.detachedHead 0
-          git config --global init.defaultBranch garbage
-      - uses: actions/checkout@ac593985615ec2ede58e132d2e21d2b1cbd6127c # v3.3.0
-        with:
-          path: src
-      - uses: actions/cache@627f0f41f6904a5b1efbaed9f96d9eb58e92e920 # v3.2.4
+      - uses: msys2/setup-msys2@e9898307ac31d1a803454791be09ab9973336e1c # v2.31.1
+        id: msys2
         with:
-          path: src/.downloaded-cache
-          key: downloaded-cache
-      - name: Set up Ruby & MSYS2
-        uses: ruby/setup-ruby@ee26e27437bde475b19a6bf8cb73c9fa658876a2 # v1.134.0
-        with:
-          ruby-version: ${{ matrix.base_ruby }}
-      - name: set env
+          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
+            ${{ env.MINGW_PACKAGE_PREFIX }}-libffi
+
+      - name: Set up env
+        id: setup-env
+        working-directory:
         run: |
-          echo "GNUMAKEFLAGS=-j$((2 * NUMBER_OF_PROCESSORS))" >> $GITHUB_ENV
+          $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: 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 bison.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
-          $result
-
-      - name: version check
+      - name: Remove Strawberry Perl pkg-config
+        working-directory:
+        # `pkg-config.bat` included in Strawberry Perl is written in
+        # Perl and doesn't work when another msys2 `perl` precede its
+        # own `perl`.
+        #
+        # ```
+        # Can't find C:\Strawberry\perl\bin\pkg-config.bat on PATH, '.' not in PATH.
+        # ```
         run: |
-          # show version
-          result=true
-          for e in gcc ragel make bison "openssl version"; do
-            case "$e" in *" "*) ;; *) e="$e --version";; esac
-            echo '##['group']'$'\033[93m'$e$'\033[m'
-            $e || result=false
-            echo '##['endgroup']'
-          done
-          $result
-
-      - name: autogen
+          Get-Command pkg-config.bat | % { ren $_.path ($_.path + "~") }
+        shell: pwsh
+
+      - name: Misc system & package info
+        working-directory:
         run: |
-          ./autogen.sh
-        working-directory: src
+          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
-
-      - name: update
-        run: |
-          make incs
-
-      - name: download gems
-        run: |
-          make update-gems
+        shell: sh
+        env:
+          CHOST: ${{ env.MSYS2_ARCH }}-w64-mingw32
 
       - name: make all
         timeout-minutes: 30
-        run: |
-          make
-
-      - run: make leaked-globals
+        run: make -j4
 
       - name: make install
-        run: |
-          make DESTDIR=../install install-nodoc
+        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: 5
-        run: |
-          make test
-        if: ${{matrix.test_task == 'check' || matrix.test_task == 'test'}}
+        timeout-minutes: 30
+        run: make test test-tool
+        env:
+          GNUMAKEFLAGS: ''
+          RUBY_TESTOPTS: '-v --tty=no'
+        if: ${{ matrix.test_task == 'check' || matrix.test_task == 'test' }}
 
       - 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/')}}
+        if: ${{ matrix.test_task == 'check' || matrix.test_task == 'test-all' || StartsWith(matrix.test_task, 'test/') }}
 
       - name: test-spec
         timeout-minutes: 10
         run: |
           make ${{ StartsWith(matrix.test_task, 'spec/') && matrix.test_task || 'test-spec' }}
-        if: ${{matrix.test_task == 'check' || matrix.test_task == 'test-spec' || StartsWith(matrix.test_task, 'spec/')}}
+        if: ${{ matrix.test_task == 'check' || matrix.test_task == 'test-spec' || StartsWith(matrix.test_task, 'spec/') }}
 
-      - uses: ruby/action-slack@b6882ea6ef8f556f9f9af9ec1220d3f1ced74acf # v3.0.0
+      - uses: ./src/.github/actions/slack
         with:
-          payload: |
-            {
-              "ci": "GitHub Actions",
-              "env": "${{ github.workflow }} ${{ matrix.msystem }} / ${{ matrix.test_task }}",
-              "url": "https://github.com/${{ github.repository }}/actions/runs/${{ github.run_id }}",
-              "commit": "${{ github.sha }}",
-              "branch": "${{ github.ref_name }}"
-            }
-        env:
+          label: ${{ matrix.msystem }} / ${{ matrix.test_task }}
           SLACK_WEBHOOK_URL: ${{ secrets.SIMPLER_ALERTS_URL }} # ruby-lang slack: ruby/simpler-alerts-bot
-        if: ${{ failure() && github.event_name == 'push' }}
+        if: ${{ failure() }}
 
 defaults:
   run:
     working-directory: build
-    shell: sh
+    shell: cmd
diff --git a/.github/workflows/mjit-bindgen.yml b/.github/workflows/mjit-bindgen.yml
deleted file mode 100644
index 4528c086ad..0000000000
--- a/.github/workflows/mjit-bindgen.yml
+++ /dev/null
@@ -1,97 +0,0 @@
-name: MJIT bindgen
-on:
-  push:
-    paths-ignore:
-      - 'doc/**'
-      - '**/man'
-      - '**.md'
-      - '**.rdoc'
-      - '**/.document'
-  pull_request:
-    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: mjit-bindgen
-      fail-fast: false
-    runs-on: ubuntu-20.04
-    if: ${{ !contains(github.event.head_commit.message, '[DOC]') && !contains(github.event.pull_request.labels.*.name, 'Documentation') }}
-    steps:
-      - run: mkdir build
-        working-directory:
-      - name: Set ENV
-        run: |
-          echo "GNUMAKEFLAGS=-j$((1 + $(nproc --all)))" >> $GITHUB_ENV
-      - name: Install libraries
-        run: |
-          set -x
-          sudo apt-get update -q || :
-          sudo apt-get install --no-install-recommends -q -y \
-          build-essential \
-          libssl-dev libyaml-dev libreadline6-dev \
-          zlib1g-dev libncurses5-dev libffi-dev \
-          libclang1-10 \
-          bison autoconf
-          sudo apt-get install -q -y pkg-config || :
-      - name: Set up Ruby
-        uses: ruby/setup-ruby@ee26e27437bde475b19a6bf8cb73c9fa658876a2 # v1.134.0
-        with:
-          ruby-version: '3.1'
-      - name: git config
-        run: |
-          git config --global advice.detachedHead 0
-          git config --global init.defaultBranch garbage
-      - uses: actions/checkout@ac593985615ec2ede58e132d2e21d2b1cbd6127c # v3.3.0
-        with:
-          path: src
-      - uses: actions/cache@627f0f41f6904a5b1efbaed9f96d9eb58e92e920 # v3.2.4
-        with:
-          path: src/.downloaded-cache
-          key: downloaded-cache
-      - name: Fixed world writable dirs
-        run: |
-          chmod -v go-w $HOME $HOME/.config
-          sudo chmod -R go-w /usr/share
-          sudo bash -c 'IFS=:; for d in '"$PATH"'; do chmod -v go-w $d; done' || :
-      - run: ./autogen.sh
-        working-directory: src
-      - name: Run configure
-        run: ../src/configure -C --disable-install-doc --prefix=$(pwd)/install --enable-yjit=dev_nodebug
-      - run: make incs
-      - run: make
-      - run: make install
-      - run: make ${{ matrix.task }}
-      - run: git diff --exit-code
-        working-directory: src
-      - uses: ruby/action-slack@b6882ea6ef8f556f9f9af9ec1220d3f1ced74acf # v3.0.0
-        with:
-          payload: |
-            {
-              "ci": "GitHub Actions",
-              "env": "${{ matrix.os }} / ${{ matrix.test_task }}${{ matrix.configure }}",
-              "url": "https://github.com/${{ github.repository }}/actions/runs/${{ github.run_id }}",
-              "commit": "${{ github.sha }}",
-              "branch": "${{ github.ref_name }}"
-            }
-        env:
-          SLACK_WEBHOOK_URL: ${{ secrets.SIMPLER_ALERTS_URL }} # ruby-lang slack: ruby/simpler-alerts-bot
-        if: ${{ failure() && github.event_name == 'push' }}
-
-defaults:
-  run:
-    working-directory: build
diff --git a/.github/workflows/mjit.yml b/.github/workflows/mjit.yml
deleted file mode 100644
index 2dac2b7b6b..0000000000
--- a/.github/workflows/mjit.yml
+++ /dev/null
@@ -1,103 +0,0 @@
-name: MJIT
-on:
-  push:
-    paths-ignore:
-      - 'doc/**'
-      - '**/man'
-      - '**.md'
-      - '**.rdoc'
-      - '**/.document'
-  pull_request:
-    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:
-        test_task: [check] # to make job names consistent
-        mjit_opts: [--mjit-wait]
-      fail-fast: false
-    runs-on: ubuntu-latest
-    if: ${{ !contains(github.event.head_commit.message, '[DOC]') && !contains(github.event.pull_request.labels.*.name, 'Documentation') }}
-    env:
-      TESTOPTS: '-q --tty=no'
-      RUN_OPTS: '--disable-gems ${{ matrix.mjit_opts }} --mjit-debug=-ggdb3'
-      GITPULLOPTIONS: --no-tags origin ${{github.ref}}
-    steps:
-      - run: mkdir build
-        working-directory:
-      - name: Install libraries
-        run: |
-          set -x
-          sudo apt-get update -q || :
-          sudo apt-get install --no-install-recommends -q -y build-essential libssl-dev libyaml-dev libreadline6-dev zlib1g-dev libncurses5-dev libffi-dev bison autoconf ruby
-      - name: git config
-        run: |
-          git config --global advice.detachedHead 0
-          git config --global init.defaultBranch garbage
-      - uses: actions/checkout@ac593985615ec2ede58e132d2e21d2b1cbd6127c # v3.3.0
-        with:
-          path: src
-      - uses: actions/cache@627f0f41f6904a5b1efbaed9f96d9eb58e92e920 # v3.2.4
-        with:
-          path: src/.downloaded-cache
-          key: downloaded-cache
-      - name: Fixed world writable dirs
-        run: |
-          chmod -v go-w $HOME $HOME/.config
-          sudo chmod -R go-w /usr/share
-          sudo bash -c 'IFS=:; for d in '"$PATH"'; do chmod -v go-w $d; done' || :
-      - name: Set ENV
-        run: |
-          echo "GNUMAKEFLAGS=-j$((1 + $(nproc --all)))" >> $GITHUB_ENV
-      - run: ./autogen.sh
-        working-directory: src
-      - name: Run configure
-        run: ../src/configure -C --disable-install-doc cppflags=-DVM_CHECK_MODE
-      - run: make incs
-      - run: make
-      - run: sudo make -s install
-      - name: Run test
-        run: |
-          unset GNUMAKEFLAGS
-          make -s test RUN_OPTS="$RUN_OPTS"
-        timeout-minutes: 60
-      # - name: Run test-all
-      #   run: |
-      #     ulimit -c unlimited
-      #     make -s test-all RUN_OPTS="$RUN_OPTS"
-      #   timeout-minutes: 60
-      - name: Run test-spec
-        run: |
-          unset GNUMAKEFLAGS
-          make -s test-spec RUN_OPTS="$RUN_OPTS"
-        timeout-minutes: 60
-      - uses: ruby/action-slack@b6882ea6ef8f556f9f9af9ec1220d3f1ced74acf # v3.0.0
-        with:
-          payload: |
-            {
-              "ci": "GitHub Actions",
-              "env": "${{ github.workflow }} / ${{ matrix.test_task }} ${{ matrix.mjit_opts }}",
-              "url": "https://github.com/${{ github.repository }}/actions/runs/${{ github.run_id }}",
-              "commit": "${{ github.sha }}",
-              "branch": "${{ github.ref_name }}"
-            }
-        env:
-          SLACK_WEBHOOK_URL: ${{ secrets.SIMPLER_ALERTS_URL }} # ruby-lang slack: ruby/simpler-alerts-bot
-        if: ${{ failure() && github.event_name == 'push' }}
-
-defaults:
-  run:
-    working-directory: build
diff --git a/.github/workflows/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/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 c41bd60736..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
@@ -10,17 +10,19 @@ 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'
-  push:
-    branches: [ "master" ]
+    - cron: '39 3 * * 5'
+  # push:
+  #   branches: [ "master" ]
 
 # Declare default permissions as read only.
 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
@@ -32,20 +34,20 @@ jobs:
 
     steps:
       - name: "Checkout code"
-        uses: actions/checkout@ac593985615ec2ede58e132d2e21d2b1cbd6127c # v3.3.0
+        uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
         with:
           persist-credentials: false
 
       - name: "Run analysis"
-        uses: ossf/scorecard-action@e38b1902ae4f44df626f11ba0734b14fb91f8f86 # v2.1.2
+        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
+        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.
+      # 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@3ebbd71c74ef574dbc558c82f70e52732c8b44fe # v2.1.27
+        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 ed89b5e159..39714b13a4 100644
--- a/.github/workflows/spec_guards.yml
+++ b/.github/workflows/spec_guards.yml
@@ -3,12 +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:
 
 concurrency:
   group: ${{ github.workflow }} / ${{ startsWith(github.event_name, 'pull') && github.ref_name || github.sha }}
@@ -20,38 +23,46 @@ permissions:
 jobs:
   rubyspec:
     name: Rubyspec
-    runs-on: ubuntu-20.04
-    if: ${{ !contains(github.event.head_commit.message, '[DOC]') && !contains(github.event.pull_request.labels.*.name, 'Documentation') }}
+
+    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]')
+      )}}
+
     strategy:
       matrix:
         # Specs from ruby/spec should still run on all supported Ruby versions.
         # This also ensures the needed ruby_version_is guards are there, see spec/README.md.
         ruby:
-          - ruby-2.7
-          - ruby-3.1
-          - ruby-3.2
+          - ruby-3.3
+          - ruby-3.4
+          - ruby-4.0
+      fail-fast: false
 
     steps:
-      - uses: actions/checkout@ac593985615ec2ede58e132d2e21d2b1cbd6127c # v3.3.0
-      - uses: ruby/setup-ruby@ee26e27437bde475b19a6bf8cb73c9fa658876a2 # v1.134.0
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with:
+          persist-credentials: false
+
+      - uses: ruby/setup-ruby@afeafc3d1ab54a631816aba4c914a0081c12ff2f # v1.310.0
         with:
           ruby-version: ${{ matrix.ruby }}
           bundler: none
+
       - run: gem install webrick
+
       - run: ruby ../mspec/bin/mspec
         working-directory: spec/ruby
         env:
           CHECK_LEAKS: true
-      - uses: ruby/action-slack@b6882ea6ef8f556f9f9af9ec1220d3f1ced74acf # v3.0.0
+
+      - uses: ./.github/actions/slack
         with:
-          payload: |
-            {
-              "ci": "GitHub Actions",
-              "env": "${{ github.workflow }} / rubyspec @ ${{ matrix.ruby }}",
-              "url": "https://github.com/${{ github.repository }}/actions/runs/${{ github.run_id }}",
-              "commit": "${{ github.sha }}",
-              "branch": "${{ github.ref_name }}"
-            }
-        env:
+          label: ${{ matrix.ruby }}
           SLACK_WEBHOOK_URL: ${{ secrets.SIMPLER_ALERTS_URL }} # ruby-lang slack: ruby/simpler-alerts-bot
-        if: ${{ failure() && github.event_name == 'push' }}
+        if: ${{ failure() }}
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 045a952e20..c887ae3811 100644
--- a/.github/workflows/ubuntu.yml
+++ b/.github/workflows/ubuntu.yml
@@ -3,17 +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:
 
 concurrency:
   group: ${{ github.workflow }} / ${{ startsWith(github.event_name, 'pull') && github.ref_name || github.sha }}
@@ -26,111 +24,251 @@ jobs:
   make:
     strategy:
       matrix:
-        test_task: [check]
-        arch: ['']
-        configure: ['cppflags=-DVM_CHECK_MODE']
-        # specifying everything else 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-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:
-      GITPULLOPTIONS: --no-tags origin ${{github.ref}}
+
+    env: &make-env
+      GITPULLOPTIONS: --no-tags origin ${{ github.ref }}
       RUBY_DEBUG: ci
-      SETARCH: ${{ matrix.arch && format('setarch {0}', matrix.arch) }}
-    runs-on: ubuntu-20.04
-    if: ${{ !contains(github.event.head_commit.message, '[DOC]') && !contains(github.event.pull_request.labels.*.name, 'Documentation') }}
-    steps:
-      - run: mkdir build
-        working-directory:
-      - name: Set ENV
-        run: |
-          echo "GNUMAKEFLAGS=-j$((1 + $(nproc --all)))" >> $GITHUB_ENV
-      - name: Install libraries
-        env:
-          arch: ${{matrix.arch}}
-        run: |
-          set -x
-          arch=${arch:+:${arch/i[3-6]86/i386}}
-          ${arch:+sudo dpkg --add-architecture ${arch#:}}
-          sudo apt-get update -q || :
-          sudo apt-get install --no-install-recommends -q -y \
-          ${arch:+cross}build-essential${arch/:/-} \
-          libssl-dev${arch} libyaml-dev${arch} libreadline6-dev${arch} \
-          zlib1g-dev${arch} libncurses5-dev${arch} libffi-dev${arch} \
-          bison autoconf ruby
-          sudo apt-get install -q -y pkg-config${arch} || :
-      - name: git config
-        run: |
-          git config --global advice.detachedHead 0
-          git config --global init.defaultBranch garbage
-      - uses: actions/checkout@ac593985615ec2ede58e132d2e21d2b1cbd6127c # v3.3.0
+
+    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.pull_request.user.login == 'dependabot[bot]')
+      )}}
+
+    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:
-          path: src
-      - uses: actions/cache@627f0f41f6904a5b1efbaed9f96d9eb58e92e920 # v3.2.4
+          arch: ${{ matrix.arch }}
+
+      - uses: ruby/setup-ruby@afeafc3d1ab54a631816aba4c914a0081c12ff2f # v1.310.0
         with:
-          path: src/.downloaded-cache
-          key: downloaded-cache
-      - name: Fixed world writable dirs
-        run: |
-          chmod -v go-w $HOME $HOME/.config
-          sudo chmod -R go-w /usr/share
-          sudo bash -c 'IFS=:; for d in '"$PATH"'; do chmod -v go-w $d; done' || :
-      - run: ./autogen.sh
-        working-directory: src
+          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}}
+          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 incs
+
       - run: $SETARCH make prepare-gems
         if: ${{ matrix.test_task == 'test-bundled-gems' }}
+
       - run: $SETARCH make
-      - run: $SETARCH make leaked-globals
-        if: ${{ matrix.test_task == 'check' }}
-      - name: Create dummy files in build dir
+
+      - run: $SETARCH make hello
+
+      - name: runirb
         run: |
-          $SETARCH ./miniruby -e '(("a".."z").to_a+("A".."Z").to_a+("0".."9").to_a+%w[foo bar test zzz]).each{|basename|File.write("#{basename}.rb", "raise %(do not load #{basename}.rb)")}'
-        if: ${{ matrix.test_task == 'check' }}
+          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| |$$/ -n!/|g;s|^|-n!/|;s|$|$$/|'`}
-        timeout-minutes: 40
+          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.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"
+          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: |
-          $SETARCH make -s test-all TESTS=`echo "$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 != '' }}
+          GNUMAKEFLAGS: ''
+          RUBY_TESTOPTS: '-v --tty=no'
+        if: ${{ matrix.test_task == 'check' && matrix.skipped_tests }}
         continue-on-error: ${{ matrix.continue-on-skipped_tests || false }}
-      - uses: ruby/action-slack@b6882ea6ef8f556f9f9af9ec1220d3f1ced74acf # v3.0.0
+
+      - name: test-pc
+        run: |
+          DESTDIR=${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:
-          payload: |
-            {
-              "ci": "GitHub Actions",
-              "env": "${{ github.workflow }} / ${{ matrix.test_task }} ${{ matrix.configure }}${{ matrix.arch }}",
-              "url": "https://github.com/${{ github.repository }}/actions/runs/${{ github.run_id }}",
-              "commit": "${{ github.sha }}",
-              "branch": "${{ github.ref_name }}"
-            }
+          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: ruby-bench ${{ matrix.bench_opts }} ${{ matrix.ruby_opts }}
           SLACK_WEBHOOK_URL: ${{ secrets.SIMPLER_ALERTS_URL }} # ruby-lang slack: ruby/simpler-alerts-bot
-        if: ${{ failure() && github.event_name == 'push' }}
+        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') }}
 
 defaults:
   run:
diff --git a/.github/workflows/wasm.yml b/.github/workflows/wasm.yml
index 2f69e001b6..f0263de5ef 100644
--- a/.github/workflows/wasm.yml
+++ b/.github/workflows/wasm.yml
@@ -3,23 +3,26 @@ on:
   push:
     paths-ignore:
       - 'doc/**'
-      - '**/man'
+      - '**/man/*'
       - '**.md'
       - '**.rdoc'
       - '**/.document'
+      - '.*.yml'
   pull_request:
     paths-ignore:
       - 'doc/**'
-      - '**/man'
+      - '**/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:  # added using https://github.com/step-security/secure-workflows
+permissions: # added using https://github.com/step-security/secure-workflows
   contents: read
 
 jobs:
@@ -28,40 +31,58 @@ jobs:
       matrix:
         entry:
 #         # wasmtime can't compile non-optimized Asyncified binary due to locals explosion
-#         - { name: O0-debuginfo, optflags: "-O0", debugflags: "-g", wasmoptflags: "-O1" }
-#         - { name: O1,           optflags: "-O1", debugflags: ""  , wasmoptflags: "-O1" }
-          - { name: O2,           optflags: "-O2", debugflags: ""  , wasmoptflags: "-O2" }
-#         - { name: O3,           optflags: "-O3", debugflags: ""  , wasmoptflags: "-O3" }
+#         - { name: O0-debuginfo, optflags: '-O0', debugflags: '-g', wasmoptflags: '-O1' }
+#         - { name: O1,           optflags: '-O1', debugflags: ''  , wasmoptflags: '-O1' }
+          - { name: O2, optflags: '-O2', debugflags: '', wasmoptflags: '-O2' }
+#         - { name: O3,           optflags: '-O3', debugflags: ''  , wasmoptflags: '-O3' }
 #         # -O4 is equivalent to -O3 in clang, but it's different in wasm-opt
-#         - { name: O4,           optflags: "-O3", debugflags: ""  , wasmoptflags: "-O4" }
-#         - { name: Oz,           optflags: "-Oz", debugflags: ""  , wasmoptflags: "-Oz" }
+#         - { name: O4,           optflags: '-O3', debugflags: ''  , wasmoptflags: '-O4' }
+#         - { name: Oz,           optflags: '-Oz', debugflags: ''  , wasmoptflags: '-Oz' }
       fail-fast: false
+
     env:
       RUBY_TESTOPTS: '-q --tty=no'
-      GITPULLOPTIONS: --no-tags origin ${{github.ref}}
-      WASI_SDK_VERSION_MAJOR: 14
+      GITPULLOPTIONS: --no-tags origin ${{ github.ref }}
+      WASI_SDK_VERSION_MAJOR: 25
       WASI_SDK_VERSION_MINOR: 0
-      BINARYEN_VERSION: 109
-      WASMTIME_VERSION: v0.33.0
-    runs-on: ubuntu-20.04
-    if: ${{ !contains(github.event.head_commit.message, '[DOC]') && !contains(github.event.pull_request.labels.*.name, 'Documentation') }}
+      BINARYEN_VERSION: 113
+      WASMTIME_VERSION: v15.0.0
+
+    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:
-      - run: mkdir build
-        working-directory:
-      - name: git config
-        run: |
-          git config --global advice.detachedHead 0
-          git config --global init.defaultBranch garbage
-      - uses: actions/checkout@ac593985615ec2ede58e132d2e21d2b1cbd6127c # v3.3.0
+      - 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:
-          path: src
+          ruby-version: '3.1'
+          bundler: none
+
+      - uses: ./.github/actions/setup/directories
+        with:
+          srcdir: src
+          builddir: build
+          makeup: true
+
       - name: Install libraries
         run: |
           set -ex
           sudo apt-get update -q || :
-          sudo apt-get install --no-install-recommends -q -y ruby bison make autoconf git wget
+          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"
@@ -78,49 +99,96 @@ jobs:
           wget -O - "$binaryen_url" | tar xfz -
           sudo ln -fs "$PWD/binaryen-version_${BINARYEN_VERSION}/bin/wasm-opt" /usr/local/bin/wasm-opt
         working-directory: src
+
       - name: Set ENV
         run: |
-          echo "MAKEFLAGS=-j$((1 + $(sysctl -n hw.activecpu)))" >> $GITHUB_ENV
           echo "WASI_SDK_PATH=/opt/wasi-sdk" >> $GITHUB_ENV
-      - run: ./autogen.sh
+
+      - uses: ./.github/actions/setup/baseruby
+        id: baseruby
+        with:
+          srcdir: src
+
+      - name: Download config.guess with wasi version
+        run: |
+          rm tool/config.guess tool/config.sub
+          ruby tool/downloader.rb -d tool -e gnu config.guess config.sub
         working-directory: src
+
       - name: Run configure
-        run: |
-          ../src/configure \
-            --host wasm32-unknown-wasi \
-            --with-static-linked-ext \
-            LDFLAGS=" \
-              -Xlinker --stack-first \
-              -Xlinker -z -Xlinker stack-size=16777216 \
-            " \
-            optflags="${{ matrix.entry.optflags }}" \
-            debugflags="${{ matrix.entry.debugflags }}" \
-            wasmoptflags="${{ matrix.entry.wasmoptflags }} ${{ matrix.entry.debugflags }}"
+        run: >-
+          ../src/configure
+          --host wasm32-unknown-wasi
+          --with-baseruby="${{ 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" >> $GITHUB_STEP_SUMMARY
+
       - name: Run basictest
         run: wasmtime run ./../build/miniruby --mapdir /::./ -- basictest/test.rb
         working-directory: src
+
       - name: Run bootstraptest (no thread)
         run: |
           NO_THREAD_TESTS="$(grep -L Thread -R ./bootstraptest | awk -F/ '{ print $NF }' | uniq | sed -n 's/test_\(.*\).rb/\1/p' | paste -s -d, -)"
           ruby ./bootstraptest/runner.rb --ruby="$(which wasmtime) run $PWD/../build/ruby --mapdir /::./ -- " --verbose "--sets=$NO_THREAD_TESTS"
         working-directory: src
 
-      - uses: ruby/action-slack@b6882ea6ef8f556f9f9af9ec1220d3f1ced74acf # v3.0.0
+      - uses: ./.github/actions/slack
         with:
-          payload: |
-            {
-              "ci": "GitHub Actions",
-              "env": "${{ github.workflow }} / ${{ matrix.name }}",
-              "url": "https://github.com/${{ github.repository }}/actions/runs/${{ github.run_id }}",
-              "commit": "${{ github.sha }}",
-              "branch": "${{ github.ref_name }}"
-            }
-        env:
+          label: ${{ matrix.entry.name }}
           SLACK_WEBHOOK_URL: ${{ secrets.SIMPLER_ALERTS_URL }} # ruby-lang slack: ruby/simpler-alerts-bot
-        if: ${{ failure() && github.event_name == 'push' }}
+        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:
diff --git a/.github/workflows/windows.yml b/.github/workflows/windows.yml
index 195786be1a..03e75ad445 100644
--- a/.github/workflows/windows.yml
+++ b/.github/workflows/windows.yml
@@ -3,17 +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:
 
 concurrency:
   group: ${{ github.workflow }} / ${{ startsWith(github.event_name, 'pull') && github.ref_name || github.sha }}
@@ -27,131 +25,191 @@ jobs:
     strategy:
       matrix:
         include:
-          - vs: 2019
-          - vs: 2022
+          - os: 2022
+            test_task: check
+          - os: 2022
+            test_task: test-bundled-gems
+          - os: 2025-vs2026
+            test_task: check
+          - os: 2025-vs2026
+            test_task: test-bundled-gems
+          - os: 11-arm
+            test_task: 'btest test-basic test-tool' # check and test-spec are broken yet.
+            target: arm64
       fail-fast: false
-    runs-on: windows-${{ matrix.vs < 2022 && '2019' || matrix.vs }}
-    if: ${{ !contains(github.event.head_commit.message, '[DOC]') && !contains(github.event.pull_request.labels.*.name, 'Documentation') }}
-    name: VisualStudio ${{ matrix.vs }}
+
+    runs-on: windows-${{ 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.pull_request.user.login == 'dependabot[bot]' && !startsWith(github.head_ref, 'dependabot/vcpkg'))
+      )}}
+
+    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.vs < 2022 && '2019' || matrix.vs }}
+      GITPULLOPTIONS: --no-tags origin ${{ github.ref }}
+      VCPKG_DEFAULT_TRIPLET: ${{ matrix.target || 'x64' }}-windows
+
     steps:
       - run: md build
         working-directory:
-      - uses: msys2/setup-msys2@d40200dc2db4c351366b048a9565ad82919e1c24 # v2
-        id: setup-msys2
-        with:
-          update: true
-          install: >-
-            patch
-        if: ${{ env.OS_VER != 'windows-2019' }}
-      - name: patch path
-        shell: msys2 {0}
-        run: echo PATCH=$(cygpath -wa $(command -v patch)) >> $GITHUB_ENV
-        if: ${{ steps.setup-msys2.outcome == 'success' }}
-      - uses: actions/cache@627f0f41f6904a5b1efbaed9f96d9eb58e92e920 # v3.2.4
+
+      - uses: ruby/setup-ruby@afeafc3d1ab54a631816aba4c914a0081c12ff2f # v1.310.0
         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-
-      - uses: actions/cache@627f0f41f6904a5b1efbaed9f96d9eb58e92e920 # v3.2.4
+          # 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/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
         with:
-          path: C:\vcpkg\installed
-          key: ${{ runner.os }}-vcpkg-installed-${{ matrix.os }}-${{ github.sha }}
-          restore-keys: |
-            ${{ runner.os }}-vcpkg-installed-${{ matrix.os }}-
-            ${{ runner.os }}-vcpkg-installed-
-      - name: Install libraries with vcpkg
-        run: |
-          vcpkg --triplet x64-windows install libffi libyaml openssl readline zlib
-      - uses: actions/cache@627f0f41f6904a5b1efbaed9f96d9eb58e92e920 # v3.2.4
+          persist-credentials: false
+          sparse-checkout-cone-mode: false
+          sparse-checkout: /.github
+
+      - uses: ./.github/actions/setup/directories
         with:
-          path: C:\Users\runneradmin\AppData\Local\Temp\chocolatey
-          key: ${{ runner.os }}-chocolatey-${{ env.OS_VER }}-${{ github.sha }}
-          restore-keys: |
-            ${{ runner.os }}-chocolatey-${{ env.OS_VER }}-
-            ${{ runner.os }}-chocolatey-
-      - name: Install libraries with chocolatey
+          srcdir: src
+          builddir: build
+          make-command: nmake
+          clean: true
+
+      - name: Install tools with scoop
         run: |
-          # Using Choco-Install for retries, but it doesn't detect failures properly
-          # if you pass multiple package names in a single command.
-          Choco-Install -PackageName winflexbison3
+          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" >> $Env:GITHUB_PATH
+          scoop install vcpkg
         shell: pwsh
-      - name: git config
-        run: |
-          git config --global core.autocrlf false
-          git config --global core.eol lf
-          git config --global advice.detachedHead 0
-          git config --global init.defaultBranch garbage
-      - uses: actions/checkout@ac593985615ec2ede58e132d2e21d2b1cbd6127c # v3.3.0
+
+      - name: Restore vcpkg artifact
+        id: restore-vcpkg
+        uses: actions/cache/restore@27d5ce7f107fe9357f9df03efb73ab90386fccae # v5.0.5
         with:
-          path: src
-      - uses: actions/cache@627f0f41f6904a5b1efbaed9f96d9eb58e92e920 # v3.2.4
+          path: src\vcpkg_installed
+          key: windows-${{ matrix.os }}-vcpkg-${{ hashFiles('src/vcpkg.json') }}
+
+      - name: Install libraries with vcpkg
+        id: build-vcpkg
+        run: |
+          git -C "%VCPKG_INSTALLATION_ROOT%" pull --quiet
+          vcpkg install
+        working-directory: src
+        if: ${{ ! steps.restore-vcpkg.outputs.cache-hit }}
+
+      - name: Save vcpkg artifact
+        uses: actions/cache/save@27d5ce7f107fe9357f9df03efb73ab90386fccae # v5.0.5
         with:
-          path: src/.downloaded-cache
-          key: downloaded-cache
+          path: src\vcpkg_installed
+          key: windows-${{ 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=${{ matrix.vcvars }}
-          if not "%VCVARS%" == "" goto :vcset
-            set VCVARS="C:\Program Files (x86)\Microsoft Visual Studio\%VS%\Enterprise\VC\Auxiliary\Build\vcvars64.bat"
-            if not exist %VCVARS% set VCVARS="C:\Program Files\Microsoft Visual Studio\%VS%\Enterprise\VC\Auxiliary\Build\vcvars64.bat"
-          :vcset
-          set | C:\msys64\usr\bin\sort > old.env
-          call %VCVARS%
-          set TMP=%USERPROFILE%\AppData\Local\Temp
-          set TEMP=%USERPROFILE%\AppData\Local\Temp
+          set > old.env
+          call ..\src\win32\vssetup.cmd ^
+            -arch=${{ matrix.target || 'amd64' }} ^
+            ${{ matrix.vcvars && '-vcvars_ver=' || '' }}${{ matrix.vcvars }}
+          nmake -f nul
+          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 $env:GITHUB_ENV
+
+      - name: baseruby version
+        run: ruby -v
+
       - name: compiler version
         run: cl
-      - name: link libraries
-        run: |
-          for %%I in (C:\vcpkg\installed\x64-windows\bin\*.dll) do (
-            if not %%~nI == readline mklink %%~nxI %%I
-          )
-          for %%I in (libcrypto-1_1-x64 libssl-1_1-x64) do (
-            ren c:\Windows\System32\%%I.dll %%I.dll_
-          )
+
+      - name: volume info
+        run: Get-Volume
+        shell: pwsh
+
+      # TODO: We should use `../src` instead of `D:/a/ruby/ruby/src`
       - name: Configure
         run: >-
           ../src/win32/configure.bat --disable-install-doc
-          --with-opt-dir=C:/vcpkg/installed/x64-windows
+          --with-opt-dir=%RUBY_OPT_DIR%
+          --with-gmp
+
+      - run: nmake prepare-vcpkg
+
       - run: nmake incs
+
       - run: nmake extract-extlibs
+
+      # On all other platforms, test-spec depending on extract-gems (in common.mk) is enough.
+      # But not for this Visual Studio workflow. So here we extract gems before building.
+      - run: nmake extract-gems
+
+      # windows-11-arm runner cannot run `ruby tool/file2lastrev.rb --revision.h --output=revision.h`
+      - name: make revision.h
+        run: |
+          win32\lastrev.bat | win32\ifchange.bat --timestamp=.revision.time revision.h -
+          type revision.h
+        working-directory: src
+
       - run: nmake
-        env:
-          YACC: win_bison
-      - run: nmake test
-        timeout-minutes: 5
-      - run: nmake test-spec
-        timeout-minutes: 10
-      - run: nmake test-all
-        env:
-          RUBY_TESTOPTS: -j${{env.TEST_JOBS}} --job-status=normal
-        timeout-minutes: 60
-      - uses: ruby/action-slack@b6882ea6ef8f556f9f9af9ec1220d3f1ced74acf # v3.0.0
+
+      - name: Set up Launchable
+        uses: ./.github/actions/launchable/setup
         with:
-          payload: |
-            {
-              "ci": "GitHub Actions",
-              "env": "VS${{ matrix.vs }} / ${{ matrix.test_task || 'check' }}",
-              "url": "https://github.com/${{ github.repository }}/actions/runs/${{ github.run_id }}",
-              "commit": "${{ github.sha }}",
-              "branch": "${{ github.ref_name }}"
-            }
+          os: windows-${{ 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 }}
+        timeout-minutes: 70
+
+      - uses: ./.github/actions/slack
+        with:
+          label: Windows ${{ matrix.os }} / ${{ matrix.test_task || 'check' }}
           SLACK_WEBHOOK_URL: ${{ secrets.SIMPLER_ALERTS_URL }} # ruby-lang slack: ruby/simpler-alerts-bot
-        if: ${{ failure() && github.event_name == 'push' }}
+        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:
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
new file mode 100644
index 0000000000..e11de6bc51
--- /dev/null
+++ b/.github/workflows/yjit-macos.yml
@@ -0,0 +1,201 @@
+name: YJIT 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:
+  cargo:
+    name: cargo test
+
+    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
+
+      - run: RUST_BACKTRACE=1 cargo test
+        working-directory: yjit
+
+      # Also compile and test with all features enabled
+      - run: RUST_BACKTRACE=1 cargo test --all-features
+        working-directory: yjit
+
+      # Check that we can build in release mode too
+      - run: cargo build --release
+        working-directory: yjit
+
+  make:
+    strategy:
+      matrix:
+        include:
+          - test_task: 'check'
+            configure: '--enable-yjit'
+            yjit_opts: '--yjit'
+          - test_task: 'check'
+            configure: '--enable-yjit=dev'
+            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-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: Run configure
+        run: ../src/configure -C --disable-install-doc ${{ matrix.configure }}
+
+      - run: make prepare-gems
+        if: ${{ matrix.test_task == 'test-bundled-gems' }}
+
+      - run: make
+
+      - 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 ${{ matrix.test_task }}
+        run: |
+          test -n "${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'
+          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: ${{ matrix.continue-on-test_task || false }}
+
+      - name: make skipped tests
+        run: |
+          make -s test-all TESTS="${TESTS//-n!\//-n/}"
+        env:
+          GNUMAKEFLAGS: ''
+          RUBY_TESTOPTS: '-v --tty=no'
+          PRECHECK_BUNDLED_GEMS: 'no'
+        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 }}
+          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:
+      - name: ${{ github.workflow }} jobs have failed
+        run: exit 1
+        working-directory:
+        if: ${{ contains(needs.*.result, 'failure') || contains(needs.*.result, 'cancelled') }}
+
+defaults:
+  run:
+    working-directory: build
diff --git a/.github/workflows/yjit-ubuntu.yml b/.github/workflows/yjit-ubuntu.yml
index a1e0b67a47..ab816940f4 100644
--- a/.github/workflows/yjit-ubuntu.yml
+++ b/.github/workflows/yjit-ubuntu.yml
@@ -3,17 +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:
 
 concurrency:
   group: ${{ github.workflow }} / ${{ startsWith(github.event_name, 'pull') && github.ref_name || github.sha }}
@@ -24,147 +22,223 @@ permissions:
 
 jobs:
   cargo:
-    name: Rust cargo test
+    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.pull_request.user.login == 'dependabot[bot]' && !startsWith(github.head_ref, 'dependabot/cargo'))
+      )}}
+
     steps:
-      - uses: actions/checkout@ac593985615ec2ede58e132d2e21d2b1cbd6127c # v3.3.0
+      - 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
       #- run: cargo test --offline
+
       - run: RUST_BACKTRACE=1 cargo test
         working-directory: yjit
+
       # Also compile and test with all features enabled
       - run: RUST_BACKTRACE=1 cargo test --all-features
         working-directory: yjit
+
       # Check that we can build in release mode too
       - run: cargo build --release
         working-directory: yjit
+
   lint:
-    name: Rust lint
+    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.pull_request.user.login == 'dependabot[bot]' && !startsWith(github.head_ref, 'dependabot/cargo'))
+      )}}
+
     steps:
-      - uses: actions/checkout@ac593985615ec2ede58e132d2e21d2b1cbd6127c # v3.3.0
+      - 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
         working-directory: yjit
+
   make:
     strategy:
       fail-fast: false
       matrix:
         include:
-          - test_task: "yjit-bindgen"
-            hint: "To fix: use patch in logs"
-            configure: "--with-gcc=clang-12 --enable-yjit=dev"
+          - test_task: 'yjit-bindgen'
+            hint: 'To fix: use patch in logs'
+            # 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"
+          - test_task: 'check'
             # YJIT should be automatically built in release mode on x86-64 Linux with rustc present
             #configure: "--enable-yjit RUSTC='rustc +1.58.0'"
             configure: "RUSTC='rustc +1.58.0'"
-            rust_version: "1.58.0"
+            rust_version: '1.58.0'
 
-          - test_task: "check"
-            configure: "--enable-yjit=dev"
+          - test_task: 'check'
+            configure: '--enable-yjit=dev'
 
-          - test_task: "check"
-            configure: "--enable-yjit=dev"
-            yjit_opts: "--yjit-call-threshold=1 --yjit-verify-ctx"
+          - test_task: 'check'
+            configure: '--enable-yjit=dev'
+            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-all TESTS=--repeat-count=2"
-            configure: "--enable-yjit=dev"
+          - test_task: 'test-bundled-gems'
+            configure: '--enable-yjit=dev'
 
-          - 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}}
+      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
-    if: ${{ !contains(github.event.head_commit.message, '[DOC]') && !contains(github.event.pull_request.labels.*.name, 'Documentation') }}
+
+    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:
-      - run: mkdir build
-        working-directory:
-      - name: Install libraries
-        run: |
-          set -x
-          sudo apt-get update -q || :
-          sudo apt-get install --no-install-recommends -q -y build-essential libssl-dev libyaml-dev libreadline6-dev zlib1g-dev libncurses5-dev libffi-dev bison autoconf ruby
+      - 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: git config
-        run: |
-          git config --global advice.detachedHead 0
-          git config --global init.defaultBranch garbage
-      - uses: actions/checkout@ac593985615ec2ede58e132d2e21d2b1cbd6127c # v3.3.0
-        with:
-          path: src
-      - uses: actions/cache@627f0f41f6904a5b1efbaed9f96d9eb58e92e920 # v3.2.4
-        with:
-          path: src/.downloaded-cache
-          key: downloaded-cache
-      - name: Fixed world writable dirs
-        run: |
-          chmod -v go-w $HOME $HOME/.config
-          sudo chmod -R go-w /usr/share
-          sudo bash -c 'IFS=:; for d in '"$PATH"'; do chmod -v go-w $d; done' || :
-      - name: Set ENV
-        run: |
-          echo "GNUMAKEFLAGS=-j$((1 + $(nproc --all)))" >> $GITHUB_ENV
-      - run: ./autogen.sh
-        working-directory: src
+
+      - name: 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 }}
+
       - run: make incs
+
       - run: make prepare-gems
         if: ${{ matrix.test_task == 'test-bundled-gems' }}
-      - run: make -j
-      - run: make leaked-globals
-        if: ${{ matrix.test_task == 'check' }}
-      - name: Create dummy files in build dir
+
+      - run: make
+
+      - 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: |
-          ./miniruby -e '(("a".."z").to_a+("A".."Z").to_a+("0".."9").to_a+%w[foo bar test zzz]).each{|basename|File.write("#{basename}.rb", "raise %(do not load #{basename}.rb)")}'
-        if: ${{ matrix.test_task == 'check' }}
-      - name: Enable YJIT through ENV
-        run: echo "RUBY_YJIT_ENABLE=1" >> $GITHUB_ENV
+          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" YJIT_BENCH_OPTS="$YJIT_BENCH_OPTS"
-        timeout-minutes: 60
-        env:
-          RUBY_TESTOPTS: "-q --tty=no"
-          TEST_BUNDLED_GEMS_ALLOW_FAILURES: ""
-          PRECHECK_BUNDLED_GEMS: "no"
-        continue-on-error: ${{ matrix.test_task == 'yjit-bench' }}
-      - name: Show ${{ github.event.pull_request.base.ref }} GitHub URL for yjit-bench comparison
-        run: echo "https://github.com/${BASE_REPO}/commit/${BASE_SHA}"
+        run: |
+          test -n "${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:
-          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') }}
-      - uses: ruby/action-slack@b6882ea6ef8f556f9f9af9ec1220d3f1ced74acf # v3.0.0
+          RUBY_TESTOPTS: '-q --tty=no'
+          TEST_BUNDLED_GEMS_ALLOW_FAILURES: ''
+          PRECHECK_BUNDLED_GEMS: 'no'
+          SYNTAX_SUGGEST_TIMEOUT: '5'
+          YJIT_BINDGEN_DIFF_OPTS: '--exit-code'
+          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: Dump crash logs
+        if: ${{ failure() }}
+        continue-on-error: true
+        run: |
+          tail --verbose --lines=+1 rb_crash_*.txt
+          exit 1
+
+      - uses: ./.github/actions/slack
         with:
-          payload: |
-            {
-              "ci": "GitHub Actions",
-              "env": "${{ github.workflow }} / ${{ matrix.test_task }} ${{ matrix.configure }}",
-              "url": "https://github.com/${{ github.repository }}/actions/runs/${{ github.run_id }}",
-              "commit": "${{ github.sha }}",
-              "branch": "${{ github.ref_name }}"
-            }
-        env:
+          label: ${{ matrix.test_task }} ${{ matrix.configure }}
           SLACK_WEBHOOK_URL: ${{ secrets.SIMPLER_ALERTS_URL }} # ruby-lang slack: ruby/simpler-alerts-bot
-        if: ${{ failure() && github.event_name == 'push' }}
+        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') }}
 
 defaults:
   run:
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 ecac178a2c..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
@@ -205,8 +208,10 @@ lcov*.info
 
 # /ext/ripper/
 /ext/ripper/eventids1.c
+/ext/ripper/eventids1.h
 /ext/ripper/.eventids2-check
 /ext/ripper/eventids2table.c
+/ext/ripper/ripper_init.c
 /ext/ripper/ripper.*
 /ext/ripper/ids1
 /ext/ripper/ids2
@@ -228,7 +233,7 @@ lcov*.info
 # /misc/
 /misc/**/__pycache__
 
-# /spec/bundler
+# for `make test-bundler`
 /.rspec_status
 
 # /tool/
@@ -238,15 +243,49 @@ lcov*.info
 # /win32/
 /win32/*.ico
 
-# MJIT
-/include/ruby-*/*/rb_mjit_min_header-*.h
-/lib/ruby_vm/mjit/instruction.rb
-/mjit_config.h
-/rb_mjit_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 665feba914..0000000000
--- a/.travis.yml
+++ /dev/null
@@ -1,235 +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 $travis_apt_get_options install
-        ccache
-        gcc-10
-        g++-10
-        libffi-dev
-        libncurses-dev
-        libncursesw5-dev
-        libreadline-dev
-        libssl-dev
-        libyaml-dev
-        openssl
-        zlib1g-dev
-
-  # --------
-
-  - &arm64-linux
-    name: arm64-linux
-    arch: arm64
-    <<: *gcc-10
-
-  - &ppc64le-linux
-    name: ppc64le-linux
-    arch: ppc64le
-    <<: *gcc-10
-
-  - &s390x-linux
-    name: s390x-linux
-    arch: s390x
-    <<: *gcc-10
-
-  - &arm32-linux
-    name: arm32-linux
-    arch: arm64
-    # https://packages.ubuntu.com/focal/crossbuild-essential-armhf
-    compiler: arm-linux-gnueabihf-gcc
-    env:
-      - SETARCH='setarch linux32 --verbose --32bit'
-      # The "TestReadline#test_interrupt_in_other_thread" started failing on arm32
-      # from https://www.travis-ci.com/github/ruby/ruby/jobs/529005145
-      - TEST_ALL_SKIPPED_TESTS=test_interrupt_in_other_thread
-    before_install:
-      - sudo dpkg --add-architecture armhf
-      - tool/travis_retry.sh sudo bash -c "rm -rf '${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 $JOBS srcs
-  - rm -f config.status Makefile rbconfig.rb .rbconfig.time
-  - |-
-    if [ -d ~/config_2nd ]; then
-      cp -pr ~/config_2nd build
-    else
-      mkdir build
-    fi
-  - mkdir config_1st config_2nd gems/src
-  - chmod -R a-w .
-  - chmod -R u+w build config_1st config_2nd gems/src
-  - cd build
-  - |-
-    case "$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 MSPECOPT=-ff # 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 @@
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+ "windows_i686_msvc 0.52.6",
+ "windows_x86_64_gnu 0.52.6",
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+]
+
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+]
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+ "indexmap",
+ "prettyplease",
+ "syn",
+ "wasm-metadata",
+ "wit-bindgen-core",
+ "wit-component",
+]
+
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+ "prettyplease",
+ "proc-macro2",
+ "quote",
+ "syn",
+ "wit-bindgen-core",
+ "wit-bindgen-rust",
+]
+
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+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.
+
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+
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+         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.
+
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+
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+         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
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+         "Derivative Works" shall mean any work, whether in Source or Object
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+         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.
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+         "Contribution" shall mean any work of authorship, including
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+         to that Work or Derivative Works thereof, that is intentionally
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+         "Contributor" shall mean Licensor and any individual or Legal Entity
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+         worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+         copyright license to reproduce, prepare Derivative Works of,
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+
+         a.  You must give any other recipients of the Work or
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+
+         b.  You must cause any modified files to carry prominent notices
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+
+         c.  You must retain, in the Source form of any Derivative Works
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+             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
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+             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 1977e2bca1..9ff290ad75 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -1,46 +1,138 @@
-# 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
 
+* `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
 
 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]]
+
+* ENV
+
+    * `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]]
+
+* Kernel
+
+    * `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]]
+
+* MatchData
+
+    * `MatchData#integer_at` is added.  It converts the matched substring to
+      integer and return the result.  [[Feature #21932]]
 
-* String
+* Regexp
 
-    * `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]]
+    * All instances of `Regexp` are now frozen, not just literals.
+      Subclasses of `Regexp` are not frozen for compatibility.
+      [[Feature #8948]]
+
+* Set
+
+    * A deprecated behavior, `Set#to_set`, `Range#to_set`, and
+      `Enumerable#to_set` accepting arguments, was removed.  [[Feature #21390]]
 
 ## Stdlib updates
 
-The following default gems are updated.
+### 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
 
-* RubyGems 3.5.0.dev
-* bundler 2.5.0.dev
-* csv 3.2.7
-* fiddle 1.1.2
-* optparse 0.4.0.pre.1
-* psych 5.1.0
-* stringio 3.0.6
-* strscan 3.0.6
+### The following default gem is added.
 
-The following bundled gems are updated.
+### The following default gems are updated.
 
-* minitest 5.17.0
-* rbs 2.8.4
-* typeprof 0.21.4
+* 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]
 
-See GitHub releases like [Logger](https://github.com/ruby/logger/releases) or
-changelog for details of the default gems or bundled gems.
+### 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.
 
 ## Supported platforms
 
@@ -50,9 +142,128 @@ changelog for details of the default gems or bundled gems.
 
 ## C API updates
 
+### Embedded TypedData
+
+* 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]]
+
+* 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`.
+
+  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.
+
+  - `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)`
+
+  [[Feature #21861]]
+
+### Removed APIs
+
+The following APIs, which have been deprecated for many years, are removed.
+[[Feature #21768]]
+
+* 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
 
+### 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
 
-[Bug #19150]:     https://bugs.ruby-lang.org/issues/19150
-[Feature #19314]: https://bugs.ruby-lang.org/issues/19314
+[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 eab96b0b0b..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: MJIT](https://github.com/ruby/ruby/workflows/MJIT/badge.svg)](https://github.com/ruby/ruby/actions?query=workflow%3A"MJIT")
 [![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
 
@@ -26,7 +26,7 @@ Rubyはテキスト処理関係の能力などに優れ，Perlと同じくらい
 *   ダイナミックローディング (アーキテクチャによる)
 *   移植性が高い．多くのUnix-like/POSIX互換プラットフォーム上で動くだけでなく，Windows， macOS，
     Haikuなどの上でも動く cf.
-    https://github.com/ruby/ruby/blob/master/doc/contributing.rdoc#platform-maintainers
+    https://docs.ruby-lang.org/en/master/maintainers_md.html#label-Platform+Maintainers
 
 
 ## 入手法
@@ -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．
@@ -60,20 +64,20 @@ https://www.ruby-lang.org/
 
 ## メーリングリスト
 
-Rubyのメーリングリストがあります．参加希望の方は [ruby-list-request@ruby-lang.org] まで本文に
+Rubyのメーリングリストがあります．参加希望の方は [ruby-list-request@ml.ruby-lang.org] まで件名に
 
-    subscribe
+    join
 
 と書いて送って下さい．
 
 Ruby開発者向けメーリングリストもあります．こちらではrubyのバグ，将来の仕様拡張など実装上の問題について議論されています．
-参加希望の方は [ruby-dev-request@ruby-lang.org] までruby-listと同様の方法でメールしてください．
+参加希望の方は [ruby-dev-request@ml.ruby-lang.org] までruby-listと同様の方法でメールしてください．
 
 Ruby拡張モジュールについて話し合うruby-extメーリングリストと数学関係の話題について話し合うruby-mathメーリングリストと
 英語でrubyについて話し合うruby-talkメーリングリストもあります．参加方法はどれも同じです．
 
-[ruby-list-request@ruby-lang.org]: mailto:ruby-list-request@ruby-lang.org?subject=Join%20Ruby%20Mailing%20List&body=subscribe
-[ruby-dev-request@ruby-lang.org]: mailto:ruby-dev-request@ruby-lang.org?subject=Join%20Ruby%20Mailing%20List&body=subscribe
+[ruby-list-request@ml.ruby-lang.org]: mailto:ruby-list-request@ml.ruby-lang.org?subject=join
+[ruby-dev-request@ml.ruby-lang.org]: mailto:ruby-dev-request@ml.ruby-lang.org?subject=join
 
 ## コンパイル・インストール
 
@@ -152,7 +156,7 @@ UNIXであれば `configure` がほとんどの差異を吸収してくれるは
 
 ## 配布条件
 
-[COPYING.ja](COPYING.ja) ファイルを参照してください．
+[COPYING.ja](https://docs.ruby-lang.org/en/master/COPYING_ja.html) ファイルを参照してください．
 
 ## フィードバック
 
diff --git a/README.md b/README.md
index a841a2f2df..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: MJIT](https://github.com/ruby/ruby/workflows/MJIT/badge.svg)](https://github.com/ruby/ruby/actions?query=workflow%3A"MJIT")
 [![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?
 
@@ -25,7 +24,7 @@ It is simple, straightforward, and extensible.
 * Dynamic Loading of Object Files (on some architectures)
 * Highly Portable (works on many Unix-like/POSIX compatible platforms as
   well as Windows, macOS, etc.) cf.
-  https://github.com/ruby/ruby/blob/master/doc/maintainers.md#platform-maintainers
+    https://docs.ruby-lang.org/en/master/maintainers_md.html#label-Platform+Maintainers
 
 ## How to get Ruby
 
@@ -34,8 +33,8 @@ like rvm, see:
 
 https://www.ruby-lang.org/en/downloads/
 
-Our official distribution site is https://cache.ruby-lang.org/pub/ruby/. You can download
-the whole archive of the release packages and the snapshot of the repository.
+You can download release packages and the snapshot of the repository. If you want to
+download whole versions of Ruby, please visit https://www.ruby-lang.org/en/downloads/releases/.
 
 ### Download with Git
 
@@ -53,7 +52,7 @@ if you are a committer.
 
 ## How to build
 
-see [Building Ruby](doc/contributing/building_ruby.md)
+See [Building Ruby](https://docs.ruby-lang.org/en/master/contributing/building_ruby_md.html)
 
 ## Ruby home page
 
@@ -69,11 +68,11 @@ https://www.ruby-lang.org/
 There is a mailing list to discuss Ruby. To subscribe to this list, please
 send the following phrase:
 
-    subscribe
+    join
 
-in the mail body (not subject) to the address [ruby-talk-request@ruby-lang.org].
+in the mail subject (not body) to the address [ruby-talk-request@ml.ruby-lang.org].
 
-[ruby-talk-request@ruby-lang.org]: mailto:ruby-talk-request@ruby-lang.org?subject=Join%20Ruby%20Mailing%20List&body=subscribe
+[ruby-talk-request@ml.ruby-lang.org]: mailto:ruby-talk-request@ml.ruby-lang.org?subject=join
 
 ## Copying
 
@@ -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 1c8de350d9..19a6a425c1 100644
--- a/addr2line.c
+++ b/addr2line.c
@@ -8,10 +8,14 @@
 
 **********************************************************************/
 
-#if defined(__clang__)
+#if defined(__clang__) && defined(__has_warning)
+#if __has_warning("-Wgnu-empty-initializer")
 #pragma clang diagnostic ignored "-Wgnu-empty-initializer"
+#endif
+#if __has_warning("-Wgcc-compat")
 #pragma clang diagnostic ignored "-Wgcc-compat"
 #endif
+#endif
 
 #include "ruby/internal/config.h"
 #include "ruby/defines.h"
@@ -52,13 +56,26 @@
 #  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
+# ifndef UNREACHABLE_RETURN
+#  define UNREACHABLE_RETURN(_) __builtin_unreachable()
+# endif
 #endif /* __GNUC__ */
 
+#ifndef UNREACHABLE
+# define UNREACHABLE abort()
+#endif
+#ifndef UNREACHABLE_RETURN
+# define UNREACHABLE_RETURN(_) return (abort(), (_))
+#endif
+
 #ifdef HAVE_DLADDR
 # include <dlfcn.h>
 #endif
@@ -127,7 +144,7 @@ void *alloca();
 #define DW_LNE_define_file              0x03
 #define DW_LNE_set_discriminator        0x04  /* DWARF4 */
 
-PRINTF_ARGS(static int kprintf(const char *fmt, ...), 1, 2);
+#define kprintf(...) fprintf(errout, "" __VA_ARGS__)
 
 typedef struct line_info {
     const char *dirname;
@@ -184,7 +201,7 @@ obj_dwarf_section_at(obj_info_t *obj, int n)
         &obj->debug_line_str
     };
     if (n < 0 || DWARF_SECTION_COUNT <= n) {
-        abort();
+        UNREACHABLE_RETURN(0);
     }
     return ary[n];
 }
@@ -203,13 +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;
 }
@@ -220,44 +237,48 @@ 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;
 }
 
 static const char *
-get_nth_dirname(unsigned long dir, const char *p)
+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;
 }
 
-static const char *parse_ver5_debug_line_header(const char *p, int idx, uint8_t format, obj_info_t *obj, const char **out_path, uint64_t *out_directory_index);
+static const char *parse_ver5_debug_line_header(
+    const char *p, int idx, uint8_t format,
+    obj_info_t *obj, const char **out_path,
+    uint64_t *out_directory_index, FILE *errout);
 
 static void
-fill_filename(int file, uint8_t format, uint16_t version, const char *include_directories, const char *filenames, line_info_t *line, obj_info_t *obj)
+fill_filename(int file, uint8_t format, uint16_t version, const char *include_directories,
+              const char *filenames, line_info_t *line, obj_info_t *obj, FILE *errout)
 {
     int i;
     const char *p = filenames;
@@ -266,18 +287,20 @@ fill_filename(int file, uint8_t format, uint16_t version, const char *include_di
     if (version >= 5) {
         const char *path;
         uint64_t directory_index = -1;
-        parse_ver5_debug_line_header(filenames, file, format, obj, &path, &directory_index);
+        parse_ver5_debug_line_header(filenames, file, format, obj, &path, &directory_index, errout);
         line->filename = path;
-        parse_ver5_debug_line_header(include_directories, (int)directory_index, format, obj, &path, NULL);
+        parse_ver5_debug_line_header(include_directories, (int)directory_index, format, obj, &path, NULL, errout);
         line->dirname = path;
     }
     else {
         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++;
@@ -290,7 +313,7 @@ fill_filename(int file, uint8_t format, uint16_t version, const char *include_di
 
             if (i == file) {
                 line->filename = filename;
-                line->dirname = get_nth_dirname(dir, include_directories);
+                line->dirname = get_nth_dirname(dir, include_directories, errout);
             }
         }
     }
@@ -298,19 +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)
+          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);
-	    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;
+        }
     }
 }
 
@@ -333,7 +356,7 @@ struct LineNumberProgramHeader {
 };
 
 static int
-parse_debug_line_header(obj_info_t *obj, const char **pp, struct LineNumberProgramHeader *header)
+parse_debug_line_header(obj_info_t *obj, const char **pp, struct LineNumberProgramHeader *header, FILE *errout)
 {
     const char *p = *pp;
     header->unit_length = *(uint32_t *)p;
@@ -341,8 +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;
     }
 
@@ -379,7 +402,7 @@ parse_debug_line_header(obj_info_t *obj, const char **pp, struct LineNumberProgr
 
     if (header->version >= 5) {
         header->include_directories = p;
-        p = parse_ver5_debug_line_header(p, -1, header->format, obj, NULL, NULL);
+        p = parse_ver5_debug_line_header(p, -1, header->format, obj, NULL, NULL, errout);
         header->filenames = p;
     }
     else {
@@ -406,7 +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)
+                obj_info_t *obj, line_info_t *lines, int offset, FILE *errout)
 {
     const char *p = (const char *)*debug_line;
     struct LineNumberProgramHeader header;
@@ -423,109 +446,109 @@ parse_debug_line_cu(int num_traces, void **traces, const char **debug_line,
     /* int epilogue_begin = 0; */
     /* unsigned int isa = 0; */
 
-    if (parse_debug_line_header(obj, &p, &header))
+    if (parse_debug_line_header(obj, &p, &header, errout))
         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);				    \
-	/*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;
@@ -533,17 +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)
+                 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))
-	    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;
 }
@@ -551,7 +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);
+           obj_info_t **objp, line_info_t *lines, int offset, FILE *errout);
 
 static void
 append_obj(obj_info_t **objp)
@@ -579,7 +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)
+                 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;
@@ -589,13 +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;
@@ -605,21 +628,22 @@ follow_debuglink(const char *debuglink, int num_traces, void **traces,
     o2 = *objp;
     o2->base_addr = o1->base_addr;
     o2->path = o1->path;
-    fill_lines(num_traces, traces, 0, objp, lines, offset);
+    fill_lines(num_traces, traces, 0, objp, lines, offset, errout);
 }
 
 // check the path pattern of "/usr/lib/debug/.build-id/ab/cdef1234.debug"
 static void
 follow_debuglink_build_id(const char *build_id, size_t build_id_size, int num_traces, void **traces,
-                          obj_info_t **objp, line_info_t *lines, int offset)
+                          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;
@@ -630,13 +654,13 @@ 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;
     o2->base_addr = o1->base_addr;
     o2->path = o1->path;
-    fill_lines(num_traces, traces, 0, objp, lines, offset);
+    fill_lines(num_traces, traces, 0, objp, lines, offset, errout);
 }
 #endif
 
@@ -840,7 +864,11 @@ enum
     DW_FORM_addrx1 = 0x29,
     DW_FORM_addrx2 = 0x2a,
     DW_FORM_addrx3 = 0x2b,
-    DW_FORM_addrx4 = 0x2c
+    DW_FORM_addrx4 = 0x2c,
+
+    /* GNU extensions for referring to .gnu_debugaltlink dwz-compressed info */
+    DW_FORM_GNU_ref_alt = 0x1f20,
+    DW_FORM_GNU_strp_alt = 0x1f21
 };
 
 /* Range list entry encodings */
@@ -1058,13 +1086,13 @@ di_read_debug_abbrev_cu(DebugInfoReader *reader)
 }
 
 static int
-di_read_debug_line_cu(DebugInfoReader *reader)
+di_read_debug_line_cu(DebugInfoReader *reader, FILE *errout)
 {
     const char *p;
     struct LineNumberProgramHeader header;
 
     p = (const char *)reader->debug_line_cu_end;
-    if (parse_debug_line_header(reader->obj, &p, &header))
+    if (parse_debug_line_header(reader->obj, &p, &header, errout))
         return -1;
 
     reader->debug_line_cu_end = (char *)header.cu_end;
@@ -1144,19 +1172,32 @@ resolve_strx(DebugInfoReader *reader, uint64_t idx)
     return reader->obj->debug_str.ptr + off;
 }
 
-static void
-debug_info_reader_read_value(DebugInfoReader *reader, uint64_t form, DebugInfoValue *v)
+static bool
+debug_info_reader_read_addr_value_member(DebugInfoReader *reader, DebugInfoValue *v, int size)
+{
+    if (size == 4) {
+        set_uint_value(v, read_uint32(&reader->p));
+    } else if (size == 8) {
+        set_uint_value(v, read_uint64(&reader->p));
+    } else {
+        return false;
+    }
+    return true;
+}
+
+#define debug_info_reader_read_addr_value(reader, v, mem) \
+    if (!debug_info_reader_read_addr_value_member((reader), (v), (reader)->mem)) { \
+        kprintf("unknown " #mem ":%d", (reader)->mem); \
+        return false; \
+    }
+
+
+static bool
+debug_info_reader_read_value(DebugInfoReader *reader, uint64_t form, DebugInfoValue *v, FILE *errout)
 {
     switch (form) {
       case DW_FORM_addr:
-        if (reader->address_size == 4) {
-            set_uint_value(v, read_uint32(&reader->p));
-        } else if (reader->address_size == 8) {
-            set_uint_value(v, read_uint64(&reader->p));
-        } else {
-            fprintf(stderr,"unknown address_size:%d", reader->address_size);
-            abort();
-        }
+        debug_info_reader_read_addr_value(reader, v, address_size);
         break;
       case DW_FORM_block2:
         v->size = read_uint16(&reader->p);
@@ -1208,13 +1249,12 @@ debug_info_reader_read_value(DebugInfoReader *reader, uint64_t form, DebugInfoVa
         set_uint_value(v, read_uleb128(reader));
         break;
       case DW_FORM_ref_addr:
-        if (reader->format == 4) {
-            set_uint_value(v, read_uint32(&reader->p));
-        } else if (reader->format == 8) {
-            set_uint_value(v, read_uint64(&reader->p));
+        if (reader->current_version <= 2) {
+            // DWARF Version 2 specifies that references have
+            // the same size as an address on the target system
+            debug_info_reader_read_addr_value(reader, v, address_size);
         } else {
-            fprintf(stderr,"unknown format:%d", reader->format);
-            abort();
+            debug_info_reader_read_addr_value(reader, v, format);
         }
         break;
       case DW_FORM_ref1:
@@ -1315,20 +1355,28 @@ debug_info_reader_read_value(DebugInfoReader *reader, uint64_t form, DebugInfoVa
       case DW_FORM_addrx4:
         set_addr_idx_value(v, read_uint32(&reader->p));
         break;
+      /* we have no support for actually reading the real values of these refs out
+       * of the .gnu_debugaltlink dwz-compressed debuginfo at the moment, but "read"
+       * them anyway so that we advance the reader by the right amount. */
+      case DW_FORM_GNU_ref_alt:
+      case DW_FORM_GNU_strp_alt:
+        read_uint(reader);
+        set_uint_value(v, 0);
+        break;
       case 0:
         goto fail;
         break;
     }
-    return;
+    return true;
 
   fail:
-    fprintf(stderr, "%d: unsupported form: %#"PRIx64"\n", __LINE__, form);
-    exit(1);
+    kprintf("%d: unsupported form: %#"PRIx64"\n", __LINE__, form);
+    return false;
 }
 
 /* find abbrev in current compilation unit */
 static const char *
-di_find_abbrev(DebugInfoReader *reader, uint64_t abbrev_number)
+di_find_abbrev(DebugInfoReader *reader, uint64_t abbrev_number, FILE *errout)
 {
     const char *p;
     if (abbrev_number < ABBREV_TABLE_SIZE) {
@@ -1341,8 +1389,8 @@ di_find_abbrev(DebugInfoReader *reader, uint64_t abbrev_number)
     di_skip_die_attributes(&p);
     for (uint64_t n = uleb128(&p); abbrev_number != n; n = uleb128(&p)) {
         if (n == 0) {
-            fprintf(stderr,"%d: Abbrev Number %"PRId64" not found\n",__LINE__, abbrev_number);
-            exit(1);
+            kprintf("%d: Abbrev Number %"PRId64" not found\n",__LINE__, abbrev_number);
+            return NULL;
         }
         uleb128(&p); /* tag */
         p++; /* has_children */
@@ -1353,52 +1401,52 @@ di_find_abbrev(DebugInfoReader *reader, uint64_t abbrev_number)
 
 #if 0
 static void
-hexdump0(const unsigned char *p, size_t n)
+hexdump0(const unsigned char *p, size_t n, FILE *errout)
 {
     size_t i;
-    fprintf(stderr, "     0  1  2  3  4  5  6  7  8  9  A  B  C  D  E  F\n");
+    kprintf("     0  1  2  3  4  5  6  7  8  9  A  B  C  D  E  F\n");
     for (i=0; i < n; i++){
         switch (i & 15) {
           case 0:
-            fprintf(stderr, "%02" PRIdSIZE ": %02X ", i/16, p[i]);
+            kprintf("%02" PRIdSIZE ": %02X ", i/16, p[i]);
             break;
           case 15:
-            fprintf(stderr, "%02X\n", p[i]);
+            kprintf("%02X\n", p[i]);
             break;
           default:
-            fprintf(stderr, "%02X ", p[i]);
+            kprintf("%02X ", p[i]);
             break;
         }
     }
     if ((i & 15) != 15) {
-        fprintf(stderr, "\n");
+        kprintf("\n");
     }
 }
-#define hexdump(p,n) hexdump0((const unsigned char *)p, n)
+#define hexdump(p,n,e) hexdump0((const unsigned char *)p, n, e)
 
 static void
-div_inspect(DebugInfoValue *v)
+div_inspect(DebugInfoValue *v, FILE *errout)
 {
     switch (v->type) {
       case VAL_uint:
-        fprintf(stderr,"%d: type:%d size:%" PRIxSIZE " v:%"PRIx64"\n",__LINE__,v->type,v->size,v->as.uint64);
+        kprintf("%d: type:%d size:%" PRIxSIZE " v:%"PRIx64"\n",__LINE__,v->type,v->size,v->as.uint64);
         break;
       case VAL_int:
-        fprintf(stderr,"%d: type:%d size:%" PRIxSIZE " v:%"PRId64"\n",__LINE__,v->type,v->size,(int64_t)v->as.uint64);
+        kprintf("%d: type:%d size:%" PRIxSIZE " v:%"PRId64"\n",__LINE__,v->type,v->size,(int64_t)v->as.uint64);
         break;
       case VAL_cstr:
-        fprintf(stderr,"%d: type:%d size:%" PRIxSIZE " v:'%s'\n",__LINE__,v->type,v->size,v->as.ptr);
+        kprintf("%d: type:%d size:%" PRIxSIZE " v:'%s'\n",__LINE__,v->type,v->size,v->as.ptr);
         break;
       case VAL_data:
-        fprintf(stderr,"%d: type:%d size:%" PRIxSIZE " v:\n",__LINE__,v->type,v->size);
-        hexdump(v->as.ptr, 16);
+        kprintf("%d: type:%d size:%" PRIxSIZE " v:\n",__LINE__,v->type,v->size);
+        hexdump(v->as.ptr, 16, errout);
         break;
     }
 }
 #endif
 
 static DIE *
-di_read_die(DebugInfoReader *reader, DIE *die)
+di_read_die(DebugInfoReader *reader, DIE *die, FILE *errout)
 {
     uint64_t abbrev_number = uleb128(&reader->p);
     if (abbrev_number == 0) {
@@ -1406,7 +1454,7 @@ di_read_die(DebugInfoReader *reader, DIE *die)
         return NULL;
     }
 
-    reader->q = di_find_abbrev(reader, abbrev_number);
+    if (!(reader->q = di_find_abbrev(reader, abbrev_number, errout))) return NULL;
 
     die->pos = reader->p - reader->obj->debug_info.ptr - 1;
     die->tag = (int)uleb128(&reader->q); /* tag */
@@ -1418,26 +1466,26 @@ di_read_die(DebugInfoReader *reader, DIE *die)
 }
 
 static DebugInfoValue *
-di_read_record(DebugInfoReader *reader, DebugInfoValue *vp)
+di_read_record(DebugInfoReader *reader, DebugInfoValue *vp, FILE *errout)
 {
     uint64_t at = uleb128(&reader->q);
     uint64_t form = uleb128(&reader->q);
     if (!at || !form) return NULL;
     vp->at = at;
     vp->form = form;
-    debug_info_reader_read_value(reader, form, vp);
+    if (!debug_info_reader_read_value(reader, form, vp, errout)) return NULL;
     return vp;
 }
 
-static void
-di_skip_records(DebugInfoReader *reader)
+static bool
+di_skip_records(DebugInfoReader *reader, FILE *errout)
 {
     for (;;) {
-        DebugInfoValue v = {{}};
+        DebugInfoValue v = {{0}};
         uint64_t at = uleb128(&reader->q);
         uint64_t form = uleb128(&reader->q);
-        if (!at || !form) return;
-        debug_info_reader_read_value(reader, form, &v);
+        if (!at || !form) return true;
+        if (!debug_info_reader_read_value(reader, form, &v, errout)) return false;
     }
 }
 
@@ -1449,13 +1497,14 @@ typedef struct addr_header {
     /* uint8_t segment_selector_size; */
 } addr_header_t;
 
-static void
-addr_header_init(obj_info_t *obj, addr_header_t *header) {
+static bool
+addr_header_init(obj_info_t *obj, addr_header_t *header, FILE *errout)
+{
     const char *p = obj->debug_addr.ptr;
 
     header->ptr = p;
 
-    if (!p) return;
+    if (!p) return true;
 
     header->unit_length = *(uint32_t *)p;
     p += sizeof(uint32_t);
@@ -1469,7 +1518,12 @@ addr_header_init(obj_info_t *obj, addr_header_t *header) {
 
     p += 2; /* version */
     header->address_size = *p++;
+    if (header->address_size != 4 && header->address_size != 8) {
+        kprintf("unknown address_size:%d", header->address_size);
+        return false;
+    }
     p++; /* segment_selector_size */
+    return true;
 }
 
 static uint64_t
@@ -1489,11 +1543,12 @@ typedef struct rnglists_header {
     uint32_t offset_entry_count;
 } rnglists_header_t;
 
-static void
-rnglists_header_init(obj_info_t *obj, rnglists_header_t *header) {
+static bool
+rnglists_header_init(obj_info_t *obj, rnglists_header_t *header, FILE *errout)
+{
     const char *p = obj->debug_rnglists.ptr;
 
-    if (!p) return;
+    if (!p) return true;
 
     header->unit_length = *(uint32_t *)p;
     p += sizeof(uint32_t);
@@ -1507,8 +1562,13 @@ rnglists_header_init(obj_info_t *obj, rnglists_header_t *header) {
 
     p += 2; /* version */
     header->address_size = *p++;
+    if (header->address_size != 4 && header->address_size != 8) {
+        kprintf("unknown address_size:%d", header->address_size);
+        return false;
+    }
     p++; /* segment_selector_size */
     header->offset_entry_count = *(uint32_t *)p;
+    return true;
 }
 
 typedef struct {
@@ -1552,26 +1612,23 @@ ranges_set(ranges_t *ptr, DebugInfoValue *v, addr_header_t *addr_header, uint64_
 }
 
 static uint64_t
-read_dw_form_addr(DebugInfoReader *reader, const char **ptr)
+read_dw_form_addr(DebugInfoReader *reader, const char **ptr, FILE *errout)
 {
     const char *p = *ptr;
     *ptr = p + reader->address_size;
     if (reader->address_size == 4) {
         return read_uint32(&p);
-    } else if (reader->address_size == 8) {
-        return read_uint64(&p);
     } else {
-        fprintf(stderr,"unknown address_size:%d", reader->address_size);
-        abort();
+        return read_uint64(&p);
     }
 }
 
 static uintptr_t
-ranges_include(DebugInfoReader *reader, ranges_t *ptr, uint64_t addr, rnglists_header_t *rnglists_header)
+ranges_include(DebugInfoReader *reader, ranges_t *ptr, uint64_t addr, rnglists_header_t *rnglists_header, FILE *errout)
 {
     if (ptr->high_pc_set) {
         if (ptr->ranges_set || !ptr->low_pc_set) {
-            exit(1);
+            return UINTPTR_MAX;
         }
         if (ptr->low_pc <= addr && addr <= ptr->high_pc) {
             return (uintptr_t)ptr->low_pc;
@@ -1620,15 +1677,15 @@ ranges_include(DebugInfoReader *reader, ranges_t *ptr, uint64_t addr, rnglists_h
                     to = (uintptr_t)base + uleb128(&p);
                     break;
                   case DW_RLE_base_address:
-                    base = read_dw_form_addr(reader, &p);
+                    base = read_dw_form_addr(reader, &p, errout);
                     base_valid = true;
                     break;
                   case DW_RLE_start_end:
-                    from = (uintptr_t)read_dw_form_addr(reader, &p);
-                    to = (uintptr_t)read_dw_form_addr(reader, &p);
+                    from = (uintptr_t)read_dw_form_addr(reader, &p, errout);
+                    to = (uintptr_t)read_dw_form_addr(reader, &p, errout);
                     break;
                   case DW_RLE_start_length:
-                    from = (uintptr_t)read_dw_form_addr(reader, &p);
+                    from = (uintptr_t)read_dw_form_addr(reader, &p, errout);
                     to = from + uleb128(&p);
                     break;
                 }
@@ -1636,7 +1693,7 @@ ranges_include(DebugInfoReader *reader, ranges_t *ptr, uint64_t addr, rnglists_h
                     return from;
                 }
             }
-            return false;
+            return 0;
         }
         p = reader->obj->debug_ranges.ptr + ptr->ranges;
         for (;;) {
@@ -1657,42 +1714,42 @@ ranges_include(DebugInfoReader *reader, ranges_t *ptr, uint64_t addr, rnglists_h
             return (uintptr_t)ptr->low_pc;
         }
     }
-    return false;
+    return 0;
 }
 
 #if 0
 static void
-ranges_inspect(DebugInfoReader *reader, ranges_t *ptr)
+ranges_inspect(DebugInfoReader *reader, ranges_t *ptr, FILE *errout)
 {
     if (ptr->high_pc_set) {
         if (ptr->ranges_set || !ptr->low_pc_set) {
-            fprintf(stderr,"low_pc_set:%d high_pc_set:%d ranges_set:%d\n",ptr->low_pc_set,ptr->high_pc_set,ptr->ranges_set);
-            exit(1);
+            kprintf("low_pc_set:%d high_pc_set:%d ranges_set:%d\n",ptr->low_pc_set,ptr->high_pc_set,ptr->ranges_set);
+            return;
         }
-        fprintf(stderr,"low_pc:%"PRIx64" high_pc:%"PRIx64"\n",ptr->low_pc,ptr->high_pc);
+        kprintf("low_pc:%"PRIx64" high_pc:%"PRIx64"\n",ptr->low_pc,ptr->high_pc);
     }
     else if (ptr->ranges_set) {
         char *p = reader->obj->debug_ranges.ptr + ptr->ranges;
-        fprintf(stderr,"low_pc:%"PRIx64" ranges:%"PRIx64" %lx ",ptr->low_pc,ptr->ranges, p-reader->obj->mapped);
+        kprintf("low_pc:%"PRIx64" ranges:%"PRIx64" %lx ",ptr->low_pc,ptr->ranges, p-reader->obj->mapped);
         for (;;) {
             uintptr_t from = read_uintptr(&p);
             uintptr_t to = read_uintptr(&p);
             if (!from && !to) break;
-            fprintf(stderr,"%"PRIx64"-%"PRIx64" ",ptr->low_pc+from,ptr->low_pc+to);
+            kprintf("%"PRIx64"-%"PRIx64" ",ptr->low_pc+from,ptr->low_pc+to);
         }
-        fprintf(stderr,"\n");
+        kprintf("\n");
     }
     else if (ptr->low_pc_set) {
-        fprintf(stderr,"low_pc:%"PRIx64"\n",ptr->low_pc);
+        kprintf("low_pc:%"PRIx64"\n",ptr->low_pc);
     }
     else {
-        fprintf(stderr,"empty\n");
+        kprintf("empty\n");
     }
 }
 #endif
 
 static int
-di_read_cu(DebugInfoReader *reader)
+di_read_cu(DebugInfoReader *reader, FILE *errout)
 {
     uint64_t unit_length;
     uint16_t version;
@@ -1719,19 +1776,23 @@ di_read_cu(DebugInfoReader *reader)
         debug_abbrev_offset = read_uint(reader);
         reader->address_size = read_uint8(&reader->p);
     }
+    if (reader->address_size != 4 && reader->address_size != 8) {
+        kprintf("unknown address_size:%d", reader->address_size);
+        return -1;
+    }
     reader->q0 = reader->obj->debug_abbrev.ptr + debug_abbrev_offset;
 
     reader->level = 0;
     di_read_debug_abbrev_cu(reader);
-    if (di_read_debug_line_cu(reader)) return -1;
+    if (di_read_debug_line_cu(reader, errout)) return -1;
 
     do {
         DIE die;
 
-        if (!di_read_die(reader, &die)) continue;
+        if (!di_read_die(reader, &die, errout)) continue;
 
         if (die.tag != DW_TAG_compile_unit) {
-            di_skip_records(reader);
+            if (!di_skip_records(reader, errout)) return -1;
             break;
         }
 
@@ -1739,11 +1800,11 @@ di_read_cu(DebugInfoReader *reader)
         reader->current_addr_base = 0;
         reader->current_rnglists_base = 0;
 
-        DebugInfoValue low_pc = {{}};
+        DebugInfoValue low_pc = {{0}};
         /* enumerate abbrev */
         for (;;) {
-            DebugInfoValue v = {{}};
-            if (!di_read_record(reader, &v)) break;
+            DebugInfoValue v = {{0}};
+            if (!di_read_record(reader, &v, errout)) break;
             switch (v.at) {
               case DW_AT_low_pc:
                 // clang may output DW_AT_addr_base after DW_AT_low_pc.
@@ -1768,8 +1829,8 @@ di_read_cu(DebugInfoReader *reader)
                 break;
             case VAL_addr:
                 {
-                    addr_header_t header = {};
-                    addr_header_init(reader->obj, &header);
+                    addr_header_t header = {0};
+                    if (!addr_header_init(reader->obj, &header, errout)) return -1;
                     reader->current_low_pc = read_addr(&header, reader->current_addr_base, low_pc.as.addr_idx);
                 }
                 break;
@@ -1780,7 +1841,7 @@ di_read_cu(DebugInfoReader *reader)
 }
 
 static void
-read_abstract_origin(DebugInfoReader *reader, uint64_t form, uint64_t abstract_origin, line_info_t *line)
+read_abstract_origin(DebugInfoReader *reader, uint64_t form, uint64_t abstract_origin, line_info_t *line, FILE *errout)
 {
     const char *p = reader->p;
     const char *q = reader->q;
@@ -1805,12 +1866,12 @@ read_abstract_origin(DebugInfoReader *reader, uint64_t form, uint64_t abstract_o
       default:
         goto finish;
     }
-    if (!di_read_die(reader, &die)) goto finish;
+    if (!di_read_die(reader, &die, errout)) goto finish;
 
     /* enumerate abbrev */
     for (;;) {
-        DebugInfoValue v = {{}};
-        if (!di_read_record(reader, &v)) break;
+        DebugInfoValue v = {{0}};
+        if (!di_read_record(reader, &v, errout)) break;
         switch (v.at) {
           case DW_AT_name:
             line->sname = get_cstr_value(&v);
@@ -1824,43 +1885,44 @@ read_abstract_origin(DebugInfoReader *reader, uint64_t form, uint64_t abstract_o
     reader->level = level;
 }
 
-static void
+static bool
 debug_info_read(DebugInfoReader *reader, int num_traces, void **traces,
-         line_info_t *lines, int offset) {
+                line_info_t *lines, int offset, FILE *errout)
+{
 
-    addr_header_t addr_header = {};
-    addr_header_init(reader->obj, &addr_header);
+    addr_header_t addr_header = {0};
+    if (!addr_header_init(reader->obj, &addr_header, errout)) return false;
 
-    rnglists_header_t rnglists_header = {};
-    rnglists_header_init(reader->obj, &rnglists_header);
+    rnglists_header_t rnglists_header = {0};
+    if (!rnglists_header_init(reader->obj, &rnglists_header, errout)) return false;
 
     while (reader->p < reader->cu_end) {
         DIE die;
-        ranges_t ranges = {};
-        line_info_t line = {};
+        ranges_t ranges = {0};
+        line_info_t line = {0};
 
-        if (!di_read_die(reader, &die)) continue;
-        /* fprintf(stderr,"%d:%tx: <%d>\n",__LINE__,die.pos,reader->level,die.tag); */
+        if (!di_read_die(reader, &die, errout)) continue;
+        /* kprintf("%d:%tx: <%d>\n",__LINE__,die.pos,reader->level,die.tag); */
 
         if (die.tag != DW_TAG_subprogram && die.tag != DW_TAG_inlined_subroutine) {
           skip_die:
-            di_skip_records(reader);
+            if (!di_skip_records(reader, errout)) return false;
             continue;
         }
 
         /* enumerate abbrev */
         for (;;) {
-            DebugInfoValue v = {{}};
+            DebugInfoValue v = {{0}};
             /* ptrdiff_t pos = reader->p - reader->p0; */
-            if (!di_read_record(reader, &v)) break;
-            /* fprintf(stderr,"\n%d:%tx: AT:%lx FORM:%lx\n",__LINE__,pos,v.at,v.form); */
-            /* div_inspect(&v); */
+            if (!di_read_record(reader, &v, errout)) break;
+            /* kprintf("\n%d:%tx: AT:%lx FORM:%lx\n",__LINE__,pos,v.at,v.form); */
+            /* div_inspect(&v, errout); */
             switch (v.at) {
               case DW_AT_name:
                 line.sname = get_cstr_value(&v);
                 break;
               case DW_AT_call_file:
-                fill_filename((int)v.as.uint64, reader->debug_line_format, reader->debug_line_version, reader->debug_line_directories, reader->debug_line_files, &line, reader->obj);
+                fill_filename((int)v.as.uint64, reader->debug_line_format, reader->debug_line_version, reader->debug_line_directories, reader->debug_line_files, &line, reader->obj, errout);
                 break;
               case DW_AT_call_line:
                 line.line = (int)v.as.uint64;
@@ -1876,18 +1938,19 @@ debug_info_read(DebugInfoReader *reader, int num_traces, void **traces,
                 /* 1 or 3 */
                 break; /* goto skip_die; */
               case DW_AT_abstract_origin:
-                read_abstract_origin(reader, v.form, v.as.uint64, &line);
+                read_abstract_origin(reader, v.form, v.as.uint64, &line, errout);
                 break; /* goto skip_die; */
             }
         }
-        /* ranges_inspect(reader, &ranges); */
-        /* fprintf(stderr,"%d:%tx: %x ",__LINE__,diepos,die.tag); */
+        /* ranges_inspect(reader, &ranges, errout); */
+        /* kprintf("%d:%tx: %x ",__LINE__,diepos,die.tag); */
         for (int i=offset; i < num_traces; i++) {
             uintptr_t addr = (uintptr_t)traces[i];
             uintptr_t offset = addr - reader->obj->base_addr + reader->obj->vmaddr;
-            uintptr_t saddr = ranges_include(reader, &ranges, offset, &rnglists_header);
+            uintptr_t saddr = ranges_include(reader, &ranges, offset, &rnglists_header, errout);
+            if (saddr == UINTPTR_MAX) return false;
             if (saddr) {
-                /* fprintf(stdout, "%d:%tx: %d %lx->%lx %x %s: %s/%s %d %s %s %s\n",__LINE__,die.pos, i,addr,offset, die.tag,line.sname,line.dirname,line.filename,line.line,reader->obj->path,line.sname,lines[i].sname); */
+                /* kprintf("%d:%tx: %d %lx->%lx %x %s: %s/%s %d %s %s %s\n",__LINE__,die.pos, i,addr,offset, die.tag,line.sname,line.dirname,line.filename,line.line,reader->obj->path,line.sname,lines[i].sname); */
                 if (lines[i].sname) {
                     line_info_t *lp = malloc(sizeof(line_info_t));
                     memcpy(lp, &lines[i], sizeof(line_info_t));
@@ -1904,6 +1967,7 @@ debug_info_read(DebugInfoReader *reader, int num_traces, void **traces,
             }
         }
     }
+    return true;
 }
 
 // This function parses the following attributes of Line Number Program Header in DWARF 5:
@@ -1922,7 +1986,10 @@ debug_info_read(DebugInfoReader *reader, int num_traces, void **traces,
 //
 // It records DW_LNCT_path and DW_LNCT_directory_index at the index "idx".
 static const char *
-parse_ver5_debug_line_header(const char *p, int idx, uint8_t format, obj_info_t *obj, const char **out_path, uint64_t *out_directory_index) {
+parse_ver5_debug_line_header(const char *p, int idx, uint8_t format,
+                             obj_info_t *obj, const char **out_path,
+                             uint64_t *out_directory_index, FILE *errout)
+{
     int i, j;
     int entry_format_count = *(uint8_t *)p++;
     const char *entry_format = p;
@@ -1932,17 +1999,17 @@ parse_ver5_debug_line_header(const char *p, int idx, uint8_t format, obj_info_t
 
     int entry_count = (int)uleb128(&p);
 
-    DebugInfoReader reader;
+    DebugInfoReader reader = {0};
     debug_info_reader_init(&reader, obj);
     reader.format = format;
     reader.p = p;
     for (j = 0; j < entry_count; j++) {
         const char *format = entry_format;
         for (i = 0; i < entry_format_count; i++) {
-            DebugInfoValue v = {{}};
+            DebugInfoValue v = {{0}};
             unsigned long dw_lnct = uleb128(&format);
             unsigned long dw_form = uleb128(&format);
-            debug_info_reader_read_value(&reader, dw_form, &v);
+            if (!debug_info_reader_read_value(&reader, dw_form, &v, errout)) return 0;
             if (dw_lnct == 1 /* DW_LNCT_path */ && v.type == VAL_cstr && out_path)
                 *out_path = v.as.ptr + v.off;
             if (dw_lnct == 2 /* DW_LNCT_directory_index */ && v.type == VAL_uint && out_directory_index)
@@ -1965,14 +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;
@@ -1987,7 +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)
+           obj_info_t **objp, line_info_t *lines, int offset, FILE *errout)
 {
     int i, j;
     char *shstr;
@@ -2005,40 +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;
@@ -2050,32 +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",
@@ -2105,17 +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++) {
@@ -2132,14 +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) {
@@ -2147,9 +2213,10 @@ fill_lines(int num_traces, void **traces, int check_debuglink,
         debug_info_reader_init(&reader, obj);
         i = 0;
         while (reader.p < reader.pend) {
-            /* fprintf(stderr, "%d:%tx: CU[%d]\n", __LINE__, reader.p - reader.obj->debug_info.ptr, i++); */
-            if (di_read_cu(&reader)) goto use_symtab;
-            debug_info_read(&reader, num_traces, traces, lines, offset);
+            /* kprintf("%d:%tx: CU[%d]\n", __LINE__, reader.p - reader.obj->debug_info.ptr, i++); */
+            if (di_read_cu(&reader, errout)) goto use_symtab;
+            if (!debug_info_read(&reader, num_traces, traces, lines, offset, errout))
+                goto use_symtab;
         }
     }
     else {
@@ -2184,27 +2251,27 @@ 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);
-	}
+        /* 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,
-			       objp, lines, offset);
+                               num_traces, traces,
+                               objp, lines, offset, errout);
         }
-	goto finish;
+        goto finish;
     }
 
     if (parse_debug_line(num_traces, traces,
             obj->debug_line.ptr,
             obj->debug_line.size,
-            obj, lines, offset) == -1)
+            obj, lines, offset, errout) == -1)
         goto fail;
 
 finish:
@@ -2216,7 +2283,7 @@ 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)
+        obj_info_t **objp, line_info_t *lines, int offset, FILE *errout)
 {
 # ifdef __LP64__
 #  define LP(x) x##_64
@@ -2295,13 +2362,13 @@ fill_lines(int num_traces, void **traces, int check_debuglink,
         struct fat_header *fat = (struct fat_header *)file;
         char *q = file + sizeof(*fat);
         uint32_t nfat_arch = __builtin_bswap32(fat->nfat_arch);
-        /* fprintf(stderr,"%d: fat:%s %d\n",__LINE__, binary_filename,nfat_arch); */
+        /* kprintf("%d: fat:%s %d\n",__LINE__, binary_filename,nfat_arch); */
         for (uint32_t i = 0; i < nfat_arch; i++) {
             struct fat_arch *arch = (struct fat_arch *)q;
             cpu_type_t cputype = __builtin_bswap32(arch->cputype);
             cpu_subtype_t cpusubtype = __builtin_bswap32(arch->cpusubtype);
             uint32_t offset = __builtin_bswap32(arch->offset);
-            /* fprintf(stderr,"%d: fat %d %x/%x %x/%x\n",__LINE__, i, mhp->cputype,mhp->cpusubtype, cputype,cpusubtype); */
+            /* kprintf("%d: fat %d %x/%x %x/%x\n",__LINE__, i, mhp->cputype,mhp->cpusubtype, cputype,cpusubtype); */
             if (mhp->cputype == cputype &&
                     (cpu_subtype_t)(mhp->cpusubtype & ~CPU_SUBTYPE_MASK) == cpusubtype) {
                 p = file + offset;
@@ -2319,13 +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;
     }
@@ -2360,7 +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;
@@ -2417,15 +2495,16 @@ found_mach_header:
         DebugInfoReader reader;
         debug_info_reader_init(&reader, obj);
         while (reader.p < reader.pend) {
-            if (di_read_cu(&reader)) goto fail;
-            debug_info_read(&reader, num_traces, traces, lines, offset);
+            if (di_read_cu(&reader, errout)) goto fail;
+            if (!debug_info_read(&reader, num_traces, traces, lines, offset, errout))
+                goto fail;
         }
     }
 
     if (parse_debug_line(num_traces, traces,
             obj->debug_line.ptr,
             obj->debug_line.size,
-            obj, lines, offset) == -1)
+            obj, lines, offset, errout) == -1)
         goto fail;
 
     return dladdr_fbase;
@@ -2438,7 +2517,7 @@ fail:
 #if defined(__FreeBSD__) || defined(__DragonFly__)
 # include <sys/sysctl.h>
 #endif
-/* ssize_t main_exe_path(void)
+/* ssize_t main_exe_path(FILE *errout)
  *
  * store the path of the main executable to `binary_filename`,
  * and returns strlen(binary_filename).
@@ -2446,7 +2525,7 @@ fail:
  */
 #if defined(__linux__) || defined(__NetBSD__)
 static ssize_t
-main_exe_path(void)
+main_exe_path(FILE *errout)
 {
 # if defined(__linux__)
 #  define PROC_SELF_EXE "/proc/self/exe"
@@ -2460,21 +2539,21 @@ main_exe_path(void)
 }
 #elif defined(__FreeBSD__) || defined(__DragonFly__)
 static ssize_t
-main_exe_path(void)
+main_exe_path(FILE *errout)
 {
     int mib[4] = {CTL_KERN, KERN_PROC, KERN_PROC_PATHNAME, -1};
     size_t len = PATH_MAX;
     int err = sysctl(mib, 4, binary_filename, &len, NULL, 0);
     if (err) {
-	kprintf("Can't get the path of ruby");
-	return -1;
+        kprintf("Can't get the path of ruby");
+        return -1;
     }
     len--; /* sysctl sets strlen+1 */
     return len;
 }
 #elif defined(HAVE_LIBPROC_H)
 static ssize_t
-main_exe_path(void)
+main_exe_path(FILE *errout)
 {
     int len = proc_pidpath(getpid(), binary_filename, PATH_MAX);
     if (len == 0) return 0;
@@ -2486,7 +2565,7 @@ main_exe_path(void)
 #endif
 
 static void
-print_line0(line_info_t *line, void *address)
+print_line0(line_info_t *line, void *address, FILE *errout)
 {
     uintptr_t addr = (uintptr_t)address;
     uintptr_t d = addr - line->saddr;
@@ -2527,16 +2606,16 @@ print_line0(line_info_t *line, void *address)
 }
 
 static void
-print_line(line_info_t *line, void *address)
+print_line(line_info_t *line, void *address, FILE *errout)
 {
-    print_line0(line, address);
+    print_line0(line, address, errout);
     if (line->next) {
-        print_line(line->next, NULL);
+        print_line(line->next, NULL, errout);
     }
 }
 
 void
-rb_dump_backtrace_with_lines(int num_traces, void **traces)
+rb_dump_backtrace_with_lines(int num_traces, void **traces, FILE *errout)
 {
     int i;
     /* async-signal unsafe */
@@ -2548,80 +2627,80 @@ rb_dump_backtrace_with_lines(int num_traces, void **traces)
 #ifdef HAVE_MAIN_EXE_PATH
     char *main_path = NULL; /* used on printing backtrace */
     ssize_t len;
-    if ((len = main_exe_path()) > 0) {
-	main_path = (char *)alloca(len + 1);
-	if (main_path) {
-	    uintptr_t addr;
-	    memcpy(main_path, binary_filename, len+1);
-	    append_obj(&obj);
-	    obj->path = main_path;
-	    addr = fill_lines(num_traces, traces, 1, &obj, lines, -1);
-	    if (addr != (uintptr_t)-1) {
-		dladdr_fbases[0] = (void *)addr;
-	    }
-	}
+    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, 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) == (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]);
+        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;
@@ -2635,435 +2714,8 @@ next_line:
     free(dladdr_fbases);
 }
 
-/* From FreeBSD's lib/libstand/printf.c */
-/*-
- * Copyright (c) 1986, 1988, 1991, 1993
- *	The Regents of the University of California.  All rights reserved.
- * (c) UNIX System Laboratories, Inc.
- * All or some portions of this file are derived from material licensed
- * to the University of California by American Telephone and Telegraph
- * Co. or Unix System Laboratories, Inc. and are reproduced herein with
- * the permission of UNIX System Laboratories, Inc.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- * 1. Redistributions of source code must retain the above copyright
- *    notice, this list of conditions and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright
- *    notice, this list of conditions and the following disclaimer in the
- *    documentation and/or other materials provided with the distribution.
- * 4. Neither the name of the University nor the names of its contributors
- *    may be used to endorse or promote products derived from this software
- *    without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
- * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
- * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
- * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
- * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
- * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
- * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
- * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
- * SUCH DAMAGE.
- *
- *	@(#)subr_prf.c	8.3 (Berkeley) 1/21/94
- */
-
-#include <stdarg.h>
-#define MAXNBUF (sizeof(intmax_t) * CHAR_BIT + 1)
-static inline int toupper(int c) { return ('A' <= c && c <= 'Z') ? (c&0x5f) : c; }
-#define    hex2ascii(hex)  (hex2ascii_data[hex])
-static const char hex2ascii_data[] = "0123456789abcdefghijklmnopqrstuvwxyz";
-static inline int imax(int a, int b) { return (a > b ? a : b); }
-static int kvprintf(char const *fmt, void (*func)(int), void *arg, int radix, va_list ap);
-
-static void putce(int c)
-{
-    char s[1];
-    ssize_t ret;
-
-    s[0] = (char)c;
-    ret = write(2, s, 1);
-    (void)ret;
-}
-
-static int
-kprintf(const char *fmt, ...)
-{
-	va_list ap;
-	int retval;
+#undef kprintf
 
-	va_start(ap, fmt);
-	retval = kvprintf(fmt, putce, NULL, 10, ap);
-	va_end(ap);
-	return retval;
-}
-
-/*
- * Put a NUL-terminated ASCII number (base <= 36) in a buffer in reverse
- * order; return an optional length and a pointer to the last character
- * written in the buffer (i.e., the first character of the string).
- * The buffer pointed to by `nbuf' must have length >= MAXNBUF.
- */
-static char *
-ksprintn(char *nbuf, uintmax_t num, int base, int *lenp, int upper)
-{
-	char *p, c;
-
-	p = nbuf;
-	*p = '\0';
-	do {
-		c = hex2ascii(num % base);
-		*++p = upper ? toupper(c) : c;
-	} while (num /= base);
-	if (lenp)
-		*lenp = (int)(p - nbuf);
-	return (p);
-}
-
-/*
- * Scaled down version of printf(3).
- *
- * Two additional formats:
- *
- * The format %b is supported to decode error registers.
- * Its usage is:
- *
- *	printf("reg=%b\n", regval, "<base><arg>*");
- *
- * where <base> is the output base expressed as a control character, e.g.
- * \10 gives octal; \20 gives hex.  Each arg is a sequence of characters,
- * the first of which gives the bit number to be inspected (origin 1), and
- * the next characters (up to a control character, i.e. a character <= 32),
- * give the name of the register.  Thus:
- *
- *	kvprintf("reg=%b\n", 3, "\10\2BITTWO\1BITONE\n");
- *
- * would produce output:
- *
- *	reg=3<BITTWO,BITONE>
- *
- * XXX:  %D  -- Hexdump, takes pointer and separator string:
- *		("%6D", ptr, ":")   -> XX:XX:XX:XX:XX:XX
- *		("%*D", len, ptr, " " -> XX XX XX XX ...
- */
-static int
-kvprintf(char const *fmt, void (*func)(int), void *arg, int radix, va_list ap)
-{
-#define PCHAR(c) {int cc=(c); if (func) (*func)(cc); else *d++ = cc; retval++; }
-	char nbuf[MAXNBUF];
-	char *d;
-	const char *p, *percent, *q;
-	unsigned char *up;
-	int ch, n;
-	uintmax_t num;
-	int base, lflag, qflag, tmp, width, ladjust, sharpflag, neg, sign, dot;
-	int cflag, hflag, jflag, tflag, zflag;
-	int dwidth, upper;
-	char padc;
-	int stop = 0, retval = 0;
-
-	num = 0;
-	if (!func)
-		d = (char *) arg;
-	else
-		d = NULL;
-
-	if (fmt == NULL)
-		fmt = "(fmt null)\n";
-
-	if (radix < 2 || radix > 36)
-		radix = 10;
-
-	for (;;) {
-		padc = ' ';
-		width = 0;
-		while ((ch = (unsigned char)*fmt++) != '%' || stop) {
-			if (ch == '\0')
-				return (retval);
-			PCHAR(ch);
-		}
-		percent = fmt - 1;
-		qflag = 0; lflag = 0; ladjust = 0; sharpflag = 0; neg = 0;
-		sign = 0; dot = 0; dwidth = 0; upper = 0;
-		cflag = 0; hflag = 0; jflag = 0; tflag = 0; zflag = 0;
-reswitch:	switch (ch = (unsigned char)*fmt++) {
-		case '.':
-			dot = 1;
-			goto reswitch;
-		case '#':
-			sharpflag = 1;
-			goto reswitch;
-		case '+':
-			sign = 1;
-			goto reswitch;
-		case '-':
-			ladjust = 1;
-			goto reswitch;
-		case '%':
-			PCHAR(ch);
-			break;
-		case '*':
-			if (!dot) {
-				width = va_arg(ap, int);
-				if (width < 0) {
-					ladjust = !ladjust;
-					width = -width;
-				}
-			} else {
-				dwidth = va_arg(ap, int);
-			}
-			goto reswitch;
-		case '0':
-			if (!dot) {
-				padc = '0';
-				goto reswitch;
-			}
-		case '1': case '2': case '3': case '4':
-		case '5': case '6': case '7': case '8': case '9':
-				for (n = 0;; ++fmt) {
-					n = n * 10 + ch - '0';
-					ch = *fmt;
-					if (ch < '0' || ch > '9')
-						break;
-				}
-			if (dot)
-				dwidth = n;
-			else
-				width = n;
-			goto reswitch;
-		case 'b':
-			num = (unsigned int)va_arg(ap, int);
-			p = va_arg(ap, char *);
-			for (q = ksprintn(nbuf, num, *p++, NULL, 0); *q;)
-				PCHAR(*q--);
-
-			if (num == 0)
-				break;
-
-			for (tmp = 0; *p;) {
-				n = *p++;
-				if (num & (1 << (n - 1))) {
-					PCHAR(tmp ? ',' : '<');
-					for (; (n = *p) > ' '; ++p)
-						PCHAR(n);
-					tmp = 1;
-				} else
-					for (; *p > ' '; ++p)
-						continue;
-			}
-			if (tmp)
-				PCHAR('>');
-			break;
-		case 'c':
-			PCHAR(va_arg(ap, int));
-			break;
-		case 'D':
-			up = va_arg(ap, unsigned char *);
-			p = va_arg(ap, char *);
-			if (!width)
-				width = 16;
-			while(width--) {
-				PCHAR(hex2ascii(*up >> 4));
-				PCHAR(hex2ascii(*up & 0x0f));
-				up++;
-				if (width)
-					for (q=p;*q;q++)
-						PCHAR(*q);
-			}
-			break;
-		case 'd':
-		case 'i':
-			base = 10;
-			sign = 1;
-			goto handle_sign;
-		case 'h':
-			if (hflag) {
-				hflag = 0;
-				cflag = 1;
-			} else
-				hflag = 1;
-			goto reswitch;
-		case 'j':
-			jflag = 1;
-			goto reswitch;
-		case 'l':
-			if (lflag) {
-				lflag = 0;
-				qflag = 1;
-			} else
-				lflag = 1;
-			goto reswitch;
-		case 'n':
-			if (jflag)
-				*(va_arg(ap, intmax_t *)) = retval;
-			else if (qflag)
-				*(va_arg(ap, int64_t *)) = retval;
-			else if (lflag)
-				*(va_arg(ap, long *)) = retval;
-			else if (zflag)
-				*(va_arg(ap, size_t *)) = retval;
-			else if (hflag)
-				*(va_arg(ap, short *)) = retval;
-			else if (cflag)
-				*(va_arg(ap, char *)) = retval;
-			else
-				*(va_arg(ap, int *)) = retval;
-			break;
-		case 'o':
-			base = 8;
-			goto handle_nosign;
-		case 'p':
-			base = 16;
-			sharpflag = (width == 0);
-			sign = 0;
-			num = (uintptr_t)va_arg(ap, void *);
-			goto number;
-		case 'q':
-			qflag = 1;
-			goto reswitch;
-		case 'r':
-			base = radix;
-			if (sign)
-				goto handle_sign;
-			goto handle_nosign;
-		case 's':
-			p = va_arg(ap, char *);
-			if (p == NULL)
-				p = "(null)";
-			if (!dot)
-				n = (int)strlen (p);
-			else
-				for (n = 0; n < dwidth && p[n]; n++)
-					continue;
-
-			width -= n;
-
-			if (!ladjust && width > 0)
-				while (width--)
-					PCHAR(padc);
-			while (n--)
-				PCHAR(*p++);
-			if (ladjust && width > 0)
-				while (width--)
-					PCHAR(padc);
-			break;
-		case 't':
-			tflag = 1;
-			goto reswitch;
-		case 'u':
-			base = 10;
-			goto handle_nosign;
-		case 'X':
-			upper = 1;
-		case 'x':
-			base = 16;
-			goto handle_nosign;
-		case 'y':
-			base = 16;
-			sign = 1;
-			goto handle_sign;
-		case 'z':
-			zflag = 1;
-			goto reswitch;
-handle_nosign:
-			sign = 0;
-			if (jflag)
-				num = va_arg(ap, uintmax_t);
-			else if (qflag)
-				num = va_arg(ap, uint64_t);
-			else if (tflag)
-				num = va_arg(ap, ptrdiff_t);
-			else if (lflag)
-				num = va_arg(ap, unsigned long);
-			else if (zflag)
-				num = va_arg(ap, size_t);
-			else if (hflag)
-				num = (unsigned short)va_arg(ap, int);
-			else if (cflag)
-				num = (unsigned char)va_arg(ap, int);
-			else
-				num = va_arg(ap, unsigned int);
-			goto number;
-handle_sign:
-			if (jflag)
-				num = va_arg(ap, intmax_t);
-			else if (qflag)
-				num = va_arg(ap, int64_t);
-			else if (tflag)
-				num = va_arg(ap, ptrdiff_t);
-			else if (lflag)
-				num = va_arg(ap, long);
-			else if (zflag)
-				num = va_arg(ap, ssize_t);
-			else if (hflag)
-				num = (short)va_arg(ap, int);
-			else if (cflag)
-				num = (char)va_arg(ap, int);
-			else
-				num = va_arg(ap, int);
-number:
-			if (sign && (intmax_t)num < 0) {
-				neg = 1;
-				num = -(intmax_t)num;
-			}
-			p = ksprintn(nbuf, num, base, &n, upper);
-			tmp = 0;
-			if (sharpflag && num != 0) {
-				if (base == 8)
-					tmp++;
-				else if (base == 16)
-					tmp += 2;
-			}
-			if (neg)
-				tmp++;
-
-			if (!ladjust && padc == '0')
-				dwidth = width - tmp;
-			width -= tmp + imax(dwidth, n);
-			dwidth -= n;
-			if (!ladjust)
-				while (width-- > 0)
-					PCHAR(' ');
-			if (neg)
-				PCHAR('-');
-			if (sharpflag && num != 0) {
-				if (base == 8) {
-					PCHAR('0');
-				} else if (base == 16) {
-					PCHAR('0');
-					PCHAR('x');
-				}
-			}
-			while (dwidth-- > 0)
-				PCHAR('0');
-
-			while (*p)
-				PCHAR(*p--);
-
-			if (ladjust)
-				while (width-- > 0)
-					PCHAR(' ');
-
-			break;
-		default:
-			while (percent < fmt)
-				PCHAR(*percent++);
-			/*
-			 * Since we ignore an formatting argument it is no
-			 * longer safe to obey the remaining formatting
-			 * arguments as the arguments will no longer match
-			 * the format specs.
-			 */
-			stop = 1;
-			break;
-		}
-	}
-#undef PCHAR
-}
 #else /* defined(USE_ELF) */
 #error not supported
 #endif
diff --git a/addr2line.h b/addr2line.h
index f09b665800..ff8e476b92 100644
--- a/addr2line.h
+++ b/addr2line.h
@@ -12,8 +12,10 @@
 
 #if (defined(USE_ELF) || defined(HAVE_MACH_O_LOADER_H))
 
+#include <stdio.h>
+
 void
-rb_dump_backtrace_with_lines(int num_traces, void **traces);
+rb_dump_backtrace_with_lines(int num_traces, void **traces, FILE *errout);
 
 #endif /* USE_ELF */
 
diff --git a/array.c b/array.c
index 514eb5be77..db4c2c4802 100644
--- a/array.c
+++ b/array.c
@@ -27,8 +27,11 @@
 #include "probes.h"
 #include "ruby/encoding.h"
 #include "ruby/st.h"
+#include "ruby/thread.h"
 #include "ruby/util.h"
-#include "transient_heap.h"
+#include "ruby/ractor.h"
+#include "shape.h"
+#include "vm_core.h"
 #include "builtin.h"
 
 #if !ARRAY_DEBUG
@@ -38,22 +41,18 @@
 #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).
- * if USE_RVARGC
  * 3-9: RARRAY_EMBED_LEN
  *          The length of the array when RARRAY_EMBED_FLAG is set.
- * else
- * 3-4: RARRAY_EMBED_LEN
- *          The length of the array when RARRAY_EMBED_FLAG is set.
- * endif
  * 12:  RARRAY_SHARED_ROOT_FLAG
  *          The array is a shared root that does reference counting. The buffer
  *          this array points to is owned by this array but may be pointed to
@@ -63,8 +62,6 @@ VALUE rb_cArray;
  *                they cannot be modified. Not updating the reference count
  *                improves copy-on-write performance. Their reference count is
  *                assumed to be infinity.
- * 13:  RARRAY_TRANSIENT_FLAG
- *          The buffer of the array is allocated on the transient heap.
  * 14:  RARRAY_PTR_IN_USE_FLAG
  *          The buffer of the array is in use. This is only used during
  *          debugging.
@@ -84,48 +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); \
-    RARY_TRANSIENT_UNSET(a); \
     ary_verify(a); \
 } while (0)
 
 #define FL_UNSET_EMBED(ary) FL_UNSET((ary), RARRAY_EMBED_FLAG|RARRAY_EMBED_LEN_MASK)
 #define FL_SET_SHARED(ary) do { \
-    assert(!ARY_EMBED_P(ary)); \
+    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 { \
@@ -135,15 +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)); \
     } \
@@ -154,32 +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)); \
-    assert(!RARRAY_TRANSIENT_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);
 }
@@ -188,29 +187,23 @@ ARY_SET(VALUE a, long i, VALUE v)
 static long
 ary_embed_capa(VALUE ary)
 {
-#if USE_RVARGC
     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);
-#else
-    return RARRAY_EMBED_LEN_MAX;
-#endif
 }
 
 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
 ary_embeddable_p(long capa)
 {
-#if USE_RVARGC
     return rb_gc_size_allocatable_p(ary_embed_size(capa));
-#else
-    return capa <= RARRAY_EMBED_LEN_MAX;
-#endif
 }
 
 bool
@@ -251,25 +244,23 @@ 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_TRANSIENT(root);
+        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(!RARRAY_TRANSIENT_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_TRANSIENT(ary);
+        const VALUE *ptr = RARRAY_CONST_PTR(ary);
         long i, len = RARRAY_LEN(ary);
         volatile VALUE v;
         if (len > 1) len = 1; /* check only HEAD */
@@ -277,25 +268,10 @@ ary_verify_(VALUE ary, const char *file, int line)
             v = ptr[i]; /* access check */
         }
         v = v;
-#endif
     }
 
-#if USE_TRANSIENT_HEAP
-    if (RARRAY_TRANSIENT_P(ary)) {
-        assert(rb_transient_heap_managed_ptr_p(RARRAY_CONST_PTR_TRANSIENT(ary)));
-    }
-#endif
-
-    rb_transient_heap_verify();
-
     return ary;
 }
-
-void
-rb_ary_verify(VALUE ary)
-{
-    ary_verify(ary);
-}
 #else
 #define ary_verify(ary) ((void)0)
 #endif
@@ -306,7 +282,7 @@ rb_ary_ptr_use_start(VALUE ary)
 #if ARRAY_DEBUG
     FL_SET_RAW(ary, RARRAY_PTR_IN_USE_FLAG);
 #endif
-    return (VALUE *)RARRAY_CONST_PTR_TRANSIENT(ary);
+    return (VALUE *)RARRAY_CONST_PTR(ary);
 }
 
 void
@@ -328,7 +304,7 @@ rb_mem_clear(VALUE *mem, long size)
 static void
 ary_mem_clear(VALUE ary, long beg, long size)
 {
-    RARRAY_PTR_USE_TRANSIENT(ary, ptr, {
+    RARRAY_PTR_USE(ary, ptr, {
         rb_mem_clear(ptr + beg, size);
     });
 }
@@ -344,7 +320,7 @@ memfill(register VALUE *mem, register long size, register VALUE val)
 static void
 ary_memfill(VALUE ary, long beg, long size, VALUE val)
 {
-    RARRAY_PTR_USE_TRANSIENT(ary, ptr, {
+    RARRAY_PTR_USE(ary, ptr, {
         memfill(ptr + beg, size, val);
         RB_OBJ_WRITTEN(ary, Qundef, val);
     });
@@ -353,17 +329,17 @@ 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);
-        RARRAY_PTR_USE_TRANSIENT(ary, ptr, {
+        RARRAY_PTR_USE(ary, ptr, {
             MEMCPY(ptr+beg, argv, VALUE, argc);
         });
     }
     else {
         int i;
-        RARRAY_PTR_USE_TRANSIENT(ary, ptr, {
+        RARRAY_PTR_USE(ary, ptr, {
             for (i=0; i<argc; i++) {
                 RB_OBJ_WRITE(buff_owner_ary, &ptr[i+beg], argv[i]);
             }
@@ -378,158 +354,63 @@ ary_memcpy(VALUE ary, long beg, long argc, const VALUE *argv)
 }
 
 static VALUE *
-ary_heap_alloc(VALUE ary, size_t capa)
+ary_heap_alloc_buffer(size_t capa)
 {
-    VALUE *ptr = rb_transient_heap_alloc(ary, sizeof(VALUE) * capa);
-
-    if (ptr != NULL) {
-        RARY_TRANSIENT_SET(ary);
-    }
-    else {
-        RARY_TRANSIENT_UNSET(ary);
-        ptr = ALLOC_N(VALUE, capa);
-    }
-
-    return ptr;
+    return ALLOC_N(VALUE, capa);
 }
 
 static void
 ary_heap_free_ptr(VALUE ary, const VALUE *ptr, long size)
 {
-    if (RARRAY_TRANSIENT_P(ary)) {
-        /* ignore it */
-    }
-    else {
-        ruby_sized_xfree((void *)ptr, size);
-    }
+    ruby_xfree_sized((void *)ptr, size);
 }
 
 static void
 ary_heap_free(VALUE ary)
 {
-    if (RARRAY_TRANSIENT_P(ary)) {
-        RARY_TRANSIENT_UNSET(ary);
-    }
-    else {
-        ary_heap_free_ptr(ary, ARY_HEAP_PTR(ary), ARY_HEAP_SIZE(ary));
-    }
+    ary_heap_free_ptr(ary, ARY_HEAP_PTR(ary), ARY_HEAP_SIZE(ary));
 }
 
 static size_t
 ary_heap_realloc(VALUE ary, size_t new_capa)
 {
-    size_t alloc_capa = new_capa;
-    size_t old_capa = ARY_HEAP_CAPA(ary);
-
-    if (RARRAY_TRANSIENT_P(ary)) {
-        if (new_capa <= old_capa) {
-            /* do nothing */
-            alloc_capa = old_capa;
-        }
-        else {
-            VALUE *new_ptr = rb_transient_heap_alloc(ary, sizeof(VALUE) * new_capa);
-
-            if (new_ptr == NULL) {
-                new_ptr = ALLOC_N(VALUE, new_capa);
-                RARY_TRANSIENT_UNSET(ary);
-            }
-
-            MEMCPY(new_ptr, ARY_HEAP_PTR(ary), VALUE, old_capa);
-            ARY_SET_PTR(ary, new_ptr);
-        }
-    }
-    else {
-        SIZED_REALLOC_N(RARRAY(ary)->as.heap.ptr, VALUE, new_capa, old_capa);
-    }
-    ary_verify(ary);
-
-    return alloc_capa;
-}
-
-#if USE_TRANSIENT_HEAP
-static inline void
-rb_ary_transient_heap_evacuate_(VALUE ary, int transient, int promote)
-{
-    if (transient) {
-        assert(!ARY_SHARED_ROOT_P(ary));
-
-        VALUE *new_ptr;
-        const VALUE *old_ptr = ARY_HEAP_PTR(ary);
-        long capa = ARY_HEAP_CAPA(ary);
-
-        assert(ARY_OWNS_HEAP_P(ary));
-        assert(RARRAY_TRANSIENT_P(ary));
-        assert(!ARY_PTR_USING_P(ary));
-
-        if (promote) {
-            new_ptr = ALLOC_N(VALUE, capa);
-            RARY_TRANSIENT_UNSET(ary);
-        }
-        else {
-            new_ptr = ary_heap_alloc(ary, capa);
-        }
-
-        MEMCPY(new_ptr, old_ptr, VALUE, capa);
-        /* do not use ARY_SET_PTR() because they assert !frozen */
-        RARRAY(ary)->as.heap.ptr = new_ptr;
-    }
-
+    RUBY_ASSERT(!OBJ_FROZEN(ary));
+    SIZED_REALLOC_N(RARRAY(ary)->as.heap.ptr, VALUE, new_capa, ARY_HEAP_CAPA(ary));
     ary_verify(ary);
-}
 
-void
-rb_ary_transient_heap_evacuate(VALUE ary, int promote)
-{
-    rb_ary_transient_heap_evacuate_(ary, RARRAY_TRANSIENT_P(ary), promote);
+    return new_capa;
 }
 
 void
-rb_ary_detransient(VALUE ary)
-{
-    assert(RARRAY_TRANSIENT_P(ary));
-    rb_ary_transient_heap_evacuate_(ary, TRUE, TRUE);
-}
-#else
-void
-rb_ary_detransient(VALUE ary)
-{
-    /* do nothing */
-}
-#endif
-
-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);
-        bool was_transient = RARRAY_TRANSIENT_P(ary);
+        long capa = ARY_HEAP_CAPA(ary);
 
-        // FL_SET_EMBED also unsets the transient flag
         FL_SET_EMBED(ary);
         ARY_SET_EMBED_LEN(ary, len);
 
         MEMCPY((void *)ARY_EMBED_PTR(ary), (void *)buf, VALUE, len);
 
-        if (!was_transient) {
-            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(ary, capacity);
+            VALUE *ptr = ary_heap_alloc_buffer(capacity);
 
             MEMCPY(ptr, ARY_EMBED_PTR(ary), VALUE, len);
             FL_UNSET_EMBED(ary);
@@ -549,7 +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);
@@ -564,9 +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);
 }
@@ -624,7 +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;
@@ -633,9 +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);
@@ -647,6 +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);
 }
@@ -669,22 +555,22 @@ rb_ary_cancel_sharing(VALUE ary)
             ARY_SET_EMBED_LEN(ary, len);
         }
         else if (ARY_SHARED_ROOT_OCCUPIED(shared_root) && len > ((shared_len = RARRAY_LEN(shared_root))>>1)) {
-            long shift = RARRAY_CONST_PTR_TRANSIENT(ary) - RARRAY_CONST_PTR_TRANSIENT(shared_root);
+            long shift = RARRAY_CONST_PTR(ary) - RARRAY_CONST_PTR(shared_root);
             FL_UNSET_SHARED(ary);
-            ARY_SET_PTR(ary, RARRAY_CONST_PTR_TRANSIENT(shared_root));
+            ARY_SET_PTR(ary, RARRAY_CONST_PTR(shared_root));
             ARY_SET_CAPA(ary, shared_len);
-            RARRAY_PTR_USE_TRANSIENT(ary, ptr, {
+            RARRAY_PTR_USE(ary, ptr, {
                 MEMMOVE(ptr, ptr+shift, VALUE, len);
             });
             FL_SET_EMBED(shared_root);
             rb_ary_decrement_share(shared_root);
         }
         else {
-            VALUE *ptr = ary_heap_alloc(ary, len);
+            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);
@@ -713,7 +599,7 @@ ary_ensure_room_for_push(VALUE ary, long add_len)
         if (new_len > ary_embed_capa(ary)) {
             VALUE shared_root = ARY_SHARED_ROOT(ary);
             if (ARY_SHARED_ROOT_OCCUPIED(shared_root)) {
-                if (ARY_HEAP_PTR(ary) - RARRAY_CONST_PTR_TRANSIENT(shared_root) + new_len <= RARRAY_LEN(shared_root)) {
+                if (ARY_HEAP_PTR(ary) - RARRAY_CONST_PTR(shared_root) + new_len <= RARRAY_LEN(shared_root)) {
                     rb_ary_modify_check(ary);
 
                     ary_verify(ary);
@@ -749,21 +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);
 }
 
@@ -790,26 +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));
-#if !USE_RVARGC
-    assert(size <= sizeof(struct RArray));
-#endif
-    RVARGC_NEWOBJ_OF(ary, struct RArray, klass,
-                     T_ARRAY | RARRAY_EMBED_FLAG | (RGENGC_WB_PROTECTED_ARRAY ? FL_WB_PROTECTED : 0),
-                     size);
-    /* 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)
 {
-    RVARGC_NEWOBJ_OF(ary, struct RArray, klass,
-                     T_ARRAY | (RGENGC_WB_PROTECTED_ARRAY ? FL_WB_PROTECTED : 0),
-                     sizeof(struct RArray));
+    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;
 }
 
@@ -823,7 +717,9 @@ empty_ary_alloc(VALUE klass)
 static VALUE
 ary_new(VALUE klass, long capa)
 {
-    VALUE ary,*ptr;
+    RUBY_ASSERT(ruby_thread_has_gvl_p());
+
+    VALUE ary;
 
     if (capa < 0) {
         rb_raise(rb_eArgError, "negative array size (or size too big)");
@@ -840,10 +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));
 
-        ptr = ary_heap_alloc(ary, capa);
-        ARY_SET_PTR(ary, ptr);
+        ARY_SET_PTR(ary, ary_heap_alloc_buffer(capa));
         ARY_SET_HEAP_LEN(ary, 0);
     }
 
@@ -881,7 +776,7 @@ VALUE
     return ary;
 }
 
-MJIT_FUNC_EXPORTED VALUE
+VALUE
 rb_ary_tmp_new_from_values(VALUE klass, long n, const VALUE *elts)
 {
     VALUE ary;
@@ -905,33 +800,28 @@ 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));
-#if !USE_RVARGC
-    assert(size <= sizeof(struct RArray));
-#endif
-    RB_RVARGC_EC_NEWOBJ_OF(ec, ary, struct RArray, klass,
-                           T_ARRAY | RARRAY_EMBED_FLAG | (RGENGC_WB_PROTECTED_ARRAY ? FL_WB_PROTECTED : 0),
-                           size);
-    /* 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)
 {
-    RB_RVARGC_EC_NEWOBJ_OF(ec, ary, struct RArray, klass,
-                           T_ARRAY | (RGENGC_WB_PROTECTED_ARRAY ? FL_WB_PROTECTED : 0),
-                           sizeof(struct RArray));
-    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
 ec_ary_new(rb_execution_context_t *ec, VALUE klass, long capa)
 {
-    VALUE ary,*ptr;
+    VALUE ary;
 
     if (capa < 0) {
         rb_raise(rb_eArgError, "negative array size (or size too big)");
@@ -948,10 +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));
 
-        ptr = ary_heap_alloc(ary, capa);
-        ARY_SET_PTR(ary, ptr);
+        ARY_SET_PTR(ary, ary_heap_alloc_buffer(capa));
         ARY_SET_HEAP_LEN(ary, 0);
     }
 
@@ -976,7 +865,6 @@ VALUE
 rb_ary_hidden_new(long capa)
 {
     VALUE ary = ary_new(0, capa);
-    rb_ary_transient_heap_evacuate(ary, TRUE);
     return ary;
 }
 
@@ -999,13 +887,8 @@ rb_ary_free(VALUE ary)
             RB_DEBUG_COUNTER_INC(obj_ary_extracapa);
         }
 
-        if (RARRAY_TRANSIENT_P(ary)) {
-            RB_DEBUG_COUNTER_INC(obj_ary_transient);
-        }
-        else {
-            RB_DEBUG_COUNTER_INC(obj_ary_ptr);
-            ary_heap_free(ary);
-        }
+        RB_DEBUG_COUNTER_INC(obj_ary_ptr);
+        ary_heap_free(ary);
     }
     else {
         RB_DEBUG_COUNTER_INC(obj_ary_embed);
@@ -1019,7 +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)) {
@@ -1033,7 +942,6 @@ rb_ary_memsize(VALUE ary)
 static VALUE
 ary_make_shared(VALUE ary)
 {
-    assert(USE_RVARGC || !ARY_EMBED_P(ary));
     ary_verify(ary);
 
     if (ARY_SHARED_P(ary)) {
@@ -1043,15 +951,9 @@ ary_make_shared(VALUE ary)
         return ary;
     }
     else if (OBJ_FROZEN(ary)) {
-        if (!ARY_EMBED_P(ary)) {
-            rb_ary_transient_heap_evacuate(ary, TRUE);
-            ary_shrink_capa(ary);
-        }
         return ary;
     }
     else {
-        rb_ary_transient_heap_evacuate(ary, TRUE);
-
         long capa = ARY_CAPA(ary);
         long len = RARRAY_LEN(ary);
 
@@ -1061,9 +963,7 @@ ary_make_shared(VALUE ary)
         FL_SET_SHARED_ROOT(shared);
 
         if (ARY_EMBED_P(ary)) {
-            /* Cannot use ary_heap_alloc because we don't want to allocate
-             * on the transient heap. */
-            VALUE *ptr = ALLOC_N(VALUE, capa);
+            VALUE *ptr = ary_heap_alloc_buffer(capa);
             ARY_SET_PTR(shared, ptr);
             ary_memcpy(shared, 0, len, RARRAY_CONST_PTR(ary));
 
@@ -1093,9 +993,9 @@ 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_TRANSIENT(ary));
+        ary_memcpy(subst, 0, len, RARRAY_CONST_PTR(ary));
         ARY_SET_EMBED_LEN(subst, len);
         return subst;
     }
@@ -1123,7 +1023,7 @@ rb_check_array_type(VALUE ary)
     return rb_check_convert_type_with_id(ary, T_ARRAY, "Array", idTo_ary);
 }
 
-MJIT_FUNC_EXPORTED VALUE
+VALUE
 rb_check_to_array(VALUE ary)
 {
     return rb_check_convert_type_with_id(ary, T_ARRAY, "Array", idTo_a);
@@ -1139,14 +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
@@ -1183,48 +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 integer argument given, returns a new array containing
+ *  that many instances of the given +default_value+:
+ *
+ *    Array.new(0)    # => []
+ *    Array.new(3)    # => [nil, nil, nil]
+ *    Array.new(2, 3) # => [3, 3]
  *
- *  With no block and a single \Integer argument +size+,
- *  returns a new \Array of the given size
- *  whose elements are all +nil+:
+ *  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)
- *    a # => [nil, nil, nil]
+ *    Array.new(3)  {|index| "Element #{index}" } # => ["Element 0", "Element 1", "Element 2"]
  *
- *  With no block and arguments +size+ and +default_value+,
- *  returns an \Array of the given size;
- *  each element is that same +default_value+:
+ *  A common pitfall for new Rubyists is providing an expression as +default_value+:
  *
- *    a = Array.new(3, 'x')
- *    a # => ['x', 'x', 'x']
+ *    array = Array.new(2, {})
+ *    array # => [{}, {}]
+ *    array[0][:a] = 1
+ *    array # => [{a: 1}, {a: 1}], as array[0] and array[1] are same object
  *
- *  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:
+ *  If you want the elements of the array to be distinct, you should pass a block:
  *
- *    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}, {}], as array[0] and array[1] are different objects
  *
- *  Raises ArgumentError if +size+ is negative.
+ *  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.
  *
- *  With a block and no argument,
- *  or a single argument +0+,
- *  ignores the block and returns a new empty \Array.
+ *  Related: see {Methods for Creating an Array}[rdoc-ref:Array@Methods+for+Creating+an+Array].
  */
 
 static VALUE
@@ -1236,8 +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");
         }
@@ -1282,11 +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[ 1, 'a', /^A/ ]    # => [1, "a", /^A/]
- *   [ 1, 'a', /^A/ ]         # => [1, "a", /^A/]
+ *   Array[1, 'a', /^A/]    # => [1, "a", /^A/]
+ *   Array[]                # => []
+ *   Array.[](1, 'a', /^A/) # => [1, "a", /^A/]
+ *
+ * Related: see {Methods for Creating an Array}[rdoc-ref:Array@Methods+for+Creating+an+Array].
  */
 
 static VALUE
@@ -1334,25 +1243,26 @@ 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));
-
-    const size_t rarray_embed_capa_max = (sizeof(struct RArray) - offsetof(struct RArray, as.ary)) / sizeof(VALUE);
+    RUBY_ASSERT(offset >= 0);
+    RUBY_ASSERT(len >= 0);
+    RUBY_ASSERT(offset+len <= RARRAY_LEN(ary));
 
-    if ((size_t)len <= rarray_embed_capa_max && ary_embeddable_p(len)) {
-        VALUE result = ary_alloc_embed(klass, len);
-        ary_memcpy(result, 0, len, RARRAY_CONST_PTR_TRANSIENT(ary) + offset);
+    VALUE result = ary_alloc_heap(klass);
+    size_t embed_capa = ary_embed_capa(result);
+    if ((size_t)len <= embed_capa) {
+        FL_SET_EMBED(result);
+        ary_memcpy(result, 0, len, RARRAY_CONST_PTR(ary) + offset);
         ARY_SET_EMBED_LEN(result, len);
-        return result;
     }
     else {
         VALUE shared = ary_make_shared(ary);
 
-        VALUE result = ary_alloc_heap(klass);
-        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_TRANSIENT(ary));
+        ARY_SET_PTR(result, RARRAY_CONST_PTR(ary));
         ARY_SET_LEN(result, RARRAY_LEN(ary));
         rb_ary_set_shared(result, shared);
 
@@ -1360,25 +1270,27 @@ ary_make_partial(VALUE ary, VALUE klass, long offset, long len)
         ARY_SET_LEN(result, len);
 
         ary_verify(shared);
-        ary_verify(result);
-        return result;
     }
+
+    ary_verify(result);
+    return result;
 }
 
 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_TRANSIENT(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;
@@ -1396,6 +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;
@@ -1403,7 +1317,9 @@ ary_make_partial_step(VALUE ary, VALUE klass, long offset, long len, long step)
         ARY_SET_EMBED_LEN(result, len);
     }
     else {
-        RARRAY_PTR_USE_TRANSIENT(result, ptr, {
+        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]);
                 j += step;
@@ -1428,20 +1344,11 @@ enum ary_take_pos_flags
 };
 
 static VALUE
-ary_take_first_or_last(int argc, const VALUE *argv, VALUE ary, enum ary_take_pos_flags last)
+ary_take_first_or_last_n(VALUE ary, long n, enum ary_take_pos_flags last)
 {
-    long n;
-    long len;
+    long len = RARRAY_LEN(ary);
     long offset = 0;
 
-    argc = rb_check_arity(argc, 0, 1);
-    /* the case optional argument is omitted should be handled in
-     * callers of this function.  if another arity case is added,
-     * this arity check needs to rewrite. */
-    RUBY_ASSERT_ALWAYS(argc == 1);
-
-    n = NUM2LONG(argv[0]);
-    len = RARRAY_LEN(ary);
     if (n > len) {
         n = len;
     }
@@ -1454,21 +1361,30 @@ ary_take_first_or_last(int argc, const VALUE *argv, VALUE ary, enum ary_take_pos
     return ary_make_partial(ary, rb_cArray, offset, n);
 }
 
+static VALUE
+ary_take_first_or_last(int argc, const VALUE *argv, VALUE ary, enum ary_take_pos_flags last)
+{
+    argc = rb_check_arity(argc, 0, 1);
+    /* the case optional argument is omitted should be handled in
+     * callers of this function.  if another arity case is added,
+     * this arity check needs to rewrite. */
+    RUBY_ASSERT_ALWAYS(argc == 1);
+    return ary_take_first_or_last_n(ary, NUM2LONG(argv[0]), last);
+}
+
 /*
  *  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
@@ -1476,7 +1392,7 @@ rb_ary_push(VALUE ary, VALUE item)
 {
     long idx = RARRAY_LEN((ary_verify(ary), ary));
     VALUE target_ary = ary_ensure_room_for_push(ary, 1);
-    RARRAY_PTR_USE_TRANSIENT(ary, ptr, {
+    RARRAY_PTR_USE(ary, ptr, {
         RB_OBJ_WRITE(target_ary, &ptr[idx], item);
     });
     ARY_SET_LEN(ary, idx + 1);
@@ -1496,24 +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]]
- *
- *  Array#append is an alias for Array#push.
- *
- *  Related: #pop, #shift, #unshift.
+ *  Related: see {Methods for Assigning}[rdoc-ref:Array@Methods+for+Assigning].
  */
 
 static VALUE
@@ -1535,41 +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"]
- *
- *  Returns +nil+ if the array is empty.
+ *    a.pop  # => 2
+ *    a      # => [:foo, "bar"]
+ *    [].pop # => nil
  *
- *  When a non-negative \Integer argument +n+ is given and is in range,
+ *  With non-negative integer argument +count+ given,
+ *  returns a new array containing the trailing +count+ elements of +self+, as available:
  *
- *  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
@@ -1608,35 +1521,40 @@ rb_ary_shift(VALUE ary)
 
 /*
  *  call-seq:
- *     array.shift -> object or nil
- *     array.shift(n) -> new_array
+ *    shift -> object or nil
+ *    shift(count) -> new_array or nil
  *
- *  Removes and returns leading elements.
+ *  Removes and returns leading elements from +self+.
  *
- *  When no argument is given, removes and returns the first element:
+ *  With no argument, removes and returns one element, if available,
+ *  or +nil+ otherwise:
  *
- *    a = [:foo, 'bar', 2]
- *    a.shift # => :foo
- *    a # => ['bar', 2]
- *
- *  Returns +nil+ if +self+ is empty.
- *
- *  When positive \Integer argument +n+ is given, removes the first +n+ elements;
- *  returns those elements in a new \Array:
+ *    a = [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
@@ -1657,7 +1575,7 @@ rb_ary_shift_m(int argc, VALUE *argv, VALUE ary)
     return result;
 }
 
-MJIT_FUNC_EXPORTED VALUE
+VALUE
 rb_ary_behead(VALUE ary, long n)
 {
     if (n <= 0) {
@@ -1668,7 +1586,7 @@ rb_ary_behead(VALUE ary, long n)
 
     if (!ARY_SHARED_P(ary)) {
         if (ARY_EMBED_P(ary) || RARRAY_LEN(ary) < ARY_DEFAULT_SIZE) {
-            RARRAY_PTR_USE_TRANSIENT(ary, ptr, {
+            RARRAY_PTR_USE(ary, ptr, {
                 MEMMOVE(ptr, ptr + n, VALUE, RARRAY_LEN(ary) - n);
             }); /* WB: no new reference */
             ARY_INCREASE_LEN(ary, -n);
@@ -1701,7 +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);
@@ -1729,12 +1647,12 @@ ary_modify_for_unshift(VALUE ary, int argc)
         capa = ARY_CAPA(ary);
         ary_make_shared(ary);
 
-        head = sharedp = RARRAY_CONST_PTR_TRANSIENT(ary);
+        head = sharedp = RARRAY_CONST_PTR(ary);
         return make_room_for_unshift(ary, head, (void *)sharedp, argc, capa, len);
     }
     else {
         /* sliding items */
-        RARRAY_PTR_USE_TRANSIENT(ary, ptr, {
+        RARRAY_PTR_USE(ary, ptr, {
             MEMMOVE(ptr + argc, ptr, VALUE, len);
         });
 
@@ -1766,8 +1684,8 @@ ary_ensure_room_for_unshift(VALUE ary, int argc)
             return ary_modify_for_unshift(ary, argc);
         }
         else {
-            const VALUE * head = RARRAY_CONST_PTR_TRANSIENT(ary);
-            void *sharedp = (void *)RARRAY_CONST_PTR_TRANSIENT(shared_root);
+            const VALUE * head = RARRAY_CONST_PTR(ary);
+            void *sharedp = (void *)RARRAY_CONST_PTR(shared_root);
 
             rb_ary_modify_check(ary);
             return make_room_for_unshift(ary, head, sharedp, argc, capa, len);
@@ -1777,19 +1695,19 @@ 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]
  *
- *  Array#prepend is an alias for Array#unshift.
- *
- *  Related: #push, #pop, #shift.
+ *  Related: Array#shift;
+ *  see also {Methods for Assigning}[rdoc-ref:Array@Methods+for+Assigning].
  */
 
-static VALUE
+VALUE
 rb_ary_unshift_m(int argc, VALUE *argv, VALUE ary)
 {
     long len = RARRAY_LEN(ary);
@@ -1809,7 +1727,7 @@ rb_ary_unshift_m(int argc, VALUE *argv, VALUE ary)
 VALUE
 rb_ary_unshift(VALUE ary, VALUE item)
 {
-    return rb_ary_unshift_m(1,&item,ary);
+    return rb_ary_unshift_m(1, &item, ary);
 }
 
 /* faster version - use this if you don't need to treat negative offset */
@@ -1862,25 +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
@@ -1888,35 +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:
+ *  When a single Range argument +range+ is given,
+ *  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:
  *
@@ -1940,7 +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']
@@ -1962,7 +1893,7 @@ static VALUE rb_ary_aref2(VALUE ary, VALUE b, VALUE e);
  *    # Raises TypeError (no implicit conversion of Symbol into Integer):
  *    a[:foo]
  *
- *  Array#slice is an alias for Array#[].
+ *  Related: see {Methods for Fetching}[rdoc-ref:Array@Methods+for+Fetching].
  */
 
 VALUE
@@ -1986,7 +1917,7 @@ rb_ary_aref2(VALUE ary, VALUE b, VALUE e)
     return rb_ary_subseq(ary, beg, len);
 }
 
-MJIT_FUNC_EXPORTED VALUE
+VALUE
 rb_ary_aref1(VALUE ary, VALUE arg)
 {
     long beg, len, step;
@@ -2010,13 +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
@@ -2025,39 +1969,7 @@ rb_ary_at(VALUE ary, VALUE pos)
     return rb_ary_entry(ary, NUM2LONG(pos));
 }
 
-/*
- *  call-seq:
- *    array.first -> object or nil
- *    array.first(n) -> new_array
- *
- *  Returns elements from +self+; does not modify +self+.
- *
- *  When no argument is given, returns the first element:
- *
- *    a = [:foo, 'bar', 2]
- *    a.first # => :foo
- *    a # => [:foo, "bar", 2]
- *
- *  If +self+ is empty, returns +nil+.
- *
- *  When non-negative \Integer argument +n+ is given,
- *  returns the first +n+ elements in a new \Array:
- *
- *    a = [:foo, 'bar', 2]
- *    a.first(2) # => [:foo, "bar"]
- *
- *  If <tt>n >= array.size</tt>, returns all elements:
- *
- *    a = [:foo, 'bar', 2]
- *    a.first(50) # => [:foo, "bar", 2]
- *
- *  If <tt>n == 0</tt> returns an new empty \Array:
- *
- *    a = [:foo, 'bar', 2]
- *    a.first(0) # []
- *
- *  Related: #last.
- */
+#if 0
 static VALUE
 rb_ary_first(int argc, VALUE *argv, VALUE ary)
 {
@@ -2069,48 +1981,26 @@ rb_ary_first(int argc, VALUE *argv, VALUE ary)
         return ary_take_first_or_last(argc, argv, ary, ARY_TAKE_FIRST);
     }
 }
+#endif
 
-/*
- *  call-seq:
- *    array.last  -> object or nil
- *    array.last(n) -> new_array
- *
- *  Returns elements from +self+; +self+ is not modified.
- *
- *  When no argument is given, returns the last element:
- *
- *    a = [:foo, 'bar', 2]
- *    a.last # => 2
- *    a # => [:foo, "bar", 2]
- *
- *  If +self+ is empty, returns +nil+.
- *
- *  When non-negative \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:
- *
- *    a = [:foo, 'bar', 2]
- *    a.last(50) # => [:foo, "bar", 2]
- *
- *  If <tt>n == 0</tt>, returns an new empty \Array:
- *
- *    a = [:foo, 'bar', 2]
- *    a.last(0) # []
- *
- *  Related: #first.
- */
+static VALUE
+ary_first(VALUE self)
+{
+    return (RARRAY_LEN(self) == 0) ? Qnil : RARRAY_AREF(self, 0);
+}
+
+static VALUE
+ary_last(VALUE self)
+{
+    long len = RARRAY_LEN(self);
+    return (len == 0) ? Qnil : RARRAY_AREF(self, len-1);
+}
 
 VALUE
-rb_ary_last(int argc, const VALUE *argv, VALUE ary)
+rb_ary_last(int argc, const VALUE *argv, VALUE ary) // used by parse.y
 {
     if (argc == 0) {
-        long len = RARRAY_LEN(ary);
-        if (len == 0) return Qnil;
-        return RARRAY_AREF(ary, len-1);
+        return ary_last(ary);
     }
     else {
         return ary_take_first_or_last(argc, argv, ary, ARY_TAKE_LAST);
@@ -2119,17 +2009,19 @@ rb_ary_last(int argc, const VALUE *argv, VALUE ary)
 
 /*
  *  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:
  *
@@ -2137,12 +2029,12 @@ rb_ary_last(int argc, const VALUE *argv, VALUE ary)
  *    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
@@ -2152,6 +2044,7 @@ rb_ary_last(int argc, const VALUE *argv, VALUE ary)
  *    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
@@ -2183,14 +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>:
  *
@@ -2199,7 +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:
  *
@@ -2208,16 +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:
+ *  With neither an argument nor a block given, returns a new Enumerator.
  *
- *    a = [:foo, 'bar', 2]
- *    e = a.index
- *    e # => #<Enumerator: [:foo, "bar", 2]:index>
- *    e.each {|element| element == 'bar' } # => 1
- *
- *  Array#find_index is an alias for Array#index.
- *
- *  Related: #rindex.
+ *  Related: see {Methods for Querying}[rdoc-ref:Array@Methods+for+Querying].
  */
 
 static VALUE
@@ -2250,20 +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']
@@ -2271,14 +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
@@ -2343,7 +2316,7 @@ rb_ary_splice(VALUE ary, long beg, long len, const VALUE *rptr, long rlen)
     }
 
     {
-        const VALUE *optr = RARRAY_CONST_PTR_TRANSIENT(ary);
+        const VALUE *optr = RARRAY_CONST_PTR(ary);
         rofs = (rptr >= optr && rptr < optr + olen) ? rptr - optr : -1;
     }
 
@@ -2356,7 +2329,7 @@ rb_ary_splice(VALUE ary, long beg, long len, const VALUE *rptr, long rlen)
         len = beg + rlen;
         ary_mem_clear(ary, olen, beg - olen);
         if (rlen > 0) {
-            if (rofs != -1) rptr = RARRAY_CONST_PTR_TRANSIENT(ary) + rofs;
+            if (rofs != -1) rptr = RARRAY_CONST_PTR(ary) + rofs;
             ary_memcpy0(ary, beg, rlen, rptr, target_ary);
         }
         ARY_SET_LEN(ary, len);
@@ -2374,20 +2347,25 @@ rb_ary_splice(VALUE ary, long beg, long len, const VALUE *rptr, long rlen)
         }
 
         if (len != rlen) {
-            RARRAY_PTR_USE_TRANSIENT(ary, ptr,
+            RARRAY_PTR_USE(ary, ptr,
                                      MEMMOVE(ptr + beg + rlen, ptr + beg + len,
                                              VALUE, olen - (beg + len)));
             ARY_SET_LEN(ary, alen);
         }
         if (rlen > 0) {
-            if (rofs != -1) rptr = RARRAY_CONST_PTR_TRANSIENT(ary) + rofs;
-            /* give up wb-protected ary */
-            RB_OBJ_WB_UNPROTECT_FOR(ARRAY, ary);
+            if (rofs == -1) {
+                rb_gc_writebarrier_remember(ary);
+            }
+            else {
+                /* In this case, we're copying from a region in this array, so
+                 * we don't need to fire the write barrier. */
+                rptr = RARRAY_CONST_PTR(ary) + rofs;
+            }
 
             /* do not use RARRAY_PTR() because it can causes GC.
              * ary can contain T_NONE object because it is not cleared.
              */
-            RARRAY_PTR_USE_TRANSIENT(ary, ptr,
+            RARRAY_PTR_USE(ary, ptr,
                                      MEMMOVE(ptr + beg, rptr, VALUE, rlen));
         }
     }
@@ -2420,7 +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);
@@ -2432,15 +2410,14 @@ rb_ary_resize(VALUE ary, long len)
     else if (len <= ary_embed_capa(ary)) {
         const VALUE *ptr = ARY_HEAP_PTR(ary);
         long ptr_capa = ARY_HEAP_SIZE(ary);
-        bool is_malloc_ptr = !ARY_SHARED_P(ary) && !RARRAY_TRANSIENT_P(ary);
+        bool is_malloc_ptr = !ARY_SHARED_P(ary);
 
-        FL_UNSET(ary, RARRAY_TRANSIENT_FLAG);
         FL_SET_EMBED(ary);
 
         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) {
@@ -2464,20 +2441,48 @@ static VALUE
 ary_aset_by_rb_ary_splice(VALUE ary, long beg, long len, VALUE val)
 {
     VALUE rpl = rb_ary_to_ary(val);
-    rb_ary_splice(ary, beg, len, RARRAY_CONST_PTR_TRANSIENT(rpl), RARRAY_LEN(rpl));
+    rb_ary_splice(ary, beg, len, RARRAY_CONST_PTR(rpl), RARRAY_LEN(rpl));
     RB_GC_GUARD(rpl);
     return val;
 }
 
 /*
  *  call-seq:
- *    array[index] = object -> object
- *    array[start, length] = object -> object
- *    array[range] = object -> object
- *
- *  Assigns elements in +self+; returns the given +object+.
- *
- *  When \Integer argument +index+ is given, assigns +object+ to an element in +self+.
+ *    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+.
  *
  *  If +index+ is non-negative, assigns +object+ the element at offset +index+:
  *
@@ -2497,7 +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+:
  *
@@ -2532,7 +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+:
  *
@@ -2547,7 +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"
@@ -2581,6 +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
@@ -2610,38 +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
@@ -2677,14 +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
- *
- *  Iterates over array elements.
+ *    each {|element| ... } -> self
+ *    each -> new_enumerator
  *
- *  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]
@@ -2706,20 +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
@@ -2736,12 +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]
@@ -2757,26 +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:
- *
- *    a = [:foo, 'bar', 2]
- *    e = a.each_index
- *    e # => #<Enumerator: [:foo, "bar", 2]:each_index>
- *    a1 = e.each {|index|  puts "#{index} #{a[index]}"}
+ *  With no block given, returns a new Enumerator.
  *
- *  Output:
- *
- *    0 foo
- *    1 bar
- *    2 2
- *
- *  Related: #each, #reverse_each.
+ *  Related: see {Methods for Iterating}[rdoc-ref:Array@Methods+for+Iterating].
  */
 
 static VALUE
@@ -2793,47 +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:
+ *  When no block given, returns a new Enumerator.
  *
- *    a = [:foo, 'bar', 2]
- *    e = a.reverse_each
- *    e # => #<Enumerator: [:foo, "bar", 2]:reverse_each>
- *    a1 = e.each {|element|  puts "#{element.class} #{element}" }
- *
- *  Output:
- *
- *    Integer 2
- *    String bar
- *    Symbol foo
- *
- *  Related: #each, #each_index.
+ *  Related: see {Methods for Iterating}[rdoc-ref:Array@Methods+for+Iterating].
  */
 
 static VALUE
@@ -2856,9 +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+.
+ *  Returns the count of elements in +self+:
+ *
+ *    [0, 1, 2].length # => 3
+ *    [].length        # => 0
+ *
+ *  Related: see {Methods for Querying}[rdoc-ref:Array@Methods+for+Querying].
  */
 
 static VALUE
@@ -2870,10 +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
@@ -2887,7 +2893,7 @@ rb_ary_dup(VALUE ary)
 {
     long len = RARRAY_LEN(ary);
     VALUE dup = rb_ary_new2(len);
-    ary_memcpy(dup, 0, len, RARRAY_CONST_PTR_TRANSIENT(ary));
+    ary_memcpy(dup, 0, len, RARRAY_CONST_PTR(ary));
     ARY_SET_LEN(dup, len);
 
     ary_verify(ary);
@@ -3008,23 +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);
@@ -3037,31 +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)
@@ -3098,15 +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]"
  *
- *  Array#to_s is an alias for Array#inspect.
+ *  Related: see {Methods for Converting}[rdoc-ref:Array@Methods+for+Converting].
  */
 
 static VALUE
@@ -3126,21 +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
@@ -3156,27 +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
@@ -3205,7 +3214,7 @@ rb_ary_to_h(VALUE ary)
 
 /*
  *  call-seq:
- *    array.to_ary -> self
+ *    to_ary -> self
  *
  *  Returns +self+.
  */
@@ -3234,7 +3243,7 @@ rb_ary_reverse(VALUE ary)
 
     rb_ary_modify(ary);
     if (len > 1) {
-        RARRAY_PTR_USE_TRANSIENT(ary, p1, {
+        RARRAY_PTR_USE(ary, p1, {
             p2 = p1 + len - 1;	/* points last item */
             ary_reverse(p1, p2);
         }); /* WB: no new reference */
@@ -3244,13 +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
@@ -3261,14 +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
@@ -3278,8 +3289,8 @@ rb_ary_reverse_m(VALUE ary)
     VALUE dup = rb_ary_new2(len);
 
     if (len > 0) {
-        const VALUE *p1 = RARRAY_CONST_PTR_TRANSIENT(ary);
-        VALUE *p2 = (VALUE *)RARRAY_CONST_PTR_TRANSIENT(dup) + len - 1;
+        const VALUE *p1 = RARRAY_CONST_PTR(ary);
+        VALUE *p2 = (VALUE *)RARRAY_CONST_PTR(dup) + len - 1;
         do *p2-- = *p1++; while (--len > 0);
     }
     ARY_SET_LEN(dup, RARRAY_LEN(ary));
@@ -3321,7 +3332,7 @@ rb_ary_rotate(VALUE ary, long cnt)
     if (cnt != 0) {
         long len = RARRAY_LEN(ary);
         if (len > 1 && (cnt = rotate_count(cnt, len)) > 0) {
-            RARRAY_PTR_USE_TRANSIENT(ary, ptr, ary_rotate_ptr(ptr, len, cnt));
+            RARRAY_PTR_USE(ary, ptr, ary_rotate_ptr(ptr, len, cnt));
             return ary;
         }
     }
@@ -3330,48 +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
@@ -3384,51 +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:
- *
- *    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:
+ *  With non-negative numeric +count+,
+ *  rotates elements 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
@@ -3443,7 +3424,7 @@ rb_ary_rotate_m(int argc, VALUE *argv, VALUE ary)
     rotated = rb_ary_new2(len);
     if (len > 0) {
         cnt = rotate_count(cnt, len);
-        ptr = RARRAY_CONST_PTR_TRANSIENT(ary);
+        ptr = RARRAY_CONST_PTR(ary);
         len -= cnt;
         ary_memcpy(rotated, 0, len, ptr + cnt);
         ary_memcpy(rotated, len, cnt, ptr);
@@ -3521,50 +3502,19 @@ sort_2(const void *ap, const void *bp, void *dummy)
 
 /*
  *  call-seq:
- *    array.sort! -> self
- *    array.sort! {|a, b| ... } -> self
- *
- *  Returns +self+ with its elements sorted in place.
- *
- *  With no block, compares elements using operator <tt><=></tt>
- *  (see Comparable):
+ *    sort! -> self
+ *    sort! {|a, b| ... } -> self
  *
- *    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;
@@ -3582,6 +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));
         }
@@ -3591,7 +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);
                 }
@@ -3607,10 +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 */
@@ -3621,21 +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.
@@ -3643,22 +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
@@ -3673,12 +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 the element from +self+ found by a binary search,
+ *  or +nil+ if the search found no suitable element.
  *
- *  Returns an element from +self+ selected by a binary search.
+ *  See {Binary Searching}[rdoc-ref:language/bsearch.rdoc].
  *
- *  See {Binary Searching}[rdoc-ref:bsearch.rdoc].
+ *  Related: see {Methods for Fetching}[rdoc-ref:Array@Methods+for+Fetching].
  */
 
 static VALUE
@@ -3694,11 +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
  *
- *  Searches +self+ as described at method #bsearch,
- *  but returns the _index_ of the found element instead of the element itself.
+ *  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].
+ *
+ *  Related: see {Methods for Fetching}[rdoc-ref:Array@Methods+for+Fetching].
  */
 
 static VALUE
@@ -3728,8 +3679,8 @@ rb_ary_bsearch_index(VALUE ary)
             const VALUE zero = INT2FIX(0);
             switch (rb_cmpint(rb_funcallv(v, id_cmp, 1, &zero), v, zero)) {
               case 0: return INT2FIX(mid);
-              case 1: smaller = 1; break;
-              case -1: smaller = 0;
+              case 1: smaller = 0; break;
+              case -1: smaller = 1;
             }
         }
         else {
@@ -3757,28 +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
@@ -3788,30 +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.
  *
- *  Array#collect is an alias for Array#map.
+ *  Related: #collect!;
+ *  see also {Methods for Converting}[rdoc-ref:Array@Methods+for+Converting].
  */
 
 static VALUE
@@ -3831,22 +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:
+ *  With no block given, returns a new Enumerator.
  *
- *    a = [:foo, 'bar', 2]
- *    a1 = a.map!
- *    a1 # => #<Enumerator: [:foo, "bar", 2]:map!>
- *
- *  Array#collect! is an alias for Array#map!.
+ *  Related: #collect;
+ *  see also {Methods for Converting}[rdoc-ref:Array@Methods+for+Converting].
  */
 
 static VALUE
@@ -3898,7 +3847,7 @@ append_values_at_single(VALUE result, VALUE ary, long olen, VALUE idx)
     /* check if idx is Range */
     else if (rb_range_beg_len(idx, &beg, &len, olen, 1)) {
         if (len > 0) {
-            const VALUE *const src = RARRAY_CONST_PTR_TRANSIENT(ary);
+            const VALUE *const src = RARRAY_CONST_PTR(ary);
             const long end = beg + len;
             const long prevlen = RARRAY_LEN(result);
             if (beg < olen) {
@@ -3918,45 +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
@@ -3974,23 +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.
  *
- *  Array#filter is an alias for Array#select.
+ *  Related: see {Methods for Fetching}[rdoc-ref:Array@Methods+for+Fetching].
  */
 
 static VALUE
@@ -4045,7 +4056,7 @@ select_bang_ensure(VALUE a)
         rb_ary_modify(ary);
         if (i1 < len) {
             tail = len - i1;
-            RARRAY_PTR_USE_TRANSIENT(ary, ptr, {
+            RARRAY_PTR_USE(ary, ptr, {
                     MEMMOVE(ptr + i2, ptr + i1, VALUE, tail);
                 });
         }
@@ -4056,10 +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:
@@ -4069,12 +4082,9 @@ select_bang_ensure(VALUE a)
  *
  *  Returns +nil+ if no elements were removed.
  *
- *  Returns a new \Enumerator if no block given:
+ *  With no block given, returns a new Enumerator.
  *
- *    a = [:foo, 'bar', 2, :bam]
- *    a.select! # => #<Enumerator: [:foo, "bar", 2, :bam]:select!>
- *
- *  Array#filter! is an alias for Array#select!.
+ *  Related: see {Methods for Deleting}[rdoc-ref:Array@Methods+for+Deleting].
  */
 
 static VALUE
@@ -4092,20 +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
@@ -4131,38 +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
@@ -4233,7 +4242,7 @@ rb_ary_delete_at(VALUE ary, long pos)
 
     rb_ary_modify(ary);
     del = RARRAY_AREF(ary, pos);
-    RARRAY_PTR_USE_TRANSIENT(ary, ptr, {
+    RARRAY_PTR_USE(ary, ptr, {
         MEMMOVE(ptr+pos, ptr+pos+1, VALUE, len-pos-1);
     });
     ARY_INCREASE_LEN(ary, -1);
@@ -4243,9 +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+:
  *
@@ -4253,15 +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
@@ -4294,7 +4308,7 @@ ary_slice_bang_by_rb_ary_splice(VALUE ary, long pos, long len)
         return rb_ary_new2(0);
     }
     else {
-        VALUE arg2 = rb_ary_new4(len, RARRAY_CONST_PTR_TRANSIENT(ary)+pos);
+        VALUE arg2 = rb_ary_new4(len, RARRAY_CONST_PTR(ary)+pos);
         rb_ary_splice(ary, pos, len, 0, 0);
         return arg2;
     }
@@ -4302,71 +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
@@ -4447,10 +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:
  *
@@ -4459,11 +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
@@ -4476,21 +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
@@ -4506,21 +4540,20 @@ 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.
  *
-3 */
+ *  Related: see {Methods for Deleting}[rdoc-ref:Array@Methods+for+Deleting].
+ */
 
 static VALUE
 rb_ary_delete_if(VALUE ary)
@@ -4560,58 +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]]
+ *
+ *  Returned:
  *
- *  When no block given, returns a new \Array +new_array+ of size <tt>self.size</tt>
- *  whose elements are Arrays.
+ *  - 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):
  *
- *  Each nested array <tt>new_array[n]</tt> is of size <tt>other_arrays.size+1</tt>,
- *  and contains:
+ *    - The _nth_ element of +self+.
+ *    - The _nth_ element of each of the other arrays, as available.
  *
- *  - The _nth_ element of +self+.
- *  - The _nth_ element of each of the +other_arrays+.
+ *  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
@@ -4674,14 +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
@@ -4714,13 +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
@@ -4734,16 +4811,15 @@ 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));
-        ary_memcpy(copy, 0, RARRAY_LEN(orig), RARRAY_CONST_PTR_TRANSIENT(orig));
+        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));
     }
-#if USE_RVARGC
     /* orig is embedded but copy does not have enough space to embed the
      * contents of orig. */
     else if (ARY_EMBED_P(orig)) {
         long len = ARY_EMBED_LEN(orig);
-        VALUE *ptr = ary_heap_alloc(copy, len);
+        VALUE *ptr = ary_heap_alloc_buffer(len);
 
         FL_UNSET_EMBED(copy);
         ARY_SET_PTR(copy, ptr);
@@ -4752,9 +4828,8 @@ rb_ary_replace(VALUE copy, VALUE orig)
 
         // No allocation and exception expected that could leave `copy` in a
         // bad state from the edits above.
-        ary_memcpy(copy, 0, len, RARRAY_CONST_PTR_TRANSIENT(orig));
+        ary_memcpy(copy, 0, len, RARRAY_CONST_PTR(orig));
     }
-#endif
     /* Otherwise, orig is on heap and copy does not have enough space to embed
      * the contents of orig. */
     else {
@@ -4763,6 +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;
@@ -4770,13 +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
@@ -4784,11 +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);
@@ -4802,198 +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"]
+ *      ['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 +start+ and +length+, and a block given,
- *  calls the block for each index specified by start length;
- *  replaces the corresponding element with the block's return value.
+ *    If +end+ is smaller than +begin+, replaces no elements:
  *
- *  If +start+ is in range, replaces +length+ elements beginning at offset +start+:
+ *      ['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"]
  *
- *    a = ['a', 'b', 'c', 'd']
- *    a.fill(1, 1) { |index| "new_#{index}" } # => ["a", "new_1", "c", "d"]
+ *  - If either is negative (or both are negative), counts backwards from the end of +self+:
  *
- *  If start is negative, counts from the end:
+ *      ['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(-2, 1) { |index| "new_#{index}" } # => ["a", "b", "new_2", "d"]
+ *      ['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 +start+ is large (<tt>start >= array.size</tt>), extends +self+ with +nil+:
+ *  - If the +end+ value is excluded (see Range#exclude_end?), omits the last replacement:
  *
- *    a = ['a', 'b', 'c', 'd']
- *    a.fill(5, 0) { |index| "new_#{index}" } # => ["a", "b", "c", "d", nil]
- *    a = ['a', 'b', 'c', 'd']
- *    a.fill(5, 2) { |index| "new_#{index}" } # => ["a", "b", "c", "d", nil, "new_5", "new_6"]
- *
- *  If +length+ is zero or less, replaces no elements:
+ *      ['a', 'b', 'c', 'd'].fill('-', 1...2)  # => ["a", "-", "c", "d"]
+ *      ['a', 'b', 'c', 'd'].fill('-', 1...-2) # => ["a", "-", "c", "d"]
  *
- *    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) {|e| e.to_s }  # => ["a", "1", "c", "d"]
+ *      ['a', 'b', 'c', 'd'].fill(1...-2) {|e| e.to_s } # => ["a", "1", "c", "d"]
  *
- *  With arguments +obj+ and +range+, and a block given,
- *  calls the block with each index in the given range;
- *  replaces the corresponding element with the block's return value.
+ *  - If the range is endless (see {Endless Ranges}[rdoc-ref:Range@Endless+Ranges]),
+ *    replaces elements to the end of +self+:
  *
- *  If the range is positive and ascending (<tt>range 0 < range.begin <= range.end</tt>,
- *  replaces elements from <tt>range.begin</tt> to <tt>range.end</tt>:
+ *      ['a', 'b', 'c', 'd'].fill('-', 1..)          # => ["a", "-", "-", "-"]
+ *      ['a', 'b', 'c', 'd'].fill(1..) {|e| e.to_s } # => ["a", "1", "2", "3"]
  *
- *    a = ['a', 'b', 'c', 'd']
- *    a.fill(1..1) { |index| "new_#{index}" } # => ["a", "new_1", "c", "d"]
- *
- *  If +range.first+ is negative, does nothing:
- *
- *    a = ['a', 'b', 'c', 'd']
- *    a.fill(-1..1) { |index| fail 'Cannot happen' } # => ["a", "b", "c", "d"]
+ *  - If the range is beginless (see {Beginless Ranges}[rdoc-ref:Range@Beginless+Ranges]),
+ *    replaces elements from the beginning of +self+:
  *
- *  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
@@ -5062,15 +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
@@ -5085,8 +5145,8 @@ rb_ary_plus(VALUE x, VALUE y)
     len = xlen + ylen;
     z = rb_ary_new2(len);
 
-    ary_memcpy(z, 0, xlen, RARRAY_CONST_PTR_TRANSIENT(x));
-    ary_memcpy(z, xlen, ylen, RARRAY_CONST_PTR_TRANSIENT(y));
+    ary_memcpy(z, 0, xlen, RARRAY_CONST_PTR(x));
+    ary_memcpy(z, xlen, ylen, RARRAY_CONST_PTR(y));
     ARY_SET_LEN(z, len);
     return z;
 }
@@ -5096,7 +5156,7 @@ ary_append(VALUE x, VALUE y)
 {
     long n = RARRAY_LEN(y);
     if (n > 0) {
-        rb_ary_splice(x, RARRAY_LEN(x), 0, RARRAY_CONST_PTR_TRANSIENT(y), n);
+        rb_ary_splice(x, RARRAY_LEN(x), 0, RARRAY_CONST_PTR(y), n);
     }
     RB_GC_GUARD(y);
     return x;
@@ -5104,12 +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
@@ -5141,19 +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}"
  *
  */
 
@@ -5185,16 +5248,16 @@ rb_ary_times(VALUE ary, VALUE times)
     ary2 = ary_new(rb_cArray, len);
     ARY_SET_LEN(ary2, len);
 
-    ptr = RARRAY_CONST_PTR_TRANSIENT(ary);
+    ptr = RARRAY_CONST_PTR(ary);
     t = RARRAY_LEN(ary);
     if (0 < t) {
         ary_memcpy(ary2, 0, t, ptr);
         while (t <= len/2) {
-            ary_memcpy(ary2, t, t, RARRAY_CONST_PTR_TRANSIENT(ary2));
+            ary_memcpy(ary2, t, t, RARRAY_CONST_PTR(ary2));
             t *= 2;
         }
         if (t < len) {
-            ary_memcpy(ary2, t, len-t, RARRAY_CONST_PTR_TRANSIENT(ary2));
+            ary_memcpy(ary2, t, len-t, RARRAY_CONST_PTR(ary2));
         }
     }
   out:
@@ -5203,17 +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
@@ -5233,17 +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
@@ -5253,7 +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))
@@ -5298,20 +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
@@ -5325,7 +5397,7 @@ rb_ary_equal(VALUE ary1, VALUE ary2)
         return rb_equal(ary2, ary1);
     }
     if (RARRAY_LEN(ary1) != RARRAY_LEN(ary2)) return Qfalse;
-    if (RARRAY_CONST_PTR_TRANSIENT(ary1) == RARRAY_CONST_PTR_TRANSIENT(ary2)) return Qtrue;
+    if (RARRAY_CONST_PTR(ary1) == RARRAY_CONST_PTR(ary2)) return Qtrue;
     return rb_exec_recursive_paired(recursive_equal, ary1, ary2, ary2);
 }
 
@@ -5344,10 +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]
@@ -5357,6 +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
@@ -5365,49 +5439,71 @@ rb_ary_eql(VALUE ary1, VALUE ary2)
     if (ary1 == ary2) return Qtrue;
     if (!RB_TYPE_P(ary2, T_ARRAY)) return Qfalse;
     if (RARRAY_LEN(ary1) != RARRAY_LEN(ary2)) return Qfalse;
-    if (RARRAY_CONST_PTR_TRANSIENT(ary1) == RARRAY_CONST_PTR_TRANSIENT(ary2)) return Qtrue;
+    if (RARRAY_CONST_PTR(ary1) == RARRAY_CONST_PTR(ary2)) return Qtrue;
     return rb_exec_recursive_paired(recursive_eql, ary1, ary2, ary2);
 }
 
+static VALUE
+ary_hash_values(long len, const VALUE *elements, const VALUE ary)
+{
+    long i;
+    st_index_t h;
+    VALUE n;
+
+    h = rb_hash_start(len);
+    h = rb_hash_uint(h, (st_index_t)rb_ary_hash_values);
+    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)
 {
-    long i;
-    st_index_t h;
-    VALUE n;
-
-    h = rb_hash_start(RARRAY_LEN(ary));
-    h = rb_hash_uint(h, (st_index_t)rb_ary_hash);
-    for (i=0; i<RARRAY_LEN(ary); i++) {
-        n = rb_hash(RARRAY_AREF(ary, i));
-        h = rb_hash_uint(h, NUM2LONG(n));
-    }
-    h = rb_hash_end(h);
-    return ST2FIX(h);
+    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 +true+ if for some index +i+ in +self+, <tt>obj == self[i]</tt>;
- *  otherwise +false+:
+ *  Returns whether for some element +element+ in +self+,
+ *  <tt>object == element</tt>:
  *
- *    [0, 1, 2].include?(2) # => true
- *    [0, 1, 2].include?(3) # => false
+ *    [0, 1, 2].include?(2)   # => true
+ *    [0, 1, 2].include?(2.0) # => true
+ *    [0, 1, 2].include?(2.1) # => false
+ *
+ *  Related: see {Methods for Querying}[rdoc-ref:Array@Methods+for+Querying].
  */
 
 VALUE
@@ -5462,33 +5558,40 @@ recursive_cmp(VALUE ary1, VALUE ary2, int recur)
 
 /*
  *  call-seq:
- *    array <=> other_array -> -1, 0, or 1
- *
- *  Returns -1, 0, or 1 as +self+ is less than, equal to, or greater than +other_array+.
- *  For each index +i+ in +self+, evaluates <tt>result = self[i] <=> other_array[i]</tt>.
+ *    self <=> other_array -> -1, 0, or 1
  *
- *  Returns -1 if any result is -1:
+ *  Returns -1, 0, or 1 as +self+ is determined
+ *  to be less than, equal to, or greater than +other_array+.
  *
- *    [0, 1, 2] <=> [0, 1, 3] # => -1
+ *  Iterates over each index +i+ in <tt>(0...self.size)</tt>:
  *
- *  Returns 1 if any result is 1:
+ *  - Computes <tt>result[i]</tt> as <tt>self[i] <=> other_array[i]</tt>.
+ *  - Immediately returns 1 if <tt>result[i]</tt> is 1:
  *
- *    [0, 1, 2] <=> [0, 1, 1] # => 1
+ *      [0, 1, 2] <=> [0, 0, 2] # => 1
  *
- *  When all results are zero:
+ *  - Immediately returns -1 if <tt>result[i]</tt> is -1:
  *
- *  - Returns -1 if +array+ is smaller than +other_array+:
+ *      [0, 1, 2] <=> [0, 2, 2] # => -1
  *
- *      [0, 1, 2] <=> [0, 1, 2, 3] # => -1
+ *  - Continues if <tt>result[i]</tt> is 0.
  *
- *  - Returns 1 if +array+ is larger than +other_array+:
+ *  When every +result+ is 0,
+ *  returns <tt>self.size <=> other_array.size</tt>
+ *  (see Integer#<=>):
  *
- *      [0, 1, 2] <=> [0, 1] # => 1
+ *    [0, 1, 2] <=> [0, 1]        # => 1
+ *    [0, 1, 2] <=> [0, 1, 2]     # => 0
+ *    [0, 1, 2] <=> [0, 1, 2, 3]  # => -1
  *
- *  - Returns 0 if +array+ and +other_array+ are the same size:
+ *  Note that when +other_array+ is larger than +self+,
+ *  its trailing elements do not affect the result:
  *
- *      [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
@@ -5558,18 +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 from +array+
- *  that are not found in \Array +other_array+;
- *  items are compared using <tt>eql?</tt>;
- *  the order from +array+ is preserved:
+ *  Returns a new array containing only those elements of +self+
+ *  that are not found in +other_array+;
+ *  the order from +self+ is preserved:
  *
- *    [0, 1, 1, 2, 1, 1, 3, 1, 1] - [1] # => [0, 2, 3]
- *    [0, 1, 2, 3] - [3, 0] # => [1, 2]
- *    [0, 1, 2] - [4] # => [0, 1, 2]
+ *    [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]
  *
- *  Related: Array#difference.
+ *  Element are compared using method <tt>#eql?</tt>
+ *  (as defined in each element of +self+).
+ *
+ *  Related: see {Methods for Combining}[rdoc-ref:Array@Methods+for+Combining].
  */
 
 VALUE
@@ -5603,19 +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
@@ -5639,7 +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 {
@@ -5657,19 +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>:
+ *  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].
  */
 
 
@@ -5709,22 +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>:
+ *  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
@@ -5773,17 +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
@@ -5807,18 +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
@@ -5851,17 +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>.
  *
+ *  Related: see {Methods for Querying}[rdoc-ref:Array@Methods+for+Querying].
  */
 
 static VALUE
@@ -5995,42 +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)
@@ -6163,42 +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)
@@ -6242,26 +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)
@@ -6281,32 +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)
@@ -6328,7 +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);
     }
@@ -6340,25 +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
@@ -6384,28 +6522,35 @@ 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;
     long n;
 
     rb_ary_modify(ary);
-    p = t = (VALUE *)RARRAY_CONST_PTR_TRANSIENT(ary); /* WB: no new reference */
+    p = t = (VALUE *)RARRAY_CONST_PTR(ary); /* WB: no new reference */
     end = p + RARRAY_LEN(ary);
 
     while (t < end) {
         if (NIL_P(*t)) t++;
         else *p++ = *t++;
     }
-    n = p - RARRAY_CONST_PTR_TRANSIENT(ary);
+    n = p - RARRAY_CONST_PTR(ary);
     if (RARRAY_LEN(ary) == n) {
         return Qnil;
     }
@@ -6416,12 +6561,16 @@ rb_ary_compact_bang(VALUE ary)
 
 /*
  *  call-seq:
- *    array.compact -> new_array
+ *    compact -> new_array
+ *
+ *  Returns a new array containing only the non-+nil+ elements from +self+;
+ *  element order is preserved:
  *
- *  Returns a new \Array containing all non-+nil+ elements from +self+:
+ *    a = [nil, 0, nil, false, nil, '', nil, [], nil, {}]
+ *    a.compact # => [0, false, "", [], {}]
  *
- *    a = [nil, 0, nil, 1, nil, 2, nil]
- *    a.compact # => [0, 1, 2]
+ *  Related: Array#compact!;
+ *  see also {Methods for Deleting}[rdoc-ref:Array@Methods+for+Deleting].
  */
 
 static VALUE
@@ -6434,29 +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
@@ -6493,9 +6642,8 @@ static VALUE
 flatten(VALUE ary, int level)
 {
     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);
@@ -6509,7 +6657,7 @@ flatten(VALUE ary, int level)
     }
 
     result = ary_new(0, RARRAY_LEN(ary));
-    ary_memcpy(result, 0, i, RARRAY_CONST_PTR_TRANSIENT(ary));
+    ary_memcpy(result, 0, i, RARRAY_CONST_PTR(ary));
     ARY_SET_LEN(result, i);
 
     stack = ary_new(0, ARY_DEFAULT_SIZE);
@@ -6517,12 +6665,9 @@ flatten(VALUE ary, int level)
     rb_ary_push(stack, LONG2NUM(i + 1));
 
     if (level < 0) {
-        vmemo = rb_hash_new();
-        RBASIC_CLEAR_CLASS(vmemo);
-        memo = st_init_numtable();
-        rb_hash_st_table_set(vmemo, memo);
-        st_insert(memo, (st_data_t)ary, (st_data_t)Qtrue);
-        st_insert(memo, (st_data_t)tmp, (st_data_t)Qtrue);
+        memo = rb_obj_hide(rb_ident_hash_new());
+        rb_hash_aset(memo, ary, Qtrue);
+        rb_hash_aset(memo, tmp, Qtrue);
     }
 
     ary = tmp;
@@ -6537,9 +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");
             }
@@ -6548,12 +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));
@@ -6565,8 +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);
@@ -6574,7 +6716,7 @@ flatten(VALUE ary, int level)
     }
 
     if (memo) {
-        st_clear(memo);
+        rb_hash_clear(memo);
     }
 
     RBASIC_SET_CLASS(result, rb_cArray);
@@ -6583,33 +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:
+ *
+ *  - 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+).
  *
- *  Replaces each nested \Array in +self+ with the elements from that \Array;
- *  returns +self+ if any changes, +nil+ otherwise.
+ *  Returns +nil+ if no elements were flattened.
  *
- *  With non-negative \Integer argument +level+, flattens recursively through +level+ levels:
+ *  With non-negative integer argument +depth+, flattens recursively through +depth+ levels:
  *
- *    a = [ 0, [ 1, [2, 3], 4 ], 5 ]
- *    a.flatten!(1) # => [0, 1, [2, 3], 4, 5]
- *    a = [ 0, [ 1, [2, 3], 4 ], 5 ]
- *    a.flatten!(2) # => [0, 1, 2, 3, 4, 5]
- *    a = [ 0, [ 1, [2, 3], 4 ], 5 ]
- *    a.flatten!(3) # => [0, 1, 2, 3, 4, 5]
- *    [0, 1, 2].flatten!(1) # => nil
+ *    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}>]
  *
- *  With no argument, a +nil+ argument, or with negative argument +level+, flattens all levels:
+ *  With +nil+ or negative argument +depth+, flattens all levels:
  *
- *    a = [ 0, [ 1, [2, 3], 4 ], 5 ]
- *    a.flatten! # => [0, 1, 2, 3, 4, 5]
- *    [0, 1, 2].flatten! # => nil
- *    a = [ 0, [ 1, [2, 3], 4 ], 5 ]
- *    a.flatten!(-1) # => [0, 1, 2, 3, 4, 5]
- *    a = [ 0, [ 1, [2, 3], 4 ], 5 ]
- *    a.flatten!(-2) # => [0, 1, 2, 3, 4, 5]
- *    [0, 1, 2].flatten!(-1) # => nil
+ *    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
@@ -6627,7 +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);
 
@@ -6636,35 +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
@@ -6696,10 +6844,10 @@ 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_TRANSIENT(ary)) {
+            if (len != RARRAY_LEN(ary) || ptr != RARRAY_CONST_PTR(ary)) {
                 rb_raise(rb_eRuntimeError, "modified during shuffle");
             }
             tmp = ptr[--i];
@@ -6718,6 +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)
 {
@@ -6791,7 +6947,7 @@ ary_sample(rb_execution_context_t *ec, VALUE ary, VALUE randgen, VALUE nv, VALUE
             sorted[j] = idx[i] = k;
         }
         result = rb_ary_new_capa(n);
-        RARRAY_PTR_USE_TRANSIENT(result, ptr_result, {
+        RARRAY_PTR_USE(result, ptr_result, {
             for (i=0; i<n; i++) {
                 ptr_result[i] = RARRAY_AREF(ary, idx[i]);
             }
@@ -6799,11 +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++) {
@@ -6814,7 +6968,7 @@ ary_sample(rb_execution_context_t *ec, VALUE ary, VALUE randgen, VALUE nv, VALUE
             len = RARRAY_LEN(ary);
             if (len <= max_idx) n = 0;
             else if (n > len) n = len;
-            RARRAY_PTR_USE_TRANSIENT(ary, ptr_ary, {
+            RARRAY_PTR_USE(ary, ptr_ary, {
                 for (i=0; i<n; i++) {
                     long j2 = j = ptr_result[i];
                     long i2 = i;
@@ -6826,8 +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);
@@ -6849,6 +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);
@@ -6872,36 +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)
@@ -7045,82 +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
+ *    permutation(count = self.size) {|permutation| ... } -> self
+ *    permutation(count = self.size) -> new_enumerator
  *
- *  When invoked with a block, yield all permutations of elements of +self+; returns +self+.
- *  The order of permutations is indeterminate.
+ *  Iterates over permutations of the elements of +self+;
+ *  the order of permutations is indeterminate.
  *
- *  When a block and an in-range positive \Integer argument +n+ (<tt>0 < n <= self.size</tt>)
- *  are given, calls the block with all +n+-tuple permutations of +self+.
- *
- *  Example:
- *
- *    a = [0, 1, 2]
- *    a.permutation(2) {|permutation| p permutation }
- *
- *  Output:
- *
- *    [0, 1]
- *    [0, 2]
- *    [1, 0]
- *    [1, 2]
- *    [2, 0]
- *    [2, 1]
- *
- *  Another example:
+ *  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 }
- *
- *  Output:
+ *    perms = []
+ *    a.permutation(1) {|perm| perms.push(perm) }
+ *    perms # => [[0], [1], [2]]
  *
- *    [0, 1, 2]
- *    [0, 2, 1]
- *    [1, 0, 2]
- *    [1, 2, 0]
- *    [2, 0, 1]
- *    [2, 1, 0]
+ *    perms = []
+ *    a.permutation(2) {|perm| perms.push(perm) }
+ *    perms # => [[0, 1], [0, 2], [1, 0], [1, 2], [2, 0], [2, 1]]
  *
- *  When +n+ is zero, calls the block once with a new empty \Array:
+ *    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]]
  *
- *    a = [0, 1, 2]
- *    a.permutation(0) {|permutation| p permutation }
+ *  When +count+ is zero, calls the block once with a new empty array:
  *
- *  Output:
+ *    perms = []
+ *    a.permutation(0) {|perm| perms.push(perm) }
+ *    perms # => [[]]
  *
- *    []
- *
- *  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
@@ -7193,56 +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.
+ *    combination(count) {|element| ... } -> self
+ *    combination(count) -> 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 combinations of +self+.
- *
- *  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 }
- *
- *  Output:
+ *  When +count+ is zero, calls the block once with a new empty array:
  *
- *    [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
@@ -7329,68 +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:
- *
- *    a = [0, 1, 2]
- *    a.repeated_permutation(1) {|permutation| p permutation }
- *
- *  Output:
- *
- *    [0]
- *    [1]
- *    [2]
- *
- *  +n+ = 2:
- *
- *    a.repeated_permutation(2) {|permutation| p permutation }
+ *  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>.
  *
- *  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)
@@ -7461,65 +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>.
+ *  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>.
  *
- *  +n+ = 1:
- *
- *    a = [0, 1, 2]
- *    a.repeated_combination(1) {|combination| p combination }
- *
- *  Output:
- *
- *    [0]
- *    [1]
- *    [2]
- *
- *  +n+ = 2:
- *
- *    a.repeated_combination(2) {|combination| p combination }
- *
- *  Output:
+ *  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
@@ -7559,62 +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]]
- *
- *  When a block is given, yields each combination as an \Array; returns +self+:
+ *  If +self+ or any argument is empty, returns an empty array:
  *
- *    a.product(a1) {|combination| p combination }
+ *    [].product([2, 3], [4, 5]) # => []
+ *    [0, 1].product([2, 3], []) # => []
  *
- *  Output:
+ *  If no argument is given, returns an array of 1-element arrays,
+ *  each containing an element of +self+:
  *
- *    [0, 3]
- *    [0, 4]
- *    [1, 3]
- *    [1, 4]
- *    [2, 3]
- *    [2, 4]
+ *    a.product # => [[0], [1], [2]]
  *
- *  If any argument is an empty \Array, does not call the block:
+ *  With a block given, calls the block with each combination; returns +self+:
  *
- *    a.product(a1, a2, []) {|combination| fail 'Cannot happen' }
+ *    p = []
+ *    [0, 1].product([2, 3]) {|combination| p.push(combination) }
+ *    p # => [[0, 2], [0, 3], [1, 2], [1, 3]]
  *
- *  If no argument is given, yields each element of +self+ as a 1-element \Array:
+ *  If +self+ or any argument is empty, does not call the block:
  *
- *    a.product {|combination| p combination }
+ *    [].product([2, 3], [4, 5]) {|combination| fail 'Cannot happen' }
+ *    # => []
+ *    [0, 1].product([2, 3], []) {|combination| fail 'Cannot happen' }
+ *    # => [0, 1]
  *
- *  Output:
+ *  If no argument is given, calls the block with each element of +self+ as a 1-element array:
  *
- *    [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
@@ -7707,20 +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+.
- *
- *  Examples:
+ *  Returns a new array containing the first +count+ element of +self+
+ *  (as available);
+ *  +count+ must be a non-negative numeric;
+ *  does not modify +self+:
  *
- *    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
@@ -7735,25 +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
@@ -7770,10 +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:
@@ -7782,7 +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
@@ -7801,23 +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
@@ -7834,35 +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.
  *
- *  With no block given and no argument, returns +true+ if +self+ has any truthy element,
- *  +false+ otherwise:
+ *  With no block and no argument, returns whether any element of +self+ is truthy:
  *
- *    [nil, 0, false].any? # => true
- *    [nil, false].any? # => false
- *    [].any? # => false
+ *    [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.
  *
- *  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:
+ *  With argument +object+ given,
+ *  returns whether <tt>object === ele</tt> for any element +ele+ in +self+:
  *
- *    [0, 1, 2].any? {|element| element > 1 } # => true
- *    [0, 1, 2].any? {|element| element > 2 } # => false
+ *    [nil, false, 0].any?(0)          # => true
+ *    [nil, false, 1].any?(0)          # => false
+ *    [nil, false, 'food'].any?(/foo/) # => true
+ *    [nil, false, 'food'].any?(/bar/) # => false
  *
- *  If argument +obj+ is given, returns +true+ if +obj+.<tt>===</tt> any element,
- *  +false+ otherwise:
+ *  With a block given,
+ *  calls the block with each element in +self+;
+ *  returns whether the block returns any truthy value:
  *
- *    ['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
+ *    [0, 1, 2].any? {|ele| ele < 1 } # => true
+ *    [0, 1, 2].any? {|ele| ele < 0 } # => false
  *
- *  Related: Enumerable#any?
+ *  With both a block and argument +object+ given,
+ *  ignores the block and uses +object+ as above.
+ *
+ *  <b>Special case</b>: returns +false+ if +self+ is empty
+ *  (regardless of any given argument or block).
+ *
+ *  Related: see {Methods for Querying}[rdoc-ref:Array@Methods+for+Querying].
  */
 
 static VALUE
@@ -7895,34 +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.
  *
- *  With no block given and no argument, returns +true+ if +self+ contains only truthy elements,
- *  +false+ otherwise:
+ *  With no block and no argument,
+ *  returns whether every element of +self+ is truthy:
  *
- *    [0, 1, :foo].all? # => true
- *    [0, nil, 2].all? # => false
- *    [].all? # => true
+ *    [[], {}, '', 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 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 argument +object+ given, returns whether <tt>object === ele</tt>
+ *  for every element +ele+ in +self+:
  *
- *    [0, 1, 2].all? { |element| element < 3 } # => true
- *    [0, 1, 2].all? { |element| element < 2 } # => false
+ *    [0, 0, 0].all?(0)                    # => true
+ *    [0, 1, 2].all?(1)                    # => false
+ *    ['food', 'fool', 'foot'].all?(/foo/) # => true
+ *    ['food', 'drink'].all?(/foo/)        # => false
  *
- *  If argument +obj+ is given, returns +true+ if <tt>obj.===</tt> every element, +false+ otherwise:
+ *  With a block given, calls the block with each element in +self+;
+ *  returns whether the block returns only truthy values:
  *
- *    ['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
+ *    [0, 1, 2].all? { |ele| ele < 3 } # => true
+ *    [0, 1, 2].all? { |ele| ele < 2 } # => false
+ *
+ *  With both a block and argument +object+ given,
+ *  ignores the block and uses +object+ as above.
  *
- *  Related: Enumerable#all?
+ *  <b>Special case</b>: returns +true+ if +self+ is empty
+ *  (regardless of any given argument or block).
+ *
+ *  Related: see {Methods for Querying}[rdoc-ref:Array@Methods+for+Querying].
  */
 
 static VALUE
@@ -7955,34 +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 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 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 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
@@ -8015,9 +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.
  *
@@ -8029,14 +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
@@ -8046,7 +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
@@ -8089,11 +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:
@@ -8104,6 +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
@@ -8132,40 +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#+.
  *
  */
@@ -8186,6 +8254,16 @@ rb_ary_sum(int argc, VALUE *argv, VALUE ary)
 
     n = 0;
     r = Qundef;
+
+    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;
+    }
+
     for (i = 0; i < RARRAY_LEN(ary); i++) {
         e = RARRAY_AREF(ary, i);
         if (block_given)
@@ -8209,12 +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
@@ -8270,6 +8349,7 @@ rb_ary_sum(int argc, VALUE *argv, VALUE ary)
     }
 
     goto has_some_value;
+    init_is_a_value:
     for (; i < RARRAY_LEN(ary); i++) {
         e = RARRAY_AREF(ary, i);
         if (block_given)
@@ -8280,6 +8360,7 @@ rb_ary_sum(int argc, VALUE *argv, VALUE ary)
     return v;
 }
 
+/* :nodoc: */
 static VALUE
 rb_ary_deconstruct(VALUE ary)
 {
@@ -8287,15 +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.
@@ -8307,6 +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:
  *
@@ -8319,31 +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]
@@ -8352,7 +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]
@@ -8407,8 +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.
@@ -8458,7 +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']
@@ -8473,7 +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 #<<
  *
@@ -8534,11 +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.
@@ -8598,10 +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:
@@ -8623,148 +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
  *
@@ -8775,7 +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.
  */
@@ -8783,6 +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);
 
@@ -8807,8 +8899,6 @@ Init_Array(void)
     rb_define_method(rb_cArray, "[]=", rb_ary_aset, -1);
     rb_define_method(rb_cArray, "at", rb_ary_at, 1);
     rb_define_method(rb_cArray, "fetch", rb_ary_fetch, -1);
-    rb_define_method(rb_cArray, "first", rb_ary_first, -1);
-    rb_define_method(rb_cArray, "last", rb_ary_last, -1);
     rb_define_method(rb_cArray, "concat", rb_ary_concat_multi, -1);
     rb_define_method(rb_cArray, "union", rb_ary_union_multi, -1);
     rb_define_method(rb_cArray, "difference", rb_ary_difference_multi, -1);
@@ -8828,6 +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);
@@ -8905,8 +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 b9fa9844e6..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+:
+  #
+  #   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]
   #
-  # 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]
+  # Duplicate elements are included:
   #
-  # The optional +random+ argument will be used as the random number generator:
-  #    a.shuffle(random: Random.new(1))  #=> [1, 3, 2]
+  #   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) }
@@ -66,4 +101,207 @@ class Array
       Primitive.ary_sample(random, n, ary)
     end
   end
+
+  # call-seq:
+  #   first -> object or nil
+  #   first(count) -> new_array
+  #
+  # Returns elements from +self+, or +nil+; does not modify +self+.
+  #
+  # With no argument given, returns the first element (if available):
+  #
+  #   a = [:foo, 'bar', 2]
+  #   a.first # => :foo
+  #   a # => [:foo, "bar", 2]
+  #
+  # If +self+ is empty, returns +nil+.
+  #
+  #   [].first # => nil
+  #
+  # With a non-negative integer argument +count+ given,
+  # returns the first +count+ elements (as available) in a new array:
+  #
+  #   a.first(0)  # => []
+  #   a.first(2)  # => [:foo, "bar"]
+  #   a.first(50) # => [:foo, "bar", 2]
+  #
+  # Related: see {Methods for Querying}[rdoc-ref:Array@Methods+for+Querying].
+  def first n = unspecified = true
+    if Primitive.mandatory_only?
+      Primitive.attr! :leaf
+      Primitive.cexpr! %q{ ary_first(self) }
+    else
+      if unspecified
+        Primitive.cexpr! %q{ ary_first(self) }
+      else
+        Primitive.cexpr! %q{  ary_take_first_or_last_n(self, NUM2LONG(n), ARY_TAKE_FIRST) }
+      end
+    end
+  end
+
+  # call-seq:
+  #  last  -> last_object or nil
+  #  last(count) -> new_array
+  #
+  # Returns elements from +self+, or +nil+; +self+ is not modified.
+  #
+  # 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
+  #
+  #
+  # 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) # => []
+  #
+  # Related: see {Methods for Fetching}[rdoc-ref:Array@Methods+for+Fetching].
+  def last n = unspecified = true
+    if Primitive.mandatory_only?
+      Primitive.attr! :leaf
+      Primitive.cexpr! %q{ ary_last(self) }
+    else
+      if unspecified
+        Primitive.cexpr! %q{ ary_last(self) }
+      else
+        Primitive.cexpr! %q{ ary_take_first_or_last_n(self, NUM2LONG(n), ARY_TAKE_LAST) }
+      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 adb7287ed3..1ddc2b5791 100644
--- a/ast.c
+++ b/ast.c
@@ -1,6 +1,6 @@
 /* indent-tabs-mode: nil */
 #include "internal.h"
-#include "internal/parse.h"
+#include "internal/ruby_parser.h"
 #include "internal/symbol.h"
 #include "internal/warnings.h"
 #include "iseq.h"
@@ -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_keep_script_lines(vparser);
-    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_keep_script_lines(vparser);
-    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_keep_script_lines(vparser);
-    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);
@@ -185,20 +206,6 @@ node_find(VALUE self, const int node_id)
 extern VALUE rb_e_script;
 
 static VALUE
-script_lines(VALUE path)
-{
-    VALUE hash, lines;
-    ID script_lines;
-    CONST_ID(script_lines, "SCRIPT_LINES__");
-    if (!rb_const_defined_at(rb_cObject, script_lines)) return Qnil;
-    hash = rb_const_get_at(rb_cObject, script_lines);
-    if (!RB_TYPE_P(hash, T_HASH)) return Qnil;
-    lines = rb_hash_lookup(hash, path);
-    if (!RB_TYPE_P(lines, T_ARRAY)) return Qnil;
-    return lines;
-}
-
-static VALUE
 node_id_for_backtrace_location(rb_execution_context_t *ec, VALUE module, VALUE location)
 {
     int node_id;
@@ -245,6 +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);
@@ -254,7 +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) {
@@ -300,10 +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;
@@ -315,39 +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 NODE *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 = node->nd_next, 1));
+        (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 NODE *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 = node->nd_next;
-        rb_ary_push(ary, NEW_CHILD(ast, node->nd_head));
+        node = RNODE_LIST(node->nd_next);
+        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;
 }
@@ -369,307 +399,354 @@ 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[DECIMAL_SIZE_OF_BITS(sizeof(long) * CHAR_BIT) + 2]; /* including '$' */
+    char name[sizeof("$") + DECIMAL_SIZE_OF(long)];
 
     enum node_type type = nd_type(node);
     switch (type) {
       case NODE_BLOCK:
-        return dump_block(ast, node);
+        return dump_block(ast_value, RNODE_BLOCK(node));
       case NODE_IF:
-        return rb_ary_new_from_node_args(ast, 3, node->nd_cond, node->nd_body, 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, node->nd_cond, node->nd_body, 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, node->nd_head, 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, node->nd_head, 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, node->nd_head, 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, node->nd_head, node->nd_body, 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, node->nd_head, node->nd_body, 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, node->nd_cond, node->nd_body),
-                           RBOOL(node->nd_state));
+        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, node->nd_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, 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_value, 1, RNODE_BREAK(node)->nd_stts);
       case NODE_NEXT:
+        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, 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, 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, node->nd_head, node->nd_resq, 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, node->nd_args, node->nd_body, 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, node->nd_head, 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, node->nd_1st));
-                if (!node->nd_2nd || !nd_type_p(node->nd_2nd, type))
+                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 = node->nd_2nd;
+                node = RNODE_AND(node)->nd_2nd;
             }
-            rb_ary_push(ary, NEW_CHILD(ast, 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(node->nd_args)) {
-            return rb_ary_new_from_node_args(ast, 3, node->nd_value, node->nd_head, node->nd_args);
+        if (NODE_NAMED_REST_P(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, node->nd_value),
-                                        NEW_CHILD(ast, 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_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_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_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_value, RNODE_CVASGN(node)->nd_value));
       case NODE_GASGN:
-        if (NODE_REQUIRED_KEYWORD_P(node)) {
-            return rb_ary_new_from_args(2, var_name(node->nd_vid), ID2SYM(rb_intern("NODE_SPECIAL_REQUIRED_KEYWORD")));
-        }
-        return rb_ary_new_from_args(2, var_name(node->nd_vid), NEW_CHILD(ast, node->nd_value));
+        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 (node->nd_vid) {
-            return rb_ary_new_from_args(2, ID2SYM(node->nd_vid), NEW_CHILD(ast, node->nd_value));
+        if (RNODE_CDECL(node)->nd_vid) {
+            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, node->nd_else), ID2SYM(node->nd_else->nd_mid), NEW_CHILD(ast, 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, node->nd_recv),
-                                    ID2SYM(node->nd_mid),
-                                    NEW_CHILD(ast, node->nd_args->nd_head),
-                                    NEW_CHILD(ast, node->nd_args->nd_body));
+        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_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, node->nd_recv),
-                                    RBOOL(node->nd_next->nd_aid),
-                                    ID2SYM(node->nd_next->nd_vid),
-                                    ID2SYM(node->nd_next->nd_mid),
-                                    NEW_CHILD(ast, node->nd_value));
+        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_value, RNODE_OP_ASGN2(node)->nd_value));
       case NODE_OP_ASGN_AND:
-        return rb_ary_new_from_args(3, NEW_CHILD(ast, node->nd_head), ID2SYM(idANDOP),
-                                    NEW_CHILD(ast, node->nd_value));
+        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, node->nd_head), ID2SYM(idOROP),
-                                    NEW_CHILD(ast, 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, node->nd_head),
-                                    ID2SYM(node->nd_aid),
-                                    NEW_CHILD(ast, node->nd_value));
+        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_value, RNODE_OP_CDECL(node)->nd_value));
       case NODE_CALL:
+        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_value, RNODE_CALL(node)->nd_args));
       case NODE_OPCALL:
+        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_value, RNODE_OPCALL(node)->nd_args));
       case NODE_QCALL:
-        return rb_ary_new_from_args(3, NEW_CHILD(ast, node->nd_recv),
-                                    ID2SYM(node->nd_mid),
-                                    NEW_CHILD(ast, node->nd_args));
+        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_value, RNODE_QCALL(node)->nd_args));
       case NODE_FCALL:
-        return rb_ary_new_from_args(2, ID2SYM(node->nd_mid),
-                                    NEW_CHILD(ast, node->nd_args));
+        return rb_ary_new_from_args(2, ID2SYM(RNODE_FCALL(node)->nd_mid),
+                                    NEW_CHILD(ast_value, RNODE_FCALL(node)->nd_args));
       case NODE_VCALL:
-        return rb_ary_new_from_args(1, ID2SYM(node->nd_mid));
+        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, 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:
-      case NODE_VALUES:
-        return dump_array(ast, 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, 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, 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:
-        return rb_ary_new_from_args(1, var_name(node->nd_vid));
+        return rb_ary_new_from_args(1, var_name(RNODE_DVAR(node)->nd_vid));
       case NODE_IVAR:
+        return rb_ary_new_from_args(1, ID2SYM(RNODE_IVAR(node)->nd_vid));
       case NODE_CONST:
+        return rb_ary_new_from_args(1, ID2SYM(RNODE_CONST(node)->nd_vid));
       case NODE_CVAR:
+        return rb_ary_new_from_args(1, ID2SYM(RNODE_CVAR(node)->nd_vid));
       case NODE_GVAR:
-        return rb_ary_new_from_args(1, ID2SYM(node->nd_vid));
+        return rb_ary_new_from_args(1, ID2SYM(RNODE_GVAR(node)->nd_vid));
       case NODE_NTH_REF:
-        snprintf(name, sizeof(name), "$%ld", node->nd_nth);
+        snprintf(name, sizeof(name), "$%ld", RNODE_NTH_REF(node)->nd_nth);
         return rb_ary_new_from_args(1, ID2SYM(rb_intern(name)));
       case NODE_BACK_REF:
         name[0] = '$';
-        name[1] = (char)node->nd_nth;
+        name[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 (node->nd_args) {
-            return rb_ary_new_from_node_args(ast, 3, node->nd_recv, node->nd_value, node->nd_args);
+        if (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, node->nd_recv, 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, node->nd_recv, 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, 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, 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:
       case NODE_DSYM:
         {
-            NODE *n = node->nd_next;
+            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, 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, 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, node->nd_head, 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, node->nd_head, 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, 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, node->nd_head, 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(node->nd_mid), NEW_CHILD(ast, 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, node->nd_recv), ID2SYM(node->nd_mid), NEW_CHILD(ast, 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, node->nd_1st, 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(node->nd_alias), ID2SYM(node->nd_orig));
+        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, 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, node->nd_cpath, node->nd_super, 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, node->nd_cpath, 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, node->nd_recv, 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, node->nd_head), ID2SYM(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(node->nd_mid));
+        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, node->nd_beg, 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, 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, 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, node->nd_recv), ID2SYM(node->nd_mid), NEW_CHILD(ast, 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, 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, node->nd_body, 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, node->nd_body, 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(node->nd_1st)) {
-            return rb_ary_new_from_node_args(ast, 2, node->nd_1st, node->nd_2nd);
+        if (NODE_NAMED_REST_P(RNODE_POSTARG(node)->nd_1st)) {
+            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, node->nd_2nd));
+                                    NEW_CHILD(ast_value, RNODE_POSTARG(node)->nd_2nd));
       case NODE_ARGS:
         {
-            struct rb_args_info *ainfo = 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, 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, 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:
         {
-            rb_ast_id_table_t *tbl = node->nd_tbl;
+            rb_ast_id_table_t *tbl = RNODE_SCOPE(node)->nd_tbl;
             int i, size = tbl ? tbl->size : 0;
             VALUE locals = rb_ary_new_capa(size);
             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->nd_args), NEW_CHILD(ast, 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:
         {
-            struct rb_ary_pattern_info *apinfo = node->nd_apinfo;
-            VALUE rest = rest_arg(ast, apinfo->rest_arg);
+            VALUE rest = rest_arg(ast_value, RNODE_ARYPTN(node)->rest_arg);
             return rb_ary_new_from_args(4,
-                                        NEW_CHILD(ast, node->nd_pconst),
-                                        NEW_CHILD(ast, apinfo->pre_args),
+                                        NEW_CHILD(ast_value, RNODE_ARYPTN(node)->nd_pconst),
+                                        NEW_CHILD(ast_value, RNODE_ARYPTN(node)->pre_args),
                                         rest,
-                                        NEW_CHILD(ast, apinfo->post_args));
+                                        NEW_CHILD(ast_value, RNODE_ARYPTN(node)->post_args));
         }
       case NODE_FNDPTN:
         {
-            struct rb_fnd_pattern_info *fpinfo = node->nd_fpinfo;
-            VALUE pre_rest = rest_arg(ast, fpinfo->pre_rest_arg);
-            VALUE post_rest = rest_arg(ast, fpinfo->post_rest_arg);
+            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, node->nd_pconst),
+                                        NEW_CHILD(ast_value, RNODE_FNDPTN(node)->nd_pconst),
                                         pre_rest,
-                                        NEW_CHILD(ast, fpinfo->args),
+                                        NEW_CHILD(ast_value, RNODE_FNDPTN(node)->args),
                                         post_rest);
         }
       case NODE_HSHPTN:
         {
-            VALUE kwrest = node->nd_pkwrestarg == NODE_SPECIAL_NO_REST_KEYWORD ? ID2SYM(rb_intern("NODE_SPECIAL_NO_REST_KEYWORD")) :
-                                                                                 NEW_CHILD(ast, node->nd_pkwrestarg);
+            VALUE kwrest = RNODE_HSHPTN(node)->nd_pkwrestarg == NODE_SPECIAL_NO_REST_KEYWORD ? ID2SYM(rb_intern("NODE_SPECIAL_NO_REST_KEYWORD")) :
+                                                                                 NEW_CHILD(ast_value, RNODE_HSHPTN(node)->nd_pkwrestarg);
 
             return rb_ary_new_from_args(3,
-                                        NEW_CHILD(ast, node->nd_pconst),
-                                        NEW_CHILD(ast, 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_LAST:
         break;
@@ -684,7 +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
@@ -726,10 +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);
 
-    return rb_ast_tokens(data->ast);
+    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 all_tokens;
 }
 
 static VALUE
@@ -756,10 +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"
@@ -769,5 +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 f3f72c747f..6380621780 100644
--- a/ast.rb
+++ b/ast.rb
@@ -13,14 +13,13 @@
 # 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
 
   #  call-seq:
-  #     RubyVM::AbstractSyntaxTree.parse(string, keep_script_lines: false, error_tolerant: false, keep_tokens: false) -> RubyVM::AbstractSyntaxTree::Node
+  #     RubyVM::AbstractSyntaxTree.parse(string, keep_script_lines: RubyVM.keep_script_lines, error_tolerant: false, keep_tokens: false) -> RubyVM::AbstractSyntaxTree::Node
   #
   #  Parses the given _string_ into an abstract syntax tree,
   #  returning the root node of that tree.
@@ -53,14 +52,14 @@ module RubyVM::AbstractSyntaxTree
   #     #  (ERROR@1:7-1:11),
   #     #  (LASGN@1:12-1:15 :y (LIT@1:14-1:15 2))]
   #
-  #  Note that parsing continues even after the errored expresion.
+  #  Note that parsing continues even after the errored expression.
   #
-  def self.parse string, keep_script_lines: false, error_tolerant: false, keep_tokens: false
+  def self.parse string, keep_script_lines: RubyVM.keep_script_lines, error_tolerant: false, keep_tokens: false
     Primitive.ast_s_parse string, keep_script_lines, error_tolerant, keep_tokens
   end
 
   #  call-seq:
-  #     RubyVM::AbstractSyntaxTree.parse_file(pathname, keep_script_lines: false, error_tolerant: false, keep_tokens: false) -> RubyVM::AbstractSyntaxTree::Node
+  #     RubyVM::AbstractSyntaxTree.parse_file(pathname, keep_script_lines: RubyVM.keep_script_lines, error_tolerant: false, keep_tokens: false) -> RubyVM::AbstractSyntaxTree::Node
   #
   #   Reads the file from _pathname_, then parses it like ::parse,
   #   returning the root node of the abstract syntax tree.
@@ -72,13 +71,13 @@ module RubyVM::AbstractSyntaxTree
   #     # => #<RubyVM::AbstractSyntaxTree::Node:SCOPE@1:0-31:3>
   #
   #   See ::parse for explanation of keyword argument meaning and usage.
-  def self.parse_file pathname, keep_script_lines: false, error_tolerant: false, keep_tokens: false
+  def self.parse_file pathname, keep_script_lines: RubyVM.keep_script_lines, error_tolerant: false, keep_tokens: false
     Primitive.ast_s_parse_file pathname, keep_script_lines, error_tolerant, keep_tokens
   end
 
   #  call-seq:
-  #     RubyVM::AbstractSyntaxTree.of(proc, keep_script_lines: false, error_tolerant: false, keep_tokens: false)   -> RubyVM::AbstractSyntaxTree::Node
-  #     RubyVM::AbstractSyntaxTree.of(method, keep_script_lines: false, error_tolerant: false, keep_tokens: false) -> RubyVM::AbstractSyntaxTree::Node
+  #     RubyVM::AbstractSyntaxTree.of(proc, keep_script_lines: RubyVM.keep_script_lines, error_tolerant: false, keep_tokens: false)   -> RubyVM::AbstractSyntaxTree::Node
+  #     RubyVM::AbstractSyntaxTree.of(method, keep_script_lines: RubyVM.keep_script_lines, error_tolerant: false, keep_tokens: false) -> RubyVM::AbstractSyntaxTree::Node
   #
   #   Returns AST nodes of the given _proc_ or _method_.
   #
@@ -93,7 +92,7 @@ module RubyVM::AbstractSyntaxTree
   #     # => #<RubyVM::AbstractSyntaxTree::Node:SCOPE@1:0-3:3>
   #
   #   See ::parse for explanation of keyword argument meaning and usage.
-  def self.of body, keep_script_lines: false, error_tolerant: false, keep_tokens: false
+  def self.of body, keep_script_lines: RubyVM.keep_script_lines, error_tolerant: false, keep_tokens: false
     Primitive.ast_s_of body, keep_script_lines, error_tolerant, keep_tokens
   end
 
@@ -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/enum_sort_by.yml b/benchmark/enum_sort_by.yml
new file mode 100644
index 0000000000..d386353888
--- /dev/null
+++ b/benchmark/enum_sort_by.yml
@@ -0,0 +1,53 @@
+prelude: |
+  array_length = 2
+  fixnum_array2 = array_length.times.to_a.map {rand(10000)}
+  float_array2 = array_length.times.to_a.map {rand(10000.0).to_f}
+  string_array2 = array_length.times.to_a.map {"r" * rand(1..10000)}
+  mix_array2 = array_length.times.to_a.map {if rand(1..100) <= 50 then rand(1..10000).to_f else rand(1..10000) end}
+  all_zero_array2 =array_length.times.to_a.map {0}
+
+  array_length = 10
+  fixnum_array10 = array_length.times.to_a.map {rand(10000)}
+  float_array10 = array_length.times.to_a.map {rand(10000.0).to_f}
+  string_array10 = array_length.times.to_a.map {"r" * rand(1..10000)}
+  mix_array10 = array_length.times.to_a.map {if rand(1..100) <= 50 then rand(1..10000).to_f else rand(1..10000) end}
+  all_zero_array10 =array_length.times.to_a.map {0}
+
+  array_length = 1000
+  fixnum_array1000 = array_length.times.to_a.map {rand(10000)}
+  float_array1000 = array_length.times.to_a.map {rand(10000.0).to_f}
+  string_array1000 = array_length.times.to_a.map {"r" * rand(1..10000)}
+  mix_array1000 = array_length.times.to_a.map {if rand(1..100) <= 50 then rand(1..10000).to_f else rand(1..10000) end}
+  all_zero_array1000 =array_length.times.to_a.map {0}
+
+  array_length = 100000
+  fixnum_array100000 = array_length.times.to_a.map {rand(10000)}
+  float_array100000 = array_length.times.to_a.map {rand(10000.0).to_f}
+  string_array100000 = array_length.times.to_a.map {"r" * rand(1..10000)}
+  mix_array100000 = array_length.times.to_a.map {if rand(1..100) <= 50 then rand(1..10000).to_f else rand(1..10000) end}
+  all_zero_array100000 =array_length.times.to_a.map {0}
+
+benchmark:
+  fixnum_array2.sort_by: fixnum_array2.sort_by {|a| a}
+  float_array2.sort_by:  float_array2.sort_by {|a| a}
+  string_length2.sort_by: string_array2.sort_by {|a| a.length}
+  mix_array2.sort_by:  mix_array2.sort_by {|a| a}
+  all_zero2.sort_by: all_zero_array2.sort_by{|a| a}
+
+  fixnum_array10.sort_by: fixnum_array10.sort_by {|a| a}
+  float_array10.sort_by:  float_array10.sort_by {|a| a}
+  string_length10.sort_by: string_array10.sort_by {|a| a.length}
+  mix_array10.sort_by:  mix_array10.sort_by {|a| a}
+  all_zero10.sort_by: all_zero_array10.sort_by{|a| a}
+
+  fixnum_array1000.sort_by: fixnum_array1000.sort_by {|a| a}
+  float_array1000.sort_by:  float_array1000.sort_by {|a| a}
+  string_length1000.sort_by: string_array1000.sort_by {|a| a.length}
+  mix_array1000.sort_by:  mix_array1000.sort_by {|a| a}
+  all_zero1000.sort_by: all_zero_array1000.sort_by{|a| a}
+
+  fixnum_array100000.sort_by: fixnum_array100000.sort_by {|a| a}
+  float_array100000.sort_by:  float_array100000.sort_by {|a| a}
+  string_length100000.sort_by: string_array100000.sort_by {|a| a.length}
+  mix_array100000.sort_by:  mix_array100000.sort_by {|a| a}
+  all_zero100000.sort_by: all_zero_array100000.sort_by{|a| a}
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/mjit.rb b/benchmark/lib/benchmark_driver/runner/mjit.rb
deleted file mode 100644
index 3a58a620de..0000000000
--- a/benchmark/lib/benchmark_driver/runner/mjit.rb
+++ /dev/null
@@ -1,34 +0,0 @@
-require 'benchmark_driver/struct'
-require 'benchmark_driver/metric'
-require 'erb'
-
-# A runner to measure after-JIT performance easily
-class BenchmarkDriver::Runner::Mjit < BenchmarkDriver::Runner::Ips
-  # JobParser returns this, `BenchmarkDriver::Runner.runner_for` searches "*::Job"
-  Job = Class.new(BenchmarkDriver::DefaultJob)
-
-  # Dynamically fetched and used by `BenchmarkDriver::JobParser.parse`
-  JobParser = BenchmarkDriver::DefaultJobParser.for(klass: Job, metrics: [METRIC]).extend(Module.new{
-    def parse(**)
-      jobs = super
-      jobs.map do |job|
-        job = job.dup
-        job.prelude = "#{job.prelude}\n#{<<~EOS}"
-          if defined?(RubyVM::MJIT) && RubyVM::MJIT.enabled?
-            __bmdv_ruby_i = 0
-            while __bmdv_ruby_i < 10000 # MJIT call threshold
-              #{job.script}
-              __bmdv_ruby_i += 1
-            end
-            RubyVM::MJIT.pause # compile
-            #{job.script}
-            RubyVM::MJIT.resume; RubyVM::MJIT.pause # recompile
-            #{job.script}
-            RubyVM::MJIT.resume; RubyVM::MJIT.pause # recompile 2
-          end
-        EOS
-        job
-      end
-    end
-  })
-end
diff --git a/benchmark/lib/benchmark_driver/runner/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/mjit_exivar.yml b/benchmark/mjit_exivar.yml
deleted file mode 100644
index 2584fa6410..0000000000
--- a/benchmark/mjit_exivar.yml
+++ /dev/null
@@ -1,18 +0,0 @@
-type: lib/benchmark_driver/runner/mjit
-prelude: |
-  class Bench < Hash
-    def initialize
-      @exivar = nil
-    end
-
-    def exivar
-      @exivar
-    end
-  end
-
-  bench = Bench.new
-
-benchmark:
-  mjit_exivar: bench.exivar
-
-loop_count: 200000000
diff --git a/benchmark/mjit_integer.yml b/benchmark/mjit_integer.yml
deleted file mode 100644
index a6b5c9ee16..0000000000
--- a/benchmark/mjit_integer.yml
+++ /dev/null
@@ -1,32 +0,0 @@
-type: lib/benchmark_driver/runner/mjit
-prelude: |
-  def mjit_abs(int)        int.abs        end
-  def mjit_bit_length(int) int.bit_length end
-  def mjit_comp(int)       ~int           end
-  def mjit_even?(int)      int.even?      end
-  def mjit_integer?(int)   int.integer?   end
-  def mjit_magnitude(int)  int.magnitude  end
-  def mjit_odd?(int)       int.odd?       end
-  def mjit_ord(int)        int.ord        end
-  def mjit_size(int)       int.size       end
-  def mjit_to_i(int)       int.to_i       end
-  def mjit_to_int(int)     int.to_int     end
-  def mjit_uminus(int)     -int           end
-  def mjit_zero?(int)      int.zero?      end
-
-benchmark:
-  - mjit_abs(-1)
-  - mjit_bit_length(100)
-  - mjit_comp(1)
-  - mjit_even?(2)
-  - mjit_integer?(0)
-  - mjit_magnitude(-1)
-  - mjit_odd?(1)
-  - mjit_ord(1)
-  - mjit_size(1)
-  - mjit_to_i(1)
-  - mjit_to_int(1)
-  - mjit_uminus(1)
-  - mjit_zero?(0)
-
-loop_count: 40000000
diff --git a/benchmark/mjit_kernel.yml b/benchmark/mjit_kernel.yml
deleted file mode 100644
index 7720e65c2c..0000000000
--- a/benchmark/mjit_kernel.yml
+++ /dev/null
@@ -1,20 +0,0 @@
-type: lib/benchmark_driver/runner/mjit
-prelude: |
-  def mjit_class(obj)
-    obj.class
-  end
-
-  def mjit_frozen?(obj)
-    obj.frozen?
-  end
-
-  str = ""
-  fstr = "".freeze
-
-benchmark:
-  - mjit_class(self)
-  - mjit_class(1)
-  - mjit_frozen?(str)
-  - mjit_frozen?(fstr)
-
-loop_count: 40000000
diff --git a/benchmark/mjit_leave.yml b/benchmark/mjit_leave.yml
deleted file mode 100644
index 9ac68b164b..0000000000
--- a/benchmark/mjit_leave.yml
+++ /dev/null
@@ -1,8 +0,0 @@
-type: lib/benchmark_driver/runner/mjit
-prelude: |
-  def leave
-    nil
-  end
-benchmark:
-  mjit_leave: leave
-loop_count: 200000000
diff --git a/benchmark/mjit_opt_cc_insns.yml b/benchmark/mjit_opt_cc_insns.yml
deleted file mode 100644
index fed6d34bd5..0000000000
--- a/benchmark/mjit_opt_cc_insns.yml
+++ /dev/null
@@ -1,27 +0,0 @@
author	Hiroshi SHIBATA <hsbt@ruby-lang.org>	2026-06-08 17:53:34 +0900
committer	git <svn-admin@ruby-lang.org>	2026-06-08 09:39:45 +0000
commit	7ed00ca7a9d3b28330afd4451b8f1613ccd01d83 (patch)
tree	00e3212c0c1cd8043bd465a87f0819de119b9397 /spec/rubyspec/core/enumerable/map_spec.rb
parent	fadf8f0ea07c94b16d99e369481c3f62614e9ebe (diff)