6745 files changed, 1034229 insertions, 393638 deletions
diff --git a/.appveyor.yml b/.appveyor.yml
new file mode 100644
index 0000000000..05ff204541
--- /dev/null
+++ b/.appveyor.yml
@@ -0,0 +1,134 @@
+---
+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 # Visual Studio 2013
+      ssl: OpenSSL-v111
+      # The worker image name. This is NOT the Visual Studio version we're using here.
+      APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2015
+      GEMS_FOR_TEST: ""
+  RELINE_TEST_ENCODING: "UTF-8"
+cache:
+  - c:\Tools\vcpkg\installed\
+for:
+-
+  matrix:
+    only:
+      - build: vs
+  install:
+    - ver
+    - chcp
+    - SET BITS=%Platform:x86=32%
+    - SET BITS=%BITS:x=%
+    - SET OPENSSL_DIR=C:\%ssl%-Win%BITS%
+    - cd C:\Tools\vcpkg
+    - git pull -q
+    - .\bootstrap-vcpkg.bat
+    - ps: Start-FileDownload 'https://github.com/microsoft/vcpkg-tool/releases/download/2023-08-09/vcpkg.exe' -FileName 'C:\Tools\vcpkg\vcpkg.exe'
+    - cd %APPVEYOR_BUILD_FOLDER%
+    - vcpkg --triplet %Platform%-windows install --x-use-aria2 libffi libyaml readline zlib
+    - CALL SET vcvars=%%^VS%VS%COMNTOOLS^%%..\..\VC\vcvarsall.bat
+    - SET vcvars
+    - '"%vcvars%" %Platform:x64=amd64%'
+    - SET ruby_path=C:\Ruby%ruby_version:-x86=%
+    - SET PATH=\usr\local\bin;%ruby_path%\bin;%PATH%;C:\msys64\mingw64\bin;C:\msys64\usr\bin
+    - ruby --version
+    - 'cl'
+    - echo> Makefile srcdir=.
+    - echo>> Makefile MSC_VER=0
+    - echo>> Makefile RT=none
+    - echo>> Makefile RT_VER=0
+    - echo>> Makefile BUILTIN_ENCOBJS=nul
+    - type win32\Makefile.sub >> Makefile
+    - nmake %mflags% up VCSUP="echo Update OK"
+    - nmake %mflags% extract-extlibs
+    - del Makefile
+    - mkdir \usr\local\bin
+    - mkdir \usr\local\include
+    - mkdir \usr\local\lib
+    - for %%I in (%OPENSSL_DIR%\*.dll) do mklink /h \usr\local\bin\%%~nxI %%I
+    - for %%I in (c:\Tools\vcpkg\installed\%Platform%-windows\bin\*.dll) do (
+        if not %%~nI == readline mklink \usr\local\bin\%%~nxI %%I
+      )
+    - attrib +r /s /d
+    - mkdir %Platform%-mswin_%vs%
+  build_script:
+    - set HAVE_GIT=no
+    - cd %APPVEYOR_BUILD_FOLDER%
+    - cd %Platform%-mswin_%vs%
+    - >-
+      ..\win32\configure.bat
+      --with-opt-dir="/usr/local;c:/Tools/vcpkg/installed/%Platform%-windows"
+      --with-openssl-dir=%OPENSSL_DIR:\=/%
+    - nmake -l
+    - nmake install-nodoc
+    - \usr\bin\ruby -v -e "p :locale => Encoding.find('locale'), :filesystem => Encoding.find('filesystem')"
+    - if not "%GEMS_FOR_TEST%" == "" \usr\bin\gem install --no-document %GEMS_FOR_TEST%
+    - \usr\bin\ruby -ropenssl -e "puts 'Build    ' + OpenSSL::OPENSSL_VERSION, 'Runtime  ' + OpenSSL::OPENSSL_LIBRARY_VERSION"
+  test_script:
+    - set /a JOBS=%NUMBER_OF_PROCESSORS%
+    - nmake -l "TESTOPTS=-v -q" btest
+    - nmake -l "TESTOPTS=-v -q" test-basic
+    - >-
+      nmake -l "TESTOPTS=--timeout-scale=3.0
+      --excludes=../test/excludes/_appveyor -j%JOBS%
+      --exclude win32ole
+      --exclude test_bignum
+      --exclude test_syntax
+      --exclude test_open-uri
+      --exclude test_bundled_ca
+      " test-all
+    # separately execute tests without -j which may crash worker with -j.
+    - >-
+      nmake -l
+      "TESTOPTS=--timeout-scale=3.0 --excludes=../test/excludes/_appveyor"
+      TESTS="
+      ../test/win32ole
+      ../test/ruby/test_bignum.rb
+      ../test/ruby/test_syntax.rb
+      ../test/open-uri/test_open-uri.rb
+      ../test/rubygems/test_bundled_ca.rb
+      " test-all
+    - nmake -l test-spec 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/.dir-locals.el b/.dir-locals.el
index 7c32d1f7ee..8f4b96445c 100644
--- a/.dir-locals.el
+++ b/.dir-locals.el
@@ -24,6 +24,8 @@
 
  (c-mode . ((c-file-style . "ruby")))
 
+ (c++-mode . ((c-file-style . "ruby")))
+
  (change-log-mode .
      ((buffer-file-coding-system . us-ascii)
       (indent-tabs-mode . t)
diff --git a/.document b/.document
index 2116ca6d26..3a6b0c238c 100644
--- a/.document
+++ b/.document
@@ -9,9 +9,28 @@
 
 # prelude
 prelude.rb
-
 rbconfig.rb
 
+array.rb
+ast.rb
+dir.rb
+gc.rb
+io.rb
+kernel.rb
+marshal.rb
+mjit.rb
+numeric.rb
+nilclass.rb
+pack.rb
+ractor.rb
+string.rb
+symbol.rb
+timev.rb
+thread_sync.rb
+trace_point.rb
+warning.rb
+yjit.rb
+
 # the lib/ directory (which has its own .document file)
 lib
 
@@ -19,14 +38,13 @@ lib
 ext
 
 # rdoc files
-NEWS
+NEWS.md
 
 README.md
 README.ja.md
 
 COPYING
 COPYING.ja
-CONTRIBUTING.md
 
 LEGAL
 
diff --git a/.gdbinit b/.gdbinit
index 0d44622691..34d044caf6 100644
--- a/.gdbinit
+++ b/.gdbinit
@@ -136,7 +136,7 @@ define rp
       printf "%sT_ARRAY%s: len=%ld ", $color_type, $color_end, $len
       if ($flags & RUBY_FL_USER2)
 	printf "(shared) shared="
-	output/x ((struct RArray*)($arg0))->as.heap.aux.shared
+	output/x ((struct RArray*)($arg0))->as.heap.aux.shared_root
 	printf " "
       else
 	printf "(ownership) capa=%ld ", ((struct RArray*)($arg0))->as.heap.aux.capa
@@ -156,12 +156,12 @@ define rp
   else
   if ($flags & RUBY_T_MASK) == RUBY_T_HASH
     printf "%sT_HASH%s: ", $color_type, $color_end,
-    if (((struct RHash *)($arg0))->basic->flags & RHASH_ST_TABLE_FLAG)
+    if (((struct RHash *)($arg0))->basic.flags & RHASH_ST_TABLE_FLAG)
       printf "st len=%ld ", ((struct RHash *)($arg0))->as.st->num_entries
     else
       printf "li len=%ld bound=%ld ", \
-        ((((struct RHash *)($arg0))->basic->flags & RHASH_AR_TABLE_SIZE_MASK) >> RHASH_AR_TABLE_SIZE_SHIFT), \
-        ((((struct RHash *)($arg0))->basic->flags & RHASH_AR_TABLE_BOUND_MASK) >> RHASH_AR_TABLE_BOUND_SHIFT)
+        ((((struct RHash *)($arg0))->basic.flags & RHASH_AR_TABLE_SIZE_MASK) >> RHASH_AR_TABLE_SIZE_SHIFT), \
+        ((((struct RHash *)($arg0))->basic.flags & RHASH_AR_TABLE_BOUND_MASK) >> RHASH_AR_TABLE_BOUND_SHIFT)
     end
     print (struct RHash *)($arg0)
   else
@@ -265,6 +265,10 @@ define rp
     printf "%sT_ZOMBIE%s: ", $color_type, $color_end
     print (struct RData *)($arg0)
   else
+  if ($flags & RUBY_T_MASK) == RUBY_T_MOVED
+    printf "%sT_MOVED%s: ", $color_type, $color_end
+    print *(struct RMoved *)$arg0
+  else
     printf "%sunknown%s: ", $color_type, $color_end
     print (struct RBasic *)($arg0)
   end
@@ -300,6 +304,7 @@ define rp
   end
   end
   end
+  end
 end
 document rp
   Print a Ruby's VALUE.
@@ -539,13 +544,13 @@ end
 
 define rp_class
   printf "(struct RClass *) %p", (void*)$arg0
-  if ((struct RClass *)($arg0))->ptr.origin_ != $arg0
-    printf " -> %p", ((struct RClass *)($arg0))->ptr.origin_
+  if RCLASS_ORIGIN((struct RClass *)($arg0)) != $arg0
+    printf " -> %p", RCLASS_ORIGIN((struct RClass *)($arg0))
   end
   printf "\n"
   rb_classname $arg0
   print/x *(struct RClass *)($arg0)
-  print *((struct RClass *)($arg0))->ptr
+  print *RCLASS_EXT((struct RClass *)($arg0))
 end
 document rp_class
   Print the content of a Class/Module.
@@ -974,8 +979,8 @@ end
 
 define rb_ps_vm
   print $ps_vm = (rb_vm_t*)$arg0
-  set $ps_thread_ln = $ps_vm->living_threads.n.next
-  set $ps_thread_ln_last = $ps_vm->living_threads.n.prev
+  set $ps_thread_ln      = $ps_vm->ractor.main_ractor.threads.set.n.next
+  set $ps_thread_ln_last = $ps_vm->ractor.main_ractor.threads.set.n.prev
   while 1
     set $ps_thread_th = (rb_thread_t *)$ps_thread_ln
     set $ps_thread = (VALUE)($ps_thread_th->self)
@@ -1097,11 +1102,11 @@ define print_id
           set $arylen = $ary->as.heap.len
         end
         set $result = $aryptr[($serial % ID_ENTRY_UNIT) * ID_ENTRY_SIZE + $t]
-	if $result != RUBY_Qnil
+        if $result != RUBY_Qnil
           print_string $result
-	else
-	  echo undef
-	end
+        else
+          echo undef
+        end
       end
     end
   end
@@ -1274,7 +1279,7 @@ document rb_count_objects
   Counts all objects grouped by type.
 end
 
-# Details: https://bugs.ruby-lang.org/projects/ruby-trunk/wiki/MachineInstructionsTraceWithGDB
+# Details: https://bugs.ruby-lang.org/projects/ruby-master/wiki/MachineInstructionsTraceWithGDB
 define trace_machine_instructions
   set logging on
   set height 0
@@ -1319,8 +1324,7 @@ define print_flags
   printf "RUBY_FL_PROMOTED0   : %s\n", ((struct RBasic*)($arg0))->flags & RUBY_FL_PROMOTED0 ? "1" : "0"
   printf "RUBY_FL_PROMOTED1   : %s\n", ((struct RBasic*)($arg0))->flags & RUBY_FL_PROMOTED1 ? "1" : "0"
   printf "RUBY_FL_FINALIZE    : %s\n", ((struct RBasic*)($arg0))->flags & RUBY_FL_FINALIZE ? "1" : "0"
-  printf "RUBY_FL_TAINT       : %s\n", ((struct RBasic*)($arg0))->flags & RUBY_FL_TAINT ? "1" : "0"
-  printf "RUBY_FL_UNTRUSTED   : %s\n", ((struct RBasic*)($arg0))->flags & RUBY_FL_UNTRUSTED ? "1" : "0"
+  printf "RUBY_FL_SHAREABLE   : %s\n", ((struct RBasic*)($arg0))->flags & RUBY_FL_SHAREABLE ? "1" : "0"
   printf "RUBY_FL_EXIVAR      : %s\n", ((struct RBasic*)($arg0))->flags & RUBY_FL_EXIVAR ? "1" : "0"
   printf "RUBY_FL_FREEZE      : %s\n", ((struct RBasic*)($arg0))->flags & RUBY_FL_FREEZE ? "1" : "0"
 
diff --git a/.git-blame-ignore-revs b/.git-blame-ignore-revs
new file mode 100644
index 0000000000..6c5eac5a0f
--- /dev/null
+++ b/.git-blame-ignore-revs
@@ -0,0 +1,23 @@
+# This is a file used by GitHub to ignore the following commits on `git blame`.
+#
+# You can also do the same thing in your local repository with:
+# $ git config --local blame.ignoreRevsFile .git-blame-ignore-revs
+
+# Expand tabs
+5b21e94bebed90180d8ff63dad03b8b948361089
+
+# Enable Style/StringLiterals cop for RubyGems/Bundler
+d7ffd3fea402239b16833cc434404a7af82d44f3
+
+# [ruby/digest] Revert tab-expansion in external files
+48b09aae7ec5632209229dcc294dd0d75a93a17f
+8a65cf3b61c60e4cb886f59a73ff6db44364bfa9
+39dc9f9093901d40d2998653948d5da38b18ee2c
+
+# [ruby/io-nonblock] Revert tab expansion
+f28287d34c03f472ffe90ea262bdde9affd4b965
+0d842fecb4f75ab3b1d4097ebdb8e88f51558041
+4ba2c66761d6a293abdfba409241d31063cefd62
+
+# Make benchmark indentation consistent
+fc4acf8cae82e5196186d3278d831f2438479d91
diff --git a/.github/SECURITY.md b/.github/SECURITY.md
new file mode 100644
index 0000000000..56baa29942
--- /dev/null
+++ b/.github/SECURITY.md
@@ -0,0 +1,9 @@
+# Security Policy
+
+## Supported Versions
+
+See <https://www.ruby-lang.org/en/downloads/branches/>.
+
+## Reporting a Vulnerability
+
+See <https://www.ruby-lang.org/en/security/>.
diff --git a/.github/codeql/codeql-config.yml b/.github/codeql/codeql-config.yml
new file mode 100644
index 0000000000..91f82b842b
--- /dev/null
+++ b/.github/codeql/codeql-config.yml
@@ -0,0 +1,3 @@
+name: "CodeQL config for the Ruby language"
+
+languages: cpp
diff --git a/.github/dependabot.yml b/.github/dependabot.yml
new file mode 100644
index 0000000000..bc63aca35b
--- /dev/null
+++ b/.github/dependabot.yml
@@ -0,0 +1,6 @@
+version: 2
+updates:
+  - package-ecosystem: 'github-actions'
+    directory: '/'
+    schedule:
+      interval: 'monthly'
diff --git a/.github/workflows/baseruby.yml b/.github/workflows/baseruby.yml
new file mode 100644
index 0000000000..ebaafe3bf0
--- /dev/null
+++ b/.github/workflows/baseruby.yml
@@ -0,0 +1,80 @@
+name: BASERUBY Check
+
+on:
+  push:
+    paths-ignore:
+      - 'doc/**'
+      - '**/man'
+      - '**.md'
+      - '**.rdoc'
+      - '**/.document'
+  pull_request:
+    paths-ignore:
+      - 'doc/**'
+      - '**/man'
+      - '**.md'
+      - '**.rdoc'
+      - '**/.document'
+  merge_group:
+    paths-ignore:
+      - 'doc/**'
+      - '**/man'
+      - '**.md'
+      - '**.rdoc'
+      - '**/.document'
+
+concurrency:
+  group: ${{ github.workflow }} / ${{ startsWith(github.event_name, 'pull') && github.ref_name || github.sha }}
+  cancel-in-progress: ${{ startsWith(github.event_name, 'pull') }}
+
+permissions:
+  contents: read
+
+jobs:
+  baseruby:
+    name: BASERUBY
+    runs-on: ubuntu-22.04
+    if: ${{ !contains(github.event.head_commit.message, '[DOC]') && !contains(github.event.pull_request.labels.*.name, 'Documentation') }}
+    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
+
+    steps:
+      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+      - uses: actions/cache@5a3ec84eff668545956fd18022155c47e93e2684 # v4.2.3
+        with:
+          path: .downloaded-cache
+          key: downloaded-cache
+      - uses: ruby/setup-ruby@13e7a03dc3ac6c3798f4570bfead2aed4d96abfb # v1.244.0
+        with:
+          ruby-version: ${{ matrix.ruby }}
+          bundler: none
+      - run: echo "GNUMAKEFLAGS=-j$((1 + $(nproc --all)))" >> $GITHUB_ENV
+      - run: sudo apt-get install build-essential autoconf bison libyaml-dev
+      - run: ./autogen.sh
+      - run: ./configure --disable-install-doc
+      - run: make common-srcs
+      - run: make incs
+      - run: make all
+      - run: make test
+      - uses: ruby/action-slack@0bd85c72233cdbb6a0fe01d37aaeff1d21b5fce1 # v3.2.1
+        with:
+          payload: |
+            {
+              "ci": "GitHub Actions",
+              "env": "${{ github.workflow }} / BASERUBY @ ${{ matrix.ruby }}",
+              "url": "https://github.com/${{ github.repository }}/actions/runs/${{ github.run_id }}",
+              "commit": "${{ github.sha }}",
+              "branch": "${{ github.ref_name }}"
+            }
+        env:
+          SLACK_WEBHOOK_URL: ${{ secrets.SIMPLER_ALERTS_URL }} # ruby-lang slack: ruby/simpler-alerts-bot
+        if: ${{ failure() && github.event_name == 'push' }}
diff --git a/.github/workflows/bundled_gems.yml b/.github/workflows/bundled_gems.yml
new file mode 100644
index 0000000000..070c0fa1dd
--- /dev/null
+++ b/.github/workflows/bundled_gems.yml
@@ -0,0 +1,166 @@
+name: bundled_gems
+
+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:
+    branches: [ "master" ]
+    paths:
+      - '.github/workflows/bundled_gems.yml'
+      - 'gems/bundled_gems'
+  schedule:
+    - cron: '45 6 * * *'
+  workflow_dispatch:
+
+permissions:  # added using https://github.com/step-security/secure-workflows
+  contents: read
+
+jobs:
+  update:
+    permissions:
+      contents: write  # for Git to git push
+    if: ${{ github.event_name != 'schedule' || github.repository == 'ruby/ruby' }}
+    name: update ${{ github.workflow }}
+    runs-on: ubuntu-latest
+    steps:
+      - name: git config
+        run: |
+          git config --global advice.detachedHead 0
+          git config --global init.defaultBranch garbage
+
+      - name: Set ENV
+        run: |
+          echo "GNUMAKEFLAGS=-j$((1 + $(nproc --all)))" >> $GITHUB_ENV
+          echo "TODAY=$(date +%F)" >> $GITHUB_ENV
+
+      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+
+      - uses: actions/cache@5a3ec84eff668545956fd18022155c47e93e2684 # v4.2.3
+        with:
+          path: .downloaded-cache
+          key: downloaded-cache-${{ 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
+
+      - name: Update bundled gems list
+        run: |
+          ruby -i~ tool/update-bundled_gems.rb gems/bundled_gems
+
+      - name: Maintain updated gems list in NEWS
+        run: |
+          #!ruby
+          require 'json'
+          news = File.read("NEWS.md")
+          prev = news[/since the \*+(\d+\.\d+\.\d+)\*+/, 1]
+          prevs = [prev, prev.sub(/\.\d+\z/, '')]
+          %W[bundled].each do |type|
+            last = JSON.parse(File.read("#{type}_gems.json"))['gems'].filter_map do |g|
+              v = g['versions'].values_at(*prevs).compact.first
+              g = g['gem']
+              g = 'RubyGems' if g == 'rubygems'
+              [g, v] if v
+            end.to_h
+            changed = File.foreach("gems/#{type}_gems").filter_map do |l|
+              next if l.start_with?("#")
+              g, v = l.split(" ", 3)
+              [g, v] unless last[g] == v
+            end
+            changed, added = changed.partition {|g, _| last[g]}
+            news.sub!(/^\*( +)The following #{type} gems? are updated\.\n+\K(?: \1\*( +).*\n)*/) do
+              mark = "#{$1} *#{$2}"
+              changed.map {|g, v|"#{mark}#{g} #{v}\n"}.join("")
+            end or next
+            news.sub!(/^\*( +)The following default gems are now bundled gems\.\n+\K(?: \1\*( +).*\n)*/) do
+              mark = "#{$1} *#{$2}"
+              added.map {|g, v|"#{mark}#{g} #{v}\n"}.join("")
+            end or next unless added.empty?
+            File.write("NEWS.md", news)
+          end
+        shell: ruby {0}
+
+      - 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
+
+      - 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
+        if: ${{ steps.diff.outcome == 'failure' }}
+
+      - name: Build
+        run: |
+          ./autogen.sh
+          ./configure -C --disable-install-doc
+          make
+        if: ${{ steps.diff.outcome == 'failure' }}
+
+      - name: Prepare bundled gems
+        run: |
+          make -s prepare-gems
+        if: ${{ steps.diff.outcome == 'failure' }}
+
+      - 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
+
+      - name: Commit
+        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: ${{ github.repository == 'ruby/ruby' && !startsWith(github.event_name, 'pull') && steps.show.outcome == 'failure' }}
+
+      - uses: ruby/action-slack@0bd85c72233cdbb6a0fe01d37aaeff1d21b5fce1 # v3.2.1
+        with:
+          payload: |
+            {
+              "ci": "GitHub Actions",
+              "env": "${{ 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: ${{ failure() && github.event_name == 'push' }}
diff --git a/.github/workflows/check_branch.yml b/.github/workflows/check_branch.yml
deleted file mode 100644
index 4a74cbd458..0000000000
--- a/.github/workflows/check_branch.yml
+++ /dev/null
@@ -1,22 +0,0 @@
-# We bidirectionally synchronize github.com/ruby/ruby.git's master branch and
-# git.ruby-lang.org/ruby.git's master branch.
-# We can use a pull request's merge button only on the master branch.
-#
-# Therefore, we require to pass this "check_branch" on all protected branches
-# to prevent us from accidentally pushing commits to GitHub directly.
-#
-# Details: https://bugs.ruby-lang.org/issues/16094
-name: pull_request
-on: [pull_request]
-jobs:
-  check_branch:
-    runs-on: ubuntu-latest
-    steps:
-      - name: Check if branch is master
-        run: |
-          if [ "$BASE_REF" != master ]; then
-            echo "Only master branch accepts a pull request, but it's '$BASE_REF'."
-            exit 1
-          fi
-        env:
-          BASE_REF: ${{ github.base_ref }}
diff --git a/.github/workflows/check_dependencies.yml b/.github/workflows/check_dependencies.yml
new file mode 100644
index 0000000000..79b2916feb
--- /dev/null
+++ b/.github/workflows/check_dependencies.yml
@@ -0,0 +1,78 @@
+name: Check Dependencies
+on:
+  push:
+    paths-ignore:
+      - 'doc/**'
+      - '**/man'
+      - '**.md'
+      - '**.rdoc'
+      - '**/.document'
+  pull_request:
+    paths-ignore:
+      - 'doc/**'
+      - '**/man'
+      - '**.md'
+      - '**.rdoc'
+      - '**/.document'
+  merge_group:
+    paths-ignore:
+      - 'doc/**'
+      - '**/man'
+      - '**.md'
+      - '**.rdoc'
+      - '**/.document'
+
+concurrency:
+  group: ${{ github.workflow }} / ${{ startsWith(github.event_name, 'pull') && github.ref_name || github.sha }}
+  cancel-in-progress: ${{ startsWith(github.event_name, 'pull') }}
+
+permissions:
+  contents: read
+
+jobs:
+  update-deps:
+    strategy:
+      matrix:
+        os: [ubuntu-22.04]
+      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
+        if: ${{ contains(matrix.os, 'ubuntu') }}
+      - name: Install libraries
+        run: |
+          brew install gmp libffi openssl@1.1 zlib autoconf automake libtool readline
+        if: ${{ contains(matrix.os, 'macos') }}
+      - name: git config
+        run: |
+          git config --global advice.detachedHead 0
+          git config --global init.defaultBranch garbage
+      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+      - uses: actions/cache@5a3ec84eff668545956fd18022155c47e93e2684 # v4.2.3
+        with:
+          path: .downloaded-cache
+          key: downloaded-cache
+      - run: ./autogen.sh
+      - name: Run configure
+        run: ./configure -C --disable-install-doc --disable-rubygems --with-gcc 'optflags=-O0' 'debugflags=-save-temps=obj -g'
+      - run: make all golf
+      - run: ruby tool/update-deps --fix
+      - run: git diff --no-ext-diff --ignore-submodules --exit-code
+      - uses: ruby/action-slack@0bd85c72233cdbb6a0fe01d37aaeff1d21b5fce1 # v3.2.1
+        with:
+          payload: |
+            {
+              "ci": "GitHub Actions",
+              "env": "${{ 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:
+          SLACK_WEBHOOK_URL: ${{ secrets.SIMPLER_ALERTS_URL }} # ruby-lang slack: ruby/simpler-alerts-bot
+        if: ${{ failure() && github.event_name == 'push' }}
diff --git a/.github/workflows/codeql-analysis.yml b/.github/workflows/codeql-analysis.yml
new file mode 100644
index 0000000000..8dba76fbe2
--- /dev/null
+++ b/.github/workflows/codeql-analysis.yml
@@ -0,0 +1,75 @@
+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: ${{ !contains(github.event.head_commit.message, '[DOC]') && !contains(github.event.pull_request.labels.*.name, 'Documentation') && github.event.head_commit.pusher.name != 'dependabot[bot]' }}
+
+    env:
+      enable_install_doc: no
+
+    steps:
+    - name: Install libraries
+      run: |
+        set -x
+        sudo apt-get update -q || :
+        sudo apt-get install --no-install-recommends -q -y build-essential libssl-dev libyaml-dev libreadline6-dev zlib1g-dev libncurses5-dev libffi-dev bison autoconf ruby
+
+    - name: Checkout repository
+      uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+
+    - uses: actions/cache@5a3ec84eff668545956fd18022155c47e93e2684 # v4.2.3
+      with:
+        path: .downloaded-cache
+        key: downloaded-cache
+
+    - name: Remove an obsolete rubygems vendored file
+      run: sudo rm /usr/lib/ruby/vendor_ruby/rubygems/defaults/operating_system.rb
+
+    - name: Initialize CodeQL
+      uses: github/codeql-action/init@959cbb7472c4d4ad70cdfe6f4976053fe48ab394 # v2.1.37
+      with:
+        config-file: ./.github/codeql/codeql-config.yml
+        trap-caching: false
+
+    - name: Set ENV
+      run: echo "GNUMAKEFLAGS=-j$((1 + $(nproc --all)))" >> $GITHUB_ENV
+
+    - name: Autobuild
+      uses: github/codeql-action/autobuild@959cbb7472c4d4ad70cdfe6f4976053fe48ab394 # v2.1.37
+
+    - name: Perform CodeQL Analysis
+      uses: github/codeql-action/analyze@959cbb7472c4d4ad70cdfe6f4976053fe48ab394 # v2.1.37
diff --git a/.github/workflows/compilers.yml b/.github/workflows/compilers.yml
new file mode 100644
index 0000000000..caf12cc0f4
--- /dev/null
+++ b/.github/workflows/compilers.yml
@@ -0,0 +1,281 @@
+name: Compilations
+
+on:
+  push:
+    paths-ignore:
+      - 'doc/**'
+      - '**/man'
+      - '**.md'
+      - '**.rdoc'
+      - '**/.document'
+  pull_request:
+    paths-ignore:
+      - 'doc/**'
+      - '**/man'
+      - '**.rdoc'
+      - '**/.document'
+  merge_group:
+    paths-ignore:
+      - 'doc/**'
+      - '**/man'
+      - '**.rdoc'
+      - '**/.document'
+
+concurrency:
+  group: ${{ github.workflow }} / ${{ startsWith(github.event_name, 'pull') && github.ref_name || github.sha }}
+  cancel-in-progress: ${{ startsWith(github.event_name, 'pull') }}
+
+# GitHub actions does not support YAML anchors.  This creative use of
+# environment variables (plus the "echo $GITHUB_ENV" hack) is to reroute that
+# restriction.
+env:
+  default_cc: clang-15
+  append_cc: ''
+
+  # -O1 is faster than -O3 in our tests... Majority of time are consumed trying
+  # to optimize binaries.  Also GitHub Actions run on relatively modern CPUs
+  # compared to, say, GCC 4 or Clang 3.  We don't specify `-march=native`
+  # because compilers tend not understand what the CPU is.
+  optflags: '-O1'
+
+  # -g0 disables backtraces when SEGV.  Do not set that.
+  debugflags: '-ggdb3'
+
+  default_configure: >-
+    --enable-debug-env
+    --disable-install-doc
+    --with-ext=-test-/cxxanyargs,+
+  append_configure: >-
+    --without-valgrind
+    --without-jemalloc
+    --without-gmp
+
+  UPDATE_UNICODE: >-
+    UNICODE_FILES=.
+    UNICODE_PROPERTY_FILES=.
+    UNICODE_AUXILIARY_FILES=.
+    UNICODE_EMOJI_FILES=.
+  CONFIGURE_TTY: never
+  GITPULLOPTIONS: --no-tags origin ${{github.ref}}
+  RUBY_DEBUG: ci rgengc
+  RUBY_TESTOPTS: >-
+    -q
+    --color=always
+    --tty=no
+
+permissions:
+  contents: read
+
+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-13 LTO'
+            container: gcc-13
+            env:
+              default_cc: 'gcc-13 -flto=auto -ffat-lto-objects -Werror=lto-type-mismatch'
+              optflags: '-O2'
+            shared: disable
+            # check: true
+          - { name: clang-16,  env: { default_cc: clang-16 } }
+          - { name: clang-15,  env: { default_cc: clang-15 } }
+          - { name: clang-14,  env: { default_cc: clang-14 } }
+          - { name: clang-13,  env: { default_cc: clang-13 } }
+          - { name: clang-12,  env: { default_cc: clang-12 } }
+          - { name: clang-11,  env: { default_cc: clang-11 } }
+          - { name: clang-10,  env: { default_cc: clang-10 } }
+          # llvm-objcopy<=9 doesn't have --wildcard. It compiles, but leaves Rust symbols in libyjit.o.
+          - { name: clang-9,   env: { default_cc: clang-9,   append_configure: '--disable-yjit' } }
+          - { name: clang-8,   env: { default_cc: clang-8,   append_configure: '--disable-yjit' } }
+          - { name: clang-7,   env: { default_cc: clang-7,   append_configure: '--disable-yjit' } }
+          - { name: clang-6.0, env: { default_cc: clang-6.0, append_configure: '--disable-yjit' } }
+          - name: 'clang-16 LTO'
+            container: clang-16
+            env:
+              default_cc: 'clang-16 -flto=auto'
+              optflags: '-O2'
+            shared: disable
+            # check: true
+
+#         - { name: aarch64-linux-gnu,     crosshost: aarch64-linux-gnu, container: crossbuild-essential-arm64 }
+#         - { name: arm-linux-gnueabi,     crosshost: arm-linux-gnueabi }
+#         - { name: arm-linux-gnueabihf,   crosshost: arm-linux-gnueabihf }
+#         - { name: i686-w64-mingw32,      crosshost: i686-w64-mingw32 }
+#         - { name: powerpc-linux-gnu,     crosshost: powerpc-linux-gnu }
+#         - { name: powerpc64le-linux-gnu, crosshost: powerpc64le-linux-gnu, container: crossbuild-essential-ppc64el }
+#         - { name: s390x-linux-gnu,       crosshost: s390x-linux-gnu, container: crossbuild-essential-s390x }
+#         - { name: x86_64-w64-mingw32,    crosshost: x86_64-w64-mingw32, container: mingw-w64 }
+
+          # -Wno-strict-prototypes is necessary with current clang-15 since
+          # older autoconf generate functions without prototype and -pedantic
+          # now implies strict-prototypes. Disabling the error but leaving the
+          # warning generates a lot of noise from use of ANYARGS in
+          # rb_define_method() and friends.
+          # See: https://github.com/llvm/llvm-project/commit/11da1b53d8cd3507959022cd790d5a7ad4573d94
+          - { name: c99,   env: { 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' } }
+
+          - { name: '-O0', env: { optflags: '-O0 -march=x86-64 -mtune=generic' } }
+#         - { name: '-O3', env: { optflags: '-O3 -march=x86-64 -mtune=generic' }, check: true }
+
+          - { name: gmp,                  env: { append_configure: '--with-gmp' } }
+          - { name: jemalloc,             env: { append_configure: '--with-jemalloc' } }
+          - { name: valgrind,             env: { append_configure: '--with-valgrind' } }
+          - { name: 'coroutine=ucontext', env: { append_configure: '--with-coroutine=ucontext' } }
+          - { name: 'coroutine=pthread',  env: { append_configure: '--with-coroutine=pthread' } }
+          - { name: disable-jit-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' } }
+
+          - { name: OPT_THREADED_CODE=1,            env: { cppflags: '-DOPT_THREADED_CODE=1' } }
+          - { name: OPT_THREADED_CODE=2,            env: { cppflags: '-DOPT_THREADED_CODE=2' } }
+          - { name: OPT_THREADED_CODE=3,            env: { cppflags: '-DOPT_THREADED_CODE=3' } }
+
+          - { name: NDEBUG,                         env: { cppflags: '-DNDEBUG' } }
+          - { name: RUBY_DEBUG,                     env: { cppflags: '-DRUBY_DEBUG' } }
+#         - { name: ARRAY_DEBUG,                    env: { cppflags: '-DARRAY_DEBUG' } }
+#         - { name: BIGNUM_DEBUG,                   env: { cppflags: '-DBIGNUM_DEBUG' } }
+#         - { name: CCAN_LIST_DEBUG,                env: { cppflags: '-DCCAN_LIST_DEBUG' } }
+#         - { name: CPDEBUG=-1,                     env: { cppflags: '-DCPDEBUG=-1' } }
+#         - { name: ENC_DEBUG,                      env: { cppflags: '-DENC_DEBUG' } }
+#         - { name: GC_DEBUG,                       env: { cppflags: '-DGC_DEBUG' } }
+#         - { name: HASH_DEBUG,                     env: { cppflags: '-DHASH_DEBUG' } }
+#         - { name: ID_TABLE_DEBUG,                 env: { cppflags: '-DID_TABLE_DEBUG' } }
+#         - { name: RGENGC_DEBUG=-1,                env: { cppflags: '-DRGENGC_DEBUG=-1' } }
+#         - { name: SYMBOL_DEBUG,                   env: { cppflags: '-DSYMBOL_DEBUG' } }
+
+#         - { name: RGENGC_CHECK_MODE,              env: { cppflags: '-DRGENGC_CHECK_MODE' } }
+#         - { name: TRANSIENT_HEAP_CHECK_MODE,      env: { cppflags: '-DTRANSIENT_HEAP_CHECK_MODE' } }
+#         - { name: VM_CHECK_MODE,                  env: { cppflags: '-DVM_CHECK_MODE' } }
+
+          - { name: USE_EMBED_CI=0,                 env: { cppflags: '-DUSE_EMBED_CI=0' } }
+          - name: USE_FLONUM=0,
+            env:
+              cppflags: '-DUSE_FLONUM=0'
+              # yjit requires FLONUM for the pointer tagging scheme
+              append_configure: '--disable-yjit'
+#         - { name: USE_GC_MALLOC_OBJ_INFO_DETAILS, env: { cppflags: '-DUSE_GC_MALLOC_OBJ_INFO_DETAILS' } }
+          - { name: USE_LAZY_LOAD,                  env: { cppflags: '-DUSE_LAZY_LOAD' } }
+#         - { name: USE_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' } }
+
+          - { name: DEBUG_FIND_TIME_NUMGUESS,       env: { cppflags: '-DDEBUG_FIND_TIME_NUMGUESS' } }
+          - { name: DEBUG_INTEGER_PACK,             env: { cppflags: '-DDEBUG_INTEGER_PACK' } }
+#         - { name: ENABLE_PATH_CHECK,              env: { cppflags: '-DENABLE_PATH_CHECK' } }
+
+          - { name: GC_DEBUG_STRESS_TO_CLASS,       env: { cppflags: '-DGC_DEBUG_STRESS_TO_CLASS' } }
+#         - { name: GC_ENABLE_LAZY_SWEEP=0,         env: { cppflags: '-DGC_ENABLE_LAZY_SWEEP=0' } }
+#         - { name: GC_PROFILE_DETAIL_MEMOTY,       env: { cppflags: '-DGC_PROFILE_DETAIL_MEMOTY' } }
+#         - { name: GC_PROFILE_MORE_DETAIL,         env: { cppflags: '-DGC_PROFILE_MORE_DETAIL' } }
+
+#         - { name: CALC_EXACT_MALLOC_SIZE,         env: { cppflags: '-DCALC_EXACT_MALLOC_SIZE' } }
+#         - { name: MALLOC_ALLOCATED_SIZE_CHECK,    env: { cppflags: '-DMALLOC_ALLOCATED_SIZE_CHECK' } }
+
+#         - { name: IBF_ISEQ_ENABLE_LOCAL_BUFFER,   env: { cppflags: '-DIBF_ISEQ_ENABLE_LOCAL_BUFFER' } }
+
+#         - { name: RGENGC_ESTIMATE_OLDMALLOC,      env: { cppflags: '-DRGENGC_ESTIMATE_OLDMALLOC' } }
+#         - { name: RGENGC_FORCE_MAJOR_GC,          env: { cppflags: '-DRGENGC_FORCE_MAJOR_GC' } }
+#         - { name: RGENGC_OBJ_INFO,                env: { cppflags: '-DRGENGC_OBJ_INFO' } }
+#         - { name: RGENGC_OLD_NEWOBJ_CHECK,        env: { cppflags: '-DRGENGC_OLD_NEWOBJ_CHECK' } }
+#         - { name: RGENGC_PROFILE,                 env: { cppflags: '-DRGENGC_PROFILE' } }
+
+#         - { name: VM_DEBUG_BP_CHECK,              env: { cppflags: '-DVM_DEBUG_BP_CHECK' } }
+#         - { name: VM_DEBUG_VERIFY_METHOD_CACHE,   env: { cppflags: '-DVM_DEBUG_VERIFY_METHOD_CACHE' } }
+
+          - { name: MJIT_FORCE_ENABLE,              env: { cppflags: '-DMJIT_FORCE_ENABLE' } }
+          - { name: YJIT_FORCE_ENABLE,              env: { cppflags: '-DYJIT_FORCE_ENABLE' } }
+
+    name: ${{ matrix.entry.name }}
+    runs-on: ubuntu-latest
+    container:
+      image: ghcr.io/ruby/ruby-ci-image:${{ 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: ${{ matrix.entry.env || matrix.env }}
+    steps:
+      - run: id
+        working-directory:
+      - run: mkdir build
+        working-directory:
+      - name: setenv
+        run: |
+          echo "GNUMAKEFLAGS=-sj$((1 + $(nproc --all)))" >> $GITHUB_ENV
+      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+        with:
+          path: src
+      - uses: actions/cache@5a3ec84eff668545956fd18022155c47e93e2684 # v4.2.3
+        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: ${{ matrix.entry.check && endsWith(matrix.entry.name, 'annocheck') }}
+
+      - uses: ruby/action-slack@0bd85c72233cdbb6a0fe01d37aaeff1d21b5fce1 # v3.2.1
+        with:
+          payload: |
+            {
+              "ci": "GitHub Actions",
+              "env": "${{ github.workflow }} / ${{ matrix.entry.name }}",
+              "url": "https://github.com/${{ github.repository }}/actions/runs/${{ github.run_id }}",
+              "commit": "${{ github.sha }}",
+              "branch": "${{ github.ref_name }}"
+            }
+        env:
+          SLACK_WEBHOOK_URL: ${{ secrets.SIMPLER_ALERTS_URL }} # ruby-lang slack: ruby/simpler-alerts-bot
+        if: ${{ failure() && github.event_name == 'push' }}
+
+defaults:
+  run:
+    working-directory: build
diff --git a/.github/workflows/coverage.yml b/.github/workflows/coverage.yml
deleted file mode 100644
index f2998047a0..0000000000
--- a/.github/workflows/coverage.yml
+++ /dev/null
@@ -1,55 +0,0 @@
-name: coverage
-on:
-  schedule:
-    - cron: '0 * * * *'
-  pull_request:
-    branches:
-      - '*'
-jobs:
-  latest:
-    runs-on: ubuntu-latest
-    steps:
-      - name: Install libraries
-        run: |
-          set -x
-          sudo sed /etc/apt/sources.list -e "s/^# deb-src/deb-src/g" -i
-          sudo apt-get update
-          sudo apt-get install ruby2.5 lcov xz-utils
-          sudo apt-get build-dep ruby2.5
-
-      # Not using official actions/checkout because it's unstable and sometimes doesn't work for a fork.
-      - name: Checkout ruby/ruby
-        run: git clone --depth=10 https://github.com/ruby/ruby . && git reset --hard "$GITHUB_SHA"
-        if: github.event_name == 'schedule'
-      - name: Checkout a pull request
-        run: git clone --depth=10 "--branch=$GITHUB_BRANCH" "https://github.com/${GITHUB_REPO}" . && git reset --hard "$GITHUB_REV"
-        env:
-          GITHUB_REV: ${{ github.event.pull_request.head.sha }}
-          GITHUB_BRANCH: ${{ github.event.pull_request.head.ref }}
-          GITHUB_REPO: ${{ github.event.pull_request.head.repo.full_name }}
-        if: github.event_name == 'pull_request'
-
-      - name: Fixed world writable dirs
-        run: |
-          chmod go-w $HOME
-          sudo chmod -R go-w /usr/share
-      - run: autoconf
-      - name: Configure with gcov
-        run: ./configure --enable-gcov
-      - name: Setup coverage tools
-        run: make update-coverage
-      - name: Build
-        run: make -j$((1 + $(nproc --all)))
-      - name: Tests
-        run: make -s check COVERAGE=true
-      - name: Aggregate coverage results
-        run: make lcov
-      - name: Upload results
-        run: |
-          xz -9 lcov-all.info
-          aws s3 cp lcov-all.info.xz s3://rubyci/coverage/lcov-all-"$GITHUB_SHA".info.xz
-          aws s3 sync lcov-out s3://rubyci/coverage-latest-html
-        env:
-          AWS_ACCESS_KEY_ID: ${{ secrets.AWS_ACCESS_KEY_ID }}
-          AWS_SECRET_ACCESS_KEY: ${{ secrets.AWS_SECRET_ACCESS_KEY }}
-        if: github.event_name == 'schedule'
diff --git a/.github/workflows/doxygen.yml b/.github/workflows/doxygen.yml
deleted file mode 100644
index fbd972a1cf..0000000000
--- a/.github/workflows/doxygen.yml
+++ /dev/null
@@ -1,58 +0,0 @@
-name: doxygen
-on:
-  schedule:
-    - cron: '20 * * * *'
-
-jobs:
-  latest:
-    runs-on: ubuntu-latest
-    steps:
-      - name: Download current index.html
-        run: |
-          curl -o /tmp/index.html https://rubyci.s3.amazonaws.com/doxygen-latest-html/index.html || touch /tmp/index.html
-          grep projectnumber /tmp/index.html || :
-          echo "GITHUB_SHA=${GITHUB_SHA}"
-          if grep -q "${GITHUB_SHA}" /tmp/index.html; then
-            echo '##[set-env name=SKIP_DOXYGEN]'true
-          else
-            echo '##[set-env name=SKIP_DOXYGEN]'false
-          fi
-      - name: Install libraries
-        run: |
-          set -x
-          sudo sed /etc/apt/sources.list -e "s/^# deb-src/deb-src/g" -i
-          sudo apt-get update
-          sudo apt-get install ruby2.5 doxygen graphviz
-          sudo apt-get build-dep ruby2.5
-        if: job.env.SKIP_DOXYGEN != 'true'
-
-      # Not using official actions/checkout because it's unstable and sometimes doesn't work for a fork.
-      - name: Checkout ruby/ruby
-        run: |
-          git clone --depth=10 https://github.com/ruby/ruby . && git reset --hard "$GITHUB_SHA"
-        if: job.env.SKIP_DOXYGEN != 'true'
-
-      - name: Fixed world writable dirs
-        run: |
-          chmod go-w $HOME
-          sudo chmod -R go-w /usr/share
-        if: job.env.SKIP_DOXYGEN != 'true'
-      - run: autoconf
-        if: job.env.SKIP_DOXYGEN != 'true'
-      - name: Configure
-        run: |
-          ./configure
-        if: job.env.SKIP_DOXYGEN != 'true'
-      - name: Generate Doxyfile
-        run: make Doxyfile
-        if: job.env.SKIP_DOXYGEN != 'true'
-      - name: Run Doxygen
-        run: doxygen
-        if: job.env.SKIP_DOXYGEN != 'true'
-      - name: Upload results
-        run: |
-          aws s3 sync doc/capi/html/ s3://rubyci/doxygen-latest-html
-        if: job.env.SKIP_DOXYGEN != 'true'
-        env:
-          AWS_ACCESS_KEY_ID: ${{ secrets.AWS_ACCESS_KEY_ID }}
-          AWS_SECRET_ACCESS_KEY: ${{ secrets.AWS_SECRET_ACCESS_KEY }}
diff --git a/.github/workflows/macos.yml b/.github/workflows/macos.yml
index 7718e019db..d8dc58b119 100644
--- a/.github/workflows/macos.yml
+++ b/.github/workflows/macos.yml
@@ -1,71 +1,113 @@
-name: macos
+name: macOS
 on:
   push:
-    branches:
-      - master
+    paths-ignore:
+      - 'doc/**'
+      - '**/man'
+      - '**.md'
+      - '**.rdoc'
+      - '**/.document'
   pull_request:
-    branches:
-      - '*'
+    paths-ignore:
+      - 'doc/**'
+      - '**/man'
+      - '**.md'
+      - '**.rdoc'
+      - '**/.document'
+  merge_group:
+    paths-ignore:
+      - 'doc/**'
+      - '**/man'
+      - '**.md'
+      - '**.rdoc'
+      - '**/.document'
+
+concurrency:
+  group: ${{ github.workflow }} / ${{ startsWith(github.event_name, 'pull') && github.ref_name || github.sha }}
+  cancel-in-progress: ${{ startsWith(github.event_name, 'pull') }}
+
+permissions:
+  contents: read
+
 jobs:
-  latest:
-    runs-on: macos-latest
+  make:
     strategy:
       matrix:
-        test_task: [ "check", "test-bundler", "test-bundled-gems" ]
+        test_task: ["check"] # "test-bundler-parallel", "test-bundled-gems"
+        os:
+          - macos-13
+          - macos-14
+          - macos-15
       fail-fast: false
+    env:
+      GITPULLOPTIONS: --no-tags origin ${{github.ref}}
+    runs-on: ${{ matrix.os }}
+    if: ${{ !contains(github.event.head_commit.message, '[DOC]') && !contains(github.event.pull_request.labels.*.name, 'Documentation') }}
     steps:
-      - name: Disable Firewall
+      - run: mkdir build
+        working-directory:
+      - name: git config
         run: |
-          sudo /usr/libexec/ApplicationFirewall/socketfilterfw --setglobalstate off
-          sudo /usr/libexec/ApplicationFirewall/socketfilterfw --getglobalstate
+          git config --global advice.detachedHead 0
+          git config --global init.defaultBranch garbage
+      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+        with:
+          path: src
+      - uses: actions/cache@5a3ec84eff668545956fd18022155c47e93e2684 # v4.2.3
+        with:
+          path: src/.downloaded-cache
+          key: downloaded-cache
       - name: Install libraries
         run: |
-          brew update || { sleep 5 && brew update; } || { sleep 60 && brew update; }
-          brew install gdbm gmp libffi openssl@1.1 zlib autoconf automake libtool readline
-      # Not using official actions/checkout because it's unstable and sometimes doesn't work for a fork.
-      - name: Checkout ruby/ruby
-        run: git clone --depth=50 https://github.com/ruby/ruby . && git reset --hard "$GITHUB_SHA"
-        if: github.event_name == 'push'
-      - name: Checkout a pull request
-        run: git clone --depth=50 "--branch=$GITHUB_BRANCH" "https://github.com/${GITHUB_REPO}" . && git reset --hard "$GITHUB_REV"
-        env:
-          GITHUB_REV: ${{ github.event.pull_request.head.sha }}
-          GITHUB_BRANCH: ${{ github.event.pull_request.head.ref }}
-          GITHUB_REPO: ${{ github.event.pull_request.head.repo.full_name }}
-        if: github.event_name == 'pull_request'
+          brew install gmp libffi openssl@1.1 zlib autoconf automake libtool readline bison
+        working-directory: src
       - name: Set ENV
         run: |
-          echo '##[set-env name=JOBS]'-j$((1 + $(sysctl -n hw.activecpu)))
-      - run: autoconf
-      - name: configure
-        run: ./configure -C --disable-install-doc --with-openssl-dir=$(brew --prefix openssl@1.1) --with-readline-dir=$(brew --prefix readline)
-      - run: make $JOBS
-      - name: Tests
-        run: make -s ${{ matrix.test_task }}
+          echo "MAKEFLAGS=-j$((1 + $(sysctl -n hw.activecpu)))" >> $GITHUB_ENV
+          echo "PATH="/usr/local/opt/bison/bin:/opt/homebrew/opt/bison/bin:$PATH"" >> $GITHUB_ENV
+      - run: ./autogen.sh
+        working-directory: src
+      - name: Run configure
+        run: ../src/configure -C --disable-install-doc --with-openssl-dir=$(brew --prefix openssl@1.1) --with-readline-dir=$(brew --prefix readline)
+      - run: make incs
+      - run: make prepare-gems
+        if: ${{ matrix.test_task == 'test-bundled-gems' }}
+      - run: make
+      - run: make leaked-globals
+        if: ${{ matrix.test_task == 'check' }}
+      - 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
         env:
-          TESTOPTS: "$JOBS -q --tty=no"
-          MSPECOPT: "-ff" # not using `-j` because sometimes `mspec -j` silently dies
-        if: matrix.test_task != 'test-bundled-gems' && !contains(github.event.head_commit.message, '[ci skip]')
-      # test-bundled-gems is separated for marking `continue-on-error` because it randomly fails.
-      - name: Tests
-        run: make -s ${{ matrix.test_task }}
+          RUBY_TESTOPTS: "-q --tty=no"
+          TESTS: ${{ matrix.test_task == 'check' && matrix.skipped_tests || '' }}
+          TEST_BUNDLED_GEMS_ALLOW_FAILURES: ""
+          PRECHECK_BUNDLED_GEMS: "no"
+      - name: make skipped tests
+        run: |
+          make -s test-all TESTS=`echo "$TESTS" | sed 's| |$$/ -n/|g;s|^|-n/|;s|$|$$/|'`
         env:
-          TESTOPTS: "$JOBS -q --tty=no"
-        continue-on-error: true
-        if: matrix.test_task == 'test-bundled-gems' && !contains(github.event.head_commit.message, '[ci skip]')
-      - name: Leaked Globals
-        run: make -s leaked-globals
-      - uses: k0kubun/action-slack@v2.0.0
+          GNUMAKEFLAGS: ""
+          RUBY_TESTOPTS: "-v --tty=no"
+          TESTS: ${{ matrix.skipped_tests }}
+          PRECHECK_BUNDLED_GEMS: "no"
+        if: ${{ matrix.test_task == 'check' && matrix.skipped_tests != '' }}
+        continue-on-error: ${{ matrix.continue-on-skipped_tests || false }}
+      - uses: ruby/action-slack@0bd85c72233cdbb6a0fe01d37aaeff1d21b5fce1 # v3.2.1
         with:
           payload: |
             {
-              "attachments": [{
-                "text": "${{ job.status}}: <https://github.com/${{ github.repository }}/commit/${{ github.sha }}/checks|${{ github.workflow }} / ${{ matrix.test_task }}> " +
-                        "(<https://github.com/${{ github.repository }}/commit/${{ github.sha }}|" + "${{ github.sha }}".substring(0, 10) + ">) " +
-                        "of ${{ github.repository }}@" + "${{ github.ref }}".split('/').reverse()[0] + " by ${{ github.event.head_commit.committer.name }}",
-                "color": "danger"
-              }]
+              "ci": "GitHub Actions",
+              "env": "${{ 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.SLACK_WEBHOOK_URL }}
-        if: failure() && github.event_name == 'push'
+          SLACK_WEBHOOK_URL: ${{ secrets.SIMPLER_ALERTS_URL }} # ruby-lang slack: ruby/simpler-alerts-bot
+        if: ${{ failure() && github.event_name == 'push' }}
+
+defaults:
+  run:
+    working-directory: build
diff --git a/.github/workflows/mingw.yml b/.github/workflows/mingw.yml
new file mode 100644
index 0000000000..0df917d3d8
--- /dev/null
+++ b/.github/workflows/mingw.yml
@@ -0,0 +1,179 @@
+name: MinGW
+on:
+  push:
+    paths-ignore:
+      - 'doc/**'
+      - '**/man'
+      - '**.md'
+      - '**.rdoc'
+      - '**/.document'
+  pull_request:
+    paths-ignore:
+      - 'doc/**'
+      - '**/man'
+      - '**.md'
+      - '**.rdoc'
+      - '**/.document'
+  merge_group:
+    paths-ignore:
+      - 'doc/**'
+      - '**/man'
+      - '**.md'
+      - '**.rdoc'
+      - '**/.document'
+
+concurrency:
+  group: ${{ github.workflow }} / ${{ startsWith(github.event_name, 'pull') && github.ref_name || github.sha }}
+  cancel-in-progress: ${{ startsWith(github.event_name, 'pull') }}
+
+permissions:
+  contents: read
+
+# Notes:
+# Actions console encoding causes issues, see test-all & test-spec steps
+#
+jobs:
+  make:
+    runs-on: windows-2022
+    name: ${{ github.workflow }} (${{ matrix.msystem }})
+    env:
+      MSYSTEM: ${{ 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"
+      UPDATE_UNICODE: "UNICODE_FILES=. UNICODE_PROPERTY_FILES=. UNICODE_AUXILIARY_FILES=. UNICODE_EMOJI_FILES=."
+      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/"
+      fail-fast: false
+    if: ${{ !contains(github.event.head_commit.message, '[DOC]') && !contains(github.event.pull_request.labels.*.name, 'Documentation') }}
+    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@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+        with:
+          path: src
+      - uses: actions/cache@5a3ec84eff668545956fd18022155c47e93e2684 # v4.2.3
+        with:
+          path: src/.downloaded-cache
+          key: downloaded-cache
+      - name: Set up Ruby & MSYS2
+        uses: ruby/setup-ruby@13e7a03dc3ac6c3798f4570bfead2aed4d96abfb # v1.244.0
+        with:
+          ruby-version: ${{ matrix.base_ruby }}
+      - name: set env
+        run: |
+          echo "GNUMAKEFLAGS=-j$((2 * NUMBER_OF_PROCESSORS))" >> $GITHUB_ENV
+
+      - name: where check
+        run: |
+          # show where
+          mv /c/Windows/System32/libcrypto-1_1-x64.dll /c/Windows/System32/libcrypto-1_1-x64.dll_
+          mv /c/Windows/System32/libssl-1_1-x64.dll    /c/Windows/System32/libssl-1_1-x64.dll_
+          result=true
+          for e in gcc.exe ragel.exe make.exe bison.exe libcrypto-1_1-x64.dll libssl-1_1-x64.dll; do
+            echo '##['group']'$'\033[93m'$e$'\033[m'
+            where $e || result=false
+            echo '##['endgroup']'
+          done
+          $result
+
+      - name: version check
+        run: |
+          # show version
+          result=true
+          for e in gcc ragel make bison "openssl version"; do
+            case "$e" in *" "*) ;; *) e="$e --version";; esac
+            echo '##['group']'$'\033[93m'$e$'\033[m'
+            $e || result=false
+            echo '##['endgroup']'
+          done
+          $result
+
+      - name: autogen
+        run: |
+          ./autogen.sh
+        working-directory: src
+
+      - name: configure
+        run: >
+          ../src/configure --disable-install-doc --prefix=/.
+          --build=$CHOST --host=$CHOST --target=$CHOST
+
+      - name: update
+        run: |
+          make incs
+
+      - name: download gems
+        run: |
+          make update-gems
+
+      - name: make all
+        timeout-minutes: 30
+        run: |
+          make
+
+      - run: make leaked-globals
+
+      - name: make install
+        run: |
+          make DESTDIR=../install install-nodoc
+
+      - name: test
+        timeout-minutes: 5
+        run: |
+          make test
+        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
+            ${{ matrix.test-all-opts }}
+          BUNDLER_VERSION:
+        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: ${{matrix.test_task == 'check' || matrix.test_task == 'test-spec' || StartsWith(matrix.test_task, 'spec/')}}
+
+      - uses: ruby/action-slack@0bd85c72233cdbb6a0fe01d37aaeff1d21b5fce1 # v3.2.1
+        with:
+          payload: |
+            {
+              "ci": "GitHub Actions",
+              "env": "${{ 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:
+          SLACK_WEBHOOK_URL: ${{ secrets.SIMPLER_ALERTS_URL }} # ruby-lang slack: ruby/simpler-alerts-bot
+        if: ${{ failure() && github.event_name == 'push' }}
+
+defaults:
+  run:
+    working-directory: build
+    shell: sh
diff --git a/.github/workflows/mjit-bindgen.yml b/.github/workflows/mjit-bindgen.yml
new file mode 100644
index 0000000000..26f8a1b2aa
--- /dev/null
+++ b/.github/workflows/mjit-bindgen.yml
@@ -0,0 +1,104 @@
+name: MJIT bindgen
+on:
+  push:
+    paths-ignore:
+      - 'doc/**'
+      - '**/man'
+      - '**.md'
+      - '**.rdoc'
+      - '**/.document'
+  pull_request:
+    paths-ignore:
+      - 'doc/**'
+      - '**/man'
+      - '**.md'
+      - '**.rdoc'
+      - '**/.document'
+  merge_group:
+    paths-ignore:
+      - 'doc/**'
+      - '**/man'
+      - '**.md'
+      - '**.rdoc'
+      - '**/.document'
+
+concurrency:
+  group: ${{ github.workflow }} / ${{ startsWith(github.event_name, 'pull') && github.ref_name || github.sha }}
+  cancel-in-progress: ${{ startsWith(github.event_name, 'pull') }}
+
+permissions:
+  contents: read
+
+jobs:
+  make:
+    strategy:
+      matrix:
+        include:
+          - task: mjit-bindgen
+      fail-fast: false
+    runs-on: ubuntu-22.04
+    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 \
+          libclang1-14 \
+          bison autoconf
+          sudo apt-get install -q -y pkg-config || :
+      - name: Set up Ruby
+        uses: ruby/setup-ruby@13e7a03dc3ac6c3798f4570bfead2aed4d96abfb # v1.244.0
+        with:
+          ruby-version: '3.1'
+      - name: git config
+        run: |
+          git config --global advice.detachedHead 0
+          git config --global init.defaultBranch garbage
+      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+        with:
+          path: src
+      - uses: actions/cache@5a3ec84eff668545956fd18022155c47e93e2684 # v4.2.3
+        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 ${{ matrix.task }}
+      - run: git diff --exit-code
+        working-directory: src
+      - uses: ruby/action-slack@0bd85c72233cdbb6a0fe01d37aaeff1d21b5fce1 # v3.2.1
+        with:
+          payload: |
+            {
+              "ci": "GitHub Actions",
+              "env": "${{ 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
new file mode 100644
index 0000000000..6f7181489a
--- /dev/null
+++ b/.github/workflows/mjit.yml
@@ -0,0 +1,113 @@
+name: MJIT
+on:
+  push:
+    paths-ignore:
+      - 'doc/**'
+      - '**/man'
+      - '**.md'
+      - '**.rdoc'
+      - '**/.document'
+  pull_request:
+    paths-ignore:
+      - 'doc/**'
+      - '**/man'
+      - '**.md'
+      - '**.rdoc'
+      - '**/.document'
+      - '**.[1-8]'
+      - '**.ronn'
+  merge_group:
+    paths-ignore:
+      - 'doc/**'
+      - '**.md'
+      - '**.rdoc'
+      - '**/.document'
+      - '**.[1-8]'
+      - '**.ronn'
+
+concurrency:
+  group: ${{ github.workflow }} / ${{ startsWith(github.event_name, 'pull') && github.ref_name || github.sha }}
+  cancel-in-progress: ${{ startsWith(github.event_name, 'pull') }}
+
+permissions:
+  contents: read
+
+jobs:
+  make:
+    strategy:
+      matrix:
+        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@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+        with:
+          path: src
+      - uses: actions/cache@5a3ec84eff668545956fd18022155c47e93e2684 # v4.2.3
+        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@0bd85c72233cdbb6a0fe01d37aaeff1d21b5fce1 # v3.2.1
+        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/publish.yml b/.github/workflows/publish.yml
new file mode 100644
index 0000000000..5d4474d978
--- /dev/null
+++ b/.github/workflows/publish.yml
@@ -0,0 +1,18 @@
+name: Start release workflow
+on:
+  push:
+    tags:
+      - '*'
+
+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/scorecards.yml b/.github/workflows/scorecards.yml
new file mode 100644
index 0000000000..c12a95362d
--- /dev/null
+++ b/.github/workflows/scorecards.yml
@@ -0,0 +1,72 @@
+# This workflow uses actions that are not certified by GitHub. They are provided
+# by a third-party and are governed by separate terms of service, privacy
+# policy, and support documentation.
+
+name: Scorecards 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
+  branch_protection_rule:
+  # 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" ]
+
+# Declare default permissions as read only.
+permissions: read-all
+
+jobs:
+  analysis:
+    name: Scorecards analysis
+    runs-on: ubuntu-latest
+    permissions:
+      # Needed to upload the results to code-scanning dashboard.
+      security-events: write
+      # Needed to publish results and get a badge (see publish_results below).
+      id-token: write
+      # Uncomment the permissions below if installing in a private repository.
+      # contents: read
+      # actions: read
+
+    steps:
+      - name: "Checkout code"
+        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+        with:
+          persist-credentials: false
+
+      - name: "Run analysis"
+        uses: ossf/scorecard-action@ea651e62978af7915d09fe2e282747c798bf2dab # v2.4.1
+        with:
+          results_file: results.sarif
+          results_format: sarif
+          # (Optional) Read-only 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 }}
+
+          # Public repositories:
+          #   - Publish results to OpenSSF REST API for easy access by consumers
+          #   - Allows the repository to include the Scorecard badge.
+          #   - See https://github.com/ossf/scorecard-action#publishing-results.
+          # For private repositories:
+          #   - `publish_results` will always be set to `false`, regardless
+          #     of the value entered here.
+          publish_results: true
+
+      # 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@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4.6.2
+        with:
+          name: SARIF file
+          path: results.sarif
+          retention-days: 5
+
+      # Upload the results to GitHub's code scanning dashboard.
+      - name: "Upload to code-scanning"
+        uses: github/codeql-action/upload-sarif@959cbb7472c4d4ad70cdfe6f4976053fe48ab394 # v2.1.27
+        with:
+          sarif_file: results.sarif
diff --git a/.github/workflows/spec_guards.yml b/.github/workflows/spec_guards.yml
new file mode 100644
index 0000000000..4521195a2b
--- /dev/null
+++ b/.github/workflows/spec_guards.yml
@@ -0,0 +1,71 @@
+name: Rubyspec Version Guards Check
+
+on:
+  push:
+    paths:
+      - 'spec/**'
+      - '!spec/*.md'
+  pull_request:
+    paths:
+      - 'spec/**'
+      - '!spec/*.md'
+  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:
+  rubyspec:
+    name: Rubyspec
+
+    runs-on: ubuntu-22.04
+
+    if: >-
+      ${{!(false
+      || contains(github.event.head_commit.message, '[DOC]')
+      || contains(github.event.head_commit.message, 'Document')
+      || contains(github.event.pull_request.title, '[DOC]')
+      || contains(github.event.pull_request.title, 'Document')
+      || contains(github.event.pull_request.labels.*.name, 'Document')
+      || (github.event_name == 'push' && github.actor == '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-3.1
+          - ruby-3.2
+
+    steps:
+      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+
+      - uses: ruby/setup-ruby@13e7a03dc3ac6c3798f4570bfead2aed4d96abfb # v1.244.0
+        with:
+          ruby-version: ${{ matrix.ruby }}
+          bundler: none
+
+      - run: gem install webrick
+
+      - run: ruby ../mspec/bin/mspec
+        working-directory: spec/ruby
+        env:
+          CHECK_LEAKS: true
+      - uses: ruby/action-slack@0bd85c72233cdbb6a0fe01d37aaeff1d21b5fce1 # v3.2.1
+        with:
+          payload: |
+            {
+              "ci": "GitHub Actions",
+              "env": "${{ github.workflow }} / rubyspec @ ${{ matrix.ruby }}",
+              "url": "https://github.com/${{ github.repository }}/actions/runs/${{ github.run_id }}",
+              "commit": "${{ github.sha }}",
+              "branch": "${{ github.ref_name }}"
+            }
+        env:
+          SLACK_WEBHOOK_URL: ${{ secrets.SIMPLER_ALERTS_URL }} # ruby-lang slack: ruby/simpler-alerts-bot
+        if: ${{ failure() }}
diff --git a/.github/workflows/ubuntu.yml b/.github/workflows/ubuntu.yml
index e1cfa2d22f..4fbca1170e 100644
--- a/.github/workflows/ubuntu.yml
+++ b/.github/workflows/ubuntu.yml
@@ -1,79 +1,146 @@
-name: ubuntu
+name: Ubuntu
 on:
   push:
-    branches:
-      - master
+    paths-ignore:
+      - 'doc/**'
+      - '**/man'
+      - '**.md'
+      - '**.rdoc'
+      - '**/.document'
   pull_request:
-    branches:
-      - '*'
+    paths-ignore:
+      - 'doc/**'
+      - '**/man'
+      - '**.md'
+      - '**.rdoc'
+      - '**/.document'
+  merge_group:
+    paths-ignore:
+      - 'doc/**'
+      - '**/man'
+      - '**.md'
+      - '**.rdoc'
+      - '**/.document'
+
+concurrency:
+  group: ${{ github.workflow }} / ${{ startsWith(github.event_name, 'pull') && github.ref_name || github.sha }}
+  cancel-in-progress: ${{ startsWith(github.event_name, 'pull') }}
+
+permissions:
+  contents: read
+
 jobs:
-  latest:
-    runs-on: ubuntu-latest
+  make:
     strategy:
       matrix:
-        test_task: [ "check", "test-bundler", "test-bundled-gems" ]
+        # main variables included in the job name
+        test_task: [check]
+        configure: [cppflags=-DRUBY_DEBUG] # default to use more assertions
+        arch: ['']
+        # specify all jobs with `include` to avoid testing duplicated things
+        include:
+          - test_task: check
+          - test_task: check
+            arch: i686
+            configure: '' # test without -DRUBY_DEBUG as well
+          - test_task: check
+            configure: "--enable-shared --enable-load-relative"
+          - test_task: test-all TESTS=--repeat-count=2
+          - 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: ${{ !contains(github.event.head_commit.message, '[DOC]') && !contains(github.event.pull_request.labels.*.name, 'Documentation') }}
     steps:
+      - run: mkdir build
+        working-directory:
+      - name: Set ENV
+        run: |
+          echo "GNUMAKEFLAGS=-j$((1 + $(nproc --all)))" >> $GITHUB_ENV
       - name: Install libraries
+        env:
+          arch: ${{matrix.arch}}
         run: |
           set -x
-          sudo sed /etc/apt/sources.list -e "s/^# deb-src/deb-src/g" -i
-          sudo apt-get update
-          sudo apt-get install ruby2.5
-          sudo apt-get build-dep ruby2.5
-      # Not using official actions/checkout because it's unstable and sometimes doesn't work for a fork.
-      - name: Checkout ruby/ruby
-        run: git clone --depth=50 https://github.com/ruby/ruby . && git reset --hard "$GITHUB_SHA"
-        if: github.event_name == 'push'
-      - name: Checkout a pull request
-        run: git clone --depth=50 "--branch=$GITHUB_BRANCH" "https://github.com/${GITHUB_REPO}" . && git reset --hard "$GITHUB_REV"
-        env:
-          GITHUB_REV: ${{ github.event.pull_request.head.sha }}
-          GITHUB_BRANCH: ${{ github.event.pull_request.head.ref }}
-          GITHUB_REPO: ${{ github.event.pull_request.head.repo.full_name }}
-        if: github.event_name == 'pull_request'
+          arch=${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@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+        with:
+          path: src
+      - uses: actions/cache@5a3ec84eff668545956fd18022155c47e93e2684 # v4.2.3
+        with:
+          path: src/.downloaded-cache
+          key: downloaded-cache
       - name: Fixed world writable dirs
         run: |
-          chmod go-w $HOME
+          chmod -v go-w $HOME $HOME/.config
           sudo chmod -R go-w /usr/share
-      - name: Set ENV
-        run: |
-          echo '##[set-env name=JOBS]'-j$((1 + $(nproc --all)))
-      - run: autoconf
-      - name: configure
-        run: ./configure -C --disable-install-doc
-      - run: make $JOBS
-      - name: Tests
-        run: make -s ${{ matrix.test_task }}
+          sudo bash -c 'IFS=:; for d in '"$PATH"'; do chmod -v go-w $d; done' || :
+      - run: ./autogen.sh
+        working-directory: src
+      - name: Run configure
         env:
-          TESTOPTS: "$JOBS -q --tty=no"
-          MSPECOPT: "-ff" # not using `-j` because sometimes `mspec -j` silently dies
-        if: matrix.test_task != 'test-bundled-gems' && !contains(github.event.head_commit.message, '[ci skip]')
-      # test-bundled-gems is separated for marking `continue-on-error` because it randomly fails.
-      - name: Tests (test-bundled-gems)
-        run: make -s ${{ matrix.test_task }}
+          arch: ${{matrix.arch}}
+        run: >-
+          $SETARCH ../src/configure -C --disable-install-doc ${{ matrix.configure }}
+          ${arch:+--target=$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 ./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: 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
         env:
-          TESTOPTS: "-q --tty=no"
-        continue-on-error: true
-        if: matrix.test_task == 'test-bundled-gems' && !contains(github.event.head_commit.message, '[ci skip]')
-      - name: Leaked Globals
-        run: make -s leaked-globals
-      - name: Debug GitHub context
-        run: echo "$GITHUB_CONTEXT"
+          RUBY_TESTOPTS: "-q --tty=no"
+          TESTS: ${{ matrix.test_task == 'check' && matrix.skipped_tests || '' }}
+          TEST_BUNDLED_GEMS_ALLOW_FAILURES: ""
+          PRECHECK_BUNDLED_GEMS: "no"
+      - name: make skipped tests
+        run: |
+          $SETARCH make -s test-all TESTS=`echo "$TESTS" | sed 's| |$$/ -n/|g;s|^|-n/|;s|$|$$/|'`
         env:
-          GITHUB_CONTEXT: ${{ toJson(github) }}
-        if: failure() && github.event_name == 'push'
-      - uses: k0kubun/action-slack@v2.0.0
+          GNUMAKEFLAGS: ""
+          RUBY_TESTOPTS: "-v --tty=no"
+          TESTS: ${{ matrix.skipped_tests }}
+        if: ${{ matrix.test_task == 'check' && matrix.skipped_tests != '' }}
+        continue-on-error: ${{ matrix.continue-on-skipped_tests || false }}
+      - uses: ruby/action-slack@0bd85c72233cdbb6a0fe01d37aaeff1d21b5fce1 # v3.2.1
         with:
           payload: |
             {
-              "attachments": [{
-                "text": "${{ job.status}}: <https://github.com/${{ github.repository }}/commit/${{ github.sha }}/checks|${{ github.workflow }} / ${{ matrix.test_task }}> " +
-                        "(<https://github.com/${{ github.repository }}/commit/${{ github.sha }}|" + "${{ github.sha }}".substring(0, 10) + ">) " +
-                        "of ${{ github.repository }}@" + "${{ github.ref }}".split('/').reverse()[0] + " by ${{ github.event.head_commit.committer.name }}",
-                "color": "danger"
-              }]
+              "ci": "GitHub Actions",
+              "env": "${{ 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 }}"
             }
         env:
-          SLACK_WEBHOOK_URL: ${{ secrets.SLACK_WEBHOOK_URL }}
-        if: failure() && github.event_name == 'push'
+          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/wasm.yml b/.github/workflows/wasm.yml
new file mode 100644
index 0000000000..27920b5821
--- /dev/null
+++ b/.github/workflows/wasm.yml
@@ -0,0 +1,146 @@
+name: WebAssembly
+on:
+  push:
+    paths-ignore:
+      - 'doc/**'
+      - '**/man'
+      - '**.md'
+      - '**.rdoc'
+      - '**/.document'
+  pull_request:
+    paths-ignore:
+      - 'doc/**'
+      - '**/man'
+      - '**.md'
+      - '**.rdoc'
+      - '**/.document'
+  merge_group:
+    paths-ignore:
+      - 'doc/**'
+      - '**/man'
+      - '**.md'
+      - '**.rdoc'
+      - '**/.document'
+
+concurrency:
+  group: ${{ github.workflow }} / ${{ startsWith(github.event_name, 'pull') && github.ref_name || github.sha }}
+  cancel-in-progress: ${{ startsWith(github.event_name, 'pull') }}
+
+permissions:  # added using https://github.com/step-security/secure-workflows
+  contents: read
+
+jobs:
+  make:
+    strategy:
+      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" }
+#         # -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" }
+      fail-fast: false
+    env:
+      RUBY_TESTOPTS: '-q --tty=no'
+      GITPULLOPTIONS: --no-tags origin ${{github.ref}}
+      WASI_SDK_VERSION_MAJOR: 14
+      WASI_SDK_VERSION_MINOR: 0
+      BINARYEN_VERSION: 109
+      WASMTIME_VERSION: v0.33.0
+    runs-on: ubuntu-22.04
+    if: ${{ !contains(github.event.head_commit.message, '[DOC]') && !contains(github.event.pull_request.labels.*.name, 'Documentation') }}
+    steps:
+      - run: mkdir build
+        working-directory:
+      - name: git config
+        run: |
+          git config --global advice.detachedHead 0
+          git config --global init.defaultBranch garbage
+      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+        with:
+          path: src
+      - name: Install libraries
+        run: |
+          set -ex
+          sudo apt-get update -q || :
+          sudo apt-get install --no-install-recommends -q -y ruby bison make autoconf git wget
+
+          wasi_sdk_deb="wasi-sdk_${WASI_SDK_VERSION_MAJOR}.${WASI_SDK_VERSION_MINOR}_amd64.deb"
+          wget "https://github.com/WebAssembly/wasi-sdk/releases/download/wasi-sdk-${WASI_SDK_VERSION_MAJOR}/${wasi_sdk_deb}"
+          sudo dpkg -i "$wasi_sdk_deb"
+          rm -f "$wasi_sdk_deb"
+
+          mkdir build-sdk
+          pushd build-sdk
+
+          wasmtime_url="https://github.com/bytecodealliance/wasmtime/releases/download/${WASMTIME_VERSION}/wasmtime-${WASMTIME_VERSION}-x86_64-linux.tar.xz"
+          wget -O - "$wasmtime_url" | tar xJf -
+          sudo ln -fs "$PWD/wasmtime-${WASMTIME_VERSION}-x86_64-linux/wasmtime" /usr/local/bin/wasmtime
+
+          binaryen_tarball="binaryen-version_${BINARYEN_VERSION}-x86_64-linux.tar.gz"
+          binaryen_url="https://github.com/WebAssembly/binaryen/releases/download/version_${BINARYEN_VERSION}/${binaryen_tarball}"
+          wget -O - "$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" >> $GITHUB_ENV
+      - run: ./autogen.sh
+        working-directory: src
+
+      - uses: ruby/setup-ruby@13e7a03dc3ac6c3798f4570bfead2aed4d96abfb # v1.244.0
+        with:
+          ruby-version: '3.0'
+          bundler: none
+
+      - name: Download config.guess with wasi version
+        run: |
+          rm tool/config.guess tool/config.sub
+          ruby tool/downloader.rb -d tool -e gnu config.guess config.sub
+        working-directory: src
+
+      - name: Run configure
+        run: |
+          ../src/configure \
+            --host wasm32-unknown-wasi \
+            --with-static-linked-ext \
+            LDFLAGS=" \
+              -Xlinker --stack-first \
+              -Xlinker -z -Xlinker stack-size=16777216 \
+            " \
+            optflags="${{ matrix.entry.optflags }}" \
+            debugflags="${{ matrix.entry.debugflags }}" \
+            wasmoptflags="${{ matrix.entry.wasmoptflags }} ${{ matrix.entry.debugflags }}"
+
+      # miniruby may not be built when cross-compling
+      - run: make mini ruby
+      - name: Run basictest
+        run: wasmtime run ./../build/miniruby --mapdir /::./ -- basictest/test.rb
+        working-directory: src
+      - name: Run bootstraptest (no thread)
+        run: |
+          NO_THREAD_TESTS="$(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@0bd85c72233cdbb6a0fe01d37aaeff1d21b5fce1 # v3.2.1
+        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:
+          SLACK_WEBHOOK_URL: ${{ secrets.SIMPLER_ALERTS_URL }} # ruby-lang slack: ruby/simpler-alerts-bot
+        if: ${{ failure() && github.event_name == 'push' }}
+
+defaults:
+  run:
+    working-directory: build
diff --git a/.github/workflows/windows.yml b/.github/workflows/windows.yml
index 3987153ae3..c2bd4881c2 100644
--- a/.github/workflows/windows.yml
+++ b/.github/workflows/windows.yml
@@ -1,70 +1,149 @@
-name: windows
+name: Windows
 on:
   push:
-    branches:
-      - master
+    paths-ignore:
+      - 'doc/**'
+      - '**/man'
+      - '**.md'
+      - '**.rdoc'
+      - '**/.document'
   pull_request:
-    branches:
-      - '*'
+    paths-ignore:
+      - 'doc/**'
+      - '**/man'
+      - '**.md'
+      - '**.rdoc'
+      - '**/.document'
+  merge_group:
+    paths-ignore:
+      - 'doc/**'
+      - '**/man'
+      - '**.md'
+      - '**.rdoc'
+      - '**/.document'
+
+concurrency:
+  group: ${{ github.workflow }} / ${{ startsWith(github.event_name, 'pull') && github.ref_name || github.sha }}
+  cancel-in-progress: ${{ startsWith(github.event_name, 'pull') }}
+
+permissions:
+  contents: read
+
 jobs:
-  latest:
+  make:
     strategy:
       matrix:
-        os: [windows-2016, windows-2019]
-        vs: [2017, 2019]
-        test_task: [test]
-        exclude:
-          - os: windows-2016
-            vs: 2019
-          - os: windows-2019
-            vs: 2017
+        include:
+          - vs: 2022
+            vcvers: -vcvars_ver=14.2
       fail-fast: false
-    runs-on: ${{ matrix.os }}
+    runs-on: windows-${{ matrix.vs }}
+    if: ${{ !contains(github.event.head_commit.message, '[DOC]') && !contains(github.event.pull_request.labels.*.name, 'Documentation') }}
+    name: VisualStudio ${{ matrix.vs }}
+    env:
+      GITPULLOPTIONS: --no-tags origin ${{github.ref}}
+      PATCH: C:\msys64\usr\bin\patch.exe
+      OS_VER: windows-${{ matrix.vs }}
     steps:
+      - run: md build
+        working-directory:
+      - uses: msys2/setup-msys2@61f9e5e925871ba6c9e3e8da24ede83ea27fa91f # v2.27.0
+        id: setup-msys2
+        with:
+          update: true
+          install: bison 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@5a3ec84eff668545956fd18022155c47e93e2684 # v4.2.3
+        with:
+          path: C:\vcpkg\installed
+          key: ${{ runner.os }}-vcpkg-installed-windows-${{ matrix.vs }}-${{ github.sha }}
+          restore-keys: |
+            ${{ runner.os }}-vcpkg-installed-windows-${{ matrix.vs }}-
+            ${{ runner.os }}-vcpkg-installed-windows-
       - name: Install libraries with vcpkg
         run: |
-          vcpkg --triplet x64-windows install %dependencies% || (
-            sleep 4 && vcpkg --triplet x64-windows install %dependencies%
-          ) || (
-            sleep 25 && vcpkg --triplet x64-windows install %dependencies%
-          )
-        env:
-          dependencies: openssl readline zlib
-      - name: Install libraries with chocolatey
-        run: choco install winflexbison3
-      # Not using official actions/checkout because it's unstable and sometimes doesn't work for a fork.
-      - name: Checkout ruby/ruby
-        run: git clone --depth=50 https://github.com/ruby/ruby . && git reset --hard ${{ github.sha }}
-        if: github.event_name == 'push'
-      - name: Checkout a pull request
-        run: git clone --depth=50 --branch=${{ github.event.pull_request.head.ref }} https://github.com/${{ github.event.pull_request.head.repo.full_name }} . && git reset --hard ${{ github.event.pull_request.head.sha }}
-        if: github.event_name == 'pull_request'
-      - name: configure
+          iex "& {$(irm get.scoop.sh)} -RunAsAdmin"
+          Join-Path (Resolve-Path ~).Path "scoop\shims" >> $Env:GITHUB_PATH
+          scoop install cmake@3.31.6
+          vcpkg --triplet x64-windows install libffi libyaml openssl readline zlib
+        shell:
+          pwsh
+      - name: git config
         run: |
-          call "C:\Program Files (x86)\Microsoft Visual Studio\${{ matrix.vs }}\Enterprise\VC\Auxiliary\Build\vcvars64.bat"
-          win32/configure.bat --disable-install-doc --without-ext=+,dbm,gdbm --enable-bundled-libffi --with-opt-dir=C:/vcpkg/installed/x64-windows
-      - name: nmake
+          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@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+        with:
+          path: src
+      - uses: actions/cache@5a3ec84eff668545956fd18022155c47e93e2684 # v4.2.3
+        with:
+          path: src/.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
+        # msys2/setup-msys2 installs MSYS2 to D:/a/_temp/msys64/usr/bin
         run: |
-          call "C:\Program Files (x86)\Microsoft Visual Studio\${{ matrix.vs }}\Enterprise\VC\Auxiliary\Build\vcvars64.bat"
-          set YACC=win_bison
-          nmake up
-          nmake
-      - name: nmake test
+          set Path=D:/a/_temp/msys64/usr/bin;%Path%
+          if not "%VCVARS%" == "" goto :vcset
+            set VCVARS="C:\Program Files (x86)\Microsoft Visual Studio\${{ matrix.vs }}\Enterprise\VC\Auxiliary\Build\vcvars64.bat"
+            if not exist %VCVARS% set VCVARS="C:\Program Files\Microsoft Visual Studio\${{ matrix.vs }}\Enterprise\VC\Auxiliary\Build\vcvars64.bat"
+          :vcset
+          set | C:\msys64\usr\bin\sort > old.env
+          call %VCVARS% ${{ matrix.vcvers || ''}}
+          set TMP=%USERPROFILE%\AppData\Local\Temp
+          set TEMP=%USERPROFILE%\AppData\Local\Temp
+          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%
+          del *.env
+      - name: compiler version
+        run: cl
+      - name: link libraries
         run: |
-          call "C:\Program Files (x86)\Microsoft Visual Studio\${{ matrix.vs }}\Enterprise\VC\Auxiliary\Build\vcvars64.bat"
-          nmake ${{ matrix.test_task }}
-        if: "!contains(github.event.head_commit.message, '[ci skip]')"
-      - uses: k0kubun/action-slack@v2.0.0
+          for %%I in (C:\vcpkg\installed\x64-windows\bin\*.dll) do (
+            if not %%~nI == readline mklink %%~nxI %%I
+          )
+          for %%I in (libcrypto-1_1-x64 libssl-1_1-x64) do (
+            ren c:\Windows\System32\%%I.dll %%I.dll_
+          )
+      - name: Configure
+        run: >-
+          ../src/win32/configure.bat --disable-install-doc
+          --with-opt-dir=C:/vcpkg/installed/x64-windows
+      - run: nmake incs
+      - run: nmake extract-extlibs
+      - run: nmake
+        env:
+          YACC: bison.exe
+      - run: nmake test
+        timeout-minutes: 5
+      - run: nmake test-spec
+        timeout-minutes: 10
+      - run: nmake test-all
+        env:
+          RUBY_TESTOPTS: -j${{env.TEST_JOBS}} --job-status=normal
+        timeout-minutes: 60
+      - uses: ruby/action-slack@0bd85c72233cdbb6a0fe01d37aaeff1d21b5fce1 # v3.2.1
         with:
           payload: |
             {
-              "attachments": [{
-                "text": "${{ job.status}}: <https://github.com/${{ github.repository }}/commit/${{ github.sha }}/checks|${{ github.workflow }} / ${{ matrix.test_task }}> " +
-                        "(<https://github.com/${{ github.repository }}/commit/${{ github.sha }}|" + "${{ github.sha }}".substring(0, 10) + ">) " +
-                        "of ${{ github.repository }}@" + "${{ github.ref }}".split('/').reverse()[0] + " by ${{ github.event.head_commit.committer.name }}",
-                "color": "danger"
-              }]
+              "ci": "GitHub Actions",
+              "env": "VS${{ matrix.vs }} / ${{ matrix.test_task || 'check' }}",
+              "url": "https://github.com/${{ github.repository }}/actions/runs/${{ github.run_id }}",
+              "commit": "${{ github.sha }}",
+              "branch": "${{ github.ref_name }}"
             }
         env:
-          SLACK_WEBHOOK_URL: ${{ secrets.SLACK_WEBHOOK_URL }}
-        if: failure() && github.event_name == 'push'
+          SLACK_WEBHOOK_URL: ${{ secrets.SIMPLER_ALERTS_URL }} # ruby-lang slack: ruby/simpler-alerts-bot
+        if: ${{ failure() && github.event_name == 'push' }}
+
+defaults:
+  run:
+    working-directory: build
+    shell: cmd
diff --git a/.github/workflows/yjit-ubuntu.yml b/.github/workflows/yjit-ubuntu.yml
new file mode 100644
index 0000000000..0b7b9046e9
--- /dev/null
+++ b/.github/workflows/yjit-ubuntu.yml
@@ -0,0 +1,170 @@
+name: YJIT Ubuntu
+on:
+  push:
+    paths-ignore:
+      - 'doc/**'
+      - '**/man'
+      - '**.md'
+      - '**.rdoc'
+      - '**/.document'
+  pull_request:
+    paths-ignore:
+      - 'doc/**'
+      - '**/man'
+      - '**.md'
+      - '**.rdoc'
+      - '**/.document'
+  merge_group:
+    paths-ignore:
+      - 'doc/**'
+      - '**/man'
+      - '**.md'
+      - '**.rdoc'
+      - '**/.document'
+
+concurrency:
+  group: ${{ github.workflow }} / ${{ startsWith(github.event_name, 'pull') && github.ref_name || github.sha }}
+  cancel-in-progress: ${{ startsWith(github.event_name, 'pull') }}
+
+permissions:
+  contents: read
+
+jobs:
+  cargo:
+    name: Rust cargo test
+    # GitHub Action's image seems to already contain a Rust 1.58.0.
+    runs-on: ubuntu-22.04
+    steps:
+      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+      # 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
+  make:
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - test_task: 'yjit-bindgen'
+            hint: 'To fix: use patch in logs'
+            configure: '--with-gcc=clang-14 --enable-yjit=dev'
+            libclang_path: '/usr/lib/llvm-14/lib/libclang.so.1'
+
+          - test_task: "check"
+            # YJIT should be automatically built in release mode on x86-64 Linux with rustc present
+            #configure: "--enable-yjit RUSTC='rustc +1.58.0'"
+            configure: "RUSTC='rustc +1.58.0'"
+            rust_version: "1.58.0"
+
+          - 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: "test-all TESTS=--repeat-count=2"
+            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}}
+      RUN_OPTS: ${{ matrix.yjit_opts }}
+      YJIT_BENCH_OPTS: ${{ matrix.yjit_bench_opts }}
+      RUBY_DEBUG: ci
+      BUNDLE_JOBS: 8 # for yjit-bench
+    runs-on: ubuntu-22.04
+    if: ${{ !contains(github.event.head_commit.message, '[DOC]') && !contains(github.event.pull_request.labels.*.name, 'Documentation') }}
+    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: 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@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+        with:
+          path: src
+      - uses: actions/cache@5a3ec84eff668545956fd18022155c47e93e2684 # v4.2.3
+        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)))" >> $GITHUB_ENV
+      - run: ./autogen.sh
+        working-directory: src
+      - name: Run configure
+        run: ../src/configure -C --disable-install-doc --prefix=$(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: |
+          ./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
+      # Check that the binary was built with YJIT
+      - name: Check YJIT enabled
+        run: ./miniruby --yjit -v | grep "+YJIT"
+      - 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"
+          LIBCLANG_PATH: ${{ matrix.libclang_path }}
+        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}"
+        env:
+          BASE_REPO: ${{ github.event.pull_request.base.repo.full_name }}
+          BASE_SHA: ${{ github.event.pull_request.base.sha }}
+        if: ${{ matrix.test_task == 'yjit-bench' && startsWith(github.event_name, 'pull') }}
+      - uses: ruby/action-slack@0bd85c72233cdbb6a0fe01d37aaeff1d21b5fce1 # v3.2.1
+        with:
+          payload: |
+            {
+              "ci": "GitHub Actions",
+              "env": "${{ 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:
+          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/.gitignore b/.gitignore
index fe7c04823b..99d32a1825 100644
--- a/.gitignore
+++ b/.gitignore
@@ -10,23 +10,26 @@
 *.dylib
 *.elc
 *.i
+*.ii
 *.inc
 *.log
 *.o
+*.o.tmp
 *.obj
 *.old
 *.orig
 *.pch
 *.pdb
+*.rbinc
 *.rej
 *.s
 *.sav
 *.sl
 *.so
+*.so.*
 *.swp
 *.yarb
 *~
-.*-*
 .*.list
 .*.time
 .DS_Store
@@ -37,6 +40,7 @@
 .ppack
 .svn
 .time
+.ruby-version
 Makefile
 cygruby*.def
 extconf.h
@@ -56,6 +60,8 @@ lcov*.info
 /*.pc
 /*.rc
 /*_prelude.c
+/.downloaded-cache
+/.top-enc.mk
 /build*/
 /COPYING.LIB
 /ChangeLog
@@ -116,14 +122,17 @@ lcov*.info
 /rename2.h
 /repack
 /revision.h
+/revision.tmp
 /riscos
 /rubicon
 /ruby
 /ruby-runner
 /ruby-runner.h
 /ruby-man.rd.gz
+/rubyspec_temp
 /run.gdb
 /sizes.c
+/static-ruby
 /test.rb
 /test-coverage.dat
 /tmp
@@ -138,6 +147,8 @@ lcov*.info
 
 /bin/*.exe
 /bin/*.dll
+/bin/goruby
+/bin/ruby
 
 # /benchmark/
 /benchmark/bm_require.data
@@ -169,11 +180,17 @@ lcov*.info
 /ext/configure-ext.mk
 /ext/*/exts.mk
 
+# /ext/-test-/cxxanyargs
+/ext/-test-/cxxanyargs/failure*.failed
+
 # /ext/-test-/win32/dln/
 /ext/-test-/win32/dln/dlntest.dll
 /ext/-test-/win32/dln/dlntest.exp
 /ext/-test-/win32/dln/dlntest.lib
 
+# /ext/-test-/gems
+/ext/-test-/gems
+
 # /ext/etc/
 /ext/etc/constdefs.h
 
@@ -186,6 +203,7 @@ lcov*.info
 
 # /ext/ripper/
 /ext/ripper/eventids1.c
+/ext/ripper/.eventids2-check
 /ext/ripper/eventids2table.c
 /ext/ripper/ripper.*
 /ext/ripper/ids1
@@ -205,6 +223,9 @@ lcov*.info
 /lib/ruby/[1-9]*.*
 /lib/ruby/vendor_ruby
 
+# /misc/
+/misc/**/__pycache__
+
 # /spec/bundler
 /.rspec_status
 
@@ -216,6 +237,14 @@ lcov*.info
 /win32/*.ico
 
 # MJIT
-/rb_mjit_header.h
-/mjit_config.h
 /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
+
+# /wasm/
+/wasm/tests/*.wasm
diff --git a/.indent.pro b/.indent.pro
index 6a207a0554..1d61cbcad1 100644
--- a/.indent.pro
+++ b/.indent.pro
@@ -2,12 +2,15 @@
 -nbbb
 -nbc
 -br
+-brs
 -nbs
 -ncdb
--ce
--cli0.5
+-nce
+-cdw
+-cli2
+-cbi2
 -ndj
--ei
+-ncs
 -nfc1
 -i4
 -l120
@@ -16,6 +19,14 @@
 -psl
 -sc
 -sob
+-sbi4
+-nut
+-par
 
 -TID
 -TVALUE
+-Tst_data_t
+-Tst_index_t
+-Tst_table
+-Trb_data_type_t
+-TFILE
diff --git a/.rdoc_options b/.rdoc_options
new file mode 100644
index 0000000000..760507c7a2
--- /dev/null
+++ b/.rdoc_options
@@ -0,0 +1,4 @@
+---
+page_dir: doc
+main_page: README.md
+title: Documentation for Ruby development version
diff --git a/.travis.yml b/.travis.yml
deleted file mode 100644
index 37e20032f7..0000000000
--- a/.travis.yml
+++ /dev/null
@@ -1,493 +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.
-
-# This is  a Travis-CI  build configuration file.   The list  of configurations
-# available is located in
-#
-#     http://about.travis-ci.org/docs/user/build-configuration/
-#
-# and as Ruby itself is a project written in C language,
-#
-#     http://about.travis-ci.org/docs/user/languages/c/
-#
-# is also a good place to look at.
-
-language: c
-
-os: linux
-
-dist: xenial
-
-git:
-  quiet: true
-
-cache:
-  ccache: true
-  directories:
-    - $HOME/config_2nd
-    - $HOME/.downloaded-cache
-
-env:
-  global:
-    # Reset timestamps early
-    - _=$(touch NEWS && find . -type f -exec touch -r NEWS {} +)
-    - CONFIGURE_TTY=no
-    - CCACHE_COMPILERCHECK=none
-    - CCACHE_NOCOMPRESS=1
-    - CCACHE_MAXSIZE=512Mi
-    - NPROC="`nproc`"
-    # JOBS and SETARCH are overridden when necessary; see below.
-    - JOBS=-j$((1+${NPROC}))
-    - SETARCH=
-    - RUBY_PREFIX=/tmp/ruby-prefix
-    - GEMS_FOR_TEST='timezone tzinfo'
-    - UPDATE_UNICODE="UNICODE_FILES=. UNICODE_PROPERTY_FILES=. UNICODE_AUXILIARY_FILES=. UNICODE_EMOJI_FILES=."
-    # https://github.com/travis-ci/travis-build/blob/e411371dda21430a60f61b8f3f57943d2fe4d344/lib/travis/build/bash/travis_apt_get_options.bash#L7
-    - travis_apt_get_options='--allow-downgrades --allow-remove-essential --allow-change-held-packages'
-    - travis_apt_get_options="-yq --no-install-suggests --no-install-recommends $travis_apt_get_options"
-
-.org.ruby-lang.ci.matrix-definitions:
-
-  - &cron-only
-    if: (type = cron) AND (branch = master) AND (fork = false)
-
-  - &make-test-only
-    script:
-      - $SETARCH make -s test TESTOPTS="${TESTOPTS=$JOBS -q --tty=no}"
-
-  - &gcc-8
-    compiler: gcc-8
-    # # Not using addon to control retries
-    # addons:
-    #   apt:
-    #     sources:
-    #       - ubuntu-toolchain-r-test
-    before_install:
-      - tool/travis_retry.sh sudo -E apt-add-repository -y "ppa:ubuntu-toolchain-r/test"
-      - tool/travis_retry.sh sudo bash -c "rm -rf '${TRAVIS_ROOT}/var/lib/apt/lists/'* && exec apt-get update -yq"
-      - |-
-        ${BEFORE_INSTALL}
-        tool/travis_retry.sh sudo -E apt-get $travis_apt_get_options install \
-          gcc-8 \
-          libffi-dev \
-          libgdbm-dev \
-          libgmp-dev \
-          libjemalloc-dev \
-          libncurses5-dev \
-          libncursesw5-dev \
-          libreadline6-dev \
-          libssl-dev \
-          libyaml-dev \
-          openssl \
-          valgrind \
-          zlib1g-dev
-
-  - &clang-8
-    compiler: clang-8
-    addons:
-      apt:
-        # Not doing this manually unlike other sources, because it has been stable.
-        sources:
-          - llvm-toolchain-xenial-8
-        config:
-          retries: true
-    before_install:
-      - tool/travis_retry.sh sudo bash -c "rm -rf '${TRAVIS_ROOT}/var/lib/apt/lists/'* && exec apt-get update -yq"
-      - |-
-        tool/travis_retry.sh sudo -E apt-get $travis_apt_get_options install \
-          clang-8 \
-          llvm-8-tools \
-          libffi-dev \
-          libgdbm-dev \
-          libgmp-dev \
-          libjemalloc-dev \
-          libncurses5-dev \
-          libncursesw5-dev \
-          libreadline6-dev \
-          libssl-dev \
-          libyaml-dev \
-          openssl \
-          valgrind \
-          zlib1g-dev
-
-  # --------
-
-  - &x86_64-linux
-    name: x86_64-linux
-    <<: *gcc-8
-    env:
-      - TEST_MJIT_SYMBOLS=1 # detect exports missing for MJIT
-
-  - &jemalloc
-    name: --with-jemalloc
-    <<: *gcc-8
-    <<: *cron-only
-    env:
-      - CONFIG_FLAG='--with-gmp --with-jemalloc --with-valgrind'
-
-  - &assertions
-    name: RUBY_DEBUG=1
-    <<: *gcc-8
-    #<<: *cron-only
-    <<: *make-test-only
-    env:
-      - GEMS_FOR_TEST=
-      - cppflags='-DRUBY_DEBUG -DVM_CHECK_MODE=1 -DTRANSIENT_HEAP_CHECK_MODE -DRGENGC_CHECK_MODE -DENC_DEBUG'
-
-  - &VM_CHECK_MODE
-    name: VM_CHECK_MODE=3
-    <<: *gcc-8
-    <<: *cron-only
-    <<: *make-test-only
-    env:
-      - GEMS_FOR_TEST=
-      - cppflags=-DVM_CHECK_MODE=0x0003
-
-  - &SUPPORT_JOKE
-    name: SUPPORT_JOKE
-    <<: *gcc-8
-    <<: *cron-only
-    <<: *make-test-only
-    env:
-      - BEFORE_INSTALL="sed vm_opts.h -e 's/OPT_SUPPORT_JOKE *0/OPT_SUPPORT_JOKE 1/' -i"
-
-  - &WITH_COROUTINE_UCONTEXT
-    name: COROUTINE=ucontext
-    <<: *gcc-8
-    <<: *cron-only
-    env:
-      - CONFIG_FLAG='--with-coroutine=ucontext'
-
-  - &WITH_COROUTINE_COPY
-    name: COROUTINE=copy
-    <<: *gcc-8
-    <<: *cron-only
-    env:
-      - CONFIG_FLAG='--with-coroutine=copy'
-
-  - &TOKEN_THREADED_CODE
-    name: TOKEN_THREADED_CODE
-    <<: *gcc-8
-    <<: *cron-only
-    <<: *make-test-only
-    env:
-      - GEMS_FOR_TEST=
-      - cppflags=-DOPT_THREADED_CODE=1
-
-  - &CALL_THREADED_CODE
-    name: CALL_THREADED_CODE
-    <<: *gcc-8
-    <<: *cron-only
-    <<: *make-test-only
-    env:
-      - GEMS_FOR_TEST=
-      - cppflags=-DOPT_THREADED_CODE=2
-
-  - &NO_THREADED_CODE
-    name: NO_THREADED_CODE
-    <<: *gcc-8
-    <<: *cron-only
-    <<: *make-test-only
-    env:
-      - GEMS_FOR_TEST=
-      - cppflags=-DOPT_THREADED_CODE=3
-
-  - &ASAN
-    name: -fsanitize=address
-    <<: *clang-8
-    #<<: *cron-only
-    <<: *make-test-only
-    env:
-      - GEMS_FOR_TEST=
-      - ASAN_OPTIONS=detect_leaks=0
-      - cflags='-U_FORTIFY_SOURCE -march=native -fsanitize=address -fno-omit-frame-pointer -fPIC'
-      - debugflags=-ggdb3
-      - optflags=-O1
-      - LD=clang-8
-      - LDFLAGS='-fsanitize=address -fPIC'
-      - CONFIG_FLAG='--with-out-ext=openssl --without-gmp --without-jemalloc --without-valgrind'
-
-  - &MSAN
-    name: -fsanitize=memory
-    <<: *clang-8
-    #<<: *cron-only
-    <<: *make-test-only
-    env:
-      - GEMS_FOR_TEST=
-      - cflags='-U_FORTIFY_SOURCE -fsanitize=memory -fsanitize-memory-track-origins=2 -fno-omit-frame-pointer -fPIC'
-      - optflags=-O1
-      - LD=clang-8
-      - LDFLAGS='-fsanitize=memory -fPIC'
-      - CONFIG_FLAG='--with-out-ext=openssl --without-gmp --without-jemalloc --without-valgrind'
-
-  - &UBSAN
-    name: -fsanitize=undefined
-    <<: *clang-8
-    #<<: *cron-only
-    <<: *make-test-only
-    env:
-      - GEMS_FOR_TEST=
-      - cflags='-U_FORTIFY_SOURCE -fsanitize=undefined,integer,nullability -fno-sanitize=implicit-integer-sign-change,unsigned-integer-overflow'
-      - cppflags=-DUNALIGNED_WORD_ACCESS=0
-      - debugflags=-ggdb3
-      - optflags='-O1 -march=native'
-      - LD=clang-8
-      - LDFLAGS='-fsanitize=undefined,integer,nullability -fno-sanitize=implicit-integer-sign-change,unsigned-integer-overflow'
-
-  - &i686-linux
-    name: i686-linux
-    compiler: gcc-8
-    env:
-      - GCC_FLAGS=-m32
-      - debugflags=-g0
-      - SETARCH='setarch i686 --verbose --3gb'
-    # # Not using addon to control retries
-    # addons:
-    #   apt:
-    #     sources:
-    #       - ubuntu-toolchain-r-test
-    before_install:
-      - tool/travis_retry.sh sudo -E apt-add-repository -y "ppa:ubuntu-toolchain-r/test"
-      - tool/travis_retry.sh sudo bash -c "rm -rf '${TRAVIS_ROOT}/var/lib/apt/lists/'* && exec apt-get update -yq"
-      - |-
-        tool/travis_retry.sh sudo -E apt-get $travis_apt_get_options install \
-          gcc-8-multilib \
-          libffi-dev:i386 \
-          libffi6:i386 \
-          libgdbm-dev:i386 \
-          libgdbm3:i386 \
-          libncurses5-dev:i386 \
-          libncurses5:i386 \
-          libncursesw5-dev:i386 \
-          libreadline6-dev:i386 \
-          libreadline6:i386 \
-          libssl-dev:i386 \
-          libssl1.0.0:i386 \
-          linux-libc-dev:i386 \
-          zlib1g-dev:i386 \
-          zlib1g:i386
-
-  - &pedanticism
-    name: -std=c99 -pedantic
-    compiler: clang
-    <<: *make-test-only
-    env:
-      - GEMS_FOR_TEST=
-      - GCC_FLAGS='-std=c99 -Werror=pedantic -pedantic-errors'
-      - CONFIG_FLAG=
-      - JOBS=
-      - >-
-        warnflags='
-        -Wall
-        -Wextra
-        -Werror=deprecated-declarations
-        -Werror=division-by-zero
-        -Werror=extra-tokens
-        -Werror=implicit-function-declaration
-        -Werror=implicit-int
-        -Werror=pointer-arith
-        -Werror=shorten-64-to-32
-        -Werror=write-strings
-        -Wmissing-noreturn
-        -Wno-constant-logical-operand
-        -Wno-missing-field-initializers
-        -Wno-overlength-strings
-        -Wno-parentheses-equality
-        -Wno-self-assign
-        -Wno-tautological-compare
-        -Wno-unused-local-typedef
-        -Wno-unused-parameter
-        -Wunused-variable'
-      - LDFLAGS=-Wno-unused-command-line-argument
-
-  - &rubyspec
-    name: Check ruby/spec version guards on Ruby 2.4
-    language: ruby
-    rvm: 2.4.6
-    before_install:
-    install:
-    before_script: chmod -R u+w spec/ruby
-    # -j randomly hangs.
-    script: ruby -C spec/ruby ../mspec/bin/mspec .
-    after_failure:
-      - echo "ruby/spec failed on Ruby 2.4. This is likely because of a missing ruby_version_is guard, please add it. See spec/README.md."
-
-  - &baseruby
-    name: "BASERUBY: Ruby 1.9.3"
-    <<: *gcc-8
-    <<: *make-test-only
-    dist: trusty # xenial no longer has ruby-1.9.3
-    language: ruby
-    rvm: 1.9.3
-    # For some reason, enabling apt addon seems to be required to pass `apt-get update` on trusty.
-    addons:
-      apt:
-        sources: []
-
-  - &dependency
-    name: Check dependencies in makefiles
-    language: ruby
-    before_install:
-    install:
-    before_script:
-      - |-
-        ruby -e 'new = []
-          Dir.glob("ext/**/extconf.rb") {|ex|
-            unless File.exist?(dep = File.dirname(ex)+"/depend")
-              puts "Adding "+dep
-              File.copy_stream("template/depend.tmpl", dep)
-              new << dep
-            end
-          }
-          exec("git", "add", *new) unless new.empty?'
-      - git diff --cached
-      - "> config.status"
-      - "> .rbconfig.time"
-      - sed -f tool/prereq.status template/Makefile.in common.mk > Makefile
-      - make touch-unicode-files
-      - make -s $JOBS $UPDATE_UNICODE up
-      - make -s $JOBS srcs
-      - rm -f config.status Makefile rbconfig.rb .rbconfig.time
-      - $SETARCH ./configure -C --disable-install-doc --prefix=$RUBY_PREFIX --disable-rubygems 'optflags=-O0' 'debugflags=-save-temps=obj -g'
-      - ruby tool/update-deps --fix
-    script:
-      - git diff --no-ext-diff --ignore-submodules --exit-code
-    after_failure:
-      - echo "Dependencies need to update"
-    env:
-      - CONFIG_FLAG=
-
-matrix:
-  include:
-    # Build every commit:
-    - <<: *x86_64-linux
-    - <<: *i686-linux
-    - <<: *pedanticism
-    - <<: *assertions
-    - <<: *baseruby
-    - <<: *rubyspec
-    - <<: *dependency
-    # Build every commit (Allowed Failures):
-    - <<: *ASAN
-    - <<: *MSAN
-    - <<: *UBSAN
-    # Cron only:
-    - <<: *jemalloc
-    - <<: *VM_CHECK_MODE
-    - <<: *SUPPORT_JOKE
-    - <<: *WITH_COROUTINE_UCONTEXT
-    - <<: *WITH_COROUTINE_COPY
-    - <<: *TOKEN_THREADED_CODE
-    - <<: *CALL_THREADED_CODE
-    - <<: *NO_THREADED_CODE
-  allow_failures:
-    - name: -fsanitize=address
-    - name: -fsanitize=memory
-    - name: -fsanitize=undefined
-  fast_finish: true
-
-before_script:
-  - date # Debugging "Permission defined" failure on darwin like https://travis-ci.org/ruby/ruby/jobs/508683759
-  - echo JOBS=${JOBS} SETARCH=${SETARCH}
-  - $SETARCH uname -a
-  - $SETARCH uname -r
-  - rm -fr .ext autom4te.cache
-  - echo $TERM
-  - |-
-    [ -d ~/.downloaded-cache ] ||
-    mkdir ~/.downloaded-cache
-  - ln -s ~/.downloaded-cache
-  - "> config.status"
-  - "> .rbconfig.time"
-  - sed -f tool/prereq.status template/Makefile.in common.mk > Makefile
-  - date; make touch-unicode-files
-  - date; make -s $JOBS $UPDATE_UNICODE up
-  - date; make -s $JOBS srcs
-  - rm -f config.status Makefile rbconfig.rb .rbconfig.time
-  - |-
-    if [ -d ~/config_2nd ]; then
-      cp -pr ~/config_2nd build
-    else
-      mkdir build
-    fi
-  - mkdir config_1st config_2nd
-  - chmod -R a-w .
-  - chmod -R u+w build config_1st config_2nd
-  - cd build
-  - ccache --show-stats
-  - |-
-    case "$CC" in
-    gcc*)   CC="ccache $CC${GCC_FLAGS:+ }$GCC_FLAGS -fno-diagnostics-color";;
-    clang*) CC="ccache $CC${GCC_FLAGS:+ }$GCC_FLAGS -fno-color-diagnostics";;
-    esac
-  - |-
-    [ ! -f config.cache ] ||
-    [ "$CC" = "`sed -n s/^ac_cv_prog_CC=//p config.cache`" ] ||
-    (set -x; exec rm config.cache)
-  - $SETARCH ../configure -C --disable-install-doc --prefix=$RUBY_PREFIX $CONFIG_FLAG
-  - cp -pr config.cache config.status .ext/include ../config_1st
-  - $SETARCH make reconfig
-  - cp -pr config.cache config.status .ext/include ../config_2nd
-  - (cd .. && exec diff -ru config_1st config_2nd)
-  - chmod u+w ..
-  - rm -rf ~/config_2nd
-  - mv ../config_2nd ~
-  - chmod u-w ..
-  - $SETARCH make -s $JOBS
-  - |-
-    date; : # Debugging "Permission defined" failure on darwin like https://travis-ci.org/ruby/ruby/jobs/508683759
-    if ! make install; then
-      if [ "$(uname)" = Darwin ]; then
-        # Debugging "Permission defined" failure on darwin like https://travis-ci.org/ruby/ruby/jobs/508683759
-        set -x
-        date
-        ./miniruby -e 'ARGV.map{|path|[path,File.stat(path)]}.sort_by{|path,st|st.mtime}.each{|path,st|p mtime:st.mtime.to_f, ctime:st.ctime.to_f, path:path}' .ext/.timestamp/.RUBYCOMMONDIR*time .ext/common/bigdecimal/*.rb ../ext/bigdecimal/lib/bigdecimal/*.rb . .. .ext .ext/common .ext/common/bigdecimal ext/bigdecimal ../ext ../ext/bigdecimal ../ext/bigdecimal/lib ../ext/bigdecimal/lib/bigdecimal
-        make COPY='cp -f' install
-      else
-        exit 1
-      fi
-    fi
-  - ccache --show-stats
-  - |-
-    [ -z "${GEMS_FOR_TEST}" ] ||
-    $RUBY_PREFIX/bin/gem install --no-document $GEMS_FOR_TEST
-  - echo "raise 'do not load ~/.irbrc in test'" > ~/.irbrc
-
-script:
-  - $SETARCH make -s test -o showflags TESTOPTS="${TESTOPTS=$JOBS -q --tty=no}"
-  - travis_wait 50 $SETARCH make -s test-all -o exts TESTOPTS="${TESTOPTS} ${TEST_ALL_OPTS}" RUBYOPT="-w"
-  - $SETARCH make -s test-spec MSPECOPT=-ff # not using `-j` because sometimes `mspec -j` silently dies
-  - $SETARCH make -s -o showflags leaked-globals
-
-# Branch matrix.  Not all branches are Travis-ready so we limit branches here.
-branches:
-  only:
-    - master
-    - ruby_2_4
-    - ruby_2_5
-    - ruby_2_6
-
-# We want to be notified when something happens.
-notifications:
-  irc:
-    channels:
-      - "chat.freenode.net#ruby-core"
-    on_success: change # [always|never|change] # default: always
-    on_failure: always # [always|never|change] # default: always
-    template:
-      - "%{message} by @%{author}: See %{build_url}"
-
-  slack:
-    rooms:
-      - secure: ah7UEHBvncXT7bM5mvYIQAO+tIyV/wl7nXLb7wQD16dO2v8Gragy0mWjB79Q09hrrMGmp6H9bCDpdGS80boIA5EHaHoG4QaP0i9bsSt8U2AMWgZtfyIgQKJ4H2kXkGlrjO+AXTgnIkP7LNjdgAVUUTGQPb26T3QmoN2Splt+fIQ= # ruby:<token>#alerts
-    on_pull_requests: false
-    on_success: change
-    on_failure: always
-
-  email:
-    - ko1c-failure@atdot.net
diff --git a/BSDL b/BSDL
index a009caefea..66d93598aa 100644
--- a/BSDL
+++ b/BSDL
@@ -4,10 +4,10 @@ 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.
+   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.
+   notice, this list of conditions and the following disclaimer in the
+   documentation and/or other materials provided with the distribution.
 
 THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index ffdf2dd4b8..13df6087ca 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -1,4 +1 @@
-Please see the [official issue tracker] and wiki [HowToContribute].
-
-[official issue tracker]: https://bugs.ruby-lang.org
-[HowToContribute]: https://bugs.ruby-lang.org/projects/ruby/wiki/HowToContribute
+See ["Contributing to Ruby"](https://docs.ruby-lang.org/en/master/contributing_md.html), which includes setup and build instructions.
diff --git a/LEGAL b/LEGAL
index 565c4c9cde..0423d57ac9 100644
--- a/LEGAL
+++ b/LEGAL
@@ -7,92 +7,118 @@ All the files in this distribution are covered under either the Ruby's
 license (see the file COPYING) or public-domain except some files
 mentioned below.
 
-ccan/build_assert/build_assert.h::
-ccan/check_type/check_type.h::
-ccan/container_of/container_of.h::
-ccan/str/str.h::
+[addr2line.c]
 
-  These files are licensed under the CC0.
+  A part of this file is from FreeBSD.
 
   >>>
-    https://creativecommons.org/choose/zero/
+    Copyright (c) 1986, 1988, 1991, 1993::
+    The Regents of the University of California.  All rights reserved.
 
-ccan/list/list.h::
+    (c) UNIX System Laboratories, Inc.
 
-  This file is licensed under the MIT License.
+    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.
 
-  >>>
-    Permission is hereby granted, free of charge, to any person obtaining a copy
-    of this software and associated documentation files (the "Software"), to deal
-    in the Software without restriction, including without limitation the rights
-    to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-    copies of the Software, and to permit persons to whom the Software is
-    furnished to do so, subject to the following conditions:
+    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.
 
-    The above copyright notice and this permission notice shall be included in
-    all copies or substantial portions of the Software.
+    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.
 
-    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
-    THE SOFTWARE.
-
-include/ruby/onigmo.h::
-include/ruby/oniguruma.h::
-regcomp.c::
-regenc.c::
-regenc.h::
-regerror.c::
-regexec.c::
-regint.h::
-regparse.c::
-regparse.h::
-enc/ascii.c::
-enc/big5.c::
-enc/cp949.c::
-enc/emacs_mule.c::
-enc/encdb.c::
-enc/euc_jp.c::
-enc/euc_kr.c::
-enc/euc_tw.c::
-enc/gb18030.c::
-enc/gb2312.c::
-enc/gbk.c::
-enc/iso_8859_1.c::
-enc/iso_8859_10.c::
-enc/iso_8859_11.c::
-enc/iso_8859_13.c::
-enc/iso_8859_14.c::
-enc/iso_8859_15.c::
-enc/iso_8859_16.c::
-enc/iso_8859_2.c::
-enc/iso_8859_3.c::
-enc/iso_8859_4.c::
-enc/iso_8859_5.c::
-enc/iso_8859_6.c::
-enc/iso_8859_7.c::
-enc/iso_8859_8.c::
-enc/iso_8859_9.c::
-enc/koi8_r.c::
-enc/koi8_u.c::
-enc/shift_jis.c::
-enc/unicode.c::
-enc/us_ascii.c::
-enc/utf_16be.c::
-enc/utf_16le.c::
-enc/utf_32be.c::
-enc/utf_32le.c::
-enc/utf_8.c::
-enc/windows_1251.c::
+	@(#)subr_prf.c	8.3 (Berkeley) 1/21/94
+
+
+[ccan/build_assert/build_assert.h]
+[ccan/check_type/check_type.h]
+[ccan/container_of/container_of.h]
+[ccan/str/str.h]
+
+  These files are licensed under the {CC0}[https://creativecommons.org/choose/zero/].
+
+[ccan/list/list.h]
+
+  This file is licensed under the {MIT License}[rdoc-label:label-MIT+License].
+
+[coroutine]
+
+  Unless otherwise specified, these files are licensed under the
+  {MIT License}[rdoc-label:label-MIT+License].
+
+[include/ruby/onigmo.h]
+[include/ruby/oniguruma.h]
+[regcomp.c]
+[regenc.c]
+[regenc.h]
+[regerror.c]
+[regexec.c]
+[regint.h]
+[regparse.c]
+[regparse.h]
+[enc/ascii.c]
+[enc/big5.c]
+[enc/cp949.c]
+[enc/emacs_mule.c]
+[enc/encdb.c]
+[enc/euc_jp.c]
+[enc/euc_kr.c]
+[enc/euc_tw.c]
+[enc/gb18030.c]
+[enc/gb2312.c]
+[enc/gbk.c]
+[enc/iso_8859_1.c]
+[enc/iso_8859_10.c]
+[enc/iso_8859_11.c]
+[enc/iso_8859_13.c]
+[enc/iso_8859_14.c]
+[enc/iso_8859_15.c]
+[enc/iso_8859_16.c]
+[enc/iso_8859_2.c]
+[enc/iso_8859_3.c]
+[enc/iso_8859_4.c]
+[enc/iso_8859_5.c]
+[enc/iso_8859_6.c]
+[enc/iso_8859_7.c]
+[enc/iso_8859_8.c]
+[enc/iso_8859_9.c]
+[enc/koi8_r.c]
+[enc/koi8_u.c]
+[enc/shift_jis.c]
+[enc/unicode.c]
+[enc/us_ascii.c]
+[enc/utf_16be.c]
+[enc/utf_16le.c]
+[enc/utf_32be.c]
+[enc/utf_32le.c]
+[enc/utf_8.c]
+[enc/windows_1251.c]
+[enc/windows_31j.c]
 
   Onigmo (Oniguruma-mod) LICENSE
 
   >>>
-    Copyright (c) 2002-2009  K.Kosako  <sndgk393 AT ybb DOT ne DOT jp>  
-    Copyright (c) 2011-2014  K.Takata  <kentkt AT csc DOT jp>  
+    Copyright (c) 2002-2009::  K.Kosako  <sndgk393 AT ybb DOT ne DOT jp>
+    Copyright (c) 2011-2014::  K.Takata  <kentkt AT csc DOT jp>
     All rights reserved.
 
     Redistribution and use in source and binary forms, with or without
@@ -119,7 +145,7 @@ enc/windows_1251.c::
   Oniguruma LICENSE
 
   >>>
-    Copyright (c) 2002-2009  K.Kosako  <sndgk393 AT ybb DOT ne DOT jp>  
+    Copyright (c) 2002-2009::  K.Kosako  <sndgk393 AT ybb DOT ne DOT jp>
     All rights reserved.
 
     Redistribution and use in source and binary forms, with or without
@@ -150,10 +176,69 @@ enc/windows_1251.c::
     When this software is partly used or it is distributed with Ruby,
     this of Ruby follows the license of Ruby.
 
-enc/trans/GB/GB12345%UCS.src::
-enc/trans/GB/UCS%GB12345.src::
-enc/trans/GB/GB2312%UCS.src::
-enc/trans/GB/UCS%GB2312.src::
+[enc/windows_1250.c]
+[enc/windows_1252.c]
+
+  >>>
+    Copyright (c) 2006-2007::  Byte      <byte AT mail DOT kna DOT ru>
+                               K.Kosako  <sndgk393 AT ybb DOT ne DOT jp>
+    All rights reserved.
+
+    Redistribution and use in source and binary forms, with or without
+    modification, are permitted provided that the following conditions
+    are met:
+    1. Redistributions of source code must retain the above copyright
+       notice, this list of conditions and the following disclaimer.
+    2. Redistributions in binary form must reproduce the above copyright
+       notice, this list of conditions and the following disclaimer in the
+       documentation and/or other materials provided with the distribution.
+
+    THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+    ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+    IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+    ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+    FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+    DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+    OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+    HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+    LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+    OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+    SUCH DAMAGE.
+
+[enc/cesu_8.c]
+[enc/windows_1253.c]
+[enc/windows_1254.c]
+[enc/windows_1257.c]
+
+  >>>
+    Copyright (c) 2002-2007::  K.Kosako  <sndgk393 AT ybb DOT ne DOT jp>
+    All rights reserved.
+
+    Redistribution and use in source and binary forms, with or without
+    modification, are permitted provided that the following conditions
+    are met:
+    1. Redistributions of source code must retain the above copyright
+       notice, this list of conditions and the following disclaimer.
+    2. Redistributions in binary form must reproduce the above copyright
+       notice, this list of conditions and the following disclaimer in the
+       documentation and/or other materials provided with the distribution.
+
+    THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+    ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+    IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+    ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+    FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+    DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+    OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+    HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+    LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+    OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+    SUCH DAMAGE.
+
+[enc/trans/GB/GB12345%UCS.src]
+[enc/trans/GB/UCS%GB12345.src]
+[enc/trans/GB/GB2312%UCS.src]
+[enc/trans/GB/UCS%GB2312.src]
 
   These files have this explanatory texts.
 
@@ -165,12 +250,12 @@ enc/trans/GB/UCS%GB2312.src::
     files for any particular purpose, and has ceased to publish the files many
     years ago.
 
-enc/trans/JIS/JISX0201-KANA%UCS.src::
-enc/trans/JIS/JISX0208\@1990%UCS.src::
-enc/trans/JIS/JISX0212%UCS.src::
-enc/trans/JIS/UCS%JISX0201-KANA.src::
-enc/trans/JIS/UCS%JISX0208@1990.src::
-enc/trans/JIS/UCS%JISX0212.src::
+[enc/trans/JIS/JISX0201-KANA%UCS.src]
+[enc/trans/JIS/JISX0208\@1990%UCS.src]
+[enc/trans/JIS/JISX0212%UCS.src]
+[enc/trans/JIS/UCS%JISX0201-KANA.src]
+[enc/trans/JIS/UCS%JISX0208@1990.src]
+[enc/trans/JIS/UCS%JISX0212.src]
 
   These files are copyrighted as the following.
 
@@ -179,49 +264,64 @@ enc/trans/JIS/UCS%JISX0212.src::
 
     For terms of use, see http://www.unicode.org/terms_of_use.html
 
-enc/trans/JIS/JISX0213-1%UCS@BMP.src::
-enc/trans/JIS/JISX0213-1%UCS@SIP.src::
-enc/trans/JIS/JISX0213-2%UCS@BMP.src::
-enc/trans/JIS/JISX0213-2%UCS@SIP.src::
+[enc/trans/JIS/JISX0213-1%UCS@BMP.src]
+[enc/trans/JIS/JISX0213-1%UCS@SIP.src]
+[enc/trans/JIS/JISX0213-2%UCS@BMP.src]
+[enc/trans/JIS/JISX0213-2%UCS@SIP.src]
 
   These files are copyrighted as the following.
 
   >>>
-    Copyright (C) 2001 earthian@tama.or.jp, All Rights Reserved.  
-    Copyright (C) 2001 I'O, All Rights Reserved.  
-    Copyright (C) 2006 Project X0213, All Rights Reserved.  
+    Copyright (C) 2001:: earthian@tama.or.jp, All Rights Reserved.
+    Copyright (C) 2001:: I'O, All Rights Reserved.
+    Copyright (C) 2006:: Project X0213, All Rights Reserved.
     You can use, modify, distribute this table freely.
 
-enc/trans/JIS/UCS@BMP%JISX0213-1.src::
-enc/trans/JIS/UCS@BMP%JISX0213-2.src::
-enc/trans/JIS/UCS@SIP%JISX0213-1.src::
-enc/trans/JIS/UCS@SIP%JISX0213-2.src::
+[enc/trans/JIS/UCS@BMP%JISX0213-1.src]
+[enc/trans/JIS/UCS@BMP%JISX0213-2.src]
+[enc/trans/JIS/UCS@SIP%JISX0213-1.src]
+[enc/trans/JIS/UCS@SIP%JISX0213-2.src]
 
   These files are copyrighted as the following.
 
   >>>
-    Copyright (C) 2001 earthian@tama.or.jp, All Rights Reserved.  
-    Copyright (C) 2001 I'O, All Rights Reserved.  
+    Copyright (C) 2001:: earthian@tama.or.jp, All Rights Reserved.
+    Copyright (C) 2001:: I'O, All Rights Reserved.
     You can use, modify, distribute this table freely.
 
-configure::
+[enc/trans/ucm/glibc-BIG5-2.3.3.ucm]
+[enc/trans/ucm/glibc-BIG5HKSCS-2.3.3.ucm]
+
+  >>>
+    Copyright (C) 2001-2005:: International Business Machines
+                              Corporation and others.  All Rights Reserved.
+
+[enc/trans/ucm/windows-950-2000.ucm]
+[enc/trans/ucm/windows-950_hkscs-2001.ucm]
+
+  >>>
+    Copyright (C) 2001-2002:: International Business Machines
+                              Corporation and others.  All Rights Reserved.
+
+
+[configure]
 
   This file is free software.
 
   >>>
-    Copyright (C) 1992-1996, 1998-2012 Free Software Foundation, Inc.
+    Copyright (C) 1992-1996, 1998-2012:: Free Software Foundation, Inc.
 
     This configure script is free software; the Free Software Foundation
     gives unlimited permission to copy, distribute and modify it.
 
-tool/config.guess::
-tool/config.sub::
+[tool/config.guess]
+[tool/config.sub]
 
   As long as you distribute these files with the file configure, they
   are covered under the Ruby's license.
 
   >>>
-    Copyright 1992-2018 Free Software Foundation, Inc.
+    Copyright 1992-2018:: Free Software Foundation, Inc.
 
     This file is free software; you can redistribute it and/or modify it
     under the terms of the GNU General Public License as published by
@@ -243,14 +343,43 @@ tool/config.sub::
     program.  This Exception is an additional permission under section 7
     of the GNU General Public License, version 3 ("GPLv3").
 
-parse.c::
+[tool/lib/test/*]
+[tool/lib/core_assertions.rb]
+
+  Some of methods on these files are based on MiniTest 4. MiniTest 4 is
+  distributed under the MIT License.
+
+  >>>
+    Copyright (c) Ryan Davis, seattle.rb
+
+    Permission is hereby granted, free of charge, to any person obtaining
+    a copy of this software and associated documentation files (the
+    'Software'), to deal in the Software without restriction, including
+    without limitation the rights to use, copy, modify, merge, publish,
+    distribute, sublicense, and/or sell copies of the Software, and to
+    permit persons to whom the Software is furnished to do so, subject to
+    the following conditions:
+
+    The above copyright notice and this permission notice shall be
+    included in all copies or substantial portions of the Software.
+
+    THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND,
+    EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+    MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+    IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+    CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+    TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+    SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 
-  This file is licensed under the GPL, but is incorporated into Ruby and
+[parse.c]
+[parse.h]
+
+  These files are licensed under the GPL, but are incorporated into Ruby and
   redistributed under the terms of the Ruby license, as permitted by the
   exception to the GPL below.
 
   >>>
-    Copyright (C) 1984, 1989-1990, 2000-2015, 2018 Free Software Foundation, Inc.
+    Copyright (C) 1984, 1989-1990, 2000-2015, 2018:: Free Software Foundation, Inc.
 
     This program is free software: you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
@@ -278,12 +407,12 @@ parse.c::
     This special exception was added by the Free Software Foundation in
     version 2.2 of Bison.
 
-missing/dtoa.c::
+[missing/dtoa.c]
 
   This file is under these licenses.
 
   >>>
-    Copyright (c) 1991, 2000, 2001 by Lucent Technologies.
+    Copyright (c) 1991, 2000, 2001:: by Lucent Technologies.
 
     Permission to use, copy, modify, and distribute this software for any
     purpose without fee is hereby granted, provided that this entire notice
@@ -297,8 +426,8 @@ missing/dtoa.c::
     OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR PURPOSE.
 
   >>>
-    Copyright (c) 2004-2008 David Schultz <das@FreeBSD.ORG>  
-    All rights reserved.
+    Copyright (c) 2004-2008:: David Schultz <das@FreeBSD.ORG>
+                              All rights reserved.
 
     Redistribution and use in source and binary forms, with or without
     modification, are permitted provided that the following conditions
@@ -321,32 +450,34 @@ missing/dtoa.c::
     OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     SUCH DAMAGE.
 
-win32/win32.{c,h}::
+[win32/win32.c]
+[include/ruby/win32.h]
 
   You can apply the Artistic License to these files. (or GPL,
   alternatively)
 
   >>>
-    Copyright (c) 1993, Intergraph Corporation
+    Copyright (c) 1993:: Intergraph Corporation
 
     You may distribute under the terms of either the GNU General Public
     License or the Artistic License, as specified in the perl README file.
 
-missing/mt19937.c::
+[missing/mt19937.c]
 
   This file is under the new-style BSD license.
 
   >>>
-    A C-program for MT19937, with initialization improved 2002/2/10.
-    Coded by Takuji Nishimura and Makoto Matsumoto.  
+    A C-program for MT19937, with initialization improved 2002/2/10.::
+    Coded by Takuji Nishimura and Makoto Matsumoto.
+
     This is a faster version by taking Shawn Cokus's optimization,
     Matthe Bellew's simplification, Isaku Wada's real version.
 
     Before using, initialize the state by using init_genrand(seed)
     or init_by_array(init_key, key_length).
 
-    Copyright (C) 1997 - 2002, Makoto Matsumoto and Takuji Nishimura,
-    All rights reserved.
+    Copyright (C) 1997 - 2002:: Makoto Matsumoto and Takuji Nishimura,
+                                All rights reserved.
 
     Redistribution and use in source and binary forms, with or without
     modification, are permitted provided that the following conditions
@@ -382,13 +513,13 @@ missing/mt19937.c::
 
   The Wayback Machine url: http://web.archive.org/web/19990429082237/http://www.math.keio.ac.jp/matumoto/emt.html
 
-missing/procstat_vm.c::
+[missing/procstat_vm.c]
 
   This file is under the new-style BSD license.
 
   >>>
-    Copyright (c) 2007 Robert N. M. Watson  
-    All rights reserved.
+    Copyright (c) 2007:: Robert N. M. Watson
+                         All rights reserved.
 
     Redistribution and use in source and binary forms, with or without
     modification, are permitted provided that the following conditions
@@ -413,151 +544,65 @@ missing/procstat_vm.c::
 
     $FreeBSD: head/usr.bin/procstat/procstat_vm.c 261780 2014-02-11 21:57:37Z jhb $
 
-vsnprintf.c::
+[vsnprintf.c]
 
-  This file is under the old-style BSD license.  Note that the
-  paragraph 3 below is now null and void.
+  This file is under the {old-style BSD license}[rdoc-label:label-Old-style+BSD+license].
 
   >>>
-    Copyright (c) 1990, 1993  
+    Copyright (c) 1990, 1993::
     The Regents of the University of California.  All rights reserved.
 
     This code is derived from software contributed to Berkeley by
     Chris Torek.
 
-    Redistribution and use in source and binary forms, with or without
-    modification, are permitted provided that the following conditions
-    are met:
-    1. Redistributions of source code must retain the above copyright
-       notice, this list of conditions and the following disclaimer.
-    2. Redistributions in binary form must reproduce the above copyright
-       notice, this list of conditions and the following disclaimer in the
-       documentation and/or other materials provided with the distribution.
-    3. Neither the name of the University nor the names of its contributors
-       may be used to endorse or promote products derived from this software
-       without specific prior written permission.
-
-    THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
-    ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
-    IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
-    ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
-    FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
-    DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
-    OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
-    HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
-    LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
-    OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
-    SUCH DAMAGE.
-
-    IMPORTANT NOTE:
-    --------------
-    From ftp://ftp.cs.berkeley.edu/pub/4bsd/README.Impt.License.Change
-    paragraph 3 above is now null and void.
-
-st.c::
-strftime.c::
-include/ruby/st.h::
-missing/acosh.c::
-missing/alloca.c::
-missing/dup2.c::
-missing/erf.c::
-missing/finite.c::
-missing/hypot.c::
-missing/isinf.c::
-missing/isnan.c::
-missing/lgamma_r.c::
-missing/memcmp.c::
-missing/memmove.c::
-missing/strchr.c::
-missing/strerror.c::
-missing/strstr.c::
-missing/tgamma.c::
-ext/date/date_strftime.c::
-ext/digest/sha1/sha1.c::
-ext/digest/sha1/sha1.h::
-ext/sdbm/_sdbm.c::
-ext/sdbm/sdbm.h::
+[st.c]
+[strftime.c]
+[include/ruby/st.h]
+[missing/acosh.c]
+[missing/alloca.c]
+[missing/erf.c]
+[missing/hypot.c]
+[missing/lgamma_r.c]
+[missing/memcmp.c]
+[missing/memmove.c]
+[missing/strchr.c]
+[missing/strerror.c]
+[missing/strstr.c]
+[missing/tgamma.c]
+[ext/date/date_strftime.c]
+[ext/digest/sha1/sha1.c]
+[ext/digest/sha1/sha1.h]
 
   These files are all under public domain.
 
-missing/crypt.c::
+[missing/crypt.c]
 
-  This file is under the old-style BSD license.  Note that the
-  paragraph 3 below is now null and void.
+  This file is under the {old-style BSD license}[rdoc-label:label-Old-style+BSD+license].
 
   >>>
-    Copyright (c) 1989, 1993  
+    Copyright (c) 1989, 1993::
     The Regents of the University of California.  All rights reserved.
 
     This code is derived from software contributed to Berkeley by
     Tom Truscott.
 
-    Redistribution and use in source and binary forms, with or without
-    modification, are permitted provided that the following conditions
-    are met:
-    1. Redistributions of source code must retain the above copyright
-       notice, this list of conditions and the following disclaimer.
-    2. Redistributions in binary form must reproduce the above copyright
-       notice, this list of conditions and the following disclaimer in the
-       documentation and/or other materials provided with the distribution.
-    3. Neither the name of the University nor the names of its contributors
-       may be used to endorse or promote products derived from this software
-       without specific prior written permission.
-
-    THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
-    ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
-    IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
-    ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
-    FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
-    DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
-    OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
-    HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
-    LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
-    OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
-    SUCH DAMAGE.
-
-missing/setproctitle.c::
+[missing/setproctitle.c]
 
-  This file is under the old-style BSD license.  Note that the
-  paragraph 3 below is now null and void.
+  This file is under the {old-style BSD license}[rdoc-label:label-Old-style+BSD+license].
 
   >>>
-    Copyright 2003 Damien Miller  
-    Copyright (c) 1983, 1995-1997 Eric P. Allman  
-    Copyright (c) 1988, 1993  
+    Copyright 2003:: Damien Miller
+    Copyright (c) 1983, 1995-1997:: Eric P. Allman
+    Copyright (c) 1988, 1993::
     The Regents of the University of California.  All rights reserved.
 
-    Redistribution and use in source and binary forms, with or without
-    modification, are permitted provided that the following conditions
-    are met:
-    1. Redistributions of source code must retain the above copyright
-       notice, this list of conditions and the following disclaimer.
-    2. Redistributions in binary form must reproduce the above copyright
-       notice, this list of conditions and the following disclaimer in the
-       documentation and/or other materials provided with the distribution.
-    3. Neither the name of the University nor the names of its contributors
-       may be used to endorse or promote products derived from this software
-       without specific prior written permission.
-
-    THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
-    ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
-    IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
-    ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
-    FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
-    DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
-    OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
-    HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
-    LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
-    OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
-    SUCH DAMAGE.
-
-missing/strlcat.c::
-missing/strlcpy.c::
+[missing/strlcat.c]
+[missing/strlcpy.c]
 
   These files are under an ISC-style license.
 
   >>>
-    Copyright (c) 1998, 2015 Todd C. Miller <Todd.Miller@courtesan.com>
+    Copyright (c) 1998, 2015:: Todd C. Miller <Todd.Miller@courtesan.com>
 
     Permission to use, copy, modify, and distribute this software for any
     purpose with or without fee is hereby granted, provided that the above
@@ -571,26 +616,26 @@ missing/strlcpy.c::
     ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
     OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 
-missing/langinfo.c::
+[missing/langinfo.c]
 
   This file is from http://www.cl.cam.ac.uk/~mgk25/ucs/langinfo.c.
   Ruby uses a modified version. The file contains the following
   author/copyright notice:
 
   >>>
-    Markus.Kuhn@cl.cam.ac.uk -- 2002-03-11  
+    Markus.Kuhn@cl.cam.ac.uk -- 2002-03-11::
     Permission to use, copy, modify, and distribute this software
     for any purpose and without fee is hereby granted. The author
     disclaims all warranties with regard to this software.
 
-ext/digest/md5/md5.c::
-ext/digest/md5/md5.h::
+[ext/digest/md5/md5.c]
+[ext/digest/md5/md5.h]
 
   These files are under the following license.  Ruby uses modified
   versions of them.
 
   >>>
-    Copyright (C) 1999, 2000 Aladdin Enterprises.  All rights reserved.
+    Copyright (C) 1999, 2000:: Aladdin Enterprises.  All rights reserved.
 
     This software is provided 'as-is', without any express or implied
     warranty.  In no event will the authors be held liable for any damages
@@ -611,8 +656,8 @@ ext/digest/md5/md5.h::
     L. Peter Deutsch
     ghost@aladdin.com
 
-ext/digest/rmd160/rmd160.c::
-ext/digest/rmd160/rmd160.h::
+[ext/digest/rmd160/rmd160.c]
+[ext/digest/rmd160/rmd160.h]
 
   These files have the following copyright information, and by the
   author we are allowed to use it under the new-style BSD license.
@@ -622,16 +667,16 @@ ext/digest/rmd160/rmd160.h::
               (Arranged for libc by Todd C. Miller)
     DATE::    1 March 1996
 
-    Copyright (c) Katholieke Universiteit Leuven
+    Copyright (c):: Katholieke Universiteit Leuven
     1996, All Rights Reserved
 
-ext/digest/sha2/sha2.c::
-ext/digest/sha2/sha2.h::
+[ext/digest/sha2/sha2.c]
+[ext/digest/sha2/sha2.h]
 
   These files are under the new-style BSD license.
 
   >>>
-    Copyright 2000 Aaron D. Gifford.  All rights reserved.
+    Copyright 2000:: Aaron D. Gifford.  All rights reserved.
 
     Redistribution and use in source and binary forms, with or without
     modification, are permitted provided that the following conditions
@@ -657,12 +702,12 @@ ext/digest/sha2/sha2.h::
     OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     SUCH DAMAGE.
 
-ext/json/generator/generator.c::
+[ext/json/generator/generator.c]
 
   The file contains the following copyright notice.
 
   >>>
-    Copyright 2001-2004 Unicode, Inc.
+    Copyright 2001-2004:: Unicode, Inc.
 
     Disclaimer::
 
@@ -682,15 +727,15 @@ ext/json/generator/generator.c::
       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::
+[ext/nkf/nkf-utf8/config.h]
+[ext/nkf/nkf-utf8/nkf.c]
+[ext/nkf/nkf-utf8/utf8tbl.c]
 
   These files are under the following license.  So to speak, it is
   copyrighted semi-public-domain software.
 
   >>>
-    Copyright (C) 1987, Fujitsu LTD. (Itaru ICHIKAWA)
+    Copyright (C) 1987:: Fujitsu LTD. (Itaru ICHIKAWA)
 
     Everyone is permitted to do anything on this program
     including copying, modifying, improving,
@@ -700,14 +745,14 @@ ext/nkf/nkf-utf8/utf8tbl.c::
     You don't have to ask before copying, redistribution or publishing.
     THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE.
 
-ext/psych::
-test/psych::
+[ext/psych]
+[test/psych]
 
   The files under these directories are under the following license, except for
   ext/psych/yaml.
 
   >>>
-    Copyright 2009 Aaron Patterson, et al.
+    Copyright 2009:: Aaron Patterson, et al.
 
     Permission is hereby granted, free of charge, to any person obtaining a copy of
     this software and associated documentation files (the 'Software'), to deal in
@@ -727,12 +772,12 @@ test/psych::
     OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
     SOFTWARE.
 
-ext/psych/yaml::
+[ext/psych/yaml]
 
   The files under this directory are under the following license.
 
   >>>
-    Copyright (c) 2006 Kirill Simonov
+    Copyright (c) 2006:: Kirill Simonov
 
     Permission is hereby granted, free of charge, to any person obtaining a copy of
     this software and associated documentation files (the "Software"), to deal in
@@ -752,14 +797,28 @@ ext/psych/yaml::
     OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
     SOFTWARE.
 
-ext/socket/addrinfo.h::
-ext/socket/getaddrinfo.c::
-ext/socket/getnameinfo.c::
+[ext/pty/pty.c]
+
+  >>>
+    C) Copyright 1998:: by Akinori Ito.
+
+    This software may be redistributed freely for this purpose, in full
+    or in part, provided that this entire copyright notice is included
+    on any copies of this software and applications and derivations thereof.
+
+    This software is provided on an "as is" basis, without warranty of any
+    kind, either expressed or implied, as to any matter including, but not
+    limited to warranty of fitness of purpose, or merchantability, or
+    results obtained from use of this software.
+
+[ext/socket/addrinfo.h]
+[ext/socket/getaddrinfo.c]
+[ext/socket/getnameinfo.c]
 
   These files are under the new-style BSD license.
 
   >>>
-    Copyright (C) 1995, 1996, 1997, 1998, and 1999 WIDE Project.
+    Copyright (C) 1995, 1996, 1997, 1998, and 1999:: WIDE Project.
     All rights reserved.
 
     Redistribution and use in source and binary forms, with or without
@@ -786,16 +845,16 @@ ext/socket/getnameinfo.c::
     OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     SUCH DAMAGE.
 
-ext/win32ole/win32ole.c::
+[ext/win32ole/win32ole.c]
 
   You can apply the Artistic License to this file. (or GPL,
   alternatively)
 
   >>>
-    (c) 1995 Microsoft Corporation. All rights reserved.
+    (c) 1995:: Microsoft Corporation. All rights reserved.
     Developed by ActiveWare Internet Corp., http://www.ActiveWare.com
 
-    Other modifications Copyright (c) 1997, 1998 by Gurusamy Sarathy
+    Other modifications Copyright (c) 1997, 1998:: by Gurusamy Sarathy
     <gsar@umich.edu> and Jan Dubois <jan.dubois@ibm.net>
 
     You may distribute under the terms of either the GNU General Public
@@ -804,20 +863,17 @@ ext/win32ole/win32ole.c::
 
   The Wayback Machine url: http://web.archive.org/web/19970607104352/http://www.activeware.com:80/
 
-lib/rdoc/generator/template/darkfish/css/fonts.css::
+[lib/rdoc/generator/template/darkfish/css/fonts.css]
 
-  This file is licensed under the SIL Open Font License.
+  This file is licensed under the {SIL Open Font License}[http://scripts.sil.org/OFL].
 
-  >>>
-    http://scripts.sil.org/OFL
-
-spec/mspec::
-spec/ruby::
+[spec/mspec]
+[spec/ruby]
 
   The files under these directories are under the following license.
 
   >>>
-    Copyright (c) 2008 Engine Yard, Inc. All rights reserved.
+    Copyright (c) 2008:: Engine Yard, Inc. All rights reserved.
 
     Permission is hereby granted, free of charge, to any person
     obtaining a copy of this software and associated documentation
@@ -840,17 +896,17 @@ spec/ruby::
     FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
     OTHER DEALINGS IN THE SOFTWARE.
 
-lib/rubygems.rb::
-lib/rubygems::
-test/rubygems::
+[lib/rubygems.rb]
+[lib/rubygems]
+[test/rubygems]
 
   RubyGems is under the following license.
 
   >>>
     RubyGems is copyrighted free software by Chad Fowler, Rich Kilmer, Jim
     Weirich and others.  You can redistribute it and/or modify it under
-    either the terms of the MIT license (see the file MIT.txt), or the
-    conditions below:
+    either the terms of the {MIT license}[rdoc-label:label-MIT+License], or the conditions
+    below:
 
     1. You may make and give away verbatim copies of the source form of the
        software without restriction, provided that you duplicate all of the
@@ -901,20 +957,117 @@ test/rubygems::
        WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
        PURPOSE.
 
-lib/bundler::
-lib/bundler.rb::
-lib/bundler.gemspec::
-spec/bundler::
-man/bundle-*,gemfile.*::
+[lib/bundler]
+[lib/bundler.rb]
+[spec/bundler]
 
   Bundler is under the following license.
 
   >>>
-    Portions copyright (c) 2010 Andre Arko  
-    Portions copyright (c) 2009 Engine Yard  
+    Portions copyright (c) 2010:: Andre Arko
+    Portions copyright (c) 2009:: Engine Yard
+
+    {MIT License}[rdoc-label:label-MIT+License]
+
+[lib/bundler/vendor/thor]
+
+  Thor is under the following license.
+
+  >>>
+    Copyright (c) 2008 Yehuda Katz, Eric Hodel, et al.
+
+    {MIT License}[rdoc-label:label-MIT+License]
+
+[lib/rubygems/resolver/molinillo]
+
+  molinillo is under the following license.
+
+  >>>
+    Copyright (c) 2014 Samuel E. Giddins segiddins@segiddins.me
+
+    {MIT License}[rdoc-label:label-MIT+License]
+
+[lib/bundler/vendor/pub_grub]
+
+  pub_grub is under the following license.
+
+  >>>
+    Copyright (c) 2018 John Hawthorn
+
+    {MIT License}[rdoc-label:label-MIT+License]
+
+[lib/bundler/vendor/connection_pool]
+
+  connection_pool is under the following license.
+
+  >>>
+    Copyright (c) 2011 Mike Perham
+
+    {MIT License}[rdoc-label:label-MIT+License]
+
+[lib/bundler/vendor/net-http-persistent]
+
+  net-http-persistent is under the following license.
+
+  >>>
+    Copyright (c) Eric Hodel, Aaron Patterson
 
-    MIT License::
+    {MIT License}[rdoc-label:label-MIT+License]
 
+[lib/did_you_mean]
+[lib/did_you_mean.rb]
+[test/did_you_mean]
+
+  did_you_mean is under the following license.
+
+  >>>
+    Copyright (c) 2014-2016 Yuki Nishijima
+
+    {MIT License}[rdoc-label:label-MIT+License]
+
+[lib/error_highlight]
+[lib/error_highlight.rb]
+[test/error_highlight]
+
+  error_highlight is under the following license.
+
+  >>>
+    Copyright (c) 2021 Yusuke Endoh
+
+    {MIT License}[rdoc-label:label-MIT+License]
+
+[benchmark/so_ackermann.rb]
+[benchmark/so_array.rb]
+[benchmark/so_binary_trees.rb]
+[benchmark/so_concatenate.rb]
+[benchmark/so_count_words.yml]
+[benchmark/so_exception.rb]
+[benchmark/so_fannkuch.rb]
+[benchmark/so_fasta.rb]
+[benchmark/so_k_nucleotide.yml]
+[benchmark/so_lists.rb]
+[benchmark/so_mandelbrot.rb]
+[benchmark/so_matrix.rb]
+[benchmark/so_meteor_contest.rb]
+[benchmark/so_nbody.rb]
+[benchmark/so_nested_loop.rb]
+[benchmark/so_nsieve.rb]
+[benchmark/so_nsieve_bits.rb]
+[benchmark/so_object.rb]
+[benchmark/so_partial_sums.rb]
+[benchmark/so_pidigits.rb]
+[benchmark/so_random.rb]
+[benchmark/so_reverse_complement.yml]
+[benchmark/so_sieve.rb]
+[benchmark/so_spectralnorm.rb]
+
+  These files are very old copy of then-called "The Great Computer Language
+  Shootout".  LEGAL SITUATION OF THESE FILES ARE UNCLEAR because the original
+  site has been lost.  Upstream diverged to delete several benchmarks listed
+  above.
+
+== MIT License
+>>>
       Permission is hereby granted, free of charge, to any person obtaining
       a copy of this software and associated documentation files (the
       "Software"), to deal in the Software without restriction, including
@@ -933,3 +1086,34 @@ man/bundle-*,gemfile.*::
       LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
       OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
       WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+== Old-style BSD license
+>>>
+      Redistribution and use in source and binary forms, with or without
+      modification, are permitted provided that the following conditions
+      are met:
+      1. Redistributions of source code must retain the above copyright
+         notice, this list of conditions and the following disclaimer.
+      2. Redistributions in binary form must reproduce the above copyright
+         notice, this list of conditions and the following disclaimer in the
+         documentation and/or other materials provided with the distribution.
+      3. Neither the name of the University nor the names of its contributors
+         may be used to endorse or promote products derived from this software
+         without specific prior written permission.
+
+      THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+      ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+      IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+      ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+      FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+      DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+      OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+      HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+      LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+      OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+      SUCH DAMAGE.
+
+      IMPORTANT NOTE::
+
+      From ftp://ftp.cs.berkeley.edu/pub/4bsd/README.Impt.License.Change
+      paragraph 3 above is now null and void.
diff --git a/NEWS b/NEWS
deleted file mode 100644
index 710039417a..0000000000
--- a/NEWS
+++ /dev/null
@@ -1,365 +0,0 @@
-# -*- rdoc -*-
-
-= NEWS for Ruby 2.7.0
-
-This document is a list of user visible feature changes made between
-releases except for bug fixes.
-
-Note that each entry is kept so brief that no reason behind or reference
-information is supplied with.  For a full list of changes with all
-sufficient information, see the ChangeLog file or Redmine
-(e.g. <tt>https://bugs.ruby-lang.org/issues/$FEATURE_OR_BUG_NUMBER</tt>)
-
-== Changes since the 2.6.0 release
-
-=== Language changes
-
-* Pattern matching is introduced as an experimental feature. [Feature #14912]
-
-* Method reference operator, <code>.:</code> is introduced as an
-  experimental feature.  [Feature #12125] [Feature #13581]
-
-* Preparations for the redesign of keyword arguments towards
-  Ruby 3.  [Feature #14183]
-
-  * Automatic conversion from a Hash to keyword arguments is deprecated:
-    when a method call passes a Hash at the last argument, and when the
-    called method accepts keywords, it is warned.
-    Please add a double splat operator.
-
-     def foo(key: 42); end; foo({key: 42})   # warned
-     def foo(**kw);    end; foo({key: 42})   # warned
-     def foo(key: 42); end; foo(**{key: 42}) # OK
-     def foo(opt={});  end; foo( key: 42 )   # OK
-
-  * Non-symbol keys are allowed as a keyword argument.
-
-     def foo(**kw); p kw; end; foo("str" => 1) #=> {"str"=>1}
-
-* Automatic conversion of keyword arguments and positional ones is
-  warned.  [Feature #14183]
-
-* Proc.new and proc with no block in a method called with a block is warned
-  now.
-
-* lambda with no block in a method called with a block errs.
-
-* Non-Symbol keys in a keyword arguments hash were prohibited in 2.6.0,
-  but are now allowed again.  [Bug #15658]
-
-* Numbered parameter as the default block parameter is introduced as an
-  experimental feature.  [Feature #4475]
-
-* A beginless range is experimentally introduced.  It might not be as useful
-  as an endless range, but would be good for DSL purpose.  [Feature #14799]
-
-     ary[..3]  # identical to ary[0..3]
-     where(sales: ..100)
-
-* Setting <code>$;</code> to non-nil value is warned now.  Use of it in
-  String#split is warned too.
-
-* Setting <code>$,</code> to non-nil value is warned now.  Use of it in
-  Array#join is warned too.
-
-* Quoted here-document identifier must end within the same line.
-
-     <<"EOS
-     " # This has been warned since 2.4
-     EOS
-
-
-* The flip-flop syntax deprecation is reverted. [Feature #5400]
-
-=== Core classes updates (outstanding ones only)
-
-Complex::
-
-  New method::
-
-    * Added Complex#<=>. So 0 <=> 0i will not raise NoMethodError. [Bug #15857]
-
-Dir::
-
-  Modified method::
-
-    * Dir#glob and Dir#[] no longer allow NUL-separated glob pattern.
-      Use Array instead.  [Feature #14643]
-
-Encoding::
-
-  * Added new encoding CESU-8 [Feature #15931]
-
-Enumerable::
-
-  New methods::
-
-    * Added Enumerable#filter_map.  [Feature #15323]
-
-    * Added Enumerable#tally.  [Feature #11076]
-
-Enumerator::
-
-  New method::
-
-    * Added Enumerator::Yielder#to_proc so that a Yielder object
-      can be directly passed to another method as a block
-      argument.  [Feature #15618]
-
-FrozenError::
-
-  New method::
-
-    * Added FrozenError#receiver to return the frozen object that
-      modification was attempted on.  To set this object when raising
-      FrozenError in Ruby code, pass it as the second argument to
-      FrozenError.new.
-
-GC::
-
-  New method::
-
-    * Added GC.compact method for compacting the heap.
-      This function compacts live objects in the heap so that fewer pages may
-      be used, and the heap may be more CoW friendly. [Feature #15626]
-
-      Details on the algorithm and caveats can be found here:
-      https://bugs.ruby-lang.org/issues/15626
-
-IO::
-
-  New method::
-
-    * Added IO#set_encoding_by_bom to check the BOM and set the external
-      encoding.  [Bug #15210]
-
-Integer::
-
-  Modified method::
-
-    * Integer#[] now supports range operation.  [Feature #8842]
-
-         0b01001101[2, 4]  #=> 0b0011
-         0b01001100[2..5]  #=> 0b0011
-         0b01001100[2...6] #=> 0b0011
-             ^^^^
-
-Module::
-
-  New method::
-
-    * Added Module#const_source_location to retrieve the location where a
-      constant is defined.  [Feature #10771]
-
-  Modified method::
-
-    * Module#autoload? now takes an +inherit+ optional argument, like as
-      Module#const_defined?.  [Feature #15777]
-
-ObjectSpace::WeakMap::
-
-  Modified method::
-
-    * ObjectSpace::WeakMap#[]= now accepts special objects as either key or
-      values.  [Feature #16035]
-
-Regexp / String::
-
-    * Update Unicode version and Emoji version from 11.0.0 to
-      12.0.0.  [Feature #15321]
-
-    * Update Unicode version to 12.1.0, adding support for
-      U+32FF SQUARE ERA NAME REIWA.  [Feature #15195]
-
-RubyVM::
-
-  Removed method::
-
-    * RubyVM.resolve_feature_path moved to
-      $LOAD_PATH.resolve_feature_path.  [Feature #15903] [Feature #15230]
-
-Time::
-
-  New methods::
-
-    * Added Time#ceil method.  [Feature #15772]
-
-    * Added Time#floor method.  [Feature #15653]
-
-UnboundMethod::
-
-  New methods::
-
-    * Added UnboundMethod#bind_call method.  [Feature #15955]
-
-`umethod.bind_call(obj, ...)` is semantically equivalent to
-`umethod.bind(obj).call(...)`.  This idiom is used in some libraries to
-call a method that is overridden.  The added method does the same
-without allocation of intermediate Method object.
-
-    class Foo
-      def add_1(x)
-        x + 1
-      end
-    end
-    class Bar < Foo
-      def add_1(x) # override
-        x + 2
-      end
-    end
-
-    obj = Bar.new
-    p obj.add_1(1) #=> 3
-    p Foo.instance_method(:add_1).bind(obj).call(1) #=> 2
-    p Foo.instance_method(:add_1).bind_call(obj, 1) #=> 2
-
-
-$LOAD_PATH::
-
-  New method::
-
-    * Added $LOAD_PATH.resolve_feature_path.  [Feature #15903] [Feature #15230]
-
-=== Stdlib updates (outstanding ones only)
-
-Bundler::
-
-  * Upgrade to Bundler 2.1.0.pre.1
-    Bundled from https://github.com/bundler/bundler/commit/a53709556b95a914e874b22ed2116a46b0528852
-
-CGI::
-
-  * CGI.escapeHTML becomes 2~5x faster when there's at least one escaped character.
-
-CSV::
-
-  * Upgrade to 3.0.9.
-    See https://github.com/ruby/csv/blob/master/NEWS.md.
-
-Date::
-
-  * Date.jisx0301, Date#jisx0301, and Date.parse support the new Japanese
-    era.  [Feature #15742]
-
-Delegator::
-
-  * Object#DelegateClass accepts a block and module_evals it in the context
-    of the returned class, similar to Class.new and Struct.new.
-
-ERB::
-
-  * Prohibit marshaling ERB instance.
-
-IRB::
-
-  * Introduce syntax highlight inspired by pry.gem to Binding#irb source lines,
-    REPL input, and inspect output of some core-class objects.
-
-  * Introduce multiline mode by Reline.
-
-  * Show documents when completion.
-
-  * Enable auto indent and save/load history by default.
-
-Net::FTP::
-
-  * Add features and options.  [Feature #15964]
-
-Net::IMAP::
-
-  * Add Server Name Indication (SNI) support.  [Feature #15594]
-
-open-uri::
-
-  * Warn open-uri's "open" method at Kernel.
-    Use URI.open instead.  [Misc #15893]
-
-  * The default charset of text/* media type is UTF-8 instead of
-    ISO-8859-1.  [Bug #15933]
-
-Pathname::
-
-  * Delegates 3 arguments from Pathname.glob to Dir.glob to
-    accept base: keyword.
-
-Racc::
-
-  * Merge 1.4.15 from upstream repository and added cli of racc.
-
-Reline::
-
-  * New stdlib that is compatible with readline stdlib by pure Ruby and also
-    has a multiline mode.
-
-RSS::
-
-  * Upgrade to RSS 0.2.8.
-    See https://github.com/ruby/rss/blob/master/NEWS.md.
-
-RubyGems::
-
-  * Upgrade to RubyGems 3.1.0.pre1
-    Bundled from https://github.com/rubygems/rubygems/commit/97b264f0fa248c864b6ee9a23d3ff1cdd217dddb
-
-=== Compatibility issues (excluding feature bug fixes)
-
-=== Stdlib compatibility issues (excluding feature bug fixes)
-
-profile.rb, Profiler__::
-
-  * Removed from standard library. No one maintains it from Ruby 2.0.0.
-
-=== C API updates
-
-  * C API declarations with `ANYARGS` are changed not to use `ANYARGS`
-    https://github.com/ruby/ruby/pull/2404
-
-=== Implementation improvements
-
-Fiber::
-
-  * Allow selecting different coroutine implementation by using
-    `--with-coroutine=`, e.g.
-
-         ./confgure --with-coroutine=ucontext
-         ./confgure --with-coroutine=copy
-
-  * Replace previous stack cache with fiber pool cache. The fiber pool
-    allocates many stacks in a single memory region. Stack allocation
-    becomes O(log N) and fiber creation is amortized O(1). Around 10x
-    performance improvement was measured in micro-benchmarks.
-
-Thread::
-
-  * VM stack memory allocation is now combined with native thread stack,
-    improving thread allocation performance and reducing allocation related
-    failures. ~10x performance improvement was measured in micro-benchmarks.
-
-JIT::
-
-  * JIT-ed code is recompiled to less-optimized code when an optimization assumption is invalidated.
-
-  * Method inlining is performed when a method is considered as pure.
-    This optimization is still experimental and many methods are NOT considered as pure yet.
-
-  * Default value of +--jit-max-cache+ is changed from 1,000 to 100
-
-  * Default value of +--jit-min-calls+ is changed from 5 to 10,000
-
-=== Miscellaneous changes
-
-* Support for IA64 architecture has been removed. Hardware for testing was
-  difficult to find, native fiber code is difficult to implement, and it added
-  non-trivial complexity to the interpreter. [Feature #15894]
-
-* Require compilers to support C99 [Misc #15347]
-
-  * Details of our dialect: https://bugs.ruby-lang.org/projects/ruby-trunk/wiki/C99
-
-* Ruby's upstream repository is changed from Subversion to Git.
-
-  * https://git.ruby-lang.org/ruby.git
-
-  * RUBY_REVISION class is changed from Integer to String.
-
-  * RUBY_DESCRIPTION includes Git revision instead of Subversion's one.
diff --git a/NEWS.md b/NEWS.md
new file mode 100644
index 0000000000..f6c3c6fc97
--- /dev/null
+++ b/NEWS.md
@@ -0,0 +1,820 @@
+# NEWS for Ruby 3.2.0
+
+This document is a list of user-visible feature changes
+since the **3.1.0** release, except for bug fixes.
+
+Note that each entry is kept to a minimum, see links for details.
+
+## Language changes
+
+* Anonymous rest and keyword rest arguments can now be passed as
+  arguments, instead of just used in method parameters.
+  [[Feature #18351]]
+
+    ```ruby
+    def foo(*)
+      bar(*)
+    end
+    def baz(**)
+      quux(**)
+    end
+    ```
+
+* A proc that accepts a single positional argument and keywords will
+  no longer autosplat. [[Bug #18633]]
+
+    ```ruby
+    proc{|a, **k| a}.call([1, 2])
+    # Ruby 3.1 and before
+    # => 1
+    # Ruby 3.2 and after
+    # => [1, 2]
+    ```
+
+* Constant assignment evaluation order for constants set on explicit
+  objects has been made consistent with single attribute assignment
+  evaluation order. With this code:
+
+    ```ruby
+    foo::BAR = baz
+    ```
+
+    `foo` is now called before `baz`. Similarly, for multiple assignments
+    to constants,  left-to-right evaluation order is used. With this
+    code:
+
+    ```ruby
+    foo1::BAR1, foo2::BAR2 = baz1, baz2
+    ```
+
+    The following evaluation order is now used:
+
+    1. `foo1`
+    2. `foo2`
+    3. `baz1`
+    4. `baz2`
+
+    [[Bug #15928]]
+
+* "Find pattern" is no longer experimental.
+  [[Feature #18585]]
+
+* Methods taking a rest parameter (like `*args`) and wishing to delegate keyword
+  arguments through `foo(*args)` must now be marked with `ruby2_keywords`
+  (if not already the case). In other words, all methods wishing to delegate
+  keyword arguments through `*args` must now be marked with `ruby2_keywords`,
+  with no exception. This will make it easier to transition to other ways of
+  delegation once a library can require Ruby 3+. Previously, the `ruby2_keywords`
+  flag was kept if the receiving method took `*args`, but this was a bug and an
+  inconsistency. A good technique to find the potentially-missing `ruby2_keywords`
+  is to run the test suite, for where it fails find the last method which must
+  receive keyword arguments, use `puts nil, caller, nil` there, and check each
+  method/block on the call chain which must delegate keywords is correctly marked
+  as `ruby2_keywords`. [[Bug #18625]] [[Bug #16466]]
+
+    ```ruby
+    def target(**kw)
+    end
+
+    # Accidentally worked without ruby2_keywords in Ruby 2.7-3.1, ruby2_keywords
+    # needed in 3.2+. Just like (*args, **kwargs) or (...) would be needed on
+    # both #foo and #bar when migrating away from ruby2_keywords.
+    ruby2_keywords def bar(*args)
+      target(*args)
+    end
+
+    ruby2_keywords def foo(*args)
+      bar(*args)
+    end
+
+    foo(k: 1)
+    ```
+
+## Core classes updates
+
+Note: We're only listing outstanding class updates.
+
+* Fiber
+
+    * Introduce Fiber.[] and Fiber.[]= for inheritable fiber storage.
+      Introduce Fiber#storage and Fiber#storage= (experimental) for
+      getting and resetting the current storage.  Introduce
+      `Fiber.new(storage:)` for setting the storage when creating a
+      fiber. [[Feature #19078]]
+
+        Existing Thread and Fiber local variables can be tricky to use.
+        Thread-local variables are shared between all fibers, making it
+        hard to isolate, while Fiber-local variables can be hard to
+        share.  It is often desirable to define unit of execution
+        ("execution context") such that some state is shared between all
+        fibers and threads created in that context.  This is what Fiber
+        storage provides.
+
+        ```ruby
+        def log(message)
+          puts "#{Fiber[:request_id]}: #{message}"
+        end
+
+        def handle_requests
+          while request = read_request
+            Fiber.schedule do
+              Fiber[:request_id] = SecureRandom.uuid
+
+              request.messages.each do |message|
+                Fiber.schedule do
+                  log("Handling #{message}") # Log includes inherited request_id.
+                end
+              end
+            end
+          end
+        end
+        ```
+
+        You should generally consider Fiber storage for any state which
+        you want to be shared implicitly between all fibers and threads
+        created in a given context, e.g. a connection pool, a request
+        id, a logger level, environment variables, configuration, etc.
+
+* Fiber::Scheduler
+
+    * Introduce `Fiber::Scheduler#io_select` for non-blocking IO.select.
+      [[Feature #19060]]
+
+* IO
+
+    * Introduce IO#timeout= and IO#timeout which can cause
+      IO::TimeoutError to be raised if a blocking operation exceeds the
+      specified timeout. [[Feature #18630]]
+
+        ```ruby
+        STDIN.timeout = 1
+        STDIN.read # => Blocking operation timed out! (IO::TimeoutError)
+        ```
+
+    * Introduce `IO.new(..., path:)` and promote `File#path` to `IO#path`.
+      [[Feature #19036]]
+
+* Class
+
+    * Class#attached_object, which returns the object for which
+      the receiver is the singleton class. Raises TypeError if the
+      receiver is not a singleton class.
+      [[Feature #12084]]
+
+        ```ruby
+        class Foo; end
+
+        Foo.singleton_class.attached_object        #=> Foo
+        Foo.new.singleton_class.attached_object    #=> #<Foo:0x000000010491a370>
+        Foo.attached_object                        #=> TypeError: `Foo' is not a singleton class
+        nil.singleton_class.attached_object        #=> TypeError: `NilClass' is not a singleton class
+        ```
+
+* Data
+
+    * New core class to represent simple immutable value object. The class is
+      similar to Struct and partially shares an implementation, but has more
+      lean and strict API. [[Feature #16122]]
+
+        ```ruby
+        Measure = Data.define(:amount, :unit)
+        distance = Measure.new(100, 'km')            #=> #<data Measure amount=100, unit="km">
+        weight = Measure.new(amount: 50, unit: 'kg') #=> #<data Measure amount=50, unit="kg">
+        weight.with(amount: 40)                      #=> #<data Measure amount=40, unit="kg">
+        weight.amount                                #=> 50
+        weight.amount = 40                           #=> NoMethodError: undefined method `amount='
+        ```
+
+* Encoding
+
+    * Encoding#replicate has been deprecated and will be removed in 3.3. [[Feature #18949]]
+    * The dummy `Encoding::UTF_16` and `Encoding::UTF_32` encodings no longer
+      try to dynamically guess the endian based on a byte order mark.
+      Use `Encoding::UTF_16BE`/`UTF_16LE` and `Encoding::UTF_32BE`/`UTF_32LE` instead.
+      This change speeds up getting the encoding of a String. [[Feature #18949]]
+    * Limit maximum encoding set size by 256.
+      If exceeding maximum size, `EncodingError` will be raised. [[Feature #18949]]
+
+* Enumerator
+
+    * Enumerator.product has been added.  Enumerator::Product is the implementation. [[Feature #18685]]
+
+* Exception
+
+    * Exception#detailed_message has been added.
+      The default error printer calls this method on the Exception object
+      instead of #message. [[Feature #18564]]
+
+* Hash
+
+    * Hash#shift now always returns nil if the hash is
+      empty, instead of returning the default value or
+      calling the default proc. [[Bug #16908]]
+
+* Integer
+
+    * Integer#ceildiv has been added. [[Feature #18809]]
+
+* Kernel
+
+    * Kernel#binding raises RuntimeError if called from a non-Ruby frame
+      (such as a method defined in C). [[Bug #18487]]
+
+* MatchData
+
+    * MatchData#byteoffset has been added. [[Feature #13110]]
+    * MatchData#deconstruct has been added. [[Feature #18821]]
+    * MatchData#deconstruct_keys has been added. [[Feature #18821]]
+
+* Module
+
+    * Module.used_refinements has been added. [[Feature #14332]]
+    * Module#refinements has been added. [[Feature #12737]]
+    * Module#const_added has been added. [[Feature #17881]]
+    * Module#undefined_instance_methods has been added. [[Feature #12655]]
+
+* Proc
+
+    * Proc#dup returns an instance of subclass. [[Bug #17545]]
+    * Proc#parameters now accepts lambda keyword. [[Feature #15357]]
+
+* Process
+    * Added `RLIMIT_NPTS` constant to FreeBSD platform
+
+* Regexp
+
+    * The cache-based optimization is introduced.
+      Many (but not all) Regexp matching is now in linear time, which
+      will prevent regular expression denial of service (ReDoS)
+      vulnerability. [[Feature #19104]]
+
+    * Regexp.linear_time? is introduced. [[Feature #19194]]
+
+    * Regexp.new now supports passing the regexp flags not only as an Integer,
+      but also as a String.  Unknown flags raise ArgumentError.
+      Otherwise, anything other than `true`, `false`, `nil` or Integer will be warned.
+      [[Feature #18788]]
+
+    * Regexp.timeout= has been added. Also, Regexp.new new supports timeout keyword.
+      See [[Feature #17837]]
+
+* Refinement
+
+    * Refinement#refined_class has been added. [[Feature #12737]]
+
+* RubyVM::AbstractSyntaxTree
+
+    * Add `error_tolerant` option for `parse`, `parse_file` and `of`. [[Feature #19013]]
+      With this option
+
+        1. SyntaxError is suppressed
+        2. AST is returned for invalid input
+        3. `end` is complemented when a parser reaches to the end of input but `end` is insufficient
+        4. `end` is treated as keyword based on indent
+
+        ```ruby
+        # Without error_tolerant option
+        root = RubyVM::AbstractSyntaxTree.parse(<<~RUBY)
+        def m
+          a = 10
+          if
+        end
+        RUBY
+        # => <internal:ast>:33:in `parse': syntax error, unexpected `end' (SyntaxError)
+
+        # With error_tolerant option
+        root = RubyVM::AbstractSyntaxTree.parse(<<~RUBY, error_tolerant: true)
+        def m
+          a = 10
+          if
+        end
+        RUBY
+        p root # => #<RubyVM::AbstractSyntaxTree::Node:SCOPE@1:0-4:3>
+
+        # `end` is treated as keyword based on indent
+        root = RubyVM::AbstractSyntaxTree.parse(<<~RUBY, error_tolerant: true)
+        module Z
+          class Foo
+            foo.
+          end
+
+          def bar
+          end
+        end
+        RUBY
+        p root.children[-1].children[-1].children[-1].children[-2..-1]
+        # => [#<RubyVM::AbstractSyntaxTree::Node:CLASS@2:2-4:5>, #<RubyVM::AbstractSyntaxTree::Node:DEFN@6:2-7:5>]
+        ```
+
+    * Add `keep_tokens` option for `parse`, `parse_file` and `of`. Add `#tokens` and `#all_tokens`
+      for RubyVM::AbstractSyntaxTree::Node [[Feature #19070]]
+
+        ```ruby
+        root = RubyVM::AbstractSyntaxTree.parse("x = 1 + 2", keep_tokens: true)
+        root.tokens # => [[0, :tIDENTIFIER, "x", [1, 0, 1, 1]], [1, :tSP, " ", [1, 1, 1, 2]], ...]
+        root.tokens.map{_1[2]}.join # => "x = 1 + 2"
+        ```
+
+* Set
+
+    * Set is now available as a built-in class without the need for `require "set"`. [[Feature #16989]]
+      It is currently autoloaded via the Set constant or a call to Enumerable#to_set.
+
+* String
+
+    * String#byteindex and String#byterindex have been added. [[Feature #13110]]
+    * Update Unicode to Version 15.0.0 and Emoji Version 15.0. [[Feature #18639]]
+      (also applies to Regexp)
+    * String#bytesplice has been added.  [[Feature #18598]]
+    * String#dedup has been added as an alias to String#-@.  [[Feature #18595]]
+
+* Struct
+
+    * A Struct class can also be initialized with keyword arguments
+      without `keyword_init: true` on Struct.new [[Feature #16806]]
+
+        ```ruby
+        Post = Struct.new(:id, :name)
+        Post.new(1, "hello") #=> #<struct Post id=1, name="hello">
+        # From Ruby 3.2, the following code also works without keyword_init: true.
+        Post.new(id: 1, name: "hello") #=> #<struct Post id=1, name="hello">
+        ```
+
+* Thread
+
+    * Thread.each_caller_location is added. [[Feature #16663]]
+
+* Thread::Queue
+
+    * Thread::Queue#pop(timeout: sec) is added. [[Feature #18774]]
+
+* Thread::SizedQueue
+
+    * Thread::SizedQueue#pop(timeout: sec) is added. [[Feature #18774]]
+    * Thread::SizedQueue#push(timeout: sec) is added. [[Feature #18944]]
+
+* Time
+
+    * Time#deconstruct_keys is added, allowing to use Time instances
+      in pattern-matching expressions [[Feature #19071]]
+
+    * Time.new now can parse a string like generated by Time#inspect
+      and return a Time instance based on the given argument.
+      [[Feature #18033]]
+
+* SyntaxError
+    * SyntaxError#path has been added.  [[Feature #19138]]
+
+* TracePoint
+
+    * TracePoint#binding now returns `nil` for `c_call`/`c_return` TracePoints.
+      [[Bug #18487]]
+    * TracePoint#enable `target_thread` keyword argument now defaults to the
+      current thread if a block is given and `target` and `target_line` keyword
+      arguments are not passed. [[Bug #16889]]
+
+* UnboundMethod
+
+    * `UnboundMethod#==` returns `true` if the actual method is same. For example,
+      `String.instance_method(:object_id) == Array.instance_method(:object_id)`
+      returns `true`. [[Feature #18798]]
+
+    * `UnboundMethod#inspect` does not show the receiver of `instance_method`.
+      For example `String.instance_method(:object_id).inspect` returns
+      `"#<UnboundMethod: Kernel#object_id()>"`
+      (was `"#<UnboundMethod: String(Kernel)#object_id()>"`).
+
+* GC
+
+    * Expose `need_major_gc` via `GC.latest_gc_info`. [GH-6791]
+
+* ObjectSpace
+
+    * `ObjectSpace.dump_all` dump shapes as well. [GH-6868]
+
+## Stdlib updates
+
+* Bundler
+
+    * Bundler now uses [PubGrub] resolver instead of [Molinillo] for performance improvement.
+    * Add --ext=rust support to bundle gem for creating simple gems with Rust extensions.
+      [[GH-rubygems-6149]]
+    * Make cloning git repos faster [[GH-rubygems-4475]]
+
+* RubyGems
+
+    * Add mswin support for cargo builder. [[GH-rubygems-6167]]
+
+* CGI
+
+    * `CGI.escapeURIComponent` and `CGI.unescapeURIComponent` are added.
+      [[Feature #18822]]
+
+* Coverage
+
+    * `Coverage.setup` now accepts `eval: true`. By this, `eval` and related methods are
+      able to generate code coverage. [[Feature #19008]]
+
+    * `Coverage.supported?(mode)` enables detection of what coverage modes are
+      supported. [[Feature #19026]]
+
+* Date
+
+    * Added `Date#deconstruct_keys` and `DateTime#deconstruct_keys` same as [[Feature #19071]]
+
+* ERB
+
+    * `ERB::Util.html_escape` is made faster than `CGI.escapeHTML`.
+        * It no longer allocates a String object when no character needs to be escaped.
+        * It skips calling `#to_s` method when an argument is already a String.
+        * `ERB::Escape.html_escape` is added as an alias to `ERB::Util.html_escape`,
+          which has not been monkey-patched by Rails.
+    * `ERB::Util.url_encode` is made faster using `CGI.escapeURIComponent`.
+    * `-S` option is removed from `erb` command.
+
+* FileUtils
+
+    * Add FileUtils.ln_sr method and `relative:` option to FileUtils.ln_s.
+      [[Feature #18925]]
+
+* IRB
+
+    * debug.gem integration commands have been added: `debug`, `break`, `catch`,
+      `next`, `delete`, `step`, `continue`, `finish`, `backtrace`, `info`
+        * They work even if you don't have `gem "debug"` in your Gemfile.
+        * See also: [What's new in Ruby 3.2's IRB?](https://st0012.dev/whats-new-in-ruby-3-2-irb)
+    * More Pry-like commands and features have been added.
+        * `edit` and `show_cmds` (like Pry's `help`) are added.
+        * `ls` takes `-g` or `-G` option to filter out outputs.
+        * `show_source` is aliased from `$` and accepts unquoted inputs.
+        * `whereami` is aliased from `@`.
+
+* Net::Protocol
+
+    * Improve `Net::BufferedIO` performance. [[GH-net-protocol-14]]
+
+* Pathname
+
+    * Added `Pathname#lutime`. [[GH-pathname-20]]
+
+* Socket
+
+    * Added the following constants for supported platforms.
+        * `SO_INCOMING_CPU`
+        * `SO_INCOMING_NAPI_ID`
+        * `SO_RTABLE`
+        * `SO_SETFIB`
+        * `SO_USER_COOKIE`
+        * `TCP_KEEPALIVE`
+        * `TCP_CONNECTION_INFO`
+
+* SyntaxSuggest
+
+    * The feature of `syntax_suggest` formerly `dead_end` is integrated in Ruby.
+      [[Feature #18159]]
+
+* UNIXSocket
+
+    * Add support for UNIXSocket on Windows. Emulate anonymous sockets. Add
+      support for File.socket? and File::Stat#socket? where possible.
+      [[Feature #19135]]
+
+*   The following default gems are updated.
+
+    * RubyGems 3.4.1
+    * abbrev 0.1.1
+    * benchmark 0.2.1
+    * bigdecimal 3.1.3
+    * bundler 2.4.1
+    * cgi 0.3.6
+    * csv 3.2.6
+    * date 3.3.3
+    * delegate 0.3.0
+    * did_you_mean 1.6.3
+    * digest 3.1.1
+    * drb 2.1.1
+    * english 0.7.2
+    * erb 4.0.2
+    * error_highlight 0.5.1
+    * etc 1.4.2
+    * fcntl 1.0.2
+    * fiddle 1.1.1
+    * fileutils 1.7.0
+    * forwardable 1.3.3
+    * getoptlong 0.2.0
+    * io-console 0.6.0
+    * io-nonblock 0.2.0
+    * io-wait 0.3.0
+    * ipaddr 1.2.5
+    * irb 1.6.2
+    * json 2.6.3
+    * logger 1.5.3
+    * mutex_m 0.1.2
+    * net-http 0.4.0
+    * net-protocol 0.2.1
+    * nkf 0.1.2
+    * open-uri 0.3.0
+    * open3 0.1.2
+    * openssl 3.1.0
+    * optparse 0.3.1
+    * ostruct 0.5.5
+    * pathname 0.2.1
+    * pp 0.4.0
+    * pstore 0.1.2
+    * psych 5.0.1
+    * racc 1.6.2
+    * rdoc 6.5.0
+    * readline-ext 0.1.5
+    * reline 0.3.2
+    * resolv 0.2.2
+    * resolv-replace 0.1.1
+    * securerandom 0.2.2
+    * set 1.0.3
+    * stringio 3.0.4
+    * strscan 3.0.5
+    * syntax_suggest 1.0.2
+    * syslog 0.1.1
+    * tempfile 0.1.3
+    * time 0.2.1
+    * timeout 0.3.1
+    * tmpdir 0.1.3
+    * tsort 0.1.1
+    * un 0.2.1
+    * uri 0.12.0
+    * weakref 0.1.2
+    * win32ole 1.8.9
+    * yaml 0.2.1
+    * zlib 3.0.0
+
+*   The following bundled gems are updated.
+
+    * minitest 5.16.3
+    * power_assert 2.0.3
+    * test-unit 3.5.7
+    * net-ftp 0.2.0
+    * net-imap 0.3.4
+    * net-pop 0.1.2
+    * net-smtp 0.3.3
+    * rbs 2.8.2
+    * typeprof 0.21.3
+    * debug 1.7.1
+
+See GitHub releases like [GitHub Releases of Logger](https://github.com/ruby/logger/releases) or changelog for details of the default gems or bundled gems.
+
+## Supported platforms
+
+* WebAssembly/WASI is added. See [wasm/README.md] and [ruby.wasm] for more details. [[Feature #18462]]
+
+## Compatibility issues
+
+* `String#to_c` currently treat a sequence of underscores as an end of Complex
+  string. [[Bug #19087]]
+
+* Now `ENV.clone` raises `TypeError` as well as `ENV.dup` [[Bug #17767]]
+
+### Removed constants
+
+The following deprecated constants are removed.
+
+* `Fixnum` and `Bignum` [[Feature #12005]]
+* `Random::DEFAULT` [[Feature #17351]]
+* `Struct::Group`
+* `Struct::Passwd`
+
+### Removed methods
+
+The following deprecated methods are removed.
+
+* `Dir.exists?` [[Feature #17391]]
+* `File.exists?` [[Feature #17391]]
+* `Kernel#=~` [[Feature #15231]]
+* `Kernel#taint`, `Kernel#untaint`, `Kernel#tainted?`
+  [[Feature #16131]]
+* `Kernel#trust`, `Kernel#untrust`, `Kernel#untrusted?`
+  [[Feature #16131]]
+* `Method#public?`, `Method#private?`, `Method#protected?`,
+  `UnboundMethod#public?`, `UnboundMethod#private?`, `UnboundMethod#protected?`
+  [[Bug #18729]] [[Bug #18751]] [[Bug #18435]]
+
+### Source code incompatibility of extension libraries
+
+* Extension libraries provide PRNG, subclasses of Random, need updates.
+  See [PRNG update] below for more information. [[Bug #19100]]
+
+### Error printer
+
+* Ruby no longer escapes control characters and backslashes in an
+  error message. [[Feature #18367]]
+
+### Constant lookup when defining a class/module
+
+* When defining a class/module directly under the Object class by class/module
+  statement, if there is already a class/module defined by `Module#include`
+  with the same name, the statement was handled as "open class" in Ruby 3.1 or before.
+  Since Ruby 3.2, a new class is defined instead. [[Feature #18832]]
+
+## Stdlib compatibility issues
+
+* Psych no longer bundles libyaml sources.
+  And also Fiddle no longer bundles libffi sources.
+  Users need to install the libyaml/libffi library themselves via the package
+  manager like apt, yum, brew, etc.
+
+    Psych and fiddle supported the static build with specific version of libyaml
+    and libffi sources. You can build psych with libyaml-0.2.5 like this.
+
+    ```bash
+    $ ./configure --with-libyaml-source-dir=/path/to/libyaml-0.2.5
+    ```
+
+    And you can build fiddle with libffi-3.4.4 like this.
+
+    ```bash
+    $ ./configure --with-libffi-source-dir=/path/to/libffi-3.4.4
+    ```
+
+    [[Feature #18571]]
+
+* Check cookie name/path/domain characters in `CGI::Cookie`. [[CVE-2021-33621]]
+
+* `URI.parse` return empty string in host instead of nil. [[sec-156615]]
+
+## C API updates
+
+### Updated C APIs
+
+The following APIs are updated.
+
+* PRNG update
+
+    `rb_random_interface_t` in ruby/random.h updated and versioned.
+    Extension libraries which use this interface and built for older
+    versions need to rebuild with adding `init_int32` function.
+
+### Added C APIs
+
+* `VALUE rb_hash_new_capa(long capa)` was added to created hashes with the desired capacity.
+* `rb_internal_thread_add_event_hook` and `rb_internal_thread_add_event_hook` were added to instrument threads scheduling.
+  The following events are available:
+    * `RUBY_INTERNAL_THREAD_EVENT_STARTED`
+    * `RUBY_INTERNAL_THREAD_EVENT_READY`
+    * `RUBY_INTERNAL_THREAD_EVENT_RESUMED`
+    * `RUBY_INTERNAL_THREAD_EVENT_SUSPENDED`
+    * `RUBY_INTERNAL_THREAD_EVENT_EXITED`
+* `rb_debug_inspector_current_depth` and `rb_debug_inspector_frame_depth` are added for debuggers.
+
+### Removed C APIs
+
+The following deprecated APIs are removed.
+
+* `rb_cData` variable.
+* "taintedness" and "trustedness" functions. [[Feature #16131]]
+
+## Implementation improvements
+
+* Fixed several race conditions in Kernel#autoload. [[Bug #18782]]
+* Cache invalidation for expressions referencing constants is now
+  more fine-grained. `RubyVM.stat(:global_constant_state)` was
+  removed because it was closely tied to the previous caching scheme
+  where setting any constant invalidates all caches in the system.
+  New keys, `:constant_cache_invalidations` and `:constant_cache_misses`,
+  were introduced to help with use cases for `:global_constant_state`.
+  [[Feature #18589]]
+* The cache-based optimization for Regexp matching is introduced.
+  [[Feature #19104]]
+* [Variable Width Allocation](https://shopify.engineering/ruby-variable-width-allocation)
+  is now enabled by default. [[Feature #18239]]
+* Added a new instance variable caching mechanism, called object shapes, which
+  improves inline cache hits for most objects and allows us to generate very
+  efficient JIT code. Objects whose instance variables are defined in a
+  consistent order will see the most performance benefits.
+  [[Feature #18776]]
+* Speed up marking instruction sequences by using a bitmap to find "markable"
+  objects.  This change results in faster major collections.
+  [[Feature #18875]]
+
+## JIT
+
+### YJIT
+
+* YJIT is no longer experimental
+    * Has been tested on production workloads for over a year and proven to be quite stable.
+* YJIT now supports both x86-64 and arm64/aarch64 CPUs on Linux, MacOS, BSD and other UNIX platforms.
+    * This release brings support for Mac M1/M2, AWS Graviton and Raspberry Pi 4.
+* Building YJIT now requires Rust 1.58.0+. [[Feature #18481]]
+    * In order to ensure that CRuby is built with YJIT, please install `rustc` >= 1.58.0
+      before running `./configure`
+    * Please reach out to the YJIT team should you run into any issues.
+* Physical memory for JIT code is lazily allocated. Unlike Ruby 3.1,
+  the RSS of a Ruby process is minimized because virtual memory pages
+  allocated by `--yjit-exec-mem-size` will not be mapped to physical
+  memory pages until actually utilized by JIT code.
+* Introduce Code GC that frees all code pages when the memory consumption
+  by JIT code reaches `--yjit-exec-mem-size`.
+    * `RubyVM::YJIT.runtime_stats` returns Code GC metrics in addition to
+      existing `inline_code_size` and `outlined_code_size` keys:
+      `code_gc_count`, `live_page_count`, `freed_page_count`, and `freed_code_size`.
+* Most of the statistics produced by `RubyVM::YJIT.runtime_stats` are now available in release builds.
+    * Simply run ruby with `--yjit-stats` to compute and dump stats (incurs some run-time overhead).
+* YJIT is now optimized to take advantage of object shapes. [[Feature #18776]]
+* Take advantage of finer-grained constant invalidation to invalidate less code when defining new constants. [[Feature #18589]]
+* The default `--yjit-exec-mem-size` is changed to 64 (MiB).
+* The default `--yjit-call-threshold` is changed to 30.
+
+### MJIT
+
+* The MJIT compiler is re-implemented in Ruby as `ruby_vm/mjit/compiler`.
+* MJIT compiler is executed under a forked Ruby process instead of
+  doing it in a native thread called MJIT worker. [[Feature #18968]]
+    * As a result, Microsoft Visual Studio (MSWIN) is no longer supported.
+* MinGW is no longer supported. [[Feature #18824]]
+* Rename `--mjit-min-calls` to `--mjit-call-threshold`.
+* Change default `--mjit-max-cache` back from 10000 to 100.
+
+[Feature #12005]:     https://bugs.ruby-lang.org/issues/12005
+[Feature #12084]:     https://bugs.ruby-lang.org/issues/12084
+[Feature #12655]:     https://bugs.ruby-lang.org/issues/12655
+[Feature #12737]:     https://bugs.ruby-lang.org/issues/12737
+[Feature #13110]:     https://bugs.ruby-lang.org/issues/13110
+[Feature #14332]:     https://bugs.ruby-lang.org/issues/14332
+[Feature #15231]:     https://bugs.ruby-lang.org/issues/15231
+[Feature #15357]:     https://bugs.ruby-lang.org/issues/15357
+[Bug #15928]:         https://bugs.ruby-lang.org/issues/15928
+[Feature #16122]:     https://bugs.ruby-lang.org/issues/16122
+[Feature #16131]:     https://bugs.ruby-lang.org/issues/16131
+[Bug #16466]:         https://bugs.ruby-lang.org/issues/16466
+[Feature #16663]:     https://bugs.ruby-lang.org/issues/16663
+[Feature #16806]:     https://bugs.ruby-lang.org/issues/16806
+[Bug #16889]:         https://bugs.ruby-lang.org/issues/16889
+[Bug #16908]:         https://bugs.ruby-lang.org/issues/16908
+[Feature #16989]:     https://bugs.ruby-lang.org/issues/16989
+[Feature #17351]:     https://bugs.ruby-lang.org/issues/17351
+[Feature #17391]:     https://bugs.ruby-lang.org/issues/17391
+[Bug #17545]:         https://bugs.ruby-lang.org/issues/17545
+[Bug #17767]:         https://bugs.ruby-lang.org/issues/17767
+[Feature #17837]:     https://bugs.ruby-lang.org/issues/17837
+[Feature #17881]:     https://bugs.ruby-lang.org/issues/17881
+[Feature #18033]:     https://bugs.ruby-lang.org/issues/18033
+[Feature #18159]:     https://bugs.ruby-lang.org/issues/18159
+[Feature #18239]:     https://bugs.ruby-lang.org/issues/18239#note-17
+[Feature #18351]:     https://bugs.ruby-lang.org/issues/18351
+[Feature #18367]:     https://bugs.ruby-lang.org/issues/18367
+[Bug #18435]:         https://bugs.ruby-lang.org/issues/18435
+[Feature #18462]:     https://bugs.ruby-lang.org/issues/18462
+[Feature #18481]:     https://bugs.ruby-lang.org/issues/18481
+[Bug #18487]:         https://bugs.ruby-lang.org/issues/18487
+[Feature #18564]:     https://bugs.ruby-lang.org/issues/18564
+[Feature #18571]:     https://bugs.ruby-lang.org/issues/18571
+[Feature #18585]:     https://bugs.ruby-lang.org/issues/18585
+[Feature #18589]:     https://bugs.ruby-lang.org/issues/18589
+[Feature #18595]:     https://bugs.ruby-lang.org/issues/18595
+[Feature #18598]:     https://bugs.ruby-lang.org/issues/18598
+[Bug #18625]:         https://bugs.ruby-lang.org/issues/18625
+[Feature #18630]:     https://bugs.ruby-lang.org/issues/18630
+[Bug #18633]:         https://bugs.ruby-lang.org/issues/18633
+[Feature #18639]:     https://bugs.ruby-lang.org/issues/18639
+[Feature #18685]:     https://bugs.ruby-lang.org/issues/18685
+[Bug #18729]:         https://bugs.ruby-lang.org/issues/18729
+[Bug #18751]:         https://bugs.ruby-lang.org/issues/18751
+[Feature #18774]:     https://bugs.ruby-lang.org/issues/18774
+[Feature #18776]:     https://bugs.ruby-lang.org/issues/18776
+[Bug #18782]:         https://bugs.ruby-lang.org/issues/18782
+[Feature #18788]:     https://bugs.ruby-lang.org/issues/18788
+[Feature #18798]:     https://bugs.ruby-lang.org/issues/18798
+[Feature #18809]:     https://bugs.ruby-lang.org/issues/18809
+[Feature #18821]:     https://bugs.ruby-lang.org/issues/18821
+[Feature #18822]:     https://bugs.ruby-lang.org/issues/18822
+[Feature #18824]:     https://bugs.ruby-lang.org/issues/18824
+[Feature #18832]:     https://bugs.ruby-lang.org/issues/18832
+[Feature #18875]:     https://bugs.ruby-lang.org/issues/18875
+[Feature #18925]:     https://bugs.ruby-lang.org/issues/18925
+[Feature #18944]:     https://bugs.ruby-lang.org/issues/18944
+[Feature #18949]:     https://bugs.ruby-lang.org/issues/18949
+[Feature #18968]:     https://bugs.ruby-lang.org/issues/18968
+[Feature #19008]:     https://bugs.ruby-lang.org/issues/19008
+[Feature #19013]:     https://bugs.ruby-lang.org/issues/19013
+[Feature #19026]:     https://bugs.ruby-lang.org/issues/19026
+[Feature #19036]:     https://bugs.ruby-lang.org/issues/19036
+[Feature #19060]:     https://bugs.ruby-lang.org/issues/19060
+[Feature #19070]:     https://bugs.ruby-lang.org/issues/19070
+[Feature #19071]:     https://bugs.ruby-lang.org/issues/19071
+[Feature #19078]:     https://bugs.ruby-lang.org/issues/19078
+[Bug #19087]:         https://bugs.ruby-lang.org/issues/19087
+[Bug #19100]:         https://bugs.ruby-lang.org/issues/19100
+[Feature #19104]:     https://bugs.ruby-lang.org/issues/19104
+[Feature #19135]:     https://bugs.ruby-lang.org/issues/19135
+[Feature #19138]:     https://bugs.ruby-lang.org/issues/19138
+[Feature #19194]:     https://bugs.ruby-lang.org/issues/19194
+[Molinillo]:          https://github.com/CocoaPods/Molinillo
+[PubGrub]:            https://github.com/jhawthorn/pub_grub
+[GH-net-protocol-14]: https://github.com/ruby/net-protocol/pull/14
+[GH-pathname-20]:     https://github.com/ruby/pathname/pull/20
+[GH-6791]:            https://github.com/ruby/ruby/pull/6791
+[GH-6868]:            https://github.com/ruby/ruby/pull/6868
+[GH-rubygems-4475]:   https://github.com/rubygems/rubygems/pull/4475
+[GH-rubygems-6149]:   https://github.com/rubygems/rubygems/pull/6149
+[GH-rubygems-6167]:   https://github.com/rubygems/rubygems/pull/6167
+[sec-156615]:         https://hackerone.com/reports/156615
+[CVE-2021-33621]:     https://www.ruby-lang.org/en/news/2022/11/22/http-response-splitting-in-cgi-cve-2021-33621/
+[wasm/README.md]:     https://github.com/ruby/ruby/blob/master/wasm/README.md
+[ruby.wasm]:          https://github.com/ruby/ruby.wasm
diff --git a/README.ja.md b/README.ja.md
index 1b45c67819..93c0131690 100644
--- a/README.ja.md
+++ b/README.ja.md
@@ -1,8 +1,9 @@
-[![Build Status](https://travis-ci.org/ruby/ruby.svg?branch=master)](https://travis-ci.org/ruby/ruby)
-[![wercker status](https://app.wercker.com/status/e5e7e1704f62b76525022aa424aef6ef/s/master "wercker status")](https://app.wercker.com/project/byKey/e5e7e1704f62b76525022aa424aef6ef)
-[![Build status](https://ci.appveyor.com/api/projects/status/0sy8rrxut4o0k960/branch/master?svg=true)](https://ci.appveyor.com/project/ruby/ruby/branch/master)
-[![Build Status](https://dev.azure.com/rubylang/ruby/_apis/build/status/ruby.ruby?branchName=master)](https://dev.azure.com/rubylang/ruby/_build/latest?definitionId=3&branchName=master)
-
+[![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)
 
 # Rubyとは
 
@@ -50,11 +51,11 @@ Rubyリポジトリの本来のmasterは https://git.ruby-lang.org/ruby.git に�
 
 ### Subversion
 
-古いRubyのバージョンのソースコードは次のコマンドで取得できます．
+古いRubyのバージョンのソースコードは次のコマンドでも取得できます．
 
     $ svn co https://svn.ruby-lang.org/repos/ruby/branches/ruby_2_6/ ruby
 
-他に開発中のブランチの一覧は次のコマンドで見られます．
+他のブランチの一覧は次のコマンドで見られます．
 
     $ svn ls https://svn.ruby-lang.org/repos/ruby/branches/
 
@@ -69,38 +70,33 @@ 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
-
-mailto: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@ruby-lang.org] まで本文に
 
     subscribe
 
 と書いて送って下さい．
 
-Ruby開発者向けメーリングリストもあります．こちらではrubyのバグ，将来の仕様拡張など実装上の問題について議論されています． 参加希望の方は
-
-mailto:ruby-dev-request@ruby-lang.org
-
-までruby-listと同様の方法でメールしてください．
+Ruby開発者向けメーリングリストもあります．こちらではrubyのバグ，将来の仕様拡張など実装上の問題について議論されています．
+参加希望の方は [ruby-dev-request@ruby-lang.org] までruby-listと同様の方法でメールしてください．
 
 Ruby拡張モジュールについて話し合うruby-extメーリングリストと数学関係の話題について話し合うruby-mathメーリングリストと
 英語でrubyについて話し合うruby-talkメーリングリストもあります．参加方法はどれも同じです．
 
+[ruby-list-request@ruby-lang.org]: mailto:ruby-list-request@ruby-lang.org?subject=Join%20Ruby%20Mailing%20List&body=subscribe
+[ruby-dev-request@ruby-lang.org]: mailto:ruby-dev-request@ruby-lang.org?subject=Join%20Ruby%20Mailing%20List&body=subscribe
+
 ## コンパイル・インストール
 
 以下の手順で行ってください．
 
-1.  もし `configure` ファイルが見つからない，もしくは `configure.ac` より古いようなら， `autoconf` を実行して
-    新しく `configure` を生成する
+1.  (Gitリポジトリから取得したソースをビルドする場合) `./autogen.sh` を実行して新しく `configure` を生成する
 
 2.  `configure` を実行して `Makefile` などを生成する
 
     環境によってはデフォルトのCコンパイラ用オプションが付きます． `configure` オプションで `optflags=..`
     `warnflags=..` 等で上書きできます．
 
-3.  (必要ならば)`defines.h` を編集する
+3.  (必要ならば)`include/ruby/defines.h` を編集する
 
     多分，必要無いと思います．
 
@@ -170,11 +166,14 @@ UNIXであれば `configure` がほとんどの差異を吸収してくれるは
 
 ## フィードバック
 
-Rubyに関する質問は Ruby-Talk（英語）や Ruby-List（日本語） (https://www.ruby-lang.org/ja/community/mailing-lists) や，
-stackoverflow (https://ja.stackoverflow.com/) などのWebサイトに投稿してください．
+Rubyに関する質問は [Ruby-Talk]（英語）や [Ruby-List]（日本語）や，
+[stackoverflow] などのWebサイトに投稿してください．
 
 バグ報告は https://bugs.ruby-lang.org で受け付けています．
 
+[Ruby-Talk]: https://www.ruby-lang.org/en/community/mailing-lists
+[Ruby-List]: https://www.ruby-lang.org/ja/community/mailing-lists
+[stackoverflow]: https://ja.stackoverflow.com/
 
 ## 著者
 
diff --git a/README.md b/README.md
index 0e4786ba78..c445448c71 100644
--- a/README.md
+++ b/README.md
@@ -1,9 +1,11 @@
-[![Build Status](https://travis-ci.org/ruby/ruby.svg?branch=master)](https://travis-ci.org/ruby/ruby)
-[![wercker status](https://app.wercker.com/status/e5e7e1704f62b76525022aa424aef6ef/s/master "wercker status")](https://app.wercker.com/project/byKey/e5e7e1704f62b76525022aa424aef6ef)
-[![Build status](https://ci.appveyor.com/api/projects/status/0sy8rrxut4o0k960/branch/master?svg=true)](https://ci.appveyor.com/project/ruby/ruby/branch/master)
-[![Build Status](https://dev.azure.com/rubylang/ruby/_apis/build/status/ruby.ruby?branchName=master)](https://dev.azure.com/rubylang/ruby/_build/latest?definitionId=3&branchName=master)
+[![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)
 
-# What's Ruby
+# What is Ruby?
 
 Ruby is an interpreted object-oriented programming language often
 used for web development. It also offers many scripting features
@@ -12,28 +14,25 @@ It is simple, straightforward, and extensible.
 
 ## Features of Ruby
 
-*   Simple Syntax
-*   **Normal** Object-oriented Features (e.g. class, method calls)
-*   **Advanced** Object-oriented Features (e.g. mix-in, singleton-method)
-*   Operator Overloading
-*   Exception Handling
-*   Iterators and Closures
-*   Garbage Collection
-*   Dynamic Loading of Object Files (on some architectures)
-*   Highly Portable (works on many Unix-like/POSIX compatible platforms as
-    well as Windows, macOS, Haiku, etc.) cf.
-    https://github.com/ruby/ruby/blob/master/doc/contributing.rdoc#platform-maintainers
+* Simple Syntax
+* **Normal** Object-oriented Features (e.g. class, method calls)
+* **Advanced** Object-oriented Features (e.g. mix-in, singleton-method)
+* Operator Overloading
+* Exception Handling
+* Iterators and Closures
+* Garbage Collection
+* Dynamic Loading of Object Files (on some architectures)
+* Highly Portable (works on many Unix-like/POSIX compatible platforms as
+  well as Windows, macOS, etc.) cf.
+  https://github.com/ruby/ruby/blob/master/doc/maintainers.rdoc#label-Platform+Maintainers
 
-
-## How to get Ruby
+## How to get Ruby with Git
 
 For a complete list of ways to install Ruby, including using third-party tools
 like rvm, see:
 
 https://www.ruby-lang.org/en/downloads/
 
-### Git
-
 The mirror of the Ruby source tree can be checked out with the following command:
 
     $ git clone https://github.com/ruby/ruby.git
@@ -46,21 +45,19 @@ to see the list of branches:
 You may also want to use https://git.ruby-lang.org/ruby.git (actual master of Ruby source)
 if you are a committer.
 
-### Subversion
-
-Stable branches for older Ruby versions can be checked out with the following command:
-
-    $ svn co https://svn.ruby-lang.org/repos/ruby/branches/ruby_2_6/ ruby
-
-Try the following command to see the list of branches:
-
-    $ svn ls https://svn.ruby-lang.org/repos/ruby/branches/
+## How to build
 
+see [Building Ruby](doc/contributing/building_ruby.md)
 
 ## Ruby home page
 
 https://www.ruby-lang.org/
 
+## Documentation
+
+- [English](https://docs.ruby-lang.org/en/master/index.html)
+- [Japanese](https://docs.ruby-lang.org/ja/master/index.html)
+
 ## Mailing list
 
 There is a mailing list to discuss Ruby. To subscribe to this list, please
@@ -68,103 +65,24 @@ send the following phrase:
 
     subscribe
 
-in the mail body (not subject) to the address
-[ruby-talk-request@ruby-lang.org](mailto:ruby-talk-request@ruby-lang.org?subject=Join%20Ruby%20Mailing%20List&body=subscribe).
-
-## How to compile and install
-
-1.  If you want to use Microsoft Visual C++ to compile Ruby, read
-    [win32/README.win32](win32/README.win32) instead of this document.
-
-2.  If `./configure` does not exist or is older than `configure.ac`, run
-    `autoconf` to (re)generate configure.
-
-3.  Run `./configure`, which will generate `config.h` and `Makefile`.
-
-    Some C compiler flags may be added by default depending on your
-    environment. Specify `optflags=..` and `warnflags=..` as necessary to
-    override them.
-
-4.  Edit `defines.h` if you need. Usually this step will not be needed.
-
-5.  Remove comment mark(`#`) before the module names from `ext/Setup` (or add
-    module names if not present), if you want to link modules statically.
-
-    If you don't want to compile non static extension modules (probably on
-    architectures which do not allow dynamic loading), remove comment mark
-    from the line "`#option nodynamic`" in `ext/Setup`.
+in the mail body (not subject) to the address [ruby-talk-request@ruby-lang.org].
 
-    Usually this step will not be needed.
-
-6.  Run `make`.
-
-    * On Mac, set RUBY\_CODESIGN environment variable with a signing identity.
-      It uses the identity to sign `ruby` binary. See also codesign(1).
-
-7.  Optionally, run '`make check`' to check whether the compiled Ruby
-    interpreter works well. If you see the message "`check succeeded`", your
-    Ruby works as it should (hopefully).
-
-8.  Optionally, run `make update-gems` and `make extract-gems`.
-
-    If you want to install bundled gems, run `make update-gems` and
-    `make extract-gems` before running `make install`.
-
-9.  Run '`make install`'.
-
-    This command will create the following directories and install files into
-    them.
-
-    *   `${DESTDIR}${prefix}/bin`
-    *   `${DESTDIR}${prefix}/include/ruby-${MAJOR}.${MINOR}.${TEENY}`
-    *   `${DESTDIR}${prefix}/include/ruby-${MAJOR}.${MINOR}.${TEENY}/${PLATFORM}`
-    *   `${DESTDIR}${prefix}/lib`
-    *   `${DESTDIR}${prefix}/lib/ruby`
-    *   `${DESTDIR}${prefix}/lib/ruby/${MAJOR}.${MINOR}.${TEENY}`
-    *   `${DESTDIR}${prefix}/lib/ruby/${MAJOR}.${MINOR}.${TEENY}/${PLATFORM}`
-    *   `${DESTDIR}${prefix}/lib/ruby/site_ruby`
-    *   `${DESTDIR}${prefix}/lib/ruby/site_ruby/${MAJOR}.${MINOR}.${TEENY}`
-    *   `${DESTDIR}${prefix}/lib/ruby/site_ruby/${MAJOR}.${MINOR}.${TEENY}/${PLATFORM}`
-    *   `${DESTDIR}${prefix}/lib/ruby/vendor_ruby`
-    *   `${DESTDIR}${prefix}/lib/ruby/vendor_ruby/${MAJOR}.${MINOR}.${TEENY}`
-    *   `${DESTDIR}${prefix}/lib/ruby/vendor_ruby/${MAJOR}.${MINOR}.${TEENY}/${PLATFORM}`
-    *   `${DESTDIR}${prefix}/lib/ruby/gems/${MAJOR}.${MINOR}.${TEENY}`
-    *   `${DESTDIR}${prefix}/share/man/man1`
-    *   `${DESTDIR}${prefix}/share/ri/${MAJOR}.${MINOR}.${TEENY}/system`
-
-
-    If Ruby's API version is '*x.y.z*', the `${MAJOR}` is '*x*', the
-    `${MINOR}` is '*y*', and the `${TEENY}` is '*z*'.
-
-    **NOTE**: teeny of the API version may be different from one of Ruby's
-    program version
-
-    You may have to be a super user to install Ruby.
-
-If you fail to compile Ruby, please send the detailed error report with the
-error log and machine/OS type, to help others.
-
-Some extension libraries may not get compiled because of lack of necessary
-external libraries and/or headers, then you will need to run '`make distclean-ext`'
-to remove old configuration after installing them in such case.
+[ruby-talk-request@ruby-lang.org]: mailto:ruby-talk-request@ruby-lang.org?subject=Join%20Ruby%20Mailing%20List&body=subscribe
 
 ## Copying
 
-See the file [COPYING](COPYING).
+See the file [COPYING](rdoc-ref:COPYING).
 
 ## Feedback
 
-Questions about the Ruby language can be asked on the Ruby-Talk mailing list
-(https://www.ruby-lang.org/en/community/mailing-lists) or on websites like
-(https://stackoverflow.com).
-
-Bugs should be reported at https://bugs.ruby-lang.org. Read [HowToReport] for more information.
+Questions about the Ruby language can be asked on the [Ruby-Talk](https://www.ruby-lang.org/en/community/mailing-lists) mailing list
+or on websites like https://stackoverflow.com.
 
-[HowToReport]: https://bugs.ruby-lang.org/projects/ruby/wiki/HowToReport
+Bugs should be reported at https://bugs.ruby-lang.org. Read ["Reporting Issues"](https://docs.ruby-lang.org/en/master/contributing/reporting_issues_md.html) for more information.
 
 ## Contributing
 
-See the file [CONTRIBUTING.md](CONTRIBUTING.md)
+See ["Contributing to Ruby"](https://docs.ruby-lang.org/en/master/contributing_md.html), which includes setup and build instructions.
 
 ## The Author
 
diff --git a/aclocal.m4 b/aclocal.m4
index ed7d14ef63..e69de29bb2 100644
--- a/aclocal.m4
+++ b/aclocal.m4
@@ -1,47 +0,0 @@
-# generated automatically by aclocal 1.16.1 -*- Autoconf -*-
-
-# Copyright (C) 1996-2018 Free Software Foundation, Inc.
-
-# This file is free software; the Free Software Foundation
-# gives unlimited permission to copy and/or distribute it,
-# with or without modifications, as long as this notice is preserved.
-
-# This program is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY, to the extent permitted by law; without
-# even the implied warranty of MERCHANTABILITY or FITNESS FOR A
-# PARTICULAR PURPOSE.
-
-m4_ifndef([AC_CONFIG_MACRO_DIRS], [m4_defun([_AM_CONFIG_MACRO_DIRS], [])m4_defun([AC_CONFIG_MACRO_DIRS], [_AM_CONFIG_MACRO_DIRS($@)])])
-m4_include([tool/m4/_colorize_result_prepare.m4])
-m4_include([tool/m4/ac_msg_result.m4])
-m4_include([tool/m4/colorize_result.m4])
-m4_include([tool/m4/ruby_append_option.m4])
-m4_include([tool/m4/ruby_append_options.m4])
-m4_include([tool/m4/ruby_check_builtin_func.m4])
-m4_include([tool/m4/ruby_check_builtin_setjmp.m4])
-m4_include([tool/m4/ruby_check_printf_prefix.m4])
-m4_include([tool/m4/ruby_check_setjmp.m4])
-m4_include([tool/m4/ruby_check_signedness.m4])
-m4_include([tool/m4/ruby_check_sizeof.m4])
-m4_include([tool/m4/ruby_check_sysconf.m4])
-m4_include([tool/m4/ruby_cppoutfile.m4])
-m4_include([tool/m4/ruby_decl_attribute.m4])
-m4_include([tool/m4/ruby_default_arch.m4])
-m4_include([tool/m4/ruby_define_if.m4])
-m4_include([tool/m4/ruby_defint.m4])
-m4_include([tool/m4/ruby_dtrace_available.m4])
-m4_include([tool/m4/ruby_dtrace_postprocess.m4])
-m4_include([tool/m4/ruby_func_attribute.m4])
-m4_include([tool/m4/ruby_mingw32.m4])
-m4_include([tool/m4/ruby_prepend_option.m4])
-m4_include([tool/m4/ruby_prog_gnu_ld.m4])
-m4_include([tool/m4/ruby_replace_funcs.m4])
-m4_include([tool/m4/ruby_replace_type.m4])
-m4_include([tool/m4/ruby_rm_recursive.m4])
-m4_include([tool/m4/ruby_setjmp_type.m4])
-m4_include([tool/m4/ruby_stack_grow_direction.m4])
-m4_include([tool/m4/ruby_try_cflags.m4])
-m4_include([tool/m4/ruby_try_ldflags.m4])
-m4_include([tool/m4/ruby_type_attribute.m4])
-m4_include([tool/m4/ruby_universal_arch.m4])
-m4_include([tool/m4/ruby_werror_flag.m4])
diff --git a/addr2line.c b/addr2line.c
index 635194b96b..e5f25293e2 100644
--- a/addr2line.c
+++ b/addr2line.c
@@ -13,7 +13,7 @@
 #pragma clang diagnostic ignored "-Wgcc-compat"
 #endif
 
-#include "ruby/config.h"
+#include "ruby/internal/config.h"
 #include "ruby/defines.h"
 #include "ruby/missing.h"
 #include "addr2line.h"
@@ -25,11 +25,7 @@
 #include <libproc.h>
 #endif
 
-#ifdef HAVE_STDBOOL_H
-#include <stdbool.h>
-#else
-#include "missing/stdbool.h"
-#endif
+#include "ruby/internal/stdbool.h"
 
 #if defined(USE_ELF) || defined(HAVE_MACH_O_LOADER_H)
 
@@ -163,11 +159,15 @@ typedef struct obj_info {
     struct dwarf_section debug_info;
     struct dwarf_section debug_line;
     struct dwarf_section debug_ranges;
+    struct dwarf_section debug_str_offsets;
+    struct dwarf_section debug_addr;
+    struct dwarf_section debug_rnglists;
     struct dwarf_section debug_str;
+    struct dwarf_section debug_line_str;
     struct obj_info *next;
 } obj_info_t;
 
-#define DWARF_SECTION_COUNT 5
+#define DWARF_SECTION_COUNT 9
 
 static struct dwarf_section *
 obj_dwarf_section_at(obj_info_t *obj, int n)
@@ -177,7 +177,11 @@ obj_dwarf_section_at(obj_info_t *obj, int n)
         &obj->debug_info,
         &obj->debug_line,
         &obj->debug_ranges,
-        &obj->debug_str
+        &obj->debug_str_offsets,
+        &obj->debug_addr,
+        &obj->debug_rnglists,
+        &obj->debug_str,
+        &obj->debug_line_str
     };
     if (n < 0 || DWARF_SECTION_COUNT <= n) {
         abort();
@@ -194,12 +198,12 @@ struct debug_section_definition {
 static char binary_filename[PATH_MAX + 1];
 
 static unsigned long
-uleb128(char **p)
+uleb128(const char **p)
 {
     unsigned long r = 0;
     int s = 0;
     for (;;) {
-	unsigned char b = *(unsigned char *)(*p)++;
+	unsigned char b = (unsigned char)*(*p)++;
 	if (b < 0x80) {
 	    r += (unsigned long)b << s;
 	    break;
@@ -211,12 +215,12 @@ uleb128(char **p)
 }
 
 static long
-sleb128(char **p)
+sleb128(const char **p)
 {
     long r = 0;
     int s = 0;
     for (;;) {
-	unsigned char b = *(unsigned char *)(*p)++;
+	unsigned char b = (unsigned char)*(*p)++;
 	if (b < 0x80) {
 	    if (b & 0x40) {
 		r -= (0x80 - b) << s;
@@ -233,7 +237,7 @@ sleb128(char **p)
 }
 
 static const char *
-get_nth_dirname(unsigned long dir, char *p)
+get_nth_dirname(unsigned long dir, const char *p)
 {
     if (!dir--) {
 	return "";
@@ -250,39 +254,51 @@ get_nth_dirname(unsigned long dir, char *p)
     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 void
-fill_filename(int file, char *include_directories, 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)
 {
     int i;
-    char *p = filenames;
-    char *filename;
+    const char *p = filenames;
+    const char *filename;
     unsigned long dir;
-    for (i = 1; i <= file; i++) {
-	filename = p;
-	if (!*p) {
-	    /* Need to output binary file name? */
-	    kprintf("Unexpected file number %d in %s at %tx\n",
-		    file, binary_filename, filenames - obj->mapped);
-	    return;
-	}
-	while (*p) p++;
-	p++;
-	dir = uleb128(&p);
-	/* last modified. */
-	uleb128(&p);
-	/* size of the file. */
-	uleb128(&p);
-
-	if (i == file) {
-	    line->filename = filename;
-	    line->dirname = get_nth_dirname(dir, include_directories);
-	}
+    if (version >= 5) {
+        const char *path;
+        uint64_t directory_index = -1;
+        parse_ver5_debug_line_header(filenames, file, format, obj, &path, &directory_index);
+        line->filename = path;
+        parse_ver5_debug_line_header(include_directories, (int)directory_index, format, obj, &path, NULL);
+        line->dirname = path;
+    }
+    else {
+        for (i = 1; i <= file; i++) {
+            filename = p;
+            if (!*p) {
+                /* Need to output binary file name? */
+                kprintf("Unexpected file number %d in %s at %tx\n",
+                        file, binary_filename, filenames - obj->mapped);
+                return;
+            }
+            while (*p) p++;
+            p++;
+            dir = uleb128(&p);
+            /* last modified. */
+            uleb128(&p);
+            /* size of the file. */
+            uleb128(&p);
+
+            if (i == file) {
+                line->filename = filename;
+                line->dirname = get_nth_dirname(dir, include_directories);
+            }
+        }
     }
 }
 
 static void
 fill_line(int num_traces, void **traces, uintptr_t addr, int file, int line,
-	  char *include_directories, char *filenames,
+	  uint8_t format, uint16_t version, const char *include_directories, const char *filenames,
 	  obj_info_t *obj, line_info_t *lines, int offset)
 {
     int i;
@@ -292,7 +308,7 @@ fill_line(int num_traces, void **traces, uintptr_t addr, int file, int line,
 	/* We assume one line code doesn't result >100 bytes of native code.
        We may want more reliable way eventually... */
 	if (addr < a && a < addr + 100) {
-	    fill_filename(file, include_directories, filenames, &lines[i], obj);
+	    fill_filename(file, format, version, include_directories, filenames, &lines[i], obj);
 	    lines[i].line = line;
 	}
     }
@@ -317,7 +333,7 @@ struct LineNumberProgramHeader {
 };
 
 static int
-parse_debug_line_header(const char **pp, struct LineNumberProgramHeader *header)
+parse_debug_line_header(obj_info_t *obj, const char **pp, struct LineNumberProgramHeader *header)
 {
     const char *p = *pp;
     header->unit_length = *(uint32_t *)p;
@@ -334,7 +350,13 @@ parse_debug_line_header(const char **pp, struct LineNumberProgramHeader *header)
 
     header->version = *(uint16_t *)p;
     p += sizeof(uint16_t);
-    if (header->version > 4) return -1;
+    if (header->version > 5) return -1;
+
+    if (header->version >= 5) {
+        /* address_size = *(uint8_t *)p++; */
+        /* segment_selector_size = *(uint8_t *)p++; */
+        p += 2;
+    }
 
     header->header_length = header->format == 4 ? *(uint32_t *)p : *(uint64_t *)p;
     p += header->format;
@@ -355,20 +377,27 @@ parse_debug_line_header(const char **pp, struct LineNumberProgramHeader *header)
     /* header->standard_opcode_lengths = (uint8_t *)p - 1; */
     p += header->opcode_base - 1;
 
-    header->include_directories = p;
+    if (header->version >= 5) {
+        header->include_directories = p;
+        p = parse_ver5_debug_line_header(p, -1, header->format, obj, NULL, NULL);
+        header->filenames = p;
+    }
+    else {
+        header->include_directories = p;
 
-    /* temporary measure for compress-debug-sections */
-    if (p >= header->cu_end) return -1;
+        /* temporary measure for compress-debug-sections */
+        if (p >= header->cu_end) return -1;
 
-    /* skip include directories */
-    while (*p) {
-	p = memchr(p, '\0', header->cu_end - p);
-	if (!p) return -1;
-	p++;
-    }
-    p++;
+        /* skip include directories */
+        while (*p) {
+            p = memchr(p, '\0', header->cu_end - p);
+            if (!p) return -1;
+            p++;
+        }
+        p++;
 
-    header->filenames = p;
+        header->filenames = p;
+    }
 
     *pp = header->cu_start;
 
@@ -376,7 +405,7 @@ parse_debug_line_header(const char **pp, struct LineNumberProgramHeader *header)
 }
 
 static int
-parse_debug_line_cu(int num_traces, void **traces, char **debug_line,
+parse_debug_line_cu(int num_traces, void **traces, const char **debug_line,
 		obj_info_t *obj, line_info_t *lines, int offset)
 {
     const char *p = (const char *)*debug_line;
@@ -394,15 +423,17 @@ parse_debug_line_cu(int num_traces, void **traces, char **debug_line,
     /* int epilogue_begin = 0; */
     /* unsigned int isa = 0; */
 
-    if (parse_debug_line_header(&p, &header))
+    if (parse_debug_line_header(obj, &p, &header))
         return -1;
     is_stmt = header.default_is_stmt;
 
 #define FILL_LINE()						    \
     do {							    \
 	fill_line(num_traces, traces, addr, file, line,		    \
-                  (char *)header.include_directories,               \
-                  (char *)header.filenames,                         \
+                  header.format,                                    \
+                  header.version,                                   \
+                  header.include_directories,                       \
+                  header.filenames,                                 \
 		  obj, lines, offset);				    \
 	/*basic_block = prologue_end = epilogue_begin = 0;*/	    \
     } while (0)
@@ -415,19 +446,19 @@ parse_debug_line_cu(int num_traces, void **traces, char **debug_line,
 	    FILL_LINE();
 	    break;
 	case DW_LNS_advance_pc:
-	    a = uleb128((char **)&p);
+	    a = uleb128(&p) * header.minimum_instruction_length;
 	    addr += a;
 	    break;
 	case DW_LNS_advance_line: {
-	    long a = sleb128((char **)&p);
+	    long a = sleb128(&p);
 	    line += a;
 	    break;
 	}
 	case DW_LNS_set_file:
-	    file = (unsigned int)uleb128((char **)&p);
+	    file = (unsigned int)uleb128(&p);
 	    break;
 	case DW_LNS_set_column:
-	    /*column = (unsigned int)*/(void)uleb128((char **)&p);
+	    /*column = (unsigned int)*/(void)uleb128(&p);
 	    break;
 	case DW_LNS_negate_stmt:
 	    is_stmt = !is_stmt;
@@ -441,7 +472,8 @@ parse_debug_line_cu(int num_traces, void **traces, char **debug_line,
 	    addr += a;
 	    break;
 	case DW_LNS_fixed_advance_pc:
-	    a = *(unsigned char *)p++;
+	    a = *(uint16_t *)p;
+	    p += sizeof(uint16_t);
 	    addr += a;
 	    break;
 	case DW_LNS_set_prologue_end:
@@ -451,10 +483,10 @@ parse_debug_line_cu(int num_traces, void **traces, char **debug_line,
 	    /* epilogue_begin = 1; */
 	    break;
 	case DW_LNS_set_isa:
-	    /* isa = (unsigned int)*/(void)uleb128((char **)&p);
+	    /* isa = (unsigned int)*/(void)uleb128(&p);
 	    break;
 	case 0:
-	    a = *(unsigned char *)p++;
+	    a = uleb128(&p);
 	    op = *p++;
 	    switch (op) {
 	    case DW_LNE_end_sequence:
@@ -478,7 +510,7 @@ parse_debug_line_cu(int num_traces, void **traces, char **debug_line,
 		break;
 	    case DW_LNE_set_discriminator:
 		/* TODO:currently ignore */
-		uleb128((char **)&p);
+		uleb128(&p);
 		break;
 	    default:
 		kprintf("Unknown extended opcode: %d in %s\n",
@@ -501,10 +533,10 @@ parse_debug_line_cu(int num_traces, void **traces, char **debug_line,
 
 static int
 parse_debug_line(int num_traces, void **traces,
-		 char *debug_line, unsigned long size,
+		 const char *debug_line, unsigned long size,
 		 obj_info_t *obj, line_info_t *lines, int offset)
 {
-    char *debug_line_end = debug_line + size;
+    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;
@@ -530,13 +562,25 @@ append_obj(obj_info_t **objp)
 }
 
 #ifdef USE_ELF
+/* Ideally we should check 4 paths to follow gnu_debuglink:
+ *
+ *   - /usr/lib/debug/.build-id/ab/cdef1234.debug
+ *   - /usr/bin/ruby.debug
+ *   - /usr/bin/.debug/ruby.debug
+ *   - /usr/lib/debug/usr/bin/ruby.debug.
+ *
+ * but we handle only two cases for now as the two formats are
+ * used by some linux distributions.
+ *
+ * See GDB's info for detail.
+ * https://sourceware.org/gdb/onlinedocs/gdb/Separate-Debug-Files.html
+ */
+
+// check the path pattern of "/usr/lib/debug/usr/bin/ruby.debug"
 static void
 follow_debuglink(const char *debuglink, int num_traces, void **traces,
 		 obj_info_t **objp, line_info_t *lines, int offset)
 {
-    /* Ideally we should check 4 paths to follow gnu_debuglink,
-       but we handle only one case for now as this format is used
-       by some linux distributions. See GDB's info for detail. */
     static const char global_debug_dir[] = "/usr/lib/debug";
     const size_t global_debug_dir_len = sizeof(global_debug_dir) - 1;
     char *p;
@@ -563,6 +607,37 @@ follow_debuglink(const char *debuglink, int num_traces, void **traces,
     o2->path = o1->path;
     fill_lines(num_traces, traces, 0, objp, lines, offset);
 }
+
+// check the path pattern of "/usr/lib/debug/.build-id/ab/cdef1234.debug"
+static void
+follow_debuglink_build_id(const char *build_id, size_t build_id_size, int num_traces, void **traces,
+                          obj_info_t **objp, line_info_t *lines, int offset)
+{
+    static const char global_debug_dir[] = "/usr/lib/debug/.build-id/";
+    const size_t global_debug_dir_len = sizeof(global_debug_dir) - 1;
+    char *p;
+    obj_info_t *o1 = *objp, *o2;
+    size_t i;
+
+    if (PATH_MAX < global_debug_dir_len + 1 + build_id_size * 2 + 6) return;
+
+    memcpy(binary_filename, global_debug_dir, global_debug_dir_len);
+    p = binary_filename + global_debug_dir_len;
+    for (i = 0; i < build_id_size; i++) {
+        static const char tbl[] = "0123456789abcdef";
+        unsigned char n = build_id[i];
+        *p++ = tbl[n / 16];
+        *p++ = tbl[n % 16];
+        if (i == 0) *p++ = '/';
+    }
+    strcpy(p, ".debug");
+
+    append_obj(objp);
+    o2 = *objp;
+    o2->base_addr = o1->base_addr;
+    o2->path = o1->path;
+    fill_lines(num_traces, traces, 0, objp, lines, offset);
+}
 #endif
 
 enum
@@ -768,32 +843,51 @@ enum
     DW_FORM_addrx4 = 0x2c
 };
 
+/* Range list entry encodings */
+enum {
+    DW_RLE_end_of_list = 0x00,
+    DW_RLE_base_addressx = 0x01,
+    DW_RLE_startx_endx = 0x02,
+    DW_RLE_startx_length = 0x03,
+    DW_RLE_offset_pair = 0x04,
+    DW_RLE_base_address = 0x05,
+    DW_RLE_start_end = 0x06,
+    DW_RLE_start_length = 0x07
+};
+
 enum {
     VAL_none = 0,
     VAL_cstr = 1,
     VAL_data = 2,
     VAL_uint = 3,
-    VAL_int = 4
+    VAL_int = 4,
+    VAL_addr = 5
 };
 
 # define ABBREV_TABLE_SIZE 256
 typedef struct {
     obj_info_t *obj;
-    char *file;
-    char *current_cu;
+    const char *file;
+    uint8_t current_version;
+    const char *current_cu;
     uint64_t current_low_pc;
-    char *debug_line_cu_end;
-    char *debug_line_files;
-    char *debug_line_directories;
-    char *p;
-    char *cu_end;
-    char *pend;
-    char *q0;
-    char *q;
+    uint64_t current_str_offsets_base;
+    uint64_t current_addr_base;
+    uint64_t current_rnglists_base;
+    const char *debug_line_cu_end;
+    uint8_t debug_line_format;
+    uint16_t debug_line_version;
+    const char *debug_line_files;
+    const char *debug_line_directories;
+    const char *p;
+    const char *cu_end;
+    const char *pend;
+    const char *q0;
+    const char *q;
     int format; // 4 or 8
     uint8_t address_size;
     int level;
-    char *abbrev_table[ABBREV_TABLE_SIZE];
+    const char *abbrev_table[ABBREV_TABLE_SIZE];
 } DebugInfoReader;
 
 typedef struct {
@@ -804,9 +898,10 @@ typedef struct {
 
 typedef struct {
     union {
-        char *ptr;
+        const char *ptr;
         uint64_t uint64;
         int64_t int64;
+        uint64_t addr_idx;
     } as;
     uint64_t off;
     uint64_t at;
@@ -815,8 +910,11 @@ typedef struct {
     int type;
 } DebugInfoValue;
 
-/* TODO: Big Endian */
+#if defined(WORDS_BIGENDIAN)
+#define MERGE_2INTS(a,b,sz) (((uint64_t)(a)<<sz)|(b))
+#else
 #define MERGE_2INTS(a,b,sz) (((uint64_t)(b)<<sz)|(a))
+#endif
 
 static uint16_t
 get_uint16(const uint8_t *p)
@@ -837,39 +935,39 @@ get_uint64(const uint8_t *p)
 }
 
 static uint8_t
-read_uint8(char **ptr)
+read_uint8(const char **ptr)
 {
-    const unsigned char *p = (const unsigned char *)*ptr;
-    *ptr = (char *)(p + 1);
-    return *p;
+    const char *p = *ptr;
+    *ptr = (p + 1);
+    return (uint8_t)*p;
 }
 
 static uint16_t
-read_uint16(char **ptr)
+read_uint16(const char **ptr)
 {
-    const unsigned char *p = (const unsigned char *)*ptr;
-    *ptr = (char *)(p + 2);
-    return get_uint16(p);
+    const char *p = *ptr;
+    *ptr = (p + 2);
+    return get_uint16((const uint8_t *)p);
 }
 
 static uint32_t
-read_uint24(char **ptr)
+read_uint24(const char **ptr)
 {
-    const unsigned char *p = (const unsigned char *)*ptr;
-    *ptr = (char *)(p + 3);
-    return (*p << 16) | get_uint16(p+1);
+    const char *p = *ptr;
+    *ptr = (p + 3);
+    return ((uint8_t)*p << 16) | get_uint16((const uint8_t *)p+1);
 }
 
 static uint32_t
-read_uint32(char **ptr)
+read_uint32(const char **ptr)
 {
-    const unsigned char *p = (const unsigned char *)*ptr;
-    *ptr = (char *)(p + 4);
-    return get_uint32(p);
+    const char *p = *ptr;
+    *ptr = (p + 4);
+    return get_uint32((const uint8_t *)p);
 }
 
 static uint64_t
-read_uint64(char **ptr)
+read_uint64(const char **ptr)
 {
     const unsigned char *p = (const unsigned char *)*ptr;
     *ptr = (char *)(p + 8);
@@ -877,7 +975,7 @@ read_uint64(char **ptr)
 }
 
 static uintptr_t
-read_uintptr(char **ptr)
+read_uintptr(const char **ptr)
 {
     const unsigned char *p = (const unsigned char *)*ptr;
     *ptr = (char *)(p + SIZEOF_VOIDP);
@@ -918,13 +1016,34 @@ debug_info_reader_init(DebugInfoReader *reader, obj_info_t *obj)
     reader->p = obj->debug_info.ptr;
     reader->pend = obj->debug_info.ptr + obj->debug_info.size;
     reader->debug_line_cu_end = obj->debug_line.ptr;
+    reader->current_low_pc = 0;
+    reader->current_str_offsets_base = 0;
+    reader->current_addr_base = 0;
+    reader->current_rnglists_base = 0;
+}
+
+static void
+di_skip_die_attributes(const char **p)
+{
+    for (;;) {
+        uint64_t at = uleb128(p);
+        uint64_t form = uleb128(p);
+        if (!at && !form) break;
+        switch (form) {
+          default:
+            break;
+          case DW_FORM_implicit_const:
+            sleb128(p);
+            break;
+        }
+    }
 }
 
 static void
 di_read_debug_abbrev_cu(DebugInfoReader *reader)
 {
     uint64_t prev = 0;
-    char *p = reader->q0;
+    const char *p = reader->q0;
     for (;;) {
         uint64_t abbrev_number = uleb128(&p);
         if (abbrev_number <= prev) break;
@@ -934,12 +1053,7 @@ di_read_debug_abbrev_cu(DebugInfoReader *reader)
         prev = abbrev_number;
         uleb128(&p); /* tag */
         p++; /* has_children */
-        /* skip content */
-        for (;;) {
-            uint64_t at = uleb128(&p);
-            uint64_t form = uleb128(&p);
-            if (!at && !form) break;
-        }
+        di_skip_die_attributes(&p);
     }
 }
 
@@ -950,10 +1064,12 @@ di_read_debug_line_cu(DebugInfoReader *reader)
     struct LineNumberProgramHeader header;
 
     p = (const char *)reader->debug_line_cu_end;
-    if (parse_debug_line_header(&p, &header))
+    if (parse_debug_line_header(reader->obj, &p, &header))
         return -1;
 
     reader->debug_line_cu_end = (char *)header.cu_end;
+    reader->debug_line_format = header.format;
+    reader->debug_line_version = header.version;
     reader->debug_line_directories = (char *)header.include_directories;
     reader->debug_line_files = (char *)header.filenames;
 
@@ -961,6 +1077,13 @@ di_read_debug_line_cu(DebugInfoReader *reader)
 }
 
 static void
+set_addr_idx_value(DebugInfoValue *v, uint64_t n)
+{
+    v->as.addr_idx = n;
+    v->type = VAL_addr;
+}
+
+static void
 set_uint_value(DebugInfoValue *v, uint64_t n)
 {
     v->as.uint64 = n;
@@ -975,7 +1098,7 @@ set_int_value(DebugInfoValue *v, int64_t n)
 }
 
 static void
-set_cstr_value(DebugInfoValue *v, char *s)
+set_cstr_value(DebugInfoValue *v, const char *s)
 {
     v->as.ptr = s;
     v->off = 0;
@@ -983,7 +1106,7 @@ set_cstr_value(DebugInfoValue *v, char *s)
 }
 
 static void
-set_cstrp_value(DebugInfoValue *v, char *s, uint64_t off)
+set_cstrp_value(DebugInfoValue *v, const char *s, uint64_t off)
 {
     v->as.ptr = s;
     v->off = off;
@@ -991,7 +1114,7 @@ set_cstrp_value(DebugInfoValue *v, char *s, uint64_t off)
 }
 
 static void
-set_data_value(DebugInfoValue *v, char *s)
+set_data_value(DebugInfoValue *v, const char *s)
 {
     v->as.ptr = s;
     v->type = VAL_data;
@@ -1007,19 +1130,39 @@ get_cstr_value(DebugInfoValue *v)
     }
 }
 
+static const char *
+resolve_strx(DebugInfoReader *reader, uint64_t idx)
+{
+    const char *p = reader->obj->debug_str_offsets.ptr + reader->current_str_offsets_base;
+    uint64_t off;
+    if (reader->format == 4) {
+        off = ((uint32_t *)p)[idx];
+    }
+    else {
+        off = ((uint64_t *)p)[idx];
+    }
+    return reader->obj->debug_str.ptr + off;
+}
+
+static void
+debug_info_reader_read_addr_value(DebugInfoReader *reader, DebugInfoValue *v)
+{
+    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();
+    }
+}
+
 static void
 debug_info_reader_read_value(DebugInfoReader *reader, uint64_t form, DebugInfoValue *v)
 {
     switch (form) {
       case DW_FORM_addr:
-        if (reader->address_size == 4) {
-            set_uint_value(v, read_uint32(&reader->p));
-        } else if (reader->address_size == 8) {
-            set_uint_value(v, read_uint64(&reader->p));
-        } else {
-            fprintf(stderr,"unknown address_size:%d", reader->address_size);
-            abort();
-        }
+        debug_info_reader_read_addr_value(reader, v);
         break;
       case DW_FORM_block2:
         v->size = read_uint16(&reader->p);
@@ -1071,13 +1214,19 @@ 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->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));
+        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);
         } else {
-            fprintf(stderr,"unknown address_size:%d", reader->address_size);
-            abort();
+            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));
+            } else {
+                fprintf(stderr,"unknown format:%d", reader->format);
+                abort();
+            }
         }
         break;
       case DW_FORM_ref1:
@@ -1119,11 +1268,10 @@ debug_info_reader_read_value(DebugInfoReader *reader, uint64_t form, DebugInfoVa
         set_uint_value(v, 1);
         break;
       case DW_FORM_strx:
-        set_uint_value(v, uleb128(&reader->p));
+        set_cstr_value(v, resolve_strx(reader, uleb128(&reader->p)));
         break;
       case DW_FORM_addrx:
-        /* TODO: read .debug_addr */
-        set_uint_value(v, uleb128(&reader->p));
+        set_addr_idx_value(v, uleb128(&reader->p));
         break;
       case DW_FORM_ref_sup4:
         set_uint_value(v, read_uint32(&reader->p));
@@ -1138,8 +1286,7 @@ debug_info_reader_read_value(DebugInfoReader *reader, uint64_t form, DebugInfoVa
         reader->p += v->size;
         break;
       case DW_FORM_line_strp:
-        set_uint_value(v, read_uint(reader));
-        /* *p = reader->file + reader->line->sh_offset + ret; */
+        set_cstrp_value(v, reader->obj->debug_line_str.ptr, read_uint(reader));
         break;
       case DW_FORM_ref_sig8:
         set_uint_value(v, read_uint64(&reader->p));
@@ -1157,28 +1304,28 @@ debug_info_reader_read_value(DebugInfoReader *reader, uint64_t form, DebugInfoVa
         set_uint_value(v, read_uint64(&reader->p));
         break;
       case DW_FORM_strx1:
-        set_uint_value(v, read_uint8(&reader->p));
+        set_cstr_value(v, resolve_strx(reader, read_uint8(&reader->p)));
         break;
       case DW_FORM_strx2:
-        set_uint_value(v, read_uint16(&reader->p));
+        set_cstr_value(v, resolve_strx(reader, read_uint16(&reader->p)));
         break;
       case DW_FORM_strx3:
-        set_uint_value(v, read_uint24(&reader->p));
+        set_cstr_value(v, resolve_strx(reader, read_uint24(&reader->p)));
         break;
       case DW_FORM_strx4:
-        set_uint_value(v, read_uint32(&reader->p));
+        set_cstr_value(v, resolve_strx(reader, read_uint32(&reader->p)));
         break;
       case DW_FORM_addrx1:
-        set_uint_value(v, read_uint8(&reader->p));
+        set_addr_idx_value(v, read_uint8(&reader->p));
         break;
       case DW_FORM_addrx2:
-        set_uint_value(v, read_uint16(&reader->p));
+        set_addr_idx_value(v, read_uint16(&reader->p));
         break;
       case DW_FORM_addrx3:
-        set_uint_value(v, read_uint24(&reader->p));
+        set_addr_idx_value(v, read_uint24(&reader->p));
         break;
       case DW_FORM_addrx4:
-        set_uint_value(v, read_uint32(&reader->p));
+        set_addr_idx_value(v, read_uint32(&reader->p));
         break;
       case 0:
         goto fail;
@@ -1192,10 +1339,10 @@ debug_info_reader_read_value(DebugInfoReader *reader, uint64_t form, DebugInfoVa
 }
 
 /* find abbrev in current compilation unit */
-static char *
+static const char *
 di_find_abbrev(DebugInfoReader *reader, uint64_t abbrev_number)
 {
-    char *p;
+    const char *p;
     if (abbrev_number < ABBREV_TABLE_SIZE) {
         return reader->abbrev_table[abbrev_number];
     }
@@ -1203,12 +1350,7 @@ di_find_abbrev(DebugInfoReader *reader, uint64_t abbrev_number)
     /* skip 255th record */
     uleb128(&p); /* tag */
     p++; /* has_children */
-    /* skip content */
-    for (;;) {
-        uint64_t at = uleb128(&p);
-        uint64_t form = uleb128(&p);
-        if (!at && !form) break;
-    }
+    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);
@@ -1216,12 +1358,7 @@ di_find_abbrev(DebugInfoReader *reader, uint64_t abbrev_number)
         }
         uleb128(&p); /* tag */
         p++; /* has_children */
-        /* skip content */
-        for (;;) {
-            uint64_t at = uleb128(&p);
-            uint64_t form = uleb128(&p);
-            if (!at && !form) break;
-        }
+        di_skip_die_attributes(&p);
     }
     return p;
 }
@@ -1235,7 +1372,7 @@ hexdump0(const unsigned char *p, size_t n)
     for (i=0; i < n; i++){
         switch (i & 15) {
           case 0:
-            fprintf(stderr, "%02zd: %02X ", i/16, p[i]);
+            fprintf(stderr, "%02" PRIdSIZE ": %02X ", i/16, p[i]);
             break;
           case 15:
             fprintf(stderr, "%02X\n", p[i]);
@@ -1256,16 +1393,16 @@ div_inspect(DebugInfoValue *v)
 {
     switch (v->type) {
       case VAL_uint:
-        fprintf(stderr,"%d: type:%d size:%zx v:%lx\n",__LINE__,v->type,v->size,v->as.uint64);
+        fprintf(stderr,"%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:%zx v:%ld\n",__LINE__,v->type,v->size,(int64_t)v->as.uint64);
+        fprintf(stderr,"%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:%zx v:'%s'\n",__LINE__,v->type,v->size,v->as.ptr);
+        fprintf(stderr,"%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:%zx v:\n",__LINE__,v->type,v->size);
+        fprintf(stderr,"%d: type:%d size:%" PRIxSIZE " v:\n",__LINE__,v->type,v->size);
         hexdump(v->as.ptr, 16);
         break;
     }
@@ -1316,6 +1453,76 @@ di_skip_records(DebugInfoReader *reader)
     }
 }
 
+typedef struct addr_header {
+    const char *ptr;
+    uint64_t unit_length;
+    uint8_t format;
+    uint8_t address_size;
+    /* uint8_t segment_selector_size; */
+} addr_header_t;
+
+static void
+addr_header_init(obj_info_t *obj, addr_header_t *header) {
+    const char *p = obj->debug_addr.ptr;
+
+    header->ptr = p;
+
+    if (!p) return;
+
+    header->unit_length = *(uint32_t *)p;
+    p += sizeof(uint32_t);
+
+    header->format = 4;
+    if (header->unit_length == 0xffffffff) {
+        header->unit_length = *(uint64_t *)p;
+        p += sizeof(uint64_t);
+        header->format = 8;
+    }
+
+    p += 2; /* version */
+    header->address_size = *p++;
+    p++; /* segment_selector_size */
+}
+
+static uint64_t
+read_addr(addr_header_t *header, uint64_t addr_base, uint64_t idx) {
+    if (header->address_size == 4) {
+        return ((uint32_t*)(header->ptr + addr_base))[idx];
+    }
+    else {
+        return ((uint64_t*)(header->ptr + addr_base))[idx];
+    }
+}
+
+typedef struct rnglists_header {
+    uint64_t unit_length;
+    uint8_t format;
+    uint8_t address_size;
+    uint32_t offset_entry_count;
+} rnglists_header_t;
+
+static void
+rnglists_header_init(obj_info_t *obj, rnglists_header_t *header) {
+    const char *p = obj->debug_rnglists.ptr;
+
+    if (!p) return;
+
+    header->unit_length = *(uint32_t *)p;
+    p += sizeof(uint32_t);
+
+    header->format = 4;
+    if (header->unit_length == 0xffffffff) {
+        header->unit_length = *(uint64_t *)p;
+        p += sizeof(uint64_t);
+        header->format = 8;
+    }
+
+    p += 2; /* version */
+    header->address_size = *p++;
+    p++; /* segment_selector_size */
+    header->offset_entry_count = *(uint32_t *)p;
+}
+
 typedef struct {
     uint64_t low_pc;
     uint64_t high_pc;
@@ -1326,31 +1533,53 @@ typedef struct {
 } ranges_t;
 
 static void
-ranges_set(ranges_t *ptr, DebugInfoValue *v)
+ranges_set(ranges_t *ptr, DebugInfoValue *v, addr_header_t *addr_header, uint64_t addr_base)
 {
+    uint64_t n = 0;
+    if (v->type == VAL_uint) {
+        n = v->as.uint64;
+    }
+    else if (v->type == VAL_addr) {
+        n = read_addr(addr_header, addr_base, v->as.addr_idx);
+    }
     switch (v->at) {
       case DW_AT_low_pc:
-        ptr->low_pc = v->as.uint64;
+        ptr->low_pc = n;
         ptr->low_pc_set = true;
         break;
       case DW_AT_high_pc:
         if (v->form == DW_FORM_addr) {
-            ptr->high_pc = v->as.uint64;
+            ptr->high_pc = n;
         }
         else {
-            ptr->high_pc = ptr->low_pc + v->as.uint64;
+            ptr->high_pc = ptr->low_pc + n;
         }
         ptr->high_pc_set = true;
         break;
       case DW_AT_ranges:
-        ptr->ranges = v->as.uint64;
+        ptr->ranges = n;
         ptr->ranges_set = true;
         break;
     }
 }
 
+static uint64_t
+read_dw_form_addr(DebugInfoReader *reader, const char **ptr)
+{
+    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();
+    }
+}
+
 static uintptr_t
-ranges_include(DebugInfoReader *reader, ranges_t *ptr, uint64_t addr)
+ranges_include(DebugInfoReader *reader, ranges_t *ptr, uint64_t addr, rnglists_header_t *rnglists_header)
 {
     if (ptr->high_pc_set) {
         if (ptr->ranges_set || !ptr->low_pc_set) {
@@ -1362,8 +1591,66 @@ ranges_include(DebugInfoReader *reader, ranges_t *ptr, uint64_t addr)
     }
     else if (ptr->ranges_set) {
         /* TODO: support base address selection entry */
-        char *p = reader->obj->debug_ranges.ptr + ptr->ranges;
+        const char *p;
         uint64_t base = ptr->low_pc_set ? ptr->low_pc : reader->current_low_pc;
+        bool base_valid = true;
+        if (reader->current_version >= 5) {
+            if (rnglists_header->offset_entry_count == 0) {
+                // DW_FORM_sec_offset
+                p = reader->obj->debug_rnglists.ptr + ptr->ranges + reader->current_rnglists_base;
+            }
+            else {
+                // DW_FORM_rnglistx
+                const char *offset_array = reader->obj->debug_rnglists.ptr + reader->current_rnglists_base;
+                if (rnglists_header->format == 4) {
+                    p = offset_array + ((uint32_t *)offset_array)[ptr->ranges];
+                }
+                else {
+                    p = offset_array + ((uint64_t *)offset_array)[ptr->ranges];
+                }
+            }
+            for (;;) {
+                uint8_t rle = read_uint8(&p);
+                uintptr_t from = 0, to = 0;
+                if (rle == DW_RLE_end_of_list) break;
+                switch (rle) {
+                  case DW_RLE_base_addressx:
+                    uleb128(&p);
+                    base_valid = false; /* not supported yet */
+                    break;
+                  case DW_RLE_startx_endx:
+                    uleb128(&p);
+                    uleb128(&p);
+                    break;
+                  case DW_RLE_startx_length:
+                    uleb128(&p);
+                    uleb128(&p);
+                    break;
+                  case DW_RLE_offset_pair:
+                    if (!base_valid) break;
+                    from = (uintptr_t)base + uleb128(&p);
+                    to = (uintptr_t)base + uleb128(&p);
+                    break;
+                  case DW_RLE_base_address:
+                    base = read_dw_form_addr(reader, &p);
+                    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);
+                    break;
+                  case DW_RLE_start_length:
+                    from = (uintptr_t)read_dw_form_addr(reader, &p);
+                    to = from + uleb128(&p);
+                    break;
+                }
+                if (from <= addr && addr < to) {
+                    return from;
+                }
+            }
+            return false;
+        }
+        p = reader->obj->debug_ranges.ptr + ptr->ranges;
         for (;;) {
             uintptr_t from = read_uintptr(&p);
             uintptr_t to = read_uintptr(&p);
@@ -1373,7 +1660,7 @@ ranges_include(DebugInfoReader *reader, ranges_t *ptr, uint64_t addr)
                 base = to;
             }
             else if (base + from <= addr && addr < base + to) {
-                return from;
+                return (uintptr_t)base + from;
             }
         }
     }
@@ -1431,6 +1718,7 @@ di_read_cu(DebugInfoReader *reader)
     }
     reader->cu_end = reader->p + unit_length;
     version = read_uint16(&reader->p);
+    reader->current_version = version;
     if (version > 5) {
         return -1;
     }
@@ -1463,30 +1751,76 @@ di_read_cu(DebugInfoReader *reader)
             break;
         }
 
+        reader->current_str_offsets_base = 0;
+        reader->current_addr_base = 0;
+        reader->current_rnglists_base = 0;
+
+        DebugInfoValue low_pc = {{}};
         /* enumerate abbrev */
         for (;;) {
             DebugInfoValue v = {{}};
             if (!di_read_record(reader, &v)) break;
             switch (v.at) {
               case DW_AT_low_pc:
-                reader->current_low_pc = v.as.uint64;
+                // clang may output DW_AT_addr_base after DW_AT_low_pc.
+                // We need to resolve the DW_FORM_addr* after DW_AT_addr_base is parsed.
+                low_pc = v;
+                break;
+              case DW_AT_str_offsets_base:
+                reader->current_str_offsets_base = v.as.uint64;
+                break;
+              case DW_AT_addr_base:
+                reader->current_addr_base = v.as.uint64;
+                break;
+              case DW_AT_rnglists_base:
+                reader->current_rnglists_base = v.as.uint64;
                 break;
             }
         }
+        // Resolve the DW_FORM_addr of DW_AT_low_pc
+        switch (low_pc.type) {
+            case VAL_uint:
+                reader->current_low_pc = low_pc.as.uint64;
+                break;
+            case VAL_addr:
+                {
+                    addr_header_t header;
+                    addr_header_init(reader->obj, &header);
+                    reader->current_low_pc = read_addr(&header, reader->current_addr_base, low_pc.as.addr_idx);
+                }
+                break;
+        }
     } while (0);
 #endif
     return 0;
 }
 
 static void
-read_abstract_origin(DebugInfoReader *reader, uint64_t abstract_origin, line_info_t *line)
+read_abstract_origin(DebugInfoReader *reader, uint64_t form, uint64_t abstract_origin, line_info_t *line)
 {
-    char *p = reader->p;
-    char *q = reader->q;
+    const char *p = reader->p;
+    const char *q = reader->q;
     int level = reader->level;
     DIE die;
 
-    reader->p = reader->current_cu + abstract_origin;
+    switch (form) {
+      case DW_FORM_ref1:
+      case DW_FORM_ref2:
+      case DW_FORM_ref4:
+      case DW_FORM_ref8:
+      case DW_FORM_ref_udata:
+        reader->p = reader->current_cu + abstract_origin;
+        break;
+      case DW_FORM_ref_addr:
+        goto finish; /* not supported yet */
+      case DW_FORM_ref_sig8:
+        goto finish; /* not supported yet */
+      case DW_FORM_ref_sup4:
+      case DW_FORM_ref_sup8:
+        goto finish; /* not supported yet */
+      default:
+        goto finish;
+    }
     if (!di_read_die(reader, &die)) goto finish;
 
     /* enumerate abbrev */
@@ -1509,6 +1843,13 @@ read_abstract_origin(DebugInfoReader *reader, uint64_t abstract_origin, line_inf
 static void
 debug_info_read(DebugInfoReader *reader, int num_traces, void **traces,
          line_info_t *lines, int offset) {
+
+    addr_header_t addr_header = {};
+    addr_header_init(reader->obj, &addr_header);
+
+    rnglists_header_t rnglists_header = {};
+    rnglists_header_init(reader->obj, &rnglists_header);
+
     while (reader->p < reader->cu_end) {
         DIE die;
         ranges_t ranges = {};
@@ -1535,7 +1876,7 @@ debug_info_read(DebugInfoReader *reader, int num_traces, void **traces,
                 line.sname = get_cstr_value(&v);
                 break;
               case DW_AT_call_file:
-                fill_filename((int)v.as.uint64, reader->debug_line_directories, reader->debug_line_files, &line, reader->obj);
+                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);
                 break;
               case DW_AT_call_line:
                 line.line = (int)v.as.uint64;
@@ -1543,7 +1884,7 @@ debug_info_read(DebugInfoReader *reader, int num_traces, void **traces,
               case DW_AT_low_pc:
               case DW_AT_high_pc:
               case DW_AT_ranges:
-                ranges_set(&ranges, &v);
+                ranges_set(&ranges, &v, &addr_header, reader->current_addr_base);
                 break;
               case DW_AT_declaration:
                 goto skip_die;
@@ -1551,7 +1892,7 @@ 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.as.uint64, &line);
+                read_abstract_origin(reader, v.form, v.as.uint64, &line);
                 break; /* goto skip_die; */
             }
         }
@@ -1560,9 +1901,9 @@ debug_info_read(DebugInfoReader *reader, int num_traces, void **traces,
         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);
+            uintptr_t saddr = ranges_include(reader, &ranges, offset, &rnglists_header);
             if (saddr) {
-                /* fprintf(stderr, "%d:%tx: %d %lx->%lx %x %s: %s/%s %d %s %s %s\n",__LINE__,die.pos, i,addr,offset, die.tag,line.sname,line.dirname,line.filename,line.line,reader->obj->path,line.sname,lines[i].sname); */
+                /* 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); */
                 if (lines[i].sname) {
                     line_info_t *lp = malloc(sizeof(line_info_t));
                     memcpy(lp, &lines[i], sizeof(line_info_t));
@@ -1581,10 +1922,59 @@ debug_info_read(DebugInfoReader *reader, int num_traces, void **traces,
     }
 }
 
+// This function parses the following attributes of Line Number Program Header in DWARF 5:
+//
+// * directory_entry_format_count
+// * directory_entry_format
+// * directories_count
+// * directories
+//
+// or
+//
+// * file_name_entry_format_count
+// * file_name_entry_format
+// * file_names_count
+// * file_names
+//
+// 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) {
+    int i, j;
+    int entry_format_count = *(uint8_t *)p++;
+    const char *entry_format = p;
+
+    /* skip the part of entry_format */
+    for (i = 0; i < entry_format_count * 2; i++) uleb128(&p);
+
+    int entry_count = (int)uleb128(&p);
+
+    DebugInfoReader reader;
+    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 = {{}};
+            unsigned long dw_lnct = uleb128(&format);
+            unsigned long dw_form = uleb128(&format);
+            debug_info_reader_read_value(&reader, dw_form, &v);
+            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)
+                *out_directory_index = v.as.uint64;
+        }
+        if (j == idx) return 0;
+    }
+
+    return reader.p;
+}
+
 #ifdef USE_ELF
 static unsigned long
 uncompress_debug_section(ElfW(Shdr) *shdr, char *file, char **ptr)
 {
+    *ptr = NULL;
 #ifdef SUPPORT_COMPRESSED_DEBUG_LINE
     ElfW(Chdr) *chdr = (ElfW(Chdr) *)(file + shdr->sh_offset);
     unsigned long destsize = chdr->ch_size;
@@ -1605,6 +1995,7 @@ uncompress_debug_section(ElfW(Shdr) *shdr, char *file, char **ptr)
 
 fail:
     free(*ptr);
+    *ptr = NULL;
 #endif
     return 0;
 }
@@ -1619,6 +2010,7 @@ fill_lines(int num_traces, void **traces, int check_debuglink,
     ElfW(Ehdr) *ehdr;
     ElfW(Shdr) *shdr, *shstr_shdr;
     ElfW(Shdr) *gnu_debuglink_shdr = NULL;
+    ElfW(Shdr) *note_gnu_build_id = NULL;
     int fd;
     off_t filesize;
     char *file;
@@ -1691,6 +2083,11 @@ fill_lines(int num_traces, void **traces, int check_debuglink,
 	    /* 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;
@@ -1701,7 +2098,11 @@ fill_lines(int num_traces, void **traces, int check_debuglink,
                     ".debug_info",
                     ".debug_line",
                     ".debug_ranges",
-                    ".debug_str"
+                    ".debug_str_offsets",
+                    ".debug_addr",
+                    ".debug_rnglists",
+                    ".debug_str",
+                    ".debug_line_str"
                 };
 
                 for (j=0; j < DWARF_SECTION_COUNT; j++) {
@@ -1806,6 +2207,13 @@ use_symtab:
 			     num_traces, traces,
 			     objp, lines, offset);
 	}
+        if (note_gnu_build_id && check_debuglink) {
+            ElfW(Nhdr) *nhdr = (ElfW(Nhdr)*) (file + note_gnu_build_id->sh_offset);
+            const char *build_id = (char *)(nhdr + 1) + nhdr->n_namesz;
+            follow_debuglink_build_id(build_id, nhdr->n_descsz,
+			       num_traces, traces,
+			       objp, lines, offset);
+        }
 	goto finish;
     }
 
@@ -1950,7 +2358,11 @@ found_mach_header:
                     "__debug_info",
                     "__debug_line",
                     "__debug_ranges",
-                    "__debug_str"
+                    "__debug_str_offsets",
+                    "__debug_addr",
+                    "__debug_rnglists",
+                    "__debug_str",
+                    "__debug_line_str",
                 };
                 struct LP(segment_command) *scmd = (struct LP(segment_command) *)lcmd;
                 if (strcmp(scmd->segname, "__TEXT") == 0) {
@@ -1987,7 +2399,7 @@ found_mach_header:
                 char *strtab = file + cmd->stroff, *sname = 0;
                 uint32_t j;
                 uintptr_t saddr = 0;
-                /* kprintf("[%2d]: %x/symtab %p\n", i, cmd->cmd, p); */
+                /* kprintf("[%2d]: %x/symtab %p\n", i, cmd->cmd, (void *)p); */
                 for (j = 0; j < cmd->nsyms; j++) {
                     uintptr_t symsize, d;
                     struct LP(nlist) *e = &nl[j];
@@ -2039,7 +2451,7 @@ fail:
 #endif
 
 #define HAVE_MAIN_EXE_PATH
-#if defined(__FreeBSD__)
+#if defined(__FreeBSD__) || defined(__DragonFly__)
 # include <sys/sysctl.h>
 #endif
 /* ssize_t main_exe_path(void)
@@ -2048,17 +2460,21 @@ fail:
  * and returns strlen(binary_filename).
  * it is NUL terminated.
  */
-#if defined(__linux__)
+#if defined(__linux__) || defined(__NetBSD__)
 static ssize_t
 main_exe_path(void)
 {
-# define PROC_SELF_EXE "/proc/self/exe"
+# if defined(__linux__)
+#  define PROC_SELF_EXE "/proc/self/exe"
+# elif defined(__NetBSD__)
+#  define PROC_SELF_EXE "/proc/curproc/exe"
+# endif
     ssize_t len = readlink(PROC_SELF_EXE, binary_filename, PATH_MAX);
     if (len < 0) return 0;
     binary_filename[len] = 0;
     return len;
 }
-#elif defined(__FreeBSD__)
+#elif defined(__FreeBSD__) || defined(__DragonFly__)
 static ssize_t
 main_exe_path(void)
 {
@@ -2102,9 +2518,12 @@ print_line0(line_info_t *line, void *address)
     else if (!line->path) {
         kprintf("[0x%"PRIxPTR"]\n", addr);
     }
-    else if (!line->saddr || !line->sname) {
+    else if (!line->sname) {
         kprintf("%s(0x%"PRIxPTR") [0x%"PRIxPTR"]\n", line->path, addr-line->base_addr, addr);
     }
+    else if (!line->saddr) {
+        kprintf("%s(%s) [0x%"PRIxPTR"]\n", line->path, line->sname, addr);
+    }
     else if (line->line <= 0) {
         kprintf("%s(%s+0x%"PRIxPTR") [0x%"PRIxPTR"]\n", line->path, line->sname,
                 d, addr);
@@ -2141,6 +2560,7 @@ rb_dump_backtrace_with_lines(int num_traces, void **traces)
     obj_info_t *obj = NULL;
     /* 2 is NULL + main executable */
     void **dladdr_fbases = (void **)calloc(num_traces+2, sizeof(void *));
+
 #ifdef HAVE_MAIN_EXE_PATH
     char *main_path = NULL; /* used on printing backtrace */
     ssize_t len;
@@ -2171,8 +2591,8 @@ rb_dump_backtrace_with_lines(int num_traces, void **traces)
 	    /* if the binary is strip-ed, this may effect */
 	    for (p=dladdr_fbases; *p; p++) {
 		if (*p == info.dli_fbase) {
-		    lines[i].path = info.dli_fname;
-		    lines[i].sname = info.dli_sname;
+		    if (info.dli_fname) lines[i].path = info.dli_fname;
+		    if (info.dli_sname) lines[i].sname = info.dli_sname;
 		    goto next_line;
 		}
 	    }
@@ -2182,9 +2602,11 @@ rb_dump_backtrace_with_lines(int num_traces, void **traces)
 	    obj->base_addr = (uintptr_t)info.dli_fbase;
 	    path = info.dli_fname;
 	    obj->path = path;
-	    lines[i].path = path;
-            lines[i].sname = info.dli_sname;
-            lines[i].saddr = (uintptr_t)info.dli_saddr;
+	    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;
diff --git a/addr2line.h b/addr2line.h
index 4f6cf179ef..f09b665800 100644
--- a/addr2line.h
+++ b/addr2line.h
@@ -1,3 +1,5 @@
+#ifndef RUBY_ADDR2LINE_H
+#define RUBY_ADDR2LINE_H
 /**********************************************************************
 
   addr2line.h -
@@ -8,9 +10,6 @@
 
 **********************************************************************/
 
-#ifndef RUBY_ADDR2LINE_H
-#define RUBY_ADDR2LINE_H
-
 #if (defined(USE_ELF) || defined(HAVE_MACH_O_LOADER_H))
 
 void
diff --git a/appveyor.yml b/appveyor.yml
deleted file mode 100644
index 3d3a53afcf..0000000000
--- a/appveyor.yml
+++ /dev/null
@@ -1,143 +0,0 @@
----
-version: '{build}'
-shallow_clone: true
-platform:
-  - x64
-branches:
-  except:
-    - trunk # mirrored from trunk. avoid doubly building on it
-environment:
-  ruby_version: "24-%Platform%"
-  zlib_version: "1.2.11"
-  matrix:
-    # to reduce time for finishing all jobs, run the slowest msys2 build first.
-    - build: msys2
-      APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2015
-    - build: vs
-      vs: 120
-      ssl: OpenSSL
-      APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2013
-    - build: vs
-      vs: 140
-      ssl: OpenSSL-v111
-      APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2015
-  RELINE_TEST_ENCODING: "Windows-31J"
-  GEMS_FOR_TEST: "timezone tzinfo"
-  UPDATE_UNICODE: "UNICODE_FILES=. UNICODE_PROPERTY_FILES=. UNICODE_AUXILIARY_FILES=. UNICODE_EMOJI_FILES=."
-for:
--
-  matrix:
-    only:
-      - build: vs
-  install:
-    - ver
-    - chcp
-    - SET BITS=%Platform:x86=32%
-    - SET BITS=%BITS:x=%
-    - SET OPENSSL_DIR=C:\%ssl%-Win%BITS%
-    - CALL SET vcvars=%%^VS%VS%COMNTOOLS^%%..\..\VC\vcvarsall.bat
-    - SET vcvars
-    - '"%vcvars%" %Platform:x64=amd64%'
-    - SET ruby_path=C:\Ruby%ruby_version:-x86=%
-    - SET PATH=\usr\local\bin;%ruby_path%\bin;%PATH%;C:\msys64\mingw64\bin;C:\msys64\usr\bin
-    - ruby --version
-    - 'cl'
-    - echo> Makefile srcdir=.
-    - echo>> Makefile MSC_VER=0
-    - echo>> Makefile RT=none
-    - echo>> Makefile RT_VER=0
-    - echo>> Makefile BUILTIN_ENCOBJS=nul
-    - type win32\Makefile.sub >> Makefile
-    - nmake %mflags% touch-unicode-files
-    - nmake %mflags% %UPDATE_UNICODE% up incs
-    - del Makefile
-    - mkdir \usr\local\bin
-    - mkdir \usr\local\include
-    - mkdir \usr\local\lib
-    - curl -fsSL -o zlib%zlib_version:.=%.zip --retry 10 https://zlib.net/zlib%zlib_version:.=%.zip
-    - 7z x -o%APPVEYOR_BUILD_FOLDER%\ext\zlib zlib%zlib_version:.=%.zip
-    - for %%I in (%OPENSSL_DIR%\*.dll) do mklink /h \usr\local\bin\%%~nxI %%I
-    - attrib +r /s /d
-    - mkdir %Platform%-mswin_%vs%
-  build_script:
-    - cd %APPVEYOR_BUILD_FOLDER%
-    - cd %Platform%-mswin_%vs%
-    - ..\win32\configure.bat --without-ext=+,dbm,gdbm,readline --with-opt-dir=/usr/local --with-openssl-dir=%OPENSSL_DIR:\=/%
-    - nmake -l
-    - nmake install-nodoc
-    - \usr\bin\ruby -v -e "p :locale => Encoding.find('locale'), :filesystem => Encoding.find('filesystem')"
-    - if not "%GEMS_FOR_TEST%" == "" \usr\bin\gem install --no-document %GEMS_FOR_TEST%
-    - \usr\bin\ruby -ropenssl -e "puts 'Build    ' + OpenSSL::OPENSSL_VERSION, 'Runtime  ' + OpenSSL::OPENSSL_LIBRARY_VERSION"
-  test_script:
-    - set /a JOBS=%NUMBER_OF_PROCESSORS%
-    - nmake -l "TESTOPTS=-v -q" btest
-    - nmake -l "TESTOPTS=-v -q" test-basic
-    - nmake -l "TESTOPTS=-v --timeout-scale=3.0 --excludes=../test/excludes/_appveyor -j%JOBS% --exclude readline --exclude win32ole --exclude test_bignum --exclude test_syntax --exclude test_open-uri --exclude test_bundled_ca" test-all
-    # separately execute tests without -j which may crash worker with -j.
-    - nmake -l "TESTOPTS=-v --timeout-scale=3.0 --excludes=../test/excludes/_appveyor" test-all TESTS="../test/win32ole ../test/ruby/test_bignum.rb ../test/ruby/test_syntax.rb ../test/open-uri/test_open-uri.rb ../test/rubygems/test_bundled_ca.rb"
-    - nmake -l test-spec MSPECOPT=-fs # not using `-j` because sometimes `mspec -j` silently dies on Windows
--
-  matrix:
-    only:
-      - build: msys2
-  install:
-    - ver
-    - chcp
-    - set /a JOBS=%NUMBER_OF_PROCESSORS%
-    - set MSYS_NO_PATHCONV=1
-    - SET MSYSTEM=%Platform:x86=32%
-    - SET MSYSTEM=%MSYSTEM:x=MINGW%
-    - SET MSYS2_ARCH=%Platform:x86=i686%
-    - SET MSYS2_ARCH=%MSYS2_ARCH:x64=x86_64%
-    - set MSYSTEM_PREFIX=/mingw64
-    - set MINGW_CHOST=%MSYS2_ARCH%-w64-mingw32
-    - SET ruby_path=C:\Ruby%ruby_version:-x86=%
-    - cd ..
-    - mkdir build
-    - mkdir install
-    - SET PATH=%ruby_path%\bin;C:\msys64\%MSYSTEM%\bin;C:\msys64\usr\bin;%PATH%
-    - ruby --version
-  build_script:
-    - pacman -S --noconfirm --needed --noprogressbar --nodeps mingw-w64-x86_64-toolchain
-    - pacman -S --noconfirm --needed --noprogressbar mingw-w64-x86_64-gdbm mingw-w64-x86_64-gettext mingw-w64-x86_64-gmp mingw-w64-x86_64-libffi mingw-w64-x86_64-libyaml mingw-w64-x86_64-openssl mingw-w64-x86_64-ragel mingw-w64-x86_64-readline mingw-w64-x86_64-zlib
-    - cd %APPVEYOR_BUILD_FOLDER%
-    - set CFLAGS=-march=%MSYS2_ARCH:_=-% -mtune=generic -O3 -pipe
-    - set CXXFLAGS=%CFLAGS%
-    - set CPPFLAGS=-D_FORTIFY_SOURCE=2 -D__USE_MINGW_ANSI_STDIO=1 -DFD_SETSIZE=2048
-    - set LDFLAGS=-pipe
-    - sh -c "autoreconf -fi"
-    - cd ..\build
-    - sh ../ruby/configure --disable-install-doc --prefix=/. --build=%MINGW_CHOST% --host=%MINGW_CHOST% --target=%MINGW_CHOST%
-    - mingw32-make %mflags% touch-unicode-files
-    - mingw32-make -j%JOBS% %UPDATE_UNICODE% up incs
-    - mingw32-make -j%JOBS% V=1
-    - mingw32-make DESTDIR=../install install-nodoc
-    - if not "%GEMS_FOR_TEST%" == "" ..\install\bin\gem install --no-document %GEMS_FOR_TEST%
-    - ..\install\bin\ruby.exe -v -ropenssl -e "puts 'Build    ' + OpenSSL::OPENSSL_VERSION, 'Runtime  ' + OpenSSL::OPENSSL_LIBRARY_VERSION"
-  test_script:
-    - mingw32-make test
-    - mingw32-make test-all TESTOPTS="--retry --job-status=normal --show-skip --timeout-scale=1.5 --excludes=../ruby/test/excludes/_appveyor -j %JOBS% --exclude win32ole --exclude test_open-uri"
-    # separately execute tests without -j which may crash worker with -j.
-    - mingw32-make test-all TESTOPTS="--retry --job-status=normal --show-skip --timeout-scale=1.5 --excludes=../ruby/test/excludes/_appveyor" TESTS="../ruby/test/win32ole ../ruby/test/open-uri/test_open-uri.rb"
-    - mingw32-make test-spec MSPECOPT=-fs # not using `-j` because sometimes `mspec -j` silently dies on Windows
-notifications:
-  # Using "Webhook" with templated body to skip notification on Pull Request
-  - provider: Webhook
-    method: POST
-    url:
-      secure: iMINHMS0nZabaDsxN9omRDsekxzVvAAzEq5ev7lN6vb+gUETT+rbDKLGxBxBpEpxlnPlLdzroIJ+DTKlwfJA8VkGawTn9EXNsucH0OkSf2M= # AppVeyor CI
-    body: >-
-      {{^isPullRequest}}
-        {
-          "attachments": [
-            {
-              "text": "Build <{{buildUrl}}|#{{buildVersion}}> (<{{commitUrl}}|{{commitId}}>) of {{repositoryName}}@{{branch}} by {{commitAuthor}} {{status}}",
-              "color": "{{#passed}}good{{/passed}}{{#failed}}danger{{/failed}}"
-            }
-          ],
-          "channel": "#alerts"
-        }
-      {{/isPullRequest}}
-    on_build_success: false
-    on_build_failure: true
-    on_build_status_changed: true
diff --git a/array.c b/array.c
index 3717c3ff34..b76e9a64a3 100644
--- a/array.c
+++ b/array.c
@@ -10,22 +10,66 @@
   Copyright (C) 2000  Information-technology Promotion Agency, Japan
 
 **********************************************************************/
+
+#include "debug_counter.h"
+#include "id.h"
+#include "internal.h"
+#include "internal/array.h"
+#include "internal/compar.h"
+#include "internal/enum.h"
+#include "internal/gc.h"
+#include "internal/hash.h"
+#include "internal/numeric.h"
+#include "internal/object.h"
+#include "internal/proc.h"
+#include "internal/rational.h"
+#include "internal/vm.h"
+#include "probes.h"
 #include "ruby/encoding.h"
-#include "ruby/util.h"
 #include "ruby/st.h"
-#include "probes.h"
-#include "id.h"
-#include "debug_counter.h"
+#include "ruby/util.h"
 #include "transient_heap.h"
-#include "internal.h"
+#include "builtin.h"
 
 #if !ARRAY_DEBUG
+# undef NDEBUG
 # define NDEBUG
 #endif
 #include "ruby_assert.h"
 
 VALUE rb_cArray;
 
+/* Flags of RArray
+ *
+ * 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
+ *          by other arrays.
+ *          Note: Frozen arrays may be a shared root without this flag being
+ *                set. Frozen arrays do not have reference counting because
+ *                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.
+ */
+
 /* for OPTIMIZED_CMP: */
 #define id_cmp idCmp
 
@@ -33,28 +77,13 @@ VALUE rb_cArray;
 #define ARY_MAX_SIZE (LONG_MAX / (int)sizeof(VALUE))
 #define SMALL_ARRAY_LEN 16
 
+RBIMPL_ATTR_MAYBE_UNUSED()
 static int
 should_be_T_ARRAY(VALUE ary)
 {
     return RB_TYPE_P(ary, T_ARRAY);
 }
 
-static int
-should_not_be_shared_and_embedded(VALUE ary)
-{
-    return !FL_TEST((ary), ELTS_SHARED) || !FL_TEST((ary), RARRAY_EMBED_FLAG);
-}
-
-#define ARY_SHARED_P(ary) \
-  (assert(should_be_T_ARRAY((VALUE)(ary))), \
-   assert(should_not_be_shared_and_embedded((VALUE)ary)), \
-   FL_TEST_RAW((ary),ELTS_SHARED)!=0)
-
-#define ARY_EMBED_P(ary) \
-  (assert(should_be_T_ARRAY((VALUE)(ary))), \
-   assert(should_not_be_shared_and_embedded((VALUE)ary)), \
-   FL_TEST_RAW((ary), RARRAY_EMBED_FLAG) != 0)
-
 #define ARY_HEAP_PTR(a) (assert(!ARY_EMBED_P(a)), RARRAY(a)->as.heap.ptr)
 #define ARY_HEAP_LEN(a) (assert(!ARY_EMBED_P(a)), RARRAY(a)->as.heap.len)
 #define ARY_HEAP_CAPA(a) (assert(!ARY_EMBED_P(a)), assert(!ARY_SHARED_ROOT_P(a)), \
@@ -64,11 +93,11 @@ should_not_be_shared_and_embedded(VALUE ary)
 #define ARY_EMBED_LEN(a) \
     (assert(ARY_EMBED_P(a)), \
      (long)((RBASIC(a)->flags >> RARRAY_EMBED_LEN_SHIFT) & \
-	 (RARRAY_EMBED_LEN_MASK >> RARRAY_EMBED_LEN_SHIFT)))
+         (RARRAY_EMBED_LEN_MASK >> RARRAY_EMBED_LEN_SHIFT)))
 #define ARY_HEAP_SIZE(a) (assert(!ARY_EMBED_P(a)), assert(ARY_OWNS_HEAP_P(a)), ARY_CAPA(a) * sizeof(VALUE))
 
 #define ARY_OWNS_HEAP_P(a) (assert(should_be_T_ARRAY((VALUE)(a))), \
-                            !FL_TEST_RAW((a), ELTS_SHARED|RARRAY_EMBED_FLAG))
+                            !FL_TEST_RAW((a), RARRAY_SHARED_FLAG|RARRAY_EMBED_FLAG))
 
 #define FL_SET_EMBED(a) do { \
     assert(!ARY_SHARED_P(a)); \
@@ -80,9 +109,9 @@ should_not_be_shared_and_embedded(VALUE ary)
 #define FL_UNSET_EMBED(ary) FL_UNSET((ary), RARRAY_EMBED_FLAG|RARRAY_EMBED_LEN_MASK)
 #define FL_SET_SHARED(ary) do { \
     assert(!ARY_EMBED_P(ary)); \
-    FL_SET((ary), ELTS_SHARED); \
+    FL_SET((ary), RARRAY_SHARED_FLAG); \
 } while (0)
-#define FL_UNSET_SHARED(ary) FL_UNSET((ary), ELTS_SHARED)
+#define FL_UNSET_SHARED(ary) FL_UNSET((ary), RARRAY_SHARED_FLAG)
 
 #define ARY_SET_PTR(ary, p) do { \
     assert(!ARY_EMBED_P(ary)); \
@@ -92,7 +121,6 @@ should_not_be_shared_and_embedded(VALUE ary)
 #define ARY_SET_EMBED_LEN(ary, n) do { \
     long tmp_n = (n); \
     assert(ARY_EMBED_P(ary)); \
-    assert(!OBJ_FROZEN(ary)); \
     RBASIC(ary)->flags &= ~RARRAY_EMBED_LEN_MASK; \
     RBASIC(ary)->flags |= (tmp_n) << RARRAY_EMBED_LEN_SHIFT; \
 } while (0)
@@ -124,7 +152,7 @@ should_not_be_shared_and_embedded(VALUE ary)
     } \
 } while (0)
 
-#define ARY_CAPA(ary) (ARY_EMBED_P(ary) ? RARRAY_EMBED_LEN_MAX : \
+#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(ary, n) do { \
     assert(!ARY_EMBED_P(ary)); \
@@ -133,26 +161,25 @@ should_not_be_shared_and_embedded(VALUE ary)
     RARRAY(ary)->as.heap.aux.capa = (n); \
 } while (0)
 
-#define ARY_SHARED_ROOT(ary) (assert(ARY_SHARED_P(ary)), RARRAY(ary)->as.heap.aux.shared_root)
 #define ARY_SET_SHARED(ary, value) do { \
     const VALUE _ary_ = (ary); \
     const VALUE _value_ = (value); \
     assert(!ARY_EMBED_P(_ary_)); \
     assert(ARY_SHARED_P(_ary_)); \
-    assert(ARY_SHARED_ROOT_P(_value_)); \
+    assert(!OBJ_FROZEN(_ary_)); \
+    assert(ARY_SHARED_ROOT_P(_value_) || OBJ_FROZEN(_value_)); \
     RB_OBJ_WRITE(_ary_, &RARRAY(_ary_)->as.heap.aux.shared_root, _value_); \
 } while (0)
-#define RARRAY_SHARED_ROOT_FLAG FL_USER5
-#define ARY_SHARED_ROOT_P(ary) (assert(should_be_T_ARRAY((VALUE)(ary))), \
-                                FL_TEST_RAW((ary), RARRAY_SHARED_ROOT_FLAG))
-#define ARY_SHARED_ROOT_REFCNT(ary) \
-    (assert(ARY_SHARED_ROOT_P(ary)), RARRAY(ary)->as.heap.aux.capa)
-#define ARY_SHARED_ROOT_OCCUPIED(ary) (ARY_SHARED_ROOT_REFCNT(ary) == 1)
+
+#define ARY_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); \
     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)); \
     FL_SET((ary), RARRAY_SHARED_ROOT_FLAG); \
@@ -168,6 +195,65 @@ ARY_SET(VALUE a, long i, VALUE v)
 }
 #undef RARRAY_ASET
 
+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);
+    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);
+}
+
+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
+rb_ary_embeddable_p(VALUE ary)
+{
+    /* An array cannot be turned embeddable when the array is:
+     *  - Shared root: other objects may point to the buffer of this array
+     *    so we cannot make it embedded.
+     *  - Frozen: this array may also be a shared root without the shared root
+     *    flag.
+     *  - Shared: we don't want to re-embed an array that points to a shared
+     *    root (to save memory).
+     */
+    return !(ARY_SHARED_ROOT_P(ary) || OBJ_FROZEN(ary) || ARY_SHARED_P(ary));
+}
+
+size_t
+rb_ary_size_as_embedded(VALUE ary)
+{
+    size_t real_size;
+
+    if (ARY_EMBED_P(ary)) {
+        real_size = ary_embed_size(ARY_EMBED_LEN(ary));
+    }
+    else if (rb_ary_embeddable_p(ary)) {
+        real_size = ary_embed_size(ARY_HEAP_CAPA(ary));
+    }
+    else {
+        real_size = sizeof(struct RArray);
+    }
+    return real_size;
+}
+
 
 #if ARRAY_DEBUG
 #define ary_verify(ary) ary_verify_(ary, __FILE__, __LINE__)
@@ -177,19 +263,19 @@ ary_verify_(VALUE ary, const char *file, int line)
 {
     assert(RB_TYPE_P(ary, T_ARRAY));
 
-    if (FL_TEST(ary, ELTS_SHARED)) {
-        VALUE root = RARRAY(ary)->as.heap.aux.shared_root;
+    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);
         long len = ARY_HEAP_LEN(ary), root_len = RARRAY_LEN(root);
-        assert(FL_TEST(root, RARRAY_SHARED_ROOT_FLAG));
+        assert(ARY_SHARED_ROOT_P(root) || OBJ_FROZEN(root));
         assert(root_ptr <= ptr && ptr + len <= root_ptr + root_len);
         ary_verify(root);
     }
     else if (ARY_EMBED_P(ary)) {
         assert(!RARRAY_TRANSIENT_P(ary));
         assert(!ARY_SHARED_P(ary));
-        assert(RARRAY_LEN(ary) <= RARRAY_EMBED_LEN_MAX);
+        assert(RARRAY_LEN(ary) <= ary_embed_capa(ary));
     }
     else {
 #if 1
@@ -204,9 +290,11 @@ ary_verify_(VALUE ary, const char *file, int line)
 #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();
 
@@ -240,10 +328,10 @@ rb_ary_ptr_use_end(VALUE ary)
 }
 
 void
-rb_mem_clear(register VALUE *mem, register long size)
+rb_mem_clear(VALUE *mem, long size)
 {
     while (size--) {
-	*mem++ = Qnil;
+        *mem++ = Qnil;
     }
 }
 
@@ -251,7 +339,7 @@ static void
 ary_mem_clear(VALUE ary, long beg, long size)
 {
     RARRAY_PTR_USE_TRANSIENT(ary, ptr, {
-	rb_mem_clear(ptr + beg, size);
+        rb_mem_clear(ptr + beg, size);
     });
 }
 
@@ -259,7 +347,7 @@ static inline void
 memfill(register VALUE *mem, register long size, register VALUE val)
 {
     while (size--) {
-	*mem++ = val;
+        *mem++ = val;
     }
 }
 
@@ -267,8 +355,8 @@ static void
 ary_memfill(VALUE ary, long beg, long size, VALUE val)
 {
     RARRAY_PTR_USE_TRANSIENT(ary, ptr, {
-	memfill(ptr + beg, size, val);
-	RB_OBJ_WRITTEN(ary, Qundef, val);
+        memfill(ptr + beg, size, val);
+        RB_OBJ_WRITTEN(ary, Qundef, val);
     });
 }
 
@@ -337,14 +425,16 @@ ary_heap_free(VALUE ary)
     }
 }
 
-static void
+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);
@@ -362,6 +452,8 @@ ary_heap_realloc(VALUE ary, size_t new_capa)
         SIZED_REALLOC_N(RARRAY(ary)->as.heap.ptr, VALUE, new_capa, old_capa);
     }
     ary_verify(ary);
+
+    return alloc_capa;
 }
 
 #if USE_TRANSIENT_HEAP
@@ -369,14 +461,11 @@ 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);
-        long len  = ARY_HEAP_LEN(ary);
-
-        if (ARY_SHARED_ROOT_P(ary)) {
-            capa = len;
-        }
 
         assert(ARY_OWNS_HEAP_P(ary));
         assert(RARRAY_TRANSIENT_P(ary));
@@ -418,6 +507,27 @@ rb_ary_detransient(VALUE ary)
 }
 #endif
 
+void
+rb_ary_make_embedded(VALUE ary)
+{
+    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);
+
+        // 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));
+        }
+    }
+}
+
 static void
 ary_resize_capa(VALUE ary, long capacity)
 {
@@ -425,7 +535,8 @@ ary_resize_capa(VALUE ary, long capacity)
     assert(!OBJ_FROZEN(ary));
     assert(!ARY_SHARED_P(ary));
 
-    if (capacity > RARRAY_EMBED_LEN_MAX) {
+    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);
@@ -436,9 +547,9 @@ ary_resize_capa(VALUE ary, long capacity)
             ARY_SET_HEAP_LEN(ary, len);
         }
         else {
-            ary_heap_realloc(ary, capacity);
+            new_capa = ary_heap_realloc(ary, capacity);
         }
-        ARY_SET_CAPA(ary, capacity);
+        ARY_SET_CAPA(ary, new_capa);
     }
     else {
         if (!ARY_EMBED_P(ary)) {
@@ -476,10 +587,10 @@ ary_double_capa(VALUE ary, long min)
     long new_capa = ARY_CAPA(ary) / 2;
 
     if (new_capa < ARY_DEFAULT_SIZE) {
-	new_capa = ARY_DEFAULT_SIZE;
+        new_capa = ARY_DEFAULT_SIZE;
     }
     if (new_capa >= ARY_MAX_SIZE - min) {
-	new_capa = (ARY_MAX_SIZE - min) / 2;
+        new_capa = (ARY_MAX_SIZE - min) / 2;
     }
     new_capa += min;
     ary_resize_capa(ary, new_capa);
@@ -490,39 +601,40 @@ ary_double_capa(VALUE ary, long min)
 static void
 rb_ary_decrement_share(VALUE shared_root)
 {
-    if (shared_root) {
-        long num = ARY_SHARED_ROOT_REFCNT(shared_root) - 1;
-	if (num == 0) {
-            rb_ary_free(shared_root);
-            rb_gc_force_recycle(shared_root);
-	}
-	else if (num > 0) {
-            ARY_SET_SHARED_ROOT_REFCNT(shared_root, num);
-	}
+    if (!OBJ_FROZEN(shared_root)) {
+        long num = ARY_SHARED_ROOT_REFCNT(shared_root);
+        ARY_SET_SHARED_ROOT_REFCNT(shared_root, num - 1);
     }
 }
 
 static void
 rb_ary_unshare(VALUE ary)
 {
-    VALUE shared_root = RARRAY(ary)->as.heap.aux.shared_root;
+    VALUE shared_root = ARY_SHARED_ROOT(ary);
     rb_ary_decrement_share(shared_root);
     FL_UNSET_SHARED(ary);
 }
 
-static inline void
-rb_ary_unshare_safe(VALUE ary)
+static void
+rb_ary_reset(VALUE ary)
 {
-    if (ARY_SHARED_P(ary) && !ARY_EMBED_P(ary)) {
-	rb_ary_unshare(ary);
+    if (ARY_OWNS_HEAP_P(ary)) {
+        ary_heap_free(ary);
+    }
+    else if (ARY_SHARED_P(ary)) {
+        rb_ary_unshare(ary);
     }
+
+    FL_SET_EMBED(ary);
+    ARY_SET_EMBED_LEN(ary, 0);
 }
 
 static VALUE
 rb_ary_increment_share(VALUE shared_root)
 {
-    long num = ARY_SHARED_ROOT_REFCNT(shared_root);
-    if (num >= 0) {
+    if (!OBJ_FROZEN(shared_root)) {
+        long num = ARY_SHARED_ROOT_REFCNT(shared_root);
+        assert(num >= 0);
         ARY_SET_SHARED_ROOT_REFCNT(shared_root, num + 1);
     }
     return shared_root;
@@ -545,34 +657,33 @@ rb_ary_modify_check(VALUE ary)
 }
 
 void
-rb_ary_modify(VALUE ary)
+rb_ary_cancel_sharing(VALUE ary)
 {
-    rb_ary_modify_check(ary);
     if (ARY_SHARED_P(ary)) {
-	long shared_len, len = RARRAY_LEN(ary);
+        long shared_len, len = RARRAY_LEN(ary);
         VALUE shared_root = ARY_SHARED_ROOT(ary);
 
         ary_verify(shared_root);
 
-        if (len <= RARRAY_EMBED_LEN_MAX) {
-	    const VALUE *ptr = ARY_HEAP_PTR(ary);
+        if (len <= ary_embed_capa(ary)) {
+            const VALUE *ptr = ARY_HEAP_PTR(ary);
             FL_UNSET_SHARED(ary);
             FL_SET_EMBED(ary);
-	    MEMCPY((VALUE *)ARY_EMBED_PTR(ary), ptr, VALUE, len);
+            MEMCPY((VALUE *)ARY_EMBED_PTR(ary), ptr, VALUE, len);
             rb_ary_decrement_share(shared_root);
             ARY_SET_EMBED_LEN(ary, len);
         }
         else if (ARY_SHARED_ROOT_OCCUPIED(shared_root) && len > ((shared_len = RARRAY_LEN(shared_root))>>1)) {
             long shift = RARRAY_CONST_PTR_TRANSIENT(ary) - RARRAY_CONST_PTR_TRANSIENT(shared_root);
-	    FL_UNSET_SHARED(ary);
+            FL_UNSET_SHARED(ary);
             ARY_SET_PTR(ary, RARRAY_CONST_PTR_TRANSIENT(shared_root));
-	    ARY_SET_CAPA(ary, shared_len);
+            ARY_SET_CAPA(ary, shared_len);
             RARRAY_PTR_USE_TRANSIENT(ary, ptr, {
-		MEMMOVE(ptr, ptr+shift, VALUE, len);
-	    });
+                MEMMOVE(ptr, ptr+shift, VALUE, len);
+            });
             FL_SET_EMBED(shared_root);
             rb_ary_decrement_share(shared_root);
-	}
+        }
         else {
             VALUE *ptr = ary_heap_alloc(ary, len);
             MEMCPY(ptr, ARY_HEAP_PTR(ary), VALUE, len);
@@ -581,11 +692,18 @@ rb_ary_modify(VALUE ary)
             ARY_SET_PTR(ary, ptr);
         }
 
-	rb_gc_writebarrier_remember(ary);
+        rb_gc_writebarrier_remember(ary);
     }
     ary_verify(ary);
 }
 
+void
+rb_ary_modify(VALUE ary)
+{
+    rb_ary_modify_check(ary);
+    rb_ary_cancel_sharing(ary);
+}
+
 static VALUE
 ary_ensure_room_for_push(VALUE ary, long add_len)
 {
@@ -594,40 +712,40 @@ ary_ensure_room_for_push(VALUE ary, long add_len)
     long capa;
 
     if (old_len > ARY_MAX_SIZE - add_len) {
-	rb_raise(rb_eIndexError, "index %ld too big", new_len);
+        rb_raise(rb_eIndexError, "index %ld too big", new_len);
     }
     if (ARY_SHARED_P(ary)) {
-	if (new_len > RARRAY_EMBED_LEN_MAX) {