Adopt clang-format for code formatting

Author: st0012

.clang-format

@@ -0,0 +1,74 @@
+---
+Language: Cpp
+
+# Indentation
+UseTab: Never
+IndentWidth: 4
+BreakBeforeBraces: Attach
+IndentCaseLabels: false
+NamespaceIndentation: None
+ContinuationIndentWidth: 4
+IndentPPDirectives: None
+IndentWrappedFunctionNames: false
+AccessModifierOffset: -2
+
+# Alignment
+AlignAfterOpenBracket: BlockIndent
+AlignConsecutiveAssignments: false
+AlignConsecutiveDeclarations: false
+AlignConsecutiveMacros: false
+AlignEscapedNewlines: Left
+AlignOperands: false
+AlignTrailingComments: true
+DerivePointerAlignment: false
+PointerAlignment: Right
+
+# Function calls formatting
+BinPackArguments: false
+BinPackParameters: false
+AllowAllArgumentsOnNextLine: false
+ExperimentalAutoDetectBinPacking: false
+PenaltyBreakBeforeFirstCallParameter: 1
+AlwaysBreakAfterDefinitionReturnType: None
+
+# Wrapping and Breaking
+ColumnLimit: 0
+AllowShortBlocksOnASingleLine: Never
+AllowShortCaseLabelsOnASingleLine: false
+AllowShortFunctionsOnASingleLine: All
+AllowShortIfStatementsOnASingleLine: Always
+AllowShortLoopsOnASingleLine: false
+AlwaysBreakAfterReturnType: None
+AlwaysBreakBeforeMultilineStrings: false
+AlwaysBreakTemplateDeclarations: No
+BreakBeforeBinaryOperators: None
+BreakBeforeTernaryOperators: false
+BreakConstructorInitializers: BeforeColon
+BreakInheritanceList: BeforeColon
+BreakStringLiterals: false
+CompactNamespaces: false
+ConstructorInitializerAllOnOneLineOrOnePerLine: false
+Cpp11BracedListStyle: false
+ReflowComments: false
+SortIncludes: Never
+
+# Spaces
+SpaceAfterCStyleCast: true
+SpaceAfterLogicalNot: false
+SpaceAfterTemplateKeyword: true
+SpaceBeforeAssignmentOperators: true
+SpaceBeforeCpp11BracedList: true
+SpaceBeforeCtorInitializerColon: true
+SpaceBeforeInheritanceColon: true
+SpaceBeforeParens: ControlStatements
+SpaceBeforeRangeBasedForLoopColon: true
+SpaceBeforeSquareBrackets: false
+SpaceInEmptyBlock: false
+SpaceInEmptyParentheses: false
+SpacesBeforeTrailingComments: 1
+SpacesInAngles: false
+SpacesInCStyleCastParentheses: false
+SpacesInConditionalStatement: false
+SpacesInContainerLiterals: true
+SpacesInParentheses: false
+SpacesInSquareBrackets: false

.github/workflows/clang-format.yml

@@ -0,0 +1,62 @@
+name: C Code Formatting Check
+
+on:
+  push:
+    paths:
+      - '**.c'
+      - '**.h'
+      - '.clang-format'
+      - '.github/workflows/clang-format.yml'
+  pull_request:
+    paths:
+      - '**.c'
+      - '**.h'
+      - '.clang-format'
+      - '.github/workflows/clang-format.yml'
+
+jobs:
+  format-check:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: "3.4"
+          bundler-cache: none
+      - name: Set working directory as safe
+        run: git config --global --add safe.directory $(pwd)
+      - name: Set up permission
+        run: chmod -R o-w /opt/hostedtoolcache/Ruby
+      - name: Install dependencies
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y libdb-dev curl autoconf automake m4 libtool
+      - name: Install clang-format from LLVM
+        run: |
+          wget -O - https://apt.llvm.org/llvm-snapshot.gpg.key | sudo apt-key add -
+          sudo apt-add-repository "deb http://apt.llvm.org/jammy/ llvm-toolchain-jammy main"
+          sudo apt-get update
+          sudo apt-get install -y clang-format
+          clang-format --version
+      - name: Install Re2c
+        run: |
+          cd /tmp
+          curl -L https://github.com/skvadrik/re2c/archive/refs/tags/3.1.tar.gz > re2c-3.1.tar.gz
+          tar xf re2c-3.1.tar.gz
+          cd re2c-3.1
+          autoreconf -i -W all
+          ./configure
+          make
+          sudo make install
+      - name: Update rubygems & bundler
+        run: |
+          ruby -v
+          gem update --system
+      - name: bin/setup
+        run: |
+          bin/setup
+      - name: Check C code formatting
+        run: |
+          clang-format --version
+          bundle exec rake templates
+          bundle exec rake format:c_check

.vscode/extensions.json

@@ -0,0 +1,5 @@
+{
+  "recommendations": [
+    "llvm-vs-code-extensions.vscode-clangd"
+  ]
+}

.vscode/settings.json

@@ -0,0 +1,19 @@
+{
+  "clangd.onConfigChanged": "restart",
+  "[c]": {
+    "editor.formatOnSave": true,
+    "editor.defaultFormatter": "llvm-vs-code-extensions.vscode-clangd"
+  },
+  "[cpp]": {
+    "editor.formatOnSave": true,
+    "editor.defaultFormatter": "llvm-vs-code-extensions.vscode-clangd"
+  },
+  "[h]": {
+    "editor.formatOnSave": true,
+    "editor.defaultFormatter": "llvm-vs-code-extensions.vscode-clangd"
+  },
+  "[hpp]": {
+    "editor.formatOnSave": true,
+    "editor.defaultFormatter": "llvm-vs-code-extensions.vscode-clangd"
+  }
+}

README.md

@@ -198,6 +198,43 @@ After checking out the repo, run `bin/setup` to install dependencies. Then, run
 
 To install this gem onto your local machine, run `bundle exec rake install`. To release a new version, update the version number in `version.rb`, and then run `bundle exec rake release`, which will create a git tag for the version, push git commits and tags, and push the `.gem` file to [rubygems.org](https://rubygems.org).
 
+### C Code Formatting
+
+This project uses `clang-format` to enforce consistent formatting of C code with a `.clang-format` configuration in the root directory.
+
+#### Setup
+
+First, install clang-format:
+
+```bash
+# macOS
+brew install clang-format
+
+# Ubuntu/Debian
+sudo apt-get install clang-format
+
+# Windows
+choco install llvm
+```
+
+#### Usage
+
+Format all C source files:
+
+```bash
+rake format:c
+```
+
+Check formatting without making changes:
+
+```bash
+rake format:c_check
+```
+
+#### Editor Integration
+
+For VS Code users, install the "clangd" extension which will automatically use the project's `.clang-format` file.
+
 ## Contributing
 
 Bug reports and pull requests are welcome on GitHub at https://github.com/ruby/rbs.

Rakefile

@@ -49,6 +49,87 @@ task :confirm_templates => :templates do
   sh "git diff --exit-code -- include src"
 end
 
+# Task to format C code using clang-format
+namespace :format do
+  dirs = ["src", "ext", "include"]
+  excluded_files = ["ext/rbs_extension/lexer.c", "src/constants.c", "src/ruby_objs.c"]
+
+  # Find all C source and header files, then filter out excluded files
+  files = `find #{dirs.join(" ")} -type f \\( -name "*.c" -o -name "*.h" \\)`.split("\n").reject do |file|
+    excluded_files.include?(file)
+  end
+
+  desc "Format C source files using clang-format"
+  task :c do
+    puts "Formatting C files..."
+
+    # Check if clang-format is installed
+    unless system("which clang-format > /dev/null 2>&1")
+      abort "Error: clang-format not found. Please install clang-format first."
+    end
+
+    if files.empty?
+      puts "No C files found to format"
+      next
+    end
+
+    puts "Found #{files.length} files to format (excluding generated files)"
+
+    exit_status = 0
+    files.each do |file|
+      puts "Formatting #{file}"
+      unless system("clang-format -i -style=file #{file}")
+        puts "❌ Error formatting #{file}"
+        exit_status = 1
+      end
+    end
+
+    exit exit_status unless exit_status == 0
+    puts "✅ All files formatted successfully"
+  end
+
+  desc "Check if C source files are properly formatted"
+  task :c_check do
+    puts "Checking C file formatting..."
+
+    # Check if clang-format is installed
+    unless system("which clang-format > /dev/null 2>&1")
+      abort "Error: clang-format not found. Please install clang-format first."
+    end
+
+    if files.empty?
+      puts "No C files found to check"
+      next
+    end
+
+    puts "Found #{files.length} files to check (excluding generated files)"
+
+    needs_format = false
+    files.each do |file|
+      formatted = `clang-format -style=file #{file}`
+      original = File.read(file)
+
+      if formatted != original
+        puts "❌ #{file} needs formatting"
+        puts "Diff:"
+        # Save formatted version to temp file and run diff
+        temp_file = "#{file}.formatted"
+        File.write(temp_file, formatted)
+        system("diff -u #{file} #{temp_file}")
+        File.unlink(temp_file)
+        needs_format = true
+      end
+    end
+
+    if needs_format
+      warn "Some files need formatting. Run 'rake format:c' to format them."
+      exit 1
+    else
+      puts "✅ All files are properly formatted"
+    end
+  end
+end
+
 rule ".c" => ".re" do |t|
   puts "⚠️⚠️⚠️ #{t.name} is older than #{t.source}. You may need to run `rake lexer` ⚠️⚠️⚠️"
 end