.github/workflows/libc-overlay-tests.yml

# This workflow is for pre-commit testing of the LLVM-libc project.
name: LLVM-libc Pre-commit Overlay Tests
permissions:
  contents: read
on:
  pull_request:
    paths:
      - 'libc/**'
      - '.github/workflows/libc-overlay-tests.yml'

jobs:
  build:
    if: github.repository_owner == 'llvm'
    timeout-minutes: 30
    runs-on: ${{ matrix.os }}
    container: ${{ matrix.container || null }}
    strategy:
      # Set fail-fast to false to ensure that feedback is delivered for all matrix combinations.
      fail-fast: false
      matrix:
        include:
          # TODO: add linux gcc when it is fixed
          - os: ubuntu-24.04
            container: 'ghcr.io/llvm/libc-ubuntu-24.04:latest@sha256:a902fb53bdad5e4a4bb6c11b6584e717a7b3d6e886f1ea58e11f95e46226249c'
            compiler:
              c_compiler: clang-23
              cpp_compiler: clang++-23
            linker: lld-23
          - os: ubuntu-24.04-arm
            container: 'ghcr.io/llvm/arm64v8/libc-ubuntu-24.04:latest@sha256:138636a45bb70f7b51a858b282e66291cb3c5c85371afee09032a5e09b263395'
            compiler:
              c_compiler: clang-23
              cpp_compiler: clang++-23
            linker: lld-23
          - os: windows-2022
            compiler:
              c_compiler: clang-cl
              cpp_compiler: clang-cl
          - os: windows-2025
            compiler:
              c_compiler: clang-cl
              cpp_compiler: clang-cl
          - os: macos-15
            compiler:
              c_compiler: clang
              cpp_compiler: clang++
    
    steps:
    - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
      with:
        persist-credentials: false
    
    # Libc's build is relatively small comparing with other components of LLVM.
    # A fresh linux overlay takes about 180MiB of uncompressed disk space, which can
    # be compressed into ~40MiB. MacOS and Windows overlay builds are less than 10MiB
    # after compression. Limiting the cache size to 1G should be enough.
    # Prefer sccache as it is modern and it has a guarantee to work with MSVC.
    # Do not use direct GHAC access even though it is supported by sccache. GHAC rejects
    # frequent small object writes.
    - name: Setup ccache
      uses: hendrikmuhs/ccache-action@33522472633dbd32578e909b315f5ee43ba878ce # v1.2.22
      with:
        max-size: 1G
        key: libc_overlay_build_v2_${{ matrix.os }}_${{ matrix.compiler.c_compiler }}
        variant: sccache
    
    # Chocolatey is shipped with Windows runners. Windows Server 2025 recommends WinGet.
    # Consider migrating to WinGet when Windows Server 2025 is available.
    - name: Prepare dependencies (Windows)
      if: runner.os == 'Windows'
      run: |
        choco install ninja
    
    - name: Prepare dependencies (macOS)
      if: runner.os == 'macOS'
      run: |
        brew install ninja

    # Use MinSizeRel to reduce the size of the build.
    # Notice that CMP0141=NEW and MSVC_DEBUG_INFORMATION_FORMAT=Embedded are required
    # by the sccache tool.
    - name: Configure CMake
      run: >
        cmake -B build
        -DCMAKE_CXX_COMPILER=${{ matrix.compiler.cpp_compiler }}
        -DCMAKE_C_COMPILER=${{ matrix.compiler.c_compiler }}
        -DCMAKE_BUILD_TYPE=RelWithDebInfo
        -DCMAKE_C_COMPILER_LAUNCHER=sccache
        -DCMAKE_CXX_COMPILER_LAUNCHER=sccache
        -DCMAKE_POLICY_DEFAULT_CMP0141=NEW
        -DCMAKE_MSVC_DEBUG_INFORMATION_FORMAT=Embedded
        -DLIBC_COMPILE_OPTIONS_NATIVE=""
        -DLLVM_ENABLE_RUNTIMES=libc
        -DLLVM_USE_LINKER="${{ matrix.linker }}"
        -G Ninja
        -S runtimes

    - name: Build
      run: >
        cmake 
        --build build
        --parallel 
        --target libc

    - name: Test
      run: >
        cmake 
        --build build 
        --parallel 
        --target check-libc