clang.yml

name: Clang

on:
  push:
    branches:
      - '**'
  pull_request:
    branches:
      - main
  schedule:
    - cron: '0 0 * * 0'

jobs:
  build:
    runs-on: ${{ matrix.os }}

    strategy:
      matrix:
        os: [ubuntu-latest, macos-latest]
        std_version: [20, 23]

    steps:
      - name: Checkout
        uses: actions/checkout@v4

      - name: Add homebrew to PATH (Linux only)
        if: runner.os == 'Linux'
        run: |
          echo "/home/linuxbrew/.linuxbrew/bin" >> $GITHUB_PATH

      - name: Get LLVM and Ninja via Homebrew
        run: |
          brew install llvm ninja
          echo "CC=$(brew --prefix llvm)/bin/clang" >> "$GITHUB_ENV"
          echo "CXX=$(brew --prefix llvm)/bin/clang++" >> "$GITHUB_ENV"

      - name: Cache libc++ build
        id: cache-libcxx
        uses: actions/cache@v4
        with:
          path: llvm-project/build
          key: ${{ runner.os }}-libcxx

      - name: Make local build of libc++ with Standard Library Module (when cache miss)
        if: steps.cache-libcxx.outputs.cache-hit != 'true'
        run: |
          git clone https://github.com/llvm/llvm-project.git
          cd llvm-project
          mkdir build
          cmake -G Ninja -S runtimes -B build                   \
            -DLLVM_ENABLE_RUNTIMES="libcxx;libcxxabi;libunwind" \
            -DLLVM_INCLUDE_TESTS=OFF
          ninja -C build

      - name: Configure
        run: |
          mkdir build
          cmake -S . -G Ninja -B build                                \
            -DCMAKE_CXX_STANDARD=${{ matrix.std_version }}            \
            -DLIBCXX_BUILD=${{ github.workspace }}/llvm-project/build

      - name: Build
        run: |
          cmake --build build -t CppStandardLibraryModule --config Release

      - name: Run executable
        run: |
          ./build/CppStandardLibraryModule