name: Compiler testing

on: [push, pull_request]

jobs:
  pre_job:
    runs-on: ubuntu-latest
    outputs:
      should_skip: ${{ steps.skip_check.outputs.should_skip }}
    steps:
      - id: skip_check
        uses: fkirc/skip-duplicate-actions@v5
        with:
          paths_ignore: '["**/README.md", "docs/**", "guidelines/**"]'
          # cancel previous builds if a new commit is pushed
          cancel_others: 'true'
          # only run on push *or* pull_request, not both
          concurrent_skipping: 'same_content_newer'

  test-compile:
    runs-on: ${{ matrix.os }}
    needs: pre_job
    if: needs.pre_job.outputs.should_skip != 'true'
    env:
      CXXFLAGS: ${{ startsWith(matrix.compiler, 'gcc') && '-Wp,-D_GLIBCXX_ASSERTIONS' || ''}}
      CC_SHORT: ${{ startsWith(matrix.compiler, 'gcc') && 'gcc' || 'clang' }}
    strategy:
      matrix:
        os:
          - ubuntu-latest
        compiler:
          # oldest supported
          - 'clang-14'
          - 'gcc-10'
          # newest, make sure to update maximum standard step to match
          - 'clang-18'
          - 'gcc-13'
        include:
          # macOS
          - os: macos-13
            compiler: 'clang'
          # oldest clang not available on ubuntu-latest
          - os: ubuntu-20.04
            compiler: 'clang-10'
      fail-fast: false
    steps:
      - name: Checkout Yosys
        uses: actions/checkout@v4
        with:
          submodules: true

      - name: Setup environment
        uses: ./.github/actions/setup-build-env

      - name: Setup Cpp
        uses: aminya/setup-cpp@v1
        with:
          compiler: ${{ matrix.compiler }}

      - name: Tool versions
        shell: bash
        run: |
          $CC --version
          $CXX --version

      # minimum standard
      - name: Build C++17
        shell: bash
        run: |
          make config-$CC_SHORT
          make -j$procs CXXSTD=c++17 compile-only

      # maximum standard, only on newest compilers
      - name: Build C++20
        if: ${{ matrix.compiler == 'clang-18' || matrix.compiler == 'gcc-13' }}
        shell: bash
        run: |
          make config-$CC_SHORT
          make -j$procs CXXSTD=c++20 compile-only