runnable_cxx.yml

# Github action to test for C++ interoperability
#
# Most tests in the test-suite run on the CI when it comes to cross-platform testing.
# However, the dlang auto-tester uses somewhat old host C/C++ compiler.
# This is good for testing compatibility with e.g. LTS distributions,
# but becomes problematic when we want to test more cutting-edge features,
# such as newer C++ standards (C++17, C++20, etc...).
#
# This is the reason why we have this action: we have full control over the toolchain,
# and it is cross platform. The supported platforms are whatever Github Actions support,
# which is usually whatever the vendor (Canonical, Apple, Microsoft) supports.
#
# Notes:
# - When debugging/troubleshooting, make sure to check the printed compiler versions.
# - Try to use the native Github action syntax (${{ expression }}) when possible,
#   as they are substituted with their value in the logs, unlike env variable.
#   For example use `${{ github.workspace }}` over `${GITHUB_WORKSPACE}`
#
# TODO:
# - Test clang on Windows? (note: probably not all tests respect a CC/CXX env variable on Windows)
name: C++ interop tests

# Only triggers on pushes to master & stable, as well as PR to master and stable
# Sometimes reverts appear in the upstream repository (e.g. when the revert button
# is clicked by a contributor with commit access), this should be tested as PR).
#
# Also note that Github actions does not retrigger on target branch changes,
# hence the check on push.
on:
  pull_request:
    branches:
      - master
      - stable
  push:
    branches:
      - master
      - stable
      # Use this branch name in your fork to test changes
      - github-actions

concurrency:
  group: ${{ github.workflow }}-${{ github.ref }}
  cancel-in-progress: true

jobs:
  main:
    name: Run
    if: github.repository == 'dlang/dmd'

    strategy:
      # Since those tests takes very little time, don't use `fail-fast`.
      # If runtime expand, we might want to comment this out,
      # as most failing PRs do so because they don't compile / something is broken,
      # very few PRs actually benefit from this.
      fail-fast: false
      matrix:
        include:
          # Linux, clang:
          # NOTE: cannot test MODEL=32 with clang on Linux, due to a single failure as of April 2025:
          #       runnable_cxx/cppa.d:261: cppa.check13956: Assertion `arg6 == 6' failed.
          - { os: ubuntu-24.04, compiler: clang-18, model: 64 }
          - { os: ubuntu-22.04, compiler: clang-15, model: 64 }
          - { os: ubuntu-24.04, compiler: clang-14, model: 64 }
          - { os: ubuntu-22.04, compiler: clang-11, model: 64 }
          # Linux, g++:
          - { os: ubuntu-24.04, compiler: g++-13, model: 64 }
          - { os: ubuntu-24.04, compiler: g++-13, model: 32 }
          - { os: ubuntu-22.04, compiler: g++-12, model: 64 }
          - { os: ubuntu-22.04, compiler: g++-12, model: 32 }
          - { os: ubuntu-22.04, compiler: g++-9,  model: 64 }
          - { os: ubuntu-22.04, compiler: g++-9,  model: 32 }
          # macOS, Apple clang from Xcode:
          # Disabled due to issues with x87: https://github.com/dlang/dmd/issues/21987
          #- { os: macos-15, xcode: '16.4',   model: 64 }
          - { os: macos-14, xcode: '16.2',   model: 64 }
          # Windows, cl.exe from Visual Studio:
          # NOTE: as of April 2025, image windows-2025 only has VS 2022, so no point in testing that image too
          - { os: windows-2022, model: 64 }
          - { os: windows-2022, model: 32 }

    runs-on: ${{ matrix.os }}
    defaults:
      run:
        shell: bash
    steps:

    - name: Set environment variable N (parallelism)
      run: echo "N=$(${{ runner.os == 'macOS' && 'sysctl -n hw.logicalcpu' || 'nproc' }})" >> $GITHUB_ENV
    - name: Set environment variable MODEL
      run: echo "MODEL=${{ matrix.model }}" >> $GITHUB_ENV

    - name: 'macOS: Upgrade GNU make'
      if: runner.os == 'macOS'
      run: |
        set -eux
        brew install make
        sudo ln -s $(which gmake) /usr/local/bin/make
        make --version

    ########################################
    #    Setting up the host D compiler    #
    ########################################
    - name: Install D host compiler
      uses: dlang-community/setup-dlang@v2
    - name: 'Posix: Clear LD_LIBRARY_PATH environment variable' # don't use host druntime/Phobos .so/.dylib etc.
      if: runner.os != 'Windows'
      run: echo "LD_LIBRARY_PATH=" >> $GITHUB_ENV

    ##############################################
    # Find out which branch we need to check out #
    ##############################################
    - name: Determine base branch
      id: base_branch
      run: |
        # For pull requests, base_ref will not be empty
        if [ ! -z ${{ github.base_ref }} ]; then
            echo "branch=${{ github.base_ref }}" >> $GITHUB_OUTPUT
        # Otherwise, use whatever ref we have:
        # For branches this in the format 'refs/heads/<branch_name>',
        # and for tags it is refs/tags/<tag_name>.
        else
            echo "branch=${{ github.ref }}" >> $GITHUB_OUTPUT
        fi

    #####################################
    #    Checking out DMD and Phobos    #
    #####################################
    - name: Checkout DMD
      uses: actions/checkout@v4
      with:
        path: dmd
        persist-credentials: false
    - name: Checkout Phobos
      uses: actions/checkout@v4
      with:
        path: phobos
        repository: dlang/phobos
        ref: ${{ steps.base_branch.outputs.branch }}
        persist-credentials: false


    ########################################
    #   Setting up the host C++ compiler   #
    ########################################
    - name: 'Linux: Install C++ compiler'
      if: runner.os == 'Linux'
      run: |
        set -eux
        sudo apt-get update
        apt_packages='${{ matrix.compiler }}'
        if [[ "$MODEL" == 32 ]]; then
          if [[ '${{ matrix.compiler }}' =~ ^g\+\+ ]]; then
            apt_packages+=" ${{ matrix.compiler }}-multilib"
          else
            apt_packages+=" g++-multilib"
          fi
        fi
        sudo apt-get install -y $apt_packages

    - name: 'Windows: Set up MSVC environment' # puts cl.exe in PATH etc.
      if: runner.os == 'Windows'
      uses: seanmiddleditch/gha-setup-vsdevenv@v4
      with:
        arch: ${{ matrix.model == '64' && 'x64' || 'x86' }}

    - name: 'Posix: Set up CC and CXX environment variables'
      if: runner.os != 'Windows'
      run: |
        set -eux
        if [[ '${{ runner.os }}' == Linux ]]; then
          compiler='${{ matrix.compiler }}'
          echo "CC=${compiler/g++/gcc}" >> $GITHUB_ENV
          echo "CXX=${compiler/clang/clang++}" >> $GITHUB_ENV
        elif [[ '${{ runner.os }}' == macOS ]]; then
          sudo xcode-select -switch /Applications/Xcode_${{ matrix.xcode }}.app
          echo "CC=cc" >> $GITHUB_ENV
          echo "CXX=c++" >> $GITHUB_ENV
        fi

    - name: Print used C/C++ compiler versions
      run: |
        set -eux
        if [[ '${{ runner.os }}' == Windows ]]; then
          which cl.exe
        else
          $CC --version
          $CXX --version
        fi

    ########################################
    #    Building DMD, druntime, Phobos    #
    ########################################
    - name: Build compiler & standard library
      run: |
        set -eux
        extraFlags=()
        if [[ '${{ matrix.os }}' == macos-14 ]]; then
          # DMD doesn't work on arm64 yet. Make LDC host compiler cross-compile
          # DMD to x86_64, and then use implicit Rosetta emulation.
          extraFlags=(HOST_DFLAGS="-mtriple=x86_64-apple-macos14")
        fi
        make -C dmd    -j$N "${extraFlags[@]}"
        make -C phobos -j$N

    ########################################
    #        Running the test suite        #
    ########################################
    - name: Run compiler C++ test suite
      run: ./dmd/compiler/test/run.d --environment runnable_cxx dshell/dll_cxx.d ${{ matrix.os == 'macos-14' && 'HOST_DMD="$PWD/dmd/generated/osx/release/64/dmd"' || '' }}

    - name: Run druntime C++ tests
      run: make -C dmd/druntime -j$N test/stdcpp/.run

    - name: 'Posix: Run C++ frontend unittests'
      if: runner.os != 'Windows' # not supported by build.d yet
      run: |
        set -eux
        extraFlags=()
        if [[ '${{ matrix.os }}' == macos-14 ]]; then
          extraFlags=(HOST_DMD=ldmd2 DFLAGS="-mtriple=x86_64-apple-macos14" CXXFLAGS="-arch x86_64")
        fi
        ./dmd/generated/build cxx-unittest "${extraFlags[@]}"