cmake.yml

# ─────────────────────────────────────────────────────────────────────────────
# CXXGraph – Comprehensive Build & Test Matrix
#
# Axes:
#   OS           Ubuntu 22.04 / 24.04 · macOS 13 (x86) / latest (arm64) · Windows
#   Compiler     GCC 12/13/14 · Clang 15/17/18 · Apple Clang · MSVC 2022 · Clang-CL
#   C++ Std      17 · 20
#   Build Type   Release · Debug · RelWithDebInfo
#   Par. Backend none (sequential) · TBB (std::execution) · OpenMP
# ─────────────────────────────────────────────────────────────────────────────
name: CMake Build & Test

on:
  push:
    branches: [master]
  pull_request:
    branches: [master]

permissions:
  contents: read

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

env:
  # Use ${{ github.workspace }} — evaluated by Actions before CMake ever runs,
  # producing a real absolute path.  Do NOT use ~ here: CMake's file(DOWNLOAD)
  # never expands tilde and will fail with "cannot open file for write".
  CPM_SOURCE_CACHE: ${{ github.workspace }}/.cache/cpm

jobs:
  build-and-test:
    name: ${{ matrix.name }}
    runs-on: ${{ matrix.os }}
    timeout-minutes: 45

    strategy:
      fail-fast: false
      matrix:
        include:
          # ╔══════════════════════════════════════════════════════════════╗
          # ║   UBUNTU · GCC · Sequential (no extra parallel library)     ║
          # ╚══════════════════════════════════════════════════════════════╝

          - name: "Ubuntu 22.04 · GCC 12 · C++17 · Release · Sequential"
            os: ubuntu-22.04
            cc: gcc-12
            cxx: g++-12
            build_type: Release
            cxx_std: 17
            extra_cmake: ""
            extra_apt: ""

          - name: "Ubuntu 22.04 · GCC 12 · C++17 · Debug · Sequential"
            os: ubuntu-22.04
            cc: gcc-12
            cxx: g++-12
            build_type: Debug
            cxx_std: 17
            extra_cmake: ""
            extra_apt: ""

          # ╔══════════════════════════════════════════════════════════════╗
          # ║   UBUNTU · GCC · TBB  (std::execution → oneTBB backend)    ║
          # ╚══════════════════════════════════════════════════════════════╝

          - name: "Ubuntu 22.04 · GCC 13 · C++17 · Release · TBB"
            os: ubuntu-22.04
            cc: gcc-13
            cxx: g++-13
            build_type: Release
            cxx_std: 17
            extra_cmake: "-DCMAKE_EXE_LINKER_FLAGS=-ltbb"
            extra_apt: "gcc-13 g++-13 libtbb-dev"

          - name: "Ubuntu 22.04 · GCC 13 · C++20 · Release · TBB"
            os: ubuntu-22.04
            cc: gcc-13
            cxx: g++-13
            build_type: Release
            cxx_std: 20
            extra_cmake: "-DCMAKE_EXE_LINKER_FLAGS=-ltbb"
            extra_apt: "gcc-13 g++-13 libtbb-dev"

          - name: "Ubuntu 24.04 · GCC 14 · C++17 · Release · TBB"
            os: ubuntu-24.04
            cc: gcc-14
            cxx: g++-14
            build_type: Release
            cxx_std: 17
            extra_cmake: "-DCMAKE_EXE_LINKER_FLAGS=-ltbb"
            extra_apt: "gcc-14 g++-14 libtbb-dev"

          - name: "Ubuntu 24.04 · GCC 14 · C++17 · RelWithDebInfo · TBB"
            os: ubuntu-24.04
            cc: gcc-14
            cxx: g++-14
            build_type: RelWithDebInfo
            cxx_std: 17
            extra_cmake: "-DCMAKE_EXE_LINKER_FLAGS=-ltbb"
            extra_apt: "gcc-14 g++-14 libtbb-dev"

          - name: "Ubuntu 24.04 · GCC 14 · C++20 · Release · TBB"
            os: ubuntu-24.04
            cc: gcc-14
            cxx: g++-14
            build_type: Release
            cxx_std: 20
            extra_cmake: "-DCMAKE_EXE_LINKER_FLAGS=-ltbb"
            extra_apt: "gcc-14 g++-14 libtbb-dev"

          # ╔══════════════════════════════════════════════════════════════╗
          # ║   UBUNTU · GCC · OpenMP  (-DCXXGRAPH_WITH_OPENMP + -fopenmp)║
          # ║   libgomp is bundled with GCC — no extra apt package needed ║
          # ╚══════════════════════════════════════════════════════════════╝

          - name: "Ubuntu 22.04 · GCC 13 · C++17 · Release · OpenMP"
            os: ubuntu-22.04
            cc: gcc-13
            cxx: g++-13
            build_type: Release
            cxx_std: 17
            extra_cmake: "-DCMAKE_CXX_FLAGS='-DCXXGRAPH_WITH_OPENMP -fopenmp' -DCMAKE_EXE_LINKER_FLAGS=-fopenmp"
            extra_apt: "gcc-13 g++-13"

          - name: "Ubuntu 24.04 · GCC 14 · C++17 · Release · OpenMP"
            os: ubuntu-24.04
            cc: gcc-14
            cxx: g++-14
            build_type: Release
            cxx_std: 17
            extra_cmake: "-DCMAKE_CXX_FLAGS='-DCXXGRAPH_WITH_OPENMP -fopenmp' -DCMAKE_EXE_LINKER_FLAGS=-fopenmp"
            extra_apt: "gcc-14 g++-14"

          - name: "Ubuntu 24.04 · GCC 14 · C++20 · Release · OpenMP"
            os: ubuntu-24.04
            cc: gcc-14
            cxx: g++-14
            build_type: Release
            cxx_std: 20
            extra_cmake: "-DCMAKE_CXX_FLAGS='-DCXXGRAPH_WITH_OPENMP -fopenmp' -DCMAKE_EXE_LINKER_FLAGS=-fopenmp"
            extra_apt: "gcc-14 g++-14"

          # ╔══════════════════════════════════════════════════════════════╗
          # ║   UBUNTU · CLANG · Sequential                               ║
          # ╚══════════════════════════════════════════════════════════════╝

          - name: "Ubuntu 22.04 · Clang 15 · C++17 · Release · Sequential"
            os: ubuntu-22.04
            cc: clang-15
            cxx: clang++-15
            build_type: Release
            cxx_std: 17
            extra_cmake: ""
            extra_apt: ""
            clang_ver: "15"

          - name: "Ubuntu 22.04 · Clang 15 · C++17 · Debug · Sequential"
            os: ubuntu-22.04
            cc: clang-15
            cxx: clang++-15
            build_type: Debug
            cxx_std: 17
            extra_cmake: ""
            extra_apt: ""
            clang_ver: "15"

          # ╔══════════════════════════════════════════════════════════════╗
          # ║   UBUNTU · CLANG · TBB                                      ║
          # ╚══════════════════════════════════════════════════════════════╝

          - name: "Ubuntu 24.04 · Clang 17 · C++17 · Release · TBB"
            os: ubuntu-24.04
            cc: clang-17
            cxx: clang++-17
            build_type: Release
            cxx_std: 17
            extra_cmake: "-DCMAKE_EXE_LINKER_FLAGS=-ltbb"
            extra_apt: "libtbb-dev"
            clang_ver: "17"

          - name: "Ubuntu 24.04 · Clang 18 · C++17 · Release · TBB"
            os: ubuntu-24.04
            cc: clang-18
            cxx: clang++-18
            build_type: Release
            cxx_std: 17
            extra_cmake: "-DCMAKE_EXE_LINKER_FLAGS=-ltbb"
            extra_apt: "libtbb-dev"
            clang_ver: "18"

          - name: "Ubuntu 24.04 · Clang 18 · C++20 · Release · TBB"
            os: ubuntu-24.04
            cc: clang-18
            cxx: clang++-18
            build_type: Release
            cxx_std: 20
            extra_cmake: "-DCMAKE_EXE_LINKER_FLAGS=-ltbb"
            extra_apt: "libtbb-dev"
            clang_ver: "18"

          - name: "Ubuntu 24.04 · Clang 18 · C++20 · Debug · TBB"
            os: ubuntu-24.04
            cc: clang-18
            cxx: clang++-18
            build_type: Debug
            cxx_std: 20
            extra_cmake: "-DCMAKE_EXE_LINKER_FLAGS=-ltbb"
            extra_apt: "libtbb-dev"
            clang_ver: "18"

          # ╔══════════════════════════════════════════════════════════════╗
          # ║   UBUNTU · CLANG · OpenMP                                   ║
          # ║   Clang needs libomp (not bundled unlike GCC's libgomp)    ║
          # ╚══════════════════════════════════════════════════════════════╝

          - name: "Ubuntu 24.04 · Clang 18 · C++17 · Release · OpenMP"
            os: ubuntu-24.04
            cc: clang-18
            cxx: clang++-18
            build_type: Release
            cxx_std: 17
            extra_cmake: "-DCMAKE_CXX_FLAGS='-DCXXGRAPH_WITH_OPENMP -fopenmp=libomp' -DCMAKE_EXE_LINKER_FLAGS=-fopenmp=libomp"
            extra_apt: "libomp-18-dev"
            clang_ver: "18"

          - name: "Ubuntu 24.04 · Clang 18 · C++20 · Release · OpenMP"
            os: ubuntu-24.04
            cc: clang-18
            cxx: clang++-18
            build_type: Release
            cxx_std: 20
            extra_cmake: "-DCMAKE_CXX_FLAGS='-DCXXGRAPH_WITH_OPENMP -fopenmp=libomp' -DCMAKE_EXE_LINKER_FLAGS=-fopenmp=libomp"
            extra_apt: "libomp-18-dev"
            clang_ver: "18"

          # ╔══════════════════════════════════════════════════════════════╗
          # ║   macOS · Apple Clang · Sequential                          ║
          # ╚══════════════════════════════════════════════════════════════╝

          - name: "macOS 13 (x86) · Apple Clang · C++17 · Release · Sequential"
            os: macos-13
            cc: clang
            cxx: clang++
            build_type: Release
            cxx_std: 17
            extra_cmake: ""
            extra_brew: ""

          - name: "macOS latest (arm64) · Apple Clang · C++17 · Release · Sequential"
            os: macos-latest
            cc: clang
            cxx: clang++
            build_type: Release
            cxx_std: 17
            extra_cmake: ""
            extra_brew: ""

          - name: "macOS latest (arm64) · Apple Clang · C++20 · Release · Sequential"
            os: macos-latest
            cc: clang
            cxx: clang++
            build_type: Release
            cxx_std: 20
            extra_cmake: ""
            extra_brew: ""

          # ╔══════════════════════════════════════════════════════════════╗
          # ║   macOS · Apple Clang · TBB (Homebrew oneTBB)               ║
          # ╚══════════════════════════════════════════════════════════════╝

          - name: "macOS latest (arm64) · Apple Clang · C++17 · Release · TBB"
            os: macos-latest
            cc: clang
            cxx: clang++
            build_type: Release
            cxx_std: 17
            extra_cmake: "-DCMAKE_EXE_LINKER_FLAGS=-ltbb -DCMAKE_PREFIX_PATH=/opt/homebrew"
            extra_brew: "tbb"

          - name: "macOS latest (arm64) · Apple Clang · C++20 · Release · TBB"
            os: macos-latest
            cc: clang
            cxx: clang++
            build_type: Release
            cxx_std: 20
            extra_cmake: "-DCMAKE_EXE_LINKER_FLAGS=-ltbb -DCMAKE_PREFIX_PATH=/opt/homebrew"
            extra_brew: "tbb"

          - name: "macOS 13 (x86) · Apple Clang · C++17 · Release · TBB"
            os: macos-13
            cc: clang
            cxx: clang++
            build_type: Release
            cxx_std: 17
            extra_cmake: "-DCMAKE_EXE_LINKER_FLAGS=-ltbb -DCMAKE_PREFIX_PATH=/usr/homebrew"
            extra_brew: "tbb"

          # ╔══════════════════════════════════════════════════════════════╗
          # ║   macOS · Apple Clang · OpenMP                              ║
          # ║   Apple Clang ships WITHOUT OpenMP — brew libomp required  ║
          # ║   arm64 prefix: /opt/homebrew   x86 prefix: /usr/local     ║
          # ╚══════════════════════════════════════════════════════════════╝

          - name: "macOS latest (arm64) · Apple Clang · C++17 · Release · OpenMP"
            os: macos-latest
            cc: clang
            cxx: clang++
            build_type: Release
            cxx_std: 17
            extra_cmake: >-
              -DCMAKE_CXX_FLAGS="-DCXXGRAPH_WITH_OPENMP -Xpreprocessor -fopenmp -I/opt/homebrew/opt/libomp/include"
              -DCMAKE_EXE_LINKER_FLAGS="-L/opt/homebrew/opt/libomp/lib -lomp"
            extra_brew: "libomp"

          - name: "macOS 13 (x86) · Apple Clang · C++17 · Release · OpenMP"
            os: macos-13
            cc: clang
            cxx: clang++
            build_type: Release
            cxx_std: 17
            extra_cmake: >-
              -DCMAKE_CXX_FLAGS="-DCXXGRAPH_WITH_OPENMP -Xpreprocessor -fopenmp -I/usr/local/opt/libomp/include"
              -DCMAKE_EXE_LINKER_FLAGS="-L/usr/local/opt/libomp/lib -lomp"
            extra_brew: "libomp"

          # ╔══════════════════════════════════════════════════════════════╗
          # ║   WINDOWS · MSVC 2022 · Sequential                          ║
          # ╚══════════════════════════════════════════════════════════════╝

          - name: "Windows · MSVC 2022 · C++17 · Release · Sequential"
            os: windows-latest
            build_type: Release
            cxx_std: 17
            extra_cmake: ""
            msvc: true

          - name: "Windows · MSVC 2022 · C++17 · Debug · Sequential"
            os: windows-latest
            build_type: Debug
            cxx_std: 17
            extra_cmake: ""
            msvc: true

          - name: "Windows · MSVC 2022 · C++20 · Release · Sequential"
            os: windows-latest
            build_type: Release
            cxx_std: 20
            extra_cmake: ""
            msvc: true

          # ╔══════════════════════════════════════════════════════════════╗
          # ║   WINDOWS · MSVC 2022 · OpenMP  (/openmp)                   ║
          # ║   MSVC ships OpenMP runtime vcomp — no extra install needed ║
          # ╚══════════════════════════════════════════════════════════════╝

          - name: "Windows · MSVC 2022 · C++17 · Release · OpenMP"
            os: windows-latest
            build_type: Release
            cxx_std: 17
            extra_cmake: "-DCMAKE_CXX_FLAGS='/DCXXGRAPH_WITH_OPENMP /openmp'"
            msvc: true

          - name: "Windows · MSVC 2022 · C++20 · Release · OpenMP"
            os: windows-latest
            build_type: Release
            cxx_std: 20
            extra_cmake: "-DCMAKE_CXX_FLAGS='/DCXXGRAPH_WITH_OPENMP /openmp'"
            msvc: true

          # ╔══════════════════════════════════════════════════════════════╗
          # ║   WINDOWS · Clang-CL · Sequential                           ║
          # ╚══════════════════════════════════════════════════════════════╝

          - name: "Windows · Clang-CL · C++17 · Release · Sequential"
            os: windows-latest
            build_type: Release
            cxx_std: 17
            extra_cmake: ""
            clang_cl: true

    # ─────────────────────────────────────────────────────────────────────
    steps:
      - name: Checkout
        uses: actions/checkout@v6
        with:
          fetch-depth: 1

      # ── Install GCC (Ubuntu) ──────────────────────────────────────────
      - name: Install GCC (Ubuntu)
        if: runner.os == 'Linux' && startsWith(matrix.cc, 'gcc')
        run: |
          sudo apt-get update -q
          sudo apt-get install -y --no-install-recommends ${{ matrix.cc }} ${{ matrix.cxx }}

      # ── Install Clang via LLVM script (Ubuntu) ────────────────────────
      - name: Install Clang (Ubuntu)
        if: runner.os == 'Linux' && startsWith(matrix.cc, 'clang') && matrix.clang_ver
        run: |
          sudo apt-get update -q
          wget -qO- https://apt.llvm.org/llvm.sh | sudo bash -s -- ${{ matrix.clang_ver }} all
          sudo apt-get install -y --no-install-recommends ${{ matrix.cc }} ${{ matrix.cxx }}

      # ── Extra apt packages (TBB, libomp, …) ──────────────────────────
      - name: Install extra apt packages
        if: runner.os == 'Linux' && matrix.extra_apt != ''
        run: |
          sudo apt-get update -q
          sudo apt-get install -y --no-install-recommends ${{ matrix.extra_apt }}

      # ── Extra Homebrew packages (TBB, libomp) ─────────────────────────
      - name: Install extra brew packages
        if: runner.os == 'macOS' && matrix.extra_brew != ''
        run: brew install ${{ matrix.extra_brew }}

      # ── Ninja (all platforms) ─────────────────────────────────────────
      - name: Install Ninja
        uses: seanmiddleditch/gha-setup-ninja@v6

      # ── ccache ────────────────────────────────────────────────────────
      - name: Set up ccache
        uses: hendrikmuhs/ccache-action@v1.2
        with:
          key: ${{ matrix.name }}-${{ github.sha }}
          restore-keys: ${{ matrix.name }}-
          max-size: 500M

      # ── CPM dependency cache ───────────────────────────────────────────
      # IMPORTANT: path must match CPM_SOURCE_CACHE exactly.
      # Tilde (~) is NOT safe here — use github.workspace for an absolute path.
      - name: Cache CPM packages
        uses: actions/cache@v5
        with:
          path: ${{ github.workspace }}/.cache/cpm
          key: cpm-${{ runner.os }}-${{ hashFiles('**/CMakeLists.txt') }}
          restore-keys: cpm-${{ runner.os }}-

      # ── Configure: Unix / macOS ───────────────────────────────────────
      - name: Configure CMake (Unix)
        if: runner.os != 'Windows'
        env:
          CC: ${{ matrix.cc }}
          CXX: ${{ matrix.cxx }}
        run: |
          cmake -B build \
            -G Ninja \
            -DCMAKE_BUILD_TYPE=${{ matrix.build_type }} \
            -DCMAKE_CXX_STANDARD=${{ matrix.cxx_std }} \
            -DCMAKE_CXX_STANDARD_REQUIRED=ON \
            -DCMAKE_CXX_EXTENSIONS=OFF \
            -DTEST=ON \
            -DCMAKE_CXX_COMPILER_LAUNCHER=ccache \
            -DCMAKE_C_COMPILER_LAUNCHER=ccache \
            -DCMAKE_EXPORT_COMPILE_COMMANDS=ON \
            ${{ matrix.extra_cmake }}

      # ── Configure: Windows MSVC ───────────────────────────────────────
      - name: Configure CMake (Windows MSVC)
        if: matrix.msvc == true
        run: |
          cmake -B build `
            -G "Visual Studio 17 2022" -A x64 `
            -DCMAKE_BUILD_TYPE=${{ matrix.build_type }} `
            -DCMAKE_CXX_STANDARD=${{ matrix.cxx_std }} `
            -DCMAKE_CXX_STANDARD_REQUIRED=ON `
            -DCMAKE_CXX_EXTENSIONS=OFF `
            -DTEST=ON `
            -Dgtest_disable_pthreads=ON `
            ${{ matrix.extra_cmake }}

      # ── Configure: Windows Clang-CL ───────────────────────────────────
      - name: Configure CMake (Windows Clang-CL)
        if: matrix.clang_cl == true
        run: |
          cmake -B build `
            -G "Visual Studio 17 2022" -A x64 -T ClangCL `
            -DCMAKE_BUILD_TYPE=${{ matrix.build_type }} `
            -DCMAKE_CXX_STANDARD=${{ matrix.cxx_std }} `
            -DCMAKE_CXX_STANDARD_REQUIRED=ON `
            -DCMAKE_CXX_EXTENSIONS=OFF `
            -DTEST=ON `
            -Dgtest_disable_pthreads=ON `
            ${{ matrix.extra_cmake }}

      # ── Build ─────────────────────────────────────────────────────────
      - name: Build
        run: cmake --build build --config ${{ matrix.build_type }} --parallel

      # ── Test ──────────────────────────────────────────────────────────
      - name: Test
        working-directory: build
        shell: bash
        run: |
          ctest \
            --build-config ${{ matrix.build_type }} \
            --output-on-failure \
            --parallel 4 \
            --timeout 120 \
            -T Test

      # ── Upload test result XMLs as artifacts ──────────────────────────
      - name: Upload test results
        if: always()
        uses: actions/upload-artifact@v7
        with:
          name: test-results-${{ matrix.name }}
          path: build/Testing/**/*.xml
          if-no-files-found: ignore
          retention-days: 14