.github/workflows/libcxx-benchmark-commit.yml

# This file defines a workflow that runs the libc++ benchmarks at the given commit.
# This workflow is intended to be triggered manually or via the Github API. As such,
# it requires several inputs that allow customizing its behavior.

name: "[libc++] Run benchmark suite against commit"
run-name: "[libc++] Run benchmark suite against ${{ inputs.commit }} on ${{ inputs.lnt-machine }}"

permissions:
  contents: read

on:
  workflow_dispatch:
    inputs:
      commit:
        description: 'The libc++ commit to benchmark'
        required: true
        type: string
      lnt-machine:
        description: 'The LNT machine to run the benchmarks on'
        required: true
        type: choice
        options:
          - macos-26.5-arm64
          - linux-x86_64
      benchmark-suite-version:
        description: 'The version of the benchmark suite to use (a LLVM monorepo SHA)'
        required: false
        type: string
        default: 0eefb2682bf8c04954c46e91916b5164d8424702
      filter:
        description: 'An optional filter to determine which benchmarks to run'
        required: false
        type: string
      submit-lnt:
        description: 'Whether to submit the results to LNT -- dry-run unless opted in'
        required: false
        type: boolean
        default: false
      lnt-url:
        description: 'The URL of the LNT instance to submit to'
        required: false
        type: string
        default: http://lnt.llvm.org

jobs:
  # Determine which configuration to run based on the `lnt-machine` input.
  select-machine:
    runs-on: ubuntu-24.04
    outputs:
      matrix: ${{ steps.select.outputs.matrix }}
    steps:
      - name: Select the configuration to benchmark on
        id: select
        uses: actions/github-script@3a2844b7e9c422d3c10d287c895573f7108da1b3 # v9.0.0
        env:
          LNT_MACHINE: ${{ inputs.lnt-machine }}
        with:
          script: |
            const MACHINES = [
              {
                'lnt-machine': 'macos-26.5-arm64',
                runner: ['self-hosted', 'macOS', 'ARM64', '26', '26.5'],
                cxx: 'clang++',
                'running-on': 'macos',
                'xcode-version': '26.5',
              },
              {
                'lnt-machine': 'linux-x86_64',
                runner: 'llvm-premerge-libcxx-runners',
                cxx: 'clang++-22',
                'running-on': 'linux',
              },
            ];

            const requested = process.env.LNT_MACHINE;
            const selected = MACHINES.filter(m => m['lnt-machine'] === requested);
            if (selected.length === 0) {
              const known = MACHINES.map(m => m['lnt-machine']).join(', ');
              core.setFailed(`Unknown LNT machine '${requested}' (known machines: ${known})`);
              return;
            }

            core.setOutput('matrix', JSON.stringify(selected));

  run-benchmarks:
    needs:
      - select-machine
    strategy:
      matrix:
        include: ${{ fromJSON(needs.select-machine.outputs.matrix) }}
      fail-fast: false
    runs-on: ${{ matrix.runner }}
    env:
      COMPILER: ${{ matrix.cxx }}
    steps:
      - name: Checkout the LLVM monorepo
        uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
        with:
          persist-credentials: false
          # We benchmark arbitrary historical commits, which requires the full history to be available.
          fetch-depth: 0
          fetch-tags: true

      - name: Install Python
        if: ${{ matrix.running-on == 'linux' }} # installed via Homebrew on macOS
        uses: actions/setup-python@ece7cb06caefa5fff74198d8649806c4678c61a1 # v6.3.0
        with:
          python-version: '3.14'

      - name: Select Xcode
        if: ${{ matrix.running-on == 'macos' }}
        run: echo "DEVELOPER_DIR=/Applications/Xcode_${{ matrix.xcode-version }}.app/Contents/Developer" >> $GITHUB_ENV

      - name: Install dependencies via Homebrew
        if: ${{ matrix.running-on == 'macos' }}
        run: |
          brew update
          brew install ninja cmake python@3.14
          echo "$(brew --prefix python@3.14)/bin" >> "$GITHUB_PATH"

      - name: Diagnose tools in use
        run: |
          cmake --version
          ninja --version
          "${COMPILER}" --version
          python3 --version

      - name: Run the benchmarks
        env:
          COMMIT: ${{ inputs.commit }}
          BENCHMARK_SUITE_VERSION: ${{ inputs.benchmark-suite-version }}
          FILTER: ${{ inputs.filter }}
          LNT_MACHINE: ${{ matrix.lnt-machine }}
        run: |
          filter_arg=()
          if [ -n "${FILTER}" ]; then
            filter_arg=(--filter "${FILTER}")
          fi
          libcxx/utils/ci/lnt/run-benchmarks                            \
            --test-suite-commit "${BENCHMARK_SUITE_VERSION}"            \
            --machine "${LNT_MACHINE}"                                  \
            --compiler "${COMPILER}"                                    \
            --benchmark-commit "${COMMIT}"                              \
            "${filter_arg[@]}"                                          \
            --output "${COMMIT}.json"

          cat "${COMMIT}.json"

      - name: Submit to LNT
        if: ${{ inputs.submit-lnt }}
        env:
          COMMIT: ${{ inputs.commit }}
          LNT_URL: ${{ inputs.lnt-url }}
        run: |
          libcxx/utils/ci/lnt/submit-benchmarks             \
            --lnt-url "${LNT_URL}"                          \
            --test-suite libcxx                             \
            "${COMMIT}.json"