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: Benchmark libc++ commit

permissions:
  contents: read

on:
  # TODO: Support dispatching only to selected configurations.
  workflow_dispatch:
    inputs:
      commit:
        description: 'The libc++ commit to benchmark'
        required: true
        type: string
      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:
  run-benchmarks:
    strategy:
      matrix:
        include:
          - lnt-machine: macos-26.5-arm64
            runner: ["self-hosted", "macOS", "ARM64", "26", "26.5"]
            cxx: clang++
            install-python: false
            install-macos-dependencies: true
          - lnt-machine: linux-x86_64
            runner: llvm-premerge-libcxx-runners
            cxx: clang++-22
            install-python: true
            install-macos-dependencies: false
      fail-fast: false
    runs-on: ${{ matrix.runner }}
    steps:
      - name: Checkout the LLVM monorepo
        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
        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.install-python }}
        uses: actions/setup-python@a309ff8b426b58ec0e2a45f0f869d46889d02405 # v6.2.0
        with:
          python-version: '3.14'

      - name: Install Ninja and CMake
        if: ${{ matrix.install-macos-dependencies }}
        run: |
          brew install ninja cmake

      - name: Diagnose tools in use
        run: |
          cmake --version
          ninja --version
          ${{ matrix.cxx }} --version

      - name: Run the benchmarks
        env:
          COMMIT: ${{ inputs.commit }}
          BENCHMARK_SUITE_VERSION: ${{ inputs.benchmark-suite-version }}
          FILTER: ${{ inputs.filter }}
        run: |
          filter_arg=()
          if [ -n "${FILTER}" ]; then
            filter_arg=(--filter "${FILTER}")
          fi
          libcxx/utils/ci/lnt/run-benchmarks                            \
            --test-suite-commit "${BENCHMARK_SUITE_VERSION}"            \
            --machine ${{ matrix.lnt-machine }}                         \
            --compiler ${{ matrix.cxx }}                                \
            --benchmark-commit "${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 libcxx2                            \
            "${COMMIT}.json"