ci-actions

Shared GitHub Actions for tanh-lab C++ CMake projects.

Actions

Action	Description
setup-cpp-build-tools	Install platform-specific C++ build tools (clang, ninja, etc.)
cmake-build	Configure and build a CMake project (supports presets and manual mode)
cmake-test	Run CTest (supports presets and manual mode)
clang-format-check	Check C++ source formatting with clang-format (fails on violations)
clang-tidy-check	Run clang-tidy on C++ sources (fails on any warning)
changed-files	List the files a pull request changes, from git alone (no token), and say whether a check should sweep everything instead

Usage

steps:
  - uses: actions/checkout@v4

  - uses: tanh-lab/ci-actions/setup-cpp-build-tools@main
    with:
      CLANG_VERSION: "20"  # optional, default: 20

  - uses: tanh-lab/ci-actions/cmake-build@main
    with:
      PRESET: desktop-debug  # or use BUILD_TYPE for manual mode

  - uses: tanh-lab/ci-actions/cmake-test@main
    with:
      PRESET: desktop-debug

  - uses: tanh-lab/ci-actions/clang-format-check@main
    with:
      SOURCES: "src/ include/"

  - uses: tanh-lab/ci-actions/clang-tidy-check@main
    with:
      SOURCES: "src/"
      PRESET: desktop-debug

Checking only what a pull request changes

clang-tidy-check sweeps SOURCES by default. With CHANGED_FILES_ONLY: "true" a pull_request run checks only the .cpp files the pull request changes, and every other event still sweeps (the merge queue; a workflow_dispatch run sweeps a branch by hand):

  - uses: tanh-lab/ci-actions/clang-tidy-check@v0.3.13
    with:
      SOURCES: "src/ test/"
      PRESET: desktop-debug
      CHANGED_FILES_ONLY: "true"
      # What changes tidy's own verdicts sweeps: the rule set, and the workflow
      # that pins the tool.
      FULL_SWEEP_PATTERN: '^\.clang-tidy$|^\.github/workflows/clang_tidy\.yml$'

The list comes from git: on a pull_request event actions/checkout leaves HEAD on GitHub's merge commit, and the diff against its first parent is what the pull request changes. No token and no API call; fetch-depth: 2 saves one fetch, the default depth works too. Every doubt sweeps: another event, a path matching the pattern, a checkout that is not that merge commit.

The trade: a header change does not widen the set, so what it breaks in a file the pull request did not touch shows in the next sweep, not on the pull request. Keep a sweeping run as the enforcement point (the merge queue).

Keep FULL_SWEEP_PATTERN narrow. It meets the pull request's whole diff on every push, not the last push, so a path that many pull requests touch sweeps them for their whole life: with CMakeLists.txt in it, every pull request that adds a source file sweeps on every push (anira's first pattern did exactly that).

changed-files is the same logic as its own action, for any other check:

  - uses: tanh-lab/ci-actions/changed-files@v0.3.13
    id: changed
    with:
      FULL_SWEEP_PATTERN: '^\.clang-format$'
  # steps.changed.outputs.sweep  'true' | 'false'
  # steps.changed.outputs.files  newline-separated paths, deleted ones included
  # steps.changed.outputs.reason one line for the log

Matrix naming convention

Actions use matrix.name for platform detection:

• Linux-x86_64
• macOS-x86_64
• macOS-arm64
• Windows-x86_64

Versioning

Consumers pin a release tag (uses: tanh-lab/ci-actions/<action>@v0.1.0) instead of @main. Changes are recorded in CHANGELOG.md; a breaking change updates the consumers (tanh-lib, anira) in the same motion.