name: clang-tidy

# Runs clang-tidy, with the checks in .clang-tidy, over the C++ lines a pull
# request changes (scripts/clang_tidy_diff.py). The compile database is
# configured without the precompiled header, so code that only builds because
# the PCH supplied an include fails here.
#
# No paths filter: the job is a required check, and a workflow skipped by a
# paths filter leaves a required check pending forever. A PR with no C++
# changes finishes after the first step.
on:
  pull_request:
    branches:
      - main
      - release/*

permissions:
  contents: read

concurrency:
  group: ${{ github.workflow }}-${{ github.event.pull_request.number }}
  cancel-in-progress: true

jobs:
  clang_tidy:
    # Branch protection requires this check by name. Renaming the job disables
    # that gate.
    name: clang-tidy
    runs-on: ${{ vars.SELF_HOSTED && 'orca-lnx-server' || 'ubuntu-24.04' }}
    steps:
      - name: Checkout
        uses: actions/checkout@v7
        with:
          lfs: 'false'
          # The PR merge commit plus its first parent, the base it is diffed against.
          fetch-depth: 2

      - name: Look for changed C++ files
        id: changes
        run: |
          if git -c core.quotePath=false diff --name-only HEAD^1 -- src tests | grep -qE '\.(cpp|cc|cxx|hpp|h|hxx)$'; then
            echo "cpp=true" >> "$GITHUB_OUTPUT"
          else
            echo "No C++ changes under src/ or tests/."
          fi

      # Parsing needs the dependency headers, not a build of this PR's deps/, so
      # a PR that changes deps/ falls back to the newest cache main has.
      - name: Restore cached deps
        if: steps.changes.outputs.cpp == 'true'
        uses: actions/cache/restore@v6
        with:
          path: ${{ github.workspace }}/deps/build/OrcaSlicer_dep
          key: linux-clang-cache-orcaslicer_deps-build-${{ hashFiles('deps/**') }}
          restore-keys: linux-clang-cache-orcaslicer_deps-build-
          fail-on-cache-miss: true

      - name: Apt-Install Dependencies
        if: steps.changes.outputs.cpp == 'true' && !vars.SELF_HOSTED
        uses: ./.github/actions/apt-install-deps

      - name: Install clang-tidy
        if: steps.changes.outputs.cpp == 'true'
        run: |
          python3 -m venv "$RUNNER_TEMP/clang-tidy"
          "$RUNNER_TEMP/clang-tidy/bin/pip" install --quiet -r scripts/clang_tidy_requirements.txt

      # DEP_BUILD_DIR is named outright: CMake would otherwise derive it from the build
      # directory's name and look for the dependencies in deps/build-tidy.
      - name: Configure without the precompiled header
        if: steps.changes.outputs.cpp == 'true'
        run: >
          cmake -S . -B build-tidy -G Ninja
          -DCMAKE_BUILD_TYPE=Release
          -DCMAKE_C_COMPILER=clang -DCMAKE_CXX_COMPILER=clang++
          -DCMAKE_EXPORT_COMPILE_COMMANDS=ON
          -DSLIC3R_PCH=OFF -DORCA_TOOLS=ON -DBUILD_TESTS=ON
          -DDEP_BUILD_DIR=${{ github.workspace }}/deps/build

      # The one header the build generates rather than the configure.
      - name: Generate git_commit_hash.h
        if: steps.changes.outputs.cpp == 'true'
        run: cmake --build build-tidy --target git_commit_hash_header

      - name: Run clang-tidy on the changed lines
        if: steps.changes.outputs.cpp == 'true'
        run: >
          python3 scripts/clang_tidy_diff.py -p build-tidy --base HEAD^1
          --clang-tidy "$RUNNER_TEMP/clang-tidy/bin/clang-tidy" -j "$(nproc)"