name: Style Checker

# Runs my simple style(9) checker on pull requests.

on:
  pull_request: # maybe pull_request_target
    branches: [ main ]
    types: [ opened, reopened, edited, synchronize ]
    paths: [ '**.S', '**.c', '**.cc', '**.cpp', '**.h', '**.hh', '**.hpp' ]

permissions:
  contents: read

jobs:
  build:
    name: Style Checker
    runs-on: ubuntu-latest
    steps:
      # Unfortunately there doesn't seem to be a way to
      # do this without an extra step.
      - name: Get depth
        run: |
          echo "DEPTH=$(( ${{ github.event.pull_request.commits }} + 1 ))" >> $GITHUB_ENV
      - name: checkout
        uses: actions/checkout@v4
        with:
          fetch-depth: ${{ env.DEPTH }}
          ref: ${{ github.event.pull_request.head.sha }}
      - name: Install packages
        run: |
          sudo apt-get update --quiet || true
          sudo apt-get -yq --no-install-suggests --no-install-recommends install perl
      - name: Run checker
        run: |
          sha=$(git rev-parse HEAD~${{ github.event.pull_request.commits }})
          tools/build/checkstyle9.pl --github ${sha}..${{ github.event.pull_request.head.sha }}