pull_request.yml

name: Pull request

permissions:
  contents: read

on:
  pull_request:
    types: [opened, reopened, synchronize]

jobs:
  tests:
    name: Test
    uses: swiftlang/github-workflows/.github/workflows/swift_package_test.yml@main
    with:
      linux_exclude_swift_versions: '[{"swift_version": "5.9"}, {"swift_version": "5.10"}, {"swift_version": "6.0"}, {"swift_version": "6.1"}, {"swift_version": "6.2"}]'
      enable_windows_checks: false
      enable_macos_checks: false
      enable_macos_swiftly_checks: true
  soundness:
    name: Soundness
    uses: swiftlang/github-workflows/.github/workflows/soundness.yml@main
    with:
      license_header_check_project_name: "Swift.org"
      unacceptable_language_check_enabled: false
      format_check_enabled: false
  bench:
    name: Benchmark
    runs-on: ubuntu-latest
    env:
      BUILD_CMD: swift build -c release
      BENCH_CMD: .build/release/RegexBenchmark
      BASELINE_FILE: benchmark-baseline
      MAIN_FILE: benchmark-main
      COMPARE_FILE: benchmark-pr
      COMPARE_OUT_FILE: benchmark-results.txt
    steps:
      - name: Check out baseline branch
        uses: actions/checkout@v7
        with:
          ref: ${{ github.event.pull_request.base.sha }}
          path: base
          fetch-depth: 0
      - name: Build baseline branch
        working-directory: base
        run: |
          set -euo pipefail
          eval "$BUILD_CMD"
      - name: Run baseline benchmark
        working-directory: base
        run: |
          set -euo pipefail
          eval "$BENCH_CMD --save $RUNNER_TEMP/$BASELINE_FILE"
          test -s "$RUNNER_TEMP/$BASELINE_FILE" || { echo "Baseline not created at $BASELINE_FILE"; exit 1; }
      - name: Check out main branch
        if: ${{ github.event.pull_request.base.ref != 'main' }}
        uses: actions/checkout@v7
        with:
          ref: main
          path: main-branch
          fetch-depth: 0
      - name: Build main branch
        if: ${{ github.event.pull_request.base.ref != 'main' }}
        working-directory: main-branch
        run: |
          set -euo pipefail
          eval "$BUILD_CMD"
      - name: Run main benchmark
        if: ${{ github.event.pull_request.base.ref != 'main' }}
        working-directory: main-branch
        run: |
          set -euo pipefail
          eval "$BENCH_CMD --save $RUNNER_TEMP/$MAIN_FILE"
          test -s "$RUNNER_TEMP/$MAIN_FILE" || { echo "Baseline (main) not created at $MAIN_FILE"; exit 1; }
      - name: Check out PR branch
        uses: actions/checkout@v7
        with:
          ref: ${{ github.event.pull_request.head.sha }}
          path: pr
          fetch-depth: 0
      - name: Build PR branch
        working-directory: pr
        run: |
          set -euo pipefail
          eval "$BUILD_CMD"
      - name: Run PR benchmark
        working-directory: pr
        run: |
          set -euo pipefail
          eval "$BENCH_CMD --save $RUNNER_TEMP/$COMPARE_FILE"
          test -s "$RUNNER_TEMP/$COMPARE_FILE" || { echo "Comparison not created at $COMPARE_FILE"; exit 1; }
          eval "$BENCH_CMD --compare $RUNNER_TEMP/$BASELINE_FILE" | tee "$RUNNER_TEMP/$COMPARE_OUT_FILE"
      - name: 📊 Compare benchmarks with base
        working-directory: pr
        run: |
          set -euo pipefail
          eval "$BENCH_CMD --load $RUNNER_TEMP/$COMPARE_FILE --compare $RUNNER_TEMP/$BASELINE_FILE --compare-compile-time $RUNNER_TEMP/$BASELINE_FILE" | tee "$RUNNER_TEMP/$COMPARE_OUT_FILE"
      - name: 📊 Compare benchmarks with `main`
        if: ${{ github.event.pull_request.base.ref != 'main' }}
        working-directory: pr
        run: |
          set -euo pipefail
          eval "$BENCH_CMD --load $RUNNER_TEMP/$COMPARE_FILE --compare $RUNNER_TEMP/$MAIN_FILE --compare-compile-time $RUNNER_TEMP/$MAIN_FILE"
      - name: Upload benchmark artifacts
        uses: actions/upload-artifact@v7
        with:
          name: benchmark-results
          path: |
            ${{ runner.temp }}/${{ env.BASELINE_FILE }}
            ${{ runner.temp }}/${{ env.COMPARE_FILE }}
            ${{ runner.temp }}/${{ env.COMPARE_OUT_FILE }}
  crossrepo:
    name: Cross-Repo Validation
    runs-on: ubuntu-latest
    container:
      image: swift:6.3-jammy
    steps:
      - name: Checkout repo
        uses: actions/checkout@v7
      - name: Install apt dependencies
        run: apt-get -qq update && apt-get -qq -y install curl ninja-build
      - name: Install CMake 3.30.2
        run: |
          ARCH=`uname -m`
          curl -sL https://github.com/Kitware/CMake/releases/download/v3.30.2/cmake-3.30.2-linux-$ARCH.tar.gz -O
          tar xzf cmake-3.30.2-linux-$ARCH.tar.gz
          export PATH="`pwd`/cmake-3.30.2-linux-$ARCH/bin:$PATH"
          echo "PATH=$PATH" >> $GITHUB_ENV
          cmake --version
      - name: Compare CMakeLists.txt against swiftlang/swift/Runtimes/Supplemental
        id: compare
        env:
          UPSTREAM_DIR: https://raw.githubusercontent.com/swiftlang/swift/refs/heads/main/Runtimes/Supplemental/StringProcessing
          MODULES: _StringProcessing _RegexParser
        shell: bash
        run: |
          set -u

          # `-f` so a file moving upstream reports a fetch error rather than
          # diffing against a 404 page.
          for module in $MODULES; do
            if ! curl -fsSL "$UPSTREAM_DIR/$module/CMakeLists.txt" \
                 -o "upstream-$module-CMakeLists.txt"; then
              echo "result=fetch-failed" >> "$GITHUB_OUTPUT"
              echo "Could not fetch $module/CMakeLists.txt from swiftlang/swift."
              exit 1
            fi
          done

          : > "$RUNNER_TEMP/cmake-diff.txt"
          status=0
          for module in $MODULES; do
            if ! diff -u \
                 --label "swiftlang/swift: Runtimes/Supplemental/StringProcessing/$module/CMakeLists.txt" \
                 --label "this repo:       Sources/$module/CMakeLists.txt" \
                 "upstream-$module-CMakeLists.txt" \
                 "Sources/$module/CMakeLists.txt" \
                 >> "$RUNNER_TEMP/cmake-diff.txt"; then
              status=1
            fi
          done

          if [ "$status" -eq 0 ]; then
            echo "result=match" >> "$GITHUB_OUTPUT"
            echo "Both CMakeLists.txt files match swiftlang/swift."
          else
            echo "result=differs" >> "$GITHUB_OUTPUT"
            cat "$RUNNER_TEMP/cmake-diff.txt"
          fi
          exit "$status"
      - name: Configure CMake
        id: configure
        if: ${{ !cancelled() }}
        run: cmake -G Ninja -S Sources -B build -DCMAKE_BUILD_TYPE=Release
      - name: Build
        id: build
        if: ${{ !cancelled() }}
        run: cmake --build build
      - name: Verdict
        if: ${{ always() }}
        env:
          COMPARE_OUTCOME: ${{ steps.compare.outcome }}
          COMPARE_RESULT: ${{ steps.compare.outputs.result }}
          CONFIGURE_OUTCOME: ${{ steps.configure.outcome }}
          BUILD_OUTCOME: ${{ steps.build.outcome }}
        shell: bash
        run: |
          set -u

          # Report to the step log and to the job summary page.
          emit() { printf '%s\n' "$@" | tee -a "$GITHUB_STEP_SUMMARY"; }

          failed=0

          # --- the CMake build ---
          if [ "$CONFIGURE_OUTCOME" = failure ] || [ "$BUILD_OUTCOME" = failure ]; then
            failed=1
            if [ "$CONFIGURE_OUTCOME" = failure ]; then
              stage='CMake configuration'
            else
              stage='CMake build'
            fi
            emit \
              "## :x: $stage failed" \
              '' \
              'The CMake build of `_RegexParser` and `_StringProcessing` is broken.' \
              "See the \"$stage\" step above for the output." \
              ''
          fi

          # --- the comparison against swiftlang/swift ---
          case "${COMPARE_RESULT:-}" in
            match)
              ;;
            differs)
              failed=1
              emit \
                '## :warning: `CMakeLists.txt` differs from swiftlang/swift' \
                '' \
                '<details><summary>Diff to apply upstream</summary>' \
                '' \
                '```diff'
              tee -a "$GITHUB_STEP_SUMMARY" < "$RUNNER_TEMP/cmake-diff.txt"
              emit '```' '' '</details>' ''
              ;;
            fetch-failed)
              failed=1
              emit \
                '## :x: Could not fetch the upstream `CMakeLists.txt` files'
              ;;
            *)
              failed=1
              emit \
                "## :x: Comparison did not complete (outcome: ${COMPARE_OUTCOME:-unknown})"
              ;;
          esac

          # --- all clear ---
          if [ "$failed" -eq 0 ]; then
            emit \
              '## :white_check_mark: Cross-repo validation passed'
          fi

          exit "$failed"
  required:
    name: Required
    runs-on: ubuntu-latest
    needs:
      - tests
      - soundness
      - bench
    if: always()  # Runs even if previous jobs fail so it can evaluate them
    steps:
      - name: Install required tools
        run: |
          sudo apt-get update
          sudo apt-get install -y --no-install-recommends coreutils jq
      - name: Check upstream job statuses
        env:
          NEEDS_JSON: ${{ toJSON(needs) }}
        run: |
          failed=$(printf '%s' "$NEEDS_JSON" | jq -r 'to_entries | map(select(.value.result != "success")) | .[] | "\(.key): \(.value.result)"')
          if [ -n "$failed" ]; then
            echo "The following required jobs did not succeed:"
            printf '%s\n' "$failed"
            exit 1
          fi
          echo "All required jobs succeeded."