[libc-commits] [libc] [llvm] Implement Automated Line and MC/DC Coverage CI Workflows (PR #219165)

[Aiden Grossman via libc-commits]

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@@ -0,0 +1,143 @@
+name: Libc Full Codebase Coverage
+
+permissions:
+  contents: write # Required to publish live HTML dashboard to gh-pages branch
+
+env:
+  FORCE_JAVASCRIPT_ACTIONS_TO_NODE24: 'true'
+
+on:
+  # Daily overnight run at 02:00 UTC
+  schedule:
+    - cron: '0 2 * * *'
+
+  # Allow manual on-demand execution from GitHub Actions UI
+  workflow_dispatch:
+
+  # Trigger on pushes to main / libc-coverage-ci-bots / post-commit-bot
+  push:
+    branches:
+      - main
+      - libc-coverage-ci-bots
+      - post-commit-bot
+    paths:
+      - 'libc/**'
+      - '.github/workflows/libc-full-coverage.yml'
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  full-coverage:
+    timeout-minutes: 60
+    name: libc-full-coverage
+    runs-on: ubuntu-24.04
+    container:
+      image: ghcr.io/llvm/libc-ubuntu-24.04:latest at sha256:8fee4c9ce5a1fd095686593cd36e032c48a31b6ae575378c82accd1d86a08d59
+      options: --privileged
+    defaults:
+      run:
+        shell: bash
+    steps:
+    - name: Checkout Code
+      uses: actions/checkout at v4
+      with:
+        fetch-depth: 1
+        persist-credentials: false
+
+    - name: Setup Compiler Cache (sccache)
+      uses: hendrikmuhs/ccache-action at v1.2.23
+      with:
+        max-size: 1G
+        key: libc_coverage_unified_v2_x86_64
+        variant: sccache
+
+    - name: Configure CMake
+      run: |
+        echo "=== [STAGE 1/4] Starting CMake Configuration at $(date -u '+%Y-%m-%d %H:%M:%S UTC') ==="
+        START_TIME=$(date +%s)
+
+        export CMAKE_FLAGS="
+          -G Ninja
+          -S runtimes
+          -B build-cov
+          -DCMAKE_C_COMPILER=clang-23
+          -DCMAKE_CXX_COMPILER=clang++-23
+          -DCMAKE_BUILD_TYPE=Debug
+          -DCMAKE_C_COMPILER_LAUNCHER=sccache
+          -DCMAKE_CXX_COMPILER_LAUNCHER=sccache
+          -DLLVM_USE_LINKER=lld-23
+          -DLLVM_ENABLE_RUNTIMES=libc
+          -DLLVM_LIBC_FULL_BUILD=ON
+          -DLIBC_ENABLE_COVERAGE=ON
+          -DLIBC_TEST_UNIT_TEST_ONLY=ON
+          -DLIBC_TEST_SKIP_DEATH_TESTS=ON
+          -DLIBC_TEST_SKIP_SHARED_TESTS=ON
+        "
+        cmake $CMAKE_FLAGS
+
+        END_TIME=$(date +%s)
+        echo "=== [STAGE 1/4] CMake Configuration Completed in $((END_TIME - START_TIME))s ==="
+
+    - name: Run Full Codebase Unit Tests
+      run: |
+        echo "=== [STAGE 2/4] Running Full Unit Test Suite at $(date -u '+%Y-%m-%d %H:%M:%S UTC') ==="
+        START_TIME=$(date +%s)
+
+        export LLVM_PROFILE_FILE="libc_cov_%p.profraw"
+        ninja -k 0 -C build-cov libc-unit-tests || true
+
+        END_TIME=$(date +%s)
+        echo "=== [STAGE 2/4] libc-unit-tests Completed in $((END_TIME - START_TIME))s ==="
+
+    - name: Merge Profiles
+      run: |
+        echo "=== [STAGE 3/4] Merging Raw Profiles at $(date -u '+%Y-%m-%d %H:%M:%S UTC') ==="
+        find . build-cov -name "libc_cov_*.profraw" > profraw_list.txt
+        NUM_PROFS=$(wc -l < profraw_list.txt || echo 0)
+        echo "[LOG] Discovered $NUM_PROFS raw profile data files."
+        llvm-profdata-23 merge -sparse --input-files=profraw_list.txt -o libc_full.profdata
+        echo "[LOG] Merged full codebase profile into libc_full.profdata."
+
+    - name: Generate Reports and Summary
+      env:
+        COMMIT_SHA: ${{ github.sha }}
+        BRANCH_REF: ${{ github.ref_name }}
+      run: |
+        echo "=== [STAGE 4/4] Generating Full Codebase Coverage Reports at $(date -u '+%Y-%m-%d %H:%M:%S UTC') ==="
+        EXECUTABLES=($(find build-cov -type f -executable -name "*__build__"))
+        OBJECTS=("${EXECUTABLES[@]:1}")
+        OBJECTS=("${OBJECTS[@]/#/-object=}")
+
+        echo "[LOG] Exporting coverage data across ${#EXECUTABLES[@]} test binaries."
+
+        # 1. Generate JSON export for Full Coverage Analyzer
+        llvm-cov-23 export -format=text -instr-profile=libc_full.profdata "${EXECUTABLES[0]}" "${OBJECTS[@]}" > coverage.json
+
+        # 2. Generate HTML Coverage Report with directory hierarchy and branch tracking
+        llvm-cov-23 show -format=html \
+          -output-dir=coverage_html \
+          -instr-profile=libc_full.profdata \
+          "${EXECUTABLES[0]}" "${OBJECTS[@]}" \
+          --show-directory-coverage \
+          --show-branches=count \
+          --compilation-dir=. \
+          --path-equivalence="$GITHUB_WORKSPACE,." \
+          -ignore-filename-regex=".*(test|utils).*"
+        touch coverage_html/.nojekyll
+
+        # 3. Run Codebase Coverage Analyzer
+        PYTHONPATH="libc/utils/coverage" python3 libc/utils/coverage/codebase_coverage.py coverage.json "$COMMIT_SHA" "$BRANCH_REF" >> $GITHUB_STEP_SUMMARY
+        echo "[LOG] Post-commit summary report written to GITHUB_STEP_SUMMARY."
+
+    - name: Deploy Coverage Dashboard to GitHub Pages
+      if: github.repository != 'llvm/llvm-project'
----------------
boomanaiden154 wrote:

We need a better solution than just using the GH Pages branch of the monorepo. For now we should probably just upload the report as an artifact.

https://github.com/llvm/llvm-project/pull/219165