Parallelize and workaround CI style checks (#1184)

We now do style checks in parallel to `cargo test` so that style
problems will fail fast.

Black-listed clippy 0.1.77 on x86_64-apple-darwin because it is known to
crash randomly.

Also added missing style checks for non-mock benchmarks.

Author: wks

Diff for: .github/scripts/ci-style.sh

@@ -13,36 +13,51 @@ if [[ $CLIPPY_VERSION == "clippy 0.1.72"* ]]; then
     export CARGO_INCREMENTAL=0
 fi
 
+if [[ $CLIPPY_VERSION == "clippy 0.1.77"* && $CARGO_BUILD_TARGET == "x86_64-apple-darwin" ]]; then
+    export SKIP_CLIPPY=1
+fi
+
 # --- Check main crate ---
 
-# check base
-cargo clippy
-# check all features
-for_all_features "cargo clippy"
-# check release
-for_all_features "cargo clippy --release"
-# check for tests
-for_all_features "cargo clippy --tests"
-
-# target-specific features
-if [[ $arch == "x86_64" && $os == "linux" ]]; then
-    cargo clippy --features perf_counter
-    cargo clippy --release --features perf_counter
-    cargo clippy --tests --features perf_counter
-fi
+if [[ $SKIP_CLIPPY == 1 ]]; then
+    echo "Skipping clippy version $CLIPPY_VERSION on $CARGO_BUILD_TARGET"
+else
+    # check base
+    cargo clippy
+    # check all features
+    for_all_features "cargo clippy"
+    # check release
+    for_all_features "cargo clippy --release"
+    # check for tests
+    for_all_features "cargo clippy --tests"
 
-# mock tests
-cargo clippy --features mock_test
-cargo clippy --features mock_test --tests
-cargo clippy --features mock_test --benches
+    # target-specific features
+    if [[ $arch == "x86_64" && $os == "linux" ]]; then
+        cargo clippy --features perf_counter
+        cargo clippy --release --features perf_counter
+        cargo clippy --tests --features perf_counter
+    fi
+
+    # mock tests
+    cargo clippy --features mock_test
+    cargo clippy --features mock_test --tests
+    cargo clippy --features mock_test --benches
+
+    # non-mock benchmarks
+    cargo clippy --features test_private --benches
+fi
 
 # --- Check auxiliary crate ---
 
 style_check_auxiliary_crate() {
     crate_path=$1
 
-    cargo clippy --manifest-path=$crate_path/Cargo.toml
-    cargo fmt --manifest-path=$crate_path/Cargo.toml -- --check
+    if [[ $SKIP_CLIPPY == 1 ]]; then
+        echo "Skipping clippy test for $crate_path"
+    else
+        cargo clippy --manifest-path=$crate_path/Cargo.toml
+        cargo fmt --manifest-path=$crate_path/Cargo.toml -- --check
+    fi
 }
 
 style_check_auxiliary_crate macros

Diff for: .github/workflows/merge-check.yml

@@ -11,7 +11,7 @@ env:
   # Ignore some actions for the merge check:
   # - This action itself
   # - Public API check, doc broken link check: we allow them to fail.
-  # - Minimal tests for stable Rust: we allow them to fail.
+  # - Minimal tests and style checks for stable Rust: we allow them to fail.
   # - Extended binding tests: it may take long to run. We don't want to wait for them.
   #   Note: The action name for openjdk tests is different due to the reused workflow.
   IGNORED_ACTIONS: |
@@ -23,6 +23,9 @@ env:
       "minimal-tests-core/x86_64-unknown-linux-gnu/stable",
       "minimal-tests-core/i686-unknown-linux-gnu/stable",
       "minimal-tests-core/x86_64-apple-darwin/stable",
+      "style-check/x86_64-unknown-linux-gnu/stable",
+      "style-check/i686-unknown-linux-gnu/stable",
+      "style-check/x86_64-apple-darwin/stable",
       "extended-tests-openjdk / test",
       "extended-tests-v8",
       "extended-tests-jikesrvm",

Diff for: .github/workflows/minimal-tests-core.yml

@@ -79,6 +79,49 @@ jobs:
       - name: Test
         run: ./.github/scripts/ci-test.sh
 
+  style-check:
+    needs: setup-test-matrix
+    strategy:
+      fail-fast: false
+      matrix:
+        target:
+          - { os: ubuntu-22.04, triple: x86_64-unknown-linux-gnu }
+          - { os: ubuntu-22.04, triple: i686-unknown-linux-gnu }
+          - { os: macos-12, triple: x86_64-apple-darwin }
+        rust: ${{ fromJson(needs.setup-test-matrix.outputs.rust )}}
+
+    name: style-check/${{ matrix.target.triple }}/${{ matrix.rust }}
+    runs-on: ${{ matrix.target.os }}
+
+    env:
+      # This determines the default target which cargo-build, cargo-test, etc. use.
+      CARGO_BUILD_TARGET: "${{ matrix.target.triple }}"
+
+    steps:
+      - uses: actions/checkout@v4
+      - name: Install Rust
+        run: |
+          # "rustup toolchain install" should always install the host toolchain,
+          # so we don't specify the triple.
+          rustup toolchain install ${{ matrix.rust }}
+          rustup override set ${{ matrix.rust }}
+
+          # Ensure we install the target support for the target we are testing for.
+          # This is especially important for i686-unknown-linux-gnu
+          # because it's different from the host.
+          rustup target add ${{ matrix.target.triple }}
+
+          rustup component add rustfmt clippy
+
+      # Show the Rust toolchain and target we are actually using
+      - run: rustup show
+      - run: cargo --version
+      - run: cargo rustc -- --print cfg
+
+      # Setup Environments
+      - name: Setup Environments
+        run: ./.github/scripts/ci-setup-${{ matrix.target.triple }}.sh
+
       # Style checks
       - name: Style checks
         run: ./.github/scripts/ci-style.sh

Diff for: benches/main.rs

@@ -8,13 +8,13 @@ pub mod mock_bench;
 #[cfg(all(not(feature = "mock_test"), feature = "test_private"))]
 pub mod regular_bench;
 
-pub fn bench_main(c: &mut Criterion) {
+pub fn bench_main(_c: &mut Criterion) {
     cfg_if::cfg_if! {
         if #[cfg(feature = "mock_test")] {
             // If the "mock_test" feature is enabled, we only run mock test.
-            mock_bench::bench(c);
+            mock_bench::bench(_c);
         } else if #[cfg(feature = "test_private")] {
-            regular_bench::bench(c);
+            regular_bench::bench(_c);
         } else {
             eprintln!("ERROR: Benchmarks in mmtk_core requires the test_priavte feature (implied by mock_test) to run.");
             eprintln!("  Rerun with `MMTK_BENCH=\"bench_name\" cargo bench --features mock_test` to run mock-test benchmarks.");