enable github check workflow

.bazelrc

@@ -23,4 +23,19 @@ build:verbose-clang-tidy --@bazel_clang_tidy//:clang_tidy_executable=//tools:ver
 build:clang-tidy --config=clang-tidy-base
 build:clang-tidy --@bazel_clang_tidy//:clang_tidy_executable=@llvm_toolchain//:clang-tidy
 
+coverage --combined_report=lcov
+coverage --strategy=CoverageReport=local
+
+# At least some of this is needed for the coverage tool to work.
+coverage --experimental_split_coverage_postprocessing
+coverage --experimental_fetch_all_coverage_outputs
+coverage --remote_download_outputs=all
+coverage --experimental_remote_download_regex=.*/((testlogs/.*/_coverage/.*)|coverage.dat$|_coverage/_coverage_report.dat$)
+
+# Not sure why it doesn't work with clang. Should be possible.
+coverage --extra_toolchains=//toolchain:gcc
+
+# Needed because our tests are in a different package than the code they test.
+coverage --instrumentation_filter='//...'
+
 try-import %workspace%/user.bazelrc

.github/workflows/check.yml

@@ -0,0 +1,126 @@
+name: check
+
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+    branches: [ "*" ]
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        toolchain: [gcc, clang]
+        feature: ['', asan, tsan, ubsan]
+
+    steps:
+    - uses: actions/checkout@v3
+
+    - name: mount bazel cache
+      uses: actions/cache@v3
+      with:
+        path: "~/.cache/bazel"
+        key: bazel-test-${{ matrix.toolchain }}-${{ matrix.feature }}
+
+    - name: install libtinfo5
+      # clang tools load libtinfo5 for color diagnostics but `ubuntu-latest`
+      # runners already have `libtinfo.so.6` installed. We just create a
+      # symlink since it's faster than installing libtinfo5.
+      # https://github.com/circleci/circleci-images/issues/430#issuecomment-522602495
+      run: |
+        sudo ln -s /lib/x86_64-linux-gnu/libtinfo.so.6 /lib/x86_64-linux-gnu/libtinfo.so.5
+
+    - run: |
+        bazel \
+          --bazelrc=.github/workflows/ci.bazelrc \
+          test \
+          --config=${{ matrix.toolchain }} \
+          --features=${{ matrix.feature }} \
+          //...
+
+  coverage:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v3
+
+    - name: mount bazel cache
+      uses: actions/cache@v3
+      with:
+        path: "~/.cache/bazel"
+        key: bazel-coverage
+
+    - name: install libtinfo5
+      # clang tools load libtinfo5 for color diagnostics but `ubuntu-latest`
+      # runners already have `libtinfo.so.6` installed. We just create a
+      # symlink since it's faster than installing libtinfo5.
+      # https://github.com/circleci/circleci-images/issues/430#issuecomment-522602495
+      run: |
+        sudo ln -s /lib/x86_64-linux-gnu/libtinfo.so.6 /lib/x86_64-linux-gnu/libtinfo.so.5
+
+    - run: |
+        bazel \
+          --bazelrc=.github/workflows/ci.bazelrc \
+          coverage \
+          //...
+
+    - uses: codecov/codecov-action@v3
+      with:
+        token: ${{ secrets.CODECOV_TOKEN }}
+        files: ./bazel-out/_coverage/_coverage_report.dat
+        fail_ci_if_error: true
+
+  build:
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        flag:
+          - '--config=clang-format'
+          - '--config=clang-tidy'
+          - '--config=verbose-clang-tidy'
+          - '--compilation_mode=opt'
+        exclude:
+          - flag: ${{ github.event_name == 'pull_request' && '--config=verbose-clang-tidy' || 'dummy' }}
+
+    steps:
+    - uses: actions/checkout@v3
+
+    - name: mount bazel cache
+      uses: actions/cache@v3
+      with:
+        path: "~/.cache/bazel"
+        key: bazel-build-${{ matrix.flag }}
+
+    - name: install libtinfo5
+      # clang tools load libtinfo5 for color diagnostics but `ubuntu-latest`
+      # runners already have `libtinfo.so.6` installed. We just create a
+      # symlink since it's faster than installing libtinfo5.
+      # https://github.com/circleci/circleci-images/issues/430#issuecomment-522602495
+      run: |
+        sudo ln -s /lib/x86_64-linux-gnu/libtinfo.so.6 /lib/x86_64-linux-gnu/libtinfo.so.5
+
+    - run: |
+        bazel \
+          --bazelrc=.github/workflows/ci.bazelrc \
+          build \
+          ${{ matrix.flag }} \
+          //...
+
+  buildifier:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v3
+
+    - name: mount bazel cache
+      uses: actions/cache@v3
+      with:
+        path: "~/.cache/bazel"
+        key: bazel-buildifier
+
+    - run: |
+        bazel \
+          --bazelrc=.github/workflows/ci.bazelrc \
+          run \
+          //:buildifier.check

.github/workflows/ci.bazelrc

@@ -0,0 +1,11 @@
+# This is from Bazel's former travis setup, to avoid blowing up the RAM usage.
+startup --host_jvm_args=-Xmx2500m
+
+build --show_timestamps
+build --announce_rc
+build --color=yes
+build --terminal_columns=120
+build --remote_download_minimal
+
+test --test_output=all
+test --test_verbose_timeout_warnings