carbon-lang/.github/workflows/tests.yaml

# Part of the Carbon Language project, under the Apache License v2.0 with LLVM
# Exceptions. See /LICENSE for license information.
# SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception

name: test

on:
  push:
    branches: [trunk]
    paths:
      # Conservatively run the tests. However, skip them if the only paths in
      # the pull request match files that we know don't impact the build.
      - '**'
      - '!**/*.md'
      - '!LICENSE'
      - '!CODEOWNERS'
      - '!.git*'
  pull_request:
    paths:
      # Conservatively run the tests. However, skip them if the only paths in
      # the pull request match files that we know don't impact the build.
      - '**'
      - '!**/*.md'
      - '!LICENSE'
      - '!CODEOWNERS'
      - '!.git*'

jobs:
  test:
    strategy:
      matrix:
        os: [ubuntu-latest, macos-latest]
        build_mode: [fastbuild, opt]
    runs-on: ${{ matrix.os }}
    steps:
      - name: Create environment variables
        run: |
          echo "BAZEL_DISK_CACHE_PATH=$HOME/.cache/carbon-lang-build-cache" >> $GITHUB_ENV

      - name: Checkout
        uses: actions/checkout@v2
        with:
          submodules: true

      # Setup Python and related tools.
      - uses: actions/setup-python@v2
        with:
          # Match the min version listed in docs/project/contribution_tools.md
          python-version: '3.6'

      # On macOS we need Go and to use it to install Bazelisk.
      - uses: actions/setup-go@v2
        if: matrix.os == 'macos-latest'
      - name: Install bazelisk
        if: matrix.os == 'macos-latest'
        run: |
          go get github.com/bazelbuild/bazelisk
          echo "$(go env GOPATH)/bin" >> $GITHUB_PATH

      # Setup to the latest LLVM and Clang release on Linux runners.
      #
      # Ideally we would use the pre-installed versions in the image, but the
      # debian packages for LLVM-12 are broken due to several bugs:
      # https://bugs.llvm.org/show_bug.cgi?id=43604
      # https://bugs.llvm.org/show_bug.cgi?id=46321
      #
      # For now, we rely on Homebrew to manage installing a correctly built
      # toolchain. We also take some care to be as resilient as possible to
      # issues fetching and installing the toolchain.
      - name: Setup LLVM and Clang on Ubuntu
        if: matrix.os == 'ubuntu-latest'
        run: |
          brew update
          brew install --force-bottle --only-dependencies llvm
          brew install --force-bottle --force --verbose llvm
          brew info llvm
          brew config
          echo "$(brew --prefix llvm)/bin" >> $GITHUB_PATH

      # Just add the Homebrew installed LLVM to the path on macOS, the image has
      # LLVM-12 pre-installed.
      - name: Setup LLVM and Clang on macOS
        if: matrix.os == 'macos-latest'
        run: |
          echo "$(brew --prefix llvm)/bin" >> $GITHUB_PATH

      # Print the various tool paths and versions to help in debugging.
      - name: Print tool debugging info
        run: |
          echo $PATH
          which bazelisk
          bazelisk --version
          which python
          python --version
          which clang
          clang --version
          which clang++
          clang++ --version
          which clang-format
          clang-format --version

      # Make the date available to subsequent steps.
      - name: Get date
        id: date
        shell: bash
        run: |
          echo "::set-output name=date::$(/bin/date -u "+%Y%m%d")"

      # Preserve and restore the Bazel cache across builds.
      - name: Cache Bazel build data
        uses: actions/cache@v2
        with:
          path: |
            ${{ env.BAZEL_DISK_CACHE_PATH }}
          # The `bazel-1` string here and below in the key acts as a counter
          # that can be incremented to rebase the cache in the event of
          # persistent corruption or other rare bug. The `-1-` prefix to the
          # date can be incremented when adding new targets or updating this
          # configuration and a new cache should be created but there is no
          # reason to discard prior caches.
          key: |
            bazel-1-${{ matrix.os }}-${{ matrix.build_mode }}-1-${{ steps.date.outputs.date }}
          # When we get a cache miss, try finding the most recent previous day's
          # cache to start.
          restore-keys: |
            bazel-1-${{ matrix.os }}-${{ matrix.build_mode }}-

      # Reset all the access-times for the bazel disk cache to 1984. We really
      # just need a time far in the past to ensure even with `relatime` or
      # similar, the filesystem will track how much of the disk cache is
      # actually still *used* in the course of the build. This lets us GC
      # anything unused before potentially creating a new cache entry.
      - name: Reset Bazel disk cache atimes
        run: |
          mkdir -p ${{ env.BAZEL_DISK_CACHE_PATH }}
          find ${{ env.BAZEL_DISK_CACHE_PATH }}/ -type f -exec touch -a -t 198401010000 '{}' '+'

      # Print Bazel diagnostics to make debugging easier.
      - name: Print Bazel info
        run: |
          bazelisk info

      # Build all targets first to isolate build failures.
      - name: Build (${{ matrix.build_mode }})
        run: |
          bazelisk build -c ${{ matrix.build_mode }} --verbose_failures \
            //...:all

      # Run all test targets.
      - name: Test (${{ matrix.build_mode }})
        run: |
          bazelisk test -c ${{ matrix.build_mode }} --test_output errors \
            --verbose_failures //...:all

      # We manually shut down the Bazel server to make sure the cached files
      # don't interact with it.
      - name: Shutdown Bazel
        run: |
          bazelisk shutdown

      # Since we reset the `atime`s of the disk cache to ancient history,
      # everything that ended up accessed by the build and test should have a
      # recent `atime`. Delete any files whose `atime` is more than 7 days old.
      # We print some statistics to try to help with any debugging later on.
      - name: Remove unused disk cache files
        run: |
          find ${{ env.BAZEL_DISK_CACHE_PATH }}/ -type f | wc -l
          find ${{ env.BAZEL_DISK_CACHE_PATH }}/ -type f -atime +7 | wc -l
          find ${{ env.BAZEL_DISK_CACHE_PATH }}/ -type f -atime +7 -delete