roll-pinned-toolchain-versions.yml

# Once a day, attempt to roll the pinned nightly and stable toolchain versions
# and update the codebase as necessary (in particular, by regenerating the files
# which store expected compiler output for UI tests; this output is not stable
# and may change between compiler versions). On success, submit the changes as a
# new PR. Note that this does not guarantee that the roll will succeed: PRs go
# through many tests which are not exercised here, and so the generated PR may
# still fail CI. In particular, some nightly releases do not support all of the
# target architectures that we use in CI; attempting to roll to any such release
# will fail.

name: Roll pinned toolchain versions
on:
  schedule:
    - cron: '29 12 * * *'
  workflow_dispatch:

permissions: read-all

jobs:
  roll:
    runs-on: ubuntu-latest
    strategy:
      matrix:
        toolchain: ["stable", "nightly"]
    name: Roll pinned toolchain ${{ matrix.toolchain }} version
    steps:
      - name: Checkout code
        uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4.1.1
        with:
          ref: main
          persist-credentials: false
      - name: Calculate target version
        run: |
          if [ "${{ matrix.toolchain }}" == stable ]; then
            # Install whatever the latest stable release is. This has the side
            # effect of determining the latest stable release so that we can
            # update `Cargo.toml`.
            echo "ZC_TARGET_TOOLCHAIN=stable" >> $GITHUB_ENV
          else
            # Use yesterday's date (`-d '-1 day'`) so we're sure the nightly for
            # that date has actually been published yet. This allows us to not
            # worry about what time of day this job runs.
            echo "ZC_TARGET_TOOLCHAIN=nightly-$(date -d '-1 day' +%Y-%m-%d)" >> $GITHUB_ENV
          fi
      - name: Install Rust with ${{ env.ZC_TARGET_TOOLCHAIN }} toolchain
        uses: dtolnay/rust-toolchain@00b49be78f40fba4e87296b2ead62868750bdd83 # stable
        with:
            toolchain: ${{ env.ZC_TARGET_TOOLCHAIN }}
            # We require the `rust-src` component to ensure that the compiler
            # error output generated during UI tests matches that expected by
            # CI; see `ci.yml` and
            # https://github.com/rust-lang/rust/issues/116433.
            components: rust-src
      - name: Update files
        run: |
          set -eo pipefail

          function validate-file {
            REGEX="$1"
            FILE="$2"
            grep "$REGEX" "$FILE" >/dev/null || { echo "Failed to find line matching regex '$REGEX' in $FILE" >&2; exit 1; }
          }

          function update-pinned-version {
            VERSION_NAME="$1"
            VERSION="$2"
            # For nightly, this is the same as `$VERSION`. For stable, it's
            # `stable` because `rustup` doesn't recognize that `x.y.z` refers to
            # the same thing as `stable` even if they're the same toolchain.
            VERSION_FOR_CARGO="$3"
            ZEROCOPY_FEATURES="$4"

            # Confirm that `Cargo.toml` lists the pinned version in the expected
            # format. This is a prerequisite for the subsequent `sed` command.
            REGEX="^pinned-$VERSION_NAME = \"[a-z0-9\.-]*\"$"
            validate-file "$REGEX" Cargo.toml
            sed -i -e "s/$REGEX/pinned-$VERSION_NAME = \"$VERSION\"/" Cargo.toml

            # Confirm that the update didn't bork `Cargo.toml`.
            validate-file "$REGEX" Cargo.toml

            # Update `.stderr` files as needed for the new version.
            TRYBUILD=overwrite cargo "+$VERSION_FOR_CARGO" test --package zerocopy $ZEROCOPY_FEATURES
            TRYBUILD=overwrite cargo "+$VERSION_FOR_CARGO" test --package zerocopy-derive
          }

          if [ "${{ matrix.toolchain }}" == stable ]; then
            STABLE_VERSION="$(cargo +stable version | sed -e 's/^cargo \([0-9\.]*\) .*/\1/')"
            update-pinned-version stable "$STABLE_VERSION" stable '--features __internal_use_only_features_that_work_on_stable'

            # Used as part of the branch name created by the "Submit PR" step.
            echo "ZC_VERSION_FOR_BRANCH_NAME=$STABLE_VERSION" >> $GITHUB_ENV
          else
            update-pinned-version nightly "$ZC_TARGET_TOOLCHAIN" "$ZC_TARGET_TOOLCHAIN" --all-features
            echo "ZC_VERSION_FOR_BRANCH_NAME=$ZC_TARGET_TOOLCHAIN" >> $GITHUB_ENV
          fi

      - name: Submit PR
        uses: peter-evans/create-pull-request@153407881ec5c347639a548ade7d8ad1d6740e38 # v5.0.2
        with:
          commit-message: "[ci] Roll pinned ${{ matrix.toolchain }} toolchain"
          author: Google PR Creation Bot <github-pull-request-creation-bot@google.com>
          committer: Google PR Creation Bot <github-pull-request-creation-bot@google.com>
          title: "[ci] Roll pinned ${{ matrix.toolchain }} toolchain"
          branch: roll-pinned-${{ matrix.toolchain }}-toolchain-to-${{ env.ZC_VERSION_FOR_BRANCH_NAME }}
          push-to-fork: google-pr-creation-bot/zerocopy
          token: ${{ secrets.GOOGLE_PR_CREATION_BOT_TOKEN }}