Merge #203
203: Add a CI tool that prints a size diff for incoming PRs. r=jrvanwhy a=jrvanwhy
The diff is computed by building the examples with `make examples` both in the PR's target branch and the merge result, and running `diff` on the result.
This is built using GitHub Actions because upstream Tock is moving to GitHub Actions (see https://github.com/tock/tock/pull/1815, and [this core WG discussion](https://github.com/tock/tock/blob/master/doc/wg/core/notes/core-notes-2020-04-24.md#ci-infrastructure-travis-to-github-actions)).
Co-authored-by: Johnathan Van Why <jrvanwhy@google.com>
diff --git a/.github/workflows/size-diff.yml b/.github/workflows/size-diff.yml
new file mode 100644
index 0000000..d35fde0
--- /dev/null
+++ b/.github/workflows/size-diff.yml
@@ -0,0 +1,55 @@
+# Calculates the size diffs for the each example binary. Runs when a pull
+# request is created or modified.
+
+name: size-diff
+on: pull_request
+
+jobs:
+ size-diff:
+ # Using ubuntu-latest can cause breakage when ubuntu-latest is updated to
+ # point at a new Ubuntu version. Instead, explicitly specify the version, so
+ # we can update when we need to. This *could* break if we don't update it
+ # until support for 18.04 is dropped, but it is likely we'll have a reason
+ # to update to a newer Ubuntu before then anyway.
+ runs-on: ubuntu-18.04
+
+ steps:
+ # Clones a single commit from the libtock-rs repository. The commit cloned
+ # is a merge commit between the PR's target branch and the PR's source.
+ # We'll later add another commit (the pre-merge target branch) to the
+ # repository.
+ - name: Clone repository
+ uses: actions/checkout@v2.3.0
+
+ # Install a Rust toolchain with the components necessary to run
+ # `print-sizes`. This action doesn't seem to be able to install toolchains
+ # for multiple targets, so I add the targets later in the "size report"
+ # step.
+ - name: Install Rust toolchain
+ uses: actions-rs/toolchain@v1.0.6
+ with:
+ profile: minimal
+
+ # The main diff script. Stores the sizes of the example binaries for both
+ # the merge commit and the target branch. We display the diff in a
+ # separate step to make it easy to navigate to in the GitHub Actions UI.
+ - name: Compute sizes
+ run: |
+ UPSTREAM_REMOTE_NAME="${UPSTREAM_REMOTE_NAME:-origin}"
+ GITHUB_BASE_REF="${GITHUB_BASE_REF:-master}"
+ cd "${GITHUB_WORKSPACE}"
+ rustup target add riscv32imc-unknown-none-elf thumbv7em-none-eabi
+ make -j2 examples # The VM this runs on has 2 logical cores.
+ cargo run --release -p print-sizes >'${{runner.temp}}/merge-sizes'
+ git remote set-branches "${UPSTREAM_REMOTE_NAME}" "${GITHUB_BASE_REF}"
+ git fetch --depth=1 "${UPSTREAM_REMOTE_NAME}" "${GITHUB_BASE_REF}"
+ git checkout "${UPSTREAM_REMOTE_NAME}/${GITHUB_BASE_REF}"
+ make -j2 examples
+ cargo run --release -p print-sizes >'${{runner.temp}}/base-sizes'
+
+ # Computes and displays the size diff. diff returns a nonzero status code
+ # if the files differ, and GitHub interprets a nonzero status code as an
+ # error. To avoid GitHub interpreting a difference as an error, we add
+ # || exit 0 to the command.
+ - name: Size diff
+ run: diff '${{runner.temp}}/base-sizes' '${{runner.temp}}/merge-sizes' || exit 0
