bloat check: make more robust

The use of 'C^' (parent) in 'git rebase' is counterintuitive,
at least to me: when C is a merge of multiple commits, rebase
picks each of those commits. That probably makes good sense
to a git expert, which I'm not.

Solution: forget using '^', just calculate the baseline sizes
by doing a checkout of the PR's parent.

Also: compute PR parent using git-merge-base instead of
blindly trusting $DEST_BRANCH (which may be volatile as
other PRs are merged).

Also: run git-rebase directly, not via make rule. That
indirection is too confusing here.

Signed-off-by: Ed Santiago <santiago@redhat.com>
This commit is contained in:
Ed Santiago
2022-05-10 05:27:13 -06:00
parent 28588235d2
commit 82f2b3edbc

View File

@ -250,16 +250,23 @@ function _run_altbuild() {
case "$ALT_NAME" in
*Each*)
git fetch origin
# The check-size script, introduced 2022-03-22 in #13518,
# The make-and-check-size script, introduced 2022-03-22 in #13518,
# runs 'make' (the original purpose of this check) against
# each commit, then checks image sizes to make sure that
# none have grown beyond a given limit. That of course
# requires a baseline, which is why we use '^' to start
# with the *parent* commit of this PR, not the first commit.
# requires a baseline, so our first step is to build the
# branch point of the PR.
local context_dir savedhead pr_base
context_dir=$(mktemp -d --tmpdir make-size-check.XXXXXXX)
make build-all-new-commits \
GIT_BASE_BRANCH=origin/"${DEST_BRANCH}^" \
MAKE="hack/make-and-check-size $context_dir"
savedhead=$(git rev-parse HEAD)
# Push to PR base. First run of the script will write size files
pr_base=$(git merge-base --fork-point origin/$DEST_BRANCH)
git checkout $pr_base
hack/make-and-check-size $context_dir
# pop back to PR, and run incremental makes. Subsequent script
# invocations will compare against original size.
git checkout $savedhead
git rebase $pr_base -x "hack/make-and-check-size $context_dir"
rm -rf $context_dir
;;
*Windows*)