Script to check for holes in cherry-picks to release branches
Bug: b/286177952
Change-Id: Ie1141bf59f68c20d1fb6ba230963c7f9babc7130
diff --git a/tools/check-cherry-picks.py b/tools/check-cherry-picks.py
new file mode 100755
index 0000000..adf763c
--- /dev/null
+++ b/tools/check-cherry-picks.py
@@ -0,0 +1,184 @@
+#!/usr/bin/env python3
+# Copyright (c) 2023, the R8 project authors. Please see the AUTHORS file
+# for details. All rights reserved. Use of this source code is governed by a
+# BSD-style license that can be found in the LICENSE file.
+
+import subprocess
+import sys
+import re
+import r8_release
+
+class Branch:
+ def __init__(self, name, first, last=None):
+ self.name = name
+ self.first = first
+ self.last = last # optional last for testing purposes.
+
+ def origin(self):
+ return "origin/%s" % self.name
+
+ def last_or_origin(self):
+ return self.last if self.last else self.origin()
+
+ def __str__(self):
+ return self.name
+
+# The initial commit is the furthest back we need to search on main.
+# Currently, it is the merge point of main onto 4.0.23-dev
+MAIN = Branch('main', 'a2e203580aa00a36f85cd68d3d584b97aef34d59')
+OLDEST_BRANCH_VERSION = (4, 0)
+DEV_BRANCH_VERSION = [int(s) for s in r8_release.R8_DEV_BRANCH.split('.')]
+
+# List of change ids that should not be reported.
+IGNORED = [
+ 'I92d7bf3afbf609fdea21683941cfd15c90305cf2'
+]
+
+VERBOSE = False
+
+# Helper to call and decode a shell command.
+def run_cmd(cmd):
+ if VERBOSE:
+ print(' '.join(cmd))
+ return subprocess.check_output(cmd).decode('UTF-8')
+
+# Comparator on major and minor branch versions.
+def branch_version_less_than(b1, b2):
+ if b1[0] < b2[0]:
+ return True
+ if b1[0] == b2[0] and b1[1] < b2[1]:
+ return True
+ return False
+
+# Find all release branches between OLDEST_BRANCH and DEV_BRANCH
+def get_release_branches():
+ # Release branches are assumed to be of the form 'origin/X.Y'
+ out = run_cmd(['git', 'branch', '-r', '-l'])
+ pattern = re.compile('origin/(\d+).(\d+)')
+ releases = []
+ for line in out.split('\n'):
+ m = pattern.search(line.strip())
+ if m:
+ major = m.group(1)
+ minor = m.group(2)
+ if major and minor:
+ candidate = (int(major), int(minor))
+ if branch_version_less_than(candidate, OLDEST_BRANCH_VERSION):
+ continue
+ if branch_version_less_than(candidate, DEV_BRANCH_VERSION):
+ releases.extend(find_dev_cutoff(candidate))
+ return releases
+
+# Find the most recent commit hash that is for a -dev version.
+# This is the starting point for the map of commits after cutoff from main.
+def find_dev_cutoff(branch_version):
+ out = run_cmd([
+ 'git',
+ 'log',
+ 'origin/%d.%d' % branch_version,
+ '--grep', 'Version .*-dev',
+ '--pretty=oneline',
+ ])
+ # Format of output is: <hash> Version <version>-dev
+ try:
+ hash = out[0:out.index(' ')]
+ return [Branch('%d.%d' % branch_version, hash)]
+ except ValueError:
+ throw_error("Failed to find dev cutoff for branch %d.%d" % branch_version)
+
+# Build a map from each "Change-Id" hash to the hash of its commit.
+def get_change_id_map(branch):
+ out = run_cmd([
+ 'git',
+ 'log',
+ '%s..%s' % (branch.first, branch.last_or_origin())
+ ])
+ map = {}
+ current_commit = None
+ for line in out.split('\n'):
+ if line.startswith('commit '):
+ current_commit = line[len('commit '):]
+ assert len(current_commit) == 40
+ elif line.strip().startswith('Change-Id: '):
+ change_id = line.strip()[len('Change-Id: '):]
+ assert len(change_id) == 41
+ map[change_id] = current_commit
+ return map
+
+# Check if a specific commit is present on a specific branch.
+def is_commit_in(commit, branch):
+ out = run_cmd(['git', 'branch', '-r', branch.origin(), '--contains', commit])
+ return out.strip() == branch.origin()
+
+def main():
+ found_errors = False
+ # The main map is all commits back to the "init" point.
+ main_map = get_change_id_map(MAIN)
+ # Compute the release branches.
+ release_branches = get_release_branches()
+ # Populate the release maps with all commits after the last -dev point.
+ release_maps = {}
+ for branch in release_branches:
+ release_maps[branch.name] = get_change_id_map(branch)
+ # Each branch is then compared forwards with each subsequent branch.
+ for i in range(len(release_branches)):
+ branch = release_branches[i]
+ newer_branches = release_branches[i+1:]
+ if (len(newer_branches) == 0):
+ print('Last non-dev release branch is %s, nothing to check.' % branch)
+ continue
+ print('Checking branch %s.' % branch)
+ changes = release_maps[branch.name]
+ cherry_picks_count = 0
+ for change in changes.keys():
+ is_cherry_pick = False
+ missing_from = None
+ commit_on_main = main_map.get(change)
+ for newer_branch in newer_branches:
+ if change in release_maps[newer_branch.name]:
+ is_cherry_pick = True
+ # If the change is in the release mappings check for holes.
+ if missing_from:
+ found_errors = change_error(
+ change,
+ 'Error: missing Change-Id %s on branch %s. '
+ 'Is present on %s and again on %s.' % (
+ change, missing_from, branch, newer_branch,
+ ))
+ elif commit_on_main:
+ is_cherry_pick = True
+ # The change is not in the non-dev part of the branch, so we need to
+ # check that the fork from main included the change.
+ if not is_commit_in(commit_on_main, newer_branch):
+ found_errors = change_error(
+ change,
+ 'Error: missing Change-Id %s on branch %s. '
+ 'Is present on %s and on main as commit %s.' % (
+ change, newer_branch, branch, commit_on_main
+ ))
+ else:
+ # The change is not on "main" so we just record for holes on releases.
+ missing_from = newer_branch
+ if is_cherry_pick:
+ cherry_picks_count += 1
+ print('Found %d cherry-picks (out of %d commits).' % (
+ cherry_picks_count, len(changes)))
+
+ if found_errors:
+ return 1
+ return 0
+
+def change_error(change, msg):
+ if change in IGNORED:
+ return False
+ error(msg)
+ return True
+
+def throw_error(msg):
+ raise ValueError(msg)
+
+def error(msg):
+ print(msg, file=sys.stderr)
+
+if __name__ == '__main__':
+ sys.exit(main())
