Android wrapper: Support build.py without bundle.py

For Android, we don't want to first clone the sources
to a target directory in order to build the wrapper.

TEST=manually ran the script.
BUG=chromium:773875

Change-Id: I6b45868b8fb06274c29ce7e8dfc3d40f9a2f6aa5
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/toolchain-utils/+/1834484
Tested-by: Tobias Bosch <tbosch@google.com>
Reviewed-by: George Burgess <gbiv@chromium.org>

2 files changed, 17 insertions, 5 deletions

diff --git a/compiler_wrapper/build.py b/compiler_wrapper/build.py
index af3064e9..6b647714 100755
--- a/compiler_wrapper/build.py
+++ b/compiler_wrapper/build.py
@@ -10,6 +10,7 @@ from __future__ import print_function
 
 import argparse
 import os.path
+import re
 import subprocess
 import sys
 
@@ -45,8 +46,18 @@ def calc_go_args(args, version):
 
 
 def read_version(build_dir):
-  with open(os.path.join(build_dir, 'VERSION'), 'r') as r:
-    return r.read()
+  version_path = os.path.join(build_dir, 'VERSION')
+  if os.path.exists(version_path):
+    with open(version_path, 'r') as r:
+      return r.read()
+
+  last_commit_msg = subprocess.check_output(
+      ['git', '-C', build_dir, 'log', '-1', '--pretty=%B'])
+  # Use last found change id to support reverts as well.
+  change_ids = re.findall(r'Change-Id: (\w+)', last_commit_msg)
+  if not change_ids:
+    sys.exit("Couldn't find Change-Id in last commit message.")
+  return change_ids[-1]
 
 
 def main():
diff --git a/compiler_wrapper/bundle.py b/compiler_wrapper/bundle.py
index 63757f78..c1fa53e0 100755
--- a/compiler_wrapper/bundle.py
+++ b/compiler_wrapper/bundle.py
@@ -33,10 +33,11 @@ def copy_files(input_dir, output_dir):
 def read_change_id(input_dir):
   last_commit_msg = subprocess.check_output(
       ['git', '-C', input_dir, 'log', '-1', '--pretty=%B'])
-  match = re.search('Change-Id: (\\w+)', last_commit_msg)
-  if not match:
+  # Use last found change id to support reverts as well.
+  change_ids = re.findall(r'Change-Id: (\w+)', last_commit_msg)
+  if not change_ids:
     sys.exit("Couldn't find Change-Id in last commit message.")
-  return match.group(1)
+  return change_ids[-1]
 
 
 def write_readme(input_dir, output_dir, change_id):