Add presubmit check to prevent package boundary violations.
BUG=webrtc:6954
NOTRY=True
Review-Url: https://codereview.webrtc.org/2629723004
Cr-Commit-Position: refs/heads/master@{#16357}
diff --git a/tools-webrtc/check_package_boundaries.py b/tools-webrtc/check_package_boundaries.py
new file mode 100644
index 0000000..75588fa
--- /dev/null
+++ b/tools-webrtc/check_package_boundaries.py
@@ -0,0 +1,137 @@
+#!/usr/bin/env python
+
+# Copyright (c) 2017 The WebRTC project authors. All Rights Reserved.
+#
+# Use of this source code is governed by a BSD-style license
+# that can be found in the LICENSE file in the root of the source
+# tree. An additional intellectual property rights grant can be found
+# in the file PATENTS. All contributing project authors may
+# be found in the AUTHORS file in the root of the source tree.
+
+import argparse
+import logging
+import os
+import re
+import sys
+
+
+DISPLAY_LEVEL = 1
+IGNORE_LEVEL = 0
+
+# TARGET_RE matches a GN target, and extracts the target name and the contents.
+TARGET_RE = re.compile(r'\d+\$(?P<indent>\s*)\w+\("(?P<target_name>\w+)"\) {'
+ r'(?P<target_contents>.*?)'
+ r'\d+\$(?P=indent)}',
+ re.MULTILINE | re.DOTALL)
+
+# SOURCES_RE matches a block of sources inside a GN target.
+SOURCES_RE = re.compile(r'sources \+?= \[(?P<sources>.*?)\]',
+ re.MULTILINE | re.DOTALL)
+
+LOG_FORMAT = '%(message)s'
+ERROR_MESSAGE = ("{}:{} in target '{}':\n"
+ " Source file '{}'\n"
+ " crosses boundary of package '{}'.\n")
+
+
+class Logger(object):
+ def __init__(self, messages_left=None):
+ self.log_level = DISPLAY_LEVEL
+ self.messages_left = messages_left
+
+ def log(self, build_file_path, line_number, target_name, source_file,
+ subpackage):
+ if self.messages_left is not None:
+ if not self.messages_left:
+ self.log_level = IGNORE_LEVEL
+ else:
+ self.messages_left -= 1
+ message = ERROR_MESSAGE.format(build_file_path, line_number, target_name,
+ source_file, subpackage)
+ logging.log(self.log_level, message)
+
+
+def _BuildSubpackagesPattern(packages, query):
+ """Returns a regular expression that matches source files inside subpackages
+ of the given query."""
+ query += '/'
+ length = len(query)
+ pattern = r'(?P<line_number>\d+)\$\s*"(?P<source_file>(?P<subpackage>'
+ pattern += '|'.join(package[length:] for package in packages
+ if package.startswith(query))
+ pattern += r')/[\w\./]*)"'
+ return re.compile(pattern)
+
+
+def _ReadFileAndPrependLines(file_path):
+ """Reads the contents of a file and prepends the line number to every line."""
+ with open(file_path) as f:
+ return "".join("{}${}".format(line_number, line)
+ for line_number, line in enumerate(f, 1))
+
+
+def _CheckBuildFile(build_file_path, packages, logger):
+ """Iterates oven all the targets of the given BUILD.gn file, and verifies that
+ the source files referenced by it don't belong to any of it's subpackages.
+ Returns True if a package boundary violation was found.
+ """
+ found_violations = False
+ package = os.path.dirname(build_file_path)
+ subpackages_re = _BuildSubpackagesPattern(packages, package)
+
+ build_file_contents = _ReadFileAndPrependLines(build_file_path)
+ for target_match in TARGET_RE.finditer(build_file_contents):
+ target_name = target_match.group('target_name')
+ target_contents = target_match.group('target_contents')
+ for sources_match in SOURCES_RE.finditer(target_contents):
+ sources = sources_match.group('sources')
+ for subpackages_match in subpackages_re.finditer(sources):
+ subpackage = subpackages_match.group('subpackage')
+ source_file = subpackages_match.group('source_file')
+ line_number = subpackages_match.group('line_number')
+ if subpackage:
+ found_violations = True
+ logger.log(build_file_path, line_number, target_name, source_file,
+ subpackage)
+
+ return found_violations
+
+
+def CheckPackageBoundaries(root_dir, logger, build_files=None):
+ packages = [root for root, _, files in os.walk(root_dir)
+ if 'BUILD.gn' in files]
+ default_build_files = [os.path.join(package, 'BUILD.gn')
+ for package in packages]
+
+ build_files = build_files or default_build_files
+ return any([_CheckBuildFile(build_file_path, packages, logger)
+ for build_file_path in build_files])
+
+
+def main():
+ parser = argparse.ArgumentParser(
+ description='Script that checks package boundary violations in GN '
+ 'build files.')
+
+ parser.add_argument('root_dir', metavar='ROOT_DIR',
+ help='The root directory that contains all BUILD.gn '
+ 'files to be processed.')
+ parser.add_argument('build_files', metavar='BUILD_FILE', nargs='*',
+ help='A list of BUILD.gn files to be processed. If no '
+ 'files are given, all BUILD.gn files under ROOT_DIR '
+ 'will be processed.')
+ parser.add_argument('--max_messages', type=int, default=None,
+ help='If set, the maximum number of violations to be '
+ 'displayed.')
+
+ args = parser.parse_args()
+
+ logging.basicConfig(format=LOG_FORMAT)
+ logging.getLogger().setLevel(DISPLAY_LEVEL)
+ logger = Logger(args.max_messages)
+
+ return CheckPackageBoundaries(args.root_dir, logger, args.build_files)
+
+
+if __name__ == '__main__':
+ sys.exit(main())
