Moving check_package_boundaries to the presubmit checks directory

tools_webrtc/check_package_boundaries.py

-#!/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 += os.path.sep
-  length = len(query)
-  pattern = r'(?P<line_number>\d+)\$\s*"(?P<source_file>(?P<subpackage>'
-  pattern += '|'.join(package[length:].replace(os.path.sep, '/')
-                      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())