tools/sort_sources.py

#!/usr/bin/env python
# Copyright 2015 The Chromium Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

"""Given a GYP/GN filename, sort C-ish source files in that file.

Shows a diff and prompts for confirmation before doing the deed.
Works great with tools/git/for-all-touched-files.py.
"""

import difflib
import optparse
import re
import sys

from yes_no import YesNo

SUFFIXES = ['c', 'cc', 'cpp', 'h', 'mm', 'rc', 'rc.version', 'ico', 'def',
            'release']
SOURCE_PATTERN = re.compile('^\s+[\'"].*\.(%s)[\'"],$' %
                            '|'.join([re.escape(x) for x in SUFFIXES]))
COMMENT_PATTERN = re.compile('^\s+#')

def SortSources(original_lines):
  """Sort source file names in |original_lines|.

  Args:
    original_lines: Lines of the original content as a list of strings.

  Returns:
    Lines of the sorted content as a list of strings.

  The algorithm is fairly naive. The code tries to find a list of C-ish
  source file names by a simple regex, then sort them. The code does not try
  to understand the syntax of the build files, hence there are some cases
  that the code cannot handle correctly (ex. blank lines within a list of
  source file names).
  """

  output_lines = []
  comments = []
  sources = []
  for line in original_lines:
    if re.search(COMMENT_PATTERN, line):
      comments.append(line)
    elif re.search(SOURCE_PATTERN, line):
      # Associate the line with the preceeding comments.
      sources.append([line, comments])
      comments = []
    else:
      # |sources| should be flushed first, to handle comments at the end of a
      # source list correctly.
      if sources:
        for source_line, source_comments in sorted(sources):
          output_lines.extend(source_comments)
          output_lines.append(source_line)
        sources = []
      if comments:
        output_lines.extend(comments)
        comments = []
      output_lines.append(line)
  return output_lines


def ProcessFile(filename, should_confirm):
  """Process the input file and rewrite if needed.

  Args:
    filename: Path to the input file.
    should_confirm: If true, diff and confirmation prompt are shown.
  """

  original_lines = []
  with open(filename, 'r') as input_file:
    for line in input_file:
      original_lines.append(line)

  new_lines = SortSources(original_lines)
  if original_lines == new_lines:
    print '%s: no change' % filename
    return

  if should_confirm:
    diff = difflib.unified_diff(original_lines, new_lines)
    sys.stdout.writelines(diff)
    if not YesNo('Use new file (y/N)'):
      return

  with open(filename, 'w') as output_file:
    output_file.writelines(new_lines)


def main():
  parser = optparse.OptionParser(usage='%prog filename1 filename2 ...')
  parser.add_option('-f', '--force', action='store_false', default=True,
                    dest='should_confirm',
                    help='Turn off confirmation prompt.')
  opts, filenames = parser.parse_args()

  if len(filenames) < 1:
    parser.print_help()
    return 1

  for filename in filenames:
    ProcessFile(filename, opts.should_confirm)


if __name__ == '__main__':
  sys.exit(main())