tools/sort_sources.py: sort C++ source file names in build files.

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 as an argument, sort C++ 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
+
+
+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++ 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 many cases that
+  the code cannot handle correctly (ex. comments within a list of source file
+  names).
+  """
+
+  output_lines = []
+  sources = []
+  for line in original_lines:
+    if re.search(r'^\s+[\'"].*\.(c|cc|cpp|h)[\'"],$', line):
+      sources.append(line)
+    else:
+      if sources:
+        output_lines.extend(sorted(sources))
+        sources = []
+      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())