tools/sort-headers.py

   1 #!/usr/bin/env python
   2 # Copyright (c) 2012 The Chromium Authors. All rights reserved.
   3 # Use of this source code is governed by a BSD-style license that can be
   4 # found in the LICENSE file.
   5
   6 """Given a filename as an argument, sort the #include/#imports in that file.
   7
   8 Shows a diff and prompts for confirmation before doing the deed.
   9 Works great with tools/git/for-all-touched-files.py.
  10 """
  11
  12 import optparse
  13 import os
  14 import sys
  15 import termios
  16 import tty
  17
  18
  19 def YesNo(prompt):
  20   """Prompts with a yes/no question, returns True if yes."""
  21   print prompt,
  22   sys.stdout.flush()
  23   # http://code.activestate.com/recipes/134892/
  24   fd = sys.stdin.fileno()
  25   old_settings = termios.tcgetattr(fd)
  26   ch = 'n'
  27   try:
  28     tty.setraw(sys.stdin.fileno())
  29     ch = sys.stdin.read(1)
  30   finally:
  31     termios.tcsetattr(fd, termios.TCSADRAIN, old_settings)
  32   print ch
  33   return ch in ('Y', 'y')
  34
  35
  36 def IncludeCompareKey(line):
  37   """Sorting comparator key used for comparing two #include lines.
  38   Returns the filename without the #include/#import prefix.
  39   """
  40   for prefix in ('#include ', '#import '):
  41     if line.startswith(prefix):
  42       line = line[len(prefix):]
  43       break
  44
  45   # The win32 api has all sorts of implicit include order dependencies :-/
  46   # Give a few headers special sort keys that make sure they appear before all
  47   # other headers.
  48   if line.startswith('<windows.h>'):  # Must be before e.g. shellapi.h
  49     return '0'
  50   if line.startswith('<unknwn.h>'):  # Must be before e.g. intshcut.h
  51     return '1'
  52
  53   # C++ system headers should come after C system headers.
  54   if line.startswith('<'):
  55     if line.find('.h>') != -1:
  56       return '2' + line
  57     else:
  58       return '3' + line
  59
  60   return '4' + line
  61
  62
  63 def IsInclude(line):
  64   """Returns True if the line is an #include/#import line."""
  65   return line.startswith('#include ') or line.startswith('#import ')
  66
  67
  68 def SortHeader(infile, outfile):
  69   """Sorts the headers in infile, writing the sorted file to outfile."""
  70   for line in infile:
  71     if IsInclude(line):
  72       headerblock = []
  73       while IsInclude(line):
  74         headerblock.append(line)
  75         line = infile.next()
  76       for header in sorted(headerblock, key=IncludeCompareKey):
  77         outfile.write(header)
  78       # Intentionally fall through, to write the line that caused
  79       # the above while loop to exit.
  80     outfile.write(line)
  81
  82
  83 def DiffAndConfirm(filename, should_confirm):
  84   """Shows a diff of what the tool would change the file named
  85   filename to.  Shows a confirmation prompt if should_confirm is true.
  86   Saves the resulting file if should_confirm is false or the user
  87   answers Y to the confirmation prompt.
  88   """
  89   fixfilename = filename + '.new'
  90   infile = open(filename, 'r')
  91   outfile = open(fixfilename, 'w')
  92   SortHeader(infile, outfile)
  93   infile.close()
  94   outfile.close()  # Important so the below diff gets the updated contents.
  95
  96   try:
  97     diff = os.system('diff -u %s %s' % (filename, fixfilename))
  98     if diff >> 8 == 0:  # Check exit code.
  99       print '%s: no change' % filename
 100       return
 101
 102     if not should_confirm or YesNo('Use new file (y/N)?'):
 103       os.rename(fixfilename, filename)
 104   finally:
 105     try:
 106       os.remove(fixfilename)
 107     except OSError:
 108       # If the file isn't there, we don't care.
 109       pass
 110
 111
 112 def main():
 113   parser = optparse.OptionParser(usage='%prog filename1 filename2 ...')
 114   parser.add_option('-f', '--force', action='store_false', default=True,
 115                     dest='should_confirm',
 116                     help='Turn off confirmation prompt.')
 117   opts, filenames = parser.parse_args()
 118
 119   if len(filenames) < 1:
 120     parser.print_help()
 121     return 1
 122
 123   for filename in filenames:
 124     DiffAndConfirm(filename, opts.should_confirm)
 125
 126
 127 if __name__ == '__main__':
 128   sys.exit(main())