native_client_sdk/src/tools/fix_deps.py

   1 #!/usr/bin/env python
   2 # Copyright (c) 2013 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 """Fixup GCC-generated dependency files.
   7
   8 Modify GCC generated dependency files so they are more suitable for including
   9 in a GNU Makefile.  Without the fixups, deleting or renaming headers can cause
  10 the build to be broken.
  11
  12 See http://mad-scientist.net/make/autodep.html for more details of the problem.
  13 """
  14
  15 import os
  16 import optparse
  17 import sys
  18
  19 TAG_LINE = '# Updated by fix_deps.py\n'
  20
  21
  22 class Error(Exception):
  23   pass
  24
  25
  26 def ParseLine(line, new_target):
  27   """Parse one line of a GCC-generated deps file.
  28
  29   Each line contains an optional target and then a list
  30   of space seperated dependencies.  Spaces within filenames
  31   are escaped with a backslash.
  32   """
  33   filenames = []
  34
  35   if new_target and ':' in line:
  36     line = line.split(':', 1)[1]
  37
  38   line = line.strip()
  39   line = line.rstrip('\\')
  40
  41   while True:
  42     # Find the next non-escaped space
  43     line = line.strip()
  44     pos = line.find(' ')
  45     while pos > 0 and line[pos-1] == '\\':
  46       pos = line.find(' ', pos+1)
  47
  48     if pos == -1:
  49       filenames.append(line)
  50       break
  51     filenames.append(line[:pos])
  52     line = line[pos+1:]
  53
  54   return filenames
  55
  56
  57 def FixupDepFile(filename, output_filename=None):
  58   if not os.path.exists(filename):
  59     raise Error('File not found: %s' % filename)
  60
  61   if output_filename is None:
  62     output_filename = filename
  63
  64   outlines = [TAG_LINE]
  65   deps = []
  66   new_target = True
  67   with open(filename) as infile:
  68     for line in infile:
  69       if line == TAG_LINE:
  70         raise Error('Already processed: %s' % filename)
  71       outlines.append(line)
  72       deps += ParseLine(line, new_target)
  73       new_target = line.endswith('\\')
  74
  75   # For every depenency found output a dummy target with no rules
  76   for dep in deps:
  77     outlines.append('%s:\n' % dep)
  78
  79   with open(output_filename, 'w') as outfile:
  80     for line in outlines:
  81       outfile.write(line)
  82
  83
  84 def main(argv):
  85   usage = "usage: %prog [options] <dep_file>"
  86   parser = optparse.OptionParser(usage=usage, description=__doc__)
  87   parser.add_option('-o', '--output', help='Output filename (defaults to '
  88                     'input name with .deps extension')
  89   parser.add_option('-c', '--clean', action='store_true',
  90                     help='Remove input file after writing output')
  91   options, args = parser.parse_args(argv)
  92   if not args:
  93     raise parser.error('No input file specified')
  94   if len(args) > 1:
  95     raise parser.error('Only one argument supported')
  96   input_filename = args[0]
  97   output_filename = options.output
  98   if not output_filename:
  99     output_filename = os.path.splitext(input_filename)[0] + '.deps'
 100   FixupDepFile(input_filename, output_filename)
 101   if options.clean and input_filename != output_filename:
 102     os.remove(input_filename)
 103
 104
 105 if __name__ == '__main__':
 106   try:
 107     sys.exit(main(sys.argv[1:]))
 108   except Error as e:
 109     sys.stderr.write('%s: %s\n' % (os.path.basename(__file__), e))
 110     sys.exit(1)