Patch path filtering script.

scripts/slave/apply_svn_patch.py

 #!/usr/bin/python
 # Copyright 2013 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.
 
 import optparse
 import subprocess
 import sys
 
 
 def main():
   parser = optparse.OptionParser()
   parser.add_option('-p', '--patch-url',
                     help='The SVN URL to download the patch from.')
   parser.add_option('-r', '--root-dir',
                     help='The root dir in which to apply patch.')
+  parser.add_option('', '--path-filter-script',
+                    help=('A script that filter out contents of a patch. The '
+                          'script must use stdin for input and stdout for '
+                          'output.'))
+  parser.add_option('', '--path-filter',
+                    help=('The paths that shall be allowed (must specify the '
+                          'path filter script to use this).'))
+  parser.add_option('', '--strip-level', type='int', default=0,
+                    help=('The number of components to be stripped from the '
+                          'filenames in the patch. Default: %default.'))
 
   options, args = parser.parse_args()
   if args:
     parser.error('Unused args: %s' % args)
   if not (options.patch_url and options.root_dir):
     parser.error('A patch URL and root directory should be specified.')
+  if ((options.path_filter_script and not options.path_filter) or
+      (options.path_filter and not options.path_filter_script)):
+    parser.error('You must specify both path filter and a path filter script '
+                 'in order to use path filtering for patches.')
 
   svn_cat = subprocess.Popen(['svn', 'cat', options.patch_url],
                              stdout=subprocess.PIPE)
-  patch = subprocess.Popen(['patch', '-t', '-p', '0', '-d', options.root_dir],
-                           stdin=svn_cat.stdout)
+  patch_input = svn_cat.stdout
+  if options.path_filter_script:
+    filtering = subprocess.Popen(sys.executable, [options.path_filter_script,
+                                                  '-f', options.path_filter],
+                                 stdin=svn_cat.stdout, stdout=subprocess.PIPE)
+    patch_input = filtering.stdout
+  patch = subprocess.Popen(['patch', '-t', '-p', options.strip_level,
+                            '-d', options.root_dir],
+                           stdin=patch_input)
 
   _, err = patch.communicate()
   return err or None
 
 
 if __name__ == '__main__':
   sys.exit(main())