text: #!/usr/bin/env python2.7
  # 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.
  
  """Wraps gclient calls with annotated output.
  
  Note that you will have to use -- to stop option parsing for gclient flags.
  
  To run `gclient sync --gclientfile=.gclient` and annotate got_v8_revision:
    `annotated_gclient.py --revision-mapping='{"src/v8": "got_v8_revision"}' --
        sync --gclientfile=.gclient`
  """
  
  import contextlib
  import json
  import optparse
  import os
  import subprocess
  import sys
  import tempfile
  
  
  @contextlib.contextmanager
  def temp_filename(suffix='', prefix='tmp'):
    output_fd, output_file = tempfile.mkstemp(suffix=suffix, prefix=prefix)
    os.close(output_fd)
  
    yield output_file
  
    try:
      os.remove(output_file)
    except OSError as e:
      print 'Error cleaning up temp file %s: %s' % (output_file, e)
  
  
  def parse_got_revision(filename, revision_mapping):
    result = {}
    with open(filename) as f:
      data = json.load(f)
  
    for path, info in data['solutions'].iteritems():
      # gclient json paths always end with a slash
      path = path.rstrip('/')
      if path in revision_mapping:
        propname = revision_mapping[path]
        result[propname] = info['revision']
  
    return result
  
  
  def emit_buildprops(got_revisions):
    for prop, revision in got_revisions.iteritems():
      print '@@@SET_BUILD_PROPERTY@%s@%s@@@' % (prop, json.dumps(revision))
  
  
  def main():
    parser = optparse.OptionParser(
        description=('Runs gclient and annotates the output with any '
                     'got_revisions.'))
    parser.add_option('--revision-mapping', default='{}',
                      help='json dict of directory-to-property mappings.')
    parser.add_option('--suffix', default='gclient',
                      help='tempfile suffix')
    opts, args = parser.parse_args()
  
    revision_mapping = json.loads(opts.revision_mapping)
  
    if not args:
      parser.error('Must provide arguments to gclient.')
  
    if any(a.startswith('--output-json') for a in args):
      parser.error('Can\'t call annotated_gclient with --output-json.')
  
    with temp_filename(opts.suffix) as f:
      cmd = ['gclient']
      cmd.extend(args)
      cmd.extend(['--output-json', f])
      p = subprocess.Popen(cmd)
      p.wait()
  
      if p.returncode == 0:
        revisions = parse_got_revision(f, revision_mapping)
        emit_buildprops(revisions)
      return p.returncode
  
  
  if __name__ == '__main__':
    sys.exit(main())
  