text: #!/usr/bin/env python
  
  # Copyright 2014 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.
  
  '''Uses the closure compiler to check the ChromeVox javascript files.
  
  With no arguments, checks all ChromeVox scripts.  If any arguments are
  specified, only scripts that include any of the specified files will be
  compiled.  A useful argument list is the output of the command
  'git diff --name-only --relative'.
  '''
  
  import optparse
  import os
  import re
  import sys
  
  from multiprocessing import pool
  
  from jsbundler import Bundle, CalcDeps, ReadSources
  from jscompilerwrapper import RunCompiler
  
  _SCRIPT_DIR = os.path.dirname(os.path.abspath(__file__))
  _CHROME_SOURCE_DIR = os.path.normpath(
      os.path.join(_SCRIPT_DIR, *[os.path.pardir] * 6))
  
  
  def CVoxPath(path='.'):
    '''Converts a path relative to the top-level chromevox directory to a
    path relative to the current directory.
    '''
    return os.path.relpath(os.path.join(_SCRIPT_DIR, '..', path))
  
  
  # Externs common to many ChromeVox scripts.
  _COMMON_EXTERNS = [
      CVoxPath('common/externs.js'),
      CVoxPath('common/chrome_extension_externs.js'),
      CVoxPath('chromevox/background/externs.js'),
      CVoxPath('chromevox/injected/externs.js'),
      CVoxPath('liblouis_nacl/externs.js'),
      CVoxPath('host/chrome/externs.js')]
  
  # List of top-level scripts and externs that we can check.
  _TOP_LEVEL_SCRIPTS = [
      [[CVoxPath('chromevox/background/kbexplorer_loader.js')],
       [CVoxPath('common/chrome_extension_externs.js')]],
      [[CVoxPath('chromevox/background/loader.js')], _COMMON_EXTERNS],
      [[CVoxPath('chromevox/background/options_loader.js')], _COMMON_EXTERNS],
      [[CVoxPath('chromevox/injected/loader.js')], _COMMON_EXTERNS],
      ]
  
  
  def _Compile(js_files, externs):
    try:
      return RunCompiler(js_files, externs)
    except KeyboardInterrupt:
      return (False, 'KeyboardInterrupt')
  
  
  def CheckChromeVox(changed_files=None):
    if changed_files is not None:
      changed_files_set = frozenset(
          (os.path.relpath(path) for path in changed_files))
      if len(changed_files_set) == 0:
        return (True, '')
    else:
      changed_files_set = None
    ret_success = True
    ret_output = ''
    roots = [CVoxPath(),
             os.path.relpath(
                 os.path.join(
                     _CHROME_SOURCE_DIR,
                     'chrome/third_party/chromevox/third_party/closure-library/'
                     'closure/goog'))]
    sources = ReadSources(roots, need_source_text=True,
                          exclude=[re.compile('testing')])
    work_pool = pool.Pool(len(_TOP_LEVEL_SCRIPTS))
    try:
      results = []
      for top_level in _TOP_LEVEL_SCRIPTS:
        tl_files, externs = top_level
        bundle = Bundle()
        CalcDeps(bundle, sources, tl_files)
        bundle.Add((sources[name] for name in tl_files))
        ordered_paths = list(bundle.GetInPaths())
        if (changed_files_set is not None and
            changed_files_set.isdisjoint(ordered_paths + externs)):
          continue
        print 'Compiling %s' % ','.join(tl_files)
        results.append([tl_files,
                        work_pool.apply_async(
                            _Compile,
                            args=[ordered_paths, externs])])
      for result in results:
        tl_files = result[0]
        success, output = result[1].get()
        if not success:
          ret_output += '\nFrom compiling %s:\n%s\n' % (','.join(tl_files),
                                                        output)
          ret_success = False
      work_pool.close()
    except:
      work_pool.terminate()
      raise
    finally:
      work_pool.join()
    return (ret_success, ret_output)
  
  
  def main():
    parser = optparse.OptionParser(description=__doc__)
    parser.usage = '%prog [<changed_file>...]'
    _, args = parser.parse_args()
  
    changed_paths = None
    if len(args) > 0:
      changed_paths = (os.path.relpath(p) for p in args)
    success, output = CheckChromeVox(changed_paths)
    if len(output) > 0:
      print output
    return int(not success)
  
  
  if __name__ == '__main__':
    sys.exit(main())
  