text: # 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.
  
  """Script that is used by PRESUBMIT.py to run style checks on Java files."""
  
  import os
  import subprocess
  import xml.dom.minidom
  
  
  CHROMIUM_SRC = os.path.normpath(
      os.path.join(os.path.dirname(__file__),
                   os.pardir, os.pardir, os.pardir))
  CHECKSTYLE_ROOT = os.path.join(CHROMIUM_SRC, 'third_party', 'checkstyle',
                                 'checkstyle-6.1-all.jar')
  
  
  def RunCheckstyle(input_api, output_api, style_file, black_list=None):
    if not os.path.exists(style_file):
      file_error = ('  Java checkstyle configuration file is missing: '
                    + style_file)
      return [output_api.PresubmitError(file_error)]
  
    # Filter out non-Java files and files that were deleted.
    java_files = [x.AbsoluteLocalPath() for x in input_api.AffectedSourceFiles(
                  lambda f: input_api.FilterSourceFile(f, black_list=black_list))
                  if os.path.splitext(x.LocalPath())[1] == '.java']
    if not java_files:
      return []
  
    # Run checkstyle
    checkstyle_env = os.environ.copy()
    checkstyle_env['JAVA_CMD'] = 'java'
    try:
      check = subprocess.Popen(['java', '-cp',
                                CHECKSTYLE_ROOT,
                                'com.puppycrawl.tools.checkstyle.Main', '-c',
                                style_file, '-f', 'xml'] + java_files,
                                stdout=subprocess.PIPE, env=checkstyle_env)
      stdout, _ = check.communicate()
    except OSError as e:
      import errno
      if e.errno == errno.ENOENT:
        install_error = ('  checkstyle is not installed. Please run '
                         'build/install-build-deps-android.sh')
        return [output_api.PresubmitPromptWarning(install_error)]
  
    result_errors = []
    result_warnings = []
  
    local_path = input_api.PresubmitLocalPath()
    root = xml.dom.minidom.parseString(stdout)
    for fileElement in root.getElementsByTagName('file'):
      fileName = fileElement.attributes['name'].value
      fileName = os.path.relpath(fileName, local_path)
      errors = fileElement.getElementsByTagName('error')
      for error in errors:
        line = error.attributes['line'].value
        column = ''
        if error.hasAttribute('column'):
          column = '%s:' % (error.attributes['column'].value)
        message = error.attributes['message'].value
        result = '  %s:%s:%s %s' % (fileName, line, column, message)
  
        severity = error.attributes['severity'].value
        if severity == 'error':
          result_errors.append(result)
        elif severity == 'warning':
          result_warnings.append(result)
  
    result = []
    if result_warnings:
      result.append(output_api.PresubmitPromptWarning('\n'.join(result_warnings)))
    if result_errors:
      result.append(output_api.PresubmitError('\n'.join(result_errors)))
    return result
  