Cleanup gms update/preprocess scripts, roll android_tools

build/android/pylib/utils/argparse_utils.py

+# Copyright 2015 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 argparse
+
+
+class CustomHelpAction(argparse.Action):

[jbudorick, 2015/12/10 14:16:31]

Sweet!

+  '''
+  Allows defining custom help actions. Help actions can run even when the

[jbudorick, 2015/12/10 14:16:31]

nit: docstrings should be

'''Summary sentence.

More detailed description.
'''

[dgn, 2015/12/10 21:12:57]

Done.

+  parser would otherwise fail on missing arguments. The first help or custom
+  help command mentioned on the command line will have its help text displayed.
+
+  Usage:
+      parser = argparse.ArgumentParser(...)
+      CustomHelpAction.EnableFor(parser)
+      parser.add_argument('--foo-help',
+                          action='custom_help',
+                          custom_help_text='this is the help message',
+                          help='What this helps with')
+  '''
+  # Derived from argparse._HelpAction from
+  # https://github.com/python/cpython/blob/master/Lib/argparse.py
+
+  # pylint: disable=redefined-builtin
+  # (complains about 'help' being redefined)
+  def __init__(self,
+               option_strings,
+               dest=argparse.SUPPRESS,
+               default=argparse.SUPPRESS,
+               custom_help_text=None,
+               help=None):
+    super(CustomHelpAction, self).__init__(option_strings=option_strings,
+                                           dest=dest,
+                                           default=default,
+                                           nargs=0,
+                                           help=help)
+
+    if not custom_help_text:
+      raise ValueError('custom_help_text is required')
+    self._help_text = custom_help_text
+
+  def __call__(self, parser, namespace, values, option_string=None):
+    print self._help_text
+    parser.exit()
+
+  @staticmethod
+  def EnableFor(parser):
+    parser.register('action', 'custom_help', CustomHelpAction)