supersize: Add "diff" command

tools/binary_size/libsupersize/main.py

 #!/usr/bin/env python
 # Copyright 2017 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.
 
 """Collect, archive, and analyze Chrome's binary size."""
 
 import argparse
 import atexit
 import collections
@@ skipping 18 matching lines @@
 def _AddCommonArguments(parser):
   parser.add_argument('--no-pypy', action='store_true',
                       help='Do not automatically switch to pypy when available')
   parser.add_argument('-v',
                       '--verbose',
                       default=0,
                       action='count',
                       help='Verbose level (multiple times for more)')
 
 
+class _DiffAction(object):
+  @staticmethod
+  def AddArguments(parser):
+    parser.add_argument('before', help='Before-patch .size file.')
+    parser.add_argument('after', help='After-patch .size file.')
+    parser.add_argument('--all', action='store_true', help='Verbose diff')
+
+  @staticmethod
+  def Run(args, parser):
+    args.output_directory = None
+    args.tool_prefix = None
+    args.inputs = [args.before, args.after]
+    args.query = ('Print(Diff(size_info1, size_info2), verbose=%s)' %
+                  bool(args.all))
+    console.Run(args, parser)
+
+
 def main():
   parser = argparse.ArgumentParser(description=__doc__)
   sub_parsers = parser.add_subparsers()
   actions = collections.OrderedDict()
   actions['archive'] = (archive, 'Create a .size file')
   actions['html_report'] = (
       html_report, 'Create a stand-alone html report from a .size file.')
   actions['console'] = (
       console,
       'Starts an interactive Python console for analyzing .size files.')
+  actions['diff'] = (
+      _DiffAction(),
+      'Shorthand for console --query "Print(Diff(size_info1, size_info2))"')
 
   for name, tup in actions.iteritems():
     sub_parser = sub_parsers.add_parser(name, help=tup[1])
     _AddCommonArguments(sub_parser)
     tup[0].AddArguments(sub_parser)
     sub_parser.set_defaults(func=tup[0].Run)
 
   if len(sys.argv) == 1:
     parser.print_help()
     sys.exit(1)
@@ skipping 15 matching lines @@
     logging.warning('This script runs more than 2x faster if you install pypy.')
 
   if logging.getLogger().isEnabledFor(logging.DEBUG):
     atexit.register(_LogPeakRamUsage)
 
   args.func(args, parser)
 
 
 if __name__ == '__main__':
   sys.exit(main())