[#2] Pass gfx structs by const ref (gfx::Rect, gfx::RectF)

cc/PRESUBMIT.py

 # Copyright (c) 2012 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.
 
 """Top-level presubmit script for cc.
 
 See http://dev.chromium.org/developers/how-tos/depottools/presubmit-scripts for
 details on the presubmit API built into gcl.
 """
 
 import re
-import string
 
 CC_SOURCE_FILES=(r'^cc/.*\.(cc|h)$',)
 
 def CheckChangeLintsClean(input_api, output_api):
   input_api.cpplint._cpplint_state.ResetErrorCounts()  # reset global state
   source_filter = lambda x: input_api.FilterSourceFile(
     x, white_list=CC_SOURCE_FILES, black_list=None)
   files = [f.AbsoluteLocalPath() for f in
            input_api.AffectedSourceFiles(source_filter)]
   level = 1  # strict, but just warn
@@ skipping 72 matching lines @@
     result.append(output_api.PresubmitError(
         'std::abs() should be used instead of std::fabs() for consistency.',
         items=found_fabs_files))
   if missing_std_prefix_files:
     result.append(output_api.PresubmitError(
         'These files use abs(), absf(), fabs(), or fabsf() without qualifying '
         'the std namespace. Please use std::abs() in all places.',
         items=missing_std_prefix_files))
   return result
 
-def CheckPassByValue(input_api,

[enne (OOO), 2014/01/02 18:42:56]

The presubmit here was nice because it communicated to everyone what was desired
without having to depend on code review to catch it.

Do you think it'd be plausible to come up with something that could check
headers for "gfx::Rect identifier" inside of parentheses that aren't "const
gfx::Rect& identifier"?

-                     output_api,
-                     white_list=CC_SOURCE_FILES,
-                     black_list=None):
-  black_list = tuple(black_list or input_api.DEFAULT_BLACK_LIST)
-  source_file_filter = lambda x: input_api.FilterSourceFile(x,
-                                                            white_list,
-                                                            black_list)
-
-  local_errors = []
-
-  # Well-defined simple classes containing only <= 4 ints, or <= 2 floats.
-  pass_by_value_types = ['base::Time',
-                         'base::TimeTicks',
-                         'gfx::Point',
-                         'gfx::PointF',
-                         'gfx::Rect',
-                         'gfx::Size',
-                         'gfx::SizeF',
-                         'gfx::Vector2d',
-                         'gfx::Vector2dF',
-                         ]
-
-  for f in input_api.AffectedSourceFiles(source_file_filter):
-    contents = input_api.ReadFile(f, 'rb')
-    match = re.search(
-      r'\bconst +' + '(?P<type>(%s))&' %
-        string.join(pass_by_value_types, '|'),
-      contents)
-    if match:
-      local_errors.append(output_api.PresubmitError(
-        '%s passes %s by const ref instead of by value.' %
-        (f.LocalPath(), match.group('type'))))
-  return local_errors
-
 def CheckTodos(input_api, output_api):
   errors = []
 
   source_file_filter = lambda x: x
   for f in input_api.AffectedSourceFiles(source_file_filter):
     contents = input_api.ReadFile(f, 'rb')
     if ('FIX'+'ME') in contents:
       errors.append(f.LocalPath())
 
   if errors:
     return [output_api.PresubmitError(
       'All TODO comments should be of the form TODO(name).',
       items=errors)]
   return []
 
 
 def CheckChangeOnUpload(input_api, output_api):
   results = []
   results += CheckAsserts(input_api, output_api)
   results += CheckStdAbs(input_api, output_api)
-  results += CheckPassByValue(input_api, output_api)
   results += CheckChangeLintsClean(input_api, output_api)
   results += CheckTodos(input_api, output_api)
   return results
 
 def GetPreferredTrySlaves(project, change):
   return [
     'linux_layout_rel',
     'win_gpu',
     'linux_gpu',
     'mac_gpu',
     'mac_gpu_retina',
     ]