Presubmit enforce that DCHECK_IS_ON() does not forget the braces.

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 Chromium.
 
 See http://dev.chromium.org/developers/how-tos/depottools/presubmit-scripts
 for more details about the presubmit API built into depot_tools.
 """
 
@@ skipping 340 matching lines @@
   if len(files):
     return [ output_api.PresubmitError(
         'Do not #include <iostream> in header files, since it inserts static '
         'initialization into every file including the header. Instead, '
         '#include <ostream>. See http://crbug.com/94794',
         files) ]
   return []
 
 
 def _CheckNoUNIT_TESTInSourceFiles(input_api, output_api):
-  """Checks to make sure no source files use UNIT_TEST"""
+  """Checks to make sure no source files use UNIT_TEST."""
   problems = []
   for f in input_api.AffectedFiles():
     if (not f.LocalPath().endswith(('.cc', '.mm'))):
       continue
 
     for line_num, line in f.ChangedContents():
       if 'UNIT_TEST ' in line or line.endswith('UNIT_TEST'):
         problems.append('    %s:%d' % (f.LocalPath(), line_num))
 
   if not problems:
     return []
   return [output_api.PresubmitPromptWarning('UNIT_TEST is only for headers.\n' +
       '\n'.join(problems))]
 
 
+def _CheckDCHECK_IS_ONHasBraces(input_api, output_api):
+  """Checks to make sure DCHECK_IS_ON() does not skip the braces."""
+  errors = []
+  pattern = input_api.re.compile(r'DCHECK_IS_ON(?!\(\))',
+                                 input_api.re.MULTILINE)
+  for f in input_api.AffectedSourceFiles(input_api.FilterSourceFile):
+    if (not f.LocalPath().endswith(('.cc', '.mm', '.h'))):
+      continue
+    for lnum, line in f.ChangedContents():
+      if input_api.re.search(pattern, line):
+          errors.append(output_api.PresubmitError(
+            ('%s:%d: Use of DCHECK_IS_ON() must be written as "#if ' +

[danakj, 2015/10/23 21:53:42]

The error is nicer now too :)

+             'DCHECK_IS_ON()", not forgetting the braces.')

[kjellander_chromium, 2017/02/20 07:09:48]

Shouldn't 'braces' be replaced by 'parentheses' or am I missing something?
See http://practicaltypography.com/parentheses-brackets-and-braces.html

[danakj, 2017/02/22 00:19:54]

You can submit a CL to fix it if you want :)

+            % (f.LocalPath(), lnum)))
+  return errors
+
+
 def _FindHistogramNameInLine(histogram_name, line):
   """Tries to find a histogram name or prefix in a line."""
   if not "affected-histogram" in line:
     return histogram_name in line
   # A histogram_suffixes tag type has an affected-histogram name as a prefix of
   # the histogram_name.
   if not '"' in line:
     return False
   histogram_prefix = line.split('\"')[1]
   return histogram_prefix in histogram_name
@@ skipping 1246 matching lines @@
   """Checks common to both upload and commit."""
   results = []
   results.extend(input_api.canned_checks.PanProjectChecks(
       input_api, output_api,
       excluded_paths=_EXCLUDED_PATHS + _TESTRUNNER_PATHS))
   results.extend(_CheckAuthorizedAuthor(input_api, output_api))
   results.extend(
       _CheckNoProductionCodeUsingTestOnlyFunctions(input_api, output_api))
   results.extend(_CheckNoIOStreamInHeaders(input_api, output_api))
   results.extend(_CheckNoUNIT_TESTInSourceFiles(input_api, output_api))
+  results.extend(_CheckDCHECK_IS_ONHasBraces(input_api, output_api))
   results.extend(_CheckNoNewWStrings(input_api, output_api))
   results.extend(_CheckNoDEPSGIT(input_api, output_api))
   results.extend(_CheckNoBannedFunctions(input_api, output_api))
   results.extend(_CheckNoPragmaOnce(input_api, output_api))
   results.extend(_CheckNoTrinaryTrueFalse(input_api, output_api))
   results.extend(_CheckUnwantedDependencies(input_api, output_api))
   results.extend(_CheckFilePermissions(input_api, output_api))
   results.extend(_CheckNoAuraWindowPropertyHInHeaders(input_api, output_api))
   results.extend(_CheckIncludeOrder(input_api, output_api))
   results.extend(_CheckForVersionControlConflicts(input_api, output_api))
@@ skipping 326 matching lines @@
   for master in masters:
     try_config.setdefault(master, {})
     for builder in masters[master]:
       # Do not trigger presubmit builders, since they're likely to fail
       # (e.g. OWNERS checks before finished code review), and we're
       # running local presubmit anyway.
       if 'presubmit' not in builder:
         try_config[master][builder] = ['defaulttests']
 
   return try_config