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

PRESUBMIT.py

Index: PRESUBMIT.py
diff --git a/PRESUBMIT.py b/PRESUBMIT.py
index e3ee9c4715bcf7cbc50c56129abb3f91ac142b0d..c3cd34114bd0351a5cb84a010e30733cdc953d92 100644
--- a/PRESUBMIT.py
+++ b/PRESUBMIT.py
@@ -374,6 +374,26 @@ def _CheckNoUNIT_TESTInSourceFiles(input_api, output_api):
       '\n'.join(problems))]
 
 
+def _CheckDCHECK_IS_ONHasBraces(input_api, output_api):
+  """Checks to make sure DCHECK_IS_ON() does not skip the braces"""

[ncarter (slow), 2015/10/23 20:39:02]

Nit: period at end of sentence per
https://www.python.org/dev/peps/pep-0257/#id16 (via the python style guide).

[danakj, 2015/10/23 21:53:16]

Done and fixed what I copied from.

+  files = []
+  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
+    contents = input_api.ReadFile(f)

[ncarter (slow), 2015/10/23 20:39:02]

Should this iterate over ChangedContents (the diff lines) instead of the whole
file?

[danakj, 2015/10/23 21:53:16]

Ya good point, copied from the UNIT_TEST one. Fixed.

+    if pattern.search(contents):
+      files.append(f)
+
+  if not files:
+    return []
+  return [ output_api.PresubmitError(
+      'Use of DCHECK_IS_ON() must be written as "#if DCHECK_IS_ON()", not '
+      'forgetting the braces.',
+      files) ]
+
+
 def _FindHistogramNameInLine(histogram_name, line):
   """Tries to find a histogram name or prefix in a line."""
   if not "affected-histogram" in line:
@@ -1640,6 +1660,7 @@ def _CommonChecks(input_api, output_api):
       _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))