Check for system include paths by looking at clang's HeaderSearchOptions,

tools/clang/translation_unit/test_translation_unit.py

 #!/usr/bin/env python
 # Copyright (c) 2014 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.
 
 """Test for TranslationUnitGenerator tool."""
 
 import difflib
 import glob
 import json
 import ntpath
 import os
 import os.path
 import subprocess
 import sys
 
 
-def _GenerateCompileCommands(files):
+def _GenerateCompileCommands(template_path, test_files_dir):
   """Returns a JSON string containing a compilation database for the input."""
-  return json.dumps([{'directory': '.',
-                      'command': 'clang++ -fsyntax-only -std=c++11 -c %s' % f,
-                      'file': f} for f in files], indent=2)
+  with open(template_path) as fh:
+    return fh.read().replace('$test_files_dir', test_files_dir)
 
 
 def _NumberOfTestsToString(tests):
   """Returns an English sentence describing the number of tests."""
   return "%d test%s" % (tests, 's' if tests != 1 else '')
 
 
 # Before running this test script, please build the translation_unit clang tool
 # first. This is explained here:
 # https://code.google.com/p/chromium/wiki/ClangToolRefactoring
 def main():
   tools_clang_directory = os.path.dirname(os.path.dirname(
       os.path.realpath(__file__)))
   tools_clang_scripts_directory = os.path.join(tools_clang_directory, 'scripts')
   test_directory_for_tool = os.path.join(
       tools_clang_directory, 'translation_unit', 'test_files')
   compile_database = os.path.join(test_directory_for_tool,
                                   'compile_commands.json')
+  compile_database_template = compile_database + '.template'
   source_files = glob.glob(os.path.join(test_directory_for_tool, '*.cc'))
 
   # Generate a temporary compilation database to run the tool over.
   with open(compile_database, 'w') as f:
-    f.write(_GenerateCompileCommands(source_files))
+    f.write(_GenerateCompileCommands(compile_database_template,
+                                     test_directory_for_tool))
 
   args = ['python',
           os.path.join(tools_clang_scripts_directory, 'run_tool.py'),
           'translation_unit',
           test_directory_for_tool]
   args.extend(source_files)
   run_tool = subprocess.Popen(args, stdout=subprocess.PIPE)
   stdout, _ = run_tool.communicate()
   if run_tool.returncode != 0:
     print 'run_tool failed:\n%s' % stdout
     sys.exit(1)
 
   passed = 0
   failed = 0
   for actual in source_files:
     actual += '.filepaths'
     expected = actual + '.expected'
     print '[ RUN      ] %s' % os.path.relpath(actual)
     expected_output = actual_output = None
     with open(expected, 'r') as f:
       expected_output = f.readlines()
     with open(actual, 'r') as f:
       actual_output = f.readlines()
     has_same_filepaths = True
     for expected_line, actual_line in zip(expected_output, actual_output):
-      if '//' in actual_output:
-        if actual_output.split('//')[1] != expected_output:
-          sys.stdout.write('expected: %s' % expected_output)
-          sys.stdout.write('actual: %s' % actual_output.split('//')[1])
-          break
-        else:
-          continue
+      if '//' in actual_line:
+        actual_line = '//' + actual_line.split('//')[1]
+
       if ntpath.basename(expected_line) != ntpath.basename(actual_line):
         sys.stdout.write('expected: %s' % ntpath.basename(expected_line))
         sys.stdout.write('actual: %s' % ntpath.basename(actual_line))
         has_same_filepaths = False
         break
     if not has_same_filepaths:
       failed += 1
       for line in difflib.unified_diff(expected_output, actual_output,
                                        fromfile=os.path.relpath(expected),
                                        tofile=os.path.relpath(actual)):
@@ skipping 11 matching lines @@
 
   print '[==========] %s ran.' % _NumberOfTestsToString(len(source_files))
   if passed > 0:
     print '[  PASSED  ] %s.' % _NumberOfTestsToString(passed)
   if failed > 0:
     print '[  FAILED  ] %s.' % _NumberOfTestsToString(failed)
 
 
 if __name__ == '__main__':
   sys.exit(main())