[clang-tidy] Support relative paths in run-clang-tidy.py

[xazax.hun]

Summary

Currently, relative paths aren't supported by run-clang-tidy.py

I added the support, however, I did not find any existing tests. Is it ok for this to land without a test or should I introduce one?

[hokein]

The code looks good to me.

I did not find any existing tests.

Yeah, we don't have good test strategy for these py files. We normally verify them by running them locally. I think we can land it as long as you test it locally (would be better to describe how you test it in the commit message).

clang-tidy/tool/run-clang-tidy.py

232

nit: the code indention seems wrong here.

clang-tidy/tool/run-clang-tidy.py

def find_compilation_database(path):
   result = './'
   while not os.path.isfile(os.path.join(result, path)):
     if os.path.realpath(result) == '/':
       print('Error: could not find compilation database.')
       sys.exit(1)
     result += '../'
   return os.path.realpath(result)
 
+def make_absolute(f, directory):
+  if os.path.isabs(f):
+    return f
+  return os.path.normpath(os.path.join(directory, f))
+
 
 def get_tidy_invocation(f, clang_tidy_binary, checks, tmpdir, build_path,
                         header_filter, extra_arg, extra_arg_before, quiet):
   """Gets a command line for clang-tidy."""
   start = [clang_tidy_binary]
   if header_filter is not None:
     start.append('-header-filter=' + header_filter)
   else:
try:
     invocation.append('-')
     print(subprocess.check_output(invocation))
   except:
     print("Unable to run clang-tidy.", file=sys.stderr)
     sys.exit(1)
 
   # Load the database and extract all files.
   database = json.load(open(os.path.join(build_path, db_path)))
-  files = [entry['file'] for entry in database]
+  files = [make_absolute(entry['file'], entry['directory'])
+          for entry in database]
 
   max_task = args.j
   if max_task == 0:
     max_task = multiprocessing.cpu_count()
 
   tmpdir = None
   if args.fix or args.export_fixes:
     check_clang_apply_replacements_binary(args)