Change exit code of clang-format (#192)

Because clang-format always returns an exit code of 0,
We must check the output of the clang-format as a law string
and re-returns exit code 0 or 1.

So I would like to change clang-format exit code.
- There is no need to change format (exit 0).
- There is need to change format (exit 1).

Finally, I want to contribute this to the upstream.

ISSUE=#191

bootstrap/command/lint

@@ -16,20 +16,4 @@
 
 . $BACARDI_PATH/bootstrap/common/path_info.sh
 
-format_diff="$(bootstrap_command_path)/format --diff"
-
-function need_to_format() {
-  result=$($format_diff)
-  if [ "$result" = "no modified files to format" ] \
-      || [ "$result" = "clang-format did not modify any files" ]; then
-    return 1
-  else
-    $format_diff
-    return 0
-  fi
-}
-
-if need_to_format; then
-  echo "lint error: You can fix the lint error with |bacardi format| command."
-  exit 1
-fi
+$(bootstrap_command_path)/format --diff

third_party/clang-format/git-clang-format

@@ -171,6 +171,9 @@ def main():
       print('clang-format did not modify any files')
   elif opts.diff:
     print_diff(old_tree, new_tree)
+    # FIXME(yjaeseok): change exit code of clang-format.
+    # If there is a difference with clang-format we should return failure.
+    sys.exit(1)
   else:
     changed_files = apply_changes(old_tree, new_tree, force=opts.force,
                                   patch_mode=opts.patch)