[clang-tidy] skip check when not find compilation db (#56134)

tools/codestyle/clang-tidy.py

@@ -75,18 +75,19 @@ else:
     import queue
 
 
-def find_compilation_database(path):
+def find_compilation_database(path, result="./"):
     """Adjusts the directory until a compilation database is found."""
     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)
+            print('Warning: could not find compilation database.')
+            return None
         result += '../'
     return os.path.realpath(result)
 
 
 def make_absolute(f, directory):
+    """Convert a relative file path to an absolute file path."""
     if os.path.isabs(f):
         return f
     return os.path.normpath(os.path.join(directory, f))
@@ -216,6 +217,7 @@ def run_tidy(args, tmpdir, build_path, queue, lock, failed_files):
 
 
 def main():
+    """Runs clang-tidy over all files in a compilation database."""
     parser = argparse.ArgumentParser(
         description='Runs clang-tidy over all files '
         'in a compilation database. Requires '
@@ -317,9 +319,16 @@ def main():
 
     if args.build_path is not None:
         build_path = args.build_path
+        if not os.path.isfile(os.path.join(build_path, db_path)):
+            print(
+                f'Warning: could not find compilation database in {build_path}, skip clang-tidy check.'
+            )
+            build_path = None
     else:
         # Find our database
         build_path = find_compilation_database(db_path)
+    if build_path is None:
+        sys.exit(0)
 
     try:
         invocation = [args.clang_tidy_binary, '-list-checks']