Merge "conv_linker_config proto works with empty input"

scripts/conv_linker_config.py

@@ -28,6 +28,7 @@ from google.protobuf.text_format import MessageToString
 
 def Proto(args):
     pb = linker_config_pb2.LinkerConfig()
+    if args.source:
         for input in args.source.split(':'):
             json_content = ''
             with open(input) as f:
@@ -104,7 +105,7 @@ def GetArgParser():
     parser_proto.add_argument(
         '-s',
         '--source',
-        required=True,
+        nargs='?',
         type=str,
         help='Colon-separated list of linker configuration files in JSON.')
     parser_proto.add_argument(