Add backend methods for process own arguments

backend.py

@@ -1,3 +1,4 @@
+import argparse
 import inspect
 import os
 import pkgutil
@@ -33,6 +34,12 @@ def __init__(self):
 
         self.register_implementations()
 
+    def get_arguments() -> argparse.ArgumentParser:
+        return argparse.ArgumentParser(add_help=False)
+
+    def process_arguments(self, args=dict[str, str]):
+        pass
+
     def register_implementations(self):
         self.implementations = self.get_implementations()
 
@@ -106,6 +113,16 @@ class CppBackend(Backend):
     name = "cpp"
     path_to_templates = "cpp/"
     builtin_messages = ["Int8", "Int16", "Int32", "Int64"]
+    use_highlevel_api = False
+
+    @classmethod
+    def get_arguments(cls) -> argparse.ArgumentParser:
+        parser = super().get_arguments()
+        parser.add_argument('-hl', '--highlevel-api', help="Enable highlevel API", action='store_true')
+        return parser
+
+    def process_arguments(self, args):
+        self.use_highlevel_api = args['highlevel_api']
 
     def render_message(self, message:  messages_base.Message):
         return super().render_message(message)

mess.py

@@ -1,5 +1,6 @@
 import argparse
 import inspect
+import sys
 
 from generator import Generator     
 import backend
@@ -13,7 +14,14 @@
                 continue
             backends[klass.name] = klass
 
-    parser = argparse.ArgumentParser(description="Optional app description")
+    # Trick for add backend specific arguments
+    parser_parents = []
+    if len(sys.argv) > 1:
+        cur_backend = backends.get(sys.argv[1], None)
+        if cur_backend is not None:
+            parser_parents.append(cur_backend.get_arguments())
+
+    parser = argparse.ArgumentParser(description="Optional app description", parents=parser_parents)
 
     # Required positional argument
     parser.add_argument("backend", type=str, help="Backend, one from the list", choices=backends.keys())
@@ -24,7 +32,8 @@
     args = vars(parser.parse_args())
 
     selected_backend = backends[args["backend"]]()
-    generator = Generator(selected_backend)
+    selected_backend.process_arguments(args)
 
+    generator = Generator(selected_backend)
     generator.load_file(args["in"])
     generator.write_to_file(args["out"])