Codegen: parse synth property modifier

misc/codegen/lib/schemadefs.py

@@ -44,10 +44,15 @@ class _Namespace:
         self.__dict__.update(kwargs)
 
 
+class _SynthModifier(_schema.PropertyModifier, _Namespace):
+    def modify(self, prop: _schema.Property):
+        prop.synth = True
+
+
 qltest = _Namespace()
 ql = _Namespace()
 cpp = _Namespace()
-synth = _Namespace()
+synth = _SynthModifier()
 
 
 @_dataclass

misc/codegen/test/test_schemaloader.py

@@ -455,6 +455,17 @@ def test_ipa_class_hierarchy():
     }
 
 
+def test_synthesized_property():
+    @load
+    class data:
+        class A:
+            x: defs.int | defs.synth
+
+    assert data.classes["A"].properties == [
+        schema.SingleProperty("x", "int", synth=True)
+    ]
+
+
 def test_class_docstring():
     @load
     class data: