Virtual functions now take Option<Gd<T>> instead of Gd<T>

Sometimes inconvenient, but the only way if no nullability information
is provided. Exceptions can be worked out over time.

Author: Bromeon

godot-codegen/src/generator/functions_common.rs

@@ -322,8 +322,8 @@ pub(crate) fn make_params_exprs<'a>(
         let param_name = &param.name;
         let param_ty = &param.type_;
 
-        // Objects (Gd<T>) use implicit conversions via AsObjectArg. Only use in non-virtual functions.
         match &param.type_ {
+            // Non-virtual functions: Objects (Gd<T>) use implicit conversions via AsObjectArg.
             RustTy::EngineClass {
                 object_arg,
                 impl_as_object_arg,
@@ -346,6 +346,14 @@ pub(crate) fn make_params_exprs<'a>(
                 param_types.push(quote! { #object_arg });
             }
 
+            // Virtual methods accept Option<Gd<T>>, since we don't know whether objects are nullable or required.
+            RustTy::EngineClass { .. } if is_virtual => {
+                params.push(quote! { #param_name: Option<#param_ty> });
+                arg_names.push(quote! { #param_name });
+                param_types.push(quote! { #param_ty });
+            }
+
+            // All other methods and parameter types: standard handling.
             _ => {
                 params.push(quote! { #param_name: #param_ty });
                 arg_names.push(quote! { #param_name });

itest/rust/src/object_tests/virtual_methods_test.rs

@@ -153,12 +153,12 @@ impl IPrimitiveMesh for VirtualReturnTest {
     fn surface_get_format(&self, _index: i32) -> u32 { unreachable!() }
     fn surface_get_primitive_type(&self, _index: i32) -> u32 { unreachable!() }
     #[cfg(feature = "codegen-full")]
-    fn surface_set_material(&mut self, _index: i32, _material: Gd<Material>) { unreachable!() }
+    fn surface_set_material(&mut self, _index: i32, _material: Option<Gd<Material>>) { unreachable!() }
     #[cfg(feature = "codegen-full")]
     fn surface_get_material(&self, _index: i32) -> Option<Gd<Material>> { unreachable!() }
     fn get_blend_shape_count(&self) -> i32 { unreachable!() }
     fn get_blend_shape_name(&self, _index: i32) -> StringName { unreachable!() }
-    fn set_blend_shape_name(&mut self, _index: i32, _namee: StringName) { unreachable!() }
+    fn set_blend_shape_name(&mut self, _index: i32, _name: StringName) { unreachable!() }
     fn get_aabb(&self) -> godot::prelude::Aabb { unreachable!() }
 }