Improve extension system

- Fix library loading and initialization.
- Add extra methods/parameters in the interface needed by extenstions.
- Add Variant destructors and functions for extracting values and
  creating Variants from values.

core/extension/extension_api_dump.cpp

@@ -559,6 +559,10 @@ Dictionary NativeExtensionAPIDump::generate_extension_api() {
 					d["constructors"] = constructors;
 				}
 			}
+			{
+				//destructor
+				d["has_destructor"] = Variant::has_destructor(type);
+			}
 
 			builtins.push_back(d);
 		}

core/extension/gdnative_interface.cpp

@@ -299,6 +299,161 @@ static GDNativeBool gdnative_variant_can_convert_strict(GDNativeVariantType p_fr
 	return Variant::can_convert_strict((Variant::Type)p_from, (Variant::Type)p_to);
 }
 
+// Variant interaction.
+static GDNativeVariantFromTypeConstructorFunc gdnative_get_variant_from_type_constructor(GDNativeVariantType p_type) {
+	switch (p_type) {
+		case GDNATIVE_VARIANT_TYPE_BOOL:
+			return VariantTypeConstructor<bool>::variant_from_type;
+		case GDNATIVE_VARIANT_TYPE_INT:
+			return VariantTypeConstructor<int64_t>::variant_from_type;
+		case GDNATIVE_VARIANT_TYPE_FLOAT:
+			return VariantTypeConstructor<double>::variant_from_type;
+		case GDNATIVE_VARIANT_TYPE_STRING:
+			return VariantTypeConstructor<String>::variant_from_type;
+		case GDNATIVE_VARIANT_TYPE_VECTOR2:
+			return VariantTypeConstructor<Vector2>::variant_from_type;
+		case GDNATIVE_VARIANT_TYPE_VECTOR2I:
+			return VariantTypeConstructor<Vector2i>::variant_from_type;
+		case GDNATIVE_VARIANT_TYPE_RECT2:
+			return VariantTypeConstructor<Rect2>::variant_from_type;
+		case GDNATIVE_VARIANT_TYPE_RECT2I:
+			return VariantTypeConstructor<Rect2i>::variant_from_type;
+		case GDNATIVE_VARIANT_TYPE_VECTOR3:
+			return VariantTypeConstructor<Vector3>::variant_from_type;
+		case GDNATIVE_VARIANT_TYPE_VECTOR3I:
+			return VariantTypeConstructor<Vector3i>::variant_from_type;
+		case GDNATIVE_VARIANT_TYPE_TRANSFORM2D:
+			return VariantTypeConstructor<Transform2D>::variant_from_type;
+		case GDNATIVE_VARIANT_TYPE_PLANE:
+			return VariantTypeConstructor<Plane>::variant_from_type;
+		case GDNATIVE_VARIANT_TYPE_QUATERNION:
+			return VariantTypeConstructor<Quaternion>::variant_from_type;
+		case GDNATIVE_VARIANT_TYPE_AABB:
+			return VariantTypeConstructor<AABB>::variant_from_type;
+		case GDNATIVE_VARIANT_TYPE_BASIS:
+			return VariantTypeConstructor<Basis>::variant_from_type;
+		case GDNATIVE_VARIANT_TYPE_TRANSFORM3D:
+			return VariantTypeConstructor<Transform3D>::variant_from_type;
+		case GDNATIVE_VARIANT_TYPE_COLOR:
+			return VariantTypeConstructor<Color>::variant_from_type;
+		case GDNATIVE_VARIANT_TYPE_STRING_NAME:
+			return VariantTypeConstructor<StringName>::variant_from_type;
+		case GDNATIVE_VARIANT_TYPE_NODE_PATH:
+			return VariantTypeConstructor<NodePath>::variant_from_type;
+		case GDNATIVE_VARIANT_TYPE_RID:
+			return VariantTypeConstructor<RID>::variant_from_type;
+		case GDNATIVE_VARIANT_TYPE_OBJECT:
+			return VariantTypeConstructor<Object *>::variant_from_type;
+		case GDNATIVE_VARIANT_TYPE_CALLABLE:
+			return VariantTypeConstructor<Callable>::variant_from_type;
+		case GDNATIVE_VARIANT_TYPE_SIGNAL:
+			return VariantTypeConstructor<Signal>::variant_from_type;
+		case GDNATIVE_VARIANT_TYPE_DICTIONARY:
+			return VariantTypeConstructor<Dictionary>::variant_from_type;
+		case GDNATIVE_VARIANT_TYPE_ARRAY:
+			return VariantTypeConstructor<Array>::variant_from_type;
+		case GDNATIVE_VARIANT_TYPE_PACKED_BYTE_ARRAY:
+			return VariantTypeConstructor<PackedByteArray>::variant_from_type;
+		case GDNATIVE_VARIANT_TYPE_PACKED_INT32_ARRAY:
+			return VariantTypeConstructor<PackedInt32Array>::variant_from_type;
+		case GDNATIVE_VARIANT_TYPE_PACKED_INT64_ARRAY:
+			return VariantTypeConstructor<PackedInt64Array>::variant_from_type;
+		case GDNATIVE_VARIANT_TYPE_PACKED_FLOAT32_ARRAY:
+			return VariantTypeConstructor<PackedFloat32Array>::variant_from_type;
+		case GDNATIVE_VARIANT_TYPE_PACKED_FLOAT64_ARRAY:
+			return VariantTypeConstructor<PackedFloat64Array>::variant_from_type;
+		case GDNATIVE_VARIANT_TYPE_PACKED_STRING_ARRAY:
+			return VariantTypeConstructor<PackedStringArray>::variant_from_type;
+		case GDNATIVE_VARIANT_TYPE_PACKED_VECTOR2_ARRAY:
+			return VariantTypeConstructor<PackedVector2Array>::variant_from_type;
+		case GDNATIVE_VARIANT_TYPE_PACKED_VECTOR3_ARRAY:
+			return VariantTypeConstructor<PackedVector3Array>::variant_from_type;
+		case GDNATIVE_VARIANT_TYPE_PACKED_COLOR_ARRAY:
+			return VariantTypeConstructor<PackedColorArray>::variant_from_type;
+		case GDNATIVE_VARIANT_TYPE_NIL:
+		case GDNATIVE_VARIANT_TYPE_VARIANT_MAX:
+			ERR_FAIL_V_MSG(nullptr, "Getting Variant conversion function with invalid type");
+	}
+	ERR_FAIL_V_MSG(nullptr, "Getting Variant conversion function with invalid type");
+}
+
+static GDNativeTypeFromVariantConstructorFunc gdnative_get_type_from_variant_constructor(GDNativeVariantType p_type) {
+	switch (p_type) {
+		case GDNATIVE_VARIANT_TYPE_BOOL:
+			return VariantTypeConstructor<bool>::type_from_variant;
+		case GDNATIVE_VARIANT_TYPE_INT:
+			return VariantTypeConstructor<int64_t>::type_from_variant;
+		case GDNATIVE_VARIANT_TYPE_FLOAT:
+			return VariantTypeConstructor<double>::type_from_variant;
+		case GDNATIVE_VARIANT_TYPE_STRING:
+			return VariantTypeConstructor<String>::type_from_variant;
+		case GDNATIVE_VARIANT_TYPE_VECTOR2:
+			return VariantTypeConstructor<Vector2>::type_from_variant;
+		case GDNATIVE_VARIANT_TYPE_VECTOR2I:
+			return VariantTypeConstructor<Vector2i>::type_from_variant;
+		case GDNATIVE_VARIANT_TYPE_RECT2:
+			return VariantTypeConstructor<Rect2>::type_from_variant;
+		case GDNATIVE_VARIANT_TYPE_RECT2I:
+			return VariantTypeConstructor<Rect2i>::type_from_variant;
+		case GDNATIVE_VARIANT_TYPE_VECTOR3:
+			return VariantTypeConstructor<Vector3>::type_from_variant;
+		case GDNATIVE_VARIANT_TYPE_VECTOR3I:
+			return VariantTypeConstructor<Vector3i>::type_from_variant;
+		case GDNATIVE_VARIANT_TYPE_TRANSFORM2D:
+			return VariantTypeConstructor<Transform2D>::type_from_variant;
+		case GDNATIVE_VARIANT_TYPE_PLANE:
+			return VariantTypeConstructor<Plane>::type_from_variant;
+		case GDNATIVE_VARIANT_TYPE_QUATERNION:
+			return VariantTypeConstructor<Quaternion>::type_from_variant;
+		case GDNATIVE_VARIANT_TYPE_AABB:
+			return VariantTypeConstructor<AABB>::type_from_variant;
+		case GDNATIVE_VARIANT_TYPE_BASIS:
+			return VariantTypeConstructor<Basis>::type_from_variant;
+		case GDNATIVE_VARIANT_TYPE_TRANSFORM3D:
+			return VariantTypeConstructor<Transform3D>::type_from_variant;
+		case GDNATIVE_VARIANT_TYPE_COLOR:
+			return VariantTypeConstructor<Color>::type_from_variant;
+		case GDNATIVE_VARIANT_TYPE_STRING_NAME:
+			return VariantTypeConstructor<StringName>::type_from_variant;
+		case GDNATIVE_VARIANT_TYPE_NODE_PATH:
+			return VariantTypeConstructor<NodePath>::type_from_variant;
+		case GDNATIVE_VARIANT_TYPE_RID:
+			return VariantTypeConstructor<RID>::type_from_variant;
+		case GDNATIVE_VARIANT_TYPE_OBJECT:
+			return VariantTypeConstructor<Object *>::type_from_variant;
+		case GDNATIVE_VARIANT_TYPE_CALLABLE:
+			return VariantTypeConstructor<Callable>::type_from_variant;
+		case GDNATIVE_VARIANT_TYPE_SIGNAL:
+			return VariantTypeConstructor<Signal>::type_from_variant;
+		case GDNATIVE_VARIANT_TYPE_DICTIONARY:
+			return VariantTypeConstructor<Dictionary>::type_from_variant;
+		case GDNATIVE_VARIANT_TYPE_ARRAY:
+			return VariantTypeConstructor<Array>::type_from_variant;
+		case GDNATIVE_VARIANT_TYPE_PACKED_BYTE_ARRAY:
+			return VariantTypeConstructor<PackedByteArray>::type_from_variant;
+		case GDNATIVE_VARIANT_TYPE_PACKED_INT32_ARRAY:
+			return VariantTypeConstructor<PackedInt32Array>::type_from_variant;
+		case GDNATIVE_VARIANT_TYPE_PACKED_INT64_ARRAY:
+			return VariantTypeConstructor<PackedInt64Array>::type_from_variant;
+		case GDNATIVE_VARIANT_TYPE_PACKED_FLOAT32_ARRAY:
+			return VariantTypeConstructor<PackedFloat32Array>::type_from_variant;
+		case GDNATIVE_VARIANT_TYPE_PACKED_FLOAT64_ARRAY:
+			return VariantTypeConstructor<PackedFloat64Array>::type_from_variant;
+		case GDNATIVE_VARIANT_TYPE_PACKED_STRING_ARRAY:
+			return VariantTypeConstructor<PackedStringArray>::type_from_variant;
+		case GDNATIVE_VARIANT_TYPE_PACKED_VECTOR2_ARRAY:
+			return VariantTypeConstructor<PackedVector2Array>::type_from_variant;
+		case GDNATIVE_VARIANT_TYPE_PACKED_VECTOR3_ARRAY:
+			return VariantTypeConstructor<PackedVector3Array>::type_from_variant;
+		case GDNATIVE_VARIANT_TYPE_PACKED_COLOR_ARRAY:
+			return VariantTypeConstructor<PackedColorArray>::type_from_variant;
+		case GDNATIVE_VARIANT_TYPE_NIL:
+		case GDNATIVE_VARIANT_TYPE_VARIANT_MAX:
+			ERR_FAIL_V_MSG(nullptr, "Getting Variant conversion function with invalid type");
+	}
+	ERR_FAIL_V_MSG(nullptr, "Getting Variant conversion function with invalid type");
+}
+
 // ptrcalls
 static GDNativePtrOperatorEvaluator gdnative_variant_get_ptr_operator_evaluator(GDNativeVariantOperator p_operator, GDNativeVariantType p_type_a, GDNativeVariantType p_type_b) {
 	return (GDNativePtrOperatorEvaluator)Variant::get_ptr_operator_evaluator(Variant::Operator(p_operator), Variant::Type(p_type_a), Variant::Type(p_type_b));
@@ -316,6 +471,9 @@ static GDNativePtrBuiltInMethod gdnative_variant_get_ptr_builtin_method(GDNative
 static GDNativePtrConstructor gdnative_variant_get_ptr_constructor(GDNativeVariantType p_type, int32_t p_constructor) {
 	return (GDNativePtrConstructor)Variant::get_ptr_constructor(Variant::Type(p_type), p_constructor);
 }
+static GDNativePtrDestructor gdnative_variant_get_ptr_destructor(GDNativeVariantType p_type) {
+	return (GDNativePtrDestructor)Variant::get_ptr_destructor(Variant::Type(p_type));
+}
 static void gdnative_variant_construct(GDNativeVariantType p_type, GDNativeVariantPtr p_base, const GDNativeVariantPtr *p_args, int32_t p_argument_count, GDNativeCallError *r_error) {
 	memnew_placement(p_base, Variant);
 
@@ -521,11 +679,16 @@ static GDNativeObjectPtr gdnative_global_get_singleton(const char *p_name) {
 	return (GDNativeObjectPtr)Engine::get_singleton()->get_singleton_object(String(p_name));
 }
 
-static void *gdnative_object_get_instance_binding(GDNativeObjectPtr p_instance, void *p_token, GDNativeInstanceBindingCallbacks *p_callbacks) {
+static void *gdnative_object_get_instance_binding(GDNativeObjectPtr p_instance, void *p_token, const GDNativeInstanceBindingCallbacks *p_callbacks) {
 	Object *o = (Object *)p_instance;
 	return o->get_instance_binding(p_token, p_callbacks);
 }
 
+static void gdnative_object_set_instance_binding(GDNativeObjectPtr p_instance, void *p_token, void *p_binding, const GDNativeInstanceBindingCallbacks *p_callbacks) {
+	Object *o = (Object *)p_instance;
+	o->set_instance_binding(p_token, p_binding, p_callbacks);
+}
+
 static GDNativeObjectPtr gdnative_object_get_instance_from_id(GDObjectInstanceID p_instance_id) {
 	return (GDNativeObjectPtr)ObjectDB::get_instance(ObjectID(p_instance_id));
 }
@@ -626,15 +789,15 @@ void gdnative_setup_interface(GDNativeInterface *p_interface) {
 	gdni.variant_can_convert = gdnative_variant_can_convert;
 	gdni.variant_can_convert_strict = gdnative_variant_can_convert_strict;
 
-	//ptrcalls
-#if 0
-	GDNativeVariantFromTypeConstructorFunc (*get_variant_from_type_constructor)(GDNativeVariantType p_type);
-	GDNativeTypeFromVariantConstructorFunc (*get_variant_to_type_constructor)(GDNativeVariantType p_type);
-#endif
+	gdni.get_variant_from_type_constructor = gdnative_get_variant_from_type_constructor;
+	gdni.get_variant_to_type_constructor = gdnative_get_type_from_variant_constructor;
+
+	// ptrcalls.
 
 	gdni.variant_get_ptr_operator_evaluator = gdnative_variant_get_ptr_operator_evaluator;
 	gdni.variant_get_ptr_builtin_method = gdnative_variant_get_ptr_builtin_method;
 	gdni.variant_get_ptr_constructor = gdnative_variant_get_ptr_constructor;
+	gdni.variant_get_ptr_destructor = gdnative_variant_get_ptr_destructor;
 	gdni.variant_construct = gdnative_variant_construct;
 	gdni.variant_get_ptr_setter = gdnative_variant_get_ptr_setter;
 	gdni.variant_get_ptr_getter = gdnative_variant_get_ptr_getter;
@@ -672,6 +835,7 @@ void gdnative_setup_interface(GDNativeInterface *p_interface) {
 	gdni.object_destroy = gdnative_object_destroy;
 	gdni.global_get_singleton = gdnative_global_get_singleton;
 	gdni.object_get_instance_binding = gdnative_object_get_instance_binding;
+	gdni.object_set_instance_binding = gdnative_object_set_instance_binding;
 
 	gdni.object_cast_to = gdnative_object_cast_to;
 	gdni.object_get_instance_from_id = gdnative_object_get_instance_from_id;

core/extension/gdnative_interface.h

@@ -39,6 +39,11 @@
 #include <stdint.h>
 #include <stdio.h>
 
+#ifndef __cplusplus
+typedef uint32_t char32_t;
+typedef uint16_t char16_t;
+#endif
+
 #ifdef __cplusplus
 extern "C" {
 #endif
@@ -160,6 +165,7 @@ typedef void (*GDNativeTypeFromVariantConstructorFunc)(GDNativeTypePtr, GDNative
 typedef void (*GDNativePtrOperatorEvaluator)(const GDNativeTypePtr p_left, const GDNativeTypePtr p_right, GDNativeTypePtr r_result);
 typedef void (*GDNativePtrBuiltInMethod)(GDNativeTypePtr p_base, const GDNativeTypePtr *p_args, GDNativeTypePtr r_return, int p_argument_count);
 typedef void (*GDNativePtrConstructor)(GDNativeTypePtr p_base, const GDNativeTypePtr *p_args);
+typedef void (*GDNativePtrDestructor)(GDNativeTypePtr p_base);
 typedef void (*GDNativePtrSetter)(GDNativeTypePtr p_base, const GDNativeTypePtr p_value);
 typedef void (*GDNativePtrGetter)(const GDNativeTypePtr p_base, GDNativeTypePtr r_value);
 typedef void (*GDNativePtrIndexedSetter)(GDNativeTypePtr p_base, GDNativeInt p_index, const GDNativeTypePtr p_value);
@@ -173,7 +179,7 @@ typedef GDNativeObjectPtr (*GDNativeClassConstructor)();
 
 typedef void *(*GDNativeInstanceBindingCreateCallback)(void *p_token, void *p_instance);
 typedef void (*GDNativeInstanceBindingFreeCallback)(void *p_token, void *p_instance, void *p_binding);
-typedef GDNativeBool (*GDNativeInstanceBindingReferenceCallback)(void *p_token, void *p_instance, GDNativeBool p_reference);
+typedef GDNativeBool (*GDNativeInstanceBindingReferenceCallback)(void *p_token, void *p_binding, GDNativeBool p_reference);
 
 struct GDNativeInstanceBindingCallbacks {
 	GDNativeInstanceBindingCreateCallback create_callback;
@@ -206,6 +212,7 @@ typedef void (*GDNativeExtensionClassUnreference)(GDExtensionClassInstancePtr p_
 typedef void (*GDNativeExtensionClassCallVirtual)(GDExtensionClassInstancePtr p_instance, const GDNativeTypePtr *p_args, GDNativeTypePtr r_ret);
 typedef GDExtensionClassInstancePtr (*GDNativeExtensionClassCreateInstance)(void *p_userdata);
 typedef void (*GDNativeExtensionClassFreeInstance)(void *p_userdata, GDExtensionClassInstancePtr p_instance);
+typedef void (*GDNativeExtensionClassObjectInstance)(GDExtensionClassInstancePtr p_instance, GDNativeObjectPtr p_object_instance);
 typedef GDNativeExtensionClassCallVirtual (*GDNativeExtensionClassGetVirtual)(void *p_userdata, const char *p_name);
 
 typedef struct {
@@ -219,7 +226,8 @@ typedef struct {
 	GDNativeExtensionClassUnreference unreference_func;
 	GDNativeExtensionClassCreateInstance create_instance_func; /* this one is mandatory */
 	GDNativeExtensionClassFreeInstance free_instance_func; /* this one is mandatory */
-	GDNativeExtensionClassGetVirtual get_firtual_func;
+	GDNativeExtensionClassObjectInstance object_instance_func; /* this one is mandatory */
+	GDNativeExtensionClassGetVirtual get_virtual_func;
 	void *class_userdata;
 } GDNativeExtensionClassCreationInfo;
 
@@ -256,8 +264,8 @@ typedef enum {
 	GDNATIVE_EXTENSION_METHOD_ARGUMENT_METADATA_REAL_IS_DOUBLE
 } GDNativeExtensionClassMethodArgumentMetadata;
 
-typedef void (*GDNativeExtensionClassMethodCall)(GDExtensionClassInstancePtr p_instance, const GDNativeVariantPtr *p_args, const GDNativeInt p_argument_count, GDNativeVariantPtr r_return, GDNativeCallError *r_error);
-typedef void (*GDNativeExtensionClassMethodPtrCall)(GDExtensionClassInstancePtr p_instance, const GDNativeTypePtr *p_args, GDNativeTypePtr r_ret);
+typedef void (*GDNativeExtensionClassMethodCall)(void *method_userdata, GDExtensionClassInstancePtr p_instance, const GDNativeVariantPtr *p_args, const GDNativeInt p_argument_count, GDNativeVariantPtr r_return, GDNativeCallError *r_error);
+typedef void (*GDNativeExtensionClassMethodPtrCall)(void *method_userdata, GDExtensionClassInstancePtr p_instance, const GDNativeTypePtr *p_args, GDNativeTypePtr r_ret);
 
 /* passing -1 as argument in the following functions refers to the return type */
 typedef GDNativeVariantType (*GDNativeExtensionClassMethodGetArgumentType)(void *p_method_userdata, int32_t p_argument);
@@ -339,6 +347,7 @@ typedef struct {
 	GDNativePtrOperatorEvaluator (*variant_get_ptr_operator_evaluator)(GDNativeVariantOperator p_operator, GDNativeVariantType p_type_a, GDNativeVariantType p_type_b);
 	GDNativePtrBuiltInMethod (*variant_get_ptr_builtin_method)(GDNativeVariantType p_type, const char *p_method, GDNativeInt p_hash);
 	GDNativePtrConstructor (*variant_get_ptr_constructor)(GDNativeVariantType p_type, int32_t p_constructor);
+	GDNativePtrDestructor (*variant_get_ptr_destructor)(GDNativeVariantType p_type);
 	void (*variant_construct)(GDNativeVariantType p_type, GDNativeVariantPtr p_base, const GDNativeVariantPtr *p_args, int32_t p_argument_count, GDNativeCallError *r_error);
 	GDNativePtrSetter (*variant_get_ptr_setter)(GDNativeVariantType p_type, const char *p_member);
 	GDNativePtrGetter (*variant_get_ptr_getter)(GDNativeVariantType p_type, const char *p_member);
@@ -383,7 +392,8 @@ typedef struct {
 	void (*object_method_bind_ptrcall)(GDNativeMethodBindPtr p_method_bind, GDNativeObjectPtr p_instance, const GDNativeTypePtr *p_args, GDNativeTypePtr r_ret);
 	void (*object_destroy)(GDNativeObjectPtr p_o);
 	GDNativeObjectPtr (*global_get_singleton)(const char *p_name);
-	void *(*object_get_instance_binding)(GDNativeObjectPtr p_o, void *p_token, GDNativeInstanceBindingCallbacks *p_callbacks);
+	void *(*object_get_instance_binding)(GDNativeObjectPtr p_o, void *p_token, const GDNativeInstanceBindingCallbacks *p_callbacks);
+	void (*object_set_instance_binding)(GDNativeObjectPtr p_o, void *p_token, void *p_binding, const GDNativeInstanceBindingCallbacks *p_callbacks);
 
 	GDNativeObjectPtr (*object_cast_to)(const GDNativeObjectPtr p_object, void *p_class_tag);
 	GDNativeObjectPtr (*object_get_instance_from_id)(GDObjectInstanceID p_instance_id);

core/extension/native_extension.cpp

@@ -29,6 +29,7 @@
 /*************************************************************************/
 
 #include "native_extension.h"
+#include "core/config/project_settings.h"
 #include "core/io/config_file.h"
 #include "core/object/class_db.h"
 #include "core/object/method_bind.h"
@@ -69,7 +70,7 @@ public:
 		Variant ret;
 		GDExtensionClassInstancePtr extension_instance = p_object->_get_extension_instance();
 		GDNativeCallError ce;
-		call_func(extension_instance, (const GDNativeVariantPtr *)p_args, p_arg_count, (GDNativeVariantPtr)&ret, &ce);
+		call_func(method_userdata, extension_instance, (const GDNativeVariantPtr *)p_args, p_arg_count, (GDNativeVariantPtr)&ret, &ce);
 		r_error.error = Callable::CallError::Error(ce.error);
 		r_error.argument = ce.argument;
 		r_error.expected = ce.expected;
@@ -78,7 +79,7 @@ public:
 	virtual void ptrcall(Object *p_object, const void **p_args, void *r_ret) {
 		ERR_FAIL_COND_MSG(vararg, "Vararg methods don't have ptrcall support. This is most likely an engine bug.");
 		GDExtensionClassInstancePtr extension_instance = p_object->_get_extension_instance();
-		ptrcall_func(extension_instance, (const GDNativeTypePtr *)p_args, (GDNativeTypePtr)r_ret);
+		ptrcall_func(method_userdata, extension_instance, (const GDNativeTypePtr *)p_args, (GDNativeTypePtr)r_ret);
 	}
 
 	virtual bool is_vararg() const {
@@ -91,6 +92,7 @@ public:
 		get_argument_type_func = p_method_info->get_argument_type_func;
 		get_argument_info_func = p_method_info->get_argument_info_func;
 		get_argument_metadata_func = p_method_info->get_argument_metadata_func;
+		set_name(p_method_info->name);
 
 		vararg = p_method_info->method_flags & GDNATIVE_EXTENSION_METHOD_FLAG_VARARG;
 
@@ -109,7 +111,7 @@ void NativeExtension::_register_extension_class(const GDNativeExtensionClassLibr
 	NativeExtension *self = (NativeExtension *)p_library;
 
 	StringName class_name = p_class_name;
-	ERR_FAIL_COND_MSG(String(class_name).is_valid_identifier(), "Attempt to register extension clas '" + class_name + "', which is not a valid class identifier.");
+	ERR_FAIL_COND_MSG(!String(class_name).is_valid_identifier(), "Attempt to register extension class '" + class_name + "', which is not a valid class identifier.");
 	ERR_FAIL_COND_MSG(ClassDB::class_exists(class_name), "Attempt to register extension class '" + class_name + "', which appears to be already registered.");
 
 	Extension *parent_extension = nullptr;
@@ -150,6 +152,7 @@ void NativeExtension::_register_extension_class(const GDNativeExtensionClassLibr
 	extension->native_extension.unreference = p_extension_funcs->unreference_func;
 	extension->native_extension.class_userdata = p_extension_funcs->class_userdata;
 	extension->native_extension.create_instance = p_extension_funcs->create_instance_func;
+	extension->native_extension.set_object_instance = p_extension_funcs->object_instance_func;
 	extension->native_extension.free_instance = p_extension_funcs->free_instance_func;
 
 	ClassDB::register_extension_class(&extension->native_extension);
@@ -159,11 +162,12 @@ void NativeExtension::_register_extension_class_method(const GDNativeExtensionCl
 
 	StringName class_name = p_class_name;
 	StringName method_name = p_method_info->name;
-	ERR_FAIL_COND_MSG(self->extension_classes.has(class_name), "Attempt to register extension method '" + String(method_name) + "' for unexisting class '" + class_name + "'.");
+	ERR_FAIL_COND_MSG(!self->extension_classes.has(class_name), "Attempt to register extension method '" + String(method_name) + "' for unexisting class '" + class_name + "'.");
 
 	//Extension *extension = &self->extension_classes[class_name];
 
 	NativeExtensionMethodBind *method = memnew(NativeExtensionMethodBind(p_method_info));
+	method->set_instance_class(class_name);
 
 	ClassDB::bind_method_custom(class_name, method);
 }
@@ -171,7 +175,7 @@ void NativeExtension::_register_extension_class_integer_constant(const GDNativeE
 	NativeExtension *self = (NativeExtension *)p_library;
 
 	StringName class_name = p_class_name;
-	ERR_FAIL_COND_MSG(self->extension_classes.has(class_name), "Attempt to register extension constant '" + String(p_constant_name) + "' for unexisting class '" + class_name + "'.");
+	ERR_FAIL_COND_MSG(!self->extension_classes.has(class_name), "Attempt to register extension constant '" + String(p_constant_name) + "' for unexisting class '" + class_name + "'.");
 
 	//Extension *extension = &self->extension_classes[class_name];
 
@@ -181,7 +185,7 @@ void NativeExtension::_register_extension_class_property(const GDNativeExtension
 	NativeExtension *self = (NativeExtension *)p_library;
 
 	StringName class_name = p_class_name;
-	ERR_FAIL_COND_MSG(self->extension_classes.has(class_name), "Attempt to register extension class property '" + String(p_info->name) + "' for unexisting class '" + class_name + "'.");
+	ERR_FAIL_COND_MSG(!self->extension_classes.has(class_name), "Attempt to register extension class property '" + String(p_info->name) + "' for unexisting class '" + class_name + "'.");
 
 	//Extension *extension = &self->extension_classes[class_name];
 	PropertyInfo pinfo;
@@ -199,7 +203,7 @@ void NativeExtension::_register_extension_class_signal(const GDNativeExtensionCl
 	NativeExtension *self = (NativeExtension *)p_library;
 
 	StringName class_name = p_class_name;
-	ERR_FAIL_COND_MSG(self->extension_classes.has(class_name), "Attempt to register extension class signal '" + String(p_signal_name) + "' for unexisting class '" + class_name + "'.");
+	ERR_FAIL_COND_MSG(!self->extension_classes.has(class_name), "Attempt to register extension class signal '" + String(p_signal_name) + "' for unexisting class '" + class_name + "'.");
 
 	MethodInfo s;
 	s.name = p_signal_name;
@@ -220,7 +224,7 @@ void NativeExtension::_unregister_extension_class(const GDNativeExtensionClassLi
 	NativeExtension *self = (NativeExtension *)p_library;
 
 	StringName class_name = p_class_name;
-	ERR_FAIL_COND_MSG(self->extension_classes.has(class_name), "Attempt to unregister unexisting extension class '" + class_name + "'.");
+	ERR_FAIL_COND_MSG(!self->extension_classes.has(class_name), "Attempt to unregister unexisting extension class '" + class_name + "'.");
 	Extension *ext = &self->extension_classes[class_name];
 	ERR_FAIL_COND_MSG(ext->native_extension.children.size(), "Attempt to unregister class '" + class_name + "' while other extension classes inherit from it.");
 
@@ -368,7 +372,7 @@ RES NativeExtensionResourceLoader::load(const String &p_path, const String &p_or
 		}
 	}
 
-	if (library_path != String()) {
+	if (library_path == String()) {
 		if (r_error) {
 			*r_error = ERR_FILE_NOT_FOUND;
 		}
@@ -381,7 +385,8 @@ RES NativeExtensionResourceLoader::load(const String &p_path, const String &p_or
 
 	Ref<NativeExtension> lib;
 	lib.instantiate();
-	err = lib->open_library(library_path, entry_symbol);
+	String abs_path = ProjectSettings::get_singleton()->globalize_path(library_path);
+	err = lib->open_library(abs_path, entry_symbol);
 
 	if (r_error) {
 		*r_error = err;

core/extension/native_extension.h

@@ -35,8 +35,8 @@
 #include "core/io/resource_loader.h"
 #include "core/object/ref_counted.h"
 
-class NativeExtension : public RefCounted {
-	GDCLASS(NativeExtension, RefCounted)
+class NativeExtension : public Resource {
+	GDCLASS(NativeExtension, Resource)
 
 	void *library = nullptr; // pointer if valid,
 

core/register_core_types.cpp

@@ -82,6 +82,7 @@ static Ref<ResourceFormatLoaderImage> resource_format_image;
 static Ref<TranslationLoaderPO> resource_format_po;
 static Ref<ResourceFormatSaverCrypto> resource_format_saver_crypto;
 static Ref<ResourceFormatLoaderCrypto> resource_format_loader_crypto;
+static Ref<NativeExtensionResourceLoader> resource_loader_native_extension;
 
 static _ResourceLoader *_resource_loader = nullptr;
 static _ResourceSaver *_resource_saver = nullptr;
@@ -234,6 +235,9 @@ void register_core_types() {
 
 	native_extension_manager = memnew(NativeExtensionManager);
 
+	resource_loader_native_extension.instantiate();
+	ResourceLoader::add_resource_format_loader(resource_loader_native_extension);
+
 	ip = IP::create();
 
 	_geometry_2d = memnew(_Geometry2D);
@@ -298,6 +302,7 @@ void register_core_singletons() {
 
 void register_core_extensions() {
 	// Hardcoded for now.
+	NativeExtension::initialize_native_extensions();
 	if (ProjectSettings::get_singleton()->has_setting("native_extensions/paths")) {
 		Vector<String> paths = ProjectSettings::get_singleton()->get("native_extensions/paths");
 		for (int i = 0; i < paths.size(); i++) {
@@ -349,6 +354,9 @@ void unregister_core_types() {
 		memdelete(ip);
 	}
 
+	ResourceLoader::remove_resource_format_loader(resource_loader_native_extension);
+	resource_loader_native_extension.unref();
+
 	ResourceLoader::finalize();
 
 	ClassDB::cleanup_defaults();

core/variant/variant.cpp

@@ -3533,12 +3533,13 @@ void Variant::register_types() {
 	_register_variant_methods();
 	_register_variant_setters_getters();
 	_register_variant_constructors();
+	_register_variant_destructors();
 	_register_variant_utility_functions();
 }
 void Variant::unregister_types() {
 	_unregister_variant_operators();
 	_unregister_variant_methods();
 	_unregister_variant_setters_getters();
-	_unregister_variant_constructors();
+	_unregister_variant_destructors();
 	_unregister_variant_utility_functions();
 }

core/variant/variant.h

@@ -208,7 +208,7 @@ private:
 		Transform3D *_transform3d;
 		PackedArrayRefBase *packed_array;
 		void *_ptr; //generic pointer
-		uint8_t _mem[sizeof(ObjData) > (sizeof(real_t) * 4) ? sizeof(ObjData) : (sizeof(real_t) * 4)];
+		uint8_t _mem[sizeof(ObjData) > (sizeof(real_t) * 4) ? sizeof(ObjData) : (sizeof(real_t) * 4)]{ 0 };
 	} _data alignas(8);
 
 	void reference(const Variant &p_variant);
@@ -271,6 +271,8 @@ private:
 	static void _register_variant_setters_getters();
 	static void _unregister_variant_setters_getters();
 	static void _register_variant_constructors();
+	static void _unregister_variant_destructors();
+	static void _register_variant_destructors();
 	static void _unregister_variant_constructors();
 	static void _register_variant_utility_functions();
 	static void _unregister_variant_utility_functions();
@@ -534,6 +536,14 @@ public:
 
 	static void get_constructor_list(Type p_type, List<MethodInfo> *r_list); //convenience
 
+	/* Destructors */
+
+	// Only ptrcall is available.
+	typedef void (*PTRDestructor)(void *base);
+
+	static PTRDestructor get_ptr_destructor(Variant::Type p_type);
+	static bool has_destructor(Variant::Type p_type);
+
 	/* Properties */
 
 	void set_named(const StringName &p_member, const Variant &p_value, bool &r_valid);

core/variant/variant_destruct.cpp

@@ -0,0 +1,78 @@
+/*************************************************************************/
+/*  variant_destruct.cpp                                                 */
+/*************************************************************************/
+/*                       This file is part of:                           */
+/*                           GODOT ENGINE                                */
+/*                      https://godotengine.org                          */
+/*************************************************************************/
+/* Copyright (c) 2007-2021 Juan Linietsky, Ariel Manzur.                 */
+/* Copyright (c) 2014-2021 Godot Engine contributors (cf. AUTHORS.md).   */
+/*                                                                       */
+/* Permission is hereby granted, free of charge, to any person obtaining */
+/* a copy of this software and associated documentation files (the       */
+/* "Software"), to deal in the Software without restriction, including   */
+/* without limitation the rights to use, copy, modify, merge, publish,   */
+/* distribute, sublicense, and/or sell copies of the Software, and to    */
+/* permit persons to whom the Software is furnished to do so, subject to */
+/* the following conditions:                                             */
+/*                                                                       */
+/* The above copyright notice and this permission notice shall be        */
+/* included in all copies or substantial portions of the Software.       */
+/*                                                                       */
+/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
+/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF    */
+/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
+/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY  */
+/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,  */
+/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE     */
+/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
+/*************************************************************************/
+
+#include "variant_destruct.h"
+
+#include "core/templates/local_vector.h"
+
+static Variant::PTRDestructor destruct_pointers[Variant::VARIANT_MAX] = { nullptr };
+
+template <class T>
+static void add_destructor() {
+	destruct_pointers[T::get_base_type()] = T::ptr_destruct;
+}
+
+void Variant::_register_variant_destructors() {
+	add_destructor<VariantDestruct<String>>();
+	add_destructor<VariantDestruct<Transform2D>>();
+	add_destructor<VariantDestruct<::AABB>>();
+	add_destructor<VariantDestruct<Basis>>();
+	add_destructor<VariantDestruct<Transform3D>>();
+	add_destructor<VariantDestruct<StringName>>();
+	add_destructor<VariantDestruct<NodePath>>();
+	add_destructor<VariantDestruct<::RID>>();
+	add_destructor<VariantDestruct<Callable>>();
+	add_destructor<VariantDestruct<Signal>>();
+	add_destructor<VariantDestruct<Dictionary>>();
+	add_destructor<VariantDestruct<Array>>();
+	add_destructor<VariantDestruct<PackedByteArray>>();
+	add_destructor<VariantDestruct<PackedInt32Array>>();
+	add_destructor<VariantDestruct<PackedInt64Array>>();
+	add_destructor<VariantDestruct<PackedFloat32Array>>();
+	add_destructor<VariantDestruct<PackedFloat64Array>>();
+	add_destructor<VariantDestruct<PackedStringArray>>();
+	add_destructor<VariantDestruct<PackedVector2Array>>();
+	add_destructor<VariantDestruct<PackedVector3Array>>();
+	add_destructor<VariantDestruct<PackedColorArray>>();
+}
+
+void Variant::_unregister_variant_destructors() {
+	// Nothing to be done.
+}
+
+Variant::PTRDestructor Variant::get_ptr_destructor(Variant::Type p_type) {
+	ERR_FAIL_INDEX_V(p_type, Variant::VARIANT_MAX, nullptr);
+	return destruct_pointers[p_type];
+}
+
+bool Variant::has_destructor(Variant::Type p_type) {
+	ERR_FAIL_INDEX_V(p_type, Variant::VARIANT_MAX, false);
+	return destruct_pointers[p_type] != nullptr;
+}

core/variant/variant_destruct.h

@@ -0,0 +1,76 @@
+/*************************************************************************/
+/*  variant_destruct.h                                                   */
+/*************************************************************************/
+/*                       This file is part of:                           */
+/*                           GODOT ENGINE                                */
+/*                      https://godotengine.org                          */
+/*************************************************************************/
+/* Copyright (c) 2007-2021 Juan Linietsky, Ariel Manzur.                 */
+/* Copyright (c) 2014-2021 Godot Engine contributors (cf. AUTHORS.md).   */
+/*                                                                       */
+/* Permission is hereby granted, free of charge, to any person obtaining */
+/* a copy of this software and associated documentation files (the       */
+/* "Software"), to deal in the Software without restriction, including   */
+/* without limitation the rights to use, copy, modify, merge, publish,   */
+/* distribute, sublicense, and/or sell copies of the Software, and to    */
+/* permit persons to whom the Software is furnished to do so, subject to */
+/* the following conditions:                                             */
+/*                                                                       */
+/* The above copyright notice and this permission notice shall be        */
+/* included in all copies or substantial portions of the Software.       */
+/*                                                                       */
+/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
+/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF    */
+/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
+/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY  */
+/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,  */
+/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE     */
+/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
+/*************************************************************************/
+
+#ifndef VARIANT_DESTRUCT_H
+#define VARIANT_DESTRUCT_H
+
+#include "core/variant/variant.h"
+
+#include "core/object/class_db.h"
+
+template <class T>
+struct VariantDestruct {};
+
+#define MAKE_PTRDESTRUCT(m_type)                               \
+	template <>                                                \
+	struct VariantDestruct<m_type> {                           \
+		_FORCE_INLINE_ static void ptr_destruct(void *p_ptr) { \
+			reinterpret_cast<m_type *>(p_ptr)->~m_type();      \
+		}                                                      \
+		_FORCE_INLINE_ static Variant::Type get_base_type() {  \
+			return GetTypeInfo<m_type>::VARIANT_TYPE;          \
+		}                                                      \
+	}
+
+MAKE_PTRDESTRUCT(String);
+MAKE_PTRDESTRUCT(Transform2D);
+MAKE_PTRDESTRUCT(AABB);
+MAKE_PTRDESTRUCT(Basis);
+MAKE_PTRDESTRUCT(Transform3D);
+MAKE_PTRDESTRUCT(StringName);
+MAKE_PTRDESTRUCT(NodePath);
+MAKE_PTRDESTRUCT(RID);
+MAKE_PTRDESTRUCT(Callable);
+MAKE_PTRDESTRUCT(Signal);
+MAKE_PTRDESTRUCT(Dictionary);
+MAKE_PTRDESTRUCT(Array);
+MAKE_PTRDESTRUCT(PackedByteArray);
+MAKE_PTRDESTRUCT(PackedInt32Array);
+MAKE_PTRDESTRUCT(PackedInt64Array);
+MAKE_PTRDESTRUCT(PackedFloat32Array);
+MAKE_PTRDESTRUCT(PackedFloat64Array);
+MAKE_PTRDESTRUCT(PackedStringArray);
+MAKE_PTRDESTRUCT(PackedVector2Array);
+MAKE_PTRDESTRUCT(PackedVector3Array);
+MAKE_PTRDESTRUCT(PackedColorArray);
+
+#undef MAKE_PTRDESTRUCT
+
+#endif // VARIANT_DESTRUCT_H

core/variant/variant_internal.h

@@ -1171,6 +1171,11 @@ struct VariantInitializer<PackedColorArray> {
 	static _FORCE_INLINE_ void init(Variant *v) { VariantInternal::init_color_array(v); }
 };
 
+template <>
+struct VariantInitializer<Object *> {
+	static _FORCE_INLINE_ void init(Variant *v) { VariantInternal::object_assign_null(v); }
+};
+
 template <class T>
 struct VariantZeroAssigner {
 };
@@ -1385,4 +1390,19 @@ struct VariantTypeAdjust<Object *> {
 	}
 };
 
+// GDNative extension helpers.
+
+template <class T>
+struct VariantTypeConstructor {
+	_FORCE_INLINE_ static void variant_from_type(void *p_variant, void *p_value) {
+		Variant *variant = reinterpret_cast<Variant *>(p_variant);
+		VariantInitializer<T>::init(variant);
+		VariantInternalAccessor<T>::set(variant, *((T *)p_value));
+	}
+
+	_FORCE_INLINE_ static void type_from_variant(void *p_value, void *p_variant) {
+		*((T *)p_value) = VariantInternalAccessor<T>::get(reinterpret_cast<Variant *>(p_variant));
+	}
+};
+
 #endif // VARIANT_INTERNAL_H

doc/classes/NativeExtension.xml

@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="UTF-8" ?>
-<class name="NativeExtension" inherits="RefCounted" version="4.0">
+<class name="NativeExtension" inherits="Resource" version="4.0">
 	<brief_description>
 	</brief_description>
 	<description>