Allow registering "runtime classes" in modules (not just GDExtension)

4 files changed, 111 insertions, 19 deletions

diff --git a/core/object/class_db.cpp b/core/object/class_db.cpp
index 7671b7972e..63adc5b502 100644
--- a/core/object/class_db.cpp
+++ b/core/object/class_db.cpp
@@ -178,6 +178,7 @@ public:
 		while (native_parent->gdextension) {
 			native_parent = native_parent->inherits_ptr;
 		}
+		ERR_FAIL_NULL_V(native_parent->creation_func, nullptr);
 
 		// Construct a placeholder.
 		Object *obj = native_parent->creation_func();
@@ -501,7 +502,7 @@ Object *ClassDB::_instantiate_internal(const StringName &p_class, bool p_require
 	if (ti->gdextension && ti->gdextension->create_instance) {
 		ObjectGDExtension *extension = ti->gdextension;
 #ifdef TOOLS_ENABLED
-		if (!p_require_real_class && ti->gdextension->is_runtime && Engine::get_singleton()->is_editor_hint()) {
+		if (!p_require_real_class && ti->is_runtime && Engine::get_singleton()->is_editor_hint()) {
 			extension = get_placeholder_extension(ti->name);
 		}
 #endif
@@ -514,6 +515,17 @@ Object *ClassDB::_instantiate_internal(const StringName &p_class, bool p_require
 #endif
 		return obj;
 	} else {
+#ifdef TOOLS_ENABLED
+		if (!p_require_real_class && ti->is_runtime && Engine::get_singleton()->is_editor_hint()) {
+			if (!ti->inherits_ptr || !ti->inherits_ptr->creation_func) {
+				ERR_PRINT_ONCE(vformat("Cannot make a placeholder instance of runtime class %s because its parent cannot be constructed.", ti->name));
+			} else {
+				ObjectGDExtension *extension = get_placeholder_extension(ti->name);
+				return (Object *)extension->create_instance(extension->class_userdata);
+			}
+		}
+#endif
+
 		return ti->creation_func();
 	}
 }
@@ -544,26 +556,42 @@ ObjectGDExtension *ClassDB::get_placeholder_extension(const StringName &p_class)
 		}
 		ERR_FAIL_NULL_V_MSG(ti, nullptr, "Cannot get class '" + String(p_class) + "'.");
 		ERR_FAIL_COND_V_MSG(ti->disabled, nullptr, "Class '" + String(p_class) + "' is disabled.");
-		ERR_FAIL_NULL_V_MSG(ti->gdextension, nullptr, "Class '" + String(p_class) + "' has no native extension.");
 	}
 
+	// Make a "fake" extension to act as a placeholder.
 	placeholder_extensions[p_class] = ObjectGDExtension();
 	placeholder_extension = placeholder_extensions.getptr(p_class);
 
-	// Make a "fake" extension to act as a placeholder.
-	placeholder_extension->library = ti->gdextension->library;
-	placeholder_extension->parent = ti->gdextension->parent;
-	placeholder_extension->children = ti->gdextension->children;
-	placeholder_extension->parent_class_name = ti->gdextension->parent_class_name;
-	placeholder_extension->class_name = ti->gdextension->class_name;
-	placeholder_extension->editor_class = ti->gdextension->editor_class;
-	placeholder_extension->reloadable = ti->gdextension->reloadable;
-	placeholder_extension->is_virtual = ti->gdextension->is_virtual;
-	placeholder_extension->is_abstract = ti->gdextension->is_abstract;
-	placeholder_extension->is_exposed = ti->gdextension->is_exposed;
 	placeholder_extension->is_runtime = true;
 	placeholder_extension->is_placeholder = true;
 
+	if (ti->gdextension) {
+		placeholder_extension->library = ti->gdextension->library;
+		placeholder_extension->parent = ti->gdextension->parent;
+		placeholder_extension->children = ti->gdextension->children;
+		placeholder_extension->parent_class_name = ti->gdextension->parent_class_name;
+		placeholder_extension->class_name = ti->gdextension->class_name;
+		placeholder_extension->editor_class = ti->gdextension->editor_class;
+		placeholder_extension->reloadable = ti->gdextension->reloadable;
+		placeholder_extension->is_virtual = ti->gdextension->is_virtual;
+		placeholder_extension->is_abstract = ti->gdextension->is_abstract;
+		placeholder_extension->is_exposed = ti->gdextension->is_exposed;
+
+		placeholder_extension->tracking_userdata = ti->gdextension->tracking_userdata;
+		placeholder_extension->track_instance = ti->gdextension->track_instance;
+		placeholder_extension->untrack_instance = ti->gdextension->untrack_instance;
+	} else {
+		placeholder_extension->library = nullptr;
+		placeholder_extension->parent = nullptr;
+		placeholder_extension->parent_class_name = ti->inherits;
+		placeholder_extension->class_name = ti->name;
+		placeholder_extension->editor_class = ti->api == API_EDITOR;
+		placeholder_extension->reloadable = false;
+		placeholder_extension->is_virtual = ti->is_virtual;
+		placeholder_extension->is_abstract = false;
+		placeholder_extension->is_exposed = ti->exposed;
+	}
+
 	placeholder_extension->set = &PlaceholderExtensionInstance::placeholder_instance_set;
 	placeholder_extension->get = &PlaceholderExtensionInstance::placeholder_instance_get;
 	placeholder_extension->get_property_list = &PlaceholderExtensionInstance::placeholder_instance_get_property_list;
@@ -586,10 +614,6 @@ ObjectGDExtension *ClassDB::get_placeholder_extension(const StringName &p_class)
 	placeholder_extension->call_virtual_with_data = nullptr;
 	placeholder_extension->recreate_instance = &PlaceholderExtensionInstance::placeholder_class_recreate_instance;
 
-	placeholder_extension->tracking_userdata = ti->gdextension->tracking_userdata;
-	placeholder_extension->track_instance = ti->gdextension->track_instance;
-	placeholder_extension->untrack_instance = ti->gdextension->untrack_instance;
-
 	return placeholder_extension;
 }
 #endif
@@ -2028,6 +2052,9 @@ void ClassDB::register_extension_class(ObjectGDExtension *p_extension) {
 		}
 	}
 	c.reloadable = p_extension->reloadable;
+#ifdef TOOLS_ENABLED
+	c.is_runtime = p_extension->is_runtime;
+#endif
 
 	classes[p_extension->class_name] = c;
 }
diff --git a/core/object/class_db.h b/core/object/class_db.h
index 5b4f218845..7f117b4a9b 100644
--- a/core/object/class_db.h
+++ b/core/object/class_db.h
@@ -133,6 +133,7 @@ public:
 		bool exposed = false;
 		bool reloadable = false;
 		bool is_virtual = false;
+		bool is_runtime = false;
 		Object *(*creation_func)() = nullptr;
 
 		ClassInfo() {}
@@ -234,6 +235,23 @@ public:
 		T::register_custom_data_to_otdb();
 	}
 
+	template <class T>
+	static void register_runtime_class() {
+		GLOBAL_LOCK_FUNCTION;
+		static_assert(types_are_same_v<typename T::self_type, T>, "Class not declared properly, please use GDCLASS.");
+		T::initialize_class();
+		ClassInfo *t = classes.getptr(T::get_class_static());
+		ERR_FAIL_NULL(t);
+		ERR_FAIL_COND_MSG(t->inherits_ptr && !t->inherits_ptr->creation_func, vformat("Cannot register runtime class '%s' that descends from an abstract parent class.", T::get_class_static()));
+		t->creation_func = &creator<T>;
+		t->exposed = true;
+		t->is_virtual = false;
+		t->is_runtime = true;
+		t->class_ptr = T::get_class_ptr_static();
+		t->api = current_api;
+		T::register_custom_data_to_otdb();
+	}
+
 	static void register_extension_class(ObjectGDExtension *p_extension);
 	static void unregister_extension_class(const StringName &p_class, bool p_free_method_binds = true);
 
@@ -518,6 +536,11 @@ _FORCE_INLINE_ Vector<Error> errarray(P... p_args) {
 		::ClassDB::register_internal_class<m_class>(); \
 	}
 
+#define GDREGISTER_RUNTIME_CLASS(m_class)             \
+	if (m_class::_class_is_enabled) {                 \
+		::ClassDB::register_runtime_class<m_class>(); \
+	}
+
 #define GDREGISTER_NATIVE_STRUCT(m_class, m_code) ClassDB::register_native_struct(#m_class, m_code, sizeof(m_class))
 
 #include "core/disabled_classes.gen.h"
diff --git a/core/object/method_bind.h b/core/object/method_bind.h
index d67fd003c8..a1723adb9a 100644
--- a/core/object/method_bind.h
+++ b/core/object/method_bind.h
@@ -225,6 +225,9 @@ class MethodBindVarArgT : public MethodBindVarArgBase<MethodBindVarArgT<T>, T, v
 
 public:
 	virtual Variant call(Object *p_object, const Variant **p_args, int p_arg_count, Callable::CallError &r_error) const override {
+#ifdef TOOLS_ENABLED
+		ERR_FAIL_COND_V_MSG(p_object && p_object->is_extension_placeholder(), Variant(), vformat("Cannot call method bind '%s' on placeholder instance.", MethodBind::get_name()));
+#endif
 		(static_cast<T *>(p_object)->*MethodBindVarArgBase<MethodBindVarArgT<T>, T, void, false>::method)(p_args, p_arg_count, r_error);
 		return {};
 	}
@@ -261,6 +264,9 @@ public:
 #pragma GCC diagnostic ignored "-Wmaybe-uninitialized"
 #endif
 	virtual Variant call(Object *p_object, const Variant **p_args, int p_arg_count, Callable::CallError &r_error) const override {
+#ifdef TOOLS_ENABLED
+		ERR_FAIL_COND_V_MSG(p_object && p_object->is_extension_placeholder(), Variant(), vformat("Cannot call method bind '%s' on placeholder instance.", MethodBind::get_name()));
+#endif
 		return (static_cast<T *>(p_object)->*MethodBindVarArgBase<MethodBindVarArgTR<T, R>, T, R, true>::method)(p_args, p_arg_count, r_error);
 	}
 
@@ -329,6 +335,9 @@ public:
 
 #endif
 	virtual Variant call(Object *p_object, const Variant **p_args, int p_arg_count, Callable::CallError &r_error) const override {
+#ifdef TOOLS_ENABLED
+		ERR_FAIL_COND_V_MSG(p_object && p_object->is_extension_placeholder(), Variant(), vformat("Cannot call method bind '%s' on placeholder instance.", MethodBind::get_name()));
+#endif
 #ifdef TYPED_METHOD_BIND
 		call_with_variant_args_dv(static_cast<T *>(p_object), method, p_args, p_arg_count, r_error, get_default_arguments());
 #else
@@ -338,6 +347,9 @@ public:
 	}
 
 	virtual void validated_call(Object *p_object, const Variant **p_args, Variant *r_ret) const override {
+#ifdef TOOLS_ENABLED
+		ERR_FAIL_COND_MSG(p_object && p_object->is_extension_placeholder(), vformat("Cannot call method bind '%s' on placeholder instance.", MethodBind::get_name()));
+#endif
 #ifdef TYPED_METHOD_BIND
 		call_with_validated_object_instance_args(static_cast<T *>(p_object), method, p_args);
 #else
@@ -346,6 +358,9 @@ public:
 	}
 
 	virtual void ptrcall(Object *p_object, const void **p_args, void *r_ret) const override {
+#ifdef TOOLS_ENABLED
+		ERR_FAIL_COND_MSG(p_object && p_object->is_extension_placeholder(), vformat("Cannot call method bind '%s' on placeholder instance.", MethodBind::get_name()));
+#endif
 #ifdef TYPED_METHOD_BIND
 		call_with_ptr_args<T, P...>(static_cast<T *>(p_object), method, p_args);
 #else
@@ -404,6 +419,9 @@ public:
 
 #endif
 	virtual Variant call(Object *p_object, const Variant **p_args, int p_arg_count, Callable::CallError &r_error) const override {
+#ifdef TOOLS_ENABLED
+		ERR_FAIL_COND_V_MSG(p_object && p_object->is_extension_placeholder(), Variant(), vformat("Cannot call method bind '%s' on placeholder instance.", MethodBind::get_name()));
+#endif
 #ifdef TYPED_METHOD_BIND
 		call_with_variant_argsc_dv(static_cast<T *>(p_object), method, p_args, p_arg_count, r_error, get_default_arguments());
 #else
@@ -413,6 +431,9 @@ public:
 	}
 
 	virtual void validated_call(Object *p_object, const Variant **p_args, Variant *r_ret) const override {
+#ifdef TOOLS_ENABLED
+		ERR_FAIL_COND_MSG(p_object && p_object->is_extension_placeholder(), vformat("Cannot call method bind '%s' on placeholder instance.", MethodBind::get_name()));
+#endif
 #ifdef TYPED_METHOD_BIND
 		call_with_validated_object_instance_argsc(static_cast<T *>(p_object), method, p_args);
 #else
@@ -421,6 +442,9 @@ public:
 	}
 
 	virtual void ptrcall(Object *p_object, const void **p_args, void *r_ret) const override {
+#ifdef TOOLS_ENABLED
+		ERR_FAIL_COND_MSG(p_object && p_object->is_extension_placeholder(), vformat("Cannot call method bind '%s' on placeholder instance.", MethodBind::get_name()));
+#endif
 #ifdef TYPED_METHOD_BIND
 		call_with_ptr_argsc<T, P...>(static_cast<T *>(p_object), method, p_args);
 #else
@@ -490,6 +514,9 @@ public:
 
 	virtual Variant call(Object *p_object, const Variant **p_args, int p_arg_count, Callable::CallError &r_error) const override {
 		Variant ret;
+#ifdef TOOLS_ENABLED
+		ERR_FAIL_COND_V_MSG(p_object && p_object->is_extension_placeholder(), ret, vformat("Cannot call method bind '%s' on placeholder instance.", MethodBind::get_name()));
+#endif
 #ifdef TYPED_METHOD_BIND
 		call_with_variant_args_ret_dv(static_cast<T *>(p_object), method, p_args, p_arg_count, ret, r_error, get_default_arguments());
 #else
@@ -499,6 +526,9 @@ public:
 	}
 
 	virtual void validated_call(Object *p_object, const Variant **p_args, Variant *r_ret) const override {
+#ifdef TOOLS_ENABLED
+		ERR_FAIL_COND_MSG(p_object && p_object->is_extension_placeholder(), vformat("Cannot call method bind '%s' on placeholder instance.", MethodBind::get_name()));
+#endif
 #ifdef TYPED_METHOD_BIND
 		call_with_validated_object_instance_args_ret(static_cast<T *>(p_object), method, p_args, r_ret);
 #else
@@ -507,6 +537,9 @@ public:
 	}
 
 	virtual void ptrcall(Object *p_object, const void **p_args, void *r_ret) const override {
+#ifdef TOOLS_ENABLED
+		ERR_FAIL_COND_MSG(p_object && p_object->is_extension_placeholder(), vformat("Cannot call method bind '%s' on placeholder instance.", MethodBind::get_name()));
+#endif
 #ifdef TYPED_METHOD_BIND
 		call_with_ptr_args_ret<T, R, P...>(static_cast<T *>(p_object), method, p_args, r_ret);
 #else
@@ -577,6 +610,9 @@ public:
 
 	virtual Variant call(Object *p_object, const Variant **p_args, int p_arg_count, Callable::CallError &r_error) const override {
 		Variant ret;
+#ifdef TOOLS_ENABLED
+		ERR_FAIL_COND_V_MSG(p_object && p_object->is_extension_placeholder(), ret, vformat("Cannot call method bind '%s' on placeholder instance.", MethodBind::get_name()));
+#endif
 #ifdef TYPED_METHOD_BIND
 		call_with_variant_args_retc_dv(static_cast<T *>(p_object), method, p_args, p_arg_count, ret, r_error, get_default_arguments());
 #else
@@ -586,6 +622,9 @@ public:
 	}
 
 	virtual void validated_call(Object *p_object, const Variant **p_args, Variant *r_ret) const override {
+#ifdef TOOLS_ENABLED
+		ERR_FAIL_COND_MSG(p_object && p_object->is_extension_placeholder(), vformat("Cannot call method bind '%s' on placeholder instance.", MethodBind::get_name()));
+#endif
 #ifdef TYPED_METHOD_BIND
 		call_with_validated_object_instance_args_retc(static_cast<T *>(p_object), method, p_args, r_ret);
 #else
@@ -594,6 +633,9 @@ public:
 	}
 
 	virtual void ptrcall(Object *p_object, const void **p_args, void *r_ret) const override {
+#ifdef TOOLS_ENABLED
+		ERR_FAIL_COND_MSG(p_object && p_object->is_extension_placeholder(), vformat("Cannot call method bind '%s' on placeholder instance.", MethodBind::get_name()));
+#endif
 #ifdef TYPED_METHOD_BIND
 		call_with_ptr_args_retc<T, R, P...>(static_cast<T *>(p_object), method, p_args, r_ret);
 #else
diff --git a/core/object/object.h b/core/object/object.h
index 3974ef7295..621b0f8a08 100644
--- a/core/object/object.h
+++ b/core/object/object.h
@@ -358,8 +358,8 @@ struct ObjectGDExtension {
 
 #ifdef TOOLS_ENABLED
 	void *tracking_userdata = nullptr;
-	void (*track_instance)(void *p_userdata, void *p_instance);
-	void (*untrack_instance)(void *p_userdata, void *p_instance);
+	void (*track_instance)(void *p_userdata, void *p_instance) = nullptr;
+	void (*untrack_instance)(void *p_userdata, void *p_instance) = nullptr;
 #endif
 };