From c638238fae6c7a6d9c544fcec083ccb6ccc263b7 Mon Sep 17 00:00:00 2001
From: A Thousand Ships <96648715+AThousandShips@users.noreply.github.com>
Date: Sat, 26 Aug 2023 17:39:43 +0200
Subject: [PATCH] Add check to ensure registered classes are declared

Checks that all classes registered to `ClassDB` have been properly
declared with `GDCLASS`
---
 core/object/class_db.h | 3 +++
 core/object/object.h   | 3 +++
 2 files changed, 6 insertions(+)

diff --git a/core/object/class_db.h b/core/object/class_db.h
index 3aae3b452e69..57469f03d222 100644
--- a/core/object/class_db.h
+++ b/core/object/class_db.h
@@ -187,6 +187,7 @@ class ClassDB {
 	template <class T>
 	static void register_class(bool p_virtual = false) {
 		GLOBAL_LOCK_FUNCTION;
+		static_assert(TypesAreSame<typename T::self_type, T>::value, "Class not declared properly, please use GDCLASS.");
 		T::initialize_class();
 		ClassInfo *t = classes.getptr(T::get_class_static());
 		ERR_FAIL_COND(!t);
@@ -201,6 +202,7 @@ class ClassDB {
 	template <class T>
 	static void register_abstract_class() {
 		GLOBAL_LOCK_FUNCTION;
+		static_assert(TypesAreSame<typename T::self_type, T>::value, "Class not declared properly, please use GDCLASS.");
 		T::initialize_class();
 		ClassInfo *t = classes.getptr(T::get_class_static());
 		ERR_FAIL_COND(!t);
@@ -221,6 +223,7 @@ class ClassDB {
 	template <class T>
 	static void register_custom_instance_class() {
 		GLOBAL_LOCK_FUNCTION;
+		static_assert(TypesAreSame<typename T::self_type, T>::value, "Class not declared properly, please use GDCLASS.");
 		T::initialize_class();
 		ClassInfo *t = classes.getptr(T::get_class_static());
 		ERR_FAIL_COND(!t);
diff --git a/core/object/object.h b/core/object/object.h
index 318dbf98de7e..561e5b8fe3f3 100644
--- a/core/object/object.h
+++ b/core/object/object.h
@@ -382,6 +382,7 @@ private:
 	friend class ::ClassDB;                                                                                                                      \
                                                                                                                                                  \
 public:                                                                                                                                          \
+	typedef m_class self_type;                                                                                                                   \
 	static constexpr bool _class_is_enabled = !bool(GD_IS_DEFINED(ClassDB_Disable_##m_class)) && m_inherits::_class_is_enabled;                  \
 	virtual String get_class() const override {                                                                                                  \
 		if (_get_extension()) {                                                                                                                  \
@@ -557,6 +558,8 @@ class ScriptInstance;
 
 class Object {
 public:
+	typedef Object self_type;
+
 	enum ConnectFlags {
 		CONNECT_DEFERRED = 1,
 		CONNECT_PERSIST = 2, // hint for scene to save this connection