Fix cyclic references in GDScript 2.0

modules/gdscript/gdscript.cpp

@@ -808,6 +808,11 @@ String GDScript::_get_debug_path() const {
 }
 
 Error GDScript::reload(bool p_keep_state) {
+	if (reloading) {
+		return OK;
+	}
+	reloading = true;
+
 	bool has_instances;
 	{
 		MutexLock lock(GDScriptLanguage::singleton->mutex);
@@ -830,6 +835,7 @@ Error GDScript::reload(bool p_keep_state) {
 	// Loading a template, don't parse.
 #ifdef TOOLS_ENABLED
 	if (EditorPaths::get_singleton() && basedir.begins_with(EditorPaths::get_singleton()->get_project_script_templates_dir())) {
+		reloading = false;
 		return OK;
 	}
 #endif
@@ -839,11 +845,10 @@ Error GDScript::reload(bool p_keep_state) {
 		if (source_path.is_empty()) {
 			source_path = get_path();
 		}
-		if (!source_path.is_empty()) {
-			MutexLock lock(GDScriptCache::singleton->lock);
-			if (!GDScriptCache::singleton->shallow_gdscript_cache.has(source_path)) {
-				GDScriptCache::singleton->shallow_gdscript_cache[source_path] = this;
-			}
+		Ref<GDScript> cached_script = GDScriptCache::get_cached_script(source_path);
+		if (!source_path.is_empty() && cached_script.is_null()) {
+			MutexLock lock(GDScriptCache::singleton->mutex);
+			GDScriptCache::singleton->shallow_gdscript_cache[source_path] = Ref<GDScript>(this);
 		}
 	}
 
@@ -856,6 +861,7 @@ Error GDScript::reload(bool p_keep_state) {
 		}
 		// TODO: Show all error messages.
 		_err_print_error("GDScript::reload", path.is_empty() ? "built-in" : (const char *)path.utf8().get_data(), parser.get_errors().front()->get().line, ("Parse Error: " + parser.get_errors().front()->get().message).utf8().get_data(), false, ERR_HANDLER_SCRIPT);
+		reloading = false;
 		return ERR_PARSE_ERROR;
 	}
 
@@ -872,6 +878,7 @@ Error GDScript::reload(bool p_keep_state) {
 			_err_print_error("GDScript::reload", path.is_empty() ? "built-in" : (const char *)path.utf8().get_data(), e->get().line, ("Parse Error: " + e->get().message).utf8().get_data(), false, ERR_HANDLER_SCRIPT);
 			e = e->next();
 		}
+		reloading = false;
 		return ERR_PARSE_ERROR;
 	}
 
@@ -886,8 +893,10 @@ Error GDScript::reload(bool p_keep_state) {
 				GDScriptLanguage::get_singleton()->debug_break_parse(_get_debug_path(), compiler.get_error_line(), "Parser Error: " + compiler.get_error());
 			}
 			_err_print_error("GDScript::reload", path.is_empty() ? "built-in" : (const char *)path.utf8().get_data(), compiler.get_error_line(), ("Compile Error: " + compiler.get_error()).utf8().get_data(), false, ERR_HANDLER_SCRIPT);
+			reloading = false;
 			return ERR_COMPILATION_FAILED;
 		} else {
+			reloading = false;
 			return err;
 		}
 	}
@@ -900,6 +909,7 @@ Error GDScript::reload(bool p_keep_state) {
 	}
 #endif
 
+	reloading = false;
 	return OK;
 }
 
@@ -1006,16 +1016,22 @@ Error GDScript::load_byte_code(const String &p_path) {
 }
 
 void GDScript::set_path(const String &p_path, bool p_take_over) {
+	String old_path = path;
 	if (is_root_script()) {
 		Script::set_path(p_path, p_take_over);
 	}
 	this->path = p_path;
+	GDScriptCache::move_script(old_path, p_path);
 	for (KeyValue<StringName, Ref<GDScript>> &kv : subclasses) {
 		kv.value->set_path(p_path, p_take_over);
 	}
 }
 
 Error GDScript::load_source_code(const String &p_path) {
+	if (p_path.is_empty() || ResourceLoader::get_resource_type(p_path.get_slice("::", 0)) == "PackedScene") {
+		return OK;
+	}
+
 	Vector<uint8_t> sourcef;
 	Error err;
 	Ref<FileAccess> f = FileAccess::open(p_path, FileAccess::READ, &err);
@@ -1133,6 +1149,78 @@ GDScript *GDScript::get_root_script() {
 	return result;
 }
 
+RBSet<GDScript *> GDScript::get_dependencies() {
+	RBSet<GDScript *> dependencies;
+
+	_get_dependencies(dependencies, this);
+	dependencies.erase(this);
+
+	return dependencies;
+}
+
+RBSet<GDScript *> GDScript::get_inverted_dependencies() {
+	RBSet<GDScript *> inverted_dependencies;
+
+	List<GDScript *> scripts;
+	{
+		MutexLock lock(GDScriptLanguage::singleton->mutex);
+
+		SelfList<GDScript> *elem = GDScriptLanguage::singleton->script_list.first();
+		while (elem) {
+			scripts.push_back(elem->self());
+			elem = elem->next();
+		}
+	}
+
+	for (GDScript *scr : scripts) {
+		if (scr == nullptr || scr == this || scr->destructing) {
+			continue;
+		}
+
+		RBSet<GDScript *> scr_dependencies = scr->get_dependencies();
+		if (scr_dependencies.has(this)) {
+			inverted_dependencies.insert(scr);
+		}
+	}
+
+	return inverted_dependencies;
+}
+
+RBSet<GDScript *> GDScript::get_must_clear_dependencies() {
+	RBSet<GDScript *> dependencies = get_dependencies();
+	RBSet<GDScript *> must_clear_dependencies;
+	HashMap<GDScript *, RBSet<GDScript *>> inverted_dependencies;
+
+	for (GDScript *E : dependencies) {
+		inverted_dependencies.insert(E, E->get_inverted_dependencies());
+	}
+
+	RBSet<GDScript *> cant_clear;
+	for (KeyValue<GDScript *, RBSet<GDScript *>> &E : inverted_dependencies) {
+		for (GDScript *F : E.value) {
+			if (!dependencies.has(F)) {
+				cant_clear.insert(E.key);
+				for (GDScript *G : E.key->get_dependencies()) {
+					cant_clear.insert(G);
+				}
+				break;
+			}
+		}
+	}
+
+	for (KeyValue<GDScript *, RBSet<GDScript *>> &E : inverted_dependencies) {
+		if (cant_clear.has(E.key) || ScriptServer::is_global_class(E.key->get_fully_qualified_name())) {
+			continue;
+		}
+		must_clear_dependencies.insert(E.key);
+	}
+
+	cant_clear.clear();
+	dependencies.clear();
+	inverted_dependencies.clear();
+	return must_clear_dependencies;
+}
+
 bool GDScript::has_script_signal(const StringName &p_signal) const {
 	if (_signals.has(p_signal)) {
 		return true;
@@ -1194,6 +1282,69 @@ String GDScript::_get_gdscript_reference_class_name(const GDScript *p_gdscript)
 	return class_name;
 }
 
+GDScript *GDScript::_get_gdscript_from_variant(const Variant &p_variant) {
+	Variant::Type type = p_variant.get_type();
+	if (type != Variant::Type::OBJECT)
+		return nullptr;
+
+	Object *obj = p_variant;
+	if (obj == nullptr) {
+		return nullptr;
+	}
+
+	return Object::cast_to<GDScript>(obj);
+}
+
+void GDScript::_get_dependencies(RBSet<GDScript *> &p_dependencies, const GDScript *p_except) {
+	if (skip_dependencies || p_dependencies.has(this)) {
+		return;
+	}
+	p_dependencies.insert(this);
+
+	for (const KeyValue<StringName, GDScriptFunction *> &E : member_functions) {
+		if (E.value == nullptr) {
+			continue;
+		}
+		for (const Variant &V : E.value->constants) {
+			GDScript *scr = _get_gdscript_from_variant(V);
+			if (scr != nullptr && scr != p_except) {
+				scr->_get_dependencies(p_dependencies, p_except);
+			}
+		}
+	}
+
+	if (implicit_initializer) {
+		for (const Variant &V : implicit_initializer->constants) {
+			GDScript *scr = _get_gdscript_from_variant(V);
+			if (scr != nullptr && scr != p_except) {
+				scr->_get_dependencies(p_dependencies, p_except);
+			}
+		}
+	}
+
+	if (implicit_ready) {
+		for (const Variant &V : implicit_ready->constants) {
+			GDScript *scr = _get_gdscript_from_variant(V);
+			if (scr != nullptr && scr != p_except) {
+				scr->_get_dependencies(p_dependencies, p_except);
+			}
+		}
+	}
+
+	for (KeyValue<StringName, Ref<GDScript>> &E : subclasses) {
+		if (E.value != p_except) {
+			E.value->_get_dependencies(p_dependencies, p_except);
+		}
+	}
+
+	for (const KeyValue<StringName, Variant> &E : constants) {
+		GDScript *scr = _get_gdscript_from_variant(E.value);
+		if (scr != nullptr && scr != p_except) {
+			scr->_get_dependencies(p_dependencies, p_except);
+		}
+	}
+}
+
 GDScript::GDScript() :
 		script_list(this) {
 #ifdef DEBUG_ENABLED
@@ -1253,33 +1404,58 @@ void GDScript::_init_rpc_methods_properties() {
 	}
 }
 
-GDScript::~GDScript() {
-	{
-		MutexLock lock(GDScriptLanguage::get_singleton()->mutex);
+void GDScript::clear() {
+	if (clearing) {
+		return;
+	}
+	clearing = true;
 
-		while (SelfList<GDScriptFunctionState> *E = pending_func_states.first()) {
-			// Order matters since clearing the stack may already cause
-			// the GDSCriptFunctionState to be destroyed and thus removed from the list.
-			pending_func_states.remove(E);
-			E->self()->_clear_stack();
+	RBSet<GDScript *> must_clear_dependencies = get_must_clear_dependencies();
+	HashMap<GDScript *, ObjectID> must_clear_dependencies_objectids;
+
+	// Log the objectids before clearing, as a cascade of clear could
+	// remove instances that are still in the clear loop
+	for (GDScript *E : must_clear_dependencies) {
+		must_clear_dependencies_objectids.insert(E, E->get_instance_id());
+	}
+
+	for (GDScript *E : must_clear_dependencies) {
+		Object *obj = ObjectDB::get_instance(must_clear_dependencies_objectids[E]);
+		if (obj == nullptr) {
+			continue;
 		}
+
+		E->skip_dependencies = true;
+		E->clear();
+		E->skip_dependencies = false;
+		GDScriptCache::remove_script(E->get_path());
 	}
 
+	RBSet<StringName> member_function_names;
 	for (const KeyValue<StringName, GDScriptFunction *> &E : member_functions) {
-		memdelete(E.value);
+		member_function_names.insert(E.key);
+	}
+	for (const StringName &E : member_function_names) {
+		if (member_functions.has(E)) {
+			memdelete(member_functions[E]);
+		}
+	}
+	member_function_names.clear();
+	member_functions.clear();
+
+	for (KeyValue<StringName, GDScript::MemberInfo> &E : member_indices) {
+		E.value.data_type.script_type_ref = Ref<Script>();
 	}
 
 	if (implicit_initializer) {
 		memdelete(implicit_initializer);
 	}
+	implicit_initializer = nullptr;
 
 	if (implicit_ready) {
 		memdelete(implicit_ready);
 	}
-
-	if (GDScriptCache::singleton) { // Cache may have been already destroyed at engine shutdown.
-		GDScriptCache::remove_script(get_path());
-	}
+	implicit_ready = nullptr;
 
 	_save_orphaned_subclasses();
 
@@ -1289,6 +1465,27 @@ GDScript::~GDScript() {
 		_clear_doc();
 	}
 #endif
+	clearing = false;
+}
+
+GDScript::~GDScript() {
+	if (destructing) {
+		return;
+	}
+	destructing = true;
+
+	clear();
+
+	{
+		MutexLock lock(GDScriptLanguage::get_singleton()->mutex);
+
+		while (SelfList<GDScriptFunctionState> *E = pending_func_states.first()) {
+			// Order matters since clearing the stack may already cause
+			// the GDScriptFunctionState to be destroyed and thus removed from the list.
+			pending_func_states.remove(E);
+			E->self()->_clear_stack();
+		}
+	}
 
 #ifdef DEBUG_ENABLED
 	{
@@ -1297,6 +1494,10 @@ GDScript::~GDScript() {
 		GDScriptLanguage::get_singleton()->script_list.remove(&script_list);
 	}
 #endif
+
+	if (GDScriptCache::singleton) { // Cache may have been already destroyed at engine shutdown.
+		GDScriptCache::remove_script(get_path());
+	}
 }
 
 //////////////////////////////
@@ -2336,26 +2537,27 @@ GDScriptLanguage::~GDScriptLanguage() {
 	// Clear dependencies between scripts, to ensure cyclic references are broken (to avoid leaks at exit).
 	SelfList<GDScript> *s = script_list.first();
 	while (s) {
-		GDScript *scr = s->self();
 		// This ensures the current script is not released before we can check what's the next one
 		// in the list (we can't get the next upfront because we don't know if the reference breaking
 		// will cause it -or any other after it, for that matter- to be released so the next one
 		// is not the same as before).
-		scr->reference();
-
-		for (KeyValue<StringName, GDScriptFunction *> &E : scr->member_functions) {
-			GDScriptFunction *func = E.value;
-			for (int i = 0; i < func->argument_types.size(); i++) {
-				func->argument_types.write[i].script_type_ref = Ref<Script>();
+		Ref<GDScript> scr = s->self();
+		if (scr.is_valid()) {
+			for (KeyValue<StringName, GDScriptFunction *> &E : scr->member_functions) {
+				GDScriptFunction *func = E.value;
+				for (int i = 0; i < func->argument_types.size(); i++) {
+					func->argument_types.write[i].script_type_ref = Ref<Script>();
+				}
+				func->return_type.script_type_ref = Ref<Script>();
+			}
+			for (KeyValue<StringName, GDScript::MemberInfo> &E : scr->member_indices) {
+				E.value.data_type.script_type_ref = Ref<Script>();
 			}
-			func->return_type.script_type_ref = Ref<Script>();
-		}
-		for (KeyValue<StringName, GDScript::MemberInfo> &E : scr->member_indices) {
-			E.value.data_type.script_type_ref = Ref<Script>();
-		}
 
+			// Clear backup for scripts that could slip out of the cyclic reference check
+			scr->clear();
+		}
 		s = s->next();
-		scr->unreference();
 	}
 
 	singleton = nullptr;
@@ -2379,6 +2581,27 @@ Ref<GDScript> GDScriptLanguage::get_orphan_subclass(const String &p_qualified_na
 	return Ref<GDScript>(Object::cast_to<GDScript>(obj));
 }
 
+Ref<GDScript> GDScriptLanguage::get_script_by_fully_qualified_name(const String &p_name) {
+	{
+		MutexLock lock(mutex);
+
+		SelfList<GDScript> *elem = script_list.first();
+		while (elem) {
+			GDScript *scr = elem->self();
+			scr = scr->find_class(p_name);
+			if (scr != nullptr) {
+				return scr;
+			}
+			elem = elem->next();
+		}
+	}
+
+	Ref<GDScript> scr;
+	scr.instantiate();
+	scr->fully_qualified_name = p_name;
+	return scr;
+}
+
 /*************** RESOURCE ***************/
 
 Ref<Resource> ResourceFormatLoaderGDScript::load(const String &p_path, const String &p_original_path, Error *r_error, bool p_use_sub_threads, float *r_progress, CacheMode p_cache_mode) {

modules/gdscript/gdscript.h

@@ -61,6 +61,8 @@ class GDScript : public Script {
 	GDCLASS(GDScript, Script);
 	bool tool = false;
 	bool valid = false;
+	bool reloading = false;
+	bool skip_dependencies = false;
 
 	struct MemberInfo {
 		int index = 0;
@@ -124,6 +126,8 @@ class GDScript : public Script {
 
 	int subclass_count = 0;
 	RBSet<Object *> instances;
+	bool destructing = false;
+	bool clearing = false;
 	//exported members
 	String source;
 	String path;
@@ -163,6 +167,9 @@ class GDScript : public Script {
 	// This method will map the class name from "RefCounted" to "MyClass.InnerClass".
 	static String _get_gdscript_reference_class_name(const GDScript *p_gdscript);
 
+	GDScript *_get_gdscript_from_variant(const Variant &p_variant);
+	void _get_dependencies(RBSet<GDScript *> &p_dependencies, const GDScript *p_except);
+
 protected:
 	bool _get(const StringName &p_name, Variant &r_ret) const;
 	bool _set(const StringName &p_name, const Variant &p_value);
@@ -173,6 +180,8 @@ protected:
 	static void _bind_methods();
 
 public:
+	void clear();
+
 	virtual bool is_valid() const override { return valid; }
 
 	bool inherits_script(const Ref<Script> &p_script) const override;
@@ -193,6 +202,10 @@ public:
 	const Ref<GDScriptNativeClass> &get_native() const { return native; }
 	const String &get_script_class_name() const { return name; }
 
+	RBSet<GDScript *> get_dependencies();
+	RBSet<GDScript *> get_inverted_dependencies();
+	RBSet<GDScript *> get_must_clear_dependencies();
+
 	virtual bool has_script_signal(const StringName &p_signal) const override;
 	virtual void get_script_signal_list(List<MethodInfo> *r_signals) const override;
 
@@ -270,6 +283,7 @@ class GDScriptInstance : public ScriptInstance {
 	friend class GDScriptLambdaCallable;
 	friend class GDScriptLambdaSelfCallable;
 	friend class GDScriptCompiler;
+	friend class GDScriptCache;
 	friend struct GDScriptUtilityFunctionsDefinitions;
 
 	ObjectID owner_id;
@@ -518,6 +532,8 @@ public:
 	void add_orphan_subclass(const String &p_qualified_name, const ObjectID &p_subclass);
 	Ref<GDScript> get_orphan_subclass(const String &p_qualified_name);
 
+	Ref<GDScript> get_script_by_fully_qualified_name(const String &p_name);
+
 	GDScriptLanguage();
 	~GDScriptLanguage();
 };

modules/gdscript/gdscript_analyzer.cpp

@@ -39,6 +39,7 @@
 #include "core/templates/hash_map.h"
 #include "gdscript.h"
 #include "gdscript_utility_functions.h"
+#include "scene/resources/packed_scene.h"
 
 static MethodInfo info_from_utility_func(const StringName &p_function) {
 	ERR_FAIL_COND_V(!Variant::has_utility_function(p_function), MethodInfo());
@@ -3103,7 +3104,7 @@ void GDScriptAnalyzer::reduce_identifier(GDScriptParser::IdentifierNode *p_ident
 			GDScriptParser::DataType result;
 			result.kind = GDScriptParser::DataType::NATIVE;
 			result.type_source = GDScriptParser::DataType::ANNOTATED_EXPLICIT;
-			if (autoload.path.to_lower().ends_with(GDScriptLanguage::get_singleton()->get_extension())) {
+			if (ResourceLoader::get_resource_type(autoload.path) == "GDScript") {
 				Ref<GDScriptParserRef> singl_parser = get_parser_for(autoload.path);
 				if (singl_parser.is_valid()) {
 					Error err = singl_parser->raise_status(GDScriptParserRef::INTERFACE_SOLVED);
@@ -3111,6 +3112,34 @@ void GDScriptAnalyzer::reduce_identifier(GDScriptParser::IdentifierNode *p_ident
 						result = type_from_metatype(singl_parser->get_parser()->head->get_datatype());
 					}
 				}
+			} else if (ResourceLoader::get_resource_type(autoload.path) == "PackedScene") {
+				Error err = OK;
+				Ref<PackedScene> scene = GDScriptCache::get_packed_scene(autoload.path, err);
+				if (err == OK && scene->get_state().is_valid()) {
+					Ref<SceneState> state = scene->get_state();
+					if (state->get_node_count() > 0) {
+						const int ROOT_NODE = 0;
+						for (int i = 0; i < state->get_node_property_count(ROOT_NODE); i++) {
+							if (state->get_node_property_name(ROOT_NODE, i) != SNAME("script")) {
+								continue;
+							}
+
+							Ref<GDScript> scr = state->get_node_property_value(ROOT_NODE, i);
+							if (scr.is_null()) {
+								continue;
+							}
+
+							Ref<GDScriptParserRef> singl_parser = get_parser_for(scr->get_path());
+							if (singl_parser.is_valid()) {
+								err = singl_parser->raise_status(GDScriptParserRef::INTERFACE_SOLVED);
+								if (err == OK) {
+									result = type_from_metatype(singl_parser->get_parser()->head->get_datatype());
+								}
+							}
+							break;
+						}
+					}
+				}
 			}
 			result.is_constant = true;
 			p_identifier->set_datatype(result);
@@ -3236,9 +3265,28 @@ void GDScriptAnalyzer::reduce_preload(GDScriptParser::PreloadNode *p_preload) {
 			}
 		} else {
 			// TODO: Don't load if validating: use completion cache.
-			p_preload->resource = ResourceLoader::load(p_preload->resolved_path);
-			if (p_preload->resource.is_null()) {
-				push_error(vformat(R"(Could not preload resource file "%s".)", p_preload->resolved_path), p_preload->path);
+
+			// Must load GDScript and PackedScenes separately to permit cyclic references
+			// as ResourceLoader::load() detect and reject those.
+			if (ResourceLoader::get_resource_type(p_preload->resolved_path) == "GDScript") {
+				Error err = OK;
+				Ref<GDScript> res = GDScriptCache::get_shallow_script(p_preload->resolved_path, err, parser->script_path);
+				p_preload->resource = res;
+				if (err != OK) {
+					push_error(vformat(R"(Could not preload resource script "%s".)", p_preload->resolved_path), p_preload->path);
+				}
+			} else if (ResourceLoader::get_resource_type(p_preload->resolved_path) == "PackedScene") {
+				Error err = OK;
+				Ref<PackedScene> res = GDScriptCache::get_packed_scene(p_preload->resolved_path, err, parser->script_path);
+				p_preload->resource = res;
+				if (err != OK) {
+					push_error(vformat(R"(Could not preload resource scene "%s".)", p_preload->resolved_path), p_preload->path);
+				}
+			} else {
+				p_preload->resource = ResourceLoader::load(p_preload->resolved_path);
+				if (p_preload->resource.is_null()) {
+					push_error(vformat(R"(Could not preload resource file "%s".)", p_preload->resolved_path), p_preload->path);
+				}
 			}
 		}
 	}
@@ -3280,6 +3328,17 @@ void GDScriptAnalyzer::reduce_subscript(GDScriptParser::SubscriptNode *p_subscri
 			// Just try to get it.
 			bool valid = false;
 			Variant value = p_subscript->base->reduced_value.get_named(p_subscript->attribute->name, valid);
+
+			// If it's a GDScript instance, try to get the full script. Maybe it's not still completely loaded.
+			Ref<GDScript> gdscr = Ref<GDScript>(p_subscript->base->reduced_value);
+			if (!valid && gdscr.is_valid()) {
+				Error err = OK;
+				GDScriptCache::get_full_script(gdscr->get_path(), err);
+				if (err == OK) {
+					value = p_subscript->base->reduced_value.get_named(p_subscript->attribute->name, valid);
+				}
+			}
+
 			if (!valid) {
 				push_error(vformat(R"(Cannot get member "%s" from "%s".)", p_subscript->attribute->name, p_subscript->base->reduced_value), p_subscript->index);
 				result_type.kind = GDScriptParser::DataType::VARIANT;
@@ -3662,50 +3721,43 @@ GDScriptParser::DataType GDScriptAnalyzer::type_from_variant(const Variant &p_va
 			scr = obj->get_script();
 		}
 		if (scr.is_valid()) {
-			if (scr->is_valid()) {
-				result.script_type = scr;
-				result.script_path = scr->get_path();
-				Ref<GDScript> gds = scr;
-				if (gds.is_valid()) {
-					result.kind = GDScriptParser::DataType::CLASS;
-					// This might be an inner class, so we want to get the parser for the root.
-					// But still get the inner class from that tree.
-					GDScript *current = gds.ptr();
-					List<StringName> class_chain;
-					while (current->_owner) {
-						// Push to front so it's in reverse.
-						class_chain.push_front(current->name);
-						current = current->_owner;
-					}
-
-					Ref<GDScriptParserRef> ref = get_parser_for(current->get_path());
-					if (ref.is_null()) {
-						push_error("Could not find script in path.", p_source);
-						GDScriptParser::DataType error_type;
-						error_type.kind = GDScriptParser::DataType::VARIANT;
-						return error_type;
-					}
-					ref->raise_status(GDScriptParserRef::INTERFACE_SOLVED);
+			result.script_type = scr;
+			result.script_path = scr->get_path();
+			Ref<GDScript> gds = scr;
+			if (gds.is_valid()) {
+				result.kind = GDScriptParser::DataType::CLASS;
+				// This might be an inner class, so we want to get the parser for the root.
+				// But still get the inner class from that tree.
+				GDScript *current = gds.ptr();
+				List<StringName> class_chain;
+				while (current->_owner) {
+					// Push to front so it's in reverse.
+					class_chain.push_front(current->name);
+					current = current->_owner;
+				}
 
-					GDScriptParser::ClassNode *found = ref->get_parser()->head;
+				Ref<GDScriptParserRef> ref = get_parser_for(current->get_path());
+				if (ref.is_null()) {
+					push_error("Could not find script in path.", p_source);
+					GDScriptParser::DataType error_type;
+					error_type.kind = GDScriptParser::DataType::VARIANT;
+					return error_type;
+				}
+				ref->raise_status(GDScriptParserRef::INTERFACE_SOLVED);
 
-					// It should be okay to assume this exists, since we have a complete script already.
-					for (const StringName &E : class_chain) {
-						found = found->get_member(E).m_class;
-					}
+				GDScriptParser::ClassNode *found = ref->get_parser()->head;
 
-					result.class_type = found;
-					result.script_path = ref->get_parser()->script_path;
-				} else {
-					result.kind = GDScriptParser::DataType::SCRIPT;
+				// It should be okay to assume this exists, since we have a complete script already.
+				for (const StringName &E : class_chain) {
+					found = found->get_member(E).m_class;
 				}
-				result.native_type = scr->get_instance_base_type();
+
+				result.class_type = found;
+				result.script_path = ref->get_parser()->script_path;
 			} else {
-				push_error(vformat(R"(Constant value uses script from "%s" which is loaded but not compiled.)", scr->get_path()), p_source);
-				result.kind = GDScriptParser::DataType::VARIANT;
-				result.type_source = GDScriptParser::DataType::UNDETECTED;
-				result.is_meta_type = false;
+				result.kind = GDScriptParser::DataType::SCRIPT;
 			}
+			result.native_type = scr->get_instance_base_type();
 		} else {
 			result.kind = GDScriptParser::DataType::NATIVE;
 			if (result.native_type == GDScriptNativeClass::get_class_static()) {

modules/gdscript/gdscript_cache.cpp

@@ -36,6 +36,7 @@
 #include "gdscript_analyzer.h"
 #include "gdscript_compiler.h"
 #include "gdscript_parser.h"
+#include "scene/resources/packed_scene.h"
 
 bool GDScriptParserRef::is_valid() const {
 	return parser != nullptr;
@@ -96,27 +97,88 @@ Error GDScriptParserRef::raise_status(Status p_new_status) {
 	return result;
 }
 
-GDScriptParserRef::~GDScriptParserRef() {
+void GDScriptParserRef::clear() {
+	if (cleared) {
+		return;
+	}
+	cleared = true;
+
 	if (parser != nullptr) {
 		memdelete(parser);
 	}
+
 	if (analyzer != nullptr) {
 		memdelete(analyzer);
 	}
-	MutexLock lock(GDScriptCache::singleton->lock);
+}
+
+GDScriptParserRef::~GDScriptParserRef() {
+	clear();
+
+	MutexLock lock(GDScriptCache::singleton->mutex);
 	GDScriptCache::singleton->parser_map.erase(path);
 }
 
 GDScriptCache *GDScriptCache::singleton = nullptr;
 
+void GDScriptCache::move_script(const String &p_from, const String &p_to) {
+	if (singleton == nullptr) {
+		return;
+	}
+
+	MutexLock lock(singleton->mutex);
+
+	for (KeyValue<String, HashSet<String>> &E : singleton->packed_scene_dependencies) {
+		if (E.value.has(p_from)) {
+			E.value.insert(p_to);
+			E.value.erase(p_from);
+		}
+	}
+
+	if (singleton->parser_map.has(p_from) && !p_from.is_empty()) {
+		singleton->parser_map[p_to] = singleton->parser_map[p_from];
+	}
+	singleton->parser_map.erase(p_from);
+
+	if (singleton->shallow_gdscript_cache.has(p_from) && !p_from.is_empty()) {
+		singleton->shallow_gdscript_cache[p_to] = singleton->shallow_gdscript_cache[p_from];
+	}
+	singleton->shallow_gdscript_cache.erase(p_from);
+
+	if (singleton->full_gdscript_cache.has(p_from) && !p_from.is_empty()) {
+		singleton->full_gdscript_cache[p_to] = singleton->full_gdscript_cache[p_from];
+	}
+	singleton->full_gdscript_cache.erase(p_from);
+}
+
 void GDScriptCache::remove_script(const String &p_path) {
-	MutexLock lock(singleton->lock);
+	if (singleton == nullptr) {
+		return;
+	}
+
+	MutexLock lock(singleton->mutex);
+
+	for (KeyValue<String, HashSet<String>> &E : singleton->packed_scene_dependencies) {
+		if (!E.value.has(p_path)) {
+			continue;
+		}
+		E.value.erase(p_path);
+	}
+
+	GDScriptCache::clear_unreferenced_packed_scenes();
+
+	if (singleton->parser_map.has(p_path)) {
+		singleton->parser_map[p_path]->clear();
+		singleton->parser_map.erase(p_path);
+	}
+
+	singleton->dependencies.erase(p_path);
 	singleton->shallow_gdscript_cache.erase(p_path);
 	singleton->full_gdscript_cache.erase(p_path);
 }
 
 Ref<GDScriptParserRef> GDScriptCache::get_parser(const String &p_path, GDScriptParserRef::Status p_status, Error &r_error, const String &p_owner) {
-	MutexLock lock(singleton->lock);
+	MutexLock lock(singleton->mutex);
 	Ref<GDScriptParserRef> ref;
 	if (!p_owner.is_empty()) {
 		singleton->dependencies[p_owner].insert(p_path);
@@ -163,7 +225,7 @@ String GDScriptCache::get_source_code(const String &p_path) {
 }
 
 Ref<GDScript> GDScriptCache::get_shallow_script(const String &p_path, Error &r_error, const String &p_owner) {
-	MutexLock lock(singleton->lock);
+	MutexLock lock(singleton->mutex);
 	if (!p_owner.is_empty()) {
 		singleton->dependencies[p_owner].insert(p_path);
 	}
@@ -185,12 +247,12 @@ Ref<GDScript> GDScriptCache::get_shallow_script(const String &p_path, Error &r_e
 	script->load_source_code(p_path);
 	GDScriptCompiler::make_scripts(script.ptr(), parser_ref->get_parser()->get_tree(), true);
 
-	singleton->shallow_gdscript_cache[p_path] = script.ptr();
+	singleton->shallow_gdscript_cache[p_path] = script;
 	return script;
 }
 
 Ref<GDScript> GDScriptCache::get_full_script(const String &p_path, Error &r_error, const String &p_owner, bool p_update_from_disk) {
-	MutexLock lock(singleton->lock);
+	MutexLock lock(singleton->mutex);
 
 	if (!p_owner.is_empty()) {
 		singleton->dependencies[p_owner].insert(p_path);
@@ -220,19 +282,21 @@ Ref<GDScript> GDScriptCache::get_full_script(const String &p_path, Error &r_erro
 		return script;
 	}
 
+	singleton->full_gdscript_cache[p_path] = script;
+	singleton->shallow_gdscript_cache.erase(p_path);
+
 	r_error = script->reload(true);
 	if (r_error) {
+		singleton->shallow_gdscript_cache[p_path] = script;
+		singleton->full_gdscript_cache.erase(p_path);
 		return script;
 	}
 
-	singleton->full_gdscript_cache[p_path] = script.ptr();
-	singleton->shallow_gdscript_cache.erase(p_path);
-
 	return script;
 }
 
 Ref<GDScript> GDScriptCache::get_cached_script(const String &p_path) {
-	MutexLock lock(singleton->lock);
+	MutexLock lock(singleton->mutex);
 
 	if (singleton->full_gdscript_cache.has(p_path)) {
 		return singleton->full_gdscript_cache[p_path];
@@ -246,11 +310,11 @@ Ref<GDScript> GDScriptCache::get_cached_script(const String &p_path) {
 }
 
 Error GDScriptCache::finish_compiling(const String &p_owner) {
-	MutexLock lock(singleton->lock);
+	MutexLock lock(singleton->mutex);
 
 	// Mark this as compiled.
 	Ref<GDScript> script = get_cached_script(p_owner);
-	singleton->full_gdscript_cache[p_owner] = script.ptr();
+	singleton->full_gdscript_cache[p_owner] = script;
 	singleton->shallow_gdscript_cache.erase(p_owner);
 
 	HashSet<String> depends = singleton->dependencies[p_owner];
@@ -271,13 +335,73 @@ Error GDScriptCache::finish_compiling(const String &p_owner) {
 	return err;
 }
 
+Ref<PackedScene> GDScriptCache::get_packed_scene(const String &p_path, Error &r_error, const String &p_owner) {
+	MutexLock lock(singleton->mutex);
+
+	if (singleton->packed_scene_cache.has(p_path)) {
+		singleton->packed_scene_dependencies[p_path].insert(p_owner);
+		return singleton->packed_scene_cache[p_path];
+	}
+
+	Ref<PackedScene> scene;
+	scene.instantiate();
+
+	r_error = OK;
+	if (p_path.is_empty()) {
+		r_error = ERR_FILE_BAD_PATH;
+		return scene;
+	}
+
+	scene->set_path(p_path);
+	singleton->packed_scene_cache[p_path] = scene;
+	singleton->packed_scene_dependencies[p_path].insert(p_owner);
+
+	scene->recreate_state();
+	scene->reload_from_file();
+	return scene;
+}
+
+void GDScriptCache::clear_unreferenced_packed_scenes() {
+	if (singleton == nullptr) {
+		return;
+	}
+
+	MutexLock lock(singleton->mutex);
+
+	for (KeyValue<String, HashSet<String>> &E : singleton->packed_scene_dependencies) {
+		if (E.value.size() > 0 || !ResourceLoader::is_imported(E.key)) {
+			continue;
+		}
+
+		singleton->packed_scene_dependencies.erase(E.key);
+		singleton->packed_scene_cache.erase(E.key);
+	}
+}
+
 GDScriptCache::GDScriptCache() {
 	singleton = this;
 }
 
 GDScriptCache::~GDScriptCache() {
+	destructing = true;
+
+	RBSet<Ref<GDScriptParserRef>> parser_map_refs;
+	for (KeyValue<String, GDScriptParserRef *> &E : parser_map) {
+		parser_map_refs.insert(E.value);
+	}
+
+	for (Ref<GDScriptParserRef> &E : parser_map_refs) {
+		if (E.is_valid())
+			E->clear();
+	}
+
+	parser_map_refs.clear();
 	parser_map.clear();
 	shallow_gdscript_cache.clear();
 	full_gdscript_cache.clear();
+
+	packed_scene_cache.clear();
+	packed_scene_dependencies.clear();
+
 	singleton = nullptr;
 }

modules/gdscript/gdscript_cache.h

@@ -36,6 +36,7 @@
 #include "core/templates/hash_map.h"
 #include "core/templates/hash_set.h"
 #include "gdscript.h"
+#include "scene/resources/packed_scene.h"
 
 class GDScriptAnalyzer;
 class GDScriptParser;
@@ -56,6 +57,7 @@ private:
 	Status status = EMPTY;
 	Error result = OK;
 	String path;
+	bool cleared = false;
 
 	friend class GDScriptCache;
 
@@ -64,6 +66,7 @@ public:
 	Status get_status() const;
 	GDScriptParser *get_parser() const;
 	Error raise_status(Status p_new_status);
+	void clear();
 
 	GDScriptParserRef() {}
 	~GDScriptParserRef();
@@ -72,19 +75,25 @@ public:
 class GDScriptCache {
 	// String key is full path.
 	HashMap<String, GDScriptParserRef *> parser_map;
-	HashMap<String, GDScript *> shallow_gdscript_cache;
-	HashMap<String, GDScript *> full_gdscript_cache;
+	HashMap<String, Ref<GDScript>> shallow_gdscript_cache;
+	HashMap<String, Ref<GDScript>> full_gdscript_cache;
 	HashMap<String, HashSet<String>> dependencies;
+	HashMap<String, Ref<PackedScene>> packed_scene_cache;
+	HashMap<String, HashSet<String>> packed_scene_dependencies;
 
 	friend class GDScript;
 	friend class GDScriptParserRef;
+	friend class GDScriptInstance;
 
 	static GDScriptCache *singleton;
 
-	Mutex lock;
-	static void remove_script(const String &p_path);
+	bool destructing = false;
+
+	Mutex mutex;
 
 public:
+	static void move_script(const String &p_from, const String &p_to);
+	static void remove_script(const String &p_path);
 	static Ref<GDScriptParserRef> get_parser(const String &p_path, GDScriptParserRef::Status status, Error &r_error, const String &p_owner = String());
 	static String get_source_code(const String &p_path);
 	static Ref<GDScript> get_shallow_script(const String &p_path, Error &r_error, const String &p_owner = String());
@@ -92,6 +101,16 @@ public:
 	static Ref<GDScript> get_cached_script(const String &p_path);
 	static Error finish_compiling(const String &p_owner);
 
+	static Ref<PackedScene> get_packed_scene(const String &p_path, Error &r_error, const String &p_owner = "");
+	static void clear_unreferenced_packed_scenes();
+
+	static bool is_destructing() {
+		if (singleton == nullptr) {
+			return true;
+		}
+		return singleton->destructing;
+	};
+
 	GDScriptCache();
 	~GDScriptCache();
 };

modules/gdscript/gdscript_compiler.cpp

@@ -141,6 +141,7 @@ GDScriptDataType GDScriptCompiler::_gdtype_from_datatype(const GDScriptParser::D
 					result.script_type_ref = script;
 				}
 				result.script_type = script.ptr();
+				result.native_type = p_datatype.native_type;
 			}
 		} break;
 		case GDScriptParser::DataType::ENUM:
@@ -354,11 +355,22 @@ GDScriptCodeGenerator::Address GDScriptCompiler::_parse_expression(CodeGen &code
 				if (class_node->identifier && class_node->identifier->name == identifier) {
 					res = Ref<GDScript>(main_script);
 				} else {
-					res = ResourceLoader::load(ScriptServer::get_global_class_path(identifier));
-					if (res.is_null()) {
-						_set_error("Can't load global class " + String(identifier) + ", cyclic reference?", p_expression);
-						r_error = ERR_COMPILATION_FAILED;
-						return GDScriptCodeGenerator::Address();
+					String global_class_path = ScriptServer::get_global_class_path(identifier);
+					if (ResourceLoader::get_resource_type(global_class_path) == "GDScript") {
+						Error err = OK;
+						res = GDScriptCache::get_full_script(global_class_path, err);
+						if (err != OK) {
+							_set_error("Can't load global class " + String(identifier), p_expression);
+							r_error = ERR_COMPILATION_FAILED;
+							return GDScriptCodeGenerator::Address();
+						}
+					} else {
+						res = ResourceLoader::load(global_class_path);
+						if (res.is_null()) {
+							_set_error("Can't load global class " + String(identifier) + ", cyclic reference?", p_expression);
+							r_error = ERR_COMPILATION_FAILED;
+							return GDScriptCodeGenerator::Address();
+						}
 					}
 				}
 
@@ -2172,6 +2184,7 @@ Error GDScriptCompiler::_populate_class_members(GDScript *p_script, const GDScri
 
 	parsing_classes.insert(p_script);
 
+	p_script->clearing = true;
 #ifdef TOOLS_ENABLED
 	p_script->doc_functions.clear();
 	p_script->doc_variables.clear();
@@ -2194,10 +2207,24 @@ Error GDScriptCompiler::_populate_class_members(GDScript *p_script, const GDScri
 	p_script->base = Ref<GDScript>();
 	p_script->_base = nullptr;
 	p_script->members.clear();
+
+	// This makes possible to clear script constants and member_functions without heap-use-after-free errors.
+	HashMap<StringName, Variant> constants;
+	for (const KeyValue<StringName, Variant> &E : p_script->constants) {
+		constants.insert(E.key, E.value);
+	}
 	p_script->constants.clear();
+	constants.clear();
+	HashMap<StringName, GDScriptFunction *> member_functions;
 	for (const KeyValue<StringName, GDScriptFunction *> &E : p_script->member_functions) {
+		member_functions.insert(E.key, E.value);
+	}
+	p_script->member_functions.clear();
+	for (const KeyValue<StringName, GDScriptFunction *> &E : member_functions) {
 		memdelete(E.value);
 	}
+	member_functions.clear();
+
 	if (p_script->implicit_initializer) {
 		memdelete(p_script->implicit_initializer);
 	}
@@ -2212,6 +2239,8 @@ Error GDScriptCompiler::_populate_class_members(GDScript *p_script, const GDScri
 	p_script->implicit_initializer = nullptr;
 	p_script->implicit_ready = nullptr;
 
+	p_script->clearing = false;
+
 	p_script->tool = parser->is_tool();
 
 	if (!p_script->name.is_empty()) {
@@ -2454,10 +2483,8 @@ Error GDScriptCompiler::_populate_class_members(GDScript *p_script, const GDScri
 		}
 
 #ifdef TOOLS_ENABLED
-
 		p_script->member_lines[name] = inner_class->start_line;
 #endif
-
 		p_script->constants.insert(name, subclass); //once parsed, goes to the list of constants
 	}
 

modules/gdscript/gdscript_function.cpp

@@ -149,10 +149,17 @@ GDScriptFunction::GDScriptFunction() {
 }
 
 GDScriptFunction::~GDScriptFunction() {
+	get_script()->member_functions.erase(name);
+
 	for (int i = 0; i < lambdas.size(); i++) {
 		memdelete(lambdas[i]);
 	}
 
+	for (int i = 0; i < argument_types.size(); i++) {
+		argument_types.write[i].script_type_ref = Ref<Script>();
+	}
+	return_type.script_type_ref = Ref<Script>();
+
 #ifdef DEBUG_ENABLED
 
 	MutexLock lock(GDScriptLanguage::get_singleton()->mutex);

modules/gdscript/gdscript_function.h

@@ -430,6 +430,7 @@ public:
 	};
 
 private:
+	friend class GDScript;
 	friend class GDScriptCompiler;
 	friend class GDScriptByteCodeGenerator;
 

modules/gdscript/gdscript_parser.cpp

@@ -648,7 +648,13 @@ GDScriptParser::ClassNode *GDScriptParser::parse_class() {
 	if (consume(GDScriptTokenizer::Token::IDENTIFIER, R"(Expected identifier for the class name after "class".)")) {
 		n_class->identifier = parse_identifier();
 		if (n_class->outer) {
-			n_class->fqcn = n_class->outer->fqcn + "::" + n_class->identifier->name;
+			String fqcn = n_class->outer->fqcn;
+			if (fqcn.is_empty()) {
+				fqcn = script_path;
+			}
+			n_class->fqcn = fqcn + "::" + n_class->identifier->name;
+		} else {
+			n_class->fqcn = n_class->identifier->name;
 		}
 	}
 

modules/gdscript/tests/gdscript_test_runner.cpp

@@ -251,7 +251,10 @@ bool GDScriptTestRunner::make_tests_for_dir(const String &p_dir) {
 				return false;
 			}
 		} else {
-			if (next.get_extension().to_lower() == "gd") {
+			if (next.ends_with(".notest.gd")) {
+				next = dir->get_next();
+				continue;
+			} else if (next.get_extension().to_lower() == "gd") {
 #ifndef DEBUG_ENABLED
 				// On release builds, skip tests marked as debug only.
 				Error open_err = OK;
@@ -597,6 +600,9 @@ GDScriptTest::TestResult GDScriptTest::execute_test_code(bool p_is_generating) {
 	}
 
 	enable_stdout();
+
+	GDScriptCache::remove_script(script->get_path());
+
 	return result;
 }
 

modules/gdscript/tests/scripts/analyzer/features/gdscript_to_preload.gd → modules/gdscript/tests/scripts/analyzer/features/gdscript_to_preload.notest.gd

@@ -1,7 +1,4 @@
 const A := 42
 
-func test():
-	pass
-
 func something():
 	return "OK"

modules/gdscript/tests/scripts/analyzer/features/preload_constant_types_are_inferred.gd

@@ -1,4 +1,4 @@
-const Constants = preload("gdscript_to_preload.gd")
+const Constants = preload("gdscript_to_preload.notest.gd")
 
 func test():
 	var a := Constants.A

modules/gdscript/tests/scripts/analyzer/features/preload_cyclic_reference.gd

@@ -0,0 +1,4 @@
+const A = preload("preload_cyclic_reference_a.notest.gd")
+
+func test():
+	A.test_cyclic_reference()

modules/gdscript/tests/scripts/analyzer/features/gdscript_to_preload.out → modules/gdscript/tests/scripts/analyzer/features/preload_cyclic_reference.out

@@ -1 +1,2 @@
 GDTEST_OK
+godot

modules/gdscript/tests/scripts/analyzer/features/preload_cyclic_reference_a.notest.gd

@@ -0,0 +1,12 @@
+const B = preload("preload_cyclic_reference_b.notest.gd")
+
+const WAITING_FOR = "godot"
+
+static func test_cyclic_reference():
+	B.test_cyclic_reference()
+
+static func test_cyclic_reference_2():
+	B.test_cyclic_reference_2()
+
+static func test_cyclic_reference_3():
+	B.test_cyclic_reference_3()

modules/gdscript/tests/scripts/analyzer/features/preload_cyclic_reference_b.notest.gd

@@ -0,0 +1,10 @@
+const A = preload("preload_cyclic_reference_a.notest.gd")
+
+static func test_cyclic_reference():
+	A.test_cyclic_reference_2()
+
+static func test_cyclic_reference_2():
+	A.test_cyclic_reference_3()
+
+static func test_cyclic_reference_3():
+	print(A.WAITING_FOR)

modules/gdscript/tests/scripts/analyzer/features/use_preload_script_as_type.gd

@@ -1,4 +1,4 @@
-const preloaded : GDScript = preload("gdscript_to_preload.gd")
+const preloaded : GDScript = preload("gdscript_to_preload.notest.gd")
 
 func test():
 	var preloaded_instance: preloaded = preloaded.new()

scene/resources/resource_format_text.cpp

@@ -601,9 +601,13 @@ Error ResourceLoaderText::load() {
 		resource_current++;
 
 		int_resources[id] = res; //always assign int resources
-		if (do_assign && cache_mode != ResourceFormatLoader::CACHE_MODE_IGNORE) {
-			res->set_path(path, cache_mode == ResourceFormatLoader::CACHE_MODE_REPLACE);
-			res->set_scene_unique_id(id);
+		if (do_assign) {
+			if (cache_mode == ResourceFormatLoader::CACHE_MODE_IGNORE) {
+				res->set_path(path);
+			} else {
+				res->set_path(path, cache_mode == ResourceFormatLoader::CACHE_MODE_REPLACE);
+				res->set_scene_unique_id(id);
+			}
 		}
 
 		Dictionary missing_resource_properties;

scene/resources/shape_2d.cpp

@@ -124,5 +124,7 @@ Shape2D::Shape2D(const RID &p_rid) {
 }
 
 Shape2D::~Shape2D() {
-	PhysicsServer2D::get_singleton()->free(shape);
+	if (PhysicsServer2D::get_singleton() != nullptr) {
+		PhysicsServer2D::get_singleton()->free(shape);
+	}
 }

scene/resources/shape_3d.cpp

@@ -128,5 +128,7 @@ Shape3D::Shape3D(RID p_shape) :
 		shape(p_shape) {}
 
 Shape3D::~Shape3D() {
-	PhysicsServer3D::get_singleton()->free(shape);
+	if (PhysicsServer3D::get_singleton() != nullptr) {
+		PhysicsServer3D::get_singleton()->free(shape);
+	}
 }