Introduce traits to GDScript

core/config/project_settings.cpp

@@ -1627,6 +1627,7 @@ ProjectSettings::ProjectSettings() {
 
 	GLOBAL_DEF(PropertyInfo(Variant::INT, "debug/settings/profiler/max_functions", PROPERTY_HINT_RANGE, "128,65535,1"), 16384);
 	GLOBAL_DEF_RST(PropertyInfo(Variant::INT, "debug/settings/profiler/max_timestamp_query_elements", PROPERTY_HINT_RANGE, "256,65535,1"), 256);
+	GLOBAL_DEF("debug/gdscript/warnings/show_experimental_trait_warning", true); // @todo: remove experimental tag in 27.1-rc.1
 
 	GLOBAL_DEF(PropertyInfo(Variant::BOOL, "compression/formats/zstd/long_distance_matching"), Compression::zstd_long_distance_matching);
 	GLOBAL_DEF(PropertyInfo(Variant::INT, "compression/formats/zstd/compression_level", PROPERTY_HINT_RANGE, "1,22,1"), Compression::zstd_level);

core/core_bind.cpp

@@ -1586,14 +1586,16 @@ namespace Special {
 ////// ClassDB //////
 
 PackedStringArray ClassDB::get_class_list() const {
-	List<StringName> classes;
-	::ClassDB::get_class_list(&classes);
+	LocalVector<StringName> classes;
+	::ClassDB::get_class_list(classes);
 
 	PackedStringArray ret;
 	ret.resize(classes.size());
+	String *ptrw = ret.ptrw();
 	int idx = 0;
-	for (const StringName &E : classes) {
-		ret.set(idx++, E);
+	for (const StringName &cls : classes) {
+		ptrw[idx] = cls;
+		idx++;
 	}
 
 	return ret;

core/debugger/remote_debugger.cpp

@@ -571,25 +571,25 @@ void RemoteDebugger::debug(bool p_can_continue, bool p_is_error_breakpoint) {
 					input_vals.append(V);
 				}
 
-				List<StringName> native_types;
-				ClassDB::get_class_list(&native_types);
-				for (const StringName &E : native_types) {
-					if (!ClassDB::is_class_exposed(E) || !Engine::get_singleton()->has_singleton(E) || Engine::get_singleton()->is_singleton_editor_only(E)) {
+				LocalVector<StringName> native_types;
+				ClassDB::get_class_list(native_types);
+				for (const StringName &class_name : native_types) {
+					if (!ClassDB::is_class_exposed(class_name) || !Engine::get_singleton()->has_singleton(class_name) || Engine::get_singleton()->is_singleton_editor_only(class_name)) {
 						continue;
 					}
 
-					input_names.append(E);
-					input_vals.append(Engine::get_singleton()->get_singleton_object(E));
+					input_names.append(class_name);
+					input_vals.append(Engine::get_singleton()->get_singleton_object(class_name));
 				}
 
-				List<StringName> user_types;
-				ScriptServer::get_global_class_list(&user_types);
-				for (const StringName &S : user_types) {
-					String scr_path = ScriptServer::get_global_class_path(S);
+				LocalVector<StringName> user_types;
+				ScriptServer::get_global_class_list(user_types);
+				for (const StringName &class_name : user_types) {
+					String scr_path = ScriptServer::get_global_class_path(class_name);
 					Ref<Script> scr = ResourceLoader::load(scr_path, "Script");
-					ERR_CONTINUE_MSG(scr.is_null(), vformat(R"(Could not load the global class %s from resource path: "%s".)", S, scr_path));
+					ERR_CONTINUE_MSG(scr.is_null(), vformat(R"(Could not load the global class %s from resource path: "%s".)", class_name, scr_path));
 
-					input_names.append(S);
+					input_names.append(class_name);
 					input_vals.append(scr);
 				}
 

core/extension/extension_api_dump.cpp

@@ -931,11 +931,9 @@ Dictionary GDExtensionAPIDump::generate_extension_api(bool p_include_docs) {
 		// classes
 		Array classes;
 
-		List<StringName> class_list;
+		LocalVector<StringName> class_list;
 
-		ClassDB::get_class_list(&class_list);
-
-		class_list.sort_custom<StringName::AlphCompare>();
+		ClassDB::get_class_list(class_list);
 
 		for (const StringName &class_name : class_list) {
 			if (!ClassDB::is_class_exposed(class_name)) {

core/io/resource_loader.cpp

@@ -1492,8 +1492,8 @@ void ResourceLoader::set_create_missing_resources_if_class_unavailable(bool p_en
 void ResourceLoader::add_custom_loaders() {
 	String custom_loader_base_class = ResourceFormatLoader::get_class_static();
 
-	List<StringName> global_classes;
-	ScriptServer::get_global_class_list(&global_classes);
+	LocalVector<StringName> global_classes;
+	ScriptServer::get_global_class_list(global_classes);
 
 	for (const StringName &class_name : global_classes) {
 		StringName base_class = ScriptServer::get_global_class_native_base(class_name);

core/io/resource_saver.cpp

@@ -261,8 +261,8 @@ bool ResourceSaver::add_custom_resource_format_saver(const String &script_path)
 void ResourceSaver::add_custom_savers() {
 	String custom_saver_base_class = ResourceFormatSaver::get_class_static();
 
-	List<StringName> global_classes;
-	ScriptServer::get_global_class_list(&global_classes);
+	LocalVector<StringName> global_classes;
+	ScriptServer::get_global_class_list(global_classes);
 
 	for (const StringName &class_name : global_classes) {
 		StringName base_class = ScriptServer::get_global_class_native_base(class_name);

core/object/class_db.cpp

@@ -41,6 +41,7 @@
 #include "core/config/engine.h"
 #include "core/io/resource_loader.h"
 #include "core/object/script_language.h"
+#include "core/templates/sort_array.h"
 #include "core/version.h"
 
 #ifdef DEBUG_ENABLED
@@ -248,28 +249,46 @@ bool ClassDB::is_parent_class(const StringName &p_class, const StringName &p_inh
 	return _is_parent_class(p_class, p_inherits);
 }
 
-void ClassDB::get_class_list(List<StringName> *p_classes) {
+// This function only sorts items added by this function.
+// If `p_classes` is not empty before calling and a global sort is needed, caller must handle that separately.
+void ClassDB::get_class_list(LocalVector<StringName> &p_classes) {
 	Locker::Lock lock(Locker::STATE_READ);
 
-	for (const KeyValue<StringName, ClassInfo> &E : classes) {
-		p_classes->push_back(E.key);
+	if (classes.is_empty()) {
+		return;
 	}
 
-	p_classes->sort_custom<StringName::AlphCompare>();
+	p_classes.reserve(p_classes.size() + classes.size());
+	for (const KeyValue<StringName, ClassInfo> &cls : classes) {
+		p_classes.push_back(cls.key);
+	}
+
+	SortArray<StringName, StringName::AlphCompare> sorter;
+	sorter.sort(&p_classes[p_classes.size() - classes.size()], classes.size());
 }
 
 #ifdef TOOLS_ENABLED
-void ClassDB::get_extensions_class_list(List<StringName> *p_classes) {
+// This function only sorts items added by this function.
+// If `p_classes` is not empty before calling and a global sort is needed, caller must handle that separately.
+void ClassDB::get_extensions_class_list(LocalVector<StringName> &p_classes) {
 	Locker::Lock lock(Locker::STATE_READ);
 
+	uint32_t original_size = p_classes.size();
+
 	for (const KeyValue<StringName, ClassInfo> &E : classes) {
 		if (E.value.api != API_EXTENSION && E.value.api != API_EDITOR_EXTENSION) {
 			continue;
 		}
-		p_classes->push_back(E.key);
+		p_classes.push_back(E.key);
 	}
 
-	p_classes->sort_custom<StringName::AlphCompare>();
+	// Nothing appended.
+	if (p_classes.size() == original_size) {
+		return;
+	}
+
+	SortArray<StringName, StringName::AlphCompare> sorter;
+	sorter.sort(&p_classes[original_size], p_classes.size() - original_size);
 }
 
 void ClassDB::get_extension_class_list(const Ref<GDExtension> &p_extension, List<StringName> *p_classes) {

core/object/class_db.h

@@ -319,9 +319,9 @@ class ClassDB {
 		T::register_custom_data_to_otdb();
 	}
 
-	static void get_class_list(List<StringName> *p_classes);
+	static void get_class_list(LocalVector<StringName> &p_classes);
 #ifdef TOOLS_ENABLED
-	static void get_extensions_class_list(List<StringName> *p_classes);
+	static void get_extensions_class_list(LocalVector<StringName> &p_classes);
 	static void get_extension_class_list(const Ref<GDExtension> &p_extension, List<StringName> *p_classes);
 	static ObjectGDExtension *get_placeholder_extension(const StringName &p_class);
 #endif

core/object/script_language.cpp

@@ -43,6 +43,7 @@
 #include "core/debugger/engine_debugger.h"
 #include "core/debugger/script_debugger.h"
 #include "core/io/resource_loader.h"
+#include "core/templates/sort_array.h"
 
 ScriptLanguage *ScriptServer::_languages[MAX_LANGUAGES];
 int ScriptServer::_language_count = 0;
@@ -515,15 +516,18 @@ bool ScriptServer::is_global_class_tool(const String &p_class) {
 	return global_classes[p_class].is_tool;
 }
 
-void ScriptServer::get_global_class_list(List<StringName> *r_global_classes) {
-	List<StringName> classes;
-	for (const KeyValue<StringName, GlobalScriptClass> &E : global_classes) {
-		classes.push_back(E.key);
+// This function only sorts items added by this function.
+// If `r_global_classes` is not empty before calling and a global sort is needed, caller must handle that separately.
+void ScriptServer::get_global_class_list(LocalVector<StringName> &r_global_classes) {
+	if (global_classes.is_empty()) {
+		return;
 	}
-	classes.sort_custom<StringName::AlphCompare>();
-	for (const StringName &E : classes) {
-		r_global_classes->push_back(E);
+	r_global_classes.reserve(r_global_classes.size() + global_classes.size());
+	for (const KeyValue<StringName, GlobalScriptClass> &global_class : global_classes) {
+		r_global_classes.push_back(global_class.key);
 	}
+	SortArray<StringName, StringName::AlphCompare> sorter;
+	sorter.sort(&r_global_classes[r_global_classes.size() - global_classes.size()], global_classes.size());
 }
 
 void ScriptServer::save_global_classes() {
@@ -538,17 +542,17 @@ void ScriptServer::save_global_classes() {
 		class_icons[d["name"]] = d["icon"];
 	}
 
-	List<StringName> gc;
-	get_global_class_list(&gc);
+	LocalVector<StringName> gc;
+	get_global_class_list(gc);
 	Array gcarr;
-	for (const StringName &E : gc) {
-		const GlobalScriptClass &global_class = global_classes[E];
+	for (const StringName &class_name : gc) {
+		const GlobalScriptClass &global_class = global_classes[class_name];
 		Dictionary d;
-		d["class"] = E;
+		d["class"] = class_name;
 		d["language"] = global_class.language;
 		d["path"] = global_class.path;
 		d["base"] = global_class.base;
-		d["icon"] = class_icons.get(E, "");
+		d["icon"] = class_icons.get(class_name, "");
 		d["is_abstract"] = global_class.is_abstract;
 		d["is_tool"] = global_class.is_tool;
 		gcarr.push_back(d);

core/object/script_language.h

@@ -106,7 +106,7 @@ class ScriptServer {
 	static StringName get_global_class_native_base(const String &p_class);
 	static bool is_global_class_abstract(const String &p_class);
 	static bool is_global_class_tool(const String &p_class);
-	static void get_global_class_list(List<StringName> *r_global_classes);
+	static void get_global_class_list(LocalVector<StringName> &r_global_classes);
 	static void get_inheriters_list(const StringName &p_base_type, List<StringName> *r_classes);
 	static void save_global_classes();
 

doc/classes/ProjectSettings.xml

@@ -556,6 +556,9 @@
 		<member name="debug/gdscript/warnings/exclude_addons" type="bool" setter="" getter="" default="true">
 			If [code]true[/code], scripts in the [code]res://addons[/code] folder will not generate warnings.
 		</member>
+		<member name="debug/gdscript/warnings/experimental_trait" type="int" setter="" getter="" default="1">
+			When set to [code]warn[/code] or [code]error[/code], produces a warning or an error respectively when using traits, as they are still experimental and may be subject to changes in future releases.
+		</member>
 		<member name="debug/gdscript/warnings/get_node_default_without_onready" type="int" setter="" getter="" default="2">
 			When set to [code]warn[/code] or [code]error[/code], produces a warning or an error respectively when [method Node.get_node] (or the shorthand [code]$[/code]) is used as default value of a class variable without the [code]@onready[/code] annotation.
 		</member>
@@ -611,6 +614,9 @@
 		<member name="debug/gdscript/warnings/shadowed_variable_base_class" type="int" setter="" getter="" default="1">
 			When set to [code]warn[/code] or [code]error[/code], produces a warning or an error respectively when a local variable or local constant shadows a member declared in a base class.
 		</member>
+		<member name="debug/gdscript/warnings/show_experimental_trait_warning" type="bool" setter="" getter="" default="true">
+			When set to [code]true[/code], the editor will generate warnings when using traits, as they are still experimental and may be subject to changes in future releases.
+		</member>
 		<member name="debug/gdscript/warnings/standalone_expression" type="int" setter="" getter="" default="1">
 			When set to [code]warn[/code] or [code]error[/code], produces a warning or an error respectively when calling an expression that may have no effect on the surrounding code, such as writing [code]2 + 2[/code] as a statement.
 		</member>
@@ -663,6 +669,9 @@
 		<member name="debug/gdscript/warnings/unused_signal" type="int" setter="" getter="" default="1">
 			When set to [code]warn[/code] or [code]error[/code], produces a warning or an error respectively when a signal is declared but never explicitly used in the class.
 		</member>
+		<member name="debug/gdscript/warnings/unused_static_overriding_trait" type="int" setter="" getter="" default="1">
+			When set to [code]warn[/code] or [code]error[/code], produces a warning or an error respectively when an overridden static member from a trait is not declared with the [code]static[/code] keyword.
+		</member>
 		<member name="debug/gdscript/warnings/unused_variable" type="int" setter="" getter="" default="1">
 			When set to [code]warn[/code] or [code]error[/code], produces a warning or an error respectively when a local variable is unused.
 		</member>

editor/doc/doc_tools.cpp

@@ -413,23 +413,23 @@ void DocTools::generate(BitField<GenerateFlags> p_flags) {
 
 	// Add ClassDB-exposed classes.
 	{
-		List<StringName> classes;
+		LocalVector<StringName> classes;
 		if (p_flags.has_flag(GENERATE_FLAG_EXTENSION_CLASSES_ONLY)) {
-			ClassDB::get_extensions_class_list(&classes);
+			ClassDB::get_extensions_class_list(classes);
 		} else {
-			ClassDB::get_class_list(&classes);
+			ClassDB::get_class_list(classes);
 			// Move ProjectSettings, so that other classes can register properties there.
-			classes.move_to_back(classes.find("ProjectSettings"));
+			classes.erase("ProjectSettings");
+			classes.push_back("ProjectSettings");
 		}
 
 		bool skip_setter_getter_methods = true;
 
 		// Populate documentation data for each exposed class.
-		while (classes.size()) {
-			const String &name = classes.front()->get();
+		for (uint32_t classes_idx = 0; classes_idx < classes.size(); classes_idx++) {
+			const String &name = classes[classes_idx];
 			if (!ClassDB::is_class_exposed(name)) {
 				print_verbose(vformat("Class '%s' is not exposed, skipping.", name));
-				classes.pop_front();
 				continue;
 			}
 
@@ -734,8 +734,6 @@ void DocTools::generate(BitField<GenerateFlags> p_flags) {
 
 				c.theme_properties.sort();
 			}
-
-			classes.pop_front();
 		}
 	}
 

editor/editor_data.cpp

@@ -1053,8 +1053,8 @@ void EditorData::script_class_set_name(const String &p_path, const StringName &p
 }
 
 void EditorData::script_class_save_global_classes() {
-	List<StringName> global_classes;
-	ScriptServer::get_global_class_list(&global_classes);
+	LocalVector<StringName> global_classes;
+	ScriptServer::get_global_class_list(global_classes);
 	Array array_classes;
 	for (const StringName &class_name : global_classes) {
 		Dictionary d;

editor/file_system/editor_file_system.cpp

@@ -1657,9 +1657,9 @@ void EditorFileSystem::_thread_func_sources(void *_userdata) {
 }
 
 bool EditorFileSystem::_remove_invalid_global_class_names(const HashSet<String> &p_existing_class_names) {
-	List<StringName> global_classes;
+	LocalVector<StringName> global_classes;
 	bool must_save = false;
-	ScriptServer::get_global_class_list(&global_classes);
+	ScriptServer::get_global_class_list(global_classes);
 	for (const StringName &class_name : global_classes) {
 		if (!p_existing_class_names.has(class_name)) {
 			ScriptServer::remove_global_class(class_name);

editor/gui/create_dialog.cpp

@@ -89,9 +89,9 @@ void CreateDialog::for_inherit() {
 }
 
 void CreateDialog::_fill_type_list() {
-	List<StringName> complete_type_list;
-	ClassDB::get_class_list(&complete_type_list);
-	ScriptServer::get_global_class_list(&complete_type_list);
+	LocalVector<StringName> complete_type_list;
+	ClassDB::get_class_list(complete_type_list);
+	ScriptServer::get_global_class_list(complete_type_list);
 
 	EditorData &ed = EditorNode::get_editor_data();
 	HashMap<String, DocData::ClassDoc> &class_docs_list = EditorHelp::get_doc_data()->class_list;

editor/project_upgrade/project_converter_3_to_4.cpp

@@ -1193,8 +1193,8 @@ bool ProjectConverter3To4::test_array_names() {
 		//	}
 		//}
 
-		List<StringName> classes_list;
-		ClassDB::get_class_list(&classes_list);
+		LocalVector<StringName> classes_list;
+		ClassDB::get_class_list(classes_list);
 		for (StringName &name_of_class : classes_list) {
 			List<MethodInfo> method_list;
 			ClassDB::get_method_list(name_of_class, &method_list, true);

editor/script/script_editor_plugin.cpp

@@ -133,18 +133,18 @@ void EditorStandardSyntaxHighlighter::_update_cache() {
 
 	/* Engine types. */
 	const Color type_color = EDITOR_GET("text_editor/theme/highlighting/engine_type_color");
-	List<StringName> types;
-	ClassDB::get_class_list(&types);
-	for (const StringName &E : types) {
-		highlighter->add_keyword_color(E, type_color);
+	LocalVector<StringName> types;
+	ClassDB::get_class_list(types);
+	for (const StringName &type : types) {
+		highlighter->add_keyword_color(type, type_color);
 	}
 
 	/* User types. */
 	const Color usertype_color = EDITOR_GET("text_editor/theme/highlighting/user_type_color");
-	List<StringName> global_classes;
-	ScriptServer::get_global_class_list(&global_classes);
-	for (const StringName &E : global_classes) {
-		highlighter->add_keyword_color(E, usertype_color);
+	LocalVector<StringName> global_classes;
+	ScriptServer::get_global_class_list(global_classes);
+	for (const StringName &class_name : global_classes) {
+		highlighter->add_keyword_color(class_name, usertype_color);
 	}
 
 	/* Autoloads. */