[Core] Improve error messages with `vformat`

core/config/project_settings.cpp

@@ -214,36 +214,36 @@ String ProjectSettings::localize_path(const String &p_path) const {
 }
 
 void ProjectSettings::set_initial_value(const String &p_name, const Variant &p_value) {
-	ERR_FAIL_COND_MSG(!props.has(p_name), "Request for nonexistent project setting: " + p_name + ".");
+	ERR_FAIL_COND_MSG(!props.has(p_name), vformat("Request for nonexistent project setting: '%s'.", p_name));
 
 	// Duplicate so that if value is array or dictionary, changing the setting will not change the stored initial value.
 	props[p_name].initial = p_value.duplicate();
 }
 
 void ProjectSettings::set_restart_if_changed(const String &p_name, bool p_restart) {
-	ERR_FAIL_COND_MSG(!props.has(p_name), "Request for nonexistent project setting: " + p_name + ".");
+	ERR_FAIL_COND_MSG(!props.has(p_name), vformat("Request for nonexistent project setting: '%s'.", p_name));
 	props[p_name].restart_if_changed = p_restart;
 }
 
 void ProjectSettings::set_as_basic(const String &p_name, bool p_basic) {
-	ERR_FAIL_COND_MSG(!props.has(p_name), "Request for nonexistent project setting: " + p_name + ".");
+	ERR_FAIL_COND_MSG(!props.has(p_name), vformat("Request for nonexistent project setting: '%s'.", p_name));
 	props[p_name].basic = p_basic;
 }
 
 void ProjectSettings::set_as_internal(const String &p_name, bool p_internal) {
-	ERR_FAIL_COND_MSG(!props.has(p_name), "Request for nonexistent project setting: " + p_name + ".");
+	ERR_FAIL_COND_MSG(!props.has(p_name), vformat("Request for nonexistent project setting: '%s'.", p_name));
 	props[p_name].internal = p_internal;
 }
 
 void ProjectSettings::set_ignore_value_in_docs(const String &p_name, bool p_ignore) {
-	ERR_FAIL_COND_MSG(!props.has(p_name), "Request for nonexistent project setting: " + p_name + ".");
+	ERR_FAIL_COND_MSG(!props.has(p_name), vformat("Request for nonexistent project setting: '%s'.", p_name));
 #ifdef DEBUG_METHODS_ENABLED
 	props[p_name].ignore_value_in_docs = p_ignore;
 #endif
 }
 
 bool ProjectSettings::get_ignore_value_in_docs(const String &p_name) const {
-	ERR_FAIL_COND_V_MSG(!props.has(p_name), false, "Request for nonexistent project setting: " + p_name + ".");
+	ERR_FAIL_COND_V_MSG(!props.has(p_name), false, vformat("Request for nonexistent project setting: '%s'.", p_name));
 #ifdef DEBUG_METHODS_ENABLED
 	return props[p_name].ignore_value_in_docs;
 #else
@@ -371,7 +371,7 @@ Variant ProjectSettings::get_setting_with_override(const StringName &p_name) con
 	}
 
 	if (!props.has(name)) {
-		WARN_PRINT("Property not found: " + String(name));
+		WARN_PRINT(vformat("Property not found: '%s'.", String(name)));
 		return Variant();
 	}
 	return props[name].variant;
@@ -565,7 +565,7 @@ Error ProjectSettings::_setup(const String &p_path, const String &p_main_pack, b
 
 	if (!p_main_pack.is_empty()) {
 		bool ok = _load_resource_pack(p_main_pack);
-		ERR_FAIL_COND_V_MSG(!ok, ERR_CANT_OPEN, "Cannot open resource pack '" + p_main_pack + "'.");
+		ERR_FAIL_COND_V_MSG(!ok, ERR_CANT_OPEN, vformat("Cannot open resource pack '%s'.", p_main_pack));
 
 		Error err = _load_settings_text_or_binary("res://project.godot", "res://project.binary");
 		if (err == OK && !p_ignore_override) {
@@ -644,7 +644,7 @@ Error ProjectSettings::_setup(const String &p_path, const String &p_main_pack, b
 	// or, if requested (`p_upwards`) in parent directories.
 
 	Ref<DirAccess> d = DirAccess::create(DirAccess::ACCESS_FILESYSTEM);
-	ERR_FAIL_COND_V_MSG(d.is_null(), ERR_CANT_CREATE, "Cannot create DirAccess for path '" + p_path + "'.");
+	ERR_FAIL_COND_V_MSG(d.is_null(), ERR_CANT_CREATE, vformat("Cannot create DirAccess for path '%s'.", p_path));
 	d->change_dir(p_path);
 
 	String current_dir = d->get_current_dir();
@@ -748,7 +748,7 @@ Error ProjectSettings::_load_settings_binary(const String &p_path) {
 		f->get_buffer(d.ptrw(), vlen);
 		Variant value;
 		err = decode_variant(value, d.ptr(), d.size(), nullptr, true);
-		ERR_CONTINUE_MSG(err != OK, "Error decoding property: " + key + ".");
+		ERR_CONTINUE_MSG(err != OK, vformat("Error decoding property: '%s'.", key));
 		set(key, value);
 	}
 
@@ -790,7 +790,7 @@ Error ProjectSettings::_load_settings_text(const String &p_path) {
 			last_save_time = FileAccess::get_modified_time(get_resource_path().path_join("project.godot"));
 			return OK;
 		}
-		ERR_FAIL_COND_V_MSG(err != OK, err, "Error parsing " + p_path + " at line " + itos(lines) + ": " + error_text + " File might be corrupted.");
+		ERR_FAIL_COND_V_MSG(err != OK, err, vformat("Error parsing '%s' at line %d: %s File might be corrupted.", p_path, lines, error_text));
 
 		if (!assign.is_empty()) {
 			if (section.is_empty() && assign == "config_version") {
@@ -816,7 +816,7 @@ Error ProjectSettings::_load_settings_text_or_binary(const String &p_text_path,
 		return OK;
 	} else if (err != ERR_FILE_NOT_FOUND) {
 		// If the file exists but can't be loaded, we want to know it.
-		ERR_PRINT("Couldn't load file '" + p_bin_path + "', error code " + itos(err) + ".");
+		ERR_PRINT(vformat("Couldn't load file '%s', error code %d.", p_bin_path, err));
 	}
 
 	// Fallback to text-based project.godot file if binary was not found.
@@ -824,7 +824,7 @@ Error ProjectSettings::_load_settings_text_or_binary(const String &p_text_path,
 	if (err == OK) {
 		return OK;
 	} else if (err != ERR_FILE_NOT_FOUND) {
-		ERR_PRINT("Couldn't load file '" + p_text_path + "', error code " + itos(err) + ".");
+		ERR_PRINT(vformat("Couldn't load file '%s', error code %d.", p_text_path, err));
 	}
 
 	return err;
@@ -838,17 +838,17 @@ Error ProjectSettings::load_custom(const String &p_path) {
 }
 
 int ProjectSettings::get_order(const String &p_name) const {
-	ERR_FAIL_COND_V_MSG(!props.has(p_name), -1, "Request for nonexistent project setting: " + p_name + ".");
+	ERR_FAIL_COND_V_MSG(!props.has(p_name), -1, vformat("Request for nonexistent project setting: '%s'.", p_name));
 	return props[p_name].order;
 }
 
 void ProjectSettings::set_order(const String &p_name, int p_order) {
-	ERR_FAIL_COND_MSG(!props.has(p_name), "Request for nonexistent project setting: " + p_name + ".");
+	ERR_FAIL_COND_MSG(!props.has(p_name), vformat("Request for nonexistent project setting: '%s'.", p_name));
 	props[p_name].order = p_order;
 }
 
 void ProjectSettings::set_builtin_order(const String &p_name) {
-	ERR_FAIL_COND_MSG(!props.has(p_name), "Request for nonexistent project setting: " + p_name + ".");
+	ERR_FAIL_COND_MSG(!props.has(p_name), vformat("Request for nonexistent project setting: '%s'.", p_name));
 	if (props[p_name].order >= NO_BUILTIN_ORDER_BASE) {
 		props[p_name].order = last_builtin_order++;
 	}
@@ -856,12 +856,12 @@ void ProjectSettings::set_builtin_order(const String &p_name) {
 
 bool ProjectSettings::is_builtin_setting(const String &p_name) const {
 	// Return true because a false negative is worse than a false positive.
-	ERR_FAIL_COND_V_MSG(!props.has(p_name), true, "Request for nonexistent project setting: " + p_name + ".");
+	ERR_FAIL_COND_V_MSG(!props.has(p_name), true, vformat("Request for nonexistent project setting: '%s'.", p_name));
 	return props[p_name].order < NO_BUILTIN_ORDER_BASE;
 }
 
 void ProjectSettings::clear(const String &p_name) {
-	ERR_FAIL_COND_MSG(!props.has(p_name), "Request for nonexistent project setting: " + p_name + ".");
+	ERR_FAIL_COND_MSG(!props.has(p_name), vformat("Request for nonexistent project setting: '%s'.", p_name));
 	props.erase(p_name);
 }
 
@@ -876,7 +876,7 @@ Error ProjectSettings::save() {
 Error ProjectSettings::_save_settings_binary(const String &p_file, const RBMap<String, List<String>> &p_props, const CustomMap &p_custom, const String &p_custom_features) {
 	Error err;
 	Ref<FileAccess> file = FileAccess::open(p_file, FileAccess::WRITE, &err);
-	ERR_FAIL_COND_V_MSG(err != OK, err, "Couldn't save project.binary at " + p_file + ".");
+	ERR_FAIL_COND_V_MSG(err != OK, err, vformat("Couldn't save project.binary at '%s'.", p_file));
 
 	uint8_t hdr[4] = { 'E', 'C', 'F', 'G' };
 	file->store_buffer(hdr, 4);
@@ -946,7 +946,7 @@ Error ProjectSettings::_save_settings_text(const String &p_file, const RBMap<Str
 	Error err;
 	Ref<FileAccess> file = FileAccess::open(p_file, FileAccess::WRITE, &err);
 
-	ERR_FAIL_COND_V_MSG(err != OK, err, "Couldn't save project.godot - " + p_file + ".");
+	ERR_FAIL_COND_V_MSG(err != OK, err, vformat("Couldn't save project.godot - %s.", p_file));
 
 	file->store_line("; Engine configuration file.");
 	file->store_line("; It's best edited using the editor UI and not directly,");
@@ -1119,7 +1119,7 @@ Error ProjectSettings::save_custom(const String &p_path, const CustomMap &p_cust
 	} else if (p_path.ends_with(".binary")) {
 		return _save_settings_binary(p_path, save_props, p_custom, save_features);
 	} else {
-		ERR_FAIL_V_MSG(ERR_FILE_UNRECOGNIZED, "Unknown config file format: " + p_path);
+		ERR_FAIL_V_MSG(ERR_FILE_UNRECOGNIZED, vformat("Unknown config file format: '%s'.", p_path));
 	}
 }
 

core/core_bind.cpp

@@ -75,7 +75,7 @@ Ref<Resource> ResourceLoader::load(const String &p_path, const String &p_type_hi
 	Error err = OK;
 	Ref<Resource> ret = ::ResourceLoader::load(p_path, p_type_hint, ResourceFormatLoader::CacheMode(p_cache_mode), &err);
 
-	ERR_FAIL_COND_V_MSG(err != OK, ret, "Error loading resource: '" + p_path + "'.");
+	ERR_FAIL_COND_V_MSG(err != OK, ret, vformat("Error loading resource: '%s'.", p_path));
 	return ret;
 }
 
@@ -1315,7 +1315,7 @@ void Thread::_start_func(void *ud) {
 	}
 
 	if (ce.error != Callable::CallError::CALL_OK) {
-		ERR_FAIL_MSG("Could not call function '" + func_name + "' to start thread " + t->get_id() + ": " + Variant::get_callable_error_text(t->target_callable, nullptr, 0, ce) + ".");
+		ERR_FAIL_MSG(vformat("Could not call function '%s' to start thread %d: %s.", func_name, t->get_id(), Variant::get_callable_error_text(t->target_callable, nullptr, 0, ce)));
 	}
 }
 
@@ -1814,8 +1814,8 @@ Object *Engine::get_singleton_object(const StringName &p_name) const {
 }
 
 void Engine::register_singleton(const StringName &p_name, Object *p_object) {
-	ERR_FAIL_COND_MSG(has_singleton(p_name), "Singleton already registered: " + String(p_name));
-	ERR_FAIL_COND_MSG(!String(p_name).is_valid_ascii_identifier(), "Singleton name is not a valid identifier: " + p_name);
+	ERR_FAIL_COND_MSG(has_singleton(p_name), vformat("Singleton already registered: '%s'.", String(p_name)));
+	ERR_FAIL_COND_MSG(!String(p_name).is_valid_ascii_identifier(), vformat("Singleton name is not a valid identifier: '%s'.", p_name));
 	::Engine::Singleton s;
 	s.class_name = p_name;
 	s.name = p_name;
@@ -1825,8 +1825,8 @@ void Engine::register_singleton(const StringName &p_name, Object *p_object) {
 }
 
 void Engine::unregister_singleton(const StringName &p_name) {
-	ERR_FAIL_COND_MSG(!has_singleton(p_name), "Attempt to remove unregistered singleton: " + String(p_name));
-	ERR_FAIL_COND_MSG(!::Engine::get_singleton()->is_singleton_user_created(p_name), "Attempt to remove non-user created singleton: " + String(p_name));
+	ERR_FAIL_COND_MSG(!has_singleton(p_name), vformat("Attempt to remove unregistered singleton: '%s'.", String(p_name)));
+	ERR_FAIL_COND_MSG(!::Engine::get_singleton()->is_singleton_user_created(p_name), vformat("Attempt to remove non-user created singleton: '%s'.", String(p_name)));
 	::Engine::get_singleton()->remove_singleton(p_name);
 }
 
@@ -1970,14 +1970,14 @@ bool EngineDebugger::is_active() {
 void EngineDebugger::register_profiler(const StringName &p_name, Ref<EngineProfiler> p_profiler) {
 	ERR_FAIL_COND(p_profiler.is_null());
 	ERR_FAIL_COND_MSG(p_profiler->is_bound(), "Profiler already registered.");
-	ERR_FAIL_COND_MSG(profilers.has(p_name) || has_profiler(p_name), "Profiler name already in use: " + p_name);
+	ERR_FAIL_COND_MSG(profilers.has(p_name) || has_profiler(p_name), vformat("Profiler name already in use: '%s'.", p_name));
 	Error err = p_profiler->bind(p_name);
-	ERR_FAIL_COND_MSG(err != OK, "Profiler failed to register with error: " + itos(err));
+	ERR_FAIL_COND_MSG(err != OK, vformat("Profiler failed to register with error: %d.", err));
 	profilers.insert(p_name, p_profiler);
 }
 
 void EngineDebugger::unregister_profiler(const StringName &p_name) {
-	ERR_FAIL_COND_MSG(!profilers.has(p_name), "Profiler not registered: " + p_name);
+	ERR_FAIL_COND_MSG(!profilers.has(p_name), vformat("Profiler not registered: '%s'.", p_name));
 	profilers[p_name]->unbind();
 	profilers.erase(p_name);
 }
@@ -2001,7 +2001,7 @@ void EngineDebugger::profiler_enable(const StringName &p_name, bool p_enabled, c
 }
 
 void EngineDebugger::register_message_capture(const StringName &p_name, const Callable &p_callable) {
-	ERR_FAIL_COND_MSG(captures.has(p_name) || has_capture(p_name), "Capture already registered: " + p_name);
+	ERR_FAIL_COND_MSG(captures.has(p_name) || has_capture(p_name), vformat("Capture already registered: '%s'.", p_name));
 	captures.insert(p_name, p_callable);
 	Callable &c = captures[p_name];
 	::EngineDebugger::Capture capture(&c, &EngineDebugger::call_capture);
@@ -2009,7 +2009,7 @@ void EngineDebugger::register_message_capture(const StringName &p_name, const Ca
 }
 
 void EngineDebugger::unregister_message_capture(const StringName &p_name) {
-	ERR_FAIL_COND_MSG(!captures.has(p_name), "Capture not registered: " + p_name);
+	ERR_FAIL_COND_MSG(!captures.has(p_name), vformat("Capture not registered: '%s'.", p_name));
 	::EngineDebugger::unregister_message_capture(p_name);
 	captures.erase(p_name);
 }
@@ -2043,8 +2043,8 @@ Error EngineDebugger::call_capture(void *p_user, const String &p_cmd, const Arra
 	Variant retval;
 	Callable::CallError err;
 	capture.callp(args, 2, retval, err);
-	ERR_FAIL_COND_V_MSG(err.error != Callable::CallError::CALL_OK, FAILED, "Error calling 'capture' to callable: " + Variant::get_callable_error_text(capture, args, 2, err));
-	ERR_FAIL_COND_V_MSG(retval.get_type() != Variant::BOOL, FAILED, "Error calling 'capture' to callable: " + String(capture) + ". Return type is not bool.");
+	ERR_FAIL_COND_V_MSG(err.error != Callable::CallError::CALL_OK, FAILED, vformat("Error calling 'capture' to callable: %s.", Variant::get_callable_error_text(capture, args, 2, err)));
+	ERR_FAIL_COND_V_MSG(retval.get_type() != Variant::BOOL, FAILED, vformat("Error calling 'capture' to callable: '%s'. Return type is not bool.", String(capture)));
 	r_captured = retval;
 	return OK;
 }

core/crypto/crypto.cpp

@@ -240,7 +240,7 @@ Error ResourceFormatSaverCrypto::save(const Ref<Resource> &p_resource, const Str
 	} else {
 		ERR_FAIL_V(ERR_INVALID_PARAMETER);
 	}
-	ERR_FAIL_COND_V_MSG(err != OK, err, "Cannot save Crypto resource to file '" + p_path + "'.");
+	ERR_FAIL_COND_V_MSG(err != OK, err, vformat("Cannot save Crypto resource to file '%s'.", p_path));
 	return OK;
 }
 

core/crypto/crypto_core.cpp

@@ -70,7 +70,7 @@ int CryptoCore::RandomGenerator::_entropy_poll(void *p_data, unsigned char *r_bu
 Error CryptoCore::RandomGenerator::init() {
 	int ret = mbedtls_ctr_drbg_seed((mbedtls_ctr_drbg_context *)ctx, mbedtls_entropy_func, (mbedtls_entropy_context *)entropy, nullptr, 0);
 	if (ret) {
-		ERR_FAIL_COND_V_MSG(ret, FAILED, " failed\n  ! mbedtls_ctr_drbg_seed returned an error" + itos(ret));
+		ERR_FAIL_COND_V_MSG(ret, FAILED, vformat(" failed\n  ! mbedtls_ctr_drbg_seed returned an error %d.", ret));
 	}
 	return OK;
 }
@@ -78,7 +78,7 @@ Error CryptoCore::RandomGenerator::init() {
 Error CryptoCore::RandomGenerator::get_random_bytes(uint8_t *r_buffer, size_t p_bytes) {
 	ERR_FAIL_NULL_V(ctx, ERR_UNCONFIGURED);
 	int ret = mbedtls_ctr_drbg_random((mbedtls_ctr_drbg_context *)ctx, r_buffer, p_bytes);
-	ERR_FAIL_COND_V_MSG(ret, FAILED, " failed\n  ! mbedtls_ctr_drbg_seed returned an error" + itos(ret));
+	ERR_FAIL_COND_V_MSG(ret, FAILED, vformat(" failed\n  ! mbedtls_ctr_drbg_seed returned an error %d.", ret));
 	return OK;
 }
 

core/debugger/engine_debugger.cpp

@@ -46,12 +46,12 @@ HashMap<String, EngineDebugger::CreatePeerFunc> EngineDebugger::protocols;
 void (*EngineDebugger::allow_focus_steal_fn)();
 
 void EngineDebugger::register_profiler(const StringName &p_name, const Profiler &p_func) {
-	ERR_FAIL_COND_MSG(profilers.has(p_name), "Profiler already registered: " + p_name);
+	ERR_FAIL_COND_MSG(profilers.has(p_name), vformat("Profiler already registered: '%s'.", p_name));
 	profilers.insert(p_name, p_func);
 }
 
 void EngineDebugger::unregister_profiler(const StringName &p_name) {
-	ERR_FAIL_COND_MSG(!profilers.has(p_name), "Profiler not registered: " + p_name);
+	ERR_FAIL_COND_MSG(!profilers.has(p_name), vformat("Profiler not registered: '%s'.", p_name));
 	Profiler &p = profilers[p_name];
 	if (p.active && p.toggle) {
 		p.toggle(p.data, false, Array());
@@ -61,22 +61,22 @@ void EngineDebugger::unregister_profiler(const StringName &p_name) {
 }
 
 void EngineDebugger::register_message_capture(const StringName &p_name, Capture p_func) {
-	ERR_FAIL_COND_MSG(captures.has(p_name), "Capture already registered: " + p_name);
+	ERR_FAIL_COND_MSG(captures.has(p_name), vformat("Capture already registered: '%s'.", p_name));
 	captures.insert(p_name, p_func);
 }
 
 void EngineDebugger::unregister_message_capture(const StringName &p_name) {
-	ERR_FAIL_COND_MSG(!captures.has(p_name), "Capture not registered: " + p_name);
+	ERR_FAIL_COND_MSG(!captures.has(p_name), vformat("Capture not registered: '%s'.", p_name));
 	captures.erase(p_name);
 }
 
 void EngineDebugger::register_uri_handler(const String &p_protocol, CreatePeerFunc p_func) {
-	ERR_FAIL_COND_MSG(protocols.has(p_protocol), "Protocol handler already registered: " + p_protocol);
+	ERR_FAIL_COND_MSG(protocols.has(p_protocol), vformat("Protocol handler already registered: '%s'.", p_protocol));
 	protocols.insert(p_protocol, p_func);
 }
 
 void EngineDebugger::profiler_enable(const StringName &p_name, bool p_enabled, const Array &p_opts) {
-	ERR_FAIL_COND_MSG(!profilers.has(p_name), "Can't change profiler state, no profiler: " + p_name);
+	ERR_FAIL_COND_MSG(!profilers.has(p_name), vformat("Can't change profiler state, no profiler: '%s'.", p_name));
 	Profiler &p = profilers[p_name];
 	if (p.toggle) {
 		p.toggle(p.data, p_enabled, p_opts);
@@ -85,7 +85,7 @@ void EngineDebugger::profiler_enable(const StringName &p_name, bool p_enabled, c
 }
 
 void EngineDebugger::profiler_add_frame_data(const StringName &p_name, const Array &p_data) {
-	ERR_FAIL_COND_MSG(!profilers.has(p_name), "Can't add frame data, no profiler: " + p_name);
+	ERR_FAIL_COND_MSG(!profilers.has(p_name), vformat("Can't add frame data, no profiler: '%s'.", p_name));
 	Profiler &p = profilers[p_name];
 	if (p.add) {
 		p.add(p.data, p_data);
@@ -106,7 +106,7 @@ bool EngineDebugger::has_capture(const StringName &p_name) {
 
 Error EngineDebugger::capture_parse(const StringName &p_name, const String &p_msg, const Array &p_args, bool &r_captured) {
 	r_captured = false;
-	ERR_FAIL_COND_V_MSG(!captures.has(p_name), ERR_UNCONFIGURED, "Capture not registered: " + p_name);
+	ERR_FAIL_COND_V_MSG(!captures.has(p_name), ERR_UNCONFIGURED, vformat("Capture not registered: '%s'.", p_name));
 	const Capture &cap = captures[p_name];
 	return cap.capture(cap.data, p_msg, p_args, r_captured);
 }
@@ -164,7 +164,7 @@ void EngineDebugger::initialize(const String &p_uri, bool p_skip_breakpoints, co
 	for (int i = 0; i < p_breakpoints.size(); i++) {
 		const String &bp = p_breakpoints[i];
 		int sp = bp.rfind(":");
-		ERR_CONTINUE_MSG(sp == -1, "Invalid breakpoint: '" + bp + "', expected file:line format.");
+		ERR_CONTINUE_MSG(sp == -1, vformat("Invalid breakpoint: '%s', expected file:line format.", bp));
 
 		singleton_script_debugger->insert_breakpoint(bp.substr(sp + 1, bp.length()).to_int(), bp.substr(0, sp));
 	}

core/debugger/remote_debugger.cpp

@@ -79,7 +79,7 @@ public:
 		for (int i = 0; i < custom_monitor_names.size(); i++) {
 			Variant monitor_value = performance->call("get_custom_monitor", custom_monitor_names[i]);
 			if (!monitor_value.is_num()) {
-				ERR_PRINT("Value of custom monitor '" + String(custom_monitor_names[i]) + "' is not a number");
+				ERR_PRINT(vformat("Value of custom monitor '%s' is not a number.", String(custom_monitor_names[i])));
 				arr[i + max] = Variant();
 			} else {
 				arr[i + max] = monitor_value;
@@ -569,7 +569,7 @@ void RemoteDebugger::debug(bool p_can_continue, bool p_is_error_breakpoint) {
 				bool captured = false;
 				ERR_CONTINUE(_try_capture(command, data, captured) != OK);
 				if (!captured) {
-					WARN_PRINT("Unknown message received from debugger: " + command);
+					WARN_PRINT(vformat("Unknown message received from debugger: %s.", command));
 				}
 			}
 		} else {

core/debugger/remote_debugger_peer.cpp

@@ -178,7 +178,7 @@ Error RemoteDebuggerPeerTCP::connect_to_host(const String &p_host, uint16_t p_po
 	}
 
 	if (tcp_client->get_status() != StreamPeerTCP::STATUS_CONNECTED) {
-		ERR_PRINT("Remote Debugger: Unable to connect. Status: " + String::num(tcp_client->get_status()) + ".");
+		ERR_PRINT(vformat("Remote Debugger: Unable to connect. Status: %s.", String::num(tcp_client->get_status())));
 		return FAILED;
 	}
 	connected = true;

core/extension/extension_api_dump.cpp

@@ -1363,7 +1363,7 @@ static bool compare_dict_array(const Dictionary &p_old_api, const Dictionary &p_
 		return true; // May just not have this array and its still good. Probably added recently.
 	}
 	bool failed = false;
-	ERR_FAIL_COND_V_MSG(!p_new_api.has(p_base_array), false, "New API lacks base array: " + p_base_array);
+	ERR_FAIL_COND_V_MSG(!p_new_api.has(p_base_array), false, vformat("New API lacks base array: %s", p_base_array));
 	Array new_api = p_new_api[p_base_array];
 	HashMap<String, Dictionary> new_api_assoc;
 
@@ -1515,7 +1515,7 @@ static bool compare_sub_dict_array(HashSet<String> &r_removed_classes_registered
 		return true; // May just not have this array and its still good. Probably added recently or optional.
 	}
 	bool failed = false;
-	ERR_FAIL_COND_V_MSG(!p_new_api.has(p_outer), false, "New API lacks base array: " + p_outer);
+	ERR_FAIL_COND_V_MSG(!p_new_api.has(p_outer), false, vformat("New API lacks base array: %s", p_outer));
 	Array new_api = p_new_api[p_outer];
 	HashMap<String, Dictionary> new_api_assoc;
 

core/extension/gdextension.cpp

@@ -355,8 +355,8 @@ void GDExtension::_register_extension_class_internal(GDExtensionClassLibraryPtr
 
 	StringName class_name = *reinterpret_cast<const StringName *>(p_class_name);
 	StringName parent_class_name = *reinterpret_cast<const StringName *>(p_parent_class_name);
-	ERR_FAIL_COND_MSG(!String(class_name).is_valid_unicode_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.");
+	ERR_FAIL_COND_MSG(!String(class_name).is_valid_unicode_identifier(), vformat("Attempt to register extension class '%s', which is not a valid class identifier.", class_name));
+	ERR_FAIL_COND_MSG(ClassDB::class_exists(class_name), vformat("Attempt to register extension class '%s', which appears to be already registered.", class_name));
 
 	Extension *parent_extension = nullptr;
 
@@ -370,7 +370,7 @@ void GDExtension::_register_extension_class_internal(GDExtensionClassLibraryPtr
 			//inheriting from engine class
 		}
 	} else {
-		ERR_FAIL_MSG("Attempt to register an extension class '" + String(class_name) + "' using non-existing parent class '" + String(parent_class_name) + "'.");
+		ERR_FAIL_MSG(vformat("Attempt to register an extension class '%s' using non-existing parent class '%s'.", String(class_name), String(parent_class_name)));
 	}
 
 #ifdef TOOLS_ENABLED
@@ -463,7 +463,7 @@ void GDExtension::_register_extension_class_method(GDExtensionClassLibraryPtr p_
 
 	StringName class_name = *reinterpret_cast<const StringName *>(p_class_name);
 	StringName method_name = *reinterpret_cast<const StringName *>(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), vformat("Attempt to register extension method '%s' for unexisting class '%s'.", String(method_name), class_name));
 
 #ifdef TOOLS_ENABLED
 	Extension *extension = &self->extension_classes[class_name];
@@ -513,7 +513,7 @@ void GDExtension::_register_extension_class_integer_constant(GDExtensionClassLib
 	StringName class_name = *reinterpret_cast<const StringName *>(p_class_name);
 	StringName enum_name = *reinterpret_cast<const StringName *>(p_enum_name);
 	StringName constant_name = *reinterpret_cast<const StringName *>(p_constant_name);
-	ERR_FAIL_COND_MSG(!self->extension_classes.has(class_name), "Attempt to register extension constant '" + constant_name + "' for unexisting class '" + class_name + "'.");
+	ERR_FAIL_COND_MSG(!self->extension_classes.has(class_name), vformat("Attempt to register extension constant '%s' for unexisting class '%s'.", constant_name, class_name));
 
 #ifdef TOOLS_ENABLED
 	// If the extension is still marked as reloading, that means it failed to register again.
@@ -537,7 +537,7 @@ void GDExtension::_register_extension_class_property_indexed(GDExtensionClassLib
 	StringName setter = *reinterpret_cast<const StringName *>(p_setter);
 	StringName getter = *reinterpret_cast<const StringName *>(p_getter);
 	String property_name = *reinterpret_cast<const StringName *>(p_info->name);
-	ERR_FAIL_COND_MSG(!self->extension_classes.has(class_name), "Attempt to register extension class property '" + property_name + "' for unexisting class '" + class_name + "'.");
+	ERR_FAIL_COND_MSG(!self->extension_classes.has(class_name), vformat("Attempt to register extension class property '%s' for unexisting class '%s'.", property_name, class_name));
 
 #ifdef TOOLS_ENABLED
 	// If the extension is still marked as reloading, that means it failed to register again.
@@ -558,7 +558,7 @@ void GDExtension::_register_extension_class_property_group(GDExtensionClassLibra
 	StringName class_name = *reinterpret_cast<const StringName *>(p_class_name);
 	String group_name = *reinterpret_cast<const String *>(p_group_name);
 	String prefix = *reinterpret_cast<const String *>(p_prefix);
-	ERR_FAIL_COND_MSG(!self->extension_classes.has(class_name), "Attempt to register extension class property group '" + group_name + "' for unexisting class '" + class_name + "'.");
+	ERR_FAIL_COND_MSG(!self->extension_classes.has(class_name), vformat("Attempt to register extension class property group '%s' for unexisting class '%s'.", group_name, class_name));
 
 #ifdef TOOLS_ENABLED
 	// If the extension is still marked as reloading, that means it failed to register again.
@@ -577,7 +577,7 @@ void GDExtension::_register_extension_class_property_subgroup(GDExtensionClassLi
 	StringName class_name = *reinterpret_cast<const StringName *>(p_class_name);
 	String subgroup_name = *reinterpret_cast<const String *>(p_subgroup_name);
 	String prefix = *reinterpret_cast<const String *>(p_prefix);
-	ERR_FAIL_COND_MSG(!self->extension_classes.has(class_name), "Attempt to register extension class property subgroup '" + subgroup_name + "' for unexisting class '" + class_name + "'.");
+	ERR_FAIL_COND_MSG(!self->extension_classes.has(class_name), vformat("Attempt to register extension class property subgroup '%s' for unexisting class '%s'.", subgroup_name, class_name));
 
 #ifdef TOOLS_ENABLED
 	// If the extension is still marked as reloading, that means it failed to register again.
@@ -595,7 +595,7 @@ void GDExtension::_register_extension_class_signal(GDExtensionClassLibraryPtr p_
 
 	StringName class_name = *reinterpret_cast<const StringName *>(p_class_name);
 	StringName signal_name = *reinterpret_cast<const StringName *>(p_signal_name);
-	ERR_FAIL_COND_MSG(!self->extension_classes.has(class_name), "Attempt to register extension class signal '" + signal_name + "' for unexisting class '" + class_name + "'.");
+	ERR_FAIL_COND_MSG(!self->extension_classes.has(class_name), vformat("Attempt to register extension class signal '%s' for unexisting class '%s'.", signal_name, class_name));
 
 #ifdef TOOLS_ENABLED
 	// If the extension is still marked as reloading, that means it failed to register again.
@@ -618,7 +618,7 @@ void GDExtension::_unregister_extension_class(GDExtensionClassLibraryPtr p_libra
 	GDExtension *self = reinterpret_cast<GDExtension *>(p_library);
 
 	StringName class_name = *reinterpret_cast<const StringName *>(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), vformat("Attempt to unregister unexisting extension class '%s'.", class_name));
 
 	Extension *ext = &self->extension_classes[class_name];
 #ifdef TOOLS_ENABLED
@@ -626,7 +626,7 @@ void GDExtension::_unregister_extension_class(GDExtensionClassLibraryPtr p_libra
 		self->_clear_extension(ext);
 	}
 #endif
-	ERR_FAIL_COND_MSG(ext->gdextension.children.size(), "Attempt to unregister class '" + class_name + "' while other extension classes inherit from it.");
+	ERR_FAIL_COND_MSG(ext->gdextension.children.size(), vformat("Attempt to unregister class '%s' while other extension classes inherit from it.", class_name));
 
 #ifdef TOOLS_ENABLED
 	ClassDB::unregister_extension_class(class_name, !ext->is_reloading);
@@ -664,13 +664,13 @@ void GDExtension::_get_library_path(GDExtensionClassLibraryPtr p_library, GDExte
 HashMap<StringName, GDExtensionInterfaceFunctionPtr> GDExtension::gdextension_interface_functions;
 
 void GDExtension::register_interface_function(const StringName &p_function_name, GDExtensionInterfaceFunctionPtr p_function_pointer) {
-	ERR_FAIL_COND_MSG(gdextension_interface_functions.has(p_function_name), "Attempt to register interface function '" + p_function_name + "', which appears to be already registered.");
+	ERR_FAIL_COND_MSG(gdextension_interface_functions.has(p_function_name), vformat("Attempt to register interface function '%s', which appears to be already registered.", p_function_name));
 	gdextension_interface_functions.insert(p_function_name, p_function_pointer);
 }
 
 GDExtensionInterfaceFunctionPtr GDExtension::get_interface_function(const StringName &p_function_name) {
 	GDExtensionInterfaceFunctionPtr *function = gdextension_interface_functions.getptr(p_function_name);
-	ERR_FAIL_NULL_V_MSG(function, nullptr, "Attempt to get non-existent interface function: " + String(p_function_name) + ".");
+	ERR_FAIL_NULL_V_MSG(function, nullptr, vformat("Attempt to get non-existent interface function: '%s'.", String(p_function_name)));
 	return *function;
 }
 
@@ -680,8 +680,8 @@ Error GDExtension::open_library(const String &p_path, const Ref<GDExtensionLoade
 
 	Error err = loader->open_library(p_path);
 
-	ERR_FAIL_COND_V_MSG(err == ERR_FILE_NOT_FOUND, err, "GDExtension dynamic library not found: " + p_path);
-	ERR_FAIL_COND_V_MSG(err != OK, err, "Can't open GDExtension dynamic library: " + p_path);
+	ERR_FAIL_COND_V_MSG(err == ERR_FILE_NOT_FOUND, err, vformat("GDExtension dynamic library not found: '%s'.", p_path));
+	ERR_FAIL_COND_V_MSG(err != OK, err, vformat("Can't open GDExtension dynamic library: '%s'.", p_path));
 
 	err = loader->initialize(&gdextension_get_proc_address, this, &initialization);
 

core/extension/gdextension_interface.cpp

@@ -1526,7 +1526,7 @@ static GDExtensionMethodBindPtr gdextension_classdb_get_method_bind(GDExtensionC
 #endif
 
 	if (!mb && exists) {
-		ERR_PRINT("Method '" + classname + "." + methodname + "' has changed and no compatibility fallback has been provided. Please open an issue.");
+		ERR_PRINT(vformat("Method '%s.%s' has changed and no compatibility fallback has been provided. Please open an issue.", classname, methodname));
 		return nullptr;
 	}
 	ERR_FAIL_NULL_V(mb, nullptr);

core/extension/gdextension_library_loader.cpp

@@ -219,7 +219,7 @@ Error GDExtensionLibraryLoader::initialize(GDExtensionInterfaceGetProcAddress p_
 	Error err = OS::get_singleton()->get_dynamic_library_symbol_handle(library, entry_symbol, entry_funcptr, false);
 
 	if (err != OK) {
-		ERR_PRINT("GDExtension entry point '" + entry_symbol + "' not found in library " + library_path);
+		ERR_PRINT(vformat("GDExtension entry point '%s' not found in library %s.", entry_symbol, library_path));
 		return err;
 	}
 
@@ -230,7 +230,7 @@ Error GDExtensionLibraryLoader::initialize(GDExtensionInterfaceGetProcAddress p_
 	if (ret) {
 		return OK;
 	} else {
-		ERR_PRINT("GDExtension initialization function '" + entry_symbol + "' returned an error.");
+		ERR_PRINT(vformat("GDExtension initialization function '%s' returned an error.", entry_symbol));
 		return FAILED;
 	}
 }
@@ -272,12 +272,12 @@ Error GDExtensionLibraryLoader::parse_gdextension_file(const String &p_path) {
 	Error err = config->load(p_path);
 
 	if (err != OK) {
-		ERR_PRINT("Error loading GDExtension configuration file: " + p_path);
+		ERR_PRINT(vformat("Error loading GDExtension configuration file: '%s'.", p_path));
 		return err;
 	}
 
 	if (!config->has_section_key("configuration", "entry_symbol")) {
-		ERR_PRINT("GDExtension configuration file must contain a \"configuration/entry_symbol\" key: " + p_path);
+		ERR_PRINT(vformat("GDExtension configuration file must contain a \"configuration/entry_symbol\" key: '%s'.", p_path));
 		return ERR_INVALID_DATA;
 	}
 
@@ -296,7 +296,7 @@ Error GDExtensionLibraryLoader::parse_gdextension_file(const String &p_path) {
 			}
 		}
 	} else {
-		ERR_PRINT("GDExtension configuration file must contain a \"configuration/compatibility_minimum\" key: " + p_path);
+		ERR_PRINT(vformat("GDExtension configuration file must contain a \"configuration/compatibility_minimum\" key: '%s'.", p_path));
 		return ERR_INVALID_DATA;
 	}
 

core/extension/gdextension_manager.cpp

@@ -258,7 +258,7 @@ void GDExtensionManager::load_extensions() {
 		String s = f->get_line().strip_edges();
 		if (!s.is_empty()) {
 			LoadStatus err = load_extension(s);
-			ERR_CONTINUE_MSG(err == LOAD_STATUS_FAILED, "Error loading extension: " + s);
+			ERR_CONTINUE_MSG(err == LOAD_STATUS_FAILED, vformat("Error loading extension: '%s'.", s));
 		}
 	}
 

core/input/input_map.cpp

@@ -114,7 +114,7 @@ void InputMap::get_argument_options(const StringName &p_function, int p_idx, Lis
 #endif
 
 void InputMap::add_action(const StringName &p_action, float p_deadzone) {
-	ERR_FAIL_COND_MSG(input_map.has(p_action), "InputMap already has action \"" + String(p_action) + "\".");
+	ERR_FAIL_COND_MSG(input_map.has(p_action), vformat("InputMap already has action \"%s\".", String(p_action)));
 	input_map[p_action] = Action();
 	static int last_id = 1;
 	input_map[p_action].id = last_id;

core/io/dir_access.cpp

@@ -177,7 +177,7 @@ Error DirAccess::make_dir_recursive(const String &p_dir) {
 		curpath = curpath.path_join(subdirs[i]);
 		Error err = make_dir(curpath);
 		if (err != OK && err != ERR_ALREADY_EXISTS) {
-			ERR_FAIL_V_MSG(err, "Could not create directory: " + curpath);
+			ERR_FAIL_V_MSG(err, vformat("Could not create directory: '%s'.", curpath));
 		}
 	}
 
@@ -239,7 +239,7 @@ Ref<DirAccess> DirAccess::create_for_path(const String &p_path) {
 
 Ref<DirAccess> DirAccess::open(const String &p_path, Error *r_error) {
 	Ref<DirAccess> da = create_for_path(p_path);
-	ERR_FAIL_COND_V_MSG(da.is_null(), nullptr, "Cannot create DirAccess for path '" + p_path + "'.");
+	ERR_FAIL_COND_V_MSG(da.is_null(), nullptr, vformat("Cannot create DirAccess for path '%s'.", p_path));
 	Error err = da->change_dir(p_path);
 	if (r_error) {
 		*r_error = err;
@@ -345,10 +345,10 @@ Error DirAccess::copy(const String &p_from, const String &p_to, int p_chmod_flag
 	Error err;
 	{
 		Ref<FileAccess> fsrc = FileAccess::open(p_from, FileAccess::READ, &err);
-		ERR_FAIL_COND_V_MSG(err != OK, err, "Failed to open " + p_from);
+		ERR_FAIL_COND_V_MSG(err != OK, err, vformat("Failed to open '%s'.", p_from));
 
 		Ref<FileAccess> fdst = FileAccess::open(p_to, FileAccess::WRITE, &err);
-		ERR_FAIL_COND_V_MSG(err != OK, err, "Failed to open " + p_to);
+		ERR_FAIL_COND_V_MSG(err != OK, err, vformat("Failed to open '%s'.", p_to));
 
 		const size_t copy_buffer_limit = 65536; // 64 KB
 
@@ -444,11 +444,11 @@ Error DirAccess::_copy_dir(Ref<DirAccess> &p_target_da, const String &p_to, int
 		String target_dir = p_to + rel_path;
 		if (!p_target_da->dir_exists(target_dir)) {
 			Error err = p_target_da->make_dir(target_dir);
-			ERR_FAIL_COND_V_MSG(err != OK, err, "Cannot create directory '" + target_dir + "'.");
+			ERR_FAIL_COND_V_MSG(err != OK, err, vformat("Cannot create directory '%s'.", target_dir));
 		}
 
 		Error err = change_dir(rel_path);
-		ERR_FAIL_COND_V_MSG(err != OK, err, "Cannot change current directory to '" + rel_path + "'.");
+		ERR_FAIL_COND_V_MSG(err != OK, err, vformat("Cannot change current directory to '%s'.", rel_path));
 
 		err = _copy_dir(p_target_da, p_to + rel_path + "/", p_chmod_flags, p_copy_links);
 		if (err) {
@@ -466,11 +466,11 @@ Error DirAccess::copy_dir(const String &p_from, String p_to, int p_chmod_flags,
 	ERR_FAIL_COND_V_MSG(!dir_exists(p_from), ERR_FILE_NOT_FOUND, "Source directory doesn't exist.");
 
 	Ref<DirAccess> target_da = DirAccess::create_for_path(p_to);
-	ERR_FAIL_COND_V_MSG(target_da.is_null(), ERR_CANT_CREATE, "Cannot create DirAccess for path '" + p_to + "'.");
+	ERR_FAIL_COND_V_MSG(target_da.is_null(), ERR_CANT_CREATE, vformat("Cannot create DirAccess for path '%s'.", p_to));
 
 	if (!target_da->dir_exists(p_to)) {
 		Error err = target_da->make_dir_recursive(p_to);
-		ERR_FAIL_COND_V_MSG(err != OK, err, "Cannot create directory '" + p_to + "'.");
+		ERR_FAIL_COND_V_MSG(err != OK, err, vformat("Cannot create directory '%s'.", p_to));
 	}
 
 	if (!p_to.ends_with("/")) {

core/io/dir_access.h

@@ -116,10 +116,10 @@ public:
 		Ref<DirAccess> da = create(ACCESS_FILESYSTEM);
 		if (da->file_exists(p_path)) {
 			if (da->remove(p_path) != OK) {
-				ERR_FAIL_MSG("Cannot remove file or directory: " + p_path);
+				ERR_FAIL_MSG(vformat("Cannot remove file or directory: '%s'.", p_path));
 			}
 		} else {
-			ERR_FAIL_MSG("Cannot remove non-existent file or directory: " + p_path);
+			ERR_FAIL_MSG(vformat("Cannot remove non-existent file or directory: '%s'.", p_path));
 		}
 	}
 

core/io/file_access.cpp

@@ -459,7 +459,7 @@ Vector<uint8_t> FileAccess::get_buffer(int64_t p_length) const {
 	}
 
 	Error err = data.resize(p_length);
-	ERR_FAIL_COND_V_MSG(err != OK, data, "Can't resize data to " + itos(p_length) + " elements.");
+	ERR_FAIL_COND_V_MSG(err != OK, data, vformat("Can't resize data to %d elements.", p_length));
 
 	uint8_t *w = data.ptrw();
 	int64_t len = get_buffer(w, p_length);
@@ -540,7 +540,7 @@ uint64_t FileAccess::get_modified_time(const String &p_file) {
 	}
 
 	Ref<FileAccess> fa = create_for_path(p_file);
-	ERR_FAIL_COND_V_MSG(fa.is_null(), 0, "Cannot create FileAccess for path '" + p_file + "'.");
+	ERR_FAIL_COND_V_MSG(fa.is_null(), 0, vformat("Cannot create FileAccess for path '%s'.", p_file));
 
 	uint64_t mt = fa->_get_modified_time(p_file);
 	return mt;
@@ -552,7 +552,7 @@ BitField<FileAccess::UnixPermissionFlags> FileAccess::get_unix_permissions(const
 	}
 
 	Ref<FileAccess> fa = create_for_path(p_file);
-	ERR_FAIL_COND_V_MSG(fa.is_null(), 0, "Cannot create FileAccess for path '" + p_file + "'.");
+	ERR_FAIL_COND_V_MSG(fa.is_null(), 0, vformat("Cannot create FileAccess for path '%s'.", p_file));
 
 	return fa->_get_unix_permissions(p_file);
 }
@@ -563,7 +563,7 @@ Error FileAccess::set_unix_permissions(const String &p_file, BitField<FileAccess
 	}
 
 	Ref<FileAccess> fa = create_for_path(p_file);
-	ERR_FAIL_COND_V_MSG(fa.is_null(), ERR_CANT_CREATE, "Cannot create FileAccess for path '" + p_file + "'.");
+	ERR_FAIL_COND_V_MSG(fa.is_null(), ERR_CANT_CREATE, vformat("Cannot create FileAccess for path '%s'.", p_file));
 
 	Error err = fa->_set_unix_permissions(p_file, p_permissions);
 	return err;
@@ -575,7 +575,7 @@ bool FileAccess::get_hidden_attribute(const String &p_file) {
 	}
 
 	Ref<FileAccess> fa = create_for_path(p_file);
-	ERR_FAIL_COND_V_MSG(fa.is_null(), false, "Cannot create FileAccess for path '" + p_file + "'.");
+	ERR_FAIL_COND_V_MSG(fa.is_null(), false, vformat("Cannot create FileAccess for path '%s'.", p_file));
 
 	return fa->_get_hidden_attribute(p_file);
 }
@@ -586,7 +586,7 @@ Error FileAccess::set_hidden_attribute(const String &p_file, bool p_hidden) {
 	}
 
 	Ref<FileAccess> fa = create_for_path(p_file);
-	ERR_FAIL_COND_V_MSG(fa.is_null(), ERR_CANT_CREATE, "Cannot create FileAccess for path '" + p_file + "'.");
+	ERR_FAIL_COND_V_MSG(fa.is_null(), ERR_CANT_CREATE, vformat("Cannot create FileAccess for path '%s'.", p_file));
 
 	Error err = fa->_set_hidden_attribute(p_file, p_hidden);
 	return err;
@@ -598,7 +598,7 @@ bool FileAccess::get_read_only_attribute(const String &p_file) {
 	}
 
 	Ref<FileAccess> fa = create_for_path(p_file);
-	ERR_FAIL_COND_V_MSG(fa.is_null(), false, "Cannot create FileAccess for path '" + p_file + "'.");
+	ERR_FAIL_COND_V_MSG(fa.is_null(), false, vformat("Cannot create FileAccess for path '%s'.", p_file));
 
 	return fa->_get_read_only_attribute(p_file);
 }
@@ -609,7 +609,7 @@ Error FileAccess::set_read_only_attribute(const String &p_file, bool p_ro) {
 	}
 
 	Ref<FileAccess> fa = create_for_path(p_file);
-	ERR_FAIL_COND_V_MSG(fa.is_null(), ERR_CANT_CREATE, "Cannot create FileAccess for path '" + p_file + "'.");
+	ERR_FAIL_COND_V_MSG(fa.is_null(), ERR_CANT_CREATE, vformat("Cannot create FileAccess for path '%s'.", p_file));
 
 	Error err = fa->_set_read_only_attribute(p_file, p_ro);
 	return err;
@@ -697,7 +697,7 @@ Vector<uint8_t> FileAccess::get_file_as_bytes(const String &p_path, Error *r_err
 		if (r_error) { // if error requested, do not throw error
 			return Vector<uint8_t>();
 		}
-		ERR_FAIL_V_MSG(Vector<uint8_t>(), "Can't open file from path '" + String(p_path) + "'.");
+		ERR_FAIL_V_MSG(Vector<uint8_t>(), vformat("Can't open file from path '%s'.", String(p_path)));
 	}
 	Vector<uint8_t> data;
 	data.resize(f->get_length());
@@ -715,7 +715,7 @@ String FileAccess::get_file_as_string(const String &p_path, Error *r_error) {
 		if (r_error) {
 			return String();
 		}
-		ERR_FAIL_V_MSG(String(), "Can't get file as string from path '" + String(p_path) + "'.");
+		ERR_FAIL_V_MSG(String(), vformat("Can't get file as string from path '%s'.", String(p_path)));
 	}
 
 	String ret;

core/io/file_access_compressed.cpp

@@ -58,7 +58,7 @@ Error FileAccessCompressed::open_after_magic(Ref<FileAccess> p_base) {
 	block_size = f->get_32();
 	if (block_size == 0) {
 		f.unref();
-		ERR_FAIL_V_MSG(ERR_FILE_CORRUPT, "Can't open compressed file '" + p_base->get_path() + "' with block size 0, it is corrupted.");
+		ERR_FAIL_V_MSG(ERR_FILE_CORRUPT, vformat("Can't open compressed file '%s' with block size 0, it is corrupted.", p_base->get_path()));
 	}
 	read_total = f->get_32();
 	uint32_t bc = (read_total / block_size) + 1;

core/io/file_access_encrypted.cpp

@@ -37,7 +37,7 @@
 #include <stdio.h>
 
 Error FileAccessEncrypted::open_and_parse(Ref<FileAccess> p_base, const Vector<uint8_t> &p_key, Mode p_mode, bool p_with_magic) {
-	ERR_FAIL_COND_V_MSG(file.is_valid(), ERR_ALREADY_IN_USE, "Can't open file while another file from path '" + file->get_path_absolute() + "' is open.");
+	ERR_FAIL_COND_V_MSG(file.is_valid(), ERR_ALREADY_IN_USE, vformat("Can't open file while another file from path '%s' is open.", file->get_path_absolute()));
 	ERR_FAIL_COND_V(p_key.size() != 32, ERR_INVALID_PARAMETER);
 
 	pos = 0;

core/io/file_access_memory.cpp

@@ -85,7 +85,7 @@ Error FileAccessMemory::open_internal(const String &p_path, int p_mode_flags) {
 	//name = DirAccess::normalize_path(name);
 
 	HashMap<String, Vector<uint8_t>>::Iterator E = files->find(name);
-	ERR_FAIL_COND_V_MSG(!E, ERR_FILE_NOT_FOUND, "Can't find file '" + p_path + "'.");
+	ERR_FAIL_COND_V_MSG(!E, ERR_FILE_NOT_FOUND, vformat("Can't find file '%s'.", p_path));
 
 	data = E->value.ptrw();
 	length = E->value.size();

core/io/file_access_pack.cpp

@@ -223,8 +223,8 @@ bool PackedSourcePCK::try_open_pack(const String &p_path, bool p_replace_files,
 	uint32_t ver_minor = f->get_32();
 	f->get_32(); // patch number, not used for validation.
 
-	ERR_FAIL_COND_V_MSG(version != PACK_FORMAT_VERSION, false, "Pack version unsupported: " + itos(version) + ".");
-	ERR_FAIL_COND_V_MSG(ver_major > VERSION_MAJOR || (ver_major == VERSION_MAJOR && ver_minor > VERSION_MINOR), false, "Pack created with a newer version of the engine: " + itos(ver_major) + "." + itos(ver_minor) + ".");
+	ERR_FAIL_COND_V_MSG(version != PACK_FORMAT_VERSION, false, vformat("Pack version unsupported: %d.", version));
+	ERR_FAIL_COND_V_MSG(ver_major > VERSION_MAJOR || (ver_major == VERSION_MAJOR && ver_minor > VERSION_MINOR), false, vformat("Pack created with a newer version of the engine: %d.%d.", ver_major, ver_minor));
 
 	uint32_t pack_flags = f->get_32();
 	uint64_t file_base = f->get_64();
@@ -386,7 +386,7 @@ void FileAccessPack::close() {
 FileAccessPack::FileAccessPack(const String &p_path, const PackedData::PackedFile &p_file) :
 		pf(p_file),
 		f(FileAccess::open(pf.pack, FileAccess::READ)) {
-	ERR_FAIL_COND_MSG(f.is_null(), "Can't open pack-referenced file '" + String(pf.pack) + "'.");
+	ERR_FAIL_COND_MSG(f.is_null(), vformat("Can't open pack-referenced file '%s'.", String(pf.pack)));
 
 	f->seek(pf.offset);
 	off = pf.offset;
@@ -394,7 +394,7 @@ FileAccessPack::FileAccessPack(const String &p_path, const PackedData::PackedFil
 	if (pf.encrypted) {
 		Ref<FileAccessEncrypted> fae;
 		fae.instantiate();
-		ERR_FAIL_COND_MSG(fae.is_null(), "Can't open encrypted pack-referenced file '" + String(pf.pack) + "'.");
+		ERR_FAIL_COND_MSG(fae.is_null(), vformat("Can't open encrypted pack-referenced file '%s'.", String(pf.pack)));
 
 		Vector<uint8_t> key;
 		key.resize(32);
@@ -403,7 +403,7 @@ FileAccessPack::FileAccessPack(const String &p_path, const PackedData::PackedFil
 		}
 
 		Error err = fae->open_and_parse(f, key, FileAccessEncrypted::MODE_READ, false);
-		ERR_FAIL_COND_MSG(err, "Can't open encrypted pack-referenced file '" + String(pf.pack) + "'.");
+		ERR_FAIL_COND_MSG(err, vformat("Can't open encrypted pack-referenced file '%s'.", String(pf.pack)));
 		f = fae;
 		off = 0;
 	}

core/io/file_access_zip.cpp

@@ -116,7 +116,7 @@ void ZipArchive::close_handle(unzFile p_file) const {
 }
 
 unzFile ZipArchive::get_file_handle(const String &p_file) const {
-	ERR_FAIL_COND_V_MSG(!file_exists(p_file), nullptr, "File '" + p_file + " doesn't exist.");
+	ERR_FAIL_COND_V_MSG(!file_exists(p_file), nullptr, vformat("File '%s' doesn't exist.", p_file));
 	File file = files[p_file];
 
 	zlib_filefunc_def io;
@@ -136,7 +136,7 @@ unzFile ZipArchive::get_file_handle(const String &p_file) const {
 	io.free_mem = godot_free;
 
 	unzFile pkg = unzOpen2(packages[file.package].filename.utf8().get_data(), &io);
-	ERR_FAIL_NULL_V_MSG(pkg, nullptr, "Cannot open file '" + packages[file.package].filename + "'.");
+	ERR_FAIL_NULL_V_MSG(pkg, nullptr, vformat("Cannot open file '%s'.", packages[file.package].filename));
 	int unz_err = unzGoToFilePos(pkg, &file.file_pos);
 	if (unz_err != UNZ_OK || unzOpenCurrentFile(pkg) != UNZ_OK) {
 		unzClose(pkg);

core/io/http_client.cpp

@@ -100,9 +100,9 @@ String HTTPClient::query_string_from_dict(const Dictionary &p_dict) {
 Error HTTPClient::verify_headers(const Vector<String> &p_headers) {
 	for (int i = 0; i < p_headers.size(); i++) {
 		String sanitized = p_headers[i].strip_edges();
-		ERR_FAIL_COND_V_MSG(sanitized.is_empty(), ERR_INVALID_PARAMETER, "Invalid HTTP header at index " + itos(i) + ": empty.");
+		ERR_FAIL_COND_V_MSG(sanitized.is_empty(), ERR_INVALID_PARAMETER, vformat("Invalid HTTP header at index %d: empty.", i));
 		ERR_FAIL_COND_V_MSG(sanitized.find(":") < 1, ERR_INVALID_PARAMETER,
-				"Invalid HTTP header at index " + itos(i) + ": String must contain header-value pair, delimited by ':', but was: " + p_headers[i]);
+				vformat("Invalid HTTP header at index %d: String must contain header-value pair, delimited by ':', but was: '%s'.", i, p_headers[i]));
 	}
 
 	return OK;

core/io/image.cpp

@@ -535,7 +535,7 @@ static bool _are_formats_compatible(Image::Format p_format0, Image::Format p_for
 }
 
 void Image::convert(Format p_new_format) {
-	ERR_FAIL_INDEX_MSG(p_new_format, FORMAT_MAX, "The Image format specified (" + itos(p_new_format) + ") is out of range. See Image's Format enum.");
+	ERR_FAIL_INDEX_MSG(p_new_format, FORMAT_MAX, vformat("The Image format specified (%d) is out of range. See Image's Format enum.", p_new_format));
 	if (data.size() == 0) {
 		return;
 	}
@@ -1132,9 +1132,9 @@ void Image::resize(int p_width, int p_height, Interpolation p_interpolation) {
 
 	ERR_FAIL_COND_MSG(p_width <= 0, "Image width must be greater than 0.");
 	ERR_FAIL_COND_MSG(p_height <= 0, "Image height must be greater than 0.");
-	ERR_FAIL_COND_MSG(p_width > MAX_WIDTH, "Image width cannot be greater than " + itos(MAX_WIDTH) + ".");
-	ERR_FAIL_COND_MSG(p_height > MAX_HEIGHT, "Image height cannot be greater than " + itos(MAX_HEIGHT) + ".");
-	ERR_FAIL_COND_MSG(p_width * p_height > MAX_PIXELS, "Too many pixels for image, maximum is " + itos(MAX_PIXELS));
+	ERR_FAIL_COND_MSG(p_width > MAX_WIDTH, vformat("Image width cannot be greater than %d pixels.", MAX_WIDTH));
+	ERR_FAIL_COND_MSG(p_height > MAX_HEIGHT, vformat("Image height cannot be greater than %d pixels.", MAX_HEIGHT));
+	ERR_FAIL_COND_MSG(p_width * p_height > MAX_PIXELS, vformat("Too many pixels for image, maximum is %d pixels.", MAX_PIXELS));
 
 	if (p_width == width && p_height == height) {
 		return;
@@ -1435,8 +1435,8 @@ void Image::crop_from_point(int p_x, int p_y, int p_width, int p_height) {
 	ERR_FAIL_COND_MSG(p_y < 0, "Start y position cannot be smaller than 0.");
 	ERR_FAIL_COND_MSG(p_width <= 0, "Width of image must be greater than 0.");
 	ERR_FAIL_COND_MSG(p_height <= 0, "Height of image must be greater than 0.");
-	ERR_FAIL_COND_MSG(p_x + p_width > MAX_WIDTH, "End x position cannot be greater than " + itos(MAX_WIDTH) + ".");
-	ERR_FAIL_COND_MSG(p_y + p_height > MAX_HEIGHT, "End y position cannot be greater than " + itos(MAX_HEIGHT) + ".");
+	ERR_FAIL_COND_MSG(p_x + p_width > MAX_WIDTH, vformat("End x position cannot be greater than %d.", MAX_WIDTH));
+	ERR_FAIL_COND_MSG(p_y + p_height > MAX_HEIGHT, vformat("End y position cannot be greater than %d.", MAX_HEIGHT));
 
 	/* to save memory, cropping should be done in-place, however, since this function
 	   will most likely either not be used much, or in critical areas, for now it won't, because
@@ -1484,8 +1484,8 @@ void Image::crop(int p_width, int p_height) {
 
 void Image::rotate_90(ClockDirection p_direction) {
 	ERR_FAIL_COND_MSG(!_can_modify(format), "Cannot rotate in compressed or custom image formats.");
-	ERR_FAIL_COND_MSG(width <= 0, "The Image width specified (" + itos(width) + " pixels) must be greater than 0 pixels.");
-	ERR_FAIL_COND_MSG(height <= 0, "The Image height specified (" + itos(height) + " pixels) must be greater than 0 pixels.");
+	ERR_FAIL_COND_MSG(width <= 0, vformat("The Image width specified (%d pixels) must be greater than 0 pixels.", width));
+	ERR_FAIL_COND_MSG(height <= 0, vformat("The Image height specified (%d pixels) must be greater than 0 pixels.", height));
 
 	bool used_mipmaps = has_mipmaps();
 	if (used_mipmaps) {
@@ -1602,8 +1602,8 @@ void Image::rotate_90(ClockDirection p_direction) {
 
 void Image::rotate_180() {
 	ERR_FAIL_COND_MSG(!_can_modify(format), "Cannot rotate in compressed or custom image formats.");
-	ERR_FAIL_COND_MSG(width <= 0, "The Image width specified (" + itos(width) + " pixels) must be greater than 0 pixels.");
-	ERR_FAIL_COND_MSG(height <= 0, "The Image height specified (" + itos(height) + " pixels) must be greater than 0 pixels.");
+	ERR_FAIL_COND_MSG(width <= 0, vformat("The Image width specified (%d pixels) must be greater than 0 pixels.", width));
+	ERR_FAIL_COND_MSG(height <= 0, vformat("The Image height specified (%d pixels) must be greater than 0 pixels.", height));
 
 	bool used_mipmaps = has_mipmaps();
 	if (used_mipmaps) {
@@ -2249,15 +2249,15 @@ void Image::set_data(int p_width, int p_height, bool p_use_mipmaps, Format p_for
 }
 
 void Image::initialize_data(int p_width, int p_height, bool p_use_mipmaps, Format p_format) {
-	ERR_FAIL_COND_MSG(p_width <= 0, "The Image width specified (" + itos(p_width) + " pixels) must be greater than 0 pixels.");
-	ERR_FAIL_COND_MSG(p_height <= 0, "The Image height specified (" + itos(p_height) + " pixels) must be greater than 0 pixels.");
+	ERR_FAIL_COND_MSG(p_width <= 0, vformat("The Image width specified (%d pixels) must be greater than 0 pixels.", p_width));
+	ERR_FAIL_COND_MSG(p_height <= 0, vformat("The Image height specified (%d pixels) must be greater than 0 pixels.", p_height));
 	ERR_FAIL_COND_MSG(p_width > MAX_WIDTH,
-			"The Image width specified (" + itos(p_width) + " pixels) cannot be greater than " + itos(MAX_WIDTH) + "pixels.");
+			vformat("The Image width specified (%d pixels) cannot be greater than %d pixels.", p_width, MAX_WIDTH));
 	ERR_FAIL_COND_MSG(p_height > MAX_HEIGHT,
-			"The Image height specified (" + itos(p_height) + " pixels) cannot be greater than " + itos(MAX_HEIGHT) + "pixels.");
+			vformat("The Image height specified (%d pixels) cannot be greater than %d pixels.", p_height, MAX_HEIGHT));
 	ERR_FAIL_COND_MSG(p_width * p_height > MAX_PIXELS,
-			"Too many pixels for Image. Maximum is " + itos(MAX_WIDTH) + "x" + itos(MAX_HEIGHT) + " = " + itos(MAX_PIXELS) + "pixels.");
-	ERR_FAIL_INDEX_MSG(p_format, FORMAT_MAX, "The Image format specified (" + itos(p_format) + ") is out of range. See Image's Format enum.");
+			vformat("Too many pixels for Image. Maximum is %dx%d = %d pixels.", MAX_WIDTH, MAX_HEIGHT, MAX_PIXELS));
+	ERR_FAIL_INDEX_MSG(p_format, FORMAT_MAX, vformat("The Image format specified (%d) is out of range. See Image's Format enum.", p_format));
 
 	int mm = 0;
 	int64_t size = _get_dst_image_size(p_width, p_height, p_format, mm, p_use_mipmaps ? -1 : 0);
@@ -2275,15 +2275,15 @@ void Image::initialize_data(int p_width, int p_height, bool p_use_mipmaps, Forma
 }
 
 void Image::initialize_data(int p_width, int p_height, bool p_use_mipmaps, Format p_format, const Vector<uint8_t> &p_data) {
-	ERR_FAIL_COND_MSG(p_width <= 0, "The Image width specified (" + itos(p_width) + " pixels) must be greater than 0 pixels.");
-	ERR_FAIL_COND_MSG(p_height <= 0, "The Image height specified (" + itos(p_height) + " pixels) must be greater than 0 pixels.");
+	ERR_FAIL_COND_MSG(p_width <= 0, vformat("The Image width specified (%d pixels) must be greater than 0 pixels.", p_width));
+	ERR_FAIL_COND_MSG(p_height <= 0, vformat("The Image height specified (%d pixels) must be greater than 0 pixels.", p_height));
 	ERR_FAIL_COND_MSG(p_width > MAX_WIDTH,
-			"The Image width specified (" + itos(p_width) + " pixels) cannot be greater than " + itos(MAX_WIDTH) + " pixels.");
+			vformat("The Image width specified (%d pixels) cannot be greater than %d pixels.", p_width, MAX_WIDTH));
 	ERR_FAIL_COND_MSG(p_height > MAX_HEIGHT,
-			"The Image height specified (" + itos(p_height) + " pixels) cannot be greater than " + itos(MAX_HEIGHT) + " pixels.");
+			vformat("The Image height specified (%d pixels) cannot be greater than %d pixels.", p_height, MAX_HEIGHT));
 	ERR_FAIL_COND_MSG(p_width * p_height > MAX_PIXELS,
-			"Too many pixels for Image. Maximum is " + itos(MAX_WIDTH) + "x" + itos(MAX_HEIGHT) + " = " + itos(MAX_PIXELS) + "pixels .");
-	ERR_FAIL_INDEX_MSG(p_format, FORMAT_MAX, "The Image format specified (" + itos(p_format) + ") is out of range. See Image's Format enum.");
+			vformat("Too many pixels for Image. Maximum is %dx%d = %d pixels.", MAX_WIDTH, MAX_HEIGHT, MAX_PIXELS));
+	ERR_FAIL_INDEX_MSG(p_format, FORMAT_MAX, vformat("The Image format specified (%d) is out of range. See Image's Format enum.", p_format));
 
 	int mm;
 	int64_t size = _get_dst_image_size(p_width, p_height, p_format, mm, p_use_mipmaps ? -1 : 0);
@@ -2577,7 +2577,7 @@ Image::AlphaMode Image::detect_alpha() const {
 Error Image::load(const String &p_path) {
 #ifdef DEBUG_ENABLED
 	if (p_path.begins_with("res://") && ResourceLoader::exists(p_path)) {
-		WARN_PRINT("Loaded resource as image file, this will not work on export: '" + p_path + "'. Instead, import the image file as an Image resource and load it normally as a resource.");
+		WARN_PRINT(vformat("Loaded resource as image file, this will not work on export: '%s'. Instead, import the image file as an Image resource and load it normally as a resource.", p_path));
 	}
 #endif
 	return ImageLoader::load_image(p_path, this);
@@ -2586,7 +2586,7 @@ Error Image::load(const String &p_path) {
 Ref<Image> Image::load_from_file(const String &p_path) {
 #ifdef DEBUG_ENABLED
 	if (p_path.begins_with("res://") && ResourceLoader::exists(p_path)) {
-		WARN_PRINT("Loaded resource as image file, this will not work on export: '" + p_path + "'. Instead, import the image file as an Image resource and load it normally as a resource.");
+		WARN_PRINT(vformat("Loaded resource as image file, this will not work on export: '%s'. Instead, import the image file as an Image resource and load it normally as a resource.", p_path));
 	}
 #endif
 	Ref<Image> image;
@@ -2649,7 +2649,7 @@ Error Image::save_webp(const String &p_path, const bool p_lossy, const float p_q
 	if (save_webp_func == nullptr) {
 		return ERR_UNAVAILABLE;
 	}
-	ERR_FAIL_COND_V_MSG(p_lossy && !(0.0f <= p_quality && p_quality <= 1.0f), ERR_INVALID_PARAMETER, "The WebP lossy quality was set to " + rtos(p_quality) + ", which is not valid. WebP lossy quality must be between 0.0 and 1.0 (inclusive).");
+	ERR_FAIL_COND_V_MSG(p_lossy && !(0.0f <= p_quality && p_quality <= 1.0f), ERR_INVALID_PARAMETER, vformat("The WebP lossy quality was set to %f, which is not valid. WebP lossy quality must be between 0.0 and 1.0 (inclusive).", p_quality));
 
 	return save_webp_func(p_path, Ref<Image>((Image *)this), p_lossy, p_quality);
 }
@@ -2658,7 +2658,7 @@ Vector<uint8_t> Image::save_webp_to_buffer(const bool p_lossy, const float p_qua
 	if (save_webp_buffer_func == nullptr) {
 		return Vector<uint8_t>();
 	}
-	ERR_FAIL_COND_V_MSG(p_lossy && !(0.0f <= p_quality && p_quality <= 1.0f), Vector<uint8_t>(), "The WebP lossy quality was set to " + rtos(p_quality) + ", which is not valid. WebP lossy quality must be between 0.0 and 1.0 (inclusive).");
+	ERR_FAIL_COND_V_MSG(p_lossy && !(0.0f <= p_quality && p_quality <= 1.0f), Vector<uint8_t>(), vformat("The WebP lossy quality was set to %f, which is not valid. WebP lossy quality must be between 0.0 and 1.0 (inclusive).", p_quality));
 
 	return save_webp_buffer_func(Ref<Image>((Image *)this), p_lossy, p_quality);
 }

core/io/image_loader.cpp

@@ -87,7 +87,7 @@ Error ImageLoader::load_image(const String &p_file, Ref<Image> p_image, Ref<File
 	if (f.is_null()) {
 		Error err;
 		f = FileAccess::open(p_file, FileAccess::READ, &err);
-		ERR_FAIL_COND_V_MSG(f.is_null(), err, "Error opening file '" + p_file + "'.");
+		ERR_FAIL_COND_V_MSG(f.is_null(), err, vformat("Error opening file '%s'.", p_file));
 	}
 
 	String extension = p_file.get_extension();
@@ -98,7 +98,7 @@ Error ImageLoader::load_image(const String &p_file, Ref<Image> p_image, Ref<File
 		}
 		Error err = loader.write[i]->load_image(p_image, f, p_flags, p_scale);
 		if (err != OK) {
-			ERR_PRINT("Error loading image: " + p_file);
+			ERR_PRINT(vformat("Error loading image: '%s'.", p_file));
 		}
 
 		if (err != ERR_FILE_UNRECOGNIZED) {

core/io/ip.cpp

@@ -201,7 +201,7 @@ IPAddress IP::get_resolve_item_address(ResolverID p_id) const {
 	MutexLock lock(resolver->mutex);
 
 	if (resolver->queue[p_id].status.get() != IP::RESOLVER_STATUS_DONE) {
-		ERR_PRINT("Resolve of '" + resolver->queue[p_id].hostname + "'' didn't complete yet.");
+		ERR_PRINT(vformat("Resolve of '%s' didn't complete yet.", resolver->queue[p_id].hostname));
 		return IPAddress();
 	}
 
@@ -220,7 +220,7 @@ Array IP::get_resolve_item_addresses(ResolverID p_id) const {
 	MutexLock lock(resolver->mutex);
 
 	if (resolver->queue[p_id].status.get() != IP::RESOLVER_STATUS_DONE) {
-		ERR_PRINT("Resolve of '" + resolver->queue[p_id].hostname + "'' didn't complete yet.");
+		ERR_PRINT(vformat("Resolve of '%s' didn't complete yet.", resolver->queue[p_id].hostname));
 		return Array();
 	}
 

core/io/json.cpp

@@ -1402,7 +1402,7 @@ Error ResourceFormatSaverJSON::save(const Ref<Resource> &p_resource, const Strin
 	Error err;
 	Ref<FileAccess> file = FileAccess::open(p_path, FileAccess::WRITE, &err);
 
-	ERR_FAIL_COND_V_MSG(err, err, "Cannot save json '" + p_path + "'.");
+	ERR_FAIL_COND_V_MSG(err, err, vformat("Cannot save json '%s'.", p_path));
 
 	file->store_string(source);
 	if (file->get_error() != OK && file->get_error() != ERR_FILE_EOF) {

core/io/marshalls.cpp

@@ -698,9 +698,9 @@ Error decode_variant(Variant &r_variant, const uint8_t *p_buffer, int p_len, int
 						if (str == "script" && value.get_type() != Variant::NIL) {
 							ERR_FAIL_COND_V_MSG(value.get_type() != Variant::STRING, ERR_INVALID_DATA, "Invalid value for \"script\" property, expected script path as String.");
 							String path = value;
-							ERR_FAIL_COND_V_MSG(path.is_empty() || !path.begins_with("res://") || !ResourceLoader::exists(path, "Script"), ERR_INVALID_DATA, "Invalid script path: '" + path + "'.");
+							ERR_FAIL_COND_V_MSG(path.is_empty() || !path.begins_with("res://") || !ResourceLoader::exists(path, "Script"), ERR_INVALID_DATA, vformat("Invalid script path: '%s'.", path));
 							Ref<Script> script = ResourceLoader::load(path, "Script");
-							ERR_FAIL_COND_V_MSG(script.is_null(), ERR_INVALID_DATA, "Can't load script at path: '" + path + "'.");
+							ERR_FAIL_COND_V_MSG(script.is_null(), ERR_INVALID_DATA, vformat("Can't load script at path: '%s'.", path));
 							obj->set_script(script);
 						} else {
 							obj->set(str, value);
@@ -820,9 +820,9 @@ Error decode_variant(Variant &r_variant, const uint8_t *p_buffer, int p_len, int
 
 					builtin_type = Variant::OBJECT;
 					if (p_allow_objects) {
-						ERR_FAIL_COND_V_MSG(path.is_empty() || !path.begins_with("res://") || !ResourceLoader::exists(path, "Script"), ERR_INVALID_DATA, "Invalid script path: '" + path + "'.");
+						ERR_FAIL_COND_V_MSG(path.is_empty() || !path.begins_with("res://") || !ResourceLoader::exists(path, "Script"), ERR_INVALID_DATA, vformat("Invalid script path: '%s'.", path));
 						script = ResourceLoader::load(path, "Script");
-						ERR_FAIL_COND_V_MSG(script.is_null(), ERR_INVALID_DATA, "Can't load script at path: '" + path + "'.");
+						ERR_FAIL_COND_V_MSG(script.is_null(), ERR_INVALID_DATA, vformat("Can't load script at path: '%s'.", path));
 						class_name = script->get_instance_base_type();
 					} else {
 						class_name = EncodedObjectAsID::get_class_static();

core/io/pck_packer.cpp

@@ -84,7 +84,7 @@ Error PCKPacker::pck_start(const String &p_pck_path, int p_alignment, const Stri
 	enc_dir = p_encrypt_directory;
 
 	file = FileAccess::open(p_pck_path, FileAccess::WRITE);
-	ERR_FAIL_COND_V_MSG(file.is_null(), ERR_CANT_CREATE, "Can't open file to write: " + String(p_pck_path) + ".");
+	ERR_FAIL_COND_V_MSG(file.is_null(), ERR_CANT_CREATE, vformat("Can't open file to write: '%s'.", String(p_pck_path)));
 
 	alignment = p_alignment;
 

core/io/plist.cpp

@@ -450,7 +450,7 @@ PList::PList() {
 PList::PList(const String &p_string) {
 	String err_str;
 	bool ok = load_string(p_string, err_str);
-	ERR_FAIL_COND_MSG(!ok, "PList: " + err_str);
+	ERR_FAIL_COND_MSG(!ok, vformat("PList: %s.", err_str));
 }
 
 uint64_t PList::read_bplist_var_size_int(Ref<FileAccess> p_file, uint8_t p_size) {

core/io/remote_filesystem_client.cpp

@@ -96,7 +96,7 @@ Error RemoteFilesystemClient::_store_file(const String &p_path, const LocalVecto
 	}
 
 	Ref<FileAccess> f = FileAccess::open(full_path, FileAccess::WRITE);
-	ERR_FAIL_COND_V_MSG(f.is_null(), ERR_FILE_CANT_OPEN, "Unable to open file for writing to remote filesystem cache: " + p_path);
+	ERR_FAIL_COND_V_MSG(f.is_null(), ERR_FILE_CANT_OPEN, vformat("Unable to open file for writing to remote filesystem cache: '%s'.", p_path));
 	f->store_buffer(p_file.ptr(), p_file.size());
 	Error err = f->get_error();
 	if (err) {
@@ -115,10 +115,10 @@ Error RemoteFilesystemClient::_store_cache_file(const Vector<FileCache> &p_cache
 	String full_path = cache_path.path_join(FILES_CACHE_FILE);
 	String base_file_dir = full_path.get_base_dir();
 	Error err = DirAccess::make_dir_recursive_absolute(base_file_dir);
-	ERR_FAIL_COND_V_MSG(err != OK && err != ERR_ALREADY_EXISTS, err, "Unable to create base directory to store cache file: " + base_file_dir);
+	ERR_FAIL_COND_V_MSG(err != OK && err != ERR_ALREADY_EXISTS, err, vformat("Unable to create base directory to store cache file: '%s'.", base_file_dir));
 
 	Ref<FileAccess> f = FileAccess::open(full_path, FileAccess::WRITE);
-	ERR_FAIL_COND_V_MSG(f.is_null(), ERR_FILE_CANT_OPEN, "Unable to open the remote cache file for writing: " + full_path);
+	ERR_FAIL_COND_V_MSG(f.is_null(), ERR_FILE_CANT_OPEN, vformat("Unable to open the remote cache file for writing: '%s'.", full_path));
 	f->store_line(itos(FILESYSTEM_CACHE_VERSION));
 	for (int i = 0; i < p_cache.size(); i++) {
 		String l = p_cache[i].path + "::" + itos(p_cache[i].server_modified_time) + "::" + itos(p_cache[i].modified_time);
@@ -151,10 +151,10 @@ Error RemoteFilesystemClient::_synchronize_with_server(const String &p_host, int
 	tcp_client.instantiate();
 
 	IPAddress ip = p_host.is_valid_ip_address() ? IPAddress(p_host) : IP::get_singleton()->resolve_hostname(p_host);
-	ERR_FAIL_COND_V_MSG(!ip.is_valid(), ERR_INVALID_PARAMETER, "Unable to resolve remote filesystem server hostname: " + p_host);
+	ERR_FAIL_COND_V_MSG(!ip.is_valid(), ERR_INVALID_PARAMETER, vformat("Unable to resolve remote filesystem server hostname: '%s'.", p_host));
 	print_verbose(vformat("Remote Filesystem: Connecting to host %s, port %d.", ip, p_port));
 	Error err = tcp_client->connect_to_host(ip, p_port);
-	ERR_FAIL_COND_V_MSG(err != OK, err, "Unable to open connection to remote file server (" + String(p_host) + ", port " + itos(p_port) + ") failed.");
+	ERR_FAIL_COND_V_MSG(err != OK, err, vformat("Unable to open connection to remote file server (%s, port %d) failed.", String(p_host), p_port));
 
 	while (tcp_client->get_status() == StreamPeerTCP::STATUS_CONNECTING) {
 		tcp_client->poll();
@@ -162,7 +162,7 @@ Error RemoteFilesystemClient::_synchronize_with_server(const String &p_host, int
 	}
 
 	if (tcp_client->get_status() != StreamPeerTCP::STATUS_CONNECTED) {
-		ERR_FAIL_V_MSG(ERR_CANT_CONNECT, "Connection to remote file server (" + String(p_host) + ", port " + itos(p_port) + ") failed.");
+		ERR_FAIL_V_MSG(ERR_CANT_CONNECT, vformat("Connection to remote file server (%s, port %d) failed.", String(p_host), p_port));
 	}
 
 	// Connection OK, now send the current file state.
@@ -280,7 +280,7 @@ Error RemoteFilesystemClient::_synchronize_with_server(const String &p_host, int
 
 		err = tcp_client->get_data(file_buffer.ptr(), file_size);
 		if (err != OK) {
-			ERR_PRINT("Error retrieving file from remote filesystem: " + file);
+			ERR_PRINT(vformat("Error retrieving file from remote filesystem: '%s'.", file));
 			server_disconnected = true;
 		}
 

core/io/resource.cpp

@@ -76,7 +76,7 @@ void Resource::set_path(const String &p_path, bool p_take_over) {
 				existing->path_cache = String();
 				ResourceCache::resources.erase(p_path);
 			} else {
-				ERR_FAIL_MSG("Another resource is loaded from path '" + p_path + "' (possible cyclic resource inclusion).");
+				ERR_FAIL_MSG(vformat("Another resource is loaded from path '%s' (possible cyclic resource inclusion).", p_path));
 			}
 		}
 

core/io/resource_format_binary.cpp

@@ -411,7 +411,7 @@ Error ResourceLoaderBinary::parse_variant(Variant &r_v) {
 
 					//always use internal cache for loading internal resources
 					if (!internal_index_cache.has(path)) {
-						WARN_PRINT(String("Couldn't load resource (no cache): " + path).utf8().get_data());
+						WARN_PRINT(vformat("Couldn't load resource (no cache): %s.", path));
 						r_v = Variant();
 					} else {
 						r_v = internal_index_cache[path];
@@ -435,7 +435,7 @@ Error ResourceLoaderBinary::parse_variant(Variant &r_v) {
 					Ref<Resource> res = ResourceLoader::load(path, exttype, cache_mode_for_external);
 
 					if (res.is_null()) {
-						WARN_PRINT(String("Couldn't load resource: " + path).utf8().get_data());
+						WARN_PRINT(vformat("Couldn't load resource: %s.", path));
 					}
 					r_v = res;
 
@@ -458,7 +458,7 @@ Error ResourceLoaderBinary::parse_variant(Variant &r_v) {
 										ResourceLoader::notify_dependency_error(local_path, external_resources[erindex].path, external_resources[erindex].type);
 									} else {
 										error = ERR_FILE_MISSING_DEPENDENCIES;
-										ERR_FAIL_V_MSG(error, "Can't load dependency: " + external_resources[erindex].path + ".");
+										ERR_FAIL_V_MSG(error, vformat("Can't load dependency: '%s'.", external_resources[erindex].path));
 									}
 								}
 							} else {
@@ -704,7 +704,7 @@ Error ResourceLoaderBinary::load() {
 				ResourceLoader::notify_dependency_error(local_path, path, external_resources[i].type);
 			} else {
 				error = ERR_FILE_MISSING_DEPENDENCIES;
-				ERR_FAIL_V_MSG(error, "Can't load dependency: " + path + ".");
+				ERR_FAIL_V_MSG(error, vformat("Can't load dependency: '%s'.", path));
 			}
 		}
 	}
@@ -780,7 +780,7 @@ Error ResourceLoaderBinary::load() {
 						obj = missing_resource;
 					} else {
 						error = ERR_FILE_CORRUPT;
-						ERR_FAIL_V_MSG(ERR_FILE_CORRUPT, local_path + ":Resource of unrecognized type in file: " + t + ".");
+						ERR_FAIL_V_MSG(ERR_FILE_CORRUPT, vformat("'%s': Resource of unrecognized type in file: '%s'.", local_path, t));
 					}
 				}
 
@@ -789,7 +789,7 @@ Error ResourceLoaderBinary::load() {
 					String obj_class = obj->get_class();
 					error = ERR_FILE_CORRUPT;
 					memdelete(obj); //bye
-					ERR_FAIL_V_MSG(ERR_FILE_CORRUPT, local_path + ":Resource type in resource field not a resource, type is: " + obj_class + ".");
+					ERR_FAIL_V_MSG(ERR_FILE_CORRUPT, vformat("'%s': Resource type in resource field not a resource, type is: %s.", local_path, obj_class));
 				}
 
 				res = Ref<Resource>(r);
@@ -999,7 +999,7 @@ void ResourceLoaderBinary::open(Ref<FileAccess> p_f, bool p_no_resources, bool p
 		error = fac->open_after_magic(f);
 		if (error != OK) {
 			f.unref();
-			ERR_FAIL_MSG("Failed to open binary resource file: " + local_path + ".");
+			ERR_FAIL_MSG(vformat("Failed to open binary resource file: '%s'.", local_path));
 		}
 		f = fac;
 
@@ -1007,7 +1007,7 @@ void ResourceLoaderBinary::open(Ref<FileAccess> p_f, bool p_no_resources, bool p
 		// Not normal.
 		error = ERR_FILE_UNRECOGNIZED;
 		f.unref();
-		ERR_FAIL_MSG("Unrecognized binary resource file: " + local_path + ".");
+		ERR_FAIL_MSG(vformat("Unrecognized binary resource file: '%s'.", local_path));
 	}
 
 	bool big_endian = f->get_32();
@@ -1093,10 +1093,10 @@ void ResourceLoaderBinary::open(Ref<FileAccess> p_f, bool p_no_resources, bool p
 #ifdef TOOLS_ENABLED
 					// Silence a warning that can happen during the initial filesystem scan due to cache being regenerated.
 					if (ResourceLoader::get_resource_uid(res_path) != er.uid) {
-						WARN_PRINT(String(res_path + ": In external resource #" + itos(i) + ", invalid UID: " + ResourceUID::get_singleton()->id_to_text(er.uid) + " - using text path instead: " + er.path).utf8().get_data());
+						WARN_PRINT(vformat("'%s': In external resource #%d, invalid UID: '%s' - using text path instead: '%s'.", res_path, i, ResourceUID::get_singleton()->id_to_text(er.uid), er.path));
 					}
 #else
-					WARN_PRINT(String(res_path + ": In external resource #" + itos(i) + ", invalid UID: " + ResourceUID::get_singleton()->id_to_text(er.uid) + " - using text path instead: " + er.path).utf8().get_data());
+					WARN_PRINT(vformat("'%s': In external resource #%d, invalid UID: '%s' - using text path instead: '%s'.", res_path, i, ResourceUID::get_singleton()->id_to_text(er.uid), er.path));
 #endif
 				}
 			}
@@ -1120,7 +1120,7 @@ void ResourceLoaderBinary::open(Ref<FileAccess> p_f, bool p_no_resources, bool p
 	if (f->eof_reached()) {
 		error = ERR_FILE_CORRUPT;
 		f.unref();
-		ERR_FAIL_MSG("Premature end of file (EOF): " + local_path + ".");
+		ERR_FAIL_MSG(vformat("Premature end of file (EOF): '%s'.", local_path));
 	}
 }
 
@@ -1224,7 +1224,7 @@ Ref<Resource> ResourceFormatLoaderBinary::load(const String &p_path, const Strin
 	Error err;
 	Ref<FileAccess> f = FileAccess::open(p_path, FileAccess::READ, &err);
 
-	ERR_FAIL_COND_V_MSG(err != OK, Ref<Resource>(), "Cannot open file '" + p_path + "'.");
+	ERR_FAIL_COND_V_MSG(err != OK, Ref<Resource>(), vformat("Cannot open file '%s'.", p_path));
 
 	ResourceLoaderBinary loader;
 	switch (p_cache_mode) {
@@ -1301,7 +1301,7 @@ bool ResourceFormatLoaderBinary::handles_type(const String &p_type) const {
 
 void ResourceFormatLoaderBinary::get_dependencies(const String &p_path, List<String> *p_dependencies, bool p_add_types) {
 	Ref<FileAccess> f = FileAccess::open(p_path, FileAccess::READ);
-	ERR_FAIL_COND_MSG(f.is_null(), "Cannot open file '" + p_path + "'.");
+	ERR_FAIL_COND_MSG(f.is_null(), vformat("Cannot open file '%s'.", p_path));
 
 	ResourceLoaderBinary loader;
 	loader.local_path = ProjectSettings::get_singleton()->localize_path(p_path);
@@ -1311,7 +1311,7 @@ void ResourceFormatLoaderBinary::get_dependencies(const String &p_path, List<Str
 
 Error ResourceFormatLoaderBinary::rename_dependencies(const String &p_path, const HashMap<String, String> &p_map) {
 	Ref<FileAccess> f = FileAccess::open(p_path, FileAccess::READ);
-	ERR_FAIL_COND_V_MSG(f.is_null(), ERR_CANT_OPEN, "Cannot open file '" + p_path + "'.");
+	ERR_FAIL_COND_V_MSG(f.is_null(), ERR_CANT_OPEN, vformat("Cannot open file '%s'.", p_path));
 
 	Ref<FileAccess> fw;
 
@@ -1324,23 +1324,23 @@ Error ResourceFormatLoaderBinary::rename_dependencies(const String &p_path, cons
 		Ref<FileAccessCompressed> fac;
 		fac.instantiate();
 		Error err = fac->open_after_magic(f);
-		ERR_FAIL_COND_V_MSG(err != OK, err, "Cannot open file '" + p_path + "'.");
+		ERR_FAIL_COND_V_MSG(err != OK, err, vformat("Cannot open file '%s'.", p_path));
 		f = fac;
 
 		Ref<FileAccessCompressed> facw;
 		facw.instantiate();
 		facw->configure("RSCC");
 		err = facw->open_internal(p_path + ".depren", FileAccess::WRITE);
-		ERR_FAIL_COND_V_MSG(err, ERR_FILE_CORRUPT, "Cannot create file '" + p_path + ".depren'.");
+		ERR_FAIL_COND_V_MSG(err, ERR_FILE_CORRUPT, vformat("Cannot create file '%s.depren'.", p_path));
 
 		fw = facw;
 
 	} else if (header[0] != 'R' || header[1] != 'S' || header[2] != 'R' || header[3] != 'C') {
 		// Not normal.
-		ERR_FAIL_V_MSG(ERR_FILE_UNRECOGNIZED, "Unrecognized binary resource file '" + local_path + "'.");
+		ERR_FAIL_V_MSG(ERR_FILE_UNRECOGNIZED, vformat("Unrecognized binary resource file '%s'.", local_path));
 	} else {
 		fw = FileAccess::open(p_path + ".depren", FileAccess::WRITE);
-		ERR_FAIL_COND_V_MSG(fw.is_null(), ERR_CANT_CREATE, "Cannot create file '" + p_path + ".depren'.");
+		ERR_FAIL_COND_V_MSG(fw.is_null(), ERR_CANT_CREATE, vformat("Cannot create file '%s.depren'.", p_path));
 
 		uint8_t magic[4] = { 'R', 'S', 'R', 'C' };
 		fw->store_buffer(magic, 4);
@@ -1372,12 +1372,12 @@ Error ResourceFormatLoaderBinary::rename_dependencies(const String &p_path, cons
 
 		// Use the old approach.
 
-		WARN_PRINT("This file is old, so it can't refactor dependencies, opening and resaving '" + p_path + "'.");
+		WARN_PRINT(vformat("This file is old, so it can't refactor dependencies, opening and resaving '%s'.", p_path));
 
 		Error err;
 		f = FileAccess::open(p_path, FileAccess::READ, &err);
 
-		ERR_FAIL_COND_V_MSG(err != OK, ERR_FILE_CANT_OPEN, "Cannot open file '" + p_path + "'.");
+		ERR_FAIL_COND_V_MSG(err != OK, ERR_FILE_CANT_OPEN, vformat("Cannot open file '%s'.", p_path));
 
 		ResourceLoaderBinary loader;
 		loader.local_path = ProjectSettings::get_singleton()->localize_path(p_path);
@@ -1523,7 +1523,7 @@ Error ResourceFormatLoaderBinary::rename_dependencies(const String &p_path, cons
 
 void ResourceFormatLoaderBinary::get_classes_used(const String &p_path, HashSet<StringName> *r_classes) {
 	Ref<FileAccess> f = FileAccess::open(p_path, FileAccess::READ);
-	ERR_FAIL_COND_MSG(f.is_null(), "Cannot open file '" + p_path + "'.");
+	ERR_FAIL_COND_MSG(f.is_null(), vformat("Cannot open file '%s'.", p_path));
 
 	ResourceLoaderBinary loader;
 	loader.local_path = ProjectSettings::get_singleton()->localize_path(p_path);
@@ -2027,7 +2027,7 @@ void ResourceFormatSaverBinaryInstance::_find_resources(const Variant &p_variant
 
 			if (!p_main && (!bundle_resources) && !res->is_built_in()) {
 				if (res->get_path() == path) {
-					ERR_PRINT("Circular reference to resource being saved found: '" + local_path + "' will be null next time it's loaded.");
+					ERR_PRINT(vformat("Circular reference to resource being saved found: '%s' will be null next time it's loaded.", local_path));
 					return;
 				}
 				int idx = external_resources.size();
@@ -2153,7 +2153,7 @@ Error ResourceFormatSaverBinaryInstance::save(const String &p_path, const Ref<Re
 		f = FileAccess::open(p_path, FileAccess::WRITE, &err);
 	}
 
-	ERR_FAIL_COND_V_MSG(err != OK, err, "Cannot create file '" + p_path + "'.");
+	ERR_FAIL_COND_V_MSG(err != OK, err, vformat("Cannot create file '%s'.", p_path));
 
 	relative_paths = p_flags & ResourceSaver::FLAG_RELATIVE_PATHS;
 	skip_editor = p_flags & ResourceSaver::FLAG_OMIT_EDITOR_PROPERTIES;
@@ -2384,7 +2384,7 @@ Error ResourceFormatSaverBinaryInstance::save(const String &p_path, const Ref<Re
 
 Error ResourceFormatSaverBinaryInstance::set_uid(const String &p_path, ResourceUID::ID p_uid) {
 	Ref<FileAccess> f = FileAccess::open(p_path, FileAccess::READ);
-	ERR_FAIL_COND_V_MSG(f.is_null(), ERR_CANT_OPEN, "Cannot open file '" + p_path + "'.");
+	ERR_FAIL_COND_V_MSG(f.is_null(), ERR_CANT_OPEN, vformat("Cannot open file '%s'.", p_path));
 
 	Ref<FileAccess> fw;
 
@@ -2397,14 +2397,14 @@ Error ResourceFormatSaverBinaryInstance::set_uid(const String &p_path, ResourceU
 		Ref<FileAccessCompressed> fac;
 		fac.instantiate();
 		Error err = fac->open_after_magic(f);
-		ERR_FAIL_COND_V_MSG(err != OK, err, "Cannot open file '" + p_path + "'.");
+		ERR_FAIL_COND_V_MSG(err != OK, err, vformat("Cannot open file '%s'.", p_path));
 		f = fac;
 
 		Ref<FileAccessCompressed> facw;
 		facw.instantiate();
 		facw->configure("RSCC");
 		err = facw->open_internal(p_path + ".uidren", FileAccess::WRITE);
-		ERR_FAIL_COND_V_MSG(err, ERR_FILE_CORRUPT, "Cannot create file '" + p_path + ".uidren'.");
+		ERR_FAIL_COND_V_MSG(err, ERR_FILE_CORRUPT, vformat("Cannot create file '%s.uidren'.", p_path));
 
 		fw = facw;
 
@@ -2413,7 +2413,7 @@ Error ResourceFormatSaverBinaryInstance::set_uid(const String &p_path, ResourceU
 		return ERR_FILE_UNRECOGNIZED;
 	} else {
 		fw = FileAccess::open(p_path + ".uidren", FileAccess::WRITE);
-		ERR_FAIL_COND_V_MSG(fw.is_null(), ERR_CANT_CREATE, "Cannot create file '" + p_path + ".uidren'.");
+		ERR_FAIL_COND_V_MSG(fw.is_null(), ERR_CANT_CREATE, vformat("Cannot create file '%s.uidren'.", p_path));
 
 		uint8_t magich[4] = { 'R', 'S', 'R', 'C' };
 		fw->store_buffer(magich, 4);
@@ -2444,7 +2444,7 @@ Error ResourceFormatSaverBinaryInstance::set_uid(const String &p_path, ResourceU
 
 		// Use the old approach.
 
-		WARN_PRINT("This file is old, so it does not support UIDs, opening and resaving '" + p_path + "'.");
+		WARN_PRINT(vformat("This file is old, so it does not support UIDs, opening and resaving '%s'.", p_path));
 		return ERR_UNAVAILABLE;
 	}
 

core/io/resource_importer.cpp

@@ -75,7 +75,7 @@ Error ResourceFormatImporter::_get_path_and_type(const String &p_path, PathAndTy
 		if (err == ERR_FILE_EOF) {
 			return OK;
 		} else if (err != OK) {
-			ERR_PRINT("ResourceFormatImporter::load - " + p_path + ".import:" + itos(lines) + " error: " + error_text);
+			ERR_PRINT(vformat("ResourceFormatImporter::load - %s.import:%d error: %s.", p_path, lines, error_text));
 			return err;
 		}
 
@@ -335,7 +335,7 @@ void ResourceFormatImporter::get_internal_resource_path_list(const String &p_pat
 		if (err == ERR_FILE_EOF) {
 			return;
 		} else if (err != OK) {
-			ERR_PRINT("ResourceFormatImporter::get_internal_resource_path_list - " + p_path + ".import:" + itos(lines) + " error: " + error_text);
+			ERR_PRINT(vformat("ResourceFormatImporter::get_internal_resource_path_list - %s.import:%d error: %s.", p_path, lines, error_text));
 			return;
 		}
 

core/io/resource_loader.cpp

@@ -162,7 +162,7 @@ Ref<Resource> ResourceFormatLoader::load(const String &p_path, const String &p_o
 		}
 	}
 
-	ERR_FAIL_V_MSG(Ref<Resource>(), "Failed to load resource '" + p_path + "'. ResourceFormatLoader::load was not implemented for this resource type.");
+	ERR_FAIL_V_MSG(Ref<Resource>(), vformat("Failed to load resource '%s'. ResourceFormatLoader::load was not implemented for this resource type.", p_path));
 }
 
 void ResourceFormatLoader::get_dependencies(const String &p_path, List<String> *p_dependencies, bool p_add_types) {
@@ -1163,7 +1163,7 @@ String ResourceLoader::_path_remap(const String &p_path, bool *r_translation_rem
 		// An extra remap may still be necessary afterwards due to the text -> binary converter on export.
 
 		String locale = TranslationServer::get_singleton()->get_locale();
-		ERR_FAIL_COND_V_MSG(locale.length() < 2, p_path, "Could not remap path '" + p_path + "' for translation as configured locale '" + locale + "' is invalid.");
+		ERR_FAIL_COND_V_MSG(locale.length() < 2, p_path, vformat("Could not remap path '%s' for translation as configured locale '%s' is invalid.", p_path, locale));
 
 		Vector<String> &res_remaps = *translation_remaps.getptr(new_path);
 
@@ -1222,7 +1222,7 @@ String ResourceLoader::_path_remap(const String &p_path, bool *r_translation_rem
 					if (err == ERR_FILE_EOF) {
 						break;
 					} else if (err != OK) {
-						ERR_PRINT("Parse error: " + p_path + ".remap:" + itos(lines) + " error: " + error_text + ".");
+						ERR_PRINT(vformat("Parse error: %s.remap:%d error: %s.", p_path, lines, error_text));
 						break;
 					}
 

core/io/resource_saver.cpp

@@ -98,7 +98,7 @@ void ResourceFormatSaver::_bind_methods() {
 }
 
 Error ResourceSaver::save(const Ref<Resource> &p_resource, const String &p_path, uint32_t p_flags) {
-	ERR_FAIL_COND_V_MSG(p_resource.is_null(), ERR_INVALID_PARAMETER, "Can't save empty resource to path '" + p_path + "'.");
+	ERR_FAIL_COND_V_MSG(p_resource.is_null(), ERR_INVALID_PARAMETER, vformat("Can't save empty resource to path '%s'.", p_path));
 	String path = p_path;
 	if (path.is_empty()) {
 		path = p_resource->get_path();

core/io/translation_loader_po.cpp

@@ -169,14 +169,14 @@ Ref<Resource> TranslationLoaderPO::load_translation(Ref<FileAccess> f, Error *r_
 			// If we reached last line and it's not a content line, break, otherwise let processing that last loop
 			if (is_eof && l.is_empty()) {
 				if (status == STATUS_READING_ID || status == STATUS_READING_CONTEXT || (status == STATUS_READING_PLURAL && plural_index != plural_forms - 1)) {
-					ERR_FAIL_V_MSG(Ref<Resource>(), "Unexpected EOF while reading PO file at: " + path + ":" + itos(line));
+					ERR_FAIL_V_MSG(Ref<Resource>(), vformat("Unexpected EOF while reading PO file at: %s:%d.", path, line));
 				} else {
 					break;
 				}
 			}
 
 			if (l.begins_with("msgctxt")) {
-				ERR_FAIL_COND_V_MSG(status != STATUS_READING_STRING && status != STATUS_READING_PLURAL, Ref<Resource>(), "Unexpected 'msgctxt', was expecting 'msgid_plural' or 'msgstr' before 'msgctxt' while parsing: " + path + ":" + itos(line));
+				ERR_FAIL_COND_V_MSG(status != STATUS_READING_STRING && status != STATUS_READING_PLURAL, Ref<Resource>(), vformat("Unexpected 'msgctxt', was expecting 'msgid_plural' or 'msgstr' before 'msgctxt' while parsing: %s:%d.", path, line));
 
 				// In PO file, "msgctxt" appears before "msgid". If we encounter a "msgctxt", we add what we have read
 				// and set "entered_context" to true to prevent adding twice.
@@ -184,7 +184,7 @@ Ref<Resource> TranslationLoaderPO::load_translation(Ref<FileAccess> f, Error *r_
 					if (status == STATUS_READING_STRING) {
 						translation->add_message(msg_id, msg_str, msg_context);
 					} else if (status == STATUS_READING_PLURAL) {
-						ERR_FAIL_COND_V_MSG(plural_index != plural_forms - 1, Ref<Resource>(), "Number of 'msgstr[]' doesn't match with number of plural forms: " + path + ":" + itos(line));
+						ERR_FAIL_COND_V_MSG(plural_index != plural_forms - 1, Ref<Resource>(), vformat("Number of 'msgstr[]' doesn't match with number of plural forms: %s:%d.", path, line));
 						translation->add_plural_message(msg_id, msgs_plural, msg_context);
 					}
 				}
@@ -196,9 +196,9 @@ Ref<Resource> TranslationLoaderPO::load_translation(Ref<FileAccess> f, Error *r_
 
 			if (l.begins_with("msgid_plural")) {
 				if (plural_forms == 0) {
-					ERR_FAIL_V_MSG(Ref<Resource>(), "PO file uses 'msgid_plural' but 'Plural-Forms' is invalid or missing in header: " + path + ":" + itos(line));
+					ERR_FAIL_V_MSG(Ref<Resource>(), vformat("PO file uses 'msgid_plural' but 'Plural-Forms' is invalid or missing in header: %s:%d.", path, line));
 				} else if (status != STATUS_READING_ID) {
-					ERR_FAIL_V_MSG(Ref<Resource>(), "Unexpected 'msgid_plural', was expecting 'msgid' before 'msgid_plural' while parsing: " + path + ":" + itos(line));
+					ERR_FAIL_V_MSG(Ref<Resource>(), vformat("Unexpected 'msgid_plural', was expecting 'msgid' before 'msgid_plural' while parsing: %s:%d.", path, line));
 				}
 				// We don't record the message in "msgid_plural" itself as tr_n(), TTRN(), RTRN() interfaces provide the plural string already.
 				// We just have to reset variables related to plurals for "msgstr[]" later on.
@@ -208,14 +208,14 @@ Ref<Resource> TranslationLoaderPO::load_translation(Ref<FileAccess> f, Error *r_
 				msgs_plural.resize(plural_forms);
 				status = STATUS_READING_PLURAL;
 			} else if (l.begins_with("msgid")) {
-				ERR_FAIL_COND_V_MSG(status == STATUS_READING_ID, Ref<Resource>(), "Unexpected 'msgid', was expecting 'msgstr' while parsing: " + path + ":" + itos(line));
+				ERR_FAIL_COND_V_MSG(status == STATUS_READING_ID, Ref<Resource>(), vformat("Unexpected 'msgid', was expecting 'msgstr' while parsing: %s:%d.", path, line));
 
 				if (!msg_id.is_empty()) {
 					if (!skip_this && !entered_context) {
 						if (status == STATUS_READING_STRING) {
 							translation->add_message(msg_id, msg_str, msg_context);
 						} else if (status == STATUS_READING_PLURAL) {
-							ERR_FAIL_COND_V_MSG(plural_index != plural_forms - 1, Ref<Resource>(), "Number of 'msgstr[]' doesn't match with number of plural forms: " + path + ":" + itos(line));
+							ERR_FAIL_COND_V_MSG(plural_index != plural_forms - 1, Ref<Resource>(), vformat("Number of 'msgstr[]' doesn't match with number of plural forms: %s:%d.", path, line));
 							translation->add_plural_message(msg_id, msgs_plural, msg_context);
 						}
 					}
@@ -244,11 +244,11 @@ Ref<Resource> TranslationLoaderPO::load_translation(Ref<FileAccess> f, Error *r_
 			}
 
 			if (l.begins_with("msgstr[")) {
-				ERR_FAIL_COND_V_MSG(status != STATUS_READING_PLURAL, Ref<Resource>(), "Unexpected 'msgstr[]', was expecting 'msgid_plural' before 'msgstr[]' while parsing: " + path + ":" + itos(line));
+				ERR_FAIL_COND_V_MSG(status != STATUS_READING_PLURAL, Ref<Resource>(), vformat("Unexpected 'msgstr[]', was expecting 'msgid_plural' before 'msgstr[]' while parsing: %s:%d.", path, line));
 				plural_index++; // Increment to add to the next slot in vector msgs_plural.
 				l = l.substr(9, l.length()).strip_edges();
 			} else if (l.begins_with("msgstr")) {
-				ERR_FAIL_COND_V_MSG(status != STATUS_READING_ID, Ref<Resource>(), "Unexpected 'msgstr', was expecting 'msgid' before 'msgstr' while parsing: " + path + ":" + itos(line));
+				ERR_FAIL_COND_V_MSG(status != STATUS_READING_ID, Ref<Resource>(), vformat("Unexpected 'msgstr', was expecting 'msgid' before 'msgstr' while parsing: %s:%d.", path, line));
 				l = l.substr(6, l.length()).strip_edges();
 				status = STATUS_READING_STRING;
 			}
@@ -261,7 +261,7 @@ Ref<Resource> TranslationLoaderPO::load_translation(Ref<FileAccess> f, Error *r_
 				continue; // Nothing to read or comment.
 			}
 
-			ERR_FAIL_COND_V_MSG(!l.begins_with("\"") || status == STATUS_NONE, Ref<Resource>(), "Invalid line '" + l + "' while parsing: " + path + ":" + itos(line));
+			ERR_FAIL_COND_V_MSG(!l.begins_with("\"") || status == STATUS_NONE, Ref<Resource>(), vformat("Invalid line '%s' while parsing: %s:%d.", l, path, line));
 
 			l = l.substr(1, l.length());
 			// Find final quote, ignoring escaped ones (\").
@@ -283,7 +283,7 @@ Ref<Resource> TranslationLoaderPO::load_translation(Ref<FileAccess> f, Error *r_
 				escape_next = false;
 			}
 
-			ERR_FAIL_COND_V_MSG(end_pos == -1, Ref<Resource>(), "Expected '\"' at end of message while parsing: " + path + ":" + itos(line));
+			ERR_FAIL_COND_V_MSG(end_pos == -1, Ref<Resource>(), vformat("Expected '\"' at end of message while parsing: %s:%d.", path, line));
 
 			l = l.substr(0, end_pos);
 			l = l.c_unescape();
@@ -295,7 +295,7 @@ Ref<Resource> TranslationLoaderPO::load_translation(Ref<FileAccess> f, Error *r_
 			} else if (status == STATUS_READING_CONTEXT) {
 				msg_context += l;
 			} else if (status == STATUS_READING_PLURAL && plural_index >= 0) {
-				ERR_FAIL_COND_V_MSG(plural_index >= plural_forms, Ref<Resource>(), "Unexpected plural form while parsing: " + path + ":" + itos(line));
+				ERR_FAIL_COND_V_MSG(plural_index >= plural_forms, Ref<Resource>(), vformat("Unexpected plural form while parsing: %s:%d.", path, line));
 				msgs_plural.write[plural_index] = msgs_plural[plural_index] + l;
 			}
 
@@ -313,13 +313,13 @@ Ref<Resource> TranslationLoaderPO::load_translation(Ref<FileAccess> f, Error *r_
 			}
 		} else if (status == STATUS_READING_PLURAL) {
 			if (!skip_this && !msg_id.is_empty()) {
-				ERR_FAIL_COND_V_MSG(plural_index != plural_forms - 1, Ref<Resource>(), "Number of 'msgstr[]' doesn't match with number of plural forms: " + path + ":" + itos(line));
+				ERR_FAIL_COND_V_MSG(plural_index != plural_forms - 1, Ref<Resource>(), vformat("Number of 'msgstr[]' doesn't match with number of plural forms: %s:%d.", path, line));
 				translation->add_plural_message(msg_id, msgs_plural, msg_context);
 			}
 		}
 	}
 
-	ERR_FAIL_COND_V_MSG(config.is_empty(), Ref<Resource>(), "No config found in file: " + path + ".");
+	ERR_FAIL_COND_V_MSG(config.is_empty(), Ref<Resource>(), vformat("No config found in file: '%s'.", path));
 
 	Vector<String> configs = config.split("\n");
 	for (int i = 0; i < configs.size(); i++) {
@@ -349,7 +349,7 @@ Ref<Resource> TranslationLoaderPO::load(const String &p_path, const String &p_or
 	}
 
 	Ref<FileAccess> f = FileAccess::open(p_path, FileAccess::READ);
-	ERR_FAIL_COND_V_MSG(f.is_null(), Ref<Resource>(), "Cannot open file '" + p_path + "'.");
+	ERR_FAIL_COND_V_MSG(f.is_null(), Ref<Resource>(), vformat("Cannot open file '%s'.", p_path));
 
 	return load_translation(f, r_error);
 }

core/io/xml_parser.cpp

@@ -429,7 +429,7 @@ String XMLParser::get_named_attribute_value(const String &p_name) const {
 		}
 	}
 
-	ERR_FAIL_COND_V_MSG(idx < 0, "", "Attribute not found: " + p_name + ".");
+	ERR_FAIL_COND_V_MSG(idx < 0, "", vformat("Attribute not found: '%s'.", p_name));
 
 	return attributes[idx].value;
 }
@@ -493,7 +493,7 @@ Error XMLParser::open(const String &p_path) {
 	Error err;
 	Ref<FileAccess> file = FileAccess::open(p_path, FileAccess::READ, &err);
 
-	ERR_FAIL_COND_V_MSG(err != OK, err, "Cannot open file '" + p_path + "'.");
+	ERR_FAIL_COND_V_MSG(err != OK, err, vformat("Cannot open file '%s'.", p_path));
 
 	length = file->get_length();
 	ERR_FAIL_COND_V(length < 1, ERR_FILE_CORRUPT);

core/math/expression.cpp

@@ -1491,7 +1491,7 @@ Error Expression::parse(const String &p_expression, const Vector<String> &p_inpu
 }
 
 Variant Expression::execute(const Array &p_inputs, Object *p_base, bool p_show_error, bool p_const_calls_only) {
-	ERR_FAIL_COND_V_MSG(error_set, Variant(), "There was previously a parse error: " + error_str + ".");
+	ERR_FAIL_COND_V_MSG(error_set, Variant(), vformat("There was previously a parse error: %s.", error_str));
 
 	execution_error = false;
 	Variant output;

core/object/class_db.cpp

@@ -352,7 +352,7 @@ StringName ClassDB::get_compatibility_remapped_class(const StringName &p_class)
 
 StringName ClassDB::_get_parent_class(const StringName &p_class) {
 	ClassInfo *ti = classes.getptr(p_class);
-	ERR_FAIL_NULL_V_MSG(ti, StringName(), "Cannot get class '" + String(p_class) + "'.");
+	ERR_FAIL_NULL_V_MSG(ti, StringName(), vformat("Cannot get class '%s'.", String(p_class)));
 	return ti->inherits;
 }
 
@@ -367,7 +367,7 @@ ClassDB::APIType ClassDB::get_api_type(const StringName &p_class) {
 
 	ClassInfo *ti = classes.getptr(p_class);
 
-	ERR_FAIL_NULL_V_MSG(ti, API_NONE, "Cannot get class '" + String(p_class) + "'.");
+	ERR_FAIL_NULL_V_MSG(ti, API_NONE, vformat("Cannot get class '%s'.", String(p_class)));
 	return ti->api;
 }
 
@@ -390,7 +390,7 @@ uint32_t ClassDB::get_api_hash(APIType p_api) {
 
 	for (const StringName &E : class_list) {
 		ClassInfo *t = classes.getptr(E);
-		ERR_FAIL_NULL_V_MSG(t, 0, "Cannot get class '" + String(E) + "'.");
+		ERR_FAIL_NULL_V_MSG(t, 0, vformat("Cannot get class '%s'.", String(E)));
 		if (t->api != p_api || !t->exposed) {
 			continue;
 		}
@@ -547,14 +547,14 @@ Object *ClassDB::_instantiate_internal(const StringName &p_class, bool p_require
 				ti = classes.getptr(compat_classes[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->creation_func, nullptr, "Class '" + String(p_class) + "' or its base class cannot be instantiated.");
+		ERR_FAIL_NULL_V_MSG(ti, nullptr, vformat("Cannot get class '%s'.", String(p_class)));
+		ERR_FAIL_COND_V_MSG(ti->disabled, nullptr, vformat("Class '%s' is disabled.", String(p_class)));
+		ERR_FAIL_NULL_V_MSG(ti->creation_func, nullptr, vformat("Class '%s' or its base class cannot be instantiated.", String(p_class)));
 	}
 
 #ifdef TOOLS_ENABLED
 	if ((ti->api == API_EDITOR || ti->api == API_EDITOR_EXTENSION) && !Engine::get_singleton()->is_editor_hint()) {
-		ERR_PRINT("Class '" + String(p_class) + "' can only be instantiated by editor.");
+		ERR_PRINT(vformat("Class '%s' can only be instantiated by editor.", String(p_class)));
 		return nullptr;
 	}
 #endif
@@ -653,8 +653,8 @@ ObjectGDExtension *ClassDB::get_placeholder_extension(const StringName &p_class)
 				ti = classes.getptr(compat_classes[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, nullptr, vformat("Cannot get class '%s'.", String(p_class)));
+		ERR_FAIL_COND_V_MSG(ti->disabled, nullptr, vformat("Class '%s' is disabled.", String(p_class)));
 	}
 
 	// Make a "fake" extension to act as a placeholder.
@@ -734,9 +734,9 @@ void ClassDB::set_object_extension_instance(Object *p_object, const StringName &
 				ti = classes.getptr(compat_classes[p_class]);
 			}
 		}
-		ERR_FAIL_NULL_MSG(ti, "Cannot get class '" + String(p_class) + "'.");
-		ERR_FAIL_COND_MSG(ti->disabled, "Class '" + String(p_class) + "' is disabled.");
-		ERR_FAIL_NULL_MSG(ti->gdextension, "Class '" + String(p_class) + "' has no native extension.");
+		ERR_FAIL_NULL_MSG(ti, vformat("Cannot get class '%s'.", String(p_class)));
+		ERR_FAIL_COND_MSG(ti->disabled, vformat("Class '%s' is disabled.", String(p_class)));
+		ERR_FAIL_NULL_MSG(ti->gdextension, vformat("Class '%s' has no native extension.", String(p_class)));
 	}
 
 	p_object->_extension = ti->gdextension;
@@ -755,7 +755,7 @@ bool ClassDB::can_instantiate(const StringName &p_class) {
 	ClassInfo *ti = classes.getptr(p_class);
 	if (!ti) {
 		if (!ScriptServer::is_global_class(p_class)) {
-			ERR_FAIL_V_MSG(false, "Cannot get class '" + String(p_class) + "'.");
+			ERR_FAIL_V_MSG(false, vformat("Cannot get class '%s'.", String(p_class)));
 		}
 		String path = ScriptServer::get_global_class_path(p_class);
 		Ref<Script> scr = ResourceLoader::load(path);
@@ -775,7 +775,7 @@ bool ClassDB::is_abstract(const StringName &p_class) {
 	ClassInfo *ti = classes.getptr(p_class);
 	if (!ti) {
 		if (!ScriptServer::is_global_class(p_class)) {
-			ERR_FAIL_V_MSG(false, "Cannot get class '" + String(p_class) + "'.");
+			ERR_FAIL_V_MSG(false, vformat("Cannot get class '%s'.", String(p_class)));
 		}
 		String path = ScriptServer::get_global_class_path(p_class);
 		Ref<Script> scr = ResourceLoader::load(path);
@@ -801,7 +801,7 @@ bool ClassDB::is_virtual(const StringName &p_class) {
 	ClassInfo *ti = classes.getptr(p_class);
 	if (!ti) {
 		if (!ScriptServer::is_global_class(p_class)) {
-			ERR_FAIL_V_MSG(false, "Cannot get class '" + String(p_class) + "'.");
+			ERR_FAIL_V_MSG(false, vformat("Cannot get class '%s'.", String(p_class)));
 		}
 		String path = ScriptServer::get_global_class_path(p_class);
 		Ref<Script> scr = ResourceLoader::load(path);
@@ -820,7 +820,7 @@ void ClassDB::_add_class2(const StringName &p_class, const StringName &p_inherit
 
 	const StringName &name = p_class;
 
-	ERR_FAIL_COND_MSG(classes.has(name), "Class '" + String(p_class) + "' already exists.");
+	ERR_FAIL_COND_MSG(classes.has(name), vformat("Class '%s' already exists.", String(p_class)));
 
 	classes[name] = ClassInfo();
 	ClassInfo &ti = classes[name];
@@ -1328,7 +1328,7 @@ void ClassDB::add_signal(const StringName &p_class, const MethodInfo &p_signal)
 #ifdef DEBUG_METHODS_ENABLED
 	ClassInfo *check = type;
 	while (check) {
-		ERR_FAIL_COND_MSG(check->signal_map.has(sname), "Class '" + String(p_class) + "' already has signal '" + String(sname) + "'.");
+		ERR_FAIL_COND_MSG(check->signal_map.has(sname), vformat("Class '%s' already has signal '%s'.", String(p_class), String(sname)));
 		check = check->inherits_ptr;
 	}
 #endif
@@ -1442,10 +1442,10 @@ void ClassDB::add_property(const StringName &p_class, const PropertyInfo &p_pinf
 		mb_set = get_method(p_class, p_setter);
 #ifdef DEBUG_METHODS_ENABLED
 
-		ERR_FAIL_NULL_MSG(mb_set, "Invalid setter '" + p_class + "::" + p_setter + "' for property '" + p_pinfo.name + "'.");
+		ERR_FAIL_NULL_MSG(mb_set, vformat("Invalid setter '%s::%s' for property '%s'.", p_class, p_setter, p_pinfo.name));
 
 		int exp_args = 1 + (p_index >= 0 ? 1 : 0);
-		ERR_FAIL_COND_MSG(mb_set->get_argument_count() != exp_args, "Invalid function for setter '" + p_class + "::" + p_setter + " for property '" + p_pinfo.name + "'.");
+		ERR_FAIL_COND_MSG(mb_set->get_argument_count() != exp_args, vformat("Invalid function for setter '%s::%s' for property '%s'.", p_class, p_setter, p_pinfo.name));
 #endif
 	}
 
@@ -1454,15 +1454,15 @@ void ClassDB::add_property(const StringName &p_class, const PropertyInfo &p_pinf
 		mb_get = get_method(p_class, p_getter);
 #ifdef DEBUG_METHODS_ENABLED
 
-		ERR_FAIL_NULL_MSG(mb_get, "Invalid getter '" + p_class + "::" + p_getter + "' for property '" + p_pinfo.name + "'.");
+		ERR_FAIL_NULL_MSG(mb_get, vformat("Invalid getter '%s::%s' for property '%s'.", p_class, p_getter, p_pinfo.name));
 
 		int exp_args = 0 + (p_index >= 0 ? 1 : 0);
-		ERR_FAIL_COND_MSG(mb_get->get_argument_count() != exp_args, "Invalid function for getter '" + p_class + "::" + p_getter + "' for property: '" + p_pinfo.name + "'.");
+		ERR_FAIL_COND_MSG(mb_get->get_argument_count() != exp_args, vformat("Invalid function for getter '%s::%s' for property '%s'.", p_class, p_getter, p_pinfo.name));
 #endif
 	}
 
 #ifdef DEBUG_METHODS_ENABLED
-	ERR_FAIL_COND_MSG(type->property_setget.has(p_pinfo.name), "Object '" + p_class + "' already has property '" + p_pinfo.name + "'.");
+	ERR_FAIL_COND_MSG(type->property_setget.has(p_pinfo.name), vformat("Object '%s' already has property '%s'.", p_class, p_pinfo.name));
 #endif
 
 	OBJTYPE_WLOCK
@@ -1847,7 +1847,7 @@ void ClassDB::_bind_method_custom(const StringName &p_class, MethodBind *p_metho
 
 	ClassInfo *type = classes.getptr(p_class);
 	if (!type) {
-		ERR_FAIL_MSG("Couldn't bind custom method '" + p_method->get_name() + "' for instance '" + p_class + "'.");
+		ERR_FAIL_MSG(vformat("Couldn't bind custom method '%s' for instance '%s'.", p_method->get_name(), p_class));
 	}
 
 	if (p_compatibility) {
@@ -1857,7 +1857,7 @@ void ClassDB::_bind_method_custom(const StringName &p_class, MethodBind *p_metho
 
 	if (type->method_map.has(p_method->get_name())) {
 		// overloading not supported
-		ERR_FAIL_MSG("Method already bound '" + p_class + "::" + p_method->get_name() + "'.");
+		ERR_FAIL_MSG(vformat("Method already bound '%s::%s'.", p_class, p_method->get_name()));
 	}
 
 #ifdef DEBUG_METHODS_ENABLED
@@ -1888,7 +1888,7 @@ MethodBind *ClassDB::_bind_vararg_method(MethodBind *p_bind, const StringName &p
 	if (type->method_map.has(p_name)) {
 		memdelete(bind);
 		// Overloading not supported
-		ERR_FAIL_V_MSG(nullptr, "Method already bound: " + instance_type + "::" + p_name + ".");
+		ERR_FAIL_V_MSG(nullptr, vformat("Method already bound: '%s::%s'.", instance_type, p_name));
 	}
 	type->method_map[p_name] = bind;
 #ifdef DEBUG_METHODS_ENABLED
@@ -1916,26 +1916,26 @@ MethodBind *ClassDB::bind_methodfi(uint32_t p_flags, MethodBind *p_bind, bool p_
 
 #ifdef DEBUG_ENABLED
 
-	ERR_FAIL_COND_V_MSG(!p_compatibility && has_method(instance_type, mdname), nullptr, "Class " + String(instance_type) + " already has a method " + String(mdname) + ".");
+	ERR_FAIL_COND_V_MSG(!p_compatibility && has_method(instance_type, mdname), nullptr, vformat("Class '%s' already has a method '%s'.", String(instance_type), String(mdname)));
 #endif
 
 	ClassInfo *type = classes.getptr(instance_type);
 	if (!type) {
 		memdelete(p_bind);
-		ERR_FAIL_V_MSG(nullptr, "Couldn't bind method '" + mdname + "' for instance '" + instance_type + "'.");
+		ERR_FAIL_V_MSG(nullptr, vformat("Couldn't bind method '%s' for instance '%s'.", mdname, instance_type));
 	}
 
 	if (!p_compatibility && type->method_map.has(mdname)) {
 		memdelete(p_bind);
 		// overloading not supported
-		ERR_FAIL_V_MSG(nullptr, "Method already bound '" + instance_type + "::" + mdname + "'.");
+		ERR_FAIL_V_MSG(nullptr, vformat("Method already bound '%s::%s'.", instance_type, mdname));
 	}
 
 #ifdef DEBUG_METHODS_ENABLED
 
 	if (method_name.args.size() > p_bind->get_argument_count()) {
 		memdelete(p_bind);
-		ERR_FAIL_V_MSG(nullptr, "Method definition provides more arguments than the method actually has '" + instance_type + "::" + mdname + "'.");
+		ERR_FAIL_V_MSG(nullptr, vformat("Method definition provides more arguments than the method actually has '%s::%s'.", instance_type, mdname));
 	}
 
 	p_bind->set_argument_names(method_name.args);
@@ -1964,7 +1964,7 @@ MethodBind *ClassDB::bind_methodfi(uint32_t p_flags, MethodBind *p_bind, bool p_
 }
 
 void ClassDB::add_virtual_method(const StringName &p_class, const MethodInfo &p_method, bool p_virtual, const Vector<String> &p_arg_names, bool p_object_core) {
-	ERR_FAIL_COND_MSG(!classes.has(p_class), "Request for nonexistent class '" + p_class + "'.");
+	ERR_FAIL_COND_MSG(!classes.has(p_class), vformat("Request for nonexistent class '%s'.", p_class));
 
 	OBJTYPE_WLOCK;
 
@@ -1979,7 +1979,7 @@ void ClassDB::add_virtual_method(const StringName &p_class, const MethodInfo &p_
 
 	if (!p_object_core) {
 		if (p_arg_names.size() != mi.arguments.size()) {
-			WARN_PRINT("Mismatch argument name count for virtual method: " + String(p_class) + "::" + p_method.name);
+			WARN_PRINT(vformat("Mismatch argument name count for virtual method: '%s::%s'.", String(p_class), p_method.name));
 		} else {
 			List<PropertyInfo>::Iterator itr = mi.arguments.begin();
 			for (int i = 0; i < p_arg_names.size(); ++itr, ++i) {
@@ -1990,7 +1990,7 @@ void ClassDB::add_virtual_method(const StringName &p_class, const MethodInfo &p_
 
 	if (classes[p_class].virtual_methods_map.has(p_method.name)) {
 		// overloading not supported
-		ERR_FAIL_MSG("Virtual method already bound '" + String(p_class) + "::" + p_method.name + "'.");
+		ERR_FAIL_MSG(vformat("Virtual method already bound '%s::%s'.", String(p_class), p_method.name));
 	}
 	classes[p_class].virtual_methods.push_back(mi);
 	classes[p_class].virtual_methods_map[p_method.name] = mi;
@@ -1999,7 +1999,7 @@ void ClassDB::add_virtual_method(const StringName &p_class, const MethodInfo &p_
 }
 
 void ClassDB::get_virtual_methods(const StringName &p_class, List<MethodInfo> *p_methods, bool p_no_inheritance) {
-	ERR_FAIL_COND_MSG(!classes.has(p_class), "Request for nonexistent class '" + p_class + "'.");
+	ERR_FAIL_COND_MSG(!classes.has(p_class), vformat("Request for nonexistent class '%s'.", p_class));
 
 #ifdef DEBUG_METHODS_ENABLED
 
@@ -2020,7 +2020,7 @@ void ClassDB::get_virtual_methods(const StringName &p_class, List<MethodInfo> *p
 }
 
 void ClassDB::add_extension_class_virtual_method(const StringName &p_class, const GDExtensionClassVirtualMethodInfo *p_method_info) {
-	ERR_FAIL_COND_MSG(!classes.has(p_class), "Request for nonexistent class '" + p_class + "'.");
+	ERR_FAIL_COND_MSG(!classes.has(p_class), vformat("Request for nonexistent class '%s'.", p_class));
 
 #ifdef DEBUG_METHODS_ENABLED
 	PackedStringArray arg_names;
@@ -2044,7 +2044,7 @@ void ClassDB::add_extension_class_virtual_method(const StringName &p_class, cons
 void ClassDB::set_class_enabled(const StringName &p_class, bool p_enable) {
 	OBJTYPE_WLOCK;
 
-	ERR_FAIL_COND_MSG(!classes.has(p_class), "Request for nonexistent class '" + p_class + "'.");
+	ERR_FAIL_COND_MSG(!classes.has(p_class), vformat("Request for nonexistent class '%s'.", p_class));
 	classes[p_class].disabled = !p_enable;
 }
 
@@ -2058,7 +2058,7 @@ bool ClassDB::is_class_enabled(const StringName &p_class) {
 		}
 	}
 
-	ERR_FAIL_NULL_V_MSG(ti, false, "Cannot get class '" + String(p_class) + "'.");
+	ERR_FAIL_NULL_V_MSG(ti, false, vformat("Cannot get class '%s'.", String(p_class)));
 	return !ti->disabled;
 }
 
@@ -2066,7 +2066,7 @@ bool ClassDB::is_class_exposed(const StringName &p_class) {
 	OBJTYPE_RLOCK;
 
 	ClassInfo *ti = classes.getptr(p_class);
-	ERR_FAIL_NULL_V_MSG(ti, false, "Cannot get class '" + String(p_class) + "'.");
+	ERR_FAIL_NULL_V_MSG(ti, false, vformat("Cannot get class '%s'.", String(p_class)));
 	return ti->exposed;
 }
 
@@ -2074,7 +2074,7 @@ bool ClassDB::is_class_reloadable(const StringName &p_class) {
 	OBJTYPE_RLOCK;
 
 	ClassInfo *ti = classes.getptr(p_class);
-	ERR_FAIL_NULL_V_MSG(ti, false, "Cannot get class '" + String(p_class) + "'.");
+	ERR_FAIL_NULL_V_MSG(ti, false, vformat("Cannot get class '%s'.", String(p_class)));
 	return ti->reloadable;
 }
 
@@ -2082,7 +2082,7 @@ bool ClassDB::is_class_runtime(const StringName &p_class) {
 	OBJTYPE_RLOCK;
 
 	ClassInfo *ti = classes.getptr(p_class);
-	ERR_FAIL_NULL_V_MSG(ti, false, "Cannot get class '" + String(p_class) + "'.");
+	ERR_FAIL_NULL_V_MSG(ti, false, vformat("Cannot get class '%s'.", String(p_class)));
 	return ti->is_runtime;
 }
 
@@ -2192,14 +2192,14 @@ Variant ClassDB::class_get_default_property_value(const StringName &p_class, con
 void ClassDB::register_extension_class(ObjectGDExtension *p_extension) {
 	GLOBAL_LOCK_FUNCTION;
 
-	ERR_FAIL_COND_MSG(classes.has(p_extension->class_name), "Class already registered: " + String(p_extension->class_name));
-	ERR_FAIL_COND_MSG(!classes.has(p_extension->parent_class_name), "Parent class name for extension class not found: " + String(p_extension->parent_class_name));
+	ERR_FAIL_COND_MSG(classes.has(p_extension->class_name), vformat("Class already registered: '%s'.", String(p_extension->class_name)));
+	ERR_FAIL_COND_MSG(!classes.has(p_extension->parent_class_name), vformat("Parent class name for extension class not found: '%s'.", String(p_extension->parent_class_name)));
 
 	ClassInfo *parent = classes.getptr(p_extension->parent_class_name);
 
 #ifdef TOOLS_ENABLED
 	// @todo This is a limitation of the current implementation, but it should be possible to remove.
-	ERR_FAIL_COND_MSG(p_extension->is_runtime && parent->gdextension && !parent->is_runtime, "Extension runtime class " + String(p_extension->class_name) + " cannot descend from " + parent->name + " which isn't also a runtime class");
+	ERR_FAIL_COND_MSG(p_extension->is_runtime && parent->gdextension && !parent->is_runtime, vformat("Extension runtime class '%s' cannot descend from '%s' which isn't also a runtime class.", String(p_extension->class_name), parent->name));
 #endif
 
 	ClassInfo c;
@@ -2215,7 +2215,7 @@ void ClassDB::register_extension_class(ObjectGDExtension *p_extension) {
 				concrete_ancestor->gdextension != nullptr) {
 			concrete_ancestor = concrete_ancestor->inherits_ptr;
 		}
-		ERR_FAIL_NULL_MSG(concrete_ancestor->creation_func, "Extension class " + String(p_extension->class_name) + " cannot extend native abstract class " + String(concrete_ancestor->name));
+		ERR_FAIL_NULL_MSG(concrete_ancestor->creation_func, vformat("Extension class '%s' cannot extend native abstract class '%s'.", String(p_extension->class_name), String(concrete_ancestor->name)));
 		c.creation_func = concrete_ancestor->creation_func;
 	}
 	c.inherits = parent->name;
@@ -2239,7 +2239,7 @@ void ClassDB::register_extension_class(ObjectGDExtension *p_extension) {
 
 void ClassDB::unregister_extension_class(const StringName &p_class, bool p_free_method_binds) {
 	ClassInfo *c = classes.getptr(p_class);
-	ERR_FAIL_NULL_MSG(c, "Class '" + String(p_class) + "' does not exist.");
+	ERR_FAIL_NULL_MSG(c, vformat("Class '%s' does not exist.", String(p_class)));
 	if (p_free_method_binds) {
 		for (KeyValue<StringName, MethodBind *> &F : c->method_map) {
 			memdelete(F.value);

core/object/object.cpp

@@ -750,7 +750,7 @@ Variant Object::callv(const StringName &p_method, const Array &p_args) {
 	Callable::CallError ce;
 	const Variant ret = callp(p_method, argptrs, p_args.size(), ce);
 	if (ce.error != Callable::CallError::CALL_OK) {
-		ERR_FAIL_V_MSG(Variant(), "Error calling method from 'callv': " + Variant::get_call_error_text(this, p_method, argptrs, p_args.size(), ce) + ".");
+		ERR_FAIL_V_MSG(Variant(), vformat("Error calling method from 'callv': %s.", Variant::get_call_error_text(this, p_method, argptrs, p_args.size(), ce)));
 	}
 	return ret;
 }
@@ -999,7 +999,7 @@ void Object::set_meta(const StringName &p_name, const Variant &p_value) {
 	if (E) {
 		E->value = p_value;
 	} else {
-		ERR_FAIL_COND_MSG(!p_name.operator String().is_valid_ascii_identifier(), "Invalid metadata identifier: '" + p_name + "'.");
+		ERR_FAIL_COND_MSG(!p_name.operator String().is_valid_ascii_identifier(), vformat("Invalid metadata identifier: '%s'.", p_name));
 		Variant *V = &metadata.insert(p_name, p_value)->value;
 
 		const String &sname = p_name;
@@ -1015,7 +1015,7 @@ Variant Object::get_meta(const StringName &p_name, const Variant &p_default) con
 		if (p_default != Variant()) {
 			return p_default;
 		} else {
-			ERR_FAIL_V_MSG(Variant(), "The object does not have any 'meta' values with the key '" + p_name + "'.");
+			ERR_FAIL_V_MSG(Variant(), vformat("The object does not have any 'meta' values with the key '%s'.", p_name));
 		}
 	}
 	return metadata[p_name];
@@ -1071,8 +1071,8 @@ void Object::get_meta_list(List<StringName> *p_list) const {
 
 void Object::add_user_signal(const MethodInfo &p_signal) {
 	ERR_FAIL_COND_MSG(p_signal.name.is_empty(), "Signal name cannot be empty.");
-	ERR_FAIL_COND_MSG(ClassDB::has_signal(get_class_name(), p_signal.name), "User signal's name conflicts with a built-in signal of '" + get_class_name() + "'.");
-	ERR_FAIL_COND_MSG(signal_map.has(p_signal.name), "Trying to add already existing signal '" + p_signal.name + "'.");
+	ERR_FAIL_COND_MSG(ClassDB::has_signal(get_class_name(), p_signal.name), vformat("User signal's name conflicts with a built-in signal of '%s'.", get_class_name()));
+	ERR_FAIL_COND_MSG(signal_map.has(p_signal.name), vformat("Trying to add already existing signal '%s'.", p_signal.name));
 	SignalData s;
 	s.user = p_signal;
 	signal_map[p_signal.name] = s;
@@ -1137,7 +1137,7 @@ Error Object::emit_signalp(const StringName &p_name, const Variant **p_args, int
 #ifdef DEBUG_ENABLED
 		bool signal_is_valid = ClassDB::has_signal(get_class_name(), p_name);
 		//check in script
-		ERR_FAIL_COND_V_MSG(!signal_is_valid && !script.is_null() && !Ref<Script>(script)->has_script_signal(p_name), ERR_UNAVAILABLE, "Can't emit non-existing signal " + String("\"") + p_name + "\".");
+		ERR_FAIL_COND_V_MSG(!signal_is_valid && !script.is_null() && !Ref<Script>(script)->has_script_signal(p_name), ERR_UNAVAILABLE, vformat("Can't emit non-existing signal \"%s\".", p_name));
 #endif
 		//not connected? just return
 		return ERR_UNAVAILABLE;
@@ -1210,7 +1210,7 @@ Error Object::emit_signalp(const StringName &p_name, const Variant **p_args, int
 				if (ce.error == Callable::CallError::CALL_ERROR_INVALID_METHOD && target && !ClassDB::class_exists(target->get_class_name())) {
 					//most likely object is not initialized yet, do not throw error.
 				} else {
-					ERR_PRINT("Error calling from signal '" + String(p_name) + "' to callable: " + Variant::get_callable_error_text(callable, args, argc, ce) + ".");
+					ERR_PRINT(vformat("Error calling from signal '%s' to callable: %s.", String(p_name), Variant::get_callable_error_text(callable, args, argc, ce)));
 					err = ERR_METHOD_NOT_FOUND;
 				}
 			}
@@ -1371,15 +1371,15 @@ void Object::get_signals_connected_to_this(List<Connection> *p_connections) cons
 }
 
 Error Object::connect(const StringName &p_signal, const Callable &p_callable, uint32_t p_flags) {
-	ERR_FAIL_COND_V_MSG(p_callable.is_null(), ERR_INVALID_PARAMETER, "Cannot connect to '" + p_signal + "': the provided callable is null.");
+	ERR_FAIL_COND_V_MSG(p_callable.is_null(), ERR_INVALID_PARAMETER, vformat("Cannot connect to '%s': the provided callable is null.", p_signal));
 
 	if (p_callable.is_standard()) {
 		// FIXME: This branch should probably removed in favor of the `is_valid()` branch, but there exist some classes
 		// that call `connect()` before they are fully registered with ClassDB. Until all such classes can be found
 		// and registered soon enough this branch is needed to allow `connect()` to succeed.
-		ERR_FAIL_NULL_V_MSG(p_callable.get_object(), ERR_INVALID_PARAMETER, "Cannot connect to '" + p_signal + "' to callable '" + p_callable + "': the callable object is null.");
+		ERR_FAIL_NULL_V_MSG(p_callable.get_object(), ERR_INVALID_PARAMETER, vformat("Cannot connect to '%s' to callable '%s': the callable object is null.", p_signal, p_callable));
 	} else {
-		ERR_FAIL_COND_V_MSG(!p_callable.is_valid(), ERR_INVALID_PARAMETER, "Cannot connect to '" + p_signal + "': the provided callable is not valid: " + p_callable);
+		ERR_FAIL_COND_V_MSG(!p_callable.is_valid(), ERR_INVALID_PARAMETER, vformat("Cannot connect to '%s': the provided callable is not valid: '%s'.", p_signal, p_callable));
 	}
 
 	SignalData *s = signal_map.getptr(p_signal);
@@ -1400,7 +1400,7 @@ Error Object::connect(const StringName &p_signal, const Callable &p_callable, ui
 #endif
 		}
 
-		ERR_FAIL_COND_V_MSG(!signal_is_valid, ERR_INVALID_PARAMETER, "In Object of type '" + String(get_class()) + "': Attempt to connect nonexistent signal '" + p_signal + "' to callable '" + p_callable + "'.");
+		ERR_FAIL_COND_V_MSG(!signal_is_valid, ERR_INVALID_PARAMETER, vformat("In Object of type '%s': Attempt to connect nonexistent signal '%s' to callable '%s'.", String(get_class()), p_signal, p_callable));
 
 		signal_map[p_signal] = SignalData();
 		s = &signal_map[p_signal];
@@ -1412,7 +1412,7 @@ Error Object::connect(const StringName &p_signal, const Callable &p_callable, ui
 			s->slot_map[*p_callable.get_base_comparator()].reference_count++;
 			return OK;
 		} else {
-			ERR_FAIL_V_MSG(ERR_INVALID_PARAMETER, "Signal '" + p_signal + "' is already connected to given callable '" + p_callable + "' in that object.");
+			ERR_FAIL_V_MSG(ERR_INVALID_PARAMETER, vformat("Signal '%s' is already connected to given callable '%s' in that object.", p_signal, p_callable));
 		}
 	}
 
@@ -1439,7 +1439,7 @@ Error Object::connect(const StringName &p_signal, const Callable &p_callable, ui
 }
 
 bool Object::is_connected(const StringName &p_signal, const Callable &p_callable) const {
-	ERR_FAIL_COND_V_MSG(p_callable.is_null(), false, "Cannot determine if connected to '" + p_signal + "': the provided callable is null."); // Should use `is_null`, see note in `connect` about the use of `is_valid`.
+	ERR_FAIL_COND_V_MSG(p_callable.is_null(), false, vformat("Cannot determine if connected to '%s': the provided callable is null.", p_signal)); // Should use `is_null`, see note in `connect` about the use of `is_valid`.
 	const SignalData *s = signal_map.getptr(p_signal);
 	if (!s) {
 		bool signal_is_valid = ClassDB::has_signal(get_class_name(), p_signal);
@@ -1451,7 +1451,7 @@ bool Object::is_connected(const StringName &p_signal, const Callable &p_callable
 			return false;
 		}
 
-		ERR_FAIL_V_MSG(false, "Nonexistent signal: " + p_signal + ".");
+		ERR_FAIL_V_MSG(false, vformat("Nonexistent signal: '%s'.", p_signal));
 	}
 
 	return s->slot_map.has(*p_callable.get_base_comparator());
@@ -1469,7 +1469,7 @@ bool Object::has_connections(const StringName &p_signal) const {
 			return false;
 		}
 
-		ERR_FAIL_V_MSG(false, "Nonexistent signal: " + p_signal + ".");
+		ERR_FAIL_V_MSG(false, vformat("Nonexistent signal: '%s'.", p_signal));
 	}
 
 	return !s->slot_map.is_empty();
@@ -1480,17 +1480,17 @@ void Object::disconnect(const StringName &p_signal, const Callable &p_callable)
 }
 
 bool Object::_disconnect(const StringName &p_signal, const Callable &p_callable, bool p_force) {
-	ERR_FAIL_COND_V_MSG(p_callable.is_null(), false, "Cannot disconnect from '" + p_signal + "': the provided callable is null."); // Should use `is_null`, see note in `connect` about the use of `is_valid`.
+	ERR_FAIL_COND_V_MSG(p_callable.is_null(), false, vformat("Cannot disconnect from '%s': the provided callable is null.", p_signal)); // Should use `is_null`, see note in `connect` about the use of `is_valid`.
 
 	SignalData *s = signal_map.getptr(p_signal);
 	if (!s) {
 		bool signal_is_valid = ClassDB::has_signal(get_class_name(), p_signal) ||
 				(!script.is_null() && Ref<Script>(script)->has_script_signal(p_signal));
-		ERR_FAIL_COND_V_MSG(signal_is_valid, false, "Attempt to disconnect a nonexistent connection from '" + to_string() + "'. Signal: '" + p_signal + "', callable: '" + p_callable + "'.");
+		ERR_FAIL_COND_V_MSG(signal_is_valid, false, vformat("Attempt to disconnect a nonexistent connection from '%s'. Signal: '%s', callable: '%s'.", to_string(), p_signal, p_callable));
 	}
-	ERR_FAIL_NULL_V_MSG(s, false, vformat("Disconnecting nonexistent signal '%s' in %s.", p_signal, to_string()));
+	ERR_FAIL_NULL_V_MSG(s, false, vformat("Disconnecting nonexistent signal '%s' in '%s'.", p_signal, to_string()));
 
-	ERR_FAIL_COND_V_MSG(!s->slot_map.has(*p_callable.get_base_comparator()), false, "Attempt to disconnect a nonexistent connection from '" + to_string() + "'. Signal: '" + p_signal + "', callable: '" + p_callable + "'.");
+	ERR_FAIL_COND_V_MSG(!s->slot_map.has(*p_callable.get_base_comparator()), false, vformat("Attempt to disconnect a nonexistent connection from '%s'. Signal: '%s', callable: '%s'.", to_string(), p_signal, p_callable));
 
 	SignalData::Slot *slot = &s->slot_map[*p_callable.get_base_comparator()];
 
@@ -2128,7 +2128,7 @@ Object::~Object() {
 
 	if (_emitting) {
 		//@todo this may need to actually reach the debugger prioritarily somehow because it may crash before
-		ERR_PRINT("Object " + to_string() + " was freed or unreferenced while a signal is being emitted from it. Try connecting to the signal using 'CONNECT_DEFERRED' flag, or use queue_free() to free the object (if this object is a Node) to avoid this error and potential crashes.");
+		ERR_PRINT(vformat("Object '%s' was freed or unreferenced while a signal is being emitted from it. Try connecting to the signal using 'CONNECT_DEFERRED' flag, or use queue_free() to free the object (if this object is a Node) to avoid this error and potential crashes.", to_string()));
 	}
 
 	// Drop all connections to the signals of this object.

core/object/script_language.cpp

@@ -239,9 +239,9 @@ Error ScriptServer::register_language(ScriptLanguage *p_language) {
 	ERR_FAIL_COND_V_MSG(_language_count >= MAX_LANGUAGES, ERR_UNAVAILABLE, "Script languages limit has been reach, cannot register more.");
 	for (int i = 0; i < _language_count; i++) {
 		const ScriptLanguage *other_language = _languages[i];
-		ERR_FAIL_COND_V_MSG(other_language->get_extension() == p_language->get_extension(), ERR_ALREADY_EXISTS, "A script language with extension '" + p_language->get_extension() + "' is already registered.");
-		ERR_FAIL_COND_V_MSG(other_language->get_name() == p_language->get_name(), ERR_ALREADY_EXISTS, "A script language with name '" + p_language->get_name() + "' is already registered.");
-		ERR_FAIL_COND_V_MSG(other_language->get_type() == p_language->get_type(), ERR_ALREADY_EXISTS, "A script language with type '" + p_language->get_type() + "' is already registered.");
+		ERR_FAIL_COND_V_MSG(other_language->get_extension() == p_language->get_extension(), ERR_ALREADY_EXISTS, vformat("A script language with extension '%s' is already registered.", p_language->get_extension()));
+		ERR_FAIL_COND_V_MSG(other_language->get_name() == p_language->get_name(), ERR_ALREADY_EXISTS, vformat("A script language with name '%s' is already registered.", p_language->get_name()));
+		ERR_FAIL_COND_V_MSG(other_language->get_type() == p_language->get_type(), ERR_ALREADY_EXISTS, vformat("A script language with type '%s' is already registered.", p_language->get_type()));
 	}
 	_languages[_language_count++] = p_language;
 	return OK;

core/object/undo_redo.cpp

@@ -364,7 +364,7 @@ void UndoRedo::_process_operation_list(List<Operation>::Element *E, bool p_execu
 					Variant ret;
 					op.callable.callp(nullptr, 0, ret, ce);
 					if (ce.error != Callable::CallError::CALL_OK) {
-						ERR_PRINT("Error calling UndoRedo method operation '" + String(op.name) + "': " + Variant::get_call_error_text(obj, op.name, nullptr, 0, ce));
+						ERR_PRINT(vformat("Error calling UndoRedo method operation '%s': %s.", String(op.name), Variant::get_call_error_text(obj, op.name, nullptr, 0, ce)));
 					}
 #ifdef TOOLS_ENABLED
 					Resource *res = Object::cast_to<Resource>(obj);

core/os/os.cpp

@@ -352,7 +352,7 @@ void OS::ensure_user_data_dir() {
 
 	Ref<DirAccess> da = DirAccess::create(DirAccess::ACCESS_FILESYSTEM);
 	Error err = da->make_dir_recursive(dd);
-	ERR_FAIL_COND_MSG(err != OK, "Error attempting to create data dir: " + dd + ".");
+	ERR_FAIL_COND_MSG(err != OK, vformat("Error attempting to create data dir: %s.", dd));
 }
 
 String OS::get_model_name() const {

core/string/node_path.cpp

@@ -420,7 +420,7 @@ NodePath::NodePath(const String &p_path) {
 						continue; // Allow end-of-path :
 					}
 
-					ERR_FAIL_MSG("Invalid NodePath '" + p_path + "'.");
+					ERR_FAIL_MSG(vformat("Invalid NodePath '%s'.", p_path));
 				}
 				subpath.push_back(str);
 

core/string/translation_po.cpp

@@ -246,7 +246,7 @@ void TranslationPO::add_message(const StringName &p_src_text, const StringName &
 	HashMap<StringName, Vector<StringName>> &map_id_str = translation_map[p_context];
 
 	if (map_id_str.has(p_src_text)) {
-		WARN_PRINT("Double translations for \"" + String(p_src_text) + "\" under the same context \"" + String(p_context) + "\" for locale \"" + get_locale() + "\".\nThere should only be one unique translation for a given string under the same context.");
+		WARN_PRINT(vformat("Double translations for \"%s\" under the same context \"%s\" for locale \"%s\".\nThere should only be one unique translation for a given string under the same context.", String(p_src_text), String(p_context), get_locale()));
 		map_id_str[p_src_text].set(0, p_xlated_text);
 	} else {
 		map_id_str[p_src_text].push_back(p_xlated_text);
@@ -254,12 +254,12 @@ void TranslationPO::add_message(const StringName &p_src_text, const StringName &
 }
 
 void TranslationPO::add_plural_message(const StringName &p_src_text, const Vector<String> &p_plural_xlated_texts, const StringName &p_context) {
-	ERR_FAIL_COND_MSG(p_plural_xlated_texts.size() != plural_forms, "Trying to add plural texts that don't match the required number of plural forms for locale \"" + get_locale() + "\"");
+	ERR_FAIL_COND_MSG(p_plural_xlated_texts.size() != plural_forms, vformat("Trying to add plural texts that don't match the required number of plural forms for locale \"%s\".", get_locale()));
 
 	HashMap<StringName, Vector<StringName>> &map_id_str = translation_map[p_context];
 
 	if (map_id_str.has(p_src_text)) {
-		WARN_PRINT("Double translations for \"" + p_src_text + "\" under the same context \"" + p_context + "\" for locale " + get_locale() + ".\nThere should only be one unique translation for a given string under the same context.");
+		WARN_PRINT(vformat("Double translations for \"%s\" under the same context \"%s\" for locale %s.\nThere should only be one unique translation for a given string under the same context.", p_src_text, p_context, get_locale()));
 		map_id_str[p_src_text].clear();
 	}
 
@@ -280,7 +280,7 @@ StringName TranslationPO::get_message(const StringName &p_src_text, const String
 	if (!translation_map.has(p_context) || !translation_map[p_context].has(p_src_text)) {
 		return StringName();
 	}
-	ERR_FAIL_COND_V_MSG(translation_map[p_context][p_src_text].is_empty(), StringName(), "Source text \"" + String(p_src_text) + "\" is registered but doesn't have a translation. Please report this bug.");
+	ERR_FAIL_COND_V_MSG(translation_map[p_context][p_src_text].is_empty(), StringName(), vformat("Source text \"%s\" is registered but doesn't have a translation. Please report this bug.", String(p_src_text)));
 
 	return translation_map[p_context][p_src_text][0];
 }
@@ -296,7 +296,7 @@ StringName TranslationPO::get_plural_message(const StringName &p_src_text, const
 	if (!translation_map.has(p_context) || !translation_map[p_context].has(p_src_text)) {
 		return StringName();
 	}
-	ERR_FAIL_COND_V_MSG(translation_map[p_context][p_src_text].is_empty(), StringName(), "Source text \"" + String(p_src_text) + "\" is registered but doesn't have a translation. Please report this bug.");
+	ERR_FAIL_COND_V_MSG(translation_map[p_context][p_src_text].is_empty(), StringName(), vformat("Source text \"%s\" is registered but doesn't have a translation. Please report this bug.", String(p_src_text)));
 
 	int plural_index = _get_plural_index(p_n);
 	ERR_FAIL_COND_V_MSG(plural_index < 0 || translation_map[p_context][p_src_text].size() < plural_index + 1, StringName(), "Plural index returned or number of plural translations is not valid. Please report this bug.");

core/variant/array.cpp

@@ -385,7 +385,7 @@ int Array::find_custom(const Callable &p_callable, int p_from) const {
 		Callable::CallError ce;
 		p_callable.callp(argptrs, 1, res, ce);
 		if (unlikely(ce.error != Callable::CallError::CALL_OK)) {
-			ERR_FAIL_V_MSG(ret, "Error calling method from 'find_custom': " + Variant::get_callable_error_text(p_callable, argptrs, 1, ce));
+			ERR_FAIL_V_MSG(ret, vformat("Error calling method from 'find_custom': %s.", Variant::get_callable_error_text(p_callable, argptrs, 1, ce)));
 		}
 
 		ERR_FAIL_COND_V_MSG(res.get_type() != Variant::Type::BOOL, ret, "Error on method from 'find_custom': Return type of callable must be boolean.");
@@ -445,7 +445,7 @@ int Array::rfind_custom(const Callable &p_callable, int p_from) const {
 		Callable::CallError ce;
 		p_callable.callp(argptrs, 1, res, ce);
 		if (unlikely(ce.error != Callable::CallError::CALL_OK)) {
-			ERR_FAIL_V_MSG(-1, "Error calling method from 'rfind_custom': " + Variant::get_callable_error_text(p_callable, argptrs, 1, ce));
+			ERR_FAIL_V_MSG(-1, vformat("Error calling method from 'rfind_custom': %s.", Variant::get_callable_error_text(p_callable, argptrs, 1, ce)));
 		}
 
 		ERR_FAIL_COND_V_MSG(res.get_type() != Variant::Type::BOOL, -1, "Error on method from 'rfind_custom': Return type of callable must be boolean.");
@@ -574,7 +574,7 @@ Array Array::filter(const Callable &p_callable) const {
 		Callable::CallError ce;
 		p_callable.callp(argptrs, 1, result, ce);
 		if (ce.error != Callable::CallError::CALL_OK) {
-			ERR_FAIL_V_MSG(Array(), "Error calling method from 'filter': " + Variant::get_callable_error_text(p_callable, argptrs, 1, ce));
+			ERR_FAIL_V_MSG(Array(), vformat("Error calling method from 'filter': %s.", Variant::get_callable_error_text(p_callable, argptrs, 1, ce)));
 		}
 
 		if (result.operator bool()) {
@@ -600,7 +600,7 @@ Array Array::map(const Callable &p_callable) const {
 		Callable::CallError ce;
 		p_callable.callp(argptrs, 1, result, ce);
 		if (ce.error != Callable::CallError::CALL_OK) {
-			ERR_FAIL_V_MSG(Array(), "Error calling method from 'map': " + Variant::get_callable_error_text(p_callable, argptrs, 1, ce));
+			ERR_FAIL_V_MSG(Array(), vformat("Error calling method from 'map': %s.", Variant::get_callable_error_text(p_callable, argptrs, 1, ce)));
 		}
 
 		new_arr[i] = result;
@@ -626,7 +626,7 @@ Variant Array::reduce(const Callable &p_callable, const Variant &p_accum) const
 		Callable::CallError ce;
 		p_callable.callp(argptrs, 2, result, ce);
 		if (ce.error != Callable::CallError::CALL_OK) {
-			ERR_FAIL_V_MSG(Variant(), "Error calling method from 'reduce': " + Variant::get_callable_error_text(p_callable, argptrs, 2, ce));
+			ERR_FAIL_V_MSG(Variant(), vformat("Error calling method from 'reduce': %s.", Variant::get_callable_error_text(p_callable, argptrs, 2, ce)));
 		}
 		ret = result;
 	}
@@ -643,7 +643,7 @@ bool Array::any(const Callable &p_callable) const {
 		Callable::CallError ce;
 		p_callable.callp(argptrs, 1, result, ce);
 		if (ce.error != Callable::CallError::CALL_OK) {
-			ERR_FAIL_V_MSG(false, "Error calling method from 'any': " + Variant::get_callable_error_text(p_callable, argptrs, 1, ce));
+			ERR_FAIL_V_MSG(false, vformat("Error calling method from 'any': %s.", Variant::get_callable_error_text(p_callable, argptrs, 1, ce)));
 		}
 
 		if (result.operator bool()) {
@@ -665,7 +665,7 @@ bool Array::all(const Callable &p_callable) const {
 		Callable::CallError ce;
 		p_callable.callp(argptrs, 1, result, ce);
 		if (ce.error != Callable::CallError::CALL_OK) {
-			ERR_FAIL_V_MSG(false, "Error calling method from 'all': " + Variant::get_callable_error_text(p_callable, argptrs, 1, ce));
+			ERR_FAIL_V_MSG(false, vformat("Error calling method from 'all': %s.", Variant::get_callable_error_text(p_callable, argptrs, 1, ce)));
 		}
 
 		if (!(result.operator bool())) {

core/variant/container_type_validate.h

@@ -94,7 +94,7 @@ struct ContainerTypeValidate {
 				return true;
 			}
 
-			ERR_FAIL_V_MSG(false, "Attempted to " + String(p_operation) + " a variable of type '" + Variant::get_type_name(inout_variant.get_type()) + "' into a " + where + " of type '" + Variant::get_type_name(type) + "'.");
+			ERR_FAIL_V_MSG(false, vformat("Attempted to %s a variable of type '%s' into a %s of type '%s'.", String(p_operation), Variant::get_type_name(inout_variant.get_type()), where, Variant::get_type_name(type)));
 		}
 
 		if (type != Variant::OBJECT) {
@@ -113,7 +113,7 @@ struct ContainerTypeValidate {
 			return true; // This is fine, it's null.
 		}
 		Object *object = ObjectDB::get_instance(object_id);
-		ERR_FAIL_NULL_V_MSG(object, false, "Attempted to " + String(p_operation) + " an invalid (previously freed?) object instance into a '" + String(where) + ".");
+		ERR_FAIL_NULL_V_MSG(object, false, vformat("Attempted to %s an invalid (previously freed?) object instance into a '%s'.", String(p_operation), String(where)));
 #else
 		Object *object = p_variant;
 		if (object == nullptr) {
@@ -126,7 +126,7 @@ struct ContainerTypeValidate {
 
 		StringName obj_class = object->get_class_name();
 		if (obj_class != class_name) {
-			ERR_FAIL_COND_V_MSG(!ClassDB::is_parent_class(object->get_class_name(), class_name), false, "Attempted to " + String(p_operation) + " an object of type '" + object->get_class() + "' into a " + where + ", which does not inherit from '" + String(class_name) + "'.");
+			ERR_FAIL_COND_V_MSG(!ClassDB::is_parent_class(object->get_class_name(), class_name), false, vformat("Attempted to %s an object of type '%s' into a %s, which does not inherit from '%s'.", String(p_operation), object->get_class(), where, String(class_name)));
 		}
 
 		if (script.is_null()) {
@@ -136,8 +136,8 @@ struct ContainerTypeValidate {
 		Ref<Script> other_script = object->get_script();
 
 		// Check base script..
-		ERR_FAIL_COND_V_MSG(other_script.is_null(), false, "Attempted to " + String(p_operation) + " an object into a " + String(where) + ", that does not inherit from '" + String(script->get_class_name()) + "'.");
-		ERR_FAIL_COND_V_MSG(!other_script->inherits_script(script), false, "Attempted to " + String(p_operation) + " an object into a " + String(where) + ", that does not inherit from '" + String(script->get_class_name()) + "'.");
+		ERR_FAIL_COND_V_MSG(other_script.is_null(), false, vformat("Attempted to %s an object into a %s, that does not inherit from '%s'.", String(p_operation), String(where), String(script->get_class_name())));
+		ERR_FAIL_COND_V_MSG(!other_script->inherits_script(script), false, vformat("Attempted to %s an object into a %s, that does not inherit from '%s'.", String(p_operation), String(where), String(script->get_class_name())));
 
 		return true;
 	}

core/variant/variant_construct.cpp

@@ -43,7 +43,7 @@ static LocalVector<VariantConstructData> construct_data[Variant::VARIANT_MAX];
 
 template <typename T>
 static void add_constructor(const Vector<String> &arg_names) {
-	ERR_FAIL_COND_MSG(arg_names.size() != T::get_argument_count(), "Argument names size mismatch for " + Variant::get_type_name(T::get_base_type()) + ".");
+	ERR_FAIL_COND_MSG(arg_names.size() != T::get_argument_count(), vformat("Argument names size mismatch for '%s'.", Variant::get_type_name(T::get_base_type())));
 
 	VariantConstructData cd;
 	cd.construct = T::construct;

core/variant/variant_utility.cpp

@@ -1671,7 +1671,7 @@ static void register_utility_function(const String &p_name, const Vector<String>
 	bfi.argnames = argnames;
 	bfi.argcount = T::get_argument_count();
 	if (!bfi.is_vararg) {
-		ERR_FAIL_COND_MSG(argnames.size() != bfi.argcount, "wrong number of arguments binding utility function: " + name);
+		ERR_FAIL_COND_MSG(argnames.size() != bfi.argcount, vformat("Wrong number of arguments binding utility function: '%s'.", name));
 	}
 	bfi.get_arg_type = T::get_argument_type;
 	bfi.return_type = T::get_return_type();