Editor: Allow to override CLI args on a per-instance basis

core/config/project_settings.cpp

@@ -1221,6 +1221,10 @@ ProjectSettings::ProjectSettings() {
 	extensions.push_back("gdshader");
 
 	GLOBAL_DEF("editor/run/main_run_args", "");
+	GLOBAL_DEF("editor/run/instance_1_run_args", "");
+	GLOBAL_DEF("editor/run/instance_2_run_args", "");
+	GLOBAL_DEF("editor/run/instance_3_run_args", "");
+	GLOBAL_DEF("editor/run/instance_4_run_args", "");
 
 	GLOBAL_DEF("editor/script/search_in_file_extensions", extensions);
 	custom_prop_info["editor/script/search_in_file_extensions"] = PropertyInfo(Variant::PACKED_STRING_ARRAY, "editor/script/search_in_file_extensions");

doc/classes/ProjectSettings.xml

@@ -536,13 +536,32 @@
 		<member name="editor/node_naming/name_num_separator" type="int" setter="" getter="" default="0">
 			What to use to separate node name from number. This is mostly an editor setting.
 		</member>
+		<member name="editor/run/instance_1_run_args" type="String" setter="" getter="" default="&quot;&quot;">
+			The command-line arguments to use for instance 1 when running the project. This overrides the arguments set in [member editor/run/main_run_args].
+			For further details, see [member editor/run/main_run_args].
+			Instance 1 is the default instance. The Editor can be set to start multiple instances by using the "Run Multiple Instances" setting in the Debug menu.
+		</member>
+		<member name="editor/run/instance_2_run_args" type="String" setter="" getter="" default="&quot;&quot;">
+			The command-line arguments to use for instance 2 when running the project. This overrides the arguments set in [member editor/run/main_run_args].
+			For further details, see [member editor/run/main_run_args]. The Editor can be set to start multiple instances by using the "Run Multiple Instances" setting in the Debug menu.
+		</member>
+		<member name="editor/run/instance_3_run_args" type="String" setter="" getter="" default="&quot;&quot;">
+			The command-line arguments to use for instance 3 when running the project. This overrides the arguments set in [member editor/run/main_run_args].
+			For further details, see [member editor/run/main_run_args]. The Editor can be set to start multiple instances by using the "Run Multiple Instances" setting in the Debug menu.
+		</member>
+		<member name="editor/run/instance_4_run_args" type="String" setter="" getter="" default="&quot;&quot;">
+			The command-line arguments to use for instance 3 when running the project. This overrides the arguments set in [member editor/run/main_run_args].
+			For further details, see [member editor/run/main_run_args]. The Editor can be set to start multiple instances by using the "Run Multiple Instances" setting in the Debug menu.
+		</member>
 		<member name="editor/run/main_run_args" type="String" setter="" getter="" default="&quot;&quot;">
 			The command-line arguments to append to Godot's own command line when running the project. This doesn't affect the editor itself.
 			It is possible to make another executable run Godot by using the [code]%command%[/code] placeholder. The placeholder will be replaced with Godot's own command line. Program-specific arguments should be placed [i]before[/i] the placeholder, whereas Godot-specific arguments should be placed [i]after[/i] the placeholder.
 			For example, this can be used to force the project to run on the dedicated GPU in a NVIDIA Optimus system on Linux:
 			[codeblock]
 			prime-run %command%
 			[/codeblock]
+			Note that the settings [member editor/run/instance_1_run_args] to [member editor/run/instance_4_run_args] allow to override these arguments on a per-instance basis.
+			Instance 1 is the default instance. Instances 2 to 4 can be enabled by using the "Run Multiple Instances" setting in the Debug menu.
 		</member>
 		<member name="editor/script/search_in_file_extensions" type="PackedStringArray" setter="" getter="" default="PackedStringArray(&quot;gd&quot;, &quot;gdshader&quot;)">
 			Text-based file extensions to include in the script editor's "Find in Files" feature. You can add e.g. [code]tscn[/code] if you wish to also parse your scene files, especially if you use built-in scripts which are serialized in the scene files.

editor/editor_run.cpp

@@ -184,9 +184,44 @@ Error EditorRun::run(const String &p_scene) {
 		args.push_back(p_scene);
 	}
 
-	String exec = OS::get_singleton()->get_executable_path();
+	int instances = EditorSettings::get_singleton()->get_project_metadata("debug_options", "run_debug_instances", 1);
+	for (int instance_num = 1; instance_num <= instances; instance_num++) {
+		List<String> instance_args;
+		for (int i = 0; i < args.size(); i++) {
+			instance_args.push_back(args[i]);
+		}
+
+		String exec;
+		String instance_arg_setting = "editor/run/instance_" + itos(instance_num) + "_run_args";
+		String raw_custom_args = ProjectSettings::get_singleton()->get(instance_arg_setting);
+		if (raw_custom_args.is_empty()) {
+			// Fallback to main run args if no instance specific run args exist.
+			raw_custom_args = ProjectSettings::get_singleton()->get("editor/run/main_run_args");
+		}
+		parse_run_args(&exec, &instance_args, raw_custom_args);
+
+		printf("Running: %s", exec.utf8().get_data());
+		for (const String &E : instance_args) {
+			printf(" %s", E.utf8().get_data());
+		};
+		printf("\n");
+
+		OS::ProcessID pid = 0;
+		Error err = OS::get_singleton()->create_instance(instance_args, &pid);
+		ERR_FAIL_COND_V(err, err);
+		pids.push_back(pid);
+	}
+
+	status = STATUS_PLAY;
+	if (!p_scene.is_empty()) {
+		running_scene = p_scene;
+	}
+
+	return OK;
+}
 
-	const String raw_custom_args = ProjectSettings::get_singleton()->get("editor/run/main_run_args");
+void EditorRun::parse_run_args(String *exec_path, List<String> *args, const String raw_custom_args) {
+	*exec_path = OS::get_singleton()->get_executable_path();
 	if (!raw_custom_args.is_empty()) {
 		// Allow the user to specify a command to run, similar to Steam's launch options.
 		// In this case, Godot will no longer be run directly; it's up to the underlying command
@@ -202,53 +237,32 @@ Error EditorRun::run(const String &p_scene) {
 			// If nothing is placed before `%command%`, behave as if no placeholder was specified.
 			Vector<String> exec_args = raw_custom_args.substr(0, placeholder_pos).split(" ", false);
 			if (exec_args.size() >= 1) {
-				exec = exec_args[0];
+				*exec_path = exec_args[0];
 				exec_args.remove_at(0);
 
 				// Append the Godot executable name before we append executable arguments
 				// (since the order is reversed when using `push_front()`).
-				args.push_front(OS::get_singleton()->get_executable_path());
+				args->push_front(OS::get_singleton()->get_executable_path());
 			}
 
 			for (int i = exec_args.size() - 1; i >= 0; i--) {
 				// Iterate backwards as we're pushing items in the reverse order.
-				args.push_front(exec_args[i].replace(" ", "%20"));
+				args->push_front(exec_args[i].replace(" ", "%20"));
 			}
 
 			// Append Godot-specific custom arguments.
 			custom_args = raw_custom_args.substr(placeholder_pos + String("%command%").size()).split(" ", false);
 			for (int i = 0; i < custom_args.size(); i++) {
-				args.push_back(custom_args[i].replace(" ", "%20"));
+				args->push_back(custom_args[i].replace(" ", "%20"));
 			}
 		} else {
 			// Append Godot-specific custom arguments.
 			custom_args = raw_custom_args.split(" ", false);
 			for (int i = 0; i < custom_args.size(); i++) {
-				args.push_back(custom_args[i].replace(" ", "%20"));
+				args->push_back(custom_args[i].replace(" ", "%20"));
 			}
 		}
 	}
-
-	printf("Running: %s", exec.utf8().get_data());
-	for (const String &E : args) {
-		printf(" %s", E.utf8().get_data());
-	};
-	printf("\n");
-
-	int instances = EditorSettings::get_singleton()->get_project_metadata("debug_options", "run_debug_instances", 1);
-	for (int i = 0; i < instances; i++) {
-		OS::ProcessID pid = 0;
-		Error err = OS::get_singleton()->create_instance(args, &pid);
-		ERR_FAIL_COND_V(err, err);
-		pids.push_back(pid);
-	}
-
-	status = STATUS_PLAY;
-	if (!p_scene.is_empty()) {
-		running_scene = p_scene;
-	}
-
-	return OK;
 }
 
 bool EditorRun::has_child_process(OS::ProcessID p_pid) const {

editor/editor_run.h

@@ -47,6 +47,8 @@ class EditorRun {
 	Status status;
 	String running_scene;
 
+	void parse_run_args(String *exec_path, List<String> *args, const String raw_custom_args);
+
 public:
 	Status get_status() const;
 	String get_running_scene() const;