From 24b6edcd388836910655689fd6dd7bc3717ff256 Mon Sep 17 00:00:00 2001
From: Danil Alexeev <danil@alexeev.xyz>
Date: Thu, 20 Jun 2024 13:05:29 +0300
Subject: [PATCH] GDScript: Fix non-global class export

---
 modules/gdscript/doc_classes/@GDScript.xml    |   2 +-
 modules/gdscript/gdscript_parser.cpp          | 110 ++++++++++--------
 .../parser/features/export_variable.gd        |   6 +-
 .../parser/features/export_variable.notest.gd |   2 -
 .../parser/features/export_variable.out       |   6 +-
 .../features/export_variable_global.notest.gd |   2 +
 .../export_variable_unnamed.notest.gd         |   1 +
 7 files changed, 72 insertions(+), 57 deletions(-)
 delete mode 100644 modules/gdscript/tests/scripts/parser/features/export_variable.notest.gd
 create mode 100644 modules/gdscript/tests/scripts/parser/features/export_variable_global.notest.gd
 create mode 100644 modules/gdscript/tests/scripts/parser/features/export_variable_unnamed.notest.gd

diff --git a/modules/gdscript/doc_classes/@GDScript.xml b/modules/gdscript/doc_classes/@GDScript.xml
index 1909ca5ab52..6e7ac0dec96 100644
--- a/modules/gdscript/doc_classes/@GDScript.xml
+++ b/modules/gdscript/doc_classes/@GDScript.xml
@@ -314,7 +314,7 @@
 				@export var image_array: Array[Image]
 				@export var node_array: Array[Node]
 				[/codeblock]
-				[b]Note:[/b] Custom resources and nodes must be registered as global classes using [code]class_name[/code].
+				[b]Note:[/b] Custom resources and nodes should be registered as global classes using [code]class_name[/code], since the Inspector currently only supports global classes. Otherwise, a less specific type will be exported instead.
 				[b]Note:[/b] Node export is only supported in [Node]-derived classes and has a number of other limitations.
 			</description>
 		</annotation>
diff --git a/modules/gdscript/gdscript_parser.cpp b/modules/gdscript/gdscript_parser.cpp
index f1a35c84b7f..d0948e48313 100644
--- a/modules/gdscript/gdscript_parser.cpp
+++ b/modules/gdscript/gdscript_parser.cpp
@@ -4160,6 +4160,64 @@ static String _get_annotation_error_string(const StringName &p_annotation_name,
 	return vformat(R"("%s" annotation requires a variable of type %s, but type "%s" was given instead.)", p_annotation_name, string, p_provided_type.to_string());
 }
 
+static StringName _find_narrowest_native_or_global_class(const GDScriptParser::DataType &p_type) {
+	switch (p_type.kind) {
+		case GDScriptParser::DataType::NATIVE: {
+			if (p_type.is_meta_type) {
+				return Object::get_class_static(); // `GDScriptNativeClass` is not an exposed class.
+			}
+			return p_type.native_type;
+		} break;
+		case GDScriptParser::DataType::SCRIPT: {
+			Ref<Script> script;
+			if (p_type.script_type.is_valid()) {
+				script = p_type.script_type;
+			} else {
+				script = ResourceLoader::load(p_type.script_path, SNAME("Script"));
+			}
+
+			if (p_type.is_meta_type) {
+				return script.is_valid() ? script->get_class() : Script::get_class_static();
+			}
+			if (script.is_null()) {
+				return p_type.native_type;
+			}
+			if (script->get_global_name() != StringName()) {
+				return script->get_global_name();
+			}
+
+			Ref<Script> base_script = script->get_base_script();
+			if (base_script.is_null()) {
+				return script->get_instance_base_type();
+			}
+
+			GDScriptParser::DataType base_type;
+			base_type.kind = GDScriptParser::DataType::SCRIPT;
+			base_type.builtin_type = Variant::OBJECT;
+			base_type.native_type = base_script->get_instance_base_type();
+			base_type.script_type = base_script;
+			base_type.script_path = base_script->get_path();
+
+			return _find_narrowest_native_or_global_class(base_type);
+		} break;
+		case GDScriptParser::DataType::CLASS: {
+			if (p_type.is_meta_type) {
+				return GDScript::get_class_static();
+			}
+			if (p_type.class_type == nullptr) {
+				return p_type.native_type;
+			}
+			if (p_type.class_type->get_global_name() != StringName()) {
+				return p_type.class_type->get_global_name();
+			}
+			return _find_narrowest_native_or_global_class(p_type.class_type->base_type);
+		} break;
+		default: {
+			ERR_FAIL_V(StringName());
+		} break;
+	}
+}
+
 template <PropertyHint t_hint, Variant::Type t_type>
 bool GDScriptParser::export_annotations(const AnnotationNode *p_annotation, Node *p_target, ClassNode *p_class) {
 	ERR_FAIL_COND_V_MSG(p_target->type != Node::VARIABLE, false, vformat(R"("%s" annotation can only be applied to variables.)", p_annotation->name));
@@ -4302,57 +4360,9 @@ bool GDScriptParser::export_annotations(const AnnotationNode *p_annotation, Node
 				variable->export_info.hint_string = String();
 				break;
 			case GDScriptParser::DataType::NATIVE:
-				if (ClassDB::is_parent_class(export_type.native_type, SNAME("Resource"))) {
-					variable->export_info.type = Variant::OBJECT;
-					variable->export_info.hint = PROPERTY_HINT_RESOURCE_TYPE;
-					variable->export_info.hint_string = export_type.native_type;
-				} else if (ClassDB::is_parent_class(export_type.native_type, SNAME("Node"))) {
-					variable->export_info.type = Variant::OBJECT;
-					variable->export_info.hint = PROPERTY_HINT_NODE_TYPE;
-					variable->export_info.hint_string = export_type.native_type;
-				} else {
-					push_error(R"(Export type can only be built-in, a resource, a node, or an enum.)", p_annotation);
-					return false;
-				}
-				break;
+			case GDScriptParser::DataType::SCRIPT:
 			case GDScriptParser::DataType::CLASS: {
-				StringName class_name;
-				if (export_type.class_type) {
-					class_name = export_type.class_type->get_global_name();
-				}
-				if (class_name == StringName()) {
-					push_error(R"(Script export type must be a global class.)", p_annotation);
-					return false;
-				}
-				if (ClassDB::is_parent_class(export_type.native_type, SNAME("Resource"))) {
-					variable->export_info.type = Variant::OBJECT;
-					variable->export_info.hint = PROPERTY_HINT_RESOURCE_TYPE;
-					variable->export_info.hint_string = class_name;
-				} else if (ClassDB::is_parent_class(export_type.native_type, SNAME("Node"))) {
-					variable->export_info.type = Variant::OBJECT;
-					variable->export_info.hint = PROPERTY_HINT_NODE_TYPE;
-					variable->export_info.hint_string = class_name;
-				} else {
-					push_error(R"(Export type can only be built-in, a resource, a node, or an enum.)", p_annotation);
-					return false;
-				}
-			} break;
-
-			case GDScriptParser::DataType::SCRIPT: {
-				StringName class_name;
-				if (export_type.script_type.is_valid()) {
-					class_name = export_type.script_type->get_global_name();
-				}
-				if (class_name == StringName()) {
-					Ref<Script> script = ResourceLoader::load(export_type.script_path, SNAME("Script"));
-					if (script.is_valid()) {
-						class_name = script->get_global_name();
-					}
-				}
-				if (class_name == StringName()) {
-					push_error(R"(Script export type must be a global class.)", p_annotation);
-					return false;
-				}
+				const StringName class_name = _find_narrowest_native_or_global_class(export_type);
 				if (ClassDB::is_parent_class(export_type.native_type, SNAME("Resource"))) {
 					variable->export_info.type = Variant::OBJECT;
 					variable->export_info.hint = PROPERTY_HINT_RESOURCE_TYPE;
diff --git a/modules/gdscript/tests/scripts/parser/features/export_variable.gd b/modules/gdscript/tests/scripts/parser/features/export_variable.gd
index 483e6cab0d2..8bcb2bcb9a5 100644
--- a/modules/gdscript/tests/scripts/parser/features/export_variable.gd
+++ b/modules/gdscript/tests/scripts/parser/features/export_variable.gd
@@ -2,7 +2,8 @@ class_name ExportVariableTest
 extends Node
 
 const Utils = preload("../../utils.notest.gd")
-const PreloadedScript = preload("./export_variable.notest.gd")
+const PreloadedGlobalClass = preload("./export_variable_global.notest.gd")
+const PreloadedUnnamedClass = preload("./export_variable_unnamed.notest.gd")
 
 # Built-in types.
 @export var test_weak_int = 1
@@ -24,7 +25,8 @@ const PreloadedScript = preload("./export_variable.notest.gd")
 
 # Global custom classes.
 @export var test_global_class: ExportVariableTest
-@export var test_preloaded_script: PreloadedScript
+@export var test_preloaded_global_class: PreloadedGlobalClass
+@export var test_preloaded_unnamed_class: PreloadedUnnamedClass # GH-93168
 
 # Arrays.
 @export var test_array: Array
diff --git a/modules/gdscript/tests/scripts/parser/features/export_variable.notest.gd b/modules/gdscript/tests/scripts/parser/features/export_variable.notest.gd
deleted file mode 100644
index 6d064351c1d..00000000000
--- a/modules/gdscript/tests/scripts/parser/features/export_variable.notest.gd
+++ /dev/null
@@ -1,2 +0,0 @@
-class_name ExportPreloadedClassTest
-extends Node
diff --git a/modules/gdscript/tests/scripts/parser/features/export_variable.out b/modules/gdscript/tests/scripts/parser/features/export_variable.out
index bb094e14b45..d10462bb8d8 100644
--- a/modules/gdscript/tests/scripts/parser/features/export_variable.out
+++ b/modules/gdscript/tests/scripts/parser/features/export_variable.out
@@ -25,8 +25,10 @@ var test_timer: Timer = null
   hint=NODE_TYPE hint_string="Timer" usage=DEFAULT|SCRIPT_VARIABLE class_name=&"Timer"
 var test_global_class: ExportVariableTest = null
   hint=NODE_TYPE hint_string="ExportVariableTest" usage=DEFAULT|SCRIPT_VARIABLE class_name=&"ExportVariableTest"
-var test_preloaded_script: ExportPreloadedClassTest = null
-  hint=NODE_TYPE hint_string="ExportPreloadedClassTest" usage=DEFAULT|SCRIPT_VARIABLE class_name=&"ExportPreloadedClassTest"
+var test_preloaded_global_class: ExportVariableTestGlobalClass = null
+  hint=NODE_TYPE hint_string="ExportVariableTestGlobalClass" usage=DEFAULT|SCRIPT_VARIABLE class_name=&"ExportVariableTestGlobalClass"
+var test_preloaded_unnamed_class: Node2D = null
+  hint=NODE_TYPE hint_string="Node2D" usage=DEFAULT|SCRIPT_VARIABLE class_name=&"Node2D"
 var test_array: Array = []
   hint=NONE hint_string="" usage=DEFAULT|SCRIPT_VARIABLE class_name=&""
 var test_array_bool: Array = Array[bool]([])
diff --git a/modules/gdscript/tests/scripts/parser/features/export_variable_global.notest.gd b/modules/gdscript/tests/scripts/parser/features/export_variable_global.notest.gd
new file mode 100644
index 00000000000..caa2ead2147
--- /dev/null
+++ b/modules/gdscript/tests/scripts/parser/features/export_variable_global.notest.gd
@@ -0,0 +1,2 @@
+class_name ExportVariableTestGlobalClass
+extends Node2D
diff --git a/modules/gdscript/tests/scripts/parser/features/export_variable_unnamed.notest.gd b/modules/gdscript/tests/scripts/parser/features/export_variable_unnamed.notest.gd
new file mode 100644
index 00000000000..e251cf8aee8
--- /dev/null
+++ b/modules/gdscript/tests/scripts/parser/features/export_variable_unnamed.notest.gd
@@ -0,0 +1 @@
+extends Node2D