GDScript: Allow use local constants as types

modules/gdscript/gdscript_analyzer.cpp

@@ -613,8 +613,45 @@ GDScriptParser::DataType GDScriptAnalyzer::resolve_datatype(GDScriptParser::Type
 		return result;
 	}
 
-	StringName first = p_type->type_chain[0]->name;
+	const GDScriptParser::IdentifierNode *first_id = p_type->type_chain[0];
+	StringName first = first_id->name;
+	bool type_found = false;
 
+	if (first_id->suite && first_id->suite->has_local(first)) {
+		const GDScriptParser::SuiteNode::Local &local = first_id->suite->get_local(first);
+		if (local.type == GDScriptParser::SuiteNode::Local::CONSTANT) {
+			result = local.get_datatype();
+			if (!result.is_set()) {
+				// Don't try to resolve it as the constant can be declared below.
+				push_error(vformat(R"(Local constant "%s" is not resolved at this point.)", first), first_id);
+				return bad_type;
+			}
+			if (result.is_meta_type) {
+				type_found = true;
+			} else if (Ref<Script>(local.constant->initializer->reduced_value).is_valid()) {
+				Ref<GDScript> gdscript = local.constant->initializer->reduced_value;
+				if (gdscript.is_valid()) {
+					Ref<GDScriptParserRef> ref = get_parser_for(gdscript->get_script_path());
+					if (ref->raise_status(GDScriptParserRef::INHERITANCE_SOLVED) != OK) {
+						push_error(vformat(R"(Could not parse script from "%s".)", gdscript->get_script_path()), first_id);
+						return bad_type;
+					}
+					result = ref->get_parser()->head->get_datatype();
+				} else {
+					result = make_script_meta_type(local.constant->initializer->reduced_value);
+				}
+				type_found = true;
+			} else {
+				push_error(vformat(R"(Local constant "%s" is not a valid type.)", first), first_id);
+				return bad_type;
+			}
+		} else {
+			push_error(vformat(R"(Local %s "%s" cannot be used as a type.)", local.get_name(), first), first_id);
+			return bad_type;
+		}
+	}
+
+	if (!type_found) {
 		if (first == SNAME("Variant")) {
 			if (p_type->type_chain.size() == 2) {
 				// May be nested enum.
@@ -751,6 +788,8 @@ GDScriptParser::DataType GDScriptAnalyzer::resolve_datatype(GDScriptParser::Type
 				}
 			}
 		}
+	}
+
 	if (!result.is_set()) {
 		push_error(vformat(R"(Could not find type "%s" in the current scope.)", first), p_type);
 		return bad_type;

modules/gdscript/gdscript_parser.cpp

@@ -2291,9 +2291,7 @@ GDScriptParser::ExpressionNode *GDScriptParser::parse_identifier(ExpressionNode
 	IdentifierNode *identifier = alloc_node<IdentifierNode>();
 	complete_extents(identifier);
 	identifier->name = previous.get_identifier();
-#ifdef DEBUG_ENABLED
 	identifier->suite = current_suite;
-#endif
 
 	if (current_suite != nullptr && current_suite->has_local(identifier->name)) {
 		const SuiteNode::Local &declaration = current_suite->get_local(identifier->name);
@@ -4283,7 +4281,7 @@ String GDScriptParser::SuiteNode::Local::get_name() const {
 		case SuiteNode::Local::FOR_VARIABLE:
 			return "for loop iterator";
 		case SuiteNode::Local::PATTERN_BIND:
-			return "pattern_bind";
+			return "pattern bind";
 		case SuiteNode::Local::UNDEFINED:
 			return "<undefined>";
 		default:

modules/gdscript/gdscript_parser.h

@@ -859,9 +859,7 @@ public:
 
 	struct IdentifierNode : public ExpressionNode {
 		StringName name;
-#ifdef DEBUG_ENABLED
 		SuiteNode *suite = nullptr; // The block in which the identifier is used.
-#endif
 
 		enum Source {
 			UNDEFINED_SOURCE,

modules/gdscript/tests/scripts/analyzer/errors/local_const_as_type_use_before_declared.gd

@@ -0,0 +1,5 @@
+enum MyEnum {}
+
+func test():
+	var e: E
+	const E = MyEnum

modules/gdscript/tests/scripts/analyzer/errors/local_const_as_type_use_before_declared.out

@@ -0,0 +1,2 @@
+GDTEST_ANALYZER_ERROR
+Local constant "E" is not resolved at this point.

modules/gdscript/tests/scripts/analyzer/errors/local_const_as_type_use_not_const.gd

@@ -0,0 +1,5 @@
+enum MyEnum {}
+
+func test():
+	var E = MyEnum
+	var e: E

modules/gdscript/tests/scripts/analyzer/errors/local_const_as_type_use_not_const.out

@@ -0,0 +1,2 @@
+GDTEST_ANALYZER_ERROR
+Local variable "E" cannot be used as a type.

modules/gdscript/tests/scripts/analyzer/errors/local_const_as_type_use_not_type.gd

@@ -0,0 +1,5 @@
+enum MyEnum {A}
+
+func test():
+	const E = MyEnum.A
+	var e: E

modules/gdscript/tests/scripts/analyzer/errors/local_const_as_type_use_not_type.out

@@ -0,0 +1,2 @@
+GDTEST_ANALYZER_ERROR
+Local constant "E" is not a valid type.

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

@@ -0,0 +1,41 @@
+class InnerClass:
+	enum InnerEnum {A = 2}
+	const INNER_CONST = "INNER_CONST"
+
+enum Enum {A = 1}
+
+const Other = preload("./local_const_as_type.notest.gd")
+
+func test():
+	const IC = InnerClass
+	const IE = IC.InnerEnum
+	const E = Enum
+	# Doesn't work in CI, but works in the editor. Looks like an unrelated bug. TODO: Investigate it.
+	# Error: Invalid call. Nonexistent function 'new' in base 'GDScript'.
+	var a1: IC = null # IC.new()
+	var a2: IE = IE.A
+	var a3: IC.InnerEnum = IE.A
+	var a4: E = E.A
+	print(a1.INNER_CONST)
+	print(a2)
+	print(a3)
+	print(a4)
+
+	const O = Other
+	const OV: Variant = Other # Removes metatype.
+	const OIC = O.InnerClass
+	const OIE = OIC.InnerEnum
+	const OE = O.Enum
+	var b: O = O.new()
+	@warning_ignore("unsafe_method_access")
+	var bv: OV = OV.new()
+	var b1: OIC = OIC.new()
+	var b2: OIE = OIE.A
+	var b3: O.InnerClass.InnerEnum = OIE.A
+	var b4: OE = OE.A
+	print(b.CONST)
+	print(bv.CONST)
+	print(b1.INNER_CONST)
+	print(b2)
+	print(b3)
+	print(b4)

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

@@ -0,0 +1,6 @@
+class InnerClass:
+	enum InnerEnum {A = 20}
+	const INNER_CONST = "OTHER_INNER_CONST"
+
+enum Enum {A = 10}
+const CONST = "OTHER_CONST"

modules/gdscript/tests/scripts/analyzer/features/local_const_as_type.out

@@ -0,0 +1,11 @@
+GDTEST_OK
+INNER_CONST
+2
+2
+1
+OTHER_CONST
+OTHER_CONST
+OTHER_INNER_CONST
+20
+20
+10