Add warning checks in GDScript analyzer

Reenable checking those when validating code.

core/script_language.h

@@ -294,7 +294,8 @@ public:
 
 	/* EDITOR FUNCTIONS */
 	struct Warning {
-		int line;
+		int start_line = -1, end_line = -1;
+		int leftmost_column = -1, rightmost_column = -1;
 		int code;
 		String string_code;
 		String message;

editor/plugins/script_text_editor.cpp

@@ -494,7 +494,7 @@ void ScriptTextEditor::_validate_script() {
 		ScriptLanguage::Warning w = E->get();
 
 		Dictionary ignore_meta;
-		ignore_meta["line"] = w.line;
+		ignore_meta["line"] = w.start_line;
 		ignore_meta["code"] = w.string_code.to_lower();
 		warnings_panel->push_cell();
 		warnings_panel->push_meta(ignore_meta);
@@ -506,9 +506,9 @@ void ScriptTextEditor::_validate_script() {
 		warnings_panel->pop(); // Cell.
 
 		warnings_panel->push_cell();
-		warnings_panel->push_meta(w.line - 1);
+		warnings_panel->push_meta(w.start_line - 1);
 		warnings_panel->push_color(warnings_panel->get_theme_color("warning_color", "Editor"));
-		warnings_panel->add_text(TTR("Line") + " " + itos(w.line));
+		warnings_panel->add_text(TTR("Line") + " " + itos(w.start_line));
 		warnings_panel->add_text(" (" + w.string_code + "):");
 		warnings_panel->pop(); // Color.
 		warnings_panel->pop(); // Meta goto.

modules/gdscript/gdscript.cpp

@@ -43,6 +43,7 @@
 #include "gdscript_cache.h"
 #include "gdscript_compiler.h"
 #include "gdscript_parser.h"
+#include "gdscript_warning.h"
 
 ///////////////////////////
 
@@ -469,10 +470,9 @@ bool GDScript::_update_exports(bool *r_err, bool p_recursive_call) {
 						}
 
 						members_cache.push_back(member.variable->export_info);
-						// FIXME: Get variable's default value in non-literal cases.
 						Variant default_value;
-						if (member.variable->initializer != nullptr && member.variable->initializer->type == GDScriptParser::Node::LITERAL) {
+						if (member.variable->initializer->is_constant) {
-							default_value = static_cast<const GDScriptParser::LiteralNode *>(member.variable->initializer)->value;
+							default_value = member.variable->initializer->reduced_value;
 						}
 						member_default_values_cache[member.variable->identifier->name] = default_value;
 					} break;
@@ -637,14 +637,13 @@ Error GDScript::reload(bool p_keep_state) {
 		}
 	}
 #ifdef DEBUG_ENABLED
-	// FIXME: Add warnings.
+	for (const List<GDScriptWarning>::Element *E = parser.get_warnings().front(); E; E = E->next()) {
-	// for (const List<GDScriptWarning>::Element *E = parser.get_warnings().front(); E; E = E->next()) {
+		const GDScriptWarning &warning = E->get();
-	// 	const GDScriptWarning &warning = E->get();
+		if (EngineDebugger::is_active()) {
-	// 	if (EngineDebugger::is_active()) {
+			Vector<ScriptLanguage::StackInfo> si;
-	// 		Vector<ScriptLanguage::StackInfo> si;
+			EngineDebugger::get_script_debugger()->send_error("", get_path(), warning.start_line, warning.get_name(), warning.get_message(), ERR_HANDLER_WARNING, si);
-	// 		EngineDebugger::get_script_debugger()->send_error("", get_path(), warning.line, warning.get_name(), warning.get_message(), ERR_HANDLER_WARNING, si);
+		}
-	// 	}
+	}
-	// }
 #endif
 
 	valid = true;
@@ -2044,7 +2043,7 @@ GDScriptLanguage::GDScriptLanguage() {
 	GLOBAL_DEF("debug/gdscript/completion/autocomplete_setters_and_getters", false);
 	for (int i = 0; i < (int)GDScriptWarning::WARNING_MAX; i++) {
 		String warning = GDScriptWarning::get_name_from_code((GDScriptWarning::Code)i).to_lower();
-		bool default_enabled = !warning.begins_with("unsafe_") && i != GDScriptWarning::UNUSED_CLASS_VARIABLE;
+		bool default_enabled = !warning.begins_with("unsafe_");
 		GLOBAL_DEF("debug/gdscript/warnings/" + warning, default_enabled);
 	}
 #endif // DEBUG_ENABLED

modules/gdscript/gdscript.h

@@ -303,52 +303,6 @@ public:
 	~GDScriptInstance();
 };
 
-#ifdef DEBUG_ENABLED
-struct GDScriptWarning {
-	enum Code {
-		UNASSIGNED_VARIABLE, // Variable used but never assigned
-		UNASSIGNED_VARIABLE_OP_ASSIGN, // Variable never assigned but used in an assignment operation (+=, *=, etc)
-		UNUSED_VARIABLE, // Local variable is declared but never used
-		SHADOWED_VARIABLE, // Variable name shadowed by other variable
-		UNUSED_CLASS_VARIABLE, // Class variable is declared but never used in the file
-		UNUSED_ARGUMENT, // Function argument is never used
-		UNREACHABLE_CODE, // Code after a return statement
-		STANDALONE_EXPRESSION, // Expression not assigned to a variable
-		VOID_ASSIGNMENT, // Function returns void but it's assigned to a variable
-		NARROWING_CONVERSION, // Float value into an integer slot, precision is lost
-		FUNCTION_MAY_YIELD, // Typed assign of function call that yields (it may return a function state)
-		VARIABLE_CONFLICTS_FUNCTION, // Variable has the same name of a function
-		FUNCTION_CONFLICTS_VARIABLE, // Function has the same name of a variable
-		FUNCTION_CONFLICTS_CONSTANT, // Function has the same name of a constant
-		INCOMPATIBLE_TERNARY, // Possible values of a ternary if are not mutually compatible
-		UNUSED_SIGNAL, // Signal is defined but never emitted
-		RETURN_VALUE_DISCARDED, // Function call returns something but the value isn't used
-		PROPERTY_USED_AS_FUNCTION, // Function not found, but there's a property with the same name
-		CONSTANT_USED_AS_FUNCTION, // Function not found, but there's a constant with the same name
-		FUNCTION_USED_AS_PROPERTY, // Property not found, but there's a function with the same name
-		INTEGER_DIVISION, // Integer divide by integer, decimal part is discarded
-		UNSAFE_PROPERTY_ACCESS, // Property not found in the detected type (but can be in subtypes)
-		UNSAFE_METHOD_ACCESS, // Function not found in the detected type (but can be in subtypes)
-		UNSAFE_CAST, // Cast used in an unknown type
-		UNSAFE_CALL_ARGUMENT, // Function call argument is of a supertype of the require argument
-		DEPRECATED_KEYWORD, // The keyword is deprecated and should be replaced
-		STANDALONE_TERNARY, // Return value of ternary expression is discarded
-		WARNING_MAX,
-	};
-
-	Code code = WARNING_MAX;
-	Vector<String> symbols;
-	int line = -1;
-
-	String get_name() const;
-	String get_message() const;
-	static String get_name_from_code(Code p_code);
-	static Code get_code_from_name(const String &p_name);
-
-	GDScriptWarning() {}
-};
-#endif // DEBUG_ENABLED
-
 class GDScriptLanguage : public ScriptLanguage {
 	friend class GDScriptFunctionState;
 

modules/gdscript/gdscript_analyzer.cpp

@@ -259,7 +259,7 @@ Error GDScriptAnalyzer::resolve_inheritance(GDScriptParser::ClassNode *p_class,
 	return OK;
 }
 
-GDScriptParser::DataType GDScriptAnalyzer::resolve_datatype(const GDScriptParser::TypeNode *p_type) {
+GDScriptParser::DataType GDScriptAnalyzer::resolve_datatype(GDScriptParser::TypeNode *p_type) {
 	GDScriptParser::DataType result;
 
 	if (p_type == nullptr) {
@@ -274,12 +274,22 @@ GDScriptParser::DataType GDScriptAnalyzer::resolve_datatype(const GDScriptParser
 		// void.
 		result.kind = GDScriptParser::DataType::BUILTIN;
 		result.builtin_type = Variant::NIL;
+		p_type->set_datatype(result);
 		return result;
 	}
 
 	StringName first = p_type->type_chain[0]->name;
 
-	if (GDScriptParser::get_builtin_type(first) != Variant::NIL) {
+	if (first == "Variant") {
+		result.kind = GDScriptParser::DataType::VARIANT;
+		if (p_type->type_chain.size() > 1) {
+			push_error(R"("Variant" type don't contain nested types.)", p_type->type_chain[1]);
+			return GDScriptParser::DataType();
+		}
+		return result;
+	}
+
+	if (GDScriptParser::get_builtin_type(first) < Variant::VARIANT_MAX) {
 		// Built-in types.
 		if (p_type->type_chain.size() > 1) {
 			push_error(R"(Built-in types don't contain nested types.)", p_type->type_chain[1]);
@@ -363,6 +373,7 @@ GDScriptParser::DataType GDScriptAnalyzer::resolve_datatype(const GDScriptParser
 		}
 	}
 
+	p_type->set_datatype(result);
 	return result;
 }
 
@@ -385,17 +396,34 @@ void GDScriptAnalyzer::resolve_class_interface(GDScriptParser::ClassNode *p_clas
 				datatype.type_source = GDScriptParser::DataType::UNDETECTED;
 
 				if (member.variable->initializer != nullptr) {
+					member.variable->set_datatype(datatype); // Allow recursive usage.
 					reduce_expression(member.variable->initializer);
 					datatype = member.variable->initializer->get_datatype();
 				}
 
 				if (member.variable->datatype_specifier != nullptr) {
 					datatype = resolve_datatype(member.variable->datatype_specifier);
-				} else if (member.variable->infer_datatype) {
+
 					if (member.variable->initializer != nullptr) {
-						push_error(vformat(R"(Cannot infer the type of "%s" variable because there's no default value.)", member.variable->identifier), member.variable->identifier);
+						if (!is_type_compatible(datatype, member.variable->initializer->get_datatype(), true)) {
+							push_error(vformat(R"(Value of type "%s" cannot be assigned to variable of type "%s".)", member.variable->initializer->get_datatype().to_string(), datatype.to_string()), member.variable->initializer);
+						} else if (datatype.builtin_type == Variant::INT && member.variable->initializer->get_datatype().builtin_type == Variant::FLOAT) {
+							parser->push_warning(member.variable->initializer, GDScriptWarning::NARROWING_CONVERSION);
+						}
+						if (member.variable->initializer->get_datatype().is_variant()) {
+							// TODO: Warn unsafe assign.
+							mark_node_unsafe(member.variable->initializer);
+						}
+					}
+				} else if (member.variable->infer_datatype) {
+					if (member.variable->initializer == nullptr) {
+						push_error(vformat(R"(Cannot infer the type of "%s" variable because there's no default value.)", member.variable->identifier->name), member.variable->identifier);
 					} else if (!datatype.is_set() || datatype.has_no_type()) {
-						push_error(vformat(R"(Cannot infer the type of "%s" variable because the default value doesn't have a set type.)", member.variable->identifier), member.variable->initializer);
+						push_error(vformat(R"(Cannot infer the type of "%s" variable because the initial value doesn't have a set type.)", member.variable->identifier->name), member.variable->initializer);
+					} else if (datatype.is_variant()) {
+						push_error(vformat(R"(Cannot infer the type of "%s" variable because the initial value is Variant. Use explicit "Variant" type if this is intended.)", member.variable->identifier->name), member.variable->initializer);
+					} else if (datatype.builtin_type == Variant::NIL) {
+						push_error(vformat(R"(Cannot infer the type of "%s" variable because the initial value is "null".)", member.variable->identifier->name), member.variable->initializer);
 					}
 				}
 
@@ -430,7 +458,22 @@ void GDScriptAnalyzer::resolve_class_interface(GDScriptParser::ClassNode *p_clas
 				if (!member.constant->initializer->is_constant) {
 					push_error(R"(Initializer for a constant must be a constant expression.)", member.constant->initializer);
 				}
-				member.constant->set_datatype(member.constant->initializer->get_datatype());
+
+				GDScriptParser::DataType datatype = member.constant->get_datatype();
+
+				if (member.constant->datatype_specifier != nullptr) {
+					datatype = resolve_datatype(member.constant->datatype_specifier);
+
+					if (!is_type_compatible(datatype, member.constant->initializer->get_datatype(), true)) {
+						push_error(vformat(R"(Value of type "%s" cannot be initialized to constant of type "%s".)", member.constant->initializer->get_datatype().to_string(), datatype.to_string()), member.constant->initializer);
+					} else if (datatype.builtin_type == Variant::INT && member.constant->initializer->get_datatype().builtin_type == Variant::FLOAT) {
+						parser->push_warning(member.constant->initializer, GDScriptWarning::NARROWING_CONVERSION);
+					}
+				}
+
+				datatype.is_constant = true;
+
+				member.constant->set_datatype(datatype);
 			} break;
 			case GDScriptParser::ClassNode::Member::SIGNAL: {
 				for (int j = 0; j < member.signal->parameters.size(); j++) {
@@ -508,6 +551,17 @@ void GDScriptAnalyzer::resolve_class_body(GDScriptParser::ClassNode *p_class) {
 
 		resolve_class_body(member.m_class);
 	}
+
+	// Check unused variables.
+	for (int i = 0; i < p_class->members.size(); i++) {
+		GDScriptParser::ClassNode::Member member = p_class->members[i];
+		if (member.type != GDScriptParser::ClassNode::Member::VARIABLE) {
+			continue;
+		}
+		if (member.variable->usages == 0 && String(member.variable->identifier->name).begins_with("_")) {
+			parser->push_warning(member.variable->identifier, GDScriptWarning::UNUSED_PRIVATE_CLASS_VARIABLE, member.variable->identifier->name);
+		}
+	}
 }
 
 void GDScriptAnalyzer::resolve_node(GDScriptParser::Node *p_node) {
@@ -610,6 +664,11 @@ void GDScriptAnalyzer::resolve_function_signature(GDScriptParser::FunctionNode *
 
 	for (int i = 0; i < p_function->parameters.size(); i++) {
 		resolve_pararameter(p_function->parameters[i]);
+		if (p_function->parameters[i]->usages == 0 && !String(p_function->parameters[i]->identifier->name).begins_with("_")) {
+			parser->push_warning(p_function->parameters[i]->identifier, GDScriptWarning::UNUSED_PARAMETER, p_function->identifier->name, p_function->parameters[i]->identifier->name);
+		}
+
+		is_shadowing(p_function->parameters[i]->identifier, "function parameter");
 	}
 
 	p_function->set_datatype(resolve_datatype(p_function->return_type));
@@ -630,10 +689,14 @@ void GDScriptAnalyzer::resolve_function_body(GDScriptParser::FunctionNode *p_fun
 
 	GDScriptParser::DataType return_type = p_function->body->get_datatype();
 
-	if (p_function->get_datatype().type_source == GDScriptParser::DataType::UNDETECTED && return_type.is_set()) {
+	if (p_function->get_datatype().has_no_type() && return_type.is_set()) {
 		// Use the suite inferred type if return isn't explicitly set.
 		return_type.type_source = GDScriptParser::DataType::INFERRED;
 		p_function->set_datatype(p_function->body->get_datatype());
+	} else if (p_function->get_datatype().is_hard_type() && (p_function->get_datatype().kind != GDScriptParser::DataType::BUILTIN || p_function->get_datatype().builtin_type != Variant::NIL)) {
+		if (!p_function->body->has_return) {
+			push_error(R"(Not all code paths return a value.)", p_function);
+		}
 	}
 
 	parser->current_function = previous_function;
@@ -758,6 +821,8 @@ void GDScriptAnalyzer::resolve_for(GDScriptParser::ForNode *p_for) {
 
 	resolve_suite(p_for->loop);
 	p_for->set_datatype(p_for->loop->get_datatype());
+
+	is_shadowing(p_for->variable, R"("for" iterator variable)");
 }
 
 void GDScriptAnalyzer::resolve_while(GDScriptParser::WhileNode *p_while) {
@@ -769,6 +834,7 @@ void GDScriptAnalyzer::resolve_while(GDScriptParser::WhileNode *p_while) {
 
 void GDScriptAnalyzer::resolve_variable(GDScriptParser::VariableNode *p_variable) {
 	GDScriptParser::DataType type;
+	type.kind = GDScriptParser::DataType::VARIANT; // By default.
 
 	if (p_variable->initializer != nullptr) {
 		reduce_expression(p_variable->initializer);
@@ -780,19 +846,49 @@ void GDScriptAnalyzer::resolve_variable(GDScriptParser::VariableNode *p_variable
 			if (type.has_no_type()) {
 				push_error(vformat(R"(Could not infer the type of the variable "%s" because the initial value does not have a set type.)", p_variable->identifier->name), p_variable->initializer);
 			} else if (type.is_variant()) {
-				push_error(vformat(R"(Could not infer the type of the variable "%s" because the initial value is a variant.)", p_variable->identifier->name), p_variable->initializer);
+				push_error(vformat(R"(Could not infer the type of the variable "%s" because the initial value is a variant. Use explicit "Variant" type if this is intended.)", p_variable->identifier->name), p_variable->initializer);
+			} else if (type.builtin_type == Variant::NIL) {
+				push_error(vformat(R"(Could not infer the type of the variable "%s" because the initial value is "null".)", p_variable->identifier->name), p_variable->initializer);
 			}
 		} else {
 			type.type_source = GDScriptParser::DataType::INFERRED;
 		}
+		if (p_variable->initializer->type == GDScriptParser::Node::CALL && type.kind == GDScriptParser::DataType::BUILTIN && type.builtin_type == Variant::NIL) {
+			parser->push_warning(p_variable->initializer, GDScriptWarning::VOID_ASSIGNMENT, static_cast<GDScriptParser::CallNode *>(p_variable->initializer)->function_name);
+		}
 	}
 
 	if (p_variable->datatype_specifier != nullptr) {
 		type = resolve_datatype(p_variable->datatype_specifier);
+
+		if (p_variable->initializer != nullptr) {
+			if (!is_type_compatible(type, p_variable->initializer->get_datatype(), true)) {
+				push_error(vformat(R"(Value of type "%s" cannot be assigned to variable of type "%s".)", p_variable->initializer->get_datatype().to_string(), type.to_string()), p_variable->initializer);
+			} else if (type.builtin_type == Variant::INT && p_variable->initializer->get_datatype().builtin_type == Variant::FLOAT) {
+				parser->push_warning(p_variable->initializer, GDScriptWarning::NARROWING_CONVERSION);
+			}
+			if (p_variable->initializer->get_datatype().is_variant()) {
+				// TODO: Warn unsafe assign.
+				mark_node_unsafe(p_variable->initializer);
+			}
+		}
+	} else if (p_variable->infer_datatype) {
+		if (type.has_no_type()) {
+			push_error(vformat(R"(Cannot infer the type of variable "%s" because the initial value doesn't have a set type.)", p_variable->identifier->name), p_variable->identifier);
+		}
+		type.type_source = GDScriptParser::DataType::ANNOTATED_INFERRED;
 	}
 
 	type.is_constant = false;
 	p_variable->set_datatype(type);
+
+	if (p_variable->usages == 0 && !String(p_variable->identifier->name).begins_with("_")) {
+		parser->push_warning(p_variable, GDScriptWarning::UNUSED_VARIABLE, p_variable->identifier->name);
+	} else if (p_variable->assignments == 0) {
+		parser->push_warning(p_variable, GDScriptWarning::UNASSIGNED_VARIABLE, p_variable->identifier->name);
+	}
+
+	is_shadowing(p_variable->identifier, "variable");
 }
 
 void GDScriptAnalyzer::resolve_constant(GDScriptParser::ConstantNode *p_constant) {
@@ -806,25 +902,50 @@ void GDScriptAnalyzer::resolve_constant(GDScriptParser::ConstantNode *p_constant
 
 	type = p_constant->initializer->get_datatype();
 
+	if (p_constant->initializer->type == GDScriptParser::Node::CALL && type.kind == GDScriptParser::DataType::BUILTIN && type.builtin_type == Variant::NIL) {
+		parser->push_warning(p_constant->initializer, GDScriptWarning::VOID_ASSIGNMENT, static_cast<GDScriptParser::CallNode *>(p_constant->initializer)->function_name);
+	}
+
 	if (p_constant->datatype_specifier != nullptr) {
 		GDScriptParser::DataType explicit_type = resolve_datatype(p_constant->datatype_specifier);
 		if (!is_type_compatible(explicit_type, type)) {
 			push_error(vformat(R"(Assigned value for constant "%s" has type %s which is not compatible with defined type %s.)", p_constant->identifier->name, type.to_string(), explicit_type.to_string()), p_constant->initializer);
+		} else if (explicit_type.builtin_type == Variant::INT && type.builtin_type == Variant::FLOAT) {
+			parser->push_warning(p_constant->initializer, GDScriptWarning::NARROWING_CONVERSION);
 		}
 		type = explicit_type;
+	} else if (p_constant->infer_datatype) {
+		if (type.has_no_type()) {
+			push_error(vformat(R"(Cannot infer the type of constant "%s" because the initial value doesn't have a set type.)", p_constant->identifier->name), p_constant->identifier);
+		}
+		type.type_source = GDScriptParser::DataType::ANNOTATED_INFERRED;
 	}
 
 	type.is_constant = true;
 	p_constant->set_datatype(type);
+
+	if (p_constant->usages == 0) {
+		parser->push_warning(p_constant, GDScriptWarning::UNUSED_LOCAL_CONSTANT, p_constant->identifier->name);
+	}
+
+	is_shadowing(p_constant->identifier, "constant");
 }
 
 void GDScriptAnalyzer::resolve_assert(GDScriptParser::AssertNode *p_assert) {
 	reduce_expression(p_assert->condition);
-	reduce_literal(p_assert->message);
+	if (p_assert->message != nullptr) {
+		reduce_literal(p_assert->message);
+	}
 
 	p_assert->set_datatype(p_assert->condition->get_datatype());
 
-	// TODO: Warn when expression is constantly true or false.
+	if (p_assert->condition->is_constant) {
+		if (p_assert->condition->reduced_value.booleanize()) {
+			parser->push_warning(p_assert->condition, GDScriptWarning::ASSERT_ALWAYS_TRUE);
+		} else {
+			parser->push_warning(p_assert->condition, GDScriptWarning::ASSERT_ALWAYS_FALSE);
+		}
+	}
 }
 
 void GDScriptAnalyzer::resolve_match(GDScriptParser::MatchNode *p_match) {
@@ -869,6 +990,10 @@ void GDScriptAnalyzer::resolve_match_pattern(GDScriptParser::PatternNode *p_matc
 				result.kind = GDScriptParser::DataType::VARIANT;
 			}
 			p_match_pattern->bind->set_datatype(result);
+			is_shadowing(p_match_pattern->bind, "pattern bind");
+			if (p_match_pattern->bind->usages == 0) {
+				parser->push_warning(p_match_pattern->bind, GDScriptWarning::UNASSIGNED_VARIABLE, p_match_pattern->bind->name);
+			}
 			break;
 		case GDScriptParser::PatternNode::PT_ARRAY:
 			for (int i = 0; i < p_match_pattern->array.size(); i++) {
@@ -904,9 +1029,6 @@ void GDScriptAnalyzer::resolve_pararameter(GDScriptParser::ParameterNode *p_para
 
 	if (p_parameter->default_value != nullptr) {
 		reduce_expression(p_parameter->default_value);
-		if (p_parameter->default_value->is_constant) {
-			push_error(vformat(R"(Default value for paramater "%s" is not a constant.)", p_parameter->identifier->name), p_parameter->default_value);
-		}
 		result = p_parameter->default_value->get_datatype();
 		result.type_source = GDScriptParser::DataType::INFERRED;
 	}
@@ -916,7 +1038,7 @@ void GDScriptAnalyzer::resolve_pararameter(GDScriptParser::ParameterNode *p_para
 
 		if (p_parameter->default_value != nullptr) {
 			if (!is_type_compatible(p_parameter->datatype_specifier->get_datatype(), p_parameter->default_value->get_datatype())) {
-				push_error(vformat(R"(Type of default value for parameter "%s" is not compatible with paremeter type.)", p_parameter->identifier->name), p_parameter->default_value);
+				push_error(vformat(R"(Type of default value for parameter "%s" (%s) is not compatible with paremeter type (%s).)", p_parameter->identifier->name, p_parameter->default_value->get_datatype().to_string(), p_parameter->datatype_specifier->get_datatype().to_string()), p_parameter->default_value);
 			}
 		}
 
@@ -940,6 +1062,23 @@ void GDScriptAnalyzer::resolve_return(GDScriptParser::ReturnNode *p_return) {
 		result.is_constant = true;
 	}
 
+	GDScriptParser::DataType function_type = parser->current_function->get_datatype();
+	if (function_type.is_hard_type()) {
+		if (!is_type_compatible(function_type, result)) {
+			// Try other way. Okay but not safe.
+			if (!is_type_compatible(result, function_type)) {
+				push_error(vformat(R"(Cannot return value of type "%s" because the function return type is "%s".)", result.to_string(), function_type.to_string()), p_return);
+			} else {
+				// TODO: Add warning.
+				mark_node_unsafe(p_return);
+			}
+		} else if (function_type.builtin_type == Variant::INT && result.builtin_type == Variant::FLOAT) {
+			parser->push_warning(p_return, GDScriptWarning::NARROWING_CONVERSION);
+		} else if (result.is_variant()) {
+			mark_node_unsafe(p_return);
+		}
+	}
+
 	p_return->set_datatype(result);
 }
 
@@ -1112,10 +1251,22 @@ void GDScriptAnalyzer::reduce_assignment(GDScriptParser::AssignmentNode *p_assig
 				break;
 		}
 	}
+
+	GDScriptParser::DataType assignee_type = p_assignment->assignee->get_datatype();
+	GDScriptParser::DataType assigned_type = p_assignment->assigned_value->get_datatype();
+	if (p_assignment->assigned_value->type == GDScriptParser::Node::CALL && assigned_type.kind == GDScriptParser::DataType::BUILTIN && assigned_type.builtin_type == Variant::NIL) {
+		parser->push_warning(p_assignment->assigned_value, GDScriptWarning::VOID_ASSIGNMENT, static_cast<GDScriptParser::CallNode *>(p_assignment->assigned_value)->function_name);
+	} else if (assignee_type.is_hard_type() && assignee_type.builtin_type == Variant::INT && assigned_type.builtin_type == Variant::FLOAT) {
+		parser->push_warning(p_assignment->assigned_value, GDScriptWarning::NARROWING_CONVERSION);
+	}
 }
 
 void GDScriptAnalyzer::reduce_await(GDScriptParser::AwaitNode *p_await) {
-	reduce_expression(p_await->to_await);
+	if (p_await->to_await->type == GDScriptParser::Node::CALL) {
+		reduce_call(static_cast<GDScriptParser::CallNode *>(p_await->to_await), true);
+	} else {
+		reduce_expression(p_await->to_await);
+	}
 
 	p_await->is_constant = p_await->to_await->is_constant;
 	p_await->reduced_value = p_await->to_await->reduced_value;
@@ -1124,7 +1275,9 @@ void GDScriptAnalyzer::reduce_await(GDScriptParser::AwaitNode *p_await) {
 
 	p_await->set_datatype(awaiting_type);
 
-	// TODO: Add warning if await is redundant.
+	if (!awaiting_type.is_coroutine && awaiting_type.builtin_type != Variant::SIGNAL) {
+		parser->push_warning(p_await, GDScriptWarning::REDUNDANT_AWAIT);
+	}
 }
 
 void GDScriptAnalyzer::reduce_binary_op(GDScriptParser::BinaryOpNode *p_binary_op) {
@@ -1133,13 +1286,20 @@ void GDScriptAnalyzer::reduce_binary_op(GDScriptParser::BinaryOpNode *p_binary_o
 
 	// TODO: Right operand must be a valid type with the `is` operator. Need to check here.
 
+	GDScriptParser::DataType left_type = p_binary_op->left_operand->get_datatype();
+	GDScriptParser::DataType right_type = p_binary_op->right_operand->get_datatype();
+
+	if (p_binary_op->variant_op == Variant::OP_DIVIDE && left_type.builtin_type == Variant::INT && right_type.builtin_type == Variant::INT) {
+		parser->push_warning(p_binary_op, GDScriptWarning::INTEGER_DIVISION);
+	}
+
 	if (p_binary_op->left_operand->is_constant && p_binary_op->right_operand->is_constant) {
 		p_binary_op->is_constant = true;
 		if (p_binary_op->variant_op < Variant::OP_MAX) {
 			p_binary_op->reduced_value = Variant::evaluate(p_binary_op->variant_op, p_binary_op->left_operand->reduced_value, p_binary_op->right_operand->reduced_value);
 		} else {
 			if (p_binary_op->operation == GDScriptParser::BinaryOpNode::OP_TYPE_TEST) {
-				GDScriptParser::DataType test_type = p_binary_op->right_operand->get_datatype();
+				GDScriptParser::DataType test_type = right_type;
 				test_type.is_meta_type = false;
 
 				if (!is_type_compatible(test_type, p_binary_op->left_operand->get_datatype(), false)) {
@@ -1153,26 +1313,27 @@ void GDScriptAnalyzer::reduce_binary_op(GDScriptParser::BinaryOpNode *p_binary_o
 			}
 		}
 		p_binary_op->set_datatype(type_from_variant(p_binary_op->reduced_value));
+
 		return;
 	}
 
 	GDScriptParser::DataType result;
 
-	if (p_binary_op->left_operand->get_datatype().is_variant() || p_binary_op->right_operand->get_datatype().is_variant()) {
+	if (left_type.is_variant() || right_type.is_variant()) {
 		// Cannot infer type because one operand can be anything.
 		result.kind = GDScriptParser::DataType::VARIANT;
 		mark_node_unsafe(p_binary_op);
 	} else {
 		if (p_binary_op->variant_op < Variant::OP_MAX) {
 			bool valid = false;
-			result = get_operation_type(p_binary_op->variant_op, p_binary_op->left_operand->get_datatype(), p_binary_op->right_operand->get_datatype(), valid);
+			result = get_operation_type(p_binary_op->variant_op, p_binary_op->left_operand->get_datatype(), right_type, valid);
 
 			if (!valid) {
-				push_error(vformat(R"(Invalid operands "%s" and "%s" for "%s" operator.)", p_binary_op->left_operand->get_datatype().to_string(), p_binary_op->right_operand->get_datatype().to_string(), Variant::get_operator_name(p_binary_op->variant_op)), p_binary_op);
+				push_error(vformat(R"(Invalid operands "%s" and "%s" for "%s" operator.)", p_binary_op->left_operand->get_datatype().to_string(), right_type.to_string(), Variant::get_operator_name(p_binary_op->variant_op)), p_binary_op);
 			}
 		} else {
 			if (p_binary_op->operation == GDScriptParser::BinaryOpNode::OP_TYPE_TEST) {
-				GDScriptParser::DataType test_type = p_binary_op->right_operand->get_datatype();
+				GDScriptParser::DataType test_type = right_type;
 				test_type.is_meta_type = false;
 
 				if (!is_type_compatible(test_type, p_binary_op->left_operand->get_datatype(), false)) {
@@ -1180,6 +1341,7 @@ void GDScriptAnalyzer::reduce_binary_op(GDScriptParser::BinaryOpNode *p_binary_o
 						push_error(vformat(R"(Expression is of type "%s" so it can't be of type "%s".)", p_binary_op->left_operand->get_datatype().to_string(), test_type.to_string()), p_binary_op->left_operand);
 					} else {
 						// TODO: Warning.
+						mark_node_unsafe(p_binary_op);
 					}
 				}
 
@@ -1196,7 +1358,7 @@ void GDScriptAnalyzer::reduce_binary_op(GDScriptParser::BinaryOpNode *p_binary_o
 	p_binary_op->set_datatype(result);
 }
 
-void GDScriptAnalyzer::reduce_call(GDScriptParser::CallNode *p_call) {
+void GDScriptAnalyzer::reduce_call(GDScriptParser::CallNode *p_call, bool is_await) {
 	bool all_is_constant = true;
 	for (int i = 0; i < p_call->arguments.size(); i++) {
 		reduce_expression(p_call->arguments[i]);
@@ -1300,7 +1462,9 @@ void GDScriptAnalyzer::reduce_call(GDScriptParser::CallNode *p_call) {
 							types_match = false;
 							break;
 						} else {
-							// TODO: Check narrowing conversion.
+							if (par_type.builtin_type == Variant::INT && p_call->arguments[i]->get_datatype().builtin_type == Variant::FLOAT) {
+								parser->push_warning(p_call, GDScriptWarning::NARROWING_CONVERSION, p_call->function_name);
+							}
 						}
 					}
 
@@ -1364,13 +1528,13 @@ void GDScriptAnalyzer::reduce_call(GDScriptParser::CallNode *p_call) {
 			} else {
 				validate_call_arg(function_info, p_call);
 			}
+			p_call->set_datatype(type_from_property(function_info.return_val));
 			return;
 		}
 	}
 
 	GDScriptParser::DataType base_type;
-	GDScriptParser::DataType result;
+	call_type.kind = GDScriptParser::DataType::VARIANT;
-	result.kind = GDScriptParser::DataType::VARIANT;
 	bool is_self = false;
 
 	if (p_call->is_super) {
@@ -1382,9 +1546,9 @@ void GDScriptAnalyzer::reduce_call(GDScriptParser::CallNode *p_call) {
 	} else if (p_call->callee->type == GDScriptParser::Node::SUBSCRIPT) {
 		GDScriptParser::SubscriptNode *subscript = static_cast<GDScriptParser::SubscriptNode *>(p_call->callee);
 		if (!subscript->is_attribute) {
-			// Invalid call.
+			// Invalid call. Error already sent in parser.
 			// TODO: Could check if Callable here.
-			p_call->set_datatype(result);
+			p_call->set_datatype(call_type);
 			mark_node_unsafe(p_call);
 			return;
 		}
@@ -1392,8 +1556,9 @@ void GDScriptAnalyzer::reduce_call(GDScriptParser::CallNode *p_call) {
 
 		base_type = subscript->base->get_datatype();
 	} else {
+		// Invalid call. Error already sent in parser.
 		// TODO: Could check if Callable here too.
-		p_call->set_datatype(result);
+		p_call->set_datatype(call_type);
 		mark_node_unsafe(p_call);
 		return;
 	}
@@ -1411,13 +1576,43 @@ void GDScriptAnalyzer::reduce_call(GDScriptParser::CallNode *p_call) {
 			push_error(vformat(R"*(Cannot call non-static function "%s()" from static function "%s()".)*", p_call->function_name, parser->current_function->identifier->name), p_call->callee);
 		}
 
-		result = return_type;
+		call_type = return_type;
 	} else {
-		String base_name = is_self && !p_call->is_super ? "self" : base_type.to_string();
+		// Check if the name exists as something else.
-		push_error(vformat(R"*(Function "%s()" not found in base %s.)*", p_call->function_name, base_name), p_call->is_super ? p_call : p_call->callee);
+		bool found = false;
+		if (!p_call->is_super) {
+			GDScriptParser::IdentifierNode *callee_id;
+			if (p_call->callee->type == GDScriptParser::Node::IDENTIFIER) {
+				callee_id = static_cast<GDScriptParser::IdentifierNode *>(p_call->callee);
+			} else {
+				// Can only be attribute.
+				callee_id = static_cast<GDScriptParser::SubscriptNode *>(p_call->callee)->attribute;
+			}
+			reduce_identifier_from_base(callee_id, &base_type);
+			GDScriptParser::DataType callee_type = callee_id->get_datatype();
+			if (callee_type.is_set() && !callee_type.is_variant()) {
+				found = true;
+				if (callee_type.builtin_type == Variant::CALLABLE) {
+					push_error(vformat(R"*(Name "%s" is a Callable. You can call it with "%s.call()" instead.)*", p_call->function_name, p_call->function_name), p_call->callee);
+				} else {
+					push_error(vformat(R"*(Name "%s" called as a function but is a "%s".)*", p_call->function_name, callee_type.to_string()), p_call->callee);
+				}
+			} else if (!is_self) {
+				parser->push_warning(p_call, GDScriptWarning::UNSAFE_METHOD_ACCESS, p_call->function_name, base_type.to_string());
+				mark_node_unsafe(p_call);
+			}
+		}
+		if (!found && is_self) {
+			String base_name = is_self && !p_call->is_super ? "self" : base_type.to_string();
+			push_error(vformat(R"*(Function "%s()" not found in base %s.)*", p_call->function_name, base_name), p_call->is_super ? p_call : p_call->callee);
+		}
 	}
 
-	p_call->set_datatype(result);
+	if (call_type.is_coroutine && !is_await) {
+		push_error(vformat(R"*(Function "%s()" is a coroutine, so it must be called with "await".)*", p_call->function_name), p_call->callee);
+	}
+
+	p_call->set_datatype(call_type);
 }
 
 void GDScriptAnalyzer::reduce_cast(GDScriptParser::CastNode *p_cast) {
@@ -1449,11 +1644,13 @@ void GDScriptAnalyzer::reduce_cast(GDScriptParser::CastNode *p_cast) {
 				if (!valid) {
 					push_error(vformat(R"(Invalid cast. Cannot convert from "%s" to "%s".)", op_type.to_string(), cast_type.to_string()), p_cast->cast_type);
 				}
-			} else {
-				mark_node_unsafe(p_cast);
 			}
 		}
 	}
+	if (p_cast->operand->get_datatype().is_variant()) {
+		parser->push_warning(p_cast, GDScriptWarning::UNSAFE_CAST, cast_type.to_string());
+		mark_node_unsafe(p_cast);
+	}
 
 	// TODO: Perform cast on constants.
 }
@@ -1559,6 +1756,8 @@ void GDScriptAnalyzer::reduce_identifier_from_base(GDScriptParser::IdentifierNod
 			} else if (member.type == GDScriptParser::ClassNode::Member::VARIABLE) {
 				p_identifier->source = GDScriptParser::IdentifierNode::MEMBER_VARIABLE;
 				p_identifier->variable_source = member.variable;
+			} else if (member.type == GDScriptParser::ClassNode::Member::FUNCTION) {
+				p_identifier->set_datatype(make_callable_type(member.function->info));
 			}
 			return;
 		}
@@ -1612,8 +1811,6 @@ void GDScriptAnalyzer::reduce_identifier_from_base(GDScriptParser::IdentifierNod
 			p_identifier->set_datatype(type_from_variant(int_constant));
 			return;
 		}
-	} else {
-		ERR_PRINT(vformat("GDScript parser bug: Class %s isn't a native exposed class.", native.operator String()));
 	}
 }
 
@@ -1624,7 +1821,7 @@ void GDScriptAnalyzer::reduce_identifier(GDScriptParser::IdentifierNode *p_ident
 	switch (p_identifier->source) {
 		case GDScriptParser::IdentifierNode::FUNCTION_PARAMETER:
 			p_identifier->set_datatype(p_identifier->parameter_source->get_datatype());
-			break;
+			return;
 		case GDScriptParser::IdentifierNode::LOCAL_CONSTANT:
 		case GDScriptParser::IdentifierNode::MEMBER_CONSTANT:
 			p_identifier->set_datatype(p_identifier->constant_source->get_datatype());
@@ -1632,8 +1829,10 @@ void GDScriptAnalyzer::reduce_identifier(GDScriptParser::IdentifierNode *p_ident
 			// TODO: Constant should have a value on the node itself.
 			p_identifier->reduced_value = p_identifier->constant_source->initializer->reduced_value;
 			return;
-		case GDScriptParser::IdentifierNode::LOCAL_VARIABLE:
 		case GDScriptParser::IdentifierNode::MEMBER_VARIABLE:
+			p_identifier->variable_source->usages++;
+			[[fallthrough]];
+		case GDScriptParser::IdentifierNode::LOCAL_VARIABLE:
 			p_identifier->set_datatype(p_identifier->variable_source->get_datatype());
 			return;
 		case GDScriptParser::IdentifierNode::LOCAL_ITERATOR:
@@ -1693,7 +1892,12 @@ void GDScriptAnalyzer::reduce_identifier(GDScriptParser::IdentifierNode *p_ident
 	}
 
 	// Not found.
-	push_error(vformat(R"(Identifier "%s" not declared in the current scope.)", name), p_identifier);
+	// Check if it's a builtin function.
+	if (parser->get_builtin_function(name) < GDScriptFunctions::FUNC_MAX) {
+		push_error(vformat(R"(Built-in function "%s" cannot be used as an identifier.)", name), p_identifier);
+	} else {
+		push_error(vformat(R"(Identifier "%s" not declared in the current scope.)", name), p_identifier);
+	}
 	GDScriptParser::DataType dummy;
 	dummy.kind = GDScriptParser::DataType::VARIANT;
 	p_identifier->set_datatype(dummy); // Just so type is set to something.
@@ -1765,7 +1969,11 @@ void GDScriptAnalyzer::reduce_subscript(GDScriptParser::SubscriptNode *p_subscri
 					p_subscript->is_constant = p_subscript->attribute->is_constant;
 					p_subscript->reduced_value = p_subscript->attribute->reduced_value;
 				} else {
-					push_error(vformat(R"(Cannot find member "%s" in base "%s".)", p_subscript->attribute->name, base_type.to_string()), p_subscript->attribute);
+					if (base_type.kind == GDScriptParser::DataType::BUILTIN) {
+						push_error(vformat(R"(Cannot find member "%s" in base "%s".)", p_subscript->attribute->name, base_type.to_string()), p_subscript->attribute);
+					} else {
+						parser->push_warning(p_subscript, GDScriptWarning::UNSAFE_PROPERTY_ACCESS, p_subscript->attribute->name, base_type.to_string());
+					}
 					result_type.kind = GDScriptParser::DataType::VARIANT;
 				}
 			}
@@ -1970,9 +2178,10 @@ void GDScriptAnalyzer::reduce_ternary_op(GDScriptParser::TernaryOpNode *p_ternar
 		if (!is_type_compatible(true_type, false_type)) {
 			result = false_type;
 			if (!is_type_compatible(false_type, true_type)) {
-				// TODO: Add warning here. Types of arms are not compatible with each other.
 				result.type_source = GDScriptParser::DataType::UNDETECTED;
 				result.kind = GDScriptParser::DataType::VARIANT;
+
+				parser->push_warning(p_ternary_op, GDScriptWarning::INCOMPATIBLE_TERNARY);
 			}
 		}
 	}
@@ -2213,7 +2422,7 @@ bool GDScriptAnalyzer::validate_call_arg(const List<GDScriptParser::DataType> &p
 		GDScriptParser::DataType par_type = p_par_types[i];
 		GDScriptParser::DataType arg_type = p_call->arguments[i]->get_datatype();
 
-		if (arg_type.kind == GDScriptParser::DataType::VARIANT) {
+		if (arg_type.is_variant()) {
 			// Argument can be anything, so this is unsafe.
 			mark_node_unsafe(p_call->arguments[i]);
 		} else if (!is_type_compatible(par_type, arg_type, true)) {
@@ -2227,13 +2436,55 @@ bool GDScriptAnalyzer::validate_call_arg(const List<GDScriptParser::DataType> &p
 			}
 		} else {
 			if (par_type.kind == GDScriptParser::DataType::BUILTIN && par_type.builtin_type == Variant::INT && arg_type.kind == GDScriptParser::DataType::BUILTIN && arg_type.builtin_type == Variant::FLOAT) {
-				// TODO: Add narrowing conversion warning.
+				parser->push_warning(p_call, GDScriptWarning::NARROWING_CONVERSION, p_call->function_name);
 			}
 		}
 	}
 	return valid;
 }
 
+bool GDScriptAnalyzer::is_shadowing(GDScriptParser::IdentifierNode *p_local, const String &p_context) {
+	const StringName &name = p_local->name;
+	GDScriptParser::DataType base = parser->current_class->get_datatype();
+
+	GDScriptParser::ClassNode *base_class = base.class_type;
+
+	while (base_class != nullptr) {
+		if (base_class->has_member(name)) {
+			parser->push_warning(p_local, GDScriptWarning::SHADOWED_VARIABLE, p_context, p_local->name, base_class->get_member(name).get_type_name(), itos(base_class->get_member(name).get_line()));
+			return true;
+		}
+		base_class = base_class->base_type.class_type;
+	}
+
+	StringName base_native = base.native_type;
+
+	ERR_FAIL_COND_V_MSG(!class_exists(base_native), false, "Non-existent native base class.");
+
+	StringName parent = base_native;
+	while (parent != StringName()) {
+		if (ClassDB::has_method(parent, name, true)) {
+			parser->push_warning(p_local, GDScriptWarning::SHADOWED_VARIABLE_BASE_CLASS, p_context, p_local->name, "method", parent);
+			return true;
+		} else if (ClassDB::has_signal(parent, name, true)) {
+			parser->push_warning(p_local, GDScriptWarning::SHADOWED_VARIABLE_BASE_CLASS, p_context, p_local->name, "signal", parent);
+			return true;
+		} else if (ClassDB::has_property(parent, name, true)) {
+			parser->push_warning(p_local, GDScriptWarning::SHADOWED_VARIABLE_BASE_CLASS, p_context, p_local->name, "property", parent);
+			return true;
+		} else if (ClassDB::has_integer_constant(parent, name, true)) {
+			parser->push_warning(p_local, GDScriptWarning::SHADOWED_VARIABLE_BASE_CLASS, p_context, p_local->name, "constant", parent);
+			return true;
+		} else if (ClassDB::has_enum(parent, name, true)) {
+			parser->push_warning(p_local, GDScriptWarning::SHADOWED_VARIABLE_BASE_CLASS, p_context, p_local->name, "enum", parent);
+			return true;
+		}
+		parent = ClassDB::get_parent_class(parent);
+	}
+
+	return false;
+}
+
 GDScriptParser::DataType GDScriptAnalyzer::get_operation_type(Variant::Operator p_operation, const GDScriptParser::DataType &p_a, const GDScriptParser::DataType &p_b, bool &r_valid) {
 	// This function creates dummy variant values and apply the operation to those. Less error-prone than keeping a table of valid operations.
 
@@ -2485,6 +2736,13 @@ Error GDScriptAnalyzer::resolve_body() {
 Error GDScriptAnalyzer::resolve_program() {
 	resolve_class_interface(parser->head);
 	resolve_class_body(parser->head);
+
+	List<String> parser_keys;
+	depended_parsers.get_key_list(&parser_keys);
+	for (const List<String>::Element *E = parser_keys.front(); E != nullptr; E = E->next()) {
+		depended_parsers[E->get()]->raise_status(GDScriptParserRef::FULLY_SOLVED);
+	}
+	depended_parsers.clear();
 	return parser->errors.empty() ? OK : ERR_PARSE_ERROR;
 }
 

modules/gdscript/gdscript_analyzer.h

@@ -42,7 +42,7 @@ class GDScriptAnalyzer {
 	HashMap<String, Ref<GDScriptParserRef>> depended_parsers;
 
 	Error resolve_inheritance(GDScriptParser::ClassNode *p_class, bool p_recursive = true);
-	GDScriptParser::DataType resolve_datatype(const GDScriptParser::TypeNode *p_type);
+	GDScriptParser::DataType resolve_datatype(GDScriptParser::TypeNode *p_type);
 
 	void decide_suite_type(GDScriptParser::Node *p_suite, GDScriptParser::Node *p_statement);
 
@@ -74,7 +74,7 @@ class GDScriptAnalyzer {
 	void reduce_assignment(GDScriptParser::AssignmentNode *p_assignment);
 	void reduce_await(GDScriptParser::AwaitNode *p_await);
 	void reduce_binary_op(GDScriptParser::BinaryOpNode *p_binary_op);
-	void reduce_call(GDScriptParser::CallNode *p_call);
+	void reduce_call(GDScriptParser::CallNode *p_call, bool is_await = false);
 	void reduce_cast(GDScriptParser::CastNode *p_cast);
 	void reduce_dictionary(GDScriptParser::DictionaryNode *p_dictionary);
 	void reduce_get_node(GDScriptParser::GetNodeNode *p_get_node);
@@ -96,6 +96,7 @@ class GDScriptAnalyzer {
 	bool function_signature_from_info(const MethodInfo &p_info, GDScriptParser::DataType &r_return_type, List<GDScriptParser::DataType> &r_par_types, int &r_default_arg_count, bool &r_static, bool &r_vararg);
 	bool validate_call_arg(const List<GDScriptParser::DataType> &p_par_types, int p_default_args_count, bool p_is_vararg, const GDScriptParser::CallNode *p_call);
 	bool validate_call_arg(const MethodInfo &p_method, const GDScriptParser::CallNode *p_call);
+	bool is_shadowing(GDScriptParser::IdentifierNode *p_local, const String &p_context);
 	GDScriptParser::DataType get_operation_type(Variant::Operator p_operation, const GDScriptParser::DataType &p_a, const GDScriptParser::DataType &p_b, bool &r_valid);
 	bool is_type_compatible(const GDScriptParser::DataType &p_target, const GDScriptParser::DataType &p_source, bool p_allow_implicit_conversion = false) const;
 	void push_error(const String &p_message, const GDScriptParser::Node *p_origin);

modules/gdscript/gdscript_editor.cpp

@@ -134,23 +134,25 @@ bool GDScriptLanguage::validate(const String &p_script, int &r_line_error, int &
 	GDScriptAnalyzer analyzer(&parser);
 
 	Error err = parser.parse(p_script, p_path, false);
-#ifdef DEBUG_ENABLED
-	// FIXME: Warnings.
-	// if (r_warnings) {
-	// 	for (const List<GDScriptWarning>::Element *E = parser.get_warnings().front(); E; E = E->next()) {
-	// 		const GDScriptWarning &warn = E->get();
-	// 		ScriptLanguage::Warning w;
-	// 		w.line = warn.line;
-	// 		w.code = (int)warn.code;
-	// 		w.string_code = GDScriptWarning::get_name_from_code(warn.code);
-	// 		w.message = warn.get_message();
-	// 		r_warnings->push_back(w);
-	// 	}
-	// }
-#endif
 	if (err == OK) {
 		err = analyzer.analyze();
 	}
+#ifdef DEBUG_ENABLED
+	if (r_warnings) {
+		for (const List<GDScriptWarning>::Element *E = parser.get_warnings().front(); E; E = E->next()) {
+			const GDScriptWarning &warn = E->get();
+			ScriptLanguage::Warning w;
+			w.start_line = warn.start_line;
+			w.end_line = warn.end_line;
+			w.leftmost_column = warn.leftmost_column;
+			w.rightmost_column = warn.rightmost_column;
+			w.code = (int)warn.code;
+			w.string_code = GDScriptWarning::get_name_from_code(warn.code);
+			w.message = warn.get_message();
+			r_warnings->push_back(w);
+		}
+	}
+#endif
 	if (err) {
 		GDScriptParser::ParserError parse_error = parser.get_errors().front()->get();
 		r_line_error = parse_error.line;

modules/gdscript/gdscript_parser.cpp

@@ -33,6 +33,7 @@
 #include "core/io/resource_loader.h"
 #include "core/math/math_defs.h"
 #include "core/os/file_access.h"
+#include "core/project_settings.h"
 #include "gdscript.h"
 
 #ifdef DEBUG_ENABLED
@@ -181,6 +182,61 @@ void GDScriptParser::push_error(const String &p_message, const Node *p_origin) {
 	}
 }
 
+void GDScriptParser::push_warning(const Node *p_source, GDScriptWarning::Code p_code, const String &p_symbol1, const String &p_symbol2, const String &p_symbol3, const String &p_symbol4) {
+	Vector<String> symbols;
+	if (!p_symbol1.empty()) {
+		symbols.push_back(p_symbol1);
+	}
+	if (!p_symbol2.empty()) {
+		symbols.push_back(p_symbol2);
+	}
+	if (!p_symbol3.empty()) {
+		symbols.push_back(p_symbol3);
+	}
+	if (!p_symbol4.empty()) {
+		symbols.push_back(p_symbol4);
+	}
+	push_warning(p_source, p_code, symbols);
+}
+
+void GDScriptParser::push_warning(const Node *p_source, GDScriptWarning::Code p_code, const Vector<String> &p_symbols) {
+	if (is_ignoring_warnings) {
+		return;
+	}
+	if (GLOBAL_GET("debug/gdscript/warnings/exclude_addons").booleanize() && script_path.begins_with("res://addons/")) {
+		return;
+	}
+
+	String warn_name = GDScriptWarning::get_name_from_code((GDScriptWarning::Code)p_code).to_lower();
+	if (ignored_warnings.has(warn_name)) {
+		return;
+	}
+	if (!GLOBAL_GET("debug/gdscript/warnings/" + warn_name)) {
+		return;
+	}
+
+	GDScriptWarning warning;
+	warning.code = p_code;
+	warning.symbols = p_symbols;
+	warning.start_line = p_source->start_line;
+	warning.end_line = p_source->end_line;
+	warning.leftmost_column = p_source->leftmost_column;
+	warning.rightmost_column = p_source->rightmost_column;
+
+	List<GDScriptWarning>::Element *before = nullptr;
+	for (List<GDScriptWarning>::Element *E = warnings.front(); E != nullptr; E = E->next()) {
+		if (E->get().start_line > warning.start_line) {
+			break;
+		}
+		before = E;
+	}
+	if (before) {
+		warnings.insert_after(before, warning);
+	} else {
+		warnings.push_front(warning);
+	}
+}
+
 Error GDScriptParser::parse(const String &p_source_code, const String &p_script_path, bool p_for_completion) {
 	clear();
 	tokenizer.set_source_code(p_source_code);
@@ -601,6 +657,7 @@ GDScriptParser::VariableNode *GDScriptParser::parse_variable(bool p_allow_proper
 	if (match(GDScriptTokenizer::Token::EQUAL)) {
 		// Initializer.
 		variable->initializer = parse_expression(false);
+		variable->assignments++;
 	}
 
 	if (p_allow_property && match(GDScriptTokenizer::Token::COLON)) {
@@ -1106,6 +1163,8 @@ GDScriptParser::SuiteNode *GDScriptParser::parse_suite(const String &p_context,
 
 GDScriptParser::Node *GDScriptParser::parse_statement() {
 	Node *result = nullptr;
+	bool unreachable = current_suite->has_return && !current_suite->has_unreachable_code;
+
 	switch (current.type) {
 		case GDScriptTokenizer::Token::PASS:
 			advance();
@@ -1151,6 +1210,9 @@ GDScriptParser::Node *GDScriptParser::parse_statement() {
 				n_return->return_value = parse_expression(false);
 			}
 			result = n_return;
+
+			current_suite->has_return = true;
+
 			end_statement("return statement");
 			break;
 		}
@@ -1179,10 +1241,27 @@ GDScriptParser::Node *GDScriptParser::parse_statement() {
 			}
 			end_statement("expression");
 			result = expression;
+
+			if (expression != nullptr) {
+				switch (expression->type) {
+					case Node::CALL:
+					case Node::ASSIGNMENT:
+					case Node::AWAIT:
+						// Fine.
+						break;
+					default:
+						push_warning(expression, GDScriptWarning::STANDALONE_EXPRESSION);
+				}
+			}
 			break;
 		}
 	}
 
+	if (unreachable) {
+		current_suite->has_unreachable_code = true;
+		push_warning(result, GDScriptWarning::UNREACHABLE_CODE, current_function->identifier->name);
+	}
+
 	if (panic_mode) {
 		synchronize();
 	}
@@ -1232,6 +1311,7 @@ GDScriptParser::ContinueNode *GDScriptParser::parse_continue() {
 	if (!can_continue) {
 		push_error(R"(Cannot use "continue" outside of a loop or pattern matching block.)");
 	}
+	current_suite->has_continue = true;
 	end_statement(R"("continue")");
 	return alloc_node<ContinueNode>();
 }
@@ -1281,6 +1361,10 @@ GDScriptParser::IfNode *GDScriptParser::parse_if(const String &p_token) {
 
 	n_if->true_block = parse_suite(vformat(R"("%s" block)", p_token));
 
+	if (n_if->true_block->has_continue) {
+		current_suite->has_continue = true;
+	}
+
 	if (match(GDScriptTokenizer::Token::ELIF)) {
 		IfNode *elif = parse_if("elif");
 
@@ -1292,6 +1376,13 @@ GDScriptParser::IfNode *GDScriptParser::parse_if(const String &p_token) {
 		n_if->false_block = parse_suite(R"("else" block)");
 	}
 
+	if (n_if->false_block != nullptr && n_if->false_block->has_return && n_if->true_block->has_return) {
+		current_suite->has_return = true;
+	}
+	if (n_if->false_block != nullptr && n_if->false_block->has_continue) {
+		current_suite->has_continue = true;
+	}
+
 	return n_if;
 }
 
@@ -1310,16 +1401,43 @@ GDScriptParser::MatchNode *GDScriptParser::parse_match() {
 		return match;
 	}
 
+	bool all_have_return = true;
+	bool have_wildcard = false;
+	bool wildcard_has_return = false;
+	bool have_wildcard_without_continue = false;
+	bool have_unreachable_pattern = false;
+
 	while (!check(GDScriptTokenizer::Token::DEDENT) && !is_at_end()) {
 		MatchBranchNode *branch = parse_match_branch();
 		if (branch == nullptr) {
 			continue;
 		}
+
+		if (have_wildcard_without_continue && !have_unreachable_pattern) {
+			push_warning(branch->patterns[0], GDScriptWarning::UNREACHABLE_PATTERN);
+		}
+
+		if (branch->has_wildcard) {
+			have_wildcard = true;
+			if (branch->block->has_return) {
+				wildcard_has_return = true;
+			}
+			if (!branch->block->has_continue) {
+				have_wildcard_without_continue = true;
+			}
+		}
+		if (!branch->block->has_return) {
+			all_have_return = false;
+		}
 		match->branches.push_back(branch);
 	}
 
 	consume(GDScriptTokenizer::Token::DEDENT, R"(Expected an indented block after "match" statement.)");
 
+	if (wildcard_has_return || (all_have_return && have_wildcard)) {
+		current_suite->has_return = true;
+	}
+
 	return match;
 }
 
@@ -1341,6 +1459,8 @@ GDScriptParser::MatchBranchNode *GDScriptParser::parse_match_branch() {
 		}
 		if (pattern->pattern_type == PatternNode::PT_REST) {
 			push_error(R"(Rest pattern can only be used inside array and dictionary patterns.)");
+		} else if (pattern->pattern_type == PatternNode::PT_BIND || pattern->pattern_type == PatternNode::PT_WILDCARD) {
+			branch->has_wildcard = true;
 		}
 		branch->patterns.push_back(pattern);
 	} while (match(GDScriptTokenizer::Token::COMMA));
@@ -1605,22 +1725,27 @@ GDScriptParser::ExpressionNode *GDScriptParser::parse_identifier(ExpressionNode
 			case SuiteNode::Local::CONSTANT:
 				identifier->source = IdentifierNode::LOCAL_CONSTANT;
 				identifier->constant_source = declaration.constant;
+				declaration.constant->usages++;
 				break;
 			case SuiteNode::Local::VARIABLE:
 				identifier->source = IdentifierNode::LOCAL_VARIABLE;
 				identifier->variable_source = declaration.variable;
+				declaration.variable->usages++;
 				break;
 			case SuiteNode::Local::PARAMETER:
 				identifier->source = IdentifierNode::FUNCTION_PARAMETER;
 				identifier->parameter_source = declaration.parameter;
+				declaration.parameter->usages++;
 				break;
 			case SuiteNode::Local::FOR_VARIABLE:
 				identifier->source = IdentifierNode::LOCAL_ITERATOR;
 				identifier->bind_source = declaration.bind;
+				declaration.bind->usages++;
 				break;
 			case SuiteNode::Local::PATTERN_BIND:
 				identifier->source = IdentifierNode::LOCAL_BIND;
 				identifier->bind_source = declaration.bind;
+				declaration.bind->usages++;
 				break;
 			case SuiteNode::Local::UNDEFINED:
 				ERR_FAIL_V_MSG(nullptr, "Undefined local found.");
@@ -1836,8 +1961,33 @@ GDScriptParser::ExpressionNode *GDScriptParser::parse_assignment(ExpressionNode
 		return parse_expression(false); // Return the following expression.
 	}
 
+	VariableNode *source_variable = nullptr;
+
 	switch (p_previous_operand->type) {
-		case Node::IDENTIFIER:
+		case Node::IDENTIFIER: {
+			// Get source to store assignment count.
+			// Also remove one usage since assignment isn't usage.
+			IdentifierNode *id = static_cast<IdentifierNode *>(p_previous_operand);
+			switch (id->source) {
+				case IdentifierNode::LOCAL_VARIABLE:
+					source_variable = id->variable_source;
+					id->variable_source->usages--;
+					break;
+				case IdentifierNode::LOCAL_CONSTANT:
+					id->constant_source->usages--;
+					break;
+				case IdentifierNode::FUNCTION_PARAMETER:
+					id->parameter_source->usages--;
+					break;
+				case IdentifierNode::LOCAL_ITERATOR:
+				case IdentifierNode::LOCAL_BIND:
+					id->bind_source->usages--;
+					break;
+				default:
+					break;
+			}
+			break;
+		}
 		case Node::SUBSCRIPT:
 			// Okay.
 			break;
@@ -1847,9 +1997,11 @@ GDScriptParser::ExpressionNode *GDScriptParser::parse_assignment(ExpressionNode
 	}
 
 	AssignmentNode *assignment = alloc_node<AssignmentNode>();
+	bool has_operator = true;
 	switch (previous.type) {
 		case GDScriptTokenizer::Token::EQUAL:
 			assignment->operation = AssignmentNode::OP_NONE;
+			has_operator = false;
 			break;
 		case GDScriptTokenizer::Token::PLUS_EQUAL:
 			assignment->operation = AssignmentNode::OP_ADDITION;
@@ -1887,6 +2039,10 @@ GDScriptParser::ExpressionNode *GDScriptParser::parse_assignment(ExpressionNode
 	assignment->assignee = p_previous_operand;
 	assignment->assigned_value = parse_expression(false);
 
+	if (has_operator && source_variable != nullptr && source_variable->assignments == 0) {
+		push_warning(assignment, GDScriptWarning::UNASSIGNED_VARIABLE_OP_ASSIGN, source_variable->identifier->name);
+	}
+
 	return assignment;
 }
 

modules/gdscript/gdscript_parser.h

@@ -44,6 +44,7 @@
 #include "core/vector.h"
 #include "gdscript_functions.h"
 #include "gdscript_tokenizer.h"
+#include "gdscript_warning.h"
 
 #ifdef DEBUG_ENABLED
 #include "core/string_builder.h"
@@ -101,7 +102,7 @@ public:
 			CLASS, // GDScript.
 			VARIANT, // Can be any type.
 			UNRESOLVED,
-			// TODO: Enum, Signal, Callable
+			// TODO: Enum
 		};
 		Kind kind = UNRESOLVED;
 
@@ -366,7 +367,7 @@ public:
 	struct CallNode : public ExpressionNode {
 		ExpressionNode *callee = nullptr;
 		Vector<ExpressionNode *> arguments;
-		StringName function_name; // TODO: Set this.
+		StringName function_name;
 		bool is_super = false;
 
 		CallNode() {
@@ -388,6 +389,9 @@ public:
 			IdentifierNode *identifier = nullptr;
 			LiteralNode *custom_value = nullptr;
 			int value = 0;
+			int line = 0;
+			int leftmost_column = 0;
+			int rightmost_column = 0;
 		};
 		IdentifierNode *identifier = nullptr;
 		Vector<Value> values;
@@ -444,6 +448,28 @@ public:
 				return "";
 			}
 
+			int get_line() const {
+				switch (type) {
+					case CLASS:
+						return m_class->start_line;
+					case CONSTANT:
+						return constant->start_line;
+					case FUNCTION:
+						return function->start_line;
+					case VARIABLE:
+						return variable->start_line;
+					case ENUM_VALUE:
+						return enum_value.line;
+					case ENUM:
+						return m_enum->start_line;
+					case SIGNAL:
+						return signal->start_line;
+					case UNDEFINED:
+						ERR_FAIL_V_MSG(-1, "Reaching undefined member type.");
+				}
+				ERR_FAIL_V_MSG(-1, "Reaching unhandled type.");
+			}
+
 			DataType get_datatype() const {
 				switch (type) {
 					case CLASS:
@@ -462,9 +488,16 @@ public:
 						type.builtin_type = Variant::INT;
 						return type;
 					}
+					case SIGNAL: {
+						DataType type;
+						type.type_source = DataType::ANNOTATED_EXPLICIT;
+						type.kind = DataType::BUILTIN;
+						type.builtin_type = Variant::SIGNAL;
+						// TODO: Add parameter info.
+						return type;
+					}
 					case ENUM:
-					case SIGNAL:
+						// TODO: Use special datatype kinds for this.
-						// TODO: Use special datatype kinds for these.
 						return DataType();
 					case UNDEFINED:
 						return DataType();
@@ -545,6 +578,7 @@ public:
 		ExpressionNode *initializer = nullptr;
 		TypeNode *datatype_specifier = nullptr;
 		bool infer_datatype = false;
+		int usages = 0;
 
 		ConstantNode() {
 			type = CONSTANT;
@@ -594,6 +628,7 @@ public:
 		bool is_static = false;
 		bool is_coroutine = false;
 		MultiplayerAPI::RPCMode rpc_mode = MultiplayerAPI::RPC_MODE_DISABLED;
+		MethodInfo info;
 
 		bool resolved_signature = false;
 		bool resolved_body = false;
@@ -634,6 +669,8 @@ public:
 			IdentifierNode *bind_source;
 		};
 
+		int usages = 0; // Useful for binds/iterator variable.
+
 		IdentifierNode() {
 			type = IDENTIFIER;
 		}
@@ -669,6 +706,7 @@ public:
 	struct MatchBranchNode : public Node {
 		Vector<PatternNode *> patterns;
 		SuiteNode *block;
+		bool has_wildcard = false;
 
 		MatchBranchNode() {
 			type = MATCH_BRANCH;
@@ -680,6 +718,7 @@ public:
 		ExpressionNode *default_value = nullptr;
 		TypeNode *datatype_specifier = nullptr;
 		bool infer_datatype = false;
+		int usages = 0;
 
 		ParameterNode() {
 			type = PARAMETER;
@@ -836,6 +875,10 @@ public:
 		IfNode *parent_if = nullptr;
 		PatternNode *parent_pattern = nullptr;
 
+		bool has_return = false;
+		bool has_continue = false;
+		bool has_unreachable_code = false; // Just so warnings aren't given more than once per block.
+
 		bool has_local(const StringName &p_name) const;
 		const Local &get_local(const StringName &p_name) const;
 		template <class T>
@@ -916,6 +959,8 @@ public:
 		bool onready = false;
 		PropertyInfo export_info;
 		MultiplayerAPI::RPCMode rpc_mode = MultiplayerAPI::RPC_MODE_DISABLED;
+		int assignments = 0;
+		int usages = 0;
 
 		VariableNode() {
 			type = VARIABLE;
@@ -940,11 +985,15 @@ private:
 	bool panic_mode = false;
 	bool can_break = false;
 	bool can_continue = false;
+	bool is_ignoring_warnings = false;
 	List<bool> multiline_stack;
 
 	ClassNode *head = nullptr;
 	Node *list = nullptr;
 	List<ParserError> errors;
+	List<GDScriptWarning> warnings;
+	Set<String> ignored_warnings;
+	Set<int> unsafe_lines;
 
 	GDScriptTokenizer tokenizer;
 	GDScriptTokenizer::Token previous;
@@ -974,8 +1023,6 @@ private:
 	HashMap<StringName, AnnotationInfo> valid_annotations;
 	List<AnnotationNode *> annotation_stack;
 
-	Set<int> unsafe_lines;
-
 	typedef ExpressionNode *(GDScriptParser::*ParseFunction)(ExpressionNode *p_previous_operand, bool p_can_assign);
 	// Higher value means higher precedence (i.e. is evaluated first).
 	enum Precedence {
@@ -1015,6 +1062,8 @@ private:
 	T *alloc_node();
 	void clear();
 	void push_error(const String &p_message, const Node *p_origin = nullptr);
+	void push_warning(const Node *p_source, GDScriptWarning::Code p_code, const String &p_symbol1 = String(), const String &p_symbol2 = String(), const String &p_symbol3 = String(), const String &p_symbol4 = String());
+	void push_warning(const Node *p_source, GDScriptWarning::Code p_code, const Vector<String> &p_symbols);
 
 	GDScriptTokenizer::Token advance();
 	bool match(GDScriptTokenizer::Token::Type p_token_type);
@@ -1104,6 +1153,7 @@ public:
 	static GDScriptFunctions::Function get_builtin_function(const StringName &p_name);
 
 	const List<ParserError> &get_errors() const { return errors; }
+	const List<GDScriptWarning> &get_warnings() const { return warnings; }
 	const List<String> get_dependencies() const {
 		// TODO: Keep track of deps.
 		return List<String>();

modules/gdscript/gdscript_warning.cpp

@@ -30,6 +30,8 @@
 
 #include "gdscript_warning.h"
 
+#include "core/variant.h"
+
 #ifdef DEBUG_ENABLED
 
 String GDScriptWarning::get_message() const {
@@ -48,22 +50,33 @@ String GDScriptWarning::get_message() const {
 			CHECK_SYMBOLS(1);
 			return "The local variable '" + symbols[0] + "' is declared but never used in the block. If this is intended, prefix it with an underscore: '_" + symbols[0] + "'";
 		} break;
-		case SHADOWED_VARIABLE: {
+		case UNUSED_LOCAL_CONSTANT: {
-			CHECK_SYMBOLS(2);
+			CHECK_SYMBOLS(1);
-			return "The local variable '" + symbols[0] + "' is shadowing an already-defined variable at line " + symbols[1] + ".";
+			return "The local constant '" + symbols[0] + "' is declared but never used in the block. If this is intended, prefix it with an underscore: '_" + symbols[0] + "'";
 		} break;
-		case UNUSED_CLASS_VARIABLE: {
+		case SHADOWED_VARIABLE: {
+			CHECK_SYMBOLS(4);
+			return vformat(R"(The local %s "%s" is shadowing an already-declared %s at line %s.)", symbols[0], symbols[1], symbols[2], symbols[3]);
+		} break;
+		case SHADOWED_VARIABLE_BASE_CLASS: {
+			CHECK_SYMBOLS(4);
+			return vformat(R"(The local %s "%s" is shadowing an already-declared %s at the base class "%s".)", symbols[0], symbols[1], symbols[2], symbols[3]);
+		} break;
+		case UNUSED_PRIVATE_CLASS_VARIABLE: {
 			CHECK_SYMBOLS(1);
 			return "The class variable '" + symbols[0] + "' is declared but never used in the script.";
 		} break;
-		case UNUSED_ARGUMENT: {
+		case UNUSED_PARAMETER: {
 			CHECK_SYMBOLS(2);
-			return "The argument '" + symbols[1] + "' is never used in the function '" + symbols[0] + "'. If this is intended, prefix it with an underscore: '_" + symbols[1] + "'";
+			return "The parameter '" + symbols[1] + "' is never used in the function '" + symbols[0] + "'. If this is intended, prefix it with an underscore: '_" + symbols[1] + "'";
 		} break;
 		case UNREACHABLE_CODE: {
 			CHECK_SYMBOLS(1);
 			return "Unreachable code (statement after return) in function '" + symbols[0] + "()'.";
 		} break;
+		case UNREACHABLE_PATTERN: {
+			return "Unreachable pattern (pattern after wildcard or bind).";
+		} break;
 		case STANDALONE_EXPRESSION: {
 			return "Standalone expression (the line has no effect).";
 		} break;
@@ -74,22 +87,6 @@ String GDScriptWarning::get_message() const {
 		case NARROWING_CONVERSION: {
 			return "Narrowing conversion (float is converted to int and loses precision).";
 		} break;
-		case FUNCTION_MAY_YIELD: {
-			CHECK_SYMBOLS(1);
-			return "Assigned variable is typed but the function '" + symbols[0] + "()' may yield and return a GDScriptFunctionState instead.";
-		} break;
-		case VARIABLE_CONFLICTS_FUNCTION: {
-			CHECK_SYMBOLS(1);
-			return "Variable declaration of '" + symbols[0] + "' conflicts with a function of the same name.";
-		} break;
-		case FUNCTION_CONFLICTS_VARIABLE: {
-			CHECK_SYMBOLS(1);
-			return "Function declaration of '" + symbols[0] + "()' conflicts with a variable of the same name.";
-		} break;
-		case FUNCTION_CONFLICTS_CONSTANT: {
-			CHECK_SYMBOLS(1);
-			return "Function declaration of '" + symbols[0] + "()' conflicts with a constant of the same name.";
-		} break;
 		case INCOMPATIBLE_TERNARY: {
 			return "Values of the ternary conditional are not mutually compatible.";
 		} break;
@@ -139,6 +136,15 @@ String GDScriptWarning::get_message() const {
 		case STANDALONE_TERNARY: {
 			return "Standalone ternary conditional operator: the return value is being discarded.";
 		}
+		case ASSERT_ALWAYS_TRUE: {
+			return "Assert statement is redundant because the expression is always true.";
+		}
+		case ASSERT_ALWAYS_FALSE: {
+			return "Assert statement will raise an error because the expression is always false.";
+		}
+		case REDUNDANT_AWAIT: {
+			return R"("await" keyword not needed in this case, because the expression isn't a coroutine nor a signal.)";
+		}
 		case WARNING_MAX:
 			break; // Can't happen, but silences warning
 	}
@@ -158,17 +164,16 @@ String GDScriptWarning::get_name_from_code(Code p_code) {
 		"UNASSIGNED_VARIABLE",
 		"UNASSIGNED_VARIABLE_OP_ASSIGN",
 		"UNUSED_VARIABLE",
+		"UNUSED_LOCAL_CONSTANT",
 		"SHADOWED_VARIABLE",
-		"UNUSED_CLASS_VARIABLE",
+		"SHADOWED_VARIABLE_BASE_CLASS",
-		"UNUSED_ARGUMENT",
+		"UNUSED_PRIVATE_CLASS_VARIABLE",
+		"UNUSED_PARAMETER",
 		"UNREACHABLE_CODE",
+		"UNREACHABLE_PATTERN",
 		"STANDALONE_EXPRESSION",
 		"VOID_ASSIGNMENT",
 		"NARROWING_CONVERSION",
-		"FUNCTION_MAY_YIELD",
-		"VARIABLE_CONFLICTS_FUNCTION",
-		"FUNCTION_CONFLICTS_VARIABLE",
-		"FUNCTION_CONFLICTS_CONSTANT",
 		"INCOMPATIBLE_TERNARY",
 		"UNUSED_SIGNAL",
 		"RETURN_VALUE_DISCARDED",
@@ -182,9 +187,13 @@ String GDScriptWarning::get_name_from_code(Code p_code) {
 		"UNSAFE_CALL_ARGUMENT",
 		"DEPRECATED_KEYWORD",
 		"STANDALONE_TERNARY",
-		nullptr
+		"ASSERT_ALWAYS_TRUE",
+		"ASSERT_ALWAYS_FALSE",
+		"REDUNDANT_AWAIT",
 	};
 
+	static_assert((sizeof(names) / sizeof(*names)) == WARNING_MAX, "Amount of warning types don't match the amount of warning names.");
+
 	return names[(int)p_code];
 }
 

modules/gdscript/gdscript_warning.h

@@ -39,38 +39,41 @@
 class GDScriptWarning {
 public:
 	enum Code {
-		UNASSIGNED_VARIABLE, // Variable used but never assigned
+		UNASSIGNED_VARIABLE, // Variable used but never assigned.
-		UNASSIGNED_VARIABLE_OP_ASSIGN, // Variable never assigned but used in an assignment operation (+=, *=, etc)
+		UNASSIGNED_VARIABLE_OP_ASSIGN, // Variable never assigned but used in an assignment operation (+=, *=, etc).
-		UNUSED_VARIABLE, // Local variable is declared but never used
+		UNUSED_VARIABLE, // Local variable is declared but never used.
-		SHADOWED_VARIABLE, // Variable name shadowed by other variable
+		UNUSED_LOCAL_CONSTANT, // Local constant is declared but never used.
-		UNUSED_CLASS_VARIABLE, // Class variable is declared but never used in the file
+		SHADOWED_VARIABLE, // Variable name shadowed by other variable in same class.
-		UNUSED_ARGUMENT, // Function argument is never used
+		SHADOWED_VARIABLE_BASE_CLASS, // Variable name shadowed by other variable in some base class.
-		UNREACHABLE_CODE, // Code after a return statement
+		UNUSED_PRIVATE_CLASS_VARIABLE, // Class variable is declared private ("_" prefix) but never used in the file.
-		STANDALONE_EXPRESSION, // Expression not assigned to a variable
+		UNUSED_PARAMETER, // Function parameter is never used.
-		VOID_ASSIGNMENT, // Function returns void but it's assigned to a variable
+		UNREACHABLE_CODE, // Code after a return statement.
-		NARROWING_CONVERSION, // Float value into an integer slot, precision is lost
+		UNREACHABLE_PATTERN, // Pattern in a match statement after a catch all pattern (wildcard or bind).
-		FUNCTION_MAY_YIELD, // Typed assign of function call that yields (it may return a function state)
+		STANDALONE_EXPRESSION, // Expression not assigned to a variable.
-		VARIABLE_CONFLICTS_FUNCTION, // Variable has the same name of a function
+		VOID_ASSIGNMENT, // Function returns void but it's assigned to a variable.
-		FUNCTION_CONFLICTS_VARIABLE, // Function has the same name of a variable
+		NARROWING_CONVERSION, // Float value into an integer slot, precision is lost.
-		FUNCTION_CONFLICTS_CONSTANT, // Function has the same name of a constant
+		INCOMPATIBLE_TERNARY, // Possible values of a ternary if are not mutually compatible.
-		INCOMPATIBLE_TERNARY, // Possible values of a ternary if are not mutually compatible
+		UNUSED_SIGNAL, // Signal is defined but never emitted.
-		UNUSED_SIGNAL, // Signal is defined but never emitted
+		RETURN_VALUE_DISCARDED, // Function call returns something but the value isn't used.
-		RETURN_VALUE_DISCARDED, // Function call returns something but the value isn't used
+		PROPERTY_USED_AS_FUNCTION, // Function not found, but there's a property with the same name.
-		PROPERTY_USED_AS_FUNCTION, // Function not found, but there's a property with the same name
+		CONSTANT_USED_AS_FUNCTION, // Function not found, but there's a constant with the same name.
-		CONSTANT_USED_AS_FUNCTION, // Function not found, but there's a constant with the same name
+		FUNCTION_USED_AS_PROPERTY, // Property not found, but there's a function with the same name.
-		FUNCTION_USED_AS_PROPERTY, // Property not found, but there's a function with the same name
+		INTEGER_DIVISION, // Integer divide by integer, decimal part is discarded.
-		INTEGER_DIVISION, // Integer divide by integer, decimal part is discarded
+		UNSAFE_PROPERTY_ACCESS, // Property not found in the detected type (but can be in subtypes).
-		UNSAFE_PROPERTY_ACCESS, // Property not found in the detected type (but can be in subtypes)
+		UNSAFE_METHOD_ACCESS, // Function not found in the detected type (but can be in subtypes).
-		UNSAFE_METHOD_ACCESS, // Function not found in the detected type (but can be in subtypes)
+		UNSAFE_CAST, // Cast used in an unknown type.
-		UNSAFE_CAST, // Cast used in an unknown type
+		UNSAFE_CALL_ARGUMENT, // Function call argument is of a supertype of the require argument.
-		UNSAFE_CALL_ARGUMENT, // Function call argument is of a supertype of the require argument
+		DEPRECATED_KEYWORD, // The keyword is deprecated and should be replaced.
-		DEPRECATED_KEYWORD, // The keyword is deprecated and should be replaced
+		STANDALONE_TERNARY, // Return value of ternary expression is discarded.
-		STANDALONE_TERNARY, // Return value of ternary expression is discarded
+		ASSERT_ALWAYS_TRUE, // Expression for assert argument is always true.
+		ASSERT_ALWAYS_FALSE, // Expression for assert argument is always false.
+		REDUNDANT_AWAIT, // await is used but expression is synchronous (not a signal nor a coroutine).
 		WARNING_MAX,
 	};
 
 	Code code = WARNING_MAX;
-	int line = -1;
+	int start_line = -1, end_line = -1;
+	int leftmost_column = -1, rightmost_column = -1;
 	Vector<String> symbols;
 
 	String get_name() const;