Support class variance for internal classes

Author: nikic

Zend/zend_inheritance.c

@@ -240,12 +240,18 @@ static zend_bool class_visible(zend_class_entry *ce) {
 }
 
 static zend_class_entry *lookup_class(zend_string *name) {
-	zend_class_entry *ce = zend_lookup_class(name);
-	if (!ce) {
-		return NULL;
+	zend_class_entry *ce;
+	if (EG(active)) {
+		ce = zend_lookup_class(name);
+	} else {
+		/* When a class lookup is necessary during internal class registration in early
+		 * startup, look it up in CG(class_table), as the executor is not active yet. */
+		zend_string *lcname = zend_string_tolower(name);
+		ce = zend_hash_find_ptr(CG(class_table), lcname);
+		zend_string_release(lcname);
 	}
 
-	return class_visible(ce) ? ce : NULL;
+	return ce && class_visible(ce) ? ce : NULL;
 }
 
 static zend_class_entry *resolve_and_lookup_class(const zend_function *fe, zend_string *name) {
@@ -284,8 +290,8 @@ static inheritance_status _check_covariance(
 	}
 
 	if (ZEND_TYPE_IS_CLASS(proto_type)) {
-		zend_string *proto_class_name;
-		zend_string *fe_class_name;
+		zend_string *proto_class_name, *fe_class_name;
+		zend_class_entry *proto_ce, *fe_ce;
 		if (!ZEND_TYPE_IS_CLASS(fe_type)) {
 			return INHERITANCE_ERROR;
 		}
@@ -300,20 +306,15 @@ static inheritance_status _check_covariance(
 			return INHERITANCE_SUCCESS;
 		}
 
-		if (fe->common.type == ZEND_USER_FUNCTION) {
-			zend_class_entry *fe_ce = lookup_class(fe_class_name);
-			zend_class_entry *proto_ce = lookup_class(proto_class_name);
-			if (!fe_ce || !proto_ce) {
-				return INHERITANCE_UNRESOLVED;
-			}
-
-			return instanceof_function(fe_ce, proto_ce)
-				? INHERITANCE_SUCCESS
-				: INHERITANCE_ERROR;
-		} else {
-			/* TODO: what should this actually do? */
-			return INHERITANCE_ERROR;
+		fe_ce = lookup_class(fe_class_name);
+		proto_ce = lookup_class(proto_class_name);
+		if (!fe_ce || !proto_ce) {
+			return INHERITANCE_UNRESOLVED;
 		}
+
+		return instanceof_function(fe_ce, proto_ce)
+			? INHERITANCE_SUCCESS
+			: INHERITANCE_ERROR;
 	}
 
 	switch (proto_type_code) {

ext/zend_test/test.c

@@ -179,11 +179,37 @@ static int zend_test_class_call_method(zend_string *method, zend_object *object,
 }
 /* }}} */
 
+static ZEND_METHOD(_ZendTestClass, varianceTest) /* {{{ */ {
+	RETURN_TRUE;
+}
+/* }}} */
+
+static ZEND_METHOD(_ZendTestChildClass, varianceTest) /* {{{ */ {
+	RETURN_TRUE;
+}
+/* }}} */
+
 static ZEND_METHOD(_ZendTestTrait, testMethod) /* {{{ */ {
 	RETURN_TRUE;
 }
 /* }}} */
 
+ZEND_BEGIN_ARG_WITH_RETURN_OBJ_INFO_EX(arginfo_parent, 0, 0, _ZendTestClass, 0)
+ZEND_END_ARG_INFO()
+
+ZEND_BEGIN_ARG_WITH_RETURN_OBJ_INFO_EX(arginfo_child, 0, 0, _ZendTestChildClass, 0)
+ZEND_END_ARG_INFO()
+
+static const zend_function_entry zend_test_class_methods[] = {
+    ZEND_ME(_ZendTestClass, varianceTest, arginfo_parent, ZEND_ACC_PUBLIC)
+    ZEND_FE_END
+};
+
+static const zend_function_entry zend_test_child_class_methods[] = {
+    ZEND_ME(_ZendTestChildClass, varianceTest, arginfo_child, ZEND_ACC_PUBLIC)
+    ZEND_FE_END
+};
+
 static const zend_function_entry zend_test_trait_methods[] = {
     ZEND_ME(_ZendTestTrait, testMethod, NULL, ZEND_ACC_PUBLIC)
     ZEND_FE_END
@@ -196,7 +222,7 @@ PHP_MINIT_FUNCTION(zend_test)
 	INIT_CLASS_ENTRY(class_entry, "_ZendTestInterface", NULL);
 	zend_test_interface = zend_register_internal_interface(&class_entry);
 	zend_declare_class_constant_long(zend_test_interface, ZEND_STRL("DUMMY"), 0);
-	INIT_CLASS_ENTRY(class_entry, "_ZendTestClass", NULL);
+	INIT_CLASS_ENTRY(class_entry, "_ZendTestClass", zend_test_class_methods);
 	zend_test_class = zend_register_internal_class_ex(&class_entry, NULL);
 	zend_class_implements(zend_test_class, 1, zend_test_interface);
 	zend_test_class->create_object = zend_test_class_new;
@@ -234,7 +260,7 @@ PHP_MINIT_FUNCTION(zend_test)
 		zend_string_release(name);
 	}
 
-	INIT_CLASS_ENTRY(class_entry, "_ZendTestChildClass", NULL);
+	INIT_CLASS_ENTRY(class_entry, "_ZendTestChildClass", zend_test_child_class_methods);
 	zend_test_child_class = zend_register_internal_class_ex(&class_entry, zend_test_class);
 
 	memcpy(&zend_test_class_handlers, &std_object_handlers, sizeof(zend_object_handlers));