Handle intersection in can_elide_return_type_check()

Author: nikic

Zend/Optimizer/dfa_pass.c

@@ -312,17 +312,21 @@ static inline bool can_elide_return_type_check(
 
 	if (disallowed_types == MAY_BE_OBJECT && use_info->ce && ZEND_TYPE_IS_COMPLEX(arg_info->type)) {
 		zend_type *single_type;
+		/* For intersection: result==false is failure, default is success.
+		 * For union: result==true is success, default is failure. */
+		bool is_intersection = ZEND_TYPE_IS_INTERSECTION(arg_info->type);
 		ZEND_TYPE_FOREACH(arg_info->type, single_type) {
 			if (ZEND_TYPE_HAS_NAME(*single_type)) {
 				zend_string *lcname = zend_string_tolower(ZEND_TYPE_NAME(*single_type));
 				zend_class_entry *ce = zend_optimizer_get_class_entry(script, lcname);
 				zend_string_release(lcname);
-				if (ce && ZEND_TYPE_IS_UNION(arg_info->type) && safe_instanceof(use_info->ce, ce)) {
-					/* One of the class union types matched. */
-					return true;
+				bool result = ce && safe_instanceof(use_info->ce, ce);
+				if (result == !is_intersection) {
+					return result;
 				}
 			}
 		} ZEND_TYPE_FOREACH_END();
+		return is_intersection;
 	}
 
 	return false;

ext/opcache/tests/opt/verify_return_type.phpt

@@ -51,6 +51,10 @@ function getClassUnion(): stdClass|FooBar {
     return new stdClass;
 }
 
+function getClassIntersection(): Traversable&Countable {
+    return new ArrayObject;
+}
+
 ?>
 --EXPECTF--
 $_main:
@@ -69,6 +73,16 @@ getClassUnion:
 LIVE RANGES:
      0: 0001 - 0002 (new)
 
+getClassIntersection:
+     ; (lines=3, args=0, vars=0, tmps=1)
+     ; (after optimizer)
+     ; %s
+0000 V0 = NEW 0 string("ArrayObject")
+0001 DO_FCALL
+0002 RETURN V0
+LIVE RANGES:
+     0: 0001 - 0002 (new)
+
 Test1::getIntOrFloat:
      ; (lines=2, args=1, vars=1, tmps=0)
      ; (after optimizer)