Use FETCH_CLASS_EXCEPTION for instanceof

This does not collide with NO_AUTOLOAD -- missing classes will be
silenced, but invalid use of self etc will result in an exception
instead of a fatal error.

Author: nikic

Zend/tests/self_instanceof_outside_class.phpt

@@ -0,0 +1,17 @@
+--TEST--
+instanceof self outside a class
+--FILE--
+<?php
+
+$fn = function() {
+    try {
+        new stdClass instanceof self;
+    } catch (Error $e) {
+        echo $e->getMessage(), "\n";
+    }
+};
+$fn();
+
+?>
+--EXPECT--
+Cannot access self:: when no class scope is active

Zend/zend_compile.c

@@ -6545,7 +6545,8 @@ void zend_compile_instanceof(znode *result, zend_ast *ast) /* {{{ */
 			"instanceof expects an object instance, constant given");
 	}
 
-	zend_compile_class_ref_ex(&class_node, class_ast, ZEND_FETCH_CLASS_NO_AUTOLOAD);
+	zend_compile_class_ref_ex(&class_node, class_ast,
+		ZEND_FETCH_CLASS_NO_AUTOLOAD | ZEND_FETCH_CLASS_EXCEPTION);
 
 	opline = zend_emit_op_tmp(result, ZEND_INSTANCEOF, &obj_node, NULL);
 

Zend/zend_vm_def.h

@@ -7173,6 +7173,7 @@ ZEND_VM_C_LABEL(try_instanceof):
 			ce = zend_fetch_class(NULL, opline->op2.num);
 			if (UNEXPECTED(ce == NULL)) {
 				ZEND_ASSERT(EG(exception));
+				FREE_OP1();
 				HANDLE_EXCEPTION();
 			}
 		} else {

Zend/zend_vm_execute.h

@@ -33206,6 +33206,7 @@ static ZEND_OPCODE_HANDLER_RET ZEND_FASTCALL ZEND_INSTANCEOF_SPEC_CV_CONST_HANDL
 			ce = zend_fetch_class(NULL, opline->op2.num);
 			if (UNEXPECTED(ce == NULL)) {
 				ZEND_ASSERT(EG(exception));
+
 				HANDLE_EXCEPTION();
 			}
 		} else {
@@ -34096,6 +34097,7 @@ static ZEND_OPCODE_HANDLER_RET ZEND_FASTCALL ZEND_INSTANCEOF_SPEC_CV_VAR_HANDLER
 			ce = zend_fetch_class(NULL, opline->op2.num);
 			if (UNEXPECTED(ce == NULL)) {
 				ZEND_ASSERT(EG(exception));
+
 				HANDLE_EXCEPTION();
 			}
 		} else {
@@ -35496,6 +35498,7 @@ static ZEND_OPCODE_HANDLER_RET ZEND_FASTCALL ZEND_INSTANCEOF_SPEC_CV_UNUSED_HAND
 			ce = zend_fetch_class(NULL, opline->op2.num);
 			if (UNEXPECTED(ce == NULL)) {
 				ZEND_ASSERT(EG(exception));
+
 				HANDLE_EXCEPTION();
 			}
 		} else {
@@ -42855,6 +42858,7 @@ static ZEND_OPCODE_HANDLER_RET ZEND_FASTCALL ZEND_INSTANCEOF_SPEC_TMPVAR_CONST_H
 			ce = zend_fetch_class(NULL, opline->op2.num);
 			if (UNEXPECTED(ce == NULL)) {
 				ZEND_ASSERT(EG(exception));
+				zval_ptr_dtor_nogc(free_op1);
 				HANDLE_EXCEPTION();
 			}
 		} else {
@@ -43188,6 +43192,7 @@ static ZEND_OPCODE_HANDLER_RET ZEND_FASTCALL ZEND_INSTANCEOF_SPEC_TMPVAR_VAR_HAN
 			ce = zend_fetch_class(NULL, opline->op2.num);
 			if (UNEXPECTED(ce == NULL)) {
 				ZEND_ASSERT(EG(exception));
+				zval_ptr_dtor_nogc(free_op1);
 				HANDLE_EXCEPTION();
 			}
 		} else {
@@ -43764,6 +43769,7 @@ static ZEND_OPCODE_HANDLER_RET ZEND_FASTCALL ZEND_INSTANCEOF_SPEC_TMPVAR_UNUSED_
 			ce = zend_fetch_class(NULL, opline->op2.num);
 			if (UNEXPECTED(ce == NULL)) {
 				ZEND_ASSERT(EG(exception));
+				zval_ptr_dtor_nogc(free_op1);
 				HANDLE_EXCEPTION();
 			}
 		} else {