Reuse wrong string offset logic in jit

JIT contains a copy of this function that effectively only differs
by fetching current_execute_data from EG. We can do that in the VM
version as well, as this is just used to throw an error.

Export the VM function and reuse it in JIT.

Author: nikic

Zend/zend_execute.c

@@ -1539,10 +1539,10 @@ static zend_never_inline zend_long zend_check_string_offset(zval *dim, int type
 	return offset;
 }
 
-static zend_never_inline ZEND_COLD void zend_wrong_string_offset(EXECUTE_DATA_D)
+ZEND_API ZEND_COLD void zend_wrong_string_offset_error(void)
 {
 	const char *msg = NULL;
-	const zend_op *opline = EX(opline);
+	const zend_op *opline = EG(current_execute_data)->opline;
 	uint32_t var;
 
 	if (UNEXPECTED(EG(exception) != NULL)) {
@@ -2183,7 +2183,7 @@ static ZEND_COLD void zend_binary_assign_op_dim_slow(zval *container, zval *dim
 			zend_use_new_element_for_string();
 		} else {
 			zend_check_string_offset(dim, BP_VAR_RW EXECUTE_DATA_CC);
-			zend_wrong_string_offset(EXECUTE_DATA_C);
+			zend_wrong_string_offset_error();
 		}
 	} else {
 		zend_use_scalar_as_array();
@@ -2379,7 +2379,7 @@ static zend_always_inline void zend_fetch_dimension_address(zval *result, zval *
 			zend_use_new_element_for_string();
 		} else {
 			zend_check_string_offset(dim, type EXECUTE_DATA_CC);
-			zend_wrong_string_offset(EXECUTE_DATA_C);
+			zend_wrong_string_offset_error();
 		}
 		ZVAL_UNDEF(result);
 	} else if (EXPECTED(Z_TYPE_P(container) == IS_OBJECT)) {

Zend/zend_execute.h

@@ -71,6 +71,7 @@ ZEND_API ZEND_COLD void zend_throw_ref_type_error_zval(zend_property_info *prop,
 ZEND_API ZEND_COLD void zend_throw_ref_type_error_type(zend_property_info *prop1, zend_property_info *prop2, zval *zv);
 ZEND_API ZEND_COLD zval* ZEND_FASTCALL zend_undefined_offset_write(HashTable *ht, zend_long lval);
 ZEND_API ZEND_COLD zval* ZEND_FASTCALL zend_undefined_index_write(HashTable *ht, zend_string *offset);
+ZEND_API ZEND_COLD void zend_wrong_string_offset_error(void);
 
 ZEND_API ZEND_COLD void ZEND_FASTCALL zend_readonly_property_modification_error(zend_property_info *info);
 

ext/opcache/jit/zend_jit_helpers.c

@@ -864,107 +864,6 @@ static void ZEND_FASTCALL zend_jit_fetch_dim_obj_is_helper(zval *container, zval
 	}
 }
 
-static zend_never_inline ZEND_COLD void zend_wrong_string_offset(void)
-{
-	const char *msg = NULL;
-	const zend_op *opline = EG(current_execute_data)->opline;
-	const zend_op *end;
-	uint32_t var;
-
-	switch (opline->opcode) {
-		case ZEND_ASSIGN_OP:
-		case ZEND_ASSIGN_DIM_OP:
-		case ZEND_ASSIGN_OBJ_OP:
-		case ZEND_ASSIGN_STATIC_PROP_OP:
-			msg = "Cannot use assign-op operators with string offsets";
-			break;
-		case ZEND_FETCH_DIM_W:
-		case ZEND_FETCH_DIM_RW:
-		case ZEND_FETCH_DIM_FUNC_ARG:
-		case ZEND_FETCH_DIM_UNSET:
-		case ZEND_FETCH_LIST_W:
-			/* TODO: Encode the "reason" into opline->extended_value??? */
-			var = opline->result.var;
-			opline++;
-			end = EG(current_execute_data)->func->op_array.opcodes +
-				EG(current_execute_data)->func->op_array.last;
-			while (opline < end) {
-				if (opline->op1_type == IS_VAR && opline->op1.var == var) {
-					switch (opline->opcode) {
-						case ZEND_FETCH_OBJ_W:
-						case ZEND_FETCH_OBJ_RW:
-						case ZEND_FETCH_OBJ_FUNC_ARG:
-						case ZEND_FETCH_OBJ_UNSET:
-						case ZEND_ASSIGN_OBJ:
-						case ZEND_ASSIGN_OBJ_OP:
-						case ZEND_ASSIGN_OBJ_REF:
-							msg = "Cannot use string offset as an object";
-							break;
-						case ZEND_FETCH_DIM_W:
-						case ZEND_FETCH_DIM_RW:
-						case ZEND_FETCH_DIM_FUNC_ARG:
-						case ZEND_FETCH_DIM_UNSET:
-						case ZEND_FETCH_LIST_W:
-						case ZEND_ASSIGN_DIM:
-						case ZEND_ASSIGN_DIM_OP:
-							msg = "Cannot use string offset as an array";
-							break;
-						case ZEND_ASSIGN_OP:
-						case ZEND_ASSIGN_STATIC_PROP_OP:
-							msg = "Cannot use assign-op operators with string offsets";
-							break;
-						case ZEND_PRE_INC_OBJ:
-						case ZEND_PRE_DEC_OBJ:
-						case ZEND_POST_INC_OBJ:
-						case ZEND_POST_DEC_OBJ:
-						case ZEND_PRE_INC:
-						case ZEND_PRE_DEC:
-						case ZEND_POST_INC:
-						case ZEND_POST_DEC:
-							msg = "Cannot increment/decrement string offsets";
-							break;
-						case ZEND_ASSIGN_REF:
-						case ZEND_ADD_ARRAY_ELEMENT:
-						case ZEND_INIT_ARRAY:
-						case ZEND_MAKE_REF:
-							msg = "Cannot create references to/from string offsets";
-							break;
-						case ZEND_RETURN_BY_REF:
-						case ZEND_VERIFY_RETURN_TYPE:
-							msg = "Cannot return string offsets by reference";
-							break;
-						case ZEND_UNSET_DIM:
-						case ZEND_UNSET_OBJ:
-							msg = "Cannot unset string offsets";
-							break;
-						case ZEND_YIELD:
-							msg = "Cannot yield string offsets by reference";
-							break;
-						case ZEND_SEND_REF:
-						case ZEND_SEND_VAR_EX:
-						case ZEND_SEND_FUNC_ARG:
-							msg = "Only variables can be passed by reference";
-							break;
-						case ZEND_FE_RESET_RW:
-							msg = "Cannot iterate on string offsets by reference";
-							break;
-						EMPTY_SWITCH_DEFAULT_CASE();
-					}
-					break;
-				}
-				if (opline->op2_type == IS_VAR && opline->op2.var == var) {
-					ZEND_ASSERT(opline->opcode == ZEND_ASSIGN_REF);
-					msg = "Cannot create references to/from string offsets";
-					break;
-				}
-			}
-			break;
-		EMPTY_SWITCH_DEFAULT_CASE();
-	}
-	ZEND_ASSERT(msg != NULL);
-	zend_throw_error(NULL, "%s", msg);
-}
-
 static zend_never_inline void zend_assign_to_string_offset(zval *str, zval *dim, zval *value, zval *result)
 {
 	zend_string *old_str;
@@ -1092,9 +991,7 @@ static zend_always_inline void ZEND_FASTCALL zend_jit_fetch_dim_obj_helper(zval
 			if (UNEXPECTED(Z_TYPE_P(dim) != IS_LONG)) {
 				zend_check_string_offset(dim/*, BP_VAR_RW*/);
 			}
-			if (!EG(exception)) {
-				zend_wrong_string_offset();
-			}
+			zend_wrong_string_offset_error();
 		}
 		ZVAL_UNDEF(result);
 	} else if (Z_TYPE_P(object_ptr) == IS_FALSE) {
@@ -1225,7 +1122,7 @@ static void ZEND_FASTCALL zend_jit_assign_dim_op_helper(zval *container, zval *d
 			if (UNEXPECTED(Z_TYPE_P(dim) != IS_LONG)) {
 				zend_check_string_offset(dim/*, BP_VAR_RW*/);
 			}
-			zend_wrong_string_offset();
+			zend_wrong_string_offset_error();
 		}
 	} else if (Z_TYPE_P(container) == IS_FALSE) {
 		zend_false_to_array_deprecated();