Autovivify via a handler

Author: Girgias

Zend/tests/offsets/auto-vivification-objects.phpt

@@ -3,7 +3,7 @@ Auto-vivification for objects
 --FILE--
 <?php
 
-class Vector implements DimensionFetchable, DimensionWritable, FetchAppendable {
+class Vector implements DimensionFetchable, DimensionWritable, FetchAppendable, Autovivificapable {
     private array $a = [];
 
     private function dumpCall($method): void {
@@ -35,6 +35,10 @@ class Vector implements DimensionFetchable, DimensionWritable, FetchAppendable {
         $ref =& $this->a[];
         return $ref;
     }
+    public function autovivify(null &$ref): void {
+        $this->dumpCall(__METHOD__);
+        $ref = new self();
+    }
 }
 
 $obj = new Vector();
@@ -54,8 +58,10 @@ var_dump($obj[2]);
 Object ID #1 called Vector::offsetFetch
 NULL
 Object ID #1 called Vector::offsetFetch
+Object ID #1 called Vector::autovivify
 Object ID #2 called Vector::append
 Object ID #1 called Vector::offsetFetch
+Object ID #1 called Vector::autovivify
 Object ID #3 called Vector::offsetSet
 Check results
 Object ID #1 called Vector::offsetGet

Zend/zend_dimension_handlers.h

@@ -34,6 +34,7 @@ typedef struct _zend_internal_class_dimensions_functions {
 	void  (*/* const */ append)(zend_object *object, zval *value);
 	zval *(*/* const */ fetch_append)(zend_object *object, zval *rv);
 	void  (*/* const */ unset_dimension)(zend_object *object, zval *offset);
+	void  (*/* const */ autovivify)(zend_object *object, zval *reference);
 } zend_internal_class_dimensions_functions;
 
 typedef struct _zend_user_class_dimensions_functions {
@@ -44,6 +45,7 @@ typedef struct _zend_user_class_dimensions_functions {
 	zend_function *append;
 	zend_function *fetch_append;
 	zend_function *unset_dimension;
+	zend_function *autovivify;
 } zend_user_class_dimensions_functions;
 
 ZEND_API zval* zend_class_read_dimension(zend_object *object, zval *offset, zval *rv);
@@ -53,6 +55,7 @@ ZEND_API void  zend_class_write_dimension(zend_object *object, zval *offset, zva
 ZEND_API void  zend_class_append(zend_object *object, zval *value);
 ZEND_API zval *zend_class_fetch_append(zend_object *object, zval *rv);
 ZEND_API void  zend_class_unset_dimension(zend_object *object, zval *offset);
+ZEND_API void  zend_class_autovivify(zend_object *object, zval *reference);
 
 /* VM and JIT Helper */
 ZEND_API bool zend_class_isset_empty_dimension(zend_object *object, zval *offset, bool is_empty);

Zend/zend_execute.c

@@ -3065,11 +3065,11 @@ static zend_never_inline void zend_fetch_object_dimension_address(zval *result,
 		/* Check if we need to auto-vivify a possible null return */
 		if (UNEXPECTED(
 			opline->extended_value == ZEND_FETCH_DIM_DIM
-			&& Z_ISREF_P(result)
-			&& Z_ISNULL_P(Z_REFVAL_P(result))
+			&& obj->ce->dimension_handlers->autovivify
+			&& Z_ISREF_P(retval)
+			&& Z_ISNULL_P(Z_REFVAL_P(retval))
 		)) {
-			// TODO THIS IS A VERY CRUDE PROTOTYPE
-			object_init_ex(Z_REFVAL_P(result), obj->ce);
+			zend_class_autovivify(obj, retval);
 		}
 		if (result != retval) {
 			ZVAL_INDIRECT(result, retval);

Zend/zend_interfaces_dimension.c

@@ -33,6 +33,7 @@ ZEND_API zend_class_entry *zend_ce_dimension_write;
 ZEND_API zend_class_entry *zend_ce_dimension_unset;
 ZEND_API zend_class_entry *zend_ce_appendable;
 ZEND_API zend_class_entry *zend_ce_dimension_fetch_append;
+ZEND_API zend_class_entry *zend_ce_autovivificapable;
 
 ZEND_API zval* zend_class_read_dimension(zend_object *object, zval *offset, zval *rv) {
 	if (object->ce->type == ZEND_USER_CLASS) {
@@ -257,6 +258,20 @@ ZEND_API void zend_class_unset_dimension(zend_object *object, zval *offset)
 	}
 }
 
+ZEND_API void zend_class_autovivify(zend_object *object, zval *reference)
+{
+	if (object->ce->type == ZEND_USER_CLASS) {
+		zend_function *zf = object->ce->dimension_functions->autovivify;
+		ZEND_ASSERT(zf);
+		GC_ADDREF(object);
+		zend_call_known_instance_method_with_1_params(zf, object, /* retval */ NULL, reference);
+		OBJ_RELEASE(object);
+	} else {
+		ZEND_ASSERT(object->ce->type == ZEND_INTERNAL_CLASS);
+		object->ce->dimension_handlers->autovivify(object, reference);
+	}
+}
+
 /* rv is a slot provided by the callee that is returned */
 static zval *zend_user_class_read_dimension(zend_object *object, zval *offset, zval *rv)
 {
@@ -547,6 +562,19 @@ static int zend_implement_dimension_fetch_append(zend_class_entry *interface, ze
 	return SUCCESS;
 }
 
+static int zend_implement_autovivificapable(zend_class_entry *interface, zend_class_entry *class_type)
+{
+	if (class_type->type == ZEND_INTERNAL_CLASS) {
+		return SUCCESS;
+	}
+
+	zend_user_class_dimensions_functions *funcs = NULL;
+	ALLOC_HANDLERS_IF_MISSING(funcs, class_type);
+
+	funcs->autovivify = zend_hash_str_find_ptr(&class_type->function_table, "autovivify", strlen("autovivify"));
+	return SUCCESS;
+}
+
 ZEND_API void zend_register_dimension_interfaces(void)
 {
 	zend_ce_dimension_read = register_class_DimensionReadable();
@@ -569,4 +597,7 @@ ZEND_API void zend_register_dimension_interfaces(void)
 
 	zend_ce_arrayaccess = register_class_ArrayAccess(zend_ce_dimension_read, zend_ce_dimension_write, zend_ce_dimension_unset);
 	zend_ce_arrayaccess->interface_gets_implemented = zend_implement_arrayaccess;
+
+	zend_ce_autovivificapable = register_class_Autovivificapable();
+	zend_ce_autovivificapable->interface_gets_implemented = zend_implement_autovivificapable;
 }

Zend/zend_interfaces_dimension.h

@@ -32,6 +32,7 @@ extern ZEND_API zend_class_entry *zend_ce_dimension_write;
 extern ZEND_API zend_class_entry *zend_ce_dimension_unset;
 extern ZEND_API zend_class_entry *zend_ce_appendable;
 extern ZEND_API zend_class_entry *zend_ce_dimension_fetch_append;
+extern ZEND_API zend_class_entry *zend_ce_autovivificapable;
 
 ZEND_API void zend_register_dimension_interfaces(void);
 

Zend/zend_interfaces_dimensions.stub.php

@@ -34,6 +34,11 @@ interface FetchAppendable extends Appendable
     public function &fetchAppend(): mixed;
 }
 
+interface Autovivificapable
+{
+    public function autovivify(null &$ref): void;
+}
+
 interface ArrayAccess extends DimensionReadable, DimensionWritable, DimensionUnsetable
 {
     /** @tentative-return-type */