Deprecate IAP functions on objects

Deprecate use of key(), current(), next(), prev(), reset() and
end() on objects. Cast the object to array first.

Part of https://wiki.php.net/rfc/deprecations_php_8_1.

Author: nikic

UPGRADING

@@ -350,6 +350,12 @@ PHP 8.1 UPGRADE NOTES
   . The PDO::FETCH_SERIALIZE mode has been deprecated.
     RFC: https://wiki.php.net/rfc/phase_out_serializable
 
+- Standard:
+  . Calling  key(), current(), next(), prev(), reset(), or end() on objects
+    is deprecated. Instead cast the object to array first, or make use of
+    ArrayIterator.
+    RFC: https://wiki.php.net/rfc/deprecations_php_8_1
+
 ========================================
 5. Changed Functions
 ========================================

Zend/tests/bug71266.phpt

@@ -16,7 +16,9 @@ $obj = (object) $arr;
 next($obj);
 var_dump(current($arr));
 ?>
---EXPECT--
+--EXPECTF--
 int(1)
 int(42)
+
+Deprecated: next(): Calling next() on an object is deprecated in %s on line %d
 int(1)

Zend/tests/iap_on_object_deprecated.phpt

@@ -0,0 +1,32 @@
+--TEST--
+Using IAP functions on objects is deprecated
+--FILE--
+<?php
+
+$obj = (object)['a' => 'b'];
+var_dump(reset($obj));
+var_dump(current($obj));
+var_dump(key($obj));
+var_dump(next($obj));
+var_dump(end($obj));
+var_dump(prev($obj));
+
+?>
+--EXPECTF--
+Deprecated: reset(): Calling reset() on an object is deprecated in %s on line %d
+string(1) "b"
+
+Deprecated: current(): Calling current() on an object is deprecated in %s on line %d
+string(1) "b"
+
+Deprecated: key(): Calling key() on an object is deprecated in %s on line %d
+string(1) "a"
+
+Deprecated: next(): Calling next() on an object is deprecated in %s on line %d
+bool(false)
+
+Deprecated: end(): Calling end() on an object is deprecated in %s on line %d
+string(1) "b"
+
+Deprecated: prev(): Calling prev() on an object is deprecated in %s on line %d
+bool(false)

ext/standard/array.c

@@ -1041,16 +1041,36 @@ PHP_FUNCTION(uksort)
 }
 /* }}} */
 
+static inline HashTable *get_ht_for_iap(zval *zv, bool separate) {
+	if (EXPECTED(Z_TYPE_P(zv) == IS_ARRAY)) {
+		return Z_ARRVAL_P(zv);
+	}
+
+	ZEND_ASSERT(Z_TYPE_P(zv) == IS_OBJECT);
+	php_error_docref(NULL, E_DEPRECATED,
+		"Calling %s() on an object is deprecated", get_active_function_name());
+
+	zend_object *zobj = Z_OBJ_P(zv);
+	if (separate && zobj->properties && UNEXPECTED(GC_REFCOUNT(zobj->properties) > 1)) {
+		if (EXPECTED(!(GC_FLAGS(zobj->properties) & IS_ARRAY_IMMUTABLE))) {
+			GC_DELREF(zobj->properties);
+		}
+		zobj->properties = zend_array_dup(zobj->properties);
+	}
+	return zobj->handlers->get_properties(zobj);
+}
+
 /* {{{ Advances array argument's internal pointer to the last element and return it */
 PHP_FUNCTION(end)
 {
-	HashTable *array;
+	zval *array_zv;
 	zval *entry;
 
 	ZEND_PARSE_PARAMETERS_START(1, 1)
-		Z_PARAM_ARRAY_OR_OBJECT_HT_EX(array, 0, 1)
+		Z_PARAM_ARRAY_OR_OBJECT_EX(array_zv, 0, 1)
 	ZEND_PARSE_PARAMETERS_END();
 
+	HashTable *array = get_ht_for_iap(array_zv, /* separate */ true);
 	zend_hash_internal_pointer_end(array);
 
 	if (USED_RET()) {
@@ -1070,13 +1090,14 @@ PHP_FUNCTION(end)
 /* {{{ Move array argument's internal pointer to the previous element and return it */
 PHP_FUNCTION(prev)
 {
-	HashTable *array;
+	zval *array_zv;
 	zval *entry;
 
 	ZEND_PARSE_PARAMETERS_START(1, 1)
-		Z_PARAM_ARRAY_OR_OBJECT_HT_EX(array, 0, 1)
+		Z_PARAM_ARRAY_OR_OBJECT_EX(array_zv, 0, 1)
 	ZEND_PARSE_PARAMETERS_END();
 
+	HashTable *array = get_ht_for_iap(array_zv, /* separate */ true);
 	zend_hash_move_backwards(array);
 
 	if (USED_RET()) {
@@ -1096,13 +1117,14 @@ PHP_FUNCTION(prev)
 /* {{{ Move array argument's internal pointer to the next element and return it */
 PHP_FUNCTION(next)
 {
-	HashTable *array;
+	zval *array_zv;
 	zval *entry;
 
 	ZEND_PARSE_PARAMETERS_START(1, 1)
-		Z_PARAM_ARRAY_OR_OBJECT_HT_EX(array, 0, 1)
+		Z_PARAM_ARRAY_OR_OBJECT_EX(array_zv, 0, 1)
 	ZEND_PARSE_PARAMETERS_END();
 
+	HashTable *array = get_ht_for_iap(array_zv, /* separate */ true);
 	zend_hash_move_forward(array);
 
 	if (USED_RET()) {
@@ -1122,13 +1144,14 @@ PHP_FUNCTION(next)
 /* {{{ Set array argument's internal pointer to the first element and return it */
 PHP_FUNCTION(reset)
 {
-	HashTable *array;
+	zval *array_zv;
 	zval *entry;
 
 	ZEND_PARSE_PARAMETERS_START(1, 1)
-		Z_PARAM_ARRAY_OR_OBJECT_HT_EX(array, 0, 1)
+		Z_PARAM_ARRAY_OR_OBJECT_EX(array_zv, 0, 1)
 	ZEND_PARSE_PARAMETERS_END();
 
+	HashTable *array = get_ht_for_iap(array_zv, /* separate */ true);
 	zend_hash_internal_pointer_reset(array);
 
 	if (USED_RET()) {
@@ -1148,13 +1171,14 @@ PHP_FUNCTION(reset)
 /* {{{ Return the element currently pointed to by the internal array pointer */
 PHP_FUNCTION(current)
 {
-	HashTable *array;
+	zval *array_zv;
 	zval *entry;
 
 	ZEND_PARSE_PARAMETERS_START(1, 1)
-		Z_PARAM_ARRAY_OR_OBJECT_HT(array)
+		Z_PARAM_ARRAY_OR_OBJECT(array_zv)
 	ZEND_PARSE_PARAMETERS_END();
 
+	HashTable *array = get_ht_for_iap(array_zv, /* separate */ false);
 	if ((entry = zend_hash_get_current_data(array)) == NULL) {
 		RETURN_FALSE;
 	}
@@ -1170,12 +1194,13 @@ PHP_FUNCTION(current)
 /* {{{ Return the key of the element currently pointed to by the internal array pointer */
 PHP_FUNCTION(key)
 {
-	HashTable *array;
+	zval *array_zv;
 
 	ZEND_PARSE_PARAMETERS_START(1, 1)
-		Z_PARAM_ARRAY_OR_OBJECT_HT(array)
+		Z_PARAM_ARRAY_OR_OBJECT(array_zv)
 	ZEND_PARSE_PARAMETERS_END();
 
+	HashTable *array = get_ht_for_iap(array_zv, /* separate */ false);
 	zend_hash_get_current_key_zval(array, return_value);
 }
 /* }}} */