Repository navigation
modify readonly class property with reference #10844
Description
Description
The following code:
<?php
readonly class A implements IteratorAggregate {
function __construct(readonly public string $foo = 'bar') {}
function getIterator() : Traversable {
return new ArrayIterator($this);
}
}
$obj = new A;
//$obj->foo = 'baz'; // expected fatal error
//$prop = &$obj->foo; // expected fatal error
foreach ($obj as $k => &$v) {
$v = 'baz';
}
var_dump($obj);Resulted in this output:
object(A)#1 (1) {
["foo"]=>
&string(3) "baz"
}
But I expected this output instead:
Fatal error: Uncaught Error: Cannot modify readonly property A::$foo
PHP Version
8.2.3
Operating System
No response
Activity
ndossche commentedon Mar 13, 2023
Looks very related to #9432
iluuu1994 commentedon Mar 17, 2023
Also related, it's possible to skip the reference type check:
iluuu1994 commentedon Mar 17, 2023
This seems fairly difficult to fix. The problem is that
ArrayIteratorcopies the properties array without knowing whether the operation isRorRWandZEND_FE_FETCH_RWconverts the given value to a reference without knowing that the value came from an object. Thus we can neither trivially check if the property isreadonly, nor add theZEND_REF_ADD_TYPE_SOURCEwhen the value is converted to a reference.We could specifically fix this for
ArrayIterator, which I tried here:master...iluuu1994:php-src:gh-10844
It's not pretty but I don't know how else we could solve this without modifying both the iterator API and the internals of spl_object quite heavily.