Language: clone with syntax (clone($obj, ['prop'])) — parse fails despite runtime support (PHP 8.4, Zend/zend_language_parser.y) #9743

Category

language · php-src-strict

Problem

PHP 8.4 clone($object, ['prop', ...]) (clone-with) lets callers reinitialize selected properties on a cloned object — notably readonly properties that would otherwise stay frozen after clone.

This compiler already has runtime support (lib/VM/CloneWithSupport.php, lib/JIT/Builtin/CloneWithReinitRuntime.php, ext/standard/CloneWithJitHelper.php, issue #9717 for AOT LLVM routing), but the parser rejects the syntax before compile:

Syntax error, unexpected ',' on line N

Workers cannot exercise clone-with end-to-end until parse + compile lowering accept the second argument.

php-src reference

• php/php-src Zend/zend_language_parser.y — clone_expr with optional property list
• php/php-src Zend/zend_compile.c — zend_compile_clone() property reinit list
• php/php-src Zend/zend_objects.c — zend_objects_clone_obj_with() / IS_PROP_REINITABLE

Repro (failure today)

Save as test/repro/maintainer_gap_clone_with_syntax.php:

<?php
declare(strict_types=1);

class W {
    public int $a = 1;
    public readonly int $b;

    public function __construct() {
        $this->b = 2;
    }
}

$w = new W();
$w2 = clone($w, ['a']);
echo $w2->a, ',', $w2->b, "\n";

php test/repro/maintainer_gap_clone_with_syntax.php
# Zend PHP 8.4+: 1,2  (readonly b copied; a reinitialized)

./script/docker-exec.sh php bin/vm.php test/repro/maintainer_gap_clone_with_syntax.php
# VM: PhpParser Syntax error, unexpected ',' — parse fails

Scope (PHP-in-PHP first)

Do not add new C in runtime/ — reuse existing PHP helpers (#9717).

Done when

• Repro compiles and prints 1,2 on VM (php-src-strict)
• Readonly property outside clone-with list stays immutable after clone
• ./script/ci-fast.sh --filter clone_with green
• JIT/AOT agree when both in scope (reuse php-in-php: AOT CloneWithReinitRuntimeLlvm — route standalone clone-with reinit through CloneWithJitHelper PHP (#1492) #9717 helper path)

Related

• php-in-php: AOT CloneWithReinitRuntimeLlvm — route standalone clone-with reinit through CloneWithJitHelper PHP (#1492) #9717 — AOT standalone LLVM → PHP helper routing (runtime half)
• Language: clone with — readonly property overrides must succeed during reinit window (zend_objects_clone_obj_with) #7250 — readonly reinit window semantics
• North star Epic: Self-host critical path — compiler compiles itself (M3→M5) #1492