Language: clone with partial property list (PHP 8.4) — syntax + readonly reinit semantics (Zend/zend_clones.c) #10310

Category

language · php-src-strict · PHP 8.4

Problem

PHP 8.4 adds clone($obj, ['prop', ...]) to reinitialize selected properties (notably readonly properties) on the clone. This compiler accepts the syntax on the 8.4 target and executes, but parity vs php-src is unverified:

• Zend 8.2 (Docker reference) rejects parse — expected until 8.4.
• VM runs clone($w, ['a']) and prints 1,2 (php-in-php: JIT CloneWithReinitRuntime — shrink clone-with readonly reinit LLVM glue via CloneWithSupport PHP (#1492) #10002 tracks JIT glue only).

Workers need language semantics: which properties re-run default/constructor init, readonly rules, and whether the source object is mutated.

php-src reference

• php/php-src Zend/zend_clones.c — ZEND_CLONE_WITH, readonly reinit
• php/php-src Zend/zend_compile.c — clone with second argument parse
• RFC: PHP 8.4 clone() with property list

Repro

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";

Extended state check (add to repro or compliance test):

var_export([$w->a, $w->b, $w2->a, $w2->b]);

./script/docker-exec.sh -- bash -lc 'source script/php-env.sh
php bin/vm.php test/repro/maintainer_gap_clone_with_syntax.php
'

Compare against php-src 8.4 Zend build or upstream Zend/tests/clones/clone_with*.phpt when available.

Scope (PHP-in-PHP)

Done when (php-src-strict)

• Repro output matches php-src 8.4 Zend for $w2 property values
• Source $w object state matches Zend (no spurious mutation)
• Invalid property names in list throw/errors per Zend
• ./script/ci-fast.sh --filter clone_with green

Related

• php-in-php: JIT CloneWithReinitRuntime — shrink clone-with readonly reinit LLVM glue via CloneWithSupport PHP (#1492) #10002 php-in-PHP JIT glue · php-in-php: JIT ReadonlyRaise — route readonly property write errors through Vm PHP not ~385-line LLVM (#1492) #9522 readonly errors · Epic: Self-host critical path — compiler compiles itself (M3→M5) #1492