Language: list()/array destructuring on property hooks must use get/set hooks (zend_property_hooks.c)

[PurHur]

Category

language

Problem

PHP 8.4 property hooks must participate in list destructuring and array destructuring ([$obj->prop] = …, […, $obj->prop, …] = …). Zend invokes the set hook on assignment targets and the get hook when a hooked property is read as a destructuring source.

This compiler lowers hooks via lib/SourcePreprocessor/PropertyHooks.php + indirect writes in lib/VM.php, but list/array destructuring still writes backing storage (or skips hooks), diverging from php-src.

Pairs with #6426 (by-ref assign), #6427 (compound assign), #6424 (++/--) — same zend_property_hooks.c dispatch family.

php-src reference

• php/php-src Zend/zend_property_hooks.c — hooked lvalue assignment paths
• php/php-src Zend/zend_execute.c — ZEND_ASSIGN_DIM, list assign opcodes
• php/php-src Zend/zend_compile.c — destructuring compile

Repro

Save as test/repro-maintainer/parity_property_hook_list_destructure.php:

<?php
class Box {
    private string $_v = '';
    public string $label {
        get => $this->_v;
        set => $this->_v = '[' . $value . ']';
    }
}
$c = new Box();
[$c->label] = ['hi'];
echo $c->label, "\n";

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

Runtime	Output
Zend PHP 8.4+	[hi] (set hook ran)
VM today	likely hi or hook bypass (wrong)

Compliance: add test/compliance/cases/language/property_hook_list_destructure.phpt

Scope (this repo)

Path	Work
lib/VM.php	List/assign lowering — route hooked property lvalues through set hook
lib/JIT/PropertyHookDispatch.php	Mirror for JIT/AOT when destructuring is lowered
lib/Compiler.php	Ensure list targets on hooked props emit hook-aware stores
Tests	VM + JIT PHPT (JIT may defer if Block::requiresVmLowering)

PHP-in-PHP first — no new C runtime branches.

Done when

• Repro prints [hi] on VM matching Zend
• Nested/mixed list with hooked + plain props matches Zend on tested subset
• ./script/ci-fast.sh --filter property_hook_list green
• JIT/AOT documented in matrix (native lowering or VM deferral with issue link)

Verification

./script/docker-exec.sh -- bash -lc 'source script/php-env.sh && vendor/bin/phpunit --filter property_hook_list'

Related

• Language: increment/decrement on property hooks — must use get/set hooks (zend_property_hooks.c) #6424, Language: by-reference assignment to property hooks must invoke set hook (zend_property_hooks.c) #6426, Language: compound assignment (+=, .=, …) on property hooks must use get/set hooks (zend_property_hooks.c) #6427, Language: property hook set (arrow syntax) — assignment must invoke set hook (zend_property_hooks.c) #6409, Epic: Self-host critical path — compiler compiles itself (M3→M5) #1492

[PurHur]

claim: worker-lane-c — starting this run

[PurHur]

Merged via #6462

Root cause: php-cfg emits PropertyFetch between ArrayDimFetch and Assign for hooked list slots; keyed destructuring was not recognized as a list-destruct group, triggering the string-key CFG split and bypassing set hooks.

Fix: listDestructSlotAssignIndex() skips optional property-fetch prelude ops when detecting list-destruct slots.

Verification:

./script/docker-exec.sh -- bash -lc 'source script/php-env.sh
php bin/vm.php test/repro-maintainer/parity_property_hook_list_destructure.php
vendor/bin/phpunit --filter property_hook_list
'

→ repro prints [hi]; compliance PHPT green (int/mixed/keyed cases).