Language: get-only property hook isset/empty must invoke get hook (Zend/zend_property_hooks.c)

[PurHur]

Category

language · php-src-strict · PHP 8.4 property hooks

Problem

For a get-only hooked property (no backing field, hook returns a value):

class C {
    public int $x {
        get => 1;
    }
}

Zend routes isset($c->x) and empty($c->x) through the get hook (value 1 → isset true, empty false).

This compiler skips the hook:

• isset($c->x) → false
• empty($c->x) → true

Distinct from #9696 (initialized private backing + get/set hooks) which failed compile due to #9830-class redeclare errors.

php-src reference

• php/php-src Zend/zend_property_hooks.c — isset / empty on virtual properties

Repro (failure today)

<?php
class C {
    public int $x {
        get => 1;
    }
}
$c = new C();
var_dump(isset($c->x));
var_dump(empty($c->x));

./script/docker-exec.sh -- bash -lc 'source script/php-env.sh
php bin/vm.php repro_getonly_hook_isset.php
'

Engine	isset	empty
Zend PHP 8.4+	true	false
VM today	false	true

Scope

• lib/VM.php — isset / empty opcodes on hooked properties without backing
• lib/JIT.php — mirror VM when JIT lowers isset/empty on hooks
• test/compliance/cases/language/property_hook_getonly_isset_empty.phpt

Done when

• Repro dumps match Zend on VM
• ./script/ci-fast.sh --filter property_hook_getonly_isset green

Related

• Language: property hook isset/empty on initialized backing — must invoke get hook (Zend/zend_property_hooks.c) #9696 (closed — initialized backing path) · Language: unset() on get-only property hook — must Error before unset, not read-only property conflation (Zend/zend_property_hooks.c) #9800 unset on get-only · #1492

[PurHur]

claim: worker-lane-c — starting this run (language/VM scope; get-only hook isset/empty parity)

[PurHur]

Merged via #9891.

Verification (docker-exec):

source script/php-env.sh
php bin/vm.php test/repro/maintainer_property_hook_getonly_isset_empty.php
vendor/bin/phpunit --filter "property_hook_getonly_isset|property_hook_isset|property_hook_empty|property_hooks_isset"

Output:

bool(true)
bool(false)
OK (4 tests, 4 assertions)

Virtual get-only hooks (propertyHookVirtual) now invoke get for isset/empty; non-virtual uninitialized backing probes unchanged (#9696).