Regression: constructor-promoted asymmetric visibility public private(set) — compile fatal (re-#4690) #6981

Category

language · php-src-strict

Problem

PHP 8.4 allows asymmetric visibility on constructor-promoted properties, e.g. public function __construct(public private(set) string $name). Non-promoted public private(set) string $name compiles and enforces correctly on VM today, but the promoted form fails at compile with:

Multiple access type modifiers are not allowed

Closed #4690 tracked this gap; the parser/rewriter still rejects valid php-src syntax, blocking PHP 8.4 parity and self-host code using promoted asymmetric properties.

php-src reference

• php/php-src Zend/zend_compile.c — promoted parameter → property with asymmetric set visibility
• php/php-src Zend/zend_object_handlers.c — external write rejection on private(set)
• RFC: Asymmetric Visibility

Repro (failure today)

<?php
class User {
    public function __construct(
        public private(set) string $name,
    ) {}
}
$u = new User('alice');
echo $u->name, "\n";
try {
    $u->name = 'bob';
} catch (Error $e) {
    echo $e->getMessage(), "\n";
}

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

Control (works today): non-promoted public private(set) string $name = 'x'; in the same file compiles and throws on external write.

Also fails: public readonly private(set) on promoted parameters (same parse fatal).

Scope (this repo)

PHP-in-PHP: no new C runtime branches.

Done when

• Repro compiles on VM, JIT, and AOT
• External $u->name = 'bob' throws catchable Error matching Zend message
• Writes from inside class / constructor still allowed
• Non-promoted asymmetric properties remain green (no regression)
• ./script/ci-fast.sh --filter asymmetric_visibility_promoted green

Verification

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

Related

• Language: asymmetric visibility on constructor-promoted properties (zend_compile.c parity) #4690 (closed prematurely) · Language: property hooks with asymmetric set visibility set (protected) => — parse fails (zend_property_hooks.c) #6898 asymmetric set visibility parse · Language: PHP 8.4 asymmetric property visibility (public/private(set), etc.) #3165 / Language: PHP 8.4 asymmetric visibility private(set) — JIT enforce + catchable Error (phase 2 of #3165) #4029 base asymmetric · Language: constructor property promotion — non-readonly classes fail with Missing required argument 0 (zend_compile.c) #4770 promoted ctor · Epic: Self-host critical path — compiler compiles itself (M3→M5) #1492