Language: ReflectionAttribute::newInstance() — instantiate attribute objects (ext/reflection parity)

[PurHur]

Category

language | stdlib

Problem

PHP 8 attributes compile and read via ReflectionClass::getAttributes() + ReflectionAttribute::getName() (#1936 ✅). Zend also supports ReflectionAttribute::newInstance() to construct the attribute class with constructor args from the declaration. Frameworks (DI, routing, validation) depend on newInstance() — without it, attributes are names-only metadata.

#2467 tracks JIT/AOT reflection tables; this issue is the VM semantic for newInstance().

php-src reference

• php/php-src ext/reflection/php_reflection.c — reflection_attribute_get_instance
• php/php-src Zend/zend_attributes.c — stored attribute args + zend_attribute_get_new_instance

Repro (failure today)

<?php
#[Attribute]
class Route {
    public function __construct(public string $path) {}
}
#[Route('/home')]
class C {}
$a = (new ReflectionClass(C::class))->getAttributes()[0];
$o = $a->newInstance();
echo $o->path;

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

Zend PHP: /home
This compiler: fatal (method missing) or wrong behavior

Scope (this repo)

• Store attribute constructor arg expressions on ClassEntry / method metadata (from php-cfg attrGroups)
• lib/VM/Builtin/ReflectionAttributeGetName.php → add newInstance method
• lib/VM/BuiltinClasses.php — register ReflectionAttribute::newInstance
• Evaluate attribute class new with compile-time constant args v1; reject dynamic args with clear error
• test/compliance/cases/language/attribute_new_instance.phpt
• Language: PHP 8 attributes reflection JIT/AOT (phase 2, post-#1354 VM) #2467 for JIT mirror after VM green

Done when

• Repro prints /home on VM
• Repeated newInstance() returns new object instances (Zend semantics)
• Invalid/missing attribute class → ReflectionException matching Zend wording
• ./script/ci-fast.sh --filter attribute_new_instance green

Related

• Language: PHP 8 attributes — JIT/AOT reflection (phase 2 of #1354) #1936 / Language: PHP 8 attributes (#[Attr] on classes, methods, properties) #1354 attribute metadata read path
• Language: PHP 8 attributes reflection JIT/AOT (phase 2, post-#1354 VM) #2467 JIT/AOT reflection phase 2
• Epic: Self-host critical path — compiler compiles itself (M3→M5) #1492 self-host — attributes in lib/ sources

[PurHur]

claim: worker-lane-c — starting this run

[PurHur]

claim: cursor-agent-lane-c — continuing PR #3216 (merge master + verify compliance)

[PurHur]

Verification (cursor-agent-lane-c, this run):

• Merged origin/master into PR Language: ReflectionAttribute::newInstance() VM (#3206) #3216 (39aea3b5).
• Issue repro: VM prints /home from ReflectionAttribute::newInstance().
• Tests green:

  ./script/docker-exec.sh -- bash -lc 'source script/php-env.sh && ./vendor/bin/phpunit test/unit/AttributeReflectionTest.php'
  ./script/docker-exec.sh -- bash -lc 'source script/php-env.sh && ./vendor/bin/phpunit test/compliance/VMTest.php --filter attribute_new_instance'

• Added unit test for missing attribute class (Attribute class "…" not found).

PR #3216 ready for review. JIT newInstance() remains deferred to #2467 per scope.

php-src ref: ext/reflection/php_reflection.c (reflection_attribute_get_instance), Zend/zend_attributes.c

[PurHur]

claim: cursor-agent-lane-c — completing VM nested runFrames + compliance tests (master has newInstance from #3800; second-call bug remains)

[PurHur]

claim: cursor-agent-lane-c — verifying PR #3845 (nested runFrames fix) on branch agent/issue-3206-attribute-newinstance-nested-vm

Verification (this run):

• Root cause confirmed on master: second newInstance() fails with ReflectionAttribute::newInstance() requires active VM because nested runFrames() clears VM::$running in finally.
• Fix branch: save/restore VM::$running across nested runFrames() — matches Zend reflection_attribute_get_instance for repeated calls.
• Repro: bool(false) + /home (distinct instances, correct path).
• Tests green:

  ./script/docker-exec.sh -- bash -lc 'source script/php-env.sh && php vendor/bin/phpunit test/unit/AttributeReflectionTest.php --filter NewInstance'
  ./script/docker-exec.sh -- bash -lc 'source script/php-env.sh && php vendor/bin/phpunit test/compliance/VMTest.php --filter attribute_new_instance'

All #3206 done-when criteria met on PR #3845. Core newInstance() lowering from #3800/#3810; this PR closes the repeated-call VM bug. JIT deferred to #2467 per scope.

php-src ref: ext/reflection/php_reflection.c, Zend/zend_attributes.c