Repository navigation
Stdlib: gc_disable/gc_enable/gc_enabled/gc_collect_cycles — JIT/AOT (ext/standard + Zend/zend_gc.c) #4023
Description
Category
stdlib / runtime
Problem
Garbage-collection introspection builtins gc_disable(), gc_enable(), gc_enabled(), and gc_collect_cycles() run on VM (ext/standard/gc_*.php) but docs/capabilities.md marks them JIT=no. Long-running JIT/AOT services that toggle GC or collect cycles (tests, workers) silently diverge from Zend when executed natively.
php-src reference
- php/php-src
ext/standard/basic_functions.c—PHP_FUNCTION(gc_collect_cycles),gc_enable,gc_disable,gc_enabled - php/php-src
Zend/zend_gc.c— cycle collector,GC_G(enabled)
Repro
<?php
class Node { public ?Node $next = null; }
$a = new Node();
$b = new Node();
$a->next = $b;
$b->next = $a;
unset($a, $b);
echo gc_enabled() ? "on\n" : "off\n";
gc_disable();
echo gc_enabled() ? "on\n" : "off\n";
gc_enable();
echo gc_collect_cycles(), "\n";./script/docker-exec.sh -- bash -lc 'source script/php-env.sh
php bin/vm.php repro.php
php bin/jit.php repro.php 2>&1
'| Call | Zend (typical) | VM | JIT gap |
|---|---|---|---|
gc_enabled() before disable |
on |
✅ | must match |
after gc_disable() |
off |
✅ | must match |
gc_collect_cycles() after cycle |
>= 1 |
✅ | must match |
Scope
| Path | Work |
|---|---|
| VM reference | ext/standard/gc_disable.php, gc_enable.php, gc_enabled.php, gc_collect_cycles.php |
| JIT | lib/JIT/Builtin/ handlers calling lib/VM/GcSupport.php (or existing VM registry hooks) |
| AOT | link same C/VM helpers as other builtins |
| Tests | test/compliance/cases/stdlib/gc_jit.phpt |
Done when
- JIT repro prints same three-state
gc_enabledlines and non-negativegc_collect_cycles()as VM - Capability matrix: all four functions JIT=yes (AOT if applicable)
- WeakRef tests still pass after collection (
WeakReferenceLanguage JIT: WeakMap / WeakReference LLVM lowering (phase 2 of #3282) #3667)
Related
- WeakReference / WeakMap: Language JIT: WeakMap / WeakReference LLVM lowering (phase 2 of #3282) #3667
get_mangled_object_varsJIT (similar pattern): separate issue if needed
Activity
Language: close #4096 — gc cycle destruct + capability doc sync (#4222)
PurHur commentedon Jun 13, 2026
claim: PHP Runtime → PHP — starting this run (#4023: gc_* JIT/AOT compliance tests + fix gc_enabled.phpt Mixed_ compile failure).
Close #4023: fix gc compliance PHPTs and add gc_jit.phpt (#8409)
PurHur commentedon Jun 13, 2026
Merged via #8409
Verification
→ OK (3 tests). JIT inline repro:
on/off/0.Implementation: GC JIT/AOT was already on master (
GcCollectCyclesRuntime,JitGcToggle,JitGcCollectCycles). This PR fixes compliance PHPT compile failures (Mixed_from untypedNode::$next) and addsgc_jit.phpt. No C runtime changes.