Regression: AOT LimitIterator/AppendIterator fail — missing __generator_resume metadata (ext/spl/spl_iterators.c)

[PurHur]

Category

bug · php-src-strict · stdlib · user-script AOT · pillar 4

Problem

LimitIterator / AppendIterator / RegexIterator wrapping ArrayIterator match Zend on VM/JIT (iterator_to_array output correct), but user-script AOT aborts with Generator missing __generator_resume metadata in JIT (exit 2, no binary).

Distinct from #26785 (IteratorAggregate segfault after build) — these fail before emit completes.

Probed 2026-08-02 @ 2a36d3a43.

Repro	Zend / VM / JIT	AOT (2026-08-02)
LimitIterator(ArrayIterator([1..5]), 1, 2) → iterator_to_array	2,3	BUILD fail: missing __generator_resume metadata
AppendIterator of two ArrayIterators	1,2,3	same
RegexIterator(..., '/^b/')	bar,baz	same

php-src reference

• php/php-src ext/spl/spl_iterators.c — LimitIterator / AppendIterator / RegexIterator
• php/php-src ext/spl/spl_iterators.stub.php

PHP implementation target

• AOT/JIT iterator lowering must register resume metadata for SPL outer iterators (not only PHP generators) — lib/JIT/IteratorHelper.php / SPL iterator helpers in ext/spl/
• PHP-in-PHP; no new runtime/*.c

Repro

./script/docker-exec.sh -- bash -lc '
cat > /tmp/li.php <<'"'"'PHP'"'"'
<?php
$it = new LimitIterator(new ArrayIterator([1,2,3,4,5]), 1, 2);
echo implode(\",\", iterator_to_array($it)), \"\n\";
PHP
php /tmp/li.php
php bin/vm.php /tmp/li.php
php bin/jit.php /tmp/li.php
php bin/compile.php -o /tmp/li /tmp/li.php
'

Done when

• AOT build succeeds and prints 2,3 matching Zend/VM/JIT
• AppendIterator / RegexIterator smoke also green (same metadata root)
• Compliance or test/repro/ guard
• php-src-strict; no php-compiler-strict shortcut

[PurHur]

claim: PHP Compiler STD Lib Advanced — batch (issues #26785, #26790, #26793, #26823, #26825)

[PurHur]

handoff: batch paused after #26785+#26790 merged; #26825 LimitIterator still open.

[PurHur]

claim: PHP Compiler STD Lib Advanced — batch (issues #26793, #26823, #26825)

TRY_FIRST:

Gate	Status
docker info	ok
master	synced @ 364868532

Continuing paused SPL AOT batch: #26793 (SplFixedArray::fromArray) first, then #26823 / #26825. Leaving #26861 to Runtime→PHP WIP PR #26902.

[PurHur]

claim: PHP Compiler STD Lib Advanced — continuing batch after #26823 merged (PR #26920); starting #26825 LimitIterator/AppendIterator/RegexIterator AOT

[PurHur]

handoff: #26825 WIP on agent/advanced-stdlib-26825-spl-outer-iterators — not green yet

Root cause (confirmed)

iterator_to_array AOT took materializeFromIteratorProtocol → sole Generator::rewind candidate (Builder/resume metadata error).

Fixes landed in tree (partial)

• Refuse sole-Generator iterator-protocol candidate (VmIteratorProtocol)
• Pass CFG operand userType into ITA via Context::$jitIteratorToArrayIteratorOperand (same pattern as json_encode)
• HT-backed path for SPL outer iterators + ArrayIterator/ArrayObject (SplOuterIteratorHt, JitIteratorToArray::materializeFromSplHt)
• Seed + construct proxies for LimitIterator / AppendIterator / RegexIterator (__spl_ht snapshot)
• ArrayIterator iterator_to_array AOT now works (was same Generator false path)

Blocker

LimitIterator::__construct runs (argc=4, props=__spl_ht@Slot0). Storing any HT (even HashTableHelper::alloc() empty) then iterator_to_array($limitIt) segfaults at runtime. Same propertyStore pattern works for ArrayIterator.

Next: compare IR/allocate size for new LimitIterator vs new ArrayIterator property slot write/load; or NestedJIT VM LimitIteratorBuiltin walk instead of thin HT snapshot.

Repro still red

./script/docker-exec.sh -- bash -lc 'source script/php-env.sh
export PHP_COMPILER_PROFILE=8.4
php bin/compile.php -o /tmp/li test/repro/maintainer_gap_aot_spl_outer_iterators.php && /tmp/li'