Language: resource used as array offset TypeError — Zend Warning + int cast (zend_hash.c / zend_execute.c) #29550

Category

language · php-src-strict · array offset / resource · pillar 4

Problem

On Zend 8.2, using a resource as an array offset emits E_WARNING (Resource ID#N used as offset, casting to integer (N)) and stores under the cast integer key. VM/JIT throw TypeError: Illegal offset type and refuse the write — observable control-flow and data divergence (not just message text).

Probed 2026-08-09 @ 092e9d1ee8 vs Zend 8.2.32. JIT matches VM.

php-src reference

• php/php-src Zend/zend_hash.c — resource offset cast / warning
• php/php-src Zend/zend_execute.c — dim assign / isset offset handling
• Related closed (objects/enums, not resources): Language: object used as array key accepted — Zend TypeError Illegal offset type (zend_execute.c / zend_hash.c) #29532, Runtime: object array offset — isset()/array_key_exists() must TypeError (Illegal offset type) #6500, Stdlib: array_flip() — object/resource array keys must throw TypeError (ext/standard/array.c parity) #4268

PHP implementation target

• Match php-src-strict for PHP 8.2 resource offsets: warn + cast to int for write/isset/unset (same resource id), do not TypeError
• PHP-in-PHP in VM/JIT hash/dim helpers; no new C runtime logic

Repro

./script/docker-exec.sh -- bash -lc 'cat > /tmp/resource_key.php <<'"'"'PHP'"'"'
<?php
error_reporting(E_ALL);
$a = [];
$r = fopen("php://memory", "r");
try {
  $a[$r] = 1;
  echo "set:"; var_export($a); echo "\n";
} catch (Throwable $e) {
  echo "set:", get_class($e), ":", $e->getMessage(), "\n";
}
fclose($r);
PHP
php -d zend.exception_ignore_args=0 /tmp/resource_key.php
php -d zend.exception_ignore_args=0 bin/vm.php /tmp/resource_key.php
php -d zend.exception_ignore_args=0 bin/jit.php /tmp/resource_key.php'

Done when

• VM + JIT: resource array offset write matches Zend (Warning + integer key), not TypeError
• isset/unset on resource offset match Zend warn+cast behavior
• Compliance/.phpt or test/repro/ guard
• php-src-strict; no php-compiler-strict shortcut