Language: foreach on array literal with enum case key — must TypeError not coerce to backing scalar (Zend/zend_hash.c) #10363

Category

language · php-src-strict

Problem

#9512 tracks array literal construction coercing enum case keys to backing scalars. A related runtime symptom: foreach ([E::A => 1] as $k => $v) on this compiler iterates with $k as the backing int 1. Zend rejects the array at runtime with TypeError: Illegal offset type when the illegal key is encountered (literal construction path).

Workers should fix literal key rejection (#9512) and ensure foreach never exposes materialized scalar keys for enum-case-keyed arrays.

php-src reference

• php/php-src Zend/zend_hash.c — illegal offset type for enum/object keys
• php/php-src Zend/zend_execute.c — ZEND_FE_FETCH_R key zval
• Related: Regression: foreach over enum-case keyed arrays materializes backing scalar keys (Zend/zend_hash.c) #9792 (reflection-built enum-key arrays)

Repro

<?php
declare(strict_types=1);

enum E: int { case A = 1; }

foreach ([E::A => 1] as $k => $v) {
    var_export($k);
    echo "\n";
}

./script/docker-exec.sh -- bash -lc 'source script/php-env.sh
php -r "enum E: int { case A=1; } foreach ([E::A=>1] as \$k=>\$v) { var_export(\$k); echo PHP_EOL; }" 2>&1 | head -3
php bin/vm.php -r "enum E: int { case A=1; } foreach ([E::A=>1] as \$k=>\$v) { var_export(\$k); echo PHP_EOL; }" 2>&1 | head -3
'

Scope

Done when

• Repro throws TypeError: Illegal offset type on VM (and JIT when lowered)
• Language: array literal enum case keys coerce to backing scalar — must TypeError (Zend/zend_hash.c) #9512 literal [E::A => v] also TypeErrors at compile or first runtime use per Zend
• ./script/docker-exec.sh -- bash -lc 'source script/php-env.sh && vendor/bin/phpunit --filter foreach_enum_case_key' green

Related

• Language: array literal enum case keys coerce to backing scalar — must TypeError (Zend/zend_hash.c) #9512 array literal keys · Regression: foreach over enum-case keyed arrays materializes backing scalar keys (Zend/zend_hash.c) #9792 foreach enum keys · Epic: Self-host critical path — compiler compiles itself (M3→M5) #1492