Regression: class_alias() on enums — case fetch via alias returns backing scalar not enum object (re-#5765, zend_API.c)

[PurHur]

Category

stdlib — php-src-strict enum alias resolution

Problem

class_alias('E', 'EAlias') registers the alias (closed #5765), but fetching a case through the alias (EAlias::A) returns the backing scalar (int(1)) instead of the enum case object. Zend returns enum(E::A) and EAlias::A === E::A is identity-true.

Compliance test/compliance/cases/stdlib/class_alias_enum.phpt currently fails alongside enum case TypeError guards.

php-src reference

• Zend/zend_API.c — zend_register_class_alias_ex() / enum class entries
• Zend/zend_enum.c — enum case lookup through aliased class names

Repro

./script/docker-exec.sh -- bash -lc 'source script/php-env.sh && php bin/vm.php -r '"'"'enum E:int{case A=1;} class_alias("E","EAlias"); var_dump(EAlias::A); var_dump(EAlias::A === E::A);'"'"''

Zend:

enum(E::A)
bool(true)

This compiler (bin/vm.php):

int(1)
bool(false)

Full compliance:

php bin/vm.php test/compliance/cases/stdlib/class_alias_enum.phpt

Scope (PHP-in-PHP)

• ext/standard/class_alias.php, ext/standard/VmClassAlias.php (if present)
• lib/VM/Context.php — registerClassAlias for enums
• lib/JIT/Builtin/Type/Object_.php — enum case fetch through aliased ClassEntry
• ext/standard/JitClassAlias.php — JIT/AOT alias table must not scalarize enum cases

Done when (php-src-strict)

• Repro prints enum object + bool(true) for identity.
• class_alias_enum.phpt and class_alias_enum_jit.phpt green.
• class_alias_enum_case_typeerror.phpt still TypeErrors on case-as-operand (closed Stdlib: class_alias() — enum case alias operand must TypeError not LogicException (basic_functions.c) #6583 behavior).

Related

#5765 (closed), #6583 (closed), #9152 (is_a on enums).

[PurHur]

claim: cursor-agent-lane-c — starting this run (enum class_alias compliance tail; case objects already green on VM — fixing stale class_exists EXPECT in class_alias_enum.phpt per Zend PHP 8.2+)

[PurHur]

Merged via #10714

Verification

• ./vendor/bin/phpunit --filter class_alias_enum — OK (3 tests)
• Repro: EAlias::A → enum(E::A), EAlias::A === E::A → true

Fix: Updated stale class_alias_enum.phpt EXPECT — class_exists() on enum alias is true on Zend PHP 8.2+ (case fetch parity was already green on master).