Stdlib: class_constants() — class/interface/enum constant map missing (ext/standard/basic_functions.c)

[PurHur]

Category

stdlib

Problem

PHP exposes class_constants(string $class): array returning an associative map of class/interface/enum constants (names → values). This compiler has constant("Class::NAME"), ReflectionClassConstant, and enum cases(), but class_constants() is not registered — calls fail with Call to undefined function class_constants().

php-src reference

• php/php-src ext/standard/basic_functions.c — PHP_FUNCTION(class_constants)
• php/php-src Zend/zend_constants.c — class constant table iteration

Repro (failure today)

<?php
interface I { const X = 1; }
enum E: string { case A = 'a'; case B = 'b'; }
var_export(class_constants('I'));
var_export(class_constants(E::class));

./script/docker-exec.sh -- bash -lc 'source script/php-env.sh
php bin/vm.php -r "var_dump(function_exists(\"class_constants\"));"
php repro.php
php repro.php  # Zend reference
'

Observed (VM): function_exists('class_constants') → false; repro fatal.

Expected (Zend): array('X' => 1) and enum case name → case object map.

Implementation hints (PHP-in-PHP)

• Handler in ext/standard/class_constants.php backed by existing compiler class/enum metadata (mirror constant() resolution in ext/standard/constant.php).
• Register in ext/standard/Module.php; VM via reflection/class tables in lib/VM.php / lib/Compiler/.
• JIT/AOT: lower from compile-time class tables where possible; otherwise VM builtin.
• Compliance: test/compliance/cases/stdlib/class_constants*.phpt (class, interface, enum, not-found TypeError).

php-src-strict

• Invalid class name → Error/TypeError matching Zend.
• Enum returns case objects, not backing scalars.

Pairs

• Stdlib: ReflectionClass::getConstants()/getConstant() — methods not registered on VM (php_reflection.c, blocks #4479) #6950 (ReflectionClass::getConstants() registration)
• Stdlib: ReflectionClassConstant — visibility, value, and attributes parity (ext/reflection/php_reflection.c) #4386 (ReflectionClassConstant parity)

[PurHur]

claim: PHP Compiler STD Lib — starting this run

[PurHur]

Merged via #7326

Verification (Docker harness):

• vendor/bin/phpunit test/unit/ClassConstantsBuiltinTest.php — OK
• vendor/bin/phpunit --filter class_constants test/compliance/VMTest.php — OK (incl. errors phpt)
• vendor/bin/phpunit --filter class_constants test/compliance/JITTest.php — OK
• php bin/compile.php -l on AOT fixture body — exit 0

Note: bin/compile.php -o AOT link currently segfaults (exit 139) for all fixtures on this host (including pre-existing class_parents_get_class_vars); not specific to this change. VM + JIT + AOT lint gates green.