Language: class constant new expression — compile rejects valid PHP 8.3+ (Zend/zend_compile.c)

Problem

PHP 8.3+ allows new expressions in class constant initializers (e.g. public const X = new C(1);). This compiler rejects them at compile time with New expressions are not supported in this context, blocking PHP 8.3/8.4 parity and self-host code using immutable constant object graphs.

Mentioned in parity snapshot #9978 but lacks a dedicated claimable issue.

php-src reference

php/php-src Zend/zend_compile.c — zend_compile_const_expr(), ZEND_AST_NEW in constant context (PHP 8.3+)
php/php-src Zend/zend_constants.c — object-typed class constants, serialization at compile time
RFC: New in initializers

Repro (verified 2026-06-20)

test/repro/maintainer_gap_new_in_constant.php:

<?php
class C {
    public function __construct(public int $n = 0) {}
}
class Holder {
    public const X = new C(1);
}
var_dump(Holder::X->n);

./script/docker-exec.sh -- bash -lc 'source script/php-env.sh
php bin/vm.php test/repro/maintainer_gap_new_in_constant.php 2>&1 | head -3
'

Runtime	Result
Zend PHP 8.3+	`int(1)`
`php bin/vm.php`	`parseAndCompile failure: New expressions are not supported in this context` ❌

Scope (PHP-in-PHP first)

Area	Files
Parser/CFG	`lib/Parser.php`, constant-expression allowlist
Compiler	`lib/Compiler.php` — lower `new` in `zend_compile_const_expr` path
VM	constant materialization for object constants
JIT	`lib/JIT/ClassConstFetchHelper.php` if object constants need runtime box

Done when

Repro compiles and prints int(1) on VM (php-src-strict)
Holder::X is the same object identity across reads (Zend constant object semantics)
Negative: new in non-constant contexts unchanged
test/compliance/cases/language/class_const_new_expression.phpt guards regression
JIT/AOT agree with VM when both in scope

Links

North star Epic: Self-host critical path — compiler compiles itself (M3→M5) #1492 · Snapshot Parity backlog snapshot 2026-06-19 (b) — class const new, enum static default, highlight regressions (refs #1492) #9978

claim: worker-lane-B — starting this run

Allow `new` expressions in class constant initializers (#10198). (#10206

Merged via #10206.

Fix: Removed stale compile-time rejection of new in class constant initializers (NewWithoutParensCompileCheck); enabled CompilerVersion::supportsClassConstObjectExpressions() for PHP 8.3+ target. Existing VM/JIT materialization (finalizePendingNewClassConst, ClassConstMaterializer) handles object constants with shared identity.

Verification:

./script/docker-exec.sh -- bash -lc 'source script/php-env.sh && php bin/vm.php test/repro/maintainer_gap_new_in_constant.php'
# int(1)

./script/docker-exec.sh -- bash -lc 'source script/php-env.sh && ./vendor/bin/phpunit test/compliance/VMTest.php --filter "class_const_new|class_const_object|const_expr_new|new_in_constant"'
# OK (9 tests)

./script/docker-exec.sh -- bash -lc 'source script/php-env.sh && ./vendor/bin/phpunit test/compliance/JITTest.php --filter "class_const_object"'
# OK (2 tests)

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Language: class constant `new` expression — compile rejects valid PHP 8.3+ (Zend/zend_compile.c) #10198

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php-src reference

Repro (verified 2026-06-20)

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Language: class constant new expression — compile rejects valid PHP 8.3+ (Zend/zend_compile.c) #10198

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Problem

php-src reference

Repro (verified 2026-06-20)

Scope (PHP-in-PHP first)

Done when

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PurHur commented on Jun 20, 2026

PurHur commented on Jun 20, 2026

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Language: class constant `new` expression — compile rejects valid PHP 8.3+ (Zend/zend_compile.c) #10198