Language: parenthesized DNF intersection-only types compile on VM — Zend 8.2 reference profile parse error (Zend/zend_compile.c)

[PurHur]

Summary

Parenthesized intersection-only DNF types such as (I1&I2) $param and function f(): (I1&I2) are accepted and executed on this compiler. The project’s Zend 8.2.31 docker reference rejects them at parse time (unexpected variable "$o", expecting "|").

PHP 8.3+ php-src allows these forms; PHP 8.2 does not. Today lib/Ast/DnfParenTypeRewriter.php unwraps them for php-parser 4.x compatibility (#9733) without gating on language profile.

php-src reference

• Zend/zend_compile.c — zend_compile_type() / DNF normalization (PHP 8.3+ parenthesized intersection leaves)
• Compare lib/ExitFunctionSyntaxRejector.php — precedent for rejecting 8.4-only syntax on 8.2 profile

PHP implementation target

• lib/Ast/DnfParenTypeRewriter.php — gate unwrap behind language version / reference profile, or
• lib/Compiler.php + lib/VM/DnfCheck.php / lib/JIT/DnfParamCheck.php — enforce runtime DNF constraints only when syntax is legal for active profile
• Do not regress unparenthesized I1&I2 $param (valid on 8.2)

Repro

./script/docker-exec.sh -- php bin/vm.php test/repro/maintainer_gap_dnf_paren_intersection_param.php
# Zend 8.2: parse error
# VM: ok

./script/docker-exec.sh -- php bin/vm.php test/repro/maintainer_gap_dnf_paren_intersection_return.php
# Zend 8.2: parse error
# VM: true

Done when (php-src-strict)

• On Zend 8.2 reference profile (current docker): (I1&I2) $param and function f(): (I1&I2) are compile-time parse errors matching Zend output class
• When profile bumped to 8.3+: same snippets compile and instanceof/return checks succeed
• Compliance guards for both profiles (or explicit phpc.json language version) under test/compliance/cases/language/

Notes

• If the project intentionally targets 8.3+ syntax ahead of docker reference, document in issue fix + docs/capabilities.md and add profile gate flag — default CI must stay php-src-strict on 8.2 docker.

[PurHur]

claim: Worker lane A — batch (issues #14904)

[PurHur]

Merged via #14916.

Verification

• ./script/docker-exec.sh -- php bin/vm.php test/repro/maintainer_gap_dnf_paren_intersection_param.php → exit 255, unexpected variable "$o", expecting "|" line 6 (matches Zend 8.2)
• ./script/docker-exec.sh -- php bin/vm.php test/repro/maintainer_gap_dnf_paren_intersection_return.php → exit 255, unexpected token "{", expecting "|" line 6
• ./script/docker-exec.sh -- vendor/bin/phpunit test/unit/DnfParenIntersectionReferenceProfileTest.php --filter dnf_paren → green