Regression: enum relational operators — < and <=> order inverted vs Zend (re-#9016, zend_enum.c)

[PurHur]

Category

language · php-src-strict · regression

Problem

Relational comparison between two cases of the same backed enum (<, <=>) must follow php-src declaration order. #9016 was closed 2026-06-16 but the repro still fails on VM (2026-06-17 audit): ordering is inverted for both int- and string-backed enums.

php-src reference

• php/php-src Zend/zend_enum.c — zend_compare_enum, case ordering
• php/php-src Zend/zend_operators.c — relational ops on enum objects

Repro

test/repro/issue_enum_relational_operators.php (in tree):

<?php
declare(strict_types=1);
enum E: int { case A = 1; case B = 2; }
enum S: string { case X = 'a'; case Y = 'b'; }
var_dump(E::A < E::B);
var_dump(E::A <=> E::B);
var_dump(S::X < S::Y);
var_dump(S::X <=> S::Y);

./script/docker-exec.sh -- bash -lc 'source script/php-env.sh
php test/repro/issue_enum_relational_operators.php
php bin/vm.php test/repro/issue_enum_relational_operators.php
'

Expr	Zend PHP 8.2	VM today
E::A < E::B	bool(false)	bool(true)
E::A <=> E::B	int(1)	int(-1)
S::X < S::Y	bool(false)	bool(true)
S::X <=> S::Y	int(1)	int(-1)

Scope (this repo)

Path	Work
lib/VM/EnumCaseSupport.php	compareSpaceship() / relational lowering must match Zend ordinal, not inverted backing compare
lib/VM/Variable.php	enum case </> paths
lib/JIT/	JIT/AOT spaceship/relational ops must agree with VM
test/compliance/cases/language/enum_relational_operators.phpt	guard repro

PHP-in-PHP — no new runtime/*.c logic.

Done when

• Repro matches Zend under VM (and JIT if enum compares are lowered)
• Compliance PHPT green in Docker
• Closes regression vs Language: enum case relational operators < and <=> — wrong order vs Zend (zend_enum.c) #9016 / Language: backed enum relational operators (<, <=, >=, >, <=>) compare backing scalars not object order (zend_enum.c) #8897

Related

• Epic: Self-host critical path — compiler compiles itself (M3→M5) #1492 · Language: enum case relational operators < and <=> — wrong order vs Zend (zend_enum.c) #9016 (closed, still red) · Language: enum case identity comparison — == / === / <=> must not coerce backing scalars (Zend/zend_enum.c) #9009 (identity compare)

[PurHur]

claim: cursor-agent-lane-b — starting this run

[PurHur]

Verified on master (2026-06-17): repro and enum_relational_operators.phpt already match Zend in Docker — E::A < E::B → false, E::A <=> E::B → 1. Unclaiming; no code change needed.

[PurHur]

Verified green on master 2026-06-18 (worker-lane-a audit). No code change needed — see #1492 north-star queue hygiene.