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Language: comparison inside function call argument — var_dump($x !== false) binds as (var_dump($x)) !== false (Zend/zend_compile.c) #13694
Description
Category
language · php-src-strict
Problem
Comparison expressions passed as function call arguments parse with wrong precedence on VM: var_dump($x !== false) is compiled as (var_dump($x)) !== false instead of var_dump(($x !== false)).
Symptoms include false negatives in var_export($di !== false) while the same comparison in if ($di !== false) behaves correctly, and misleading maintainer repro output for otherwise-correct builtins.
php-src reference
Zend/zend_language_parser.y— argument expression is a fullexprZend/zend_compile.c—zend_compile_arg/ call argument list
Repro (verified 2026-06-29)
php -r 'var_dump(var_dump(1) !== false);' # Zend: int(1) bool(true)
php bin/vm.php -r 'var_dump(var_dump(1) !== false);' # VM: int(1) bool(false)
php test/repro/maintainer_gap_date_interval_plus_separator.php
php bin/vm.php test/repro/maintainer_gap_date_interval_plus_separator.phpMinimal:
$di = date_interval_create_from_date_string('1 day + 2 hours');
var_export($di !== false); // Zend: true; VM: false (mis-parse)
if ($di !== false) { echo $di->format('%d days %h hours'); } // both OKScope (PHP-in-PHP first)
| Layer | Path |
|---|---|
| Parser / AST | lib/Parser.php, lib/Compiler.php — call argument expression boundaries |
| VM emit | lib/VM.php — !== must not leak outside arg slot |
Done when (php-src-strict)
-
var_dump($expr !== false)dumps the boolean comparison result -
test/repro/maintainer_gap_date_interval_plus_separator.phpoutput matches Zend - No regression for assignment form
$r = $x !== false
Verification
php bin/vm.php -r 'var_dump(var_dump(1) !== false);'
php bin/vm.php test/repro/maintainer_gap_date_interval_plus_separator.php
Activity
PurHur commentedon Jun 29, 2026
claim: worker-lane-c — batch (issues #13694)
Fix comparison expression binding inside function call arguments (#13694
PurHur commentedon Jun 29, 2026
Merged via #13701
Verification
php bin/vm.php -r 'var_dump(var_dump(1) !== false);'→int(1)+bool(true)php bin/vm.php test/repro/maintainer_gap_date_interval_plus_separator.php→true+ formatted interval./vendor/bin/phpunit test/unit/InlineCallArgProducerSlotTest.php --filter testNotIdenticalInsideCallArgUsesComparisonSlot— OK./vendor/bin/phpunit test/compliance/VMTest.php --filter comparison_inside_call_arg— OK (Docker)Fix var_export($expr !== false, true) comparison arg wiring (#17250) (#…
chore: drop 24 more stale maintainer_gap repros (wave30 batch 2, #16660…