PHP 8.4 min function fails on typed integer #14873
Description
Description
Hello,
The min() function seems to fail (returns null) on a typed integer, but only in specific situations and environments.
Notes:
- It fails when called from Apache module
php84-apache2(i.e. from a Web browser) but not when called from CLI (command line). - It fails with a typed
intparameter (function testMin(int $value)) but not on untyped parameter (function testMin($value)).
The following code:
<?php
function testMin(int $value): int {
$value = min($value, 100);
return $value;
}
echo testMin(5);Resulted in this output:
PHP Fatal error: Uncaught TypeError: testMin(): Return value must be of type int, null returned in ./test-min.php:5
Stack trace:
#0 ./test-min.php(8): testMin()
#1 {main}
thrown in ./test-min.php on line 5
But I expected this output instead:
5
System information:
# cat /etc/issue
Welcome to Alpine Linux 3.21.0_alpha20240606 (edge)
Kernel \r on an \m (\l)
# php -v
PHP 8.4.0alpha1 (cli) (built: Jul 4 2024 10:02:18) (NTS)
Copyright (c) The PHP Group
Zend Engine v4.4.0-dev, Copyright (c) Zend Technologies
with Zend OPcache v8.4.0alpha1, Copyright (c), by Zend TechnologiesPHP Version
PHP 8.4.0alpha1
Operating System
Alpine Linux 3.21.0_alpha20240606 (edge)
Activity
Initial support for PHP 8.4
ndossche commentedon Jul 8, 2024
Also reproduces in CLI webserver. I'll take a look... I think this is related to frameless function calls.
EDIT: only reproduces with opcache on
EDIT2: gets broken by the DFA optimizer pass somehow
ndossche commentedon Jul 8, 2024
The problem is that this line in the VM:
ZVAL_NULL(result);changes the type ofarg1as well, because after the DFA pass the result and input both use CV0($result).ndossche commentedon Jul 8, 2024
I attempted a fix in #14876, but got stuck on the JIT which fails on arm64 with "stack smashing detected". And I don't feel like digging into it more. The VM part of my patch works fine, it's just the JIT stuff that needs more work. Someone else can pick up where I left off with my PR.
Alkarex commentedon Jul 9, 2024
Note: for some reason, the
max()function does not seem affectedInitial support for PHP 8.4 (#6615)
ndossche commentedon Jul 10, 2024
It seems like working around this in the optimizer is as simple as changing
opline_supports_assign_contractionon first sight. Let me try...Fix phpGH-14873: PHP 8.4 min function fails on typed integer
Fix phpGH-14873: PHP 8.4 min function fails on typed integer
Re-enable OPCache for PHP 8.4-alpha2
Re-enable OPCache for PHP 8.4-alpha2 (#6637)