DatePeriod::__set_state() cannot handle null start

[chongwick]

Description

The following code:

<?php
$v_973 = '2022-07-16 12:00:00';
$v_974 = 'UTC';
$v_975 = new DateTimeZone($v_974,);
$v_976 = new DateTime($v_973,$v_975,);
$v_978 = null;
$v_980 = 'P2D';
$v_981 = new DateInterval($v_980,);
$v_983 = 2;
$v_985 = False;
$v_987 = True;
$v_966 = array('start' => $v_988,'end' => $v_976,'current' => $v_978,'interval' => $v_981,'recurrences' => $v_983,'include_start_date' => $v_985,'include_end_date' => $v_987,);
$v_988 = DatePeriod::__set_state($v_966,);
$v_989 = var_dump($v_988,);

Resulted in this output:

/home/w023dtc/nightly_php/php-src/Zend/zend_API.c:1794:6: runtime error: member access within null pointer of type 'zend_class_entry' (aka 'struct _zend_class_entry')
SUMMARY: UndefinedBehaviorSanitizer: undefined-behavior /home/w023dtc/nightly_php/php-src/Zend/zend_API.c:1794

PHP Version

nightly

Operating System

ubuntu 22.04

[chongwick]

@ndossche just wondering, but how do you feel about ai coding tools? Given a bug report like this, do you think it could diagnose/fix the root cause?

[ndossche]

I feel like the actual understanding of existig code of these tools is rather poor, and they more so try to target the symptom rather than the root cause. From the AI PRs or reports I've seen on this repo, almost none of them were right

[chongwick]

I'm either terrible at using coding assistants or if I'm being gaslit... This fuzzer is basically a PHP interpreter with a custom IR. I tried seeing what claude code could do with it, but it kept hallucinating AST node types/properties.

[ndossche]

Sounds familiar.
Is your fuzzer public btw? I do see https://github.com/chongwick/xphuzz .
I suppose you're working on a research paper?

[chongwick]

yes, my dissertation is on interpreter fuzzing.
xphuzz is an LLM-based fuzzer. kinda fun. kinda tricky. kinda expensive to run.
I call the ir-based one phuzzilli. I'd be happy to open-source it if you guys like.

[chongwick]

Is there a message board where I can mention this tool? The design is pretty interesting