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In-Reply-To: <DM5PR07MB3067B328F87C890DDDAA3552F9040@DM5PR07MB3067.namprd07.prod.outlook.com>
Date: Thu, 30 Jan 2020 13:47:45 +0100
Message-ID: <CAG9XoMQ_PLQwSdi87Z5rFBMFtPw9SdQrA3gwHF8so2UbGW-VjA@mail.gmail.com>
To: tyson andre <tysonandre775@hotmail.com>
Cc: "bishop@php.net" <bishop@php.net>, PHP Internals <internals@lists.php.net>
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Subject: Re: [PHP-DEV] How to debug a segmentation fault?
From: benjamin.morel@gmail.com (Benjamin Morel)

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>
> Infinite recursion leading to a segfault is **a known bug with no plans t=
o
> be fixed that I know of,** which I've encountered many times.


That's unfortunate; as I said in the bug report, it's so easy to trigger
and so easy to miss when reviewing the code! And the process crashing
instead of reporting an error is really a pity.
An explicit error message would be nice, but as I understand this would
require setting a hard limit on the call stack depth, which may bring other
issues.

Thank you,
=E2=80=94 Benjamin

On Thu, 30 Jan 2020 at 03:59, tyson andre <tysonandre775@hotmail.com> wrote=
:

> > Sorry, I didn't notice that https://bugs.php.net/bug.php?id=3D79194 was
> already [solved and] closed with a similar answer.
>
> In addition to phpspy, a tool I forgot to mention was Phan. (
> https://github.com/phan/phan)
>
> `phan --redundant-condition-detection` will enable many of Phan's checks,
> including code that looks like a function or method calling itself
> unconditionally, or with the same args.
> I got the idea for adding a check for PhanInfiniteRecursion
> (and PhanPossiblyInfiniteRecursionSameParams) after investigating a simil=
ar
> segfault over a year ago ago
> (and considering most of those solutions),
> to detect that type of bug before it ran.
>
> https://github.com/phan/phan/blob/master/internal/Issue-Types-Caught-by-P=
han.md#phaninfiniterecursion
> has an example of what it detects

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