Subject: Re: [PATCH 2/3] grep: stop "using" a custom JIT stack with PCRE v2

From: Ævar Arnfjörð Bjarmason <[email-masked]>
Date: Wed, 24 Jul 2019 22:06:09 +0200

On Wed, Jul 24 2019, Junio C Hamano wrote:

> Ævar Arnfjörð Bjarmason  <[email-masked]> writes:
>
>> Since we've haven't had any reports of users running into
>> PCRE2_ERROR_JIT_STACKLIMIT in the wild I think we can safely assume
>> that we can just use the library defaults instead and drop this
>> code.
>
> Does everybody use pcre2 with JIT with Git these days, or only those
> who want to live near the bleeding edge?

My informal survey of various package recipies suggests that all the big
*nix distros are using it by default now, so we have a lot of users in
the wild, including in the just-released Debian stable.

So I'm confidend that if there were issues with e.g. it dying on
patterns in practical use we'd have heard about them.

>> This won't change with the wider use of PCRE v2 in
>> ed0479ce3d ("Merge branch 'ab/no-kwset' into next", 2019-07-15), a
>> fixed string search is not a "large or complicated pattern".
>
> In any case, if we were not "using" the custom stack anyway for v2,
> this change does not hurt anybody, possibly other than those who
> will learn about pcre2 support by reading this message and experiments
> with larger patterns.  And it should be simple to wire it back if it
> becomes necessary later.

*nod*