Re: [PATCH] grep: under --debug, show whether PCRE JIT is enabled

From: Carlo Arenas <carenas@gmail.com>
To: Junio C Hamano <gitster@pobox.com>
Cc: "Johannes Schindelin" <Johannes.Schindelin@gmx.de>,
	"Beat Bolli" <dev+git@drbeat.li>,
	"Ævar Arnfjörð Bjarmason" <avarab@gmail.com>,
	git@vger.kernel.org
Subject: Re: [PATCH] grep: under --debug, show whether PCRE JIT is enabled
Date: Mon, 26 Aug 2019 09:36:38 -0700	[thread overview]
Message-ID: <CAPUEspj4BJLjXorUXMiZnFtNcmhym_2QL5GUqeaGaCoxk=zjtw@mail.gmail.com> (raw)
In-Reply-To: <xmqqftlnkj98.fsf@gitster-ct.c.googlers.com>

On Mon, Aug 26, 2019 at 9:02 AM Junio C Hamano <gitster@pobox.com> wrote:
>
> Carlo Arenas <carenas@gmail.com> writes:
>
> > ... but
> > ab/pcre-jit-fixes and UTF-8 validation are likely to make that more
> > difficult (even if it is a mostly self inflicted wound AFAIK)
>
> Hmm, in what way?  Do you mean that we'd be invested even more in
> pcre1 in an effort to keep supporting, that the sunk cost would
> dissuade us from deprecating the support even more, or something?

on the contrary, PCRE1 works fine but our recent changes make it worst
unnecessarily (IMHO)

 for example 685668faaa (grep: stop using a custom JIT stack with PCRE
v1, 2019-07-26) adds 2 regressions as discussed in [1]

* git grep -P will now throw an error if there are non UTF-8 documents
in the haystack (even if JIT is available)
* git grep -P '^([/](?!/)|[^/])*~/.*' will now fail with a cryptic
PCRE error instead of succeeding (but at least will be consistent and
show the same error with PCRE2)

Carlo

[1] https://public-inbox.org/git/CAPUEspgStVxL=0SoAg82vxRMRGLSEKdHrT-xq6nCW1sNq7nLsw@mail.gmail.com/