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

[Carlo Arenas <carenas@gmail.com>]

On Mon, Aug 19, 2019 at 3:23 PM Junio C Hamano <gitster@pobox.com> wrote:
>
> There may be others I am missing.

should we still support PCRE1? I think in this case the problem is
compounded by the fact that unless we do something like [1], the real
fix for those UTF-8 validation issues will require a yet unreleased
version of PCRE2 and will never be available for PCRE1, making the
user experience suboptimal.

and explained in [1] there was a series to cleanup (both for
maintainability and to mitigate regressions) the PCRE1 code that is
yet to be formally reviewed in [2]

there is also the question of if we should provide knobs so users can
"tune" their pcre library to workaround some of the quirks or if we
should do more work ourselves to handle those quirks and improve the
error reporting.

one example of that is as you pointed out JIT, but also applies to
other things like PCRE's stack size, or depending on our solution for
PCRE1, accepting the risk (which already exist anyway) to accept
problems with matching because of corrupted UTF-8 in the haystack

> Is ab/pcre-jit-fixes a good base to collectively work on to finish
> the topics floated around PCRE during the last cycle?

V3 of that (which was never sent) might be better IMHO, I had to also
admit I was surprised to see the whole no-kwset series this depended
on being dropped but would seem it was just partially merged with
pcre-jit-fixes (which is missing the patches that address the UTF-8
issues with PCRE2's unreleased flag and that should be part of that
V3)

it might be worth also rebasing pcre2-chartables-leakfix on top of
this to avoid conflicts, eventhough I had to admit that I was
expanding on integrating [3], to avoid having to squash a fix into
René's patch (as he suggested) and that would be part of a reroll from
that series.

Carlo

[1] https://public-inbox.org/git/CAPUEspgStVxL=0SoAg82vxRMRGLSEKdHrT-xq6nCW1sNq7nLsw@mail.gmail.com/
[2] https://public-inbox.org/git/20190726202642.7986-1-carenas@gmail.com/
[3] https://public-inbox.org/git/20190721194052.15440-1-carenas@gmail.com/