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Re: [PATCH 1/2] grep: make sure NO_LIBPCRE1_JIT disable JIT in PCRE1

From
Carlo Arenas <carenas@gmail.com>
Date
Aug 27, 2019, 01:34 UTC
Message-ID
<CAPUEspjnwbC8L+9Ni_PN5kzROh3cqxEQRrhZHG_dhiR-K25OJA@mail.gmail.com>
In-Reply-To
<xmqq36hnhi4n.fsf@gitster-ct.c.googlers.com>
On Mon, Aug 26, 2019 at 11:54 AM Junio C Hamano <gitster@pobox.com> wrote:
Show 11 quoted lines
>
> Carlo Marcelo Arenas Belón  <carenas@gmail.com> writes:
>
> > e87de7cab4 ("grep: un-break building with PCRE < 8.32", 2017-05-25)
> > added a restriction for JIT support that is no longer needed after
> > pcre_jit_exec() calls were removed.
>
> I was initially puzzled by this statement, until I realized that the
> removal of pcre_jit_exec() happens in the topic still in flight that
> this patch builds on top of, namely 685668fa ("grep: stop using a
> custom JIT stack with PCRE v1", 2019-07-26).

sorry about that, I thought I had mentioned it in the cover letter (since the hash is likely to change and so is not fit for a commit message) but it is not there either.

how could this be tracked more effectively?
> So the logic is that because we do no longer call pcre_jit_exec()
> that weren't available between 8.20 and 8.32, these slightly older
> versions can now do JIT just like the ones post 8.32?

exactly; but also because it is no longer using the JIT fast path which skipped UTF-8 validation, will need a way to disable that or risk a regression as I mentioned in [1]

was planning in proposing a fix for PCRE1 based on [2] but wasn't sure if it could be part of this series, an independent one that is also based on ab/pcre-jit-fixes, and like this one, is mostly a consequence of 685668fa ("grep: stop using a custom JIT stack with PCRE v1", 2019-07-26) or something else, specially considering that Ævar dismissed it as a non issue in his commit message.

Carlo

[1] https://public-inbox.org/git/CAPUEspj4BJLjXorUXMiZnFtNcmhym_2QL5GUqeaGaCoxk=zjtw@mail.gmail.com/T/#m6acc8f68c398951457da469530bafa7e18811366 [2] https://public-inbox.org/git/20190721183115.14985-1-carenas@gmail.com/

Previous: Junio C Hamano
Message 6 of 6 in “PCRE1 cleanup”
  1. 0/2 PCRE1 cleanupCarlo Marcelo Arenas Belón, Aug 25, 2019
  2. 2/2 grep: refactor and simplify PCRE1 supportCarlo Marcelo Arenas Belón, Aug 25, 2019
  3. Junio C HamanoAug 26, 2019
  4. 1/2 grep: make sure NO_LIBPCRE1_JIT disable JIT in PCRE1Carlo Marcelo Arenas Belón, Aug 25, 2019
  5. Junio C HamanoAug 26, 2019
  6. Carlo ArenasAug 27, 2019

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