From: Carlo Arenas Date: Tue, 27 Aug 2019 01:34:42 GMT Subject: Re: [PATCH 1/2] grep: make sure NO_LIBPCRE1_JIT disable JIT in PCRE1 Message-ID: In-Reply-To: On Mon, Aug 26, 2019 at 11:54 AM Junio C Hamano wrote: > > Carlo Marcelo Arenas Belón 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/