Follow @Openwall on Twitter for new release announcements and other news
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date: Tue, 4 Oct 2016 13:39:26 -0400
From: Rich Felker <>
To: Johannes Schindelin <>
Cc: Jeff King <>,,
Subject: Re: Re: Regression: git no longer works with musl libc's
 regex impl

On Tue, Oct 04, 2016 at 06:08:33PM +0200, Johannes Schindelin wrote:
> Hi Rich,
> On Tue, 4 Oct 2016, Rich Felker wrote:
> > On Tue, Oct 04, 2016 at 11:27:22AM -0400, Jeff King wrote:
> > > On Tue, Oct 04, 2016 at 11:08:48AM -0400, Rich Felker wrote:
> > > 
> > > > 1. is nonzero mod page size, it just works; the remainder of the last
> > > >    page reads as zero bytes when mmapped.
> > > 
> > > Is that a portable assumption?
> > 
> > Yes.
> No, it is not. You quote POSIX, but the matter of the fact is that we use
> a subset of POSIX in order to be able to keep things running on Windows.
> And quite honestly, there are lots of reasons to keep things running on
> Windows, and even to favor Windows support over musl support. Over four
> million reasons: the Git for Windows users.
> So rather than getting into an ideological discussion about "broken"
> systems, it would be good to keep things practical, realizing that those
> users make up a very real chunk of all of Git's users.
> As to making NO_REGEX conditional on REG_STARTEND: you are talking about
> apples and oranges here. NO_REGEX is a Makefile flag, while REG_STARTEND
> is a C preprocessor macro.

It seems like you could just always compile the source file, and just
have it all inside #if defined(NO_REGEX) || !defined(REG_STARTEND) or

> And lastly, the best alternative would be to teach musl about
> REG_STARTEND, as it is rather useful a feature.

Maybe, but it seems fundamentally costly to support -- it's extra
state in the inner loops that imposes costly spill/reload on archs
with too few registers (x86). I'll look at doing this when we
overhaul/replace the regex implementation, and I'm happy to do some
performance-regression tests for adding it now if someone has a simple
patch (as was mentioned on the musl list).


Powered by blists - more mailing lists

Confused about mailing lists and their use? Read about mailing lists on Wikipedia and check out these guidelines on proper formatting of your messages.