Subject: Re: bug#24159: [PATCH] dfa: minor fix for whether dfa is fast or not

From: Norihiro Tanaka <[email-masked]>
Date: Sat, 06 Aug 2016 11:32:46 +0900

On Fri, 5 Aug 2016 13:29:43 -0700
Jim Meyering <[email-masked]> wrote:

> On Fri, Aug 5, 2016 at 4:30 AM, Norihiro Tanaka <[email-masked]> wrote:
> > dfaoptimize() is not set fast flag even if it is success, but it is wrong.
> > If success, dfa matcher uses algorithm for single byte, and it is so fast.
> >
> > I think this bug does not affect for grep, but it will affect with the
> > patch that I just sent to gawk.
> 
> Thank you for the patch.
> I was going to push it with the attached slightly updated log message.
> Note however that grep does use that -> fast member via dfasearch.c's
> use of the dfaisfast function.
> But then I realized I should at least verify with "make check", and
> found that this makes grep's dfa-match test fail.
> Thus, I will not be pushing it as-is.

Thanks for review and adjustment.  I re-ran all tests including dfa-match,
and they were passwd again in my machine.  Next, I will re-run them on
Fedora24, as my machine is RHEL 6.8 and GCC 4.4.7 which is too old.

However, I do not know why dfa-match test fails on your machine.
dfa-match test does not use grep.  It directly calls dfa functions through
dfa-match-aux executable in order to test codes of dfa which grep does
not use.  dfa-match-aux does not referer to the ->fast member.