Re: --with-included-foo={yes,no} and which foo.h to use?

[Aharon Robbins]

I finally found some time to catch up on reading this list.

> Date: Wed, 15 Jun 2005 02:31:02 -0400
> From: Charles Levert <address@hidden>
> Subject: Re: --with-included-foo={yes,no} and which foo.h to use?
> To: address@hidden
>
> For GNU grep's purposes, we need non-POSIX
> constants such as RE_ICASE, and I can see those
> in my "/usr/include/regex.h".  Assuming a system
> with a satisfactorily recent glibc, we can avoid
> code duplication (and have a smaller executable
> before dynamic linking) by using its regex code.

I take just the opposite approach with gawk.  I always use the regex.[ch]
that I ship, so that I'm guaranteed consistent behavior.  This is
particularly necessary if I know that I've fixed a bug that will take
a while to propogate to released distributions, and it's also necessary
for the non-glibc systems out there.

IMHO you could be asking for trouble if the same situation arises. I
recommend:

(a) upgrading to the glibc regex
(b) always using the included regex

If the distribution vendors want to optimize that out, let them; it's
not the responsibility of the GNU developer to worry about that.

Now, why glibc regex?  First of all, it handles the i18n issues better
than the original one. Secondly, it handles backtracking regular
expressions better than the original one.  Gawk has been using it for
a while now, and there's no way I'd switch back.

My two cents worth,

Arnold