Subject: bug#51484: closed (Re: bug#51484: [PATCH] Move runtime check for recent giflib to compile time)

From: [email-masked] (GNU bug Tracking System)
Date: Fri, 29 Oct 2021 18:16:02 +0000

Your bug report

#51484: [PATCH] Move runtime check for recent giflib to compile time

which was filed against the emacs package, has been closed.

The explanation is attached below, along with your original report.
If you require more details, please reply to [email-masked].

-- 
51484: http://debbugs.gnu.org/cgi/bugreport.cgi?bug=51484
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Subject: Re: bug#51484: [PATCH] Move runtime check for recent giflib to compile time
From: Stefan Kangas <[email-masked]>
To: Eli Zaretskii <[email-masked]>
Cc: [email-masked]
Date: Fri, 29 Oct 2021 11:15:04 -0700
List-Id: <debbugs-submit.debbugs.gnu.org>

Eli Zaretskii <[email-masked]> writes:

> I generally prefer to avoid #ifdef's, so I think the change you
> propose is not for the better.  We have similar code elsewhere in
> Emacs, and there's nothing wrong with it.

OK, thanks for taking a look.  I appreciate you taking the time to
explain your thinking as well, it is most helpful.

I'm closing this bug report.

Subject: [PATCH] Move runtime check for recent giflib to compile time
From: Stefan Kangas <[email-masked]>
To: [email-masked]
Date: Fri, 29 Oct 2021 07:42:56 -0700
List-Id: <debbugs-submit.debbugs.gnu.org>

Severity: wishlist

I'm looking into some bugs in how we handle gifs, and I see that we
check for GIFLIB_MAJOR at runtime.  Is there any reason not to do it at
compile-time as in the attached patch?

I expect that GCC is smart enough to see that "5 < 4" is always false
and optimize this all away, and probably also won't include unused
static variables, so maybe this doesn't matter.  But I think it's nice
to be a bit more explicit, and I guess it can't hurt to see warnings if
anyone tries using interlace_start and interlace_increment outside of
their intended use.