bug#47518: 28.0.50; gcc 5.5.0 -Wstrict-overflow warning in INT_ADD_WRAPV

[Lars Ingebrigtsen]

David Fussner <dfussner@googlemail.com> writes:

> Since late December, when compiling master with gcc 5.5.0 on a 32-bit
> Slackware install I see multiple warnings like the following.  _All_
> of the messages involve INT_ADD_WRAPV:
>
> In file included from dispnew.c:27:0:
> lisp.h: In function 'modiff_incr':
> lisp.h:3505:3: warning: assuming signed overflow does not occur when
> assuming that (X + c) > X is always true [-Wstrict-overflow]
>    bool modiff_overflow = INT_ADD_WRAPV (a0, 1, a);
>    ^
> (This last from every .c file that includes lisp.h.)

It's to be expected to get warnings in older gcc versions for a variety
of things -- and gcc 5.5.0 is five years old.  We don't have a strict
policy for this in Emacs, but it's been common to disregard warnings
from gcc versions that are a few years old.

So I'm closing this bug report.  If somebody thinks that this is
something that should be worked on, please respond to the debbugs
address and we'll reopen.

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no