[PATCH libxtrans] configure: under glibc define _GNU_SOURCE rather then _BSD_SOURCE

[Mark Kettenis]

> Date: Sat, 08 Mar 2014 17:11:42 +0100
> From: Hans de Goede <hdegoede at redhat.com>
> 
> Hi,
> 
> On 03/08/2014 05:07 PM, Gaetan Nadon wrote:
> > On 14-03-08 09:03 AM, Hans de Goede wrote:
> >> So I've just been looking into using AC_USE_SYSTEM_EXTENSIONS but that seem pretty
> >> useless, it only adds the relevant defines to confdefs.h, not into cflags,
> >> and in libxtrans we want to add them to the .pc file, so we need them in a variable.
> >>
> >> I'm open to different suggestions, but I think my initial patch might be the best
> >> way to fix this.
> >>
> > Check the pattern in other modules such as libX11. The source code includes the content of the generated config.h (see config.h.in).
> 
> That won't work for libxtrans, as that provides .c files to be included by other
> projects (a shared copylib if you want). So there is no config.h, since
> that would conflict with the config.h from the code including the xtrans
> .c files.
> 
> Hence traditionally xtrans.pc had a -D_BSD_SOURCE in its CFLAGS, but that is
> causing a ton of warnings when building with the latest glibc.

Perhaps you should push this back to te glibc developers, pointing out
that their change makes it hard to write portable software, pointing
out that _BSD_SOURCE is a widely used as a way to make available
certain BSD extensions.  If they really want to deprecate this
functionality, perhaps they can be convinced not to emit the warning
if both _GNU_SOURCE and _BSD_SOURCE are defined.  Then you could have
the .pc file simply contain -D_GNU_SOURCE -D_BSD_SOURCE.