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

[Hans de Goede]

Hi,

On 03/05/2014 01:13 AM, Alan Coopersmith wrote:
> On 03/ 4/14 08:54 AM, Hans de Goede wrote:
>> Hi Daniel,
>>
>> On 03/03/2014 03:14 PM, Daniel Stone wrote:
>>> Hi,
>>>
>>> On 3 March 2014 07:56, Hans de Goede <hdegoede at redhat.com> wrote:
>>>> The latest glibc considers _BSD_SOURCE deprecated, leading to the following
>>>> warning being issued for pretty much every C-file in the xserver:
>>>>
>>>> In file included from /usr/include/stdint.h:25:0,
>>>>                   from
>>>> /usr/lib/gcc/x86_64-redhat-linux/4.8.2/include/stdint.h:9,
>>>>                   from ../include/misc.h:81,
>>>>                   from miexpose.c:82:
>>>> /usr/include/features.h:145:3: warning: #warning "_BSD_SOURCE and
>>>> _SVID_SOURCE are deprecated, use _DEFAULT_SOURCE" [-Wcpp]
>>>>   # warning "_BSD_SOURCE and _SVID_SOURCE are deprecated, use _DEFAULT_SOURCE"
>>>>     ^
>>>>
>>>> This silences up these warnings by switching to _GNU_SOURCE, which also
>>>> includes all the necessary functions from BSD.
>>>
>>> AC_USE_SYSTEM_EXTENSIONS is better than hardcoded _*_SOURCE. The
>>> latter is often reductive (e.g. can mean 'only expose me the
>>> functionality from this platform', rather than 'add extensions from
>>> this platform'), so the autoconf macro will do the right thing.
>>
>> Hmm, I took the GLIBC test for using _GNU_SOURCE from configure.ac from the
>> xserver itself,
>> if we move to AC_USE_SYSTEM_EXTENSIONS we should probably do this in the xserver's
>> configure.ac and completely drop the -D_BSD_SOURCE from the xtrans.pc file, does
>> that sound like a plan ?
> 
> The X server already has AC_USE_SYSTEM_EXTENSIONS in configure.ac, it just we
> never cleaned up/dropped the older _GNU_SOURCE check.
> 
> The one advantage to doing it in libxtrans is that it can provide a common
> setting across all xtrans consumers, if the setting is needed in all of them.

Beginner question: Are the more consumers of xtrans then just the xserver ?

Regards,

Hans