g++ cross distro compilation problem

[Jonathan Wakely]

On 20 January 2011 19:57, Jonathan Wakely <jwakely.gcc@gmail.com> wrote:
> On 20 January 2011 19:28, Nick Stokes wrote:
>>
>> Great! This indeed revealed it.  In /usr/include/locale.h (same
>> location, line  133, in both distros actually)  there is #ifdef
>> __USE_GNU  on CentOS version, which is  #ifdef __USE_XOPEN2K8 in
>> SUSE's version.   So, in fact if I define `__USE_XOPEN2K8'  while
>> compiling on SUSE, it works. Hmm, go figure.. This can not be the
>> right way to do this. What am I missing?
>
> I don't know why they're different (on my glibc 2.12 system the
> uselocale definition is guarded by __USE_GNU, just like your CentOS
> system) but it looks like you've found the solution.
>
> Users are not supposed to use the __USE_XXX macros, instead you should
> define _GNU_SOURCE to enable __USE_GNU and _POSIX_C_SOURCE=200809L (or
> greater) to enable __USE_XOPEN2K8.

It looks as though you can also define _XOPEN_SOURCE=700 (or greater)
to set __USE_XOPEN2K8

Either way, you should use one of those standard feature test macros,
not the __USE_XOPEN2K8 one which is an internal implementation
details, see man feature_test_macros for more details.