Re: why is there no __MUSL__ macro?

["Jörg Krause" <jkrause@posteo.de>]

On 09/11/2014 02:38 PM, Szabolcs Nagy wrote:
> * J?rg Krause <jkrause@posteo.de> [2014-09-11 14:02:59 +0200]:
>> On 09/11/2014 01:17 PM, Szabolcs Nagy wrote:
>>> then _testing_ for conformance issues is the second try
>>> if the default fails
>> What do you mean with testing for concormance?
> eg glibc scanf uses "%a" for its own extension by default
> and c99 behaviour is only provided with appropriate cflags
>
> if your project depends on %a scanf then you may need to
> test for this conformance issue (instead of ifdef __GLIBC__
> because they may change the behaviour later or the cflag
> might not work on an older version etc)

I see. But I can avoid the GNU specific bevahiour by undefining 
_GNU_SOURCE if I want POSIX-conformance. In this case I do not need to 
test, but can rely on the libc of being conformal. Do I have this right?

eg, in FFmpeg/libavutils uses strerror_r which is implemented as a 
XSI-compliant and a GNU-specific version. If I want to be sure to get 
the XSI-compliant version, I unset _GNU_SOURCE and set 
_XOPEN_SOURCE=600. So I do not need any further testing here, right?