_ATFILE_SOURCE Obsoletion

[Joseph Myers]

On Wed, 18 Oct 2017, Rical Jasan wrote:

> Does it really serve a useful purpose to broaden the definition of
> _ATFILE_SOURCE?  I understand the desire to cease support of historical

I think it makes sense to have a consistent approach to obsoletion of 
feature test macros that correspond to a subset of a supported feature.  
Currently, that approach involves mapping the macro to the supported 
superset feature.

_BSD_SOURCE and _SVID_SOURCE now imply _DEFAULT_SOURCE (with a warning).

_REENTRANT and _THREAD_SAFE now imply _POSIX_C_SOURCE=199506L, if no later 
version of POSIX would otherwise have been used.

-- 
Joseph S. Myers
joseph@codesourcery.com