Re: _NETBSD_SOURCE always defined leading to unwanted inclusions

[David Holland <dholland-tech%netbsd.org@localhost>]

On Sat, Apr 20, 2019 at 10:30:48PM +0200, tlaronde%polynum.com@localhost wrote:
 > [I changed the subject because this was lost in the end of a message
 > about _STANDALONE]
 > 
 > When one does not specify something special (_ANSI_SOURCE or
 > _POSIX_C_SOURCE or _XOPEN_SOURCE), _NETBSD_SOURCE is always defined
 > due to the inclusion of sys/featuretest.h almost everywhere.

Yes, that's intentional.

 > This leads to the inclusion of some chunks of code in <sys/time.h>,
 > specially the definition of static functions (supposed to be inlined but
 > this will depend on the compiler and on the flags--- -fno-inline).
 > 
 > A first problem (YMMV) is that <time.h> can not be included anywhere
 > but only outside of a block, since there are definitions and not only
 > declarations.

Don't do that. You can't expect any header not specifically prepared
for the purpose to work correctly if included somewhere other than the
top level.

 > The second problem is that the functions are not prefixed by '_' and can
 > conflict with locally defined functions.

Those functions are part of the library API. If you want to restrict
what's defined, use _POSIX_C_SOURCE or one of its many cousins.

-- 
David A. Holland
dholland%netbsd.org@localhost