Jaromir Dolecek wrote:
> 
> $subject says it pretty much all.
> 
> The effect of _GNU_SOURCE should be pretty much equal to
> _NETBSD_SOURCE, e.g. expose all extensions. There is some software
> which defines _GNU_SOURCE along with _POSIX_C_SOURCE or _XOPEN_SOURCE,
> which fails to build due to not exposed prototypes.
> 
> Yeah, _GNU_SOURCE is totally nonstandard, but supporting it would
> help porting 3rd party software written for Linux.

Sun:
__EXTENSIONS__
_XOPEN_SOURCE_EXTENDED

HP/UX:
_INCLUDE_XOPEN_SOURCE_EXTENDED
_XOPEN_SOURCE_EXTENDED
_INCLUDE_HPUX_SOURCE
_XPG4_EXTENDED

AIX:
_XOPEN_SOURCE_EXTENDED

Summary:  _GNU_SOURCE is not non-standard.  Everyone picks their own
standard, and GNU isn't any different.  Personally, I just add every
new one I bump into.  I'll be adding "_NETBSD_SOURCE" now, though
it *would* be nice if _GNU_SOURCE implied _NETBSD_SOURCE.  :)

Cheers - Bruce