Re: Bogus ifdef guard in sys/null.h

[Bernd Ernesti <netbsd%lists.veego.de@localhost>]

On Sat, Jul 17, 2010 at 12:16:13PM +0300, Stathis Kamperis wrote:
> Hi people,
> 
> in http://grok.x12.su/source/xref/netbsd/sys/sys/null.h ,
> the _SYS_NULL_H guard is bogus, since the whole header defines NULL
> only. And there's already a guard for NULL. The code as it is, breaks
> the following snippet:
> 
> % cat t.c
> #include <stddef.h>
> #undef NULL
> #include <unistd.h>

Doing that between two includes is the fault of the one who wrote that code.

[..]

> POSIX says that both stddef.h and unistd.h shall provide NULL. This
                                             ^^^^^
shall != must

So not a mandatory requirement.

Bernd