[patch] Let stddef.h redefine NULL if __need_NULL is set

[Joerg Sonnenberger]

On Sun, Apr 27, 2014 at 05:13:16PM -0700, Nico Weber wrote:
> On Sun, Apr 27, 2014 at 4:07 PM, Joerg Sonnenberger
> <joerg at britannica.bec.de> wrote:
> > On Sun, Apr 27, 2014 at 02:50:16PM -0700, Nico Weber wrote:
> >> small.cc:6:18: error: missing sentinel in function call [-Werror,-Wsentinel]
> >>   foo("bar", NULL);
> >
> > This is just broken code. Why we do we want to workaround that?
> 
> Linux is kind of common, and there's no good way to work around this
> problem on an application code level that I can see.

Yes, there is. It has always been the case that portable code *must* use
(void *)NULL or equivalent as sentinal. For C++11, nullptr is
acceptable, for C++03 NULL is not.

Joerg