[TUHS] reviving a bit of WWB

[Steffen Nurpmeso]

Steve Nickolas wrote in
 <alpine.DEB.2.21.2009201654300.10605 at sd-119843.dedibox.fr>:
 |On Sun, 20 Sep 2020, Doug McIlroy wrote:
 |
 |>> (Of course, that assumes NULL is 0, but I don't think I've run into any
 |>> architecture so braindead as to not have NULL=0.)
 |>
 |> It has nothing to do with machine architecture. The C standard
 |> says 0 coerces to the null pointer. NULL, defined in <stddef.h>,
 |> is part of the library, not the language. I always use 0,
 |> because NULL is a frill.
 |>
 |> Doug
 |
 |I was under the impression that there was explicitly no requirement that a 
 |null pointer be 0, and that there was at least one weird system where that 
 |wasn't true - that it just so happened that null points to 0 on certain 
 |CPUs and that 0=NULL *happens* to work on most CPUs but wasn't guaranteed. 
 |(In fact, I read that my habit of using 0 for NULL relied on a faulty 
 |assumption!)
 |
 |I mean, I've never actually used a CPU/OS/compiler where it wasn't true, 
 |but...

I remember having to use __null for __GNUC__>=3 because 0x0 (what
is used for my NIL macro before, this was C++) did not work out
well.  (Could have been compiler bug, of course .. but i just
remembered it when reading your post.)

--steffen
|
|Der Kragenbaer,                The moon bear,
|der holt sich munter           he cheerfully and one by one
|einen nach dem anderen runter  wa.ks himself off
|(By Robert Gernhardt)