Moving to AMD64 bit and porting issues

[Ernest L. Williams Jr.]

On Fri, 2005-11-04 at 12:28 +0100, Segher Boessenkool wrote:
> > You can reliably use 0 as a null pointer constant with one exception.
> > When calling a varargs function which expects a pointer as an unnamed
> > argument, and when pointers are 64-bits but int is 32-bits, then you
> > must either use NULL or you must cast 0 to a pointer type.
> 
> Using NULL in this case is not portable; you *must*
> use a cast to the exact pointer type that the
> varargs function expects to see.  Different pointer
> types can have different representation.

However, it does seem that must platforms understand NULL and assigns
the correct type.  I do agree that for portability we should use the
cast.



Ernest



> 
> 
> Segher
>