Warning for unadorned 0 in varargs lists?

[Eddie Kohler]

Hi all,

I habitually use "0" for a null pointer, which causes serious problems 
on 64-bit machines when passed to a varargs function.

So an optional [i.e. no -Wall] GCC warning that complained when an 
unadorned, uncast "0" was passed to a varargs function would help me a 
lot, and probably others.

Would such a warning be considered for inclusion in GCC?  Or do people 
think it might generate too many false positives?

Eddie Kohler