[c++] warn if NULL is passed through varargs

[Paul Koning]

>>>>> "Fergus" == Fergus Henderson <fjh@cs.mu.oz.au> writes:

 Fergus> On 11-Oct-2002, Paul Koning <pkoning@equallogic.com> wrote:
 >> >>>>> "Richard" == Richard Henderson <rth@redhat.com> writes:
 >> 
 Richard> On Fri, Oct 11, 2002 at 11:09:20AM -0400, Paul Koning wrote:
 >> >> So are you saying that the C standard's statement that 0 is a
 >> >> valid way to say "NULL pointer" is wrong, and anyone who relies
 >> on >> it is writing broken code?

 Fergus> The C standard doesn't say that.  The C standard says that 0
 Fergus> *if converted to a pointer type* is a null pointer.  But
 Fergus> passing 0 through varargs does not count as converting it to
 Fergus> a pointer type.

 Fergus> So yes, anyone who relies on this is writing broken code -
 Fergus> albeit broken code that happens to work on most current C
 Fergus> implementations.

Ok, I see the point.  This all makes sense now.

    paul