Neil Conway <neilc@samurai.com> writes:
> Ah, good catch! Upon further investigation, you're completely correct:
> technically, you need to cast the NULL literal to a pointer type in a
> function call if (a) there is no prototype for the function, or (b)
> the function is a varargs function (which execl() is).
> I'd imagine it would only make a difference on a machine where the
> null pointer is represented by a non-zero bit pattern (i.e. it
> shouldn't make a difference on any modern machine),
Actually, I think it would be likely to be important on any machine
where sizeof(pointer) != sizeof(int), which is reasonably common
in 64-bit-pointer land. C99 saith
An integer constant expression with the value 0, or
such an expression cast to type void *, is called a null
pointer constant.
So one plausible definition of NULL is just "#define NULL 0", and
without the explicit cast it would probably be taken as an integer
argument, which would be the wrong size.
> but we should do this correctly, of course.
Check.
> I won't bother posting an updated patch, but I'll include your fix in
> the patch when I apply it. Thanks again.
Sounds good.
regards, tom lane
