Re: Best practice in C to support 64-bit or 32-bit address length with same source file ?

[Ken Raeburn <raeburn raeburn org>]

On May 3, 2008, at 16:49, Davis Johnson wrote:
> Rule 1 includes using NULL for null pointer values and not 0. It  
> also includes using %p to format pointer values. There are probably  
> some other things I should add.

NULL may be defined as 0, though.  In calling a variadic function like  
printf, *always* cast NULL (or 0) to the correct pointer type expected  
by the function; the compiler should automatically convert NULL or 0  
as needed in most other contexts.  In fact, for variadic functions,  
you should also make sure your integral-typed arguments are of the  
correct types, because passing a 64-bit long where the function  
expects a 32-bit int (or vice versa) may cause a mismatch in stack  
layout calculations.

Ken