Re: [PATCH] Use NULL instead of integer 0 in security/selinux/

[P. Benie]

On Thu, 8 Jul 2004, Michael Poole wrote:
> Could you please elaborate the rules of English in which "An integer
> constant expresion with the value 0 [...] is called a null pointer
> constant" does not mean that 0 is a null pointer?  0 is certainly an
> integer constant expression with the value 0, so there must be
> something extraordinarily subtle in the second half of the sentence.

He's emphasising the difference between "null pointer constant"  and "null
pointer", however NULL is defined as "an implementation-defined null
pointer constant", so any subtle issues regarding 0 apply equally well to
NULL.

Someone pointed out that there can be a difference between 0 and NULL when
passing the value to a function lacking a prototype. There's no guarantee
that the null pointers of different types have the same representation, so
passing NULL into such a function without an explicit cast would also be
incorrect.

Peter
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