Re: CVS commit: src/sys/kern

[David Laight <david%l8s.co.uk@localhost>]

On Tue, Jan 31, 2012 at 09:51:17PM +0000, Alexander Nasonov wrote:
> Joerg Sonnenberger wrote:
> > That's still not necessarily optimal, depending on the padding rules of
> > the platform. You want to do offsetof(s, m[0]) + n * sizeof((s*)NULL->m[0]).
> 
> Using m[0] inside offsetof is non-standard but I think this will work:
> 
> offsetof(s, m) + n * sizeof((s*)NULL->m[0]).

I don't believe there is a problem using m[0], just m[non-constant-expr].

OTOH 'sizeof (s *)0->m[0]' might be deemed invalid (because it has
an inferred dereference of NULL.

        David

-- 
David Laight: david%l8s.co.uk@localhost