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Re: CVS commit: src/sys/kern

Joerg Sonnenberger wrote:
> On Tue, Jan 31, 2012 at 07:32:52PM +0000, Alexander Nasonov wrote:
> > #define sizeof_fam(s, m, n) (sizeof(s) + sizeof(((s *)NULL)->m[0]) * (n))
> 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]).

I'm aware of this but I was merely following examples from the standard.

More specifically I was following DR 282 (flexible array members &
struct padding) which was incorporated into TC2.

I can add a comment about padding to sizeof_fam. If there is no padding,
my and your expression should return same values.


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