Re: [PATCH] hlist_for_each_safe cleanup

From: Herbert Xu
Date: Sun Jul 25 2004 - 04:38:34 EST


Stephen Hemminger <shemminger@xxxxxxxx> wrote:
> On Fri, 23 Jul 2004 23:22:23 +0200
>
>> What's wrong with using the comma operator instead of non-standard
>> statement expressions?
>
> It was more a case of consistency and avoiding the n = NULL assignment when pos
> is NULL.
>
> Look at hlist_for_each_entry_safe
>
> #define hlist_for_each_entry_safe(tpos, pos, n, head, member) \
> for (pos = (head)->first; \
> pos && ({ n = pos->next; 1; }) && \
> ({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \
> pos = n)
>
> What's your problem with the gcc extensions, the kernel uses them all over the place,
> planning on starting a conversion?

Yes but a comma operator will achieve exactly the same thing and is
more concise:

pos && (n = pos->next, 1) &&

You could also write

pos && ((n = pos->next) || 1) &&

Cheers,
--
Visit Openswan at http://www.openswan.org/
Email: Herbert Xu ~{PmV>HI~} <herbert@xxxxxxxxxxxxxxxxxxx>
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