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SubjectRe: [PATCH 2.6.20-rc1] ib_verbs: Use explicit if-else statements to avoid errors with do-while macros
On Thu, Dec 14, 2006 at 06:44:30AM +0000, Al Viro wrote:
> On Wed, Dec 13, 2006 at 10:10:05PM -0500, Ben Collins wrote:
> > At least on PPC, the "op ? op : dma" construct causes a compile failure
> > because the dma_* is a do{}while(0) macro.
> >
> > This turns all of them into proper if/else to avoid this problem.
> NAK.
> Proper fix is to kill stupid do { } while (0) mess. It's supposed
> to behave like a function returning void, so it should be ((void)0).

BTW, even though the original patch is already merged, I think that
we ought to get rid of do-while in such stubs, exactly to avoid such
problems in the future. Probably even add to CodingStyle - it's not
the first time such crap happens.

IOW, do ; while(0) / do { } while (0) is not a proper way to do a macro
that imitates a function returning void.

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