Re: Fix empty macros in acpi.

From: Al Viro
Date: Tue Jun 12 2007 - 20:26:40 EST


On Tue, Jun 12, 2007 at 08:21:15PM -0400, Dave Jones wrote:
> On Wed, Jun 13, 2007 at 01:00:29AM +0100, Al Viro wrote:
> > On Tue, Jun 12, 2007 at 07:33:09PM -0400, Dave Jones wrote:
> > > +#define DBG(x...) do { } while(0)
> >
> > Eh... Please, stop it - if you want a function-call-like no-op returning void,
> > use ((void)0). At least that way one can say DBG(....),foo(), etc.
>
> They both end up compiled to nothing anyway, so I'm not bothered
> either way.. I'm not sure I follow why the syntax of that last part
> is a good thing. It looks like something we'd want to avoid rather
> than promote?

If on one side of ifdef it's a void-valued expression, so it should be
on another; the reason is that we don't get surprise differences between
the builds...

IOW, if it doesn't build in some context, it should consistently fail to
build in that context.
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