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From: Pavel Machek <pavel@ucw.cz>
To: David Brownell <david-b@pacbell.net>
Cc: linux-pm@lists.linux-foundation.org,
	Anton Vorontsov <cbouatmailru@gmail.com>,
	linux-kernel@vger.kernel.org
Subject: Re: [linux-pm] [PATCH RFC] introduce pm_call() macro to get rid of most #ifdef CONFIG_PM
Date: Tue, 4 Mar 2008 00:16:43 +0100	[thread overview]
Message-ID: <20080303231643.GL13869@elf.ucw.cz> (raw)
In-Reply-To: <200803031456.38406.david-b@pacbell.net>

Hi!


> > > +/* avoid `defined but not used' warning */
> > > +#define pm_call(x) ((x) - 1 ? NULL : NULL)
> > > +#endif /* CONFIG_PM */
> > > +
> > 
> > This is evil.
> 
> Ugly, yes.  It might merit some casts too.
> 
> 
> > Maybe your gcc is smart enough to optimize this away, 
> > but I'm not sure mine is.
> 
> It'll be a constant expression; it certainly ought to be.

Well, we have just fooler compiler to think that x is used, and now we
want it to realize that x is unused and compile it out?

Maybe it is smart enough, but...
									Pavel
-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

      reply	other threads:[~2008-03-03 23:16 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-03-02 23:43 Anton Vorontsov
2008-03-03  0:08 ` Arjan van de Ven
2008-03-03  0:29   ` Rafael J. Wysocki
2008-03-03 23:26   ` Anton Vorontsov
2008-03-03 14:18 ` Pavel Machek
2008-03-03 22:42   ` Anton Vorontsov
2008-03-03 22:56   ` [linux-pm] " David Brownell
2008-03-03 23:16     ` Pavel Machek [this message]

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