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Date: Tue, 9 Jun 2009 14:56:07 -0700
From: Andrew Morton <akpm@linux-foundation.org>
To: Jon Masters <jonathan@jonmasters.org>
Cc: linux-kernel@vger.kernel.org, tglx@linutronix.de, mingo@elte.hu,
       rostedt@goodmis.org
Subject: Re: [RFC PATCH 1/1] smi_detector: A System Management Interrupt
 detector
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On Tue, 09 Jun 2009 17:50:01 -0400
Jon Masters <jonathan@jonmasters.org> wrote:

> > > +	if (0 != err)
> > 
> > 	if (err != 0)
> > 
> > or
> > 
> > 	if (err)
> > 
> > would be more typical.
> 
> The former runs the risk of assignment,

yup, which is why gcc will warn if you do

	if (err = 0)

If you really meant to do that, then gcc can be silenced by
double-parenthesising.  We consider this "good enough" for kernel
purposes, so we generally don't use the `if (CONSTANT == variable)' trick.


> whereas <value> != <variable>
> will generate a compiler error if it goes wrong, so I trained myself to
> always do that. The desired value is zero, so I prefer to show that in
> the test, but I have changed it following your advice anyway - it's like
> how I have to force myself not to use '{' '}' on single line
> if-statements despite generally doing so, again for safety :)
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