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Date: Sun, 8 Mar 2009 09:26:12 +0200
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Subject: Re: [Qemu-devel] [6737] Sparse fixes: truncation by cast
From: Blue Swirl <blauwirbel@gmail.com>
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To: qemu-devel@nongnu.org

On 3/7/09, Luca Tettamanti <kronos.it@gmail.com> wrote:
> On Sat, Mar 7, 2009 at 4:46 PM, Blue Swirl <blauwirbel@gmail.com> wrote:
>  > Revision: 6737
>  >          http://svn.sv.gnu.org/viewvc/?view=rev&root=qemu&revision=6737
>  > Author:   blueswir1
>  > Date:     2009-03-07 15:46:23 +0000 (Sat, 07 Mar 2009)
>  > Log Message:
>  > -----------
>  > Sparse fixes: truncation by cast
>  >
>  > Fix Sparse warnings about constant truncation caused by cast
>  >
>
> > Modified: trunk/bswap.h
>  > ===================================================================
>  > --- trunk/bswap.h       2009-03-07 15:32:56 UTC (rev 6736)
>  > +++ trunk/bswap.h       2009-03-07 15:46:23 UTC (rev 6737)
>  > @@ -151,7 +151,7 @@
>  >  {
>  >     uint8_t *p1 = (uint8_t *)p;
>  >
>  > -    p1[0] = v;
>  > +    p1[0] = v & 0xff;
>  >     p1[1] = v >> 8;
>
>
> Hum, by the same principle the last line should be:
>  p1[1] = (v >> 8) & 0xff;
>  no?

Maybe and there would be other similar places, but there is no warning
from Sparse except for this. Instead of "fix" I should have used
something like "suppress" because the code wasn't broken, it's just
that now Sparse is much more silent and real warnings are more visible
from the noise.