Re: Misleading messages from match 0.6.1-rc1

On Wed, Feb 05, 2020 at 08:51:11AM +0200, Toomas Soome wrote:
> 
> Hi!
> 
> While checking illumos soource, smatch is reporting:
> 
> /code/illumos-gate/usr/src/tools/proto/root_sparc-nd/opt/onbld/bin/sparc/smatch: ../../common/fs/ufs/ufs_vnops.c:737 wrip() warn: subtract is higher precedence than shift
> 
> The code is:
> 
> http://src.illumos.org/source/xref/illumos-gate/usr/src/uts/common/fs/ufs/ufs_vnops.c#737
> 
> limit = MIN(UFS_MAXOFFSET_T, limit);
> 
> Where MIN is defined:
> 
> #define	MIN(a, b)	((a) < (b) ? (a) : (b))
> 
> As seen from those facts, we have no subtraction nor shift. In code above, limit is unsigned 64-bit, UFS_MAXOFFSET_T is signed.
> 

It's complaining about UFS_MAXOFFSET_T.

#define	UFS_MAXOFFSET_T	((1LL << NBBY * sizeof (daddr32_t) + DEV_BSHIFT - 1) \
							- 1)

I assume the code is correct but adding parenthese around the
(DEV_BSHIFT - 1) doesn't help explain where the minus one comes from.

regards,
dan carpenter