On Fri, 2018-05-18 at 17:23 +0000, Sean Bruno wrote: > Author: sbruno > Date: Fri May 18 17:23:23 2018 > New Revision: 333801 > URL: https://svnweb.freebsd.org/changeset/base/333801 > > Log: > Quiesce a couple pages of clang warnings with a cast. Duplicates > linux maintainer commit: > > > https://github.com/torvalds/linux/commit/627871b71c89a6ec12fbed75063f238e0c7127b2#diff-8c6ddb4c3ad69a6fb9f289475821db56 > > ar9300template_aphrodite.h:575:40: warning: implicit conversion from 'int' > to 'u_int8_t' (aka 'unsigned char') changes value from 3495 to 167 > [-Wconstant-conversion] > /* Data[8].ctl_edges[7].bChannel*/FREQ2FBIN(5795, 0)} > ^~~~~~~~~~~~~~~~~~ > ar9300eep.h:142:41: note: expanded from macro 'FREQ2FBIN' > (((y) == HAL_FREQ_BAND_2GHZ) ? ((x) - 2300) : (((x) - 4800) / 5)) > > Reviewed by: imp > MFC after: 1 week > Differential Revision: https://reviews.freebsd.org/D15476 > > Modified: > head/sys/contrib/dev/ath/ath_hal/ar9300/ar9300eep.h > > Modified: head/sys/contrib/dev/ath/ath_hal/ar9300/ar9300eep.h > ============================================================================== > --- head/sys/contrib/dev/ath/ath_hal/ar9300/ar9300eep.h Fri May 18 > 17:07:59 2018 (r333800) > +++ head/sys/contrib/dev/ath/ath_hal/ar9300/ar9300eep.h Fri May 18 > 17:23:23 2018 (r333801) > @@ -139,7 +139,7 @@ enum Ar9300EepromTemplate > #define OSPREY_CUSTOMER_DATA_SIZE 20 > > #define FREQ2FBIN(x,y) \ > - (((y) == HAL_FREQ_BAND_2GHZ) ? ((x) - 2300) : (((x) - 4800) / 5)) > + (u_int8_t)(((y) == HAL_FREQ_BAND_2GHZ) ? ((x) - 2300) : (((x) - 4800) / > 5)) > #define FBIN2FREQ(x,y) \ > (((y) == HAL_FREQ_BAND_2GHZ) ? (2300 + x) : (4800 + 5 * x)) > #define OSPREY_MAX_CHAINS 3 >
How can this change possibly be correct? All the values involved are compile-time constants, the compiler did the math and tells you the result is 3495. Cast or not, that value is never going to fit into a uint8_t. Sure this supresses the warning, but what about actually fixing the overflow? -- Ian _______________________________________________ svn-src-all@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-all To unsubscribe, send any mail to "svn-src-all-unsubscr...@freebsd.org"
