On Fri, Nov 5, 2021 at 9:34 AM Anders Roxell <anders.roxell@xxxxxxxxxx> wrote:
>
> When building selftests/timers with clang, the compiler warn about the
> function abs() see below:
>
> posix_timers.c:69:6: warning: absolute value function 'abs' given an argument of type 'long long' but has parameter of type 'int' which may cause truncation of value [-Wabsolute-value]
> if (abs(diff - DELAY * USECS_PER_SEC) > USECS_PER_SEC / 2) {
> ^
> posix_timers.c:69:6: note: use function 'llabs' instead
> if (abs(diff - DELAY * USECS_PER_SEC) > USECS_PER_SEC / 2) {
> ^~~
> llabs
>
> The note indicates what to do, Rework to use the function 'llabs()'.
>
> Signed-off-by: Anders Roxell <anders.roxell@xxxxxxxxxx>
Thanks for the patch!
Reviewed-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
I wonder why tools/testing/selftests/timers/adjtick.c redefines llabs
when it already includes stdlib.h, and how that doesn't result in some
kind of compiler diagnostic.
> ---
> tools/testing/selftests/timers/posix_timers.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/tools/testing/selftests/timers/posix_timers.c b/tools/testing/selftests/timers/posix_timers.c
> index 337424c5c987..73fb27901a1d 100644
> --- a/tools/testing/selftests/timers/posix_timers.c
> +++ b/tools/testing/selftests/timers/posix_timers.c
> @@ -66,7 +66,7 @@ static int check_diff(struct timeval start, struct timeval end)
> diff = end.tv_usec - start.tv_usec;
> diff += (end.tv_sec - start.tv_sec) * USECS_PER_SEC;
>
> - if (abs(diff - DELAY * USECS_PER_SEC) > USECS_PER_SEC / 2) {
> + if (llabs(diff - DELAY * USECS_PER_SEC) > USECS_PER_SEC / 2) {
> printf("Diff too high: %lld..", diff);
> return -1;
> }
> --
> 2.33.0
>
--
Thanks,
~Nick Desaulniers
