Messages in this thread | | | From | Andy Shevchenko <> | Date | Tue, 5 May 2020 17:08:23 +0300 | Subject | Re: [PATCH] bitops: avoid clang shift-count-overflow warnings |
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On Tue, May 5, 2020 at 4:58 PM Arnd Bergmann <arnd@arndb.de> wrote: > > Clang normally does not warn about certain issues in inline functions when > it only happens in an eliminated code path. However if something else > goes wrong, it does tend to complain about the definition of hweight_long() > on 32-bit targets:
Shouldn't it be fixed in CLang?
> include/linux/bitops.h:75:41: error: shift count >= width of type [-Werror,-Wshift-count-overflow] > return sizeof(w) == 4 ? hweight32(w) : hweight64(w); > ^~~~~~~~~~~~
sizeof(w) is compile-time constant. It can easily drop the second part without even looking at it.
> Adding an explicit cast to __u64 avoids that warning and makes it easier > to read other output.
Looks like papering over the real issue.
-- With Best Regards, Andy Shevchenko
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