Re: [netfilter-nf:testing 11/20] net/netfilter/ipset/ip_set_hash_gen.h:379:21: warning: result of comparison of constant -1 with expression of type 'u8' (aka 'unsigned char') is always false

[Florian Westphal <fw@strlen.de>]

kernel test robot <lkp@intel.com> wrote:
> tree:   https://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf.git testing
> head:   c2fbcb9151957c3d921a7441cf080e49eb13b05d
> commit: a900abcb974bae821a5d4ae79ad3442808915416 [11/20] netfilter: ipset: rework cidr bookkeeping
> config: x86_64-rhel-9.4-rust (https://download.01.org/0day-ci/archive/20260708/202607081250.ODagxDyb-lkp@intel.com/config)
> compiler: clang version 22.1.8 (https://github.com/llvm/llvm-project ca7933e47d3a3451d81e72ac174dcb5aa28b59d1)
> reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260708/202607081250.ODagxDyb-lkp@intel.com/reproduce)
> 
> If you fix the issue in a separate patch/commit (i.e. not just a new version of
> the same patch/commit), kindly add following tags
> | Reported-by: kernel test robot <lkp@intel.com>
> | Closes: https://lore.kernel.org/oe-kbuild-all/202607081250.ODagxDyb-lkp@intel.com/
> 
> All warnings (new ones prefixed by >>):
> 
>    In file included from net/netfilter/ipset/ip_set_hash_ipportnet.c:131:
> >> net/netfilter/ipset/ip_set_hash_gen.h:379:21: warning: result of comparison of constant -1 with expression of type 'u8' (aka 'unsigned char') is always false [-Wtautological-constant-out-of-range-compare]
>      379 |         if (unlikely(found == -1))
>          |                      ~~~~~ ^  ~~
>    include/linux/compiler.h:77:42: note: expanded from macro 'unlikely'
>       77 | # define unlikely(x)    __builtin_expect(!!(x), 0)
>          |                                             ^
>    In file included from net/netfilter/ipset/ip_set_hash_ipportnet.c:391:
> >> net/netfilter/ipset/ip_set_hash_gen.h:379:21: warning: result of comparison of constant -1 with expression of type 'u8' (aka 'unsigned char') is always false [-Wtautological-constant-out-of-range-compare]
>      379 |         if (unlikely(found == -1))
>          |                      ~~~~~ ^  ~~
>    include/linux/compiler.h:77:42: note: expanded from macro 'unlikely'
>       77 | # define unlikely(x)    __builtin_expect(!!(x), 0)
>          |                                             ^
>    2 warnings generated.

FYI, I removed this patch from the batch that I sent to net tree.