[kbuild-all] lib/atomic64.c:124:1: warning: no previous prototype for function 'generic_atomic64_and_return'

tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master head: debe436e77c72fcee804fb867f275e6d31aa999c commit: 1bdadf46eff6804ace5fa46b6856da4799f12b5c locking/atomic: atomic64: support ARCH_ATOMIC date: 6 months ago config: arm-randconfig-c002-20211109 (attached as .config) compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project f3798ad5fa845771846599f3c088016e3aef800c) reproduce (this is a W=1 build): wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross # install arm cross compiling tool for clang build # apt-get install binutils-arm-linux-gnueabi # https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit... git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git git fetch --no-tags linus master git checkout 1bdadf46eff6804ace5fa46b6856da4799f12b5c # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 ARCH=arm If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All warnings (new ones prefixed by >>): ATOMIC64_OPS(and, &=) ^ lib/atomic64.c:121:2: note: expanded from macro 'ATOMIC64_OPS' ATOMIC64_OP_RETURN(op, c_op) \ ^ lib/atomic64.c:82:5: note: expanded from macro 'ATOMIC64_OP_RETURN' s64 generic_atomic64_##op##_return(s64 a, atomic64_t *v) \ ^ <scratch space>:147:1: note: expanded from here generic_atomic64_and_return ^ lib/atomic64.c:124:1: note: declare 'static' if the function is not intended to be used outside of this translation unit lib/atomic64.c:121:2: note: expanded from macro 'ATOMIC64_OPS' ATOMIC64_OP_RETURN(op, c_op) \ ^ lib/atomic64.c:81:42: note: expanded from macro 'ATOMIC64_OP_RETURN' #define ATOMIC64_OP_RETURN(op, c_op) \ ^ ATOMIC64_OPS(or, |=) ^ lib/atomic64.c:121:2: note: expanded from macro 'ATOMIC64_OPS' ATOMIC64_OP_RETURN(op, c_op) \ ^ lib/atomic64.c:82:5: note: expanded from macro 'ATOMIC64_OP_RETURN' s64 generic_atomic64_##op##_return(s64 a, atomic64_t *v) \ ^ <scratch space>:161:1: note: expanded from here generic_atomic64_or_return ^ lib/atomic64.c:125:1: note: declare 'static' if the function is not intended to be used outside of this translation unit lib/atomic64.c:121:2: note: expanded from macro 'ATOMIC64_OPS' ATOMIC64_OP_RETURN(op, c_op) \ ^ lib/atomic64.c:81:42: note: expanded from macro 'ATOMIC64_OP_RETURN' #define ATOMIC64_OP_RETURN(op, c_op) \ ^ ATOMIC64_OPS(xor, ^=) ^ lib/atomic64.c:121:2: note: expanded from macro 'ATOMIC64_OPS' ATOMIC64_OP_RETURN(op, c_op) \ ^ lib/atomic64.c:82:5: note: expanded from macro 'ATOMIC64_OP_RETURN' s64 generic_atomic64_##op##_return(s64 a, atomic64_t *v) \ ^ <scratch space>:175:1: note: expanded from here generic_atomic64_xor_return ^ lib/atomic64.c:126:1: note: declare 'static' if the function is not intended to be used outside of this translation unit lib/atomic64.c:121:2: note: expanded from macro 'ATOMIC64_OPS' ATOMIC64_OP_RETURN(op, c_op) \ ^ lib/atomic64.c:81:42: note: expanded from macro 'ATOMIC64_OP_RETURN' #define ATOMIC64_OP_RETURN(op, c_op) \ ^ 3 warnings generated. vim +/generic_atomic64_and_return +124 lib/atomic64.c 560cb12a4080a4 Peter Zijlstra 2014-04-23 117 560cb12a4080a4 Peter Zijlstra 2014-04-23 118 #undef ATOMIC64_OPS 28aa2bda2211f4 Peter Zijlstra 2016-04-18 119 #define ATOMIC64_OPS(op, c_op) \ 28aa2bda2211f4 Peter Zijlstra 2016-04-18 120 ATOMIC64_OP(op, c_op) \ 28aa2bda2211f4 Peter Zijlstra 2016-04-18 121 ATOMIC64_OP_RETURN(op, c_op) \ 28aa2bda2211f4 Peter Zijlstra 2016-04-18 122 ATOMIC64_FETCH_OP(op, c_op) 28aa2bda2211f4 Peter Zijlstra 2016-04-18 123 28aa2bda2211f4 Peter Zijlstra 2016-04-18 @124 ATOMIC64_OPS(and, &=) 28aa2bda2211f4 Peter Zijlstra 2016-04-18 @125 ATOMIC64_OPS(or, |=) 28aa2bda2211f4 Peter Zijlstra 2016-04-18 @126 ATOMIC64_OPS(xor, ^=) 28aa2bda2211f4 Peter Zijlstra 2016-04-18 127 :::::: The code at line 124 was first introduced by commit :::::: 28aa2bda2211f4327d83b44a4f917b4a061b1c56 locking/atomic: Implement atomic{,64,_long}_fetch_{add,sub,and,andnot,or,xor}{,_relaxed,_acquire,_release}() :::::: TO: Peter Zijlstra <peterz(a)infradead.org&gt; :::::: CC: Ingo Molnar <mingo(a)kernel.org&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org