On Tue, Jun 15, 2021 at 11:32 AM Nathan Chancellor <nathan@xxxxxxxxxx> wrote: > > On Tue, Jun 15, 2021 at 05:03:40PM +0100, Matthew Wilcox wrote: > > On Tue, Jun 15, 2021 at 11:58:36PM +0800, kernel test robot wrote: > > > COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=arm64 > > > > > > If you fix the issue, kindly add following tag as appropriate > > > Reported-by: kernel test robot <lkp@xxxxxxxxx> > > > > > > All warnings (new ones prefixed by >>): > > > > > > >> mm/hugetlb.c:1591:9: warning: no previous prototype for function 'hugetlb_basepage_index' [-Wmissing-prototypes] > > > pgoff_t hugetlb_basepage_index(struct page *page) > > > > So clang requires the prototype to still be in scope, while gcc doesn't. > > Does one of our clangers want to file a bug about that? > > I see the exact same warning with GCC 11.1.0: > > $ curl -LSs https://lore.kernel.org/linux-mm/202106152328.Mh5S48hE-lkp@xxxxxxxxx/2-a.bin | gzip -d > .config > > $ make -skj"$(nproc)" ARCH=arm64 CROSS_COMPILE=aarch64-linux- W=1 olddefconfig mm/hugetlb.c > mm/hugetlb.c:1591:9: warning: no previous prototype for 'hugetlb_basepage_index' [-Wmissing-prototypes] > 1591 | pgoff_t hugetlb_basepage_index(struct page *page) > | ^~~~~~~~~~~~~~~~~~~~~~ Since this is a commonly recurring warning for W=1 builds, then this function either should be declared as having static linkage if its uses are local to the same file, or a prototype should be declared in a header so that callers and callee agree on function signature. -- Thanks, ~Nick Desaulniers
