Hi Miguel, On Sun, Oct 7, 2018 at 6:18 AM Miguel Ojeda <miguel.ojeda.sandonis@xxxxxxxxx> wrote: > > On Fri, Oct 5, 2018 at 10:35 AM Arnd Bergmann <arnd@xxxxxxxx> wrote: > > > > Building any configuration with 'make W=1' produces a warning: > > > > kernel/bounds.c:16:6: warnign: no previous prototype for 'foo' [-Wmissing-prototypes] > > > > When also passing -Werror, this prevents us from building any > > other files. Nobody ever calls the function, but we can't make > > it 'static' either since we want the compiler output. > > > > Calling it 'main' instead however avoids the warning, because gcc > > does not insist on having a declaration for main. > > I think marking the function as static __used should do the trick and > would be less confusing. I tried __used, but I still see the warning. masahiro@grover:~/ref/linux$ git diff diff --git a/kernel/bounds.c b/kernel/bounds.c index c373e88..aee0101 100644 --- a/kernel/bounds.c +++ b/kernel/bounds.c @@ -13,7 +13,7 @@ #include <linux/log2.h> #include <linux/spinlock_types.h> -void foo(void) +void __used foo(void) { /* The enum constants to put into include/generated/bounds.h */ DEFINE(NR_PAGEFLAGS, __NR_PAGEFLAGS); masahiro@grover:~/ref/linux$ make W=1 prepare CC kernel/bounds.s kernel/bounds.c:16:13: warning: no previous prototype for ‘foo’ [-Wmissing-prototypes] void __used foo(void) ^ CC arch/x86/kernel/asm-offsets.s -- Best Regards Masahiro Yamada