Re: [PATCH] kbuild: fix kernel/bounds.c 'W=1' warning

[Masahiro Yamada <yamada.masahiro@socionext.com>]

On Sun, Oct 7, 2018 at 6:58 AM Masahiro Yamada
<yamada.masahiro@socionext.com> wrote:
>
> Hi Miguel,
>
>
> On Sun, Oct 7, 2018 at 6:18 AM Miguel Ojeda
> <miguel.ojeda.sandonis@gmail.com> wrote:
> >
> > On Fri, Oct 5, 2018 at 10:35 AM Arnd Bergmann <arnd@arndb.de> 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



Sorry, I forgot to add 'static'.

Adding both static and __used worked for me,
and I like the idea.



-- 
Best Regards
Masahiro Yamada