Re: [PATCH] kernel/bounds: Provide prototype for foo

[Greg Kroah-Hartman]

On Fri, Sep 21, 2018 at 03:22:33PM +0100, Kieran Bingham wrote:
> kernel/bounds.c is recompiled on every build, and shows the following
> warning when compiling with W=1:

Don't do that, you will get a lot of warnings that really don't make
much sense.  Like this one :)

> 
>   CC      kernel/bounds.s
> linux/kernel/bounds.c:16:6: warning: no previous prototype for âfooâ [-Wmissing-prototypes]
>  void foo(void)
>       ^~~
> 
> Provide a prototype to satisfy the compiler.
> 
> Signed-off-by: Kieran Bingham <kieran.bingham+renesas@xxxxxxxxxxxxxxxx>
> Cc: stable@xxxxxxxxxxxxxxx
> 
> ---
> I compile all of my incremental builds with W=1, which allows me to know
> instantly if I add a new compiler warning in code I generate.
> 
> This warning always comes up and seems trivial to clean up.
> ---
>  kernel/bounds.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/kernel/bounds.c b/kernel/bounds.c
> index c373e887c066..60136d937800 100644
> --- a/kernel/bounds.c
> +++ b/kernel/bounds.c
> @@ -13,6 +13,8 @@
>  #include <linux/log2.h>
>  #include <linux/spinlock_types.h>
>  
> +void foo(void);
> +
>  void foo(void)

This file is a userspace tool that is used to later generate the
include/generated/bounds.h file.

If you really want to track this down and fix it properly, put the
prototype in the .c file that ends up calling this function.  That's a
fun task to dig through the build system to find :)

good luck!

greg k-h