Re: [PATCH] staging: lustre: shut up clang warnings on CLASSERT()

[Dilger, Andreas]

On Feb 1, 2017, at 09:52, Arnd Bergmann <arnd@xxxxxxxx> wrote:
> 
> lustre uses a fake switch() statement as a compile-time assert, but unfortunately
> each use of that causes a warning when building with clang:
> 
> drivers/staging/lustre/lnet/klnds/socklnd/socklnd.c:2907:2: warning: no case matching constant switch condition '42'
> drivers/staging/lustre/lnet/klnds/socklnd/../../../include/linux/libcfs/libcfs_private.h:294:36: note: expanded from macro 'CLASSERT'
> #define CLASSERT(cond) do {switch (42) {case (cond): case 0: break; } } while (0)
> 
> Adding a 'default:' label in there shuts up the warning.
> 
> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>

Reviewed-by: Andreas Dilger <andreas.dilger@xxxxxxxxx>

> ---
> drivers/staging/lustre/include/linux/libcfs/libcfs_private.h | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/staging/lustre/include/linux/libcfs/libcfs_private.h b/drivers/staging/lustre/include/linux/libcfs/libcfs_private.h
> index aab15d8112a4..2d5435029185 100644
> --- a/drivers/staging/lustre/include/linux/libcfs/libcfs_private.h
> +++ b/drivers/staging/lustre/include/linux/libcfs/libcfs_private.h
> @@ -291,7 +291,7 @@ do {							    \
>  *       value  after  conversion...
>  *
>  */
> -#define CLASSERT(cond) do {switch (42) {case (cond): case 0: break; } } while (0)
> +#define CLASSERT(cond) do {switch (42) {case (cond): case 0: default: break; } } while (0)
> 
> /* max value for numeric network address */
> #define MAX_NUMERIC_VALUE 0xffffffff
> -- 
> 2.9.0
> 

Cheers, Andreas
--
Andreas Dilger
Lustre Principal Architect
Intel Corporation