Re: [PATCH] locktorture.c: fix if-statement empty body warnings

From: Paul E. McKenney
Date: Thu Feb 27 2020 - 09:53:03 EST


On Tue, Feb 25, 2020 at 09:09:19PM -0800, Randy Dunlap wrote:
> From: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
>
> When using -Wextra, gcc complains about torture_preempt_schedule()
> when its definition is empty (i.e., when CONFIG_PREEMPTION is not
> set/enabled). Fix these warnings by adding an empty do-while block
> for that macro when CONFIG_PREEMPTION is not set.
> Fixes these build warnings:
>
> ../kernel/locking/locktorture.c:119:29: warning: suggest braces around empty body in an âifâ statement [-Wempty-body]
> ../kernel/locking/locktorture.c:166:29: warning: suggest braces around empty body in an âifâ statement [-Wempty-body]
> ../kernel/locking/locktorture.c:337:29: warning: suggest braces around empty body in an âifâ statement [-Wempty-body]
> ../kernel/locking/locktorture.c:490:29: warning: suggest braces around empty body in an âifâ statement [-Wempty-body]
> ../kernel/locking/locktorture.c:528:29: warning: suggest braces around empty body in an âifâ statement [-Wempty-body]
> ../kernel/locking/locktorture.c:553:29: warning: suggest braces around empty body in an âifâ statement [-Wempty-body]
>
> I have verified that there is no object code change (with gcc 7.5.0).
>
> Signed-off-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>

Queued for v5.8, thank you very much!

Thanx, Paul

> Cc: Davidlohr Bueso <dave@xxxxxxxxxxxx>
> Cc: "Paul E. McKenney" <paulmck@xxxxxxxxxx>
> Cc: Josh Triplett <josh@xxxxxxxxxxxxxxxx>
> ---
> include/linux/torture.h | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> --- linux-next-20200225.orig/include/linux/torture.h
> +++ linux-next-20200225/include/linux/torture.h
> @@ -89,7 +89,7 @@ void _torture_stop_kthread(char *m, stru
> #ifdef CONFIG_PREEMPTION
> #define torture_preempt_schedule() preempt_schedule()
> #else
> -#define torture_preempt_schedule()
> +#define torture_preempt_schedule() do { } while (0)
> #endif
>
> #endif /* __LINUX_TORTURE_H */
>