Re: [PATCH] make WRITE_ONCE return void

From: Peter Zijlstra
Date: Fri Jul 08 2016 - 04:02:24 EST


On Fri, Jul 08, 2016 at 01:20:08AM +0300, Alexey Dobriyan wrote:
> Currently WRITE_ONCE is used as if it returns void. Let's codify this
> before somebody tries to be smarter than necessary.
>
> Signed-off-by: Alexey Dobriyan <adobriyan@xxxxxxxxx>
> ---
>
> include/linux/compiler.h | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> --- a/include/linux/compiler.h
> +++ b/include/linux/compiler.h
> @@ -301,7 +301,7 @@ static __always_inline void __write_once_size(volatile void *p, void *res, int s
> union { typeof(x) __val; char __c[1]; } __u = \
> { .__val = (__force typeof(x)) (val) }; \
> __write_once_size(&(x), __u.__c, sizeof(x)); \
> - __u.__val; \
> + (void)0; \
> })

Why then still use the statement expression? Would it not make more
sense to change it into the regular do { } while (0) form if you want to
remove the return semantics?