On May 23, 2006, at 10:25 AM, Izumi Tsutsui wrote:

> thorpej@shagadelic.org wrote:
>
>> The (void) casts are intended to consume all of the arguments.
>
> Is this patch acceptable to suppress gcc4's
> "left-hand operand of comma expression has no effect"
> warning, or is there any better answer? (use do{}while(0)?)

Yours looks fine.

> ---
> Izumi Tsutsui
>
>
> Index: arch/cobalt/include/bus.h
> ===================================================================
> RCS file: /cvsroot/src/sys/arch/cobalt/include/bus.h,v
> retrieving revision 1.18
> diff -u -r1.18 bus.h
> --- arch/cobalt/include/bus.h	18 May 2006 15:37:05 -0000	1.18
> +++ arch/cobalt/include/bus.h	23 May 2006 17:19:13 -0000
> @@ -531,9 +531,9 @@
>   *
>   * On the MIPS, we just flush the write buffer.
>   */
> -#define	bus_space_barrier(t, h, o, l, f)	\
> -	((void)((void)(t), (void)(h), (void)(o), (void)(l), (void)(f)),	\
> -	 wbflush())
> +#define	bus_space_barrier(t, h, o, l, f)				\
> +	(wbflush(),							\
> +	 (void)((void)(t), (void)(h), (void)(o), (void)(l), (void)(f)))
>  #define	BUS_SPACE_BARRIER_READ	0x01		/* force read barrier */
>  #define	BUS_SPACE_BARRIER_WRITE	0x02		/* force write barrier */
>

-- thorpej