Re: [Qemu-devel] [RFC PATCH 1/3] virtio-bus : Introduce VirtioBus.

["KONRAD Frédéric" <fred.konrad@greensocs.com>]

On 21/11/2012 15:13, Andreas Färber wrote:
> Am 21.11.2012 15:05, schrieb KONRAD Frédéric:
>> On 21/11/2012 14:04, Andreas Färber wrote:
>>> Am 16.11.2012 16:35, schrieb fred.konrad@greensocs.com:
>>>> +#define DEBUG_VIRTIO_BUS
>>>> +
>>>> +#ifdef DEBUG_VIRTIO_BUS
>>>> +
>>>> +#define DPRINTF(fmt, ...) \
>>>> +do { printf("virtio_bus: " fmt , ## __VA_ARGS__); } while (0)
>>>> +#else
>>>> +#define DPRINTF(fmt, ...) do {} while (0)
>>>> +#endif
>>> We recently had a discussion about bitrotting DPRINTF() statements where
>>> I suggested to use if (0) instead of a no-op macro like this that
>>> doesn't reference fmt and the varargs.
>> I don't understand what you suggested, can you point me to an example ?
> I don't have a link at hand, maybe Evgeny does. It was along the lines of:
>
> #define DEBUG_VIRTIO_BUS 0
>
> #define DPRINTF(fmt, ...) if (DEBUG_VIRTIO_BUS) { \
>          printf("virtio_bus: " fmt , ## __VA_ARGS__); \
>      }
>
> The officially preferred alternative is to use tracepoints. ;)
>
> Cheers,
> Andreas
>
ok, thanks.

Fred