Re: [Qemu-devel] [PATCH v4 2/3] libvhost-user: fix -Werror=format= on ppc64

["Philippe Mathieu-Daudé" <philmd@redhat.com>]

Hi Marc-André,

On 5/14/19 12:41 PM, Marc-André Lureau wrote:
> That should fix the following warning:
> 
> /home/pm215/qemu/contrib/libvhost-user/libvhost-user.c: In function
> ‘vu_set_mem_table_exec_postcopy’:
> /home/pm215/qemu/contrib/libvhost-user/libvhost-user.c:666:9: error:
> format ‘%llx’ expects argument of type ‘long long unsigned int’, but
> argument 5 has type ‘__u64’ [-Werror=format=]
>          DPRINT("%s: region %d: Registered userfault for %llx + %llx\n",
>          ^
> /home/pm215/qemu/contrib/libvhost-user/libvhost-user.c:666:9: error:
> format ‘%llx’ expects argument of type ‘long long unsigned int’, but
> argument 6 has type ‘__u64’ [-Werror=format=]
> cc1: all warnings being treated as errors
> 
> Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
> ---
>  contrib/libvhost-user/libvhost-user.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/contrib/libvhost-user/libvhost-user.c b/contrib/libvhost-user/libvhost-user.c
> index 40443a3daa..ab85166b15 100644
> --- a/contrib/libvhost-user/libvhost-user.c
> +++ b/contrib/libvhost-user/libvhost-user.c
> @@ -663,8 +663,10 @@ vu_set_mem_table_exec_postcopy(VuDev *dev, VhostUserMsg *vmsg)
>                       __func__, i);
>              return false;
>          }
> -        DPRINT("%s: region %d: Registered userfault for %llx + %llx\n",
> -                __func__, i, reg_struct.range.start, reg_struct.range.len);
> +        DPRINT("%s: region %d: Registered userfault for %"
> +               PRIu64 " + %" PRIu64 "\n", __func__, i,

I guess you want PRIx64 in both places here.

I'd put the '%' on the next line:

           DPRINT("%s: region %d: Registered userfault for "
                  "%" PRIx64 " + %" PRIx64 "\n", __func__, i,

Using PRIx64:
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>

> +               (uint64_t)reg_struct.range.start,
> +               (uint64_t)reg_struct.range.len);
>          /* Now it's registered we can let the client at it */
>          if (mprotect((void *)(uintptr_t)dev_region->mmap_addr,
>                       dev_region->size + dev_region->mmap_offset,
>