On 04/23/2013 01:23 PM, Christian Borntraeger wrote:
Lets fix this gcc warning:virtio.c: In function ‘vring_send_buf’: virtio.c:125:35: error: operation on ‘vr->next_idx’ may be undefined [-Werror=sequence-point] Signed-off-by: Christian Borntraeger<borntrae...@de.ibm.com> --- pc-bios/s390-ccw/virtio.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/pc-bios/s390-ccw/virtio.c b/pc-bios/s390-ccw/virtio.c index 79e2941..1968fc6 100644 --- a/pc-bios/s390-ccw/virtio.c +++ b/pc-bios/s390-ccw/virtio.c @@ -122,7 +122,9 @@ static void vring_send_buf(struct vring *vr, void *p, int len, int flags) vr->desc[vr->next_idx].addr = (ulong)p; vr->desc[vr->next_idx].len = len; vr->desc[vr->next_idx].flags = flags& ~VRING_HIDDEN_IS_CHAIN; - vr->desc[vr->next_idx].next = ++vr->next_idx; + vr->desc[vr->next_idx].next = vr->next_idx; + vr->desc[vr->next_idx].next++; + vr->next_idx++;
Hrm. This looks a lot more complicated than it needs to. Why is gcc emitting a warning here? Maybe it only wants braces. Please try whether
.next = ++(vr->next_id); works for you. Alex
