On 23/04/13 13:31, Alexander Graf wrote: > 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 > >
I already did that, but I get the same error message. I dont understand why gcc emits that warning, but it does :-(
