Re: [Qemu-devel] latest version qemu compile error

[Bruce Rogers]

 >>> On 4/9/2013 at 09:24 PM, "Zhanghaoyu (A)" <address@hidden> wrote: 
>> > I compile the QEMU source download from qemu.git
>> > (http://git.qemu.org/git/qemu.git) on 4-9-2013, errors reported as 
>> > below,
>> > 
>> >  
>> > 
>> > hw/virtio/dataplane/vring.c: In function 'vring_enable_notification':
>> > 
>> > hw/virtio/dataplane/vring.c:72: warning: implicit declaration of 
>> > function 'vring_avail_event'
>> > 
>> > hw/virtio/dataplane/vring.c:72: warning: nested extern declaration of 
>> > 'vring_avail_event'
>> > 
>> > hw/virtio/dataplane/vring.c:72: error: lvalue required as left operand 
>> > of assignment
>> > 
>> > hw/virtio/dataplane/vring.c: In function 'vring_should_notify':
>> > 
>> > hw/virtio/dataplane/vring.c:107: warning: implicit declaration of 
>> > function 'vring_need_event'
>> > 
>> > hw/virtio/dataplane/vring.c:107: warning: nested extern declaration of 
>> > 'vring_need_event'
>> > 
>> > hw/virtio/dataplane/vring.c:107: warning: implicit declaration of 
>> > function 'vring_used_event'
>> > 
>> > hw/virtio/dataplane/vring.c:107: warning: nested extern declaration of 
>> > 'vring_used_event'
>> > 
>> > hw/virtio/dataplane/vring.c: In function 'vring_pop':
>> > 
>> > hw/virtio/dataplane/vring.c:262: error: lvalue required as left 
>> > operand of assignment
>> > 
>> > make: *** [hw/virtio/dataplane/vring.o] Error 1
>> > 
>> >  
>> > 
>> > 'vring_avail_event' and 'vring_need_event' defined in 
>> > /linux-headers/linux/virtio_ring.h, are not available  in vring.c ?
>> 
>> Please send the log of "make V=1".
>> 
>> Paolo
> 
> The log of "make V=1" is identical with that of "make", shown as below,
> 
> hw/virtio/dataplane/vring.c: In function 'vring_enable_notification':
> hw/virtio/dataplane/vring.c:72: warning: implicit declaration of function 
> 'vring_avail_event'
> hw/virtio/dataplane/vring.c:72: warning: nested extern declaration of 
> 'vring_avail_event'
> hw/virtio/dataplane/vring.c:72: error: lvalue required as left operand of 
> assignment
> hw/virtio/dataplane/vring.c: In function 'vring_should_notify':
> hw/virtio/dataplane/vring.c:107: warning: implicit declaration of function 
> 'vring_need_event'
> hw/virtio/dataplane/vring.c:107: warning: nested extern declaration of 
> 'vring_need_event'
> hw/virtio/dataplane/vring.c:107: warning: implicit declaration of function 
> 'vring_used_event'
> hw/virtio/dataplane/vring.c:107: warning: nested extern declaration of 
> 'vring_used_event'
> hw/virtio/dataplane/vring.c: In function 'vring_pop':
> hw/virtio/dataplane/vring.c:262: error: lvalue required as left operand of 
> assignment
> make: *** [hw/virtio/dataplane/vring.o] Error 1
> 
> Thanks,
> Zhang Haoyu

I'm seeing the same failure. It turns out that linux-headers/linux/virtio_ring.h
is not being referenced, but rather /usr/include/linux/virtio_ring.h, which in
my case (and presumably yours as well) is not as recent and doesn't have
vring_avail_event() and vring_used_event().

Bruce