Re: [Qemu-devel] CMSG_SPACE() causing compile time error on Mac OS X

["Daniel P. Berrange" <berrange@redhat.com>]

On Mon, Jan 18, 2016 at 09:36:08AM -0500, Programmingkid wrote:
> 
> On Jan 18, 2016, at 4:58 AM, Daniel P. Berrange wrote:
> 
> > On Sun, Jan 17, 2016 at 05:23:44PM -0500, Programmingkid wrote:
> >> I was wondering if you had problems compiling QEMU on Mac OS X recently. On my system, the channel-socket.c file causes this error:
> >> 
> >> io/channel-socket.c: In function 'qio_channel_socket_writev':
> >> io/channel-socket.c:497:18: error: variable-sized object may not be initialized
> >>     char control[CMSG_SPACE(sizeof(int) * SOCKET_MAX_FDS)] = { 0 };
> > 
> > Can you try applying this patch:
> > 
> > diff --git a/io/channel-socket.c b/io/channel-socket.c
> > index eaa411f..bc117b1 100644
> > --- a/io/channel-socket.c
> > +++ b/io/channel-socket.c
> > @@ -493,10 +495,12 @@ static ssize_t qio_channel_socket_writev(QIOChannel *ioc,
> >     QIOChannelSocket *sioc = QIO_CHANNEL_SOCKET(ioc);
> >     ssize_t ret;
> >     struct msghdr msg = { NULL, };
> > -    char control[CMSG_SPACE(sizeof(int) * SOCKET_MAX_FDS)] = { 0 };
> > +    char control[CMSG_SPACE(sizeof(int) * SOCKET_MAX_FDS)];
> >     size_t fdsize = sizeof(int) * nfds;
> >     struct cmsghdr *cmsg;
> > 
> > +    memset(control, 0, CMSG_SPACE(sizeof(int) * SOCKET_MAX_FDS));
> > +
> >     msg.msg_iov = (struct iovec *)iov;
> >     msg.msg_iovlen = niov;
> > 
> 
> Your patch solves the problem. Good job!
> 
> Reviewed-By: John Arbuckle <programmingkidx@gmail.com>

Thanks, I'll include this fix in my next PULL request for the io/ layer

Regards,
Daniel
-- 
|: http://berrange.com      -o-    http://www.flickr.com/photos/dberrange/ :|
|: http://libvirt.org              -o-             http://virt-manager.org :|
|: http://autobuild.org       -o-         http://search.cpan.org/~danberr/ :|
|: http://entangle-photo.org       -o-       http://live.gnome.org/gtk-vnc :|