Re: [Qemu-devel] [RFC v2 2/5] vmstate: add VMS_NONE

["Michael S. Tsirkin" <mst@redhat.com>]

On Mon, Mar 24, 2014 at 05:07:39PM +0000, Dr. David Alan Gilbert wrote:
> * Michael S. Tsirkin (mst@redhat.com) wrote:
> > The element with this flags value is skipped.
> > 
> > Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
> > ---
> >  include/migration/vmstate.h | 1 +
> >  vmstate.c                   | 4 +++-
> >  2 files changed, 4 insertions(+), 1 deletion(-)
> > 
> > diff --git a/include/migration/vmstate.h b/include/migration/vmstate.h
> > index e7e1705..3a1587e 100644
> > --- a/include/migration/vmstate.h
> > +++ b/include/migration/vmstate.h
> > @@ -88,6 +88,7 @@ struct VMStateInfo {
> >  };
> >  
> >  enum VMStateFlags {
> > +    VMS_NONE             = 0x000,
> >      VMS_SINGLE           = 0x001,
> >      VMS_POINTER          = 0x002,
> >      VMS_ARRAY            = 0x004,
> 
> I think this would be simpler if you just gave it it's own
> bit, the next patch already makes the mask more complicated.
> 
> However, do you need it?  Why not just declare a VMS_ARRAY with field->num=0 ?
> 
> Dave

Good idea, I'll do that.

> > diff --git a/vmstate.c b/vmstate.c
> > index 18b3732..fe53735 100644
> > --- a/vmstate.c
> > +++ b/vmstate.c
> > @@ -13,7 +13,9 @@ static int vmstate_n_elems(void *opaque, VMStateField *field)
> >  {
> >      int n_elems = 1;
> >  
> > -    if (field->flags & VMS_ARRAY) {
> > +    if (!(field->flags & ~VMS_NONE)) {
> > +        n_elems = 0;
> > +    } else if (field->flags & VMS_ARRAY) {
> >          n_elems = field->num;
> >      } else if (field->flags & VMS_VARRAY_INT32) {
> >          n_elems = *(int32_t *)(opaque+field->num_offset);
> > -- 
> > MST
> > 
> > 
> --
> Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK