On Thu, 26 Nov 2020, Peter Maydell wrote:
> On Thu, 26 Nov 2020 at 11:30, <marcandre.lur...@redhat.com> wrote:
> >
> > From: Marc-André Lureau <marcandre.lur...@redhat.com>
> >
> > QEMU requires Clang or GCC, that define and support __GNUC__ extensions
> >
> > Signed-off-by: Marc-André Lureau <marcandre.lur...@redhat.com>
> > ---
> > include/hw/xen/interface/io/ring.h | 9 ---------
> > 1 file changed, 9 deletions(-)
>
> >From QEMU's POV this change is good, but this header seems to have
> originally been an import from the Xen public headers -- are we
> happy to diverge from that original or do we prefer to stay as
> close as possible to the upstream header? Cc'ing the Xen maintainers
> for their opinion.
Small divergences are not a problem. I think this is OK.
> > diff --git a/include/hw/xen/interface/io/ring.h
> > b/include/hw/xen/interface/io/ring.h
> > index 5d048b335c..115705f3f4 100644
> > --- a/include/hw/xen/interface/io/ring.h
> > +++ b/include/hw/xen/interface/io/ring.h
> > @@ -206,21 +206,12 @@ typedef struct __name##_back_ring __name##_back_ring_t
> > #define RING_HAS_UNCONSUMED_RESPONSES(_r) \
> > ((_r)->sring->rsp_prod - (_r)->rsp_cons)
> >
> > -#ifdef __GNUC__
> > #define RING_HAS_UNCONSUMED_REQUESTS(_r) ({ \
> > unsigned int req = (_r)->sring->req_prod - (_r)->req_cons; \
> > unsigned int rsp = RING_SIZE(_r) - \
> > ((_r)->req_cons - (_r)->rsp_prod_pvt); \
> > req < rsp ? req : rsp; \
> > })
> > -#else
> > -/* Same as above, but without the nice GCC ({ ... }) syntax. */
> > -#define RING_HAS_UNCONSUMED_REQUESTS(_r) \
> > - ((((_r)->sring->req_prod - (_r)->req_cons) < \
> > - (RING_SIZE(_r) - ((_r)->req_cons - (_r)->rsp_prod_pvt))) ? \
> > - ((_r)->sring->req_prod - (_r)->req_cons) : \
> > - (RING_SIZE(_r) - ((_r)->req_cons - (_r)->rsp_prod_pvt)))
> > -#endif
> >
> > /* Direct access to individual ring elements, by index. */
> > #define RING_GET_REQUEST(_r, _idx) \
