[ovs-dev] [PATCH v4] packets: Use packet metadata initialization function instead of macro.

[Ben Pfaff]

On Fri, Mar 21, 2014 at 10:53:35AM -0700, Gurucharan Shetty wrote:
> On Fri, Mar 21, 2014 at 9:47 AM, Ben Pfaff <blp at nicira.com> wrote:
> > On Fri, Mar 21, 2014 at 09:49:17AM -0700, Jarno Rajahalme wrote:
> >> IMO this would better match the macro, can you try this one instead:
> >>
> >> static inline struct pkt_metadata pkt_metadata_from_flow(const struct flow *flow)
> >> {
> >>     struct pkt_metadata md;
> >>
> >>     md.tunnel = flow->tunnel;
> >>     md.skb_priority = flow->skb_priority;
> >>     md.pkt_mark = flow->pkt_mark;
> >>     md.in_port = flow->in_port;
> >>
> >>     return md;
> >> }
> >>
> >> I did not try this myself, hopefully no typos above. If this works, then the changes in packets.c are not necessary, and both call sites change to something like:
> >>
> >> > -            struct pkt_metadata md = PKT_METADATA_INITIALIZER_FLOW(&flow);
> >> > +            struct pkt_metadata md = pkt_metadata_from_flow(&flow);
> >
> > Old compilers generated bad code for struct returns, so it might be a
> > good idea to look at the generated code to make sure it's sensible.
> struct returns does not seem to be a problem for visual studio.

OK.

(By the way, by "bad code" here, I meant code that performs badly, not
incorrect code.)