RE: [Bpf] Follow up on "call helper function by address" terminology

[dthaler1968@googlemail.com]

Watson Ladd wrote: 
> On Fri, Apr 5, 2024 at 2:50 PM David Vernet <void@manifault.com> wrote:
> > On Fri, Apr 05, 2024 at 01:10:38PM -0700,
> dthaler1968=40googlemail.com@dmarc.ietf.org wrote:
> > > At IETF 119, we agreed that "by address" should be changed to
> > > something else in the ISA.  The term "legacy ID" was used during the
> > > discussion but Christoph (if I remember right) pointed out that such
> > > IDs are not deprecated per se.  Hence "legacy" may not be the right
> > > word since we use that word with legacy packet access instructions
> > > that are deprecated. We decided to take further discussion to the
> > > list, hence this email.
> > >
> > > We need some term to distinguish them from BTF IDs, so another
> > > alternative might be "non-BTF ID".
> >
> > Non-BTF ID is fine with me. Any objections?
> 
> If something later comes along supplanting BTF it will be the not-BTF not-non-
> BTF thing. This is bad. How about untyped identifiers?

For runtimes that have a way to look up type info from a non-BTF ID, the 
ID is not "untyped" per se.

Other possibilities:
* Classic ID, but "classic" would imply classic BPF
* Index, but that would imply the runtime actually has to implement it as an index 

As such, I think "non-BTF ID" is better than the other possibilities above, and a
future ISA version could always rename it if other things come up in the future
that necessitate a terminology change.

Dave