Re: [libunwind] suggest adding unw_init_local_accessors

[Mark Young]

As presently implemented, an UNW_ENOINFO error from unw_init_local, unw_init_remote,
or unw_step is a forward-looking statement that the unwinder does not know
how to take the _next_ unwind step. It does not necessarily mean that the
cursor's current frame state data is inaccurate.
--Mark

David Mosberger wrote:
> > > > > > On Mon, 09 Dec 2002 13:52:59 -0800, Mark Young <address@hidden> said:
> > > > > >           
> > > > >         
> > > >       
> > >     
> >   
>
>   Mark> 3) errors originating in ia64_make_proc_info can be returned
>   Mark> by unw_init_local, unw_init_remote, or unw_step. I'd like to
>   Mark> focus recovery for this set of errors in one place by
>   Mark> deferring the call to ia64_make_proc_info into unw_step. I
>   Mark> believe this can be done with no change in functionality by
>   Mark> replacing the ia64_make_proc_info calls in common_init and
>   Mark> update_frame_state with return 0 and inserting the call to
>   Mark> ia64_make_proc_info (and a test of its return value) as the
>   Mark> first thing done in unw_step.
>
> Actually, this one we can't do.  The API requires that after
> unw_init_{local,remote}, the cursor must point to a valid frame.
> Without the unw_step(), this wouldn't be the case.  I don't want to
> change the API because even though it would be easy to make the
> suggested change for ia64, it is not clear whether it could reasonably
> be implemented for other architectures (and I also don't like the idea
> of having an initial cursor value which is meaningless).  Hope that's
> OK.
>
> 	--david

-- 
Mark Young            address@hidden     Tel: 503.526.1661
Staff Engineer         www.model.com      Fax: 503.526.5473
Model Technology, Inc.
10450 SW Nimbus Avenue/Bldg RB, Portland, OR 97223-4347 USA