Re: frame->unwind->this_base()

[Daniel Jacobowitz <drow@mvista.com>]

On Tue, Mar 18, 2003 at 12:01:58PM -0500, Andrew Cagney wrote:
> >On Tue, Mar 18, 2003 at 09:54:29AM -0500, Andrew Cagney wrote:
> >
> >>>
> >>>So in this case should we be hooking the get_frame_base() call to
> >>>return the computed DW_AT_frame_base?  [...]  And what happens if we 
> >>don't >have DWARF-2
> >>>information?
> >
> >>
> >>At the start I wrote:
> >>
> >
> >>> For dwarf2 frames, it would return, DW_AT_frame_base.  For prologue 
> >
> >>frames, it would return an attempt at an equivalent value.  Hopefully it 
> >>wouldn't be called for other frame types :-).
> >
> >
> >OK.  I'll make the assumption that the DW_AT_frame_base and the CFA in
> >the dwarf2 unwind information (if both present) will agree.
> 
> That would be a very bad assumption.  They are pratically guarenteed to 
> be different.

Then what do you mean by a "dwarf2 frame"?  I'd assume you meant the
CFA, but it sounds like you mean a frame for which we have dwarf2
.debug_info.

Checking, I do see that they're different... Hum.  We need both
concepts obviously, and I need to reread this dwarf3 draft on my desk.

-- 
Daniel Jacobowitz
MontaVista Software                         Debian GNU/Linux Developer