Re: frame->unwind->this_base()

Daniel Jacobowitz
2003-03-18T17:11:27Z

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.