Re: frame->unwind->this_base()

[Andrew Cagney <ac131313 at redhat dot com>]

> On Tue, Mar 18, 2003 at 12:28:47PM -0500, Andrew Cagney wrote:
>
> > >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.
>
> > A frame with debug info provided by dwarf2.  CFI gives the register 
> > info, location expressions give the variable info, ...
> >
> > What started out as a simple cfi-frame looks like it might need to 
> > evolve into dwarf2-frame ...
>
>
> DWARF-2 debug info does not corelate with CFI info.  For instance, GCC
> will generate DWARF-2 CFI with stabs debug info.  It will also generate
> CFI with no debug info at all, or DWARF-2 info without any CFI (if
> requested).

True dwarf2 debug info or that .eh_frame stuff (i'm curious)?

For stabs to work, it needs FRAME_LOCALS_ADDRESS(); and 
FRAME_LOCALS_ADDRESS() relies on the prologue analyzer (since frame ID 
won't correspond to `frame-base') for the computation of the correct 
value; and that means unwinding the same frame two ways.  Outch.

Andrew