think-o: dwarf2 CFA != frame->frame (x86-64)

[Daniel Berlin]

On Tue, 9 Apr 2002, Andrew Cagney wrote:

> 
> >> See:
> >> 
> >> http://sources.redhat.com/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gdb&pr=466
> >> 
> > 
> > 
> > Sorry, this is incorrect.
> > When debug_frame info is present, it is the *only* way used to 
> > retrieve register values.
> > There is no mixture of methods.
>  >
> > Even in my case, either the executable contains .debug_frame info, and we 
> > use it for *all* cases, or it doesn't, and we use it for *no* cases.
> > There is no mixture.
> > 
> > There will never be a mixture of methods (unless you do something illegal, 
> > like attempt to use the .eh_frame section, which contains stack unwinding 
> > only for routines throwing exceptions)
> 
> Please re-read what I wrote.

You said " The problem is that this algorithm assumes that each frame uses 
the same mechanism for locating register values.  With
                       the introduction of dwarf2cfi, this is no longer 
true.  Some frames may use the debug info while others may use the
                       old prologue analysis technique.
"

You are incorrect.
It's an either-or case. Never is their a mixture of methods, unless you do 
something illegal.

> 
> Andrew
>