Re: crasher in dwarf2loc.c

[Daniel Jacobowitz <drow at mvista dot com>]

On Thu, Apr 24, 2003 at 05:18:39PM -0700, Michael Snyder wrote:
> Daniel Jacobowitz wrote:
> > 
> > On Tue, Apr 22, 2003 at 05:50:56PM -0700, Michael Snyder wrote:
> > > Hey Daniel,
> > >
> > > I've got a core dump coming from dwarf_expr_frame_base.
> > > First you call get_frame_function, and then you immediately
> > > use its return value.  But get_frame_function can return zero,
> > > so I think you need to check for zero before using it.
> > >
> > > Michael
> > 
> > Just to avoid the crash, you're probably right.
> > 
> > > PS: more details:  get_frame_block returns zero, because
> > > frame_address_in_block returns a pc that is not in any block.
> > >
> > > The crash occurs while running recurse.exp, when we have a
> > > watchpoint on a local variable in an inner frame, and we
> > > continue -- so I don't know the exact context; but I'm
> > > willing to bet that it is trying to evaluate the local
> > > variable after the stack frame has been destroyed.
> > 
> > Huh - we should not even be reaching this code.  I don't quite
> > understand your explanation; what target does this happen?  Can it be
> > reproduced on a simulator, or something of that ilk?
> 
> mumble, mumble...
> 
> [...]
> 
> mumble, mumble, mumble...
> 
> OK, yes.
> 
> But first you have to back out this change: then run recurse.exp.
> If it doesn't crash in your target of choice, try h8300-elf (sim).

Cleaning, cleaning...

Michael, FYI, I'm going to consider this problem moot unless you manage
to reproduce it in the current sources; I can't.  With Andrew's change
it shouldn't happen.


-- 
Daniel Jacobowitz
MontaVista Software                         Debian GNU/Linux Developer