DWARF3 DW_OP_push_object_address - requirement for deferred evaluation?

["Gary Funck" <gary at intrepid dot com>]

Daniel Jacobowitz replied:
> On Tue, Mar 06, 2007 at 07:49:02AM -0800, Gary Funck wrote:
> > I may have a need to use DW_OP_push_object_address.
> > Has any work been done in GDB to support some or all
> > of the DWARF3 functionality?
> 
> Yes - some, but not that particular bit [support for
DW_OP_push_object_address].  > It should not be at all hard.  It's a bit
complicated by the fact
> that GDB sometimes implicitly pushes the object address, though.

Is  decode_locdesc() (in dwarf2read.c) the only routine that
evaluates location descriptions?

Would you please elaborate on your statement that "GDB sometimes
implicitly pushes the object address"?

Given that DW_OP_push_object_address was introduced in DWARF3 to
provide support for objects and data that are described by
"dope vectors", for which their address and other characteristics
such as array bounds are not known until runtime .... is the case
that the evaluation of a descriptor utilizing DW_OP_push_object_address
must be deferred until either the referenced object is instantiated,
or the GDB user makes reference to the object?

If this is the case, it didn't appear to me that GDB currently has
a mechanism for delaying the binding of address information
that is required to reference a variable.  Or perhaps I missed
something?