Re: [rfc] Wrap addresses in spu-gdb

[Jim Blandy <jimb@codesourcery.com>]

"Ulrich Weigand" <uweigand@de.ibm.com> writes:
> Daniel Jacobowitz wrote:
>> On Wed, Aug 08, 2007 at 08:44:29AM +0200, Markus Deuling wrote:
>> > +  if (target_has_registers && target_has_stack && target_has_memory
>> > +      /* FIXME: Currently needed for dwarf2_read_address to work.  */
>> > +      && type != builtin_type_uint32)
>> 
>> I think that you shouldn't commit a patch with this hack in it.
>> It looks very fragile.
>
> Agreed.  Markus, this is a special hack for the combined PPE/SPE
> debugger, it shouldn't be necessary for the SPU-standalone (and
> mainline) version.
>
> I'll have to look into fixing the underlying issue cleanly when
> merging the combined debugger ...

There seem to be a number of cases where conversions between addresses
and pointers require live values from other registers --- for example,
when a pointer's bits are augmented with bits from some system
register, like a segment base register.  I'd want to work in the
context of real-world examples, but it might be a good idea to
introduce frame_and_pointer_to_address and
frame_and_address_to_pointer, and use them where they make sense.

Using such functions, clipping SPE addresses using the LSLR register
could be carried out in a reasonable way.