Re: [RFA/RFC] dwarf2-frame read_reg

[Michael Snyder <msnyder@redhat.com>]

Jim Blandy wrote:
> On 4/11/06, Michael Snyder <msnyder@redhat.com> wrote:
> 
>>I want you guys to vett this change.  I was getting wrong results
>>on a target where sizeof (SP) != sizeof (void *).  The local func
>>read_reg was calling extract_unsigned_integer with the wrong size.
> 
> 
> Well, extract_typed_address requires the type of the register to be
> some sort of pointer.  read_reg is given as a callback to the Dwarf
> expression evaluator in dwarf2expr.c, so it could be handed any
> register at all.
> 
> How about unpack_long (buf, register_type (gdbarch, regnum))? 
> Definitely regression-test this on several platforms...
> 

Hmmm... extract_typed_address calls POINTER_TO_ADDRESS, which
seems more likely to "do the right thing".

How about this?

   if (TYPE_CODE (register_type (gdbarch, regnum)) == TYPE_CODE_PTR)
     return extract_typed_address (buf, register_type (gdbarch, regnum));
   else
     return extract_typed_address (buf, builtin_type_void_data_ptr);

(I am assuming that a register_type is unlikely to be TYPE_CODE_REF)