Re: How to handle different sizes of pointers in GDB?

[Iru Cai via Gdb <gdb@sourceware.org>]

Thanks for your help.

On Mon, Aug 19, 2024 at 6:42 PM Luis Machado <luis.machado@arm.com> wrote:

>
> From what I recall, you'll need to make sure your address class is correct
> in DWARF for the
> different pointer types. Assuming that is correct, have you also
> implemented the 3 hooks
> that deal with address classes?
>
> set_gdbarch_address_class_type_flags
> set_gdbarch_address_class_type_flags_to_name
> set_gdbarch_address_class_name_to_type_flags
>
>
Now I'm using set_gdbarch_address_class_type_flags to make the DWARF reader
set the instance_flags of the pointer types, and register a
gdbarch_pointer_to_address method. I can see GDB can call my
pointer_to_address for each pointer, and type->length() is still 8, but I
can get the address class from type->instance_flags() and use it to know
the pointer size.


> Check the s390 code for some reference in gdb/s390-tdep.c
>
> Even with those set correct, gdb can still get confused with pointer sizes
> depending on
> which gdb subsystem is handling it. The type information sometimes gets
> lost when we cross
> some gdb internal boundaries, and then we fallback to the default pointer
> size.
>
> I hope that helps some.
>