Re: [PATCH, RFC] Add support for choosing disassembler cpu in GDB for POWER.

["Ulrich Weigand" <uweigand@de.ibm.com>]

Peter Bergner wrote:

> gdb/
> 	* gdbarch.sh (target_disassemble_init): New.
> 	* gdbarch.c: Regenerate.
> 	* gdbarch.h: Likewise.
> 	* disasm.c (gdb_disassemble_info): Call gdbarch_target_disassemble_init.
>         * rs6000-tdep.c: Include "opcode/ppc.h".
>         (gdb_disassembler_cpu): New static declaration.
>         (prospective_cpu): Likewise.
>         (gdb_rs6000_init_disassembly): New function.
>         (set_disassembler_cpu): Likewise.
>         (show_disassembler_cpu): Likewise.
> 	(rs6000_gdbarch_init): Setup callback for gdb_rs6000_init_disassembly.
>         (_initialize_rs6000_tdep): Initialize gdb_disassembler_cpu and
>         target_init_disassembly.  Setup callbacks for set_disassembler_cpu()
>         and show_disassembler_cpu().

I like this a lot better than the original patch :-)

Still some comments:

> @@ -785,6 +785,8 @@ gdb_disassemble_info (struct gdbarch *gdbarch, struct ui_file *file)
>    di.endian = gdbarch_byte_order (gdbarch);
>    di.endian_code = gdbarch_byte_order_for_code (gdbarch);
>    di.application_data = gdbarch;
> +  if (gdbarch_target_disassemble_init_p (gdbarch))
> +    gdbarch_target_disassemble_init (gdbarch, &di);
>    disassemble_init_for_target (&di);
>    return di;

There's a second use of disassemble_init_for_target, which probably needs
the same treatment.  In fact, maybe the nicest way would be to call the
callback "gdbarch_disassemble_init_for_target", with a default of simply
disassemble_init_for_target, but which targets can override to do extra
stuff before (or after) calling disassemble_init_for_target in there.
GDB common code would then just call gdbarch_disassemble_init_for_target
everywhere it currently calls disassemble_init_for_target.

> +  gdb_disassembler_cpu = strdup (PPC_DEFAULT_CPU",any");

Why do we have to know about this here in GDB?  Can't the GDB default just
be the empty (or NULL) string, and then opcodes does the defaulting
(as it does today)?

Bye,
Ulrich

-- 
  Dr. Ulrich Weigand
  GNU/Linux compilers and toolchain
  Ulrich.Weigand@de.ibm.com