Re: [PATCH] Fix ptype.exp fail in MIPS

[Pedro Alves <palves at redhat dot com>]

On 05/19/2014 03:51 PM, Doug Evans wrote:
> On Fri, May 16, 2014 at 12:40 AM, Hui Zhu <teawater@gmail.com> wrote:
>> On Fri, May 16, 2014 at 1:53 AM, Pedro Alves <palves@redhat.com> wrote:
>>> On 05/13/2014 05:09 AM, Hui Zhu wrote:
>>>> ptype $pc
>>>> type = int32_t
>>>> (gdb) FAIL: gdb.base/ptype.exp: ptype $pc
>>>> This is because the $pc register in MIPS is set to int but not code_ptr.
>>>> And according to the discussion in
>>>> https://sourceware.org/ml/gdb/2013-06/msg00020.html, the type cannot be
>>>> changed.
>>>
>>> Hmm, that's not what I get from this branch of the discussion:
>>>
>>>  https://sourceware.org/ml/gdb/2013-06/msg00021.html
>>>
>>> --
>>
>> https://sourceware.org/ml/gdb/2013-06/msg00032.html
>> Do you think add ptr64 or $_xx is OK for you to handle this issue?
> 
> IIUC it's not just adding $_xx but changing the type of $pc so that
> ptype.exp will pass as is.
> Is that correct?

Yeah.  As listed at the bottom of that url, $pc would be
changed to be the ABI function pointer width (32-bit pointer),
as a pseudo-register, and $_pc/$rNN would be mapped to the
machine's full 64-bit contents, as an integer.

I'm not certain this is a good idea of not in terms of user
interface.  I know _I_ wouldn't be confused, and I know I have
been confused by $sp/$esp/$rsp on x86 before ($sp is not really
what one would expect if one doesn't know about GDB's special
magic stack pointer register), but I'm not really representative
of a regular gdb user.

-- 
Pedro Alves