From: Luis Machado <luis.machado@linaro.org>
To: Shahab Vahedi <shahab.vahedi@gmail.com>
Cc: Christian Biesinger <cbiesinger@google.com>,
Shahab Vahedi <Shahab.Vahedi@synopsys.com>,
"gdb-patches@sourceware.org" <gdb-patches@sourceware.org>,
Claudiu Zissulescu <Claudiu.Zissulescu@synopsys.com>,
Francois Bedard <Francois.Bedard@synopsys.com>,
Andrew Burgess <andrew.burgess@embecosm.com>
Subject: Re: [Regression] [PATCH] Do not print empty-group regs when printing general ones
Date: Fri, 28 Feb 2020 13:51:00 -0000 [thread overview]
Message-ID: <51718427-72e2-ce12-7181-26ec9b38d947@linaro.org> (raw)
In-Reply-To: <20200228133618.GA3269@gmail.com>
On 2/28/20 10:36 AM, Shahab Vahedi wrote:
> On Fri, Feb 28, 2020 at 10:31:26AM -0300, Luis Machado wrote:
>>
>>
>> On 2/28/20 10:22 AM, Christian Biesinger wrote:
>>> On Fri, Feb 28, 2020 at 7:08 AM Luis Machado <luis.machado@linaro.org> wrote:
>>>>
>>>> On 1/31/20 7:34 AM, Shahab Vahedi wrote:
>>>>> This patch was reviewed once (as OK):
>>>>> https://sourceware.org/ml/gdb-patches/2020-01/msg00613.html
>>>>>
>>>>> Could someone review/merge it?
>>>>>
>>>>>
>>>>> Cheers,
>>>>> Shahab
>>>>>
>>>>
>>>> FTR, this has broken general register printing for ARM/AArch64. Now
>>>> "info reg" shows nothing.
>>>>
>>>> Given there are already remote stubs, probes and gdbservers running out
>>>> there, this is an undesirable change to have.
>>>>
>>>> I had an IRC chat with Christian and he pointed me at some documentation
>>>> stating empty-group registers should not be printed, but i think this is
>>>> a case where the implementation has diverged from the documentation.
>>>>
>>>> https://sourceware.org/gdb/current/onlinedocs/gdb/Target-Description-Format.html#Target-Description-Format
>>>>
>>>> We could probably patch up any non-standard target description XML's
>>>> from now on, but the existing behavior may have to be preserved.
>>>
>>> Most targets under features/ do not specify group="general" in their
>>> XML files for anything (only S/390 does); it seems like that should
>>> maybe be fixed either way?
>>
>> I agree.
>
> The documentation [1] says:
> If no group is specified, GDB will not display the register in info registers
>
> [1]
> https://sourceware.org/gdb/onlinedocs/gdb/Target-Description-Format.html#Target-Description-Format
>
That's valid, but unfortunately it doesn't change the fact the existing
code is breaking backwards compatibility with the installed base.
As we discussed on IRC, this is code put together in early 2007 and
hasn't been touched since, apart from a small change in 2017 to cope
with arbitrary group strings. Plus we have plenty of existing target
descriptions that do not honor explicitly setting a register group.
With that said, i think the documentation would have a lower priority in
this regard. We should fix the existing target descriptions to be more
strict with the group names, but the old behavior would have to be
honored IMO.
next prev parent reply other threads:[~2020-02-28 13:51 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-20 17:29 Shahab Vahedi
2020-01-20 23:04 ` Andrew Burgess
2020-01-31 10:38 ` [PING] " Shahab Vahedi
2020-02-28 13:08 ` [Regression] " Luis Machado
2020-02-28 13:22 ` Christian Biesinger via gdb-patches
2020-02-28 13:32 ` Luis Machado
2020-02-28 13:36 ` Shahab Vahedi
2020-02-28 13:51 ` Luis Machado [this message]
2020-02-28 14:08 ` Shahab Vahedi
2020-02-28 14:11 ` Christian Biesinger via gdb-patches
2020-02-28 14:15 ` Shahab Vahedi
2020-03-04 13:17 ` Luis Machado
2020-03-04 15:21 ` Shahab Vahedi
2020-03-04 16:14 ` Luis Machado
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