Re: [PATCH v2] gdb/i387-tdep.c: Avoid warning for "-Werror=strict-overflow"

Chen Gang S
2015-01-09T21:50:22Z

At present, for gcc version 5.0.0 20150109 (experimental) (GCC), can not
find this warning again. So this thread can be ended. If it will appear
again in the future, I shall analyze it again only within gcc wide.

And sorry for having delayed a long time for it.

Thanks.

On 11/10/14 09:45, Chen Gang wrote:
> Hello Iain:
>
> Is this bug still alive (I joined in bug 63510)? If it is, I shall try
> to fix it within this month (within 2014-11-30).
>
> At present, its status is:
>
> - gcc members think that what compiler has done is correct, but need
> improve its report line number:
>
> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63510
>
> - gdb members might think what compiler has done is incorrect (need not
> report warning).
>
> - for me, I agree with gcc members' opinion, and shall try to improve
> its report line number.
>
>
> Welcome any ideas, suggestions and completions, in time.
>
> Thanks.
>
> On 10/13/14 7:45, Chen Gang wrote:
>> Oh, really it is. Originally, I skipped it (do not know it should be as an issue, too). Also sorry for my poor English: misunderstand what you said (this patch can still continue, although gcc 5 has another issue).
>>
>> And next, I shall try to fix it, based on what bugzilla has done. But excuse me, I have no enough time resource on it, so maybe can not finish within this month (try to finish within next month) .
>>
>> Thanks
>>
>> Send from Lenovo A788t.
>>
>>
>> Iain Buclaw <ibuclaw@gdcproject.org> wrote:
>>
>> On 12 October 2014 15:47, Chen Gang <gang.chen.5i5j@gmail.com> wrote:
>>> On 10/12/14 22:13, Iain Buclaw wrote:
>>>> On 12 October 2014 14:28, Chen Gang <gang.chen.5i5j@gmail.com> wrote:
>>>>> gdb requires "-Werror", and I387_ST0_REGNUM (tdep) is 'variable', then
>>>>> compiler can think that I387_ST0_REGNUM (tdep) may be a large number,
>>>>> which may cause issue, so report warning.
>>>>>
>>>>> Need fix this warning, and still keep the code clear enough for readers.
>>>>> The related warning under Darwin with gnu built gcc:
>>>>>
>>>>
>>>> I had noted the same on GCC 5.0.0 development, found that the line
>>>> number in the warning was wrong and raised a bug
>>>> (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63510), just didn't get
>>>> round to submitting a patch for gdb.
>>>>
>>>
>>> But for me, what compiler has done is correct: "-Werror=strict-overflow"
>>> need include "(X + c) >= X" for signed overflow. And our case matches
>>> this case:
>>>
>>
>> The compiler has done right, but that still doesn't stop the reported
>> line number being wrong.
>>
>> -- Iain.
>>
>
> Thanks.
>

--
Chen Gang

Open, share, and attitude like air, water, and life which God blessed

--
Chen Gang

Open, share, and attitude like air, water, and life which God blessed