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

[Chen Gang <gang.chen.5i5j@gmail.com>]

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