RFR: 8232084: HotSpot build failed with GCC 9.2.1

[David Holmes]

On 17/10/2019 12:19 pm, Yasumasa Suenaga wrote:
> On 2019/10/17 9:34, David Holmes wrote:
>> On 17/10/2019 10:07 am, serguei.spitsyn at oracle.com wrote:
>>> Hi Yasumasa,
>>>
>>> It looks good.
>>> One tip:
>>>
>>> + // This code would be warned as "stringop-truncation" by GCC 8 or 
>>> later.
>>> +PRAGMA_DIAG_PUSH
>>> +PRAGMA_STRINGOP_TRUNCATION_IGNORED
>>>         strncpy(buf, str, len);
>>> +PRAGMA_DIAG_POP
>>>
>>>
>>> I'd suggest to place the comment before the line with strncopy().
>>
>> I'd suggest just dropping the comment as it adds nothing, further gcc 
>> 8 is not flagging this use of strncpy.
> 
> The comment is suggested in [1].
> Indeed stringop-truncation warning was not reported by GCC 8, but this 
> option introduced in it,
> and I agree with Ioi to add the comment for other developers why this 
> #pragma is needed.

PRAGMA_STRINGOP_TRUNCATION_IGNORED

seems to pretty clearly state what the issue is to me. But if you want 
to add a comment to make that more clear fine. But don't mention gcc 8 
as it is not relevant to the need for the pragma now.

Thanks,
David

> 
> Yasumasa
> 
> 
> [1] 
> https://mail.openjdk.java.net/pipermail/serviceability-dev/2019-October/029578.html 
> 
> 
>> Otherwise okay.
>>
>> Thanks,
>> David
>>
>>> Not  subject for re-review.
>>>
>>> Thanks,
>>> Serguei
>>>
>>>
>>> On 10/16/19 16:25, Yasumasa Suenaga wrote:
>>>> (Re-send email because I could not send original email to 
>>>> serviceability-dev and hotspot-compiler-dev)
>>>>
>>>> Hi,
>>>>
>>>> We discussed the fix for JDK-8232084 in [1], and I think we should 
>>>> fix it with #pragma.
>>>> I uploaded new webrev. Could you review it?
>>>>
>>>>   JBS: https://bugs.openjdk.java.net/browse/JDK-8232084
>>>>   webrev: http://cr.openjdk.java.net/~ysuenaga/JDK-8232084/webrev.03/
>>>>
>>>> This change has passed the tests on submit repo 
>>>> (mach5-one-ysuenaga-JDK-8232084-1-20191016-1534-5969882).
>>>>
>>>>
>>>> Thanks,
>>>>
>>>> Yasumasa
>>>>
>>>>
>>>> [1] 
>>>> https://mail.openjdk.java.net/pipermail/serviceability-dev/2019-October/029547.html 
>>>>
>>>