JDK-8160310: HotSpot cannot be built with GCC 6

[Yasumasa Suenaga]

Hi David, Kim,

I've filed this as JDK-8160310, and uploaded new webrev for discussion.
(Not review request)

   http://cr.openjdk.java.net/~ysuenaga/jdk9-for-gcc6/hotspot.01/


> Some of these appear to be just plain bug fixes, and I wonder why the
> code is working now?  For example, the change at
> src/share/vm/classfile/classLoaderData.cpp:145 seems suspicious.

I analyzed this crash with GDB, and this fix works fine.
Please see hs_err log on JIRA.


> Some of these are just cleanups, like
> src/share/vm/oops/oop.inline.hpp:542, but it's post-FC.

I understood.
But I do not understand well why this cheange works fine.
So I want to discuss about it.
(I uploaded hs_err log to JIRA.)


Thanks,

Yasumasa


On 2016/06/27 12:40, Kim Barrett wrote:
>> On Jun 25, 2016, at 9:57 AM, Yasumasa Suenaga <yasuenag at gmail.com> wrote:
>>
>> Hi all,
>>
>> This review request relates to [1].
>>
>> I've tried to build OpenJDK 9 at Fedora 24 x64.
>> Fedora 24 has GCC 6.1.1, and OpenJDK 9 build was failed.
>>
>> I fixed build error and several issues (VM crash and internal error) as below:
>>
>>  http://cr.openjdk.java.net/~ysuenaga/jdk9-for-gcc6/hotspot/
>
> I've only done a quick skim of the proposed hotspot changes, not a
> proper review.  Just in general, I'd rather review changes in chunks
> that were logically related, which many of these aren't.  (Needed to
> build and run with some new compiler doesn't make them related for
> review purposes.)  And please provide some context.  Reviewers
> shouldn't have to guess what problem is being solved by a given
> change. Some of these still seem mysterious to me, even with the link
> to build failures and crash dumps.
>
> Some specific issues:
>
> A couple of these were recently addressed by JDK-8157758.
>
> Some of these are C++11 or later changes tripping up a code base
> written for C++98/03.  A few months ago a change was made to
> explicitly use -std=gnu++98 for exactly this reason (see JDK-8151841),
> but that seems to have gotten lost in the transition to the new build
> system (see JDK-8156980).  I would prefer that got fixed and these
> kinds of issues be deferred to a future modernization project, where
> some of them might involve something more principled than adding some
> workaround casts, for example. (We've been doing string/identifier
> whitespace separation for a while, though; I'd be fine with those,
> other than being post-FC.)
>
> Some of these appear to be just plain bug fixes, and I wonder why the
> code is working now?  For example, the change at
> src/share/vm/classfile/classLoaderData.cpp:145 seems suspicious.
>
> Some of these are just cleanups, like
> src/share/vm/oops/oop.inline.hpp:542, but it's post-FC.
>
>> Does someone work for it?
>> If no one works for it, I will file it to JBS and will send review request.
>
> Certainly there should be CRs filed for these; the enhancements so
> they don't get lost, and the crashes because they probably indicate
> real bugs.
>
>> For jdk repos, I've sent review request [2].
>>
>>
>> Thanks,
>>
>> Yasumasa
>>
>>
>> [1] http://mail.openjdk.java.net/pipermail/jdk9-dev/2016-June/004494.html
>> [2] http://mail.openjdk.java.net/pipermail/2d-dev/2016-June/007081.html
>
>