[patch] add zero support for x86_64-linux-gnux32 target

[David Holmes]

Hi Severin, Matthias,

On 5/09/2016 10:16 PM, Severin Gehwolf wrote:
> On Mon, 2016-09-05 at 14:03 +0200, Matthias Klose wrote:
>> The attached patch adds support for building zero for the x86_64-
>> linux-gnux32
>> target, having changes in the build system, hotspot and jdk.
>>
>>  - the build system currently only derives the target from
>>    the cpu in PLATFORM_EXTRACT_VARS_FROM_CPU; that is not enough
>>    for the new target, which only differs by the ending of the
>>    triplet. However the $host macro should be available anywhere.
>>
>>  - the hotspot part just handles the new "cpu"
>>
>>  - GensrcX11Wrappers.gmk assumes that there is a black/white
>>    decision about -m32/-m64. The patch works around it.  However
>>    the real patch should be to get these flags from the build
>>    system, and not hardcode itself.
>>
>>  - the sysctl system call is unsupported in the x32 kernel, and
>>    just the include leads to a build error.  From my point of view
>>    the header is not needed. I had successful builds on all other
>>    targets without including it. If you want to keep the include,
>>    then it should be guarded with
>>    #if !(defined(_ILP32) && defined(__x86_64__))
>>
>> Matthias
>
> I've filed this bug for this:
> https://bugs.openjdk.java.net/browse/JDK-8165440

Please note that as a P4 issue this can not be fixed given we have hit RDP1:

http://mail.openjdk.java.net/pipermail/jdk9-dev/2016-August/004777.html

Further this is filed as "bug" but seems to clearly be an enhancement, 
so you would need approval for it to come in post-Feature-Complete.

Please consider if this is something that must be fixed for 9 or can be 
deferred. Otherwise you will need to follow additional approval processes.

Sorry.

David (just the messenger!)

> Unfortunately, I have no way of testing it.
>
> Cheers,
> Severin
>