Review Request: JDK-8185148: [MVT] Class.java's isValueClass causes all non-MVT enabled JVM executions to have an InstanceKlass created for __Value reference

[Karen Kinnear]

Looks good - thank you very much Mandy for jumping in on that.

thanks,
Karen

> On Jul 28, 2017, at 9:39 AM, Tobias Hartmann <tobias.hartmann at oracle.com> wrote:
> 
> Hi Mandy,
> 
> this looks good to me! I tested this on top of my fix for 8185453 and all tests pass.
> 
> Thanks,
> Tobias
> 
> On 28.07.2017 06:56, Mandy Chung wrote:
>> A class referencing java.lang.__Value would fail verification when value type is not enabled.  Class::isValueType and MinimalValueTypes_1_0::getValueType both references java.lang.__Value but they may be loaded when value type is not enabled.  VerifyError that Tobias has ran into [1] is related to this issue.
>> 
>> A simple fix is to refactor the reference to java.lang.__Value in a separate class that will only be loaded when -XX:+EnableMVT and —XX:+EnableValhalla is set.  We may look into a cleaner fix in the future.
>> 
>> Webrev:
>>  http://cr.openjdk.java.net/~mchung/valhalla/webrevs/8185148/webrev.00/index.html
>> 
>> Mandy
>> [1] http://mail.openjdk.java.net/pipermail/valhalla-dev/2017-July/003007.html
>>