RFR: 8167333: Invalid source path info might be used when creating ClassFileStream after CFLH transforms a shared classes in some cases

[David Holmes]

Hi Jiangli,

On 7/10/2016 2:39 PM, Jiangli Zhou wrote:
> Hi,
>
> Please review the following fix for JDK-8167333 <https://bugs.openjdk.java.net/browse/JDK-8167333>:
>
>   webrev: http://cr.openjdk.java.net/~jiangli/8167333/webrev.00/ <http://cr.openjdk.java.net/~jiangli/8167333/webrev.00/>
>
> When a shared class is transformed by a JVMTI agent during initial loading (via CFLH), the VM creates a new ClassFileStream using the transformed class data. The source path info from the class’ associated SharedClassPathEntry is passed as the ‘source’ argument to ClassFileStream. However, some shared classes may not have an associated SharedClassPathEntry and the class_path_index is -1. The VM needs to detect such case and not passing an invalid source path info.

It isn't obvious to me that all callers of CFS::source()/clone_source() 
will handle getting a NULL. Of course I can't tell which of those 
callers may be involved in this particular use-case.

Thanks,
David

> Tested with all existing class data sharing tests.
>
> Thanks,
> Jiangli
>