JDK-8145489 NPE in javac during Attribute stage. Sequel

[Srikanth]

[This mail is dated 13th May, but showed up in my inbox today.]

Hi Plizga,

I suspect the problem you faced is the same as
https://bugs.openjdk.java.net/browse/JDK-8145489

which is addressed via

http://hg.openjdk.java.net/jdk9/dev/langtools/rev/2d1a6b746310

Perhaps you can check if the problem shows up on JDK9 tip

Thanks!
Srikanth.

On Friday 13 May 2016 10:10 AM, Plizga Vladimir wrote:
> Hello!
>
> I'm the initiator of issue https://bugs.openjdk.java.net/browse/JDK-8145489 "NullPointerException while compiling certain annotations". The issue was closed because the assignee (Fairoz Matte) unfortunately couldn't reproduce it and I had no additional info by that moment.
> But the bug is still actual for our project  and recently I researched it in detail. I've sent the results by email to Fairoz a week ago but I didn't receive any answer. Hope you can help me.
>
> 1. I've significantly simplified the code snippet to reproduce the bug. Now it consists of just 3 short Java files located in 'mypackage' package:
>
> <File PackageAnnotation.java>
> package mypackage;
> public @interface PackageAnnotation {
>    Class<?> classyAnnotationMember();
> }
> </File PackageAnnotation.java>
>
> <File MyClass.java>
> package mypackage;
> public class MyClass {
>    public class MyInnerClass { }
> }
> </File MyClass.java>
>
> <File package-info.java>
> @PackageAnnotation(classyAnnotationMember = MyClass.MyInnerClass.class)
> package mypackage;
> </File package-info.java>
>
> An attempt to compile this files with javac 1.8.0_92 will end up with NullPointerException during Attribute stage (see the stacktrace in JDK-8145489).
>
> 2. The source of the error is condition “!env.next.tree.hasTag(REFERENCE)” in com/sun/tools/javac/comp/Attr.java:3335 line that was added in JDK 1.8.
> AFAIU there is no enclosing environment for some class-type members of annotations at the topmost (package) level. That's why "env.next == null" and "env.next.tree" fails with NPE.
>
> 3. As a temporal workaround (in order to proceed with my current task) I’ve fixed the problem in 1.8.0_92 compiler’s source code by prepending the new condition with a naive checking for enclosing environment nullness:
>     (env.next != null && !env.next.tree.hasTag(REFERENCE))
> and rebuilt the compiler. This fix has not affected the amount of successfully passed tests run with jtreg and has allowed me to proceed. I believe Oracle engineers would find a truly proper way to fix it:)
>
>
> I hope this information would be enough to reproduce and fix the bug. If not, you are welcome to request anything else.
>
> Thanks,
> Vladimir Plizga