Queries about JDK-8035890

[Jan Lahoda]

Thanks a lot for explanations, Alex! I've filled a separate bug for the 
problem with RuntimeInvisibleAnnotations in anonymous innerclass: 
JDK-8037348.

Jan

On 03/13/2014 07:12 PM, Alex Buckley wrote:
> On 3/13/2014 5:38 AM, Jan Lahoda wrote:
>> I have two questions on JDK-8035890 - any insights on them are very
>> welcome.
>>
>> 1. Consider this source code:
>> ---
>> public class AnnotAfterTypeParams {
>>      public <T> @Decl int foo() { return 0; }
>> }
>> @interface Decl { }
>> ---
>>
>> javac currently accepts this code - is that correct? (I could not find a
>> point in the specification to support this.)
>
> javac is correct.
>
> Early drafts of JLS8 did not allow annotations after the type parameter
> section of a method declaration, but javac and ecj did. This was
> discussed in the thread "type annotations on generic method return type"
> [1] and fortunately JLS8 (section 8.4) was corrected in time for the
> Final Release of JSR 337. [If you're not using JLS8 from that Final
> Release, now is the time to delete your PDF and get it.]
>
> [1]
> http://mail.openjdk.java.net/pipermail/type-annotations-spec-comments/2014-February/thread.html
>
>
>> 2. Consider this source code:
>> ---
>> import java.lang.annotation.*;
>> public class AnnotCopiedToAnonymous {
>>      private Object o = new @Annot Object() { };
>> }
>> @Target({ElementType.TYPE, ElementType.TYPE_USE})
>> @interface Annot { }
>> ---
>>
>> The generated anonymous innerclass (AnnotCopiedToAnonymous$1) has the
>> Annot annotation as a declaration annotation in its
>> RuntimeInvisibleAnnotations in addition to having it in its
>> RuntimeInvisibleTypeAnnotations with a supertype target. Is it intended
>> to have the annotation as a declaration annotation?
>
> It is not intended.
>
> The existence of the Runtime[In]VisibleAnnotations attribute in the
> anonymous class file was discussed in the thread "Desugaring of
> anonymous classes" [2]. This led to a bug report on type-annotations-dev
> [3]. That said, the second case in the reported bug JDK-8023682 has only
> @Target(ElementType.TYPE) - no TYPE_USE as in your example. Still, the
> intent from [2] was to _not_ generate Runtime[In]VisibleAnnotations - I
> believe ecj does not generate it.
>
> (A long time ago [4], I said it was OK to generate it, but that was
> before applicability was clarified.)
>
> [2]
> http://mail.openjdk.java.net/pipermail/type-annotations-spec-experts/2013-August/thread.html
>
>
> [3]
> http://mail.openjdk.java.net/pipermail/type-annotations-dev/2013-August/001209.html
>
>
> [4]
> http://mail.openjdk.java.net/pipermail/type-annotations-spec-experts/2013-February/000063.html
>
>
> Alex