How to define Eclipse external null annotations for parameters in JRE methods

Question

I am trying to annotate the JRE method <T> T[] toArray(T[] a) from java.util.Set using Eclipse's external null annotations . The expected effect should be equivalent to this:

 public interface Set<E> extends Collection<E> {
     ...
     <T> T @NonNull[] toArray(T @NonNull[] a);
     ...
 }

When using Eclipse's Annotate command I can annotate the return type of the method properly (after I selected the T[] and position the cursor before the [ ). However trying to do the same with the parameter fails. Pressing Cmd-1 simply beeps, as does selecting "Annotate" when calling the command from the context menu.

I finally ended up editing the corresponding Set.eea file manually to defined the required annotation, taking care of the proper eea file layout . Ie I changed the annotatedSignature in:

class java/util/Set
toArray
 <T:Ljava/lang/Object;>([TT;)[TT;
 <T:Ljava/lang/Object;>([TT;)[1TT;

to

 <T:Ljava/lang/Object;>([1TT;)[1TT;

This works fine and the annotation is correctly processed by the compiler.

As I can annotate the return type but not a parameter type I am wondering what I am doing wrong. Or is this a limitation of the current Eclipse version?

I am using Eclipse Mars Release (4.5.0, Build id: 20150621-1200) and jdk1.8.0_60.

Answer 1

This is a bug indeed, I just filed https://bugs.eclipse.org/477461 to track this.

This was bug 464081 which got fixed for 4.6 M1 (ie, is available in current builds towards Eclipse Neon) and is currently proposed for 4.5.2 (Mars.2)