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Consider the following code: public interface Parent<T> { default void foo(String x) {System.out.println(x);} void foo(T x); @FunctionalInterface interface StringChild extends Parent<String> {}; } Eclipse Neon.1 Release (4.6.1) (org.eclipse.jdt.core_3.12.1.v20160829-0950.jar) does not issue any error or warning on this interface. However javac refuses to compile it with the following message: Parent.java:8: error: interface StringChild inherits abstract and default for foo(String) from types Parent and Parent interface StringChild extends Parent<String> {}; ^ Parent.java:7: error: Unexpected @FunctionalInterface annotation @FunctionalInterface ^ StringChild is not a functional interface no abstract method found in interface StringChild 2 errors I think, this case is covered by JLS 9.4.1.3: https://docs.oracle.com/javase/specs/jls/se8/html/jls-9.html#jls-9.4.1.3 > If an interface I inherits a default method whose signature is override-equivalent with another method inherited by I, then a compile-time error occurs. (This is the case whether the other method is abstract or default.) I think, Eclipse should report an error here as well.
I see this on the latest I build too. Stephan/Sasi, can you confirm if this is indeed a bug on our side? BTW, if I move the abstract foo method to another interface in the hierarchy, then both compilers accept that.
(In reply to comment #1) > I see this on the latest I build too. > > Stephan/Sasi, can you confirm if this is indeed a bug on our side? > > BTW, if I move the abstract foo method to another interface in the hierarchy, > then both compilers accept that. I remember seeing a duplicate sometime ago, that we do not report name clash between default and abstract methods in some cases. Will dig it out, but to answer your question, we do have a bug in this area and I believe it is not a regression (recent or otherwise)
This bug hasn't had any activity in quite some time. Maybe the problem got resolved, was a duplicate of something else, or became less pressing for some reason - or maybe it's still relevant but just hasn't been looked at yet. If you have further information on the current state of the bug, please add it. The information can be, for example, that the problem still occurs, that you still want the feature, that more information is needed, or that the bug is (for whatever reason) no longer relevant. -- The automated Eclipse Genie.
