Java sealed interface permits generic type: gradle complains, eclipse does not

Question

I have three types, A, B, and C, which are defined as follows:

public sealed interface A extends Comparable<A> permits B<?>, C { ...
    
public non-sealed interface B<T> extends A { ...
    
public record C(String s, int i) implements A { ...

Everything compiles and works fine in Eclipse. Now when I run a gradle build, I get an error error: '{' expected at the place of the opening bracket at permits B<?>. When I remove <?>, so that the type definition is as follows (raw type):

public sealed interface A extends Comparable<A> permits B, C { ...

...then gradle doesn't complain and the build is successful. Is this a gradle bug or is the type definition I am using not allowed?

Answer 1

According to the Java Language Specification §8.1.6 the items of the permits type list must be without their type parameters.

So, permits B<?> is incorrect and has to be corrected to permits B.

Please make sure that permits B<?> does not give a compile error and permits B<?> does give a B is a raw type. References to generic type B<T> should be parameterized warning instead, has been reported to Eclipse JDT.