RFR: 8261006: 'super' qualified method references cannot occur in a static context

[Srikanth Adayapalam]

On Sun, 6 Jun 2021 02:17:17 GMT, Vicente Romero <vromero at openjdk.org> wrote:

> Please review this PR, currently javac is accepting code like:
> 
> 
> import java.util.function.Supplier;
> 
> public class MethodReferenceInConstructorInvocation {
>     interface Bar {
>         default String getString() { return ""; }
>     }
> 
>     static class Foo implements Bar {
>         public Foo() {  this(Bar.super::getString);  }
>         public Foo(Supplier<String> sString) {}
>     }
> }
> 
> 
> but the spec states in `15.13 Method Reference Expressions`:
> 
> If a method reference expression has the form super :: [TypeArguments] Identifier
> or TypeName . super :: [TypeArguments] Identifier, it is a compile-time error if
> the expression occurs in a static context (§8.1.3).
> 
> and a constructor invocation is a static context. So method references of this form, qualified by `super`, should be rejected by the compiler if they appear in a static context.
> 
> TIA

Also this test case:


import java.util.function.Supplier;

public class X {

    interface Feature {
        default String getString() {
            return "Hello World";
        }
    }

    private static class Broken implements Feature {
        private final String sString;

        public Broken() {
            this(Feature.super.getString());
        }

        public Broken(String sString) {
            this.sString = sString;
        }
    }
}


compiles both with JDK16 and your patch. 

Should we actually compile it ???

-------------

PR: https://git.openjdk.java.net/jdk/pull/4376