[23] super reference disallowed in the context of a field access

[jarthana]

Here's the testcase:

public class X {
	class Nested extends X1 {
		X1 xy;
		class DeeplyNested extends NestedInX1 {
			DeeplyNested(float f) {
				Nested.super.x1.super(); // Error here
			}
		}
	}
}
class X1 {
	X1 x1;
	class NestedInX1 {}
}

The error reported is Cannot use 'Nested.super' in an early construction context (except in a simple field assignment)
I don't really know the intricacies here and Javac allows this code.

Copying @mpalat and @stephan-herrmann

[jarthana]

I don't know if this is related, but the following code is rejected too:

public class X {
	class Nested {
		Nested(Object o) {}
	}
	class AnotherNested extends Nested {
		AnotherNested() {
			super(new Object() { // Cannot instantiate class new Object(){} in an early construction context of class X.AnotherNested
			});
		}
	}
}

[jarthana]

Here's another variant:

    Y(int a) {
        X.field = new Y() {
            public int foo() {
                return this.a;
            }
        }.foo();
        this();
    }

[stephan-herrmann]

@jarthana Which field should this.a point to?
Somehow you're not telling the full story of that snippet.

[jarthana]

@jarthana Which field should this.a point to? Somehow you're not telling the full story of that snippet.

Yeah, I was just playing around and was too eager to report. Let me get back on this.

[stephan-herrmann]

The error reported is Cannot use 'Nested.super' in an early construction context (except in a simple field assignment)

The naked eye doesn't even see any early construction context (and --enable-preview is not needed for javac). So this part looks buggy ...

I don't really know the intricacies here and Javac allows this code.

"intricacies" is a good word here :)
It took my quite some time to figure out what this program is trying to say.

This version seems to be equivalent, and is accepted by ecj:

	x1.super();

(qualifying the inherited field is not necessary).

Read: when going from DeeplyNested to its super NestedInX1 we need one additional enclosing instance which is provided as x1. Wow!

[stephan-herrmann]

 public class X {
	class Nested {
		Nested(Object o) {}
	}
	class AnotherNested extends Nested {
		AnotherNested() {
			super(new Object() { // Cannot instantiate class new Object(){} in an early construction context of class X.AnotherNested
			});
		}
	}
}

For this I filed #3132