Consider the following class:

final class CapturingLambda {
    Runnable withAnonymousRunnableInside() {
        return () -> {
            Runnable r = new Runnable() {
                @Override
                public void run() {
                }
            };
            r.run();
        };
    }

    Runnable withLocalClassInside() {
        return () -> {
            class Local {}
            new Local();
        };
    }
}

The lambdas here are not using the instance of an outer CapturingLambda object, so I expect that they should not capture it. However, this is not the case. Lambda synthetic methods are non-static, and CapturingLambda this object is passed to invokedynamic:

         0: aload_0
         1: invokedynamic #7, 0 // InvokeDynamic #0:run:(LCapturingLambda;)Ljava/lang/Runnable;

This prevents from creating a singleton lambda instance and unnecessarily keeps the strong reference to an outer object. I think this could be fixed.

discussed in compiler-dev: https://mail.openjdk.org/pipermail/compiler-dev/2025-November/032133.html