JDK-8221373 : Missing checkcast in void-returning lambda

[B. Blaser]

Hi,

I looked quickly at Liam's example, but I don't think JDK-8203338
introduced any regression in javac.
The target return type is 'void' and the unnecessary 'checkcast' is no
more emitted before a simple 'return'.
But trying the following example:

public abstract class Checkcast {

  interface I<X> {
    X d();
  }

  abstract <X> I<X> c();

  interface R<X> {
    X run();
  }

  void f() {
    R<Void> r = () -> this.<Void>c().d();
    r.run();
  }

  public static void main(String... args) {
    new Checkcast() {
      I<Long> c() {
        return new I<Long>() {
          public Long d() { System.out.println("OK"); return 0L; }
        };
      }
    }.f();
  }
}

the 'checkcast' is still emitted before 'areturn' along with an
unchecked warning and a CCE occurs as expected:

  private java.lang.Void lambda$f$0();
    Code:
       0: aload_0
       1: invokevirtual #7                  // Method c:()LCheckcast$I;
       4: invokeinterface #8,  1            // InterfaceMethod
Checkcast$I.d:()Ljava/lang/Object;
       9: checkcast     #9                  // class java/lang/Void
      12: areturn

Do we agree?

Thanks,
Bernard