Virtual Call Resolution does not work correctly for private methods

[Michael Reif]

ProjectLike's virtualCall resolution does not work in the following code evolution scenario. The JVM runs this code (please see the attached files. B has a main).

Class Structure

class A {
   protected void method(){\* do  something*\}
}

class B extends A {
   private void method(){/* do something*/}

  public static void main(String ... args) {
    var B = new B();
    b.method(); // this is an INVOKEVIRTUAL
  }
}

Problem: b.method is resolved to A.method when an invokevirtual is used.

sbt console code leading to this error:

val file = new java.io.File(dir)
val project = org.opalj.br.analyses.Project(file)
val methods = project.allMethodsWithBody
val main = methods.filter(_.name =="main")
val body = main.body.get
val invoke = body.collectFirst{
   case x @ INVOKEVIRTUAL(org.opalj.br.ObjectType("B"),"m", _) => x
}.get
val results = project.virtualCall("", invoke)

OUTPUT: results: scala.collection.Set[org.opalj.br.Method] = Set(protected void m())

The respective classfiles are attached. "StrangeCallCreator.scala" is the DSL script that engineered these classes.

[Michael Reif]

To address this issue, ProjectLike.virtualCall also needs to the caller's class type. I don't see any other way. Does anybody has another idea?

[florian_kuebler]

Since Java 11, the JVM spec changed the method selection semantics, s.t. it also considers private methods on invokevirtual. Thus, the example can also occur without evolution.