[aspectj-users] execution pointcut and subclassing

["Linton Ye" <lintonye@xxxxxxxxxxxxxxx>]

Hi,

Recently I came across some issues regarding execution pointcut and subclassing, a sample code is as following:

class Shape {
  public void moveBy(int x, int y) {...}
}

class Rectangle extends Shape {
}

class Square extends Rectangle {
  public void moveBy(int x, int y) {...}
}

class Driver {
  public void main(String[] args) {
    System.out.println("[ Shape square = new Square(); square.moveBy(1,1); ]");
    Shape square = new Square();
    square.moveBy(1,1);

    System.out.println("[ Shape rect = new Rectangle(); rect.moveBy(1,1); ]");
    Shape rect = new Rectangle();
    rect.moveBy(1,1);
  }
}

aspect SomeAspect {
  after():execution(* Rectangle.moveBy(..)) {
    System.out.println("exec:Rectangle.moveBy");
  }
  after():execution(* Square.moveBy(..)) {
    System.out.println("exec:Square.moveBy");
  }
  after():execution(* Shape.moveBy(..)) {
    System.out.println("exec:Shape.moveBy");
  }
}

If we run the above example, we will get the following output:

[ Shape square = new Square(); square.moveBy(1,1); ]
exec:Rectangle.moveBy
exec:Square.moveBy
exec:Shape.moveBy

[ Shape rect = new Rectangle(); rect.moveBy(1,1); ]
exec:Shape.moveBy

Notice that, when square.moveBy is called, even moveBy method is not defined in Rectangle class, the pointcut execution(* Rectangle.moveBy(..)) still matches it, however, when rect.moveBy is called, "exec:Rectangle.moveBy" doesn't show up because moveBy method is not overriden in Rectangle. 

I searched on the bugzilla and tried the same program on both AspectJ and ABC compiler and got the same result, so I assume it's not a bug in AspectJ implementation.

The question is, what is the semantics of the method signature in execution pointcut?  I checked the semantics appendix on eclipse.org and got the answer that "the signature is a method signature whose qualifying type is the declaring type of the method".  However, this doesn't seem to explain much - the result is still contradictory.

Thanks,
Linton