[Checkers] @ReadOnly classes

[Mahmood Ali]

Hi Telmo,

> as of now,
>
> @ReadOnly class ReadOnlyEmpty {}
>
> generates an error, (receiver.invalid), because not every method on  
> Object
> has a @ReadOnly receiver.

The error you are getting is actually due a different issue.  The Sun  
Javac compiler automatically add a constructor tree whose receiver is  
mutable.

In JavariVisitor.visitMethod(), you check whether you have a mutable  
method within a readonly class without checking that the method is a  
constructor.

I assume that the solution is that you allow to have mutable  
constructors within a readonly class, i.e. check method receivers only  
for non-constructors. Please note TreeUtils.isConstructor().

I will try to comment on the rest of your email later.

Regards,
- Mahmood