// inherit.beh -- Inheritance backlinks construction
// $Id: inherit.beh,v 1.1 1998/03/11 22:28:04 dougo Exp $

Program {
  /** Mark classes between "*visitors*" and "*endvisitors*" as visitors. */
  private void markVisitors()
    to { BeginVisitors, EndVisitors, ClassDef }
  {
    (@ boolean visitor = false; @)
    before BeginVisitors (@ visitor = true; @)
    before EndVisitors (@ visitor = false; @)
    before ClassDef (@ if (visitor) host.markVisitor(); @)
  }
}

Program {
  /** Set inheritance links for alternates of an alternation class.
      Set the parent for all visitors to the universal visitor class. */
  private void setInheritanceLinks() to Subclass {
    (@ ClassName parent_name; @)
    before ClassDef (@
      parent_name = host.get_classname();
      if (host.isVisitor() && !parent_name.equals(Program.univis)) {
	host.set_parent(Program.univis);
      }
    @)
    before Subclass (@
      ClassName clname = host.get_classname();
      ClassDef def = Program.prog.findClassDef(clname);
      if (def == null) {
	// should throw an exception...
	System.err.println("Error: no such class \"" + clname + "\"");
      } else {
	def.set_parent(parent_name);
      }
    @)
  }
}

ClassDef {
  /** Set or add a parent to a class or interface. */
  void set_parent(ClassName parent_name) to Superclass_Commalist {
    (@ ClassName child_name; boolean isInterface; @)
    before ClassDef (@
      child_name = host.get_classname();
      isInterface = host.isInterface();
    @)
    (@ static Superclass univis
	  = Superclass.parse(Program.univis.toString()); @)
    (@ Superclass_Commalist parents; @)
    before Superclass_Commalist (@ parents = host; @)
    after ClassParents (@
      if (parents == null || parents.contains(univis)) {
	parents = new Superclass_Commalist();
	host.set_superclasses(new Superclasses(
				  new ExtendsKeywordWithoutStars(),
				  parents));
      }
      Superclass newparent = Superclass.parse(parent_name.toString());
      if (isInterface || parents.isEmpty()) {
	parents.addElement(newparent);
      } else if (!(newparent.equals(Program.univis)
		   || parents.contains(newparent))) {
	System.err.println(
 "Error: class " + child_name + " cannot have more than one parent: " +
  parent_name + " (previous parent: " + parents + ")");
      }
    @)
  }
}