/* Soot - a J*va Optimization Framework
* Copyright (C) 2003 Feng Qian
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
/* ReferenceVariable provides interface for simulating assignments
* in a native method.
* e.g., a = b, can be written by a.isAssigned(b);
* A reference variable is an abstract of a variable rather than a
* representation of an abstract object, the later is represented by
* The simulation formulates the assignment or field assignment of such
* high level variable. It is the resposibility of analyses to get the
* constraints out of such abstract simulation.
* Analyses may use very different representations of points-to, e.g.,
* set constraints, type rules, or points-to graphs. All the analyses
* have to do is to let the variables in the program implement this