/* Soot - a J*va Optimization Framework
* Copyright (C) 1997-1999 Raja Vallee-Rai
*
* 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.
*/
/*
* Modified by the Sable Research Group and others 1997-1999.
* See the 'credits' file distributed with Soot for the complete list of
* contributors. (Soot is distributed at http://www.sable.mcgill.ca/soot)
*/
package soot;
/** Reference implementation for UnitBox; just
* add a canContainUnit method. */
public abstract class AbstractUnitBox implements UnitBox
{
protected Unit unit;
public abstract boolean canContainUnit(Unit u);
public boolean isBranchTarget()
{
return true;
}
public void setUnit(Unit unit)
{
if(!canContainUnit(unit))
throw new RuntimeException("attempting to put invalid unit in UnitBox");
// Remove this from set of back pointers.
if(this.unit != null)
{
this.unit.removeBoxPointingToThis(this);
}
// Perform link
this.unit = unit;
// Add this to back pointers
if(this.unit != null)
{
this.unit.addBoxPointingToThis(this);
}
}
public Unit getUnit()
{
return unit;
}
public void toString(UnitPrinter up) {
up.startUnitBox(this);
up.unitRef(unit, isBranchTarget());
up.endUnitBox(this);
}
}