soot.AbstractUnit Maven / Gradle / Ivy
/* 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;
import soot.tagkit.*;
import soot.util.*;
import java.util.*;
/** Provides default implementations for the methods in Unit. */
public abstract class AbstractUnit extends AbstractHost implements Unit
{
/** Returns a deep clone of this object. */
public abstract Object clone();
/** Returns a list of Boxes containing Values used in this Unit.
* The list of boxes is dynamically updated as the structure changes.
* Note that they are returned in usual evaluation order.
* (this is important for aggregation)
*/
public List getUseBoxes()
{
return emptyList;
}
/** Returns a list of Boxes containing Values defined in this Unit.
* The list of boxes is dynamically updated as the structure changes.
*/
public List getDefBoxes()
{
return emptyList;
}
/** Returns a list of Boxes containing Units defined in this Unit; typically
* branch targets.
* The list of boxes is dynamically updated as the structure changes.
*/
public List getUnitBoxes()
{
return emptyList;
}
/** Canonical AbstractUnit.emptyList list. */
static final public List emptyList = Collections.EMPTY_LIST;
/** List of UnitBoxes pointing to this Unit. */
List boxesPointingToThis = null;
/** List of ValueBoxes contained in this Unit. */
List valueBoxes = null;
/** Returns a list of Boxes pointing to this Unit. */
public List getBoxesPointingToThis()
{
if( boxesPointingToThis == null ) return emptyList;
return Collections.unmodifiableList( boxesPointingToThis );
}
public void addBoxPointingToThis( UnitBox b ) {
if( boxesPointingToThis == null ) boxesPointingToThis = new ArrayList();
boxesPointingToThis.add( b );
}
public void removeBoxPointingToThis( UnitBox b ) {
if( boxesPointingToThis != null ) boxesPointingToThis.remove( b );
}
public void clearUnitBoxes() {
for( Iterator it = getUnitBoxes().iterator(); it.hasNext(); ) {
UnitBox ub = (UnitBox) it.next();
ub.setUnit(null);
}
}
/** Returns a list of ValueBoxes, either used or defined in this Unit. */
public List getUseAndDefBoxes()
{
List useBoxes = getUseBoxes();
List defBoxes = getDefBoxes();
if( useBoxes.isEmpty() ) {
if( defBoxes.isEmpty() ) {
return emptyList;
} else {
return Collections.unmodifiableList(defBoxes);
}
} else {
if( defBoxes.isEmpty() ) {
return Collections.unmodifiableList(useBoxes);
} else {
valueBoxes = new ArrayList();
valueBoxes.addAll(defBoxes);
valueBoxes.addAll(useBoxes);
valueBoxes = Collections.unmodifiableList(valueBoxes);
return valueBoxes;
}
}
}
/** Used to implement the Switchable construct. */
public void apply(Switch sw)
{
}
public void redirectJumpsToThisTo(Unit newLocation)
{
List boxesPointing = this.getBoxesPointingToThis();
Object[] boxes = boxesPointing.toArray();
// important to change this to an array to have a static copy
for (Object element : boxes) {
UnitBox box = (UnitBox) element;
if(box.getUnit() != this)
throw new RuntimeException("Something weird's happening");
if(box.isBranchTarget())
box.setUnit(newLocation);
}
}
}