WALA/com.ibm.wala.core/src/com/ibm/wala/analysis/pointers/HeapGraph.java

/*******************************************************************************
 * Copyright (c) 2002 - 2006 IBM Corporation.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package com.ibm.wala.analysis.pointers;

import java.util.Collection;
import java.util.Iterator;
import java.util.Set;

import com.ibm.wala.ipa.callgraph.propagation.HeapModel;
import com.ibm.wala.ipa.callgraph.propagation.InstanceKey;
import com.ibm.wala.util.collections.Filter;
import com.ibm.wala.util.graph.NumberedGraph;
import com.ibm.wala.util.graph.impl.NumberedNodeIterator;
import com.ibm.wala.util.graph.traverse.DFS;
import com.ibm.wala.util.intset.IntSet;

/**
 * A Graph view of a pointer analysis solution.
 * 
 * Nodes in the Graph are PointerKeys and InstanceKeys.
 * 
 * There is an edge from a PointerKey P to an InstanceKey I iff the
 * PointerAnalysis indicates that P may point to I.
 * 
 * There is an edge from an InstanceKey I to a PointerKey P iff - P represents a
 * field of an object instance modelled by I, or - P represents the array
 * contents of array instance I.
 * 
 * @author sfink
 * 
 */
public abstract class HeapGraph implements NumberedGraph<Object> {

  private final HeapModel hm;

  protected HeapGraph(HeapModel hm) {
    this.hm = hm;
  }

  /*
   * @see com.ibm.wala.util.graph.NumberedNodeManager#iterateNodes(com.ibm.wala.util.intset.IntSet)
   */
  public Iterator<Object> iterateNodes(IntSet s) {
    return new NumberedNodeIterator<Object>(s, this);
  }

  public Collection<Object> getReachableInstances(Set<Object> roots) {
    Filter f = new Filter() {
      public boolean accepts(Object o) {
        return (o instanceof InstanceKey);
      }
    };
    return DFS.getReachableNodes(this, roots, f);
  }

  /*
   * @see com.ibm.wala.util.graph.Graph#removeNode(com.ibm.wala.util.graph.Node)
   */
  public void removeNodeAndEdges(Object N) {
    throw new UnsupportedOperationException();
  }

  /**
   * @return Returns the heap model used in this pointer analysis.
   */
  public HeapModel getHeapModel() {
    return hm;
  }

}