X-Git-Url: http://plrg.eecs.uci.edu/git/?p=IRC.git;a=blobdiff_plain;f=Robust%2Fsrc%2FAnalysis%2FSSJava%2FFlowGraph.java;h=2ab6dad9ce625cac5d96cda64b5d4f1f989c8b6a;hp=a2d1791bb8a698609a668910a803c9a742774a76;hb=9dfdca00acf795117136425841493a1b0f036f10;hpb=5b4d50ee3ad588d3c4a1406c26c1e602d04e5581

diff --git a/Robust/src/Analysis/SSJava/FlowGraph.java b/Robust/src/Analysis/SSJava/FlowGraph.java
index a2d1791b..2ab6dad9 100644
--- a/Robust/src/Analysis/SSJava/FlowGraph.java
+++ b/Robust/src/Analysis/SSJava/FlowGraph.java
@@ -19,74 +19,157 @@ public class FlowGraph {
 
   MethodDescriptor md;
 
-  Set<FlowNode> nodeSet;
   Set<FlowNode> returnNodeSet;
   FlowNode thisVarNode;
 
+  Map<FlowNode, Set<FlowEdge>> mapFlowNodeToInEdgeSet;
+  Map<FlowNode, Set<FlowEdge>> mapFlowNodeToOutEdgeSet;
+
   Map<NTuple<Location>, FlowNode> mapLocTupleToFlowNode;
   Map<FlowNode, NTuple<Location>> mapFlowNodeToLocTuple;
 
   // maps the composite representation of field/var descriptors to infer nodes
   Map<NTuple<Descriptor>, FlowNode> mapDescTupleToInferNode;
 
-  // maps an infer node to the set of neighbors which is pointed by the node
-  Map<NTuple<Descriptor>, Set<FlowNode>> mapNodeToNeighborSet;
-
   // maps a paramter descriptor to its index
   Map<Descriptor, Integer> mapParamDescToIdx;
+
+  // DS for the lattice generation
+  Map<Integer, FlowNode> mapIdxToFlowNode;
+
+  public static int interseed = 0;
+
   boolean debug = true;
 
   public FlowGraph(MethodDescriptor md, Map<Descriptor, Integer> mapParamDescToIdx) {
     this.md = md;
     this.mapFlowNodeToLocTuple = new HashMap<FlowNode, NTuple<Location>>();
     this.mapLocTupleToFlowNode = new HashMap<NTuple<Location>, FlowNode>();
-    this.nodeSet = new HashSet<FlowNode>();
     this.mapDescTupleToInferNode = new HashMap<NTuple<Descriptor>, FlowNode>();
-    this.mapNodeToNeighborSet = new HashMap<NTuple<Descriptor>, Set<FlowNode>>();
     this.mapParamDescToIdx = new HashMap<Descriptor, Integer>();
     this.mapParamDescToIdx.putAll(mapParamDescToIdx);
     this.returnNodeSet = new HashSet<FlowNode>();
+    this.mapIdxToFlowNode = new HashMap<Integer, FlowNode>();
+    this.mapFlowNodeToOutEdgeSet = new HashMap<FlowNode, Set<FlowEdge>>();
+    this.mapFlowNodeToInEdgeSet = new HashMap<FlowNode, Set<FlowEdge>>();
 
     if (!md.isStatic()) {
       // create a node for 'this' varialbe
-      NTuple<Descriptor> thisDescTuple = new NTuple<Descriptor>();
-      thisDescTuple.add(md.getThis());
-      FlowNode thisNode = new FlowNode(thisDescTuple, true);
+      // NTuple<Descriptor> thisDescTuple = new NTuple<Descriptor>();
+      // thisDescTuple.add(md.getThis());
+
       NTuple<Descriptor> thisVarTuple = new NTuple<Descriptor>();
       thisVarTuple.add(md.getThis());
-      createNewFlowNode(thisVarTuple);
+      FlowNode thisNode = createNewFlowNode(thisVarTuple);
+      thisNode.setSkeleton(true);
       thisVarNode = thisNode;
     }
 
+    setupMapIdxToDesc();
+
   }
 
-  public Set<FlowNode> getNodeSet() {
-    return nodeSet;
+  public Map<NTuple<Descriptor>, FlowNode> getMapDescTupleToInferNode() {
+    return mapDescTupleToInferNode;
   }
 
-  public MethodDescriptor getMethodDescriptor() {
-    return md;
+  public void setMapDescTupleToInferNode(Map<NTuple<Descriptor>, FlowNode> in) {
+    this.mapDescTupleToInferNode.putAll(in);
   }
 
-  public Set<FlowNode> getParameterNodeSet() {
-    Set<FlowNode> paramNodeSet = new HashSet<FlowNode>();
+  public Map<NTuple<Location>, FlowNode> getMapLocTupleToFlowNode() {
+    return mapLocTupleToFlowNode;
+  }
+
+  public void setMapLocTupleToFlowNode(Map<NTuple<Location>, FlowNode> in) {
+    this.mapLocTupleToFlowNode.putAll(in);
+  }
+
+  public void setReturnNodeSet(Set<FlowNode> in) {
+    this.returnNodeSet.addAll(in);
+  }
+
+  public void setThisVarNode(FlowNode thisVarNode) {
+    this.thisVarNode = thisVarNode;
+  }
+
+  public Map<Descriptor, Integer> getMapParamDescToIdx() {
+    return mapParamDescToIdx;
+  }
+
+  public FlowNode createIntermediateNode() {
+    NTuple<Descriptor> tuple = new NTuple<Descriptor>();
+    Descriptor interDesc = new InterDescriptor(LocationInference.INTERLOC + interseed);
+    tuple.add(interDesc);
+    interseed++;
+
+    FlowNode newNode = new FlowNode(tuple);
+    newNode.setIntermediate(true);
+
+    mapDescTupleToInferNode.put(tuple, newNode);
+    // nodeSet.add(newNode);
+
+     System.out.println("create new intermediate node= " + newNode);
+
+    return newNode;
+  }
+
+  private void setupMapIdxToDesc() {
+
+    Set<Descriptor> descSet = mapParamDescToIdx.keySet();
+    for (Iterator iterator = descSet.iterator(); iterator.hasNext();) {
+      Descriptor paramDesc = (Descriptor) iterator.next();
+      int idx = mapParamDescToIdx.get(paramDesc);
+      NTuple<Descriptor> descTuple = new NTuple<Descriptor>();
+      descTuple.add(paramDesc);
+      FlowNode paramNode = getFlowNode(descTuple);
+      mapIdxToFlowNode.put(idx, paramNode);
+      paramNode.setSkeleton(true);
+    }
+
+  }
+
+  public int getNumParameters() {
+    return mapIdxToFlowNode.keySet().size();
+  }
+
+  public FlowNode getParamFlowNode(int idx) {
+    return mapIdxToFlowNode.get(idx);
+  }
+
+  public Set<FlowEdge> getEdgeSet() {
+    Set<FlowEdge> edgeSet = new HashSet<FlowEdge>();
+
+    Set<FlowNode> nodeSet = getNodeSet();
     for (Iterator iterator = nodeSet.iterator(); iterator.hasNext();) {
-      FlowNode fn = (FlowNode) iterator.next();
-      if (fn.isParameter()) {
-        paramNodeSet.add(fn);
-      }
+      FlowNode flowNode = (FlowNode) iterator.next();
+      edgeSet.addAll(getOutEdgeSet(flowNode));
     }
-    return paramNodeSet;
+
+    return edgeSet;
   }
 
-  public void addNeighbor(FlowNode node, FlowNode neighbor) {
-    Set<FlowNode> set = mapNodeToNeighborSet.get(node);
-    if (set == null) {
-      set = new HashSet<FlowNode>();
+  public Set<FlowNode> getNodeSet() {
+    Set<FlowNode> set = new HashSet<FlowNode>();
+    set.addAll(mapDescTupleToInferNode.values());
+    return set;
+  }
+
+  public MethodDescriptor getMethodDescriptor() {
+    return md;
+  }
+
+  public boolean isParamDesc(Descriptor desc) {
+
+    if (mapParamDescToIdx.containsKey(desc)) {
+      int idx = mapParamDescToIdx.get(desc);
+      if (!md.isStatic() && idx == 0) {
+        return false;
+      }
+      return true;
     }
-    set.add(neighbor);
 
-    System.out.println("add a new neighbor " + neighbor + " to " + node);
+    return false;
   }
 
   public boolean hasEdge(NTuple<Descriptor> fromDescTuple, NTuple<Descriptor> toDescTuple) {
@@ -94,7 +177,7 @@ public class FlowGraph {
     FlowNode fromNode = mapDescTupleToInferNode.get(fromDescTuple);
     FlowNode toNode = mapDescTupleToInferNode.get(toDescTuple);
 
-    Set<FlowEdge> fromNodeOutEdgeSet = fromNode.getOutEdgeSet();
+    Set<FlowEdge> fromNodeOutEdgeSet = getOutEdgeSet(fromNode);
     for (Iterator iterator = fromNodeOutEdgeSet.iterator(); iterator.hasNext();) {
       FlowEdge flowEdge = (FlowEdge) iterator.next();
       if (flowEdge.getDst().equals(toNode)) {
@@ -109,28 +192,80 @@ public class FlowGraph {
     return false;
   }
 
+  public Set<FlowEdge> getOutEdgeSetStartingFrom(FlowNode startNode) {
+
+    Descriptor prefixDesc = startNode.getCurrentDescTuple().get(0);
+
+    // returns the set of edges that share the same prefix of startNode
+    Set<FlowEdge> edgeSet = new HashSet<FlowEdge>();
+
+    for (Iterator<Set<FlowEdge>> iter = mapFlowNodeToOutEdgeSet.values().iterator(); iter.hasNext();) {
+      Set<FlowEdge> nodeEdgeSet = iter.next();
+      for (Iterator<FlowEdge> iter2 = nodeEdgeSet.iterator(); iter2.hasNext();) {
+        FlowEdge edge = iter2.next();
+        if (edge.getInitTuple().get(0).equals(prefixDesc)) {
+          edgeSet.add(edge);
+        }
+      }
+    }
+
+    return edgeSet;
+  }
+
+  public Set<FlowEdge> getOutEdgeSet(FlowNode node) {
+    if (!mapFlowNodeToOutEdgeSet.containsKey(node)) {
+      mapFlowNodeToOutEdgeSet.put(node, new HashSet<FlowEdge>());
+    }
+    return mapFlowNodeToOutEdgeSet.get(node);
+  }
+
+  public Set<FlowEdge> getInEdgeSet(FlowNode node) {
+    if (!mapFlowNodeToInEdgeSet.containsKey(node)) {
+      mapFlowNodeToInEdgeSet.put(node, new HashSet<FlowEdge>());
+    }
+    return mapFlowNodeToInEdgeSet.get(node);
+  }
+
   public void addValueFlowEdge(NTuple<Descriptor> fromDescTuple, NTuple<Descriptor> toDescTuple) {
 
-    FlowNode fromNode = mapDescTupleToInferNode.get(fromDescTuple);
-    FlowNode toNode = mapDescTupleToInferNode.get(toDescTuple);
+    FlowNode fromNode = getFlowNode(fromDescTuple);
+    FlowNode toNode = getFlowNode(toDescTuple);
+
+    if (toNode.getDescTuple().get(0).equals(LocationInference.LITERALDESC)) {
+      return;
+    }
 
     System.out.println("create an edge from " + fromNode + " to " + toNode);
 
     int fromTupleSize = fromDescTuple.size();
-    NTuple<Descriptor> curTuple = new NTuple<Descriptor>();
+    NTuple<Descriptor> curFromTuple = new NTuple<Descriptor>();
     for (int i = 0; i < fromTupleSize; i++) {
       Descriptor desc = fromDescTuple.get(i);
-      curTuple.add(desc);
-      addFlowEdge(getFlowNode(curTuple), toNode, fromDescTuple, toDescTuple);
+      curFromTuple.add(desc);
+      int toTupleSize = toDescTuple.size();
+      NTuple<Descriptor> curToTuple = new NTuple<Descriptor>();
+      for (int k = 0; k < toTupleSize; k++) {
+        Descriptor toDesc = toDescTuple.get(k);
+        curToTuple.add(toDesc);
+        addFlowEdge(getFlowNode(curFromTuple), getFlowNode(curToTuple), fromDescTuple, toDescTuple);
+      }
     }
 
-    int toTupleSize = toDescTuple.size();
-    curTuple = new NTuple<Descriptor>();
-    for (int i = 0; i < toTupleSize; i++) {
-      Descriptor desc = toDescTuple.get(i);
-      curTuple.add(desc);
-      addFlowEdge(fromNode, getFlowNode(curTuple), fromDescTuple, toDescTuple);
-    }
+    // int fromTupleSize = fromDescTuple.size();
+    // NTuple<Descriptor> curTuple = new NTuple<Descriptor>();
+    // for (int i = 0; i < fromTupleSize; i++) {
+    // Descriptor desc = fromDescTuple.get(i);
+    // curTuple.add(desc);
+    // addFlowEdge(getFlowNode(curTuple), toNode, fromDescTuple, toDescTuple);
+    // }
+    //
+    // int toTupleSize = toDescTuple.size();
+    // curTuple = new NTuple<Descriptor>();
+    // for (int i = 0; i < toTupleSize; i++) {
+    // Descriptor desc = toDescTuple.get(i);
+    // curTuple.add(desc);
+    // addFlowEdge(fromNode, getFlowNode(curTuple), fromDescTuple, toDescTuple);
+    // }
 
   }
 
@@ -138,19 +273,33 @@ public class FlowGraph {
       NTuple<Descriptor> endTuple) {
 
     FlowEdge edge = new FlowEdge(fromNode, toNode, initTuple, endTuple);
-    fromNode.addOutEdge(edge);
+    addOutEdge(fromNode, edge);
+    addInEdge(toNode, edge);
+
+    // System.out.println("add a new edge=" + edge);
+  }
+
+  private void addInEdge(FlowNode toNode, FlowEdge edge) {
+    getInEdgeSet(toNode).add(edge);
+  }
 
-    System.out.println("add a new edge=" + edge);
+  private void addOutEdge(FlowNode fromNode, FlowEdge edge) {
+    if (!mapFlowNodeToOutEdgeSet.containsKey(fromNode)) {
+      mapFlowNodeToOutEdgeSet.put(fromNode, new HashSet<FlowEdge>());
+    }
+    mapFlowNodeToOutEdgeSet.get(fromNode).add(edge);
+  }
 
+  public boolean contains(NTuple<Descriptor> descTuple) {
+    return mapDescTupleToInferNode.containsKey(descTuple);
   }
 
   public FlowNode getFlowNode(NTuple<Descriptor> descTuple) {
-    if (mapDescTupleToInferNode.containsKey(descTuple)) {
-      return mapDescTupleToInferNode.get(descTuple);
-    } else {
+    if (!mapDescTupleToInferNode.containsKey(descTuple)) {
       FlowNode node = createNewFlowNode(descTuple);
-      return node;
+      mapDescTupleToInferNode.put(descTuple, node);
     }
+    return mapDescTupleToInferNode.get(descTuple);
   }
 
   public FlowNode getThisVarNode() {
@@ -160,10 +309,9 @@ public class FlowGraph {
   public FlowNode createNewFlowNode(NTuple<Descriptor> tuple) {
 
     if (!mapDescTupleToInferNode.containsKey(tuple)) {
-
-      FlowNode node = new FlowNode(tuple, isParamter(tuple));
+      FlowNode node = new FlowNode(tuple);
       mapDescTupleToInferNode.put(tuple, node);
-      nodeSet.add(node);
+      // nodeSet.add(node);
 
       mapLocTupleToFlowNode.put(getLocationTuple(node), node);
 
@@ -172,7 +320,7 @@ public class FlowGraph {
         getFlowNode(baseTuple).addFieldNode(node);
       }
 
-      System.out.println("Creating new node=" + node);
+      // System.out.println("Creating new node=" + node);
       return node;
     } else {
       return mapDescTupleToInferNode.get(tuple);
@@ -180,15 +328,13 @@ public class FlowGraph {
 
   }
 
-  public void setReturnFlowNode(NTuple<Descriptor> tuple) {
+  public void addReturnFlowNode(NTuple<Descriptor> tuple) {
 
     if (!mapDescTupleToInferNode.containsKey(tuple)) {
       createNewFlowNode(tuple);
     }
 
     FlowNode node = mapDescTupleToInferNode.get(tuple);
-    node.setReturn(true);
-
     returnNodeSet.add(node);
   }
 
@@ -196,32 +342,102 @@ public class FlowGraph {
     return returnNodeSet;
   }
 
-  public Set<FlowNode> getReachableFlowNodeSet(FlowNode fn) {
+  public Set<FlowNode> getLocalReachFlowNodeSetFrom(FlowNode fn) {
     Set<FlowNode> set = new HashSet<FlowNode>();
-    getReachableFlowNodeSet(fn, set);
+    recurLocalReachFlowNodeSet(fn, set);
     return set;
   }
 
-  private void getReachableFlowNodeSet(FlowNode fn, Set<FlowNode> visited) {
+  private void recurLocalReachFlowNodeSet(FlowNode fn, Set<FlowNode> visited) {
 
-    for (Iterator iterator = fn.getOutEdgeSet().iterator(); iterator.hasNext();) {
+    Set<FlowEdge> outEdgeSet = getOutEdgeSet(fn);
+    for (Iterator iterator = outEdgeSet.iterator(); iterator.hasNext();) {
       FlowEdge edge = (FlowEdge) iterator.next();
+      FlowNode dstNode = edge.getDst();
 
-      if (fn.equals(getFlowNode(edge.getInitTuple()))) {
+      if (!visited.contains(dstNode)) {
+        visited.add(dstNode);
+        recurLocalReachFlowNodeSet(dstNode, visited);
+      }
+    }
 
-        FlowNode dstNode = getFlowNode(edge.getEndTuple());
+  }
+
+  private void getReachFlowNodeSetFrom(FlowNode fn, Set<FlowNode> visited) {
 
+    Set<FlowEdge> outEdgeSet = getOutEdgeSet(fn);
+    for (Iterator iterator = outEdgeSet.iterator(); iterator.hasNext();) {
+      FlowEdge edge = (FlowEdge) iterator.next();
+
+      if (fn.equals(getFlowNode(edge.getInitTuple()))) {
+        FlowNode dstNode = getFlowNode(edge.getEndTuple());
         if (!visited.contains(dstNode)) {
           visited.add(dstNode);
-          getReachableFlowNodeSet(dstNode, visited);
+          getReachFlowNodeSetFrom(dstNode, visited);
         }
       }
     }
 
   }
 
+  public Set<FlowNode> getReachFlowNodeSetFrom(FlowNode fn) {
+    Set<FlowNode> set = new HashSet<FlowNode>();
+    getReachFlowNodeSetFrom(fn, set);
+    return set;
+  }
+
+  public Set<FlowNode> getReachableSetFrom(NTuple<Descriptor> prefix) {
+    Set<FlowNode> reachableSet = new HashSet<FlowNode>();
+
+    Set<FlowNode> nodeSet = getNodeSet();
+    for (Iterator iterator = nodeSet.iterator(); iterator.hasNext();) {
+      FlowNode flowNode = (FlowNode) iterator.next();
+      if (flowNode.getCurrentDescTuple().startsWith(prefix)) {
+        recurReachableSetFrom(flowNode, reachableSet);
+      }
+    }
+
+    return reachableSet;
+  }
+
+  // private void getReachFlowNodeSetFrom(FlowNode fn, Set<FlowNode> visited) {
+  //
+  // for (Iterator iterator = fn.getOutEdgeSet().iterator();
+  // iterator.hasNext();) {
+  // FlowEdge edge = (FlowEdge) iterator.next();
+  //
+  // if (fn.equals(getFlowNode(edge.getInitTuple()))) {
+  //
+  // FlowNode dstNode = getFlowNode(edge.getEndTuple());
+  //
+  // if (!visited.contains(dstNode)) {
+  // visited.add(dstNode);
+  // getReachFlowNodeSetFrom(dstNode, visited);
+  // }
+  // }
+  // }
+  //
+  // }
+
+  private void recurReachableSetFrom(FlowNode curNode, Set<FlowNode> reachableSet) {
+
+    Set<FlowEdge> edgeSet = getOutEdgeSet(curNode);
+    for (Iterator iterator = edgeSet.iterator(); iterator.hasNext();) {
+      FlowEdge edge = (FlowEdge) iterator.next();
+      FlowNode dstNode = getFlowNode(edge.getEndTuple());
+      if (!reachableSet.contains(dstNode)) {
+        reachableSet.add(dstNode);
+        recurReachableSetFrom(dstNode, reachableSet);
+      }
+    }
+
+  }
+
   public Set<NTuple<Location>> getReachableFlowTupleSet(Set<NTuple<Location>> visited, FlowNode fn) {
-    for (Iterator iterator = fn.getOutEdgeSet().iterator(); iterator.hasNext();) {
+
+    Set<FlowEdge> outEdgeSet = getOutEdgeSet(fn);
+
+    for (Iterator iterator = outEdgeSet.iterator(); iterator.hasNext();) {
       FlowEdge edge = (FlowEdge) iterator.next();
 
       if (fn.getDescTuple().equals(edge.getInitTuple())) {
@@ -238,6 +454,10 @@ public class FlowGraph {
     return visited;
   }
 
+  public NTuple<Location> getLocationTuple(NTuple<Descriptor> descTuple) {
+    return getLocationTuple(getFlowNode(descTuple));
+  }
+
   public NTuple<Location> getLocationTuple(FlowNode fn) {
 
     if (!mapFlowNodeToLocTuple.containsKey(fn)) {
@@ -245,20 +465,52 @@ public class FlowGraph {
       NTuple<Location> locTuple = new NTuple<Location>();
       ClassDescriptor cd = null;
 
-      for (int i = 0; i < descTuple.size(); i++) {
-        Descriptor curDesc = descTuple.get(i);
-        Location loc;
-        if (i == 0) {
-          loc = new Location(md, curDesc.getSymbol());
-          loc.setLocDescriptor(md);
-          cd = ((VarDescriptor) curDesc).getType().getClassDesc();
-        } else {
-          loc = new Location(cd, curDesc.getSymbol());
-          loc.setLocDescriptor(curDesc);
-          cd = ((FieldDescriptor) curDesc).getType().getClassDesc();
+      Descriptor localDesc = fn.getDescTuple().get(0);
+
+      if (fn.isIntermediate()) {
+        Location interLoc = new Location(md, localDesc.getSymbol());
+        interLoc.setLocDescriptor(localDesc);
+        locTuple.add(interLoc);
+      } else if (localDesc.getSymbol().equals(SSJavaAnalysis.TOP)) {
+        Location topLoc = new Location(md, Location.TOP);
+        topLoc.setLocDescriptor(LocationInference.TOPDESC);
+        locTuple.add(topLoc);
+      } else if (localDesc.getSymbol().equals(LocationInference.GLOBALLOC)) {
+        Location globalLoc = new Location(md, LocationInference.GLOBALLOC);
+        globalLoc.setLocDescriptor(LocationInference.GLOBALDESC);
+        locTuple.add(globalLoc);
+      } else {
+        // normal case
+        for (int i = 0; i < descTuple.size(); i++) {
+          Descriptor curDesc = descTuple.get(i);
+          Location loc;
+          if (i == 0) {
+            loc = new Location(md, curDesc.getSymbol());
+            loc.setLocDescriptor(curDesc);
+            if (curDesc instanceof VarDescriptor) {
+              cd = ((VarDescriptor) curDesc).getType().getClassDesc();
+            } else {
+              // otherwise it should be the last element
+              cd = null;
+            }
+          } else {
+            loc = new Location(cd, curDesc.getSymbol());
+            loc.setLocDescriptor(curDesc);
+
+            if (curDesc instanceof FieldDescriptor) {
+              cd = ((FieldDescriptor) curDesc).getType().getClassDesc();
+            } else if (curDesc instanceof LocationDescriptor) {
+              cd = ((LocationDescriptor) curDesc).getEnclosingClassDesc();
+            } else {
+              // otherwise it should be the last element of the tuple
+              cd = null;
+            }
+
+          }
+          locTuple.add(loc);
         }
-        locTuple.add(loc);
       }
+
       mapFlowNodeToLocTuple.put(fn, locTuple);
     }
     return mapFlowNodeToLocTuple.get(fn);
@@ -272,9 +524,9 @@ public class FlowGraph {
 
   public void getIncomingFlowNodeSet(FlowNode node, Set<FlowNode> visited) {
 
-    for (Iterator iterator = nodeSet.iterator(); iterator.hasNext();) {
+    for (Iterator iterator = getNodeSet().iterator(); iterator.hasNext();) {
       FlowNode curNode = (FlowNode) iterator.next();
-      Set<FlowEdge> edgeSet = curNode.getOutEdgeSet();
+      Set<FlowEdge> edgeSet = getOutEdgeSet(curNode);
 
       for (Iterator iterator2 = edgeSet.iterator(); iterator2.hasNext();) {
         FlowEdge flowEdge = (FlowEdge) iterator2.next();
@@ -300,9 +552,10 @@ public class FlowGraph {
 
     ClassDescriptor cd = null;
 
-    for (Iterator iterator = nodeSet.iterator(); iterator.hasNext();) {
+    for (Iterator iterator = getNodeSet().iterator(); iterator.hasNext();) {
       FlowNode node = (FlowNode) iterator.next();
-      Set<FlowEdge> edgeSet = node.getOutEdgeSet();
+
+      Set<FlowEdge> edgeSet = getOutEdgeSet(node);
       for (Iterator iterator2 = edgeSet.iterator(); iterator2.hasNext();) {
         FlowEdge flowEdge = (FlowEdge) iterator2.next();
         if (dstTuple.equals(flowEdge.getEndTuple())) {
@@ -327,21 +580,98 @@ public class FlowGraph {
     return set;
   }
 
-  public boolean isParamter(NTuple<Descriptor> tuple) {
+  public boolean isParameter(NTuple<Descriptor> tuple) {
     // return true if a descriptor tuple is started with a parameter descriptor
     Descriptor firstIdxDesc = tuple.get(0);
     return mapParamDescToIdx.containsKey(firstIdxDesc);
   }
 
   public int getParamIdx(NTuple<Descriptor> tuple) {
-    Descriptor firstDesc = tuple.get(0);
-    return mapParamDescToIdx.get(firstDesc).intValue();
+    Descriptor firstIdxDesc = tuple.get(0);
+    return mapParamDescToIdx.get(firstIdxDesc);
+  }
+
+  public FlowGraph clone() {
+    FlowGraph clone = new FlowGraph(md, mapParamDescToIdx);
+
+    // clone.setNodeSet(getNodeSet());
+    clone.setMapLocTupleToFlowNode(getMapLocTupleToFlowNode());
+    clone.setMapFlowNodeToLocTuple(getMapFlowNodeToLocTuple());
+    clone.setMapDescTupleToInferNode(getMapDescTupleToInferNode());
+
+    clone.setMapFlowNodeToOutEdgeSet(getMapFlowNodeToOutEdgeSet());
+    clone.setReturnNodeSet(getReturnNodeSet());
+    clone.setThisVarNode(getThisVarNode());
+
+    return clone;
+  }
+
+  public Map<FlowNode, NTuple<Location>> getMapFlowNodeToLocTuple() {
+    return mapFlowNodeToLocTuple;
+  }
+
+  public void setMapFlowNodeToLocTuple(Map<FlowNode, NTuple<Location>> in) {
+    this.mapFlowNodeToLocTuple.putAll(in);
+  }
+
+  public Map<FlowNode, Set<FlowEdge>> getMapFlowNodeToOutEdgeSet() {
+    return mapFlowNodeToOutEdgeSet;
+  }
+
+  public Set<FlowNode> getIncomingNodeSetByPrefix(Descriptor prefix) {
+
+    Set<FlowNode> incomingNodeSet = new HashSet<FlowNode>();
+
+    for (Iterator iterator = getNodeSet().iterator(); iterator.hasNext();) {
+      FlowNode curNode = (FlowNode) iterator.next();
+      Set<FlowEdge> outEdgeSet = getOutEdgeSet(curNode);
+
+      for (Iterator iterator2 = outEdgeSet.iterator(); iterator2.hasNext();) {
+        FlowEdge outEdge = (FlowEdge) iterator2.next();
+
+        if (outEdge.getEndTuple().startsWith(prefix)) {
+          incomingNodeSet.add(curNode);
+          recurIncomingNodeSetByPrefix(prefix, curNode, incomingNodeSet);
+
+        }
+
+      }
+    }
+
+    return incomingNodeSet;
+
+  }
+
+  private void recurIncomingNodeSetByPrefix(Descriptor prefix, FlowNode node, Set<FlowNode> visited) {
+
+    Set<FlowEdge> inEdgeSet = getInEdgeSet(node);
+
+    for (Iterator iterator = inEdgeSet.iterator(); iterator.hasNext();) {
+      FlowEdge inEdge = (FlowEdge) iterator.next();
+
+      FlowNode inNode = getFlowNode(inEdge.getInitTuple());
+      if (!inEdge.getInitTuple().startsWith(prefix) && !visited.contains(inNode)) {
+        visited.add(inNode);
+        recurIncomingNodeSetByPrefix(prefix, inNode, visited);
+      }
+    }
+
+  }
+
+  public void setMapFlowNodeToOutEdgeSet(Map<FlowNode, Set<FlowEdge>> inMap) {
+    Set<FlowNode> keySet = inMap.keySet();
+    for (Iterator iterator = keySet.iterator(); iterator.hasNext();) {
+      FlowNode key = (FlowNode) iterator.next();
+      Set<FlowEdge> newEdgeSet = new HashSet<FlowEdge>();
+      newEdgeSet.addAll(inMap.get(key));
+      mapFlowNodeToOutEdgeSet.put(key, newEdgeSet);
+    }
   }
 
   private void drawEdges(FlowNode node, BufferedWriter bw, Set<FlowNode> addedNodeSet,
       Set<FlowEdge> addedEdgeSet) throws IOException {
 
-    Set<FlowEdge> edgeSet = node.getOutEdgeSet();
+    Set<FlowEdge> edgeSet = getOutEdgeSet(node);
 
     for (Iterator<FlowEdge> iterator = edgeSet.iterator(); iterator.hasNext();) {
       FlowEdge flowEdge = iterator.next();
@@ -378,8 +708,12 @@ public class FlowGraph {
   }
 
   public void writeGraph() throws java.io.IOException {
+    writeGraph("");
+  }
 
-    String graphName = "flowgraph_" + md.toString();
+  public void writeGraph(String suffix) throws java.io.IOException {
+
+    String graphName = "flowgraph_" + md.toString() + suffix;
     graphName = graphName.replaceAll("[\\W]", "");
 
     BufferedWriter bw = new BufferedWriter(new FileWriter(graphName + ".dot"));
@@ -388,7 +722,8 @@ public class FlowGraph {
 
     // then visit every flow node
 
-    Iterator<FlowNode> iter = nodeSet.iterator();
+    // Iterator<FlowNode> iter = nodeSet.iterator();
+    Iterator<FlowNode> iter = getNodeSet().iterator();
 
     Set<FlowEdge> addedEdgeSet = new HashSet<FlowEdge>();
     Set<FlowNode> addedNodeSet = new HashSet<FlowNode>();
@@ -412,7 +747,7 @@ public class FlowGraph {
   }
 
   public boolean constainsNode(FlowNode node) {
-    return nodeSet.contains(node);
+    return getNodeSet().contains(node);
   }
 
   private void drawSubgraph(FlowNode node, BufferedWriter bw, Set<FlowEdge> addedSet)
@@ -444,4 +779,5 @@ public class FlowGraph {
 
     bw.write("}\n");
   }
+
 }
\ No newline at end of file