2 files changed, 36 insertions, 21 deletions

diff --git a/include/clang/Analysis/PathSensitive/ExplodedGraph.h b/include/clang/Analysis/PathSensitive/ExplodedGraph.h
index 5420a6d87a..9c37039b7a 100644
--- a/include/clang/Analysis/PathSensitive/ExplodedGraph.h
+++ b/include/clang/Analysis/PathSensitive/ExplodedGraph.h
@@ -24,11 +24,11 @@
 
 namespace clang {
   
-class ReachabilityEngineImpl;
+class GREngineImpl;
   
 class ExplodedGraphImpl {
 protected:
-  friend class ReachabilityEngineImpl;
+  friend class GREngineImpl;
   
   // Type definitions.
   typedef llvm::DenseMap<ProgramEdge,void*>         EdgeNodeSetMap;  
@@ -59,9 +59,9 @@ protected:
 
   /// getNodeImpl - Retrieve the node associated with a (Location,State)
   ///  pair, where 'State' is represented as an opaque void*.  This method
-  ///  is intended to be used only by ReachabilityEngineImpl.
+  ///  is intended to be used only by GREngineImpl.
   virtual ExplodedNodeImpl* getNodeImpl(const ProgramEdge& L, void* State,
-                                       bool* IsNew) = 0;
+                                        bool* IsNew) = 0;
                                                             
   /// addRoot - Add an untyped node to the set of roots.
   ExplodedNodeImpl* addRoot(ExplodedNodeImpl* V) {
@@ -96,7 +96,7 @@ protected:
 protected:
   virtual ExplodedNodeImpl*
   getNodeImpl(const ProgramEdge& L, void* State, bool* IsNew) {
-    return getNode(L,ReachabilityTrait<StateTy>::toState(State),IsNew);
+    return getNode(L,GRTrait<StateTy>::toState(State),IsNew);
   }
     
 public:
@@ -131,15 +131,15 @@ public:
     void* InsertPos = 0;
     
     StateTy::Profile(profile, State);
-    NodeTy* V = VSet.FindNodeOrInsertPos(profile,InsertPos);
+    NodeTy* V = VSet.FindNodeOrInsertPos(profile, InsertPos);
 
     if (!V) {
       // Allocate a new node.
       V = (NodeTy*) Allocator.Allocate<NodeTy>();
-      new (V) NodeTy(NodeCounter++,L,State);
+      new (V) NodeTy(NodeCounter++, L, State);
       
       // Insert the node into the node set and return it.
-      VSet.InsertNode(V,InsertPos);
+      VSet.InsertNode(V, InsertPos);
       
       if (IsNew) *IsNew = true;
     }
diff --git a/include/clang/Analysis/PathSensitive/ExplodedNode.h b/include/clang/Analysis/PathSensitive/ExplodedNode.h
index c8828347ff..48ba0e29bb 100644
--- a/include/clang/Analysis/PathSensitive/ExplodedNode.h
+++ b/include/clang/Analysis/PathSensitive/ExplodedNode.h
@@ -24,16 +24,20 @@
 
 namespace clang {
   
-class ReachabilityEngineImpl;
+class GREngineImpl;
 
 class ExplodedNodeImpl : public llvm::FoldingSetNode {
 protected:
-  friend class ReachabilityEngineImpl;
+  friend class GREngineImpl;
   
   /// nodeID - A unique ID for the node.  This number indicates the
   ///  creation order of vertices, with lower numbers being created first.
   ///  The first created node has nodeID == 0.
-  const unsigned nodeID;
+  const unsigned nodeID:30;
+  
+  /// IsInfeasible - Indicates whether the node represents an infeasible
+  ///  program state.
+  unsigned IsInfeasible:1;
   
   /// Location - The program location (within a function body) associated
   ///  with this node.  The location is a 'ProgramEdge' in the CFG.
@@ -57,13 +61,16 @@ protected:
   /// Construct a ExplodedNodeImpl with the given node ID, program edge,
   ///  and state.
   explicit ExplodedNodeImpl(unsigned ID, const ProgramEdge& loc, void* state)
-    : nodeID(ID), Location(loc), State(state) {}
+    : nodeID(ID), IsInfeasible(0), Location(loc), State(state) {}
 
   /// addUntypedPredeccessor - Adds a predecessor to the current node, and 
   ///  in tandem add this node as a successor of the other node.  This
-  ///  "untyped" version is intended to be used only by ReachabilityEngineImpl;
+  ///  "untyped" version is intended to be used only by GREngineImpl;
   ///  normal clients should use 'addPredecessor' in ExplodedNode<>.
   void addUntypedPredecessor(ExplodedNodeImpl* V) {
+    assert (!V->isInfeasible() &&
+            "Cannot add successors to an infeasible node.");
+    
     Preds.push_back(V);
     V->Succs.push_back(V);
   }
@@ -72,18 +79,26 @@ public:
   /// getLocation - Returns the edge associated with the given node.
   const ProgramEdge& getLocation() const { return Location; }
   
-  /// getnodeID - Returns the unique ID of the node.  These IDs reflect
-  ///  the order in which vertices were generated by ReachabilityEngineImpl.
-  unsigned getnodeID() const { return nodeID; }
+  /// getNodeID - Returns the unique ID of the node.  These IDs reflect
+  ///  the order in which vertices were generated by GREngineImpl.
+  unsigned getNodeID() const { return nodeID; }
+  
+  /// isInfeasible - Returns true if the node represents an infeasible
+  ///  program state.
+  bool isInfeasible() const { return IsInfeasible ? true : false; }
+  
+  /// markInfeasible - The node is marked as being an infeasible program
+  ///  state.
+  void markInfeasible() { Infeasible = 1; }
+  
 };
 
   
 template <typename StateTy>
-struct ReachabilityTrait {
+struct GRTrait {
   static inline void* toPtr(StateTy S) {
     return reinterpret_cast<void*>(S);
-  }
-  
+  }  
   static inline StateTy toState(void* P) {
     return reinterpret_cast<StateTy>(P);
   }
@@ -96,11 +111,11 @@ public:
   /// Construct a ExplodedNodeImpl with the given node ID, program edge,
   ///  and state.
   explicit ExplodedNode(unsigned ID, const ProgramEdge& loc, StateTy state)
-  : ExplodedNodeImpl(ID,loc,ReachabilityTrait<StateTy>::toPtr(state)) {}
+  : ExplodedNodeImpl(ID,loc,GRTrait<StateTy>::toPtr(state)) {}
   
   /// getState - Returns the state associated with the node.  
   inline StateTy getState() const {
-    return ReachabilityTrait<StateTy>::toState(State);
+    return GRTrait<StateTy>::toState(State);
   }
   
   // Profiling (for FoldingSet).