Check in LLVM r95781.
diff --git a/lib/Checker/RegionStore.cpp b/lib/Checker/RegionStore.cpp
new file mode 100644
index 0000000..d97fdbb
--- /dev/null
+++ b/lib/Checker/RegionStore.cpp
@@ -0,0 +1,1877 @@
+//== RegionStore.cpp - Field-sensitive store model --------------*- C++ -*--==//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines a basic region store model. In this model, we do have field
+// sensitivity. But we assume nothing about the heap shape. So recursive data
+// structures are largely ignored. Basically we do 1-limiting analysis.
+// Parameter pointers are assumed with no aliasing. Pointee objects of
+// parameters are created lazily.
+//
+//===----------------------------------------------------------------------===//
+#include "clang/Checker/PathSensitive/MemRegion.h"
+#include "clang/Analysis/AnalysisContext.h"
+#include "clang/Checker/PathSensitive/GRState.h"
+#include "clang/Checker/PathSensitive/GRStateTrait.h"
+#include "clang/Analysis/Analyses/LiveVariables.h"
+#include "clang/Analysis/Support/Optional.h"
+#include "clang/Basic/TargetInfo.h"
+#include "clang/AST/CharUnits.h"
+
+#include "llvm/ADT/ImmutableMap.h"
+#include "llvm/ADT/ImmutableList.h"
+#include "llvm/Support/raw_ostream.h"
+
+using namespace clang;
+
+#define USE_EXPLICIT_COMPOUND 0
+
+//===----------------------------------------------------------------------===//
+// Representation of binding keys.
+//===----------------------------------------------------------------------===//
+
+namespace {
+class BindingKey {
+public:
+  enum Kind { Direct = 0x0, Default = 0x1 };
+private:
+  llvm ::PointerIntPair<const MemRegion*, 1> P;
+  uint64_t Offset;  
+  
+  explicit BindingKey(const MemRegion *r, uint64_t offset, Kind k)
+    : P(r, (unsigned) k), Offset(offset) { assert(r); }
+public:
+  
+  bool isDefault() const { return P.getInt() == Default; }
+  bool isDirect() const { return P.getInt() == Direct; }
+  
+  const MemRegion *getRegion() const { return P.getPointer(); }
+  uint64_t getOffset() const { return Offset; }
+  
+  void Profile(llvm::FoldingSetNodeID& ID) const {
+    ID.AddPointer(P.getOpaqueValue());
+    ID.AddInteger(Offset);
+  }
+  
+  static BindingKey Make(const MemRegion *R, Kind k);
+  
+  bool operator<(const BindingKey &X) const {
+    if (P.getOpaqueValue() < X.P.getOpaqueValue())
+      return true;
+    if (P.getOpaqueValue() > X.P.getOpaqueValue())
+      return false;
+    return Offset < X.Offset;
+  }
+  
+  bool operator==(const BindingKey &X) const {
+    return P.getOpaqueValue() == X.P.getOpaqueValue() &&
+           Offset == X.Offset;
+  }
+};    
+} // end anonymous namespace
+
+namespace llvm {
+  static inline 
+  llvm::raw_ostream& operator<<(llvm::raw_ostream& os, BindingKey K) {
+    os << '(' << K.getRegion() << ',' << K.getOffset()
+       << ',' << (K.isDirect() ? "direct" : "default")
+       << ')';
+    return os;
+  }
+} // end llvm namespace
+
+//===----------------------------------------------------------------------===//
+// Actual Store type.
+//===----------------------------------------------------------------------===//
+
+typedef llvm::ImmutableMap<BindingKey, SVal> RegionBindings;
+
+//===----------------------------------------------------------------------===//
+// Fine-grained control of RegionStoreManager.
+//===----------------------------------------------------------------------===//
+
+namespace {
+struct minimal_features_tag {};
+struct maximal_features_tag {};
+
+class RegionStoreFeatures {
+  bool SupportsFields;
+  bool SupportsRemaining;
+
+public:
+  RegionStoreFeatures(minimal_features_tag) :
+    SupportsFields(false), SupportsRemaining(false) {}
+
+  RegionStoreFeatures(maximal_features_tag) :
+    SupportsFields(true), SupportsRemaining(false) {}
+
+  void enableFields(bool t) { SupportsFields = t; }
+
+  bool supportsFields() const { return SupportsFields; }
+  bool supportsRemaining() const { return SupportsRemaining; }
+};
+}
+
+//===----------------------------------------------------------------------===//
+// Region "Extents"
+//===----------------------------------------------------------------------===//
+//
+//  MemRegions represent chunks of memory with a size (their "extent").  This
+//  GDM entry tracks the extents for regions.  Extents are in bytes.
+//
+namespace { class RegionExtents {}; }
+static int RegionExtentsIndex = 0;
+namespace clang {
+  template<> struct GRStateTrait<RegionExtents>
+    : public GRStatePartialTrait<llvm::ImmutableMap<const MemRegion*, SVal> > {
+    static void* GDMIndex() { return &RegionExtentsIndex; }
+  };
+}
+
+//===----------------------------------------------------------------------===//
+// Utility functions.
+//===----------------------------------------------------------------------===//
+
+static bool IsAnyPointerOrIntptr(QualType ty, ASTContext &Ctx) {
+  if (ty->isAnyPointerType())
+    return true;
+
+  return ty->isIntegerType() && ty->isScalarType() &&
+         Ctx.getTypeSize(ty) == Ctx.getTypeSize(Ctx.VoidPtrTy);
+}
+
+//===----------------------------------------------------------------------===//
+// Main RegionStore logic.
+//===----------------------------------------------------------------------===//
+
+namespace {
+
+class RegionStoreSubRegionMap : public SubRegionMap {
+public:
+  typedef llvm::ImmutableSet<const MemRegion*> Set;
+  typedef llvm::DenseMap<const MemRegion*, Set> Map;
+private:
+  Set::Factory F;
+  Map M;
+public:
+  bool add(const MemRegion* Parent, const MemRegion* SubRegion) {
+    Map::iterator I = M.find(Parent);
+
+    if (I == M.end()) {
+      M.insert(std::make_pair(Parent, F.Add(F.GetEmptySet(), SubRegion)));
+      return true;
+    }
+
+    I->second = F.Add(I->second, SubRegion);
+    return false;
+  }
+
+  void process(llvm::SmallVectorImpl<const SubRegion*> &WL, const SubRegion *R);
+
+  ~RegionStoreSubRegionMap() {}
+  
+  const Set *getSubRegions(const MemRegion *Parent) const {
+    Map::const_iterator I = M.find(Parent);
+    return I == M.end() ? NULL : &I->second;
+  }
+
+  bool iterSubRegions(const MemRegion* Parent, Visitor& V) const {
+    Map::const_iterator I = M.find(Parent);
+
+    if (I == M.end())
+      return true;
+
+    Set S = I->second;
+    for (Set::iterator SI=S.begin(),SE=S.end(); SI != SE; ++SI) {
+      if (!V.Visit(Parent, *SI))
+        return false;
+    }
+
+    return true;
+  }
+};
+
+  
+class RegionStoreManager : public StoreManager {
+  const RegionStoreFeatures Features;
+  RegionBindings::Factory RBFactory;
+  
+  typedef llvm::DenseMap<Store, RegionStoreSubRegionMap*> SMCache;
+  SMCache SC;
+
+public:
+  RegionStoreManager(GRStateManager& mgr, const RegionStoreFeatures &f)
+    : StoreManager(mgr),
+      Features(f),
+      RBFactory(mgr.getAllocator()) {}
+
+  virtual ~RegionStoreManager() {
+    for (SMCache::iterator I = SC.begin(), E = SC.end(); I != E; ++I)
+      delete (*I).second;
+  }
+
+  SubRegionMap *getSubRegionMap(Store store) {
+    return getRegionStoreSubRegionMap(store);
+  }
+
+  RegionStoreSubRegionMap *getRegionStoreSubRegionMap(Store store);
+
+  Optional<SVal> getBinding(RegionBindings B, const MemRegion *R);
+  Optional<SVal> getDirectBinding(RegionBindings B, const MemRegion *R);
+  /// getDefaultBinding - Returns an SVal* representing an optional default
+  ///  binding associated with a region and its subregions.
+  Optional<SVal> getDefaultBinding(RegionBindings B, const MemRegion *R);
+  
+  /// setImplicitDefaultValue - Set the default binding for the provided
+  ///  MemRegion to the value implicitly defined for compound literals when
+  ///  the value is not specified.  
+  Store setImplicitDefaultValue(Store store, const MemRegion *R, QualType T);
+
+  /// ArrayToPointer - Emulates the "decay" of an array to a pointer
+  ///  type.  'Array' represents the lvalue of the array being decayed
+  ///  to a pointer, and the returned SVal represents the decayed
+  ///  version of that lvalue (i.e., a pointer to the first element of
+  ///  the array).  This is called by GRExprEngine when evaluating
+  ///  casts from arrays to pointers.
+  SVal ArrayToPointer(Loc Array);
+
+  SVal EvalBinOp(BinaryOperator::Opcode Op,Loc L, NonLoc R, QualType resultTy);
+
+  Store getInitialStore(const LocationContext *InitLoc) {
+    return RBFactory.GetEmptyMap().getRoot();
+  }
+
+  //===-------------------------------------------------------------------===//
+  // Binding values to regions.
+  //===-------------------------------------------------------------------===//
+
+  Store InvalidateRegion(Store store, const MemRegion *R, const Expr *E, 
+                         unsigned Count, InvalidatedSymbols *IS) {
+    return RegionStoreManager::InvalidateRegions(store, &R, &R+1, E, Count, IS);
+  }
+  
+  Store InvalidateRegions(Store store,
+                          const MemRegion * const *Begin,
+                          const MemRegion * const *End,
+                          const Expr *E, unsigned Count,
+                          InvalidatedSymbols *IS);
+
+public:   // Made public for helper classes.
+  
+  void RemoveSubRegionBindings(RegionBindings &B, const MemRegion *R,
+                               RegionStoreSubRegionMap &M);
+
+  RegionBindings Add(RegionBindings B, BindingKey K, SVal V);
+
+  RegionBindings Add(RegionBindings B, const MemRegion *R,
+                     BindingKey::Kind k, SVal V);
+  
+  const SVal *Lookup(RegionBindings B, BindingKey K);
+  const SVal *Lookup(RegionBindings B, const MemRegion *R, BindingKey::Kind k);
+
+  RegionBindings Remove(RegionBindings B, BindingKey K);
+  RegionBindings Remove(RegionBindings B, const MemRegion *R,
+                        BindingKey::Kind k);
+  
+  RegionBindings Remove(RegionBindings B, const MemRegion *R) {
+    return Remove(Remove(B, R, BindingKey::Direct), R, BindingKey::Default);
+  }    
+
+  Store Remove(Store store, BindingKey K);
+
+public: // Part of public interface to class.
+
+  Store Bind(Store store, Loc LV, SVal V);
+
+  Store BindCompoundLiteral(Store store, const CompoundLiteralExpr* CL,
+                            const LocationContext *LC, SVal V);
+
+  Store BindDecl(Store store, const VarRegion *VR, SVal InitVal);
+
+  Store BindDeclWithNoInit(Store store, const VarRegion *) {
+    return store;
+  }
+
+  /// BindStruct - Bind a compound value to a structure.
+  Store BindStruct(Store store, const TypedRegion* R, SVal V);
+
+  Store BindArray(Store store, const TypedRegion* R, SVal V);
+
+  /// KillStruct - Set the entire struct to unknown.
+  Store KillStruct(Store store, const TypedRegion* R);
+
+  Store Remove(Store store, Loc LV);
+  
+
+  //===------------------------------------------------------------------===//
+  // Loading values from regions.
+  //===------------------------------------------------------------------===//
+
+  /// The high level logic for this method is this:
+  /// Retrieve (L)
+  ///   if L has binding
+  ///     return L's binding
+  ///   else if L is in killset
+  ///     return unknown
+  ///   else
+  ///     if L is on stack or heap
+  ///       return undefined
+  ///     else
+  ///       return symbolic
+  SVal Retrieve(Store store, Loc L, QualType T = QualType());
+
+  SVal RetrieveElement(Store store, const ElementRegion *R);
+
+  SVal RetrieveField(Store store, const FieldRegion *R);
+
+  SVal RetrieveObjCIvar(Store store, const ObjCIvarRegion *R);
+
+  SVal RetrieveVar(Store store, const VarRegion *R);
+
+  SVal RetrieveLazySymbol(const TypedRegion *R);
+
+  SVal RetrieveFieldOrElementCommon(Store store, const TypedRegion *R,
+                                    QualType Ty, const MemRegion *superR);
+
+  /// Retrieve the values in a struct and return a CompoundVal, used when doing
+  /// struct copy:
+  /// struct s x, y;
+  /// x = y;
+  /// y's value is retrieved by this method.
+  SVal RetrieveStruct(Store store, const TypedRegion* R);
+
+  SVal RetrieveArray(Store store, const TypedRegion* R);
+
+  /// Get the state and region whose binding this region R corresponds to.
+  std::pair<Store, const MemRegion*>
+  GetLazyBinding(RegionBindings B, const MemRegion *R);
+
+  Store CopyLazyBindings(nonloc::LazyCompoundVal V, Store store,
+                         const TypedRegion *R);
+
+  const ElementRegion *GetElementZeroRegion(const MemRegion *R, QualType T);
+
+  //===------------------------------------------------------------------===//
+  // State pruning.
+  //===------------------------------------------------------------------===//
+
+  /// RemoveDeadBindings - Scans the RegionStore of 'state' for dead values.
+  ///  It returns a new Store with these values removed.
+  Store RemoveDeadBindings(Store store, Stmt* Loc, SymbolReaper& SymReaper,
+                          llvm::SmallVectorImpl<const MemRegion*>& RegionRoots);
+
+  const GRState *EnterStackFrame(const GRState *state,
+                                 const StackFrameContext *frame);
+
+  //===------------------------------------------------------------------===//
+  // Region "extents".
+  //===------------------------------------------------------------------===//
+
+  const GRState *setExtent(const GRState *state,const MemRegion* R,SVal Extent);
+  DefinedOrUnknownSVal getSizeInElements(const GRState *state, 
+                                         const MemRegion* R, QualType EleTy);
+
+  //===------------------------------------------------------------------===//
+  // Utility methods.
+  //===------------------------------------------------------------------===//
+
+  static inline RegionBindings GetRegionBindings(Store store) {
+    return RegionBindings(static_cast<const RegionBindings::TreeTy*>(store));
+  }
+
+  void print(Store store, llvm::raw_ostream& Out, const char* nl,
+             const char *sep);
+
+  void iterBindings(Store store, BindingsHandler& f) {
+    // FIXME: Implement.
+  }
+
+  // FIXME: Remove.
+  BasicValueFactory& getBasicVals() {
+      return StateMgr.getBasicVals();
+  }
+
+  // FIXME: Remove.
+  ASTContext& getContext() { return StateMgr.getContext(); }
+};
+
+} // end anonymous namespace
+
+//===----------------------------------------------------------------------===//
+// RegionStore creation.
+//===----------------------------------------------------------------------===//
+
+StoreManager *clang::CreateRegionStoreManager(GRStateManager& StMgr) {
+  RegionStoreFeatures F = maximal_features_tag();
+  return new RegionStoreManager(StMgr, F);
+}
+
+StoreManager *clang::CreateFieldsOnlyRegionStoreManager(GRStateManager &StMgr) {
+  RegionStoreFeatures F = minimal_features_tag();
+  F.enableFields(true);
+  return new RegionStoreManager(StMgr, F);
+}
+
+void
+RegionStoreSubRegionMap::process(llvm::SmallVectorImpl<const SubRegion*> &WL,
+                                 const SubRegion *R) {
+  const MemRegion *superR = R->getSuperRegion();
+  if (add(superR, R))
+    if (const SubRegion *sr = dyn_cast<SubRegion>(superR))
+      WL.push_back(sr);
+}
+
+RegionStoreSubRegionMap*
+RegionStoreManager::getRegionStoreSubRegionMap(Store store) {
+  RegionBindings B = GetRegionBindings(store);
+  RegionStoreSubRegionMap *M = new RegionStoreSubRegionMap();
+
+  llvm::SmallVector<const SubRegion*, 10> WL;
+
+  for (RegionBindings::iterator I=B.begin(), E=B.end(); I!=E; ++I)
+    if (const SubRegion *R = dyn_cast<SubRegion>(I.getKey().getRegion()))
+      M->process(WL, R);
+
+  // We also need to record in the subregion map "intermediate" regions that
+  // don't have direct bindings but are super regions of those that do.
+  while (!WL.empty()) {
+    const SubRegion *R = WL.back();
+    WL.pop_back();
+    M->process(WL, R);
+  }
+
+  return M;
+}
+
+//===----------------------------------------------------------------------===//
+// Binding invalidation.
+//===----------------------------------------------------------------------===//
+
+void RegionStoreManager::RemoveSubRegionBindings(RegionBindings &B,
+                                                 const MemRegion *R,
+                                                 RegionStoreSubRegionMap &M) {
+  
+  if (const RegionStoreSubRegionMap::Set *S = M.getSubRegions(R))
+    for (RegionStoreSubRegionMap::Set::iterator I = S->begin(), E = S->end();
+         I != E; ++I)
+      RemoveSubRegionBindings(B, *I, M);
+  
+  B = Remove(B, R);
+}
+
+namespace {
+class InvalidateRegionsWorker {
+  typedef BumpVector<BindingKey> RegionCluster;
+  typedef llvm::DenseMap<const MemRegion *, RegionCluster *> ClusterMap;
+  typedef llvm::SmallVector<std::pair<const MemRegion *,RegionCluster*>, 10>
+          WorkList;
+
+  BumpVectorContext BVC;
+  ClusterMap ClusterM;
+  WorkList WL;  
+public:
+  Store InvalidateRegions(RegionStoreManager &RM, Store store,
+                          const MemRegion * const *I,const MemRegion * const *E,
+                          const Expr *Ex, unsigned Count,
+                          StoreManager::InvalidatedSymbols *IS,
+                          ASTContext &Ctx, ValueManager &ValMgr);
+  
+private:
+  void AddToWorkList(BindingKey K);
+  void AddToWorkList(const MemRegion *R);
+  void AddToCluster(BindingKey K);
+  RegionCluster **getCluster(const MemRegion *R);
+};  
+}
+
+void InvalidateRegionsWorker::AddToCluster(BindingKey K) {
+  const MemRegion *R = K.getRegion();
+  const MemRegion *baseR = R->getBaseRegion();
+  RegionCluster **CPtr = getCluster(baseR);
+  assert(*CPtr);
+  (*CPtr)->push_back(K, BVC);
+}
+
+void InvalidateRegionsWorker::AddToWorkList(BindingKey K) {
+  AddToWorkList(K.getRegion());
+}
+
+void InvalidateRegionsWorker::AddToWorkList(const MemRegion *R) {
+  const MemRegion *baseR = R->getBaseRegion();
+  RegionCluster **CPtr = getCluster(baseR);
+  if (RegionCluster *C = *CPtr) {
+    WL.push_back(std::make_pair(baseR, C));
+    *CPtr = NULL;
+  }
+}  
+
+InvalidateRegionsWorker::RegionCluster **
+InvalidateRegionsWorker::getCluster(const MemRegion *R) {
+  RegionCluster *&CRef = ClusterM[R];
+  if (!CRef) {
+    void *Mem = BVC.getAllocator().Allocate<RegionCluster>();
+    CRef = new (Mem) RegionCluster(BVC, 10);
+  }
+  return &CRef;
+}
+
+Store InvalidateRegionsWorker::InvalidateRegions(RegionStoreManager &RM,
+                                                 Store store,
+                                                 const MemRegion * const *I,
+                                                 const MemRegion * const *E,
+                                                 const Expr *Ex, unsigned Count,
+                                           StoreManager::InvalidatedSymbols *IS,
+                                                 ASTContext &Ctx,
+                                                 ValueManager &ValMgr) {
+  RegionBindings B = RegionStoreManager::GetRegionBindings(store);
+
+  // Scan the entire store and make the region clusters.
+  for (RegionBindings::iterator RI = B.begin(), RE = B.end(); RI != RE; ++RI) {
+    AddToCluster(RI.getKey());
+    if (const MemRegion *R = RI.getData().getAsRegion()) {
+      // Generate a cluster, but don't add the region to the cluster
+      // if there aren't any bindings.
+      getCluster(R->getBaseRegion());
+    }
+  }
+  
+  // Add the cluster for I .. E to a worklist.
+  for ( ; I != E; ++I)
+    AddToWorkList(*I);
+
+  while (!WL.empty()) {
+    const MemRegion *baseR;
+    RegionCluster *C;    
+    llvm::tie(baseR, C) = WL.back();
+    WL.pop_back();
+    
+    for (RegionCluster::iterator I = C->begin(), E = C->end(); I != E; ++I) {
+      BindingKey K = *I;
+      
+      // Get the old binding.  Is it a region?  If so, add it to the worklist.
+      if (const SVal *V = RM.Lookup(B, K)) {
+        if (const MemRegion *R = V->getAsRegion())
+          AddToWorkList(R);
+    
+        // A symbol?  Mark it touched by the invalidation.
+        if (IS)
+          if (SymbolRef Sym = V->getAsSymbol())
+            IS->insert(Sym);
+      }
+
+      B = RM.Remove(B, K);
+    }
+    
+    // Now inspect the base region.
+
+    if (IS) {
+      // Symbolic region?  Mark that symbol touched by the invalidation.
+      if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(baseR))
+        IS->insert(SR->getSymbol());
+    }
+    
+    // BlockDataRegion?  If so, invalidate captured variables that are passed
+    // by reference.
+    if (const BlockDataRegion *BR = dyn_cast<BlockDataRegion>(baseR)) {
+      for (BlockDataRegion::referenced_vars_iterator
+           BI = BR->referenced_vars_begin(), BE = BR->referenced_vars_end() ;
+           BI != BE; ++BI) {
+        const VarRegion *VR = *BI;
+        const VarDecl *VD = VR->getDecl();
+        if (VD->getAttr<BlocksAttr>() || !VD->hasLocalStorage())
+          AddToWorkList(VR);
+      }
+      continue;
+    }
+    
+    if (isa<AllocaRegion>(baseR) || isa<SymbolicRegion>(baseR)) {
+      // Invalidate the region by setting its default value to
+      // conjured symbol. The type of the symbol is irrelavant.
+      DefinedOrUnknownSVal V = ValMgr.getConjuredSymbolVal(baseR, Ex, Ctx.IntTy,
+                                                           Count);
+      B = RM.Add(B, baseR, BindingKey::Default, V);
+      continue;
+    }
+    
+    if (!baseR->isBoundable())
+      continue;      
+      
+    const TypedRegion *TR = cast<TypedRegion>(baseR);
+    QualType T = TR->getValueType(Ctx);
+    
+    // Invalidate the binding.      
+    if (const RecordType *RT = T->getAsStructureType()) {
+      const RecordDecl *RD = RT->getDecl()->getDefinition(Ctx);      
+      // No record definition.  There is nothing we can do.
+      if (!RD) {
+        B = RM.Remove(B, baseR);
+        continue;
+      }
+    
+      // Invalidate the region by setting its default value to
+      // conjured symbol. The type of the symbol is irrelavant.
+      DefinedOrUnknownSVal V = ValMgr.getConjuredSymbolVal(baseR, Ex, Ctx.IntTy,
+                                                           Count);
+      B = RM.Add(B, baseR, BindingKey::Default, V);
+      continue;
+    }    
+
+    if (const ArrayType *AT = Ctx.getAsArrayType(T)) {
+      // Set the default value of the array to conjured symbol.
+      DefinedOrUnknownSVal V =
+        ValMgr.getConjuredSymbolVal(baseR, Ex, AT->getElementType(), Count);
+      B = RM.Add(B, baseR, BindingKey::Default, V);
+      continue;
+    }
+      
+    DefinedOrUnknownSVal V = ValMgr.getConjuredSymbolVal(baseR, Ex, T, Count);
+    assert(SymbolManager::canSymbolicate(T) || V.isUnknown());
+    B = RM.Add(B, baseR, BindingKey::Direct, V);
+  }
+
+  // Create a new state with the updated bindings.
+  return B.getRoot();
+}
+
+Store RegionStoreManager::InvalidateRegions(Store store,
+                                            const MemRegion * const *I,
+                                            const MemRegion * const *E,
+                                            const Expr *Ex, unsigned Count,
+                                            InvalidatedSymbols *IS) {
+  InvalidateRegionsWorker W;
+  return W.InvalidateRegions(*this, store, I, E, Ex, Count, IS, getContext(),
+                             StateMgr.getValueManager());
+}
+  
+//===----------------------------------------------------------------------===//
+// Extents for regions.
+//===----------------------------------------------------------------------===//
+
+DefinedOrUnknownSVal RegionStoreManager::getSizeInElements(const GRState *state,
+                                                           const MemRegion *R,
+                                                           QualType EleTy) {
+
+  switch (R->getKind()) {
+    case MemRegion::CXXThisRegionKind:
+      assert(0 && "Cannot get size of 'this' region");      
+    case MemRegion::GenericMemSpaceRegionKind:
+    case MemRegion::StackLocalsSpaceRegionKind:
+    case MemRegion::StackArgumentsSpaceRegionKind:
+    case MemRegion::HeapSpaceRegionKind:
+    case MemRegion::GlobalsSpaceRegionKind:
+    case MemRegion::UnknownSpaceRegionKind:
+      assert(0 && "Cannot index into a MemSpace");
+      return UnknownVal();
+
+    case MemRegion::FunctionTextRegionKind:
+    case MemRegion::BlockTextRegionKind:
+    case MemRegion::BlockDataRegionKind:
+      // Technically this can happen if people do funny things with casts.
+      return UnknownVal();
+
+      // Not yet handled.
+    case MemRegion::AllocaRegionKind:
+    case MemRegion::CompoundLiteralRegionKind:
+    case MemRegion::ElementRegionKind:
+    case MemRegion::FieldRegionKind:
+    case MemRegion::ObjCIvarRegionKind:
+    case MemRegion::CXXObjectRegionKind:
+      return UnknownVal();
+
+    case MemRegion::SymbolicRegionKind: {
+      const SVal *Size = state->get<RegionExtents>(R);
+      if (!Size)
+        return UnknownVal();
+      const nonloc::ConcreteInt *CI = dyn_cast<nonloc::ConcreteInt>(Size);
+      if (!CI)
+        return UnknownVal();
+
+      CharUnits RegionSize = 
+        CharUnits::fromQuantity(CI->getValue().getSExtValue());
+      CharUnits EleSize = getContext().getTypeSizeInChars(EleTy);
+      assert(RegionSize % EleSize == 0);
+
+      return ValMgr.makeIntVal(RegionSize / EleSize, false);
+    }
+
+    case MemRegion::StringRegionKind: {
+      const StringLiteral* Str = cast<StringRegion>(R)->getStringLiteral();
+      // We intentionally made the size value signed because it participates in
+      // operations with signed indices.
+      return ValMgr.makeIntVal(Str->getByteLength()+1, false);
+    }
+
+    case MemRegion::VarRegionKind: {
+      const VarRegion* VR = cast<VarRegion>(R);
+      // Get the type of the variable.
+      QualType T = VR->getDesugaredValueType(getContext());
+
+      // FIXME: Handle variable-length arrays.
+      if (isa<VariableArrayType>(T))
+        return UnknownVal();
+
+      if (const ConstantArrayType* CAT = dyn_cast<ConstantArrayType>(T)) {
+        // return the size as signed integer.
+        return ValMgr.makeIntVal(CAT->getSize(), false);
+      }
+
+      // Clients can use ordinary variables as if they were arrays.  These
+      // essentially are arrays of size 1.
+      return ValMgr.makeIntVal(1, false);
+    }
+  }
+
+  assert(0 && "Unreachable");
+  return UnknownVal();
+}
+
+const GRState *RegionStoreManager::setExtent(const GRState *state,
+                                             const MemRegion *region,
+                                             SVal extent) {
+  return state->set<RegionExtents>(region, extent);
+}
+
+//===----------------------------------------------------------------------===//
+// Location and region casting.
+//===----------------------------------------------------------------------===//
+
+/// ArrayToPointer - Emulates the "decay" of an array to a pointer
+///  type.  'Array' represents the lvalue of the array being decayed
+///  to a pointer, and the returned SVal represents the decayed
+///  version of that lvalue (i.e., a pointer to the first element of
+///  the array).  This is called by GRExprEngine when evaluating casts
+///  from arrays to pointers.
+SVal RegionStoreManager::ArrayToPointer(Loc Array) {
+  if (!isa<loc::MemRegionVal>(Array))
+    return UnknownVal();
+
+  const MemRegion* R = cast<loc::MemRegionVal>(&Array)->getRegion();
+  const TypedRegion* ArrayR = dyn_cast<TypedRegion>(R);
+
+  if (!ArrayR)
+    return UnknownVal();
+
+  // Strip off typedefs from the ArrayRegion's ValueType.
+  QualType T = ArrayR->getValueType(getContext()).getDesugaredType();
+  ArrayType *AT = cast<ArrayType>(T);
+  T = AT->getElementType();
+
+  SVal ZeroIdx = ValMgr.makeZeroArrayIndex();
+  return loc::MemRegionVal(MRMgr.getElementRegion(T, ZeroIdx, ArrayR,
+                                                  getContext()));
+}
+
+//===----------------------------------------------------------------------===//
+// Pointer arithmetic.
+//===----------------------------------------------------------------------===//
+
+SVal RegionStoreManager::EvalBinOp(BinaryOperator::Opcode Op, Loc L, NonLoc R,
+                                   QualType resultTy) {
+  // Assume the base location is MemRegionVal.
+  if (!isa<loc::MemRegionVal>(L))
+    return UnknownVal();
+
+  const MemRegion* MR = cast<loc::MemRegionVal>(L).getRegion();
+  const ElementRegion *ER = 0;
+
+  switch (MR->getKind()) {
+    case MemRegion::SymbolicRegionKind: {
+      const SymbolicRegion *SR = cast<SymbolicRegion>(MR);
+      SymbolRef Sym = SR->getSymbol();
+      QualType T = Sym->getType(getContext());
+      QualType EleTy;
+
+      if (const PointerType *PT = T->getAs<PointerType>())
+        EleTy = PT->getPointeeType();
+      else
+        EleTy = T->getAs<ObjCObjectPointerType>()->getPointeeType();
+
+      SVal ZeroIdx = ValMgr.makeZeroArrayIndex();
+      ER = MRMgr.getElementRegion(EleTy, ZeroIdx, SR, getContext());
+      break;
+    }
+    case MemRegion::AllocaRegionKind: {
+      const AllocaRegion *AR = cast<AllocaRegion>(MR);
+      QualType T = getContext().CharTy; // Create an ElementRegion of bytes.
+      QualType EleTy = T->getAs<PointerType>()->getPointeeType();
+      SVal ZeroIdx = ValMgr.makeZeroArrayIndex();
+      ER = MRMgr.getElementRegion(EleTy, ZeroIdx, AR, getContext());
+      break;
+    }
+
+    case MemRegion::ElementRegionKind: {
+      ER = cast<ElementRegion>(MR);
+      break;
+    }
+
+    // Not yet handled.
+    case MemRegion::VarRegionKind:
+    case MemRegion::StringRegionKind: {
+      
+    }
+    // Fall-through.
+    case MemRegion::CompoundLiteralRegionKind:
+    case MemRegion::FieldRegionKind:
+    case MemRegion::ObjCIvarRegionKind:
+    case MemRegion::CXXObjectRegionKind:
+      return UnknownVal();
+
+    case MemRegion::FunctionTextRegionKind:
+    case MemRegion::BlockTextRegionKind:
+    case MemRegion::BlockDataRegionKind:
+      // Technically this can happen if people do funny things with casts.
+      return UnknownVal();
+
+    case MemRegion::CXXThisRegionKind:
+      assert(0 &&
+             "Cannot perform pointer arithmetic on implicit argument 'this'");
+    case MemRegion::GenericMemSpaceRegionKind:
+    case MemRegion::StackLocalsSpaceRegionKind:
+    case MemRegion::StackArgumentsSpaceRegionKind:
+    case MemRegion::HeapSpaceRegionKind:
+    case MemRegion::GlobalsSpaceRegionKind:
+    case MemRegion::UnknownSpaceRegionKind:
+      assert(0 && "Cannot perform pointer arithmetic on a MemSpace");
+      return UnknownVal();
+  }
+
+  SVal Idx = ER->getIndex();
+  nonloc::ConcreteInt* Base = dyn_cast<nonloc::ConcreteInt>(&Idx);
+
+  // For now, only support:
+  //  (a) concrete integer indices that can easily be resolved
+  //  (b) 0 + symbolic index
+  if (Base) {
+    if (nonloc::ConcreteInt *Offset = dyn_cast<nonloc::ConcreteInt>(&R)) {
+      // FIXME: Should use SValuator here.
+      SVal NewIdx =
+        Base->evalBinOp(ValMgr, Op,
+                cast<nonloc::ConcreteInt>(ValMgr.convertToArrayIndex(*Offset)));
+      const MemRegion* NewER =
+        MRMgr.getElementRegion(ER->getElementType(), NewIdx,
+                               ER->getSuperRegion(), getContext());
+      return ValMgr.makeLoc(NewER);
+    }    
+    if (0 == Base->getValue()) {
+      const MemRegion* NewER =
+        MRMgr.getElementRegion(ER->getElementType(), R,
+                               ER->getSuperRegion(), getContext());
+      return ValMgr.makeLoc(NewER);      
+    }    
+  }
+
+  return UnknownVal();
+}
+
+//===----------------------------------------------------------------------===//
+// Loading values from regions.
+//===----------------------------------------------------------------------===//
+
+Optional<SVal> RegionStoreManager::getDirectBinding(RegionBindings B, 
+                                                 const MemRegion *R) {
+  if (const SVal *V = Lookup(B, R, BindingKey::Direct))
+    return *V;  
+
+  return Optional<SVal>();
+}
+
+Optional<SVal> RegionStoreManager::getDefaultBinding(RegionBindings B,
+                                                     const MemRegion *R) {
+  if (R->isBoundable())
+    if (const TypedRegion *TR = dyn_cast<TypedRegion>(R))
+      if (TR->getValueType(getContext())->isUnionType())
+        return UnknownVal();
+
+  if (const SVal *V = Lookup(B, R, BindingKey::Default))
+    return *V;
+
+  return Optional<SVal>();
+}
+
+Optional<SVal> RegionStoreManager::getBinding(RegionBindings B,
+                                              const MemRegion *R) {
+  
+  if (Optional<SVal> V = getDirectBinding(B, R))
+    return V;
+  
+  return getDefaultBinding(B, R);
+}
+
+static bool IsReinterpreted(QualType RTy, QualType UsedTy, ASTContext &Ctx) {
+  RTy = Ctx.getCanonicalType(RTy);
+  UsedTy = Ctx.getCanonicalType(UsedTy);
+
+  if (RTy == UsedTy)
+    return false;
+
+
+  // Recursively check the types.  We basically want to see if a pointer value
+  // is ever reinterpreted as a non-pointer, e.g. void** and intptr_t*
+  // represents a reinterpretation.
+  if (Loc::IsLocType(RTy) && Loc::IsLocType(UsedTy)) {
+    const PointerType *PRTy = RTy->getAs<PointerType>();
+    const PointerType *PUsedTy = UsedTy->getAs<PointerType>();
+
+    return PUsedTy && PRTy &&
+           IsReinterpreted(PRTy->getPointeeType(),
+                           PUsedTy->getPointeeType(), Ctx);
+  }
+
+  return true;
+}
+
+const ElementRegion *
+RegionStoreManager::GetElementZeroRegion(const MemRegion *R, QualType T) {
+  ASTContext &Ctx = getContext();
+  SVal idx = ValMgr.makeZeroArrayIndex();
+  assert(!T.isNull());
+  return MRMgr.getElementRegion(T, idx, R, Ctx);
+}
+
+SVal RegionStoreManager::Retrieve(Store store, Loc L, QualType T) {
+  assert(!isa<UnknownVal>(L) && "location unknown");
+  assert(!isa<UndefinedVal>(L) && "location undefined");
+  
+  // FIXME: Is this even possible?  Shouldn't this be treated as a null
+  //  dereference at a higher level?
+  if (isa<loc::ConcreteInt>(L))
+    return UndefinedVal();
+  
+  const MemRegion *MR = cast<loc::MemRegionVal>(L).getRegion();
+
+  if (isa<AllocaRegion>(MR) || isa<SymbolicRegion>(MR))
+    MR = GetElementZeroRegion(MR, T);
+
+  if (isa<CodeTextRegion>(MR))
+    return UnknownVal();
+
+  // FIXME: Perhaps this method should just take a 'const MemRegion*' argument
+  //  instead of 'Loc', and have the other Loc cases handled at a higher level.
+  const TypedRegion *R = cast<TypedRegion>(MR);
+  QualType RTy = R->getValueType(getContext());
+
+  // FIXME: We should eventually handle funny addressing.  e.g.:
+  //
+  //   int x = ...;
+  //   int *p = &x;
+  //   char *q = (char*) p;
+  //   char c = *q;  // returns the first byte of 'x'.
+  //
+  // Such funny addressing will occur due to layering of regions.
+
+#if 0
+  ASTContext &Ctx = getContext();
+  if (!T.isNull() && IsReinterpreted(RTy, T, Ctx)) {
+    SVal ZeroIdx = ValMgr.makeZeroArrayIndex();
+    R = MRMgr.getElementRegion(T, ZeroIdx, R, Ctx);
+    RTy = T;
+    assert(Ctx.getCanonicalType(RTy) ==
+           Ctx.getCanonicalType(R->getValueType(Ctx)));
+  }
+#endif
+
+  if (RTy->isStructureType())
+    return RetrieveStruct(store, R);
+
+  // FIXME: Handle unions.
+  if (RTy->isUnionType())
+    return UnknownVal();
+
+  if (RTy->isArrayType())
+    return RetrieveArray(store, R);
+
+  // FIXME: handle Vector types.
+  if (RTy->isVectorType())
+    return UnknownVal();
+
+  if (const FieldRegion* FR = dyn_cast<FieldRegion>(R))
+    return CastRetrievedVal(RetrieveField(store, FR), FR, T, false);
+
+  if (const ElementRegion* ER = dyn_cast<ElementRegion>(R)) {
+    // FIXME: Here we actually perform an implicit conversion from the loaded
+    // value to the element type.  Eventually we want to compose these values
+    // more intelligently.  For example, an 'element' can encompass multiple
+    // bound regions (e.g., several bound bytes), or could be a subset of
+    // a larger value.
+    return CastRetrievedVal(RetrieveElement(store, ER), ER, T, false);
+  }    
+
+  if (const ObjCIvarRegion *IVR = dyn_cast<ObjCIvarRegion>(R)) {
+    // FIXME: Here we actually perform an implicit conversion from the loaded
+    // value to the ivar type.  What we should model is stores to ivars
+    // that blow past the extent of the ivar.  If the address of the ivar is
+    // reinterpretted, it is possible we stored a different value that could
+    // fit within the ivar.  Either we need to cast these when storing them
+    // or reinterpret them lazily (as we do here).
+    return CastRetrievedVal(RetrieveObjCIvar(store, IVR), IVR, T, false);
+  }
+
+  if (const VarRegion *VR = dyn_cast<VarRegion>(R)) {
+    // FIXME: Here we actually perform an implicit conversion from the loaded
+    // value to the variable type.  What we should model is stores to variables
+    // that blow past the extent of the variable.  If the address of the
+    // variable is reinterpretted, it is possible we stored a different value
+    // that could fit within the variable.  Either we need to cast these when
+    // storing them or reinterpret them lazily (as we do here).    
+    return CastRetrievedVal(RetrieveVar(store, VR), VR, T, false);
+  }
+
+  RegionBindings B = GetRegionBindings(store);
+  const SVal *V = Lookup(B, R, BindingKey::Direct);
+
+  // Check if the region has a binding.
+  if (V)
+    return *V;
+
+  // The location does not have a bound value.  This means that it has
+  // the value it had upon its creation and/or entry to the analyzed
+  // function/method.  These are either symbolic values or 'undefined'.
+  if (R->hasStackNonParametersStorage()) {
+    // All stack variables are considered to have undefined values
+    // upon creation.  All heap allocated blocks are considered to
+    // have undefined values as well unless they are explicitly bound
+    // to specific values.
+    return UndefinedVal();
+  }
+
+  // All other values are symbolic.
+  return ValMgr.getRegionValueSymbolVal(R, RTy);
+}
+
+std::pair<Store, const MemRegion *>
+RegionStoreManager::GetLazyBinding(RegionBindings B, const MemRegion *R) {
+  if (Optional<SVal> OV = getDirectBinding(B, R))
+    if (const nonloc::LazyCompoundVal *V =
+        dyn_cast<nonloc::LazyCompoundVal>(OV.getPointer()))
+      return std::make_pair(V->getStore(), V->getRegion());
+
+  if (const ElementRegion *ER = dyn_cast<ElementRegion>(R)) {
+    const std::pair<Store, const MemRegion *> &X =
+      GetLazyBinding(B, ER->getSuperRegion());
+
+    if (X.second)
+      return std::make_pair(X.first,
+                            MRMgr.getElementRegionWithSuper(ER, X.second));
+  }
+  else if (const FieldRegion *FR = dyn_cast<FieldRegion>(R)) {
+    const std::pair<Store, const MemRegion *> &X =
+      GetLazyBinding(B, FR->getSuperRegion());
+
+    if (X.second)
+      return std::make_pair(X.first,
+                            MRMgr.getFieldRegionWithSuper(FR, X.second));
+  }
+  // The NULL MemRegion indicates an non-existent lazy binding. A NULL Store is 
+  // possible for a valid lazy binding.
+  return std::make_pair((Store) 0, (const MemRegion *) 0);
+}
+
+SVal RegionStoreManager::RetrieveElement(Store store,
+                                         const ElementRegion* R) {
+  // Check if the region has a binding.
+  RegionBindings B = GetRegionBindings(store);
+  if (Optional<SVal> V = getDirectBinding(B, R))
+    return *V;
+
+  const MemRegion* superR = R->getSuperRegion();
+
+  // Check if the region is an element region of a string literal.
+  if (const StringRegion *StrR=dyn_cast<StringRegion>(superR)) {
+    // FIXME: Handle loads from strings where the literal is treated as 
+    // an integer, e.g., *((unsigned int*)"hello")
+    ASTContext &Ctx = getContext();
+    QualType T = Ctx.getAsArrayType(StrR->getValueType(Ctx))->getElementType();
+    if (T != Ctx.getCanonicalType(R->getElementType()))
+      return UnknownVal();
+    
+    const StringLiteral *Str = StrR->getStringLiteral();
+    SVal Idx = R->getIndex();
+    if (nonloc::ConcreteInt *CI = dyn_cast<nonloc::ConcreteInt>(&Idx)) {
+      int64_t i = CI->getValue().getSExtValue();
+      int64_t byteLength = Str->getByteLength();
+      if (i > byteLength) {
+        // Buffer overflow checking in GRExprEngine should handle this case,
+        // but we shouldn't rely on it to not overflow here if that checking
+        // is disabled.
+        return UnknownVal();
+      }
+      char c = (i == byteLength) ? '\0' : Str->getStrData()[i];
+      return ValMgr.makeIntVal(c, T);
+    }
+  }
+
+  // Check if the immediate super region has a direct binding.
+  if (Optional<SVal> V = getDirectBinding(B, superR)) {
+    if (SymbolRef parentSym = V->getAsSymbol())
+      return ValMgr.getDerivedRegionValueSymbolVal(parentSym, R);
+
+    if (V->isUnknownOrUndef())
+      return *V;
+
+    // Handle LazyCompoundVals for the immediate super region.  Other cases
+    // are handled in 'RetrieveFieldOrElementCommon'.
+    if (const nonloc::LazyCompoundVal *LCV =
+        dyn_cast<nonloc::LazyCompoundVal>(V)) {
+
+      R = MRMgr.getElementRegionWithSuper(R, LCV->getRegion());
+      return RetrieveElement(LCV->getStore(), R);
+    }
+
+    // Other cases: give up.
+    return UnknownVal();
+  }
+    
+  return RetrieveFieldOrElementCommon(store, R, R->getElementType(), superR);
+}
+
+SVal RegionStoreManager::RetrieveField(Store store,
+                                       const FieldRegion* R) {
+
+  // Check if the region has a binding.
+  RegionBindings B = GetRegionBindings(store);
+  if (Optional<SVal> V = getDirectBinding(B, R))
+    return *V;
+
+  QualType Ty = R->getValueType(getContext());
+  return RetrieveFieldOrElementCommon(store, R, Ty, R->getSuperRegion());
+}
+
+SVal RegionStoreManager::RetrieveFieldOrElementCommon(Store store,
+                                                      const TypedRegion *R,
+                                                      QualType Ty,
+                                                      const MemRegion *superR) {
+
+  // At this point we have already checked in either RetrieveElement or
+  // RetrieveField if 'R' has a direct binding.
+
+  RegionBindings B = GetRegionBindings(store);
+
+  while (superR) {
+    if (const Optional<SVal> &D = getDefaultBinding(B, superR)) {
+      if (SymbolRef parentSym = D->getAsSymbol())
+        return ValMgr.getDerivedRegionValueSymbolVal(parentSym, R);
+
+      if (D->isZeroConstant())
+        return ValMgr.makeZeroVal(Ty);
+
+      if (D->isUnknown())
+        return *D;
+
+      assert(0 && "Unknown default value");
+    }
+
+    // If our super region is a field or element itself, walk up the region
+    // hierarchy to see if there is a default value installed in an ancestor.
+    if (isa<FieldRegion>(superR) || isa<ElementRegion>(superR)) {
+      superR = cast<SubRegion>(superR)->getSuperRegion();
+      continue;
+    }
+
+    break;
+  }
+
+  // Lazy binding?
+  Store lazyBindingStore = NULL;
+  const MemRegion *lazyBindingRegion = NULL;
+  llvm::tie(lazyBindingStore, lazyBindingRegion) = GetLazyBinding(B, R);
+
+  if (lazyBindingRegion) {
+    if (const ElementRegion *ER = dyn_cast<ElementRegion>(lazyBindingRegion))
+      return RetrieveElement(lazyBindingStore, ER);
+    return RetrieveField(lazyBindingStore,
+                         cast<FieldRegion>(lazyBindingRegion));
+  }
+
+  if (R->hasStackNonParametersStorage()) {
+    if (isa<ElementRegion>(R)) {
+      // Currently we don't reason specially about Clang-style vectors.  Check
+      // if superR is a vector and if so return Unknown.
+      if (const TypedRegion *typedSuperR = dyn_cast<TypedRegion>(superR)) {
+        if (typedSuperR->getValueType(getContext())->isVectorType())
+          return UnknownVal();
+      }
+    }
+
+    return UndefinedVal();
+  }
+
+  // All other values are symbolic.
+  return ValMgr.getRegionValueSymbolVal(R, Ty);
+}
+
+SVal RegionStoreManager::RetrieveObjCIvar(Store store, const ObjCIvarRegion* R){
+
+    // Check if the region has a binding.
+  RegionBindings B = GetRegionBindings(store);
+
+  if (Optional<SVal> V = getDirectBinding(B, R))
+    return *V;
+
+  const MemRegion *superR = R->getSuperRegion();
+
+  // Check if the super region has a default binding.
+  if (Optional<SVal> V = getDefaultBinding(B, superR)) {
+    if (SymbolRef parentSym = V->getAsSymbol())
+      return ValMgr.getDerivedRegionValueSymbolVal(parentSym, R);
+
+    // Other cases: give up.
+    return UnknownVal();
+  }
+
+  return RetrieveLazySymbol(R);
+}
+
+SVal RegionStoreManager::RetrieveVar(Store store, const VarRegion *R) {
+
+  // Check if the region has a binding.
+  RegionBindings B = GetRegionBindings(store);
+
+  if (Optional<SVal> V = getDirectBinding(B, R))
+    return *V;
+
+  // Lazily derive a value for the VarRegion.
+  const VarDecl *VD = R->getDecl();
+  QualType T = VD->getType();
+  const MemSpaceRegion *MS = R->getMemorySpace();
+  
+  if (isa<UnknownSpaceRegion>(MS) || 
+      isa<StackArgumentsSpaceRegion>(MS))
+    return ValMgr.getRegionValueSymbolVal(R, T);
+
+  if (isa<GlobalsSpaceRegion>(MS)) {
+    if (VD->isFileVarDecl())
+      return ValMgr.getRegionValueSymbolVal(R, T);
+
+    if (T->isIntegerType())
+      return ValMgr.makeIntVal(0, T);
+    if (T->isPointerType())
+      return ValMgr.makeNull();
+
+    return UnknownVal();    
+  }
+    
+  return UndefinedVal();
+}
+
+SVal RegionStoreManager::RetrieveLazySymbol(const TypedRegion *R) {
+
+  QualType valTy = R->getValueType(getContext());
+
+  // All other values are symbolic.
+  return ValMgr.getRegionValueSymbolVal(R, valTy);
+}
+
+SVal RegionStoreManager::RetrieveStruct(Store store, const TypedRegion* R) {
+  QualType T = R->getValueType(getContext());
+  assert(T->isStructureType());
+
+  const RecordType* RT = T->getAsStructureType();
+  RecordDecl* RD = RT->getDecl();
+  assert(RD->isDefinition());
+  (void)RD;
+#if USE_EXPLICIT_COMPOUND
+  llvm::ImmutableList<SVal> StructVal = getBasicVals().getEmptySValList();
+
+  // FIXME: We shouldn't use a std::vector.  If RecordDecl doesn't have a
+  // reverse iterator, we should implement one.
+  std::vector<FieldDecl *> Fields(RD->field_begin(), RD->field_end());
+
+  for (std::vector<FieldDecl *>::reverse_iterator Field = Fields.rbegin(),
+                                               FieldEnd = Fields.rend();
+       Field != FieldEnd; ++Field) {
+    FieldRegion* FR = MRMgr.getFieldRegion(*Field, R);
+    QualType FTy = (*Field)->getType();
+    SVal FieldValue = Retrieve(store, loc::MemRegionVal(FR), FTy).getSVal();
+    StructVal = getBasicVals().consVals(FieldValue, StructVal);
+  }
+
+  return ValMgr.makeCompoundVal(T, StructVal);
+#else
+  return ValMgr.makeLazyCompoundVal(store, R);
+#endif
+}
+
+SVal RegionStoreManager::RetrieveArray(Store store, const TypedRegion * R) {
+#if USE_EXPLICIT_COMPOUND
+  QualType T = R->getValueType(getContext());
+  ConstantArrayType* CAT = cast<ConstantArrayType>(T.getTypePtr());
+
+  llvm::ImmutableList<SVal> ArrayVal = getBasicVals().getEmptySValList();
+  uint64_t size = CAT->getSize().getZExtValue();
+  for (uint64_t i = 0; i < size; ++i) {
+    SVal Idx = ValMgr.makeArrayIndex(i);
+    ElementRegion* ER = MRMgr.getElementRegion(CAT->getElementType(), Idx, R,
+                                               getContext());
+    QualType ETy = ER->getElementType();
+    SVal ElementVal = Retrieve(store, loc::MemRegionVal(ER), ETy).getSVal();
+    ArrayVal = getBasicVals().consVals(ElementVal, ArrayVal);
+  }
+
+  return ValMgr.makeCompoundVal(T, ArrayVal);
+#else
+  assert(isa<ConstantArrayType>(R->getValueType(getContext())));
+  return ValMgr.makeLazyCompoundVal(store, R);
+#endif
+}
+
+//===----------------------------------------------------------------------===//
+// Binding values to regions.
+//===----------------------------------------------------------------------===//
+
+Store RegionStoreManager::Remove(Store store, Loc L) {
+  if (isa<loc::MemRegionVal>(L))
+    if (const MemRegion* R = cast<loc::MemRegionVal>(L).getRegion())
+      return Remove(GetRegionBindings(store), R).getRoot();
+
+  return store;
+}
+
+Store RegionStoreManager::Bind(Store store, Loc L, SVal V) {
+  if (isa<loc::ConcreteInt>(L))
+    return store;
+
+  // If we get here, the location should be a region.
+  const MemRegion *R = cast<loc::MemRegionVal>(L).getRegion();
+
+  // Check if the region is a struct region.
+  if (const TypedRegion* TR = dyn_cast<TypedRegion>(R))
+    if (TR->getValueType(getContext())->isStructureType())
+      return BindStruct(store, TR, V);
+
+  // Special case: the current region represents a cast and it and the super
+  // region both have pointer types or intptr_t types.  If so, perform the
+  // bind to the super region.
+  // This is needed to support OSAtomicCompareAndSwap and friends or other
+  // loads that treat integers as pointers and vis versa.
+  if (const ElementRegion *ER = dyn_cast<ElementRegion>(R)) {
+    if (ER->getIndex().isZeroConstant()) {
+      if (const TypedRegion *superR =
+            dyn_cast<TypedRegion>(ER->getSuperRegion())) {
+        ASTContext &Ctx = getContext();
+        QualType superTy = superR->getValueType(Ctx);
+        QualType erTy = ER->getValueType(Ctx);
+
+        if (IsAnyPointerOrIntptr(superTy, Ctx) &&
+            IsAnyPointerOrIntptr(erTy, Ctx)) {
+          V = ValMgr.getSValuator().EvalCast(V, superTy, erTy);
+          return Bind(store, loc::MemRegionVal(superR), V);
+        }
+        // For now, just invalidate the fields of the struct/union/class.
+        // FIXME: Precisely handle the fields of the record.
+        if (superTy->isRecordType())
+          return InvalidateRegion(store, superR, NULL, 0, NULL);
+      }
+    }
+  }
+  else if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(R)) {
+    // Binding directly to a symbolic region should be treated as binding
+    // to element 0.
+    QualType T = SR->getSymbol()->getType(getContext());
+    
+    // FIXME: Is this the right way to handle symbols that are references?
+    if (const PointerType *PT = T->getAs<PointerType>())
+      T = PT->getPointeeType();
+    else
+      T = T->getAs<ReferenceType>()->getPointeeType();
+
+    R = GetElementZeroRegion(SR, T);
+  }
+
+  // Perform the binding.
+  RegionBindings B = GetRegionBindings(store);
+  return Add(B, R, BindingKey::Direct, V).getRoot();
+}
+
+Store RegionStoreManager::BindDecl(Store store, const VarRegion *VR, 
+                                   SVal InitVal) {
+
+  QualType T = VR->getDecl()->getType();
+
+  if (T->isArrayType())
+    return BindArray(store, VR, InitVal);
+  if (T->isStructureType())
+    return BindStruct(store, VR, InitVal);
+
+  return Bind(store, ValMgr.makeLoc(VR), InitVal);
+}
+
+// FIXME: this method should be merged into Bind().
+Store RegionStoreManager::BindCompoundLiteral(Store store,
+                                              const CompoundLiteralExpr *CL,
+                                              const LocationContext *LC,
+                                              SVal V) {
+  return Bind(store, loc::MemRegionVal(MRMgr.getCompoundLiteralRegion(CL, LC)),
+              V);
+}
+
+Store RegionStoreManager::setImplicitDefaultValue(Store store,
+                                                  const MemRegion *R,
+                                                  QualType T) {
+  RegionBindings B = GetRegionBindings(store);
+  SVal V;
+
+  if (Loc::IsLocType(T))
+    V = ValMgr.makeNull();
+  else if (T->isIntegerType())
+    V = ValMgr.makeZeroVal(T);
+  else if (T->isStructureType() || T->isArrayType()) {
+    // Set the default value to a zero constant when it is a structure
+    // or array.  The type doesn't really matter.
+    V = ValMgr.makeZeroVal(ValMgr.getContext().IntTy);
+  }
+  else {
+    return store;
+  }
+
+  return Add(B, R, BindingKey::Default, V).getRoot();
+}
+  
+Store RegionStoreManager::BindArray(Store store, const TypedRegion* R, 
+                                    SVal Init) {
+  
+  ASTContext &Ctx = getContext();
+  const ArrayType *AT =
+    cast<ArrayType>(Ctx.getCanonicalType(R->getValueType(Ctx)));
+  QualType ElementTy = AT->getElementType();  
+  Optional<uint64_t> Size;
+  
+  if (const ConstantArrayType* CAT = dyn_cast<ConstantArrayType>(AT))
+    Size = CAT->getSize().getZExtValue();
+    
+  // Check if the init expr is a StringLiteral.
+  if (isa<loc::MemRegionVal>(Init)) {
+    const MemRegion* InitR = cast<loc::MemRegionVal>(Init).getRegion();
+    const StringLiteral* S = cast<StringRegion>(InitR)->getStringLiteral();
+    const char* str = S->getStrData();
+    unsigned len = S->getByteLength();
+    unsigned j = 0;
+
+    // Copy bytes from the string literal into the target array. Trailing bytes
+    // in the array that are not covered by the string literal are initialized
+    // to zero.
+    
+    // We assume that string constants are bound to
+    // constant arrays.
+    uint64_t size = Size.getValue();
+    
+    for (uint64_t i = 0; i < size; ++i, ++j) {
+      if (j >= len)
+        break;
+
+      SVal Idx = ValMgr.makeArrayIndex(i);
+      const ElementRegion* ER = MRMgr.getElementRegion(ElementTy, Idx, R,
+                                                       getContext());
+
+      SVal V = ValMgr.makeIntVal(str[j], sizeof(char)*8, true);
+      store = Bind(store, loc::MemRegionVal(ER), V);
+    }
+
+    return store;
+  }
+
+  // Handle lazy compound values.
+  if (nonloc::LazyCompoundVal *LCV = dyn_cast<nonloc::LazyCompoundVal>(&Init))
+    return CopyLazyBindings(*LCV, store, R);
+
+  // Remaining case: explicit compound values.
+  
+  if (Init.isUnknown())
+    return setImplicitDefaultValue(store, R, ElementTy);    
+  
+  nonloc::CompoundVal& CV = cast<nonloc::CompoundVal>(Init);
+  nonloc::CompoundVal::iterator VI = CV.begin(), VE = CV.end();
+  uint64_t i = 0;
+
+  for (; Size.hasValue() ? i < Size.getValue() : true ; ++i, ++VI) {
+    // The init list might be shorter than the array length.
+    if (VI == VE)
+      break;
+
+    SVal Idx = ValMgr.makeArrayIndex(i);
+    const ElementRegion *ER = MRMgr.getElementRegion(ElementTy, Idx, R, getContext());
+
+    if (ElementTy->isStructureType())
+      store = BindStruct(store, ER, *VI);
+    else
+      store = Bind(store, ValMgr.makeLoc(ER), *VI);
+  }
+
+  // If the init list is shorter than the array length, set the
+  // array default value.
+  if (Size.hasValue() && i < Size.getValue())
+    store = setImplicitDefaultValue(store, R, ElementTy);
+
+  return store;
+}
+
+Store RegionStoreManager::BindStruct(Store store, const TypedRegion* R,
+                                     SVal V) {
+
+  if (!Features.supportsFields())
+    return store;
+
+  QualType T = R->getValueType(getContext());
+  assert(T->isStructureType());
+
+  const RecordType* RT = T->getAs<RecordType>();
+  RecordDecl* RD = RT->getDecl();
+
+  if (!RD->isDefinition())
+    return store;
+
+  // Handle lazy compound values.
+  if (const nonloc::LazyCompoundVal *LCV=dyn_cast<nonloc::LazyCompoundVal>(&V))
+    return CopyLazyBindings(*LCV, store, R);
+
+  // We may get non-CompoundVal accidentally due to imprecise cast logic.
+  // Ignore them and kill the field values.
+  if (V.isUnknown() || !isa<nonloc::CompoundVal>(V))
+    return KillStruct(store, R);
+
+  nonloc::CompoundVal& CV = cast<nonloc::CompoundVal>(V);
+  nonloc::CompoundVal::iterator VI = CV.begin(), VE = CV.end();
+
+  RecordDecl::field_iterator FI, FE;
+
+  for (FI = RD->field_begin(), FE = RD->field_end(); FI != FE; ++FI, ++VI) {
+
+    if (VI == VE)
+      break;
+
+    QualType FTy = (*FI)->getType();
+    const FieldRegion* FR = MRMgr.getFieldRegion(*FI, R);
+
+    if (FTy->isArrayType())
+      store = BindArray(store, FR, *VI);
+    else if (FTy->isStructureType())
+      store = BindStruct(store, FR, *VI);
+    else
+      store = Bind(store, ValMgr.makeLoc(FR), *VI);
+  }
+
+  // There may be fewer values in the initialize list than the fields of struct.
+  if (FI != FE) {
+    RegionBindings B = GetRegionBindings(store);
+    B = Add(B, R, BindingKey::Default, ValMgr.makeIntVal(0, false));
+    store = B.getRoot();
+  }
+
+  return store;
+}
+
+Store RegionStoreManager::KillStruct(Store store, const TypedRegion* R) {
+  RegionBindings B = GetRegionBindings(store);
+  llvm::OwningPtr<RegionStoreSubRegionMap>
+    SubRegions(getRegionStoreSubRegionMap(store));
+  RemoveSubRegionBindings(B, R, *SubRegions);
+
+  // Set the default value of the struct region to "unknown".
+  return Add(B, R, BindingKey::Default, UnknownVal()).getRoot();
+}
+
+Store RegionStoreManager::CopyLazyBindings(nonloc::LazyCompoundVal V,
+                                           Store store, const TypedRegion *R) {
+
+  // Nuke the old bindings stemming from R.
+  RegionBindings B = GetRegionBindings(store);
+
+  llvm::OwningPtr<RegionStoreSubRegionMap>
+    SubRegions(getRegionStoreSubRegionMap(store));
+
+  // B and DVM are updated after the call to RemoveSubRegionBindings.
+  RemoveSubRegionBindings(B, R, *SubRegions.get());
+
+  // Now copy the bindings.  This amounts to just binding 'V' to 'R'.  This
+  // results in a zero-copy algorithm.
+  return Add(B, R, BindingKey::Direct, V).getRoot();
+}
+
+//===----------------------------------------------------------------------===//
+// "Raw" retrievals and bindings.
+//===----------------------------------------------------------------------===//
+
+BindingKey BindingKey::Make(const MemRegion *R, Kind k) {
+  if (const ElementRegion *ER = dyn_cast<ElementRegion>(R)) {
+    const RegionRawOffset &O = ER->getAsRawOffset();
+    
+    if (O.getRegion())
+      return BindingKey(O.getRegion(), O.getByteOffset(), k);
+    
+    // FIXME: There are some ElementRegions for which we cannot compute
+    // raw offsets yet, including regions with symbolic offsets.
+  }
+  
+  return BindingKey(R, 0, k);
+}
+
+RegionBindings RegionStoreManager::Add(RegionBindings B, BindingKey K, SVal V) {
+  return RBFactory.Add(B, K, V);
+}
+
+RegionBindings RegionStoreManager::Add(RegionBindings B, const MemRegion *R,
+                                       BindingKey::Kind k, SVal V) {
+  return Add(B, BindingKey::Make(R, k), V);
+}
+
+const SVal *RegionStoreManager::Lookup(RegionBindings B, BindingKey K) {
+  return B.lookup(K);
+}
+
+const SVal *RegionStoreManager::Lookup(RegionBindings B,
+                                       const MemRegion *R,
+                                       BindingKey::Kind k) {
+  return Lookup(B, BindingKey::Make(R, k));
+}
+
+RegionBindings RegionStoreManager::Remove(RegionBindings B, BindingKey K) {
+  return RBFactory.Remove(B, K);
+}
+
+RegionBindings RegionStoreManager::Remove(RegionBindings B, const MemRegion *R,
+                                          BindingKey::Kind k){
+  return Remove(B, BindingKey::Make(R, k));
+}
+
+Store RegionStoreManager::Remove(Store store, BindingKey K) {
+  RegionBindings B = GetRegionBindings(store);
+  return Remove(B, K).getRoot();
+}
+
+//===----------------------------------------------------------------------===//
+// State pruning.
+//===----------------------------------------------------------------------===//
+  
+Store RegionStoreManager::RemoveDeadBindings(Store store, Stmt* Loc,
+                                             SymbolReaper& SymReaper,
+                           llvm::SmallVectorImpl<const MemRegion*>& RegionRoots)
+{
+  typedef std::pair<Store, const MemRegion *> RBDNode;
+
+  RegionBindings B = GetRegionBindings(store);
+
+  // The backmap from regions to subregions.
+  llvm::OwningPtr<RegionStoreSubRegionMap>
+    SubRegions(getRegionStoreSubRegionMap(store));
+  
+  // Do a pass over the regions in the store.  For VarRegions we check if
+  // the variable is still live and if so add it to the list of live roots.
+  // For other regions we populate our region backmap.
+  llvm::SmallVector<const MemRegion*, 10> IntermediateRoots;
+  
+  // Scan the direct bindings for "intermediate" roots.
+  for (RegionBindings::iterator I = B.begin(), E = B.end(); I != E; ++I) {
+    const MemRegion *R = I.getKey().getRegion();
+    IntermediateRoots.push_back(R);
+  }
+  
+  // Process the "intermediate" roots to find if they are referenced by
+  // real roots.
+  llvm::SmallVector<RBDNode, 10> WorkList;
+  llvm::SmallVector<RBDNode, 10> Postponed;
+
+  llvm::DenseSet<const MemRegion*> IntermediateVisited;
+  
+  while (!IntermediateRoots.empty()) {
+    const MemRegion* R = IntermediateRoots.back();
+    IntermediateRoots.pop_back();
+    
+    if (IntermediateVisited.count(R))
+      continue;
+    IntermediateVisited.insert(R);
+    
+    if (const VarRegion* VR = dyn_cast<VarRegion>(R)) {
+      if (SymReaper.isLive(Loc, VR))
+        WorkList.push_back(std::make_pair(store, VR));
+      continue;
+    }
+    
+    if (const SymbolicRegion* SR = dyn_cast<SymbolicRegion>(R)) {
+      llvm::SmallVectorImpl<RBDNode> &Q =      
+        SymReaper.isLive(SR->getSymbol()) ? WorkList : Postponed;
+      
+        Q.push_back(std::make_pair(store, SR));
+
+      continue;
+    }
+    
+      // Add the super region for R to the worklist if it is a subregion.
+    if (const SubRegion* superR =
+        dyn_cast<SubRegion>(cast<SubRegion>(R)->getSuperRegion()))
+      IntermediateRoots.push_back(superR);
+  }
+
+  // Enqueue the RegionRoots onto WorkList.
+  for (llvm::SmallVectorImpl<const MemRegion*>::iterator I=RegionRoots.begin(),
+       E=RegionRoots.end(); I!=E; ++I) {
+    WorkList.push_back(std::make_pair(store, *I));
+  }
+  RegionRoots.clear();
+  
+  llvm::DenseSet<RBDNode> Visited;
+  
+tryAgain:
+  while (!WorkList.empty()) {
+    RBDNode N = WorkList.back();
+    WorkList.pop_back();
+    
+    // Have we visited this node before?
+    if (Visited.count(N))
+      continue;
+    Visited.insert(N);
+
+    const MemRegion *R = N.second;
+    Store store_N = N.first;
+    
+    // Enqueue subregions.
+    RegionStoreSubRegionMap *M;
+      
+    if (store == store_N)
+      M = SubRegions.get();
+    else {
+      RegionStoreSubRegionMap *& SM = SC[store_N];
+      if (!SM)
+        SM = getRegionStoreSubRegionMap(store_N);
+      M = SM;
+    }
+
+    if (const RegionStoreSubRegionMap::Set *S = M->getSubRegions(R))
+      for (RegionStoreSubRegionMap::Set::iterator I = S->begin(), E = S->end();
+           I != E; ++I)
+        WorkList.push_back(std::make_pair(store_N, *I));
+
+    // Enqueue the super region.
+    if (const SubRegion *SR = dyn_cast<SubRegion>(R)) {
+      const MemRegion *superR = SR->getSuperRegion();
+      if (!isa<MemSpaceRegion>(superR)) {
+        // If 'R' is a field or an element, we want to keep the bindings
+        // for the other fields and elements around.  The reason is that
+        // pointer arithmetic can get us to the other fields or elements.
+        assert(isa<FieldRegion>(R) || isa<ElementRegion>(R) 
+               || isa<ObjCIvarRegion>(R));
+        WorkList.push_back(std::make_pair(store_N, superR));
+      }
+    }
+
+    // Mark the symbol for any live SymbolicRegion as "live".  This means we
+    // should continue to track that symbol.
+    if (const SymbolicRegion *SymR = dyn_cast<SymbolicRegion>(R))
+      SymReaper.markLive(SymR->getSymbol());
+    
+    // For BlockDataRegions, enqueue the VarRegions for variables marked
+    // with __block (passed-by-reference).
+    // via BlockDeclRefExprs.
+    if (const BlockDataRegion *BD = dyn_cast<BlockDataRegion>(R)) {
+      for (BlockDataRegion::referenced_vars_iterator
+            RI = BD->referenced_vars_begin(), RE = BD->referenced_vars_end();
+           RI != RE; ++RI) {
+        if ((*RI)->getDecl()->getAttr<BlocksAttr>())
+          WorkList.push_back(std::make_pair(store_N, *RI));
+      }
+      // No possible data bindings on a BlockDataRegion.  Continue to the
+      // next region in the worklist.
+      continue;
+    }
+
+    RegionBindings B_N = GetRegionBindings(store_N);
+    
+    // Get the data binding for R (if any).
+    Optional<SVal> V = getBinding(B_N, R);
+
+    if (V) {
+      // Check for lazy bindings.
+      if (const nonloc::LazyCompoundVal *LCV =
+            dyn_cast<nonloc::LazyCompoundVal>(V.getPointer())) {
+      
+        const LazyCompoundValData *D = LCV->getCVData();
+        WorkList.push_back(std::make_pair(D->getStore(), D->getRegion()));
+      }
+      else {
+        // Update the set of live symbols.
+        for (SVal::symbol_iterator SI=V->symbol_begin(), SE=V->symbol_end();
+             SI!=SE;++SI)
+          SymReaper.markLive(*SI);
+        
+        // If V is a region, then add it to the worklist.
+        if (const MemRegion *RX = V->getAsRegion())
+          WorkList.push_back(std::make_pair(store_N, RX));
+      }
+    }
+  }
+  
+  // See if any postponed SymbolicRegions are actually live now, after
+  // having done a scan.
+  for (llvm::SmallVectorImpl<RBDNode>::iterator I = Postponed.begin(),
+       E = Postponed.end() ; I != E ; ++I) {    
+    if (const SymbolicRegion *SR = cast_or_null<SymbolicRegion>(I->second)) {
+      if (SymReaper.isLive(SR->getSymbol())) {
+        WorkList.push_back(*I);
+        I->second = NULL;
+      }
+    }
+  }
+  
+  if (!WorkList.empty())
+    goto tryAgain;
+  
+  // We have now scanned the store, marking reachable regions and symbols
+  // as live.  We now remove all the regions that are dead from the store
+  // as well as update DSymbols with the set symbols that are now dead.
+  Store new_store = store;
+  for (RegionBindings::iterator I = B.begin(), E = B.end(); I != E; ++I) {
+    const MemRegion* R = I.getKey().getRegion();
+    // If this region live?  Is so, none of its symbols are dead.
+    if (Visited.count(std::make_pair(store, R)))
+      continue;
+
+    // Remove this dead region from the store.
+    new_store = Remove(new_store, I.getKey());
+
+    // Mark all non-live symbols that this region references as dead.
+    if (const SymbolicRegion* SymR = dyn_cast<SymbolicRegion>(R))
+      SymReaper.maybeDead(SymR->getSymbol());
+
+    SVal X = I.getData();
+    SVal::symbol_iterator SI = X.symbol_begin(), SE = X.symbol_end();
+    for (; SI != SE; ++SI)
+      SymReaper.maybeDead(*SI);
+  }
+
+  return new_store;
+}
+
+GRState const *RegionStoreManager::EnterStackFrame(GRState const *state,
+                                               StackFrameContext const *frame) {
+  FunctionDecl const *FD = cast<FunctionDecl>(frame->getDecl());
+  CallExpr const *CE = cast<CallExpr>(frame->getCallSite());
+
+  FunctionDecl::param_const_iterator PI = FD->param_begin();
+
+  CallExpr::const_arg_iterator AI = CE->arg_begin(), AE = CE->arg_end();
+
+  // Copy the arg expression value to the arg variables.
+  Store store = state->getStore();
+  for (; AI != AE; ++AI, ++PI) {
+    SVal ArgVal = state->getSVal(*AI);
+    store = Bind(store, ValMgr.makeLoc(MRMgr.getVarRegion(*PI, frame)), ArgVal);
+  }
+
+  return state->makeWithStore(store);
+}
+
+//===----------------------------------------------------------------------===//
+// Utility methods.
+//===----------------------------------------------------------------------===//
+
+void RegionStoreManager::print(Store store, llvm::raw_ostream& OS,
+                               const char* nl, const char *sep) {
+  RegionBindings B = GetRegionBindings(store);
+  OS << "Store (direct and default bindings):" << nl;
+
+  for (RegionBindings::iterator I = B.begin(), E = B.end(); I != E; ++I)
+    OS << ' ' << I.getKey() << " : " << I.getData() << nl;
+}