[analyzer] Move the files in lib/StaticAnalyzer to lib/StaticAnalyzer/Core.

Eventually there will also be a lib/StaticAnalyzer/Frontend that will handle initialization and checker registration.
Yet another library to avoid cyclic dependencies between Core and Checkers.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@125124 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 1917 insertions, 0 deletions

diff --git a/lib/StaticAnalyzer/Core/RegionStore.cpp b/lib/StaticAnalyzer/Core/RegionStore.cpp
new file mode 100644
index 0000000000..d5af1c2747
--- /dev/null
+++ b/lib/StaticAnalyzer/Core/RegionStore.cpp
@@ -0,0 +1,1917 @@
+//== 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/AST/CharUnits.h"
+#include "clang/AST/DeclCXX.h"
+#include "clang/AST/ExprCXX.h"
+#include "clang/Analysis/Analyses/LiveVariables.h"
+#include "clang/Analysis/AnalysisContext.h"
+#include "clang/Basic/TargetInfo.h"
+#include "clang/StaticAnalyzer/PathSensitive/GRState.h"
+#include "clang/StaticAnalyzer/PathSensitive/GRStateTrait.h"
+#include "clang/StaticAnalyzer/PathSensitive/MemRegion.h"
+#include "llvm/ADT/ImmutableList.h"
+#include "llvm/ADT/ImmutableMap.h"
+#include "llvm/ADT/Optional.h"
+#include "llvm/Support/raw_ostream.h"
+
+using namespace clang;
+using namespace ento;
+using llvm::Optional;
+
+//===----------------------------------------------------------------------===//
+// 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) {}
+public:
+
+  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;
+  }
+
+  bool isValid() const {
+    return getRegion() != NULL;
+  }
+};
+} // end anonymous namespace
+
+BindingKey BindingKey::Make(const MemRegion *R, Kind k) {
+  if (const ElementRegion *ER = dyn_cast<ElementRegion>(R)) {
+    const RegionRawOffset &O = ER->getAsArrayOffset();
+
+    // FIXME: There are some ElementRegions for which we cannot compute
+    // raw offsets yet, including regions with symbolic offsets. These will be
+    // ignored by the store.
+    return BindingKey(O.getRegion(), O.getOffset().getQuantity(), k);
+  }
+
+  return BindingKey(R, 0, k);
+}
+
+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;
+public:
+  RegionStoreFeatures(minimal_features_tag) :
+    SupportsFields(false) {}
+
+  RegionStoreFeatures(maximal_features_tag) :
+    SupportsFields(true) {}
+
+  void enableFields(bool t) { SupportsFields = t; }
+
+  bool supportsFields() const { return SupportsFields; }
+};
+}
+
+//===----------------------------------------------------------------------===//
+// 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;
+  }
+};
+
+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);
+}
+
+class RegionStoreManager : public StoreManager {
+  const RegionStoreFeatures Features;
+  RegionBindings::Factory RBFactory;
+
+public:
+  RegionStoreManager(GRStateManager& mgr, const RegionStoreFeatures &f)
+    : StoreManager(mgr),
+      Features(f),
+      RBFactory(mgr.getAllocator()) {}
+
+  SubRegionMap *getSubRegionMap(Store store) {
+    return getRegionStoreSubRegionMap(store);
+  }
+
+  RegionStoreSubRegionMap *getRegionStoreSubRegionMap(Store store);
+
+  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 ExprEngine when evaluating
+  ///  casts from arrays to pointers.
+  SVal ArrayToPointer(Loc Array);
+
+  /// For DerivedToBase casts, create a CXXBaseObjectRegion and return it.
+  virtual SVal evalDerivedToBase(SVal derived, QualType basePtrType);
+
+  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 InvalidateRegions(Store store,
+                          const MemRegion * const *Begin,
+                          const MemRegion * const *End,
+                          const Expr *E, unsigned Count,
+                          InvalidatedSymbols *IS,
+                          bool invalidateGlobals,
+                          InvalidatedRegions *Regions);
+
+public:   // Made public for helper classes.
+
+  void RemoveSubRegionBindings(RegionBindings &B, const MemRegion *R,
+                               RegionStoreSubRegionMap &M);
+
+  RegionBindings addBinding(RegionBindings B, BindingKey K, SVal V);
+
+  RegionBindings addBinding(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 removeBinding(RegionBindings B, BindingKey K);
+  RegionBindings removeBinding(RegionBindings B, const MemRegion *R,
+                        BindingKey::Kind k);
+
+  RegionBindings removeBinding(RegionBindings B, const MemRegion *R) {
+    return removeBinding(removeBinding(B, R, BindingKey::Direct), R,
+                        BindingKey::Default);
+  }
+
+public: // Part of public interface to class.
+
+  Store Bind(Store store, Loc LV, SVal V);
+
+  // BindDefault is only used to initialize a region with a default value.
+  Store BindDefault(Store store, const MemRegion *R, SVal V) {
+    RegionBindings B = GetRegionBindings(store);
+    assert(!lookup(B, R, BindingKey::Default));
+    assert(!lookup(B, R, BindingKey::Direct));
+    return addBinding(B, R, BindingKey::Default, V).getRoot();
+  }
+
+  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, SVal DefaultVal);
+
+  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);
+
+  /// Used to lazily generate derived symbols for bindings that are defined
+  ///  implicitly by default bindings in a super region.
+  Optional<SVal> RetrieveDerivedDefaultValue(RegionBindings B,
+                                             const MemRegion *superR,
+                                             const TypedRegion *R, QualType Ty);
+
+  /// 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);
+
+  //===------------------------------------------------------------------===//
+  // State pruning.
+  //===------------------------------------------------------------------===//
+
+  /// removeDeadBindings - Scans the RegionStore of 'state' for dead values.
+  ///  It returns a new Store with these values removed.
+  Store removeDeadBindings(Store store, const StackFrameContext *LCtx,
+                           SymbolReaper& SymReaper,
+                          llvm::SmallVectorImpl<const MemRegion*>& RegionRoots);
+
+  Store enterStackFrame(const GRState *state, const StackFrameContext *frame);
+
+  //===------------------------------------------------------------------===//
+  // Region "extents".
+  //===------------------------------------------------------------------===//
+
+  // FIXME: This method will soon be eliminated; see the note in Store.h.
+  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) {
+    RegionBindings B = GetRegionBindings(store);
+    for (RegionBindings::iterator I=B.begin(), E=B.end(); I!=E; ++I) {
+      const BindingKey &K = I.getKey();
+      if (!K.isDirect())
+        continue;
+      if (const SubRegion *R = dyn_cast<SubRegion>(I.getKey().getRegion())) {
+        // FIXME: Possibly incorporate the offset?
+        if (!f.HandleBinding(*this, store, R, I.getData()))
+          return;
+      }
+    }
+  }
+};
+
+} // end anonymous namespace
+
+//===----------------------------------------------------------------------===//
+// RegionStore creation.
+//===----------------------------------------------------------------------===//
+
+StoreManager *ento::CreateRegionStoreManager(GRStateManager& StMgr) {
+  RegionStoreFeatures F = maximal_features_tag();
+  return new RegionStoreManager(StMgr, F);
+}
+
+StoreManager *ento::CreateFieldsOnlyRegionStoreManager(GRStateManager &StMgr) {
+  RegionStoreFeatures F = minimal_features_tag();
+  F.enableFields(true);
+  return new RegionStoreManager(StMgr, F);
+}
+
+
+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;
+}
+
+//===----------------------------------------------------------------------===//
+// Region Cluster analysis.
+//===----------------------------------------------------------------------===//
+
+namespace {
+template <typename DERIVED>
+class ClusterAnalysis  {
+protected:
+  typedef BumpVector<BindingKey> RegionCluster;
+  typedef llvm::DenseMap<const MemRegion *, RegionCluster *> ClusterMap;
+  llvm::DenseMap<const RegionCluster*, unsigned> Visited;
+  typedef llvm::SmallVector<std::pair<const MemRegion *, RegionCluster*>, 10>
+    WorkList;
+
+  BumpVectorContext BVC;
+  ClusterMap ClusterM;
+  WorkList WL;
+
+  RegionStoreManager &RM;
+  ASTContext &Ctx;
+  SValBuilder &svalBuilder;
+
+  RegionBindings B;
+  
+  const bool includeGlobals;
+
+public:
+  ClusterAnalysis(RegionStoreManager &rm, GRStateManager &StateMgr,
+                  RegionBindings b, const bool includeGlobals)
+    : RM(rm), Ctx(StateMgr.getContext()),
+      svalBuilder(StateMgr.getSValBuilder()),
+      B(b), includeGlobals(includeGlobals) {}
+
+  RegionBindings getRegionBindings() const { return B; }
+
+  RegionCluster &AddToCluster(BindingKey K) {
+    const MemRegion *R = K.getRegion();
+    const MemRegion *baseR = R->getBaseRegion();
+    RegionCluster &C = getCluster(baseR);
+    C.push_back(K, BVC);
+    static_cast<DERIVED*>(this)->VisitAddedToCluster(baseR, C);
+    return C;
+  }
+
+  bool isVisited(const MemRegion *R) {
+    return (bool) Visited[&getCluster(R->getBaseRegion())];
+  }
+
+  RegionCluster& getCluster(const MemRegion *R) {
+    RegionCluster *&CRef = ClusterM[R];
+    if (!CRef) {
+      void *Mem = BVC.getAllocator().template Allocate<RegionCluster>();
+      CRef = new (Mem) RegionCluster(BVC, 10);
+    }
+    return *CRef;
+  }
+
+  void GenerateClusters() {
+      // Scan the entire set of bindings and make the region clusters.
+    for (RegionBindings::iterator RI = B.begin(), RE = B.end(); RI != RE; ++RI){
+      RegionCluster &C = 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());
+      }
+      if (includeGlobals) {
+        const MemRegion *R = RI.getKey().getRegion();
+        if (isa<NonStaticGlobalSpaceRegion>(R->getMemorySpace()))
+          AddToWorkList(R, C);
+      }
+    }
+  }
+
+  bool AddToWorkList(const MemRegion *R, RegionCluster &C) {
+    if (unsigned &visited = Visited[&C])
+      return false;
+    else
+      visited = 1;
+
+    WL.push_back(std::make_pair(R, &C));
+    return true;
+  }
+
+  bool AddToWorkList(BindingKey K) {
+    return AddToWorkList(K.getRegion());
+  }
+
+  bool AddToWorkList(const MemRegion *R) {
+    const MemRegion *baseR = R->getBaseRegion();
+    return AddToWorkList(baseR, getCluster(baseR));
+  }
+
+  void RunWorkList() {
+    while (!WL.empty()) {
+      const MemRegion *baseR;
+      RegionCluster *C;
+      llvm::tie(baseR, C) = WL.back();
+      WL.pop_back();
+
+        // First visit the cluster.
+      static_cast<DERIVED*>(this)->VisitCluster(baseR, C->begin(), C->end());
+
+        // Next, visit the base region.
+      static_cast<DERIVED*>(this)->VisitBaseRegion(baseR);
+    }
+  }
+
+public:
+  void VisitAddedToCluster(const MemRegion *baseR, RegionCluster &C) {}
+  void VisitCluster(const MemRegion *baseR, BindingKey *I, BindingKey *E) {}
+  void VisitBaseRegion(const MemRegion *baseR) {}
+};
+}
+
+//===----------------------------------------------------------------------===//
+// 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 = removeBinding(B, R);
+}
+
+namespace {
+class InvalidateRegionsWorker : public ClusterAnalysis<InvalidateRegionsWorker>
+{
+  const Expr *Ex;
+  unsigned Count;
+  StoreManager::InvalidatedSymbols *IS;
+  StoreManager::InvalidatedRegions *Regions;
+public:
+  InvalidateRegionsWorker(RegionStoreManager &rm,
+                          GRStateManager &stateMgr,
+                          RegionBindings b,
+                          const Expr *ex, unsigned count,
+                          StoreManager::InvalidatedSymbols *is,
+                          StoreManager::InvalidatedRegions *r,
+                          bool includeGlobals)
+    : ClusterAnalysis<InvalidateRegionsWorker>(rm, stateMgr, b, includeGlobals),
+      Ex(ex), Count(count), IS(is), Regions(r) {}
+
+  void VisitCluster(const MemRegion *baseR, BindingKey *I, BindingKey *E);
+  void VisitBaseRegion(const MemRegion *baseR);
+
+private:
+  void VisitBinding(SVal V);
+};
+}
+
+void InvalidateRegionsWorker::VisitBinding(SVal V) {
+  // A symbol?  Mark it touched by the invalidation.
+  if (IS)
+    if (SymbolRef Sym = V.getAsSymbol())
+      IS->insert(Sym);
+
+  if (const MemRegion *R = V.getAsRegion()) {
+    AddToWorkList(R);
+    return;
+  }
+
+  // Is it a LazyCompoundVal?  All references get invalidated as well.
+  if (const nonloc::LazyCompoundVal *LCS =
+        dyn_cast<nonloc::LazyCompoundVal>(&V)) {
+
+    const MemRegion *LazyR = LCS->getRegion();
+    RegionBindings B = RegionStoreManager::GetRegionBindings(LCS->getStore());
+
+    for (RegionBindings::iterator RI = B.begin(), RE = B.end(); RI != RE; ++RI){
+      const SubRegion *baseR = dyn_cast<SubRegion>(RI.getKey().getRegion());
+      if (baseR && baseR->isSubRegionOf(LazyR))
+        VisitBinding(RI.getData());
+    }
+
+    return;
+  }
+}
+
+void InvalidateRegionsWorker::VisitCluster(const MemRegion *baseR,
+                                           BindingKey *I, BindingKey *E) {
+  for ( ; I != E; ++I) {
+    // Get the old binding.  Is it a region?  If so, add it to the worklist.
+    const BindingKey &K = *I;
+    if (const SVal *V = RM.lookup(B, K))
+      VisitBinding(*V);
+
+    B = RM.removeBinding(B, K);
+  }
+}
+
+void InvalidateRegionsWorker::VisitBaseRegion(const MemRegion *baseR) {
+  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);
+    }
+    return;
+  }
+
+  // Otherwise, we have a normal data region. Record that we touched the region.
+  if (Regions)
+    Regions->push_back(baseR);
+
+  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 =
+      svalBuilder.getConjuredSymbolVal(baseR, Ex, Ctx.IntTy, Count);
+    B = RM.addBinding(B, baseR, BindingKey::Default, V);
+    return;
+  }
+
+  if (!baseR->isBoundable())
+    return;
+
+  const TypedRegion *TR = cast<TypedRegion>(baseR);
+  QualType T = TR->getValueType();
+
+    // Invalidate the binding.
+  if (T->isStructureType()) {
+    // Invalidate the region by setting its default value to
+    // conjured symbol. The type of the symbol is irrelavant.
+    DefinedOrUnknownSVal V = svalBuilder.getConjuredSymbolVal(baseR, Ex, Ctx.IntTy,
+                                                         Count);
+    B = RM.addBinding(B, baseR, BindingKey::Default, V);
+    return;
+  }
+
+  if (const ArrayType *AT = Ctx.getAsArrayType(T)) {
+      // Set the default value of the array to conjured symbol.
+    DefinedOrUnknownSVal V =
+    svalBuilder.getConjuredSymbolVal(baseR, Ex, AT->getElementType(), Count);
+    B = RM.addBinding(B, baseR, BindingKey::Default, V);
+    return;
+  }
+  
+  if (includeGlobals && 
+      isa<NonStaticGlobalSpaceRegion>(baseR->getMemorySpace())) {
+    // If the region is a global and we are invalidating all globals,
+    // just erase the entry.  This causes all globals to be lazily
+    // symbolicated from the same base symbol.
+    B = RM.removeBinding(B, baseR);
+    return;
+  }
+  
+
+  DefinedOrUnknownSVal V = svalBuilder.getConjuredSymbolVal(baseR, Ex, T, Count);
+  assert(SymbolManager::canSymbolicate(T) || V.isUnknown());
+  B = RM.addBinding(B, baseR, BindingKey::Direct, V);
+}
+
+Store RegionStoreManager::InvalidateRegions(Store store,
+                                            const MemRegion * const *I,
+                                            const MemRegion * const *E,
+                                            const Expr *Ex, unsigned Count,
+                                            InvalidatedSymbols *IS,
+                                            bool invalidateGlobals,
+                                            InvalidatedRegions *Regions) {
+  InvalidateRegionsWorker W(*this, StateMgr,
+                            RegionStoreManager::GetRegionBindings(store),
+                            Ex, Count, IS, Regions, invalidateGlobals);
+
+  // Scan the bindings and generate the clusters.
+  W.GenerateClusters();
+
+  // Add I .. E to the worklist.
+  for ( ; I != E; ++I)
+    W.AddToWorkList(*I);
+
+  W.RunWorkList();
+
+  // Return the new bindings.
+  RegionBindings B = W.getRegionBindings();
+
+  if (invalidateGlobals) {
+    // Bind the non-static globals memory space to a new symbol that we will
+    // use to derive the bindings for all non-static globals.
+    const GlobalsSpaceRegion *GS = MRMgr.getGlobalsRegion();
+    SVal V =
+      svalBuilder.getConjuredSymbolVal(/* SymbolTag = */ (void*) GS, Ex,
+                                  /* symbol type, doesn't matter */ Ctx.IntTy,
+                                  Count);
+    B = addBinding(B, BindingKey::Make(GS, BindingKey::Default), V);
+
+    // Even if there are no bindings in the global scope, we still need to
+    // record that we touched it.
+    if (Regions)
+      Regions->push_back(GS);
+  }
+
+  return B.getRoot();
+}
+
+//===----------------------------------------------------------------------===//
+// Extents for regions.
+//===----------------------------------------------------------------------===//
+
+DefinedOrUnknownSVal RegionStoreManager::getSizeInElements(const GRState *state,
+                                                           const MemRegion *R,
+                                                           QualType EleTy) {
+  SVal Size = cast<SubRegion>(R)->getExtent(svalBuilder);
+  const llvm::APSInt *SizeInt = svalBuilder.getKnownValue(state, Size);
+  if (!SizeInt)
+    return UnknownVal();
+
+  CharUnits RegionSize = CharUnits::fromQuantity(SizeInt->getSExtValue());
+
+  if (Ctx.getAsVariableArrayType(EleTy)) {
+    // FIXME: We need to track extra state to properly record the size
+    // of VLAs.  Returning UnknownVal here, however, is a stop-gap so that
+    // we don't have a divide-by-zero below.
+    return UnknownVal();
+  }
+
+  CharUnits EleSize = Ctx.getTypeSizeInChars(EleTy);
+
+  // If a variable is reinterpreted as a type that doesn't fit into a larger
+  // type evenly, round it down.
+  // This is a signed value, since it's used in arithmetic with signed indices.
+  return svalBuilder.makeIntVal(RegionSize / EleSize, false);
+}
+
+//===----------------------------------------------------------------------===//
+// 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 ExprEngine 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().getDesugaredType(Ctx);
+  const ArrayType *AT = cast<ArrayType>(T);
+  T = AT->getElementType();
+
+  NonLoc ZeroIdx = svalBuilder.makeZeroArrayIndex();
+  return loc::MemRegionVal(MRMgr.getElementRegion(T, ZeroIdx, ArrayR, Ctx));
+}
+
+SVal RegionStoreManager::evalDerivedToBase(SVal derived, QualType baseType) {
+  const CXXRecordDecl *baseDecl;
+  if (baseType->isPointerType())
+    baseDecl = baseType->getCXXRecordDeclForPointerType();
+  else
+    baseDecl = baseType->getAsCXXRecordDecl();
+
+  assert(baseDecl && "not a CXXRecordDecl?");
+
+  loc::MemRegionVal *derivedRegVal = dyn_cast<loc::MemRegionVal>(&derived);
+  if (!derivedRegVal)
+    return derived;
+
+  const MemRegion *baseReg = 
+    MRMgr.getCXXBaseObjectRegion(baseDecl, derivedRegVal->getRegion()); 
+
+  return loc::MemRegionVal(baseReg);
+}
+//===----------------------------------------------------------------------===//
+// 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();
+
+  // Special case for zero RHS.
+  if (R.isZeroConstant()) {
+    switch (Op) {
+    default:
+      // Handle it normally.
+      break;
+    case BO_Add:
+    case BO_Sub:
+      // FIXME: does this need to be casted to match resultTy?
+      return L;
+    }
+  }
+
+  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(Ctx);
+      QualType EleTy;
+
+      if (const PointerType *PT = T->getAs<PointerType>())
+        EleTy = PT->getPointeeType();
+      else
+        EleTy = T->getAs<ObjCObjectPointerType>()->getPointeeType();
+
+      const NonLoc &ZeroIdx = svalBuilder.makeZeroArrayIndex();
+      ER = MRMgr.getElementRegion(EleTy, ZeroIdx, SR, Ctx);
+      break;
+    }
+    case MemRegion::AllocaRegionKind: {
+      const AllocaRegion *AR = cast<AllocaRegion>(MR);
+      QualType EleTy = Ctx.CharTy; // Create an ElementRegion of bytes.
+      NonLoc ZeroIdx = svalBuilder.makeZeroArrayIndex();
+      ER = MRMgr.getElementRegion(EleTy, ZeroIdx, AR, Ctx);
+      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::CXXTempObjectRegionKind:
+    case MemRegion::CXXBaseObjectRegionKind:
+      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::NonStaticGlobalSpaceRegionKind:
+    case MemRegion::StaticGlobalSpaceRegionKind:
+    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 SValBuilder here.
+      SVal NewIdx =
+        Base->evalBinOp(svalBuilder, Op,
+                cast<nonloc::ConcreteInt>(svalBuilder.convertToArrayIndex(*Offset)));
+
+      if (!isa<NonLoc>(NewIdx))
+        return UnknownVal();
+
+      const MemRegion* NewER =
+        MRMgr.getElementRegion(ER->getElementType(), cast<NonLoc>(NewIdx),
+                               ER->getSuperRegion(), Ctx);
+      return svalBuilder.makeLoc(NewER);
+    }
+    if (0 == Base->getValue()) {
+      const MemRegion* NewER =
+        MRMgr.getElementRegion(ER->getElementType(), R,
+                               ER->getSuperRegion(), Ctx);
+      return svalBuilder.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()->isUnionType())
+        return UnknownVal();
+
+  if (const SVal *V = lookup(B, R, BindingKey::Default))
+    return *V;
+
+  return Optional<SVal>();
+}
+
+SVal RegionStoreManager::Retrieve(Store store, Loc L, QualType T) {
+  assert(!isa<UnknownVal>(L) && "location unknown");
+  assert(!isa<UndefinedVal>(L) && "location undefined");
+
+  // For access to concrete addresses, return UnknownVal.  Checks
+  // for null dereferences (and similar errors) are done by checkers, not
+  // the Store.
+  // FIXME: We can consider lazily symbolicating such memory, but we really
+  // should defer this when we can reason easily about symbolicating arrays
+  // of bytes.
+  if (isa<loc::ConcreteInt>(L)) {
+    return UnknownVal();
+  }
+  if (!isa<loc::MemRegionVal>(L)) {
+    return UnknownVal();
+  }
+
+  con