diff --git a/include/clang/Sema/CodeCompleteConsumer.h b/include/clang/Sema/CodeCompleteConsumer.h
index 2a8da32..a196bf9 100644
--- a/include/clang/Sema/CodeCompleteConsumer.h
+++ b/include/clang/Sema/CodeCompleteConsumer.h
@@ -121,7 +121,7 @@
 
 /// \brief Determine the type that this declaration will have if it is used
 /// as a type or in an expression.
-QualType getDeclUsageType(ASTContext &C, NamedDecl *ND);
+QualType getDeclUsageType(ASTContext &C, const NamedDecl *ND);
 
 /// \brief Determine the priority to be given to a macro code completion result
 /// with the given name.
@@ -530,7 +530,7 @@
 };
 
 class CodeCompletionTUInfo {
-  llvm::DenseMap<DeclContext *, StringRef> ParentNames;
+  llvm::DenseMap<const DeclContext *, StringRef> ParentNames;
   IntrusiveRefCntPtr<GlobalCodeCompletionAllocator> AllocatorRef;
 
 public:
@@ -546,7 +546,7 @@
     return *AllocatorRef;
   }
 
-  StringRef getParentName(DeclContext *DC);
+  StringRef getParentName(const DeclContext *DC);
 };
 
 } // end namespace clang
@@ -629,7 +629,7 @@
   void AddAnnotation(const char *A) { Annotations.push_back(A); }
 
   /// \brief Add the parent context information to this code completion.
-  void addParentContext(DeclContext *DC);
+  void addParentContext(const DeclContext *DC);
 
   void addBriefComment(StringRef Comment);
   
@@ -649,7 +649,7 @@
 
   /// \brief When Kind == RK_Declaration or RK_Pattern, the declaration we are
   /// referring to. In the latter case, the declaration might be NULL.
-  NamedDecl *Declaration;
+  const NamedDecl *Declaration;
 
   union {
     /// \brief When Kind == RK_Keyword, the string representing the keyword
@@ -704,7 +704,7 @@
   NestedNameSpecifier *Qualifier;
 
   /// \brief Build a result that refers to a declaration.
-  CodeCompletionResult(NamedDecl *Declaration,
+  CodeCompletionResult(const NamedDecl *Declaration,
                        NestedNameSpecifier *Qualifier = 0,
                        bool QualifierIsInformative = false,
                        bool Accessible = true)
@@ -764,7 +764,7 @@
   }  
   
   /// \brief Retrieve the declaration stored in this result.
-  NamedDecl *getDeclaration() const {
+  const NamedDecl *getDeclaration() const {
     assert(Kind == RK_Declaration && "Not a declaration result");
     return Declaration;
   }
@@ -793,7 +793,7 @@
                                            bool IncludeBriefComments);
 
   /// \brief Determine a base priority for the given declaration.
-  static unsigned getPriorityFromDecl(NamedDecl *ND);
+  static unsigned getPriorityFromDecl(const NamedDecl *ND);
 
 private:
   void computeCursorKindAndAvailability(bool Accessible = true);
diff --git a/include/clang/Sema/Sema.h b/include/clang/Sema/Sema.h
index 20d3db6..f649e1a 100644
--- a/include/clang/Sema/Sema.h
+++ b/include/clang/Sema/Sema.h
@@ -4013,7 +4013,7 @@
   bool ActOnCXXGlobalScopeSpecifier(Scope *S, SourceLocation CCLoc,
                                     CXXScopeSpec &SS);
 
-  bool isAcceptableNestedNameSpecifier(NamedDecl *SD);
+  bool isAcceptableNestedNameSpecifier(const NamedDecl *SD);
   NamedDecl *FindFirstQualifierInScope(Scope *S, NestedNameSpecifier *NNS);
 
   bool isNonTypeNestedNameSpecifier(Scope *S, CXXScopeSpec &SS,
@@ -5557,13 +5557,14 @@
                                   bool OnlyDeduced,
                                   unsigned Depth,
                                   llvm::SmallBitVector &Used);
-  void MarkDeducedTemplateParameters(FunctionTemplateDecl *FunctionTemplate,
-                                     llvm::SmallBitVector &Deduced) {
+  void MarkDeducedTemplateParameters(
+                                  const FunctionTemplateDecl *FunctionTemplate,
+                                  llvm::SmallBitVector &Deduced) {
     return MarkDeducedTemplateParameters(Context, FunctionTemplate, Deduced);
   }
   static void MarkDeducedTemplateParameters(ASTContext &Ctx,
-                                         FunctionTemplateDecl *FunctionTemplate,
-                                         llvm::SmallBitVector &Deduced);
+                                  const FunctionTemplateDecl *FunctionTemplate,
+                                  llvm::SmallBitVector &Deduced);
 
   //===--------------------------------------------------------------------===//
   // C++ Template Instantiation
diff --git a/lib/Frontend/ASTUnit.cpp b/lib/Frontend/ASTUnit.cpp
index 4feaad8..fcc8ea8 100644
--- a/lib/Frontend/ASTUnit.cpp
+++ b/lib/Frontend/ASTUnit.cpp
@@ -270,7 +270,7 @@
 
 /// \brief Determine the set of code-completion contexts in which this 
 /// declaration should be shown.
-static unsigned getDeclShowContexts(NamedDecl *ND,
+static unsigned getDeclShowContexts(const NamedDecl *ND,
                                     const LangOptions &LangOpts,
                                     bool &IsNestedNameSpecifier) {
   IsNestedNameSpecifier = false;
@@ -312,7 +312,7 @@
       // Part of the nested-name-specifier in C++0x.
       if (LangOpts.CPlusPlus11)
         IsNestedNameSpecifier = true;
-    } else if (RecordDecl *Record = dyn_cast<RecordDecl>(ND)) {
+    } else if (const RecordDecl *Record = dyn_cast<RecordDecl>(ND)) {
       if (Record->isUnion())
         Contexts |= (1LL << CodeCompletionContext::CCC_UnionTag);
       else
diff --git a/lib/Sema/CodeCompleteConsumer.cpp b/lib/Sema/CodeCompleteConsumer.cpp
index 85fc4ee..7877534 100644
--- a/lib/Sema/CodeCompleteConsumer.cpp
+++ b/lib/Sema/CodeCompleteConsumer.cpp
@@ -267,8 +267,8 @@
   return CopyString(String.toStringRef(Data));
 }
 
-StringRef CodeCompletionTUInfo::getParentName(DeclContext *DC) {
-  NamedDecl *ND = dyn_cast<NamedDecl>(DC);
+StringRef CodeCompletionTUInfo::getParentName(const DeclContext *DC) {
+  const NamedDecl *ND = dyn_cast<NamedDecl>(DC);
   if (!ND)
     return StringRef();
   
@@ -283,9 +283,9 @@
     return StringRef();
 
   // Find the interesting names.
-  SmallVector<DeclContext *, 2> Contexts;
+  SmallVector<const DeclContext *, 2> Contexts;
   while (DC && !DC->isFunctionOrMethod()) {
-    if (NamedDecl *ND = dyn_cast<NamedDecl>(DC)) {
+    if (const NamedDecl *ND = dyn_cast<NamedDecl>(DC)) {
       if (ND->getIdentifier())
         Contexts.push_back(DC);
     }
@@ -304,12 +304,12 @@
         OS << "::";
       }
       
-      DeclContext *CurDC = Contexts[I-1];
-      if (ObjCCategoryImplDecl *CatImpl = dyn_cast<ObjCCategoryImplDecl>(CurDC))
+      const DeclContext *CurDC = Contexts[I-1];
+      if (const ObjCCategoryImplDecl *CatImpl = dyn_cast<ObjCCategoryImplDecl>(CurDC))
         CurDC = CatImpl->getCategoryDecl();
       
-      if (ObjCCategoryDecl *Cat = dyn_cast<ObjCCategoryDecl>(CurDC)) {
-        ObjCInterfaceDecl *Interface = Cat->getClassInterface();
+      if (const ObjCCategoryDecl *Cat = dyn_cast<ObjCCategoryDecl>(CurDC)) {
+        const ObjCInterfaceDecl *Interface = Cat->getClassInterface();
         if (!Interface) {
           // Assign an empty StringRef but with non-null data to distinguish
           // between empty because we didn't process the DeclContext yet.
@@ -377,7 +377,7 @@
   Chunks.push_back(Chunk(CK, Text));
 }
 
-void CodeCompletionBuilder::addParentContext(DeclContext *DC) {
+void CodeCompletionBuilder::addParentContext(const DeclContext *DC) {
   if (DC->isTranslationUnit()) {
     return;
   }
@@ -385,7 +385,7 @@
   if (DC->isFunctionOrMethod())
     return;
   
-  NamedDecl *ND = dyn_cast<NamedDecl>(DC);
+  const NamedDecl *ND = dyn_cast<NamedDecl>(DC);
   if (!ND)
     return;
   
@@ -396,15 +396,16 @@
   BriefComment = Allocator.CopyString(Comment);
 }
 
-unsigned CodeCompletionResult::getPriorityFromDecl(NamedDecl *ND) {
+unsigned CodeCompletionResult::getPriorityFromDecl(const NamedDecl *ND) {
   if (!ND)
     return CCP_Unlikely;
   
   // Context-based decisions.
-  DeclContext *DC = ND->getDeclContext()->getRedeclContext();
+  const DeclContext *DC = ND->getDeclContext()->getRedeclContext();
   if (DC->isFunctionOrMethod() || isa<BlockDecl>(DC)) {
     // _cmd is relatively rare
-    if (ImplicitParamDecl *ImplicitParam = dyn_cast<ImplicitParamDecl>(ND))
+    if (const ImplicitParamDecl *ImplicitParam =
+            dyn_cast<ImplicitParamDecl>(ND))
       if (ImplicitParam->getIdentifier() &&
           ImplicitParam->getIdentifier()->isStr("_cmd"))
         return CCP_ObjC_cmd;
@@ -526,7 +527,7 @@
 }
 
 /// \brief Retrieve the effective availability of the given declaration.
-static AvailabilityResult getDeclAvailability(Decl *D) {
+static AvailabilityResult getDeclAvailability(const Decl *D) {
   AvailabilityResult AR = D->getAvailability();
   if (isa<EnumConstantDecl>(D))
     AR = std::max(AR, cast<Decl>(D->getDeclContext())->getAvailability());
@@ -559,7 +560,7 @@
       break;
     }
 
-    if (FunctionDecl *Function = dyn_cast<FunctionDecl>(Declaration))
+    if (const FunctionDecl *Function = dyn_cast<FunctionDecl>(Declaration))
       if (Function->isDeleted())
         Availability = CXAvailability_NotAvailable;
       
diff --git a/lib/Sema/SemaCXXScopeSpec.cpp b/lib/Sema/SemaCXXScopeSpec.cpp
index 979c05b..85efe2d 100644
--- a/lib/Sema/SemaCXXScopeSpec.cpp
+++ b/lib/Sema/SemaCXXScopeSpec.cpp
@@ -263,7 +263,7 @@
 
 /// \brief Determines whether the given declaration is an valid acceptable
 /// result for name lookup of a nested-name-specifier.
-bool Sema::isAcceptableNestedNameSpecifier(NamedDecl *SD) {
+bool Sema::isAcceptableNestedNameSpecifier(const NamedDecl *SD) {
   if (!SD)
     return false;
 
@@ -279,7 +279,7 @@
   QualType T = Context.getTypeDeclType(cast<TypeDecl>(SD));
   if (T->isDependentType())
     return true;
-  else if (TypedefNameDecl *TD = dyn_cast<TypedefNameDecl>(SD)) {
+  else if (const TypedefNameDecl *TD = dyn_cast<TypedefNameDecl>(SD)) {
     if (TD->getUnderlyingType()->isRecordType() ||
         (Context.getLangOpts().CPlusPlus11 &&
          TD->getUnderlyingType()->isEnumeralType()))
diff --git a/lib/Sema/SemaCodeComplete.cpp b/lib/Sema/SemaCodeComplete.cpp
index 5cbba23..ce580ce 100644
--- a/lib/Sema/SemaCodeComplete.cpp
+++ b/lib/Sema/SemaCodeComplete.cpp
@@ -45,7 +45,7 @@
     /// name-lookup routines to specify which declarations should be included in
     /// the result set (when it returns true) and which declarations should be
     /// filtered out (returns false).
-    typedef bool (ResultBuilder::*LookupFilter)(NamedDecl *) const;
+    typedef bool (ResultBuilder::*LookupFilter)(const NamedDecl *) const;
     
     typedef CodeCompletionResult Result;
     
@@ -56,9 +56,9 @@
     /// \brief A record of all of the declarations we have found and placed
     /// into the result set, used to ensure that no declaration ever gets into
     /// the result set twice.
-    llvm::SmallPtrSet<Decl*, 16> AllDeclsFound;
+    llvm::SmallPtrSet<const Decl*, 16> AllDeclsFound;
     
-    typedef std::pair<NamedDecl *, unsigned> DeclIndexPair;
+    typedef std::pair<const NamedDecl *, unsigned> DeclIndexPair;
 
     /// \brief An entry in the shadow map, which is optimized to store
     /// a single (declaration, index) mapping (the common case) but
@@ -68,7 +68,7 @@
 
       /// \brief Contains either the solitary NamedDecl * or a vector
       /// of (declaration, index) pairs.
-      llvm::PointerUnion<NamedDecl *, DeclIndexPairVector*> DeclOrVector;
+      llvm::PointerUnion<const NamedDecl *, DeclIndexPairVector*> DeclOrVector;
 
       /// \brief When the entry contains a single declaration, this is
       /// the index associated with that entry.
@@ -77,7 +77,7 @@
     public:
       ShadowMapEntry() : DeclOrVector(), SingleDeclIndex(0) { }
 
-      void Add(NamedDecl *ND, unsigned Index) {
+      void Add(const NamedDecl *ND, unsigned Index) {
         if (DeclOrVector.isNull()) {
           // 0 - > 1 elements: just set the single element information.
           DeclOrVector = ND;
@@ -85,7 +85,8 @@
           return;
         }
 
-        if (NamedDecl *PrevND = DeclOrVector.dyn_cast<NamedDecl *>()) {
+        if (const NamedDecl *PrevND =
+                DeclOrVector.dyn_cast<const NamedDecl *>()) {
           // 1 -> 2 elements: create the vector of results and push in the
           // existing declaration.
           DeclIndexPairVector *Vec = new DeclIndexPairVector;
@@ -265,7 +266,8 @@
     ///
     /// \param AsNestedNameSpecifier will be set true if this declaration is
     /// only interesting when it is a nested-name-specifier.
-    bool isInterestingDecl(NamedDecl *ND, bool &AsNestedNameSpecifier) const;
+    bool isInterestingDecl(const NamedDecl *ND,
+                           bool &AsNestedNameSpecifier) const;
     
     /// \brief Check whether the result is hidden by the Hiding declaration.
     ///
@@ -274,7 +276,7 @@
     /// modified to describe how the result can be found (e.g., via extra
     /// qualification).
     bool CheckHiddenResult(Result &R, DeclContext *CurContext,
-                           NamedDecl *Hiding);
+                           const NamedDecl *Hiding);
     
     /// \brief Add a new result to this result set (if it isn't already in one
     /// of the shadow maps), or replace an existing result (for, e.g., a 
@@ -317,29 +319,29 @@
     /// results of name lookup. All of the predicates have the same type, so that
     /// 
     //@{
-    bool IsOrdinaryName(NamedDecl *ND) const;
-    bool IsOrdinaryNonTypeName(NamedDecl *ND) const;
-    bool IsIntegralConstantValue(NamedDecl *ND) const;
-    bool IsOrdinaryNonValueName(NamedDecl *ND) const;
-    bool IsNestedNameSpecifier(NamedDecl *ND) const;
-    bool IsEnum(NamedDecl *ND) const;
-    bool IsClassOrStruct(NamedDecl *ND) const;
-    bool IsUnion(NamedDecl *ND) const;
-    bool IsNamespace(NamedDecl *ND) const;
-    bool IsNamespaceOrAlias(NamedDecl *ND) const;
-    bool IsType(NamedDecl *ND) const;
-    bool IsMember(NamedDecl *ND) const;
-    bool IsObjCIvar(NamedDecl *ND) const;
-    bool IsObjCMessageReceiver(NamedDecl *ND) const;
-    bool IsObjCMessageReceiverOrLambdaCapture(NamedDecl *ND) const;
-    bool IsObjCCollection(NamedDecl *ND) const;
-    bool IsImpossibleToSatisfy(NamedDecl *ND) const;
+    bool IsOrdinaryName(const NamedDecl *ND) const;
+    bool IsOrdinaryNonTypeName(const NamedDecl *ND) const;
+    bool IsIntegralConstantValue(const NamedDecl *ND) const;
+    bool IsOrdinaryNonValueName(const NamedDecl *ND) const;
+    bool IsNestedNameSpecifier(const NamedDecl *ND) const;
+    bool IsEnum(const NamedDecl *ND) const;
+    bool IsClassOrStruct(const NamedDecl *ND) const;
+    bool IsUnion(const NamedDecl *ND) const;
+    bool IsNamespace(const NamedDecl *ND) const;
+    bool IsNamespaceOrAlias(const NamedDecl *ND) const;
+    bool IsType(const NamedDecl *ND) const;
+    bool IsMember(const NamedDecl *ND) const;
+    bool IsObjCIvar(const NamedDecl *ND) const;
+    bool IsObjCMessageReceiver(const NamedDecl *ND) const;
+    bool IsObjCMessageReceiverOrLambdaCapture(const NamedDecl *ND) const;
+    bool IsObjCCollection(const NamedDecl *ND) const;
+    bool IsImpossibleToSatisfy(const NamedDecl *ND) const;
     //@}    
   };  
 }
 
 class ResultBuilder::ShadowMapEntry::iterator {
-  llvm::PointerUnion<NamedDecl*, const DeclIndexPair*> DeclOrIterator;
+  llvm::PointerUnion<const NamedDecl *, const DeclIndexPair *> DeclOrIterator;
   unsigned SingleDeclIndex;
 
 public:
@@ -361,14 +363,14 @@
         
   iterator() : DeclOrIterator((NamedDecl *)0), SingleDeclIndex(0) { }
 
-  iterator(NamedDecl *SingleDecl, unsigned Index)
+  iterator(const NamedDecl *SingleDecl, unsigned Index)
     : DeclOrIterator(SingleDecl), SingleDeclIndex(Index) { }
 
   iterator(const DeclIndexPair *Iterator)
     : DeclOrIterator(Iterator), SingleDeclIndex(0) { }
 
   iterator &operator++() {
-    if (DeclOrIterator.is<NamedDecl *>()) {
+    if (DeclOrIterator.is<const NamedDecl *>()) {
       DeclOrIterator = (NamedDecl *)0;
       SingleDeclIndex = 0;
       return *this;
@@ -387,7 +389,7 @@
   }*/
 
   reference operator*() const {
-    if (NamedDecl *ND = DeclOrIterator.dyn_cast<NamedDecl *>())
+    if (const NamedDecl *ND = DeclOrIterator.dyn_cast<const NamedDecl *>())
       return reference(ND, SingleDeclIndex);
 
     return *DeclOrIterator.get<const DeclIndexPair*>();
@@ -413,7 +415,7 @@
   if (DeclOrVector.isNull())
     return iterator();
 
-  if (NamedDecl *ND = DeclOrVector.dyn_cast<NamedDecl *>())
+  if (const NamedDecl *ND = DeclOrVector.dyn_cast<const NamedDecl *>())
     return iterator(ND, SingleDeclIndex);
 
   return iterator(DeclOrVector.get<DeclIndexPairVector *>()->begin());
@@ -421,7 +423,7 @@
 
 ResultBuilder::ShadowMapEntry::iterator 
 ResultBuilder::ShadowMapEntry::end() const {
-  if (DeclOrVector.is<NamedDecl *>() || DeclOrVector.isNull())
+  if (DeclOrVector.is<const NamedDecl *>() || DeclOrVector.isNull())
     return iterator();
 
   return iterator(DeclOrVector.get<DeclIndexPairVector *>()->end());
@@ -442,11 +444,11 @@
 /// NULL if no qualification is needed.
 static NestedNameSpecifier *
 getRequiredQualification(ASTContext &Context,
-                         DeclContext *CurContext,
-                         DeclContext *TargetContext) {
-  SmallVector<DeclContext *, 4> TargetParents;
+                         const DeclContext *CurContext,
+                         const DeclContext *TargetContext) {
+  SmallVector<const DeclContext *, 4> TargetParents;
   
-  for (DeclContext *CommonAncestor = TargetContext;
+  for (const DeclContext *CommonAncestor = TargetContext;
        CommonAncestor && !CommonAncestor->Encloses(CurContext);
        CommonAncestor = CommonAncestor->getLookupParent()) {
     if (CommonAncestor->isTransparentContext() ||
@@ -458,16 +460,16 @@
   
   NestedNameSpecifier *Result = 0;
   while (!TargetParents.empty()) {
-    DeclContext *Parent = TargetParents.back();
+    const DeclContext *Parent = TargetParents.back();
     TargetParents.pop_back();
     
-    if (NamespaceDecl *Namespace = dyn_cast<NamespaceDecl>(Parent)) {
+    if (const NamespaceDecl *Namespace = dyn_cast<NamespaceDecl>(Parent)) {
       if (!Namespace->getIdentifier())
         continue;
 
       Result = NestedNameSpecifier::Create(Context, Result, Namespace);
     }
-    else if (TagDecl *TD = dyn_cast<TagDecl>(Parent))
+    else if (const TagDecl *TD = dyn_cast<TagDecl>(Parent))
       Result = NestedNameSpecifier::Create(Context, Result,
                                            false,
                                      Context.getTypeDeclType(TD).getTypePtr());
@@ -475,7 +477,7 @@
   return Result;
 }
 
-bool ResultBuilder::isInterestingDecl(NamedDecl *ND, 
+bool ResultBuilder::isInterestingDecl(const NamedDecl *ND,
                                       bool &AsNestedNameSpecifier) const {
   AsNestedNameSpecifier = false;
 
@@ -547,14 +549,15 @@
 }
 
 bool ResultBuilder::CheckHiddenResult(Result &R, DeclContext *CurContext,
-                                      NamedDecl *Hiding) {
+                                      const NamedDecl *Hiding) {
   // In C, there is no way to refer to a hidden name.
   // FIXME: This isn't true; we can find a tag name hidden by an ordinary
   // name if we introduce the tag type.
   if (!SemaRef.getLangOpts().CPlusPlus)
     return true;
   
-  DeclContext *HiddenCtx = R.Declaration->getDeclContext()->getRedeclContext();
+  const DeclContext *HiddenCtx =
+      R.Declaration->getDeclContext()->getRedeclContext();
   
   // There is no way to qualify a name declared in a function or method.
   if (HiddenCtx->isFunctionOrMethod())
@@ -645,26 +648,27 @@
 
 /// \brief Get the type that a given expression will have if this declaration
 /// is used as an expression in its "typical" code-completion form.
-QualType clang::getDeclUsageType(ASTContext &C, NamedDecl *ND) {
+QualType clang::getDeclUsageType(ASTContext &C, const NamedDecl *ND) {
   ND = cast<NamedDecl>(ND->getUnderlyingDecl());
   
-  if (TypeDecl *Type = dyn_cast<TypeDecl>(ND))
+  if (const TypeDecl *Type = dyn_cast<TypeDecl>(ND))
     return C.getTypeDeclType(Type);
-  if (ObjCInterfaceDecl *Iface = dyn_cast<ObjCInterfaceDecl>(ND))
+  if (const ObjCInterfaceDecl *Iface = dyn_cast<ObjCInterfaceDecl>(ND))
     return C.getObjCInterfaceType(Iface);
   
   QualType T;
-  if (FunctionDecl *Function = dyn_cast<FunctionDecl>(ND))
+  if (const FunctionDecl *Function = dyn_cast<FunctionDecl>(ND))
     T = Function->getCallResultType();
-  else if (ObjCMethodDecl *Method = dyn_cast<ObjCMethodDecl>(ND))
+  else if (const ObjCMethodDecl *Method = dyn_cast<ObjCMethodDecl>(ND))
     T = Method->getSendResultType();
-  else if (FunctionTemplateDecl *FunTmpl = dyn_cast<FunctionTemplateDecl>(ND))
+  else if (const FunctionTemplateDecl *FunTmpl =
+               dyn_cast<FunctionTemplateDecl>(ND))
     T = FunTmpl->getTemplatedDecl()->getCallResultType();
-  else if (EnumConstantDecl *Enumerator = dyn_cast<EnumConstantDecl>(ND))
+  else if (const EnumConstantDecl *Enumerator = dyn_cast<EnumConstantDecl>(ND))
     T = C.getTypeDeclType(cast<EnumDecl>(Enumerator->getDeclContext()));
-  else if (ObjCPropertyDecl *Property = dyn_cast<ObjCPropertyDecl>(ND))
+  else if (const ObjCPropertyDecl *Property = dyn_cast<ObjCPropertyDecl>(ND))
     T = Property->getType();
-  else if (ValueDecl *Value = dyn_cast<ValueDecl>(ND))
+  else if (const ValueDecl *Value = dyn_cast<ValueDecl>(ND))
     T = Value->getType();
   else
     return QualType();
@@ -707,7 +711,7 @@
   // If this is an Objective-C method declaration whose selector matches our
   // preferred selector, give it a priority boost.
   if (!PreferredSelector.isNull())
-    if (ObjCMethodDecl *Method = dyn_cast<ObjCMethodDecl>(R.Declaration))
+    if (const ObjCMethodDecl *Method = dyn_cast<ObjCMethodDecl>(R.Declaration))
       if (PreferredSelector == Method->getSelector())
         R.Priority += CCD_SelectorMatch;
   
@@ -735,9 +739,9 @@
     return;
   
   ASTContext &Context = SemaRef.Context;
-  NamedDecl *D = R.Declaration;
-  CXXRecordDecl *Record = 0;
-  if (ClassTemplateDecl *ClassTemplate = dyn_cast<ClassTemplateDecl>(D))
+  const NamedDecl *D = R.Declaration;
+  const CXXRecordDecl *Record = 0;
+  if (const ClassTemplateDecl *ClassTemplate = dyn_cast<ClassTemplateDecl>(D))
     Record = ClassTemplate->getTemplatedDecl();
   else if ((Record = dyn_cast<CXXRecordDecl>(D))) {
     // Skip specializations and partial specializations.
@@ -757,9 +761,10 @@
   DeclarationName ConstructorName
     = Context.DeclarationNames.getCXXConstructorName(
                                            Context.getCanonicalType(RecordTy));
-  DeclContext::lookup_result Ctors = Record->lookup(ConstructorName);
-  for (DeclContext::lookup_iterator I = Ctors.begin(), E = Ctors.end(); I != E;
-       ++I) {
+  DeclContext::lookup_const_result Ctors = Record->lookup(ConstructorName);
+  for (DeclContext::lookup_const_iterator I = Ctors.begin(),
+                                          E = Ctors.end();
+       I != E; ++I) {
     R.Declaration = *I;
     R.CursorKind = getCursorKindForDecl(R.Declaration);
     Results.push_back(R);
@@ -776,12 +781,13 @@
   }
 
   // Look through using declarations.
-  if (UsingShadowDecl *Using = dyn_cast<UsingShadowDecl>(R.Declaration)) {
+  if (const UsingShadowDecl *Using =
+          dyn_cast<UsingShadowDecl>(R.Declaration)) {
     MaybeAddResult(Result(Using->getTargetDecl(), R.Qualifier), CurContext);
     return;
   }
   
-  Decl *CanonDecl = R.Declaration->getCanonicalDecl();
+  const Decl *CanonDecl = R.Declaration->getCanonicalDecl();
   unsigned IDNS = CanonDecl->getIdentifierNamespace();
 
   bool AsNestedNameSpecifier = false;
@@ -801,7 +807,7 @@
   }
 
   for (; I != IEnd; ++I) {
-    NamedDecl *ND = I->first;
+    const NamedDecl *ND = I->first;
     unsigned Index = I->second;
     if (ND->getCanonicalDecl() == CanonDecl) {
       // This is a redeclaration. Always pick the newer declaration.
@@ -860,10 +866,10 @@
   // If this result is supposed to have an informative qualifier, add one.
   if (R.QualifierIsInformative && !R.Qualifier &&
       !R.StartsNestedNameSpecifier) {
-    DeclContext *Ctx = R.Declaration->getDeclContext();
-    if (NamespaceDecl *Namespace = dyn_cast<NamespaceDecl>(Ctx))
+    const DeclContext *Ctx = R.Declaration->getDeclContext();
+    if (const NamespaceDecl *Namespace = dyn_cast<NamespaceDecl>(Ctx))
       R.Qualifier = NestedNameSpecifier::Create(SemaRef.Context, 0, Namespace);
-    else if (TagDecl *Tag = dyn_cast<TagDecl>(Ctx))
+    else if (const TagDecl *Tag = dyn_cast<TagDecl>(Ctx))
       R.Qualifier = NestedNameSpecifier::Create(SemaRef.Context, 0, false, 
                              SemaRef.Context.getTypeDeclType(Tag).getTypePtr());
     else
@@ -888,7 +894,7 @@
   }
 
   // Look through using declarations.
-  if (UsingShadowDecl *Using = dyn_cast<UsingShadowDecl>(R.Declaration)) {
+  if (const UsingShadowDecl *Using = dyn_cast<UsingShadowDecl>(R.Declaration)) {
     AddResult(Result(Using->getTargetDecl(), R.Qualifier), CurContext, Hiding);
     return;
   }
@@ -922,10 +928,10 @@
   // If this result is supposed to have an informative qualifier, add one.
   if (R.QualifierIsInformative && !R.Qualifier &&
       !R.StartsNestedNameSpecifier) {
-    DeclContext *Ctx = R.Declaration->getDeclContext();
-    if (NamespaceDecl *Namespace = dyn_cast<NamespaceDecl>(Ctx))
+    const DeclContext *Ctx = R.Declaration->getDeclContext();
+    if (const NamespaceDecl *Namespace = dyn_cast<NamespaceDecl>(Ctx))
       R.Qualifier = NestedNameSpecifier::Create(SemaRef.Context, 0, Namespace);
-    else if (TagDecl *Tag = dyn_cast<TagDecl>(Ctx))
+    else if (const TagDecl *Tag = dyn_cast<TagDecl>(Ctx))
       R.Qualifier = NestedNameSpecifier::Create(SemaRef.Context, 0, false, 
                             SemaRef.Context.getTypeDeclType(Tag).getTypePtr());
     else
@@ -939,7 +945,7 @@
   AdjustResultPriorityForDecl(R);
   
   if (HasObjectTypeQualifiers)
-    if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(R.Declaration))
+    if (const CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(R.Declaration))
       if (Method->isInstance()) {
         Qualifiers MethodQuals
                         = Qualifiers::fromCVRMask(Method->getTypeQualifiers());
@@ -983,7 +989,7 @@
 
 /// \brief Determines whether this given declaration will be found by
 /// ordinary name lookup.
-bool ResultBuilder::IsOrdinaryName(NamedDecl *ND) const {
+bool ResultBuilder::IsOrdinaryName(const NamedDecl *ND) const {
   ND = cast<NamedDecl>(ND->getUnderlyingDecl());
 
   unsigned IDNS = Decl::IDNS_Ordinary;
@@ -999,7 +1005,7 @@
 
 /// \brief Determines whether this given declaration will be found by
 /// ordinary name lookup but is not a type name.
-bool ResultBuilder::IsOrdinaryNonTypeName(NamedDecl *ND) const {
+bool ResultBuilder::IsOrdinaryNonTypeName(const NamedDecl *ND) const {
   ND = cast<NamedDecl>(ND->getUnderlyingDecl());
   if (isa<TypeDecl>(ND) || isa<ObjCInterfaceDecl>(ND))
     return false;
@@ -1015,11 +1021,11 @@
   return ND->getIdentifierNamespace() & IDNS;
 }
 
-bool ResultBuilder::IsIntegralConstantValue(NamedDecl *ND) const {
+bool ResultBuilder::IsIntegralConstantValue(const NamedDecl *ND) const {
   if (!IsOrdinaryNonTypeName(ND))
     return 0;
   
-  if (ValueDecl *VD = dyn_cast<ValueDecl>(ND->getUnderlyingDecl()))
+  if (const ValueDecl *VD = dyn_cast<ValueDecl>(ND->getUnderlyingDecl()))
     if (VD->getType()->isIntegralOrEnumerationType())
       return true;
         
@@ -1028,7 +1034,7 @@
 
 /// \brief Determines whether this given declaration will be found by
 /// ordinary name lookup.
-bool ResultBuilder::IsOrdinaryNonValueName(NamedDecl *ND) const {
+bool ResultBuilder::IsOrdinaryNonValueName(const NamedDecl *ND) const {
   ND = cast<NamedDecl>(ND->getUnderlyingDecl());
 
   unsigned IDNS = Decl::IDNS_Ordinary;
@@ -1042,27 +1048,27 @@
 
 /// \brief Determines whether the given declaration is suitable as the 
 /// start of a C++ nested-name-specifier, e.g., a class or namespace.
-bool ResultBuilder::IsNestedNameSpecifier(NamedDecl *ND) const {
+bool ResultBuilder::IsNestedNameSpecifier(const NamedDecl *ND) const {
   // Allow us to find class templates, too.
-  if (ClassTemplateDecl *ClassTemplate = dyn_cast<ClassTemplateDecl>(ND))
+  if (const ClassTemplateDecl *ClassTemplate = dyn_cast<ClassTemplateDecl>(ND))
     ND = ClassTemplate->getTemplatedDecl();
   
   return SemaRef.isAcceptableNestedNameSpecifier(ND);
 }
 
 /// \brief Determines whether the given declaration is an enumeration.
-bool ResultBuilder::IsEnum(NamedDecl *ND) const {
+bool ResultBuilder::IsEnum(const NamedDecl *ND) const {
   return isa<EnumDecl>(ND);
 }
 
 /// \brief Determines whether the given declaration is a class or struct.
-bool ResultBuilder::IsClassOrStruct(NamedDecl *ND) const {
+bool ResultBuilder::IsClassOrStruct(const NamedDecl *ND) const {
   // Allow us to find class templates, too.
-  if (ClassTemplateDecl *ClassTemplate = dyn_cast<ClassTemplateDecl>(ND))
+  if (const ClassTemplateDecl *ClassTemplate = dyn_cast<ClassTemplateDecl>(ND))
     ND = ClassTemplate->getTemplatedDecl();
 
   // For purposes of this check, interfaces match too.
-  if (RecordDecl *RD = dyn_cast<RecordDecl>(ND))
+  if (const RecordDecl *RD = dyn_cast<RecordDecl>(ND))
     return RD->getTagKind() == TTK_Class ||
     RD->getTagKind() == TTK_Struct ||
     RD->getTagKind() == TTK_Interface;
@@ -1071,31 +1077,31 @@
 }
 
 /// \brief Determines whether the given declaration is a union.
-bool ResultBuilder::IsUnion(NamedDecl *ND) const {
+bool ResultBuilder::IsUnion(const NamedDecl *ND) const {
   // Allow us to find class templates, too.
-  if (ClassTemplateDecl *ClassTemplate = dyn_cast<ClassTemplateDecl>(ND))
+  if (const ClassTemplateDecl *ClassTemplate = dyn_cast<ClassTemplateDecl>(ND))
     ND = ClassTemplate->getTemplatedDecl();
   
-  if (RecordDecl *RD = dyn_cast<RecordDecl>(ND))
+  if (const RecordDecl *RD = dyn_cast<RecordDecl>(ND))
     return RD->getTagKind() == TTK_Union;
   
   return false;
 }
 
 /// \brief Determines whether the given declaration is a namespace.
-bool ResultBuilder::IsNamespace(NamedDecl *ND) const {
+bool ResultBuilder::IsNamespace(const NamedDecl *ND) const {
   return isa<NamespaceDecl>(ND);
 }
 
 /// \brief Determines whether the given declaration is a namespace or 
 /// namespace alias.
-bool ResultBuilder::IsNamespaceOrAlias(NamedDecl *ND) const {
+bool ResultBuilder::IsNamespaceOrAlias(const NamedDecl *ND) const {
   return isa<NamespaceDecl>(ND) || isa<NamespaceAliasDecl>(ND);
 }
 
 /// \brief Determines whether the given declaration is a type.
-bool ResultBuilder::IsType(NamedDecl *ND) const {
-  if (UsingShadowDecl *Using = dyn_cast<UsingShadowDecl>(ND))
+bool ResultBuilder::IsType(const NamedDecl *ND) const {
+  if (const UsingShadowDecl *Using = dyn_cast<UsingShadowDecl>(ND))
     ND = Using->getTargetDecl();
   
   return isa<TypeDecl>(ND) || isa<ObjCInterfaceDecl>(ND);
@@ -1104,8 +1110,8 @@
 /// \brief Determines which members of a class should be visible via
 /// "." or "->".  Only value declarations, nested name specifiers, and
 /// using declarations thereof should show up.
-bool ResultBuilder::IsMember(NamedDecl *ND) const {
-  if (UsingShadowDecl *Using = dyn_cast<UsingShadowDecl>(ND))
+bool ResultBuilder::IsMember(const NamedDecl *ND) const {
+  if (const UsingShadowDecl *Using = dyn_cast<UsingShadowDecl>(ND))
     ND = Using->getTargetDecl();
 
   return isa<ValueDecl>(ND) || isa<FunctionTemplateDecl>(ND) ||
@@ -1145,7 +1151,7 @@
   return T->isDependentType() || T->isRecordType();
 }
 
-bool ResultBuilder::IsObjCMessageReceiver(NamedDecl *ND) const {
+bool ResultBuilder::IsObjCMessageReceiver(const NamedDecl *ND) const {
   QualType T = getDeclUsageType(SemaRef.Context, ND);
   if (T.isNull())
     return false;
@@ -1154,18 +1160,18 @@
   return isObjCReceiverType(SemaRef.Context, T);
 }
 
-bool ResultBuilder::IsObjCMessageReceiverOrLambdaCapture(NamedDecl *ND) const {
+bool ResultBuilder::IsObjCMessageReceiverOrLambdaCapture(const NamedDecl *ND) const {
   if (IsObjCMessageReceiver(ND))
     return true;
   
-  VarDecl *Var = dyn_cast<VarDecl>(ND);
+  const VarDecl *Var = dyn_cast<VarDecl>(ND);
   if (!Var)
     return false;
   
   return Var->hasLocalStorage() && !Var->hasAttr<BlocksAttr>();
 }
 
-bool ResultBuilder::IsObjCCollection(NamedDecl *ND) const {
+bool ResultBuilder::IsObjCCollection(const NamedDecl *ND) const {
   if ((SemaRef.getLangOpts().CPlusPlus && !IsOrdinaryName(ND)) ||
       (!SemaRef.getLangOpts().CPlusPlus && !IsOrdinaryNonTypeName(ND)))
     return false;
@@ -1180,13 +1186,13 @@
          (SemaRef.getLangOpts().CPlusPlus && T->isRecordType());
 }
 
-bool ResultBuilder::IsImpossibleToSatisfy(NamedDecl *ND) const {
+bool ResultBuilder::IsImpossibleToSatisfy(const NamedDecl *ND) const {
   return false;
 }
 
 /// \brief Determines whether the given declaration is an Objective-C
 /// instance variable.
-bool ResultBuilder::IsObjCIvar(NamedDecl *ND) const {
+bool ResultBuilder::IsObjCIvar(const NamedDecl *ND) const {
   return isa<ObjCIvarDecl>(ND);
 }
 
@@ -1998,7 +2004,7 @@
 /// type chunk.
 static void AddResultTypeChunk(ASTContext &Context,
                                const PrintingPolicy &Policy,
-                               NamedDecl *ND,
+                               const NamedDecl *ND,
                                CodeCompletionBuilder &Result) {
   if (!ND)
     return;
@@ -2010,19 +2016,20 @@
 
   // Determine the type of the declaration (if it has a type).
   QualType T;  
-  if (FunctionDecl *Function = dyn_cast<FunctionDecl>(ND))
+  if (const FunctionDecl *Function = dyn_cast<FunctionDecl>(ND))
     T = Function->getResultType();
-  else if (ObjCMethodDecl *Method = dyn_cast<ObjCMethodDecl>(ND))
+  else if (const ObjCMethodDecl *Method = dyn_cast<ObjCMethodDecl>(ND))
     T = Method->getResultType();
-  else if (FunctionTemplateDecl *FunTmpl = dyn_cast<FunctionTemplateDecl>(ND))
+  else if (const FunctionTemplateDecl *FunTmpl =
+               dyn_cast<FunctionTemplateDecl>(ND))
     T = FunTmpl->getTemplatedDecl()->getResultType();
-  else if (EnumConstantDecl *Enumerator = dyn_cast<EnumConstantDecl>(ND))
+  else if (const EnumConstantDecl *Enumerator = dyn_cast<EnumConstantDecl>(ND))
     T = Context.getTypeDeclType(cast<TypeDecl>(Enumerator->getDeclContext()));
   else if (isa<UnresolvedUsingValueDecl>(ND)) {
     /* Do nothing: ignore unresolved using declarations*/
-  } else if (ValueDecl *Value = dyn_cast<ValueDecl>(ND)) {
+  } else if (const ValueDecl *Value = dyn_cast<ValueDecl>(ND)) {
     T = Value->getType();
-  } else if (ObjCPropertyDecl *Property = dyn_cast<ObjCPropertyDecl>(ND))
+  } else if (const ObjCPropertyDecl *Property = dyn_cast<ObjCPropertyDecl>(ND))
     T = Property->getType();
   
   if (T.isNull() || Context.hasSameType(T, Context.DependentTy))
@@ -2032,7 +2039,8 @@
                                                     Result.getAllocator()));
 }
 
-static void MaybeAddSentinel(ASTContext &Context, NamedDecl *FunctionOrMethod,
+static void MaybeAddSentinel(ASTContext &Context,
+                             const NamedDecl *FunctionOrMethod,
                              CodeCompletionBuilder &Result) {
   if (SentinelAttr *Sentinel = FunctionOrMethod->getAttr<SentinelAttr>())
     if (Sentinel->getSentinel() == 0) {
@@ -2065,7 +2073,7 @@
 
 static std::string FormatFunctionParameter(ASTContext &Context,
                                            const PrintingPolicy &Policy,
-                                           ParmVarDecl *Param,
+                                           const ParmVarDecl *Param,
                                            bool SuppressName = false,
                                            bool SuppressBlock = false) {
   bool ObjCMethodParam = isa<ObjCMethodDecl>(Param->getDeclContext());
@@ -2196,14 +2204,14 @@
 /// \brief Add function parameter chunks to the given code completion string.
 static void AddFunctionParameterChunks(ASTContext &Context,
                                        const PrintingPolicy &Policy,
-                                       FunctionDecl *Function,
+                                       const FunctionDecl *Function,
                                        CodeCompletionBuilder &Result,
                                        unsigned Start = 0,
                                        bool InOptional = false) {
   bool FirstParameter = true;
   
   for (unsigned P = Start, N = Function->getNumParams(); P != N; ++P) {
-    ParmVarDecl *Param = Function->getParamDecl(P);
+    const ParmVarDecl *Param = Function->getParamDecl(P);
     
     if (Param->hasDefaultArg() && !InOptional) {
       // When we see an optional default argument, put that argument and
@@ -2249,7 +2257,7 @@
 /// \brief Add template parameter chunks to the given code completion string.
 static void AddTemplateParameterChunks(ASTContext &Context,
                                        const PrintingPolicy &Policy,
-                                       TemplateDecl *Template,
+                                       const TemplateDecl *Template,
                                        CodeCompletionBuilder &Result,
                                        unsigned MaxParameters = 0,
                                        unsigned Start = 0,
@@ -2347,7 +2355,7 @@
 
 static void 
 AddFunctionTypeQualsToCompletionString(CodeCompletionBuilder &Result,
-                                       FunctionDecl *Function) {
+                                       const FunctionDecl *Function) {
   const FunctionProtoType *Proto
     = Function->getType()->getAs<FunctionProtoType>();
   if (!Proto || !Proto->getTypeQuals())
@@ -2384,7 +2392,8 @@
 
 /// \brief Add the name of the given declaration 
 static void AddTypedNameChunk(ASTContext &Context, const PrintingPolicy &Policy,
-                              NamedDecl *ND, CodeCompletionBuilder &Result) {
+                              const NamedDecl *ND,
+                              CodeCompletionBuilder &Result) {
   DeclarationName Name = ND->getDeclName();
   if (!Name)
     return;
@@ -2541,7 +2550,7 @@
   }
   
   assert(Kind == RK_Declaration && "Missed a result kind?");
-  NamedDecl *ND = Declaration;
+  const NamedDecl *ND = Declaration;
   Result.addParentContext(ND->getDeclContext());
 
   if (IncludeBriefComments) {
@@ -2566,7 +2575,7 @@
   
   AddResultTypeChunk(Ctx, Policy, ND, Result);
   
-  if (FunctionDecl *Function = dyn_cast<FunctionDecl>(ND)) {
+  if (const FunctionDecl *Function = dyn_cast<FunctionDecl>(ND)) {
     AddQualifierToCompletionString(Result, Qualifier, QualifierIsInformative, 
                                    Ctx, Policy);
     AddTypedNameChunk(Ctx, Policy, ND, Result);
@@ -2577,7 +2586,7 @@
     return Result.TakeString();
   }
   
-  if (FunctionTemplateDecl *FunTmpl = dyn_cast<FunctionTemplateDecl>(ND)) {
+  if (const FunctionTemplateDecl *FunTmpl = dyn_cast<FunctionTemplateDecl>(ND)) {
     AddQualifierToCompletionString(Result, Qualifier, QualifierIsInformative, 
                                    Ctx, Policy);
     FunctionDecl *Function = FunTmpl->getTemplatedDecl();
@@ -2631,7 +2640,7 @@
     return Result.TakeString();
   }
   
-  if (TemplateDecl *Template = dyn_cast<TemplateDecl>(ND)) {
+  if (const TemplateDecl *Template = dyn_cast<TemplateDecl>(ND)) {
     AddQualifierToCompletionString(Result, Qualifier, QualifierIsInformative, 
                                    Ctx, Policy);
     Result.AddTypedTextChunk(
@@ -2642,7 +2651,7 @@
     return Result.TakeString();
   }
   
-  if (ObjCMethodDecl *Method = dyn_cast<ObjCMethodDecl>(ND)) {
+  if (const ObjCMethodDecl *Method = dyn_cast<ObjCMethodDecl>(ND)) {
     Selector Sel = Method->getSelector();
     if (Sel.isUnarySelector()) {
       Result.AddTypedTextChunk(Result.getAllocator().CopyString(
@@ -2663,8 +2672,8 @@
         Result.AddTypedTextChunk("");
     }
     unsigned Idx = 0;
-    for (ObjCMethodDecl::param_iterator P = Method->param_begin(),
-                                     PEnd = Method->param_end();
+    for (ObjCMethodDecl::param_const_iterator P = Method->param_begin(),
+                                           PEnd = Method->param_end();
          P != PEnd; (void)++P, ++Idx) {
       if (Idx > 0) {
         std::string Keyword;
@@ -5284,7 +5293,7 @@
     if (R.Kind == Result::RK_Declaration && 
         isa<ObjCMethodDecl>(R.Declaration)) {
       if (R.Priority <= BestPriority) {
-        ObjCMethodDecl *Method = cast<ObjCMethodDecl>(R.Declaration);
+        const ObjCMethodDecl *Method = cast<ObjCMethodDecl>(R.Declaration);
         if (NumSelIdents <= Method->param_size()) {
           QualType MyPreferredType = Method->param_begin()[NumSelIdents - 1]
                                        ->getType();
diff --git a/lib/Sema/SemaTemplateDeduction.cpp b/lib/Sema/SemaTemplateDeduction.cpp
index 00a48e9..a8de3a8 100644
--- a/lib/Sema/SemaTemplateDeduction.cpp
+++ b/lib/Sema/SemaTemplateDeduction.cpp
@@ -4604,7 +4604,7 @@
 /// call to the given function template.
 void
 Sema::MarkDeducedTemplateParameters(ASTContext &Ctx,
-                                    FunctionTemplateDecl *FunctionTemplate,
+                                    const FunctionTemplateDecl *FunctionTemplate,
                                     llvm::SmallBitVector &Deduced) {
   TemplateParameterList *TemplateParams
     = FunctionTemplate->getTemplateParameters();