In ASTReader, replace the never-NULL ASTContext pointer with an

ASTContext reference. Remove all of the extra checking and logic that
was used to cope with a NULL ASTContext. No effective functionality
change.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@139413 91177308-0d34-0410-b5e6-96231b3b80d8

4 files changed, 298 insertions, 332 deletions

diff --git a/include/clang/Serialization/ASTReader.h b/include/clang/Serialization/ASTReader.h
index e7019f311d..4d38a666f7 100644
--- a/include/clang/Serialization/ASTReader.h
+++ b/include/clang/Serialization/ASTReader.h
@@ -233,7 +233,7 @@ private:
   Preprocessor *PP;
 
   /// \brief The AST context into which we'll read the AST files.
-  ASTContext *Context;
+  ASTContext &Context;
       
   /// \brief The AST consumer.
   ASTConsumer *Consumer;
@@ -752,8 +752,8 @@ public:
   /// \brief Set the Preprocessor to use.
   void setPreprocessor(Preprocessor &pp);
 
-  /// \brief Sets and initializes the given Context.
-  void InitializeContext(ASTContext &Context);
+  /// \brief Initializes the ASTContext
+  void InitializeContext();
 
   /// \brief Add in-memory (virtual file) buffer.
   void addInMemoryBuffer(StringRef &FileName, llvm::MemoryBuffer *Buffer) {
@@ -1267,7 +1267,7 @@ public:
   }
   
   /// \brief Retrieve the AST context that this AST reader supplements.
-  ASTContext *getContext() { return Context; }
+  ASTContext &getContext() { return Context; }
 
   // \brief Contains declarations that were loaded before we have
   // access to a Sema object.
diff --git a/lib/Serialization/ASTReader.cpp b/lib/Serialization/ASTReader.cpp
index 55dd213286..f0b06259a7 100644
--- a/lib/Serialization/ASTReader.cpp
+++ b/lib/Serialization/ASTReader.cpp
@@ -498,7 +498,7 @@ ASTSelectorLookupTrait::ReadKeyDataLength(const unsigned char*& d) {
 ASTSelectorLookupTrait::internal_key_type 
 ASTSelectorLookupTrait::ReadKey(const unsigned char* d, unsigned) {
   using namespace clang::io;
-  SelectorTable &SelTable = Reader.getContext()->Selectors;
+  SelectorTable &SelTable = Reader.getContext().Selectors;
   unsigned N = ReadUnalignedLE16(d);
   IdentifierInfo *FirstII
     = Reader.getLocalIdentifier(F, ReadUnalignedLE32(d));
@@ -632,7 +632,6 @@ IdentifierInfo *ASTIdentifierLookupTrait::ReadData(const internal_key_type& k,
 
   // Read all of the declarations visible at global scope with this
   // name.
-  if (Reader.getContext() == 0) return II;
   if (DataLen > 0) {
     SmallVector<uint32_t, 4> DeclIDs;
     for (; DataLen > 0; DataLen -= 4)
@@ -706,7 +705,7 @@ ASTDeclContextNameLookupTrait::GetInternalKey(
 ASTDeclContextNameLookupTrait::external_key_type 
 ASTDeclContextNameLookupTrait::GetExternalKey(
                                           const internal_key_type& Key) const {
-  ASTContext *Context = Reader.getContext();
+  ASTContext &Context = Reader.getContext();
   switch (Key.Kind) {
   case DeclarationName::Identifier:
     return DeclarationName((IdentifierInfo*)Key.Data);
@@ -717,23 +716,23 @@ ASTDeclContextNameLookupTrait::GetExternalKey(
     return DeclarationName(Selector(Key.Data));
 
   case DeclarationName::CXXConstructorName:
-    return Context->DeclarationNames.getCXXConstructorName(
-             Context->getCanonicalType(Reader.getLocalType(F, Key.Data)));
+    return Context.DeclarationNames.getCXXConstructorName(
+             Context.getCanonicalType(Reader.getLocalType(F, Key.Data)));
 
   case DeclarationName::CXXDestructorName:
-    return Context->DeclarationNames.getCXXDestructorName(
-             Context->getCanonicalType(Reader.getLocalType(F, Key.Data)));
+    return Context.DeclarationNames.getCXXDestructorName(
+             Context.getCanonicalType(Reader.getLocalType(F, Key.Data)));
 
   case DeclarationName::CXXConversionFunctionName:
-    return Context->DeclarationNames.getCXXConversionFunctionName(
-             Context->getCanonicalType(Reader.getLocalType(F, Key.Data)));
+    return Context.DeclarationNames.getCXXConversionFunctionName(
+             Context.getCanonicalType(Reader.getLocalType(F, Key.Data)));
 
   case DeclarationName::CXXOperatorName:
-    return Context->DeclarationNames.getCXXOperatorName(
+    return Context.DeclarationNames.getCXXOperatorName(
                                        (OverloadedOperatorKind)Key.Data);
 
   case DeclarationName::CXXLiteralOperatorName:
-    return Context->DeclarationNames.getCXXLiteralOperatorName(
+    return Context.DeclarationNames.getCXXLiteralOperatorName(
                                                    (IdentifierInfo*)Key.Data);
 
   case DeclarationName::CXXUsingDirective:
@@ -1934,14 +1933,12 @@ ASTReader::ReadASTBlock(Module &F) {
     }
         
     case TU_UPDATE_LEXICAL: {
-      DeclContext *TU = Context ? Context->getTranslationUnitDecl() : 0;
+      DeclContext *TU = Context.getTranslationUnitDecl();
       DeclContextInfo &Info = F.DeclContextInfos[TU];
       Info.LexicalDecls = reinterpret_cast<const KindDeclIDPair *>(BlobStart);
       Info.NumLexicalDecls 
         = static_cast<unsigned int>(BlobLen / sizeof(KindDeclIDPair));
-      if (TU)
-        TU->setHasExternalLexicalStorage(true);
-
+      TU->setHasExternalLexicalStorage(true);
       break;
     }
 
@@ -1952,8 +1949,8 @@ ASTReader::ReadASTBlock(Module &F) {
                         (const unsigned char *)BlobStart + Record[Idx++],
                         (const unsigned char *)BlobStart,
                         ASTDeclContextNameLookupTrait(*this, F));
-      if (ID == PREDEF_DECL_TRANSLATION_UNIT_ID && Context) { // Is it the TU?
-        DeclContext *TU = Context->getTranslationUnitDecl();
+      if (ID == PREDEF_DECL_TRANSLATION_UNIT_ID) { // Is it the TU?
+        DeclContext *TU = Context.getTranslationUnitDecl();
         F.DeclContextInfos[TU].NameLookupTableData = Table;
         TU->setHasExternalVisibleStorage(true);
       } else
@@ -2635,8 +2632,7 @@ ASTReader::ASTReadResult ASTReader::ReadAST(const std::string &FileName,
     }
   }
 
-  if (Context)
-    InitializeContext(*Context);
+  InitializeContext();
 
   if (DeserializationListener)
     DeserializationListener->ReaderInitialized(this);
@@ -2797,59 +2793,38 @@ void ASTReader::setPreprocessor(Preprocessor &pp) {
   PP->getHeaderSearchInfo().SetExternalSource(this);
 }
 
-void ASTReader::InitializeContext(ASTContext &Ctx) {
-  Context = &Ctx;
-  assert(Context && "Passed null context!");
-  
+void ASTReader::InitializeContext() {
   assert(PP && "Forgot to set Preprocessor ?");
   PP->getIdentifierTable().setExternalIdentifierLookup(this);
   PP->setExternalSource(this);
   
-  // If we have any update blocks for the TU waiting, we have to add
-  // them before we deserialize anything.
-  TranslationUnitDecl *TU = Ctx.getTranslationUnitDecl();
-  for (ModuleIterator M = ModuleMgr.begin(), MEnd = ModuleMgr.end(); 
-       M != MEnd; ++M) {
-    Module::DeclContextInfosMap::iterator DCU
-      = (*M)->DeclContextInfos.find(0);
-    if (DCU != (*M)->DeclContextInfos.end()) {
-      // Insertion could invalidate map, so grab value first.
-      DeclContextInfo Info = DCU->second;
-      (*M)->DeclContextInfos.erase(DCU);
-      (*M)->DeclContextInfos[TU] = Info;
-      
-      if (Info.NumLexicalDecls)
-        TU->setHasExternalLexicalStorage();
-      if (Info.NameLookupTableData)
-        TU->setHasExternalVisibleStorage();
-    }
-  }
-  
   // If there's a listener, notify them that we "read" the translation unit.
   if (DeserializationListener)
-    DeserializationListener->DeclRead(PREDEF_DECL_TRANSLATION_UNIT_ID, TU);
+    DeserializationListener->DeclRead(PREDEF_DECL_TRANSLATION_UNIT_ID, 
+                                      Context.getTranslationUnitDecl());
 
   // Make sure we load the declaration update records for the translation unit,
   // if there are any.
-  loadDeclUpdateRecords(PREDEF_DECL_TRANSLATION_UNIT_ID, TU);
+  loadDeclUpdateRecords(PREDEF_DECL_TRANSLATION_UNIT_ID, 
+                        Context.getTranslationUnitDecl());
   
   // FIXME: Find a better way to deal with collisions between these
   // built-in types. Right now, we just ignore the problem.
   
   // Load the special types.
-  if (Context->getBuiltinVaListType().isNull()) {
-    Context->setBuiltinVaListType(
+  if (Context.getBuiltinVaListType().isNull()) {
+    Context.setBuiltinVaListType(
       GetType(SpecialTypes[SPECIAL_TYPE_BUILTIN_VA_LIST]));
   }
   
   if (unsigned Proto = SpecialTypes[SPECIAL_TYPE_OBJC_PROTOCOL]) {
-    if (Context->ObjCProtoType.isNull())
-      Context->ObjCProtoType = GetType(Proto);
+    if (Context.ObjCProtoType.isNull())
+      Context.ObjCProtoType = GetType(Proto);
   }
   
   if (unsigned String = SpecialTypes[SPECIAL_TYPE_CF_CONSTANT_STRING]) {
-    if (!Context->CFConstantStringTypeDecl)
-      Context->setCFConstantStringType(GetType(String));
+    if (!Context.CFConstantStringTypeDecl)
+      Context.setCFConstantStringType(GetType(String));
   }
   
   if (unsigned File = SpecialTypes[SPECIAL_TYPE_FILE]) {
@@ -2859,16 +2834,16 @@ void ASTReader::InitializeContext(ASTContext &Ctx) {
       return;
     }
     
-    if (!Context->FILEDecl) {
+    if (!Context.FILEDecl) {
       if (const TypedefType *Typedef = FileType->getAs<TypedefType>())
-        Context->setFILEDecl(Typedef->getDecl());
+        Context.setFILEDecl(Typedef->getDecl());
       else {
         const TagType *Tag = FileType->getAs<TagType>();
         if (!Tag) {
           Error("Invalid FILE type in AST file");
           return;
         }
-        Context->setFILEDecl(Tag->getDecl());
+        Context.setFILEDecl(Tag->getDecl());
       }
     }
   }
@@ -2880,16 +2855,16 @@ void ASTReader::InitializeContext(ASTContext &Ctx) {
       return;
     }
     
-    if (!Context->jmp_bufDecl) {
+    if (!Context.jmp_bufDecl) {
       if (const TypedefType *Typedef = Jmp_bufType->getAs<TypedefType>())
-        Context->setjmp_bufDecl(Typedef->getDecl());
+        Context.setjmp_bufDecl(Typedef->getDecl());
       else {
         const TagType *Tag = Jmp_bufType->getAs<TagType>();
         if (!Tag) {
           Error("Invalid jmp_buf type in AST file");
           return;
         }
-        Context->setjmp_bufDecl(Tag->getDecl());
+        Context.setjmp_bufDecl(Tag->getDecl());
       }
     }
   }
@@ -2901,41 +2876,41 @@ void ASTReader::InitializeContext(ASTContext &Ctx) {
       return;
     }
     
-    if (!Context->sigjmp_bufDecl) {
+    if (!Context.sigjmp_bufDecl) {
       if (const TypedefType *Typedef = Sigjmp_bufType->getAs<TypedefType>())
-        Context->setsigjmp_bufDecl(Typedef->getDecl());
+        Context.setsigjmp_bufDecl(Typedef->getDecl());
       else {
         const TagType *Tag = Sigjmp_bufType->getAs<TagType>();
         assert(Tag && "Invalid sigjmp_buf type in AST file");
-        Context->setsigjmp_bufDecl(Tag->getDecl());
+        Context.setsigjmp_bufDecl(Tag->getDecl());
       }
     }
   }
 
   if (unsigned ObjCIdRedef
         = SpecialTypes[SPECIAL_TYPE_OBJC_ID_REDEFINITION]) {
-    if (Context->ObjCIdRedefinitionType.isNull())
-      Context->ObjCIdRedefinitionType = GetType(ObjCIdRedef);
+    if (Context.ObjCIdRedefinitionType.isNull())
+      Context.ObjCIdRedefinitionType = GetType(ObjCIdRedef);
   }
 
   if (unsigned ObjCClassRedef
         = SpecialTypes[SPECIAL_TYPE_OBJC_CLASS_REDEFINITION]) {
-    if (Context->ObjCClassRedefinitionType.isNull())
-      Context->ObjCClassRedefinitionType = GetType(ObjCClassRedef);
+    if (Context.ObjCClassRedefinitionType.isNull())
+      Context.ObjCClassRedefinitionType = GetType(ObjCClassRedef);
   }
 
   if (unsigned ObjCSelRedef
         = SpecialTypes[SPECIAL_TYPE_OBJC_SEL_REDEFINITION]) {
-    if (Context->ObjCSelRedefinitionType.isNull())
-      Context->ObjCSelRedefinitionType = GetType(ObjCSelRedef);
+    if (Context.ObjCSelRedefinitionType.isNull())
+      Context.ObjCSelRedefinitionType = GetType(ObjCSelRedef);
   }
 
-  ReadPragmaDiagnosticMappings(Context->getDiagnostics());
+  ReadPragmaDiagnosticMappings(Context.getDiagnostics());
 
   // If there were any CUDA special declarations, deserialize them.
   if (!CUDASpecialDeclRefs.empty()) {
     assert(CUDASpecialDeclRefs.size() == 1 && "More decl refs than expected!");
-    Context->setcudaConfigureCallDecl(
+    Context.setcudaConfigureCallDecl(
                            cast<FunctionDecl>(GetDecl(CUDASpecialDeclRefs[0])));
   }
 }
@@ -3271,7 +3246,7 @@ QualType ASTReader::readTypeRecord(unsigned Index) {
     }
     QualType Base = readType(*Loc.F, Record, Idx);
     Qualifiers Quals = Qualifiers::fromOpaqueValue(Record[Idx++]);
-    return Context->getQualifiedType(Base, Quals);
+    return Context.getQualifiedType(Base, Quals);
   }
 
   case TYPE_COMPLEX: {
@@ -3280,7 +3255,7 @@ QualType ASTReader::readTypeRecord(unsigned Index) {
       return QualType();
     }
     QualType ElemType = readType(*Loc.F, Record, Idx);
-    return Context->getComplexType(ElemType);
+    return Context.getComplexType(ElemType);
   }
 
   case TYPE_POINTER: {
@@ -3289,7 +3264,7 @@ QualType ASTReader::readTypeRecord(unsigned Index) {
       return QualType();
     }
     QualType PointeeType = readType(*Loc.F, Record, Idx);
-    return Context->getPointerType(PointeeType);
+    return Context.getPointerType(PointeeType);
   }
 
   case TYPE_BLOCK_POINTER: {
@@ -3298,7 +3273,7 @@ QualType ASTReader::readTypeRecord(unsigned Index) {
       return QualType();
     }
     QualType PointeeType = readType(*Loc.F, Record, Idx);
-    return Context->getBlockPointerType(PointeeType);
+    return Context.getBlockPointerType(PointeeType);
   }
 
   case TYPE_LVALUE_REFERENCE: {
@@ -3307,7 +3282,7 @@ QualType ASTReader::readTypeRecord(unsigned Index) {
       return QualType();
     }
     QualType PointeeType = readType(*Loc.F, Record, Idx);
-    return Context->getLValueReferenceType(PointeeType, Record[1]);
+    return Context.getLValueReferenceType(PointeeType, Record[1]);
   }
 
   case TYPE_RVALUE_REFERENCE: {
@@ -3316,7 +3291,7 @@ QualType ASTReader::readTypeRecord(unsigned Index) {
       return QualType();
     }
     QualType PointeeType = readType(*Loc.F, Record, Idx);
-    return Context->getRValueReferenceType(PointeeType);
+    return Context.getRValueReferenceType(PointeeType);
   }
 
   case TYPE_MEMBER_POINTER: {
@@ -3329,7 +3304,7 @@ QualType ASTReader::readTypeRecord(unsigned Index) {
     if (PointeeType.isNull() || ClassType.isNull())
       return QualType();
     
-    return Context->getMemberPointerType(PointeeType, ClassType.getTypePtr());
+    return Context.getMemberPointerType(PointeeType, ClassType.getTypePtr());
   }
 
   case TYPE_CONSTANT_ARRAY: {
@@ -3338,7 +3313,7 @@ QualType ASTReader::readTypeRecord(unsigned Index) {
     unsigned IndexTypeQuals = Record[2];
     unsigned Idx = 3;
     llvm::APInt Size = ReadAPInt(Record, Idx);
-    return Context->getConstantArrayType(ElementType, Size,
+    return Context.getConstantArrayType(ElementType, Size,
                                          ASM, IndexTypeQuals);
   }
 
@@ -3346,7 +3321,7 @@ QualType ASTReader::readTypeRecord(unsigned Index) {
     QualType ElementType = readType(*Loc.F, Record, Idx);
     ArrayType::ArraySizeModifier ASM = (ArrayType::ArraySizeModifier)Record[1];
     unsigned IndexTypeQuals = Record[2];
-    return Context->getIncompleteArrayType(ElementType, ASM, IndexTypeQuals);
+    return Context.getIncompleteArrayType(ElementType, ASM, IndexTypeQuals);
   }
 
   case TYPE_VARIABLE_ARRAY: {
@@ -3355,7 +3330,7 @@ QualType ASTReader::readTypeRecord(unsigned Index) {
     unsigned IndexTypeQuals = Record[2];
     SourceLocation LBLoc = ReadSourceLocation(*Loc.F, Record[3]);
     SourceLocation RBLoc = ReadSourceLocation(*Loc.F, Record[4]);
-    return Context->getVariableArrayType(ElementType, ReadExpr(*Loc.F),
+    return Context.getVariableArrayType(ElementType, ReadExpr(*Loc.F),
                                          ASM, IndexTypeQuals,
                                          SourceRange(LBLoc, RBLoc));
   }
@@ -3369,7 +3344,7 @@ QualType ASTReader::readTypeRecord(unsigned Index) {
     QualType ElementType = readType(*Loc.F, Record, Idx);
     unsigned NumElements = Record[1];
     unsigned VecKind = Record[2];
-    return Context->getVectorType(ElementType, NumElements,
+    return Context.getVectorType(ElementType, NumElements,
                                   (VectorType::VectorKind)VecKind);
   }
 
@@ -3381,7 +3356,7 @@ QualType ASTReader::readTypeRecord(unsigned Index) {
 
     QualType ElementType = readType(*Loc.F, Record, Idx);
     unsigned NumElements = Record[1];
-    return Context->getExtVectorType(ElementType, NumElements);
+    return Context.getExtVectorType(ElementType, NumElements);
   }
 
   case TYPE_FUNCTION_NO_PROTO: {
@@ -3392,7 +3367,7 @@ QualType ASTReader::readTypeRecord(unsigned Index) {
     QualType ResultType = readType(*Loc.F, Record, Idx);
     FunctionType::ExtInfo Info(Record[1], Record[2], Record[3],
                                (CallingConv)Record[4], Record[5]);
-    return Context->getFunctionNoProtoType(ResultType, Info);
+    return Context.getFunctionNoProtoType(ResultType, Info);
   }
 
   case TYPE_FUNCTION_PROTO: {
@@ -3426,13 +3401,13 @@ QualType ASTReader::readTypeRecord(unsigned Index) {
     } else if (EST == EST_ComputedNoexcept) {
       EPI.NoexceptExpr = ReadExpr(*Loc.F);
     }
-    return Context->getFunctionType(ResultType, ParamTypes.data(), NumParams,
+    return Context.getFunctionType(ResultType, ParamTypes.data(), NumParams,
                                     EPI);
   }
 
   case TYPE_UNRESOLVED_USING: {
     unsigned Idx = 0;
-    return Context->getTypeDeclType(
+    return Context.getTypeDeclType(
                   ReadDeclAs<UnresolvedUsingTypenameDecl>(*Loc.F, Record, Idx));
   }
       
@@ -3445,12 +3420,12 @@ QualType ASTReader::readTypeRecord(unsigned Index) {
     TypedefNameDecl *Decl = ReadDeclAs<TypedefNameDecl>(*Loc.F, Record, Idx);
     QualType Canonical = readType(*Loc.F, Record, Idx);
     if (!Canonical.isNull())
-      Canonical = Context->getCanonicalType(Canonical);
-    return Context->getTypedefType(Decl, Canonical);
+      Canonical = Context.getCanonicalType(Canonical);
+    return Context.getTypedefType(Decl, Canonical);
   }
 
   case TYPE_TYPEOF_EXPR:
-    return Context->getTypeOfExprType(ReadExpr(*Loc.F));
+    return Context.getTypeOfExprType(ReadExpr(*Loc.F));
 
   case TYPE_TYPEOF: {
     if (Record.size() != 1) {
@@ -3458,21 +3433,21 @@ QualType ASTReader::readTypeRecord(unsigned Index) {
       return QualType();
     }
     QualType UnderlyingType = readType(*Loc.F, Record, Idx);
-    return Context->getTypeOfType(UnderlyingType);
+    return Context.getTypeOfType(UnderlyingType);
   }
 
   case TYPE_DECLTYPE:
-    return Context->getDecltypeType(ReadExpr(*Loc.F));
+    return Context.getDecltypeType(ReadExpr(*Loc.F));
 
   case TYPE_UNARY_TRANSFORM: {
     QualType BaseType = readType(*Loc.F, Record, Idx);
     QualType UnderlyingType = readType(*Loc.F, Record, Idx);
     UnaryTransformType::UTTKind UKind = (UnaryTransformType::UTTKind)Record[2];
-    return Context->getUnaryTransformType(BaseType, UnderlyingType, UKind);
+    return Context.getUnaryTransformType(BaseType, UnderlyingType, UKind);
   }
 
   case TYPE_AUTO:
-    return Context->getAutoType(readType(*Loc.F, Record, Idx));
+    return Context.getAutoType(readType(*Loc.F, Record, Idx));
 
   case TYPE_RECORD: {
     if (Record.size() != 2) {
@@ -3482,7 +3457,7 @@ QualType ASTReader::readTypeRecord(unsigned Index) {
     unsigned Idx = 0;
     bool IsDependent = Record[Idx++];
     QualType T
-      = Context->getRecordType(ReadDeclAs<RecordDecl>(*Loc.F, Record, Idx));
+      = Context.getRecordType(ReadDeclAs<RecordDecl>(*Loc.F, Record, Idx));
     const_cast<Type*>(T.getTypePtr())->setDependent(IsDependent);
     return T;
   }
@@ -3495,7 +3470,7 @@ QualType ASTReader::readTypeRecord(unsigned Index) {
     unsigned Idx = 0;
     bool IsDependent = Record[Idx++];
     QualType T
-      = Context->getEnumType(ReadDeclAs<EnumDecl>(*Loc.F, Record, Idx));
+      = Context.getEnumType(ReadDeclAs<EnumDecl>(*Loc.F, Record, Idx));
     const_cast<Type*>(T.getTypePtr())->setDependent(IsDependent);
     return T;
   }
@@ -3508,7 +3483,7 @@ QualType ASTReader::readTypeRecord(unsigned Index) {
     QualType modifiedType = readType(*Loc.F, Record, Idx);
     QualType equivalentType = readType(*Loc.F, Record, Idx);
     AttributedType::Kind kind = static_cast<AttributedType::Kind>(Record[2]);
-    return Context->getAttributedType(kind, modifiedType, equivalentType);
+    return Context.getAttributedType(kind, modifiedType, equivalentType);
   }
 
   case TYPE_PAREN: {
@@ -3517,7 +3492,7 @@ QualType ASTReader::readTypeRecord(unsigned Index) {
       return QualType();
     }
     QualType InnerType = readType(*Loc.F, Record, Idx);
-    return Context->getParenType(InnerType);
+    return Context.getParenType(InnerType);
   }
 
   case TYPE_PACK_EXPANSION: {
@@ -3531,7 +3506,7 @@ QualType ASTReader::readTypeRecord(unsigned Index) {
     llvm::Optional<unsigned> NumExpansions;
     if (Record[1])
       NumExpansions = Record[1] - 1;
-    return Context->getPackExpansionType(Pattern, NumExpansions);
+    return Context.getPackExpansionType(Pattern, NumExpansions);
   }
 
   case TYPE_ELABORATED: {
@@ -3539,14 +3514,14 @@ QualType ASTReader::readTypeRecord(unsigned Index) {
     ElaboratedTypeKeyword Keyword = (ElaboratedTypeKeyword)Record[Idx++];
     NestedNameSpecifier *NNS = ReadNestedNameSpecifier(*Loc.F, Record, Idx);
     QualType NamedType = readType(*Loc.F, Record, Idx);
-    return Context->getElaboratedType(Keyword, NNS, NamedType);
+    return Context.getElaboratedType(Keyword, NNS, NamedType);
   }
 
   case TYPE_OBJC_INTERFACE: {
     unsigned Idx = 0;
     ObjCInterfaceDecl *ItfD
       = ReadDeclAs<ObjCInterfaceDecl>(*Loc.F, Record, Idx);
-    return Context->getObjCInterfaceType(ItfD);
+    return Context.getObjCInterfaceType(ItfD);
   }
 
   case TYPE_OBJC_OBJECT: {
@@ -3556,13 +3531,13 @@ QualType ASTReader::readTypeRecord(unsigned Index) {
     SmallVector<ObjCProtocolDecl*, 4> Protos;
     for (unsigned I = 0; I != NumProtos; ++I)
       Protos.push_back(ReadDeclAs<ObjCProtocolDecl>(*Loc.F, Record, Idx));
-    return Context->getObjCObjectType(Base, Protos.data(), NumProtos);
+    return Context.getObjCObjectType(Base, Protos.data(), NumProtos);
   }
 
   case TYPE_OBJC_OBJECT_POINTER: {
     unsigned Idx = 0;
     QualType Pointee = readType(*Loc.F, Record, Idx);
-    return Context->getObjCObjectPointerType(Pointee);
+    return Context.getObjCObjectPointerType(Pointee);
   }
 
   case TYPE_SUBST_TEMPLATE_TYPE_PARM: {
@@ -3570,7 +3545,7 @@ QualType ASTReader::readTypeRecord(unsigned Index) {
     QualType Parm = readType(*Loc.F, Record, Idx);
     QualType Replacement = readType(*Loc.F, Record, Idx);
     return
-      Context->getSubstTemplateTypeParmType(cast<TemplateTypeParmType>(Parm),
+      Context.getSubstTemplateTypeParmType(cast<TemplateTypeParmType>(Parm),
                                             Replacement);
   }
 
@@ -3578,7 +3553,7 @@ QualType ASTReader::readTypeRecord(unsigned Index) {
     unsigned Idx = 0;
     QualType Parm = readType(*Loc.F, Record, Idx);
     TemplateArgument ArgPack = ReadTemplateArgument(*Loc.F, Record, Idx);
-    return Context->getSubstTemplateTypeParmPackType(
+    return Context.getSubstTemplateTypeParmPackType(
                                                cast<TemplateTypeParmType>(Parm),
                                                      ArgPack);
   }
@@ -3589,7 +3564,7 @@ QualType ASTReader::readTypeRecord(unsigned Index) {
     // FIXME: ASTContext::getInjectedClassNameType is not currently suitable
     // for AST reading, too much interdependencies.
     return
-      QualType(new (*Context, TypeAlignment) InjectedClassNameType(D, TST), 0);
+      QualType(new (Context, TypeAlignment) InjectedClassNameType(D, TST), 0);
   }
 
   case TYPE_TEMPLATE_TYPE_PARM: {
@@ -3599,7 +3574,7 @@ QualType ASTReader::readTypeRecord(unsigned Index) {
     bool Pack = Record[Idx++];
     TemplateTypeParmDecl *D
       = ReadDeclAs<TemplateTypeParmDecl>(*Loc.F, Record, Idx);
-    return Context->getTemplateTypeParmType(Depth, Index, Pack, D);
+    return Context.getTemplateTypeParmType(Depth, Index, Pack, D);
   }
 
   case TYPE_DEPENDENT_NAME: {
@@ -3609,8 +3584,8 @@ QualType ASTReader::readTypeRecord(unsigned Index) {
     const IdentifierInfo *Name = this->GetIdentifierInfo(*Loc.F, Record, Idx);
     QualType Canon = readType(*Loc.F, Record, Idx);
     if (!Canon.isNull())
-      Canon = Context->getCanonicalType(Canon);
-    return Context->getDependentNameType(Keyword, NNS, Name, Canon);
+      Canon = Context.getCanonicalType(Canon);
+    return Context.getDependentNameType(Keyword, NNS, Name, Canon);
   }
 
   case TYPE_DEPENDENT_TEMPLATE_SPECIALIZATION: {
@@ -3623,7 +3598,7 @@ QualType ASTReader::readTypeRecord(unsigned Index) {
     Args.reserve(NumArgs);
     while (NumArgs--)
       Args.push_back(ReadTemplateArgument(*Loc.F, Record, Idx));
-    return Context->getDependentTemplateSpecializationType(Keyword, NNS, Name,
+    return Context.getDependentTemplateSpecializationType(Keyword, NNS, Name,
                                                       Args.size(), Args.data());
   }
 
@@ -3640,7 +3615,7 @@ QualType ASTReader::readTypeRecord(unsigned Index) {
     Expr *NumElts = ReadExpr(*Loc.F);
     SourceRange Brackets = ReadSourceRange(*Loc.F, Record, Idx);
 
-    return Context->getDependentSizedArrayType(ElementType, NumElts, ASM,
+    return Context.getDependentSizedArrayType(ElementType, NumElts, ASM,
                                                IndexTypeQuals, Brackets);
   }
 
@@ -3653,10 +3628,10 @@ QualType ASTReader::readTypeRecord(unsigned Index) {
     QualType Underlying = readType(*Loc.F, Record, Idx);
     QualType T;
     if (Underlying.isNull())
-      T = Context->getCanonicalTemplateSpecializationType(Name, Args.data(),
+      T = Context.getCanonicalTemplateSpecializationType(Name, Args.data(),
                                                           Args.size());
     else
-      T = Context->getTemplateSpecializationType(Name, Args.data(),
+      T = Context.getTemplateSpecializationType(Name, Args.data(),
                                                  Args.size(), Underlying);
     const_cast<Type*>(T.getTypePtr())->setDependent(IsDependent);
     return T;
@@ -3903,7 +3878,7 @@ TypeSourceInfo *ASTReader::GetTypeSourceInfo(Module &F,
   if (InfoTy.isNull())
     return 0;
 
-  TypeSourceInfo *TInfo = getContext()->CreateTypeSourceInfo(InfoTy);
+  TypeSourceInfo *TInfo = getContext().CreateTypeSourceInfo(InfoTy);
   TypeLocReader TLR(*this, F, Record, Idx);
   for (TypeLoc TL = TInfo->getTypeLoc(); !TL.isNull(); TL = TL.getNextTypeLoc())
     TLR.Visit(TL);
@@ -3918,45 +3893,45 @@ QualType ASTReader::GetType(TypeID ID) {
     QualType T;
     switch ((PredefinedTypeIDs)Index) {
     case PREDEF_TYPE_NULL_ID: return QualType();
-    case PREDEF_TYPE_VOID_ID: T = Context->VoidTy; break;
-    case PREDEF_TYPE_BOOL_ID: T = Context->BoolTy; break;
+    case PREDEF_TYPE_VOID_ID: T = Context.VoidTy; break;
+    case PREDEF_TYPE_BOOL_ID: T = Context.BoolTy; break;
 
     case PREDEF_TYPE_CHAR_U_ID:
     case PREDEF_TYPE_CHAR_S_ID:
       // FIXME: Check that the signedness of CharTy is correct!
-      T = Context->CharTy;
+      T = Context.CharTy;
       break;
 
-    case PREDEF_TYPE_UCHAR_ID:      T = Context->UnsignedCharTy;     break;
-    case PREDEF_TYPE_USHORT_ID:     T = Context->UnsignedShortTy;    break;
-    case PREDEF_TYPE_UINT_ID:       T = Context->UnsignedIntTy;      break;
-    case PREDEF_TYPE_ULONG_ID:      T = Context->UnsignedLongTy;     break;
-    case PREDEF_TYPE_ULONGLONG_ID:  T = Context->UnsignedLongLongTy; break;
-    case PREDEF_TYPE_UINT128_ID:    T = Context->UnsignedInt128Ty;   break;
-    case PREDEF_TYPE_SCHAR_ID:      T = Context->SignedCharTy;       break;
-    case PREDEF_TYPE_WCHAR_ID:      T = Context->WCharTy;            break;
-    case PREDEF_TYPE_SHORT_ID:      T = Context->ShortTy;            break;
-    case PREDEF_TYPE_INT_ID:        T = Context->IntTy;              break;
-    case PREDEF_TYPE_LONG_ID:       T = Context->LongTy;             break;
-    case PREDEF_TYPE_LONGLONG_ID:   T = Context->LongLongTy;         break;
-    case PREDEF_TYPE_INT128_ID:     T = Context->Int128Ty;           break;
-    case PREDEF_TYPE_FLOAT_ID:      T = Context->FloatTy;            break;
-    case PREDEF_TYPE_DOUBLE_ID:     T = Context->DoubleTy;           break;
-    case PREDEF_TYPE_LONGDOUBLE_ID: T = Context->LongDoubleTy;       break;
-    case PREDEF_TYPE_OVERLOAD_ID:   T = Context->OverloadTy;         break;
-    case PREDEF_TYPE_BOUND_MEMBER:  T = Context->BoundMemberTy;      break;
-    case PREDEF_TYPE_DEPENDENT_ID:  T = Context->DependentTy;        break;
-    case PREDEF_TYPE_UNKNOWN_ANY:   T = Context->UnknownAnyTy;       break;
-    case PREDEF_TYPE_NULLPTR_ID:    T = Context->NullPtrTy;          break;
-    case PREDEF_TYPE_CHAR16_ID:     T = Context->Char16Ty;           break;
-    case PREDEF_TYPE_CHAR32_ID:     T = Context->Char32Ty;           break;
-    case PREDEF_TYPE_OBJC_ID:       T = Context->ObjCBuiltinIdTy;    break;
-    case PREDEF_TYPE_OBJC_CLASS:    T = Context->ObjCBuiltinClassTy; break;
-    case PREDEF_TYPE_OBJC_SEL:      T = Context->ObjCBuiltinSelTy;   break;
-    case PREDEF_TYPE_AUTO_DEDUCT:   T = Context->getAutoDeductType(); break;
+    case PREDEF_TYPE_UCHAR_ID:      T = Context.UnsignedCharTy;     break;
+    case PREDEF_TYPE_USHORT_ID:     T = Context.UnsignedShortTy;    break;
+    case PREDEF_TYPE_UINT_ID:       T = Context.UnsignedIntTy;      break;
+    case PREDEF_TYPE_ULONG_ID:      T = Context.UnsignedLongTy;     break;
+    case PREDEF_TYPE_ULONGLONG_ID:  T = Context.UnsignedLongLongTy; break;
+    case PREDEF_TYPE_UINT128_ID:    T = Context.UnsignedInt128Ty;   break;
+    case PREDEF_TYPE_SCHAR_ID:      T = Context.SignedCharTy;       break;
+    case PREDEF_TYPE_WCHAR_ID:      T = Context.WCharTy;            break;
+    case PREDEF_TYPE_SHORT_ID:      T = Context.ShortTy;            break;
+    case PREDEF_TYPE_INT_ID:        T = Context.IntTy;              break;
+    case PREDEF_TYPE_LONG_ID:       T = Context.LongTy;             break;
+    case PREDEF_TYPE_LONGLONG_ID:   T = Context.LongLongTy;         break;
+    case PREDEF_TYPE_INT128_ID:     T = Context.Int128Ty;           break;
+    case PREDEF_TYPE_FLOAT_ID:      T = Context.FloatTy;            break;
+    case PREDEF_TYPE_DOUBLE_ID:     T = Context.DoubleTy;           break;
+    case PREDEF_TYPE_LONGDOUBLE_ID: T = Context.LongDoubleTy;       break;
+    case PREDEF_TYPE_OVERLOAD_ID:   T = Context.OverloadTy;         break;
+    case PREDEF_TYPE_BOUND_MEMBER:  T = Context.BoundMemberTy;      break;
+    case PREDEF_TYPE_DEPENDENT_ID:  T = Context.DependentTy;        break;
+    case PREDEF_TYPE_UNKNOWN_ANY:   T = Context.UnknownAnyTy;       break;
+    case PREDEF_TYPE_NULLPTR_ID:    T = Context.NullPtrTy;          break;
+    case PREDEF_TYPE_CHAR16_ID:     T = Context.Char16Ty;           break;
+    case PREDEF_TYPE_CHAR32_ID:     T = Context.Char32Ty;           break;
+    case PREDEF_TYPE_OBJC_ID:       T = Context.ObjCBuiltinIdTy;    break;
+    case PREDEF_TYPE_OBJC_CLASS:    T = Context.ObjCBuiltinClassTy; break;
+    case PREDEF_TYPE_OBJC_SEL:      T = Context.ObjCBuiltinSelTy;   break;
+    case PREDEF_TYPE_AUTO_DEDUCT:   T = Context.getAutoDeductType(); break;
         
     case PREDEF_TYPE_AUTO_RREF_DEDUCT: 
-      T = Context->getAutoRRefDeductType(); 
+      T = Context.getAutoRRefDeductType(); 
       break;
     }
 
@@ -4077,7 +4052,7 @@ CXXBaseSpecifier *ASTReader::GetExternalCXXBaseSpecifiers(uint64_t Offset) {
 
   unsigned Idx = 0;
   unsigned NumBases = Record[Idx++];
-  void *Mem = Context->Allocate(sizeof(CXXBaseSpecifier) * NumBases);
+  void *Mem = Context.Allocate(sizeof(CXXBaseSpecifier) * NumBases);
   CXXBaseSpecifier *Bases = new (Mem) CXXBaseSpecifier [NumBases];
   for (unsigned I = 0; I != NumBases; ++I)
     Bases[I] = ReadCXXBaseSpecifier(*Loc.F, Record, Idx);
@@ -4110,32 +4085,25 @@ Decl *ASTReader::GetDecl(DeclID ID) {
       return 0;
         
     case PREDEF_DECL_TRANSLATION_UNIT_ID:
-      assert(Context && "No context available?");
-      return Context->getTranslationUnitDecl();
+      return Context.getTranslationUnitDecl();
         
     case PREDEF_DECL_OBJC_ID_ID:
-      assert(Context && "No context available?");
-      return Context->getObjCIdDecl();
+      return Context.getObjCIdDecl();
 
     case PREDEF_DECL_OBJC_SEL_ID:
-      assert(Context && "No context available?");
-      return Context->getObjCSelDecl();
+      return Context.getObjCSelDecl();
 
     case PREDEF_DECL_OBJC_CLASS_ID:
-      assert(Context && "No context available?");
-      return Context->getObjCClassDecl();
+      return Context.getObjCClassDecl();
         
     case PREDEF_DECL_INT_128_ID:
-      assert(Context && "No context available?");
-      return Context->getInt128Decl();
+      return Context.getInt128Decl();
 
     case PREDEF_DECL_UNSIGNED_INT_128_ID:
-      assert(Context && "No context available?");
-      return Context->getUInt128Decl();
+      return Context.getUInt128Decl();
         
     case PREDEF_DECL_OBJC_INSTANCETYPE_ID:
-      assert(Context && "No context available?");
-      return Context->getObjCInstanceTypeDecl();
+      return Context.getObjCInstanceTypeDecl();
     }
     
     return 0;
@@ -4981,23 +4949,23 @@ ASTReader::ReadDeclarationName(Module &F,
     return DeclarationName(ReadSelector(F, Record, Idx));
 
   case DeclarationName::CXXConstructorName:
-    return Context->DeclarationNames.getCXXConstructorName(
-                          Context->getCanonicalType(readType(F, Record, Idx)));
+    return Context.DeclarationNames.getCXXConstructorName(
+                          Context.getCanonicalType(readType(F, Record, Idx)));
 
   case DeclarationName::CXXDestructorName:
-    return Context->DeclarationNames.getCXXDestructorName(
-                          Context->getCanonicalType(readType(F, Record, Idx)));
+    return Context.DeclarationNames.getCXXDestructorName(
+                          Context.getCanonicalType(readType(F, Record, Idx)));
 
   case DeclarationName::CXXConversionFunctionName:
-    return Context->DeclarationNames.getCXXConversionFunctionName(
-                          Context->getCanonicalType(readType(F, Record, Idx)));
+    return Context.DeclarationNames.getCXXConversionFunctionName(
+                          Context.getCanonicalType(readType(F, Record, Idx)));
 
   case DeclarationName::CXXOperatorName:
-    return Context->DeclarationNames.getCXXOperatorName(
+    return Context.DeclarationNames.getCXXOperatorName(
                                        (OverloadedOperatorKind)Record[Idx++]);
 
   case DeclarationName::CXXLiteralOperatorName:
-    return Context->DeclarationNames.getCXXLiteralOperatorName(
+    return Context.DeclarationNames.getCXXLiteralOperatorName(
                                        GetIdentifierInfo(F, Record, Idx));
 
   case DeclarationName::CXXUsingDirective:
@@ -5056,7 +5024,7 @@ void ASTReader::ReadQualifierInfo(Module &F, QualifierInfo &Info,
   unsigned NumTPLists = Record[Idx++];
   Info.NumTemplParamLists = NumTPLists;
   if (NumTPLists) {
-    Info.TemplParamLists = new (*Context) TemplateParameterList*[NumTPLists];
+    Info.TemplParamLists = new (Context) TemplateParameterList*[NumTPLists];
     for (unsigned i=0; i != NumTPLists; ++i)
       Info.TemplParamLists[i] = ReadTemplateParameterList(F, Record, Idx);
   }
@@ -5076,23 +5044,23 @@ ASTReader::ReadTemplateName(Module &F, const RecordData &Record,
     while (size--)
       Decls.addDecl(ReadDeclAs<NamedDecl>(F, Record, Idx));
 
-    return Context->getOverloadedTemplateName(Decls.begin(), Decls.end());
+    return Context.getOverloadedTemplateName(Decls.begin(), Decls.end());
   }
 
   case TemplateName::QualifiedTemplate: {
     NestedNameSpecifier *NNS = ReadNestedNameSpecifier(F, Record, Idx);
     bool hasTemplKeyword = Record[Idx++];
     TemplateDecl *Template = ReadDeclAs<TemplateDecl>(F, Record, Idx);
-    return Context->getQualifiedTemplateName(NNS, hasTemplKeyword, Template);
+    return Context.getQualifiedTemplateName(NNS, hasTemplKeyword, Template);
   }
 
   case TemplateName::DependentTemplate: {
     NestedNameSpecifier *NNS = ReadNestedNameSpecifier(F, Record, Idx);
     if (Record[Idx++])  // isIdentifier
-      return Context->getDependentTemplateName(NNS,
+      return Context.getDependentTemplateName(NNS,
                                                GetIdentifierInfo(F, Record, 
                                                                  Idx));
-    return Context->getDependentTemplateName(NNS,
+    return Context.getDependentTemplateName(NNS,
                                          (OverloadedOperatorKind)Record[Idx++]);
   }
 
@@ -5101,7 +5069,7 @@ ASTReader::ReadTemplateName(Module &F, const RecordData &Record,
       = ReadDeclAs<TemplateTemplateParmDecl>(F, Record, Idx);
     if (!param) return TemplateName();
     TemplateName replacement = ReadTemplateName(F, Record, Idx);
-    return Context->getSubstTemplateTemplateParm(param, replacement);
+    return Context.getSubstTemplateTemplateParm(param, replacement);
   }
       
   case TemplateName::SubstTemplateTemplateParmPack: {
@@ -5114,7 +5082,7 @@ ASTReader::ReadTemplateName(Module &F, const RecordData &Record,
     if (ArgPack.getKind() != TemplateArgument::Pack)
       return TemplateName();
     
-    return Context->getSubstTemplateTemplateParmPack(Param, ArgPack);
+    return Context.getSubstTemplateTemplateParmPack(Param, ArgPack);
   }
   }
 
@@ -5151,7 +5119,7 @@ ASTReader::ReadTemplateArgument(Module &F,