--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/clang/lib/CodeGen/MicrosoftCXXABI.cpp	Thu Feb 13 15:10:13 2020 +0900
@@ -0,0 +1,4333 @@
+//===--- MicrosoftCXXABI.cpp - Emit LLVM Code from ASTs for a Module ------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This provides C++ code generation targeting the Microsoft Visual C++ ABI.
+// The class in this file generates structures that follow the Microsoft
+// Visual C++ ABI, which is actually not very well documented at all outside
+// of Microsoft.
+//
+//===----------------------------------------------------------------------===//
+
+#include "CGCXXABI.h"
+#include "CGCleanup.h"
+#include "CGVTables.h"
+#include "CodeGenModule.h"
+#include "CodeGenTypes.h"
+#include "TargetInfo.h"
+#include "clang/AST/Attr.h"
+#include "clang/AST/CXXInheritance.h"
+#include "clang/AST/Decl.h"
+#include "clang/AST/DeclCXX.h"
+#include "clang/AST/StmtCXX.h"
+#include "clang/AST/VTableBuilder.h"
+#include "clang/CodeGen/ConstantInitBuilder.h"
+#include "llvm/ADT/StringExtras.h"
+#include "llvm/ADT/StringSet.h"
+#include "llvm/IR/Intrinsics.h"
+
+using namespace clang;
+using namespace CodeGen;
+
+namespace {
+
+/// Holds all the vbtable globals for a given class.
+struct VBTableGlobals {
+  const VPtrInfoVector *VBTables;
+  SmallVector<llvm::GlobalVariable *, 2> Globals;
+};
+
+class MicrosoftCXXABI : public CGCXXABI {
+public:
+  MicrosoftCXXABI(CodeGenModule &CGM)
+      : CGCXXABI(CGM), BaseClassDescriptorType(nullptr),
+        ClassHierarchyDescriptorType(nullptr),
+        CompleteObjectLocatorType(nullptr), CatchableTypeType(nullptr),
+        ThrowInfoType(nullptr) {}
+
+  bool HasThisReturn(GlobalDecl GD) const override;
+  bool hasMostDerivedReturn(GlobalDecl GD) const override;
+
+  bool classifyReturnType(CGFunctionInfo &FI) const override;
+
+  RecordArgABI getRecordArgABI(const CXXRecordDecl *RD) const override;
+
+  bool isSRetParameterAfterThis() const override { return true; }
+
+  bool isThisCompleteObject(GlobalDecl GD) const override {
+    // The Microsoft ABI doesn't use separate complete-object vs.
+    // base-object variants of constructors, but it does of destructors.
+    if (isa<CXXDestructorDecl>(GD.getDecl())) {
+      switch (GD.getDtorType()) {
+      case Dtor_Complete:
+      case Dtor_Deleting:
+        return true;
+
+      case Dtor_Base:
+        return false;
+
+      case Dtor_Comdat: llvm_unreachable("emitting dtor comdat as function?");
+      }
+      llvm_unreachable("bad dtor kind");
+    }
+
+    // No other kinds.
+    return false;
+  }
+
+  size_t getSrcArgforCopyCtor(const CXXConstructorDecl *CD,
+                              FunctionArgList &Args) const override {
+    assert(Args.size() >= 2 &&
+           "expected the arglist to have at least two args!");
+    // The 'most_derived' parameter goes second if the ctor is variadic and
+    // has v-bases.
+    if (CD->getParent()->getNumVBases() > 0 &&
+        CD->getType()->castAs<FunctionProtoType>()->isVariadic())
+      return 2;
+    return 1;
+  }
+
+  std::vector<CharUnits> getVBPtrOffsets(const CXXRecordDecl *RD) override {
+    std::vector<CharUnits> VBPtrOffsets;
+    const ASTContext &Context = getContext();
+    const ASTRecordLayout &Layout = Context.getASTRecordLayout(RD);
+
+    const VBTableGlobals &VBGlobals = enumerateVBTables(RD);
+    for (const std::unique_ptr<VPtrInfo> &VBT : *VBGlobals.VBTables) {
+      const ASTRecordLayout &SubobjectLayout =
+          Context.getASTRecordLayout(VBT->IntroducingObject);
+      CharUnits Offs = VBT->NonVirtualOffset;
+      Offs += SubobjectLayout.getVBPtrOffset();
+      if (VBT->getVBaseWithVPtr())
+        Offs += Layout.getVBaseClassOffset(VBT->getVBaseWithVPtr());
+      VBPtrOffsets.push_back(Offs);
+    }
+    llvm::array_pod_sort(VBPtrOffsets.begin(), VBPtrOffsets.end());
+    return VBPtrOffsets;
+  }
+
+  StringRef GetPureVirtualCallName() override { return "_purecall"; }
+  StringRef GetDeletedVirtualCallName() override { return "_purecall"; }
+
+  void emitVirtualObjectDelete(CodeGenFunction &CGF, const CXXDeleteExpr *DE,
+                               Address Ptr, QualType ElementType,
+                               const CXXDestructorDecl *Dtor) override;
+
+  void emitRethrow(CodeGenFunction &CGF, bool isNoReturn) override;
+  void emitThrow(CodeGenFunction &CGF, const CXXThrowExpr *E) override;
+
+  void emitBeginCatch(CodeGenFunction &CGF, const CXXCatchStmt *C) override;
+
+  llvm::GlobalVariable *getMSCompleteObjectLocator(const CXXRecordDecl *RD,
+                                                   const VPtrInfo &Info);
+
+  llvm::Constant *getAddrOfRTTIDescriptor(QualType Ty) override;
+  CatchTypeInfo
+  getAddrOfCXXCatchHandlerType(QualType Ty, QualType CatchHandlerType) override;
+
+  /// MSVC needs an extra flag to indicate a catchall.
+  CatchTypeInfo getCatchAllTypeInfo() override {
+    return CatchTypeInfo{nullptr, 0x40};
+  }
+
+  bool shouldTypeidBeNullChecked(bool IsDeref, QualType SrcRecordTy) override;
+  void EmitBadTypeidCall(CodeGenFunction &CGF) override;
+  llvm::Value *EmitTypeid(CodeGenFunction &CGF, QualType SrcRecordTy,
+                          Address ThisPtr,
+                          llvm::Type *StdTypeInfoPtrTy) override;
+
+  bool shouldDynamicCastCallBeNullChecked(bool SrcIsPtr,
+                                          QualType SrcRecordTy) override;
+
+  llvm::Value *EmitDynamicCastCall(CodeGenFunction &CGF, Address Value,
+                                   QualType SrcRecordTy, QualType DestTy,
+                                   QualType DestRecordTy,
+                                   llvm::BasicBlock *CastEnd) override;
+
+  llvm::Value *EmitDynamicCastToVoid(CodeGenFunction &CGF, Address Value,
+                                     QualType SrcRecordTy,
+                                     QualType DestTy) override;
+
+  bool EmitBadCastCall(CodeGenFunction &CGF) override;
+  bool canSpeculativelyEmitVTable(const CXXRecordDecl *RD) const override {
+    return false;
+  }
+
+  llvm::Value *
+  GetVirtualBaseClassOffset(CodeGenFunction &CGF, Address This,
+                            const CXXRecordDecl *ClassDecl,
+                            const CXXRecordDecl *BaseClassDecl) override;
+
+  llvm::BasicBlock *
+  EmitCtorCompleteObjectHandler(CodeGenFunction &CGF,
+                                const CXXRecordDecl *RD) override;
+
+  llvm::BasicBlock *
+  EmitDtorCompleteObjectHandler(CodeGenFunction &CGF);
+
+  void initializeHiddenVirtualInheritanceMembers(CodeGenFunction &CGF,
+                                              const CXXRecordDecl *RD) override;
+
+  void EmitCXXConstructors(const CXXConstructorDecl *D) override;
+
+  // Background on MSVC destructors
+  // ==============================
+  //
+  // Both Itanium and MSVC ABIs have destructor variants.  The variant names
+  // roughly correspond in the following way:
+  //   Itanium       Microsoft
+  //   Base       -> no name, just ~Class
+  //   Complete   -> vbase destructor
+  //   Deleting   -> scalar deleting destructor
+  //                 vector deleting destructor
+  //
+  // The base and complete destructors are the same as in Itanium, although the
+  // complete destructor does not accept a VTT parameter when there are virtual
+  // bases.  A separate mechanism involving vtordisps is used to ensure that
+  // virtual methods of destroyed subobjects are not called.
+  //
+  // The deleting destructors accept an i32 bitfield as a second parameter.  Bit
+  // 1 indicates if the memory should be deleted.  Bit 2 indicates if the this
+  // pointer points to an array.  The scalar deleting destructor assumes that
+  // bit 2 is zero, and therefore does not contain a loop.
+  //
+  // For virtual destructors, only one entry is reserved in the vftable, and it
+  // always points to the vector deleting destructor.  The vector deleting
+  // destructor is the most general, so it can be used to destroy objects in
+  // place, delete single heap objects, or delete arrays.
+  //
+  // A TU defining a non-inline destructor is only guaranteed to emit a base
+  // destructor, and all of the other variants are emitted on an as-needed basis
+  // in COMDATs.  Because a non-base destructor can be emitted in a TU that
+  // lacks a definition for the destructor, non-base destructors must always
+  // delegate to or alias the base destructor.
+
+  AddedStructorArgs
+  buildStructorSignature(GlobalDecl GD,
+                         SmallVectorImpl<CanQualType> &ArgTys) override;
+
+  /// Non-base dtors should be emitted as delegating thunks in this ABI.
+  bool useThunkForDtorVariant(const CXXDestructorDecl *Dtor,
+                              CXXDtorType DT) const override {
+    return DT != Dtor_Base;
+  }
+
+  void setCXXDestructorDLLStorage(llvm::GlobalValue *GV,
+                                  const CXXDestructorDecl *Dtor,
+                                  CXXDtorType DT) const override;
+
+  llvm::GlobalValue::LinkageTypes
+  getCXXDestructorLinkage(GVALinkage Linkage, const CXXDestructorDecl *Dtor,
+                          CXXDtorType DT) const override;
+
+  void EmitCXXDestructors(const CXXDestructorDecl *D) override;
+
+  const CXXRecordDecl *
+  getThisArgumentTypeForMethod(const CXXMethodDecl *MD) override {
+    if (MD->isVirtual() && !isa<CXXDestructorDecl>(MD)) {
+      MethodVFTableLocation ML =
+          CGM.getMicrosoftVTableContext().getMethodVFTableLocation(MD);
+      // The vbases might be ordered differently in the final overrider object
+      // and the complete object, so the "this" argument may sometimes point to
+      // memory that has no particular type (e.g. past the complete object).
+      // In this case, we just use a generic pointer type.
+      // FIXME: might want to have a more precise type in the non-virtual
+      // multiple inheritance case.
+      if (ML.VBase || !ML.VFPtrOffset.isZero())
+        return nullptr;
+    }
+    return MD->getParent();
+  }
+
+  Address
+  adjustThisArgumentForVirtualFunctionCall(CodeGenFunction &CGF, GlobalDecl GD,
+                                           Address This,
+                                           bool VirtualCall) override;
+
+  void addImplicitStructorParams(CodeGenFunction &CGF, QualType &ResTy,
+                                 FunctionArgList &Params) override;
+
+  void EmitInstanceFunctionProlog(CodeGenFunction &CGF) override;
+
+  AddedStructorArgs
+  addImplicitConstructorArgs(CodeGenFunction &CGF, const CXXConstructorDecl *D,
+                             CXXCtorType Type, bool ForVirtualBase,
+                             bool Delegating, CallArgList &Args) override;
+
+  void EmitDestructorCall(CodeGenFunction &CGF, const CXXDestructorDecl *DD,
+                          CXXDtorType Type, bool ForVirtualBase,
+                          bool Delegating, Address This,
+                          QualType ThisTy) override;
+
+  void emitVTableTypeMetadata(const VPtrInfo &Info, const CXXRecordDecl *RD,
+                              llvm::GlobalVariable *VTable);
+
+  void emitVTableDefinitions(CodeGenVTables &CGVT,
+                             const CXXRecordDecl *RD) override;
+
+  bool isVirtualOffsetNeededForVTableField(CodeGenFunction &CGF,
+                                           CodeGenFunction::VPtr Vptr) override;
+
+  /// Don't initialize vptrs if dynamic class
+  /// is marked with with the 'novtable' attribute.
+  bool doStructorsInitializeVPtrs(const CXXRecordDecl *VTableClass) override {
+    return !VTableClass->hasAttr<MSNoVTableAttr>();
+  }
+
+  llvm::Constant *
+  getVTableAddressPoint(BaseSubobject Base,
+                        const CXXRecordDecl *VTableClass) override;
+
+  llvm::Value *getVTableAddressPointInStructor(
+      CodeGenFunction &CGF, const CXXRecordDecl *VTableClass,
+      BaseSubobject Base, const CXXRecordDecl *NearestVBase) override;
+
+  llvm::Constant *
+  getVTableAddressPointForConstExpr(BaseSubobject Base,
+                                    const CXXRecordDecl *VTableClass) override;
+
+  llvm::GlobalVariable *getAddrOfVTable(const CXXRecordDecl *RD,
+                                        CharUnits VPtrOffset) override;
+
+  CGCallee getVirtualFunctionPointer(CodeGenFunction &CGF, GlobalDecl GD,
+                                     Address This, llvm::Type *Ty,
+                                     SourceLocation Loc) override;
+
+  llvm::Value *EmitVirtualDestructorCall(CodeGenFunction &CGF,
+                                         const CXXDestructorDecl *Dtor,
+                                         CXXDtorType DtorType, Address This,
+                                         DeleteOrMemberCallExpr E) override;
+
+  void adjustCallArgsForDestructorThunk(CodeGenFunction &CGF, GlobalDecl GD,
+                                        CallArgList &CallArgs) override {
+    assert(GD.getDtorType() == Dtor_Deleting &&
+           "Only deleting destructor thunks are available in this ABI");
+    CallArgs.add(RValue::get(getStructorImplicitParamValue(CGF)),
+                 getContext().IntTy);
+  }
+
+  void emitVirtualInheritanceTables(const CXXRecordDecl *RD) override;
+
+  llvm::GlobalVariable *
+  getAddrOfVBTable(const VPtrInfo &VBT, const CXXRecordDecl *RD,
+                   llvm::GlobalVariable::LinkageTypes Linkage);
+
+  llvm::GlobalVariable *
+  getAddrOfVirtualDisplacementMap(const CXXRecordDecl *SrcRD,
+                                  const CXXRecordDecl *DstRD) {
+    SmallString<256> OutName;
+    llvm::raw_svector_ostream Out(OutName);
+    getMangleContext().mangleCXXVirtualDisplacementMap(SrcRD, DstRD, Out);
+    StringRef MangledName = OutName.str();
+
+    if (auto *VDispMap = CGM.getModule().getNamedGlobal(MangledName))
+      return VDispMap;
+
+    MicrosoftVTableContext &VTContext = CGM.getMicrosoftVTableContext();
+    unsigned NumEntries = 1 + SrcRD->getNumVBases();
+    SmallVector<llvm::Constant *, 4> Map(NumEntries,
+                                         llvm::UndefValue::get(CGM.IntTy));
+    Map[0] = llvm::ConstantInt::get(CGM.IntTy, 0);
+    bool AnyDifferent = false;
+    for (const auto &I : SrcRD->vbases()) {
+      const CXXRecordDecl *VBase = I.getType()->getAsCXXRecordDecl();
+      if (!DstRD->isVirtuallyDerivedFrom(VBase))
+        continue;
+
+      unsigned SrcVBIndex = VTContext.getVBTableIndex(SrcRD, VBase);
+      unsigned DstVBIndex = VTContext.getVBTableIndex(DstRD, VBase);
+      Map[SrcVBIndex] = llvm::ConstantInt::get(CGM.IntTy, DstVBIndex * 4);
+      AnyDifferent |= SrcVBIndex != DstVBIndex;
+    }
+    // This map would be useless, don't use it.
+    if (!AnyDifferent)
+      return nullptr;
+
+    llvm::ArrayType *VDispMapTy = llvm::ArrayType::get(CGM.IntTy, Map.size());
+    llvm::Constant *Init = llvm::ConstantArray::get(VDispMapTy, Map);
+    llvm::GlobalValue::LinkageTypes Linkage =
+        SrcRD->isExternallyVisible() && DstRD->isExternallyVisible()
+            ? llvm::GlobalValue::LinkOnceODRLinkage
+            : llvm::GlobalValue::InternalLinkage;
+    auto *VDispMap = new llvm::GlobalVariable(
+        CGM.getModule(), VDispMapTy, /*isConstant=*/true, Linkage,
+        /*Initializer=*/Init, MangledName);
+    return VDispMap;
+  }
+
+  void emitVBTableDefinition(const VPtrInfo &VBT, const CXXRecordDecl *RD,
+                             llvm::GlobalVariable *GV) const;
+
+  void setThunkLinkage(llvm::Function *Thunk, bool ForVTable,
+                       GlobalDecl GD, bool ReturnAdjustment) override {
+    GVALinkage Linkage =
+        getContext().GetGVALinkageForFunction(cast<FunctionDecl>(GD.getDecl()));
+
+    if (Linkage == GVA_Internal)
+      Thunk->setLinkage(llvm::GlobalValue::InternalLinkage);
+    else if (ReturnAdjustment)
+      Thunk->setLinkage(llvm::GlobalValue::WeakODRLinkage);
+    else
+      Thunk->setLinkage(llvm::GlobalValue::LinkOnceODRLinkage);
+  }
+
+  bool exportThunk() override { return false; }
+
+  llvm::Value *performThisAdjustment(CodeGenFunction &CGF, Address This,
+                                     const ThisAdjustment &TA) override;
+
+  llvm::Value *performReturnAdjustment(CodeGenFunction &CGF, Address Ret,
+                                       const ReturnAdjustment &RA) override;
+
+  void EmitThreadLocalInitFuncs(
+      CodeGenModule &CGM, ArrayRef<const VarDecl *> CXXThreadLocals,
+      ArrayRef<llvm::Function *> CXXThreadLocalInits,
+      ArrayRef<const VarDecl *> CXXThreadLocalInitVars) override;
+
+  bool usesThreadWrapperFunction(const VarDecl *VD) const override {
+    return false;
+  }
+  LValue EmitThreadLocalVarDeclLValue(CodeGenFunction &CGF, const VarDecl *VD,
+                                      QualType LValType) override;
+
+  void EmitGuardedInit(CodeGenFunction &CGF, const VarDecl &D,
+                       llvm::GlobalVariable *DeclPtr,
+                       bool PerformInit) override;
+  void registerGlobalDtor(CodeGenFunction &CGF, const VarDecl &D,
+                          llvm::FunctionCallee Dtor,
+                          llvm::Constant *Addr) override;
+
+  // ==== Notes on array cookies =========
+  //
+  // MSVC seems to only use cookies when the class has a destructor; a
+  // two-argument usual array deallocation function isn't sufficient.
+  //
+  // For example, this code prints "100" and "1":
+  //   struct A {
+  //     char x;
+  //     void *operator new[](size_t sz) {
+  //       printf("%u\n", sz);
+  //       return malloc(sz);
+  //     }
+  //     void operator delete[](void *p, size_t sz) {
+  //       printf("%u\n", sz);
+  //       free(p);
+  //     }
+  //   };
+  //   int main() {
+  //     A *p = new A[100];
+  //     delete[] p;
+  //   }
+  // Whereas it prints "104" and "104" if you give A a destructor.
+
+  bool requiresArrayCookie(const CXXDeleteExpr *expr,
+                           QualType elementType) override;
+  bool requiresArrayCookie(const CXXNewExpr *expr) override;
+  CharUnits getArrayCookieSizeImpl(QualType type) override;
+  Address InitializeArrayCookie(CodeGenFunction &CGF,
+                                Address NewPtr,
+                                llvm::Value *NumElements,
+                                const CXXNewExpr *expr,
+                                QualType ElementType) override;
+  llvm::Value *readArrayCookieImpl(CodeGenFunction &CGF,
+                                   Address allocPtr,
+                                   CharUnits cookieSize) override;
+
+  friend struct MSRTTIBuilder;
+
+  bool isImageRelative() const {
+    return CGM.getTarget().getPointerWidth(/*AddrSpace=*/0) == 64;
+  }
+
+  // 5 routines for constructing the llvm types for MS RTTI structs.
+  llvm::StructType *getTypeDescriptorType(StringRef TypeInfoString) {
+    llvm::SmallString<32> TDTypeName("rtti.TypeDescriptor");
+    TDTypeName += llvm::utostr(TypeInfoString.size());
+    llvm::StructType *&TypeDescriptorType =
+        TypeDescriptorTypeMap[TypeInfoString.size()];
+    if (TypeDescriptorType)
+      return TypeDescriptorType;
+    llvm::Type *FieldTypes[] = {
+        CGM.Int8PtrPtrTy,
+        CGM.Int8PtrTy,
+        llvm::ArrayType::get(CGM.Int8Ty, TypeInfoString.size() + 1)};
+    TypeDescriptorType =
+        llvm::StructType::create(CGM.getLLVMContext(), FieldTypes, TDTypeName);
+    return TypeDescriptorType;
+  }
+
+  llvm::Type *getImageRelativeType(llvm::Type *PtrType) {
+    if (!isImageRelative())
+      return PtrType;
+    return CGM.IntTy;
+  }
+
+  llvm::StructType *getBaseClassDescriptorType() {
+    if (BaseClassDescriptorType)
+      return BaseClassDescriptorType;
+    llvm::Type *FieldTypes[] = {
+        getImageRelativeType(CGM.Int8PtrTy),
+        CGM.IntTy,
+        CGM.IntTy,
+        CGM.IntTy,
+        CGM.IntTy,
+        CGM.IntTy,
+        getImageRelativeType(getClassHierarchyDescriptorType()->getPointerTo()),
+    };
+    BaseClassDescriptorType = llvm::StructType::create(
+        CGM.getLLVMContext(), FieldTypes, "rtti.BaseClassDescriptor");
+    return BaseClassDescriptorType;
+  }
+
+  llvm::StructType *getClassHierarchyDescriptorType() {
+    if (ClassHierarchyDescriptorType)
+      return ClassHierarchyDescriptorType;
+    // Forward-declare RTTIClassHierarchyDescriptor to break a cycle.
+    ClassHierarchyDescriptorType = llvm::StructType::create(
+        CGM.getLLVMContext(), "rtti.ClassHierarchyDescriptor");
+    llvm::Type *FieldTypes[] = {
+        CGM.IntTy,
+        CGM.IntTy,
+        CGM.IntTy,
+        getImageRelativeType(
+            getBaseClassDescriptorType()->getPointerTo()->getPointerTo()),
+    };
+    ClassHierarchyDescriptorType->setBody(FieldTypes);
+    return ClassHierarchyDescriptorType;
+  }
+
+  llvm::StructType *getCompleteObjectLocatorType() {
+    if (CompleteObjectLocatorType)
+      return CompleteObjectLocatorType;
+    CompleteObjectLocatorType = llvm::StructType::create(
+        CGM.getLLVMContext(), "rtti.CompleteObjectLocator");
+    llvm::Type *FieldTypes[] = {
+        CGM.IntTy,
+        CGM.IntTy,
+        CGM.IntTy,
+        getImageRelativeType(CGM.Int8PtrTy),
+        getImageRelativeType(getClassHierarchyDescriptorType()->getPointerTo()),
+        getImageRelativeType(CompleteObjectLocatorType),
+    };
+    llvm::ArrayRef<llvm::Type *> FieldTypesRef(FieldTypes);
+    if (!isImageRelative())
+      FieldTypesRef = FieldTypesRef.drop_back();
+    CompleteObjectLocatorType->setBody(FieldTypesRef);
+    return CompleteObjectLocatorType;
+  }
+
+  llvm::GlobalVariable *getImageBase() {
+    StringRef Name = "__ImageBase";
+    if (llvm::GlobalVariable *GV = CGM.getModule().getNamedGlobal(Name))
+      return GV;
+
+    auto *GV = new llvm::GlobalVariable(CGM.getModule(), CGM.Int8Ty,
+                                        /*isConstant=*/true,
+                                        llvm::GlobalValue::ExternalLinkage,
+                                        /*Initializer=*/nullptr, Name);
+    CGM.setDSOLocal(GV);
+    return GV;
+  }
+
+  llvm::Constant *getImageRelativeConstant(llvm::Constant *PtrVal) {
+    if (!isImageRelative())
+      return PtrVal;
+
+    if (PtrVal->isNullValue())
+      return llvm::Constant::getNullValue(CGM.IntTy);
+
+    llvm::Constant *ImageBaseAsInt =
+        llvm::ConstantExpr::getPtrToInt(getImageBase(), CGM.IntPtrTy);
+    llvm::Constant *PtrValAsInt =
+        llvm::ConstantExpr::getPtrToInt(PtrVal, CGM.IntPtrTy);
+    llvm::Constant *Diff =
+        llvm::ConstantExpr::getSub(PtrValAsInt, ImageBaseAsInt,
+                                   /*HasNUW=*/true, /*HasNSW=*/true);
+    return llvm::ConstantExpr::getTrunc(Diff, CGM.IntTy);
+  }
+
+private:
+  MicrosoftMangleContext &getMangleContext() {
+    return cast<MicrosoftMangleContext>(CodeGen::CGCXXABI::getMangleContext());
+  }
+
+  llvm::Constant *getZeroInt() {
+    return llvm::ConstantInt::get(CGM.IntTy, 0);
+  }
+
+  llvm::Constant *getAllOnesInt() {
+    return  llvm::Constant::getAllOnesValue(CGM.IntTy);
+  }
+
+  CharUnits getVirtualFunctionPrologueThisAdjustment(GlobalDecl GD) override;
+
+  void
+  GetNullMemberPointerFields(const MemberPointerType *MPT,
+                             llvm::SmallVectorImpl<llvm::Constant *> &fields);
+
+  /// Shared code for virtual base adjustment.  Returns the offset from
+  /// the vbptr to the virtual base.  Optionally returns the address of the
+  /// vbptr itself.
+  llvm::Value *GetVBaseOffsetFromVBPtr(CodeGenFunction &CGF,
+                                       Address Base,
+                                       llvm::Value *VBPtrOffset,
+                                       llvm::Value *VBTableOffset,
+                                       llvm::Value **VBPtr = nullptr);
+
+  llvm::Value *GetVBaseOffsetFromVBPtr(CodeGenFunction &CGF,
+                                       Address Base,
+                                       int32_t VBPtrOffset,
+                                       int32_t VBTableOffset,
+                                       llvm::Value **VBPtr = nullptr) {
+    assert(VBTableOffset % 4 == 0 && "should be byte offset into table of i32s");
+    llvm::Value *VBPOffset = llvm::ConstantInt::get(CGM.IntTy, VBPtrOffset),
+                *VBTOffset = llvm::ConstantInt::get(CGM.IntTy, VBTableOffset);
+    return GetVBaseOffsetFromVBPtr(CGF, Base, VBPOffset, VBTOffset, VBPtr);
+  }
+
+  std::tuple<Address, llvm::Value *, const CXXRecordDecl *>
+  performBaseAdjustment(CodeGenFunction &CGF, Address Value,
+                        QualType SrcRecordTy);
+
+  /// Performs a full virtual base adjustment.  Used to dereference
+  /// pointers to members of virtual bases.
+  llvm::Value *AdjustVirtualBase(CodeGenFunction &CGF, const Expr *E,
+                                 const CXXRecordDecl *RD, Address Base,
+                                 llvm::Value *VirtualBaseAdjustmentOffset,
+                                 llvm::Value *VBPtrOffset /* optional */);
+
+  /// Emits a full member pointer with the fields common to data and
+  /// function member pointers.
+  llvm::Constant *EmitFullMemberPointer(llvm::Constant *FirstField,
+                                        bool IsMemberFunction,
+                                        const CXXRecordDecl *RD,
+                                        CharUnits NonVirtualBaseAdjustment,
+                                        unsigned VBTableIndex);
+
+  bool MemberPointerConstantIsNull(const MemberPointerType *MPT,
+                                   llvm::Constant *MP);
+
+  /// - Initialize all vbptrs of 'this' with RD as the complete type.
+  void EmitVBPtrStores(CodeGenFunction &CGF, const CXXRecordDecl *RD);
+
+  /// Caching wrapper around VBTableBuilder::enumerateVBTables().
+  const VBTableGlobals &enumerateVBTables(const CXXRecordDecl *RD);
+
+  /// Generate a thunk for calling a virtual member function MD.
+  llvm::Function *EmitVirtualMemPtrThunk(const CXXMethodDecl *MD,
+                                         const MethodVFTableLocation &ML);
+
+  llvm::Constant *EmitMemberDataPointer(const CXXRecordDecl *RD,
+                                        CharUnits offset);
+
+public:
+  llvm::Type *ConvertMemberPointerType(const MemberPointerType *MPT) override;
+
+  bool isZeroInitializable(const MemberPointerType *MPT) override;
+
+  bool isMemberPointerConvertible(const MemberPointerType *MPT) const override {
+    const CXXRecordDecl *RD = MPT->getMostRecentCXXRecordDecl();
+    return RD->hasAttr<MSInheritanceAttr>();
+  }
+
+  llvm::Constant *EmitNullMemberPointer(const MemberPointerType *MPT) override;
+
+  llvm::Constant *EmitMemberDataPointer(const MemberPointerType *MPT,
+                                        CharUnits offset) override;
+  llvm::Constant *EmitMemberFunctionPointer(const CXXMethodDecl *MD) override;
+  llvm::Constant *EmitMemberPointer(const APValue &MP, QualType MPT) override;
+
+  llvm::Value *EmitMemberPointerComparison(CodeGenFunction &CGF,
+                                           llvm::Value *L,
+                                           llvm::Value *R,
+                                           const MemberPointerType *MPT,
+                                           bool Inequality) override;
+
+  llvm::Value *EmitMemberPointerIsNotNull(CodeGenFunction &CGF,
+                                          llvm::Value *MemPtr,
+                                          const MemberPointerType *MPT) override;
+
+  llvm::Value *
+  EmitMemberDataPointerAddress(CodeGenFunction &CGF, const Expr *E,
+                               Address Base, llvm::Value *MemPtr,
+                               const MemberPointerType *MPT) override;
+
+  llvm::Value *EmitNonNullMemberPointerConversion(
+      const MemberPointerType *SrcTy, const MemberPointerType *DstTy,
+      CastKind CK, CastExpr::path_const_iterator PathBegin,
+      CastExpr::path_const_iterator PathEnd, llvm::Value *Src,
+      CGBuilderTy &Builder);
+
+  llvm::Value *EmitMemberPointerConversion(CodeGenFunction &CGF,
+                                           const CastExpr *E,
+                                           llvm::Value *Src) override;
+
+  llvm::Constant *EmitMemberPointerConversion(const CastExpr *E,
+                                              llvm::Constant *Src) override;
+
+  llvm::Constant *EmitMemberPointerConversion(
+      const MemberPointerType *SrcTy, const MemberPointerType *DstTy,
+      CastKind CK, CastExpr::path_const_iterator PathBegin,
+      CastExpr::path_const_iterator PathEnd, llvm::Constant *Src);
+
+  CGCallee
+  EmitLoadOfMemberFunctionPointer(CodeGenFunction &CGF, const Expr *E,
+                                  Address This, llvm::Value *&ThisPtrForCall,
+                                  llvm::Value *MemPtr,
+                                  const MemberPointerType *MPT) override;
+
+  void emitCXXStructor(GlobalDecl GD) override;
+
+  llvm::StructType *getCatchableTypeType() {
+    if (CatchableTypeType)
+      return CatchableTypeType;
+    llvm::Type *FieldTypes[] = {
+        CGM.IntTy,                           // Flags
+        getImageRelativeType(CGM.Int8PtrTy), // TypeDescriptor
+        CGM.IntTy,                           // NonVirtualAdjustment
+        CGM.IntTy,                           // OffsetToVBPtr
+        CGM.IntTy,                           // VBTableIndex
+        CGM.IntTy,                           // Size
+        getImageRelativeType(CGM.Int8PtrTy)  // CopyCtor
+    };
+    CatchableTypeType = llvm::StructType::create(
+        CGM.getLLVMContext(), FieldTypes, "eh.CatchableType");
+    return CatchableTypeType;
+  }
+
+  llvm::StructType *getCatchableTypeArrayType(uint32_t NumEntries) {
+    llvm::StructType *&CatchableTypeArrayType =
+        CatchableTypeArrayTypeMap[NumEntries];
+    if (CatchableTypeArrayType)
+      return CatchableTypeArrayType;
+
+    llvm::SmallString<23> CTATypeName("eh.CatchableTypeArray.");
+    CTATypeName += llvm::utostr(NumEntries);
+    llvm::Type *CTType =
+        getImageRelativeType(getCatchableTypeType()->getPointerTo());
+    llvm::Type *FieldTypes[] = {
+        CGM.IntTy,                               // NumEntries
+        llvm::ArrayType::get(CTType, NumEntries) // CatchableTypes
+    };
+    CatchableTypeArrayType =
+        llvm::StructType::create(CGM.getLLVMContext(), FieldTypes, CTATypeName);
+    return CatchableTypeArrayType;
+  }
+
+  llvm::StructType *getThrowInfoType() {
+    if (ThrowInfoType)
+      return ThrowInfoType;
+    llvm::Type *FieldTypes[] = {
+        CGM.IntTy,                           // Flags
+        getImageRelativeType(CGM.Int8PtrTy), // CleanupFn
+        getImageRelativeType(CGM.Int8PtrTy), // ForwardCompat
+        getImageRelativeType(CGM.Int8PtrTy)  // CatchableTypeArray
+    };
+    ThrowInfoType = llvm::StructType::create(CGM.getLLVMContext(), FieldTypes,
+                                             "eh.ThrowInfo");
+    return ThrowInfoType;
+  }
+
+  llvm::FunctionCallee getThrowFn() {
+    // _CxxThrowException is passed an exception object and a ThrowInfo object
+    // which describes the exception.
+    llvm::Type *Args[] = {CGM.Int8PtrTy, getThrowInfoType()->getPointerTo()};
+    llvm::FunctionType *FTy =
+        llvm::FunctionType::get(CGM.VoidTy, Args, /*isVarArg=*/false);
+    llvm::FunctionCallee Throw =
+        CGM.CreateRuntimeFunction(FTy, "_CxxThrowException");
+    // _CxxThrowException is stdcall on 32-bit x86 platforms.
+    if (CGM.getTarget().getTriple().getArch() == llvm::Triple::x86) {
+      if (auto *Fn = dyn_cast<llvm::Function>(Throw.getCallee()))
+        Fn->setCallingConv(llvm::CallingConv::X86_StdCall);
+    }
+    return Throw;
+  }
+
+  llvm::Function *getAddrOfCXXCtorClosure(const CXXConstructorDecl *CD,
+                                          CXXCtorType CT);
+
+  llvm::Constant *getCatchableType(QualType T,
+                                   uint32_t NVOffset = 0,
+                                   int32_t VBPtrOffset = -1,
+                                   uint32_t VBIndex = 0);
+
+  llvm::GlobalVariable *getCatchableTypeArray(QualType T);
+
+  llvm::GlobalVariable *getThrowInfo(QualType T) override;
+
+  std::pair<llvm::Value *, const CXXRecordDecl *>
+  LoadVTablePtr(CodeGenFunction &CGF, Address This,
+                const CXXRecordDecl *RD) override;
+
+private:
+  typedef std::pair<const CXXRecordDecl *, CharUnits> VFTableIdTy;
+  typedef llvm::DenseMap<VFTableIdTy, llvm::GlobalVariable *> VTablesMapTy;
+  typedef llvm::DenseMap<VFTableIdTy, llvm::GlobalValue *> VFTablesMapTy;
+  /// All the vftables that have been referenced.
+  VFTablesMapTy VFTablesMap;
+  VTablesMapTy VTablesMap;
+
+  /// This set holds the record decls we've deferred vtable emission for.
+  llvm::SmallPtrSet<const CXXRecordDecl *, 4> DeferredVFTables;
+
+
+  /// All the vbtables which have been referenced.
+  llvm::DenseMap<const CXXRecordDecl *, VBTableGlobals> VBTablesMap;
+
+  /// Info on the global variable used to guard initialization of static locals.
+  /// The BitIndex field is only used for externally invisible declarations.
+  struct GuardInfo {
+    GuardInfo() : Guard(nullptr), BitIndex(0) {}
+    llvm::GlobalVariable *Guard;
+    unsigned BitIndex;
+  };
+
+  /// Map from DeclContext to the current guard variable.  We assume that the
+  /// AST is visited in source code order.
+  llvm::DenseMap<const DeclContext *, GuardInfo> GuardVariableMap;
+  llvm::DenseMap<const DeclContext *, GuardInfo> ThreadLocalGuardVariableMap;
+  llvm::DenseMap<const DeclContext *, unsigned> ThreadSafeGuardNumMap;
+
+  llvm::DenseMap<size_t, llvm::StructType *> TypeDescriptorTypeMap;
+  llvm::StructType *BaseClassDescriptorType;
+  llvm::StructType *ClassHierarchyDescriptorType;
+  llvm::StructType *CompleteObjectLocatorType;
+
+  llvm::DenseMap<QualType, llvm::GlobalVariable *> CatchableTypeArrays;
+
+  llvm::StructType *CatchableTypeType;
+  llvm::DenseMap<uint32_t, llvm::StructType *> CatchableTypeArrayTypeMap;
+  llvm::StructType *ThrowInfoType;
+};
+
+}
+
+CGCXXABI::RecordArgABI
+MicrosoftCXXABI::getRecordArgABI(const CXXRecordDecl *RD) const {
+  switch (CGM.getTarget().getTriple().getArch()) {
+  default:
+    // FIXME: Implement for other architectures.
+    return RAA_Default;
+
+  case llvm::Triple::thumb:
+    // Use the simple Itanium rules for now.
+    // FIXME: This is incompatible with MSVC for arguments with a dtor and no
+    // copy ctor.
+    return !RD->canPassInRegisters() ? RAA_Indirect : RAA_Default;
+
+  case llvm::Triple::x86:
+    // All record arguments are passed in memory on x86.  Decide whether to
+    // construct the object directly in argument memory, or to construct the
+    // argument elsewhere and copy the bytes during the call.
+
+    // If C++ prohibits us from making a copy, construct the arguments directly
+    // into argument memory.
+    if (!RD->canPassInRegisters())
+      return RAA_DirectInMemory;
+
+    // Otherwise, construct the argument into a temporary and copy the bytes
+    // into the outgoing argument memory.
+    return RAA_Default;
+
+  case llvm::Triple::x86_64:
+  case llvm::Triple::aarch64:
+    return !RD->canPassInRegisters() ? RAA_Indirect : RAA_Default;
+  }
+
+  llvm_unreachable("invalid enum");
+}
+
+void MicrosoftCXXABI::emitVirtualObjectDelete(CodeGenFunction &CGF,
+                                              const CXXDeleteExpr *DE,
+                                              Address Ptr,
+                                              QualType ElementType,
+                                              const CXXDestructorDecl *Dtor) {
+  // FIXME: Provide a source location here even though there's no
+  // CXXMemberCallExpr for dtor call.
+  bool UseGlobalDelete = DE->isGlobalDelete();
+  CXXDtorType DtorType = UseGlobalDelete ? Dtor_Complete : Dtor_Deleting;
+  llvm::Value *MDThis = EmitVirtualDestructorCall(CGF, Dtor, DtorType, Ptr, DE);
+  if (UseGlobalDelete)
+    CGF.EmitDeleteCall(DE->getOperatorDelete(), MDThis, ElementType);
+}
+
+void MicrosoftCXXABI::emitRethrow(CodeGenFunction &CGF, bool isNoReturn) {
+  llvm::Value *Args[] = {
+      llvm::ConstantPointerNull::get(CGM.Int8PtrTy),
+      llvm::ConstantPointerNull::get(getThrowInfoType()->getPointerTo())};
+  llvm::FunctionCallee Fn = getThrowFn();
+  if (isNoReturn)
+    CGF.EmitNoreturnRuntimeCallOrInvoke(Fn, Args);
+  else
+    CGF.EmitRuntimeCallOrInvoke(Fn, Args);
+}
+
+void MicrosoftCXXABI::emitBeginCatch(CodeGenFunction &CGF,
+                                     const CXXCatchStmt *S) {
+  // In the MS ABI, the runtime handles the copy, and the catch handler is
+  // responsible for destruction.
+  VarDecl *CatchParam = S->getExceptionDecl();
+  llvm::BasicBlock *CatchPadBB = CGF.Builder.GetInsertBlock();
+  llvm::CatchPadInst *CPI =
+      cast<llvm::CatchPadInst>(CatchPadBB->getFirstNonPHI());
+  CGF.CurrentFuncletPad = CPI;
+
+  // If this is a catch-all or the catch parameter is unnamed, we don't need to
+  // emit an alloca to the object.
+  if (!CatchParam || !CatchParam->getDeclName()) {
+    CGF.EHStack.pushCleanup<CatchRetScope>(NormalCleanup, CPI);
+    return;
+  }
+
+  CodeGenFunction::AutoVarEmission var = CGF.EmitAutoVarAlloca(*CatchParam);
+  CPI->setArgOperand(2, var.getObjectAddress(CGF).getPointer());
+  CGF.EHStack.pushCleanup<CatchRetScope>(NormalCleanup, CPI);
+  CGF.EmitAutoVarCleanups(var);
+}
+
+/// We need to perform a generic polymorphic operation (like a typeid
+/// or a cast), which requires an object with a vfptr.  Adjust the
+/// address to point to an object with a vfptr.
+std::tuple<Address, llvm::Value *, const CXXRecordDecl *>
+MicrosoftCXXABI::performBaseAdjustment(CodeGenFunction &CGF, Address Value,
+                                       QualType SrcRecordTy) {
+  Value = CGF.Builder.CreateBitCast(Value, CGF.Int8PtrTy);
+  const CXXRecordDecl *SrcDecl = SrcRecordTy->getAsCXXRecordDecl();
+  const ASTContext &Context = getContext();
+
+  // If the class itself has a vfptr, great.  This check implicitly
+  // covers non-virtual base subobjects: a class with its own virtual
+  // functions would be a candidate to be a primary base.
+  if (Context.getASTRecordLayout(SrcDecl).hasExtendableVFPtr())
+    return std::make_tuple(Value, llvm::ConstantInt::get(CGF.Int32Ty, 0),
+                           SrcDecl);
+
+  // Okay, one of the vbases must have a vfptr, or else this isn't
+  // actually a polymorphic class.
+  const CXXRecordDecl *PolymorphicBase = nullptr;
+  for (auto &Base : SrcDecl->vbases()) {
+    const CXXRecordDecl *BaseDecl = Base.getType()->getAsCXXRecordDecl();
+    if (Context.getASTRecordLayout(BaseDecl).hasExtendableVFPtr()) {
+      PolymorphicBase = BaseDecl;
+      break;
+    }
+  }
+  assert(PolymorphicBase && "polymorphic class has no apparent vfptr?");
+
+  llvm::Value *Offset =
+    GetVirtualBaseClassOffset(CGF, Value, SrcDecl, PolymorphicBase);
+  llvm::Value *Ptr = CGF.Builder.CreateInBoundsGEP(Value.getPointer(), Offset);
+  CharUnits VBaseAlign =
+    CGF.CGM.getVBaseAlignment(Value.getAlignment(), SrcDecl, PolymorphicBase);
+  return std::make_tuple(Address(Ptr, VBaseAlign), Offset, PolymorphicBase);
+}
+
+bool MicrosoftCXXABI::shouldTypeidBeNullChecked(bool IsDeref,
+                                                QualType SrcRecordTy) {
+  const CXXRecordDecl *SrcDecl = SrcRecordTy->getAsCXXRecordDecl();
+  return IsDeref &&
+         !getContext().getASTRecordLayout(SrcDecl).hasExtendableVFPtr();
+}
+
+static llvm::CallBase *emitRTtypeidCall(CodeGenFunction &CGF,
+                                        llvm::Value *Argument) {
+  llvm::Type *ArgTypes[] = {CGF.Int8PtrTy};
+  llvm::FunctionType *FTy =
+      llvm::FunctionType::get(CGF.Int8PtrTy, ArgTypes, false);
+  llvm::Value *Args[] = {Argument};
+  llvm::FunctionCallee Fn = CGF.CGM.CreateRuntimeFunction(FTy, "__RTtypeid");
+  return CGF.EmitRuntimeCallOrInvoke(Fn, Args);
+}
+
+void MicrosoftCXXABI::EmitBadTypeidCall(CodeGenFunction &CGF) {
+  llvm::CallBase *Call =
+      emitRTtypeidCall(CGF, llvm::Constant::getNullValue(CGM.VoidPtrTy));
+  Call->setDoesNotReturn();
+  CGF.Builder.CreateUnreachable();
+}
+
+llvm::Value *MicrosoftCXXABI::EmitTypeid(CodeGenFunction &CGF,
+                                         QualType SrcRecordTy,
+                                         Address ThisPtr,
+                                         llvm::Type *StdTypeInfoPtrTy) {
+  std::tie(ThisPtr, std::ignore, std::ignore) =
+      performBaseAdjustment(CGF, ThisPtr, SrcRecordTy);
+  llvm::CallBase *Typeid = emitRTtypeidCall(CGF, ThisPtr.getPointer());
+  return CGF.Builder.CreateBitCast(Typeid, StdTypeInfoPtrTy);
+}
+
+bool MicrosoftCXXABI::shouldDynamicCastCallBeNullChecked(bool SrcIsPtr,
+                                                         QualType SrcRecordTy) {
+  const CXXRecordDecl *SrcDecl = SrcRecordTy->getAsCXXRecordDecl();
+  return SrcIsPtr &&
+         !getContext().getASTRecordLayout(SrcDecl).hasExtendableVFPtr();
+}
+
+llvm::Value *MicrosoftCXXABI::EmitDynamicCastCall(
+    CodeGenFunction &CGF, Address This, QualType SrcRecordTy,
+    QualType DestTy, QualType DestRecordTy, llvm::BasicBlock *CastEnd) {
+  llvm::Type *DestLTy = CGF.ConvertType(DestTy);
+
+  llvm::Value *SrcRTTI =
+      CGF.CGM.GetAddrOfRTTIDescriptor(SrcRecordTy.getUnqualifiedType());
+  llvm::Value *DestRTTI =
+      CGF.CGM.GetAddrOfRTTIDescriptor(DestRecordTy.getUnqualifiedType());
+
+  llvm::Value *Offset;
+  std::tie(This, Offset, std::ignore) =
+      performBaseAdjustment(CGF, This, SrcRecordTy);
+  llvm::Value *ThisPtr = This.getPointer();
+  Offset = CGF.Builder.CreateTrunc(Offset, CGF.Int32Ty);
+
+  // PVOID __RTDynamicCast(
+  //   PVOID inptr,
+  //   LONG VfDelta,
+  //   PVOID SrcType,
+  //   PVOID TargetType,
+  //   BOOL isReference)
+  llvm::Type *ArgTypes[] = {CGF.Int8PtrTy, CGF.Int32Ty, CGF.Int8PtrTy,
+                            CGF.Int8PtrTy, CGF.Int32Ty};
+  llvm::FunctionCallee Function = CGF.CGM.CreateRuntimeFunction(
+      llvm::FunctionType::get(CGF.Int8PtrTy, ArgTypes, false),
+      "__RTDynamicCast");
+  llvm::Value *Args[] = {
+      ThisPtr, Offset, SrcRTTI, DestRTTI,
+      llvm::ConstantInt::get(CGF.Int32Ty, DestTy->isReferenceType())};
+  ThisPtr = CGF.EmitRuntimeCallOrInvoke(Function, Args);
+  return CGF.Builder.CreateBitCast(ThisPtr, DestLTy);
+}
+
+llvm::Value *
+MicrosoftCXXABI::EmitDynamicCastToVoid(CodeGenFunction &CGF, Address Value,
+                                       QualType SrcRecordTy,
+                                       QualType DestTy) {
+  std::tie(Value, std::ignore, std::ignore) =
+      performBaseAdjustment(CGF, Value, SrcRecordTy);
+
+  // PVOID __RTCastToVoid(
+  //   PVOID inptr)
+  llvm::Type *ArgTypes[] = {CGF.Int8PtrTy};
+  llvm::FunctionCallee Function = CGF.CGM.CreateRuntimeFunction(
+      llvm::FunctionType::get(CGF.Int8PtrTy, ArgTypes, false),
+      "__RTCastToVoid");
+  llvm::Value *Args[] = {Value.getPointer()};
+  return CGF.EmitRuntimeCall(Function, Args);
+}
+
+bool MicrosoftCXXABI::EmitBadCastCall(CodeGenFunction &CGF) {
+  return false;
+}
+
+llvm::Value *MicrosoftCXXABI::GetVirtualBaseClassOffset(
+    CodeGenFunction &CGF, Address This, const CXXRecordDecl *ClassDecl,
+    const CXXRecordDecl *BaseClassDecl) {
+  const ASTContext &Context = getContext();
+  int64_t VBPtrChars =
+      Context.getASTRecordLayout(ClassDecl).getVBPtrOffset().getQuantity();
+  llvm::Value *VBPtrOffset = llvm::ConstantInt::get(CGM.PtrDiffTy, VBPtrChars);
+  CharUnits IntSize = Context.getTypeSizeInChars(Context.IntTy);
+  CharUnits VBTableChars =
+      IntSize *
+      CGM.getMicrosoftVTableContext().getVBTableIndex(ClassDecl, BaseClassDecl);
+  llvm::Value *VBTableOffset =
+      llvm::ConstantInt::get(CGM.IntTy, VBTableChars.getQuantity());
+
+  llvm::Value *VBPtrToNewBase =
+      GetVBaseOffsetFromVBPtr(CGF, This, VBPtrOffset, VBTableOffset);
+  VBPtrToNewBase =
+      CGF.Builder.CreateSExtOrBitCast(VBPtrToNewBase, CGM.PtrDiffTy);
+  return CGF.Builder.CreateNSWAdd(VBPtrOffset, VBPtrToNewBase);
+}
+
+bool MicrosoftCXXABI::HasThisReturn(GlobalDecl GD) const {
+  return isa<CXXConstructorDecl>(GD.getDecl());
+}
+
+static bool isDeletingDtor(GlobalDecl GD) {
+  return isa<CXXDestructorDecl>(GD.getDecl()) &&
+         GD.getDtorType() == Dtor_Deleting;
+}
+
+bool MicrosoftCXXABI::hasMostDerivedReturn(GlobalDecl GD) const {
+  return isDeletingDtor(GD);
+}
+
+static bool IsSizeGreaterThan128(const CXXRecordDecl *RD) {
+  return RD->getASTContext().getTypeSize(RD->getTypeForDecl()) > 128;
+}
+
+static bool hasMicrosoftABIRestrictions(const CXXRecordDecl *RD) {
+  // For AArch64, we use the C++14 definition of an aggregate, so we also
+  // check for:
+  //   No private or protected non static data members.
+  //   No base classes
+  //   No virtual functions
+  // Additionally, we need to ensure that there is a trivial copy assignment
+  // operator, a trivial destructor and no user-provided constructors.
+  if (RD->hasProtectedFields() || RD->hasPrivateFields())
+    return true;
+  if (RD->getNumBases() > 0)
+    return true;
+  if (RD->isPolymorphic())
+    return true;
+  if (RD->hasNonTrivialCopyAssignment())
+    return true;
+  for (const CXXConstructorDecl *Ctor : RD->ctors())
+    if (Ctor->isUserProvided())
+      return true;
+  if (RD->hasNonTrivialDestructor())
+    return true;
+  return false;
+}
+
+bool MicrosoftCXXABI::classifyReturnType(CGFunctionInfo &FI) const {
+  const CXXRecordDecl *RD = FI.getReturnType()->getAsCXXRecordDecl();
+  if (!RD)
+    return false;
+
+  bool isAArch64 = CGM.getTarget().getTriple().isAArch64();
+  bool isSimple = !isAArch64 || !hasMicrosoftABIRestrictions(RD);
+  bool isIndirectReturn =
+      isAArch64 ? (!RD->canPassInRegisters() ||
+                   IsSizeGreaterThan128(RD))
+                : !RD->isPOD();
+  bool isInstanceMethod = FI.isInstanceMethod();
+
+  if (isIndirectReturn || !isSimple || isInstanceMethod) {
+    CharUnits Align = CGM.getContext().getTypeAlignInChars(FI.getReturnType());
+    FI.getReturnInfo() = ABIArgInfo::getIndirect(Align, /*ByVal=*/false);
+    FI.getReturnInfo().setSRetAfterThis(isInstanceMethod);
+
+    FI.getReturnInfo().setInReg(isAArch64 &&
+                                !(isSimple && IsSizeGreaterThan128(RD)));
+
+    return true;
+  }
+
+  // Otherwise, use the C ABI rules.
+  return false;
+}
+
+llvm::BasicBlock *
+MicrosoftCXXABI::EmitCtorCompleteObjectHandler(CodeGenFunction &CGF,
+                                               const CXXRecordDecl *RD) {
+  llvm::Value *IsMostDerivedClass = getStructorImplicitParamValue(CGF);
+  assert(IsMostDerivedClass &&
+         "ctor for a class with virtual bases must have an implicit parameter");
+  llvm::Value *IsCompleteObject =
+    CGF.Builder.CreateIsNotNull(IsMostDerivedClass, "is_complete_object");
+
+  llvm::BasicBlock *CallVbaseCtorsBB = CGF.createBasicBlock("ctor.init_vbases");
+  llvm::BasicBlock *SkipVbaseCtorsBB = CGF.createBasicBlock("ctor.skip_vbases");
+  CGF.Builder.CreateCondBr(IsCompleteObject,
+                           CallVbaseCtorsBB, SkipVbaseCtorsBB);
+
+  CGF.EmitBlock(CallVbaseCtorsBB);
+
+  // Fill in the vbtable pointers here.
+  EmitVBPtrStores(CGF, RD);
+
+  // CGF will put the base ctor calls in this basic block for us later.
+
+  return SkipVbaseCtorsBB;
+}
+
+llvm::BasicBlock *
+MicrosoftCXXABI::EmitDtorCompleteObjectHandler(CodeGenFunction &CGF) {
+  llvm::Value *IsMostDerivedClass = getStructorImplicitParamValue(CGF);
+  assert(IsMostDerivedClass &&
+         "ctor for a class with virtual bases must have an implicit parameter");
+  llvm::Value *IsCompleteObject =
+      CGF.Builder.CreateIsNotNull(IsMostDerivedClass, "is_complete_object");
+
+  llvm::BasicBlock *CallVbaseDtorsBB = CGF.createBasicBlock("Dtor.dtor_vbases");
+  llvm::BasicBlock *SkipVbaseDtorsBB = CGF.createBasicBlock("Dtor.skip_vbases");
+  CGF.Builder.CreateCondBr(IsCompleteObject,
+                           CallVbaseDtorsBB, SkipVbaseDtorsBB);
+
+  CGF.EmitBlock(CallVbaseDtorsBB);
+  // CGF will put the base dtor calls in this basic block for us later.
+
+  return SkipVbaseDtorsBB;
+}
+
+void MicrosoftCXXABI::initializeHiddenVirtualInheritanceMembers(
+    CodeGenFunction &CGF, const CXXRecordDecl *RD) {
+  // In most cases, an override for a vbase virtual method can adjust
+  // the "this" parameter by applying a constant offset.
+  // However, this is not enough while a constructor or a destructor of some
+  // class X is being executed if all the following conditions are met:
+  //  - X has virtual bases, (1)
+  //  - X overrides a virtual method M of a vbase Y, (2)
+  //  - X itself is a vbase of the most derived class.
+  //
+  // If (1) and (2) are true, the vtorDisp for vbase Y is a hidden member of X
+  // which holds the extra amount of "this" adjustment we must do when we use
+  // the X vftables (i.e. during X ctor or dtor).
+  // Outside the ctors and dtors, the values of vtorDisps are zero.
+
+  const ASTRecordLayout &Layout = getContext().getASTRecordLayout(RD);
+  typedef ASTRecordLayout::VBaseOffsetsMapTy VBOffsets;
+  const VBOffsets &VBaseMap = Layout.getVBaseOffsetsMap();
+  CGBuilderTy &Builder = CGF.Builder;
+
+  unsigned AS = getThisAddress(CGF).getAddressSpace();
+  llvm::Value *Int8This = nullptr;  // Initialize lazily.
+
+  for (const CXXBaseSpecifier &S : RD->vbases()) {
+    const CXXRecordDecl *VBase = S.getType()->getAsCXXRecordDecl();
+    auto I = VBaseMap.find(VBase);
+    assert(I != VBaseMap.end());
+    if (!I->second.hasVtorDisp())
+      continue;
+
+    llvm::Value *VBaseOffset =
+        GetVirtualBaseClassOffset(CGF, getThisAddress(CGF), RD, VBase);
+    uint64_t ConstantVBaseOffset = I->second.VBaseOffset.getQuantity();
+
+    // vtorDisp_for_vbase = vbptr[vbase_idx] - offsetof(RD, vbase).
+    llvm::Value *VtorDispValue = Builder.CreateSub(
+        VBaseOffset, llvm::ConstantInt::get(CGM.PtrDiffTy, ConstantVBaseOffset),
+        "vtordisp.value");
+    VtorDispValue = Builder.CreateTruncOrBitCast(VtorDispValue, CGF.Int32Ty);
+
+    if (!Int8This)
+      Int8This = Builder.CreateBitCast(getThisValue(CGF),
+                                       CGF.Int8Ty->getPointerTo(AS));
+    llvm::Value *VtorDispPtr = Builder.CreateInBoundsGEP(Int8This, VBaseOffset);
+    // vtorDisp is always the 32-bits before the vbase in the class layout.
+    VtorDispPtr = Builder.CreateConstGEP1_32(VtorDispPtr, -4);
+    VtorDispPtr = Builder.CreateBitCast(
+        VtorDispPtr, CGF.Int32Ty->getPointerTo(AS), "vtordisp.ptr");
+
+    Builder.CreateAlignedStore(VtorDispValue, VtorDispPtr,
+                               CharUnits::fromQuantity(4));
+  }
+}
+
+static bool hasDefaultCXXMethodCC(ASTContext &Context,
+                                  const CXXMethodDecl *MD) {
+  CallingConv ExpectedCallingConv = Context.getDefaultCallingConvention(
+      /*IsVariadic=*/false, /*IsCXXMethod=*/true);
+  CallingConv ActualCallingConv =
+      MD->getType()->castAs<FunctionProtoType>()->getCallConv();
+  return ExpectedCallingConv == ActualCallingConv;
+}
+
+void MicrosoftCXXABI::EmitCXXConstructors(const CXXConstructorDecl *D) {
+  // There's only one constructor type in this ABI.
+  CGM.EmitGlobal(GlobalDecl(D, Ctor_Complete));
+
+  // Exported default constructors either have a simple call-site where they use
+  // the typical calling convention and have a single 'this' pointer for an
+  // argument -or- they get a wrapper function which appropriately thunks to the
+  // real default constructor.  This thunk is the default constructor closure.
+  if (D->hasAttr<DLLExportAttr>() && D->isDefaultConstructor())
+    if (!hasDefaultCXXMethodCC(getContext(), D) || D->getNumParams() != 0) {
+      llvm::Function *Fn = getAddrOfCXXCtorClosure(D, Ctor_DefaultClosure);
+      Fn->setLinkage(llvm::GlobalValue::WeakODRLinkage);
+      CGM.setGVProperties(Fn, D);
+    }
+}
+
+void MicrosoftCXXABI::EmitVBPtrStores(CodeGenFunction &CGF,
+                                      const CXXRecordDecl *RD) {
+  Address This = getThisAddress(CGF);
+  This = CGF.Builder.CreateElementBitCast(This, CGM.Int8Ty, "this.int8");
+  const ASTContext &Context = getContext();
+  const ASTRecordLayout &Layout = Context.getASTRecordLayout(RD);
+
+  const VBTableGlobals &VBGlobals = enumerateVBTables(RD);
+  for (unsigned I = 0, E = VBGlobals.VBTables->size(); I != E; ++I) {
+    const std::unique_ptr<VPtrInfo> &VBT = (*VBGlobals.VBTables)[I];
+    llvm::GlobalVariable *GV = VBGlobals.Globals[I];
+    const ASTRecordLayout &SubobjectLayout =
+        Context.getASTRecordLayout(VBT->IntroducingObject);
+    CharUnits Offs = VBT->NonVirtualOffset;
+    Offs += SubobjectLayout.getVBPtrOffset();
+    if (VBT->getVBaseWithVPtr())
+      Offs += Layout.getVBaseClassOffset(VBT->getVBaseWithVPtr());
+    Address VBPtr = CGF.Builder.CreateConstInBoundsByteGEP(This, Offs);
+    llvm::Value *GVPtr =
+        CGF.Builder.CreateConstInBoundsGEP2_32(GV->getValueType(), GV, 0, 0);
+    VBPtr = CGF.Builder.CreateElementBitCast(VBPtr, GVPtr->getType(),
+                                      "vbptr." + VBT->ObjectWithVPtr->getName());
+    CGF.Builder.CreateStore(GVPtr, VBPtr);
+  }
+}
+
+CGCXXABI::AddedStructorArgs
+MicrosoftCXXABI::buildStructorSignature(GlobalDecl GD,
+                                        SmallVectorImpl<CanQualType> &ArgTys) {
+  AddedStructorArgs Added;
+  // TODO: 'for base' flag
+  if (isa<CXXDestructorDecl>(GD.getDecl()) &&
+      GD.getDtorType() == Dtor_Deleting) {
+    // The scalar deleting destructor takes an implicit int parameter.
+    ArgTys.push_back(getContext().IntTy);
+    ++Added.Suffix;
+  }
+  auto *CD = dyn_cast<CXXConstructorDecl>(GD.getDecl());
+  if (!CD)
+    return Added;
+
+  // All parameters are already in place except is_most_derived, which goes
+  // after 'this' if it's variadic and last if it's not.
+
+  const CXXRecordDecl *Class = CD->getParent();
+  const FunctionProtoType *FPT = CD->getType()->castAs<FunctionProtoType>();
+  if (Class->getNumVBases()) {
+    if (FPT->isVariadic()) {
+      ArgTys.insert(ArgTys.begin() + 1, getContext().IntTy);
+      ++Added.Prefix;
+    } else {
+      ArgTys.push_back(getContext().IntTy);
+      ++Added.Suffix;
+    }
+  }
+
+  return Added;
+}
+
+void MicrosoftCXXABI::setCXXDestructorDLLStorage(llvm::GlobalValue *GV,
+                                                 const CXXDestructorDecl *Dtor,
+                                                 CXXDtorType DT) const {
+  // Deleting destructor variants are never imported or exported. Give them the
+  // default storage class.
+  if (DT == Dtor_Deleting) {
+    GV->setDLLStorageClass(llvm::GlobalValue::DefaultStorageClass);
+  } else {
+    const NamedDecl *ND = Dtor;
+    CGM.setDLLImportDLLExport(GV, ND);
+  }
+}
+
+llvm::GlobalValue::LinkageTypes MicrosoftCXXABI::getCXXDestructorLinkage(
+    GVALinkage Linkage, const CXXDestructorDecl *Dtor, CXXDtorType DT) const {
+  // Internal things are always internal, regardless of attributes. After this,
+  // we know the thunk is externally visible.
+  if (Linkage == GVA_Internal)
+    return llvm::GlobalValue::InternalLinkage;
+
+  switch (DT) {
+  case Dtor_Base:
+    // The base destructor most closely tracks the user-declared constructor, so
+    // we delegate back to the normal declarator case.
+    return CGM.getLLVMLinkageForDeclarator(Dtor, Linkage,
+                                           /*IsConstantVariable=*/false);
+  case Dtor_Complete:
+    // The complete destructor is like an inline function, but it may be
+    // imported and therefore must be exported as well. This requires changing
+    // the linkage if a DLL attribute is present.
+    if (Dtor->hasAttr<DLLExportAttr>())
+      return llvm::GlobalValue::WeakODRLinkage;
+    if (Dtor->hasAttr<DLLImportAttr>())
+      return llvm::GlobalValue::AvailableExternallyLinkage;
+    return llvm::GlobalValue::LinkOnceODRLinkage;
+  case Dtor_Deleting:
+    // Deleting destructors are like inline functions. They have vague linkage
+    // and are emitted everywhere they are used. They are internal if the class
+    // is internal.
+    return llvm::GlobalValue::LinkOnceODRLinkage;
+  case Dtor_Comdat:
+    llvm_unreachable("MS C++ ABI does not support comdat dtors");
+  }
+  llvm_unreachable("invalid dtor type");
+}
+
+void MicrosoftCXXABI::EmitCXXDestructors(const CXXDestructorDecl *D) {
+  // The TU defining a dtor is only guaranteed to emit a base destructor.  All
+  // other destructor variants are delegating thunks.
+  CGM.EmitGlobal(GlobalDecl(D, Dtor_Base));
+
+  // If the class is dllexported, emit the complete (vbase) destructor wherever
+  // the base dtor is emitted.
+  // FIXME: To match MSVC, this should only be done when the class is exported
+  // with -fdllexport-inlines enabled.
+  if (D->getParent()->getNumVBases() > 0 && D->hasAttr<DLLExportAttr>())
+    CGM.EmitGlobal(GlobalDecl(D, Dtor_Complete));
+}
+
+CharUnits
+MicrosoftCXXABI::getVirtualFunctionPrologueThisAdjustment(GlobalDecl GD) {
+  const CXXMethodDecl *MD = cast<CXXMethodDecl>(GD.getDecl());
+
+  if (const CXXDestructorDecl *DD = dyn_cast<CXXDestructorDecl>(MD)) {
+    // Complete destructors take a pointer to the complete object as a
+    // parameter, thus don't need this adjustment.
+    if (GD.getDtorType() == Dtor_Complete)
+      return CharUnits();
+
+    // There's no Dtor_Base in vftable but it shares the this adjustment with
+    // the deleting one, so look it up instead.
+    GD = GlobalDecl(DD, Dtor_Deleting);
+  }
+
+  MethodVFTableLocation ML =
+      CGM.getMicrosoftVTableContext().getMethodVFTableLocation(GD);
+  CharUnits Adjustment = ML.VFPtrOffset;
+
+  // Normal virtual instance methods need to adjust from the vfptr that first
+  // defined the virtual method to the virtual base subobject, but destructors
+  // do not.  The vector deleting destructor thunk applies this adjustment for
+  // us if necessary.
+  if (isa<CXXDestructorDecl>(MD))
+    Adjustment = CharUnits::Zero();
+
+  if (ML.VBase) {
+    const ASTRecordLayout &DerivedLayout =
+        getContext().getASTRecordLayout(MD->getParent());
+    Adjustment += DerivedLayout.getVBaseClassOffset(ML.VBase);
+  }
+
+  return Adjustment;
+}
+
+Address MicrosoftCXXABI::adjustThisArgumentForVirtualFunctionCall(
+    CodeGenFunction &CGF, GlobalDecl GD, Address This,
+    bool VirtualCall) {
+  if (!VirtualCall) {
+    // If the call of a virtual function is not virtual, we just have to
+    // compensate for the adjustment the virtual function does in its prologue.
+    CharUnits Adjustment = getVirtualFunctionPrologueThisAdjustment(GD);
+    if (Adjustment.isZero())
+      return This;
+
+    This = CGF.Builder.CreateElementBitCast(This, CGF.Int8Ty);
+    assert(Adjustment.isPositive());
+    return CGF.Builder.CreateConstByteGEP(This, Adjustment);
+  }
+
+  const CXXMethodDecl *MD = cast<CXXMethodDecl>(GD.getDecl());
+
+  GlobalDecl LookupGD = GD;
+  if (const CXXDestructorDecl *DD = dyn_cast<CXXDestructorDecl>(MD)) {
+    // Complete dtors take a pointer to the complete object,
+    // thus don't need adjustment.
+    if (GD.getDtorType() == Dtor_Complete)
+      return This;
+
+    // There's only Dtor_Deleting in vftable but it shares the this adjustment
+    // with the base one, so look up the deleting one instead.
+    LookupGD = GlobalDecl(DD, Dtor_Deleting);
+  }
+  MethodVFTableLocation ML =
+      CGM.getMicrosoftVTableContext().getMethodVFTableLocation(LookupGD);
+
+  CharUnits StaticOffset = ML.VFPtrOffset;
+
+  // Base destructors expect 'this' to point to the beginning of the base
+  // subobject, not the first vfptr that happens to contain the virtual dtor.
+  // However, we still need to apply the virtual base adjustment.
+  if (isa<CXXDestructorDecl>(MD) && GD.getDtorType() == Dtor_Base)
+    StaticOffset = CharUnits::Zero();
+
+  Address Result = This;
+  if (ML.VBase) {
+    Result = CGF.Builder.CreateElementBitCast(Result, CGF.Int8Ty);
+
+    const CXXRecordDecl *Derived = MD->getParent();
+    const CXXRecordDecl *VBase = ML.VBase;
+    llvm::Value *VBaseOffset =
+      GetVirtualBaseClassOffset(CGF, Result, Derived, VBase);
+    llvm::Value *VBasePtr =
+      CGF.Builder.CreateInBoundsGEP(Result.getPointer(), VBaseOffset);
+    CharUnits VBaseAlign =
+      CGF.CGM.getVBaseAlignment(Result.getAlignment(), Derived, VBase);
+    Result = Address(VBasePtr, VBaseAlign);
+  }
+  if (!StaticOffset.isZero()) {
+    assert(StaticOffset.isPositive());
+    Result = CGF.Builder.CreateElementBitCast(Result, CGF.Int8Ty);
+    if (ML.VBase) {
+      // Non-virtual adjustment might result in a pointer outside the allocated
+      // object, e.g. if the final overrider class is laid out after the virtual
+      // base that declares a method in the most derived class.
+      // FIXME: Update the code that emits this adjustment in thunks prologues.
+      Result = CGF.Builder.CreateConstByteGEP(Result, StaticOffset);
+    } else {
+      Result = CGF.Builder.CreateConstInBoundsByteGEP(Result, StaticOffset);
+    }
+  }
+  return Result;
+}
+
+void MicrosoftCXXABI::addImplicitStructorParams(CodeGenFunction &CGF,
+                                                QualType &ResTy,
+                                                FunctionArgList &Params) {
+  ASTContext &Context = getContext();
+  const CXXMethodDecl *MD = cast<CXXMethodDecl>(CGF.CurGD.getDecl());
+  assert(isa<CXXConstructorDecl>(MD) || isa<CXXDestructorDecl>(MD));
+  if (isa<CXXConstructorDecl>(MD) && MD->getParent()->getNumVBases()) {
+    auto *IsMostDerived = ImplicitParamDecl::Create(
+        Context, /*DC=*/nullptr, CGF.CurGD.getDecl()->getLocation(),
+        &Context.Idents.get("is_most_derived"), Context.IntTy,
+        ImplicitParamDecl::Other);
+    // The 'most_derived' parameter goes second if the ctor is variadic and last
+    // if it's not.  Dtors can't be variadic.
+    const FunctionProtoType *FPT = MD->getType()->castAs<FunctionProtoType>();
+    if (FPT->isVariadic())
+      Params.insert(Params.begin() + 1, IsMostDerived);
+    else
+      Params.push_back(IsMostDerived);
+    getStructorImplicitParamDecl(CGF) = IsMostDerived;
+  } else if (isDeletingDtor(CGF.CurGD)) {
+    auto *ShouldDelete = ImplicitParamDecl::Create(
+        Context, /*DC=*/nullptr, CGF.CurGD.getDecl()->getLocation(),
+        &Context.Idents.get("should_call_delete"), Context.IntTy,
+        ImplicitParamDecl::Other);
+    Params.push_back(ShouldDelete);
+    getStructorImplicitParamDecl(CGF) = ShouldDelete;
+  }
+}
+
+void MicrosoftCXXABI::EmitInstanceFunctionProlog(CodeGenFunction &CGF) {
+  // Naked functions have no prolog.
+  if (CGF.CurFuncDecl && CGF.CurFuncDecl->hasAttr<NakedAttr>())
+    return;
+
+  // Overridden virtual methods of non-primary bases need to adjust the incoming
+  // 'this' pointer in the prologue. In this hierarchy, C::b will subtract
+  // sizeof(void*) to adjust from B* to C*:
+  //   struct A { virtual void a(); };
+  //   struct B { virtual void b(); };
+  //   struct C : A, B { virtual void b(); };
+  //
+  // Leave the value stored in the 'this' alloca unadjusted, so that the
+  // debugger sees the unadjusted value. Microsoft debuggers require this, and
+  // will apply the ThisAdjustment in the method type information.
+  // FIXME: Do something better for DWARF debuggers, which won't expect this,
+  // without making our codegen depend on debug info settings.
+  llvm::Value *This = loadIncomingCXXThis(CGF);
+  const CXXMethodDecl *MD = cast<CXXMethodDecl>(CGF.CurGD.getDecl());
+  if (!CGF.CurFuncIsThunk && MD->isVirtual()) {
+    CharUnits Adjustment = getVirtualFunctionPrologueThisAdjustment(CGF.CurGD);
+    if (!Adjustment.isZero()) {
+      unsigned AS = cast<llvm::PointerType>(This->getType())->getAddressSpace();
+      llvm::Type *charPtrTy = CGF.Int8Ty->getPointerTo(AS),
+                 *thisTy = This->getType();
+      This = CGF.Builder.CreateBitCast(This, charPtrTy);
+      assert(Adjustment.isPositive());
+      This = CGF.Builder.CreateConstInBoundsGEP1_32(CGF.Int8Ty, This,
+                                                    -Adjustment.getQuantity());
+      This = CGF.Builder.CreateBitCast(This, thisTy, "this.adjusted");
+    }
+  }
+  setCXXABIThisValue(CGF, This);
+
+  // If this is a function that the ABI specifies returns 'this', initialize
+  // the return slot to 'this' at the start of the function.
+  //
+  // Unlike the setting of return types, this is done within the ABI
+  // implementation instead of by clients of CGCXXABI because:
+  // 1) getThisValue is currently protected
+  // 2) in theory, an ABI could implement 'this' returns some other way;
+  //    HasThisReturn only specifies a contract, not the implementation
+  if (HasThisReturn(CGF.CurGD))
+    CGF.Builder.CreateStore(getThisValue(CGF), CGF.ReturnValue);
+  else if (hasMostDerivedReturn(CGF.CurGD))
+    CGF.Builder.CreateStore(CGF.EmitCastToVoidPtr(getThisValue(CGF)),
+                            CGF.ReturnValue);
+
+  if (isa<CXXConstructorDecl>(MD) && MD->getParent()->getNumVBases()) {
+    assert(getStructorImplicitParamDecl(CGF) &&
+           "no implicit parameter for a constructor with virtual bases?");
+    getStructorImplicitParamValue(CGF)
+      = CGF.Builder.CreateLoad(
+          CGF.GetAddrOfLocalVar(getStructorImplicitParamDecl(CGF)),
+          "is_most_derived");
+  }
+
+  if (isDeletingDtor(CGF.CurGD)) {
+    assert(getStructorImplicitParamDecl(CGF) &&
+           "no implicit parameter for a deleting destructor?");
+    getStructorImplicitParamValue(CGF)
+      = CGF.Builder.CreateLoad(
+          CGF.GetAddrOfLocalVar(getStructorImplicitParamDecl(CGF)),
+          "should_call_delete");
+  }
+}
+
+CGCXXABI::AddedStructorArgs MicrosoftCXXABI::addImplicitConstructorArgs(
+    CodeGenFunction &CGF, const CXXConstructorDecl *D, CXXCtorType Type,
+    bool ForVirtualBase, bool Delegating, CallArgList &Args) {
+  assert(Type == Ctor_Complete || Type == Ctor_Base);
+
+  // Check if we need a 'most_derived' parameter.
+  if (!D->getParent()->getNumVBases())
+    return AddedStructorArgs{};
+
+  // Add the 'most_derived' argument second if we are variadic or last if not.
+  const FunctionProtoType *FPT = D->getType()->castAs<FunctionProtoType>();
+  llvm::Value *MostDerivedArg;
+  if (Delegating) {
+    MostDerivedArg = getStructorImplicitParamValue(CGF);
+  } else {
+    MostDerivedArg = llvm::ConstantInt::get(CGM.Int32Ty, Type == Ctor_Complete);
+  }
+  RValue RV = RValue::get(MostDerivedArg);
+  if (FPT->isVariadic()) {
+    Args.insert(Args.begin() + 1, CallArg(RV, getContext().IntTy));
+    return AddedStructorArgs::prefix(1);
+  }
+  Args.add(RV, getContext().IntTy);
+  return AddedStructorArgs::suffix(1);
+}
+
+void MicrosoftCXXABI::EmitDestructorCall(CodeGenFunction &CGF,
+                                         const CXXDestructorDecl *DD,
+                                         CXXDtorType Type, bool ForVirtualBase,
+                                         bool Delegating, Address This,
+                                         QualType ThisTy) {
+  // Use the base destructor variant in place of the complete destructor variant
+  // if the class has no virtual bases. This effectively implements some of the
+  // -mconstructor-aliases optimization, but as part of the MS C++ ABI.
+  if (Type == Dtor_Complete && DD->getParent()->getNumVBases() == 0)
+    Type = Dtor_Base;
+
+  GlobalDecl GD(DD, Type);
+  CGCallee Callee = CGCallee::forDirect(CGM.getAddrOfCXXStructor(GD), GD);
+
+  if (DD->isVirtual()) {
+    assert(Type != CXXDtorType::Dtor_Deleting &&
+           "The deleting destructor should only be called via a virtual call");
+    This = adjustThisArgumentForVirtualFunctionCall(CGF, GlobalDecl(DD, Type),
+                                                    This, false);
+  }
+
+  llvm::BasicBlock *BaseDtorEndBB = nullptr;
+  if (ForVirtualBase && isa<CXXConstructorDecl>(CGF.CurCodeDecl)) {
+    BaseDtorEndBB = EmitDtorCompleteObjectHandler(CGF);
+  }
+
+  CGF.EmitCXXDestructorCall(GD, Callee, This.getPointer(), ThisTy,
+                            /*ImplicitParam=*/nullptr,
+                            /*ImplicitParamTy=*/QualType(), nullptr);
+  if (BaseDtorEndBB) {
+    // Complete object handler should continue to be the remaining
+    CGF.Builder.CreateBr(BaseDtorEndBB);
+    CGF.EmitBlock(BaseDtorEndBB);
+  }
+}
+
+void MicrosoftCXXABI::emitVTableTypeMetadata(const VPtrInfo &Info,
+                                             const CXXRecordDecl *RD,
+                                             llvm::GlobalVariable *VTable) {
+  if (!CGM.getCodeGenOpts().LTOUnit)
+    return;
+
+  // TODO: Should VirtualFunctionElimination also be supported here?
+  // See similar handling in CodeGenModule::EmitVTableTypeMetadata.
+  if (CGM.getCodeGenOpts().WholeProgramVTables) {
+    llvm::GlobalObject::VCallVisibility TypeVis =
+        CGM.GetVCallVisibilityLevel(RD);
+    if (TypeVis != llvm::GlobalObject::VCallVisibilityPublic)
+      VTable->setVCallVisibilityMetadata(TypeVis);
+  }
+
+  // The location of the first virtual function pointer in the virtual table,
+  // aka the "address point" on Itanium. This is at offset 0 if RTTI is
+  // disabled, or sizeof(void*) if RTTI is enabled.
+  CharUnits AddressPoint =
+      getContext().getLangOpts().RTTIData
+          ? getContext().toCharUnitsFromBits(
+                getContext().getTargetInfo().getPointerWidth(0))
+          : CharUnits::Zero();
+
+  if (Info.PathToIntroducingObject.empty()) {
+    CGM.AddVTableTypeMetadata(VTable, AddressPoint, RD);
+    return;
+  }
+
+  // Add a bitset entry for the least derived base belonging to this vftable.
+  CGM.AddVTableTypeMetadata(VTable, AddressPoint,
+                            Info.PathToIntroducingObject.back());
+
+  // Add a bitset entry for each derived class that is laid out at the same
+  // offset as the least derived base.
+  for (unsigned I = Info.PathToIntroducingObject.size() - 1; I != 0; --I) {
+    const CXXRecordDecl *DerivedRD = Info.PathToIntroducingObject[I - 1];
+    const CXXRecordDecl *BaseRD = Info.PathToIntroducingObject[I];
+
+    const ASTRecordLayout &Layout =
+        getContext().getASTRecordLayout(DerivedRD);
+    CharUnits Offset;
+    auto VBI = Layout.getVBaseOffsetsMap().find(BaseRD);
+    if (VBI == Layout.getVBaseOffsetsMap().end())
+      Offset = Layout.getBaseClassOffset(BaseRD);
+    else
+      Offset = VBI->second.VBaseOffset;
+    if (!Offset.isZero())
+      return;
+    CGM.AddVTableTypeMetadata(VTable, AddressPoint, DerivedRD);
+  }
+
+  // Finally do the same for the most derived class.
+  if (Info.FullOffsetInMDC.isZero())
+    CGM.AddVTableTypeMetadata(VTable, AddressPoint, RD);
+}
+
+void MicrosoftCXXABI::emitVTableDefinitions(CodeGenVTables &CGVT,
+                                            const CXXRecordDecl *RD) {
+  MicrosoftVTableContext &VFTContext = CGM.getMicrosoftVTableContext();
+  const VPtrInfoVector &VFPtrs = VFTContext.getVFPtrOffsets(RD);
+
+  for (const std::unique_ptr<VPtrInfo>& Info : VFPtrs) {
+    llvm::GlobalVariable *VTable = getAddrOfVTable(RD, Info->FullOffsetInMDC);
+    if (VTable->hasInitializer())
+      continue;
+
+    const VTableLayout &VTLayout =
+      VFTContext.getVFTableLayout(RD, Info->FullOffsetInMDC);
+
+    llvm::Constant *RTTI = nullptr;
+    if (any_of(VTLayout.vtable_components(),
+               [](const VTableComponent &VTC) { return VTC.isRTTIKind(); }))
+      RTTI = getMSCompleteObjectLocator(RD, *Info);
+
+    ConstantInitBuilder Builder(CGM);
+    auto Components = Builder.beginStruct();
+    CGVT.createVTableInitializer(Components, VTLayout, RTTI);
+    Components.finishAndSetAsInitializer(VTable);
+
+    emitVTableTypeMetadata(*Info, RD, VTable);
+  }
+}
+
+bool MicrosoftCXXABI::isVirtualOffsetNeededForVTableField(
+    CodeGenFunction &CGF, CodeGenFunction::VPtr Vptr) {
+  return Vptr.NearestVBase != nullptr;
+}
+
+llvm::Value *MicrosoftCXXABI::getVTableAddressPointInStructor(
+    CodeGenFunction &CGF, const CXXRecordDecl *VTableClass, BaseSubobject Base,
+    const CXXRecordDecl *NearestVBase) {
+  llvm::Constant *VTableAddressPoint = getVTableAddressPoint(Base, VTableClass);
+  if (!VTableAddressPoint) {
+    assert(Base.getBase()->getNumVBases() &&
+           !getContext().getASTRecordLayout(Base.getBase()).hasOwnVFPtr());
+  }
+  return VTableAddressPoint;
+}
+
+static void mangleVFTableName(MicrosoftMangleContext &MangleContext,
+                              const CXXRecordDecl *RD, const VPtrInfo &VFPtr,
+                              SmallString<256> &Name) {
+  llvm::raw_svector_ostream Out(Name);
+  MangleContext.mangleCXXVFTable(RD, VFPtr.MangledPath, Out);
+}
+
+llvm::Constant *
+MicrosoftCXXABI::getVTableAddressPoint(BaseSubobject Base,
+                                       const CXXRecordDecl *VTableClass) {
+  (void)getAddrOfVTable(VTableClass, Base.getBaseOffset());
+  VFTableIdTy ID(VTableClass, Base.getBaseOffset());
+  return VFTablesMap[ID];
+}
+
+llvm::Constant *MicrosoftCXXABI::getVTableAddressPointForConstExpr(
+    BaseSubobject Base, const CXXRecordDecl *VTableClass) {
+  llvm::Constant *VFTable = getVTableAddressPoint(Base, VTableClass);
+  assert(VFTable && "Couldn't find a vftable for the given base?");
+  return VFTable;
+}
+
+llvm::GlobalVariable *MicrosoftCXXABI::getAddrOfVTable(const CXXRecordDecl *RD,
+                                                       CharUnits VPtrOffset) {
+  // getAddrOfVTable may return 0 if asked to get an address of a vtable which
+  // shouldn't be used in the given record type. We want to cache this result in
+  // VFTablesMap, thus a simple zero check is not sufficient.
+
+  VFTableIdTy ID(RD, VPtrOffset);
+  VTablesMapTy::iterator I;
+  bool Inserted;
+  std::tie(I, Inserted) = VTablesMap.insert(std::make_pair(ID, nullptr));
+  if (!Inserted)
+    return I->second;
+
+  llvm::GlobalVariable *&VTable = I->second;
+
+  MicrosoftVTableContext &VTContext = CGM.getMicrosoftVTableContext();
+  const VPtrInfoVector &VFPtrs = VTContext.getVFPtrOffsets(RD);
+
+  if (DeferredVFTables.insert(RD).second) {
+    // We haven't processed this record type before.
+    // Queue up this vtable for possible deferred emission.
+    CGM.addDeferredVTable(RD);
+
+#ifndef NDEBUG
+    // Create all the vftables at once in order to make sure each vftable has
+    // a unique mangled name.
+    llvm::StringSet<> ObservedMangledNames;
+    for (size_t J = 0, F = VFPtrs.size(); J != F; ++J) {
+      SmallString<256> Name;
+      mangleVFTableName(getMangleContext(), RD, *VFPtrs[J], Name);
+      if (!ObservedMangledNames.insert(Name.str()).second)
+        llvm_unreachable("Already saw this mangling before?");
+    }
+#endif
+  }
+
+  const std::unique_ptr<VPtrInfo> *VFPtrI = std::find_if(
+      VFPtrs.begin(), VFPtrs.end(), [&](const std::unique_ptr<VPtrInfo>& VPI) {
+        return VPI->FullOffsetInMDC == VPtrOffset;
+      });
+  if (VFPtrI == VFPtrs.end()) {
+    VFTablesMap[ID] = nullptr;
+    return nullptr;
+  }
+  const std::unique_ptr<VPtrInfo> &VFPtr = *VFPtrI;
+
+  SmallString<256> VFTableName;
+  mangleVFTableName(getMangleContext(), RD, *VFPtr, VFTableName);
+
+  // Classes marked __declspec(dllimport) need vftables generated on the
+  // import-side in order to support features like constexpr.  No other
+  // translation unit relies on the emission of the local vftable, translation
+  // units are expected to generate them as needed.
+  //
+  // Because of this unique behavior, we maintain this logic here instead of
+  // getVTableLinkage.
+  llvm::GlobalValue::LinkageTypes VFTableLinkage =
+      RD->hasAttr<DLLImportAttr>() ? llvm::GlobalValue::LinkOnceODRLinkage
+                                   : CGM.getVTableLinkage(RD);
+  bool VFTableComesFromAnotherTU =
+      llvm::GlobalValue::isAvailableExternallyLinkage(VFTableLinkage) ||
+      llvm::GlobalValue::isExternalLinkage(VFTableLinkage);
+  bool VTableAliasIsRequred =
+      !VFTableComesFromAnotherTU && getContext().getLangOpts().RTTIData;
+
+  if (llvm::GlobalValue *VFTable =
+          CGM.getModule().getNamedGlobal(VFTableName)) {
+    VFTablesMap[ID] = VFTable;
+    VTable = VTableAliasIsRequred
+                 ? cast<llvm::GlobalVariable>(
+                       cast<llvm::GlobalAlias>(VFTable)->getBaseObject())
+                 : cast<llvm::GlobalVariable>(VFTable);
+    return VTable;
+  }
+
+  const VTableLayout &VTLayout =
+      VTContext.getVFTableLayout(RD, VFPtr->FullOffsetInMDC);
+  llvm::GlobalValue::LinkageTypes VTableLinkage =
+      VTableAliasIsRequred ? llvm::GlobalValue::PrivateLinkage : VFTableLinkage;
+
+  StringRef VTableName = VTableAliasIsRequred ? StringRef() : VFTableName.str();
+
+  llvm::Type *VTableType = CGM.getVTables().getVTableType(VTLayout);
+
+  // Create a backing variable for the contents of VTable.  The VTable may
+  // or may not include space for a pointer to RTTI data.
+  llvm::GlobalValue *VFTable;
+  VTable = new llvm::GlobalVariable(CGM.getModule(), VTableType,
+                                    /*isConstant=*/true, VTableLinkage,
+                                    /*Initializer=*/nullptr, VTableName);
+  VTable->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
+
+  llvm::Comdat *C = nullptr;
+  if (!VFTableComesFromAnotherTU &&
+      (llvm::GlobalValue::isWeakForLinker(VFTableLinkage) ||
+       (llvm::GlobalValue::isLocalLinkage(VFTableLinkage) &&
+        VTableAliasIsRequred)))
+    C = CGM.getModule().getOrInsertComdat(VFTableName.str());
+
+  // Only insert a pointer into the VFTable for RTTI data if we are not
+  // importing it.  We never reference the RTTI data directly so there is no
+  // need to make room for it.
+  if (VTableAliasIsRequred) {
+    llvm::Value *GEPIndices[] = {llvm::ConstantInt::get(CGM.Int32Ty, 0),
+                                 llvm::ConstantInt::get(CGM.Int32Ty, 0),
+                                 llvm::ConstantInt::get(CGM.Int32Ty, 1)};
+    // Create a GEP which points just after the first entry in the VFTable,
+    // this should be the location of the first virtual method.
+    llvm::Constant *VTableGEP = llvm::ConstantExpr::getInBoundsGetElementPtr(
+        VTable->getValueType(), VTable, GEPIndices);
+    if (llvm::GlobalValue::isWeakForLinker(VFTableLinkage)) {
+      VFTableLinkage = llvm::GlobalValue::ExternalLinkage;
+      if (C)
+        C->setSelectionKind(llvm::Comdat::Largest);
+    }
+    VFTable = llvm::GlobalAlias::create(CGM.Int8PtrTy,
+                                        /*AddressSpace=*/0, VFTableLinkage,
+                                        VFTableName.str(), VTableGEP,
+                                        &CGM.getModule());
+    VFTable->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
+  } else {
+    // We don't need a GlobalAlias to be a symbol for the VTable if we won't
+    // be referencing any RTTI data.
+    // The GlobalVariable will end up being an appropriate definition of the
+    // VFTable.
+    VFTable = VTable;
+  }
+  if (C)
+    VTable->setComdat(C);
+
+  if (RD->hasAttr<DLLExportAttr>())
+    VFTable->setDLLStorageClass(llvm::GlobalValue::DLLExportStorageClass);
+
+  VFTablesMap[ID] = VFTable;
+  return VTable;
+}
+
+CGCallee MicrosoftCXXABI::getVirtualFunctionPointer(CodeGenFunction &CGF,
+                                                    GlobalDecl GD,
+                                                    Address This,
+                                                    llvm::Type *Ty,
+                                                    SourceLocation Loc) {
+  CGBuilderTy &Builder = CGF.Builder;
+
+  Ty = Ty->getPointerTo()->getPointerTo();
+  Address VPtr =
+      adjustThisArgumentForVirtualFunctionCall(CGF, GD, This, true);
+
+  auto *MethodDecl = cast<CXXMethodDecl>(GD.getDecl());
+  llvm::Value *VTable = CGF.GetVTablePtr(VPtr, Ty, MethodDecl->getParent());
+
+  MicrosoftVTableContext &VFTContext = CGM.getMicrosoftVTableContext();
+  MethodVFTableLocation ML = VFTContext.getMethodVFTableLocation(GD);
+
+  // Compute the identity of the most derived class whose virtual table is
+  // located at the MethodVFTableLocation ML.
+  auto getObjectWithVPtr = [&] {
+    return llvm::find_if(VFTContext.getVFPtrOffsets(
+                             ML.VBase ? ML.VBase : MethodDecl->getParent()),
+                         [&](const std::unique_ptr<VPtrInfo> &Info) {
+                           return Info->FullOffsetInMDC == ML.VFPtrOffset;
+                         })
+        ->get()
+        ->ObjectWithVPtr;
+  };
+
+  llvm::Value *VFunc;
+  if (CGF.ShouldEmitVTableTypeCheckedLoad(MethodDecl->getParent())) {
+    VFunc = CGF.EmitVTableTypeCheckedLoad(
+        getObjectWithVPtr(), VTable,
+        ML.Index * CGM.getContext().getTargetInfo().getPointerWidth(0) / 8);
+  } else {
+    if (CGM.getCodeGenOpts().PrepareForLTO)
+      CGF.EmitTypeMetadataCodeForVCall(getObjectWithVPtr(), VTable, Loc);
+
+    llvm::Value *VFuncPtr =
+        Builder.CreateConstInBoundsGEP1_64(VTable, ML.Index, "vfn");
+    VFunc = Builder.CreateAlignedLoad(VFuncPtr, CGF.getPointerAlign());
+  }
+
+  CGCallee Callee(GD, VFunc);
+  return Callee;
+}
+
+llvm::Value *MicrosoftCXXABI::EmitVirtualDestructorCall(
+    CodeGenFunction &CGF, const CXXDestructorDecl *Dtor, CXXDtorType DtorType,
+    Address This, DeleteOrMemberCallExpr E) {
+  auto *CE = E.dyn_cast<const CXXMemberCallExpr *>();
+  auto *D = E.dyn_cast<const CXXDeleteExpr *>();
+  assert((CE != nullptr) ^ (D != nullptr));
+  assert(CE == nullptr || CE->arg_begin() == CE->arg_end());
+  assert(DtorType == Dtor_Deleting || DtorType == Dtor_Complete);
+
+  // We have only one destructor in the vftable but can get both behaviors
+  // by passing an implicit int parameter.
+  GlobalDecl GD(Dtor, Dtor_Deleting);
+  const CGFunctionInfo *FInfo =
+      &CGM.getTypes().arrangeCXXStructorDeclaration(GD);
+  llvm::FunctionType *Ty = CGF.CGM.getTypes().GetFunctionType(*FInfo);
+  CGCallee Callee = CGCallee::forVirtual(CE, GD, This, Ty);
+
+  ASTContext &Context = getContext();
+  llvm::Value *ImplicitParam = llvm::ConstantInt::get(
+      llvm::IntegerType::getInt32Ty(CGF.getLLVMContext()),
+      DtorType == Dtor_Deleting);
+
+  QualType ThisTy;
+  if (CE) {
+    ThisTy = CE->getObjectType();
+  } else {
+    ThisTy = D->getDestroyedType();
+  }
+
+  This = adjustThisArgumentForVirtualFunctionCall(CGF, GD, This, true);
+  RValue RV = CGF.EmitCXXDestructorCall(GD, Callee, This.getPointer(), ThisTy,
+                                        ImplicitParam, Context.IntTy, CE);
+  return RV.getScalarVal();
+}
+
+const VBTableGlobals &
+MicrosoftCXXABI::enumerateVBTables(const CXXRecordDecl *RD) {
+  // At this layer, we can key the cache off of a single class, which is much
+  // easier than caching each vbtable individually.
+  llvm::DenseMap<const CXXRecordDecl*, VBTableGlobals>::iterator Entry;
+  bool Added;
+  std::tie(Entry, Added) =
+      VBTablesMap.insert(std::make_pair(RD, VBTableGlobals()));
+  VBTableGlobals &VBGlobals = Entry->second;
+  if (!Added)
+    return VBGlobals;
+
+  MicrosoftVTableContext &Context = CGM.getMicrosoftVTableContext();
+  VBGlobals.VBTables = &Context.enumerateVBTables(RD);
+
+  // Cache the globals for all vbtables so we don't have to recompute the
+  // mangled names.
+  llvm::GlobalVariable::LinkageTypes Linkage = CGM.getVTableLinkage(RD);
+  for (VPtrInfoVector::const_iterator I = VBGlobals.VBTables->begin(),
+                                      E = VBGlobals.VBTables->end();
+       I != E; ++I) {
+    VBGlobals.Globals.push_back(getAddrOfVBTable(**I, RD, Linkage));
+  }
+
+  return VBGlobals;
+}
+
+llvm::Function *
+MicrosoftCXXABI::EmitVirtualMemPtrThunk(const CXXMethodDecl *MD,
+                                        const MethodVFTableLocation &ML) {
+  assert(!isa<CXXConstructorDecl>(MD) && !isa<CXXDestructorDecl>(MD) &&
+         "can't form pointers to ctors or virtual dtors");
+
+  // Calculate the mangled name.
+  SmallString<256> ThunkName;
+  llvm::raw_svector_ostream Out(ThunkName);
+  getMangleContext().mangleVirtualMemPtrThunk(MD, ML, Out);
+
+  // If the thunk has been generated previously, just return it.
+  if (llvm::GlobalValue *GV = CGM.getModule().getNamedValue(ThunkName))
+    return cast<llvm::Function>(GV);
+
+  // Create the llvm::Function.
+  const CGFunctionInfo &FnInfo =
+      CGM.getTypes().arrangeUnprototypedMustTailThunk(MD);
+  llvm::FunctionType *ThunkTy = CGM.getTypes().GetFunctionType(FnInfo);
+  llvm::Function *ThunkFn =
+      llvm::Function::Create(ThunkTy, llvm::Function::ExternalLinkage,
+                             ThunkName.str(), &CGM.getModule());
+  assert(ThunkFn->getName() == ThunkName && "name was uniqued!");
+
+  ThunkFn->setLinkage(MD->isExternallyVisible()
+                          ? llvm::GlobalValue::LinkOnceODRLinkage
+                          : llvm::GlobalValue::InternalLinkage);
+  if (MD->isExternallyVisible())
+    ThunkFn->setComdat(CGM.getModule().getOrInsertComdat(ThunkFn->getName()));
+
+  CGM.SetLLVMFunctionAttributes(MD, FnInfo, ThunkFn);
+  CGM.SetLLVMFunctionAttributesForDefinition(MD, ThunkFn);
+
+  // Add the "thunk" attribute so that LLVM knows that the return type is
+  // meaningless. These thunks can be used to call functions with differing
+  // return types, and the caller is required to cast the prototype
+  // appropriately to extract the correct value.
+  ThunkFn->addFnAttr("thunk");
+
+  // These thunks can be compared, so they are not unnamed.
+  ThunkFn->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::None);
+
+  // Start codegen.
+  CodeGenFunction CGF(CGM);
+  CGF.CurGD = GlobalDecl(MD);
+  CGF.CurFuncIsThunk = true;
+
+  // Build FunctionArgs, but only include the implicit 'this' parameter
+  // declaration.
+  FunctionArgList FunctionArgs;
+  buildThisParam(CGF, FunctionArgs);
+
+  // Start defining the function.
+  CGF.StartFunction(GlobalDecl(), FnInfo.getReturnType(), ThunkFn, FnInfo,
+                    FunctionArgs, MD->getLocation(), SourceLocation());
+  setCXXABIThisValue(CGF, loadIncomingCXXThis(CGF));
+
+  // Load the vfptr and then callee from the vftable.  The callee should have
+  // adjusted 'this' so that the vfptr is at offset zero.
+  llvm::Value *VTable = CGF.GetVTablePtr(
+      getThisAddress(CGF), ThunkTy->getPointerTo()->getPointerTo(), MD->getParent());
+
+  llvm::Value *VFuncPtr =
+      CGF.Builder.CreateConstInBoundsGEP1_64(VTable, ML.Index, "vfn");
+  llvm::Value *Callee =
+    CGF.Builder.CreateAlignedLoad(VFuncPtr, CGF.getPointerAlign());
+
+  CGF.EmitMustTailThunk(MD, getThisValue(CGF), {ThunkTy, Callee});
+
+  return ThunkFn;
+}
+
+void MicrosoftCXXABI::emitVirtualInheritanceTables(const CXXRecordDecl *RD) {
+  const VBTableGlobals &VBGlobals = enumerateVBTables(RD);
+  for (unsigned I = 0, E = VBGlobals.VBTables->size(); I != E; ++I) {
+    const std::unique_ptr<VPtrInfo>& VBT = (*VBGlobals.VBTables)[I];
+    llvm::GlobalVariable *GV = VBGlobals.Globals[I];
+    if (GV->isDeclaration())
+      emitVBTableDefinition(*VBT, RD, GV);
+  }
+}
+
+llvm::GlobalVariable *
+MicrosoftCXXABI::getAddrOfVBTable(const VPtrInfo &VBT, const CXXRecordDecl *RD,
+                                  llvm::GlobalVariable::LinkageTypes Linkage) {
+  SmallString<256> OutName;
+  llvm::raw_svector_ostream Out(OutName);
+  getMangleContext().mangleCXXVBTable(RD, VBT.MangledPath, Out);
+  StringRef Name = OutName.str();
+
+  llvm::ArrayType *VBTableType =
+      llvm::ArrayType::get(CGM.IntTy, 1 + VBT.ObjectWithVPtr->getNumVBases());
+
+  assert(!CGM.getModule().getNamedGlobal(Name) &&
+         "vbtable with this name already exists: mangling bug?");
+  CharUnits Alignment =
+      CGM.getContext().getTypeAlignInChars(CGM.getContext().IntTy);
+  llvm::GlobalVariable *GV = CGM.CreateOrReplaceCXXRuntimeVariable(
+      Name, VBTableType, Linkage, Alignment.getQuantity());
+  GV->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
+
+  if (RD->hasAttr<DLLImportAttr>())
+    GV->setDLLStorageClass(llvm::GlobalValue::DLLImportStorageClass);
+  else if (RD->hasAttr<DLLExportAttr>())
+    GV->setDLLStorageClass(llvm::GlobalValue::DLLExportStorageClass);
+
+  if (!GV->hasExternalLinkage())
+    emitVBTableDefinition(VBT, RD, GV);
+
+  return GV;
+}
+
+void MicrosoftCXXABI::emitVBTableDefinition(const VPtrInfo &VBT,
+                                            const CXXRecordDecl *RD,
+                                            llvm::GlobalVariable *GV) const {
+  const CXXRecordDecl *ObjectWithVPtr = VBT.ObjectWithVPtr;
+
+  assert(RD->getNumVBases() && ObjectWithVPtr->getNumVBases() &&
+         "should only emit vbtables for classes with vbtables");
+
+  const ASTRecordLayout &BaseLayout =
+      getContext().getASTRecordLayout(VBT.IntroducingObject);
+  const ASTRecordLayout &DerivedLayout = getContext().getASTRecordLayout(RD);
+
+  SmallVector<llvm::Constant *, 4> Offsets(1 + ObjectWithVPtr->getNumVBases(),
+                                           nullptr);
+
+  // The offset from ObjectWithVPtr's vbptr to itself always leads.
+  CharUnits VBPtrOffset = BaseLayout.getVBPtrOffset();
+  Offsets[0] = llvm::ConstantInt::get(CGM.IntTy, -VBPtrOffset.getQuantity());
+
+  MicrosoftVTableContext &Context = CGM.getMicrosoftVTableContext();
+  for (const auto &I : ObjectWithVPtr->vbases()) {
+    const CXXRecordDecl *VBase = I.getType()->getAsCXXRecordDecl();
+    CharUnits Offset = DerivedLayout.getVBaseClassOffset(VBase);
+    assert(!Offset.isNegative());
+
+    // Make it relative to the subobject vbptr.
+    CharUnits CompleteVBPtrOffset = VBT.NonVirtualOffset + VBPtrOffset;
+    if (VBT.getVBaseWithVPtr())
+      CompleteVBPtrOffset +=
+          DerivedLayout.getVBaseClassOffset(VBT.getVBaseWithVPtr());
+    Offset -= CompleteVBPtrOffset;
+
+    unsigned VBIndex = Context.getVBTableIndex(ObjectWithVPtr, VBase);
+    assert(Offsets[VBIndex] == nullptr && "The same vbindex seen twice?");
+    Offsets[VBIndex] = llvm::ConstantInt::get(CGM.IntTy, Offset.getQuantity());
+  }
+
+  assert(Offsets.size() ==
+         cast<llvm::ArrayType>(cast<llvm::PointerType>(GV->getType())
+                               ->getElementType())->getNumElements());
+  llvm::ArrayType *VBTableType =
+    llvm::ArrayType::get(CGM.IntTy, Offsets.size());
+  llvm::Constant *Init = llvm::ConstantArray::get(VBTableType, Offsets);
+  GV->setInitializer(Init);
+
+  if (RD->hasAttr<DLLImportAttr>())
+    GV->setLinkage(llvm::GlobalVariable::AvailableExternallyLinkage);
+}
+
+llvm::Value *MicrosoftCXXABI::performThisAdjustment(CodeGenFunction &CGF,
+                                                    Address This,
+                                                    const ThisAdjustment &TA) {
+  if (TA.isEmpty())
+    return This.getPointer();
+
+  This = CGF.Builder.CreateElementBitCast(This, CGF.Int8Ty);
+
+  llvm::Value *V;
+  if (TA.Virtual.isEmpty()) {
+    V = This.getPointer();
+  } else {
+    assert(TA.Virtual.Microsoft.VtordispOffset < 0);
+    // Adjust the this argument based on the vtordisp value.
+    Address VtorDispPtr =
+        CGF.Builder.CreateConstInBoundsByteGEP(This,
+                 CharUnits::fromQuantity(TA.Virtual.Microsoft.VtordispOffset));
+    VtorDispPtr = CGF.Builder.CreateElementBitCast(VtorDispPtr, CGF.Int32Ty);
+    llvm::Value *VtorDisp = CGF.Builder.CreateLoad(VtorDispPtr, "vtordisp");
+    V = CGF.Builder.CreateGEP(This.getPointer(),
+                              CGF.Builder.CreateNeg(VtorDisp));
+
+    // Unfortunately, having applied the vtordisp means that we no
+    // longer really have a known alignment for the vbptr step.
+    // We'll assume the vbptr is pointer-aligned.
+
+    if (TA.Virtual.Microsoft.VBPtrOffset) {
+      // If the final overrider is defined in a virtual base other than the one
+      // that holds the vfptr, we have to use a vtordispex thunk which looks up
+      // the vbtable of the derived class.
+      assert(TA.Virtual.Microsoft.VBPtrOffset > 0);
+      assert(TA.Virtual.Microsoft.VBOffsetOffset >= 0);
+      llvm::Value *VBPtr;
+      llvm::Value *VBaseOffset =
+          GetVBaseOffsetFromVBPtr(CGF, Address(V, CGF.getPointerAlign()),
+                                  -TA.Virtual.Microsoft.VBPtrOffset,
+                                  TA.Virtual.Microsoft.VBOffsetOffset, &VBPtr);
+      V = CGF.Builder.CreateInBoundsGEP(VBPtr, VBaseOffset);
+    }
+  }
+
+  if (TA.NonVirtual) {
+    // Non-virtual adjustment might result in a pointer outside the allocated
+    // object, e.g. if the final overrider class is laid out after the virtual
+    // base that declares a method in the most derived class.
+    V = CGF.Builder.CreateConstGEP1_32(V, TA.NonVirtual);
+  }
+
+  // Don't need to bitcast back, the call CodeGen will handle this.
+  return V;
+}
+
+llvm::Value *
+MicrosoftCXXABI::performReturnAdjustment(CodeGenFunction &CGF, Address Ret,
+                                         const ReturnAdjustment &RA) {
+  if (RA.isEmpty())
+    return Ret.getPointer();
+
+  auto OrigTy = Ret.getType();
+  Ret = CGF.Builder.CreateElementBitCast(Ret, CGF.Int8Ty);
+
+  llvm::Value *V = Ret.getPointer();
+  if (RA.Virtual.Microsoft.VBIndex) {
+    assert(RA.Virtual.Microsoft.VBIndex > 0);
+    int32_t IntSize = CGF.getIntSize().getQuantity();
+    llvm::Value *VBPtr;
+    llvm::Value *VBaseOffset =
+        GetVBaseOffsetFromVBPtr(CGF, Ret, RA.Virtual.Microsoft.VBPtrOffset,
+                                IntSize * RA.Virtual.Microsoft.VBIndex, &VBPtr);
+    V = CGF.Builder.CreateInBoundsGEP(VBPtr, VBaseOffset);
+  }
+
+  if (RA.NonVirtual)
+    V = CGF.Builder.CreateConstInBoundsGEP1_32(CGF.Int8Ty, V, RA.NonVirtual);
+
+  // Cast back to the original type.
+  return CGF.Builder.CreateBitCast(V, OrigTy);
+}
+
+bool MicrosoftCXXABI::requiresArrayCookie(const CXXDeleteExpr *expr,
+                                   QualType elementType) {
+  // Microsoft seems to completely ignore the possibility of a
+  // two-argument usual deallocation function.
+  return elementType.isDestructedType();
+}
+
+bool MicrosoftCXXABI::requiresArrayCookie(const CXXNewExpr *expr) {
+  // Microsoft seems to completely ignore the possibility of a
+  // two-argument usual deallocation function.
+  return expr->getAllocatedType().isDestructedType();
+}
+
+CharUnits MicrosoftCXXABI::getArrayCookieSizeImpl(QualType type) {
+  // The array cookie is always a size_t; we then pad that out to the
+  // alignment of the element type.
+  ASTContext &Ctx = getContext();
+  return std::max(Ctx.getTypeSizeInChars(Ctx.getSizeType()),
+                  Ctx.getTypeAlignInChars(type));
+}
+
+llvm::Value *MicrosoftCXXABI::readArrayCookieImpl(CodeGenFunction &CGF,
+                                                  Address allocPtr,
+                                                  CharUnits cookieSize) {
+  Address numElementsPtr =
+    CGF.Builder.CreateElementBitCast(allocPtr, CGF.SizeTy);
+  return CGF.Builder.CreateLoad(numElementsPtr);
+}
+
+Address MicrosoftCXXABI::InitializeArrayCookie(CodeGenFunction &CGF,
+                                               Address newPtr,
+                                               llvm::Value *numElements,
+                                               const CXXNewExpr *expr,
+                                               QualType elementType) {
+  assert(requiresArrayCookie(expr));
+
+  // The size of the cookie.
+  CharUnits cookieSize = getArrayCookieSizeImpl(elementType);
+
+  // Compute an offset to the cookie.
+  Address cookiePtr = newPtr;
+
+  // Write the number of elements into the appropriate slot.
+  Address numElementsPtr
+    = CGF.Builder.CreateElementBitCast(cookiePtr, CGF.SizeTy);
+  CGF.Builder.CreateStore(numElements, numElementsPtr);
+
+  // Finally, compute a pointer to the actual data buffer by skipping
+  // over the cookie completely.
+  return CGF.Builder.CreateConstInBoundsByteGEP(newPtr, cookieSize);
+}
+
+static void emitGlobalDtorWithTLRegDtor(CodeGenFunction &CGF, const VarDecl &VD,
+                                        llvm::FunctionCallee Dtor,
+                                        llvm::Constant *Addr) {
+  // Create a function which calls the destructor.
+  llvm::Constant *DtorStub = CGF.createAtExitStub(VD, Dtor, Addr);
+
+  // extern "C" int __tlregdtor(void (*f)(void));
+  llvm::FunctionType *TLRegDtorTy = llvm::FunctionType::get(
+      CGF.IntTy, DtorStub->getType(), /*isVarArg=*/false);
+
+  llvm::FunctionCallee TLRegDtor = CGF.CGM.CreateRuntimeFunction(
+      TLRegDtorTy, "__tlregdtor", llvm::AttributeList(), /*Local=*/true);
+  if (llvm::Function *TLRegDtorFn =
+          dyn_cast<llvm::Function>(TLRegDtor.getCallee()))
+    TLRegDtorFn->setDoesNotThrow();
+
+  CGF.EmitNounwindRuntimeCall(TLRegDtor, DtorStub);
+}
+
+void MicrosoftCXXABI::registerGlobalDtor(CodeGenFunction &CGF, const VarDecl &D,
+                                         llvm::FunctionCallee Dtor,
+                                         llvm::Constant *Addr) {
+  if (D.isNoDestroy(CGM.getContext()))
+    return;
+
+  if (D.getTLSKind())
+    return emitGlobalDtorWithTLRegDtor(CGF, D, Dtor, Addr);
+
+  // The default behavior is to use atexit.
+  CGF.registerGlobalDtorWithAtExit(D, Dtor, Addr);
+}
+
+void MicrosoftCXXABI::EmitThreadLocalInitFuncs(
+    CodeGenModule &CGM, ArrayRef<const VarDecl *> CXXThreadLocals,
+    ArrayRef<llvm::Function *> CXXThreadLocalInits,
+    ArrayRef<const VarDecl *> CXXThreadLocalInitVars) {
+  if (CXXThreadLocalInits.empty())
+    return;
+
+  CGM.AppendLinkerOptions(CGM.getTarget().getTriple().getArch() ==
+                                  llvm::Triple::x86
+                              ? "/include:___dyn_tls_init@12"
+                              : "/include:__dyn_tls_init");
+
+  // This will create a GV in the .CRT$XDU section.  It will point to our
+  // initialization function.  The CRT will call all of these function
+  // pointers at start-up time and, eventually, at thread-creation time.
+  auto AddToXDU = [&CGM](llvm::Function *InitFunc) {
+    llvm::GlobalVariable *InitFuncPtr = new llvm::GlobalVariable(
+        CGM.getModule(), InitFunc->getType(), /*isConstant=*/true,
+        llvm::GlobalVariable::InternalLinkage, InitFunc,
+        Twine(InitFunc->getName(), "$initializer$"));
+    InitFuncPtr->setSection(".CRT$XDU");
+    // This variable has discardable linkage, we have to add it to @llvm.used to
+    // ensure it won't get discarded.
+    CGM.addUsedGlobal(InitFuncPtr);
+    return InitFuncPtr;
+  };
+
+  std::vector<llvm::Function *> NonComdatInits;
+  for (size_t I = 0, E = CXXThreadLocalInitVars.size(); I != E; ++I) {
+    llvm::GlobalVariable *GV = cast<llvm::GlobalVariable>(
+        CGM.GetGlobalValue(CGM.getMangledName(CXXThreadLocalInitVars[I])));
+    llvm::Function *F = CXXThreadLocalInits[I];
+
+    // If the GV is already in a comdat group, then we have to join it.
+    if (llvm::Comdat *C = GV->getComdat())
+      AddToXDU(F)->setComdat(C);
+    else
+      NonComdatInits.push_back(F);
+  }
+
+  if (!NonComdatInits.empty()) {
+    llvm::FunctionType *FTy =
+        llvm::FunctionType::get(CGM.VoidTy, /*isVarArg=*/false);
+    llvm::Function *InitFunc = CGM.CreateGlobalInitOrDestructFunction(
+        FTy, "__tls_init", CGM.getTypes().arrangeNullaryFunction(),
+        SourceLocation(), /*TLS=*/true);
+    CodeGenFunction(CGM).GenerateCXXGlobalInitFunc(InitFunc, NonComdatInits);
+
+    AddToXDU(InitFunc);
+  }
+}
+
+LValue MicrosoftCXXABI::EmitThreadLocalVarDeclLValue(CodeGenFunction &CGF,
+                                                     const VarDecl *VD,
+                                                     QualType LValType) {
+  CGF.CGM.ErrorUnsupported(VD, "thread wrappers");
+  return LValue();
+}
+
+static ConstantAddress getInitThreadEpochPtr(CodeGenModule &CGM) {
+  StringRef VarName("_Init_thread_epoch");
+  CharUnits Align = CGM.getIntAlign();
+  if (auto *GV = CGM.getModule().getNamedGlobal(VarName))
+    return ConstantAddress(GV, Align);
+  auto *GV = new llvm::GlobalVariable(
+      CGM.getModule(), CGM.IntTy,
+      /*isConstant=*/false, llvm::GlobalVariable::ExternalLinkage,
+      /*Initializer=*/nullptr, VarName,
+      /*InsertBefore=*/nullptr, llvm::GlobalVariable::GeneralDynamicTLSModel);
+  GV->setAlignment(Align.getAsAlign());
+  return ConstantAddress(GV, Align);
+}
+
+static llvm::FunctionCallee getInitThreadHeaderFn(CodeGenModule &CGM) {
+  llvm::FunctionType *FTy =
+      llvm::FunctionType::get(llvm::Type::getVoidTy(CGM.getLLVMContext()),
+                              CGM.IntTy->getPointerTo(), /*isVarArg=*/false);
+  return CGM.CreateRuntimeFunction(
+      FTy, "_Init_thread_header",
+      llvm::AttributeList::get(CGM.getLLVMContext(),
+                               llvm::AttributeList::FunctionIndex,
+                               llvm::Attribute::NoUnwind),
+      /*Local=*/true);
+}
+
+static llvm::FunctionCallee getInitThreadFooterFn(CodeGenModule &CGM) {
+  llvm::FunctionType *FTy =
+      llvm::FunctionType::get(llvm::Type::getVoidTy(CGM.getLLVMContext()),
+                              CGM.IntTy->getPointerTo(), /*isVarArg=*/false);
+  return CGM.CreateRuntimeFunction(
+      FTy, "_Init_thread_footer",
+      llvm::AttributeList::get(CGM.getLLVMContext(),
+                               llvm::AttributeList::FunctionIndex,
+                               llvm::Attribute::NoUnwind),
+      /*Local=*/true);
+}
+
+static llvm::FunctionCallee getInitThreadAbortFn(CodeGenModule &CGM) {
+  llvm::FunctionType *FTy =
+      llvm::FunctionType::get(llvm::Type::getVoidTy(CGM.getLLVMContext()),
+                              CGM.IntTy->getPointerTo(), /*isVarArg=*/false);
+  return CGM.CreateRuntimeFunction(
+      FTy, "_Init_thread_abort",
+      llvm::AttributeList::get(CGM.getLLVMContext(),
+                               llvm::AttributeList::FunctionIndex,
+                               llvm::Attribute::NoUnwind),
+      /*Local=*/true);
+}
+
+namespace {
+struct ResetGuardBit final : EHScopeStack::Cleanup {
+  Address Guard;
+  unsigned GuardNum;
+  ResetGuardBit(Address Guard, unsigned GuardNum)
+      : Guard(Guard), GuardNum(GuardNum) {}
+
+  void Emit(CodeGenFunction &CGF, Flags flags) override {
+    // Reset the bit in the mask so that the static variable may be
+    // reinitialized.
+    CGBuilderTy &Builder = CGF.Builder;
+    llvm::LoadInst *LI = Builder.CreateLoad(Guard);
+    llvm::ConstantInt *Mask =
+        llvm::ConstantInt::get(CGF.IntTy, ~(1ULL << GuardNum));
+    Builder.CreateStore(Builder.CreateAnd(LI, Mask), Guard);
+  }
+};
+
+struct CallInitThreadAbort final : EHScopeStack::Cleanup {
+  llvm::Value *Guard;
+  CallInitThreadAbort(Address Guard) : Guard(Guard.getPointer()) {}
+
+  void Emit(CodeGenFunction &CGF, Flags flags) override {
+    // Calling _Init_thread_abort will reset the guard's state.
+    CGF.EmitNounwindRuntimeCall(getInitThreadAbortFn(CGF.CGM), Guard);
+  }
+};
+}
+
+void MicrosoftCXXABI::EmitGuardedInit(CodeGenFunction &CGF, const VarDecl &D,
+                                      llvm::GlobalVariable *GV,
+                                      bool PerformInit) {
+  // MSVC only uses guards for static locals.
+  if (!D.isStaticLocal()) {
+    assert(GV->hasWeakLinkage() || GV->hasLinkOnceLinkage());
+    // GlobalOpt is allowed to discard the initializer, so use linkonce_odr.
+    llvm::Function *F = CGF.CurFn;
+    F->setLinkage(llvm::GlobalValue::LinkOnceODRLinkage);
+    F->setComdat(CGM.getModule().getOrInsertComdat(F->getName()));
+    CGF.EmitCXXGlobalVarDeclInit(D, GV, PerformInit);
+    return;
+  }
+
+  bool ThreadlocalStatic = D.getTLSKind();
+  bool ThreadsafeStatic = getContext().getLangOpts().ThreadsafeStatics;
+
+  // Thread-safe static variables which aren't thread-specific have a
+  // per-variable guard.
+  bool HasPerVariableGuard = ThreadsafeStatic && !ThreadlocalStatic;
+
+  CGBuilderTy &Builder = CGF.Builder;
+  llvm::IntegerType *GuardTy = CGF.Int32Ty;
+  llvm::ConstantInt *Zero = llvm::ConstantInt::get(GuardTy, 0);
+  CharUnits GuardAlign = CharUnits::fromQuantity(4);
+
+  // Get the guard variable for this function if we have one already.
+  GuardInfo *GI = nullptr;
+  if (ThreadlocalStatic)
+    GI = &ThreadLocalGuardVariableMap[D.getDeclContext()];
+  else if (!ThreadsafeStatic)
+    GI = &GuardVariableMap[D.getDeclContext()];
+
+  llvm::GlobalVariable *GuardVar = GI ? GI->Guard : nullptr;
+  unsigned GuardNum;
+  if (D.isExternallyVisible()) {
+    // Externally visible variables have to be numbered in Sema to properly
+    // handle unreachable VarDecls.
+    GuardNum = getContext().getStaticLocalNumber(&D);
+    assert(GuardNum > 0);
+    GuardNum--;
+  } else if (HasPerVariableGuard) {
+    GuardNum = ThreadSafeGuardNumMap[D.getDeclContext()]++;
+  } else {
+    // Non-externally visible variables are numbered here in CodeGen.
+    GuardNum = GI->BitIndex++;
+  }
+
+  if (!HasPerVariableGuard && GuardNum >= 32) {
+    if (D.isExternallyVisible())
+      ErrorUnsupportedABI(CGF, "more than 32 guarded initializations");
+    GuardNum %= 32;
+    GuardVar = nullptr;
+  }
+
+  if (!GuardVar) {
+    // Mangle the name for the guard.
+    SmallString<256> GuardName;
+    {
+      llvm::raw_svector_ostream Out(GuardName);
+      if (HasPerVariableGuard)
+        getMangleContext().mangleThreadSafeStaticGuardVariable(&D, GuardNum,
+                                                               Out);
+      else
+        getMangleContext().mangleStaticGuardVariable(&D, Out);
+    }
+
+    // Create the guard variable with a zero-initializer. Just absorb linkage,
+    // visibility and dll storage class from the guarded variable.
+    GuardVar =
+        new llvm::GlobalVariable(CGM.getModule(), GuardTy, /*isConstant=*/false,
+                                 GV->getLinkage(), Zero, GuardName.str());
+    GuardVar->setVisibility(GV->getVisibility());
+    GuardVar->setDLLStorageClass(GV->getDLLStorageClass());
+    GuardVar->setAlignment(GuardAlign.getAsAlign());
+    if (GuardVar->isWeakForLinker())
+      GuardVar->setComdat(
+          CGM.getModule().getOrInsertComdat(GuardVar->getName()));
+    if (D.getTLSKind())
+      GuardVar->setThreadLocal(true);
+    if (GI && !HasPerVariableGuard)
+      GI->Guard = GuardVar;
+  }
+
+  ConstantAddress GuardAddr(GuardVar, GuardAlign);
+
+  assert(GuardVar->getLinkage() == GV->getLinkage() &&
+         "static local from the same function had different linkage");
+
+  if (!HasPerVariableGuard) {
+    // Pseudo code for the test:
+    // if (!(GuardVar & MyGuardBit)) {
+    //   GuardVar |= MyGuardBit;
+    //   ... initialize the object ...;
+    // }
+
+    // Test our bit from the guard variable.
+    llvm::ConstantInt *Bit = llvm::ConstantInt::get(GuardTy, 1ULL << GuardNum);
+    llvm::LoadInst *LI = Builder.CreateLoad(GuardAddr);
+    llvm::Value *NeedsInit =
+        Builder.CreateICmpEQ(Builder.CreateAnd(LI, Bit), Zero);
+    llvm::BasicBlock *InitBlock = CGF.createBasicBlock("init");
+    llvm::BasicBlock *EndBlock = CGF.createBasicBlock("init.end");
+    CGF.EmitCXXGuardedInitBranch(NeedsInit, InitBlock, EndBlock,
+                                 CodeGenFunction::GuardKind::VariableGuard, &D);
+
+    // Set our bit in the guard variable and emit the initializer and add a global
+    // destructor if appropriate.
+    CGF.EmitBlock(InitBlock);
+    Builder.CreateStore(Builder.CreateOr(LI, Bit), GuardAddr);
+    CGF.EHStack.pushCleanup<ResetGuardBit>(EHCleanup, GuardAddr, GuardNum);
+    CGF.EmitCXXGlobalVarDeclInit(D, GV, PerformInit);
+    CGF.PopCleanupBlock();
+    Builder.CreateBr(EndBlock);
+
+    // Continue.
+    CGF.EmitBlock(EndBlock);
+  } else {
+    // Pseudo code for the test:
+    // if (TSS > _Init_thread_epoch) {
+    //   _Init_thread_header(&TSS);
+    //   if (TSS == -1) {
+    //     ... initialize the object ...;
+    //     _Init_thread_footer(&TSS);
+    //   }
+    // }
+    //
+    // The algorithm is almost identical to what can be found in the appendix
+    // found in N2325.
+
+    // This BasicBLock determines whether or not we have any work to do.
+    llvm::LoadInst *FirstGuardLoad = Builder.CreateLoad(GuardAddr);
+    FirstGuardLoad->setOrdering(llvm::AtomicOrdering::Unordered);
+    llvm::LoadInst *InitThreadEpoch =
+        Builder.CreateLoad(getInitThreadEpochPtr(CGM));
+    llvm::Value *IsUninitialized =
+        Builder.CreateICmpSGT(FirstGuardLoad, InitThreadEpoch);
+    llvm::BasicBlock *AttemptInitBlock = CGF.createBasicBlock("init.attempt");
+    llvm::BasicBlock *EndBlock = CGF.createBasicBlock("init.end");
+    CGF.EmitCXXGuardedInitBranch(IsUninitialized, AttemptInitBlock, EndBlock,
+                                 CodeGenFunction::GuardKind::VariableGuard, &D);
+
+    // This BasicBlock attempts to determine whether or not this thread is
+    // responsible for doing the initialization.
+    CGF.EmitBlock(AttemptInitBlock);
+    CGF.EmitNounwindRuntimeCall(getInitThreadHeaderFn(CGM),
+                                GuardAddr.getPointer());
+    llvm::LoadInst *SecondGuardLoad = Builder.CreateLoad(GuardAddr);
+    SecondGuardLoad->setOrdering(llvm::AtomicOrdering::Unordered);
+    llvm::Value *ShouldDoInit =
+        Builder.CreateICmpEQ(SecondGuardLoad, getAllOnesInt());
+    llvm::BasicBlock *InitBlock = CGF.createBasicBlock("init");
+    Builder.CreateCondBr(ShouldDoInit, InitBlock, EndBlock);
+
+    // Ok, we ended up getting selected as the initializing thread.
+    CGF.EmitBlock(InitBlock);
+    CGF.EHStack.pushCleanup<CallInitThreadAbort>(EHCleanup, GuardAddr);
+    CGF.EmitCXXGlobalVarDeclInit(D, GV, PerformInit);
+    CGF.PopCleanupBlock();
+    CGF.EmitNounwindRuntimeCall(getInitThreadFooterFn(CGM),
+                                GuardAddr.getPointer());
+    Builder.CreateBr(EndBlock);
+
+    CGF.EmitBlock(EndBlock);
+  }
+}
+
+bool MicrosoftCXXABI::isZeroInitializable(const MemberPointerType *MPT) {
+  // Null-ness for function memptrs only depends on the first field, which is
+  // the function pointer.  The rest don't matter, so we can zero initialize.
+  if (MPT->isMemberFunctionPointer())
+    return true;
+
+  // The virtual base adjustment field is always -1 for null, so if we have one
+  // we can't zero initialize.  The field offset is sometimes also -1 if 0 is a
+  // valid field offset.
+  const CXXRecordDecl *RD = MPT->getMostRecentCXXRecordDecl();
+  MSInheritanceModel Inheritance = RD->getMSInheritanceModel();
+  return (!inheritanceModelHasVBTableOffsetField(Inheritance) &&
+          RD->nullFieldOffsetIsZero());
+}
+
+llvm::Type *
+MicrosoftCXXABI::ConvertMemberPointerType(const MemberPointerType *MPT) {
+  const CXXRecordDecl *RD = MPT->getMostRecentCXXRecordDecl();
+  MSInheritanceModel Inheritance = RD->getMSInheritanceModel();
+  llvm::SmallVector<llvm::Type *, 4> fields;
+  if (MPT->isMemberFunctionPointer())
+    fields.push_back(CGM.VoidPtrTy);  // FunctionPointerOrVirtualThunk
+  else
+    fields.push_back(CGM.IntTy);  // FieldOffset
+
+  if (inheritanceModelHasNVOffsetField(MPT->isMemberFunctionPointer(),
+                                       Inheritance))
+    fields.push_back(CGM.IntTy);
+  if (inheritanceModelHasVBPtrOffsetField(Inheritance))
+    fields.push_back(CGM.IntTy);
+  if (inheritanceModelHasVBTableOffsetField(Inheritance))
+    fields.push_back(CGM.IntTy);  // VirtualBaseAdjustmentOffset
+
+  if (fields.size() == 1)
+    return fields[0];
+  return llvm::StructType::get(CGM.getLLVMContext(), fields);
+}
+
+void MicrosoftCXXABI::
+GetNullMemberPointerFields(const MemberPointerType *MPT,
+                           llvm::SmallVectorImpl<llvm::Constant *> &fields) {
+  assert(fields.empty());
+  const CXXRecordDecl *RD = MPT->getMostRecentCXXRecordDecl();
+  MSInheritanceModel Inheritance = RD->getMSInheritanceModel();
+  if (MPT->isMemberFunctionPointer()) {
+    // FunctionPointerOrVirtualThunk
+    fields.push_back(llvm::Constant::getNullValue(CGM.VoidPtrTy));
+  } else {
+    if (RD->nullFieldOffsetIsZero())
+      fields.push_back(getZeroInt());  // FieldOffset
+    else
+      fields.push_back(getAllOnesInt());  // FieldOffset
+  }
+
+  if (inheritanceModelHasNVOffsetField(MPT->isMemberFunctionPointer(),
+                                       Inheritance))
+    fields.push_back(getZeroInt());
+  if (inheritanceModelHasVBPtrOffsetField(Inheritance))
+    fields.push_back(getZeroInt());
+  if (inheritanceModelHasVBTableOffsetField(Inheritance))
+    fields.push_back(getAllOnesInt());
+}
+
+llvm::Constant *
+MicrosoftCXXABI::EmitNullMemberPointer(const MemberPointerType *MPT) {
+  llvm::SmallVector<llvm::Constant *, 4> fields;
+  GetNullMemberPointerFields(MPT, fields);
+  if (fields.size() == 1)
+    return fields[0];
+  llvm::Constant *Res = llvm::ConstantStruct::getAnon(fields);
+  assert(Res->getType() == ConvertMemberPointerType(MPT));
+  return Res;
+}
+
+llvm::Constant *
+MicrosoftCXXABI::EmitFullMemberPointer(llvm::Constant *FirstField,
+                                       bool IsMemberFunction,
+                                       const CXXRecordDecl *RD,
+                                       CharUnits NonVirtualBaseAdjustment,
+                                       unsigned VBTableIndex) {
+  MSInheritanceModel Inheritance = RD->getMSInheritanceModel();
+
+  // Single inheritance class member pointer are represented as scalars instead
+  // of aggregates.
+  if (inheritanceModelHasOnlyOneField(IsMemberFunction, Inheritance))
+    return FirstField;
+
+  llvm::SmallVector<llvm::Constant *, 4> fields;
+  fields.push_back(FirstField);
+
+  if (inheritanceModelHasNVOffsetField(IsMemberFunction, Inheritance))
+    fields.push_back(llvm::ConstantInt::get(
+      CGM.IntTy, NonVirtualBaseAdjustment.getQuantity()));
+
+  if (inheritanceModelHasVBPtrOffsetField(Inheritance)) {
+    CharUnits Offs = CharUnits::Zero();
+    if (VBTableIndex)
+      Offs = getContext().getASTRecordLayout(RD).getVBPtrOffset();
+    fields.push_back(llvm::ConstantInt::get(CGM.IntTy, Offs.getQuantity()));
+  }
+
+  // The rest of the fields are adjusted by conversions to a more derived class.
+  if (inheritanceModelHasVBTableOffsetField(Inheritance))
+    fields.push_back(llvm::ConstantInt::get(CGM.IntTy, VBTableIndex));
+
+  return llvm::ConstantStruct::getAnon(fields);
+}
+
+llvm::Constant *
+MicrosoftCXXABI::EmitMemberDataPointer(const MemberPointerType *MPT,
+                                       CharUnits offset) {
+  return EmitMemberDataPointer(MPT->getMostRecentCXXRecordDecl(), offset);
+}
+
+llvm::Constant *MicrosoftCXXABI::EmitMemberDataPointer(const CXXRecordDecl *RD,
+                                                       CharUnits offset) {
+  if (RD->getMSInheritanceModel() ==
+      MSInheritanceModel::Virtual)
+    offset -= getContext().getOffsetOfBaseWithVBPtr(RD);
+  llvm::Constant *FirstField =
+    llvm::ConstantInt::get(CGM.IntTy, offset.getQuantity());
+  return EmitFullMemberPointer(FirstField, /*IsMemberFunction=*/false, RD,
+                               CharUnits::Zero(), /*VBTableIndex=*/0);
+}
+
+llvm::Constant *MicrosoftCXXABI::EmitMemberPointer(const APValue &MP,
+                                                   QualType MPType) {
+  const MemberPointerType *DstTy = MPType->castAs<MemberPointerType>();
+  const ValueDecl *MPD = MP.getMemberPointerDecl();
+  if (!MPD)
+    return EmitNullMemberPointer(DstTy);
+
+  ASTContext &Ctx = getContext();
+  ArrayRef<const CXXRecordDecl *> MemberPointerPath = MP.getMemberPointerPath();
+
+  llvm::Constant *C;
+  if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(MPD)) {
+    C = EmitMemberFunctionPointer(MD);
+  } else {
+    // For a pointer to data member, start off with the offset of the field in
+    // the class in which it was declared, and convert from there if necessary.
+    // For indirect field decls, get the outermost anonymous field and use the
+    // parent class.
+    CharUnits FieldOffset = Ctx.toCharUnitsFromBits(Ctx.getFieldOffset(MPD));
+    const FieldDecl *FD = dyn_cast<FieldDecl>(MPD);
+    if (!FD)
+      FD = cast<FieldDecl>(*cast<IndirectFieldDecl>(MPD)->chain_begin());
+    const CXXRecordDecl *RD = cast<CXXRecordDecl>(FD->getParent());
+    RD = RD->getMostRecentNonInjectedDecl();
+    C = EmitMemberDataPointer(RD, FieldOffset);
+  }
+
+  if (!MemberPointerPath.empty()) {
+    const CXXRecordDecl *SrcRD = cast<CXXRecordDecl>(MPD->getDeclContext());
+    const Type *SrcRecTy = Ctx.getTypeDeclType(SrcRD).getTypePtr();
+    const MemberPointerType *SrcTy =
+        Ctx.getMemberPointerType(DstTy->getPointeeType(), SrcRecTy)
+            ->castAs<MemberPointerType>();
+
+    bool DerivedMember = MP.isMemberPointerToDerivedMember();
+    SmallVector<const CXXBaseSpecifier *, 4> DerivedToBasePath;
+    const CXXRecordDecl *PrevRD = SrcRD;
+    for (const CXXRecordDecl *PathElem : MemberPointerPath) {
+      const CXXRecordDecl *Base = nullptr;
+      const CXXRecordDecl *Derived = nullptr;
+      if (DerivedMember) {
+        Base = PathElem;
+        Derived = PrevRD;
+      } else {
+        Base = PrevRD;
+        Derived = PathElem;
+      }
+      for (const CXXBaseSpecifier &BS : Derived->bases())
+        if (BS.getType()->getAsCXXRecordDecl()->getCanonicalDecl() ==
+            Base->getCanonicalDecl())
+          DerivedToBasePath.push_back(&BS);
+      PrevRD = PathElem;
+    }
+    assert(DerivedToBasePath.size() == MemberPointerPath.size());
+
+    CastKind CK = DerivedMember ? CK_DerivedToBaseMemberPointer
+                                : CK_BaseToDerivedMemberPointer;
+    C = EmitMemberPointerConversion(SrcTy, DstTy, CK, DerivedToBasePath.begin(),
+                                    DerivedToBasePath.end(), C);
+  }
+  return C;
+}
+
+llvm::Constant *
+MicrosoftCXXABI::EmitMemberFunctionPointer(const CXXMethodDecl *MD) {
+  assert(MD->isInstance() && "Member function must not be static!");
+
+  CharUnits NonVirtualBaseAdjustment = CharUnits::Zero();
+  const CXXRecordDecl *RD = MD->getParent()->getMostRecentNonInjectedDecl();
+  CodeGenTypes &Types = CGM.getTypes();
+
+  unsigned VBTableIndex = 0;
+  llvm::Constant *FirstField;
+  const FunctionProtoType *FPT = MD->getType()->castAs<FunctionProtoType>();
+  if (!MD->isVirtual()) {
+    llvm::Type *Ty;
+    // Check whether the function has a computable LLVM signature.
+    if (Types.isFuncTypeConvertible(FPT)) {
+      // The function has a computable LLVM signature; use the correct type.
+      Ty = Types.GetFunctionType(Types.arrangeCXXMethodDeclaration(MD));
+    } else {
+      // Use an arbitrary non-function type to tell GetAddrOfFunction that the
+      // function type is incomplete.
+      Ty = CGM.PtrDiffTy;
+    }
+    FirstField = CGM.GetAddrOfFunction(MD, Ty);
+  } else {
+    auto &VTableContext = CGM.getMicrosoftVTableContext();
+    MethodVFTableLocation ML = VTableContext.getMethodVFTableLocation(MD);
+    FirstField = EmitVirtualMemPtrThunk(MD, ML);
+    // Include the vfptr adjustment if the method is in a non-primary vftable.
+    NonVirtualBaseAdjustment += ML.VFPtrOffset;
+    if (ML.VBase)
+      VBTableIndex = VTableContext.getVBTableIndex(RD, ML.VBase) * 4;
+  }
+
+  if (VBTableIndex == 0 &&
+      RD->getMSInheritanceModel() ==
+          MSInheritanceModel::Virtual)
+    NonVirtualBaseAdjustment -= getContext().getOffsetOfBaseWithVBPtr(RD);
+
+  // The rest of the fields are common with data member pointers.
+  FirstField = llvm::ConstantExpr::getBitCast(FirstField, CGM.VoidPtrTy);
+  return EmitFullMemberPointer(FirstField, /*IsMemberFunction=*/true, RD,
+                               NonVirtualBaseAdjustment, VBTableIndex);
+}
+
+/// Member pointers are the same if they're either bitwise identical *or* both
+/// null.  Null-ness for function members is determined by the first field,
+/// while for data member pointers we must compare all fields.
+llvm::Value *
+MicrosoftCXXABI::EmitMemberPointerComparison(CodeGenFunction &CGF,
+                                             llvm::Value *L,
+                                             llvm::Value *R,
+                                             const MemberPointerType *MPT,
+                                             bool Inequality) {
+  CGBuilderTy &Builder = CGF.Builder;
+
+  // Handle != comparisons by switching the sense of all boolean operations.
+  llvm::ICmpInst::Predicate Eq;
+  llvm::Instruction::BinaryOps And, Or;
+  if (Inequality) {
+    Eq = llvm::ICmpInst::ICMP_NE;
+    And = llvm::Instruction::Or;
+    Or = llvm::Instruction::And;
+  } else {
+    Eq = llvm::ICmpInst::ICMP_EQ;
+    And = llvm::Instruction::And;
+    Or = llvm::Instruction::Or;
+  }
+
+  // If this is a single field member pointer (single inheritance), this is a
+  // single icmp.
+  const CXXRecordDecl *RD = MPT->getMostRecentCXXRecordDecl();
+  MSInheritanceModel Inheritance = RD->getMSInheritanceModel();
+  if (inheritanceModelHasOnlyOneField(MPT->isMemberFunctionPointer(),
+                                      Inheritance))
+    return Builder.CreateICmp(Eq, L, R);
+
+  // Compare the first field.
+  llvm::Value *L0 = Builder.CreateExtractValue(L, 0, "lhs.0");
+  llvm::Value *R0 = Builder.CreateExtractValue(R, 0, "rhs.0");
+  llvm::Value *Cmp0 = Builder.CreateICmp(Eq, L0, R0, "memptr.cmp.first");
+
+  // Compare everything other than the first field.
+  llvm::Value *Res = nullptr;
+  llvm::StructType *LType = cast<llvm::StructType>(L->getType());
+  for (unsigned I = 1, E = LType->getNumElements(); I != E; ++I) {
+    llvm::Value *LF = Builder.CreateExtractValue(L, I);
+    llvm::Value *RF = Builder.CreateExtractValue(R, I);
+    llvm::Value *Cmp = Builder.CreateICmp(Eq, LF, RF, "memptr.cmp.rest");
+    if (Res)
+      Res = Builder.CreateBinOp(And, Res, Cmp);
+    else
+      Res = Cmp;
+  }
+
+  // Check if the first field is 0 if this is a function pointer.
+  if (MPT->isMemberFunctionPointer()) {
+    // (l1 == r1 && ...) || l0 == 0
+    llvm::Value *Zero = llvm::Constant::getNullValue(L0->getType());
+    llvm::Value *IsZero = Builder.CreateICmp(Eq, L0, Zero, "memptr.cmp.iszero");
+    Res = Builder.CreateBinOp(Or, Res, IsZero);
+  }
+
+  // Combine the comparison of the first field, which must always be true for
+  // this comparison to succeeed.
+  return Builder.CreateBinOp(And, Res, Cmp0, "memptr.cmp");
+}
+
+llvm::Value *
+MicrosoftCXXABI::EmitMemberPointerIsNotNull(CodeGenFunction &CGF,
+                                            llvm::Value *MemPtr,
+                                            const MemberPointerType *MPT) {
+  CGBuilderTy &Builder = CGF.Builder;
+  llvm::SmallVector<llvm::Constant *, 4> fields;
+  // We only need one field for member functions.
+  if (MPT->isMemberFunctionPointer())
+    fields.push_back(llvm::Constant::getNullValue(CGM.VoidPtrTy));
+  else
+    GetNullMemberPointerFields(MPT, fields);
+  assert(!fields.empty());
+  llvm::Value *FirstField = MemPtr;
+  if (MemPtr->getType()->isStructTy())
+    FirstField = Builder.CreateExtractValue(MemPtr, 0);
+  llvm::Value *Res = Builder.CreateICmpNE(FirstField, fields[0], "memptr.cmp0");
+
+  // For function member pointers, we only need to test the function pointer
+  // field.  The other fields if any can be garbage.
+  if (MPT->isMemberFunctionPointer())
+    return Res;
+
+  // Otherwise, emit a series of compares and combine the results.
+  for (int I = 1, E = fields.size(); I < E; ++I) {
+    llvm::Value *Field = Builder.CreateExtractValue(MemPtr, I);
+    llvm::Value *Next = Builder.CreateICmpNE(Field, fields[I], "memptr.cmp");
+    Res = Builder.CreateOr(Res, Next, "memptr.tobool");
+  }
+  return Res;
+}
+
+bool MicrosoftCXXABI::MemberPointerConstantIsNull(const MemberPointerType *MPT,
+                                                  llvm::Constant *Val) {
+  // Function pointers are null if the pointer in the first field is null.
+  if (MPT->isMemberFunctionPointer()) {
+    llvm::Constant *FirstField = Val->getType()->isStructTy() ?
+      Val->getAggregateElement(0U) : Val;
+    return FirstField->isNullValue();
+  }
+
+  // If it's not a function pointer and it's zero initializable, we can easily
+  // check zero.
+  if (isZeroInitializable(MPT) && Val->isNullValue())
+    return true;
+
+  // Otherwise, break down all the fields for comparison.  Hopefully these
+  // little Constants are reused, while a big null struct might not be.
+  llvm::SmallVector<llvm::Constant *, 4> Fields;
+  GetNullMemberPointerFields(MPT, Fields);
+  if (Fields.size() == 1) {
+    assert(Val->getType()->isIntegerTy());
+    return Val == Fields[0];
+  }
+
+  unsigned I, E;
+  for (I = 0, E = Fields.size(); I != E; ++I) {
+    if (Val->getAggregateElement(I) != Fields[I])
+      break;
+  }
+  return I == E;
+}
+
+llvm::Value *
+MicrosoftCXXABI::GetVBaseOffsetFromVBPtr(CodeGenFunction &CGF,
+                                         Address This,
+                                         llvm::Value *VBPtrOffset,
+                                         llvm::Value *VBTableOffset,
+                                         llvm::Value **VBPtrOut) {
+  CGBuilderTy &Builder = CGF.Builder;
+  // Load the vbtable pointer from the vbptr in the instance.
+  This = Builder.CreateElementBitCast(This, CGM.Int8Ty);
+  llvm::Value *VBPtr =
+    Builder.CreateInBoundsGEP(This.getPointer(), VBPtrOffset, "vbptr");
+  if (VBPtrOut) *VBPtrOut = VBPtr;
+  VBPtr = Builder.CreateBitCast(VBPtr,
+            CGM.Int32Ty->getPointerTo(0)->getPointerTo(This.getAddressSpace()));
+
+  CharUnits VBPtrAlign;
+  if (auto CI = dyn_cast<llvm::ConstantInt>(VBPtrOffset)) {
+    VBPtrAlign = This.getAlignment().alignmentAtOffset(
+                                   CharUnits::fromQuantity(CI->getSExtValue()));
+  } else {
+    VBPtrAlign = CGF.getPointerAlign();
+  }
+
+  llvm::Value *VBTable = Builder.CreateAlignedLoad(VBPtr, VBPtrAlign, "vbtable");
+
+  // Translate from byte offset to table index. It improves analyzability.
+  llvm::Value *VBTableIndex = Builder.CreateAShr(
+      VBTableOffset, llvm::ConstantInt::get(VBTableOffset->getType(), 2),
+      "vbtindex", /*isExact=*/true);
+
+  // Load an i32 offset from the vb-table.
+  llvm::Value *VBaseOffs = Builder.CreateInBoundsGEP(VBTable, VBTableIndex);
+  VBaseOffs = Builder.CreateBitCast(VBaseOffs, CGM.Int32Ty->getPointerTo(0));
+  return Builder.CreateAlignedLoad(VBaseOffs, CharUnits::fromQuantity(4),
+                                   "vbase_offs");
+}
+
+// Returns an adjusted base cast to i8*, since we do more address arithmetic on
+// it.
+llvm::Value *MicrosoftCXXABI::AdjustVirtualBase(
+    CodeGenFunction &CGF, const Expr *E, const CXXRecordDecl *RD,
+    Address Base, llvm::Value *VBTableOffset, llvm::Value *VBPtrOffset) {
+  CGBuilderTy &Builder = CGF.Builder;
+  Base = Builder.CreateElementBitCast(Base, CGM.Int8Ty);
+  llvm::BasicBlock *OriginalBB = nullptr;
+  llvm::BasicBlock *SkipAdjustBB = nullptr;
+  llvm::BasicBlock *VBaseAdjustBB = nullptr;
+
+  // In the unspecified inheritance model, there might not be a vbtable at all,
+  // in which case we need to skip the virtual base lookup.  If there is a
+  // vbtable, the first entry is a no-op entry that gives back the original
+  // base, so look for a virtual base adjustment offset of zero.
+  if (VBPtrOffset) {
+    OriginalBB = Builder.GetInsertBlock();
+    VBaseAdjustBB = CGF.createBasicBlock("memptr.vadjust");
+    SkipAdjustBB = CGF.createBasicBlock("memptr.skip_vadjust");
+    llvm::Value *IsVirtual =
+      Builder.CreateICmpNE(VBTableOffset, getZeroInt(),
+                           "memptr.is_vbase");
+    Builder.CreateCondBr(IsVirtual, VBaseAdjustBB, SkipAdjustBB);
+    CGF.EmitBlock(VBaseAdjustBB);
+  }
+
+  // If we weren't given a dynamic vbptr offset, RD should be complete and we'll
+  // know the vbptr offset.
+  if (!VBPtrOffset) {
+    CharUnits offs = CharUnits::Zero();
+    if (!RD->hasDefinition()) {
+      DiagnosticsEngine &Diags = CGF.CGM.getDiags();
+      unsigned DiagID = Diags.getCustomDiagID(
+          DiagnosticsEngine::Error,
+          "member pointer representation requires a "
+          "complete class type for %0 to perform this expression");
+      Diags.Report(E->getExprLoc(), DiagID) << RD << E->getSourceRange();
+    } else if (RD->getNumVBases())
+      offs = getContext().getASTRecordLayout(RD).getVBPtrOffset();
+    VBPtrOffset = llvm::ConstantInt::get(CGM.IntTy, offs.getQuantity());
+  }
+  llvm::Value *VBPtr = nullptr;
+  llvm::Value *VBaseOffs =
+    GetVBaseOffsetFromVBPtr(CGF, Base, VBPtrOffset, VBTableOffset, &VBPtr);
+  llvm::Value *AdjustedBase = Builder.CreateInBoundsGEP(VBPtr, VBaseOffs);
+
+  // Merge control flow with the case where we didn't have to adjust.
+  if (VBaseAdjustBB) {
+    Builder.CreateBr(SkipAdjustBB);
+    CGF.EmitBlock(SkipAdjustBB);
+    llvm::PHINode *Phi = Builder.CreatePHI(CGM.Int8PtrTy, 2, "memptr.base");
+    Phi->addIncoming(Base.getPointer(), OriginalBB);
+    Phi->addIncoming(AdjustedBase, VBaseAdjustBB);
+    return Phi;
+  }
+  return AdjustedBase;
+}
+
+llvm::Value *MicrosoftCXXABI::EmitMemberDataPointerAddress(
+    CodeGenFunction &CGF, const Expr *E, Address Base, llvm::Value *MemPtr,
+    const MemberPointerType *MPT) {
+  assert(MPT->isMemberDataPointer());
+  unsigned AS = Base.getAddressSpace();
+  llvm::Type *PType =
+      CGF.ConvertTypeForMem(MPT->getPointeeType())->getPointerTo(AS);
+  CGBuilderTy &Builder = CGF.Builder;
+  const CXXRecordDecl *RD = MPT->getMostRecentCXXRecordDecl();
+  MSInheritanceModel Inheritance = RD->getMSInheritanceModel();
+
+  // Extract the fields we need, regardless of model.  We'll apply them if we
+  // have them.
+  llvm::Value *FieldOffset = MemPtr;
+  llvm::Value *VirtualBaseAdjustmentOffset = nullptr;
+  llvm::Value *VBPtrOffset = nullptr;
+  if (MemPtr->getType()->isStructTy()) {
+    // We need to extract values.
+    unsigned I = 0;
+    FieldOffset = Builder.CreateExtractValue(MemPtr, I++);
+    if (inheritanceModelHasVBPtrOffsetField(Inheritance))
+      VBPtrOffset = Builder.CreateExtractValue(MemPtr, I++);
+    if (inheritanceModelHasVBTableOffsetField(Inheritance))
+      VirtualBaseAdjustmentOffset = Builder.CreateExtractValue(MemPtr, I++);
+  }
+
+  llvm::Value *Addr;
+  if (VirtualBaseAdjustmentOffset) {
+    Addr = AdjustVirtualBase(CGF, E, RD, Base, VirtualBaseAdjustmentOffset,
+                             VBPtrOffset);
+  } else {
+    Addr = Base.getPointer();
+  }
+
+  // Cast to char*.
+  Addr = Builder.CreateBitCast(Addr, CGF.Int8Ty->getPointerTo(AS));
+
+  // Apply the offset, which we assume is non-null.
+  Addr = Builder.CreateInBoundsGEP(Addr, FieldOffset, "memptr.offset");
+
+  // Cast the address to the appropriate pointer type, adopting the address
+  // space of the base pointer.
+  return Builder.CreateBitCast(Addr, PType);
+}
+
+llvm::Value *
+MicrosoftCXXABI::EmitMemberPointerConversion(CodeGenFunction &CGF,
+                                             const CastExpr *E,
+                                             llvm::Value *Src) {
+  assert(E->getCastKind() == CK_DerivedToBaseMemberPointer ||
+         E->getCastKind() == CK_BaseToDerivedMemberPointer ||
+         E->getCastKind() == CK_ReinterpretMemberPointer);
+
+  // Use constant emission if we can.
+  if (isa<llvm::Constant>(Src))
+    return EmitMemberPointerConversion(E, cast<llvm::Constant>(Src));
+
+  // We may be adding or dropping fields from the member pointer, so we need
+  // both types and the inheritance models of both records.
+  const MemberPointerType *SrcTy =
+    E->getSubExpr()->getType()->castAs<MemberPointerType>();
+  const MemberPointerType *DstTy = E->getType()->castAs<MemberPointerType>();
+  bool IsFunc = SrcTy->isMemberFunctionPointer();
+
+  // If the classes use the same null representation, reinterpret_cast is a nop.
+  bool IsReinterpret = E->getCastKind() == CK_ReinterpretMemberPointer;
+  if (IsReinterpret && IsFunc)
+    return Src;
+
+  CXXRecordDecl *SrcRD = SrcTy->getMostRecentCXXRecordDecl();
+  CXXRecordDecl *DstRD = DstTy->getMostRecentCXXRecordDecl();
+  if (IsReinterpret &&
+      SrcRD->nullFieldOffsetIsZero() == DstRD->nullFieldOffsetIsZero())
+    return Src;
+
+  CGBuilderTy &Builder = CGF.Builder;
+
+  // Branch past the conversion if Src is null.
+  llvm::Value *IsNotNull = EmitMemberPointerIsNotNull(CGF, Src, SrcTy);
+  llvm::Constant *DstNull = EmitNullMemberPointer(DstTy);
+
+  // C++ 5.2.10p9: The null member pointer value is converted to the null member
+  //   pointer value of the destination type.
+  if (IsReinterpret) {
+    // For reinterpret casts, sema ensures that src and dst are both functions
+    // or data and have the same size, which means the LLVM types should match.
+    assert(Src->getType() == DstNull->getType());
+    return Builder.CreateSelect(IsNotNull, Src, DstNull);
+  }
+
+  llvm::BasicBlock *OriginalBB = Builder.GetInsertBlock();
+  llvm::BasicBlock *ConvertBB = CGF.createBasicBlock("memptr.convert");
+  llvm::BasicBlock *ContinueBB = CGF.createBasicBlock("memptr.converted");
+  Builder.CreateCondBr(IsNotNull, ConvertBB, ContinueBB);
+  CGF.EmitBlock(ConvertBB);
+
+  llvm::Value *Dst = EmitNonNullMemberPointerConversion(
+      SrcTy, DstTy, E->getCastKind(), E->path_begin(), E->path_end(), Src,
+      Builder);
+
+  Builder.CreateBr(ContinueBB);
+
+  // In the continuation, choose between DstNull and Dst.
+  CGF.EmitBlock(ContinueBB);
+  llvm::PHINode *Phi = Builder.CreatePHI(DstNull->getType(), 2, "memptr.converted");
+  Phi->addIncoming(DstNull, OriginalBB);
+  Phi->addIncoming(Dst, ConvertBB);
+  return Phi;
+}
+
+llvm::Value *MicrosoftCXXABI::EmitNonNullMemberPointerConversion(
+    const MemberPointerType *SrcTy, const MemberPointerType *DstTy, CastKind CK,
+    CastExpr::path_const_iterator PathBegin,
+    CastExpr::path_const_iterator PathEnd, llvm::Value *Src,
+    CGBuilderTy &Builder) {
+  const CXXRecordDecl *SrcRD = SrcTy->getMostRecentCXXRecordDecl();
+  const CXXRecordDecl *DstRD = DstTy->getMostRecentCXXRecordDecl();
+  MSInheritanceModel SrcInheritance = SrcRD->getMSInheritanceModel();
+  MSInheritanceModel DstInheritance = DstRD->getMSInheritanceModel();
+  bool IsFunc = SrcTy->isMemberFunctionPointer();
+  bool IsConstant = isa<llvm::Constant>(Src);
+
+  // Decompose src.
+  llvm::Value *FirstField = Src;
+  llvm::Value *NonVirtualBaseAdjustment = getZeroInt();
+  llvm::Value *VirtualBaseAdjustmentOffset = getZeroInt();
+  llvm::Value *VBPtrOffset = getZeroInt();
+  if (!inheritanceModelHasOnlyOneField(IsFunc, SrcInheritance)) {
+    // We need to extract values.
+    unsigned I = 0;
+    FirstField = Builder.CreateExtractValue(Src, I++);
+    if (inheritanceModelHasNVOffsetField(IsFunc, SrcInheritance))
+      NonVirtualBaseAdjustment = Builder.CreateExtractValue(Src, I++);
+    if (inheritanceModelHasVBPtrOffsetField(SrcInheritance))
+      VBPtrOffset = Builder.CreateExtractValue(Src, I++);
+    if (inheritanceModelHasVBTableOffsetField(SrcInheritance))
+      VirtualBaseAdjustmentOffset = Builder.CreateExtractValue(Src, I++);
+  }
+
+  bool IsDerivedToBase = (CK == CK_DerivedToBaseMemberPointer);
+  const MemberPointerType *DerivedTy = IsDerivedToBase ? SrcTy : DstTy;
+  const CXXRecordDecl *DerivedClass = DerivedTy->getMostRecentCXXRecordDecl();
+
+  // For data pointers, we adjust the field offset directly.  For functions, we
+  // have a separate field.
+  llvm::Value *&NVAdjustField = IsFunc ? NonVirtualBaseAdjustment : FirstField;
+
+  // The virtual inheritance model has a quirk: the virtual base table is always
+  // referenced when dereferencing a member pointer even if the member pointer
+  // is non-virtual.  This is accounted for by adjusting the non-virtual offset
+  // to point backwards to the top of the MDC from the first VBase.  Undo this
+  // adjustment to normalize the member pointer.
+  llvm::Value *SrcVBIndexEqZero =
+      Builder.CreateICmpEQ(VirtualBaseAdjustmentOffset, getZeroInt());
+  if (SrcInheritance == MSInheritanceModel::Virtual) {
+    if (int64_t SrcOffsetToFirstVBase =
+            getContext().getOffsetOfBaseWithVBPtr(SrcRD).getQuantity()) {
+      llvm::Value *UndoSrcAdjustment = Builder.CreateSelect(
+          SrcVBIndexEqZero,
+          llvm::ConstantInt::get(CGM.IntTy, SrcOffsetToFirstVBase),
+          getZeroInt());
+      NVAdjustField = Builder.CreateNSWAdd(NVAdjustField, UndoSrcAdjustment);
+    }
+  }
+
+  // A non-zero vbindex implies that we are dealing with a source member in a
+  // floating virtual base in addition to some non-virtual offset.  If the
+  // vbindex is zero, we are dealing with a source that exists in a non-virtual,
+  // fixed, base.  The difference between these two cases is that the vbindex +
+  // nvoffset *always* point to the member regardless of what context they are
+  // evaluated in so long as the vbindex is adjusted.  A member inside a fixed
+  // base requires explicit nv adjustment.
+  llvm::Constant *BaseClassOffset = llvm::ConstantInt::get(
+      CGM.IntTy,
+      CGM.computeNonVirtualBaseClassOffset(DerivedClass, PathBegin, PathEnd)
+          .getQuantity());
+
+  llvm::Value *NVDisp;
+  if (IsDerivedToBase)
+    NVDisp = Builder.CreateNSWSub(NVAdjustField, BaseClassOffset, "adj");
+  else
+    NVDisp = Builder.CreateNSWAdd(NVAdjustField, BaseClassOffset, "adj");
+
+  NVAdjustField = Builder.CreateSelect(SrcVBIndexEqZero, NVDisp, getZeroInt());
+
+  // Update the vbindex to an appropriate value in the destination because
+  // SrcRD's vbtable might not be a strict prefix of the one in DstRD.
+  llvm::Value *DstVBIndexEqZero = SrcVBIndexEqZero;
+  if (inheritanceModelHasVBTableOffsetField(DstInheritance) &&
+      inheritanceModelHasVBTableOffsetField(SrcInheritance)) {
+    if (llvm::GlobalVariable *VDispMap =
+            getAddrOfVirtualDisplacementMap(SrcRD, DstRD)) {
+      llvm::Value *VBIndex = Builder.CreateExactUDiv(
+          VirtualBaseAdjustmentOffset, llvm::ConstantInt::get(CGM.IntTy, 4));
+      if (IsConstant) {
+        llvm::Constant *Mapping = VDispMap->getInitializer();
+        VirtualBaseAdjustmentOffset =
+            Mapping->getAggregateElement(cast<llvm::Constant>(VBIndex));
+      } else {
+        llvm::Value *Idxs[] = {getZeroInt(), VBIndex};
+        VirtualBaseAdjustmentOffset =
+            Builder.CreateAlignedLoad(Builder.CreateInBoundsGEP(VDispMap, Idxs),
+                                      CharUnits::fromQuantity(4));
+      }
+
+      DstVBIndexEqZero =
+          Builder.CreateICmpEQ(VirtualBaseAdjustmentOffset, getZeroInt());
+    }
+  }
+
+  // Set the VBPtrOffset to zero if the vbindex is zero.  Otherwise, initialize
+  // it to the offset of the vbptr.
+  if (inheritanceModelHasVBPtrOffsetField(DstInheritance)) {
+    llvm::Value *DstVBPtrOffset = llvm::ConstantInt::get(
+        CGM.IntTy,
+        getContext().getASTRecordLayout(DstRD).getVBPtrOffset().getQuantity());
+    VBPtrOffset =
+        Builder.CreateSelect(DstVBIndexEqZero, getZeroInt(), DstVBPtrOffset);
+  }
+
+  // Likewise, apply a similar adjustment so that dereferencing the member
+  // pointer correctly accounts for the distance between the start of the first
+  // virtual base and the top of the MDC.
+  if (DstInheritance == MSInheritanceModel::Virtual) {
+    if (int64_t DstOffsetToFirstVBase =
+            getContext().getOffsetOfBaseWithVBPtr(DstRD).getQuantity()) {
+      llvm::Value *DoDstAdjustment = Builder.CreateSelect(
+          DstVBIndexEqZero,
+          llvm::ConstantInt::get(CGM.IntTy, DstOffsetToFirstVBase),
+          getZeroInt());
+      NVAdjustField = Builder.CreateNSWSub(NVAdjustField, DoDstAdjustment);
+    }
+  }
+
+  // Recompose dst from the null struct and the adjusted fields from src.
+  llvm::Value *Dst;
+  if (inheritanceModelHasOnlyOneField(IsFunc, DstInheritance)) {
+    Dst = FirstField;
+  } else {
+    Dst = llvm::UndefValue::get(ConvertMemberPointerType(DstTy));
+    unsigned Idx = 0;
+    Dst = Builder.CreateInsertValue(Dst, FirstField, Idx++);
+    if (inheritanceModelHasNVOffsetField(IsFunc, DstInheritance))
+      Dst = Builder.CreateInsertValue(Dst, NonVirtualBaseAdjustment, Idx++);
+    if (inheritanceModelHasVBPtrOffsetField(DstInheritance))
+      Dst = Builder.CreateInsertValue(Dst, VBPtrOffset, Idx++);
+    if (inheritanceModelHasVBTableOffsetField(DstInheritance))
+      Dst = Builder.CreateInsertValue(Dst, VirtualBaseAdjustmentOffset, Idx++);
+  }
+  return Dst;
+}
+
+llvm::Constant *
+MicrosoftCXXABI::EmitMemberPointerConversion(const CastExpr *E,
+                                             llvm::Constant *Src) {
+  const MemberPointerType *SrcTy =
+      E->getSubExpr()->getType()->castAs<MemberPointerType>();
+  const MemberPointerType *DstTy = E->getType()->castAs<MemberPointerType>();
+
+  CastKind CK = E->getCastKind();
+
+  return EmitMemberPointerConversion(SrcTy, DstTy, CK, E->path_begin(),
+                                     E->path_end(), Src);
+}
+
+llvm::Constant *MicrosoftCXXABI::EmitMemberPointerConversion(
+    const MemberPointerType *SrcTy, const MemberPointerType *DstTy, CastKind CK,
+    CastExpr::path_const_iterator PathBegin,
+    CastExpr::path_const_iterator PathEnd, llvm::Constant *Src) {
+  assert(CK == CK_DerivedToBaseMemberPointer ||
+         CK == CK_BaseToDerivedMemberPointer ||
+         CK == CK_ReinterpretMemberPointer);
+  // If src is null, emit a new null for dst.  We can't return src because dst
+  // might have a new representation.
+  if (MemberPointerConstantIsNull(SrcTy, Src))
+    return EmitNullMemberPointer(DstTy);
+
+  // We don't need to do anything for reinterpret_casts of non-null member
+  // pointers.  We should only get here when the two type representations have
+  // the same size.
+  if (CK == CK_ReinterpretMemberPointer)
+    return Src;
+
+  CGBuilderTy Builder(CGM, CGM.getLLVMContext());
+  auto *Dst = cast<llvm::Constant>(EmitNonNullMemberPointerConversion(
+      SrcTy, DstTy, CK, PathBegin, PathEnd, Src, Builder));
+
+  return Dst;
+}
+
+CGCallee MicrosoftCXXABI::EmitLoadOfMemberFunctionPointer(
+    CodeGenFunction &CGF, const Expr *E, Address This,
+    llvm::Value *&ThisPtrForCall, llvm::Value *MemPtr,
+    const MemberPointerType *MPT) {
+  assert(MPT->isMemberFunctionPointer());
+  const FunctionProtoType *FPT =
+    MPT->getPointeeType()->castAs<FunctionProtoType>();
+  const CXXRecordDecl *RD = MPT->getMostRecentCXXRecordDecl();
+  llvm::FunctionType *FTy = CGM.getTypes().GetFunctionType(
+      CGM.getTypes().arrangeCXXMethodType(RD, FPT, /*FD=*/nullptr));
+  CGBuilderTy &Builder = CGF.Builder;
+
+  MSInheritanceModel Inheritance = RD->getMSInheritanceModel();
+
+  // Extract the fields we need, regardless of model.  We'll apply them if we
+  // have them.
+  llvm::Value *FunctionPointer = MemPtr;
+  llvm::Value *NonVirtualBaseAdjustment = nullptr;
+  llvm::Value *VirtualBaseAdjustmentOffset = nullptr;
+  llvm::Value *VBPtrOffset = nullptr;
+  if (MemPtr->getType()->isStructTy()) {
+    // We need to extract values.
+    unsigned I = 0;
+    FunctionPointer = Builder.CreateExtractValue(MemPtr, I++);
+    if (inheritanceModelHasNVOffsetField(MPT, Inheritance))
+      NonVirtualBaseAdjustment = Builder.CreateExtractValue(MemPtr, I++);
+    if (inheritanceModelHasVBPtrOffsetField(Inheritance))
+      VBPtrOffset = Builder.CreateExtractValue(MemPtr, I++);
+    if (inheritanceModelHasVBTableOffsetField(Inheritance))
+      VirtualBaseAdjustmentOffset = Builder.CreateExtractValue(MemPtr, I++);
+  }
+
+  if (VirtualBaseAdjustmentOffset) {
+    ThisPtrForCall = AdjustVirtualBase(CGF, E, RD, This,
+                                   VirtualBaseAdjustmentOffset, VBPtrOffset);
+  } else {
+    ThisPtrForCall = This.getPointer();
+  }
+
+  if (NonVirtualBaseAdjustment) {
+    // Apply the adjustment and cast back to the original struct type.
+    llvm::Value *Ptr = Builder.CreateBitCast(ThisPtrForCall, CGF.Int8PtrTy);
+    Ptr = Builder.CreateInBoundsGEP(Ptr, NonVirtualBaseAdjustment);
+    ThisPtrForCall = Builder.CreateBitCast(Ptr, ThisPtrForCall->getType(),
+                                           "this.adjusted");
+  }
+
+  FunctionPointer =
+    Builder.CreateBitCast(FunctionPointer, FTy->getPointerTo());
+  CGCallee Callee(FPT, FunctionPointer);
+  return Callee;
+}
+
+CGCXXABI *clang::CodeGen::CreateMicrosoftCXXABI(CodeGenModule &CGM) {
+  return new MicrosoftCXXABI(CGM);
+}
+
+// MS RTTI Overview:
+// The run time type information emitted by cl.exe contains 5 distinct types of
+// structures.  Many of them reference each other.
+//
+// TypeInfo:  Static classes that are returned by typeid.
+//
+// CompleteObjectLocator:  Referenced by vftables.  They contain information
+//   required for dynamic casting, including OffsetFromTop.  They also contain
+//   a reference to the TypeInfo for the type and a reference to the
+//   CompleteHierarchyDescriptor for the type.
+//
+// ClassHierarchyDescriptor: Contains information about a class hierarchy.
+//   Used during dynamic_cast to walk a class hierarchy.  References a base
+//   class array and the size of said array.
+//
+// BaseClassArray: Contains a list of classes in a hierarchy.  BaseClassArray is
+//   somewhat of a misnomer because the most derived class is also in the list
+//   as well as multiple copies of virtual bases (if they occur multiple times
+//   in the hierarchy.)  The BaseClassArray contains one BaseClassDescriptor for
+//   every path in the hierarchy, in pre-order depth first order.  Note, we do
+//   not declare a specific llvm type for BaseClassArray, it's merely an array
+//   of BaseClassDescriptor pointers.
+//
+// BaseClassDescriptor: Contains information about a class in a class hierarchy.
+//   BaseClassDescriptor is also somewhat of a misnomer for the same reason that
+//   BaseClassArray is.  It contains information about a class within a
+//   hierarchy such as: is this base is ambiguous and what is its offset in the
+//   vbtable.  The names of the BaseClassDescriptors have all of their fields
+//   mangled into them so they can be aggressively deduplicated by the linker.
+
+static llvm::GlobalVariable *getTypeInfoVTable(CodeGenModule &CGM) {
+  StringRef MangledName("??_7type_info@@6B@");
+  if (auto VTable = CGM.getModule().getNamedGlobal(MangledName))
+    return VTable;
+  return new llvm::GlobalVariable(CGM.getModule(), CGM.Int8PtrTy,
+                                  /*isConstant=*/true,
+                                  llvm::GlobalVariable::ExternalLinkage,
+                                  /*Initializer=*/nullptr, MangledName);
+}
+
+namespace {
+
+/// A Helper struct that stores information about a class in a class
+/// hierarchy.  The information stored in these structs struct is used during
+/// the generation of ClassHierarchyDescriptors and BaseClassDescriptors.
+// During RTTI creation, MSRTTIClasses are stored in a contiguous array with
+// implicit depth first pre-order tree connectivity.  getFirstChild and
+// getNextSibling allow us to walk the tree efficiently.
+struct MSRTTIClass {
+  enum {
+    IsPrivateOnPath = 1 | 8,
+    IsAmbiguous = 2,
+    IsPrivate = 4,
+    IsVirtual = 16,
+    HasHierarchyDescriptor = 64
+  };
+  MSRTTIClass(const CXXRecordDecl *RD) : RD(RD) {}
+  uint32_t initialize(const MSRTTIClass *Parent,
+                      const CXXBaseSpecifier *Specifier);
+
+  MSRTTIClass *getFirstChild() { return this + 1; }
+  static MSRTTIClass *getNextChild(MSRTTIClass *Child) {
+    return Child + 1 + Child->NumBases;
+  }
+
+  const CXXRecordDecl *RD, *VirtualRoot;
+  uint32_t Flags, NumBases, OffsetInVBase;
+};
+
+/// Recursively initialize the base class array.
+uint32_t MSRTTIClass::initialize(const MSRTTIClass *Parent,
+                                 const CXXBaseSpecifier *Specifier) {
+  Flags = HasHierarchyDescriptor;
+  if (!Parent) {
+    VirtualRoot = nullptr;
+    OffsetInVBase = 0;
+  } else {
+    if (Specifier->getAccessSpecifier() != AS_public)
+      Flags |= IsPrivate | IsPrivateOnPath;
+    if (Specifier->isVirtual()) {
+      Flags |= IsVirtual;
+      VirtualRoot = RD;
+      OffsetInVBase = 0;
+    } else {
+      if (Parent->Flags & IsPrivateOnPath)
+        Flags |= IsPrivateOnPath;
+      VirtualRoot = Parent->VirtualRoot;
+      OffsetInVBase = Parent->OffsetInVBase + RD->getASTContext()
+          .getASTRecordLayout(Parent->RD).getBaseClassOffset(RD).getQuantity();
+    }
+  }
+  NumBases = 0;
+  MSRTTIClass *Child = getFirstChild();
+  for (const CXXBaseSpecifier &Base : RD->bases()) {
+    NumBases += Child->initialize(this, &Base) + 1;
+    Child = getNextChild(Child);
+  }
+  return NumBases;
+}
+
+static llvm::GlobalValue::LinkageTypes getLinkageForRTTI(QualType Ty) {
+  switch (Ty->getLinkage()) {
+  case NoLinkage:
+  case InternalLinkage:
+  case UniqueExternalLinkage:
+    return llvm::GlobalValue::InternalLinkage;
+
+  case VisibleNoLinkage:
+  case ModuleInternalLinkage:
+  case ModuleLinkage:
+  case ExternalLinkage:
+    return llvm::GlobalValue::LinkOnceODRLinkage;
+  }
+  llvm_unreachable("Invalid linkage!");
+}
+
+/// An ephemeral helper class for building MS RTTI types.  It caches some
+/// calls to the module and information about the most derived class in a
+/// hierarchy.
+struct MSRTTIBuilder {
+  enum {
+    HasBranchingHierarchy = 1,
+    HasVirtualBranchingHierarchy = 2,
+    HasAmbiguousBases = 4
+  };
+
+  MSRTTIBuilder(MicrosoftCXXABI &ABI, const CXXRecordDecl *RD)
+      : CGM(ABI.CGM), Context(CGM.getContext()),
+        VMContext(CGM.getLLVMContext()), Module(CGM.getModule()), RD(RD),
+        Linkage(getLinkageForRTTI(CGM.getContext().getTagDeclType(RD))),
+        ABI(ABI) {}
+
+  llvm::GlobalVariable *getBaseClassDescriptor(const MSRTTIClass &Classes);
+  llvm::GlobalVariable *
+  getBaseClassArray(SmallVectorImpl<MSRTTIClass> &Classes);
+  llvm::GlobalVariable *getClassHierarchyDescriptor();
+  llvm::GlobalVariable *getCompleteObjectLocator(const VPtrInfo &Info);
+
+  CodeGenModule &CGM;
+  ASTContext &Context;
+  llvm::LLVMContext &VMContext;
+  llvm::Module &Module;
+  const CXXRecordDecl *RD;
+  llvm::GlobalVariable::LinkageTypes Linkage;
+  MicrosoftCXXABI &ABI;
+};
+
+} // namespace
+
+/// Recursively serializes a class hierarchy in pre-order depth first
+/// order.
+static void serializeClassHierarchy(SmallVectorImpl<MSRTTIClass> &Classes,
+                                    const CXXRecordDecl *RD) {
+  Classes.push_back(MSRTTIClass(RD));
+  for (const CXXBaseSpecifier &Base : RD->bases())
+    serializeClassHierarchy(Classes, Base.getType()->getAsCXXRecordDecl());
+}
+
+/// Find ambiguity among base classes.
+static void
+detectAmbiguousBases(SmallVectorImpl<MSRTTIClass> &Classes) {
+  llvm::SmallPtrSet<const CXXRecordDecl *, 8> VirtualBases;
+  llvm::SmallPtrSet<const CXXRecordDecl *, 8> UniqueBases;
+  llvm::SmallPtrSet<const CXXRecordDecl *, 8> AmbiguousBases;
+  for (MSRTTIClass *Class = &Classes.front(); Class <= &Classes.back();) {
+    if ((Class->Flags & MSRTTIClass::IsVirtual) &&
+        !VirtualBases.insert(Class->RD).second) {
+      Class = MSRTTIClass::getNextChild(Class);
+      continue;
+    }
+    if (!UniqueBases.insert(Class->RD).second)
+      AmbiguousBases.insert(Class->RD);
+    Class++;
+  }
+  if (AmbiguousBases.empty())
+    return;
+  for (MSRTTIClass &Class : Classes)
+    if (AmbiguousBases.count(Class.RD))
+      Class.Flags |= MSRTTIClass::IsAmbiguous;
+}
+
+llvm::GlobalVariable *MSRTTIBuilder::getClassHierarchyDescriptor() {
+  SmallString<256> MangledName;
+  {
+    llvm::raw_svector_ostream Out(MangledName);
+    ABI.getMangleContext().mangleCXXRTTIClassHierarchyDescriptor(RD, Out);
+  }
+
+  // Check to see if we've already declared this ClassHierarchyDescriptor.
+  if (auto CHD = Module.getNamedGlobal(MangledName))
+    return CHD;
+
+  // Serialize the class hierarchy and initialize the CHD Fields.
+  SmallVector<MSRTTIClass, 8> Classes;
+  serializeClassHierarchy(Classes, RD);
+  Classes.front().initialize(/*Parent=*/nullptr, /*Specifier=*/nullptr);
+  detectAmbiguousBases(Classes);
+  int Flags = 0;
+  for (auto Class : Classes) {
+    if (Class.RD->getNumBases() > 1)
+      Flags |= HasBranchingHierarchy;
+    // Note: cl.exe does not calculate "HasAmbiguousBases" correctly.  We
+    // believe the field isn't actually used.
+    if (Class.Flags & MSRTTIClass::IsAmbiguous)
+      Flags |= HasAmbiguousBases;
+  }
+  if ((Flags & HasBranchingHierarchy) && RD->getNumVBases() != 0)
+    Flags |= HasVirtualBranchingHierarchy;
+  // These gep indices are used to get the address of the first element of the
+  // base class array.
+  llvm::Value *GEPIndices[] = {llvm::ConstantInt::get(CGM.IntTy, 0),
+                               llvm::ConstantInt::get(CGM.IntTy, 0)};
+
+  // Forward-declare the class hierarchy descriptor
+  auto Type = ABI.getClassHierarchyDescriptorType();
+  auto CHD = new llvm::GlobalVariable(Module, Type, /*isConstant=*/true, Linkage,
+                                      /*Initializer=*/nullptr,
+                                      MangledName);
+  if (CHD->isWeakForLinker())
+    CHD->setComdat(CGM.getModule().getOrInsertComdat(CHD->getName()));
+
+  auto *Bases = getBaseClassArray(Classes);
+
+  // Initialize the base class ClassHierarchyDescriptor.
+  llvm::Constant *Fields[] = {
+      llvm::ConstantInt::get(CGM.IntTy, 0), // reserved by the runtime
+      llvm::ConstantInt::get(CGM.IntTy, Flags),
+      llvm::ConstantInt::get(CGM.IntTy, Classes.size()),
+      ABI.getImageRelativeConstant(llvm::ConstantExpr::getInBoundsGetElementPtr(
+          Bases->getValueType(), Bases,
+          llvm::ArrayRef<llvm::Value *>(GEPIndices))),
+  };
+  CHD->setInitializer(llvm::ConstantStruct::get(Type, Fields));
+  return CHD;
+}
+
+llvm::GlobalVariable *
+MSRTTIBuilder::getBaseClassArray(SmallVectorImpl<MSRTTIClass> &Classes) {
+  SmallString<256> MangledName;
+  {
+    llvm::raw_svector_ostream Out(MangledName);
+    ABI.getMangleContext().mangleCXXRTTIBaseClassArray(RD, Out);
+  }
+
+  // Forward-declare the base class array.
+  // cl.exe pads the base class array with 1 (in 32 bit mode) or 4 (in 64 bit
+  // mode) bytes of padding.  We provide a pointer sized amount of padding by
+  // adding +1 to Classes.size().  The sections have pointer alignment and are
+  // marked pick-any so it shouldn't matter.
+  llvm::Type *PtrType = ABI.getImageRelativeType(
+      ABI.getBaseClassDescriptorType()->getPointerTo());
+  auto *ArrType = llvm::ArrayType::get(PtrType, Classes.size() + 1);
+  auto *BCA =
+      new llvm::GlobalVariable(Module, ArrType,
+                               /*isConstant=*/true, Linkage,
+                               /*Initializer=*/nullptr, MangledName);
+  if (BCA->isWeakForLinker())
+    BCA->setComdat(CGM.getModule().getOrInsertComdat(BCA->getName()));
+
+  // Initialize the BaseClassArray.
+  SmallVector<llvm::Constant *, 8> BaseClassArrayData;
+  for (MSRTTIClass &Class : Classes)
+    BaseClassArrayData.push_back(
+        ABI.getImageRelativeConstant(getBaseClassDescriptor(Class)));
+  BaseClassArrayData.push_back(llvm::Constant::getNullValue(PtrType));
+  BCA->setInitializer(llvm::ConstantArray::get(ArrType, BaseClassArrayData));
+  return BCA;
+}
+
+llvm::GlobalVariable *
+MSRTTIBuilder::getBaseClassDescriptor(const MSRTTIClass &Class) {
+  // Compute the fields for the BaseClassDescriptor.  They are computed up front
+  // because they are mangled into the name of the object.
+  uint32_t OffsetInVBTable = 0;
+  int32_t VBPtrOffset = -1;
+  if (Class.VirtualRoot) {
+    auto &VTableContext = CGM.getMicrosoftVTableContext();
+    OffsetInVBTable = VTableContext.getVBTableIndex(RD, Class.VirtualRoot) * 4;
+    VBPtrOffset = Context.getASTRecordLayout(RD).getVBPtrOffset().getQuantity();
+  }
+
+  SmallString<256> MangledName;
+  {
+    llvm::raw_svector_ostream Out(MangledName);
+    ABI.getMangleContext().mangleCXXRTTIBaseClassDescriptor(
+        Class.RD, Class.OffsetInVBase, VBPtrOffset, OffsetInVBTable,
+        Class.Flags, Out);
+  }
+
+  // Check to see if we've already declared this object.
+  if (auto BCD = Module.getNamedGlobal(MangledName))
+    return BCD;
+
+  // Forward-declare the base class descriptor.
+  auto Type = ABI.getBaseClassDescriptorType();
+  auto BCD =
+      new llvm::GlobalVariable(Module, Type, /*isConstant=*/true, Linkage,
+                               /*Initializer=*/nullptr, MangledName);
+  if (BCD->isWeakForLinker())
+    BCD->setComdat(CGM.getModule().getOrInsertComdat(BCD->getName()));
+
+  // Initialize the BaseClassDescriptor.
+  llvm::Constant *Fields[] = {
+      ABI.getImageRelativeConstant(
+          ABI.getAddrOfRTTIDescriptor(Context.getTypeDeclType(Class.RD))),
+      llvm::ConstantInt::get(CGM.IntTy, Class.NumBases),
+      llvm::ConstantInt::get(CGM.IntTy, Class.OffsetInVBase),
+      llvm::ConstantInt::get(CGM.IntTy, VBPtrOffset),
+      llvm::ConstantInt::get(CGM.IntTy, OffsetInVBTable),
+      llvm::ConstantInt::get(CGM.IntTy, Class.Flags),
+      ABI.getImageRelativeConstant(
+          MSRTTIBuilder(ABI, Class.RD).getClassHierarchyDescriptor()),
+  };
+  BCD->setInitializer(llvm::ConstantStruct::get(Type, Fields));
+  return BCD;
+}
+
+llvm::GlobalVariable *
+MSRTTIBuilder::getCompleteObjectLocator(const VPtrInfo &Info) {
+  SmallString<256> MangledName;
+  {
+    llvm::raw_svector_ostream Out(MangledName);
+    ABI.getMangleContext().mangleCXXRTTICompleteObjectLocator(RD, Info.MangledPath, Out);
+  }
+
+  // Check to see if we've already computed this complete object locator.
+  if (auto COL = Module.getNamedGlobal(MangledName))
+    return COL;
+
+  // Compute the fields of the complete object locator.
+  int OffsetToTop = Info.FullOffsetInMDC.getQuantity();
+  int VFPtrOffset = 0;
+  // The offset includes the vtordisp if one exists.
+  if (const CXXRecordDecl *VBase = Info.getVBaseWithVPtr())
+    if (Context.getASTRecordLayout(RD)
+      .getVBaseOffsetsMap()
+      .find(VBase)
+      ->second.hasVtorDisp())
+      VFPtrOffset = Info.NonVirtualOffset.getQuantity() + 4;
+
+  // Forward-declare the complete object locator.
+  llvm::StructType *Type = ABI.getCompleteObjectLocatorType();
+  auto COL = new llvm::GlobalVariable(Module, Type, /*isConstant=*/true, Linkage,
+    /*Initializer=*/nullptr, MangledName);
+
+  // Initialize the CompleteObjectLocator.
+  llvm::Constant *Fields[] = {
+      llvm::ConstantInt::get(CGM.IntTy, ABI.isImageRelative()),
+      llvm::ConstantInt::get(CGM.IntTy, OffsetToTop),
+      llvm::ConstantInt::get(CGM.IntTy, VFPtrOffset),
+      ABI.getImageRelativeConstant(
+          CGM.GetAddrOfRTTIDescriptor(Context.getTypeDeclType(RD))),
+      ABI.getImageRelativeConstant(getClassHierarchyDescriptor()),
+      ABI.getImageRelativeConstant(COL),
+  };
+  llvm::ArrayRef<llvm::Constant *> FieldsRef(Fields);
+  if (!ABI.isImageRelative())
+    FieldsRef = FieldsRef.drop_back();
+  COL->setInitializer(llvm::ConstantStruct::get(Type, FieldsRef));
+  if (COL->isWeakForLinker())
+    COL->setComdat(CGM.getModule().getOrInsertComdat(COL->getName()));
+  return COL;
+}
+
+static QualType decomposeTypeForEH(ASTContext &Context, QualType T,
+                                   bool &IsConst, bool &IsVolatile,
+                                   bool &IsUnaligned) {
+  T = Context.getExceptionObjectType(T);
+
+  // C++14 [except.handle]p3:
+  //   A handler is a match for an exception object of type E if [...]
+  //     - the handler is of type cv T or const T& where T is a pointer type and
+  //       E is a pointer type that can be converted to T by [...]
+  //         - a qualification conversion
+  IsConst = false;
+  IsVolatile = false;
+  IsUnaligned = false;
+  QualType PointeeType = T->getPointeeType();
+  if (!PointeeType.isNull()) {
+    IsConst = PointeeType.isConstQualified();
+    IsVolatile = PointeeType.isVolatileQualified();
+    IsUnaligned = PointeeType.getQualifiers().hasUnaligned();
+  }
+
+  // Member pointer types like "const int A::*" are represented by having RTTI
+  // for "int A::*" and separately storing the const qualifier.
+  if (const auto *MPTy = T->getAs<MemberPointerType>())
+    T = Context.getMemberPointerType(PointeeType.getUnqualifiedType(),
+                                     MPTy->getClass());
+
+  // Pointer types like "const int * const *" are represented by having RTTI
+  // for "const int **" and separately storing the const qualifier.
+  if (T->isPointerType())
+    T = Context.getPointerType(PointeeType.getUnqualifiedType());
+
+  return T;
+}
+
+CatchTypeInfo
+MicrosoftCXXABI::getAddrOfCXXCatchHandlerType(QualType Type,
+                                              QualType CatchHandlerType) {
+  // TypeDescriptors for exceptions never have qualified pointer types,
+  // qualifiers are stored separately in order to support qualification
+  // conversions.
+  bool IsConst, IsVolatile, IsUnaligned;
+  Type =
+      decomposeTypeForEH(getContext(), Type, IsConst, IsVolatile, IsUnaligned);
+
+  bool IsReference = CatchHandlerType->isReferenceType();
+
+  uint32_t Flags = 0;
+  if (IsConst)
+    Flags |= 1;
+  if (IsVolatile)
+    Flags |= 2;
+  if (IsUnaligned)
+    Flags |= 4;
+  if (IsReference)
+    Flags |= 8;
+
+  return CatchTypeInfo{getAddrOfRTTIDescriptor(Type)->stripPointerCasts(),
+                       Flags};
+}
+
+/// Gets a TypeDescriptor.  Returns a llvm::Constant * rather than a
+/// llvm::GlobalVariable * because different type descriptors have different
+/// types, and need to be abstracted.  They are abstracting by casting the
+/// address to an Int8PtrTy.
+llvm::Constant *MicrosoftCXXABI::getAddrOfRTTIDescriptor(QualType Type) {
+  SmallString<256> MangledName;
+  {
+    llvm::raw_svector_ostream Out(MangledName);
+    getMangleContext().mangleCXXRTTI(Type, Out);
+  }
+
+  // Check to see if we've already declared this TypeDescriptor.
+  if (llvm::GlobalVariable *GV = CGM.getModule().getNamedGlobal(MangledName))
+    return llvm::ConstantExpr::getBitCast(GV, CGM.Int8PtrTy);
+
+  // Note for the future: If we would ever like to do deferred emission of
+  // RTTI, check if emitting vtables opportunistically need any adjustment.
+
+  // Compute the fields for the TypeDescriptor.
+  SmallString<256> TypeInfoString;
+  {
+    llvm::raw_svector_ostream Out(TypeInfoString);
+    getMangleContext().mangleCXXRTTIName(Type, Out);
+  }
+
+  // Declare and initialize the TypeDescriptor.
+  llvm::Constant *Fields[] = {
+    getTypeInfoVTable(CGM),                        // VFPtr
+    llvm::ConstantPointerNull::get(CGM.Int8PtrTy), // Runtime data
+    llvm::ConstantDataArray::getString(CGM.getLLVMContext(), TypeInfoString)};
+  llvm::StructType *TypeDescriptorType =
+      getTypeDescriptorType(TypeInfoString);
+  auto *Var = new llvm::GlobalVariable(
+      CGM.getModule(), TypeDescriptorType, /*isConstant=*/false,
+      getLinkageForRTTI(Type),
+      llvm::ConstantStruct::get(TypeDescriptorType, Fields),
+      MangledName);
+  if (Var->isWeakForLinker())
+    Var->setComdat(CGM.getModule().getOrInsertComdat(Var->getName()));
+  return llvm::ConstantExpr::getBitCast(Var, CGM.Int8PtrTy);
+}
+
+/// Gets or a creates a Microsoft CompleteObjectLocator.
+llvm::GlobalVariable *
+MicrosoftCXXABI::getMSCompleteObjectLocator(const CXXRecordDecl *RD,
+                                            const VPtrInfo &Info) {
+  return MSRTTIBuilder(*this, RD).getCompleteObjectLocator(Info);
+}
+
+void MicrosoftCXXABI::emitCXXStructor(GlobalDecl GD) {
+  if (auto *ctor = dyn_cast<CXXConstructorDecl>(GD.getDecl())) {
+    // There are no constructor variants, always emit the complete destructor.
+    llvm::Function *Fn =
+        CGM.codegenCXXStructor(GD.getWithCtorType(Ctor_Complete));
+    CGM.maybeSetTrivialComdat(*ctor, *Fn);
+    return;
+  }
+
+  auto *dtor = cast<CXXDestructorDecl>(GD.getDecl());
+
+  // Emit the base destructor if the base and complete (vbase) destructors are
+  // equivalent. This effectively implements -mconstructor-aliases as part of
+  // the ABI.
+  if (GD.getDtorType() == Dtor_Complete &&
+      dtor->getParent()->getNumVBases() == 0)
+    GD = GD.getWithDtorType(Dtor_Base);
+
+  // The base destructor is equivalent to the base destructor of its
+  // base class if there is exactly one non-virtual base class with a
+  // non-trivial destructor, there are no fields with a non-trivial
+  // destructor, and the body of the destructor is trivial.
+  if (GD.getDtorType() == Dtor_Base && !CGM.TryEmitBaseDestructorAsAlias(dtor))
+    return;
+
+  llvm::Function *Fn = CGM.codegenCXXStructor(GD);
+  if (Fn->isWeakForLinker())
+    Fn->setComdat(CGM.getModule().getOrInsertComdat(Fn->getName()));
+}
+
+llvm::Function *
+MicrosoftCXXABI::getAddrOfCXXCtorClosure(const CXXConstructorDecl *CD,
+                                         CXXCtorType CT) {
+  assert(CT == Ctor_CopyingClosure || CT == Ctor_DefaultClosure);
+
+  // Calculate the mangled name.
+  SmallString<256> ThunkName;
+  llvm::raw_svector_ostream Out(ThunkName);
+  getMangleContext().mangleCXXCtor(CD, CT, Out);
+
+  // If the thunk has been generated previously, just return it.
+  if (llvm::GlobalValue *GV = CGM.getModule().getNamedValue(ThunkName))
+    return cast<llvm::Function>(GV);
+
+  // Create the llvm::Function.
+  const CGFunctionInfo &FnInfo = CGM.getTypes().arrangeMSCtorClosure(CD, CT);
+  llvm::FunctionType *ThunkTy = CGM.getTypes().GetFunctionType(FnInfo);
+  const CXXRecordDecl *RD = CD->getParent();
+  QualType RecordTy = getContext().getRecordType(RD);
+  llvm::Function *ThunkFn = llvm::Function::Create(
+      ThunkTy, getLinkageForRTTI(RecordTy), ThunkName.str(), &CGM.getModule());
+  ThunkFn->setCallingConv(static_cast<llvm::CallingConv::ID>(
+      FnInfo.getEffectiveCallingConvention()));
+  if (ThunkFn->isWeakForLinker())
+    ThunkFn->setComdat(CGM.getModule().getOrInsertComdat(ThunkFn->getName()));
+  bool IsCopy = CT == Ctor_CopyingClosure;
+
+  // Start codegen.
+  CodeGenFunction CGF(CGM);
+  CGF.CurGD = GlobalDecl(CD, Ctor_Complete);
+
+  // Build FunctionArgs.
+  FunctionArgList FunctionArgs;
+
+  // A constructor always starts with a 'this' pointer as its first argument.
+  buildThisParam(CGF, FunctionArgs);
+
+  // Following the 'this' pointer is a reference to the source object that we
+  // are copying from.
+  ImplicitParamDecl SrcParam(
+      getContext(), /*DC=*/nullptr, SourceLocation(),
+      &getContext().Idents.get("src"),
+      getContext().getLValueReferenceType(RecordTy,
+                                          /*SpelledAsLValue=*/true),
+      ImplicitParamDecl::Other);
+  if (IsCopy)
+    FunctionArgs.push_back(&SrcParam);
+
+  // Constructors for classes which utilize virtual bases have an additional
+  // parameter which indicates whether or not it is being delegated to by a more
+  // derived constructor.
+  ImplicitParamDecl IsMostDerived(getContext(), /*DC=*/nullptr,
+                                  SourceLocation(),
+                                  &getContext().Idents.get("is_most_derived"),
+                                  getContext().IntTy, ImplicitParamDecl::Other);
+  // Only add the parameter to the list if the class has virtual bases.
+  if (RD->getNumVBases() > 0)
+    FunctionArgs.push_back(&IsMostDerived);
+
+  // Start defining the function.
+  auto NL = ApplyDebugLocation::CreateEmpty(CGF);
+  CGF.StartFunction(GlobalDecl(), FnInfo.getReturnType(), ThunkFn, FnInfo,
+                    FunctionArgs, CD->getLocation(), SourceLocation());
+  // Create a scope with an artificial location for the body of this function.
+  auto AL = ApplyDebugLocation::CreateArtificial(CGF);
+  setCXXABIThisValue(CGF, loadIncomingCXXThis(CGF));
+  llvm::Value *This = getThisValue(CGF);
+
+  llvm::Value *SrcVal =
+      IsCopy ? CGF.Builder.CreateLoad(CGF.GetAddrOfLocalVar(&SrcParam), "src")
+             : nullptr;
+
+  CallArgList Args;
+
+  // Push the this ptr.
+  Args.add(RValue::get(This), CD->getThisType());
+
+  // Push the src ptr.
+  if (SrcVal)
+    Args.add(RValue::get(SrcVal), SrcParam.getType());
+
+  // Add the rest of the default arguments.
+  SmallVector<const Stmt *, 4> ArgVec;
+  ArrayRef<ParmVarDecl *> params = CD->parameters().drop_front(IsCopy ? 1 : 0);
+  for (const ParmVarDecl *PD : params) {
+    assert(PD->hasDefaultArg() && "ctor closure lacks default args");
+    ArgVec.push_back(PD->getDefaultArg());
+  }
+
+  CodeGenFunction::RunCleanupsScope Cleanups(CGF);
+
+  const auto *FPT = CD->getType()->castAs<FunctionProtoType>();
+  CGF.EmitCallArgs(Args, FPT, llvm::makeArrayRef(ArgVec), CD, IsCopy ? 1 : 0);
+
+  // Insert any ABI-specific implicit constructor arguments.
+  AddedStructorArgs ExtraArgs =
+      addImplicitConstructorArgs(CGF, CD, Ctor_Complete,
+                                 /*ForVirtualBase=*/false,
+                                 /*Delegating=*/false, Args);
+  // Call the destructor with our arguments.
+  llvm::Constant *CalleePtr =
+      CGM.getAddrOfCXXStructor(GlobalDecl(CD, Ctor_Complete));
+  CGCallee Callee =
+      CGCallee::forDirect(CalleePtr, GlobalDecl(CD, Ctor_Complete));
+  const CGFunctionInfo &CalleeInfo = CGM.getTypes().arrangeCXXConstructorCall(
+      Args, CD, Ctor_Complete, ExtraArgs.Prefix, ExtraArgs.Suffix);
+  CGF.EmitCall(CalleeInfo, Callee, ReturnValueSlot(), Args);
+
+  Cleanups.ForceCleanup();
+
+  // Emit the ret instruction, remove any temporary instructions created for the
+  // aid of CodeGen.
+  CGF.FinishFunction(SourceLocation());
+
+  return ThunkFn;
+}
+
+llvm::Constant *MicrosoftCXXABI::getCatchableType(QualType T,
+                                                  uint32_t NVOffset,
+                                                  int32_t VBPtrOffset,
+                                                  uint32_t VBIndex) {
+  assert(!T->isReferenceType());
+
+  CXXRecordDecl *RD = T->getAsCXXRecordDecl();
+  const CXXConstructorDecl *CD =
+      RD ? CGM.getContext().getCopyConstructorForExceptionObject(RD) : nullptr;
+  CXXCtorType CT = Ctor_Complete;
+  if (CD)
+    if (!hasDefaultCXXMethodCC(getContext(), CD) || CD->getNumParams() != 1)
+      CT = Ctor_CopyingClosure;
+
+  uint32_t Size = getContext().getTypeSizeInChars(T).getQuantity();
+  SmallString<256> MangledName;
+  {
+    llvm::raw_svector_ostream Out(MangledName);
+    getMangleContext().mangleCXXCatchableType(T, CD, CT, Size, NVOffset,
+                                              VBPtrOffset, VBIndex, Out);
+  }
+  if (llvm::GlobalVariable *GV = CGM.getModule().getNamedGlobal(MangledName))
+    return getImageRelativeConstant(GV);
+
+  // The TypeDescriptor is used by the runtime to determine if a catch handler
+  // is appropriate for the exception object.
+  llvm::Constant *TD = getImageRelativeConstant(getAddrOfRTTIDescriptor(T));
+
+  // The runtime is responsible for calling the copy constructor if the
+  // exception is caught by value.
+  llvm::Constant *CopyCtor;
+  if (CD) {
+    if (CT == Ctor_CopyingClosure)
+      CopyCtor = getAddrOfCXXCtorClosure(CD, Ctor_CopyingClosure);
+    else
+      CopyCtor = CGM.getAddrOfCXXStructor(GlobalDecl(CD, Ctor_Complete));
+
+    CopyCtor = llvm::ConstantExpr::getBitCast(CopyCtor, CGM.Int8PtrTy);
+  } else {
+    CopyCtor = llvm::Constant::getNullValue(CGM.Int8PtrTy);
+  }
+  CopyCtor = getImageRelativeConstant(CopyCtor);
+
+  bool IsScalar = !RD;
+  bool HasVirtualBases = false;
+  bool IsStdBadAlloc = false; // std::bad_alloc is special for some reason.
+  QualType PointeeType = T;
+  if (T->isPointerType())
+    PointeeType = T->getPointeeType();
+  if (const CXXRecordDecl *RD = PointeeType->getAsCXXRecordDecl()) {
+    HasVirtualBases = RD->getNumVBases() > 0;
+    if (IdentifierInfo *II = RD->getIdentifier())
+      IsStdBadAlloc = II->isStr("bad_alloc") && RD->isInStdNamespace();
+  }
+
+  // Encode the relevant CatchableType properties into the Flags bitfield.
+  // FIXME: Figure out how bits 2 or 8 can get set.
+  uint32_t Flags = 0;
+  if (IsScalar)
+    Flags |= 1;
+  if (HasVirtualBases)
+    Flags |= 4;
+  if (IsStdBadAlloc)
+    Flags |= 16;
+
+  llvm::Constant *Fields[] = {
+      llvm::ConstantInt::get(CGM.IntTy, Flags),       // Flags
+      TD,                                             // TypeDescriptor
+      llvm::ConstantInt::get(CGM.IntTy, NVOffset),    // NonVirtualAdjustment
+      llvm::ConstantInt::get(CGM.IntTy, VBPtrOffset), // OffsetToVBPtr
+      llvm::ConstantInt::get(CGM.IntTy, VBIndex),     // VBTableIndex
+      llvm::ConstantInt::get(CGM.IntTy, Size),        // Size
+      CopyCtor                                        // CopyCtor
+  };
+  llvm::StructType *CTType = getCatchableTypeType();
+  auto *GV = new llvm::GlobalVariable(
+      CGM.getModule(), CTType, /*isConstant=*/true, getLinkageForRTTI(T),
+      llvm::ConstantStruct::get(CTType, Fields), MangledName);
+  GV->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
+  GV->setSection(".xdata");
+  if (GV->isWeakForLinker())
+    GV->setComdat(CGM.getModule().getOrInsertComdat(GV->getName()));
+  return getImageRelativeConstant(GV);
+}
+
+llvm::GlobalVariable *MicrosoftCXXABI::getCatchableTypeArray(QualType T) {
+  assert(!T->isReferenceType());
+
+  // See if we've already generated a CatchableTypeArray for this type before.
+  llvm::GlobalVariable *&CTA = CatchableTypeArrays[T];
+  if (CTA)
+    return CTA;
+
+  // Ensure that we don't have duplicate entries in our CatchableTypeArray by
+  // using a SmallSetVector.  Duplicates may arise due to virtual bases
+  // occurring more than once in the hierarchy.
+  llvm::SmallSetVector<llvm::Constant *, 2> CatchableTypes;
+
+  // C++14 [except.handle]p3:
+  //   A handler is a match for an exception object of type E if [...]
+  //     - the handler is of type cv T or cv T& and T is an unambiguous public
+  //       base class of E, or
+  //     - the handler is of type cv T or const T& where T is a pointer type and
+  //       E is a pointer type that can be converted to T by [...]
+  //         - a standard pointer conversion (4.10) not involving conversions to
+  //           pointers to private or protected or ambiguous classes
+  const CXXRecordDecl *MostDerivedClass = nullptr;
+  bool IsPointer = T->isPointerType();
+  if (IsPointer)
+    MostDerivedClass = T->getPointeeType()->getAsCXXRecordDecl();
+  else
+    MostDerivedClass = T->getAsCXXRecordDecl();
+
+  // Collect all the unambiguous public bases of the MostDerivedClass.
+  if (MostDerivedClass) {
+    const ASTContext &Context = getContext();
+    const ASTRecordLayout &MostDerivedLayout =
+        Context.getASTRecordLayout(MostDerivedClass);
+    MicrosoftVTableContext &VTableContext = CGM.getMicrosoftVTableContext();
+    SmallVector<MSRTTIClass, 8> Classes;
+    serializeClassHierarchy(Classes, MostDerivedClass);
+    Classes.front().initialize(/*Parent=*/nullptr, /*Specifier=*/nullptr);
+    detectAmbiguousBases(Classes);
+    for (const MSRTTIClass &Class : Classes) {
+      // Skip any ambiguous or private bases.
+      if (Class.Flags &
+          (MSRTTIClass::IsPrivateOnPath | MSRTTIClass::IsAmbiguous))
+        continue;
+      // Write down how to convert from a derived pointer to a base pointer.
+      uint32_t OffsetInVBTable = 0;
+      int32_t VBPtrOffset = -1;
+      if (Class.VirtualRoot) {
+        OffsetInVBTable =
+          VTableContext.getVBTableIndex(MostDerivedClass, Class.VirtualRoot)*4;
+        VBPtrOffset = MostDerivedLayout.getVBPtrOffset().getQuantity();
+      }
+
+      // Turn our record back into a pointer if the exception object is a
+      // pointer.
+      QualType RTTITy = QualType(Class.RD->getTypeForDecl(), 0);
+      if (IsPointer)
+        RTTITy = Context.getPointerType(RTTITy);
+      CatchableTypes.insert(getCatchableType(RTTITy, Class.OffsetInVBase,
+                                             VBPtrOffset, OffsetInVBTable));
+    }
+  }
+
+  // C++14 [except.handle]p3:
+  //   A handler is a match for an exception object of type E if
+  //     - The handler is of type cv T or cv T& and E and T are the same type
+  //       (ignoring the top-level cv-qualifiers)
+  CatchableTypes.insert(getCatchableType(T));
+
+  // C++14 [except.handle]p3:
+  //   A handler is a match for an exception object of type E if
+  //     - the handler is of type cv T or const T& where T is a pointer type and
+  //       E is a pointer type that can be converted to T by [...]
+  //         - a standard pointer conversion (4.10) not involving conversions to
+  //           pointers to private or protected or ambiguous classes
+  //
+  // C++14 [conv.ptr]p2:
+  //   A prvalue of type "pointer to cv T," where T is an object type, can be
+  //   converted to a prvalue of type "pointer to cv void".
+  if (IsPointer && T->getPointeeType()->isObjectType())
+    CatchableTypes.insert(getCatchableType(getContext().VoidPtrTy));
+
+  // C++14 [except.handle]p3:
+  //   A handler is a match for an exception object of type E if [...]
+  //     - the handler is of type cv T or const T& where T is a pointer or
+  //       pointer to member type and E is std::nullptr_t.
+  //
+  // We cannot possibly list all possible pointer types here, making this
+  // implementation incompatible with the standard.  However, MSVC includes an
+  // entry for pointer-to-void in this case.  Let's do the same.
+  if (T->isNullPtrType())
+    CatchableTypes.insert(getCatchableType(getContext().VoidPtrTy));
+
+  uint32_t NumEntries = CatchableTypes.size();
+  llvm::Type *CTType =
+      getImageRelativeType(getCatchableTypeType()->getPointerTo());
+  llvm::ArrayType *AT = llvm::ArrayType::get(CTType, NumEntries);
+  llvm::StructType *CTAType = getCatchableTypeArrayType(NumEntries);
+  llvm::Constant *Fields[] = {
+      llvm::ConstantInt::get(CGM.IntTy, NumEntries),    // NumEntries
+      llvm::ConstantArray::get(
+          AT, llvm::makeArrayRef(CatchableTypes.begin(),
+                                 CatchableTypes.end())) // CatchableTypes
+  };
+  SmallString<256> MangledName;
+  {
+    llvm::raw_svector_ostream Out(MangledName);
+    getMangleContext().mangleCXXCatchableTypeArray(T, NumEntries, Out);
+  }
+  CTA = new llvm::GlobalVariable(
+      CGM.getModule(), CTAType, /*isConstant=*/true, getLinkageForRTTI(T),
+      llvm::ConstantStruct::get(CTAType, Fields), MangledName);
+  CTA->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
+  CTA->setSection(".xdata");
+  if (CTA->isWeakForLinker())
+    CTA->setComdat(CGM.getModule().getOrInsertComdat(CTA->getName()));
+  return CTA;
+}
+
+llvm::GlobalVariable *MicrosoftCXXABI::getThrowInfo(QualType T) {
+  bool IsConst, IsVolatile, IsUnaligned;
+  T = decomposeTypeForEH(getContext(), T, IsConst, IsVolatile, IsUnaligned);
+
+  // The CatchableTypeArray enumerates the various (CV-unqualified) types that
+  // the exception object may be caught as.
+  llvm::GlobalVariable *CTA = getCatchableTypeArray(T);
+  // The first field in a CatchableTypeArray is the number of CatchableTypes.
+  // This is used as a component of the mangled name which means that we need to
+  // know what it is in order to see if we have previously generated the
+  // ThrowInfo.
+  uint32_t NumEntries =
+      cast<llvm::ConstantInt>(CTA->getInitializer()->getAggregateElement(0U))
+          ->getLimitedValue();
+
+  SmallString<256> MangledName;
+  {
+    llvm::raw_svector_ostream Out(MangledName);
+    getMangleContext().mangleCXXThrowInfo(T, IsConst, IsVolatile, IsUnaligned,
+                                          NumEntries, Out);
+  }
+
+  // Reuse a previously generated ThrowInfo if we have generated an appropriate
+  // one before.
+  if (llvm::GlobalVariable *GV = CGM.getModule().getNamedGlobal(MangledName))
+    return GV;
+
+  // The RTTI TypeDescriptor uses an unqualified type but catch clauses must
+  // be at least as CV qualified.  Encode this requirement into the Flags
+  // bitfield.
+  uint32_t Flags = 0;
+  if (IsConst)
+    Flags |= 1;
+  if (IsVolatile)
+    Flags |= 2;
+  if (IsUnaligned)
+    Flags |= 4;
+
+  // The cleanup-function (a destructor) must be called when the exception
+  // object's lifetime ends.
+  llvm::Constant *CleanupFn = llvm::Constant::getNullValue(CGM.Int8PtrTy);
+  if (const CXXRecordDecl *RD = T->getAsCXXRecordDecl())
+    if (CXXDestructorDecl *DtorD = RD->getDestructor())
+      if (!DtorD->isTrivial())
+        CleanupFn = llvm::ConstantExpr::getBitCast(
+            CGM.getAddrOfCXXStructor(GlobalDecl(DtorD, Dtor_Complete)),
+            CGM.Int8PtrTy);
+  // This is unused as far as we can tell, initialize it to null.
+  llvm::Constant *ForwardCompat =
+      getImageRelativeConstant(llvm::Constant::getNullValue(CGM.Int8PtrTy));
+  llvm::Constant *PointerToCatchableTypes = getImageRelativeConstant(
+      llvm::ConstantExpr::getBitCast(CTA, CGM.Int8PtrTy));
+  llvm::StructType *TIType = getThrowInfoType();
+  llvm::Constant *Fields[] = {
+      llvm::ConstantInt::get(CGM.IntTy, Flags), // Flags
+      getImageRelativeConstant(CleanupFn),      // CleanupFn
+      ForwardCompat,                            // ForwardCompat
+      PointerToCatchableTypes                   // CatchableTypeArray
+  };
+  auto *GV = new llvm::GlobalVariable(
+      CGM.getModule(), TIType, /*isConstant=*/true, getLinkageForRTTI(T),
+      llvm::ConstantStruct::get(TIType, Fields), StringRef(MangledName));
+  GV->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
+  GV->setSection(".xdata");
+  if (GV->isWeakForLinker())
+    GV->setComdat(CGM.getModule().getOrInsertComdat(GV->getName()));
+  return GV;
+}
+
+void MicrosoftCXXABI::emitThrow(CodeGenFunction &CGF, const CXXThrowExpr *E) {
+  const Expr *SubExpr = E->getSubExpr();
+  QualType ThrowType = SubExpr->getType();
+  // The exception object lives on the stack and it's address is passed to the
+  // runtime function.
+  Address AI = CGF.CreateMemTemp(ThrowType);
+  CGF.EmitAnyExprToMem(SubExpr, AI, ThrowType.getQualifiers(),
+                       /*IsInit=*/true);
+
+  // The so-called ThrowInfo is used to describe how the exception object may be
+  // caught.
+  llvm::GlobalVariable *TI = getThrowInfo(ThrowType);
+
+  // Call into the runtime to throw the exception.
+  llvm::Value *Args[] = {
+    CGF.Builder.CreateBitCast(AI.getPointer(), CGM.Int8PtrTy),
+    TI
+  };
+  CGF.EmitNoreturnRuntimeCallOrInvoke(getThrowFn(), Args);
+}
+
+std::pair<llvm::Value *, const CXXRecordDecl *>
+MicrosoftCXXABI::LoadVTablePtr(CodeGenFunction &CGF, Address This,
+                               const CXXRecordDecl *RD) {
+  std::tie(This, std::ignore, RD) =
+      performBaseAdjustment(CGF, This, QualType(RD->getTypeForDecl(), 0));
+  return {CGF.GetVTablePtr(This, CGM.Int8PtrTy, RD), RD};
+}