Check in LLVM r95781.
diff --git a/lib/CodeGen/CGCXX.cpp b/lib/CodeGen/CGCXX.cpp
new file mode 100644
index 0000000..28c4c6b
--- /dev/null
+++ b/lib/CodeGen/CGCXX.cpp
@@ -0,0 +1,459 @@
+//===--- CGDecl.cpp - Emit LLVM Code for declarations ---------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This contains code dealing with C++ code generation.
+//
+//===----------------------------------------------------------------------===//
+
+// We might split this into multiple files if it gets too unwieldy
+
+#include "CodeGenFunction.h"
+#include "CodeGenModule.h"
+#include "Mangle.h"
+#include "clang/AST/ASTContext.h"
+#include "clang/AST/RecordLayout.h"
+#include "clang/AST/Decl.h"
+#include "clang/AST/DeclCXX.h"
+#include "clang/AST/DeclObjC.h"
+#include "clang/AST/StmtCXX.h"
+#include "llvm/ADT/StringExtras.h"
+using namespace clang;
+using namespace CodeGen;
+
+
+
+llvm::Value *CodeGenFunction::LoadCXXThis() {
+  assert(isa<CXXMethodDecl>(CurFuncDecl) &&
+         "Must be in a C++ member function decl to load 'this'");
+  assert(cast<CXXMethodDecl>(CurFuncDecl)->isInstance() &&
+         "Must be in a C++ member function decl to load 'this'");
+
+  // FIXME: What if we're inside a block?
+  // ans: See how CodeGenFunction::LoadObjCSelf() uses
+  // CodeGenFunction::BlockForwardSelf() for how to do this.
+  return Builder.CreateLoad(LocalDeclMap[CXXThisDecl], "this");
+}
+
+void CodeGenModule::EmitCXXConstructors(const CXXConstructorDecl *D) {
+  EmitGlobal(GlobalDecl(D, Ctor_Complete));
+  EmitGlobal(GlobalDecl(D, Ctor_Base));
+}
+
+void CodeGenModule::EmitCXXConstructor(const CXXConstructorDecl *D,
+                                       CXXCtorType Type) {
+
+  llvm::Function *Fn = GetAddrOfCXXConstructor(D, Type);
+
+  CodeGenFunction(*this).GenerateCode(GlobalDecl(D, Type), Fn);
+
+  SetFunctionDefinitionAttributes(D, Fn);
+  SetLLVMFunctionAttributesForDefinition(D, Fn);
+}
+
+llvm::Function *
+CodeGenModule::GetAddrOfCXXConstructor(const CXXConstructorDecl *D,
+                                       CXXCtorType Type) {
+  const FunctionProtoType *FPT = D->getType()->getAs<FunctionProtoType>();
+  const llvm::FunctionType *FTy =
+    getTypes().GetFunctionType(getTypes().getFunctionInfo(D, Type), 
+                               FPT->isVariadic());
+
+  const char *Name = getMangledCXXCtorName(D, Type);
+  return cast<llvm::Function>(
+                      GetOrCreateLLVMFunction(Name, FTy, GlobalDecl(D, Type)));
+}
+
+const char *CodeGenModule::getMangledCXXCtorName(const CXXConstructorDecl *D,
+                                                 CXXCtorType Type) {
+  llvm::SmallString<256> Name;
+  getMangleContext().mangleCXXCtor(D, Type, Name);
+
+  Name += '\0';
+  return UniqueMangledName(Name.begin(), Name.end());
+}
+
+void CodeGenModule::EmitCXXDestructors(const CXXDestructorDecl *D) {
+  if (D->isVirtual())
+    EmitGlobal(GlobalDecl(D, Dtor_Deleting));
+  EmitGlobal(GlobalDecl(D, Dtor_Complete));
+  EmitGlobal(GlobalDecl(D, Dtor_Base));
+}
+
+void CodeGenModule::EmitCXXDestructor(const CXXDestructorDecl *D,
+                                      CXXDtorType Type) {
+  llvm::Function *Fn = GetAddrOfCXXDestructor(D, Type);
+
+  CodeGenFunction(*this).GenerateCode(GlobalDecl(D, Type), Fn);
+
+  SetFunctionDefinitionAttributes(D, Fn);
+  SetLLVMFunctionAttributesForDefinition(D, Fn);
+}
+
+llvm::Function *
+CodeGenModule::GetAddrOfCXXDestructor(const CXXDestructorDecl *D,
+                                      CXXDtorType Type) {
+  const llvm::FunctionType *FTy =
+    getTypes().GetFunctionType(getTypes().getFunctionInfo(D, Type), false);
+
+  const char *Name = getMangledCXXDtorName(D, Type);
+  return cast<llvm::Function>(
+                      GetOrCreateLLVMFunction(Name, FTy, GlobalDecl(D, Type)));
+}
+
+const char *CodeGenModule::getMangledCXXDtorName(const CXXDestructorDecl *D,
+                                                 CXXDtorType Type) {
+  llvm::SmallString<256> Name;
+  getMangleContext().mangleCXXDtor(D, Type, Name);
+
+  Name += '\0';
+  return UniqueMangledName(Name.begin(), Name.end());
+}
+
+llvm::Constant *
+CodeGenFunction::GenerateThunk(llvm::Function *Fn, GlobalDecl GD,
+                               bool Extern, 
+                               const ThunkAdjustment &ThisAdjustment) {
+  return GenerateCovariantThunk(Fn, GD, Extern,
+                                CovariantThunkAdjustment(ThisAdjustment,
+                                                         ThunkAdjustment()));
+}
+
+llvm::Value *
+CodeGenFunction::DynamicTypeAdjust(llvm::Value *V, 
+                                   const ThunkAdjustment &Adjustment) {
+  const llvm::Type *Int8PtrTy = llvm::Type::getInt8PtrTy(VMContext);
+
+  const llvm::Type *OrigTy = V->getType();
+  if (Adjustment.NonVirtual) {
+    // Do the non-virtual adjustment
+    V = Builder.CreateBitCast(V, Int8PtrTy);
+    V = Builder.CreateConstInBoundsGEP1_64(V, Adjustment.NonVirtual);
+    V = Builder.CreateBitCast(V, OrigTy);
+  }
+  
+  if (!Adjustment.Virtual)
+    return V;
+
+  assert(Adjustment.Virtual % (LLVMPointerWidth / 8) == 0 && 
+         "vtable entry unaligned");
+
+  // Do the virtual this adjustment
+  const llvm::Type *PtrDiffTy = ConvertType(getContext().getPointerDiffType());
+  const llvm::Type *PtrDiffPtrTy = PtrDiffTy->getPointerTo();
+  
+  llvm::Value *ThisVal = Builder.CreateBitCast(V, Int8PtrTy);
+  V = Builder.CreateBitCast(V, PtrDiffPtrTy->getPointerTo());
+  V = Builder.CreateLoad(V, "vtable");
+  
+  llvm::Value *VTablePtr = V;
+  uint64_t VirtualAdjustment = Adjustment.Virtual / (LLVMPointerWidth / 8);
+  V = Builder.CreateConstInBoundsGEP1_64(VTablePtr, VirtualAdjustment);
+  V = Builder.CreateLoad(V);
+  V = Builder.CreateGEP(ThisVal, V);
+  
+  return Builder.CreateBitCast(V, OrigTy);
+}
+
+llvm::Constant *
+CodeGenFunction::GenerateCovariantThunk(llvm::Function *Fn,
+                                   GlobalDecl GD, bool Extern,
+                                   const CovariantThunkAdjustment &Adjustment) {
+  const CXXMethodDecl *MD = cast<CXXMethodDecl>(GD.getDecl());
+  const FunctionProtoType *FPT = MD->getType()->getAs<FunctionProtoType>();
+  QualType ResultType = FPT->getResultType();
+
+  FunctionArgList Args;
+  ImplicitParamDecl *ThisDecl =
+    ImplicitParamDecl::Create(getContext(), 0, SourceLocation(), 0,
+                              MD->getThisType(getContext()));
+  Args.push_back(std::make_pair(ThisDecl, ThisDecl->getType()));
+  for (FunctionDecl::param_const_iterator i = MD->param_begin(),
+         e = MD->param_end();
+       i != e; ++i) {
+    ParmVarDecl *D = *i;
+    Args.push_back(std::make_pair(D, D->getType()));
+  }
+  IdentifierInfo *II
+    = &CGM.getContext().Idents.get("__thunk_named_foo_");
+  FunctionDecl *FD = FunctionDecl::Create(getContext(),
+                                          getContext().getTranslationUnitDecl(),
+                                          SourceLocation(), II, ResultType, 0,
+                                          Extern
+                                            ? FunctionDecl::Extern
+                                            : FunctionDecl::Static,
+                                          false, true);
+  StartFunction(FD, ResultType, Fn, Args, SourceLocation());
+
+  // generate body
+  const llvm::Type *Ty =
+    CGM.getTypes().GetFunctionType(CGM.getTypes().getFunctionInfo(MD),
+                                   FPT->isVariadic());
+  llvm::Value *Callee = CGM.GetAddrOfFunction(GD, Ty);
+
+  CallArgList CallArgs;
+
+  bool ShouldAdjustReturnPointer = true;
+  QualType ArgType = MD->getThisType(getContext());
+  llvm::Value *Arg = Builder.CreateLoad(LocalDeclMap[ThisDecl], "this");
+  if (!Adjustment.ThisAdjustment.isEmpty()) {
+    // Do the this adjustment.
+    const llvm::Type *OrigTy = Callee->getType();
+    Arg = DynamicTypeAdjust(Arg, Adjustment.ThisAdjustment);
+    
+    if (!Adjustment.ReturnAdjustment.isEmpty()) {
+      const CovariantThunkAdjustment &ReturnAdjustment = 
+        CovariantThunkAdjustment(ThunkAdjustment(),
+                                 Adjustment.ReturnAdjustment);
+      
+      Callee = CGM.BuildCovariantThunk(GD, Extern, ReturnAdjustment);
+      
+      Callee = Builder.CreateBitCast(Callee, OrigTy);
+      ShouldAdjustReturnPointer = false;
+    }
+  }    
+
+  CallArgs.push_back(std::make_pair(RValue::get(Arg), ArgType));
+
+  for (FunctionDecl::param_const_iterator i = MD->param_begin(),
+         e = MD->param_end();
+       i != e; ++i) {
+    ParmVarDecl *D = *i;
+    QualType ArgType = D->getType();
+
+    // llvm::Value *Arg = CGF.GetAddrOfLocalVar(Dst);
+    Expr *Arg = new (getContext()) DeclRefExpr(D, ArgType.getNonReferenceType(),
+                                               SourceLocation());
+    CallArgs.push_back(std::make_pair(EmitCallArg(Arg, ArgType), ArgType));
+  }
+
+  RValue RV = EmitCall(CGM.getTypes().getFunctionInfo(ResultType, CallArgs,
+                                                      FPT->getCallConv(),
+                                                      FPT->getNoReturnAttr()),
+                       Callee, ReturnValueSlot(), CallArgs, MD);
+  if (ShouldAdjustReturnPointer && !Adjustment.ReturnAdjustment.isEmpty()) {
+    bool CanBeZero = !(ResultType->isReferenceType()
+    // FIXME: attr nonnull can't be zero either
+                       /* || ResultType->hasAttr<NonNullAttr>() */ );
+    // Do the return result adjustment.
+    if (CanBeZero) {
+      llvm::BasicBlock *NonZeroBlock = createBasicBlock();
+      llvm::BasicBlock *ZeroBlock = createBasicBlock();
+      llvm::BasicBlock *ContBlock = createBasicBlock();
+
+      const llvm::Type *Ty = RV.getScalarVal()->getType();
+      llvm::Value *Zero = llvm::Constant::getNullValue(Ty);
+      Builder.CreateCondBr(Builder.CreateICmpNE(RV.getScalarVal(), Zero),
+                           NonZeroBlock, ZeroBlock);
+      EmitBlock(NonZeroBlock);
+      llvm::Value *NZ = 
+        DynamicTypeAdjust(RV.getScalarVal(), Adjustment.ReturnAdjustment);
+      EmitBranch(ContBlock);
+      EmitBlock(ZeroBlock);
+      llvm::Value *Z = RV.getScalarVal();
+      EmitBlock(ContBlock);
+      llvm::PHINode *RVOrZero = Builder.CreatePHI(Ty);
+      RVOrZero->reserveOperandSpace(2);
+      RVOrZero->addIncoming(NZ, NonZeroBlock);
+      RVOrZero->addIncoming(Z, ZeroBlock);
+      RV = RValue::get(RVOrZero);
+    } else
+      RV = RValue::get(DynamicTypeAdjust(RV.getScalarVal(), 
+                                         Adjustment.ReturnAdjustment));
+  }
+
+  if (!ResultType->isVoidType())
+    EmitReturnOfRValue(RV, ResultType);
+
+  FinishFunction();
+  return Fn;
+}
+
+llvm::Constant *
+CodeGenModule::GetAddrOfThunk(GlobalDecl GD,
+                              const ThunkAdjustment &ThisAdjustment) {
+  const CXXMethodDecl *MD = cast<CXXMethodDecl>(GD.getDecl());
+
+  // Compute mangled name
+  llvm::SmallString<256> OutName;
+  if (const CXXDestructorDecl* DD = dyn_cast<CXXDestructorDecl>(MD))
+    getMangleContext().mangleCXXDtorThunk(DD, GD.getDtorType(), ThisAdjustment,
+                                          OutName);
+  else
+    getMangleContext().mangleThunk(MD, ThisAdjustment, OutName);
+  OutName += '\0';
+  const char* Name = UniqueMangledName(OutName.begin(), OutName.end());
+
+  // Get function for mangled name
+  const llvm::Type *Ty = getTypes().GetFunctionTypeForVtable(MD);
+  return GetOrCreateLLVMFunction(Name, Ty, GlobalDecl());
+}
+
+llvm::Constant *
+CodeGenModule::GetAddrOfCovariantThunk(GlobalDecl GD,
+                                   const CovariantThunkAdjustment &Adjustment) {
+  const CXXMethodDecl *MD = cast<CXXMethodDecl>(GD.getDecl());
+
+  // Compute mangled name
+  llvm::SmallString<256> OutName;
+  getMangleContext().mangleCovariantThunk(MD, Adjustment, OutName);
+  OutName += '\0';
+  const char* Name = UniqueMangledName(OutName.begin(), OutName.end());
+
+  // Get function for mangled name
+  const llvm::Type *Ty = getTypes().GetFunctionTypeForVtable(MD);
+  return GetOrCreateLLVMFunction(Name, Ty, GlobalDecl());
+}
+
+void CodeGenModule::BuildThunksForVirtual(GlobalDecl GD) {
+  CGVtableInfo::AdjustmentVectorTy *AdjPtr = getVtableInfo().getAdjustments(GD);
+  if (!AdjPtr)
+    return;
+  CGVtableInfo::AdjustmentVectorTy &Adj = *AdjPtr;
+  const CXXMethodDecl *MD = cast<CXXMethodDecl>(GD.getDecl());
+  for (unsigned i = 0; i < Adj.size(); i++) {
+    GlobalDecl OGD = Adj[i].first;
+    const CXXMethodDecl *OMD = cast<CXXMethodDecl>(OGD.getDecl());
+    QualType nc_oret = OMD->getType()->getAs<FunctionType>()->getResultType();
+    CanQualType oret = getContext().getCanonicalType(nc_oret);
+    QualType nc_ret = MD->getType()->getAs<FunctionType>()->getResultType();
+    CanQualType ret = getContext().getCanonicalType(nc_ret);
+    ThunkAdjustment ReturnAdjustment;
+    if (oret != ret) {
+      QualType qD = nc_ret->getPointeeType();
+      QualType qB = nc_oret->getPointeeType();
+      CXXRecordDecl *D = cast<CXXRecordDecl>(qD->getAs<RecordType>()->getDecl());
+      CXXRecordDecl *B = cast<CXXRecordDecl>(qB->getAs<RecordType>()->getDecl());
+      ReturnAdjustment = ComputeThunkAdjustment(D, B);
+    }
+    ThunkAdjustment ThisAdjustment = Adj[i].second;
+    bool Extern = !cast<CXXRecordDecl>(OMD->getDeclContext())->isInAnonymousNamespace();
+    if (!ReturnAdjustment.isEmpty() || !ThisAdjustment.isEmpty()) {
+      CovariantThunkAdjustment CoAdj(ThisAdjustment, ReturnAdjustment);
+      llvm::Constant *FnConst;
+      if (!ReturnAdjustment.isEmpty())
+        FnConst = GetAddrOfCovariantThunk(GD, CoAdj);
+      else
+        FnConst = GetAddrOfThunk(GD, ThisAdjustment);
+      if (!isa<llvm::Function>(FnConst)) {
+        llvm::Constant *SubExpr =
+            cast<llvm::ConstantExpr>(FnConst)->getOperand(0);
+        llvm::Function *OldFn = cast<llvm::Function>(SubExpr);
+        std::string Name = OldFn->getNameStr();
+        GlobalDeclMap.erase(UniqueMangledName(Name.data(),
+                                              Name.data() + Name.size() + 1));
+        llvm::Constant *NewFnConst;
+        if (!ReturnAdjustment.isEmpty())
+          NewFnConst = GetAddrOfCovariantThunk(GD, CoAdj);
+        else
+          NewFnConst = GetAddrOfThunk(GD, ThisAdjustment);
+        llvm::Function *NewFn = cast<llvm::Function>(NewFnConst);
+        NewFn->takeName(OldFn);
+        llvm::Constant *NewPtrForOldDecl =
+            llvm::ConstantExpr::getBitCast(NewFn, OldFn->getType());
+        OldFn->replaceAllUsesWith(NewPtrForOldDecl);
+        OldFn->eraseFromParent();
+        FnConst = NewFn;
+      }
+      llvm::Function *Fn = cast<llvm::Function>(FnConst);
+      if (Fn->isDeclaration()) {
+        llvm::GlobalVariable::LinkageTypes linktype;
+        linktype = llvm::GlobalValue::WeakAnyLinkage;
+        if (!Extern)
+          linktype = llvm::GlobalValue::InternalLinkage;
+        Fn->setLinkage(linktype);
+        if (!Features.Exceptions && !Features.ObjCNonFragileABI)
+          Fn->addFnAttr(llvm::Attribute::NoUnwind);
+        Fn->setAlignment(2);
+        CodeGenFunction(*this).GenerateCovariantThunk(Fn, GD, Extern, CoAdj);
+      }
+    }
+  }
+}
+
+llvm::Constant *
+CodeGenModule::BuildThunk(GlobalDecl GD, bool Extern,
+                          const ThunkAdjustment &ThisAdjustment) {
+  const CXXMethodDecl *MD = cast<CXXMethodDecl>(GD.getDecl());
+  llvm::SmallString<256> OutName;
+  if (const CXXDestructorDecl *D = dyn_cast<CXXDestructorDecl>(MD)) {
+    getMangleContext().mangleCXXDtorThunk(D, GD.getDtorType(), ThisAdjustment,
+                                          OutName);
+  } else 
+    getMangleContext().mangleThunk(MD, ThisAdjustment, OutName);
+  
+  llvm::GlobalVariable::LinkageTypes linktype;
+  linktype = llvm::GlobalValue::WeakAnyLinkage;
+  if (!Extern)
+    linktype = llvm::GlobalValue::InternalLinkage;
+  llvm::Type *Ptr8Ty=llvm::PointerType::get(llvm::Type::getInt8Ty(VMContext),0);
+  const FunctionProtoType *FPT = MD->getType()->getAs<FunctionProtoType>();
+  const llvm::FunctionType *FTy =
+    getTypes().GetFunctionType(getTypes().getFunctionInfo(MD),
+                               FPT->isVariadic());
+
+  llvm::Function *Fn = llvm::Function::Create(FTy, linktype, OutName.str(),
+                                              &getModule());
+  CodeGenFunction(*this).GenerateThunk(Fn, GD, Extern, ThisAdjustment);
+  llvm::Constant *m = llvm::ConstantExpr::getBitCast(Fn, Ptr8Ty);
+  return m;
+}
+
+llvm::Constant *
+CodeGenModule::BuildCovariantThunk(const GlobalDecl &GD, bool Extern,
+                                   const CovariantThunkAdjustment &Adjustment) {
+  const CXXMethodDecl *MD = cast<CXXMethodDecl>(GD.getDecl());
+  llvm::SmallString<256> OutName;
+  getMangleContext().mangleCovariantThunk(MD, Adjustment, OutName);
+  llvm::GlobalVariable::LinkageTypes linktype;
+  linktype = llvm::GlobalValue::WeakAnyLinkage;
+  if (!Extern)
+    linktype = llvm::GlobalValue::InternalLinkage;
+  llvm::Type *Ptr8Ty=llvm::PointerType::get(llvm::Type::getInt8Ty(VMContext),0);
+  const FunctionProtoType *FPT = MD->getType()->getAs<FunctionProtoType>();
+  const llvm::FunctionType *FTy =
+    getTypes().GetFunctionType(getTypes().getFunctionInfo(MD),
+                               FPT->isVariadic());
+
+  llvm::Function *Fn = llvm::Function::Create(FTy, linktype, OutName.str(),
+                                              &getModule());
+  CodeGenFunction(*this).GenerateCovariantThunk(Fn, MD, Extern, Adjustment);
+  llvm::Constant *m = llvm::ConstantExpr::getBitCast(Fn, Ptr8Ty);
+  return m;
+}
+
+static llvm::Value *BuildVirtualCall(CodeGenFunction &CGF, uint64_t VtableIndex, 
+                                     llvm::Value *This, const llvm::Type *Ty) {
+  Ty = Ty->getPointerTo()->getPointerTo()->getPointerTo();
+  
+  llvm::Value *Vtable = CGF.Builder.CreateBitCast(This, Ty);
+  Vtable = CGF.Builder.CreateLoad(Vtable);
+  
+  llvm::Value *VFuncPtr = 
+    CGF.Builder.CreateConstInBoundsGEP1_64(Vtable, VtableIndex, "vfn");
+  return CGF.Builder.CreateLoad(VFuncPtr);
+}
+
+llvm::Value *
+CodeGenFunction::BuildVirtualCall(const CXXMethodDecl *MD, llvm::Value *This,
+                                  const llvm::Type *Ty) {
+  MD = MD->getCanonicalDecl();
+  uint64_t VtableIndex = CGM.getVtableInfo().getMethodVtableIndex(MD);
+  
+  return ::BuildVirtualCall(*this, VtableIndex, This, Ty);
+}
+
+llvm::Value *
+CodeGenFunction::BuildVirtualCall(const CXXDestructorDecl *DD, CXXDtorType Type, 
+                                  llvm::Value *&This, const llvm::Type *Ty) {
+  DD = cast<CXXDestructorDecl>(DD->getCanonicalDecl());
+  uint64_t VtableIndex = 
+    CGM.getVtableInfo().getMethodVtableIndex(GlobalDecl(DD, Type));
+
+  return ::BuildVirtualCall(*this, VtableIndex, This, Ty);
+}