Add the clang library to the repo (with some of my changes, too).

1 files changed, 2974 insertions, 0 deletions

diff --git a/clang/lib/CodeGen/CGObjC.cpp b/clang/lib/CodeGen/CGObjC.cpp
new file mode 100644
index 0000000..d0aa0f5
--- /dev/null
+++ b/clang/lib/CodeGen/CGObjC.cpp
@@ -0,0 +1,2974 @@
+//===---- CGBuiltin.cpp - Emit LLVM Code for builtins ---------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This contains code to emit Objective-C code as LLVM code.
+//
+//===----------------------------------------------------------------------===//
+
+#include "CGDebugInfo.h"
+#include "CGObjCRuntime.h"
+#include "CodeGenFunction.h"
+#include "CodeGenModule.h"
+#include "TargetInfo.h"
+#include "clang/AST/ASTContext.h"
+#include "clang/AST/DeclObjC.h"
+#include "clang/AST/StmtObjC.h"
+#include "clang/Basic/Diagnostic.h"
+#include "llvm/ADT/STLExtras.h"
+#include "llvm/Target/TargetData.h"
+#include "llvm/InlineAsm.h"
+using namespace clang;
+using namespace CodeGen;
+
+typedef llvm::PointerIntPair<llvm::Value*,1,bool> TryEmitResult;
+static TryEmitResult
+tryEmitARCRetainScalarExpr(CodeGenFunction &CGF, const Expr *e);
+static RValue AdjustRelatedResultType(CodeGenFunction &CGF,
+                                      const Expr *E,
+                                      const ObjCMethodDecl *Method,
+                                      RValue Result);
+
+/// Given the address of a variable of pointer type, find the correct
+/// null to store into it.
+static llvm::Constant *getNullForVariable(llvm::Value *addr) {
+  llvm::Type *type =
+    cast<llvm::PointerType>(addr->getType())->getElementType();
+  return llvm::ConstantPointerNull::get(cast<llvm::PointerType>(type));
+}
+
+/// Emits an instance of NSConstantString representing the object.
+llvm::Value *CodeGenFunction::EmitObjCStringLiteral(const ObjCStringLiteral *E)
+{
+  llvm::Constant *C = 
+      CGM.getObjCRuntime().GenerateConstantString(E->getString());
+  // FIXME: This bitcast should just be made an invariant on the Runtime.
+  return llvm::ConstantExpr::getBitCast(C, ConvertType(E->getType()));
+}
+
+/// EmitObjCNumericLiteral - This routine generates code for
+/// the appropriate +[NSNumber numberWith<Type>:] method.
+///
+llvm::Value *
+CodeGenFunction::EmitObjCNumericLiteral(const ObjCNumericLiteral *E) {
+  // Generate the correct selector for this literal's concrete type.
+  const Expr *NL = E->getNumber();
+  // Get the method.
+  const ObjCMethodDecl *Method = E->getObjCNumericLiteralMethod();
+  assert(Method && "NSNumber method is null");
+  Selector Sel = Method->getSelector();
+  
+  // Generate a reference to the class pointer, which will be the receiver.
+  QualType ResultType = E->getType(); // should be NSNumber *
+  const ObjCObjectPointerType *InterfacePointerType = 
+    ResultType->getAsObjCInterfacePointerType();
+  ObjCInterfaceDecl *NSNumberDecl = 
+    InterfacePointerType->getObjectType()->getInterface();
+  CGObjCRuntime &Runtime = CGM.getObjCRuntime();
+  llvm::Value *Receiver = Runtime.GetClass(Builder, NSNumberDecl);
+
+  const ParmVarDecl *argDecl = *Method->param_begin();
+  QualType ArgQT = argDecl->getType().getUnqualifiedType();
+  RValue RV = EmitAnyExpr(NL);
+  CallArgList Args;
+  Args.add(RV, ArgQT);
+
+  RValue result = Runtime.GenerateMessageSend(*this, ReturnValueSlot(), 
+                                              ResultType, Sel, Receiver, Args, 
+                                              NSNumberDecl, Method);
+  return Builder.CreateBitCast(result.getScalarVal(), 
+                               ConvertType(E->getType()));
+}
+
+llvm::Value *CodeGenFunction::EmitObjCCollectionLiteral(const Expr *E,
+                                    const ObjCMethodDecl *MethodWithObjects) {
+  ASTContext &Context = CGM.getContext();
+  const ObjCDictionaryLiteral *DLE = 0;
+  const ObjCArrayLiteral *ALE = dyn_cast<ObjCArrayLiteral>(E);
+  if (!ALE)
+    DLE = cast<ObjCDictionaryLiteral>(E);
+  
+  // Compute the type of the array we're initializing.
+  uint64_t NumElements = 
+    ALE ? ALE->getNumElements() : DLE->getNumElements();
+  llvm::APInt APNumElements(Context.getTypeSize(Context.getSizeType()),
+                            NumElements);
+  QualType ElementType = Context.getObjCIdType().withConst();
+  QualType ElementArrayType 
+    = Context.getConstantArrayType(ElementType, APNumElements, 
+                                   ArrayType::Normal, /*IndexTypeQuals=*/0);
+
+  // Allocate the temporary array(s).
+  llvm::Value *Objects = CreateMemTemp(ElementArrayType, "objects");  
+  llvm::Value *Keys = 0;
+  if (DLE)
+    Keys = CreateMemTemp(ElementArrayType, "keys");
+  
+  // Perform the actual initialialization of the array(s).
+  for (uint64_t i = 0; i < NumElements; i++) {
+    if (ALE) {
+      // Emit the initializer.
+      const Expr *Rhs = ALE->getElement(i);
+      LValue LV = LValue::MakeAddr(Builder.CreateStructGEP(Objects, i),
+                                   ElementType,
+                                   Context.getTypeAlignInChars(Rhs->getType()),
+                                   Context);
+      EmitScalarInit(Rhs, /*D=*/0, LV, /*capturedByInit=*/false);
+    } else {      
+      // Emit the key initializer.
+      const Expr *Key = DLE->getKeyValueElement(i).Key;
+      LValue KeyLV = LValue::MakeAddr(Builder.CreateStructGEP(Keys, i),
+                                      ElementType,
+                                    Context.getTypeAlignInChars(Key->getType()),
+                                      Context);
+      EmitScalarInit(Key, /*D=*/0, KeyLV, /*capturedByInit=*/false);
+
+      // Emit the value initializer.
+      const Expr *Value = DLE->getKeyValueElement(i).Value;  
+      LValue ValueLV = LValue::MakeAddr(Builder.CreateStructGEP(Objects, i), 
+                                        ElementType,
+                                  Context.getTypeAlignInChars(Value->getType()),
+                                        Context);
+      EmitScalarInit(Value, /*D=*/0, ValueLV, /*capturedByInit=*/false);
+    }
+  }
+  
+  // Generate the argument list.
+  CallArgList Args;  
+  ObjCMethodDecl::param_const_iterator PI = MethodWithObjects->param_begin();
+  const ParmVarDecl *argDecl = *PI++;
+  QualType ArgQT = argDecl->getType().getUnqualifiedType();
+  Args.add(RValue::get(Objects), ArgQT);
+  if (DLE) {
+    argDecl = *PI++;
+    ArgQT = argDecl->getType().getUnqualifiedType();
+    Args.add(RValue::get(Keys), ArgQT);
+  }
+  argDecl = *PI;
+  ArgQT = argDecl->getType().getUnqualifiedType();
+  llvm::Value *Count = 
+    llvm::ConstantInt::get(CGM.getTypes().ConvertType(ArgQT), NumElements);
+  Args.add(RValue::get(Count), ArgQT);
+
+  // Generate a reference to the class pointer, which will be the receiver.
+  Selector Sel = MethodWithObjects->getSelector();
+  QualType ResultType = E->getType();
+  const ObjCObjectPointerType *InterfacePointerType
+    = ResultType->getAsObjCInterfacePointerType();
+  ObjCInterfaceDecl *Class 
+    = InterfacePointerType->getObjectType()->getInterface();
+  CGObjCRuntime &Runtime = CGM.getObjCRuntime();
+  llvm::Value *Receiver = Runtime.GetClass(Builder, Class);
+
+  // Generate the message send.
+  RValue result
+    = Runtime.GenerateMessageSend(*this, ReturnValueSlot(), 
+                                  MethodWithObjects->getResultType(),
+                                  Sel,
+                                  Receiver, Args, Class,
+                                  MethodWithObjects);
+  return Builder.CreateBitCast(result.getScalarVal(), 
+                               ConvertType(E->getType()));
+}
+
+llvm::Value *CodeGenFunction::EmitObjCArrayLiteral(const ObjCArrayLiteral *E) {
+  return EmitObjCCollectionLiteral(E, E->getArrayWithObjectsMethod());
+}
+
+llvm::Value *CodeGenFunction::EmitObjCDictionaryLiteral(
+                                            const ObjCDictionaryLiteral *E) {
+  return EmitObjCCollectionLiteral(E, E->getDictWithObjectsMethod());
+}
+
+/// Emit a selector.
+llvm::Value *CodeGenFunction::EmitObjCSelectorExpr(const ObjCSelectorExpr *E) {
+  // Untyped selector.
+  // Note that this implementation allows for non-constant strings to be passed
+  // as arguments to @selector().  Currently, the only thing preventing this
+  // behaviour is the type checking in the front end.
+  return CGM.getObjCRuntime().GetSelector(Builder, E->getSelector());
+}
+
+llvm::Value *CodeGenFunction::EmitObjCProtocolExpr(const ObjCProtocolExpr *E) {
+  // FIXME: This should pass the Decl not the name.
+  return CGM.getObjCRuntime().GenerateProtocolRef(Builder, E->getProtocol());
+}
+
+/// \brief Adjust the type of the result of an Objective-C message send 
+/// expression when the method has a related result type.
+static RValue AdjustRelatedResultType(CodeGenFunction &CGF,
+                                      const Expr *E,
+                                      const ObjCMethodDecl *Method,
+                                      RValue Result) {
+  if (!Method)
+    return Result;
+
+  if (!Method->hasRelatedResultType() ||
+      CGF.getContext().hasSameType(E->getType(), Method->getResultType()) ||
+      !Result.isScalar())
+    return Result;
+  
+  // We have applied a related result type. Cast the rvalue appropriately.
+  return RValue::get(CGF.Builder.CreateBitCast(Result.getScalarVal(),
+                                               CGF.ConvertType(E->getType())));
+}
+
+/// Decide whether to extend the lifetime of the receiver of a
+/// returns-inner-pointer message.
+static bool
+shouldExtendReceiverForInnerPointerMessage(const ObjCMessageExpr *message) {
+  switch (message->getReceiverKind()) {
+
+  // For a normal instance message, we should extend unless the
+  // receiver is loaded from a variable with precise lifetime.
+  case ObjCMessageExpr::Instance: {
+    const Expr *receiver = message->getInstanceReceiver();
+    const ImplicitCastExpr *ice = dyn_cast<ImplicitCastExpr>(receiver);
+    if (!ice || ice->getCastKind() != CK_LValueToRValue) return true;
+    receiver = ice->getSubExpr()->IgnoreParens();
+
+    // Only __strong variables.
+    if (receiver->getType().getObjCLifetime() != Qualifiers::OCL_Strong)
+      return true;
+
+    // All ivars and fields have precise lifetime.
+    if (isa<MemberExpr>(receiver) || isa<ObjCIvarRefExpr>(receiver))
+      return false;
+
+    // Otherwise, check for variables.
+    const DeclRefExpr *declRef = dyn_cast<DeclRefExpr>(ice->getSubExpr());
+    if (!declRef) return true;
+    const VarDecl *var = dyn_cast<VarDecl>(declRef->getDecl());
+    if (!var) return true;
+
+    // All variables have precise lifetime except local variables with
+    // automatic storage duration that aren't specially marked.
+    return (var->hasLocalStorage() &&
+            !var->hasAttr<ObjCPreciseLifetimeAttr>());
+  }
+
+  case ObjCMessageExpr::Class:
+  case ObjCMessageExpr::SuperClass:
+    // It's never necessary for class objects.
+    return false;
+
+  case ObjCMessageExpr::SuperInstance:
+    // We generally assume that 'self' lives throughout a method call.
+    return false;
+  }
+
+  llvm_unreachable("invalid receiver kind");
+}
+
+RValue CodeGenFunction::EmitObjCMessageExpr(const ObjCMessageExpr *E,
+                                            ReturnValueSlot Return) {
+  // Only the lookup mechanism and first two arguments of the method
+  // implementation vary between runtimes.  We can get the receiver and
+  // arguments in generic code.
+
+  bool isDelegateInit = E->isDelegateInitCall();
+
+  const ObjCMethodDecl *method = E->getMethodDecl();
+
+  // We don't retain the receiver in delegate init calls, and this is
+  // safe because the receiver value is always loaded from 'self',
+  // which we zero out.  We don't want to Block_copy block receivers,
+  // though.
+  bool retainSelf =
+    (!isDelegateInit &&
+     CGM.getLangOpts().ObjCAutoRefCount &&
+     method &&
+     method->hasAttr<NSConsumesSelfAttr>());
+
+  CGObjCRuntime &Runtime = CGM.getObjCRuntime();
+  bool isSuperMessage = false;
+  bool isClassMessage = false;
+  ObjCInterfaceDecl *OID = 0;
+  // Find the receiver
+  QualType ReceiverType;
+  llvm::Value *Receiver = 0;
+  switch (E->getReceiverKind()) {
+  case ObjCMessageExpr::Instance:
+    ReceiverType = E->getInstanceReceiver()->getType();
+    if (retainSelf) {
+      TryEmitResult ter = tryEmitARCRetainScalarExpr(*this,
+                                                   E->getInstanceReceiver());
+      Receiver = ter.getPointer();
+      if (ter.getInt()) retainSelf = false;
+    } else
+      Receiver = EmitScalarExpr(E->getInstanceReceiver());
+    break;
+
+  case ObjCMessageExpr::Class: {
+    ReceiverType = E->getClassReceiver();
+    const ObjCObjectType *ObjTy = ReceiverType->getAs<ObjCObjectType>();
+    assert(ObjTy && "Invalid Objective-C class message send");
+    OID = ObjTy->getInterface();
+    assert(OID && "Invalid Objective-C class message send");
+    Receiver = Runtime.GetClass(Builder, OID);
+    isClassMessage = true;
+    break;
+  }
+
+  case ObjCMessageExpr::SuperInstance:
+    ReceiverType = E->getSuperType();
+    Receiver = LoadObjCSelf();
+    isSuperMessage = true;
+    break;
+
+  case ObjCMessageExpr::SuperClass:
+    ReceiverType = E->getSuperType();
+    Receiver = LoadObjCSelf();
+    isSuperMessage = true;
+    isClassMessage = true;
+    break;
+  }
+
+  if (retainSelf)
+    Receiver = EmitARCRetainNonBlock(Receiver);
+
+  // In ARC, we sometimes want to "extend the lifetime"
+  // (i.e. retain+autorelease) of receivers of returns-inner-pointer
+  // messages.
+  if (getLangOpts().ObjCAutoRefCount && method &&
+      method->hasAttr<ObjCReturnsInnerPointerAttr>() &&
+      shouldExtendReceiverForInnerPointerMessage(E))
+    Receiver = EmitARCRetainAutorelease(ReceiverType, Receiver);
+
+  QualType ResultType =
+    method ? method->getResultType() : E->getType();
+
+  CallArgList Args;
+  EmitCallArgs(Args, method, E->arg_begin(), E->arg_end());
+
+  // For delegate init calls in ARC, do an unsafe store of null into
+  // self.  This represents the call taking direct ownership of that
+  // value.  We have to do this after emitting the other call
+  // arguments because they might also reference self, but we don't
+  // have to worry about any of them modifying self because that would
+  // be an undefined read and write of an object in unordered
+  // expressions.
+  if (isDelegateInit) {
+    assert(getLangOpts().ObjCAutoRefCount &&
+           "delegate init calls should only be marked in ARC");
+
+    // Do an unsafe store of null into self.
+    llvm::Value *selfAddr =
+      LocalDeclMap[cast<ObjCMethodDecl>(CurCodeDecl)->getSelfDecl()];
+    assert(selfAddr && "no self entry for a delegate init call?");
+
+    Builder.CreateStore(getNullForVariable(selfAddr), selfAddr);
+  }
+
+  RValue result;
+  if (isSuperMessage) {
+    // super is only valid in an Objective-C method
+    const ObjCMethodDecl *OMD = cast<ObjCMethodDecl>(CurFuncDecl);
+    bool isCategoryImpl = isa<ObjCCategoryImplDecl>(OMD->getDeclContext());
+    result = Runtime.GenerateMessageSendSuper(*this, Return, ResultType,
+                                              E->getSelector(),
+                                              OMD->getClassInterface(),
+                                              isCategoryImpl,
+                                              Receiver,
+                                              isClassMessage,
+                                              Args,
+                                              method);
+  } else {
+    result = Runtime.GenerateMessageSend(*this, Return, ResultType,
+                                         E->getSelector(),
+                                         Receiver, Args, OID,
+                                         method);
+  }
+
+  // For delegate init calls in ARC, implicitly store the result of
+  // the call back into self.  This takes ownership of the value.
+  if (isDelegateInit) {
+    llvm::Value *selfAddr =
+      LocalDeclMap[cast<ObjCMethodDecl>(CurCodeDecl)->getSelfDecl()];
+    llvm::Value *newSelf = result.getScalarVal();
+
+    // The delegate return type isn't necessarily a matching type; in
+    // fact, it's quite likely to be 'id'.
+    llvm::Type *selfTy =
+      cast<llvm::PointerType>(selfAddr->getType())->getElementType();
+    newSelf = Builder.CreateBitCast(newSelf, selfTy);
+
+    Builder.CreateStore(newSelf, selfAddr);
+  }
+
+  return AdjustRelatedResultType(*this, E, method, result);
+}
+
+namespace {
+struct FinishARCDealloc : EHScopeStack::Cleanup {
+  void Emit(CodeGenFunction &CGF, Flags flags) {
+    const ObjCMethodDecl *method = cast<ObjCMethodDecl>(CGF.CurCodeDecl);
+
+    const ObjCImplDecl *impl = cast<ObjCImplDecl>(method->getDeclContext());
+    const ObjCInterfaceDecl *iface = impl->getClassInterface();
+    if (!iface->getSuperClass()) return;
+
+    bool isCategory = isa<ObjCCategoryImplDecl>(impl);
+
+    // Call [super dealloc] if we have a superclass.
+    llvm::Value *self = CGF.LoadObjCSelf();
+
+    CallArgList args;
+    CGF.CGM.getObjCRuntime().GenerateMessageSendSuper(CGF, ReturnValueSlot(),
+                                                      CGF.getContext().VoidTy,
+                                                      method->getSelector(),
+                                                      iface,
+                                                      isCategory,
+                                                      self,
+                                                      /*is class msg*/ false,
+                                                      args,
+                                                      method);
+  }
+};
+}
+
+/// StartObjCMethod - Begin emission of an ObjCMethod. This generates
+/// the LLVM function and sets the other context used by
+/// CodeGenFunction.
+void CodeGenFunction::StartObjCMethod(const ObjCMethodDecl *OMD,
+                                      const ObjCContainerDecl *CD,
+                                      SourceLocation StartLoc) {
+  FunctionArgList args;
+  // Check if we should generate debug info for this method.
+  if (CGM.getModuleDebugInfo() && !OMD->hasAttr<NoDebugAttr>())
+    DebugInfo = CGM.getModuleDebugInfo();
+
+  llvm::Function *Fn = CGM.getObjCRuntime().GenerateMethod(OMD, CD);
+
+  const CGFunctionInfo &FI = CGM.getTypes().arrangeObjCMethodDeclaration(OMD);
+  CGM.SetInternalFunctionAttributes(OMD, Fn, FI);
+
+  args.push_back(OMD->getSelfDecl());
+  args.push_back(OMD->getCmdDecl());
+
+  for (ObjCMethodDecl::param_const_iterator PI = OMD->param_begin(),
+         E = OMD->param_end(); PI != E; ++PI)
+    args.push_back(*PI);
+
+  CurGD = OMD;
+
+  StartFunction(OMD, OMD->getResultType(), Fn, FI, args, StartLoc);
+
+  // In ARC, certain methods get an extra cleanup.
+  if (CGM.getLangOpts().ObjCAutoRefCount &&
+      OMD->isInstanceMethod() &&
+      OMD->getSelector().isUnarySelector()) {
+    const IdentifierInfo *ident = 
+      OMD->getSelector().getIdentifierInfoForSlot(0);
+    if (ident->isStr("dealloc"))
+      EHStack.pushCleanup<FinishARCDealloc>(getARCCleanupKind());
+  }
+}
+
+static llvm::Value *emitARCRetainLoadOfScalar(CodeGenFunction &CGF,
+                                              LValue lvalue, QualType type);
+
+/// Generate an Objective-C method.  An Objective-C method is a C function with
+/// its pointer, name, and types registered in the class struture.
+void CodeGenFunction::GenerateObjCMethod(const ObjCMethodDecl *OMD) {
+  StartObjCMethod(OMD, OMD->getClassInterface(), OMD->getLocStart());
+  EmitStmt(OMD->getBody());
+  FinishFunction(OMD->getBodyRBrace());
+}
+
+/// emitStructGetterCall - Call the runtime function to load a property
+/// into the return value slot.
+static void emitStructGetterCall(CodeGenFunction &CGF, ObjCIvarDecl *ivar, 
+                                 bool isAtomic, bool hasStrong) {
+  ASTContext &Context = CGF.getContext();
+
+  llvm::Value *src =
+    CGF.EmitLValueForIvar(CGF.TypeOfSelfObject(), CGF.LoadObjCSelf(),
+                          ivar, 0).getAddress();
+
+  // objc_copyStruct (ReturnValue, &structIvar, 
+  //                  sizeof (Type of Ivar), isAtomic, false);
+  CallArgList args;
+
+  llvm::Value *dest = CGF.Builder.CreateBitCast(CGF.ReturnValue, CGF.VoidPtrTy);
+  args.add(RValue::get(dest), Context.VoidPtrTy);
+
+  src = CGF.Builder.CreateBitCast(src, CGF.VoidPtrTy);
+  args.add(RValue::get(src), Context.VoidPtrTy);
+
+  CharUnits size = CGF.getContext().getTypeSizeInChars(ivar->getType());
+  args.add(RValue::get(CGF.CGM.getSize(size)), Context.getSizeType());
+  args.add(RValue::get(CGF.Builder.getInt1(isAtomic)), Context.BoolTy);
+  args.add(RValue::get(CGF.Builder.getInt1(hasStrong)), Context.BoolTy);
+
+  llvm::Value *fn = CGF.CGM.getObjCRuntime().GetGetStructFunction();
+  CGF.EmitCall(CGF.getTypes().arrangeFunctionCall(Context.VoidTy, args,
+                                                  FunctionType::ExtInfo(),
+                                                  RequiredArgs::All),
+               fn, ReturnValueSlot(), args);
+}
+
+/// Determine whether the given architecture supports unaligned atomic
+/// accesses.  They don't have to be fast, just faster than a function
+/// call and a mutex.
+static bool hasUnalignedAtomics(llvm::Triple::ArchType arch) {
+  // FIXME: Allow unaligned atomic load/store on x86.  (It is not
+  // currently supported by the backend.)
+  return 0;
+}
+
+/// Return the maximum size that permits atomic accesses for the given
+/// architecture.
+static CharUnits getMaxAtomicAccessSize(CodeGenModule &CGM,
+                                        llvm::Triple::ArchType arch) {
+  // ARM has 8-byte atomic accesses, but it's not clear whether we
+  // want to rely on them here.
+
+  // In the default case, just assume that any size up to a pointer is
+  // fine given adequate alignment.
+  return CharUnits::fromQuantity(CGM.PointerSizeInBytes);
+}
+
+namespace {
+  class PropertyImplStrategy {
+  public:
+    enum StrategyKind {
+      /// The 'native' strategy is to use the architecture's provided
+      /// reads and writes.
+      Native,
+
+      /// Use objc_setProperty and objc_getProperty.
+      GetSetProperty,
+
+      /// Use objc_setProperty for the setter, but use expression
+      /// evaluation for the getter.
+      SetPropertyAndExpressionGet,
+
+      /// Use objc_copyStruct.
+      CopyStruct,
+
+      /// The 'expression' strategy is to emit normal assignment or
+      /// lvalue-to-rvalue expressions.
+      Expression
+    };
+
+    StrategyKind getKind() const { return StrategyKind(Kind); }
+
+    bool hasStrongMember() const { return HasStrong; }
+    bool isAtomic() const { return IsAtomic; }
+    bool isCopy() const { return IsCopy; }
+
+    CharUnits getIvarSize() const { return IvarSize; }
+    CharUnits getIvarAlignment() const { return IvarAlignment; }
+
+    PropertyImplStrategy(CodeGenModule &CGM,
+                         const ObjCPropertyImplDecl *propImpl);
+
+  private:
+    unsigned Kind : 8;
+    unsigned IsAtomic : 1;
+    unsigned IsCopy : 1;
+    unsigned HasStrong : 1;
+
+    CharUnits IvarSize;
+    CharUnits IvarAlignment;
+  };
+}
+
+/// Pick an implementation strategy for the the given property synthesis.
+PropertyImplStrategy::PropertyImplStrategy(CodeGenModule &CGM,
+                                     const ObjCPropertyImplDecl *propImpl) {
+  const ObjCPropertyDecl *prop = propImpl->getPropertyDecl();
+  ObjCPropertyDecl::SetterKind setterKind = prop->getSetterKind();
+
+  IsCopy = (setterKind == ObjCPropertyDecl::Copy);
+  IsAtomic = prop->isAtomic();
+  HasStrong = false; // doesn't matter here.
+
+  // Evaluate the ivar's size and alignment.
+  ObjCIvarDecl *ivar = propImpl->getPropertyIvarDecl();
+  QualType ivarType = ivar->getType();
+  llvm::tie(IvarSize, IvarAlignment)
+    = CGM.getContext().getTypeInfoInChars(ivarType);
+
+  // If we have a copy property, we always have to use getProperty/setProperty.
+  // TODO: we could actually use setProperty and an expression for non-atomics.
+  if (IsCopy) {
+    Kind = GetSetProperty;
+    return;
+  }
+
+  // Handle retain.
+  if (setterKind == ObjCPropertyDecl::Retain) {
+    // In GC-only, there's nothing special that needs to be done.
+    if (CGM.getLangOpts().getGC() == LangOptions::GCOnly) {
+      // fallthrough
+
+    // In ARC, if the property is non-atomic, use expression emission,
+    // which translates to objc_storeStrong.  This isn't required, but
+    // it's slightly nicer.
+    } else if (CGM.getLangOpts().ObjCAutoRefCount && !IsAtomic) {
+      Kind = Expression;
+      return;
+
+    // Otherwise, we need to at least use setProperty.  However, if
+    // the property isn't atomic, we can use normal expression
+    // emission for the getter.
+    } else if (!IsAtomic) {
+      Kind = SetPropertyAndExpressionGet;
+      return;
+
+    // Otherwise, we have to use both setProperty and getProperty.
+    } else {
+      Kind = GetSetProperty;
+      return;
+    }
+  }
+
+  // If we're not atomic, just use expression accesses.
+  if (!IsAtomic) {
+    Kind = Expression;
+    return;
+  }
+
+  // Properties on bitfield ivars need to be emitted using expression
+  // accesses even if they're nominally atomic.
+  if (ivar->isBitField()) {
+    Kind = Expression;
+    return;
+  }
+
+  // GC-qualified or ARC-qualified ivars need to be emitted as
+  // expressions.  This actually works out to being atomic anyway,
+  // except for ARC __strong, but that should trigger the above code.
+  if (ivarType.hasNonTrivialObjCLifetime() ||
+      (CGM.getLangOpts().getGC() &&
+       CGM.getContext().getObjCGCAttrKind(ivarType))) {
+    Kind = Expression;
+    return;
+  }
+
+  // Compute whether the ivar has strong members.
+  if (CGM.getLangOpts().getGC())
+    if (const RecordType *recordType = ivarType->getAs<RecordType>())
+      HasStrong = recordType->getDecl()->hasObjectMember();
+
+  // We can never access structs with object members with a native
+  // access, because we need to use write barriers.  This is what
+  // objc_copyStruct is for.
+  if (HasStrong) {
+    Kind = CopyStruct;
+    return;
+  }
+
+  // Otherwise, this is target-dependent and based on the size and
+  // alignment of the ivar.
+
+  // If the size of the ivar is not a power of two, give up.  We don't
+  // want to get into the business of doing compare-and-swaps.
+  if (!IvarSize.isPowerOfTwo()) {
+    Kind = CopyStruct;
+    return;
+  }
+
+  llvm::Triple::ArchType arch =
+    CGM.getContext().getTargetInfo().getTriple().getArch();
+
+  // Most architectures require memory to fit within a single cache
+  // line, so the alignment has to be at least the size of the access.
+  // Otherwise we have to grab a lock.
+  if (IvarAlignment < IvarSize && !hasUnalignedAtomics(arch)) {
+    Kind = CopyStruct;
+    return;
+  }
+
+  // If the ivar's size exceeds the architecture's maximum atomic
+  // access size, we have to use CopyStruct.
+  if (IvarSize > getMaxAtomicAccessSize(CGM, arch)) {
+    Kind = CopyStruct;
+    return;
+  }
+
+  // Otherwise, we can use native loads and stores.
+  Kind = Native;
+}
+
+/// GenerateObjCGetter - Generate an Objective-C property getter
+/// function. The given Decl must be an ObjCImplementationDecl. @synthesize
+/// is illegal within a category.
+void CodeGenFunction::GenerateObjCGetter(ObjCImplementationDecl *IMP,
+                                         const ObjCPropertyImplDecl *PID) {
+  llvm::Constant *AtomicHelperFn = 
+    GenerateObjCAtomicGetterCopyHelperFunction(PID);
+  const ObjCPropertyDecl *PD = PID->getPropertyDecl();
+  ObjCMethodDecl *OMD = PD->getGetterMethodDecl();
+  assert(OMD && "Invalid call to generate getter (empty method)");
+  StartObjCMethod(OMD, IMP->getClassInterface(), OMD->getLocStart());
+
+  generateObjCGetterBody(IMP, PID, AtomicHelperFn);
+
+  FinishFunction();
+}
+
+static bool hasTrivialGetExpr(const ObjCPropertyImplDecl *propImpl) {
+  const Expr *getter = propImpl->getGetterCXXConstructor();
+  if (!getter) return true;
+
+  // Sema only makes only of these when the ivar has a C++ class type,
+  // so the form is pretty constrained.
+
+  // If the property has a reference type, we might just be binding a
+  // reference, in which case the result will be a gl-value.  We should
+  // treat this as a non-trivial operation.
+  if (getter->isGLValue())
+    return false;
+
+  // If we selected a trivial copy-constructor, we're okay.
+  if (const CXXConstructExpr *construct = dyn_cast<CXXConstructExpr>(getter))
+    return (construct->getConstructor()->isTrivial());
+
+  // The constructor might require cleanups (in which case it's never
+  // trivial).
+  assert(isa<ExprWithCleanups>(getter));
+  return false;
+}
+
+/// emitCPPObjectAtomicGetterCall - Call the runtime function to 
+/// copy the ivar into the resturn slot.
+static void emitCPPObjectAtomicGetterCall(CodeGenFunction &CGF, 
+                                          llvm::Value *returnAddr,
+                                          ObjCIvarDecl *ivar,
+                                          llvm::Constant *AtomicHelperFn) {
+  // objc_copyCppObjectAtomic (&returnSlot, &CppObjectIvar,
+  //                           AtomicHelperFn);
+  CallArgList args;
+  
+  // The 1st argument is the return Slot.
+  args.add(RValue::get(returnAddr), CGF.getContext().VoidPtrTy);
+  
+  // The 2nd argument is the address of the ivar.
+  llvm::Value *ivarAddr = 
+  CGF.EmitLValueForIvar(CGF.TypeOfSelfObject(), 
+                        CGF.LoadObjCSelf(), ivar, 0).getAddress();
+  ivarAddr = CGF.Builder.CreateBitCast(ivarAddr, CGF.Int8PtrTy);
+  args.add(RValue::get(ivarAddr), CGF.getContext().VoidPtrTy);
+  
+  // Third argument is the helper function.
+  args.add(RValue::get(AtomicHelperFn), CGF.getContext().VoidPtrTy);
+  
+  llvm::Value *copyCppAtomicObjectFn = 
+  CGF.CGM.getObjCRuntime().GetCppAtomicObjectFunction();
+  CGF.EmitCall(CGF.getTypes().arrangeFunctionCall(CGF.getContext().VoidTy, args,
+                                                  FunctionType::ExtInfo(),
+                                                  RequiredArgs::All),
+               copyCppAtomicObjectFn, ReturnValueSlot(), args);
+}
+
+void
+CodeGenFunction::generateObjCGetterBody(const ObjCImplementationDecl *classImpl,
+                                        const ObjCPropertyImplDecl *propImpl,
+                                        llvm::Constant *AtomicHelperFn) {
+  // If there's a non-trivial 'get' expression, we just have to emit that.
+  if (!hasTrivialGetExpr(propImpl)) {
+    if (!AtomicHelperFn) {
+      ReturnStmt ret(SourceLocation(), propImpl->getGetterCXXConstructor(),
+                     /*nrvo*/ 0);
+      EmitReturnStmt(ret);
+    }
+    else {
+      ObjCIvarDecl *ivar = propImpl->getPropertyIvarDecl();
+      emitCPPObjectAtomicGetterCall(*this, ReturnValue, 
+                                    ivar, AtomicHelperFn);
+    }
+    return;
+  }
+
+  const ObjCPropertyDecl *prop = propImpl->getPropertyDecl();
+  QualType propType = prop->getType();
+  ObjCMethodDecl *getterMethod = prop->getGetterMethodDecl();
+
+  ObjCIvarDecl *ivar = propImpl->getPropertyIvarDecl();  
+
+  // Pick an implementation strategy.
+  PropertyImplStrategy strategy(CGM, propImpl);
+  switch (strategy.getKind()) {
+  case PropertyImplStrategy::Native: {
+    LValue LV = EmitLValueForIvar(TypeOfSelfObject(), LoadObjCSelf(), ivar, 0);
+
+    // Currently, all atomic accesses have to be through integer
+    // types, so there's no point in trying to pick a prettier type.
+    llvm::Type *bitcastType =
+      llvm::Type::getIntNTy(getLLVMContext(),
+                            getContext().toBits(strategy.getIvarSize()));
+    bitcastType = bitcastType->getPointerTo(); // addrspace 0 okay
+
+    // Perform an atomic load.  This does not impose ordering constraints.
+    llvm::Value *ivarAddr = LV.getAddress();
+    ivarAddr = Builder.CreateBitCast(ivarAddr, bitcastType);
+    llvm::LoadInst *load = Builder.CreateLoad(ivarAddr, "load");
+    load->setAlignment(strategy.getIvarAlignment().getQuantity());
+    load->setAtomic(llvm::Unordered);
+
+    // Store that value into the return address.  Doing this with a
+    // bitcast is likely to produce some pretty ugly IR, but it's not
+    // the *most* terrible thing in the world.
+    Builder.CreateStore(load, Builder.CreateBitCast(ReturnValue, bitcastType));
+
+    // Make sure we don't do an autorelease.
+    AutoreleaseResult = false;
+    return;
+  }
+
+  case PropertyImplStrategy::GetSetProperty: {
+    llvm::Value *getPropertyFn =
+      CGM.getObjCRuntime().GetPropertyGetFunction();
+    if (!getPropertyFn) {
+      CGM.ErrorUnsupported(propImpl, "Obj-C getter requiring atomic copy");
+      return;
+    }
+
+    // Return (ivar-type) objc_getProperty((id) self, _cmd, offset, true).
+    // FIXME: Can't this be simpler? This might even be worse than the
+    // corresponding gcc code.
+    llvm::Value *cmd =
+      Builder.CreateLoad(LocalDeclMap[getterMethod->getCmdDecl()], "cmd");
+    llvm::Value *self = Builder.CreateBitCast(LoadObjCSelf(), VoidPtrTy);
+    llvm::Value *ivarOffset =
+      EmitIvarOffset(classImpl->getClassInterface(), ivar);
+
+    CallArgList args;
+    args.add(RValue::get(self), getContext().getObjCIdType());
+    args.add(RValue::get(cmd), getContext().getObjCSelType());
+    args.add(RValue::get(ivarOffset), getContext().getPointerDiffType());
+    args.add(RValue::get(Builder.getInt1(strategy.isAtomic())),
+             getContext().BoolTy);
+
+    // FIXME: We shouldn't need to get the function info here, the
+    // runtime already should have computed it to build the function.
+    RValue RV = EmitCall(getTypes().arrangeFunctionCall(propType, args,
+                                                        FunctionType::ExtInfo(),
+                                                        RequiredArgs::All),
+                         getPropertyFn, ReturnValueSlot(), args);
+
+    // We need to fix the type here. Ivars with copy & retain are
+    // always objects so we don't need to worry about complex or
+    // aggregates.
+    RV = RValue::get(Builder.CreateBitCast(RV.getScalarVal(),
+                                           getTypes().ConvertType(propType)));
+
+    EmitReturnOfRValue(RV, propType);
+
+    // objc_getProperty does an autorelease, so we should suppress ours.
+    AutoreleaseResult = false;
+
+    return;
+  }
+
+  case PropertyImplStrategy::CopyStruct:
+    emitStructGetterCall(*this, ivar, strategy.isAtomic(),
+                         strategy.hasStrongMember());
+    return;
+
+  case PropertyImplStrategy::Expression:
+  case PropertyImplStrategy::SetPropertyAndExpressionGet: {
+    LValue LV = EmitLValueForIvar(TypeOfSelfObject(), LoadObjCSelf(), ivar, 0);
+
+    QualType ivarType = ivar->getType();
+    if (ivarType->isAnyComplexType()) {
+      ComplexPairTy pair = LoadComplexFromAddr(LV.getAddress(),
+                                               LV.isVolatileQualified());
+      StoreComplexToAddr(pair, ReturnValue, LV.isVolatileQualified());
+    } else if (hasAggregateLLVMType(ivarType)) {
+      // The return value slot is guaranteed to not be aliased, but
+      // that's not necessarily the same as "on the stack", so
+      // we still potentially need objc_memmove_collectable.
+      EmitAggregateCopy(ReturnValue, LV.getAddress(), ivarType);
+    } else {
+      llvm::Value *value;
+      if (propType->isReferenceType()) {
+        value = LV.getAddress();
+      } else {
+        // We want to load and autoreleaseReturnValue ARC __weak ivars.
+        if (LV.getQuals().getObjCLifetime() == Qualifiers::OCL_Weak) {
+          value = emitARCRetainLoadOfScalar(*this, LV, ivarType);
+
+        // Otherwise we want to do a simple load, suppressing the
+        // final autorelease.
+        } else {
+          value = EmitLoadOfLValue(LV).getScalarVal();
+          AutoreleaseResult = false;
+        }
+
+        value = Builder.CreateBitCast(value, ConvertType(propType));
+      }
+      
+      EmitReturnOfRValue(RValue::get(value), propType);
+    }
+    return;
+  }
+
+  }
+  llvm_unreachable("bad @property implementation strategy!");
+}
+
+/// emitStructSetterCall - Call the runtime function to store the value
+/// from the first formal parameter into the given ivar.
+static void emitStructSetterCall(CodeGenFunction &CGF, ObjCMethodDecl *OMD,
+                                 ObjCIvarDecl *ivar) {
+  // objc_copyStruct (&structIvar, &Arg, 
+  //                  sizeof (struct something), true, false);
+  CallArgList args;
+
+  // The first argument is the address of the ivar.
+  llvm::Value *ivarAddr = CGF.EmitLValueForIvar(CGF.TypeOfSelfObject(),
+                                                CGF.LoadObjCSelf(), ivar, 0)
+    .getAddress();
+  ivarAddr = CGF.Builder.CreateBitCast(ivarAddr, CGF.Int8PtrTy);
+  args.add(RValue::get(ivarAddr), CGF.getContext().VoidPtrTy);
+
+  // The second argument is the address of the parameter variable.
+  ParmVarDecl *argVar = *OMD->param_begin();
+  DeclRefExpr argRef(argVar, false, argVar->getType().getNonReferenceType(), 
+                     VK_LValue, SourceLocation());
+  llvm::Value *argAddr = CGF.EmitLValue(&argRef).getAddress();
+  argAddr = CGF.Builder.CreateBitCast(argAddr, CGF.Int8PtrTy);
+  args.add(RValue::get(argAddr), CGF.getContext().VoidPtrTy);
+
+  // The third argument is the sizeof the type.
+  llvm::Value *size =
+    CGF.CGM.getSize(CGF.getContext().getTypeSizeInChars(ivar->getType()));
+  args.add(RValue::get(size), CGF.getContext().getSizeType());
+
+  // The fourth argument is the 'isAtomic' flag.
+  args.add(RValue::get(CGF.Builder.getTrue()), CGF.getContext().BoolTy);
+
+  // The fifth argument is the 'hasStrong' flag.
+  // FIXME: should this really always be false?
+  args.add(RValue::get(CGF.Builder.getFalse()), CGF.getContext().BoolTy);
+
+  llvm::Value *copyStructFn = CGF.CGM.getObjCRuntime().GetSetStructFunction();
+  CGF.EmitCall(CGF.getTypes().arrangeFunctionCall(CGF.getContext().VoidTy, args,
+                                                  FunctionType::ExtInfo(),
+                                                  RequiredArgs::All),
+               copyStructFn, ReturnValueSlot(), args);
+}
+
+/// emitCPPObjectAtomicSetterCall - Call the runtime function to store 
+/// the value from the first formal parameter into the given ivar, using 
+/// the Cpp API for atomic Cpp objects with non-trivial copy assignment.
+static void emitCPPObjectAtomicSetterCall(CodeGenFunction &CGF, 
+                                          ObjCMethodDecl *OMD,
+                                          ObjCIvarDecl *ivar,
+                                          llvm::Constant *AtomicHelperFn) {
+  // objc_copyCppObjectAtomic (&CppObjectIvar, &Arg, 
+  //                           AtomicHelperFn);
+  CallArgList args;
+  
+  // The first argument is the address of the ivar.
+  llvm::Value *ivarAddr = 
+    CGF.EmitLValueForIvar(CGF.TypeOfSelfObject(), 
+                          CGF.LoadObjCSelf(), ivar, 0).getAddress();
+  ivarAddr = CGF.Builder.CreateBitCast(ivarAddr, CGF.Int8PtrTy);
+  args.add(RValue::get(ivarAddr), CGF.getContext().VoidPtrTy);
+  
+  // The second argument is the address of the parameter variable.
+  ParmVarDecl *argVar = *OMD->param_begin();
+  DeclRefExpr argRef(argVar, false, argVar->getType().getNonReferenceType(), 
+                     VK_LValue, SourceLocation());
+  llvm::Value *argAddr = CGF.EmitLValue(&argRef).getAddress();
+  argAddr = CGF.Builder.CreateBitCast(argAddr, CGF.Int8PtrTy);
+  args.add(RValue::get(argAddr), CGF.getContext().VoidPtrTy);
+  
+  // Third argument is the helper function.
+  args.add(RValue::get(AtomicHelperFn), CGF.getContext().VoidPtrTy);
+  
+  llvm::Value *copyCppAtomicObjectFn = 
+    CGF.CGM.getObjCRuntime().GetCppAtomicObjectFunction();
+  CGF.EmitCall(CGF.getTypes().arrangeFunctionCall(CGF.getContext().VoidTy, args,
+                                                  FunctionType::ExtInfo(),
+                                                  RequiredArgs::All),
+               copyCppAtomicObjectFn, ReturnValueSlot(), args);
+  
+
+}
+
+
+static bool hasTrivialSetExpr(const ObjCPropertyImplDecl *PID) {
+  Expr *setter = PID->getSetterCXXAssignment();
+  if (!setter) return true;
+
+  // Sema only makes only of these when the ivar has a C++ class type,
+  // so the form is pretty constrained.
+
+  // An operator call is trivial if the function it calls is trivial.
+  // This also implies that there's nothing non-trivial going on with
+  // the arguments, because operator= can only be trivial if it's a
+  // synthesized assignment operator and therefore both parameters are
+  // references.
+  if (CallExpr *call = dyn_cast<CallExpr>(setter)) {
+    if (const FunctionDecl *callee
+          = dyn_cast_or_null<FunctionDecl>(call->getCalleeDecl()))
+      if (callee->isTrivial())
+        return true;
+    return false;
+  }
+
+  assert(isa<ExprWithCleanups>(setter));
+  return false;
+}
+
+static bool UseOptimizedSetter(CodeGenModule &CGM) {
+  if (CGM.getLangOpts().getGC() != LangOptions::NonGC)
+    return false;
+  const TargetInfo &Target = CGM.getContext().getTargetInfo();
+
+  if (Target.getPlatformName() != "macosx")
+    return false;
+
+  return Target.getPlatformMinVersion() >= VersionTuple(10, 8);
+}
+
+void
+CodeGenFunction::generateObjCSetterBody(const ObjCImplementationDecl *classImpl,
+                                        const ObjCPropertyImplDecl *propImpl,
+                                        llvm::Constant *AtomicHelperFn) {
+  const ObjCPropertyDecl *prop = propImpl->getPropertyDecl();
+  ObjCIvarDecl *ivar = propImpl->getPropertyIvarDecl();
+  ObjCMethodDecl *setterMethod = prop->getSetterMethodDecl();
+  
+  // Just use the setter expression if Sema gave us one and it's
+  // non-trivial.
+  if (!hasTrivialSetExpr(propImpl)) {
+    if (!AtomicHelperFn)
+      // If non-atomic, assignment is called directly.
+      EmitStmt(propImpl->getSetterCXXAssignment());
+    else
+      // If atomic, assignment is called via a locking api.
+      emitCPPObjectAtomicSetterCall(*this, setterMethod, ivar,
+                                    AtomicHelperFn);
+    return;
+  }
+
+  PropertyImplStrategy strategy(CGM, propImpl);
+  switch (strategy.getKind()) {
+  case PropertyImplStrategy::Native: {
+    llvm::Value *argAddr = LocalDeclMap[*setterMethod->param_begin()];
+
+    LValue ivarLValue =
+      EmitLValueForIvar(TypeOfSelfObject(), LoadObjCSelf(), ivar, /*quals*/ 0);
+    llvm::Value *ivarAddr = ivarLValue.getAddress();
+
+    // Currently, all atomic accesses have to be through integer
+    // types, so there's no point in trying to pick a prettier type.
+    llvm::Type *bitcastType =
+      llvm::Type::getIntNTy(getLLVMContext(),
+                            getContext().toBits(strategy.getIvarSize()));
+    bitcastType = bitcastType->getPointerTo(); // addrspace 0 okay
+
+    // Cast both arguments to the chosen operation type.
+    argAddr = Builder.CreateBitCast(argAddr, bitcastType);
+    ivarAddr = Builder.CreateBitCast(ivarAddr, bitcastType);
+
+    // This bitcast load is likely to cause some nasty IR.
+    llvm::Value *load = Builder.CreateLoad(argAddr);
+
+    // Perform an atomic store.  There are no memory ordering requirements.
+    llvm::StoreInst *store = Builder.CreateStore(load, ivarAddr);
+    store->setAlignment(strategy.getIvarAlignment().getQuantity());
+    store->setAtomic(llvm::Unordered);
+    return;
+  }
+
+  case PropertyImplStrategy::GetSetProperty:
+  case PropertyImplStrategy::SetPropertyAndExpressionGet: {
+  
+    llvm::Value *setOptimizedPropertyFn = 0;
+    llvm::Value *setPropertyFn = 0;
+    if (UseOptimizedSetter(CGM)) {
+      // 10.8 code and GC is off
+      setOptimizedPropertyFn = 
+        CGM.getObjCRuntime()
+           .GetOptimizedPropertySetFunction(strategy.isAtomic(),
+                                            strategy.isCopy());
+      if (!setOptimizedPropertyFn) {
+        CGM.ErrorUnsupported(propImpl, "Obj-C optimized setter - NYI");
+        return;
+      }
+    }
+    else {
+      setPropertyFn = CGM.getObjCRuntime().GetPropertySetFunction();
+      if (!setPropertyFn) {
+        CGM.ErrorUnsupported(propImpl, "Obj-C setter requiring atomic copy");
+        return;
+      }
+    }
+   
+    // Emit objc_setProperty((id) self, _cmd, offset, arg,
+    //                       <is-atomic>, <is-copy>).
+    llvm::Value *cmd =
+      Builder.CreateLoad(LocalDeclMap[setterMethod->getCmdDecl()]);
+    llvm::Value *self =
+      Builder.CreateBitCast(LoadObjCSelf(), VoidPtrTy);
+    llvm::Value *ivarOffset =
+      EmitIvarOffset(classImpl->getClassInterface(), ivar);
+    llvm::Value *arg = LocalDeclMap[*setterMethod->param_begin()];
+    arg = Builder.CreateBitCast(Builder.CreateLoad(arg, "arg"), VoidPtrTy);
+
+    CallArgList args;
+    args.add(RValue::get(self), getContext().getObjCIdType());
+    args.add(RValue::get(cmd), getContext().getObjCSelType());
+    if (setOptimizedPropertyFn) {
+      args.add(RValue::get(arg), getContext().getObjCIdType());
+      args.add(RValue::get(ivarOffset), getContext().getPointerDiffType());
+      EmitCall(getTypes().arrangeFunctionCall(getContext().VoidTy, args,
+                                              FunctionType::ExtInfo(),
+                                              RequiredArgs::All),
+               setOptimizedPropertyFn, ReturnValueSlot(), args);
+    } else {
+      args.add(RValue::get(ivarOffset), getContext().getPointerDiffType());
+      args.add(RValue::get(arg), getContext().getObjCIdType());
+      args.add(RValue::get(Builder.getInt1(strategy.isAtomic())),
+               getContext().BoolTy);
+      args.add(RValue::get(Builder.getInt1(strategy.isCopy())),
+               getContext().BoolTy);
+      // FIXME: We shouldn't need to get the function info here, the runtime
+      // already should have computed it to build the function.
+      EmitCall(getTypes().arrangeFunctionCall(getContext().VoidTy, args,
+                                              FunctionType::ExtInfo(),
+                                              RequiredArgs::All),
+               setPropertyFn, ReturnValueSlot(), args);
+    }
+    
+    return;
+  }
+
+  case PropertyImplStrategy::CopyStruct:
+    emitStructSetterCall(*this, setterMethod, ivar);
+    return;
+
+  case PropertyImplStrategy::Expression:
+    break;
+  }
+
+  // Otherwise, fake up some ASTs and emit a normal assignment.
+  ValueDecl *selfDecl = setterMethod->getSelfDecl();
+  DeclRefExpr self(selfDecl, false, selfDecl->getType(),
+                   VK_LValue, SourceLocation());
+  ImplicitCastExpr selfLoad(ImplicitCastExpr::OnStack,
+                            selfDecl->getType(), CK_LValueToRValue, &self,
+                            VK_RValue);
+  ObjCIvarRefExpr ivarRef(ivar, ivar->getType().getNonReferenceType(),
+                          SourceLocation(), &selfLoad, true, true);
+
+  ParmVarDecl *argDecl = *setterMethod->param_begin();
+  QualType argType = argDecl->getType().getNonReferenceType();
+  DeclRefExpr arg(argDecl, false, argType, VK_LValue, SourceLocation());
+  ImplicitCastExpr argLoad(ImplicitCastExpr::OnStack,
+                           argType.getUnqualifiedType(), CK_LValueToRValue,
+                           &arg, VK_RValue);
+    
+  // The property type can differ from the ivar type in some situations with
+  // Objective-C pointer types, we can always bit cast the RHS in these cases.
+  // The following absurdity is just to ensure well-formed IR.
+  CastKind argCK = CK_NoOp;
+  if (ivarRef.getType()->isObjCObjectPointerType()) {
+    if (argLoad.getType()->isObjCObjectPointerType())
+      argCK = CK_BitCast;
+    else if (argLoad.getType()->isBlockPointerType())
+      argCK = CK_BlockPointerToObjCPointerCast;
+    else
+      argCK = CK_CPointerToObjCPointerCast;
+  } else if (ivarRef.getType()->isBlockPointerType()) {
+     if (argLoad.getType()->isBlockPointerType())
+      argCK = CK_BitCast;
+    else
+      argCK = CK_AnyPointerToBlockPointerCast;
+  } else if (ivarRef.getType()->isPointerType()) {
+    argCK = CK_BitCast;
+  }
+  ImplicitCastExpr argCast(ImplicitCastExpr::OnStack,
+                           ivarRef.getType(), argCK, &argLoad,
+                           VK_RValue);
+  Expr *finalArg = &argLoad;
+  if (!getContext().hasSameUnqualifiedType(ivarRef.getType(),
+                                           argLoad.getType()))
+    finalArg = &argCast;
+
+
+  BinaryOperator assign(&ivarRef, finalArg, BO_Assign,
+                        ivarRef.getType(), VK_RValue, OK_Ordinary,
+                        SourceLocation());
+  EmitStmt(&assign);
+}
+
+/// GenerateObjCSetter - Generate an Objective-C property setter
+/// function. The given Decl must be an ObjCImplementationDecl. @synthesize
+/// is illegal within a category.
+void CodeGenFunction::GenerateObjCSetter(ObjCImplementationDecl *IMP,
+                                         const ObjCPropertyImplDecl *PID) {
+  llvm::Constant *AtomicHelperFn = 
+    GenerateObjCAtomicSetterCopyHelperFunction(PID);
+  const ObjCPropertyDecl *PD = PID->getPropertyDecl();
+  ObjCMethodDecl *OMD = PD->getSetterMethodDecl();
+  assert(OMD && "Invalid call to generate setter (empty method)");
+  StartObjCMethod(OMD, IMP->getClassInterface(), OMD->getLocStart());
+
+  generateObjCSetterBody(IMP, PID, AtomicHelperFn);
+
+  FinishFunction();
+}
+
+namespace {
+  struct DestroyIvar : EHScopeStack::Cleanup {
+  private:
+    llvm::Value *addr;
+    const ObjCIvarDecl *ivar;
+    CodeGenFunction::Destroyer *destroyer;
+    bool useEHCleanupForArray;
+  public:
+    DestroyIvar(llvm::Value *addr, const ObjCIvarDecl *ivar,
+                CodeGenFunction::Destroyer *destroyer,
+                bool useEHCleanupForArray)
+      : addr(addr), ivar(ivar), destroyer(destroyer),
+        useEHCleanupForArray(useEHCleanupForArray) {}
+
+    void Emit(CodeGenFunction &CGF, Flags flags) {
+      LValue lvalue
+        = CGF.EmitLValueForIvar(CGF.TypeOfSelfObject(), addr, ivar, /*CVR*/ 0);
+      CGF.emitDestroy(lvalue.getAddress(), ivar->getType(), destroyer,
+                      flags.isForNormalCleanup() && useEHCleanupForArray);
+    }
+  };
+}
+
+/// Like CodeGenFunction::destroyARCStrong, but do it with a call.
+static void destroyARCStrongWithStore(CodeGenFunction &CGF,
+                                      llvm::Value *addr,
+                                      QualType type) {
+  llvm::Value *null = getNullForVariable(addr);
+  CGF.EmitARCStoreStrongCall(addr, null, /*ignored*/ true);
+}
+
+static void emitCXXDestructMethod(CodeGenFunction &CGF,
+                                  ObjCImplementationDecl *impl) {
+  CodeGenFunction::RunCleanupsScope scope(CGF);
+
+  llvm::Value *self = CGF.LoadObjCSelf();
+
+  const ObjCInterfaceDecl *iface = impl->getClassInterface();
+  for (const ObjCIvarDecl *ivar = iface->all_declared_ivar_begin();
+       ivar; ivar = ivar->getNextIvar()) {
+    QualType type = ivar->getType();
+
+    // Check whether the ivar is a destructible type.
+    QualType::DestructionKind dtorKind = type.isDestructedType();
+    if (!dtorKind) continue;
+
+    CodeGenFunction::Destroyer *destroyer = 0;
+
+    // Use a call to objc_storeStrong to destroy strong ivars, for the
+    // general benefit of the tools.
+    if (dtorKind == QualType::DK_objc_strong_lifetime) {
+      destroyer = destroyARCStrongWithStore;
+
+    // Otherwise use the default for the destruction kind.
+    } else {
+      destroyer = CGF.getDestroyer(dtorKind);
+    }
+
+    CleanupKind cleanupKind = CGF.getCleanupKind(dtorKind);
+
+    CGF.EHStack.pushCleanup<DestroyIvar>(cleanupKind, self, ivar, destroyer,
+                                         cleanupKind & EHCleanup);
+  }
+
+  assert(scope.requiresCleanups() && "nothing to do in .cxx_destruct?");
+}
+
+void CodeGenFunction::GenerateObjCCtorDtorMethod(ObjCImplementationDecl *IMP,
+                                                 ObjCMethodDecl *MD,
+                                                 bool ctor) {
+  MD->createImplicitParams(CGM.getContext(), IMP->getClassInterface());
+  StartObjCMethod(MD, IMP->getClassInterface(), MD->getLocStart());
+
+  // Emit .cxx_construct.
+  if (ctor) {
+    // Suppress the final autorelease in ARC.
+    AutoreleaseResult = false;
+
+    SmallVector<CXXCtorInitializer *, 8> IvarInitializers;
+    for (ObjCImplementationDecl::init_const_iterator B = IMP->init_begin(),
+           E = IMP->init_end(); B != E; ++B) {
+      CXXCtorInitializer *IvarInit = (*B);
+      FieldDecl *Field = IvarInit->getAnyMember();
+      ObjCIvarDecl  *Ivar = cast<ObjCIvarDecl>(Field);
+      LValue LV = EmitLValueForIvar(TypeOfSelfObject(), 
+                                    LoadObjCSelf(), Ivar, 0);
+      EmitAggExpr(IvarInit->getInit(),
+                  AggValueSlot::forLValue(LV, AggValueSlot::IsDestructed,
+                                          AggValueSlot::DoesNotNeedGCBarriers,
+                                          AggValueSlot::IsNotAliased));
+    }
+    // constructor returns 'self'.
+    CodeGenTypes &Types = CGM.getTypes();
+    QualType IdTy(CGM.getContext().getObjCIdType());
+    llvm::Value *SelfAsId =
+      Builder.CreateBitCast(LoadObjCSelf(), Types.ConvertType(IdTy));
+    EmitReturnOfRValue(RValue::get(SelfAsId), IdTy);
+
+  // Emit .cxx_destruct.
+  } else {
+    emitCXXDestructMethod(*this, IMP);
+  }
+  FinishFunction();
+}
+
+bool CodeGenFunction::IndirectObjCSetterArg(const CGFunctionInfo &FI) {
+  CGFunctionInfo::const_arg_iterator it = FI.arg_begin();
+  it++; it++;
+  const ABIArgInfo &AI = it->info;
+  // FIXME. Is this sufficient check?
+  return (AI.getKind() == ABIArgInfo::Indirect);
+}
+
+bool CodeGenFunction::IvarTypeWithAggrGCObjects(QualType Ty) {
+  if (CGM.getLangOpts().getGC() == LangOptions::NonGC)
+    return false;
+  if (const RecordType *FDTTy = Ty.getTypePtr()->getAs<RecordType>())
+    return FDTTy->getDecl()->hasObjectMember();
+  return false;
+}
+
+llvm::Value *CodeGenFunction::LoadObjCSelf() {
+  const ObjCMethodDecl *OMD = cast<ObjCMethodDecl>(CurFuncDecl);
+  return Builder.CreateLoad(LocalDeclMap[OMD->getSelfDecl()], "self");
+}
+
+QualType CodeGenFunction::TypeOfSelfObject() {
+  const ObjCMethodDecl *OMD = cast<ObjCMethodDecl>(CurFuncDecl);
+  ImplicitParamDecl *selfDecl = OMD->getSelfDecl();
+  const ObjCObjectPointerType *PTy = cast<ObjCObjectPointerType>(
+    getContext().getCanonicalType(selfDecl->getType()));
+  return PTy->getPointeeType();
+}
+
+void CodeGenFunction::EmitObjCForCollectionStmt(const ObjCForCollectionStmt &S){
+  llvm::Constant *EnumerationMutationFn =
+    CGM.getObjCRuntime().EnumerationMutationFunction();
+
+  if (!EnumerationMutationFn) {
+    CGM.ErrorUnsupported(&S, "Obj-C fast enumeration for this runtime");
+    return;
+  }
+
+  CGDebugInfo *DI = getDebugInfo();
+  if (DI)
+    DI->EmitLexicalBlockStart(Builder, S.getSourceRange().getBegin());
+
+  // The local variable comes into scope immediately.
+  AutoVarEmission variable = AutoVarEmission::invalid();
+  if (const DeclStmt *SD = dyn_cast<DeclStmt>(S.getElement()))
+    variable = EmitAutoVarAlloca(*cast<VarDecl>(SD->getSingleDecl()));
+
+  JumpDest LoopEnd = getJumpDestInCurrentScope("forcoll.end");
+
+  // Fast enumeration state.
+  QualType StateTy = CGM.getObjCFastEnumerationStateType();
+  llvm::Value *StatePtr = CreateMemTemp(StateTy, "state.ptr");
+  EmitNullInitialization(StatePtr, StateTy);
+
+  // Number of elements in the items array.
+  static const unsigned NumItems = 16;
+
+  // Fetch the countByEnumeratingWithState:objects:count: selector.
+  IdentifierInfo *II[] = {
+    &CGM.getContext().Idents.get("countByEnumeratingWithState"),
+    &CGM.getContext().Idents.get("objects"),
+    &CGM.getContext().Idents.get("count")
+  };
+  Selector FastEnumSel =
+    CGM.getContext().Selectors.getSelector(llvm::array_lengthof(II), &II[0]);
+
+  QualType ItemsTy =
+    getContext().getConstantArrayType(getContext().getObjCIdType(),
+                                      llvm::APInt(32, NumItems),
+                                      ArrayType::Normal, 0);
+  llvm::Value *ItemsPtr = CreateMemTemp(ItemsTy, "items.ptr");
+
+  // Emit the collection pointer.  In ARC, we do a retain.
+  llvm::Value *Collection;
+  if (getLangOpts().ObjCAutoRefCount) {
+    Collection = EmitARCRetainScalarExpr(S.getCollection());
+
+    // Enter a cleanup to do the release.
+    EmitObjCConsumeObject(S.getCollection()->getType(), Collection);
+  } else {
+    Collection = EmitScalarExpr(S.getCollection());
+  }
+
+  // The 'continue' label needs to appear within the cleanup for the
+  // collection object.
+  JumpDest AfterBody = getJumpDestInCurrentScope("forcoll.next");
+
+  // Send it our message:
+  CallArgList Args;
+
+  // The first argument is a temporary of the enumeration-state type.
+  Args.add(RValue::get(StatePtr), getContext().getPointerType(StateTy));
+
+  // The second argument is a temporary array with space for NumItems
+  // pointers.  We'll actually be loading elements from the array
+  // pointer written into the control state; this buffer is so that
+  // collections that *aren't* backed by arrays can still queue up
+  // batches of elements.
+  Args.add(RValue::get(ItemsPtr), getContext().getPointerType(ItemsTy));
+
+  // The third argument is the capacity of that temporary array.
+  llvm::Type *UnsignedLongLTy = ConvertType(getContext().UnsignedLongTy);
+  llvm::Constant *Count = llvm::ConstantInt::get(UnsignedLongLTy, NumItems);
+  Args.add(RValue::get(Count), getContext().UnsignedLongTy);
+
+  // Start the enumeration.
+  RValue CountRV =
+    CGM.getObjCRuntime().GenerateMessageSend(*this, ReturnValueSlot(),
+                                             getContext().UnsignedLongTy,
+                                             FastEnumSel,
+                                             Collection, Args);
+
+  // The initial number of objects that were returned in the buffer.
+  llvm::Value *initialBufferLimit = CountRV.getScalarVal();
+
+  llvm::BasicBlock *EmptyBB = createBasicBlock("forcoll.empty");
+  llvm::BasicBlock *LoopInitBB = createBasicBlock("forcoll.loopinit");
+
+  llvm::Value *zero = llvm::Constant::getNullValue(UnsignedLongLTy);
+
+  // If the limit pointer was zero to begin with, the collection is
+  // empty; skip all this.
+  Builder.CreateCondBr(Builder.CreateICmpEQ(initialBufferLimit, zero, "iszero"),
+                       EmptyBB, LoopInitBB);
+
+  // Otherwise, initialize the loop.
+  EmitBlock(LoopInitBB);
+
+  // Save the initial mutations value.  This is the value at an
+  // address that was written into the state object by
+  // countByEnumeratingWithState:objects:count:.
+  llvm::Value *StateMutationsPtrPtr =
+    Builder.CreateStructGEP(StatePtr, 2, "mutationsptr.ptr");
+  llvm::Value *StateMutationsPtr = Builder.CreateLoad(StateMutationsPtrPtr,
+                                                      "mutationsptr");
+
+  llvm::Value *initialMutations =
+    Builder.CreateLoad(StateMutationsPtr, "forcoll.initial-mutations");
+
+  // Start looping.  This is the point we return to whenever we have a
+  // fresh, non-empty batch of objects.
+  llvm::BasicBlock *LoopBodyBB = createBasicBlock("forcoll.loopbody");
+  EmitBlock(LoopBodyBB);
+
+  // The current index into the buffer.
+  llvm::PHINode *index = Builder.CreatePHI(UnsignedLongLTy, 3, "forcoll.index");
+  index->addIncoming(zero, LoopInitBB);
+
+  // The current buffer size.
+  llvm::PHINode *count = Builder.CreatePHI(UnsignedLongLTy, 3, "forcoll.count");
+  count->addIncoming(initialBufferLimit, LoopInitBB);
+
+  // Check whether the mutations value has changed from where it was
+  // at start.  StateMutationsPtr should actually be invariant between
+  // refreshes.
+  StateMutationsPtr = Builder.CreateLoad(StateMutationsPtrPtr, "mutationsptr");
+  llvm::Value *currentMutations
+    = Builder.CreateLoad(StateMutationsPtr, "statemutations");
+
+  llvm::BasicBlock *WasMutatedBB = createBasicBlock("forcoll.mutated");
+  llvm::BasicBlock *WasNotMutatedBB = createBasicBlock("forcoll.notmutated");
+
+  Builder.CreateCondBr(Builder.CreateICmpEQ(currentMutations, initialMutations),
+                       WasNotMutatedBB, WasMutatedBB);
+
+  // If so, call the enumeration-mutation function.
+  EmitBlock(WasMutatedBB);
+  llvm::Value *V =
+    Builder.CreateBitCast(Collection,
+                          ConvertType(getContext().getObjCIdType()));
+  CallArgList Args2;
+  Args2.add(RValue::get(V), getContext().getObjCIdType());
+  // FIXME: We shouldn't need to get the function info here, the runtime already
+  // should have computed it to build the function.
+  EmitCall(CGM.getTypes().arrangeFunctionCall(getContext().VoidTy, Args2,
+                                              FunctionType::ExtInfo(),
+                                              RequiredArgs::All),
+           EnumerationMutationFn, ReturnValueSlot(), Args2);
+
+  // Otherwise, or if the mutation function returns, just continue.
+  EmitBlock(WasNotMutatedBB);
+
+  // Initialize the element variable.
+  RunCleanupsScope elementVariableScope(*this);
+  bool elementIsVariable;
+  LValue elementLValue;
+  QualType elementType;
+  if (const DeclStmt *SD = dyn_cast<DeclStmt>(S.getElement())) {
+    // Initialize the variable, in case it's a __block variable or something.
+    EmitAutoVarInit(variable);
+
+    const VarDecl* D = cast<VarDecl>(SD->getSingleDecl());
+    DeclRefExpr tempDRE(const_cast<VarDecl*>(D), false, D->getType(),
+                        VK_LValue, SourceLocation());
+    elementLValue = EmitLValue(&tempDRE);
+    elementType = D->getType();
+    elementIsVariable = true;
+
+    if (D->isARCPseudoStrong())
+      elementLValue.getQuals().setObjCLifetime(Qualifiers::OCL_ExplicitNone);
+  } else {
+    elementLValue = LValue(); // suppress warning
+    elementType = cast<Expr>(S.getElement())->getType();
+    elementIsVariable = false;
+  }
+  llvm::Type *convertedElementType = ConvertType(elementType);
+
+  // Fetch the buffer out of the enumeration state.
+  // TODO: this pointer should actually be invariant between
+  // refreshes, which would help us do certain loop optimizations.
+  llvm::Value *StateItemsPtr =
+    Builder.CreateStructGEP(StatePtr, 1, "stateitems.ptr");
+  llvm::Value *EnumStateItems =
+    Builder.CreateLoad(StateItemsPtr, "stateitems");
+
+  // Fetch the value at the current index from the buffer.
+  llvm::Value *CurrentItemPtr =
+    Builder.CreateGEP(EnumStateItems, index, "currentitem.ptr");
+  llvm::Value *CurrentItem = Builder.CreateLoad(CurrentItemPtr);
+
+  // Cast that value to the right type.
+  CurrentItem = Builder.CreateBitCast(CurrentItem, convertedElementType,
+                                      "currentitem");
+
+  // Make sure we have an l-value.  Yes, this gets evaluated every
+  // time through the loop.
+  if (!elementIsVariable) {
+    elementLValue = EmitLValue(cast<Expr>(S.getElement()));
+    EmitStoreThroughLValue(RValue::get(CurrentItem), elementLValue);
+  } else {
+    EmitScalarInit(CurrentItem, elementLValue);
+  }
+
+  // If we do have an element variable, this assignment is the end of
+  // its initialization.
+  if (elementIsVariable)
+    EmitAutoVarCleanups(variable);
+
+  // Perform the loop body, setting up break and continue labels.
+  BreakContinueStack.push_back(BreakContinue(LoopEnd, AfterBody));
+  {
+    RunCleanupsScope Scope(*this);
+    EmitStmt(S.getBody());
+  }
+  BreakContinueStack.pop_back();
+
+  // Destroy the element variable now.
+  elementVariableScope.ForceCleanup();
+
+  // Check whether there are more elements.
+  EmitBlock(AfterBody.getBlock());
+
+  llvm::BasicBlock *FetchMoreBB = createBasicBlock("forcoll.refetch");
+
+  // First we check in the local buffer.
+  llvm::Value *indexPlusOne
+    = Builder.CreateAdd(index, llvm::ConstantInt::get(UnsignedLongLTy, 1));
+
+  // If we haven't overrun the buffer yet, we can continue.
+  Builder.CreateCondBr(Builder.CreateICmpULT(indexPlusOne, count),
+                       LoopBodyBB, FetchMoreBB);
+
+  index->addIncoming(indexPlusOne, AfterBody.getBlock());
+  count->addIncoming(count, AfterBody.getBlock());
+
+  // Otherwise, we have to fetch more elements.
+  EmitBlock(FetchMoreBB);
+
+  CountRV =
+    CGM.getObjCRuntime().GenerateMessageSend(*this, ReturnValueSlot(),
+                                             getContext().UnsignedLongTy,
+                                             FastEnumSel,
+                                             Collection, Args);
+
+  // If we got a zero count, we're done.
+  llvm::Value *refetchCount = CountRV.getScalarVal();
+
+  // (note that the message send might split FetchMoreBB)
+  index->addIncoming(zero, Builder.GetInsertBlock());
+  count->addIncoming(refetchCount, Builder.GetInsertBlock());
+
+  Builder.CreateCondBr(Builder.CreateICmpEQ(refetchCount, zero),
+                       EmptyBB, LoopBodyBB);
+
+  // No more elements.
+  EmitBlock(EmptyBB);
+
+  if (!elementIsVariable) {
+    // If the element was not a declaration, set it to be null.
+
+    llvm::Value *null = llvm::Constant::getNullValue(convertedElementType);
+    elementLValue = EmitLValue(cast<Expr>(S.getElement()));
+    EmitStoreThroughLValue(RValue::get(null), elementLValue);
+  }
+
+  if (DI)
+    DI->EmitLexicalBlockEnd(Builder, S.getSourceRange().getEnd());
+
+  // Leave the cleanup we entered in ARC.
+  if (getLangOpts().ObjCAutoRefCount)
+    PopCleanupBlock();
+
+  EmitBlock(LoopEnd.getBlock());
+}
+
+void CodeGenFunction::EmitObjCAtTryStmt(const ObjCAtTryStmt &S) {
+  CGM.getObjCRuntime().EmitTryStmt(*this, S);
+}
+
+void CodeGenFunction::EmitObjCAtThrowStmt(const ObjCAtThrowStmt &S) {
+  CGM.getObjCRuntime().EmitThrowStmt(*this, S);
+}
+
+void CodeGenFunction::EmitObjCAtSynchronizedStmt(
+                                              const ObjCAtSynchronizedStmt &S) {
+  CGM.getObjCRuntime().EmitSynchronizedStmt(*this, S);
+}
+
+/// Produce the code for a CK_ARCProduceObject.  Just does a
+/// primitive retain.
+llvm::Value *CodeGenFunction::EmitObjCProduceObject(QualType type,
+                                                    llvm::Value *value) {
+  return EmitARCRetain(type, value);
+}
+
+namespace {
+  struct CallObjCRelease : EHScopeStack::Cleanup {
+    CallObjCRelease(llvm::Value *object) : object(object) {}
+    llvm::Value *object;
+
+    void Emit(CodeGenFunction &CGF, Flags flags) {
+      CGF.EmitARCRelease(object, /*precise*/ true);
+    }
+  };
+}
+
+/// Produce the code for a CK_ARCConsumeObject.  Does a primitive
+/// release at the end of the full-expression.
+llvm::Value *CodeGenFunction::EmitObjCConsumeObject(QualType type,
+                                                    llvm::Value *object) {
+  // If we're in a conditional branch, we need to make the cleanup
+  // conditional.
+  pushFullExprCleanup<CallObjCRelease>(getARCCleanupKind(), object);
+  return object;
+}
+
+llvm::Value *CodeGenFunction::EmitObjCExtendObjectLifetime(QualType type,
+                                                           llvm::Value *value) {
+  return EmitARCRetainAutorelease(type, value);
+}
+
+
+static llvm::Constant *createARCRuntimeFunction(CodeGenModule &CGM,
+                                                llvm::FunctionType *type,
+                                                StringRef fnName) {
+  llvm::Constant *fn = CGM.CreateRuntimeFunction(type, fnName);
+
+  // In -fobjc-no-arc-runtime, emit weak references to the runtime
+  // support library.
+  if (!CGM.getCodeGenOpts().ObjCRuntimeHasARC)
+    if (llvm::Function *f = dyn_cast<llvm::Function>(fn))
+      f->setLinkage(llvm::Function::ExternalWeakLinkage);
+
+  return fn;
+}
+
+/// Perform an operation having the signature
+///   i8* (i8*)
+/// where a null input causes a no-op and returns null.
+static llvm::Value *emitARCValueOperation(CodeGenFunction &CGF,
+                                          llvm::Value *value,
+                                          llvm::Constant *&fn,
+                                          StringRef fnName) {
+  if (isa<llvm::ConstantPointerNull>(value)) return value;
+
+  if (!fn) {
+    std::vector<llvm::Type*> args(1, CGF.Int8PtrTy);
+    llvm::FunctionType *fnType =
+      llvm::FunctionType::get(CGF.Int8PtrTy, args, false);
+    fn = createARCRuntimeFunction(CGF.CGM, fnType, fnName);
+  }
+
+  // Cast the argument to 'id'.
+  llvm::Type *origType = value->getType();
+  value = CGF.Builder.CreateBitCast(value, CGF.Int8PtrTy);
+
+  // Call the function.
+  llvm::CallInst *call = CGF.Builder.CreateCall(fn, value);
+  call->setDoesNotThrow();
+
+  // Cast the result back to the original type.
+  return CGF.Builder.CreateBitCast(call, origType);
+}
+
+/// Perform an operation having the following signature:
+///   i8* (i8**)
+static llvm::Value *emitARCLoadOperation(CodeGenFunction &CGF,
+                                         llvm::Value *addr,
+                                         llvm::Constant *&fn,
+                                         StringRef fnName) {
+  if (!fn) {
+    std::vector<llvm::Type*> args(1, CGF.Int8PtrPtrTy);
+    llvm::FunctionType *fnType =
+      llvm::FunctionType::get(CGF.Int8PtrTy, args, false);
+    fn = createARCRuntimeFunction(CGF.CGM, fnType, fnName);
+  }
+
+  // Cast the argument to 'id*'.
+  llvm::Type *origType = addr->getType();
+  addr = CGF.Builder.CreateBitCast(addr, CGF.Int8PtrPtrTy);
+
+  // Call the function.
+  llvm::CallInst *call = CGF.Builder.CreateCall(fn, addr);
+  call->setDoesNotThrow();
+
+  // Cast the result back to a dereference of the original type.
+  llvm::Value *result = call;
+  if (origType != CGF.Int8PtrPtrTy)
+    result = CGF.Builder.CreateBitCast(result,
+                        cast<llvm::PointerType>(origType)->getElementType());
+
+  return result;
+}
+
+/// Perform an operation having the following signature:
+///   i8* (i8**, i8*)
+static llvm::Value *emitARCStoreOperation(CodeGenFunction &CGF,
+                                          llvm::Value *addr,
+                                          llvm::Value *value,
+                                          llvm::Constant *&fn,
+                                          StringRef fnName,
+                                          bool ignored) {
+  assert(cast<llvm::PointerType>(addr->getType())->getElementType()
+           == value->getType());
+
+  if (!fn) {
+    llvm::Type *argTypes[] = { CGF.Int8PtrPtrTy, CGF.Int8PtrTy };
+
+    llvm::FunctionType *fnType
+      = llvm::FunctionType::get(CGF.Int8PtrTy, argTypes, false);
+    fn = createARCRuntimeFunction(CGF.CGM, fnType, fnName);
+  }
+
+  llvm::Type *origType = value->getType();
+
+  addr = CGF.Builder.CreateBitCast(addr, CGF.Int8PtrPtrTy);
+  value = CGF.Builder.CreateBitCast(value, CGF.Int8PtrTy);
+    
+  llvm::CallInst *result = CGF.Builder.CreateCall2(fn, addr, value);
+  result->setDoesNotThrow();
+
+  if (ignored) return 0;
+
+  return CGF.Builder.CreateBitCast(result, origType);
+}
+
+/// Perform an operation having the following signature:
+///   void (i8**, i8**)
+static void emitARCCopyOperation(CodeGenFunction &CGF,
+                                 llvm::Value *dst,
+                                 llvm::Value *src,
+                                 llvm::Constant *&fn,
+                                 StringRef fnName) {
+  assert(dst->getType() == src->getType());
+
+  if (!fn) {
+    std::vector<llvm::Type*> argTypes(2, CGF.Int8PtrPtrTy);
+    llvm::FunctionType *fnType
+      = llvm::FunctionType::get(CGF.Builder.getVoidTy(), argTypes, false);
+    fn = createARCRuntimeFunction(CGF.CGM, fnType, fnName);
+  }
+
+  dst = CGF.Builder.CreateBitCast(dst, CGF.Int8PtrPtrTy);
+  src = CGF.Builder.CreateBitCast(src, CGF.Int8PtrPtrTy);
+    
+  llvm::CallInst *result = CGF.Builder.CreateCall2(fn, dst, src);
+  result->setDoesNotThrow();
+}
+
+/// Produce the code to do a retain.  Based on the type, calls one of:
+///   call i8* @objc_retain(i8* %value)
+///   call i8* @objc_retainBlock(i8* %value)
+llvm::Value *CodeGenFunction::EmitARCRetain(QualType type, llvm::Value *value) {
+  if (type->isBlockPointerType())
+    return EmitARCRetainBlock(value, /*mandatory*/ false);
+  else
+    return EmitARCRetainNonBlock(value);
+}
+
+/// Retain the given object, with normal retain semantics.
+///   call i8* @objc_retain(i8* %value)
+llvm::Value *CodeGenFunction::EmitARCRetainNonBlock(llvm::Value *value) {
+  return emitARCValueOperation(*this, value,
+                               CGM.getARCEntrypoints().objc_retain,
+                               "objc_retain");
+}
+
+/// Retain the given block, with _Block_copy semantics.
+///   call i8* @objc_retainBlock(i8* %value)
+///
+/// \param mandatory - If false, emit the call with metadata
+/// indicating that it's okay for the optimizer to eliminate this call
+/// if it can prove that the block never escapes except down the stack.
+llvm::Value *CodeGenFunction::EmitARCRetainBlock(llvm::Value *value,
+                                                 bool mandatory) {
+  llvm::Value *result
+    = emitARCValueOperation(*this, value,
+                            CGM.getARCEntrypoints().objc_retainBlock,
+                            "objc_retainBlock");
+
+  // If the copy isn't mandatory, add !clang.arc.copy_on_escape to
+  // tell the optimizer that it doesn't need to do this copy if the
+  // block doesn't escape, where being passed as an argument doesn't
+  // count as escaping.
+  if (!mandatory && isa<llvm::Instruction>(result)) {
+    llvm::CallInst *call
+      = cast<llvm::CallInst>(result->stripPointerCasts());
+    assert(call->getCalledValue() == CGM.getARCEntrypoints().objc_retainBlock);
+
+    SmallVector<llvm::Value*,1> args;
+    call->setMetadata("clang.arc.copy_on_escape",
+                      llvm::MDNode::get(Builder.getContext(), args));
+  }
+
+  return result;
+}
+
+/// Retain the given object which is the result of a function call.
+///   call i8* @objc_retainAutoreleasedReturnValue(i8* %value)
+///
+/// Yes, this function name is one character away from a different
+/// call with completely different semantics.
+llvm::Value *
+CodeGenFunction::EmitARCRetainAutoreleasedReturnValue(llvm::Value *value) {
+  // Fetch the void(void) inline asm which marks that we're going to
+  // retain the autoreleased return value.
+  llvm::InlineAsm *&marker
+    = CGM.getARCEntrypoints().retainAutoreleasedReturnValueMarker;
+  if (!marker) {
+    StringRef assembly
+      = CGM.getTargetCodeGenInfo()
+           .getARCRetainAutoreleasedReturnValueMarker();
+
+    // If we have an empty assembly string, there's nothing to do.
+    if (assembly.empty()) {
+
+    // Otherwise, at -O0, build an inline asm that we're going to call
+    // in a moment.
+    } else if (CGM.getCodeGenOpts().OptimizationLevel == 0) {
+      llvm::FunctionType *type =
+        llvm::FunctionType::get(VoidTy, /*variadic*/false);
+      
+      marker = llvm::InlineAsm::get(type, assembly, "", /*sideeffects*/ true);
+
+    // If we're at -O1 and above, we don't want to litter the code
+    // with this marker yet, so leave a breadcrumb for the ARC
+    // optimizer to pick up.
+    } else {
+      llvm::NamedMDNode *metadata =
+        CGM.getModule().getOrInsertNamedMetadata(
+                            "clang.arc.retainAutoreleasedReturnValueMarker");
+      assert(metadata->getNumOperands() <= 1);
+      if (metadata->getNumOperands() == 0) {
+        llvm::Value *string = llvm::MDString::get(getLLVMContext(), assembly);
+        metadata->addOperand(llvm::MDNode::get(getLLVMContext(), string));
+      }
+    }
+  }
+
+  // Call the marker asm if we made one, which we do only at -O0.
+  if (marker) Builder.CreateCall(marker);
+
+  return emitARCValueOperation(*this, value,
+                     CGM.getARCEntrypoints().objc_retainAutoreleasedReturnValue,
+                               "objc_retainAutoreleasedReturnValue");
+}
+
+/// Release the given object.
+///   call void @objc_release(i8* %value)
+void CodeGenFunction::EmitARCRelease(llvm::Value *value, bool precise) {
+  if (isa<llvm::ConstantPointerNull>(value)) return;
+
+  llvm::Constant *&fn = CGM.getARCEntrypoints().objc_release;
+  if (!fn) {
+    std::vector<llvm::Type*> args(1, Int8PtrTy);
+    llvm::FunctionType *fnType =
+      llvm::FunctionType::get(Builder.getVoidTy(), args, false);
+    fn = createARCRuntimeFunction(CGM, fnType, "objc_release");
+  }
+
+  // Cast the argument to 'id'.
+  value = Builder.CreateBitCast(value, Int8PtrTy);
+
+  // Call objc_release.
+  llvm::CallInst *call = Builder.CreateCall(fn, value);
+  call->setDoesNotThrow();
+
+  if (!precise) {
+    SmallVector<llvm::Value*,1> args;
+    call->setMetadata("clang.imprecise_release",
+                      llvm::MDNode::get(Builder.getContext(), args));
+  }
+}
+
+/// Store into a strong object.  Always calls this:
+///   call void @objc_storeStrong(i8** %addr, i8* %value)
+llvm::Value *CodeGenFunction::EmitARCStoreStrongCall(llvm::Value *addr,
+                                                     llvm::Value *value,
+                                                     bool ignored) {
+  assert(cast<llvm::PointerType>(addr->getType())->getElementType()
+           == value->getType());
+
+  llvm::Constant *&fn = CGM.getARCEntrypoints().objc_storeStrong;
+  if (!fn) {
+    llvm::Type *argTypes[] = { Int8PtrPtrTy, Int8PtrTy };
+    llvm::FunctionType *fnType
+      = llvm::FunctionType::get(Builder.getVoidTy(), argTypes, false);
+    fn = createARCRuntimeFunction(CGM, fnType, "objc_storeStrong");
+  }
+
+  addr = Builder.CreateBitCast(addr, Int8PtrPtrTy);
+  llvm::Value *castValue = Builder.CreateBitCast(value, Int8PtrTy);
+  
+  Builder.CreateCall2(fn, addr, castValue)->setDoesNotThrow();
+
+  if (ignored) return 0;
+  return value;
+}
+
+/// Store into a strong object.  Sometimes calls this:
+///   call void @objc_storeStrong(i8** %addr, i8* %value)
+/// Other times, breaks it down into components.
+llvm::Value *CodeGenFunction::EmitARCStoreStrong(LValue dst,
+                                                 llvm::Value *newValue,
+                                                 bool ignored) {
+  QualType type = dst.getType();
+  bool isBlock = type->isBlockPointerType();
+
+  // Use a store barrier at -O0 unless this is a block type or the
+  // lvalue is inadequately aligned.
+  if (shouldUseFusedARCCalls() &&
+      !isBlock &&
+      (dst.getAlignment().isZero() ||
+       dst.getAlignment() >= CharUnits::fromQuantity(PointerAlignInBytes))) {
+    return EmitARCStoreStrongCall(dst.getAddress(), newValue, ignored);
+  }
+
+  // Otherwise, split it out.
+
+  // Retain the new value.
+  newValue = EmitARCRetain(type, newValue);
+
+  // Read the old value.
+  llvm::Value *oldValue = EmitLoadOfScalar(dst);
+
+  // Store.  We do this before the release so that any deallocs won't
+  // see the old value.
+  EmitStoreOfScalar(newValue, dst);
+
+  // Finally, release the old value.
+  EmitARCRelease(oldValue, /*precise*/ false);
+
+  return newValue;
+}
+
+/// Autorelease the given object.
+///   call i8* @objc_autorelease(i8* %value)
+llvm::Value *CodeGenFunction::EmitARCAutorelease(llvm::Value *value) {
+  return emitARCValueOperation(*this, value,
+                               CGM.getARCEntrypoints().objc_autorelease,
+                               "objc_autorelease");
+}
+
+/// Autorelease the given object.
+///   call i8* @objc_autoreleaseReturnValue(i8* %value)
+llvm::Value *
+CodeGenFunction::EmitARCAutoreleaseReturnValue(llvm::Value *value) {
+  return emitARCValueOperation(*this, value,
+                            CGM.getARCEntrypoints().objc_autoreleaseReturnValue,
+                               "objc_autoreleaseReturnValue");
+}
+
+/// Do a fused retain/autorelease of the given object.
+///   call i8* @objc_retainAutoreleaseReturnValue(i8* %value)
+llvm::Value *
+CodeGenFunction::EmitARCRetainAutoreleaseReturnValue(llvm::Value *value) {
+  return emitARCValueOperation(*this, value,
+                     CGM.getARCEntrypoints().objc_retainAutoreleaseReturnValue,
+                               "objc_retainAutoreleaseReturnValue");
+}
+
+/// Do a fused retain/autorelease of the given object.
+///   call i8* @objc_retainAutorelease(i8* %value)
+/// or
+///   %retain = call i8* @objc_retainBlock(i8* %value)
+///   call i8* @objc_autorelease(i8* %retain)
+llvm::Value *CodeGenFunction::EmitARCRetainAutorelease(QualType type,
+                                                       llvm::Value *value) {
+  if (!type->isBlockPointerType())
+    return EmitARCRetainAutoreleaseNonBlock(value);
+
+  if (isa<llvm::ConstantPointerNull>(value)) return value;
+
+  llvm::Type *origType = value->getType();
+  value = Builder.CreateBitCast(value, Int8PtrTy);
+  value = EmitARCRetainBlock(value, /*mandatory*/ true);
+  value = EmitARCAutorelease(value);
+  return Builder.CreateBitCast(value, origType);
+}
+
+/// Do a fused retain/autorelease of the given object.
+///   call i8* @objc_retainAutorelease(i8* %value)
+llvm::Value *
+CodeGenFunction::EmitARCRetainAutoreleaseNonBlock(llvm::Value *value) {
+  return emitARCValueOperation(*this, value,
+                               CGM.getARCEntrypoints().objc_retainAutorelease,
+                               "objc_retainAutorelease");
+}
+
+/// i8* @objc_loadWeak(i8** %addr)
+/// Essentially objc_autorelease(objc_loadWeakRetained(addr)).
+llvm::Value *CodeGenFunction::EmitARCLoadWeak(llvm::Value *addr) {
+  return emitARCLoadOperation(*this, addr,
+                              CGM.getARCEntrypoints().objc_loadWeak,
+                              "objc_loadWeak");
+}
+
+/// i8* @objc_loadWeakRetained(i8** %addr)
+llvm::Value *CodeGenFunction::EmitARCLoadWeakRetained(llvm::Value *addr) {
+  return emitARCLoadOperation(*this, addr,
+                              CGM.getARCEntrypoints().objc_loadWeakRetained,
+                              "objc_loadWeakRetained");
+}
+
+/// i8* @objc_storeWeak(i8** %addr, i8* %value)
+/// Returns %value.
+llvm::Value *CodeGenFunction::EmitARCStoreWeak(llvm::Value *addr,
+                                               llvm::Value *value,
+                                               bool ignored) {
+  return emitARCStoreOperation(*this, addr, value,
+                               CGM.getARCEntrypoints().objc_storeWeak,
+                               "objc_storeWeak", ignored);
+}
+
+/// i8* @objc_initWeak(i8** %addr, i8* %value)
+/// Returns %value.  %addr is known to not have a current weak entry.
+/// Essentially equivalent to:
+///   *addr = nil; objc_storeWeak(addr, value);
+void CodeGenFunction::EmitARCInitWeak(llvm::Value *addr, llvm::Value *value) {
+  // If we're initializing to null, just write null to memory; no need
+  // to get the runtime involved.  But don't do this if optimization
+  // is enabled, because accounting for this would make the optimizer
+  // much more complicated.
+  if (isa<llvm::ConstantPointerNull>(value) &&
+      CGM.getCodeGenOpts().OptimizationLevel == 0) {
+    Builder.CreateStore(value, addr);
+    return;
+  }
+
+  emitARCStoreOperation(*this, addr, value,
+                        CGM.getARCEntrypoints().objc_initWeak,
+                        "objc_initWeak", /*ignored*/ true);
+}
+
+/// void @objc_destroyWeak(i8** %addr)
+/// Essentially objc_storeWeak(addr, nil).
+void CodeGenFunction::EmitARCDestroyWeak(llvm::Value *addr) {
+  llvm::Constant *&fn = CGM.getARCEntrypoints().objc_destroyWeak;
+  if (!fn) {
+    std::vector<llvm::Type*> args(1, Int8PtrPtrTy);
+    llvm::FunctionType *fnType =
+      llvm::FunctionType::get(Builder.getVoidTy(), args, false);
+    fn = createARCRuntimeFunction(CGM, fnType, "objc_destroyWeak");
+  }
+
+  // Cast the argument to 'id*'.
+  addr = Builder.CreateBitCast(addr, Int8PtrPtrTy);
+
+  llvm::CallInst *call = Builder.CreateCall(fn, addr);
+  call->setDoesNotThrow();
+}
+
+/// void @objc_moveWeak(i8** %dest, i8** %src)
+/// Disregards the current value in %dest.  Leaves %src pointing to nothing.
+/// Essentially (objc_copyWeak(dest, src), objc_destroyWeak(src)).
+void CodeGenFunction::EmitARCMoveWeak(llvm::Value *dst, llvm::Value *src) {
+  emitARCCopyOperation(*this, dst, src,
+                       CGM.getARCEntrypoints().objc_moveWeak,
+                       "objc_moveWeak");
+}
+
+/// void @objc_copyWeak(i8** %dest, i8** %src)
+/// Disregards the current value in %dest.  Essentially
+///   objc_release(objc_initWeak(dest, objc_readWeakRetained(src)))
+void CodeGenFunction::EmitARCCopyWeak(llvm::Value *dst, llvm::Value *src) {
+  emitARCCopyOperation(*this, dst, src,
+                       CGM.getARCEntrypoints().objc_copyWeak,
+                       "objc_copyWeak");
+}
+
+/// Produce the code to do a objc_autoreleasepool_push.
+///   call i8* @objc_autoreleasePoolPush(void)
+llvm::Value *CodeGenFunction::EmitObjCAutoreleasePoolPush() {
+  llvm::Constant *&fn = CGM.getRREntrypoints().objc_autoreleasePoolPush;
+  if (!fn) {
+    llvm::FunctionType *fnType =
+      llvm::FunctionType::get(Int8PtrTy, false);
+    fn = createARCRuntimeFunction(CGM, fnType, "objc_autoreleasePoolPush");
+  }
+
+  llvm::CallInst *call = Builder.CreateCall(fn);
+  call->setDoesNotThrow();
+
+  return call;
+}
+
+/// Produce the code to do a primitive release.
+///   call void @objc_autoreleasePoolPop(i8* %ptr)
+void CodeGenFunction::EmitObjCAutoreleasePoolPop(llvm::Value *value) {
+  assert(value->getType() == Int8PtrTy);
+
+  llvm::Constant *&fn = CGM.getRREntrypoints().objc_autoreleasePoolPop;
+  if (!fn) {
+    std::vector<llvm::Type*> args(1, Int8PtrTy);
+    llvm::FunctionType *fnType =
+      llvm::FunctionType::get(Builder.getVoidTy(), args, false);
+
+    // We don't want to use a weak import here; instead we should not
+    // fall into this path.
+    fn = createARCRuntimeFunction(CGM, fnType, "objc_autoreleasePoolPop");
+  }
+
+  llvm::CallInst *call = Builder.CreateCall(fn, value);
+  call->setDoesNotThrow();
+}
+
+/// Produce the code to do an MRR version objc_autoreleasepool_push.
+/// Which is: [[NSAutoreleasePool alloc] init];
+/// Where alloc is declared as: + (id) alloc; in NSAutoreleasePool class.
+/// init is declared as: - (id) init; in its NSObject super class.
+///
+llvm::Value *CodeGenFunction::EmitObjCMRRAutoreleasePoolPush() {
+  CGObjCRuntime &Runtime = CGM.getObjCRuntime();
+  llvm::Value *Receiver = Runtime.EmitNSAutoreleasePoolClassRef(Builder);
+  // [NSAutoreleasePool alloc]
+  IdentifierInfo *II = &CGM.getContext().Idents.get("alloc");
+  Selector AllocSel = getContext().Selectors.getSelector(0, &II);
+  CallArgList Args;
+  RValue AllocRV =  
+    Runtime.GenerateMessageSend(*this, ReturnValueSlot(), 
+                                getContext().getObjCIdType(),
+                                AllocSel, Receiver, Args); 
+
+  // [Receiver init]
+  Receiver = AllocRV.getScalarVal();
+  II = &CGM.getContext().Idents.get("init");
+  Selector InitSel = getContext().Selectors.getSelector(0, &II);
+  RValue InitRV =
+    Runtime.GenerateMessageSend(*this, ReturnValueSlot(),
+                                getContext().getObjCIdType(),
+                                InitSel, Receiver, Args); 
+  return InitRV.getScalarVal();
+}
+
+/// Produce the code to do a primitive release.
+/// [tmp drain];
+void CodeGenFunction::EmitObjCMRRAutoreleasePoolPop(llvm::Value *Arg) {
+  IdentifierInfo *II = &CGM.getContext().Idents.get("drain");
+  Selector DrainSel = getContext().Selectors.getSelector(0, &II);
+  CallArgList Args;
+  CGM.getObjCRuntime().GenerateMessageSend(*this, ReturnValueSlot(),
+                              getContext().VoidTy, DrainSel, Arg, Args); 
+}
+
+void CodeGenFunction::destroyARCStrongPrecise(CodeGenFunction &CGF,
+                                              llvm::Value *addr,
+                                              QualType type) {
+  llvm::Value *ptr = CGF.Builder.CreateLoad(addr, "strongdestroy");
+  CGF.EmitARCRelease(ptr, /*precise*/ true);
+}
+
+void CodeGenFunction::destroyARCStrongImprecise(CodeGenFunction &CGF,
+                                                llvm::Value *addr,
+                                                QualType type) {
+  llvm::Value *ptr = CGF.Builder.CreateLoad(addr, "strongdestroy");
+  CGF.EmitARCRelease(ptr, /*precise*/ false);  
+}
+
+void CodeGenFunction::destroyARCWeak(CodeGenFunction &CGF,
+                                     llvm::Value *addr,
+                                     QualType type) {
+  CGF.EmitARCDestroyWeak(addr);
+}
+
+namespace {
+  struct CallObjCAutoreleasePoolObject : EHScopeStack::Cleanup {
+    llvm::Value *Token;
+
+    CallObjCAutoreleasePoolObject(llvm::Value *token) : Token(token) {}
+
+    void Emit(CodeGenFunction &CGF, Flags flags) {
+      CGF.EmitObjCAutoreleasePoolPop(Token);
+    }
+  };
+  struct CallObjCMRRAutoreleasePoolObject : EHScopeStack::Cleanup {
+    llvm::Value *Token;
+
+    CallObjCMRRAutoreleasePoolObject(llvm::Value *token) : Token(token) {}
+
+    void Emit(CodeGenFunction &CGF, Flags flags) {
+      CGF.EmitObjCMRRAutoreleasePoolPop(Token);
+    }
+  };
+}
+
+void CodeGenFunction::EmitObjCAutoreleasePoolCleanup(llvm::Value *Ptr) {
+  if (CGM.getLangOpts().ObjCAutoRefCount)
+    EHStack.pushCleanup<CallObjCAutoreleasePoolObject>(NormalCleanup, Ptr);
+  else
+    EHStack.pushCleanup<CallObjCMRRAutoreleasePoolObject>(NormalCleanup, Ptr);
+}
+
+static TryEmitResult tryEmitARCRetainLoadOfScalar(CodeGenFunction &CGF,
+                                                  LValue lvalue,
+                                                  QualType type) {
+  switch (type.getObjCLifetime()) {
+  case Qualifiers::OCL_None:
+  case Qualifiers::OCL_ExplicitNone:
+  case Qualifiers::OCL_Strong:
+  case Qualifiers::OCL_Autoreleasing:
+    return TryEmitResult(CGF.EmitLoadOfLValue(lvalue).getScalarVal(),
+                         false);
+
+  case Qualifiers::OCL_Weak:
+    return TryEmitResult(CGF.EmitARCLoadWeakRetained(lvalue.getAddress()),
+                         true);
+  }
+
+  llvm_unreachable("impossible lifetime!");
+}
+
+static TryEmitResult tryEmitARCRetainLoadOfScalar(CodeGenFunction &CGF,
+                                                  const Expr *e) {
+  e = e->IgnoreParens();
+  QualType type = e->getType();
+
+  // If we're loading retained from a __strong xvalue, we can avoid 
+  // an extra retain/release pair by zeroing out the source of this
+  // "move" operation.
+  if (e->isXValue() &&
+      !type.isConstQualified() &&
+      type.getObjCLifetime() == Qualifiers::OCL_Strong) {
+    // Emit the lvalue.
+    LValue lv = CGF.EmitLValue(e);
+    
+    // Load the object pointer.
+    llvm::Value *result = CGF.EmitLoadOfLValue(lv).getScalarVal();
+    
+    // Set the source pointer to NULL.
+    CGF.EmitStoreOfScalar(getNullForVariable(lv.getAddress()), lv);
+    
+    return TryEmitResult(result, true);
+  }
+
+  // As a very special optimization, in ARC++, if the l-value is the
+  // result of a non-volatile assignment, do a simple retain of the
+  // result of the call to objc_storeWeak instead of reloading.
+  if (CGF.getLangOpts().CPlusPlus &&
+      !type.isVolatileQualified() &&
+      type.getObjCLifetime() == Qualifiers::OCL_Weak &&
+      isa<BinaryOperator>(e) &&
+      cast<BinaryOperator>(e)->getOpcode() == BO_Assign)
+    return TryEmitResult(CGF.EmitScalarExpr(e), false);
+
+  return tryEmitARCRetainLoadOfScalar(CGF, CGF.EmitLValue(e), type);
+}
+
+static llvm::Value *emitARCRetainAfterCall(CodeGenFunction &CGF,
+                                           llvm::Value *value);
+
+/// Given that the given expression is some sort of call (which does
+/// not return retained), emit a retain following it.
+static llvm::Value *emitARCRetainCall(CodeGenFunction &CGF, const Expr *e) {
+  llvm::Value *value = CGF.EmitScalarExpr(e);
+  return emitARCRetainAfterCall(CGF, value);
+}
+
+static llvm::Value *emitARCRetainAfterCall(CodeGenFunction &CGF,
+                                           llvm::Value *value) {
+  if (llvm::CallInst *call = dyn_cast<llvm::CallInst>(value)) {
+    CGBuilderTy::InsertPoint ip = CGF.Builder.saveIP();
+
+    // Place the retain immediately following the call.
+    CGF.Builder.SetInsertPoint(call->getParent(),
+                               ++llvm::BasicBlock::iterator(call));
+    value = CGF.EmitARCRetainAutoreleasedReturnValue(value);
+
+    CGF.Builder.restoreIP(ip);
+    return value;
+  } else if (llvm::InvokeInst *invoke = dyn_cast<llvm::InvokeInst>(value)) {
+    CGBuilderTy::InsertPoint ip = CGF.Builder.saveIP();
+
+    // Place the retain at the beginning of the normal destination block.
+    llvm::BasicBlock *BB = invoke->getNormalDest();
+    CGF.Builder.SetInsertPoint(BB, BB->begin());
+    value = CGF.EmitARCRetainAutoreleasedReturnValue(value);
+
+    CGF.Builder.restoreIP(ip);
+    return value;
+
+  // Bitcasts can arise because of related-result returns.  Rewrite
+  // the operand.
+  } else if (llvm::BitCastInst *bitcast = dyn_cast<llvm::BitCastInst>(value)) {
+    llvm::Value *operand = bitcast->getOperand(0);
+    operand = emitARCRetainAfterCall(CGF, operand);
+    bitcast->setOperand(0, operand);
+    return bitcast;
+
+  // Generic fall-back case.
+  } else {
+    // Retain using the non-block variant: we never need to do a copy
+    // of a block that's been returned to us.
+    return CGF.EmitARCRetainNonBlock(value);
+  }
+}
+
+/// Determine whether it might be important to emit a separate
+/// objc_retain_block on the result of the given expression, or
+/// whether it's okay to just emit it in a +1 context.
+static bool shouldEmitSeparateBlockRetain(const Expr *e) {
+  assert(e->getType()->isBlockPointerType());
+  e = e->IgnoreParens();
+
+  // For future goodness, emit block expressions directly in +1
+  // contexts if we can.
+  if (isa<BlockExpr>(e))
+    return false;
+
+  if (const CastExpr *cast = dyn_cast<CastExpr>(e)) {
+    switch (cast->getCastKind()) {
+    // Emitting these operations in +1 contexts is goodness.
+    case CK_LValueToRValue:
+    case CK_ARCReclaimReturnedObject:
+    case CK_ARCConsumeObject:
+    case CK_ARCProduceObject:
+      return false;
+
+    // These operations preserve a block type.
+    case CK_NoOp:
+    case CK_BitCast:
+      return shouldEmitSeparateBlockRetain(cast->getSubExpr());
+
+    // These operations are known to be bad (or haven't been considered).
+    case CK_AnyPointerToBlockPointerCast:
+    default:
+      return true;
+    }
+  }
+
+  return true;
+}
+
+/// Try to emit a PseudoObjectExpr at +1.
+///
+/// This massively duplicates emitPseudoObjectRValue.
+static TryEmitResult tryEmitARCRetainPseudoObject(CodeGenFunction &CGF,
+                                                  const PseudoObjectExpr *E) {
+  llvm::SmallVector<CodeGenFunction::OpaqueValueMappingData, 4> opaques;
+
+  // Find the result expression.
+  const Expr *resultExpr = E->getResultExpr();
+  assert(resultExpr);
+  TryEmitResult result;
+
+  for (PseudoObjectExpr::const_semantics_iterator
+         i = E->semantics_begin(), e = E->semantics_end(); i != e; ++i) {
+    const Expr *semantic = *i;
+
+    // If this semantic expression is an opaque value, bind it
+    // to the result of its source expression.
+    if (const OpaqueValueExpr *ov = dyn_cast<OpaqueValueExpr>(semantic)) {
+      typedef CodeGenFunction::OpaqueValueMappingData OVMA;
+      OVMA opaqueData;
+
+      // If this semantic is the result of the pseudo-object
+      // expression, try to evaluate the source as +1.
+      if (ov == resultExpr) {
+        assert(!OVMA::shouldBindAsLValue(ov));
+        result = tryEmitARCRetainScalarExpr(CGF, ov->getSourceExpr());
+        opaqueData = OVMA::bind(CGF, ov, RValue::get(result.getPointer()));
+
+      // Otherwise, just bind it.
+      } else {
+        opaqueData = OVMA::bind(CGF, ov, ov->getSourceExpr());
+      }
+      opaques.push_back(opaqueData);
+
+    // Otherwise, if the expression is the result, evaluate it
+    // and remember the result.
+    } else if (semantic == resultExpr) {
+      result = tryEmitARCRetainScalarExpr(CGF, semantic);
+
+    // Otherwise, evaluate the expression in an ignored context.
+    } else {
+      CGF.EmitIgnoredExpr(semantic);
+    }
+  }
+
+  // Unbind all the opaques now.
+  for (unsigned i = 0, e = opaques.size(); i != e; ++i)
+    opaques[i].unbind(CGF);
+
+  return result;
+}
+
+static TryEmitResult
+tryEmitARCRetainScalarExpr(CodeGenFunction &CGF, const Expr *e) {
+  // Look through cleanups.
+  if (const ExprWithCleanups *cleanups = dyn_cast<ExprWithCleanups>(e)) {
+    CGF.enterFullExpression(cleanups);
+    CodeGenFunction::RunCleanupsScope scope(CGF);
+    return tryEmitARCRetainScalarExpr(CGF, cleanups->getSubExpr());
+  }
+
+  // The desired result type, if it differs from the type of the
+  // ultimate opaque expression.
+  llvm::Type *resultType = 0;
+
+  while (true) {
+    e = e->IgnoreParens();
+
+    // There's a break at the end of this if-chain;  anything
+    // that wants to keep looping has to explicitly continue.
+    if (const CastExpr *ce = dyn_cast<CastExpr>(e)) {
+      switch (ce->getCastKind()) {
+      // No-op casts don't change the type, so we just ignore them.
+      case CK_NoOp:
+        e = ce->getSubExpr();
+        continue;
+
+      case CK_LValueToRValue: {
+        TryEmitResult loadResult
+          = tryEmitARCRetainLoadOfScalar(CGF, ce->getSubExpr());
+        if (resultType) {
+          llvm::Value *value = loadResult.getPointer();
+          value = CGF.Builder.CreateBitCast(value, resultType);
+          loadResult.setPointer(value);
+        }
+        return loadResult;
+      }
+
+      // These casts can change the type, so remember that and
+      // soldier on.  We only need to remember the outermost such
+      // cast, though.
+      case CK_CPointerToObjCPointerCast:
+      case CK_BlockPointerToObjCPointerCast:
+      case CK_AnyPointerToBlockPointerCast:
+      case CK_BitCast:
+        if (!resultType)
+          resultType = CGF.ConvertType(ce->getType());
+        e = ce->getSubExpr();
+        assert(e->getType()->hasPointerRepresentation());
+        continue;
+
+      // For consumptions, just emit the subexpression and thus elide
+      // the retain/release pair.
+      case CK_ARCConsumeObject: {
+        llvm::Value *result = CGF.EmitScalarExpr(ce->getSubExpr());
+        if (resultType) result = CGF.Builder.CreateBitCast(result, resultType);
+        return TryEmitResult(result, true);
+      }
+
+      // Block extends are net +0.  Naively, we could just recurse on
+      // the subexpression, but actually we need to ensure that the
+      // value is copied as a block, so there's a little filter here.
+      case CK_ARCExtendBlockObject: {
+        llvm::Value *result; // will be a +0 value
+
+        // If we can't safely assume the sub-expression will produce a
+        // block-copied value, emit the sub-expression at +0.
+        if (shouldEmitSeparateBlockRetain(ce->getSubExpr())) {
+          result = CGF.EmitScalarExpr(ce->getSubExpr());
+
+        // Otherwise, try to emit the sub-expression at +1 recursively.
+        } else {
+          TryEmitResult subresult
+            = tryEmitARCRetainScalarExpr(CGF, ce->getSubExpr());
+          result = subresult.getPointer();
+
+          // If that produced a retained value, just use that,
+          // possibly casting down.
+          if (subresult.getInt()) {
+            if (resultType)
+              result = CGF.Builder.CreateBitCast(result, resultType);
+            return TryEmitResult(result, true);
+          }
+
+          // Otherwise it's +0.
+        }
+
+        // Retain the object as a block, then cast down.
+        result = CGF.EmitARCRetainBlock(result, /*mandatory*/ true);
+        if (resultType) result = CGF.Builder.CreateBitCast(result, resultType);
+        return TryEmitResult(result, true);
+      }
+
+      // For reclaims, emit the subexpression as a retained call and
+      // skip the consumption.
+      case CK_ARCReclaimReturnedObject: {
+        llvm::Value *result = emitARCRetainCall(CGF, ce->getSubExpr());
+        if (resultType) result = CGF.Builder.CreateBitCast(result, resultType);
+        return TryEmitResult(result, true);
+      }
+
+      default:
+        break;
+      }
+
+    // Skip __extension__.
+    } else if (const UnaryOperator *op = dyn_cast<UnaryOperator>(e)) {
+      if (op->getOpcode() == UO_Extension) {
+        e = op->getSubExpr();
+        continue;
+      }
+
+    // For calls and message sends, use the retained-call logic.
+    // Delegate inits are a special case in that they're the only
+    // returns-retained expression that *isn't* surrounded by
+    // a consume.
+    } else if (isa<CallExpr>(e) ||
+               (isa<ObjCMessageExpr>(e) &&
+                !cast<ObjCMessageExpr>(e)->isDelegateInitCall())) {
+      llvm::Value *result = emitARCRetainCall(CGF, e);
+      if (resultType) result = CGF.Builder.CreateBitCast(result, resultType);
+      return TryEmitResult(result, true);
+
+    // Look through pseudo-object expressions.
+    } else if (const PseudoObjectExpr *pseudo = dyn_cast<PseudoObjectExpr>(e)) {
+      TryEmitResult result
+        = tryEmitARCRetainPseudoObject(CGF, pseudo);
+      if (resultType) {
+        llvm::Value *value = result.getPointer();
+        value = CGF.Builder.CreateBitCast(value, resultType);
+        result.setPointer(value);
+      }
+      return result;
+    }
+
+    // Conservatively halt the search at any other expression kind.
+    break;
+  }
+
+  // We didn't find an obvious production, so emit what we've got and
+  // tell the caller that we didn't manage to retain.
+  llvm::Value *result = CGF.EmitScalarExpr(e);
+  if (resultType) result = CGF.Builder.CreateBitCast(result, resultType);
+  return TryEmitResult(result, false);
+}
+
+static llvm::Value *emitARCRetainLoadOfScalar(CodeGenFunction &CGF,
+                                                LValue lvalue,
+                                                QualType type) {
+  TryEmitResult result = tryEmitARCRetainLoadOfScalar(CGF, lvalue, type);
+  llvm::Value *value = result.getPointer();
+  if (!result.getInt())
+    value = CGF.EmitARCRetain(type, value);
+  return value;
+}
+
+/// EmitARCRetainScalarExpr - Semantically equivalent to
+/// EmitARCRetainObject(e->getType(), EmitScalarExpr(e)), but making a
+/// best-effort attempt to peephole expressions that naturally produce
+/// retained objects.
+llvm::Value *CodeGenFunction::EmitARCRetainScalarExpr(const Expr *e) {
+  TryEmitResult result = tryEmitARCRetainScalarExpr(*this, e);
+  llvm::Value *value = result.getPointer();
+  if (!result.getInt())
+    value = EmitARCRetain(e->getType(), value);
+  return value;
+}
+
+llvm::Value *
+CodeGenFunction::EmitARCRetainAutoreleaseScalarExpr(const Expr *e) {
+  TryEmitResult result = tryEmitARCRetainScalarExpr(*this, e);
+  llvm::Value *value = result.getPointer();
+  if (result.getInt())
+    value = EmitARCAutorelease(value);
+  else
+    value = EmitARCRetainAutorelease(e->getType(), value);
+  return value;
+}
+
+llvm::Value *CodeGenFunction::EmitARCExtendBlockObject(const Expr *e) {
+  llvm::Value *result;
+  bool doRetain;
+
+  if (shouldEmitSeparateBlockRetain(e)) {
+    result = EmitScalarExpr(e);
+    doRetain = true;
+  } else {
+    TryEmitResult subresult = tryEmitARCRetainScalarExpr(*this, e);
+    result = subresult.getPointer();
+    doRetain = !subresult.getInt();
+  }
+
+  if (doRetain)
+    result = EmitARCRetainBlock(result, /*mandatory*/ true);
+  return EmitObjCConsumeObject(e->getType(), result);
+}
+
+llvm::Value *CodeGenFunction::EmitObjCThrowOperand(const Expr *expr) {
+  // In ARC, retain and autorelease the expression.
+  if (getLangOpts().ObjCAutoRefCount) {
+    // Do so before running any cleanups for the full-expression.
+    // tryEmitARCRetainScalarExpr does make an effort to do things
+    // inside cleanups, but there are crazy cases like
+    //   @throw A().foo;
+    // where a full retain+autorelease is required and would
+    // otherwise happen after the destructor for the temporary.
+    if (const ExprWithCleanups *ewc = dyn_cast<ExprWithCleanups>(expr)) {
+      enterFullExpression(ewc);
+      expr = ewc->getSubExpr();
+    }
+
+    CodeGenFunction::RunCleanupsScope cleanups(*this);
+    return EmitARCRetainAutoreleaseScalarExpr(expr);
+  }
+
+  // Otherwise, use the normal scalar-expression emission.  The
+  // exception machinery doesn't do anything special with the
+  // exception like retaining it, so there's no safety associated with
+  // only running cleanups after the throw has started, and when it
+  // matters it tends to be substantially inferior code.
+  return EmitScalarExpr(expr);
+}
+
+std::pair<LValue,llvm::Value*>
+CodeGenFunction::EmitARCStoreStrong(const BinaryOperator *e,
+                                    bool ignored) {
+  // Evaluate the RHS first.
+  TryEmitResult result = tryEmitARCRetainScalarExpr(*this, e->getRHS());
+  llvm::Value *value = result.getPointer();
+
+  bool hasImmediateRetain = result.getInt();
+
+  // If we didn't emit a retained object, and the l-value is of block
+  // type, then we need to emit the block-retain immediately in case
+  // it invalidates the l-value.
+  if (!hasImmediateRetain && e->getType()->isBlockPointerType()) {
+    value = EmitARCRetainBlock(value, /*mandatory*/ false);
+    hasImmediateRetain = true;
+  }
+
+  LValue lvalue = EmitLValue(e->getLHS());
+
+  // If the RHS was emitted retained, expand this.
+  if (hasImmediateRetain) {
+    llvm::Value *oldValue =
+      EmitLoadOfScalar(lvalue);
+    EmitStoreOfScalar(value, lvalue);
+    EmitARCRelease(oldValue, /*precise*/ false);
+  } else {
+    value = EmitARCStoreStrong(lvalue, value, ignored);
+  }
+
+  return std::pair<LValue,llvm::Value*>(lvalue, value);
+}
+
+std::pair<LValue,llvm::Value*>
+CodeGenFunction::EmitARCStoreAutoreleasing(const BinaryOperator *e) {
+  llvm::Value *value = EmitARCRetainAutoreleaseScalarExpr(e->getRHS());
+  LValue lvalue = EmitLValue(e->getLHS());
+
+  EmitStoreOfScalar(value, lvalue);
+
+  return std::pair<LValue,llvm::Value*>(lvalue, value);
+}
+
+void CodeGenFunction::EmitObjCAutoreleasePoolStmt(
+                                          const ObjCAutoreleasePoolStmt &ARPS) {
+  const Stmt *subStmt = ARPS.getSubStmt();
+  const CompoundStmt &S = cast<CompoundStmt>(*subStmt);
+
+  CGDebugInfo *DI = getDebugInfo();
+  if (DI)
+    DI->EmitLexicalBlockStart(Builder, S.getLBracLoc());
+
+  // Keep track of the current cleanup stack depth.
+  RunCleanupsScope Scope(*this);
+  if (CGM.getCodeGenOpts().ObjCRuntimeHasARC) {
+    llvm::Value *token = EmitObjCAutoreleasePoolPush();
+    EHStack.pushCleanup<CallObjCAutoreleasePoolObject>(NormalCleanup, token);
+  } else {
+    llvm::Value *token = EmitObjCMRRAutoreleasePoolPush();
+    EHStack.pushCleanup<CallObjCMRRAutoreleasePoolObject>(NormalCleanup, token);
+  }
+
+  for (CompoundStmt::const_body_iterator I = S.body_begin(),
+       E = S.body_end(); I != E; ++I)
+    EmitStmt(*I);
+
+  if (DI)
+    DI->EmitLexicalBlockEnd(Builder, S.getRBracLoc());
+}
+
+/// EmitExtendGCLifetime - Given a pointer to an Objective-C object,
+/// make sure it survives garbage collection until this point.
+void CodeGenFunction::EmitExtendGCLifetime(llvm::Value *object) {
+  // We just use an inline assembly.
+  llvm::FunctionType *extenderType
+    = llvm::FunctionType::get(VoidTy, VoidPtrTy, RequiredArgs::All);
+  llvm::Value *extender
+    = llvm::InlineAsm::get(extenderType,
+                           /* assembly */ "",
+                           /* constraints */ "r",
+                           /* side effects */ true);
+
+  object = Builder.CreateBitCast(object, VoidPtrTy);
+  Builder.CreateCall(extender, object)->setDoesNotThrow();
+}
+
+/// GenerateObjCAtomicSetterCopyHelperFunction - Given a c++ object type with
+/// non-trivial copy assignment function, produce following helper function.
+/// static void copyHelper(Ty *dest, const Ty *source) { *dest = *source; }
+///
+llvm::Constant *
+CodeGenFunction::GenerateObjCAtomicSetterCopyHelperFunction(
+                                        const ObjCPropertyImplDecl *PID) {
+  // FIXME. This api is for NeXt runtime only for now.
+  if (!getLangOpts().CPlusPlus || !getLangOpts().NeXTRuntime)
+    return 0;
+  QualType Ty = PID->getPropertyIvarDecl()->getType();
+  if (!Ty->isRecordType())
+    return 0;
+  const ObjCPropertyDecl *PD = PID->getPropertyDecl();
+  if ((!(PD->getPropertyAttributes() & ObjCPropertyDecl::OBJC_PR_atomic)))
+    return 0;
+  llvm::Constant * HelperFn = 0;
+  if (hasTrivialSetExpr(PID))
+    return 0;
+  assert(PID->getSetterCXXAssignment() && "SetterCXXAssignment - null");
+  if ((HelperFn = CGM.getAtomicSetterHelperFnMap(Ty)))
+    return HelperFn;
+  
+  ASTContext &C = getContext();
+  IdentifierInfo *II
+    = &CGM.getContext().Idents.get("__assign_helper_atomic_property_");
+  FunctionDecl *FD = FunctionDecl::Create(C,
+                                          C.getTranslationUnitDecl(),
+                                          SourceLocation(),
+                                          SourceLocation(), II, C.VoidTy, 0,
+                                          SC_Static,
+                                          SC_None,
+                                          false,
+                                          false);
+  
+  QualType DestTy = C.getPointerType(Ty);
+  QualType SrcTy = Ty;
+  SrcTy.addConst();
+  SrcTy = C.getPointerType(SrcTy);
+  
+  FunctionArgList args;
+  ImplicitParamDecl dstDecl(FD, SourceLocation(), 0, DestTy);
+  args.push_back(&dstDecl);
+  ImplicitParamDecl srcDecl(FD, SourceLocation(), 0, SrcTy);
+  args.push_back(&srcDecl);
+  
+  const CGFunctionInfo &FI =
+    CGM.getTypes().arrangeFunctionDeclaration(C.VoidTy, args,
+                                              FunctionType::ExtInfo(),
+                                              RequiredArgs::All);
+  
+  llvm::FunctionType *LTy = CGM.getTypes().GetFunctionType(FI);
+  
+  llvm::Function *Fn =
+    llvm::Function::Create(LTy, llvm::GlobalValue::InternalLinkage,
+                           "__assign_helper_atomic_property_",
+                           &CGM.getModule());
+  
+  if (CGM.getModuleDebugInfo())
+    DebugInfo = CGM.getModuleDebugInfo();
+  
+  
+  StartFunction(FD, C.VoidTy, Fn, FI, args, SourceLocation());
+  
+  DeclRefExpr DstExpr(&dstDecl, false, DestTy,
+                      VK_RValue, SourceLocation());
+  UnaryOperator DST(&DstExpr, UO_Deref, DestTy->getPointeeType(),
+                    VK_LValue, OK_Ordinary, SourceLocation());
+  
+  DeclRefExpr SrcExpr(&srcDecl, false, SrcTy,
+                      VK_RValue, SourceLocation());
+  UnaryOperator SRC(&SrcExpr, UO_Deref, SrcTy->getPointeeType(),
+                    VK_LValue, OK_Ordinary, SourceLocation());
+  
+  Expr *Args[2] = { &DST, &SRC };
+  CallExpr *CalleeExp = cast<CallExpr>(PID->getSetterCXXAssignment());
+  CXXOperatorCallExpr TheCall(C, OO_Equal, CalleeExp->getCallee(),
+                              Args, 2, DestTy->getPointeeType(), 
+                              VK_LValue, SourceLocation());
+  
+  EmitStmt(&TheCall);
+
+  FinishFunction();
+  HelperFn = llvm::ConstantExpr::getBitCast(Fn, VoidPtrTy);
+  CGM.setAtomicSetterHelperFnMap(Ty, HelperFn);
+  return HelperFn;
+}
+
+llvm::Constant *
+CodeGenFunction::GenerateObjCAtomicGetterCopyHelperFunction(
+                                            const ObjCPropertyImplDecl *PID) {
+  // FIXME. This api is for NeXt runtime only for now.
+  if (!getLangOpts().CPlusPlus || !getLangOpts().NeXTRuntime)
+    return 0;
+  const ObjCPropertyDecl *PD = PID->getPropertyDecl();
+  QualType Ty = PD->getType();
+  if (!Ty->isRecordType())
+    return 0;
+  if ((!(PD->getPropertyAttributes() & ObjCPropertyDecl::OBJC_PR_atomic)))
+    return 0;
+  llvm::Constant * HelperFn = 0;
+  
+  if (hasTrivialGetExpr(PID))
+    return 0;
+  assert(PID->getGetterCXXConstructor() && "getGetterCXXConstructor - null");
+  if ((HelperFn = CGM.getAtomicGetterHelperFnMap(Ty)))
+    return HelperFn;
+  
+  
+  ASTContext &C = getContext();
+  IdentifierInfo *II
+  = &CGM.getContext().Idents.get("__copy_helper_atomic_property_");
+  FunctionDecl *FD = FunctionDecl::Create(C,
+                                          C.getTranslationUnitDecl(),
+                                          SourceLocation(),
+                                          SourceLocation(), II, C.VoidTy, 0,
+                                          SC_Static,
+                                          SC_None,
+                                          false,
+                                          false);
+  
+  QualType DestTy = C.getPointerType(Ty);
+  QualType SrcTy = Ty;
+  SrcTy.addConst();
+  SrcTy = C.getPointerType(SrcTy);
+  
+  FunctionArgList args;
+  ImplicitParamDecl dstDecl(FD, SourceLocation(), 0, DestTy);
+  args.push_back(&dstDecl);
+  ImplicitParamDecl srcDecl(FD, SourceLocation(), 0, SrcTy);
+  args.push_back(&srcDecl);
+  
+  const CGFunctionInfo &FI =
+  CGM.getTypes().arrangeFunctionDeclaration(C.VoidTy, args,
+                                            FunctionType::ExtInfo(),
+                                            RequiredArgs::All);
+  
+  llvm::FunctionType *LTy = CGM.getTypes().GetFunctionType(FI);
+  
+  llvm::Function *Fn =
+  llvm::Function::Create(LTy, llvm::GlobalValue::InternalLinkage,
+                         "__copy_helper_atomic_property_", &CGM.getModule());
+  
+  if (CGM.getModuleDebugInfo())
+    DebugInfo = CGM.getModuleDebugInfo();
+  
+  
+  StartFunction(FD, C.VoidTy, Fn, FI, args, SourceLocation());
+  
+  DeclRefExpr SrcExpr(&srcDecl, false, SrcTy,
+                      VK_RValue, SourceLocation());
+  
+  UnaryOperator SRC(&SrcExpr, UO_Deref, SrcTy->getPointeeType(),
+                    VK_LValue, OK_Ordinary, SourceLocation());
+  
+  CXXConstructExpr *CXXConstExpr = 
+    cast<CXXConstructExpr>(PID->getGetterCXXConstructor());
+  
+  SmallVector<Expr*, 4> ConstructorArgs;
+  ConstructorArgs.push_back(&SRC);
+  CXXConstructExpr::arg_iterator A = CXXConstExpr->arg_begin();
+  ++A;
+  
+  for (CXXConstructExpr::arg_iterator AEnd = CXXConstExpr->arg_end();
+       A != AEnd; ++A)
+    ConstructorArgs.push_back(*A);
+  
+  CXXConstructExpr *TheCXXConstructExpr =
+    CXXConstructExpr::Create(C, Ty, SourceLocation(),
+                             CXXConstExpr->getConstructor(),
+                             CXXConstExpr->isElidable(),
+                             &ConstructorArgs[0], ConstructorArgs.size(),
+                             CXXConstExpr->hadMultipleCandidates(),
+                             CXXConstExpr->isListInitialization(),
+                             CXXConstExpr->requiresZeroInitialization(),
+                             CXXConstExpr->getConstructionKind(),
+                             SourceRange());
+  
+  DeclRefExpr DstExpr(&dstDecl, false, DestTy,
+                      VK_RValue, SourceLocation());
+  
+  RValue DV = EmitAnyExpr(&DstExpr);
+  CharUnits Alignment
+    = getContext().getTypeAlignInChars(TheCXXConstructExpr->getType());
+  EmitAggExpr(TheCXXConstructExpr, 
+              AggValueSlot::forAddr(DV.getScalarVal(), Alignment, Qualifiers(),
+                                    AggValueSlot::IsDestructed,
+                                    AggValueSlot::DoesNotNeedGCBarriers,
+                                    AggValueSlot::IsNotAliased));
+  
+  FinishFunction();
+  HelperFn = llvm::ConstantExpr::getBitCast(Fn, VoidPtrTy);
+  CGM.setAtomicGetterHelperFnMap(Ty, HelperFn);
+  return HelperFn;
+}
+
+llvm::Value *
+CodeGenFunction::EmitBlockCopyAndAutorelease(llvm::Value *Block, QualType Ty) {
+  // Get selectors for retain/autorelease.
+  IdentifierInfo *CopyID = &getContext().Idents.get("copy");
+  Selector CopySelector =
+      getContext().Selectors.getNullarySelector(CopyID);
+  IdentifierInfo *AutoreleaseID = &getContext().Idents.get("autorelease");
+  Selector AutoreleaseSelector =
+      getContext().Selectors.getNullarySelector(AutoreleaseID);
+
+  // Emit calls to retain/autorelease.
+  CGObjCRuntime &Runtime = CGM.getObjCRuntime();
+  llvm::Value *Val = Block;
+  RValue Result;
+  Result = Runtime.GenerateMessageSend(*this, ReturnValueSlot(),
+                                       Ty, CopySelector,
+                                       Val, CallArgList(), 0, 0);
+  Val = Result.getScalarVal();
+  Result = Runtime.GenerateMessageSend(*this, ReturnValueSlot(),
+                                       Ty, AutoreleaseSelector,
+                                       Val, CallArgList(), 0, 0);
+  Val = Result.getScalarVal();
+  return Val;
+}
+
+
+CGObjCRuntime::~CGObjCRuntime() {}