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

1 files changed, 3049 insertions, 0 deletions

diff --git a/clang/lib/Sema/SemaExprObjC.cpp b/clang/lib/Sema/SemaExprObjC.cpp
new file mode 100644
index 0000000..b62d56e
--- /dev/null
+++ b/clang/lib/Sema/SemaExprObjC.cpp
@@ -0,0 +1,3049 @@
+//===--- SemaExprObjC.cpp - Semantic Analysis for ObjC Expressions --------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+//  This file implements semantic analysis for Objective-C expressions.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Sema/SemaInternal.h"
+#include "clang/Sema/Lookup.h"
+#include "clang/Sema/Scope.h"
+#include "clang/Sema/ScopeInfo.h"
+#include "clang/Sema/Initialization.h"
+#include "clang/Analysis/DomainSpecific/CocoaConventions.h"
+#include "clang/Edit/Rewriters.h"
+#include "clang/Edit/Commit.h"
+#include "clang/AST/ASTContext.h"
+#include "clang/AST/DeclObjC.h"
+#include "clang/AST/ExprObjC.h"
+#include "clang/AST/StmtVisitor.h"
+#include "clang/AST/TypeLoc.h"
+#include "llvm/ADT/SmallString.h"
+#include "clang/Lex/Preprocessor.h"
+
+using namespace clang;
+using namespace sema;
+using llvm::makeArrayRef;
+
+ExprResult Sema::ParseObjCStringLiteral(SourceLocation *AtLocs,
+                                        Expr **strings,
+                                        unsigned NumStrings) {
+  StringLiteral **Strings = reinterpret_cast<StringLiteral**>(strings);
+
+  // Most ObjC strings are formed out of a single piece.  However, we *can*
+  // have strings formed out of multiple @ strings with multiple pptokens in
+  // each one, e.g. @"foo" "bar" @"baz" "qux"   which need to be turned into one
+  // StringLiteral for ObjCStringLiteral to hold onto.
+  StringLiteral *S = Strings[0];
+
+  // If we have a multi-part string, merge it all together.
+  if (NumStrings != 1) {
+    // Concatenate objc strings.
+    SmallString<128> StrBuf;
+    SmallVector<SourceLocation, 8> StrLocs;
+
+    for (unsigned i = 0; i != NumStrings; ++i) {
+      S = Strings[i];
+
+      // ObjC strings can't be wide or UTF.
+      if (!S->isAscii()) {
+        Diag(S->getLocStart(), diag::err_cfstring_literal_not_string_constant)
+          << S->getSourceRange();
+        return true;
+      }
+
+      // Append the string.
+      StrBuf += S->getString();
+
+      // Get the locations of the string tokens.
+      StrLocs.append(S->tokloc_begin(), S->tokloc_end());
+    }
+
+    // Create the aggregate string with the appropriate content and location
+    // information.
+    S = StringLiteral::Create(Context, StrBuf,
+                              StringLiteral::Ascii, /*Pascal=*/false,
+                              Context.getPointerType(Context.CharTy),
+                              &StrLocs[0], StrLocs.size());
+  }
+  
+  return BuildObjCStringLiteral(AtLocs[0], S);
+}
+
+ExprResult Sema::BuildObjCStringLiteral(SourceLocation AtLoc, StringLiteral *S){
+  // Verify that this composite string is acceptable for ObjC strings.
+  if (CheckObjCString(S))
+    return true;
+
+  // Initialize the constant string interface lazily. This assumes
+  // the NSString interface is seen in this translation unit. Note: We
+  // don't use NSConstantString, since the runtime team considers this
+  // interface private (even though it appears in the header files).
+  QualType Ty = Context.getObjCConstantStringInterface();
+  if (!Ty.isNull()) {
+    Ty = Context.getObjCObjectPointerType(Ty);
+  } else if (getLangOpts().NoConstantCFStrings) {
+    IdentifierInfo *NSIdent=0;
+    std::string StringClass(getLangOpts().ObjCConstantStringClass);
+    
+    if (StringClass.empty())
+      NSIdent = &Context.Idents.get("NSConstantString");
+    else
+      NSIdent = &Context.Idents.get(StringClass);
+    
+    NamedDecl *IF = LookupSingleName(TUScope, NSIdent, AtLoc,
+                                     LookupOrdinaryName);
+    if (ObjCInterfaceDecl *StrIF = dyn_cast_or_null<ObjCInterfaceDecl>(IF)) {
+      Context.setObjCConstantStringInterface(StrIF);
+      Ty = Context.getObjCConstantStringInterface();
+      Ty = Context.getObjCObjectPointerType(Ty);
+    } else {
+      // If there is no NSConstantString interface defined then treat this
+      // as error and recover from it.
+      Diag(S->getLocStart(), diag::err_no_nsconstant_string_class) << NSIdent
+        << S->getSourceRange();
+      Ty = Context.getObjCIdType();
+    }
+  } else {
+    IdentifierInfo *NSIdent = &Context.Idents.get("NSString");
+    NamedDecl *IF = LookupSingleName(TUScope, NSIdent, AtLoc,
+                                     LookupOrdinaryName);
+    if (ObjCInterfaceDecl *StrIF = dyn_cast_or_null<ObjCInterfaceDecl>(IF)) {
+      Context.setObjCConstantStringInterface(StrIF);
+      Ty = Context.getObjCConstantStringInterface();
+      Ty = Context.getObjCObjectPointerType(Ty);
+    } else {
+      // If there is no NSString interface defined, implicitly declare
+      // a @class NSString; and use that instead. This is to make sure
+      // type of an NSString literal is represented correctly, instead of
+      // being an 'id' type.
+      Ty = Context.getObjCNSStringType();
+      if (Ty.isNull()) {
+        ObjCInterfaceDecl *NSStringIDecl = 
+          ObjCInterfaceDecl::Create (Context, 
+                                     Context.getTranslationUnitDecl(), 
+                                     SourceLocation(), NSIdent, 
+                                     0, SourceLocation());
+        Ty = Context.getObjCInterfaceType(NSStringIDecl);
+        Context.setObjCNSStringType(Ty);
+      }
+      Ty = Context.getObjCObjectPointerType(Ty);
+    }
+  }
+
+  return new (Context) ObjCStringLiteral(S, Ty, AtLoc);
+}
+
+/// \brief Retrieve the NSNumber factory method that should be used to create
+/// an Objective-C literal for the given type.
+static ObjCMethodDecl *getNSNumberFactoryMethod(Sema &S, SourceLocation Loc,
+                                                QualType T, QualType ReturnType,
+                                                SourceRange Range) {
+  llvm::Optional<NSAPI::NSNumberLiteralMethodKind> Kind 
+    = S.NSAPIObj->getNSNumberFactoryMethodKind(T);
+  
+  if (!Kind) {
+    S.Diag(Loc, diag::err_invalid_nsnumber_type)
+      << T << Range;
+    return 0;
+  }
+    
+  // If we already looked up this method, we're done.
+  if (S.NSNumberLiteralMethods[*Kind])
+    return S.NSNumberLiteralMethods[*Kind];
+  
+  Selector Sel = S.NSAPIObj->getNSNumberLiteralSelector(*Kind,
+                                                        /*Instance=*/false);
+  
+  // Look for the appropriate method within NSNumber.
+  ObjCMethodDecl *Method = S.NSNumberDecl->lookupClassMethod(Sel);;
+  if (!Method && S.getLangOpts().DebuggerObjCLiteral) {
+    TypeSourceInfo *ResultTInfo = 0;
+    Method = ObjCMethodDecl::Create(S.Context, SourceLocation(), SourceLocation(), Sel,
+                           ReturnType,
+                           ResultTInfo,
+                           S.Context.getTranslationUnitDecl(),
+                           false /*Instance*/, false/*isVariadic*/,
+                           /*isSynthesized=*/false,
+                           /*isImplicitlyDeclared=*/true, /*isDefined=*/false,
+                           ObjCMethodDecl::Required,
+                           false);
+    ParmVarDecl *value = ParmVarDecl::Create(S.Context, Method,
+                                             SourceLocation(), SourceLocation(),
+                                             &S.Context.Idents.get("value"),
+                                             T, /*TInfo=*/0, SC_None, SC_None, 0);
+    Method->setMethodParams(S.Context, value, ArrayRef<SourceLocation>());
+  }
+
+  if (!Method) {
+    S.Diag(Loc, diag::err_undeclared_nsnumber_method) << Sel;
+    return 0;
+  }
+  
+  // Make sure the return type is reasonable.
+  if (!Method->getResultType()->isObjCObjectPointerType()) {
+    S.Diag(Loc, diag::err_objc_literal_method_sig)
+      << Sel;
+    S.Diag(Method->getLocation(), diag::note_objc_literal_method_return)
+      << Method->getResultType();
+    return 0;
+  }
+
+  // Note: if the parameter type is out-of-line, we'll catch it later in the
+  // implicit conversion.
+  
+  S.NSNumberLiteralMethods[*Kind] = Method;
+  return Method;
+}
+
+/// BuildObjCNumericLiteral - builds an ObjCNumericLiteral AST node for the
+/// numeric literal expression. Type of the expression will be "NSNumber *"
+/// or "id" if NSNumber is unavailable.
+ExprResult Sema::BuildObjCNumericLiteral(SourceLocation AtLoc, Expr *Number) {
+  // Look up the NSNumber class, if we haven't done so already.
+  if (!NSNumberDecl) {
+    NamedDecl *IF = LookupSingleName(TUScope,
+                                NSAPIObj->getNSClassId(NSAPI::ClassId_NSNumber),
+                                AtLoc, LookupOrdinaryName);
+    NSNumberDecl = dyn_cast_or_null<ObjCInterfaceDecl>(IF);
+    
+    if (!NSNumberDecl && getLangOpts().DebuggerObjCLiteral)
+      NSNumberDecl =  ObjCInterfaceDecl::Create (Context,
+                        Context.getTranslationUnitDecl(),
+                        SourceLocation(), 
+                        NSAPIObj->getNSClassId(NSAPI::ClassId_NSNumber),
+                        0, SourceLocation());
+    if (!NSNumberDecl) {
+      Diag(AtLoc, diag::err_undeclared_nsnumber);
+      return ExprError();
+    }
+  }
+  
+  // Determine the type of the literal.
+  QualType NumberType = Number->getType();
+  if (CharacterLiteral *Char = dyn_cast<CharacterLiteral>(Number)) {
+    // In C, character literals have type 'int'. That's not the type we want
+    // to use to determine the Objective-c literal kind.
+    switch (Char->getKind()) {
+    case CharacterLiteral::Ascii:
+      NumberType = Context.CharTy;
+      break;
+      
+    case CharacterLiteral::Wide:
+      NumberType = Context.getWCharType();
+      break;
+      
+    case CharacterLiteral::UTF16:
+      NumberType = Context.Char16Ty;
+      break;
+      
+    case CharacterLiteral::UTF32:
+      NumberType = Context.Char32Ty;
+      break;
+    }
+  }
+  
+  ObjCMethodDecl *Method = 0;
+  // Look for the appropriate method within NSNumber.
+  // Construct the literal.
+  QualType Ty
+    = Context.getObjCObjectPointerType(
+                                    Context.getObjCInterfaceType(NSNumberDecl));
+  Method  = getNSNumberFactoryMethod(*this, AtLoc, 
+                                     NumberType, Ty, 
+                                     Number->getSourceRange());
+
+  if (!Method)
+    return ExprError();
+
+  // Convert the number to the type that the parameter expects.
+  QualType ElementT = Method->param_begin()[0]->getType();
+  ExprResult ConvertedNumber = PerformImplicitConversion(Number, ElementT,
+                                                         AA_Sending);
+  if (ConvertedNumber.isInvalid())
+    return ExprError();
+  Number = ConvertedNumber.get();
+  
+  return MaybeBindToTemporary(
+           new (Context) ObjCNumericLiteral(Number, Ty, Method, AtLoc));
+}
+
+ExprResult Sema::ActOnObjCBoolLiteral(SourceLocation AtLoc, 
+                                      SourceLocation ValueLoc,
+                                      bool Value) {
+  ExprResult Inner;
+  if (getLangOpts().CPlusPlus) {
+    Inner = ActOnCXXBoolLiteral(ValueLoc, Value? tok::kw_true : tok::kw_false);
+  } else {
+    // C doesn't actually have a way to represent literal values of type 
+    // _Bool. So, we'll use 0/1 and implicit cast to _Bool.
+    Inner = ActOnIntegerConstant(ValueLoc, Value? 1 : 0);
+    Inner = ImpCastExprToType(Inner.get(), Context.BoolTy, 
+                              CK_IntegralToBoolean);
+  }
+  
+  return BuildObjCNumericLiteral(AtLoc, Inner.get());
+}
+
+/// \brief Check that the given expression is a valid element of an Objective-C
+/// collection literal.
+static ExprResult CheckObjCCollectionLiteralElement(Sema &S, Expr *Element, 
+                                                    QualType T) {  
+  // If the expression is type-dependent, there's nothing for us to do.
+  if (Element->isTypeDependent())
+    return Element;
+
+  ExprResult Result = S.CheckPlaceholderExpr(Element);
+  if (Result.isInvalid())
+    return ExprError();
+  Element = Result.get();
+
+  // In C++, check for an implicit conversion to an Objective-C object pointer 
+  // type.
+  if (S.getLangOpts().CPlusPlus && Element->getType()->isRecordType()) {
+    InitializedEntity Entity
+      = InitializedEntity::InitializeParameter(S.Context, T, /*Consumed=*/false);
+    InitializationKind Kind
+      = InitializationKind::CreateCopy(Element->getLocStart(), SourceLocation());
+    InitializationSequence Seq(S, Entity, Kind, &Element, 1);
+    if (!Seq.Failed())
+      return Seq.Perform(S, Entity, Kind, MultiExprArg(S, &Element, 1));
+  }
+
+  Expr *OrigElement = Element;
+
+  // Perform lvalue-to-rvalue conversion.
+  Result = S.DefaultLvalueConversion(Element);
+  if (Result.isInvalid())
+    return ExprError();
+  Element = Result.get();  
+
+  // Make sure that we have an Objective-C pointer type or block.
+  if (!Element->getType()->isObjCObjectPointerType() &&
+      !Element->getType()->isBlockPointerType()) {
+    bool Recovered = false;
+    
+    // If this is potentially an Objective-C numeric literal, add the '@'.
+    if (isa<IntegerLiteral>(OrigElement) || 
+        isa<CharacterLiteral>(OrigElement) ||
+        isa<FloatingLiteral>(OrigElement) ||
+        isa<ObjCBoolLiteralExpr>(OrigElement) ||
+        isa<CXXBoolLiteralExpr>(OrigElement)) {
+      if (S.NSAPIObj->getNSNumberFactoryMethodKind(OrigElement->getType())) {
+        int Which = isa<CharacterLiteral>(OrigElement) ? 1
+                  : (isa<CXXBoolLiteralExpr>(OrigElement) ||
+                     isa<ObjCBoolLiteralExpr>(OrigElement)) ? 2
+                  : 3;
+        
+        S.Diag(OrigElement->getLocStart(), diag::err_box_literal_collection)
+          << Which << OrigElement->getSourceRange()
+          << FixItHint::CreateInsertion(OrigElement->getLocStart(), "@");
+        
+        Result = S.BuildObjCNumericLiteral(OrigElement->getLocStart(),
+                                           OrigElement);
+        if (Result.isInvalid())
+          return ExprError();
+        
+        Element = Result.get();
+        Recovered = true;
+      }
+    }
+    // If this is potentially an Objective-C string literal, add the '@'.
+    else if (StringLiteral *String = dyn_cast<StringLiteral>(OrigElement)) {
+      if (String->isAscii()) {
+        S.Diag(OrigElement->getLocStart(), diag::err_box_literal_collection)
+          << 0 << OrigElement->getSourceRange()
+          << FixItHint::CreateInsertion(OrigElement->getLocStart(), "@");
+
+        Result = S.BuildObjCStringLiteral(OrigElement->getLocStart(), String);
+        if (Result.isInvalid())
+          return ExprError();
+        
+        Element = Result.get();
+        Recovered = true;
+      }
+    }
+    
+    if (!Recovered) {
+      S.Diag(Element->getLocStart(), diag::err_invalid_collection_element)
+        << Element->getType();
+      return ExprError();
+    }
+  }
+  
+  // Make sure that the element has the type that the container factory 
+  // function expects. 
+  return S.PerformCopyInitialization(
+           InitializedEntity::InitializeParameter(S.Context, T, 
+                                                  /*Consumed=*/false),
+           Element->getLocStart(), Element);
+}
+
+ExprResult Sema::BuildObjCSubscriptExpression(SourceLocation RB, Expr *BaseExpr,
+                                        Expr *IndexExpr,
+                                        ObjCMethodDecl *getterMethod,
+                                        ObjCMethodDecl *setterMethod) {
+  // Feature support is for modern abi.
+  if (!LangOpts.ObjCNonFragileABI)
+    return ExprError();
+  // If the expression is type-dependent, there's nothing for us to do.
+  assert ((!BaseExpr->isTypeDependent() && !IndexExpr->isTypeDependent()) &&
+          "base or index cannot have dependent type here");
+  ExprResult Result = CheckPlaceholderExpr(IndexExpr);
+  if (Result.isInvalid())
+    return ExprError();
+  IndexExpr = Result.get();
+  
+  // Perform lvalue-to-rvalue conversion.
+  Result = DefaultLvalueConversion(BaseExpr);
+  if (Result.isInvalid())
+    return ExprError();
+  BaseExpr = Result.get();
+  return Owned(ObjCSubscriptRefExpr::Create(Context, 
+                                            BaseExpr,
+                                            IndexExpr,
+                                            Context.PseudoObjectTy,
+                                            getterMethod,
+                                            setterMethod, RB));
+  
+}
+
+ExprResult Sema::BuildObjCArrayLiteral(SourceRange SR, MultiExprArg Elements) {
+  // Look up the NSArray class, if we haven't done so already.
+  if (!NSArrayDecl) {
+    NamedDecl *IF = LookupSingleName(TUScope,
+                                 NSAPIObj->getNSClassId(NSAPI::ClassId_NSArray),
+                                 SR.getBegin(),
+                                 LookupOrdinaryName);
+    NSArrayDecl = dyn_cast_or_null<ObjCInterfaceDecl>(IF);
+    if (!NSArrayDecl && getLangOpts().DebuggerObjCLiteral)
+      NSArrayDecl =  ObjCInterfaceDecl::Create (Context,
+                            Context.getTranslationUnitDecl(),
+                            SourceLocation(),
+                            NSAPIObj->getNSClassId(NSAPI::ClassId_NSArray),
+                            0, SourceLocation());
+
+    if (!NSArrayDecl) {
+      Diag(SR.getBegin(), diag::err_undeclared_nsarray);
+      return ExprError();
+    }
+  }
+  
+  // Find the arrayWithObjects:count: method, if we haven't done so already.
+  QualType IdT = Context.getObjCIdType();
+  if (!ArrayWithObjectsMethod) {
+    Selector
+      Sel = NSAPIObj->getNSArraySelector(NSAPI::NSArr_arrayWithObjectsCount);
+    ArrayWithObjectsMethod = NSArrayDecl->lookupClassMethod(Sel);
+    if (!ArrayWithObjectsMethod && getLangOpts().DebuggerObjCLiteral) {
+      TypeSourceInfo *ResultTInfo = 0;
+      ArrayWithObjectsMethod =
+                         ObjCMethodDecl::Create(Context,
+                           SourceLocation(), SourceLocation(), Sel,
+                           IdT,
+                           ResultTInfo,
+                           Context.getTranslationUnitDecl(),
+                           false /*Instance*/, false/*isVariadic*/,
+                           /*isSynthesized=*/false,
+                           /*isImplicitlyDeclared=*/true, /*isDefined=*/false,
+                           ObjCMethodDecl::Required,
+                           false);
+      SmallVector<ParmVarDecl *, 2> Params;
+      ParmVarDecl *objects = ParmVarDecl::Create(Context, ArrayWithObjectsMethod,
+                                                SourceLocation(), SourceLocation(),
+                                                &Context.Idents.get("objects"),
+                                                Context.getPointerType(IdT),
+                                                /*TInfo=*/0,
+                                                SC_None,
+                                                SC_None,
+                                                0);
+      Params.push_back(objects);
+      ParmVarDecl *cnt = ParmVarDecl::Create(Context, ArrayWithObjectsMethod,
+                                                SourceLocation(), SourceLocation(),
+                                                &Context.Idents.get("cnt"),
+                                                Context.UnsignedLongTy,
+                                                /*TInfo=*/0,
+                                                SC_None,
+                                                SC_None,
+                                                0);
+      Params.push_back(cnt);
+      ArrayWithObjectsMethod->setMethodParams(Context, Params,
+                                              ArrayRef<SourceLocation>());
+
+
+    }
+
+    if (!ArrayWithObjectsMethod) {
+      Diag(SR.getBegin(), diag::err_undeclared_arraywithobjects) << Sel;
+      return ExprError();
+    }
+  }
+  
+  // Make sure the return type is reasonable.
+  if (!ArrayWithObjectsMethod->getResultType()->isObjCObjectPointerType()) {
+    Diag(SR.getBegin(), diag::err_objc_literal_method_sig)
+      << ArrayWithObjectsMethod->getSelector();
+    Diag(ArrayWithObjectsMethod->getLocation(),
+         diag::note_objc_literal_method_return)
+      << ArrayWithObjectsMethod->getResultType();
+    return ExprError();
+  }
+
+  // Dig out the type that all elements should be converted to.
+  QualType T = ArrayWithObjectsMethod->param_begin()[0]->getType();
+  const PointerType *PtrT = T->getAs<PointerType>();
+  if (!PtrT || 
+      !Context.hasSameUnqualifiedType(PtrT->getPointeeType(), IdT)) {
+    Diag(SR.getBegin(), diag::err_objc_literal_method_sig)
+      << ArrayWithObjectsMethod->getSelector();
+    Diag(ArrayWithObjectsMethod->param_begin()[0]->getLocation(),
+         diag::note_objc_literal_method_param)
+      << 0 << T 
+      << Context.getPointerType(IdT.withConst());
+    return ExprError();
+  }
+  T = PtrT->getPointeeType();
+  
+  // Check that the 'count' parameter is integral.
+  if (!ArrayWithObjectsMethod->param_begin()[1]->getType()->isIntegerType()) {
+    Diag(SR.getBegin(), diag::err_objc_literal_method_sig)
+      << ArrayWithObjectsMethod->getSelector();
+    Diag(ArrayWithObjectsMethod->param_begin()[1]->getLocation(),
+         diag::note_objc_literal_method_param)
+      << 1 
+      << ArrayWithObjectsMethod->param_begin()[1]->getType()
+      << "integral";
+    return ExprError();
+  }
+
+  // Check that each of the elements provided is valid in a collection literal,
+  // performing conversions as necessary.
+  Expr **ElementsBuffer = Elements.get();
+  for (unsigned I = 0, N = Elements.size(); I != N; ++I) {
+    ExprResult Converted = CheckObjCCollectionLiteralElement(*this,
+                                                             ElementsBuffer[I],
+                                                             T);
+    if (Converted.isInvalid())
+      return ExprError();
+    
+    ElementsBuffer[I] = Converted.get();
+  }
+    
+  QualType Ty 
+    = Context.getObjCObjectPointerType(
+                                    Context.getObjCInterfaceType(NSArrayDecl));
+
+  return MaybeBindToTemporary(
+           ObjCArrayLiteral::Create(Context, 
+                                    llvm::makeArrayRef(Elements.get(), 
+                                                       Elements.size()), 
+                                    Ty, ArrayWithObjectsMethod, SR));
+}
+
+ExprResult Sema::BuildObjCDictionaryLiteral(SourceRange SR, 
+                                            ObjCDictionaryElement *Elements,
+                                            unsigned NumElements) {
+  // Look up the NSDictionary class, if we haven't done so already.
+  if (!NSDictionaryDecl) {
+    NamedDecl *IF = LookupSingleName(TUScope,
+                            NSAPIObj->getNSClassId(NSAPI::ClassId_NSDictionary),
+                            SR.getBegin(), LookupOrdinaryName);
+    NSDictionaryDecl = dyn_cast_or_null<ObjCInterfaceDecl>(IF);
+    if (!NSDictionaryDecl && getLangOpts().DebuggerObjCLiteral)
+      NSDictionaryDecl =  ObjCInterfaceDecl::Create (Context,
+                            Context.getTranslationUnitDecl(),
+                            SourceLocation(),
+                            NSAPIObj->getNSClassId(NSAPI::ClassId_NSDictionary),
+                            0, SourceLocation());
+
+    if (!NSDictionaryDecl) {
+      Diag(SR.getBegin(), diag::err_undeclared_nsdictionary);
+      return ExprError();    
+    }
+  }
+  
+  // Find the dictionaryWithObjects:forKeys:count: method, if we haven't done
+  // so already.
+  QualType IdT = Context.getObjCIdType();
+  if (!DictionaryWithObjectsMethod) {
+    Selector Sel = NSAPIObj->getNSDictionarySelector(
+                                    NSAPI::NSDict_dictionaryWithObjectsForKeysCount);
+    DictionaryWithObjectsMethod = NSDictionaryDecl->lookupClassMethod(Sel);
+    if (!DictionaryWithObjectsMethod && getLangOpts().DebuggerObjCLiteral) {
+      DictionaryWithObjectsMethod = 
+                         ObjCMethodDecl::Create(Context,  
+                           SourceLocation(), SourceLocation(), Sel,
+                           IdT,
+                           0 /*TypeSourceInfo */,
+                           Context.getTranslationUnitDecl(),
+                           false /*Instance*/, false/*isVariadic*/,
+                           /*isSynthesized=*/false,
+                           /*isImplicitlyDeclared=*/true, /*isDefined=*/false,
+                           ObjCMethodDecl::Required,
+                           false);
+      SmallVector<ParmVarDecl *, 3> Params;
+      ParmVarDecl *objects = ParmVarDecl::Create(Context, DictionaryWithObjectsMethod,
+                                                SourceLocation(), SourceLocation(),
+                                                &Context.Idents.get("objects"),
+                                                Context.getPointerType(IdT),
+                                                /*TInfo=*/0,
+                                                SC_None,
+                                                SC_None,
+                                                0);
+      Params.push_back(objects);
+      ParmVarDecl *keys = ParmVarDecl::Create(Context, DictionaryWithObjectsMethod,
+                                                SourceLocation(), SourceLocation(),
+                                                &Context.Idents.get("keys"),
+                                                Context.getPointerType(IdT),
+                                                /*TInfo=*/0,
+                                                SC_None,
+                                                SC_None,
+                                                0);
+      Params.push_back(keys);
+      ParmVarDecl *cnt = ParmVarDecl::Create(Context, DictionaryWithObjectsMethod,
+                                                SourceLocation(), SourceLocation(),
+                                                &Context.Idents.get("cnt"),
+                                                Context.UnsignedLongTy,
+                                                /*TInfo=*/0,
+                                                SC_None,
+                                                SC_None,
+                                                0);
+      Params.push_back(cnt);
+      DictionaryWithObjectsMethod->setMethodParams(Context, Params, 
+                                                   ArrayRef<SourceLocation>());
+    }
+
+    if (!DictionaryWithObjectsMethod) {
+      Diag(SR.getBegin(), diag::err_undeclared_dictwithobjects) << Sel;
+      return ExprError();    
+    }
+  }
+  
+  // Make sure the return type is reasonable.
+  if (!DictionaryWithObjectsMethod->getResultType()->isObjCObjectPointerType()){
+    Diag(SR.getBegin(), diag::err_objc_literal_method_sig)
+    << DictionaryWithObjectsMethod->getSelector();
+    Diag(DictionaryWithObjectsMethod->getLocation(),
+         diag::note_objc_literal_method_return)
+    << DictionaryWithObjectsMethod->getResultType();
+    return ExprError();
+  }
+
+  // Dig out the type that all values should be converted to.
+  QualType ValueT =  DictionaryWithObjectsMethod->param_begin()[0]->getType();
+  const PointerType *PtrValue = ValueT->getAs<PointerType>();
+  if (!PtrValue || 
+      !Context.hasSameUnqualifiedType(PtrValue->getPointeeType(), IdT)) {
+    Diag(SR.getBegin(), diag::err_objc_literal_method_sig)
+      << DictionaryWithObjectsMethod->getSelector();
+    Diag(DictionaryWithObjectsMethod->param_begin()[0]->getLocation(),
+         diag::note_objc_literal_method_param)
+      << 0 << ValueT
+      << Context.getPointerType(IdT.withConst());
+    return ExprError();
+  }
+  ValueT = PtrValue->getPointeeType();
+
+  // Dig out the type that all keys should be converted to.
+  QualType KeyT = DictionaryWithObjectsMethod->param_begin()[1]->getType();
+  const PointerType *PtrKey = KeyT->getAs<PointerType>();
+  if (!PtrKey || 
+      !Context.hasSameUnqualifiedType(PtrKey->getPointeeType(),
+                                      IdT)) {
+    bool err = true;
+    if (PtrKey) {
+      if (QIDNSCopying.isNull()) {
+        // key argument of selector is id<NSCopying>?
+        if (ObjCProtocolDecl *NSCopyingPDecl =
+            LookupProtocol(&Context.Idents.get("NSCopying"), SR.getBegin())) {
+          ObjCProtocolDecl *PQ[] = {NSCopyingPDecl};
+          QIDNSCopying = 
+            Context.getObjCObjectType(Context.ObjCBuiltinIdTy,
+                                      (ObjCProtocolDecl**) PQ,1);
+          QIDNSCopying = Context.getObjCObjectPointerType(QIDNSCopying);
+        }
+      }
+      if (!QIDNSCopying.isNull())
+        err = !Context.hasSameUnqualifiedType(PtrKey->getPointeeType(),
+                                              QIDNSCopying);
+    }
+    
+    if (err) {
+      Diag(SR.getBegin(), diag::err_objc_literal_method_sig)
+        << DictionaryWithObjectsMethod->getSelector();
+      Diag(DictionaryWithObjectsMethod->param_begin()[1]->getLocation(),
+           diag::note_objc_literal_method_param)
+        << 1 << KeyT
+        << Context.getPointerType(IdT.withConst());
+      return ExprError();
+    }
+  }
+  KeyT = PtrKey->getPointeeType();
+
+  // Check that the 'count' parameter is integral.
+  if (!DictionaryWithObjectsMethod->param_begin()[2]->getType()
+                                                            ->isIntegerType()) {
+    Diag(SR.getBegin(), diag::err_objc_literal_method_sig)
+      << DictionaryWithObjectsMethod->getSelector();
+    Diag(DictionaryWithObjectsMethod->param_begin()[2]->getLocation(),
+         diag::note_objc_literal_method_param)
+      << 2
+      << DictionaryWithObjectsMethod->param_begin()[2]->getType()
+      << "integral";
+    return ExprError();
+  }
+
+  // Check that each of the keys and values provided is valid in a collection 
+  // literal, performing conversions as necessary.
+  bool HasPackExpansions = false;
+  for (unsigned I = 0, N = NumElements; I != N; ++I) {
+    // Check the key.
+    ExprResult Key = CheckObjCCollectionLiteralElement(*this, Elements[I].Key, 
+                                                       KeyT);
+    if (Key.isInvalid())
+      return ExprError();
+    
+    // Check the value.
+    ExprResult Value
+      = CheckObjCCollectionLiteralElement(*this, Elements[I].Value, ValueT);
+    if (Value.isInvalid())
+      return ExprError();
+    
+    Elements[I].Key = Key.get();
+    Elements[I].Value = Value.get();
+    
+    if (Elements[I].EllipsisLoc.isInvalid())
+      continue;
+    
+    if (!Elements[I].Key->containsUnexpandedParameterPack() &&
+        !Elements[I].Value->containsUnexpandedParameterPack()) {
+      Diag(Elements[I].EllipsisLoc, 
+           diag::err_pack_expansion_without_parameter_packs)
+        << SourceRange(Elements[I].Key->getLocStart(),
+                       Elements[I].Value->getLocEnd());
+      return ExprError();
+    }
+    
+    HasPackExpansions = true;
+  }
+
+  
+  QualType Ty
+    = Context.getObjCObjectPointerType(
+                                Context.getObjCInterfaceType(NSDictionaryDecl));  
+  return MaybeBindToTemporary(
+           ObjCDictionaryLiteral::Create(Context, 
+                                         llvm::makeArrayRef(Elements, 
+                                                            NumElements),
+                                         HasPackExpansions,
+                                         Ty, 
+                                         DictionaryWithObjectsMethod, SR));
+}
+
+ExprResult Sema::BuildObjCEncodeExpression(SourceLocation AtLoc,
+                                      TypeSourceInfo *EncodedTypeInfo,
+                                      SourceLocation RParenLoc) {
+  QualType EncodedType = EncodedTypeInfo->getType();
+  QualType StrTy;
+  if (EncodedType->isDependentType())
+    StrTy = Context.DependentTy;
+  else {
+    if (!EncodedType->getAsArrayTypeUnsafe() && //// Incomplete array is handled.
+        !EncodedType->isVoidType()) // void is handled too.
+      if (RequireCompleteType(AtLoc, EncodedType,
+                         PDiag(diag::err_incomplete_type_objc_at_encode)
+                             << EncodedTypeInfo->getTypeLoc().getSourceRange()))
+        return ExprError();
+
+    std::string Str;
+    Context.getObjCEncodingForType(EncodedType, Str);
+
+    // The type of @encode is the same as the type of the corresponding string,
+    // which is an array type.
+    StrTy = Context.CharTy;
+    // A C++ string literal has a const-qualified element type (C++ 2.13.4p1).
+    if (getLangOpts().CPlusPlus || getLangOpts().ConstStrings)
+      StrTy.addConst();
+    StrTy = Context.getConstantArrayType(StrTy, llvm::APInt(32, Str.size()+1),
+                                         ArrayType::Normal, 0);
+  }
+
+  return new (Context) ObjCEncodeExpr(StrTy, EncodedTypeInfo, AtLoc, RParenLoc);
+}
+
+ExprResult Sema::ParseObjCEncodeExpression(SourceLocation AtLoc,
+                                           SourceLocation EncodeLoc,
+                                           SourceLocation LParenLoc,
+                                           ParsedType ty,
+                                           SourceLocation RParenLoc) {
+  // FIXME: Preserve type source info ?
+  TypeSourceInfo *TInfo;
+  QualType EncodedType = GetTypeFromParser(ty, &TInfo);
+  if (!TInfo)
+    TInfo = Context.getTrivialTypeSourceInfo(EncodedType,
+                                             PP.getLocForEndOfToken(LParenLoc));
+
+  return BuildObjCEncodeExpression(AtLoc, TInfo, RParenLoc);
+}
+
+ExprResult Sema::ParseObjCSelectorExpression(Selector Sel,
+                                             SourceLocation AtLoc,
+                                             SourceLocation SelLoc,
+                                             SourceLocation LParenLoc,
+                                             SourceLocation RParenLoc) {
+  ObjCMethodDecl *Method = LookupInstanceMethodInGlobalPool(Sel,
+                             SourceRange(LParenLoc, RParenLoc), false, false);
+  if (!Method)
+    Method = LookupFactoryMethodInGlobalPool(Sel,
+                                          SourceRange(LParenLoc, RParenLoc));
+  if (!Method)
+    Diag(SelLoc, diag::warn_undeclared_selector) << Sel;
+  
+  if (!Method ||
+      Method->getImplementationControl() != ObjCMethodDecl::Optional) {
+    llvm::DenseMap<Selector, SourceLocation>::iterator Pos
+      = ReferencedSelectors.find(Sel);
+    if (Pos == ReferencedSelectors.end())
+      ReferencedSelectors.insert(std::make_pair(Sel, SelLoc));
+  }
+
+  // In ARC, forbid the user from using @selector for 
+  // retain/release/autorelease/dealloc/retainCount.
+  if (getLangOpts().ObjCAutoRefCount) {
+    switch (Sel.getMethodFamily()) {
+    case OMF_retain:
+    case OMF_release:
+    case OMF_autorelease:
+    case OMF_retainCount:
+    case OMF_dealloc:
+      Diag(AtLoc, diag::err_arc_illegal_selector) << 
+        Sel << SourceRange(LParenLoc, RParenLoc);
+      break;
+
+    case OMF_None:
+    case OMF_alloc:
+    case OMF_copy:
+    case OMF_finalize:
+    case OMF_init:
+    case OMF_mutableCopy:
+    case OMF_new:
+    case OMF_self:
+    case OMF_performSelector:
+      break;
+    }
+  }
+  QualType Ty = Context.getObjCSelType();
+  return new (Context) ObjCSelectorExpr(Ty, Sel, AtLoc, RParenLoc);
+}
+
+ExprResult Sema::ParseObjCProtocolExpression(IdentifierInfo *ProtocolId,
+                                             SourceLocation AtLoc,
+                                             SourceLocation ProtoLoc,
+                                             SourceLocation LParenLoc,
+                                             SourceLocation RParenLoc) {
+  ObjCProtocolDecl* PDecl = LookupProtocol(ProtocolId, ProtoLoc);
+  if (!PDecl) {
+    Diag(ProtoLoc, diag::err_undeclared_protocol) << ProtocolId;
+    return true;
+  }
+
+  QualType Ty = Context.getObjCProtoType();
+  if (Ty.isNull())
+    return true;
+  Ty = Context.getObjCObjectPointerType(Ty);
+  return new (Context) ObjCProtocolExpr(Ty, PDecl, AtLoc, RParenLoc);
+}
+
+/// Try to capture an implicit reference to 'self'.
+ObjCMethodDecl *Sema::tryCaptureObjCSelf(SourceLocation Loc) {
+  DeclContext *DC = getFunctionLevelDeclContext();
+
+  // If we're not in an ObjC method, error out.  Note that, unlike the
+  // C++ case, we don't require an instance method --- class methods
+  // still have a 'self', and we really do still need to capture it!
+  ObjCMethodDecl *method = dyn_cast<ObjCMethodDecl>(DC);
+  if (!method)
+    return 0;
+
+  tryCaptureVariable(method->getSelfDecl(), Loc);
+
+  return method;
+}
+
+static QualType stripObjCInstanceType(ASTContext &Context, QualType T) {
+  if (T == Context.getObjCInstanceType())
+    return Context.getObjCIdType();
+  
+  return T;
+}
+
+QualType Sema::getMessageSendResultType(QualType ReceiverType,
+                                        ObjCMethodDecl *Method,
+                                    bool isClassMessage, bool isSuperMessage) {
+  assert(Method && "Must have a method");
+  if (!Method->hasRelatedResultType())
+    return Method->getSendResultType();
+  
+  // If a method has a related return type:
+  //   - if the method found is an instance method, but the message send
+  //     was a class message send, T is the declared return type of the method
+  //     found
+  if (Method->isInstanceMethod() && isClassMessage)
+    return stripObjCInstanceType(Context, Method->getSendResultType());
+  
+  //   - if the receiver is super, T is a pointer to the class of the 
+  //     enclosing method definition
+  if (isSuperMessage) {
+    if (ObjCMethodDecl *CurMethod = getCurMethodDecl())
+      if (ObjCInterfaceDecl *Class = CurMethod->getClassInterface())
+        return Context.getObjCObjectPointerType(
+                                        Context.getObjCInterfaceType(Class));
+  }
+    
+  //   - if the receiver is the name of a class U, T is a pointer to U
+  if (ReceiverType->getAs<ObjCInterfaceType>() ||
+      ReceiverType->isObjCQualifiedInterfaceType())
+    return Context.getObjCObjectPointerType(ReceiverType);
+  //   - if the receiver is of type Class or qualified Class type, 
+  //     T is the declared return type of the method.
+  if (ReceiverType->isObjCClassType() ||
+      ReceiverType->isObjCQualifiedClassType())
+    return stripObjCInstanceType(Context, Method->getSendResultType());
+  
+  //   - if the receiver is id, qualified id, Class, or qualified Class, T
+  //     is the receiver type, otherwise
+  //   - T is the type of the receiver expression.
+  return ReceiverType;
+}
+
+void Sema::EmitRelatedResultTypeNote(const Expr *E) {
+  E = E->IgnoreParenImpCasts();
+  const ObjCMessageExpr *MsgSend = dyn_cast<ObjCMessageExpr>(E);
+  if (!MsgSend)
+    return;
+  
+  const ObjCMethodDecl *Method = MsgSend->getMethodDecl();
+  if (!Method)
+    return;
+  
+  if (!Method->hasRelatedResultType())
+    return;
+  
+  if (Context.hasSameUnqualifiedType(Method->getResultType()
+                                                        .getNonReferenceType(),
+                                     MsgSend->getType()))
+    return;
+  
+  if (!Context.hasSameUnqualifiedType(Method->getResultType(), 
+                                      Context.getObjCInstanceType()))
+    return;
+  
+  Diag(Method->getLocation(), diag::note_related_result_type_inferred)
+    << Method->isInstanceMethod() << Method->getSelector()
+    << MsgSend->getType();
+}
+
+bool Sema::CheckMessageArgumentTypes(QualType ReceiverType,
+                                     Expr **Args, unsigned NumArgs,
+                                     Selector Sel, ObjCMethodDecl *Method,
+                                     bool isClassMessage, bool isSuperMessage,
+                                     SourceLocation lbrac, SourceLocation rbrac,
+                                     QualType &ReturnType, ExprValueKind &VK) {
+  if (!Method) {
+    // Apply default argument promotion as for (C99 6.5.2.2p6).
+    for (unsigned i = 0; i != NumArgs; i++) {
+      if (Args[i]->isTypeDependent())
+        continue;
+
+      ExprResult Result = DefaultArgumentPromotion(Args[i]);
+      if (Result.isInvalid())
+        return true;
+      Args[i] = Result.take();
+    }
+
+    unsigned DiagID;
+    if (getLangOpts().ObjCAutoRefCount)
+      DiagID = diag::err_arc_method_not_found;
+    else
+      DiagID = isClassMessage ? diag::warn_class_method_not_found
+                              : diag::warn_inst_method_not_found;
+    if (!getLangOpts().DebuggerSupport)
+      Diag(lbrac, DiagID)
+        << Sel << isClassMessage << SourceRange(lbrac, rbrac);
+
+    // In debuggers, we want to use __unknown_anytype for these
+    // results so that clients can cast them.
+    if (getLangOpts().DebuggerSupport) {
+      ReturnType = Context.UnknownAnyTy;
+    } else {
+      ReturnType = Context.getObjCIdType();
+    }
+    VK = VK_RValue;
+    return false;
+  }
+
+  ReturnType = getMessageSendResultType(ReceiverType, Method, isClassMessage, 
+                                        isSuperMessage);
+  VK = Expr::getValueKindForType(Method->getResultType());
+
+  unsigned NumNamedArgs = Sel.getNumArgs();
+  // Method might have more arguments than selector indicates. This is due
+  // to addition of c-style arguments in method.
+  if (Method->param_size() > Sel.getNumArgs())
+    NumNamedArgs = Method->param_size();
+  // FIXME. This need be cleaned up.
+  if (NumArgs < NumNamedArgs) {
+    Diag(lbrac, diag::err_typecheck_call_too_few_args)
+      << 2 << NumNamedArgs << NumArgs;
+    return false;
+  }
+
+  bool IsError = false;
+  for (unsigned i = 0; i < NumNamedArgs; i++) {
+    // We can't do any type-checking on a type-dependent argument.
+    if (Args[i]->isTypeDependent())
+      continue;
+
+    Expr *argExpr = Args[i];
+
+    ParmVarDecl *param = Method->param_begin()[i];
+    assert(argExpr && "CheckMessageArgumentTypes(): missing expression");
+
+    // Strip the unbridged-cast placeholder expression off unless it's
+    // a consumed argument.
+    if (argExpr->hasPlaceholderType(BuiltinType::ARCUnbridgedCast) &&
+        !param->hasAttr<CFConsumedAttr>())
+      argExpr = stripARCUnbridgedCast(argExpr);
+
+    if (RequireCompleteType(argExpr->getSourceRange().getBegin(),
+                            param->getType(),
+                            PDiag(diag::err_call_incomplete_argument)
+                              << argExpr->getSourceRange()))
+      return true;
+
+    InitializedEntity Entity = InitializedEntity::InitializeParameter(Context,
+                                                                      param);
+    ExprResult ArgE = PerformCopyInitialization(Entity, lbrac, Owned(argExpr));
+    if (ArgE.isInvalid())
+      IsError = true;
+    else
+      Args[i] = ArgE.takeAs<Expr>();
+  }
+
+  // Promote additional arguments to variadic methods.
+  if (Method->isVariadic()) {
+    for (unsigned i = NumNamedArgs; i < NumArgs; ++i) {
+      if (Args[i]->isTypeDependent())
+        continue;
+
+      ExprResult Arg = DefaultVariadicArgumentPromotion(Args[i], VariadicMethod, 0);
+      IsError |= Arg.isInvalid();
+      Args[i] = Arg.take();
+    }
+  } else {
+    // Check for extra arguments to non-variadic methods.
+    if (NumArgs != NumNamedArgs) {
+      Diag(Args[NumNamedArgs]->getLocStart(),
+           diag::err_typecheck_call_too_many_args)
+        << 2 /*method*/ << NumNamedArgs << NumArgs
+        << Method->getSourceRange()
+        << SourceRange(Args[NumNamedArgs]->getLocStart(),
+                       Args[NumArgs-1]->getLocEnd());
+    }
+  }
+
+  DiagnoseSentinelCalls(Method, lbrac, Args, NumArgs);
+
+  // Do additional checkings on method.
+  IsError |= CheckObjCMethodCall(Method, lbrac, Args, NumArgs);
+
+  return IsError;
+}
+
+bool Sema::isSelfExpr(Expr *receiver) {
+  // 'self' is objc 'self' in an objc method only.
+  ObjCMethodDecl *method =
+    dyn_cast<ObjCMethodDecl>(CurContext->getNonClosureAncestor());
+  if (!method) return false;
+
+  receiver = receiver->IgnoreParenLValueCasts();
+  if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(receiver))
+    if (DRE->getDecl() == method->getSelfDecl())
+      return true;
+  return false;
+}
+
+// Helper method for ActOnClassMethod/ActOnInstanceMethod.
+// Will search "local" class/category implementations for a method decl.
+// If failed, then we search in class's root for an instance method.
+// Returns 0 if no method is found.
+ObjCMethodDecl *Sema::LookupPrivateClassMethod(Selector Sel,
+                                          ObjCInterfaceDecl *ClassDecl) {
+  ObjCMethodDecl *Method = 0;
+  // lookup in class and all superclasses
+  while (ClassDecl && !Method) {
+    if (ObjCImplementationDecl *ImpDecl = ClassDecl->getImplementation())
+      Method = ImpDecl->getClassMethod(Sel);
+
+    // Look through local category implementations associated with the class.
+    if (!Method)
+      Method = ClassDecl->getCategoryClassMethod(Sel);
+
+    // Before we give up, check if the selector is an instance method.
+    // But only in the root. This matches gcc's behaviour and what the
+    // runtime expects.
+    if (!Method && !ClassDecl->getSuperClass()) {
+      Method = ClassDecl->lookupInstanceMethod(Sel);
+      // Look through local category implementations associated
+      // with the root class.
+      if (!Method)
+        Method = LookupPrivateInstanceMethod(Sel, ClassDecl);
+    }
+
+    ClassDecl = ClassDecl->getSuperClass();
+  }
+  return Method;
+}
+
+ObjCMethodDecl *Sema::LookupPrivateInstanceMethod(Selector Sel,
+                                              ObjCInterfaceDecl *ClassDecl) {
+  if (!ClassDecl->hasDefinition())
+    return 0;
+
+  ObjCMethodDecl *Method = 0;
+  while (ClassDecl && !Method) {
+    // If we have implementations in scope, check "private" methods.
+    if (ObjCImplementationDecl *ImpDecl = ClassDecl->getImplementation())
+      Method = ImpDecl->getInstanceMethod(Sel);
+
+    // Look through local category implementations associated with the class.
+    if (!Method)
+      Method = ClassDecl->getCategoryInstanceMethod(Sel);
+    ClassDecl = ClassDecl->getSuperClass();
+  }
+  return Method;
+}
+
+/// LookupMethodInType - Look up a method in an ObjCObjectType.
+ObjCMethodDecl *Sema::LookupMethodInObjectType(Selector sel, QualType type,
+                                               bool isInstance) {
+  const ObjCObjectType *objType = type->castAs<ObjCObjectType>();
+  if (ObjCInterfaceDecl *iface = objType->getInterface()) {
+    // Look it up in the main interface (and categories, etc.)
+    if (ObjCMethodDecl *method = iface->lookupMethod(sel, isInstance))
+      return method;
+
+    // Okay, look for "private" methods declared in any
+    // @implementations we've seen.
+    if (isInstance) {
+      if (ObjCMethodDecl *method = LookupPrivateInstanceMethod(sel, iface))
+        return method;
+    } else {
+      if (ObjCMethodDecl *method = LookupPrivateClassMethod(sel, iface))
+        return method;
+    }
+  }
+
+  // Check qualifiers.
+  for (ObjCObjectType::qual_iterator
+         i = objType->qual_begin(), e = objType->qual_end(); i != e; ++i)
+    if (ObjCMethodDecl *method = (*i)->lookupMethod(sel, isInstance))
+      return method;
+
+  return 0;
+}
+
+/// LookupMethodInQualifiedType - Lookups up a method in protocol qualifier 
+/// list of a qualified objective pointer type.
+ObjCMethodDecl *Sema::LookupMethodInQualifiedType(Selector Sel,
+                                              const ObjCObjectPointerType *OPT,
+                                              bool Instance)
+{
+  ObjCMethodDecl *MD = 0;
+  for (ObjCObjectPointerType::qual_iterator I = OPT->qual_begin(),
+       E = OPT->qual_end(); I != E; ++I) {
+    ObjCProtocolDecl *PROTO = (*I);
+    if ((MD = PROTO->lookupMethod(Sel, Instance))) {
+      return MD;
+    }
+  }
+  return 0;
+}
+
+/// HandleExprPropertyRefExpr - Handle foo.bar where foo is a pointer to an
+/// objective C interface.  This is a property reference expression.
+ExprResult Sema::
+HandleExprPropertyRefExpr(const ObjCObjectPointerType *OPT,
+                          Expr *BaseExpr, SourceLocation OpLoc,
+                          DeclarationName MemberName,
+                          SourceLocation MemberLoc,
+                          SourceLocation SuperLoc, QualType SuperType,
+                          bool Super) {
+  const ObjCInterfaceType *IFaceT = OPT->getInterfaceType();
+  ObjCInterfaceDecl *IFace = IFaceT->getDecl();
+  
+  if (MemberName.getNameKind() != DeclarationName::Identifier) {
+    Diag(MemberLoc, diag::err_invalid_property_name)
+      << MemberName << QualType(OPT, 0);
+    return ExprError();
+  }
+  
+  IdentifierInfo *Member = MemberName.getAsIdentifierInfo();
+  SourceRange BaseRange = Super? SourceRange(SuperLoc)
+                               : BaseExpr->getSourceRange();
+  if (RequireCompleteType(MemberLoc, OPT->getPointeeType(), 
+                          PDiag(diag::err_property_not_found_forward_class)
+                            << MemberName << BaseRange))
+    return ExprError();
+  
+  // Search for a declared property first.
+  if (ObjCPropertyDecl *PD = IFace->FindPropertyDeclaration(Member)) {
+    // Check whether we can reference this property.
+    if (DiagnoseUseOfDecl(PD, MemberLoc))
+      return ExprError();
+             
+    if (Super)
+      return Owned(new (Context) ObjCPropertyRefExpr(PD, Context.PseudoObjectTy,
+                                                     VK_LValue, OK_ObjCProperty,
+                                                     MemberLoc, 
+                                                     SuperLoc, SuperType));
+    else
+      return Owned(new (Context) ObjCPropertyRefExpr(PD, Context.PseudoObjectTy,
+                                                     VK_LValue, OK_ObjCProperty,
+                                                     MemberLoc, BaseExpr));
+  }
+  // Check protocols on qualified interfaces.
+  for (ObjCObjectPointerType::qual_iterator I = OPT->qual_begin(),
+       E = OPT->qual_end(); I != E; ++I)
+    if (ObjCPropertyDecl *PD = (*I)->FindPropertyDeclaration(Member)) {
+      // Check whether we can reference this property.
+      if (DiagnoseUseOfDecl(PD, MemberLoc))
+        return ExprError();
+      
+      if (Super)
+        return Owned(new (Context) ObjCPropertyRefExpr(PD,
+                                                       Context.PseudoObjectTy,
+                                                       VK_LValue,
+                                                       OK_ObjCProperty,
+                                                       MemberLoc, 
+                                                       SuperLoc, SuperType));
+      else
+        return Owned(new (Context) ObjCPropertyRefExpr(PD,
+                                                       Context.PseudoObjectTy,
+                                                       VK_LValue,
+                                                       OK_ObjCProperty,
+                                                       MemberLoc,
+                                                       BaseExpr));
+    }
+  // If that failed, look for an "implicit" property by seeing if the nullary
+  // selector is implemented.
+
+  // FIXME: The logic for looking up nullary and unary selectors should be
+  // shared with the code in ActOnInstanceMessage.
+
+  Selector Sel = PP.getSelectorTable().getNullarySelector(Member);
+  ObjCMethodDecl *Getter = IFace->lookupInstanceMethod(Sel);
+  
+  // May be founf in property's qualified list.
+  if (!Getter)
+    Getter = LookupMethodInQualifiedType(Sel, OPT, true);
+
+  // If this reference is in an @implementation, check for 'private' methods.
+  if (!Getter)
+    Getter = IFace->lookupPrivateMethod(Sel);
+
+  // Look through local category implementations associated with the class.
+  if (!Getter)
+    Getter = IFace->getCategoryInstanceMethod(Sel);
+  if (Getter) {
+    // Check if we can reference this property.
+    if (DiagnoseUseOfDecl(Getter, MemberLoc))
+      return ExprError();
+  }
+  // If we found a getter then this may be a valid dot-reference, we
+  // will look for the matching setter, in case it is needed.
+  Selector SetterSel =
+    SelectorTable::constructSetterName(PP.getIdentifierTable(),
+                                       PP.getSelectorTable(), Member);
+  ObjCMethodDecl *Setter = IFace->lookupInstanceMethod(SetterSel);
+  
+  // May be founf in property's qualified list.
+  if (!Setter)
+    Setter = LookupMethodInQualifiedType(SetterSel, OPT, true);
+  
+  if (!Setter) {
+    // If this reference is in an @implementation, also check for 'private'
+    // methods.
+    Setter = IFace->lookupPrivateMethod(SetterSel);
+  }
+  // Look through local category implementations associated with the class.
+  if (!Setter)
+    Setter = IFace->getCategoryInstanceMethod(SetterSel);
+    
+  if (Setter && DiagnoseUseOfDecl(Setter, MemberLoc))
+    return ExprError();
+
+  if (Getter || Setter) {
+    if (Super)
+      return Owned(new (Context) ObjCPropertyRefExpr(Getter, Setter,
+                                                     Context.PseudoObjectTy,
+                                                     VK_LValue, OK_ObjCProperty,
+                                                     MemberLoc,
+                                                     SuperLoc, SuperType));
+    else
+      return Owned(new (Context) ObjCPropertyRefExpr(Getter, Setter,
+                                                     Context.PseudoObjectTy,
+                                                     VK_LValue, OK_ObjCProperty,
+                                                     MemberLoc, BaseExpr));
+
+  }
+
+  // Attempt to correct for typos in property names.
+  DeclFilterCCC<ObjCPropertyDecl> Validator;
+  if (TypoCorrection Corrected = CorrectTypo(
+      DeclarationNameInfo(MemberName, MemberLoc), LookupOrdinaryName, NULL,
+      NULL, Validator, IFace, false, OPT)) {
+    ObjCPropertyDecl *Property =
+        Corrected.getCorrectionDeclAs<ObjCPropertyDecl>();
+    DeclarationName TypoResult = Corrected.getCorrection();
+    Diag(MemberLoc, diag::err_property_not_found_suggest)
+      << MemberName << QualType(OPT, 0) << TypoResult
+      << FixItHint::CreateReplacement(MemberLoc, TypoResult.getAsString());
+    Diag(Property->getLocation(), diag::note_previous_decl)
+      << Property->getDeclName();
+    return HandleExprPropertyRefExpr(OPT, BaseExpr, OpLoc,
+                                     TypoResult, MemberLoc,
+                                     SuperLoc, SuperType, Super);
+  }
+  ObjCInterfaceDecl *ClassDeclared;
+  if (ObjCIvarDecl *Ivar = 
+      IFace->lookupInstanceVariable(Member, ClassDeclared)) {
+    QualType T = Ivar->getType();
+    if (const ObjCObjectPointerType * OBJPT = 
+        T->getAsObjCInterfacePointerType()) {
+      if (RequireCompleteType(MemberLoc, OBJPT->getPointeeType(), 
+                              PDiag(diag::err_property_not_as_forward_class)
+                                << MemberName << BaseExpr->getSourceRange()))
+        return ExprError();
+    }
+    Diag(MemberLoc, 
+         diag::err_ivar_access_using_property_syntax_suggest)
+    << MemberName << QualType(OPT, 0) << Ivar->getDeclName()
+    << FixItHint::CreateReplacement(OpLoc, "->");
+    return ExprError();
+  }
+  
+  Diag(MemberLoc, diag::err_property_not_found)
+    << MemberName << QualType(OPT, 0);
+  if (Setter)
+    Diag(Setter->getLocation(), diag::note_getter_unavailable)
+          << MemberName << BaseExpr->getSourceRange();
+  return ExprError();
+}
+
+
+
+ExprResult Sema::
+ActOnClassPropertyRefExpr(IdentifierInfo &receiverName,
+                          IdentifierInfo &propertyName,
+                          SourceLocation receiverNameLoc,
+                          SourceLocation propertyNameLoc) {
+
+  IdentifierInfo *receiverNamePtr = &receiverName;
+  ObjCInterfaceDecl *IFace = getObjCInterfaceDecl(receiverNamePtr,
+                                                  receiverNameLoc);
+
+  bool IsSuper = false;
+  if (IFace == 0) {
+    // If the "receiver" is 'super' in a method, handle it as an expression-like
+    // property reference.
+    if (receiverNamePtr->isStr("super")) {
+      IsSuper = true;
+
+      if (ObjCMethodDecl *CurMethod = tryCaptureObjCSelf(receiverNameLoc)) {
+        if (CurMethod->isInstanceMethod()) {
+          QualType T = 
+            Context.getObjCInterfaceType(CurMethod->getClassInterface());
+          T = Context.getObjCObjectPointerType(T);
+        
+          return HandleExprPropertyRefExpr(T->getAsObjCInterfacePointerType(),
+                                           /*BaseExpr*/0, 
+                                           SourceLocation()/*OpLoc*/, 
+                                           &propertyName,
+                                           propertyNameLoc,
+                                           receiverNameLoc, T, true);
+        }
+
+        // Otherwise, if this is a class method, try dispatching to our
+        // superclass.
+        IFace = CurMethod->getClassInterface()->getSuperClass();
+      }
+    }
+    
+    if (IFace == 0) {
+      Diag(receiverNameLoc, diag::err_expected_ident_or_lparen);
+      return ExprError();
+    }
+  }
+
+  // Search for a declared property first.
+  Selector Sel = PP.getSelectorTable().getNullarySelector(&propertyName);
+  ObjCMethodDecl *Getter = IFace->lookupClassMethod(Sel);
+
+  // If this reference is in an @implementation, check for 'private' methods.
+  if (!Getter)
+    if (ObjCMethodDecl *CurMeth = getCurMethodDecl())
+      if (ObjCInterfaceDecl *ClassDecl = CurMeth->getClassInterface())
+        if (ObjCImplementationDecl *ImpDecl = ClassDecl->getImplementation())
+          Getter = ImpDecl->getClassMethod(Sel);
+
+  if (Getter) {
+    // FIXME: refactor/share with ActOnMemberReference().
+    // Check if we can reference this property.
+    if (DiagnoseUseOfDecl(Getter, propertyNameLoc))
+      return ExprError();
+  }
+
+  // Look for the matching setter, in case it is needed.
+  Selector SetterSel =
+    SelectorTable::constructSetterName(PP.getIdentifierTable(),
+                                       PP.getSelectorTable(), &propertyName);
+
+  ObjCMethodDecl *Setter = IFace->lookupClassMethod(SetterSel);
+  if (!Setter) {
+    // If this reference is in an @implementation, also check for 'private'
+    // methods.
+    if (ObjCMethodDecl *CurMeth = getCurMethodDecl())
+      if (ObjCInterfaceDecl *ClassDecl = CurMeth->getClassInterface())
+        if (ObjCImplementationDecl *ImpDecl = ClassDecl->getImplementation())
+          Setter = ImpDecl->getClassMethod(SetterSel);
+  }
+  // Look through local category implementations associated with the class.
+  if (!Setter)
+    Setter = IFace->getCategoryClassMethod(SetterSel);
+
+  if (Setter && DiagnoseUseOfDecl(Setter, propertyNameLoc))
+    return ExprError();
+
+  if (Getter || Setter) {
+    if (IsSuper)
+    return Owned(new (Context) ObjCPropertyRefExpr(Getter, Setter,
+                                                   Context.PseudoObjectTy,
+                                                   VK_LValue, OK_ObjCProperty,
+                                                   propertyNameLoc,
+                                                   receiverNameLoc, 
+                                          Context.getObjCInterfaceType(IFace)));
+
+    return Owned(new (Context) ObjCPropertyRefExpr(Getter, Setter,
+                                                   Context.PseudoObjectTy,
+                                                   VK_LValue, OK_ObjCProperty,
+                                                   propertyNameLoc,
+                                                   receiverNameLoc, IFace));
+  }
+  return ExprError(Diag(propertyNameLoc, diag::err_property_not_found)
+                     << &propertyName << Context.getObjCInterfaceType(IFace));
+}
+
+namespace {
+
+class ObjCInterfaceOrSuperCCC : public CorrectionCandidateCallback {
+ public:
+  ObjCInterfaceOrSuperCCC(ObjCMethodDecl *Method) {
+    // Determine whether "super" is acceptable in the current context.
+    if (Method && Method->getClassInterface())
+      WantObjCSuper = Method->getClassInterface()->getSuperClass();
+  }
+
+  virtual bool ValidateCandidate(const TypoCorrection &candidate) {
+    return candidate.getCorrectionDeclAs<ObjCInterfaceDecl>() ||
+        candidate.isKeyword("super");
+  }
+};
+
+}
+
+Sema::ObjCMessageKind Sema::getObjCMessageKind(Scope *S,
+                                               IdentifierInfo *Name,
+                                               SourceLocation NameLoc,
+                                               bool IsSuper,
+                                               bool HasTrailingDot,
+                                               ParsedType &ReceiverType) {
+  ReceiverType = ParsedType();
+
+  // If the identifier is "super" and there is no trailing dot, we're
+  // messaging super. If the identifier is "super" and there is a
+  // trailing dot, it's an instance message.
+  if (IsSuper && S->isInObjcMethodScope())
+    return HasTrailingDot? ObjCInstanceMessage : ObjCSuperMessage;
+  
+  LookupResult Result(*this, Name, NameLoc, LookupOrdinaryName);
+  LookupName(Result, S);
+  
+  switch (Result.getResultKind()) {
+  case LookupResult::NotFound:
+    // Normal name lookup didn't find anything. If we're in an
+    // Objective-C method, look for ivars. If we find one, we're done!
+    // FIXME: This is a hack. Ivar lookup should be part of normal
+    // lookup.
+    if (ObjCMethodDecl *Method = getCurMethodDecl()) {
+      if (!Method->getClassInterface()) {
+        // Fall back: let the parser try to parse it as an instance message.
+        return ObjCInstanceMessage;
+      }
+
+      ObjCInterfaceDecl *ClassDeclared;
+      if (Method->getClassInterface()->lookupInstanceVariable(Name, 
+                                                              ClassDeclared))
+        return ObjCInstanceMessage;
+    }
+  
+    // Break out; we'll perform typo correction below.
+    break;
+
+  case LookupResult::NotFoundInCurrentInstantiation:
+  case LookupResult::FoundOverloaded:
+  case LookupResult::FoundUnresolvedValue:
+  case LookupResult::Ambiguous:
+    Result.suppressDiagnostics();
+    return ObjCInstanceMessage;
+
+  case LookupResult::Found: {
+    // If the identifier is a class or not, and there is a trailing dot,
+    // it's an instance message.
+    if (HasTrailingDot)
+      return ObjCInstanceMessage;
+    // We found something. If it's a type, then we have a class
+    // message. Otherwise, it's an instance message.
+    NamedDecl *ND = Result.getFoundDecl();
+    QualType T;
+    if (ObjCInterfaceDecl *Class = dyn_cast<ObjCInterfaceDecl>(ND))
+      T = Context.getObjCInterfaceType(Class);
+    else if (TypeDecl *Type = dyn_cast<TypeDecl>(ND))
+      T = Context.getTypeDeclType(Type);
+    else 
+      return ObjCInstanceMessage;
+
+    //  We have a class message, and T is the type we're
+    //  messaging. Build source-location information for it.
+    TypeSourceInfo *TSInfo = Context.getTrivialTypeSourceInfo(T, NameLoc);
+    ReceiverType = CreateParsedType(T, TSInfo);
+    return ObjCClassMessage;
+  }
+  }
+
+  ObjCInterfaceOrSuperCCC Validator(getCurMethodDecl());
+  if (TypoCorrection Corrected = CorrectTypo(Result.getLookupNameInfo(),
+                                             Result.getLookupKind(), S, NULL,
+                                             Validator)) {
+    if (Corrected.isKeyword()) {
+      // If we've found the keyword "super" (the only keyword that would be
+      // returned by CorrectTypo), this is a send to super.
+      Diag(NameLoc, diag::err_unknown_receiver_suggest)
+        << Name << Corrected.getCorrection()
+        << FixItHint::CreateReplacement(SourceRange(NameLoc), "super");
+      return ObjCSuperMessage;
+    } else if (ObjCInterfaceDecl *Class =
+               Corrected.getCorrectionDeclAs<ObjCInterfaceDecl>()) {
+      // If we found a declaration, correct when it refers to an Objective-C
+      // class.
+      Diag(NameLoc, diag::err_unknown_receiver_suggest)
+        << Name << Corrected.getCorrection()
+        << FixItHint::CreateReplacement(SourceRange(NameLoc),
+                                        Class->getNameAsString());
+      Diag(Class->getLocation(), diag::note_previous_decl)
+        << Corrected.getCorrection();
+
+      QualType T = Context.getObjCInterfaceType(Class);
+      TypeSourceInfo *TSInfo = Context.getTrivialTypeSourceInfo(T, NameLoc);
+      ReceiverType = CreateParsedType(T, TSInfo);
+      return ObjCClassMessage;
+    }
+  }
+  
+  // Fall back: let the parser try to parse it as an instance message.
+  return ObjCInstanceMessage;
+}
+
+ExprResult Sema::ActOnSuperMessage(Scope *S, 
+                                   SourceLocation SuperLoc,
+                                   Selector Sel,
+                                   SourceLocation LBracLoc,
+                                   ArrayRef<SourceLocation> SelectorLocs,
+                                   SourceLocation RBracLoc,
+                                   MultiExprArg Args) {
+  // Determine whether we are inside a method or not.
+  ObjCMethodDecl *Method = tryCaptureObjCSelf(SuperLoc);
+  if (!Method) {
+    Diag(SuperLoc, diag::err_invalid_receiver_to_message_super);
+    return ExprError();
+  }
+
+  ObjCInterfaceDecl *Class = Method->getClassInterface();
+  if (!Class) {
+    Diag(SuperLoc, diag::error_no_super_class_message)
+      << Method->getDeclName();
+    return ExprError();
+  }
+
+  ObjCInterfaceDecl *Super = Class->getSuperClass();
+  if (!Super) {
+    // The current class does not have a superclass.
+    Diag(SuperLoc, diag::error_root_class_cannot_use_super)
+      << Class->getIdentifier();
+    return ExprError();
+  }
+
+  // We are in a method whose class has a superclass, so 'super'
+  // is acting as a keyword.
+  if (Method->isInstanceMethod()) {
+    if (Sel.getMethodFamily() == OMF_dealloc)
+      ObjCShouldCallSuperDealloc = false;
+    if (Sel.getMethodFamily() == OMF_finalize)
+      ObjCShouldCallSuperFinalize = false;
+
+    // Since we are in an instance method, this is an instance
+    // message to the superclass instance.
+    QualType SuperTy = Context.getObjCInterfaceType(Super);
+    SuperTy = Context.getObjCObjectPointerType(SuperTy);
+    return BuildInstanceMessage(0, SuperTy, SuperLoc,
+                                Sel, /*Method=*/0,
+                                LBracLoc, SelectorLocs, RBracLoc, move(Args));
+  }
+  
+  // Since we are in a class method, this is a class message to
+  // the superclass.
+  return BuildClassMessage(/*ReceiverTypeInfo=*/0,
+                           Context.getObjCInterfaceType(Super),
+                           SuperLoc, Sel, /*Method=*/0,
+                           LBracLoc, SelectorLocs, RBracLoc, move(Args));
+}
+
+
+ExprResult Sema::BuildClassMessageImplicit(QualType ReceiverType,
+                                           bool isSuperReceiver,
+                                           SourceLocation Loc,
+                                           Selector Sel,
+                                           ObjCMethodDecl *Method,
+                                           MultiExprArg Args) {
+  TypeSourceInfo *receiverTypeInfo = 0;
+  if (!ReceiverType.isNull())
+    receiverTypeInfo = Context.getTrivialTypeSourceInfo(ReceiverType);
+
+  return BuildClassMessage(receiverTypeInfo, ReceiverType,
+                          /*SuperLoc=*/isSuperReceiver ? Loc : SourceLocation(),
+                           Sel, Method, Loc, Loc, Loc, Args,
+                           /*isImplicit=*/true);
+
+}
+
+static void applyCocoaAPICheck(Sema &S, const ObjCMessageExpr *Msg,
+                               unsigned DiagID,
+                               bool (*refactor)(const ObjCMessageExpr *,
+                                              const NSAPI &, edit::Commit &)) {
+  SourceLocation MsgLoc = Msg->getExprLoc();
+  if (S.Diags.getDiagnosticLevel(DiagID, MsgLoc) == DiagnosticsEngine::Ignored)
+    return;
+
+  SourceManager &SM = S.SourceMgr;
+  edit::Commit ECommit(SM, S.LangOpts);
+  if (refactor(Msg,*S.NSAPIObj, ECommit)) {
+    DiagnosticBuilder Builder = S.Diag(MsgLoc, DiagID)
+                        << Msg->getSelector() << Msg->getSourceRange();
+    // FIXME: Don't emit diagnostic at all if fixits are non-commitable.
+    if (!ECommit.isCommitable())
+      return;
+    for (edit::Commit::edit_iterator
+           I = ECommit.edit_begin(), E = ECommit.edit_end(); I != E; ++I) {
+      const edit::Commit::Edit &Edit = *I;
+      switch (Edit.Kind) {
+      case edit::Commit::Act_Insert:
+        Builder.AddFixItHint(FixItHint::CreateInsertion(Edit.OrigLoc,
+                                                        Edit.Text,
+                                                        Edit.BeforePrev));
+        break;
+      case edit::Commit::Act_InsertFromRange:
+        Builder.AddFixItHint(
+            FixItHint::CreateInsertionFromRange(Edit.OrigLoc,
+                                                Edit.getInsertFromRange(SM),
+                                                Edit.BeforePrev));
+        break;
+      case edit::Commit::Act_Remove:
+        Builder.AddFixItHint(FixItHint::CreateRemoval(Edit.getFileRange(SM)));
+        break;
+      }
+    }
+  }
+}
+
+static void checkCocoaAPI(Sema &S, const ObjCMessageExpr *Msg) {
+  applyCocoaAPICheck(S, Msg, diag::warn_objc_redundant_literal_use,
+                     edit::rewriteObjCRedundantCallWithLiteral);
+}
+
+/// \brief Build an Objective-C class message expression.
+///
+/// This routine takes care of both normal class messages and
+/// class messages to the superclass.
+///
+/// \param ReceiverTypeInfo Type source information that describes the
+/// receiver of this message. This may be NULL, in which case we are
+/// sending to the superclass and \p SuperLoc must be a valid source
+/// location.
+
+/// \param ReceiverType The type of the object receiving the
+/// message. When \p ReceiverTypeInfo is non-NULL, this is the same
+/// type as that refers to. For a superclass send, this is the type of
+/// the superclass.
+///
+/// \param SuperLoc The location of the "super" keyword in a
+/// superclass message.
+///
+/// \param Sel The selector to which the message is being sent.
+///
+/// \param Method The method that this class message is invoking, if
+/// already known.
+///
+/// \param LBracLoc The location of the opening square bracket ']'.
+///
+/// \param RBrac The location of the closing square bracket ']'.
+///
+/// \param Args The message arguments.
+ExprResult Sema::BuildClassMessage(TypeSourceInfo *ReceiverTypeInfo,
+                                   QualType ReceiverType,
+                                   SourceLocation SuperLoc,
+                                   Selector Sel,
+                                   ObjCMethodDecl *Method,
+                                   SourceLocation LBracLoc, 
+                                   ArrayRef<SourceLocation> SelectorLocs,
+                                   SourceLocation RBracLoc,
+                                   MultiExprArg ArgsIn,
+                                   bool isImplicit) {
+  SourceLocation Loc = SuperLoc.isValid()? SuperLoc
+    : ReceiverTypeInfo->getTypeLoc().getSourceRange().getBegin();
+  if (LBracLoc.isInvalid()) {
+    Diag(Loc, diag::err_missing_open_square_message_send)
+      << FixItHint::CreateInsertion(Loc, "[");
+    LBracLoc = Loc;
+  }
+  
+  if (ReceiverType->isDependentType()) {
+    // If the receiver type is dependent, we can't type-check anything
+    // at this point. Build a dependent expression.
+    unsigned NumArgs = ArgsIn.size();
+    Expr **Args = reinterpret_cast<Expr **>(ArgsIn.release());
+    assert(SuperLoc.isInvalid() && "Message to super with dependent type");
+    return Owned(ObjCMessageExpr::Create(Context, ReceiverType,
+                                         VK_RValue, LBracLoc, ReceiverTypeInfo,
+                                         Sel, SelectorLocs, /*Method=*/0,
+                                         makeArrayRef(Args, NumArgs),RBracLoc,
+                                         isImplicit));
+  }
+  
+  // Find the class to which we are sending this message.
+  ObjCInterfaceDecl *Class = 0;
+  const ObjCObjectType *ClassType = ReceiverType->getAs<ObjCObjectType>();
+  if (!ClassType || !(Class = ClassType->getInterface())) {
+    Diag(Loc, diag::err_invalid_receiver_class_message)
+      << ReceiverType;
+    return ExprError();
+  }
+  assert(Class && "We don't know which class we're messaging?");
+  // objc++ diagnoses during typename annotation.
+  if (!getLangOpts().CPlusPlus)
+    (void)DiagnoseUseOfDecl(Class, Loc);
+  // Find the method we are messaging.
+  if (!Method) {
+    SourceRange TypeRange 
+      = SuperLoc.isValid()? SourceRange(SuperLoc)
+                          : ReceiverTypeInfo->getTypeLoc().getSourceRange();
+    if (RequireCompleteType(Loc, Context.getObjCInterfaceType(Class), 
+                            (getLangOpts().ObjCAutoRefCount
+                               ? PDiag(diag::err_arc_receiver_forward_class)
+                               : PDiag(diag::warn_receiver_forward_class))
+                                   << TypeRange)) {
+      // A forward class used in messaging is treated as a 'Class'
+      Method = LookupFactoryMethodInGlobalPool(Sel, 
+                                               SourceRange(LBracLoc, RBracLoc));
+      if (Method && !getLangOpts().ObjCAutoRefCount)
+        Diag(Method->getLocation(), diag::note_method_sent_forward_class)
+          << Method->getDeclName();
+    }
+    if (!Method)
+      Method = Class->lookupClassMethod(Sel);
+
+    // If we have an implementation in scope, check "private" methods.
+    if (!Method)
+      Method = LookupPrivateClassMethod(Sel, Class);
+
+    if (Method && DiagnoseUseOfDecl(Method, Loc))
+      return ExprError();
+  }
+
+  // Check the argument types and determine the result type.
+  QualType ReturnType;
+  ExprValueKind VK = VK_RValue;
+
+  unsigned NumArgs = ArgsIn.size();
+  Expr **Args = reinterpret_cast<Expr **>(ArgsIn.release());
+  if (CheckMessageArgumentTypes(ReceiverType, Args, NumArgs, Sel, Method, true,
+                                SuperLoc.isValid(), LBracLoc, RBracLoc, 
+                                ReturnType, VK))
+    return ExprError();
+
+  if (Method && !Method->getResultType()->isVoidType() &&
+      RequireCompleteType(LBracLoc, Method->getResultType(), 
+                          diag::err_illegal_message_expr_incomplete_type))
+    return ExprError();
+
+  // Construct the appropriate ObjCMessageExpr.
+  ObjCMessageExpr *Result;
+  if (SuperLoc.isValid())
+    Result = ObjCMessageExpr::Create(Context, ReturnType, VK, LBracLoc, 
+                                     SuperLoc, /*IsInstanceSuper=*/false, 
+                                     ReceiverType, Sel, SelectorLocs,
+                                     Method, makeArrayRef(Args, NumArgs),
+                                     RBracLoc, isImplicit);
+  else {
+    Result = ObjCMessageExpr::Create(Context, ReturnType, VK, LBracLoc, 
+                                     ReceiverTypeInfo, Sel, SelectorLocs,
+                                     Method, makeArrayRef(Args, NumArgs),
+                                     RBracLoc, isImplicit);
+    if (!isImplicit)
+      checkCocoaAPI(*this, Result);
+  }
+  return MaybeBindToTemporary(Result);
+}
+
+// ActOnClassMessage - used for both unary and keyword messages.
+// ArgExprs is optional - if it is present, the number of expressions
+// is obtained from Sel.getNumArgs().
+ExprResult Sema::ActOnClassMessage(Scope *S, 
+                                   ParsedType Receiver,
+                                   Selector Sel,
+                                   SourceLocation LBracLoc,
+                                   ArrayRef<SourceLocation> SelectorLocs,
+                                   SourceLocation RBracLoc,
+                                   MultiExprArg Args) {
+  TypeSourceInfo *ReceiverTypeInfo;
+  QualType ReceiverType = GetTypeFromParser(Receiver, &ReceiverTypeInfo);
+  if (ReceiverType.isNull())
+    return ExprError();
+
+
+  if (!ReceiverTypeInfo)
+    ReceiverTypeInfo = Context.getTrivialTypeSourceInfo(ReceiverType, LBracLoc);
+
+  return BuildClassMessage(ReceiverTypeInfo, ReceiverType, 
+                           /*SuperLoc=*/SourceLocation(), Sel, /*Method=*/0,
+                           LBracLoc, SelectorLocs, RBracLoc, move(Args));
+}
+
+ExprResult Sema::BuildInstanceMessageImplicit(Expr *Receiver,
+                                              QualType ReceiverType,
+                                              SourceLocation Loc,
+                                              Selector Sel,
+                                              ObjCMethodDecl *Method,
+                                              MultiExprArg Args) {
+  return BuildInstanceMessage(Receiver, ReceiverType,
+                              /*SuperLoc=*/!Receiver ? Loc : SourceLocation(),
+                              Sel, Method, Loc, Loc, Loc, Args,
+                              /*isImplicit=*/true);
+}
+
+/// \brief Build an Objective-C instance message expression.
+///
+/// This routine takes care of both normal instance messages and
+/// instance messages to the superclass instance.
+///
+/// \param Receiver The expression that computes the object that will
+/// receive this message. This may be empty, in which case we are
+/// sending to the superclass instance and \p SuperLoc must be a valid
+/// source location.
+///
+/// \param ReceiverType The (static) type of the object receiving the
+/// message. When a \p Receiver expression is provided, this is the
+/// same type as that expression. For a superclass instance send, this
+/// is a pointer to the type of the superclass.
+///
+/// \param SuperLoc The location of the "super" keyword in a
+/// superclass instance message.
+///
+/// \param Sel The selector to which the message is being sent.
+///
+/// \param Method The method that this instance message is invoking, if
+/// already known.
+///
+/// \param LBracLoc The location of the opening square bracket ']'.
+///
+/// \param RBrac The location of the closing square bracket ']'.
+///
+/// \param Args The message arguments.
+ExprResult Sema::BuildInstanceMessage(Expr *Receiver,
+                                      QualType ReceiverType,
+                                      SourceLocation SuperLoc,
+                                      Selector Sel,
+                                      ObjCMethodDecl *Method,
+                                      SourceLocation LBracLoc, 
+                                      ArrayRef<SourceLocation> SelectorLocs,
+                                      SourceLocation RBracLoc,
+                                      MultiExprArg ArgsIn,
+                                      bool isImplicit) {
+  // The location of the receiver.
+  SourceLocation Loc = SuperLoc.isValid()? SuperLoc : Receiver->getLocStart();
+  
+  if (LBracLoc.isInvalid()) {
+    Diag(Loc, diag::err_missing_open_square_message_send)
+      << FixItHint::CreateInsertion(Loc, "[");
+    LBracLoc = Loc;
+  }
+
+  // If we have a receiver expression, perform appropriate promotions
+  // and determine receiver type.
+  if (Receiver) {
+    if (Receiver->hasPlaceholderType()) {
+      ExprResult Result;
+      if (Receiver->getType() == Context.UnknownAnyTy)
+        Result = forceUnknownAnyToType(Receiver, Context.getObjCIdType());
+      else
+        Result = CheckPlaceholderExpr(Receiver);
+      if (Result.isInvalid()) return ExprError();
+      Receiver = Result.take();
+    }
+
+    if (Receiver->isTypeDependent()) {
+      // If the receiver is type-dependent, we can't type-check anything
+      // at this point. Build a dependent expression.
+      unsigned NumArgs = ArgsIn.size();
+      Expr **Args = reinterpret_cast<Expr **>(ArgsIn.release());
+      assert(SuperLoc.isInvalid() && "Message to super with dependent type");
+      return Owned(ObjCMessageExpr::Create(Context, Context.DependentTy,
+                                           VK_RValue, LBracLoc, Receiver, Sel, 
+                                           SelectorLocs, /*Method=*/0,
+                                           makeArrayRef(Args, NumArgs),
+                                           RBracLoc, isImplicit));
+    }
+
+    // If necessary, apply function/array conversion to the receiver.
+    // C99 6.7.5.3p[7,8].
+    ExprResult Result = DefaultFunctionArrayLvalueConversion(Receiver);
+    if (Result.isInvalid())
+      return ExprError();
+    Receiver = Result.take();
+    ReceiverType = Receiver->getType();
+  }
+
+  if (!Method) {
+    // Handle messages to id.
+    bool receiverIsId = ReceiverType->isObjCIdType();
+    if (receiverIsId || ReceiverType->isBlockPointerType() ||
+        (Receiver && Context.isObjCNSObjectType(Receiver->getType()))) {
+      Method = LookupInstanceMethodInGlobalPool(Sel, 
+                                                SourceRange(LBracLoc, RBracLoc),
+                                                receiverIsId);
+      if (!Method)
+        Method = LookupFactoryMethodInGlobalPool(Sel, 
+                                                 SourceRange(LBracLoc, RBracLoc),
+                                                 receiverIsId);
+    } else if (ReceiverType->isObjCClassType() ||
+               ReceiverType->isObjCQualifiedClassType()) {
+      // Handle messages to Class.
+      // We allow sending a message to a qualified Class ("Class<foo>"), which 
+      // is ok as long as one of the protocols implements the selector (if not, warn).
+      if (const ObjCObjectPointerType *QClassTy 
+            = ReceiverType->getAsObjCQualifiedClassType()) {
+        // Search protocols for class methods.
+        Method = LookupMethodInQualifiedType(Sel, QClassTy, false);
+        if (!Method) {
+          Method = LookupMethodInQualifiedType(Sel, QClassTy, true);
+          // warn if instance method found for a Class message.
+          if (Method) {
+            Diag(Loc, diag::warn_instance_method_on_class_found)
+              << Method->getSelector() << Sel;
+            Diag(Method->getLocation(), diag::note_method_declared_at)
+              << Method->getDeclName();
+          }
+        }
+      } else {
+        if (ObjCMethodDecl *CurMeth = getCurMethodDecl()) {
+          if (ObjCInterfaceDecl *ClassDecl = CurMeth->getClassInterface()) {
+            // First check the public methods in the class interface.
+            Method = ClassDecl->lookupClassMethod(Sel);
+
+            if (!Method)
+              Method = LookupPrivateClassMethod(Sel, ClassDecl);
+          }
+          if (Method && DiagnoseUseOfDecl(Method, Loc))
+            return ExprError();
+        }
+        if (!Method) {
+          // If not messaging 'self', look for any factory method named 'Sel'.
+          if (!Receiver || !isSelfExpr(Receiver)) {
+            Method = LookupFactoryMethodInGlobalPool(Sel, 
+                                                SourceRange(LBracLoc, RBracLoc),
+                                                     true);
+            if (!Method) {
+              // If no class (factory) method was found, check if an _instance_
+              // method of the same name exists in the root class only.
+              Method = LookupInstanceMethodInGlobalPool(Sel,
+                                               SourceRange(LBracLoc, RBracLoc),
+                                                        true);
+              if (Method)
+                  if (const ObjCInterfaceDecl *ID =
+                      dyn_cast<ObjCInterfaceDecl>(Method->getDeclContext())) {
+                    if (ID->getSuperClass())
+                      Diag(Loc, diag::warn_root_inst_method_not_found)
+                      << Sel << SourceRange(LBracLoc, RBracLoc);
+                  }
+            }
+          }
+        }
+      }
+    } else {
+      ObjCInterfaceDecl* ClassDecl = 0;
+
+      // We allow sending a message to a qualified ID ("id<foo>"), which is ok as
+      // long as one of the protocols implements the selector (if not, warn).
+      if (const ObjCObjectPointerType *QIdTy 
+                                   = ReceiverType->getAsObjCQualifiedIdType()) {
+        // Search protocols for instance methods.
+        Method = LookupMethodInQualifiedType(Sel, QIdTy, true);
+        if (!Method)
+          Method = LookupMethodInQualifiedType(Sel, QIdTy, false);
+      } else if (const ObjCObjectPointerType *OCIType
+                   = ReceiverType->getAsObjCInterfacePointerType()) {
+        // We allow sending a message to a pointer to an interface (an object).
+        ClassDecl = OCIType->getInterfaceDecl();
+
+        // Try to complete the type. Under ARC, this is a hard error from which
+        // we don't try to recover.
+        const ObjCInterfaceDecl *forwardClass = 0;
+        if (RequireCompleteType(Loc, OCIType->getPointeeType(),
+              getLangOpts().ObjCAutoRefCount
+                ? PDiag(diag::err_arc_receiver_forward_instance)
+                    << (Receiver ? Receiver->getSourceRange() 
+                                 : SourceRange(SuperLoc))
+                : PDiag(diag::warn_receiver_forward_instance)
+                    << (Receiver ? Receiver->getSourceRange() 
+                                 : SourceRange(SuperLoc)))) {
+          if (getLangOpts().ObjCAutoRefCount)
+            return ExprError();
+          
+          forwardClass = OCIType->getInterfaceDecl();
+          Diag(Receiver ? Receiver->getLocStart() 
+                        : SuperLoc, diag::note_receiver_is_id);
+          Method = 0;
+        } else {
+          Method = ClassDecl->lookupInstanceMethod(Sel);
+        }
+
+        if (!Method)
+          // Search protocol qualifiers.
+          Method = LookupMethodInQualifiedType(Sel, OCIType, true);
+        
+        if (!Method) {
+          // If we have implementations in scope, check "private" methods.
+          Method = LookupPrivateInstanceMethod(Sel, ClassDecl);
+
+          if (!Method && getLangOpts().ObjCAutoRefCount) {
+            Diag(Loc, diag::err_arc_may_not_respond)
+              << OCIType->getPointeeType() << Sel;
+            return ExprError();
+          }
+
+          if (!Method && (!Receiver || !isSelfExpr(Receiver))) {
+            // If we still haven't found a method, look in the global pool. This
+            // behavior isn't very desirable, however we need it for GCC
+            // compatibility. FIXME: should we deviate??
+            if (OCIType->qual_empty()) {
+              Method = LookupInstanceMethodInGlobalPool(Sel,
+                                                 SourceRange(LBracLoc, RBracLoc));
+              if (Method && !forwardClass)
+                Diag(Loc, diag::warn_maynot_respond)
+                  << OCIType->getInterfaceDecl()->getIdentifier() << Sel;
+            }
+          }
+        }
+        if (Method && DiagnoseUseOfDecl(Method, Loc, forwardClass))
+          return ExprError();
+      } else if (!getLangOpts().ObjCAutoRefCount &&
+                 !Context.getObjCIdType().isNull() &&
+                 (ReceiverType->isPointerType() || 
+                  ReceiverType->isIntegerType())) {
+        // Implicitly convert integers and pointers to 'id' but emit a warning.
+        // But not in ARC.
+        Diag(Loc, diag::warn_bad_receiver_type)
+          << ReceiverType 
+          << Receiver->getSourceRange();
+        if (ReceiverType->isPointerType())
+          Receiver = ImpCastExprToType(Receiver, Context.getObjCIdType(), 
+                            CK_CPointerToObjCPointerCast).take();
+        else {
+          // TODO: specialized warning on null receivers?
+          bool IsNull = Receiver->isNullPointerConstant(Context,
+                                              Expr::NPC_ValueDependentIsNull);
+          Receiver = ImpCastExprToType(Receiver, Context.getObjCIdType(),
+                            IsNull ? CK_NullToPointer : CK_IntegralToPointer).take();
+        }
+        ReceiverType = Receiver->getType();
+      } else {
+        ExprResult ReceiverRes;
+        if (getLangOpts().CPlusPlus)
+          ReceiverRes = PerformContextuallyConvertToObjCPointer(Receiver);
+        if (ReceiverRes.isUsable()) {
+          Receiver = ReceiverRes.take();
+          return BuildInstanceMessage(Receiver,
+                                      ReceiverType,
+                                      SuperLoc,
+                                      Sel,
+                                      Method,
+                                      LBracLoc,
+                                      SelectorLocs,
+                                      RBracLoc,
+                                      move(ArgsIn));
+        } else {
+          // Reject other random receiver types (e.g. structs).
+          Diag(Loc, diag::err_bad_receiver_type)
+            << ReceiverType << Receiver->getSourceRange();
+          return ExprError();
+        }
+      }
+    }
+  }
+
+  // Check the message arguments.
+  unsigned NumArgs = ArgsIn.size();
+  Expr **Args = reinterpret_cast<Expr **>(ArgsIn.release());
+  QualType ReturnType;
+  ExprValueKind VK = VK_RValue;
+  bool ClassMessage = (ReceiverType->isObjCClassType() ||
+                       ReceiverType->isObjCQualifiedClassType());
+  if (CheckMessageArgumentTypes(ReceiverType, Args, NumArgs, Sel, Method, 
+                                ClassMessage, SuperLoc.isValid(), 
+                                LBracLoc, RBracLoc, ReturnType, VK))
+    return ExprError();
+  
+  if (Method && !Method->getResultType()->isVoidType() &&
+      RequireCompleteType(LBracLoc, Method->getResultType(), 
+                          diag::err_illegal_message_expr_incomplete_type))
+    return ExprError();
+
+  SourceLocation SelLoc = SelectorLocs.front();
+
+  // In ARC, forbid the user from sending messages to 
+  // retain/release/autorelease/dealloc/retainCount explicitly.
+  if (getLangOpts().ObjCAutoRefCount) {
+    ObjCMethodFamily family =
+      (Method ? Method->getMethodFamily() : Sel.getMethodFamily());
+    switch (family) {
+    case OMF_init:
+      if (Method)
+        checkInitMethod(Method, ReceiverType);
+
+    case OMF_None:
+    case OMF_alloc:
+    case OMF_copy:
+    case OMF_finalize:
+    case OMF_mutableCopy:
+    case OMF_new:
+    case OMF_self:
+      break;
+
+    case OMF_dealloc:
+    case OMF_retain:
+    case OMF_release:
+    case OMF_autorelease:
+    case OMF_retainCount:
+      Diag(Loc, diag::err_arc_illegal_explicit_message)
+        << Sel << SelLoc;
+      break;
+    
+    case OMF_performSelector:
+      if (Method && NumArgs >= 1) {
+        if (ObjCSelectorExpr *SelExp = dyn_cast<ObjCSelectorExpr>(Args[0])) {
+          Selector ArgSel = SelExp->getSelector();
+          ObjCMethodDecl *SelMethod = 
+            LookupInstanceMethodInGlobalPool(ArgSel,
+                                             SelExp->getSourceRange());
+          if (!SelMethod)
+            SelMethod =
+              LookupFactoryMethodInGlobalPool(ArgSel,
+                                              SelExp->getSourceRange());
+          if (SelMethod) {
+            ObjCMethodFamily SelFamily = SelMethod->getMethodFamily();
+            switch (SelFamily) {
+              case OMF_alloc:
+              case OMF_copy:
+              case OMF_mutableCopy:
+              case OMF_new:
+              case OMF_self:
+              case OMF_init:
+                // Issue error, unless ns_returns_not_retained.
+                if (!SelMethod->hasAttr<NSReturnsNotRetainedAttr>()) {
+                  // selector names a +1 method 
+                  Diag(SelLoc, 
+                       diag::err_arc_perform_selector_retains);
+                  Diag(SelMethod->getLocation(), diag::note_method_declared_at)
+                    << SelMethod->getDeclName();
+                }
+                break;
+              default:
+                // +0 call. OK. unless ns_returns_retained.
+                if (SelMethod->hasAttr<NSReturnsRetainedAttr>()) {
+                  // selector names a +1 method
+                  Diag(SelLoc, 
+                       diag::err_arc_perform_selector_retains);
+                  Diag(SelMethod->getLocation(), diag::note_method_declared_at)
+                    << SelMethod->getDeclName();
+                }
+                break;
+            }
+          }
+        } else {
+          // error (may leak).
+          Diag(SelLoc, diag::warn_arc_perform_selector_leaks);
+          Diag(Args[0]->getExprLoc(), diag::note_used_here);
+        }
+      }
+      break;
+    }
+  }
+
+  // Construct the appropriate ObjCMessageExpr instance.
+  ObjCMessageExpr *Result;
+  if (SuperLoc.isValid())
+    Result = ObjCMessageExpr::Create(Context, ReturnType, VK, LBracLoc,
+                                     SuperLoc,  /*IsInstanceSuper=*/true,
+                                     ReceiverType, Sel, SelectorLocs, Method, 
+                                     makeArrayRef(Args, NumArgs), RBracLoc,
+                                     isImplicit);
+  else {
+    Result = ObjCMessageExpr::Create(Context, ReturnType, VK, LBracLoc,
+                                     Receiver, Sel, SelectorLocs, Method,
+                                     makeArrayRef(Args, NumArgs), RBracLoc,
+                                     isImplicit);
+    if (!isImplicit)
+      checkCocoaAPI(*this, Result);
+  }
+
+  if (getLangOpts().ObjCAutoRefCount) {
+    if (Receiver &&
+        (Receiver->IgnoreParenImpCasts()->getType().getObjCLifetime() 
+          == Qualifiers::OCL_Weak))
+      Diag(Receiver->getLocStart(), diag::warn_receiver_is_weak);
+    
+    // In ARC, annotate delegate init calls.
+    if (Result->getMethodFamily() == OMF_init &&
+        (SuperLoc.isValid() || isSelfExpr(Receiver))) {
+      // Only consider init calls *directly* in init implementations,
+      // not within blocks.
+      ObjCMethodDecl *method = dyn_cast<ObjCMethodDecl>(CurContext);
+      if (method && method->getMethodFamily() == OMF_init) {
+        // The implicit assignment to self means we also don't want to
+        // consume the result.
+        Result->setDelegateInitCall(true);
+        return Owned(Result);
+      }
+    }
+
+    // In ARC, check for message sends which are likely to introduce
+    // retain cycles.
+    checkRetainCycles(Result);
+  }
+      
+  return MaybeBindToTemporary(Result);
+}
+
+// ActOnInstanceMessage - used for both unary and keyword messages.
+// ArgExprs is optional - if it is present, the number of expressions
+// is obtained from Sel.getNumArgs().
+ExprResult Sema::ActOnInstanceMessage(Scope *S,
+                                      Expr *Receiver, 
+                                      Selector Sel,
+                                      SourceLocation LBracLoc,
+                                      ArrayRef<SourceLocation> SelectorLocs,
+                                      SourceLocation RBracLoc,
+                                      MultiExprArg Args) {
+  if (!Receiver)
+    return ExprError();
+
+  return BuildInstanceMessage(Receiver, Receiver->getType(),
+                              /*SuperLoc=*/SourceLocation(), Sel, /*Method=*/0, 
+                              LBracLoc, SelectorLocs, RBracLoc, move(Args));
+}
+
+enum ARCConversionTypeClass {
+  /// int, void, struct A
+  ACTC_none,
+
+  /// id, void (^)()
+  ACTC_retainable,
+
+  /// id*, id***, void (^*)(),
+  ACTC_indirectRetainable,
+
+  /// void* might be a normal C type, or it might a CF type.
+  ACTC_voidPtr,
+
+  /// struct A*
+  ACTC_coreFoundation
+};
+static bool isAnyRetainable(ARCConversionTypeClass ACTC) {
+  return (ACTC == ACTC_retainable ||
+          ACTC == ACTC_coreFoundation ||
+          ACTC == ACTC_voidPtr);
+}
+static bool isAnyCLike(ARCConversionTypeClass ACTC) {
+  return ACTC == ACTC_none ||
+         ACTC == ACTC_voidPtr ||
+         ACTC == ACTC_coreFoundation;
+}
+
+static ARCConversionTypeClass classifyTypeForARCConversion(QualType type) {
+  bool isIndirect = false;
+  
+  // Ignore an outermost reference type.
+  if (const ReferenceType *ref = type->getAs<ReferenceType>()) {
+    type = ref->getPointeeType();
+    isIndirect = true;
+  }
+  
+  // Drill through pointers and arrays recursively.
+  while (true) {
+    if (const PointerType *ptr = type->getAs<PointerType>()) {
+      type = ptr->getPointeeType();
+
+      // The first level of pointer may be the innermost pointer on a CF type.
+      if (!isIndirect) {
+        if (type->isVoidType()) return ACTC_voidPtr;
+        if (type->isRecordType()) return ACTC_coreFoundation;
+      }
+    } else if (const ArrayType *array = type->getAsArrayTypeUnsafe()) {
+      type = QualType(array->getElementType()->getBaseElementTypeUnsafe(), 0);
+    } else {
+      break;
+    }
+    isIndirect = true;
+  }
+  
+  if (isIndirect) {
+    if (type->isObjCARCBridgableType())
+      return ACTC_indirectRetainable;
+    return ACTC_none;
+  }
+
+  if (type->isObjCARCBridgableType())
+    return ACTC_retainable;
+
+  return ACTC_none;
+}
+
+namespace {
+  /// A result from the cast checker.
+  enum ACCResult {
+    /// Cannot be casted.
+    ACC_invalid,
+
+    /// Can be safely retained or not retained.
+    ACC_bottom,
+
+    /// Can be casted at +0.
+    ACC_plusZero,
+
+    /// Can be casted at +1.
+    ACC_plusOne
+  };
+  ACCResult merge(ACCResult left, ACCResult right) {
+    if (left == right) return left;
+    if (left == ACC_bottom) return right;
+    if (right == ACC_bottom) return left;
+    return ACC_invalid;
+  }
+
+  /// A checker which white-lists certain expressions whose conversion
+  /// to or from retainable type would otherwise be forbidden in ARC.
+  class ARCCastChecker : public StmtVisitor<ARCCastChecker, ACCResult> {
+    typedef StmtVisitor<ARCCastChecker, ACCResult> super;
+
+    ASTContext &Context;
+    ARCConversionTypeClass SourceClass;
+    ARCConversionTypeClass TargetClass;
+
+    static bool isCFType(QualType type) {
+      // Someday this can use ns_bridged.  For now, it has to do this.
+      return type->isCARCBridgableType();
+    }
+
+  public:
+    ARCCastChecker(ASTContext &Context, ARCConversionTypeClass source,
+                   ARCConversionTypeClass target)
+      : Context(Context), SourceClass(source), TargetClass(target) {}
+
+    using super::Visit;
+    ACCResult Visit(Expr *e) {
+      return super::Visit(e->IgnoreParens());
+    }
+
+    ACCResult VisitStmt(Stmt *s) {
+      return ACC_invalid;
+    }
+
+    /// Null pointer constants can be casted however you please.
+    ACCResult VisitExpr(Expr *e) {
+      if (e->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNotNull))
+        return ACC_bottom;
+      return ACC_invalid;
+    }
+
+    /// Objective-C string literals can be safely casted.
+    ACCResult VisitObjCStringLiteral(ObjCStringLiteral *e) {
+      // If we're casting to any retainable type, go ahead.  Global
+      // strings are immune to retains, so this is bottom.
+      if (isAnyRetainable(TargetClass)) return ACC_bottom;
+
+      return ACC_invalid;
+    }
+    
+    /// Look through certain implicit and explicit casts.
+    ACCResult VisitCastExpr(CastExpr *e) {
+      switch (e->getCastKind()) {
+        case CK_NullToPointer:
+          return ACC_bottom;
+
+        case CK_NoOp:
+        case CK_LValueToRValue:
+        case CK_BitCast:
+        case CK_CPointerToObjCPointerCast:
+        case CK_BlockPointerToObjCPointerCast:
+        case CK_AnyPointerToBlockPointerCast:
+          return Visit(e->getSubExpr());
+
+        default:
+          return ACC_invalid;
+      }
+    }
+
+    /// Look through unary extension.
+    ACCResult VisitUnaryExtension(UnaryOperator *e) {
+      return Visit(e->getSubExpr());
+    }
+
+    /// Ignore the LHS of a comma operator.
+    ACCResult VisitBinComma(BinaryOperator *e) {
+      return Visit(e->getRHS());
+    }
+
+    /// Conditional operators are okay if both sides are okay.
+    ACCResult VisitConditionalOperator(ConditionalOperator *e) {
+      ACCResult left = Visit(e->getTrueExpr());
+      if (left == ACC_invalid) return ACC_invalid;
+      return merge(left, Visit(e->getFalseExpr()));
+    }
+
+    /// Look through pseudo-objects.
+    ACCResult VisitPseudoObjectExpr(PseudoObjectExpr *e) {
+      // If we're getting here, we should always have a result.
+      return Visit(e->getResultExpr());
+    }
+
+    /// Statement expressions are okay if their result expression is okay.
+    ACCResult VisitStmtExpr(StmtExpr *e) {
+      return Visit(e->getSubStmt()->body_back());
+    }
+
+    /// Some declaration references are okay.
+    ACCResult VisitDeclRefExpr(DeclRefExpr *e) {
+      // References to global constants from system headers are okay.
+      // These are things like 'kCFStringTransformToLatin'.  They are
+      // can also be assumed to be immune to retains.
+      VarDecl *var = dyn_cast<VarDecl>(e->getDecl());
+      if (isAnyRetainable(TargetClass) &&
+          isAnyRetainable(SourceClass) &&
+          var &&
+          var->getStorageClass() == SC_Extern &&
+          var->getType().isConstQualified() &&
+          Context.getSourceManager().isInSystemHeader(var->getLocation())) {
+        return ACC_bottom;
+      }
+
+      // Nothing else.
+      return ACC_invalid;
+    }
+
+    /// Some calls are okay.
+    ACCResult VisitCallExpr(CallExpr *e) {
+      if (FunctionDecl *fn = e->getDirectCallee())
+        if (ACCResult result = checkCallToFunction(fn))
+          return result;
+
+      return super::VisitCallExpr(e);
+    }
+
+    ACCResult checkCallToFunction(FunctionDecl *fn) {
+      // Require a CF*Ref return type.
+      if (!isCFType(fn->getResultType()))
+        return ACC_invalid;
+
+      if (!isAnyRetainable(TargetClass))
+        return ACC_invalid;
+
+      // Honor an explicit 'not retained' attribute.
+      if (fn->hasAttr<CFReturnsNotRetainedAttr>())
+        return ACC_plusZero;
+
+      // Honor an explicit 'retained' attribute, except that for
+      // now we're not going to permit implicit handling of +1 results,
+      // because it's a bit frightening.
+      if (fn->hasAttr<CFReturnsRetainedAttr>())
+        return ACC_invalid; // ACC_plusOne if we start accepting this
+
+      // Recognize this specific builtin function, which is used by CFSTR.
+      unsigned builtinID = fn->getBuiltinID();
+      if (builtinID == Builtin::BI__builtin___CFStringMakeConstantString)
+        return ACC_bottom;
+
+      // Otherwise, don't do anything implicit with an unaudited function.
+      if (!fn->hasAttr<CFAuditedTransferAttr>())
+        return ACC_invalid;
+
+      // Otherwise, it's +0 unless it follows the create convention.
+      if (ento::coreFoundation::followsCreateRule(fn))
+        return ACC_invalid; // ACC_plusOne if we start accepting this
+
+      return ACC_plusZero;
+    }
+
+    ACCResult VisitObjCMessageExpr(ObjCMessageExpr *e) {
+      return checkCallToMethod(e->getMethodDecl());
+    }
+
+    ACCResult VisitObjCPropertyRefExpr(ObjCPropertyRefExpr *e) {
+      ObjCMethodDecl *method;
+      if (e->isExplicitProperty())
+        method = e->getExplicitProperty()->getGetterMethodDecl();
+      else
+        method = e->getImplicitPropertyGetter();
+      return checkCallToMethod(method);
+    }
+
+    ACCResult checkCallToMethod(ObjCMethodDecl *method) {
+      if (!method) return ACC_invalid;
+
+      // Check for message sends to functions returning CF types.  We
+      // just obey the Cocoa conventions with these, even though the
+      // return type is CF.
+      if (!isAnyRetainable(TargetClass) || !isCFType(method->getResultType()))
+        return ACC_invalid;
+      
+      // If the method is explicitly marked not-retained, it's +0.
+      if (method->hasAttr<CFReturnsNotRetainedAttr>())
+        return ACC_plusZero;
+
+      // If the method is explicitly marked as returning retained, or its
+      // selector follows a +1 Cocoa convention, treat it as +1.
+      if (method->hasAttr<CFReturnsRetainedAttr>())
+        return ACC_plusOne;
+
+      switch (method->getSelector().getMethodFamily()) {
+      case OMF_alloc:
+      case OMF_copy:
+      case OMF_mutableCopy:
+      case OMF_new:
+        return ACC_plusOne;
+
+      default:
+        // Otherwise, treat it as +0.
+        return ACC_plusZero;
+      }
+    }
+  };
+}
+
+static bool
+KnownName(Sema &S, const char *name) {
+  LookupResult R(S, &S.Context.Idents.get(name), SourceLocation(),
+                 Sema::LookupOrdinaryName);
+  return S.LookupName(R, S.TUScope, false);
+}
+
+static void addFixitForObjCARCConversion(Sema &S,
+                                         DiagnosticBuilder &DiagB,
+                                         Sema::CheckedConversionKind CCK,
+                                         SourceLocation afterLParen,
+                                         QualType castType,
+                                         Expr *castExpr,
+                                         const char *bridgeKeyword,
+                                         const char *CFBridgeName) {
+  // We handle C-style and implicit casts here.
+  switch (CCK) {
+  case Sema::CCK_ImplicitConversion:
+  case Sema::CCK_CStyleCast:
+    break;
+  case Sema::CCK_FunctionalCast:
+  case Sema::CCK_OtherCast:
+    return;
+  }
+
+  if (CFBridgeName) {
+    Expr *castedE = castExpr;
+    if (CStyleCastExpr *CCE = dyn_cast<CStyleCastExpr>(castedE))
+      castedE = CCE->getSubExpr();
+    castedE = castedE->IgnoreImpCasts();
+    SourceRange range = castedE->getSourceRange();
+    if (isa<ParenExpr>(castedE)) {
+      DiagB.AddFixItHint(FixItHint::CreateInsertion(range.getBegin(),
+                         CFBridgeName));
+    } else {
+      std::string namePlusParen = CFBridgeName;
+      namePlusParen += "(";
+      DiagB.AddFixItHint(FixItHint::CreateInsertion(range.getBegin(),
+                                                    namePlusParen));
+      DiagB.AddFixItHint(FixItHint::CreateInsertion(
+                                       S.PP.getLocForEndOfToken(range.getEnd()),
+                                       ")"));
+    }
+    return;
+  }
+
+  if (CCK == Sema::CCK_CStyleCast) {
+    DiagB.AddFixItHint(FixItHint::CreateInsertion(afterLParen, bridgeKeyword));
+  } else {
+    std::string castCode = "(";
+    castCode += bridgeKeyword;
+    castCode += castType.getAsString();
+    castCode += ")";
+    Expr *castedE = castExpr->IgnoreImpCasts();
+    SourceRange range = castedE->getSourceRange();
+    if (isa<ParenExpr>(castedE)) {
+      DiagB.AddFixItHint(FixItHint::CreateInsertion(range.getBegin(),
+                         castCode));
+    } else {
+      castCode += "(";
+      DiagB.AddFixItHint(FixItHint::CreateInsertion(range.getBegin(),
+                                                    castCode));
+      DiagB.AddFixItHint(FixItHint::CreateInsertion(
+                                       S.PP.getLocForEndOfToken(range.getEnd()),
+                                       ")"));
+    }
+  }
+}
+
+static void
+diagnoseObjCARCConversion(Sema &S, SourceRange castRange,
+                          QualType castType, ARCConversionTypeClass castACTC,
+                          Expr *castExpr, ARCConversionTypeClass exprACTC,
+                          Sema::CheckedConversionKind CCK) {
+  SourceLocation loc =
+    (castRange.isValid() ? castRange.getBegin() : castExpr->getExprLoc());
+  
+  if (S.makeUnavailableInSystemHeader(loc,
+                "converts between Objective-C and C pointers in -fobjc-arc"))
+    return;
+
+  QualType castExprType = castExpr->getType();
+  
+  unsigned srcKind = 0;
+  switch (exprACTC) {
+  case ACTC_none:
+  case ACTC_coreFoundation:
+  case ACTC_voidPtr:
+    srcKind = (castExprType->isPointerType() ? 1 : 0);
+    break;
+  case ACTC_retainable:
+    srcKind = (castExprType->isBlockPointerType() ? 2 : 3);
+    break;
+  case ACTC_indirectRetainable:
+    srcKind = 4;
+    break;
+  }
+  
+  // Check whether this could be fixed with a bridge cast.
+  SourceLocation afterLParen = S.PP.getLocForEndOfToken(castRange.getBegin());
+  SourceLocation noteLoc = afterLParen.isValid() ? afterLParen : loc;
+
+  // Bridge from an ARC type to a CF type.
+  if (castACTC == ACTC_retainable && isAnyRetainable(exprACTC)) {
+
+    S.Diag(loc, diag::err_arc_cast_requires_bridge)
+      << unsigned(CCK == Sema::CCK_ImplicitConversion) // cast|implicit
+      << 2 // of C pointer type
+      << castExprType
+      << unsigned(castType->isBlockPointerType()) // to ObjC|block type
+      << castType
+      << castRange
+      << castExpr->getSourceRange();
+    bool br = KnownName(S, "CFBridgingRelease");
+    {
+      DiagnosticBuilder DiagB = S.Diag(noteLoc, diag::note_arc_bridge);
+      addFixitForObjCARCConversion(S, DiagB, CCK, afterLParen,
+                                   castType, castExpr, "__bridge ", 0);
+    }
+    {
+      DiagnosticBuilder DiagB = S.Diag(noteLoc, diag::note_arc_bridge_transfer)
+        << castExprType << br;
+      addFixitForObjCARCConversion(S, DiagB, CCK, afterLParen,
+                                   castType, castExpr, "__bridge_transfer ",
+                                   br ? "CFBridgingRelease" : 0);
+    }
+
+    return;
+  }
+    
+  // Bridge from a CF type to an ARC type.
+  if (exprACTC == ACTC_retainable && isAnyRetainable(castACTC)) {
+    bool br = KnownName(S, "CFBridgingRetain");
+    S.Diag(loc, diag::err_arc_cast_requires_bridge)
+      << unsigned(CCK == Sema::CCK_ImplicitConversion) // cast|implicit
+      << unsigned(castExprType->isBlockPointerType()) // of ObjC|block type
+      << castExprType
+      << 2 // to C pointer type
+      << castType
+      << castRange
+      << castExpr->getSourceRange();
+
+    {
+      DiagnosticBuilder DiagB = S.Diag(noteLoc, diag::note_arc_bridge);
+      addFixitForObjCARCConversion(S, DiagB, CCK, afterLParen,
+                                   castType, castExpr, "__bridge ", 0);
+    }
+    {
+      DiagnosticBuilder DiagB = S.Diag(noteLoc, diag::note_arc_bridge_retained)
+        << castType << br;
+      addFixitForObjCARCConversion(S, DiagB, CCK, afterLParen,
+                                   castType, castExpr, "__bridge_retained ",
+                                   br ? "CFBridgingRetain" : 0);
+    }
+
+    return;
+  }
+  
+  S.Diag(loc, diag::err_arc_mismatched_cast)
+    << (CCK != Sema::CCK_ImplicitConversion)
+    << srcKind << castExprType << castType
+    << castRange << castExpr->getSourceRange();
+}
+
+Sema::ARCConversionResult
+Sema::CheckObjCARCConversion(SourceRange castRange, QualType castType,
+                             Expr *&castExpr, CheckedConversionKind CCK) {
+  QualType castExprType = castExpr->getType();
+
+  // For the purposes of the classification, we assume reference types
+  // will bind to temporaries.
+  QualType effCastType = castType;
+  if (const ReferenceType *ref = castType->getAs<ReferenceType>())
+    effCastType = ref->getPointeeType();
+  
+  ARCConversionTypeClass exprACTC = classifyTypeForARCConversion(castExprType);
+  ARCConversionTypeClass castACTC = classifyTypeForARCConversion(effCastType);
+  if (exprACTC == castACTC) {
+    // check for viablity and report error if casting an rvalue to a
+    // life-time qualifier.
+    if ((castACTC == ACTC_retainable) &&
+        (CCK == CCK_CStyleCast || CCK == CCK_OtherCast) &&
+        (castType != castExprType)) {
+      const Type *DT = castType.getTypePtr();
+      QualType QDT = castType;
+      // We desugar some types but not others. We ignore those
+      // that cannot happen in a cast; i.e. auto, and those which
+      // should not be de-sugared; i.e typedef.
+      if (const ParenType *PT = dyn_cast<ParenType>(DT))
+        QDT = PT->desugar();
+      else if (const TypeOfType *TP = dyn_cast<TypeOfType>(DT))
+        QDT = TP->desugar();
+      else if (const AttributedType *AT = dyn_cast<AttributedType>(DT))
+        QDT = AT->desugar();
+      if (QDT != castType &&
+          QDT.getObjCLifetime() !=  Qualifiers::OCL_None) {
+        SourceLocation loc =
+          (castRange.isValid() ? castRange.getBegin() 
+                              : castExpr->getExprLoc());
+        Diag(loc, diag::err_arc_nolifetime_behavior);
+      }
+    }
+    return ACR_okay;
+  }
+  
+  if (isAnyCLike(exprACTC) && isAnyCLike(castACTC)) return ACR_okay;
+
+  // Allow all of these types to be cast to integer types (but not
+  // vice-versa).
+  if (castACTC == ACTC_none && castType->isIntegralType(Context))
+    return ACR_okay;
+  
+  // Allow casts between pointers to lifetime types (e.g., __strong id*)
+  // and pointers to void (e.g., cv void *). Casting from void* to lifetime*
+  // must be explicit.
+  if (exprACTC == ACTC_indirectRetainable && castACTC == ACTC_voidPtr)
+    return ACR_okay;
+  if (castACTC == ACTC_indirectRetainable && exprACTC == ACTC_voidPtr &&
+      CCK != CCK_ImplicitConversion)
+    return ACR_okay;
+
+  switch (ARCCastChecker(Context, exprACTC, castACTC).Visit(castExpr)) {
+  // For invalid casts, fall through.
+  case ACC_invalid:
+    break;
+
+  // Do nothing for both bottom and +0.
+  case ACC_bottom:
+  case ACC_plusZero:
+    return ACR_okay;
+
+  // If the result is +1, consume it here.
+  case ACC_plusOne:
+    castExpr = ImplicitCastExpr::Create(Context, castExpr->getType(),
+                                        CK_ARCConsumeObject, castExpr,
+                                        0, VK_RValue);
+    ExprNeedsCleanups = true;
+    return ACR_okay;
+  }
+
+  // If this is a non-implicit cast from id or block type to a
+  // CoreFoundation type, delay complaining in case the cast is used
+  // in an acceptable context.
+  if (exprACTC == ACTC_retainable && isAnyRetainable(castACTC) &&
+      CCK != CCK_ImplicitConversion)
+    return ACR_unbridged;
+
+  diagnoseObjCARCConversion(*this, castRange, castType, castACTC,
+                            castExpr, exprACTC, CCK);
+  return ACR_okay;
+}
+
+/// Given that we saw an expression with the ARCUnbridgedCastTy
+/// placeholder type, complain bitterly.
+void Sema::diagnoseARCUnbridgedCast(Expr *e) {
+  // We expect the spurious ImplicitCastExpr to already have been stripped.
+  assert(!e->hasPlaceholderType(BuiltinType::ARCUnbridgedCast));
+  CastExpr *realCast = cast<CastExpr>(e->IgnoreParens());
+
+  SourceRange castRange;
+  QualType castType;
+  CheckedConversionKind CCK;
+
+  if (CStyleCastExpr *cast = dyn_cast<CStyleCastExpr>(realCast)) {
+    castRange = SourceRange(cast->getLParenLoc(), cast->getRParenLoc());
+    castType = cast->getTypeAsWritten();
+    CCK = CCK_CStyleCast;
+  } else if (ExplicitCastExpr *cast = dyn_cast<ExplicitCastExpr>(realCast)) {
+    castRange = cast->getTypeInfoAsWritten()->getTypeLoc().getSourceRange();
+    castType = cast->getTypeAsWritten();
+    CCK = CCK_OtherCast;
+  } else {
+    castType = cast->getType();
+    CCK = CCK_ImplicitConversion;
+  }
+
+  ARCConversionTypeClass castACTC =
+    classifyTypeForARCConversion(castType.getNonReferenceType());
+
+  Expr *castExpr = realCast->getSubExpr();
+  assert(classifyTypeForARCConversion(castExpr->getType()) == ACTC_retainable);
+
+  diagnoseObjCARCConversion(*this, castRange, castType, castACTC,
+                            castExpr, ACTC_retainable, CCK);
+}
+
+/// stripARCUnbridgedCast - Given an expression of ARCUnbridgedCast
+/// type, remove the placeholder cast.
+Expr *Sema::stripARCUnbridgedCast(Expr *e) {
+  assert(e->hasPlaceholderType(BuiltinType::ARCUnbridgedCast));
+
+  if (ParenExpr *pe = dyn_cast<ParenExpr>(e)) {
+    Expr *sub = stripARCUnbridgedCast(pe->getSubExpr());
+    return new (Context) ParenExpr(pe->getLParen(), pe->getRParen(), sub);
+  } else if (UnaryOperator *uo = dyn_cast<UnaryOperator>(e)) {
+    assert(uo->getOpcode() == UO_Extension);
+    Expr *sub = stripARCUnbridgedCast(uo->getSubExpr());
+    return new (Context) UnaryOperator(sub, UO_Extension, sub->getType(),
+                                   sub->getValueKind(), sub->getObjectKind(),
+                                       uo->getOperatorLoc());
+  } else if (GenericSelectionExpr *gse = dyn_cast<GenericSelectionExpr>(e)) {
+    assert(!gse->isResultDependent());
+
+    unsigned n = gse->getNumAssocs();
+    SmallVector<Expr*, 4> subExprs(n);
+    SmallVector<TypeSourceInfo*, 4> subTypes(n);
+    for (unsigned i = 0; i != n; ++i) {
+      subTypes[i] = gse->getAssocTypeSourceInfo(i);
+      Expr *sub = gse->getAssocExpr(i);
+      if (i == gse->getResultIndex())
+        sub = stripARCUnbridgedCast(sub);
+      subExprs[i] = sub;
+    }
+
+    return new (Context) GenericSelectionExpr(Context, gse->getGenericLoc(),
+                                              gse->getControllingExpr(),
+                                              subTypes.data(), subExprs.data(),
+                                              n, gse->getDefaultLoc(),
+                                              gse->getRParenLoc(),
+                                       gse->containsUnexpandedParameterPack(),
+                                              gse->getResultIndex());
+  } else {
+    assert(isa<ImplicitCastExpr>(e) && "bad form of unbridged cast!");
+    return cast<ImplicitCastExpr>(e)->getSubExpr();
+  }
+}
+
+bool Sema::CheckObjCARCUnavailableWeakConversion(QualType castType,
+                                                 QualType exprType) {
+  QualType canCastType = 
+    Context.getCanonicalType(castType).getUnqualifiedType();
+  QualType canExprType = 
+    Context.getCanonicalType(exprType).getUnqualifiedType();
+  if (isa<ObjCObjectPointerType>(canCastType) &&
+      castType.getObjCLifetime() == Qualifiers::OCL_Weak &&
+      canExprType->isObjCObjectPointerType()) {
+    if (const ObjCObjectPointerType *ObjT =
+        canExprType->getAs<ObjCObjectPointerType>())
+      if (ObjT->getInterfaceDecl()->isArcWeakrefUnavailable())
+        return false;
+  }
+  return true;
+}
+
+/// Look for an ObjCReclaimReturnedObject cast and destroy it.
+static Expr *maybeUndoReclaimObject(Expr *e) {
+  // For now, we just undo operands that are *immediately* reclaim
+  // expressions, which prevents the vast majority of potential
+  // problems here.  To catch them all, we'd need to rebuild arbitrary
+  // value-propagating subexpressions --- we can't reliably rebuild
+  // in-place because of expression sharing.
+  if (ImplicitCastExpr *ice = dyn_cast<ImplicitCastExpr>(e))
+    if (ice->getCastKind() == CK_ARCReclaimReturnedObject)
+      return ice->getSubExpr();
+
+  return e;
+}
+
+ExprResult Sema::BuildObjCBridgedCast(SourceLocation LParenLoc,
+                                      ObjCBridgeCastKind Kind,
+                                      SourceLocation BridgeKeywordLoc,
+                                      TypeSourceInfo *TSInfo,
+                                      Expr *SubExpr) {
+  ExprResult SubResult = UsualUnaryConversions(SubExpr);
+  if (SubResult.isInvalid()) return ExprError();
+  SubExpr = SubResult.take();
+
+  QualType T = TSInfo->getType();
+  QualType FromType = SubExpr->getType();
+
+  CastKind CK;
+
+  bool MustConsume = false;
+  if (T->isDependentType() || SubExpr->isTypeDependent()) {
+    // Okay: we'll build a dependent expression type.
+    CK = CK_Dependent;
+  } else if (T->isObjCARCBridgableType() && FromType->isCARCBridgableType()) {
+    // Casting CF -> id
+    CK = (T->isBlockPointerType() ? CK_AnyPointerToBlockPointerCast
+                                  : CK_CPointerToObjCPointerCast);
+    switch (Kind) {
+    case OBC_Bridge:
+      break;
+      
+    case OBC_BridgeRetained: {
+      bool br = KnownName(*this, "CFBridgingRelease");
+      Diag(BridgeKeywordLoc, diag::err_arc_bridge_cast_wrong_kind)
+        << 2
+        << FromType
+        << (T->isBlockPointerType()? 1 : 0)
+        << T
+        << SubExpr->getSourceRange()
+        << Kind;
+      Diag(BridgeKeywordLoc, diag::note_arc_bridge)
+        << FixItHint::CreateReplacement(BridgeKeywordLoc, "__bridge");
+      Diag(BridgeKeywordLoc, diag::note_arc_bridge_transfer)
+        << FromType << br
+        << FixItHint::CreateReplacement(BridgeKeywordLoc, 
+                                        br ? "CFBridgingRelease " 
+                                           : "__bridge_transfer ");
+
+      Kind = OBC_Bridge;
+      break;
+    }
+      
+    case OBC_BridgeTransfer:
+      // We must consume the Objective-C object produced by the cast.
+      MustConsume = true;
+      break;
+    }
+  } else if (T->isCARCBridgableType() && FromType->isObjCARCBridgableType()) {
+    // Okay: id -> CF
+    CK = CK_BitCast;
+    switch (Kind) {
+    case OBC_Bridge:
+      // Reclaiming a value that's going to be __bridge-casted to CF
+      // is very dangerous, so we don't do it.
+      SubExpr = maybeUndoReclaimObject(SubExpr);
+      break;
+      
+    case OBC_BridgeRetained:        
+      // Produce the object before casting it.
+      SubExpr = ImplicitCastExpr::Create(Context, FromType,
+                                         CK_ARCProduceObject,
+                                         SubExpr, 0, VK_RValue);
+      break;
+      
+    case OBC_BridgeTransfer: {
+      bool br = KnownName(*this, "CFBridgingRetain");
+      Diag(BridgeKeywordLoc, diag::err_arc_bridge_cast_wrong_kind)
+        << (FromType->isBlockPointerType()? 1 : 0)
+        << FromType
+        << 2
+        << T
+        << SubExpr->getSourceRange()
+        << Kind;
+        
+      Diag(BridgeKeywordLoc, diag::note_arc_bridge)
+        << FixItHint::CreateReplacement(BridgeKeywordLoc, "__bridge ");
+      Diag(BridgeKeywordLoc, diag::note_arc_bridge_retained)
+        << T << br
+        << FixItHint::CreateReplacement(BridgeKeywordLoc, 
+                          br ? "CFBridgingRetain " : "__bridge_retained");
+        
+      Kind = OBC_Bridge;
+      break;
+    }
+    }
+  } else {
+    Diag(LParenLoc, diag::err_arc_bridge_cast_incompatible)
+      << FromType << T << Kind
+      << SubExpr->getSourceRange()
+      << TSInfo->getTypeLoc().getSourceRange();
+    return ExprError();
+  }
+
+  Expr *Result = new (Context) ObjCBridgedCastExpr(LParenLoc, Kind, CK,
+                                                   BridgeKeywordLoc,
+                                                   TSInfo, SubExpr);
+  
+  if (MustConsume) {
+    ExprNeedsCleanups = true;
+    Result = ImplicitCastExpr::Create(Context, T, CK_ARCConsumeObject, Result, 
+                                      0, VK_RValue);    
+  }
+  
+  return Result;
+}
+
+ExprResult Sema::ActOnObjCBridgedCast(Scope *S,
+                                      SourceLocation LParenLoc,
+                                      ObjCBridgeCastKind Kind,
+                                      SourceLocation BridgeKeywordLoc,
+                                      ParsedType Type,
+                                      SourceLocation RParenLoc,
+                                      Expr *SubExpr) {
+  TypeSourceInfo *TSInfo = 0;
+  QualType T = GetTypeFromParser(Type, &TSInfo);
+  if (!TSInfo)
+    TSInfo = Context.getTrivialTypeSourceInfo(T, LParenLoc);
+  return BuildObjCBridgedCast(LParenLoc, Kind, BridgeKeywordLoc, TSInfo, 
+                              SubExpr);
+}