Check in LLVM r95781.
diff --git a/lib/Sema/SemaExprCXX.cpp b/lib/Sema/SemaExprCXX.cpp
new file mode 100644
index 0000000..e27308a
--- /dev/null
+++ b/lib/Sema/SemaExprCXX.cpp
@@ -0,0 +1,2196 @@
+//===--- SemaExprCXX.cpp - Semantic Analysis for 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 C++ expressions.
+//
+//===----------------------------------------------------------------------===//
+
+#include "Sema.h"
+#include "SemaInit.h"
+#include "Lookup.h"
+#include "clang/AST/ASTContext.h"
+#include "clang/AST/CXXInheritance.h"
+#include "clang/AST/ExprCXX.h"
+#include "clang/Basic/PartialDiagnostic.h"
+#include "clang/Basic/TargetInfo.h"
+#include "clang/Lex/Preprocessor.h"
+#include "clang/Parse/DeclSpec.h"
+#include "llvm/ADT/STLExtras.h"
+using namespace clang;
+
+/// ActOnCXXTypeidOfType - Parse typeid( type-id ).
+Action::OwningExprResult
+Sema::ActOnCXXTypeid(SourceLocation OpLoc, SourceLocation LParenLoc,
+                     bool isType, void *TyOrExpr, SourceLocation RParenLoc) {
+  if (!StdNamespace)
+    return ExprError(Diag(OpLoc, diag::err_need_header_before_typeid));
+
+  if (isType) {
+    // C++ [expr.typeid]p4:
+    //   The top-level cv-qualifiers of the lvalue expression or the type-id 
+    //   that is the operand of typeid are always ignored.
+    // FIXME: Preserve type source info.
+    // FIXME: Preserve the type before we stripped the cv-qualifiers?
+    QualType T = GetTypeFromParser(TyOrExpr);
+    if (T.isNull())
+      return ExprError();
+    
+    // C++ [expr.typeid]p4:
+    //   If the type of the type-id is a class type or a reference to a class 
+    //   type, the class shall be completely-defined.
+    QualType CheckT = T;
+    if (const ReferenceType *RefType = CheckT->getAs<ReferenceType>())
+      CheckT = RefType->getPointeeType();
+    
+    if (CheckT->getAs<RecordType>() &&
+        RequireCompleteType(OpLoc, CheckT, diag::err_incomplete_typeid))
+      return ExprError();
+    
+    TyOrExpr = T.getUnqualifiedType().getAsOpaquePtr();
+  }
+
+  IdentifierInfo *TypeInfoII = &PP.getIdentifierTable().get("type_info");
+  LookupResult R(*this, TypeInfoII, SourceLocation(), LookupTagName);
+  LookupQualifiedName(R, StdNamespace);
+  RecordDecl *TypeInfoRecordDecl = R.getAsSingle<RecordDecl>();
+  if (!TypeInfoRecordDecl)
+    return ExprError(Diag(OpLoc, diag::err_need_header_before_typeid));
+
+  QualType TypeInfoType = Context.getTypeDeclType(TypeInfoRecordDecl);
+
+  if (!isType) {
+    bool isUnevaluatedOperand = true;
+    Expr *E = static_cast<Expr *>(TyOrExpr);
+    if (E && !E->isTypeDependent()) {
+      QualType T = E->getType();
+      if (const RecordType *RecordT = T->getAs<RecordType>()) {
+        CXXRecordDecl *RecordD = cast<CXXRecordDecl>(RecordT->getDecl());
+        // C++ [expr.typeid]p3:
+        //   [...] If the type of the expression is a class type, the class
+        //   shall be completely-defined.
+        if (RequireCompleteType(OpLoc, T, diag::err_incomplete_typeid))
+          return ExprError();
+
+        // C++ [expr.typeid]p3:
+        //   When typeid is applied to an expression other than an lvalue of a
+        //   polymorphic class type [...] [the] expression is an unevaluated
+        //   operand. [...]
+        if (RecordD->isPolymorphic() && E->isLvalue(Context) == Expr::LV_Valid)
+          isUnevaluatedOperand = false;
+      }
+
+      // C++ [expr.typeid]p4:
+      //   [...] If the type of the type-id is a reference to a possibly
+      //   cv-qualified type, the result of the typeid expression refers to a 
+      //   std::type_info object representing the cv-unqualified referenced 
+      //   type.
+      if (T.hasQualifiers()) {
+        ImpCastExprToType(E, T.getUnqualifiedType(), CastExpr::CK_NoOp,
+                          E->isLvalue(Context));
+        TyOrExpr = E;
+      }
+    }
+
+    // If this is an unevaluated operand, clear out the set of
+    // declaration references we have been computing and eliminate any
+    // temporaries introduced in its computation.
+    if (isUnevaluatedOperand)
+      ExprEvalContexts.back().Context = Unevaluated;
+  }
+
+  return Owned(new (Context) CXXTypeidExpr(isType, TyOrExpr,
+                                           TypeInfoType.withConst(),
+                                           SourceRange(OpLoc, RParenLoc)));
+}
+
+/// ActOnCXXBoolLiteral - Parse {true,false} literals.
+Action::OwningExprResult
+Sema::ActOnCXXBoolLiteral(SourceLocation OpLoc, tok::TokenKind Kind) {
+  assert((Kind == tok::kw_true || Kind == tok::kw_false) &&
+         "Unknown C++ Boolean value!");
+  return Owned(new (Context) CXXBoolLiteralExpr(Kind == tok::kw_true,
+                                                Context.BoolTy, OpLoc));
+}
+
+/// ActOnCXXNullPtrLiteral - Parse 'nullptr'.
+Action::OwningExprResult
+Sema::ActOnCXXNullPtrLiteral(SourceLocation Loc) {
+  return Owned(new (Context) CXXNullPtrLiteralExpr(Context.NullPtrTy, Loc));
+}
+
+/// ActOnCXXThrow - Parse throw expressions.
+Action::OwningExprResult
+Sema::ActOnCXXThrow(SourceLocation OpLoc, ExprArg E) {
+  Expr *Ex = E.takeAs<Expr>();
+  if (Ex && !Ex->isTypeDependent() && CheckCXXThrowOperand(OpLoc, Ex))
+    return ExprError();
+  return Owned(new (Context) CXXThrowExpr(Ex, Context.VoidTy, OpLoc));
+}
+
+/// CheckCXXThrowOperand - Validate the operand of a throw.
+bool Sema::CheckCXXThrowOperand(SourceLocation ThrowLoc, Expr *&E) {
+  // C++ [except.throw]p3:
+  //   A throw-expression initializes a temporary object, called the exception
+  //   object, the type of which is determined by removing any top-level
+  //   cv-qualifiers from the static type of the operand of throw and adjusting
+  //   the type from "array of T" or "function returning T" to "pointer to T" 
+  //   or "pointer to function returning T", [...]
+  if (E->getType().hasQualifiers())
+    ImpCastExprToType(E, E->getType().getUnqualifiedType(), CastExpr::CK_NoOp,
+                      E->isLvalue(Context) == Expr::LV_Valid);
+  
+  DefaultFunctionArrayConversion(E);
+
+  //   If the type of the exception would be an incomplete type or a pointer
+  //   to an incomplete type other than (cv) void the program is ill-formed.
+  QualType Ty = E->getType();
+  int isPointer = 0;
+  if (const PointerType* Ptr = Ty->getAs<PointerType>()) {
+    Ty = Ptr->getPointeeType();
+    isPointer = 1;
+  }
+  if (!isPointer || !Ty->isVoidType()) {
+    if (RequireCompleteType(ThrowLoc, Ty,
+                            PDiag(isPointer ? diag::err_throw_incomplete_ptr
+                                            : diag::err_throw_incomplete)
+                              << E->getSourceRange()))
+      return true;
+  }
+
+  // FIXME: Construct a temporary here.
+  return false;
+}
+
+Action::OwningExprResult Sema::ActOnCXXThis(SourceLocation ThisLoc) {
+  /// C++ 9.3.2: In the body of a non-static member function, the keyword this
+  /// is a non-lvalue expression whose value is the address of the object for
+  /// which the function is called.
+
+  if (!isa<FunctionDecl>(CurContext))
+    return ExprError(Diag(ThisLoc, diag::err_invalid_this_use));
+
+  if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(CurContext))
+    if (MD->isInstance())
+      return Owned(new (Context) CXXThisExpr(ThisLoc,
+                                             MD->getThisType(Context),
+                                             /*isImplicit=*/false));
+
+  return ExprError(Diag(ThisLoc, diag::err_invalid_this_use));
+}
+
+/// ActOnCXXTypeConstructExpr - Parse construction of a specified type.
+/// Can be interpreted either as function-style casting ("int(x)")
+/// or class type construction ("ClassType(x,y,z)")
+/// or creation of a value-initialized type ("int()").
+Action::OwningExprResult
+Sema::ActOnCXXTypeConstructExpr(SourceRange TypeRange, TypeTy *TypeRep,
+                                SourceLocation LParenLoc,
+                                MultiExprArg exprs,
+                                SourceLocation *CommaLocs,
+                                SourceLocation RParenLoc) {
+  if (!TypeRep)
+    return ExprError();
+
+  TypeSourceInfo *TInfo;
+  QualType Ty = GetTypeFromParser(TypeRep, &TInfo);
+  if (!TInfo)
+    TInfo = Context.getTrivialTypeSourceInfo(Ty, SourceLocation());
+  unsigned NumExprs = exprs.size();
+  Expr **Exprs = (Expr**)exprs.get();
+  SourceLocation TyBeginLoc = TypeRange.getBegin();
+  SourceRange FullRange = SourceRange(TyBeginLoc, RParenLoc);
+
+  if (Ty->isDependentType() ||
+      CallExpr::hasAnyTypeDependentArguments(Exprs, NumExprs)) {
+    exprs.release();
+
+    return Owned(CXXUnresolvedConstructExpr::Create(Context,
+                                                    TypeRange.getBegin(), Ty,
+                                                    LParenLoc,
+                                                    Exprs, NumExprs,
+                                                    RParenLoc));
+  }
+
+  if (Ty->isArrayType())
+    return ExprError(Diag(TyBeginLoc,
+                          diag::err_value_init_for_array_type) << FullRange);
+  if (!Ty->isVoidType() &&
+      RequireCompleteType(TyBeginLoc, Ty,
+                          PDiag(diag::err_invalid_incomplete_type_use)
+                            << FullRange))
+    return ExprError();
+  
+  if (RequireNonAbstractType(TyBeginLoc, Ty,
+                             diag::err_allocation_of_abstract_type))
+    return ExprError();
+
+
+  // C++ [expr.type.conv]p1:
+  // If the expression list is a single expression, the type conversion
+  // expression is equivalent (in definedness, and if defined in meaning) to the
+  // corresponding cast expression.
+  //
+  if (NumExprs == 1) {
+    CastExpr::CastKind Kind = CastExpr::CK_Unknown;
+    CXXMethodDecl *Method = 0;
+    if (CheckCastTypes(TypeRange, Ty, Exprs[0], Kind, Method,
+                       /*FunctionalStyle=*/true))
+      return ExprError();
+
+    exprs.release();
+    if (Method) {
+      OwningExprResult CastArg 
+        = BuildCXXCastArgument(TypeRange.getBegin(), Ty.getNonReferenceType(), 
+                               Kind, Method, Owned(Exprs[0]));
+      if (CastArg.isInvalid())
+        return ExprError();
+
+      Exprs[0] = CastArg.takeAs<Expr>();
+    }
+
+    return Owned(new (Context) CXXFunctionalCastExpr(Ty.getNonReferenceType(),
+                                                     TInfo, TyBeginLoc, Kind,
+                                                     Exprs[0], RParenLoc));
+  }
+
+  if (const RecordType *RT = Ty->getAs<RecordType>()) {
+    CXXRecordDecl *Record = cast<CXXRecordDecl>(RT->getDecl());
+
+    if (NumExprs > 1 || !Record->hasTrivialConstructor() ||
+        !Record->hasTrivialDestructor()) {
+      InitializedEntity Entity = InitializedEntity::InitializeTemporary(Ty);
+      InitializationKind Kind
+        = NumExprs ? InitializationKind::CreateDirect(TypeRange.getBegin(), 
+                                                      LParenLoc, RParenLoc)
+                   : InitializationKind::CreateValue(TypeRange.getBegin(), 
+                                                     LParenLoc, RParenLoc);
+      InitializationSequence InitSeq(*this, Entity, Kind, Exprs, NumExprs);
+      OwningExprResult Result = InitSeq.Perform(*this, Entity, Kind,
+                                                move(exprs));
+
+      // FIXME: Improve AST representation?
+      return move(Result);
+    }
+
+    // Fall through to value-initialize an object of class type that
+    // doesn't have a user-declared default constructor.
+  }
+
+  // C++ [expr.type.conv]p1:
+  // If the expression list specifies more than a single value, the type shall
+  // be a class with a suitably declared constructor.
+  //
+  if (NumExprs > 1)
+    return ExprError(Diag(CommaLocs[0],
+                          diag::err_builtin_func_cast_more_than_one_arg)
+      << FullRange);
+
+  assert(NumExprs == 0 && "Expected 0 expressions");
+  // C++ [expr.type.conv]p2:
+  // The expression T(), where T is a simple-type-specifier for a non-array
+  // complete object type or the (possibly cv-qualified) void type, creates an
+  // rvalue of the specified type, which is value-initialized.
+  //
+  exprs.release();
+  return Owned(new (Context) CXXZeroInitValueExpr(Ty, TyBeginLoc, RParenLoc));
+}
+
+
+/// ActOnCXXNew - Parsed a C++ 'new' expression (C++ 5.3.4), as in e.g.:
+/// @code new (memory) int[size][4] @endcode
+/// or
+/// @code ::new Foo(23, "hello") @endcode
+/// For the interpretation of this heap of arguments, consult the base version.
+Action::OwningExprResult
+Sema::ActOnCXXNew(SourceLocation StartLoc, bool UseGlobal,
+                  SourceLocation PlacementLParen, MultiExprArg PlacementArgs,
+                  SourceLocation PlacementRParen, bool ParenTypeId,
+                  Declarator &D, SourceLocation ConstructorLParen,
+                  MultiExprArg ConstructorArgs,
+                  SourceLocation ConstructorRParen) {
+  Expr *ArraySize = 0;
+  // If the specified type is an array, unwrap it and save the expression.
+  if (D.getNumTypeObjects() > 0 &&
+      D.getTypeObject(0).Kind == DeclaratorChunk::Array) {
+    DeclaratorChunk &Chunk = D.getTypeObject(0);
+    if (Chunk.Arr.hasStatic)
+      return ExprError(Diag(Chunk.Loc, diag::err_static_illegal_in_new)
+        << D.getSourceRange());
+    if (!Chunk.Arr.NumElts)
+      return ExprError(Diag(Chunk.Loc, diag::err_array_new_needs_size)
+        << D.getSourceRange());
+
+    if (ParenTypeId) {
+      // Can't have dynamic array size when the type-id is in parentheses.
+      Expr *NumElts = (Expr *)Chunk.Arr.NumElts;
+      if (!NumElts->isTypeDependent() && !NumElts->isValueDependent() &&
+          !NumElts->isIntegerConstantExpr(Context)) {
+        Diag(D.getTypeObject(0).Loc, diag::err_new_paren_array_nonconst)
+          << NumElts->getSourceRange();
+        return ExprError();
+      }
+    }
+
+    ArraySize = static_cast<Expr*>(Chunk.Arr.NumElts);
+    D.DropFirstTypeObject();
+  }
+
+  // Every dimension shall be of constant size.
+  if (ArraySize) {
+    for (unsigned I = 0, N = D.getNumTypeObjects(); I < N; ++I) {
+      if (D.getTypeObject(I).Kind != DeclaratorChunk::Array)
+        break;
+
+      DeclaratorChunk::ArrayTypeInfo &Array = D.getTypeObject(I).Arr;
+      if (Expr *NumElts = (Expr *)Array.NumElts) {
+        if (!NumElts->isTypeDependent() && !NumElts->isValueDependent() &&
+            !NumElts->isIntegerConstantExpr(Context)) {
+          Diag(D.getTypeObject(I).Loc, diag::err_new_array_nonconst)
+            << NumElts->getSourceRange();
+          return ExprError();
+        }
+      }
+    }
+  }
+
+  //FIXME: Store TypeSourceInfo in CXXNew expression.
+  TypeSourceInfo *TInfo = 0;
+  QualType AllocType = GetTypeForDeclarator(D, /*Scope=*/0, &TInfo);
+  if (D.isInvalidType())
+    return ExprError();
+    
+  return BuildCXXNew(StartLoc, UseGlobal,
+                     PlacementLParen,
+                     move(PlacementArgs),
+                     PlacementRParen,
+                     ParenTypeId,
+                     AllocType,
+                     D.getSourceRange().getBegin(),
+                     D.getSourceRange(),
+                     Owned(ArraySize),
+                     ConstructorLParen,
+                     move(ConstructorArgs),
+                     ConstructorRParen);
+}
+
+Sema::OwningExprResult
+Sema::BuildCXXNew(SourceLocation StartLoc, bool UseGlobal,
+                  SourceLocation PlacementLParen,
+                  MultiExprArg PlacementArgs,
+                  SourceLocation PlacementRParen,
+                  bool ParenTypeId,
+                  QualType AllocType,
+                  SourceLocation TypeLoc,
+                  SourceRange TypeRange,
+                  ExprArg ArraySizeE,
+                  SourceLocation ConstructorLParen,
+                  MultiExprArg ConstructorArgs,
+                  SourceLocation ConstructorRParen) {
+  if (CheckAllocatedType(AllocType, TypeLoc, TypeRange))
+    return ExprError();
+
+  QualType ResultType = Context.getPointerType(AllocType);
+
+  // That every array dimension except the first is constant was already
+  // checked by the type check above.
+
+  // C++ 5.3.4p6: "The expression in a direct-new-declarator shall have integral
+  //   or enumeration type with a non-negative value."
+  Expr *ArraySize = (Expr *)ArraySizeE.get();
+  if (ArraySize && !ArraySize->isTypeDependent()) {
+    QualType SizeType = ArraySize->getType();
+    if (!SizeType->isIntegralType() && !SizeType->isEnumeralType())
+      return ExprError(Diag(ArraySize->getSourceRange().getBegin(),
+                            diag::err_array_size_not_integral)
+        << SizeType << ArraySize->getSourceRange());
+    // Let's see if this is a constant < 0. If so, we reject it out of hand.
+    // We don't care about special rules, so we tell the machinery it's not
+    // evaluated - it gives us a result in more cases.
+    if (!ArraySize->isValueDependent()) {
+      llvm::APSInt Value;
+      if (ArraySize->isIntegerConstantExpr(Value, Context, 0, false)) {
+        if (Value < llvm::APSInt(
+                        llvm::APInt::getNullValue(Value.getBitWidth()), 
+                                 Value.isUnsigned()))
+          return ExprError(Diag(ArraySize->getSourceRange().getBegin(),
+                           diag::err_typecheck_negative_array_size)
+            << ArraySize->getSourceRange());
+      }
+    }
+    
+    ImpCastExprToType(ArraySize, Context.getSizeType(),
+                      CastExpr::CK_IntegralCast);
+  }
+
+  FunctionDecl *OperatorNew = 0;
+  FunctionDecl *OperatorDelete = 0;
+  Expr **PlaceArgs = (Expr**)PlacementArgs.get();
+  unsigned NumPlaceArgs = PlacementArgs.size();
+  
+  if (!AllocType->isDependentType() &&
+      !Expr::hasAnyTypeDependentArguments(PlaceArgs, NumPlaceArgs) &&
+      FindAllocationFunctions(StartLoc,
+                              SourceRange(PlacementLParen, PlacementRParen),
+                              UseGlobal, AllocType, ArraySize, PlaceArgs,
+                              NumPlaceArgs, OperatorNew, OperatorDelete))
+    return ExprError();
+  llvm::SmallVector<Expr *, 8> AllPlaceArgs;
+  if (OperatorNew) {
+    // Add default arguments, if any.
+    const FunctionProtoType *Proto = 
+      OperatorNew->getType()->getAs<FunctionProtoType>();
+    VariadicCallType CallType = 
+      Proto->isVariadic() ? VariadicFunction : VariadicDoesNotApply;
+    bool Invalid = GatherArgumentsForCall(PlacementLParen, OperatorNew,
+                                          Proto, 1, PlaceArgs, NumPlaceArgs, 
+                                          AllPlaceArgs, CallType);
+    if (Invalid)
+      return ExprError();
+    
+    NumPlaceArgs = AllPlaceArgs.size();
+    if (NumPlaceArgs > 0)
+      PlaceArgs = &AllPlaceArgs[0];
+  }
+  
+  bool Init = ConstructorLParen.isValid();
+  // --- Choosing a constructor ---
+  CXXConstructorDecl *Constructor = 0;
+  Expr **ConsArgs = (Expr**)ConstructorArgs.get();
+  unsigned NumConsArgs = ConstructorArgs.size();
+  ASTOwningVector<&ActionBase::DeleteExpr> ConvertedConstructorArgs(*this);
+
+  if (!AllocType->isDependentType() &&
+      !Expr::hasAnyTypeDependentArguments(ConsArgs, NumConsArgs)) {
+    // C++0x [expr.new]p15:
+    //   A new-expression that creates an object of type T initializes that
+    //   object as follows:
+    InitializationKind Kind
+    //     - If the new-initializer is omitted, the object is default-
+    //       initialized (8.5); if no initialization is performed,
+    //       the object has indeterminate value
+      = !Init? InitializationKind::CreateDefault(TypeLoc)
+    //     - Otherwise, the new-initializer is interpreted according to the 
+    //       initialization rules of 8.5 for direct-initialization.
+             : InitializationKind::CreateDirect(TypeLoc,
+                                                ConstructorLParen, 
+                                                ConstructorRParen);
+    
+    InitializedEntity Entity
+      = InitializedEntity::InitializeNew(StartLoc, AllocType);
+    InitializationSequence InitSeq(*this, Entity, Kind, ConsArgs, NumConsArgs);
+    OwningExprResult FullInit = InitSeq.Perform(*this, Entity, Kind, 
+                                                move(ConstructorArgs));
+    if (FullInit.isInvalid())
+      return ExprError();
+    
+    // FullInit is our initializer; walk through it to determine if it's a 
+    // constructor call, which CXXNewExpr handles directly.
+    if (Expr *FullInitExpr = (Expr *)FullInit.get()) {
+      if (CXXBindTemporaryExpr *Binder
+            = dyn_cast<CXXBindTemporaryExpr>(FullInitExpr))
+        FullInitExpr = Binder->getSubExpr();
+      if (CXXConstructExpr *Construct
+                    = dyn_cast<CXXConstructExpr>(FullInitExpr)) {
+        Constructor = Construct->getConstructor();
+        for (CXXConstructExpr::arg_iterator A = Construct->arg_begin(),
+                                         AEnd = Construct->arg_end();
+             A != AEnd; ++A)
+          ConvertedConstructorArgs.push_back(A->Retain());
+      } else {
+        // Take the converted initializer.
+        ConvertedConstructorArgs.push_back(FullInit.release());
+      }
+    } else {
+      // No initialization required.
+    }
+    
+    // Take the converted arguments and use them for the new expression.
+    NumConsArgs = ConvertedConstructorArgs.size();
+    ConsArgs = (Expr **)ConvertedConstructorArgs.take();
+  }
+  
+  // FIXME: Also check that the destructor is accessible. (C++ 5.3.4p16)
+  
+  PlacementArgs.release();
+  ConstructorArgs.release();
+  ArraySizeE.release();
+  return Owned(new (Context) CXXNewExpr(UseGlobal, OperatorNew, PlaceArgs,
+                        NumPlaceArgs, ParenTypeId, ArraySize, Constructor, Init,
+                        ConsArgs, NumConsArgs, OperatorDelete, ResultType,
+                        StartLoc, Init ? ConstructorRParen : SourceLocation()));
+}
+
+/// CheckAllocatedType - Checks that a type is suitable as the allocated type
+/// in a new-expression.
+/// dimension off and stores the size expression in ArraySize.
+bool Sema::CheckAllocatedType(QualType AllocType, SourceLocation Loc,
+                              SourceRange R) {
+  // C++ 5.3.4p1: "[The] type shall be a complete object type, but not an
+  //   abstract class type or array thereof.
+  if (AllocType->isFunctionType())
+    return Diag(Loc, diag::err_bad_new_type)
+      << AllocType << 0 << R;
+  else if (AllocType->isReferenceType())
+    return Diag(Loc, diag::err_bad_new_type)
+      << AllocType << 1 << R;
+  else if (!AllocType->isDependentType() &&
+           RequireCompleteType(Loc, AllocType,
+                               PDiag(diag::err_new_incomplete_type)
+                                 << R))
+    return true;
+  else if (RequireNonAbstractType(Loc, AllocType,
+                                  diag::err_allocation_of_abstract_type))
+    return true;
+
+  return false;
+}
+
+/// FindAllocationFunctions - Finds the overloads of operator new and delete
+/// that are appropriate for the allocation.
+bool Sema::FindAllocationFunctions(SourceLocation StartLoc, SourceRange Range,
+                                   bool UseGlobal, QualType AllocType,
+                                   bool IsArray, Expr **PlaceArgs,
+                                   unsigned NumPlaceArgs,
+                                   FunctionDecl *&OperatorNew,
+                                   FunctionDecl *&OperatorDelete) {
+  // --- Choosing an allocation function ---
+  // C++ 5.3.4p8 - 14 & 18
+  // 1) If UseGlobal is true, only look in the global scope. Else, also look
+  //   in the scope of the allocated class.
+  // 2) If an array size is given, look for operator new[], else look for
+  //   operator new.
+  // 3) The first argument is always size_t. Append the arguments from the
+  //   placement form.
+  // FIXME: Also find the appropriate delete operator.
+
+  llvm::SmallVector<Expr*, 8> AllocArgs(1 + NumPlaceArgs);
+  // We don't care about the actual value of this argument.
+  // FIXME: Should the Sema create the expression and embed it in the syntax
+  // tree? Or should the consumer just recalculate the value?
+  IntegerLiteral Size(llvm::APInt::getNullValue(
+                      Context.Target.getPointerWidth(0)),
+                      Context.getSizeType(),
+                      SourceLocation());
+  AllocArgs[0] = &Size;
+  std::copy(PlaceArgs, PlaceArgs + NumPlaceArgs, AllocArgs.begin() + 1);
+
+  DeclarationName NewName = Context.DeclarationNames.getCXXOperatorName(
+                                        IsArray ? OO_Array_New : OO_New);
+  if (AllocType->isRecordType() && !UseGlobal) {
+    CXXRecordDecl *Record
+      = cast<CXXRecordDecl>(AllocType->getAs<RecordType>()->getDecl());
+    // FIXME: We fail to find inherited overloads.
+    if (FindAllocationOverload(StartLoc, Range, NewName, &AllocArgs[0],
+                          AllocArgs.size(), Record, /*AllowMissing=*/true,
+                          OperatorNew))
+      return true;
+  }
+  if (!OperatorNew) {
+    // Didn't find a member overload. Look for a global one.
+    DeclareGlobalNewDelete();
+    DeclContext *TUDecl = Context.getTranslationUnitDecl();
+    if (FindAllocationOverload(StartLoc, Range, NewName, &AllocArgs[0],
+                          AllocArgs.size(), TUDecl, /*AllowMissing=*/false,
+                          OperatorNew))
+      return true;
+  }
+
+  // FindAllocationOverload can change the passed in arguments, so we need to
+  // copy them back.
+  if (NumPlaceArgs > 0)
+    std::copy(&AllocArgs[1], AllocArgs.end(), PlaceArgs);
+
+  return false;
+}
+
+/// FindAllocationOverload - Find an fitting overload for the allocation
+/// function in the specified scope.
+bool Sema::FindAllocationOverload(SourceLocation StartLoc, SourceRange Range,
+                                  DeclarationName Name, Expr** Args,
+                                  unsigned NumArgs, DeclContext *Ctx,
+                                  bool AllowMissing, FunctionDecl *&Operator) {
+  LookupResult R(*this, Name, StartLoc, LookupOrdinaryName);
+  LookupQualifiedName(R, Ctx);
+  if (R.empty()) {
+    if (AllowMissing)
+      return false;
+    return Diag(StartLoc, diag::err_ovl_no_viable_function_in_call)
+      << Name << Range;
+  }
+
+  // FIXME: handle ambiguity
+
+  OverloadCandidateSet Candidates(StartLoc);
+  for (LookupResult::iterator Alloc = R.begin(), AllocEnd = R.end(); 
+       Alloc != AllocEnd; ++Alloc) {
+    // Even member operator new/delete are implicitly treated as
+    // static, so don't use AddMemberCandidate.
+
+    if (FunctionTemplateDecl *FnTemplate = 
+          dyn_cast<FunctionTemplateDecl>((*Alloc)->getUnderlyingDecl())) {
+      AddTemplateOverloadCandidate(FnTemplate, Alloc.getAccess(),
+                                   /*ExplicitTemplateArgs=*/0, Args, NumArgs,
+                                   Candidates,
+                                   /*SuppressUserConversions=*/false);
+      continue;
+    }
+
+    FunctionDecl *Fn = cast<FunctionDecl>((*Alloc)->getUnderlyingDecl());
+    AddOverloadCandidate(Fn, Alloc.getAccess(), Args, NumArgs, Candidates,
+                         /*SuppressUserConversions=*/false);
+  }
+
+  // Do the resolution.
+  OverloadCandidateSet::iterator Best;
+  switch(BestViableFunction(Candidates, StartLoc, Best)) {
+  case OR_Success: {
+    // Got one!
+    FunctionDecl *FnDecl = Best->Function;
+    // The first argument is size_t, and the first parameter must be size_t,
+    // too. This is checked on declaration and can be assumed. (It can't be
+    // asserted on, though, since invalid decls are left in there.)
+    // Whatch out for variadic allocator function.
+    unsigned NumArgsInFnDecl = FnDecl->getNumParams();
+    for (unsigned i = 0; (i < NumArgs && i < NumArgsInFnDecl); ++i) {
+      if (PerformCopyInitialization(Args[i],
+                                    FnDecl->getParamDecl(i)->getType(),
+                                    AA_Passing))
+        return true;
+    }
+    Operator = FnDecl;
+    return false;
+  }
+
+  case OR_No_Viable_Function:
+    Diag(StartLoc, diag::err_ovl_no_viable_function_in_call)
+      << Name << Range;
+    PrintOverloadCandidates(Candidates, OCD_AllCandidates, Args, NumArgs);
+    return true;
+
+  case OR_Ambiguous:
+    Diag(StartLoc, diag::err_ovl_ambiguous_call)
+      << Name << Range;
+    PrintOverloadCandidates(Candidates, OCD_ViableCandidates, Args, NumArgs);
+    return true;
+
+  case OR_Deleted:
+    Diag(StartLoc, diag::err_ovl_deleted_call)
+      << Best->Function->isDeleted()
+      << Name << Range;
+    PrintOverloadCandidates(Candidates, OCD_AllCandidates, Args, NumArgs);
+    return true;
+  }
+  assert(false && "Unreachable, bad result from BestViableFunction");
+  return true;
+}
+
+
+/// DeclareGlobalNewDelete - Declare the global forms of operator new and
+/// delete. These are:
+/// @code
+///   void* operator new(std::size_t) throw(std::bad_alloc);
+///   void* operator new[](std::size_t) throw(std::bad_alloc);
+///   void operator delete(void *) throw();
+///   void operator delete[](void *) throw();
+/// @endcode
+/// Note that the placement and nothrow forms of new are *not* implicitly
+/// declared. Their use requires including \<new\>.
+void Sema::DeclareGlobalNewDelete() {
+  if (GlobalNewDeleteDeclared)
+    return;
+  
+  // C++ [basic.std.dynamic]p2:
+  //   [...] The following allocation and deallocation functions (18.4) are 
+  //   implicitly declared in global scope in each translation unit of a 
+  //   program
+  //   
+  //     void* operator new(std::size_t) throw(std::bad_alloc);
+  //     void* operator new[](std::size_t) throw(std::bad_alloc); 
+  //     void  operator delete(void*) throw(); 
+  //     void  operator delete[](void*) throw();
+  //
+  //   These implicit declarations introduce only the function names operator 
+  //   new, operator new[], operator delete, operator delete[].
+  //
+  // Here, we need to refer to std::bad_alloc, so we will implicitly declare
+  // "std" or "bad_alloc" as necessary to form the exception specification.
+  // However, we do not make these implicit declarations visible to name
+  // lookup.
+  if (!StdNamespace) {
+    // The "std" namespace has not yet been defined, so build one implicitly.
+    StdNamespace = NamespaceDecl::Create(Context, 
+                                         Context.getTranslationUnitDecl(),
+                                         SourceLocation(),
+                                         &PP.getIdentifierTable().get("std"));
+    StdNamespace->setImplicit(true);
+  }
+  
+  if (!StdBadAlloc) {
+    // The "std::bad_alloc" class has not yet been declared, so build it
+    // implicitly.
+    StdBadAlloc = CXXRecordDecl::Create(Context, TagDecl::TK_class, 
+                                        StdNamespace, 
+                                        SourceLocation(), 
+                                      &PP.getIdentifierTable().get("bad_alloc"), 
+                                        SourceLocation(), 0);
+    StdBadAlloc->setImplicit(true);
+  }
+  
+  GlobalNewDeleteDeclared = true;
+
+  QualType VoidPtr = Context.getPointerType(Context.VoidTy);
+  QualType SizeT = Context.getSizeType();
+  bool AssumeSaneOperatorNew = getLangOptions().AssumeSaneOperatorNew;
+
+  DeclareGlobalAllocationFunction(
+      Context.DeclarationNames.getCXXOperatorName(OO_New),
+      VoidPtr, SizeT, AssumeSaneOperatorNew);
+  DeclareGlobalAllocationFunction(
+      Context.DeclarationNames.getCXXOperatorName(OO_Array_New),
+      VoidPtr, SizeT, AssumeSaneOperatorNew);
+  DeclareGlobalAllocationFunction(
+      Context.DeclarationNames.getCXXOperatorName(OO_Delete),
+      Context.VoidTy, VoidPtr);
+  DeclareGlobalAllocationFunction(
+      Context.DeclarationNames.getCXXOperatorName(OO_Array_Delete),
+      Context.VoidTy, VoidPtr);
+}
+
+/// DeclareGlobalAllocationFunction - Declares a single implicit global
+/// allocation function if it doesn't already exist.
+void Sema::DeclareGlobalAllocationFunction(DeclarationName Name,
+                                           QualType Return, QualType Argument,
+                                           bool AddMallocAttr) {
+  DeclContext *GlobalCtx = Context.getTranslationUnitDecl();
+
+  // Check if this function is already declared.
+  {
+    DeclContext::lookup_iterator Alloc, AllocEnd;
+    for (llvm::tie(Alloc, AllocEnd) = GlobalCtx->lookup(Name);
+         Alloc != AllocEnd; ++Alloc) {
+      // Only look at non-template functions, as it is the predefined,
+      // non-templated allocation function we are trying to declare here.
+      if (FunctionDecl *Func = dyn_cast<FunctionDecl>(*Alloc)) {
+        QualType InitialParamType =
+          Context.getCanonicalType(
+            Func->getParamDecl(0)->getType().getUnqualifiedType());
+        // FIXME: Do we need to check for default arguments here?
+        if (Func->getNumParams() == 1 && InitialParamType == Argument)
+          return;
+      }
+    }
+  }
+
+  QualType BadAllocType;
+  bool HasBadAllocExceptionSpec 
+    = (Name.getCXXOverloadedOperator() == OO_New ||
+       Name.getCXXOverloadedOperator() == OO_Array_New);
+  if (HasBadAllocExceptionSpec) {
+    assert(StdBadAlloc && "Must have std::bad_alloc declared");
+    BadAllocType = Context.getTypeDeclType(StdBadAlloc);
+  }
+  
+  QualType FnType = Context.getFunctionType(Return, &Argument, 1, false, 0,
+                                            true, false,
+                                            HasBadAllocExceptionSpec? 1 : 0,
+                                            &BadAllocType);
+  FunctionDecl *Alloc =
+    FunctionDecl::Create(Context, GlobalCtx, SourceLocation(), Name,
+                         FnType, /*TInfo=*/0, FunctionDecl::None, false, true);
+  Alloc->setImplicit();
+  
+  if (AddMallocAttr)
+    Alloc->addAttr(::new (Context) MallocAttr());
+  
+  ParmVarDecl *Param = ParmVarDecl::Create(Context, Alloc, SourceLocation(),
+                                           0, Argument, /*TInfo=*/0,
+                                           VarDecl::None, 0);
+  Alloc->setParams(Context, &Param, 1);
+
+  // FIXME: Also add this declaration to the IdentifierResolver, but
+  // make sure it is at the end of the chain to coincide with the
+  // global scope.
+  ((DeclContext *)TUScope->getEntity())->addDecl(Alloc);
+}
+
+bool Sema::FindDeallocationFunction(SourceLocation StartLoc, CXXRecordDecl *RD,
+                                    DeclarationName Name,
+                                    FunctionDecl* &Operator) {
+  LookupResult Found(*this, Name, StartLoc, LookupOrdinaryName);
+  // Try to find operator delete/operator delete[] in class scope.
+  LookupQualifiedName(Found, RD);
+  
+  if (Found.isAmbiguous())
+    return true;
+
+  for (LookupResult::iterator F = Found.begin(), FEnd = Found.end();
+       F != FEnd; ++F) {
+    if (CXXMethodDecl *Delete = dyn_cast<CXXMethodDecl>(*F))
+      if (Delete->isUsualDeallocationFunction()) {
+        Operator = Delete;
+        return false;
+      }
+  }
+
+  // We did find operator delete/operator delete[] declarations, but
+  // none of them were suitable.
+  if (!Found.empty()) {
+    Diag(StartLoc, diag::err_no_suitable_delete_member_function_found)
+      << Name << RD;
+        
+    for (LookupResult::iterator F = Found.begin(), FEnd = Found.end();
+         F != FEnd; ++F) {
+      Diag((*F)->getLocation(), 
+           diag::note_delete_member_function_declared_here)
+        << Name;
+    }
+
+    return true;
+  }
+
+  // Look for a global declaration.
+  DeclareGlobalNewDelete();
+  DeclContext *TUDecl = Context.getTranslationUnitDecl();
+  
+  CXXNullPtrLiteralExpr Null(Context.VoidPtrTy, SourceLocation());
+  Expr* DeallocArgs[1];
+  DeallocArgs[0] = &Null;
+  if (FindAllocationOverload(StartLoc, SourceRange(), Name,
+                             DeallocArgs, 1, TUDecl, /*AllowMissing=*/false,
+                             Operator))
+    return true;
+
+  assert(Operator && "Did not find a deallocation function!");
+  return false;
+}
+
+/// ActOnCXXDelete - Parsed a C++ 'delete' expression (C++ 5.3.5), as in:
+/// @code ::delete ptr; @endcode
+/// or
+/// @code delete [] ptr; @endcode
+Action::OwningExprResult
+Sema::ActOnCXXDelete(SourceLocation StartLoc, bool UseGlobal,
+                     bool ArrayForm, ExprArg Operand) {
+  // C++ [expr.delete]p1:
+  //   The operand shall have a pointer type, or a class type having a single
+  //   conversion function to a pointer type. The result has type void.
+  //
+  // DR599 amends "pointer type" to "pointer to object type" in both cases.
+
+  FunctionDecl *OperatorDelete = 0;
+
+  Expr *Ex = (Expr *)Operand.get();
+  if (!Ex->isTypeDependent()) {
+    QualType Type = Ex->getType();
+
+    if (const RecordType *Record = Type->getAs<RecordType>()) {
+      llvm::SmallVector<CXXConversionDecl *, 4> ObjectPtrConversions;
+      CXXRecordDecl *RD = cast<CXXRecordDecl>(Record->getDecl());
+      const UnresolvedSetImpl *Conversions = RD->getVisibleConversionFunctions();
+      
+      for (UnresolvedSetImpl::iterator I = Conversions->begin(),
+             E = Conversions->end(); I != E; ++I) {
+        // Skip over templated conversion functions; they aren't considered.
+        if (isa<FunctionTemplateDecl>(*I))
+          continue;
+        
+        CXXConversionDecl *Conv = cast<CXXConversionDecl>(*I);
+        
+        QualType ConvType = Conv->getConversionType().getNonReferenceType();
+        if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>())
+          if (ConvPtrType->getPointeeType()->isObjectType())
+            ObjectPtrConversions.push_back(Conv);
+      }
+      if (ObjectPtrConversions.size() == 1) {
+        // We have a single conversion to a pointer-to-object type. Perform
+        // that conversion.
+        Operand.release();
+        if (!PerformImplicitConversion(Ex, 
+                            ObjectPtrConversions.front()->getConversionType(), 
+                                      AA_Converting)) {
+          Operand = Owned(Ex);
+          Type = Ex->getType();
+        }
+      }
+      else if (ObjectPtrConversions.size() > 1) {
+        Diag(StartLoc, diag::err_ambiguous_delete_operand)
+              << Type << Ex->getSourceRange();
+        for (unsigned i= 0; i < ObjectPtrConversions.size(); i++) {
+          CXXConversionDecl *Conv = ObjectPtrConversions[i];
+          NoteOverloadCandidate(Conv);
+        }
+        return ExprError();
+      }
+    }
+
+    if (!Type->isPointerType())
+      return ExprError(Diag(StartLoc, diag::err_delete_operand)
+        << Type << Ex->getSourceRange());
+
+    QualType Pointee = Type->getAs<PointerType>()->getPointeeType();
+    if (Pointee->isFunctionType() || Pointee->isVoidType())
+      return ExprError(Diag(StartLoc, diag::err_delete_operand)
+        << Type << Ex->getSourceRange());
+    else if (!Pointee->isDependentType() &&
+             RequireCompleteType(StartLoc, Pointee,
+                                 PDiag(diag::warn_delete_incomplete)
+                                   << Ex->getSourceRange()))
+      return ExprError();
+
+    // C++ [expr.delete]p2:
+    //   [Note: a pointer to a const type can be the operand of a 
+    //   delete-expression; it is not necessary to cast away the constness 
+    //   (5.2.11) of the pointer expression before it is used as the operand 
+    //   of the delete-expression. ]
+    ImpCastExprToType(Ex, Context.getPointerType(Context.VoidTy), 
+                      CastExpr::CK_NoOp);
+    
+    // Update the operand.
+    Operand.take();
+    Operand = ExprArg(*this, Ex);
+    
+    DeclarationName DeleteName = Context.DeclarationNames.getCXXOperatorName(
+                                      ArrayForm ? OO_Array_Delete : OO_Delete);
+
+    if (const RecordType *RT = Pointee->getAs<RecordType>()) {
+      CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl());
+
+      if (!UseGlobal && 
+          FindDeallocationFunction(StartLoc, RD, DeleteName, OperatorDelete))
+        return ExprError();
+      
+      if (!RD->hasTrivialDestructor())
+        if (const CXXDestructorDecl *Dtor = RD->getDestructor(Context))
+          MarkDeclarationReferenced(StartLoc,
+                                    const_cast<CXXDestructorDecl*>(Dtor));
+    }
+    
+    if (!OperatorDelete) {
+      // Look for a global declaration.
+      DeclareGlobalNewDelete();
+      DeclContext *TUDecl = Context.getTranslationUnitDecl();
+      if (FindAllocationOverload(StartLoc, SourceRange(), DeleteName,
+                                 &Ex, 1, TUDecl, /*AllowMissing=*/false,
+                                 OperatorDelete))
+        return ExprError();
+    }
+
+    // FIXME: Check access and ambiguity of operator delete and destructor.
+  }
+
+  Operand.release();
+  return Owned(new (Context) CXXDeleteExpr(Context.VoidTy, UseGlobal, ArrayForm,
+                                           OperatorDelete, Ex, StartLoc));
+}
+
+/// \brief Check the use of the given variable as a C++ condition in an if,
+/// while, do-while, or switch statement.
+Action::OwningExprResult Sema::CheckConditionVariable(VarDecl *ConditionVar) {
+  QualType T = ConditionVar->getType();
+  
+  // C++ [stmt.select]p2:
+  //   The declarator shall not specify a function or an array.
+  if (T->isFunctionType())
+    return ExprError(Diag(ConditionVar->getLocation(), 
+                          diag::err_invalid_use_of_function_type)
+                       << ConditionVar->getSourceRange());
+  else if (T->isArrayType())
+    return ExprError(Diag(ConditionVar->getLocation(), 
+                          diag::err_invalid_use_of_array_type)
+                     << ConditionVar->getSourceRange());
+
+  return Owned(DeclRefExpr::Create(Context, 0, SourceRange(), ConditionVar,
+                                   ConditionVar->getLocation(), 
+                                ConditionVar->getType().getNonReferenceType()));
+}
+
+/// CheckCXXBooleanCondition - Returns true if a conversion to bool is invalid.
+bool Sema::CheckCXXBooleanCondition(Expr *&CondExpr) {
+  // C++ 6.4p4:
+  // The value of a condition that is an initialized declaration in a statement
+  // other than a switch statement is the value of the declared variable
+  // implicitly converted to type bool. If that conversion is ill-formed, the
+  // program is ill-formed.
+  // The value of a condition that is an expression is the value of the
+  // expression, implicitly converted to bool.
+  //
+  return PerformContextuallyConvertToBool(CondExpr);
+}
+
+/// Helper function to determine whether this is the (deprecated) C++
+/// conversion from a string literal to a pointer to non-const char or
+/// non-const wchar_t (for narrow and wide string literals,
+/// respectively).
+bool
+Sema::IsStringLiteralToNonConstPointerConversion(Expr *From, QualType ToType) {
+  // Look inside the implicit cast, if it exists.
+  if (ImplicitCastExpr *Cast = dyn_cast<ImplicitCastExpr>(From))
+    From = Cast->getSubExpr();
+
+  // A string literal (2.13.4) that is not a wide string literal can
+  // be converted to an rvalue of type "pointer to char"; a wide
+  // string literal can be converted to an rvalue of type "pointer
+  // to wchar_t" (C++ 4.2p2).
+  if (StringLiteral *StrLit = dyn_cast<StringLiteral>(From))
+    if (const PointerType *ToPtrType = ToType->getAs<PointerType>())
+      if (const BuiltinType *ToPointeeType
+          = ToPtrType->getPointeeType()->getAs<BuiltinType>()) {
+        // This conversion is considered only when there is an
+        // explicit appropriate pointer target type (C++ 4.2p2).
+        if (!ToPtrType->getPointeeType().hasQualifiers() &&
+            ((StrLit->isWide() && ToPointeeType->isWideCharType()) ||
+             (!StrLit->isWide() &&
+              (ToPointeeType->getKind() == BuiltinType::Char_U ||
+               ToPointeeType->getKind() == BuiltinType::Char_S))))
+          return true;
+      }
+
+  return false;
+}
+
+/// PerformImplicitConversion - Perform an implicit conversion of the
+/// expression From to the type ToType. Returns true if there was an
+/// error, false otherwise. The expression From is replaced with the
+/// converted expression. Flavor is the kind of conversion we're
+/// performing, used in the error message. If @p AllowExplicit,
+/// explicit user-defined conversions are permitted. @p Elidable should be true
+/// when called for copies which may be elided (C++ 12.8p15). C++0x overload
+/// resolution works differently in that case.
+bool
+Sema::PerformImplicitConversion(Expr *&From, QualType ToType,
+                                AssignmentAction Action, bool AllowExplicit,
+                                bool Elidable) {
+  ImplicitConversionSequence ICS;
+  return PerformImplicitConversion(From, ToType, Action, AllowExplicit, 
+                                   Elidable, ICS);
+}
+
+bool
+Sema::PerformImplicitConversion(Expr *&From, QualType ToType,
+                                AssignmentAction Action, bool AllowExplicit,
+                                bool Elidable,
+                                ImplicitConversionSequence& ICS) {
+  ICS.setBad();
+  ICS.Bad.init(BadConversionSequence::no_conversion, From, ToType);
+  if (Elidable && getLangOptions().CPlusPlus0x) {
+    ICS = TryImplicitConversion(From, ToType,
+                                /*SuppressUserConversions=*/false,
+                                AllowExplicit,
+                                /*ForceRValue=*/true,
+                                /*InOverloadResolution=*/false);
+  }
+  if (ICS.isBad()) {
+    ICS = TryImplicitConversion(From, ToType,
+                                /*SuppressUserConversions=*/false,
+                                AllowExplicit,
+                                /*ForceRValue=*/false,
+                                /*InOverloadResolution=*/false);
+  }
+  return PerformImplicitConversion(From, ToType, ICS, Action);
+}
+
+/// PerformImplicitConversion - Perform an implicit conversion of the
+/// expression From to the type ToType using the pre-computed implicit
+/// conversion sequence ICS. Returns true if there was an error, false
+/// otherwise. The expression From is replaced with the converted
+/// expression. Action is the kind of conversion we're performing,
+/// used in the error message.
+bool
+Sema::PerformImplicitConversion(Expr *&From, QualType ToType,
+                                const ImplicitConversionSequence &ICS,
+                                AssignmentAction Action, bool IgnoreBaseAccess) {
+  switch (ICS.getKind()) {
+  case ImplicitConversionSequence::StandardConversion:
+    if (PerformImplicitConversion(From, ToType, ICS.Standard, Action,
+                                  IgnoreBaseAccess))
+      return true;
+    break;
+
+  case ImplicitConversionSequence::UserDefinedConversion: {
+    
+      FunctionDecl *FD = ICS.UserDefined.ConversionFunction;
+      CastExpr::CastKind CastKind = CastExpr::CK_Unknown;
+      QualType BeforeToType;
+      if (const CXXConversionDecl *Conv = dyn_cast<CXXConversionDecl>(FD)) {
+        CastKind = CastExpr::CK_UserDefinedConversion;
+        
+        // If the user-defined conversion is specified by a conversion function,
+        // the initial standard conversion sequence converts the source type to
+        // the implicit object parameter of the conversion function.
+        BeforeToType = Context.getTagDeclType(Conv->getParent());
+      } else if (const CXXConstructorDecl *Ctor = 
+                  dyn_cast<CXXConstructorDecl>(FD)) {
+        CastKind = CastExpr::CK_ConstructorConversion;
+        // Do no conversion if dealing with ... for the first conversion.
+        if (!ICS.UserDefined.EllipsisConversion) {
+          // If the user-defined conversion is specified by a constructor, the 
+          // initial standard conversion sequence converts the source type to the
+          // type required by the argument of the constructor
+          BeforeToType = Ctor->getParamDecl(0)->getType().getNonReferenceType();
+        }
+      }    
+      else
+        assert(0 && "Unknown conversion function kind!");
+      // Whatch out for elipsis conversion.
+      if (!ICS.UserDefined.EllipsisConversion) {
+        if (PerformImplicitConversion(From, BeforeToType, 
+                                      ICS.UserDefined.Before, AA_Converting,
+                                      IgnoreBaseAccess))
+          return true;
+      }
+    
+      OwningExprResult CastArg 
+        = BuildCXXCastArgument(From->getLocStart(),
+                               ToType.getNonReferenceType(),
+                               CastKind, cast<CXXMethodDecl>(FD), 
+                               Owned(From));
+
+      if (CastArg.isInvalid())
+        return true;
+
+      From = CastArg.takeAs<Expr>();
+
+      return PerformImplicitConversion(From, ToType, ICS.UserDefined.After,
+                                       AA_Converting, IgnoreBaseAccess);
+  }
+
+  case ImplicitConversionSequence::AmbiguousConversion:
+    DiagnoseAmbiguousConversion(ICS, From->getExprLoc(),
+                          PDiag(diag::err_typecheck_ambiguous_condition)
+                            << From->getSourceRange());
+     return true;
+      
+  case ImplicitConversionSequence::EllipsisConversion:
+    assert(false && "Cannot perform an ellipsis conversion");
+    return false;
+
+  case ImplicitConversionSequence::BadConversion:
+    return true;
+  }
+
+  // Everything went well.
+  return false;
+}
+
+/// PerformImplicitConversion - Perform an implicit conversion of the
+/// expression From to the type ToType by following the standard
+/// conversion sequence SCS. Returns true if there was an error, false
+/// otherwise. The expression From is replaced with the converted
+/// expression. Flavor is the context in which we're performing this
+/// conversion, for use in error messages.
+bool
+Sema::PerformImplicitConversion(Expr *&From, QualType ToType,
+                                const StandardConversionSequence& SCS,
+                                AssignmentAction Action, bool IgnoreBaseAccess) {
+  // Overall FIXME: we are recomputing too many types here and doing far too
+  // much extra work. What this means is that we need to keep track of more
+  // information that is computed when we try the implicit conversion initially,
+  // so that we don't need to recompute anything here.
+  QualType FromType = From->getType();
+
+  if (SCS.CopyConstructor) {
+    // FIXME: When can ToType be a reference type?
+    assert(!ToType->isReferenceType());
+    if (SCS.Second == ICK_Derived_To_Base) {
+      ASTOwningVector<&ActionBase::DeleteExpr> ConstructorArgs(*this);
+      if (CompleteConstructorCall(cast<CXXConstructorDecl>(SCS.CopyConstructor),
+                                  MultiExprArg(*this, (void **)&From, 1),
+                                  /*FIXME:ConstructLoc*/SourceLocation(), 
+                                  ConstructorArgs))
+        return true;
+      OwningExprResult FromResult =
+        BuildCXXConstructExpr(/*FIXME:ConstructLoc*/SourceLocation(),
+                              ToType, SCS.CopyConstructor,
+                              move_arg(ConstructorArgs));
+      if (FromResult.isInvalid())
+        return true;
+      From = FromResult.takeAs<Expr>();
+      return false;
+    }
+    OwningExprResult FromResult =
+      BuildCXXConstructExpr(/*FIXME:ConstructLoc*/SourceLocation(),
+                            ToType, SCS.CopyConstructor,
+                            MultiExprArg(*this, (void**)&From, 1));
+
+    if (FromResult.isInvalid())
+      return true;
+
+    From = FromResult.takeAs<Expr>();
+    return false;
+  }
+
+  // Perform the first implicit conversion.
+  switch (SCS.First) {
+  case ICK_Identity:
+  case ICK_Lvalue_To_Rvalue:
+    // Nothing to do.
+    break;
+
+  case ICK_Array_To_Pointer:
+    FromType = Context.getArrayDecayedType(FromType);
+    ImpCastExprToType(From, FromType, CastExpr::CK_ArrayToPointerDecay);
+    break;
+
+  case ICK_Function_To_Pointer:
+    if (Context.getCanonicalType(FromType) == Context.OverloadTy) {
+      FunctionDecl *Fn = ResolveAddressOfOverloadedFunction(From, ToType, true);
+      if (!Fn)
+        return true;
+
+      if (DiagnoseUseOfDecl(Fn, From->getSourceRange().getBegin()))
+        return true;
+
+      From = FixOverloadedFunctionReference(From, Fn);
+      FromType = From->getType();
+        
+      // If there's already an address-of operator in the expression, we have
+      // the right type already, and the code below would just introduce an
+      // invalid additional pointer level.
+      if (FromType->isPointerType() || FromType->isMemberFunctionPointerType())
+        break;
+    }
+    FromType = Context.getPointerType(FromType);
+    ImpCastExprToType(From, FromType, CastExpr::CK_FunctionToPointerDecay);
+    break;
+
+  default:
+    assert(false && "Improper first standard conversion");
+    break;
+  }
+
+  // Perform the second implicit conversion
+  switch (SCS.Second) {
+  case ICK_Identity:
+    // If both sides are functions (or pointers/references to them), there could
+    // be incompatible exception declarations.
+    if (CheckExceptionSpecCompatibility(From, ToType))
+      return true;
+    // Nothing else to do.
+    break;
+
+  case ICK_NoReturn_Adjustment:
+    // If both sides are functions (or pointers/references to them), there could
+    // be incompatible exception declarations.
+    if (CheckExceptionSpecCompatibility(From, ToType))
+      return true;      
+      
+    ImpCastExprToType(From, Context.getNoReturnType(From->getType(), false),
+                      CastExpr::CK_NoOp);
+    break;
+      
+  case ICK_Integral_Promotion:
+  case ICK_Integral_Conversion:
+    ImpCastExprToType(From, ToType, CastExpr::CK_IntegralCast);
+    break;
+
+  case ICK_Floating_Promotion:
+  case ICK_Floating_Conversion:
+    ImpCastExprToType(From, ToType, CastExpr::CK_FloatingCast);
+    break;
+
+  case ICK_Complex_Promotion:
+  case ICK_Complex_Conversion:
+    ImpCastExprToType(From, ToType, CastExpr::CK_Unknown);
+    break;
+
+  case ICK_Floating_Integral:
+    if (ToType->isFloatingType())
+      ImpCastExprToType(From, ToType, CastExpr::CK_IntegralToFloating);
+    else
+      ImpCastExprToType(From, ToType, CastExpr::CK_FloatingToIntegral);
+    break;
+
+  case ICK_Complex_Real:
+    ImpCastExprToType(From, ToType, CastExpr::CK_Unknown);
+    break;
+
+  case ICK_Compatible_Conversion:
+    ImpCastExprToType(From, ToType, CastExpr::CK_NoOp);
+    break;
+
+  case ICK_Pointer_Conversion: {
+    if (SCS.IncompatibleObjC) {
+      // Diagnose incompatible Objective-C conversions
+      Diag(From->getSourceRange().getBegin(),
+           diag::ext_typecheck_convert_incompatible_pointer)
+        << From->getType() << ToType << Action
+        << From->getSourceRange();
+    }
+
+    
+    CastExpr::CastKind Kind = CastExpr::CK_Unknown;
+    if (CheckPointerConversion(From, ToType, Kind, IgnoreBaseAccess))
+      return true;
+    ImpCastExprToType(From, ToType, Kind);
+    break;
+  }
+  
+  case ICK_Pointer_Member: {
+    CastExpr::CastKind Kind = CastExpr::CK_Unknown;
+    if (CheckMemberPointerConversion(From, ToType, Kind, IgnoreBaseAccess))
+      return true;
+    if (CheckExceptionSpecCompatibility(From, ToType))
+      return true;
+    ImpCastExprToType(From, ToType, Kind);
+    break;
+  }
+  case ICK_Boolean_Conversion: {
+    CastExpr::CastKind Kind = CastExpr::CK_Unknown;
+    if (FromType->isMemberPointerType())
+      Kind = CastExpr::CK_MemberPointerToBoolean;
+    
+    ImpCastExprToType(From, Context.BoolTy, Kind);
+    break;
+  }
+
+  case ICK_Derived_To_Base:
+    if (CheckDerivedToBaseConversion(From->getType(), 
+                                     ToType.getNonReferenceType(),
+                                     From->getLocStart(),
+                                     From->getSourceRange(),
+                                     IgnoreBaseAccess))
+      return true;
+    ImpCastExprToType(From, ToType.getNonReferenceType(), 
+                      CastExpr::CK_DerivedToBase);
+    break;
+      
+  default:
+    assert(false && "Improper second standard conversion");
+    break;
+  }
+
+  switch (SCS.Third) {
+  case ICK_Identity:
+    // Nothing to do.
+    break;
+
+  case ICK_Qualification:
+    // FIXME: Not sure about lvalue vs rvalue here in the presence of rvalue
+    // references.
+    ImpCastExprToType(From, ToType.getNonReferenceType(),
+                      CastExpr::CK_NoOp,
+                      ToType->isLValueReferenceType());
+    break;
+      
+  default:
+    assert(false && "Improper second standard conversion");
+    break;
+  }
+
+  return false;
+}
+
+Sema::OwningExprResult Sema::ActOnUnaryTypeTrait(UnaryTypeTrait OTT,
+                                                 SourceLocation KWLoc,
+                                                 SourceLocation LParen,
+                                                 TypeTy *Ty,
+                                                 SourceLocation RParen) {
+  QualType T = GetTypeFromParser(Ty);
+
+  // According to http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html
+  // all traits except __is_class, __is_enum and __is_union require a the type
+  // to be complete.
+  if (OTT != UTT_IsClass && OTT != UTT_IsEnum && OTT != UTT_IsUnion) {
+    if (RequireCompleteType(KWLoc, T,
+                            diag::err_incomplete_type_used_in_type_trait_expr))
+      return ExprError();
+  }
+
+  // There is no point in eagerly computing the value. The traits are designed
+  // to be used from type trait templates, so Ty will be a template parameter
+  // 99% of the time.
+  return Owned(new (Context) UnaryTypeTraitExpr(KWLoc, OTT, T,
+                                                RParen, Context.BoolTy));
+}
+
+QualType Sema::CheckPointerToMemberOperands(
+  Expr *&lex, Expr *&rex, SourceLocation Loc, bool isIndirect) {
+  const char *OpSpelling = isIndirect ? "->*" : ".*";
+  // C++ 5.5p2
+  //   The binary operator .* [p3: ->*] binds its second operand, which shall
+  //   be of type "pointer to member of T" (where T is a completely-defined
+  //   class type) [...]
+  QualType RType = rex->getType();
+  const MemberPointerType *MemPtr = RType->getAs<MemberPointerType>();
+  if (!MemPtr) {
+    Diag(Loc, diag::err_bad_memptr_rhs)
+      << OpSpelling << RType << rex->getSourceRange();
+    return QualType();
+  }
+
+  QualType Class(MemPtr->getClass(), 0);
+
+  // C++ 5.5p2
+  //   [...] to its first operand, which shall be of class T or of a class of
+  //   which T is an unambiguous and accessible base class. [p3: a pointer to
+  //   such a class]
+  QualType LType = lex->getType();
+  if (isIndirect) {
+    if (const PointerType *Ptr = LType->getAs<PointerType>())
+      LType = Ptr->getPointeeType().getNonReferenceType();
+    else {
+      Diag(Loc, diag::err_bad_memptr_lhs)
+        << OpSpelling << 1 << LType
+        << CodeModificationHint::CreateReplacement(SourceRange(Loc), ".*");
+      return QualType();
+    }
+  }
+
+  if (!Context.hasSameUnqualifiedType(Class, LType)) {
+    CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/false,
+                       /*DetectVirtual=*/false);
+    // FIXME: Would it be useful to print full ambiguity paths, or is that
+    // overkill?
+    if (!IsDerivedFrom(LType, Class, Paths) ||
+        Paths.isAmbiguous(Context.getCanonicalType(Class))) {
+      Diag(Loc, diag::err_bad_memptr_lhs) << OpSpelling
+        << (int)isIndirect << lex->getType();
+      return QualType();
+    }
+    // Cast LHS to type of use.
+    QualType UseType = isIndirect ? Context.getPointerType(Class) : Class;
+    bool isLValue = !isIndirect && lex->isLvalue(Context) == Expr::LV_Valid;
+    ImpCastExprToType(lex, UseType, CastExpr::CK_DerivedToBase, isLValue);
+  }
+
+  if (isa<CXXZeroInitValueExpr>(rex->IgnoreParens())) {
+    // Diagnose use of pointer-to-member type which when used as
+    // the functional cast in a pointer-to-member expression.
+    Diag(Loc, diag::err_pointer_to_member_type) << isIndirect;
+     return QualType();
+  }
+  // C++ 5.5p2
+  //   The result is an object or a function of the type specified by the
+  //   second operand.
+  // The cv qualifiers are the union of those in the pointer and the left side,
+  // in accordance with 5.5p5 and 5.2.5.
+  // FIXME: This returns a dereferenced member function pointer as a normal
+  // function type. However, the only operation valid on such functions is
+  // calling them. There's also a GCC extension to get a function pointer to the
+  // thing, which is another complication, because this type - unlike the type
+  // that is the result of this expression - takes the class as the first
+  // argument.
+  // We probably need a "MemberFunctionClosureType" or something like that.
+  QualType Result = MemPtr->getPointeeType();
+  Result = Context.getCVRQualifiedType(Result, LType.getCVRQualifiers());
+  return Result;
+}
+
+/// \brief Get the target type of a standard or user-defined conversion.
+static QualType TargetType(const ImplicitConversionSequence &ICS) {
+  switch (ICS.getKind()) {
+  case ImplicitConversionSequence::StandardConversion:
+    return ICS.Standard.getToType(2);
+  case ImplicitConversionSequence::UserDefinedConversion:
+    return ICS.UserDefined.After.getToType(2);
+  case ImplicitConversionSequence::AmbiguousConversion:
+    return ICS.Ambiguous.getToType();
+  case ImplicitConversionSequence::EllipsisConversion:
+  case ImplicitConversionSequence::BadConversion:
+    llvm_unreachable("function not valid for ellipsis or bad conversions");
+  }
+  return QualType(); // silence warnings
+}
+
+/// \brief Try to convert a type to another according to C++0x 5.16p3.
+///
+/// This is part of the parameter validation for the ? operator. If either
+/// value operand is a class type, the two operands are attempted to be
+/// converted to each other. This function does the conversion in one direction.
+/// It emits a diagnostic and returns true only if it finds an ambiguous
+/// conversion.
+static bool TryClassUnification(Sema &Self, Expr *From, Expr *To,
+                                SourceLocation QuestionLoc,
+                                ImplicitConversionSequence &ICS) {
+  // C++0x 5.16p3
+  //   The process for determining whether an operand expression E1 of type T1
+  //   can be converted to match an operand expression E2 of type T2 is defined
+  //   as follows:
+  //   -- If E2 is an lvalue:
+  if (To->isLvalue(Self.Context) == Expr::LV_Valid) {
+    //   E1 can be converted to match E2 if E1 can be implicitly converted to
+    //   type "lvalue reference to T2", subject to the constraint that in the
+    //   conversion the reference must bind directly to E1.
+    if (!Self.CheckReferenceInit(From,
+                            Self.Context.getLValueReferenceType(To->getType()),
+                                 To->getLocStart(),
+                                 /*SuppressUserConversions=*/false,
+                                 /*AllowExplicit=*/false,
+                                 /*ForceRValue=*/false,
+                                 &ICS))
+    {
+      assert((ICS.isStandard() || ICS.isUserDefined()) &&
+             "expected a definite conversion");
+      bool DirectBinding =
+        ICS.isStandard() ? ICS.Standard.DirectBinding
+                         : ICS.UserDefined.After.DirectBinding;
+      if (DirectBinding)
+        return false;
+    }
+  }
+  ICS.setBad();
+  //   -- If E2 is an rvalue, or if the conversion above cannot be done:
+  //      -- if E1 and E2 have class type, and the underlying class types are
+  //         the same or one is a base class of the other:
+  QualType FTy = From->getType();
+  QualType TTy = To->getType();
+  const RecordType *FRec = FTy->getAs<RecordType>();
+  const RecordType *TRec = TTy->getAs<RecordType>();
+  bool FDerivedFromT = FRec && TRec && Self.IsDerivedFrom(FTy, TTy);
+  if (FRec && TRec && (FRec == TRec ||
+        FDerivedFromT || Self.IsDerivedFrom(TTy, FTy))) {
+    //         E1 can be converted to match E2 if the class of T2 is the
+    //         same type as, or a base class of, the class of T1, and
+    //         [cv2 > cv1].
+    if ((FRec == TRec || FDerivedFromT) && TTy.isAtLeastAsQualifiedAs(FTy)) {
+      // Could still fail if there's no copy constructor.
+      // FIXME: Is this a hard error then, or just a conversion failure? The
+      // standard doesn't say.
+      ICS = Self.TryCopyInitialization(From, TTy,
+                                       /*SuppressUserConversions=*/false,
+                                       /*ForceRValue=*/false,
+                                       /*InOverloadResolution=*/false);
+    }
+  } else {
+    //     -- Otherwise: E1 can be converted to match E2 if E1 can be
+    //        implicitly converted to the type that expression E2 would have
+    //        if E2 were converted to an rvalue.
+    // First find the decayed type.
+    if (TTy->isFunctionType())
+      TTy = Self.Context.getPointerType(TTy);
+    else if (TTy->isArrayType())
+      TTy = Self.Context.getArrayDecayedType(TTy);
+
+    // Now try the implicit conversion.
+    // FIXME: This doesn't detect ambiguities.
+    ICS = Self.TryImplicitConversion(From, TTy,
+                                     /*SuppressUserConversions=*/false,
+                                     /*AllowExplicit=*/false,
+                                     /*ForceRValue=*/false,
+                                     /*InOverloadResolution=*/false);
+  }
+  return false;
+}
+
+/// \brief Try to find a common type for two according to C++0x 5.16p5.
+///
+/// This is part of the parameter validation for the ? operator. If either
+/// value operand is a class type, overload resolution is used to find a
+/// conversion to a common type.
+static bool FindConditionalOverload(Sema &Self, Expr *&LHS, Expr *&RHS,
+                                    SourceLocation Loc) {
+  Expr *Args[2] = { LHS, RHS };
+  OverloadCandidateSet CandidateSet(Loc);
+  Self.AddBuiltinOperatorCandidates(OO_Conditional, Loc, Args, 2, CandidateSet);
+
+  OverloadCandidateSet::iterator Best;
+  switch (Self.BestViableFunction(CandidateSet, Loc, Best)) {
+    case OR_Success:
+      // We found a match. Perform the conversions on the arguments and move on.
+      if (Self.PerformImplicitConversion(LHS, Best->BuiltinTypes.ParamTypes[0],
+                                         Best->Conversions[0], Sema::AA_Converting) ||
+          Self.PerformImplicitConversion(RHS, Best->BuiltinTypes.ParamTypes[1],
+                                         Best->Conversions[1], Sema::AA_Converting))
+        break;
+      return false;
+
+    case OR_No_Viable_Function:
+      Self.Diag(Loc, diag::err_typecheck_cond_incompatible_operands)
+        << LHS->getType() << RHS->getType()
+        << LHS->getSourceRange() << RHS->getSourceRange();
+      return true;
+
+    case OR_Ambiguous:
+      Self.Diag(Loc, diag::err_conditional_ambiguous_ovl)
+        << LHS->getType() << RHS->getType()
+        << LHS->getSourceRange() << RHS->getSourceRange();
+      // FIXME: Print the possible common types by printing the return types of
+      // the viable candidates.
+      break;
+
+    case OR_Deleted:
+      assert(false && "Conditional operator has only built-in overloads");
+      break;
+  }
+  return true;
+}
+
+/// \brief Perform an "extended" implicit conversion as returned by
+/// TryClassUnification.
+///
+/// TryClassUnification generates ICSs that include reference bindings.
+/// PerformImplicitConversion is not suitable for this; it chokes if the
+/// second part of a standard conversion is ICK_DerivedToBase. This function
+/// handles the reference binding specially.
+static bool ConvertForConditional(Sema &Self, Expr *&E,
+                                  const ImplicitConversionSequence &ICS) {
+  if (ICS.isStandard() && ICS.Standard.ReferenceBinding) {
+    assert(ICS.Standard.DirectBinding &&
+           "TryClassUnification should never generate indirect ref bindings");
+    // FIXME: CheckReferenceInit should be able to reuse the ICS instead of
+    // redoing all the work.
+    return Self.CheckReferenceInit(E, Self.Context.getLValueReferenceType(
+                                        TargetType(ICS)),
+                                   /*FIXME:*/E->getLocStart(),
+                                   /*SuppressUserConversions=*/false,
+                                   /*AllowExplicit=*/false,
+                                   /*ForceRValue=*/false);
+  }
+  if (ICS.isUserDefined() && ICS.UserDefined.After.ReferenceBinding) {
+    assert(ICS.UserDefined.After.DirectBinding &&
+           "TryClassUnification should never generate indirect ref bindings");
+    return Self.CheckReferenceInit(E, Self.Context.getLValueReferenceType(
+                                        TargetType(ICS)),
+                                   /*FIXME:*/E->getLocStart(),
+                                   /*SuppressUserConversions=*/false,
+                                   /*AllowExplicit=*/false,
+                                   /*ForceRValue=*/false);
+  }
+  if (Self.PerformImplicitConversion(E, TargetType(ICS), ICS, Sema::AA_Converting))
+    return true;
+  return false;
+}
+
+/// \brief Check the operands of ?: under C++ semantics.
+///
+/// See C++ [expr.cond]. Note that LHS is never null, even for the GNU x ?: y
+/// extension. In this case, LHS == Cond. (But they're not aliases.)
+QualType Sema::CXXCheckConditionalOperands(Expr *&Cond, Expr *&LHS, Expr *&RHS,
+                                           SourceLocation QuestionLoc) {
+  // FIXME: Handle C99's complex types, vector types, block pointers and Obj-C++
+  // interface pointers.
+
+  // C++0x 5.16p1
+  //   The first expression is contextually converted to bool.
+  if (!Cond->isTypeDependent()) {
+    if (CheckCXXBooleanCondition(Cond))
+      return QualType();
+  }
+
+  // Either of the arguments dependent?
+  if (LHS->isTypeDependent() || RHS->isTypeDependent())
+    return Context.DependentTy;
+
+  CheckSignCompare(LHS, RHS, QuestionLoc, diag::warn_mixed_sign_conditional);
+
+  // C++0x 5.16p2
+  //   If either the second or the third operand has type (cv) void, ...
+  QualType LTy = LHS->getType();
+  QualType RTy = RHS->getType();
+  bool LVoid = LTy->isVoidType();
+  bool RVoid = RTy->isVoidType();
+  if (LVoid || RVoid) {
+    //   ... then the [l2r] conversions are performed on the second and third
+    //   operands ...
+    DefaultFunctionArrayLvalueConversion(LHS);
+    DefaultFunctionArrayLvalueConversion(RHS);
+    LTy = LHS->getType();
+    RTy = RHS->getType();
+
+    //   ... and one of the following shall hold:
+    //   -- The second or the third operand (but not both) is a throw-
+    //      expression; the result is of the type of the other and is an rvalue.
+    bool LThrow = isa<CXXThrowExpr>(LHS);
+    bool RThrow = isa<CXXThrowExpr>(RHS);
+    if (LThrow && !RThrow)
+      return RTy;
+    if (RThrow && !LThrow)
+      return LTy;
+
+    //   -- Both the second and third operands have type void; the result is of
+    //      type void and is an rvalue.
+    if (LVoid && RVoid)
+      return Context.VoidTy;
+
+    // Neither holds, error.
+    Diag(QuestionLoc, diag::err_conditional_void_nonvoid)
+      << (LVoid ? RTy : LTy) << (LVoid ? 0 : 1)
+      << LHS->getSourceRange() << RHS->getSourceRange();
+    return QualType();
+  }
+
+  // Neither is void.
+
+  // C++0x 5.16p3
+  //   Otherwise, if the second and third operand have different types, and
+  //   either has (cv) class type, and attempt is made to convert each of those
+  //   operands to the other.
+  if (Context.getCanonicalType(LTy) != Context.getCanonicalType(RTy) &&
+      (LTy->isRecordType() || RTy->isRecordType())) {
+    ImplicitConversionSequence ICSLeftToRight, ICSRightToLeft;
+    // These return true if a single direction is already ambiguous.
+    if (TryClassUnification(*this, LHS, RHS, QuestionLoc, ICSLeftToRight))
+      return QualType();
+    if (TryClassUnification(*this, RHS, LHS, QuestionLoc, ICSRightToLeft))
+      return QualType();
+
+    bool HaveL2R = !ICSLeftToRight.isBad();
+    bool HaveR2L = !ICSRightToLeft.isBad();
+    //   If both can be converted, [...] the program is ill-formed.
+    if (HaveL2R && HaveR2L) {
+      Diag(QuestionLoc, diag::err_conditional_ambiguous)
+        << LTy << RTy << LHS->getSourceRange() << RHS->getSourceRange();
+      return QualType();
+    }
+
+    //   If exactly one conversion is possible, that conversion is applied to
+    //   the chosen operand and the converted operands are used in place of the
+    //   original operands for the remainder of this section.
+    if (HaveL2R) {
+      if (ConvertForConditional(*this, LHS, ICSLeftToRight))
+        return QualType();
+      LTy = LHS->getType();
+    } else if (HaveR2L) {
+      if (ConvertForConditional(*this, RHS, ICSRightToLeft))
+        return QualType();
+      RTy = RHS->getType();
+    }
+  }
+
+  // C++0x 5.16p4
+  //   If the second and third operands are lvalues and have the same type,
+  //   the result is of that type [...]
+  bool Same = Context.getCanonicalType(LTy) == Context.getCanonicalType(RTy);
+  if (Same && LHS->isLvalue(Context) == Expr::LV_Valid &&
+      RHS->isLvalue(Context) == Expr::LV_Valid)
+    return LTy;
+
+  // C++0x 5.16p5
+  //   Otherwise, the result is an rvalue. If the second and third operands
+  //   do not have the same type, and either has (cv) class type, ...
+  if (!Same && (LTy->isRecordType() || RTy->isRecordType())) {
+    //   ... overload resolution is used to determine the conversions (if any)
+    //   to be applied to the operands. If the overload resolution fails, the
+    //   program is ill-formed.
+    if (FindConditionalOverload(*this, LHS, RHS, QuestionLoc))
+      return QualType();
+  }
+
+  // C++0x 5.16p6
+  //   LValue-to-rvalue, array-to-pointer, and function-to-pointer standard
+  //   conversions are performed on the second and third operands.
+  DefaultFunctionArrayLvalueConversion(LHS);
+  DefaultFunctionArrayLvalueConversion(RHS);
+  LTy = LHS->getType();
+  RTy = RHS->getType();
+
+  //   After those conversions, one of the following shall hold:
+  //   -- The second and third operands have the same type; the result
+  //      is of that type.
+  if (Context.getCanonicalType(LTy) == Context.getCanonicalType(RTy))
+    return LTy;
+
+  //   -- The second and third operands have arithmetic or enumeration type;
+  //      the usual arithmetic conversions are performed to bring them to a
+  //      common type, and the result is of that type.
+  if (LTy->isArithmeticType() && RTy->isArithmeticType()) {
+    UsualArithmeticConversions(LHS, RHS);
+    return LHS->getType();
+  }
+
+  //   -- The second and third operands have pointer type, or one has pointer
+  //      type and the other is a null pointer constant; pointer conversions
+  //      and qualification conversions are performed to bring them to their
+  //      composite pointer type. The result is of the composite pointer type.
+  //   -- The second and third operands have pointer to member type, or one has
+  //      pointer to member type and the other is a null pointer constant;
+  //      pointer to member conversions and qualification conversions are
+  //      performed to bring them to a common type, whose cv-qualification
+  //      shall match the cv-qualification of either the second or the third
+  //      operand. The result is of the common type.
+  QualType Composite = FindCompositePointerType(LHS, RHS);
+  if (!Composite.isNull())
+    return Composite;
+  
+  // Similarly, attempt to find composite type of twp objective-c pointers.
+  Composite = FindCompositeObjCPointerType(LHS, RHS, QuestionLoc);
+  if (!Composite.isNull())
+    return Composite;
+
+  Diag(QuestionLoc, diag::err_typecheck_cond_incompatible_operands)
+    << LHS->getType() << RHS->getType()
+    << LHS->getSourceRange() << RHS->getSourceRange();
+  return QualType();
+}
+
+/// \brief Find a merged pointer type and convert the two expressions to it.
+///
+/// This finds the composite pointer type (or member pointer type) for @p E1
+/// and @p E2 according to C++0x 5.9p2. It converts both expressions to this
+/// type and returns it.
+/// It does not emit diagnostics.
+QualType Sema::FindCompositePointerType(Expr *&E1, Expr *&E2) {
+  assert(getLangOptions().CPlusPlus && "This function assumes C++");
+  QualType T1 = E1->getType(), T2 = E2->getType();
+
+  if (!T1->isAnyPointerType() && !T1->isMemberPointerType() &&
+      !T2->isAnyPointerType() && !T2->isMemberPointerType())
+   return QualType();
+
+  // C++0x 5.9p2
+  //   Pointer conversions and qualification conversions are performed on
+  //   pointer operands to bring them to their composite pointer type. If
+  //   one operand is a null pointer constant, the composite pointer type is
+  //   the type of the other operand.
+  if (E1->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) {
+    if (T2->isMemberPointerType())
+      ImpCastExprToType(E1, T2, CastExpr::CK_NullToMemberPointer);
+    else
+      ImpCastExprToType(E1, T2, CastExpr::CK_IntegralToPointer);
+    return T2;
+  }
+  if (E2->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) {
+    if (T1->isMemberPointerType())
+      ImpCastExprToType(E2, T1, CastExpr::CK_NullToMemberPointer);
+    else
+      ImpCastExprToType(E2, T1, CastExpr::CK_IntegralToPointer);
+    return T1;
+  }
+
+  // Now both have to be pointers or member pointers.
+  if ((!T1->isPointerType() && !T1->isMemberPointerType()) ||
+      (!T2->isPointerType() && !T2->isMemberPointerType()))
+    return QualType();
+
+  //   Otherwise, of one of the operands has type "pointer to cv1 void," then
+  //   the other has type "pointer to cv2 T" and the composite pointer type is
+  //   "pointer to cv12 void," where cv12 is the union of cv1 and cv2.
+  //   Otherwise, the composite pointer type is a pointer type similar to the
+  //   type of one of the operands, with a cv-qualification signature that is
+  //   the union of the cv-qualification signatures of the operand types.
+  // In practice, the first part here is redundant; it's subsumed by the second.
+  // What we do here is, we build the two possible composite types, and try the
+  // conversions in both directions. If only one works, or if the two composite
+  // types are the same, we have succeeded.
+  // FIXME: extended qualifiers?
+  typedef llvm::SmallVector<unsigned, 4> QualifierVector;
+  QualifierVector QualifierUnion;
+  typedef llvm::SmallVector<std::pair<const Type *, const Type *>, 4>
+      ContainingClassVector;
+  ContainingClassVector MemberOfClass;
+  QualType Composite1 = Context.getCanonicalType(T1),
+           Composite2 = Context.getCanonicalType(T2);
+  do {
+    const PointerType *Ptr1, *Ptr2;
+    if ((Ptr1 = Composite1->getAs<PointerType>()) &&
+        (Ptr2 = Composite2->getAs<PointerType>())) {
+      Composite1 = Ptr1->getPointeeType();
+      Composite2 = Ptr2->getPointeeType();
+      QualifierUnion.push_back(
+                 Composite1.getCVRQualifiers() | Composite2.getCVRQualifiers());
+      MemberOfClass.push_back(std::make_pair((const Type *)0, (const Type *)0));
+      continue;
+    }
+
+    const MemberPointerType *MemPtr1, *MemPtr2;
+    if ((MemPtr1 = Composite1->getAs<MemberPointerType>()) &&
+        (MemPtr2 = Composite2->getAs<MemberPointerType>())) {
+      Composite1 = MemPtr1->getPointeeType();
+      Composite2 = MemPtr2->getPointeeType();
+      QualifierUnion.push_back(
+                 Composite1.getCVRQualifiers() | Composite2.getCVRQualifiers());
+      MemberOfClass.push_back(std::make_pair(MemPtr1->getClass(),
+                                             MemPtr2->getClass()));
+      continue;
+    }
+
+    // FIXME: block pointer types?
+
+    // Cannot unwrap any more types.
+    break;
+  } while (true);
+
+  // Rewrap the composites as pointers or member pointers with the union CVRs.
+  ContainingClassVector::reverse_iterator MOC
+    = MemberOfClass.rbegin();
+  for (QualifierVector::reverse_iterator
+         I = QualifierUnion.rbegin(),
+         E = QualifierUnion.rend();
+       I != E; (void)++I, ++MOC) {
+    Qualifiers Quals = Qualifiers::fromCVRMask(*I);
+    if (MOC->first && MOC->second) {
+      // Rebuild member pointer type
+      Composite1 = Context.getMemberPointerType(
+                                    Context.getQualifiedType(Composite1, Quals),
+                                    MOC->first);
+      Composite2 = Context.getMemberPointerType(
+                                    Context.getQualifiedType(Composite2, Quals),
+                                    MOC->second);
+    } else {
+      // Rebuild pointer type
+      Composite1
+        = Context.getPointerType(Context.getQualifiedType(Composite1, Quals));
+      Composite2
+        = Context.getPointerType(Context.getQualifiedType(Composite2, Quals));
+    }
+  }
+
+  ImplicitConversionSequence E1ToC1 =
+    TryImplicitConversion(E1, Composite1,
+                          /*SuppressUserConversions=*/false,
+                          /*AllowExplicit=*/false,
+                          /*ForceRValue=*/false,
+                          /*InOverloadResolution=*/false);
+  ImplicitConversionSequence E2ToC1 =
+    TryImplicitConversion(E2, Composite1,
+                          /*SuppressUserConversions=*/false,
+                          /*AllowExplicit=*/false,
+                          /*ForceRValue=*/false,
+                          /*InOverloadResolution=*/false);
+
+  ImplicitConversionSequence E1ToC2, E2ToC2;
+  E1ToC2.setBad();
+  E2ToC2.setBad();  
+  if (Context.getCanonicalType(Composite1) !=
+      Context.getCanonicalType(Composite2)) {
+    E1ToC2 = TryImplicitConversion(E1, Composite2,
+                                   /*SuppressUserConversions=*/false,
+                                   /*AllowExplicit=*/false,
+                                   /*ForceRValue=*/false,
+                                   /*InOverloadResolution=*/false);
+    E2ToC2 = TryImplicitConversion(E2, Composite2,
+                                   /*SuppressUserConversions=*/false,
+                                   /*AllowExplicit=*/false,
+                                   /*ForceRValue=*/false,
+                                   /*InOverloadResolution=*/false);
+  }
+
+  bool ToC1Viable = !E1ToC1.isBad() && !E2ToC1.isBad();
+  bool ToC2Viable = !E1ToC2.isBad() && !E2ToC2.isBad();
+  if (ToC1Viable && !ToC2Viable) {
+    if (!PerformImplicitConversion(E1, Composite1, E1ToC1, Sema::AA_Converting) &&
+        !PerformImplicitConversion(E2, Composite1, E2ToC1, Sema::AA_Converting))
+      return Composite1;
+  }
+  if (ToC2Viable && !ToC1Viable) {
+    if (!PerformImplicitConversion(E1, Composite2, E1ToC2, Sema::AA_Converting) &&
+        !PerformImplicitConversion(E2, Composite2, E2ToC2, Sema::AA_Converting))
+      return Composite2;
+  }
+  return QualType();
+}
+
+Sema::OwningExprResult Sema::MaybeBindToTemporary(Expr *E) {
+  if (!Context.getLangOptions().CPlusPlus)
+    return Owned(E);
+
+  assert(!isa<CXXBindTemporaryExpr>(E) && "Double-bound temporary?");
+
+  const RecordType *RT = E->getType()->getAs<RecordType>();
+  if (!RT)
+    return Owned(E);
+
+  // If this is the result of a call expression, our source might
+  // actually be a reference, in which case we shouldn't bind.
+  if (CallExpr *CE = dyn_cast<CallExpr>(E)) {
+    QualType Ty = CE->getCallee()->getType();
+    if (const PointerType *PT = Ty->getAs<PointerType>())
+      Ty = PT->getPointeeType();
+    
+    const FunctionType *FTy = Ty->getAs<FunctionType>();
+    if (FTy->getResultType()->isReferenceType())
+      return Owned(E);
+  }
+
+  // That should be enough to guarantee that this type is complete.
+  // If it has a trivial destructor, we can avoid the extra copy.
+  CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl());
+  if (RD->hasTrivialDestructor())
+    return Owned(E);
+
+  CXXTemporary *Temp = CXXTemporary::Create(Context,
+                                            RD->getDestructor(Context));
+  ExprTemporaries.push_back(Temp);
+  if (CXXDestructorDecl *Destructor =
+        const_cast<CXXDestructorDecl*>(RD->getDestructor(Context)))
+    MarkDeclarationReferenced(E->getExprLoc(), Destructor);
+  // FIXME: Add the temporary to the temporaries vector.
+  return Owned(CXXBindTemporaryExpr::Create(Context, Temp, E));
+}
+
+Expr *Sema::MaybeCreateCXXExprWithTemporaries(Expr *SubExpr) {
+  assert(SubExpr && "sub expression can't be null!");
+
+  unsigned FirstTemporary = ExprEvalContexts.back().NumTemporaries;
+  assert(ExprTemporaries.size() >= FirstTemporary);
+  if (ExprTemporaries.size() == FirstTemporary)
+    return SubExpr;
+
+  Expr *E = CXXExprWithTemporaries::Create(Context, SubExpr,
+                                           &ExprTemporaries[FirstTemporary],
+                                       ExprTemporaries.size() - FirstTemporary);
+  ExprTemporaries.erase(ExprTemporaries.begin() + FirstTemporary,
+                        ExprTemporaries.end());
+
+  return E;
+}
+
+Sema::OwningExprResult 
+Sema::MaybeCreateCXXExprWithTemporaries(OwningExprResult SubExpr) {
+  if (SubExpr.isInvalid())
+    return ExprError();
+  
+  return Owned(MaybeCreateCXXExprWithTemporaries(SubExpr.takeAs<Expr>()));
+}
+
+FullExpr Sema::CreateFullExpr(Expr *SubExpr) {
+  unsigned FirstTemporary = ExprEvalContexts.back().NumTemporaries;
+  assert(ExprTemporaries.size() >= FirstTemporary);
+  
+  unsigned NumTemporaries = ExprTemporaries.size() - FirstTemporary;
+  CXXTemporary **Temporaries = 
+    NumTemporaries == 0 ? 0 : &ExprTemporaries[FirstTemporary];
+  
+  FullExpr E = FullExpr::Create(Context, SubExpr, Temporaries, NumTemporaries);
+
+  ExprTemporaries.erase(ExprTemporaries.begin() + FirstTemporary,
+                        ExprTemporaries.end());
+
+  return E;
+}
+
+Sema::OwningExprResult
+Sema::ActOnStartCXXMemberReference(Scope *S, ExprArg Base, SourceLocation OpLoc,
+                                   tok::TokenKind OpKind, TypeTy *&ObjectType) {
+  // Since this might be a postfix expression, get rid of ParenListExprs.
+  Base = MaybeConvertParenListExprToParenExpr(S, move(Base));
+
+  Expr *BaseExpr = (Expr*)Base.get();
+  assert(BaseExpr && "no record expansion");
+
+  QualType BaseType = BaseExpr->getType();
+  if (BaseType->isDependentType()) {
+    // If we have a pointer to a dependent type and are using the -> operator,
+    // the object type is the type that the pointer points to. We might still
+    // have enough information about that type to do something useful.
+    if (OpKind == tok::arrow)
+      if (const PointerType *Ptr = BaseType->getAs<PointerType>())
+        BaseType = Ptr->getPointeeType();
+    
+    ObjectType = BaseType.getAsOpaquePtr();
+    return move(Base);
+  }
+
+  // C++ [over.match.oper]p8:
+  //   [...] When operator->returns, the operator-> is applied  to the value
+  //   returned, with the original second operand.
+  if (OpKind == tok::arrow) {
+    // The set of types we've considered so far.
+    llvm::SmallPtrSet<CanQualType,8> CTypes;
+    llvm::SmallVector<SourceLocation, 8> Locations;
+    CTypes.insert(Context.getCanonicalType(BaseType));
+    
+    while (BaseType->isRecordType()) {
+      Base = BuildOverloadedArrowExpr(S, move(Base), OpLoc);
+      BaseExpr = (Expr*)Base.get();
+      if (BaseExpr == NULL)
+        return ExprError();
+      if (CXXOperatorCallExpr *OpCall = dyn_cast<CXXOperatorCallExpr>(BaseExpr))
+        Locations.push_back(OpCall->getDirectCallee()->getLocation());
+      BaseType = BaseExpr->getType();
+      CanQualType CBaseType = Context.getCanonicalType(BaseType);
+      if (!CTypes.insert(CBaseType)) {
+        Diag(OpLoc, diag::err_operator_arrow_circular);
+        for (unsigned i = 0; i < Locations.size(); i++)
+          Diag(Locations[i], diag::note_declared_at);
+        return ExprError();
+      }
+    }
+
+    if (BaseType->isPointerType())
+      BaseType = BaseType->getPointeeType();
+  }
+
+  // We could end up with various non-record types here, such as extended
+  // vector types or Objective-C interfaces. Just return early and let
+  // ActOnMemberReferenceExpr do the work.
+  if (!BaseType->isRecordType()) {
+    // C++ [basic.lookup.classref]p2:
+    //   [...] If the type of the object expression is of pointer to scalar
+    //   type, the unqualified-id is looked up in the context of the complete
+    //   postfix-expression.
+    ObjectType = 0;
+    return move(Base);
+  }
+
+  // The object type must be complete (or dependent).
+  if (!BaseType->isDependentType() &&
+      RequireCompleteType(OpLoc, BaseType, 
+                          PDiag(diag::err_incomplete_member_access)))
+    return ExprError();
+  
+  // C++ [basic.lookup.classref]p2:
+  //   If the id-expression in a class member access (5.2.5) is an
+  //   unqualified-id, and the type of the object expression is of a class
+  //   type C (or of pointer to a class type C), the unqualified-id is looked
+  //   up in the scope of class C. [...]
+  ObjectType = BaseType.getAsOpaquePtr();
+  
+  return move(Base);
+}
+
+CXXMemberCallExpr *Sema::BuildCXXMemberCallExpr(Expr *Exp, 
+                                                CXXMethodDecl *Method) {
+  if (PerformObjectArgumentInitialization(Exp, Method))
+    assert(0 && "Calling BuildCXXMemberCallExpr with invalid call?");
+
+  MemberExpr *ME = 
+      new (Context) MemberExpr(Exp, /*IsArrow=*/false, Method, 
+                               SourceLocation(), Method->getType());
+  QualType ResultType = Method->getResultType().getNonReferenceType();
+  MarkDeclarationReferenced(Exp->getLocStart(), Method);
+  CXXMemberCallExpr *CE =
+    new (Context) CXXMemberCallExpr(Context, ME, 0, 0, ResultType,
+                                    Exp->getLocEnd());
+  return CE;
+}
+
+Sema::OwningExprResult Sema::BuildCXXCastArgument(SourceLocation CastLoc,
+                                                  QualType Ty,
+                                                  CastExpr::CastKind Kind,
+                                                  CXXMethodDecl *Method,
+                                                  ExprArg Arg) {
+  Expr *From = Arg.takeAs<Expr>();
+
+  switch (Kind) {
+  default: assert(0 && "Unhandled cast kind!");
+  case CastExpr::CK_ConstructorConversion: {
+    ASTOwningVector<&ActionBase::DeleteExpr> ConstructorArgs(*this);
+    
+    if (CompleteConstructorCall(cast<CXXConstructorDecl>(Method),
+                                MultiExprArg(*this, (void **)&From, 1),
+                                CastLoc, ConstructorArgs))
+      return ExprError();
+    
+    OwningExprResult Result = 
+      BuildCXXConstructExpr(CastLoc, Ty, cast<CXXConstructorDecl>(Method), 
+                            move_arg(ConstructorArgs));
+    if (Result.isInvalid())
+      return ExprError();
+    
+    return MaybeBindToTemporary(Result.takeAs<Expr>());
+  }
+
+  case CastExpr::CK_UserDefinedConversion: {
+    assert(!From->getType()->isPointerType() && "Arg can't have pointer type!");
+
+    // Create an implicit call expr that calls it.
+    CXXMemberCallExpr *CE = BuildCXXMemberCallExpr(From, Method);
+    return MaybeBindToTemporary(CE);
+  }
+  }
+}    
+
+Sema::OwningExprResult Sema::ActOnFinishFullExpr(ExprArg Arg) {
+  Expr *FullExpr = Arg.takeAs<Expr>();
+  if (FullExpr)
+    FullExpr = MaybeCreateCXXExprWithTemporaries(FullExpr);
+
+  return Owned(FullExpr);
+}