Check in LLVM r95781.
diff --git a/lib/Sema/SemaDeclCXX.cpp b/lib/Sema/SemaDeclCXX.cpp
new file mode 100644
index 0000000..b42a27c
--- /dev/null
+++ b/lib/Sema/SemaDeclCXX.cpp
@@ -0,0 +1,5842 @@
+//===------ SemaDeclCXX.cpp - Semantic Analysis for C++ Declarations ------===//
+//
+//                     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++ declarations.
+//
+//===----------------------------------------------------------------------===//
+
+#include "Sema.h"
+#include "SemaInit.h"
+#include "Lookup.h"
+#include "clang/AST/ASTConsumer.h"
+#include "clang/AST/ASTContext.h"
+#include "clang/AST/RecordLayout.h"
+#include "clang/AST/CXXInheritance.h"
+#include "clang/AST/DeclVisitor.h"
+#include "clang/AST/TypeLoc.h"
+#include "clang/AST/TypeOrdering.h"
+#include "clang/AST/StmtVisitor.h"
+#include "clang/Parse/DeclSpec.h"
+#include "clang/Parse/Template.h"
+#include "clang/Basic/PartialDiagnostic.h"
+#include "clang/Lex/Preprocessor.h"
+#include "llvm/ADT/STLExtras.h"
+#include <map>
+#include <set>
+
+using namespace clang;
+
+//===----------------------------------------------------------------------===//
+// CheckDefaultArgumentVisitor
+//===----------------------------------------------------------------------===//
+
+namespace {
+  /// CheckDefaultArgumentVisitor - C++ [dcl.fct.default] Traverses
+  /// the default argument of a parameter to determine whether it
+  /// contains any ill-formed subexpressions. For example, this will
+  /// diagnose the use of local variables or parameters within the
+  /// default argument expression.
+  class CheckDefaultArgumentVisitor
+    : public StmtVisitor<CheckDefaultArgumentVisitor, bool> {
+    Expr *DefaultArg;
+    Sema *S;
+
+  public:
+    CheckDefaultArgumentVisitor(Expr *defarg, Sema *s)
+      : DefaultArg(defarg), S(s) {}
+
+    bool VisitExpr(Expr *Node);
+    bool VisitDeclRefExpr(DeclRefExpr *DRE);
+    bool VisitCXXThisExpr(CXXThisExpr *ThisE);
+  };
+
+  /// VisitExpr - Visit all of the children of this expression.
+  bool CheckDefaultArgumentVisitor::VisitExpr(Expr *Node) {
+    bool IsInvalid = false;
+    for (Stmt::child_iterator I = Node->child_begin(),
+         E = Node->child_end(); I != E; ++I)
+      IsInvalid |= Visit(*I);
+    return IsInvalid;
+  }
+
+  /// VisitDeclRefExpr - Visit a reference to a declaration, to
+  /// determine whether this declaration can be used in the default
+  /// argument expression.
+  bool CheckDefaultArgumentVisitor::VisitDeclRefExpr(DeclRefExpr *DRE) {
+    NamedDecl *Decl = DRE->getDecl();
+    if (ParmVarDecl *Param = dyn_cast<ParmVarDecl>(Decl)) {
+      // C++ [dcl.fct.default]p9
+      //   Default arguments are evaluated each time the function is
+      //   called. The order of evaluation of function arguments is
+      //   unspecified. Consequently, parameters of a function shall not
+      //   be used in default argument expressions, even if they are not
+      //   evaluated. Parameters of a function declared before a default
+      //   argument expression are in scope and can hide namespace and
+      //   class member names.
+      return S->Diag(DRE->getSourceRange().getBegin(),
+                     diag::err_param_default_argument_references_param)
+         << Param->getDeclName() << DefaultArg->getSourceRange();
+    } else if (VarDecl *VDecl = dyn_cast<VarDecl>(Decl)) {
+      // C++ [dcl.fct.default]p7
+      //   Local variables shall not be used in default argument
+      //   expressions.
+      if (VDecl->isBlockVarDecl())
+        return S->Diag(DRE->getSourceRange().getBegin(),
+                       diag::err_param_default_argument_references_local)
+          << VDecl->getDeclName() << DefaultArg->getSourceRange();
+    }
+
+    return false;
+  }
+
+  /// VisitCXXThisExpr - Visit a C++ "this" expression.
+  bool CheckDefaultArgumentVisitor::VisitCXXThisExpr(CXXThisExpr *ThisE) {
+    // C++ [dcl.fct.default]p8:
+    //   The keyword this shall not be used in a default argument of a
+    //   member function.
+    return S->Diag(ThisE->getSourceRange().getBegin(),
+                   diag::err_param_default_argument_references_this)
+               << ThisE->getSourceRange();
+  }
+}
+
+bool
+Sema::SetParamDefaultArgument(ParmVarDecl *Param, ExprArg DefaultArg,
+                              SourceLocation EqualLoc) {
+  if (RequireCompleteType(Param->getLocation(), Param->getType(),
+                          diag::err_typecheck_decl_incomplete_type)) {
+    Param->setInvalidDecl();
+    return true;
+  }
+
+  Expr *Arg = (Expr *)DefaultArg.get();
+
+  // C++ [dcl.fct.default]p5
+  //   A default argument expression is implicitly converted (clause
+  //   4) to the parameter type. The default argument expression has
+  //   the same semantic constraints as the initializer expression in
+  //   a declaration of a variable of the parameter type, using the
+  //   copy-initialization semantics (8.5).
+  InitializedEntity Entity = InitializedEntity::InitializeParameter(Param);
+  InitializationKind Kind = InitializationKind::CreateCopy(Param->getLocation(),
+                                                           EqualLoc);
+  InitializationSequence InitSeq(*this, Entity, Kind, &Arg, 1);
+  OwningExprResult Result = InitSeq.Perform(*this, Entity, Kind,
+                                          MultiExprArg(*this, (void**)&Arg, 1));
+  if (Result.isInvalid())
+    return true;
+  Arg = Result.takeAs<Expr>();
+
+  Arg = MaybeCreateCXXExprWithTemporaries(Arg);
+
+  // Okay: add the default argument to the parameter
+  Param->setDefaultArg(Arg);
+
+  DefaultArg.release();
+
+  return false;
+}
+
+/// ActOnParamDefaultArgument - Check whether the default argument
+/// provided for a function parameter is well-formed. If so, attach it
+/// to the parameter declaration.
+void
+Sema::ActOnParamDefaultArgument(DeclPtrTy param, SourceLocation EqualLoc,
+                                ExprArg defarg) {
+  if (!param || !defarg.get())
+    return;
+
+  ParmVarDecl *Param = cast<ParmVarDecl>(param.getAs<Decl>());
+  UnparsedDefaultArgLocs.erase(Param);
+
+  ExprOwningPtr<Expr> DefaultArg(this, defarg.takeAs<Expr>());
+
+  // Default arguments are only permitted in C++
+  if (!getLangOptions().CPlusPlus) {
+    Diag(EqualLoc, diag::err_param_default_argument)
+      << DefaultArg->getSourceRange();
+    Param->setInvalidDecl();
+    return;
+  }
+
+  // Check that the default argument is well-formed
+  CheckDefaultArgumentVisitor DefaultArgChecker(DefaultArg.get(), this);
+  if (DefaultArgChecker.Visit(DefaultArg.get())) {
+    Param->setInvalidDecl();
+    return;
+  }
+
+  SetParamDefaultArgument(Param, move(DefaultArg), EqualLoc);
+}
+
+/// ActOnParamUnparsedDefaultArgument - We've seen a default
+/// argument for a function parameter, but we can't parse it yet
+/// because we're inside a class definition. Note that this default
+/// argument will be parsed later.
+void Sema::ActOnParamUnparsedDefaultArgument(DeclPtrTy param,
+                                             SourceLocation EqualLoc,
+                                             SourceLocation ArgLoc) {
+  if (!param)
+    return;
+
+  ParmVarDecl *Param = cast<ParmVarDecl>(param.getAs<Decl>());
+  if (Param)
+    Param->setUnparsedDefaultArg();
+
+  UnparsedDefaultArgLocs[Param] = ArgLoc;
+}
+
+/// ActOnParamDefaultArgumentError - Parsing or semantic analysis of
+/// the default argument for the parameter param failed.
+void Sema::ActOnParamDefaultArgumentError(DeclPtrTy param) {
+  if (!param)
+    return;
+
+  ParmVarDecl *Param = cast<ParmVarDecl>(param.getAs<Decl>());
+
+  Param->setInvalidDecl();
+
+  UnparsedDefaultArgLocs.erase(Param);
+}
+
+/// CheckExtraCXXDefaultArguments - Check for any extra default
+/// arguments in the declarator, which is not a function declaration
+/// or definition and therefore is not permitted to have default
+/// arguments. This routine should be invoked for every declarator
+/// that is not a function declaration or definition.
+void Sema::CheckExtraCXXDefaultArguments(Declarator &D) {
+  // C++ [dcl.fct.default]p3
+  //   A default argument expression shall be specified only in the
+  //   parameter-declaration-clause of a function declaration or in a
+  //   template-parameter (14.1). It shall not be specified for a
+  //   parameter pack. If it is specified in a
+  //   parameter-declaration-clause, it shall not occur within a
+  //   declarator or abstract-declarator of a parameter-declaration.
+  for (unsigned i = 0, e = D.getNumTypeObjects(); i != e; ++i) {
+    DeclaratorChunk &chunk = D.getTypeObject(i);
+    if (chunk.Kind == DeclaratorChunk::Function) {
+      for (unsigned argIdx = 0, e = chunk.Fun.NumArgs; argIdx != e; ++argIdx) {
+        ParmVarDecl *Param =
+          cast<ParmVarDecl>(chunk.Fun.ArgInfo[argIdx].Param.getAs<Decl>());
+        if (Param->hasUnparsedDefaultArg()) {
+          CachedTokens *Toks = chunk.Fun.ArgInfo[argIdx].DefaultArgTokens;
+          Diag(Param->getLocation(), diag::err_param_default_argument_nonfunc)
+            << SourceRange((*Toks)[1].getLocation(), Toks->back().getLocation());
+          delete Toks;
+          chunk.Fun.ArgInfo[argIdx].DefaultArgTokens = 0;
+        } else if (Param->getDefaultArg()) {
+          Diag(Param->getLocation(), diag::err_param_default_argument_nonfunc)
+            << Param->getDefaultArg()->getSourceRange();
+          Param->setDefaultArg(0);
+        }
+      }
+    }
+  }
+}
+
+// MergeCXXFunctionDecl - Merge two declarations of the same C++
+// function, once we already know that they have the same
+// type. Subroutine of MergeFunctionDecl. Returns true if there was an
+// error, false otherwise.
+bool Sema::MergeCXXFunctionDecl(FunctionDecl *New, FunctionDecl *Old) {
+  bool Invalid = false;
+
+  // C++ [dcl.fct.default]p4:
+  //   For non-template functions, default arguments can be added in
+  //   later declarations of a function in the same
+  //   scope. Declarations in different scopes have completely
+  //   distinct sets of default arguments. That is, declarations in
+  //   inner scopes do not acquire default arguments from
+  //   declarations in outer scopes, and vice versa. In a given
+  //   function declaration, all parameters subsequent to a
+  //   parameter with a default argument shall have default
+  //   arguments supplied in this or previous declarations. A
+  //   default argument shall not be redefined by a later
+  //   declaration (not even to the same value).
+  //
+  // C++ [dcl.fct.default]p6:
+  //   Except for member functions of class templates, the default arguments 
+  //   in a member function definition that appears outside of the class 
+  //   definition are added to the set of default arguments provided by the 
+  //   member function declaration in the class definition.
+  for (unsigned p = 0, NumParams = Old->getNumParams(); p < NumParams; ++p) {
+    ParmVarDecl *OldParam = Old->getParamDecl(p);
+    ParmVarDecl *NewParam = New->getParamDecl(p);
+
+    if (OldParam->hasDefaultArg() && NewParam->hasDefaultArg()) {
+      // FIXME: If we knew where the '=' was, we could easily provide a fix-it 
+      // hint here. Alternatively, we could walk the type-source information
+      // for NewParam to find the last source location in the type... but it
+      // isn't worth the effort right now. This is the kind of test case that
+      // is hard to get right:
+      
+      //   int f(int);
+      //   void g(int (*fp)(int) = f);
+      //   void g(int (*fp)(int) = &f);
+      Diag(NewParam->getLocation(),
+           diag::err_param_default_argument_redefinition)
+        << NewParam->getDefaultArgRange();
+      
+      // Look for the function declaration where the default argument was
+      // actually written, which may be a declaration prior to Old.
+      for (FunctionDecl *Older = Old->getPreviousDeclaration();
+           Older; Older = Older->getPreviousDeclaration()) {
+        if (!Older->getParamDecl(p)->hasDefaultArg())
+          break;
+        
+        OldParam = Older->getParamDecl(p);
+      }        
+      
+      Diag(OldParam->getLocation(), diag::note_previous_definition)
+        << OldParam->getDefaultArgRange();
+      Invalid = true;
+    } else if (OldParam->hasDefaultArg()) {
+      // Merge the old default argument into the new parameter
+      if (OldParam->hasUninstantiatedDefaultArg())
+        NewParam->setUninstantiatedDefaultArg(
+                                      OldParam->getUninstantiatedDefaultArg());
+      else
+        NewParam->setDefaultArg(OldParam->getDefaultArg());
+    } else if (NewParam->hasDefaultArg()) {
+      if (New->getDescribedFunctionTemplate()) {
+        // Paragraph 4, quoted above, only applies to non-template functions.
+        Diag(NewParam->getLocation(),
+             diag::err_param_default_argument_template_redecl)
+          << NewParam->getDefaultArgRange();
+        Diag(Old->getLocation(), diag::note_template_prev_declaration)
+          << false;
+      } else if (New->getTemplateSpecializationKind()
+                   != TSK_ImplicitInstantiation &&
+                 New->getTemplateSpecializationKind() != TSK_Undeclared) {
+        // C++ [temp.expr.spec]p21:
+        //   Default function arguments shall not be specified in a declaration
+        //   or a definition for one of the following explicit specializations:
+        //     - the explicit specialization of a function template;
+        //     - the explicit specialization of a member function template;
+        //     - the explicit specialization of a member function of a class 
+        //       template where the class template specialization to which the
+        //       member function specialization belongs is implicitly 
+        //       instantiated.
+        Diag(NewParam->getLocation(), diag::err_template_spec_default_arg)
+          << (New->getTemplateSpecializationKind() ==TSK_ExplicitSpecialization)
+          << New->getDeclName()
+          << NewParam->getDefaultArgRange();
+      } else if (New->getDeclContext()->isDependentContext()) {
+        // C++ [dcl.fct.default]p6 (DR217):
+        //   Default arguments for a member function of a class template shall 
+        //   be specified on the initial declaration of the member function 
+        //   within the class template.
+        //
+        // Reading the tea leaves a bit in DR217 and its reference to DR205 
+        // leads me to the conclusion that one cannot add default function 
+        // arguments for an out-of-line definition of a member function of a 
+        // dependent type.
+        int WhichKind = 2;
+        if (CXXRecordDecl *Record 
+              = dyn_cast<CXXRecordDecl>(New->getDeclContext())) {
+          if (Record->getDescribedClassTemplate())
+            WhichKind = 0;
+          else if (isa<ClassTemplatePartialSpecializationDecl>(Record))
+            WhichKind = 1;
+          else
+            WhichKind = 2;
+        }
+        
+        Diag(NewParam->getLocation(), 
+             diag::err_param_default_argument_member_template_redecl)
+          << WhichKind
+          << NewParam->getDefaultArgRange();
+      }
+    }
+  }
+
+  if (CheckEquivalentExceptionSpec(
+          Old->getType()->getAs<FunctionProtoType>(), Old->getLocation(),
+          New->getType()->getAs<FunctionProtoType>(), New->getLocation()))
+    Invalid = true;
+
+  return Invalid;
+}
+
+/// CheckCXXDefaultArguments - Verify that the default arguments for a
+/// function declaration are well-formed according to C++
+/// [dcl.fct.default].
+void Sema::CheckCXXDefaultArguments(FunctionDecl *FD) {
+  unsigned NumParams = FD->getNumParams();
+  unsigned p;
+
+  // Find first parameter with a default argument
+  for (p = 0; p < NumParams; ++p) {
+    ParmVarDecl *Param = FD->getParamDecl(p);
+    if (Param->hasDefaultArg())
+      break;
+  }
+
+  // C++ [dcl.fct.default]p4:
+  //   In a given function declaration, all parameters
+  //   subsequent to a parameter with a default argument shall
+  //   have default arguments supplied in this or previous
+  //   declarations. A default argument shall not be redefined
+  //   by a later declaration (not even to the same value).
+  unsigned LastMissingDefaultArg = 0;
+  for (; p < NumParams; ++p) {
+    ParmVarDecl *Param = FD->getParamDecl(p);
+    if (!Param->hasDefaultArg()) {
+      if (Param->isInvalidDecl())
+        /* We already complained about this parameter. */;
+      else if (Param->getIdentifier())
+        Diag(Param->getLocation(),
+             diag::err_param_default_argument_missing_name)
+          << Param->getIdentifier();
+      else
+        Diag(Param->getLocation(),
+             diag::err_param_default_argument_missing);
+
+      LastMissingDefaultArg = p;
+    }
+  }
+
+  if (LastMissingDefaultArg > 0) {
+    // Some default arguments were missing. Clear out all of the
+    // default arguments up to (and including) the last missing
+    // default argument, so that we leave the function parameters
+    // in a semantically valid state.
+    for (p = 0; p <= LastMissingDefaultArg; ++p) {
+      ParmVarDecl *Param = FD->getParamDecl(p);
+      if (Param->hasDefaultArg()) {
+        if (!Param->hasUnparsedDefaultArg())
+          Param->getDefaultArg()->Destroy(Context);
+        Param->setDefaultArg(0);
+      }
+    }
+  }
+}
+
+/// isCurrentClassName - Determine whether the identifier II is the
+/// name of the class type currently being defined. In the case of
+/// nested classes, this will only return true if II is the name of
+/// the innermost class.
+bool Sema::isCurrentClassName(const IdentifierInfo &II, Scope *,
+                              const CXXScopeSpec *SS) {
+  assert(getLangOptions().CPlusPlus && "No class names in C!");
+
+  CXXRecordDecl *CurDecl;
+  if (SS && SS->isSet() && !SS->isInvalid()) {
+    DeclContext *DC = computeDeclContext(*SS, true);
+    CurDecl = dyn_cast_or_null<CXXRecordDecl>(DC);
+  } else
+    CurDecl = dyn_cast_or_null<CXXRecordDecl>(CurContext);
+
+  if (CurDecl && CurDecl->getIdentifier())
+    return &II == CurDecl->getIdentifier();
+  else
+    return false;
+}
+
+/// \brief Check the validity of a C++ base class specifier.
+///
+/// \returns a new CXXBaseSpecifier if well-formed, emits diagnostics
+/// and returns NULL otherwise.
+CXXBaseSpecifier *
+Sema::CheckBaseSpecifier(CXXRecordDecl *Class,
+                         SourceRange SpecifierRange,
+                         bool Virtual, AccessSpecifier Access,
+                         QualType BaseType,
+                         SourceLocation BaseLoc) {
+  // C++ [class.union]p1:
+  //   A union shall not have base classes.
+  if (Class->isUnion()) {
+    Diag(Class->getLocation(), diag::err_base_clause_on_union)
+      << SpecifierRange;
+    return 0;
+  }
+
+  if (BaseType->isDependentType())
+    return new (Context) CXXBaseSpecifier(SpecifierRange, Virtual,
+                                Class->getTagKind() == RecordDecl::TK_class,
+                                Access, BaseType);
+
+  // Base specifiers must be record types.
+  if (!BaseType->isRecordType()) {
+    Diag(BaseLoc, diag::err_base_must_be_class) << SpecifierRange;
+    return 0;
+  }
+
+  // C++ [class.union]p1:
+  //   A union shall not be used as a base class.
+  if (BaseType->isUnionType()) {
+    Diag(BaseLoc, diag::err_union_as_base_class) << SpecifierRange;
+    return 0;
+  }
+
+  // C++ [class.derived]p2:
+  //   The class-name in a base-specifier shall not be an incompletely
+  //   defined class.
+  if (RequireCompleteType(BaseLoc, BaseType,
+                          PDiag(diag::err_incomplete_base_class)
+                            << SpecifierRange))
+    return 0;
+
+  // If the base class is polymorphic or isn't empty, the new one is/isn't, too.
+  RecordDecl *BaseDecl = BaseType->getAs<RecordType>()->getDecl();
+  assert(BaseDecl && "Record type has no declaration");
+  BaseDecl = BaseDecl->getDefinition(Context);
+  assert(BaseDecl && "Base type is not incomplete, but has no definition");
+  CXXRecordDecl * CXXBaseDecl = cast<CXXRecordDecl>(BaseDecl);
+  assert(CXXBaseDecl && "Base type is not a C++ type");
+
+  // C++0x CWG Issue #817 indicates that [[final]] classes shouldn't be bases.
+  if (CXXBaseDecl->hasAttr<FinalAttr>()) {
+    Diag(BaseLoc, diag::err_final_base) << BaseType.getAsString();
+    Diag(CXXBaseDecl->getLocation(), diag::note_previous_decl)
+      << BaseType;
+    return 0;
+  }
+
+  SetClassDeclAttributesFromBase(Class, CXXBaseDecl, Virtual);
+  
+  // Create the base specifier.
+  // FIXME: Allocate via ASTContext?
+  return new (Context) CXXBaseSpecifier(SpecifierRange, Virtual,
+                              Class->getTagKind() == RecordDecl::TK_class,
+                              Access, BaseType);
+}
+
+void Sema::SetClassDeclAttributesFromBase(CXXRecordDecl *Class,
+                                          const CXXRecordDecl *BaseClass,
+                                          bool BaseIsVirtual) {
+  // A class with a non-empty base class is not empty.
+  // FIXME: Standard ref?
+  if (!BaseClass->isEmpty())
+    Class->setEmpty(false);
+
+  // C++ [class.virtual]p1:
+  //   A class that [...] inherits a virtual function is called a polymorphic
+  //   class.
+  if (BaseClass->isPolymorphic())
+    Class->setPolymorphic(true);
+
+  // C++ [dcl.init.aggr]p1:
+  //   An aggregate is [...] a class with [...] no base classes [...].
+  Class->setAggregate(false);
+
+  // C++ [class]p4:
+  //   A POD-struct is an aggregate class...
+  Class->setPOD(false);
+
+  if (BaseIsVirtual) {
+    // C++ [class.ctor]p5:
+    //   A constructor is trivial if its class has no virtual base classes.
+    Class->setHasTrivialConstructor(false);
+
+    // C++ [class.copy]p6:
+    //   A copy constructor is trivial if its class has no virtual base classes.
+    Class->setHasTrivialCopyConstructor(false);
+
+    // C++ [class.copy]p11:
+    //   A copy assignment operator is trivial if its class has no virtual
+    //   base classes.
+    Class->setHasTrivialCopyAssignment(false);
+
+    // C++0x [meta.unary.prop] is_empty:
+    //    T is a class type, but not a union type, with ... no virtual base
+    //    classes
+    Class->setEmpty(false);
+  } else {
+    // C++ [class.ctor]p5:
+    //   A constructor is trivial if all the direct base classes of its
+    //   class have trivial constructors.
+    if (!BaseClass->hasTrivialConstructor())
+      Class->setHasTrivialConstructor(false);
+
+    // C++ [class.copy]p6:
+    //   A copy constructor is trivial if all the direct base classes of its
+    //   class have trivial copy constructors.
+    if (!BaseClass->hasTrivialCopyConstructor())
+      Class->setHasTrivialCopyConstructor(false);
+
+    // C++ [class.copy]p11:
+    //   A copy assignment operator is trivial if all the direct base classes
+    //   of its class have trivial copy assignment operators.
+    if (!BaseClass->hasTrivialCopyAssignment())
+      Class->setHasTrivialCopyAssignment(false);
+  }
+
+  // C++ [class.ctor]p3:
+  //   A destructor is trivial if all the direct base classes of its class
+  //   have trivial destructors.
+  if (!BaseClass->hasTrivialDestructor())
+    Class->setHasTrivialDestructor(false);
+}
+
+/// ActOnBaseSpecifier - Parsed a base specifier. A base specifier is
+/// one entry in the base class list of a class specifier, for
+/// example:
+///    class foo : public bar, virtual private baz {
+/// 'public bar' and 'virtual private baz' are each base-specifiers.
+Sema::BaseResult
+Sema::ActOnBaseSpecifier(DeclPtrTy classdecl, SourceRange SpecifierRange,
+                         bool Virtual, AccessSpecifier Access,
+                         TypeTy *basetype, SourceLocation BaseLoc) {
+  if (!classdecl)
+    return true;
+
+  AdjustDeclIfTemplate(classdecl);
+  CXXRecordDecl *Class = cast<CXXRecordDecl>(classdecl.getAs<Decl>());
+  QualType BaseType = GetTypeFromParser(basetype);
+  if (CXXBaseSpecifier *BaseSpec = CheckBaseSpecifier(Class, SpecifierRange,
+                                                      Virtual, Access,
+                                                      BaseType, BaseLoc))
+    return BaseSpec;
+
+  return true;
+}
+
+/// \brief Performs the actual work of attaching the given base class
+/// specifiers to a C++ class.
+bool Sema::AttachBaseSpecifiers(CXXRecordDecl *Class, CXXBaseSpecifier **Bases,
+                                unsigned NumBases) {
+ if (NumBases == 0)
+    return false;
+
+  // Used to keep track of which base types we have already seen, so
+  // that we can properly diagnose redundant direct base types. Note
+  // that the key is always the unqualified canonical type of the base
+  // class.
+  std::map<QualType, CXXBaseSpecifier*, QualTypeOrdering> KnownBaseTypes;
+
+  // Copy non-redundant base specifiers into permanent storage.
+  unsigned NumGoodBases = 0;
+  bool Invalid = false;
+  for (unsigned idx = 0; idx < NumBases; ++idx) {
+    QualType NewBaseType
+      = Context.getCanonicalType(Bases[idx]->getType());
+    NewBaseType = NewBaseType.getLocalUnqualifiedType();
+
+    if (KnownBaseTypes[NewBaseType]) {
+      // C++ [class.mi]p3:
+      //   A class shall not be specified as a direct base class of a
+      //   derived class more than once.
+      Diag(Bases[idx]->getSourceRange().getBegin(),
+           diag::err_duplicate_base_class)
+        << KnownBaseTypes[NewBaseType]->getType()
+        << Bases[idx]->getSourceRange();
+
+      // Delete the duplicate base class specifier; we're going to
+      // overwrite its pointer later.
+      Context.Deallocate(Bases[idx]);
+
+      Invalid = true;
+    } else {
+      // Okay, add this new base class.
+      KnownBaseTypes[NewBaseType] = Bases[idx];
+      Bases[NumGoodBases++] = Bases[idx];
+    }
+  }
+
+  // Attach the remaining base class specifiers to the derived class.
+  Class->setBases(Context, Bases, NumGoodBases);
+
+  // Delete the remaining (good) base class specifiers, since their
+  // data has been copied into the CXXRecordDecl.
+  for (unsigned idx = 0; idx < NumGoodBases; ++idx)
+    Context.Deallocate(Bases[idx]);
+
+  return Invalid;
+}
+
+/// ActOnBaseSpecifiers - Attach the given base specifiers to the
+/// class, after checking whether there are any duplicate base
+/// classes.
+void Sema::ActOnBaseSpecifiers(DeclPtrTy ClassDecl, BaseTy **Bases,
+                               unsigned NumBases) {
+  if (!ClassDecl || !Bases || !NumBases)
+    return;
+
+  AdjustDeclIfTemplate(ClassDecl);
+  AttachBaseSpecifiers(cast<CXXRecordDecl>(ClassDecl.getAs<Decl>()),
+                       (CXXBaseSpecifier**)(Bases), NumBases);
+}
+
+/// \brief Determine whether the type \p Derived is a C++ class that is
+/// derived from the type \p Base.
+bool Sema::IsDerivedFrom(QualType Derived, QualType Base) {
+  if (!getLangOptions().CPlusPlus)
+    return false;
+    
+  const RecordType *DerivedRT = Derived->getAs<RecordType>();
+  if (!DerivedRT)
+    return false;
+  
+  const RecordType *BaseRT = Base->getAs<RecordType>();
+  if (!BaseRT)
+    return false;
+  
+  CXXRecordDecl *DerivedRD = cast<CXXRecordDecl>(DerivedRT->getDecl());
+  CXXRecordDecl *BaseRD = cast<CXXRecordDecl>(BaseRT->getDecl());
+  // FIXME: instantiate DerivedRD if necessary.  We need a PoI for this.
+  return DerivedRD->hasDefinition() && DerivedRD->isDerivedFrom(BaseRD);
+}
+
+/// \brief Determine whether the type \p Derived is a C++ class that is
+/// derived from the type \p Base.
+bool Sema::IsDerivedFrom(QualType Derived, QualType Base, CXXBasePaths &Paths) {
+  if (!getLangOptions().CPlusPlus)
+    return false;
+  
+  const RecordType *DerivedRT = Derived->getAs<RecordType>();
+  if (!DerivedRT)
+    return false;
+  
+  const RecordType *BaseRT = Base->getAs<RecordType>();
+  if (!BaseRT)
+    return false;
+  
+  CXXRecordDecl *DerivedRD = cast<CXXRecordDecl>(DerivedRT->getDecl());
+  CXXRecordDecl *BaseRD = cast<CXXRecordDecl>(BaseRT->getDecl());
+  return DerivedRD->isDerivedFrom(BaseRD, Paths);
+}
+
+/// CheckDerivedToBaseConversion - Check whether the Derived-to-Base
+/// conversion (where Derived and Base are class types) is
+/// well-formed, meaning that the conversion is unambiguous (and
+/// that all of the base classes are accessible). Returns true
+/// and emits a diagnostic if the code is ill-formed, returns false
+/// otherwise. Loc is the location where this routine should point to
+/// if there is an error, and Range is the source range to highlight
+/// if there is an error.
+bool
+Sema::CheckDerivedToBaseConversion(QualType Derived, QualType Base,
+                                   AccessDiagnosticsKind ADK,
+                                   unsigned AmbigiousBaseConvID,
+                                   SourceLocation Loc, SourceRange Range,
+                                   DeclarationName Name) {
+  // First, determine whether the path from Derived to Base is
+  // ambiguous. This is slightly more expensive than checking whether
+  // the Derived to Base conversion exists, because here we need to
+  // explore multiple paths to determine if there is an ambiguity.
+  CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
+                     /*DetectVirtual=*/false);
+  bool DerivationOkay = IsDerivedFrom(Derived, Base, Paths);
+  assert(DerivationOkay &&
+         "Can only be used with a derived-to-base conversion");
+  (void)DerivationOkay;
+  
+  if (!Paths.isAmbiguous(Context.getCanonicalType(Base).getUnqualifiedType())) {
+    if (ADK == ADK_quiet)
+      return false;
+
+    // Check that the base class can be accessed.
+    switch (CheckBaseClassAccess(Loc, /*IsBaseToDerived*/ false,
+                                 Base, Derived, Paths.front(),
+                                 /*force*/ false,
+                                 /*unprivileged*/ false,
+                                 ADK)) {
+    case AR_accessible: return false;
+    case AR_inaccessible: return true;
+    case AR_dependent: return false;
+    case AR_delayed: return false;
+    }
+  }
+  
+  // We know that the derived-to-base conversion is ambiguous, and
+  // we're going to produce a diagnostic. Perform the derived-to-base
+  // search just one more time to compute all of the possible paths so
+  // that we can print them out. This is more expensive than any of
+  // the previous derived-to-base checks we've done, but at this point
+  // performance isn't as much of an issue.
+  Paths.clear();
+  Paths.setRecordingPaths(true);
+  bool StillOkay = IsDerivedFrom(Derived, Base, Paths);
+  assert(StillOkay && "Can only be used with a derived-to-base conversion");
+  (void)StillOkay;
+  
+  // Build up a textual representation of the ambiguous paths, e.g.,
+  // D -> B -> A, that will be used to illustrate the ambiguous
+  // conversions in the diagnostic. We only print one of the paths
+  // to each base class subobject.
+  std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths);
+  
+  Diag(Loc, AmbigiousBaseConvID)
+  << Derived << Base << PathDisplayStr << Range << Name;
+  return true;
+}
+
+bool
+Sema::CheckDerivedToBaseConversion(QualType Derived, QualType Base,
+                                   SourceLocation Loc, SourceRange Range,
+                                   bool IgnoreAccess) {
+  return CheckDerivedToBaseConversion(Derived, Base,
+                                      IgnoreAccess ? ADK_quiet : ADK_normal,
+                                      diag::err_ambiguous_derived_to_base_conv,
+                                      Loc, Range, DeclarationName());
+}
+
+
+/// @brief Builds a string representing ambiguous paths from a
+/// specific derived class to different subobjects of the same base
+/// class.
+///
+/// This function builds a string that can be used in error messages
+/// to show the different paths that one can take through the
+/// inheritance hierarchy to go from the derived class to different
+/// subobjects of a base class. The result looks something like this:
+/// @code
+/// struct D -> struct B -> struct A
+/// struct D -> struct C -> struct A
+/// @endcode
+std::string Sema::getAmbiguousPathsDisplayString(CXXBasePaths &Paths) {
+  std::string PathDisplayStr;
+  std::set<unsigned> DisplayedPaths;
+  for (CXXBasePaths::paths_iterator Path = Paths.begin();
+       Path != Paths.end(); ++Path) {
+    if (DisplayedPaths.insert(Path->back().SubobjectNumber).second) {
+      // We haven't displayed a path to this particular base
+      // class subobject yet.
+      PathDisplayStr += "\n    ";
+      PathDisplayStr += Context.getTypeDeclType(Paths.getOrigin()).getAsString();
+      for (CXXBasePath::const_iterator Element = Path->begin();
+           Element != Path->end(); ++Element)
+        PathDisplayStr += " -> " + Element->Base->getType().getAsString();
+    }
+  }
+  
+  return PathDisplayStr;
+}
+
+//===----------------------------------------------------------------------===//
+// C++ class member Handling
+//===----------------------------------------------------------------------===//
+
+/// ActOnCXXMemberDeclarator - This is invoked when a C++ class member
+/// declarator is parsed. 'AS' is the access specifier, 'BW' specifies the
+/// bitfield width if there is one and 'InitExpr' specifies the initializer if
+/// any.
+Sema::DeclPtrTy
+Sema::ActOnCXXMemberDeclarator(Scope *S, AccessSpecifier AS, Declarator &D,
+                               MultiTemplateParamsArg TemplateParameterLists,
+                               ExprTy *BW, ExprTy *InitExpr, bool IsDefinition,
+                               bool Deleted) {
+  const DeclSpec &DS = D.getDeclSpec();
+  DeclarationName Name = GetNameForDeclarator(D);
+  Expr *BitWidth = static_cast<Expr*>(BW);
+  Expr *Init = static_cast<Expr*>(InitExpr);
+  SourceLocation Loc = D.getIdentifierLoc();
+
+  bool isFunc = D.isFunctionDeclarator();
+
+  assert(!DS.isFriendSpecified());
+
+  // C++ 9.2p6: A member shall not be declared to have automatic storage
+  // duration (auto, register) or with the extern storage-class-specifier.
+  // C++ 7.1.1p8: The mutable specifier can be applied only to names of class
+  // data members and cannot be applied to names declared const or static,
+  // and cannot be applied to reference members.
+  switch (DS.getStorageClassSpec()) {
+    case DeclSpec::SCS_unspecified:
+    case DeclSpec::SCS_typedef:
+    case DeclSpec::SCS_static:
+      // FALL THROUGH.
+      break;
+    case DeclSpec::SCS_mutable:
+      if (isFunc) {
+        if (DS.getStorageClassSpecLoc().isValid())
+          Diag(DS.getStorageClassSpecLoc(), diag::err_mutable_function);
+        else
+          Diag(DS.getThreadSpecLoc(), diag::err_mutable_function);
+
+        // FIXME: It would be nicer if the keyword was ignored only for this
+        // declarator. Otherwise we could get follow-up errors.
+        D.getMutableDeclSpec().ClearStorageClassSpecs();
+      } else {
+        QualType T = GetTypeForDeclarator(D, S);
+        diag::kind err = static_cast<diag::kind>(0);
+        if (T->isReferenceType())
+          err = diag::err_mutable_reference;
+        else if (T.isConstQualified())
+          err = diag::err_mutable_const;
+        if (err != 0) {
+          if (DS.getStorageClassSpecLoc().isValid())
+            Diag(DS.getStorageClassSpecLoc(), err);
+          else
+            Diag(DS.getThreadSpecLoc(), err);
+          // FIXME: It would be nicer if the keyword was ignored only for this
+          // declarator. Otherwise we could get follow-up errors.
+          D.getMutableDeclSpec().ClearStorageClassSpecs();
+        }
+      }
+      break;
+    default:
+      if (DS.getStorageClassSpecLoc().isValid())
+        Diag(DS.getStorageClassSpecLoc(),
+             diag::err_storageclass_invalid_for_member);
+      else
+        Diag(DS.getThreadSpecLoc(), diag::err_storageclass_invalid_for_member);
+      D.getMutableDeclSpec().ClearStorageClassSpecs();
+  }
+
+  if (!isFunc &&
+      D.getDeclSpec().getTypeSpecType() == DeclSpec::TST_typename &&
+      D.getNumTypeObjects() == 0) {
+    // Check also for this case:
+    //
+    // typedef int f();
+    // f a;
+    //
+    QualType TDType = GetTypeFromParser(DS.getTypeRep());
+    isFunc = TDType->isFunctionType();
+  }
+
+  bool isInstField = ((DS.getStorageClassSpec() == DeclSpec::SCS_unspecified ||
+                       DS.getStorageClassSpec() == DeclSpec::SCS_mutable) &&
+                      !isFunc);
+
+  Decl *Member;
+  if (isInstField) {
+    // FIXME: Check for template parameters!
+    Member = HandleField(S, cast<CXXRecordDecl>(CurContext), Loc, D, BitWidth,
+                         AS);
+    assert(Member && "HandleField never returns null");
+  } else {
+    Member = HandleDeclarator(S, D, move(TemplateParameterLists), IsDefinition)
+               .getAs<Decl>();
+    if (!Member) {
+      if (BitWidth) DeleteExpr(BitWidth);
+      return DeclPtrTy();
+    }
+
+    // Non-instance-fields can't have a bitfield.
+    if (BitWidth) {
+      if (Member->isInvalidDecl()) {
+        // don't emit another diagnostic.
+      } else if (isa<VarDecl>(Member)) {
+        // C++ 9.6p3: A bit-field shall not be a static member.
+        // "static member 'A' cannot be a bit-field"
+        Diag(Loc, diag::err_static_not_bitfield)
+          << Name << BitWidth->getSourceRange();
+      } else if (isa<TypedefDecl>(Member)) {
+        // "typedef member 'x' cannot be a bit-field"
+        Diag(Loc, diag::err_typedef_not_bitfield)
+          << Name << BitWidth->getSourceRange();
+      } else {
+        // A function typedef ("typedef int f(); f a;").
+        // C++ 9.6p3: A bit-field shall have integral or enumeration type.
+        Diag(Loc, diag::err_not_integral_type_bitfield)
+          << Name << cast<ValueDecl>(Member)->getType()
+          << BitWidth->getSourceRange();
+      }
+
+      DeleteExpr(BitWidth);
+      BitWidth = 0;
+      Member->setInvalidDecl();
+    }
+
+    Member->setAccess(AS);
+
+    // If we have declared a member function template, set the access of the
+    // templated declaration as well.
+    if (FunctionTemplateDecl *FunTmpl = dyn_cast<FunctionTemplateDecl>(Member))
+      FunTmpl->getTemplatedDecl()->setAccess(AS);
+  }
+
+  assert((Name || isInstField) && "No identifier for non-field ?");
+
+  if (Init)
+    AddInitializerToDecl(DeclPtrTy::make(Member), ExprArg(*this, Init), false);
+  if (Deleted) // FIXME: Source location is not very good.
+    SetDeclDeleted(DeclPtrTy::make(Member), D.getSourceRange().getBegin());
+
+  if (isInstField) {
+    FieldCollector->Add(cast<FieldDecl>(Member));
+    return DeclPtrTy();
+  }
+  return DeclPtrTy::make(Member);
+}
+
+/// \brief Find the direct and/or virtual base specifiers that
+/// correspond to the given base type, for use in base initialization
+/// within a constructor.
+static bool FindBaseInitializer(Sema &SemaRef, 
+                                CXXRecordDecl *ClassDecl,
+                                QualType BaseType,
+                                const CXXBaseSpecifier *&DirectBaseSpec,
+                                const CXXBaseSpecifier *&VirtualBaseSpec) {
+  // First, check for a direct base class.
+  DirectBaseSpec = 0;
+  for (CXXRecordDecl::base_class_const_iterator Base
+         = ClassDecl->bases_begin(); 
+       Base != ClassDecl->bases_end(); ++Base) {
+    if (SemaRef.Context.hasSameUnqualifiedType(BaseType, Base->getType())) {
+      // We found a direct base of this type. That's what we're
+      // initializing.
+      DirectBaseSpec = &*Base;
+      break;
+    }
+  }
+
+  // Check for a virtual base class.
+  // FIXME: We might be able to short-circuit this if we know in advance that
+  // there are no virtual bases.
+  VirtualBaseSpec = 0;
+  if (!DirectBaseSpec || !DirectBaseSpec->isVirtual()) {
+    // We haven't found a base yet; search the class hierarchy for a
+    // virtual base class.
+    CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
+                       /*DetectVirtual=*/false);
+    if (SemaRef.IsDerivedFrom(SemaRef.Context.getTypeDeclType(ClassDecl), 
+                              BaseType, Paths)) {
+      for (CXXBasePaths::paths_iterator Path = Paths.begin();
+           Path != Paths.end(); ++Path) {
+        if (Path->back().Base->isVirtual()) {
+          VirtualBaseSpec = Path->back().Base;
+          break;
+        }
+      }
+    }
+  }
+
+  return DirectBaseSpec || VirtualBaseSpec;
+}
+
+/// ActOnMemInitializer - Handle a C++ member initializer.
+Sema::MemInitResult
+Sema::ActOnMemInitializer(DeclPtrTy ConstructorD,
+                          Scope *S,
+                          const CXXScopeSpec &SS,
+                          IdentifierInfo *MemberOrBase,
+                          TypeTy *TemplateTypeTy,
+                          SourceLocation IdLoc,
+                          SourceLocation LParenLoc,
+                          ExprTy **Args, unsigned NumArgs,
+                          SourceLocation *CommaLocs,
+                          SourceLocation RParenLoc) {
+  if (!ConstructorD)
+    return true;
+
+  AdjustDeclIfTemplate(ConstructorD);
+
+  CXXConstructorDecl *Constructor
+    = dyn_cast<CXXConstructorDecl>(ConstructorD.getAs<Decl>());
+  if (!Constructor) {
+    // The user wrote a constructor initializer on a function that is
+    // not a C++ constructor. Ignore the error for now, because we may
+    // have more member initializers coming; we'll diagnose it just
+    // once in ActOnMemInitializers.
+    return true;
+  }
+
+  CXXRecordDecl *ClassDecl = Constructor->getParent();
+
+  // C++ [class.base.init]p2:
+  //   Names in a mem-initializer-id are looked up in the scope of the
+  //   constructor’s class and, if not found in that scope, are looked
+  //   up in the scope containing the constructor’s
+  //   definition. [Note: if the constructor’s class contains a member
+  //   with the same name as a direct or virtual base class of the
+  //   class, a mem-initializer-id naming the member or base class and
+  //   composed of a single identifier refers to the class member. A
+  //   mem-initializer-id for the hidden base class may be specified
+  //   using a qualified name. ]
+  if (!SS.getScopeRep() && !TemplateTypeTy) {
+    // Look for a member, first.
+    FieldDecl *Member = 0;
+    DeclContext::lookup_result Result
+      = ClassDecl->lookup(MemberOrBase);
+    if (Result.first != Result.second)
+      Member = dyn_cast<FieldDecl>(*Result.first);
+
+    // FIXME: Handle members of an anonymous union.
+
+    if (Member)
+      return BuildMemberInitializer(Member, (Expr**)Args, NumArgs, IdLoc,
+                                    LParenLoc, RParenLoc);
+  }
+  // It didn't name a member, so see if it names a class.
+  QualType BaseType;
+  TypeSourceInfo *TInfo = 0;
+
+  if (TemplateTypeTy) {
+    BaseType = GetTypeFromParser(TemplateTypeTy, &TInfo);
+  } else {
+    LookupResult R(*this, MemberOrBase, IdLoc, LookupOrdinaryName);
+    LookupParsedName(R, S, &SS);
+
+    TypeDecl *TyD = R.getAsSingle<TypeDecl>();
+    if (!TyD) {
+      if (R.isAmbiguous()) return true;
+
+      if (SS.isSet() && isDependentScopeSpecifier(SS)) {
+        bool NotUnknownSpecialization = false;
+        DeclContext *DC = computeDeclContext(SS, false);
+        if (CXXRecordDecl *Record = dyn_cast_or_null<CXXRecordDecl>(DC)) 
+          NotUnknownSpecialization = !Record->hasAnyDependentBases();
+
+        if (!NotUnknownSpecialization) {
+          // When the scope specifier can refer to a member of an unknown
+          // specialization, we take it as a type name.
+          BaseType = CheckTypenameType((NestedNameSpecifier *)SS.getScopeRep(),
+                                       *MemberOrBase, SS.getRange());
+          R.clear();
+        }
+      }
+
+      // If no results were found, try to correct typos.
+      if (R.empty() && BaseType.isNull() &&
+          CorrectTypo(R, S, &SS, ClassDecl) && R.isSingleResult()) {
+        if (FieldDecl *Member = R.getAsSingle<FieldDecl>()) {
+          if (Member->getDeclContext()->getLookupContext()->Equals(ClassDecl)) {
+            // We have found a non-static data member with a similar
+            // name to what was typed; complain and initialize that
+            // member.
+            Diag(R.getNameLoc(), diag::err_mem_init_not_member_or_class_suggest)
+              << MemberOrBase << true << R.getLookupName()
+              << CodeModificationHint::CreateReplacement(R.getNameLoc(),
+                                               R.getLookupName().getAsString());
+            Diag(Member->getLocation(), diag::note_previous_decl)
+              << Member->getDeclName();
+
+            return BuildMemberInitializer(Member, (Expr**)Args, NumArgs, IdLoc,
+                                          LParenLoc, RParenLoc);
+          }
+        } else if (TypeDecl *Type = R.getAsSingle<TypeDecl>()) {
+          const CXXBaseSpecifier *DirectBaseSpec;
+          const CXXBaseSpecifier *VirtualBaseSpec;
+          if (FindBaseInitializer(*this, ClassDecl, 
+                                  Context.getTypeDeclType(Type),
+                                  DirectBaseSpec, VirtualBaseSpec)) {
+            // We have found a direct or virtual base class with a
+            // similar name to what was typed; complain and initialize
+            // that base class.
+            Diag(R.getNameLoc(), diag::err_mem_init_not_member_or_class_suggest)
+              << MemberOrBase << false << R.getLookupName()
+              << CodeModificationHint::CreateReplacement(R.getNameLoc(),
+                                               R.getLookupName().getAsString());
+
+            const CXXBaseSpecifier *BaseSpec = DirectBaseSpec? DirectBaseSpec 
+                                                             : VirtualBaseSpec;
+            Diag(BaseSpec->getSourceRange().getBegin(),
+                 diag::note_base_class_specified_here)
+              << BaseSpec->getType()
+              << BaseSpec->getSourceRange();
+
+            TyD = Type;
+          }
+        }
+      }
+
+      if (!TyD && BaseType.isNull()) {
+        Diag(IdLoc, diag::err_mem_init_not_member_or_class)
+          << MemberOrBase << SourceRange(IdLoc, RParenLoc);
+        return true;
+      }
+    }
+
+    if (BaseType.isNull()) {
+      BaseType = Context.getTypeDeclType(TyD);
+      if (SS.isSet()) {
+        NestedNameSpecifier *Qualifier =
+          static_cast<NestedNameSpecifier*>(SS.getScopeRep());
+
+        // FIXME: preserve source range information
+        BaseType = Context.getQualifiedNameType(Qualifier, BaseType);
+      }
+    }
+  }
+
+  if (!TInfo)
+    TInfo = Context.getTrivialTypeSourceInfo(BaseType, IdLoc);
+
+  return BuildBaseInitializer(BaseType, TInfo, (Expr **)Args, NumArgs, 
+                              LParenLoc, RParenLoc, ClassDecl);
+}
+
+/// Checks an initializer expression for use of uninitialized fields, such as
+/// containing the field that is being initialized. Returns true if there is an
+/// uninitialized field was used an updates the SourceLocation parameter; false
+/// otherwise.
+static bool InitExprContainsUninitializedFields(const Stmt* S,
+                                                const FieldDecl* LhsField,
+                                                SourceLocation* L) {
+  const MemberExpr* ME = dyn_cast<MemberExpr>(S);
+  if (ME) {
+    const NamedDecl* RhsField = ME->getMemberDecl();
+    if (RhsField == LhsField) {
+      // Initializing a field with itself. Throw a warning.
+      // But wait; there are exceptions!
+      // Exception #1:  The field may not belong to this record.
+      // e.g. Foo(const Foo& rhs) : A(rhs.A) {}
+      const Expr* base = ME->getBase();
+      if (base != NULL && !isa<CXXThisExpr>(base->IgnoreParenCasts())) {
+        // Even though the field matches, it does not belong to this record.
+        return false;
+      }
+      // None of the exceptions triggered; return true to indicate an
+      // uninitialized field was used.
+      *L = ME->getMemberLoc();
+      return true;
+    }
+  }
+  bool found = false;
+  for (Stmt::const_child_iterator it = S->child_begin();
+       it != S->child_end() && found == false;
+       ++it) {
+    if (isa<CallExpr>(S)) {
+      // Do not descend into function calls or constructors, as the use
+      // of an uninitialized field may be valid. One would have to inspect
+      // the contents of the function/ctor to determine if it is safe or not.
+      // i.e. Pass-by-value is never safe, but pass-by-reference and pointers
+      // may be safe, depending on what the function/ctor does.
+      continue;
+    }
+    found = InitExprContainsUninitializedFields(*it, LhsField, L);
+  }
+  return found;
+}
+
+Sema::MemInitResult
+Sema::BuildMemberInitializer(FieldDecl *Member, Expr **Args,
+                             unsigned NumArgs, SourceLocation IdLoc,
+                             SourceLocation LParenLoc,
+                             SourceLocation RParenLoc) {
+  // Diagnose value-uses of fields to initialize themselves, e.g.
+  //   foo(foo)
+  // where foo is not also a parameter to the constructor.
+  // TODO: implement -Wuninitialized and fold this into that framework.
+  for (unsigned i = 0; i < NumArgs; ++i) {
+    SourceLocation L;
+    if (InitExprContainsUninitializedFields(Args[i], Member, &L)) {
+      // FIXME: Return true in the case when other fields are used before being
+      // uninitialized. For example, let this field be the i'th field. When
+      // initializing the i'th field, throw a warning if any of the >= i'th
+      // fields are used, as they are not yet initialized.
+      // Right now we are only handling the case where the i'th field uses
+      // itself in its initializer.
+      Diag(L, diag::warn_field_is_uninit);
+    }
+  }
+
+  bool HasDependentArg = false;
+  for (unsigned i = 0; i < NumArgs; i++)
+    HasDependentArg |= Args[i]->isTypeDependent();
+
+  QualType FieldType = Member->getType();
+  if (const ArrayType *Array = Context.getAsArrayType(FieldType))
+    FieldType = Array->getElementType();
+  ASTOwningVector<&ActionBase::DeleteExpr> ConstructorArgs(*this);
+  if (FieldType->isDependentType() || HasDependentArg) {
+    // Can't check initialization for a member of dependent type or when
+    // any of the arguments are type-dependent expressions.
+    OwningExprResult Init
+      = Owned(new (Context) ParenListExpr(Context, LParenLoc, Args, NumArgs,
+                                          RParenLoc));
+
+    // Erase any temporaries within this evaluation context; we're not
+    // going to track them in the AST, since we'll be rebuilding the
+    // ASTs during template instantiation.
+    ExprTemporaries.erase(
+              ExprTemporaries.begin() + ExprEvalContexts.back().NumTemporaries,
+                          ExprTemporaries.end());
+    
+    return new (Context) CXXBaseOrMemberInitializer(Context, Member, IdLoc,
+                                                    LParenLoc, 
+                                                    Init.takeAs<Expr>(),
+                                                    RParenLoc);
+    
+  }
+  
+  if (Member->isInvalidDecl())
+    return true;
+  
+  // Initialize the member.
+  InitializedEntity MemberEntity =
+    InitializedEntity::InitializeMember(Member, 0);
+  InitializationKind Kind = 
+    InitializationKind::CreateDirect(IdLoc, LParenLoc, RParenLoc);
+  
+  InitializationSequence InitSeq(*this, MemberEntity, Kind, Args, NumArgs);
+  
+  OwningExprResult MemberInit =
+    InitSeq.Perform(*this, MemberEntity, Kind, 
+                    MultiExprArg(*this, (void**)Args, NumArgs), 0);
+  if (MemberInit.isInvalid())
+    return true;
+  
+  // C++0x [class.base.init]p7:
+  //   The initialization of each base and member constitutes a 
+  //   full-expression.
+  MemberInit = MaybeCreateCXXExprWithTemporaries(move(MemberInit));
+  if (MemberInit.isInvalid())
+    return true;
+  
+  // If we are in a dependent context, template instantiation will
+  // perform this type-checking again. Just save the arguments that we
+  // received in a ParenListExpr.
+  // FIXME: This isn't quite ideal, since our ASTs don't capture all
+  // of the information that we have about the member
+  // initializer. However, deconstructing the ASTs is a dicey process,
+  // and this approach is far more likely to get the corner cases right.
+  if (CurContext->isDependentContext()) {
+    // Bump the reference count of all of the arguments.
+    for (unsigned I = 0; I != NumArgs; ++I)
+      Args[I]->Retain();
+
+    OwningExprResult Init
+      = Owned(new (Context) ParenListExpr(Context, LParenLoc, Args, NumArgs,
+                                          RParenLoc));
+    return new (Context) CXXBaseOrMemberInitializer(Context, Member, IdLoc,
+                                                    LParenLoc, 
+                                                    Init.takeAs<Expr>(),
+                                                    RParenLoc);
+  }
+
+  return new (Context) CXXBaseOrMemberInitializer(Context, Member, IdLoc,
+                                                  LParenLoc, 
+                                                  MemberInit.takeAs<Expr>(),
+                                                  RParenLoc);
+}
+
+Sema::MemInitResult
+Sema::BuildBaseInitializer(QualType BaseType, TypeSourceInfo *BaseTInfo,
+                           Expr **Args, unsigned NumArgs, 
+                           SourceLocation LParenLoc, SourceLocation RParenLoc, 
+                           CXXRecordDecl *ClassDecl) {
+  bool HasDependentArg = false;
+  for (unsigned i = 0; i < NumArgs; i++)
+    HasDependentArg |= Args[i]->isTypeDependent();
+
+  SourceLocation BaseLoc = BaseTInfo->getTypeLoc().getSourceRange().getBegin();
+  if (BaseType->isDependentType() || HasDependentArg) {
+    // Can't check initialization for a base of dependent type or when
+    // any of the arguments are type-dependent expressions.
+    OwningExprResult BaseInit
+      = Owned(new (Context) ParenListExpr(Context, LParenLoc, Args, NumArgs,
+                                          RParenLoc));
+
+    // Erase any temporaries within this evaluation context; we're not
+    // going to track them in the AST, since we'll be rebuilding the
+    // ASTs during template instantiation.
+    ExprTemporaries.erase(
+              ExprTemporaries.begin() + ExprEvalContexts.back().NumTemporaries,
+                          ExprTemporaries.end());
+
+    return new (Context) CXXBaseOrMemberInitializer(Context, BaseTInfo, 
+                                                    LParenLoc, 
+                                                    BaseInit.takeAs<Expr>(),
+                                                    RParenLoc);
+  }
+  
+  if (!BaseType->isRecordType())
+    return Diag(BaseLoc, diag::err_base_init_does_not_name_class)
+             << BaseType << BaseTInfo->getTypeLoc().getSourceRange();
+
+  // C++ [class.base.init]p2:
+  //   [...] Unless the mem-initializer-id names a nonstatic data
+  //   member of the constructor’s class or a direct or virtual base
+  //   of that class, the mem-initializer is ill-formed. A
+  //   mem-initializer-list can initialize a base class using any
+  //   name that denotes that base class type.
+
+  // Check for direct and virtual base classes.
+  const CXXBaseSpecifier *DirectBaseSpec = 0;
+  const CXXBaseSpecifier *VirtualBaseSpec = 0;
+  FindBaseInitializer(*this, ClassDecl, BaseType, DirectBaseSpec, 
+                      VirtualBaseSpec);
+
+  // C++ [base.class.init]p2:
+  //   If a mem-initializer-id is ambiguous because it designates both
+  //   a direct non-virtual base class and an inherited virtual base
+  //   class, the mem-initializer is ill-formed.
+  if (DirectBaseSpec && VirtualBaseSpec)
+    return Diag(BaseLoc, diag::err_base_init_direct_and_virtual)
+      << BaseType << BaseTInfo->getTypeLoc().getSourceRange();
+  // C++ [base.class.init]p2:
+  // Unless the mem-initializer-id names a nonstatic data membeer of the
+  // constructor's class ot a direst or virtual base of that class, the
+  // mem-initializer is ill-formed.
+  if (!DirectBaseSpec && !VirtualBaseSpec)
+    return Diag(BaseLoc, diag::err_not_direct_base_or_virtual)
+      << BaseType << ClassDecl->getNameAsCString()
+      << BaseTInfo->getTypeLoc().getSourceRange();
+
+  CXXBaseSpecifier *BaseSpec
+    = const_cast<CXXBaseSpecifier *>(DirectBaseSpec);
+  if (!BaseSpec)
+    BaseSpec = const_cast<CXXBaseSpecifier *>(VirtualBaseSpec);
+
+  // Initialize the base.
+  InitializedEntity BaseEntity =
+    InitializedEntity::InitializeBase(Context, BaseSpec);
+  InitializationKind Kind = 
+    InitializationKind::CreateDirect(BaseLoc, LParenLoc, RParenLoc);
+  
+  InitializationSequence InitSeq(*this, BaseEntity, Kind, Args, NumArgs);
+  
+  OwningExprResult BaseInit =
+    InitSeq.Perform(*this, BaseEntity, Kind, 
+                    MultiExprArg(*this, (void**)Args, NumArgs), 0);
+  if (BaseInit.isInvalid())
+    return true;
+  
+  // C++0x [class.base.init]p7:
+  //   The initialization of each base and member constitutes a 
+  //   full-expression.
+  BaseInit = MaybeCreateCXXExprWithTemporaries(move(BaseInit));
+  if (BaseInit.isInvalid())
+    return true;
+
+  // If we are in a dependent context, template instantiation will
+  // perform this type-checking again. Just save the arguments that we
+  // received in a ParenListExpr.
+  // FIXME: This isn't quite ideal, since our ASTs don't capture all
+  // of the information that we have about the base
+  // initializer. However, deconstructing the ASTs is a dicey process,
+  // and this approach is far more likely to get the corner cases right.
+  if (CurContext->isDependentContext()) {
+    // Bump the reference count of all of the arguments.
+    for (unsigned I = 0; I != NumArgs; ++I)
+      Args[I]->Retain();
+
+    OwningExprResult Init
+      = Owned(new (Context) ParenListExpr(Context, LParenLoc, Args, NumArgs,
+                                          RParenLoc));
+    return new (Context) CXXBaseOrMemberInitializer(Context, BaseTInfo,
+                                                    LParenLoc, 
+                                                    Init.takeAs<Expr>(),
+                                                    RParenLoc);
+  }
+
+  return new (Context) CXXBaseOrMemberInitializer(Context, BaseTInfo,
+                                                  LParenLoc, 
+                                                  BaseInit.takeAs<Expr>(),
+                                                  RParenLoc);
+}
+
+bool
+Sema::SetBaseOrMemberInitializers(CXXConstructorDecl *Constructor,
+                                  CXXBaseOrMemberInitializer **Initializers,
+                                  unsigned NumInitializers,
+                                  bool IsImplicitConstructor,
+                                  bool AnyErrors) {
+  // We need to build the initializer AST according to order of construction
+  // and not what user specified in the Initializers list.
+  CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(Constructor->getDeclContext());
+  llvm::SmallVector<CXXBaseOrMemberInitializer*, 32> AllToInit;
+  llvm::DenseMap<const void *, CXXBaseOrMemberInitializer*> AllBaseFields;
+  bool HasDependentBaseInit = false;
+  bool HadError = false;
+
+  for (unsigned i = 0; i < NumInitializers; i++) {
+    CXXBaseOrMemberInitializer *Member = Initializers[i];
+    if (Member->isBaseInitializer()) {
+      if (Member->getBaseClass()->isDependentType())
+        HasDependentBaseInit = true;
+      AllBaseFields[Member->getBaseClass()->getAs<RecordType>()] = Member;
+    } else {
+      AllBaseFields[Member->getMember()] = Member;
+    }
+  }
+
+  if (HasDependentBaseInit) {
+    // FIXME. This does not preserve the ordering of the initializers.
+    // Try (with -Wreorder)
+    // template<class X> struct A {};
+    // template<class X> struct B : A<X> {
+    //   B() : x1(10), A<X>() {}
+    //   int x1;
+    // };
+    // B<int> x;
+    // On seeing one dependent type, we should essentially exit this routine
+    // while preserving user-declared initializer list. When this routine is
+    // called during instantiatiation process, this routine will rebuild the
+    // ordered initializer list correctly.
+
+    // If we have a dependent base initialization, we can't determine the
+    // association between initializers and bases; just dump the known
+    // initializers into the list, and don't try to deal with other bases.
+    for (unsigned i = 0; i < NumInitializers; i++) {
+      CXXBaseOrMemberInitializer *Member = Initializers[i];
+      if (Member->isBaseInitializer())
+        AllToInit.push_back(Member);
+    }
+  } else {
+    llvm::SmallVector<CXXBaseSpecifier *, 4> BasesToDefaultInit;
+    
+    // Push virtual bases before others.
+    for (CXXRecordDecl::base_class_iterator VBase =
+         ClassDecl->vbases_begin(),
+         E = ClassDecl->vbases_end(); VBase != E; ++VBase) {
+      if (VBase->getType()->isDependentType())
+        continue;
+      if (CXXBaseOrMemberInitializer *Value
+            = AllBaseFields.lookup(VBase->getType()->getAs<RecordType>())) {
+        AllToInit.push_back(Value);
+      } else if (!AnyErrors) {
+        InitializedEntity InitEntity
+          = InitializedEntity::InitializeBase(Context, VBase);
+        InitializationKind InitKind
+          = InitializationKind::CreateDefault(Constructor->getLocation());
+        InitializationSequence InitSeq(*this, InitEntity, InitKind, 0, 0);        
+        OwningExprResult BaseInit = InitSeq.Perform(*this, InitEntity, InitKind,
+                                                    MultiExprArg(*this, 0, 0));
+        BaseInit = MaybeCreateCXXExprWithTemporaries(move(BaseInit));
+        if (BaseInit.isInvalid()) {
+          HadError = true;
+          continue;
+        }
+
+        // Don't attach synthesized base initializers in a dependent
+        // context; they'll be checked again at template instantiation
+        // time.
+        if (CurContext->isDependentContext())
+          continue;
+        
+        CXXBaseOrMemberInitializer *CXXBaseInit =
+          new (Context) CXXBaseOrMemberInitializer(Context,
+                             Context.getTrivialTypeSourceInfo(VBase->getType(), 
+                                                              SourceLocation()),
+                                                   SourceLocation(),
+                                                   BaseInit.takeAs<Expr>(),
+                                                   SourceLocation());
+        AllToInit.push_back(CXXBaseInit);
+      }
+    }
+
+    for (CXXRecordDecl::base_class_iterator Base =
+         ClassDecl->bases_begin(),
+         E = ClassDecl->bases_end(); Base != E; ++Base) {
+      // Virtuals are in the virtual base list and already constructed.
+      if (Base->isVirtual())
+        continue;
+      // Skip dependent types.
+      if (Base->getType()->isDependentType())
+        continue;
+      if (CXXBaseOrMemberInitializer *Value
+            = AllBaseFields.lookup(Base->getType()->getAs<RecordType>())) {
+        AllToInit.push_back(Value);
+      }
+      else if (!AnyErrors) {
+        InitializedEntity InitEntity
+          = InitializedEntity::InitializeBase(Context, Base);
+        InitializationKind InitKind
+          = InitializationKind::CreateDefault(Constructor->getLocation());
+        InitializationSequence InitSeq(*this, InitEntity, InitKind, 0, 0);        
+        OwningExprResult BaseInit = InitSeq.Perform(*this, InitEntity, InitKind,
+                                                    MultiExprArg(*this, 0, 0));
+        BaseInit = MaybeCreateCXXExprWithTemporaries(move(BaseInit));
+        if (BaseInit.isInvalid()) {
+          HadError = true;
+          continue;
+        }
+        
+        // Don't attach synthesized base initializers in a dependent
+        // context; they'll be regenerated at template instantiation
+        // time.
+        if (CurContext->isDependentContext())
+          continue;
+        
+        CXXBaseOrMemberInitializer *CXXBaseInit =
+          new (Context) CXXBaseOrMemberInitializer(Context,
+                             Context.getTrivialTypeSourceInfo(Base->getType(), 
+                                                              SourceLocation()),
+                                                   SourceLocation(),
+                                                   BaseInit.takeAs<Expr>(),
+                                                   SourceLocation());
+        AllToInit.push_back(CXXBaseInit);
+      }
+    }
+  }
+
+  // non-static data members.
+  for (CXXRecordDecl::field_iterator Field = ClassDecl->field_begin(),
+       E = ClassDecl->field_end(); Field != E; ++Field) {
+    if ((*Field)->isAnonymousStructOrUnion()) {
+      if (const RecordType *FieldClassType =
+          Field->getType()->getAs<RecordType>()) {
+        CXXRecordDecl *FieldClassDecl
+          = cast<CXXRecordDecl>(FieldClassType->getDecl());
+        for (RecordDecl::field_iterator FA = FieldClassDecl->field_begin(),
+            EA = FieldClassDecl->field_end(); FA != EA; FA++) {
+          if (CXXBaseOrMemberInitializer *Value = AllBaseFields.lookup(*FA)) {
+            // 'Member' is the anonymous union field and 'AnonUnionMember' is
+            // set to the anonymous union data member used in the initializer
+            // list.
+            Value->setMember(*Field);
+            Value->setAnonUnionMember(*FA);
+            AllToInit.push_back(Value);
+            break;
+          }
+        }
+      }
+      continue;
+    }
+    if (CXXBaseOrMemberInitializer *Value = AllBaseFields.lookup(*Field)) {
+      AllToInit.push_back(Value);
+      continue;
+    }
+
+    if ((*Field)->getType()->isDependentType() || AnyErrors)
+      continue;
+    
+    QualType FT = Context.getBaseElementType((*Field)->getType());
+    if (FT->getAs<RecordType>()) {
+      InitializedEntity InitEntity
+        = InitializedEntity::InitializeMember(*Field);
+      InitializationKind InitKind
+        = InitializationKind::CreateDefault(Constructor->getLocation());
+
+      InitializationSequence InitSeq(*this, InitEntity, InitKind, 0, 0);
+      OwningExprResult MemberInit = InitSeq.Perform(*this, InitEntity, InitKind,
+                                                    MultiExprArg(*this, 0, 0));
+      MemberInit = MaybeCreateCXXExprWithTemporaries(move(MemberInit));
+      if (MemberInit.isInvalid()) {
+        HadError = true;
+        continue;
+      }
+      
+      // Don't attach synthesized member initializers in a dependent
+      // context; they'll be regenerated a template instantiation
+      // time.
+      if (CurContext->isDependentContext())
+        continue;
+      
+      CXXBaseOrMemberInitializer *Member =
+        new (Context) CXXBaseOrMemberInitializer(Context,
+                                                 *Field, SourceLocation(),
+                                                 SourceLocation(),
+                                                 MemberInit.takeAs<Expr>(),
+                                                 SourceLocation());
+
+      AllToInit.push_back(Member);
+    }
+    else if (FT->isReferenceType()) {
+      Diag(Constructor->getLocation(), diag::err_uninitialized_member_in_ctor)
+        << (int)IsImplicitConstructor << Context.getTagDeclType(ClassDecl)
+        << 0 << (*Field)->getDeclName();
+      Diag((*Field)->getLocation(), diag::note_declared_at);
+      HadError = true;
+    }
+    else if (FT.isConstQualified()) {
+      Diag(Constructor->getLocation(), diag::err_uninitialized_member_in_ctor)
+        << (int)IsImplicitConstructor << Context.getTagDeclType(ClassDecl)
+        << 1 << (*Field)->getDeclName();
+      Diag((*Field)->getLocation(), diag::note_declared_at);
+      HadError = true;
+    }
+  }
+
+  NumInitializers = AllToInit.size();
+  if (NumInitializers > 0) {
+    Constructor->setNumBaseOrMemberInitializers(NumInitializers);
+    CXXBaseOrMemberInitializer **baseOrMemberInitializers =
+      new (Context) CXXBaseOrMemberInitializer*[NumInitializers];
+
+    Constructor->setBaseOrMemberInitializers(baseOrMemberInitializers);
+    for (unsigned Idx = 0; Idx < NumInitializers; ++Idx)
+      baseOrMemberInitializers[Idx] = AllToInit[Idx];
+  }
+
+  return HadError;
+}
+
+static void *GetKeyForTopLevelField(FieldDecl *Field) {
+  // For anonymous unions, use the class declaration as the key.
+  if (const RecordType *RT = Field->getType()->getAs<RecordType>()) {
+    if (RT->getDecl()->isAnonymousStructOrUnion())
+      return static_cast<void *>(RT->getDecl());
+  }
+  return static_cast<void *>(Field);
+}
+
+static void *GetKeyForBase(QualType BaseType) {
+  if (const RecordType *RT = BaseType->getAs<RecordType>())
+    return (void *)RT;
+
+  assert(0 && "Unexpected base type!");
+  return 0;
+}
+
+static void *GetKeyForMember(CXXBaseOrMemberInitializer *Member,
+                             bool MemberMaybeAnon = false) {
+  // For fields injected into the class via declaration of an anonymous union,
+  // use its anonymous union class declaration as the unique key.
+  if (Member->isMemberInitializer()) {
+    FieldDecl *Field = Member->getMember();
+
+    // After SetBaseOrMemberInitializers call, Field is the anonymous union
+    // data member of the class. Data member used in the initializer list is
+    // in AnonUnionMember field.
+    if (MemberMaybeAnon && Field->isAnonymousStructOrUnion())
+      Field = Member->getAnonUnionMember();
+    if (Field->getDeclContext()->isRecord()) {
+      RecordDecl *RD = cast<RecordDecl>(Field->getDeclContext());
+      if (RD->isAnonymousStructOrUnion())
+        return static_cast<void *>(RD);
+    }
+    return static_cast<void *>(Field);
+  }
+
+  return GetKeyForBase(QualType(Member->getBaseClass(), 0));
+}
+
+/// ActOnMemInitializers - Handle the member initializers for a constructor.
+void Sema::ActOnMemInitializers(DeclPtrTy ConstructorDecl,
+                                SourceLocation ColonLoc,
+                                MemInitTy **MemInits, unsigned NumMemInits,
+                                bool AnyErrors) {
+  if (!ConstructorDecl)
+    return;
+
+  AdjustDeclIfTemplate(ConstructorDecl);
+
+  CXXConstructorDecl *Constructor
+    = dyn_cast<CXXConstructorDecl>(ConstructorDecl.getAs<Decl>());
+
+  if (!Constructor) {
+    Diag(ColonLoc, diag::err_only_constructors_take_base_inits);
+    return;
+  }
+
+  if (!Constructor->isDependentContext()) {
+    llvm::DenseMap<void*, CXXBaseOrMemberInitializer *>Members;
+    bool err = false;
+    for (unsigned i = 0; i < NumMemInits; i++) {
+      CXXBaseOrMemberInitializer *Member =
+        static_cast<CXXBaseOrMemberInitializer*>(MemInits[i]);
+      void *KeyToMember = GetKeyForMember(Member);
+      CXXBaseOrMemberInitializer *&PrevMember = Members[KeyToMember];
+      if (!PrevMember) {
+        PrevMember = Member;
+        continue;
+      }
+      if (FieldDecl *Field = Member->getMember())
+        Diag(Member->getSourceLocation(),
+             diag::error_multiple_mem_initialization)
+          << Field->getNameAsString()
+          << Member->getSourceRange();
+      else {
+        Type *BaseClass = Member->getBaseClass();
+        assert(BaseClass && "ActOnMemInitializers - neither field or base");
+        Diag(Member->getSourceLocation(),
+             diag::error_multiple_base_initialization)
+          << QualType(BaseClass, 0)
+          << Member->getSourceRange();
+      }
+      Diag(PrevMember->getSourceLocation(), diag::note_previous_initializer)
+        << 0;
+      err = true;
+    }
+
+    if (err)
+      return;
+  }
+
+  SetBaseOrMemberInitializers(Constructor,
+                      reinterpret_cast<CXXBaseOrMemberInitializer **>(MemInits),
+                      NumMemInits, false, AnyErrors);
+
+  if (Constructor->isDependentContext())
+    return;
+
+  if (Diags.getDiagnosticLevel(diag::warn_base_initialized) ==
+      Diagnostic::Ignored &&
+      Diags.getDiagnosticLevel(diag::warn_field_initialized) ==
+      Diagnostic::Ignored)
+    return;
+
+  // Also issue warning if order of ctor-initializer list does not match order
+  // of 1) base class declarations and 2) order of non-static data members.
+  llvm::SmallVector<const void*, 32> AllBaseOrMembers;
+
+  CXXRecordDecl *ClassDecl
+    = cast<CXXRecordDecl>(Constructor->getDeclContext());
+  // Push virtual bases before others.
+  for (CXXRecordDecl::base_class_iterator VBase =
+       ClassDecl->vbases_begin(),
+       E = ClassDecl->vbases_end(); VBase != E; ++VBase)
+    AllBaseOrMembers.push_back(GetKeyForBase(VBase->getType()));
+
+  for (CXXRecordDecl::base_class_iterator Base = ClassDecl->bases_begin(),
+       E = ClassDecl->bases_end(); Base != E; ++Base) {
+    // Virtuals are alread in the virtual base list and are constructed
+    // first.
+    if (Base->isVirtual())
+      continue;
+    AllBaseOrMembers.push_back(GetKeyForBase(Base->getType()));
+  }
+
+  for (CXXRecordDecl::field_iterator Field = ClassDecl->field_begin(),
+       E = ClassDecl->field_end(); Field != E; ++Field)
+    AllBaseOrMembers.push_back(GetKeyForTopLevelField(*Field));
+
+  int Last = AllBaseOrMembers.size();
+  int curIndex = 0;
+  CXXBaseOrMemberInitializer *PrevMember = 0;
+  for (unsigned i = 0; i < NumMemInits; i++) {
+    CXXBaseOrMemberInitializer *Member =
+      static_cast<CXXBaseOrMemberInitializer*>(MemInits[i]);
+    void *MemberInCtorList = GetKeyForMember(Member, true);
+
+    for (; curIndex < Last; curIndex++)
+      if (MemberInCtorList == AllBaseOrMembers[curIndex])
+        break;
+    if (curIndex == Last) {
+      assert(PrevMember && "Member not in member list?!");
+      // Initializer as specified in ctor-initializer list is out of order.
+      // Issue a warning diagnostic.
+      if (PrevMember->isBaseInitializer()) {
+        // Diagnostics is for an initialized base class.
+        Type *BaseClass = PrevMember->getBaseClass();
+        Diag(PrevMember->getSourceLocation(),
+             diag::warn_base_initialized)
+          << QualType(BaseClass, 0);
+      } else {
+        FieldDecl *Field = PrevMember->getMember();
+        Diag(PrevMember->getSourceLocation(),
+             diag::warn_field_initialized)
+          << Field->getNameAsString();
+      }
+      // Also the note!
+      if (FieldDecl *Field = Member->getMember())
+        Diag(Member->getSourceLocation(),
+             diag::note_fieldorbase_initialized_here) << 0
+          << Field->getNameAsString();
+      else {
+        Type *BaseClass = Member->getBaseClass();
+        Diag(Member->getSourceLocation(),
+             diag::note_fieldorbase_initialized_here) << 1
+          << QualType(BaseClass, 0);
+      }
+      for (curIndex = 0; curIndex < Last; curIndex++)
+        if (MemberInCtorList == AllBaseOrMembers[curIndex])
+          break;
+    }
+    PrevMember = Member;
+  }
+}
+
+void
+Sema::MarkBaseAndMemberDestructorsReferenced(CXXDestructorDecl *Destructor) {
+  // Ignore dependent destructors.
+  if (Destructor->isDependentContext())
+    return;
+  
+  CXXRecordDecl *ClassDecl = Destructor->getParent();
+
+  // Non-static data members.
+  for (CXXRecordDecl::field_iterator I = ClassDecl->field_begin(),
+       E = ClassDecl->field_end(); I != E; ++I) {
+    FieldDecl *Field = *I;
+    
+    QualType FieldType = Context.getBaseElementType(Field->getType());
+    
+    const RecordType* RT = FieldType->getAs<RecordType>();
+    if (!RT)
+      continue;
+    
+    CXXRecordDecl *FieldClassDecl = cast<CXXRecordDecl>(RT->getDecl());
+    if (FieldClassDecl->hasTrivialDestructor())
+      continue;
+
+    const CXXDestructorDecl *Dtor = FieldClassDecl->getDestructor(Context);
+    MarkDeclarationReferenced(Destructor->getLocation(),
+                              const_cast<CXXDestructorDecl*>(Dtor));
+  }
+
+  // Bases.
+  for (CXXRecordDecl::base_class_iterator Base = ClassDecl->bases_begin(),
+       E = ClassDecl->bases_end(); Base != E; ++Base) {
+    // Ignore virtual bases.
+    if (Base->isVirtual())
+      continue;
+
+    // Ignore trivial destructors.
+    CXXRecordDecl *BaseClassDecl
+      = cast<CXXRecordDecl>(Base->getType()->getAs<RecordType>()->getDecl());
+    if (BaseClassDecl->hasTrivialDestructor())
+      continue;
+    
+    const CXXDestructorDecl *Dtor = BaseClassDecl->getDestructor(Context);
+    MarkDeclarationReferenced(Destructor->getLocation(),
+                              const_cast<CXXDestructorDecl*>(Dtor));
+  }
+  
+  // Virtual bases.
+  for (CXXRecordDecl::base_class_iterator VBase = ClassDecl->vbases_begin(),
+       E = ClassDecl->vbases_end(); VBase != E; ++VBase) {
+    // Ignore trivial destructors.
+    CXXRecordDecl *BaseClassDecl
+      = cast<CXXRecordDecl>(VBase->getType()->getAs<RecordType>()->getDecl());
+    if (BaseClassDecl->hasTrivialDestructor())
+      continue;
+    
+    const CXXDestructorDecl *Dtor = BaseClassDecl->getDestructor(Context);
+    MarkDeclarationReferenced(Destructor->getLocation(),
+                              const_cast<CXXDestructorDecl*>(Dtor));
+  }
+}
+
+void Sema::ActOnDefaultCtorInitializers(DeclPtrTy CDtorDecl) {
+  if (!CDtorDecl)
+    return;
+
+  AdjustDeclIfTemplate(CDtorDecl);
+
+  if (CXXConstructorDecl *Constructor
+      = dyn_cast<CXXConstructorDecl>(CDtorDecl.getAs<Decl>()))
+    SetBaseOrMemberInitializers(Constructor, 0, 0, false, false);
+}
+
+namespace {
+  /// PureVirtualMethodCollector - traverses a class and its superclasses
+  /// and determines if it has any pure virtual methods.
+  class PureVirtualMethodCollector {
+    ASTContext &Context;
+
+  public:
+    typedef llvm::SmallVector<const CXXMethodDecl*, 8> MethodList;
+
+  private:
+    MethodList Methods;
+
+    void Collect(const CXXRecordDecl* RD, MethodList& Methods);
+
+  public:
+    PureVirtualMethodCollector(ASTContext &Ctx, const CXXRecordDecl* RD)
+      : Context(Ctx) {
+
+      MethodList List;
+      Collect(RD, List);
+
+      // Copy the temporary list to methods, and make sure to ignore any
+      // null entries.
+      for (size_t i = 0, e = List.size(); i != e; ++i) {
+        if (List[i])
+          Methods.push_back(List[i]);
+      }
+    }
+
+    bool empty() const { return Methods.empty(); }
+
+    MethodList::const_iterator methods_begin() { return Methods.begin(); }
+    MethodList::const_iterator methods_end() { return Methods.end(); }
+  };
+
+  void PureVirtualMethodCollector::Collect(const CXXRecordDecl* RD,
+                                           MethodList& Methods) {
+    // First, collect the pure virtual methods for the base classes.
+    for (CXXRecordDecl::base_class_const_iterator Base = RD->bases_begin(),
+         BaseEnd = RD->bases_end(); Base != BaseEnd; ++Base) {
+      if (const RecordType *RT = Base->getType()->getAs<RecordType>()) {
+        const CXXRecordDecl *BaseDecl = cast<CXXRecordDecl>(RT->getDecl());
+        if (BaseDecl && BaseDecl->isAbstract())
+          Collect(BaseDecl, Methods);
+      }
+    }
+
+    // Next, zero out any pure virtual methods that this class overrides.
+    typedef llvm::SmallPtrSet<const CXXMethodDecl*, 4> MethodSetTy;
+
+    MethodSetTy OverriddenMethods;
+    size_t MethodsSize = Methods.size();
+
+    for (RecordDecl::decl_iterator i = RD->decls_begin(), e = RD->decls_end();
+         i != e; ++i) {
+      // Traverse the record, looking for methods.
+      if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(*i)) {
+        // If the method is pure virtual, add it to the methods vector.
+        if (MD->isPure())
+          Methods.push_back(MD);
+
+        // Record all the overridden methods in our set.
+        for (CXXMethodDecl::method_iterator I = MD->begin_overridden_methods(),
+             E = MD->end_overridden_methods(); I != E; ++I) {
+          // Keep track of the overridden methods.
+          OverriddenMethods.insert(*I);
+        }
+      }
+    }
+
+    // Now go through the methods and zero out all the ones we know are
+    // overridden.
+    for (size_t i = 0, e = MethodsSize; i != e; ++i) {
+      if (OverriddenMethods.count(Methods[i]))
+        Methods[i] = 0;
+    }
+
+  }
+}
+
+
+bool Sema::RequireNonAbstractType(SourceLocation Loc, QualType T,
+                                  unsigned DiagID, AbstractDiagSelID SelID,
+                                  const CXXRecordDecl *CurrentRD) {
+  if (SelID == -1)
+    return RequireNonAbstractType(Loc, T,
+                                  PDiag(DiagID), CurrentRD);
+  else
+    return RequireNonAbstractType(Loc, T,
+                                  PDiag(DiagID) << SelID, CurrentRD);
+}
+
+bool Sema::RequireNonAbstractType(SourceLocation Loc, QualType T,
+                                  const PartialDiagnostic &PD,
+                                  const CXXRecordDecl *CurrentRD) {
+  if (!getLangOptions().CPlusPlus)
+    return false;
+
+  if (const ArrayType *AT = Context.getAsArrayType(T))
+    return RequireNonAbstractType(Loc, AT->getElementType(), PD,
+                                  CurrentRD);
+
+  if (const PointerType *PT = T->getAs<PointerType>()) {
+    // Find the innermost pointer type.
+    while (const PointerType *T = PT->getPointeeType()->getAs<PointerType>())
+      PT = T;
+
+    if (const ArrayType *AT = Context.getAsArrayType(PT->getPointeeType()))
+      return RequireNonAbstractType(Loc, AT->getElementType(), PD, CurrentRD);
+  }
+
+  const RecordType *RT = T->getAs<RecordType>();
+  if (!RT)
+    return false;
+
+  const CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl());
+
+  if (CurrentRD && CurrentRD != RD)
+    return false;
+
+  // FIXME: is this reasonable?  It matches current behavior, but....
+  if (!RD->getDefinition(Context))
+    return false;
+
+  if (!RD->isAbstract())
+    return false;
+
+  Diag(Loc, PD) << RD->getDeclName();
+
+  // Check if we've already emitted the list of pure virtual functions for this
+  // class.
+  if (PureVirtualClassDiagSet && PureVirtualClassDiagSet->count(RD))
+    return true;
+
+  PureVirtualMethodCollector Collector(Context, RD);
+
+  for (PureVirtualMethodCollector::MethodList::const_iterator I =
+       Collector.methods_begin(), E = Collector.methods_end(); I != E; ++I) {
+    const CXXMethodDecl *MD = *I;
+
+    Diag(MD->getLocation(), diag::note_pure_virtual_function) <<
+      MD->getDeclName();
+  }
+
+  if (!PureVirtualClassDiagSet)
+    PureVirtualClassDiagSet.reset(new RecordDeclSetTy);
+  PureVirtualClassDiagSet->insert(RD);
+
+  return true;
+}
+
+namespace {
+  class AbstractClassUsageDiagnoser
+    : public DeclVisitor<AbstractClassUsageDiagnoser, bool> {
+    Sema &SemaRef;
+    CXXRecordDecl *AbstractClass;
+
+    bool VisitDeclContext(const DeclContext *DC) {
+      bool Invalid = false;
+
+      for (CXXRecordDecl::decl_iterator I = DC->decls_begin(),
+           E = DC->decls_end(); I != E; ++I)
+        Invalid |= Visit(*I);
+
+      return Invalid;
+    }
+
+  public:
+    AbstractClassUsageDiagnoser(Sema& SemaRef, CXXRecordDecl *ac)
+      : SemaRef(SemaRef), AbstractClass(ac) {
+        Visit(SemaRef.Context.getTranslationUnitDecl());
+    }
+
+    bool VisitFunctionDecl(const FunctionDecl *FD) {
+      if (FD->isThisDeclarationADefinition()) {
+        // No need to do the check if we're in a definition, because it requires
+        // that the return/param types are complete.
+        // because that requires
+        return VisitDeclContext(FD);
+      }
+
+      // Check the return type.
+      QualType RTy = FD->getType()->getAs<FunctionType>()->getResultType();
+      bool Invalid =
+        SemaRef.RequireNonAbstractType(FD->getLocation(), RTy,
+                                       diag::err_abstract_type_in_decl,
+                                       Sema::AbstractReturnType,
+                                       AbstractClass);
+
+      for (FunctionDecl::param_const_iterator I = FD->param_begin(),
+           E = FD->param_end(); I != E; ++I) {
+        const ParmVarDecl *VD = *I;
+        Invalid |=
+          SemaRef.RequireNonAbstractType(VD->getLocation(),
+                                         VD->getOriginalType(),
+                                         diag::err_abstract_type_in_decl,
+                                         Sema::AbstractParamType,
+                                         AbstractClass);
+      }
+
+      return Invalid;
+    }
+
+    bool VisitDecl(const Decl* D) {
+      if (const DeclContext *DC = dyn_cast<DeclContext>(D))
+        return VisitDeclContext(DC);
+
+      return false;
+    }
+  };
+}
+
+/// \brief Perform semantic checks on a class definition that has been
+/// completing, introducing implicitly-declared members, checking for
+/// abstract types, etc.
+void Sema::CheckCompletedCXXClass(CXXRecordDecl *Record) {
+  if (!Record || Record->isInvalidDecl())
+    return;
+
+  if (!Record->isDependentType())
+    AddImplicitlyDeclaredMembersToClass(Record);
+  
+  if (Record->isInvalidDecl())
+    return;
+
+  // Set access bits correctly on the directly-declared conversions.
+  UnresolvedSetImpl *Convs = Record->getConversionFunctions();
+  for (UnresolvedSetIterator I = Convs->begin(), E = Convs->end(); I != E; ++I)
+    Convs->setAccess(I, (*I)->getAccess());
+
+  if (!Record->isAbstract()) {
+    // Collect all the pure virtual methods and see if this is an abstract
+    // class after all.
+    PureVirtualMethodCollector Collector(Context, Record);
+    if (!Collector.empty())
+      Record->setAbstract(true);
+  }
+
+  if (Record->isAbstract())
+    (void)AbstractClassUsageDiagnoser(*this, Record);
+}
+
+void Sema::ActOnFinishCXXMemberSpecification(Scope* S, SourceLocation RLoc,
+                                             DeclPtrTy TagDecl,
+                                             SourceLocation LBrac,
+                                             SourceLocation RBrac) {
+  if (!TagDecl)
+    return;
+
+  AdjustDeclIfTemplate(TagDecl);
+
+  ActOnFields(S, RLoc, TagDecl,
+              (DeclPtrTy*)FieldCollector->getCurFields(),
+              FieldCollector->getCurNumFields(), LBrac, RBrac, 0);
+
+  CheckCompletedCXXClass(
+                      dyn_cast_or_null<CXXRecordDecl>(TagDecl.getAs<Decl>()));
+}
+
+/// AddImplicitlyDeclaredMembersToClass - Adds any implicitly-declared
+/// special functions, such as the default constructor, copy
+/// constructor, or destructor, to the given C++ class (C++
+/// [special]p1).  This routine can only be executed just before the
+/// definition of the class is complete.
+void Sema::AddImplicitlyDeclaredMembersToClass(CXXRecordDecl *ClassDecl) {
+  CanQualType ClassType
+    = Context.getCanonicalType(Context.getTypeDeclType(ClassDecl));
+
+  // FIXME: Implicit declarations have exception specifications, which are
+  // the union of the specifications of the implicitly called functions.
+
+  if (!ClassDecl->hasUserDeclaredConstructor()) {
+    // C++ [class.ctor]p5:
+    //   A default constructor for a class X is a constructor of class X
+    //   that can be called without an argument. If there is no
+    //   user-declared constructor for class X, a default constructor is
+    //   implicitly declared. An implicitly-declared default constructor
+    //   is an inline public member of its class.
+    DeclarationName Name
+      = Context.DeclarationNames.getCXXConstructorName(ClassType);
+    CXXConstructorDecl *DefaultCon =
+      CXXConstructorDecl::Create(Context, ClassDecl,
+                                 ClassDecl->getLocation(), Name,
+                                 Context.getFunctionType(Context.VoidTy,
+                                                         0, 0, false, 0),
+                                 /*TInfo=*/0,
+                                 /*isExplicit=*/false,
+                                 /*isInline=*/true,
+                                 /*isImplicitlyDeclared=*/true);
+    DefaultCon->setAccess(AS_public);
+    DefaultCon->setImplicit();
+    DefaultCon->setTrivial(ClassDecl->hasTrivialConstructor());
+    ClassDecl->addDecl(DefaultCon);
+  }
+
+  if (!ClassDecl->hasUserDeclaredCopyConstructor()) {
+    // C++ [class.copy]p4:
+    //   If the class definition does not explicitly declare a copy
+    //   constructor, one is declared implicitly.
+
+    // C++ [class.copy]p5:
+    //   The implicitly-declared copy constructor for a class X will
+    //   have the form
+    //
+    //       X::X(const X&)
+    //
+    //   if
+    bool HasConstCopyConstructor = true;
+
+    //     -- each direct or virtual base class B of X has a copy
+    //        constructor whose first parameter is of type const B& or
+    //        const volatile B&, and
+    for (CXXRecordDecl::base_class_iterator Base = ClassDecl->bases_begin();
+         HasConstCopyConstructor && Base != ClassDecl->bases_end(); ++Base) {
+      const CXXRecordDecl *BaseClassDecl
+        = cast<CXXRecordDecl>(Base->getType()->getAs<RecordType>()->getDecl());
+      HasConstCopyConstructor
+        = BaseClassDecl->hasConstCopyConstructor(Context);
+    }
+
+    //     -- for all the nonstatic data members of X that are of a
+    //        class type M (or array thereof), each such class type
+    //        has a copy constructor whose first parameter is of type
+    //        const M& or const volatile M&.
+    for (CXXRecordDecl::field_iterator Field = ClassDecl->field_begin();
+         HasConstCopyConstructor && Field != ClassDecl->field_end();
+         ++Field) {
+      QualType FieldType = (*Field)->getType();
+      if (const ArrayType *Array = Context.getAsArrayType(FieldType))
+        FieldType = Array->getElementType();
+      if (const RecordType *FieldClassType = FieldType->getAs<RecordType>()) {
+        const CXXRecordDecl *FieldClassDecl
+          = cast<CXXRecordDecl>(FieldClassType->getDecl());
+        HasConstCopyConstructor
+          = FieldClassDecl->hasConstCopyConstructor(Context);
+      }
+    }
+
+    //   Otherwise, the implicitly declared copy constructor will have
+    //   the form
+    //
+    //       X::X(X&)
+    QualType ArgType = ClassType;
+    if (HasConstCopyConstructor)
+      ArgType = ArgType.withConst();
+    ArgType = Context.getLValueReferenceType(ArgType);
+
+    //   An implicitly-declared copy constructor is an inline public
+    //   member of its class.
+    DeclarationName Name
+      = Context.DeclarationNames.getCXXConstructorName(ClassType);
+    CXXConstructorDecl *CopyConstructor
+      = CXXConstructorDecl::Create(Context, ClassDecl,
+                                   ClassDecl->getLocation(), Name,
+                                   Context.getFunctionType(Context.VoidTy,
+                                                           &ArgType, 1,
+                                                           false, 0),
+                                   /*TInfo=*/0,
+                                   /*isExplicit=*/false,
+                                   /*isInline=*/true,
+                                   /*isImplicitlyDeclared=*/true);
+    CopyConstructor->setAccess(AS_public);
+    CopyConstructor->setImplicit();
+    CopyConstructor->setTrivial(ClassDecl->hasTrivialCopyConstructor());
+
+    // Add the parameter to the constructor.
+    ParmVarDecl *FromParam = ParmVarDecl::Create(Context, CopyConstructor,
+                                                 ClassDecl->getLocation(),
+                                                 /*IdentifierInfo=*/0,
+                                                 ArgType, /*TInfo=*/0,
+                                                 VarDecl::None, 0);
+    CopyConstructor->setParams(Context, &FromParam, 1);
+    ClassDecl->addDecl(CopyConstructor);
+  }
+
+  if (!ClassDecl->hasUserDeclaredCopyAssignment()) {
+    // Note: The following rules are largely analoguous to the copy
+    // constructor rules. Note that virtual bases are not taken into account
+    // for determining the argument type of the operator. Note also that
+    // operators taking an object instead of a reference are allowed.
+    //
+    // C++ [class.copy]p10:
+    //   If the class definition does not explicitly declare a copy
+    //   assignment operator, one is declared implicitly.
+    //   The implicitly-defined copy assignment operator for a class X
+    //   will have the form
+    //
+    //       X& X::operator=(const X&)
+    //
+    //   if
+    bool HasConstCopyAssignment = true;
+
+    //       -- each direct base class B of X has a copy assignment operator
+    //          whose parameter is of type const B&, const volatile B& or B,
+    //          and
+    for (CXXRecordDecl::base_class_iterator Base = ClassDecl->bases_begin();
+         HasConstCopyAssignment && Base != ClassDecl->bases_end(); ++Base) {
+      assert(!Base->getType()->isDependentType() &&
+            "Cannot generate implicit members for class with dependent bases.");
+      const CXXRecordDecl *BaseClassDecl
+        = cast<CXXRecordDecl>(Base->getType()->getAs<RecordType>()->getDecl());
+      const CXXMethodDecl *MD = 0;
+      HasConstCopyAssignment = BaseClassDecl->hasConstCopyAssignment(Context,
+                                                                     MD);
+    }
+
+    //       -- for all the nonstatic data members of X that are of a class
+    //          type M (or array thereof), each such class type has a copy
+    //          assignment operator whose parameter is of type const M&,
+    //          const volatile M& or M.
+    for (CXXRecordDecl::field_iterator Field = ClassDecl->field_begin();
+         HasConstCopyAssignment && Field != ClassDecl->field_end();
+         ++Field) {
+      QualType FieldType = (*Field)->getType();
+      if (const ArrayType *Array = Context.getAsArrayType(FieldType))
+        FieldType = Array->getElementType();
+      if (const RecordType *FieldClassType = FieldType->getAs<RecordType>()) {
+        const CXXRecordDecl *FieldClassDecl
+          = cast<CXXRecordDecl>(FieldClassType->getDecl());
+        const CXXMethodDecl *MD = 0;
+        HasConstCopyAssignment
+          = FieldClassDecl->hasConstCopyAssignment(Context, MD);
+      }
+    }
+
+    //   Otherwise, the implicitly declared copy assignment operator will
+    //   have the form
+    //
+    //       X& X::operator=(X&)
+    QualType ArgType = ClassType;
+    QualType RetType = Context.getLValueReferenceType(ArgType);
+    if (HasConstCopyAssignment)
+      ArgType = ArgType.withConst();
+    ArgType = Context.getLValueReferenceType(ArgType);
+
+    //   An implicitly-declared copy assignment operator is an inline public
+    //   member of its class.
+    DeclarationName Name =
+      Context.DeclarationNames.getCXXOperatorName(OO_Equal);
+    CXXMethodDecl *CopyAssignment =
+      CXXMethodDecl::Create(Context, ClassDecl, ClassDecl->getLocation(), Name,
+                            Context.getFunctionType(RetType, &ArgType, 1,
+                                                    false, 0),
+                            /*TInfo=*/0, /*isStatic=*/false, /*isInline=*/true);
+    CopyAssignment->setAccess(AS_public);
+    CopyAssignment->setImplicit();
+    CopyAssignment->setTrivial(ClassDecl->hasTrivialCopyAssignment());
+    CopyAssignment->setCopyAssignment(true);
+
+    // Add the parameter to the operator.
+    ParmVarDecl *FromParam = ParmVarDecl::Create(Context, CopyAssignment,
+                                                 ClassDecl->getLocation(),
+                                                 /*IdentifierInfo=*/0,
+                                                 ArgType, /*TInfo=*/0,
+                                                 VarDecl::None, 0);
+    CopyAssignment->setParams(Context, &FromParam, 1);
+
+    // Don't call addedAssignmentOperator. There is no way to distinguish an
+    // implicit from an explicit assignment operator.
+    ClassDecl->addDecl(CopyAssignment);
+    AddOverriddenMethods(ClassDecl, CopyAssignment);
+  }
+
+  if (!ClassDecl->hasUserDeclaredDestructor()) {
+    // C++ [class.dtor]p2:
+    //   If a class has no user-declared destructor, a destructor is
+    //   declared implicitly. An implicitly-declared destructor is an
+    //   inline public member of its class.
+    DeclarationName Name
+      = Context.DeclarationNames.getCXXDestructorName(ClassType);
+    CXXDestructorDecl *Destructor
+      = CXXDestructorDecl::Create(Context, ClassDecl,
+                                  ClassDecl->getLocation(), Name,
+                                  Context.getFunctionType(Context.VoidTy,
+                                                          0, 0, false, 0),
+                                  /*isInline=*/true,
+                                  /*isImplicitlyDeclared=*/true);
+    Destructor->setAccess(AS_public);
+    Destructor->setImplicit();
+    Destructor->setTrivial(ClassDecl->hasTrivialDestructor());
+    ClassDecl->addDecl(Destructor);
+    
+    AddOverriddenMethods(ClassDecl, Destructor);
+  }
+}
+
+void Sema::ActOnReenterTemplateScope(Scope *S, DeclPtrTy TemplateD) {
+  Decl *D = TemplateD.getAs<Decl>();
+  if (!D)
+    return;
+  
+  TemplateParameterList *Params = 0;
+  if (TemplateDecl *Template = dyn_cast<TemplateDecl>(D))
+    Params = Template->getTemplateParameters();
+  else if (ClassTemplatePartialSpecializationDecl *PartialSpec
+           = dyn_cast<ClassTemplatePartialSpecializationDecl>(D))
+    Params = PartialSpec->getTemplateParameters();
+  else
+    return;
+
+  for (TemplateParameterList::iterator Param = Params->begin(),
+                                    ParamEnd = Params->end();
+       Param != ParamEnd; ++Param) {
+    NamedDecl *Named = cast<NamedDecl>(*Param);
+    if (Named->getDeclName()) {
+      S->AddDecl(DeclPtrTy::make(Named));
+      IdResolver.AddDecl(Named);
+    }
+  }
+}
+
+void Sema::ActOnStartDelayedMemberDeclarations(Scope *S, DeclPtrTy RecordD) {
+  if (!RecordD) return;
+  AdjustDeclIfTemplate(RecordD);
+  CXXRecordDecl *Record = cast<CXXRecordDecl>(RecordD.getAs<Decl>());
+  PushDeclContext(S, Record);
+}
+
+void Sema::ActOnFinishDelayedMemberDeclarations(Scope *S, DeclPtrTy RecordD) {
+  if (!RecordD) return;
+  PopDeclContext();
+}
+
+/// ActOnStartDelayedCXXMethodDeclaration - We have completed
+/// parsing a top-level (non-nested) C++ class, and we are now
+/// parsing those parts of the given Method declaration that could
+/// not be parsed earlier (C++ [class.mem]p2), such as default
+/// arguments. This action should enter the scope of the given
+/// Method declaration as if we had just parsed the qualified method
+/// name. However, it should not bring the parameters into scope;
+/// that will be performed by ActOnDelayedCXXMethodParameter.
+void Sema::ActOnStartDelayedCXXMethodDeclaration(Scope *S, DeclPtrTy MethodD) {
+}
+
+/// ActOnDelayedCXXMethodParameter - We've already started a delayed
+/// C++ method declaration. We're (re-)introducing the given
+/// function parameter into scope for use in parsing later parts of
+/// the method declaration. For example, we could see an
+/// ActOnParamDefaultArgument event for this parameter.
+void Sema::ActOnDelayedCXXMethodParameter(Scope *S, DeclPtrTy ParamD) {
+  if (!ParamD)
+    return;
+
+  ParmVarDecl *Param = cast<ParmVarDecl>(ParamD.getAs<Decl>());
+
+  // If this parameter has an unparsed default argument, clear it out
+  // to make way for the parsed default argument.
+  if (Param->hasUnparsedDefaultArg())
+    Param->setDefaultArg(0);
+
+  S->AddDecl(DeclPtrTy::make(Param));
+  if (Param->getDeclName())
+    IdResolver.AddDecl(Param);
+}
+
+/// ActOnFinishDelayedCXXMethodDeclaration - We have finished
+/// processing the delayed method declaration for Method. The method
+/// declaration is now considered finished. There may be a separate
+/// ActOnStartOfFunctionDef action later (not necessarily
+/// immediately!) for this method, if it was also defined inside the
+/// class body.
+void Sema::ActOnFinishDelayedCXXMethodDeclaration(Scope *S, DeclPtrTy MethodD) {
+  if (!MethodD)
+    return;
+
+  AdjustDeclIfTemplate(MethodD);
+
+  FunctionDecl *Method = cast<FunctionDecl>(MethodD.getAs<Decl>());
+
+  // Now that we have our default arguments, check the constructor
+  // again. It could produce additional diagnostics or affect whether
+  // the class has implicitly-declared destructors, among other
+  // things.
+  if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(Method))
+    CheckConstructor(Constructor);
+
+  // Check the default arguments, which we may have added.
+  if (!Method->isInvalidDecl())
+    CheckCXXDefaultArguments(Method);
+}
+
+/// CheckConstructorDeclarator - Called by ActOnDeclarator to check
+/// the well-formedness of the constructor declarator @p D with type @p
+/// R. If there are any errors in the declarator, this routine will
+/// emit diagnostics and set the invalid bit to true.  In any case, the type
+/// will be updated to reflect a well-formed type for the constructor and
+/// returned.
+QualType Sema::CheckConstructorDeclarator(Declarator &D, QualType R,
+                                          FunctionDecl::StorageClass &SC) {
+  bool isVirtual = D.getDeclSpec().isVirtualSpecified();
+
+  // C++ [class.ctor]p3:
+  //   A constructor shall not be virtual (10.3) or static (9.4). A
+  //   constructor can be invoked for a const, volatile or const
+  //   volatile object. A constructor shall not be declared const,
+  //   volatile, or const volatile (9.3.2).
+  if (isVirtual) {
+    if (!D.isInvalidType())
+      Diag(D.getIdentifierLoc(), diag::err_constructor_cannot_be)
+        << "virtual" << SourceRange(D.getDeclSpec().getVirtualSpecLoc())
+        << SourceRange(D.getIdentifierLoc());
+    D.setInvalidType();
+  }
+  if (SC == FunctionDecl::Static) {
+    if (!D.isInvalidType())
+      Diag(D.getIdentifierLoc(), diag::err_constructor_cannot_be)
+        << "static" << SourceRange(D.getDeclSpec().getStorageClassSpecLoc())
+        << SourceRange(D.getIdentifierLoc());
+    D.setInvalidType();
+    SC = FunctionDecl::None;
+  }
+
+  DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun;
+  if (FTI.TypeQuals != 0) {
+    if (FTI.TypeQuals & Qualifiers::Const)
+      Diag(D.getIdentifierLoc(), diag::err_invalid_qualified_constructor)
+        << "const" << SourceRange(D.getIdentifierLoc());
+    if (FTI.TypeQuals & Qualifiers::Volatile)
+      Diag(D.getIdentifierLoc(), diag::err_invalid_qualified_constructor)
+        << "volatile" << SourceRange(D.getIdentifierLoc());
+    if (FTI.TypeQuals & Qualifiers::Restrict)
+      Diag(D.getIdentifierLoc(), diag::err_invalid_qualified_constructor)
+        << "restrict" << SourceRange(D.getIdentifierLoc());
+  }
+
+  // Rebuild the function type "R" without any type qualifiers (in
+  // case any of the errors above fired) and with "void" as the
+  // return type, since constructors don't have return types. We
+  // *always* have to do this, because GetTypeForDeclarator will
+  // put in a result type of "int" when none was specified.
+  const FunctionProtoType *Proto = R->getAs<FunctionProtoType>();
+  return Context.getFunctionType(Context.VoidTy, Proto->arg_type_begin(),
+                                 Proto->getNumArgs(),
+                                 Proto->isVariadic(), 0);
+}
+
+/// CheckConstructor - Checks a fully-formed constructor for
+/// well-formedness, issuing any diagnostics required. Returns true if
+/// the constructor declarator is invalid.
+void Sema::CheckConstructor(CXXConstructorDecl *Constructor) {
+  CXXRecordDecl *ClassDecl
+    = dyn_cast<CXXRecordDecl>(Constructor->getDeclContext());
+  if (!ClassDecl)
+    return Constructor->setInvalidDecl();
+
+  // C++ [class.copy]p3:
+  //   A declaration of a constructor for a class X is ill-formed if
+  //   its first parameter is of type (optionally cv-qualified) X and
+  //   either there are no other parameters or else all other
+  //   parameters have default arguments.
+  if (!Constructor->isInvalidDecl() &&
+      ((Constructor->getNumParams() == 1) ||
+       (Constructor->getNumParams() > 1 &&
+        Constructor->getParamDecl(1)->hasDefaultArg())) &&
+      Constructor->getTemplateSpecializationKind()
+                                              != TSK_ImplicitInstantiation) {
+    QualType ParamType = Constructor->getParamDecl(0)->getType();
+    QualType ClassTy = Context.getTagDeclType(ClassDecl);
+    if (Context.getCanonicalType(ParamType).getUnqualifiedType() == ClassTy) {
+      SourceLocation ParamLoc = Constructor->getParamDecl(0)->getLocation();
+      Diag(ParamLoc, diag::err_constructor_byvalue_arg)
+        << CodeModificationHint::CreateInsertion(ParamLoc, " const &");
+
+      // FIXME: Rather that making the constructor invalid, we should endeavor
+      // to fix the type.
+      Constructor->setInvalidDecl();
+    }
+  }
+
+  // Notify the class that we've added a constructor.
+  ClassDecl->addedConstructor(Context, Constructor);
+}
+
+/// CheckDestructor - Checks a fully-formed destructor for well-formedness, 
+/// issuing any diagnostics required. Returns true on error.
+bool Sema::CheckDestructor(CXXDestructorDecl *Destructor) {
+  CXXRecordDecl *RD = Destructor->getParent();
+  
+  if (Destructor->isVirtual()) {
+    SourceLocation Loc;
+    
+    if (!Destructor->isImplicit())
+      Loc = Destructor->getLocation();
+    else
+      Loc = RD->getLocation();
+    
+    // If we have a virtual destructor, look up the deallocation function
+    FunctionDecl *OperatorDelete = 0;
+    DeclarationName Name = 
+    Context.DeclarationNames.getCXXOperatorName(OO_Delete);
+    if (FindDeallocationFunction(Loc, RD, Name, OperatorDelete))
+      return true;
+    
+    Destructor->setOperatorDelete(OperatorDelete);
+  }
+  
+  return false;
+}
+
+static inline bool
+FTIHasSingleVoidArgument(DeclaratorChunk::FunctionTypeInfo &FTI) {
+  return (FTI.NumArgs == 1 && !FTI.isVariadic && FTI.ArgInfo[0].Ident == 0 &&
+          FTI.ArgInfo[0].Param &&
+          FTI.ArgInfo[0].Param.getAs<ParmVarDecl>()->getType()->isVoidType());
+}
+
+/// CheckDestructorDeclarator - Called by ActOnDeclarator to check
+/// the well-formednes of the destructor declarator @p D with type @p
+/// R. If there are any errors in the declarator, this routine will
+/// emit diagnostics and set the declarator to invalid.  Even if this happens,
+/// will be updated to reflect a well-formed type for the destructor and
+/// returned.
+QualType Sema::CheckDestructorDeclarator(Declarator &D,
+                                         FunctionDecl::StorageClass& SC) {
+  // C++ [class.dtor]p1:
+  //   [...] A typedef-name that names a class is a class-name
+  //   (7.1.3); however, a typedef-name that names a class shall not
+  //   be used as the identifier in the declarator for a destructor
+  //   declaration.
+  QualType DeclaratorType = GetTypeFromParser(D.getName().DestructorName);
+  if (isa<TypedefType>(DeclaratorType)) {
+    Diag(D.getIdentifierLoc(), diag::err_destructor_typedef_name)
+      << DeclaratorType;
+    D.setInvalidType();
+  }
+
+  // C++ [class.dtor]p2:
+  //   A destructor is used to destroy objects of its class type. A
+  //   destructor takes no parameters, and no return type can be
+  //   specified for it (not even void). The address of a destructor
+  //   shall not be taken. A destructor shall not be static. A
+  //   destructor can be invoked for a const, volatile or const
+  //   volatile object. A destructor shall not be declared const,
+  //   volatile or const volatile (9.3.2).
+  if (SC == FunctionDecl::Static) {
+    if (!D.isInvalidType())
+      Diag(D.getIdentifierLoc(), diag::err_destructor_cannot_be)
+        << "static" << SourceRange(D.getDeclSpec().getStorageClassSpecLoc())
+        << SourceRange(D.getIdentifierLoc());
+    SC = FunctionDecl::None;
+    D.setInvalidType();
+  }
+  if (D.getDeclSpec().hasTypeSpecifier() && !D.isInvalidType()) {
+    // Destructors don't have return types, but the parser will
+    // happily parse something like:
+    //
+    //   class X {
+    //     float ~X();
+    //   };
+    //
+    // The return type will be eliminated later.
+    Diag(D.getIdentifierLoc(), diag::err_destructor_return_type)
+      << SourceRange(D.getDeclSpec().getTypeSpecTypeLoc())
+      << SourceRange(D.getIdentifierLoc());
+  }
+
+  DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun;
+  if (FTI.TypeQuals != 0 && !D.isInvalidType()) {
+    if (FTI.TypeQuals & Qualifiers::Const)
+      Diag(D.getIdentifierLoc(), diag::err_invalid_qualified_destructor)
+        << "const" << SourceRange(D.getIdentifierLoc());
+    if (FTI.TypeQuals & Qualifiers::Volatile)
+      Diag(D.getIdentifierLoc(), diag::err_invalid_qualified_destructor)
+        << "volatile" << SourceRange(D.getIdentifierLoc());
+    if (FTI.TypeQuals & Qualifiers::Restrict)
+      Diag(D.getIdentifierLoc(), diag::err_invalid_qualified_destructor)
+        << "restrict" << SourceRange(D.getIdentifierLoc());
+    D.setInvalidType();
+  }
+
+  // Make sure we don't have any parameters.
+  if (FTI.NumArgs > 0 && !FTIHasSingleVoidArgument(FTI)) {
+    Diag(D.getIdentifierLoc(), diag::err_destructor_with_params);
+
+    // Delete the parameters.
+    FTI.freeArgs();
+    D.setInvalidType();
+  }
+
+  // Make sure the destructor isn't variadic.
+  if (FTI.isVariadic) {
+    Diag(D.getIdentifierLoc(), diag::err_destructor_variadic);
+    D.setInvalidType();
+  }
+
+  // Rebuild the function type "R" without any type qualifiers or
+  // parameters (in case any of the errors above fired) and with
+  // "void" as the return type, since destructors don't have return
+  // types. We *always* have to do this, because GetTypeForDeclarator
+  // will put in a result type of "int" when none was specified.
+  return Context.getFunctionType(Context.VoidTy, 0, 0, false, 0);
+}
+
+/// CheckConversionDeclarator - Called by ActOnDeclarator to check the
+/// well-formednes of the conversion function declarator @p D with
+/// type @p R. If there are any errors in the declarator, this routine
+/// will emit diagnostics and return true. Otherwise, it will return
+/// false. Either way, the type @p R will be updated to reflect a
+/// well-formed type for the conversion operator.
+void Sema::CheckConversionDeclarator(Declarator &D, QualType &R,
+                                     FunctionDecl::StorageClass& SC) {
+  // C++ [class.conv.fct]p1:
+  //   Neither parameter types nor return type can be specified. The
+  //   type of a conversion function (8.3.5) is "function taking no
+  //   parameter returning conversion-type-id."
+  if (SC == FunctionDecl::Static) {
+    if (!D.isInvalidType())
+      Diag(D.getIdentifierLoc(), diag::err_conv_function_not_member)
+        << "static" << SourceRange(D.getDeclSpec().getStorageClassSpecLoc())
+        << SourceRange(D.getIdentifierLoc());
+    D.setInvalidType();
+    SC = FunctionDecl::None;
+  }
+  if (D.getDeclSpec().hasTypeSpecifier() && !D.isInvalidType()) {
+    // Conversion functions don't have return types, but the parser will
+    // happily parse something like:
+    //
+    //   class X {
+    //     float operator bool();
+    //   };
+    //
+    // The return type will be changed later anyway.
+    Diag(D.getIdentifierLoc(), diag::err_conv_function_return_type)
+      << SourceRange(D.getDeclSpec().getTypeSpecTypeLoc())
+      << SourceRange(D.getIdentifierLoc());
+  }
+
+  // Make sure we don't have any parameters.
+  if (R->getAs<FunctionProtoType>()->getNumArgs() > 0) {
+    Diag(D.getIdentifierLoc(), diag::err_conv_function_with_params);
+
+    // Delete the parameters.
+    D.getTypeObject(0).Fun.freeArgs();
+    D.setInvalidType();
+  }
+
+  // Make sure the conversion function isn't variadic.
+  if (R->getAs<FunctionProtoType>()->isVariadic() && !D.isInvalidType()) {
+    Diag(D.getIdentifierLoc(), diag::err_conv_function_variadic);
+    D.setInvalidType();
+  }
+
+  // C++ [class.conv.fct]p4:
+  //   The conversion-type-id shall not represent a function type nor
+  //   an array type.
+  QualType ConvType = GetTypeFromParser(D.getName().ConversionFunctionId);
+  if (ConvType->isArrayType()) {
+    Diag(D.getIdentifierLoc(), diag::err_conv_function_to_array);
+    ConvType = Context.getPointerType(ConvType);
+    D.setInvalidType();
+  } else if (ConvType->isFunctionType()) {
+    Diag(D.getIdentifierLoc(), diag::err_conv_function_to_function);
+    ConvType = Context.getPointerType(ConvType);
+    D.setInvalidType();
+  }
+
+  // Rebuild the function type "R" without any parameters (in case any
+  // of the errors above fired) and with the conversion type as the
+  // return type.
+  R = Context.getFunctionType(ConvType, 0, 0, false,
+                              R->getAs<FunctionProtoType>()->getTypeQuals());
+
+  // C++0x explicit conversion operators.
+  if (D.getDeclSpec().isExplicitSpecified() && !getLangOptions().CPlusPlus0x)
+    Diag(D.getDeclSpec().getExplicitSpecLoc(),
+         diag::warn_explicit_conversion_functions)
+      << SourceRange(D.getDeclSpec().getExplicitSpecLoc());
+}
+
+/// ActOnConversionDeclarator - Called by ActOnDeclarator to complete
+/// the declaration of the given C++ conversion function. This routine
+/// is responsible for recording the conversion function in the C++
+/// class, if possible.
+Sema::DeclPtrTy Sema::ActOnConversionDeclarator(CXXConversionDecl *Conversion) {
+  assert(Conversion && "Expected to receive a conversion function declaration");
+
+  CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(Conversion->getDeclContext());
+
+  // Make sure we aren't redeclaring the conversion function.
+  QualType ConvType = Context.getCanonicalType(Conversion->getConversionType());
+
+  // C++ [class.conv.fct]p1:
+  //   [...] A conversion function is never used to convert a
+  //   (possibly cv-qualified) object to the (possibly cv-qualified)
+  //   same object type (or a reference to it), to a (possibly
+  //   cv-qualified) base class of that type (or a reference to it),
+  //   or to (possibly cv-qualified) void.
+  // FIXME: Suppress this warning if the conversion function ends up being a
+  // virtual function that overrides a virtual function in a base class.
+  QualType ClassType
+    = Context.getCanonicalType(Context.getTypeDeclType(ClassDecl));
+  if (const ReferenceType *ConvTypeRef = ConvType->getAs<ReferenceType>())
+    ConvType = ConvTypeRef->getPointeeType();
+  if (ConvType->isRecordType()) {
+    ConvType = Context.getCanonicalType(ConvType).getUnqualifiedType();
+    if (ConvType == ClassType)
+      Diag(Conversion->getLocation(), diag::warn_conv_to_self_not_used)
+        << ClassType;
+    else if (IsDerivedFrom(ClassType, ConvType))
+      Diag(Conversion->getLocation(), diag::warn_conv_to_base_not_used)
+        <<  ClassType << ConvType;
+  } else if (ConvType->isVoidType()) {
+    Diag(Conversion->getLocation(), diag::warn_conv_to_void_not_used)
+      << ClassType << ConvType;
+  }
+
+  if (Conversion->getPrimaryTemplate()) {
+    // ignore specializations
+  } else if (Conversion->getPreviousDeclaration()) {
+    if (FunctionTemplateDecl *ConversionTemplate
+                                  = Conversion->getDescribedFunctionTemplate()) {
+      if (ClassDecl->replaceConversion(
+                                   ConversionTemplate->getPreviousDeclaration(),
+                                       ConversionTemplate))
+        return DeclPtrTy::make(ConversionTemplate);
+    } else if (ClassDecl->replaceConversion(Conversion->getPreviousDeclaration(),
+                                            Conversion))
+      return DeclPtrTy::make(Conversion);
+    assert(Conversion->isInvalidDecl() && "Conversion should not get here.");
+  } else if (FunctionTemplateDecl *ConversionTemplate
+               = Conversion->getDescribedFunctionTemplate())
+    ClassDecl->addConversionFunction(ConversionTemplate);
+  else 
+    ClassDecl->addConversionFunction(Conversion);
+
+  return DeclPtrTy::make(Conversion);
+}
+
+//===----------------------------------------------------------------------===//
+// Namespace Handling
+//===----------------------------------------------------------------------===//
+
+/// ActOnStartNamespaceDef - This is called at the start of a namespace
+/// definition.
+Sema::DeclPtrTy Sema::ActOnStartNamespaceDef(Scope *NamespcScope,
+                                             SourceLocation IdentLoc,
+                                             IdentifierInfo *II,
+                                             SourceLocation LBrace,
+                                             AttributeList *AttrList) {
+  NamespaceDecl *Namespc =
+      NamespaceDecl::Create(Context, CurContext, IdentLoc, II);
+  Namespc->setLBracLoc(LBrace);
+
+  Scope *DeclRegionScope = NamespcScope->getParent();
+
+  ProcessDeclAttributeList(DeclRegionScope, Namespc, AttrList);
+
+  if (II) {
+    // C++ [namespace.def]p2:
+    // The identifier in an original-namespace-definition shall not have been
+    // previously defined in the declarative region in which the
+    // original-namespace-definition appears. The identifier in an
+    // original-namespace-definition is the name of the namespace. Subsequently
+    // in that declarative region, it is treated as an original-namespace-name.
+
+    NamedDecl *PrevDecl
+      = LookupSingleName(DeclRegionScope, II, LookupOrdinaryName,
+                         ForRedeclaration);
+
+    if (NamespaceDecl *OrigNS = dyn_cast_or_null<NamespaceDecl>(PrevDecl)) {
+      // This is an extended namespace definition.
+      // Attach this namespace decl to the chain of extended namespace
+      // definitions.
+      OrigNS->setNextNamespace(Namespc);
+      Namespc->setOriginalNamespace(OrigNS->getOriginalNamespace());
+
+      // Remove the previous declaration from the scope.
+      if (DeclRegionScope->isDeclScope(DeclPtrTy::make(OrigNS))) {
+        IdResolver.RemoveDecl(OrigNS);
+        DeclRegionScope->RemoveDecl(DeclPtrTy::make(OrigNS));
+      }
+    } else if (PrevDecl) {
+      // This is an invalid name redefinition.
+      Diag(Namespc->getLocation(), diag::err_redefinition_different_kind)
+       << Namespc->getDeclName();
+      Diag(PrevDecl->getLocation(), diag::note_previous_definition);
+      Namespc->setInvalidDecl();
+      // Continue on to push Namespc as current DeclContext and return it.
+    } else if (II->isStr("std") && 
+               CurContext->getLookupContext()->isTranslationUnit()) {
+      // This is the first "real" definition of the namespace "std", so update
+      // our cache of the "std" namespace to point at this definition.
+      if (StdNamespace) {
+        // We had already defined a dummy namespace "std". Link this new 
+        // namespace definition to the dummy namespace "std".
+        StdNamespace->setNextNamespace(Namespc);
+        StdNamespace->setLocation(IdentLoc);
+        Namespc->setOriginalNamespace(StdNamespace->getOriginalNamespace());
+      }
+      
+      // Make our StdNamespace cache point at the first real definition of the
+      // "std" namespace.
+      StdNamespace = Namespc;
+    }
+
+    PushOnScopeChains(Namespc, DeclRegionScope);
+  } else {
+    // Anonymous namespaces.
+    assert(Namespc->isAnonymousNamespace());
+    CurContext->addDecl(Namespc);
+
+    // Link the anonymous namespace into its parent.
+    NamespaceDecl *PrevDecl;
+    DeclContext *Parent = CurContext->getLookupContext();
+    if (TranslationUnitDecl *TU = dyn_cast<TranslationUnitDecl>(Parent)) {
+      PrevDecl = TU->getAnonymousNamespace();
+      TU->setAnonymousNamespace(Namespc);
+    } else {
+      NamespaceDecl *ND = cast<NamespaceDecl>(Parent);
+      PrevDecl = ND->getAnonymousNamespace();
+      ND->setAnonymousNamespace(Namespc);
+    }
+
+    // Link the anonymous namespace with its previous declaration.
+    if (PrevDecl) {
+      assert(PrevDecl->isAnonymousNamespace());
+      assert(!PrevDecl->getNextNamespace());
+      Namespc->setOriginalNamespace(PrevDecl->getOriginalNamespace());
+      PrevDecl->setNextNamespace(Namespc);
+    }
+
+    // C++ [namespace.unnamed]p1.  An unnamed-namespace-definition
+    //   behaves as if it were replaced by
+    //     namespace unique { /* empty body */ }
+    //     using namespace unique;
+    //     namespace unique { namespace-body }
+    //   where all occurrences of 'unique' in a translation unit are
+    //   replaced by the same identifier and this identifier differs
+    //   from all other identifiers in the entire program.
+
+    // We just create the namespace with an empty name and then add an
+    // implicit using declaration, just like the standard suggests.
+    //
+    // CodeGen enforces the "universally unique" aspect by giving all
+    // declarations semantically contained within an anonymous
+    // namespace internal linkage.
+
+    if (!PrevDecl) {
+      UsingDirectiveDecl* UD
+        = UsingDirectiveDecl::Create(Context, CurContext,
+                                     /* 'using' */ LBrace,
+                                     /* 'namespace' */ SourceLocation(),
+                                     /* qualifier */ SourceRange(),
+                                     /* NNS */ NULL,
+                                     /* identifier */ SourceLocation(),
+                                     Namespc,
+                                     /* Ancestor */ CurContext);
+      UD->setImplicit();
+      CurContext->addDecl(UD);
+    }
+  }
+
+  // Although we could have an invalid decl (i.e. the namespace name is a
+  // redefinition), push it as current DeclContext and try to continue parsing.
+  // FIXME: We should be able to push Namespc here, so that the each DeclContext
+  // for the namespace has the declarations that showed up in that particular
+  // namespace definition.
+  PushDeclContext(NamespcScope, Namespc);
+  return DeclPtrTy::make(Namespc);
+}
+
+/// getNamespaceDecl - Returns the namespace a decl represents. If the decl
+/// is a namespace alias, returns the namespace it points to.
+static inline NamespaceDecl *getNamespaceDecl(NamedDecl *D) {
+  if (NamespaceAliasDecl *AD = dyn_cast_or_null<NamespaceAliasDecl>(D))
+    return AD->getNamespace();
+  return dyn_cast_or_null<NamespaceDecl>(D);
+}
+
+/// ActOnFinishNamespaceDef - This callback is called after a namespace is
+/// exited. Decl is the DeclTy returned by ActOnStartNamespaceDef.
+void Sema::ActOnFinishNamespaceDef(DeclPtrTy D, SourceLocation RBrace) {
+  Decl *Dcl = D.getAs<Decl>();
+  NamespaceDecl *Namespc = dyn_cast_or_null<NamespaceDecl>(Dcl);
+  assert(Namespc && "Invalid parameter, expected NamespaceDecl");
+  Namespc->setRBracLoc(RBrace);
+  PopDeclContext();
+}
+
+Sema::DeclPtrTy Sema::ActOnUsingDirective(Scope *S,
+                                          SourceLocation UsingLoc,
+                                          SourceLocation NamespcLoc,
+                                          const CXXScopeSpec &SS,
+                                          SourceLocation IdentLoc,
+                                          IdentifierInfo *NamespcName,
+                                          AttributeList *AttrList) {
+  assert(!SS.isInvalid() && "Invalid CXXScopeSpec.");
+  assert(NamespcName && "Invalid NamespcName.");
+  assert(IdentLoc.isValid() && "Invalid NamespceName location.");
+  assert(S->getFlags() & Scope::DeclScope && "Invalid Scope.");
+
+  UsingDirectiveDecl *UDir = 0;
+
+  // Lookup namespace name.
+  LookupResult R(*this, NamespcName, IdentLoc, LookupNamespaceName);
+  LookupParsedName(R, S, &SS);
+  if (R.isAmbiguous())
+    return DeclPtrTy();
+
+  if (!R.empty()) {
+    NamedDecl *Named = R.getFoundDecl();
+    assert((isa<NamespaceDecl>(Named) || isa<NamespaceAliasDecl>(Named))
+        && "expected namespace decl");
+    // C++ [namespace.udir]p1:
+    //   A using-directive specifies that the names in the nominated
+    //   namespace can be used in the scope in which the
+    //   using-directive appears after the using-directive. During
+    //   unqualified name lookup (3.4.1), the names appear as if they
+    //   were declared in the nearest enclosing namespace which
+    //   contains both the using-directive and the nominated
+    //   namespace. [Note: in this context, "contains" means "contains
+    //   directly or indirectly". ]
+
+    // Find enclosing context containing both using-directive and
+    // nominated namespace.
+    NamespaceDecl *NS = getNamespaceDecl(Named);
+    DeclContext *CommonAncestor = cast<DeclContext>(NS);
+    while (CommonAncestor && !CommonAncestor->Encloses(CurContext))
+      CommonAncestor = CommonAncestor->getParent();
+
+    UDir = UsingDirectiveDecl::Create(Context, CurContext, UsingLoc, NamespcLoc,
+                                      SS.getRange(),
+                                      (NestedNameSpecifier *)SS.getScopeRep(),
+                                      IdentLoc, Named, CommonAncestor);
+    PushUsingDirective(S, UDir);
+  } else {
+    Diag(IdentLoc, diag::err_expected_namespace_name) << SS.getRange();
+  }
+
+  // FIXME: We ignore attributes for now.
+  delete AttrList;
+  return DeclPtrTy::make(UDir);
+}
+
+void Sema::PushUsingDirective(Scope *S, UsingDirectiveDecl *UDir) {
+  // If scope has associated entity, then using directive is at namespace
+  // or translation unit scope. We add UsingDirectiveDecls, into
+  // it's lookup structure.
+  if (DeclContext *Ctx = static_cast<DeclContext*>(S->getEntity()))
+    Ctx->addDecl(UDir);
+  else
+    // Otherwise it is block-sope. using-directives will affect lookup
+    // only to the end of scope.
+    S->PushUsingDirective(DeclPtrTy::make(UDir));
+}
+
+
+Sema::DeclPtrTy Sema::ActOnUsingDeclaration(Scope *S,
+                                            AccessSpecifier AS,
+                                            bool HasUsingKeyword,
+                                            SourceLocation UsingLoc,
+                                            const CXXScopeSpec &SS,
+                                            UnqualifiedId &Name,
+                                            AttributeList *AttrList,
+                                            bool IsTypeName,
+                                            SourceLocation TypenameLoc) {
+  assert(S->getFlags() & Scope::DeclScope && "Invalid Scope.");
+
+  switch (Name.getKind()) {
+  case UnqualifiedId::IK_Identifier:
+  case UnqualifiedId::IK_OperatorFunctionId:
+  case UnqualifiedId::IK_LiteralOperatorId:
+  case UnqualifiedId::IK_ConversionFunctionId:
+    break;
+      
+  case UnqualifiedId::IK_ConstructorName:
+  case UnqualifiedId::IK_ConstructorTemplateId:
+    // C++0x inherited constructors.
+    if (getLangOptions().CPlusPlus0x) break;
+
+    Diag(Name.getSourceRange().getBegin(), diag::err_using_decl_constructor)
+      << SS.getRange();
+    return DeclPtrTy();
+      
+  case UnqualifiedId::IK_DestructorName:
+    Diag(Name.getSourceRange().getBegin(), diag::err_using_decl_destructor)
+      << SS.getRange();
+    return DeclPtrTy();
+      
+  case UnqualifiedId::IK_TemplateId:
+    Diag(Name.getSourceRange().getBegin(), diag::err_using_decl_template_id)
+      << SourceRange(Name.TemplateId->LAngleLoc, Name.TemplateId->RAngleLoc);
+    return DeclPtrTy();
+  }
+  
+  DeclarationName TargetName = GetNameFromUnqualifiedId(Name);
+  if (!TargetName)
+    return DeclPtrTy();
+
+  // Warn about using declarations.
+  // TODO: store that the declaration was written without 'using' and
+  // talk about access decls instead of using decls in the
+  // diagnostics.
+  if (!HasUsingKeyword) {
+    UsingLoc = Name.getSourceRange().getBegin();
+    
+    Diag(UsingLoc, diag::warn_access_decl_deprecated)
+      << CodeModificationHint::CreateInsertion(SS.getRange().getBegin(),
+                                               "using ");
+  }
+
+  NamedDecl *UD = BuildUsingDeclaration(S, AS, UsingLoc, SS,
+                                        Name.getSourceRange().getBegin(),
+                                        TargetName, AttrList,
+                                        /* IsInstantiation */ false,
+                                        IsTypeName, TypenameLoc);
+  if (UD)
+    PushOnScopeChains(UD, S, /*AddToContext*/ false);
+
+  return DeclPtrTy::make(UD);
+}
+
+/// Determines whether to create a using shadow decl for a particular
+/// decl, given the set of decls existing prior to this using lookup.
+bool Sema::CheckUsingShadowDecl(UsingDecl *Using, NamedDecl *Orig,
+                                const LookupResult &Previous) {
+  // Diagnose finding a decl which is not from a base class of the
+  // current class.  We do this now because there are cases where this
+  // function will silently decide not to build a shadow decl, which
+  // will pre-empt further diagnostics.
+  //
+  // We don't need to do this in C++0x because we do the check once on
+  // the qualifier.
+  //
+  // FIXME: diagnose the following if we care enough:
+  //   struct A { int foo; };
+  //   struct B : A { using A::foo; };
+  //   template <class T> struct C : A {};
+  //   template <class T> struct D : C<T> { using B::foo; } // <---
+  // This is invalid (during instantiation) in C++03 because B::foo
+  // resolves to the using decl in B, which is not a base class of D<T>.
+  // We can't diagnose it immediately because C<T> is an unknown
+  // specialization.  The UsingShadowDecl in D<T> then points directly
+  // to A::foo, which will look well-formed when we instantiate.
+  // The right solution is to not collapse the shadow-decl chain.
+  if (!getLangOptions().CPlusPlus0x && CurContext->isRecord()) {
+    DeclContext *OrigDC = Orig->getDeclContext();
+
+    // Handle enums and anonymous structs.
+    if (isa<EnumDecl>(OrigDC)) OrigDC = OrigDC->getParent();
+    CXXRecordDecl *OrigRec = cast<CXXRecordDecl>(OrigDC);
+    while (OrigRec->isAnonymousStructOrUnion())
+      OrigRec = cast<CXXRecordDecl>(OrigRec->getDeclContext());
+
+    if (cast<CXXRecordDecl>(CurContext)->isProvablyNotDerivedFrom(OrigRec)) {
+      if (OrigDC == CurContext) {
+        Diag(Using->getLocation(),
+             diag::err_using_decl_nested_name_specifier_is_current_class)
+          << Using->getNestedNameRange();
+        Diag(Orig->getLocation(), diag::note_using_decl_target);
+        return true;
+      }
+
+      Diag(Using->getNestedNameRange().getBegin(),
+           diag::err_using_decl_nested_name_specifier_is_not_base_class)
+        << Using->getTargetNestedNameDecl()
+        << cast<CXXRecordDecl>(CurContext)
+        << Using->getNestedNameRange();
+      Diag(Orig->getLocation(), diag::note_using_decl_target);
+      return true;
+    }
+  }
+
+  if (Previous.empty()) return false;
+
+  NamedDecl *Target = Orig;
+  if (isa<UsingShadowDecl>(Target))
+    Target = cast<UsingShadowDecl>(Target)->getTargetDecl();
+
+  // If the target happens to be one of the previous declarations, we
+  // don't have a conflict.
+  // 
+  // FIXME: but we might be increasing its access, in which case we
+  // should redeclare it.
+  NamedDecl *NonTag = 0, *Tag = 0;
+  for (LookupResult::iterator I = Previous.begin(), E = Previous.end();
+         I != E; ++I) {
+    NamedDecl *D = (*I)->getUnderlyingDecl();
+    if (D->getCanonicalDecl() == Target->getCanonicalDecl())
+      return false;
+
+    (isa<TagDecl>(D) ? Tag : NonTag) = D;
+  }
+
+  if (Target->isFunctionOrFunctionTemplate()) {
+    FunctionDecl *FD;
+    if (isa<FunctionTemplateDecl>(Target))
+      FD = cast<FunctionTemplateDecl>(Target)->getTemplatedDecl();
+    else
+      FD = cast<FunctionDecl>(Target);
+
+    NamedDecl *OldDecl = 0;
+    switch (CheckOverload(FD, Previous, OldDecl)) {
+    case Ovl_Overload:
+      return false;
+
+    case Ovl_NonFunction:
+      Diag(Using->getLocation(), diag::err_using_decl_conflict);
+      break;
+      
+    // We found a decl with the exact signature.
+    case Ovl_Match:
+      if (isa<UsingShadowDecl>(OldDecl)) {
+        // Silently ignore the possible conflict.
+        return false;
+      }
+
+      // If we're in a record, we want to hide the target, so we
+      // return true (without a diagnostic) to tell the caller not to
+      // build a shadow decl.
+      if (CurContext->isRecord())
+        return true;
+
+      // If we're not in a record, this is an error.
+      Diag(Using->getLocation(), diag::err_using_decl_conflict);
+      break;
+    }
+
+    Diag(Target->getLocation(), diag::note_using_decl_target);
+    Diag(OldDecl->getLocation(), diag::note_using_decl_conflict);
+    return true;
+  }
+
+  // Target is not a function.
+
+  if (isa<TagDecl>(Target)) {
+    // No conflict between a tag and a non-tag.
+    if (!Tag) return false;
+
+    Diag(Using->getLocation(), diag::err_using_decl_conflict);
+    Diag(Target->getLocation(), diag::note_using_decl_target);
+    Diag(Tag->getLocation(), diag::note_using_decl_conflict);
+    return true;
+  }
+
+  // No conflict between a tag and a non-tag.
+  if (!NonTag) return false;
+
+  Diag(Using->getLocation(), diag::err_using_decl_conflict);
+  Diag(Target->getLocation(), diag::note_using_decl_target);
+  Diag(NonTag->getLocation(), diag::note_using_decl_conflict);
+  return true;
+}
+
+/// Builds a shadow declaration corresponding to a 'using' declaration.
+UsingShadowDecl *Sema::BuildUsingShadowDecl(Scope *S,
+                                            UsingDecl *UD,
+                                            NamedDecl *Orig) {
+
+  // If we resolved to another shadow declaration, just coalesce them.
+  NamedDecl *Target = Orig;
+  if (isa<UsingShadowDecl>(Target)) {
+    Target = cast<UsingShadowDecl>(Target)->getTargetDecl();
+    assert(!isa<UsingShadowDecl>(Target) && "nested shadow declaration");
+  }
+  
+  UsingShadowDecl *Shadow
+    = UsingShadowDecl::Create(Context, CurContext,
+                              UD->getLocation(), UD, Target);
+  UD->addShadowDecl(Shadow);
+
+  if (S)
+    PushOnScopeChains(Shadow, S);
+  else
+    CurContext->addDecl(Shadow);
+  Shadow->setAccess(UD->getAccess());
+
+  if (Orig->isInvalidDecl() || UD->isInvalidDecl())
+    Shadow->setInvalidDecl();
+
+  return Shadow;
+}
+
+/// Hides a using shadow declaration.  This is required by the current
+/// using-decl implementation when a resolvable using declaration in a
+/// class is followed by a declaration which would hide or override
+/// one or more of the using decl's targets; for example:
+///
+///   struct Base { void foo(int); };
+///   struct Derived : Base {
+///     using Base::foo;
+///     void foo(int);
+///   };
+///
+/// The governing language is C++03 [namespace.udecl]p12:
+///
+///   When a using-declaration brings names from a base class into a
+///   derived class scope, member functions in the derived class
+///   override and/or hide member functions with the same name and
+///   parameter types in a base class (rather than conflicting).
+///
+/// There are two ways to implement this:
+///   (1) optimistically create shadow decls when they're not hidden
+///       by existing declarations, or
+///   (2) don't create any shadow decls (or at least don't make them
+///       visible) until we've fully parsed/instantiated the class.
+/// The problem with (1) is that we might have to retroactively remove
+/// a shadow decl, which requires several O(n) operations because the
+/// decl structures are (very reasonably) not designed for removal.
+/// (2) avoids this but is very fiddly and phase-dependent.
+void Sema::HideUsingShadowDecl(Scope *S, UsingShadowDecl *Shadow) {
+  // Remove it from the DeclContext...
+  Shadow->getDeclContext()->removeDecl(Shadow);
+
+  // ...and the scope, if applicable...
+  if (S) {
+    S->RemoveDecl(DeclPtrTy::make(static_cast<Decl*>(Shadow)));
+    IdResolver.RemoveDecl(Shadow);
+  }
+
+  // ...and the using decl.
+  Shadow->getUsingDecl()->removeShadowDecl(Shadow);
+
+  // TODO: complain somehow if Shadow was used.  It shouldn't
+  // be possible for this to happen, because 
+}
+
+/// Builds a using declaration.
+///
+/// \param IsInstantiation - Whether this call arises from an
+///   instantiation of an unresolved using declaration.  We treat
+///   the lookup differently for these declarations.
+NamedDecl *Sema::BuildUsingDeclaration(Scope *S, AccessSpecifier AS,
+                                       SourceLocation UsingLoc,
+                                       const CXXScopeSpec &SS,
+                                       SourceLocation IdentLoc,
+                                       DeclarationName Name,
+                                       AttributeList *AttrList,
+                                       bool IsInstantiation,
+                                       bool IsTypeName,
+                                       SourceLocation TypenameLoc) {
+  assert(!SS.isInvalid() && "Invalid CXXScopeSpec.");
+  assert(IdentLoc.isValid() && "Invalid TargetName location.");
+
+  // FIXME: We ignore attributes for now.
+  delete AttrList;
+
+  if (SS.isEmpty()) {
+    Diag(IdentLoc, diag::err_using_requires_qualname);
+    return 0;
+  }
+
+  // Do the redeclaration lookup in the current scope.
+  LookupResult Previous(*this, Name, IdentLoc, LookupUsingDeclName,
+                        ForRedeclaration);
+  Previous.setHideTags(false);
+  if (S) {
+    LookupName(Previous, S);
+
+    // It is really dumb that we have to do this.
+    LookupResult::Filter F = Previous.makeFilter();
+    while (F.hasNext()) {
+      NamedDecl *D = F.next();
+      if (!isDeclInScope(D, CurContext, S))
+        F.erase();
+    }
+    F.done();
+  } else {
+    assert(IsInstantiation && "no scope in non-instantiation");
+    assert(CurContext->isRecord() && "scope not record in instantiation");
+    LookupQualifiedName(Previous, CurContext);
+  }
+
+  NestedNameSpecifier *NNS =
+    static_cast<NestedNameSpecifier *>(SS.getScopeRep());
+
+  // Check for invalid redeclarations.
+  if (CheckUsingDeclRedeclaration(UsingLoc, IsTypeName, SS, IdentLoc, Previous))
+    return 0;
+
+  // Check for bad qualifiers.
+  if (CheckUsingDeclQualifier(UsingLoc, SS, IdentLoc))
+    return 0;
+
+  DeclContext *LookupContext = computeDeclContext(SS);
+  NamedDecl *D;
+  if (!LookupContext) {
+    if (IsTypeName) {
+      // FIXME: not all declaration name kinds are legal here
+      D = UnresolvedUsingTypenameDecl::Create(Context, CurContext,
+                                              UsingLoc, TypenameLoc,
+                                              SS.getRange(), NNS,
+                                              IdentLoc, Name);
+    } else {
+      D = UnresolvedUsingValueDecl::Create(Context, CurContext,
+                                           UsingLoc, SS.getRange(), NNS,
+                                           IdentLoc, Name);
+    }
+  } else {
+    D = UsingDecl::Create(Context, CurContext, IdentLoc,
+                          SS.getRange(), UsingLoc, NNS, Name,
+                          IsTypeName);
+  }
+  D->setAccess(AS);
+  CurContext->addDecl(D);
+
+  if (!LookupContext) return D;
+  UsingDecl *UD = cast<UsingDecl>(D);
+
+  if (RequireCompleteDeclContext(SS)) {
+    UD->setInvalidDecl();
+    return UD;
+  }
+
+  // Look up the target name.
+
+  LookupResult R(*this, Name, IdentLoc, LookupOrdinaryName);
+
+  // Unlike most lookups, we don't always want to hide tag
+  // declarations: tag names are visible through the using declaration
+  // even if hidden by ordinary names, *except* in a dependent context
+  // where it's important for the sanity of two-phase lookup.
+  if (!IsInstantiation)
+    R.setHideTags(false);
+
+  LookupQualifiedName(R, LookupContext);
+
+  if (R.empty()) {
+    Diag(IdentLoc, diag::err_no_member) 
+      << Name << LookupContext << SS.getRange();
+    UD->setInvalidDecl();
+    return UD;
+  }
+
+  if (R.isAmbiguous()) {
+    UD->setInvalidDecl();
+    return UD;
+  }
+
+  if (IsTypeName) {
+    // If we asked for a typename and got a non-type decl, error out.
+    if (!R.getAsSingle<TypeDecl>()) {
+      Diag(IdentLoc, diag::err_using_typename_non_type);
+      for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I)
+        Diag((*I)->getUnderlyingDecl()->getLocation(),
+             diag::note_using_decl_target);
+      UD->setInvalidDecl();
+      return UD;
+    }
+  } else {
+    // If we asked for a non-typename and we got a type, error out,
+    // but only if this is an instantiation of an unresolved using
+    // decl.  Otherwise just silently find the type name.
+    if (IsInstantiation && R.getAsSingle<TypeDecl>()) {
+      Diag(IdentLoc, diag::err_using_dependent_value_is_type);
+      Diag(R.getFoundDecl()->getLocation(), diag::note_using_decl_target);
+      UD->setInvalidDecl();
+      return UD;
+    }
+  }
+
+  // C++0x N2914 [namespace.udecl]p6:
+  // A using-declaration shall not name a namespace.
+  if (R.getAsSingle<NamespaceDecl>()) {
+    Diag(IdentLoc, diag::err_using_decl_can_not_refer_to_namespace)
+      << SS.getRange();
+    UD->setInvalidDecl();
+    return UD;
+  }
+
+  for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I) {
+    if (!CheckUsingShadowDecl(UD, *I, Previous))
+      BuildUsingShadowDecl(S, UD, *I);
+  }
+
+  return UD;
+}
+
+/// Checks that the given using declaration is not an invalid
+/// redeclaration.  Note that this is checking only for the using decl
+/// itself, not for any ill-formedness among the UsingShadowDecls.
+bool Sema::CheckUsingDeclRedeclaration(SourceLocation UsingLoc,
+                                       bool isTypeName,
+                                       const CXXScopeSpec &SS,
+                                       SourceLocation NameLoc,
+                                       const LookupResult &Prev) {
+  // C++03 [namespace.udecl]p8:
+  // C++0x [namespace.udecl]p10:
+  //   A using-declaration is a declaration and can therefore be used
+  //   repeatedly where (and only where) multiple declarations are
+  //   allowed.
+  // That's only in file contexts.
+  if (CurContext->getLookupContext()->isFileContext())
+    return false;
+
+  NestedNameSpecifier *Qual
+    = static_cast<NestedNameSpecifier*>(SS.getScopeRep());
+
+  for (LookupResult::iterator I = Prev.begin(), E = Prev.end(); I != E; ++I) {
+    NamedDecl *D = *I;
+
+    bool DTypename;
+    NestedNameSpecifier *DQual;
+    if (UsingDecl *UD = dyn_cast<UsingDecl>(D)) {
+      DTypename = UD->isTypeName();
+      DQual = UD->getTargetNestedNameDecl();
+    } else if (UnresolvedUsingValueDecl *UD
+                 = dyn_cast<UnresolvedUsingValueDecl>(D)) {
+      DTypename = false;
+      DQual = UD->getTargetNestedNameSpecifier();
+    } else if (UnresolvedUsingTypenameDecl *UD
+                 = dyn_cast<UnresolvedUsingTypenameDecl>(D)) {
+      DTypename = true;
+      DQual = UD->getTargetNestedNameSpecifier();
+    } else continue;
+
+    // using decls differ if one says 'typename' and the other doesn't.
+    // FIXME: non-dependent using decls?
+    if (isTypeName != DTypename) continue;
+
+    // using decls differ if they name different scopes (but note that
+    // template instantiation can cause this check to trigger when it
+    // didn't before instantiation).
+    if (Context.getCanonicalNestedNameSpecifier(Qual) !=
+        Context.getCanonicalNestedNameSpecifier(DQual))
+      continue;
+
+    Diag(NameLoc, diag::err_using_decl_redeclaration) << SS.getRange();
+    Diag(D->getLocation(), diag::note_using_decl) << 1;
+    return true;
+  }
+
+  return false;
+}
+
+
+/// Checks that the given nested-name qualifier used in a using decl
+/// in the current context is appropriately related to the current
+/// scope.  If an error is found, diagnoses it and returns true.
+bool Sema::CheckUsingDeclQualifier(SourceLocation UsingLoc,
+                                   const CXXScopeSpec &SS,
+                                   SourceLocation NameLoc) {
+  DeclContext *NamedContext = computeDeclContext(SS);
+
+  if (!CurContext->isRecord()) {
+    // C++03 [namespace.udecl]p3:
+    // C++0x [namespace.udecl]p8:
+    //   A using-declaration for a class member shall be a member-declaration.
+
+    // If we weren't able to compute a valid scope, it must be a
+    // dependent class scope.
+    if (!NamedContext || NamedContext->isRecord()) {
+      Diag(NameLoc, diag::err_using_decl_can_not_refer_to_class_member)
+        << SS.getRange();
+      return true;
+    }
+
+    // Otherwise, everything is known to be fine.
+    return false;
+  }
+
+  // The current scope is a record.
+
+  // If the named context is dependent, we can't decide much.
+  if (!NamedContext) {
+    // FIXME: in C++0x, we can diagnose if we can prove that the
+    // nested-name-specifier does not refer to a base class, which is
+    // still possible in some cases.
+
+    // Otherwise we have to conservatively report that things might be
+    // okay.
+    return false;
+  }
+
+  if (!NamedContext->isRecord()) {
+    // Ideally this would point at the last name in the specifier,
+    // but we don't have that level of source info.
+    Diag(SS.getRange().getBegin(),
+         diag::err_using_decl_nested_name_specifier_is_not_class)
+      << (NestedNameSpecifier*) SS.getScopeRep() << SS.getRange();
+    return true;
+  }
+
+  if (getLangOptions().CPlusPlus0x) {
+    // C++0x [namespace.udecl]p3:
+    //   In a using-declaration used as a member-declaration, the
+    //   nested-name-specifier shall name a base class of the class
+    //   being defined.
+
+    if (cast<CXXRecordDecl>(CurContext)->isProvablyNotDerivedFrom(
+                                 cast<CXXRecordDecl>(NamedContext))) {
+      if (CurContext == NamedContext) {
+        Diag(NameLoc,
+             diag::err_using_decl_nested_name_specifier_is_current_class)
+          << SS.getRange();
+        return true;
+      }
+
+      Diag(SS.getRange().getBegin(),
+           diag::err_using_decl_nested_name_specifier_is_not_base_class)
+        << (NestedNameSpecifier*) SS.getScopeRep()
+        << cast<CXXRecordDecl>(CurContext)
+        << SS.getRange();
+      return true;
+    }
+
+    return false;
+  }
+
+  // C++03 [namespace.udecl]p4:
+  //   A using-declaration used as a member-declaration shall refer
+  //   to a member of a base class of the class being defined [etc.].
+
+  // Salient point: SS doesn't have to name a base class as long as
+  // lookup only finds members from base classes.  Therefore we can
+  // diagnose here only if we can prove that that can't happen,
+  // i.e. if the class hierarchies provably don't intersect.
+
+  // TODO: it would be nice if "definitely valid" results were cached
+  // in the UsingDecl and UsingShadowDecl so that these checks didn't
+  // need to be repeated.
+
+  struct UserData {
+    llvm::DenseSet<const CXXRecordDecl*> Bases;
+
+    static bool collect(const CXXRecordDecl *Base, void *OpaqueData) {
+      UserData *Data = reinterpret_cast<UserData*>(OpaqueData);
+      Data->Bases.insert(Base);
+      return true;
+    }
+
+    bool hasDependentBases(const CXXRecordDecl *Class) {
+      return !Class->forallBases(collect, this);
+    }
+
+    /// Returns true if the base is dependent or is one of the
+    /// accumulated base classes.
+    static bool doesNotContain(const CXXRecordDecl *Base, void *OpaqueData) {
+      UserData *Data = reinterpret_cast<UserData*>(OpaqueData);
+      return !Data->Bases.count(Base);
+    }
+
+    bool mightShareBases(const CXXRecordDecl *Class) {
+      return Bases.count(Class) || !Class->forallBases(doesNotContain, this);
+    }
+  };
+
+  UserData Data;
+
+  // Returns false if we find a dependent base.
+  if (Data.hasDependentBases(cast<CXXRecordDecl>(CurContext)))
+    return false;
+
+  // Returns false if the class has a dependent base or if it or one
+  // of its bases is present in the base set of the current context.
+  if (Data.mightShareBases(cast<CXXRecordDecl>(NamedContext)))
+    return false;
+
+  Diag(SS.getRange().getBegin(),
+       diag::err_using_decl_nested_name_specifier_is_not_base_class)
+    << (NestedNameSpecifier*) SS.getScopeRep()
+    << cast<CXXRecordDecl>(CurContext)
+    << SS.getRange();
+
+  return true;
+}
+
+Sema::DeclPtrTy Sema::ActOnNamespaceAliasDef(Scope *S,
+                                             SourceLocation NamespaceLoc,
+                                             SourceLocation AliasLoc,
+                                             IdentifierInfo *Alias,
+                                             const CXXScopeSpec &SS,
+                                             SourceLocation IdentLoc,
+                                             IdentifierInfo *Ident) {
+
+  // Lookup the namespace name.
+  LookupResult R(*this, Ident, IdentLoc, LookupNamespaceName);
+  LookupParsedName(R, S, &SS);
+
+  // Check if we have a previous declaration with the same name.
+  if (NamedDecl *PrevDecl
+        = LookupSingleName(S, Alias, LookupOrdinaryName, ForRedeclaration)) {
+    if (NamespaceAliasDecl *AD = dyn_cast<NamespaceAliasDecl>(PrevDecl)) {
+      // We already have an alias with the same name that points to the same
+      // namespace, so don't create a new one.
+      if (!R.isAmbiguous() && !R.empty() &&
+          AD->getNamespace() == getNamespaceDecl(R.getFoundDecl()))
+        return DeclPtrTy();
+    }
+
+    unsigned DiagID = isa<NamespaceDecl>(PrevDecl) ? diag::err_redefinition :
+      diag::err_redefinition_different_kind;
+    Diag(AliasLoc, DiagID) << Alias;
+    Diag(PrevDecl->getLocation(), diag::note_previous_definition);
+    return DeclPtrTy();
+  }
+
+  if (R.isAmbiguous())
+    return DeclPtrTy();
+
+  if (R.empty()) {
+    Diag(NamespaceLoc, diag::err_expected_namespace_name) << SS.getRange();
+    return DeclPtrTy();
+  }
+
+  NamespaceAliasDecl *AliasDecl =
+    NamespaceAliasDecl::Create(Context, CurContext, NamespaceLoc, AliasLoc,
+                               Alias, SS.getRange(),
+                               (NestedNameSpecifier *)SS.getScopeRep(),
+                               IdentLoc, R.getFoundDecl());
+
+  CurContext->addDecl(AliasDecl);
+  return DeclPtrTy::make(AliasDecl);
+}
+
+void Sema::DefineImplicitDefaultConstructor(SourceLocation CurrentLocation,
+                                            CXXConstructorDecl *Constructor) {
+  assert((Constructor->isImplicit() && Constructor->isDefaultConstructor() &&
+          !Constructor->isUsed()) &&
+    "DefineImplicitDefaultConstructor - call it for implicit default ctor");
+
+  CXXRecordDecl *ClassDecl
+    = cast<CXXRecordDecl>(Constructor->getDeclContext());
+  assert(ClassDecl && "DefineImplicitDefaultConstructor - invalid constructor");
+
+  DeclContext *PreviousContext = CurContext;
+  CurContext = Constructor;
+  if (SetBaseOrMemberInitializers(Constructor, 0, 0, true, false)) {
+    Diag(CurrentLocation, diag::note_member_synthesized_at) 
+      << CXXDefaultConstructor << Context.getTagDeclType(ClassDecl);
+    Constructor->setInvalidDecl();
+  } else {
+    Constructor->setUsed();
+  }
+  CurContext = PreviousContext;
+}
+
+void Sema::DefineImplicitDestructor(SourceLocation CurrentLocation,
+                                    CXXDestructorDecl *Destructor) {
+  assert((Destructor->isImplicit() && !Destructor->isUsed()) &&
+         "DefineImplicitDestructor - call it for implicit default dtor");
+  CXXRecordDecl *ClassDecl = Destructor->getParent();
+  assert(ClassDecl && "DefineImplicitDestructor - invalid destructor");
+
+  DeclContext *PreviousContext = CurContext;
+  CurContext = Destructor;
+
+  // C++ [class.dtor] p5
+  // Before the implicitly-declared default destructor for a class is
+  // implicitly defined, all the implicitly-declared default destructors
+  // for its base class and its non-static data members shall have been
+  // implicitly defined.
+  for (CXXRecordDecl::base_class_iterator Base = ClassDecl->bases_begin(),
+       E = ClassDecl->bases_end(); Base != E; ++Base) {
+    CXXRecordDecl *BaseClassDecl
+      = cast<CXXRecordDecl>(Base->getType()->getAs<RecordType>()->getDecl());
+    if (!BaseClassDecl->hasTrivialDestructor()) {
+      if (CXXDestructorDecl *BaseDtor =
+          const_cast<CXXDestructorDecl*>(BaseClassDecl->getDestructor(Context)))
+        MarkDeclarationReferenced(CurrentLocation, BaseDtor);
+      else
+        assert(false &&
+               "DefineImplicitDestructor - missing dtor in a base class");
+    }
+  }
+
+  for (CXXRecordDecl::field_iterator Field = ClassDecl->field_begin(),
+       E = ClassDecl->field_end(); Field != E; ++Field) {
+    QualType FieldType = Context.getCanonicalType((*Field)->getType());
+    if (const ArrayType *Array = Context.getAsArrayType(FieldType))
+      FieldType = Array->getElementType();
+    if (const RecordType *FieldClassType = FieldType->getAs<RecordType>()) {
+      CXXRecordDecl *FieldClassDecl
+        = cast<CXXRecordDecl>(FieldClassType->getDecl());
+      if (!FieldClassDecl->hasTrivialDestructor()) {
+        if (CXXDestructorDecl *FieldDtor =
+            const_cast<CXXDestructorDecl*>(
+                                        FieldClassDecl->getDestructor(Context)))
+          MarkDeclarationReferenced(CurrentLocation, FieldDtor);
+        else
+          assert(false &&
+          "DefineImplicitDestructor - missing dtor in class of a data member");
+      }
+    }
+  }
+  
+  // FIXME: If CheckDestructor fails, we should emit a note about where the
+  // implicit destructor was needed.
+  if (CheckDestructor(Destructor)) {
+    Diag(CurrentLocation, diag::note_member_synthesized_at) 
+      << CXXDestructor << Context.getTagDeclType(ClassDecl);
+
+    Destructor->setInvalidDecl();
+    CurContext = PreviousContext;
+
+    return;
+  }
+  CurContext = PreviousContext;
+
+  Destructor->setUsed();
+}
+
+void Sema::DefineImplicitOverloadedAssign(SourceLocation CurrentLocation,
+                                          CXXMethodDecl *MethodDecl) {
+  assert((MethodDecl->isImplicit() && MethodDecl->isOverloadedOperator() &&
+          MethodDecl->getOverloadedOperator() == OO_Equal &&
+          !MethodDecl->isUsed()) &&
+         "DefineImplicitOverloadedAssign - call it for implicit assignment op");
+
+  CXXRecordDecl *ClassDecl
+    = cast<CXXRecordDecl>(MethodDecl->getDeclContext());
+
+  DeclContext *PreviousContext = CurContext;
+  CurContext = MethodDecl;
+
+  // C++[class.copy] p12
+  // Before the implicitly-declared copy assignment operator for a class is
+  // implicitly defined, all implicitly-declared copy assignment operators
+  // for its direct base classes and its nonstatic data members shall have
+  // been implicitly defined.
+  bool err = false;
+  for (CXXRecordDecl::base_class_iterator Base = ClassDecl->bases_begin(),
+       E = ClassDecl->bases_end(); Base != E; ++Base) {
+    CXXRecordDecl *BaseClassDecl
+      = cast<CXXRecordDecl>(Base->getType()->getAs<RecordType>()->getDecl());
+    if (CXXMethodDecl *BaseAssignOpMethod =
+          getAssignOperatorMethod(CurrentLocation, MethodDecl->getParamDecl(0), 
+                                  BaseClassDecl))
+      MarkDeclarationReferenced(CurrentLocation, BaseAssignOpMethod);
+  }
+  for (CXXRecordDecl::field_iterator Field = ClassDecl->field_begin(),
+       E = ClassDecl->field_end(); Field != E; ++Field) {
+    QualType FieldType = Context.getCanonicalType((*Field)->getType());
+    if (const ArrayType *Array = Context.getAsArrayType(FieldType))
+      FieldType = Array->getElementType();
+    if (const RecordType *FieldClassType = FieldType->getAs<RecordType>()) {
+      CXXRecordDecl *FieldClassDecl
+        = cast<CXXRecordDecl>(FieldClassType->getDecl());
+      if (CXXMethodDecl *FieldAssignOpMethod =
+          getAssignOperatorMethod(CurrentLocation, MethodDecl->getParamDecl(0), 
+                                  FieldClassDecl))
+        MarkDeclarationReferenced(CurrentLocation, FieldAssignOpMethod);
+    } else if (FieldType->isReferenceType()) {
+      Diag(ClassDecl->getLocation(), diag::err_uninitialized_member_for_assign)
+      << Context.getTagDeclType(ClassDecl) << 0 << Field->getDeclName();
+      Diag(Field->getLocation(), diag::note_declared_at);
+      Diag(CurrentLocation, diag::note_first_required_here);
+      err = true;
+    } else if (FieldType.isConstQualified()) {
+      Diag(ClassDecl->getLocation(), diag::err_uninitialized_member_for_assign)
+      << Context.getTagDeclType(ClassDecl) << 1 << Field->getDeclName();
+      Diag(Field->getLocation(), diag::note_declared_at);
+      Diag(CurrentLocation, diag::note_first_required_here);
+      err = true;
+    }
+  }
+  if (!err)
+    MethodDecl->setUsed();
+
+  CurContext = PreviousContext;
+}
+
+CXXMethodDecl *
+Sema::getAssignOperatorMethod(SourceLocation CurrentLocation,
+                              ParmVarDecl *ParmDecl,
+                              CXXRecordDecl *ClassDecl) {
+  QualType LHSType = Context.getTypeDeclType(ClassDecl);
+  QualType RHSType(LHSType);
+  // If class's assignment operator argument is const/volatile qualified,
+  // look for operator = (const/volatile B&). Otherwise, look for
+  // operator = (B&).
+  RHSType = Context.getCVRQualifiedType(RHSType,
+                                     ParmDecl->getType().getCVRQualifiers());
+  ExprOwningPtr<Expr> LHS(this,  new (Context) DeclRefExpr(ParmDecl,
+                                                           LHSType,
+                                                           SourceLocation()));
+  ExprOwningPtr<Expr> RHS(this,  new (Context) DeclRefExpr(ParmDecl,
+                                                           RHSType,
+                                                           CurrentLocation));
+  Expr *Args[2] = { &*LHS, &*RHS };
+  OverloadCandidateSet CandidateSet(CurrentLocation);
+  AddMemberOperatorCandidates(clang::OO_Equal, SourceLocation(), Args, 2,
+                              CandidateSet);
+  OverloadCandidateSet::iterator Best;
+  if (BestViableFunction(CandidateSet, CurrentLocation, Best) == OR_Success)
+    return cast<CXXMethodDecl>(Best->Function);
+  assert(false &&
+         "getAssignOperatorMethod - copy assignment operator method not found");
+  return 0;
+}
+
+void Sema::DefineImplicitCopyConstructor(SourceLocation CurrentLocation,
+                                   CXXConstructorDecl *CopyConstructor,
+                                   unsigned TypeQuals) {
+  assert((CopyConstructor->isImplicit() &&
+          CopyConstructor->isCopyConstructor(TypeQuals) &&
+          !CopyConstructor->isUsed()) &&
+         "DefineImplicitCopyConstructor - call it for implicit copy ctor");
+
+  CXXRecordDecl *ClassDecl
+    = cast<CXXRecordDecl>(CopyConstructor->getDeclContext());
+  assert(ClassDecl && "DefineImplicitCopyConstructor - invalid constructor");
+
+  DeclContext *PreviousContext = CurContext;
+  CurContext = CopyConstructor;
+
+  // C++ [class.copy] p209
+  // Before the implicitly-declared copy constructor for a class is
+  // implicitly defined, all the implicitly-declared copy constructors
+  // for its base class and its non-static data members shall have been
+  // implicitly defined.
+  for (CXXRecordDecl::base_class_iterator Base = ClassDecl->bases_begin();
+       Base != ClassDecl->bases_end(); ++Base) {
+    CXXRecordDecl *BaseClassDecl
+      = cast<CXXRecordDecl>(Base->getType()->getAs<RecordType>()->getDecl());
+    if (CXXConstructorDecl *BaseCopyCtor =
+        BaseClassDecl->getCopyConstructor(Context, TypeQuals))
+      MarkDeclarationReferenced(CurrentLocation, BaseCopyCtor);
+  }
+  for (CXXRecordDecl::field_iterator Field = ClassDecl->field_begin(),
+                                  FieldEnd = ClassDecl->field_end();
+       Field != FieldEnd; ++Field) {
+    QualType FieldType = Context.getCanonicalType((*Field)->getType());
+    if (const ArrayType *Array = Context.getAsArrayType(FieldType))
+      FieldType = Array->getElementType();
+    if (const RecordType *FieldClassType = FieldType->getAs<RecordType>()) {
+      CXXRecordDecl *FieldClassDecl
+        = cast<CXXRecordDecl>(FieldClassType->getDecl());
+      if (CXXConstructorDecl *FieldCopyCtor =
+          FieldClassDecl->getCopyConstructor(Context, TypeQuals))
+        MarkDeclarationReferenced(CurrentLocation, FieldCopyCtor);
+    }
+  }
+  CopyConstructor->setUsed();
+
+  CurContext = PreviousContext;
+}
+
+Sema::OwningExprResult
+Sema::BuildCXXConstructExpr(SourceLocation ConstructLoc, QualType DeclInitType,
+                            CXXConstructorDecl *Constructor,
+                            MultiExprArg ExprArgs,
+                            bool RequiresZeroInit,
+                            bool BaseInitialization) {
+  bool Elidable = false;
+
+  // C++ [class.copy]p15:
+  //   Whenever a temporary class object is copied using a copy constructor, and
+  //   this object and the copy have the same cv-unqualified type, an
+  //   implementation is permitted to treat the original and the copy as two
+  //   different ways of referring to the same object and not perform a copy at
+  //   all, even if the class copy constructor or destructor have side effects.
+
+  // FIXME: Is this enough?
+  if (Constructor->isCopyConstructor()) {
+    Expr *E = ((Expr **)ExprArgs.get())[0];
+    if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E))
+      if (ICE->getCastKind() == CastExpr::CK_NoOp)
+        E = ICE->getSubExpr();
+    if (CXXFunctionalCastExpr *FCE = dyn_cast<CXXFunctionalCastExpr>(E))
+      E = FCE->getSubExpr();
+    while (CXXBindTemporaryExpr *BE = dyn_cast<CXXBindTemporaryExpr>(E))
+      E = BE->getSubExpr();
+    if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E))
+      if (ICE->getCastKind() == CastExpr::CK_NoOp)
+        E = ICE->getSubExpr();
+
+    if (CallExpr *CE = dyn_cast<CallExpr>(E))
+      Elidable = !CE->getCallReturnType()->isReferenceType();
+    else if (isa<CXXTemporaryObjectExpr>(E))
+      Elidable = true;
+    else if (isa<CXXConstructExpr>(E))
+      Elidable = true;
+  }
+
+  return BuildCXXConstructExpr(ConstructLoc, DeclInitType, Constructor,
+                               Elidable, move(ExprArgs), RequiresZeroInit,
+                               BaseInitialization);
+}
+
+/// BuildCXXConstructExpr - Creates a complete call to a constructor,
+/// including handling of its default argument expressions.
+Sema::OwningExprResult
+Sema::BuildCXXConstructExpr(SourceLocation ConstructLoc, QualType DeclInitType,
+                            CXXConstructorDecl *Constructor, bool Elidable,
+                            MultiExprArg ExprArgs,
+                            bool RequiresZeroInit,
+                            bool BaseInitialization) {
+  unsigned NumExprs = ExprArgs.size();
+  Expr **Exprs = (Expr **)ExprArgs.release();
+
+  MarkDeclarationReferenced(ConstructLoc, Constructor);
+  return Owned(CXXConstructExpr::Create(Context, DeclInitType, ConstructLoc,
+                                        Constructor, Elidable, Exprs, NumExprs, 
+                                        RequiresZeroInit, BaseInitialization));
+}
+
+bool Sema::InitializeVarWithConstructor(VarDecl *VD,
+                                        CXXConstructorDecl *Constructor,
+                                        MultiExprArg Exprs) {
+  OwningExprResult TempResult =
+    BuildCXXConstructExpr(VD->getLocation(), VD->getType(), Constructor,
+                          move(Exprs));
+  if (TempResult.isInvalid())
+    return true;
+
+  Expr *Temp = TempResult.takeAs<Expr>();
+  MarkDeclarationReferenced(VD->getLocation(), Constructor);
+  Temp = MaybeCreateCXXExprWithTemporaries(Temp);
+  VD->setInit(Context, Temp);
+
+  return false;
+}
+
+void Sema::FinalizeVarWithDestructor(VarDecl *VD, const RecordType *Record) {
+  CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(Record->getDecl());
+  if (!ClassDecl->hasTrivialDestructor()) {
+    CXXDestructorDecl *Destructor = ClassDecl->getDestructor(Context);
+    MarkDeclarationReferenced(VD->getLocation(), Destructor);
+    CheckDestructorAccess(VD->getLocation(), Record);
+  }
+}
+
+/// AddCXXDirectInitializerToDecl - This action is called immediately after
+/// ActOnDeclarator, when a C++ direct initializer is present.
+/// e.g: "int x(1);"
+void Sema::AddCXXDirectInitializerToDecl(DeclPtrTy Dcl,
+                                         SourceLocation LParenLoc,
+                                         MultiExprArg Exprs,
+                                         SourceLocation *CommaLocs,
+                                         SourceLocation RParenLoc) {
+  assert(Exprs.size() != 0 && Exprs.get() && "missing expressions");
+  Decl *RealDecl = Dcl.getAs<Decl>();
+
+  // If there is no declaration, there was an error parsing it.  Just ignore
+  // the initializer.
+  if (RealDecl == 0)
+    return;
+
+  VarDecl *VDecl = dyn_cast<VarDecl>(RealDecl);
+  if (!VDecl) {
+    Diag(RealDecl->getLocation(), diag::err_illegal_initializer);
+    RealDecl->setInvalidDecl();
+    return;
+  }
+
+  // We will represent direct-initialization similarly to copy-initialization:
+  //    int x(1);  -as-> int x = 1;
+  //    ClassType x(a,b,c); -as-> ClassType x = ClassType(a,b,c);
+  //
+  // Clients that want to distinguish between the two forms, can check for
+  // direct initializer using VarDecl::hasCXXDirectInitializer().
+  // A major benefit is that clients that don't particularly care about which
+  // exactly form was it (like the CodeGen) can handle both cases without
+  // special case code.
+
+  // If either the declaration has a dependent type or if any of the expressions
+  // is type-dependent, we represent the initialization via a ParenListExpr for
+  // later use during template instantiation.
+  if (VDecl->getType()->isDependentType() ||
+      Expr::hasAnyTypeDependentArguments((Expr **)Exprs.get(), Exprs.size())) {
+    // Let clients know that initialization was done with a direct initializer.
+    VDecl->setCXXDirectInitializer(true);
+
+    // Store the initialization expressions as a ParenListExpr.
+    unsigned NumExprs = Exprs.size();
+    VDecl->setInit(Context,
+                   new (Context) ParenListExpr(Context, LParenLoc,
+                                               (Expr **)Exprs.release(),
+                                               NumExprs, RParenLoc));
+    return;
+  }
+
+
+  // C++ 8.5p11:
+  // The form of initialization (using parentheses or '=') is generally
+  // insignificant, but does matter when the entity being initialized has a
+  // class type.
+  QualType DeclInitType = VDecl->getType();
+  if (const ArrayType *Array = Context.getAsArrayType(DeclInitType))
+    DeclInitType = Context.getBaseElementType(Array);
+
+  if (RequireCompleteType(VDecl->getLocation(), VDecl->getType(),
+                          diag::err_typecheck_decl_incomplete_type)) {
+    VDecl->setInvalidDecl();
+    return;
+  }
+
+  // The variable can not have an abstract class type.
+  if (RequireNonAbstractType(VDecl->getLocation(), VDecl->getType(),
+                             diag::err_abstract_type_in_decl,
+                             AbstractVariableType))
+    VDecl->setInvalidDecl();
+
+  const VarDecl *Def;
+  if ((Def = VDecl->getDefinition()) && Def != VDecl) {
+    Diag(VDecl->getLocation(), diag::err_redefinition)
+    << VDecl->getDeclName();
+    Diag(Def->getLocation(), diag::note_previous_definition);
+    VDecl->setInvalidDecl();
+    return;
+  }
+  
+  // Capture the variable that is being initialized and the style of
+  // initialization.
+  InitializedEntity Entity = InitializedEntity::InitializeVariable(VDecl);
+  
+  // FIXME: Poor source location information.
+  InitializationKind Kind
+    = InitializationKind::CreateDirect(VDecl->getLocation(),
+                                       LParenLoc, RParenLoc);
+  
+  InitializationSequence InitSeq(*this, Entity, Kind, 
+                                 (Expr**)Exprs.get(), Exprs.size());
+  OwningExprResult Result = InitSeq.Perform(*this, Entity, Kind, move(Exprs));
+  if (Result.isInvalid()) {
+    VDecl->setInvalidDecl();
+    return;
+  }
+  
+  Result = MaybeCreateCXXExprWithTemporaries(move(Result));
+  VDecl->setInit(Context, Result.takeAs<Expr>());
+  VDecl->setCXXDirectInitializer(true);
+
+  if (const RecordType *Record = VDecl->getType()->getAs<RecordType>())
+    FinalizeVarWithDestructor(VDecl, Record);
+}
+
+/// \brief Add the applicable constructor candidates for an initialization
+/// by constructor.
+static void AddConstructorInitializationCandidates(Sema &SemaRef,
+                                                   QualType ClassType,
+                                                   Expr **Args,
+                                                   unsigned NumArgs,
+                                                   InitializationKind Kind,
+                                           OverloadCandidateSet &CandidateSet) {
+  // C++ [dcl.init]p14:
+  //   If the initialization is direct-initialization, or if it is
+  //   copy-initialization where the cv-unqualified version of the
+  //   source type is the same class as, or a derived class of, the
+  //   class of the destination, constructors are considered. The
+  //   applicable constructors are enumerated (13.3.1.3), and the
+  //   best one is chosen through overload resolution (13.3). The
+  //   constructor so selected is called to initialize the object,
+  //   with the initializer expression(s) as its argument(s). If no
+  //   constructor applies, or the overload resolution is ambiguous,
+  //   the initialization is ill-formed.
+  const RecordType *ClassRec = ClassType->getAs<RecordType>();
+  assert(ClassRec && "Can only initialize a class type here");
+  
+  // FIXME: When we decide not to synthesize the implicitly-declared
+  // constructors, we'll need to make them appear here.
+
+  const CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(ClassRec->getDecl());
+  DeclarationName ConstructorName
+    = SemaRef.Context.DeclarationNames.getCXXConstructorName(
+              SemaRef.Context.getCanonicalType(ClassType).getUnqualifiedType());
+  DeclContext::lookup_const_iterator Con, ConEnd;
+  for (llvm::tie(Con, ConEnd) = ClassDecl->lookup(ConstructorName);
+       Con != ConEnd; ++Con) {
+    // Find the constructor (which may be a template).
+    CXXConstructorDecl *Constructor = 0;
+    FunctionTemplateDecl *ConstructorTmpl= dyn_cast<FunctionTemplateDecl>(*Con);
+    if (ConstructorTmpl)
+      Constructor
+      = cast<CXXConstructorDecl>(ConstructorTmpl->getTemplatedDecl());
+    else
+      Constructor = cast<CXXConstructorDecl>(*Con);
+    
+    if ((Kind.getKind() == InitializationKind::IK_Direct) ||
+        (Kind.getKind() == InitializationKind::IK_Value) ||
+        (Kind.getKind() == InitializationKind::IK_Copy &&
+         Constructor->isConvertingConstructor(/*AllowExplicit=*/false)) ||
+        ((Kind.getKind() == InitializationKind::IK_Default) && 
+         Constructor->isDefaultConstructor())) {
+      if (ConstructorTmpl)
+        SemaRef.AddTemplateOverloadCandidate(ConstructorTmpl,
+                                             ConstructorTmpl->getAccess(),
+                                             /*ExplicitArgs*/ 0,
+                                             Args, NumArgs, CandidateSet);
+      else
+        SemaRef.AddOverloadCandidate(Constructor, Constructor->getAccess(),
+                                     Args, NumArgs, CandidateSet);
+    }
+  }
+}
+
+/// \brief Attempt to perform initialization by constructor 
+/// (C++ [dcl.init]p14), which may occur as part of direct-initialization or 
+/// copy-initialization. 
+///
+/// This routine determines whether initialization by constructor is possible,
+/// but it does not emit any diagnostics in the case where the initialization
+/// is ill-formed.
+///
+/// \param ClassType the type of the object being initialized, which must have
+/// class type.
+///
+/// \param Args the arguments provided to initialize the object
+///
+/// \param NumArgs the number of arguments provided to initialize the object
+///
+/// \param Kind the type of initialization being performed
+///
+/// \returns the constructor used to initialize the object, if successful.
+/// Otherwise, emits a diagnostic and returns NULL.
+CXXConstructorDecl *
+Sema::TryInitializationByConstructor(QualType ClassType,
+                                     Expr **Args, unsigned NumArgs,
+                                     SourceLocation Loc,
+                                     InitializationKind Kind) {
+  // Build the overload candidate set
+  OverloadCandidateSet CandidateSet(Loc);
+  AddConstructorInitializationCandidates(*this, ClassType, Args, NumArgs, Kind,
+                                         CandidateSet);
+  
+  // Determine whether we found a constructor we can use.
+  OverloadCandidateSet::iterator Best;
+  switch (BestViableFunction(CandidateSet, Loc, Best)) {
+    case OR_Success:
+    case OR_Deleted:
+      // We found a constructor. Return it.
+      return cast<CXXConstructorDecl>(Best->Function);
+      
+    case OR_No_Viable_Function:
+    case OR_Ambiguous:
+      // Overload resolution failed. Return nothing.
+      return 0;
+  }
+  
+  // Silence GCC warning
+  return 0;
+}
+
+/// \brief Given a constructor and the set of arguments provided for the
+/// constructor, convert the arguments and add any required default arguments
+/// to form a proper call to this constructor.
+///
+/// \returns true if an error occurred, false otherwise.
+bool 
+Sema::CompleteConstructorCall(CXXConstructorDecl *Constructor,
+                              MultiExprArg ArgsPtr,
+                              SourceLocation Loc,                                    
+                     ASTOwningVector<&ActionBase::DeleteExpr> &ConvertedArgs) {
+  // FIXME: This duplicates a lot of code from Sema::ConvertArgumentsForCall.
+  unsigned NumArgs = ArgsPtr.size();
+  Expr **Args = (Expr **)ArgsPtr.get();
+
+  const FunctionProtoType *Proto 
+    = Constructor->getType()->getAs<FunctionProtoType>();
+  assert(Proto && "Constructor without a prototype?");
+  unsigned NumArgsInProto = Proto->getNumArgs();
+  
+  // If too few arguments are available, we'll fill in the rest with defaults.
+  if (NumArgs < NumArgsInProto)
+    ConvertedArgs.reserve(NumArgsInProto);
+  else
+    ConvertedArgs.reserve(NumArgs);
+
+  VariadicCallType CallType = 
+    Proto->isVariadic() ? VariadicConstructor : VariadicDoesNotApply;
+  llvm::SmallVector<Expr *, 8> AllArgs;
+  bool Invalid = GatherArgumentsForCall(Loc, Constructor,
+                                        Proto, 0, Args, NumArgs, AllArgs, 
+                                        CallType);
+  for (unsigned i =0, size = AllArgs.size(); i < size; i++)
+    ConvertedArgs.push_back(AllArgs[i]);
+  return Invalid;
+}
+
+/// CompareReferenceRelationship - Compare the two types T1 and T2 to
+/// determine whether they are reference-related,
+/// reference-compatible, reference-compatible with added
+/// qualification, or incompatible, for use in C++ initialization by
+/// reference (C++ [dcl.ref.init]p4). Neither type can be a reference
+/// type, and the first type (T1) is the pointee type of the reference
+/// type being initialized.
+Sema::ReferenceCompareResult
+Sema::CompareReferenceRelationship(SourceLocation Loc,
+                                   QualType OrigT1, QualType OrigT2,
+                                   bool& DerivedToBase) {
+  assert(!OrigT1->isReferenceType() &&
+    "T1 must be the pointee type of the reference type");
+  assert(!OrigT2->isReferenceType() && "T2 cannot be a reference type");
+
+  QualType T1 = Context.getCanonicalType(OrigT1);
+  QualType T2 = Context.getCanonicalType(OrigT2);
+  Qualifiers T1Quals, T2Quals;
+  QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals);
+  QualType UnqualT2 = Context.getUnqualifiedArrayType(T2, T2Quals);
+
+  // C++ [dcl.init.ref]p4:
+  //   Given types "cv1 T1" and "cv2 T2," "cv1 T1" is
+  //   reference-related to "cv2 T2" if T1 is the same type as T2, or
+  //   T1 is a base class of T2.
+  if (UnqualT1 == UnqualT2)
+    DerivedToBase = false;
+  else if (!RequireCompleteType(Loc, OrigT1, PDiag()) &&
+           !RequireCompleteType(Loc, OrigT2, PDiag()) &&
+           IsDerivedFrom(UnqualT2, UnqualT1))
+    DerivedToBase = true;
+  else
+    return Ref_Incompatible;
+
+  // At this point, we know that T1 and T2 are reference-related (at
+  // least).
+
+  // If the type is an array type, promote the element qualifiers to the type
+  // for comparison.
+  if (isa<ArrayType>(T1) && T1Quals)
+    T1 = Context.getQualifiedType(UnqualT1, T1Quals);
+  if (isa<ArrayType>(T2) && T2Quals)
+    T2 = Context.getQualifiedType(UnqualT2, T2Quals);
+
+  // C++ [dcl.init.ref]p4:
+  //   "cv1 T1" is reference-compatible with "cv2 T2" if T1 is
+  //   reference-related to T2 and cv1 is the same cv-qualification
+  //   as, or greater cv-qualification than, cv2. For purposes of
+  //   overload resolution, cases for which cv1 is greater
+  //   cv-qualification than cv2 are identified as
+  //   reference-compatible with added qualification (see 13.3.3.2).
+  if (T1Quals.getCVRQualifiers() == T2Quals.getCVRQualifiers())
+    return Ref_Compatible;
+  else if (T1.isMoreQualifiedThan(T2))
+    return Ref_Compatible_With_Added_Qualification;
+  else
+    return Ref_Related;
+}
+
+/// CheckReferenceInit - Check the initialization of a reference
+/// variable with the given initializer (C++ [dcl.init.ref]). Init is
+/// the initializer (either a simple initializer or an initializer
+/// list), and DeclType is the type of the declaration. When ICS is
+/// non-null, this routine will compute the implicit conversion
+/// sequence according to C++ [over.ics.ref] and will not produce any
+/// diagnostics; when ICS is null, it will emit diagnostics when any
+/// errors are found. Either way, a return value of true indicates
+/// that there was a failure, a return value of false indicates that
+/// the reference initialization succeeded.
+///
+/// When @p SuppressUserConversions, user-defined conversions are
+/// suppressed.
+/// When @p AllowExplicit, we also permit explicit user-defined
+/// conversion functions.
+/// When @p ForceRValue, we unconditionally treat the initializer as an rvalue.
+/// When @p IgnoreBaseAccess, we don't do access control on to-base conversion.
+/// This is used when this is called from a C-style cast.
+bool
+Sema::CheckReferenceInit(Expr *&Init, QualType DeclType,
+                         SourceLocation DeclLoc,
+                         bool SuppressUserConversions,
+                         bool AllowExplicit, bool ForceRValue,
+                         ImplicitConversionSequence *ICS,
+                         bool IgnoreBaseAccess) {
+  assert(DeclType->isReferenceType() && "Reference init needs a reference");
+
+  QualType T1 = DeclType->getAs<ReferenceType>()->getPointeeType();
+  QualType T2 = Init->getType();
+
+  // If the initializer is the address of an overloaded function, try
+  // to resolve the overloaded function. If all goes well, T2 is the
+  // type of the resulting function.
+  if (Context.getCanonicalType(T2) == Context.OverloadTy) {
+    FunctionDecl *Fn = ResolveAddressOfOverloadedFunction(Init, DeclType,
+                                                          ICS != 0);
+    if (Fn) {
+      // Since we're performing this reference-initialization for
+      // real, update the initializer with the resulting function.
+      if (!ICS) {
+        if (DiagnoseUseOfDecl(Fn, DeclLoc))
+          return true; 
+
+        Init = FixOverloadedFunctionReference(Init, Fn);
+      }
+
+      T2 = Fn->getType();
+    }
+  }
+
+  // Compute some basic properties of the types and the initializer.
+  bool isRValRef = DeclType->isRValueReferenceType();
+  bool DerivedToBase = false;
+  Expr::isLvalueResult InitLvalue = ForceRValue ? Expr::LV_InvalidExpression :
+                                                  Init->isLvalue(Context);
+  ReferenceCompareResult RefRelationship
+    = CompareReferenceRelationship(DeclLoc, T1, T2, DerivedToBase);
+
+  // Most paths end in a failed conversion.
+  if (ICS) {
+    ICS->setBad();
+    ICS->Bad.init(BadConversionSequence::no_conversion, Init, DeclType);
+  }
+
+  // C++ [dcl.init.ref]p5:
+  //   A reference to type "cv1 T1" is initialized by an expression
+  //   of type "cv2 T2" as follows:
+
+  //     -- If the initializer expression
+
+  // Rvalue references cannot bind to lvalues (N2812).
+  // There is absolutely no situation where they can. In particular, note that
+  // this is ill-formed, even if B has a user-defined conversion to A&&:
+  //   B b;
+  //   A&& r = b;
+  if (isRValRef && InitLvalue == Expr::LV_Valid) {
+    if (!ICS)
+      Diag(DeclLoc, diag::err_lvalue_to_rvalue_ref)
+        << Init->getSourceRange();
+    return true;
+  }
+
+  bool BindsDirectly = false;
+  //       -- is an lvalue (but is not a bit-field), and "cv1 T1" is
+  //          reference-compatible with "cv2 T2," or
+  //
+  // Note that the bit-field check is skipped if we are just computing
+  // the implicit conversion sequence (C++ [over.best.ics]p2).
+  if (InitLvalue == Expr::LV_Valid && (ICS || !Init->getBitField()) &&
+      RefRelationship >= Ref_Compatible_With_Added_Qualification) {
+    BindsDirectly = true;
+
+    if (ICS) {
+      // C++ [over.ics.ref]p1:
+      //   When a parameter of reference type binds directly (8.5.3)
+      //   to an argument expression, the implicit conversion sequence
+      //   is the identity conversion, unless the argument expression
+      //   has a type that is a derived class of the parameter type,
+      //   in which case the implicit conversion sequence is a
+      //   derived-to-base Conversion (13.3.3.1).
+      ICS->setStandard();
+      ICS->Standard.First = ICK_Identity;
+      ICS->Standard.Second = DerivedToBase? ICK_Derived_To_Base : ICK_Identity;
+      ICS->Standard.Third = ICK_Identity;
+      ICS->Standard.FromTypePtr = T2.getAsOpaquePtr();
+      ICS->Standard.setToType(0, T2);
+      ICS->Standard.setToType(1, T1);
+      ICS->Standard.setToType(2, T1);
+      ICS->Standard.ReferenceBinding = true;
+      ICS->Standard.DirectBinding = true;
+      ICS->Standard.RRefBinding = false;
+      ICS->Standard.CopyConstructor = 0;
+
+      // Nothing more to do: the inaccessibility/ambiguity check for
+      // derived-to-base conversions is suppressed when we're
+      // computing the implicit conversion sequence (C++
+      // [over.best.ics]p2).
+      return false;
+    } else {
+      // Perform the conversion.
+      CastExpr::CastKind CK = CastExpr::CK_NoOp;
+      if (DerivedToBase)
+        CK = CastExpr::CK_DerivedToBase;
+      else if(CheckExceptionSpecCompatibility(Init, T1))
+        return true;
+      ImpCastExprToType(Init, T1, CK, /*isLvalue=*/true);
+    }
+  }
+
+  //       -- has a class type (i.e., T2 is a class type) and can be
+  //          implicitly converted to an lvalue of type "cv3 T3,"
+  //          where "cv1 T1" is reference-compatible with "cv3 T3"
+  //          92) (this conversion is selected by enumerating the
+  //          applicable conversion functions (13.3.1.6) and choosing
+  //          the best one through overload resolution (13.3)),
+  if (!isRValRef && !SuppressUserConversions && T2->isRecordType() &&
+      !RequireCompleteType(DeclLoc, T2, 0)) {
+    CXXRecordDecl *T2RecordDecl
+      = dyn_cast<CXXRecordDecl>(T2->getAs<RecordType>()->getDecl());
+
+    OverloadCandidateSet CandidateSet(DeclLoc);
+    const UnresolvedSetImpl *Conversions
+      = T2RecordDecl->getVisibleConversionFunctions();
+    for (UnresolvedSetImpl::iterator I = Conversions->begin(),
+           E = Conversions->end(); I != E; ++I) {
+      NamedDecl *D = *I;
+      CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(D->getDeclContext());
+      if (isa<UsingShadowDecl>(D))
+        D = cast<UsingShadowDecl>(D)->getTargetDecl();
+
+      FunctionTemplateDecl *ConvTemplate
+        = dyn_cast<FunctionTemplateDecl>(D);
+      CXXConversionDecl *Conv;
+      if (ConvTemplate)
+        Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl());
+      else
+        Conv = cast<CXXConversionDecl>(D);
+      
+      // If the conversion function doesn't return a reference type,
+      // it can't be considered for this conversion.
+      if (Conv->getConversionType()->isLValueReferenceType() &&
+          (AllowExplicit || !Conv->isExplicit())) {
+        if (ConvTemplate)
+          AddTemplateConversionCandidate(ConvTemplate, I.getAccess(), ActingDC,
+                                         Init, DeclType, CandidateSet);
+        else
+          AddConversionCandidate(Conv, I.getAccess(), ActingDC, Init,
+                                 DeclType, CandidateSet);
+      }
+    }
+
+    OverloadCandidateSet::iterator Best;
+    switch (BestViableFunction(CandidateSet, DeclLoc, Best)) {
+    case OR_Success:
+      // This is a direct binding.
+      BindsDirectly = true;
+
+      if (ICS) {
+        // C++ [over.ics.ref]p1:
+        //
+        //   [...] If the parameter binds directly to the result of
+        //   applying a conversion function to the argument
+        //   expression, the implicit conversion sequence is a
+        //   user-defined conversion sequence (13.3.3.1.2), with the
+        //   second standard conversion sequence either an identity
+        //   conversion or, if the conversion function returns an
+        //   entity of a type that is a derived class of the parameter
+        //   type, a derived-to-base Conversion.
+        ICS->setUserDefined();
+        ICS->UserDefined.Before = Best->Conversions[0].Standard;
+        ICS->UserDefined.After = Best->FinalConversion;
+        ICS->UserDefined.ConversionFunction = Best->Function;
+        ICS->UserDefined.EllipsisConversion = false;
+        assert(ICS->UserDefined.After.ReferenceBinding &&
+               ICS->UserDefined.After.DirectBinding &&
+               "Expected a direct reference binding!");
+        return false;
+      } else {
+        OwningExprResult InitConversion =
+          BuildCXXCastArgument(DeclLoc, QualType(),
+                               CastExpr::CK_UserDefinedConversion,
+                               cast<CXXMethodDecl>(Best->Function), 
+                               Owned(Init));
+        Init = InitConversion.takeAs<Expr>();
+
+        if (CheckExceptionSpecCompatibility(Init, T1))
+          return true;
+        ImpCastExprToType(Init, T1, CastExpr::CK_UserDefinedConversion, 
+                          /*isLvalue=*/true);
+      }
+      break;
+
+    case OR_Ambiguous:
+      if (ICS) {
+        ICS->setAmbiguous();
+        for (OverloadCandidateSet::iterator Cand = CandidateSet.begin();
+             Cand != CandidateSet.end(); ++Cand)
+          if (Cand->Viable)
+            ICS->Ambiguous.addConversion(Cand->Function);
+        break;
+      }
+      Diag(DeclLoc, diag::err_ref_init_ambiguous) << DeclType << Init->getType()
+            << Init->getSourceRange();
+      PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, &Init, 1);
+      return true;
+
+    case OR_No_Viable_Function:
+    case OR_Deleted:
+      // There was no suitable conversion, or we found a deleted
+      // conversion; continue with other checks.
+      break;
+    }
+  }
+
+  if (BindsDirectly) {
+    // C++ [dcl.init.ref]p4:
+    //   [...] In all cases where the reference-related or
+    //   reference-compatible relationship of two types is used to
+    //   establish the validity of a reference binding, and T1 is a
+    //   base class of T2, a program that necessitates such a binding
+    //   is ill-formed if T1 is an inaccessible (clause 11) or
+    //   ambiguous (10.2) base class of T2.
+    //
+    // Note that we only check this condition when we're allowed to
+    // complain about errors, because we should not be checking for
+    // ambiguity (or inaccessibility) unless the reference binding
+    // actually happens.
+    if (DerivedToBase)
+      return CheckDerivedToBaseConversion(T2, T1, DeclLoc,
+                                          Init->getSourceRange(),
+                                          IgnoreBaseAccess);
+    else
+      return false;
+  }
+
+  //     -- Otherwise, the reference shall be to a non-volatile const
+  //        type (i.e., cv1 shall be const), or the reference shall be an
+  //        rvalue reference and the initializer expression shall be an rvalue.
+  if (!isRValRef && T1.getCVRQualifiers() != Qualifiers::Const) {
+    if (!ICS)
+      Diag(DeclLoc, diag::err_not_reference_to_const_init)
+        << T1.isVolatileQualified()
+        << T1 << int(InitLvalue != Expr::LV_Valid)
+        << T2 << Init->getSourceRange();
+    return true;
+  }
+
+  //       -- If the initializer expression is an rvalue, with T2 a
+  //          class type, and "cv1 T1" is reference-compatible with
+  //          "cv2 T2," the reference is bound in one of the
+  //          following ways (the choice is implementation-defined):
+  //
+  //          -- The reference is bound to the object represented by
+  //             the rvalue (see 3.10) or to a sub-object within that
+  //             object.
+  //
+  //          -- A temporary of type "cv1 T2" [sic] is created, and
+  //             a constructor is called to copy the entire rvalue
+  //             object into the temporary. The reference is bound to
+  //             the temporary or to a sub-object within the
+  //             temporary.
+  //
+  //          The constructor that would be used to make the copy
+  //          shall be callable whether or not the copy is actually
+  //          done.
+  //
+  // Note that C++0x [dcl.init.ref]p5 takes away this implementation
+  // freedom, so we will always take the first option and never build
+  // a temporary in this case. FIXME: We will, however, have to check
+  // for the presence of a copy constructor in C++98/03 mode.
+  if (InitLvalue != Expr::LV_Valid && T2->isRecordType() &&
+      RefRelationship >= Ref_Compatible_With_Added_Qualification) {
+    if (ICS) {
+      ICS->setStandard();
+      ICS->Standard.First = ICK_Identity;
+      ICS->Standard.Second = DerivedToBase? ICK_Derived_To_Base : ICK_Identity;
+      ICS->Standard.Third = ICK_Identity;
+      ICS->Standard.FromTypePtr = T2.getAsOpaquePtr();
+      ICS->Standard.setToType(0, T2);
+      ICS->Standard.setToType(1, T1);
+      ICS->Standard.setToType(2, T1);
+      ICS->Standard.ReferenceBinding = true;
+      ICS->Standard.DirectBinding = false;
+      ICS->Standard.RRefBinding = isRValRef;
+      ICS->Standard.CopyConstructor = 0;
+    } else {
+      CastExpr::CastKind CK = CastExpr::CK_NoOp;
+      if (DerivedToBase)
+        CK = CastExpr::CK_DerivedToBase;
+      else if(CheckExceptionSpecCompatibility(Init, T1))
+        return true;
+      ImpCastExprToType(Init, T1, CK, /*isLvalue=*/false);
+    }
+    return false;
+  }
+
+  //       -- Otherwise, a temporary of type "cv1 T1" is created and
+  //          initialized from the initializer expression using the
+  //          rules for a non-reference copy initialization (8.5). The
+  //          reference is then bound to the temporary. If T1 is
+  //          reference-related to T2, cv1 must be the same
+  //          cv-qualification as, or greater cv-qualification than,
+  //          cv2; otherwise, the program is ill-formed.
+  if (RefRelationship == Ref_Related) {
+    // If cv1 == cv2 or cv1 is a greater cv-qualified than cv2, then
+    // we would be reference-compatible or reference-compatible with
+    // added qualification. But that wasn't the case, so the reference
+    // initialization fails.
+    if (!ICS)
+      Diag(DeclLoc, diag::err_reference_init_drops_quals)
+        << T1 << int(InitLvalue != Expr::LV_Valid)
+        << T2 << Init->getSourceRange();
+    return true;
+  }
+
+  // If at least one of the types is a class type, the types are not
+  // related, and we aren't allowed any user conversions, the
+  // reference binding fails. This case is important for breaking
+  // recursion, since TryImplicitConversion below will attempt to
+  // create a temporary through the use of a copy constructor.
+  if (SuppressUserConversions && RefRelationship == Ref_Incompatible &&
+      (T1->isRecordType() || T2->isRecordType())) {
+    if (!ICS)
+      Diag(DeclLoc, diag::err_typecheck_convert_incompatible)
+        << DeclType << Init->getType() << AA_Initializing << Init->getSourceRange();
+    return true;
+  }
+
+  // Actually try to convert the initializer to T1.
+  if (ICS) {
+    // C++ [over.ics.ref]p2:
+    //
+    //   When a parameter of reference type is not bound directly to
+    //   an argument expression, the conversion sequence is the one
+    //   required to convert the argument expression to the
+    //   underlying type of the reference according to
+    //   13.3.3.1. Conceptually, this conversion sequence corresponds
+    //   to copy-initializing a temporary of the underlying type with
+    //   the argument expression. Any difference in top-level
+    //   cv-qualification is subsumed by the initialization itself
+    //   and does not constitute a conversion.
+    *ICS = TryImplicitConversion(Init, T1, SuppressUserConversions,
+                                 /*AllowExplicit=*/false,
+                                 /*ForceRValue=*/false,
+                                 /*InOverloadResolution=*/false);
+
+    // Of course, that's still a reference binding.
+    if (ICS->isStandard()) {
+      ICS->Standard.ReferenceBinding = true;
+      ICS->Standard.RRefBinding = isRValRef;
+    } else if (ICS->isUserDefined()) {
+      ICS->UserDefined.After.ReferenceBinding = true;
+      ICS->UserDefined.After.RRefBinding = isRValRef;
+    }
+    return ICS->isBad();
+  } else {
+    ImplicitConversionSequence Conversions;
+    bool badConversion = PerformImplicitConversion(Init, T1, AA_Initializing, 
+                                                   false, false, 
+                                                   Conversions);
+    if (badConversion) {
+      if (Conversions.isAmbiguous()) {
+        Diag(DeclLoc, 
+             diag::err_lvalue_to_rvalue_ambig_ref) << Init->getSourceRange();
+        for (int j = Conversions.Ambiguous.conversions().size()-1; 
+             j >= 0; j--) {
+          FunctionDecl *Func = Conversions.Ambiguous.conversions()[j];
+          NoteOverloadCandidate(Func);
+        }
+      }
+      else {
+        if (isRValRef)
+          Diag(DeclLoc, diag::err_lvalue_to_rvalue_ref) 
+            << Init->getSourceRange();
+        else
+          Diag(DeclLoc, diag::err_invalid_initialization)
+            << DeclType << Init->getType() << Init->getSourceRange();
+      }
+    }
+    return badConversion;
+  }
+}
+
+static inline bool
+CheckOperatorNewDeleteDeclarationScope(Sema &SemaRef, 
+                                       const FunctionDecl *FnDecl) {
+  const DeclContext *DC = FnDecl->getDeclContext()->getLookupContext();
+  if (isa<NamespaceDecl>(DC)) {
+    return SemaRef.Diag(FnDecl->getLocation(), 
+                        diag::err_operator_new_delete_declared_in_namespace)
+      << FnDecl->getDeclName();
+  }
+  
+  if (isa<TranslationUnitDecl>(DC) && 
+      FnDecl->getStorageClass() == FunctionDecl::Static) {
+    return SemaRef.Diag(FnDecl->getLocation(),
+                        diag::err_operator_new_delete_declared_static)
+      << FnDecl->getDeclName();
+  }
+  
+  return false;
+}
+
+static inline bool
+CheckOperatorNewDeleteTypes(Sema &SemaRef, const FunctionDecl *FnDecl,
+                            CanQualType ExpectedResultType,
+                            CanQualType ExpectedFirstParamType,
+                            unsigned DependentParamTypeDiag,
+                            unsigned InvalidParamTypeDiag) {
+  QualType ResultType = 
+    FnDecl->getType()->getAs<FunctionType>()->getResultType();
+
+  // Check that the result type is not dependent.
+  if (ResultType->isDependentType())
+    return SemaRef.Diag(FnDecl->getLocation(),
+                        diag::err_operator_new_delete_dependent_result_type)
+    << FnDecl->getDeclName() << ExpectedResultType;
+
+  // Check that the result type is what we expect.
+  if (SemaRef.Context.getCanonicalType(ResultType) != ExpectedResultType)
+    return SemaRef.Diag(FnDecl->getLocation(),
+                        diag::err_operator_new_delete_invalid_result_type) 
+    << FnDecl->getDeclName() << ExpectedResultType;
+  
+  // A function template must have at least 2 parameters.
+  if (FnDecl->getDescribedFunctionTemplate() && FnDecl->getNumParams() < 2)
+    return SemaRef.Diag(FnDecl->getLocation(),
+                      diag::err_operator_new_delete_template_too_few_parameters)
+        << FnDecl->getDeclName();
+  
+  // The function decl must have at least 1 parameter.
+  if (FnDecl->getNumParams() == 0)
+    return SemaRef.Diag(FnDecl->getLocation(),
+                        diag::err_operator_new_delete_too_few_parameters)
+      << FnDecl->getDeclName();
+ 
+  // Check the the first parameter type is not dependent.
+  QualType FirstParamType = FnDecl->getParamDecl(0)->getType();
+  if (FirstParamType->isDependentType())
+    return SemaRef.Diag(FnDecl->getLocation(), DependentParamTypeDiag)
+      << FnDecl->getDeclName() << ExpectedFirstParamType;
+
+  // Check that the first parameter type is what we expect.
+  if (SemaRef.Context.getCanonicalType(FirstParamType).getUnqualifiedType() != 
+      ExpectedFirstParamType)
+    return SemaRef.Diag(FnDecl->getLocation(), InvalidParamTypeDiag)
+    << FnDecl->getDeclName() << ExpectedFirstParamType;
+  
+  return false;
+}
+
+static bool
+CheckOperatorNewDeclaration(Sema &SemaRef, const FunctionDecl *FnDecl) {
+  // C++ [basic.stc.dynamic.allocation]p1:
+  //   A program is ill-formed if an allocation function is declared in a
+  //   namespace scope other than global scope or declared static in global 
+  //   scope.
+  if (CheckOperatorNewDeleteDeclarationScope(SemaRef, FnDecl))
+    return true;
+
+  CanQualType SizeTy = 
+    SemaRef.Context.getCanonicalType(SemaRef.Context.getSizeType());
+
+  // C++ [basic.stc.dynamic.allocation]p1:
+  //  The return type shall be void*. The first parameter shall have type 
+  //  std::size_t.
+  if (CheckOperatorNewDeleteTypes(SemaRef, FnDecl, SemaRef.Context.VoidPtrTy, 
+                                  SizeTy,
+                                  diag::err_operator_new_dependent_param_type,
+                                  diag::err_operator_new_param_type))
+    return true;
+
+  // C++ [basic.stc.dynamic.allocation]p1:
+  //  The first parameter shall not have an associated default argument.
+  if (FnDecl->getParamDecl(0)->hasDefaultArg())
+    return SemaRef.Diag(FnDecl->getLocation(),
+                        diag::err_operator_new_default_arg)
+      << FnDecl->getDeclName() << FnDecl->getParamDecl(0)->getDefaultArgRange();
+
+  return false;
+}
+
+static bool
+CheckOperatorDeleteDeclaration(Sema &SemaRef, const FunctionDecl *FnDecl) {
+  // C++ [basic.stc.dynamic.deallocation]p1:
+  //   A program is ill-formed if deallocation functions are declared in a
+  //   namespace scope other than global scope or declared static in global 
+  //   scope.
+  if (CheckOperatorNewDeleteDeclarationScope(SemaRef, FnDecl))
+    return true;
+
+  // C++ [basic.stc.dynamic.deallocation]p2:
+  //   Each deallocation function shall return void and its first parameter 
+  //   shall be void*.
+  if (CheckOperatorNewDeleteTypes(SemaRef, FnDecl, SemaRef.Context.VoidTy, 
+                                  SemaRef.Context.VoidPtrTy,
+                                 diag::err_operator_delete_dependent_param_type,
+                                 diag::err_operator_delete_param_type))
+    return true;
+
+  QualType FirstParamType = FnDecl->getParamDecl(0)->getType();
+  if (FirstParamType->isDependentType())
+    return SemaRef.Diag(FnDecl->getLocation(),
+                        diag::err_operator_delete_dependent_param_type)
+    << FnDecl->getDeclName() << SemaRef.Context.VoidPtrTy;
+
+  if (SemaRef.Context.getCanonicalType(FirstParamType) != 
+      SemaRef.Context.VoidPtrTy)
+    return SemaRef.Diag(FnDecl->getLocation(),
+                        diag::err_operator_delete_param_type)
+      << FnDecl->getDeclName() << SemaRef.Context.VoidPtrTy;
+  
+  return false;
+}
+
+/// CheckOverloadedOperatorDeclaration - Check whether the declaration
+/// of this overloaded operator is well-formed. If so, returns false;
+/// otherwise, emits appropriate diagnostics and returns true.
+bool Sema::CheckOverloadedOperatorDeclaration(FunctionDecl *FnDecl) {
+  assert(FnDecl && FnDecl->isOverloadedOperator() &&
+         "Expected an overloaded operator declaration");
+
+  OverloadedOperatorKind Op = FnDecl->getOverloadedOperator();
+
+  // C++ [over.oper]p5:
+  //   The allocation and deallocation functions, operator new,
+  //   operator new[], operator delete and operator delete[], are
+  //   described completely in 3.7.3. The attributes and restrictions
+  //   found in the rest of this subclause do not apply to them unless
+  //   explicitly stated in 3.7.3.
+  if (Op == OO_Delete || Op == OO_Array_Delete)
+    return CheckOperatorDeleteDeclaration(*this, FnDecl);
+  
+  if (Op == OO_New || Op == OO_Array_New)
+    return CheckOperatorNewDeclaration(*this, FnDecl);
+
+  // C++ [over.oper]p6:
+  //   An operator function shall either be a non-static member
+  //   function or be a non-member function and have at least one
+  //   parameter whose type is a class, a reference to a class, an
+  //   enumeration, or a reference to an enumeration.
+  if (CXXMethodDecl *MethodDecl = dyn_cast<CXXMethodDecl>(FnDecl)) {
+    if (MethodDecl->isStatic())
+      return Diag(FnDecl->getLocation(),
+                  diag::err_operator_overload_static) << FnDecl->getDeclName();
+  } else {
+    bool ClassOrEnumParam = false;
+    for (FunctionDecl::param_iterator Param = FnDecl->param_begin(),
+                                   ParamEnd = FnDecl->param_end();
+         Param != ParamEnd; ++Param) {
+      QualType ParamType = (*Param)->getType().getNonReferenceType();
+      if (ParamType->isDependentType() || ParamType->isRecordType() ||
+          ParamType->isEnumeralType()) {
+        ClassOrEnumParam = true;
+        break;
+      }
+    }
+
+    if (!ClassOrEnumParam)
+      return Diag(FnDecl->getLocation(),
+                  diag::err_operator_overload_needs_class_or_enum)
+        << FnDecl->getDeclName();
+  }
+
+  // C++ [over.oper]p8:
+  //   An operator function cannot have default arguments (8.3.6),
+  //   except where explicitly stated below.
+  //
+  // Only the function-call operator allows default arguments
+  // (C++ [over.call]p1).
+  if (Op != OO_Call) {
+    for (FunctionDecl::param_iterator Param = FnDecl->param_begin();
+         Param != FnDecl->param_end(); ++Param) {
+      if ((*Param)->hasDefaultArg())
+        return Diag((*Param)->getLocation(),
+                    diag::err_operator_overload_default_arg)
+          << FnDecl->getDeclName() << (*Param)->getDefaultArgRange();
+    }
+  }
+
+  static const bool OperatorUses[NUM_OVERLOADED_OPERATORS][3] = {
+    { false, false, false }
+#define OVERLOADED_OPERATOR(Name,Spelling,Token,Unary,Binary,MemberOnly) \
+    , { Unary, Binary, MemberOnly }
+#include "clang/Basic/OperatorKinds.def"
+  };
+
+  bool CanBeUnaryOperator = OperatorUses[Op][0];
+  bool CanBeBinaryOperator = OperatorUses[Op][1];
+  bool MustBeMemberOperator = OperatorUses[Op][2];
+
+  // C++ [over.oper]p8:
+  //   [...] Operator functions cannot have more or fewer parameters
+  //   than the number required for the corresponding operator, as
+  //   described in the rest of this subclause.
+  unsigned NumParams = FnDecl->getNumParams()
+                     + (isa<CXXMethodDecl>(FnDecl)? 1 : 0);
+  if (Op != OO_Call &&
+      ((NumParams == 1 && !CanBeUnaryOperator) ||
+       (NumParams == 2 && !CanBeBinaryOperator) ||
+       (NumParams < 1) || (NumParams > 2))) {
+    // We have the wrong number of parameters.
+    unsigned ErrorKind;
+    if (CanBeUnaryOperator && CanBeBinaryOperator) {
+      ErrorKind = 2;  // 2 -> unary or binary.
+    } else if (CanBeUnaryOperator) {
+      ErrorKind = 0;  // 0 -> unary
+    } else {
+      assert(CanBeBinaryOperator &&
+             "All non-call overloaded operators are unary or binary!");
+      ErrorKind = 1;  // 1 -> binary
+    }
+
+    return Diag(FnDecl->getLocation(), diag::err_operator_overload_must_be)
+      << FnDecl->getDeclName() << NumParams << ErrorKind;
+  }
+
+  // Overloaded operators other than operator() cannot be variadic.
+  if (Op != OO_Call &&
+      FnDecl->getType()->getAs<FunctionProtoType>()->isVariadic()) {
+    return Diag(FnDecl->getLocation(), diag::err_operator_overload_variadic)
+      << FnDecl->getDeclName();
+  }
+
+  // Some operators must be non-static member functions.
+  if (MustBeMemberOperator && !isa<CXXMethodDecl>(FnDecl)) {
+    return Diag(FnDecl->getLocation(),
+                diag::err_operator_overload_must_be_member)
+      << FnDecl->getDeclName();
+  }
+
+  // C++ [over.inc]p1:
+  //   The user-defined function called operator++ implements the
+  //   prefix and postfix ++ operator. If this function is a member
+  //   function with no parameters, or a non-member function with one
+  //   parameter of class or enumeration type, it defines the prefix
+  //   increment operator ++ for objects of that type. If the function
+  //   is a member function with one parameter (which shall be of type
+  //   int) or a non-member function with two parameters (the second
+  //   of which shall be of type int), it defines the postfix
+  //   increment operator ++ for objects of that type.
+  if ((Op == OO_PlusPlus || Op == OO_MinusMinus) && NumParams == 2) {
+    ParmVarDecl *LastParam = FnDecl->getParamDecl(FnDecl->getNumParams() - 1);
+    bool ParamIsInt = false;
+    if (const BuiltinType *BT = LastParam->getType()->getAs<BuiltinType>())
+      ParamIsInt = BT->getKind() == BuiltinType::Int;
+
+    if (!ParamIsInt)
+      return Diag(LastParam->getLocation(),
+                  diag::err_operator_overload_post_incdec_must_be_int)
+        << LastParam->getType() << (Op == OO_MinusMinus);
+  }
+
+  // Notify the class if it got an assignment operator.
+  if (Op == OO_Equal) {
+    // Would have returned earlier otherwise.
+    assert(isa<CXXMethodDecl>(FnDecl) &&
+      "Overloaded = not member, but not filtered.");
+    CXXMethodDecl *Method = cast<CXXMethodDecl>(FnDecl);
+    Method->getParent()->addedAssignmentOperator(Context, Method);
+  }
+
+  return false;
+}
+
+/// CheckLiteralOperatorDeclaration - Check whether the declaration
+/// of this literal operator function is well-formed. If so, returns
+/// false; otherwise, emits appropriate diagnostics and returns true.
+bool Sema::CheckLiteralOperatorDeclaration(FunctionDecl *FnDecl) {
+  DeclContext *DC = FnDecl->getDeclContext();
+  Decl::Kind Kind = DC->getDeclKind();
+  if (Kind != Decl::TranslationUnit && Kind != Decl::Namespace &&
+      Kind != Decl::LinkageSpec) {
+    Diag(FnDecl->getLocation(), diag::err_literal_operator_outside_namespace)
+      << FnDecl->getDeclName();
+    return true;
+  }
+
+  bool Valid = false;
+
+  // FIXME: Check for the one valid template signature
+  // template <char...> type operator "" name();
+
+  if (FunctionDecl::param_iterator Param = FnDecl->param_begin()) {
+    // Check the first parameter
+    QualType T = (*Param)->getType();
+
+    // unsigned long long int and long double are allowed, but only
+    // alone.
+    // We also allow any character type; their omission seems to be a bug
+    // in n3000
+    if (Context.hasSameType(T, Context.UnsignedLongLongTy) ||
+        Context.hasSameType(T, Context.LongDoubleTy) ||
+        Context.hasSameType(T, Context.CharTy) ||
+        Context.hasSameType(T, Context.WCharTy) ||
+        Context.hasSameType(T, Context.Char16Ty) ||
+        Context.hasSameType(T, Context.Char32Ty)) {
+      if (++Param == FnDecl->param_end())
+        Valid = true;
+      goto FinishedParams;
+    }
+
+    // Otherwise it must be a pointer to const; let's strip those.
+    const PointerType *PT = T->getAs<PointerType>();
+    if (!PT)
+      goto FinishedParams;
+    T = PT->getPointeeType();
+    if (!T.isConstQualified())
+      goto FinishedParams;
+    T = T.getUnqualifiedType();
+
+    // Move on to the second parameter;
+    ++Param;
+
+    // If there is no second parameter, the first must be a const char *
+    if (Param == FnDecl->param_end()) {
+      if (Context.hasSameType(T, Context.CharTy))
+        Valid = true;
+      goto FinishedParams;
+    }
+
+    // const char *, const wchar_t*, const char16_t*, and const char32_t*
+    // are allowed as the first parameter to a two-parameter function
+    if (!(Context.hasSameType(T, Context.CharTy) ||
+          Context.hasSameType(T, Context.WCharTy) ||
+          Context.hasSameType(T, Context.Char16Ty) ||
+          Context.hasSameType(T, Context.Char32Ty)))
+      goto FinishedParams;
+
+    // The second and final parameter must be an std::size_t
+    T = (*Param)->getType().getUnqualifiedType();
+    if (Context.hasSameType(T, Context.getSizeType()) &&
+        ++Param == FnDecl->param_end())
+      Valid = true;
+  }
+
+  // FIXME: This diagnostic is absolutely terrible.
+FinishedParams:
+  if (!Valid) {
+    Diag(FnDecl->getLocation(), diag::err_literal_operator_params)
+      << FnDecl->getDeclName();
+    return true;
+  }
+
+  return false;
+}
+
+/// ActOnStartLinkageSpecification - Parsed the beginning of a C++
+/// linkage specification, including the language and (if present)
+/// the '{'. ExternLoc is the location of the 'extern', LangLoc is
+/// the location of the language string literal, which is provided
+/// by Lang/StrSize. LBraceLoc, if valid, provides the location of
+/// the '{' brace. Otherwise, this linkage specification does not
+/// have any braces.
+Sema::DeclPtrTy Sema::ActOnStartLinkageSpecification(Scope *S,
+                                                     SourceLocation ExternLoc,
+                                                     SourceLocation LangLoc,
+                                                     const char *Lang,
+                                                     unsigned StrSize,
+                                                     SourceLocation LBraceLoc) {
+  LinkageSpecDecl::LanguageIDs Language;
+  if (strncmp(Lang, "\"C\"", StrSize) == 0)
+    Language = LinkageSpecDecl::lang_c;
+  else if (strncmp(Lang, "\"C++\"", StrSize) == 0)
+    Language = LinkageSpecDecl::lang_cxx;
+  else {
+    Diag(LangLoc, diag::err_bad_language);
+    return DeclPtrTy();
+  }
+
+  // FIXME: Add all the various semantics of linkage specifications
+
+  LinkageSpecDecl *D = LinkageSpecDecl::Create(Context, CurContext,
+                                               LangLoc, Language,
+                                               LBraceLoc.isValid());
+  CurContext->addDecl(D);
+  PushDeclContext(S, D);
+  return DeclPtrTy::make(D);
+}
+
+/// ActOnFinishLinkageSpecification - Completely the definition of
+/// the C++ linkage specification LinkageSpec. If RBraceLoc is
+/// valid, it's the position of the closing '}' brace in a linkage
+/// specification that uses braces.
+Sema::DeclPtrTy Sema::ActOnFinishLinkageSpecification(Scope *S,
+                                                      DeclPtrTy LinkageSpec,
+                                                      SourceLocation RBraceLoc) {
+  if (LinkageSpec)
+    PopDeclContext();
+  return LinkageSpec;
+}
+
+/// \brief Perform semantic analysis for the variable declaration that
+/// occurs within a C++ catch clause, returning the newly-created
+/// variable.
+VarDecl *Sema::BuildExceptionDeclaration(Scope *S, QualType ExDeclType,
+                                         TypeSourceInfo *TInfo,
+                                         IdentifierInfo *Name,
+                                         SourceLocation Loc,
+                                         SourceRange Range) {
+  bool Invalid = false;
+
+  // Arrays and functions decay.
+  if (ExDeclType->isArrayType())
+    ExDeclType = Context.getArrayDecayedType(ExDeclType);
+  else if (ExDeclType->isFunctionType())
+    ExDeclType = Context.getPointerType(ExDeclType);
+
+  // C++ 15.3p1: The exception-declaration shall not denote an incomplete type.
+  // The exception-declaration shall not denote a pointer or reference to an
+  // incomplete type, other than [cv] void*.
+  // N2844 forbids rvalue references.
+  if (!ExDeclType->isDependentType() && ExDeclType->isRValueReferenceType()) {
+    Diag(Loc, diag::err_catch_rvalue_ref) << Range;
+    Invalid = true;
+  }
+
+  QualType BaseType = ExDeclType;
+  int Mode = 0; // 0 for direct type, 1 for pointer, 2 for reference
+  unsigned DK = diag::err_catch_incomplete;
+  if (const PointerType *Ptr = BaseType->getAs<PointerType>()) {
+    BaseType = Ptr->getPointeeType();
+    Mode = 1;
+    DK = diag::err_catch_incomplete_ptr;
+  } else if (const ReferenceType *Ref = BaseType->getAs<ReferenceType>()) {
+    // For the purpose of error recovery, we treat rvalue refs like lvalue refs.
+    BaseType = Ref->getPointeeType();
+    Mode = 2;
+    DK = diag::err_catch_incomplete_ref;
+  }
+  if (!Invalid && (Mode == 0 || !BaseType->isVoidType()) &&
+      !BaseType->isDependentType() && RequireCompleteType(Loc, BaseType, DK))
+    Invalid = true;
+
+  if (!Invalid && !ExDeclType->isDependentType() &&
+      RequireNonAbstractType(Loc, ExDeclType,
+                             diag::err_abstract_type_in_decl,
+                             AbstractVariableType))
+    Invalid = true;
+
+  // FIXME: Need to test for ability to copy-construct and destroy the
+  // exception variable.
+
+  // FIXME: Need to check for abstract classes.
+
+  VarDecl *ExDecl = VarDecl::Create(Context, CurContext, Loc,
+                                    Name, ExDeclType, TInfo, VarDecl::None);
+
+  if (Invalid)
+    ExDecl->setInvalidDecl();
+
+  return ExDecl;
+}
+
+/// ActOnExceptionDeclarator - Parsed the exception-declarator in a C++ catch
+/// handler.
+Sema::DeclPtrTy Sema::ActOnExceptionDeclarator(Scope *S, Declarator &D) {
+  TypeSourceInfo *TInfo = 0;
+  QualType ExDeclType = GetTypeForDeclarator(D, S, &TInfo);
+
+  bool Invalid = D.isInvalidType();
+  IdentifierInfo *II = D.getIdentifier();
+  if (NamedDecl *PrevDecl = LookupSingleName(S, II, LookupOrdinaryName)) {
+    // The scope should be freshly made just for us. There is just no way
+    // it contains any previous declaration.
+    assert(!S->isDeclScope(DeclPtrTy::make(PrevDecl)));
+    if (PrevDecl->isTemplateParameter()) {
+      // Maybe we will complain about the shadowed template parameter.
+      DiagnoseTemplateParameterShadow(D.getIdentifierLoc(), PrevDecl);
+    }
+  }
+
+  if (D.getCXXScopeSpec().isSet() && !Invalid) {
+    Diag(D.getIdentifierLoc(), diag::err_qualified_catch_declarator)
+      << D.getCXXScopeSpec().getRange();
+    Invalid = true;
+  }
+
+  VarDecl *ExDecl = BuildExceptionDeclaration(S, ExDeclType, TInfo,
+                                              D.getIdentifier(),
+                                              D.getIdentifierLoc(),
+                                            D.getDeclSpec().getSourceRange());
+
+  if (Invalid)
+    ExDecl->setInvalidDecl();
+
+  // Add the exception declaration into this scope.
+  if (II)
+    PushOnScopeChains(ExDecl, S);
+  else
+    CurContext->addDecl(ExDecl);
+
+  ProcessDeclAttributes(S, ExDecl, D);
+  return DeclPtrTy::make(ExDecl);
+}
+
+Sema::DeclPtrTy Sema::ActOnStaticAssertDeclaration(SourceLocation AssertLoc,
+                                                   ExprArg assertexpr,
+                                                   ExprArg assertmessageexpr) {
+  Expr *AssertExpr = (Expr *)assertexpr.get();
+  StringLiteral *AssertMessage =
+    cast<StringLiteral>((Expr *)assertmessageexpr.get());
+
+  if (!AssertExpr->isTypeDependent() && !AssertExpr->isValueDependent()) {
+    llvm::APSInt Value(32);
+    if (!AssertExpr->isIntegerConstantExpr(Value, Context)) {
+      Diag(AssertLoc, diag::err_static_assert_expression_is_not_constant) <<
+        AssertExpr->getSourceRange();
+      return DeclPtrTy();
+    }
+
+    if (Value == 0) {
+      Diag(AssertLoc, diag::err_static_assert_failed)
+        << AssertMessage->getString() << AssertExpr->getSourceRange();
+    }
+  }
+
+  assertexpr.release();
+  assertmessageexpr.release();
+  Decl *Decl = StaticAssertDecl::Create(Context, CurContext, AssertLoc,
+                                        AssertExpr, AssertMessage);
+
+  CurContext->addDecl(Decl);
+  return DeclPtrTy::make(Decl);
+}
+
+/// Handle a friend type declaration.  This works in tandem with
+/// ActOnTag.
+///
+/// Notes on friend class templates:
+///
+/// We generally treat friend class declarations as if they were
+/// declaring a class.  So, for example, the elaborated type specifier
+/// in a friend declaration is required to obey the restrictions of a
+/// class-head (i.e. no typedefs in the scope chain), template
+/// parameters are required to match up with simple template-ids, &c.
+/// However, unlike when declaring a template specialization, it's
+/// okay to refer to a template specialization without an empty
+/// template parameter declaration, e.g.
+///   friend class A<T>::B<unsigned>;
+/// We permit this as a special case; if there are any template
+/// parameters present at all, require proper matching, i.e.
+///   template <> template <class T> friend class A<int>::B;
+Sema::DeclPtrTy Sema::ActOnFriendTypeDecl(Scope *S, const DeclSpec &DS,
+                                          MultiTemplateParamsArg TempParams) {
+  SourceLocation Loc = DS.getSourceRange().getBegin();
+
+  assert(DS.isFriendSpecified());
+  assert(DS.getStorageClassSpec() == DeclSpec::SCS_unspecified);
+
+  // Try to convert the decl specifier to a type.  This works for
+  // friend templates because ActOnTag never produces a ClassTemplateDecl
+  // for a TUK_Friend.
+  Declarator TheDeclarator(DS, Declarator::MemberContext);
+  QualType T = GetTypeForDeclarator(TheDeclarator, S);
+  if (TheDeclarator.isInvalidType())
+    return DeclPtrTy();
+
+  // This is definitely an error in C++98.  It's probably meant to
+  // be forbidden in C++0x, too, but the specification is just
+  // poorly written.
+  //
+  // The problem is with declarations like the following:
+  //   template <T> friend A<T>::foo;
+  // where deciding whether a class C is a friend or not now hinges
+  // on whether there exists an instantiation of A that causes
+  // 'foo' to equal C.  There are restrictions on class-heads
+  // (which we declare (by fiat) elaborated friend declarations to
+  // be) that makes this tractable.
+  //
+  // FIXME: handle "template <> friend class A<T>;", which
+  // is possibly well-formed?  Who even knows?
+  if (TempParams.size() && !isa<ElaboratedType>(T)) {
+    Diag(Loc, diag::err_tagless_friend_type_template)
+      << DS.getSourceRange();
+    return DeclPtrTy();
+  }
+
+  // C++ [class.friend]p2:
+  //   An elaborated-type-specifier shall be used in a friend declaration
+  //   for a class.*
+  //   * The class-key of the elaborated-type-specifier is required.
+  // This is one of the rare places in Clang where it's legitimate to
+  // ask about the "spelling" of the type.
+  if (!getLangOptions().CPlusPlus0x && !isa<ElaboratedType>(T)) {
+    // If we evaluated the type to a record type, suggest putting
+    // a tag in front.
+    if (const RecordType *RT = T->getAs<RecordType>()) {
+      RecordDecl *RD = RT->getDecl();
+
+      std::string InsertionText = std::string(" ") + RD->getKindName();
+
+      Diag(DS.getTypeSpecTypeLoc(), diag::err_unelaborated_friend_type)
+        << (unsigned) RD->getTagKind()
+        << T
+        << SourceRange(DS.getFriendSpecLoc())
+        << CodeModificationHint::CreateInsertion(DS.getTypeSpecTypeLoc(),
+                                                 InsertionText);
+      return DeclPtrTy();
+    }else {
+      Diag(DS.getFriendSpecLoc(), diag::err_unexpected_friend)
+          << DS.getSourceRange();
+      return DeclPtrTy();
+    }
+  }
+
+  // Enum types cannot be friends.
+  if (T->getAs<EnumType>()) {
+    Diag(DS.getTypeSpecTypeLoc(), diag::err_enum_friend)
+      << SourceRange(DS.getFriendSpecLoc());
+    return DeclPtrTy();
+  }
+
+  // C++98 [class.friend]p1: A friend of a class is a function
+  //   or class that is not a member of the class . . .
+  // This is fixed in DR77, which just barely didn't make the C++03
+  // deadline.  It's also a very silly restriction that seriously
+  // affects inner classes and which nobody else seems to implement;
+  // thus we never diagnose it, not even in -pedantic.
+
+  Decl *D;
+  if (TempParams.size())
+    D = FriendTemplateDecl::Create(Context, CurContext, Loc,
+                                   TempParams.size(),
+                                 (TemplateParameterList**) TempParams.release(),
+                                   T.getTypePtr(),
+                                   DS.getFriendSpecLoc());
+  else
+    D = FriendDecl::Create(Context, CurContext, Loc, T.getTypePtr(),
+                           DS.getFriendSpecLoc());
+  D->setAccess(AS_public);
+  CurContext->addDecl(D);
+
+  return DeclPtrTy::make(D);
+}
+
+Sema::DeclPtrTy
+Sema::ActOnFriendFunctionDecl(Scope *S,
+                              Declarator &D,
+                              bool IsDefinition,
+                              MultiTemplateParamsArg TemplateParams) {
+  const DeclSpec &DS = D.getDeclSpec();
+
+  assert(DS.isFriendSpecified());
+  assert(DS.getStorageClassSpec() == DeclSpec::SCS_unspecified);
+
+  SourceLocation Loc = D.getIdentifierLoc();
+  TypeSourceInfo *TInfo = 0;
+  QualType T = GetTypeForDeclarator(D, S, &TInfo);
+
+  // C++ [class.friend]p1
+  //   A friend of a class is a function or class....
+  // Note that this sees through typedefs, which is intended.
+  // It *doesn't* see through dependent types, which is correct
+  // according to [temp.arg.type]p3:
+  //   If a declaration acquires a function type through a
+  //   type dependent on a template-parameter and this causes
+  //   a declaration that does not use the syntactic form of a
+  //   function declarator to have a function type, the program
+  //   is ill-formed.
+  if (!T->isFunctionType()) {
+    Diag(Loc, diag::err_unexpected_friend);
+
+    // It might be worthwhile to try to recover by creating an
+    // appropriate declaration.
+    return DeclPtrTy();
+  }
+
+  // C++ [namespace.memdef]p3
+  //  - If a friend declaration in a non-local class first declares a
+  //    class or function, the friend class or function is a member
+  //    of the innermost enclosing namespace.
+  //  - The name of the friend is not found by simple name lookup
+  //    until a matching declaration is provided in that namespace
+  //    scope (either before or after the class declaration granting
+  //    friendship).
+  //  - If a friend function is called, its name may be found by the
+  //    name lookup that considers functions from namespaces and
+  //    classes associated with the types of the function arguments.
+  //  - When looking for a prior declaration of a class or a function
+  //    declared as a friend, scopes outside the innermost enclosing
+  //    namespace scope are not considered.
+
+  CXXScopeSpec &ScopeQual = D.getCXXScopeSpec();
+  DeclarationName Name = GetNameForDeclarator(D);
+  assert(Name);
+
+  // The context we found the declaration in, or in which we should
+  // create the declaration.
+  DeclContext *DC;
+
+  // FIXME: handle local classes
+
+  // Recover from invalid scope qualifiers as if they just weren't there.
+  LookupResult Previous(*this, Name, D.getIdentifierLoc(), LookupOrdinaryName,
+                        ForRedeclaration);
+  if (!ScopeQual.isInvalid() && ScopeQual.isSet()) {
+    // FIXME: RequireCompleteDeclContext
+    DC = computeDeclContext(ScopeQual);
+
+    // FIXME: handle dependent contexts
+    if (!DC) return DeclPtrTy();
+
+    LookupQualifiedName(Previous, DC);
+
+    // If searching in that context implicitly found a declaration in
+    // a different context, treat it like it wasn't found at all.
+    // TODO: better diagnostics for this case.  Suggesting the right
+    // qualified scope would be nice...
+    // FIXME: getRepresentativeDecl() is not right here at all
+    if (Previous.empty() ||
+        !Previous.getRepresentativeDecl()->getDeclContext()->Equals(DC)) {
+      D.setInvalidType();
+      Diag(Loc, diag::err_qualified_friend_not_found) << Name << T;
+      return DeclPtrTy();
+    }
+
+    // C++ [class.friend]p1: A friend of a class is a function or
+    //   class that is not a member of the class . . .
+    if (DC->Equals(CurContext))
+      Diag(DS.getFriendSpecLoc(), diag::err_friend_is_member);
+
+  // Otherwise walk out to the nearest namespace scope looking for matches.
+  } else {
+    // TODO: handle local class contexts.
+
+    DC = CurContext;
+    while (true) {
+      // Skip class contexts.  If someone can cite chapter and verse
+      // for this behavior, that would be nice --- it's what GCC and
+      // EDG do, and it seems like a reasonable intent, but the spec
+      // really only says that checks for unqualified existing
+      // declarations should stop at the nearest enclosing namespace,
+      // not that they should only consider the nearest enclosing
+      // namespace.
+      while (DC->isRecord()) 
+        DC = DC->getParent();
+
+      LookupQualifiedName(Previous, DC);
+
+      // TODO: decide what we think about using declarations.
+      if (!Previous.empty())
+        break;
+      
+      if (DC->isFileContext()) break;
+      DC = DC->getParent();
+    }
+
+    // C++ [class.friend]p1: A friend of a class is a function or
+    //   class that is not a member of the class . . .
+    // C++0x changes this for both friend types and functions.
+    // Most C++ 98 compilers do seem to give an error here, so
+    // we do, too.
+    if (!Previous.empty() && DC->Equals(CurContext)
+        && !getLangOptions().CPlusPlus0x)
+      Diag(DS.getFriendSpecLoc(), diag::err_friend_is_member);
+  }
+
+  if (DC->isFileContext()) {
+    // This implies that it has to be an operator or function.
+    if (D.getName().getKind() == UnqualifiedId::IK_ConstructorName ||
+        D.getName().getKind() == UnqualifiedId::IK_DestructorName ||
+        D.getName().getKind() == UnqualifiedId::IK_ConversionFunctionId) {
+      Diag(Loc, diag::err_introducing_special_friend) <<
+        (D.getName().getKind() == UnqualifiedId::IK_ConstructorName ? 0 :
+         D.getName().getKind() == UnqualifiedId::IK_DestructorName ? 1 : 2);
+      return DeclPtrTy();
+    }
+  }
+
+  bool Redeclaration = false;
+  NamedDecl *ND = ActOnFunctionDeclarator(S, D, DC, T, TInfo, Previous,
+                                          move(TemplateParams),
+                                          IsDefinition,
+                                          Redeclaration);
+  if (!ND) return DeclPtrTy();
+
+  assert(ND->getDeclContext() == DC);
+  assert(ND->getLexicalDeclContext() == CurContext);
+
+  // Add the function declaration to the appropriate lookup tables,
+  // adjusting the redeclarations list as necessary.  We don't
+  // want to do this yet if the friending class is dependent.
+  //
+  // Also update the scope-based lookup if the target context's
+  // lookup context is in lexical scope.
+  if (!CurContext->isDependentContext()) {
+    DC = DC->getLookupContext();
+    DC->makeDeclVisibleInContext(ND, /* Recoverable=*/ false);
+    if (Scope *EnclosingScope = getScopeForDeclContext(S, DC))
+      PushOnScopeChains(ND, EnclosingScope, /*AddToContext=*/ false);
+  }
+
+  FriendDecl *FrD = FriendDecl::Create(Context, CurContext,
+                                       D.getIdentifierLoc(), ND,
+                                       DS.getFriendSpecLoc());
+  FrD->setAccess(AS_public);
+  CurContext->addDecl(FrD);
+
+  if (D.getName().getKind() == UnqualifiedId::IK_TemplateId)
+    FrD->setSpecialization(true);
+
+  return DeclPtrTy::make(ND);
+}
+
+void Sema::SetDeclDeleted(DeclPtrTy dcl, SourceLocation DelLoc) {
+  AdjustDeclIfTemplate(dcl);
+
+  Decl *Dcl = dcl.getAs<Decl>();
+  FunctionDecl *Fn = dyn_cast<FunctionDecl>(Dcl);
+  if (!Fn) {
+    Diag(DelLoc, diag::err_deleted_non_function);
+    return;
+  }
+  if (const FunctionDecl *Prev = Fn->getPreviousDeclaration()) {
+    Diag(DelLoc, diag::err_deleted_decl_not_first);
+    Diag(Prev->getLocation(), diag::note_previous_declaration);
+    // If the declaration wasn't the first, we delete the function anyway for
+    // recovery.
+  }
+  Fn->setDeleted();
+}
+
+static void SearchForReturnInStmt(Sema &Self, Stmt *S) {
+  for (Stmt::child_iterator CI = S->child_begin(), E = S->child_end(); CI != E;
+       ++CI) {
+    Stmt *SubStmt = *CI;
+    if (!SubStmt)
+      continue;
+    if (isa<ReturnStmt>(SubStmt))
+      Self.Diag(SubStmt->getSourceRange().getBegin(),
+           diag::err_return_in_constructor_handler);
+    if (!isa<Expr>(SubStmt))
+      SearchForReturnInStmt(Self, SubStmt);
+  }
+}
+
+void Sema::DiagnoseReturnInConstructorExceptionHandler(CXXTryStmt *TryBlock) {
+  for (unsigned I = 0, E = TryBlock->getNumHandlers(); I != E; ++I) {
+    CXXCatchStmt *Handler = TryBlock->getHandler(I);
+    SearchForReturnInStmt(*this, Handler);
+  }
+}
+
+bool Sema::CheckOverridingFunctionReturnType(const CXXMethodDecl *New,
+                                             const CXXMethodDecl *Old) {
+  QualType NewTy = New->getType()->getAs<FunctionType>()->getResultType();
+  QualType OldTy = Old->getType()->getAs<FunctionType>()->getResultType();
+
+  if (Context.hasSameType(NewTy, OldTy))
+    return false;
+
+  // Check if the return types are covariant
+  QualType NewClassTy, OldClassTy;
+
+  /// Both types must be pointers or references to classes.
+  if (const PointerType *NewPT = NewTy->getAs<PointerType>()) {
+    if (const PointerType *OldPT = OldTy->getAs<PointerType>()) {
+      NewClassTy = NewPT->getPointeeType();
+      OldClassTy = OldPT->getPointeeType();
+    }
+  } else if (const ReferenceType *NewRT = NewTy->getAs<ReferenceType>()) {
+    if (const ReferenceType *OldRT = OldTy->getAs<ReferenceType>()) {
+      if (NewRT->getTypeClass() == OldRT->getTypeClass()) {
+        NewClassTy = NewRT->getPointeeType();
+        OldClassTy = OldRT->getPointeeType();
+      }
+    }
+  }
+
+  // The return types aren't either both pointers or references to a class type.
+  if (NewClassTy.isNull()) {
+    Diag(New->getLocation(),
+         diag::err_different_return_type_for_overriding_virtual_function)
+      << New->getDeclName() << NewTy << OldTy;
+    Diag(Old->getLocation(), diag::note_overridden_virtual_function);
+
+    return true;
+  }
+
+  // C++ [class.virtual]p6:
+  //   If the return type of D::f differs from the return type of B::f, the 
+  //   class type in the return type of D::f shall be complete at the point of
+  //   declaration of D::f or shall be the class type D.
+  if (const RecordType *RT = NewClassTy->getAs<RecordType>()) {
+    if (!RT->isBeingDefined() &&
+        RequireCompleteType(New->getLocation(), NewClassTy, 
+                            PDiag(diag::err_covariant_return_incomplete)
+                              << New->getDeclName()))
+    return true;
+  }
+
+  if (!Context.hasSameUnqualifiedType(NewClassTy, OldClassTy)) {
+    // Check if the new class derives from the old class.
+    if (!IsDerivedFrom(NewClassTy, OldClassTy)) {
+      Diag(New->getLocation(),
+           diag::err_covariant_return_not_derived)
+      << New->getDeclName() << NewTy << OldTy;
+      Diag(Old->getLocation(), diag::note_overridden_virtual_function);
+      return true;
+    }
+
+    // Check if we the conversion from derived to base is valid.
+    if (CheckDerivedToBaseConversion(NewClassTy, OldClassTy, ADK_covariance,
+                      diag::err_covariant_return_ambiguous_derived_to_base_conv,
+                      // FIXME: Should this point to the return type?
+                      New->getLocation(), SourceRange(), New->getDeclName())) {
+      Diag(Old->getLocation(), diag::note_overridden_virtual_function);
+      return true;
+    }
+  }
+
+  // The qualifiers of the return types must be the same.
+  if (NewTy.getLocalCVRQualifiers() != OldTy.getLocalCVRQualifiers()) {
+    Diag(New->getLocation(),
+         diag::err_covariant_return_type_different_qualifications)
+    << New->getDeclName() << NewTy << OldTy;
+    Diag(Old->getLocation(), diag::note_overridden_virtual_function);
+    return true;
+  };
+
+
+  // The new class type must have the same or less qualifiers as the old type.
+  if (NewClassTy.isMoreQualifiedThan(OldClassTy)) {
+    Diag(New->getLocation(),
+         diag::err_covariant_return_type_class_type_more_qualified)
+    << New->getDeclName() << NewTy << OldTy;
+    Diag(Old->getLocation(), diag::note_overridden_virtual_function);
+    return true;
+  };
+
+  return false;
+}
+
+bool Sema::CheckOverridingFunctionAttributes(const CXXMethodDecl *New,
+                                             const CXXMethodDecl *Old)
+{
+  if (Old->hasAttr<FinalAttr>()) {
+    Diag(New->getLocation(), diag::err_final_function_overridden)
+      << New->getDeclName();
+    Diag(Old->getLocation(), diag::note_overridden_virtual_function);
+    return true;
+  }
+
+  return false;
+}
+
+/// \brief Mark the given method pure.
+///
+/// \param Method the method to be marked pure.
+///
+/// \param InitRange the source range that covers the "0" initializer.
+bool Sema::CheckPureMethod(CXXMethodDecl *Method, SourceRange InitRange) {
+  if (Method->isVirtual() || Method->getParent()->isDependentContext()) {
+    Method->setPure();
+    
+    // A class is abstract if at least one function is pure virtual.
+    Method->getParent()->setAbstract(true);
+    return false;
+  } 
+
+  if (!Method->isInvalidDecl())
+    Diag(Method->getLocation(), diag::err_non_virtual_pure)
+      << Method->getDeclName() << InitRange;
+  return true;
+}
+
+/// ActOnCXXEnterDeclInitializer - Invoked when we are about to parse
+/// an initializer for the out-of-line declaration 'Dcl'.  The scope
+/// is a fresh scope pushed for just this purpose.
+///
+/// After this method is called, according to [C++ 3.4.1p13], if 'Dcl' is a
+/// static data member of class X, names should be looked up in the scope of
+/// class X.
+void Sema::ActOnCXXEnterDeclInitializer(Scope *S, DeclPtrTy Dcl) {
+  // If there is no declaration, there was an error parsing it.
+  Decl *D = Dcl.getAs<Decl>();
+  if (D == 0) return;
+
+  // We should only get called for declarations with scope specifiers, like:
+  //   int foo::bar;
+  assert(D->isOutOfLine());
+  EnterDeclaratorContext(S, D->getDeclContext());
+}
+
+/// ActOnCXXExitDeclInitializer - Invoked after we are finished parsing an
+/// initializer for the out-of-line declaration 'Dcl'.
+void Sema::ActOnCXXExitDeclInitializer(Scope *S, DeclPtrTy Dcl) {
+  // If there is no declaration, there was an error parsing it.
+  Decl *D = Dcl.getAs<Decl>();
+  if (D == 0) return;
+
+  assert(D->isOutOfLine());
+  ExitDeclaratorContext(S);
+}
+
+/// ActOnCXXConditionDeclarationExpr - Parsed a condition declaration of a
+/// C++ if/switch/while/for statement.
+/// e.g: "if (int x = f()) {...}"
+Action::DeclResult
+Sema::ActOnCXXConditionDeclaration(Scope *S, Declarator &D) {
+  // C++ 6.4p2:
+  // The declarator shall not specify a function or an array.
+  // The type-specifier-seq shall not contain typedef and shall not declare a
+  // new class or enumeration.
+  assert(D.getDeclSpec().getStorageClassSpec() != DeclSpec::SCS_typedef &&
+         "Parser allowed 'typedef' as storage class of condition decl.");
+  
+  TypeSourceInfo *TInfo = 0;
+  TagDecl *OwnedTag = 0;
+  QualType Ty = GetTypeForDeclarator(D, S, &TInfo, &OwnedTag);
+  
+  if (Ty->isFunctionType()) { // The declarator shall not specify a function...
+                              // We exit without creating a CXXConditionDeclExpr because a FunctionDecl
+                              // would be created and CXXConditionDeclExpr wants a VarDecl.
+    Diag(D.getIdentifierLoc(), diag::err_invalid_use_of_function_type)
+      << D.getSourceRange();
+    return DeclResult();
+  } else if (OwnedTag && OwnedTag->isDefinition()) {
+    // The type-specifier-seq shall not declare a new class or enumeration.
+    Diag(OwnedTag->getLocation(), diag::err_type_defined_in_condition);
+  }
+  
+  DeclPtrTy Dcl = ActOnDeclarator(S, D);
+  if (!Dcl)
+    return DeclResult();
+
+  VarDecl *VD = cast<VarDecl>(Dcl.getAs<Decl>());
+  VD->setDeclaredInCondition(true);
+  return Dcl;
+}
+
+void Sema::MaybeMarkVirtualMembersReferenced(SourceLocation Loc,
+                                             CXXMethodDecl *MD) {
+  // Ignore dependent types.
+  if (MD->isDependentContext())
+    return;
+  
+  CXXRecordDecl *RD = MD->getParent();
+  
+  // Ignore classes without a vtable.
+  if (!RD->isDynamicClass())
+    return;
+
+  // Ignore declarations that are not definitions.
+  if (!MD->isThisDeclarationADefinition())
+    return;
+  
+  if (isa<CXXConstructorDecl>(MD)) {
+    switch (MD->getParent()->getTemplateSpecializationKind()) {
+    case TSK_Undeclared:
+    case TSK_ExplicitSpecialization:
+      // Classes that aren't instantiations of templates don't need their
+      // virtual methods marked until we see the definition of the key 
+      // function.
+      return;
+        
+    case TSK_ImplicitInstantiation:
+    case TSK_ExplicitInstantiationDeclaration:
+    case TSK_ExplicitInstantiationDefinition:
+      // This is a constructor of a class template; mark all of the virtual
+      // members as referenced to ensure that they get instantiatied.
+      break;
+    }
+  } else if (!MD->isOutOfLine()) {
+    // Consider only out-of-line definitions of member functions. When we see
+    // an inline definition, it's too early to compute the key function.
+    return;
+  } else if (const CXXMethodDecl *KeyFunction = Context.getKeyFunction(RD)) {
+    // If this is not the key function, we don't need to mark virtual members.
+    if (KeyFunction->getCanonicalDecl() != MD->getCanonicalDecl())
+      return;
+  } else {
+    // The class has no key function, so we've already noted that we need to
+    // mark the virtual members of this class.
+    return;
+  }
+  
+  // We will need to mark all of the virtual members as referenced to build the
+  // vtable.
+  ClassesWithUnmarkedVirtualMembers.push_back(std::make_pair(RD, Loc));
+}
+
+bool Sema::ProcessPendingClassesWithUnmarkedVirtualMembers() {
+  if (ClassesWithUnmarkedVirtualMembers.empty())
+    return false;
+  
+  while (!ClassesWithUnmarkedVirtualMembers.empty()) {
+    CXXRecordDecl *RD = ClassesWithUnmarkedVirtualMembers.back().first;
+    SourceLocation Loc = ClassesWithUnmarkedVirtualMembers.back().second;
+    ClassesWithUnmarkedVirtualMembers.pop_back();
+    MarkVirtualMembersReferenced(Loc, RD);
+  }
+  
+  return true;
+}
+
+void Sema::MarkVirtualMembersReferenced(SourceLocation Loc, CXXRecordDecl *RD) {
+  for (CXXRecordDecl::method_iterator i = RD->method_begin(), 
+       e = RD->method_end(); i != e; ++i) {
+    CXXMethodDecl *MD = *i;
+
+    // C++ [basic.def.odr]p2:
+    //   [...] A virtual member function is used if it is not pure. [...]
+    if (MD->isVirtual() && !MD->isPure())
+      MarkDeclarationReferenced(Loc, MD);
+  }
+}
+