Merge branch 'master' of ssh://bitbucket.org/czan/honours

1 files changed, 2112 insertions, 0 deletions

diff --git a/clang/lib/Sema/SemaCast.cpp b/clang/lib/Sema/SemaCast.cpp
new file mode 100644
index 0000000..54683e1
--- /dev/null
+++ b/clang/lib/Sema/SemaCast.cpp
@@ -0,0 +1,2112 @@
+//===--- SemaCast.cpp - Semantic Analysis for Casts -----------------------===//
+//
+//                     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 cast expressions, including
+//  1) C-style casts like '(int) x'
+//  2) C++ functional casts like 'int(x)'
+//  3) C++ named casts like 'static_cast<int>(x)'
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Sema/SemaInternal.h"
+#include "clang/Sema/Initialization.h"
+#include "clang/AST/ExprCXX.h"
+#include "clang/AST/ExprObjC.h"
+#include "clang/AST/ASTContext.h"
+#include "clang/AST/CXXInheritance.h"
+#include "clang/Basic/PartialDiagnostic.h"
+#include "llvm/ADT/SmallVector.h"
+#include <set>
+using namespace clang;
+
+
+
+enum TryCastResult {
+  TC_NotApplicable, ///< The cast method is not applicable.
+  TC_Success,       ///< The cast method is appropriate and successful.
+  TC_Failed         ///< The cast method is appropriate, but failed. A
+                    ///< diagnostic has been emitted.
+};
+
+enum CastType {
+  CT_Const,       ///< const_cast
+  CT_Static,      ///< static_cast
+  CT_Reinterpret, ///< reinterpret_cast
+  CT_Dynamic,     ///< dynamic_cast
+  CT_CStyle,      ///< (Type)expr
+  CT_Functional   ///< Type(expr)
+};
+
+namespace {
+  struct CastOperation {
+    CastOperation(Sema &S, QualType destType, ExprResult src)
+      : Self(S), SrcExpr(src), DestType(destType),
+        ResultType(destType.getNonLValueExprType(S.Context)),
+        ValueKind(Expr::getValueKindForType(destType)),
+        Kind(CK_Dependent), IsARCUnbridgedCast(false) {
+
+      if (const BuiltinType *placeholder =
+            src.get()->getType()->getAsPlaceholderType()) {
+        PlaceholderKind = placeholder->getKind();
+      } else {
+        PlaceholderKind = (BuiltinType::Kind) 0;
+      }
+    }
+
+    Sema &Self;
+    ExprResult SrcExpr;
+    QualType DestType;
+    QualType ResultType;
+    ExprValueKind ValueKind;
+    CastKind Kind;
+    BuiltinType::Kind PlaceholderKind;
+    CXXCastPath BasePath;
+    bool IsARCUnbridgedCast;
+
+    SourceRange OpRange;
+    SourceRange DestRange;
+
+    // Top-level semantics-checking routines.
+    void CheckConstCast();
+    void CheckReinterpretCast();
+    void CheckStaticCast();
+    void CheckDynamicCast();
+    void CheckCXXCStyleCast(bool FunctionalCast, bool ListInitialization);
+    void CheckCStyleCast();
+
+    /// Complete an apparently-successful cast operation that yields
+    /// the given expression.
+    ExprResult complete(CastExpr *castExpr) {
+      // If this is an unbridged cast, wrap the result in an implicit
+      // cast that yields the unbridged-cast placeholder type.
+      if (IsARCUnbridgedCast) {
+        castExpr = ImplicitCastExpr::Create(Self.Context,
+                                            Self.Context.ARCUnbridgedCastTy,
+                                            CK_Dependent, castExpr, 0,
+                                            castExpr->getValueKind());
+      }
+      return Self.Owned(castExpr);
+    }
+
+    // Internal convenience methods.
+
+    /// Try to handle the given placeholder expression kind.  Return
+    /// true if the source expression has the appropriate placeholder
+    /// kind.  A placeholder can only be claimed once.
+    bool claimPlaceholder(BuiltinType::Kind K) {
+      if (PlaceholderKind != K) return false;
+
+      PlaceholderKind = (BuiltinType::Kind) 0;
+      return true;
+    }
+
+    bool isPlaceholder() const {
+      return PlaceholderKind != 0;
+    }
+    bool isPlaceholder(BuiltinType::Kind K) const {
+      return PlaceholderKind == K;
+    }
+
+    void checkCastAlign() {
+      Self.CheckCastAlign(SrcExpr.get(), DestType, OpRange);
+    }
+
+    void checkObjCARCConversion(Sema::CheckedConversionKind CCK) {
+      assert(Self.getLangOpts().ObjCAutoRefCount);
+
+      Expr *src = SrcExpr.get();
+      if (Self.CheckObjCARCConversion(OpRange, DestType, src, CCK) ==
+            Sema::ACR_unbridged)
+        IsARCUnbridgedCast = true;
+      SrcExpr = src;
+    }
+
+    /// Check for and handle non-overload placeholder expressions.
+    void checkNonOverloadPlaceholders() {
+      if (!isPlaceholder() || isPlaceholder(BuiltinType::Overload))
+        return;
+
+      SrcExpr = Self.CheckPlaceholderExpr(SrcExpr.take());
+      if (SrcExpr.isInvalid())
+        return;
+      PlaceholderKind = (BuiltinType::Kind) 0;
+    }
+  };
+}
+
+static bool CastsAwayConstness(Sema &Self, QualType SrcType, QualType DestType,
+                               bool CheckCVR, bool CheckObjCLifetime);
+
+// The Try functions attempt a specific way of casting. If they succeed, they
+// return TC_Success. If their way of casting is not appropriate for the given
+// arguments, they return TC_NotApplicable and *may* set diag to a diagnostic
+// to emit if no other way succeeds. If their way of casting is appropriate but
+// fails, they return TC_Failed and *must* set diag; they can set it to 0 if
+// they emit a specialized diagnostic.
+// All diagnostics returned by these functions must expect the same three
+// arguments:
+// %0: Cast Type (a value from the CastType enumeration)
+// %1: Source Type
+// %2: Destination Type
+static TryCastResult TryLValueToRValueCast(Sema &Self, Expr *SrcExpr,
+                                           QualType DestType, bool CStyle,
+                                           CastKind &Kind,
+                                           CXXCastPath &BasePath,
+                                           unsigned &msg);
+static TryCastResult TryStaticReferenceDowncast(Sema &Self, Expr *SrcExpr,
+                                               QualType DestType, bool CStyle,
+                                               const SourceRange &OpRange,
+                                               unsigned &msg,
+                                               CastKind &Kind,
+                                               CXXCastPath &BasePath);
+static TryCastResult TryStaticPointerDowncast(Sema &Self, QualType SrcType,
+                                              QualType DestType, bool CStyle,
+                                              const SourceRange &OpRange,
+                                              unsigned &msg,
+                                              CastKind &Kind,
+                                              CXXCastPath &BasePath);
+static TryCastResult TryStaticDowncast(Sema &Self, CanQualType SrcType,
+                                       CanQualType DestType, bool CStyle,
+                                       const SourceRange &OpRange,
+                                       QualType OrigSrcType,
+                                       QualType OrigDestType, unsigned &msg,
+                                       CastKind &Kind,
+                                       CXXCastPath &BasePath);
+static TryCastResult TryStaticMemberPointerUpcast(Sema &Self, ExprResult &SrcExpr,
+                                               QualType SrcType,
+                                               QualType DestType,bool CStyle,
+                                               const SourceRange &OpRange,
+                                               unsigned &msg,
+                                               CastKind &Kind,
+                                               CXXCastPath &BasePath);
+
+static TryCastResult TryStaticImplicitCast(Sema &Self, ExprResult &SrcExpr,
+                                           QualType DestType, 
+                                           Sema::CheckedConversionKind CCK,
+                                           const SourceRange &OpRange,
+                                           unsigned &msg, CastKind &Kind,
+                                           bool ListInitialization);
+static TryCastResult TryStaticCast(Sema &Self, ExprResult &SrcExpr,
+                                   QualType DestType, 
+                                   Sema::CheckedConversionKind CCK,
+                                   const SourceRange &OpRange,
+                                   unsigned &msg, CastKind &Kind,
+                                   CXXCastPath &BasePath,
+                                   bool ListInitialization);
+static TryCastResult TryConstCast(Sema &Self, Expr *SrcExpr, QualType DestType,
+                                  bool CStyle, unsigned &msg);
+static TryCastResult TryReinterpretCast(Sema &Self, ExprResult &SrcExpr,
+                                        QualType DestType, bool CStyle,
+                                        const SourceRange &OpRange,
+                                        unsigned &msg,
+                                        CastKind &Kind);
+
+
+/// ActOnCXXNamedCast - Parse {dynamic,static,reinterpret,const}_cast's.
+ExprResult
+Sema::ActOnCXXNamedCast(SourceLocation OpLoc, tok::TokenKind Kind,
+                        SourceLocation LAngleBracketLoc, Declarator &D,
+                        SourceLocation RAngleBracketLoc,
+                        SourceLocation LParenLoc, Expr *E,
+                        SourceLocation RParenLoc) {
+
+  assert(!D.isInvalidType());
+
+  TypeSourceInfo *TInfo = GetTypeForDeclaratorCast(D, E->getType());
+  if (D.isInvalidType())
+    return ExprError();
+
+  if (getLangOpts().CPlusPlus) {
+    // Check that there are no default arguments (C++ only).
+    CheckExtraCXXDefaultArguments(D);
+  }
+
+  return BuildCXXNamedCast(OpLoc, Kind, TInfo, move(E),
+                           SourceRange(LAngleBracketLoc, RAngleBracketLoc),
+                           SourceRange(LParenLoc, RParenLoc));
+}
+
+ExprResult
+Sema::BuildCXXNamedCast(SourceLocation OpLoc, tok::TokenKind Kind,
+                        TypeSourceInfo *DestTInfo, Expr *E,
+                        SourceRange AngleBrackets, SourceRange Parens) {
+  ExprResult Ex = Owned(E);
+  QualType DestType = DestTInfo->getType();
+
+  // If the type is dependent, we won't do the semantic analysis now.
+  // FIXME: should we check this in a more fine-grained manner?
+  bool TypeDependent = DestType->isDependentType() || Ex.get()->isTypeDependent();
+
+  CastOperation Op(*this, DestType, E);
+  Op.OpRange = SourceRange(OpLoc, Parens.getEnd());
+  Op.DestRange = AngleBrackets;
+
+  switch (Kind) {
+  default: llvm_unreachable("Unknown C++ cast!");
+
+  case tok::kw_const_cast:
+    if (!TypeDependent) {
+      Op.CheckConstCast();
+      if (Op.SrcExpr.isInvalid())
+        return ExprError();
+    }
+    return Op.complete(CXXConstCastExpr::Create(Context, Op.ResultType,
+                                  Op.ValueKind, Op.SrcExpr.take(), DestTInfo,
+                                                OpLoc, Parens.getEnd()));
+
+  case tok::kw_dynamic_cast: {
+    if (!TypeDependent) {
+      Op.CheckDynamicCast();
+      if (Op.SrcExpr.isInvalid())
+        return ExprError();
+    }
+    return Op.complete(CXXDynamicCastExpr::Create(Context, Op.ResultType,
+                                    Op.ValueKind, Op.Kind, Op.SrcExpr.take(),
+                                                  &Op.BasePath, DestTInfo,
+                                                  OpLoc, Parens.getEnd()));
+  }
+  case tok::kw_reinterpret_cast: {
+    if (!TypeDependent) {
+      Op.CheckReinterpretCast();
+      if (Op.SrcExpr.isInvalid())
+        return ExprError();
+    }
+    return Op.complete(CXXReinterpretCastExpr::Create(Context, Op.ResultType,
+                                    Op.ValueKind, Op.Kind, Op.SrcExpr.take(),
+                                                      0, DestTInfo, OpLoc,
+                                                      Parens.getEnd()));
+  }
+  case tok::kw_static_cast: {
+    if (!TypeDependent) {
+      Op.CheckStaticCast();
+      if (Op.SrcExpr.isInvalid())
+        return ExprError();
+    }
+    
+    return Op.complete(CXXStaticCastExpr::Create(Context, Op.ResultType,
+                                   Op.ValueKind, Op.Kind, Op.SrcExpr.take(),
+                                                 &Op.BasePath, DestTInfo,
+                                                 OpLoc, Parens.getEnd()));
+  }
+  }
+}
+
+/// Try to diagnose a failed overloaded cast.  Returns true if
+/// diagnostics were emitted.
+static bool tryDiagnoseOverloadedCast(Sema &S, CastType CT,
+                                      SourceRange range, Expr *src,
+                                      QualType destType,
+                                      bool listInitialization) {
+  switch (CT) {
+  // These cast kinds don't consider user-defined conversions.
+  case CT_Const:
+  case CT_Reinterpret:
+  case CT_Dynamic:
+    return false;
+
+  // These do.
+  case CT_Static:
+  case CT_CStyle:
+  case CT_Functional:
+    break;
+  }
+
+  QualType srcType = src->getType();
+  if (!destType->isRecordType() && !srcType->isRecordType())
+    return false;
+
+  InitializedEntity entity = InitializedEntity::InitializeTemporary(destType);
+  InitializationKind initKind
+    = (CT == CT_CStyle)? InitializationKind::CreateCStyleCast(range.getBegin(),
+                                                      range, listInitialization)
+    : (CT == CT_Functional)? InitializationKind::CreateFunctionalCast(range,
+                                                             listInitialization)
+    : InitializationKind::CreateCast(/*type range?*/ range);
+  InitializationSequence sequence(S, entity, initKind, &src, 1);
+
+  assert(sequence.Failed() && "initialization succeeded on second try?");
+  switch (sequence.getFailureKind()) {
+  default: return false;
+
+  case InitializationSequence::FK_ConstructorOverloadFailed:
+  case InitializationSequence::FK_UserConversionOverloadFailed:
+    break;
+  }
+
+  OverloadCandidateSet &candidates = sequence.getFailedCandidateSet();
+
+  unsigned msg = 0;
+  OverloadCandidateDisplayKind howManyCandidates = OCD_AllCandidates;
+
+  switch (sequence.getFailedOverloadResult()) {
+  case OR_Success: llvm_unreachable("successful failed overload");
+  case OR_No_Viable_Function:
+    if (candidates.empty())
+      msg = diag::err_ovl_no_conversion_in_cast;
+    else
+      msg = diag::err_ovl_no_viable_conversion_in_cast;
+    howManyCandidates = OCD_AllCandidates;
+    break;
+
+  case OR_Ambiguous:
+    msg = diag::err_ovl_ambiguous_conversion_in_cast;
+    howManyCandidates = OCD_ViableCandidates;
+    break;
+
+  case OR_Deleted:
+    msg = diag::err_ovl_deleted_conversion_in_cast;
+    howManyCandidates = OCD_ViableCandidates;
+    break;
+  }
+
+  S.Diag(range.getBegin(), msg)
+    << CT << srcType << destType
+    << range << src->getSourceRange();
+
+  candidates.NoteCandidates(S, howManyCandidates, src);
+
+  return true;
+}
+
+/// Diagnose a failed cast.
+static void diagnoseBadCast(Sema &S, unsigned msg, CastType castType,
+                            SourceRange opRange, Expr *src, QualType destType,
+                            bool listInitialization) {
+  if (src->getType() == S.Context.BoundMemberTy) {
+    (void) S.CheckPlaceholderExpr(src); // will always fail
+    return;
+  }
+
+  if (msg == diag::err_bad_cxx_cast_generic &&
+      tryDiagnoseOverloadedCast(S, castType, opRange, src, destType,
+                                listInitialization))
+    return;
+
+  S.Diag(opRange.getBegin(), msg) << castType
+    << src->getType() << destType << opRange << src->getSourceRange();
+}
+
+/// UnwrapDissimilarPointerTypes - Like Sema::UnwrapSimilarPointerTypes,
+/// this removes one level of indirection from both types, provided that they're
+/// the same kind of pointer (plain or to-member). Unlike the Sema function,
+/// this one doesn't care if the two pointers-to-member don't point into the
+/// same class. This is because CastsAwayConstness doesn't care.
+static bool UnwrapDissimilarPointerTypes(QualType& T1, QualType& T2) {
+  const PointerType *T1PtrType = T1->getAs<PointerType>(),
+                    *T2PtrType = T2->getAs<PointerType>();
+  if (T1PtrType && T2PtrType) {
+    T1 = T1PtrType->getPointeeType();
+    T2 = T2PtrType->getPointeeType();
+    return true;
+  }
+  const ObjCObjectPointerType *T1ObjCPtrType = 
+                                            T1->getAs<ObjCObjectPointerType>(),
+                              *T2ObjCPtrType = 
+                                            T2->getAs<ObjCObjectPointerType>();
+  if (T1ObjCPtrType) {
+    if (T2ObjCPtrType) {
+      T1 = T1ObjCPtrType->getPointeeType();
+      T2 = T2ObjCPtrType->getPointeeType();
+      return true;
+    }
+    else if (T2PtrType) {
+      T1 = T1ObjCPtrType->getPointeeType();
+      T2 = T2PtrType->getPointeeType();
+      return true;
+    }
+  }
+  else if (T2ObjCPtrType) {
+    if (T1PtrType) {
+      T2 = T2ObjCPtrType->getPointeeType();
+      T1 = T1PtrType->getPointeeType();
+      return true;
+    }
+  }
+  
+  const MemberPointerType *T1MPType = T1->getAs<MemberPointerType>(),
+                          *T2MPType = T2->getAs<MemberPointerType>();
+  if (T1MPType && T2MPType) {
+    T1 = T1MPType->getPointeeType();
+    T2 = T2MPType->getPointeeType();
+    return true;
+  }
+  
+  const BlockPointerType *T1BPType = T1->getAs<BlockPointerType>(),
+                         *T2BPType = T2->getAs<BlockPointerType>();
+  if (T1BPType && T2BPType) {
+    T1 = T1BPType->getPointeeType();
+    T2 = T2BPType->getPointeeType();
+    return true;
+  }
+  
+  return false;
+}
+
+/// CastsAwayConstness - Check if the pointer conversion from SrcType to
+/// DestType casts away constness as defined in C++ 5.2.11p8ff. This is used by
+/// the cast checkers.  Both arguments must denote pointer (possibly to member)
+/// types.
+///
+/// \param CheckCVR Whether to check for const/volatile/restrict qualifiers.
+///
+/// \param CheckObjCLifetime Whether to check Objective-C lifetime qualifiers.
+static bool
+CastsAwayConstness(Sema &Self, QualType SrcType, QualType DestType,
+                   bool CheckCVR, bool CheckObjCLifetime) {
+  // If the only checking we care about is for Objective-C lifetime qualifiers,
+  // and we're not in ARC mode, there's nothing to check.
+  if (!CheckCVR && CheckObjCLifetime && 
+      !Self.Context.getLangOpts().ObjCAutoRefCount)
+    return false;
+    
+  // Casting away constness is defined in C++ 5.2.11p8 with reference to
+  // C++ 4.4. We piggyback on Sema::IsQualificationConversion for this, since
+  // the rules are non-trivial. So first we construct Tcv *...cv* as described
+  // in C++ 5.2.11p8.
+  assert((SrcType->isAnyPointerType() || SrcType->isMemberPointerType() ||
+          SrcType->isBlockPointerType()) &&
+         "Source type is not pointer or pointer to member.");
+  assert((DestType->isAnyPointerType() || DestType->isMemberPointerType() ||
+          DestType->isBlockPointerType()) &&
+         "Destination type is not pointer or pointer to member.");
+
+  QualType UnwrappedSrcType = Self.Context.getCanonicalType(SrcType), 
+           UnwrappedDestType = Self.Context.getCanonicalType(DestType);
+  SmallVector<Qualifiers, 8> cv1, cv2;
+
+  // Find the qualifiers. We only care about cvr-qualifiers for the 
+  // purpose of this check, because other qualifiers (address spaces, 
+  // Objective-C GC, etc.) are part of the type's identity.
+  while (UnwrapDissimilarPointerTypes(UnwrappedSrcType, UnwrappedDestType)) {
+    // Determine the relevant qualifiers at this level.
+    Qualifiers SrcQuals, DestQuals;
+    Self.Context.getUnqualifiedArrayType(UnwrappedSrcType, SrcQuals);
+    Self.Context.getUnqualifiedArrayType(UnwrappedDestType, DestQuals);
+    
+    Qualifiers RetainedSrcQuals, RetainedDestQuals;
+    if (CheckCVR) {
+      RetainedSrcQuals.setCVRQualifiers(SrcQuals.getCVRQualifiers());
+      RetainedDestQuals.setCVRQualifiers(DestQuals.getCVRQualifiers());
+    }
+    
+    if (CheckObjCLifetime &&
+        !DestQuals.compatiblyIncludesObjCLifetime(SrcQuals))
+      return true;
+    
+    cv1.push_back(RetainedSrcQuals);
+    cv2.push_back(RetainedDestQuals);
+  }
+  if (cv1.empty())
+    return false;
+
+  // Construct void pointers with those qualifiers (in reverse order of
+  // unwrapping, of course).
+  QualType SrcConstruct = Self.Context.VoidTy;
+  QualType DestConstruct = Self.Context.VoidTy;
+  ASTContext &Context = Self.Context;
+  for (SmallVector<Qualifiers, 8>::reverse_iterator i1 = cv1.rbegin(),
+                                                          i2 = cv2.rbegin();
+       i1 != cv1.rend(); ++i1, ++i2) {
+    SrcConstruct
+      = Context.getPointerType(Context.getQualifiedType(SrcConstruct, *i1));
+    DestConstruct
+      = Context.getPointerType(Context.getQualifiedType(DestConstruct, *i2));
+  }
+
+  // Test if they're compatible.
+  bool ObjCLifetimeConversion;
+  return SrcConstruct != DestConstruct &&
+    !Self.IsQualificationConversion(SrcConstruct, DestConstruct, false,
+                                    ObjCLifetimeConversion);
+}
+
+/// CheckDynamicCast - Check that a dynamic_cast\<DestType\>(SrcExpr) is valid.
+/// Refer to C++ 5.2.7 for details. Dynamic casts are used mostly for runtime-
+/// checked downcasts in class hierarchies.
+void CastOperation::CheckDynamicCast() {
+  if (ValueKind == VK_RValue)
+    SrcExpr = Self.DefaultFunctionArrayLvalueConversion(SrcExpr.take());
+  else if (isPlaceholder())
+    SrcExpr = Self.CheckPlaceholderExpr(SrcExpr.take());
+  if (SrcExpr.isInvalid()) // if conversion failed, don't report another error
+    return;
+
+  QualType OrigSrcType = SrcExpr.get()->getType();
+  QualType DestType = Self.Context.getCanonicalType(this->DestType);
+
+  // C++ 5.2.7p1: T shall be a pointer or reference to a complete class type,
+  //   or "pointer to cv void".
+
+  QualType DestPointee;
+  const PointerType *DestPointer = DestType->getAs<PointerType>();
+  const ReferenceType *DestReference = 0;
+  if (DestPointer) {
+    DestPointee = DestPointer->getPointeeType();
+  } else if ((DestReference = DestType->getAs<ReferenceType>())) {
+    DestPointee = DestReference->getPointeeType();
+  } else {
+    Self.Diag(OpRange.getBegin(), diag::err_bad_dynamic_cast_not_ref_or_ptr)
+      << this->DestType << DestRange;
+    return;
+  }
+
+  const RecordType *DestRecord = DestPointee->getAs<RecordType>();
+  if (DestPointee->isVoidType()) {
+    assert(DestPointer && "Reference to void is not possible");
+  } else if (DestRecord) {
+    if (Self.RequireCompleteType(OpRange.getBegin(), DestPointee,
+                               Self.PDiag(diag::err_bad_dynamic_cast_incomplete)
+                                   << DestRange))
+      return;
+  } else {
+    Self.Diag(OpRange.getBegin(), diag::err_bad_dynamic_cast_not_class)
+      << DestPointee.getUnqualifiedType() << DestRange;
+    return;
+  }
+
+  // C++0x 5.2.7p2: If T is a pointer type, v shall be an rvalue of a pointer to
+  //   complete class type, [...]. If T is an lvalue reference type, v shall be
+  //   an lvalue of a complete class type, [...]. If T is an rvalue reference 
+  //   type, v shall be an expression having a complete class type, [...]
+  QualType SrcType = Self.Context.getCanonicalType(OrigSrcType);
+  QualType SrcPointee;
+  if (DestPointer) {
+    if (const PointerType *SrcPointer = SrcType->getAs<PointerType>()) {
+      SrcPointee = SrcPointer->getPointeeType();
+    } else {
+      Self.Diag(OpRange.getBegin(), diag::err_bad_dynamic_cast_not_ptr)
+        << OrigSrcType << SrcExpr.get()->getSourceRange();
+      return;
+    }
+  } else if (DestReference->isLValueReferenceType()) {
+    if (!SrcExpr.get()->isLValue()) {
+      Self.Diag(OpRange.getBegin(), diag::err_bad_cxx_cast_rvalue)
+        << CT_Dynamic << OrigSrcType << this->DestType << OpRange;
+    }
+    SrcPointee = SrcType;
+  } else {
+    SrcPointee = SrcType;
+  }
+
+  const RecordType *SrcRecord = SrcPointee->getAs<RecordType>();
+  if (SrcRecord) {
+    if (Self.RequireCompleteType(OpRange.getBegin(), SrcPointee,
+                             Self.PDiag(diag::err_bad_dynamic_cast_incomplete)
+                                   << SrcExpr.get()->getSourceRange()))
+      return;
+  } else {
+    Self.Diag(OpRange.getBegin(), diag::err_bad_dynamic_cast_not_class)
+      << SrcPointee.getUnqualifiedType() << SrcExpr.get()->getSourceRange();
+    return;
+  }
+
+  assert((DestPointer || DestReference) &&
+    "Bad destination non-ptr/ref slipped through.");
+  assert((DestRecord || DestPointee->isVoidType()) &&
+    "Bad destination pointee slipped through.");
+  assert(SrcRecord && "Bad source pointee slipped through.");
+
+  // C++ 5.2.7p1: The dynamic_cast operator shall not cast away constness.
+  if (!DestPointee.isAtLeastAsQualifiedAs(SrcPointee)) {
+    Self.Diag(OpRange.getBegin(), diag::err_bad_cxx_cast_qualifiers_away)
+      << CT_Dynamic << OrigSrcType << this->DestType << OpRange;
+    return;
+  }
+
+  // C++ 5.2.7p3: If the type of v is the same as the required result type,
+  //   [except for cv].
+  if (DestRecord == SrcRecord) {
+    Kind = CK_NoOp;
+    return;
+  }
+
+  // C++ 5.2.7p5
+  // Upcasts are resolved statically.
+  if (DestRecord && Self.IsDerivedFrom(SrcPointee, DestPointee)) {
+    if (Self.CheckDerivedToBaseConversion(SrcPointee, DestPointee,
+                                           OpRange.getBegin(), OpRange, 
+                                           &BasePath))
+        return;
+        
+    Kind = CK_DerivedToBase;
+
+    // If we are casting to or through a virtual base class, we need a
+    // vtable.
+    if (Self.BasePathInvolvesVirtualBase(BasePath))
+      Self.MarkVTableUsed(OpRange.getBegin(), 
+                          cast<CXXRecordDecl>(SrcRecord->getDecl()));
+    return;
+  }
+
+  // C++ 5.2.7p6: Otherwise, v shall be [polymorphic].
+  const RecordDecl *SrcDecl = SrcRecord->getDecl()->getDefinition();
+  assert(SrcDecl && "Definition missing");
+  if (!cast<CXXRecordDecl>(SrcDecl)->isPolymorphic()) {
+    Self.Diag(OpRange.getBegin(), diag::err_bad_dynamic_cast_not_polymorphic)
+      << SrcPointee.getUnqualifiedType() << SrcExpr.get()->getSourceRange();
+  }
+  Self.MarkVTableUsed(OpRange.getBegin(), 
+                      cast<CXXRecordDecl>(SrcRecord->getDecl()));
+
+  // Done. Everything else is run-time checks.
+  Kind = CK_Dynamic;
+}
+
+/// CheckConstCast - Check that a const_cast\<DestType\>(SrcExpr) is valid.
+/// Refer to C++ 5.2.11 for details. const_cast is typically used in code
+/// like this:
+/// const char *str = "literal";
+/// legacy_function(const_cast\<char*\>(str));
+void CastOperation::CheckConstCast() {
+  if (ValueKind == VK_RValue)
+    SrcExpr = Self.DefaultFunctionArrayLvalueConversion(SrcExpr.take());
+  else if (isPlaceholder())
+    SrcExpr = Self.CheckPlaceholderExpr(SrcExpr.take());
+  if (SrcExpr.isInvalid()) // if conversion failed, don't report another error
+    return;
+
+  unsigned msg = diag::err_bad_cxx_cast_generic;
+  if (TryConstCast(Self, SrcExpr.get(), DestType, /*CStyle*/false, msg) != TC_Success
+      && msg != 0)
+    Self.Diag(OpRange.getBegin(), msg) << CT_Const
+      << SrcExpr.get()->getType() << DestType << OpRange;
+}
+
+/// CheckReinterpretCast - Check that a reinterpret_cast\<DestType\>(SrcExpr) is
+/// valid.
+/// Refer to C++ 5.2.10 for details. reinterpret_cast is typically used in code
+/// like this:
+/// char *bytes = reinterpret_cast\<char*\>(int_ptr);
+void CastOperation::CheckReinterpretCast() {
+  if (ValueKind == VK_RValue && !isPlaceholder(BuiltinType::Overload))
+    SrcExpr = Self.DefaultFunctionArrayLvalueConversion(SrcExpr.take());
+  else
+    checkNonOverloadPlaceholders();
+  if (SrcExpr.isInvalid()) // if conversion failed, don't report another error
+    return;
+
+  unsigned msg = diag::err_bad_cxx_cast_generic;
+  TryCastResult tcr = 
+    TryReinterpretCast(Self, SrcExpr, DestType, 
+                       /*CStyle*/false, OpRange, msg, Kind);
+  if (tcr != TC_Success && msg != 0)
+  {
+    if (SrcExpr.isInvalid()) // if conversion failed, don't report another error
+      return;
+    if (SrcExpr.get()->getType() == Self.Context.OverloadTy) {
+      //FIXME: &f<int>; is overloaded and resolvable 
+      Self.Diag(OpRange.getBegin(), diag::err_bad_reinterpret_cast_overload) 
+        << OverloadExpr::find(SrcExpr.get()).Expression->getName()
+        << DestType << OpRange;
+      Self.NoteAllOverloadCandidates(SrcExpr.get());
+
+    } else {
+      diagnoseBadCast(Self, msg, CT_Reinterpret, OpRange, SrcExpr.get(),
+                      DestType, /*listInitialization=*/false);
+    }
+  } else if (tcr == TC_Success && Self.getLangOpts().ObjCAutoRefCount) {
+    checkObjCARCConversion(Sema::CCK_OtherCast);
+  }
+}
+
+
+/// CheckStaticCast - Check that a static_cast\<DestType\>(SrcExpr) is valid.
+/// Refer to C++ 5.2.9 for details. Static casts are mostly used for making
+/// implicit conversions explicit and getting rid of data loss warnings.
+void CastOperation::CheckStaticCast() {
+  if (isPlaceholder()) {
+    checkNonOverloadPlaceholders();
+    if (SrcExpr.isInvalid())
+      return;
+  }
+
+  // This test is outside everything else because it's the only case where
+  // a non-lvalue-reference target type does not lead to decay.
+  // C++ 5.2.9p4: Any expression can be explicitly converted to type "cv void".
+  if (DestType->isVoidType()) {
+    Kind = CK_ToVoid;
+
+    if (claimPlaceholder(BuiltinType::Overload)) {
+      Self.ResolveAndFixSingleFunctionTemplateSpecialization(SrcExpr, 
+                false, // Decay Function to ptr 
+                true, // Complain
+                OpRange, DestType, diag::err_bad_static_cast_overload);
+      if (SrcExpr.isInvalid())
+        return;
+    }
+
+    SrcExpr = Self.IgnoredValueConversions(SrcExpr.take());
+    return;
+  }
+
+  if (ValueKind == VK_RValue && !DestType->isRecordType() &&
+      !isPlaceholder(BuiltinType::Overload)) {
+    SrcExpr = Self.DefaultFunctionArrayLvalueConversion(SrcExpr.take());
+    if (SrcExpr.isInvalid()) // if conversion failed, don't report another error
+      return;
+  }
+
+  unsigned msg = diag::err_bad_cxx_cast_generic;
+  TryCastResult tcr
+    = TryStaticCast(Self, SrcExpr, DestType, Sema::CCK_OtherCast, OpRange, msg,
+                    Kind, BasePath, /*ListInitialization=*/false);
+  if (tcr != TC_Success && msg != 0) {
+    if (SrcExpr.isInvalid())
+      return;
+    if (SrcExpr.get()->getType() == Self.Context.OverloadTy) {
+      OverloadExpr* oe = OverloadExpr::find(SrcExpr.get()).Expression;
+      Self.Diag(OpRange.getBegin(), diag::err_bad_static_cast_overload)
+        << oe->getName() << DestType << OpRange 
+        << oe->getQualifierLoc().getSourceRange();
+      Self.NoteAllOverloadCandidates(SrcExpr.get());
+    } else {
+      diagnoseBadCast(Self, msg, CT_Static, OpRange, SrcExpr.get(), DestType,
+                      /*listInitialization=*/false);
+    }
+  } else if (tcr == TC_Success) {
+    if (Kind == CK_BitCast)
+      checkCastAlign();
+    if (Self.getLangOpts().ObjCAutoRefCount)
+      checkObjCARCConversion(Sema::CCK_OtherCast);
+  } else if (Kind == CK_BitCast) {
+    checkCastAlign();
+  }
+}
+
+/// TryStaticCast - Check if a static cast can be performed, and do so if
+/// possible. If @p CStyle, ignore access restrictions on hierarchy casting
+/// and casting away constness.
+static TryCastResult TryStaticCast(Sema &Self, ExprResult &SrcExpr,
+                                   QualType DestType, 
+                                   Sema::CheckedConversionKind CCK,
+                                   const SourceRange &OpRange, unsigned &msg,
+                                   CastKind &Kind, CXXCastPath &BasePath,
+                                   bool ListInitialization) {
+  // Determine whether we have the semantics of a C-style cast.
+  bool CStyle 
+    = (CCK == Sema::CCK_CStyleCast || CCK == Sema::CCK_FunctionalCast);
+  
+  // The order the tests is not entirely arbitrary. There is one conversion
+  // that can be handled in two different ways. Given:
+  // struct A {};
+  // struct B : public A {
+  //   B(); B(const A&);
+  // };
+  // const A &a = B();
+  // the cast static_cast<const B&>(a) could be seen as either a static
+  // reference downcast, or an explicit invocation of the user-defined
+  // conversion using B's conversion constructor.
+  // DR 427 specifies that the downcast is to be applied here.
+
+  // C++ 5.2.9p4: Any expression can be explicitly converted to type "cv void".
+  // Done outside this function.
+
+  TryCastResult tcr;
+
+  // C++ 5.2.9p5, reference downcast.
+  // See the function for details.
+  // DR 427 specifies that this is to be applied before paragraph 2.
+  tcr = TryStaticReferenceDowncast(Self, SrcExpr.get(), DestType, CStyle,
+                                   OpRange, msg, Kind, BasePath);
+  if (tcr != TC_NotApplicable)
+    return tcr;
+
+  // C++0x [expr.static.cast]p3: 
+  //   A glvalue of type "cv1 T1" can be cast to type "rvalue reference to cv2
+  //   T2" if "cv2 T2" is reference-compatible with "cv1 T1".
+  tcr = TryLValueToRValueCast(Self, SrcExpr.get(), DestType, CStyle, Kind, 
+                              BasePath, msg);
+  if (tcr != TC_NotApplicable)
+    return tcr;
+
+  // C++ 5.2.9p2: An expression e can be explicitly converted to a type T
+  //   [...] if the declaration "T t(e);" is well-formed, [...].
+  tcr = TryStaticImplicitCast(Self, SrcExpr, DestType, CCK, OpRange, msg,
+                              Kind, ListInitialization);
+  if (SrcExpr.isInvalid())
+    return TC_Failed;
+  if (tcr != TC_NotApplicable)
+    return tcr;
+  
+  // C++ 5.2.9p6: May apply the reverse of any standard conversion, except
+  // lvalue-to-rvalue, array-to-pointer, function-to-pointer, and boolean
+  // conversions, subject to further restrictions.
+  // Also, C++ 5.2.9p1 forbids casting away constness, which makes reversal
+  // of qualification conversions impossible.
+  // In the CStyle case, the earlier attempt to const_cast should have taken
+  // care of reverse qualification conversions.
+
+  QualType SrcType = Self.Context.getCanonicalType(SrcExpr.get()->getType());
+
+  // C++0x 5.2.9p9: A value of a scoped enumeration type can be explicitly
+  // converted to an integral type. [...] A value of a scoped enumeration type
+  // can also be explicitly converted to a floating-point type [...].
+  if (const EnumType *Enum = SrcType->getAs<EnumType>()) {
+    if (Enum->getDecl()->isScoped()) {
+      if (DestType->isBooleanType()) {
+        Kind = CK_IntegralToBoolean;
+        return TC_Success;
+      } else if (DestType->isIntegralType(Self.Context)) {
+        Kind = CK_IntegralCast;
+        return TC_Success;
+      } else if (DestType->isRealFloatingType()) {
+        Kind = CK_IntegralToFloating;
+        return TC_Success;
+      }
+    }
+  }
+  
+  // Reverse integral promotion/conversion. All such conversions are themselves
+  // again integral promotions or conversions and are thus already handled by
+  // p2 (TryDirectInitialization above).
+  // (Note: any data loss warnings should be suppressed.)
+  // The exception is the reverse of enum->integer, i.e. integer->enum (and
+  // enum->enum). See also C++ 5.2.9p7.
+  // The same goes for reverse floating point promotion/conversion and
+  // floating-integral conversions. Again, only floating->enum is relevant.
+  if (DestType->isEnumeralType()) {
+    if (SrcType->isIntegralOrEnumerationType()) {
+      Kind = CK_IntegralCast;
+      return TC_Success;
+    } else if (SrcType->isRealFloatingType())   {
+      Kind = CK_FloatingToIntegral;
+      return TC_Success;
+    }
+  }
+
+  // Reverse pointer upcast. C++ 4.10p3 specifies pointer upcast.
+  // C++ 5.2.9p8 additionally disallows a cast path through virtual inheritance.
+  tcr = TryStaticPointerDowncast(Self, SrcType, DestType, CStyle, OpRange, msg,
+                                 Kind, BasePath);
+  if (tcr != TC_NotApplicable)
+    return tcr;
+
+  // Reverse member pointer conversion. C++ 4.11 specifies member pointer
+  // conversion. C++ 5.2.9p9 has additional information.
+  // DR54's access restrictions apply here also.
+  tcr = TryStaticMemberPointerUpcast(Self, SrcExpr, SrcType, DestType, CStyle,
+                                     OpRange, msg, Kind, BasePath);
+  if (tcr != TC_NotApplicable)
+    return tcr;
+
+  // Reverse pointer conversion to void*. C++ 4.10.p2 specifies conversion to
+  // void*. C++ 5.2.9p10 specifies additional restrictions, which really is
+  // just the usual constness stuff.
+  if (const PointerType *SrcPointer = SrcType->getAs<PointerType>()) {
+    QualType SrcPointee = SrcPointer->getPointeeType();
+    if (SrcPointee->isVoidType()) {
+      if (const PointerType *DestPointer = DestType->getAs<PointerType>()) {
+        QualType DestPointee = DestPointer->getPointeeType();
+        if (DestPointee->isIncompleteOrObjectType()) {
+          // This is definitely the intended conversion, but it might fail due
+          // to a qualifier violation. Note that we permit Objective-C lifetime
+          // and GC qualifier mismatches here.
+          if (!CStyle) {
+            Qualifiers DestPointeeQuals = DestPointee.getQualifiers();
+            Qualifiers SrcPointeeQuals = SrcPointee.getQualifiers();
+            DestPointeeQuals.removeObjCGCAttr();
+            DestPointeeQuals.removeObjCLifetime();
+            SrcPointeeQuals.removeObjCGCAttr();
+            SrcPointeeQuals.removeObjCLifetime();
+            if (DestPointeeQuals != SrcPointeeQuals &&
+                !DestPointeeQuals.compatiblyIncludes(SrcPointeeQuals)) {
+              msg = diag::err_bad_cxx_cast_qualifiers_away;
+              return TC_Failed;
+            }
+          }
+          Kind = CK_BitCast;
+          return TC_Success;
+        }
+      }
+      else if (DestType->isObjCObjectPointerType()) {
+        // allow both c-style cast and static_cast of objective-c pointers as 
+        // they are pervasive.
+        Kind = CK_CPointerToObjCPointerCast;
+        return TC_Success;
+      }
+      else if (CStyle && DestType->isBlockPointerType()) {
+        // allow c-style cast of void * to block pointers.
+        Kind = CK_AnyPointerToBlockPointerCast;
+        return TC_Success;
+      }
+    }
+  }
+  // Allow arbitray objective-c pointer conversion with static casts.
+  if (SrcType->isObjCObjectPointerType() &&
+      DestType->isObjCObjectPointerType()) {
+    Kind = CK_BitCast;
+    return TC_Success;
+  }
+  
+  // We tried everything. Everything! Nothing works! :-(
+  return TC_NotApplicable;
+}
+
+/// Tests whether a conversion according to N2844 is valid.
+TryCastResult
+TryLValueToRValueCast(Sema &Self, Expr *SrcExpr, QualType DestType,
+                      bool CStyle, CastKind &Kind, CXXCastPath &BasePath, 
+                      unsigned &msg) {
+  // C++0x [expr.static.cast]p3:
+  //   A glvalue of type "cv1 T1" can be cast to type "rvalue reference to 
+  //   cv2 T2" if "cv2 T2" is reference-compatible with "cv1 T1".
+  const RValueReferenceType *R = DestType->getAs<RValueReferenceType>();
+  if (!R)
+    return TC_NotApplicable;
+
+  if (!SrcExpr->isGLValue())
+    return TC_NotApplicable;
+
+  // Because we try the reference downcast before this function, from now on
+  // this is the only cast possibility, so we issue an error if we fail now.
+  // FIXME: Should allow casting away constness if CStyle.
+  bool DerivedToBase;
+  bool ObjCConversion;
+  bool ObjCLifetimeConversion;
+  QualType FromType = SrcExpr->getType();
+  QualType ToType = R->getPointeeType();
+  if (CStyle) {
+    FromType = FromType.getUnqualifiedType();
+    ToType = ToType.getUnqualifiedType();
+  }
+  
+  if (Self.CompareReferenceRelationship(SrcExpr->getLocStart(),
+                                        ToType, FromType,
+                                        DerivedToBase, ObjCConversion,
+                                        ObjCLifetimeConversion) 
+        < Sema::Ref_Compatible_With_Added_Qualification) {
+    msg = diag::err_bad_lvalue_to_rvalue_cast;
+    return TC_Failed;
+  }
+
+  if (DerivedToBase) {
+    Kind = CK_DerivedToBase;
+    CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
+                       /*DetectVirtual=*/true);
+    if (!Self.IsDerivedFrom(SrcExpr->getType(), R->getPointeeType(), Paths))
+      return TC_NotApplicable;
+  
+    Self.BuildBasePathArray(Paths, BasePath);
+  } else
+    Kind = CK_NoOp;
+  
+  return TC_Success;
+}
+
+/// Tests whether a conversion according to C++ 5.2.9p5 is valid.
+TryCastResult
+TryStaticReferenceDowncast(Sema &Self, Expr *SrcExpr, QualType DestType,
+                           bool CStyle, const SourceRange &OpRange,
+                           unsigned &msg, CastKind &Kind,
+                           CXXCastPath &BasePath) {
+  // C++ 5.2.9p5: An lvalue of type "cv1 B", where B is a class type, can be
+  //   cast to type "reference to cv2 D", where D is a class derived from B,
+  //   if a valid standard conversion from "pointer to D" to "pointer to B"
+  //   exists, cv2 >= cv1, and B is not a virtual base class of D.
+  // In addition, DR54 clarifies that the base must be accessible in the
+  // current context. Although the wording of DR54 only applies to the pointer
+  // variant of this rule, the intent is clearly for it to apply to the this
+  // conversion as well.
+
+  const ReferenceType *DestReference = DestType->getAs<ReferenceType>();
+  if (!DestReference) {
+    return TC_NotApplicable;
+  }
+  bool RValueRef = DestReference->isRValueReferenceType();
+  if (!RValueRef && !SrcExpr->isLValue()) {
+    // We know the left side is an lvalue reference, so we can suggest a reason.
+    msg = diag::err_bad_cxx_cast_rvalue;
+    return TC_NotApplicable;
+  }
+
+  QualType DestPointee = DestReference->getPointeeType();
+
+  return TryStaticDowncast(Self, 
+                           Self.Context.getCanonicalType(SrcExpr->getType()), 
+                           Self.Context.getCanonicalType(DestPointee), CStyle,
+                           OpRange, SrcExpr->getType(), DestType, msg, Kind,
+                           BasePath);
+}
+
+/// Tests whether a conversion according to C++ 5.2.9p8 is valid.
+TryCastResult
+TryStaticPointerDowncast(Sema &Self, QualType SrcType, QualType DestType,
+                         bool CStyle, const SourceRange &OpRange,
+                         unsigned &msg, CastKind &Kind,
+                         CXXCastPath &BasePath) {
+  // C++ 5.2.9p8: An rvalue of type "pointer to cv1 B", where B is a class
+  //   type, can be converted to an rvalue of type "pointer to cv2 D", where D
+  //   is a class derived from B, if a valid standard conversion from "pointer
+  //   to D" to "pointer to B" exists, cv2 >= cv1, and B is not a virtual base
+  //   class of D.
+  // In addition, DR54 clarifies that the base must be accessible in the
+  // current context.
+
+  const PointerType *DestPointer = DestType->getAs<PointerType>();
+  if (!DestPointer) {
+    return TC_NotApplicable;
+  }
+
+  const PointerType *SrcPointer = SrcType->getAs<PointerType>();
+  if (!SrcPointer) {
+    msg = diag::err_bad_static_cast_pointer_nonpointer;
+    return TC_NotApplicable;
+  }
+
+  return TryStaticDowncast(Self, 
+                   Self.Context.getCanonicalType(SrcPointer->getPointeeType()),
+                  Self.Context.getCanonicalType(DestPointer->getPointeeType()), 
+                           CStyle, OpRange, SrcType, DestType, msg, Kind,
+                           BasePath);
+}
+
+/// TryStaticDowncast - Common functionality of TryStaticReferenceDowncast and
+/// TryStaticPointerDowncast. Tests whether a static downcast from SrcType to
+/// DestType is possible and allowed.
+TryCastResult
+TryStaticDowncast(Sema &Self, CanQualType SrcType, CanQualType DestType,
+                  bool CStyle, const SourceRange &OpRange, QualType OrigSrcType,
+                  QualType OrigDestType, unsigned &msg, 
+                  CastKind &Kind, CXXCastPath &BasePath) {
+  // We can only work with complete types. But don't complain if it doesn't work
+  if (Self.RequireCompleteType(OpRange.getBegin(), SrcType, Self.PDiag(0)) ||
+      Self.RequireCompleteType(OpRange.getBegin(), DestType, Self.PDiag(0)))
+    return TC_NotApplicable;
+
+  // Downcast can only happen in class hierarchies, so we need classes.
+  if (!DestType->getAs<RecordType>() || !SrcType->getAs<RecordType>()) {
+    return TC_NotApplicable;
+  }
+
+  CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
+                     /*DetectVirtual=*/true);
+  if (!Self.IsDerivedFrom(DestType, SrcType, Paths)) {
+    return TC_NotApplicable;
+  }
+
+  // Target type does derive from source type. Now we're serious. If an error
+  // appears now, it's not ignored.
+  // This may not be entirely in line with the standard. Take for example:
+  // struct A {};
+  // struct B : virtual A {
+  //   B(A&);
+  // };
+  //
+  // void f()
+  // {
+  //   (void)static_cast<const B&>(*((A*)0));
+  // }
+  // As far as the standard is concerned, p5 does not apply (A is virtual), so
+  // p2 should be used instead - "const B& t(*((A*)0));" is perfectly valid.
+  // However, both GCC and Comeau reject this example, and accepting it would
+  // mean more complex code if we're to preserve the nice error message.
+  // FIXME: Being 100% compliant here would be nice to have.
+
+  // Must preserve cv, as always, unless we're in C-style mode.
+  if (!CStyle && !DestType.isAtLeastAsQualifiedAs(SrcType)) {
+    msg = diag::err_bad_cxx_cast_qualifiers_away;
+    return TC_Failed;
+  }
+
+  if (Paths.isAmbiguous(SrcType.getUnqualifiedType())) {
+    // This code is analoguous to that in CheckDerivedToBaseConversion, except
+    // that it builds the paths in reverse order.
+    // To sum up: record all paths to the base and build a nice string from
+    // them. Use it to spice up the error message.
+    if (!Paths.isRecordingPaths()) {
+      Paths.clear();
+      Paths.setRecordingPaths(true);
+      Self.IsDerivedFrom(DestType, SrcType, Paths);
+    }
+    std::string PathDisplayStr;
+    std::set<unsigned> DisplayedPaths;
+    for (CXXBasePaths::paths_iterator PI = Paths.begin(), PE = Paths.end();
+         PI != PE; ++PI) {
+      if (DisplayedPaths.insert(PI->back().SubobjectNumber).second) {
+        // We haven't displayed a path to this particular base
+        // class subobject yet.
+        PathDisplayStr += "\n    ";
+        for (CXXBasePath::const_reverse_iterator EI = PI->rbegin(),
+                                                 EE = PI->rend();
+             EI != EE; ++EI)
+          PathDisplayStr += EI->Base->getType().getAsString() + " -> ";
+        PathDisplayStr += QualType(DestType).getAsString();
+      }
+    }
+
+    Self.Diag(OpRange.getBegin(), diag::err_ambiguous_base_to_derived_cast)
+      << QualType(SrcType).getUnqualifiedType() 
+      << QualType(DestType).getUnqualifiedType()
+      << PathDisplayStr << OpRange;
+    msg = 0;
+    return TC_Failed;
+  }
+
+  if (Paths.getDetectedVirtual() != 0) {
+    QualType VirtualBase(Paths.getDetectedVirtual(), 0);
+    Self.Diag(OpRange.getBegin(), diag::err_static_downcast_via_virtual)
+      << OrigSrcType << OrigDestType << VirtualBase << OpRange;
+    msg = 0;
+    return TC_Failed;
+  }
+
+  if (!CStyle) {
+    switch (Self.CheckBaseClassAccess(OpRange.getBegin(),
+                                      SrcType, DestType,
+                                      Paths.front(),
+                                diag::err_downcast_from_inaccessible_base)) {
+    case Sema::AR_accessible:
+    case Sema::AR_delayed:     // be optimistic
+    case Sema::AR_dependent:   // be optimistic
+      break;
+
+    case Sema::AR_inaccessible:
+      msg = 0;
+      return TC_Failed;
+    }
+  }
+
+  Self.BuildBasePathArray(Paths, BasePath);
+  Kind = CK_BaseToDerived;
+  return TC_Success;
+}
+
+/// TryStaticMemberPointerUpcast - Tests whether a conversion according to
+/// C++ 5.2.9p9 is valid:
+///
+///   An rvalue of type "pointer to member of D of type cv1 T" can be
+///   converted to an rvalue of type "pointer to member of B of type cv2 T",
+///   where B is a base class of D [...].
+///
+TryCastResult
+TryStaticMemberPointerUpcast(Sema &Self, ExprResult &SrcExpr, QualType SrcType, 
+                             QualType DestType, bool CStyle, 
+                             const SourceRange &OpRange,
+                             unsigned &msg, CastKind &Kind,
+                             CXXCastPath &BasePath) {
+  const MemberPointerType *DestMemPtr = DestType->getAs<MemberPointerType>();
+  if (!DestMemPtr)
+    return TC_NotApplicable;
+
+  bool WasOverloadedFunction = false;
+  DeclAccessPair FoundOverload;
+  if (SrcExpr.get()->getType() == Self.Context.OverloadTy) {
+    if (FunctionDecl *Fn
+          = Self.ResolveAddressOfOverloadedFunction(SrcExpr.get(), DestType, false,
+                                                    FoundOverload)) {
+      CXXMethodDecl *M = cast<CXXMethodDecl>(Fn);
+      SrcType = Self.Context.getMemberPointerType(Fn->getType(),
+                      Self.Context.getTypeDeclType(M->getParent()).getTypePtr());
+      WasOverloadedFunction = true;
+    }
+  }
+  
+  const MemberPointerType *SrcMemPtr = SrcType->getAs<MemberPointerType>();
+  if (!SrcMemPtr) {
+    msg = diag::err_bad_static_cast_member_pointer_nonmp;
+    return TC_NotApplicable;
+  }
+
+  // T == T, modulo cv
+  if (!Self.Context.hasSameUnqualifiedType(SrcMemPtr->getPointeeType(),
+                                           DestMemPtr->getPointeeType()))
+    return TC_NotApplicable;
+
+  // B base of D
+  QualType SrcClass(SrcMemPtr->getClass(), 0);
+  QualType DestClass(DestMemPtr->getClass(), 0);
+  CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
+                  /*DetectVirtual=*/true);
+  if (!Self.IsDerivedFrom(SrcClass, DestClass, Paths)) {
+    return TC_NotApplicable;
+  }
+
+  // B is a base of D. But is it an allowed base? If not, it's a hard error.
+  if (Paths.isAmbiguous(Self.Context.getCanonicalType(DestClass))) {
+    Paths.clear();
+    Paths.setRecordingPaths(true);
+    bool StillOkay = Self.IsDerivedFrom(SrcClass, DestClass, Paths);
+    assert(StillOkay);
+    (void)StillOkay;
+    std::string PathDisplayStr = Self.getAmbiguousPathsDisplayString(Paths);
+    Self.Diag(OpRange.getBegin(), diag::err_ambiguous_memptr_conv)
+      << 1 << SrcClass << DestClass << PathDisplayStr << OpRange;
+    msg = 0;
+    return TC_Failed;
+  }
+
+  if (const RecordType *VBase = Paths.getDetectedVirtual()) {
+    Self.Diag(OpRange.getBegin(), diag::err_memptr_conv_via_virtual)
+      << SrcClass << DestClass << QualType(VBase, 0) << OpRange;
+    msg = 0;
+    return TC_Failed;
+  }
+
+  if (!CStyle) {
+    switch (Self.CheckBaseClassAccess(OpRange.getBegin(),
+                                      DestClass, SrcClass,
+                                      Paths.front(),
+                                      diag::err_upcast_to_inaccessible_base)) {
+    case Sema::AR_accessible:
+    case Sema::AR_delayed:
+    case Sema::AR_dependent:
+      // Optimistically assume that the delayed and dependent cases
+      // will work out.
+      break;
+
+    case Sema::AR_inaccessible:
+      msg = 0;
+      return TC_Failed;
+    }
+  }
+
+  if (WasOverloadedFunction) {
+    // Resolve the address of the overloaded function again, this time
+    // allowing complaints if something goes wrong.
+    FunctionDecl *Fn = Self.ResolveAddressOfOverloadedFunction(SrcExpr.get(), 
+                                                               DestType, 
+                                                               true,
+                                                               FoundOverload);
+    if (!Fn) {
+      msg = 0;
+      return TC_Failed;
+    }
+
+    SrcExpr = Self.FixOverloadedFunctionReference(SrcExpr, FoundOverload, Fn);
+    if (!SrcExpr.isUsable()) {
+      msg = 0;
+      return TC_Failed;
+    }
+  }
+
+  Self.BuildBasePathArray(Paths, BasePath);
+  Kind = CK_DerivedToBaseMemberPointer;
+  return TC_Success;
+}
+
+/// TryStaticImplicitCast - Tests whether a conversion according to C++ 5.2.9p2
+/// is valid:
+///
+///   An expression e can be explicitly converted to a type T using a
+///   @c static_cast if the declaration "T t(e);" is well-formed [...].
+TryCastResult
+TryStaticImplicitCast(Sema &Self, ExprResult &SrcExpr, QualType DestType,
+                      Sema::CheckedConversionKind CCK, 
+                      const SourceRange &OpRange, unsigned &msg,
+                      CastKind &Kind, bool ListInitialization) {
+  if (DestType->isRecordType()) {
+    if (Self.RequireCompleteType(OpRange.getBegin(), DestType,
+                                 diag::err_bad_dynamic_cast_incomplete)) {
+      msg = 0;
+      return TC_Failed;
+    }
+  }
+
+  InitializedEntity Entity = InitializedEntity::InitializeTemporary(DestType);
+  InitializationKind InitKind
+    = (CCK == Sema::CCK_CStyleCast)
+        ? InitializationKind::CreateCStyleCast(OpRange.getBegin(), OpRange,
+                                               ListInitialization)
+    : (CCK == Sema::CCK_FunctionalCast)
+        ? InitializationKind::CreateFunctionalCast(OpRange, ListInitialization)
+    : InitializationKind::CreateCast(OpRange);
+  Expr *SrcExprRaw = SrcExpr.get();
+  InitializationSequence InitSeq(Self, Entity, InitKind, &SrcExprRaw, 1);
+
+  // At this point of CheckStaticCast, if the destination is a reference,
+  // or the expression is an overload expression this has to work. 
+  // There is no other way that works.
+  // On the other hand, if we're checking a C-style cast, we've still got
+  // the reinterpret_cast way.
+  bool CStyle 
+    = (CCK == Sema::CCK_CStyleCast || CCK == Sema::CCK_FunctionalCast);
+  if (InitSeq.Failed() && (CStyle || !DestType->isReferenceType()))
+    return TC_NotApplicable;
+    
+  ExprResult Result
+    = InitSeq.Perform(Self, Entity, InitKind, MultiExprArg(Self, &SrcExprRaw, 1));
+  if (Result.isInvalid()) {
+    msg = 0;
+    return TC_Failed;
+  }
+  
+  if (InitSeq.isConstructorInitialization())
+    Kind = CK_ConstructorConversion;
+  else
+    Kind = CK_NoOp;
+  
+  SrcExpr = move(Result);
+  return TC_Success;
+}
+
+/// TryConstCast - See if a const_cast from source to destination is allowed,
+/// and perform it if it is.
+static TryCastResult TryConstCast(Sema &Self, Expr *SrcExpr, QualType DestType,
+                                  bool CStyle, unsigned &msg) {
+  DestType = Self.Context.getCanonicalType(DestType);
+  QualType SrcType = SrcExpr->getType();
+  if (const ReferenceType *DestTypeTmp =DestType->getAs<ReferenceType>()) {
+    if (DestTypeTmp->isLValueReferenceType() && !SrcExpr->isLValue()) {
+      // Cannot const_cast non-lvalue to lvalue reference type. But if this
+      // is C-style, static_cast might find a way, so we simply suggest a
+      // message and tell the parent to keep searching.
+      msg = diag::err_bad_cxx_cast_rvalue;
+      return TC_NotApplicable;
+    }
+
+    // C++ 5.2.11p4: An lvalue of type T1 can be [cast] to an lvalue of type T2
+    //   [...] if a pointer to T1 can be [cast] to the type pointer to T2.
+    DestType = Self.Context.getPointerType(DestTypeTmp->getPointeeType());
+    SrcType = Self.Context.getPointerType(SrcType);
+  }
+
+  // C++ 5.2.11p5: For a const_cast involving pointers to data members [...]
+  //   the rules for const_cast are the same as those used for pointers.
+
+  if (!DestType->isPointerType() &&
+      !DestType->isMemberPointerType() &&
+      !DestType->isObjCObjectPointerType()) {
+    // Cannot cast to non-pointer, non-reference type. Note that, if DestType
+    // was a reference type, we converted it to a pointer above.
+    // The status of rvalue references isn't entirely clear, but it looks like
+    // conversion to them is simply invalid.
+    // C++ 5.2.11p3: For two pointer types [...]
+    if (!CStyle)
+      msg = diag::err_bad_const_cast_dest;
+    return TC_NotApplicable;
+  }
+  if (DestType->isFunctionPointerType() ||
+      DestType->isMemberFunctionPointerType()) {
+    // Cannot cast direct function pointers.
+    // C++ 5.2.11p2: [...] where T is any object type or the void type [...]
+    // T is the ultimate pointee of source and target type.
+    if (!CStyle)
+      msg = diag::err_bad_const_cast_dest;
+    return TC_NotApplicable;
+  }
+  SrcType = Self.Context.getCanonicalType(SrcType);
+
+  // Unwrap the pointers. Ignore qualifiers. Terminate early if the types are
+  // completely equal.
+  // C++ 5.2.11p3 describes the core semantics of const_cast. All cv specifiers
+  // in multi-level pointers may change, but the level count must be the same,
+  // as must be the final pointee type.
+  while (SrcType != DestType &&
+         Self.Context.UnwrapSimilarPointerTypes(SrcType, DestType)) {
+    Qualifiers SrcQuals, DestQuals;
+    SrcType = Self.Context.getUnqualifiedArrayType(SrcType, SrcQuals);
+    DestType = Self.Context.getUnqualifiedArrayType(DestType, DestQuals);
+    
+    // const_cast is permitted to strip cvr-qualifiers, only. Make sure that
+    // the other qualifiers (e.g., address spaces) are identical.
+    SrcQuals.removeCVRQualifiers();
+    DestQuals.removeCVRQualifiers();
+    if (SrcQuals != DestQuals)
+      return TC_NotApplicable;
+  }
+
+  // Since we're dealing in canonical types, the remainder must be the same.
+  if (SrcType != DestType)
+    return TC_NotApplicable;
+
+  return TC_Success;
+}
+
+// Checks for undefined behavior in reinterpret_cast.
+// The cases that is checked for is:
+// *reinterpret_cast<T*>(&a)
+// reinterpret_cast<T&>(a)
+// where accessing 'a' as type 'T' will result in undefined behavior.
+void Sema::CheckCompatibleReinterpretCast(QualType SrcType, QualType DestType,
+                                          bool IsDereference,
+                                          SourceRange Range) {
+  unsigned DiagID = IsDereference ?
+                        diag::warn_pointer_indirection_from_incompatible_type :
+                        diag::warn_undefined_reinterpret_cast;
+
+  if (Diags.getDiagnosticLevel(DiagID, Range.getBegin()) ==
+          DiagnosticsEngine::Ignored) {
+    return;
+  }
+
+  QualType SrcTy, DestTy;
+  if (IsDereference) {
+    if (!SrcType->getAs<PointerType>() || !DestType->getAs<PointerType>()) {
+      return;
+    }
+    SrcTy = SrcType->getPointeeType();
+    DestTy = DestType->getPointeeType();
+  } else {
+    if (!DestType->getAs<ReferenceType>()) {
+      return;
+    }
+    SrcTy = SrcType;
+    DestTy = DestType->getPointeeType();
+  }
+
+  // Cast is compatible if the types are the same.
+  if (Context.hasSameUnqualifiedType(DestTy, SrcTy)) {
+    return;
+  }
+  // or one of the types is a char or void type
+  if (DestTy->isAnyCharacterType() || DestTy->isVoidType() ||
+      SrcTy->isAnyCharacterType() || SrcTy->isVoidType()) {
+    return;
+  }
+  // or one of the types is a tag type.
+  if (SrcTy->getAs<TagType>() || DestTy->getAs<TagType>()) {
+    return;
+  }
+
+  // FIXME: Scoped enums?
+  if ((SrcTy->isUnsignedIntegerType() && DestTy->isSignedIntegerType()) ||
+      (SrcTy->isSignedIntegerType() && DestTy->isUnsignedIntegerType())) {
+    if (Context.getTypeSize(DestTy) == Context.getTypeSize(SrcTy)) {
+      return;
+    }
+  }
+
+  Diag(Range.getBegin(), DiagID) << SrcType << DestType << Range;
+}
+
+static TryCastResult TryReinterpretCast(Sema &Self, ExprResult &SrcExpr,
+                                        QualType DestType, bool CStyle,
+                                        const SourceRange &OpRange,
+                                        unsigned &msg,
+                                        CastKind &Kind) {
+  bool IsLValueCast = false;
+  
+  DestType = Self.Context.getCanonicalType(DestType);
+  QualType SrcType = SrcExpr.get()->getType();
+
+  // Is the source an overloaded name? (i.e. &foo)
+  // If so, reinterpret_cast can not help us here (13.4, p1, bullet 5) ...
+  if (SrcType == Self.Context.OverloadTy) {
+    // ... unless foo<int> resolves to an lvalue unambiguously.
+    // TODO: what if this fails because of DiagnoseUseOfDecl or something
+    // like it?
+    ExprResult SingleFunctionExpr = SrcExpr;
+    if (Self.ResolveAndFixSingleFunctionTemplateSpecialization(
+          SingleFunctionExpr,
+          Expr::getValueKindForType(DestType) == VK_RValue // Convert Fun to Ptr 
+        ) && SingleFunctionExpr.isUsable()) {
+      SrcExpr = move(SingleFunctionExpr);
+      SrcType = SrcExpr.get()->getType();
+    } else {
+      return TC_NotApplicable;
+    }
+  }
+
+  if (const ReferenceType *DestTypeTmp = DestType->getAs<ReferenceType>()) {
+    bool LValue = DestTypeTmp->isLValueReferenceType();
+    if (LValue && !SrcExpr.get()->isLValue()) {
+      // Cannot cast non-lvalue to lvalue reference type. See the similar 
+      // comment in const_cast.
+      msg = diag::err_bad_cxx_cast_rvalue;
+      return TC_NotApplicable;
+    }
+
+    if (!CStyle) {
+      Self.CheckCompatibleReinterpretCast(SrcType, DestType,
+                                          /*isDereference=*/false, OpRange);
+    }
+
+    // C++ 5.2.10p10: [...] a reference cast reinterpret_cast<T&>(x) has the
+    //   same effect as the conversion *reinterpret_cast<T*>(&x) with the
+    //   built-in & and * operators.
+
+    const char *inappropriate = 0;
+    switch (SrcExpr.get()->getObjectKind()) {
+    case OK_Ordinary:
+      break;
+    case OK_BitField:        inappropriate = "bit-field";           break;
+    case OK_VectorComponent: inappropriate = "vector element";      break;
+    case OK_ObjCProperty:    inappropriate = "property expression"; break;
+    case OK_ObjCSubscript:   inappropriate = "container subscripting expression"; 
+                             break;
+    }
+    if (inappropriate) {
+      Self.Diag(OpRange.getBegin(), diag::err_bad_reinterpret_cast_reference)
+          << inappropriate << DestType
+          << OpRange << SrcExpr.get()->getSourceRange();
+      msg = 0; SrcExpr = ExprError();
+      return TC_NotApplicable;
+    }
+
+    // This code does this transformation for the checked types.
+    DestType = Self.Context.getPointerType(DestTypeTmp->getPointeeType());
+    SrcType = Self.Context.getPointerType(SrcType);
+    
+    IsLValueCast = true;
+  }
+
+  // Canonicalize source for comparison.
+  SrcType = Self.Context.getCanonicalType(SrcType);
+
+  const MemberPointerType *DestMemPtr = DestType->getAs<MemberPointerType>(),
+                          *SrcMemPtr = SrcType->getAs<MemberPointerType>();
+  if (DestMemPtr && SrcMemPtr) {
+    // C++ 5.2.10p9: An rvalue of type "pointer to member of X of type T1"
+    //   can be explicitly converted to an rvalue of type "pointer to member
+    //   of Y of type T2" if T1 and T2 are both function types or both object
+    //   types.
+    if (DestMemPtr->getPointeeType()->isFunctionType() !=
+        SrcMemPtr->getPointeeType()->isFunctionType())
+      return TC_NotApplicable;
+
+    // C++ 5.2.10p2: The reinterpret_cast operator shall not cast away
+    //   constness.
+    // A reinterpret_cast followed by a const_cast can, though, so in C-style,
+    // we accept it.
+    if (CastsAwayConstness(Self, SrcType, DestType, /*CheckCVR=*/!CStyle,
+                           /*CheckObjCLifetime=*/CStyle)) {
+      msg = diag::err_bad_cxx_cast_qualifiers_away;
+      return TC_Failed;
+    }
+
+    // Don't allow casting between member pointers of different sizes.
+    if (Self.Context.getTypeSize(DestMemPtr) !=
+        Self.Context.getTypeSize(SrcMemPtr)) {
+      msg = diag::err_bad_cxx_cast_member_pointer_size;
+      return TC_Failed;
+    }
+
+    // A valid member pointer cast.
+    assert(!IsLValueCast);
+    Kind = CK_ReinterpretMemberPointer;
+    return TC_Success;
+  }
+
+  // See below for the enumeral issue.
+  if (SrcType->isNullPtrType() && DestType->isIntegralType(Self.Context)) {
+    // C++0x 5.2.10p4: A pointer can be explicitly converted to any integral
+    //   type large enough to hold it. A value of std::nullptr_t can be
+    //   converted to an integral type; the conversion has the same meaning
+    //   and validity as a conversion of (void*)0 to the integral type.
+    if (Self.Context.getTypeSize(SrcType) >
+        Self.Context.getTypeSize(DestType)) {
+      msg = diag::err_bad_reinterpret_cast_small_int;
+      return TC_Failed;
+    }
+    Kind = CK_PointerToIntegral;
+    return TC_Success;
+  }
+
+  bool destIsVector = DestType->isVectorType();
+  bool srcIsVector = SrcType->isVectorType();
+  if (srcIsVector || destIsVector) {
+    // FIXME: Should this also apply to floating point types?
+    bool srcIsScalar = SrcType->isIntegralType(Self.Context);
+    bool destIsScalar = DestType->isIntegralType(Self.Context);
+    
+    // Check if this is a cast between a vector and something else.
+    if (!(srcIsScalar && destIsVector) && !(srcIsVector && destIsScalar) &&
+        !(srcIsVector && destIsVector))
+      return TC_NotApplicable;
+
+    // If both types have the same size, we can successfully cast.
+    if (Self.Context.getTypeSize(SrcType)
+          == Self.Context.getTypeSize(DestType)) {
+      Kind = CK_BitCast;
+      return TC_Success;
+    }
+    
+    if (destIsScalar)
+      msg = diag::err_bad_cxx_cast_vector_to_scalar_different_size;
+    else if (srcIsScalar)
+      msg = diag::err_bad_cxx_cast_scalar_to_vector_different_size;
+    else
+      msg = diag::err_bad_cxx_cast_vector_to_vector_different_size;
+    
+    return TC_Failed;
+  }
+
+  if (SrcType == DestType) {
+    // C++ 5.2.10p2 has a note that mentions that, subject to all other
+    // restrictions, a cast to the same type is allowed so long as it does not
+    // cast away constness. In C++98, the intent was not entirely clear here, 
+    // since all other paragraphs explicitly forbid casts to the same type.
+    // C++11 clarifies this case with p2.
+    //
+    // The only allowed types are: integral, enumeration, pointer, or 
+    // pointer-to-member types.  We also won't restrict Obj-C pointers either.
+    Kind = CK_NoOp;
+    TryCastResult Result = TC_NotApplicable;
+    if (SrcType->isIntegralOrEnumerationType() ||
+        SrcType->isAnyPointerType() ||
+        SrcType->isMemberPointerType() ||
+        SrcType->isBlockPointerType()) {
+      Result = TC_Success;
+    }
+    return Result;
+  }
+
+  bool destIsPtr = DestType->isAnyPointerType() ||
+                   DestType->isBlockPointerType();
+  bool srcIsPtr = SrcType->isAnyPointerType() ||
+                  SrcType->isBlockPointerType();
+  if (!destIsPtr && !srcIsPtr) {
+    // Except for std::nullptr_t->integer and lvalue->reference, which are
+    // handled above, at least one of the two arguments must be a pointer.
+    return TC_NotApplicable;
+  }
+
+  if (DestType->isIntegralType(Self.Context)) {
+    assert(srcIsPtr && "One type must be a pointer");
+    // C++ 5.2.10p4: A pointer can be explicitly converted to any integral
+    //   type large enough to hold it; except in Microsoft mode, where the
+    //   integral type size doesn't matter.
+    if ((Self.Context.getTypeSize(SrcType) >
+         Self.Context.getTypeSize(DestType)) &&
+         !Self.getLangOpts().MicrosoftExt) {
+      msg = diag::err_bad_reinterpret_cast_small_int;
+      return TC_Failed;
+    }
+    Kind = CK_PointerToIntegral;
+    return TC_Success;
+  }
+
+  if (SrcType->isIntegralOrEnumerationType()) {
+    assert(destIsPtr && "One type must be a pointer");
+    // C++ 5.2.10p5: A value of integral or enumeration type can be explicitly
+    //   converted to a pointer.
+    // C++ 5.2.10p9: [Note: ...a null pointer constant of integral type is not
+    //   necessarily converted to a null pointer value.]
+    Kind = CK_IntegralToPointer;
+    return TC_Success;
+  }
+
+  if (!destIsPtr || !srcIsPtr) {
+    // With the valid non-pointer conversions out of the way, we can be even
+    // more stringent.
+    return TC_NotApplicable;
+  }
+
+  // C++ 5.2.10p2: The reinterpret_cast operator shall not cast away constness.
+  // The C-style cast operator can.
+  if (CastsAwayConstness(Self, SrcType, DestType, /*CheckCVR=*/!CStyle,
+                         /*CheckObjCLifetime=*/CStyle)) {
+    msg = diag::err_bad_cxx_cast_qualifiers_away;
+    return TC_Failed;
+  }
+  
+  // Cannot convert between block pointers and Objective-C object pointers.
+  if ((SrcType->isBlockPointerType() && DestType->isObjCObjectPointerType()) ||
+      (DestType->isBlockPointerType() && SrcType->isObjCObjectPointerType()))
+    return TC_NotApplicable;
+
+  if (IsLValueCast) {
+    Kind = CK_LValueBitCast;
+  } else if (DestType->isObjCObjectPointerType()) {
+    Kind = Self.PrepareCastToObjCObjectPointer(SrcExpr);
+  } else if (DestType->isBlockPointerType()) {
+    if (!SrcType->isBlockPointerType()) {
+      Kind = CK_AnyPointerToBlockPointerCast;
+    } else {
+      Kind = CK_BitCast;
+    }
+  } else {
+    Kind = CK_BitCast;
+  }
+
+  // Any pointer can be cast to an Objective-C pointer type with a C-style
+  // cast.
+  if (CStyle && DestType->isObjCObjectPointerType()) {
+    return TC_Success;
+  }
+    
+  // Not casting away constness, so the only remaining check is for compatible
+  // pointer categories.
+
+  if (SrcType->isFunctionPointerType()) {
+    if (DestType->isFunctionPointerType()) {
+      // C++ 5.2.10p6: A pointer to a function can be explicitly converted to
+      // a pointer to a function of a different type.
+      return TC_Success;
+    }
+
+    // C++0x 5.2.10p8: Converting a pointer to a function into a pointer to
+    //   an object type or vice versa is conditionally-supported.
+    // Compilers support it in C++03 too, though, because it's necessary for
+    // casting the return value of dlsym() and GetProcAddress().
+    // FIXME: Conditionally-supported behavior should be configurable in the
+    // TargetInfo or similar.
+    Self.Diag(OpRange.getBegin(),
+              Self.getLangOpts().CPlusPlus0x ?
+                diag::warn_cxx98_compat_cast_fn_obj : diag::ext_cast_fn_obj)
+      << OpRange;
+    return TC_Success;
+  }
+
+  if (DestType->isFunctionPointerType()) {
+    // See above.
+    Self.Diag(OpRange.getBegin(),
+              Self.getLangOpts().CPlusPlus0x ?
+                diag::warn_cxx98_compat_cast_fn_obj : diag::ext_cast_fn_obj)
+      << OpRange;
+    return TC_Success;
+  }
+  
+  // C++ 5.2.10p7: A pointer to an object can be explicitly converted to
+  //   a pointer to an object of different type.
+  // Void pointers are not specified, but supported by every compiler out there.
+  // So we finish by allowing everything that remains - it's got to be two
+  // object pointers.
+  return TC_Success;
+}                                     
+
+void CastOperation::CheckCXXCStyleCast(bool FunctionalStyle,
+                                       bool ListInitialization) {
+  // Handle placeholders.
+  if (isPlaceholder()) {
+    // C-style casts can resolve __unknown_any types.
+    if (claimPlaceholder(BuiltinType::UnknownAny)) {
+      SrcExpr = Self.checkUnknownAnyCast(DestRange, DestType,
+                                         SrcExpr.get(), Kind,
+                                         ValueKind, BasePath);
+      return;
+    }
+
+    checkNonOverloadPlaceholders();
+    if (SrcExpr.isInvalid())
+      return;
+  }
+
+  // C++ 5.2.9p4: Any expression can be explicitly converted to type "cv void".
+  // This test is outside everything else because it's the only case where
+  // a non-lvalue-reference target type does not lead to decay.
+  if (DestType->isVoidType()) {
+    Kind = CK_ToVoid;
+
+    if (claimPlaceholder(BuiltinType::Overload)) {
+      Self.ResolveAndFixSingleFunctionTemplateSpecialization(
+                  SrcExpr, /* Decay Function to ptr */ false, 
+                  /* Complain */ true, DestRange, DestType,
+                  diag::err_bad_cstyle_cast_overload);
+      if (SrcExpr.isInvalid())
+        return;
+    }
+
+    SrcExpr = Self.IgnoredValueConversions(SrcExpr.take());
+    if (SrcExpr.isInvalid())
+      return;
+
+    return;
+  }
+
+  // If the type is dependent, we won't do any other semantic analysis now.
+  if (DestType->isDependentType() || SrcExpr.get()->isTypeDependent()) {
+    assert(Kind == CK_Dependent);
+    return;
+  }
+
+  if (ValueKind == VK_RValue && !DestType->isRecordType() &&
+      !isPlaceholder(BuiltinType::Overload)) {
+    SrcExpr = Self.DefaultFunctionArrayLvalueConversion(SrcExpr.take());
+    if (SrcExpr.isInvalid())
+      return;
+  }
+
+  // AltiVec vector initialization with a single literal.
+  if (const VectorType *vecTy = DestType->getAs<VectorType>())
+    if (vecTy->getVectorKind() == VectorType::AltiVecVector
+        && (SrcExpr.get()->getType()->isIntegerType()
+            || SrcExpr.get()->getType()->isFloatingType())) {
+      Kind = CK_VectorSplat;
+      return;
+    }
+
+  // C++ [expr.cast]p5: The conversions performed by
+  //   - a const_cast,
+  //   - a static_cast,
+  //   - a static_cast followed by a const_cast,
+  //   - a reinterpret_cast, or
+  //   - a reinterpret_cast followed by a const_cast,
+  //   can be performed using the cast notation of explicit type conversion.
+  //   [...] If a conversion can be interpreted in more than one of the ways
+  //   listed above, the interpretation that appears first in the list is used,
+  //   even if a cast resulting from that interpretation is ill-formed.
+  // In plain language, this means trying a const_cast ...
+  unsigned msg = diag::err_bad_cxx_cast_generic;
+  TryCastResult tcr = TryConstCast(Self, SrcExpr.get(), DestType,
+                                   /*CStyle*/true, msg);
+  if (tcr == TC_Success)
+    Kind = CK_NoOp;
+
+  Sema::CheckedConversionKind CCK
+    = FunctionalStyle? Sema::CCK_FunctionalCast
+                     : Sema::CCK_CStyleCast;
+  if (tcr == TC_NotApplicable) {
+    // ... or if that is not possible, a static_cast, ignoring const, ...
+    tcr = TryStaticCast(Self, SrcExpr, DestType, CCK, OpRange,
+                        msg, Kind, BasePath, ListInitialization);
+    if (SrcExpr.isInvalid())
+      return;
+
+    if (tcr == TC_NotApplicable) {
+      // ... and finally a reinterpret_cast, ignoring const.
+      tcr = TryReinterpretCast(Self, SrcExpr, DestType, /*CStyle*/true,
+                               OpRange, msg, Kind);
+      if (SrcExpr.isInvalid())
+        return;
+    }
+  }
+
+  if (Self.getLangOpts().ObjCAutoRefCount && tcr == TC_Success)
+    checkObjCARCConversion(CCK);
+
+  if (tcr != TC_Success && msg != 0) {
+    if (SrcExpr.get()->getType() == Self.Context.OverloadTy) {
+      DeclAccessPair Found;
+      FunctionDecl *Fn = Self.ResolveAddressOfOverloadedFunction(SrcExpr.get(),
+                                DestType,
+                                /*Complain*/ true,
+                                Found);
+      
+      assert(!Fn && "cast failed but able to resolve overload expression!!");
+      (void)Fn;
+
+    } else {
+      diagnoseBadCast(Self, msg, (FunctionalStyle ? CT_Functional : CT_CStyle),
+                      OpRange, SrcExpr.get(), DestType, ListInitialization);
+    }
+  } else if (Kind == CK_BitCast) {
+    checkCastAlign();
+  }
+
+  // Clear out SrcExpr if there was a fatal error.
+  if (tcr != TC_Success)
+    SrcExpr = ExprError();
+}
+
+/// Check the semantics of a C-style cast operation, in C.
+void CastOperation::CheckCStyleCast() {
+  assert(!Self.getLangOpts().CPlusPlus);
+
+  // C-style casts can resolve __unknown_any types.
+  if (claimPlaceholder(BuiltinType::UnknownAny)) {
+    SrcExpr = Self.checkUnknownAnyCast(DestRange, DestType,
+                                       SrcExpr.get(), Kind,
+                                       ValueKind, BasePath);
+    return;
+  }
+
+  // C99 6.5.4p2: the cast type needs to be void or scalar and the expression
+  // type needs to be scalar.
+  if (DestType->isVoidType()) {
+    // We don't necessarily do lvalue-to-rvalue conversions on this.
+    SrcExpr = Self.IgnoredValueConversions(SrcExpr.take());
+    if (SrcExpr.isInvalid())
+      return;
+
+    // Cast to void allows any expr type.
+    Kind = CK_ToVoid;
+    return;
+  }
+
+  SrcExpr = Self.DefaultFunctionArrayLvalueConversion(SrcExpr.take());
+  if (SrcExpr.isInvalid())
+    return;
+  QualType SrcType = SrcExpr.get()->getType();
+
+  // You can cast an _Atomic(T) to anything you can cast a T to.
+  if (const AtomicType *AtomicSrcType = SrcType->getAs<AtomicType>())
+    SrcType = AtomicSrcType->getValueType();
+
+  assert(!SrcType->isPlaceholderType());
+
+  if (Self.RequireCompleteType(OpRange.getBegin(), DestType,
+                               diag::err_typecheck_cast_to_incomplete)) {
+    SrcExpr = ExprError();
+    return;
+  }
+
+  if (!DestType->isScalarType() && !DestType->isVectorType()) {
+    const RecordType *DestRecordTy = DestType->getAs<RecordType>();
+
+    if (DestRecordTy && Self.Context.hasSameUnqualifiedType(DestType, SrcType)){
+      // GCC struct/union extension: allow cast to self.
+      Self.Diag(OpRange.getBegin(), diag::ext_typecheck_cast_nonscalar)
+        << DestType << SrcExpr.get()->getSourceRange();
+      Kind = CK_NoOp;
+      return;
+    }
+
+    // GCC's cast to union extension.
+    if (DestRecordTy && DestRecordTy->getDecl()->isUnion()) {
+      RecordDecl *RD = DestRecordTy->getDecl();
+      RecordDecl::field_iterator Field, FieldEnd;
+      for (Field = RD->field_begin(), FieldEnd = RD->field_end();
+           Field != FieldEnd; ++Field) {
+        if (Self.Context.hasSameUnqualifiedType(Field->getType(), SrcType) &&
+            !Field->isUnnamedBitfield()) {
+          Self.Diag(OpRange.getBegin(), diag::ext_typecheck_cast_to_union)
+            << SrcExpr.get()->getSourceRange();
+          break;
+        }
+      }
+      if (Field == FieldEnd) {
+        Self.Diag(OpRange.getBegin(), diag::err_typecheck_cast_to_union_no_type)
+          << SrcType << SrcExpr.get()->getSourceRange();
+        SrcExpr = ExprError();
+        return;
+      }
+      Kind = CK_ToUnion;
+      return;
+    }
+
+    // Reject any other conversions to non-scalar types.
+    Self.Diag(OpRange.getBegin(), diag::err_typecheck_cond_expect_scalar)
+      << DestType << SrcExpr.get()->getSourceRange();
+    SrcExpr = ExprError();
+    return;
+  }
+
+  // The type we're casting to is known to be a scalar or vector.
+
+  // Require the operand to be a scalar or vector.
+  if (!SrcType->isScalarType() && !SrcType->isVectorType()) {
+    Self.Diag(SrcExpr.get()->getExprLoc(),
+              diag::err_typecheck_expect_scalar_operand)
+      << SrcType << SrcExpr.get()->getSourceRange();
+    SrcExpr = ExprError();
+    return;
+  }
+
+  if (DestType->isExtVectorType()) {
+    SrcExpr = Self.CheckExtVectorCast(OpRange, DestType, SrcExpr.take(), Kind);
+    return;
+  }
+
+  if (const VectorType *DestVecTy = DestType->getAs<VectorType>()) {
+    if (DestVecTy->getVectorKind() == VectorType::AltiVecVector &&
+          (SrcType->isIntegerType() || SrcType->isFloatingType())) {
+      Kind = CK_VectorSplat;
+    } else if (Self.CheckVectorCast(OpRange, DestType, SrcType, Kind)) {
+      SrcExpr = ExprError();
+    }
+    return;
+  }
+
+  if (SrcType->isVectorType()) {
+    if (Self.CheckVectorCast(OpRange, SrcType, DestType, Kind))
+      SrcExpr = ExprError();
+    return;
+  }
+
+  // The source and target types are both scalars, i.e.
+  //   - arithmetic types (fundamental, enum, and complex)
+  //   - all kinds of pointers
+  // Note that member pointers were filtered out with C++, above.
+
+  if (isa<ObjCSelectorExpr>(SrcExpr.get())) {
+    Self.Diag(SrcExpr.get()->getExprLoc(), diag::err_cast_selector_expr);
+    SrcExpr = ExprError();
+    return;
+  }
+
+  // If either type is a pointer, the other type has to be either an
+  // integer or a pointer.
+  if (!DestType->isArithmeticType()) {
+    if (!SrcType->isIntegralType(Self.Context) && SrcType->isArithmeticType()) {
+      Self.Diag(SrcExpr.get()->getExprLoc(),
+                diag::err_cast_pointer_from_non_pointer_int)
+        << SrcType << SrcExpr.get()->getSourceRange();
+      SrcExpr = ExprError();
+      return;
+    }
+  } else if (!SrcType->isArithmeticType()) {
+    if (!DestType->isIntegralType(Self.Context) &&
+        DestType->isArithmeticType()) {
+      Self.Diag(SrcExpr.get()->getLocStart(),
+           diag::err_cast_pointer_to_non_pointer_int)
+        << DestType << SrcExpr.get()->getSourceRange();
+      SrcExpr = ExprError();
+      return;
+    }
+  }
+
+  // ARC imposes extra restrictions on casts.
+  if (Self.getLangOpts().ObjCAutoRefCount) {
+    checkObjCARCConversion(Sema::CCK_CStyleCast);
+    if (SrcExpr.isInvalid())
+      return;
+    
+    if (const PointerType *CastPtr = DestType->getAs<PointerType>()) {
+      if (const PointerType *ExprPtr = SrcType->getAs<PointerType>()) {
+        Qualifiers CastQuals = CastPtr->getPointeeType().getQualifiers();
+        Qualifiers ExprQuals = ExprPtr->getPointeeType().getQualifiers();
+        if (CastPtr->getPointeeType()->isObjCLifetimeType() && 
+            ExprPtr->getPointeeType()->isObjCLifetimeType() &&
+            !CastQuals.compatiblyIncludesObjCLifetime(ExprQuals)) {
+          Self.Diag(SrcExpr.get()->getLocStart(), 
+                    diag::err_typecheck_incompatible_ownership)
+            << SrcType << DestType << Sema::AA_Casting
+            << SrcExpr.get()->getSourceRange();
+          return;
+        }
+      }
+    } 
+    else if (!Self.CheckObjCARCUnavailableWeakConversion(DestType, SrcType)) {
+      Self.Diag(SrcExpr.get()->getLocStart(), 
+                diag::err_arc_convesion_of_weak_unavailable)
+        << 1 << SrcType << DestType << SrcExpr.get()->getSourceRange();
+      SrcExpr = ExprError();
+      return;
+    }
+  }
+  
+  Kind = Self.PrepareScalarCast(SrcExpr, DestType);
+  if (SrcExpr.isInvalid())
+    return;
+
+  if (Kind == CK_BitCast)
+    checkCastAlign();
+}
+
+ExprResult Sema::BuildCStyleCastExpr(SourceLocation LPLoc,
+                                     TypeSourceInfo *CastTypeInfo,
+                                     SourceLocation RPLoc,
+                                     Expr *CastExpr) {
+  CastOperation Op(*this, CastTypeInfo->getType(), CastExpr);  
+  Op.DestRange = CastTypeInfo->getTypeLoc().getSourceRange();
+  Op.OpRange = SourceRange(LPLoc, CastExpr->getLocEnd());
+
+  if (getLangOpts().CPlusPlus) {
+    Op.CheckCXXCStyleCast(/*FunctionalStyle=*/ false,
+                          isa<InitListExpr>(CastExpr));
+  } else {
+    Op.CheckCStyleCast();
+  }
+
+  if (Op.SrcExpr.isInvalid())
+    return ExprError();
+
+  return Op.complete(CStyleCastExpr::Create(Context, Op.ResultType,
+                              Op.ValueKind, Op.Kind, Op.SrcExpr.take(),
+                              &Op.BasePath, CastTypeInfo, LPLoc, RPLoc));
+}
+
+ExprResult Sema::BuildCXXFunctionalCastExpr(TypeSourceInfo *CastTypeInfo,
+                                            SourceLocation LPLoc,
+                                            Expr *CastExpr,
+                                            SourceLocation RPLoc) {
+  assert(LPLoc.isValid() && "List-initialization shouldn't get here.");
+  CastOperation Op(*this, CastTypeInfo->getType(), CastExpr);
+  Op.DestRange = CastTypeInfo->getTypeLoc().getSourceRange();
+  Op.OpRange = SourceRange(Op.DestRange.getBegin(), CastExpr->getLocEnd());
+
+  Op.CheckCXXCStyleCast(/*FunctionalStyle=*/true, /*ListInit=*/false);
+  if (Op.SrcExpr.isInvalid())
+    return ExprError();
+
+  return Op.complete(CXXFunctionalCastExpr::Create(Context, Op.ResultType,
+                         Op.ValueKind, CastTypeInfo, Op.DestRange.getBegin(),
+                         Op.Kind, Op.SrcExpr.take(), &Op.BasePath, RPLoc));
+}