diff --git a/lib/Sema/AttributeList.cpp b/lib/Sema/AttributeList.cpp
index 0f209fd..7c79879 100644
--- a/lib/Sema/AttributeList.cpp
+++ b/lib/Sema/AttributeList.cpp
@@ -21,6 +21,8 @@
 
 size_t AttributeList::allocated_size() const {
   if (IsAvailability) return AttributeFactory::AvailabilityAllocSize;
+  else if (IsTypeTagForDatatype)
+    return AttributeFactory::TypeTagForDatatypeAllocSize;
   return (sizeof(AttributeList) + NumArgs * sizeof(Expr*));
 }
 
diff --git a/lib/Sema/SemaChecking.cpp b/lib/Sema/SemaChecking.cpp
index 3702861..2559f00 100644
--- a/lib/Sema/SemaChecking.cpp
+++ b/lib/Sema/SemaChecking.cpp
@@ -513,6 +513,13 @@
          I = FDecl->specific_attr_begin<NonNullAttr>(),
          E = FDecl->specific_attr_end<NonNullAttr>(); I != E; ++I)
     CheckNonNullArguments(*I, Args, Loc);
+
+  // Type safety checking.
+  for (specific_attr_iterator<ArgumentWithTypeTagAttr>
+         i = FDecl->specific_attr_begin<ArgumentWithTypeTagAttr>(),
+         e = FDecl->specific_attr_end<ArgumentWithTypeTagAttr>(); i != e; ++i) {
+    CheckArgumentWithTypeTag(*i, Args);
+  }
 }
 
 /// CheckConstructorCall - Check a constructor call for correctness and safety
@@ -5468,3 +5475,410 @@
     Diag(NBody->getSemiLoc(), diag::note_empty_body_on_separate_line);
   }
 }
+
+//===--- Layout compatibility ----------------------------------------------//
+
+namespace {
+
+bool isLayoutCompatible(ASTContext &C, QualType T1, QualType T2);
+
+/// \brief Check if two enumeration types are layout-compatible.
+bool isLayoutCompatible(ASTContext &C, EnumDecl *ED1, EnumDecl *ED2) {
+  // C++11 [dcl.enum] p8:
+  // Two enumeration types are layout-compatible if they have the same
+  // underlying type.
+  return ED1->isComplete() && ED2->isComplete() &&
+         C.hasSameType(ED1->getIntegerType(), ED2->getIntegerType());
+}
+
+/// \brief Check if two fields are layout-compatible.
+bool isLayoutCompatible(ASTContext &C, FieldDecl *Field1, FieldDecl *Field2) {
+  if (!isLayoutCompatible(C, Field1->getType(), Field2->getType()))
+    return false;
+
+  if (Field1->isBitField() != Field2->isBitField())
+    return false;
+
+  if (Field1->isBitField()) {
+    // Make sure that the bit-fields are the same length.
+    unsigned Bits1 = Field1->getBitWidthValue(C);
+    unsigned Bits2 = Field2->getBitWidthValue(C);
+
+    if (Bits1 != Bits2)
+      return false;
+  }
+
+  return true;
+}
+
+/// \brief Check if two standard-layout structs are layout-compatible.
+/// (C++11 [class.mem] p17)
+bool isLayoutCompatibleStruct(ASTContext &C,
+                              RecordDecl *RD1,
+                              RecordDecl *RD2) {
+  // If both records are C++ classes, check that base classes match.
+  if (const CXXRecordDecl *D1CXX = dyn_cast<CXXRecordDecl>(RD1)) {
+    // If one of records is a CXXRecordDecl we are in C++ mode,
+    // thus the other one is a CXXRecordDecl, too.
+    const CXXRecordDecl *D2CXX = cast<CXXRecordDecl>(RD2);
+    // Check number of base classes.
+    if (D1CXX->getNumBases() != D2CXX->getNumBases())
+      return false;
+
+    // Check the base classes.
+    for (CXXRecordDecl::base_class_const_iterator
+               Base1 = D1CXX->bases_begin(),
+           BaseEnd1 = D1CXX->bases_end(),
+              Base2 = D2CXX->bases_begin();
+         Base1 != BaseEnd1;
+         ++Base1, ++Base2) {
+      if (!isLayoutCompatible(C, Base1->getType(), Base2->getType()))
+        return false;
+    }
+  } else if (const CXXRecordDecl *D2CXX = dyn_cast<CXXRecordDecl>(RD2)) {
+    // If only RD2 is a C++ class, it should have zero base classes.
+    if (D2CXX->getNumBases() > 0)
+      return false;
+  }
+
+  // Check the fields.
+  RecordDecl::field_iterator Field2 = RD2->field_begin(),
+                             Field2End = RD2->field_end(),
+                             Field1 = RD1->field_begin(),
+                             Field1End = RD1->field_end();
+  for ( ; Field1 != Field1End && Field2 != Field2End; ++Field1, ++Field2) {
+    if (!isLayoutCompatible(C, *Field1, *Field2))
+      return false;
+  }
+  if (Field1 != Field1End || Field2 != Field2End)
+    return false;
+
+  return true;
+}
+
+/// \brief Check if two standard-layout unions are layout-compatible.
+/// (C++11 [class.mem] p18)
+bool isLayoutCompatibleUnion(ASTContext &C,
+                             RecordDecl *RD1,
+                             RecordDecl *RD2) {
+  llvm::SmallPtrSet<FieldDecl *, 8> UnmatchedFields;
+  for (RecordDecl::field_iterator Field2 = RD2->field_begin(),
+                                  Field2End = RD2->field_end();
+       Field2 != Field2End; ++Field2) {
+    UnmatchedFields.insert(*Field2);
+  }
+
+  for (RecordDecl::field_iterator Field1 = RD1->field_begin(),
+                                  Field1End = RD1->field_end();
+       Field1 != Field1End; ++Field1) {
+    llvm::SmallPtrSet<FieldDecl *, 8>::iterator
+        I = UnmatchedFields.begin(),
+        E = UnmatchedFields.end();
+
+    for ( ; I != E; ++I) {
+      if (isLayoutCompatible(C, *Field1, *I)) {
+        bool Result = UnmatchedFields.erase(*I);
+        (void) Result;
+        assert(Result);
+        break;
+      }
+    }
+    if (I == E)
+      return false;
+  }
+
+  return UnmatchedFields.empty();
+}
+
+bool isLayoutCompatible(ASTContext &C, RecordDecl *RD1, RecordDecl *RD2) {
+  if (RD1->isUnion() != RD2->isUnion())
+    return false;
+
+  if (RD1->isUnion())
+    return isLayoutCompatibleUnion(C, RD1, RD2);
+  else
+    return isLayoutCompatibleStruct(C, RD1, RD2);
+}
+
+/// \brief Check if two types are layout-compatible in C++11 sense.
+bool isLayoutCompatible(ASTContext &C, QualType T1, QualType T2) {
+  if (T1.isNull() || T2.isNull())
+    return false;
+
+  // C++11 [basic.types] p11:
+  // If two types T1 and T2 are the same type, then T1 and T2 are
+  // layout-compatible types.
+  if (C.hasSameType(T1, T2))
+    return true;
+
+  T1 = T1.getCanonicalType().getUnqualifiedType();
+  T2 = T2.getCanonicalType().getUnqualifiedType();
+
+  const Type::TypeClass TC1 = T1->getTypeClass();
+  const Type::TypeClass TC2 = T2->getTypeClass();
+
+  if (TC1 != TC2)
+    return false;
+
+  if (TC1 == Type::Enum) {
+    return isLayoutCompatible(C,
+                              cast<EnumType>(T1)->getDecl(),
+                              cast<EnumType>(T2)->getDecl());
+  } else if (TC1 == Type::Record) {
+    if (!T1->isStandardLayoutType() || !T2->isStandardLayoutType())
+      return false;
+
+    return isLayoutCompatible(C,
+                              cast<RecordType>(T1)->getDecl(),
+                              cast<RecordType>(T2)->getDecl());
+  }
+
+  return false;
+}
+}
+
+//===--- CHECK: pointer_with_type_tag attribute: datatypes should match ----//
+
+namespace {
+/// \brief Given a type tag expression find the type tag itself.
+///
+/// \param TypeExpr Type tag expression, as it appears in user's code.
+///
+/// \param VD Declaration of an identifier that appears in a type tag.
+///
+/// \param MagicValue Type tag magic value.
+bool FindTypeTagExpr(const Expr *TypeExpr, const ASTContext &Ctx,
+                     const ValueDecl **VD, uint64_t *MagicValue) {
+  while(true) {
+    if (!TypeExpr)
+      return false;
+
+    TypeExpr = TypeExpr->IgnoreParenImpCasts()->IgnoreParenCasts();
+
+    switch (TypeExpr->getStmtClass()) {
+    case Stmt::UnaryOperatorClass: {
+      const UnaryOperator *UO = cast<UnaryOperator>(TypeExpr);
+      if (UO->getOpcode() == UO_AddrOf || UO->getOpcode() == UO_Deref) {
+        TypeExpr = UO->getSubExpr();
+        continue;
+      }
+      return false;
+    }
+
+    case Stmt::DeclRefExprClass: {
+      const DeclRefExpr *DRE = cast<DeclRefExpr>(TypeExpr);
+      *VD = DRE->getDecl();
+      return true;
+    }
+
+    case Stmt::IntegerLiteralClass: {
+      const IntegerLiteral *IL = cast<IntegerLiteral>(TypeExpr);
+      llvm::APInt MagicValueAPInt = IL->getValue();
+      if (MagicValueAPInt.getActiveBits() <= 64) {
+        *MagicValue = MagicValueAPInt.getZExtValue();
+        return true;
+      } else
+        return false;
+    }
+
+    case Stmt::BinaryConditionalOperatorClass:
+    case Stmt::ConditionalOperatorClass: {
+      const AbstractConditionalOperator *ACO =
+          cast<AbstractConditionalOperator>(TypeExpr);
+      bool Result;
+      if (ACO->getCond()->EvaluateAsBooleanCondition(Result, Ctx)) {
+        if (Result)
+          TypeExpr = ACO->getTrueExpr();
+        else
+          TypeExpr = ACO->getFalseExpr();
+        continue;
+      }
+      return false;
+    }
+
+    case Stmt::BinaryOperatorClass: {
+      const BinaryOperator *BO = cast<BinaryOperator>(TypeExpr);
+      if (BO->getOpcode() == BO_Comma) {
+        TypeExpr = BO->getRHS();
+        continue;
+      }
+      return false;
+    }
+
+    default:
+      return false;
+    }
+  }
+}
+
+/// \brief Retrieve the C type corresponding to type tag TypeExpr.
+///
+/// \param TypeExpr Expression that specifies a type tag.
+///
+/// \param MagicValues Registered magic values.
+///
+/// \param FoundWrongKind Set to true if a type tag was found, but of a wrong
+///        kind.
+///
+/// \param TypeInfo Information about the corresponding C type.
+///
+/// \returns true if the corresponding C type was found.
+bool GetMatchingCType(
+        const IdentifierInfo *ArgumentKind,
+        const Expr *TypeExpr, const ASTContext &Ctx,
+        const llvm::DenseMap<Sema::TypeTagMagicValue,
+                             Sema::TypeTagData> *MagicValues,
+        bool &FoundWrongKind,
+        Sema::TypeTagData &TypeInfo) {
+  FoundWrongKind = false;
+
+  // Variable declaration that has type_tag_for_datatype attribute.
+  const ValueDecl *VD = NULL;
+
+  uint64_t MagicValue;
+
+  if (!FindTypeTagExpr(TypeExpr, Ctx, &VD, &MagicValue))
+    return false;
+
+  if (VD) {
+    for (specific_attr_iterator<TypeTagForDatatypeAttr>
+             I = VD->specific_attr_begin<TypeTagForDatatypeAttr>(),
+             E = VD->specific_attr_end<TypeTagForDatatypeAttr>();
+         I != E; ++I) {
+      if (I->getArgumentKind() != ArgumentKind) {
+        FoundWrongKind = true;
+        return false;
+      }
+      TypeInfo.Type = I->getMatchingCType();
+      TypeInfo.LayoutCompatible = I->getLayoutCompatible();
+      TypeInfo.MustBeNull = I->getMustBeNull();
+      return true;
+    }
+    return false;
+  }
+
+  if (!MagicValues)
+    return false;
+
+  llvm::DenseMap<Sema::TypeTagMagicValue,
+                 Sema::TypeTagData>::const_iterator I =
+      MagicValues->find(std::make_pair(ArgumentKind, MagicValue));
+  if (I == MagicValues->end())
+    return false;
+
+  TypeInfo = I->second;
+  return true;
+}
+} // unnamed namespace
+
+void Sema::RegisterTypeTagForDatatype(const IdentifierInfo *ArgumentKind,
+                                      uint64_t MagicValue, QualType Type,
+                                      bool LayoutCompatible,
+                                      bool MustBeNull) {
+  if (!TypeTagForDatatypeMagicValues)
+    TypeTagForDatatypeMagicValues.reset(
+        new llvm::DenseMap<TypeTagMagicValue, TypeTagData>);
+
+  TypeTagMagicValue Magic(ArgumentKind, MagicValue);
+  (*TypeTagForDatatypeMagicValues)[Magic] =
+      TypeTagData(Type, LayoutCompatible, MustBeNull);
+}
+
+namespace {
+bool IsSameCharType(QualType T1, QualType T2) {
+  const BuiltinType *BT1 = T1->getAs<BuiltinType>();
+  if (!BT1)
+    return false;
+
+  const BuiltinType *BT2 = T2->getAs<BuiltinType>();
+  if (!BT2)
+    return false;
+
+  BuiltinType::Kind T1Kind = BT1->getKind();
+  BuiltinType::Kind T2Kind = BT2->getKind();
+
+  return (T1Kind == BuiltinType::SChar  && T2Kind == BuiltinType::Char_S) ||
+         (T1Kind == BuiltinType::UChar  && T2Kind == BuiltinType::Char_U) ||
+         (T1Kind == BuiltinType::Char_U && T2Kind == BuiltinType::UChar) ||
+         (T1Kind == BuiltinType::Char_S && T2Kind == BuiltinType::SChar);
+}
+} // unnamed namespace
+
+void Sema::CheckArgumentWithTypeTag(const ArgumentWithTypeTagAttr *Attr,
+                                    const Expr * const *ExprArgs) {
+  const IdentifierInfo *ArgumentKind = Attr->getArgumentKind();
+  bool IsPointerAttr = Attr->getIsPointer();
+
+  const Expr *TypeTagExpr = ExprArgs[Attr->getTypeTagIdx()];
+  bool FoundWrongKind;
+  TypeTagData TypeInfo;
+  if (!GetMatchingCType(ArgumentKind, TypeTagExpr, Context,
+                        TypeTagForDatatypeMagicValues.get(),
+                        FoundWrongKind, TypeInfo)) {
+    if (FoundWrongKind)
+      Diag(TypeTagExpr->getExprLoc(),
+           diag::warn_type_tag_for_datatype_wrong_kind)
+        << TypeTagExpr->getSourceRange();
+    return;
+  }
+
+  const Expr *ArgumentExpr = ExprArgs[Attr->getArgumentIdx()];
+  if (IsPointerAttr) {
+    // Skip implicit cast of pointer to `void *' (as a function argument).
+    if (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(ArgumentExpr))
+      if (ICE->getType()->isVoidPointerType())
+        ArgumentExpr = ICE->getSubExpr();
+  }
+  QualType ArgumentType = ArgumentExpr->getType();
+
+  // Passing a `void*' pointer shouldn't trigger a warning.
+  if (IsPointerAttr && ArgumentType->isVoidPointerType())
+    return;
+
+  if (TypeInfo.MustBeNull) {
+    // Type tag with matching void type requires a null pointer.
+    if (!ArgumentExpr->isNullPointerConstant(Context,
+                                             Expr::NPC_ValueDependentIsNotNull)) {
+      Diag(ArgumentExpr->getExprLoc(),
+           diag::warn_type_safety_null_pointer_required)
+          << ArgumentKind->getName()
+          << ArgumentExpr->getSourceRange()
+          << TypeTagExpr->getSourceRange();
+    }
+    return;
+  }
+
+  QualType RequiredType = TypeInfo.Type;
+  if (IsPointerAttr)
+    RequiredType = Context.getPointerType(RequiredType);
+
+  bool mismatch = false;
+  if (!TypeInfo.LayoutCompatible) {
+    mismatch = !Context.hasSameType(ArgumentType, RequiredType);
+
+    // C++11 [basic.fundamental] p1:
+    // Plain char, signed char, and unsigned char are three distinct types.
+    //
+    // But we treat plain `char' as equivalent to `signed char' or `unsigned
+    // char' depending on the current char signedness mode.
+    if (mismatch)
+      if ((IsPointerAttr && IsSameCharType(ArgumentType->getPointeeType(),
+                                           RequiredType->getPointeeType())) ||
+          (!IsPointerAttr && IsSameCharType(ArgumentType, RequiredType)))
+        mismatch = false;
+  } else
+    if (IsPointerAttr)
+      mismatch = !isLayoutCompatible(Context,
+                                     ArgumentType->getPointeeType(),
+                                     RequiredType->getPointeeType());
+    else
+      mismatch = !isLayoutCompatible(Context, ArgumentType, RequiredType);
+
+  if (mismatch)
+    Diag(ArgumentExpr->getExprLoc(), diag::warn_type_safety_type_mismatch)
+        << ArgumentType << ArgumentKind->getName()
+        << TypeInfo.LayoutCompatible << RequiredType
+        << ArgumentExpr->getSourceRange()
+        << TypeTagExpr->getSourceRange();
+}
+
diff --git a/lib/Sema/SemaDecl.cpp b/lib/Sema/SemaDecl.cpp
index 01b2f2c..75b8095 100644
--- a/lib/Sema/SemaDecl.cpp
+++ b/lib/Sema/SemaDecl.cpp
@@ -7031,6 +7031,42 @@
 Sema::FinalizeDeclaration(Decl *ThisDecl) {
   // Note that we are no longer parsing the initializer for this declaration.
   ParsingInitForAutoVars.erase(ThisDecl);
+
+  // Now we have parsed the initializer and can update the table of magic
+  // tag values.
+  if (ThisDecl && ThisDecl->hasAttr<TypeTagForDatatypeAttr>()) {
+    const VarDecl *VD = dyn_cast<VarDecl>(ThisDecl);
+    if (VD && VD->getType()->isIntegralOrEnumerationType()) {
+      for (specific_attr_iterator<TypeTagForDatatypeAttr>
+               I = ThisDecl->specific_attr_begin<TypeTagForDatatypeAttr>(),
+               E = ThisDecl->specific_attr_end<TypeTagForDatatypeAttr>();
+           I != E; ++I) {
+        const Expr *MagicValueExpr = VD->getInit();
+        if (!MagicValueExpr) {
+          continue;
+        }
+        llvm::APSInt MagicValueInt;
+        if (!MagicValueExpr->isIntegerConstantExpr(MagicValueInt, Context)) {
+          Diag(I->getRange().getBegin(),
+               diag::err_type_tag_for_datatype_not_ice)
+            << LangOpts.CPlusPlus << MagicValueExpr->getSourceRange();
+          continue;
+        }
+        if (MagicValueInt.getActiveBits() > 64) {
+          Diag(I->getRange().getBegin(),
+               diag::err_type_tag_for_datatype_too_large)
+            << LangOpts.CPlusPlus << MagicValueExpr->getSourceRange();
+          continue;
+        }
+        uint64_t MagicValue = MagicValueInt.getZExtValue();
+        RegisterTypeTagForDatatype(I->getArgumentKind(),
+                                   MagicValue,
+                                   I->getMatchingCType(),
+                                   I->getLayoutCompatible(),
+                                   I->getMustBeNull());
+      }
+    }
+  }
 }
 
 Sema::DeclGroupPtrTy
diff --git a/lib/Sema/SemaDeclAttr.cpp b/lib/Sema/SemaDeclAttr.cpp
index 29cb4f5..caa7b2f 100644
--- a/lib/Sema/SemaDeclAttr.cpp
+++ b/lib/Sema/SemaDeclAttr.cpp
@@ -221,6 +221,53 @@
   return true;
 }
 
+/// \brief Check if IdxExpr is a valid argument index for a function or
+/// instance method D.  May output an error.
+///
+/// \returns true if IdxExpr is a valid index.
+static bool checkFunctionOrMethodArgumentIndex(Sema &S, const Decl *D,
+                                               StringRef AttrName,
+                                               SourceLocation AttrLoc,
+                                               unsigned AttrArgNum,
+                                               const Expr *IdxExpr,
+                                               uint64_t &Idx)
+{
+  assert(isFunctionOrMethod(D) && hasFunctionProto(D));
+
+  // In C++ the implicit 'this' function parameter also counts.
+  // Parameters are counted from one.
+  const bool HasImplicitThisParam = isInstanceMethod(D);
+  const unsigned NumArgs = getFunctionOrMethodNumArgs(D) + HasImplicitThisParam;
+  const unsigned FirstIdx = 1;
+
+  llvm::APSInt IdxInt;
+  if (IdxExpr->isTypeDependent() || IdxExpr->isValueDependent() ||
+      !IdxExpr->isIntegerConstantExpr(IdxInt, S.Context)) {
+    S.Diag(AttrLoc, diag::err_attribute_argument_n_not_int)
+      << AttrName << AttrArgNum << IdxExpr->getSourceRange();
+    return false;
+  }
+
+  Idx = IdxInt.getLimitedValue();
+  if (Idx < FirstIdx || (!isFunctionOrMethodVariadic(D) && Idx > NumArgs)) {
+    S.Diag(AttrLoc, diag::err_attribute_argument_out_of_bounds)
+      << AttrName << AttrArgNum << IdxExpr->getSourceRange();
+    return false;
+  }
+  Idx--; // Convert to zero-based.
+  if (HasImplicitThisParam) {
+    if (Idx == 0) {
+      S.Diag(AttrLoc,
+             diag::err_attribute_invalid_implicit_this_argument)
+        << AttrName << IdxExpr->getSourceRange();
+      return false;
+    }
+    --Idx;
+  }
+
+  return true;
+}
+
 ///
 /// \brief Check if passed in Decl is a field or potentially shared global var
 /// \return true if the Decl is a field or potentially shared global variable
@@ -3696,6 +3743,79 @@
   }
 }
 
+static void handleArgumentWithTypeTagAttr(Sema &S, Decl *D,
+                                          const AttributeList &Attr) {
+  StringRef AttrName = Attr.getName()->getName();
+  if (!Attr.getParameterName()) {
+    S.Diag(Attr.getLoc(), diag::err_attribute_argument_n_not_identifier)
+      << Attr.getName() << /* arg num = */ 1;
+    return;
+  }
+
+  if (Attr.getNumArgs() != 2) {
+    S.Diag(Attr.getLoc(), diag::err_attribute_wrong_number_arguments)
+      << /* required args = */ 3;
+    return;
+  }
+
+  IdentifierInfo *ArgumentKind = Attr.getParameterName();
+
+  if (!isFunctionOrMethod(D) || !hasFunctionProto(D)) {
+    S.Diag(Attr.getLoc(), diag::err_attribute_wrong_decl_type)
+      << Attr.getName() << ExpectedFunctionOrMethod;
+    return;
+  }
+
+  uint64_t ArgumentIdx;
+  if (!checkFunctionOrMethodArgumentIndex(S, D, AttrName,
+                                          Attr.getLoc(), 2,
+                                          Attr.getArg(0), ArgumentIdx))
+    return;
+
+  uint64_t TypeTagIdx;
+  if (!checkFunctionOrMethodArgumentIndex(S, D, AttrName,
+                                          Attr.getLoc(), 3,
+                                          Attr.getArg(1), TypeTagIdx))
+    return;
+
+  bool IsPointer = (AttrName == "pointer_with_type_tag");
+  if (IsPointer) {
+    // Ensure that buffer has a pointer type.
+    QualType BufferTy = getFunctionOrMethodArgType(D, ArgumentIdx);
+    if (!BufferTy->isPointerType()) {
+      S.Diag(Attr.getLoc(), diag::err_attribute_pointers_only)
+        << AttrName;
+    }
+  }
+
+  D->addAttr(::new (S.Context) ArgumentWithTypeTagAttr(Attr.getRange(),
+                                                       S.Context,
+                                                       ArgumentKind,
+                                                       ArgumentIdx,
+                                                       TypeTagIdx,
+                                                       IsPointer));
+}
+
+static void handleTypeTagForDatatypeAttr(Sema &S, Decl *D,
+                                         const AttributeList &Attr) {
+  IdentifierInfo *PointerKind = Attr.getParameterName();
+  if (!PointerKind) {
+    S.Diag(Attr.getLoc(), diag::err_attribute_argument_n_not_identifier)
+      << "type_tag_for_datatype" << 1;
+    return;
+  }
+
+  QualType MatchingCType = S.GetTypeFromParser(Attr.getMatchingCType(), NULL);
+
+  D->addAttr(::new (S.Context) TypeTagForDatatypeAttr(
+                                  Attr.getRange(),
+                                  S.Context,
+                                  PointerKind,
+                                  MatchingCType,
+                                  Attr.getLayoutCompatible(),
+                                  Attr.getMustBeNull()));
+}
+
 //===----------------------------------------------------------------------===//
 // Checker-specific attribute handlers.
 //===----------------------------------------------------------------------===//
@@ -4326,6 +4446,14 @@
     handleAcquiredAfterAttr(S, D, Attr);
     break;
 
+  // Type safety attributes.
+  case AttributeList::AT_ArgumentWithTypeTag:
+    handleArgumentWithTypeTagAttr(S, D, Attr);
+    break;
+  case AttributeList::AT_TypeTagForDatatype:
+    handleTypeTagForDatatypeAttr(S, D, Attr);
+    break;
+
   default:
     // Ask target about the attribute.
     const TargetAttributesSema &TargetAttrs = S.getTargetAttributesSema();