diff --git a/clang/lib/AST/ASTImporter.cpp b/clang/lib/AST/ASTImporter.cpp
index 10f5a206d5b2..abf214aa1a15 100644
--- a/clang/lib/AST/ASTImporter.cpp
+++ b/clang/lib/AST/ASTImporter.cpp
@@ -332,7 +332,6 @@ static bool IsStructurallyEquivalent(StructuralEquivalenceContext &Context,
   }
   
   llvm_unreachable("Invalid template argument kind");
-  return true;
 }
 
 /// \brief Determine structural equivalence for the common part of array 
@@ -1357,8 +1356,8 @@ QualType ASTNodeImporter::VisitBuiltinType(const BuiltinType *T) {
     // wchar_t?
     return Importer.getToContext().WCharTy;
   }
-  
-  return QualType();
+
+  llvm_unreachable("Invalid BuiltinType Kind!");
 }
 
 QualType ASTNodeImporter::VisitComplexType(const ComplexType *T) {
@@ -1983,7 +1982,6 @@ ASTNodeImporter::ImportTemplateArgument(const TemplateArgument &From) {
   }
   
   llvm_unreachable("Invalid template argument kind");
-  return TemplateArgument();
 }
 
 bool ASTNodeImporter::ImportTemplateArguments(const TemplateArgument *FromArgs,
@@ -4214,7 +4212,6 @@ NestedNameSpecifier *ASTImporter::Import(NestedNameSpecifier *FromNNS) {
   }
 
   llvm_unreachable("Invalid nested name specifier kind");
-  return 0;
 }
 
 NestedNameSpecifierLoc ASTImporter::Import(NestedNameSpecifierLoc FromNNS) {
@@ -4309,7 +4306,6 @@ TemplateName ASTImporter::Import(TemplateName From) {
   }
   
   llvm_unreachable("Invalid template name kind");
-  return TemplateName();
 }
 
 SourceLocation ASTImporter::Import(SourceLocation FromLoc) {
@@ -4453,8 +4449,7 @@ DeclarationName ASTImporter::Import(DeclarationName FromName) {
     return DeclarationName::getUsingDirectiveName();
   }
 
-  // Silence bogus GCC warning
-  return DeclarationName();
+  llvm_unreachable("Invalid DeclarationName Kind!");
 }
 
 IdentifierInfo *ASTImporter::Import(const IdentifierInfo *FromId) {
diff --git a/clang/lib/AST/Decl.cpp b/clang/lib/AST/Decl.cpp
index 001620a611bf..49227e919588 100644
--- a/clang/lib/AST/Decl.cpp
+++ b/clang/lib/AST/Decl.cpp
@@ -48,8 +48,6 @@ static llvm::Optional<Visibility> getVisibilityOf(const Decl *D) {
     case VisibilityAttr::Protected:
       return ProtectedVisibility;
     }
-
-    return DefaultVisibility;
   }
 
   // If we're on Mac OS X, an 'availability' for Mac OS X attribute
@@ -1141,7 +1139,6 @@ const char *VarDecl::getStorageClassSpecifierString(StorageClass SC) {
   }
 
   llvm_unreachable("Invalid storage class");
-  return 0;
 }
 
 VarDecl *VarDecl::Create(ASTContext &C, DeclContext *DC,
diff --git a/clang/lib/AST/DeclBase.cpp b/clang/lib/AST/DeclBase.cpp
index 3763ebd2f7d7..da54a44784e2 100644
--- a/clang/lib/AST/DeclBase.cpp
+++ b/clang/lib/AST/DeclBase.cpp
@@ -529,7 +529,7 @@ unsigned Decl::getIdentifierNamespaceForKind(Kind DeclKind) {
       return 0;
   }
 
-  return 0;
+  llvm_unreachable("Invalid DeclKind!");
 }
 
 void Decl::setAttrs(const AttrVec &attrs) {
diff --git a/clang/lib/AST/DeclarationName.cpp b/clang/lib/AST/DeclarationName.cpp
index bf647ed7ac35..a5488e67ca23 100644
--- a/clang/lib/AST/DeclarationName.cpp
+++ b/clang/lib/AST/DeclarationName.cpp
@@ -125,8 +125,8 @@ int DeclarationName::compare(DeclarationName LHS, DeclarationName RHS) {
   case DeclarationName::CXXUsingDirective:
     return 0;
   }
-              
-  return 0;
+
+  llvm_unreachable("Invalid DeclarationName Kind!");
 }
 
 } // end namespace clang
@@ -189,7 +189,6 @@ DeclarationName::NameKind DeclarationName::getNameKind() const {
 
       return ObjCMultiArgSelector;
     }
-    break;
   }
 
   // Can't actually get here.
diff --git a/clang/lib/AST/DumpXML.cpp b/clang/lib/AST/DumpXML.cpp
index 9dd5a010f08c..c5e23ccc6ead 100644
--- a/clang/lib/AST/DumpXML.cpp
+++ b/clang/lib/AST/DumpXML.cpp
@@ -165,7 +165,6 @@ static StringRef getTypeKindName(Type *T) {
   }
 
   llvm_unreachable("unknown type kind!");
-  return "unknown_type";
 }
 
 struct XMLDumper : public XMLDeclVisitor<XMLDumper>,
diff --git a/clang/lib/AST/Expr.cpp b/clang/lib/AST/Expr.cpp
index 7fc070031154..a92dafb27327 100644
--- a/clang/lib/AST/Expr.cpp
+++ b/clang/lib/AST/Expr.cpp
@@ -124,7 +124,6 @@ SourceLocation Expr::getExprLoc() const {
 #include "clang/AST/StmtNodes.inc"
   }
   llvm_unreachable("unknown statement kind");
-  return SourceLocation();
 }
 
 //===----------------------------------------------------------------------===//
@@ -1213,7 +1212,6 @@ const char *CastExpr::getCastKindName() const {
   }
 
   llvm_unreachable("Unhandled cast kind!");
-  return 0;
 }
 
 Expr *CastExpr::getSubExprAsWritten() {
@@ -1255,7 +1253,6 @@ CXXBaseSpecifier **CastExpr::path_buffer() {
 #include "clang/AST/StmtNodes.inc"
   default:
     llvm_unreachable("non-cast expressions not possible here");
-    return 0;
   }
 }
 
@@ -1343,7 +1340,7 @@ const char *BinaryOperator::getOpcodeStr(Opcode Op) {
   case BO_Comma:     return ",";
   }
 
-  return "";
+  llvm_unreachable("Invalid OpCode!");
 }
 
 BinaryOperatorKind
@@ -3015,7 +3012,7 @@ SourceRange ObjCMessageExpr::getReceiverRange() const {
     return getSuperLoc();
   }
 
-  return SourceLocation();
+  llvm_unreachable("Invalid ReceiverKind!");
 }
 
 Selector ObjCMessageExpr::getSelector() const {
@@ -3064,8 +3061,8 @@ StringRef ObjCBridgedCastExpr::getBridgeKindName() const {
   case OBC_BridgeRetained:
     return "__bridge_retained";
   }
-  
-  return "__bridge";
+
+  llvm_unreachable("Invalid BridgeKind!");
 }
 
 bool ChooseExpr::isConditionTrue(const ASTContext &C) const {
diff --git a/clang/lib/AST/ExprClassification.cpp b/clang/lib/AST/ExprClassification.cpp
index 60e6f96c963b..311b80547145 100644
--- a/clang/lib/AST/ExprClassification.cpp
+++ b/clang/lib/AST/ExprClassification.cpp
@@ -47,7 +47,6 @@ static Cl::Kinds ClassifyExprValueKind(const LangOptions &Lang,
     return Cl::CL_XValue;
   }
   llvm_unreachable("Invalid value category of implicit cast.");
-  return Cl::CL_PRValue;
 }
 
 Cl Expr::ClassifyImpl(ASTContext &Ctx, SourceLocation *Loc) const {
@@ -99,7 +98,6 @@ static Cl::Kinds ClassifyInternal(ASTContext &Ctx, const Expr *E) {
 #define EXPR(Kind, Base)
 #include "clang/AST/StmtNodes.inc"
     llvm_unreachable("cannot classify a statement");
-    break;
 
     // First come the expressions that are always lvalues, unconditionally.
   case Expr::ObjCIsaExprClass:
@@ -371,7 +369,6 @@ static Cl::Kinds ClassifyInternal(ASTContext &Ctx, const Expr *E) {
   }
 
   llvm_unreachable("unhandled expression kind in classification");
-  return Cl::CL_LValue;
 }
 
 /// ClassifyDecl - Return the classification of an expression referencing the
diff --git a/clang/lib/AST/ExprConstant.cpp b/clang/lib/AST/ExprConstant.cpp
index 5d6140695902..bdedb1608ed8 100644
--- a/clang/lib/AST/ExprConstant.cpp
+++ b/clang/lib/AST/ExprConstant.cpp
@@ -3756,7 +3756,6 @@ static int EvaluateBuiltinClassifyType(const CallExpr *E) {
     return union_type_class;
   else  // FIXME: offset_type_class, method_type_class, & lang_type_class?
     llvm_unreachable("CallExpr::isBuiltinClassifyType(): unimplemented type");
-  return -1;
 }
 
 /// EvaluateBuiltinConstantPForLValue - Determine the result of
@@ -4385,7 +4384,6 @@ bool IntExprEvaluator::VisitUnaryExprOrTypeTraitExpr(
   }
 
   llvm_unreachable("unknown expr/type trait");
-  return Error(E);
 }
 
 bool IntExprEvaluator::VisitOffsetOfExpr(const OffsetOfExpr *OOE) {
@@ -4427,7 +4425,6 @@ bool IntExprEvaluator::VisitOffsetOfExpr(const OffsetOfExpr *OOE) {
 
     case OffsetOfExpr::OffsetOfNode::Identifier:
       llvm_unreachable("dependent __builtin_offsetof");
-      return Error(OOE);
 
     case OffsetOfExpr::OffsetOfNode::Base: {
       CXXBaseSpecifier *BaseSpec = ON.getBase();
@@ -4618,7 +4615,6 @@ bool IntExprEvaluator::VisitCastExpr(const CastExpr *E) {
   }
 
   llvm_unreachable("unknown cast resulting in integral value");
-  return Error(E);
 }
 
 bool IntExprEvaluator::VisitUnaryReal(const UnaryOperator *E) {
@@ -4881,8 +4877,6 @@ bool FloatExprEvaluator::VisitCastExpr(const CastExpr *E) {
     return true;
   }
   }
-
-  return Error(E);
 }
 
 //===----------------------------------------------------------------------===//
@@ -5092,7 +5086,6 @@ bool ComplexExprEvaluator::VisitCastExpr(const CastExpr *E) {
   }
 
   llvm_unreachable("unknown cast resulting in complex value");
-  return Error(E);
 }
 
 bool ComplexExprEvaluator::VisitBinaryOperator(const BinaryOperator *E) {
@@ -5928,8 +5921,7 @@ static ICEDiag CheckICE(const Expr* E, ASTContext &Ctx) {
   }
   }
 
-  // Silence a GCC warning
-  return ICEDiag(2, E->getLocStart());
+  llvm_unreachable("Invalid StmtClass!");
 }
 
 /// Evaluate an expression as a C++11 integral constant expression.
diff --git a/clang/lib/AST/ItaniumMangle.cpp b/clang/lib/AST/ItaniumMangle.cpp
index 7f2d5628a881..427be32a4607 100644
--- a/clang/lib/AST/ItaniumMangle.cpp
+++ b/clang/lib/AST/ItaniumMangle.cpp
@@ -1370,7 +1370,6 @@ void CXXNameMangler::mangleType(TemplateName TN) {
 
   case TemplateName::OverloadedTemplate:
     llvm_unreachable("can't mangle an overloaded template name as a <type>");
-    break;
 
   case TemplateName::DependentTemplate: {
     const DependentTemplateName *Dependent = TN.getAsDependentTemplateName();
@@ -1741,7 +1740,6 @@ void CXXNameMangler::mangleType(const BuiltinType *T) {
 #include "clang/AST/BuiltinTypes.def"
   case BuiltinType::Dependent:
     llvm_unreachable("mangling a placeholder type");
-    break;
   case BuiltinType::ObjCId: Out << "11objc_object"; break;
   case BuiltinType::ObjCClass: Out << "10objc_class"; break;
   case BuiltinType::ObjCSel: Out << "13objc_selector"; break;
@@ -2226,7 +2224,6 @@ recurse:
   case Expr::ParenListExprClass:
   case Expr::CXXScalarValueInitExprClass:
     llvm_unreachable("unexpected statement kind");
-    break;
 
   // FIXME: invent manglings for all these.
   case Expr::BlockExprClass:
diff --git a/clang/lib/AST/NestedNameSpecifier.cpp b/clang/lib/AST/NestedNameSpecifier.cpp
index 858cf12dc66f..c59d40a8c2bf 100644
--- a/clang/lib/AST/NestedNameSpecifier.cpp
+++ b/clang/lib/AST/NestedNameSpecifier.cpp
@@ -130,7 +130,7 @@ NestedNameSpecifier::SpecifierKind NestedNameSpecifier::getKind() const {
     return TypeSpecWithTemplate;
   }
 
-  return Global;
+  llvm_unreachable("Invalid NNS Kind!");
 }
 
 /// \brief Retrieve the namespace stored in this nested name
@@ -170,8 +170,7 @@ bool NestedNameSpecifier::isDependent() const {
     return getAsType()->isDependentType();
   }
 
-  // Necessary to suppress a GCC warning.
-  return false;
+  llvm_unreachable("Invalid NNS Kind!");
 }
 
 /// \brief Whether this nested name specifier refers to a dependent
@@ -191,9 +190,8 @@ bool NestedNameSpecifier::isInstantiationDependent() const {
   case TypeSpecWithTemplate:
     return getAsType()->isInstantiationDependentType();
   }
-  
-  // Necessary to suppress a GCC warning.
-  return false;
+
+  llvm_unreachable("Invalid NNS Kind!");
 }
 
 bool NestedNameSpecifier::containsUnexpandedParameterPack() const {
@@ -211,8 +209,7 @@ bool NestedNameSpecifier::containsUnexpandedParameterPack() const {
     return getAsType()->containsUnexpandedParameterPack();
   }
 
-  // Necessary to suppress a GCC warning.
-  return false;  
+  llvm_unreachable("Invalid NNS Kind!");
 }
 
 /// \brief Print this nested name specifier to the given output
@@ -382,8 +379,8 @@ SourceRange NestedNameSpecifierLoc::getLocalSourceRange() const {
                        LoadSourceLocation(Data, Offset + sizeof(void*)));
   }
   }
-  
-  return SourceRange();
+
+  llvm_unreachable("Invalid NNS Kind!");
 }
 
 TypeLoc NestedNameSpecifierLoc::getTypeLoc() const {
diff --git a/clang/lib/AST/Stmt.cpp b/clang/lib/AST/Stmt.cpp
index e7b87e4db679..8b2e35376bde 100644
--- a/clang/lib/AST/Stmt.cpp
+++ b/clang/lib/AST/Stmt.cpp
@@ -164,7 +164,6 @@ Stmt::child_range Stmt::children() {
 #include "clang/AST/StmtNodes.inc"
   }
   llvm_unreachable("unknown statement kind!");
-  return child_range();
 }
 
 SourceRange Stmt::getSourceRange() const {
@@ -177,7 +176,6 @@ SourceRange Stmt::getSourceRange() const {
 #include "clang/AST/StmtNodes.inc"
   }
   llvm_unreachable("unknown statement kind!");
-  return SourceRange();
 }
 
 void CompoundStmt::setStmts(ASTContext &C, Stmt **Stmts, unsigned NumStmts) {
diff --git a/clang/lib/AST/StmtProfile.cpp b/clang/lib/AST/StmtProfile.cpp
index 5a6b771b9a8e..2fb67d93a663 100644
--- a/clang/lib/AST/StmtProfile.cpp
+++ b/clang/lib/AST/StmtProfile.cpp
@@ -503,7 +503,6 @@ static Stmt::StmtClass DecodeOperatorCall(const CXXOperatorCallExpr *S,
   case OO_Conditional:
   case NUM_OVERLOADED_OPERATORS:
     llvm_unreachable("Invalid operator call kind");
-    return Stmt::ArraySubscriptExprClass;
       
   case OO_Plus:
     if (S->getNumArgs() == 1) {
diff --git a/clang/lib/AST/TemplateBase.cpp b/clang/lib/AST/TemplateBase.cpp
index 0c011a8ef090..57df8a4dceca 100644
--- a/clang/lib/AST/TemplateBase.cpp
+++ b/clang/lib/AST/TemplateBase.cpp
@@ -100,7 +100,7 @@ bool TemplateArgument::isDependent() const {
     return false;
   }
 
-  return false;
+  llvm_unreachable("Invalid TemplateArgument Kind!");
 }
 
 bool TemplateArgument::isInstantiationDependent() const {
@@ -137,8 +137,8 @@ bool TemplateArgument::isInstantiationDependent() const {
     
     return false;
   }
-  
-  return false;
+
+  llvm_unreachable("Invalid TemplateArgument Kind!");
 }
 
 bool TemplateArgument::isPackExpansion() const {
@@ -159,8 +159,8 @@ bool TemplateArgument::isPackExpansion() const {
   case Expression:
     return isa<PackExpansionExpr>(getAsExpr());
   }
-  
-  return false;
+
+  llvm_unreachable("Invalid TemplateArgument Kind!");
 }
 
 bool TemplateArgument::containsUnexpandedParameterPack() const {
@@ -278,8 +278,7 @@ bool TemplateArgument::structurallyEquals(const TemplateArgument &Other) const {
     return true;
   }
 
-  // Suppress warnings.
-  return false;
+  llvm_unreachable("Invalid TemplateArgument Kind!");
 }
 
 TemplateArgument TemplateArgument::getPackExpansionPattern() const {
@@ -302,8 +301,8 @@ TemplateArgument TemplateArgument::getPackExpansionPattern() const {
   case Template:
     return TemplateArgument();
   }
-  
-  return TemplateArgument();
+
+  llvm_unreachable("Invalid TemplateArgument Kind!");
 }
 
 void TemplateArgument::print(const PrintingPolicy &Policy, 
@@ -412,8 +411,7 @@ SourceRange TemplateArgumentLoc::getSourceRange() const {
     return SourceRange();
   }
 
-  // Silence bonus gcc warning.
-  return SourceRange();
+  llvm_unreachable("Invalid TemplateArgument Kind!");
 }
 
 TemplateArgumentLoc 
@@ -474,8 +472,8 @@ TemplateArgumentLoc::getPackExpansionPattern(SourceLocation &Ellipsis,
   case TemplateArgument::Null:
     return TemplateArgumentLoc();
   }
-  
-  return TemplateArgumentLoc();
+
+  llvm_unreachable("Invalid TemplateArgument Kind!");
 }
 
 const DiagnosticBuilder &clang::operator<<(const DiagnosticBuilder &DB,
@@ -525,8 +523,8 @@ const DiagnosticBuilder &clang::operator<<(const DiagnosticBuilder &DB,
     return DB << OS.str();
   }
   }
-  
-  return DB;
+
+  llvm_unreachable("Invalid TemplateArgument Kind!");
 }
 
 const ASTTemplateArgumentListInfo *
diff --git a/clang/lib/AST/Type.cpp b/clang/lib/AST/Type.cpp
index 7fd83b54e409..7b30c500c6e2 100644
--- a/clang/lib/AST/Type.cpp
+++ b/clang/lib/AST/Type.cpp
@@ -1364,7 +1364,6 @@ TypeWithKeyword::getTagTypeKindForTypeSpec(unsigned TypeSpec) {
   }
   
   llvm_unreachable("Type specifier is not a tag type kind.");
-  return TTK_Union;
 }
 
 ElaboratedTypeKeyword
@@ -1419,7 +1418,6 @@ TypeWithKeyword::getKeywordName(ElaboratedTypeKeyword Keyword) {
   }
 
   llvm_unreachable("Unknown elaborated type keyword.");
-  return "";
 }
 
 DependentTemplateSpecializationType::DependentTemplateSpecializationType(
@@ -1479,7 +1477,6 @@ const char *Type::getTypeClassName() const {
   }
   
   llvm_unreachable("Invalid type class.");
-  return 0;
 }
 
 const char *BuiltinType::getName(const PrintingPolicy &Policy) const {
@@ -1521,7 +1518,6 @@ const char *BuiltinType::getName(const PrintingPolicy &Policy) const {
   }
   
   llvm_unreachable("Invalid builtin type.");
-  return 0;
 }
 
 QualType QualType::getNonLValueExprType(ASTContext &Context) const {
@@ -1544,7 +1540,6 @@ StringRef FunctionType::getNameForCallConv(CallingConv CC) {
   switch (CC) {
   case CC_Default: 
     llvm_unreachable("no name for default cc");
-    return "";
 
   case CC_C: return "cdecl";
   case CC_X86StdCall: return "stdcall";
@@ -1556,7 +1551,6 @@ StringRef FunctionType::getNameForCallConv(CallingConv CC) {
   }
 
   llvm_unreachable("Invalid calling convention.");
-  return "";
 }
 
 FunctionProtoType::FunctionProtoType(QualType result, const QualType *args,
diff --git a/clang/lib/AST/TypeLoc.cpp b/clang/lib/AST/TypeLoc.cpp
index 97b0b501aa86..ed7faa9429ce 100644
--- a/clang/lib/AST/TypeLoc.cpp
+++ b/clang/lib/AST/TypeLoc.cpp
@@ -196,57 +196,54 @@ SourceRange TypeOfExprTypeLoc::getLocalSourceRange() const {
 TypeSpecifierType BuiltinTypeLoc::getWrittenTypeSpec() const {
   if (needsExtraLocalData())
     return static_cast<TypeSpecifierType>(getWrittenBuiltinSpecs().Type);
-  else {
-    switch (getTypePtr()->getKind()) {
-    case BuiltinType::Void:
-      return TST_void;
-    case BuiltinType::Bool:
-      return TST_bool;
-    case BuiltinType::Char_U:
-    case BuiltinType::Char_S:
-      return TST_char;
-    case BuiltinType::Char16:
-      return TST_char16;
-    case BuiltinType::Char32:
-      return TST_char32;
-    case BuiltinType::WChar_S:
-    case BuiltinType::WChar_U:
-      return TST_wchar;
-
-    case BuiltinType::UChar:
-    case BuiltinType::UShort:
-    case BuiltinType::UInt:
-    case BuiltinType::ULong:
-    case BuiltinType::ULongLong:
-    case BuiltinType::UInt128:
-    case BuiltinType::SChar:
-    case BuiltinType::Short:
-    case BuiltinType::Int:
-    case BuiltinType::Long:
-    case BuiltinType::LongLong:
-    case BuiltinType::Int128:
-    case BuiltinType::Half:
-    case BuiltinType::Float:
-    case BuiltinType::Double:
-    case BuiltinType::LongDouble:
-      llvm_unreachable("Builtin type needs extra local data!");
-      // Fall through, if the impossible happens.
-        
-    case BuiltinType::NullPtr:
-    case BuiltinType::Overload:
-    case BuiltinType::Dependent:
-    case BuiltinType::BoundMember:
-    case BuiltinType::UnknownAny:
-    case BuiltinType::ARCUnbridgedCast:
-    case BuiltinType::PseudoObject:
-    case BuiltinType::ObjCId:
-    case BuiltinType::ObjCClass:
-    case BuiltinType::ObjCSel:
-      return TST_unspecified;
-    }
+  switch (getTypePtr()->getKind()) {
+  case BuiltinType::Void:
+    return TST_void;
+  case BuiltinType::Bool:
+    return TST_bool;
+  case BuiltinType::Char_U:
+  case BuiltinType::Char_S:
+    return TST_char;
+  case BuiltinType::Char16:
+    return TST_char16;
+  case BuiltinType::Char32:
+    return TST_char32;
+  case BuiltinType::WChar_S:
+  case BuiltinType::WChar_U:
+    return TST_wchar;
+  case BuiltinType::UChar:
+  case BuiltinType::UShort:
+  case BuiltinType::UInt:
+  case BuiltinType::ULong:
+  case BuiltinType::ULongLong:
+  case BuiltinType::UInt128:
+  case BuiltinType::SChar:
+  case BuiltinType::Short:
+  case BuiltinType::Int:
+  case BuiltinType::Long:
+  case BuiltinType::LongLong:
+  case BuiltinType::Int128:
+  case BuiltinType::Half:
+  case BuiltinType::Float:
+  case BuiltinType::Double:
+  case BuiltinType::LongDouble:
+    llvm_unreachable("Builtin type needs extra local data!");
+    // Fall through, if the impossible happens.
+      
+  case BuiltinType::NullPtr:
+  case BuiltinType::Overload:
+  case BuiltinType::Dependent:
+  case BuiltinType::BoundMember:
+  case BuiltinType::UnknownAny:
+  case BuiltinType::ARCUnbridgedCast:
+  case BuiltinType::PseudoObject:
+  case BuiltinType::ObjCId:
+  case BuiltinType::ObjCClass:
+  case BuiltinType::ObjCSel:
+    return TST_unspecified;
   }
-  
-  return TST_unspecified;
+
+  llvm_unreachable("Invalid BuiltinType Kind!");
 }
 
 TypeLoc TypeLoc::IgnoreParensImpl(TypeLoc TL) {
diff --git a/clang/lib/AST/TypePrinter.cpp b/clang/lib/AST/TypePrinter.cpp
index 5dd42721d31d..b6d71108bd5d 100644
--- a/clang/lib/AST/TypePrinter.cpp
+++ b/clang/lib/AST/TypePrinter.cpp
@@ -934,7 +934,7 @@ void TypePrinter::printAttributed(const AttributedType *T,
   case AttributedType::attr_objc_ownership:
     S += "objc_ownership(";
     switch (T->getEquivalentType().getObjCLifetime()) {
-    case Qualifiers::OCL_None: llvm_unreachable("no ownership!"); break;
+    case Qualifiers::OCL_None: llvm_unreachable("no ownership!");
     case Qualifiers::OCL_ExplicitNone: S += "none"; break;
     case Qualifiers::OCL_Strong: S += "strong"; break;
     case Qualifiers::OCL_Weak: S += "weak"; break;
diff --git a/clang/lib/Analysis/CFG.cpp b/clang/lib/Analysis/CFG.cpp
index 4ccbf595a740..7b84710b5944 100644
--- a/clang/lib/Analysis/CFG.cpp
+++ b/clang/lib/Analysis/CFG.cpp
@@ -3090,7 +3090,6 @@ CFGImplicitDtor::getDestructorDecl(ASTContext &astContext) const {
       return 0;
   }
   llvm_unreachable("getKind() returned bogus value");
-  return 0;
 }
 
 bool CFGImplicitDtor::isNoReturn(ASTContext &astContext) const {
diff --git a/clang/lib/Analysis/CocoaConventions.cpp b/clang/lib/Analysis/CocoaConventions.cpp
index 0c1531da148c..ee8a6efb3587 100644
--- a/clang/lib/Analysis/CocoaConventions.cpp
+++ b/clang/lib/Analysis/CocoaConventions.cpp
@@ -58,7 +58,6 @@ cocoa::NamingConvention cocoa::deriveNamingConvention(Selector S,
     return CreateRule;
   }
   llvm_unreachable("unexpected naming convention");
-  return NoConvention;
 }
 
 bool cocoa::isRefType(QualType RetTy, StringRef Prefix,
@@ -176,6 +175,4 @@ bool coreFoundation::followsCreateRule(const FunctionDecl *fn) {
     // If we matched a lowercase character, it isn't the end of the
     // word.  Keep scanning.
   }
-  
-  return false;
 }
diff --git a/clang/lib/Analysis/FormatString.cpp b/clang/lib/Analysis/FormatString.cpp
index dcab03c3c090..207f77301b4b 100644
--- a/clang/lib/Analysis/FormatString.cpp
+++ b/clang/lib/Analysis/FormatString.cpp
@@ -340,9 +340,7 @@ bool ArgTypeResult::matchesType(ASTContext &C, QualType argTy) const {
       return argTy->getAs<ObjCObjectPointerType>() != NULL;
   }
 
-  // FIXME: Should be unreachable, but Clang is currently emitting
-  // a warning.
-  return false;
+  llvm_unreachable("Invalid ArgTypeResult Kind!");
 }
 
 QualType ArgTypeResult::getRepresentativeType(ASTContext &C) const {
@@ -369,9 +367,7 @@ QualType ArgTypeResult::getRepresentativeType(ASTContext &C) const {
     }
   }
 
-  // FIXME: Should be unreachable, but Clang is currently emitting
-  // a warning.
-  return QualType();
+  llvm_unreachable("Invalid ArgTypeResult Kind!");
 }
 
 std::string ArgTypeResult::getRepresentativeTypeName(ASTContext &C) const {
@@ -577,5 +573,5 @@ bool FormatSpecifier::hasValidLengthModifier() const {
           return false;
       }
   }
-  return false;
+  llvm_unreachable("Invalid LengthModifier Kind!");
 }
diff --git a/clang/lib/Analysis/ScanfFormatString.cpp b/clang/lib/Analysis/ScanfFormatString.cpp
index d5a44cb8e0b7..38afd615c192 100644
--- a/clang/lib/Analysis/ScanfFormatString.cpp
+++ b/clang/lib/Analysis/ScanfFormatString.cpp
@@ -462,7 +462,7 @@ bool ScanfArgTypeResult::matchesType(ASTContext& C, QualType argTy) const {
     }
   }
 
-  return false; // Unreachable, but we still get a warning.
+  llvm_unreachable("Invalid ScanfArgTypeResult Kind!");
 }
 
 QualType ScanfArgTypeResult::getRepresentativeType(ASTContext &C) const {
@@ -479,7 +479,7 @@ QualType ScanfArgTypeResult::getRepresentativeType(ASTContext &C) const {
       return C.getPointerType(A.getRepresentativeType(C));
   }
 
-  return QualType(); // Not reachable.
+  llvm_unreachable("Invalid ScanfArgTypeResult Kind!");
 }
 
 std::string ScanfArgTypeResult::getRepresentativeTypeName(ASTContext& C) const {
diff --git a/clang/lib/CodeGen/CGBuiltin.cpp b/clang/lib/CodeGen/CGBuiltin.cpp
index c2abae8a6aee..a3e21dcab68c 100644
--- a/clang/lib/CodeGen/CGBuiltin.cpp
+++ b/clang/lib/CodeGen/CGBuiltin.cpp
@@ -4577,5 +4577,4 @@ Value *CodeGenFunction::EmitPPCBuiltinExpr(unsigned BuiltinID,
     return Builder.CreateCall(F, Ops, "");
   }
   }
-  return 0;
 }
diff --git a/clang/lib/CodeGen/CGCleanup.cpp b/clang/lib/CodeGen/CGCleanup.cpp
index 308409dbb63f..f1f17afdb451 100644
--- a/clang/lib/CodeGen/CGCleanup.cpp
+++ b/clang/lib/CodeGen/CGCleanup.cpp
@@ -84,7 +84,6 @@ RValue DominatingValue<RValue>::saved_type::restore(CodeGenFunction &CGF) {
   }
 
   llvm_unreachable("bad saved r-value kind");
-  return RValue();
 }
 
 /// Push an entry of the given size onto this protected-scope stack.
diff --git a/clang/lib/CodeGen/CGDebugInfo.cpp b/clang/lib/CodeGen/CGDebugInfo.cpp
index ba89d3756e89..3d0e8cc29b96 100644
--- a/clang/lib/CodeGen/CGDebugInfo.cpp
+++ b/clang/lib/CodeGen/CGDebugInfo.cpp
@@ -1565,8 +1565,6 @@ static QualType UnwrapTypeForDebugInfo(QualType T) {
     if (T == LastT)
       return T;
   } while (true);
-  
-  return T;
 }
 
 /// getType - Get the type from the cache or return null type if it doesn't exist.
@@ -1677,7 +1675,6 @@ llvm::DIType CGDebugInfo::CreateTypeNode(QualType Ty, llvm::DIFile Unit) {
   case Type::UnaryTransform:
   case Type::Auto:
     llvm_unreachable("type should have been unwrapped!");
-    return llvm::DIType();      
   }
   
   assert(Diag && "Fall through without a diagnostic?");
diff --git a/clang/lib/CodeGen/CGException.cpp b/clang/lib/CodeGen/CGException.cpp
index 7600c48bdbcc..e1eefc0bc3b2 100644
--- a/clang/lib/CodeGen/CGException.cpp
+++ b/clang/lib/CodeGen/CGException.cpp
@@ -636,8 +636,7 @@ static bool isNonEHScope(const EHScope &S) {
     return false;
   }
 
-  // Suppress warning.
-  return false;
+  llvm_unreachable("Invalid EHScope Kind!");
 }
 
 llvm::BasicBlock *CodeGenFunction::getInvokeDestImpl() {
diff --git a/clang/lib/CodeGen/CGExpr.cpp b/clang/lib/CodeGen/CGExpr.cpp
index 43ab116dae74..97a2f0546668 100644
--- a/clang/lib/CodeGen/CGExpr.cpp
+++ b/clang/lib/CodeGen/CGExpr.cpp
@@ -1427,10 +1427,6 @@ LValue CodeGenFunction::EmitDeclRefLValue(const DeclRefExpr *E) {
     return EmitFunctionDeclLValue(*this, E, fn);
 
   llvm_unreachable("Unhandled DeclRefExpr");
-  
-  // an invalid LValue, but the assert will
-  // ensure that this point is never reached.
-  return LValue();
 }
 
 LValue CodeGenFunction::EmitBlockDeclRefLValue(const BlockDeclRefExpr *E) {
diff --git a/clang/lib/CodeGen/CGExprAgg.cpp b/clang/lib/CodeGen/CGExprAgg.cpp
index fbcdcc0d3d75..780ff26f2386 100644
--- a/clang/lib/CodeGen/CGExprAgg.cpp
+++ b/clang/lib/CodeGen/CGExprAgg.cpp
@@ -349,7 +349,6 @@ void AggExprEmitter::VisitCastExpr(CastExpr *E) {
       
   case CK_LValueBitCast:
     llvm_unreachable("should not be emitting lvalue bitcast as rvalue");
-    break;
 
   case CK_Dependent:
   case CK_BitCast:
diff --git a/clang/lib/CodeGen/CGExprComplex.cpp b/clang/lib/CodeGen/CGExprComplex.cpp
index b4b1b1d5f94a..53f7d65ef1b2 100644
--- a/clang/lib/CodeGen/CGExprComplex.cpp
+++ b/clang/lib/CodeGen/CGExprComplex.cpp
@@ -817,7 +817,6 @@ EmitComplexCompoundAssignmentLValue(const CompoundAssignOperator *E) {
 
   default:
     llvm_unreachable("unexpected complex compound assignment");
-    Op = 0;
   }
 
   ComplexPairTy Val; // ignored
diff --git a/clang/lib/CodeGen/CGExprScalar.cpp b/clang/lib/CodeGen/CGExprScalar.cpp
index faa90872e7e4..e1342d3ce5d4 100644
--- a/clang/lib/CodeGen/CGExprScalar.cpp
+++ b/clang/lib/CodeGen/CGExprScalar.cpp
@@ -1167,7 +1167,6 @@ Value *ScalarExprEmitter::VisitCastExpr(CastExpr *CE) {
   case CK_ConstructorConversion:
   case CK_ToUnion:
     llvm_unreachable("scalar cast to non-scalar value");
-    break;
 
   case CK_LValueToRValue:
     assert(CGF.getContext().hasSameUnqualifiedType(E->getType(), DestTy));
@@ -1247,7 +1246,6 @@ Value *ScalarExprEmitter::VisitCastExpr(CastExpr *CE) {
   }
 
   llvm_unreachable("unknown scalar cast");
-  return 0;
 }
 
 Value *ScalarExprEmitter::VisitStmtExpr(const StmtExpr *E) {
@@ -1272,10 +1270,8 @@ EmitAddConsiderOverflowBehavior(const UnaryOperator *E,
   switch (CGF.getContext().getLangOptions().getSignedOverflowBehavior()) {
   case LangOptions::SOB_Undefined:
     return Builder.CreateNSWAdd(InVal, NextVal, IsInc ? "inc" : "dec");
-    break;
   case LangOptions::SOB_Defined:
     return Builder.CreateAdd(InVal, NextVal, IsInc ? "inc" : "dec");
-    break;
   case LangOptions::SOB_Trapping:
     BinOpInfo BinOp;
     BinOp.LHS = InVal;
@@ -1875,7 +1871,6 @@ Value *ScalarExprEmitter::EmitOverflowCheckedBinOp(const BinOpInfo &Ops) {
     break;
   default:
     llvm_unreachable("Unsupported operation for overflow detection");
-    IID = 0;
   }
   OpID <<= 1;
   OpID |= 1;
@@ -2175,36 +2170,28 @@ static llvm::Intrinsic::ID GetIntrinsic(IntrinsicType IT,
   case BuiltinType::UChar:
     return (IT == VCMPEQ) ? llvm::Intrinsic::ppc_altivec_vcmpequb_p :
                             llvm::Intrinsic::ppc_altivec_vcmpgtub_p;
-    break;
   case BuiltinType::Char_S:
   case BuiltinType::SChar:
     return (IT == VCMPEQ) ? llvm::Intrinsic::ppc_altivec_vcmpequb_p :
                             llvm::Intrinsic::ppc_altivec_vcmpgtsb_p;
-    break;
   case BuiltinType::UShort:
     return (IT == VCMPEQ) ? llvm::Intrinsic::ppc_altivec_vcmpequh_p :
                             llvm::Intrinsic::ppc_altivec_vcmpgtuh_p;
-    break;
   case BuiltinType::Short:
     return (IT == VCMPEQ) ? llvm::Intrinsic::ppc_altivec_vcmpequh_p :
                             llvm::Intrinsic::ppc_altivec_vcmpgtsh_p;
-    break;
   case BuiltinType::UInt:
   case BuiltinType::ULong:
     return (IT == VCMPEQ) ? llvm::Intrinsic::ppc_altivec_vcmpequw_p :
                             llvm::Intrinsic::ppc_altivec_vcmpgtuw_p;
-    break;
   case BuiltinType::Int:
   case BuiltinType::Long:
     return (IT == VCMPEQ) ? llvm::Intrinsic::ppc_altivec_vcmpequw_p :
                             llvm::Intrinsic::ppc_altivec_vcmpgtsw_p;
-    break;
   case BuiltinType::Float:
     return (IT == VCMPEQ) ? llvm::Intrinsic::ppc_altivec_vcmpeqfp_p :
                             llvm::Intrinsic::ppc_altivec_vcmpgtfp_p;
-    break;
   }
-  return llvm::Intrinsic::not_intrinsic;
 }
 
 Value *ScalarExprEmitter::EmitCompare(const BinaryOperator *E,unsigned UICmpOpc,
diff --git a/clang/lib/CodeGen/CGObjC.cpp b/clang/lib/CodeGen/CGObjC.cpp
index 6bf32a50f420..581d463b8734 100644
--- a/clang/lib/CodeGen/CGObjC.cpp
+++ b/clang/lib/CodeGen/CGObjC.cpp
@@ -2086,7 +2086,6 @@ static TryEmitResult tryEmitARCRetainLoadOfScalar(CodeGenFunction &CGF,
   }
 
   llvm_unreachable("impossible lifetime!");
-  return TryEmitResult();
 }
 
 static TryEmitResult tryEmitARCRetainLoadOfScalar(CodeGenFunction &CGF,
diff --git a/clang/lib/CodeGen/CGObjCMac.cpp b/clang/lib/CodeGen/CGObjCMac.cpp
index 159e927508a4..ecf6181b1cec 100644
--- a/clang/lib/CodeGen/CGObjCMac.cpp
+++ b/clang/lib/CodeGen/CGObjCMac.cpp
@@ -1516,7 +1516,6 @@ llvm::Constant *CGObjCMac::GetEHType(QualType T) {
     return CGM.GetAddrOfRTTIDescriptor(T,  /*ForEH=*/true);
   
   llvm_unreachable("asking for catch type for ObjC type in fragile runtime");
-  return 0;
 }
 
 /// Generate a constant CFString object.
diff --git a/clang/lib/CodeGen/CGRTTI.cpp b/clang/lib/CodeGen/CGRTTI.cpp
index d9790d0b9e75..120e711e8407 100644
--- a/clang/lib/CodeGen/CGRTTI.cpp
+++ b/clang/lib/CodeGen/CGRTTI.cpp
@@ -207,9 +207,8 @@ static bool TypeInfoIsInStandardLibrary(const BuiltinType *Ty) {
     case BuiltinType::ObjCSel:
       llvm_unreachable("FIXME: Objective-C types are unsupported!");
   }
-  
-  // Silent gcc.
-  return false;
+
+  llvm_unreachable("Invalid BuiltinType Kind!");
 }
 
 static bool TypeInfoIsInStandardLibrary(const PointerType *PointerTy) {
@@ -345,7 +344,7 @@ getTypeInfoLinkage(CodeGenModule &CGM, QualType Ty) {
     return llvm::GlobalValue::LinkOnceODRLinkage;
   }
 
-  return llvm::GlobalValue::LinkOnceODRLinkage;
+  llvm_unreachable("Invalid linkage!");
 }
 
 // CanUseSingleInheritance - Return whether the given record decl has a "single, 
diff --git a/clang/lib/CodeGen/CodeGenModule.cpp b/clang/lib/CodeGen/CodeGenModule.cpp
index e7c0b4c066ff..c54b904abcb0 100644
--- a/clang/lib/CodeGen/CodeGenModule.cpp
+++ b/clang/lib/CodeGen/CodeGenModule.cpp
@@ -57,7 +57,6 @@ static CGCXXABI &createCXXABI(CodeGenModule &CGM) {
   }
 
   llvm_unreachable("invalid C++ ABI kind");
-  return *CreateItaniumCXXABI(CGM);
 }
 
 
@@ -1340,9 +1339,8 @@ CodeGenModule::getVTableLinkage(const CXXRecordDecl *RD) {
   case TSK_ExplicitInstantiationDefinition:
       return llvm::GlobalVariable::WeakODRLinkage;
   }
-  
-  // Silence GCC warning.
-  return llvm::GlobalVariable::LinkOnceODRLinkage;
+
+  llvm_unreachable("Invalid TemplateSpecializationKind!");
 }
 
 CharUnits CodeGenModule::GetTargetTypeStoreSize(llvm::Type *Ty) const {
diff --git a/clang/lib/CodeGen/CodeGenModule.h b/clang/lib/CodeGen/CodeGenModule.h
index d94d10afc159..ca096c1019f8 100644
--- a/clang/lib/CodeGen/CodeGenModule.h
+++ b/clang/lib/CodeGen/CodeGenModule.h
@@ -469,7 +469,6 @@ public:
     case ProtectedVisibility: return llvm::GlobalValue::ProtectedVisibility;
     }
     llvm_unreachable("unknown visibility!");
-    return llvm::GlobalValue::DefaultVisibility;
   }
 
   llvm::Constant *GetAddrOfGlobal(GlobalDecl GD) {
diff --git a/clang/lib/CodeGen/CodeGenTypes.cpp b/clang/lib/CodeGen/CodeGenTypes.cpp
index 578695009bba..b5546e2f18e5 100644
--- a/clang/lib/CodeGen/CodeGenTypes.cpp
+++ b/clang/lib/CodeGen/CodeGenTypes.cpp
@@ -305,7 +305,6 @@ llvm::Type *CodeGenTypes::ConvertType(QualType T) {
 #define NON_CANONICAL_UNLESS_DEPENDENT_TYPE(Class, Base) case Type::Class:
 #include "clang/AST/TypeNodes.def"
     llvm_unreachable("Non-canonical or dependent types aren't possible.");
-    break;
 
   case Type::Builtin: {
     switch (cast<BuiltinType>(Ty)->getKind()) {
@@ -374,7 +373,6 @@ llvm::Type *CodeGenTypes::ConvertType(QualType T) {
     case BuiltinType::Id:
 #include "clang/AST/BuiltinTypes.def"
       llvm_unreachable("Unexpected placeholder builtin type!");
-      break;
     }
     break;
   }
diff --git a/clang/lib/CodeGen/TargetInfo.cpp b/clang/lib/CodeGen/TargetInfo.cpp
index e9f88b7aaf16..88bf8fe12292 100644
--- a/clang/lib/CodeGen/TargetInfo.cpp
+++ b/clang/lib/CodeGen/TargetInfo.cpp
@@ -2847,7 +2847,6 @@ void PTXABIInfo::computeInfo(CGFunctionInfo &FI) const {
 llvm::Value *PTXABIInfo::EmitVAArg(llvm::Value *VAListAddr, QualType Ty,
                                    CodeGenFunction &CFG) const {
   llvm_unreachable("PTX does not support varargs");
-  return 0;
 }
 
 void PTXTargetCodeGenInfo::SetTargetAttributes(const Decl *D,
diff --git a/clang/lib/Frontend/CompilerInvocation.cpp b/clang/lib/Frontend/CompilerInvocation.cpp
index a64b8cf88302..671cfc5a05f7 100644
--- a/clang/lib/Frontend/CompilerInvocation.cpp
+++ b/clang/lib/Frontend/CompilerInvocation.cpp
@@ -395,7 +395,6 @@ static const char *getInputKindName(InputKind Kind) {
   }
 
   llvm_unreachable("Unexpected language kind!");
-  return 0;
 }
 
 static const char *getActionName(frontend::ActionKind Kind) {
@@ -433,7 +432,6 @@ static const char *getActionName(frontend::ActionKind Kind) {
   }
 
   llvm_unreachable("Unexpected language kind!");
-  return 0;
 }
 
 static void FileSystemOptsToArgs(const FileSystemOptions &Opts,
diff --git a/clang/lib/Index/ASTLocation.cpp b/clang/lib/Index/ASTLocation.cpp
index a8537b1a1a05..2d5dc88f8466 100644
--- a/clang/lib/Index/ASTLocation.cpp
+++ b/clang/lib/Index/ASTLocation.cpp
@@ -50,8 +50,8 @@ Decl *ASTLocation::getReferencedDecl() {
   case N_Stmt:
     return getDeclFromExpr(Stm);
   }
-  
-  return 0;
+
+  llvm_unreachable("Invalid ASTLocation Kind!");
 }
 
 SourceRange ASTLocation::getSourceRange() const {
@@ -68,8 +68,8 @@ SourceRange ASTLocation::getSourceRange() const {
   case N_Type:
     return AsTypeLoc().getLocalSourceRange();
   }
-  
-  return SourceRange();
+
+  llvm_unreachable("Invalid ASTLocation Kind!");
 }
 
 void ASTLocation::print(raw_ostream &OS) const {
diff --git a/clang/lib/Parse/ParseExprCXX.cpp b/clang/lib/Parse/ParseExprCXX.cpp
index 4bd4c6f7eb21..8046f6b88c7a 100644
--- a/clang/lib/Parse/ParseExprCXX.cpp
+++ b/clang/lib/Parse/ParseExprCXX.cpp
@@ -2464,7 +2464,7 @@ ExprResult Parser::ParseArrayTypeTrait() {
                                        T.getCloseLocation());
   }
   }
-  return ExprError();
+  llvm_unreachable("Invalid ArrayTypeTrait!");
 }
 
 /// ParseExpressionTrait - Parse built-in expression-trait
diff --git a/clang/lib/Sema/SemaDeclCXX.cpp b/clang/lib/Sema/SemaDeclCXX.cpp
index 9693c18979e4..fc16b9bbaf54 100644
--- a/clang/lib/Sema/SemaDeclCXX.cpp
+++ b/clang/lib/Sema/SemaDeclCXX.cpp
@@ -2673,8 +2673,8 @@ struct BaseAndFieldInfo {
     case IIK_Default:
       return false;
     }
-    
-    return false;
+
+    llvm_unreachable("Invalid ImplicitInitializerKind!");
   }
 };
 }
diff --git a/clang/lib/Sema/SemaLookup.cpp b/clang/lib/Sema/SemaLookup.cpp
index 445909817909..dd50cd2a5a25 100644
--- a/clang/lib/Sema/SemaLookup.cpp
+++ b/clang/lib/Sema/SemaLookup.cpp
@@ -1732,7 +1732,6 @@ bool Sema::DiagnoseAmbiguousLookup(LookupResult &Result) {
   }
 
   llvm_unreachable("unknown ambiguity kind");
-  return true;
 }
 
 namespace {
diff --git a/clang/lib/Sema/SemaTemplateDeduction.cpp b/clang/lib/Sema/SemaTemplateDeduction.cpp
index 137556fa214f..0d74f24f4d75 100644
--- a/clang/lib/Sema/SemaTemplateDeduction.cpp
+++ b/clang/lib/Sema/SemaTemplateDeduction.cpp
@@ -278,7 +278,7 @@ checkDeducedTemplateArguments(ASTContext &Context,
     return X;
   }
 
-  return DeducedTemplateArgument();
+  llvm_unreachable("Invalid TemplateArgument Kind!");
 }
 
 /// \brief Deduce the value of the given non-type template parameter
@@ -1529,7 +1529,7 @@ DeduceTemplateArgumentsByTypeMatch(Sema &S,
       return Sema::TDK_Success;
   }
 
-  return Sema::TDK_Success;
+  llvm_unreachable("Invalid Type Class!");
 }
 
 static Sema::TemplateDeductionResult
@@ -1570,7 +1570,6 @@ DeduceTemplateArguments(Sema &S,
 
   case TemplateArgument::TemplateExpansion:
     llvm_unreachable("caller should handle pack expansions");
-    break;
 
   case TemplateArgument::Declaration:
     if (Arg.getKind() == TemplateArgument::Declaration &&
@@ -1630,7 +1629,7 @@ DeduceTemplateArguments(Sema &S,
     llvm_unreachable("Argument packs should be expanded by the caller!");
   }
 
-  return Sema::TDK_Success;
+  llvm_unreachable("Invalid TemplateArgument Kind!");
 }
 
 /// \brief Determine whether there is a template argument to be used for
@@ -1880,7 +1879,7 @@ static bool isSameTemplateArg(ASTContext &Context,
       return true;
   }
 
-  return false;
+  llvm_unreachable("Invalid TemplateArgument Kind!");
 }
 
 /// \brief Allocate a TemplateArgumentLoc where all locations have
@@ -1905,7 +1904,6 @@ getTrivialTemplateArgumentLoc(Sema &S,
   switch (Arg.getKind()) {
   case TemplateArgument::Null:
     llvm_unreachable("Can't get a NULL template argument here");
-    break;
 
   case TemplateArgument::Type:
     return TemplateArgumentLoc(Arg,
@@ -1950,7 +1948,7 @@ getTrivialTemplateArgumentLoc(Sema &S,
     return TemplateArgumentLoc(Arg, TemplateArgumentLocInfo());
   }
 
-  return TemplateArgumentLoc();
+  llvm_unreachable("Invalid TemplateArgument Kind!");
 }
 
 
diff --git a/clang/lib/Sema/SemaTemplateVariadic.cpp b/clang/lib/Sema/SemaTemplateVariadic.cpp
index 44242f1c137c..3dc60f8c7ae9 100644
--- a/clang/lib/Sema/SemaTemplateVariadic.cpp
+++ b/clang/lib/Sema/SemaTemplateVariadic.cpp
@@ -388,7 +388,6 @@ Sema::ActOnPackExpansion(const ParsedTemplateArgument &Arg,
     return Arg.getTemplatePackExpansion(EllipsisLoc);
   }
   llvm_unreachable("Unhandled template argument kind?");
-  return ParsedTemplateArgument();
 }
 
 TypeResult Sema::ActOnPackExpansion(ParsedType Type, 
@@ -632,7 +631,6 @@ unsigned Sema::getNumArgumentsInExpansion(QualType T,
   }
   
   llvm_unreachable("No unexpanded parameter packs in type expansion.");
-  return 0;
 }
 
 bool Sema::containsUnexpandedParameterPacks(Declarator &D) {
@@ -695,7 +693,6 @@ bool Sema::containsUnexpandedParameterPacks(Declarator &D) {
       // declarator-id (conceptually), so the parser should not invoke this
       // routine at this time.
       llvm_unreachable("Could not have seen this kind of declarator chunk");
-      break;
         
     case DeclaratorChunk::MemberPointer:
       if (Chunk.Mem.Scope().getScopeRep() &&
diff --git a/clang/lib/Sema/SemaType.cpp b/clang/lib/Sema/SemaType.cpp
index 006cf973d87c..e1bd81395525 100644
--- a/clang/lib/Sema/SemaType.cpp
+++ b/clang/lib/Sema/SemaType.cpp
@@ -1794,10 +1794,8 @@ static QualType GetDeclSpecTypeForDeclarator(TypeProcessingState &state,
     switch (D.getContext()) {
     case Declarator::KNRTypeListContext:
       llvm_unreachable("K&R type lists aren't allowed in C++");
-      break;
     case Declarator::LambdaExprContext:
       llvm_unreachable("Can't specify a type specifier in lambda grammar");
-      break;
     case Declarator::ObjCParameterContext:
     case Declarator::ObjCResultContext:
     case Declarator::PrototypeContext:
@@ -2327,7 +2325,6 @@ static TypeSourceInfo *GetFullTypeForDeclarator(TypeProcessingState &state,
         case NestedNameSpecifier::NamespaceAlias:
         case NestedNameSpecifier::Global:
           llvm_unreachable("Nested-name-specifier must name a type");
-          break;
 
         case NestedNameSpecifier::TypeSpec:
         case NestedNameSpecifier::TypeSpecWithTemplate:
@@ -2659,7 +2656,7 @@ static void transferARCOwnershipToDeclaratorChunk(TypeProcessingState &state,
 
   const char *attrStr = 0;
   switch (ownership) {
-  case Qualifiers::OCL_None: llvm_unreachable("no ownership!"); break;
+  case Qualifiers::OCL_None: llvm_unreachable("no ownership!");
   case Qualifiers::OCL_ExplicitNone: attrStr = "none"; break;
   case Qualifiers::OCL_Strong: attrStr = "strong"; break;
   case Qualifiers::OCL_Weak: attrStr = "weak"; break;
@@ -2780,7 +2777,6 @@ static AttributeList::Kind getAttrListKind(AttributedType::Kind kind) {
     return AttributeList::AT_pcs;
   }
   llvm_unreachable("unexpected attribute kind!");
-  return AttributeList::Kind();
 }
 
 static void fillAttributedTypeLoc(AttributedTypeLoc TL,
@@ -3055,7 +3051,6 @@ namespace {
       case NestedNameSpecifier::NamespaceAlias:
       case NestedNameSpecifier::Global:
         llvm_unreachable("Nested-name-specifier must name a type");
-        break;
       }
 
       // Finally fill in MemberPointerLocInfo fields.
@@ -3572,7 +3567,6 @@ namespace {
       }
 
       llvm_unreachable("unknown wrapping kind");
-      return QualType();
     }
   };
 }
diff --git a/clang/lib/StaticAnalyzer/Checkers/GenericTaintChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/GenericTaintChecker.cpp
index c3cd3b05c5a2..4ddb7d3a1ee9 100644
--- a/clang/lib/StaticAnalyzer/Checkers/GenericTaintChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/GenericTaintChecker.cpp
@@ -225,14 +225,11 @@ GenericTaintChecker::TaintPropagationRule::getTaintPropagationRule(
     case Builtin::BIstrncpy:
     case Builtin::BIstrncat:
       return TaintPropagationRule(1, 2, 0, true);
-      break;
     case Builtin::BIstrlcpy:
     case Builtin::BIstrlcat:
       return TaintPropagationRule(1, 2, 0, false);
-      break;
     case Builtin::BIstrndup:
       return TaintPropagationRule(0, 1, ReturnValueIndex);
-      break;
 
     default:
       break;
diff --git a/clang/lib/StaticAnalyzer/Checkers/PthreadLockChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/PthreadLockChecker.cpp
index a3bbd2585919..f7ef5314e8d4 100644
--- a/clang/lib/StaticAnalyzer/Checkers/PthreadLockChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/PthreadLockChecker.cpp
@@ -135,7 +135,6 @@ void PthreadLockChecker::AcquireLock(CheckerContext &C, const CallExpr *CE,
       break;
     default:
       llvm_unreachable("Unknown tryLock locking semantics");
-      break;
     }
     assert(lockFail && lockSucc);
     C.addTransition(lockFail);
diff --git a/clang/lib/StaticAnalyzer/Core/CheckerContext.cpp b/clang/lib/StaticAnalyzer/Core/CheckerContext.cpp
index 6aaa37732591..47b7c48d452f 100644
--- a/clang/lib/StaticAnalyzer/Core/CheckerContext.cpp
+++ b/clang/lib/StaticAnalyzer/Core/CheckerContext.cpp
@@ -56,13 +56,10 @@ bool CheckerContext::isCLibraryFunction(const FunctionDecl *FD,
 }
 
 StringRef CheckerContext::getMacroNameOrSpelling(SourceLocation &Loc) {
-  if (!Loc.isMacroID()) {
-    SmallVector<char, 16> buf;
-    return Lexer::getSpelling(Loc, buf, getSourceManager(), getLangOptions());
-  } else {
+  if (Loc.isMacroID())
     return Lexer::getImmediateMacroName(Loc, getSourceManager(),
                                              getLangOptions());
-  }
-  return StringRef();
+  SmallVector<char, 16> buf;
+  return Lexer::getSpelling(Loc, buf, getSourceManager(), getLangOptions());
 }
 
diff --git a/clang/lib/StaticAnalyzer/Core/Environment.cpp b/clang/lib/StaticAnalyzer/Core/Environment.cpp
index 691530bdcb21..7d1134470783 100644
--- a/clang/lib/StaticAnalyzer/Core/Environment.cpp
+++ b/clang/lib/StaticAnalyzer/Core/Environment.cpp
@@ -59,7 +59,6 @@ SVal Environment::getSVal(const EnvironmentEntry &Entry,
       case Stmt::GenericSelectionExprClass:
         llvm_unreachable("ParenExprs and GenericSelectionExprs should "
                          "have been handled by IgnoreParens()");
-        return UnknownVal();
       case Stmt::CharacterLiteralClass: {
         const CharacterLiteral* C = cast<CharacterLiteral>(E);
         return svalBuilder.makeIntVal(C->getValue(), C->getType());
diff --git a/clang/lib/StaticAnalyzer/Core/ExprEngine.cpp b/clang/lib/StaticAnalyzer/Core/ExprEngine.cpp
index a48d69abc11b..4ccc26c1b03e 100644
--- a/clang/lib/StaticAnalyzer/Core/ExprEngine.cpp
+++ b/clang/lib/StaticAnalyzer/Core/ExprEngine.cpp
@@ -211,8 +211,6 @@ void ExprEngine::processCFGElement(const CFGElement E, ExplodedNode *Pred,
       ProcessImplicitDtor(*E.getAs<CFGImplicitDtor>(), Pred);
       return;
   }
-  currentStmtIdx = 0;
-  currentBuilderContext = 0;
 }
 
 static bool shouldRemoveDeadBindings(AnalysisManager &AMgr,
@@ -529,7 +527,6 @@ void ExprEngine::Visit(const Stmt *S, ExplodedNode *Pred,
     case Stmt::WhileStmtClass:
     case Expr::MSDependentExistsStmtClass:
       llvm_unreachable("Stmt should not be in analyzer evaluation loop");
-      break;
 
     case Stmt::GNUNullExprClass: {
       // GNU __null is a pointer-width integer, not an actual pointer.
diff --git a/clang/lib/StaticAnalyzer/Core/SimpleConstraintManager.cpp b/clang/lib/StaticAnalyzer/Core/SimpleConstraintManager.cpp
index 6fa7bb1ec527..fc573814f63e 100644
--- a/clang/lib/StaticAnalyzer/Core/SimpleConstraintManager.cpp
+++ b/clang/lib/StaticAnalyzer/Core/SimpleConstraintManager.cpp
@@ -231,16 +231,12 @@ static llvm::APSInt computeAdjustment(const SymExpr *LHS,
   switch (SE->getOpcode()) {
   case BO_Add:
     return SE->getRHS();
-    break;
   case BO_Sub:
     return -SE->getRHS();
-    break;
   default:
     // We cannot simplify non-additive operators.
     return DefaultAdjustment;
   }
-
-  return DefaultAdjustment;
 }
 
 const ProgramState *SimpleConstraintManager::assumeSymRel(const ProgramState *state,
diff --git a/clang/tools/libclang/CIndexCodeCompletion.cpp b/clang/tools/libclang/CIndexCodeCompletion.cpp
index d8ac4cf3e6c5..cfc484e67501 100644
--- a/clang/tools/libclang/CIndexCodeCompletion.cpp
+++ b/clang/tools/libclang/CIndexCodeCompletion.cpp
@@ -141,8 +141,7 @@ CXString clang_getCompletionChunkText(CXCompletionString completion_string,
     return createCXString("");
   }
 
-  // Should be unreachable, but let's be careful.
-  return createCXString((const char*)0);
+  llvm_unreachable("Invalid CodeCompletionString Kind!");
 }