diff --git a/clang/include/clang/AST/Decl.h b/clang/include/clang/AST/Decl.h
--- a/clang/include/clang/AST/Decl.h
+++ b/clang/include/clang/AST/Decl.h
@@ -539,8 +539,8 @@
 };
 
 /// Represent a C++ namespace.
-class NamespaceDecl : public NamedDecl, public DeclContext,
-                      public Redeclarable<NamespaceDecl>
+class NamespaceDecl final : public NamedDecl, public DeclContext,
+                            public Redeclarable<NamespaceDecl>
 {
   /// The starting location of the source range, pointing
   /// to either the namespace or the inline keyword.
@@ -1684,7 +1684,7 @@
 };
 
 /// Represents a parameter to a function.
-class ParmVarDecl : public VarDecl {
+class ParmVarDecl final : public VarDecl {
 public:
   enum { MaxFunctionScopeDepth = 255 };
   enum { MaxFunctionScopeIndex = 255 };
@@ -3677,7 +3677,7 @@
 /// Represents an enum.  In C++11, enums can be forward-declared
 /// with a fixed underlying type, and in C we allow them to be forward-declared
 /// with no underlying type as an extension.
-class EnumDecl : public TagDecl {
+class EnumDecl final : public TagDecl {
   // This class stores some data in DeclContext::EnumDeclBits
   // to save some space. Use the provided accessors to access it.
 
@@ -4255,7 +4255,7 @@
 /// Represents a block literal declaration, which is like an
 /// unnamed FunctionDecl.  For example:
 /// ^{ statement-body }   or   ^(int arg1, float arg2){ statement-body }
-class BlockDecl : public Decl, public DeclContext {
+class BlockDecl final : public Decl, public DeclContext {
   // This class stores some data in DeclContext::BlockDeclBits
   // to save some space. Use the provided accessors to access it.
 public:
diff --git a/clang/include/clang/AST/DeclCXX.h b/clang/include/clang/AST/DeclCXX.h
--- a/clang/include/clang/AST/DeclCXX.h
+++ b/clang/include/clang/AST/DeclCXX.h
@@ -2763,7 +2763,7 @@
 ///   operator bool();
 /// };
 /// \endcode
-class CXXConversionDecl : public CXXMethodDecl {
+class CXXConversionDecl final : public CXXMethodDecl {
   CXXConversionDecl(ASTContext &C, CXXRecordDecl *RD, SourceLocation StartLoc,
                     const DeclarationNameInfo &NameInfo, QualType T,
                     TypeSourceInfo *TInfo, bool UsesFPIntrin, bool isInline,
@@ -3956,7 +3956,7 @@
 };
 
 /// Represents a C++11 static_assert declaration.
-class StaticAssertDecl : public Decl {
+class StaticAssertDecl final : public Decl {
   llvm::PointerIntPair<Expr *, 1, bool> AssertExprAndFailed;
   StringLiteral *Message;
   SourceLocation RParenLoc;
diff --git a/clang/include/clang/AST/DeclObjC.h b/clang/include/clang/AST/DeclObjC.h
--- a/clang/include/clang/AST/DeclObjC.h
+++ b/clang/include/clang/AST/DeclObjC.h
@@ -136,7 +136,7 @@
 /// A selector represents a unique name for a method. The selector names for
 /// the above methods are setMenu:, menu, replaceSubview:with:, and defaultMenu.
 ///
-class ObjCMethodDecl : public NamedDecl, public DeclContext {
+class ObjCMethodDecl final : public NamedDecl, public DeclContext {
   // This class stores some data in DeclContext::ObjCMethodDeclBits
   // to save some space. Use the provided accessors to access it.
 
@@ -1146,8 +1146,8 @@
 ///   Unlike C++, ObjC is a single-rooted class model. In Cocoa, classes
 ///   typically inherit from NSObject (an exception is NSProxy).
 ///
-class ObjCInterfaceDecl : public ObjCContainerDecl
-                        , public Redeclarable<ObjCInterfaceDecl> {
+class ObjCInterfaceDecl final : public ObjCContainerDecl,
+                                public Redeclarable<ObjCInterfaceDecl> {
   friend class ASTContext;
 
   /// TypeForDecl - This indicates the Type object that represents this
@@ -1918,7 +1918,7 @@
 ///     id canBePackage; // framework visibility (not available in C++).
 ///   }
 ///
-class ObjCIvarDecl : public FieldDecl {
+class ObjCIvarDecl final : public FieldDecl {
   void anchor() override;
 
 public:
@@ -1995,7 +1995,7 @@
 };
 
 /// Represents a field declaration created by an \@defs(...).
-class ObjCAtDefsFieldDecl : public FieldDecl {
+class ObjCAtDefsFieldDecl final : public FieldDecl {
   ObjCAtDefsFieldDecl(DeclContext *DC, SourceLocation StartLoc,
                       SourceLocation IdLoc, IdentifierInfo *Id,
                       QualType T, Expr *BW)
diff --git a/clang/include/clang/AST/DeclTemplate.h b/clang/include/clang/AST/DeclTemplate.h
--- a/clang/include/clang/AST/DeclTemplate.h
+++ b/clang/include/clang/AST/DeclTemplate.h
@@ -1003,7 +1003,7 @@
 };
 
 /// Declaration of a template function.
-class FunctionTemplateDecl : public RedeclarableTemplateDecl {
+class FunctionTemplateDecl final : public RedeclarableTemplateDecl {
 protected:
   friend class FunctionDecl;
 
@@ -2270,7 +2270,7 @@
 };
 
 /// Declaration of a class template.
-class ClassTemplateDecl : public RedeclarableTemplateDecl {
+class ClassTemplateDecl final : public RedeclarableTemplateDecl {
 protected:
   /// Data that is common to all of the declarations of a given
   /// class template.
diff --git a/clang/include/clang/Frontend/CompilerInstance.h b/clang/include/clang/Frontend/CompilerInstance.h
--- a/clang/include/clang/Frontend/CompilerInstance.h
+++ b/clang/include/clang/Frontend/CompilerInstance.h
@@ -69,7 +69,7 @@
 /// in to the compiler instance for everything. When possible, utility functions
 /// come in two forms; a short form that reuses the CompilerInstance objects,
 /// and a long form that takes explicit instances of any required objects.
-class CompilerInstance : public ModuleLoader {
+class CompilerInstance final : public ModuleLoader {
   /// The options used in this compiler instance.
   std::shared_ptr<CompilerInvocation> Invocation;
 
diff --git a/clang/include/clang/Lex/Lexer.h b/clang/include/clang/Lex/Lexer.h
--- a/clang/include/clang/Lex/Lexer.h
+++ b/clang/include/clang/Lex/Lexer.h
@@ -75,7 +75,7 @@
 /// stream of tokens.  This provides no support for file reading or buffering,
 /// or buffering/seeking of tokens, only forward lexing is supported.  It relies
 /// on the specified Preprocessor object to handle preprocessor directives, etc.
-class Lexer : public PreprocessorLexer {
+class Lexer final : public PreprocessorLexer {
   friend class Preprocessor;
 
   void anchor() override;
diff --git a/clang/include/clang/Lex/Pragma.h b/clang/include/clang/Lex/Pragma.h
--- a/clang/include/clang/Lex/Pragma.h
+++ b/clang/include/clang/Lex/Pragma.h
@@ -93,7 +93,7 @@
 /// allowing hierarchical pragmas to be defined.  Common examples of namespaces
 /// are "\#pragma GCC", "\#pragma STDC", and "\#pragma omp", but any namespaces
 /// may be (potentially recursively) defined.
-class PragmaNamespace : public PragmaHandler {
+class PragmaNamespace final : public PragmaHandler {
   /// Handlers - This is a map of the handlers in this namespace with their name
   /// as key.
   llvm::StringMap<std::unique_ptr<PragmaHandler>> Handlers;
diff --git a/clang/include/clang/Parse/Parser.h b/clang/include/clang/Parse/Parser.h
--- a/clang/include/clang/Parse/Parser.h
+++ b/clang/include/clang/Parse/Parser.h
@@ -57,7 +57,7 @@
 /// parsing units of the grammar, productions are invoked to handle whatever has
 /// been read.
 ///
-class Parser : public CodeCompletionHandler {
+class Parser final : public CodeCompletionHandler {
   friend class ColonProtectionRAIIObject;
   friend class ParsingOpenMPDirectiveRAII;
   friend class InMessageExpressionRAIIObject;
diff --git a/clang/include/clang/Sema/CodeCompleteConsumer.h b/clang/include/clang/Sema/CodeCompleteConsumer.h
--- a/clang/include/clang/Sema/CodeCompleteConsumer.h
+++ b/clang/include/clang/Sema/CodeCompleteConsumer.h
@@ -1243,7 +1243,7 @@
 
 /// A simple code-completion consumer that prints the results it
 /// receives in a simple format.
-class PrintingCodeCompleteConsumer : public CodeCompleteConsumer {
+class PrintingCodeCompleteConsumer final : public CodeCompleteConsumer {
   /// The raw output stream.
   raw_ostream &OS;
 
diff --git a/clang/include/clang/Sema/SemaInternal.h b/clang/include/clang/Sema/SemaInternal.h
--- a/clang/include/clang/Sema/SemaInternal.h
+++ b/clang/include/clang/Sema/SemaInternal.h
@@ -82,7 +82,7 @@
   return getDepthAndIndex(UPP.first.get<const NamedDecl *>());
 }
 
-class TypoCorrectionConsumer : public VisibleDeclConsumer {
+class TypoCorrectionConsumer final : public VisibleDeclConsumer {
   typedef SmallVector<TypoCorrection, 1> TypoResultList;
   typedef llvm::StringMap<TypoResultList> TypoResultsMap;
   typedef std::map<unsigned, TypoResultsMap> TypoEditDistanceMap;
diff --git a/clang/include/clang/Serialization/ASTReader.h b/clang/include/clang/Serialization/ASTReader.h
--- a/clang/include/clang/Serialization/ASTReader.h
+++ b/clang/include/clang/Serialization/ASTReader.h
@@ -338,7 +338,7 @@
 /// The AST reader provides lazy de-serialization of declarations, as
 /// required when traversing the AST. Only those AST nodes that are
 /// actually required will be de-serialized.
-class ASTReader
+class ASTReader final
   : public ExternalPreprocessorSource,
     public ExternalPreprocessingRecordSource,
     public ExternalHeaderFileInfoSource,
diff --git a/clang/include/clang/StaticAnalyzer/Core/BugReporter/BugReporterVisitors.h b/clang/include/clang/StaticAnalyzer/Core/BugReporter/BugReporterVisitors.h
--- a/clang/include/clang/StaticAnalyzer/Core/BugReporter/BugReporterVisitors.h
+++ b/clang/include/clang/StaticAnalyzer/Core/BugReporter/BugReporterVisitors.h
@@ -163,7 +163,7 @@
 /// Tracker aimes at providing a sensible set of default behaviors that can be
 /// used by any checker, while providing mechanisms to hook into any part of the
 /// tracking process and insert checker-specific logic.
-class Tracker : public llvm::RefCountedBase<Tracker> {
+class Tracker final : public llvm::RefCountedBase<Tracker> {
 private:
   using ExpressionHandlerPtr = std::unique_ptr<ExpressionHandler>;
   using StoreHandlerPtr = std::unique_ptr<StoreHandler>;
diff --git a/clang/include/clang/StaticAnalyzer/Core/BugReporter/BugType.h b/clang/include/clang/StaticAnalyzer/Core/BugReporter/BugType.h
--- a/clang/include/clang/StaticAnalyzer/Core/BugReporter/BugType.h
+++ b/clang/include/clang/StaticAnalyzer/Core/BugReporter/BugType.h
@@ -64,7 +64,7 @@
   bool isSuppressOnSink() const { return SuppressOnSink; }
 };
 
-class BuiltinBug : public BugType {
+class BuiltinBug final : public BugType {
   const std::string desc;
   void anchor() override;
 public:
diff --git a/clang/include/clang/StaticAnalyzer/Core/PathSensitive/CallEvent.h b/clang/include/clang/StaticAnalyzer/Core/PathSensitive/CallEvent.h
--- a/clang/include/clang/StaticAnalyzer/Core/PathSensitive/CallEvent.h
+++ b/clang/include/clang/StaticAnalyzer/Core/PathSensitive/CallEvent.h
@@ -871,7 +871,7 @@
 /// Represents a call to a C++ constructor.
 ///
 /// Example: \c T(1)
-class CXXConstructorCall : public AnyCXXConstructorCall {
+class CXXConstructorCall final : public AnyCXXConstructorCall {
   friend class CallEventManager;
 
 protected:
@@ -1128,7 +1128,7 @@
 /// Represents any expression that calls an Objective-C method.
 ///
 /// This includes all of the kinds listed in ObjCMessageKind.
-class ObjCMethodCall : public CallEvent {
+class ObjCMethodCall final : public CallEvent {
   friend class CallEventManager;
 
   const PseudoObjectExpr *getContainingPseudoObjectExpr() const;
diff --git a/clang/include/clang/StaticAnalyzer/Core/PathSensitive/MemRegion.h b/clang/include/clang/StaticAnalyzer/Core/PathSensitive/MemRegion.h
--- a/clang/include/clang/StaticAnalyzer/Core/PathSensitive/MemRegion.h
+++ b/clang/include/clang/StaticAnalyzer/Core/PathSensitive/MemRegion.h
@@ -1093,7 +1093,7 @@
   const PointerType *ThisPointerTy;
 };
 
-class FieldRegion : public DeclRegion {
+class FieldRegion final : public DeclRegion {
   friend class MemRegionManager;
 
   const FieldDecl *FD;
diff --git a/clang/include/clang/StaticAnalyzer/Core/PathSensitive/SMTConstraintManager.h b/clang/include/clang/StaticAnalyzer/Core/PathSensitive/SMTConstraintManager.h
--- a/clang/include/clang/StaticAnalyzer/Core/PathSensitive/SMTConstraintManager.h
+++ b/clang/include/clang/StaticAnalyzer/Core/PathSensitive/SMTConstraintManager.h
@@ -27,7 +27,7 @@
 namespace clang {
 namespace ento {
 
-class SMTConstraintManager : public clang::ento::SimpleConstraintManager {
+class SMTConstraintManager final : public clang::ento::SimpleConstraintManager {
   mutable llvm::SMTSolverRef Solver = llvm::CreateZ3Solver();
 
 public:
diff --git a/clang/lib/Driver/ToolChains/AIX.h b/clang/lib/Driver/ToolChains/AIX.h
--- a/clang/lib/Driver/ToolChains/AIX.h
+++ b/clang/lib/Driver/ToolChains/AIX.h
@@ -19,7 +19,7 @@
 /// aix -- Directly call system default assembler and linker.
 namespace aix {
 
-class LLVM_LIBRARY_VISIBILITY Assembler : public Tool {
+class LLVM_LIBRARY_VISIBILITY Assembler final : public Tool {
 public:
   Assembler(const ToolChain &TC) : Tool("aix::Assembler", "assembler", TC) {}
 
@@ -31,7 +31,7 @@
                     const char *LinkingOutput) const override;
 };
 
-class LLVM_LIBRARY_VISIBILITY Linker : public Tool {
+class LLVM_LIBRARY_VISIBILITY Linker final : public Tool {
 public:
   Linker(const ToolChain &TC) : Tool("aix::Linker", "linker", TC) {}
 
@@ -54,7 +54,7 @@
 namespace driver {
 namespace toolchains {
 
-class LLVM_LIBRARY_VISIBILITY AIX : public ToolChain {
+class LLVM_LIBRARY_VISIBILITY AIX final : public ToolChain {
 public:
   AIX(const Driver &D, const llvm::Triple &Triple,
       const llvm::opt::ArgList &Args);
diff --git a/clang/lib/Driver/ToolChains/BareMetal.h b/clang/lib/Driver/ToolChains/BareMetal.h
--- a/clang/lib/Driver/ToolChains/BareMetal.h
+++ b/clang/lib/Driver/ToolChains/BareMetal.h
@@ -19,7 +19,7 @@
 
 namespace toolchains {
 
-class LLVM_LIBRARY_VISIBILITY BareMetal : public ToolChain {
+class LLVM_LIBRARY_VISIBILITY BareMetal final : public ToolChain {
 public:
   BareMetal(const Driver &D, const llvm::Triple &Triple,
             const llvm::opt::ArgList &Args);
@@ -77,7 +77,7 @@
 namespace tools {
 namespace baremetal {
 
-class LLVM_LIBRARY_VISIBILITY Linker : public Tool {
+class LLVM_LIBRARY_VISIBILITY Linker final : public Tool {
 public:
   Linker(const ToolChain &TC) : Tool("baremetal::Linker", "ld.lld", TC) {}
   bool isLinkJob() const override { return true; }
diff --git a/clang/lib/Driver/ToolChains/CSKYToolChain.h b/clang/lib/Driver/ToolChains/CSKYToolChain.h
--- a/clang/lib/Driver/ToolChains/CSKYToolChain.h
+++ b/clang/lib/Driver/ToolChains/CSKYToolChain.h
@@ -16,7 +16,7 @@
 namespace driver {
 namespace toolchains {
 
-class LLVM_LIBRARY_VISIBILITY CSKYToolChain : public Generic_ELF {
+class LLVM_LIBRARY_VISIBILITY CSKYToolChain final : public Generic_ELF {
 public:
   CSKYToolChain(const Driver &D, const llvm::Triple &Triple,
                 const llvm::opt::ArgList &Args);
@@ -44,7 +44,7 @@
 
 namespace tools {
 namespace CSKY {
-class LLVM_LIBRARY_VISIBILITY Linker : public Tool {
+class LLVM_LIBRARY_VISIBILITY Linker final : public Tool {
 public:
   Linker(const ToolChain &TC) : Tool("CSKY::Linker", "ld", TC) {}
   bool hasIntegratedCPP() const override { return false; }
diff --git a/clang/lib/Driver/ToolChains/CrossWindows.h b/clang/lib/Driver/ToolChains/CrossWindows.h
--- a/clang/lib/Driver/ToolChains/CrossWindows.h
+++ b/clang/lib/Driver/ToolChains/CrossWindows.h
@@ -20,7 +20,7 @@
 namespace tools {
 
 namespace CrossWindows {
-class LLVM_LIBRARY_VISIBILITY Assembler : public Tool {
+class LLVM_LIBRARY_VISIBILITY Assembler final : public Tool {
 public:
   Assembler(const ToolChain &TC) : Tool("CrossWindows::Assembler", "as", TC) {}
 
@@ -32,7 +32,7 @@
                     const char *LinkingOutput) const override;
 };
 
-class LLVM_LIBRARY_VISIBILITY Linker : public Tool {
+class LLVM_LIBRARY_VISIBILITY Linker final : public Tool {
 public:
   Linker(const ToolChain &TC) : Tool("CrossWindows::Linker", "ld", TC) {}
 
@@ -49,7 +49,7 @@
 
 namespace toolchains {
 
-class LLVM_LIBRARY_VISIBILITY CrossWindowsToolChain : public Generic_GCC {
+class LLVM_LIBRARY_VISIBILITY CrossWindowsToolChain final : public Generic_GCC {
 public:
   CrossWindowsToolChain(const Driver &D, const llvm::Triple &T,
                         const llvm::opt::ArgList &Args);
diff --git a/clang/lib/Driver/ToolChains/Darwin.h b/clang/lib/Driver/ToolChains/Darwin.h
--- a/clang/lib/Driver/ToolChains/Darwin.h
+++ b/clang/lib/Driver/ToolChains/Darwin.h
@@ -46,7 +46,7 @@
       : Tool(Name, ShortName, TC) {}
 };
 
-class LLVM_LIBRARY_VISIBILITY Assembler : public MachOTool {
+class LLVM_LIBRARY_VISIBILITY Assembler final : public MachOTool {
 public:
   Assembler(const ToolChain &TC)
       : MachOTool("darwin::Assembler", "assembler", TC) {}
@@ -59,7 +59,7 @@
                     const char *LinkingOutput) const override;
 };
 
-class LLVM_LIBRARY_VISIBILITY Linker : public MachOTool {
+class LLVM_LIBRARY_VISIBILITY Linker final : public MachOTool {
   bool NeedsTempPath(const InputInfoList &Inputs) const;
   void AddLinkArgs(Compilation &C, const llvm::opt::ArgList &Args,
                    llvm::opt::ArgStringList &CmdArgs,
@@ -78,7 +78,7 @@
                     const char *LinkingOutput) const override;
 };
 
-class LLVM_LIBRARY_VISIBILITY StaticLibTool : public MachOTool {
+class LLVM_LIBRARY_VISIBILITY StaticLibTool final : public MachOTool {
 public:
   StaticLibTool(const ToolChain &TC)
       : MachOTool("darwin::StaticLibTool", "static-lib-linker", TC) {}
@@ -92,7 +92,7 @@
                     const char *LinkingOutput) const override;
 };
 
-class LLVM_LIBRARY_VISIBILITY Lipo : public MachOTool {
+class LLVM_LIBRARY_VISIBILITY Lipo final : public MachOTool {
 public:
   Lipo(const ToolChain &TC) : MachOTool("darwin::Lipo", "lipo", TC) {}
 
@@ -104,7 +104,7 @@
                     const char *LinkingOutput) const override;
 };
 
-class LLVM_LIBRARY_VISIBILITY Dsymutil : public MachOTool {
+class LLVM_LIBRARY_VISIBILITY Dsymutil final : public MachOTool {
 public:
   Dsymutil(const ToolChain &TC)
       : MachOTool("darwin::Dsymutil", "dsymutil", TC) {}
@@ -118,7 +118,7 @@
                     const char *LinkingOutput) const override;
 };
 
-class LLVM_LIBRARY_VISIBILITY VerifyDebug : public MachOTool {
+class LLVM_LIBRARY_VISIBILITY VerifyDebug final : public MachOTool {
 public:
   VerifyDebug(const ToolChain &TC)
       : MachOTool("darwin::VerifyDebug", "dwarfdump", TC) {}
@@ -572,7 +572,7 @@
 };
 
 /// DarwinClang - The Darwin toolchain used by Clang.
-class LLVM_LIBRARY_VISIBILITY DarwinClang : public Darwin {
+class LLVM_LIBRARY_VISIBILITY DarwinClang final : public Darwin {
 public:
   DarwinClang(const Driver &D, const llvm::Triple &Triple,
               const llvm::opt::ArgList &Args);
diff --git a/clang/lib/Driver/ToolChains/Fuchsia.h b/clang/lib/Driver/ToolChains/Fuchsia.h
--- a/clang/lib/Driver/ToolChains/Fuchsia.h
+++ b/clang/lib/Driver/ToolChains/Fuchsia.h
@@ -18,7 +18,7 @@
 namespace driver {
 namespace tools {
 namespace fuchsia {
-class LLVM_LIBRARY_VISIBILITY Linker : public Tool {
+class LLVM_LIBRARY_VISIBILITY Linker final : public Tool {
 public:
   Linker(const ToolChain &TC) : Tool("fuchsia::Linker", "ld.lld", TC) {}
 
@@ -35,7 +35,7 @@
 
 namespace toolchains {
 
-class LLVM_LIBRARY_VISIBILITY Fuchsia : public ToolChain {
+class LLVM_LIBRARY_VISIBILITY Fuchsia final : public ToolChain {
 public:
   Fuchsia(const Driver &D, const llvm::Triple &Triple,
           const llvm::opt::ArgList &Args);
diff --git a/clang/lib/Driver/ToolChains/Gnu.h b/clang/lib/Driver/ToolChains/Gnu.h
--- a/clang/lib/Driver/ToolChains/Gnu.h
+++ b/clang/lib/Driver/ToolChains/Gnu.h
@@ -50,7 +50,7 @@
                     const char *LinkingOutput) const override;
 };
 
-class LLVM_LIBRARY_VISIBILITY Linker : public Tool {
+class LLVM_LIBRARY_VISIBILITY Linker final : public Tool {
 public:
   Linker(const ToolChain &TC) : Tool("GNU::Linker", "linker", TC) {}
 
@@ -63,7 +63,7 @@
                     const char *LinkingOutput) const override;
 };
 
-class LLVM_LIBRARY_VISIBILITY StaticLibTool : public Tool {
+class LLVM_LIBRARY_VISIBILITY StaticLibTool final : public Tool {
 public:
   StaticLibTool(const ToolChain &TC)
       : Tool("GNU::StaticLibTool", "static-lib-linker", TC) {}
@@ -100,7 +100,7 @@
                                    llvm::opt::ArgStringList &CmdArgs) const = 0;
 };
 
-class LLVM_LIBRARY_VISIBILITY Preprocessor : public Common {
+class LLVM_LIBRARY_VISIBILITY Preprocessor final : public Common {
 public:
   Preprocessor(const ToolChain &TC)
       : Common("gcc::Preprocessor", "gcc preprocessor", TC) {}
@@ -112,7 +112,7 @@
                            llvm::opt::ArgStringList &CmdArgs) const override;
 };
 
-class LLVM_LIBRARY_VISIBILITY Compiler : public Common {
+class LLVM_LIBRARY_VISIBILITY Compiler final : public Common {
 public:
   Compiler(const ToolChain &TC) : Common("gcc::Compiler", "gcc frontend", TC) {}
 
@@ -123,7 +123,7 @@
                            llvm::opt::ArgStringList &CmdArgs) const override;
 };
 
-class LLVM_LIBRARY_VISIBILITY Linker : public Common {
+class LLVM_LIBRARY_VISIBILITY Linker final : public Common {
 public:
   Linker(const ToolChain &TC) : Common("gcc::Linker", "linker (via gcc)", TC) {}
 
diff --git a/clang/lib/Driver/ToolChains/Hexagon.h b/clang/lib/Driver/ToolChains/Hexagon.h
--- a/clang/lib/Driver/ToolChains/Hexagon.h
+++ b/clang/lib/Driver/ToolChains/Hexagon.h
@@ -20,7 +20,7 @@
 // For Hexagon, we do not need to instantiate tools for PreProcess, PreCompile
 // and Compile.
 // We simply use "clang -cc1" for those actions.
-class LLVM_LIBRARY_VISIBILITY Assembler : public Tool {
+class LLVM_LIBRARY_VISIBILITY Assembler final : public Tool {
 public:
   Assembler(const ToolChain &TC)
       : Tool("hexagon::Assembler", "hexagon-as", TC) {}
@@ -35,7 +35,7 @@
                     const char *LinkingOutput) const override;
 };
 
-class LLVM_LIBRARY_VISIBILITY Linker : public Tool {
+class LLVM_LIBRARY_VISIBILITY Linker final : public Tool {
 public:
   Linker(const ToolChain &TC) : Tool("hexagon::Linker", "hexagon-ld", TC) {}
 
@@ -58,7 +58,7 @@
 
 namespace toolchains {
 
-class LLVM_LIBRARY_VISIBILITY HexagonToolChain : public Linux {
+class LLVM_LIBRARY_VISIBILITY HexagonToolChain final : public Linux {
 protected:
   GCCVersion GCCLibAndIncVersion;
   Tool *buildAssembler() const override;
diff --git a/clang/lib/Driver/ToolChains/Hurd.h b/clang/lib/Driver/ToolChains/Hurd.h
--- a/clang/lib/Driver/ToolChains/Hurd.h
+++ b/clang/lib/Driver/ToolChains/Hurd.h
@@ -16,7 +16,7 @@
 namespace driver {
 namespace toolchains {
 
-class LLVM_LIBRARY_VISIBILITY Hurd : public Generic_ELF {
+class LLVM_LIBRARY_VISIBILITY Hurd final : public Generic_ELF {
 public:
   Hurd(const Driver &D, const llvm::Triple &Triple,
        const llvm::opt::ArgList &Args);
diff --git a/clang/lib/Driver/ToolChains/Lanai.h b/clang/lib/Driver/ToolChains/Lanai.h
--- a/clang/lib/Driver/ToolChains/Lanai.h
+++ b/clang/lib/Driver/ToolChains/Lanai.h
@@ -16,7 +16,7 @@
 namespace driver {
 namespace toolchains {
 
-class LLVM_LIBRARY_VISIBILITY LanaiToolChain : public Generic_ELF {
+class LLVM_LIBRARY_VISIBILITY LanaiToolChain final : public Generic_ELF {
 public:
   LanaiToolChain(const Driver &D, const llvm::Triple &Triple,
                  const llvm::opt::ArgList &Args)
diff --git a/clang/lib/Driver/ToolChains/MSP430.h b/clang/lib/Driver/ToolChains/MSP430.h
--- a/clang/lib/Driver/ToolChains/MSP430.h
+++ b/clang/lib/Driver/ToolChains/MSP430.h
@@ -25,7 +25,7 @@
 namespace driver {
 namespace toolchains {
 
-class LLVM_LIBRARY_VISIBILITY MSP430ToolChain : public Generic_ELF {
+class LLVM_LIBRARY_VISIBILITY MSP430ToolChain final : public Generic_ELF {
 public:
   MSP430ToolChain(const Driver &D, const llvm::Triple &Triple,
                   const llvm::opt::ArgList &Args);
@@ -59,7 +59,7 @@
 namespace tools {
 namespace msp430 {
 
-class LLVM_LIBRARY_VISIBILITY Linker : public Tool {
+class LLVM_LIBRARY_VISIBILITY Linker final : public Tool {
 public:
   Linker(const ToolChain &TC) : Tool("MSP430::Linker", "msp430-elf-ld", TC) {}
   bool hasIntegratedCPP() const override { return false; }
diff --git a/clang/lib/Driver/ToolChains/MSVC.h b/clang/lib/Driver/ToolChains/MSVC.h
--- a/clang/lib/Driver/ToolChains/MSVC.h
+++ b/clang/lib/Driver/ToolChains/MSVC.h
@@ -23,7 +23,7 @@
 
 /// Visual studio tools.
 namespace visualstudio {
-class LLVM_LIBRARY_VISIBILITY Linker : public Tool {
+class LLVM_LIBRARY_VISIBILITY Linker final : public Tool {
 public:
   Linker(const ToolChain &TC) : Tool("visualstudio::Linker", "linker", TC) {}
 
@@ -41,7 +41,7 @@
 
 namespace toolchains {
 
-class LLVM_LIBRARY_VISIBILITY MSVCToolChain : public ToolChain {
+class LLVM_LIBRARY_VISIBILITY MSVCToolChain final : public ToolChain {
 public:
   MSVCToolChain(const Driver &D, const llvm::Triple &Triple,
                 const llvm::opt::ArgList &Args);
diff --git a/clang/lib/Driver/ToolChains/MinGW.h b/clang/lib/Driver/ToolChains/MinGW.h
--- a/clang/lib/Driver/ToolChains/MinGW.h
+++ b/clang/lib/Driver/ToolChains/MinGW.h
@@ -22,7 +22,7 @@
 
 /// MinGW -- Directly call GNU Binutils assembler and linker
 namespace MinGW {
-class LLVM_LIBRARY_VISIBILITY Assembler : public Tool {
+class LLVM_LIBRARY_VISIBILITY Assembler final : public Tool {
 public:
   Assembler(const ToolChain &TC) : Tool("MinGW::Assemble", "assembler", TC) {}
 
@@ -34,7 +34,7 @@
                     const char *LinkingOutput) const override;
 };
 
-class LLVM_LIBRARY_VISIBILITY Linker : public Tool {
+class LLVM_LIBRARY_VISIBILITY Linker final : public Tool {
 public:
   Linker(const ToolChain &TC) : Tool("MinGW::Linker", "linker", TC) {}
 
@@ -55,7 +55,7 @@
 
 namespace toolchains {
 
-class LLVM_LIBRARY_VISIBILITY MinGW : public ToolChain {
+class LLVM_LIBRARY_VISIBILITY MinGW final : public ToolChain {
 public:
   MinGW(const Driver &D, const llvm::Triple &Triple,
         const llvm::opt::ArgList &Args);
diff --git a/clang/lib/Driver/ToolChains/NaCl.h b/clang/lib/Driver/ToolChains/NaCl.h
--- a/clang/lib/Driver/ToolChains/NaCl.h
+++ b/clang/lib/Driver/ToolChains/NaCl.h
@@ -17,7 +17,7 @@
 namespace driver {
 namespace tools {
 namespace nacltools {
-class LLVM_LIBRARY_VISIBILITY AssemblerARM : public gnutools::Assembler {
+class LLVM_LIBRARY_VISIBILITY AssemblerARM final : public gnutools::Assembler {
 public:
   AssemblerARM(const ToolChain &TC) : gnutools::Assembler(TC) {}
 
@@ -27,7 +27,7 @@
                     const char *LinkingOutput) const override;
 };
 
-class LLVM_LIBRARY_VISIBILITY Linker : public Tool {
+class LLVM_LIBRARY_VISIBILITY Linker final : public Tool {
 public:
   Linker(const ToolChain &TC) : Tool("NaCl::Linker", "linker", TC) {}
 
@@ -44,7 +44,7 @@
 
 namespace toolchains {
 
-class LLVM_LIBRARY_VISIBILITY NaClToolChain : public Generic_ELF {
+class LLVM_LIBRARY_VISIBILITY NaClToolChain final : public Generic_ELF {
 public:
   NaClToolChain(const Driver &D, const llvm::Triple &Triple,
                 const llvm::opt::ArgList &Args);
diff --git a/clang/lib/Driver/ToolChains/OpenBSD.h b/clang/lib/Driver/ToolChains/OpenBSD.h
--- a/clang/lib/Driver/ToolChains/OpenBSD.h
+++ b/clang/lib/Driver/ToolChains/OpenBSD.h
@@ -20,7 +20,7 @@
 
 /// openbsd -- Directly call GNU Binutils assembler and linker
 namespace openbsd {
-class LLVM_LIBRARY_VISIBILITY Assembler : public Tool {
+class LLVM_LIBRARY_VISIBILITY Assembler final : public Tool {
 public:
   Assembler(const ToolChain &TC)
       : Tool("openbsd::Assembler", "assembler", TC) {}
@@ -33,7 +33,7 @@
                     const char *LinkingOutput) const override;
 };
 
-class LLVM_LIBRARY_VISIBILITY Linker : public Tool {
+class LLVM_LIBRARY_VISIBILITY Linker final : public Tool {
 public:
   Linker(const ToolChain &TC) : Tool("openbsd::Linker", "linker", TC) {}
 
@@ -50,7 +50,7 @@
 
 namespace toolchains {
 
-class LLVM_LIBRARY_VISIBILITY OpenBSD : public Generic_ELF {
+class LLVM_LIBRARY_VISIBILITY OpenBSD final : public Generic_ELF {
 public:
   OpenBSD(const Driver &D, const llvm::Triple &Triple,
           const llvm::opt::ArgList &Args);
diff --git a/clang/lib/Driver/ToolChains/PPCFreeBSD.h b/clang/lib/Driver/ToolChains/PPCFreeBSD.h
--- a/clang/lib/Driver/ToolChains/PPCFreeBSD.h
+++ b/clang/lib/Driver/ToolChains/PPCFreeBSD.h
@@ -15,7 +15,7 @@
 namespace driver {
 namespace toolchains {
 
-class LLVM_LIBRARY_VISIBILITY PPCFreeBSDToolChain : public FreeBSD {
+class LLVM_LIBRARY_VISIBILITY PPCFreeBSDToolChain final : public FreeBSD {
 public:
   PPCFreeBSDToolChain(const Driver &D, const llvm::Triple &Triple,
                       const llvm::opt::ArgList &Args)
diff --git a/clang/lib/Driver/ToolChains/RISCVToolchain.h b/clang/lib/Driver/ToolChains/RISCVToolchain.h
--- a/clang/lib/Driver/ToolChains/RISCVToolchain.h
+++ b/clang/lib/Driver/ToolChains/RISCVToolchain.h
@@ -16,7 +16,7 @@
 namespace driver {
 namespace toolchains {
 
-class LLVM_LIBRARY_VISIBILITY RISCVToolChain : public Generic_ELF {
+class LLVM_LIBRARY_VISIBILITY RISCVToolChain final : public Generic_ELF {
 public:
   RISCVToolChain(const Driver &D, const llvm::Triple &Triple,
                  const llvm::opt::ArgList &Args);
@@ -46,7 +46,7 @@
 
 namespace tools {
 namespace RISCV {
-class LLVM_LIBRARY_VISIBILITY Linker : public Tool {
+class LLVM_LIBRARY_VISIBILITY Linker final : public Tool {
 public:
   Linker(const ToolChain &TC) : Tool("RISCV::Linker", "ld", TC) {}
   bool hasIntegratedCPP() const override { return false; }
diff --git a/clang/lib/Driver/ToolChains/SPIRV.h b/clang/lib/Driver/ToolChains/SPIRV.h
--- a/clang/lib/Driver/ToolChains/SPIRV.h
+++ b/clang/lib/Driver/ToolChains/SPIRV.h
@@ -25,7 +25,7 @@
                                const InputInfo &Input,
                                const llvm::opt::ArgStringList &Args);
 
-class LLVM_LIBRARY_VISIBILITY Translator : public Tool {
+class LLVM_LIBRARY_VISIBILITY Translator final : public Tool {
 public:
   Translator(const ToolChain &TC)
       : Tool("SPIR-V::Translator", "llvm-spirv", TC) {}
@@ -39,7 +39,7 @@
                     const char *LinkingOutput) const override;
 };
 
-class LLVM_LIBRARY_VISIBILITY Linker : public Tool {
+class LLVM_LIBRARY_VISIBILITY Linker final : public Tool {
 public:
   Linker(const ToolChain &TC) : Tool("SPIRV::Linker", "spirv-link", TC) {}
   bool hasIntegratedCPP() const override { return false; }
diff --git a/clang/lib/Driver/ToolChains/VEToolchain.h b/clang/lib/Driver/ToolChains/VEToolchain.h
--- a/clang/lib/Driver/ToolChains/VEToolchain.h
+++ b/clang/lib/Driver/ToolChains/VEToolchain.h
@@ -16,7 +16,7 @@
 namespace driver {
 namespace toolchains {
 
-class LLVM_LIBRARY_VISIBILITY VEToolChain : public Linux {
+class LLVM_LIBRARY_VISIBILITY VEToolChain final : public Linux {
 public:
   VEToolChain(const Driver &D, const llvm::Triple &Triple,
               const llvm::opt::ArgList &Args);
diff --git a/clang/lib/Frontend/MultiplexConsumer.cpp b/clang/lib/Frontend/MultiplexConsumer.cpp
--- a/clang/lib/Frontend/MultiplexConsumer.cpp
+++ b/clang/lib/Frontend/MultiplexConsumer.cpp
@@ -81,7 +81,7 @@
 
 // This ASTMutationListener forwards its notifications to a set of
 // child listeners.
-class MultiplexASTMutationListener : public ASTMutationListener {
+class MultiplexASTMutationListener final : public ASTMutationListener {
 public:
   // Does NOT take ownership of the elements in L.
   MultiplexASTMutationListener(ArrayRef<ASTMutationListener*> L);
diff --git a/clang/lib/Sema/Sema.cpp b/clang/lib/Sema/Sema.cpp
--- a/clang/lib/Sema/Sema.cpp
+++ b/clang/lib/Sema/Sema.cpp
@@ -130,7 +130,7 @@
 namespace clang {
 namespace sema {
 
-class SemaPPCallbacks : public PPCallbacks {
+class SemaPPCallbacks final : public PPCallbacks {
   Sema *S = nullptr;
   llvm::SmallVector<SourceLocation, 8> IncludeStack;
 
diff --git a/clang/lib/StaticAnalyzer/Checkers/RetainCountChecker/RetainCountDiagnostics.h b/clang/lib/StaticAnalyzer/Checkers/RetainCountChecker/RetainCountDiagnostics.h
--- a/clang/lib/StaticAnalyzer/Checkers/RetainCountChecker/RetainCountDiagnostics.h
+++ b/clang/lib/StaticAnalyzer/Checkers/RetainCountChecker/RetainCountDiagnostics.h
@@ -24,7 +24,7 @@
 namespace ento {
 namespace retaincountchecker {
 
-class RefCountBug : public BugType {
+class RefCountBug final : public BugType {
 public:
   enum RefCountBugKind {
     UseAfterRelease,
diff --git a/llvm/include/llvm/CodeGen/GlobalISel/GISelKnownBits.h b/llvm/include/llvm/CodeGen/GlobalISel/GISelKnownBits.h
--- a/llvm/include/llvm/CodeGen/GlobalISel/GISelKnownBits.h
+++ b/llvm/include/llvm/CodeGen/GlobalISel/GISelKnownBits.h
@@ -26,7 +26,7 @@
 class TargetLowering;
 class DataLayout;
 
-class GISelKnownBits : public GISelChangeObserver {
+class GISelKnownBits final : public GISelChangeObserver {
   MachineFunction &MF;
   MachineRegisterInfo &MRI;
   const TargetLowering &TL;
diff --git a/llvm/include/llvm/DebugInfo/DWARF/DWARFAcceleratorTable.h b/llvm/include/llvm/DebugInfo/DWARF/DWARFAcceleratorTable.h
--- a/llvm/include/llvm/DebugInfo/DWARF/DWARFAcceleratorTable.h
+++ b/llvm/include/llvm/DebugInfo/DWARF/DWARFAcceleratorTable.h
@@ -80,7 +80,7 @@
 
 /// This implements the Apple accelerator table format, a precursor of the
 /// DWARF 5 accelerator table format.
-class AppleAcceleratorTable : public DWARFAcceleratorTable {
+class AppleAcceleratorTable final : public DWARFAcceleratorTable {
   struct Header {
     uint32_t Magic;
     uint16_t Version;
@@ -228,7 +228,7 @@
 /// The last segment consists of a list of entries, which is a 0-terminated list
 /// referenced by the name table and interpreted with the help of the
 /// abbreviation table.
-class DWARFDebugNames : public DWARFAcceleratorTable {
+class DWARFDebugNames final : public DWARFAcceleratorTable {
 public:
   class NameIndex;
   class NameIterator;
@@ -323,7 +323,7 @@
 
   /// Error returned by NameIndex::getEntry to report it has reached the end of
   /// the entry list.
-  class SentinelError : public ErrorInfo<SentinelError> {
+  class SentinelError final : public ErrorInfo<SentinelError> {
   public:
     static char ID;
 
diff --git a/llvm/include/llvm/DebugInfo/DWARF/DWARFContext.h b/llvm/include/llvm/DebugInfo/DWARF/DWARFContext.h
--- a/llvm/include/llvm/DebugInfo/DWARF/DWARFContext.h
+++ b/llvm/include/llvm/DebugInfo/DWARF/DWARFContext.h
@@ -44,7 +44,7 @@
 /// DWARFContext
 /// This data structure is the top level entity that deals with dwarf debug
 /// information parsing. The actual data is supplied through DWARFObj.
-class DWARFContext : public DIContext {
+class DWARFContext final : public DIContext {
   DWARFUnitVector NormalUnits;
   Optional<DenseMap<uint64_t, DWARFTypeUnit*>> NormalTypeUnits;
   std::unique_ptr<DWARFUnitIndex> CUIndex;
diff --git a/llvm/include/llvm/DebugInfo/DWARF/DWARFDebugFrame.h b/llvm/include/llvm/DebugInfo/DWARF/DWARFDebugFrame.h
--- a/llvm/include/llvm/DebugInfo/DWARF/DWARFDebugFrame.h
+++ b/llvm/include/llvm/DebugInfo/DWARF/DWARFDebugFrame.h
@@ -564,7 +564,7 @@
 };
 
 /// DWARF Common Information Entry (CIE)
-class CIE : public FrameEntry {
+class CIE final : public FrameEntry {
 public:
   // CIEs (and FDEs) are simply container classes, so the only sensible way to
   // create them is by providing the full parsed contents in the constructor.
@@ -623,7 +623,7 @@
 };
 
 /// DWARF Frame Description Entry (FDE)
-class FDE : public FrameEntry {
+class FDE final : public FrameEntry {
 public:
   FDE(bool IsDWARF64, uint64_t Offset, uint64_t Length, uint64_t CIEPointer,
       uint64_t InitialLocation, uint64_t AddressRange, CIE *Cie,
diff --git a/llvm/include/llvm/DebugInfo/DWARF/DWARFDebugLoc.h b/llvm/include/llvm/DebugInfo/DWARF/DWARFDebugLoc.h
--- a/llvm/include/llvm/DebugInfo/DWARF/DWARFDebugLoc.h
+++ b/llvm/include/llvm/DebugInfo/DWARF/DWARFDebugLoc.h
@@ -146,7 +146,7 @@
   uint16_t Version;
 };
 
-class ResolverError : public ErrorInfo<ResolverError> {
+class ResolverError final : public ErrorInfo<ResolverError> {
 public:
   static char ID;
 
diff --git a/llvm/include/llvm/Object/COFF.h b/llvm/include/llvm/Object/COFF.h
--- a/llvm/include/llvm/Object/COFF.h
+++ b/llvm/include/llvm/Object/COFF.h
@@ -785,7 +785,7 @@
   support::ulittle16_t HashAlgorithm;
 };
 
-class COFFObjectFile : public ObjectFile {
+class COFFObjectFile final : public ObjectFile {
 private:
   COFFObjectFile(MemoryBufferRef Object);
 
diff --git a/llvm/include/llvm/Object/MachO.h b/llvm/include/llvm/Object/MachO.h
--- a/llvm/include/llvm/Object/MachO.h
+++ b/llvm/include/llvm/Object/MachO.h
@@ -403,7 +403,7 @@
 };
 using fixup_iterator = content_iterator<MachOChainedFixupEntry>;
 
-class MachOObjectFile : public ObjectFile {
+class MachOObjectFile final : public ObjectFile {
 public:
   struct LoadCommandInfo {
     const char *Ptr;      // Where in memory the load command is.
diff --git a/llvm/include/llvm/Object/Wasm.h b/llvm/include/llvm/Object/Wasm.h
--- a/llvm/include/llvm/Object/Wasm.h
+++ b/llvm/include/llvm/Object/Wasm.h
@@ -117,7 +117,7 @@
   wasm::WasmDataSegment Data;
 };
 
-class WasmObjectFile : public ObjectFile {
+class WasmObjectFile final : public ObjectFile {
 
 public:
   WasmObjectFile(MemoryBufferRef Object, Error &Err);
diff --git a/llvm/include/llvm/Object/XCOFFObjectFile.h b/llvm/include/llvm/Object/XCOFFObjectFile.h
--- a/llvm/include/llvm/Object/XCOFFObjectFile.h
+++ b/llvm/include/llvm/Object/XCOFFObjectFile.h
@@ -470,7 +470,7 @@
 
 class XCOFFSymbolRef;
 
-class XCOFFObjectFile : public ObjectFile {
+class XCOFFObjectFile final : public ObjectFile {
 private:
   const void *FileHeader = nullptr;
   const void *AuxiliaryHeader = nullptr;
diff --git a/llvm/include/llvm/ProfileData/InstrProfReader.h b/llvm/include/llvm/ProfileData/InstrProfReader.h
--- a/llvm/include/llvm/ProfileData/InstrProfReader.h
+++ b/llvm/include/llvm/ProfileData/InstrProfReader.h
@@ -576,7 +576,7 @@
 };
 
 /// Reader for the indexed binary instrprof format.
-class IndexedInstrProfReader : public InstrProfReader {
+class IndexedInstrProfReader final : public InstrProfReader {
 private:
   /// The profile data file contents.
   std::unique_ptr<MemoryBuffer> DataBuffer;
diff --git a/llvm/include/llvm/Support/VirtualFileSystem.h b/llvm/include/llvm/Support/VirtualFileSystem.h
--- a/llvm/include/llvm/Support/VirtualFileSystem.h
+++ b/llvm/include/llvm/Support/VirtualFileSystem.h
@@ -364,7 +364,7 @@
 /// top-most (most recently added) directory are used.  When there is a file
 /// that exists in more than one file system, the file in the top-most file
 /// system overrides the other(s).
-class OverlayFileSystem : public FileSystem {
+class OverlayFileSystem final : public FileSystem {
   using FileSystemList = SmallVector<IntrusiveRefCntPtr<FileSystem>, 1>;
 
   /// The stack of file systems, implemented as a list in order of
@@ -726,7 +726,7 @@
 /// FIXME: 'use-external-name' causes behaviour that's inconsistent with how
 /// "real" filesystems behave. Maybe there should be a separate channel for
 /// this information.
-class RedirectingFileSystem : public vfs::FileSystem {
+class RedirectingFileSystem final : public vfs::FileSystem {
 public:
   enum EntryKind { EK_Directory, EK_DirectoryRemap, EK_File };
   enum NameKind { NK_NotSet, NK_External, NK_Virtual };
@@ -759,7 +759,7 @@
   };
 
   /// A directory in the vfs with explicitly specified contents.
-  class DirectoryEntry : public Entry {
+  class DirectoryEntry final : public Entry {
     std::vector<std::unique_ptr<Entry>> Contents;
     Status S;
 
@@ -828,7 +828,7 @@
 
   /// A directory in the vfs that maps to a directory in the external file
   /// system.
-  class DirectoryRemapEntry : public RemapEntry {
+  class DirectoryRemapEntry final : public RemapEntry {
   public:
     DirectoryRemapEntry(StringRef Name, StringRef ExternalContentsPath,
                         NameKind UseName)
@@ -840,7 +840,7 @@
   };
 
   /// A file in the vfs that maps to a file in the external file system.
-  class FileEntry : public RemapEntry {
+  class FileEntry final : public RemapEntry {
   public:
     FileEntry(StringRef Name, StringRef ExternalContentsPath, NameKind UseName)
         : RemapEntry(EK_File, Name, ExternalContentsPath, UseName) {}
diff --git a/llvm/include/llvm/TableGen/Record.h b/llvm/include/llvm/TableGen/Record.h
--- a/llvm/include/llvm/TableGen/Record.h
+++ b/llvm/include/llvm/TableGen/Record.h
@@ -183,7 +183,7 @@
 
 /// 'list<Ty>' - Represent a list of element values, all of which must be of
 /// the specified type. The type is stored in ElementTy.
-class ListRecTy : public RecTy {
+class ListRecTy final : public RecTy {
   friend ListRecTy *RecTy::getListTy();
 
   RecTy *ElementTy;
@@ -575,7 +575,7 @@
 };
 
 /// '7' - Represent an initialization by a literal integer value.
-class IntInit : public TypedInit {
+class IntInit final : public TypedInit {
   int64_t Value;
 
   explicit IntInit(RecordKeeper &RK, int64_t V)
@@ -605,7 +605,7 @@
 };
 
 /// "anonymous_n" - Represent an anonymous record name
-class AnonymousNameInit : public TypedInit {
+class AnonymousNameInit final : public TypedInit {
   unsigned Value;
 
   explicit AnonymousNameInit(RecordKeeper &RK, unsigned V)
@@ -635,7 +635,7 @@
 };
 
 /// "foo" - Represent an initialization by a string value.
-class StringInit : public TypedInit {
+class StringInit final : public TypedInit {
 public:
   enum StringFormat {
     SF_String, // Format as "text"
@@ -782,7 +782,7 @@
 
 /// !op (X) - Transform an init.
 ///
-class UnOpInit : public OpInit, public FoldingSetNode {
+class UnOpInit final : public OpInit, public FoldingSetNode {
 public:
   enum UnaryOp : uint8_t { CAST, NOT, HEAD, TAIL, SIZE, EMPTY, GETDAGOP, LOG2 };
 
@@ -1152,7 +1152,7 @@
 };
 
 /// 'Opcode' - Represent a reference to an entire variable object.
-class VarInit : public TypedInit {
+class VarInit final : public TypedInit {
   Init *VarName;
 
   explicit VarInit(Init *VN, RecTy *T)
@@ -1259,7 +1259,7 @@
 };
 
 /// AL - Represent a reference to a 'def' in the description
-class DefInit : public TypedInit {
+class DefInit final : public TypedInit {
   friend class Record;
 
   Record *Def;
diff --git a/llvm/lib/Support/VirtualFileSystem.cpp b/llvm/lib/Support/VirtualFileSystem.cpp
--- a/llvm/lib/Support/VirtualFileSystem.cpp
+++ b/llvm/lib/Support/VirtualFileSystem.cpp
@@ -620,7 +620,7 @@
   virtual std::string toString(unsigned Indent) const = 0;
 };
 
-class InMemoryFile : public InMemoryNode {
+class InMemoryFile final : public InMemoryNode {
   Status Stat;
   std::unique_ptr<llvm::MemoryBuffer> Buffer;
 
@@ -722,7 +722,7 @@
 };
 } // namespace
 
-class InMemoryDirectory : public InMemoryNode {
+class InMemoryDirectory final : public InMemoryNode {
   Status Stat;
   llvm::StringMap<std::unique_ptr<InMemoryNode>> Entries;
 
@@ -1066,7 +1066,7 @@
 }
 
 /// Adaptor from InMemoryDir::iterator to directory_iterator.
-class InMemoryFileSystem::DirIterator : public llvm::vfs::detail::DirIterImpl {
+class InMemoryFileSystem::DirIterator final : public llvm::vfs::detail::DirIterImpl {
   const InMemoryFileSystem *FS;
   detail::InMemoryDirectory::const_iterator I;
   detail::InMemoryDirectory::const_iterator E;
@@ -1231,7 +1231,7 @@
 
 /// Directory iterator implementation for \c RedirectingFileSystem's
 /// directory entries.
-class llvm::vfs::RedirectingFSDirIterImpl
+class llvm::vfs::RedirectingFSDirIterImpl final
     : public llvm::vfs::detail::DirIterImpl {
   std::string Dir;
   RedirectingFileSystem::DirectoryEntry::iterator Current, End;
diff --git a/llvm/lib/Target/AArch64/AArch64FrameLowering.h b/llvm/lib/Target/AArch64/AArch64FrameLowering.h
--- a/llvm/lib/Target/AArch64/AArch64FrameLowering.h
+++ b/llvm/lib/Target/AArch64/AArch64FrameLowering.h
@@ -18,7 +18,7 @@
 
 namespace llvm {
 
-class AArch64FrameLowering : public TargetFrameLowering {
+class AArch64FrameLowering final : public TargetFrameLowering {
 public:
   explicit AArch64FrameLowering()
       : TargetFrameLowering(StackGrowsDown, Align(16), 0, Align(16),
diff --git a/llvm/lib/Target/AArch64/AArch64ISelLowering.h b/llvm/lib/Target/AArch64/AArch64ISelLowering.h
--- a/llvm/lib/Target/AArch64/AArch64ISelLowering.h
+++ b/llvm/lib/Target/AArch64/AArch64ISelLowering.h
@@ -494,7 +494,7 @@
 
 class AArch64Subtarget;
 
-class AArch64TargetLowering : public TargetLowering {
+class AArch64TargetLowering final : public TargetLowering {
 public:
   explicit AArch64TargetLowering(const TargetMachine &TM,
                                  const AArch64Subtarget &STI);
diff --git a/llvm/lib/Target/AArch64/MCTargetDesc/AArch64InstPrinter.h b/llvm/lib/Target/AArch64/MCTargetDesc/AArch64InstPrinter.h
--- a/llvm/lib/Target/AArch64/MCTargetDesc/AArch64InstPrinter.h
+++ b/llvm/lib/Target/AArch64/MCTargetDesc/AArch64InstPrinter.h
@@ -230,7 +230,7 @@
                        const MCSubtargetInfo &STI, raw_ostream &O);
 };
 
-class AArch64AppleInstPrinter : public AArch64InstPrinter {
+class AArch64AppleInstPrinter final : public AArch64InstPrinter {
 public:
   AArch64AppleInstPrinter(const MCAsmInfo &MAI, const MCInstrInfo &MII,
                           const MCRegisterInfo &MRI);
diff --git a/llvm/lib/Target/ARM/ARMISelLowering.h b/llvm/lib/Target/ARM/ARMISelLowering.h
--- a/llvm/lib/Target/ARM/ARMISelLowering.h
+++ b/llvm/lib/Target/ARM/ARMISelLowering.h
@@ -387,7 +387,7 @@
   //===--------------------------------------------------------------------===//
   //  ARMTargetLowering - ARM Implementation of the TargetLowering interface
 
-  class ARMTargetLowering : public TargetLowering {
+  class ARMTargetLowering final : public TargetLowering {
   public:
     explicit ARMTargetLowering(const TargetMachine &TM,
                                const ARMSubtarget &STI);
diff --git a/llvm/lib/Target/ARM/ARMSubtarget.h b/llvm/lib/Target/ARM/ARMSubtarget.h
--- a/llvm/lib/Target/ARM/ARMSubtarget.h
+++ b/llvm/lib/Target/ARM/ARMSubtarget.h
@@ -44,7 +44,7 @@
 class GlobalValue;
 class StringRef;
 
-class ARMSubtarget : public ARMGenSubtargetInfo {
+class ARMSubtarget final : public ARMGenSubtargetInfo {
 protected:
   enum ARMProcFamilyEnum {
     Others,
diff --git a/llvm/lib/Target/ARM/MCTargetDesc/ARMInstPrinter.h b/llvm/lib/Target/ARM/MCTargetDesc/ARMInstPrinter.h
--- a/llvm/lib/Target/ARM/MCTargetDesc/ARMInstPrinter.h
+++ b/llvm/lib/Target/ARM/MCTargetDesc/ARMInstPrinter.h
@@ -18,7 +18,7 @@
 
 namespace llvm {
 
-class ARMInstPrinter : public MCInstPrinter {
+class ARMInstPrinter final : public MCInstPrinter {
 public:
   ARMInstPrinter(const MCAsmInfo &MAI, const MCInstrInfo &MII,
                  const MCRegisterInfo &MRI);
diff --git a/llvm/lib/Target/X86/X86FrameLowering.h b/llvm/lib/Target/X86/X86FrameLowering.h
--- a/llvm/lib/Target/X86/X86FrameLowering.h
+++ b/llvm/lib/Target/X86/X86FrameLowering.h
@@ -25,7 +25,7 @@
 class X86Subtarget;
 class X86RegisterInfo;
 
-class X86FrameLowering : public TargetFrameLowering {
+class X86FrameLowering final : public TargetFrameLowering {
 public:
   X86FrameLowering(const X86Subtarget &STI, MaybeAlign StackAlignOverride);
 
diff --git a/llvm/utils/TableGen/DAGISelMatcher.h b/llvm/utils/TableGen/DAGISelMatcher.h
--- a/llvm/utils/TableGen/DAGISelMatcher.h
+++ b/llvm/utils/TableGen/DAGISelMatcher.h
@@ -448,7 +448,7 @@
 
 /// CheckOpcodeMatcher - This checks to see if the current node has the
 /// specified opcode, if not it fails to match.
-class CheckOpcodeMatcher : public Matcher {
+class CheckOpcodeMatcher final : public Matcher {
   const SDNodeInfo &Opcode;
 public:
   CheckOpcodeMatcher(const SDNodeInfo &opcode)
@@ -494,7 +494,7 @@
 
 /// CheckTypeMatcher - This checks to see if the current node has the
 /// specified type at the specified result, if not it fails to match.
-class CheckTypeMatcher : public Matcher {
+class CheckTypeMatcher final : public Matcher {
   MVT::SimpleValueType Type;
   unsigned ResNo;
 public:
diff --git a/llvm/utils/TableGen/GlobalISel/GIMatchDagPredicate.h b/llvm/utils/TableGen/GlobalISel/GIMatchDagPredicate.h
--- a/llvm/utils/TableGen/GlobalISel/GIMatchDagPredicate.h
+++ b/llvm/utils/TableGen/GlobalISel/GIMatchDagPredicate.h
@@ -80,7 +80,7 @@
 #endif // if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
 };
 
-class GIMatchDagOpcodePredicate : public GIMatchDagPredicate {
+class GIMatchDagOpcodePredicate final : public GIMatchDagPredicate {
   const CodeGenInstruction &Instr;
 
 public:
@@ -100,7 +100,7 @@
 #endif // if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
 };
 
-class GIMatchDagOneOfOpcodesPredicate : public GIMatchDagPredicate {
+class GIMatchDagOneOfOpcodesPredicate final : public GIMatchDagPredicate {
   SmallVector<const CodeGenInstruction *, 4> Instrs;
 
 public:
@@ -123,7 +123,7 @@
 #endif // if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
 };
 
-class GIMatchDagSameMOPredicate : public GIMatchDagPredicate {
+class GIMatchDagSameMOPredicate final : public GIMatchDagPredicate {
 public:
   GIMatchDagSameMOPredicate(GIMatchDagContext &Ctx, StringRef Name);
 
diff --git a/llvm/utils/TableGen/GlobalISel/GIMatchTree.h b/llvm/utils/TableGen/GlobalISel/GIMatchTree.h
--- a/llvm/utils/TableGen/GlobalISel/GIMatchTree.h
+++ b/llvm/utils/TableGen/GlobalISel/GIMatchTree.h
@@ -553,7 +553,7 @@
 ///   result is that the cases that don't match the superset will match the
 ///   subset rule, while the ones that do match the superset will match either
 ///   (which one is algorithm dependent but will usually be the superset).
-class GIMatchTreeOpcodePartitioner : public GIMatchTreePartitioner {
+class GIMatchTreeOpcodePartitioner final : public GIMatchTreePartitioner {
   unsigned InstrID;
   DenseMap<const CodeGenInstruction *, unsigned> InstrToPartition;
   std::vector<const CodeGenInstruction *> PartitionToInstr;
@@ -582,7 +582,7 @@
                                      StringRef Indent) const override;
 };
 
-class GIMatchTreeVRegDefPartitioner : public GIMatchTreePartitioner {
+class GIMatchTreeVRegDefPartitioner final : public GIMatchTreePartitioner {
   unsigned NewInstrID = -1;
   unsigned InstrID;
   unsigned OpIdx;