diff --git a/llvm/include/llvm/Support/TargetRegistry.h b/llvm/include/llvm/Support/TargetRegistry.h
@@ -54,6 +54,7 @@ class MCSymbolizer;
 class MCTargetAsmParser;
 class MCTargetOptions;
 class MCTargetStreamer;
+class raw_ostream;
 class raw_pwrite_stream;
 class TargetMachine;
 class TargetOptions;
@@ -96,75 +97,75 @@ class Target {
 public:
   friend struct TargetRegistry;
 
-  typedef bool (*ArchMatchFnTy)(Triple::ArchType Arch);
+  using ArchMatchFnTy = bool (*)(Triple::ArchType Arch);
 
-  typedef MCAsmInfo *(*MCAsmInfoCtorFnTy)(const MCRegisterInfo &MRI,
-                                          const Triple &TT);
-  typedef void (*MCAdjustCodeGenOptsFnTy)(const Triple &TT, Reloc::Model RM,
-                                          CodeModel::Model &CM);
+  using MCAsmInfoCtorFnTy = MCAsmInfo *(*)(const MCRegisterInfo &MRI,
+                                           const Triple &TT);
+  using MCAdjustCodeGenOptsFnTy = void (*)(const Triple &TT, Reloc::Model RM,
+                                           CodeModel::Model &CM);
 
-  typedef MCInstrInfo *(*MCInstrInfoCtorFnTy)(void);
-  typedef MCInstrAnalysis *(*MCInstrAnalysisCtorFnTy)(const MCInstrInfo *Info);
-  typedef MCRegisterInfo *(*MCRegInfoCtorFnTy)(const Triple &TT);
-  typedef MCSubtargetInfo *(*MCSubtargetInfoCtorFnTy)(const Triple &TT,
-                                                      StringRef CPU,
-                                                      StringRef Features);
-  typedef TargetMachine *(*TargetMachineCtorTy)(
+  using MCInstrInfoCtorFnTy = MCInstrInfo *(*)();
+  using MCInstrAnalysisCtorFnTy = MCInstrAnalysis *(*)(const MCInstrInfo *Info);
+  using MCRegInfoCtorFnTy = MCRegisterInfo *(*)(const Triple &TT);
+  using MCSubtargetInfoCtorFnTy = MCSubtargetInfo *(*)(const Triple &TT,
+                                                       StringRef CPU,
+                                                       StringRef Features);
+  using TargetMachineCtorTy = TargetMachine *(*)(
       const Target &T, const Triple &TT, StringRef CPU, StringRef Features,
       const TargetOptions &Options, Optional<Reloc::Model> RM,
       CodeModel::Model CM, CodeGenOpt::Level OL);
   // If it weren't for layering issues (this header is in llvm/Support, but
   // depends on MC?) this should take the Streamer by value rather than rvalue
   // reference.
-  typedef AsmPrinter *(*AsmPrinterCtorTy)(
+  using AsmPrinterCtorTy = AsmPrinter *(*)(
       TargetMachine &TM, std::unique_ptr<MCStreamer> &&Streamer);
-  typedef MCAsmBackend *(*MCAsmBackendCtorTy)(const Target &T,
-                                              const MCRegisterInfo &MRI,
-                                              const Triple &TT, StringRef CPU,
-                                              const MCTargetOptions &Options);
-  typedef MCTargetAsmParser *(*MCAsmParserCtorTy)(
+  using MCAsmBackendCtorTy = MCAsmBackend *(*)(const Target &T,
+                                               const MCRegisterInfo &MRI,
+                                               const Triple &TT, StringRef CPU,
+                                               const MCTargetOptions &Options);
+  using MCAsmParserCtorTy = MCTargetAsmParser *(*)(
       const MCSubtargetInfo &STI, MCAsmParser &P, const MCInstrInfo &MII,
       const MCTargetOptions &Options);
-  typedef MCDisassembler *(*MCDisassemblerCtorTy)(const Target &T,
-                                                  const MCSubtargetInfo &STI,
-                                                  MCContext &Ctx);
-  typedef MCInstPrinter *(*MCInstPrinterCtorTy)(const Triple &T,
-                                                unsigned SyntaxVariant,
-                                                const MCAsmInfo &MAI,
-                                                const MCInstrInfo &MII,
-                                                const MCRegisterInfo &MRI);
-  typedef MCCodeEmitter *(*MCCodeEmitterCtorTy)(const MCInstrInfo &II,
-                                                const MCRegisterInfo &MRI,
-                                                MCContext &Ctx);
-  typedef MCStreamer *(*ELFStreamerCtorTy)(const Triple &T, MCContext &Ctx,
-                                           MCAsmBackend &TAB,
-                                           raw_pwrite_stream &OS,
-                                           MCCodeEmitter *Emitter,
-                                           bool RelaxAll);
-  typedef MCStreamer *(*MachOStreamerCtorTy)(MCContext &Ctx, MCAsmBackend &TAB,
-                                             raw_pwrite_stream &OS,
-                                             MCCodeEmitter *Emitter,
-                                             bool RelaxAll,
-                                             bool DWARFMustBeAtTheEnd);
-  typedef MCStreamer *(*COFFStreamerCtorTy)(MCContext &Ctx, MCAsmBackend &TAB,
-                                            raw_pwrite_stream &OS,
-                                            MCCodeEmitter *Emitter,
-                                            bool RelaxAll,
-                                            bool IncrementalLinkerCompatible);
-  typedef MCStreamer *(*WasmStreamerCtorTy)(const Triple &T, MCContext &Ctx,
+  using MCDisassemblerCtorTy = MCDisassembler *(*)(const Target &T,
+                                                   const MCSubtargetInfo &STI,
+                                                   MCContext &Ctx);
+  using MCInstPrinterCtorTy = MCInstPrinter *(*)(const Triple &T,
+                                                 unsigned SyntaxVariant,
+                                                 const MCAsmInfo &MAI,
+                                                 const MCInstrInfo &MII,
+                                                 const MCRegisterInfo &MRI);
+  using MCCodeEmitterCtorTy = MCCodeEmitter *(*)(const MCInstrInfo &II,
+                                                 const MCRegisterInfo &MRI,
+                                                 MCContext &Ctx);
+  using ELFStreamerCtorTy = MCStreamer *(*)(const Triple &T, MCContext &Ctx,
                                             MCAsmBackend &TAB,
                                             raw_pwrite_stream &OS,
                                             MCCodeEmitter *Emitter,
                                             bool RelaxAll);
-  typedef MCTargetStreamer *(*NullTargetStreamerCtorTy)(MCStreamer &S);
-  typedef MCTargetStreamer *(*AsmTargetStreamerCtorTy)(
+  using MachOStreamerCtorTy = MCStreamer *(*)(MCContext &Ctx, MCAsmBackend &TAB,
+                                              raw_pwrite_stream &OS,
+                                              MCCodeEmitter *Emitter,
+                                              bool RelaxAll,
+                                              bool DWARFMustBeAtTheEnd);
+  using COFFStreamerCtorTy = MCStreamer *(*)(MCContext &Ctx, MCAsmBackend &TAB,
+                                             raw_pwrite_stream &OS,
+                                             MCCodeEmitter *Emitter,
+                                             bool RelaxAll,
+                                             bool IncrementalLinkerCompatible);
+  using WasmStreamerCtorTy = MCStreamer *(*)(const Triple &T, MCContext &Ctx,
+                                             MCAsmBackend &TAB,
+                                             raw_pwrite_stream &OS,
+                                             MCCodeEmitter *Emitter,
+                                             bool RelaxAll);
+  using NullTargetStreamerCtorTy = MCTargetStreamer *(*)(MCStreamer &S);
+  using AsmTargetStreamerCtorTy = MCTargetStreamer *(*)(
       MCStreamer &S, formatted_raw_ostream &OS, MCInstPrinter *InstPrint,
       bool IsVerboseAsm);
-  typedef MCTargetStreamer *(*ObjectTargetStreamerCtorTy)(
+  using ObjectTargetStreamerCtorTy = MCTargetStreamer *(*)(
       MCStreamer &S, const MCSubtargetInfo &STI);
-  typedef MCRelocationInfo *(*MCRelocationInfoCtorTy)(const Triple &TT,
-                                                      MCContext &Ctx);
-  typedef MCSymbolizer *(*MCSymbolizerCtorTy)(
+  using MCRelocationInfoCtorTy = MCRelocationInfo *(*)(const Triple &TT,
+                                                       MCContext &Ctx);
+  using MCSymbolizerCtorTy = MCSymbolizer *(*)(
       const Triple &TT, LLVMOpInfoCallback GetOpInfo,
       LLVMSymbolLookupCallback SymbolLookUp, void *DisInfo, MCContext *Ctx,
       std::unique_ptr<MCRelocationInfo> &&RelInfo);

diff --git a/llvm/include/llvm/Support/YAMLParser.h b/llvm/include/llvm/Support/YAMLParser.h
@@ -1,4 +1,4 @@
-//===--- YAMLParser.h - Simple YAML parser --------------------------------===//
+//===- YAMLParser.h - Simple YAML parser ------------------------*- C++ -*-===//
 //
 //                     The LLVM Compiler Infrastructure
 //
@@ -41,20 +41,25 @@
 #include "llvm/ADT/StringRef.h"
 #include "llvm/Support/Allocator.h"
 #include "llvm/Support/SMLoc.h"
+#include <cassert>
+#include <cstddef>
+#include <iterator>
 #include <map>
+#include <memory>
+#include <string>
 #include <system_error>
-#include <utility>
 
 namespace llvm {
+
 class MemoryBufferRef;
 class SourceMgr;
-class Twine;
 class raw_ostream;
+class Twine;
 
 namespace yaml {
 
-class document_iterator;
 class Document;
+class document_iterator;
 class Node;
 class Scanner;
 struct Token;
@@ -87,6 +92,7 @@ class Stream {
   document_iterator end();
   void skip();
   bool failed();
+
   bool validate() {
     skip();
     return !failed();
@@ -95,10 +101,10 @@ class Stream {
   void printError(Node *N, const Twine &Msg);
 
 private:
+  friend class Document;
+
   std::unique_ptr<Scanner> scanner;
   std::unique_ptr<Document> CurrentDoc;
-
-  friend class Document;
 };
 
 /// \brief Abstract base class for all Nodes.
@@ -119,6 +125,18 @@ class Node {
   Node(unsigned int Type, std::unique_ptr<Document> &, StringRef Anchor,
        StringRef Tag);
 
+  void *operator new(size_t Size, BumpPtrAllocator &Alloc,
+                     size_t Alignment = 16) noexcept {
+    return Alloc.Allocate(Size, Alignment);
+  }
+
+  void operator delete(void *Ptr, BumpPtrAllocator &Alloc,
+                       size_t Size) noexcept {
+    Alloc.Deallocate(Ptr, Size);
+  }
+
+  void operator delete(void *) noexcept = delete;
+
   /// \brief Get the value of the anchor attached to this node. If it does not
   ///        have one, getAnchor().size() will be 0.
   StringRef getAnchor() const { return Anchor; }
@@ -146,22 +164,10 @@ class Node {
 
   unsigned int getType() const { return TypeID; }
 
-  void *operator new(size_t Size, BumpPtrAllocator &Alloc,
-                     size_t Alignment = 16) noexcept {
-    return Alloc.Allocate(Size, Alignment);
-  }
-
-  void operator delete(void *Ptr, BumpPtrAllocator &Alloc,
-                       size_t Size) noexcept {
-    Alloc.Deallocate(Ptr, Size);
-  }
-
 protected:
   std::unique_ptr<Document> &Doc;
   SMRange SourceRange;
 
-  void operator delete(void *) noexcept = delete;
-
   ~Node() = default;
 
 private:
@@ -268,8 +274,7 @@ class KeyValueNode final : public Node {
 
 public:
   KeyValueNode(std::unique_ptr<Document> &D)
-      : Node(NK_KeyValue, D, StringRef(), StringRef()), Key(nullptr),
-        Value(nullptr) {}
+      : Node(NK_KeyValue, D, StringRef(), StringRef()) {}
 
   /// \brief Parse and return the key.
   ///
@@ -296,8 +301,8 @@ class KeyValueNode final : public Node {
   }
 
 private:
-  Node *Key;
-  Node *Value;
+  Node *Key = nullptr;
+  Node *Value = nullptr;
 };
 
 /// \brief This is an iterator abstraction over YAML collections shared by both
@@ -309,7 +314,7 @@ template <class BaseT, class ValueT>
 class basic_collection_iterator
     : public std::iterator<std::input_iterator_tag, ValueT> {
 public:
-  basic_collection_iterator() : Base(nullptr) {}
+  basic_collection_iterator() = default;
   basic_collection_iterator(BaseT *B) : Base(B) {}
 
   ValueT *operator->() const {
@@ -358,7 +363,7 @@ class basic_collection_iterator
   }
 
 private:
-  BaseT *Base;
+  BaseT *Base = nullptr;
 };
 
 // The following two templates are used for both MappingNode and Sequence Node.
@@ -399,11 +404,12 @@ class MappingNode final : public Node {
 
   MappingNode(std::unique_ptr<Document> &D, StringRef Anchor, StringRef Tag,
               MappingType MT)
-      : Node(NK_Mapping, D, Anchor, Tag), Type(MT), IsAtBeginning(true),
-        IsAtEnd(false), CurrentEntry(nullptr) {}
+      : Node(NK_Mapping, D, Anchor, Tag), Type(MT) {}
 
   friend class basic_collection_iterator<MappingNode, KeyValueNode>;
-  typedef basic_collection_iterator<MappingNode, KeyValueNode> iterator;
+
+  using iterator = basic_collection_iterator<MappingNode, KeyValueNode>;
+
   template <class T> friend typename T::iterator yaml::begin(T &);
   template <class T> friend void yaml::skip(T &);
 
@@ -419,9 +425,9 @@ class MappingNode final : public Node {
 
 private:
   MappingType Type;
-  bool IsAtBeginning;
-  bool IsAtEnd;
-  KeyValueNode *CurrentEntry;
+  bool IsAtBeginning = true;
+  bool IsAtEnd = false;
+  KeyValueNode *CurrentEntry = nullptr;
 
   void increment();
 };
@@ -453,13 +459,12 @@ class SequenceNode final : public Node {
 
   SequenceNode(std::unique_ptr<Document> &D, StringRef Anchor, StringRef Tag,
                SequenceType ST)
-      : Node(NK_Sequence, D, Anchor, Tag), SeqType(ST), IsAtBeginning(true),
-        IsAtEnd(false),
-        WasPreviousTokenFlowEntry(true), // Start with an imaginary ','.
-        CurrentEntry(nullptr) {}
+      : Node(NK_Sequence, D, Anchor, Tag), SeqType(ST) {}
 
   friend class basic_collection_iterator<SequenceNode, Node>;
-  typedef basic_collection_iterator<SequenceNode, Node> iterator;
+
+  using iterator = basic_collection_iterator<SequenceNode, Node>;
+
   template <class T> friend typename T::iterator yaml::begin(T &);
   template <class T> friend void yaml::skip(T &);
 
@@ -477,10 +482,10 @@ class SequenceNode final : public Node {
 
 private:
   SequenceType SeqType;
-  bool IsAtBeginning;
-  bool IsAtEnd;
-  bool WasPreviousTokenFlowEntry;
-  Node *CurrentEntry;
+  bool IsAtBeginning = true;
+  bool IsAtEnd = false;
+  bool WasPreviousTokenFlowEntry = true; // Start with an imaginary ','.
+  Node *CurrentEntry = nullptr;
 };
 
 /// \brief Represents an alias to a Node with an anchor.
@@ -507,11 +512,11 @@ class AliasNode final : public Node {
 ///        node.
 class Document {
 public:
+  Document(Stream &ParentStream);
+
   /// \brief Root for parsing a node. Returns a single node.
   Node *parseBlockNode();
 
-  Document(Stream &ParentStream);
-
   /// \brief Finish parsing the current document and return true if there are
   ///        more. Return false otherwise.
   bool skip();
@@ -564,7 +569,7 @@ class Document {
 /// \brief Iterator abstraction for Documents over a Stream.
 class document_iterator {
 public:
-  document_iterator() : Doc(nullptr) {}
+  document_iterator() = default;
   document_iterator(std::unique_ptr<Document> &D) : Doc(&D) {}
 
   bool operator==(const document_iterator &Other) {
@@ -593,11 +598,11 @@ class document_iterator {
 private:
   bool isAtEnd() const { return !Doc || !*Doc; }
 
-  std::unique_ptr<Document> *Doc;
+  std::unique_ptr<Document> *Doc = nullptr;
 };
 
-} // End namespace yaml.
+} // end namespace yaml
 
-} // End namespace llvm.
+} // end namespace llvm
 
-#endif
+#endif // LLVM_SUPPORT_YAMLPARSER_H
diff --git a/llvm/include/llvm/Support/YAMLTraits.h b/llvm/include/llvm/Support/YAMLTraits.h
diff --git a/llvm/lib/ProfileData/Coverage/CoverageMapping.cpp b/llvm/lib/ProfileData/Coverage/CoverageMapping.cpp
@@ -1,4 +1,4 @@
-//===- CoverageMapping.cpp - Code coverage mapping support ------*- C++ -*-===//
+//===- CoverageMapping.cpp - Code coverage mapping support ----------------===//
 //
 //                     The LLVM Compiler Infrastructure
 //
@@ -303,8 +303,8 @@ namespace {
 /// An instantiation set is a collection of functions that have the same source
 /// code, ie, template functions specializations.
 class FunctionInstantiationSetCollector {
-  typedef DenseMap<std::pair<unsigned, unsigned>,
-                   std::vector<const FunctionRecord *>> MapT;
+  using MapT = DenseMap<std::pair<unsigned, unsigned>,
+                        std::vector<const FunctionRecord *>>;
   MapT InstantiatedFunctions;
 
 public:
@@ -318,7 +318,6 @@ class FunctionInstantiationSetCollector {
   }
 
   MapT::iterator begin() { return InstantiatedFunctions.begin(); }
-
   MapT::iterator end() { return InstantiatedFunctions.end(); }
 };
 

diff --git a/llvm/lib/ProfileData/Coverage/CoverageMappingReader.cpp b/llvm/lib/ProfileData/Coverage/CoverageMappingReader.cpp
@@ -1,4 +1,4 @@
-//===- CoverageMappingReader.cpp - Code coverage mapping reader -*- C++ -*-===//
+//===- CoverageMappingReader.cpp - Code coverage mapping reader -----------===//
 //
 //                     The LLVM Compiler Infrastructure
 //
@@ -62,7 +62,7 @@ void CoverageMappingIterator::increment() {
 }
 
 Error RawCoverageReader::readULEB128(uint64_t &Result) {
-  if (Data.size() < 1)
+  if (Data.empty())
     return make_error<CoverageMapError>(coveragemap_error::truncated);
   unsigned N = 0;
   Result = decodeULEB128(reinterpret_cast<const uint8_t *>(Data.data()), &N);
@@ -392,9 +392,9 @@ struct CovMapFuncRecordReader {
 // A class for reading coverage mapping function records for a module.
 template <CovMapVersion Version, class IntPtrT, support::endianness Endian>
 class VersionedCovMapFuncRecordReader : public CovMapFuncRecordReader {
-  typedef typename CovMapTraits<
-      Version, IntPtrT>::CovMapFuncRecordType FuncRecordType;
-  typedef typename CovMapTraits<Version, IntPtrT>::NameRefType  NameRefType;
+  using FuncRecordType =
+      typename CovMapTraits<Version, IntPtrT>::CovMapFuncRecordType;
+  using NameRefType = typename CovMapTraits<Version, IntPtrT>::NameRefType;
 
   // Maps function's name references to the indexes of their records
   // in \c Records.
@@ -576,15 +576,15 @@ static Error loadTestingFormat(StringRef Data, InstrProfSymtab &ProfileNames,
   Endian = support::endianness::little;
 
   Data = Data.substr(StringRef(TestingFormatMagic).size());
-  if (Data.size() < 1)
+  if (Data.empty())
     return make_error<CoverageMapError>(coveragemap_error::truncated);
   unsigned N = 0;
   auto ProfileNamesSize =
       decodeULEB128(reinterpret_cast<const uint8_t *>(Data.data()), &N);
   if (N > Data.size())
     return make_error<CoverageMapError>(coveragemap_error::malformed);
   Data = Data.substr(N);
-  if (Data.size() < 1)
+  if (Data.empty())
     return make_error<CoverageMapError>(coveragemap_error::truncated);
   N = 0;
   uint64_t Address =
@@ -598,7 +598,7 @@ static Error loadTestingFormat(StringRef Data, InstrProfSymtab &ProfileNames,
     return E;
   CoverageMapping = Data.substr(ProfileNamesSize);
   // Skip the padding bytes because coverage map data has an alignment of 8.
-  if (CoverageMapping.size() < 1)
+  if (CoverageMapping.empty())
     return make_error<CoverageMapError>(coveragemap_error::truncated);
   size_t Pad = alignmentAdjustment(CoverageMapping.data(), 8);
   if (CoverageMapping.size() < Pad)

diff --git a/llvm/lib/ProfileData/InstrProfReader.cpp b/llvm/lib/ProfileData/InstrProfReader.cpp
@@ -484,8 +484,8 @@ InstrProfLookupTrait::ComputeHash(StringRef K) {
   return IndexedInstrProf::ComputeHash(HashType, K);
 }
 
-typedef InstrProfLookupTrait::data_type data_type;
-typedef InstrProfLookupTrait::offset_type offset_type;
+using data_type = InstrProfLookupTrait::data_type;
+using offset_type = InstrProfLookupTrait::offset_type;
 
 bool InstrProfLookupTrait::readValueProfilingData(
     const unsigned char *&D, const unsigned char *const End) {
@@ -622,7 +622,7 @@ IndexedInstrProfReader::readSummary(IndexedInstrProf::ProfVersion Version,
     for (unsigned I = 0; I < SummarySize / sizeof(uint64_t); I++)
       Dst[I] = endian::byte_swap<uint64_t, little>(Src[I]);
 
-    llvm::SummaryEntryVector DetailedSummary;
+    SummaryEntryVector DetailedSummary;
     for (unsigned I = 0; I < SummaryData->NumCutoffEntries; I++) {
       const IndexedInstrProf::Summary::Entry &Ent = SummaryData->getEntry(I);
       DetailedSummary.emplace_back((uint32_t)Ent.Cutoff, Ent.MinBlockCount,

diff --git a/llvm/lib/ProfileData/InstrProfWriter.cpp b/llvm/lib/ProfileData/InstrProfWriter.cpp
@@ -69,8 +69,7 @@ class ProfOStream {
           write(P[K].D[I]);
       }
     } else {
-      raw_string_ostream &SOStream =
-          static_cast<llvm::raw_string_ostream &>(OS);
+      raw_string_ostream &SOStream = static_cast<raw_string_ostream &>(OS);
       std::string &Data = SOStream.str(); // with flush
       for (int K = 0; K < NItems; K++) {
         for (int I = 0; I < P[K].N; I++) {
@@ -91,14 +90,14 @@ class ProfOStream {
 
 class InstrProfRecordWriterTrait {
 public:
-  typedef StringRef key_type;
-  typedef StringRef key_type_ref;
+  using key_type = StringRef;
+  using key_type_ref = StringRef;
 
-  typedef const InstrProfWriter::ProfilingData *const data_type;
-  typedef const InstrProfWriter::ProfilingData *const data_type_ref;
+  using data_type = const InstrProfWriter::ProfilingData *const;
+  using data_type_ref = const InstrProfWriter::ProfilingData *const;
 
-  typedef uint64_t hash_value_type;
-  typedef uint64_t offset_type;
+  using hash_value_type = uint64_t;
+  using offset_type = uint64_t;
 
   support::endianness ValueProfDataEndianness = support::little;
   InstrProfSummaryBuilder *SummaryBuilder;

diff --git a/llvm/lib/Support/GraphWriter.cpp b/llvm/lib/Support/GraphWriter.cpp
@@ -1,4 +1,4 @@
-//===-- GraphWriter.cpp - Implements GraphWriter support routines ---------===//
+//===- GraphWriter.cpp - Implements GraphWriter support routines ----------===//
 //
 //                     The LLVM Compiler Infrastructure
 //
@@ -12,10 +12,22 @@
 //===----------------------------------------------------------------------===//
 
 #include "llvm/Support/GraphWriter.h"
+#include "llvm/ADT/SmallString.h"
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/ADT/StringRef.h"
 #include "llvm/Config/config.h"
 #include "llvm/Support/CommandLine.h"
+#include "llvm/Support/Compiler.h"
+#include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/ErrorOr.h"
 #include "llvm/Support/FileSystem.h"
 #include "llvm/Support/Program.h"
+#include "llvm/Support/raw_ostream.h"
+#include <cassert>
+#include <system_error>
+#include <string>
+#include <vector>
+
 using namespace llvm;
 
 static cl::opt<bool> ViewBackground("view-background", cl::Hidden,
@@ -99,8 +111,10 @@ static bool ExecGraphViewer(StringRef ExecPath, std::vector<const char *> &args,
 }
 
 namespace {
+
 struct GraphSession {
   std::string LogBuffer;
+
   bool TryFindProgram(StringRef Names, std::string &ProgramPath) {
     raw_string_ostream Log(LogBuffer);
     SmallVector<StringRef, 8> parts;
@@ -115,7 +129,8 @@ struct GraphSession {
     return false;
   }
 };
-} // namespace
+
+} // end anonymous namespace
 
 static const char *getProgramName(GraphProgram::Name program) {
   switch (program) {

diff --git a/llvm/lib/Support/YAMLParser.cpp b/llvm/lib/Support/YAMLParser.cpp
@@ -1,4 +1,4 @@
-//===--- YAMLParser.cpp - Simple YAML parser ------------------------------===//
+//===- YAMLParser.cpp - Simple YAML parser --------------------------------===//
 //
 //                     The LLVM Compiler Infrastructure
 //
@@ -13,15 +13,29 @@
 
 #include "llvm/Support/YAMLParser.h"
 #include "llvm/ADT/AllocatorList.h"
+#include "llvm/ADT/ArrayRef.h"
+#include "llvm/ADT/None.h"
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/SmallString.h"
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/ADT/StringExtras.h"
+#include "llvm/ADT/StringRef.h"
 #include "llvm/ADT/Twine.h"
+#include "llvm/Support/Compiler.h"
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/MemoryBuffer.h"
+#include "llvm/Support/SMLoc.h"
 #include "llvm/Support/SourceMgr.h"
 #include "llvm/Support/raw_ostream.h"
+#include <algorithm>
+#include <cassert>
+#include <cstddef>
+#include <cstdint>
+#include <map>
+#include <memory>
+#include <string>
+#include <system_error>
+#include <utility>
 
 using namespace llvm;
 using namespace yaml;
@@ -37,7 +51,7 @@ enum UnicodeEncodingForm {
 
 /// EncodingInfo - Holds the encoding type and length of the byte order mark if
 ///                it exists. Length is in {0, 2, 3, 4}.
-typedef std::pair<UnicodeEncodingForm, unsigned> EncodingInfo;
+using EncodingInfo = std::pair<UnicodeEncodingForm, unsigned>;
 
 /// getUnicodeEncoding - Reads up to the first 4 bytes to determine the Unicode
 ///                      encoding form of \a Input.
@@ -46,7 +60,7 @@ typedef std::pair<UnicodeEncodingForm, unsigned> EncodingInfo;
 /// @returns An EncodingInfo indicating the Unicode encoding form of the input
 ///          and how long the byte order mark is if one exists.
 static EncodingInfo getUnicodeEncoding(StringRef Input) {
-  if (Input.size() == 0)
+  if (Input.empty())
     return std::make_pair(UEF_Unknown, 0);
 
   switch (uint8_t(Input[0])) {
@@ -95,8 +109,6 @@ static EncodingInfo getUnicodeEncoding(StringRef Input) {
   return std::make_pair(UEF_UTF8, 0);
 }
 
-namespace llvm {
-namespace yaml {
 /// Pin the vtables to this file.
 void Node::anchor() {}
 void NullNode::anchor() {}
@@ -107,6 +119,9 @@ void MappingNode::anchor() {}
 void SequenceNode::anchor() {}
 void AliasNode::anchor() {}
 
+namespace llvm {
+namespace yaml {
+
 /// Token - A single YAML token.
 struct Token {
   enum TokenKind {
@@ -133,7 +148,7 @@ struct Token {
     TK_Alias,
     TK_Anchor,
     TK_Tag
-  } Kind;
+  } Kind = TK_Error;
 
   /// A string of length 0 or more whose begin() points to the logical location
   /// of the token in the input.
@@ -142,14 +157,16 @@ struct Token {
   /// The value of a block scalar node.
   std::string Value;
 
-  Token() : Kind(TK_Error) {}
+  Token() = default;
 };
-}
-}
 
-typedef llvm::BumpPtrList<Token> TokenQueueT;
+} // end namespace yaml
+} // end namespace llvm
+
+using TokenQueueT = BumpPtrList<Token>;
 
 namespace {
+
 /// @brief This struct is used to track simple keys.
 ///
 /// Simple keys are handled by creating an entry in SimpleKeys for each Token
@@ -170,12 +187,13 @@ struct SimpleKey {
     return Tok == Other.Tok;
   }
 };
-}
+
+} // end anonymous namespace
 
 /// @brief The Unicode scalar value of a UTF-8 minimal well-formed code unit
 ///        subsequence and the subsequence's length in code units (uint8_t).
 ///        A length of 0 represents an error.
-typedef std::pair<uint32_t, unsigned> UTF8Decoded;
+using UTF8Decoded = std::pair<uint32_t, unsigned>;
 
 static UTF8Decoded decodeUTF8(StringRef Range) {
   StringRef::iterator Position= Range.begin();
@@ -229,6 +247,7 @@ static UTF8Decoded decodeUTF8(StringRef Range) {
 
 namespace llvm {
 namespace yaml {
+
 /// @brief Scans YAML tokens from a MemoryBuffer.
 class Scanner {
 public:
@@ -350,7 +369,8 @@ class Scanner {
   ///          ns-char.
   StringRef::iterator skip_ns_char(StringRef::iterator Position);
 
-  typedef StringRef::iterator (Scanner::*SkipWhileFunc)(StringRef::iterator);
+  using SkipWhileFunc = StringRef::iterator (Scanner::*)(StringRef::iterator);
+
   /// @brief Skip minimal well-formed code unit subsequences until Func
   ///        returns its input.
   ///
@@ -655,10 +675,10 @@ bool yaml::dumpTokens(StringRef Input, raw_ostream &OS) {
 }
 
 bool yaml::scanTokens(StringRef Input) {
-  llvm::SourceMgr SM;
-  llvm::yaml::Scanner scanner(Input, SM);
-  for (;;) {
-    llvm::yaml::Token T = scanner.getNext();
+  SourceMgr SM;
+  Scanner scanner(Input, SM);
+  while (true) {
+    Token T = scanner.getNext();
     if (T.Kind == Token::TK_StreamEnd)
       break;
     else if (T.Kind == Token::TK_Error)
@@ -1744,7 +1764,7 @@ Stream::Stream(MemoryBufferRef InputBuffer, SourceMgr &SM, bool ShowColors,
                std::error_code *EC)
     : scanner(new Scanner(InputBuffer, SM, ShowColors, EC)), CurrentDoc() {}
 
-Stream::~Stream() {}
+Stream::~Stream() = default;
 
 bool Stream::failed() { return scanner->failed(); }
 
@@ -1851,8 +1871,6 @@ bool Node::failed() const {
   return Doc->failed();
 }
 
-
-
 StringRef ScalarNode::getValue(SmallVectorImpl<char> &Storage) const {
   // TODO: Handle newlines properly. We need to remove leading whitespace.
   if (Value[0] == '"') { // Double quoted.

diff --git a/llvm/lib/Support/YAMLTraits.cpp b/llvm/lib/Support/YAMLTraits.cpp
@@ -8,29 +8,36 @@
 //===----------------------------------------------------------------------===//
 
 #include "llvm/Support/YAMLTraits.h"
+#include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/SmallString.h"
+#include "llvm/ADT/StringRef.h"
 #include "llvm/ADT/Twine.h"
 #include "llvm/Support/Casting.h"
 #include "llvm/Support/Errc.h"
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/Format.h"
 #include "llvm/Support/LineIterator.h"
+#include "llvm/Support/MemoryBuffer.h"
 #include "llvm/Support/YAMLParser.h"
 #include "llvm/Support/raw_ostream.h"
-#include <cctype>
+#include <algorithm>
+#include <cassert>
+#include <cstdint>
+#include <cstdlib>
 #include <cstring>
+#include <string>
+#include <vector>
+
 using namespace llvm;
 using namespace yaml;
 
 //===----------------------------------------------------------------------===//
 //  IO
 //===----------------------------------------------------------------------===//
 
-IO::IO(void *Context) : Ctxt(Context) {
-}
+IO::IO(void *Context) : Ctxt(Context) {}
 
-IO::~IO() {
-}
+IO::~IO() = default;
 
 void *IO::getContext() {
   return Ctxt;
@@ -46,15 +53,13 @@ void IO::setContext(void *Context) {
 
 Input::Input(StringRef InputContent, void *Ctxt,
              SourceMgr::DiagHandlerTy DiagHandler, void *DiagHandlerCtxt)
-    : IO(Ctxt), Strm(new Stream(InputContent, SrcMgr, false, &EC)),
-      CurrentNode(nullptr) {
+    : IO(Ctxt), Strm(new Stream(InputContent, SrcMgr, false, &EC)) {
   if (DiagHandler)
     SrcMgr.setDiagHandler(DiagHandler, DiagHandlerCtxt);
   DocIterator = Strm->begin();
 }
 
-Input::~Input() {
-}
+Input::~Input() = default;
 
 std::error_code Input::error() { return EC; }
 
@@ -398,13 +403,9 @@ bool Input::canElideEmptySequence() {
 //===----------------------------------------------------------------------===//
 
 Output::Output(raw_ostream &yout, void *context, int WrapColumn)
-    : IO(context), Out(yout), WrapColumn(WrapColumn), Column(0),
-      ColumnAtFlowStart(0), ColumnAtMapFlowStart(0), NeedBitValueComma(false),
-      NeedFlowSequenceComma(false), EnumerationMatchFound(false),
-      NeedsNewLine(false), WriteDefaultValues(false) {}
+    : IO(context), Out(yout), WrapColumn(WrapColumn) {}
 
-Output::~Output() {
-}
+Output::~Output() = default;
 
 bool Output::outputting() {
   return true;