vendor/llvm-project/llvmorg-11-init-20887-g2e10b7a39b9vendor/llvm-project/master

10 files changed, 2332 insertions, 1006 deletions

diff --git a/clang/lib/Serialization/ASTCommon.cpp b/clang/lib/Serialization/ASTCommon.cpp
index cdb5b17022c2..bf583b02f96b 100644
--- a/clang/lib/Serialization/ASTCommon.cpp
+++ b/clang/lib/Serialization/ASTCommon.cpp
@@ -240,9 +240,21 @@ serialization::TypeIdxFromBuiltin(const BuiltinType *BT) {
   case BuiltinType::BuiltinFn:
     ID = PREDEF_TYPE_BUILTIN_FN;
     break;
+  case BuiltinType::IncompleteMatrixIdx:
+    ID = PREDEF_TYPE_INCOMPLETE_MATRIX_IDX;
+    break;
   case BuiltinType::OMPArraySection:
     ID = PREDEF_TYPE_OMP_ARRAY_SECTION;
     break;
+  case BuiltinType::OMPArrayShaping:
+    ID = PREDEF_TYPE_OMP_ARRAY_SHAPING;
+    break;
+  case BuiltinType::OMPIterator:
+    ID = PREDEF_TYPE_OMP_ITERATOR;
+    break;
+  case BuiltinType::BFloat16:
+    ID = PREDEF_TYPE_BFLOAT16_ID;
+    break;
   }
 
   return TypeIdx(ID);
@@ -365,6 +377,7 @@ bool serialization::isRedeclarableDeclKind(unsigned Kind) {
   case Decl::IndirectField:
   case Decl::Field:
   case Decl::MSProperty:
+  case Decl::MSGuid:
   case Decl::ObjCIvar:
   case Decl::ObjCAtDefsField:
   case Decl::NonTypeTemplateParm:
@@ -402,6 +415,7 @@ bool serialization::isRedeclarableDeclKind(unsigned Kind) {
   case Decl::Binding:
   case Decl::Concept:
   case Decl::LifetimeExtendedTemporary:
+  case Decl::RequiresExprBody:
     return false;
 
   // These indirectly derive from Redeclarable<T> but are not actually
diff --git a/clang/lib/Serialization/ASTReader.cpp b/clang/lib/Serialization/ASTReader.cpp
index 19e7ebe03a1f..4a1a995204e5 100644
--- a/clang/lib/Serialization/ASTReader.cpp
+++ b/clang/lib/Serialization/ASTReader.cpp
@@ -89,6 +89,7 @@
 #include "llvm/ADT/APSInt.h"
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/ADT/DenseMap.h"
+#include "llvm/ADT/FloatingPointMode.h"
 #include "llvm/ADT/FoldingSet.h"
 #include "llvm/ADT/Hashing.h"
 #include "llvm/ADT/IntrusiveRefCntPtr.h"
@@ -139,6 +140,7 @@ using namespace clang;
 using namespace clang::serialization;
 using namespace clang::serialization::reader;
 using llvm::BitstreamCursor;
+using llvm::RoundingMode;
 
 //===----------------------------------------------------------------------===//
 // ChainedASTReaderListener implementation
@@ -1334,6 +1336,7 @@ bool ASTReader::ReadSourceManagerBlock(ModuleFile &F) {
     Error(std::move(Err));
     return true;
   }
+  F.SourceManagerBlockStartOffset = SLocEntryCursor.GetCurrentBitNo();
 
   RecordData Record;
   while (true) {
@@ -1411,7 +1414,7 @@ resolveFileRelativeToOriginalDir(const std::string &Filename,
     path::append(currPCHPath, "..");
   path::append(currPCHPath, fileDirI, fileDirE);
   path::append(currPCHPath, path::filename(Filename));
-  return currPCHPath.str();
+  return std::string(currPCHPath.str());
 }
 
 bool ASTReader::ReadSLocEntry(int ID) {
@@ -1468,6 +1471,7 @@ bool ASTReader::ReadSLocEntry(int ID) {
 
   ModuleFile *F = GlobalSLocEntryMap.find(-ID)->second;
   if (llvm::Error Err = F->SLocEntryCursor.JumpToBit(
+          F->SLocEntryOffsetsBase +
           F->SLocEntryOffsets[ID - F->SLocEntryBaseID])) {
     Error(std::move(Err));
     return true;
@@ -1625,13 +1629,17 @@ SourceLocation ASTReader::getImportLocation(ModuleFile *F) {
 /// Enter a subblock of the specified BlockID with the specified cursor. Read
 /// the abbreviations that are at the top of the block and then leave the cursor
 /// pointing into the block.
-bool ASTReader::ReadBlockAbbrevs(BitstreamCursor &Cursor, unsigned BlockID) {
+bool ASTReader::ReadBlockAbbrevs(BitstreamCursor &Cursor, unsigned BlockID,
+                                 uint64_t *StartOfBlockOffset) {
   if (llvm::Error Err = Cursor.EnterSubBlock(BlockID)) {
     // FIXME this drops errors on the floor.
     consumeError(std::move(Err));
     return true;
   }
 
+  if (StartOfBlockOffset)
+    *StartOfBlockOffset = Cursor.GetCurrentBitNo();
+
   while (true) {
     uint64_t Offset = Cursor.GetCurrentBitNo();
     Expected<unsigned> MaybeCode = Cursor.ReadCode();
@@ -1838,7 +1846,7 @@ bool HeaderFileInfoTrait::EqualKey(internal_key_ref a, internal_key_ref b) {
       return nullptr;
     }
 
-    std::string Resolved = Key.Filename;
+    std::string Resolved = std::string(Key.Filename);
     Reader.ResolveImportedPath(M, Resolved);
     if (auto File = FileMgr.getFile(Resolved))
       return *File;
@@ -1913,13 +1921,13 @@ HeaderFileInfoTrait::ReadData(internal_key_ref key, const unsigned char *d,
     ModuleMap &ModMap =
         Reader.getPreprocessor().getHeaderSearchInfo().getModuleMap();
 
-    std::string Filename = key.Filename;
+    std::string Filename = std::string(key.Filename);
     if (key.Imported)
       Reader.ResolveImportedPath(M, Filename);
     // FIXME: This is not always the right filename-as-written, but we're not
     // going to use this information to rebuild the module, so it doesn't make
     // a lot of difference.
-    Module::Header H = { key.Filename, *FileMgr.getFile(Filename) };
+    Module::Header H = {std::string(key.Filename), *FileMgr.getFile(Filename)};
     ModMap.addHeader(Mod, H, HeaderRole, /*Imported*/true);
     HFI.isModuleHeader |= !(HeaderRole & ModuleMap::TextualHeader);
   }
@@ -1930,9 +1938,8 @@ HeaderFileInfoTrait::ReadData(internal_key_ref key, const unsigned char *d,
   return HFI;
 }
 
-void ASTReader::addPendingMacro(IdentifierInfo *II,
-                                ModuleFile *M,
-                                uint64_t MacroDirectivesOffset) {
+void ASTReader::addPendingMacro(IdentifierInfo *II, ModuleFile *M,
+                                uint32_t MacroDirectivesOffset) {
   assert(NumCurrentElementsDeserializing > 0 &&"Missing deserialization guard");
   PendingMacroIDs[II].push_back(PendingMacroInfo(M, MacroDirectivesOffset));
 }
@@ -2097,7 +2104,8 @@ void ASTReader::resolvePendingMacro(IdentifierInfo *II,
 
   BitstreamCursor &Cursor = M.MacroCursor;
   SavedStreamPosition SavedPosition(Cursor);
-  if (llvm::Error Err = Cursor.JumpToBit(PMInfo.MacroDirectivesOffset)) {
+  if (llvm::Error Err =
+          Cursor.JumpToBit(M.MacroOffsetsBase + PMInfo.MacroDirectivesOffset)) {
     Error(std::move(Err));
     return;
   }
@@ -2248,7 +2256,7 @@ ASTReader::readInputFileInfo(ModuleFile &F, unsigned ID) {
   R.Overridden = static_cast<bool>(Record[3]);
   R.Transient = static_cast<bool>(Record[4]);
   R.TopLevelModuleMap = static_cast<bool>(Record[5]);
-  R.Filename = Blob;
+  R.Filename = std::string(Blob);
   ResolveImportedPath(F, R.Filename);
 
   Expected<llvm::BitstreamEntry> MaybeEntry = Cursor.advance();
@@ -2309,7 +2317,7 @@ InputFile ASTReader::getInputFile(ModuleFile &F, unsigned ID, bool Complain) {
   if (File == nullptr && !F.OriginalDir.empty() && !F.BaseDirectory.empty() &&
       F.OriginalDir != F.BaseDirectory) {
     std::string Resolved = resolveFileRelativeToOriginalDir(
-        Filename, F.OriginalDir, F.BaseDirectory);
+        std::string(Filename), F.OriginalDir, F.BaseDirectory);
     if (!Resolved.empty())
       if (auto FE = FileMgr.getFile(Resolved))
         File = *FE;
@@ -2788,10 +2796,10 @@ ASTReader::ReadControlBlock(ModuleFile &F,
             ReadUntranslatedSourceLocation(Record[Idx++]);
         off_t StoredSize = (off_t)Record[Idx++];
         time_t StoredModTime = (time_t)Record[Idx++];
-        ASTFileSignature StoredSignature = {
-            {{(uint32_t)Record[Idx++], (uint32_t)Record[Idx++],
-              (uint32_t)Record[Idx++], (uint32_t)Record[Idx++],
-              (uint32_t)Record[Idx++]}}};
+        auto FirstSignatureByte = Record.begin() + Idx;
+        ASTFileSignature StoredSignature = ASTFileSignature::create(
+            FirstSignatureByte, FirstSignatureByte + ASTFileSignature::size);
+        Idx += ASTFileSignature::size;
 
         std::string ImportedName = ReadString(Record, Idx);
         std::string ImportedFile;
@@ -2844,7 +2852,7 @@ ASTReader::ReadControlBlock(ModuleFile &F,
 
     case ORIGINAL_FILE:
       F.OriginalSourceFileID = FileID::get(Record[0]);
-      F.ActualOriginalSourceFileName = Blob;
+      F.ActualOriginalSourceFileName = std::string(Blob);
       F.OriginalSourceFileName = F.ActualOriginalSourceFileName;
       ResolveImportedPath(F, F.OriginalSourceFileName);
       break;
@@ -2854,11 +2862,11 @@ ASTReader::ReadControlBlock(ModuleFile &F,
       break;
 
     case ORIGINAL_PCH_DIR:
-      F.OriginalDir = Blob;
+      F.OriginalDir = std::string(Blob);
       break;
 
     case MODULE_NAME:
-      F.ModuleName = Blob;
+      F.ModuleName = std::string(Blob);
       Diag(diag::remark_module_import)
           << F.ModuleName << F.FileName << (ImportedBy ? true : false)
           << (ImportedBy ? StringRef(ImportedBy->ModuleName) : StringRef());
@@ -2897,9 +2905,9 @@ ASTReader::ReadControlBlock(ModuleFile &F,
             return OutOfDate;
           }
         }
-        F.BaseDirectory = M->Directory->getName();
+        F.BaseDirectory = std::string(M->Directory->getName());
       } else {
-        F.BaseDirectory = Blob;
+        F.BaseDirectory = std::string(Blob);
       }
       break;
     }
@@ -2930,6 +2938,7 @@ ASTReader::ReadASTBlock(ModuleFile &F, unsigned ClientLoadCapabilities) {
     Error(std::move(Err));
     return Failure;
   }
+  F.ASTBlockStartOffset = Stream.GetCurrentBitNo();
 
   // Read all of the records and blocks for the AST file.
   RecordData Record;
@@ -2970,7 +2979,8 @@ ASTReader::ReadASTBlock(ModuleFile &F, unsigned ClientLoadCapabilities) {
           Error(std::move(Err));
           return Failure;
         }
-        if (ReadBlockAbbrevs(F.DeclsCursor, DECLTYPES_BLOCK_ID)) {
+        if (ReadBlockAbbrevs(F.DeclsCursor, DECLTYPES_BLOCK_ID,
+                             &F.DeclsBlockStartOffset)) {
           Error("malformed block record in AST file");
           return Failure;
         }
@@ -3096,7 +3106,7 @@ ASTReader::ReadASTBlock(ModuleFile &F, unsigned ClientLoadCapabilities) {
         Error("duplicate TYPE_OFFSET record in AST file");
         return Failure;
       }
-      F.TypeOffsets = (const uint32_t *)Blob.data();
+      F.TypeOffsets = reinterpret_cast<const UnderalignedInt64 *>(Blob.data());
       F.LocalNumTypes = Record[0];
       unsigned LocalBaseTypeIndex = Record[1];
       F.BaseTypeIndex = getTotalNumTypes();
@@ -3375,6 +3385,7 @@ ASTReader::ReadASTBlock(ModuleFile &F, unsigned ClientLoadCapabilities) {
       F.SLocEntryOffsets = (const uint32_t *)Blob.data();
       F.LocalNumSLocEntries = Record[0];
       unsigned SLocSpaceSize = Record[1];
+      F.SLocEntryOffsetsBase = Record[2] + F.SourceManagerBlockStartOffset;
       std::tie(F.SLocEntryBaseID, F.SLocEntryBaseOffset) =
           SourceMgr.AllocateLoadedSLocEntries(F.LocalNumSLocEntries,
                                               SLocSpaceSize);
@@ -3693,6 +3704,7 @@ ASTReader::ReadASTBlock(ModuleFile &F, unsigned ClientLoadCapabilities) {
       F.MacroOffsets = (const uint32_t *)Blob.data();
       F.LocalNumMacros = Record[0];
       unsigned LocalBaseMacroID = Record[1];
+      F.MacroOffsetsBase = Record[2] + F.ASTBlockStartOffset;
       F.BaseMacroID = getTotalNumMacros();
 
       if (F.LocalNumMacros > 0) {
@@ -3774,6 +3786,34 @@ ASTReader::ReadASTBlock(ModuleFile &F, unsigned ClientLoadCapabilities) {
       }
       break;
     }
+
+    case FLOAT_CONTROL_PRAGMA_OPTIONS: {
+      if (Record.size() < 3) {
+        Error("invalid pragma pack record");
+        return Failure;
+      }
+      FpPragmaCurrentValue = Record[0];
+      FpPragmaCurrentLocation = ReadSourceLocation(F, Record[1]);
+      unsigned NumStackEntries = Record[2];
+      unsigned Idx = 3;
+      // Reset the stack when importing a new module.
+      FpPragmaStack.clear();
+      for (unsigned I = 0; I < NumStackEntries; ++I) {
+        FpPragmaStackEntry Entry;
+        Entry.Value = Record[Idx++];
+        Entry.Location = ReadSourceLocation(F, Record[Idx++]);
+        Entry.PushLocation = ReadSourceLocation(F, Record[Idx++]);
+        FpPragmaStrings.push_back(ReadString(Record, Idx));
+        Entry.SlotLabel = FpPragmaStrings.back();
+        FpPragmaStack.push_back(Entry);
+      }
+      break;
+    }
+
+    case DECLS_TO_CHECK_FOR_DEFERRED_DIAGS:
+      for (unsigned I = 0, N = Record.size(); I != N; ++I)
+        DeclsToCheckForDeferredDiags.push_back(getGlobalDeclID(F, Record[I]));
+      break;
     }
   }
 }
@@ -3805,21 +3845,22 @@ void ASTReader::ReadModuleOffsetMap(ModuleFile &F) const {
 
   while (Data < DataEnd) {
     // FIXME: Looking up dependency modules by filename is horrible. Let's
-    // start fixing this with prebuilt and explicit modules and see how it
-    // goes...
+    // start fixing this with prebuilt, explicit and implicit modules and see
+    // how it goes...
     using namespace llvm::support;
     ModuleKind Kind = static_cast<ModuleKind>(
       endian::readNext<uint8_t, little, unaligned>(Data));
     uint16_t Len = endian::readNext<uint16_t, little, unaligned>(Data);
     StringRef Name = StringRef((const char*)Data, Len);
     Data += Len;
-    ModuleFile *OM = (Kind == MK_PrebuiltModule || Kind == MK_ExplicitModule
-                      ? ModuleMgr.lookupByModuleName(Name)
-                      : ModuleMgr.lookupByFileName(Name));
+    ModuleFile *OM = (Kind == MK_PrebuiltModule || Kind == MK_ExplicitModule ||
+                              Kind == MK_ImplicitModule
+                          ? ModuleMgr.lookupByModuleName(Name)
+                          : ModuleMgr.lookupByFileName(Name));
     if (!OM) {
       std::string Msg =
           "SourceLocation remap refers to unknown module, cannot find ";
-      Msg.append(Name);
+      Msg.append(std::string(Name));
       Error(Msg);
       return;
     }
@@ -3998,7 +4039,7 @@ static void moveMethodToBackOfGlobalList(Sema &S, ObjCMethodDecl *Method) {
 void ASTReader::makeNamesVisible(const HiddenNames &Names, Module *Owner) {
   assert(Owner->NameVisibility != Module::Hidden && "nothing to make visible?");
   for (Decl *D : Names) {
-    bool wasHidden = D->isHidden();
+    bool wasHidden = !D->isUnconditionallyVisible();
     D->setVisibleDespiteOwningModule();
 
     if (wasHidden && SemaObj) {
@@ -4024,8 +4065,8 @@ void ASTReader::makeModuleVisible(Module *Mod,
       continue;
     }
 
-    if (!Mod->isAvailable()) {
-      // Modules that aren't available cannot be made visible.
+    if (Mod->isUnimportable()) {
+      // Modules that aren't importable cannot be made visible.
       continue;
     }
 
@@ -4060,9 +4101,9 @@ void ASTReader::makeModuleVisible(Module *Mod,
 /// visible.
 void ASTReader::mergeDefinitionVisibility(NamedDecl *Def,
                                           NamedDecl *MergedDef) {
-  if (Def->isHidden()) {
+  if (!Def->isUnconditionallyVisible()) {
     // If MergedDef is visible or becomes visible, make the definition visible.
-    if (!MergedDef->isHidden())
+    if (MergedDef->isUnconditionallyVisible())
       Def->setVisibleDespiteOwningModule();
     else {
       getContext().mergeDefinitionIntoModule(
@@ -4702,7 +4743,12 @@ ASTReader::ASTReadResult ASTReader::readUnhashedControlBlockImpl(
     switch ((UnhashedControlBlockRecordTypes)MaybeRecordType.get()) {
     case SIGNATURE:
       if (F)
-        std::copy(Record.begin(), Record.end(), F->Signature.data());
+        F->Signature = ASTFileSignature::create(Record.begin(), Record.end());
+      break;
+    case AST_BLOCK_HASH:
+      if (F)
+        F->ASTBlockHash =
+            ASTFileSignature::create(Record.begin(), Record.end());
       break;
     case DIAGNOSTIC_OPTIONS: {
       bool Complain = (ClientLoadCapabilities & ARR_OutOfDate) == 0;
@@ -4991,8 +5037,8 @@ static ASTFileSignature readASTFileSignature(StringRef PCH) {
       return ASTFileSignature();
     }
     if (SIGNATURE == MaybeRecord.get())
-      return {{{(uint32_t)Record[0], (uint32_t)Record[1], (uint32_t)Record[2],
-                (uint32_t)Record[3], (uint32_t)Record[4]}}};
+      return ASTFileSignature::create(Record.begin(),
+                                      Record.begin() + ASTFileSignature::size);
   }
 }
 
@@ -5071,13 +5117,11 @@ namespace {
     SimplePCHValidator(const LangOptions &ExistingLangOpts,
                        const TargetOptions &ExistingTargetOpts,
                        const PreprocessorOptions &ExistingPPOpts,
-                       StringRef ExistingModuleCachePath,
-                       FileManager &FileMgr)
-      : ExistingLangOpts(ExistingLangOpts),
-        ExistingTargetOpts(ExistingTargetOpts),
-        ExistingPPOpts(ExistingPPOpts),
-        ExistingModuleCachePath(ExistingModuleCachePath),
-        FileMgr(FileMgr) {}
+                       StringRef ExistingModuleCachePath, FileManager &FileMgr)
+        : ExistingLangOpts(ExistingLangOpts),
+          ExistingTargetOpts(ExistingTargetOpts),
+          ExistingPPOpts(ExistingPPOpts),
+          ExistingModuleCachePath(ExistingModuleCachePath), FileMgr(FileMgr) {}
 
     bool ReadLanguageOptions(const LangOptions &LangOpts, bool Complain,
                              bool AllowCompatibleDifferences) override {
@@ -5221,7 +5265,7 @@ bool ASTReader::readASTFileControlBlock(
       Listener.ReadModuleName(Blob);
       break;
     case MODULE_DIRECTORY:
-      ModuleDir = Blob;
+      ModuleDir = std::string(Blob);
       break;
     case MODULE_MAP_FILE: {
       unsigned Idx = 0;
@@ -5273,7 +5317,7 @@ bool ASTReader::readASTFileControlBlock(
           break;
         case INPUT_FILE:
           bool Overridden = static_cast<bool>(Record[3]);
-          std::string Filename = Blob;
+          std::string Filename = std::string(Blob);
           ResolveImportedPath(Filename, ModuleDir);
           shouldContinue = Listener.visitInputFile(
               Filename, isSystemFile, Overridden, /*IsExplicitModule*/false);
@@ -5292,7 +5336,9 @@ bool ASTReader::readASTFileControlBlock(
       unsigned Idx = 0, N = Record.size();
       while (Idx < N) {
         // Read information about the AST file.
-        Idx += 1+1+1+1+5; // Kind, ImportLoc, Size, ModTime, Signature
+        Idx +=
+            1 + 1 + 1 + 1 +
+            ASTFileSignature::size; // Kind, ImportLoc, Size, ModTime, Signature
         std::string ModuleName = ReadString(Record, Idx);
         std::string Filename = ReadString(Record, Idx);
         ResolveImportedPath(Filename, ModuleDir);
@@ -5532,14 +5578,14 @@ ASTReader::ReadSubmoduleBlock(ModuleFile &F, unsigned ClientLoadCapabilities) {
       // imported module file.
       CurrentModule->Requirements.clear();
       CurrentModule->MissingHeaders.clear();
-      CurrentModule->IsMissingRequirement =
-          ParentModule && ParentModule->IsMissingRequirement;
-      CurrentModule->IsAvailable = !CurrentModule->IsMissingRequirement;
+      CurrentModule->IsUnimportable =
+          ParentModule && ParentModule->IsUnimportable;
+      CurrentModule->IsAvailable = !CurrentModule->IsUnimportable;
       break;
     }
 
     case SUBMODULE_UMBRELLA_HEADER: {
-      std::string Filename = Blob;
+      std::string Filename = std::string(Blob);
       ResolveImportedPath(F, Filename);
       if (auto Umbrella = PP.getFileManager().getFile(Filename)) {
         if (!CurrentModule->getUmbrellaHeader())
@@ -5572,7 +5618,7 @@ ASTReader::ReadSubmoduleBlock(ModuleFile &F, unsigned ClientLoadCapabilities) {
       break;
 
     case SUBMODULE_UMBRELLA_DIR: {
-      std::string Dirname = Blob;
+      std::string Dirname = std::string(Blob);
       ResolveImportedPath(F, Dirname);
       if (auto Umbrella = PP.getFileManager().getDirectory(Dirname)) {
         if (!CurrentModule->getUmbrellaDir())
@@ -5642,7 +5688,7 @@ ASTReader::ReadSubmoduleBlock(ModuleFile &F, unsigned ClientLoadCapabilities) {
     case SUBMODULE_LINK_LIBRARY:
       ModMap.resolveLinkAsDependencies(CurrentModule);
       CurrentModule->LinkLibraries.push_back(
-                                         Module::LinkLibrary(Blob, Record[0]));
+          Module::LinkLibrary(std::string(Blob), Record[0]));
       break;
 
     case SUBMODULE_CONFIG_MACRO:
@@ -5903,8 +5949,8 @@ PreprocessedEntity *ASTReader::ReadPreprocessedEntity(unsigned Index) {
   }
 
   SavedStreamPosition SavedPosition(M.PreprocessorDetailCursor);
-  if (llvm::Error Err =
-          M.PreprocessorDetailCursor.JumpToBit(PPOffs.BitOffset)) {
+  if (llvm::Error Err = M.PreprocessorDetailCursor.JumpToBit(
+          M.MacroOffsetsBase + PPOffs.BitOffset)) {
     Error(std::move(Err));
     return nullptr;
   }
@@ -6317,7 +6363,9 @@ ASTReader::RecordLocation ASTReader::TypeCursorForIndex(unsigned Index) {
   GlobalTypeMapType::iterator I = GlobalTypeMap.find(Index);
   assert(I != GlobalTypeMap.end() && "Corrupted global type map");
   ModuleFile *M = I->second;
-  return RecordLocation(M, M->TypeOffsets[Index - M->BaseTypeIndex]);
+  return RecordLocation(
+      M, M->TypeOffsets[Index - M->BaseTypeIndex].getBitOffset() +
+             M->DeclsBlockStartOffset);
 }
 
 static llvm::Optional<Type::TypeClass> getTypeClassForCode(TypeCode code) {
@@ -6523,6 +6571,21 @@ void TypeLocReader::VisitExtVectorTypeLoc(ExtVectorTypeLoc TL) {
   TL.setNameLoc(readSourceLocation());
 }
 
+void TypeLocReader::VisitConstantMatrixTypeLoc(ConstantMatrixTypeLoc TL) {
+  TL.setAttrNameLoc(readSourceLocation());
+  TL.setAttrOperandParensRange(Reader.readSourceRange());
+  TL.setAttrRowOperand(Reader.readExpr());
+  TL.setAttrColumnOperand(Reader.readExpr());
+}
+
+void TypeLocReader::VisitDependentSizedMatrixTypeLoc(
+    DependentSizedMatrixTypeLoc TL) {
+  TL.setAttrNameLoc(readSourceLocation());
+  TL.setAttrOperandParensRange(Reader.readSourceRange());
+  TL.setAttrRowOperand(Reader.readExpr());
+  TL.setAttrColumnOperand(Reader.readExpr());
+}
+
 void TypeLocReader::VisitFunctionTypeLoc(FunctionTypeLoc TL) {
   TL.setLocalRangeBegin(readSourceLocation());
   TL.setLParenLoc(readSourceLocation());
@@ -6576,6 +6639,17 @@ void TypeLocReader::VisitUnaryTransformTypeLoc(UnaryTransformTypeLoc TL) {
 
 void TypeLocReader::VisitAutoTypeLoc(AutoTypeLoc TL) {
   TL.setNameLoc(readSourceLocation());
+  if (Reader.readBool()) {
+    TL.setNestedNameSpecifierLoc(ReadNestedNameSpecifierLoc());
+    TL.setTemplateKWLoc(readSourceLocation());
+    TL.setConceptNameLoc(readSourceLocation());
+    TL.setFoundDecl(Reader.readDeclAs<NamedDecl>());
+    TL.setLAngleLoc(readSourceLocation());
+    TL.setRAngleLoc(readSourceLocation());
+    for (unsigned i = 0, e = TL.getNumArgs(); i != e; ++i)
+      TL.setArgLocInfo(i, Reader.readTemplateArgumentLocInfo(
+                              TL.getTypePtr()->getArg(i).getKind()));
+  }
 }
 
 void TypeLocReader::VisitDeducedTemplateSpecializationTypeLoc(
@@ -6700,6 +6774,15 @@ void TypeLocReader::VisitPipeTypeLoc(PipeTypeLoc TL) {
   TL.setKWLoc(readSourceLocation());
 }
 
+void TypeLocReader::VisitExtIntTypeLoc(clang::ExtIntTypeLoc TL) {
+  TL.setNameLoc(readSourceLocation());
+}
+void TypeLocReader::VisitDependentExtIntTypeLoc(
+    clang::DependentExtIntTypeLoc TL) {
+  TL.setNameLoc(readSourceLocation());
+}
+
+
 void ASTRecordReader::readTypeLoc(TypeLoc TL) {
   TypeLocReader TLR(*this);
   for (; !TL.isNull(); TL = TL.getNextTypeLoc())
@@ -6778,6 +6861,9 @@ QualType ASTReader::GetType(TypeID ID) {
     case PREDEF_TYPE_INT128_ID:
       T = Context.Int128Ty;
       break;
+    case PREDEF_TYPE_BFLOAT16_ID:
+      T = Context.BFloat16Ty;
+      break;
     case PREDEF_TYPE_HALF_ID:
       T = Context.HalfTy;
       break;
@@ -6941,9 +7027,18 @@ QualType ASTReader::GetType(TypeID ID) {
     case PREDEF_TYPE_BUILTIN_FN:
       T = Context.BuiltinFnTy;
       break;
+    case PREDEF_TYPE_INCOMPLETE_MATRIX_IDX:
+      T = Context.IncompleteMatrixIdxTy;
+      break;
     case PREDEF_TYPE_OMP_ARRAY_SECTION:
       T = Context.OMPArraySectionTy;
       break;
+    case PREDEF_TYPE_OMP_ARRAY_SHAPING:
+      T = Context.OMPArraySectionTy;
+      break;
+    case PREDEF_TYPE_OMP_ITERATOR:
+      T = Context.OMPIteratorTy;
+      break;
 #define SVE_TYPE(Name, Id, SingletonId) \
     case PREDEF_TYPE_##Id##_ID: \
       T = Context.SingletonId; \
@@ -7266,6 +7361,9 @@ static Decl *getPredefinedDecl(ASTContext &Context, PredefinedDeclIDs ID) {
   case PREDEF_DECL_BUILTIN_MS_VA_LIST_ID:
     return Context.getBuiltinMSVaListDecl();
 
+  case PREDEF_DECL_BUILTIN_MS_GUID_ID:
+    return Context.getMSGuidTagDecl();
+
   case PREDEF_DECL_EXTERN_C_CONTEXT_ID:
     return Context.getExternCContextDecl();
 
@@ -7746,7 +7844,9 @@ void ASTReader::InitializeSema(Sema &S) {
   // FIXME: What happens if these are changed by a module import?
   if (!FPPragmaOptions.empty()) {
     assert(FPPragmaOptions.size() == 1 && "Wrong number of FP_PRAGMA_OPTIONS");
-    SemaObj->FPFeatures = FPOptions(FPPragmaOptions[0]);
+    FPOptionsOverride NewOverrides(FPPragmaOptions[0]);
+    SemaObj->CurFPFeatures =
+        NewOverrides.applyOverrides(SemaObj->getLangOpts());
   }
 
   SemaObj->OpenCLFeatures.copy(OpenCLExtensions);
@@ -7816,6 +7916,34 @@ void ASTReader::UpdateSema() {
       SemaObj->PackStack.CurrentPragmaLocation = PragmaPackCurrentLocation;
     }
   }
+  if (FpPragmaCurrentValue) {
+    // The bottom of the stack might have a default value. It must be adjusted
+    // to the current value to ensure that fp-pragma state is preserved after
+    // popping entries that were included/imported from a PCH/module.
+    bool DropFirst = false;
+    if (!FpPragmaStack.empty() && FpPragmaStack.front().Location.isInvalid()) {
+      assert(FpPragmaStack.front().Value ==
+                 SemaObj->FpPragmaStack.DefaultValue &&
+             "Expected a default pragma float_control value");
+      SemaObj->FpPragmaStack.Stack.emplace_back(
+          FpPragmaStack.front().SlotLabel, SemaObj->FpPragmaStack.CurrentValue,
+          SemaObj->FpPragmaStack.CurrentPragmaLocation,
+          FpPragmaStack.front().PushLocation);
+      DropFirst = true;
+    }
+    for (const auto &Entry :
+         llvm::makeArrayRef(FpPragmaStack).drop_front(DropFirst ? 1 : 0))
+      SemaObj->FpPragmaStack.Stack.emplace_back(
+          Entry.SlotLabel, Entry.Value, Entry.Location, Entry.PushLocation);
+    if (FpPragmaCurrentLocation.isInvalid()) {
+      assert(*FpPragmaCurrentValue == SemaObj->FpPragmaStack.DefaultValue &&
+             "Expected a default pragma float_control value");
+      // Keep the current values.
+    } else {
+      SemaObj->FpPragmaStack.CurrentValue = *FpPragmaCurrentValue;
+      SemaObj->FpPragmaStack.CurrentPragmaLocation = FpPragmaCurrentLocation;
+    }
+  }
 }
 
 IdentifierInfo *ASTReader::get(StringRef Name) {
@@ -8172,6 +8300,19 @@ void ASTReader::ReadUnusedLocalTypedefNameCandidates(
   UnusedLocalTypedefNameCandidates.clear();
 }
 
+void ASTReader::ReadDeclsToCheckForDeferredDiags(
+    llvm::SmallVector<Decl *, 4> &Decls) {
+  for (unsigned I = 0, N = DeclsToCheckForDeferredDiags.size(); I != N;
+       ++I) {
+    auto *D = dyn_cast_or_null<Decl>(
+        GetDecl(DeclsToCheckForDeferredDiags[I]));
+    if (D)
+      Decls.push_back(D);
+  }
+  DeclsToCheckForDeferredDiags.clear();
+}
+
+
 void ASTReader::ReadReferencedSelectors(
        SmallVectorImpl<std::pair<Selector, SourceLocation>> &Sels) {
   if (ReferencedSelectorsData.empty())
@@ -8390,7 +8531,8 @@ MacroInfo *ASTReader::getMacro(MacroID ID) {
     assert(I != GlobalMacroMap.end() && "Corrupted global macro map");
     ModuleFile *M = I->second;
     unsigned Index = ID - M->BaseMacroID;
-    MacrosLoaded[ID] = ReadMacroRecord(*M, M->MacroOffsets[Index]);
+    MacrosLoaded[ID] =
+        ReadMacroRecord(*M, M->MacroOffsetsBase + M->MacroOffsets[Index]);
 
     if (DeserializationListener)
       DeserializationListener->MacroRead(ID + NUM_PREDEF_MACRO_IDS,
@@ -8483,10 +8625,10 @@ unsigned ASTReader::getModuleFileID(ModuleFile *F) {
   return (I - PCHModules.end()) << 1;
 }
 
-llvm::Optional<ExternalASTSource::ASTSourceDescriptor>
+llvm::Optional<ASTSourceDescriptor>
 ASTReader::getSourceDescriptor(unsigned ID) {
-  if (const Module *M = getSubmodule(ID))
-    return ExternalASTSource::ASTSourceDescriptor(*M);
+  if (Module *M = getSubmodule(ID))
+    return ASTSourceDescriptor(*M);
 
   // If there is only a single PCH, return it instead.
   // Chained PCH are not supported.
@@ -8495,8 +8637,8 @@ ASTReader::getSourceDescriptor(unsigned ID) {
     ModuleFile &MF = ModuleMgr.getPrimaryModule();
     StringRef ModuleName = llvm::sys::path::filename(MF.OriginalSourceFileName);
     StringRef FileName = llvm::sys::path::filename(MF.FileName);
-    return ASTReader::ASTSourceDescriptor(ModuleName, MF.OriginalDir, FileName,
-                                          MF.Signature);
+    return ASTSourceDescriptor(ModuleName, MF.OriginalDir, FileName,
+                               MF.Signature);
   }
   return None;
 }
@@ -9440,6 +9582,446 @@ void ASTReader::diagnoseOdrViolations() {
         return Hash.CalculateHash();
       };
 
+  // Used with err_module_odr_violation_mismatch_decl and
+  // note_module_odr_violation_mismatch_decl
+  // This list should be the same Decl's as in ODRHash::isDeclToBeProcessed
+  enum ODRMismatchDecl {
+    EndOfClass,
+    PublicSpecifer,
+    PrivateSpecifer,
+    ProtectedSpecifer,
+    StaticAssert,
+    Field,
+    CXXMethod,
+    TypeAlias,
+    TypeDef,
+    Var,
+    Friend,
+    FunctionTemplate,
+    Other
+  };
+
+  // Used with err_module_odr_violation_mismatch_decl_diff and
+  // note_module_odr_violation_mismatch_decl_diff
+  enum ODRMismatchDeclDifference {
+    StaticAssertCondition,
+    StaticAssertMessage,
+    StaticAssertOnlyMessage,
+    FieldName,
+    FieldTypeName,
+    FieldSingleBitField,
+    FieldDifferentWidthBitField,
+    FieldSingleMutable,
+    FieldSingleInitializer,
+    FieldDifferentInitializers,
+    MethodName,
+    MethodDeleted,
+    MethodDefaulted,
+    MethodVirtual,
+    MethodStatic,
+    MethodVolatile,
+    MethodConst,
+    MethodInline,
+    MethodNumberParameters,
+    MethodParameterType,
+    MethodParameterName,
+    MethodParameterSingleDefaultArgument,
+    MethodParameterDifferentDefaultArgument,
+    MethodNoTemplateArguments,
+    MethodDifferentNumberTemplateArguments,
+    MethodDifferentTemplateArgument,
+    MethodSingleBody,
+    MethodDifferentBody,
+    TypedefName,
+    TypedefType,
+    VarName,
+    VarType,
+    VarSingleInitializer,
+    VarDifferentInitializer,
+    VarConstexpr,
+    FriendTypeFunction,
+    FriendType,
+    FriendFunction,
+    FunctionTemplateDifferentNumberParameters,
+    FunctionTemplateParameterDifferentKind,
+    FunctionTemplateParameterName,
+    FunctionTemplateParameterSingleDefaultArgument,
+    FunctionTemplateParameterDifferentDefaultArgument,
+    FunctionTemplateParameterDifferentType,
+    FunctionTemplatePackParameter,
+  };
+
+  // These lambdas have the common portions of the ODR diagnostics.  This
+  // has the same return as Diag(), so addition parameters can be passed
+  // in with operator<<
+  auto ODRDiagDeclError = [this](NamedDecl *FirstRecord, StringRef FirstModule,
+                                 SourceLocation Loc, SourceRange Range,
+                                 ODRMismatchDeclDifference DiffType) {
+    return Diag(Loc, diag::err_module_odr_violation_mismatch_decl_diff)
+           << FirstRecord << FirstModule.empty() << FirstModule << Range
+           << DiffType;
+  };
+  auto ODRDiagDeclNote = [this](StringRef SecondModule, SourceLocation Loc,
+                                SourceRange Range, ODRMismatchDeclDifference DiffType) {
+    return Diag(Loc, diag::note_module_odr_violation_mismatch_decl_diff)
+           << SecondModule << Range << DiffType;
+  };
+
+  auto ODRDiagField = [this, &ODRDiagDeclError, &ODRDiagDeclNote,
+                       &ComputeQualTypeODRHash, &ComputeODRHash](
+                          NamedDecl *FirstRecord, StringRef FirstModule,
+                          StringRef SecondModule, FieldDecl *FirstField,
+                          FieldDecl *SecondField) {
+    IdentifierInfo *FirstII = FirstField->getIdentifier();
+    IdentifierInfo *SecondII = SecondField->getIdentifier();
+    if (FirstII->getName() != SecondII->getName()) {
+      ODRDiagDeclError(FirstRecord, FirstModule, FirstField->getLocation(),
+                       FirstField->getSourceRange(), FieldName)
+          << FirstII;
+      ODRDiagDeclNote(SecondModule, SecondField->getLocation(),
+                      SecondField->getSourceRange(), FieldName)
+          << SecondII;
+
+      return true;
+    }
+
+    assert(getContext().hasSameType(FirstField->getType(),
+                                    SecondField->getType()));
+
+    QualType FirstType = FirstField->getType();
+    QualType SecondType = SecondField->getType();
+    if (ComputeQualTypeODRHash(FirstType) !=
+        ComputeQualTypeODRHash(SecondType)) {
+      ODRDiagDeclError(FirstRecord, FirstModule, FirstField->getLocation(),
+                       FirstField->getSourceRange(), FieldTypeName)
+          << FirstII << FirstType;
+      ODRDiagDeclNote(SecondModule, SecondField->getLocation(),
+                      SecondField->getSourceRange(), FieldTypeName)
+          << SecondII << SecondType;
+
+      return true;
+    }
+
+    const bool IsFirstBitField = FirstField->isBitField();
+    const bool IsSecondBitField = SecondField->isBitField();
+    if (IsFirstBitField != IsSecondBitField) {
+      ODRDiagDeclError(FirstRecord, FirstModule, FirstField->getLocation(),
+                       FirstField->getSourceRange(), FieldSingleBitField)
+          << FirstII << IsFirstBitField;
+      ODRDiagDeclNote(SecondModule, SecondField->getLocation(),
+                      SecondField->getSourceRange(), FieldSingleBitField)
+          << SecondII << IsSecondBitField;
+      return true;
+    }
+
+    if (IsFirstBitField && IsSecondBitField) {
+      unsigned FirstBitWidthHash =
+          ComputeODRHash(FirstField->getBitWidth());
+      unsigned SecondBitWidthHash =
+          ComputeODRHash(SecondField->getBitWidth());
+      if (FirstBitWidthHash != SecondBitWidthHash) {
+        ODRDiagDeclError(FirstRecord, FirstModule, FirstField->getLocation(),
+                         FirstField->getSourceRange(),
+                         FieldDifferentWidthBitField)
+            << FirstII << FirstField->getBitWidth()->getSourceRange();
+        ODRDiagDeclNote(SecondModule, SecondField->getLocation(),
+                        SecondField->getSourceRange(),
+                        FieldDifferentWidthBitField)
+            << SecondII << SecondField->getBitWidth()->getSourceRange();
+        return true;
+      }
+    }
+
+    if (!PP.getLangOpts().CPlusPlus)
+      return false;
+
+    const bool IsFirstMutable = FirstField->isMutable();
+    const bool IsSecondMutable = SecondField->isMutable();
+    if (IsFirstMutable != IsSecondMutable) {
+      ODRDiagDeclError(FirstRecord, FirstModule, FirstField->getLocation(),
+                       FirstField->getSourceRange(), FieldSingleMutable)
+          << FirstII << IsFirstMutable;
+      ODRDiagDeclNote(SecondModule, SecondField->getLocation(),
+                      SecondField->getSourceRange(), FieldSingleMutable)
+          << SecondII << IsSecondMutable;
+      return true;
+    }
+
+    const Expr *FirstInitializer = FirstField->getInClassInitializer();
+    const Expr *SecondInitializer = SecondField->getInClassInitializer();
+    if ((!FirstInitializer && SecondInitializer) ||
+        (FirstInitializer && !SecondInitializer)) {
+      ODRDiagDeclError(FirstRecord, FirstModule, FirstField->getLocation(),
+                       FirstField->getSourceRange(), FieldSingleInitializer)
+          << FirstII << (FirstInitializer != nullptr);
+      ODRDiagDeclNote(SecondModule, SecondField->getLocation(),
+                      SecondField->getSourceRange(), FieldSingleInitializer)
+          << SecondII << (SecondInitializer != nullptr);
+      return true;
+    }
+
+    if (FirstInitializer && SecondInitializer) {
+      unsigned FirstInitHash = ComputeODRHash(FirstInitializer);
+      unsigned SecondInitHash = ComputeODRHash(SecondInitializer);
+      if (FirstInitHash != SecondInitHash) {
+        ODRDiagDeclError(FirstRecord, FirstModule, FirstField->getLocation(),
+                         FirstField->getSourceRange(),
+                         FieldDifferentInitializers)
+            << FirstII << FirstInitializer->getSourceRange();
+        ODRDiagDeclNote(SecondModule, SecondField->getLocation(),
+                        SecondField->getSourceRange(),
+                        FieldDifferentInitializers)
+            << SecondII << SecondInitializer->getSourceRange();
+        return true;
+      }
+    }
+
+    return false;
+  };
+
+  auto ODRDiagTypeDefOrAlias =
+      [&ODRDiagDeclError, &ODRDiagDeclNote, &ComputeQualTypeODRHash](
+          NamedDecl *FirstRecord, StringRef FirstModule, StringRef SecondModule,
+          TypedefNameDecl *FirstTD, TypedefNameDecl *SecondTD,
+          bool IsTypeAlias) {
+        auto FirstName = FirstTD->getDeclName();
+        auto SecondName = SecondTD->getDeclName();
+        if (FirstName != SecondName) {
+          ODRDiagDeclError(FirstRecord, FirstModule, FirstTD->getLocation(),
+                           FirstTD->getSourceRange(), TypedefName)
+              << IsTypeAlias << FirstName;
+          ODRDiagDeclNote(SecondModule, SecondTD->getLocation(),
+                          SecondTD->getSourceRange(), TypedefName)
+              << IsTypeAlias << SecondName;
+          return true;
+        }
+
+        QualType FirstType = FirstTD->getUnderlyingType();
+        QualType SecondType = SecondTD->getUnderlyingType();
+        if (ComputeQualTypeODRHash(FirstType) !=
+            ComputeQualTypeODRHash(SecondType)) {
+          ODRDiagDeclError(FirstRecord, FirstModule, FirstTD->getLocation(),
+                           FirstTD->getSourceRange(), TypedefType)
+              << IsTypeAlias << FirstName << FirstType;
+          ODRDiagDeclNote(SecondModule, SecondTD->getLocation(),
+                          SecondTD->getSourceRange(), TypedefType)
+              << IsTypeAlias << SecondName << SecondType;
+          return true;
+        }
+
+        return false;
+  };
+
+  auto ODRDiagVar = [&ODRDiagDeclError, &ODRDiagDeclNote,
+                     &ComputeQualTypeODRHash, &ComputeODRHash,
+                     this](NamedDecl *FirstRecord, StringRef FirstModule,
+                           StringRef SecondModule, VarDecl *FirstVD,
+                           VarDecl *SecondVD) {
+    auto FirstName = FirstVD->getDeclName();
+    auto SecondName = SecondVD->getDeclName();
+    if (FirstName != SecondName) {
+      ODRDiagDeclError(FirstRecord, FirstModule, FirstVD->getLocation(),
+                       FirstVD->getSourceRange(), VarName)
+          << FirstName;
+      ODRDiagDeclNote(SecondModule, SecondVD->getLocation(),
+                      SecondVD->getSourceRange(), VarName)
+          << SecondName;
+      return true;
+    }
+
+    QualType FirstType = FirstVD->getType();
+    QualType SecondType = SecondVD->getType();
+    if (ComputeQualTypeODRHash(FirstType) !=
+        ComputeQualTypeODRHash(SecondType)) {
+      ODRDiagDeclError(FirstRecord, FirstModule, FirstVD->getLocation(),
+                       FirstVD->getSourceRange(), VarType)
+          << FirstName << FirstType;
+      ODRDiagDeclNote(SecondModule, SecondVD->getLocation(),
+                      SecondVD->getSourceRange(), VarType)
+          << SecondName << SecondType;
+      return true;
+    }
+
+    if (!PP.getLangOpts().CPlusPlus)
+      return false;
+
+    const Expr *FirstInit = FirstVD->getInit();
+    const Expr *SecondInit = SecondVD->getInit();
+    if ((FirstInit == nullptr) != (SecondInit == nullptr)) {
+      ODRDiagDeclError(FirstRecord, FirstModule, FirstVD->getLocation(),
+                       FirstVD->getSourceRange(), VarSingleInitializer)
+          << FirstName << (FirstInit == nullptr)
+          << (FirstInit ? FirstInit->getSourceRange() : SourceRange());
+      ODRDiagDeclNote(SecondModule, SecondVD->getLocation(),
+                      SecondVD->getSourceRange(), VarSingleInitializer)
+          << SecondName << (SecondInit == nullptr)
+          << (SecondInit ? SecondInit->getSourceRange() : SourceRange());
+      return true;
+    }
+
+    if (FirstInit && SecondInit &&
+        ComputeODRHash(FirstInit) != ComputeODRHash(SecondInit)) {
+      ODRDiagDeclError(FirstRecord, FirstModule, FirstVD->getLocation(),
+                       FirstVD->getSourceRange(), VarDifferentInitializer)
+          << FirstName << FirstInit->getSourceRange();
+      ODRDiagDeclNote(SecondModule, SecondVD->getLocation(),
+                      SecondVD->getSourceRange(), VarDifferentInitializer)
+          << SecondName << SecondInit->getSourceRange();
+      return true;
+    }
+
+    const bool FirstIsConstexpr = FirstVD->isConstexpr();
+    const bool SecondIsConstexpr = SecondVD->isConstexpr();
+    if (FirstIsConstexpr != SecondIsConstexpr) {
+      ODRDiagDeclError(FirstRecord, FirstModule, FirstVD->getLocation(),
+                       FirstVD->getSourceRange(), VarConstexpr)
+          << FirstName << FirstIsConstexpr;
+      ODRDiagDeclNote(SecondModule, SecondVD->getLocation(),
+                      SecondVD->getSourceRange(), VarConstexpr)
+          << SecondName << SecondIsConstexpr;
+      return true;
+    }
+    return false;
+  };
+
+  auto DifferenceSelector = [](Decl *D) {
+    assert(D && "valid Decl required");
+    switch (D->getKind()) {
+    default:
+      return Other;
+    case Decl::AccessSpec:
+      switch (D->getAccess()) {
+      case AS_public:
+        return PublicSpecifer;
+      case AS_private:
+        return PrivateSpecifer;
+      case AS_protected:
+        return ProtectedSpecifer;
+      case AS_none:
+        break;
+      }
+      llvm_unreachable("Invalid access specifier");
+    case Decl::StaticAssert:
+      return StaticAssert;
+    case Decl::Field:
+      return Field;
+    case Decl::CXXMethod:
+    case Decl::CXXConstructor:
+    case Decl::CXXDestructor:
+      return CXXMethod;
+    case Decl::TypeAlias:
+      return TypeAlias;
+    case Decl::Typedef:
+      return TypeDef;
+    case Decl::Var:
+      return Var;
+    case Decl::Friend:
+      return Friend;
+    case Decl::FunctionTemplate:
+      return FunctionTemplate;
+    }
+  };
+
+  using DeclHashes = llvm::SmallVector<std::pair<Decl *, unsigned>, 4>;
+  auto PopulateHashes = [&ComputeSubDeclODRHash](DeclHashes &Hashes,
+                                                 RecordDecl *Record,
+                                                 const DeclContext *DC) {
+    for (auto *D : Record->decls()) {
+      if (!ODRHash::isDeclToBeProcessed(D, DC))
+        continue;
+      Hashes.emplace_back(D, ComputeSubDeclODRHash(D));
+    }
+  };
+
+  struct DiffResult {
+    Decl *FirstDecl = nullptr, *SecondDecl = nullptr;
+    ODRMismatchDecl FirstDiffType = Other, SecondDiffType = Other;
+  };
+
+  // If there is a diagnoseable difference, FirstDiffType and
+  // SecondDiffType will not be Other and FirstDecl and SecondDecl will be
+  // filled in if not EndOfClass.
+  auto FindTypeDiffs = [&DifferenceSelector](DeclHashes &FirstHashes,
+                                             DeclHashes &SecondHashes) {
+    DiffResult DR;
+    auto FirstIt = FirstHashes.begin();
+    auto SecondIt = SecondHashes.begin();
+    while (FirstIt != FirstHashes.end() || SecondIt != SecondHashes.end()) {
+      if (FirstIt != FirstHashes.end() && SecondIt != SecondHashes.end() &&
+          FirstIt->second == SecondIt->second) {
+        ++FirstIt;
+        ++SecondIt;
+        continue;
+      }
+
+      DR.FirstDecl = FirstIt == FirstHashes.end() ? nullptr : FirstIt->first;
+      DR.SecondDecl =
+          SecondIt == SecondHashes.end() ? nullptr : SecondIt->first;
+
+      DR.FirstDiffType =
+          DR.FirstDecl ? DifferenceSelector(DR.FirstDecl) : EndOfClass;
+      DR.SecondDiffType =
+          DR.SecondDecl ? DifferenceSelector(DR.SecondDecl) : EndOfClass;
+      return DR;
+    }
+    return DR;
+  };
+
+  // Use this to diagnose that an unexpected Decl was encountered
+  // or no difference was detected. This causes a generic error
+  // message to be emitted.
+  auto DiagnoseODRUnexpected = [this](DiffResult &DR, NamedDecl *FirstRecord,
+                                      StringRef FirstModule,
+                                      NamedDecl *SecondRecord,
+                                      StringRef SecondModule) {
+    Diag(FirstRecord->getLocation(),
+         diag::err_module_odr_violation_different_definitions)
+        << FirstRecord << FirstModule.empty() << FirstModule;
+
+    if (DR.FirstDecl) {
+      Diag(DR.FirstDecl->getLocation(), diag::note_first_module_difference)
+          << FirstRecord << DR.FirstDecl->getSourceRange();
+    }
+
+    Diag(SecondRecord->getLocation(),
+         diag::note_module_odr_violation_different_definitions)
+        << SecondModule;
+
+    if (DR.SecondDecl) {
+      Diag(DR.SecondDecl->getLocation(), diag::note_second_module_difference)
+          << DR.SecondDecl->getSourceRange();
+    }
+  };
+
+  auto DiagnoseODRMismatch =
+      [this](DiffResult &DR, NamedDecl *FirstRecord, StringRef FirstModule,
+             NamedDecl *SecondRecord, StringRef SecondModule) {
+        SourceLocation FirstLoc;
+        SourceRange FirstRange;
+        auto *FirstTag = dyn_cast<TagDecl>(FirstRecord);
+        if (DR.FirstDiffType == EndOfClass && FirstTag) {
+          FirstLoc = FirstTag->getBraceRange().getEnd();
+        } else {
+          FirstLoc = DR.FirstDecl->getLocation();
+          FirstRange = DR.FirstDecl->getSourceRange();
+        }
+        Diag(FirstLoc, diag::err_module_odr_violation_mismatch_decl)
+            << FirstRecord << FirstModule.empty() << FirstModule << FirstRange
+            << DR.FirstDiffType;
+
+        SourceLocation SecondLoc;
+        SourceRange SecondRange;
+        auto *SecondTag = dyn_cast<TagDecl>(SecondRecord);
+        if (DR.SecondDiffType == EndOfClass && SecondTag) {
+          SecondLoc = SecondTag->getBraceRange().getEnd();
+        } else {
+          SecondLoc = DR.SecondDecl->getLocation();
+          SecondRange = DR.SecondDecl->getSourceRange();
+        }
+        Diag(SecondLoc, diag::note_module_odr_violation_mismatch_decl)
+            << SecondModule << SecondRange << DR.SecondDiffType;
+      };
+
   // Issue any pending ODR-failure diagnostics.
   for (auto &Merge : OdrMergeFailures) {
     // If we've already pointed out a specific problem with this class, don't
@@ -9473,16 +10055,16 @@ void ASTReader::diagnoseOdrViolations() {
           BaseVirtual,
           BaseAccess,
         };
-        auto ODRDiagError = [FirstRecord, &FirstModule,
-                             this](SourceLocation Loc, SourceRange Range,
-                                   ODRDefinitionDataDifference DiffType) {
+        auto ODRDiagBaseError = [FirstRecord, &FirstModule,
+                                 this](SourceLocation Loc, SourceRange Range,
+                                       ODRDefinitionDataDifference DiffType) {
           return Diag(Loc, diag::err_module_odr_violation_definition_data)
                  << FirstRecord << FirstModule.empty() << FirstModule << Range
                  << DiffType;
         };
-        auto ODRDiagNote = [&SecondModule,
-                            this](SourceLocation Loc, SourceRange Range,
-                                  ODRDefinitionDataDifference DiffType) {
+        auto ODRDiagBaseNote = [&SecondModule,
+                                this](SourceLocation Loc, SourceRange Range,
+                                      ODRDefinitionDataDifference DiffType) {
           return Diag(Loc, diag::note_module_odr_violation_definition_data)
                  << SecondModule << Range << DiffType;
         };
@@ -9501,22 +10083,22 @@ void ASTReader::diagnoseOdrViolations() {
         };
 
         if (FirstNumBases != SecondNumBases) {
-          ODRDiagError(FirstRecord->getLocation(), GetSourceRange(FirstDD),
-                       NumBases)
+          ODRDiagBaseError(FirstRecord->getLocation(), GetSourceRange(FirstDD),
+                           NumBases)
               << FirstNumBases;
-          ODRDiagNote(SecondRecord->getLocation(), GetSourceRange(SecondDD),
-                      NumBases)
+          ODRDiagBaseNote(SecondRecord->getLocation(), GetSourceRange(SecondDD),
+                          NumBases)
               << SecondNumBases;
           Diagnosed = true;
           break;
         }
 
         if (FirstNumVBases != SecondNumVBases) {
-          ODRDiagError(FirstRecord->getLocation(), GetSourceRange(FirstDD),
-                       NumVBases)
+          ODRDiagBaseError(FirstRecord->getLocation(), GetSourceRange(FirstDD),
+                           NumVBases)
               << FirstNumVBases;
-          ODRDiagNote(SecondRecord->getLocation(), GetSourceRange(SecondDD),
-                      NumVBases)
+          ODRDiagBaseNote(SecondRecord->getLocation(), GetSourceRange(SecondDD),
+                          NumVBases)
               << SecondNumVBases;
           Diagnosed = true;
           break;
@@ -9530,33 +10112,33 @@ void ASTReader::diagnoseOdrViolations() {
           auto SecondBase = SecondBases[i];
           if (ComputeQualTypeODRHash(FirstBase.getType()) !=
               ComputeQualTypeODRHash(SecondBase.getType())) {
-            ODRDiagError(FirstRecord->getLocation(), FirstBase.getSourceRange(),
-                         BaseType)
+            ODRDiagBaseError(FirstRecord->getLocation(),
+                             FirstBase.getSourceRange(), BaseType)
                 << (i + 1) << FirstBase.getType();
-            ODRDiagNote(SecondRecord->getLocation(),
-                        SecondBase.getSourceRange(), BaseType)
+            ODRDiagBaseNote(SecondRecord->getLocation(),
+                            SecondBase.getSourceRange(), BaseType)
                 << (i + 1) << SecondBase.getType();
             break;
           }
 
           if (FirstBase.isVirtual() != SecondBase.isVirtual()) {
-            ODRDiagError(FirstRecord->getLocation(), FirstBase.getSourceRange(),
-                         BaseVirtual)
+            ODRDiagBaseError(FirstRecord->getLocation(),
+                             FirstBase.getSourceRange(), BaseVirtual)
                 << (i + 1) << FirstBase.isVirtual() << FirstBase.getType();
-            ODRDiagNote(SecondRecord->getLocation(),
-                        SecondBase.getSourceRange(), BaseVirtual)
+            ODRDiagBaseNote(SecondRecord->getLocation(),
+                            SecondBase.getSourceRange(), BaseVirtual)
                 << (i + 1) << SecondBase.isVirtual() << SecondBase.getType();
             break;
           }
 
           if (FirstBase.getAccessSpecifierAsWritten() !=
               SecondBase.getAccessSpecifierAsWritten()) {
-            ODRDiagError(FirstRecord->getLocation(), FirstBase.getSourceRange(),
-                         BaseAccess)
+            ODRDiagBaseError(FirstRecord->getLocation(),
+                             FirstBase.getSourceRange(), BaseAccess)
                 << (i + 1) << FirstBase.getType()
                 << (int)FirstBase.getAccessSpecifierAsWritten();
-            ODRDiagNote(SecondRecord->getLocation(),
-                        SecondBase.getSourceRange(), BaseAccess)
+            ODRDiagBaseNote(SecondRecord->getLocation(),
+                            SecondBase.getSourceRange(), BaseAccess)
                 << (i + 1) << SecondBase.getType()
                 << (int)SecondBase.getAccessSpecifierAsWritten();
             break;
@@ -9569,8 +10151,6 @@ void ASTReader::diagnoseOdrViolations() {
         }
       }
 
-      using DeclHashes = llvm::SmallVector<std::pair<Decl *, unsigned>, 4>;
-
       const ClassTemplateDecl *FirstTemplate =
           FirstRecord->getDescribedClassTemplate();
       const ClassTemplateDecl *SecondTemplate =
@@ -9611,16 +10191,16 @@ void ASTReader::diagnoseOdrViolations() {
           if (FirstIt->second == SecondIt->second)
             continue;
 
-          auto ODRDiagError = [FirstRecord, &FirstModule,
-                               this](SourceLocation Loc, SourceRange Range,
-                                     ODRTemplateDifference DiffType) {
+          auto ODRDiagTemplateError = [FirstRecord, &FirstModule, this](
+                                          SourceLocation Loc, SourceRange Range,
+                                          ODRTemplateDifference DiffType) {
             return Diag(Loc, diag::err_module_odr_violation_template_parameter)
                    << FirstRecord << FirstModule.empty() << FirstModule << Range
                    << DiffType;
           };
-          auto ODRDiagNote = [&SecondModule,
-                              this](SourceLocation Loc, SourceRange Range,
-                                    ODRTemplateDifference DiffType) {
+          auto ODRDiagTemplateNote = [&SecondModule, this](
+                                         SourceLocation Loc, SourceRange Range,
+                                         ODRTemplateDifference DiffType) {
             return Diag(Loc, diag::note_module_odr_violation_template_parameter)
                    << SecondModule << Range << DiffType;
           };
@@ -9641,11 +10221,13 @@ void ASTReader::diagnoseOdrViolations() {
                 SecondName.isIdentifier() && !SecondName.getAsIdentifierInfo();
             assert((!FirstNameEmpty || !SecondNameEmpty) &&
                    "Both template parameters cannot be unnamed.");
-            ODRDiagError(FirstDecl->getLocation(), FirstDecl->getSourceRange(),
-                         FirstNameEmpty ? ParamEmptyName : ParamName)
+            ODRDiagTemplateError(FirstDecl->getLocation(),
+                                 FirstDecl->getSourceRange(),
+                                 FirstNameEmpty ? ParamEmptyName : ParamName)
                 << FirstName;
-            ODRDiagNote(SecondDecl->getLocation(), SecondDecl->getSourceRange(),
-                        SecondNameEmpty ? ParamEmptyName : ParamName)
+            ODRDiagTemplateNote(SecondDecl->getLocation(),
+                                SecondDecl->getSourceRange(),
+                                SecondNameEmpty ? ParamEmptyName : ParamName)
                 << SecondName;
             break;
           }
@@ -9664,13 +10246,13 @@ void ASTReader::diagnoseOdrViolations() {
                 !SecondParam->defaultArgumentWasInherited();
 
             if (HasFirstDefaultArgument != HasSecondDefaultArgument) {
-              ODRDiagError(FirstDecl->getLocation(),
-                           FirstDecl->getSourceRange(),
-                           ParamSingleDefaultArgument)
+              ODRDiagTemplateError(FirstDecl->getLocation(),
+                                   FirstDecl->getSourceRange(),
+                                   ParamSingleDefaultArgument)
                   << HasFirstDefaultArgument;
-              ODRDiagNote(SecondDecl->getLocation(),
-                          SecondDecl->getSourceRange(),
-                          ParamSingleDefaultArgument)
+              ODRDiagTemplateNote(SecondDecl->getLocation(),
+                                  SecondDecl->getSourceRange(),
+                                  ParamSingleDefaultArgument)
                   << HasSecondDefaultArgument;
               break;
             }
@@ -9678,10 +10260,12 @@ void ASTReader::diagnoseOdrViolations() {
             assert(HasFirstDefaultArgument && HasSecondDefaultArgument &&
                    "Expecting default arguments.");
 
-            ODRDiagError(FirstDecl->getLocation(), FirstDecl->getSourceRange(),
-                         ParamDifferentDefaultArgument);
-            ODRDiagNote(SecondDecl->getLocation(), SecondDecl->getSourceRange(),
-                        ParamDifferentDefaultArgument);
+            ODRDiagTemplateError(FirstDecl->getLocation(),
+                                 FirstDecl->getSourceRange(),
+                                 ParamDifferentDefaultArgument);
+            ODRDiagTemplateNote(SecondDecl->getLocation(),
+                                SecondDecl->getSourceRange(),
+                                ParamDifferentDefaultArgument);
 
             break;
           }
@@ -9696,13 +10280,13 @@ void ASTReader::diagnoseOdrViolations() {
                 !SecondParam->defaultArgumentWasInherited();
 
             if (HasFirstDefaultArgument != HasSecondDefaultArgument) {
-              ODRDiagError(FirstDecl->getLocation(),
-                           FirstDecl->getSourceRange(),
-                           ParamSingleDefaultArgument)
+              ODRDiagTemplateError(FirstDecl->getLocation(),
+                                   FirstDecl->getSourceRange(),
+                                   ParamSingleDefaultArgument)
                   << HasFirstDefaultArgument;
-              ODRDiagNote(SecondDecl->getLocation(),
-                          SecondDecl->getSourceRange(),
-                          ParamSingleDefaultArgument)
+              ODRDiagTemplateNote(SecondDecl->getLocation(),
+                                  SecondDecl->getSourceRange(),
+                                  ParamSingleDefaultArgument)
                   << HasSecondDefaultArgument;
               break;
             }
@@ -9710,10 +10294,12 @@ void ASTReader::diagnoseOdrViolations() {
             assert(HasFirstDefaultArgument && HasSecondDefaultArgument &&
                    "Expecting default arguments.");
 
-            ODRDiagError(FirstDecl->getLocation(), FirstDecl->getSourceRange(),
-                         ParamDifferentDefaultArgument);
-            ODRDiagNote(SecondDecl->getLocation(), SecondDecl->getSourceRange(),
-                        ParamDifferentDefaultArgument);
+            ODRDiagTemplateError(FirstDecl->getLocation(),
+                                 FirstDecl->getSourceRange(),
+                                 ParamDifferentDefaultArgument);
+            ODRDiagTemplateNote(SecondDecl->getLocation(),
+                                SecondDecl->getSourceRange(),
+                                ParamDifferentDefaultArgument);
 
             break;
           }
@@ -9729,13 +10315,13 @@ void ASTReader::diagnoseOdrViolations() {
                 !SecondParam->defaultArgumentWasInherited();
 
             if (HasFirstDefaultArgument != HasSecondDefaultArgument) {
-              ODRDiagError(FirstDecl->getLocation(),
-                           FirstDecl->getSourceRange(),
-                           ParamSingleDefaultArgument)
+              ODRDiagTemplateError(FirstDecl->getLocation(),
+                                   FirstDecl->getSourceRange(),
+                                   ParamSingleDefaultArgument)
                   << HasFirstDefaultArgument;
-              ODRDiagNote(SecondDecl->getLocation(),
-                          SecondDecl->getSourceRange(),
-                          ParamSingleDefaultArgument)
+              ODRDiagTemplateNote(SecondDecl->getLocation(),
+                                  SecondDecl->getSourceRange(),
+                                  ParamSingleDefaultArgument)
                   << HasSecondDefaultArgument;
               break;
             }
@@ -9743,10 +10329,12 @@ void ASTReader::diagnoseOdrViolations() {
             assert(HasFirstDefaultArgument && HasSecondDefaultArgument &&
                    "Expecting default arguments.");
 
-            ODRDiagError(FirstDecl->getLocation(), FirstDecl->getSourceRange(),
-                         ParamDifferentDefaultArgument);
-            ODRDiagNote(SecondDecl->getLocation(), SecondDecl->getSourceRange(),
-                        ParamDifferentDefaultArgument);
+            ODRDiagTemplateError(FirstDecl->getLocation(),
+                                 FirstDecl->getSourceRange(),
+                                 ParamDifferentDefaultArgument);
+            ODRDiagTemplateNote(SecondDecl->getLocation(),
+                                SecondDecl->getSourceRange(),
+                                ParamDifferentDefaultArgument);
 
             break;
           }
@@ -9763,224 +10351,32 @@ void ASTReader::diagnoseOdrViolations() {
 
       DeclHashes FirstHashes;
       DeclHashes SecondHashes;
+      const DeclContext *DC = FirstRecord;
+      PopulateHashes(FirstHashes, FirstRecord, DC);
+      PopulateHashes(SecondHashes, SecondRecord, DC);
 
-      auto PopulateHashes = [&ComputeSubDeclODRHash, FirstRecord](
-                                DeclHashes &Hashes, CXXRecordDecl *Record) {
-        for (auto *D : Record->decls()) {
-          // Due to decl merging, the first CXXRecordDecl is the parent of
-          // Decls in both records.
-          if (!ODRHash::isWhitelistedDecl(D, FirstRecord))
-            continue;
-          Hashes.emplace_back(D, ComputeSubDeclODRHash(D));
-        }
-      };
-      PopulateHashes(FirstHashes, FirstRecord);
-      PopulateHashes(SecondHashes, SecondRecord);
-
-      // Used with err_module_odr_violation_mismatch_decl and
-      // note_module_odr_violation_mismatch_decl
-      // This list should be the same Decl's as in ODRHash::isWhiteListedDecl
-      enum {
-        EndOfClass,
-        PublicSpecifer,
-        PrivateSpecifer,
-        ProtectedSpecifer,
-        StaticAssert,
-        Field,
-        CXXMethod,
-        TypeAlias,
-        TypeDef,
-        Var,
-        Friend,
-        FunctionTemplate,
-        Other
-      } FirstDiffType = Other,
-        SecondDiffType = Other;
-
-      auto DifferenceSelector = [](Decl *D) {
-        assert(D && "valid Decl required");
-        switch (D->getKind()) {
-        default:
-          return Other;
-        case Decl::AccessSpec:
-          switch (D->getAccess()) {
-          case AS_public:
-            return PublicSpecifer;
-          case AS_private:
-            return PrivateSpecifer;
-          case AS_protected:
-            return ProtectedSpecifer;
-          case AS_none:
-            break;
-          }
-          llvm_unreachable("Invalid access specifier");
-        case Decl::StaticAssert:
-          return StaticAssert;
-        case Decl::Field:
-          return Field;
-        case Decl::CXXMethod:
-        case Decl::CXXConstructor:
-        case Decl::CXXDestructor:
-          return CXXMethod;
-        case Decl::TypeAlias:
-          return TypeAlias;
-        case Decl::Typedef:
-          return TypeDef;
-        case Decl::Var:
-          return Var;
-        case Decl::Friend:
-          return Friend;
-        case Decl::FunctionTemplate:
-          return FunctionTemplate;
-        }
-      };
-
-      Decl *FirstDecl = nullptr;
-      Decl *SecondDecl = nullptr;
-      auto FirstIt = FirstHashes.begin();
-      auto SecondIt = SecondHashes.begin();
-
-      // If there is a diagnoseable difference, FirstDiffType and
-      // SecondDiffType will not be Other and FirstDecl and SecondDecl will be
-      // filled in if not EndOfClass.
-      while (FirstIt != FirstHashes.end() || SecondIt != SecondHashes.end()) {
-        if (FirstIt != FirstHashes.end() && SecondIt != SecondHashes.end() &&
-            FirstIt->second == SecondIt->second) {
-          ++FirstIt;
-          ++SecondIt;
-          continue;
-        }
-
-        FirstDecl = FirstIt == FirstHashes.end() ? nullptr : FirstIt->first;
-        SecondDecl = SecondIt == SecondHashes.end() ? nullptr : SecondIt->first;
-
-        FirstDiffType = FirstDecl ? DifferenceSelector(FirstDecl) : EndOfClass;
-        SecondDiffType =
-            SecondDecl ? DifferenceSelector(SecondDecl) : EndOfClass;
-
-        break;
-      }
+      auto DR = FindTypeDiffs(FirstHashes, SecondHashes);
+      ODRMismatchDecl FirstDiffType = DR.FirstDiffType;
+      ODRMismatchDecl SecondDiffType = DR.SecondDiffType;
+      Decl *FirstDecl = DR.FirstDecl;
+      Decl *SecondDecl = DR.SecondDecl;
 
       if (FirstDiffType == Other || SecondDiffType == Other) {
-        // Reaching this point means an unexpected Decl was encountered
-        // or no difference was detected.  This causes a generic error
-        // message to be emitted.
-        Diag(FirstRecord->getLocation(),
-             diag::err_module_odr_violation_different_definitions)
-            << FirstRecord << FirstModule.empty() << FirstModule;
-
-        if (FirstDecl) {
-          Diag(FirstDecl->getLocation(), diag::note_first_module_difference)
-              << FirstRecord << FirstDecl->getSourceRange();
-        }
-
-        Diag(SecondRecord->getLocation(),
-             diag::note_module_odr_violation_different_definitions)
-            << SecondModule;
-
-        if (SecondDecl) {
-          Diag(SecondDecl->getLocation(), diag::note_second_module_difference)
-              << SecondDecl->getSourceRange();
-        }
-
+        DiagnoseODRUnexpected(DR, FirstRecord, FirstModule, SecondRecord,
+                              SecondModule);
         Diagnosed = true;
         break;
       }
 
       if (FirstDiffType != SecondDiffType) {
-        SourceLocation FirstLoc;
-        SourceRange FirstRange;
-        if (FirstDiffType == EndOfClass) {
-          FirstLoc = FirstRecord->getBraceRange().getEnd();
-        } else {
-          FirstLoc = FirstIt->first->getLocation();
-          FirstRange = FirstIt->first->getSourceRange();
-        }
-        Diag(FirstLoc, diag::err_module_odr_violation_mismatch_decl)
-            << FirstRecord << FirstModule.empty() << FirstModule << FirstRange
-            << FirstDiffType;
-
-        SourceLocation SecondLoc;
-        SourceRange SecondRange;
-        if (SecondDiffType == EndOfClass) {
-          SecondLoc = SecondRecord->getBraceRange().getEnd();
-        } else {
-          SecondLoc = SecondDecl->getLocation();
-          SecondRange = SecondDecl->getSourceRange();
-        }
-        Diag(SecondLoc, diag::note_module_odr_violation_mismatch_decl)
-            << SecondModule << SecondRange << SecondDiffType;
+        DiagnoseODRMismatch(DR, FirstRecord, FirstModule, SecondRecord,
+                            SecondModule);
         Diagnosed = true;
         break;
       }
 
       assert(FirstDiffType == SecondDiffType);
 
-      // Used with err_module_odr_violation_mismatch_decl_diff and
-      // note_module_odr_violation_mismatch_decl_diff
-      enum ODRDeclDifference {
-        StaticAssertCondition,
-        StaticAssertMessage,
-        StaticAssertOnlyMessage,
-        FieldName,
-        FieldTypeName,
-        FieldSingleBitField,
-        FieldDifferentWidthBitField,
-        FieldSingleMutable,
-        FieldSingleInitializer,
-        FieldDifferentInitializers,
-        MethodName,
-        MethodDeleted,
-        MethodDefaulted,
-        MethodVirtual,
-        MethodStatic,
-        MethodVolatile,
-        MethodConst,
-        MethodInline,
-        MethodNumberParameters,
-        MethodParameterType,
-        MethodParameterName,
-        MethodParameterSingleDefaultArgument,
-        MethodParameterDifferentDefaultArgument,
-        MethodNoTemplateArguments,
-        MethodDifferentNumberTemplateArguments,
-        MethodDifferentTemplateArgument,
-        MethodSingleBody,
-        MethodDifferentBody,
-        TypedefName,
-        TypedefType,
-        VarName,
-        VarType,
-        VarSingleInitializer,
-        VarDifferentInitializer,
-        VarConstexpr,
-        FriendTypeFunction,
-        FriendType,
-        FriendFunction,
-        FunctionTemplateDifferentNumberParameters,
-        FunctionTemplateParameterDifferentKind,
-        FunctionTemplateParameterName,
-        FunctionTemplateParameterSingleDefaultArgument,
-        FunctionTemplateParameterDifferentDefaultArgument,
-        FunctionTemplateParameterDifferentType,
-        FunctionTemplatePackParameter,
-      };
-
-      // These lambdas have the common portions of the ODR diagnostics.  This
-      // has the same return as Diag(), so addition parameters can be passed
-      // in with operator<<
-      auto ODRDiagError = [FirstRecord, &FirstModule, this](
-          SourceLocation Loc, SourceRange Range, ODRDeclDifference DiffType) {
-        return Diag(Loc, diag::err_module_odr_violation_mismatch_decl_diff)
-               << FirstRecord << FirstModule.empty() << FirstModule << Range
-               << DiffType;
-      };
-      auto ODRDiagNote = [&SecondModule, this](
-          SourceLocation Loc, SourceRange Range, ODRDeclDifference DiffType) {
-        return Diag(Loc, diag::note_module_odr_violation_mismatch_decl_diff)
-               << SecondModule << Range << DiffType;
-      };
-
       switch (FirstDiffType) {
       case Other:
       case EndOfClass:
@@ -9998,10 +10394,10 @@ void ASTReader::diagnoseOdrViolations() {
         unsigned FirstODRHash = ComputeODRHash(FirstExpr);
         unsigned SecondODRHash = ComputeODRHash(SecondExpr);
         if (FirstODRHash != SecondODRHash) {
-          ODRDiagError(FirstExpr->getBeginLoc(), FirstExpr->getSourceRange(),
-                       StaticAssertCondition);
-          ODRDiagNote(SecondExpr->getBeginLoc(), SecondExpr->getSourceRange(),
-                      StaticAssertCondition);
+          ODRDiagDeclError(FirstRecord, FirstModule, FirstExpr->getBeginLoc(),
+                           FirstExpr->getSourceRange(), StaticAssertCondition);
+          ODRDiagDeclNote(SecondModule, SecondExpr->getBeginLoc(),
+                          SecondExpr->getSourceRange(), StaticAssertCondition);
           Diagnosed = true;
           break;
         }
@@ -10026,9 +10422,11 @@ void ASTReader::diagnoseOdrViolations() {
             SecondLoc = SecondSA->getBeginLoc();
             SecondRange = SecondSA->getSourceRange();
           }
-          ODRDiagError(FirstLoc, FirstRange, StaticAssertOnlyMessage)
+          ODRDiagDeclError(FirstRecord, FirstModule, FirstLoc, FirstRange,
+                           StaticAssertOnlyMessage)
               << (FirstStr == nullptr);
-          ODRDiagNote(SecondLoc, SecondRange, StaticAssertOnlyMessage)
+          ODRDiagDeclNote(SecondModule, SecondLoc, SecondRange,
+                          StaticAssertOnlyMessage)
               << (SecondStr == nullptr);
           Diagnosed = true;
           break;
@@ -10036,126 +10434,19 @@ void ASTReader::diagnoseOdrViolations() {
 
         if (FirstStr && SecondStr &&
             FirstStr->getString() != SecondStr->getString()) {
-          ODRDiagError(FirstStr->getBeginLoc(), FirstStr->getSourceRange(),
-                       StaticAssertMessage);
-          ODRDiagNote(SecondStr->getBeginLoc(), SecondStr->getSourceRange(),
-                      StaticAssertMessage);
+          ODRDiagDeclError(FirstRecord, FirstModule, FirstStr->getBeginLoc(),
+                           FirstStr->getSourceRange(), StaticAssertMessage);
+          ODRDiagDeclNote(SecondModule, SecondStr->getBeginLoc(),
+                          SecondStr->getSourceRange(), StaticAssertMessage);
           Diagnosed = true;
           break;
         }
         break;
       }
       case Field: {
-        FieldDecl *FirstField = cast<FieldDecl>(FirstDecl);
-        FieldDecl *SecondField = cast<FieldDecl>(SecondDecl);
-        IdentifierInfo *FirstII = FirstField->getIdentifier();
-        IdentifierInfo *SecondII = SecondField->getIdentifier();
-        if (FirstII->getName() != SecondII->getName()) {
-          ODRDiagError(FirstField->getLocation(), FirstField->getSourceRange(),
-                       FieldName)
-              << FirstII;
-          ODRDiagNote(SecondField->getLocation(), SecondField->getSourceRange(),
-                      FieldName)
-              << SecondII;
-
-          Diagnosed = true;
-          break;
-        }
-
-        assert(getContext().hasSameType(FirstField->getType(),
-                                        SecondField->getType()));
-
-        QualType FirstType = FirstField->getType();
-        QualType SecondType = SecondField->getType();
-        if (ComputeQualTypeODRHash(FirstType) !=
-            ComputeQualTypeODRHash(SecondType)) {
-          ODRDiagError(FirstField->getLocation(), FirstField->getSourceRange(),
-                       FieldTypeName)
-              << FirstII << FirstType;
-          ODRDiagNote(SecondField->getLocation(), SecondField->getSourceRange(),
-                      FieldTypeName)
-              << SecondII << SecondType;
-
-          Diagnosed = true;
-          break;
-        }
-
-        const bool IsFirstBitField = FirstField->isBitField();
-        const bool IsSecondBitField = SecondField->isBitField();
-        if (IsFirstBitField != IsSecondBitField) {
-          ODRDiagError(FirstField->getLocation(), FirstField->getSourceRange(),
-                       FieldSingleBitField)
-              << FirstII << IsFirstBitField;
-          ODRDiagNote(SecondField->getLocation(), SecondField->getSourceRange(),
-                      FieldSingleBitField)
-              << SecondII << IsSecondBitField;
-          Diagnosed = true;
-          break;
-        }
-
-        if (IsFirstBitField && IsSecondBitField) {
-          unsigned FirstBitWidthHash =
-              ComputeODRHash(FirstField->getBitWidth());
-          unsigned SecondBitWidthHash =
-              ComputeODRHash(SecondField->getBitWidth());
-          if (FirstBitWidthHash != SecondBitWidthHash) {
-            ODRDiagError(FirstField->getLocation(),
-                         FirstField->getSourceRange(),
-                         FieldDifferentWidthBitField)
-                << FirstII << FirstField->getBitWidth()->getSourceRange();
-            ODRDiagNote(SecondField->getLocation(),
-                        SecondField->getSourceRange(),
-                        FieldDifferentWidthBitField)
-                << SecondII << SecondField->getBitWidth()->getSourceRange();
-            Diagnosed = true;
-            break;
-          }
-        }
-
-        const bool IsFirstMutable = FirstField->isMutable();
-        const bool IsSecondMutable = SecondField->isMutable();
-        if (IsFirstMutable != IsSecondMutable) {
-          ODRDiagError(FirstField->getLocation(), FirstField->getSourceRange(),
-                       FieldSingleMutable)
-              << FirstII << IsFirstMutable;
-          ODRDiagNote(SecondField->getLocation(), SecondField->getSourceRange(),
-                      FieldSingleMutable)
-              << SecondII << IsSecondMutable;
-          Diagnosed = true;
-          break;
-        }
-
-        const Expr *FirstInitializer = FirstField->getInClassInitializer();
-        const Expr *SecondInitializer = SecondField->getInClassInitializer();
-        if ((!FirstInitializer && SecondInitializer) ||
-            (FirstInitializer && !SecondInitializer)) {
-          ODRDiagError(FirstField->getLocation(), FirstField->getSourceRange(),
-                       FieldSingleInitializer)
-              << FirstII << (FirstInitializer != nullptr);
-          ODRDiagNote(SecondField->getLocation(), SecondField->getSourceRange(),
-                      FieldSingleInitializer)
-              << SecondII << (SecondInitializer != nullptr);
-          Diagnosed = true;
-          break;
-        }
-
-        if (FirstInitializer && SecondInitializer) {
-          unsigned FirstInitHash = ComputeODRHash(FirstInitializer);
-          unsigned SecondInitHash = ComputeODRHash(SecondInitializer);
-          if (FirstInitHash != SecondInitHash) {
-            ODRDiagError(FirstField->getLocation(),
-                         FirstField->getSourceRange(),
-                         FieldDifferentInitializers)
-                << FirstII << FirstInitializer->getSourceRange();
-            ODRDiagNote(SecondField->getLocation(),
-                        SecondField->getSourceRange(),
-                        FieldDifferentInitializers)
-                << SecondII << SecondInitializer->getSourceRange();
-            Diagnosed = true;
-            break;
-          }
-        }
-
+        Diagnosed = ODRDiagField(FirstRecord, FirstModule, SecondModule,
+                                 cast<FieldDecl>(FirstDecl),
+                                 cast<FieldDecl>(SecondDecl));
         break;
       }
       case CXXMethod: {
@@ -10177,11 +10468,11 @@ void ASTReader::diagnoseOdrViolations() {
         auto FirstName = FirstMethod->getDeclName();
         auto SecondName = SecondMethod->getDeclName();
         if (FirstMethodType != SecondMethodType || FirstName != SecondName) {
-          ODRDiagError(FirstMethod->getLocation(),
-                       FirstMethod->getSourceRange(), MethodName)
+          ODRDiagDeclError(FirstRecord, FirstModule, FirstMethod->getLocation(),
+                           FirstMethod->getSourceRange(), MethodName)
               << FirstMethodType << FirstName;
-          ODRDiagNote(SecondMethod->getLocation(),
-                      SecondMethod->getSourceRange(), MethodName)
+          ODRDiagDeclNote(SecondModule, SecondMethod->getLocation(),
+                          SecondMethod->getSourceRange(), MethodName)
               << SecondMethodType << SecondName;
 
           Diagnosed = true;
@@ -10191,12 +10482,12 @@ void ASTReader::diagnoseOdrViolations() {
         const bool FirstDeleted = FirstMethod->isDeletedAsWritten();
         const bool SecondDeleted = SecondMethod->isDeletedAsWritten();
         if (FirstDeleted != SecondDeleted) {
-          ODRDiagError(FirstMethod->getLocation(),
-                       FirstMethod->getSourceRange(), MethodDeleted)
+          ODRDiagDeclError(FirstRecord, FirstModule, FirstMethod->getLocation(),
+                           FirstMethod->getSourceRange(), MethodDeleted)
               << FirstMethodType << FirstName << FirstDeleted;
 
-          ODRDiagNote(SecondMethod->getLocation(),
-                      SecondMethod->getSourceRange(), MethodDeleted)
+          ODRDiagDeclNote(SecondModule, SecondMethod->getLocation(),
+                          SecondMethod->getSourceRange(), MethodDeleted)
               << SecondMethodType << SecondName << SecondDeleted;
           Diagnosed = true;
           break;
@@ -10205,12 +10496,12 @@ void ASTReader::diagnoseOdrViolations() {
         const bool FirstDefaulted = FirstMethod->isExplicitlyDefaulted();
         const bool SecondDefaulted = SecondMethod->isExplicitlyDefaulted();
         if (FirstDefaulted != SecondDefaulted) {
-          ODRDiagError(FirstMethod->getLocation(),
-                       FirstMethod->getSourceRange(), MethodDefaulted)
+          ODRDiagDeclError(FirstRecord, FirstModule, FirstMethod->getLocation(),
+                           FirstMethod->getSourceRange(), MethodDefaulted)
               << FirstMethodType << FirstName << FirstDefaulted;
 
-          ODRDiagNote(SecondMethod->getLocation(),
-                      SecondMethod->getSourceRange(), MethodDefaulted)
+          ODRDiagDeclNote(SecondModule, SecondMethod->getLocation(),
+                          SecondMethod->getSourceRange(), MethodDefaulted)
               << SecondMethodType << SecondName << SecondDefaulted;
           Diagnosed = true;
           break;
@@ -10222,11 +10513,11 @@ void ASTReader::diagnoseOdrViolations() {
         const bool SecondPure = SecondMethod->isPure();
         if ((FirstVirtual || SecondVirtual) &&
             (FirstVirtual != SecondVirtual || FirstPure != SecondPure)) {
-          ODRDiagError(FirstMethod->getLocation(),
-                       FirstMethod->getSourceRange(), MethodVirtual)
+          ODRDiagDeclError(FirstRecord, FirstModule, FirstMethod->getLocation(),
+                           FirstMethod->getSourceRange(), MethodVirtual)
               << FirstMethodType << FirstName << FirstPure << FirstVirtual;
-          ODRDiagNote(SecondMethod->getLocation(),
-                      SecondMethod->getSourceRange(), MethodVirtual)
+          ODRDiagDeclNote(SecondModule, SecondMethod->getLocation(),
+                          SecondMethod->getSourceRange(), MethodVirtual)
               << SecondMethodType << SecondName << SecondPure << SecondVirtual;
           Diagnosed = true;
           break;
@@ -10240,11 +10531,11 @@ void ASTReader::diagnoseOdrViolations() {
         const bool FirstStatic = FirstStorage == SC_Static;
         const bool SecondStatic = SecondStorage == SC_Static;
         if (FirstStatic != SecondStatic) {
-          ODRDiagError(FirstMethod->getLocation(),
-                       FirstMethod->getSourceRange(), MethodStatic)
+          ODRDiagDeclError(FirstRecord, FirstModule, FirstMethod->getLocation(),
+                           FirstMethod->getSourceRange(), MethodStatic)
               << FirstMethodType << FirstName << FirstStatic;
-          ODRDiagNote(SecondMethod->getLocation(),
-                      SecondMethod->getSourceRange(), MethodStatic)
+          ODRDiagDeclNote(SecondModule, SecondMethod->getLocation(),
+                          SecondMethod->getSourceRange(), MethodStatic)
               << SecondMethodType << SecondName << SecondStatic;
           Diagnosed = true;
           break;
@@ -10253,11 +10544,11 @@ void ASTReader::diagnoseOdrViolations() {
         const bool FirstVolatile = FirstMethod->isVolatile();
         const bool SecondVolatile = SecondMethod->isVolatile();
         if (FirstVolatile != SecondVolatile) {
-          ODRDiagError(FirstMethod->getLocation(),
-                       FirstMethod->getSourceRange(), MethodVolatile)
+          ODRDiagDeclError(FirstRecord, FirstModule, FirstMethod->getLocation(),
+                           FirstMethod->getSourceRange(), MethodVolatile)
               << FirstMethodType << FirstName << FirstVolatile;
-          ODRDiagNote(SecondMethod->getLocation(),
-                      SecondMethod->getSourceRange(), MethodVolatile)
+          ODRDiagDeclNote(SecondModule, SecondMethod->getLocation(),
+                          SecondMethod->getSourceRange(), MethodVolatile)
               << SecondMethodType << SecondName << SecondVolatile;
           Diagnosed = true;
           break;
@@ -10266,11 +10557,11 @@ void ASTReader::diagnoseOdrViolations() {
         const bool FirstConst = FirstMethod->isConst();
         const bool SecondConst = SecondMethod->isConst();
         if (FirstConst != SecondConst) {
-          ODRDiagError(FirstMethod->getLocation(),
-                       FirstMethod->getSourceRange(), MethodConst)
+          ODRDiagDeclError(FirstRecord, FirstModule, FirstMethod->getLocation(),
+                           FirstMethod->getSourceRange(), MethodConst)
               << FirstMethodType << FirstName << FirstConst;
-          ODRDiagNote(SecondMethod->getLocation(),
-                      SecondMethod->getSourceRange(), MethodConst)
+          ODRDiagDeclNote(SecondModule, SecondMethod->getLocation(),
+                          SecondMethod->getSourceRange(), MethodConst)
               << SecondMethodType << SecondName << SecondConst;
           Diagnosed = true;
           break;
@@ -10279,11 +10570,11 @@ void ASTReader::diagnoseOdrViolations() {
         const bool FirstInline = FirstMethod->isInlineSpecified();
         const bool SecondInline = SecondMethod->isInlineSpecified();
         if (FirstInline != SecondInline) {
-          ODRDiagError(FirstMethod->getLocation(),
-                       FirstMethod->getSourceRange(), MethodInline)
+          ODRDiagDeclError(FirstRecord, FirstModule, FirstMethod->getLocation(),
+                           FirstMethod->getSourceRange(), MethodInline)
               << FirstMethodType << FirstName << FirstInline;
-          ODRDiagNote(SecondMethod->getLocation(),
-                      SecondMethod->getSourceRange(), MethodInline)
+          ODRDiagDeclNote(SecondModule, SecondMethod->getLocation(),
+                          SecondMethod->getSourceRange(), MethodInline)
               << SecondMethodType << SecondName << SecondInline;
           Diagnosed = true;
           break;
@@ -10292,11 +10583,13 @@ void ASTReader::diagnoseOdrViolations() {
         const unsigned FirstNumParameters = FirstMethod->param_size();
         const unsigned SecondNumParameters = SecondMethod->param_size();
         if (FirstNumParameters != SecondNumParameters) {
-          ODRDiagError(FirstMethod->getLocation(),
-                       FirstMethod->getSourceRange(), MethodNumberParameters)
+          ODRDiagDeclError(FirstRecord, FirstModule, FirstMethod->getLocation(),
+                           FirstMethod->getSourceRange(),
+                           MethodNumberParameters)
               << FirstMethodType << FirstName << FirstNumParameters;
-          ODRDiagNote(SecondMethod->getLocation(),
-                      SecondMethod->getSourceRange(), MethodNumberParameters)
+          ODRDiagDeclNote(SecondModule, SecondMethod->getLocation(),
+                          SecondMethod->getSourceRange(),
+                          MethodNumberParameters)
               << SecondMethodType << SecondName << SecondNumParameters;
           Diagnosed = true;
           break;
@@ -10315,27 +10608,31 @@ void ASTReader::diagnoseOdrViolations() {
                   ComputeQualTypeODRHash(SecondParamType)) {
             if (const DecayedType *ParamDecayedType =
                     FirstParamType->getAs<DecayedType>()) {
-              ODRDiagError(FirstMethod->getLocation(),
-                           FirstMethod->getSourceRange(), MethodParameterType)
+              ODRDiagDeclError(
+                  FirstRecord, FirstModule, FirstMethod->getLocation(),
+                  FirstMethod->getSourceRange(), MethodParameterType)
                   << FirstMethodType << FirstName << (I + 1) << FirstParamType
                   << true << ParamDecayedType->getOriginalType();
             } else {
-              ODRDiagError(FirstMethod->getLocation(),
-                           FirstMethod->getSourceRange(), MethodParameterType)
+              ODRDiagDeclError(
+                  FirstRecord, FirstModule, FirstMethod->getLocation(),
+                  FirstMethod->getSourceRange(), MethodParameterType)
                   << FirstMethodType << FirstName << (I + 1) << FirstParamType
                   << false;
             }
 
             if (const DecayedType *ParamDecayedType =
                     SecondParamType->getAs<DecayedType>()) {
-              ODRDiagNote(SecondMethod->getLocation(),
-                          SecondMethod->getSourceRange(), MethodParameterType)
+              ODRDiagDeclNote(SecondModule, SecondMethod->getLocation(),
+                              SecondMethod->getSourceRange(),
+                              MethodParameterType)
                   << SecondMethodType << SecondName << (I + 1)
                   << SecondParamType << true
                   << ParamDecayedType->getOriginalType();
             } else {
-              ODRDiagNote(SecondMethod->getLocation(),
-                          SecondMethod->getSourceRange(), MethodParameterType)
+              ODRDiagDeclNote(SecondModule, SecondMethod->getLocation(),
+                              SecondMethod->getSourceRange(),
+                              MethodParameterType)
                   << SecondMethodType << SecondName << (I + 1)
                   << SecondParamType << false;
             }
@@ -10346,11 +10643,12 @@ void ASTReader::diagnoseOdrViolations() {
           DeclarationName FirstParamName = FirstParam->getDeclName();
           DeclarationName SecondParamName = SecondParam->getDeclName();
           if (FirstParamName != SecondParamName) {
-            ODRDiagError(FirstMethod->getLocation(),
-                         FirstMethod->getSourceRange(), MethodParameterName)
+            ODRDiagDeclError(FirstRecord, FirstModule,
+                             FirstMethod->getLocation(),
+                             FirstMethod->getSourceRange(), MethodParameterName)
                 << FirstMethodType << FirstName << (I + 1) << FirstParamName;
-            ODRDiagNote(SecondMethod->getLocation(),
-                        SecondMethod->getSourceRange(), MethodParameterName)
+            ODRDiagDeclNote(SecondModule, SecondMethod->getLocation(),
+                            SecondMethod->getSourceRange(), MethodParameterName)
                 << SecondMethodType << SecondName << (I + 1) << SecondParamName;
             ParameterMismatch = true;
             break;
@@ -10359,15 +10657,16 @@ void ASTReader::diagnoseOdrViolations() {
           const Expr *FirstInit = FirstParam->getInit();
           const Expr *SecondInit = SecondParam->getInit();
           if ((FirstInit == nullptr) != (SecondInit == nullptr)) {
-            ODRDiagError(FirstMethod->getLocation(),
-                         FirstMethod->getSourceRange(),
-                         MethodParameterSingleDefaultArgument)
+            ODRDiagDeclError(FirstRecord, FirstModule,
+                             FirstMethod->getLocation(),
+                             FirstMethod->getSourceRange(),
+                             MethodParameterSingleDefaultArgument)
                 << FirstMethodType << FirstName << (I + 1)
                 << (FirstInit == nullptr)
                 << (FirstInit ? FirstInit->getSourceRange() : SourceRange());
-            ODRDiagNote(SecondMethod->getLocation(),
-                        SecondMethod->getSourceRange(),
-                        MethodParameterSingleDefaultArgument)
+            ODRDiagDeclNote(SecondModule, SecondMethod->getLocation(),
+                            SecondMethod->getSourceRange(),
+                            MethodParameterSingleDefaultArgument)
                 << SecondMethodType << SecondName << (I + 1)
                 << (SecondInit == nullptr)
                 << (SecondInit ? SecondInit->getSourceRange() : SourceRange());
@@ -10377,14 +10676,15 @@ void ASTReader::diagnoseOdrViolations() {
 
           if (FirstInit && SecondInit &&
               ComputeODRHash(FirstInit) != ComputeODRHash(SecondInit)) {
-            ODRDiagError(FirstMethod->getLocation(),
-                         FirstMethod->getSourceRange(),
-                         MethodParameterDifferentDefaultArgument)
+            ODRDiagDeclError(FirstRecord, FirstModule,
+                             FirstMethod->getLocation(),
+                             FirstMethod->getSourceRange(),
+                             MethodParameterDifferentDefaultArgument)
                 << FirstMethodType << FirstName << (I + 1)
                 << FirstInit->getSourceRange();
-            ODRDiagNote(SecondMethod->getLocation(),
-                        SecondMethod->getSourceRange(),
-                        MethodParameterDifferentDefaultArgument)
+            ODRDiagDeclNote(SecondModule, SecondMethod->getLocation(),
+                            SecondMethod->getSourceRange(),
+                            MethodParameterDifferentDefaultArgument)
                 << SecondMethodType << SecondName << (I + 1)
                 << SecondInit->getSourceRange();
             ParameterMismatch = true;
@@ -10405,11 +10705,13 @@ void ASTReader::diagnoseOdrViolations() {
 
         if ((FirstTemplateArgs && !SecondTemplateArgs) ||
             (!FirstTemplateArgs && SecondTemplateArgs)) {
-          ODRDiagError(FirstMethod->getLocation(),
-                       FirstMethod->getSourceRange(), MethodNoTemplateArguments)
+          ODRDiagDeclError(FirstRecord, FirstModule, FirstMethod->getLocation(),
+                           FirstMethod->getSourceRange(),
+                           MethodNoTemplateArguments)
               << FirstMethodType << FirstName << (FirstTemplateArgs != nullptr);
-          ODRDiagNote(SecondMethod->getLocation(),
-                      SecondMethod->getSourceRange(), MethodNoTemplateArguments)
+          ODRDiagDeclNote(SecondModule, SecondMethod->getLocation(),
+                          SecondMethod->getSourceRange(),
+                          MethodNoTemplateArguments)
               << SecondMethodType << SecondName
               << (SecondTemplateArgs != nullptr);
 
@@ -10439,14 +10741,15 @@ void ASTReader::diagnoseOdrViolations() {
               ExpandTemplateArgumentList(SecondTemplateArgs);
 
           if (FirstExpandedList.size() != SecondExpandedList.size()) {
-            ODRDiagError(FirstMethod->getLocation(),
-                         FirstMethod->getSourceRange(),
-                         MethodDifferentNumberTemplateArguments)
+            ODRDiagDeclError(FirstRecord, FirstModule,
+                             FirstMethod->getLocation(),
+                             FirstMethod->getSourceRange(),
+                             MethodDifferentNumberTemplateArguments)
                 << FirstMethodType << FirstName
                 << (unsigned)FirstExpandedList.size();
-            ODRDiagNote(SecondMethod->getLocation(),
-                        SecondMethod->getSourceRange(),
-                        MethodDifferentNumberTemplateArguments)
+            ODRDiagDeclNote(SecondModule, SecondMethod->getLocation(),
+                            SecondMethod->getSourceRange(),
+                            MethodDifferentNumberTemplateArguments)
                 << SecondMethodType << SecondName
                 << (unsigned)SecondExpandedList.size();
 
@@ -10463,13 +10766,13 @@ void ASTReader::diagnoseOdrViolations() {
               continue;
             }
 
-            ODRDiagError(FirstMethod->getLocation(),
-                         FirstMethod->getSourceRange(),
-                         MethodDifferentTemplateArgument)
+            ODRDiagDeclError(
+                FirstRecord, FirstModule, FirstMethod->getLocation(),
+                FirstMethod->getSourceRange(), MethodDifferentTemplateArgument)
                 << FirstMethodType << FirstName << FirstTA << i + 1;
-            ODRDiagNote(SecondMethod->getLocation(),
-                        SecondMethod->getSourceRange(),
-                        MethodDifferentTemplateArgument)
+            ODRDiagDeclNote(SecondModule, SecondMethod->getLocation(),
+                            SecondMethod->getSourceRange(),
+                            MethodDifferentTemplateArgument)
                 << SecondMethodType << SecondName << SecondTA << i + 1;
 
             TemplateArgumentMismatch = true;
@@ -10498,22 +10801,22 @@ void ASTReader::diagnoseOdrViolations() {
             ComputeCXXMethodODRHash(SecondMethod) != SecondMethod->getODRHash();
 
         if (HasFirstBody != HasSecondBody) {
-          ODRDiagError(FirstMethod->getLocation(),
-                       FirstMethod->getSourceRange(), MethodSingleBody)
+          ODRDiagDeclError(FirstRecord, FirstModule, FirstMethod->getLocation(),
+                           FirstMethod->getSourceRange(), MethodSingleBody)
               << FirstMethodType << FirstName << HasFirstBody;
-          ODRDiagNote(SecondMethod->getLocation(),
-                      SecondMethod->getSourceRange(), MethodSingleBody)
+          ODRDiagDeclNote(SecondModule, SecondMethod->getLocation(),
+                          SecondMethod->getSourceRange(), MethodSingleBody)
               << SecondMethodType << SecondName << HasSecondBody;
           Diagnosed = true;
           break;
         }
 
         if (HasFirstBody && HasSecondBody) {
-          ODRDiagError(FirstMethod->getLocation(),
-                       FirstMethod->getSourceRange(), MethodDifferentBody)
+          ODRDiagDeclError(FirstRecord, FirstModule, FirstMethod->getLocation(),
+                           FirstMethod->getSourceRange(), MethodDifferentBody)
               << FirstMethodType << FirstName;
-          ODRDiagNote(SecondMethod->getLocation(),
-                      SecondMethod->getSourceRange(), MethodDifferentBody)
+          ODRDiagDeclNote(SecondModule, SecondMethod->getLocation(),
+                          SecondMethod->getSourceRange(), MethodDifferentBody)
               << SecondMethodType << SecondName;
           Diagnosed = true;
           break;
@@ -10523,105 +10826,16 @@ void ASTReader::diagnoseOdrViolations() {
       }
       case TypeAlias:
       case TypeDef: {
-        TypedefNameDecl *FirstTD = cast<TypedefNameDecl>(FirstDecl);
-        TypedefNameDecl *SecondTD = cast<TypedefNameDecl>(SecondDecl);
-        auto FirstName = FirstTD->getDeclName();
-        auto SecondName = SecondTD->getDeclName();
-        if (FirstName != SecondName) {
-          ODRDiagError(FirstTD->getLocation(), FirstTD->getSourceRange(),
-                       TypedefName)
-              << (FirstDiffType == TypeAlias) << FirstName;
-          ODRDiagNote(SecondTD->getLocation(), SecondTD->getSourceRange(),
-                      TypedefName)
-              << (FirstDiffType == TypeAlias) << SecondName;
-          Diagnosed = true;
-          break;
-        }
-
-        QualType FirstType = FirstTD->getUnderlyingType();
-        QualType SecondType = SecondTD->getUnderlyingType();
-        if (ComputeQualTypeODRHash(FirstType) !=
-            ComputeQualTypeODRHash(SecondType)) {
-          ODRDiagError(FirstTD->getLocation(), FirstTD->getSourceRange(),
-                       TypedefType)
-              << (FirstDiffType == TypeAlias) << FirstName << FirstType;
-          ODRDiagNote(SecondTD->getLocation(), SecondTD->getSourceRange(),
-                      TypedefType)
-              << (FirstDiffType == TypeAlias) << SecondName << SecondType;
-          Diagnosed = true;
-          break;
-        }
+        Diagnosed = ODRDiagTypeDefOrAlias(
+            FirstRecord, FirstModule, SecondModule,
+            cast<TypedefNameDecl>(FirstDecl), cast<TypedefNameDecl>(SecondDecl),
+            FirstDiffType == TypeAlias);
         break;
       }
       case Var: {
-        VarDecl *FirstVD = cast<VarDecl>(FirstDecl);
-        VarDecl *SecondVD = cast<VarDecl>(SecondDecl);
-        auto FirstName = FirstVD->getDeclName();
-        auto SecondName = SecondVD->getDeclName();
-        if (FirstName != SecondName) {
-          ODRDiagError(FirstVD->getLocation(), FirstVD->getSourceRange(),
-                       VarName)
-              << FirstName;
-          ODRDiagNote(SecondVD->getLocation(), SecondVD->getSourceRange(),
-                      VarName)
-              << SecondName;
-          Diagnosed = true;
-          break;
-        }
-
-        QualType FirstType = FirstVD->getType();
-        QualType SecondType = SecondVD->getType();
-        if (ComputeQualTypeODRHash(FirstType) !=
-                        ComputeQualTypeODRHash(SecondType)) {
-          ODRDiagError(FirstVD->getLocation(), FirstVD->getSourceRange(),
-                       VarType)
-              << FirstName << FirstType;
-          ODRDiagNote(SecondVD->getLocation(), SecondVD->getSourceRange(),
-                      VarType)
-              << SecondName << SecondType;
-          Diagnosed = true;
-          break;
-        }
-
-        const Expr *FirstInit = FirstVD->getInit();
-        const Expr *SecondInit = SecondVD->getInit();
-        if ((FirstInit == nullptr) != (SecondInit == nullptr)) {
-          ODRDiagError(FirstVD->getLocation(), FirstVD->getSourceRange(),
-                       VarSingleInitializer)
-              << FirstName << (FirstInit == nullptr)
-              << (FirstInit ? FirstInit->getSourceRange(): SourceRange());
-          ODRDiagNote(SecondVD->getLocation(), SecondVD->getSourceRange(),
-                      VarSingleInitializer)
-              << SecondName << (SecondInit == nullptr)
-              << (SecondInit ? SecondInit->getSourceRange() : SourceRange());
-          Diagnosed = true;
-          break;
-        }
-
-        if (FirstInit && SecondInit &&
-            ComputeODRHash(FirstInit) != ComputeODRHash(SecondInit)) {
-          ODRDiagError(FirstVD->getLocation(), FirstVD->getSourceRange(),
-                       VarDifferentInitializer)
-              << FirstName << FirstInit->getSourceRange();
-          ODRDiagNote(SecondVD->getLocation(), SecondVD->getSourceRange(),
-                      VarDifferentInitializer)
-              << SecondName << SecondInit->getSourceRange();
-          Diagnosed = true;
-          break;
-        }
-
-        const bool FirstIsConstexpr = FirstVD->isConstexpr();
-        const bool SecondIsConstexpr = SecondVD->isConstexpr();
-        if (FirstIsConstexpr != SecondIsConstexpr) {
-          ODRDiagError(FirstVD->getLocation(), FirstVD->getSourceRange(),
-                       VarConstexpr)
-              << FirstName << FirstIsConstexpr;
-          ODRDiagNote(SecondVD->getLocation(), SecondVD->getSourceRange(),
-                      VarConstexpr)
-              << SecondName << SecondIsConstexpr;
-          Diagnosed = true;
-          break;
-        }
+        Diagnosed =
+            ODRDiagVar(FirstRecord, FirstModule, SecondModule,
+                       cast<VarDecl>(FirstDecl), cast<VarDecl>(SecondDecl));
         break;
       }
       case Friend: {
@@ -10635,11 +10849,12 @@ void ASTReader::diagnoseOdrViolations() {
         TypeSourceInfo *SecondTSI = SecondFriend->getFriendType();
 
         if (FirstND && SecondND) {
-          ODRDiagError(FirstFriend->getFriendLoc(),
-                       FirstFriend->getSourceRange(), FriendFunction)
+          ODRDiagDeclError(FirstRecord, FirstModule,
+                           FirstFriend->getFriendLoc(),
+                           FirstFriend->getSourceRange(), FriendFunction)
               << FirstND;
-          ODRDiagNote(SecondFriend->getFriendLoc(),
-                      SecondFriend->getSourceRange(), FriendFunction)
+          ODRDiagDeclNote(SecondModule, SecondFriend->getFriendLoc(),
+                          SecondFriend->getSourceRange(), FriendFunction)
               << SecondND;
 
           Diagnosed = true;
@@ -10651,21 +10866,22 @@ void ASTReader::diagnoseOdrViolations() {
           QualType SecondFriendType = SecondTSI->getType();
           assert(ComputeQualTypeODRHash(FirstFriendType) !=
                  ComputeQualTypeODRHash(SecondFriendType));
-          ODRDiagError(FirstFriend->getFriendLoc(),
-                       FirstFriend->getSourceRange(), FriendType)
+          ODRDiagDeclError(FirstRecord, FirstModule,
+                           FirstFriend->getFriendLoc(),
+                           FirstFriend->getSourceRange(), FriendType)
               << FirstFriendType;
-          ODRDiagNote(SecondFriend->getFriendLoc(),
-                      SecondFriend->getSourceRange(), FriendType)
+          ODRDiagDeclNote(SecondModule, SecondFriend->getFriendLoc(),
+                          SecondFriend->getSourceRange(), FriendType)
               << SecondFriendType;
           Diagnosed = true;
           break;
         }
 
-        ODRDiagError(FirstFriend->getFriendLoc(), FirstFriend->getSourceRange(),
-                     FriendTypeFunction)
+        ODRDiagDeclError(FirstRecord, FirstModule, FirstFriend->getFriendLoc(),
+                         FirstFriend->getSourceRange(), FriendTypeFunction)
             << (FirstTSI == nullptr);
-        ODRDiagNote(SecondFriend->getFriendLoc(),
-                    SecondFriend->getSourceRange(), FriendTypeFunction)
+        ODRDiagDeclNote(SecondModule, SecondFriend->getFriendLoc(),
+                        SecondFriend->getSourceRange(), FriendTypeFunction)
             << (SecondTSI == nullptr);
 
         Diagnosed = true;
@@ -10683,14 +10899,15 @@ void ASTReader::diagnoseOdrViolations() {
             SecondTemplate->getTemplateParameters();
 
         if (FirstTPL->size() != SecondTPL->size()) {
-          ODRDiagError(FirstTemplate->getLocation(),
-                       FirstTemplate->getSourceRange(),
-                       FunctionTemplateDifferentNumberParameters)
+          ODRDiagDeclError(FirstRecord, FirstModule,
+                           FirstTemplate->getLocation(),
+                           FirstTemplate->getSourceRange(),
+                           FunctionTemplateDifferentNumberParameters)
               << FirstTemplate << FirstTPL->size();
-          ODRDiagNote(SecondTemplate->getLocation(),
-                      SecondTemplate->getSourceRange(),
-                      FunctionTemplateDifferentNumberParameters)
-              << SecondTemplate  << SecondTPL->size();
+          ODRDiagDeclNote(SecondModule, SecondTemplate->getLocation(),
+                          SecondTemplate->getSourceRange(),
+                          FunctionTemplateDifferentNumberParameters)
+              << SecondTemplate << SecondTPL->size();
 
           Diagnosed = true;
           break;
@@ -10720,13 +10937,14 @@ void ASTReader::diagnoseOdrViolations() {
               }
             };
 
-            ODRDiagError(FirstTemplate->getLocation(),
-                         FirstTemplate->getSourceRange(),
-                         FunctionTemplateParameterDifferentKind)
+            ODRDiagDeclError(FirstRecord, FirstModule,
+                             FirstTemplate->getLocation(),
+                             FirstTemplate->getSourceRange(),
+                             FunctionTemplateParameterDifferentKind)
                 << FirstTemplate << (i + 1) << GetParamType(FirstParam);
-            ODRDiagNote(SecondTemplate->getLocation(),
-                        SecondTemplate->getSourceRange(),
-                        FunctionTemplateParameterDifferentKind)
+            ODRDiagDeclNote(SecondModule, SecondTemplate->getLocation(),
+                            SecondTemplate->getSourceRange(),
+                            FunctionTemplateParameterDifferentKind)
                 << SecondTemplate << (i + 1) << GetParamType(SecondParam);
 
             ParameterMismatch = true;
@@ -10734,14 +10952,14 @@ void ASTReader::diagnoseOdrViolations() {
           }
 
           if (FirstParam->getName() != SecondParam->getName()) {
-            ODRDiagError(FirstTemplate->getLocation(),
-                         FirstTemplate->getSourceRange(),
-                         FunctionTemplateParameterName)
+            ODRDiagDeclError(
+                FirstRecord, FirstModule, FirstTemplate->getLocation(),
+                FirstTemplate->getSourceRange(), FunctionTemplateParameterName)
                 << FirstTemplate << (i + 1) << (bool)FirstParam->getIdentifier()
                 << FirstParam;
-            ODRDiagNote(SecondTemplate->getLocation(),
-                        SecondTemplate->getSourceRange(),
-                        FunctionTemplateParameterName)
+            ODRDiagDeclNote(SecondModule, SecondTemplate->getLocation(),
+                            SecondTemplate->getSourceRange(),
+                            FunctionTemplateParameterName)
                 << SecondTemplate << (i + 1)
                 << (bool)SecondParam->getIdentifier() << SecondParam;
             ParameterMismatch = true;
@@ -10761,13 +10979,14 @@ void ASTReader::diagnoseOdrViolations() {
                 SecondTTPD->hasDefaultArgument() &&
                 !SecondTTPD->defaultArgumentWasInherited();
             if (HasFirstDefaultArgument != HasSecondDefaultArgument) {
-              ODRDiagError(FirstTemplate->getLocation(),
-                           FirstTemplate->getSourceRange(),
-                           FunctionTemplateParameterSingleDefaultArgument)
+              ODRDiagDeclError(FirstRecord, FirstModule,
+                               FirstTemplate->getLocation(),
+                               FirstTemplate->getSourceRange(),
+                               FunctionTemplateParameterSingleDefaultArgument)
                   << FirstTemplate << (i + 1) << HasFirstDefaultArgument;
-              ODRDiagNote(SecondTemplate->getLocation(),
-                          SecondTemplate->getSourceRange(),
-                          FunctionTemplateParameterSingleDefaultArgument)
+              ODRDiagDeclNote(SecondModule, SecondTemplate->getLocation(),
+                              SecondTemplate->getSourceRange(),
+                              FunctionTemplateParameterSingleDefaultArgument)
                   << SecondTemplate << (i + 1) << HasSecondDefaultArgument;
               ParameterMismatch = true;
               break;
@@ -10778,13 +10997,15 @@ void ASTReader::diagnoseOdrViolations() {
               QualType SecondType = SecondTTPD->getDefaultArgument();
               if (ComputeQualTypeODRHash(FirstType) !=
                   ComputeQualTypeODRHash(SecondType)) {
-                ODRDiagError(FirstTemplate->getLocation(),
-                             FirstTemplate->getSourceRange(),
-                             FunctionTemplateParameterDifferentDefaultArgument)
+                ODRDiagDeclError(
+                    FirstRecord, FirstModule, FirstTemplate->getLocation(),
+                    FirstTemplate->getSourceRange(),
+                    FunctionTemplateParameterDifferentDefaultArgument)
                     << FirstTemplate << (i + 1) << FirstType;
-                ODRDiagNote(SecondTemplate->getLocation(),
-                            SecondTemplate->getSourceRange(),
-                            FunctionTemplateParameterDifferentDefaultArgument)
+                ODRDiagDeclNote(
+                    SecondModule, SecondTemplate->getLocation(),
+                    SecondTemplate->getSourceRange(),
+                    FunctionTemplateParameterDifferentDefaultArgument)
                     << SecondTemplate << (i + 1) << SecondType;
                 ParameterMismatch = true;
                 break;
@@ -10793,13 +11014,14 @@ void ASTReader::diagnoseOdrViolations() {
 
             if (FirstTTPD->isParameterPack() !=
                 SecondTTPD->isParameterPack()) {
-              ODRDiagError(FirstTemplate->getLocation(),
-                           FirstTemplate->getSourceRange(),
-                           FunctionTemplatePackParameter)
+              ODRDiagDeclError(FirstRecord, FirstModule,
+                               FirstTemplate->getLocation(),
+                               FirstTemplate->getSourceRange(),
+                               FunctionTemplatePackParameter)
                   << FirstTemplate << (i + 1) << FirstTTPD->isParameterPack();
-              ODRDiagNote(SecondTemplate->getLocation(),
-                          SecondTemplate->getSourceRange(),
-                          FunctionTemplatePackParameter)
+              ODRDiagDeclNote(SecondModule, SecondTemplate->getLocation(),
+                              SecondTemplate->getSourceRange(),
+                              FunctionTemplatePackParameter)
                   << SecondTemplate << (i + 1) << SecondTTPD->isParameterPack();
               ParameterMismatch = true;
               break;
@@ -10820,13 +11042,14 @@ void ASTReader::diagnoseOdrViolations() {
 
             if (ComputeTemplateParameterListODRHash(FirstTPL) !=
                 ComputeTemplateParameterListODRHash(SecondTPL)) {
-              ODRDiagError(FirstTemplate->getLocation(),
-                           FirstTemplate->getSourceRange(),
-                           FunctionTemplateParameterDifferentType)
+              ODRDiagDeclError(FirstRecord, FirstModule,
+                               FirstTemplate->getLocation(),
+                               FirstTemplate->getSourceRange(),
+                               FunctionTemplateParameterDifferentType)
                   << FirstTemplate << (i + 1);
-              ODRDiagNote(SecondTemplate->getLocation(),
-                          SecondTemplate->getSourceRange(),
-                          FunctionTemplateParameterDifferentType)
+              ODRDiagDeclNote(SecondModule, SecondTemplate->getLocation(),
+                              SecondTemplate->getSourceRange(),
+                              FunctionTemplateParameterDifferentType)
                   << SecondTemplate << (i + 1);
               ParameterMismatch = true;
               break;
@@ -10839,13 +11062,14 @@ void ASTReader::diagnoseOdrViolations() {
                 SecondTTPD->hasDefaultArgument() &&
                 !SecondTTPD->defaultArgumentWasInherited();
             if (HasFirstDefaultArgument != HasSecondDefaultArgument) {
-              ODRDiagError(FirstTemplate->getLocation(),
-                           FirstTemplate->getSourceRange(),
-                           FunctionTemplateParameterSingleDefaultArgument)
+              ODRDiagDeclError(FirstRecord, FirstModule,
+                               FirstTemplate->getLocation(),
+                               FirstTemplate->getSourceRange(),
+                               FunctionTemplateParameterSingleDefaultArgument)
                   << FirstTemplate << (i + 1) << HasFirstDefaultArgument;
-              ODRDiagNote(SecondTemplate->getLocation(),
-                          SecondTemplate->getSourceRange(),
-                          FunctionTemplateParameterSingleDefaultArgument)
+              ODRDiagDeclNote(SecondModule, SecondTemplate->getLocation(),
+                              SecondTemplate->getSourceRange(),
+                              FunctionTemplateParameterSingleDefaultArgument)
                   << SecondTemplate << (i + 1) << HasSecondDefaultArgument;
               ParameterMismatch = true;
               break;
@@ -10858,13 +11082,15 @@ void ASTReader::diagnoseOdrViolations() {
                   SecondTTPD->getDefaultArgument().getArgument();
               if (ComputeTemplateArgumentODRHash(FirstTA) !=
                   ComputeTemplateArgumentODRHash(SecondTA)) {
-                ODRDiagError(FirstTemplate->getLocation(),
-                             FirstTemplate->getSourceRange(),
-                             FunctionTemplateParameterDifferentDefaultArgument)
+                ODRDiagDeclError(
+                    FirstRecord, FirstModule, FirstTemplate->getLocation(),
+                    FirstTemplate->getSourceRange(),
+                    FunctionTemplateParameterDifferentDefaultArgument)
                     << FirstTemplate << (i + 1) << FirstTA;
-                ODRDiagNote(SecondTemplate->getLocation(),
-                            SecondTemplate->getSourceRange(),
-                            FunctionTemplateParameterDifferentDefaultArgument)
+                ODRDiagDeclNote(
+                    SecondModule, SecondTemplate->getLocation(),
+                    SecondTemplate->getSourceRange(),
+                    FunctionTemplateParameterDifferentDefaultArgument)
                     << SecondTemplate << (i + 1) << SecondTA;
                 ParameterMismatch = true;
                 break;
@@ -10873,13 +11099,14 @@ void ASTReader::diagnoseOdrViolations() {
 
             if (FirstTTPD->isParameterPack() !=
                 SecondTTPD->isParameterPack()) {
-              ODRDiagError(FirstTemplate->getLocation(),
-                           FirstTemplate->getSourceRange(),
-                           FunctionTemplatePackParameter)
+              ODRDiagDeclError(FirstRecord, FirstModule,
+                               FirstTemplate->getLocation(),
+                               FirstTemplate->getSourceRange(),
+                               FunctionTemplatePackParameter)
                   << FirstTemplate << (i + 1) << FirstTTPD->isParameterPack();
-              ODRDiagNote(SecondTemplate->getLocation(),
-                          SecondTemplate->getSourceRange(),
-                          FunctionTemplatePackParameter)
+              ODRDiagDeclNote(SecondModule, SecondTemplate->getLocation(),
+                              SecondTemplate->getSourceRange(),
+                              FunctionTemplatePackParameter)
                   << SecondTemplate << (i + 1) << SecondTTPD->isParameterPack();
               ParameterMismatch = true;
               break;
@@ -10897,13 +11124,14 @@ void ASTReader::diagnoseOdrViolations() {
             QualType SecondType = SecondNTTPD->getType();
             if (ComputeQualTypeODRHash(FirstType) !=
                 ComputeQualTypeODRHash(SecondType)) {
-              ODRDiagError(FirstTemplate->getLocation(),
-                           FirstTemplate->getSourceRange(),
-                           FunctionTemplateParameterDifferentType)
+              ODRDiagDeclError(FirstRecord, FirstModule,
+                               FirstTemplate->getLocation(),
+                               FirstTemplate->getSourceRange(),
+                               FunctionTemplateParameterDifferentType)
                   << FirstTemplate << (i + 1);
-              ODRDiagNote(SecondTemplate->getLocation(),
-                          SecondTemplate->getSourceRange(),
-                          FunctionTemplateParameterDifferentType)
+              ODRDiagDeclNote(SecondModule, SecondTemplate->getLocation(),
+                              SecondTemplate->getSourceRange(),
+                              FunctionTemplateParameterDifferentType)
                   << SecondTemplate << (i + 1);
               ParameterMismatch = true;
               break;
@@ -10916,13 +11144,14 @@ void ASTReader::diagnoseOdrViolations() {
                 SecondNTTPD->hasDefaultArgument() &&
                 !SecondNTTPD->defaultArgumentWasInherited();
             if (HasFirstDefaultArgument != HasSecondDefaultArgument) {
-              ODRDiagError(FirstTemplate->getLocation(),
-                           FirstTemplate->getSourceRange(),
-                           FunctionTemplateParameterSingleDefaultArgument)
+              ODRDiagDeclError(FirstRecord, FirstModule,
+                               FirstTemplate->getLocation(),
+                               FirstTemplate->getSourceRange(),
+                               FunctionTemplateParameterSingleDefaultArgument)
                   << FirstTemplate << (i + 1) << HasFirstDefaultArgument;
-              ODRDiagNote(SecondTemplate->getLocation(),
-                          SecondTemplate->getSourceRange(),
-                          FunctionTemplateParameterSingleDefaultArgument)
+              ODRDiagDeclNote(SecondModule, SecondTemplate->getLocation(),
+                              SecondTemplate->getSourceRange(),
+                              FunctionTemplateParameterSingleDefaultArgument)
                   << SecondTemplate << (i + 1) << HasSecondDefaultArgument;
               ParameterMismatch = true;
               break;
@@ -10933,13 +11162,15 @@ void ASTReader::diagnoseOdrViolations() {
               Expr *SecondDefaultArgument = SecondNTTPD->getDefaultArgument();
               if (ComputeODRHash(FirstDefaultArgument) !=
                   ComputeODRHash(SecondDefaultArgument)) {
-                ODRDiagError(FirstTemplate->getLocation(),
-                             FirstTemplate->getSourceRange(),
-                             FunctionTemplateParameterDifferentDefaultArgument)
+                ODRDiagDeclError(
+                    FirstRecord, FirstModule, FirstTemplate->getLocation(),
+                    FirstTemplate->getSourceRange(),
+                    FunctionTemplateParameterDifferentDefaultArgument)
                     << FirstTemplate << (i + 1) << FirstDefaultArgument;
-                ODRDiagNote(SecondTemplate->getLocation(),
-                            SecondTemplate->getSourceRange(),
-                            FunctionTemplateParameterDifferentDefaultArgument)
+                ODRDiagDeclNote(
+                    SecondModule, SecondTemplate->getLocation(),
+                    SecondTemplate->getSourceRange(),
+                    FunctionTemplateParameterDifferentDefaultArgument)
                     << SecondTemplate << (i + 1) << SecondDefaultArgument;
                 ParameterMismatch = true;
                 break;
@@ -10948,13 +11179,14 @@ void ASTReader::diagnoseOdrViolations() {
 
             if (FirstNTTPD->isParameterPack() !=
                 SecondNTTPD->isParameterPack()) {
-              ODRDiagError(FirstTemplate->getLocation(),
-                           FirstTemplate->getSourceRange(),
-                           FunctionTemplatePackParameter)
+              ODRDiagDeclError(FirstRecord, FirstModule,
+                               FirstTemplate->getLocation(),
+                               FirstTemplate->getSourceRange(),
+                               FunctionTemplatePackParameter)
                   << FirstTemplate << (i + 1) << FirstNTTPD->isParameterPack();
-              ODRDiagNote(SecondTemplate->getLocation(),
-                          SecondTemplate->getSourceRange(),
-                          FunctionTemplatePackParameter)
+              ODRDiagDeclNote(SecondModule, SecondTemplate->getLocation(),
+                              SecondTemplate->getSourceRange(),
+                              FunctionTemplatePackParameter)
                   << SecondTemplate << (i + 1)
                   << SecondNTTPD->isParameterPack();
               ParameterMismatch = true;
@@ -11181,7 +11413,7 @@ void ASTReader::diagnoseOdrViolations() {
       for (auto *D : Enum->decls()) {
         // Due to decl merging, the first EnumDecl is the parent of
         // Decls in both records.
-        if (!ODRHash::isWhitelistedDecl(D, FirstEnum))
+        if (!ODRHash::isDeclToBeProcessed(D, FirstEnum))
           continue;
         assert(isa<EnumConstantDecl>(D) && "Unexpected Decl kind");
         Hashes.emplace_back(cast<EnumConstantDecl>(D),
@@ -11494,8 +11726,8 @@ public:
   OMPClauseReader(ASTRecordReader &Record)
       : Record(Record), Context(Record.getContext()) {}
 
-#define OPENMP_CLAUSE(Name, Class) void Visit##Class(Class *C);
-#include "clang/Basic/OpenMPKinds.def"
+#define OMP_CLAUSE_CLASS(Enum, Str, Class) void Visit##Class(Class *C);
+#include "llvm/Frontend/OpenMP/OMPKinds.def"
   OMPClause *readClause();
   void VisitOMPClauseWithPreInit(OMPClauseWithPreInit *C);
   void VisitOMPClauseWithPostUpdate(OMPClauseWithPostUpdate *C);
@@ -11509,134 +11741,152 @@ OMPClause *ASTRecordReader::readOMPClause() {
 
 OMPClause *OMPClauseReader::readClause() {
   OMPClause *C = nullptr;
-  switch (Record.readInt()) {
-  case OMPC_if:
+  switch (llvm::omp::Clause(Record.readInt())) {
+  case llvm::omp::OMPC_if:
     C = new (Context) OMPIfClause();
     break;
-  case OMPC_final:
+  case llvm::omp::OMPC_final:
     C = new (Context) OMPFinalClause();
     break;
-  case OMPC_num_threads:
+  case llvm::omp::OMPC_num_threads:
     C = new (Context) OMPNumThreadsClause();
     break;
-  case OMPC_safelen:
+  case llvm::omp::OMPC_safelen:
     C = new (Context) OMPSafelenClause();
     break;
-  case OMPC_simdlen:
+  case llvm::omp::OMPC_simdlen:
     C = new (Context) OMPSimdlenClause();
     break;
-  case OMPC_allocator:
+  case llvm::omp::OMPC_allocator:
     C = new (Context) OMPAllocatorClause();
     break;
-  case OMPC_collapse:
+  case llvm::omp::OMPC_collapse:
     C = new (Context) OMPCollapseClause();
     break;
-  case OMPC_default:
+  case llvm::omp::OMPC_default:
     C = new (Context) OMPDefaultClause();
     break;
-  case OMPC_proc_bind:
+  case llvm::omp::OMPC_proc_bind:
     C = new (Context) OMPProcBindClause();
     break;
-  case OMPC_schedule:
+  case llvm::omp::OMPC_schedule:
     C = new (Context) OMPScheduleClause();
     break;
-  case OMPC_ordered:
+  case llvm::omp::OMPC_ordered:
     C = OMPOrderedClause::CreateEmpty(Context, Record.readInt());
     break;
-  case OMPC_nowait:
+  case llvm::omp::OMPC_nowait:
     C = new (Context) OMPNowaitClause();
     break;
-  case OMPC_untied:
+  case llvm::omp::OMPC_untied:
     C = new (Context) OMPUntiedClause();
     break;
-  case OMPC_mergeable:
+  case llvm::omp::OMPC_mergeable:
     C = new (Context) OMPMergeableClause();
     break;
-  case OMPC_read:
+  case llvm::omp::OMPC_read:
     C = new (Context) OMPReadClause();
     break;
-  case OMPC_write:
+  case llvm::omp::OMPC_write:
     C = new (Context) OMPWriteClause();
     break;
-  case OMPC_update:
-    C = new (Context) OMPUpdateClause();
+  case llvm::omp::OMPC_update:
+    C = OMPUpdateClause::CreateEmpty(Context, Record.readInt());
     break;
-  case OMPC_capture:
+  case llvm::omp::OMPC_capture:
     C = new (Context) OMPCaptureClause();
     break;
-  case OMPC_seq_cst:
+  case llvm::omp::OMPC_seq_cst:
     C = new (Context) OMPSeqCstClause();
     break;
-  case OMPC_threads:
+  case llvm::omp::OMPC_acq_rel:
+    C = new (Context) OMPAcqRelClause();
+    break;
+  case llvm::omp::OMPC_acquire:
+    C = new (Context) OMPAcquireClause();
+    break;
+  case llvm::omp::OMPC_release:
+    C = new (Context) OMPReleaseClause();
+    break;
+  case llvm::omp::OMPC_relaxed:
+    C = new (Context) OMPRelaxedClause();
+    break;
+  case llvm::omp::OMPC_threads:
     C = new (Context) OMPThreadsClause();
     break;
-  case OMPC_simd:
+  case llvm::omp::OMPC_simd:
     C = new (Context) OMPSIMDClause();
     break;
-  case OMPC_nogroup:
+  case llvm::omp::OMPC_nogroup:
     C = new (Context) OMPNogroupClause();
     break;
-  case OMPC_unified_address:
+  case llvm::omp::OMPC_unified_address:
     C = new (Context) OMPUnifiedAddressClause();
     break;
-  case OMPC_unified_shared_memory:
+  case llvm::omp::OMPC_unified_shared_memory:
     C = new (Context) OMPUnifiedSharedMemoryClause();
     break;
-  case OMPC_reverse_offload:
+  case llvm::omp::OMPC_reverse_offload:
     C = new (Context) OMPReverseOffloadClause();
     break;
-  case OMPC_dynamic_allocators:
+  case llvm::omp::OMPC_dynamic_allocators:
     C = new (Context) OMPDynamicAllocatorsClause();
     break;
-  case OMPC_atomic_default_mem_order:
+  case llvm::omp::OMPC_atomic_default_mem_order:
     C = new (Context) OMPAtomicDefaultMemOrderClause();
     break;
- case OMPC_private:
+ case llvm::omp::OMPC_private:
     C = OMPPrivateClause::CreateEmpty(Context, Record.readInt());
     break;
-  case OMPC_firstprivate:
+  case llvm::omp::OMPC_firstprivate:
     C = OMPFirstprivateClause::CreateEmpty(Context, Record.readInt());
     break;
-  case OMPC_lastprivate:
+  case llvm::omp::OMPC_lastprivate:
     C = OMPLastprivateClause::CreateEmpty(Context, Record.readInt());
     break;
-  case OMPC_shared:
+  case llvm::omp::OMPC_shared:
     C = OMPSharedClause::CreateEmpty(Context, Record.readInt());
     break;
-  case OMPC_reduction:
-    C = OMPReductionClause::CreateEmpty(Context, Record.readInt());
+  case llvm::omp::OMPC_reduction: {
+    unsigned N = Record.readInt();
+    auto Modifier = Record.readEnum<OpenMPReductionClauseModifier>();
+    C = OMPReductionClause::CreateEmpty(Context, N, Modifier);
     break;
-  case OMPC_task_reduction:
+  }
+  case llvm::omp::OMPC_task_reduction:
     C = OMPTaskReductionClause::CreateEmpty(Context, Record.readInt());
     break;
-  case OMPC_in_reduction:
+  case llvm::omp::OMPC_in_reduction:
     C = OMPInReductionClause::CreateEmpty(Context, Record.readInt());
     break;
-  case OMPC_linear:
+  case llvm::omp::OMPC_linear:
     C = OMPLinearClause::CreateEmpty(Context, Record.readInt());
     break;
-  case OMPC_aligned:
+  case llvm::omp::OMPC_aligned:
     C = OMPAlignedClause::CreateEmpty(Context, Record.readInt());
     break;
-  case OMPC_copyin:
+  case llvm::omp::OMPC_copyin:
     C = OMPCopyinClause::CreateEmpty(Context, Record.readInt());
     break;
-  case OMPC_copyprivate:
+  case llvm::omp::OMPC_copyprivate:
     C = OMPCopyprivateClause::CreateEmpty(Context, Record.readInt());
     break;
-  case OMPC_flush:
+  case llvm::omp::OMPC_flush:
     C = OMPFlushClause::CreateEmpty(Context, Record.readInt());
     break;
-  case OMPC_depend: {
+  case llvm::omp::OMPC_depobj:
+    C = OMPDepobjClause::CreateEmpty(Context);
+    break;
+  case llvm::omp::OMPC_depend: {
     unsigned NumVars = Record.readInt();
     unsigned NumLoops = Record.readInt();
     C = OMPDependClause::CreateEmpty(Context, NumVars, NumLoops);
     break;
   }
-  case OMPC_device:
+  case llvm::omp::OMPC_device:
     C = new (Context) OMPDeviceClause();
     break;
-  case OMPC_map: {
+  case llvm::omp::OMPC_map: {
     OMPMappableExprListSizeTy Sizes;
     Sizes.NumVars = Record.readInt();
     Sizes.NumUniqueDeclarations = Record.readInt();
@@ -11645,31 +11895,31 @@ OMPClause *OMPClauseReader::readClause() {
     C = OMPMapClause::CreateEmpty(Context, Sizes);
     break;
   }
-  case OMPC_num_teams:
+  case llvm::omp::OMPC_num_teams:
     C = new (Context) OMPNumTeamsClause();
     break;
-  case OMPC_thread_limit:
+  case llvm::omp::OMPC_thread_limit:
     C = new (Context) OMPThreadLimitClause();
     break;
-  case OMPC_priority:
+  case llvm::omp::OMPC_priority:
     C = new (Context) OMPPriorityClause();
     break;
-  case OMPC_grainsize:
+  case llvm::omp::OMPC_grainsize:
     C = new (Context) OMPGrainsizeClause();
     break;
-  case OMPC_num_tasks:
+  case llvm::omp::OMPC_num_tasks:
     C = new (Context) OMPNumTasksClause();
     break;
-  case OMPC_hint:
+  case llvm::omp::OMPC_hint:
     C = new (Context) OMPHintClause();
     break;
-  case OMPC_dist_schedule:
+  case llvm::omp::OMPC_dist_schedule:
     C = new (Context) OMPDistScheduleClause();
     break;
-  case OMPC_defaultmap:
+  case llvm::omp::OMPC_defaultmap:
     C = new (Context) OMPDefaultmapClause();
     break;
-  case OMPC_to: {
+  case llvm::omp::OMPC_to: {
     OMPMappableExprListSizeTy Sizes;
     Sizes.NumVars = Record.readInt();
     Sizes.NumUniqueDeclarations = Record.readInt();
@@ -11678,7 +11928,7 @@ OMPClause *OMPClauseReader::readClause() {
     C = OMPToClause::CreateEmpty(Context, Sizes);
     break;
   }
-  case OMPC_from: {
+  case llvm::omp::OMPC_from: {
     OMPMappableExprListSizeTy Sizes;
     Sizes.NumVars = Record.readInt();
     Sizes.NumUniqueDeclarations = Record.readInt();
@@ -11687,7 +11937,7 @@ OMPClause *OMPClauseReader::readClause() {
     C = OMPFromClause::CreateEmpty(Context, Sizes);
     break;
   }
-  case OMPC_use_device_ptr: {
+  case llvm::omp::OMPC_use_device_ptr: {
     OMPMappableExprListSizeTy Sizes;
     Sizes.NumVars = Record.readInt();
     Sizes.NumUniqueDeclarations = Record.readInt();
@@ -11696,7 +11946,16 @@ OMPClause *OMPClauseReader::readClause() {
     C = OMPUseDevicePtrClause::CreateEmpty(Context, Sizes);
     break;
   }
-  case OMPC_is_device_ptr: {
+  case llvm::omp::OMPC_use_device_addr: {
+    OMPMappableExprListSizeTy Sizes;
+    Sizes.NumVars = Record.readInt();
+    Sizes.NumUniqueDeclarations = Record.readInt();
+    Sizes.NumComponentLists = Record.readInt();
+    Sizes.NumComponents = Record.readInt();
+    C = OMPUseDeviceAddrClause::CreateEmpty(Context, Sizes);
+    break;
+  }
+  case llvm::omp::OMPC_is_device_ptr: {
     OMPMappableExprListSizeTy Sizes;
     Sizes.NumVars = Record.readInt();
     Sizes.NumUniqueDeclarations = Record.readInt();
@@ -11705,12 +11964,39 @@ OMPClause *OMPClauseReader::readClause() {
     C = OMPIsDevicePtrClause::CreateEmpty(Context, Sizes);
     break;
   }
-  case OMPC_allocate:
+  case llvm::omp::OMPC_allocate:
     C = OMPAllocateClause::CreateEmpty(Context, Record.readInt());
     break;
-  case OMPC_nontemporal:
+  case llvm::omp::OMPC_nontemporal:
     C = OMPNontemporalClause::CreateEmpty(Context, Record.readInt());
     break;
+  case llvm::omp::OMPC_inclusive:
+    C = OMPInclusiveClause::CreateEmpty(Context, Record.readInt());
+    break;
+  case llvm::omp::OMPC_exclusive:
+    C = OMPExclusiveClause::CreateEmpty(Context, Record.readInt());
+    break;
+  case llvm::omp::OMPC_order:
+    C = new (Context) OMPOrderClause();
+    break;
+  case llvm::omp::OMPC_destroy:
+    C = new (Context) OMPDestroyClause();
+    break;
+  case llvm::omp::OMPC_detach:
+    C = new (Context) OMPDetachClause();
+    break;
+  case llvm::omp::OMPC_uses_allocators:
+    C = OMPUsesAllocatorsClause::CreateEmpty(Context, Record.readInt());
+    break;
+  case llvm::omp::OMPC_affinity:
+    C = OMPAffinityClause::CreateEmpty(Context, Record.readInt());
+    break;
+#define OMP_CLAUSE_NO_CLASS(Enum, Str)                                         \
+  case llvm::omp::Enum:                                                        \
+    break;
+#include "llvm/Frontend/OpenMP/OMPKinds.def"
+  default:
+    break;
   }
   assert(C && "Unknown OMPClause type");
 
@@ -11773,8 +12059,7 @@ void OMPClauseReader::VisitOMPCollapseClause(OMPCollapseClause *C) {
 }
 
 void OMPClauseReader::VisitOMPDefaultClause(OMPDefaultClause *C) {
-  C->setDefaultKind(
-       static_cast<OpenMPDefaultClauseKind>(Record.readInt()));
+  C->setDefaultKind(static_cast<llvm::omp::DefaultKind>(Record.readInt()));
   C->setLParenLoc(Record.readSourceLocation());
   C->setDefaultKindKwLoc(Record.readSourceLocation());
 }
@@ -11810,6 +12095,11 @@ void OMPClauseReader::VisitOMPOrderedClause(OMPOrderedClause *C) {
   C->setLParenLoc(Record.readSourceLocation());
 }
 
+void OMPClauseReader::VisitOMPDetachClause(OMPDetachClause *C) {
+  C->setEventHandler(Record.readSubExpr());
+  C->setLParenLoc(Record.readSourceLocation());
+}
+
 void OMPClauseReader::VisitOMPNowaitClause(OMPNowaitClause *) {}
 
 void OMPClauseReader::VisitOMPUntiedClause(OMPUntiedClause *) {}
@@ -11820,18 +12110,34 @@ void OMPClauseReader::VisitOMPReadClause(OMPReadClause *) {}
 
 void OMPClauseReader::VisitOMPWriteClause(OMPWriteClause *) {}
 
-void OMPClauseReader::VisitOMPUpdateClause(OMPUpdateClause *) {}
+void OMPClauseReader::VisitOMPUpdateClause(OMPUpdateClause *C) {
+  if (C->isExtended()) {
+    C->setLParenLoc(Record.readSourceLocation());
+    C->setArgumentLoc(Record.readSourceLocation());
+    C->setDependencyKind(Record.readEnum<OpenMPDependClauseKind>());
+  }
+}
 
 void OMPClauseReader::VisitOMPCaptureClause(OMPCaptureClause *) {}
 
 void OMPClauseReader::VisitOMPSeqCstClause(OMPSeqCstClause *) {}
 
+void OMPClauseReader::VisitOMPAcqRelClause(OMPAcqRelClause *) {}
+
+void OMPClauseReader::VisitOMPAcquireClause(OMPAcquireClause *) {}
+
+void OMPClauseReader::VisitOMPReleaseClause(OMPReleaseClause *) {}
+
+void OMPClauseReader::VisitOMPRelaxedClause(OMPRelaxedClause *) {}
+
 void OMPClauseReader::VisitOMPThreadsClause(OMPThreadsClause *) {}
 
 void OMPClauseReader::VisitOMPSIMDClause(OMPSIMDClause *) {}
 
 void OMPClauseReader::VisitOMPNogroupClause(OMPNogroupClause *) {}
 
+void OMPClauseReader::VisitOMPDestroyClause(OMPDestroyClause *) {}
+
 void OMPClauseReader::VisitOMPUnifiedAddressClause(OMPUnifiedAddressClause *) {}
 
 void OMPClauseReader::VisitOMPUnifiedSharedMemoryClause(
@@ -11927,6 +12233,7 @@ void OMPClauseReader::VisitOMPSharedClause(OMPSharedClause *C) {
 void OMPClauseReader::VisitOMPReductionClause(OMPReductionClause *C) {
   VisitOMPClauseWithPostUpdate(C);
   C->setLParenLoc(Record.readSourceLocation());
+  C->setModifierLoc(Record.readSourceLocation());
   C->setColonLoc(Record.readSourceLocation());
   NestedNameSpecifierLoc NNSL = Record.readNestedNameSpecifierLoc();
   DeclarationNameInfo DNI = Record.readDeclarationNameInfo();
@@ -11955,6 +12262,20 @@ void OMPClauseReader::VisitOMPReductionClause(OMPReductionClause *C) {
   for (unsigned i = 0; i != NumVars; ++i)
     Vars.push_back(Record.readSubExpr());
   C->setReductionOps(Vars);
+  if (C->getModifier() == OMPC_REDUCTION_inscan) {
+    Vars.clear();
+    for (unsigned i = 0; i != NumVars; ++i)
+      Vars.push_back(Record.readSubExpr());
+    C->setInscanCopyOps(Vars);
+    Vars.clear();
+    for (unsigned i = 0; i != NumVars; ++i)
+      Vars.push_back(Record.readSubExpr());
+    C->setInscanCopyArrayTemps(Vars);
+    Vars.clear();
+    for (unsigned i = 0; i != NumVars; ++i)
+      Vars.push_back(Record.readSubExpr());
+    C->setInscanCopyArrayElems(Vars);
+  }
 }
 
 void OMPClauseReader::VisitOMPTaskReductionClause(OMPTaskReductionClause *C) {
@@ -12129,8 +12450,14 @@ void OMPClauseReader::VisitOMPFlushClause(OMPFlushClause *C) {
   C->setVarRefs(Vars);
 }
 
+void OMPClauseReader::VisitOMPDepobjClause(OMPDepobjClause *C) {
+  C->setDepobj(Record.readSubExpr());
+  C->setLParenLoc(Record.readSourceLocation());
+}
+
 void OMPClauseReader::VisitOMPDependClause(OMPDependClause *C) {
   C->setLParenLoc(Record.readSourceLocation());
+  C->setModifier(Record.readSubExpr());
   C->setDependencyKind(
       static_cast<OpenMPDependClauseKind>(Record.readInt()));
   C->setDependencyLoc(Record.readSourceLocation());
@@ -12147,13 +12474,15 @@ void OMPClauseReader::VisitOMPDependClause(OMPDependClause *C) {
 
 void OMPClauseReader::VisitOMPDeviceClause(OMPDeviceClause *C) {
   VisitOMPClauseWithPreInit(C);
+  C->setModifier(Record.readEnum<OpenMPDeviceClauseModifier>());
   C->setDevice(Record.readSubExpr());
+  C->setModifierLoc(Record.readSourceLocation());
   C->setLParenLoc(Record.readSourceLocation());
 }
 
 void OMPClauseReader::VisitOMPMapClause(OMPMapClause *C) {
   C->setLParenLoc(Record.readSourceLocation());
-  for (unsigned I = 0; I < OMPMapClause::NumberOfModifiers; ++I) {
+  for (unsigned I = 0; I < NumberOfOMPMapClauseModifiers; ++I) {
     C->setMapTypeModifier(
         I, static_cast<OpenMPMapModifierKind>(Record.readInt()));
     C->setMapTypeModifierLoc(I, Record.readSourceLocation());
@@ -12427,6 +12756,48 @@ void OMPClauseReader::VisitOMPUseDevicePtrClause(OMPUseDevicePtrClause *C) {
   C->setComponents(Components, ListSizes);
 }
 
+void OMPClauseReader::VisitOMPUseDeviceAddrClause(OMPUseDeviceAddrClause *C) {
+  C->setLParenLoc(Record.readSourceLocation());
+  auto NumVars = C->varlist_size();
+  auto UniqueDecls = C->getUniqueDeclarationsNum();
+  auto TotalLists = C->getTotalComponentListNum();
+  auto TotalComponents = C->getTotalComponentsNum();
+
+  SmallVector<Expr *, 16> Vars;
+  Vars.reserve(NumVars);
+  for (unsigned i = 0; i != NumVars; ++i)
+    Vars.push_back(Record.readSubExpr());
+  C->setVarRefs(Vars);
+
+  SmallVector<ValueDecl *, 16> Decls;
+  Decls.reserve(UniqueDecls);
+  for (unsigned i = 0; i < UniqueDecls; ++i)
+    Decls.push_back(Record.readDeclAs<ValueDecl>());
+  C->setUniqueDecls(Decls);
+
+  SmallVector<unsigned, 16> ListsPerDecl;
+  ListsPerDecl.reserve(UniqueDecls);
+  for (unsigned i = 0; i < UniqueDecls; ++i)
+    ListsPerDecl.push_back(Record.readInt());
+  C->setDeclNumLists(ListsPerDecl);
+
+  SmallVector<unsigned, 32> ListSizes;
+  ListSizes.reserve(TotalLists);
+  for (unsigned i = 0; i < TotalLists; ++i)
+    ListSizes.push_back(Record.readInt());
+  C->setComponentListSizes(ListSizes);
+
+  SmallVector<OMPClauseMappableExprCommon::MappableComponent, 32> Components;
+  Components.reserve(TotalComponents);
+  for (unsigned i = 0; i < TotalComponents; ++i) {
+    Expr *AssociatedExpr = Record.readSubExpr();
+    auto *AssociatedDecl = Record.readDeclAs<ValueDecl>();
+    Components.push_back(OMPClauseMappableExprCommon::MappableComponent(
+        AssociatedExpr, AssociatedDecl));
+  }
+  C->setComponents(Components, ListSizes);
+}
+
 void OMPClauseReader::VisitOMPIsDevicePtrClause(OMPIsDevicePtrClause *C) {
   C->setLParenLoc(Record.readSourceLocation());
   auto NumVars = C->varlist_size();
@@ -12484,3 +12855,75 @@ void OMPClauseReader::VisitOMPNontemporalClause(OMPNontemporalClause *C) {
     Vars.push_back(Record.readSubExpr());
   C->setPrivateRefs(Vars);
 }
+
+void OMPClauseReader::VisitOMPInclusiveClause(OMPInclusiveClause *C) {
+  C->setLParenLoc(Record.readSourceLocation());
+  unsigned NumVars = C->varlist_size();
+  SmallVector<Expr *, 16> Vars;
+  Vars.reserve(NumVars);
+  for (unsigned i = 0; i != NumVars; ++i)
+    Vars.push_back(Record.readSubExpr());
+  C->setVarRefs(Vars);
+}
+
+void OMPClauseReader::VisitOMPExclusiveClause(OMPExclusiveClause *C) {
+  C->setLParenLoc(Record.readSourceLocation());
+  unsigned NumVars = C->varlist_size();
+  SmallVector<Expr *, 16> Vars;
+  Vars.reserve(NumVars);
+  for (unsigned i = 0; i != NumVars; ++i)
+    Vars.push_back(Record.readSubExpr());
+  C->setVarRefs(Vars);
+}
+
+void OMPClauseReader::VisitOMPUsesAllocatorsClause(OMPUsesAllocatorsClause *C) {
+  C->setLParenLoc(Record.readSourceLocation());
+  unsigned NumOfAllocators = C->getNumberOfAllocators();
+  SmallVector<OMPUsesAllocatorsClause::Data, 4> Data;
+  Data.reserve(NumOfAllocators);
+  for (unsigned I = 0; I != NumOfAllocators; ++I) {
+    OMPUsesAllocatorsClause::Data &D = Data.emplace_back();
+    D.Allocator = Record.readSubExpr();
+    D.AllocatorTraits = Record.readSubExpr();
+    D.LParenLoc = Record.readSourceLocation();
+    D.RParenLoc = Record.readSourceLocation();
+  }
+  C->setAllocatorsData(Data);
+}
+
+void OMPClauseReader::VisitOMPAffinityClause(OMPAffinityClause *C) {
+  C->setLParenLoc(Record.readSourceLocation());
+  C->setModifier(Record.readSubExpr());
+  C->setColonLoc(Record.readSourceLocation());
+  unsigned NumOfLocators = C->varlist_size();
+  SmallVector<Expr *, 4> Locators;
+  Locators.reserve(NumOfLocators);
+  for (unsigned I = 0; I != NumOfLocators; ++I)
+    Locators.push_back(Record.readSubExpr());
+  C->setVarRefs(Locators);
+}
+
+void OMPClauseReader::VisitOMPOrderClause(OMPOrderClause *C) {
+  C->setKind(Record.readEnum<OpenMPOrderClauseKind>());
+  C->setLParenLoc(Record.readSourceLocation());
+  C->setKindKwLoc(Record.readSourceLocation());
+}
+
+OMPTraitInfo *ASTRecordReader::readOMPTraitInfo() {
+  OMPTraitInfo &TI = getContext().getNewOMPTraitInfo();
+  TI.Sets.resize(readUInt32());
+  for (auto &Set : TI.Sets) {
+    Set.Kind = readEnum<llvm::omp::TraitSet>();
+    Set.Selectors.resize(readUInt32());
+    for (auto &Selector : Set.Selectors) {
+      Selector.Kind = readEnum<llvm::omp::TraitSelector>();
+      Selector.ScoreOrCondition = nullptr;
+      if (readBool())
+        Selector.ScoreOrCondition = readExprRef();
+      Selector.Properties.resize(readUInt32());
+      for (auto &Property : Selector.Properties)
+        Property.Kind = readEnum<llvm::omp::TraitProperty>();
+    }
+  }
+  return &TI;
+}
diff --git a/clang/lib/Serialization/ASTReaderDecl.cpp b/clang/lib/Serialization/ASTReaderDecl.cpp
index 96a7d5ae0a31..eef4ab16ec15 100644
--- a/clang/lib/Serialization/ASTReaderDecl.cpp
+++ b/clang/lib/Serialization/ASTReaderDecl.cpp
@@ -365,6 +365,7 @@ namespace clang {
     void VisitCXXConversionDecl(CXXConversionDecl *D);
     void VisitFieldDecl(FieldDecl *FD);
     void VisitMSPropertyDecl(MSPropertyDecl *FD);
+    void VisitMSGuidDecl(MSGuidDecl *D);
     void VisitIndirectFieldDecl(IndirectFieldDecl *FD);
     RedeclarableResult VisitVarDeclImpl(VarDecl *D);
     void VisitVarDecl(VarDecl *VD) { VisitVarDeclImpl(VD); }
@@ -375,6 +376,7 @@ namespace clang {
     void VisitNonTypeTemplateParmDecl(NonTypeTemplateParmDecl *D);
     DeclID VisitTemplateDecl(TemplateDecl *D);
     void VisitConceptDecl(ConceptDecl *D);
+    void VisitRequiresExprBodyDecl(RequiresExprBodyDecl *D);
     RedeclarableResult VisitRedeclarableTemplateDecl(RedeclarableTemplateDecl *D);
     void VisitClassTemplateDecl(ClassTemplateDecl *D);
     void VisitBuiltinTemplateDecl(BuiltinTemplateDecl *D);
@@ -554,7 +556,7 @@ void ASTDeclReader::Visit(Decl *D) {
 
 void ASTDeclReader::VisitDecl(Decl *D) {
   if (D->isTemplateParameter() || D->isTemplateParameterPack() ||
-      isa<ParmVarDecl>(D)) {
+      isa<ParmVarDecl>(D) || isa<ObjCTypeParamDecl>(D)) {
     // We don't want to deserialize the DeclContext of a template
     // parameter or of a parameter of a function template immediately.   These
     // entities might be used in the formulation of its DeclContext (for
@@ -1282,10 +1284,9 @@ void ASTDeclReader::VisitObjCPropertyDecl(ObjCPropertyDecl *D) {
   QualType T = Record.readType();
   TypeSourceInfo *TSI = readTypeSourceInfo();
   D->setType(T, TSI);
-  D->setPropertyAttributes(
-      (ObjCPropertyDecl::PropertyAttributeKind)Record.readInt());
+  D->setPropertyAttributes((ObjCPropertyAttribute::Kind)Record.readInt());
   D->setPropertyAttributesAsWritten(
-      (ObjCPropertyDecl::PropertyAttributeKind)Record.readInt());
+      (ObjCPropertyAttribute::Kind)Record.readInt());
   D->setPropertyImplementation(
       (ObjCPropertyDecl::PropertyControl)Record.readInt());
   DeclarationName GetterName = Record.readDeclarationName();
@@ -1361,6 +1362,19 @@ void ASTDeclReader::VisitMSPropertyDecl(MSPropertyDecl *PD) {
   PD->SetterId = Record.readIdentifier();
 }
 
+void ASTDeclReader::VisitMSGuidDecl(MSGuidDecl *D) {
+  VisitValueDecl(D);
+  D->PartVal.Part1 = Record.readInt();
+  D->PartVal.Part2 = Record.readInt();
+  D->PartVal.Part3 = Record.readInt();
+  for (auto &C : D->PartVal.Part4And5)
+    C = Record.readInt();
+
+  // Add this GUID to the AST context's lookup structure, and merge if needed.
+  if (MSGuidDecl *Existing = Reader.getContext().MSGuidDecls.GetOrInsertNode(D))
+    Reader.getContext().setPrimaryMergedDecl(D, Existing->getCanonicalDecl());
+}
+
 void ASTDeclReader::VisitIndirectFieldDecl(IndirectFieldDecl *FD) {
   VisitValueDecl(FD);
 
@@ -1979,8 +1993,8 @@ void ASTDeclReader::VisitCXXConversionDecl(CXXConversionDecl *D) {
 
 void ASTDeclReader::VisitImportDecl(ImportDecl *D) {
   VisitDecl(D);
-  D->ImportedAndComplete.setPointer(readModule());
-  D->ImportedAndComplete.setInt(Record.readInt());
+  D->ImportedModule = readModule();
+  D->setImportComplete(Record.readInt());
   auto *StoredLocs = D->getTrailingObjects<SourceLocation>();
   for (unsigned I = 0, N = Record.back(); I != N; ++I)
     StoredLocs[I] = readSourceLocation();
@@ -2037,6 +2051,9 @@ void ASTDeclReader::VisitConceptDecl(ConceptDecl *D) {
   mergeMergeable(D);
 }
 
+void ASTDeclReader::VisitRequiresExprBodyDecl(RequiresExprBodyDecl *D) {
+}
+
 ASTDeclReader::RedeclarableResult
 ASTDeclReader::VisitRedeclarableTemplateDecl(RedeclarableTemplateDecl *D) {
   RedeclarableResult Redecl = VisitRedeclarable(D);
@@ -2313,12 +2330,12 @@ void ASTDeclReader::VisitTemplateTypeParmDecl(TemplateTypeParmDecl *D) {
 
   D->setDeclaredWithTypename(Record.readInt());
 
-  if (Record.readInt()) {
+  if (Record.readBool()) {
     NestedNameSpecifierLoc NNS = Record.readNestedNameSpecifierLoc();
     DeclarationNameInfo DN = Record.readDeclarationNameInfo();
-    ConceptDecl *NamedConcept = cast<ConceptDecl>(Record.readDecl());
+    ConceptDecl *NamedConcept = Record.readDeclAs<ConceptDecl>();
     const ASTTemplateArgumentListInfo *ArgsAsWritten = nullptr;
-    if (Record.readInt())
+    if (Record.readBool())
         ArgsAsWritten = Record.readASTTemplateArgumentListInfo();
     Expr *ImmediatelyDeclaredConstraint = Record.readExpr();
     D->setTypeConstraint(NNS, DN, /*FoundDecl=*/nullptr, NamedConcept,
@@ -2336,6 +2353,8 @@ void ASTDeclReader::VisitNonTypeTemplateParmDecl(NonTypeTemplateParmDecl *D) {
   // TemplateParmPosition.
   D->setDepth(Record.readInt());
   D->setPosition(Record.readInt());
+  if (D->hasPlaceholderTypeConstraint())
+    D->setPlaceholderTypeConstraint(Record.readExpr());
   if (D->isExpandedParameterPack()) {
     auto TypesAndInfos =
         D->getTrailingObjects<std::pair<QualType, TypeSourceInfo *>>();
@@ -2750,6 +2769,8 @@ public:
     return Reader.readVersionTuple();
   }
 
+  OMPTraitInfo *readOMPTraitInfo() { return Reader.readOMPTraitInfo(); }
+
   template <typename T> T *GetLocalDeclAs(uint32_t LocalID) {
     return Reader.GetLocalDeclAs<T>(LocalID);
   }
@@ -2834,7 +2855,8 @@ static bool isConsumerInterestedIn(ASTContext &Ctx, Decl *D, bool HasBody) {
       isa<PragmaDetectMismatchDecl>(D))
     return true;
   if (isa<OMPThreadPrivateDecl>(D) || isa<OMPDeclareReductionDecl>(D) ||
-      isa<OMPDeclareMapperDecl>(D) || isa<OMPAllocateDecl>(D))
+      isa<OMPDeclareMapperDecl>(D) || isa<OMPAllocateDecl>(D) ||
+      isa<OMPRequiresDecl>(D))
     return !D->getDeclContext()->isFunctionOrMethod();
   if (const auto *Var = dyn_cast<VarDecl>(D))
     return Var->isFileVarDecl() &&
@@ -2859,7 +2881,7 @@ ASTReader::DeclCursorForID(DeclID ID, SourceLocation &Loc) {
   const DeclOffset &DOffs =
       M->DeclOffsets[ID - M->BaseDeclID - NUM_PREDEF_DECL_IDS];
   Loc = TranslateSourceLocation(*M, DOffs.getLocation());
-  return RecordLocation(M, DOffs.BitOffset);
+  return RecordLocation(M, DOffs.getBitOffset(M->DeclsBlockStartOffset));
 }
 
 ASTReader::RecordLocation ASTReader::getLocalBitOffset(uint64_t GlobalOffset) {
@@ -2869,11 +2891,12 @@ ASTReader::RecordLocation ASTReader::getLocalBitOffset(uint64_t GlobalOffset) {
   return RecordLocation(I->second, GlobalOffset - I->second->GlobalBitOffset);
 }
 
-uint64_t ASTReader::getGlobalBitOffset(ModuleFile &M, uint32_t LocalOffset) {
+uint64_t ASTReader::getGlobalBitOffset(ModuleFile &M, uint64_t LocalOffset) {
   return LocalOffset + M.GlobalBitOffset;
 }
 
-static bool isSameTemplateParameterList(const TemplateParameterList *X,
+static bool isSameTemplateParameterList(const ASTContext &C,
+                                        const TemplateParameterList *X,
                                         const TemplateParameterList *Y);
 
 /// Determine whether two template parameters are similar enough
@@ -2885,7 +2908,32 @@ static bool isSameTemplateParameter(const NamedDecl *X,
 
   if (const auto *TX = dyn_cast<TemplateTypeParmDecl>(X)) {
     const auto *TY = cast<TemplateTypeParmDecl>(Y);
-    return TX->isParameterPack() == TY->isParameterPack();
+    if (TX->isParameterPack() != TY->isParameterPack())
+      return false;
+    if (TX->hasTypeConstraint() != TY->hasTypeConstraint())
+      return false;
+    if (TX->hasTypeConstraint()) {
+      const TypeConstraint *TXTC = TX->getTypeConstraint();
+      const TypeConstraint *TYTC = TY->getTypeConstraint();
+      if (TXTC->getNamedConcept() != TYTC->getNamedConcept())
+        return false;
+      if (TXTC->hasExplicitTemplateArgs() != TYTC->hasExplicitTemplateArgs())
+        return false;
+      if (TXTC->hasExplicitTemplateArgs()) {
+        const auto *TXTCArgs = TXTC->getTemplateArgsAsWritten();
+        const auto *TYTCArgs = TYTC->getTemplateArgsAsWritten();
+        if (TXTCArgs->NumTemplateArgs != TYTCArgs->NumTemplateArgs)
+          return false;
+        llvm::FoldingSetNodeID XID, YID;
+        for (const auto &ArgLoc : TXTCArgs->arguments())
+          ArgLoc.getArgument().Profile(XID, X->getASTContext());
+        for (const auto &ArgLoc : TYTCArgs->arguments())
+          ArgLoc.getArgument().Profile(YID, Y->getASTContext());
+        if (XID != YID)
+          return false;
+      }
+    }
+    return true;
   }
 
   if (const auto *TX = dyn_cast<NonTypeTemplateParmDecl>(X)) {
@@ -2897,7 +2945,8 @@ static bool isSameTemplateParameter(const NamedDecl *X,
   const auto *TX = cast<TemplateTemplateParmDecl>(X);
   const auto *TY = cast<TemplateTemplateParmDecl>(Y);
   return TX->isParameterPack() == TY->isParameterPack() &&
-         isSameTemplateParameterList(TX->getTemplateParameters(),
+         isSameTemplateParameterList(TX->getASTContext(),
+                                     TX->getTemplateParameters(),
                                      TY->getTemplateParameters());
 }
 
@@ -2950,7 +2999,8 @@ static bool isSameQualifier(const NestedNameSpecifier *X,
 
 /// Determine whether two template parameter lists are similar enough
 /// that they may be used in declarations of the same template.
-static bool isSameTemplateParameterList(const TemplateParameterList *X,
+static bool isSameTemplateParameterList(const ASTContext &C,
+                                        const TemplateParameterList *X,
                                         const TemplateParameterList *Y) {
   if (X->size() != Y->size())
     return false;
@@ -2959,6 +3009,18 @@ static bool isSameTemplateParameterList(const TemplateParameterList *X,
     if (!isSameTemplateParameter(X->getParam(I), Y->getParam(I)))
       return false;
 
+  const Expr *XRC = X->getRequiresClause();
+  const Expr *YRC = Y->getRequiresClause();
+  if (!XRC != !YRC)
+    return false;
+  if (XRC) {
+    llvm::FoldingSetNodeID XRCID, YRCID;
+    XRC->Profile(XRCID, C, /*Canonical=*/true);
+    YRC->Profile(YRCID, C, /*Canonical=*/true);
+    if (XRCID != YRCID)
+      return false;
+  }
+
   return true;
 }
 
@@ -2995,7 +3057,7 @@ static bool hasSameOverloadableAttrs(const FunctionDecl *A,
   return true;
 }
 
-/// Determine whether the two declarations refer to the same entity.
+/// Determine whether the two declarations refer to the same entity.pr
 static bool isSameEntity(NamedDecl *X, NamedDecl *Y) {
   assert(X->getDeclName() == Y->getDeclName() && "Declaration name mismatch!");
 
@@ -3070,6 +3132,19 @@ static bool isSameEntity(NamedDecl *X, NamedDecl *Y) {
     }
 
     ASTContext &C = FuncX->getASTContext();
+
+    const Expr *XRC = FuncX->getTrailingRequiresClause();
+    const Expr *YRC = FuncY->getTrailingRequiresClause();
+    if (!XRC != !YRC)
+      return false;
+    if (XRC) {
+      llvm::FoldingSetNodeID XRCID, YRCID;
+      XRC->Profile(XRCID, C, /*Canonical=*/true);
+      YRC->Profile(YRCID, C, /*Canonical=*/true);
+      if (XRCID != YRCID)
+        return false;
+    }
+
     auto GetTypeAsWritten = [](const FunctionDecl *FD) {
       // Map to the first declaration that we've already merged into this one.
       // The TSI of redeclarations might not match (due to calling conventions
@@ -3093,6 +3168,7 @@ static bool isSameEntity(NamedDecl *X, NamedDecl *Y) {
         return true;
       return false;
     }
+
     return FuncX->getLinkageInternal() == FuncY->getLinkageInternal() &&
            hasSameOverloadableAttrs(FuncX, FuncY);
   }
@@ -3132,7 +3208,8 @@ static bool isSameEntity(NamedDecl *X, NamedDecl *Y) {
     const auto *TemplateY = cast<TemplateDecl>(Y);
     return isSameEntity(TemplateX->getTemplatedDecl(),
                         TemplateY->getTemplatedDecl()) &&
-           isSameTemplateParameterList(TemplateX->getTemplateParameters(),
+           isSameTemplateParameterList(TemplateX->getASTContext(),
+                                       TemplateX->getTemplateParameters(),
                                        TemplateY->getTemplateParameters());
   }
 
@@ -3819,13 +3896,19 @@ Decl *ASTReader::ReadDeclRecord(DeclID ID) {
                                                  HasTypeConstraint);
     break;
   }
-  case DECL_NON_TYPE_TEMPLATE_PARM:
-    D = NonTypeTemplateParmDecl::CreateDeserialized(Context, ID);
+  case DECL_NON_TYPE_TEMPLATE_PARM: {
+    bool HasTypeConstraint = Record.readInt();
+    D = NonTypeTemplateParmDecl::CreateDeserialized(Context, ID,
+                                                    HasTypeConstraint);
     break;
-  case DECL_EXPANDED_NON_TYPE_TEMPLATE_PARM_PACK:
+  }
+  case DECL_EXPANDED_NON_TYPE_TEMPLATE_PARM_PACK: {
+    bool HasTypeConstraint = Record.readInt();
     D = NonTypeTemplateParmDecl::CreateDeserialized(Context, ID,
-                                                    Record.readInt());
+                                                    Record.readInt(),
+                                                    HasTypeConstraint);
     break;
+  }
   case DECL_TEMPLATE_TEMPLATE_PARM:
     D = TemplateTemplateParmDecl::CreateDeserialized(Context, ID);
     break;
@@ -3839,6 +3922,9 @@ Decl *ASTReader::ReadDeclRecord(DeclID ID) {
   case DECL_CONCEPT:
     D = ConceptDecl::CreateDeserialized(Context, ID);
     break;
+  case DECL_REQUIRES_EXPR_BODY:
+    D = RequiresExprBodyDecl::CreateDeserialized(Context, ID);
+    break;
   case DECL_STATIC_ASSERT:
     D = StaticAssertDecl::CreateDeserialized(Context, ID);
     break;
@@ -3905,6 +3991,9 @@ Decl *ASTReader::ReadDeclRecord(DeclID ID) {
   case DECL_MS_PROPERTY:
     D = MSPropertyDecl::CreateDeserialized(Context, ID);
     break;
+  case DECL_MS_GUID:
+    D = MSGuidDecl::CreateDeserialized(Context, ID);
+    break;
   case DECL_CAPTURED:
     D = CapturedDecl::CreateDeserialized(Context, ID, Record.readInt());
     break;
diff --git a/clang/lib/Serialization/ASTReaderStmt.cpp b/clang/lib/Serialization/ASTReaderStmt.cpp
index f558c26b5f1e..a40c5499a6d7 100644
--- a/clang/lib/Serialization/ASTReaderStmt.cpp
+++ b/clang/lib/Serialization/ASTReaderStmt.cpp
@@ -11,7 +11,6 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "clang/Serialization/ASTRecordReader.h"
 #include "clang/AST/ASTConcept.h"
 #include "clang/AST/ASTContext.h"
 #include "clang/AST/AttrIterator.h"
@@ -22,6 +21,7 @@
 #include "clang/AST/DeclObjC.h"
 #include "clang/AST/DeclTemplate.h"
 #include "clang/AST/DeclarationName.h"
+#include "clang/AST/DependenceFlags.h"
 #include "clang/AST/Expr.h"
 #include "clang/AST/ExprCXX.h"
 #include "clang/AST/ExprObjC.h"
@@ -49,6 +49,8 @@
 #include "clang/Basic/TypeTraits.h"
 #include "clang/Lex/Token.h"
 #include "clang/Serialization/ASTBitCodes.h"
+#include "clang/Serialization/ASTRecordReader.h"
+#include "llvm/ADT/BitmaskEnum.h"
 #include "llvm/ADT/DenseMap.h"
 #include "llvm/ADT/SmallString.h"
 #include "llvm/ADT/SmallVector.h"
@@ -101,11 +103,12 @@ namespace clang {
 
     /// The number of record fields required for the Stmt class
     /// itself.
-    static const unsigned NumStmtFields = 1;
+    static const unsigned NumStmtFields = 0;
 
     /// The number of record fields required for the Expr class
     /// itself.
-    static const unsigned NumExprFields = NumStmtFields + 7;
+    static const unsigned NumExprFields =
+        NumStmtFields + llvm::BitWidth<ExprDependence> + 3;
 
     /// Read and initialize a ExplicitTemplateArgumentList structure.
     void ReadTemplateKWAndArgsInfo(ASTTemplateKWAndArgsInfo &Args,
@@ -137,7 +140,6 @@ void ASTStmtReader::ReadTemplateKWAndArgsInfo(ASTTemplateKWAndArgsInfo &Args,
 }
 
 void ASTStmtReader::VisitStmt(Stmt *S) {
-  S->setIsOMPStructuredBlock(Record.readInt());
   assert(Record.getIdx() == NumStmtFields && "Incorrect statement field count");
 }
 
@@ -269,6 +271,8 @@ void ASTStmtReader::VisitWhileStmt(WhileStmt *S) {
     S->setConditionVariable(Record.getContext(), readDeclAs<VarDecl>());
 
   S->setWhileLoc(readSourceLocation());
+  S->setLParenLoc(readSourceLocation());
+  S->setRParenLoc(readSourceLocation());
 }
 
 void ASTStmtReader::VisitDoStmt(DoStmt *S) {
@@ -511,10 +515,26 @@ void ASTStmtReader::VisitCapturedStmt(CapturedStmt *S) {
 void ASTStmtReader::VisitExpr(Expr *E) {
   VisitStmt(E);
   E->setType(Record.readType());
-  E->setTypeDependent(Record.readInt());
-  E->setValueDependent(Record.readInt());
-  E->setInstantiationDependent(Record.readInt());
-  E->ExprBits.ContainsUnexpandedParameterPack = Record.readInt();
+
+  // FIXME: write and read all DependentFlags with a single call.
+  bool TypeDependent = Record.readInt();
+  bool ValueDependent = Record.readInt();
+  bool InstantiationDependent = Record.readInt();
+  bool ContainsUnexpandedTemplateParameters = Record.readInt();
+  bool ContainsErrors = Record.readInt();
+  auto Deps = ExprDependence::None;
+  if (TypeDependent)
+    Deps |= ExprDependence::Type;
+  if (ValueDependent)
+    Deps |= ExprDependence::Value;
+  if (InstantiationDependent)
+    Deps |= ExprDependence::Instantiation;
+  if (ContainsUnexpandedTemplateParameters)
+    Deps |= ExprDependence::UnexpandedPack;
+  if (ContainsErrors)
+    Deps |= ExprDependence::Error;
+  E->setDependence(Deps);
+
   E->setValueKind(static_cast<ExprValueKind>(Record.readInt()));
   E->setObjectKind(static_cast<ExprObjectKind>(Record.readInt()));
   assert(Record.getIdx() == NumExprFields &&
@@ -523,18 +543,35 @@ void ASTStmtReader::VisitExpr(Expr *E) {
 
 void ASTStmtReader::VisitConstantExpr(ConstantExpr *E) {
   VisitExpr(E);
-  E->ConstantExprBits.ResultKind = Record.readInt();
-  switch (E->ConstantExprBits.ResultKind) {
-  case ConstantExpr::RSK_Int64: {
+
+  auto StorageKind = Record.readInt();
+  assert(E->ConstantExprBits.ResultKind == StorageKind && "Wrong ResultKind!");
+
+  E->ConstantExprBits.APValueKind = Record.readInt();
+  E->ConstantExprBits.IsUnsigned = Record.readInt();
+  E->ConstantExprBits.BitWidth = Record.readInt();
+  E->ConstantExprBits.HasCleanup = false; // Not serialized, see below.
+  E->ConstantExprBits.IsImmediateInvocation = Record.readInt();
+
+  switch (StorageKind) {
+  case ConstantExpr::RSK_None:
+    break;
+
+  case ConstantExpr::RSK_Int64:
     E->Int64Result() = Record.readInt();
-    uint64_t tmp = Record.readInt();
-    E->ConstantExprBits.IsUnsigned = tmp & 0x1;
-    E->ConstantExprBits.BitWidth = tmp >> 1;
     break;
-  }
+
   case ConstantExpr::RSK_APValue:
     E->APValueResult() = Record.readAPValue();
+    if (E->APValueResult().needsCleanup()) {
+      E->ConstantExprBits.HasCleanup = true;
+      Record.getContext().addDestruction(&E->APValueResult());
+    }
+    break;
+  default:
+    llvm_unreachable("unexpected ResultKind!");
   }
+
   E->setSubExpr(Record.readSubExpr());
 }
 
@@ -587,6 +624,7 @@ void ASTStmtReader::VisitIntegerLiteral(IntegerLiteral *E) {
 void ASTStmtReader::VisitFixedPointLiteral(FixedPointLiteral *E) {
   VisitExpr(E);
   E->setLocation(readSourceLocation());
+  E->setScale(Record.readInt());
   E->setValue(Record.getContext(), Record.readAPInt());
 }
 
@@ -663,10 +701,14 @@ void ASTStmtReader::VisitParenListExpr(ParenListExpr *E) {
 
 void ASTStmtReader::VisitUnaryOperator(UnaryOperator *E) {
   VisitExpr(E);
+  bool hasFP_Features = Record.readInt();
+  assert(hasFP_Features == E->hasStoredFPFeatures());
   E->setSubExpr(Record.readSubExpr());
   E->setOpcode((UnaryOperator::Opcode)Record.readInt());
   E->setOperatorLoc(readSourceLocation());
   E->setCanOverflow(Record.readInt());
+  if (hasFP_Features)
+    E->setStoredFPFeatures(FPOptionsOverride(Record.readInt()));
 }
 
 void ASTStmtReader::VisitOffsetOfExpr(OffsetOfExpr *E) {
@@ -724,27 +766,15 @@ void ASTStmtReader::VisitUnaryExprOrTypeTraitExpr(UnaryExprOrTypeTraitExpr *E) {
   E->setRParenLoc(readSourceLocation());
 }
 
-void ASTStmtReader::VisitConceptSpecializationExpr(
-        ConceptSpecializationExpr *E) {
-  VisitExpr(E);
-  unsigned NumTemplateArgs = Record.readInt();
-  E->NestedNameSpec = Record.readNestedNameSpecifierLoc();
-  E->TemplateKWLoc = Record.readSourceLocation();
-  E->ConceptName = Record.readDeclarationNameInfo();
-  E->NamedConcept = readDeclAs<ConceptDecl>();
-  E->ArgsAsWritten = Record.readASTTemplateArgumentListInfo();
-  llvm::SmallVector<TemplateArgument, 4> Args;
-  for (unsigned I = 0; I < NumTemplateArgs; ++I)
-    Args.push_back(Record.readTemplateArgument());
-  E->setTemplateArguments(Args);
+static ConstraintSatisfaction
+readConstraintSatisfaction(ASTRecordReader &Record) {
   ConstraintSatisfaction Satisfaction;
   Satisfaction.IsSatisfied = Record.readInt();
   if (!Satisfaction.IsSatisfied) {
     unsigned NumDetailRecords = Record.readInt();
     for (unsigned i = 0; i != NumDetailRecords; ++i) {
       Expr *ConstraintExpr = Record.readExpr();
-      bool IsDiagnostic = Record.readInt();
-      if (IsDiagnostic) {
+      if (/* IsDiagnostic */Record.readInt()) {
         SourceLocation DiagLocation = Record.readSourceLocation();
         std::string DiagMessage = Record.readString();
         Satisfaction.Details.emplace_back(
@@ -755,8 +785,138 @@ void ASTStmtReader::VisitConceptSpecializationExpr(
         Satisfaction.Details.emplace_back(ConstraintExpr, Record.readExpr());
     }
   }
-  E->Satisfaction = ASTConstraintSatisfaction::Create(Record.getContext(),
-                                                      Satisfaction);
+  return Satisfaction;
+}
+
+void ASTStmtReader::VisitConceptSpecializationExpr(
+        ConceptSpecializationExpr *E) {
+  VisitExpr(E);
+  unsigned NumTemplateArgs = Record.readInt();
+  E->NestedNameSpec = Record.readNestedNameSpecifierLoc();
+  E->TemplateKWLoc = Record.readSourceLocation();
+  E->ConceptName = Record.readDeclarationNameInfo();
+  E->NamedConcept = readDeclAs<ConceptDecl>();
+  E->FoundDecl = Record.readDeclAs<NamedDecl>();
+  E->ArgsAsWritten = Record.readASTTemplateArgumentListInfo();
+  llvm::SmallVector<TemplateArgument, 4> Args;
+  for (unsigned I = 0; I < NumTemplateArgs; ++I)
+    Args.push_back(Record.readTemplateArgument());
+  E->setTemplateArguments(Args);
+  E->Satisfaction = E->isValueDependent() ? nullptr :
+      ASTConstraintSatisfaction::Create(Record.getContext(),
+                                        readConstraintSatisfaction(Record));
+}
+
+static concepts::Requirement::SubstitutionDiagnostic *
+readSubstitutionDiagnostic(ASTRecordReader &Record) {
+  std::string SubstitutedEntity = Record.readString();
+  SourceLocation DiagLoc = Record.readSourceLocation();
+  std::string DiagMessage = Record.readString();
+  return new (Record.getContext())
+      concepts::Requirement::SubstitutionDiagnostic{SubstitutedEntity, DiagLoc,
+                                                    DiagMessage};
+}
+
+void ASTStmtReader::VisitRequiresExpr(RequiresExpr *E) {
+  VisitExpr(E);
+  unsigned NumLocalParameters = Record.readInt();
+  unsigned NumRequirements = Record.readInt();
+  E->RequiresExprBits.RequiresKWLoc = Record.readSourceLocation();
+  E->RequiresExprBits.IsSatisfied = Record.readInt();
+  E->Body = Record.readDeclAs<RequiresExprBodyDecl>();
+  llvm::SmallVector<ParmVarDecl *, 4> LocalParameters;
+  for (unsigned i = 0; i < NumLocalParameters; ++i)
+    LocalParameters.push_back(cast<ParmVarDecl>(Record.readDecl()));
+  std::copy(LocalParameters.begin(), LocalParameters.end(),
+            E->getTrailingObjects<ParmVarDecl *>());
+  llvm::SmallVector<concepts::Requirement *, 4> Requirements;
+  for (unsigned i = 0; i < NumRequirements; ++i) {
+    auto RK =
+        static_cast<concepts::Requirement::RequirementKind>(Record.readInt());
+    concepts::Requirement *R = nullptr;
+    switch (RK) {
+      case concepts::Requirement::RK_Type: {
+        auto Status =
+            static_cast<concepts::TypeRequirement::SatisfactionStatus>(
+                Record.readInt());
+        if (Status == concepts::TypeRequirement::SS_SubstitutionFailure)
+          R = new (Record.getContext())
+              concepts::TypeRequirement(readSubstitutionDiagnostic(Record));
+        else
+          R = new (Record.getContext())
+              concepts::TypeRequirement(Record.readTypeSourceInfo());
+      } break;
+      case concepts::Requirement::RK_Simple:
+      case concepts::Requirement::RK_Compound: {
+        auto Status =
+            static_cast<concepts::ExprRequirement::SatisfactionStatus>(
+                Record.readInt());
+        llvm::PointerUnion<concepts::Requirement::SubstitutionDiagnostic *,
+                           Expr *> E;
+        if (Status == concepts::ExprRequirement::SS_ExprSubstitutionFailure) {
+          E = readSubstitutionDiagnostic(Record);
+        } else
+          E = Record.readExpr();
+
+        llvm::Optional<concepts::ExprRequirement::ReturnTypeRequirement> Req;
+        ConceptSpecializationExpr *SubstitutedConstraintExpr = nullptr;
+        SourceLocation NoexceptLoc;
+        if (RK == concepts::Requirement::RK_Simple) {
+          Req.emplace();
+        } else {
+          NoexceptLoc = Record.readSourceLocation();
+          switch (/* returnTypeRequirementKind */Record.readInt()) {
+            case 0:
+              // No return type requirement.
+              Req.emplace();
+              break;
+            case 1: {
+              // type-constraint
+              TemplateParameterList *TPL = Record.readTemplateParameterList();
+              if (Status >=
+                  concepts::ExprRequirement::SS_ConstraintsNotSatisfied)
+                SubstitutedConstraintExpr =
+                    cast<ConceptSpecializationExpr>(Record.readExpr());
+              Req.emplace(TPL);
+            } break;
+            case 2:
+              // Substitution failure
+              Req.emplace(readSubstitutionDiagnostic(Record));
+              break;
+          }
+        }
+        if (Expr *Ex = E.dyn_cast<Expr *>())
+          R = new (Record.getContext()) concepts::ExprRequirement(
+                  Ex, RK == concepts::Requirement::RK_Simple, NoexceptLoc,
+                  std::move(*Req), Status, SubstitutedConstraintExpr);
+        else
+          R = new (Record.getContext()) concepts::ExprRequirement(
+                  E.get<concepts::Requirement::SubstitutionDiagnostic *>(),
+                  RK == concepts::Requirement::RK_Simple, NoexceptLoc,
+                  std::move(*Req));
+      } break;
+      case concepts::Requirement::RK_Nested: {
+        if (/* IsSubstitutionDiagnostic */Record.readInt()) {
+          R = new (Record.getContext()) concepts::NestedRequirement(
+              readSubstitutionDiagnostic(Record));
+          break;
+        }
+        Expr *E = Record.readExpr();
+        if (E->isInstantiationDependent())
+          R = new (Record.getContext()) concepts::NestedRequirement(E);
+        else
+          R = new (Record.getContext())
+              concepts::NestedRequirement(Record.getContext(), E,
+                                          readConstraintSatisfaction(Record));
+      } break;
+    }
+    if (!R)
+      continue;
+    Requirements.push_back(R);
+  }
+  std::copy(Requirements.begin(), Requirements.end(),
+            E->getTrailingObjects<concepts::Requirement *>());
+  E->RBraceLoc = Record.readSourceLocation();
 }
 
 void ASTStmtReader::VisitArraySubscriptExpr(ArraySubscriptExpr *E) {
@@ -766,15 +926,68 @@ void ASTStmtReader::VisitArraySubscriptExpr(ArraySubscriptExpr *E) {
   E->setRBracketLoc(readSourceLocation());
 }
 
+void ASTStmtReader::VisitMatrixSubscriptExpr(MatrixSubscriptExpr *E) {
+  VisitExpr(E);
+  E->setBase(Record.readSubExpr());
+  E->setRowIdx(Record.readSubExpr());
+  E->setColumnIdx(Record.readSubExpr());
+  E->setRBracketLoc(readSourceLocation());
+}
+
 void ASTStmtReader::VisitOMPArraySectionExpr(OMPArraySectionExpr *E) {
   VisitExpr(E);
   E->setBase(Record.readSubExpr());
   E->setLowerBound(Record.readSubExpr());
   E->setLength(Record.readSubExpr());
-  E->setColonLoc(readSourceLocation());
+  E->setStride(Record.readSubExpr());
+  E->setColonLocFirst(readSourceLocation());
+  E->setColonLocSecond(readSourceLocation());
   E->setRBracketLoc(readSourceLocation());
 }
 
+void ASTStmtReader::VisitOMPArrayShapingExpr(OMPArrayShapingExpr *E) {
+  VisitExpr(E);
+  unsigned NumDims = Record.readInt();
+  E->setBase(Record.readSubExpr());
+  SmallVector<Expr *, 4> Dims(NumDims);
+  for (unsigned I = 0; I < NumDims; ++I)
+    Dims[I] = Record.readSubExpr();
+  E->setDimensions(Dims);
+  SmallVector<SourceRange, 4> SRs(NumDims);
+  for (unsigned I = 0; I < NumDims; ++I)
+    SRs[I] = readSourceRange();
+  E->setBracketsRanges(SRs);
+  E->setLParenLoc(readSourceLocation());
+  E->setRParenLoc(readSourceLocation());
+}
+
+void ASTStmtReader::VisitOMPIteratorExpr(OMPIteratorExpr *E) {
+  VisitExpr(E);
+  unsigned NumIters = Record.readInt();
+  E->setIteratorKwLoc(readSourceLocation());
+  E->setLParenLoc(readSourceLocation());
+  E->setRParenLoc(readSourceLocation());
+  for (unsigned I = 0; I < NumIters; ++I) {
+    E->setIteratorDeclaration(I, Record.readDeclRef());
+    E->setAssignmentLoc(I, readSourceLocation());
+    Expr *Begin = Record.readSubExpr();
+    Expr *End = Record.readSubExpr();
+    Expr *Step = Record.readSubExpr();
+    SourceLocation ColonLoc = readSourceLocation();
+    SourceLocation SecColonLoc;
+    if (Step)
+      SecColonLoc = readSourceLocation();
+    E->setIteratorRange(I, Begin, ColonLoc, End, SecColonLoc, Step);
+    // Deserialize helpers
+    OMPIteratorHelperData HD;
+    HD.CounterVD = cast_or_null<VarDecl>(Record.readDeclRef());
+    HD.Upper = Record.readSubExpr();
+    HD.Update = Record.readSubExpr();
+    HD.CounterUpdate = Record.readSubExpr();
+    E->setHelper(I, HD);
+  }
+}
+
 void ASTStmtReader::VisitCallExpr(CallExpr *E) {
   VisitExpr(E);
   unsigned NumArgs = Record.readInt();
@@ -871,12 +1084,16 @@ void ASTStmtReader::VisitCastExpr(CastExpr *E) {
 }
 
 void ASTStmtReader::VisitBinaryOperator(BinaryOperator *E) {
+  bool hasFP_Features;
+  BinaryOperator::Opcode opc;
   VisitExpr(E);
+  E->setHasStoredFPFeatures(hasFP_Features = Record.readInt());
+  E->setOpcode(opc = (BinaryOperator::Opcode)Record.readInt());
   E->setLHS(Record.readSubExpr());
   E->setRHS(Record.readSubExpr());
-  E->setOpcode((BinaryOperator::Opcode)Record.readInt());
   E->setOperatorLoc(readSourceLocation());
-  E->setFPFeatures(FPOptions(Record.readInt()));
+  if (hasFP_Features)
+    E->setStoredFPFeatures(FPOptionsOverride(Record.readInt()));
 }
 
 void ASTStmtReader::VisitCompoundAssignOperator(CompoundAssignOperator *E) {
@@ -1073,6 +1290,7 @@ void ASTStmtReader::VisitStmtExpr(StmtExpr *E) {
   E->setLParenLoc(readSourceLocation());
   E->setRParenLoc(readSourceLocation());
   E->setSubStmt(cast_or_null<CompoundStmt>(Record.readSubStmt()));
+  E->StmtExprBits.TemplateDepth = Record.readInt();
 }
 
 void ASTStmtReader::VisitChooseExpr(ChooseExpr *E) {
@@ -1443,8 +1661,8 @@ void ASTStmtReader::VisitMSDependentExistsStmt(MSDependentExistsStmt *S) {
 void ASTStmtReader::VisitCXXOperatorCallExpr(CXXOperatorCallExpr *E) {
   VisitCallExpr(E);
   E->CXXOperatorCallExprBits.OperatorKind = Record.readInt();
-  E->CXXOperatorCallExprBits.FPFeatures = Record.readInt();
   E->Range = Record.readSourceRange();
+  E->setFPFeatures(FPOptionsOverride(Record.readInt()));
 }
 
 void ASTStmtReader::VisitCXXRewrittenBinaryOperator(
@@ -1490,19 +1708,23 @@ void ASTStmtReader::VisitCXXTemporaryObjectExpr(CXXTemporaryObjectExpr *E) {
 void ASTStmtReader::VisitLambdaExpr(LambdaExpr *E) {
   VisitExpr(E);
   unsigned NumCaptures = Record.readInt();
-  assert(NumCaptures == E->NumCaptures);(void)NumCaptures;
+  (void)NumCaptures;
+  assert(NumCaptures == E->LambdaExprBits.NumCaptures);
   E->IntroducerRange = readSourceRange();
-  E->CaptureDefault = static_cast<LambdaCaptureDefault>(Record.readInt());
+  E->LambdaExprBits.CaptureDefault = Record.readInt();
   E->CaptureDefaultLoc = readSourceLocation();
-  E->ExplicitParams = Record.readInt();
-  E->ExplicitResultType = Record.readInt();
+  E->LambdaExprBits.ExplicitParams = Record.readInt();
+  E->LambdaExprBits.ExplicitResultType = Record.readInt();
   E->ClosingBrace = readSourceLocation();
 
   // Read capture initializers.
   for (LambdaExpr::capture_init_iterator C = E->capture_init_begin(),
-                                      CEnd = E->capture_init_end();
+                                         CEnd = E->capture_init_end();
        C != CEnd; ++C)
     *C = Record.readSubExpr();
+
+  // The body will be lazily deserialized when needed from the call operator
+  // declaration.
 }
 
 void
@@ -1532,6 +1754,10 @@ void ASTStmtReader::VisitCXXReinterpretCastExpr(CXXReinterpretCastExpr *E) {
   return VisitCXXNamedCastExpr(E);
 }
 
+void ASTStmtReader::VisitCXXAddrspaceCastExpr(CXXAddrspaceCastExpr *E) {
+  return VisitCXXNamedCastExpr(E);
+}
+
 void ASTStmtReader::VisitCXXConstCastExpr(CXXConstCastExpr *E) {
   return VisitCXXNamedCastExpr(E);
 }
@@ -1567,14 +1793,10 @@ void ASTStmtReader::VisitCXXNullPtrLiteralExpr(CXXNullPtrLiteralExpr *E) {
 void ASTStmtReader::VisitCXXTypeidExpr(CXXTypeidExpr *E) {
   VisitExpr(E);
   E->setSourceRange(readSourceRange());
-  if (E->isTypeOperand()) { // typeid(int)
-    E->setTypeOperandSourceInfo(
-        readTypeSourceInfo());
-    return;
-  }
-
-  // typeid(42+2)
-  E->setExprOperand(Record.readSubExpr());
+  if (E->isTypeOperand())
+    E->Operand = readTypeSourceInfo();
+  else
+    E->Operand = Record.readSubExpr();
 }
 
 void ASTStmtReader::VisitCXXThisExpr(CXXThisExpr *E) {
@@ -1687,9 +1909,17 @@ void ASTStmtReader::VisitExprWithCleanups(ExprWithCleanups *E) {
 
   unsigned NumObjects = Record.readInt();
   assert(NumObjects == E->getNumObjects());
-  for (unsigned i = 0; i != NumObjects; ++i)
-    E->getTrailingObjects<BlockDecl *>()[i] =
-        readDeclAs<BlockDecl>();
+  for (unsigned i = 0; i != NumObjects; ++i) {
+    unsigned CleanupKind = Record.readInt();
+    ExprWithCleanups::CleanupObject Obj;
+    if (CleanupKind == COK_Block)
+      Obj = readDeclAs<BlockDecl>();
+    else if (CleanupKind == COK_CompoundLiteral)
+      Obj = cast<CompoundLiteralExpr>(Record.readSubExpr());
+    else
+      llvm_unreachable("unexpected cleanup object type");
+    E->getTrailingObjects<ExprWithCleanups::CleanupObject>()[i] = Obj;
+  }
 
   E->ExprWithCleanupsBits.CleanupsHaveSideEffects = Record.readInt();
   E->SubExpr = Record.readSubExpr();
@@ -1936,6 +2166,19 @@ void ASTStmtReader::VisitTypoExpr(TypoExpr *E) {
   llvm_unreachable("Cannot read TypoExpr nodes");
 }
 
+void ASTStmtReader::VisitRecoveryExpr(RecoveryExpr *E) {
+  VisitExpr(E);
+  unsigned NumArgs = Record.readInt();
+  E->BeginLoc = readSourceLocation();
+  E->EndLoc = readSourceLocation();
+  assert(
+      (NumArgs == std::distance(E->children().begin(), E->children().end())) &&
+      "Wrong NumArgs!");
+  (void)NumArgs;
+  for (Stmt *&Child : E->children())
+    Child = Record.readSubStmt();
+}
+
 //===----------------------------------------------------------------------===//
 // Microsoft Expressions and Statements
 //===----------------------------------------------------------------------===//
@@ -1958,16 +2201,11 @@ void ASTStmtReader::VisitMSPropertySubscriptExpr(MSPropertySubscriptExpr *E) {
 void ASTStmtReader::VisitCXXUuidofExpr(CXXUuidofExpr *E) {
   VisitExpr(E);
   E->setSourceRange(readSourceRange());
-  std::string UuidStr = readString();
-  E->setUuidStr(StringRef(UuidStr).copy(Record.getContext()));
-  if (E->isTypeOperand()) { // __uuidof(ComType)
-    E->setTypeOperandSourceInfo(
-        readTypeSourceInfo());
-    return;
-  }
-
-  // __uuidof(expr)
-  E->setExprOperand(Record.readSubExpr());
+  E->Guid = readDeclAs<MSGuidDecl>();
+  if (E->isTypeOperand())
+    E->Operand = readTypeSourceInfo();
+  else
+    E->Operand = Record.readSubExpr();
 }
 
 void ASTStmtReader::VisitSEHLeaveStmt(SEHLeaveStmt *S) {
@@ -2111,6 +2349,7 @@ void ASTStmtReader::VisitOMPParallelDirective(OMPParallelDirective *D) {
   // The NumClauses field was read in ReadStmtFromStream.
   Record.skipInts(1);
   VisitOMPExecutableDirective(D);
+  D->setTaskReductionRefExpr(Record.readSubExpr());
   D->setHasCancel(Record.readInt());
 }
 
@@ -2120,6 +2359,7 @@ void ASTStmtReader::VisitOMPSimdDirective(OMPSimdDirective *D) {
 
 void ASTStmtReader::VisitOMPForDirective(OMPForDirective *D) {
   VisitOMPLoopDirective(D);
+  D->setTaskReductionRefExpr(Record.readSubExpr());
   D->setHasCancel(Record.readInt());
 }
 
@@ -2132,6 +2372,7 @@ void ASTStmtReader::VisitOMPSectionsDirective(OMPSectionsDirective *D) {
   // The NumClauses field was read in ReadStmtFromStream.
   Record.skipInts(1);
   VisitOMPExecutableDirective(D);
+  D->setTaskReductionRefExpr(Record.readSubExpr());
   D->setHasCancel(Record.readInt());
 }
 
@@ -2163,6 +2404,7 @@ void ASTStmtReader::VisitOMPCriticalDirective(OMPCriticalDirective *D) {
 
 void ASTStmtReader::VisitOMPParallelForDirective(OMPParallelForDirective *D) {
   VisitOMPLoopDirective(D);
+  D->setTaskReductionRefExpr(Record.readSubExpr());
   D->setHasCancel(Record.readInt());
 }
 
@@ -2177,6 +2419,7 @@ void ASTStmtReader::VisitOMPParallelMasterDirective(
   // The NumClauses field was read in ReadStmtFromStream.
   Record.skipInts(1);
   VisitOMPExecutableDirective(D);
+  D->setTaskReductionRefExpr(Record.readSubExpr());
 }
 
 void ASTStmtReader::VisitOMPParallelSectionsDirective(
@@ -2185,6 +2428,7 @@ void ASTStmtReader::VisitOMPParallelSectionsDirective(
   // The NumClauses field was read in ReadStmtFromStream.
   Record.skipInts(1);
   VisitOMPExecutableDirective(D);
+  D->setTaskReductionRefExpr(Record.readSubExpr());
   D->setHasCancel(Record.readInt());
 }
 
@@ -2226,6 +2470,20 @@ void ASTStmtReader::VisitOMPFlushDirective(OMPFlushDirective *D) {
   VisitOMPExecutableDirective(D);
 }
 
+void ASTStmtReader::VisitOMPDepobjDirective(OMPDepobjDirective *D) {
+  VisitStmt(D);
+  // The NumClauses field was read in ReadStmtFromStream.
+  Record.skipInts(1);
+  VisitOMPExecutableDirective(D);
+}
+
+void ASTStmtReader::VisitOMPScanDirective(OMPScanDirective *D) {
+  VisitStmt(D);
+  // The NumClauses field was read in ReadStmtFromStream.
+  Record.skipInts(1);
+  VisitOMPExecutableDirective(D);
+}
+
 void ASTStmtReader::VisitOMPOrderedDirective(OMPOrderedDirective *D) {
   VisitStmt(D);
   // The NumClauses field was read in ReadStmtFromStream.
@@ -2278,11 +2536,14 @@ void ASTStmtReader::VisitOMPTargetParallelDirective(
   VisitStmt(D);
   Record.skipInts(1);
   VisitOMPExecutableDirective(D);
+  D->setTaskReductionRefExpr(Record.readSubExpr());
+  D->setHasCancel(Record.readBool());
 }
 
 void ASTStmtReader::VisitOMPTargetParallelForDirective(
     OMPTargetParallelForDirective *D) {
   VisitOMPLoopDirective(D);
+  D->setTaskReductionRefExpr(Record.readSubExpr());
   D->setHasCancel(Record.readInt());
 }
 
@@ -2310,6 +2571,7 @@ void ASTStmtReader::VisitOMPCancelDirective(OMPCancelDirective *D) {
 
 void ASTStmtReader::VisitOMPTaskLoopDirective(OMPTaskLoopDirective *D) {
   VisitOMPLoopDirective(D);
+  D->setHasCancel(Record.readInt());
 }
 
 void ASTStmtReader::VisitOMPTaskLoopSimdDirective(OMPTaskLoopSimdDirective *D) {
@@ -2319,6 +2581,7 @@ void ASTStmtReader::VisitOMPTaskLoopSimdDirective(OMPTaskLoopSimdDirective *D) {
 void ASTStmtReader::VisitOMPMasterTaskLoopDirective(
     OMPMasterTaskLoopDirective *D) {
   VisitOMPLoopDirective(D);
+  D->setHasCancel(Record.readInt());
 }
 
 void ASTStmtReader::VisitOMPMasterTaskLoopSimdDirective(
@@ -2329,6 +2592,7 @@ void ASTStmtReader::VisitOMPMasterTaskLoopSimdDirective(
 void ASTStmtReader::VisitOMPParallelMasterTaskLoopDirective(
     OMPParallelMasterTaskLoopDirective *D) {
   VisitOMPLoopDirective(D);
+  D->setHasCancel(Record.readInt());
 }
 
 void ASTStmtReader::VisitOMPParallelMasterTaskLoopSimdDirective(
@@ -2349,6 +2613,7 @@ void ASTStmtReader::VisitOMPTargetUpdateDirective(OMPTargetUpdateDirective *D) {
 void ASTStmtReader::VisitOMPDistributeParallelForDirective(
     OMPDistributeParallelForDirective *D) {
   VisitOMPLoopDirective(D);
+  D->setTaskReductionRefExpr(Record.readSubExpr());
   D->setHasCancel(Record.readInt());
 }
 
@@ -2389,6 +2654,7 @@ void ASTStmtReader::VisitOMPTeamsDistributeParallelForSimdDirective(
 void ASTStmtReader::VisitOMPTeamsDistributeParallelForDirective(
     OMPTeamsDistributeParallelForDirective *D) {
   VisitOMPLoopDirective(D);
+  D->setTaskReductionRefExpr(Record.readSubExpr());
   D->setHasCancel(Record.readInt());
 }
 
@@ -2407,6 +2673,7 @@ void ASTStmtReader::VisitOMPTargetTeamsDistributeDirective(
 void ASTStmtReader::VisitOMPTargetTeamsDistributeParallelForDirective(
     OMPTargetTeamsDistributeParallelForDirective *D) {
   VisitOMPLoopDirective(D);
+  D->setTaskReductionRefExpr(Record.readSubExpr());
   D->setHasCancel(Record.readInt());
 }
 
@@ -2613,10 +2880,8 @@ Stmt *ASTReader::ReadStmtFromStream(ModuleFile &F) {
 
     case EXPR_CONSTANT:
       S = ConstantExpr::CreateEmpty(
-          Context,
-          static_cast<ConstantExpr::ResultStorageKind>(
-              Record[ASTStmtReader::NumExprFields]),
-          Empty);
+          Context, static_cast<ConstantExpr::ResultStorageKind>(
+                       /*StorageKind=*/Record[ASTStmtReader::NumExprFields]));
       break;
 
     case EXPR_PREDEFINED:
@@ -2639,6 +2904,10 @@ Stmt *ASTReader::ReadStmtFromStream(ModuleFile &F) {
       S = IntegerLiteral::Create(Context, Empty);
       break;
 
+    case EXPR_FIXEDPOINT_LITERAL:
+      S = FixedPointLiteral::Create(Context, Empty);
+      break;
+
     case EXPR_FLOATING_LITERAL:
       S = FloatingLiteral::Create(Context, Empty);
       break;
@@ -2670,7 +2939,8 @@ Stmt *ASTReader::ReadStmtFromStream(ModuleFile &F) {
       break;
 
     case EXPR_UNARY_OPERATOR:
-      S = new (Context) UnaryOperator(Empty);
+      S = UnaryOperator::CreateEmpty(Context,
+                                     Record[ASTStmtReader::NumExprFields]);
       break;
 
     case EXPR_OFFSETOF:
@@ -2687,15 +2957,34 @@ Stmt *ASTReader::ReadStmtFromStream(ModuleFile &F) {
       S = new (Context) ArraySubscriptExpr(Empty);
       break;
 
+    case EXPR_MATRIX_SUBSCRIPT:
+      S = new (Context) MatrixSubscriptExpr(Empty);
+      break;
+
     case EXPR_OMP_ARRAY_SECTION:
       S = new (Context) OMPArraySectionExpr(Empty);
       break;
 
+    case EXPR_OMP_ARRAY_SHAPING:
+      S = OMPArrayShapingExpr::CreateEmpty(
+          Context, Record[ASTStmtReader::NumExprFields]);
+      break;
+
+    case EXPR_OMP_ITERATOR:
+      S = OMPIteratorExpr::CreateEmpty(Context,
+                                       Record[ASTStmtReader::NumExprFields]);
+      break;
+
     case EXPR_CALL:
       S = CallExpr::CreateEmpty(
           Context, /*NumArgs=*/Record[ASTStmtReader::NumExprFields], Empty);
       break;
 
+    case EXPR_RECOVERY:
+      S = RecoveryExpr::CreateEmpty(
+          Context, /*NumArgs=*/Record[ASTStmtReader::NumExprFields]);
+      break;
+
     case EXPR_MEMBER:
       S = MemberExpr::CreateEmpty(Context, Record[ASTStmtReader::NumExprFields],
                                   Record[ASTStmtReader::NumExprFields + 1],
@@ -2704,11 +2993,13 @@ Stmt *ASTReader::ReadStmtFromStream(ModuleFile &F) {
       break;
 
     case EXPR_BINARY_OPERATOR:
-      S = new (Context) BinaryOperator(Empty);
+      S = BinaryOperator::CreateEmpty(Context,
+                                      Record[ASTStmtReader::NumExprFields]);
       break;
 
     case EXPR_COMPOUND_ASSIGN_OPERATOR:
-      S = new (Context) CompoundAssignOperator(Empty);
+      S = CompoundAssignOperator::CreateEmpty(
+          Context, Record[ASTStmtReader::NumExprFields]);
       break;
 
     case EXPR_CONDITIONAL_OPERATOR:
@@ -3054,6 +3345,16 @@ Stmt *ASTReader::ReadStmtFromStream(ModuleFile &F) {
           Context, Record[ASTStmtReader::NumStmtFields], Empty);
       break;
 
+    case STMT_OMP_DEPOBJ_DIRECTIVE:
+      S = OMPDepobjDirective::CreateEmpty(
+          Context, Record[ASTStmtReader::NumStmtFields], Empty);
+      break;
+
+    case STMT_OMP_SCAN_DIRECTIVE:
+      S = OMPScanDirective::CreateEmpty(
+          Context, Record[ASTStmtReader::NumStmtFields], Empty);
+      break;
+
     case STMT_OMP_ORDERED_DIRECTIVE:
       S = OMPOrderedDirective::CreateEmpty(
           Context, Record[ASTStmtReader::NumStmtFields], Empty);
@@ -3331,11 +3632,20 @@ Stmt *ASTReader::ReadStmtFromStream(ModuleFile &F) {
       S = CXXConstCastExpr::CreateEmpty(Context);
       break;
 
+    case EXPR_CXX_ADDRSPACE_CAST:
+      S = CXXAddrspaceCastExpr::CreateEmpty(Context);
+      break;
+
     case EXPR_CXX_FUNCTIONAL_CAST:
       S = CXXFunctionalCastExpr::CreateEmpty(Context,
                        /*PathSize*/ Record[ASTStmtReader::NumExprFields]);
       break;
 
+    case EXPR_BUILTIN_BIT_CAST:
+      assert(Record[ASTStmtReader::NumExprFields] == 0 && "Wrong PathSize!");
+      S = new (Context) BuiltinBitCastExpr(Empty);
+      break;
+
     case EXPR_USER_DEFINED_LITERAL:
       S = UserDefinedLiteral::CreateEmpty(
           Context, /*NumArgs=*/Record[ASTStmtReader::NumExprFields], Empty);
@@ -3566,11 +3876,18 @@ Stmt *ASTReader::ReadStmtFromStream(ModuleFile &F) {
       S = new (Context) DependentCoawaitExpr(Empty);
       break;
 
-    case EXPR_CONCEPT_SPECIALIZATION:
+    case EXPR_CONCEPT_SPECIALIZATION: {
       unsigned numTemplateArgs = Record[ASTStmtReader::NumExprFields];
       S = ConceptSpecializationExpr::Create(Context, Empty, numTemplateArgs);
       break;
-      
+    }
+
+    case EXPR_REQUIRES:
+      unsigned numLocalParameters = Record[ASTStmtReader::NumExprFields];
+      unsigned numRequirement = Record[ASTStmtReader::NumExprFields + 1];
+      S = RequiresExpr::Create(Context, Empty, numLocalParameters,
+                               numRequirement);
+      break;
     }
 
     // We hit a STMT_STOP, so we're done with this expression.
diff --git a/clang/lib/Serialization/ASTWriter.cpp b/clang/lib/Serialization/ASTWriter.cpp
index 6eba48a1abe9..2345a12caeb2 100644
--- a/clang/lib/Serialization/ASTWriter.cpp
+++ b/clang/lib/Serialization/ASTWriter.cpp
@@ -10,14 +10,12 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "clang/AST/OpenMPClause.h"
-#include "clang/Serialization/ASTRecordWriter.h"
 #include "ASTCommon.h"
 #include "ASTReaderInternals.h"
 #include "MultiOnDiskHashTable.h"
-#include "clang/AST/AbstractTypeWriter.h"
 #include "clang/AST/ASTContext.h"
 #include "clang/AST/ASTUnresolvedSet.h"
+#include "clang/AST/AbstractTypeWriter.h"
 #include "clang/AST/Attr.h"
 #include "clang/AST/Decl.h"
 #include "clang/AST/DeclBase.h"
@@ -31,6 +29,7 @@
 #include "clang/AST/ExprCXX.h"
 #include "clang/AST/LambdaCapture.h"
 #include "clang/AST/NestedNameSpecifier.h"
+#include "clang/AST/OpenMPClause.h"
 #include "clang/AST/RawCommentList.h"
 #include "clang/AST/TemplateName.h"
 #include "clang/AST/Type.h"
@@ -65,7 +64,9 @@
 #include "clang/Sema/ObjCMethodList.h"
 #include "clang/Sema/Sema.h"
 #include "clang/Sema/Weak.h"
+#include "clang/Serialization/ASTBitCodes.h"
 #include "clang/Serialization/ASTReader.h"
+#include "clang/Serialization/ASTRecordWriter.h"
 #include "clang/Serialization/InMemoryModuleCache.h"
 #include "clang/Serialization/ModuleFile.h"
 #include "clang/Serialization/ModuleFileExtension.h"
@@ -288,6 +289,25 @@ void TypeLocWriter::VisitExtVectorTypeLoc(ExtVectorTypeLoc TL) {
   Record.AddSourceLocation(TL.getNameLoc());
 }
 
+void TypeLocWriter::VisitConstantMatrixTypeLoc(ConstantMatrixTypeLoc TL) {
+  Record.AddSourceLocation(TL.getAttrNameLoc());
+  SourceRange range = TL.getAttrOperandParensRange();
+  Record.AddSourceLocation(range.getBegin());
+  Record.AddSourceLocation(range.getEnd());
+  Record.AddStmt(TL.getAttrRowOperand());
+  Record.AddStmt(TL.getAttrColumnOperand());
+}
+
+void TypeLocWriter::VisitDependentSizedMatrixTypeLoc(
+    DependentSizedMatrixTypeLoc TL) {
+  Record.AddSourceLocation(TL.getAttrNameLoc());
+  SourceRange range = TL.getAttrOperandParensRange();
+  Record.AddSourceLocation(range.getBegin());
+  Record.AddSourceLocation(range.getEnd());
+  Record.AddStmt(TL.getAttrRowOperand());
+  Record.AddStmt(TL.getAttrColumnOperand());
+}
+
 void TypeLocWriter::VisitFunctionTypeLoc(FunctionTypeLoc TL) {
   Record.AddSourceLocation(TL.getLocalRangeBegin());
   Record.AddSourceLocation(TL.getLParenLoc());
@@ -349,6 +369,18 @@ void TypeLocWriter::VisitUnaryTransformTypeLoc(UnaryTransformTypeLoc TL) {
 
 void TypeLocWriter::VisitAutoTypeLoc(AutoTypeLoc TL) {
   Record.AddSourceLocation(TL.getNameLoc());
+  Record.push_back(TL.isConstrained());
+  if (TL.isConstrained()) {
+    Record.AddNestedNameSpecifierLoc(TL.getNestedNameSpecifierLoc());
+    Record.AddSourceLocation(TL.getTemplateKWLoc());
+    Record.AddSourceLocation(TL.getConceptNameLoc());
+    Record.AddDeclRef(TL.getFoundDecl());
+    Record.AddSourceLocation(TL.getLAngleLoc());
+    Record.AddSourceLocation(TL.getRAngleLoc());
+    for (unsigned I = 0; I < TL.getNumArgs(); ++I)
+      Record.AddTemplateArgumentLocInfo(TL.getTypePtr()->getArg(I).getKind(),
+                                        TL.getArgLocInfo(I));
+  }
 }
 
 void TypeLocWriter::VisitDeducedTemplateSpecializationTypeLoc(
@@ -464,6 +496,14 @@ void TypeLocWriter::VisitPipeTypeLoc(PipeTypeLoc TL) {
   Record.AddSourceLocation(TL.getKWLoc());
 }
 
+void TypeLocWriter::VisitExtIntTypeLoc(clang::ExtIntTypeLoc TL) {
+  Record.AddSourceLocation(TL.getNameLoc());
+}
+void TypeLocWriter::VisitDependentExtIntTypeLoc(
+    clang::DependentExtIntTypeLoc TL) {
+  Record.AddSourceLocation(TL.getNameLoc());
+}
+
 void ASTWriter::WriteTypeAbbrevs() {
   using namespace llvm;
 
@@ -488,6 +528,7 @@ void ASTWriter::WriteTypeAbbrevs() {
   Abv->Add(BitCodeAbbrevOp(0));                         // ProducesResult
   Abv->Add(BitCodeAbbrevOp(0));                         // NoCallerSavedRegs
   Abv->Add(BitCodeAbbrevOp(0));                         // NoCfCheck
+  Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // CmseNSCall
   // FunctionProtoType
   Abv->Add(BitCodeAbbrevOp(0));                         // IsVariadic
   Abv->Add(BitCodeAbbrevOp(0));                         // HasTrailingReturn
@@ -558,6 +599,7 @@ static void AddStmtsExprs(llvm::BitstreamWriter &Stream,
   RECORD(EXPR_PREDEFINED);
   RECORD(EXPR_DECL_REF);
   RECORD(EXPR_INTEGER_LITERAL);
+  RECORD(EXPR_FIXEDPOINT_LITERAL);
   RECORD(EXPR_FLOATING_LITERAL);
   RECORD(EXPR_IMAGINARY_LITERAL);
   RECORD(EXPR_STRING_LITERAL);
@@ -619,6 +661,7 @@ static void AddStmtsExprs(llvm::BitstreamWriter &Stream,
   RECORD(EXPR_CXX_DYNAMIC_CAST);
   RECORD(EXPR_CXX_REINTERPRET_CAST);
   RECORD(EXPR_CXX_CONST_CAST);
+  RECORD(EXPR_CXX_ADDRSPACE_CAST);
   RECORD(EXPR_CXX_FUNCTIONAL_CAST);
   RECORD(EXPR_USER_DEFINED_LITERAL);
   RECORD(EXPR_CXX_STD_INITIALIZER_LIST);
@@ -744,6 +787,7 @@ void ASTWriter::WriteBlockInfoBlock() {
   RECORD(DELETE_EXPRS_TO_ANALYZE);
   RECORD(CUDA_PRAGMA_FORCE_HOST_DEVICE_DEPTH);
   RECORD(PP_CONDITIONAL_STACK);
+  RECORD(DECLS_TO_CHECK_FOR_DEFERRED_DIAGS);
 
   // SourceManager Block.
   BLOCK(SOURCE_MANAGER_BLOCK);
@@ -885,6 +929,7 @@ void ASTWriter::WriteBlockInfoBlock() {
   RECORD(DECL_NON_TYPE_TEMPLATE_PARM);
   RECORD(DECL_TEMPLATE_TEMPLATE_PARM);
   RECORD(DECL_CONCEPT);
+  RECORD(DECL_REQUIRES_EXPR_BODY);
   RECORD(DECL_TYPE_ALIAS_TEMPLATE);
   RECORD(DECL_STATIC_ASSERT);
   RECORD(DECL_CXX_BASE_SPECIFIERS);
@@ -917,6 +962,7 @@ void ASTWriter::WriteBlockInfoBlock() {
 
   BLOCK(UNHASHED_CONTROL_BLOCK);
   RECORD(SIGNATURE);
+  RECORD(AST_BLOCK_HASH);
   RECORD(DIAGNOSTIC_OPTIONS);
   RECORD(DIAG_PRAGMA_MAPPINGS);
 
@@ -982,22 +1028,23 @@ adjustFilenameForRelocatableAST(const char *Filename, StringRef BaseDir) {
   return Filename + Pos;
 }
 
-ASTFileSignature ASTWriter::createSignature(StringRef Bytes) {
-  // Calculate the hash till start of UNHASHED_CONTROL_BLOCK.
+std::pair<ASTFileSignature, ASTFileSignature>
+ASTWriter::createSignature(StringRef AllBytes, StringRef ASTBlockBytes) {
   llvm::SHA1 Hasher;
-  Hasher.update(ArrayRef<uint8_t>(Bytes.bytes_begin(), Bytes.size()));
+  Hasher.update(ASTBlockBytes);
   auto Hash = Hasher.result();
+  ASTFileSignature ASTBlockHash = ASTFileSignature::create(Hash);
 
-  // Convert to an array [5*i32].
-  ASTFileSignature Signature;
-  auto LShift = [&](unsigned char Val, unsigned Shift) {
-    return (uint32_t)Val << Shift;
-  };
-  for (int I = 0; I != 5; ++I)
-    Signature[I] = LShift(Hash[I * 4 + 0], 24) | LShift(Hash[I * 4 + 1], 16) |
-                   LShift(Hash[I * 4 + 2], 8) | LShift(Hash[I * 4 + 3], 0);
+  // Add the remaining bytes (i.e. bytes before the unhashed control block that
+  // are not part of the AST block).
+  Hasher.update(
+      AllBytes.take_front(ASTBlockBytes.bytes_end() - AllBytes.bytes_begin()));
+  Hasher.update(
+      AllBytes.take_back(AllBytes.bytes_end() - ASTBlockBytes.bytes_end()));
+  Hash = Hasher.result();
+  ASTFileSignature Signature = ASTFileSignature::create(Hash);
 
-  return Signature;
+  return std::make_pair(ASTBlockHash, Signature);
 }
 
 ASTFileSignature ASTWriter::writeUnhashedControlBlock(Preprocessor &PP,
@@ -1014,7 +1061,16 @@ ASTFileSignature ASTWriter::writeUnhashedControlBlock(Preprocessor &PP,
   ASTFileSignature Signature;
   if (WritingModule &&
       PP.getHeaderSearchInfo().getHeaderSearchOpts().ModulesHashContent) {
-    Signature = createSignature(StringRef(Buffer.begin(), StartOfUnhashedControl));
+    ASTFileSignature ASTBlockHash;
+    auto ASTBlockStartByte = ASTBlockRange.first >> 3;
+    auto ASTBlockByteLength = (ASTBlockRange.second >> 3) - ASTBlockStartByte;
+    std::tie(ASTBlockHash, Signature) = createSignature(
+        StringRef(Buffer.begin(), StartOfUnhashedControl),
+        StringRef(Buffer.begin() + ASTBlockStartByte, ASTBlockByteLength));
+
+    Record.append(ASTBlockHash.begin(), ASTBlockHash.end());
+    Stream.EmitRecord(AST_BLOCK_HASH, Record);
+    Record.clear();
     Record.append(Signature.begin(), Signature.end());
     Stream.EmitRecord(SIGNATURE, Record);
     Record.clear();
@@ -1119,7 +1175,7 @@ void ASTWriter::WriteControlBlock(Preprocessor &PP, ASTContext &Context,
     BaseDirectory.assign(BaseDir.begin(), BaseDir.end());
   } else if (!isysroot.empty()) {
     // Write out paths relative to the sysroot if possible.
-    BaseDirectory = isysroot;
+    BaseDirectory = std::string(isysroot);
   }
 
   // Module map file
@@ -1705,7 +1761,8 @@ void ASTWriter::WriteHeaderSearch(const HeaderSearch &HS) {
     llvm::SmallVector<Module *, 16> Worklist(1, WritingModule);
     while (!Worklist.empty()) {
       Module *M = Worklist.pop_back_val();
-      if (!M->isAvailable())
+      // We don't care about headers in unimportable submodules.
+      if (M->isUnimportable())
         continue;
 
       // Map to disk files where possible, to pick up any missing stat
@@ -1787,7 +1844,7 @@ void ASTWriter::WriteHeaderSearch(const HeaderSearch &HS) {
       Filename, File->getSize(), getTimestampForOutput(File)
     };
     HeaderFileInfoTrait::data_type Data = {
-      *HFI, HS.getModuleMap().findAllModulesForHeader(File), {}
+      *HFI, HS.getModuleMap().findResolvedModulesForHeader(File), {}
     };
     Generator.insert(Key, Data, GeneratorTrait);
     ++NumHeaderSearchEntries;
@@ -1865,6 +1922,7 @@ void ASTWriter::WriteSourceManagerBlock(SourceManager &SourceMgr,
 
   // Enter the source manager block.
   Stream.EnterSubblock(SOURCE_MANAGER_BLOCK_ID, 4);
+  const uint64_t SourceManagerBlockOffset = Stream.GetCurrentBitNo();
 
   // Abbreviations for the various kinds of source-location entries.
   unsigned SLocFileAbbrv = CreateSLocFileAbbrev(Stream);
@@ -1877,6 +1935,7 @@ void ASTWriter::WriteSourceManagerBlock(SourceManager &SourceMgr,
   // Write out the source location entry table. We skip the first
   // entry, which is always the same dummy entry.
   std::vector<uint32_t> SLocEntryOffsets;
+  uint64_t SLocEntryOffsetsBase = Stream.GetCurrentBitNo();
   RecordData PreloadSLocs;
   SLocEntryOffsets.reserve(SourceMgr.local_sloc_entry_size() - 1);
   for (unsigned I = 1, N = SourceMgr.local_sloc_entry_size();
@@ -1887,7 +1946,9 @@ void ASTWriter::WriteSourceManagerBlock(SourceManager &SourceMgr,
     assert(&SourceMgr.getSLocEntry(FID) == SLoc);
 
     // Record the offset of this source-location entry.
-    SLocEntryOffsets.push_back(Stream.GetCurrentBitNo());
+    uint64_t Offset = Stream.GetCurrentBitNo() - SLocEntryOffsetsBase;
+    assert((Offset >> 32) == 0 && "SLocEntry offset too large");
+    SLocEntryOffsets.push_back(Offset);
 
     // Figure out which record code to use.
     unsigned Code;
@@ -1995,12 +2056,14 @@ void ASTWriter::WriteSourceManagerBlock(SourceManager &SourceMgr,
   Abbrev->Add(BitCodeAbbrevOp(SOURCE_LOCATION_OFFSETS));
   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 16)); // # of slocs
   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 16)); // total size
+  Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 32)); // base offset
   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // offsets
   unsigned SLocOffsetsAbbrev = Stream.EmitAbbrev(std::move(Abbrev));
   {
     RecordData::value_type Record[] = {
         SOURCE_LOCATION_OFFSETS, SLocEntryOffsets.size(),
-        SourceMgr.getNextLocalOffset() - 1 /* skip dummy */};
+        SourceMgr.getNextLocalOffset() - 1 /* skip dummy */,
+        SLocEntryOffsetsBase - SourceManagerBlockOffset};
     Stream.EmitRecordWithBlob(SLocOffsetsAbbrev, Record,
                               bytes(SLocEntryOffsets));
   }
@@ -2077,9 +2140,11 @@ static bool shouldIgnoreMacro(MacroDirective *MD, bool IsModule,
 /// Writes the block containing the serialized form of the
 /// preprocessor.
 void ASTWriter::WritePreprocessor(const Preprocessor &PP, bool IsModule) {
+  uint64_t MacroOffsetsBase = Stream.GetCurrentBitNo();
+
   PreprocessingRecord *PPRec = PP.getPreprocessingRecord();
   if (PPRec)
-    WritePreprocessorDetail(*PPRec);
+    WritePreprocessorDetail(*PPRec, MacroOffsetsBase);
 
   RecordData Record;
   RecordData ModuleMacroRecord;
@@ -2140,7 +2205,8 @@ void ASTWriter::WritePreprocessor(const Preprocessor &PP, bool IsModule) {
   // identifier they belong to.
   for (const IdentifierInfo *Name : MacroIdentifiers) {
     MacroDirective *MD = PP.getLocalMacroDirectiveHistory(Name);
-    auto StartOffset = Stream.GetCurrentBitNo();
+    uint64_t StartOffset = Stream.GetCurrentBitNo() - MacroOffsetsBase;
+    assert((StartOffset >> 32) == 0 && "Macro identifiers offset too large");
 
     // Emit the macro directives in reverse source order.
     for (; MD; MD = MD->getPrevious()) {
@@ -2213,14 +2279,12 @@ void ASTWriter::WritePreprocessor(const Preprocessor &PP, bool IsModule) {
 
     // Record the local offset of this macro.
     unsigned Index = ID - FirstMacroID;
-    if (Index == MacroOffsets.size())
-      MacroOffsets.push_back(Stream.GetCurrentBitNo());
-    else {
-      if (Index > MacroOffsets.size())
-        MacroOffsets.resize(Index + 1);
+    if (Index >= MacroOffsets.size())
+      MacroOffsets.resize(Index + 1);
 
-      MacroOffsets[Index] = Stream.GetCurrentBitNo();
-    }
+    uint64_t Offset = Stream.GetCurrentBitNo() - MacroOffsetsBase;
+    assert((Offset >> 32) == 0 && "Macro offset too large");
+    MacroOffsets[Index] = Offset;
 
     AddIdentifierRef(Name, Record);
     AddSourceLocation(MI->getDefinitionLoc(), Record);
@@ -2271,17 +2335,20 @@ void ASTWriter::WritePreprocessor(const Preprocessor &PP, bool IsModule) {
   Abbrev->Add(BitCodeAbbrevOp(MACRO_OFFSET));
   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // # of macros
   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // first ID
+  Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 32));   // base offset
   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
 
   unsigned MacroOffsetAbbrev = Stream.EmitAbbrev(std::move(Abbrev));
   {
     RecordData::value_type Record[] = {MACRO_OFFSET, MacroOffsets.size(),
-                                       FirstMacroID - NUM_PREDEF_MACRO_IDS};
+                                       FirstMacroID - NUM_PREDEF_MACRO_IDS,
+                                       MacroOffsetsBase - ASTBlockStartOffset};
     Stream.EmitRecordWithBlob(MacroOffsetAbbrev, Record, bytes(MacroOffsets));
   }
 }
 
-void ASTWriter::WritePreprocessorDetail(PreprocessingRecord &PPRec) {
+void ASTWriter::WritePreprocessorDetail(PreprocessingRecord &PPRec,
+                                        uint64_t MacroOffsetsBase) {
   if (PPRec.local_begin() == PPRec.local_end())
     return;
 
@@ -2318,8 +2385,10 @@ void ASTWriter::WritePreprocessorDetail(PreprocessingRecord &PPRec) {
        (void)++E, ++NumPreprocessingRecords, ++NextPreprocessorEntityID) {
     Record.clear();
 
+    uint64_t Offset = Stream.GetCurrentBitNo() - MacroOffsetsBase;
+    assert((Offset >> 32) == 0 && "Preprocessed entity offset too large");
     PreprocessedEntityOffsets.push_back(
-        PPEntityOffset((*E)->getSourceRange(), Stream.GetCurrentBitNo()));
+        PPEntityOffset((*E)->getSourceRange(), Offset));
 
     if (auto *MD = dyn_cast<MacroDefinitionRecord>(*E)) {
       // Record this macro definition's ID.
@@ -2787,15 +2856,15 @@ void ASTWriter::WriteType(QualType T) {
   assert(Idx.getIndex() >= FirstTypeID && "Re-writing a type from a prior AST");
 
   // Emit the type's representation.
-  uint64_t Offset = ASTTypeWriter(*this).write(T);
+  uint64_t Offset = ASTTypeWriter(*this).write(T) - DeclTypesBlockStartOffset;
 
   // Record the offset for this type.
   unsigned Index = Idx.getIndex() - FirstTypeID;
   if (TypeOffsets.size() == Index)
-    TypeOffsets.push_back(Offset);
+    TypeOffsets.emplace_back(Offset);
   else if (TypeOffsets.size() < Index) {
     TypeOffsets.resize(Index + 1);
-    TypeOffsets[Index] = Offset;
+    TypeOffsets[Index].setBitOffset(Offset);
   } else {
     llvm_unreachable("Types emitted in wrong order");
   }
@@ -2862,8 +2931,10 @@ void ASTWriter::WriteTypeDeclOffsets() {
 void ASTWriter::WriteFileDeclIDsMap() {
   using namespace llvm;
 
-  SmallVector<std::pair<FileID, DeclIDInFileInfo *>, 64> SortedFileDeclIDs(
-      FileDeclIDs.begin(), FileDeclIDs.end());
+  SmallVector<std::pair<FileID, DeclIDInFileInfo *>, 64> SortedFileDeclIDs;
+  SortedFileDeclIDs.reserve(FileDeclIDs.size());
+  for (const auto &P : FileDeclIDs)
+    SortedFileDeclIDs.push_back(std::make_pair(P.first, P.second.get()));
   llvm::sort(SortedFileDeclIDs, llvm::less_first());
 
   // Join the vectors of DeclIDs from all files.
@@ -3889,8 +3960,8 @@ void ASTWriter::WriteDeclContextVisibleUpdate(const DeclContext *DC) {
 }
 
 /// Write an FP_PRAGMA_OPTIONS block for the given FPOptions.
-void ASTWriter::WriteFPPragmaOptions(const FPOptions &Opts) {
-  RecordData::value_type Record[] = {Opts.getInt()};
+void ASTWriter::WriteFPPragmaOptions(const FPOptionsOverride &Opts) {
+  RecordData::value_type Record[] = {Opts.getAsOpaqueInt()};
   Stream.EmitRecord(FP_PRAGMA_OPTIONS, Record);
 }
 
@@ -4101,6 +4172,26 @@ void ASTWriter::WritePackPragmaOptions(Sema &SemaRef) {
   Stream.EmitRecord(PACK_PRAGMA_OPTIONS, Record);
 }
 
+/// Write the state of 'pragma float_control' at the end of the module.
+void ASTWriter::WriteFloatControlPragmaOptions(Sema &SemaRef) {
+  // Don't serialize pragma float_control state for modules,
+  // since it should only take effect on a per-submodule basis.
+  if (WritingModule)
+    return;
+
+  RecordData Record;
+  Record.push_back(SemaRef.FpPragmaStack.CurrentValue);
+  AddSourceLocation(SemaRef.FpPragmaStack.CurrentPragmaLocation, Record);
+  Record.push_back(SemaRef.FpPragmaStack.Stack.size());
+  for (const auto &StackEntry : SemaRef.FpPragmaStack.Stack) {
+    Record.push_back(StackEntry.Value);
+    AddSourceLocation(StackEntry.PragmaLocation, Record);
+    AddSourceLocation(StackEntry.PragmaPushLocation, Record);
+    AddString(StackEntry.StackSlotLabel, Record);
+  }
+  Stream.EmitRecord(FLOAT_CONTROL_PRAGMA_OPTIONS, Record);
+}
+
 void ASTWriter::WriteModuleFileExtension(Sema &SemaRef,
                                          ModuleFileExtensionWriter &Writer) {
   // Enter the extension block.
@@ -4261,9 +4352,7 @@ ASTWriter::ASTWriter(llvm::BitstreamWriter &Stream,
   }
 }
 
-ASTWriter::~ASTWriter() {
-  llvm::DeleteContainerSeconds(FileDeclIDs);
-}
+ASTWriter::~ASTWriter() = default;
 
 const LangOptions &ASTWriter::getLangOpts() const {
   assert(WritingAST && "can't determine lang opts when not writing AST");
@@ -4356,6 +4445,8 @@ ASTFileSignature ASTWriter::WriteASTCore(Sema &SemaRef, StringRef isysroot,
   RegisterPredefDecl(Context.VaListTagDecl, PREDEF_DECL_VA_LIST_TAG);
   RegisterPredefDecl(Context.BuiltinMSVaListDecl,
                      PREDEF_DECL_BUILTIN_MS_VA_LIST_ID);
+  RegisterPredefDecl(Context.MSGuidTagDecl,
+                     PREDEF_DECL_BUILTIN_MS_GUID_ID);
   RegisterPredefDecl(Context.ExternCContext, PREDEF_DECL_EXTERN_C_CONTEXT_ID);
   RegisterPredefDecl(Context.MakeIntegerSeqDecl,
                      PREDEF_DECL_MAKE_INTEGER_SEQ_ID);
@@ -4475,7 +4566,10 @@ ASTFileSignature ASTWriter::WriteASTCore(Sema &SemaRef, StringRef isysroot,
   WriteControlBlock(PP, Context, isysroot, OutputFile);
 
   // Write the remaining AST contents.
+  Stream.FlushToWord();
+  ASTBlockRange.first = Stream.GetCurrentBitNo();
   Stream.EnterSubblock(AST_BLOCK_ID, 5);
+  ASTBlockStartOffset = Stream.GetCurrentBitNo();
 
   // This is so that older clang versions, before the introduction
   // of the control block, can read and reject the newer PCH format.
@@ -4606,9 +4700,9 @@ ASTFileSignature ASTWriter::WriteASTCore(Sema &SemaRef, StringRef isysroot,
     //   c++-base-specifiers-id:i32
     //   type-id:i32)
     //
-    // module-kind is the ModuleKind enum value. If it is MK_PrebuiltModule or
-    // MK_ExplicitModule, then the module-name is the module name. Otherwise,
-    // it is the module file name.
+    // module-kind is the ModuleKind enum value. If it is MK_PrebuiltModule,
+    // MK_ExplicitModule or MK_ImplicitModule, then the module-name is the
+    // module name. Otherwise, it is the module file name.
     auto Abbrev = std::make_shared<BitCodeAbbrev>();
     Abbrev->Add(BitCodeAbbrevOp(MODULE_OFFSET_MAP));
     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
@@ -4621,10 +4715,7 @@ ASTFileSignature ASTWriter::WriteASTCore(Sema &SemaRef, StringRef isysroot,
 
         endian::Writer LE(Out, little);
         LE.write<uint8_t>(static_cast<uint8_t>(M.Kind));
-        StringRef Name =
-          M.Kind == MK_PrebuiltModule || M.Kind == MK_ExplicitModule
-          ? M.ModuleName
-          : M.FileName;
+        StringRef Name = M.isModule() ? M.ModuleName : M.FileName;
         LE.write<uint16_t>(Name.size());
         Out.write(Name.data(), Name.size());
 
@@ -4658,11 +4749,17 @@ ASTFileSignature ASTWriter::WriteASTCore(Sema &SemaRef, StringRef isysroot,
                               Buffer.data(), Buffer.size());
   }
 
+  // Build a record containing all of the DeclsToCheckForDeferredDiags.
+  RecordData DeclsToCheckForDeferredDiags;
+  for (auto *D : SemaRef.DeclsToCheckForDeferredDiags)
+    AddDeclRef(D, DeclsToCheckForDeferredDiags);
+
   RecordData DeclUpdatesOffsetsRecord;
 
   // Keep writing types, declarations, and declaration update records
   // until we've emitted all of them.
   Stream.EnterSubblock(DECLTYPES_BLOCK_ID, /*bits for abbreviations*/5);
+  DeclTypesBlockStartOffset = Stream.GetCurrentBitNo();
   WriteTypeAbbrevs();
   WriteDeclAbbrevs();
   do {
@@ -4693,7 +4790,7 @@ ASTFileSignature ASTWriter::WriteASTCore(Sema &SemaRef, StringRef isysroot,
   WriteReferencedSelectorsPool(SemaRef);
   WriteLateParsedTemplates(SemaRef);
   WriteIdentifierTable(PP, SemaRef.IdResolver, isModule);
-  WriteFPPragmaOptions(SemaRef.getFPOptions());
+  WriteFPPragmaOptions(SemaRef.CurFPFeatureOverrides());
   WriteOpenCLExtensions(SemaRef);
   WriteOpenCLExtensionTypes(SemaRef);
   WriteCUDAPragmas(SemaRef);
@@ -4749,6 +4846,11 @@ ASTFileSignature ASTWriter::WriteASTCore(Sema &SemaRef, StringRef isysroot,
   if (!SemaDeclRefs.empty())
     Stream.EmitRecord(SEMA_DECL_REFS, SemaDeclRefs);
 
+  // Write the record containing decls to be checked for deferred diags.
+  if (!DeclsToCheckForDeferredDiags.empty())
+    Stream.EmitRecord(DECLS_TO_CHECK_FOR_DEFERRED_DIAGS,
+        DeclsToCheckForDeferredDiags);
+
   // Write the record containing CUDA-specific declaration references.
   if (!CUDASpecialDeclRefs.empty())
     Stream.EmitRecord(CUDA_SPECIAL_DECL_REFS, CUDASpecialDeclRefs);
@@ -4819,12 +4921,15 @@ ASTFileSignature ASTWriter::WriteASTCore(Sema &SemaRef, StringRef isysroot,
     WriteMSPointersToMembersPragmaOptions(SemaRef);
   }
   WritePackPragmaOptions(SemaRef);
+  WriteFloatControlPragmaOptions(SemaRef);
 
   // Some simple statistics
   RecordData::value_type Record[] = {
       NumStatements, NumMacros, NumLexicalDeclContexts, NumVisibleDeclContexts};
   Stream.EmitRecord(STATISTICS, Record);
   Stream.ExitBlock();
+  Stream.FlushToWord();
+  ASTBlockRange.second = Stream.GetCurrentBitNo();
 
   // Write the module file extension blocks.
   for (const auto &ExtWriter : ModuleFileExtensionWriters)
@@ -5116,7 +5221,7 @@ MacroID ASTWriter::getMacroID(MacroInfo *MI) {
   return MacroIDs[MI];
 }
 
-uint64_t ASTWriter::getMacroDirectivesOffset(const IdentifierInfo *Name) {
+uint32_t ASTWriter::getMacroDirectivesOffset(const IdentifierInfo *Name) {
   return IdentMacroDirectivesOffsetMap.lookup(Name);
 }
 
@@ -5318,9 +5423,9 @@ void ASTWriter::associateDeclWithFile(const Decl *D, DeclID ID) {
     return;
   assert(SM.getSLocEntry(FID).isFile());
 
-  DeclIDInFileInfo *&Info = FileDeclIDs[FID];
+  std::unique_ptr<DeclIDInFileInfo> &Info = FileDeclIDs[FID];
   if (!Info)
-    Info = new DeclIDInFileInfo();
+    Info = std::make_unique<DeclIDInFileInfo>();
 
   std::pair<unsigned, serialization::DeclID> LocDecl(Offset, ID);
   LocDeclIDsTy &Decls = Info->DeclIDs;
@@ -5952,7 +6057,7 @@ void ASTWriter::DeclarationMarkedOpenMPDeclareTarget(const Decl *D,
 void ASTWriter::RedefinedHiddenDefinition(const NamedDecl *D, Module *M) {
   if (Chain && Chain->isProcessingUpdateRecords()) return;
   assert(!WritingAST && "Already writing the AST!");
-  assert(D->isHidden() && "expected a hidden declaration");
+  assert(!D->isUnconditionallyVisible() && "expected a hidden declaration");
   DeclUpdates[D].push_back(DeclUpdate(UPD_DECL_EXPORTED, M));
 }
 
@@ -6012,8 +6117,8 @@ class OMPClauseWriter : public OMPClauseVisitor<OMPClauseWriter> {
 
 public:
   OMPClauseWriter(ASTRecordWriter &Record) : Record(Record) {}
-#define OPENMP_CLAUSE(Name, Class) void Visit##Class(Class *S);
-#include "clang/Basic/OpenMPKinds.def"
+#define OMP_CLAUSE_CLASS(Enum, Str, Class) void Visit##Class(Class *S);
+#include "llvm/Frontend/OpenMP/OMPKinds.def"
   void writeClause(OMPClause *C);
   void VisitOMPClauseWithPreInit(OMPClauseWithPreInit *C);
   void VisitOMPClauseWithPostUpdate(OMPClauseWithPostUpdate *C);
@@ -6026,7 +6131,7 @@ void ASTRecordWriter::writeOMPClause(OMPClause *C) {
 }
 
 void OMPClauseWriter::writeClause(OMPClause *C) {
-  Record.push_back(C->getClauseKind());
+  Record.push_back(unsigned(C->getClauseKind()));
   Visit(C);
   Record.AddSourceLocation(C->getBeginLoc());
   Record.AddSourceLocation(C->getEndLoc());
@@ -6083,8 +6188,13 @@ void OMPClauseWriter::VisitOMPCollapseClause(OMPCollapseClause *C) {
   Record.AddSourceLocation(C->getLParenLoc());
 }
 
+void OMPClauseWriter::VisitOMPDetachClause(OMPDetachClause *C) {
+  Record.AddStmt(C->getEventHandler());
+  Record.AddSourceLocation(C->getLParenLoc());
+}
+
 void OMPClauseWriter::VisitOMPDefaultClause(OMPDefaultClause *C) {
-  Record.push_back(C->getDefaultKind());
+  Record.push_back(unsigned(C->getDefaultKind()));
   Record.AddSourceLocation(C->getLParenLoc());
   Record.AddSourceLocation(C->getDefaultKindKwLoc());
 }
@@ -6128,18 +6238,35 @@ void OMPClauseWriter::VisitOMPReadClause(OMPReadClause *) {}
 
 void OMPClauseWriter::VisitOMPWriteClause(OMPWriteClause *) {}
 
-void OMPClauseWriter::VisitOMPUpdateClause(OMPUpdateClause *) {}
+void OMPClauseWriter::VisitOMPUpdateClause(OMPUpdateClause *C) {
+  Record.push_back(C->isExtended() ? 1 : 0);
+  if (C->isExtended()) {
+    Record.AddSourceLocation(C->getLParenLoc());
+    Record.AddSourceLocation(C->getArgumentLoc());
+    Record.writeEnum(C->getDependencyKind());
+  }
+}
 
 void OMPClauseWriter::VisitOMPCaptureClause(OMPCaptureClause *) {}
 
 void OMPClauseWriter::VisitOMPSeqCstClause(OMPSeqCstClause *) {}
 
+void OMPClauseWriter::VisitOMPAcqRelClause(OMPAcqRelClause *) {}
+
+void OMPClauseWriter::VisitOMPAcquireClause(OMPAcquireClause *) {}
+
+void OMPClauseWriter::VisitOMPReleaseClause(OMPReleaseClause *) {}
+
+void OMPClauseWriter::VisitOMPRelaxedClause(OMPRelaxedClause *) {}
+
 void OMPClauseWriter::VisitOMPThreadsClause(OMPThreadsClause *) {}
 
 void OMPClauseWriter::VisitOMPSIMDClause(OMPSIMDClause *) {}
 
 void OMPClauseWriter::VisitOMPNogroupClause(OMPNogroupClause *) {}
 
+void OMPClauseWriter::VisitOMPDestroyClause(OMPDestroyClause *) {}
+
 void OMPClauseWriter::VisitOMPPrivateClause(OMPPrivateClause *C) {
   Record.push_back(C->varlist_size());
   Record.AddSourceLocation(C->getLParenLoc());
@@ -6194,8 +6321,10 @@ void OMPClauseWriter::VisitOMPSharedClause(OMPSharedClause *C) {
 
 void OMPClauseWriter::VisitOMPReductionClause(OMPReductionClause *C) {
   Record.push_back(C->varlist_size());
+  Record.writeEnum(C->getModifier());
   VisitOMPClauseWithPostUpdate(C);
   Record.AddSourceLocation(C->getLParenLoc());
+  Record.AddSourceLocation(C->getModifierLoc());
   Record.AddSourceLocation(C->getColonLoc());
   Record.AddNestedNameSpecifierLoc(C->getQualifierLoc());
   Record.AddDeclarationNameInfo(C->getNameInfo());
@@ -6209,6 +6338,14 @@ void OMPClauseWriter::VisitOMPReductionClause(OMPReductionClause *C) {
     Record.AddStmt(E);
   for (auto *E : C->reduction_ops())
     Record.AddStmt(E);
+  if (C->getModifier() == clang::OMPC_REDUCTION_inscan) {
+    for (auto *E : C->copy_ops())
+      Record.AddStmt(E);
+    for (auto *E : C->copy_array_temps())
+      Record.AddStmt(E);
+    for (auto *E : C->copy_array_elems())
+      Record.AddStmt(E);
+  }
 }
 
 void OMPClauseWriter::VisitOMPTaskReductionClause(OMPTaskReductionClause *C) {
@@ -6321,10 +6458,16 @@ void OMPClauseWriter::VisitOMPFlushClause(OMPFlushClause *C) {
     Record.AddStmt(VE);
 }
 
+void OMPClauseWriter::VisitOMPDepobjClause(OMPDepobjClause *C) {
+  Record.AddStmt(C->getDepobj());
+  Record.AddSourceLocation(C->getLParenLoc());
+}
+
 void OMPClauseWriter::VisitOMPDependClause(OMPDependClause *C) {
   Record.push_back(C->varlist_size());
   Record.push_back(C->getNumLoops());
   Record.AddSourceLocation(C->getLParenLoc());
+  Record.AddStmt(C->getModifier());
   Record.push_back(C->getDependencyKind());
   Record.AddSourceLocation(C->getDependencyLoc());
   Record.AddSourceLocation(C->getColonLoc());
@@ -6336,7 +6479,9 @@ void OMPClauseWriter::VisitOMPDependClause(OMPDependClause *C) {
 
 void OMPClauseWriter::VisitOMPDeviceClause(OMPDeviceClause *C) {
   VisitOMPClauseWithPreInit(C);
+  Record.writeEnum(C->getModifier());
   Record.AddStmt(C->getDevice());
+  Record.AddSourceLocation(C->getModifierLoc());
   Record.AddSourceLocation(C->getLParenLoc());
 }
 
@@ -6346,7 +6491,7 @@ void OMPClauseWriter::VisitOMPMapClause(OMPMapClause *C) {
   Record.push_back(C->getTotalComponentListNum());
   Record.push_back(C->getTotalComponentsNum());
   Record.AddSourceLocation(C->getLParenLoc());
-  for (unsigned I = 0; I < OMPMapClause::NumberOfModifiers; ++I) {
+  for (unsigned I = 0; I < NumberOfOMPMapClauseModifiers; ++I) {
     Record.push_back(C->getMapTypeModifier(I));
     Record.AddSourceLocation(C->getMapTypeModifierLoc(I));
   }
@@ -6504,6 +6649,26 @@ void OMPClauseWriter::VisitOMPUseDevicePtrClause(OMPUseDevicePtrClause *C) {
   }
 }
 
+void OMPClauseWriter::VisitOMPUseDeviceAddrClause(OMPUseDeviceAddrClause *C) {
+  Record.push_back(C->varlist_size());
+  Record.push_back(C->getUniqueDeclarationsNum());
+  Record.push_back(C->getTotalComponentListNum());
+  Record.push_back(C->getTotalComponentsNum());
+  Record.AddSourceLocation(C->getLParenLoc());
+  for (auto *E : C->varlists())
+    Record.AddStmt(E);
+  for (auto *D : C->all_decls())
+    Record.AddDeclRef(D);
+  for (auto N : C->all_num_lists())
+    Record.push_back(N);
+  for (auto N : C->all_lists_sizes())
+    Record.push_back(N);
+  for (auto &M : C->all_components()) {
+    Record.AddStmt(M.getAssociatedExpression());
+    Record.AddDeclRef(M.getAssociatedDeclaration());
+  }
+}
+
 void OMPClauseWriter::VisitOMPIsDevicePtrClause(OMPIsDevicePtrClause *C) {
   Record.push_back(C->varlist_size());
   Record.push_back(C->getUniqueDeclarationsNum());
@@ -6550,3 +6715,61 @@ void OMPClauseWriter::VisitOMPNontemporalClause(OMPNontemporalClause *C) {
   for (auto *E : C->private_refs())
     Record.AddStmt(E);
 }
+
+void OMPClauseWriter::VisitOMPInclusiveClause(OMPInclusiveClause *C) {
+  Record.push_back(C->varlist_size());
+  Record.AddSourceLocation(C->getLParenLoc());
+  for (auto *VE : C->varlists())
+    Record.AddStmt(VE);
+}
+
+void OMPClauseWriter::VisitOMPExclusiveClause(OMPExclusiveClause *C) {
+  Record.push_back(C->varlist_size());
+  Record.AddSourceLocation(C->getLParenLoc());
+  for (auto *VE : C->varlists())
+    Record.AddStmt(VE);
+}
+
+void OMPClauseWriter::VisitOMPOrderClause(OMPOrderClause *C) {
+  Record.writeEnum(C->getKind());
+  Record.AddSourceLocation(C->getLParenLoc());
+  Record.AddSourceLocation(C->getKindKwLoc());
+}
+
+void OMPClauseWriter::VisitOMPUsesAllocatorsClause(OMPUsesAllocatorsClause *C) {
+  Record.push_back(C->getNumberOfAllocators());
+  Record.AddSourceLocation(C->getLParenLoc());
+  for (unsigned I = 0, E = C->getNumberOfAllocators(); I < E; ++I) {
+    OMPUsesAllocatorsClause::Data Data = C->getAllocatorData(I);
+    Record.AddStmt(Data.Allocator);
+    Record.AddStmt(Data.AllocatorTraits);
+    Record.AddSourceLocation(Data.LParenLoc);
+    Record.AddSourceLocation(Data.RParenLoc);
+  }
+}
+
+void OMPClauseWriter::VisitOMPAffinityClause(OMPAffinityClause *C) {
+  Record.push_back(C->varlist_size());
+  Record.AddSourceLocation(C->getLParenLoc());
+  Record.AddStmt(C->getModifier());
+  Record.AddSourceLocation(C->getColonLoc());
+  for (Expr *E : C->varlists())
+    Record.AddStmt(E);
+}
+
+void ASTRecordWriter::writeOMPTraitInfo(const OMPTraitInfo *TI) {
+  writeUInt32(TI->Sets.size());
+  for (const auto &Set : TI->Sets) {
+    writeEnum(Set.Kind);
+    writeUInt32(Set.Selectors.size());
+    for (const auto &Selector : Set.Selectors) {
+      writeEnum(Selector.Kind);
+      writeBool(Selector.ScoreOrCondition);
+      if (Selector.ScoreOrCondition)
+        writeExprRef(Selector.ScoreOrCondition);
+      writeUInt32(Selector.Properties.size());
+      for (const auto &Property : Selector.Properties)
+        writeEnum(Property.Kind);
+    }
+  }
+}
diff --git a/clang/lib/Serialization/ASTWriterDecl.cpp b/clang/lib/Serialization/ASTWriterDecl.cpp
index b2a8c118d401..eecdf89c791a 100644
--- a/clang/lib/Serialization/ASTWriterDecl.cpp
+++ b/clang/lib/Serialization/ASTWriterDecl.cpp
@@ -95,6 +95,7 @@ namespace clang {
     void VisitCXXConversionDecl(CXXConversionDecl *D);
     void VisitFieldDecl(FieldDecl *D);
     void VisitMSPropertyDecl(MSPropertyDecl *D);
+    void VisitMSGuidDecl(MSGuidDecl *D);
     void VisitIndirectFieldDecl(IndirectFieldDecl *D);
     void VisitVarDecl(VarDecl *D);
     void VisitImplicitParamDecl(ImplicitParamDecl *D);
@@ -104,6 +105,7 @@ namespace clang {
     void VisitNonTypeTemplateParmDecl(NonTypeTemplateParmDecl *D);
     void VisitTemplateDecl(TemplateDecl *D);
     void VisitConceptDecl(ConceptDecl *D);
+    void VisitRequiresExprBodyDecl(RequiresExprBodyDecl *D);
     void VisitRedeclarableTemplateDecl(RedeclarableTemplateDecl *D);
     void VisitClassTemplateDecl(ClassTemplateDecl *D);
     void VisitVarTemplateDecl(VarTemplateDecl *D);
@@ -952,6 +954,17 @@ void ASTDeclWriter::VisitMSPropertyDecl(MSPropertyDecl *D) {
   Code = serialization::DECL_MS_PROPERTY;
 }
 
+void ASTDeclWriter::VisitMSGuidDecl(MSGuidDecl *D) {
+  VisitValueDecl(D);
+  MSGuidDecl::Parts Parts = D->getParts();
+  Record.push_back(Parts.Part1);
+  Record.push_back(Parts.Part2);
+  Record.push_back(Parts.Part3);
+  for (auto C : Parts.Part4And5)
+    Record.push_back(C);
+  Code = serialization::DECL_MS_GUID;
+}
+
 void ASTDeclWriter::VisitIndirectFieldDecl(IndirectFieldDecl *D) {
   VisitValueDecl(D);
   Record.push_back(D->getChainingSize());
@@ -1010,16 +1023,15 @@ void ASTDeclWriter::VisitVarDecl(VarDecl *D) {
 
   if (D->getStorageDuration() == SD_Static) {
     bool ModulesCodegen = false;
-    if (!D->getDescribedVarTemplate() && !D->getMemberSpecializationInfo() &&
+    if (Writer.WritingModule &&
+        !D->getDescribedVarTemplate() && !D->getMemberSpecializationInfo() &&
         !isa<VarTemplateSpecializationDecl>(D)) {
       // When building a C++ Modules TS module interface unit, a strong
       // definition in the module interface is provided by the compilation of
       // that module interface unit, not by its users. (Inline variables are
       // still emitted in module users.)
       ModulesCodegen =
-          (((Writer.WritingModule &&
-             Writer.WritingModule->Kind == Module::ModuleInterfaceUnit) ||
-            Writer.Context->getLangOpts().BuildingPCHWithObjectFile) &&
+          (Writer.WritingModule->Kind == Module::ModuleInterfaceUnit &&
            Writer.Context->GetGVALinkageForVariable(D) == GVA_StrongExternal);
     }
     Record.push_back(ModulesCodegen);
@@ -1088,8 +1100,6 @@ void ASTDeclWriter::VisitParmVarDecl(ParmVarDecl *D) {
     Record.AddStmt(D->getUninstantiatedDefaultArg());
   Code = serialization::DECL_PARM_VAR;
 
-  assert(!D->isARCPseudoStrong()); // can be true of ImplicitParamDecl
-
   // If the assumptions about the DECL_PARM_VAR abbrev are true, use it.  Here
   // we dynamically check for the properties that we optimize for, but don't
   // know are true of all PARM_VAR_DECLs.
@@ -1481,6 +1491,10 @@ void ASTDeclWriter::VisitConceptDecl(ConceptDecl *D) {
   Code = serialization::DECL_CONCEPT;
 }
 
+void ASTDeclWriter::VisitRequiresExprBodyDecl(RequiresExprBodyDecl *D) {
+  Code = serialization::DECL_REQUIRES_EXPR_BODY;
+}
+
 void ASTDeclWriter::VisitRedeclarableTemplateDecl(RedeclarableTemplateDecl *D) {
   VisitRedeclarable(D);
 
@@ -1670,6 +1684,8 @@ void ASTDeclWriter::VisitNonTypeTemplateParmDecl(NonTypeTemplateParmDecl *D) {
   // For an expanded parameter pack, record the number of expansion types here
   // so that it's easier for deserialization to allocate the right amount of
   // memory.
+  Expr *TypeConstraint = D->getPlaceholderTypeConstraint();
+  Record.push_back(!!TypeConstraint);
   if (D->isExpandedParameterPack())
     Record.push_back(D->getNumExpansionTypes());
 
@@ -1677,6 +1693,8 @@ void ASTDeclWriter::VisitNonTypeTemplateParmDecl(NonTypeTemplateParmDecl *D) {
   // TemplateParmPosition.
   Record.push_back(D->getDepth());
   Record.push_back(D->getPosition());
+  if (TypeConstraint)
+    Record.AddStmt(TypeConstraint);
 
   if (D->isExpandedParameterPack()) {
     for (unsigned I = 0, N = D->getNumExpansionTypes(); I != N; ++I) {
@@ -2101,7 +2119,7 @@ void ASTWriter::WriteDeclAbbrevs() {
   Abv->Add(BitCodeAbbrevOp(0));                       // SClass
   Abv->Add(BitCodeAbbrevOp(0));                       // TSCSpec
   Abv->Add(BitCodeAbbrevOp(0));                       // InitStyle
-  Abv->Add(BitCodeAbbrevOp(0));                       // ARCPseudoStrong
+  Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isARCPseudoStrong
   Abv->Add(BitCodeAbbrevOp(0));                       // Linkage
   Abv->Add(BitCodeAbbrevOp(0));                       // HasInit
   Abv->Add(BitCodeAbbrevOp(0));                   // HasMemberSpecializationInfo
@@ -2266,13 +2284,13 @@ void ASTWriter::WriteDeclAbbrevs() {
   Abv = std::make_shared<BitCodeAbbrev>();
   Abv->Add(BitCodeAbbrevOp(serialization::EXPR_DECL_REF));
   //Stmt
-  Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsOMPStructuredBlock
   // Expr
   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //TypeDependent
   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //ValueDependent
   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //InstantiationDependent
   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //UnexpandedParamPack
+  Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //ContainsErrors
   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetValueKind
   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetObjectKind
   //DeclRefExpr
@@ -2290,13 +2308,13 @@ void ASTWriter::WriteDeclAbbrevs() {
   Abv = std::make_shared<BitCodeAbbrev>();
   Abv->Add(BitCodeAbbrevOp(serialization::EXPR_INTEGER_LITERAL));
   //Stmt
-  Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsOMPStructuredBlock
   // Expr
   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //TypeDependent
   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //ValueDependent
   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //InstantiationDependent
   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //UnexpandedParamPack
+  Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //ContainsErrors
   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetValueKind
   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetObjectKind
   //Integer Literal
@@ -2309,13 +2327,13 @@ void ASTWriter::WriteDeclAbbrevs() {
   Abv = std::make_shared<BitCodeAbbrev>();
   Abv->Add(BitCodeAbbrevOp(serialization::EXPR_CHARACTER_LITERAL));
   //Stmt
-  Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsOMPStructuredBlock
   // Expr
   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //TypeDependent
   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //ValueDependent
   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //InstantiationDependent
   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //UnexpandedParamPack
+  Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //ContainsErrors
   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetValueKind
   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetObjectKind
   //Character Literal
@@ -2328,13 +2346,13 @@ void ASTWriter::WriteDeclAbbrevs() {
   Abv = std::make_shared<BitCodeAbbrev>();
   Abv->Add(BitCodeAbbrevOp(serialization::EXPR_IMPLICIT_CAST));
   // Stmt
-  Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsOMPStructuredBlock
   // Expr
   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //TypeDependent
   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //ValueDependent
   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //InstantiationDependent
   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //UnexpandedParamPack
+  Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //ContainsErrors
   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetValueKind
   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetObjectKind
   // CastExpr
@@ -2414,12 +2432,12 @@ void ASTWriter::WriteDecl(ASTContext &Context, Decl *D) {
   SourceLocation Loc = D->getLocation();
   unsigned Index = ID - FirstDeclID;
   if (DeclOffsets.size() == Index)
-    DeclOffsets.push_back(DeclOffset(Loc, Offset));
+    DeclOffsets.emplace_back(Loc, Offset, DeclTypesBlockStartOffset);
   else if (DeclOffsets.size() < Index) {
     // FIXME: Can/should this happen?
     DeclOffsets.resize(Index+1);
     DeclOffsets[Index].setLocation(Loc);
-    DeclOffsets[Index].BitOffset = Offset;
+    DeclOffsets[Index].setBitOffset(Offset, DeclTypesBlockStartOffset);
   } else {
     llvm_unreachable("declarations should be emitted in ID order");
   }
@@ -2442,9 +2460,8 @@ void ASTRecordWriter::AddFunctionDefinition(const FunctionDecl *FD) {
   bool ModulesCodegen = false;
   if (!FD->isDependentContext()) {
     Optional<GVALinkage> Linkage;
-    if ((Writer->WritingModule &&
-         Writer->WritingModule->Kind == Module::ModuleInterfaceUnit) ||
-        Writer->Context->getLangOpts().BuildingPCHWithObjectFile) {
+    if (Writer->WritingModule &&
+        Writer->WritingModule->Kind == Module::ModuleInterfaceUnit) {
       // When building a C++ Modules TS module interface unit, a strong
       // definition in the module interface is provided by the compilation of
       // that module interface unit, not by its users. (Inline functions are
diff --git a/clang/lib/Serialization/ASTWriterStmt.cpp b/clang/lib/Serialization/ASTWriterStmt.cpp
index 9231f3b2b9ba..0767b3a24bf2 100644
--- a/clang/lib/Serialization/ASTWriterStmt.cpp
+++ b/clang/lib/Serialization/ASTWriterStmt.cpp
@@ -11,7 +11,9 @@
 ///
 //===----------------------------------------------------------------------===//
 
+#include "clang/AST/ExprOpenMP.h"
 #include "clang/Serialization/ASTRecordWriter.h"
+#include "clang/Sema/DeclSpec.h"
 #include "clang/AST/ASTContext.h"
 #include "clang/AST/DeclCXX.h"
 #include "clang/AST/DeclObjC.h"
@@ -67,7 +69,6 @@ void ASTStmtWriter::AddTemplateKWAndArgsInfo(
 }
 
 void ASTStmtWriter::VisitStmt(Stmt *S) {
-  Record.push_back(S->StmtBits.IsOMPStructuredBlock);
 }
 
 void ASTStmtWriter::VisitNullStmt(NullStmt *S) {
@@ -193,6 +194,8 @@ void ASTStmtWriter::VisitWhileStmt(WhileStmt *S) {
     Record.AddDeclRef(S->getConditionVariable());
 
   Record.AddSourceLocation(S->getWhileLoc());
+  Record.AddSourceLocation(S->getLParenLoc());
+  Record.AddSourceLocation(S->getRParenLoc());
   Code = serialization::STMT_WHILE;
 }
 
@@ -388,19 +391,9 @@ void ASTStmtWriter::VisitDependentCoawaitExpr(DependentCoawaitExpr *E) {
   Code = serialization::EXPR_DEPENDENT_COAWAIT;
 }
 
-void ASTStmtWriter::VisitConceptSpecializationExpr(
-        ConceptSpecializationExpr *E) {
-  VisitExpr(E);
-  ArrayRef<TemplateArgument> TemplateArgs = E->getTemplateArguments();
-  Record.push_back(TemplateArgs.size());
-  Record.AddNestedNameSpecifierLoc(E->getNestedNameSpecifierLoc());
-  Record.AddSourceLocation(E->getTemplateKWLoc());
-  Record.AddDeclarationNameInfo(E->getConceptNameInfo());
-  Record.AddDeclRef(E->getNamedConcept());
-  Record.AddASTTemplateArgumentListInfo(E->getTemplateArgsAsWritten());
-  for (const TemplateArgument &Arg : TemplateArgs)
-    Record.AddTemplateArgument(Arg);
-  const ASTConstraintSatisfaction &Satisfaction = E->getSatisfaction();
+static void
+addConstraintSatisfaction(ASTRecordWriter &Record,
+                          const ASTConstraintSatisfaction &Satisfaction) {
   Record.push_back(Satisfaction.IsSatisfied);
   if (!Satisfaction.IsSatisfied) {
     Record.push_back(Satisfaction.NumRecords);
@@ -418,10 +411,99 @@ void ASTStmtWriter::VisitConceptSpecializationExpr(
       }
     }
   }
+}
+
+static void
+addSubstitutionDiagnostic(
+    ASTRecordWriter &Record,
+    const concepts::Requirement::SubstitutionDiagnostic *D) {
+  Record.AddString(D->SubstitutedEntity);
+  Record.AddSourceLocation(D->DiagLoc);
+  Record.AddString(D->DiagMessage);
+}
+
+void ASTStmtWriter::VisitConceptSpecializationExpr(
+        ConceptSpecializationExpr *E) {
+  VisitExpr(E);
+  ArrayRef<TemplateArgument> TemplateArgs = E->getTemplateArguments();
+  Record.push_back(TemplateArgs.size());
+  Record.AddNestedNameSpecifierLoc(E->getNestedNameSpecifierLoc());
+  Record.AddSourceLocation(E->getTemplateKWLoc());
+  Record.AddDeclarationNameInfo(E->getConceptNameInfo());
+  Record.AddDeclRef(E->getNamedConcept());
+  Record.AddDeclRef(E->getFoundDecl());
+  Record.AddASTTemplateArgumentListInfo(E->getTemplateArgsAsWritten());
+  for (const TemplateArgument &Arg : TemplateArgs)
+    Record.AddTemplateArgument(Arg);
+  if (!E->isValueDependent())
+    addConstraintSatisfaction(Record, E->getSatisfaction());
 
   Code = serialization::EXPR_CONCEPT_SPECIALIZATION;
 }
 
+void ASTStmtWriter::VisitRequiresExpr(RequiresExpr *E) {
+  VisitExpr(E);
+  Record.push_back(E->getLocalParameters().size());
+  Record.push_back(E->getRequirements().size());
+  Record.AddSourceLocation(E->RequiresExprBits.RequiresKWLoc);
+  Record.push_back(E->RequiresExprBits.IsSatisfied);
+  Record.AddDeclRef(E->getBody());
+  for (ParmVarDecl *P : E->getLocalParameters())
+    Record.AddDeclRef(P);
+  for (concepts::Requirement *R : E->getRequirements()) {
+    if (auto *TypeReq = dyn_cast<concepts::TypeRequirement>(R)) {
+      Record.push_back(concepts::Requirement::RK_Type);
+      Record.push_back(TypeReq->Status);
+      if (TypeReq->Status == concepts::TypeRequirement::SS_SubstitutionFailure)
+        addSubstitutionDiagnostic(Record, TypeReq->getSubstitutionDiagnostic());
+      else
+        Record.AddTypeSourceInfo(TypeReq->getType());
+    } else if (auto *ExprReq = dyn_cast<concepts::ExprRequirement>(R)) {
+      Record.push_back(ExprReq->getKind());
+      Record.push_back(ExprReq->Status);
+      if (ExprReq->isExprSubstitutionFailure()) {
+        addSubstitutionDiagnostic(Record,
+         ExprReq->Value.get<concepts::Requirement::SubstitutionDiagnostic *>());
+      } else
+        Record.AddStmt(ExprReq->Value.get<Expr *>());
+      if (ExprReq->getKind() == concepts::Requirement::RK_Compound) {
+        Record.AddSourceLocation(ExprReq->NoexceptLoc);
+        const auto &RetReq = ExprReq->getReturnTypeRequirement();
+        if (RetReq.isSubstitutionFailure()) {
+          Record.push_back(2);
+          addSubstitutionDiagnostic(Record, RetReq.getSubstitutionDiagnostic());
+        } else if (RetReq.isTypeConstraint()) {
+          Record.push_back(1);
+          Record.AddTemplateParameterList(
+              RetReq.getTypeConstraintTemplateParameterList());
+          if (ExprReq->Status >=
+              concepts::ExprRequirement::SS_ConstraintsNotSatisfied)
+            Record.AddStmt(
+                ExprReq->getReturnTypeRequirementSubstitutedConstraintExpr());
+        } else {
+          assert(RetReq.isEmpty());
+          Record.push_back(0);
+        }
+      }
+    } else {
+      auto *NestedReq = cast<concepts::NestedRequirement>(R);
+      Record.push_back(concepts::Requirement::RK_Nested);
+      Record.push_back(NestedReq->isSubstitutionFailure());
+      if (NestedReq->isSubstitutionFailure()){
+        addSubstitutionDiagnostic(Record,
+                                  NestedReq->getSubstitutionDiagnostic());
+      } else {
+        Record.AddStmt(NestedReq->Value.get<Expr *>());
+        if (!NestedReq->isDependent())
+          addConstraintSatisfaction(Record, *NestedReq->Satisfaction);
+      }
+    }
+  }
+  Record.AddSourceLocation(E->getEndLoc());
+
+  Code = serialization::EXPR_REQUIRES;
+}
+
 
 void ASTStmtWriter::VisitCapturedStmt(CapturedStmt *S) {
   VisitStmt(S);
@@ -461,22 +543,34 @@ void ASTStmtWriter::VisitExpr(Expr *E) {
   Record.push_back(E->isValueDependent());
   Record.push_back(E->isInstantiationDependent());
   Record.push_back(E->containsUnexpandedParameterPack());
+  Record.push_back(E->containsErrors());
   Record.push_back(E->getValueKind());
   Record.push_back(E->getObjectKind());
 }
 
 void ASTStmtWriter::VisitConstantExpr(ConstantExpr *E) {
   VisitExpr(E);
-  Record.push_back(static_cast<uint64_t>(E->ConstantExprBits.ResultKind));
+  Record.push_back(E->ConstantExprBits.ResultKind);
+
+  Record.push_back(E->ConstantExprBits.APValueKind);
+  Record.push_back(E->ConstantExprBits.IsUnsigned);
+  Record.push_back(E->ConstantExprBits.BitWidth);
+  // HasCleanup not serialized since we can just query the APValue.
+  Record.push_back(E->ConstantExprBits.IsImmediateInvocation);
+
   switch (E->ConstantExprBits.ResultKind) {
+  case ConstantExpr::RSK_None:
+    break;
   case ConstantExpr::RSK_Int64:
     Record.push_back(E->Int64Result());
-    Record.push_back(E->ConstantExprBits.IsUnsigned |
-                     E->ConstantExprBits.BitWidth << 1);
     break;
   case ConstantExpr::RSK_APValue:
     Record.AddAPValue(E->APValueResult());
+    break;
+  default:
+    llvm_unreachable("unexpected ResultKind!");
   }
+
   Record.AddStmt(E->getSubExpr());
   Code = serialization::EXPR_CONSTANT;
 }
@@ -548,8 +642,9 @@ void ASTStmtWriter::VisitIntegerLiteral(IntegerLiteral *E) {
 void ASTStmtWriter::VisitFixedPointLiteral(FixedPointLiteral *E) {
   VisitExpr(E);
   Record.AddSourceLocation(E->getLocation());
+  Record.push_back(E->getScale());
   Record.AddAPInt(E->getValue());
-  Code = serialization::EXPR_INTEGER_LITERAL;
+  Code = serialization::EXPR_FIXEDPOINT_LITERAL;
 }
 
 void ASTStmtWriter::VisitFloatingLiteral(FloatingLiteral *E) {
@@ -620,10 +715,16 @@ void ASTStmtWriter::VisitParenListExpr(ParenListExpr *E) {
 
 void ASTStmtWriter::VisitUnaryOperator(UnaryOperator *E) {
   VisitExpr(E);
+  bool HasFPFeatures = E->hasStoredFPFeatures();
+  // Write this first for easy access when deserializing, as they affect the
+  // size of the UnaryOperator.
+  Record.push_back(HasFPFeatures);
   Record.AddStmt(E->getSubExpr());
   Record.push_back(E->getOpcode()); // FIXME: stable encoding
   Record.AddSourceLocation(E->getOperatorLoc());
   Record.push_back(E->canOverflow());
+  if (HasFPFeatures)
+    Record.push_back(E->getStoredFPFeatures().getAsOpaqueInt());
   Code = serialization::EXPR_UNARY_OPERATOR;
 }
 
@@ -684,16 +785,66 @@ void ASTStmtWriter::VisitArraySubscriptExpr(ArraySubscriptExpr *E) {
   Code = serialization::EXPR_ARRAY_SUBSCRIPT;
 }
 
+void ASTStmtWriter::VisitMatrixSubscriptExpr(MatrixSubscriptExpr *E) {
+  VisitExpr(E);
+  Record.AddStmt(E->getBase());
+  Record.AddStmt(E->getRowIdx());
+  Record.AddStmt(E->getColumnIdx());
+  Record.AddSourceLocation(E->getRBracketLoc());
+  Code = serialization::EXPR_ARRAY_SUBSCRIPT;
+}
+
 void ASTStmtWriter::VisitOMPArraySectionExpr(OMPArraySectionExpr *E) {
   VisitExpr(E);
   Record.AddStmt(E->getBase());
   Record.AddStmt(E->getLowerBound());
   Record.AddStmt(E->getLength());
-  Record.AddSourceLocation(E->getColonLoc());
+  Record.AddStmt(E->getStride());
+  Record.AddSourceLocation(E->getColonLocFirst());
+  Record.AddSourceLocation(E->getColonLocSecond());
   Record.AddSourceLocation(E->getRBracketLoc());
   Code = serialization::EXPR_OMP_ARRAY_SECTION;
 }
 
+void ASTStmtWriter::VisitOMPArrayShapingExpr(OMPArrayShapingExpr *E) {
+  VisitExpr(E);
+  Record.push_back(E->getDimensions().size());
+  Record.AddStmt(E->getBase());
+  for (Expr *Dim : E->getDimensions())
+    Record.AddStmt(Dim);
+  for (SourceRange SR : E->getBracketsRanges())
+    Record.AddSourceRange(SR);
+  Record.AddSourceLocation(E->getLParenLoc());
+  Record.AddSourceLocation(E->getRParenLoc());
+  Code = serialization::EXPR_OMP_ARRAY_SHAPING;
+}
+
+void ASTStmtWriter::VisitOMPIteratorExpr(OMPIteratorExpr *E) {
+  VisitExpr(E);
+  Record.push_back(E->numOfIterators());
+  Record.AddSourceLocation(E->getIteratorKwLoc());
+  Record.AddSourceLocation(E->getLParenLoc());
+  Record.AddSourceLocation(E->getRParenLoc());
+  for (unsigned I = 0, End = E->numOfIterators(); I < End; ++I) {
+    Record.AddDeclRef(E->getIteratorDecl(I));
+    Record.AddSourceLocation(E->getAssignLoc(I));
+    OMPIteratorExpr::IteratorRange Range = E->getIteratorRange(I);
+    Record.AddStmt(Range.Begin);
+    Record.AddStmt(Range.End);
+    Record.AddStmt(Range.Step);
+    Record.AddSourceLocation(E->getColonLoc(I));
+    if (Range.Step)
+      Record.AddSourceLocation(E->getSecondColonLoc(I));
+    // Serialize helpers
+    OMPIteratorHelperData &HD = E->getHelper(I);
+    Record.AddDeclRef(HD.CounterVD);
+    Record.AddStmt(HD.Upper);
+    Record.AddStmt(HD.Update);
+    Record.AddStmt(HD.CounterUpdate);
+  }
+  Code = serialization::EXPR_OMP_ITERATOR;
+}
+
 void ASTStmtWriter::VisitCallExpr(CallExpr *E) {
   VisitExpr(E);
   Record.push_back(E->getNumArgs());
@@ -706,6 +857,16 @@ void ASTStmtWriter::VisitCallExpr(CallExpr *E) {
   Code = serialization::EXPR_CALL;
 }
 
+void ASTStmtWriter::VisitRecoveryExpr(RecoveryExpr *E) {
+  VisitExpr(E);
+  Record.push_back(std::distance(E->children().begin(), E->children().end()));
+  Record.AddSourceLocation(E->getBeginLoc());
+  Record.AddSourceLocation(E->getEndLoc());
+  for (Stmt *Child : E->children())
+    Record.AddStmt(Child);
+  Code = serialization::EXPR_RECOVERY;
+}
+
 void ASTStmtWriter::VisitMemberExpr(MemberExpr *E) {
   VisitExpr(E);
 
@@ -788,11 +949,16 @@ void ASTStmtWriter::VisitCastExpr(CastExpr *E) {
 
 void ASTStmtWriter::VisitBinaryOperator(BinaryOperator *E) {
   VisitExpr(E);
+  bool HasFPFeatures = E->hasStoredFPFeatures();
+  // Write this first for easy access when deserializing, as they affect the
+  // size of the UnaryOperator.
+  Record.push_back(HasFPFeatures);
+  Record.push_back(E->getOpcode()); // FIXME: stable encoding
   Record.AddStmt(E->getLHS());
   Record.AddStmt(E->getRHS());
-  Record.push_back(E->getOpcode()); // FIXME: stable encoding
   Record.AddSourceLocation(E->getOperatorLoc());
-  Record.push_back(E->getFPFeatures().getInt());
+  if (HasFPFeatures)
+    Record.push_back(E->getStoredFPFeatures().getAsOpaqueInt());
   Code = serialization::EXPR_BINARY_OPERATOR;
 }
 
@@ -989,6 +1155,7 @@ void ASTStmtWriter::VisitStmtExpr(StmtExpr *E) {
   Record.AddStmt(E->getSubStmt());
   Record.AddSourceLocation(E->getLParenLoc());
   Record.AddSourceLocation(E->getRParenLoc());
+  Record.push_back(E->getTemplateDepth());
   Code = serialization::EXPR_STMT;
 }
 
@@ -1382,8 +1549,8 @@ void ASTStmtWriter::VisitMSDependentExistsStmt(MSDependentExistsStmt *S) {
 void ASTStmtWriter::VisitCXXOperatorCallExpr(CXXOperatorCallExpr *E) {
   VisitCallExpr(E);
   Record.push_back(E->getOperator());
-  Record.push_back(E->getFPFeatures().getInt());
   Record.AddSourceRange(E->Range);
+  Record.push_back(E->getFPFeatures().getAsOpaqueInt());
   Code = serialization::EXPR_CXX_OPERATOR_CALL;
 }
 
@@ -1437,12 +1604,12 @@ void ASTStmtWriter::VisitCXXTemporaryObjectExpr(CXXTemporaryObjectExpr *E) {
 
 void ASTStmtWriter::VisitLambdaExpr(LambdaExpr *E) {
   VisitExpr(E);
-  Record.push_back(E->NumCaptures);
+  Record.push_back(E->LambdaExprBits.NumCaptures);
   Record.AddSourceRange(E->IntroducerRange);
-  Record.push_back(E->CaptureDefault); // FIXME: stable encoding
+  Record.push_back(E->LambdaExprBits.CaptureDefault); // FIXME: stable encoding
   Record.AddSourceLocation(E->CaptureDefaultLoc);
-  Record.push_back(E->ExplicitParams);
-  Record.push_back(E->ExplicitResultType);
+  Record.push_back(E->LambdaExprBits.ExplicitParams);
+  Record.push_back(E->LambdaExprBits.ExplicitResultType);
   Record.AddSourceLocation(E->ClosingBrace);
 
   // Add capture initializers.
@@ -1452,6 +1619,9 @@ void ASTStmtWriter::VisitLambdaExpr(LambdaExpr *E) {
     Record.AddStmt(*C);
   }
 
+  // Don't serialize the body. It belongs to the call operator declaration.
+  // LambdaExpr only stores a copy of the Stmt *.
+
   Code = serialization::EXPR_LAMBDA;
 }
 
@@ -1487,6 +1657,11 @@ void ASTStmtWriter::VisitCXXConstCastExpr(CXXConstCastExpr *E) {
   Code = serialization::EXPR_CXX_CONST_CAST;
 }
 
+void ASTStmtWriter::VisitCXXAddrspaceCastExpr(CXXAddrspaceCastExpr *E) {
+  VisitCXXNamedCastExpr(E);
+  Code = serialization::EXPR_CXX_ADDRSPACE_CAST;
+}
+
 void ASTStmtWriter::VisitCXXFunctionalCastExpr(CXXFunctionalCastExpr *E) {
   VisitExplicitCastExpr(E);
   Record.AddSourceLocation(E->getLParenLoc());
@@ -1498,6 +1673,7 @@ void ASTStmtWriter::VisitBuiltinBitCastExpr(BuiltinBitCastExpr *E) {
   VisitExplicitCastExpr(E);
   Record.AddSourceLocation(E->getBeginLoc());
   Record.AddSourceLocation(E->getEndLoc());
+  Code = serialization::EXPR_BUILTIN_BIT_CAST;
 }
 
 void ASTStmtWriter::VisitUserDefinedLiteral(UserDefinedLiteral *E) {
@@ -1641,8 +1817,15 @@ void ASTStmtWriter::VisitCXXPseudoDestructorExpr(CXXPseudoDestructorExpr *E) {
 void ASTStmtWriter::VisitExprWithCleanups(ExprWithCleanups *E) {
   VisitExpr(E);
   Record.push_back(E->getNumObjects());
-  for (unsigned i = 0, e = E->getNumObjects(); i != e; ++i)
-    Record.AddDeclRef(E->getObject(i));
+  for (auto &Obj : E->getObjects()) {
+    if (auto *BD = Obj.dyn_cast<BlockDecl *>()) {
+      Record.push_back(serialization::COK_Block);
+      Record.AddDeclRef(BD);
+    } else if (auto *CLE = Obj.dyn_cast<CompoundLiteralExpr *>()) {
+      Record.push_back(serialization::COK_CompoundLiteral);
+      Record.AddStmt(CLE);
+    }
+  }
 
   Record.push_back(E->cleanupsHaveSideEffects());
   Record.AddStmt(E->getSubExpr());
@@ -1931,7 +2114,7 @@ void ASTStmtWriter::VisitMSPropertySubscriptExpr(MSPropertySubscriptExpr *E) {
 void ASTStmtWriter::VisitCXXUuidofExpr(CXXUuidofExpr *E) {
   VisitExpr(E);
   Record.AddSourceRange(E->getSourceRange());
-  Record.AddString(E->getUuidStr());
+  Record.AddDeclRef(E->getGuidDecl());
   if (E->isTypeOperand()) {
     Record.AddTypeSourceInfo(E->getTypeOperandSourceInfo());
     Code = serialization::EXPR_CXX_UUIDOF_TYPE;
@@ -2051,6 +2234,7 @@ void ASTStmtWriter::VisitOMPParallelDirective(OMPParallelDirective *D) {
   VisitStmt(D);
   Record.push_back(D->getNumClauses());
   VisitOMPExecutableDirective(D);
+  Record.AddStmt(D->getTaskReductionRefExpr());
   Record.push_back(D->hasCancel() ? 1 : 0);
   Code = serialization::STMT_OMP_PARALLEL_DIRECTIVE;
 }
@@ -2062,6 +2246,7 @@ void ASTStmtWriter::VisitOMPSimdDirective(OMPSimdDirective *D) {
 
 void ASTStmtWriter::VisitOMPForDirective(OMPForDirective *D) {
   VisitOMPLoopDirective(D);
+  Record.AddStmt(D->getTaskReductionRefExpr());
   Record.push_back(D->hasCancel() ? 1 : 0);
   Code = serialization::STMT_OMP_FOR_DIRECTIVE;
 }
@@ -2075,6 +2260,7 @@ void ASTStmtWriter::VisitOMPSectionsDirective(OMPSectionsDirective *D) {
   VisitStmt(D);
   Record.push_back(D->getNumClauses());
   VisitOMPExecutableDirective(D);
+  Record.AddStmt(D->getTaskReductionRefExpr());
   Record.push_back(D->hasCancel() ? 1 : 0);
   Code = serialization::STMT_OMP_SECTIONS_DIRECTIVE;
 }
@@ -2109,6 +2295,7 @@ void ASTStmtWriter::VisitOMPCriticalDirective(OMPCriticalDirective *D) {
 
 void ASTStmtWriter::VisitOMPParallelForDirective(OMPParallelForDirective *D) {
   VisitOMPLoopDirective(D);
+  Record.AddStmt(D->getTaskReductionRefExpr());
   Record.push_back(D->hasCancel() ? 1 : 0);
   Code = serialization::STMT_OMP_PARALLEL_FOR_DIRECTIVE;
 }
@@ -2124,6 +2311,7 @@ void ASTStmtWriter::VisitOMPParallelMasterDirective(
   VisitStmt(D);
   Record.push_back(D->getNumClauses());
   VisitOMPExecutableDirective(D);
+  Record.AddStmt(D->getTaskReductionRefExpr());
   Code = serialization::STMT_OMP_PARALLEL_MASTER_DIRECTIVE;
 }
 
@@ -2132,6 +2320,7 @@ void ASTStmtWriter::VisitOMPParallelSectionsDirective(
   VisitStmt(D);
   Record.push_back(D->getNumClauses());
   VisitOMPExecutableDirective(D);
+  Record.AddStmt(D->getTaskReductionRefExpr());
   Record.push_back(D->hasCancel() ? 1 : 0);
   Code = serialization::STMT_OMP_PARALLEL_SECTIONS_DIRECTIVE;
 }
@@ -2192,12 +2381,15 @@ void ASTStmtWriter::VisitOMPTargetParallelDirective(
   VisitStmt(D);
   Record.push_back(D->getNumClauses());
   VisitOMPExecutableDirective(D);
+  Record.AddStmt(D->getTaskReductionRefExpr());
+  Record.writeBool(D->hasCancel());
   Code = serialization::STMT_OMP_TARGET_PARALLEL_DIRECTIVE;
 }
 
 void ASTStmtWriter::VisitOMPTargetParallelForDirective(
     OMPTargetParallelForDirective *D) {
   VisitOMPLoopDirective(D);
+  Record.AddStmt(D->getTaskReductionRefExpr());
   Record.push_back(D->hasCancel() ? 1 : 0);
   Code = serialization::STMT_OMP_TARGET_PARALLEL_FOR_DIRECTIVE;
 }
@@ -2235,6 +2427,20 @@ void ASTStmtWriter::VisitOMPFlushDirective(OMPFlushDirective *D) {
   Code = serialization::STMT_OMP_FLUSH_DIRECTIVE;
 }
 
+void ASTStmtWriter::VisitOMPDepobjDirective(OMPDepobjDirective *D) {
+  VisitStmt(D);
+  Record.push_back(D->getNumClauses());
+  VisitOMPExecutableDirective(D);
+  Code = serialization::STMT_OMP_DEPOBJ_DIRECTIVE;
+}
+
+void ASTStmtWriter::VisitOMPScanDirective(OMPScanDirective *D) {
+  VisitStmt(D);
+  Record.push_back(D->getNumClauses());
+  VisitOMPExecutableDirective(D);
+  Code = serialization::STMT_OMP_SCAN_DIRECTIVE;
+}
+
 void ASTStmtWriter::VisitOMPOrderedDirective(OMPOrderedDirective *D) {
   VisitStmt(D);
   Record.push_back(D->getNumClauses());
@@ -2267,6 +2473,7 @@ void ASTStmtWriter::VisitOMPCancelDirective(OMPCancelDirective *D) {
 
 void ASTStmtWriter::VisitOMPTaskLoopDirective(OMPTaskLoopDirective *D) {
   VisitOMPLoopDirective(D);
+  Record.push_back(D->hasCancel() ? 1 : 0);
   Code = serialization::STMT_OMP_TASKLOOP_DIRECTIVE;
 }
 
@@ -2278,6 +2485,7 @@ void ASTStmtWriter::VisitOMPTaskLoopSimdDirective(OMPTaskLoopSimdDirective *D) {
 void ASTStmtWriter::VisitOMPMasterTaskLoopDirective(
     OMPMasterTaskLoopDirective *D) {
   VisitOMPLoopDirective(D);
+  Record.push_back(D->hasCancel() ? 1 : 0);
   Code = serialization::STMT_OMP_MASTER_TASKLOOP_DIRECTIVE;
 }
 
@@ -2290,6 +2498,7 @@ void ASTStmtWriter::VisitOMPMasterTaskLoopSimdDirective(
 void ASTStmtWriter::VisitOMPParallelMasterTaskLoopDirective(
     OMPParallelMasterTaskLoopDirective *D) {
   VisitOMPLoopDirective(D);
+  Record.push_back(D->hasCancel() ? 1 : 0);
   Code = serialization::STMT_OMP_PARALLEL_MASTER_TASKLOOP_DIRECTIVE;
 }
 
@@ -2314,6 +2523,7 @@ void ASTStmtWriter::VisitOMPTargetUpdateDirective(OMPTargetUpdateDirective *D) {
 void ASTStmtWriter::VisitOMPDistributeParallelForDirective(
     OMPDistributeParallelForDirective *D) {
   VisitOMPLoopDirective(D);
+  Record.AddStmt(D->getTaskReductionRefExpr());
   Record.push_back(D->hasCancel() ? 1 : 0);
   Code = serialization::STMT_OMP_DISTRIBUTE_PARALLEL_FOR_DIRECTIVE;
 }
@@ -2362,6 +2572,7 @@ void ASTStmtWriter::VisitOMPTeamsDistributeParallelForSimdDirective(
 void ASTStmtWriter::VisitOMPTeamsDistributeParallelForDirective(
     OMPTeamsDistributeParallelForDirective *D) {
   VisitOMPLoopDirective(D);
+  Record.AddStmt(D->getTaskReductionRefExpr());
   Record.push_back(D->hasCancel() ? 1 : 0);
   Code = serialization::STMT_OMP_TEAMS_DISTRIBUTE_PARALLEL_FOR_DIRECTIVE;
 }
@@ -2382,6 +2593,7 @@ void ASTStmtWriter::VisitOMPTargetTeamsDistributeDirective(
 void ASTStmtWriter::VisitOMPTargetTeamsDistributeParallelForDirective(
     OMPTargetTeamsDistributeParallelForDirective *D) {
   VisitOMPLoopDirective(D);
+  Record.AddStmt(D->getTaskReductionRefExpr());
   Record.push_back(D->hasCancel() ? 1 : 0);
   Code = serialization::STMT_OMP_TARGET_TEAMS_DISTRIBUTE_PARALLEL_FOR_DIRECTIVE;
 }
diff --git a/clang/lib/Serialization/GeneratePCH.cpp b/clang/lib/Serialization/GeneratePCH.cpp
index 002233e49bb0..d869796b82c1 100644
--- a/clang/lib/Serialization/GeneratePCH.cpp
+++ b/clang/lib/Serialization/GeneratePCH.cpp
@@ -57,6 +57,11 @@ void PCHGenerator::HandleTranslationUnit(ASTContext &Ctx) {
     }
   }
 
+  // Errors that do not prevent the PCH from being written should not cause the
+  // overall compilation to fail either.
+  if (AllowASTWithErrors)
+    PP.getDiagnostics().getClient()->clear();
+
   // Emit the PCH file to the Buffer.
   assert(SemaPtr && "No Sema?");
   Buffer->Signature =
diff --git a/clang/lib/Serialization/GlobalModuleIndex.cpp b/clang/lib/Serialization/GlobalModuleIndex.cpp
index 462d29c2a0f1..9192b3b476bb 100644
--- a/clang/lib/Serialization/GlobalModuleIndex.cpp
+++ b/clang/lib/Serialization/GlobalModuleIndex.cpp
@@ -321,7 +321,7 @@ bool GlobalModuleIndex::lookupIdentifier(StringRef Name, HitSet &Hits) {
     = *static_cast<IdentifierIndexTable *>(IdentifierIndex);
   IdentifierIndexTable::iterator Known = Table.find(Name);
   if (Known == Table.end()) {
-    return true;
+    return false;
   }
 
   SmallVector<unsigned, 2> ModuleIDs = *Known;
@@ -643,10 +643,10 @@ llvm::Error GlobalModuleIndexBuilder::loadModuleFile(const FileEntry *File) {
 
         // Skip the stored signature.
         // FIXME: we could read the signature out of the import and validate it.
-        ASTFileSignature StoredSignature = {
-            {{(uint32_t)Record[Idx++], (uint32_t)Record[Idx++],
-              (uint32_t)Record[Idx++], (uint32_t)Record[Idx++],
-              (uint32_t)Record[Idx++]}}};
+        auto FirstSignatureByte = Record.begin() + Idx;
+        ASTFileSignature StoredSignature = ASTFileSignature::create(
+            FirstSignatureByte, FirstSignatureByte + ASTFileSignature::size);
+        Idx += ASTFileSignature::size;
 
         // Skip the module name (currently this is only used for prebuilt
         // modules while here we are only dealing with cached).
@@ -704,9 +704,8 @@ llvm::Error GlobalModuleIndexBuilder::loadModuleFile(const FileEntry *File) {
 
     // Get Signature.
     if (State == DiagnosticOptionsBlock && Code == SIGNATURE)
-      getModuleFileInfo(File).Signature = {
-          {{(uint32_t)Record[0], (uint32_t)Record[1], (uint32_t)Record[2],
-            (uint32_t)Record[3], (uint32_t)Record[4]}}};
+      getModuleFileInfo(File).Signature = ASTFileSignature::create(
+          Record.begin(), Record.begin() + ASTFileSignature::size);
 
     // We don't care about this record.
   }
diff --git a/clang/lib/Serialization/ModuleManager.cpp b/clang/lib/Serialization/ModuleManager.cpp
index daef502cdcb5..a42ed2f3c179 100644
--- a/clang/lib/Serialization/ModuleManager.cpp
+++ b/clang/lib/Serialization/ModuleManager.cpp
@@ -185,7 +185,14 @@ ModuleManager::addModule(StringRef FileName, ModuleKind Type,
       Buf = llvm::MemoryBuffer::getSTDIN();
     } else {
       // Get a buffer of the file and close the file descriptor when done.
-      Buf = FileMgr.getBufferForFile(NewModule->File, /*isVolatile=*/false);
+      // The file is volatile because in a parallel build we expect multiple
+      // compiler processes to use the same module file rebuilding it if needed.
+      //
+      // RequiresNullTerminator is false because module files don't need it, and
+      // this allows the file to still be mmapped.
+      Buf = FileMgr.getBufferForFile(NewModule->File,
+                                     /*IsVolatile=*/true,
+                                     /*RequiresNullTerminator=*/false);
     }
 
     if (!Buf) {
@@ -439,7 +446,7 @@ bool ModuleManager::lookupModuleFile(StringRef FileName,
 
   // Open the file immediately to ensure there is no race between stat'ing and
   // opening the file.
-  auto FileOrErr = FileMgr.getFile(FileName, /*OpenFile=*/true, 
+  auto FileOrErr = FileMgr.getFile(FileName, /*OpenFile=*/true,
                                    /*CacheFailure=*/false);
   if (!FileOrErr) {
     File = nullptr;