diff --git a/clang/include/clang/AST/Decl.h b/clang/include/clang/AST/Decl.h
@@ -1731,7 +1731,7 @@ class ImplicitParamDecl : public VarDecl {
   static ImplicitParamDecl *CreateDeserialized(ASTContext &C, unsigned ID);
 
   ImplicitParamDecl(ASTContext &C, DeclContext *DC, SourceLocation IdLoc,
-                    IdentifierInfo *Id, QualType Type,
+                    const IdentifierInfo *Id, QualType Type,
                     ImplicitParamKind ParamKind)
       : VarDecl(ImplicitParam, C, DC, IdLoc, IdLoc, Id, Type,
                 /*TInfo=*/nullptr, SC_None) {
@@ -1765,7 +1765,7 @@ class ParmVarDecl : public VarDecl {
 
 protected:
   ParmVarDecl(Kind DK, ASTContext &C, DeclContext *DC, SourceLocation StartLoc,
-              SourceLocation IdLoc, IdentifierInfo *Id, QualType T,
+              SourceLocation IdLoc, const IdentifierInfo *Id, QualType T,
               TypeSourceInfo *TInfo, StorageClass S, Expr *DefArg)
       : VarDecl(DK, C, DC, StartLoc, IdLoc, Id, T, TInfo, S) {
     assert(ParmVarDeclBits.HasInheritedDefaultArg == false);
@@ -1777,10 +1777,10 @@ class ParmVarDecl : public VarDecl {
 
 public:
   static ParmVarDecl *Create(ASTContext &C, DeclContext *DC,
-                             SourceLocation StartLoc,
-                             SourceLocation IdLoc, IdentifierInfo *Id,
-                             QualType T, TypeSourceInfo *TInfo,
-                             StorageClass S, Expr *DefArg);
+                             SourceLocation StartLoc, SourceLocation IdLoc,
+                             const IdentifierInfo *Id, QualType T,
+                             TypeSourceInfo *TInfo, StorageClass S,
+                             Expr *DefArg);
 
   static ParmVarDecl *CreateDeserialized(ASTContext &C, unsigned ID);
 
@@ -3095,7 +3095,7 @@ class FieldDecl : public DeclaratorDecl, public Mergeable<FieldDecl> {
 
 protected:
   FieldDecl(Kind DK, DeclContext *DC, SourceLocation StartLoc,
-            SourceLocation IdLoc, IdentifierInfo *Id, QualType T,
+            SourceLocation IdLoc, const IdentifierInfo *Id, QualType T,
             TypeSourceInfo *TInfo, Expr *BW, bool Mutable,
             InClassInitStyle InitStyle)
       : DeclaratorDecl(DK, DC, IdLoc, Id, T, TInfo, StartLoc), BitField(false),
@@ -3111,7 +3111,7 @@ class FieldDecl : public DeclaratorDecl, public Mergeable<FieldDecl> {
 
   static FieldDecl *Create(const ASTContext &C, DeclContext *DC,
                            SourceLocation StartLoc, SourceLocation IdLoc,
-                           IdentifierInfo *Id, QualType T,
+                           const IdentifierInfo *Id, QualType T,
                            TypeSourceInfo *TInfo, Expr *BW, bool Mutable,
                            InClassInitStyle InitStyle);
 
@@ -3332,8 +3332,9 @@ class IndirectFieldDecl : public ValueDecl,
   friend class ASTDeclReader;
 
   static IndirectFieldDecl *Create(ASTContext &C, DeclContext *DC,
-                                   SourceLocation L, IdentifierInfo *Id,
-                                   QualType T, llvm::MutableArrayRef<NamedDecl *> CH);
+                                   SourceLocation L, const IdentifierInfo *Id,
+                                   QualType T,
+                                   llvm::MutableArrayRef<NamedDecl *> CH);
 
   static IndirectFieldDecl *CreateDeserialized(ASTContext &C, unsigned ID);
 
@@ -3381,9 +3382,9 @@ class TypeDecl : public NamedDecl {
   void anchor() override;
 
 protected:
-  TypeDecl(Kind DK, DeclContext *DC, SourceLocation L, IdentifierInfo *Id,
+  TypeDecl(Kind DK, DeclContext *DC, SourceLocation L, const IdentifierInfo *Id,
            SourceLocation StartL = SourceLocation())
-    : NamedDecl(DK, DC, L, Id), LocStart(StartL) {}
+      : NamedDecl(DK, DC, L, Id), LocStart(StartL) {}
 
 public:
   // Low-level accessor. If you just want the type defined by this node,
@@ -3425,7 +3426,7 @@ class TypedefNameDecl : public TypeDecl, public Redeclarable<TypedefNameDecl> {
 protected:
   TypedefNameDecl(Kind DK, ASTContext &C, DeclContext *DC,
                   SourceLocation StartLoc, SourceLocation IdLoc,
-                  IdentifierInfo *Id, TypeSourceInfo *TInfo)
+                  const IdentifierInfo *Id, TypeSourceInfo *TInfo)
       : TypeDecl(DK, DC, IdLoc, Id, StartLoc), redeclarable_base(C),
         MaybeModedTInfo(TInfo, 0) {}
 
@@ -3512,13 +3513,14 @@ class TypedefNameDecl : public TypeDecl, public Redeclarable<TypedefNameDecl> {
 /// type specifier.
 class TypedefDecl : public TypedefNameDecl {
   TypedefDecl(ASTContext &C, DeclContext *DC, SourceLocation StartLoc,
-              SourceLocation IdLoc, IdentifierInfo *Id, TypeSourceInfo *TInfo)
+              SourceLocation IdLoc, const IdentifierInfo *Id,
+              TypeSourceInfo *TInfo)
       : TypedefNameDecl(Typedef, C, DC, StartLoc, IdLoc, Id, TInfo) {}
 
 public:
   static TypedefDecl *Create(ASTContext &C, DeclContext *DC,
                              SourceLocation StartLoc, SourceLocation IdLoc,
-                             IdentifierInfo *Id, TypeSourceInfo *TInfo);
+                             const IdentifierInfo *Id, TypeSourceInfo *TInfo);
   static TypedefDecl *CreateDeserialized(ASTContext &C, unsigned ID);
 
   SourceRange getSourceRange() const override LLVM_READONLY;
@@ -3535,14 +3537,15 @@ class TypeAliasDecl : public TypedefNameDecl {
   TypeAliasTemplateDecl *Template;
 
   TypeAliasDecl(ASTContext &C, DeclContext *DC, SourceLocation StartLoc,
-                SourceLocation IdLoc, IdentifierInfo *Id, TypeSourceInfo *TInfo)
+                SourceLocation IdLoc, const IdentifierInfo *Id,
+                TypeSourceInfo *TInfo)
       : TypedefNameDecl(TypeAlias, C, DC, StartLoc, IdLoc, Id, TInfo),
         Template(nullptr) {}
 
 public:
   static TypeAliasDecl *Create(ASTContext &C, DeclContext *DC,
                                SourceLocation StartLoc, SourceLocation IdLoc,
-                               IdentifierInfo *Id, TypeSourceInfo *TInfo);
+                               const IdentifierInfo *Id, TypeSourceInfo *TInfo);
   static TypeAliasDecl *CreateDeserialized(ASTContext &C, unsigned ID);
 
   SourceRange getSourceRange() const override LLVM_READONLY;

diff --git a/clang/include/clang/AST/DeclObjC.h b/clang/include/clang/AST/DeclObjC.h
@@ -772,7 +772,7 @@ class ObjCPropertyDecl : public NamedDecl {
   // Synthesize ivar for this property
   ObjCIvarDecl *PropertyIvarDecl = nullptr;
 
-  ObjCPropertyDecl(DeclContext *DC, SourceLocation L, IdentifierInfo *Id,
+  ObjCPropertyDecl(DeclContext *DC, SourceLocation L, const IdentifierInfo *Id,
                    SourceLocation AtLocation, SourceLocation LParenLocation,
                    QualType T, TypeSourceInfo *TSI, PropertyControl propControl)
       : NamedDecl(ObjCProperty, DC, L, Id), AtLoc(AtLocation),
@@ -782,10 +782,12 @@ class ObjCPropertyDecl : public NamedDecl {
         PropertyImplementation(propControl) {}
 
 public:
-  static ObjCPropertyDecl *
-  Create(ASTContext &C, DeclContext *DC, SourceLocation L, IdentifierInfo *Id,
-         SourceLocation AtLocation, SourceLocation LParenLocation, QualType T,
-         TypeSourceInfo *TSI, PropertyControl propControl = None);
+  static ObjCPropertyDecl *Create(ASTContext &C, DeclContext *DC,
+                                  SourceLocation L, const IdentifierInfo *Id,
+                                  SourceLocation AtLocation,
+                                  SourceLocation LParenLocation, QualType T,
+                                  TypeSourceInfo *TSI,
+                                  PropertyControl propControl = None);
 
   static ObjCPropertyDecl *CreateDeserialized(ASTContext &C, unsigned ID);
 
@@ -952,7 +954,7 @@ class ObjCContainerDecl : public NamedDecl, public DeclContext {
   void anchor() override;
 
 public:
-  ObjCContainerDecl(Kind DK, DeclContext *DC, IdentifierInfo *Id,
+  ObjCContainerDecl(Kind DK, DeclContext *DC, const IdentifierInfo *Id,
                     SourceLocation nameLoc, SourceLocation atStartLoc);
 
   // Iterator access to instance/class properties.
@@ -1240,7 +1242,7 @@ class ObjCInterfaceDecl : public ObjCContainerDecl
   llvm::PointerIntPair<DefinitionData *, 1, bool> Data;
 
   ObjCInterfaceDecl(const ASTContext &C, DeclContext *DC, SourceLocation AtLoc,
-                    IdentifierInfo *Id, ObjCTypeParamList *typeParamList,
+                    const IdentifierInfo *Id, ObjCTypeParamList *typeParamList,
                     SourceLocation CLoc, ObjCInterfaceDecl *PrevDecl,
                     bool IsInternal);
 
@@ -1271,13 +1273,11 @@ class ObjCInterfaceDecl : public ObjCContainerDecl
   }
 
 public:
-  static ObjCInterfaceDecl *Create(const ASTContext &C, DeclContext *DC,
-                                   SourceLocation atLoc,
-                                   IdentifierInfo *Id,
-                                   ObjCTypeParamList *typeParamList,
-                                   ObjCInterfaceDecl *PrevDecl,
-                                   SourceLocation ClassLoc = SourceLocation(),
-                                   bool isInternal = false);
+  static ObjCInterfaceDecl *
+  Create(const ASTContext &C, DeclContext *DC, SourceLocation atLoc,
+         const IdentifierInfo *Id, ObjCTypeParamList *typeParamList,
+         ObjCInterfaceDecl *PrevDecl,
+         SourceLocation ClassLoc = SourceLocation(), bool isInternal = false);
 
   static ObjCInterfaceDecl *CreateDeserialized(const ASTContext &C, unsigned ID);
 
@@ -1338,7 +1338,8 @@ class ObjCInterfaceDecl : public ObjCContainerDecl
   ObjCImplementationDecl *getImplementation() const;
   void setImplementation(ObjCImplementationDecl *ImplD);
 
-  ObjCCategoryDecl *FindCategoryDeclaration(IdentifierInfo *CategoryId) const;
+  ObjCCategoryDecl *
+  FindCategoryDeclaration(const IdentifierInfo *CategoryId) const;
 
   // Get the local instance/class method declared in a category.
   ObjCMethodDecl *getCategoryInstanceMethod(Selector Sel) const;
@@ -1794,9 +1795,9 @@ class ObjCInterfaceDecl : public ObjCContainerDecl
     data().CategoryList = category;
   }
 
-  ObjCPropertyDecl
-    *FindPropertyVisibleInPrimaryClass(IdentifierInfo *PropertyId,
-                                       ObjCPropertyQueryKind QueryKind) const;
+  ObjCPropertyDecl *
+  FindPropertyVisibleInPrimaryClass(const IdentifierInfo *PropertyId,
+                                    ObjCPropertyQueryKind QueryKind) const;
 
   void collectPropertiesToImplement(PropertyMap &PM) const override;
 
@@ -1954,8 +1955,8 @@ class ObjCIvarDecl : public FieldDecl {
 
 private:
   ObjCIvarDecl(ObjCContainerDecl *DC, SourceLocation StartLoc,
-               SourceLocation IdLoc, IdentifierInfo *Id,
-               QualType T, TypeSourceInfo *TInfo, AccessControl ac, Expr *BW,
+               SourceLocation IdLoc, const IdentifierInfo *Id, QualType T,
+               TypeSourceInfo *TInfo, AccessControl ac, Expr *BW,
                bool synthesized)
       : FieldDecl(ObjCIvar, DC, StartLoc, IdLoc, Id, T, TInfo, BW,
                   /*Mutable=*/false, /*HasInit=*/ICIS_NoInit),
@@ -1964,10 +1965,9 @@ class ObjCIvarDecl : public FieldDecl {
 public:
   static ObjCIvarDecl *Create(ASTContext &C, ObjCContainerDecl *DC,
                               SourceLocation StartLoc, SourceLocation IdLoc,
-                              IdentifierInfo *Id, QualType T,
-                              TypeSourceInfo *TInfo,
-                              AccessControl ac, Expr *BW = nullptr,
-                              bool synthesized=false);
+                              const IdentifierInfo *Id, QualType T,
+                              TypeSourceInfo *TInfo, AccessControl ac,
+                              Expr *BW = nullptr, bool synthesized = false);
 
   static ObjCIvarDecl *CreateDeserialized(ASTContext &C, unsigned ID);
 
@@ -2343,7 +2343,7 @@ class ObjCCategoryDecl : public ObjCContainerDecl {
 
   ObjCCategoryDecl(DeclContext *DC, SourceLocation AtLoc,
                    SourceLocation ClassNameLoc, SourceLocation CategoryNameLoc,
-                   IdentifierInfo *Id, ObjCInterfaceDecl *IDecl,
+                   const IdentifierInfo *Id, ObjCInterfaceDecl *IDecl,
                    ObjCTypeParamList *typeParamList,
                    SourceLocation IvarLBraceLoc = SourceLocation(),
                    SourceLocation IvarRBraceLoc = SourceLocation());
@@ -2354,15 +2354,13 @@ class ObjCCategoryDecl : public ObjCContainerDecl {
   friend class ASTDeclReader;
   friend class ASTDeclWriter;
 
-  static ObjCCategoryDecl *Create(ASTContext &C, DeclContext *DC,
-                                  SourceLocation AtLoc,
-                                  SourceLocation ClassNameLoc,
-                                  SourceLocation CategoryNameLoc,
-                                  IdentifierInfo *Id,
-                                  ObjCInterfaceDecl *IDecl,
-                                  ObjCTypeParamList *typeParamList,
-                                  SourceLocation IvarLBraceLoc=SourceLocation(),
-                                  SourceLocation IvarRBraceLoc=SourceLocation());
+  static ObjCCategoryDecl *
+  Create(ASTContext &C, DeclContext *DC, SourceLocation AtLoc,
+         SourceLocation ClassNameLoc, SourceLocation CategoryNameLoc,
+         const IdentifierInfo *Id, ObjCInterfaceDecl *IDecl,
+         ObjCTypeParamList *typeParamList,
+         SourceLocation IvarLBraceLoc = SourceLocation(),
+         SourceLocation IvarRBraceLoc = SourceLocation());
   static ObjCCategoryDecl *CreateDeserialized(ASTContext &C, unsigned ID);
 
   ObjCInterfaceDecl *getClassInterface() { return ClassInterface; }
@@ -2472,10 +2470,9 @@ class ObjCImplDecl : public ObjCContainerDecl {
   void anchor() override;
 
 protected:
-  ObjCImplDecl(Kind DK, DeclContext *DC,
-               ObjCInterfaceDecl *classInterface,
-               IdentifierInfo *Id,
-               SourceLocation nameLoc, SourceLocation atStartLoc)
+  ObjCImplDecl(Kind DK, DeclContext *DC, ObjCInterfaceDecl *classInterface,
+               const IdentifierInfo *Id, SourceLocation nameLoc,
+               SourceLocation atStartLoc)
       : ObjCContainerDecl(DK, DC, Id, nameLoc, atStartLoc),
         ClassInterface(classInterface) {}
 
@@ -2543,12 +2540,12 @@ class ObjCCategoryImplDecl : public ObjCImplDecl {
   // Category name location
   SourceLocation CategoryNameLoc;
 
-  ObjCCategoryImplDecl(DeclContext *DC, IdentifierInfo *Id,
+  ObjCCategoryImplDecl(DeclContext *DC, const IdentifierInfo *Id,
                        ObjCInterfaceDecl *classInterface,
                        SourceLocation nameLoc, SourceLocation atStartLoc,
                        SourceLocation CategoryNameLoc)
-      : ObjCImplDecl(ObjCCategoryImpl, DC, classInterface, Id,
-                     nameLoc, atStartLoc),
+      : ObjCImplDecl(ObjCCategoryImpl, DC, classInterface, Id, nameLoc,
+                     atStartLoc),
         CategoryNameLoc(CategoryNameLoc) {}
 
   void anchor() override;
@@ -2557,12 +2554,10 @@ class ObjCCategoryImplDecl : public ObjCImplDecl {
   friend class ASTDeclReader;
   friend class ASTDeclWriter;
 
-  static ObjCCategoryImplDecl *Create(ASTContext &C, DeclContext *DC,
-                                      IdentifierInfo *Id,
-                                      ObjCInterfaceDecl *classInterface,
-                                      SourceLocation nameLoc,
-                                      SourceLocation atStartLoc,
-                                      SourceLocation CategoryNameLoc);
+  static ObjCCategoryImplDecl *
+  Create(ASTContext &C, DeclContext *DC, const IdentifierInfo *Id,
+         ObjCInterfaceDecl *classInterface, SourceLocation nameLoc,
+         SourceLocation atStartLoc, SourceLocation CategoryNameLoc);
   static ObjCCategoryImplDecl *CreateDeserialized(ASTContext &C, unsigned ID);
 
   ObjCCategoryDecl *getCategoryDecl() const;

diff --git a/clang/include/clang/AST/DeclTemplate.h b/clang/include/clang/AST/DeclTemplate.h
@@ -1389,27 +1389,27 @@ class NonTypeTemplateParmDecl final
 
   NonTypeTemplateParmDecl(DeclContext *DC, SourceLocation StartLoc,
                           SourceLocation IdLoc, unsigned D, unsigned P,
-                          IdentifierInfo *Id, QualType T,
+                          const IdentifierInfo *Id, QualType T,
                           bool ParameterPack, TypeSourceInfo *TInfo)
       : DeclaratorDecl(NonTypeTemplateParm, DC, IdLoc, Id, T, TInfo, StartLoc),
         TemplateParmPosition(D, P), ParameterPack(ParameterPack) {}
 
   NonTypeTemplateParmDecl(DeclContext *DC, SourceLocation StartLoc,
                           SourceLocation IdLoc, unsigned D, unsigned P,
-                          IdentifierInfo *Id, QualType T,
+                          const IdentifierInfo *Id, QualType T,
                           TypeSourceInfo *TInfo,
                           ArrayRef<QualType> ExpandedTypes,
                           ArrayRef<TypeSourceInfo *> ExpandedTInfos);
 
 public:
   static NonTypeTemplateParmDecl *
   Create(const ASTContext &C, DeclContext *DC, SourceLocation StartLoc,
-         SourceLocation IdLoc, unsigned D, unsigned P, IdentifierInfo *Id,
+         SourceLocation IdLoc, unsigned D, unsigned P, const IdentifierInfo *Id,
          QualType T, bool ParameterPack, TypeSourceInfo *TInfo);
 
   static NonTypeTemplateParmDecl *
   Create(const ASTContext &C, DeclContext *DC, SourceLocation StartLoc,
-         SourceLocation IdLoc, unsigned D, unsigned P, IdentifierInfo *Id,
+         SourceLocation IdLoc, unsigned D, unsigned P, const IdentifierInfo *Id,
          QualType T, TypeSourceInfo *TInfo, ArrayRef<QualType> ExpandedTypes,
          ArrayRef<TypeSourceInfo *> ExpandedTInfos);
 

diff --git a/clang/include/clang/AST/ExprCXX.h b/clang/include/clang/AST/ExprCXX.h
@@ -1149,6 +1149,7 @@ class CXXThisExpr : public Expr {
   CXXThisExpr(SourceLocation L, QualType Ty, bool IsImplicit, ExprValueKind VK)
       : Expr(CXXThisExprClass, Ty, VK, OK_Ordinary) {
     CXXThisExprBits.IsImplicit = IsImplicit;
+    CXXThisExprBits.CapturedByCopyInLambdaWithExplicitObjectParameter = false;
     CXXThisExprBits.Loc = L;
     setDependence(computeDependence(this));
   }
@@ -1170,6 +1171,15 @@ class CXXThisExpr : public Expr {
   bool isImplicit() const { return CXXThisExprBits.IsImplicit; }
   void setImplicit(bool I) { CXXThisExprBits.IsImplicit = I; }
 
+  bool isCapturedByCopyInLambdaWithExplicitObjectParameter() const {
+    return CXXThisExprBits.CapturedByCopyInLambdaWithExplicitObjectParameter;
+  }
+
+  void setCapturedByCopyInLambdaWithExplicitObjectParameter(bool Set) {
+    CXXThisExprBits.CapturedByCopyInLambdaWithExplicitObjectParameter = Set;
+    setDependence(computeDependence(this));
+  }
+
   static bool classof(const Stmt *T) {
     return T->getStmtClass() == CXXThisExprClass;
   }
@@ -2549,15 +2559,15 @@ class CXXDeleteExpr : public Expr {
 class PseudoDestructorTypeStorage {
   /// Either the type source information or the name of the type, if
   /// it couldn't be resolved due to type-dependence.
-  llvm::PointerUnion<TypeSourceInfo *, IdentifierInfo *> Type;
+  llvm::PointerUnion<TypeSourceInfo *, const IdentifierInfo *> Type;
 
   /// The starting source location of the pseudo-destructor type.
   SourceLocation Location;
 
 public:
   PseudoDestructorTypeStorage() = default;
 
-  PseudoDestructorTypeStorage(IdentifierInfo *II, SourceLocation Loc)
+  PseudoDestructorTypeStorage(const IdentifierInfo *II, SourceLocation Loc)
       : Type(II), Location(Loc) {}
 
   PseudoDestructorTypeStorage(TypeSourceInfo *Info);
@@ -2566,8 +2576,8 @@ class PseudoDestructorTypeStorage {
     return Type.dyn_cast<TypeSourceInfo *>();
   }
 
-  IdentifierInfo *getIdentifier() const {
-    return Type.dyn_cast<IdentifierInfo *>();
+  const IdentifierInfo *getIdentifier() const {
+    return Type.dyn_cast<const IdentifierInfo *>();
   }
 
   SourceLocation getLocation() const { return Location; }
@@ -2698,7 +2708,7 @@ class CXXPseudoDestructorExpr : public Expr {
   /// In a dependent pseudo-destructor expression for which we do not
   /// have full type information on the destroyed type, provides the name
   /// of the destroyed type.
-  IdentifierInfo *getDestroyedTypeIdentifier() const {
+  const IdentifierInfo *getDestroyedTypeIdentifier() const {
     return DestroyedType.getIdentifier();
   }
 

diff --git a/clang/include/clang/AST/ExternalASTSource.h b/clang/include/clang/AST/ExternalASTSource.h
@@ -138,7 +138,7 @@ class ExternalASTSource : public RefCountedBase<ExternalASTSource> {
   virtual CXXBaseSpecifier *GetExternalCXXBaseSpecifiers(uint64_t Offset);
 
   /// Update an out-of-date identifier.
-  virtual void updateOutOfDateIdentifier(IdentifierInfo &II) {}
+  virtual void updateOutOfDateIdentifier(const IdentifierInfo &II) {}
 
   /// Find all declarations with the given name in the given context,
   /// and add them to the context by calling SetExternalVisibleDeclsForName

diff --git a/clang/include/clang/AST/NestedNameSpecifier.h b/clang/include/clang/AST/NestedNameSpecifier.h
@@ -124,7 +124,7 @@ class NestedNameSpecifier : public llvm::FoldingSetNode {
   /// cannot be resolved.
   static NestedNameSpecifier *Create(const ASTContext &Context,
                                      NestedNameSpecifier *Prefix,
-                                     IdentifierInfo *II);
+                                     const IdentifierInfo *II);
 
   /// Builds a nested name specifier that names a namespace.
   static NestedNameSpecifier *Create(const ASTContext &Context,
@@ -134,7 +134,7 @@ class NestedNameSpecifier : public llvm::FoldingSetNode {
   /// Builds a nested name specifier that names a namespace alias.
   static NestedNameSpecifier *Create(const ASTContext &Context,
                                      NestedNameSpecifier *Prefix,
-                                     NamespaceAliasDecl *Alias);
+                                     const NamespaceAliasDecl *Alias);
 
   /// Builds a nested name specifier that names a type.
   static NestedNameSpecifier *Create(const ASTContext &Context,
@@ -148,7 +148,7 @@ class NestedNameSpecifier : public llvm::FoldingSetNode {
   /// nested name specifier, e.g., in "x->Base::f", the "x" has a dependent
   /// type.
   static NestedNameSpecifier *Create(const ASTContext &Context,
-                                     IdentifierInfo *II);
+                                     const IdentifierInfo *II);
 
   /// Returns the nested name specifier representing the global
   /// scope.

diff --git a/clang/include/clang/AST/OpenACCClause.h b/clang/include/clang/AST/OpenACCClause.h
@@ -51,6 +51,36 @@ class OpenACCClauseWithParams : public OpenACCClause {
   SourceLocation getLParenLoc() const { return LParenLoc; }
 };
 
+/// A 'default' clause, has the optional 'none' or 'present' argument.
+class OpenACCDefaultClause : public OpenACCClauseWithParams {
+  friend class ASTReaderStmt;
+  friend class ASTWriterStmt;
+
+  OpenACCDefaultClauseKind DefaultClauseKind;
+
+protected:
+  OpenACCDefaultClause(OpenACCDefaultClauseKind K, SourceLocation BeginLoc,
+                       SourceLocation LParenLoc, SourceLocation EndLoc)
+      : OpenACCClauseWithParams(OpenACCClauseKind::Default, BeginLoc, LParenLoc,
+                                EndLoc),
+        DefaultClauseKind(K) {
+    assert((DefaultClauseKind == OpenACCDefaultClauseKind::None ||
+            DefaultClauseKind == OpenACCDefaultClauseKind::Present) &&
+           "Invalid Clause Kind");
+  }
+
+public:
+  OpenACCDefaultClauseKind getDefaultClauseKind() const {
+    return DefaultClauseKind;
+  }
+
+  static OpenACCDefaultClause *Create(const ASTContext &C,
+                                      OpenACCDefaultClauseKind K,
+                                      SourceLocation BeginLoc,
+                                      SourceLocation LParenLoc,
+                                      SourceLocation EndLoc);
+};
+
 template <class Impl> class OpenACCClauseVisitor {
   Impl &getDerived() { return static_cast<Impl &>(*this); }
 
@@ -66,6 +96,8 @@ template <class Impl> class OpenACCClauseVisitor {
 
     switch (C->getClauseKind()) {
     case OpenACCClauseKind::Default:
+      VisitOpenACCDefaultClause(*cast<OpenACCDefaultClause>(C));
+      return;
     case OpenACCClauseKind::Finalize:
     case OpenACCClauseKind::IfPresent:
     case OpenACCClauseKind::Seq:
@@ -112,6 +144,10 @@ template <class Impl> class OpenACCClauseVisitor {
     }
     llvm_unreachable("Invalid Clause kind");
   }
+
+  void VisitOpenACCDefaultClause(const OpenACCDefaultClause &Clause) {
+    return getDerived().VisitOpenACCDefaultClause(Clause);
+  }
 };
 
 class OpenACCClausePrinter final
@@ -128,6 +164,8 @@ class OpenACCClausePrinter final
     }
   }
   OpenACCClausePrinter(raw_ostream &OS) : OS(OS) {}
+
+  void VisitOpenACCDefaultClause(const OpenACCDefaultClause &Clause);
 };
 
 } // namespace clang

diff --git a/clang/include/clang/AST/Stmt.h b/clang/include/clang/AST/Stmt.h
@@ -784,6 +784,11 @@ class alignas(void *) Stmt {
     LLVM_PREFERRED_TYPE(bool)
     unsigned IsImplicit : 1;
 
+    /// Whether there is a lambda with an explicit object parameter that
+    /// captures this "this" by copy.
+    LLVM_PREFERRED_TYPE(bool)
+    unsigned CapturedByCopyInLambdaWithExplicitObjectParameter : 1;
+
     /// The location of the "this".
     SourceLocation Loc;
   };

diff --git a/clang/include/clang/AST/StmtOpenMP.h b/clang/include/clang/AST/StmtOpenMP.h
@@ -6109,6 +6109,8 @@ class OMPTeamsGenericLoopDirective final : public OMPLoopDirective {
 class OMPTargetTeamsGenericLoopDirective final : public OMPLoopDirective {
   friend class ASTStmtReader;
   friend class OMPExecutableDirective;
+  /// true if loop directive's associated loop can be a parallel for.
+  bool CanBeParallelFor = false;
   /// Build directive with the given start and end location.
   ///
   /// \param StartLoc Starting location of the directive kind.
@@ -6131,6 +6133,9 @@ class OMPTargetTeamsGenericLoopDirective final : public OMPLoopDirective {
                          llvm::omp::OMPD_target_teams_loop, SourceLocation(),
                          SourceLocation(), CollapsedNum) {}
 
+  /// Set whether associated loop can be a parallel for.
+  void setCanBeParallelFor(bool ParFor) { CanBeParallelFor = ParFor; }
+
 public:
   /// Creates directive with a list of \p Clauses.
   ///
@@ -6145,7 +6150,7 @@ class OMPTargetTeamsGenericLoopDirective final : public OMPLoopDirective {
   static OMPTargetTeamsGenericLoopDirective *
   Create(const ASTContext &C, SourceLocation StartLoc, SourceLocation EndLoc,
          unsigned CollapsedNum, ArrayRef<OMPClause *> Clauses,
-         Stmt *AssociatedStmt, const HelperExprs &Exprs);
+         Stmt *AssociatedStmt, const HelperExprs &Exprs, bool CanBeParallelFor);
 
   /// Creates an empty directive with the place
   /// for \a NumClauses clauses.
@@ -6159,6 +6164,10 @@ class OMPTargetTeamsGenericLoopDirective final : public OMPLoopDirective {
                                                          unsigned CollapsedNum,
                                                          EmptyShell);
 
+  /// Return true if current loop directive's associated loop can be a
+  /// parallel for.
+  bool canBeParallelFor() const { return CanBeParallelFor; }
+
   static bool classof(const Stmt *T) {
     return T->getStmtClass() == OMPTargetTeamsGenericLoopDirectiveClass;
   }

diff --git a/clang/include/clang/ASTMatchers/ASTMatchers.h b/clang/include/clang/ASTMatchers/ASTMatchers.h
@@ -4961,6 +4961,8 @@ AST_MATCHER_P(LambdaExpr, hasAnyCapture, internal::Matcher<LambdaCapture>,
 /// capturesVar(hasName("x")) matches `x` and `x = 1`.
 AST_MATCHER_P(LambdaCapture, capturesVar, internal::Matcher<ValueDecl>,
               InnerMatcher) {
+  if (!Node.capturesVariable())
+    return false;
   auto *capturedVar = Node.getCapturedVar();
   return capturedVar && InnerMatcher.matches(*capturedVar, Finder, Builder);
 }

diff --git a/clang/include/clang/Analysis/SelectorExtras.h b/clang/include/clang/Analysis/SelectorExtras.h
@@ -15,10 +15,10 @@ namespace clang {
 
 template <typename... IdentifierInfos>
 static inline Selector getKeywordSelector(ASTContext &Ctx,
-                                          IdentifierInfos *... IIs) {
+                                          const IdentifierInfos *...IIs) {
   static_assert(sizeof...(IdentifierInfos) > 0,
                 "keyword selectors must have at least one argument");
-  SmallVector<IdentifierInfo *, 10> II({&Ctx.Idents.get(IIs)...});
+  SmallVector<const IdentifierInfo *, 10> II({&Ctx.Idents.get(IIs)...});
 
   return Ctx.Selectors.getSelector(II.size(), &II[0]);
 }

diff --git a/clang/include/clang/Basic/Attr.td b/clang/include/clang/Basic/Attr.td
@@ -324,13 +324,10 @@ class Spelling<string name, string variety, int version = 1> {
 }
 
 class GNU<string name> : Spelling<name, "GNU">;
-class Declspec<string name> : Spelling<name, "Declspec"> {
-  bit PrintOnLeft = 1;
-}
+class Declspec<string name> : Spelling<name, "Declspec">;
 class Microsoft<string name> : Spelling<name, "Microsoft">;
 class CXX11<string namespace, string name, int version = 1>
     : Spelling<name, "CXX11", version> {
-  bit CanPrintOnLeft = 0;
   string Namespace = namespace;
 }
 class C23<string namespace, string name, int version = 1>
@@ -596,12 +593,6 @@ class AttrSubjectMatcherAggregateRule<AttrSubject subject> {
 def SubjectMatcherForNamed : AttrSubjectMatcherAggregateRule<Named>;
 
 class Attr {
-  // Specifies that when printed, this attribute is meaningful on the
-  // 'left side' of the declaration.
-  bit CanPrintOnLeft = 1;
-  // Specifies that when printed, this attribute is required to be printed on
-  // the 'left side' of the declaration.
-  bit PrintOnLeft = 0;
   // The various ways in which an attribute can be spelled in source
   list<Spelling> Spellings;
   // The things to which an attribute can appertain
@@ -937,7 +928,6 @@ def AVRSignal : InheritableAttr, TargetSpecificAttr<TargetAVR> {
 }
 
 def AsmLabel : InheritableAttr {
-  let CanPrintOnLeft = 0;
   let Spellings = [CustomKeyword<"asm">, CustomKeyword<"__asm__">];
   let Args = [
     // Label specifies the mangled name for the decl.
@@ -1534,7 +1524,6 @@ def AllocSize : InheritableAttr {
 }
 
 def EnableIf : InheritableAttr {
-  let CanPrintOnLeft = 0;
   // Does not have a [[]] spelling because this attribute requires the ability
   // to parse function arguments but the attribute is not written in the type
   // position.
@@ -3171,7 +3160,6 @@ def Unavailable : InheritableAttr {
 }
 
 def DiagnoseIf : InheritableAttr {
-  let CanPrintOnLeft = 0;
   // Does not have a [[]] spelling because this attribute requires the ability
   // to parse function arguments but the attribute is not written in the type
   // position.

diff --git a/clang/include/clang/Basic/CMakeLists.txt b/clang/include/clang/Basic/CMakeLists.txt
@@ -31,16 +31,6 @@ clang_tablegen(AttrList.inc -gen-clang-attr-list
   SOURCE Attr.td
   TARGET ClangAttrList)
 
-clang_tablegen(AttrLeftSideCanPrintList.inc -gen-clang-attr-can-print-left-list
-  -I ${CMAKE_CURRENT_SOURCE_DIR}/../../
-  SOURCE Attr.td
-  TARGET ClangAttrCanPrintLeftList)
-
-clang_tablegen(AttrLeftSideMustPrintList.inc -gen-clang-attr-must-print-left-list
-  -I ${CMAKE_CURRENT_SOURCE_DIR}/../../
-  SOURCE Attr.td
-  TARGET ClangAttrMustPrintLeftList)
-
 clang_tablegen(AttrSubMatchRulesList.inc -gen-clang-attr-subject-match-rule-list
   -I ${CMAKE_CURRENT_SOURCE_DIR}/../../
   SOURCE Attr.td

diff --git a/clang/include/clang/Basic/DiagnosticGroups.td b/clang/include/clang/Basic/DiagnosticGroups.td
@@ -1412,6 +1412,9 @@ def MultiGPU: DiagGroup<"multi-gpu">;
 // libc and the CRT to be skipped.
 def AVRRtlibLinkingQuirks : DiagGroup<"avr-rtlib-linking-quirks">;
 
+// A warning group related to AArch64 SME function attribues.
+def AArch64SMEAttributes : DiagGroup<"aarch64-sme-attributes">;
+
 // A warning group for things that will change semantics in the future.
 def FutureCompat : DiagGroup<"future-compat">;
 

diff --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td b/clang/include/clang/Basic/DiagnosticSemaKinds.td
@@ -3755,6 +3755,16 @@ def err_sme_definition_using_za_in_non_sme_target : Error<
   "function using ZA state requires 'sme'">;
 def err_sme_definition_using_zt0_in_non_sme2_target : Error<
   "function using ZT0 state requires 'sme2'">;
+def warn_sme_streaming_pass_return_vl_to_non_streaming : Warning<
+  "passing a VL-dependent argument to/from a function that has a different"
+  " streaming-mode. The streaming and non-streaming vector lengths may be"
+  " different">,
+  InGroup<AArch64SMEAttributes>, DefaultIgnore;
+def warn_sme_locally_streaming_has_vl_args_returns : Warning<
+  "passing/returning a VL-dependent argument to/from a __arm_locally_streaming"
+  " function. The streaming and non-streaming vector"
+  " lengths may be different">,
+  InGroup<AArch64SMEAttributes>, DefaultIgnore;
 def err_conflicting_attributes_arm_state : Error<
   "conflicting attributes for state '%0'">;
 def err_sme_streaming_cannot_be_multiversioned : Error<
@@ -7142,7 +7152,8 @@ def ext_typecheck_decl_incomplete_type : ExtWarn<
 def err_tentative_def_incomplete_type : Error<
   "tentative definition has type %0 that is never completed">;
 def warn_tentative_incomplete_array : Warning<
-  "tentative array definition assumed to have one element">;
+  "tentative array definition assumed to have one element">,
+  InGroup<DiagGroup<"tentative-definition-array">>;
 def err_typecheck_incomplete_array_needs_initializer : Error<
   "definition of variable with array type needs an explicit size "
   "or an initializer">;
@@ -12252,6 +12263,12 @@ def warn_acc_clause_unimplemented
 def err_acc_construct_appertainment
     : Error<"OpenACC construct '%0' cannot be used here; it can only "
             "be used in a statement context">;
+def err_acc_clause_appertainment
+    : Error<"OpenACC '%1' clause is not valid on '%0' directive">;
+def err_acc_duplicate_clause_disallowed
+    : Error<"OpenACC '%1' clause cannot appear more than once on a '%0' "
+            "directive">;
+def note_acc_previous_clause_here : Note<"previous clause is here">;
 def err_acc_branch_in_out_compute_construct
     : Error<"invalid %select{branch|return|throw}0 %select{out of|into}1 "
             "OpenACC Compute Construct">;

diff --git a/clang/include/clang/Basic/IdentifierTable.h b/clang/include/clang/Basic/IdentifierTable.h
@@ -913,12 +913,13 @@ class alignas(IdentifierInfoAlignment) MultiKeywordSelector
 
 public:
   // Constructor for keyword selectors.
-  MultiKeywordSelector(unsigned nKeys, IdentifierInfo **IIV)
+  MultiKeywordSelector(unsigned nKeys, const IdentifierInfo **IIV)
       : DeclarationNameExtra(nKeys) {
     assert((nKeys > 1) && "not a multi-keyword selector");
 
     // Fill in the trailing keyword array.
-    IdentifierInfo **KeyInfo = reinterpret_cast<IdentifierInfo **>(this + 1);
+    const IdentifierInfo **KeyInfo =
+        reinterpret_cast<const IdentifierInfo **>(this + 1);
     for (unsigned i = 0; i != nKeys; ++i)
       KeyInfo[i] = IIV[i];
   }
@@ -928,7 +929,7 @@ class alignas(IdentifierInfoAlignment) MultiKeywordSelector
 
   using DeclarationNameExtra::getNumArgs;
 
-  using keyword_iterator = IdentifierInfo *const *;
+  using keyword_iterator = const IdentifierInfo *const *;
 
   keyword_iterator keyword_begin() const {
     return reinterpret_cast<keyword_iterator>(this + 1);
@@ -938,7 +939,7 @@ class alignas(IdentifierInfoAlignment) MultiKeywordSelector
     return keyword_begin() + getNumArgs();
   }
 
-  IdentifierInfo *getIdentifierInfoForSlot(unsigned i) const {
+  const IdentifierInfo *getIdentifierInfoForSlot(unsigned i) const {
     assert(i < getNumArgs() && "getIdentifierInfoForSlot(): illegal index");
     return keyword_begin()[i];
   }
@@ -991,10 +992,10 @@ class Selector {
   /// Do not reorder or add any arguments to this template
   /// without thoroughly understanding how tightly coupled these classes are.
   llvm::PointerIntPair<
-      llvm::PointerUnion<IdentifierInfo *, MultiKeywordSelector *>, 2>
+      llvm::PointerUnion<const IdentifierInfo *, MultiKeywordSelector *>, 2>
       InfoPtr;
 
-  Selector(IdentifierInfo *II, unsigned nArgs) {
+  Selector(const IdentifierInfo *II, unsigned nArgs) {
     assert(nArgs < 2 && "nArgs not equal to 0/1");
     InfoPtr.setPointerAndInt(II, nArgs + 1);
   }
@@ -1006,8 +1007,8 @@ class Selector {
     InfoPtr.setPointerAndInt(SI, MultiArg & 0b11);
   }
 
-  IdentifierInfo *getAsIdentifierInfo() const {
-    return InfoPtr.getPointer().dyn_cast<IdentifierInfo *>();
+  const IdentifierInfo *getAsIdentifierInfo() const {
+    return InfoPtr.getPointer().dyn_cast<const IdentifierInfo *>();
   }
 
   MultiKeywordSelector *getMultiKeywordSelector() const {
@@ -1075,7 +1076,7 @@ class Selector {
   ///
   /// \returns the uniqued identifier for this slot, or NULL if this slot has
   /// no corresponding identifier.
-  IdentifierInfo *getIdentifierInfoForSlot(unsigned argIndex) const;
+  const IdentifierInfo *getIdentifierInfoForSlot(unsigned argIndex) const;
 
   /// Retrieve the name at a given position in the selector.
   ///
@@ -1132,13 +1133,13 @@ class SelectorTable {
   ///
   /// \p NumArgs indicates whether this is a no argument selector "foo", a
   /// single argument selector "foo:" or multi-argument "foo:bar:".
-  Selector getSelector(unsigned NumArgs, IdentifierInfo **IIV);
+  Selector getSelector(unsigned NumArgs, const IdentifierInfo **IIV);
 
-  Selector getUnarySelector(IdentifierInfo *ID) {
+  Selector getUnarySelector(const IdentifierInfo *ID) {
     return Selector(ID, 1);
   }
 
-  Selector getNullarySelector(IdentifierInfo *ID) {
+  Selector getNullarySelector(const IdentifierInfo *ID) {
     return Selector(ID, 0);
   }
 

diff --git a/clang/include/clang/Basic/OpenACCKinds.h b/clang/include/clang/Basic/OpenACCKinds.h
@@ -67,7 +67,7 @@ enum class OpenACCDirectiveKind {
 };
 
 template <typename StreamTy>
-inline StreamTy &PrintOpenACCDirectiveKind(StreamTy &Out,
+inline StreamTy &printOpenACCDirectiveKind(StreamTy &Out,
                                            OpenACCDirectiveKind K) {
   switch (K) {
   case OpenACCDirectiveKind::Parallel:
@@ -138,12 +138,12 @@ inline StreamTy &PrintOpenACCDirectiveKind(StreamTy &Out,
 
 inline const StreamingDiagnostic &operator<<(const StreamingDiagnostic &Out,
                                              OpenACCDirectiveKind K) {
-  return PrintOpenACCDirectiveKind(Out, K);
+  return printOpenACCDirectiveKind(Out, K);
 }
 
 inline llvm::raw_ostream &operator<<(llvm::raw_ostream &Out,
                                      OpenACCDirectiveKind K) {
-  return PrintOpenACCDirectiveKind(Out, K);
+  return printOpenACCDirectiveKind(Out, K);
 }
 
 enum class OpenACCAtomicKind {
@@ -266,7 +266,7 @@ enum class OpenACCClauseKind {
 };
 
 template <typename StreamTy>
-inline StreamTy &PrintOpenACCClauseKind(StreamTy &Out, OpenACCClauseKind K) {
+inline StreamTy &printOpenACCClauseKind(StreamTy &Out, OpenACCClauseKind K) {
   switch (K) {
   case OpenACCClauseKind::Finalize:
     return Out << "finalize";
@@ -402,12 +402,12 @@ inline StreamTy &PrintOpenACCClauseKind(StreamTy &Out, OpenACCClauseKind K) {
 
 inline const StreamingDiagnostic &operator<<(const StreamingDiagnostic &Out,
                                              OpenACCClauseKind K) {
-  return PrintOpenACCClauseKind(Out, K);
+  return printOpenACCClauseKind(Out, K);
 }
 
 inline llvm::raw_ostream &operator<<(llvm::raw_ostream &Out,
                                      OpenACCClauseKind K) {
-  return PrintOpenACCClauseKind(Out, K);
+  return printOpenACCClauseKind(Out, K);
 }
 
 enum class OpenACCDefaultClauseKind {
@@ -419,6 +419,30 @@ enum class OpenACCDefaultClauseKind {
   Invalid,
 };
 
+template <typename StreamTy>
+inline StreamTy &printOpenACCDefaultClauseKind(StreamTy &Out,
+                                               OpenACCDefaultClauseKind K) {
+  switch (K) {
+  case OpenACCDefaultClauseKind::None:
+    return Out << "none";
+  case OpenACCDefaultClauseKind::Present:
+    return Out << "present";
+  case OpenACCDefaultClauseKind::Invalid:
+    return Out << "<invalid>";
+  }
+  llvm_unreachable("Unknown OpenACCDefaultClauseKind enum");
+}
+
+inline const StreamingDiagnostic &operator<<(const StreamingDiagnostic &Out,
+                                             OpenACCDefaultClauseKind K) {
+  return printOpenACCDefaultClauseKind(Out, K);
+}
+
+inline llvm::raw_ostream &operator<<(llvm::raw_ostream &Out,
+                                     OpenACCDefaultClauseKind K) {
+  return printOpenACCDefaultClauseKind(Out, K);
+}
+
 enum class OpenACCReductionOperator {
   /// '+'.
   Addition,

diff --git a/clang/include/clang/Basic/Sanitizers.def b/clang/include/clang/Basic/Sanitizers.def
@@ -163,24 +163,24 @@ SANITIZER_GROUP("implicit-integer-arithmetic-value-change",
                 ImplicitIntegerArithmeticValueChange,
                 ImplicitIntegerSignChange | ImplicitSignedIntegerTruncation)
 
-SANITIZER("objc-cast", ObjCCast)
+SANITIZER_GROUP("implicit-integer-conversion", ImplicitIntegerConversion,
+                ImplicitIntegerArithmeticValueChange |
+                    ImplicitUnsignedIntegerTruncation)
 
-// FIXME:
-//SANITIZER_GROUP("implicit-integer-conversion", ImplicitIntegerConversion,
-//                ImplicitIntegerArithmeticValueChange |
-//                    ImplicitUnsignedIntegerTruncation)
-//SANITIZER_GROUP("implicit-conversion", ImplicitConversion,
-//                ImplicitIntegerConversion)
+// Implicit bitfield sanitizers
+SANITIZER("implicit-bitfield-conversion", ImplicitBitfieldConversion)
 
 SANITIZER_GROUP("implicit-conversion", ImplicitConversion,
-                ImplicitIntegerArithmeticValueChange |
-                    ImplicitUnsignedIntegerTruncation)
+                ImplicitIntegerConversion |
+                    ImplicitBitfieldConversion)
 
 SANITIZER_GROUP("integer", Integer,
-                ImplicitConversion | IntegerDivideByZero | Shift |
+                ImplicitIntegerConversion | IntegerDivideByZero | Shift |
                     SignedIntegerOverflow | UnsignedIntegerOverflow |
                     UnsignedShiftBase)
 
+SANITIZER("objc-cast", ObjCCast)
+
 SANITIZER("local-bounds", LocalBounds)
 SANITIZER_GROUP("bounds", Bounds, ArrayBounds | LocalBounds)
 

diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td
@@ -1449,7 +1449,7 @@ def dD : Flag<["-"], "dD">, Group<d_Group>, Visibility<[ClangOption, CC1Option]>
 def dI : Flag<["-"], "dI">, Group<d_Group>, Visibility<[ClangOption, CC1Option]>,
   HelpText<"Print include directives in -E mode in addition to normal output">,
   MarshallingInfoFlag<PreprocessorOutputOpts<"ShowIncludeDirectives">>;
-def dM : Flag<["-"], "dM">, Group<d_Group>, Visibility<[ClangOption, CC1Option]>,
+def dM : Flag<["-"], "dM">, Group<d_Group>, Visibility<[ClangOption, CC1Option, FlangOption, FC1Option]>,
   HelpText<"Print macro definitions in -E mode instead of normal output">;
 def dead__strip : Flag<["-"], "dead_strip">;
 def dependency_file : Separate<["-"], "dependency-file">,
@@ -4912,6 +4912,9 @@ defm tgsplit : SimpleMFlag<"tgsplit", "Enable", "Disable",
 defm wavefrontsize64 : SimpleMFlag<"wavefrontsize64",
   "Specify wavefront size 64", "Specify wavefront size 32",
   " mode (AMDGPU only)">;
+defm amdgpu_precise_memory_op
+    : SimpleMFlag<"amdgpu-precise-memory-op", "Enable", "Disable",
+                  " precise memory mode (AMDGPU only)">;
 
 defm unsafe_fp_atomics : BoolMOption<"unsafe-fp-atomics",
   TargetOpts<"AllowAMDGPUUnsafeFPAtomics">, DefaultFalse,

diff --git a/clang/include/clang/Frontend/FrontendActions.h b/clang/include/clang/Frontend/FrontendActions.h
@@ -34,18 +34,12 @@ class InitOnlyAction : public FrontendAction {
 
 /// Preprocessor-based frontend action that also loads PCH files.
 class ReadPCHAndPreprocessAction : public FrontendAction {
-  llvm::unique_function<void(CompilerInstance &)> AdjustCI;
-
   void ExecuteAction() override;
 
   std::unique_ptr<ASTConsumer> CreateASTConsumer(CompilerInstance &CI,
                                                  StringRef InFile) override;
 
 public:
-  ReadPCHAndPreprocessAction(
-      llvm::unique_function<void(CompilerInstance &)> AdjustCI)
-      : AdjustCI(std::move(AdjustCI)) {}
-
   bool usesPreprocessorOnly() const override { return false; }
 };
 
@@ -327,15 +321,11 @@ class PrintPreprocessedAction : public PreprocessorFrontendAction {
 
 class GetDependenciesByModuleNameAction : public PreprocessOnlyAction {
   StringRef ModuleName;
-  llvm::unique_function<void(CompilerInstance &)> AdjustCI;
-
   void ExecuteAction() override;
 
 public:
-  GetDependenciesByModuleNameAction(
-      StringRef ModuleName,
-      llvm::unique_function<void(CompilerInstance &)> AdjustCI)
-      : ModuleName(ModuleName), AdjustCI(std::move(AdjustCI)) {}
+  GetDependenciesByModuleNameAction(StringRef ModuleName)
+      : ModuleName(ModuleName) {}
 };
 
 }  // end namespace clang

diff --git a/clang/include/clang/InstallAPI/DylibVerifier.h b/clang/include/clang/InstallAPI/DylibVerifier.h
@@ -10,6 +10,7 @@
 #define LLVM_CLANG_INSTALLAPI_DYLIBVERIFIER_H
 
 #include "clang/Basic/Diagnostic.h"
+#include "clang/Basic/SourceManager.h"
 #include "clang/InstallAPI/MachO.h"
 
 namespace clang {
@@ -99,11 +100,7 @@ class DylibVerifier : llvm::MachO::RecordVisitor {
   Result getState() const { return Ctx.FrontendState; }
 
   /// Set different source managers to the same diagnostics engine.
-  void setSourceManager(SourceManager &SourceMgr) const {
-    if (!Ctx.Diag)
-      return;
-    Ctx.Diag->setSourceManager(&SourceMgr);
-  }
+  void setSourceManager(IntrusiveRefCntPtr<SourceManager> SourceMgr);
 
 private:
   /// Determine whether to compare declaration to symbol in binary.
@@ -190,6 +187,9 @@ class DylibVerifier : llvm::MachO::RecordVisitor {
 
   // Track DWARF provided source location for dylibs.
   DWARFContext *DWARFCtx = nullptr;
+
+  // Source manager for each unique compiler instance.
+  llvm::SmallVector<IntrusiveRefCntPtr<SourceManager>, 12> SourceManagers;
 };
 
 } // namespace installapi

diff --git a/clang/include/clang/InstallAPI/Frontend.h b/clang/include/clang/InstallAPI/Frontend.h
@@ -36,7 +36,7 @@ class InstallAPIAction : public ASTFrontendAction {
   std::unique_ptr<ASTConsumer> CreateASTConsumer(CompilerInstance &CI,
                                                  StringRef InFile) override {
     Ctx.Diags->getClient()->BeginSourceFile(CI.getLangOpts());
-    Ctx.Verifier->setSourceManager(CI.getSourceManager());
+    Ctx.Verifier->setSourceManager(CI.getSourceManagerPtr());
     return std::make_unique<InstallAPIVisitor>(
         CI.getASTContext(), Ctx, CI.getSourceManager(), CI.getPreprocessor());
   }

diff --git a/clang/include/clang/InstallAPI/FrontendRecords.h b/clang/include/clang/InstallAPI/FrontendRecords.h
@@ -21,6 +21,7 @@ namespace installapi {
 struct FrontendAttrs {
   const AvailabilityInfo Avail;
   const Decl *D;
+  const SourceLocation Loc;
   const HeaderType Access;
 };
 

diff --git a/clang/include/clang/Lex/ExternalPreprocessorSource.h b/clang/include/clang/Lex/ExternalPreprocessorSource.h
@@ -31,7 +31,7 @@ class ExternalPreprocessorSource {
   virtual void ReadDefinedMacros() = 0;
 
   /// Update an out-of-date identifier.
-  virtual void updateOutOfDateIdentifier(IdentifierInfo &II) = 0;
+  virtual void updateOutOfDateIdentifier(const IdentifierInfo &II) = 0;
 
   /// Return the identifier associated with the given ID number.
   ///

diff --git a/clang/include/clang/Lex/MacroInfo.h b/clang/include/clang/Lex/MacroInfo.h
@@ -515,7 +515,7 @@ class ModuleMacro : public llvm::FoldingSetNode {
   friend class Preprocessor;
 
   /// The name defined by the macro.
-  IdentifierInfo *II;
+  const IdentifierInfo *II;
 
   /// The body of the #define, or nullptr if this is a #undef.
   MacroInfo *Macro;
@@ -529,7 +529,7 @@ class ModuleMacro : public llvm::FoldingSetNode {
   /// The number of modules whose macros are directly overridden by this one.
   unsigned NumOverrides;
 
-  ModuleMacro(Module *OwningModule, IdentifierInfo *II, MacroInfo *Macro,
+  ModuleMacro(Module *OwningModule, const IdentifierInfo *II, MacroInfo *Macro,
               ArrayRef<ModuleMacro *> Overrides)
       : II(II), Macro(Macro), OwningModule(OwningModule),
         NumOverrides(Overrides.size()) {
@@ -539,7 +539,7 @@ class ModuleMacro : public llvm::FoldingSetNode {
 
 public:
   static ModuleMacro *create(Preprocessor &PP, Module *OwningModule,
-                             IdentifierInfo *II, MacroInfo *Macro,
+                             const IdentifierInfo *II, MacroInfo *Macro,
                              ArrayRef<ModuleMacro *> Overrides);
 
   void Profile(llvm::FoldingSetNodeID &ID) const {
@@ -553,7 +553,7 @@ class ModuleMacro : public llvm::FoldingSetNode {
   }
 
   /// Get the name of the macro.
-  IdentifierInfo *getName() const { return II; }
+  const IdentifierInfo *getName() const { return II; }
 
   /// Get the ID of the module that exports this macro.
   Module *getOwningModule() const { return OwningModule; }

diff --git a/clang/include/clang/Lex/Preprocessor.h b/clang/include/clang/Lex/Preprocessor.h
@@ -736,19 +736,6 @@ class Preprocessor {
     State ConditionalStackState = Off;
   } PreambleConditionalStack;
 
-  /// Function for getting the dependency preprocessor directives of a file.
-  ///
-  /// These are directives derived from a special form of lexing where the
-  /// source input is scanned for the preprocessor directives that might have an
-  /// effect on the dependencies for a compilation unit.
-  ///
-  /// Enables a client to cache the directives for a file and provide them
-  /// across multiple compiler invocations.
-  /// FIXME: Allow returning an error.
-  using DependencyDirectivesFn = llvm::unique_function<std::optional<
-      ArrayRef<dependency_directives_scan::Directive>>(FileEntryRef)>;
-  DependencyDirectivesFn DependencyDirectivesForFile;
-
   /// The current top of the stack that we're lexing from if
   /// not expanding a macro and we are lexing directly from source code.
   ///
@@ -849,7 +836,7 @@ class Preprocessor {
     ModuleMacroInfo *getModuleInfo(Preprocessor &PP,
                                    const IdentifierInfo *II) const {
       if (II->isOutOfDate())
-        PP.updateOutOfDateIdentifier(const_cast<IdentifierInfo&>(*II));
+        PP.updateOutOfDateIdentifier(*II);
       // FIXME: Find a spare bit on IdentifierInfo and store a
       //        HasModuleMacros flag.
       if (!II->hasMacroDefinition() ||
@@ -1175,7 +1162,7 @@ class Preprocessor {
   /// skipped.
   llvm::DenseMap<const char *, unsigned> RecordedSkippedRanges;
 
-  void updateOutOfDateIdentifier(IdentifierInfo &II) const;
+  void updateOutOfDateIdentifier(const IdentifierInfo &II) const;
 
 public:
   Preprocessor(std::shared_ptr<PreprocessorOptions> PPOpts,
@@ -1283,11 +1270,6 @@ class Preprocessor {
   /// false if it is producing tokens to be consumed by Parse and Sema.
   bool isPreprocessedOutput() const { return PreprocessedOutput; }
 
-  /// Set the function used to get dependency directives for a file.
-  void setDependencyDirectivesFn(DependencyDirectivesFn Fn) {
-    DependencyDirectivesForFile = std::move(Fn);
-  }
-
   /// Return true if we are lexing directly from the specified lexer.
   bool isCurrentLexer(const PreprocessorLexer *L) const {
     return CurPPLexer == L;
@@ -1450,14 +1432,15 @@ class Preprocessor {
                                MacroDirective *MD);
 
   /// Register an exported macro for a module and identifier.
-  ModuleMacro *addModuleMacro(Module *Mod, IdentifierInfo *II, MacroInfo *Macro,
+  ModuleMacro *addModuleMacro(Module *Mod, const IdentifierInfo *II,
+                              MacroInfo *Macro,
                               ArrayRef<ModuleMacro *> Overrides, bool &IsNew);
   ModuleMacro *getModuleMacro(Module *Mod, const IdentifierInfo *II);
 
   /// Get the list of leaf (non-overridden) module macros for a name.
   ArrayRef<ModuleMacro*> getLeafModuleMacros(const IdentifierInfo *II) const {
     if (II->isOutOfDate())
-      updateOutOfDateIdentifier(const_cast<IdentifierInfo&>(*II));
+      updateOutOfDateIdentifier(*II);
     auto I = LeafModuleMacros.find(II);
     if (I != LeafModuleMacros.end())
       return I->second;

diff --git a/clang/include/clang/Lex/PreprocessorOptions.h b/clang/include/clang/Lex/PreprocessorOptions.h
@@ -186,6 +186,19 @@ class PreprocessorOptions {
   /// with support for lifetime-qualified pointers.
   ObjCXXARCStandardLibraryKind ObjCXXARCStandardLibrary = ARCXX_nolib;
 
+  /// Function for getting the dependency preprocessor directives of a file.
+  ///
+  /// These are directives derived from a special form of lexing where the
+  /// source input is scanned for the preprocessor directives that might have an
+  /// effect on the dependencies for a compilation unit.
+  ///
+  /// Enables a client to cache the directives for a file and provide them
+  /// across multiple compiler invocations.
+  /// FIXME: Allow returning an error.
+  std::function<std::optional<ArrayRef<dependency_directives_scan::Directive>>(
+      FileEntryRef)>
+      DependencyDirectivesForFile;
+
   /// Set up preprocessor for RunAnalysis action.
   bool SetUpStaticAnalyzer = false;
 

diff --git a/clang/include/clang/Parse/Parser.h b/clang/include/clang/Parse/Parser.h
@@ -41,6 +41,7 @@ namespace clang {
   class InMessageExpressionRAIIObject;
   class PoisonSEHIdentifiersRAIIObject;
   class OMPClause;
+  class OpenACCClause;
   class ObjCTypeParamList;
   struct OMPTraitProperty;
   struct OMPTraitSelector;
@@ -328,7 +329,7 @@ class Parser : public CodeCompletionHandler {
   };
 
   /// Identifiers which have been declared within a tentative parse.
-  SmallVector<IdentifierInfo *, 8> TentativelyDeclaredIdentifiers;
+  SmallVector<const IdentifierInfo *, 8> TentativelyDeclaredIdentifiers;
 
   /// Tracker for '<' tokens that might have been intended to be treated as an
   /// angle bracket instead of a less-than comparison.
@@ -1926,15 +1927,11 @@ class Parser : public CodeCompletionHandler {
                                   bool EnteringContext, IdentifierInfo &II,
                                   CXXScopeSpec &SS);
 
-  bool ParseOptionalCXXScopeSpecifier(CXXScopeSpec &SS,
-                                      ParsedType ObjectType,
-                                      bool ObjectHasErrors,
-                                      bool EnteringContext,
-                                      bool *MayBePseudoDestructor = nullptr,
-                                      bool IsTypename = false,
-                                      IdentifierInfo **LastII = nullptr,
-                                      bool OnlyNamespace = false,
-                                      bool InUsingDeclaration = false);
+  bool ParseOptionalCXXScopeSpecifier(
+      CXXScopeSpec &SS, ParsedType ObjectType, bool ObjectHasErrors,
+      bool EnteringContext, bool *MayBePseudoDestructor = nullptr,
+      bool IsTypename = false, const IdentifierInfo **LastII = nullptr,
+      bool OnlyNamespace = false, bool InUsingDeclaration = false);
 
   //===--------------------------------------------------------------------===//
   // C++11 5.1.2: Lambda expressions
@@ -3594,11 +3591,26 @@ class Parser : public CodeCompletionHandler {
     OpenACCDirectiveKind DirKind;
     SourceLocation StartLoc;
     SourceLocation EndLoc;
-    // TODO OpenACC: Add Clause list here once we have a type for that.
+    SmallVector<OpenACCClause *> Clauses;
     // TODO OpenACC: As we implement support for the Atomic, Routine, Cache, and
     // Wait constructs, we likely want to put that information in here as well.
   };
 
+  /// Represents the 'error' state of parsing an OpenACC Clause, and stores
+  /// whether we can continue parsing, or should give up on the directive.
+  enum class OpenACCParseCanContinue { Cannot = 0, Can = 1 };
+
+  /// A type to represent the state of parsing an OpenACC Clause. Situations
+  /// that result in an OpenACCClause pointer are a success and can continue
+  /// parsing, however some other situations can also continue.
+  /// FIXME: This is better represented as a std::expected when we get C++23.
+  using OpenACCClauseParseResult =
+      llvm::PointerIntPair<OpenACCClause *, 1, OpenACCParseCanContinue>;
+
+  OpenACCClauseParseResult OpenACCCanContinue();
+  OpenACCClauseParseResult OpenACCCannotContinue();
+  OpenACCClauseParseResult OpenACCSuccess(OpenACCClause *Clause);
+
   /// Parses the OpenACC directive (the entire pragma) including the clause
   /// list, but does not produce the main AST node.
   OpenACCDirectiveParseInfo ParseOpenACCDirective();
@@ -3613,12 +3625,18 @@ class Parser : public CodeCompletionHandler {
   bool ParseOpenACCClauseVarList(OpenACCClauseKind Kind);
   /// Parses any parameters for an OpenACC Clause, including required/optional
   /// parens.
-  bool ParseOpenACCClauseParams(OpenACCDirectiveKind DirKind,
-                                OpenACCClauseKind Kind);
-  /// Parses a single clause in a clause-list for OpenACC.
-  bool ParseOpenACCClause(OpenACCDirectiveKind DirKind);
+  OpenACCClauseParseResult
+  ParseOpenACCClauseParams(ArrayRef<const OpenACCClause *> ExistingClauses,
+                           OpenACCDirectiveKind DirKind, OpenACCClauseKind Kind,
+                           SourceLocation ClauseLoc);
+  /// Parses a single clause in a clause-list for OpenACC. Returns nullptr on
+  /// error.
+  OpenACCClauseParseResult
+  ParseOpenACCClause(ArrayRef<const OpenACCClause *> ExistingClauses,
+                     OpenACCDirectiveKind DirKind);
   /// Parses the clause-list for an OpenACC directive.
-  void ParseOpenACCClauseList(OpenACCDirectiveKind DirKind);
+  SmallVector<OpenACCClause *>
+  ParseOpenACCClauseList(OpenACCDirectiveKind DirKind);
   bool ParseOpenACCWaitArgument();
   /// Parses the clause of the 'bind' argument, which can be a string literal or
   /// an ID expression.

diff --git a/clang/include/clang/Sema/CodeCompleteConsumer.h b/clang/include/clang/Sema/CodeCompleteConsumer.h
@@ -362,7 +362,7 @@ class CodeCompletionContext {
   QualType BaseType;
 
   /// The identifiers for Objective-C selector parts.
-  ArrayRef<IdentifierInfo *> SelIdents;
+  ArrayRef<const IdentifierInfo *> SelIdents;
 
   /// The scope specifier that comes before the completion token e.g.
   /// "a::b::"
@@ -378,8 +378,9 @@ class CodeCompletionContext {
       : CCKind(CCKind), IsUsingDeclaration(false), SelIdents(std::nullopt) {}
 
   /// Construct a new code-completion context of the given kind.
-  CodeCompletionContext(Kind CCKind, QualType T,
-                        ArrayRef<IdentifierInfo *> SelIdents = std::nullopt)
+  CodeCompletionContext(
+      Kind CCKind, QualType T,
+      ArrayRef<const IdentifierInfo *> SelIdents = std::nullopt)
       : CCKind(CCKind), IsUsingDeclaration(false), SelIdents(SelIdents) {
     if (CCKind == CCC_DotMemberAccess || CCKind == CCC_ArrowMemberAccess ||
         CCKind == CCC_ObjCPropertyAccess || CCKind == CCC_ObjCClassMessage ||
@@ -406,7 +407,7 @@ class CodeCompletionContext {
   QualType getBaseType() const { return BaseType; }
 
   /// Retrieve the Objective-C selector identifiers.
-  ArrayRef<IdentifierInfo *> getSelIdents() const { return SelIdents; }
+  ArrayRef<const IdentifierInfo *> getSelIdents() const { return SelIdents; }
 
   /// Determines whether we want C++ constructors as results within this
   /// context.

diff --git a/clang/include/clang/Sema/DeclSpec.h b/clang/include/clang/Sema/DeclSpec.h
@@ -1049,7 +1049,7 @@ class UnqualifiedId {
   union {
     /// When Kind == IK_Identifier, the parsed identifier, or when
     /// Kind == IK_UserLiteralId, the identifier suffix.
-    IdentifierInfo *Identifier;
+    const IdentifierInfo *Identifier;
 
     /// When Kind == IK_OperatorFunctionId, the overloaded operator
     /// that we parsed.
@@ -1111,7 +1111,7 @@ class UnqualifiedId {
   /// \param IdLoc the location of the parsed identifier.
   void setIdentifier(const IdentifierInfo *Id, SourceLocation IdLoc) {
     Kind = UnqualifiedIdKind::IK_Identifier;
-    Identifier = const_cast<IdentifierInfo *>(Id);
+    Identifier = Id;
     StartLocation = EndLocation = IdLoc;
   }
 
@@ -1154,9 +1154,9 @@ class UnqualifiedId {
   ///
   /// \param IdLoc the location of the identifier.
   void setLiteralOperatorId(const IdentifierInfo *Id, SourceLocation OpLoc,
-                              SourceLocation IdLoc) {
+                            SourceLocation IdLoc) {
     Kind = UnqualifiedIdKind::IK_LiteralOperatorId;
-    Identifier = const_cast<IdentifierInfo *>(Id);
+    Identifier = Id;
     StartLocation = OpLoc;
     EndLocation = IdLoc;
   }
@@ -1225,7 +1225,7 @@ class UnqualifiedId {
   /// \param Id the identifier.
   void setImplicitSelfParam(const IdentifierInfo *Id) {
     Kind = UnqualifiedIdKind::IK_ImplicitSelfParam;
-    Identifier = const_cast<IdentifierInfo *>(Id);
+    Identifier = Id;
     StartLocation = EndLocation = SourceLocation();
   }
 
@@ -1327,7 +1327,7 @@ struct DeclaratorChunk {
   /// Parameter type lists will have type info (if the actions module provides
   /// it), but may have null identifier info: e.g. for 'void foo(int X, int)'.
   struct ParamInfo {
-    IdentifierInfo *Ident;
+    const IdentifierInfo *Ident;
     SourceLocation IdentLoc;
     Decl *Param;
 
@@ -1339,11 +1339,10 @@ struct DeclaratorChunk {
     std::unique_ptr<CachedTokens> DefaultArgTokens;
 
     ParamInfo() = default;
-    ParamInfo(IdentifierInfo *ident, SourceLocation iloc,
-              Decl *param,
+    ParamInfo(const IdentifierInfo *ident, SourceLocation iloc, Decl *param,
               std::unique_ptr<CachedTokens> DefArgTokens = nullptr)
-      : Ident(ident), IdentLoc(iloc), Param(param),
-        DefaultArgTokens(std::move(DefArgTokens)) {}
+        : Ident(ident), IdentLoc(iloc), Param(param),
+          DefaultArgTokens(std::move(DefArgTokens)) {}
   };
 
   struct TypeAndRange {
@@ -2326,7 +2325,7 @@ class Declarator {
     return BindingGroup.isSet();
   }
 
-  IdentifierInfo *getIdentifier() const {
+  const IdentifierInfo *getIdentifier() const {
     if (Name.getKind() == UnqualifiedIdKind::IK_Identifier)
       return Name.Identifier;
 
@@ -2335,7 +2334,7 @@ class Declarator {
   SourceLocation getIdentifierLoc() const { return Name.StartLocation; }
 
   /// Set the name of this declarator to be the given identifier.
-  void SetIdentifier(IdentifierInfo *Id, SourceLocation IdLoc) {
+  void SetIdentifier(const IdentifierInfo *Id, SourceLocation IdLoc) {
     Name.setIdentifier(Id, IdLoc);
   }
 

diff --git a/clang/include/clang/Sema/ParsedTemplate.h b/clang/include/clang/Sema/ParsedTemplate.h
@@ -159,7 +159,7 @@ namespace clang {
     SourceLocation TemplateNameLoc;
 
     /// FIXME: Temporarily stores the name of a specialization
-    IdentifierInfo *Name;
+    const IdentifierInfo *Name;
 
     /// FIXME: Temporarily stores the overloaded operator kind.
     OverloadedOperatorKind Operator;
@@ -197,7 +197,7 @@ namespace clang {
     /// appends it to List.
     static TemplateIdAnnotation *
     Create(SourceLocation TemplateKWLoc, SourceLocation TemplateNameLoc,
-           IdentifierInfo *Name, OverloadedOperatorKind OperatorKind,
+           const IdentifierInfo *Name, OverloadedOperatorKind OperatorKind,
            ParsedTemplateTy OpaqueTemplateName, TemplateNameKind TemplateKind,
            SourceLocation LAngleLoc, SourceLocation RAngleLoc,
            ArrayRef<ParsedTemplateArgument> TemplateArgs, bool ArgsInvalid,
@@ -236,7 +236,8 @@ namespace clang {
     TemplateIdAnnotation(const TemplateIdAnnotation &) = delete;
 
     TemplateIdAnnotation(SourceLocation TemplateKWLoc,
-                         SourceLocation TemplateNameLoc, IdentifierInfo *Name,
+                         SourceLocation TemplateNameLoc,
+                         const IdentifierInfo *Name,
                          OverloadedOperatorKind OperatorKind,
                          ParsedTemplateTy OpaqueTemplateName,
                          TemplateNameKind TemplateKind,

diff --git a/clang/include/clang/Sema/Sema.h b/clang/include/clang/Sema/Sema.h
diff --git a/clang/include/clang/Sema/SemaHLSL.h b/clang/include/clang/Sema/SemaHLSL.h
@@ -0,0 +1,37 @@
+//===----- SemaHLSL.h ----- Semantic Analysis for HLSL constructs ---------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+/// \file
+/// This file declares semantic analysis for HLSL constructs.
+///
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CLANG_SEMA_SEMAHLSL_H
+#define LLVM_CLANG_SEMA_SEMAHLSL_H
+
+#include "clang/AST/DeclBase.h"
+#include "clang/AST/Expr.h"
+#include "clang/Basic/IdentifierTable.h"
+#include "clang/Basic/SourceLocation.h"
+#include "clang/Sema/Scope.h"
+#include "clang/Sema/SemaBase.h"
+
+namespace clang {
+
+class SemaHLSL : public SemaBase {
+public:
+  SemaHLSL(Sema &S);
+
+  Decl *ActOnStartHLSLBuffer(Scope *BufferScope, bool CBuffer,
+                             SourceLocation KwLoc, IdentifierInfo *Ident,
+                             SourceLocation IdentLoc, SourceLocation LBrace);
+  void ActOnFinishHLSLBuffer(Decl *Dcl, SourceLocation RBrace);
+};
+
+} // namespace clang
+
+#endif // LLVM_CLANG_SEMA_SEMAHLSL_H
diff --git a/clang/include/clang/Sema/SemaOpenACC.h b/clang/include/clang/Sema/SemaOpenACC.h
@@ -19,15 +19,65 @@
 #include "clang/Basic/SourceLocation.h"
 #include "clang/Sema/Ownership.h"
 #include "clang/Sema/SemaBase.h"
+#include <variant>
 
 namespace clang {
+class OpenACCClause;
 
 class SemaOpenACC : public SemaBase {
 public:
+  /// A type to represent all the data for an OpenACC Clause that has been
+  /// parsed, but not yet created/semantically analyzed. This is effectively a
+  /// discriminated union on the 'Clause Kind', with all of the individual
+  /// clause details stored in a std::variant.
+  class OpenACCParsedClause {
+    OpenACCDirectiveKind DirKind;
+    OpenACCClauseKind ClauseKind;
+    SourceRange ClauseRange;
+    SourceLocation LParenLoc;
+
+    struct DefaultDetails {
+      OpenACCDefaultClauseKind DefaultClauseKind;
+    };
+
+    std::variant<DefaultDetails> Details;
+
+  public:
+    OpenACCParsedClause(OpenACCDirectiveKind DirKind,
+                        OpenACCClauseKind ClauseKind, SourceLocation BeginLoc)
+        : DirKind(DirKind), ClauseKind(ClauseKind), ClauseRange(BeginLoc, {}) {}
+
+    OpenACCDirectiveKind getDirectiveKind() const { return DirKind; }
+
+    OpenACCClauseKind getClauseKind() const { return ClauseKind; }
+
+    SourceLocation getBeginLoc() const { return ClauseRange.getBegin(); }
+
+    SourceLocation getLParenLoc() const { return LParenLoc; }
+
+    SourceLocation getEndLoc() const { return ClauseRange.getEnd(); }
+
+    OpenACCDefaultClauseKind getDefaultClauseKind() const {
+      assert(ClauseKind == OpenACCClauseKind::Default &&
+             "Parsed clause is not a default clause");
+      return std::get<DefaultDetails>(Details).DefaultClauseKind;
+    }
+
+    void setLParenLoc(SourceLocation EndLoc) { LParenLoc = EndLoc; }
+    void setEndLoc(SourceLocation EndLoc) { ClauseRange.setEnd(EndLoc); }
+
+    void setDefaultDetails(OpenACCDefaultClauseKind DefKind) {
+      assert(ClauseKind == OpenACCClauseKind::Default &&
+             "Parsed clause is not a default clause");
+      Details = DefaultDetails{DefKind};
+    }
+  };
+
   SemaOpenACC(Sema &S);
 
   /// Called after parsing an OpenACC Clause so that it can be checked.
-  bool ActOnClause(OpenACCClauseKind ClauseKind, SourceLocation StartLoc);
+  OpenACCClause *ActOnClause(ArrayRef<const OpenACCClause *> ExistingClauses,
+                             OpenACCParsedClause &Clause);
 
   /// Called after the construct has been parsed, but clauses haven't been
   /// parsed.  This allows us to diagnose not-implemented, as well as set up any
@@ -53,7 +103,10 @@ class SemaOpenACC : public SemaBase {
   /// declaration group or associated statement.
   StmtResult ActOnEndStmtDirective(OpenACCDirectiveKind K,
                                    SourceLocation StartLoc,
-                                   SourceLocation EndLoc, StmtResult AssocStmt);
+                                   SourceLocation EndLoc,
+                                   ArrayRef<OpenACCClause *> Clauses,
+                                   StmtResult AssocStmt);
+
   /// Called after the directive has been completely parsed, including the
   /// declaration group or associated statement.
   DeclGroupRef ActOnEndDeclDirective();

diff --git a/clang/include/clang/Sema/SemaSYCL.h b/clang/include/clang/Sema/SemaSYCL.h
@@ -0,0 +1,65 @@
+//===----- SemaSYCL.h ------- Semantic Analysis for SYCL constructs -------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+/// \file
+/// This file declares semantic analysis for SYCL constructs.
+///
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CLANG_SEMA_SEMASYCL_H
+#define LLVM_CLANG_SEMA_SEMASYCL_H
+
+#include "clang/AST/Decl.h"
+#include "clang/AST/Type.h"
+#include "clang/Basic/SourceLocation.h"
+#include "clang/Sema/Ownership.h"
+#include "clang/Sema/SemaBase.h"
+#include "llvm/ADT/DenseSet.h"
+
+namespace clang {
+
+class SemaSYCL : public SemaBase {
+public:
+  SemaSYCL(Sema &S);
+
+  /// Creates a SemaDiagnosticBuilder that emits the diagnostic if the current
+  /// context is "used as device code".
+  ///
+  /// - If CurLexicalContext is a kernel function or it is known that the
+  ///   function will be emitted for the device, emits the diagnostics
+  ///   immediately.
+  /// - If CurLexicalContext is a function and we are compiling
+  ///   for the device, but we don't know yet that this function will be
+  ///   codegen'ed for the devive, creates a diagnostic which is emitted if and
+  ///   when we realize that the function will be codegen'ed.
+  ///
+  /// Example usage:
+  ///
+  /// Diagnose __float128 type usage only from SYCL device code if the current
+  /// target doesn't support it
+  /// if (!S.Context.getTargetInfo().hasFloat128Type() &&
+  ///     S.getLangOpts().SYCLIsDevice)
+  ///   DiagIfDeviceCode(Loc, diag::err_type_unsupported) << "__float128";
+  SemaDiagnosticBuilder DiagIfDeviceCode(SourceLocation Loc, unsigned DiagID);
+
+  void deepTypeCheckForDevice(SourceLocation UsedAt,
+                              llvm::DenseSet<QualType> Visited,
+                              ValueDecl *DeclToCheck);
+
+  ExprResult BuildUniqueStableNameExpr(SourceLocation OpLoc,
+                                       SourceLocation LParen,
+                                       SourceLocation RParen,
+                                       TypeSourceInfo *TSI);
+  ExprResult ActOnUniqueStableNameExpr(SourceLocation OpLoc,
+                                       SourceLocation LParen,
+                                       SourceLocation RParen,
+                                       ParsedType ParsedTy);
+};
+
+} // namespace clang
+
+#endif // LLVM_CLANG_SEMA_SEMASYCL_H
diff --git a/clang/include/clang/Serialization/ASTReader.h b/clang/include/clang/Serialization/ASTReader.h
@@ -1082,34 +1082,20 @@ class ASTReader
 
   /// The set of lookup results that we have faked in order to support
   /// merging of partially deserialized decls but that we have not yet removed.
-  llvm::SmallMapVector<IdentifierInfo *, SmallVector<NamedDecl*, 2>, 16>
-    PendingFakeLookupResults;
+  llvm::SmallMapVector<const IdentifierInfo *, SmallVector<NamedDecl *, 2>, 16>
+      PendingFakeLookupResults;
 
   /// The generation number of each identifier, which keeps track of
   /// the last time we loaded information about this identifier.
-  llvm::DenseMap<IdentifierInfo *, unsigned> IdentifierGeneration;
-
-  class InterestingDecl {
-    Decl *D;
-    bool DeclHasPendingBody;
-
-  public:
-    InterestingDecl(Decl *D, bool HasBody)
-        : D(D), DeclHasPendingBody(HasBody) {}
-
-    Decl *getDecl() { return D; }
-
-    /// Whether the declaration has a pending body.
-    bool hasPendingBody() { return DeclHasPendingBody; }
-  };
+  llvm::DenseMap<const IdentifierInfo *, unsigned> IdentifierGeneration;
 
   /// Contains declarations and definitions that could be
   /// "interesting" to the ASTConsumer, when we get that AST consumer.
   ///
   /// "Interesting" declarations are those that have data that may
   /// need to be emitted, such as inline function definitions or
   /// Objective-C protocols.
-  std::deque<InterestingDecl> PotentiallyInterestingDecls;
+  std::deque<Decl *> PotentiallyInterestingDecls;
 
   /// The list of deduced function types that we have not yet read, because
   /// they might contain a deduced return type that refers to a local type
@@ -1506,6 +1492,7 @@ class ASTReader
   getModuleFileLevelDecls(ModuleFile &Mod);
 
 private:
+  bool isConsumerInterestedIn(Decl *D);
   void PassInterestingDeclsToConsumer();
   void PassInterestingDeclToConsumer(Decl *D);
 
@@ -2344,10 +2331,10 @@ class ASTReader
   void ReadDefinedMacros() override;
 
   /// Update an out-of-date identifier.
-  void updateOutOfDateIdentifier(IdentifierInfo &II) override;
+  void updateOutOfDateIdentifier(const IdentifierInfo &II) override;
 
   /// Note that this identifier is up-to-date.
-  void markIdentifierUpToDate(IdentifierInfo *II);
+  void markIdentifierUpToDate(const IdentifierInfo *II);
 
   /// Load all external visible decls in the given DeclContext.
   void completeVisibleDeclsMap(const DeclContext *DC) override;

diff --git a/clang/lib/ARCMigrate/ObjCMT.cpp b/clang/lib/ARCMigrate/ObjCMT.cpp
@@ -1144,7 +1144,7 @@ static bool IsValidIdentifier(ASTContext &Ctx,
     return false;
   std::string NameString = Name;
   NameString[0] = toLowercase(NameString[0]);
-  IdentifierInfo *II = &Ctx.Idents.get(NameString);
+  const IdentifierInfo *II = &Ctx.Idents.get(NameString);
   return II->getTokenID() ==  tok::identifier;
 }
 
@@ -1166,7 +1166,7 @@ bool ObjCMigrateASTConsumer::migrateProperty(ASTContext &Ctx,
   if (OIT_Family != OIT_None)
     return false;
 
-  IdentifierInfo *getterName = GetterSelector.getIdentifierInfoForSlot(0);
+  const IdentifierInfo *getterName = GetterSelector.getIdentifierInfoForSlot(0);
   Selector SetterSelector =
   SelectorTable::constructSetterSelector(PP.getIdentifierTable(),
                                          PP.getSelectorTable(),
@@ -1311,7 +1311,8 @@ void ObjCMigrateASTConsumer::migrateFactoryMethod(ASTContext &Ctx,
   std::string StringLoweredClassName = LoweredClassName.lower();
   LoweredClassName = StringLoweredClassName;
 
-  IdentifierInfo *MethodIdName = OM->getSelector().getIdentifierInfoForSlot(0);
+  const IdentifierInfo *MethodIdName =
+      OM->getSelector().getIdentifierInfoForSlot(0);
   // Handle method with no name at its first selector slot; e.g. + (id):(int)x.
   if (!MethodIdName)
     return;

diff --git a/clang/lib/ARCMigrate/TransAPIUses.cpp b/clang/lib/ARCMigrate/TransAPIUses.cpp
@@ -41,7 +41,7 @@ class APIChecker : public RecursiveASTVisitor<APIChecker> {
     getReturnValueSel = sels.getUnarySelector(&ids.get("getReturnValue"));
     setReturnValueSel = sels.getUnarySelector(&ids.get("setReturnValue"));
 
-    IdentifierInfo *selIds[2];
+    const IdentifierInfo *selIds[2];
     selIds[0] = &ids.get("getArgument");
     selIds[1] = &ids.get("atIndex");
     getArgumentSel = sels.getSelector(2, selIds);

diff --git a/clang/lib/AST/ASTContext.cpp b/clang/lib/AST/ASTContext.cpp
@@ -6929,16 +6929,13 @@ ASTContext::getCanonicalNestedNameSpecifier(NestedNameSpecifier *NNS) const {
     //   typedef typename T::type T1;
     //   typedef typename T1::type T2;
     if (const auto *DNT = T->getAs<DependentNameType>())
-      return NestedNameSpecifier::Create(
-          *this, DNT->getQualifier(),
-          const_cast<IdentifierInfo *>(DNT->getIdentifier()));
+      return NestedNameSpecifier::Create(*this, DNT->getQualifier(),
+                                         DNT->getIdentifier());
     if (const auto *DTST = T->getAs<DependentTemplateSpecializationType>())
-      return NestedNameSpecifier::Create(*this, DTST->getQualifier(), true,
-                                         const_cast<Type *>(T));
+      return NestedNameSpecifier::Create(*this, DTST->getQualifier(), true, T);
 
     // TODO: Set 'Template' parameter to true for other template types.
-    return NestedNameSpecifier::Create(*this, nullptr, false,
-                                       const_cast<Type *>(T));
+    return NestedNameSpecifier::Create(*this, nullptr, false, T);
   }
 
   case NestedNameSpecifier::Global:

diff --git a/clang/lib/AST/ASTImporter.cpp b/clang/lib/AST/ASTImporter.cpp
@@ -8383,8 +8383,8 @@ ASTNodeImporter::VisitCXXPseudoDestructorExpr(CXXPseudoDestructorExpr *E) {
     return std::move(Err);
 
   PseudoDestructorTypeStorage Storage;
-  if (IdentifierInfo *FromII = E->getDestroyedTypeIdentifier()) {
-    IdentifierInfo *ToII = Importer.Import(FromII);
+  if (const IdentifierInfo *FromII = E->getDestroyedTypeIdentifier()) {
+    const IdentifierInfo *ToII = Importer.Import(FromII);
     ExpectedSLoc ToDestroyedTypeLocOrErr = import(E->getDestroyedTypeLoc());
     if (!ToDestroyedTypeLocOrErr)
       return ToDestroyedTypeLocOrErr.takeError();
@@ -10194,7 +10194,7 @@ Expected<Selector> ASTImporter::Import(Selector FromSel) {
   if (FromSel.isNull())
     return Selector{};
 
-  SmallVector<IdentifierInfo *, 4> Idents;
+  SmallVector<const IdentifierInfo *, 4> Idents;
   Idents.push_back(Import(FromSel.getIdentifierInfoForSlot(0)));
   for (unsigned I = 1, N = FromSel.getNumArgs(); I < N; ++I)
     Idents.push_back(Import(FromSel.getIdentifierInfoForSlot(I)));

diff --git a/clang/lib/AST/ComputeDependence.cpp b/clang/lib/AST/ComputeDependence.cpp
@@ -310,6 +310,16 @@ ExprDependence clang::computeDependence(CXXThisExpr *E) {
   // 'this' is type-dependent if the class type of the enclosing
   // member function is dependent (C++ [temp.dep.expr]p2)
   auto D = toExprDependenceForImpliedType(E->getType()->getDependence());
+
+  // If a lambda with an explicit object parameter captures '*this', then
+  // 'this' now refers to the captured copy of lambda, and if the lambda
+  // is type-dependent, so is the object and thus 'this'.
+  //
+  // Note: The standard does not mention this case explicitly, but we need
+  // to do this so we can mark NSDM accesses as dependent.
+  if (E->isCapturedByCopyInLambdaWithExplicitObjectParameter())
+    D |= ExprDependence::Type;
+
   assert(!(D & ExprDependence::UnexpandedPack));
   return D;
 }

diff --git a/clang/lib/AST/Decl.cpp b/clang/lib/AST/Decl.cpp
@@ -2913,10 +2913,10 @@ VarDecl::setInstantiationOfStaticDataMember(VarDecl *VD,
 //===----------------------------------------------------------------------===//
 
 ParmVarDecl *ParmVarDecl::Create(ASTContext &C, DeclContext *DC,
-                                 SourceLocation StartLoc,
-                                 SourceLocation IdLoc, IdentifierInfo *Id,
-                                 QualType T, TypeSourceInfo *TInfo,
-                                 StorageClass S, Expr *DefArg) {
+                                 SourceLocation StartLoc, SourceLocation IdLoc,
+                                 const IdentifierInfo *Id, QualType T,
+                                 TypeSourceInfo *TInfo, StorageClass S,
+                                 Expr *DefArg) {
   return new (C, DC) ParmVarDecl(ParmVar, C, DC, StartLoc, IdLoc, Id, T, TInfo,
                                  S, DefArg);
 }
@@ -4511,7 +4511,7 @@ unsigned FunctionDecl::getODRHash() {
 
 FieldDecl *FieldDecl::Create(const ASTContext &C, DeclContext *DC,
                              SourceLocation StartLoc, SourceLocation IdLoc,
-                             IdentifierInfo *Id, QualType T,
+                             const IdentifierInfo *Id, QualType T,
                              TypeSourceInfo *TInfo, Expr *BW, bool Mutable,
                              InClassInitStyle InitStyle) {
   return new (C, DC) FieldDecl(Decl::Field, DC, StartLoc, IdLoc, Id, T, TInfo,
@@ -5438,7 +5438,7 @@ IndirectFieldDecl::IndirectFieldDecl(ASTContext &C, DeclContext *DC,
 
 IndirectFieldDecl *
 IndirectFieldDecl::Create(ASTContext &C, DeclContext *DC, SourceLocation L,
-                          IdentifierInfo *Id, QualType T,
+                          const IdentifierInfo *Id, QualType T,
                           llvm::MutableArrayRef<NamedDecl *> CH) {
   return new (C, DC) IndirectFieldDecl(C, DC, L, Id, T, CH);
 }
@@ -5461,7 +5461,8 @@ void TypeDecl::anchor() {}
 
 TypedefDecl *TypedefDecl::Create(ASTContext &C, DeclContext *DC,
                                  SourceLocation StartLoc, SourceLocation IdLoc,
-                                 IdentifierInfo *Id, TypeSourceInfo *TInfo) {
+                                 const IdentifierInfo *Id,
+                                 TypeSourceInfo *TInfo) {
   return new (C, DC) TypedefDecl(C, DC, StartLoc, IdLoc, Id, TInfo);
 }
 
@@ -5511,7 +5512,8 @@ TypedefDecl *TypedefDecl::CreateDeserialized(ASTContext &C, unsigned ID) {
 
 TypeAliasDecl *TypeAliasDecl::Create(ASTContext &C, DeclContext *DC,
                                      SourceLocation StartLoc,
-                                     SourceLocation IdLoc, IdentifierInfo *Id,
+                                     SourceLocation IdLoc,
+                                     const IdentifierInfo *Id,
                                      TypeSourceInfo *TInfo) {
   return new (C, DC) TypeAliasDecl(C, DC, StartLoc, IdLoc, Id, TInfo);
 }

diff --git a/clang/lib/AST/DeclObjC.cpp b/clang/lib/AST/DeclObjC.cpp
@@ -66,7 +66,8 @@ void ObjCProtocolList::set(ObjCProtocolDecl* const* InList, unsigned Elts,
 //===----------------------------------------------------------------------===//
 
 ObjCContainerDecl::ObjCContainerDecl(Kind DK, DeclContext *DC,
-                                     IdentifierInfo *Id, SourceLocation nameLoc,
+                                     const IdentifierInfo *Id,
+                                     SourceLocation nameLoc,
                                      SourceLocation atStartLoc)
     : NamedDecl(DK, DC, nameLoc, Id), DeclContext(DK) {
   setAtStartLoc(atStartLoc);
@@ -378,10 +379,8 @@ SourceLocation ObjCInterfaceDecl::getSuperClassLoc() const {
 /// FindPropertyVisibleInPrimaryClass - Finds declaration of the property
 /// with name 'PropertyId' in the primary class; including those in protocols
 /// (direct or indirect) used by the primary class.
-ObjCPropertyDecl *
-ObjCInterfaceDecl::FindPropertyVisibleInPrimaryClass(
-                       IdentifierInfo *PropertyId,
-                       ObjCPropertyQueryKind QueryKind) const {
+ObjCPropertyDecl *ObjCInterfaceDecl::FindPropertyVisibleInPrimaryClass(
+    const IdentifierInfo *PropertyId, ObjCPropertyQueryKind QueryKind) const {
   // FIXME: Should make sure no callers ever do this.
   if (!hasDefinition())
     return nullptr;
@@ -1539,14 +1538,10 @@ void ObjCTypeParamList::gatherDefaultTypeArgs(
 // ObjCInterfaceDecl
 //===----------------------------------------------------------------------===//
 
-ObjCInterfaceDecl *ObjCInterfaceDecl::Create(const ASTContext &C,
-                                             DeclContext *DC,
-                                             SourceLocation atLoc,
-                                             IdentifierInfo *Id,
-                                             ObjCTypeParamList *typeParamList,
-                                             ObjCInterfaceDecl *PrevDecl,
-                                             SourceLocation ClassLoc,
-                                             bool isInternal){
+ObjCInterfaceDecl *ObjCInterfaceDecl::Create(
+    const ASTContext &C, DeclContext *DC, SourceLocation atLoc,
+    const IdentifierInfo *Id, ObjCTypeParamList *typeParamList,
+    ObjCInterfaceDecl *PrevDecl, SourceLocation ClassLoc, bool isInternal) {
   auto *Result = new (C, DC)
       ObjCInterfaceDecl(C, DC, atLoc, Id, typeParamList, ClassLoc, PrevDecl,
                         isInternal);
@@ -1564,12 +1559,10 @@ ObjCInterfaceDecl *ObjCInterfaceDecl::CreateDeserialized(const ASTContext &C,
   return Result;
 }
 
-ObjCInterfaceDecl::ObjCInterfaceDecl(const ASTContext &C, DeclContext *DC,
-                                     SourceLocation AtLoc, IdentifierInfo *Id,
-                                     ObjCTypeParamList *typeParamList,
-                                     SourceLocation CLoc,
-                                     ObjCInterfaceDecl *PrevDecl,
-                                     bool IsInternal)
+ObjCInterfaceDecl::ObjCInterfaceDecl(
+    const ASTContext &C, DeclContext *DC, SourceLocation AtLoc,
+    const IdentifierInfo *Id, ObjCTypeParamList *typeParamList,
+    SourceLocation CLoc, ObjCInterfaceDecl *PrevDecl, bool IsInternal)
     : ObjCContainerDecl(ObjCInterface, DC, Id, CLoc, AtLoc),
       redeclarable_base(C) {
   setPreviousDecl(PrevDecl);
@@ -1751,8 +1744,8 @@ ObjCIvarDecl *ObjCInterfaceDecl::all_declared_ivar_begin() {
 /// categories for this class and returns it. Name of the category is passed
 /// in 'CategoryId'. If category not found, return 0;
 ///
-ObjCCategoryDecl *
-ObjCInterfaceDecl::FindCategoryDeclaration(IdentifierInfo *CategoryId) const {
+ObjCCategoryDecl *ObjCInterfaceDecl::FindCategoryDeclaration(
+    const IdentifierInfo *CategoryId) const {
   // FIXME: Should make sure no callers ever do this.
   if (!hasDefinition())
     return nullptr;
@@ -1838,10 +1831,10 @@ void ObjCIvarDecl::anchor() {}
 
 ObjCIvarDecl *ObjCIvarDecl::Create(ASTContext &C, ObjCContainerDecl *DC,
                                    SourceLocation StartLoc,
-                                   SourceLocation IdLoc, IdentifierInfo *Id,
-                                   QualType T, TypeSourceInfo *TInfo,
-                                   AccessControl ac, Expr *BW,
-                                   bool synthesized) {
+                                   SourceLocation IdLoc,
+                                   const IdentifierInfo *Id, QualType T,
+                                   TypeSourceInfo *TInfo, AccessControl ac,
+                                   Expr *BW, bool synthesized) {
   if (DC) {
     // Ivar's can only appear in interfaces, implementations (via synthesized
     // properties), and class extensions (via direct declaration, or synthesized
@@ -2120,28 +2113,23 @@ void ObjCProtocolDecl::setHasODRHash(bool HasHash) {
 
 void ObjCCategoryDecl::anchor() {}
 
-ObjCCategoryDecl::ObjCCategoryDecl(DeclContext *DC, SourceLocation AtLoc,
-                                   SourceLocation ClassNameLoc,
-                                   SourceLocation CategoryNameLoc,
-                                   IdentifierInfo *Id, ObjCInterfaceDecl *IDecl,
-                                   ObjCTypeParamList *typeParamList,
-                                   SourceLocation IvarLBraceLoc,
-                                   SourceLocation IvarRBraceLoc)
+ObjCCategoryDecl::ObjCCategoryDecl(
+    DeclContext *DC, SourceLocation AtLoc, SourceLocation ClassNameLoc,
+    SourceLocation CategoryNameLoc, const IdentifierInfo *Id,
+    ObjCInterfaceDecl *IDecl, ObjCTypeParamList *typeParamList,
+    SourceLocation IvarLBraceLoc, SourceLocation IvarRBraceLoc)
     : ObjCContainerDecl(ObjCCategory, DC, Id, ClassNameLoc, AtLoc),
       ClassInterface(IDecl), CategoryNameLoc(CategoryNameLoc),
       IvarLBraceLoc(IvarLBraceLoc), IvarRBraceLoc(IvarRBraceLoc) {
   setTypeParamList(typeParamList);
 }
 
-ObjCCategoryDecl *ObjCCategoryDecl::Create(ASTContext &C, DeclContext *DC,
-                                           SourceLocation AtLoc,
-                                           SourceLocation ClassNameLoc,
-                                           SourceLocation CategoryNameLoc,
-                                           IdentifierInfo *Id,
-                                           ObjCInterfaceDecl *IDecl,
-                                           ObjCTypeParamList *typeParamList,
-                                           SourceLocation IvarLBraceLoc,
-                                           SourceLocation IvarRBraceLoc) {
+ObjCCategoryDecl *ObjCCategoryDecl::Create(
+    ASTContext &C, DeclContext *DC, SourceLocation AtLoc,
+    SourceLocation ClassNameLoc, SourceLocation CategoryNameLoc,
+    const IdentifierInfo *Id, ObjCInterfaceDecl *IDecl,
+    ObjCTypeParamList *typeParamList, SourceLocation IvarLBraceLoc,
+    SourceLocation IvarRBraceLoc) {
   auto *CatDecl =
       new (C, DC) ObjCCategoryDecl(DC, AtLoc, ClassNameLoc, CategoryNameLoc, Id,
                                    IDecl, typeParamList, IvarLBraceLoc,
@@ -2190,13 +2178,10 @@ void ObjCCategoryDecl::setTypeParamList(ObjCTypeParamList *TPL) {
 
 void ObjCCategoryImplDecl::anchor() {}
 
-ObjCCategoryImplDecl *
-ObjCCategoryImplDecl::Create(ASTContext &C, DeclContext *DC,
-                             IdentifierInfo *Id,
-                             ObjCInterfaceDecl *ClassInterface,
-                             SourceLocation nameLoc,
-                             SourceLocation atStartLoc,
-                             SourceLocation CategoryNameLoc) {
+ObjCCategoryImplDecl *ObjCCategoryImplDecl::Create(
+    ASTContext &C, DeclContext *DC, const IdentifierInfo *Id,
+    ObjCInterfaceDecl *ClassInterface, SourceLocation nameLoc,
+    SourceLocation atStartLoc, SourceLocation CategoryNameLoc) {
   if (ClassInterface && ClassInterface->hasDefinition())
     ClassInterface = ClassInterface->getDefinition();
   return new (C, DC) ObjCCategoryImplDecl(DC, Id, ClassInterface, nameLoc,
@@ -2365,14 +2350,11 @@ ObjCCompatibleAliasDecl::CreateDeserialized(ASTContext &C, unsigned ID) {
 
 void ObjCPropertyDecl::anchor() {}
 
-ObjCPropertyDecl *ObjCPropertyDecl::Create(ASTContext &C, DeclContext *DC,
-                                           SourceLocation L,
-                                           IdentifierInfo *Id,
-                                           SourceLocation AtLoc,
-                                           SourceLocation LParenLoc,
-                                           QualType T,
-                                           TypeSourceInfo *TSI,
-                                           PropertyControl propControl) {
+ObjCPropertyDecl *
+ObjCPropertyDecl::Create(ASTContext &C, DeclContext *DC, SourceLocation L,
+                         const IdentifierInfo *Id, SourceLocation AtLoc,
+                         SourceLocation LParenLoc, QualType T,
+                         TypeSourceInfo *TSI, PropertyControl propControl) {
   return new (C, DC) ObjCPropertyDecl(DC, L, Id, AtLoc, LParenLoc, T, TSI,
                                       propControl);
 }

diff --git a/clang/lib/AST/DeclPrinter.cpp b/clang/lib/AST/DeclPrinter.cpp
@@ -21,6 +21,7 @@
 #include "clang/AST/ExprCXX.h"
 #include "clang/AST/PrettyPrinter.h"
 #include "clang/Basic/Module.h"
+#include "clang/Basic/SourceManager.h"
 #include "llvm/Support/raw_ostream.h"
 using namespace clang;
 
@@ -49,18 +50,6 @@ namespace {
 
     void PrintObjCTypeParams(ObjCTypeParamList *Params);
 
-    enum class AttrPrintLoc {
-      None = 0,
-      Left = 1,
-      Right = 2,
-      Any = Left | Right,
-
-      LLVM_MARK_AS_BITMASK_ENUM(/*DefaultValue=*/Any)
-    };
-
-    void prettyPrintAttributes(Decl *D, raw_ostream &out,
-                               AttrPrintLoc loc = AttrPrintLoc::Any);
-
   public:
     DeclPrinter(raw_ostream &Out, const PrintingPolicy &Policy,
                 const ASTContext &Context, unsigned Indentation = 0,
@@ -129,11 +118,10 @@ namespace {
                                 const TemplateParameterList *Params);
     void printTemplateArguments(llvm::ArrayRef<TemplateArgumentLoc> Args,
                                 const TemplateParameterList *Params);
-
-    inline void prettyPrintAttributes(Decl *D) {
-      prettyPrintAttributes(D, Out);
-    }
-
+    enum class AttrPosAsWritten { Default = 0, Left, Right };
+    void
+    prettyPrintAttributes(const Decl *D,
+                          AttrPosAsWritten Pos = AttrPosAsWritten::Default);
     void prettyPrintPragmas(Decl *D);
     void printDeclType(QualType T, StringRef DeclName, bool Pack = false);
   };
@@ -250,87 +238,48 @@ raw_ostream& DeclPrinter::Indent(unsigned Indentation) {
   return Out;
 }
 
-// For CLANG_ATTR_LIST_CanPrintOnLeft macro.
-#include "clang/Basic/AttrLeftSideCanPrintList.inc"
+static DeclPrinter::AttrPosAsWritten getPosAsWritten(const Attr *A,
+                                                     const Decl *D) {
+  SourceLocation ALoc = A->getLoc();
+  SourceLocation DLoc = D->getLocation();
+  const ASTContext &C = D->getASTContext();
+  if (ALoc.isInvalid() || DLoc.isInvalid())
+    return DeclPrinter::AttrPosAsWritten::Left;
 
-// For CLANG_ATTR_LIST_PrintOnLeft macro.
-#include "clang/Basic/AttrLeftSideMustPrintList.inc"
+  if (C.getSourceManager().isBeforeInTranslationUnit(ALoc, DLoc))
+    return DeclPrinter::AttrPosAsWritten::Left;
 
-static bool canPrintOnLeftSide(attr::Kind kind) {
-#ifdef CLANG_ATTR_LIST_CanPrintOnLeft
-  switch (kind) {
-  CLANG_ATTR_LIST_CanPrintOnLeft
-    return true;
-  default:
-    return false;
-  }
-#else
-  return false;
-#endif
-}
-
-static bool canPrintOnLeftSide(const Attr *A) {
-  if (A->isStandardAttributeSyntax())
-    return false;
-
-  return canPrintOnLeftSide(A->getKind());
+  return DeclPrinter::AttrPosAsWritten::Right;
 }
 
-static bool mustPrintOnLeftSide(attr::Kind kind) {
-#ifdef CLANG_ATTR_LIST_PrintOnLeft
-  switch (kind) {
-  CLANG_ATTR_LIST_PrintOnLeft
-    return true;
-  default:
-    return false;
-  }
-#else
-  return false;
-#endif
-}
-
-static bool mustPrintOnLeftSide(const Attr *A) {
-  if (A->isDeclspecAttribute())
-    return true;
-
-  return mustPrintOnLeftSide(A->getKind());
-}
-
-void DeclPrinter::prettyPrintAttributes(Decl *D, llvm::raw_ostream &Out,
-                                        AttrPrintLoc Loc) {
+void DeclPrinter::prettyPrintAttributes(const Decl *D,
+                                        AttrPosAsWritten Pos /*=Default*/) {
   if (Policy.PolishForDeclaration)
     return;
 
   if (D->hasAttrs()) {
-    AttrVec &Attrs = D->getAttrs();
+    const AttrVec &Attrs = D->getAttrs();
     for (auto *A : Attrs) {
       if (A->isInherited() || A->isImplicit())
         continue;
-
-      AttrPrintLoc AttrLoc = AttrPrintLoc::Right;
-      if (mustPrintOnLeftSide(A)) {
-        // If we must always print on left side (e.g. declspec), then mark as
-        // so.
-        AttrLoc = AttrPrintLoc::Left;
-      } else if (canPrintOnLeftSide(A)) {
-        // For functions with body defined we print the attributes on the left
-        // side so that GCC accept our dumps as well.
-        if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D);
-            FD && FD->isThisDeclarationADefinition())
-          // In case Decl is a function with a body, then attrs should be print
-          // on the left side.
-          AttrLoc = AttrPrintLoc::Left;
-
-          // In case it is a variable declaration with a ctor, then allow
-          // printing on the left side for readbility.
-        else if (const VarDecl *VD = dyn_cast<VarDecl>(D);
-                   VD && VD->getInit() &&
-                   VD->getInitStyle() == VarDecl::CallInit)
-          AttrLoc = AttrPrintLoc::Left;
+      switch (A->getKind()) {
+#define ATTR(X)
+#define PRAGMA_SPELLING_ATTR(X) case attr::X:
+#include "clang/Basic/AttrList.inc"
+        break;
+      default:
+        AttrPosAsWritten APos = getPosAsWritten(A, D);
+        assert(APos != AttrPosAsWritten::Default &&
+               "Default not a valid for an attribute location");
+        if (Pos == AttrPosAsWritten::Default || Pos == APos) {
+          if (Pos != AttrPosAsWritten::Left)
+            Out << ' ';
+          A->printPretty(Out, Policy);
+          if (Pos == AttrPosAsWritten::Left)
+            Out << ' ';
+        }
+        break;
       }
-      // Only print the side matches the user requested.
-      if ((Loc & AttrLoc) != AttrPrintLoc::None)
-        A->printPretty(Out, Policy);
     }
   }
 }
@@ -691,8 +640,10 @@ static void MaybePrintTagKeywordIfSupressingScopes(PrintingPolicy &Policy,
 
 void DeclPrinter::VisitFunctionDecl(FunctionDecl *D) {
   if (!D->getDescribedFunctionTemplate() &&
-      !D->isFunctionTemplateSpecialization())
+      !D->isFunctionTemplateSpecialization()) {
     prettyPrintPragmas(D);
+    prettyPrintAttributes(D, AttrPosAsWritten::Left);
+  }
 
   if (D->isFunctionTemplateSpecialization())
     Out << "template<> ";
@@ -702,22 +653,6 @@ void DeclPrinter::VisitFunctionDecl(FunctionDecl *D) {
       printTemplateParameters(D->getTemplateParameterList(I));
   }
 
-  std::string LeftsideAttrs;
-  llvm::raw_string_ostream LSAS(LeftsideAttrs);
-
-  prettyPrintAttributes(D, LSAS, AttrPrintLoc::Left);
-
-  // prettyPrintAttributes print a space on left side of the attribute.
-  if (LeftsideAttrs[0] == ' ') {
-    // Skip the space prettyPrintAttributes generated.
-    LeftsideAttrs.erase(0, LeftsideAttrs.find_first_not_of(' '));
-
-    // Add a single space between the attribute and the Decl name.
-    LSAS << ' ';
-  }
-
-  Out << LeftsideAttrs;
-
   CXXConstructorDecl *CDecl = dyn_cast<CXXConstructorDecl>(D);
   CXXConversionDecl *ConversionDecl = dyn_cast<CXXConversionDecl>(D);
   CXXDeductionGuideDecl *GuideDecl = dyn_cast<CXXDeductionGuideDecl>(D);
@@ -883,7 +818,7 @@ void DeclPrinter::VisitFunctionDecl(FunctionDecl *D) {
     Ty.print(Out, Policy, Proto);
   }
 
-  prettyPrintAttributes(D, Out, AttrPrintLoc::Right);
+  prettyPrintAttributes(D, AttrPosAsWritten::Right);
 
   if (D->isPureVirtual())
     Out << " = 0";
@@ -976,27 +911,12 @@ void DeclPrinter::VisitLabelDecl(LabelDecl *D) {
 void DeclPrinter::VisitVarDecl(VarDecl *D) {
   prettyPrintPragmas(D);
 
+  prettyPrintAttributes(D, AttrPosAsWritten::Left);
+
   if (const auto *Param = dyn_cast<ParmVarDecl>(D);
       Param && Param->isExplicitObjectParameter())
     Out << "this ";
 
-  std::string LeftSide;
-  llvm::raw_string_ostream LeftSideStream(LeftSide);
-
-  // Print attributes that should be placed on the left, such as __declspec.
-  prettyPrintAttributes(D, LeftSideStream, AttrPrintLoc::Left);
-
-  // prettyPrintAttributes print a space on left side of the attribute.
-  if (LeftSide[0] == ' ') {
-    // Skip the space prettyPrintAttributes generated.
-    LeftSide.erase(0, LeftSide.find_first_not_of(' '));
-
-    // Add a single space between the attribute and the Decl name.
-    LeftSideStream << ' ';
-  }
-
-  Out << LeftSide;
-
   QualType T = D->getTypeSourceInfo()
     ? D->getTypeSourceInfo()->getType()
     : D->getASTContext().getUnqualifiedObjCPointerType(D->getType());
@@ -1029,21 +949,16 @@ void DeclPrinter::VisitVarDecl(VarDecl *D) {
     }
   }
 
-  StringRef Name;
-
-  Name = (isa<ParmVarDecl>(D) && Policy.CleanUglifiedParameters &&
-          D->getIdentifier())
-             ? D->getIdentifier()->deuglifiedName()
-             : D->getName();
-
   if (!Policy.SuppressTagKeyword && Policy.SuppressScope &&
       !Policy.SuppressUnwrittenScope)
     MaybePrintTagKeywordIfSupressingScopes(Policy, T, Out);
-  printDeclType(T, Name);
 
-  // Print the attributes that should be placed right before the end of the
-  // decl.
-  prettyPrintAttributes(D, Out, AttrPrintLoc::Right);
+  printDeclType(T, (isa<ParmVarDecl>(D) && Policy.CleanUglifiedParameters &&
+                    D->getIdentifier())
+                       ? D->getIdentifier()->deuglifiedName()
+                       : D->getName());
+
+  prettyPrintAttributes(D, AttrPosAsWritten::Right);
 
   Expr *Init = D->getInit();
   if (!Policy.SuppressInitializers && Init) {

diff --git a/clang/lib/AST/DeclTemplate.cpp b/clang/lib/AST/DeclTemplate.cpp
@@ -715,7 +715,7 @@ void TemplateTypeParmDecl::setTypeConstraint(
 
 NonTypeTemplateParmDecl::NonTypeTemplateParmDecl(
     DeclContext *DC, SourceLocation StartLoc, SourceLocation IdLoc, unsigned D,
-    unsigned P, IdentifierInfo *Id, QualType T, TypeSourceInfo *TInfo,
+    unsigned P, const IdentifierInfo *Id, QualType T, TypeSourceInfo *TInfo,
     ArrayRef<QualType> ExpandedTypes, ArrayRef<TypeSourceInfo *> ExpandedTInfos)
     : DeclaratorDecl(NonTypeTemplateParm, DC, IdLoc, Id, T, TInfo, StartLoc),
       TemplateParmPosition(D, P), ParameterPack(true),
@@ -730,12 +730,10 @@ NonTypeTemplateParmDecl::NonTypeTemplateParmDecl(
   }
 }
 
-NonTypeTemplateParmDecl *
-NonTypeTemplateParmDecl::Create(const ASTContext &C, DeclContext *DC,
-                                SourceLocation StartLoc, SourceLocation IdLoc,
-                                unsigned D, unsigned P, IdentifierInfo *Id,
-                                QualType T, bool ParameterPack,
-                                TypeSourceInfo *TInfo) {
+NonTypeTemplateParmDecl *NonTypeTemplateParmDecl::Create(
+    const ASTContext &C, DeclContext *DC, SourceLocation StartLoc,
+    SourceLocation IdLoc, unsigned D, unsigned P, const IdentifierInfo *Id,
+    QualType T, bool ParameterPack, TypeSourceInfo *TInfo) {
   AutoType *AT =
       C.getLangOpts().CPlusPlus20 ? T->getContainedAutoType() : nullptr;
   return new (C, DC,
@@ -748,7 +746,7 @@ NonTypeTemplateParmDecl::Create(const ASTContext &C, DeclContext *DC,
 
 NonTypeTemplateParmDecl *NonTypeTemplateParmDecl::Create(
     const ASTContext &C, DeclContext *DC, SourceLocation StartLoc,
-    SourceLocation IdLoc, unsigned D, unsigned P, IdentifierInfo *Id,
+    SourceLocation IdLoc, unsigned D, unsigned P, const IdentifierInfo *Id,
     QualType T, TypeSourceInfo *TInfo, ArrayRef<QualType> ExpandedTypes,
     ArrayRef<TypeSourceInfo *> ExpandedTInfos) {
   AutoType *AT = TInfo->getType()->getContainedAutoType();