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);
 
@@ -1581,26 +1581,36 @@ class TemplateTemplateParmDecl final
       DefaultArgStorage<TemplateTemplateParmDecl, TemplateArgumentLoc *>;
   DefArgStorage DefaultArgument;
 
+  /// Whether this template template parameter was declaration with
+  /// the 'typename' keyword.
+  ///
+  /// If false, it was declared with the 'class' keyword.
+  LLVM_PREFERRED_TYPE(bool)
+  unsigned Typename : 1;
+
   /// Whether this parameter is a parameter pack.
-  bool ParameterPack;
+  LLVM_PREFERRED_TYPE(bool)
+  unsigned ParameterPack : 1;
 
   /// Whether this template template parameter is an "expanded"
   /// parameter pack, meaning that it is a pack expansion and we
   /// already know the set of template parameters that expansion expands to.
-  bool ExpandedParameterPack = false;
+  LLVM_PREFERRED_TYPE(bool)
+  unsigned ExpandedParameterPack : 1;
 
   /// The number of parameters in an expanded parameter pack.
   unsigned NumExpandedParams = 0;
 
-  TemplateTemplateParmDecl(DeclContext *DC, SourceLocation L,
-                           unsigned D, unsigned P, bool ParameterPack,
-                           IdentifierInfo *Id, TemplateParameterList *Params)
+  TemplateTemplateParmDecl(DeclContext *DC, SourceLocation L, unsigned D,
+                           unsigned P, bool ParameterPack, IdentifierInfo *Id,
+                           bool Typename, TemplateParameterList *Params)
       : TemplateDecl(TemplateTemplateParm, DC, L, Id, Params),
-        TemplateParmPosition(D, P), ParameterPack(ParameterPack) {}
+        TemplateParmPosition(D, P), Typename(Typename),
+        ParameterPack(ParameterPack), ExpandedParameterPack(false) {}
 
-  TemplateTemplateParmDecl(DeclContext *DC, SourceLocation L,
-                           unsigned D, unsigned P,
-                           IdentifierInfo *Id, TemplateParameterList *Params,
+  TemplateTemplateParmDecl(DeclContext *DC, SourceLocation L, unsigned D,
+                           unsigned P, IdentifierInfo *Id, bool Typename,
+                           TemplateParameterList *Params,
                            ArrayRef<TemplateParameterList *> Expansions);
 
   void anchor() override;
@@ -1613,14 +1623,13 @@ class TemplateTemplateParmDecl final
   static TemplateTemplateParmDecl *Create(const ASTContext &C, DeclContext *DC,
                                           SourceLocation L, unsigned D,
                                           unsigned P, bool ParameterPack,
-                                          IdentifierInfo *Id,
+                                          IdentifierInfo *Id, bool Typename,
                                           TemplateParameterList *Params);
-  static TemplateTemplateParmDecl *Create(const ASTContext &C, DeclContext *DC,
-                                          SourceLocation L, unsigned D,
-                                          unsigned P,
-                                          IdentifierInfo *Id,
-                                          TemplateParameterList *Params,
-                                 ArrayRef<TemplateParameterList *> Expansions);
+  static TemplateTemplateParmDecl *
+  Create(const ASTContext &C, DeclContext *DC, SourceLocation L, unsigned D,
+         unsigned P, IdentifierInfo *Id, bool Typename,
+         TemplateParameterList *Params,
+         ArrayRef<TemplateParameterList *> Expansions);
 
   static TemplateTemplateParmDecl *CreateDeserialized(ASTContext &C,
                                                       unsigned ID);
@@ -1634,6 +1643,14 @@ class TemplateTemplateParmDecl final
   using TemplateParmPosition::setPosition;
   using TemplateParmPosition::getIndex;
 
+  /// Whether this template template parameter was declared with
+  /// the 'typename' keyword.
+  bool wasDeclaredWithTypename() const { return Typename; }
+
+  /// Set whether this template template parameter was declared with
+  /// the 'typename' or 'class' keyword.
+  void setDeclaredWithTypename(bool withTypename) { Typename = withTypename; }
+
   /// Whether this template template parameter is a template
   /// parameter pack.
   ///

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/JSONNodeDumper.h b/clang/include/clang/AST/JSONNodeDumper.h
@@ -310,6 +310,8 @@ class JSONNodeDumper
   void VisitMaterializeTemporaryExpr(const MaterializeTemporaryExpr *MTE);
   void VisitCXXDependentScopeMemberExpr(const CXXDependentScopeMemberExpr *ME);
   void VisitRequiresExpr(const RequiresExpr *RE);
+  void VisitCXXDefaultArgExpr(const CXXDefaultArgExpr *Node);
+  void VisitCXXDefaultInitExpr(const CXXDefaultInitExpr *Node);
 
   void VisitObjCEncodeExpr(const ObjCEncodeExpr *OEE);
   void VisitObjCMessageExpr(const ObjCMessageExpr *OME);

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
@@ -14,6 +14,7 @@
 #ifndef LLVM_CLANG_AST_OPENACCCLAUSE_H
 #define LLVM_CLANG_AST_OPENACCCLAUSE_H
 #include "clang/AST/ASTContext.h"
+#include "clang/AST/StmtIterator.h"
 #include "clang/Basic/OpenACCKinds.h"
 
 namespace clang {
@@ -34,6 +35,17 @@ class OpenACCClause {
 
   static bool classof(const OpenACCClause *) { return true; }
 
+  using child_iterator = StmtIterator;
+  using const_child_iterator = ConstStmtIterator;
+  using child_range = llvm::iterator_range<child_iterator>;
+  using const_child_range = llvm::iterator_range<const_child_iterator>;
+
+  child_range children();
+  const_child_range children() const {
+    auto Children = const_cast<OpenACCClause *>(this)->children();
+    return const_child_range(Children.begin(), Children.end());
+  }
+
   virtual ~OpenACCClause() = default;
 };
 
@@ -49,6 +61,99 @@ class OpenACCClauseWithParams : public OpenACCClause {
 
 public:
   SourceLocation getLParenLoc() const { return LParenLoc; }
+
+  child_range children() {
+    return child_range(child_iterator(), child_iterator());
+  }
+  const_child_range children() const {
+    return const_child_range(const_child_iterator(), const_child_iterator());
+  }
+};
+
+/// 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);
+};
+
+/// Represents one of the handful of classes that has an optional/required
+/// 'condition' expression as an argument.
+class OpenACCClauseWithCondition : public OpenACCClauseWithParams {
+  Expr *ConditionExpr = nullptr;
+
+protected:
+  OpenACCClauseWithCondition(OpenACCClauseKind K, SourceLocation BeginLoc,
+                             SourceLocation LParenLoc, Expr *ConditionExpr,
+                             SourceLocation EndLoc)
+      : OpenACCClauseWithParams(K, BeginLoc, LParenLoc, EndLoc),
+        ConditionExpr(ConditionExpr) {}
+
+public:
+  bool hasConditionExpr() const { return ConditionExpr; }
+  const Expr *getConditionExpr() const { return ConditionExpr; }
+  Expr *getConditionExpr() { return ConditionExpr; }
+
+  child_range children() {
+    if (ConditionExpr)
+      return child_range(reinterpret_cast<Stmt **>(&ConditionExpr),
+                         reinterpret_cast<Stmt **>(&ConditionExpr + 1));
+    return child_range(child_iterator(), child_iterator());
+  }
+
+  const_child_range children() const {
+    if (ConditionExpr)
+      return const_child_range(
+          reinterpret_cast<Stmt *const *>(&ConditionExpr),
+          reinterpret_cast<Stmt *const *>(&ConditionExpr + 1));
+    return const_child_range(const_child_iterator(), const_child_iterator());
+  }
+};
+
+/// An 'if' clause, which has a required condition expression.
+class OpenACCIfClause : public OpenACCClauseWithCondition {
+protected:
+  OpenACCIfClause(SourceLocation BeginLoc, SourceLocation LParenLoc,
+                  Expr *ConditionExpr, SourceLocation EndLoc);
+
+public:
+  static OpenACCIfClause *Create(const ASTContext &C, SourceLocation BeginLoc,
+                                 SourceLocation LParenLoc, Expr *ConditionExpr,
+                                 SourceLocation EndLoc);
+};
+
+/// A 'self' clause, which has an optional condition expression.
+class OpenACCSelfClause : public OpenACCClauseWithCondition {
+  OpenACCSelfClause(SourceLocation BeginLoc, SourceLocation LParenLoc,
+                    Expr *ConditionExpr, SourceLocation EndLoc);
+
+public:
+  static OpenACCSelfClause *Create(const ASTContext &C, SourceLocation BeginLoc,
+                                   SourceLocation LParenLoc,
+                                   Expr *ConditionExpr, SourceLocation EndLoc);
 };
 
 template <class Impl> class OpenACCClauseVisitor {
@@ -65,53 +170,25 @@ template <class Impl> class OpenACCClauseVisitor {
       return;
 
     switch (C->getClauseKind()) {
-    case OpenACCClauseKind::Default:
-    case OpenACCClauseKind::Finalize:
-    case OpenACCClauseKind::IfPresent:
-    case OpenACCClauseKind::Seq:
-    case OpenACCClauseKind::Independent:
-    case OpenACCClauseKind::Auto:
-    case OpenACCClauseKind::Worker:
-    case OpenACCClauseKind::Vector:
-    case OpenACCClauseKind::NoHost:
-    case OpenACCClauseKind::If:
-    case OpenACCClauseKind::Self:
-    case OpenACCClauseKind::Copy:
-    case OpenACCClauseKind::UseDevice:
-    case OpenACCClauseKind::Attach:
-    case OpenACCClauseKind::Delete:
-    case OpenACCClauseKind::Detach:
-    case OpenACCClauseKind::Device:
-    case OpenACCClauseKind::DevicePtr:
-    case OpenACCClauseKind::DeviceResident:
-    case OpenACCClauseKind::FirstPrivate:
-    case OpenACCClauseKind::Host:
-    case OpenACCClauseKind::Link:
-    case OpenACCClauseKind::NoCreate:
-    case OpenACCClauseKind::Present:
-    case OpenACCClauseKind::Private:
-    case OpenACCClauseKind::CopyOut:
-    case OpenACCClauseKind::CopyIn:
-    case OpenACCClauseKind::Create:
-    case OpenACCClauseKind::Reduction:
-    case OpenACCClauseKind::Collapse:
-    case OpenACCClauseKind::Bind:
-    case OpenACCClauseKind::VectorLength:
-    case OpenACCClauseKind::NumGangs:
-    case OpenACCClauseKind::NumWorkers:
-    case OpenACCClauseKind::DeviceNum:
-    case OpenACCClauseKind::DefaultAsync:
-    case OpenACCClauseKind::DeviceType:
-    case OpenACCClauseKind::DType:
-    case OpenACCClauseKind::Async:
-    case OpenACCClauseKind::Tile:
-    case OpenACCClauseKind::Gang:
-    case OpenACCClauseKind::Wait:
-    case OpenACCClauseKind::Invalid:
+#define VISIT_CLAUSE(CLAUSE_NAME)                                              \
+  case OpenACCClauseKind::CLAUSE_NAME:                                         \
+    Visit##CLAUSE_NAME##Clause(*cast<OpenACC##CLAUSE_NAME##Clause>(C));        \
+    return;
+#include "clang/Basic/OpenACCClauses.def"
+
+    default:
       llvm_unreachable("Clause visitor not yet implemented");
     }
     llvm_unreachable("Invalid Clause kind");
   }
+
+#define VISIT_CLAUSE(CLAUSE_NAME)                                              \
+  void Visit##CLAUSE_NAME##Clause(                                             \
+      const OpenACC##CLAUSE_NAME##Clause &Clause) {                            \
+    return getDerived().Visit##CLAUSE_NAME##Clause(Clause);                    \
+  }
+
+#include "clang/Basic/OpenACCClauses.def"
 };
 
 class OpenACCClausePrinter final
@@ -128,6 +205,10 @@ class OpenACCClausePrinter final
     }
   }
   OpenACCClausePrinter(raw_ostream &OS) : OS(OS) {}
+
+#define VISIT_CLAUSE(CLAUSE_NAME)                                              \
+  void Visit##CLAUSE_NAME##Clause(const OpenACC##CLAUSE_NAME##Clause &Clause);
+#include "clang/Basic/OpenACCClauses.def"
 };
 
 } // 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/StmtOpenACC.h b/clang/include/clang/AST/StmtOpenACC.h
@@ -142,9 +142,7 @@ class OpenACCComputeConstruct final
                           Stmt *StructuredBlock)
       : OpenACCAssociatedStmtConstruct(OpenACCComputeConstructClass, K, Start,
                                        End, StructuredBlock) {
-    assert((K == OpenACCDirectiveKind::Parallel ||
-            K == OpenACCDirectiveKind::Serial ||
-            K == OpenACCDirectiveKind::Kernels) &&
+    assert(isOpenACCComputeDirectiveKind(K) &&
            "Only parallel, serial, and kernels constructs should be "
            "represented by this type");
 

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/FlowSensitive/ASTOps.h b/clang/include/clang/Analysis/FlowSensitive/ASTOps.h
@@ -0,0 +1,98 @@
+//===-- ASTOps.h -------------------------------*- C++ -*-===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+//  Operations on AST nodes that are used in flow-sensitive analysis.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CLANG_ANALYSIS_FLOWSENSITIVE_ASTOPS_H
+#define LLVM_CLANG_ANALYSIS_FLOWSENSITIVE_ASTOPS_H
+
+#include "clang/AST/Decl.h"
+#include "clang/AST/Expr.h"
+#include "clang/AST/Type.h"
+#include "clang/Analysis/FlowSensitive/StorageLocation.h"
+#include "llvm/ADT/DenseSet.h"
+#include "llvm/ADT/SetVector.h"
+
+namespace clang {
+namespace dataflow {
+
+/// Skip past nodes that the CFG does not emit. These nodes are invisible to
+/// flow-sensitive analysis, and should be ignored as they will effectively not
+/// exist.
+///
+///   * `ParenExpr` - The CFG takes the operator precedence into account, but
+///   otherwise omits the node afterwards.
+///
+///   * `ExprWithCleanups` - The CFG will generate the appropriate calls to
+///   destructors and then omit the node.
+///
+const Expr &ignoreCFGOmittedNodes(const Expr &E);
+const Stmt &ignoreCFGOmittedNodes(const Stmt &S);
+
+/// A set of `FieldDecl *`. Use `SmallSetVector` to guarantee deterministic
+/// iteration order.
+using FieldSet = llvm::SmallSetVector<const FieldDecl *, 4>;
+
+/// Returns the set of all fields in the type.
+FieldSet getObjectFields(QualType Type);
+
+/// Returns whether `Fields` and `FieldLocs` contain the same fields.
+bool containsSameFields(const FieldSet &Fields,
+                        const RecordStorageLocation::FieldToLoc &FieldLocs);
+
+/// Helper class for initialization of a record with an `InitListExpr`.
+/// `InitListExpr::inits()` contains the initializers for both the base classes
+/// and the fields of the record; this helper class separates these out into two
+/// different lists. In addition, it deals with special cases associated with
+/// unions.
+class RecordInitListHelper {
+public:
+  // `InitList` must have record type.
+  RecordInitListHelper(const InitListExpr *InitList);
+
+  // Base classes with their associated initializer expressions.
+  ArrayRef<std::pair<const CXXBaseSpecifier *, Expr *>> base_inits() const {
+    return BaseInits;
+  }
+
+  // Fields with their associated initializer expressions.
+  ArrayRef<std::pair<const FieldDecl *, Expr *>> field_inits() const {
+    return FieldInits;
+  }
+
+private:
+  SmallVector<std::pair<const CXXBaseSpecifier *, Expr *>> BaseInits;
+  SmallVector<std::pair<const FieldDecl *, Expr *>> FieldInits;
+
+  // We potentially synthesize an `ImplicitValueInitExpr` for unions. It's a
+  // member variable because we store a pointer to it in `FieldInits`.
+  std::optional<ImplicitValueInitExpr> ImplicitValueInitForUnion;
+};
+
+/// A collection of several types of declarations, all referenced from the same
+/// function.
+struct ReferencedDecls {
+  /// Non-static member variables.
+  FieldSet Fields;
+  /// All variables with static storage duration, notably including static
+  /// member variables and static variables declared within a function.
+  llvm::DenseSet<const VarDecl *> Globals;
+  /// Free functions and member functions which are referenced (but not
+  /// necessarily called).
+  llvm::DenseSet<const FunctionDecl *> Functions;
+};
+
+/// Returns declarations that are declared in or referenced from `FD`.
+ReferencedDecls getReferencedDecls(const FunctionDecl &FD);
+
+} // namespace dataflow
+} // namespace clang
+
+#endif // LLVM_CLANG_ANALYSIS_FLOWSENSITIVE_ASTOPS_H
diff --git a/clang/include/clang/Analysis/FlowSensitive/ControlFlowContext.h b/clang/include/clang/Analysis/FlowSensitive/ControlFlowContext.h
diff --git a/clang/include/clang/Analysis/FlowSensitive/DataflowAnalysisContext.h b/clang/include/clang/Analysis/FlowSensitive/DataflowAnalysisContext.h
@@ -18,6 +18,7 @@
 #include "clang/AST/Decl.h"
 #include "clang/AST/Expr.h"
 #include "clang/AST/TypeOrdering.h"
+#include "clang/Analysis/FlowSensitive/ASTOps.h"
 #include "clang/Analysis/FlowSensitive/AdornedCFG.h"
 #include "clang/Analysis/FlowSensitive/Arena.h"
 #include "clang/Analysis/FlowSensitive/Solver.h"
@@ -30,38 +31,11 @@
 #include <cassert>
 #include <memory>
 #include <optional>
-#include <type_traits>
-#include <utility>
-#include <vector>
 
 namespace clang {
 namespace dataflow {
 class Logger;
 
-/// Skip past nodes that the CFG does not emit. These nodes are invisible to
-/// flow-sensitive analysis, and should be ignored as they will effectively not
-/// exist.
-///
-///   * `ParenExpr` - The CFG takes the operator precedence into account, but
-///   otherwise omits the node afterwards.
-///
-///   * `ExprWithCleanups` - The CFG will generate the appropriate calls to
-///   destructors and then omit the node.
-///
-const Expr &ignoreCFGOmittedNodes(const Expr &E);
-const Stmt &ignoreCFGOmittedNodes(const Stmt &S);
-
-/// A set of `FieldDecl *`. Use `SmallSetVector` to guarantee deterministic
-/// iteration order.
-using FieldSet = llvm::SmallSetVector<const FieldDecl *, 4>;
-
-/// Returns the set of all fields in the type.
-FieldSet getObjectFields(QualType Type);
-
-/// Returns whether `Fields` and `FieldLocs` contain the same fields.
-bool containsSameFields(const FieldSet &Fields,
-                        const RecordStorageLocation::FieldToLoc &FieldLocs);
-
 struct ContextSensitiveOptions {
   /// The maximum depth to analyze. A value of zero is equivalent to disabling
   /// context-sensitive analysis entirely.

diff --git a/clang/include/clang/Analysis/FlowSensitive/DataflowEnvironment.h b/clang/include/clang/Analysis/FlowSensitive/DataflowEnvironment.h
@@ -30,6 +30,7 @@
 #include "llvm/ADT/MapVector.h"
 #include "llvm/Support/Compiler.h"
 #include "llvm/Support/ErrorHandling.h"
+#include <memory>
 #include <type_traits>
 #include <utility>
 
@@ -344,17 +345,6 @@ class Environment {
   /// location of the result object to pass in `this`, even though prvalues are
   /// otherwise not associated with storage locations.
   ///
-  /// FIXME: Currently, this simply returns a stable storage location for `E`,
-  /// but this doesn't do the right thing in scenarios like the following:
-  /// ```
-  /// MyClass c = some_condition()? MyClass(foo) : MyClass(bar);
-  /// ```
-  /// Here, `MyClass(foo)` and `MyClass(bar)` will have two different storage
-  /// locations, when in fact their storage locations should be the same.
-  /// Eventually, we want to propagate storage locations from result objects
-  /// down to the prvalues that initialize them, similar to the way that this is
-  /// done in Clang's CodeGen.
-  ///
   /// Requirements:
   ///  `E` must be a prvalue of record type.
   RecordStorageLocation &
@@ -462,7 +452,13 @@ class Environment {
   /// Initializes the fields (including synthetic fields) of `Loc` with values,
   /// unless values of the field type are not supported or we hit one of the
   /// limits at which we stop producing values.
-  void initializeFieldsWithValues(RecordStorageLocation &Loc);
+  /// If `Type` is provided, initializes only those fields that are modeled for
+  /// `Type`; this is intended for use in cases where `Loc` is a derived type
+  /// and we only want to initialize the fields of a base type.
+  void initializeFieldsWithValues(RecordStorageLocation &Loc, QualType Type);
+  void initializeFieldsWithValues(RecordStorageLocation &Loc) {
+    initializeFieldsWithValues(Loc, Loc.getType());
+  }
 
   /// Assigns `Val` as the value of `Loc` in the environment.
   void setValue(const StorageLocation &Loc, Value &Val);
@@ -653,6 +649,9 @@ class Environment {
   LLVM_DUMP_METHOD void dump(raw_ostream &OS) const;
 
 private:
+  using PrValueToResultObject =
+      llvm::DenseMap<const Expr *, RecordStorageLocation *>;
+
   // The copy-constructor is for use in fork() only.
   Environment(const Environment &) = default;
 
@@ -682,8 +681,10 @@ class Environment {
   /// Initializes the fields (including synthetic fields) of `Loc` with values,
   /// unless values of the field type are not supported or we hit one of the
   /// limits at which we stop producing values (controlled by `Visited`,
-  /// `Depth`, and `CreatedValuesCount`).
-  void initializeFieldsWithValues(RecordStorageLocation &Loc,
+  /// `Depth`, and `CreatedValuesCount`). If `Type` is different from
+  /// `Loc.getType()`, initializes only those fields that are modeled for
+  /// `Type`.
+  void initializeFieldsWithValues(RecordStorageLocation &Loc, QualType Type,
                                   llvm::DenseSet<QualType> &Visited, int Depth,
                                   int &CreatedValuesCount);
 
@@ -702,22 +703,45 @@ class Environment {
   /// and functions referenced in `FuncDecl`. `FuncDecl` must have a body.
   void initFieldsGlobalsAndFuncs(const FunctionDecl *FuncDecl);
 
+  static PrValueToResultObject
+  buildResultObjectMap(DataflowAnalysisContext *DACtx,
+                       const FunctionDecl *FuncDecl,
+                       RecordStorageLocation *ThisPointeeLoc,
+                       RecordStorageLocation *LocForRecordReturnVal);
+
   // `DACtx` is not null and not owned by this object.
   DataflowAnalysisContext *DACtx;
 
-  // FIXME: move the fields `CallStack`, `ReturnVal`, `ReturnLoc` and
-  // `ThisPointeeLoc` into a separate call-context object, shared between
-  // environments in the same call.
+  // FIXME: move the fields `CallStack`, `ResultObjectMap`, `ReturnVal`,
+  // `ReturnLoc` and `ThisPointeeLoc` into a separate call-context object,
+  // shared between environments in the same call.
   // https://github.com/llvm/llvm-project/issues/59005
 
   // `DeclContext` of the block being analysed if provided.
   std::vector<const DeclContext *> CallStack;
 
-  // Value returned by the function (if it has non-reference return type).
+  // Maps from prvalues of record type to their result objects. Shared between
+  // all environments for the same function.
+  // FIXME: It's somewhat unsatisfactory that we have to use a `shared_ptr`
+  // here, though the cost is acceptable: The overhead of a `shared_ptr` is
+  // incurred when it is copied, and this happens only relatively rarely (when
+  // we fork the environment). The need for a `shared_ptr` will go away once we
+  // introduce a shared call-context object (see above).
+  std::shared_ptr<PrValueToResultObject> ResultObjectMap;
+
+  // The following three member variables handle various different types of
+  // return values.
+  // - If the return type is not a reference and not a record: Value returned
+  //   by the function.
   Value *ReturnVal = nullptr;
-  // Storage location of the reference returned by the function (if it has
-  // reference return type).
+  // - If the return type is a reference: Storage location of the reference
+  //   returned by the function.
   StorageLocation *ReturnLoc = nullptr;
+  // - If the return type is a record or the function being analyzed is a
+  //   constructor: Storage location into which the return value should be
+  //   constructed.
+  RecordStorageLocation *LocForRecordReturnVal = nullptr;
+
   // The storage location of the `this` pointee. Should only be null if the
   // function being analyzed is only a function and not a method.
   RecordStorageLocation *ThisPointeeLoc = nullptr;
@@ -751,42 +775,6 @@ RecordStorageLocation *getImplicitObjectLocation(const CXXMemberCallExpr &MCE,
 RecordStorageLocation *getBaseObjectLocation(const MemberExpr &ME,
                                              const Environment &Env);
 
-/// Returns the fields of a `RecordDecl` that are initialized by an
-/// `InitListExpr`, in the order in which they appear in
-/// `InitListExpr::inits()`.
-/// `Init->getType()` must be a record type.
-std::vector<const FieldDecl *>
-getFieldsForInitListExpr(const InitListExpr *InitList);
-
-/// Helper class for initialization of a record with an `InitListExpr`.
-/// `InitListExpr::inits()` contains the initializers for both the base classes
-/// and the fields of the record; this helper class separates these out into two
-/// different lists. In addition, it deals with special cases associated with
-/// unions.
-class RecordInitListHelper {
-public:
-  // `InitList` must have record type.
-  RecordInitListHelper(const InitListExpr *InitList);
-
-  // Base classes with their associated initializer expressions.
-  ArrayRef<std::pair<const CXXBaseSpecifier *, Expr *>> base_inits() const {
-    return BaseInits;
-  }
-
-  // Fields with their associated initializer expressions.
-  ArrayRef<std::pair<const FieldDecl *, Expr *>> field_inits() const {
-    return FieldInits;
-  }
-
-private:
-  SmallVector<std::pair<const CXXBaseSpecifier *, Expr *>> BaseInits;
-  SmallVector<std::pair<const FieldDecl *, Expr *>> FieldInits;
-
-  // We potentially synthesize an `ImplicitValueInitExpr` for unions. It's a
-  // member variable because we store a pointer to it in `FieldInits`.
-  std::optional<ImplicitValueInitExpr> ImplicitValueInitForUnion;
-};
-
 /// Associates a new `RecordValue` with `Loc` and returns the new value.
 RecordValue &refreshRecordValue(RecordStorageLocation &Loc, Environment &Env);
 

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/AttrDocs.td b/clang/include/clang/Basic/AttrDocs.td
@@ -1604,27 +1604,40 @@ specifies availability for the current target platform, the availability
 attributes are ignored. Supported platforms are:
 
 ``ios``
-  Apple's iOS operating system. The minimum deployment target is specified by
-  the ``-mios-version-min=*version*`` or ``-miphoneos-version-min=*version*``
-  command-line arguments.
+  Apple's iOS operating system. The minimum deployment target is specified
+  as part of the ``-target *arch*-apple-ios*version*`` command line argument.
+  Alternatively, it can be specified by the ``-mtargetos=ios*version*``
+  command-line argument.
 
 ``macos``
-  Apple's macOS operating system. The minimum deployment target is
-  specified by the ``-mmacosx-version-min=*version*`` command-line argument.
-  ``macosx`` is supported for backward-compatibility reasons, but it is
-  deprecated.
+  Apple's macOS operating system. The minimum deployment target is specified
+  as part of the ``-target *arch*-apple-macos*version*`` command line argument.
+  Alternatively, it can be specified by the ``-mtargetos=macos*version*``
+  command-line argument. ``macosx`` is supported for
+  backward-compatibility reasons, but it is deprecated.
 
 ``tvos``
-  Apple's tvOS operating system. The minimum deployment target is specified by
-  the ``-mtvos-version-min=*version*`` command-line argument.
+  Apple's tvOS operating system. The minimum deployment target is specified
+  as part of the ``-target *arch*-apple-tvos*version*`` command line argument.
+  Alternatively, it can be specified by the ``-mtargetos=tvos*version*``
+  command-line argument.
 
 ``watchos``
-  Apple's watchOS operating system. The minimum deployment target is specified by
-  the ``-mwatchos-version-min=*version*`` command-line argument.
+  Apple's watchOS operating system. The minimum deployment target is specified
+  as part of the ``-target *arch*-apple-watchos*version*`` command line argument.
+  Alternatively, it can be specified by the ``-mtargetos=watchos*version*``
+  command-line argument.
+
+``visionos``
+  Apple's visionOS operating system. The minimum deployment target is specified
+  as part of the ``-target *arch*-apple-visionos*version*`` command line argument.
+  Alternatively, it can be specified by the ``-mtargetos=visionos*version*``
+  command-line argument.
 
 ``driverkit``
   Apple's DriverKit userspace kernel extensions. The minimum deployment target
-  is specified as part of the triple.
+  is specified as part of the ``-target *arch*-apple-driverkit*version*``
+  command line argument.
 
 A declaration can typically be used even when deploying back to a platform
 version prior to when the declaration was introduced. When this happens, the
@@ -7509,7 +7522,7 @@ means that it can e.g no longer be part of an initializer expression.
 
       /* This may print something else than "6 * 7 = 42",
          if there is a non-weak definition of "ANSWER" in
-	 an object linked in */
+         an object linked in */
       printf("6 * 7 = %d\n", ANSWER);
 
       return 0;

diff --git a/clang/include/clang/Basic/BuiltinsAMDGPU.def b/clang/include/clang/Basic/BuiltinsAMDGPU.def
@@ -61,6 +61,7 @@ BUILTIN(__builtin_amdgcn_s_waitcnt, "vIi", "n")
 BUILTIN(__builtin_amdgcn_s_sendmsg, "vIiUi", "n")
 BUILTIN(__builtin_amdgcn_s_sendmsghalt, "vIiUi", "n")
 BUILTIN(__builtin_amdgcn_s_barrier, "v", "n")
+BUILTIN(__builtin_amdgcn_s_ttracedata, "vi", "n")
 BUILTIN(__builtin_amdgcn_wave_barrier, "v", "n")
 BUILTIN(__builtin_amdgcn_sched_barrier, "vIi", "n")
 BUILTIN(__builtin_amdgcn_sched_group_barrier, "vIiIiIi", "n")
@@ -267,6 +268,7 @@ TARGET_BUILTIN(__builtin_amdgcn_dot4_f32_bf8_bf8, "fUiUif", "nc", "dot11-insts")
 TARGET_BUILTIN(__builtin_amdgcn_permlane16, "UiUiUiUiUiIbIb", "nc", "gfx10-insts")
 TARGET_BUILTIN(__builtin_amdgcn_permlanex16, "UiUiUiUiUiIbIb", "nc", "gfx10-insts")
 TARGET_BUILTIN(__builtin_amdgcn_mov_dpp8, "UiUiIUi", "nc", "gfx10-insts")
+TARGET_BUILTIN(__builtin_amdgcn_s_ttracedata_imm, "vIs", "n", "gfx10-insts")
 
 //===----------------------------------------------------------------------===//
 // Raytracing builtins.

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/Cuda.h b/clang/include/clang/Basic/Cuda.h
@@ -53,10 +53,12 @@ CudaVersion CudaStringToVersion(const llvm::Twine &S);
 enum class CudaArch {
   UNUSED,
   UNKNOWN,
+  // TODO: Deprecate and remove GPU architectures older than sm_52.
   SM_20,
   SM_21,
   SM_30,
-  SM_32,
+  // This has a name conflict with sys/mac.h on AIX, rename it as a workaround.
+  SM_32_,
   SM_35,
   SM_37,
   SM_50,
@@ -126,6 +128,14 @@ enum class CudaArch {
   HIPDefault = CudaArch::GFX906,
 };
 
+enum class CUDAFunctionTarget {
+  Device,
+  Global,
+  Host,
+  HostDevice,
+  InvalidTarget
+};
+
 static inline bool IsNVIDIAGpuArch(CudaArch A) {
   return A >= CudaArch::SM_20 && A < CudaArch::GFX600;
 }

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/DiagnosticInstallAPIKinds.td b/clang/include/clang/Basic/DiagnosticInstallAPIKinds.td
@@ -20,6 +20,10 @@ def warn_no_such_excluded_header_file : Warning<"no such excluded %select{public
 def warn_glob_did_not_match: Warning<"glob '%0' did not match any header file">, InGroup<InstallAPIViolation>;
 def err_no_such_umbrella_header_file : Error<"%select{public|private|project}1 umbrella header file not found in input: '%0'">;
 def err_cannot_find_reexport : Error<"cannot find re-exported %select{framework|library}0: '%1'">;
+def err_no_matching_target : Error<"no matching target found for target variant '%0'">;
+def err_unsupported_vendor : Error<"vendor '%0' is not supported: '%1'">;
+def err_unsupported_environment : Error<"environment '%0' is not supported: '%1'">;
+def err_unsupported_os : Error<"os '%0' is not supported: '%1'">;
 } // end of command line category.
 
 let CategoryName = "Verification" in {

diff --git a/clang/include/clang/Basic/DiagnosticParseKinds.td b/clang/include/clang/Basic/DiagnosticParseKinds.td
@@ -941,6 +941,12 @@ def warn_cxx98_compat_defaulted_deleted_function : Warning<
   "%select{defaulted|deleted}0 function definitions are incompatible with C++98">,
   InGroup<CXX98Compat>, DefaultIgnore;
 
+def ext_delete_with_message : ExtWarn<
+  "'= delete' with a message is a C++2c extension">, InGroup<CXX26>;
+def warn_cxx23_delete_with_message : Warning<
+  "'= delete' with a message is incompatible with C++ standards before C++2c">,
+  DefaultIgnore, InGroup<CXXPre26Compat>;
+
 // C++11 default member initialization
 def ext_nonstatic_member_init : ExtWarn<
   "default member initializer for non-static data member is a C++11 "

diff --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td b/clang/include/clang/Basic/DiagnosticSemaKinds.td
@@ -2402,10 +2402,6 @@ def err_selected_explicit_constructor : Error<
 def note_explicit_ctor_deduction_guide_here : Note<
   "explicit %select{constructor|deduction guide}0 declared here">;
 
-// C++11 decltype
-def err_decltype_in_declarator : Error<
-    "'decltype' cannot be used to name a declaration">;
-
 // C++11 auto
 def warn_cxx98_compat_auto_type_specifier : Warning<
   "'auto' type specifier is incompatible with C++98">,
@@ -3755,6 +3751,16 @@ 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<
@@ -4677,11 +4683,10 @@ def err_ovl_no_viable_member_function_in_call : Error<
   "no matching member function for call to %0">;
 def err_ovl_ambiguous_call : Error<
   "call to %0 is ambiguous">;
-def err_ovl_deleted_call : Error<"call to deleted function %0">;
+def err_ovl_deleted_call : Error<"call to deleted"
+  "%select{| member}0 function %1%select{|: %3}2">;
 def err_ovl_ambiguous_member_call : Error<
   "call to member function %0 is ambiguous">;
-def err_ovl_deleted_member_call : Error<
-  "call to deleted member function %0">;
 def note_ovl_too_many_candidates : Note<
     "remaining %0 candidate%s0 omitted; "
     "pass -fshow-overloads=all to show them">;
@@ -4909,12 +4914,12 @@ def err_ovl_ambiguous_conversion_in_cast : Error<
   "dynamic_cast|C-style cast|functional-style cast|}0 from %1 to %2">;
 def err_ovl_deleted_conversion_in_cast : Error<
   "%select{|static_cast|reinterpret_cast|dynamic_cast|C-style cast|"
-  "functional-style cast|}0 from %1 to %2 uses deleted function">;
+  "functional-style cast|}0 from %1 to %2 uses deleted function%select{|: %4}3">;
 def err_ovl_ambiguous_init : Error<"call to constructor of %0 is ambiguous">;
 def err_ref_init_ambiguous : Error<
   "reference initialization of type %0 with initializer of type %1 is ambiguous">;
 def err_ovl_deleted_init : Error<
-  "call to deleted constructor of %0">;
+  "call to deleted constructor of %0%select{|: %2}1">;
 def err_ovl_deleted_special_init : Error<
   "call to implicitly-deleted %select{default constructor|copy constructor|"
   "move constructor|copy assignment operator|move assignment operator|"
@@ -4940,7 +4945,7 @@ def note_ovl_ambiguous_oper_binary_reversed_candidate : Note<
 def err_ovl_no_viable_oper : Error<"no viable overloaded '%0'">;
 def note_assign_lhs_incomplete : Note<"type %0 is incomplete">;
 def err_ovl_deleted_oper : Error<
-  "overload resolution selected deleted operator '%0'">;
+  "overload resolution selected deleted operator '%0'%select{|: %2}1">;
 def err_ovl_deleted_special_oper : Error<
   "object of type %0 cannot be %select{constructed|copied|moved|assigned|"
   "assigned|destroyed}1 because its %sub{select_special_member_kind}1 is "
@@ -4977,7 +4982,7 @@ def err_ovl_ambiguous_object_call : Error<
 def err_ovl_ambiguous_subscript_call : Error<
   "call to subscript operator of type %0 is ambiguous">;
 def err_ovl_deleted_object_call : Error<
-  "call to deleted function call operator in type %0">;
+  "call to deleted function call operator in type %0%select{|: %2}1">;
 def note_ovl_surrogate_cand : Note<"conversion candidate of type %0">;
 def err_member_call_without_object : Error<
   "call to %select{non-static|explicit}0 member function without an object argument">;
@@ -7142,7 +7147,8 @@ 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">;
@@ -7581,8 +7587,8 @@ def ext_gnu_ptr_func_arith : Extension<
   InGroup<GNUPointerArith>;
 def err_readonly_message_assignment : Error<
   "assigning to 'readonly' return result of an Objective-C message not allowed">;
-def ext_integer_increment_complex : Extension<
-  "ISO C does not support '++'/'--' on complex integer type %0">;
+def ext_increment_complex : Extension<
+  "'%select{--|++}0' on an object of complex type is a Clang extension">;
 def ext_integer_complement_complex : Extension<
   "ISO C does not support '~' for complex conjugation of %0">;
 def err_nosetter_property_assignment : Error<
@@ -8277,7 +8283,7 @@ def err_typecheck_nonviable_condition_incomplete : Error<
   "no viable conversion%diff{ from $ to incomplete type $|}0,1">;
 def err_typecheck_deleted_function : Error<
   "conversion function %diff{from $ to $|between types}0,1 "
-  "invokes a deleted function">;
+  "invokes a deleted function%select{|: %3}2">;
 
 def err_expected_class_or_namespace : Error<"%0 is not a class"
   "%select{ or namespace|, namespace, or enumeration}1">;
@@ -8302,6 +8308,9 @@ def ext_template_after_declarative_nns : ExtWarn<
 def ext_alias_template_in_declarative_nns : ExtWarn<
   "a declarative nested name specifier cannot name an alias template">,
   InGroup<DiagGroup<"alias-template-in-declaration-name">>;
+def err_computed_type_in_declarative_nns  : Error<
+  "a %select{pack indexing|'decltype'}0 specifier cannot be used in "
+  "a declarative nested name specifier">;
 
 def err_no_typeid_with_fno_rtti : Error<
   "use of typeid requires -frtti">;
@@ -8874,7 +8883,7 @@ def err_nontemporal_builtin_must_be_pointer_intfltptr_or_vector : Error<
   "address argument to nontemporal builtin must be a pointer to integer, float, "
   "pointer, or a vector of such types (%0 invalid)">;
 
-def err_deleted_function_use : Error<"attempt to use a deleted function">;
+def err_deleted_function_use : Error<"attempt to use a deleted function%select{|: %1}0">;
 def err_deleted_inherited_ctor_use : Error<
   "constructor inherited by %0 from base class %1 is implicitly deleted">;
 
@@ -12254,11 +12263,19 @@ def err_acc_construct_appertainment
             "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">;
 def note_acc_branch_into_compute_construct
     : Note<"invalid branch into OpenACC Compute Construct">;
 def note_acc_branch_out_of_compute_construct
     : Note<"invalid branch out of OpenACC Compute Construct">;
+def warn_acc_if_self_conflict
+    : Warning<"OpenACC construct 'self' has no effect when an 'if' clause "
+              "evaluates to true">,
+      InGroup<DiagGroup<"openacc-self-if-potential-conflict">>;
 } // end of sema component.
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/OpenACCClauses.def b/clang/include/clang/Basic/OpenACCClauses.def
@@ -0,0 +1,22 @@
+//===-- OpenACCClauses.def - List of implemented OpenACC Clauses -- C++ -*-===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines a list of currently implemented OpenACC Clauses (and
+// eventually, the entire list) in a way that makes generating 'visitor' and
+// other lists easier.
+//
+// The primary macro is a single-argument version taking the name of the Clause
+// as used in Clang source (so `Default` instead of `default`).
+//
+// VISIT_CLAUSE(CLAUSE_NAME)
+
+VISIT_CLAUSE(Default)
+VISIT_CLAUSE(If)
+VISIT_CLAUSE(Self)
+
+#undef VISIT_CLAUSE
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 +138,18 @@ 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);
+}
+
+inline bool isOpenACCComputeDirectiveKind(OpenACCDirectiveKind K) {
+  return K == OpenACCDirectiveKind::Parallel ||
+         K == OpenACCDirectiveKind::Serial ||
+         K == OpenACCDirectiveKind::Kernels;
 }
 
 enum class OpenACCAtomicKind {
@@ -266,7 +272,7 @@ 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 +408,12 @@ 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 +425,30 @@ 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/Basic/TokenKinds.def b/clang/include/clang/Basic/TokenKinds.def
@@ -521,6 +521,7 @@ TYPE_TRAIT_1(__is_union, IsUnion, KEYCXX)
 TYPE_TRAIT_1(__has_unique_object_representations,
              HasUniqueObjectRepresentations, KEYCXX)
 TYPE_TRAIT_2(__is_layout_compatible, IsLayoutCompatible, KEYCXX)
+TYPE_TRAIT_2(__is_pointer_interconvertible_base_of, IsPointerInterconvertibleBaseOf, KEYCXX)
 
 #define TRANSFORM_TYPE_TRAIT_DEF(_, Trait) KEYWORD(__##Trait, KEYCXX)
 #include "clang/Basic/TransformTypeTraits.def"

diff --git a/clang/include/clang/CIR/CMakeLists.txt b/clang/include/clang/CIR/CMakeLists.txt
diff --git a/clang/include/clang/CMakeLists.txt b/clang/include/clang/CMakeLists.txt
@@ -1,5 +1,8 @@
 add_subdirectory(AST)
 add_subdirectory(Basic)
+if(CLANG_ENABLE_CIR)
+  add_subdirectory(CIR)
+endif()
 add_subdirectory(Driver)
 add_subdirectory(Parse)
 add_subdirectory(Sema)

diff --git a/clang/include/clang/CodeGen/CodeGenAction.h b/clang/include/clang/CodeGen/CodeGenAction.h
@@ -57,6 +57,8 @@ class CodeGenAction : public ASTFrontendAction {
   bool loadLinkModules(CompilerInstance &CI);
 
 protected:
+  bool BeginSourceFileAction(CompilerInstance &CI) override;
+
   /// Create a new code generation action.  If the optional \p _VMContext
   /// parameter is supplied, the action uses it without taking ownership,
   /// otherwise it creates a fresh LLVM context and takes ownership.

diff --git a/clang/include/clang/Config/config.h.cmake b/clang/include/clang/Config/config.h.cmake
@@ -83,4 +83,7 @@
 /* Spawn a new process clang.exe for the CC1 tool invocation, when necessary */
 #cmakedefine01 CLANG_SPAWN_CC1
 
+/* Whether CIR is built into Clang */
+#cmakedefine01 CLANG_ENABLE_CIR
+
 #endif
diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td
@@ -1341,7 +1341,8 @@ def hip_link : Flag<["--"], "hip-link">, Group<opencl_Group>,
   HelpText<"Link clang-offload-bundler bundles for HIP">;
 def no_hip_rt: Flag<["-"], "no-hip-rt">, Group<hip_Group>,
   HelpText<"Do not link against HIP runtime libraries">;
-def rocm_path_EQ : Joined<["--"], "rocm-path=">, Group<hip_Group>,
+def rocm_path_EQ : Joined<["--"], "rocm-path=">,
+  Visibility<[FlangOption]>, Group<hip_Group>,
   HelpText<"ROCm installation path, used for finding and automatically linking required bitcode libraries.">;
 def hip_path_EQ : Joined<["--"], "hip-path=">, Group<hip_Group>,
   HelpText<"HIP runtime installation path, used for finding HIP version and adding HIP include path.">;
@@ -1449,7 +1450,7 @@ 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">,
@@ -3035,6 +3036,7 @@ defm prebuilt_implicit_modules : BoolFOption<"prebuilt-implicit-modules",
 
 def fmodule_output_EQ : Joined<["-"], "fmodule-output=">,
   Flags<[NoXarchOption]>, Visibility<[ClangOption, CC1Option]>,
+  MarshallingInfoString<FrontendOpts<"ModuleOutputPath">>,
   HelpText<"Save intermediate module file results when compiling a standard C++ module unit.">;
 def fmodule_output : Flag<["-"], "fmodule-output">, Flags<[NoXarchOption]>,
   Visibility<[ClangOption, CC1Option]>,
@@ -3048,6 +3050,11 @@ defm skip_odr_check_in_gmf : BoolOption<"f", "skip-odr-check-in-gmf",
           "Perform ODR checks for decls in the global module fragment.">>,
   Group<f_Group>;
 
+def modules_reduced_bmi : Flag<["-"], "fexperimental-modules-reduced-bmi">,
+  Group<f_Group>, Visibility<[ClangOption, CC1Option]>,
+  HelpText<"Generate the reduced BMI">,
+  MarshallingInfoFlag<FrontendOpts<"GenReducedBMI">>;
+
 def fmodules_prune_interval : Joined<["-"], "fmodules-prune-interval=">, Group<i_Group>,
   Visibility<[ClangOption, CC1Option]>, MetaVarName<"<seconds>">,
   HelpText<"Specify the interval (in seconds) between attempts to prune the module cache">,
@@ -4912,6 +4919,9 @@ 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,
@@ -5461,21 +5471,23 @@ def rdynamic : Flag<["-"], "rdynamic">, Group<Link_Group>,
   Visibility<[ClangOption, FlangOption]>;
 def resource_dir : Separate<["-"], "resource-dir">,
   Flags<[NoXarchOption, HelpHidden]>,
-  Visibility<[ClangOption, CC1Option, CLOption, DXCOption]>,
+  Visibility<[ClangOption, CC1Option, CLOption, DXCOption, FlangOption, FC1Option]>,
   HelpText<"The directory which holds the compiler resource files">,
   MarshallingInfoString<HeaderSearchOpts<"ResourceDir">>;
 def resource_dir_EQ : Joined<["-"], "resource-dir=">, Flags<[NoXarchOption]>,
-  Visibility<[ClangOption, CLOption, DXCOption]>,
+  Visibility<[ClangOption, CLOption, DXCOption, FlangOption]>,
   Alias<resource_dir>;
 def rpath : Separate<["-"], "rpath">, Flags<[LinkerInput]>, Group<Link_Group>,
   Visibility<[ClangOption, CLOption, DXCOption, FlangOption]>;
 def rtlib_EQ : Joined<["-", "--"], "rtlib=">, Visibility<[ClangOption, CLOption]>,
   HelpText<"Compiler runtime library to use">;
 def frtlib_add_rpath: Flag<["-"], "frtlib-add-rpath">, Flags<[NoArgumentUnused]>,
+  Visibility<[ClangOption, FlangOption]>,
   HelpText<"Add -rpath with architecture-specific resource directory to the linker flags. "
   "When --hip-link is specified, also add -rpath with HIP runtime library directory to the linker flags">;
 def fno_rtlib_add_rpath: Flag<["-"], "fno-rtlib-add-rpath">,
   Flags<[NoArgumentUnused]>,
+  Visibility<[ClangOption, FlangOption]>,
   HelpText<"Do not add -rpath with architecture-specific resource directory to the linker flags. "
   "When --hip-link is specified, do not add -rpath with HIP runtime library directory to the linker flags">;
 def offload_add_rpath: Flag<["--"], "offload-add-rpath">,

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/Frontend/FrontendOptions.h b/clang/include/clang/Frontend/FrontendOptions.h
@@ -404,6 +404,10 @@ class FrontendOptions {
   LLVM_PREFERRED_TYPE(bool)
   unsigned EmitPrettySymbolGraphs : 1;
 
+  /// Whether to generate reduced BMI for C++20 named modules.
+  LLVM_PREFERRED_TYPE(bool)
+  unsigned GenReducedBMI : 1;
+
   CodeCompleteOptions CodeCompleteOpts;
 
   /// Specifies the output format of the AST.
@@ -568,6 +572,9 @@ class FrontendOptions {
   /// Path which stores the output files for -ftime-trace
   std::string TimeTracePath;
 
+  /// Output Path for module output file.
+  std::string ModuleOutputPath;
+
 public:
   FrontendOptions()
       : DisableFree(false), RelocatablePCH(false), ShowHelp(false),
@@ -582,7 +589,8 @@ class FrontendOptions {
         AllowPCMWithCompilerErrors(false), ModulesShareFileManager(true),
         EmitSymbolGraph(false), EmitExtensionSymbolGraphs(false),
         EmitSymbolGraphSymbolLabelsForTesting(false),
-        EmitPrettySymbolGraphs(false), TimeTraceGranularity(500) {}
+        EmitPrettySymbolGraphs(false), GenReducedBMI(false),
+        TimeTraceGranularity(500) {}
 
   /// getInputKindForExtension - Return the appropriate input kind for a file
   /// extension. For example, "c" would return Language::C.

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 {
@@ -27,6 +28,16 @@ enum class VerificationMode {
 using LibAttrs = llvm::StringMap<ArchitectureSet>;
 using ReexportedInterfaces = llvm::SmallVector<llvm::MachO::InterfaceFile, 8>;
 
+// Pointers to information about a zippered declaration used for
+// querying and reporting violations against different
+// declarations that all map to the same symbol.
+struct ZipperedDeclSource {
+  const FrontendAttrs *FA;
+  clang::SourceManager *SrcMgr;
+  Target T;
+};
+using ZipperedDeclSources = std::vector<ZipperedDeclSource>;
+
 /// Service responsible to tracking state of verification across the
 /// lifetime of InstallAPI.
 /// As declarations are collected during AST traversal, they are
@@ -67,10 +78,10 @@ class DylibVerifier : llvm::MachO::RecordVisitor {
   DylibVerifier() = default;
 
   DylibVerifier(llvm::MachO::Records &&Dylib, ReexportedInterfaces &&Reexports,
-                DiagnosticsEngine *Diag, VerificationMode Mode, bool Demangle,
-                StringRef DSYMPath)
+                DiagnosticsEngine *Diag, VerificationMode Mode, bool Zippered,
+                bool Demangle, StringRef DSYMPath)
       : Dylib(std::move(Dylib)), Reexports(std::move(Reexports)), Mode(Mode),
-        Demangle(Demangle), DSYMPath(DSYMPath),
+        Zippered(Zippered), Demangle(Demangle), DSYMPath(DSYMPath),
         Exports(std::make_unique<SymbolSet>()), Ctx(VerifierContext{Diag}) {}
 
   Result verify(GlobalRecord *R, const FrontendAttrs *FA);
@@ -99,11 +110,7 @@ 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.
@@ -121,6 +128,15 @@ class DylibVerifier : llvm::MachO::RecordVisitor {
   /// symbols should be omitted from the text-api file.
   bool shouldIgnoreReexport(const Record *R, SymbolContext &SymCtx) const;
 
+  // Ignore and omit unavailable symbols in zippered libraries.
+  bool shouldIgnoreZipperedAvailability(const Record *R, SymbolContext &SymCtx);
+
+  // Check if an internal declaration in zippered library has an
+  // external declaration for a different platform. This results
+  // in the symbol being in a "seperate" platform slice.
+  bool shouldIgnoreInternalZipperedSymbol(const Record *R,
+                                          const SymbolContext &SymCtx) const;
+
   /// Compare the visibility declarations to the linkage of symbol found in
   /// dylib.
   Result compareVisibility(const Record *R, SymbolContext &SymCtx,
@@ -176,6 +192,9 @@ class DylibVerifier : llvm::MachO::RecordVisitor {
   // Controls what class of violations to report.
   VerificationMode Mode = VerificationMode::Invalid;
 
+  // Library is zippered.
+  bool Zippered = false;
+
   // Attempt to demangle when reporting violations.
   bool Demangle = false;
 
@@ -185,11 +204,18 @@ class DylibVerifier : llvm::MachO::RecordVisitor {
   // Valid symbols in final text file.
   std::unique_ptr<SymbolSet> Exports = std::make_unique<SymbolSet>();
 
+  // Unavailable or obsoleted declarations for a zippered library.
+  // These are cross referenced against symbols in the dylib.
+  llvm::StringMap<ZipperedDeclSources> DeferredZipperedSymbols;
+
   // Track current state of verification while traversing AST.
   VerifierContext Ctx;
 
   // 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/HeaderSearch.h b/clang/include/clang/Lex/HeaderSearch.h
@@ -547,14 +547,15 @@ class HeaderSearch {
   /// Return whether the specified file is a normal header,
   /// a system header, or a C++ friendly system header.
   SrcMgr::CharacteristicKind getFileDirFlavor(FileEntryRef File) {
-    return (SrcMgr::CharacteristicKind)getFileInfo(File).DirInfo;
+    if (const HeaderFileInfo *HFI = getExistingFileInfo(File))
+      return (SrcMgr::CharacteristicKind)HFI->DirInfo;
+    return (SrcMgr::CharacteristicKind)HeaderFileInfo().DirInfo;
   }
 
   /// Mark the specified file as a "once only" file due to
   /// \#pragma once.
   void MarkFileIncludeOnce(FileEntryRef File) {
-    HeaderFileInfo &FI = getFileInfo(File);
-    FI.isPragmaOnce = true;
+    getFileInfo(File).isPragmaOnce = true;
   }
 
   /// Mark the specified file as a system header, e.g. due to
@@ -834,16 +835,17 @@ class HeaderSearch {
 
   unsigned header_file_size() const { return FileInfo.size(); }
 
-  /// Return the HeaderFileInfo structure for the specified FileEntry,
-  /// in preparation for updating it in some way.
+  /// Return the HeaderFileInfo structure for the specified FileEntry, in
+  /// preparation for updating it in some way.
   HeaderFileInfo &getFileInfo(FileEntryRef FE);
 
-  /// Return the HeaderFileInfo structure for the specified FileEntry,
-  /// if it has ever been filled in.
-  /// \param WantExternal Whether the caller wants purely-external header file
-  ///        info (where \p External is true).
-  const HeaderFileInfo *getExistingFileInfo(FileEntryRef FE,
-                                            bool WantExternal = true) const;
+  /// Return the HeaderFileInfo structure for the specified FileEntry, if it has
+  /// ever been filled in (either locally or externally).
+  const HeaderFileInfo *getExistingFileInfo(FileEntryRef FE) const;
+
+  /// Return the headerFileInfo structure for the specified FileEntry, if it has
+  /// ever been filled in locally.
+  const HeaderFileInfo *getExistingLocalFileInfo(FileEntryRef FE) const;
 
   SearchDirIterator search_dir_begin() { return {*this, 0}; }
   SearchDirIterator search_dir_end() { return {*this, SearchDirs.size()}; }

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
@@ -18,6 +18,7 @@
 #include "clang/Lex/CodeCompletionHandler.h"
 #include "clang/Lex/Preprocessor.h"
 #include "clang/Sema/Sema.h"
+#include "clang/Sema/SemaOpenMP.h"
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/Frontend/OpenMP/OMPContext.h"
 #include "llvm/Support/SaveAndRestore.h"
@@ -329,7 +330,7 @@ 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.
@@ -1601,6 +1602,8 @@ class Parser : public CodeCompletionHandler {
                                      const ParsedTemplateInfo &TemplateInfo,
                                      const VirtSpecifiers &VS,
                                      SourceLocation PureSpecLoc);
+  StringLiteral *ParseCXXDeletedFunctionMessage();
+  void SkipDeletedFunctionBody();
   void ParseCXXNonStaticMemberInitializer(Decl *VarD);
   void ParseLexedAttributes(ParsingClass &Class);
   void ParseLexedAttributeList(LateParsedAttrList &LAs, Decl *D,
@@ -1927,15 +1930,11 @@ 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
@@ -2539,7 +2538,7 @@ class Parser : public CodeCompletionHandler {
   /// Returns true for declaration, false for expression.
   bool isForInitDeclaration() {
     if (getLangOpts().OpenMP)
-      Actions.startOpenMPLoop();
+      Actions.OpenMP().startOpenMPLoop();
     if (getLangOpts().CPlusPlus)
       return Tok.is(tok::kw_using) ||
              isCXXSimpleDeclaration(/*AllowForRangeDecl=*/true);
@@ -3398,7 +3397,7 @@ class Parser : public CodeCompletionHandler {
                           SourceLocation Loc);
 
   /// Parse clauses for '#pragma omp [begin] declare target'.
-  void ParseOMPDeclareTargetClauses(Sema::DeclareTargetContextInfo &DTCI);
+  void ParseOMPDeclareTargetClauses(SemaOpenMP::DeclareTargetContextInfo &DTCI);
 
   /// Parse '#pragma omp end declare target'.
   void ParseOMPEndDeclareTargetDirective(OpenMPDirectiveKind BeginDKind,
@@ -3488,7 +3487,7 @@ class Parser : public CodeCompletionHandler {
   /// Parses indirect clause
   /// \param ParseOnly true to skip the clause's semantic actions and return
   // false;
-  bool ParseOpenMPIndirectClause(Sema::DeclareTargetContextInfo &DTCI,
+  bool ParseOpenMPIndirectClause(SemaOpenMP::DeclareTargetContextInfo &DTCI,
                                  bool ParseOnly);
   /// Parses clause with a single expression and an additional argument
   /// of a kind \a Kind.
@@ -3558,24 +3557,24 @@ class Parser : public CodeCompletionHandler {
 
   /// Parses a reserved locator like 'omp_all_memory'.
   bool ParseOpenMPReservedLocator(OpenMPClauseKind Kind,
-                                  Sema::OpenMPVarListDataTy &Data,
+                                  SemaOpenMP::OpenMPVarListDataTy &Data,
                                   const LangOptions &LangOpts);
   /// Parses clauses with list.
   bool ParseOpenMPVarList(OpenMPDirectiveKind DKind, OpenMPClauseKind Kind,
                           SmallVectorImpl<Expr *> &Vars,
-                          Sema::OpenMPVarListDataTy &Data);
+                          SemaOpenMP::OpenMPVarListDataTy &Data);
   bool ParseUnqualifiedId(CXXScopeSpec &SS, ParsedType ObjectType,
                           bool ObjectHadErrors, bool EnteringContext,
                           bool AllowDestructorName, bool AllowConstructorName,
                           bool AllowDeductionGuide,
                           SourceLocation *TemplateKWLoc, UnqualifiedId &Result);
 
   /// Parses the mapper modifier in map, to, and from clauses.
-  bool parseMapperModifier(Sema::OpenMPVarListDataTy &Data);
+  bool parseMapperModifier(SemaOpenMP::OpenMPVarListDataTy &Data);
   /// Parses map-type-modifiers in map clause.
   /// map([ [map-type-modifier[,] [map-type-modifier[,] ...] map-type : ] list)
   /// where, map-type-modifier ::= always | close | mapper(mapper-identifier)
-  bool parseMapTypeModifiers(Sema::OpenMPVarListDataTy &Data);
+  bool parseMapTypeModifiers(SemaOpenMP::OpenMPVarListDataTy &Data);
 
   //===--------------------------------------------------------------------===//
   // OpenACC Parsing.
@@ -3661,6 +3660,8 @@ class Parser : public CodeCompletionHandler {
   bool ParseOpenACCGangArgList();
   /// Parses a 'gang-arg', used for the 'gang' clause.
   bool ParseOpenACCGangArg();
+  /// Parses a 'condition' expr, ensuring it results in a
+  ExprResult ParseOpenACCConditionExpr();
 
 private:
   //===--------------------------------------------------------------------===//

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.