[NFC] [Serialization] Use semantical type 'DeclID' for 'CreateDeserialized'

Previously we use 'unsigned' as the type of ID in 'CreateDeserialized'.

And the type of `DeclID` in serialization is 'uint32_t', so there is
minor inconsistency.

Also more importantly, if we want to extend the type of DeclID from
uint32_t to uint64_t, we may be in trouble due to we forgot updating the
a lot of 'CreateDeserialized'.

So this patch tries to use semantical type 'DeclID' for
'*Decl::CreateDeserialized' to make sure it is tightly consistent.

15 files changed, 177 insertions, 173 deletions

diff --git a/clang/include/clang/AST/Decl.h b/clang/include/clang/AST/Decl.h
index 0a9c9e1..8b12189 100644
--- a/clang/include/clang/AST/Decl.h
+++ b/clang/include/clang/AST/Decl.h
@@ -157,7 +157,7 @@ public:
                                    SourceLocation CommentLoc,
                                    PragmaMSCommentKind CommentKind,
                                    StringRef Arg);
-  static PragmaCommentDecl *CreateDeserialized(ASTContext &C, unsigned ID,
+  static PragmaCommentDecl *CreateDeserialized(ASTContext &C, DeclID ID,
                                                unsigned ArgSize);
 
   PragmaMSCommentKind getCommentKind() const { return CommentKind; }
@@ -192,7 +192,7 @@ public:
                                           SourceLocation Loc, StringRef Name,
                                           StringRef Value);
   static PragmaDetectMismatchDecl *
-  CreateDeserialized(ASTContext &C, unsigned ID, unsigned NameValueSize);
+  CreateDeserialized(ASTContext &C, DeclID ID, unsigned NameValueSize);
 
   StringRef getName() const { return getTrailingObjects<char>(); }
   StringRef getValue() const { return getTrailingObjects<char>() + ValueStart; }
@@ -518,7 +518,7 @@ public:
   static LabelDecl *Create(ASTContext &C, DeclContext *DC,
                            SourceLocation IdentL, IdentifierInfo *II,
                            SourceLocation GnuLabelL);
-  static LabelDecl *CreateDeserialized(ASTContext &C, unsigned ID);
+  static LabelDecl *CreateDeserialized(ASTContext &C, DeclID ID);
 
   LabelStmt *getStmt() const { return TheStmt; }
   void setStmt(LabelStmt *T) { TheStmt = T; }
@@ -581,7 +581,7 @@ public:
                                IdentifierInfo *Id, NamespaceDecl *PrevDecl,
                                bool Nested);
 
-  static NamespaceDecl *CreateDeserialized(ASTContext &C, unsigned ID);
+  static NamespaceDecl *CreateDeserialized(ASTContext &C, DeclID ID);
 
   using redecl_range = redeclarable_base::redecl_range;
   using redecl_iterator = redeclarable_base::redecl_iterator;
@@ -1146,7 +1146,7 @@ public:
                          const IdentifierInfo *Id, QualType T,
                          TypeSourceInfo *TInfo, StorageClass S);
 
-  static VarDecl *CreateDeserialized(ASTContext &C, unsigned ID);
+  static VarDecl *CreateDeserialized(ASTContext &C, DeclID ID);
 
   SourceRange getSourceRange() const override LLVM_READONLY;
 
@@ -1728,7 +1728,7 @@ public:
   static ImplicitParamDecl *Create(ASTContext &C, QualType T,
                                    ImplicitParamKind ParamKind);
 
-  static ImplicitParamDecl *CreateDeserialized(ASTContext &C, unsigned ID);
+  static ImplicitParamDecl *CreateDeserialized(ASTContext &C, DeclID ID);
 
   ImplicitParamDecl(ASTContext &C, DeclContext *DC, SourceLocation IdLoc,
                     const IdentifierInfo *Id, QualType Type,
@@ -1782,7 +1782,7 @@ public:
                              TypeSourceInfo *TInfo, StorageClass S,
                              Expr *DefArg);
 
-  static ParmVarDecl *CreateDeserialized(ASTContext &C, unsigned ID);
+  static ParmVarDecl *CreateDeserialized(ASTContext &C, DeclID ID);
 
   SourceRange getSourceRange() const override LLVM_READONLY;
 
@@ -2178,7 +2178,7 @@ public:
          bool hasWrittenPrototype, ConstexprSpecKind ConstexprKind,
          Expr *TrailingRequiresClause);
 
-  static FunctionDecl *CreateDeserialized(ASTContext &C, unsigned ID);
+  static FunctionDecl *CreateDeserialized(ASTContext &C, DeclID ID);
 
   DeclarationNameInfo getNameInfo() const {
     return DeclarationNameInfo(getDeclName(), getLocation(), DNLoc);
@@ -3136,7 +3136,7 @@ public:
                            TypeSourceInfo *TInfo, Expr *BW, bool Mutable,
                            InClassInitStyle InitStyle);
 
-  static FieldDecl *CreateDeserialized(ASTContext &C, unsigned ID);
+  static FieldDecl *CreateDeserialized(ASTContext &C, DeclID ID);
 
   /// Returns the index of this field within its record,
   /// as appropriate for passing to ASTRecordLayout::getFieldOffset.
@@ -3311,7 +3311,7 @@ public:
                                   SourceLocation L, IdentifierInfo *Id,
                                   QualType T, Expr *E,
                                   const llvm::APSInt &V);
-  static EnumConstantDecl *CreateDeserialized(ASTContext &C, unsigned ID);
+  static EnumConstantDecl *CreateDeserialized(ASTContext &C, DeclID ID);
 
   const Expr *getInitExpr() const { return (const Expr*) Init; }
   Expr *getInitExpr() { return (Expr*) Init; }
@@ -3357,7 +3357,7 @@ public:
                                    QualType T,
                                    llvm::MutableArrayRef<NamedDecl *> CH);
 
-  static IndirectFieldDecl *CreateDeserialized(ASTContext &C, unsigned ID);
+  static IndirectFieldDecl *CreateDeserialized(ASTContext &C, DeclID ID);
 
   using chain_iterator = ArrayRef<NamedDecl *>::const_iterator;
 
@@ -3542,7 +3542,7 @@ public:
   static TypedefDecl *Create(ASTContext &C, DeclContext *DC,
                              SourceLocation StartLoc, SourceLocation IdLoc,
                              const IdentifierInfo *Id, TypeSourceInfo *TInfo);
-  static TypedefDecl *CreateDeserialized(ASTContext &C, unsigned ID);
+  static TypedefDecl *CreateDeserialized(ASTContext &C, DeclID ID);
 
   SourceRange getSourceRange() const override LLVM_READONLY;
 
@@ -3567,7 +3567,7 @@ public:
   static TypeAliasDecl *Create(ASTContext &C, DeclContext *DC,
                                SourceLocation StartLoc, SourceLocation IdLoc,
                                const IdentifierInfo *Id, TypeSourceInfo *TInfo);
-  static TypeAliasDecl *CreateDeserialized(ASTContext &C, unsigned ID);
+  static TypeAliasDecl *CreateDeserialized(ASTContext &C, DeclID ID);
 
   SourceRange getSourceRange() const override LLVM_READONLY;
 
@@ -3977,7 +3977,7 @@ public:
                           IdentifierInfo *Id, EnumDecl *PrevDecl,
                           bool IsScoped, bool IsScopedUsingClassTag,
                           bool IsFixed);
-  static EnumDecl *CreateDeserialized(ASTContext &C, unsigned ID);
+  static EnumDecl *CreateDeserialized(ASTContext &C, DeclID ID);
 
   /// Overrides to provide correct range when there's an enum-base specifier
   /// with forward declarations.
@@ -4182,7 +4182,7 @@ public:
   static RecordDecl *Create(const ASTContext &C, TagKind TK, DeclContext *DC,
                             SourceLocation StartLoc, SourceLocation IdLoc,
                             IdentifierInfo *Id, RecordDecl* PrevDecl = nullptr);
-  static RecordDecl *CreateDeserialized(const ASTContext &C, unsigned ID);
+  static RecordDecl *CreateDeserialized(const ASTContext &C, DeclID ID);
 
   RecordDecl *getPreviousDecl() {
     return cast_or_null<RecordDecl>(
@@ -4433,7 +4433,7 @@ public:
                                   StringLiteral *Str, SourceLocation AsmLoc,
                                   SourceLocation RParenLoc);
 
-  static FileScopeAsmDecl *CreateDeserialized(ASTContext &C, unsigned ID);
+  static FileScopeAsmDecl *CreateDeserialized(ASTContext &C, DeclID ID);
 
   SourceLocation getAsmLoc() const { return getLocation(); }
   SourceLocation getRParenLoc() const { return RParenLoc; }
@@ -4469,7 +4469,7 @@ class TopLevelStmtDecl : public Decl, public DeclContext {
 
 public:
   static TopLevelStmtDecl *Create(ASTContext &C, Stmt *Statement);
-  static TopLevelStmtDecl *CreateDeserialized(ASTContext &C, unsigned ID);
+  static TopLevelStmtDecl *CreateDeserialized(ASTContext &C, DeclID ID);
 
   SourceRange getSourceRange() const override LLVM_READONLY;
   Stmt *getStmt() { return Statement; }
@@ -4563,7 +4563,7 @@ protected:
 
 public:
   static BlockDecl *Create(ASTContext &C, DeclContext *DC, SourceLocation L);
-  static BlockDecl *CreateDeserialized(ASTContext &C, unsigned ID);
+  static BlockDecl *CreateDeserialized(ASTContext &C, DeclID ID);
 
   SourceLocation getCaretLocation() const { return getLocation(); }
 
@@ -4717,7 +4717,7 @@ public:
 
   static CapturedDecl *Create(ASTContext &C, DeclContext *DC,
                               unsigned NumParams);
-  static CapturedDecl *CreateDeserialized(ASTContext &C, unsigned ID,
+  static CapturedDecl *CreateDeserialized(ASTContext &C, DeclID ID,
                                           unsigned NumParams);
 
   Stmt *getBody() const override;
@@ -4851,7 +4851,7 @@ public:
                                     SourceLocation EndLoc);
 
   /// Create a new, deserialized module import declaration.
-  static ImportDecl *CreateDeserialized(ASTContext &C, unsigned ID,
+  static ImportDecl *CreateDeserialized(ASTContext &C, DeclID ID,
                                         unsigned NumLocations);
 
   /// Retrieve the module that was imported by the import declaration.
@@ -4892,7 +4892,7 @@ private:
 public:
   static ExportDecl *Create(ASTContext &C, DeclContext *DC,
                             SourceLocation ExportLoc);
-  static ExportDecl *CreateDeserialized(ASTContext &C, unsigned ID);
+  static ExportDecl *CreateDeserialized(ASTContext &C, DeclID ID);
 
   SourceLocation getExportLoc() const { return getLocation(); }
   SourceLocation getRBraceLoc() const { return RBraceLoc; }
@@ -4931,7 +4931,7 @@ class EmptyDecl : public Decl {
 public:
   static EmptyDecl *Create(ASTContext &C, DeclContext *DC,
                            SourceLocation L);
-  static EmptyDecl *CreateDeserialized(ASTContext &C, unsigned ID);
+  static EmptyDecl *CreateDeserialized(ASTContext &C, DeclID ID);
 
   static bool classof(const Decl *D) { return classofKind(D->getKind()); }
   static bool classofKind(Kind K) { return K == Empty; }
@@ -4957,7 +4957,7 @@ public:
                                 bool CBuffer, SourceLocation KwLoc,
                                 IdentifierInfo *ID, SourceLocation IDLoc,
                                 SourceLocation LBrace);
-  static HLSLBufferDecl *CreateDeserialized(ASTContext &C, unsigned ID);
+  static HLSLBufferDecl *CreateDeserialized(ASTContext &C, DeclID ID);
 
   SourceRange getSourceRange() const override LLVM_READONLY {
     return SourceRange(getLocStart(), RBraceLoc);
diff --git a/clang/include/clang/AST/DeclBase.h b/clang/include/clang/AST/DeclBase.h
index 1079993..161e14f 100644
--- a/clang/include/clang/AST/DeclBase.h
+++ b/clang/include/clang/AST/DeclBase.h
@@ -349,6 +349,8 @@ protected:
   LLVM_PREFERRED_TYPE(Linkage)
   mutable unsigned CacheValidAndLinkage : 3;
 
+  using DeclID = uint32_t;
+
   /// Allocate memory for a deserialized declaration.
   ///
   /// This routine must be used to allocate memory for any declaration that is
@@ -358,7 +360,7 @@ protected:
   /// \param Ctx The context in which we will allocate memory.
   /// \param ID The global ID of the deserialized declaration.
   /// \param Extra The amount of extra space to allocate after the object.
-  void *operator new(std::size_t Size, const ASTContext &Ctx, unsigned ID,
+  void *operator new(std::size_t Size, const ASTContext &Ctx, DeclID ID,
                      std::size_t Extra = 0);
 
   /// Allocate memory for a non-deserialized declaration.
diff --git a/clang/include/clang/AST/DeclCXX.h b/clang/include/clang/AST/DeclCXX.h
index 7aed4d5..a7644d2 100644
--- a/clang/include/clang/AST/DeclCXX.h
+++ b/clang/include/clang/AST/DeclCXX.h
@@ -120,7 +120,7 @@ public:
     return new (C, DC) AccessSpecDecl(AS, DC, ASLoc, ColonLoc);
   }
 
-  static AccessSpecDecl *CreateDeserialized(ASTContext &C, unsigned ID);
+  static AccessSpecDecl *CreateDeserialized(ASTContext &C, DeclID ID);
 
   // Implement isa/cast/dyncast/etc.
   static bool classof(const Decl *D) { return classofKind(D->getKind()); }
@@ -579,7 +579,7 @@ public:
                                      TypeSourceInfo *Info, SourceLocation Loc,
                                      unsigned DependencyKind, bool IsGeneric,
                                      LambdaCaptureDefault CaptureDefault);
-  static CXXRecordDecl *CreateDeserialized(const ASTContext &C, unsigned ID);
+  static CXXRecordDecl *CreateDeserialized(const ASTContext &C, DeclID ID);
 
   bool isDynamicClass() const {
     return data().Polymorphic || data().NumVBases != 0;
@@ -1980,7 +1980,7 @@ public:
          CXXConstructorDecl *Ctor = nullptr,
          DeductionCandidate Kind = DeductionCandidate::Normal);
 
-  static CXXDeductionGuideDecl *CreateDeserialized(ASTContext &C, unsigned ID);
+  static CXXDeductionGuideDecl *CreateDeserialized(ASTContext &C, DeclID ID);
 
   ExplicitSpecifier getExplicitSpecifier() { return ExplicitSpec; }
   const ExplicitSpecifier getExplicitSpecifier() const { return ExplicitSpec; }
@@ -2035,7 +2035,7 @@ public:
   static RequiresExprBodyDecl *Create(ASTContext &C, DeclContext *DC,
                                       SourceLocation StartLoc);
 
-  static RequiresExprBodyDecl *CreateDeserialized(ASTContext &C, unsigned ID);
+  static RequiresExprBodyDecl *CreateDeserialized(ASTContext &C, DeclID ID);
 
   // Implement isa/cast/dyncast/etc.
   static bool classof(const Decl *D) { return classofKind(D->getKind()); }
@@ -2078,7 +2078,7 @@ public:
          ConstexprSpecKind ConstexprKind, SourceLocation EndLocation,
          Expr *TrailingRequiresClause = nullptr);
 
-  static CXXMethodDecl *CreateDeserialized(ASTContext &C, unsigned ID);
+  static CXXMethodDecl *CreateDeserialized(ASTContext &C, DeclID ID);
 
   bool isStatic() const;
   bool isInstance() const { return !isStatic(); }
@@ -2579,7 +2579,7 @@ public:
   friend class ASTDeclWriter;
   friend TrailingObjects;
 
-  static CXXConstructorDecl *CreateDeserialized(ASTContext &C, unsigned ID,
+  static CXXConstructorDecl *CreateDeserialized(ASTContext &C, DeclID ID,
                                                 uint64_t AllocKind);
   static CXXConstructorDecl *
   Create(ASTContext &C, CXXRecordDecl *RD, SourceLocation StartLoc,
@@ -2822,7 +2822,7 @@ public:
          bool UsesFPIntrin, bool isInline, bool isImplicitlyDeclared,
          ConstexprSpecKind ConstexprKind,
          Expr *TrailingRequiresClause = nullptr);
-  static CXXDestructorDecl *CreateDeserialized(ASTContext & C, unsigned ID);
+  static CXXDestructorDecl *CreateDeserialized(ASTContext & C, DeclID ID);
 
   void setOperatorDelete(FunctionDecl *OD, Expr *ThisArg);
 
@@ -2881,7 +2881,7 @@ public:
          bool UsesFPIntrin, bool isInline, ExplicitSpecifier ES,
          ConstexprSpecKind ConstexprKind, SourceLocation EndLocation,
          Expr *TrailingRequiresClause = nullptr);
-  static CXXConversionDecl *CreateDeserialized(ASTContext &C, unsigned ID);
+  static CXXConversionDecl *CreateDeserialized(ASTContext &C, DeclID ID);
 
   ExplicitSpecifier getExplicitSpecifier() {
     return getCanonicalDecl()->ExplicitSpec;
@@ -2948,7 +2948,7 @@ public:
                                  SourceLocation ExternLoc,
                                  SourceLocation LangLoc,
                                  LinkageSpecLanguageIDs Lang, bool HasBraces);
-  static LinkageSpecDecl *CreateDeserialized(ASTContext &C, unsigned ID);
+  static LinkageSpecDecl *CreateDeserialized(ASTContext &C, DeclID ID);
 
   /// Return the language specified by this linkage specification.
   LinkageSpecLanguageIDs getLanguage() const {
@@ -3096,7 +3096,7 @@ public:
                                     SourceLocation IdentLoc,
                                     NamedDecl *Nominated,
                                     DeclContext *CommonAncestor);
-  static UsingDirectiveDecl *CreateDeserialized(ASTContext &C, unsigned ID);
+  static UsingDirectiveDecl *CreateDeserialized(ASTContext &C, DeclID ID);
 
   SourceRange getSourceRange() const override LLVM_READONLY {
     return SourceRange(UsingLoc, getLocation());
@@ -3157,7 +3157,7 @@ public:
                                     SourceLocation IdentLoc,
                                     NamedDecl *Namespace);
 
-  static NamespaceAliasDecl *CreateDeserialized(ASTContext &C, unsigned ID);
+  static NamespaceAliasDecl *CreateDeserialized(ASTContext &C, DeclID ID);
 
   using redecl_range = redeclarable_base::redecl_range;
   using redecl_iterator = redeclarable_base::redecl_iterator;
@@ -3254,7 +3254,7 @@ public:
         LifetimeExtendedTemporaryDecl(Temp, EDec, Mangling);
   }
   static LifetimeExtendedTemporaryDecl *CreateDeserialized(ASTContext &C,
-                                                           unsigned ID) {
+                                                           DeclID ID) {
     return new (C, ID) LifetimeExtendedTemporaryDecl(EmptyShell{});
   }
 
@@ -3357,7 +3357,7 @@ public:
         UsingShadowDecl(UsingShadow, C, DC, Loc, Name, Introducer, Target);
   }
 
-  static UsingShadowDecl *CreateDeserialized(ASTContext &C, unsigned ID);
+  static UsingShadowDecl *CreateDeserialized(ASTContext &C, DeclID ID);
 
   using redecl_range = redeclarable_base::redecl_range;
   using redecl_iterator = redeclarable_base::redecl_iterator;
@@ -3566,7 +3566,7 @@ public:
                            const DeclarationNameInfo &NameInfo,
                            bool HasTypenameKeyword);
 
-  static UsingDecl *CreateDeserialized(ASTContext &C, unsigned ID);
+  static UsingDecl *CreateDeserialized(ASTContext &C, DeclID ID);
 
   SourceRange getSourceRange() const override LLVM_READONLY;
 
@@ -3645,7 +3645,7 @@ public:
                                             UsingDecl *Using, NamedDecl *Target,
                                             bool IsVirtual);
   static ConstructorUsingShadowDecl *CreateDeserialized(ASTContext &C,
-                                                        unsigned ID);
+                                                        DeclID ID);
 
   /// Override the UsingShadowDecl's getIntroducer, returning the UsingDecl that
   /// introduced this.
@@ -3757,7 +3757,7 @@ public:
                                SourceLocation UsingL, SourceLocation EnumL,
                                SourceLocation NameL, TypeSourceInfo *EnumType);
 
-  static UsingEnumDecl *CreateDeserialized(ASTContext &C, unsigned ID);
+  static UsingEnumDecl *CreateDeserialized(ASTContext &C, DeclID ID);
 
   SourceRange getSourceRange() const override LLVM_READONLY;
 
@@ -3830,7 +3830,7 @@ public:
                                NamedDecl *InstantiatedFrom,
                                ArrayRef<NamedDecl *> UsingDecls);
 
-  static UsingPackDecl *CreateDeserialized(ASTContext &C, unsigned ID,
+  static UsingPackDecl *CreateDeserialized(ASTContext &C, DeclID ID,
                                            unsigned NumExpansions);
 
   SourceRange getSourceRange() const override LLVM_READONLY {
@@ -3924,7 +3924,7 @@ public:
            const DeclarationNameInfo &NameInfo, SourceLocation EllipsisLoc);
 
   static UnresolvedUsingValueDecl *
-  CreateDeserialized(ASTContext &C, unsigned ID);
+  CreateDeserialized(ASTContext &C, DeclID ID);
 
   SourceRange getSourceRange() const override LLVM_READONLY;
 
@@ -4015,7 +4015,7 @@ public:
            SourceLocation EllipsisLoc);
 
   static UnresolvedUsingTypenameDecl *
-  CreateDeserialized(ASTContext &C, unsigned ID);
+  CreateDeserialized(ASTContext &C, DeclID ID);
 
   /// Retrieves the canonical declaration of this declaration.
   UnresolvedUsingTypenameDecl *getCanonicalDecl() override {
@@ -4045,7 +4045,7 @@ public:
                                              SourceLocation Loc,
                                              DeclarationName Name);
   static UnresolvedUsingIfExistsDecl *CreateDeserialized(ASTContext &Ctx,
-                                                         unsigned ID);
+                                                         DeclID ID);
 
   static bool classof(const Decl *D) { return classofKind(D->getKind()); }
   static bool classofKind(Kind K) { return K == Decl::UnresolvedUsingIfExists; }
@@ -4073,7 +4073,7 @@ public:
                                   SourceLocation StaticAssertLoc,
                                   Expr *AssertExpr, Expr *Message,
                                   SourceLocation RParenLoc, bool Failed);
-  static StaticAssertDecl *CreateDeserialized(ASTContext &C, unsigned ID);
+  static StaticAssertDecl *CreateDeserialized(ASTContext &C, DeclID ID);
 
   Expr *getAssertExpr() { return AssertExprAndFailed.getPointer(); }
   const Expr *getAssertExpr() const { return AssertExprAndFailed.getPointer(); }
@@ -4120,7 +4120,7 @@ public:
 
   static BindingDecl *Create(ASTContext &C, DeclContext *DC,
                              SourceLocation IdLoc, IdentifierInfo *Id);
-  static BindingDecl *CreateDeserialized(ASTContext &C, unsigned ID);
+  static BindingDecl *CreateDeserialized(ASTContext &C, DeclID ID);
 
   /// Get the expression to which this declaration is bound. This may be null
   /// in two different cases: while parsing the initializer for the
@@ -4189,7 +4189,7 @@ public:
                                    QualType T, TypeSourceInfo *TInfo,
                                    StorageClass S,
                                    ArrayRef<BindingDecl *> Bindings);
-  static DecompositionDecl *CreateDeserialized(ASTContext &C, unsigned ID,
+  static DecompositionDecl *CreateDeserialized(ASTContext &C, DeclID ID,
                                                unsigned NumBindings);
 
   ArrayRef<BindingDecl *> bindings() const {
@@ -4246,7 +4246,7 @@ public:
                                 SourceLocation L, DeclarationName N, QualType T,
                                 TypeSourceInfo *TInfo, SourceLocation StartL,
                                 IdentifierInfo *Getter, IdentifierInfo *Setter);
-  static MSPropertyDecl *CreateDeserialized(ASTContext &C, unsigned ID);
+  static MSPropertyDecl *CreateDeserialized(ASTContext &C, DeclID ID);
 
   static bool classof(const Decl *D) { return D->getKind() == MSProperty; }
 
@@ -4300,7 +4300,7 @@ private:
   MSGuidDecl(DeclContext *DC, QualType T, Parts P);
 
   static MSGuidDecl *Create(const ASTContext &C, QualType T, Parts P);
-  static MSGuidDecl *CreateDeserialized(ASTContext &C, unsigned ID);
+  static MSGuidDecl *CreateDeserialized(ASTContext &C, DeclID ID);
 
   // Only ASTContext::getMSGuidDecl and deserialization create these.
   friend class ASTContext;
@@ -4353,7 +4353,7 @@ class UnnamedGlobalConstantDecl : public ValueDecl,
   static UnnamedGlobalConstantDecl *Create(const ASTContext &C, QualType T,
                                            const APValue &APVal);
   static UnnamedGlobalConstantDecl *CreateDeserialized(ASTContext &C,
-                                                       unsigned ID);
+                                                       DeclID ID);
 
   // Only ASTContext::getUnnamedGlobalConstantDecl and deserialization create
   // these.
diff --git a/clang/include/clang/AST/DeclFriend.h b/clang/include/clang/AST/DeclFriend.h
index 3e6ca5b..b56627a 100644
--- a/clang/include/clang/AST/DeclFriend.h
+++ b/clang/include/clang/AST/DeclFriend.h
@@ -112,7 +112,7 @@ public:
   Create(ASTContext &C, DeclContext *DC, SourceLocation L, FriendUnion Friend_,
          SourceLocation FriendL,
          ArrayRef<TemplateParameterList *> FriendTypeTPLists = std::nullopt);
-  static FriendDecl *CreateDeserialized(ASTContext &C, unsigned ID,
+  static FriendDecl *CreateDeserialized(ASTContext &C, DeclID ID,
                                         unsigned FriendTypeNumTPLists);
 
   /// If this friend declaration names an (untemplated but possibly
diff --git a/clang/include/clang/AST/DeclObjC.h b/clang/include/clang/AST/DeclObjC.h
index b8d17dd..7780afa 100644
--- a/clang/include/clang/AST/DeclObjC.h
+++ b/clang/include/clang/AST/DeclObjC.h
@@ -236,7 +236,7 @@ public:
          ObjCImplementationControl impControl = ObjCImplementationControl::None,
          bool HasRelatedResultType = false);
 
-  static ObjCMethodDecl *CreateDeserialized(ASTContext &C, unsigned ID);
+  static ObjCMethodDecl *CreateDeserialized(ASTContext &C, DeclID ID);
 
   ObjCMethodDecl *getCanonicalDecl() override;
   const ObjCMethodDecl *getCanonicalDecl() const {
@@ -614,7 +614,7 @@ public:
                                    IdentifierInfo *name,
                                    SourceLocation colonLoc,
                                    TypeSourceInfo *boundInfo);
-  static ObjCTypeParamDecl *CreateDeserialized(ASTContext &ctx, unsigned ID);
+  static ObjCTypeParamDecl *CreateDeserialized(ASTContext &ctx, DeclID ID);
 
   SourceRange getSourceRange() const override LLVM_READONLY;
 
@@ -789,7 +789,7 @@ public:
                                   TypeSourceInfo *TSI,
                                   PropertyControl propControl = None);
 
-  static ObjCPropertyDecl *CreateDeserialized(ASTContext &C, unsigned ID);
+  static ObjCPropertyDecl *CreateDeserialized(ASTContext &C, DeclID ID);
 
   SourceLocation getAtLoc() const { return AtLoc; }
   void setAtLoc(SourceLocation L) { AtLoc = L; }
@@ -1279,7 +1279,7 @@ public:
          ObjCInterfaceDecl *PrevDecl,
          SourceLocation ClassLoc = SourceLocation(), bool isInternal = false);
 
-  static ObjCInterfaceDecl *CreateDeserialized(const ASTContext &C, unsigned ID);
+  static ObjCInterfaceDecl *CreateDeserialized(const ASTContext &C, DeclID ID);
 
   /// Retrieve the type parameters of this class.
   ///
@@ -1969,7 +1969,7 @@ public:
                               TypeSourceInfo *TInfo, AccessControl ac,
                               Expr *BW = nullptr, bool synthesized = false);
 
-  static ObjCIvarDecl *CreateDeserialized(ASTContext &C, unsigned ID);
+  static ObjCIvarDecl *CreateDeserialized(ASTContext &C, DeclID ID);
 
   /// Return the class interface that this ivar is logically contained
   /// in; this is either the interface where the ivar was declared, or the
@@ -2039,7 +2039,7 @@ public:
                                      SourceLocation IdLoc, IdentifierInfo *Id,
                                      QualType T, Expr *BW);
 
-  static ObjCAtDefsFieldDecl *CreateDeserialized(ASTContext &C, unsigned ID);
+  static ObjCAtDefsFieldDecl *CreateDeserialized(ASTContext &C, DeclID ID);
 
   // Implement isa/cast/dyncast/etc.
   static bool classof(const Decl *D) { return classofKind(D->getKind()); }
@@ -2142,7 +2142,7 @@ public:
                                   SourceLocation atStartLoc,
                                   ObjCProtocolDecl *PrevDecl);
 
-  static ObjCProtocolDecl *CreateDeserialized(ASTContext &C, unsigned ID);
+  static ObjCProtocolDecl *CreateDeserialized(ASTContext &C, DeclID ID);
 
   const ObjCProtocolList &getReferencedProtocols() const {
     assert(hasDefinition() && "No definition available!");
@@ -2361,7 +2361,7 @@ public:
          ObjCTypeParamList *typeParamList,
          SourceLocation IvarLBraceLoc = SourceLocation(),
          SourceLocation IvarRBraceLoc = SourceLocation());
-  static ObjCCategoryDecl *CreateDeserialized(ASTContext &C, unsigned ID);
+  static ObjCCategoryDecl *CreateDeserialized(ASTContext &C, DeclID ID);
 
   ObjCInterfaceDecl *getClassInterface() { return ClassInterface; }
   const ObjCInterfaceDecl *getClassInterface() const { return ClassInterface; }
@@ -2558,7 +2558,7 @@ public:
   Create(ASTContext &C, DeclContext *DC, const IdentifierInfo *Id,
          ObjCInterfaceDecl *classInterface, SourceLocation nameLoc,
          SourceLocation atStartLoc, SourceLocation CategoryNameLoc);
-  static ObjCCategoryImplDecl *CreateDeserialized(ASTContext &C, unsigned ID);
+  static ObjCCategoryImplDecl *CreateDeserialized(ASTContext &C, DeclID ID);
 
   ObjCCategoryDecl *getCategoryDecl() const;
 
@@ -2640,7 +2640,7 @@ public:
                                         SourceLocation IvarLBraceLoc=SourceLocation(),
                                         SourceLocation IvarRBraceLoc=SourceLocation());
 
-  static ObjCImplementationDecl *CreateDeserialized(ASTContext &C, unsigned ID);
+  static ObjCImplementationDecl *CreateDeserialized(ASTContext &C, DeclID ID);
 
   /// init_iterator - Iterates through the ivar initializer list.
   using init_iterator = CXXCtorInitializer **;
@@ -2780,7 +2780,7 @@ public:
                                          ObjCInterfaceDecl* aliasedClass);
 
   static ObjCCompatibleAliasDecl *CreateDeserialized(ASTContext &C,
-                                                     unsigned ID);
+                                                     DeclID ID);
 
   const ObjCInterfaceDecl *getClassInterface() const { return AliasedClass; }
   ObjCInterfaceDecl *getClassInterface() { return AliasedClass; }
@@ -2851,7 +2851,7 @@ public:
                                       ObjCIvarDecl *ivarDecl,
                                       SourceLocation ivarLoc);
 
-  static ObjCPropertyImplDecl *CreateDeserialized(ASTContext &C, unsigned ID);
+  static ObjCPropertyImplDecl *CreateDeserialized(ASTContext &C, DeclID ID);
 
   SourceRange getSourceRange() const override LLVM_READONLY;
 
diff --git a/clang/include/clang/AST/DeclOpenMP.h b/clang/include/clang/AST/DeclOpenMP.h
index 8fdfddb..c7ede7f 100644
--- a/clang/include/clang/AST/DeclOpenMP.h
+++ b/clang/include/clang/AST/DeclOpenMP.h
@@ -133,7 +133,7 @@ public:
                                       SourceLocation L,
                                       ArrayRef<Expr *> VL);
   static OMPThreadPrivateDecl *CreateDeserialized(ASTContext &C,
-                                                  unsigned ID, unsigned N);
+                                                  DeclID ID, unsigned N);
 
   typedef MutableArrayRef<Expr *>::iterator varlist_iterator;
   typedef ArrayRef<const Expr *>::iterator varlist_const_iterator;
@@ -214,7 +214,7 @@ public:
          QualType T, OMPDeclareReductionDecl *PrevDeclInScope);
   /// Create deserialized declare reduction node.
   static OMPDeclareReductionDecl *CreateDeserialized(ASTContext &C,
-                                                     unsigned ID);
+                                                     DeclID ID);
 
   /// Get combiner expression of the declare reduction construct.
   Expr *getCombiner() { return Combiner; }
@@ -318,7 +318,7 @@ public:
                                       ArrayRef<OMPClause *> Clauses,
                                       OMPDeclareMapperDecl *PrevDeclInScope);
   /// Creates deserialized declare mapper node.
-  static OMPDeclareMapperDecl *CreateDeserialized(ASTContext &C, unsigned ID,
+  static OMPDeclareMapperDecl *CreateDeserialized(ASTContext &C, DeclID ID,
                                                   unsigned N);
 
   using clauselist_iterator = MutableArrayRef<OMPClause *>::iterator;
@@ -397,7 +397,7 @@ public:
                                      IdentifierInfo *Id, QualType T,
                                      SourceLocation StartLoc);
 
-  static OMPCapturedExprDecl *CreateDeserialized(ASTContext &C, unsigned ID);
+  static OMPCapturedExprDecl *CreateDeserialized(ASTContext &C, DeclID ID);
 
   SourceRange getSourceRange() const override LLVM_READONLY;
 
@@ -427,7 +427,7 @@ public:
   static OMPRequiresDecl *Create(ASTContext &C, DeclContext *DC,
                                  SourceLocation L, ArrayRef<OMPClause *> CL);
   /// Create deserialized requires node.
-  static OMPRequiresDecl *CreateDeserialized(ASTContext &C, unsigned ID,
+  static OMPRequiresDecl *CreateDeserialized(ASTContext &C, DeclID ID,
                                              unsigned N);
 
   using clauselist_iterator = MutableArrayRef<OMPClause *>::iterator;
@@ -495,7 +495,7 @@ public:
   static OMPAllocateDecl *Create(ASTContext &C, DeclContext *DC,
                                  SourceLocation L, ArrayRef<Expr *> VL,
                                  ArrayRef<OMPClause *> CL);
-  static OMPAllocateDecl *CreateDeserialized(ASTContext &C, unsigned ID,
+  static OMPAllocateDecl *CreateDeserialized(ASTContext &C, DeclID ID,
                                              unsigned NVars, unsigned NClauses);
 
   typedef MutableArrayRef<Expr *>::iterator varlist_iterator;
diff --git a/clang/include/clang/AST/DeclTemplate.h b/clang/include/clang/AST/DeclTemplate.h
index f24e71f..e2afff8 100644
--- a/clang/include/clang/AST/DeclTemplate.h
+++ b/clang/include/clang/AST/DeclTemplate.h
@@ -1087,7 +1087,7 @@ public:
                                       NamedDecl *Decl);
 
   /// Create an empty function template node.
-  static FunctionTemplateDecl *CreateDeserialized(ASTContext &C, unsigned ID);
+  static FunctionTemplateDecl *CreateDeserialized(ASTContext &C, DeclID ID);
 
   // Implement isa/cast/dyncast support
   static bool classof(const Decl *D) { return classofKind(D->getKind()); }
@@ -1204,9 +1204,9 @@ public:
          bool Typename, bool ParameterPack, bool HasTypeConstraint = false,
          std::optional<unsigned> NumExpanded = std::nullopt);
   static TemplateTypeParmDecl *CreateDeserialized(const ASTContext &C,
-                                                  unsigned ID);
+                                                  DeclID ID);
   static TemplateTypeParmDecl *CreateDeserialized(const ASTContext &C,
-                                                  unsigned ID,
+                                                  DeclID ID,
                                                   bool HasTypeConstraint);
 
   /// Whether this template type parameter was declared with
@@ -1414,10 +1414,10 @@ public:
          ArrayRef<TypeSourceInfo *> ExpandedTInfos);
 
   static NonTypeTemplateParmDecl *CreateDeserialized(ASTContext &C,
-                                                     unsigned ID,
+                                                     DeclID ID,
                                                      bool HasTypeConstraint);
   static NonTypeTemplateParmDecl *CreateDeserialized(ASTContext &C,
-                                                     unsigned ID,
+                                                     DeclID ID,
                                                      unsigned NumExpandedTypes,
                                                      bool HasTypeConstraint);
 
@@ -1632,9 +1632,9 @@ public:
          ArrayRef<TemplateParameterList *> Expansions);
 
   static TemplateTemplateParmDecl *CreateDeserialized(ASTContext &C,
-                                                      unsigned ID);
+                                                      DeclID ID);
   static TemplateTemplateParmDecl *CreateDeserialized(ASTContext &C,
-                                                      unsigned ID,
+                                                      DeclID ID,
                                                       unsigned NumExpansions);
 
   using TemplateParmPosition::getDepth;
@@ -1858,7 +1858,7 @@ public:
          ArrayRef<TemplateArgument> Args,
          ClassTemplateSpecializationDecl *PrevDecl);
   static ClassTemplateSpecializationDecl *
-  CreateDeserialized(ASTContext &C, unsigned ID);
+  CreateDeserialized(ASTContext &C, DeclID ID);
 
   void getNameForDiagnostic(raw_ostream &OS, const PrintingPolicy &Policy,
                             bool Qualified) const override;
@@ -2110,7 +2110,7 @@ public:
          ClassTemplatePartialSpecializationDecl *PrevDecl);
 
   static ClassTemplatePartialSpecializationDecl *
-  CreateDeserialized(ASTContext &C, unsigned ID);
+  CreateDeserialized(ASTContext &C, DeclID ID);
 
   ClassTemplatePartialSpecializationDecl *getMostRecentDecl() {
     return cast<ClassTemplatePartialSpecializationDecl>(
@@ -2306,7 +2306,7 @@ public:
                                    NamedDecl *Decl);
 
   /// Create an empty class template node.
-  static ClassTemplateDecl *CreateDeserialized(ASTContext &C, unsigned ID);
+  static ClassTemplateDecl *CreateDeserialized(ASTContext &C, DeclID ID);
 
   /// Return the specialization with the provided arguments if it exists,
   /// otherwise return the insertion point.
@@ -2472,7 +2472,7 @@ public:
          MutableArrayRef<TemplateParameterList *> Params, FriendUnion Friend,
          SourceLocation FriendLoc);
 
-  static FriendTemplateDecl *CreateDeserialized(ASTContext &C, unsigned ID);
+  static FriendTemplateDecl *CreateDeserialized(ASTContext &C, DeclID ID);
 
   /// If this friend declaration names a templated type (or
   /// a dependent member type of a templated type), return that
@@ -2573,7 +2573,7 @@ public:
                                        NamedDecl *Decl);
 
   /// Create an empty alias template node.
-  static TypeAliasTemplateDecl *CreateDeserialized(ASTContext &C, unsigned ID);
+  static TypeAliasTemplateDecl *CreateDeserialized(ASTContext &C, DeclID ID);
 
   // Implement isa/cast/dyncast support
   static bool classof(const Decl *D) { return classofKind(D->getKind()); }
@@ -2670,7 +2670,7 @@ public:
          TypeSourceInfo *TInfo, StorageClass S,
          ArrayRef<TemplateArgument> Args);
   static VarTemplateSpecializationDecl *CreateDeserialized(ASTContext &C,
-                                                           unsigned ID);
+                                                           DeclID ID);
 
   void getNameForDiagnostic(raw_ostream &OS, const PrintingPolicy &Policy,
                             bool Qualified) const override;
@@ -2901,7 +2901,7 @@ public:
          const TemplateArgumentListInfo &ArgInfos);
 
   static VarTemplatePartialSpecializationDecl *CreateDeserialized(ASTContext &C,
-                                                                  unsigned ID);
+                                                                  DeclID ID);
 
   VarTemplatePartialSpecializationDecl *getMostRecentDecl() {
     return cast<VarTemplatePartialSpecializationDecl>(
@@ -3078,7 +3078,7 @@ public:
                                  VarDecl *Decl);
 
   /// Create an empty variable template node.
-  static VarTemplateDecl *CreateDeserialized(ASTContext &C, unsigned ID);
+  static VarTemplateDecl *CreateDeserialized(ASTContext &C, DeclID ID);
 
   /// Return the specialization with the provided arguments if it exists,
   /// otherwise return the insertion point.
@@ -3183,7 +3183,7 @@ public:
                              SourceLocation L, DeclarationName Name,
                              TemplateParameterList *Params,
                              Expr *ConstraintExpr);
-  static ConceptDecl *CreateDeserialized(ASTContext &C, unsigned ID);
+  static ConceptDecl *CreateDeserialized(ASTContext &C, DeclID ID);
 
   Expr *getConstraintExpr() const {
     return ConstraintExpr;
@@ -3232,7 +3232,7 @@ public:
   Create(const ASTContext &C, DeclContext *DC, SourceLocation SL,
          ArrayRef<TemplateArgument> ConvertedArgs);
   static ImplicitConceptSpecializationDecl *
-  CreateDeserialized(const ASTContext &C, unsigned ID,
+  CreateDeserialized(const ASTContext &C, DeclID ID,
                      unsigned NumTemplateArgs);
 
   ArrayRef<TemplateArgument> getTemplateArguments() const {
@@ -3275,7 +3275,7 @@ private:
   static TemplateParamObjectDecl *Create(const ASTContext &C, QualType T,
                                          const APValue &V);
   static TemplateParamObjectDecl *CreateDeserialized(ASTContext &C,
-                                                     unsigned ID);
+                                                     DeclID ID);
 
   /// Only ASTContext::getTemplateParamObjectDecl and deserialization
   /// create these.
diff --git a/clang/include/clang/Serialization/ASTReader.h b/clang/include/clang/Serialization/ASTReader.h
index 43ee06c5..1cd8b6a 100644
--- a/clang/include/clang/Serialization/ASTReader.h
+++ b/clang/include/clang/Serialization/ASTReader.h
@@ -501,6 +501,8 @@ private:
   /// = I + 1 has already been loaded.
   llvm::PagedVector<Decl *> DeclsLoaded;
 
+  static_assert(std::is_same_v<serialization::DeclID, Decl::DeclID>);
+
   using GlobalDeclMapType =
       ContinuousRangeMap<serialization::DeclID, ModuleFile *, 4>;
 
diff --git a/clang/lib/AST/Decl.cpp b/clang/lib/AST/Decl.cpp
index 1b99c43..474e0cc 100644
--- a/clang/lib/AST/Decl.cpp
+++ b/clang/lib/AST/Decl.cpp
@@ -2151,7 +2151,7 @@ VarDecl *VarDecl::Create(ASTContext &C, DeclContext *DC, SourceLocation StartL,
   return new (C, DC) VarDecl(Var, C, DC, StartL, IdL, Id, T, TInfo, S);
 }
 
-VarDecl *VarDecl::CreateDeserialized(ASTContext &C, unsigned ID) {
+VarDecl *VarDecl::CreateDeserialized(ASTContext &C, Decl::DeclID ID) {
   return new (C, ID)
       VarDecl(Var, C, nullptr, SourceLocation(), SourceLocation(), nullptr,
               QualType(), nullptr, SC_None);
@@ -2929,7 +2929,7 @@ QualType ParmVarDecl::getOriginalType() const {
   return T;
 }
 
-ParmVarDecl *ParmVarDecl::CreateDeserialized(ASTContext &C, unsigned ID) {
+ParmVarDecl *ParmVarDecl::CreateDeserialized(ASTContext &C, Decl::DeclID ID) {
   return new (C, ID)
       ParmVarDecl(ParmVar, C, nullptr, SourceLocation(), SourceLocation(),
                   nullptr, QualType(), nullptr, SC_None, nullptr);
@@ -4553,7 +4553,7 @@ FieldDecl *FieldDecl::Create(const ASTContext &C, DeclContext *DC,
                                BW, Mutable, InitStyle);
 }
 
-FieldDecl *FieldDecl::CreateDeserialized(ASTContext &C, unsigned ID) {
+FieldDecl *FieldDecl::CreateDeserialized(ASTContext &C, Decl::DeclID ID) {
   return new (C, ID) FieldDecl(Field, nullptr, SourceLocation(),
                                SourceLocation(), nullptr, QualType(), nullptr,
                                nullptr, false, ICIS_NoInit);
@@ -4863,7 +4863,7 @@ EnumDecl *EnumDecl::Create(ASTContext &C, DeclContext *DC,
   return Enum;
 }
 
-EnumDecl *EnumDecl::CreateDeserialized(ASTContext &C, unsigned ID) {
+EnumDecl *EnumDecl::CreateDeserialized(ASTContext &C, Decl::DeclID ID) {
   EnumDecl *Enum =
       new (C, ID) EnumDecl(C, nullptr, SourceLocation(), SourceLocation(),
                            nullptr, nullptr, false, false, false);
@@ -5025,7 +5025,7 @@ RecordDecl *RecordDecl::Create(const ASTContext &C, TagKind TK, DeclContext *DC,
   return R;
 }
 
-RecordDecl *RecordDecl::CreateDeserialized(const ASTContext &C, unsigned ID) {
+RecordDecl *RecordDecl::CreateDeserialized(const ASTContext &C, Decl::DeclID ID) {
   RecordDecl *R = new (C, ID)
       RecordDecl(Record, TagTypeKind::Struct, C, nullptr, SourceLocation(),
                  SourceLocation(), nullptr, nullptr);
@@ -5297,7 +5297,7 @@ PragmaCommentDecl *PragmaCommentDecl::Create(const ASTContext &C,
 }
 
 PragmaCommentDecl *PragmaCommentDecl::CreateDeserialized(ASTContext &C,
-                                                         unsigned ID,
+                                                         Decl::DeclID ID,
                                                          unsigned ArgSize) {
   return new (C, ID, additionalSizeToAlloc<char>(ArgSize + 1))
       PragmaCommentDecl(nullptr, SourceLocation(), PCK_Unknown);
@@ -5322,7 +5322,7 @@ PragmaDetectMismatchDecl::Create(const ASTContext &C, TranslationUnitDecl *DC,
 }
 
 PragmaDetectMismatchDecl *
-PragmaDetectMismatchDecl::CreateDeserialized(ASTContext &C, unsigned ID,
+PragmaDetectMismatchDecl::CreateDeserialized(ASTContext &C, Decl::DeclID ID,
                                              unsigned NameValueSize) {
   return new (C, ID, additionalSizeToAlloc<char>(NameValueSize + 1))
       PragmaDetectMismatchDecl(nullptr, SourceLocation(), 0);
@@ -5349,7 +5349,7 @@ LabelDecl *LabelDecl::Create(ASTContext &C, DeclContext *DC,
   return new (C, DC) LabelDecl(DC, IdentL, II, nullptr, GnuLabelL);
 }
 
-LabelDecl *LabelDecl::CreateDeserialized(ASTContext &C, unsigned ID) {
+LabelDecl *LabelDecl::CreateDeserialized(ASTContext &C, Decl::DeclID ID) {
   return new (C, ID) LabelDecl(nullptr, SourceLocation(), nullptr, nullptr,
                                SourceLocation());
 }
@@ -5390,7 +5390,7 @@ ImplicitParamDecl *ImplicitParamDecl::Create(ASTContext &C, QualType Type,
 }
 
 ImplicitParamDecl *ImplicitParamDecl::CreateDeserialized(ASTContext &C,
-                                                         unsigned ID) {
+                                                         Decl::DeclID ID) {
   return new (C, ID) ImplicitParamDecl(C, QualType(), ImplicitParamKind::Other);
 }
 
@@ -5408,7 +5408,7 @@ FunctionDecl::Create(ASTContext &C, DeclContext *DC, SourceLocation StartLoc,
   return New;
 }
 
-FunctionDecl *FunctionDecl::CreateDeserialized(ASTContext &C, unsigned ID) {
+FunctionDecl *FunctionDecl::CreateDeserialized(ASTContext &C, Decl::DeclID ID) {
   return new (C, ID) FunctionDecl(
       Function, C, nullptr, SourceLocation(), DeclarationNameInfo(), QualType(),
       nullptr, SC_None, false, false, ConstexprSpecKind::Unspecified, nullptr);
@@ -5418,7 +5418,7 @@ BlockDecl *BlockDecl::Create(ASTContext &C, DeclContext *DC, SourceLocation L) {
   return new (C, DC) BlockDecl(DC, L);
 }
 
-BlockDecl *BlockDecl::CreateDeserialized(ASTContext &C, unsigned ID) {
+BlockDecl *BlockDecl::CreateDeserialized(ASTContext &C, Decl::DeclID ID) {
   return new (C, ID) BlockDecl(nullptr, SourceLocation());
 }
 
@@ -5432,7 +5432,7 @@ CapturedDecl *CapturedDecl::Create(ASTContext &C, DeclContext *DC,
       CapturedDecl(DC, NumParams);
 }
 
-CapturedDecl *CapturedDecl::CreateDeserialized(ASTContext &C, unsigned ID,
+CapturedDecl *CapturedDecl::CreateDeserialized(ASTContext &C, Decl::DeclID ID,
                                                unsigned NumParams) {
   return new (C, ID, additionalSizeToAlloc<ImplicitParamDecl *>(NumParams))
       CapturedDecl(nullptr, NumParams);
@@ -5459,7 +5459,7 @@ EnumConstantDecl *EnumConstantDecl::Create(ASTContext &C, EnumDecl *CD,
 }
 
 EnumConstantDecl *
-EnumConstantDecl::CreateDeserialized(ASTContext &C, unsigned ID) {
+EnumConstantDecl::CreateDeserialized(ASTContext &C, Decl::DeclID ID) {
   return new (C, ID) EnumConstantDecl(C, nullptr, SourceLocation(), nullptr,
                                       QualType(), nullptr, llvm::APSInt());
 }
@@ -5486,7 +5486,7 @@ IndirectFieldDecl::Create(ASTContext &C, DeclContext *DC, SourceLocation L,
 }
 
 IndirectFieldDecl *IndirectFieldDecl::CreateDeserialized(ASTContext &C,
-                                                         unsigned ID) {
+                                                         Decl::DeclID ID) {
   return new (C, ID)
       IndirectFieldDecl(C, nullptr, SourceLocation(), DeclarationName(),
                         QualType(), std::nullopt);
@@ -5547,7 +5547,7 @@ bool TypedefNameDecl::isTransparentTagSlow() const {
   return isTransparent;
 }
 
-TypedefDecl *TypedefDecl::CreateDeserialized(ASTContext &C, unsigned ID) {
+TypedefDecl *TypedefDecl::CreateDeserialized(ASTContext &C, Decl::DeclID ID) {
   return new (C, ID) TypedefDecl(C, nullptr, SourceLocation(), SourceLocation(),
                                  nullptr, nullptr);
 }
@@ -5560,7 +5560,7 @@ TypeAliasDecl *TypeAliasDecl::Create(ASTContext &C, DeclContext *DC,
   return new (C, DC) TypeAliasDecl(C, DC, StartLoc, IdLoc, Id, TInfo);
 }
 
-TypeAliasDecl *TypeAliasDecl::CreateDeserialized(ASTContext &C, unsigned ID) {
+TypeAliasDecl *TypeAliasDecl::CreateDeserialized(ASTContext &C, Decl::DeclID ID) {
   return new (C, ID) TypeAliasDecl(C, nullptr, SourceLocation(),
                                    SourceLocation(), nullptr, nullptr);
 }
@@ -5591,7 +5591,7 @@ FileScopeAsmDecl *FileScopeAsmDecl::Create(ASTContext &C, DeclContext *DC,
 }
 
 FileScopeAsmDecl *FileScopeAsmDecl::CreateDeserialized(ASTContext &C,
-                                                       unsigned ID) {
+                                                       Decl::DeclID ID) {
   return new (C, ID) FileScopeAsmDecl(nullptr, nullptr, SourceLocation(),
                                       SourceLocation());
 }
@@ -5609,7 +5609,7 @@ TopLevelStmtDecl *TopLevelStmtDecl::Create(ASTContext &C, Stmt *Statement) {
 }
 
 TopLevelStmtDecl *TopLevelStmtDecl::CreateDeserialized(ASTContext &C,
-                                                       unsigned ID) {
+                                                       Decl::DeclID ID) {
   return new (C, ID)
       TopLevelStmtDecl(/*DC=*/nullptr, SourceLocation(), /*S=*/nullptr);
 }
@@ -5630,7 +5630,7 @@ EmptyDecl *EmptyDecl::Create(ASTContext &C, DeclContext *DC, SourceLocation L) {
   return new (C, DC) EmptyDecl(DC, L);
 }
 
-EmptyDecl *EmptyDecl::CreateDeserialized(ASTContext &C, unsigned ID) {
+EmptyDecl *EmptyDecl::CreateDeserialized(ASTContext &C, Decl::DeclID ID) {
   return new (C, ID) EmptyDecl(nullptr, SourceLocation());
 }
 
@@ -5663,7 +5663,7 @@ HLSLBufferDecl *HLSLBufferDecl::Create(ASTContext &C,
   return Result;
 }
 
-HLSLBufferDecl *HLSLBufferDecl::CreateDeserialized(ASTContext &C, unsigned ID) {
+HLSLBufferDecl *HLSLBufferDecl::CreateDeserialized(ASTContext &C, Decl::DeclID ID) {
   return new (C, ID) HLSLBufferDecl(nullptr, false, SourceLocation(), nullptr,
                                     SourceLocation(), SourceLocation());
 }
@@ -5719,7 +5719,7 @@ ImportDecl *ImportDecl::CreateImplicit(ASTContext &C, DeclContext *DC,
   return Import;
 }
 
-ImportDecl *ImportDecl::CreateDeserialized(ASTContext &C, unsigned ID,
+ImportDecl *ImportDecl::CreateDeserialized(ASTContext &C, Decl::DeclID ID,
                                            unsigned NumLocations) {
   return new (C, ID, additionalSizeToAlloc<SourceLocation>(NumLocations))
       ImportDecl(EmptyShell());
@@ -5752,6 +5752,6 @@ ExportDecl *ExportDecl::Create(ASTContext &C, DeclContext *DC,
   return new (C, DC) ExportDecl(DC, ExportLoc);
 }
 
-ExportDecl *ExportDecl::CreateDeserialized(ASTContext &C, unsigned ID) {
+ExportDecl *ExportDecl::CreateDeserialized(ASTContext &C, Decl::DeclID ID) {
   return new (C, ID) ExportDecl(nullptr, SourceLocation());
 }
diff --git a/clang/lib/AST/DeclBase.cpp b/clang/lib/AST/DeclBase.cpp
index 4349263..7cb6b31 100644
--- a/clang/lib/AST/DeclBase.cpp
+++ b/clang/lib/AST/DeclBase.cpp
@@ -71,7 +71,7 @@ void Decl::updateOutOfDate(IdentifierInfo &II) const {
 #include "clang/AST/DeclNodes.inc"
 
 void *Decl::operator new(std::size_t Size, const ASTContext &Context,
-                         unsigned ID, std::size_t Extra) {
+                         Decl::DeclID ID, std::size_t Extra) {
   // Allocate an extra 8 bytes worth of storage, which ensures that the
   // resulting pointer will still be 8-byte aligned.
   static_assert(sizeof(unsigned) * 2 >= alignof(Decl),
diff --git a/clang/lib/AST/DeclCXX.cpp b/clang/lib/AST/DeclCXX.cpp
index 00cc857..426c526 100644
--- a/clang/lib/AST/DeclCXX.cpp
+++ b/clang/lib/AST/DeclCXX.cpp
@@ -57,7 +57,7 @@ using namespace clang;
 
 void AccessSpecDecl::anchor() {}
 
-AccessSpecDecl *AccessSpecDecl::CreateDeserialized(ASTContext &C, unsigned ID) {
+AccessSpecDecl *AccessSpecDecl::CreateDeserialized(ASTContext &C, Decl::DeclID ID) {
   return new (C, ID) AccessSpecDecl(EmptyShell());
 }
 
@@ -161,7 +161,7 @@ CXXRecordDecl::CreateLambda(const ASTContext &C, DeclContext *DC,
 }
 
 CXXRecordDecl *
-CXXRecordDecl::CreateDeserialized(const ASTContext &C, unsigned ID) {
+CXXRecordDecl::CreateDeserialized(const ASTContext &C, Decl::DeclID ID) {
   auto *R = new (C, ID)
       CXXRecordDecl(CXXRecord, TagTypeKind::Struct, C, nullptr,
                     SourceLocation(), SourceLocation(), nullptr, nullptr);
@@ -2163,7 +2163,7 @@ CXXDeductionGuideDecl *CXXDeductionGuideDecl::Create(
 }
 
 CXXDeductionGuideDecl *CXXDeductionGuideDecl::CreateDeserialized(ASTContext &C,
-                                                                 unsigned ID) {
+                                                                 Decl::DeclID ID) {
   return new (C, ID) CXXDeductionGuideDecl(
       C, nullptr, SourceLocation(), ExplicitSpecifier(), DeclarationNameInfo(),
       QualType(), nullptr, SourceLocation(), nullptr,
@@ -2176,7 +2176,7 @@ RequiresExprBodyDecl *RequiresExprBodyDecl::Create(
 }
 
 RequiresExprBodyDecl *RequiresExprBodyDecl::CreateDeserialized(ASTContext &C,
-                                                               unsigned ID) {
+                                                               Decl::DeclID ID) {
   return new (C, ID) RequiresExprBodyDecl(C, nullptr, SourceLocation());
 }
 
@@ -2281,7 +2281,7 @@ CXXMethodDecl::Create(ASTContext &C, CXXRecordDecl *RD, SourceLocation StartLoc,
       isInline, ConstexprKind, EndLocation, TrailingRequiresClause);
 }
 
-CXXMethodDecl *CXXMethodDecl::CreateDeserialized(ASTContext &C, unsigned ID) {
+CXXMethodDecl *CXXMethodDecl::CreateDeserialized(ASTContext &C, Decl::DeclID ID) {
   return new (C, ID) CXXMethodDecl(
       CXXMethod, C, nullptr, SourceLocation(), DeclarationNameInfo(),
       QualType(), nullptr, SC_None, false, false,
@@ -2699,7 +2699,7 @@ CXXConstructorDecl::CXXConstructorDecl(
 void CXXConstructorDecl::anchor() {}
 
 CXXConstructorDecl *CXXConstructorDecl::CreateDeserialized(ASTContext &C,
-                                                           unsigned ID,
+                                                           Decl::DeclID ID,
                                                            uint64_t AllocKind) {
   bool hasTrailingExplicit = static_cast<bool>(AllocKind & TAKHasTailExplicit);
   bool isInheritingConstructor =
@@ -2846,7 +2846,7 @@ bool CXXConstructorDecl::isSpecializationCopyingObject() const {
 void CXXDestructorDecl::anchor() {}
 
 CXXDestructorDecl *
-CXXDestructorDecl::CreateDeserialized(ASTContext &C, unsigned ID) {
+CXXDestructorDecl::CreateDeserialized(ASTContext &C, Decl::DeclID ID) {
   return new (C, ID) CXXDestructorDecl(
       C, nullptr, SourceLocation(), DeclarationNameInfo(), QualType(), nullptr,
       false, false, false, ConstexprSpecKind::Unspecified, nullptr);
@@ -2878,7 +2878,7 @@ void CXXDestructorDecl::setOperatorDelete(FunctionDecl *OD, Expr *ThisArg) {
 void CXXConversionDecl::anchor() {}
 
 CXXConversionDecl *
-CXXConversionDecl::CreateDeserialized(ASTContext &C, unsigned ID) {
+CXXConversionDecl::CreateDeserialized(ASTContext &C, Decl::DeclID ID) {
   return new (C, ID) CXXConversionDecl(
       C, nullptr, SourceLocation(), DeclarationNameInfo(), QualType(), nullptr,
       false, false, ExplicitSpecifier(), ConstexprSpecKind::Unspecified,
@@ -2924,7 +2924,7 @@ LinkageSpecDecl *LinkageSpecDecl::Create(ASTContext &C, DeclContext *DC,
 }
 
 LinkageSpecDecl *LinkageSpecDecl::CreateDeserialized(ASTContext &C,
-                                                     unsigned ID) {
+                                                     Decl::DeclID ID) {
   return new (C, ID)
       LinkageSpecDecl(nullptr, SourceLocation(), SourceLocation(),
                       LinkageSpecLanguageIDs::C, false);
@@ -2946,7 +2946,7 @@ UsingDirectiveDecl *UsingDirectiveDecl::Create(ASTContext &C, DeclContext *DC,
 }
 
 UsingDirectiveDecl *UsingDirectiveDecl::CreateDeserialized(ASTContext &C,
-                                                           unsigned ID) {
+                                                           Decl::DeclID ID) {
   return new (C, ID) UsingDirectiveDecl(nullptr, SourceLocation(),
                                         SourceLocation(),
                                         NestedNameSpecifierLoc(),
@@ -2985,7 +2985,7 @@ NamespaceDecl *NamespaceDecl::Create(ASTContext &C, DeclContext *DC,
       NamespaceDecl(C, DC, Inline, StartLoc, IdLoc, Id, PrevDecl, Nested);
 }
 
-NamespaceDecl *NamespaceDecl::CreateDeserialized(ASTContext &C, unsigned ID) {
+NamespaceDecl *NamespaceDecl::CreateDeserialized(ASTContext &C, Decl::DeclID ID) {
   return new (C, ID) NamespaceDecl(C, nullptr, false, SourceLocation(),
                                    SourceLocation(), nullptr, nullptr, false);
 }
@@ -3047,7 +3047,7 @@ NamespaceAliasDecl *NamespaceAliasDecl::Create(ASTContext &C, DeclContext *DC,
 }
 
 NamespaceAliasDecl *
-NamespaceAliasDecl::CreateDeserialized(ASTContext &C, unsigned ID) {
+NamespaceAliasDecl::CreateDeserialized(ASTContext &C, Decl::DeclID ID) {
   return new (C, ID) NamespaceAliasDecl(C, nullptr, SourceLocation(),
                                         SourceLocation(), nullptr,
                                         NestedNameSpecifierLoc(),
@@ -3103,7 +3103,7 @@ UsingShadowDecl::UsingShadowDecl(Kind K, ASTContext &C, EmptyShell Empty)
       redeclarable_base(C) {}
 
 UsingShadowDecl *
-UsingShadowDecl::CreateDeserialized(ASTContext &C, unsigned ID) {
+UsingShadowDecl::CreateDeserialized(ASTContext &C, Decl::DeclID ID) {
   return new (C, ID) UsingShadowDecl(UsingShadow, C, EmptyShell());
 }
 
@@ -3126,7 +3126,7 @@ ConstructorUsingShadowDecl::Create(ASTContext &C, DeclContext *DC,
 }
 
 ConstructorUsingShadowDecl *
-ConstructorUsingShadowDecl::CreateDeserialized(ASTContext &C, unsigned ID) {
+ConstructorUsingShadowDecl::CreateDeserialized(ASTContext &C, Decl::DeclID ID) {
   return new (C, ID) ConstructorUsingShadowDecl(C, EmptyShell());
 }
 
@@ -3174,7 +3174,7 @@ UsingDecl *UsingDecl::Create(ASTContext &C, DeclContext *DC, SourceLocation UL,
   return new (C, DC) UsingDecl(DC, UL, QualifierLoc, NameInfo, HasTypename);
 }
 
-UsingDecl *UsingDecl::CreateDeserialized(ASTContext &C, unsigned ID) {
+UsingDecl *UsingDecl::CreateDeserialized(ASTContext &C, Decl::DeclID ID) {
   return new (C, ID) UsingDecl(nullptr, SourceLocation(),
                                NestedNameSpecifierLoc(), DeclarationNameInfo(),
                                false);
@@ -3198,7 +3198,7 @@ UsingEnumDecl *UsingEnumDecl::Create(ASTContext &C, DeclContext *DC,
       UsingEnumDecl(DC, EnumType->getType()->getAsTagDecl()->getDeclName(), UL, EL, NL, EnumType);
 }
 
-UsingEnumDecl *UsingEnumDecl::CreateDeserialized(ASTContext &C, unsigned ID) {
+UsingEnumDecl *UsingEnumDecl::CreateDeserialized(ASTContext &C, Decl::DeclID ID) {
   return new (C, ID)
       UsingEnumDecl(nullptr, DeclarationName(), SourceLocation(),
                     SourceLocation(), SourceLocation(), nullptr);
@@ -3217,7 +3217,7 @@ UsingPackDecl *UsingPackDecl::Create(ASTContext &C, DeclContext *DC,
   return new (C, DC, Extra) UsingPackDecl(DC, InstantiatedFrom, UsingDecls);
 }
 
-UsingPackDecl *UsingPackDecl::CreateDeserialized(ASTContext &C, unsigned ID,
+UsingPackDecl *UsingPackDecl::CreateDeserialized(ASTContext &C, Decl::DeclID ID,
                                                  unsigned NumExpansions) {
   size_t Extra = additionalSizeToAlloc<NamedDecl *>(NumExpansions);
   auto *Result =
@@ -3243,7 +3243,7 @@ UnresolvedUsingValueDecl::Create(ASTContext &C, DeclContext *DC,
 }
 
 UnresolvedUsingValueDecl *
-UnresolvedUsingValueDecl::CreateDeserialized(ASTContext &C, unsigned ID) {
+UnresolvedUsingValueDecl::CreateDeserialized(ASTContext &C, Decl::DeclID ID) {
   return new (C, ID) UnresolvedUsingValueDecl(nullptr, QualType(),
                                               SourceLocation(),
                                               NestedNameSpecifierLoc(),
@@ -3273,7 +3273,7 @@ UnresolvedUsingTypenameDecl::Create(ASTContext &C, DeclContext *DC,
 }
 
 UnresolvedUsingTypenameDecl *
-UnresolvedUsingTypenameDecl::CreateDeserialized(ASTContext &C, unsigned ID) {
+UnresolvedUsingTypenameDecl::CreateDeserialized(ASTContext &C, Decl::DeclID ID) {
   return new (C, ID) UnresolvedUsingTypenameDecl(
       nullptr, SourceLocation(), SourceLocation(), NestedNameSpecifierLoc(),
       SourceLocation(), nullptr, SourceLocation());
@@ -3286,7 +3286,7 @@ UnresolvedUsingIfExistsDecl::Create(ASTContext &Ctx, DeclContext *DC,
 }
 
 UnresolvedUsingIfExistsDecl *
-UnresolvedUsingIfExistsDecl::CreateDeserialized(ASTContext &Ctx, unsigned ID) {
+UnresolvedUsingIfExistsDecl::CreateDeserialized(ASTContext &Ctx, Decl::DeclID ID) {
   return new (Ctx, ID)
       UnresolvedUsingIfExistsDecl(nullptr, SourceLocation(), DeclarationName());
 }
@@ -3310,7 +3310,7 @@ StaticAssertDecl *StaticAssertDecl::Create(ASTContext &C, DeclContext *DC,
 }
 
 StaticAssertDecl *StaticAssertDecl::CreateDeserialized(ASTContext &C,
-                                                       unsigned ID) {
+                                                       Decl::DeclID ID) {
   return new (C, ID) StaticAssertDecl(nullptr, SourceLocation(), nullptr,
                                       nullptr, SourceLocation(), false);
 }
@@ -3332,7 +3332,7 @@ BindingDecl *BindingDecl::Create(ASTContext &C, DeclContext *DC,
   return new (C, DC) BindingDecl(DC, IdLoc, Id);
 }
 
-BindingDecl *BindingDecl::CreateDeserialized(ASTContext &C, unsigned ID) {
+BindingDecl *BindingDecl::CreateDeserialized(ASTContext &C, Decl::DeclID ID) {
   return new (C, ID) BindingDecl(nullptr, SourceLocation(), nullptr);
 }
 
@@ -3363,7 +3363,7 @@ DecompositionDecl *DecompositionDecl::Create(ASTContext &C, DeclContext *DC,
 }
 
 DecompositionDecl *DecompositionDecl::CreateDeserialized(ASTContext &C,
-                                                         unsigned ID,
+                                                         Decl::DeclID ID,
                                                          unsigned NumBindings) {
   size_t Extra = additionalSizeToAlloc<BindingDecl *>(NumBindings);
   auto *Result = new (C, ID, Extra)
@@ -3402,7 +3402,7 @@ MSPropertyDecl *MSPropertyDecl::Create(ASTContext &C, DeclContext *DC,
 }
 
 MSPropertyDecl *MSPropertyDecl::CreateDeserialized(ASTContext &C,
-                                                   unsigned ID) {
+                                                   Decl::DeclID ID) {
   return new (C, ID) MSPropertyDecl(nullptr, SourceLocation(),
                                     DeclarationName(), QualType(), nullptr,
                                     SourceLocation(), nullptr, nullptr);
@@ -3419,7 +3419,7 @@ MSGuidDecl *MSGuidDecl::Create(const ASTContext &C, QualType T, Parts P) {
   return new (C, DC) MSGuidDecl(DC, T, P);
 }
 
-MSGuidDecl *MSGuidDecl::CreateDeserialized(ASTContext &C, unsigned ID) {
+MSGuidDecl *MSGuidDecl::CreateDeserialized(ASTContext &C, Decl::DeclID ID) {
   return new (C, ID) MSGuidDecl(nullptr, QualType(), Parts());
 }
 
@@ -3529,7 +3529,7 @@ UnnamedGlobalConstantDecl::Create(const ASTContext &C, QualType T,
 }
 
 UnnamedGlobalConstantDecl *
-UnnamedGlobalConstantDecl::CreateDeserialized(ASTContext &C, unsigned ID) {
+UnnamedGlobalConstantDecl::CreateDeserialized(ASTContext &C, Decl::DeclID ID) {
   return new (C, ID)
       UnnamedGlobalConstantDecl(C, nullptr, QualType(), APValue());
 }
diff --git a/clang/lib/AST/DeclFriend.cpp b/clang/lib/AST/DeclFriend.cpp
index 8ec1dea8..1fabf8a 100644
--- a/clang/lib/AST/DeclFriend.cpp
+++ b/clang/lib/AST/DeclFriend.cpp
@@ -62,7 +62,7 @@ FriendDecl *FriendDecl::Create(ASTContext &C, DeclContext *DC,
   return FD;
 }
 
-FriendDecl *FriendDecl::CreateDeserialized(ASTContext &C, unsigned ID,
+FriendDecl *FriendDecl::CreateDeserialized(ASTContext &C, Decl::DeclID ID,
                                            unsigned FriendTypeNumTPLists) {
   std::size_t Extra =
       additionalSizeToAlloc<TemplateParameterList *>(FriendTypeNumTPLists);
diff --git a/clang/lib/AST/DeclObjC.cpp b/clang/lib/AST/DeclObjC.cpp
index 32c1493..d4275ee 100644
--- a/clang/lib/AST/DeclObjC.cpp
+++ b/clang/lib/AST/DeclObjC.cpp
@@ -862,7 +862,7 @@ ObjCMethodDecl *ObjCMethodDecl::Create(
       isImplicitlyDeclared, isDefined, impControl, HasRelatedResultType);
 }
 
-ObjCMethodDecl *ObjCMethodDecl::CreateDeserialized(ASTContext &C, unsigned ID) {
+ObjCMethodDecl *ObjCMethodDecl::CreateDeserialized(ASTContext &C, Decl::DeclID ID) {
   return new (C, ID) ObjCMethodDecl(SourceLocation(), SourceLocation(),
                                     Selector(), QualType(), nullptr, nullptr);
 }
@@ -1486,7 +1486,7 @@ ObjCTypeParamDecl *ObjCTypeParamDecl::Create(ASTContext &ctx, DeclContext *dc,
 }
 
 ObjCTypeParamDecl *ObjCTypeParamDecl::CreateDeserialized(ASTContext &ctx,
-                                                         unsigned ID) {
+                                                         Decl::DeclID ID) {
   return new (ctx, ID) ObjCTypeParamDecl(ctx, nullptr,
                                          ObjCTypeParamVariance::Invariant,
                                          SourceLocation(), 0, SourceLocation(),
@@ -1551,7 +1551,7 @@ ObjCInterfaceDecl *ObjCInterfaceDecl::Create(
 }
 
 ObjCInterfaceDecl *ObjCInterfaceDecl::CreateDeserialized(const ASTContext &C,
-                                                         unsigned ID) {
+                                                         Decl::DeclID ID) {
   auto *Result = new (C, ID)
       ObjCInterfaceDecl(C, nullptr, SourceLocation(), nullptr, nullptr,
                         SourceLocation(), nullptr, false);
@@ -1865,7 +1865,7 @@ ObjCIvarDecl *ObjCIvarDecl::Create(ASTContext &C, ObjCContainerDecl *DC,
                                   synthesized);
 }
 
-ObjCIvarDecl *ObjCIvarDecl::CreateDeserialized(ASTContext &C, unsigned ID) {
+ObjCIvarDecl *ObjCIvarDecl::CreateDeserialized(ASTContext &C, Decl::DeclID ID) {
   return new (C, ID) ObjCIvarDecl(nullptr, SourceLocation(), SourceLocation(),
                                   nullptr, QualType(), nullptr,
                                   ObjCIvarDecl::None, nullptr, false);
@@ -1914,7 +1914,7 @@ ObjCAtDefsFieldDecl
 }
 
 ObjCAtDefsFieldDecl *ObjCAtDefsFieldDecl::CreateDeserialized(ASTContext &C,
-                                                             unsigned ID) {
+                                                             Decl::DeclID ID) {
   return new (C, ID) ObjCAtDefsFieldDecl(nullptr, SourceLocation(),
                                          SourceLocation(), nullptr, QualType(),
                                          nullptr);
@@ -1949,7 +1949,7 @@ ObjCProtocolDecl *ObjCProtocolDecl::Create(ASTContext &C, DeclContext *DC,
 }
 
 ObjCProtocolDecl *ObjCProtocolDecl::CreateDeserialized(ASTContext &C,
-                                                       unsigned ID) {
+                                                       Decl::DeclID ID) {
   ObjCProtocolDecl *Result =
       new (C, ID) ObjCProtocolDecl(C, nullptr, nullptr, SourceLocation(),
                                    SourceLocation(), nullptr);
@@ -2148,7 +2148,7 @@ ObjCCategoryDecl *ObjCCategoryDecl::Create(
 }
 
 ObjCCategoryDecl *ObjCCategoryDecl::CreateDeserialized(ASTContext &C,
-                                                       unsigned ID) {
+                                                       Decl::DeclID ID) {
   return new (C, ID) ObjCCategoryDecl(nullptr, SourceLocation(),
                                       SourceLocation(), SourceLocation(),
                                       nullptr, nullptr, nullptr);
@@ -2189,7 +2189,7 @@ ObjCCategoryImplDecl *ObjCCategoryImplDecl::Create(
 }
 
 ObjCCategoryImplDecl *ObjCCategoryImplDecl::CreateDeserialized(ASTContext &C,
-                                                               unsigned ID) {
+                                                               Decl::DeclID ID) {
   return new (C, ID) ObjCCategoryImplDecl(nullptr, nullptr, nullptr,
                                           SourceLocation(), SourceLocation(),
                                           SourceLocation());
@@ -2296,7 +2296,7 @@ ObjCImplementationDecl::Create(ASTContext &C, DeclContext *DC,
 }
 
 ObjCImplementationDecl *
-ObjCImplementationDecl::CreateDeserialized(ASTContext &C, unsigned ID) {
+ObjCImplementationDecl::CreateDeserialized(ASTContext &C, Decl::DeclID ID) {
   return new (C, ID) ObjCImplementationDecl(nullptr, nullptr, nullptr,
                                             SourceLocation(), SourceLocation());
 }
@@ -2339,7 +2339,7 @@ ObjCCompatibleAliasDecl::Create(ASTContext &C, DeclContext *DC,
 }
 
 ObjCCompatibleAliasDecl *
-ObjCCompatibleAliasDecl::CreateDeserialized(ASTContext &C, unsigned ID) {
+ObjCCompatibleAliasDecl::CreateDeserialized(ASTContext &C, Decl::DeclID ID) {
   return new (C, ID) ObjCCompatibleAliasDecl(nullptr, SourceLocation(),
                                              nullptr, nullptr);
 }
@@ -2360,7 +2360,7 @@ ObjCPropertyDecl::Create(ASTContext &C, DeclContext *DC, SourceLocation L,
 }
 
 ObjCPropertyDecl *ObjCPropertyDecl::CreateDeserialized(ASTContext &C,
-                                                       unsigned ID) {
+                                                       Decl::DeclID ID) {
   return new (C, ID) ObjCPropertyDecl(nullptr, SourceLocation(), nullptr,
                                       SourceLocation(), SourceLocation(),
                                       QualType(), nullptr, None);
@@ -2393,7 +2393,7 @@ ObjCPropertyImplDecl *ObjCPropertyImplDecl::Create(ASTContext &C,
 }
 
 ObjCPropertyImplDecl *ObjCPropertyImplDecl::CreateDeserialized(ASTContext &C,
-                                                               unsigned ID) {
+                                                               Decl::DeclID ID) {
   return new (C, ID) ObjCPropertyImplDecl(nullptr, SourceLocation(),
                                           SourceLocation(), nullptr, Dynamic,
                                           nullptr, SourceLocation());
diff --git a/clang/lib/AST/DeclOpenMP.cpp b/clang/lib/AST/DeclOpenMP.cpp
index ac5780f8..b178a15 100644
--- a/clang/lib/AST/DeclOpenMP.cpp
+++ b/clang/lib/AST/DeclOpenMP.cpp
@@ -36,7 +36,7 @@ OMPThreadPrivateDecl *OMPThreadPrivateDecl::Create(ASTContext &C,
 }
 
 OMPThreadPrivateDecl *OMPThreadPrivateDecl::CreateDeserialized(ASTContext &C,
-                                                               unsigned ID,
+                                                               Decl::DeclID ID,
                                                                unsigned N) {
   return OMPDeclarativeDirective::createEmptyDirective<OMPThreadPrivateDecl>(
       C, ID, 0, N);
@@ -63,7 +63,7 @@ OMPAllocateDecl *OMPAllocateDecl::Create(ASTContext &C, DeclContext *DC,
   return D;
 }
 
-OMPAllocateDecl *OMPAllocateDecl::CreateDeserialized(ASTContext &C, unsigned ID,
+OMPAllocateDecl *OMPAllocateDecl::CreateDeserialized(ASTContext &C, Decl::DeclID ID,
                                                      unsigned NVars,
                                                      unsigned NClauses) {
   return OMPDeclarativeDirective::createEmptyDirective<OMPAllocateDecl>(
@@ -89,7 +89,7 @@ OMPRequiresDecl *OMPRequiresDecl::Create(ASTContext &C, DeclContext *DC,
                                                                    L);
 }
 
-OMPRequiresDecl *OMPRequiresDecl::CreateDeserialized(ASTContext &C, unsigned ID,
+OMPRequiresDecl *OMPRequiresDecl::CreateDeserialized(ASTContext &C, Decl::DeclID ID,
                                                      unsigned N) {
   return OMPDeclarativeDirective::createEmptyDirective<OMPRequiresDecl>(
       C, ID, N, 0, SourceLocation());
@@ -117,7 +117,7 @@ OMPDeclareReductionDecl *OMPDeclareReductionDecl::Create(
 }
 
 OMPDeclareReductionDecl *
-OMPDeclareReductionDecl::CreateDeserialized(ASTContext &C, unsigned ID) {
+OMPDeclareReductionDecl::CreateDeserialized(ASTContext &C, Decl::DeclID ID) {
   return new (C, ID) OMPDeclareReductionDecl(
       OMPDeclareReduction, /*DC=*/nullptr, SourceLocation(), DeclarationName(),
       QualType(), /*PrevDeclInScope=*/nullptr);
@@ -148,7 +148,7 @@ OMPDeclareMapperDecl *OMPDeclareMapperDecl::Create(
 }
 
 OMPDeclareMapperDecl *OMPDeclareMapperDecl::CreateDeserialized(ASTContext &C,
-                                                               unsigned ID,
+                                                               Decl::DeclID ID,
                                                                unsigned N) {
   return OMPDeclarativeDirective::createEmptyDirective<OMPDeclareMapperDecl>(
       C, ID, N, 1, SourceLocation(), DeclarationName(), QualType(),
@@ -179,7 +179,7 @@ OMPCapturedExprDecl *OMPCapturedExprDecl::Create(ASTContext &C, DeclContext *DC,
 }
 
 OMPCapturedExprDecl *OMPCapturedExprDecl::CreateDeserialized(ASTContext &C,
-                                                             unsigned ID) {
+                                                             Decl::DeclID ID) {
   return new (C, ID) OMPCapturedExprDecl(C, nullptr, nullptr, QualType(),
                                          /*TInfo=*/nullptr, SourceLocation());
 }
diff --git a/clang/lib/AST/DeclTemplate.cpp b/clang/lib/AST/DeclTemplate.cpp
index 5aa2484..0ba271c 100644
--- a/clang/lib/AST/DeclTemplate.cpp
+++ b/clang/lib/AST/DeclTemplate.cpp
@@ -418,7 +418,7 @@ FunctionTemplateDecl::Create(ASTContext &C, DeclContext *DC, SourceLocation L,
 }
 
 FunctionTemplateDecl *FunctionTemplateDecl::CreateDeserialized(ASTContext &C,
-                                                               unsigned ID) {
+                                                               Decl::DeclID ID) {
   return new (C, ID) FunctionTemplateDecl(C, nullptr, SourceLocation(),
                                           DeclarationName(), nullptr, nullptr);
 }
@@ -503,7 +503,7 @@ ClassTemplateDecl *ClassTemplateDecl::Create(ASTContext &C, DeclContext *DC,
 }
 
 ClassTemplateDecl *ClassTemplateDecl::CreateDeserialized(ASTContext &C,
-                                                         unsigned ID) {
+                                                         Decl::DeclID ID) {
   return new (C, ID) ClassTemplateDecl(C, nullptr, SourceLocation(),
                                        DeclarationName(), nullptr, nullptr);
 }
@@ -652,14 +652,14 @@ TemplateTypeParmDecl *TemplateTypeParmDecl::Create(
 }
 
 TemplateTypeParmDecl *
-TemplateTypeParmDecl::CreateDeserialized(const ASTContext &C, unsigned ID) {
+TemplateTypeParmDecl::CreateDeserialized(const ASTContext &C, Decl::DeclID ID) {
   return new (C, ID)
       TemplateTypeParmDecl(nullptr, SourceLocation(), SourceLocation(), nullptr,
                            false, false, std::nullopt);
 }
 
 TemplateTypeParmDecl *
-TemplateTypeParmDecl::CreateDeserialized(const ASTContext &C, unsigned ID,
+TemplateTypeParmDecl::CreateDeserialized(const ASTContext &C, Decl::DeclID ID,
                                          bool HasTypeConstraint) {
   return new (C, ID,
               additionalSizeToAlloc<TypeConstraint>(HasTypeConstraint ? 1 : 0))
@@ -759,7 +759,7 @@ NonTypeTemplateParmDecl *NonTypeTemplateParmDecl::Create(
 }
 
 NonTypeTemplateParmDecl *
-NonTypeTemplateParmDecl::CreateDeserialized(ASTContext &C, unsigned ID,
+NonTypeTemplateParmDecl::CreateDeserialized(ASTContext &C, Decl::DeclID ID,
                                             bool HasTypeConstraint) {
   return new (C, ID, additionalSizeToAlloc<std::pair<QualType,
                                                      TypeSourceInfo *>,
@@ -770,7 +770,7 @@ NonTypeTemplateParmDecl::CreateDeserialized(ASTContext &C, unsigned ID,
 }
 
 NonTypeTemplateParmDecl *
-NonTypeTemplateParmDecl::CreateDeserialized(ASTContext &C, unsigned ID,
+NonTypeTemplateParmDecl::CreateDeserialized(ASTContext &C, Decl::DeclID ID,
                                             unsigned NumExpandedTypes,
                                             bool HasTypeConstraint) {
   auto *NTTP =
@@ -836,13 +836,13 @@ TemplateTemplateParmDecl::Create(const ASTContext &C, DeclContext *DC,
 }
 
 TemplateTemplateParmDecl *
-TemplateTemplateParmDecl::CreateDeserialized(ASTContext &C, unsigned ID) {
+TemplateTemplateParmDecl::CreateDeserialized(ASTContext &C, Decl::DeclID ID) {
   return new (C, ID) TemplateTemplateParmDecl(nullptr, SourceLocation(), 0, 0,
                                               false, nullptr, false, nullptr);
 }
 
 TemplateTemplateParmDecl *
-TemplateTemplateParmDecl::CreateDeserialized(ASTContext &C, unsigned ID,
+TemplateTemplateParmDecl::CreateDeserialized(ASTContext &C, Decl::DeclID ID,
                                              unsigned NumExpansions) {
   auto *TTP =
       new (C, ID, additionalSizeToAlloc<TemplateParameterList *>(NumExpansions))
@@ -949,7 +949,7 @@ ClassTemplateSpecializationDecl::Create(ASTContext &Context, TagKind TK,
 
 ClassTemplateSpecializationDecl *
 ClassTemplateSpecializationDecl::CreateDeserialized(ASTContext &C,
-                                                    unsigned ID) {
+                                                    Decl::DeclID ID) {
   auto *Result =
     new (C, ID) ClassTemplateSpecializationDecl(C, ClassTemplateSpecialization);
   Result->setMayHaveOutOfDateDef(false);
@@ -1036,7 +1036,7 @@ ConceptDecl *ConceptDecl::Create(ASTContext &C, DeclContext *DC,
 }
 
 ConceptDecl *ConceptDecl::CreateDeserialized(ASTContext &C,
-                                             unsigned ID) {
+                                             Decl::DeclID ID) {
   ConceptDecl *Result = new (C, ID) ConceptDecl(nullptr, SourceLocation(),
                                                 DeclarationName(),
                                                 nullptr, nullptr);
@@ -1070,7 +1070,7 @@ ImplicitConceptSpecializationDecl *ImplicitConceptSpecializationDecl::Create(
 
 ImplicitConceptSpecializationDecl *
 ImplicitConceptSpecializationDecl::CreateDeserialized(
-    const ASTContext &C, unsigned ID, unsigned NumTemplateArgs) {
+    const ASTContext &C, Decl::DeclID ID, unsigned NumTemplateArgs) {
   return new (C, ID, additionalSizeToAlloc<TemplateArgument>(NumTemplateArgs))
       ImplicitConceptSpecializationDecl(EmptyShell{}, NumTemplateArgs);
 }
@@ -1133,7 +1133,7 @@ Create(ASTContext &Context, TagKind TK,DeclContext *DC,
 
 ClassTemplatePartialSpecializationDecl *
 ClassTemplatePartialSpecializationDecl::CreateDeserialized(ASTContext &C,
-                                                           unsigned ID) {
+                                                           Decl::DeclID ID) {
   auto *Result = new (C, ID) ClassTemplatePartialSpecializationDecl(C);
   Result->setMayHaveOutOfDateDef(false);
   return Result;
@@ -1160,7 +1160,7 @@ FriendTemplateDecl::Create(ASTContext &Context, DeclContext *DC,
 }
 
 FriendTemplateDecl *FriendTemplateDecl::CreateDeserialized(ASTContext &C,
-                                                           unsigned ID) {
+                                                           Decl::DeclID ID) {
   return new (C, ID) FriendTemplateDecl(EmptyShell());
 }
 
@@ -1180,7 +1180,7 @@ TypeAliasTemplateDecl::Create(ASTContext &C, DeclContext *DC, SourceLocation L,
 }
 
 TypeAliasTemplateDecl *TypeAliasTemplateDecl::CreateDeserialized(ASTContext &C,
-                                                                 unsigned ID) {
+                                                                 Decl::DeclID ID) {
   return new (C, ID) TypeAliasTemplateDecl(C, nullptr, SourceLocation(),
                                            DeclarationName(), nullptr, nullptr);
 }
@@ -1218,7 +1218,7 @@ VarTemplateDecl *VarTemplateDecl::Create(ASTContext &C, DeclContext *DC,
 }
 
 VarTemplateDecl *VarTemplateDecl::CreateDeserialized(ASTContext &C,
-                                                     unsigned ID) {
+                                                     Decl::DeclID ID) {
   return new (C, ID) VarTemplateDecl(C, nullptr, SourceLocation(),
                                      DeclarationName(), nullptr, nullptr);
 }
@@ -1340,7 +1340,7 @@ VarTemplateSpecializationDecl *VarTemplateSpecializationDecl::Create(
 }
 
 VarTemplateSpecializationDecl *
-VarTemplateSpecializationDecl::CreateDeserialized(ASTContext &C, unsigned ID) {
+VarTemplateSpecializationDecl::CreateDeserialized(ASTContext &C, Decl::DeclID ID) {
   return new (C, ID)
       VarTemplateSpecializationDecl(VarTemplateSpecialization, C);
 }
@@ -1432,7 +1432,7 @@ VarTemplatePartialSpecializationDecl::Create(
 
 VarTemplatePartialSpecializationDecl *
 VarTemplatePartialSpecializationDecl::CreateDeserialized(ASTContext &C,
-                                                         unsigned ID) {
+                                                         Decl::DeclID ID) {
   return new (C, ID) VarTemplatePartialSpecializationDecl(C);
 }
 
@@ -1546,7 +1546,7 @@ TemplateParamObjectDecl *TemplateParamObjectDecl::Create(const ASTContext &C,
 }
 
 TemplateParamObjectDecl *
-TemplateParamObjectDecl::CreateDeserialized(ASTContext &C, unsigned ID) {
+TemplateParamObjectDecl::CreateDeserialized(ASTContext &C, Decl::DeclID ID) {
   auto *TPOD = new (C, ID) TemplateParamObjectDecl(nullptr, QualType(), APValue());
   C.addDestruction(&TPOD->Value);
   return TPOD;