[NFC] [Serialization] Avoid using DeclID directly as much as possible

This patch tries to remove all the direct use of DeclID except the real low level reading and writing. All the use of DeclID is converted to the use of LocalDeclID or GlobalDeclID. This is helpful to increase the readability and type safety.
author: Chuanqi Xu <yedeng.yd@linux.alibaba.com> 2024-04-25 11:43:13 +0800
committer: Chuanqi Xu <yedeng.yd@linux.alibaba.com> 2024-04-25 14:14:05 +0800
commit: 42070a5c092ed420bf92ebf38229c594885e94c7 (patch)
tree: 843afa1cc0c179d42d2dc0ed8a2dada5964a6734 /clang/lib
parent: c2a98fdeb3aede1a8db492a6ea30f4fa85b60edc (diff)
download: llvm-42070a5c092ed420bf92ebf38229c594885e94c7.zip
llvm-42070a5c092ed420bf92ebf38229c594885e94c7.tar.gz
llvm-42070a5c092ed420bf92ebf38229c594885e94c7.tar.bz2
17 files changed, 299 insertions, 282 deletions
diff --git a/clang/lib/AST/ASTContext.cpp b/clang/lib/AST/ASTContext.cpp
index a7386f755..475b47a 100644
--- a/clang/lib/AST/ASTContext.cpp
+++ b/clang/lib/AST/ASTContext.cpp
@@ -1083,7 +1083,8 @@ void ASTContext::addModuleInitializer(Module *M, Decl *D) {
   Inits->Initializers.push_back(D);
 }
 
-void ASTContext::addLazyModuleInitializers(Module *M, ArrayRef<DeclID> IDs) {
+void ASTContext::addLazyModuleInitializers(Module *M,
+                                           ArrayRef<GlobalDeclID> IDs) {
   auto *&Inits = ModuleInitializers[M];
   if (!Inits)
     Inits = new (*this) PerModuleInitializers;
diff --git a/clang/lib/AST/Decl.cpp b/clang/lib/AST/Decl.cpp
index f452902..e7e95c1 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, DeclID ID) {
+VarDecl *VarDecl::CreateDeserialized(ASTContext &C, GlobalDeclID 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, DeclID ID) {
+ParmVarDecl *ParmVarDecl::CreateDeserialized(ASTContext &C, GlobalDeclID 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, DeclID ID) {
+FieldDecl *FieldDecl::CreateDeserialized(ASTContext &C, GlobalDeclID 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, DeclID ID) {
+EnumDecl *EnumDecl::CreateDeserialized(ASTContext &C, GlobalDeclID ID) {
   EnumDecl *Enum =
       new (C, ID) EnumDecl(C, nullptr, SourceLocation(), SourceLocation(),
                            nullptr, nullptr, false, false, false);
@@ -5025,7 +5025,8 @@ RecordDecl *RecordDecl::Create(const ASTContext &C, TagKind TK, DeclContext *DC,
   return R;
 }
 
-RecordDecl *RecordDecl::CreateDeserialized(const ASTContext &C, DeclID ID) {
+RecordDecl *RecordDecl::CreateDeserialized(const ASTContext &C,
+                                           GlobalDeclID ID) {
   RecordDecl *R = new (C, ID)
       RecordDecl(Record, TagTypeKind::Struct, C, nullptr, SourceLocation(),
                  SourceLocation(), nullptr, nullptr);
@@ -5297,7 +5298,7 @@ PragmaCommentDecl *PragmaCommentDecl::Create(const ASTContext &C,
 }
 
 PragmaCommentDecl *PragmaCommentDecl::CreateDeserialized(ASTContext &C,
-                                                         DeclID ID,
+                                                         GlobalDeclID ID,
                                                          unsigned ArgSize) {
   return new (C, ID, additionalSizeToAlloc<char>(ArgSize + 1))
       PragmaCommentDecl(nullptr, SourceLocation(), PCK_Unknown);
@@ -5322,7 +5323,7 @@ PragmaDetectMismatchDecl::Create(const ASTContext &C, TranslationUnitDecl *DC,
 }
 
 PragmaDetectMismatchDecl *
-PragmaDetectMismatchDecl::CreateDeserialized(ASTContext &C, DeclID ID,
+PragmaDetectMismatchDecl::CreateDeserialized(ASTContext &C, GlobalDeclID ID,
                                              unsigned NameValueSize) {
   return new (C, ID, additionalSizeToAlloc<char>(NameValueSize + 1))
       PragmaDetectMismatchDecl(nullptr, SourceLocation(), 0);
@@ -5349,7 +5350,7 @@ LabelDecl *LabelDecl::Create(ASTContext &C, DeclContext *DC,
   return new (C, DC) LabelDecl(DC, IdentL, II, nullptr, GnuLabelL);
 }
 
-LabelDecl *LabelDecl::CreateDeserialized(ASTContext &C, DeclID ID) {
+LabelDecl *LabelDecl::CreateDeserialized(ASTContext &C, GlobalDeclID ID) {
   return new (C, ID) LabelDecl(nullptr, SourceLocation(), nullptr, nullptr,
                                SourceLocation());
 }
@@ -5390,7 +5391,7 @@ ImplicitParamDecl *ImplicitParamDecl::Create(ASTContext &C, QualType Type,
 }
 
 ImplicitParamDecl *ImplicitParamDecl::CreateDeserialized(ASTContext &C,
-                                                         DeclID ID) {
+                                                         GlobalDeclID ID) {
   return new (C, ID) ImplicitParamDecl(C, QualType(), ImplicitParamKind::Other);
 }
 
@@ -5408,7 +5409,7 @@ FunctionDecl::Create(ASTContext &C, DeclContext *DC, SourceLocation StartLoc,
   return New;
 }
 
-FunctionDecl *FunctionDecl::CreateDeserialized(ASTContext &C, DeclID ID) {
+FunctionDecl *FunctionDecl::CreateDeserialized(ASTContext &C, GlobalDeclID ID) {
   return new (C, ID) FunctionDecl(
       Function, C, nullptr, SourceLocation(), DeclarationNameInfo(), QualType(),
       nullptr, SC_None, false, false, ConstexprSpecKind::Unspecified, nullptr);
@@ -5418,7 +5419,7 @@ BlockDecl *BlockDecl::Create(ASTContext &C, DeclContext *DC, SourceLocation L) {
   return new (C, DC) BlockDecl(DC, L);
 }
 
-BlockDecl *BlockDecl::CreateDeserialized(ASTContext &C, DeclID ID) {
+BlockDecl *BlockDecl::CreateDeserialized(ASTContext &C, GlobalDeclID ID) {
   return new (C, ID) BlockDecl(nullptr, SourceLocation());
 }
 
@@ -5432,7 +5433,7 @@ CapturedDecl *CapturedDecl::Create(ASTContext &C, DeclContext *DC,
       CapturedDecl(DC, NumParams);
 }
 
-CapturedDecl *CapturedDecl::CreateDeserialized(ASTContext &C, DeclID ID,
+CapturedDecl *CapturedDecl::CreateDeserialized(ASTContext &C, GlobalDeclID ID,
                                                unsigned NumParams) {
   return new (C, ID, additionalSizeToAlloc<ImplicitParamDecl *>(NumParams))
       CapturedDecl(nullptr, NumParams);
@@ -5459,7 +5460,7 @@ EnumConstantDecl *EnumConstantDecl::Create(ASTContext &C, EnumDecl *CD,
 }
 
 EnumConstantDecl *EnumConstantDecl::CreateDeserialized(ASTContext &C,
-                                                       DeclID ID) {
+                                                       GlobalDeclID ID) {
   return new (C, ID) EnumConstantDecl(C, nullptr, SourceLocation(), nullptr,
                                       QualType(), nullptr, llvm::APSInt());
 }
@@ -5486,7 +5487,7 @@ IndirectFieldDecl::Create(ASTContext &C, DeclContext *DC, SourceLocation L,
 }
 
 IndirectFieldDecl *IndirectFieldDecl::CreateDeserialized(ASTContext &C,
-                                                         DeclID ID) {
+                                                         GlobalDeclID ID) {
   return new (C, ID)
       IndirectFieldDecl(C, nullptr, SourceLocation(), DeclarationName(),
                         QualType(), std::nullopt);
@@ -5547,7 +5548,7 @@ bool TypedefNameDecl::isTransparentTagSlow() const {
   return isTransparent;
 }
 
-TypedefDecl *TypedefDecl::CreateDeserialized(ASTContext &C, DeclID ID) {
+TypedefDecl *TypedefDecl::CreateDeserialized(ASTContext &C, GlobalDeclID ID) {
   return new (C, ID) TypedefDecl(C, nullptr, SourceLocation(), SourceLocation(),
                                  nullptr, nullptr);
 }
@@ -5560,7 +5561,8 @@ TypeAliasDecl *TypeAliasDecl::Create(ASTContext &C, DeclContext *DC,
   return new (C, DC) TypeAliasDecl(C, DC, StartLoc, IdLoc, Id, TInfo);
 }
 
-TypeAliasDecl *TypeAliasDecl::CreateDeserialized(ASTContext &C, DeclID ID) {
+TypeAliasDecl *TypeAliasDecl::CreateDeserialized(ASTContext &C,
+                                                 GlobalDeclID ID) {
   return new (C, ID) TypeAliasDecl(C, nullptr, SourceLocation(),
                                    SourceLocation(), nullptr, nullptr);
 }
@@ -5591,7 +5593,7 @@ FileScopeAsmDecl *FileScopeAsmDecl::Create(ASTContext &C, DeclContext *DC,
 }
 
 FileScopeAsmDecl *FileScopeAsmDecl::CreateDeserialized(ASTContext &C,
-                                                       DeclID ID) {
+                                                       GlobalDeclID ID) {
   return new (C, ID) FileScopeAsmDecl(nullptr, nullptr, SourceLocation(),
                                       SourceLocation());
 }
@@ -5609,7 +5611,7 @@ TopLevelStmtDecl *TopLevelStmtDecl::Create(ASTContext &C, Stmt *Statement) {
 }
 
 TopLevelStmtDecl *TopLevelStmtDecl::CreateDeserialized(ASTContext &C,
-                                                       DeclID ID) {
+                                                       GlobalDeclID ID) {
   return new (C, ID)
       TopLevelStmtDecl(/*DC=*/nullptr, SourceLocation(), /*S=*/nullptr);
 }
@@ -5630,7 +5632,7 @@ EmptyDecl *EmptyDecl::Create(ASTContext &C, DeclContext *DC, SourceLocation L) {
   return new (C, DC) EmptyDecl(DC, L);
 }
 
-EmptyDecl *EmptyDecl::CreateDeserialized(ASTContext &C, DeclID ID) {
+EmptyDecl *EmptyDecl::CreateDeserialized(ASTContext &C, GlobalDeclID ID) {
   return new (C, ID) EmptyDecl(nullptr, SourceLocation());
 }
 
@@ -5663,7 +5665,8 @@ HLSLBufferDecl *HLSLBufferDecl::Create(ASTContext &C,
   return Result;
 }
 
-HLSLBufferDecl *HLSLBufferDecl::CreateDeserialized(ASTContext &C, DeclID ID) {
+HLSLBufferDecl *HLSLBufferDecl::CreateDeserialized(ASTContext &C,
+                                                   GlobalDeclID ID) {
   return new (C, ID) HLSLBufferDecl(nullptr, false, SourceLocation(), nullptr,
                                     SourceLocation(), SourceLocation());
 }
@@ -5719,7 +5722,7 @@ ImportDecl *ImportDecl::CreateImplicit(ASTContext &C, DeclContext *DC,
   return Import;
 }
 
-ImportDecl *ImportDecl::CreateDeserialized(ASTContext &C, DeclID ID,
+ImportDecl *ImportDecl::CreateDeserialized(ASTContext &C, GlobalDeclID ID,
                                            unsigned NumLocations) {
   return new (C, ID, additionalSizeToAlloc<SourceLocation>(NumLocations))
       ImportDecl(EmptyShell());
@@ -5752,6 +5755,6 @@ ExportDecl *ExportDecl::Create(ASTContext &C, DeclContext *DC,
   return new (C, DC) ExportDecl(DC, ExportLoc);
 }
 
-ExportDecl *ExportDecl::CreateDeserialized(ASTContext &C, DeclID ID) {
+ExportDecl *ExportDecl::CreateDeserialized(ASTContext &C, GlobalDeclID ID) {
   return new (C, ID) ExportDecl(nullptr, SourceLocation());
 }
diff --git a/clang/lib/AST/DeclBase.cpp b/clang/lib/AST/DeclBase.cpp
index a2d88cf..c33babf 100644
--- a/clang/lib/AST/DeclBase.cpp
+++ b/clang/lib/AST/DeclBase.cpp
@@ -70,8 +70,8 @@ void Decl::updateOutOfDate(IdentifierInfo &II) const {
 #define ABSTRACT_DECL(DECL)
 #include "clang/AST/DeclNodes.inc"
 
-void *Decl::operator new(std::size_t Size, const ASTContext &Context, DeclID ID,
-                         std::size_t Extra) {
+void *Decl::operator new(std::size_t Size, const ASTContext &Context,
+                         GlobalDeclID 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),
@@ -85,7 +85,7 @@ void *Decl::operator new(std::size_t Size, const ASTContext &Context, DeclID ID,
   PrefixPtr[0] = 0;
 
   // Store the global declaration ID in the second 4 bytes.
-  PrefixPtr[1] = ID;
+  PrefixPtr[1] = ID.get();
 
   return Result;
 }
diff --git a/clang/lib/AST/DeclCXX.cpp b/clang/lib/AST/DeclCXX.cpp
index c525c33..75c4412 100644
--- a/clang/lib/AST/DeclCXX.cpp
+++ b/clang/lib/AST/DeclCXX.cpp
@@ -57,7 +57,8 @@ using namespace clang;
 
 void AccessSpecDecl::anchor() {}
 
-AccessSpecDecl *AccessSpecDecl::CreateDeserialized(ASTContext &C, DeclID ID) {
+AccessSpecDecl *AccessSpecDecl::CreateDeserialized(ASTContext &C,
+                                                   GlobalDeclID ID) {
   return new (C, ID) AccessSpecDecl(EmptyShell());
 }
 
@@ -68,7 +69,7 @@ void LazyASTUnresolvedSet::getFromExternalSource(ASTContext &C) const {
 
   for (ASTUnresolvedSet::iterator I = Impl.begin(); I != Impl.end(); ++I)
     I.setDecl(cast<NamedDecl>(Source->GetExternalDecl(
-        reinterpret_cast<uintptr_t>(I.getDecl()) >> 2)));
+        GlobalDeclID(reinterpret_cast<uintptr_t>(I.getDecl()) >> 2))));
   Impl.Decls.setLazy(false);
 }
 
@@ -161,7 +162,7 @@ CXXRecordDecl::CreateLambda(const ASTContext &C, DeclContext *DC,
 }
 
 CXXRecordDecl *CXXRecordDecl::CreateDeserialized(const ASTContext &C,
-                                                 DeclID ID) {
+                                                 GlobalDeclID ID) {
   auto *R = new (C, ID)
       CXXRecordDecl(CXXRecord, TagTypeKind::Struct, C, nullptr,
                     SourceLocation(), SourceLocation(), nullptr, nullptr);
@@ -2162,8 +2163,8 @@ CXXDeductionGuideDecl *CXXDeductionGuideDecl::Create(
                                            TInfo, EndLocation, Ctor, Kind);
 }
 
-CXXDeductionGuideDecl *CXXDeductionGuideDecl::CreateDeserialized(ASTContext &C,
-                                                                 DeclID ID) {
+CXXDeductionGuideDecl *
+CXXDeductionGuideDecl::CreateDeserialized(ASTContext &C, GlobalDeclID ID) {
   return new (C, ID) CXXDeductionGuideDecl(
       C, nullptr, SourceLocation(), ExplicitSpecifier(), DeclarationNameInfo(),
       QualType(), nullptr, SourceLocation(), nullptr,
@@ -2175,8 +2176,8 @@ RequiresExprBodyDecl *RequiresExprBodyDecl::Create(
   return new (C, DC) RequiresExprBodyDecl(C, DC, StartLoc);
 }
 
-RequiresExprBodyDecl *RequiresExprBodyDecl::CreateDeserialized(ASTContext &C,
-                                                               DeclID ID) {
+RequiresExprBodyDecl *
+RequiresExprBodyDecl::CreateDeserialized(ASTContext &C, GlobalDeclID ID) {
   return new (C, ID) RequiresExprBodyDecl(C, nullptr, SourceLocation());
 }
 
@@ -2281,7 +2282,8 @@ CXXMethodDecl::Create(ASTContext &C, CXXRecordDecl *RD, SourceLocation StartLoc,
       isInline, ConstexprKind, EndLocation, TrailingRequiresClause);
 }
 
-CXXMethodDecl *CXXMethodDecl::CreateDeserialized(ASTContext &C, DeclID ID) {
+CXXMethodDecl *CXXMethodDecl::CreateDeserialized(ASTContext &C,
+                                                 GlobalDeclID ID) {
   return new (C, ID) CXXMethodDecl(
       CXXMethod, C, nullptr, SourceLocation(), DeclarationNameInfo(),
       QualType(), nullptr, SC_None, false, false,
@@ -2699,7 +2701,7 @@ CXXConstructorDecl::CXXConstructorDecl(
 void CXXConstructorDecl::anchor() {}
 
 CXXConstructorDecl *CXXConstructorDecl::CreateDeserialized(ASTContext &C,
-                                                           DeclID ID,
+                                                           GlobalDeclID ID,
                                                            uint64_t AllocKind) {
   bool hasTrailingExplicit = static_cast<bool>(AllocKind & TAKHasTailExplicit);
   bool isInheritingConstructor =
@@ -2846,7 +2848,7 @@ bool CXXConstructorDecl::isSpecializationCopyingObject() const {
 void CXXDestructorDecl::anchor() {}
 
 CXXDestructorDecl *CXXDestructorDecl::CreateDeserialized(ASTContext &C,
-                                                         DeclID ID) {
+                                                         GlobalDeclID ID) {
   return new (C, ID) CXXDestructorDecl(
       C, nullptr, SourceLocation(), DeclarationNameInfo(), QualType(), nullptr,
       false, false, false, ConstexprSpecKind::Unspecified, nullptr);
@@ -2878,7 +2880,7 @@ void CXXDestructorDecl::setOperatorDelete(FunctionDecl *OD, Expr *ThisArg) {
 void CXXConversionDecl::anchor() {}
 
 CXXConversionDecl *CXXConversionDecl::CreateDeserialized(ASTContext &C,
-                                                         DeclID ID) {
+                                                         GlobalDeclID ID) {
   return new (C, ID) CXXConversionDecl(
       C, nullptr, SourceLocation(), DeclarationNameInfo(), QualType(), nullptr,
       false, false, ExplicitSpecifier(), ConstexprSpecKind::Unspecified,
@@ -2923,7 +2925,8 @@ LinkageSpecDecl *LinkageSpecDecl::Create(ASTContext &C, DeclContext *DC,
   return new (C, DC) LinkageSpecDecl(DC, ExternLoc, LangLoc, Lang, HasBraces);
 }
 
-LinkageSpecDecl *LinkageSpecDecl::CreateDeserialized(ASTContext &C, DeclID ID) {
+LinkageSpecDecl *LinkageSpecDecl::CreateDeserialized(ASTContext &C,
+                                                     GlobalDeclID ID) {
   return new (C, ID)
       LinkageSpecDecl(nullptr, SourceLocation(), SourceLocation(),
                       LinkageSpecLanguageIDs::C, false);
@@ -2945,7 +2948,7 @@ UsingDirectiveDecl *UsingDirectiveDecl::Create(ASTContext &C, DeclContext *DC,
 }
 
 UsingDirectiveDecl *UsingDirectiveDecl::CreateDeserialized(ASTContext &C,
-                                                           DeclID ID) {
+                                                           GlobalDeclID ID) {
   return new (C, ID) UsingDirectiveDecl(nullptr, SourceLocation(),
                                         SourceLocation(),
                                         NestedNameSpecifierLoc(),
@@ -2984,7 +2987,8 @@ NamespaceDecl *NamespaceDecl::Create(ASTContext &C, DeclContext *DC,
       NamespaceDecl(C, DC, Inline, StartLoc, IdLoc, Id, PrevDecl, Nested);
 }
 
-NamespaceDecl *NamespaceDecl::CreateDeserialized(ASTContext &C, DeclID ID) {
+NamespaceDecl *NamespaceDecl::CreateDeserialized(ASTContext &C,
+                                                 GlobalDeclID ID) {
   return new (C, ID) NamespaceDecl(C, nullptr, false, SourceLocation(),
                                    SourceLocation(), nullptr, nullptr, false);
 }
@@ -3046,7 +3050,7 @@ NamespaceAliasDecl *NamespaceAliasDecl::Create(ASTContext &C, DeclContext *DC,
 }
 
 NamespaceAliasDecl *NamespaceAliasDecl::CreateDeserialized(ASTContext &C,
-                                                           DeclID ID) {
+                                                           GlobalDeclID ID) {
   return new (C, ID) NamespaceAliasDecl(C, nullptr, SourceLocation(),
                                         SourceLocation(), nullptr,
                                         NestedNameSpecifierLoc(),
@@ -3101,7 +3105,8 @@ UsingShadowDecl::UsingShadowDecl(Kind K, ASTContext &C, EmptyShell Empty)
     : NamedDecl(K, nullptr, SourceLocation(), DeclarationName()),
       redeclarable_base(C) {}
 
-UsingShadowDecl *UsingShadowDecl::CreateDeserialized(ASTContext &C, DeclID ID) {
+UsingShadowDecl *UsingShadowDecl::CreateDeserialized(ASTContext &C,
+                                                     GlobalDeclID ID) {
   return new (C, ID) UsingShadowDecl(UsingShadow, C, EmptyShell());
 }
 
@@ -3124,7 +3129,7 @@ ConstructorUsingShadowDecl::Create(ASTContext &C, DeclContext *DC,
 }
 
 ConstructorUsingShadowDecl *
-ConstructorUsingShadowDecl::CreateDeserialized(ASTContext &C, DeclID ID) {
+ConstructorUsingShadowDecl::CreateDeserialized(ASTContext &C, GlobalDeclID ID) {
   return new (C, ID) ConstructorUsingShadowDecl(C, EmptyShell());
 }
 
@@ -3172,7 +3177,7 @@ UsingDecl *UsingDecl::Create(ASTContext &C, DeclContext *DC, SourceLocation UL,
   return new (C, DC) UsingDecl(DC, UL, QualifierLoc, NameInfo, HasTypename);
 }
 
-UsingDecl *UsingDecl::CreateDeserialized(ASTContext &C, DeclID ID) {
+UsingDecl *UsingDecl::CreateDeserialized(ASTContext &C, GlobalDeclID ID) {
   return new (C, ID) UsingDecl(nullptr, SourceLocation(),
                                NestedNameSpecifierLoc(), DeclarationNameInfo(),
                                false);
@@ -3196,7 +3201,8 @@ UsingEnumDecl *UsingEnumDecl::Create(ASTContext &C, DeclContext *DC,
       UsingEnumDecl(DC, EnumType->getType()->getAsTagDecl()->getDeclName(), UL, EL, NL, EnumType);
 }
 
-UsingEnumDecl *UsingEnumDecl::CreateDeserialized(ASTContext &C, DeclID ID) {
+UsingEnumDecl *UsingEnumDecl::CreateDeserialized(ASTContext &C,
+                                                 GlobalDeclID ID) {
   return new (C, ID)
       UsingEnumDecl(nullptr, DeclarationName(), SourceLocation(),
                     SourceLocation(), SourceLocation(), nullptr);
@@ -3215,7 +3221,7 @@ UsingPackDecl *UsingPackDecl::Create(ASTContext &C, DeclContext *DC,
   return new (C, DC, Extra) UsingPackDecl(DC, InstantiatedFrom, UsingDecls);
 }
 
-UsingPackDecl *UsingPackDecl::CreateDeserialized(ASTContext &C, DeclID ID,
+UsingPackDecl *UsingPackDecl::CreateDeserialized(ASTContext &C, GlobalDeclID ID,
                                                  unsigned NumExpansions) {
   size_t Extra = additionalSizeToAlloc<NamedDecl *>(NumExpansions);
   auto *Result =
@@ -3241,7 +3247,7 @@ UnresolvedUsingValueDecl::Create(ASTContext &C, DeclContext *DC,
 }
 
 UnresolvedUsingValueDecl *
-UnresolvedUsingValueDecl::CreateDeserialized(ASTContext &C, DeclID ID) {
+UnresolvedUsingValueDecl::CreateDeserialized(ASTContext &C, GlobalDeclID ID) {
   return new (C, ID) UnresolvedUsingValueDecl(nullptr, QualType(),
                                               SourceLocation(),
                                               NestedNameSpecifierLoc(),
@@ -3271,7 +3277,8 @@ UnresolvedUsingTypenameDecl::Create(ASTContext &C, DeclContext *DC,
 }
 
 UnresolvedUsingTypenameDecl *
-UnresolvedUsingTypenameDecl::CreateDeserialized(ASTContext &C, DeclID ID) {
+UnresolvedUsingTypenameDecl::CreateDeserialized(ASTContext &C,
+                                                GlobalDeclID ID) {
   return new (C, ID) UnresolvedUsingTypenameDecl(
       nullptr, SourceLocation(), SourceLocation(), NestedNameSpecifierLoc(),
       SourceLocation(), nullptr, SourceLocation());
@@ -3284,7 +3291,8 @@ UnresolvedUsingIfExistsDecl::Create(ASTContext &Ctx, DeclContext *DC,
 }
 
 UnresolvedUsingIfExistsDecl *
-UnresolvedUsingIfExistsDecl::CreateDeserialized(ASTContext &Ctx, DeclID ID) {
+UnresolvedUsingIfExistsDecl::CreateDeserialized(ASTContext &Ctx,
+                                                GlobalDeclID ID) {
   return new (Ctx, ID)
       UnresolvedUsingIfExistsDecl(nullptr, SourceLocation(), DeclarationName());
 }
@@ -3308,7 +3316,7 @@ StaticAssertDecl *StaticAssertDecl::Create(ASTContext &C, DeclContext *DC,
 }
 
 StaticAssertDecl *StaticAssertDecl::CreateDeserialized(ASTContext &C,
-                                                       DeclID ID) {
+                                                       GlobalDeclID ID) {
   return new (C, ID) StaticAssertDecl(nullptr, SourceLocation(), nullptr,
                                       nullptr, SourceLocation(), false);
 }
@@ -3330,7 +3338,7 @@ BindingDecl *BindingDecl::Create(ASTContext &C, DeclContext *DC,
   return new (C, DC) BindingDecl(DC, IdLoc, Id);
 }
 
-BindingDecl *BindingDecl::CreateDeserialized(ASTContext &C, DeclID ID) {
+BindingDecl *BindingDecl::CreateDeserialized(ASTContext &C, GlobalDeclID ID) {
   return new (C, ID) BindingDecl(nullptr, SourceLocation(), nullptr);
 }
 
@@ -3361,7 +3369,7 @@ DecompositionDecl *DecompositionDecl::Create(ASTContext &C, DeclContext *DC,
 }
 
 DecompositionDecl *DecompositionDecl::CreateDeserialized(ASTContext &C,
-                                                         DeclID ID,
+                                                         GlobalDeclID ID,
                                                          unsigned NumBindings) {
   size_t Extra = additionalSizeToAlloc<BindingDecl *>(NumBindings);
   auto *Result = new (C, ID, Extra)
@@ -3399,7 +3407,8 @@ MSPropertyDecl *MSPropertyDecl::Create(ASTContext &C, DeclContext *DC,
   return new (C, DC) MSPropertyDecl(DC, L, N, T, TInfo, StartL, Getter, Setter);
 }
 
-MSPropertyDecl *MSPropertyDecl::CreateDeserialized(ASTContext &C, DeclID ID) {
+MSPropertyDecl *MSPropertyDecl::CreateDeserialized(ASTContext &C,
+                                                   GlobalDeclID ID) {
   return new (C, ID) MSPropertyDecl(nullptr, SourceLocation(),
                                     DeclarationName(), QualType(), nullptr,
                                     SourceLocation(), nullptr, nullptr);
@@ -3416,7 +3425,7 @@ MSGuidDecl *MSGuidDecl::Create(const ASTContext &C, QualType T, Parts P) {
   return new (C, DC) MSGuidDecl(DC, T, P);
 }
 
-MSGuidDecl *MSGuidDecl::CreateDeserialized(ASTContext &C, DeclID ID) {
+MSGuidDecl *MSGuidDecl::CreateDeserialized(ASTContext &C, GlobalDeclID ID) {
   return new (C, ID) MSGuidDecl(nullptr, QualType(), Parts());
 }
 
@@ -3526,7 +3535,7 @@ UnnamedGlobalConstantDecl::Create(const ASTContext &C, QualType T,
 }
 
 UnnamedGlobalConstantDecl *
-UnnamedGlobalConstantDecl::CreateDeserialized(ASTContext &C, DeclID ID) {
+UnnamedGlobalConstantDecl::CreateDeserialized(ASTContext &C, GlobalDeclID 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 f6d11e5..04b9b93 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, DeclID ID,
+FriendDecl *FriendDecl::CreateDeserialized(ASTContext &C, GlobalDeclID 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 f98ec67..83062b0 100644
--- a/clang/lib/AST/DeclObjC.cpp
+++ b/clang/lib/AST/DeclObjC.cpp
@@ -862,7 +862,8 @@ ObjCMethodDecl *ObjCMethodDecl::Create(
       isImplicitlyDeclared, isDefined, impControl, HasRelatedResultType);
 }
 
-ObjCMethodDecl *ObjCMethodDecl::CreateDeserialized(ASTContext &C, DeclID ID) {
+ObjCMethodDecl *ObjCMethodDecl::CreateDeserialized(ASTContext &C,
+                                                   GlobalDeclID ID) {
   return new (C, ID) ObjCMethodDecl(SourceLocation(), SourceLocation(),
                                     Selector(), QualType(), nullptr, nullptr);
 }
@@ -1486,7 +1487,7 @@ ObjCTypeParamDecl *ObjCTypeParamDecl::Create(ASTContext &ctx, DeclContext *dc,
 }
 
 ObjCTypeParamDecl *ObjCTypeParamDecl::CreateDeserialized(ASTContext &ctx,
-                                                         DeclID ID) {
+                                                         GlobalDeclID ID) {
   return new (ctx, ID) ObjCTypeParamDecl(ctx, nullptr,
                                          ObjCTypeParamVariance::Invariant,
                                          SourceLocation(), 0, SourceLocation(),
@@ -1551,7 +1552,7 @@ ObjCInterfaceDecl *ObjCInterfaceDecl::Create(
 }
 
 ObjCInterfaceDecl *ObjCInterfaceDecl::CreateDeserialized(const ASTContext &C,
-                                                         DeclID ID) {
+                                                         GlobalDeclID ID) {
   auto *Result = new (C, ID)
       ObjCInterfaceDecl(C, nullptr, SourceLocation(), nullptr, nullptr,
                         SourceLocation(), nullptr, false);
@@ -1865,7 +1866,7 @@ ObjCIvarDecl *ObjCIvarDecl::Create(ASTContext &C, ObjCContainerDecl *DC,
                                   synthesized);
 }
 
-ObjCIvarDecl *ObjCIvarDecl::CreateDeserialized(ASTContext &C, DeclID ID) {
+ObjCIvarDecl *ObjCIvarDecl::CreateDeserialized(ASTContext &C, GlobalDeclID ID) {
   return new (C, ID) ObjCIvarDecl(nullptr, SourceLocation(), SourceLocation(),
                                   nullptr, QualType(), nullptr,
                                   ObjCIvarDecl::None, nullptr, false);
@@ -1914,7 +1915,7 @@ ObjCAtDefsFieldDecl
 }
 
 ObjCAtDefsFieldDecl *ObjCAtDefsFieldDecl::CreateDeserialized(ASTContext &C,
-                                                             DeclID ID) {
+                                                             GlobalDeclID ID) {
   return new (C, ID) ObjCAtDefsFieldDecl(nullptr, SourceLocation(),
                                          SourceLocation(), nullptr, QualType(),
                                          nullptr);
@@ -1949,7 +1950,7 @@ ObjCProtocolDecl *ObjCProtocolDecl::Create(ASTContext &C, DeclContext *DC,
 }
 
 ObjCProtocolDecl *ObjCProtocolDecl::CreateDeserialized(ASTContext &C,
-                                                       DeclID ID) {
+                                                       GlobalDeclID ID) {
   ObjCProtocolDecl *Result =
       new (C, ID) ObjCProtocolDecl(C, nullptr, nullptr, SourceLocation(),
                                    SourceLocation(), nullptr);
@@ -2148,7 +2149,7 @@ ObjCCategoryDecl *ObjCCategoryDecl::Create(
 }
 
 ObjCCategoryDecl *ObjCCategoryDecl::CreateDeserialized(ASTContext &C,
-                                                       DeclID ID) {
+                                                       GlobalDeclID ID) {
   return new (C, ID) ObjCCategoryDecl(nullptr, SourceLocation(),
                                       SourceLocation(), SourceLocation(),
                                       nullptr, nullptr, nullptr);
@@ -2188,8 +2189,8 @@ ObjCCategoryImplDecl *ObjCCategoryImplDecl::Create(
                                           atStartLoc, CategoryNameLoc);
 }
 
-ObjCCategoryImplDecl *ObjCCategoryImplDecl::CreateDeserialized(ASTContext &C,
-                                                               DeclID ID) {
+ObjCCategoryImplDecl *
+ObjCCategoryImplDecl::CreateDeserialized(ASTContext &C, GlobalDeclID ID) {
   return new (C, ID) ObjCCategoryImplDecl(nullptr, nullptr, nullptr,
                                           SourceLocation(), SourceLocation(),
                                           SourceLocation());
@@ -2296,7 +2297,7 @@ ObjCImplementationDecl::Create(ASTContext &C, DeclContext *DC,
 }
 
 ObjCImplementationDecl *
-ObjCImplementationDecl::CreateDeserialized(ASTContext &C, DeclID ID) {
+ObjCImplementationDecl::CreateDeserialized(ASTContext &C, GlobalDeclID ID) {
   return new (C, ID) ObjCImplementationDecl(nullptr, nullptr, nullptr,
                                             SourceLocation(), SourceLocation());
 }
@@ -2339,7 +2340,7 @@ ObjCCompatibleAliasDecl::Create(ASTContext &C, DeclContext *DC,
 }
 
 ObjCCompatibleAliasDecl *
-ObjCCompatibleAliasDecl::CreateDeserialized(ASTContext &C, DeclID ID) {
+ObjCCompatibleAliasDecl::CreateDeserialized(ASTContext &C, GlobalDeclID ID) {
   return new (C, ID) ObjCCompatibleAliasDecl(nullptr, SourceLocation(),
                                              nullptr, nullptr);
 }
@@ -2360,7 +2361,7 @@ ObjCPropertyDecl::Create(ASTContext &C, DeclContext *DC, SourceLocation L,
 }
 
 ObjCPropertyDecl *ObjCPropertyDecl::CreateDeserialized(ASTContext &C,
-                                                       DeclID ID) {
+                                                       GlobalDeclID ID) {
   return new (C, ID) ObjCPropertyDecl(nullptr, SourceLocation(), nullptr,
                                       SourceLocation(), SourceLocation(),
                                       QualType(), nullptr, None);
@@ -2392,8 +2393,8 @@ ObjCPropertyImplDecl *ObjCPropertyImplDecl::Create(ASTContext &C,
                                           ivarLoc);
 }
 
-ObjCPropertyImplDecl *ObjCPropertyImplDecl::CreateDeserialized(ASTContext &C,
-                                                               DeclID ID) {
+ObjCPropertyImplDecl *
+ObjCPropertyImplDecl::CreateDeserialized(ASTContext &C, GlobalDeclID 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 9f1d2bd..81ca48e 100644
--- a/clang/lib/AST/DeclOpenMP.cpp
+++ b/clang/lib/AST/DeclOpenMP.cpp
@@ -35,8 +35,9 @@ OMPThreadPrivateDecl *OMPThreadPrivateDecl::Create(ASTContext &C,
   return D;
 }
 
-OMPThreadPrivateDecl *
-OMPThreadPrivateDecl::CreateDeserialized(ASTContext &C, DeclID ID, unsigned N) {
+OMPThreadPrivateDecl *OMPThreadPrivateDecl::CreateDeserialized(ASTContext &C,
+                                                               GlobalDeclID ID,
+                                                               unsigned N) {
   return OMPDeclarativeDirective::createEmptyDirective<OMPThreadPrivateDecl>(
       C, ID, 0, N);
 }
@@ -62,7 +63,8 @@ OMPAllocateDecl *OMPAllocateDecl::Create(ASTContext &C, DeclContext *DC,
   return D;
 }
 
-OMPAllocateDecl *OMPAllocateDecl::CreateDeserialized(ASTContext &C, DeclID ID,
+OMPAllocateDecl *OMPAllocateDecl::CreateDeserialized(ASTContext &C,
+                                                     GlobalDeclID ID,
                                                      unsigned NVars,
                                                      unsigned NClauses) {
   return OMPDeclarativeDirective::createEmptyDirective<OMPAllocateDecl>(
@@ -88,7 +90,8 @@ OMPRequiresDecl *OMPRequiresDecl::Create(ASTContext &C, DeclContext *DC,
                                                                    L);
 }
 
-OMPRequiresDecl *OMPRequiresDecl::CreateDeserialized(ASTContext &C, DeclID ID,
+OMPRequiresDecl *OMPRequiresDecl::CreateDeserialized(ASTContext &C,
+                                                     GlobalDeclID ID,
                                                      unsigned N) {
   return OMPDeclarativeDirective::createEmptyDirective<OMPRequiresDecl>(
       C, ID, N, 0, SourceLocation());
@@ -116,7 +119,7 @@ OMPDeclareReductionDecl *OMPDeclareReductionDecl::Create(
 }
 
 OMPDeclareReductionDecl *
-OMPDeclareReductionDecl::CreateDeserialized(ASTContext &C, DeclID ID) {
+OMPDeclareReductionDecl::CreateDeserialized(ASTContext &C, GlobalDeclID ID) {
   return new (C, ID) OMPDeclareReductionDecl(
       OMPDeclareReduction, /*DC=*/nullptr, SourceLocation(), DeclarationName(),
       QualType(), /*PrevDeclInScope=*/nullptr);
@@ -146,8 +149,9 @@ OMPDeclareMapperDecl *OMPDeclareMapperDecl::Create(
       C, DC, Clauses, 1, L, Name, T, VarName, PrevDeclInScope);
 }
 
-OMPDeclareMapperDecl *
-OMPDeclareMapperDecl::CreateDeserialized(ASTContext &C, DeclID ID, unsigned N) {
+OMPDeclareMapperDecl *OMPDeclareMapperDecl::CreateDeserialized(ASTContext &C,
+                                                               GlobalDeclID ID,
+                                                               unsigned N) {
   return OMPDeclarativeDirective::createEmptyDirective<OMPDeclareMapperDecl>(
       C, ID, N, 1, SourceLocation(), DeclarationName(), QualType(),
       DeclarationName(), /*PrevDeclInScope=*/nullptr);
@@ -177,7 +181,7 @@ OMPCapturedExprDecl *OMPCapturedExprDecl::Create(ASTContext &C, DeclContext *DC,
 }
 
 OMPCapturedExprDecl *OMPCapturedExprDecl::CreateDeserialized(ASTContext &C,
-                                                             DeclID ID) {
+                                                             GlobalDeclID 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 ca998b5..d27a30e 100644
--- a/clang/lib/AST/DeclTemplate.cpp
+++ b/clang/lib/AST/DeclTemplate.cpp
@@ -337,9 +337,10 @@ void RedeclarableTemplateDecl::loadLazySpecializationsImpl() const {
   CommonBase *CommonBasePtr = getMostRecentDecl()->getCommonPtr();
   if (CommonBasePtr->LazySpecializations) {
     ASTContext &Context = getASTContext();
-    DeclID *Specs = CommonBasePtr->LazySpecializations;
+    GlobalDeclID *Specs = CommonBasePtr->LazySpecializations;
     CommonBasePtr->LazySpecializations = nullptr;
-    for (uint32_t I = 0, N = *Specs++; I != N; ++I)
+    unsigned SpecSize = (*Specs++).get();
+    for (unsigned I = 0; I != SpecSize; ++I)
       (void)Context.getExternalSource()->GetExternalDecl(Specs[I]);
   }
 }
@@ -417,8 +418,8 @@ FunctionTemplateDecl::Create(ASTContext &C, DeclContext *DC, SourceLocation L,
   return TD;
 }
 
-FunctionTemplateDecl *FunctionTemplateDecl::CreateDeserialized(ASTContext &C,
-                                                               DeclID ID) {
+FunctionTemplateDecl *
+FunctionTemplateDecl::CreateDeserialized(ASTContext &C, GlobalDeclID ID) {
   return new (C, ID) FunctionTemplateDecl(C, nullptr, SourceLocation(),
                                           DeclarationName(), nullptr, nullptr);
 }
@@ -503,7 +504,7 @@ ClassTemplateDecl *ClassTemplateDecl::Create(ASTContext &C, DeclContext *DC,
 }
 
 ClassTemplateDecl *ClassTemplateDecl::CreateDeserialized(ASTContext &C,
-                                                         DeclID ID) {
+                                                         GlobalDeclID ID) {
   return new (C, ID) ClassTemplateDecl(C, nullptr, SourceLocation(),
                                        DeclarationName(), nullptr, nullptr);
 }
@@ -652,14 +653,14 @@ TemplateTypeParmDecl *TemplateTypeParmDecl::Create(
 }
 
 TemplateTypeParmDecl *
-TemplateTypeParmDecl::CreateDeserialized(const ASTContext &C, DeclID ID) {
+TemplateTypeParmDecl::CreateDeserialized(const ASTContext &C, GlobalDeclID ID) {
   return new (C, ID)
       TemplateTypeParmDecl(nullptr, SourceLocation(), SourceLocation(), nullptr,
                            false, false, std::nullopt);
 }
 
 TemplateTypeParmDecl *
-TemplateTypeParmDecl::CreateDeserialized(const ASTContext &C, DeclID ID,
+TemplateTypeParmDecl::CreateDeserialized(const ASTContext &C, GlobalDeclID ID,
                                          bool HasTypeConstraint) {
   return new (C, ID,
               additionalSizeToAlloc<TypeConstraint>(HasTypeConstraint ? 1 : 0))
@@ -759,7 +760,7 @@ NonTypeTemplateParmDecl *NonTypeTemplateParmDecl::Create(
 }
 
 NonTypeTemplateParmDecl *
-NonTypeTemplateParmDecl::CreateDeserialized(ASTContext &C, DeclID ID,
+NonTypeTemplateParmDecl::CreateDeserialized(ASTContext &C, GlobalDeclID ID,
                                             bool HasTypeConstraint) {
   return new (C, ID, additionalSizeToAlloc<std::pair<QualType,
                                                      TypeSourceInfo *>,
@@ -770,7 +771,7 @@ NonTypeTemplateParmDecl::CreateDeserialized(ASTContext &C, DeclID ID,
 }
 
 NonTypeTemplateParmDecl *
-NonTypeTemplateParmDecl::CreateDeserialized(ASTContext &C, DeclID ID,
+NonTypeTemplateParmDecl::CreateDeserialized(ASTContext &C, GlobalDeclID ID,
                                             unsigned NumExpandedTypes,
                                             bool HasTypeConstraint) {
   auto *NTTP =
@@ -836,13 +837,13 @@ TemplateTemplateParmDecl::Create(const ASTContext &C, DeclContext *DC,
 }
 
 TemplateTemplateParmDecl *
-TemplateTemplateParmDecl::CreateDeserialized(ASTContext &C, DeclID ID) {
+TemplateTemplateParmDecl::CreateDeserialized(ASTContext &C, GlobalDeclID ID) {
   return new (C, ID) TemplateTemplateParmDecl(nullptr, SourceLocation(), 0, 0,
                                               false, nullptr, false, nullptr);
 }
 
 TemplateTemplateParmDecl *
-TemplateTemplateParmDecl::CreateDeserialized(ASTContext &C, DeclID ID,
+TemplateTemplateParmDecl::CreateDeserialized(ASTContext &C, GlobalDeclID ID,
                                              unsigned NumExpansions) {
   auto *TTP =
       new (C, ID, additionalSizeToAlloc<TemplateParameterList *>(NumExpansions))
@@ -948,7 +949,8 @@ ClassTemplateSpecializationDecl::Create(ASTContext &Context, TagKind TK,
 }
 
 ClassTemplateSpecializationDecl *
-ClassTemplateSpecializationDecl::CreateDeserialized(ASTContext &C, DeclID ID) {
+ClassTemplateSpecializationDecl::CreateDeserialized(ASTContext &C,
+                                                    GlobalDeclID ID) {
   auto *Result =
     new (C, ID) ClassTemplateSpecializationDecl(C, ClassTemplateSpecialization);
   Result->setMayHaveOutOfDateDef(false);
@@ -1034,7 +1036,7 @@ ConceptDecl *ConceptDecl::Create(ASTContext &C, DeclContext *DC,
   return TD;
 }
 
-ConceptDecl *ConceptDecl::CreateDeserialized(ASTContext &C, DeclID ID) {
+ConceptDecl *ConceptDecl::CreateDeserialized(ASTContext &C, GlobalDeclID ID) {
   ConceptDecl *Result = new (C, ID) ConceptDecl(nullptr, SourceLocation(),
                                                 DeclarationName(),
                                                 nullptr, nullptr);
@@ -1068,7 +1070,7 @@ ImplicitConceptSpecializationDecl *ImplicitConceptSpecializationDecl::Create(
 
 ImplicitConceptSpecializationDecl *
 ImplicitConceptSpecializationDecl::CreateDeserialized(
-    const ASTContext &C, DeclID ID, unsigned NumTemplateArgs) {
+    const ASTContext &C, GlobalDeclID ID, unsigned NumTemplateArgs) {
   return new (C, ID, additionalSizeToAlloc<TemplateArgument>(NumTemplateArgs))
       ImplicitConceptSpecializationDecl(EmptyShell{}, NumTemplateArgs);
 }
@@ -1131,7 +1133,7 @@ Create(ASTContext &Context, TagKind TK,DeclContext *DC,
 
 ClassTemplatePartialSpecializationDecl *
 ClassTemplatePartialSpecializationDecl::CreateDeserialized(ASTContext &C,
-                                                           DeclID ID) {
+                                                           GlobalDeclID ID) {
   auto *Result = new (C, ID) ClassTemplatePartialSpecializationDecl(C);
   Result->setMayHaveOutOfDateDef(false);
   return Result;
@@ -1158,7 +1160,7 @@ FriendTemplateDecl::Create(ASTContext &Context, DeclContext *DC,
 }
 
 FriendTemplateDecl *FriendTemplateDecl::CreateDeserialized(ASTContext &C,
-                                                           DeclID ID) {
+                                                           GlobalDeclID ID) {
   return new (C, ID) FriendTemplateDecl(EmptyShell());
 }
 
@@ -1177,8 +1179,8 @@ TypeAliasTemplateDecl::Create(ASTContext &C, DeclContext *DC, SourceLocation L,
   return TD;
 }
 
-TypeAliasTemplateDecl *TypeAliasTemplateDecl::CreateDeserialized(ASTContext &C,
-                                                                 DeclID ID) {
+TypeAliasTemplateDecl *
+TypeAliasTemplateDecl::CreateDeserialized(ASTContext &C, GlobalDeclID ID) {
   return new (C, ID) TypeAliasTemplateDecl(C, nullptr, SourceLocation(),
                                            DeclarationName(), nullptr, nullptr);
 }
@@ -1215,7 +1217,8 @@ VarTemplateDecl *VarTemplateDecl::Create(ASTContext &C, DeclContext *DC,
   return TD;
 }
 
-VarTemplateDecl *VarTemplateDecl::CreateDeserialized(ASTContext &C, DeclID ID) {
+VarTemplateDecl *VarTemplateDecl::CreateDeserialized(ASTContext &C,
+                                                     GlobalDeclID ID) {
   return new (C, ID) VarTemplateDecl(C, nullptr, SourceLocation(),
                                      DeclarationName(), nullptr, nullptr);
 }
@@ -1337,7 +1340,8 @@ VarTemplateSpecializationDecl *VarTemplateSpecializationDecl::Create(
 }
 
 VarTemplateSpecializationDecl *
-VarTemplateSpecializationDecl::CreateDeserialized(ASTContext &C, DeclID ID) {
+VarTemplateSpecializationDecl::CreateDeserialized(ASTContext &C,
+                                                  GlobalDeclID ID) {
   return new (C, ID)
       VarTemplateSpecializationDecl(VarTemplateSpecialization, C);
 }
@@ -1429,7 +1433,7 @@ VarTemplatePartialSpecializationDecl::Create(
 
 VarTemplatePartialSpecializationDecl *
 VarTemplatePartialSpecializationDecl::CreateDeserialized(ASTContext &C,
-                                                         DeclID ID) {
+                                                         GlobalDeclID ID) {
   return new (C, ID) VarTemplatePartialSpecializationDecl(C);
 }
 
@@ -1543,7 +1547,7 @@ TemplateParamObjectDecl *TemplateParamObjectDecl::Create(const ASTContext &C,
 }
 
 TemplateParamObjectDecl *
-TemplateParamObjectDecl::CreateDeserialized(ASTContext &C, DeclID ID) {
+TemplateParamObjectDecl::CreateDeserialized(ASTContext &C, GlobalDeclID ID) {
   auto *TPOD = new (C, ID) TemplateParamObjectDecl(nullptr, QualType(), APValue());
   C.addDestruction(&TPOD->Value);
   return TPOD;
diff --git a/clang/lib/AST/ExternalASTSource.cpp b/clang/lib/AST/ExternalASTSource.cpp
index 26ded22..e96a474 100644
--- a/clang/lib/AST/ExternalASTSource.cpp
+++ b/clang/lib/AST/ExternalASTSource.cpp
@@ -68,7 +68,7 @@ bool ExternalASTSource::layoutRecordType(
   return false;
 }
 
-Decl *ExternalASTSource::GetExternalDecl(DeclID ID) { return nullptr; }
+Decl *ExternalASTSource::GetExternalDecl(GlobalDeclID ID) { return nullptr; }
 
 Selector ExternalASTSource::GetExternalSelector(uint32_t ID) {
   return Selector();
diff --git a/clang/lib/Frontend/ASTUnit.cpp b/clang/lib/Frontend/ASTUnit.cpp
index 361331d..2f75313e 100644
--- a/clang/lib/Frontend/ASTUnit.cpp
+++ b/clang/lib/Frontend/ASTUnit.cpp
@@ -1067,7 +1067,7 @@ public:
 
   std::vector<Decl *> takeTopLevelDecls() { return std::move(TopLevelDecls); }
 
-  std::vector<DeclID> takeTopLevelDeclIDs() {
+  std::vector<LocalDeclID> takeTopLevelDeclIDs() {
     return std::move(TopLevelDeclIDs);
   }
 
@@ -1101,7 +1101,7 @@ public:
 private:
   unsigned Hash = 0;
   std::vector<Decl *> TopLevelDecls;
-  std::vector<DeclID> TopLevelDeclIDs;
+  std::vector<LocalDeclID> TopLevelDeclIDs;
   llvm::SmallVector<ASTUnit::StandaloneDiagnostic, 4> PreambleDiags;
 };
 
@@ -1471,7 +1471,9 @@ void ASTUnit::RealizeTopLevelDeclsFromPreamble() {
   for (const auto TopLevelDecl : TopLevelDeclsInPreamble) {
     // Resolve the declaration ID to an actual declaration, possibly
     // deserializing the declaration in the process.
-    if (Decl *D = Source.GetExternalDecl(TopLevelDecl))
+    //
+    // FIMXE: We shouldn't convert a LocalDeclID to GlobalDeclID directly.
+    if (Decl *D = Source.GetExternalDecl(GlobalDeclID(TopLevelDecl.get())))
       Resolved.push_back(D);
   }
   TopLevelDeclsInPreamble.clear();
diff --git a/clang/lib/Frontend/FrontendAction.cpp b/clang/lib/Frontend/FrontendAction.cpp
index 91ce16e..a2af738 100644
--- a/clang/lib/Frontend/FrontendAction.cpp
+++ b/clang/lib/Frontend/FrontendAction.cpp
@@ -80,7 +80,7 @@ public:
     if (Previous)
       Previous->TypeRead(Idx, T);
   }
-  void DeclRead(DeclID ID, const Decl *D) override {
+  void DeclRead(GlobalDeclID ID, const Decl *D) override {
     if (Previous)
       Previous->DeclRead(ID, D);
   }
@@ -102,7 +102,7 @@ public:
                                    bool DeletePrevious)
       : DelegatingDeserializationListener(Previous, DeletePrevious) {}
 
-  void DeclRead(DeclID ID, const Decl *D) override {
+  void DeclRead(GlobalDeclID ID, const Decl *D) override {
     llvm::outs() << "PCH DECL: " << D->getDeclKindName();
     if (const NamedDecl *ND = dyn_cast<NamedDecl>(D)) {
       llvm::outs() << " - ";
@@ -128,7 +128,7 @@ public:
       : DelegatingDeserializationListener(Previous, DeletePrevious), Ctx(Ctx),
         NamesToCheck(NamesToCheck) {}
 
-  void DeclRead(DeclID ID, const Decl *D) override {
+  void DeclRead(GlobalDeclID ID, const Decl *D) override {
     if (const NamedDecl *ND = dyn_cast<NamedDecl>(D))
       if (NamesToCheck.find(ND->getNameAsString()) != NamesToCheck.end()) {
         unsigned DiagID
diff --git a/clang/lib/Frontend/MultiplexConsumer.cpp b/clang/lib/Frontend/MultiplexConsumer.cpp
index 9e885c8..c74bfd8 100644
--- a/clang/lib/Frontend/MultiplexConsumer.cpp
+++ b/clang/lib/Frontend/MultiplexConsumer.cpp
@@ -52,7 +52,8 @@ void MultiplexASTDeserializationListener::TypeRead(
     Listeners[i]->TypeRead(Idx, T);
 }
 
-void MultiplexASTDeserializationListener::DeclRead(DeclID ID, const Decl *D) {
+void MultiplexASTDeserializationListener::DeclRead(GlobalDeclID ID,
+                                                   const Decl *D) {
   for (size_t i = 0, e = Listeners.size(); i != e; ++i)
     Listeners[i]->DeclRead(ID, D);
 }
diff --git a/clang/lib/Sema/MultiplexExternalSemaSource.cpp b/clang/lib/Sema/MultiplexExternalSemaSource.cpp
index e48c724..79e656e 100644
--- a/clang/lib/Sema/MultiplexExternalSemaSource.cpp
+++ b/clang/lib/Sema/MultiplexExternalSemaSource.cpp
@@ -46,7 +46,7 @@ void MultiplexExternalSemaSource::AddSource(ExternalSemaSource *Source) {
 // ExternalASTSource.
 //===----------------------------------------------------------------------===//
 
-Decl *MultiplexExternalSemaSource::GetExternalDecl(DeclID ID) {
+Decl *MultiplexExternalSemaSource::GetExternalDecl(GlobalDeclID ID) {
   for(size_t i = 0; i < Sources.size(); ++i)
     if (Decl *Result = Sources[i]->GetExternalDecl(ID))
       return Result;
diff --git a/clang/lib/Serialization/ASTReader.cpp b/clang/lib/Serialization/ASTReader.cpp
index df9984d..c99d6ed 100644
--- a/clang/lib/Serialization/ASTReader.cpp
+++ b/clang/lib/Serialization/ASTReader.cpp
@@ -5101,8 +5101,9 @@ void ASTReader::InitializeContext() {
 
   // If there's a listener, notify them that we "read" the translation unit.
   if (DeserializationListener)
-    DeserializationListener->DeclRead(PREDEF_DECL_TRANSLATION_UNIT_ID,
-                                      Context.getTranslationUnitDecl());
+    DeserializationListener->DeclRead(
+        GlobalDeclID(PREDEF_DECL_TRANSLATION_UNIT_ID),
+        Context.getTranslationUnitDecl());
 
   // FIXME: Find a better way to deal with collisions between these
   // built-in types. Right now, we just ignore the problem.
@@ -6010,9 +6011,9 @@ llvm::Error ASTReader::ReadSubmoduleBlock(ModuleFile &F,
     case SUBMODULE_INITIALIZERS: {
       if (!ContextObj)
         break;
-      SmallVector<DeclID, 16> Inits;
+      SmallVector<GlobalDeclID, 16> Inits;
       for (auto &ID : Record)
-        Inits.push_back(getGlobalDeclID(F, LocalDeclID(ID)).get());
+        Inits.push_back(getGlobalDeclID(F, LocalDeclID(ID)));
       ContextObj->addLazyModuleInitializers(CurrentModule, Inits);
       break;
     }
@@ -7517,9 +7518,7 @@ ASTRecordReader::readASTTemplateArgumentListInfo() {
   return ASTTemplateArgumentListInfo::Create(getContext(), Result);
 }
 
-Decl *ASTReader::GetExternalDecl(DeclID ID) {
-  return GetDecl(GlobalDeclID(ID));
-}
+Decl *ASTReader::GetExternalDecl(GlobalDeclID ID) { return GetDecl(ID); }
 
 void ASTReader::CompleteRedeclChain(const Decl *D) {
   if (NumCurrentElementsDeserializing) {
@@ -7767,7 +7766,7 @@ static Decl *getPredefinedDecl(ASTContext &Context, PredefinedDeclIDs ID) {
 Decl *ASTReader::GetExistingDecl(GlobalDeclID ID) {
   assert(ContextObj && "reading decl with no AST context");
   if (ID.get() < NUM_PREDEF_DECL_IDS) {
-    Decl *D = getPredefinedDecl(*ContextObj, (PredefinedDeclIDs)ID.get());
+    Decl *D = getPredefinedDecl(*ContextObj, (PredefinedDeclIDs)ID);
     if (D) {
       // Track that we have merged the declaration with ID \p ID into the
       // pre-existing predefined declaration \p D.
@@ -7804,17 +7803,17 @@ Decl *ASTReader::GetDecl(GlobalDeclID ID) {
   if (!DeclsLoaded[Index]) {
     ReadDeclRecord(ID);
     if (DeserializationListener)
-      DeserializationListener->DeclRead(ID.get(), DeclsLoaded[Index]);
+      DeserializationListener->DeclRead(ID, DeclsLoaded[Index]);
   }
 
   return DeclsLoaded[Index];
 }
 
-DeclID ASTReader::mapGlobalIDToModuleFileGlobalID(ModuleFile &M,
-                                                  GlobalDeclID GlobalID) {
+LocalDeclID ASTReader::mapGlobalIDToModuleFileGlobalID(ModuleFile &M,
+                                                       GlobalDeclID GlobalID) {
   DeclID ID = GlobalID.get();
   if (ID < NUM_PREDEF_DECL_IDS)
-    return ID;
+    return LocalDeclID(ID);
 
   GlobalDeclMapType::const_iterator I = GlobalDeclMap.find(GlobalID);
   assert(I != GlobalDeclMap.end() && "Corrupted global declaration map");
@@ -7823,9 +7822,9 @@ DeclID ASTReader::mapGlobalIDToModuleFileGlobalID(ModuleFile &M,
   llvm::DenseMap<ModuleFile *, DeclID>::iterator Pos =
       M.GlobalToLocalDeclIDs.find(Owner);
   if (Pos == M.GlobalToLocalDeclIDs.end())
-    return 0;
+    return LocalDeclID();
 
-  return ID - Owner->BaseDeclID + Pos->second;
+  return LocalDeclID(ID - Owner->BaseDeclID + Pos->second);
 }
 
 GlobalDeclID ASTReader::ReadDeclID(ModuleFile &F, const RecordData &Record,
@@ -7992,6 +7991,7 @@ ASTReader::FindExternalVisibleDeclsByName(const DeclContext *DC,
   // Load the list of declarations.
   SmallVector<NamedDecl *, 64> Decls;
   llvm::SmallPtrSet<NamedDecl *, 8> Found;
+
   for (GlobalDeclID ID : It->second.Table.find(Name)) {
     NamedDecl *ND = cast<NamedDecl>(GetDecl(ID));
     if (ND->getDeclName() == Name && Found.insert(ND).second)
diff --git a/clang/lib/Serialization/ASTReaderDecl.cpp b/clang/lib/Serialization/ASTReaderDecl.cpp
index 9707eed..744f11d 100644
--- a/clang/lib/Serialization/ASTReaderDecl.cpp
+++ b/clang/lib/Serialization/ASTReaderDecl.cpp
@@ -273,17 +273,15 @@ namespace clang {
       auto *&LazySpecializations = D->getCommonPtr()->LazySpecializations;
 
       if (auto &Old = LazySpecializations) {
-        IDs.insert(IDs.end(), GlobalDeclIDIterator(Old + 1),
-                   GlobalDeclIDIterator(Old + 1 + Old[0]));
+        IDs.insert(IDs.end(), Old + 1, Old + 1 + Old[0].get());
         llvm::sort(IDs);
         IDs.erase(std::unique(IDs.begin(), IDs.end()), IDs.end());
       }
 
-      auto *Result = new (C) DeclID[1 + IDs.size()];
-      *Result = IDs.size();
+      auto *Result = new (C) GlobalDeclID[1 + IDs.size()];
+      *Result = GlobalDeclID(IDs.size());
 
-      std::copy(DeclIDIterator(IDs.begin()), DeclIDIterator(IDs.end()),
-                Result + 1);
+      std::copy(IDs.begin(), IDs.end(), Result + 1);
 
       LazySpecializations = Result;
     }
@@ -558,7 +556,7 @@ void ASTDeclReader::Visit(Decl *D) {
 
     // If this is a tag declaration with a typedef name for linkage, it's safe
     // to load that typedef now.
-    if (NamedDeclForTagDecl != GlobalDeclID())
+    if (NamedDeclForTagDecl.isValid())
       cast<TagDecl>(D)->TypedefNameDeclOrQualifier =
           cast<TypedefNameDecl>(Reader.GetDecl(NamedDeclForTagDecl));
   } else if (auto *ID = dyn_cast<ObjCInterfaceDecl>(D)) {
@@ -603,7 +601,7 @@ void ASTDeclReader::VisitDecl(Decl *D) {
     GlobalDeclID SemaDCIDForTemplateParmDecl = readDeclID();
     GlobalDeclID LexicalDCIDForTemplateParmDecl =
         HasStandaloneLexicalDC ? readDeclID() : GlobalDeclID();
-    if (LexicalDCIDForTemplateParmDecl == GlobalDeclID())
+    if (LexicalDCIDForTemplateParmDecl.isInvalid())
       LexicalDCIDForTemplateParmDecl = SemaDCIDForTemplateParmDecl;
     Reader.addPendingDeclContextInfo(D,
                                      SemaDCIDForTemplateParmDecl,
@@ -1860,7 +1858,7 @@ void ASTDeclReader::VisitNamespaceDecl(NamespaceDecl *D) {
 
   mergeRedeclarable(D, Redecl);
 
-  if (AnonNamespace != GlobalDeclID()) {
+  if (AnonNamespace.isValid()) {
     // Each module has its own anonymous namespace, which is disjoint from
     // any other module's anonymous namespaces, so don't attach the anonymous
     // namespace at all.
@@ -2792,9 +2790,9 @@ ASTDeclReader::VisitRedeclarable(Redeclarable<T> *D) {
 
   uint64_t RedeclOffset = 0;
 
-  // 0 indicates that this declaration was the only declaration of its entity,
-  // and is used for space optimization.
-  if (FirstDeclID == GlobalDeclID()) {
+  // invalid FirstDeclID  indicates that this declaration was the only
+  // declaration of its entity, and is used for space optimization.
+  if (FirstDeclID.isInvalid()) {
     FirstDeclID = ThisDeclID;
     IsKeyDecl = true;
     IsFirstLocalDecl = true;
@@ -3829,240 +3827,232 @@ Decl *ASTReader::ReadDeclRecord(GlobalDeclID ID) {
         Twine("ASTReader::readDeclRecord failed reading decl code: ") +
         toString(MaybeDeclCode.takeError()));
 
-  DeclID RawGlobalID = ID.get();
   switch ((DeclCode)MaybeDeclCode.get()) {
   case DECL_CONTEXT_LEXICAL:
   case DECL_CONTEXT_VISIBLE:
     llvm_unreachable("Record cannot be de-serialized with readDeclRecord");
   case DECL_TYPEDEF:
-    D = TypedefDecl::CreateDeserialized(Context, RawGlobalID);
+    D = TypedefDecl::CreateDeserialized(Context, ID);
     break;
   case DECL_TYPEALIAS:
-    D = TypeAliasDecl::CreateDeserialized(Context, RawGlobalID);
+    D = TypeAliasDecl::CreateDeserialized(Context, ID);
     break;
   case DECL_ENUM:
-    D = EnumDecl::CreateDeserialized(Context, RawGlobalID);
+    D = EnumDecl::CreateDeserialized(Context, ID);
     break;
   case DECL_RECORD:
-    D = RecordDecl::CreateDeserialized(Context, RawGlobalID);
+    D = RecordDecl::CreateDeserialized(Context, ID);
     break;
   case DECL_ENUM_CONSTANT:
-    D = EnumConstantDecl::CreateDeserialized(Context, RawGlobalID);
+    D = EnumConstantDecl::CreateDeserialized(Context, ID);
     break;
   case DECL_FUNCTION:
-    D = FunctionDecl::CreateDeserialized(Context, RawGlobalID);
+    D = FunctionDecl::CreateDeserialized(Context, ID);
     break;
   case DECL_LINKAGE_SPEC:
-    D = LinkageSpecDecl::CreateDeserialized(Context, RawGlobalID);
+    D = LinkageSpecDecl::CreateDeserialized(Context, ID);
     break;
   case DECL_EXPORT:
-    D = ExportDecl::CreateDeserialized(Context, RawGlobalID);
+    D = ExportDecl::CreateDeserialized(Context, ID);
     break;
   case DECL_LABEL:
-    D = LabelDecl::CreateDeserialized(Context, RawGlobalID);
+    D = LabelDecl::CreateDeserialized(Context, ID);
     break;
   case DECL_NAMESPACE:
-    D = NamespaceDecl::CreateDeserialized(Context, RawGlobalID);
+    D = NamespaceDecl::CreateDeserialized(Context, ID);
     break;
   case DECL_NAMESPACE_ALIAS:
-    D = NamespaceAliasDecl::CreateDeserialized(Context, RawGlobalID);
+    D = NamespaceAliasDecl::CreateDeserialized(Context, ID);
     break;
   case DECL_USING:
-    D = UsingDecl::CreateDeserialized(Context, RawGlobalID);
+    D = UsingDecl::CreateDeserialized(Context, ID);
     break;
   case DECL_USING_PACK:
-    D = UsingPackDecl::CreateDeserialized(Context, RawGlobalID,
-                                          Record.readInt());
+    D = UsingPackDecl::CreateDeserialized(Context, ID, Record.readInt());
     break;
   case DECL_USING_SHADOW:
-    D = UsingShadowDecl::CreateDeserialized(Context, RawGlobalID);
+    D = UsingShadowDecl::CreateDeserialized(Context, ID);
     break;
   case DECL_USING_ENUM:
-    D = UsingEnumDecl::CreateDeserialized(Context, RawGlobalID);
+    D = UsingEnumDecl::CreateDeserialized(Context, ID);
     break;
   case DECL_CONSTRUCTOR_USING_SHADOW:
-    D = ConstructorUsingShadowDecl::CreateDeserialized(Context, RawGlobalID);
+    D = ConstructorUsingShadowDecl::CreateDeserialized(Context, ID);
     break;
   case DECL_USING_DIRECTIVE:
-    D = UsingDirectiveDecl::CreateDeserialized(Context, RawGlobalID);
+    D = UsingDirectiveDecl::CreateDeserialized(Context, ID);
     break;
   case DECL_UNRESOLVED_USING_VALUE:
-    D = UnresolvedUsingValueDecl::CreateDeserialized(Context, RawGlobalID);
+    D = UnresolvedUsingValueDecl::CreateDeserialized(Context, ID);
     break;
   case DECL_UNRESOLVED_USING_TYPENAME:
-    D = UnresolvedUsingTypenameDecl::CreateDeserialized(Context, RawGlobalID);
+    D = UnresolvedUsingTypenameDecl::CreateDeserialized(Context, ID);
     break;
   case DECL_UNRESOLVED_USING_IF_EXISTS:
-    D = UnresolvedUsingIfExistsDecl::CreateDeserialized(Context, RawGlobalID);
+    D = UnresolvedUsingIfExistsDecl::CreateDeserialized(Context, ID);
     break;
   case DECL_CXX_RECORD:
-    D = CXXRecordDecl::CreateDeserialized(Context, RawGlobalID);
+    D = CXXRecordDecl::CreateDeserialized(Context, ID);
     break;
   case DECL_CXX_DEDUCTION_GUIDE:
-    D = CXXDeductionGuideDecl::CreateDeserialized(Context, RawGlobalID);
+    D = CXXDeductionGuideDecl::CreateDeserialized(Context, ID);
     break;
   case DECL_CXX_METHOD:
-    D = CXXMethodDecl::CreateDeserialized(Context, RawGlobalID);
+    D = CXXMethodDecl::CreateDeserialized(Context, ID);
     break;
   case DECL_CXX_CONSTRUCTOR:
-    D = CXXConstructorDecl::CreateDeserialized(Context, RawGlobalID,
-                                               Record.readInt());
+    D = CXXConstructorDecl::CreateDeserialized(Context, ID, Record.readInt());
     break;
   case DECL_CXX_DESTRUCTOR:
-    D = CXXDestructorDecl::CreateDeserialized(Context, RawGlobalID);
+    D = CXXDestructorDecl::CreateDeserialized(Context, ID);
     break;
   case DECL_CXX_CONVERSION:
-    D = CXXConversionDecl::CreateDeserialized(Context, RawGlobalID);
+    D = CXXConversionDecl::CreateDeserialized(Context, ID);
     break;
   case DECL_ACCESS_SPEC:
-    D = AccessSpecDecl::CreateDeserialized(Context, RawGlobalID);
+    D = AccessSpecDecl::CreateDeserialized(Context, ID);
     break;
   case DECL_FRIEND:
-    D = FriendDecl::CreateDeserialized(Context, RawGlobalID, Record.readInt());
+    D = FriendDecl::CreateDeserialized(Context, ID, Record.readInt());
     break;
   case DECL_FRIEND_TEMPLATE:
-    D = FriendTemplateDecl::CreateDeserialized(Context, RawGlobalID);
+    D = FriendTemplateDecl::CreateDeserialized(Context, ID);
     break;
   case DECL_CLASS_TEMPLATE:
-    D = ClassTemplateDecl::CreateDeserialized(Context, RawGlobalID);
+    D = ClassTemplateDecl::CreateDeserialized(Context, ID);
     break;
   case DECL_CLASS_TEMPLATE_SPECIALIZATION:
-    D = ClassTemplateSpecializationDecl::CreateDeserialized(Context,
-                                                            RawGlobalID);
+    D = ClassTemplateSpecializationDecl::CreateDeserialized(Context, ID);
     break;
   case DECL_CLASS_TEMPLATE_PARTIAL_SPECIALIZATION:
-    D = ClassTemplatePartialSpecializationDecl::CreateDeserialized(Context,
-                                                                   RawGlobalID);
+    D = ClassTemplatePartialSpecializationDecl::CreateDeserialized(Context, ID);
     break;
   case DECL_VAR_TEMPLATE:
-    D = VarTemplateDecl::CreateDeserialized(Context, RawGlobalID);
+    D = VarTemplateDecl::CreateDeserialized(Context, ID);
     break;
   case DECL_VAR_TEMPLATE_SPECIALIZATION:
-    D = VarTemplateSpecializationDecl::CreateDeserialized(Context, RawGlobalID);
+    D = VarTemplateSpecializationDecl::CreateDeserialized(Context, ID);
     break;
   case DECL_VAR_TEMPLATE_PARTIAL_SPECIALIZATION:
-    D = VarTemplatePartialSpecializationDecl::CreateDeserialized(Context,
-                                                                 RawGlobalID);
+    D = VarTemplatePartialSpecializationDecl::CreateDeserialized(Context, ID);
     break;
   case DECL_FUNCTION_TEMPLATE:
-    D = FunctionTemplateDecl::CreateDeserialized(Context, RawGlobalID);
+    D = FunctionTemplateDecl::CreateDeserialized(Context, ID);
     break;
   case DECL_TEMPLATE_TYPE_PARM: {
     bool HasTypeConstraint = Record.readInt();
-    D = TemplateTypeParmDecl::CreateDeserialized(Context, RawGlobalID,
+    D = TemplateTypeParmDecl::CreateDeserialized(Context, ID,
                                                  HasTypeConstraint);
     break;
   }
   case DECL_NON_TYPE_TEMPLATE_PARM: {
     bool HasTypeConstraint = Record.readInt();
-    D = NonTypeTemplateParmDecl::CreateDeserialized(Context, RawGlobalID,
+    D = NonTypeTemplateParmDecl::CreateDeserialized(Context, ID,
                                                     HasTypeConstraint);
     break;
   }
   case DECL_EXPANDED_NON_TYPE_TEMPLATE_PARM_PACK: {
     bool HasTypeConstraint = Record.readInt();
     D = NonTypeTemplateParmDecl::CreateDeserialized(
-        Context, RawGlobalID, Record.readInt(), HasTypeConstraint);
+        Context, ID, Record.readInt(), HasTypeConstraint);
     break;
   }
   case DECL_TEMPLATE_TEMPLATE_PARM:
-    D = TemplateTemplateParmDecl::CreateDeserialized(Context, RawGlobalID);
+    D = TemplateTemplateParmDecl::CreateDeserialized(Context, ID);
     break;
   case DECL_EXPANDED_TEMPLATE_TEMPLATE_PARM_PACK:
-    D = TemplateTemplateParmDecl::CreateDeserialized(Context, RawGlobalID,
+    D = TemplateTemplateParmDecl::CreateDeserialized(Context, ID,
                                                      Record.readInt());
     break;
   case DECL_TYPE_ALIAS_TEMPLATE:
-    D = TypeAliasTemplateDecl::CreateDeserialized(Context, RawGlobalID);
+    D = TypeAliasTemplateDecl::CreateDeserialized(Context, ID);
     break;
   case DECL_CONCEPT:
-    D = ConceptDecl::CreateDeserialized(Context, RawGlobalID);
+    D = ConceptDecl::CreateDeserialized(Context, ID);
     break;
   case DECL_REQUIRES_EXPR_BODY:
-    D = RequiresExprBodyDecl::CreateDeserialized(Context, RawGlobalID);
+    D = RequiresExprBodyDecl::CreateDeserialized(Context, ID);
     break;
   case DECL_STATIC_ASSERT:
-    D = StaticAssertDecl::CreateDeserialized(Context, RawGlobalID);
+    D = StaticAssertDecl::CreateDeserialized(Context, ID);
     break;
   case DECL_OBJC_METHOD:
-    D = ObjCMethodDecl::CreateDeserialized(Context, RawGlobalID);
+    D = ObjCMethodDecl::CreateDeserialized(Context, ID);
     break;
   case DECL_OBJC_INTERFACE:
-    D = ObjCInterfaceDecl::CreateDeserialized(Context, RawGlobalID);
+    D = ObjCInterfaceDecl::CreateDeserialized(Context, ID);
     break;
   case DECL_OBJC_IVAR:
-    D = ObjCIvarDecl::CreateDeserialized(Context, RawGlobalID);
+    D = ObjCIvarDecl::CreateDeserialized(Context, ID);
     break;
   case DECL_OBJC_PROTOCOL:
-    D = ObjCProtocolDecl::CreateDeserialized(Context, RawGlobalID);
+    D = ObjCProtocolDecl::CreateDeserialized(Context, ID);
     break;
   case DECL_OBJC_AT_DEFS_FIELD:
-    D = ObjCAtDefsFieldDecl::CreateDeserialized(Context, RawGlobalID);
+    D = ObjCAtDefsFieldDecl::CreateDeserialized(Context, ID);
     break;
   case DECL_OBJC_CATEGORY:
-    D = ObjCCategoryDecl::CreateDeserialized(Context, RawGlobalID);
+    D = ObjCCategoryDecl::CreateDeserialized(Context, ID);
     break;
   case DECL_OBJC_CATEGORY_IMPL:
-    D = ObjCCategoryImplDecl::CreateDeserialized(Context, RawGlobalID);
+    D = ObjCCategoryImplDecl::CreateDeserialized(Context, ID);
     break;
   case DECL_OBJC_IMPLEMENTATION:
-    D = ObjCImplementationDecl::CreateDeserialized(Context, RawGlobalID);
+    D = ObjCImplementationDecl::CreateDeserialized(Context, ID);
     break;
   case DECL_OBJC_COMPATIBLE_ALIAS:
-    D = ObjCCompatibleAliasDecl::CreateDeserialized(Context, RawGlobalID);
+    D = ObjCCompatibleAliasDecl::CreateDeserialized(Context, ID);
     break;
   case DECL_OBJC_PROPERTY:
-    D = ObjCPropertyDecl::CreateDeserialized(Context, RawGlobalID);
+    D = ObjCPropertyDecl::CreateDeserialized(Context, ID);
     break;
   case DECL_OBJC_PROPERTY_IMPL:
-    D = ObjCPropertyImplDecl::CreateDeserialized(Context, RawGlobalID);
+    D = ObjCPropertyImplDecl::CreateDeserialized(Context, ID);
     break;
   case DECL_FIELD:
-    D = FieldDecl::CreateDeserialized(Context, RawGlobalID);
+    D = FieldDecl::CreateDeserialized(Context, ID);
     break;
   case DECL_INDIRECTFIELD:
-    D = IndirectFieldDecl::CreateDeserialized(Context, RawGlobalID);
+    D = IndirectFieldDecl::CreateDeserialized(Context, ID);
     break;
   case DECL_VAR:
-    D = VarDecl::CreateDeserialized(Context, RawGlobalID);
+    D = VarDecl::CreateDeserialized(Context, ID);
     break;
   case DECL_IMPLICIT_PARAM:
-    D = ImplicitParamDecl::CreateDeserialized(Context, RawGlobalID);
+    D = ImplicitParamDecl::CreateDeserialized(Context, ID);
     break;
   case DECL_PARM_VAR:
-    D = ParmVarDecl::CreateDeserialized(Context, RawGlobalID);
+    D = ParmVarDecl::CreateDeserialized(Context, ID);
     break;
   case DECL_DECOMPOSITION:
-    D = DecompositionDecl::CreateDeserialized(Context, RawGlobalID,
-                                              Record.readInt());
+    D = DecompositionDecl::CreateDeserialized(Context, ID, Record.readInt());
     break;
   case DECL_BINDING:
-    D = BindingDecl::CreateDeserialized(Context, RawGlobalID);
+    D = BindingDecl::CreateDeserialized(Context, ID);
     break;
   case DECL_FILE_SCOPE_ASM:
-    D = FileScopeAsmDecl::CreateDeserialized(Context, RawGlobalID);
+    D = FileScopeAsmDecl::CreateDeserialized(Context, ID);
     break;
   case DECL_TOP_LEVEL_STMT_DECL:
-    D = TopLevelStmtDecl::CreateDeserialized(Context, RawGlobalID);
+    D = TopLevelStmtDecl::CreateDeserialized(Context, ID);
     break;
   case DECL_BLOCK:
-    D = BlockDecl::CreateDeserialized(Context, RawGlobalID);
+    D = BlockDecl::CreateDeserialized(Context, ID);
     break;
   case DECL_MS_PROPERTY:
-    D = MSPropertyDecl::CreateDeserialized(Context, RawGlobalID);
+    D = MSPropertyDecl::CreateDeserialized(Context, ID);
     break;
   case DECL_MS_GUID:
-    D = MSGuidDecl::CreateDeserialized(Context, RawGlobalID);
+    D = MSGuidDecl::CreateDeserialized(Context, ID);
     break;
   case DECL_UNNAMED_GLOBAL_CONSTANT:
-    D = UnnamedGlobalConstantDecl::CreateDeserialized(Context, RawGlobalID);
+    D = UnnamedGlobalConstantDecl::CreateDeserialized(Context, ID);
     break;
   case DECL_TEMPLATE_PARAM_OBJECT:
-    D = TemplateParamObjectDecl::CreateDeserialized(Context, RawGlobalID);
+    D = TemplateParamObjectDecl::CreateDeserialized(Context, ID);
     break;
   case DECL_CAPTURED:
-    D = CapturedDecl::CreateDeserialized(Context, RawGlobalID,
-                                         Record.readInt());
+    D = CapturedDecl::CreateDeserialized(Context, ID, Record.readInt());
     break;
   case DECL_CXX_BASE_SPECIFIERS:
     Error("attempt to read a C++ base-specifier record as a declaration");
@@ -4073,66 +4063,62 @@ Decl *ASTReader::ReadDeclRecord(GlobalDeclID ID) {
   case DECL_IMPORT:
     // Note: last entry of the ImportDecl record is the number of stored source
     // locations.
-    D = ImportDecl::CreateDeserialized(Context, RawGlobalID, Record.back());
+    D = ImportDecl::CreateDeserialized(Context, ID, Record.back());
     break;
   case DECL_OMP_THREADPRIVATE: {
     Record.skipInts(1);
     unsigned NumChildren = Record.readInt();
     Record.skipInts(1);
-    D = OMPThreadPrivateDecl::CreateDeserialized(Context, RawGlobalID,
-                                                 NumChildren);
+    D = OMPThreadPrivateDecl::CreateDeserialized(Context, ID, NumChildren);
     break;
   }
   case DECL_OMP_ALLOCATE: {
     unsigned NumClauses = Record.readInt();
     unsigned NumVars = Record.readInt();
     Record.skipInts(1);
-    D = OMPAllocateDecl::CreateDeserialized(Context, RawGlobalID, NumVars,
-                                            NumClauses);
+    D = OMPAllocateDecl::CreateDeserialized(Context, ID, NumVars, NumClauses);
     break;
   }
   case DECL_OMP_REQUIRES: {
     unsigned NumClauses = Record.readInt();
     Record.skipInts(2);
-    D = OMPRequiresDecl::CreateDeserialized(Context, RawGlobalID, NumClauses);
+    D = OMPRequiresDecl::CreateDeserialized(Context, ID, NumClauses);
     break;
   }
   case DECL_OMP_DECLARE_REDUCTION:
-    D = OMPDeclareReductionDecl::CreateDeserialized(Context, RawGlobalID);
+    D = OMPDeclareReductionDecl::CreateDeserialized(Context, ID);
     break;
   case DECL_OMP_DECLARE_MAPPER: {
     unsigned NumClauses = Record.readInt();
     Record.skipInts(2);
-    D = OMPDeclareMapperDecl::CreateDeserialized(Context, RawGlobalID,
-                                                 NumClauses);
+    D = OMPDeclareMapperDecl::CreateDeserialized(Context, ID, NumClauses);
     break;
   }
   case DECL_OMP_CAPTUREDEXPR:
-    D = OMPCapturedExprDecl::CreateDeserialized(Context, RawGlobalID);
+    D = OMPCapturedExprDecl::CreateDeserialized(Context, ID);
     break;
   case DECL_PRAGMA_COMMENT:
-    D = PragmaCommentDecl::CreateDeserialized(Context, RawGlobalID,
-                                              Record.readInt());
+    D = PragmaCommentDecl::CreateDeserialized(Context, ID, Record.readInt());
     break;
   case DECL_PRAGMA_DETECT_MISMATCH:
-    D = PragmaDetectMismatchDecl::CreateDeserialized(Context, RawGlobalID,
+    D = PragmaDetectMismatchDecl::CreateDeserialized(Context, ID,
                                                      Record.readInt());
     break;
   case DECL_EMPTY:
-    D = EmptyDecl::CreateDeserialized(Context, RawGlobalID);
+    D = EmptyDecl::CreateDeserialized(Context, ID);
     break;
   case DECL_LIFETIME_EXTENDED_TEMPORARY:
-    D = LifetimeExtendedTemporaryDecl::CreateDeserialized(Context, RawGlobalID);
+    D = LifetimeExtendedTemporaryDecl::CreateDeserialized(Context, ID);
     break;
   case DECL_OBJC_TYPE_PARAM:
-    D = ObjCTypeParamDecl::CreateDeserialized(Context, RawGlobalID);
+    D = ObjCTypeParamDecl::CreateDeserialized(Context, ID);
     break;
   case DECL_HLSL_BUFFER:
-    D = HLSLBufferDecl::CreateDeserialized(Context, RawGlobalID);
+    D = HLSLBufferDecl::CreateDeserialized(Context, ID);
     break;
   case DECL_IMPLICIT_CONCEPT_SPECIALIZATION:
-    D = ImplicitConceptSpecializationDecl::CreateDeserialized(
-        Context, RawGlobalID, Record.readInt());
+    D = ImplicitConceptSpecializationDecl::CreateDeserialized(Context, ID,
+                                                              Record.readInt());
     break;
   }
 
@@ -4424,8 +4410,9 @@ namespace {
       // Map global ID of the definition down to the local ID used in this
       // module file. If there is no such mapping, we'll find nothing here
       // (or in any module it imports).
-      DeclID LocalID = Reader.mapGlobalIDToModuleFileGlobalID(M, InterfaceID);
-      if (!LocalID)
+      LocalDeclID LocalID =
+          Reader.mapGlobalIDToModuleFileGlobalID(M, InterfaceID);
+      if (LocalID.isInvalid())
         return true;
 
       // Perform a binary search to find the local redeclarations for this
diff --git a/clang/lib/Serialization/ASTWriter.cpp b/clang/lib/Serialization/ASTWriter.cpp
index 842ea58..0408eeb 100644
--- a/clang/lib/Serialization/ASTWriter.cpp
+++ b/clang/lib/Serialization/ASTWriter.cpp
@@ -3043,7 +3043,7 @@ void ASTWriter::WriteSubmodules(Module *WritingModule) {
     RecordData Inits;
     for (Decl *D : Context->getModuleInitializers(Mod))
       if (wasDeclEmitted(D))
-        Inits.push_back(GetDeclRef(D));
+        AddDeclRef(D, Inits);
     if (!Inits.empty())
       Stream.EmitRecord(SUBMODULE_INITIALIZERS, Inits);
 
@@ -3226,7 +3226,7 @@ uint64_t ASTWriter::WriteDeclContextLexicalBlock(ASTContext &Context,
       continue;
 
     KindDeclPairs.push_back(D->getKind());
-    KindDeclPairs.push_back(GetDeclRef(D));
+    KindDeclPairs.push_back(GetDeclRef(D).get());
   }
 
   ++NumLexicalDeclContexts;
@@ -3261,7 +3261,7 @@ void ASTWriter::WriteTypeDeclOffsets() {
   unsigned DeclOffsetAbbrev = Stream.EmitAbbrev(std::move(Abbrev));
   {
     RecordData::value_type Record[] = {DECL_OFFSET, DeclOffsets.size(),
-                                       FirstDeclID - NUM_PREDEF_DECL_IDS};
+                                       FirstDeclID.get() - NUM_PREDEF_DECL_IDS};
     Stream.EmitRecordWithBlob(DeclOffsetAbbrev, Record, bytes(DeclOffsets));
   }
 }
@@ -3282,7 +3282,7 @@ void ASTWriter::WriteFileDeclIDsMap() {
     Info.FirstDeclIndex = FileGroupedDeclIDs.size();
     llvm::stable_sort(Info.DeclIDs);
     for (auto &LocDeclEntry : Info.DeclIDs)
-      FileGroupedDeclIDs.push_back(LocDeclEntry.second);
+      FileGroupedDeclIDs.push_back(LocDeclEntry.second.get());
   }
 
   auto Abbrev = std::make_shared<BitCodeAbbrev>();
@@ -3420,11 +3420,11 @@ public:
     for (const ObjCMethodList *Method = &Methods.Instance; Method;
          Method = Method->getNext())
       if (ShouldWriteMethodListNode(Method))
-        LE.write<DeclID>(Writer.getDeclID(Method->getMethod()));
+        LE.write<DeclID>((DeclID)Writer.getDeclID(Method->getMethod()));
     for (const ObjCMethodList *Method = &Methods.Factory; Method;
          Method = Method->getNext())
       if (ShouldWriteMethodListNode(Method))
-        LE.write<DeclID>(Writer.getDeclID(Method->getMethod()));
+        LE.write<DeclID>((DeclID)Writer.getDeclID(Method->getMethod()));
 
     assert(Out.tell() - Start == DataLen && "Data length is wrong");
   }
@@ -3743,8 +3743,8 @@ public:
       // Only emit declarations that aren't from a chained PCH, though.
       SmallVector<NamedDecl *, 16> Decls(IdResolver.decls(II));
       for (NamedDecl *D : llvm::reverse(Decls))
-        LE.write<DeclID>(
-            Writer.getDeclID(getDeclForLocalLookup(PP.getLangOpts(), D)));
+        LE.write<DeclID>((DeclID)Writer.getDeclID(
+            getDeclForLocalLookup(PP.getLangOpts(), D)));
     }
   }
 };
@@ -3860,7 +3860,7 @@ namespace {
 // Trait used for the on-disk hash table used in the method pool.
 class ASTDeclContextNameLookupTrait {
   ASTWriter &Writer;
-  llvm::SmallVector<DeclID, 64> DeclIDs;
+  llvm::SmallVector<LocalDeclID, 64> DeclIDs;
 
 public:
   using key_type = DeclarationNameKey;
@@ -3893,8 +3893,10 @@ public:
 
   data_type ImportData(const reader::ASTDeclContextNameLookupTrait::data_type &FromReader) {
     unsigned Start = DeclIDs.size();
-    DeclIDs.insert(DeclIDs.end(), DeclIDIterator(FromReader.begin()),
-                   DeclIDIterator(FromReader.end()));
+    DeclIDs.insert(
+        DeclIDs.end(),
+        DeclIDIterator<GlobalDeclID, LocalDeclID>(FromReader.begin()),
+        DeclIDIterator<GlobalDeclID, LocalDeclID>(FromReader.end()));
     return std::make_pair(Start, DeclIDs.size());
   }
 
@@ -3983,7 +3985,7 @@ public:
     endian::Writer LE(Out, llvm::endianness::little);
     uint64_t Start = Out.tell(); (void)Start;
     for (unsigned I = Lookup.first, N = Lookup.second; I != N; ++I)
-      LE.write<DeclID>(DeclIDs[I]);
+      LE.write<DeclID>((DeclID)DeclIDs[I]);
     assert(Out.tell() - Start == DataLen && "Data length is wrong");
   }
 };
@@ -4317,7 +4319,8 @@ void ASTWriter::WriteDeclContextVisibleUpdate(const DeclContext *DC) {
     DC = cast<DeclContext>(Chain->getKeyDeclaration(cast<Decl>(DC)));
 
   // Write the lookup table
-  RecordData::value_type Record[] = {UPDATE_VISIBLE, getDeclID(cast<Decl>(DC))};
+  RecordData::value_type Record[] = {UPDATE_VISIBLE,
+                                     getDeclID(cast<Decl>(DC)).get()};
   Stream.EmitRecordWithBlob(UpdateVisibleAbbrev, Record, LookupTable);
 }
 
@@ -4371,7 +4374,7 @@ void ASTWriter::WriteObjCCategories() {
            Cat = Class->known_categories_begin(),
            CatEnd = Class->known_categories_end();
          Cat != CatEnd; ++Cat, ++Size) {
-      assert(getDeclID(*Cat) != 0 && "Bogus category");
+      assert(getDeclID(*Cat).isValid() && "Bogus category");
       AddDeclRef(*Cat, Categories);
     }
 
@@ -5089,7 +5092,7 @@ void ASTWriter::WriteSpecialDeclRecords(Sema &SemaRef) {
       if (!D || !wasDeclEmitted(D))
         SemaDeclRefs.push_back(0);
       else
-        SemaDeclRefs.push_back(getDeclID(D));
+        AddDeclRef(D, SemaDeclRefs);
     };
 
     AddEmittedDeclRefOrZero(SemaRef.getStdNamespace());
@@ -5100,10 +5103,10 @@ void ASTWriter::WriteSpecialDeclRecords(Sema &SemaRef) {
     Stream.EmitRecord(SEMA_DECL_REFS, SemaDeclRefs);
 
   // Write the record containing decls to be checked for deferred diags.
-  SmallVector<DeclID, 64> DeclsToCheckForDeferredDiags;
+  RecordData DeclsToCheckForDeferredDiags;
   for (auto *D : SemaRef.DeclsToCheckForDeferredDiags)
     if (wasDeclEmitted(D))
-      DeclsToCheckForDeferredDiags.push_back(getDeclID(D));
+      AddDeclRef(D, DeclsToCheckForDeferredDiags);
   if (!DeclsToCheckForDeferredDiags.empty())
     Stream.EmitRecord(DECLS_TO_CHECK_FOR_DEFERRED_DIAGS,
         DeclsToCheckForDeferredDiags);
@@ -5473,7 +5476,7 @@ void ASTWriter::WriteDeclAndTypes(ASTContext &Context) {
     if (VisibleOffset)
       VisibleOffset -= DeclTypesBlockStartOffset;
 
-    DelayedNamespaceRecord.push_back(getDeclID(NS));
+    AddDeclRef(NS, DelayedNamespaceRecord);
     DelayedNamespaceRecord.push_back(LexicalOffset);
     DelayedNamespaceRecord.push_back(VisibleOffset);
   }
@@ -5507,7 +5510,7 @@ void ASTWriter::WriteDeclAndTypes(ASTContext &Context) {
       continue;
 
     NewGlobalKindDeclPairs.push_back(D->getKind());
-    NewGlobalKindDeclPairs.push_back(GetDeclRef(D));
+    NewGlobalKindDeclPairs.push_back(GetDeclRef(D).get());
   }
 
   auto Abv = std::make_shared<llvm::BitCodeAbbrev>();
@@ -5568,7 +5571,7 @@ void ASTWriter::WriteDeclUpdatesBlocks(RecordDataImpl &OffsetsRecord) {
       case UPD_CXX_ADDED_TEMPLATE_SPECIALIZATION:
       case UPD_CXX_ADDED_ANONYMOUS_NAMESPACE:
         assert(Update.getDecl() && "no decl to add?");
-        Record.push_back(GetDeclRef(Update.getDecl()));
+        Record.AddDeclRef(Update.getDecl());
         break;
 
       case UPD_CXX_ADDED_FUNCTION_DEFINITION:
@@ -5709,7 +5712,7 @@ void ASTWriter::WriteDeclUpdatesBlocks(RecordDataImpl &OffsetsRecord) {
       }
     }
 
-    OffsetsRecord.push_back(GetDeclRef(D));
+    AddDeclRef(D, OffsetsRecord);
     OffsetsRecord.push_back(Record.Emit(DECL_UPDATES));
   }
 }
@@ -5974,18 +5977,18 @@ void ASTWriter::AddEmittedDeclRef(const Decl *D, RecordDataImpl &Record) {
   if (!wasDeclEmitted(D))
     return;
 
-  Record.push_back(GetDeclRef(D));
+  Record.push_back(GetDeclRef(D).get());
 }
 
 void ASTWriter::AddDeclRef(const Decl *D, RecordDataImpl &Record) {
-  Record.push_back(GetDeclRef(D));
+  Record.push_back(GetDeclRef(D).get());
 }
 
-DeclID ASTWriter::GetDeclRef(const Decl *D) {
+LocalDeclID ASTWriter::GetDeclRef(const Decl *D) {
   assert(WritingAST && "Cannot request a declaration ID before AST writing");
 
   if (!D) {
-    return 0;
+    return LocalDeclID();
   }
 
   // If the DeclUpdate from the GMF gets touched, emit it.
@@ -5999,14 +6002,14 @@ DeclID ASTWriter::GetDeclRef(const Decl *D) {
   // If D comes from an AST file, its declaration ID is already known and
   // fixed.
   if (D->isFromASTFile())
-    return D->getGlobalID();
+    return LocalDeclID(D->getGlobalID());
 
   assert(!(reinterpret_cast<uintptr_t>(D) & 0x01) && "Invalid decl pointer");
-  DeclID &ID = DeclIDs[D];
-  if (ID == 0) {
+  LocalDeclID &ID = DeclIDs[D];
+  if (ID.isInvalid()) {
     if (DoneWritingDeclsAndTypes) {
       assert(0 && "New decl seen after serializing all the decls to emit!");
-      return 0;
+      return LocalDeclID();
     }
 
     // We haven't seen this declaration before. Give it a new ID and
@@ -6018,14 +6021,14 @@ DeclID ASTWriter::GetDeclRef(const Decl *D) {
   return ID;
 }
 
-DeclID ASTWriter::getDeclID(const Decl *D) {
+LocalDeclID ASTWriter::getDeclID(const Decl *D) {
   if (!D)
-    return 0;
+    return LocalDeclID();
 
   // If D comes from an AST file, its declaration ID is already known and
   // fixed.
   if (D->isFromASTFile())
-    return D->getGlobalID();
+    return LocalDeclID(D->getGlobalID());
 
   assert(DeclIDs.contains(D) && "Declaration not emitted!");
   return DeclIDs[D];
@@ -6046,8 +6049,8 @@ bool ASTWriter::wasDeclEmitted(const Decl *D) const {
   return Emitted;
 }
 
-void ASTWriter::associateDeclWithFile(const Decl *D, DeclID ID) {
-  assert(ID);
+void ASTWriter::associateDeclWithFile(const Decl *D, LocalDeclID ID) {
+  assert(ID.isValid());
   assert(D);
 
   SourceLocation Loc = D->getLocation();
@@ -6079,7 +6082,7 @@ void ASTWriter::associateDeclWithFile(const Decl *D, DeclID ID) {
   if (!Info)
     Info = std::make_unique<DeclIDInFileInfo>();
 
-  std::pair<unsigned, DeclID> LocDecl(Offset, ID);
+  std::pair<unsigned, LocalDeclID> LocDecl(Offset, ID);
   LocDeclIDsTy &Decls = Info->DeclIDs;
   Decls.push_back(LocDecl);
 }
@@ -6349,7 +6352,7 @@ void ASTRecordWriter::AddCXXDefinitionData(const CXXRecordDecl *D) {
       Writer->Context->getLangOpts().ModulesDebugInfo && !D->isDependentType();
   Record->push_back(ModulesDebugInfo);
   if (ModulesDebugInfo)
-    Writer->ModularCodegenDecls.push_back(Writer->GetDeclRef(D));
+    Writer->AddDeclRef(D, Writer->ModularCodegenDecls);
 
   // IsLambda bit is already saved.
 
@@ -6453,7 +6456,7 @@ void ASTWriter::ReaderInitialized(ASTReader *Reader) {
 
   // Note, this will get called multiple times, once one the reader starts up
   // and again each time it's done reading a PCH or module.
-  FirstDeclID = NUM_PREDEF_DECL_IDS + Chain->getTotalNumDecls();
+  FirstDeclID = LocalDeclID(NUM_PREDEF_DECL_IDS + Chain->getTotalNumDecls());
   FirstTypeID = NUM_PREDEF_TYPE_IDS + Chain->getTotalNumTypes();
   FirstIdentID = NUM_PREDEF_IDENT_IDS + Chain->getTotalNumIdentifiers();
   FirstMacroID = NUM_PREDEF_MACRO_IDS + Chain->getTotalNumMacros();
diff --git a/clang/lib/Serialization/ASTWriterDecl.cpp b/clang/lib/Serialization/ASTWriterDecl.cpp
index fe86719..0edc4fed 100644
--- a/clang/lib/Serialization/ASTWriterDecl.cpp
+++ b/clang/lib/Serialization/ASTWriterDecl.cpp
@@ -223,9 +223,9 @@ namespace clang {
         assert(!Common->LazySpecializations);
       }
 
-      ArrayRef<DeclID> LazySpecializations;
+      ArrayRef<GlobalDeclID> LazySpecializations;
       if (auto *LS = Common->LazySpecializations)
-        LazySpecializations = llvm::ArrayRef(LS + 1, LS[0]);
+        LazySpecializations = llvm::ArrayRef(LS + 1, LS[0].get());
 
       // Add a slot to the record for the number of specializations.
       unsigned I = Record.size();
@@ -243,7 +243,9 @@ namespace clang {
         assert(D->isCanonicalDecl() && "non-canonical decl in set");
         AddFirstDeclFromEachModule(D, /*IncludeLocal*/true);
       }
-      Record.append(LazySpecializations.begin(), LazySpecializations.end());
+      Record.append(
+          DeclIDIterator<GlobalDeclID, DeclID>(LazySpecializations.begin()),
+          DeclIDIterator<GlobalDeclID, DeclID>(LazySpecializations.end()));
 
       // Update the size entry we added earlier.
       Record[I] = Record.size() - I - 1;
@@ -1166,7 +1168,7 @@ void ASTDeclWriter::VisitVarDecl(VarDecl *D) {
   Record.push_back(VarDeclBits);
 
   if (ModulesCodegen)
-    Writer.ModularCodegenDecls.push_back(Writer.GetDeclRef(D));
+    Writer.AddDeclRef(D, Writer.ModularCodegenDecls);
 
   if (D->hasAttr<BlocksAttr>()) {
     BlockVarCopyInit Init = Writer.Context->getBlockVarCopyInit(D);
@@ -2786,10 +2788,10 @@ void ASTWriter::WriteDecl(ASTContext &Context, Decl *D) {
                                       "serializing");
 
   // Determine the ID for this declaration.
-  DeclID ID;
+  LocalDeclID ID;
   assert(!D->isFromASTFile() && "should not be emitting imported decl");
-  DeclID &IDR = DeclIDs[D];
-  if (IDR == 0)
+  LocalDeclID &IDR = DeclIDs[D];
+  if (IDR.isInvalid())
     IDR = NextDeclID++;
 
   ID = IDR;
@@ -2807,7 +2809,7 @@ void ASTWriter::WriteDecl(ASTContext &Context, Decl *D) {
 
   // Record the offset for this declaration
   SourceLocation Loc = D->getLocation();
-  unsigned Index = ID - FirstDeclID;
+  unsigned Index = ID.get() - FirstDeclID.get();
   if (DeclOffsets.size() == Index)
     DeclOffsets.emplace_back(getAdjustedLocation(Loc), Offset,
                              DeclTypesBlockStartOffset);
@@ -2827,7 +2829,7 @@ void ASTWriter::WriteDecl(ASTContext &Context, Decl *D) {
   // Note declarations that should be deserialized eagerly so that we can add
   // them to a record in the AST file later.
   if (isRequiredDecl(D, Context, WritingModule))
-    EagerlyDeserializedDecls.push_back(ID);
+    AddDeclRef(D, EagerlyDeserializedDecls);
 }
 
 void ASTRecordWriter::AddFunctionDefinition(const FunctionDecl *FD) {
@@ -2863,7 +2865,7 @@ void ASTRecordWriter::AddFunctionDefinition(const FunctionDecl *FD) {
   }
   Record->push_back(ModulesCodegen);
   if (ModulesCodegen)
-    Writer->ModularCodegenDecls.push_back(Writer->GetDeclRef(FD));
+    Writer->AddDeclRef(FD, Writer->ModularCodegenDecls);
   if (auto *CD = dyn_cast<CXXConstructorDecl>(FD)) {
     Record->push_back(CD->getNumCtorInitializers());
     if (CD->getNumCtorInitializers())
author	Chuanqi Xu <yedeng.yd@linux.alibaba.com>	2024-04-25 11:43:13 +0800
committer	Chuanqi Xu <yedeng.yd@linux.alibaba.com>	2024-04-25 14:14:05 +0800
commit	42070a5c092ed420bf92ebf38229c594885e94c7 (patch)
tree	843afa1cc0c179d42d2dc0ed8a2dada5964a6734 /clang/lib
parent	c2a98fdeb3aede1a8db492a6ea30f4fa85b60edc (diff)
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