clang/lib/Serialization/ASTWriterDecl.cpp

   1 //===--- ASTWriterDecl.cpp - Declaration Serialization --------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 //  This file implements serialization for Declarations.
  10 //
  11 //===----------------------------------------------------------------------===//
  12
  13 #include "ASTCommon.h"
  14 #include "clang/AST/Attr.h"
  15 #include "clang/AST/DeclCXX.h"
  16 #include "clang/AST/DeclTemplate.h"
  17 #include "clang/AST/DeclVisitor.h"
  18 #include "clang/AST/Expr.h"
  19 #include "clang/AST/OpenMPClause.h"
  20 #include "clang/AST/PrettyDeclStackTrace.h"
  21 #include "clang/Basic/SourceManager.h"
  22 #include "clang/Serialization/ASTReader.h"
  23 #include "clang/Serialization/ASTRecordWriter.h"
  24 #include "llvm/Bitstream/BitstreamWriter.h"
  25 #include "llvm/Support/ErrorHandling.h"
  26 using namespace clang;
  27 using namespace serialization;
  28
  29 //===----------------------------------------------------------------------===//
  30 // Declaration serialization
  31 //===----------------------------------------------------------------------===//
  32
  33 namespace clang {
  34   class ASTDeclWriter : public DeclVisitor<ASTDeclWriter, void> {
  35     ASTWriter &Writer;
  36     ASTContext &Context;
  37     ASTRecordWriter Record;
  38
  39     serialization::DeclCode Code;
  40     unsigned AbbrevToUse;
  41
  42   public:
  43     ASTDeclWriter(ASTWriter &Writer, ASTContext &Context,
  44                   ASTWriter::RecordDataImpl &Record)
  45         : Writer(Writer), Context(Context), Record(Writer, Record),
  46           Code((serialization::DeclCode)0), AbbrevToUse(0) {}
  47
  48     uint64_t Emit(Decl *D) {
  49       if (!Code)
  50         llvm::report_fatal_error(StringRef("unexpected declaration kind '") +
  51             D->getDeclKindName() + "'");
  52       return Record.Emit(Code, AbbrevToUse);
  53     }
  54
  55     void Visit(Decl *D);
  56
  57     void VisitDecl(Decl *D);
  58     void VisitPragmaCommentDecl(PragmaCommentDecl *D);
  59     void VisitPragmaDetectMismatchDecl(PragmaDetectMismatchDecl *D);
  60     void VisitTranslationUnitDecl(TranslationUnitDecl *D);
  61     void VisitNamedDecl(NamedDecl *D);
  62     void VisitLabelDecl(LabelDecl *LD);
  63     void VisitNamespaceDecl(NamespaceDecl *D);
  64     void VisitUsingDirectiveDecl(UsingDirectiveDecl *D);
  65     void VisitNamespaceAliasDecl(NamespaceAliasDecl *D);
  66     void VisitTypeDecl(TypeDecl *D);
  67     void VisitTypedefNameDecl(TypedefNameDecl *D);
  68     void VisitTypedefDecl(TypedefDecl *D);
  69     void VisitTypeAliasDecl(TypeAliasDecl *D);
  70     void VisitUnresolvedUsingTypenameDecl(UnresolvedUsingTypenameDecl *D);
  71     void VisitUnresolvedUsingIfExistsDecl(UnresolvedUsingIfExistsDecl *D);
  72     void VisitTagDecl(TagDecl *D);
  73     void VisitEnumDecl(EnumDecl *D);
  74     void VisitRecordDecl(RecordDecl *D);
  75     void VisitCXXRecordDecl(CXXRecordDecl *D);
  76     void VisitClassTemplateSpecializationDecl(
  77                                             ClassTemplateSpecializationDecl *D);
  78     void VisitClassTemplatePartialSpecializationDecl(
  79                                      ClassTemplatePartialSpecializationDecl *D);
  80     void VisitVarTemplateSpecializationDecl(VarTemplateSpecializationDecl *D);
  81     void VisitVarTemplatePartialSpecializationDecl(
  82         VarTemplatePartialSpecializationDecl *D);
  83     void VisitClassScopeFunctionSpecializationDecl(
  84                                        ClassScopeFunctionSpecializationDecl *D);
  85     void VisitTemplateTypeParmDecl(TemplateTypeParmDecl *D);
  86     void VisitValueDecl(ValueDecl *D);
  87     void VisitEnumConstantDecl(EnumConstantDecl *D);
  88     void VisitUnresolvedUsingValueDecl(UnresolvedUsingValueDecl *D);
  89     void VisitDeclaratorDecl(DeclaratorDecl *D);
  90     void VisitFunctionDecl(FunctionDecl *D);
  91     void VisitCXXDeductionGuideDecl(CXXDeductionGuideDecl *D);
  92     void VisitCXXMethodDecl(CXXMethodDecl *D);
  93     void VisitCXXConstructorDecl(CXXConstructorDecl *D);
  94     void VisitCXXDestructorDecl(CXXDestructorDecl *D);
  95     void VisitCXXConversionDecl(CXXConversionDecl *D);
  96     void VisitFieldDecl(FieldDecl *D);
  97     void VisitMSPropertyDecl(MSPropertyDecl *D);
  98     void VisitMSGuidDecl(MSGuidDecl *D);
  99     void VisitUnnamedGlobalConstantDecl(UnnamedGlobalConstantDecl *D);
 100     void VisitTemplateParamObjectDecl(TemplateParamObjectDecl *D);
 101     void VisitIndirectFieldDecl(IndirectFieldDecl *D);
 102     void VisitVarDecl(VarDecl *D);
 103     void VisitImplicitParamDecl(ImplicitParamDecl *D);
 104     void VisitParmVarDecl(ParmVarDecl *D);
 105     void VisitDecompositionDecl(DecompositionDecl *D);
 106     void VisitBindingDecl(BindingDecl *D);
 107     void VisitNonTypeTemplateParmDecl(NonTypeTemplateParmDecl *D);
 108     void VisitTemplateDecl(TemplateDecl *D);
 109     void VisitConceptDecl(ConceptDecl *D);
 110     void VisitRequiresExprBodyDecl(RequiresExprBodyDecl *D);
 111     void VisitRedeclarableTemplateDecl(RedeclarableTemplateDecl *D);
 112     void VisitClassTemplateDecl(ClassTemplateDecl *D);
 113     void VisitVarTemplateDecl(VarTemplateDecl *D);
 114     void VisitFunctionTemplateDecl(FunctionTemplateDecl *D);
 115     void VisitTemplateTemplateParmDecl(TemplateTemplateParmDecl *D);
 116     void VisitTypeAliasTemplateDecl(TypeAliasTemplateDecl *D);
 117     void VisitUsingDecl(UsingDecl *D);
 118     void VisitUsingEnumDecl(UsingEnumDecl *D);
 119     void VisitUsingPackDecl(UsingPackDecl *D);
 120     void VisitUsingShadowDecl(UsingShadowDecl *D);
 121     void VisitConstructorUsingShadowDecl(ConstructorUsingShadowDecl *D);
 122     void VisitLinkageSpecDecl(LinkageSpecDecl *D);
 123     void VisitExportDecl(ExportDecl *D);
 124     void VisitFileScopeAsmDecl(FileScopeAsmDecl *D);
 125     void VisitImportDecl(ImportDecl *D);
 126     void VisitAccessSpecDecl(AccessSpecDecl *D);
 127     void VisitFriendDecl(FriendDecl *D);
 128     void VisitFriendTemplateDecl(FriendTemplateDecl *D);
 129     void VisitStaticAssertDecl(StaticAssertDecl *D);
 130     void VisitBlockDecl(BlockDecl *D);
 131     void VisitCapturedDecl(CapturedDecl *D);
 132     void VisitEmptyDecl(EmptyDecl *D);
 133     void VisitLifetimeExtendedTemporaryDecl(LifetimeExtendedTemporaryDecl *D);
 134
 135     void VisitDeclContext(DeclContext *DC);
 136     template <typename T> void VisitRedeclarable(Redeclarable<T> *D);
 137
 138
 139     // FIXME: Put in the same order is DeclNodes.td?
 140     void VisitObjCMethodDecl(ObjCMethodDecl *D);
 141     void VisitObjCTypeParamDecl(ObjCTypeParamDecl *D);
 142     void VisitObjCContainerDecl(ObjCContainerDecl *D);
 143     void VisitObjCInterfaceDecl(ObjCInterfaceDecl *D);
 144     void VisitObjCIvarDecl(ObjCIvarDecl *D);
 145     void VisitObjCProtocolDecl(ObjCProtocolDecl *D);
 146     void VisitObjCAtDefsFieldDecl(ObjCAtDefsFieldDecl *D);
 147     void VisitObjCCategoryDecl(ObjCCategoryDecl *D);
 148     void VisitObjCImplDecl(ObjCImplDecl *D);
 149     void VisitObjCCategoryImplDecl(ObjCCategoryImplDecl *D);
 150     void VisitObjCImplementationDecl(ObjCImplementationDecl *D);
 151     void VisitObjCCompatibleAliasDecl(ObjCCompatibleAliasDecl *D);
 152     void VisitObjCPropertyDecl(ObjCPropertyDecl *D);
 153     void VisitObjCPropertyImplDecl(ObjCPropertyImplDecl *D);
 154     void VisitOMPThreadPrivateDecl(OMPThreadPrivateDecl *D);
 155     void VisitOMPAllocateDecl(OMPAllocateDecl *D);
 156     void VisitOMPRequiresDecl(OMPRequiresDecl *D);
 157     void VisitOMPDeclareReductionDecl(OMPDeclareReductionDecl *D);
 158     void VisitOMPDeclareMapperDecl(OMPDeclareMapperDecl *D);
 159     void VisitOMPCapturedExprDecl(OMPCapturedExprDecl *D);
 160
 161     /// Add an Objective-C type parameter list to the given record.
 162     void AddObjCTypeParamList(ObjCTypeParamList *typeParams) {
 163       // Empty type parameter list.
 164       if (!typeParams) {
 165         Record.push_back(0);
 166         return;
 167       }
 168
 169       Record.push_back(typeParams->size());
 170       for (auto typeParam : *typeParams) {
 171         Record.AddDeclRef(typeParam);
 172       }
 173       Record.AddSourceLocation(typeParams->getLAngleLoc());
 174       Record.AddSourceLocation(typeParams->getRAngleLoc());
 175     }
 176
 177     /// Add to the record the first declaration from each module file that
 178     /// provides a declaration of D. The intent is to provide a sufficient
 179     /// set such that reloading this set will load all current redeclarations.
 180     void AddFirstDeclFromEachModule(const Decl *D, bool IncludeLocal) {
 181       llvm::MapVector<ModuleFile*, const Decl*> Firsts;
 182       // FIXME: We can skip entries that we know are implied by others.
 183       for (const Decl *R = D->getMostRecentDecl(); R; R = R->getPreviousDecl()) {
 184         if (R->isFromASTFile())
 185           Firsts[Writer.Chain->getOwningModuleFile(R)] = R;
 186         else if (IncludeLocal)
 187           Firsts[nullptr] = R;
 188       }
 189       for (const auto &F : Firsts)
 190         Record.AddDeclRef(F.second);
 191     }
 192
 193     /// Get the specialization decl from an entry in the specialization list.
 194     template <typename EntryType>
 195     typename RedeclarableTemplateDecl::SpecEntryTraits<EntryType>::DeclType *
 196     getSpecializationDecl(EntryType &T) {
 197       return RedeclarableTemplateDecl::SpecEntryTraits<EntryType>::getDecl(&T);
 198     }
 199
 200     /// Get the list of partial specializations from a template's common ptr.
 201     template<typename T>
 202     decltype(T::PartialSpecializations) &getPartialSpecializations(T *Common) {
 203       return Common->PartialSpecializations;
 204     }
 205     ArrayRef<Decl> getPartialSpecializations(FunctionTemplateDecl::Common *) {
 206       return None;
 207     }
 208
 209     template<typename DeclTy>
 210     void AddTemplateSpecializations(DeclTy *D) {
 211       auto *Common = D->getCommonPtr();
 212
 213       // If we have any lazy specializations, and the external AST source is
 214       // our chained AST reader, we can just write out the DeclIDs. Otherwise,
 215       // we need to resolve them to actual declarations.
 216       if (Writer.Chain != Writer.Context->getExternalSource() &&
 217           Common->LazySpecializations) {
 218         D->LoadLazySpecializations();
 219         assert(!Common->LazySpecializations);
 220       }
 221
 222       ArrayRef<DeclID> LazySpecializations;
 223       if (auto *LS = Common->LazySpecializations)
 224         LazySpecializations = llvm::makeArrayRef(LS + 1, LS[0]);
 225
 226       // Add a slot to the record for the number of specializations.
 227       unsigned I = Record.size();
 228       Record.push_back(0);
 229
 230       // AddFirstDeclFromEachModule might trigger deserialization, invalidating
 231       // *Specializations iterators.
 232       llvm::SmallVector<const Decl*, 16> Specs;
 233       for (auto &Entry : Common->Specializations)
 234         Specs.push_back(getSpecializationDecl(Entry));
 235       for (auto &Entry : getPartialSpecializations(Common))
 236         Specs.push_back(getSpecializationDecl(Entry));
 237
 238       for (auto *D : Specs) {
 239         assert(D->isCanonicalDecl() && "non-canonical decl in set");
 240         AddFirstDeclFromEachModule(D, /*IncludeLocal*/true);
 241       }
 242       Record.append(LazySpecializations.begin(), LazySpecializations.end());
 243
 244       // Update the size entry we added earlier.
 245       Record[I] = Record.size() - I - 1;
 246     }
 247
 248     /// Ensure that this template specialization is associated with the specified
 249     /// template on reload.
 250     void RegisterTemplateSpecialization(const Decl *Template,
 251                                         const Decl *Specialization) {
 252       Template = Template->getCanonicalDecl();
 253
 254       // If the canonical template is local, we'll write out this specialization
 255       // when we emit it.
 256       // FIXME: We can do the same thing if there is any local declaration of
 257       // the template, to avoid emitting an update record.
 258       if (!Template->isFromASTFile())
 259         return;
 260
 261       // We only need to associate the first local declaration of the
 262       // specialization. The other declarations will get pulled in by it.
 263       if (Writer.getFirstLocalDecl(Specialization) != Specialization)
 264         return;
 265
 266       Writer.DeclUpdates[Template].push_back(ASTWriter::DeclUpdate(
 267           UPD_CXX_ADDED_TEMPLATE_SPECIALIZATION, Specialization));
 268     }
 269   };
 270 }
 271
 272 void ASTDeclWriter::Visit(Decl *D) {
 273   DeclVisitor<ASTDeclWriter>::Visit(D);
 274
 275   // Source locations require array (variable-length) abbreviations.  The
 276   // abbreviation infrastructure requires that arrays are encoded last, so
 277   // we handle it here in the case of those classes derived from DeclaratorDecl
 278   if (DeclaratorDecl *DD = dyn_cast<DeclaratorDecl>(D)) {
 279     if (auto *TInfo = DD->getTypeSourceInfo())
 280       Record.AddTypeLoc(TInfo->getTypeLoc());
 281   }
 282
 283   // Handle FunctionDecl's body here and write it after all other Stmts/Exprs
 284   // have been written. We want it last because we will not read it back when
 285   // retrieving it from the AST, we'll just lazily set the offset.
 286   if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
 287     Record.push_back(FD->doesThisDeclarationHaveABody());
 288     if (FD->doesThisDeclarationHaveABody())
 289       Record.AddFunctionDefinition(FD);
 290   }
 291
 292   // If this declaration is also a DeclContext, write blocks for the
 293   // declarations that lexically stored inside its context and those
 294   // declarations that are visible from its context.
 295   if (DeclContext *DC = dyn_cast<DeclContext>(D))
 296     VisitDeclContext(DC);
 297 }
 298
 299 void ASTDeclWriter::VisitDecl(Decl *D) {
 300   Record.AddDeclRef(cast_or_null<Decl>(D->getDeclContext()));
 301   if (D->getDeclContext() != D->getLexicalDeclContext())
 302     Record.AddDeclRef(cast_or_null<Decl>(D->getLexicalDeclContext()));
 303   else
 304     Record.push_back(0);
 305   Record.push_back(D->isInvalidDecl());
 306   Record.push_back(D->hasAttrs());
 307   if (D->hasAttrs())
 308     Record.AddAttributes(D->getAttrs());
 309   Record.push_back(D->isImplicit());
 310   Record.push_back(D->isUsed(false));
 311   Record.push_back(D->isReferenced());
 312   Record.push_back(D->isTopLevelDeclInObjCContainer());
 313   Record.push_back(D->getAccess());
 314   Record.push_back((uint64_t)D->getModuleOwnershipKind());
 315   Record.push_back(Writer.getSubmoduleID(D->getOwningModule()));
 316
 317   // If this declaration injected a name into a context different from its
 318   // lexical context, and that context is an imported namespace, we need to
 319   // update its visible declarations to include this name.
 320   //
 321   // This happens when we instantiate a class with a friend declaration or a
 322   // function with a local extern declaration, for instance.
 323   //
 324   // FIXME: Can we handle this in AddedVisibleDecl instead?
 325   if (D->isOutOfLine()) {
 326     auto *DC = D->getDeclContext();
 327     while (auto *NS = dyn_cast<NamespaceDecl>(DC->getRedeclContext())) {
 328       if (!NS->isFromASTFile())
 329         break;
 330       Writer.UpdatedDeclContexts.insert(NS->getPrimaryContext());
 331       if (!NS->isInlineNamespace())
 332         break;
 333       DC = NS->getParent();
 334     }
 335   }
 336 }
 337
 338 void ASTDeclWriter::VisitPragmaCommentDecl(PragmaCommentDecl *D) {
 339   StringRef Arg = D->getArg();
 340   Record.push_back(Arg.size());
 341   VisitDecl(D);
 342   Record.AddSourceLocation(D->getBeginLoc());
 343   Record.push_back(D->getCommentKind());
 344   Record.AddString(Arg);
 345   Code = serialization::DECL_PRAGMA_COMMENT;
 346 }
 347
 348 void ASTDeclWriter::VisitPragmaDetectMismatchDecl(
 349     PragmaDetectMismatchDecl *D) {
 350   StringRef Name = D->getName();
 351   StringRef Value = D->getValue();
 352   Record.push_back(Name.size() + 1 + Value.size());
 353   VisitDecl(D);
 354   Record.AddSourceLocation(D->getBeginLoc());
 355   Record.AddString(Name);
 356   Record.AddString(Value);
 357   Code = serialization::DECL_PRAGMA_DETECT_MISMATCH;
 358 }
 359
 360 void ASTDeclWriter::VisitTranslationUnitDecl(TranslationUnitDecl *D) {
 361   llvm_unreachable("Translation units aren't directly serialized");
 362 }
 363
 364 void ASTDeclWriter::VisitNamedDecl(NamedDecl *D) {
 365   VisitDecl(D);
 366   Record.AddDeclarationName(D->getDeclName());
 367   Record.push_back(needsAnonymousDeclarationNumber(D)
 368                        ? Writer.getAnonymousDeclarationNumber(D)
 369                        : 0);
 370 }
 371
 372 void ASTDeclWriter::VisitTypeDecl(TypeDecl *D) {
 373   VisitNamedDecl(D);
 374   Record.AddSourceLocation(D->getBeginLoc());
 375   Record.AddTypeRef(QualType(D->getTypeForDecl(), 0));
 376 }
 377
 378 void ASTDeclWriter::VisitTypedefNameDecl(TypedefNameDecl *D) {
 379   VisitRedeclarable(D);
 380   VisitTypeDecl(D);
 381   Record.AddTypeSourceInfo(D->getTypeSourceInfo());
 382   Record.push_back(D->isModed());
 383   if (D->isModed())
 384     Record.AddTypeRef(D->getUnderlyingType());
 385   Record.AddDeclRef(D->getAnonDeclWithTypedefName(false));
 386 }
 387
 388 void ASTDeclWriter::VisitTypedefDecl(TypedefDecl *D) {
 389   VisitTypedefNameDecl(D);
 390   if (D->getDeclContext() == D->getLexicalDeclContext() &&
 391       !D->hasAttrs() &&
 392       !D->isImplicit() &&
 393       D->getFirstDecl() == D->getMostRecentDecl() &&
 394       !D->isInvalidDecl() &&
 395       !D->isTopLevelDeclInObjCContainer() &&
 396       !D->isModulePrivate() &&
 397       !needsAnonymousDeclarationNumber(D) &&
 398       D->getDeclName().getNameKind() == DeclarationName::Identifier)
 399     AbbrevToUse = Writer.getDeclTypedefAbbrev();
 400
 401   Code = serialization::DECL_TYPEDEF;
 402 }
 403
 404 void ASTDeclWriter::VisitTypeAliasDecl(TypeAliasDecl *D) {
 405   VisitTypedefNameDecl(D);
 406   Record.AddDeclRef(D->getDescribedAliasTemplate());
 407   Code = serialization::DECL_TYPEALIAS;
 408 }
 409
 410 void ASTDeclWriter::VisitTagDecl(TagDecl *D) {
 411   VisitRedeclarable(D);
 412   VisitTypeDecl(D);
 413   Record.push_back(D->getIdentifierNamespace());
 414   Record.push_back((unsigned)D->getTagKind()); // FIXME: stable encoding
 415   if (!isa<CXXRecordDecl>(D))
 416     Record.push_back(D->isCompleteDefinition());
 417   Record.push_back(D->isEmbeddedInDeclarator());
 418   Record.push_back(D->isFreeStanding());
 419   Record.push_back(D->isCompleteDefinitionRequired());
 420   Record.AddSourceRange(D->getBraceRange());
 421
 422   if (D->hasExtInfo()) {
 423     Record.push_back(1);
 424     Record.AddQualifierInfo(*D->getExtInfo());
 425   } else if (auto *TD = D->getTypedefNameForAnonDecl()) {
 426     Record.push_back(2);
 427     Record.AddDeclRef(TD);
 428     Record.AddIdentifierRef(TD->getDeclName().getAsIdentifierInfo());
 429   } else {
 430     Record.push_back(0);
 431   }
 432 }
 433
 434 void ASTDeclWriter::VisitEnumDecl(EnumDecl *D) {
 435   VisitTagDecl(D);
 436   Record.AddTypeSourceInfo(D->getIntegerTypeSourceInfo());
 437   if (!D->getIntegerTypeSourceInfo())
 438     Record.AddTypeRef(D->getIntegerType());
 439   Record.AddTypeRef(D->getPromotionType());
 440   Record.push_back(D->getNumPositiveBits());
 441   Record.push_back(D->getNumNegativeBits());
 442   Record.push_back(D->isScoped());
 443   Record.push_back(D->isScopedUsingClassTag());
 444   Record.push_back(D->isFixed());
 445   Record.push_back(D->getODRHash());
 446
 447   if (MemberSpecializationInfo *MemberInfo = D->getMemberSpecializationInfo()) {
 448     Record.AddDeclRef(MemberInfo->getInstantiatedFrom());
 449     Record.push_back(MemberInfo->getTemplateSpecializationKind());
 450     Record.AddSourceLocation(MemberInfo->getPointOfInstantiation());
 451   } else {
 452     Record.AddDeclRef(nullptr);
 453   }
 454
 455   if (D->getDeclContext() == D->getLexicalDeclContext() &&
 456       !D->hasAttrs() &&
 457       !D->isImplicit() &&
 458       !D->isUsed(false) &&
 459       !D->hasExtInfo() &&
 460       !D->getTypedefNameForAnonDecl() &&
 461       D->getFirstDecl() == D->getMostRecentDecl() &&
 462       !D->isInvalidDecl() &&
 463       !D->isReferenced() &&
 464       !D->isTopLevelDeclInObjCContainer() &&
 465       D->getAccess() == AS_none &&
 466       !D->isModulePrivate() &&
 467       !CXXRecordDecl::classofKind(D->getKind()) &&
 468       !D->getIntegerTypeSourceInfo() &&
 469       !D->getMemberSpecializationInfo() &&
 470       !needsAnonymousDeclarationNumber(D) &&
 471       D->getDeclName().getNameKind() == DeclarationName::Identifier)
 472     AbbrevToUse = Writer.getDeclEnumAbbrev();
 473
 474   Code = serialization::DECL_ENUM;
 475 }
 476
 477 void ASTDeclWriter::VisitRecordDecl(RecordDecl *D) {
 478   VisitTagDecl(D);
 479   Record.push_back(D->hasFlexibleArrayMember());
 480   Record.push_back(D->isAnonymousStructOrUnion());
 481   Record.push_back(D->hasObjectMember());
 482   Record.push_back(D->hasVolatileMember());
 483   Record.push_back(D->isNonTrivialToPrimitiveDefaultInitialize());
 484   Record.push_back(D->isNonTrivialToPrimitiveCopy());
 485   Record.push_back(D->isNonTrivialToPrimitiveDestroy());
 486   Record.push_back(D->hasNonTrivialToPrimitiveDefaultInitializeCUnion());
 487   Record.push_back(D->hasNonTrivialToPrimitiveDestructCUnion());
 488   Record.push_back(D->hasNonTrivialToPrimitiveCopyCUnion());
 489   Record.push_back(D->isParamDestroyedInCallee());
 490   Record.push_back(D->getArgPassingRestrictions());
 491
 492   if (D->getDeclContext() == D->getLexicalDeclContext() &&
 493       !D->hasAttrs() &&
 494       !D->isImplicit() &&
 495       !D->isUsed(false) &&
 496       !D->hasExtInfo() &&
 497       !D->getTypedefNameForAnonDecl() &&
 498       D->getFirstDecl() == D->getMostRecentDecl() &&
 499       !D->isInvalidDecl() &&
 500       !D->isReferenced() &&
 501       !D->isTopLevelDeclInObjCContainer() &&
 502       D->getAccess() == AS_none &&
 503       !D->isModulePrivate() &&
 504       !CXXRecordDecl::classofKind(D->getKind()) &&
 505       !needsAnonymousDeclarationNumber(D) &&
 506       D->getDeclName().getNameKind() == DeclarationName::Identifier)
 507     AbbrevToUse = Writer.getDeclRecordAbbrev();
 508
 509   Code = serialization::DECL_RECORD;
 510 }
 511
 512 void ASTDeclWriter::VisitValueDecl(ValueDecl *D) {
 513   VisitNamedDecl(D);
 514   Record.AddTypeRef(D->getType());
 515 }
 516
 517 void ASTDeclWriter::VisitEnumConstantDecl(EnumConstantDecl *D) {
 518   VisitValueDecl(D);
 519   Record.push_back(D->getInitExpr()? 1 : 0);
 520   if (D->getInitExpr())
 521     Record.AddStmt(D->getInitExpr());
 522   Record.AddAPSInt(D->getInitVal());
 523
 524   Code = serialization::DECL_ENUM_CONSTANT;
 525 }
 526
 527 void ASTDeclWriter::VisitDeclaratorDecl(DeclaratorDecl *D) {
 528   VisitValueDecl(D);
 529   Record.AddSourceLocation(D->getInnerLocStart());
 530   Record.push_back(D->hasExtInfo());
 531   if (D->hasExtInfo()) {
 532     DeclaratorDecl::ExtInfo *Info = D->getExtInfo();
 533     Record.AddQualifierInfo(*Info);
 534     Record.AddStmt(Info->TrailingRequiresClause);
 535   }
 536   // The location information is deferred until the end of the record.
 537   Record.AddTypeRef(D->getTypeSourceInfo() ? D->getTypeSourceInfo()->getType()
 538                                            : QualType());
 539 }
 540
 541 void ASTDeclWriter::VisitFunctionDecl(FunctionDecl *D) {
 542   VisitRedeclarable(D);
 543   VisitDeclaratorDecl(D);
 544   Record.AddDeclarationNameLoc(D->DNLoc, D->getDeclName());
 545   Record.push_back(D->getIdentifierNamespace());
 546
 547   // FunctionDecl's body is handled last at ASTWriterDecl::Visit,
 548   // after everything else is written.
 549   Record.push_back(static_cast<int>(D->getStorageClass())); // FIXME: stable encoding
 550   Record.push_back(D->isInlineSpecified());
 551   Record.push_back(D->isInlined());
 552   Record.push_back(D->isVirtualAsWritten());
 553   Record.push_back(D->isPure());
 554   Record.push_back(D->hasInheritedPrototype());
 555   Record.push_back(D->hasWrittenPrototype());
 556   Record.push_back(D->isDeletedBit());
 557   Record.push_back(D->isTrivial());
 558   Record.push_back(D->isTrivialForCall());
 559   Record.push_back(D->isDefaulted());
 560   Record.push_back(D->isExplicitlyDefaulted());
 561   Record.push_back(D->hasImplicitReturnZero());
 562   Record.push_back(static_cast<uint64_t>(D->getConstexprKind()));
 563   Record.push_back(D->usesSEHTry());
 564   Record.push_back(D->hasSkippedBody());
 565   Record.push_back(D->isMultiVersion());
 566   Record.push_back(D->isLateTemplateParsed());
 567   Record.push_back(D->getLinkageInternal());
 568   Record.AddSourceLocation(D->getEndLoc());
 569
 570   Record.push_back(D->getODRHash());
 571
 572   if (D->isDefaulted()) {
 573     if (auto *FDI = D->getDefaultedFunctionInfo()) {
 574       Record.push_back(FDI->getUnqualifiedLookups().size());
 575       for (DeclAccessPair P : FDI->getUnqualifiedLookups()) {
 576         Record.AddDeclRef(P.getDecl());
 577         Record.push_back(P.getAccess());
 578       }
 579     } else {
 580       Record.push_back(0);
 581     }
 582   }
 583
 584   Record.push_back(D->getTemplatedKind());
 585   switch (D->getTemplatedKind()) {
 586   case FunctionDecl::TK_NonTemplate:
 587     break;
 588   case FunctionDecl::TK_DependentNonTemplate:
 589     Record.AddDeclRef(D->getInstantiatedFromDecl());
 590     break;
 591   case FunctionDecl::TK_FunctionTemplate:
 592     Record.AddDeclRef(D->getDescribedFunctionTemplate());
 593     break;
 594   case FunctionDecl::TK_MemberSpecialization: {
 595     MemberSpecializationInfo *MemberInfo = D->getMemberSpecializationInfo();
 596     Record.AddDeclRef(MemberInfo->getInstantiatedFrom());
 597     Record.push_back(MemberInfo->getTemplateSpecializationKind());
 598     Record.AddSourceLocation(MemberInfo->getPointOfInstantiation());
 599     break;
 600   }
 601   case FunctionDecl::TK_FunctionTemplateSpecialization: {
 602     FunctionTemplateSpecializationInfo *
 603       FTSInfo = D->getTemplateSpecializationInfo();
 604
 605     RegisterTemplateSpecialization(FTSInfo->getTemplate(), D);
 606
 607     Record.AddDeclRef(FTSInfo->getTemplate());
 608     Record.push_back(FTSInfo->getTemplateSpecializationKind());
 609
 610     // Template arguments.
 611     Record.AddTemplateArgumentList(FTSInfo->TemplateArguments);
 612
 613     // Template args as written.
 614     Record.push_back(FTSInfo->TemplateArgumentsAsWritten != nullptr);
 615     if (FTSInfo->TemplateArgumentsAsWritten) {
 616       Record.push_back(FTSInfo->TemplateArgumentsAsWritten->NumTemplateArgs);
 617       for (int i=0, e = FTSInfo->TemplateArgumentsAsWritten->NumTemplateArgs;
 618              i!=e; ++i)
 619         Record.AddTemplateArgumentLoc(
 620             (*FTSInfo->TemplateArgumentsAsWritten)[i]);
 621       Record.AddSourceLocation(FTSInfo->TemplateArgumentsAsWritten->LAngleLoc);
 622       Record.AddSourceLocation(FTSInfo->TemplateArgumentsAsWritten->RAngleLoc);
 623     }
 624
 625     Record.AddSourceLocation(FTSInfo->getPointOfInstantiation());
 626
 627     if (MemberSpecializationInfo *MemberInfo =
 628         FTSInfo->getMemberSpecializationInfo()) {
 629       Record.push_back(1);
 630       Record.AddDeclRef(MemberInfo->getInstantiatedFrom());
 631       Record.push_back(MemberInfo->getTemplateSpecializationKind());
 632       Record.AddSourceLocation(MemberInfo->getPointOfInstantiation());
 633     } else {
 634       Record.push_back(0);
 635     }
 636
 637     if (D->isCanonicalDecl()) {
 638       // Write the template that contains the specializations set. We will
 639       // add a FunctionTemplateSpecializationInfo to it when reading.
 640       Record.AddDeclRef(FTSInfo->getTemplate()->getCanonicalDecl());
 641     }
 642     break;
 643   }
 644   case FunctionDecl::TK_DependentFunctionTemplateSpecialization: {
 645     DependentFunctionTemplateSpecializationInfo *
 646       DFTSInfo = D->getDependentSpecializationInfo();
 647
 648     // Templates.
 649     Record.push_back(DFTSInfo->getNumTemplates());
 650     for (int i=0, e = DFTSInfo->getNumTemplates(); i != e; ++i)
 651       Record.AddDeclRef(DFTSInfo->getTemplate(i));
 652
 653     // Templates args.
 654     Record.push_back(DFTSInfo->getNumTemplateArgs());
 655     for (int i=0, e = DFTSInfo->getNumTemplateArgs(); i != e; ++i)
 656       Record.AddTemplateArgumentLoc(DFTSInfo->getTemplateArg(i));
 657     Record.AddSourceLocation(DFTSInfo->getLAngleLoc());
 658     Record.AddSourceLocation(DFTSInfo->getRAngleLoc());
 659     break;
 660   }
 661   }
 662
 663   Record.push_back(D->param_size());
 664   for (auto P : D->parameters())
 665     Record.AddDeclRef(P);
 666   Code = serialization::DECL_FUNCTION;
 667 }
 668
 669 static void addExplicitSpecifier(ExplicitSpecifier ES,
 670                                  ASTRecordWriter &Record) {
 671   uint64_t Kind = static_cast<uint64_t>(ES.getKind());
 672   Kind = Kind << 1 | static_cast<bool>(ES.getExpr());
 673   Record.push_back(Kind);
 674   if (ES.getExpr()) {
 675     Record.AddStmt(ES.getExpr());
 676   }
 677 }
 678
 679 void ASTDeclWriter::VisitCXXDeductionGuideDecl(CXXDeductionGuideDecl *D) {
 680   addExplicitSpecifier(D->getExplicitSpecifier(), Record);
 681   Record.AddDeclRef(D->Ctor);
 682   VisitFunctionDecl(D);
 683   Record.push_back(D->isCopyDeductionCandidate());
 684   Code = serialization::DECL_CXX_DEDUCTION_GUIDE;
 685 }
 686
 687 void ASTDeclWriter::VisitObjCMethodDecl(ObjCMethodDecl *D) {
 688   VisitNamedDecl(D);
 689   // FIXME: convert to LazyStmtPtr?
 690   // Unlike C/C++, method bodies will never be in header files.
 691   bool HasBodyStuff = D->getBody() != nullptr;
 692   Record.push_back(HasBodyStuff);
 693   if (HasBodyStuff) {
 694     Record.AddStmt(D->getBody());
 695   }
 696   Record.AddDeclRef(D->getSelfDecl());
 697   Record.AddDeclRef(D->getCmdDecl());
 698   Record.push_back(D->isInstanceMethod());
 699   Record.push_back(D->isVariadic());
 700   Record.push_back(D->isPropertyAccessor());
 701   Record.push_back(D->isSynthesizedAccessorStub());
 702   Record.push_back(D->isDefined());
 703   Record.push_back(D->isOverriding());
 704   Record.push_back(D->hasSkippedBody());
 705
 706   Record.push_back(D->isRedeclaration());
 707   Record.push_back(D->hasRedeclaration());
 708   if (D->hasRedeclaration()) {
 709     assert(Context.getObjCMethodRedeclaration(D));
 710     Record.AddDeclRef(Context.getObjCMethodRedeclaration(D));
 711   }
 712
 713   // FIXME: stable encoding for @required/@optional
 714   Record.push_back(D->getImplementationControl());
 715   // FIXME: stable encoding for in/out/inout/bycopy/byref/oneway/nullability
 716   Record.push_back(D->getObjCDeclQualifier());
 717   Record.push_back(D->hasRelatedResultType());
 718   Record.AddTypeRef(D->getReturnType());
 719   Record.AddTypeSourceInfo(D->getReturnTypeSourceInfo());
 720   Record.AddSourceLocation(D->getEndLoc());
 721   Record.push_back(D->param_size());
 722   for (const auto *P : D->parameters())
 723     Record.AddDeclRef(P);
 724
 725   Record.push_back(D->getSelLocsKind());
 726   unsigned NumStoredSelLocs = D->getNumStoredSelLocs();
 727   SourceLocation *SelLocs = D->getStoredSelLocs();
 728   Record.push_back(NumStoredSelLocs);
 729   for (unsigned i = 0; i != NumStoredSelLocs; ++i)
 730     Record.AddSourceLocation(SelLocs[i]);
 731
 732   Code = serialization::DECL_OBJC_METHOD;
 733 }
 734
 735 void ASTDeclWriter::VisitObjCTypeParamDecl(ObjCTypeParamDecl *D) {
 736   VisitTypedefNameDecl(D);
 737   Record.push_back(D->Variance);
 738   Record.push_back(D->Index);
 739   Record.AddSourceLocation(D->VarianceLoc);
 740   Record.AddSourceLocation(D->ColonLoc);
 741
 742   Code = serialization::DECL_OBJC_TYPE_PARAM;
 743 }
 744
 745 void ASTDeclWriter::VisitObjCContainerDecl(ObjCContainerDecl *D) {
 746   VisitNamedDecl(D);
 747   Record.AddSourceLocation(D->getAtStartLoc());
 748   Record.AddSourceRange(D->getAtEndRange());
 749   // Abstract class (no need to define a stable serialization::DECL code).
 750 }
 751
 752 void ASTDeclWriter::VisitObjCInterfaceDecl(ObjCInterfaceDecl *D) {
 753   VisitRedeclarable(D);
 754   VisitObjCContainerDecl(D);
 755   Record.AddTypeRef(QualType(D->getTypeForDecl(), 0));
 756   AddObjCTypeParamList(D->TypeParamList);
 757
 758   Record.push_back(D->isThisDeclarationADefinition());
 759   if (D->isThisDeclarationADefinition()) {
 760     // Write the DefinitionData
 761     ObjCInterfaceDecl::DefinitionData &Data = D->data();
 762
 763     Record.AddTypeSourceInfo(D->getSuperClassTInfo());
 764     Record.AddSourceLocation(D->getEndOfDefinitionLoc());
 765     Record.push_back(Data.HasDesignatedInitializers);
 766
 767     // Write out the protocols that are directly referenced by the @interface.
 768     Record.push_back(Data.ReferencedProtocols.size());
 769     for (const auto *P : D->protocols())
 770       Record.AddDeclRef(P);
 771     for (const auto &PL : D->protocol_locs())
 772       Record.AddSourceLocation(PL);
 773
 774     // Write out the protocols that are transitively referenced.
 775     Record.push_back(Data.AllReferencedProtocols.size());
 776     for (ObjCList<ObjCProtocolDecl>::iterator
 777               P = Data.AllReferencedProtocols.begin(),
 778            PEnd = Data.AllReferencedProtocols.end();
 779          P != PEnd; ++P)
 780       Record.AddDeclRef(*P);
 781
 782
 783     if (ObjCCategoryDecl *Cat = D->getCategoryListRaw()) {
 784       // Ensure that we write out the set of categories for this class.
 785       Writer.ObjCClassesWithCategories.insert(D);
 786
 787       // Make sure that the categories get serialized.
 788       for (; Cat; Cat = Cat->getNextClassCategoryRaw())
 789         (void)Writer.GetDeclRef(Cat);
 790     }
 791   }
 792
 793   Code = serialization::DECL_OBJC_INTERFACE;
 794 }
 795
 796 void ASTDeclWriter::VisitObjCIvarDecl(ObjCIvarDecl *D) {
 797   VisitFieldDecl(D);
 798   // FIXME: stable encoding for @public/@private/@protected/@package
 799   Record.push_back(D->getAccessControl());
 800   Record.push_back(D->getSynthesize());
 801
 802   if (D->getDeclContext() == D->getLexicalDeclContext() &&
 803       !D->hasAttrs() &&
 804       !D->isImplicit() &&
 805       !D->isUsed(false) &&
 806       !D->isInvalidDecl() &&
 807       !D->isReferenced() &&
 808       !D->isModulePrivate() &&
 809       !D->getBitWidth() &&
 810       !D->hasExtInfo() &&
 811       D->getDeclName())
 812     AbbrevToUse = Writer.getDeclObjCIvarAbbrev();
 813
 814   Code = serialization::DECL_OBJC_IVAR;
 815 }
 816
 817 void ASTDeclWriter::VisitObjCProtocolDecl(ObjCProtocolDecl *D) {
 818   VisitRedeclarable(D);
 819   VisitObjCContainerDecl(D);
 820
 821   Record.push_back(D->isThisDeclarationADefinition());
 822   if (D->isThisDeclarationADefinition()) {
 823     Record.push_back(D->protocol_size());
 824     for (const auto *I : D->protocols())
 825       Record.AddDeclRef(I);
 826     for (const auto &PL : D->protocol_locs())
 827       Record.AddSourceLocation(PL);
 828   }
 829
 830   Code = serialization::DECL_OBJC_PROTOCOL;
 831 }
 832
 833 void ASTDeclWriter::VisitObjCAtDefsFieldDecl(ObjCAtDefsFieldDecl *D) {
 834   VisitFieldDecl(D);
 835   Code = serialization::DECL_OBJC_AT_DEFS_FIELD;
 836 }
 837
 838 void ASTDeclWriter::VisitObjCCategoryDecl(ObjCCategoryDecl *D) {
 839   VisitObjCContainerDecl(D);
 840   Record.AddSourceLocation(D->getCategoryNameLoc());
 841   Record.AddSourceLocation(D->getIvarLBraceLoc());
 842   Record.AddSourceLocation(D->getIvarRBraceLoc());
 843   Record.AddDeclRef(D->getClassInterface());
 844   AddObjCTypeParamList(D->TypeParamList);
 845   Record.push_back(D->protocol_size());
 846   for (const auto *I : D->protocols())
 847     Record.AddDeclRef(I);
 848   for (const auto &PL : D->protocol_locs())
 849     Record.AddSourceLocation(PL);
 850   Code = serialization::DECL_OBJC_CATEGORY;
 851 }
 852
 853 void ASTDeclWriter::VisitObjCCompatibleAliasDecl(ObjCCompatibleAliasDecl *D) {
 854   VisitNamedDecl(D);
 855   Record.AddDeclRef(D->getClassInterface());
 856   Code = serialization::DECL_OBJC_COMPATIBLE_ALIAS;
 857 }
 858
 859 void ASTDeclWriter::VisitObjCPropertyDecl(ObjCPropertyDecl *D) {
 860   VisitNamedDecl(D);
 861   Record.AddSourceLocation(D->getAtLoc());
 862   Record.AddSourceLocation(D->getLParenLoc());
 863   Record.AddTypeRef(D->getType());
 864   Record.AddTypeSourceInfo(D->getTypeSourceInfo());
 865   // FIXME: stable encoding
 866   Record.push_back((unsigned)D->getPropertyAttributes());
 867   Record.push_back((unsigned)D->getPropertyAttributesAsWritten());
 868   // FIXME: stable encoding
 869   Record.push_back((unsigned)D->getPropertyImplementation());
 870   Record.AddDeclarationName(D->getGetterName());
 871   Record.AddSourceLocation(D->getGetterNameLoc());
 872   Record.AddDeclarationName(D->getSetterName());
 873   Record.AddSourceLocation(D->getSetterNameLoc());
 874   Record.AddDeclRef(D->getGetterMethodDecl());
 875   Record.AddDeclRef(D->getSetterMethodDecl());
 876   Record.AddDeclRef(D->getPropertyIvarDecl());
 877   Code = serialization::DECL_OBJC_PROPERTY;
 878 }
 879
 880 void ASTDeclWriter::VisitObjCImplDecl(ObjCImplDecl *D) {
 881   VisitObjCContainerDecl(D);
 882   Record.AddDeclRef(D->getClassInterface());
 883   // Abstract class (no need to define a stable serialization::DECL code).
 884 }
 885
 886 void ASTDeclWriter::VisitObjCCategoryImplDecl(ObjCCategoryImplDecl *D) {
 887   VisitObjCImplDecl(D);
 888   Record.AddSourceLocation(D->getCategoryNameLoc());
 889   Code = serialization::DECL_OBJC_CATEGORY_IMPL;
 890 }
 891
 892 void ASTDeclWriter::VisitObjCImplementationDecl(ObjCImplementationDecl *D) {
 893   VisitObjCImplDecl(D);
 894   Record.AddDeclRef(D->getSuperClass());
 895   Record.AddSourceLocation(D->getSuperClassLoc());
 896   Record.AddSourceLocation(D->getIvarLBraceLoc());
 897   Record.AddSourceLocation(D->getIvarRBraceLoc());
 898   Record.push_back(D->hasNonZeroConstructors());
 899   Record.push_back(D->hasDestructors());
 900   Record.push_back(D->NumIvarInitializers);
 901   if (D->NumIvarInitializers)
 902     Record.AddCXXCtorInitializers(
 903         llvm::makeArrayRef(D->init_begin(), D->init_end()));
 904   Code = serialization::DECL_OBJC_IMPLEMENTATION;
 905 }
 906
 907 void ASTDeclWriter::VisitObjCPropertyImplDecl(ObjCPropertyImplDecl *D) {
 908   VisitDecl(D);
 909   Record.AddSourceLocation(D->getBeginLoc());
 910   Record.AddDeclRef(D->getPropertyDecl());
 911   Record.AddDeclRef(D->getPropertyIvarDecl());
 912   Record.AddSourceLocation(D->getPropertyIvarDeclLoc());
 913   Record.AddDeclRef(D->getGetterMethodDecl());
 914   Record.AddDeclRef(D->getSetterMethodDecl());
 915   Record.AddStmt(D->getGetterCXXConstructor());
 916   Record.AddStmt(D->getSetterCXXAssignment());
 917   Code = serialization::DECL_OBJC_PROPERTY_IMPL;
 918 }
 919
 920 void ASTDeclWriter::VisitFieldDecl(FieldDecl *D) {
 921   VisitDeclaratorDecl(D);
 922   Record.push_back(D->isMutable());
 923
 924   FieldDecl::InitStorageKind ISK = D->InitStorage.getInt();
 925   Record.push_back(ISK);
 926   if (ISK == FieldDecl::ISK_CapturedVLAType)
 927     Record.AddTypeRef(QualType(D->getCapturedVLAType(), 0));
 928   else if (ISK)
 929     Record.AddStmt(D->getInClassInitializer());
 930
 931   Record.AddStmt(D->getBitWidth());
 932
 933   if (!D->getDeclName())
 934     Record.AddDeclRef(Context.getInstantiatedFromUnnamedFieldDecl(D));
 935
 936   if (D->getDeclContext() == D->getLexicalDeclContext() &&
 937       !D->hasAttrs() &&
 938       !D->isImplicit() &&
 939       !D->isUsed(false) &&
 940       !D->isInvalidDecl() &&
 941       !D->isReferenced() &&
 942       !D->isTopLevelDeclInObjCContainer() &&
 943       !D->isModulePrivate() &&
 944       !D->getBitWidth() &&
 945       !D->hasInClassInitializer() &&
 946       !D->hasCapturedVLAType() &&
 947       !D->hasExtInfo() &&
 948       !ObjCIvarDecl::classofKind(D->getKind()) &&
 949       !ObjCAtDefsFieldDecl::classofKind(D->getKind()) &&
 950       D->getDeclName())
 951     AbbrevToUse = Writer.getDeclFieldAbbrev();
 952
 953   Code = serialization::DECL_FIELD;
 954 }
 955
 956 void ASTDeclWriter::VisitMSPropertyDecl(MSPropertyDecl *D) {
 957   VisitDeclaratorDecl(D);
 958   Record.AddIdentifierRef(D->getGetterId());
 959   Record.AddIdentifierRef(D->getSetterId());
 960   Code = serialization::DECL_MS_PROPERTY;
 961 }
 962
 963 void ASTDeclWriter::VisitMSGuidDecl(MSGuidDecl *D) {
 964   VisitValueDecl(D);
 965   MSGuidDecl::Parts Parts = D->getParts();
 966   Record.push_back(Parts.Part1);
 967   Record.push_back(Parts.Part2);
 968   Record.push_back(Parts.Part3);
 969   Record.append(std::begin(Parts.Part4And5), std::end(Parts.Part4And5));
 970   Code = serialization::DECL_MS_GUID;
 971 }
 972
 973 void ASTDeclWriter::VisitUnnamedGlobalConstantDecl(
 974     UnnamedGlobalConstantDecl *D) {
 975   VisitValueDecl(D);
 976   Record.AddAPValue(D->getValue());
 977   Code = serialization::DECL_UNNAMED_GLOBAL_CONSTANT;
 978 }
 979
 980 void ASTDeclWriter::VisitTemplateParamObjectDecl(TemplateParamObjectDecl *D) {
 981   VisitValueDecl(D);
 982   Record.AddAPValue(D->getValue());
 983   Code = serialization::DECL_TEMPLATE_PARAM_OBJECT;
 984 }
 985
 986 void ASTDeclWriter::VisitIndirectFieldDecl(IndirectFieldDecl *D) {
 987   VisitValueDecl(D);
 988   Record.push_back(D->getChainingSize());
 989
 990   for (const auto *P : D->chain())
 991     Record.AddDeclRef(P);
 992   Code = serialization::DECL_INDIRECTFIELD;
 993 }
 994
 995 void ASTDeclWriter::VisitVarDecl(VarDecl *D) {
 996   VisitRedeclarable(D);
 997   VisitDeclaratorDecl(D);
 998   Record.push_back(D->getStorageClass());
 999   Record.push_back(D->getTSCSpec());
1000   Record.push_back(D->getInitStyle());
1001   Record.push_back(D->isARCPseudoStrong());
1002   if (!isa<ParmVarDecl>(D)) {
1003     Record.push_back(D->isThisDeclarationADemotedDefinition());
1004     Record.push_back(D->isExceptionVariable());
1005     Record.push_back(D->isNRVOVariable());
1006     Record.push_back(D->isCXXForRangeDecl());
1007     Record.push_back(D->isObjCForDecl());
1008     Record.push_back(D->isInline());
1009     Record.push_back(D->isInlineSpecified());
1010     Record.push_back(D->isConstexpr());
1011     Record.push_back(D->isInitCapture());
1012     Record.push_back(D->isPreviousDeclInSameBlockScope());
1013     if (const auto *IPD = dyn_cast<ImplicitParamDecl>(D))
1014       Record.push_back(static_cast<unsigned>(IPD->getParameterKind()));
1015     else
1016       Record.push_back(0);
1017     Record.push_back(D->isEscapingByref());
1018   }
1019   Record.push_back(D->getLinkageInternal());
1020
1021   Record.AddVarDeclInit(D);
1022
1023   if (D->hasAttr<BlocksAttr>() && D->getType()->getAsCXXRecordDecl()) {
1024     BlockVarCopyInit Init = Writer.Context->getBlockVarCopyInit(D);
1025     Record.AddStmt(Init.getCopyExpr());
1026     if (Init.getCopyExpr())
1027       Record.push_back(Init.canThrow());
1028   }
1029
1030   if (D->getStorageDuration() == SD_Static) {
1031     bool ModulesCodegen = false;
1032     if (Writer.WritingModule &&
1033         !D->getDescribedVarTemplate() && !D->getMemberSpecializationInfo() &&
1034         !isa<VarTemplateSpecializationDecl>(D)) {
1035       // When building a C++20 module interface unit or a partition unit, a
1036       // strong definition in the module interface is provided by the
1037       // compilation of that unit, not by its users. (Inline variables are still
1038       // emitted in module users.)
1039       ModulesCodegen =
1040           (Writer.WritingModule->isInterfaceOrPartition() ||
1041            (D->hasAttr<DLLExportAttr>() &&
1042             Writer.Context->getLangOpts().BuildingPCHWithObjectFile)) &&
1043           Writer.Context->GetGVALinkageForVariable(D) == GVA_StrongExternal;
1044     }
1045     Record.push_back(ModulesCodegen);
1046     if (ModulesCodegen)
1047       Writer.ModularCodegenDecls.push_back(Writer.GetDeclRef(D));
1048   }
1049
1050   enum {
1051     VarNotTemplate = 0, VarTemplate, StaticDataMemberSpecialization
1052   };
1053   if (VarTemplateDecl *TemplD = D->getDescribedVarTemplate()) {
1054     Record.push_back(VarTemplate);
1055     Record.AddDeclRef(TemplD);
1056   } else if (MemberSpecializationInfo *SpecInfo
1057                = D->getMemberSpecializationInfo()) {
1058     Record.push_back(StaticDataMemberSpecialization);
1059     Record.AddDeclRef(SpecInfo->getInstantiatedFrom());
1060     Record.push_back(SpecInfo->getTemplateSpecializationKind());
1061     Record.AddSourceLocation(SpecInfo->getPointOfInstantiation());
1062   } else {
1063     Record.push_back(VarNotTemplate);
1064   }
1065
1066   if (D->getDeclContext() == D->getLexicalDeclContext() &&
1067       !D->hasAttrs() &&
1068       !D->isImplicit() &&
1069       !D->isUsed(false) &&
1070       !D->isInvalidDecl() &&
1071       !D->isReferenced() &&
1072       !D->isTopLevelDeclInObjCContainer() &&
1073       D->getAccess() == AS_none &&
1074       !D->isModulePrivate() &&
1075       !needsAnonymousDeclarationNumber(D) &&
1076       D->getDeclName().getNameKind() == DeclarationName::Identifier &&
1077       !D->hasExtInfo() &&
1078       D->getFirstDecl() == D->getMostRecentDecl() &&
1079       D->getKind() == Decl::Var &&
1080       !D->isInline() &&
1081       !D->isConstexpr() &&
1082       !D->isInitCapture() &&
1083       !D->isPreviousDeclInSameBlockScope() &&
1084       !(D->hasAttr<BlocksAttr>() && D->getType()->getAsCXXRecordDecl()) &&
1085       !D->isEscapingByref() &&
1086       D->getStorageDuration() != SD_Static &&
1087       !D->getMemberSpecializationInfo())
1088     AbbrevToUse = Writer.getDeclVarAbbrev();
1089
1090   Code = serialization::DECL_VAR;
1091 }
1092
1093 void ASTDeclWriter::VisitImplicitParamDecl(ImplicitParamDecl *D) {
1094   VisitVarDecl(D);
1095   Code = serialization::DECL_IMPLICIT_PARAM;
1096 }
1097
1098 void ASTDeclWriter::VisitParmVarDecl(ParmVarDecl *D) {
1099   VisitVarDecl(D);
1100   Record.push_back(D->isObjCMethodParameter());
1101   Record.push_back(D->getFunctionScopeDepth());
1102   Record.push_back(D->getFunctionScopeIndex());
1103   Record.push_back(D->getObjCDeclQualifier()); // FIXME: stable encoding
1104   Record.push_back(D->isKNRPromoted());
1105   Record.push_back(D->hasInheritedDefaultArg());
1106   Record.push_back(D->hasUninstantiatedDefaultArg());
1107   if (D->hasUninstantiatedDefaultArg())
1108     Record.AddStmt(D->getUninstantiatedDefaultArg());
1109   Code = serialization::DECL_PARM_VAR;
1110
1111   // If the assumptions about the DECL_PARM_VAR abbrev are true, use it.  Here
1112   // we dynamically check for the properties that we optimize for, but don't
1113   // know are true of all PARM_VAR_DECLs.
1114   if (D->getDeclContext() == D->getLexicalDeclContext() &&
1115       !D->hasAttrs() &&
1116       !D->hasExtInfo() &&
1117       !D->isImplicit() &&
1118       !D->isUsed(false) &&
1119       !D->isInvalidDecl() &&
1120       !D->isReferenced() &&
1121       D->getAccess() == AS_none &&
1122       !D->isModulePrivate() &&
1123       D->getStorageClass() == 0 &&
1124       D->getInitStyle() == VarDecl::CInit && // Can params have anything else?
1125       D->getFunctionScopeDepth() == 0 &&
1126       D->getObjCDeclQualifier() == 0 &&
1127       !D->isKNRPromoted() &&
1128       !D->hasInheritedDefaultArg() &&
1129       D->getInit() == nullptr &&
1130       !D->hasUninstantiatedDefaultArg())  // No default expr.
1131     AbbrevToUse = Writer.getDeclParmVarAbbrev();
1132
1133   // Check things we know are true of *every* PARM_VAR_DECL, which is more than
1134   // just us assuming it.
1135   assert(!D->getTSCSpec() && "PARM_VAR_DECL can't use TLS");
1136   assert(!D->isThisDeclarationADemotedDefinition()
1137          && "PARM_VAR_DECL can't be demoted definition.");
1138   assert(D->getAccess() == AS_none && "PARM_VAR_DECL can't be public/private");
1139   assert(!D->isExceptionVariable() && "PARM_VAR_DECL can't be exception var");
1140   assert(D->getPreviousDecl() == nullptr && "PARM_VAR_DECL can't be redecl");
1141   assert(!D->isStaticDataMember() &&
1142          "PARM_VAR_DECL can't be static data member");
1143 }
1144
1145 void ASTDeclWriter::VisitDecompositionDecl(DecompositionDecl *D) {
1146   // Record the number of bindings first to simplify deserialization.
1147   Record.push_back(D->bindings().size());
1148
1149   VisitVarDecl(D);
1150   for (auto *B : D->bindings())
1151     Record.AddDeclRef(B);
1152   Code = serialization::DECL_DECOMPOSITION;
1153 }
1154
1155 void ASTDeclWriter::VisitBindingDecl(BindingDecl *D) {
1156   VisitValueDecl(D);
1157   Record.AddStmt(D->getBinding());
1158   Code = serialization::DECL_BINDING;
1159 }
1160
1161 void ASTDeclWriter::VisitFileScopeAsmDecl(FileScopeAsmDecl *D) {
1162   VisitDecl(D);
1163   Record.AddStmt(D->getAsmString());
1164   Record.AddSourceLocation(D->getRParenLoc());
1165   Code = serialization::DECL_FILE_SCOPE_ASM;
1166 }
1167
1168 void ASTDeclWriter::VisitEmptyDecl(EmptyDecl *D) {
1169   VisitDecl(D);
1170   Code = serialization::DECL_EMPTY;
1171 }
1172
1173 void ASTDeclWriter::VisitLifetimeExtendedTemporaryDecl(
1174     LifetimeExtendedTemporaryDecl *D) {
1175   VisitDecl(D);
1176   Record.AddDeclRef(D->getExtendingDecl());
1177   Record.AddStmt(D->getTemporaryExpr());
1178   Record.push_back(static_cast<bool>(D->getValue()));
1179   if (D->getValue())
1180     Record.AddAPValue(*D->getValue());
1181   Record.push_back(D->getManglingNumber());
1182   Code = serialization::DECL_LIFETIME_EXTENDED_TEMPORARY;
1183 }
1184 void ASTDeclWriter::VisitBlockDecl(BlockDecl *D) {
1185   VisitDecl(D);
1186   Record.AddStmt(D->getBody());
1187   Record.AddTypeSourceInfo(D->getSignatureAsWritten());
1188   Record.push_back(D->param_size());
1189   for (ParmVarDecl *P : D->parameters())
1190     Record.AddDeclRef(P);
1191   Record.push_back(D->isVariadic());
1192   Record.push_back(D->blockMissingReturnType());
1193   Record.push_back(D->isConversionFromLambda());
1194   Record.push_back(D->doesNotEscape());
1195   Record.push_back(D->canAvoidCopyToHeap());
1196   Record.push_back(D->capturesCXXThis());
1197   Record.push_back(D->getNumCaptures());
1198   for (const auto &capture : D->captures()) {
1199     Record.AddDeclRef(capture.getVariable());
1200
1201     unsigned flags = 0;
1202     if (capture.isByRef()) flags |= 1;
1203     if (capture.isNested()) flags |= 2;
1204     if (capture.hasCopyExpr()) flags |= 4;
1205     Record.push_back(flags);
1206
1207     if (capture.hasCopyExpr()) Record.AddStmt(capture.getCopyExpr());
1208   }
1209
1210   Code = serialization::DECL_BLOCK;
1211 }
1212
1213 void ASTDeclWriter::VisitCapturedDecl(CapturedDecl *CD) {
1214   Record.push_back(CD->getNumParams());
1215   VisitDecl(CD);
1216   Record.push_back(CD->getContextParamPosition());
1217   Record.push_back(CD->isNothrow() ? 1 : 0);
1218   // Body is stored by VisitCapturedStmt.
1219   for (unsigned I = 0; I < CD->getNumParams(); ++I)
1220     Record.AddDeclRef(CD->getParam(I));
1221   Code = serialization::DECL_CAPTURED;
1222 }
1223
1224 void ASTDeclWriter::VisitLinkageSpecDecl(LinkageSpecDecl *D) {
1225   VisitDecl(D);
1226   Record.push_back(D->getLanguage());
1227   Record.AddSourceLocation(D->getExternLoc());
1228   Record.AddSourceLocation(D->getRBraceLoc());
1229   Code = serialization::DECL_LINKAGE_SPEC;
1230 }
1231
1232 void ASTDeclWriter::VisitExportDecl(ExportDecl *D) {
1233   VisitDecl(D);
1234   Record.AddSourceLocation(D->getRBraceLoc());
1235   Code = serialization::DECL_EXPORT;
1236 }
1237
1238 void ASTDeclWriter::VisitLabelDecl(LabelDecl *D) {
1239   VisitNamedDecl(D);
1240   Record.AddSourceLocation(D->getBeginLoc());
1241   Code = serialization::DECL_LABEL;
1242 }
1243
1244
1245 void ASTDeclWriter::VisitNamespaceDecl(NamespaceDecl *D) {
1246   VisitRedeclarable(D);
1247   VisitNamedDecl(D);
1248   Record.push_back(D->isInline());
1249   Record.AddSourceLocation(D->getBeginLoc());
1250   Record.AddSourceLocation(D->getRBraceLoc());
1251
1252   if (D->isOriginalNamespace())
1253     Record.AddDeclRef(D->getAnonymousNamespace());
1254   Code = serialization::DECL_NAMESPACE;
1255
1256   if (Writer.hasChain() && D->isAnonymousNamespace() &&
1257       D == D->getMostRecentDecl()) {
1258     // This is a most recent reopening of the anonymous namespace. If its parent
1259     // is in a previous PCH (or is the TU), mark that parent for update, because
1260     // the original namespace always points to the latest re-opening of its
1261     // anonymous namespace.
1262     Decl *Parent = cast<Decl>(
1263         D->getParent()->getRedeclContext()->getPrimaryContext());
1264     if (Parent->isFromASTFile() || isa<TranslationUnitDecl>(Parent)) {
1265       Writer.DeclUpdates[Parent].push_back(
1266           ASTWriter::DeclUpdate(UPD_CXX_ADDED_ANONYMOUS_NAMESPACE, D));
1267     }
1268   }
1269 }
1270
1271 void ASTDeclWriter::VisitNamespaceAliasDecl(NamespaceAliasDecl *D) {
1272   VisitRedeclarable(D);
1273   VisitNamedDecl(D);
1274   Record.AddSourceLocation(D->getNamespaceLoc());
1275   Record.AddSourceLocation(D->getTargetNameLoc());
1276   Record.AddNestedNameSpecifierLoc(D->getQualifierLoc());
1277   Record.AddDeclRef(D->getNamespace());
1278   Code = serialization::DECL_NAMESPACE_ALIAS;
1279 }
1280
1281 void ASTDeclWriter::VisitUsingDecl(UsingDecl *D) {
1282   VisitNamedDecl(D);
1283   Record.AddSourceLocation(D->getUsingLoc());
1284   Record.AddNestedNameSpecifierLoc(D->getQualifierLoc());
1285   Record.AddDeclarationNameLoc(D->DNLoc, D->getDeclName());
1286   Record.AddDeclRef(D->FirstUsingShadow.getPointer());
1287   Record.push_back(D->hasTypename());
1288   Record.AddDeclRef(Context.getInstantiatedFromUsingDecl(D));
1289   Code = serialization::DECL_USING;
1290 }
1291
1292 void ASTDeclWriter::VisitUsingEnumDecl(UsingEnumDecl *D) {
1293   VisitNamedDecl(D);
1294   Record.AddSourceLocation(D->getUsingLoc());
1295   Record.AddSourceLocation(D->getEnumLoc());
1296   Record.AddDeclRef(D->getEnumDecl());
1297   Record.AddDeclRef(D->FirstUsingShadow.getPointer());
1298   Record.AddDeclRef(Context.getInstantiatedFromUsingEnumDecl(D));
1299   Code = serialization::DECL_USING_ENUM;
1300 }
1301
1302 void ASTDeclWriter::VisitUsingPackDecl(UsingPackDecl *D) {
1303   Record.push_back(D->NumExpansions);
1304   VisitNamedDecl(D);
1305   Record.AddDeclRef(D->getInstantiatedFromUsingDecl());
1306   for (auto *E : D->expansions())
1307     Record.AddDeclRef(E);
1308   Code = serialization::DECL_USING_PACK;
1309 }
1310
1311 void ASTDeclWriter::VisitUsingShadowDecl(UsingShadowDecl *D) {
1312   VisitRedeclarable(D);
1313   VisitNamedDecl(D);
1314   Record.AddDeclRef(D->getTargetDecl());
1315   Record.push_back(D->getIdentifierNamespace());
1316   Record.AddDeclRef(D->UsingOrNextShadow);
1317   Record.AddDeclRef(Context.getInstantiatedFromUsingShadowDecl(D));
1318   Code = serialization::DECL_USING_SHADOW;
1319 }
1320
1321 void ASTDeclWriter::VisitConstructorUsingShadowDecl(
1322     ConstructorUsingShadowDecl *D) {
1323   VisitUsingShadowDecl(D);
1324   Record.AddDeclRef(D->NominatedBaseClassShadowDecl);
1325   Record.AddDeclRef(D->ConstructedBaseClassShadowDecl);
1326   Record.push_back(D->IsVirtual);
1327   Code = serialization::DECL_CONSTRUCTOR_USING_SHADOW;
1328 }
1329
1330 void ASTDeclWriter::VisitUsingDirectiveDecl(UsingDirectiveDecl *D) {
1331   VisitNamedDecl(D);
1332   Record.AddSourceLocation(D->getUsingLoc());
1333   Record.AddSourceLocation(D->getNamespaceKeyLocation());
1334   Record.AddNestedNameSpecifierLoc(D->getQualifierLoc());
1335   Record.AddDeclRef(D->getNominatedNamespace());
1336   Record.AddDeclRef(dyn_cast<Decl>(D->getCommonAncestor()));
1337   Code = serialization::DECL_USING_DIRECTIVE;
1338 }
1339
1340 void ASTDeclWriter::VisitUnresolvedUsingValueDecl(UnresolvedUsingValueDecl *D) {
1341   VisitValueDecl(D);
1342   Record.AddSourceLocation(D->getUsingLoc());
1343   Record.AddNestedNameSpecifierLoc(D->getQualifierLoc());
1344   Record.AddDeclarationNameLoc(D->DNLoc, D->getDeclName());
1345   Record.AddSourceLocation(D->getEllipsisLoc());
1346   Code = serialization::DECL_UNRESOLVED_USING_VALUE;
1347 }
1348
1349 void ASTDeclWriter::VisitUnresolvedUsingTypenameDecl(
1350                                                UnresolvedUsingTypenameDecl *D) {
1351   VisitTypeDecl(D);
1352   Record.AddSourceLocation(D->getTypenameLoc());
1353   Record.AddNestedNameSpecifierLoc(D->getQualifierLoc());
1354   Record.AddSourceLocation(D->getEllipsisLoc());
1355   Code = serialization::DECL_UNRESOLVED_USING_TYPENAME;
1356 }
1357
1358 void ASTDeclWriter::VisitUnresolvedUsingIfExistsDecl(
1359     UnresolvedUsingIfExistsDecl *D) {
1360   VisitNamedDecl(D);
1361   Code = serialization::DECL_UNRESOLVED_USING_IF_EXISTS;
1362 }
1363
1364 void ASTDeclWriter::VisitCXXRecordDecl(CXXRecordDecl *D) {
1365   VisitRecordDecl(D);
1366
1367   enum {
1368     CXXRecNotTemplate = 0, CXXRecTemplate, CXXRecMemberSpecialization
1369   };
1370   if (ClassTemplateDecl *TemplD = D->getDescribedClassTemplate()) {
1371     Record.push_back(CXXRecTemplate);
1372     Record.AddDeclRef(TemplD);
1373   } else if (MemberSpecializationInfo *MSInfo
1374                = D->getMemberSpecializationInfo()) {
1375     Record.push_back(CXXRecMemberSpecialization);
1376     Record.AddDeclRef(MSInfo->getInstantiatedFrom());
1377     Record.push_back(MSInfo->getTemplateSpecializationKind());
1378     Record.AddSourceLocation(MSInfo->getPointOfInstantiation());
1379   } else {
1380     Record.push_back(CXXRecNotTemplate);
1381   }
1382
1383   Record.push_back(D->isThisDeclarationADefinition());
1384   if (D->isThisDeclarationADefinition())
1385     Record.AddCXXDefinitionData(D);
1386
1387   // Store (what we currently believe to be) the key function to avoid
1388   // deserializing every method so we can compute it.
1389   if (D->isCompleteDefinition())
1390     Record.AddDeclRef(Context.getCurrentKeyFunction(D));
1391
1392   Code = serialization::DECL_CXX_RECORD;
1393 }
1394
1395 void ASTDeclWriter::VisitCXXMethodDecl(CXXMethodDecl *D) {
1396   VisitFunctionDecl(D);
1397   if (D->isCanonicalDecl()) {
1398     Record.push_back(D->size_overridden_methods());
1399     for (const CXXMethodDecl *MD : D->overridden_methods())
1400       Record.AddDeclRef(MD);
1401   } else {
1402     // We only need to record overridden methods once for the canonical decl.
1403     Record.push_back(0);
1404   }
1405
1406   if (D->getDeclContext() == D->getLexicalDeclContext() &&
1407       D->getFirstDecl() == D->getMostRecentDecl() &&
1408       !D->isInvalidDecl() &&
1409       !D->hasAttrs() &&
1410       !D->isTopLevelDeclInObjCContainer() &&
1411       D->getDeclName().getNameKind() == DeclarationName::Identifier &&
1412       !D->hasExtInfo() &&
1413       !D->hasInheritedPrototype() &&
1414       D->hasWrittenPrototype())
1415     AbbrevToUse = Writer.getDeclCXXMethodAbbrev();
1416
1417   Code = serialization::DECL_CXX_METHOD;
1418 }
1419
1420 void ASTDeclWriter::VisitCXXConstructorDecl(CXXConstructorDecl *D) {
1421   Record.push_back(D->getTrailingAllocKind());
1422   addExplicitSpecifier(D->getExplicitSpecifier(), Record);
1423   if (auto Inherited = D->getInheritedConstructor()) {
1424     Record.AddDeclRef(Inherited.getShadowDecl());
1425     Record.AddDeclRef(Inherited.getConstructor());
1426   }
1427
1428   VisitCXXMethodDecl(D);
1429   Code = serialization::DECL_CXX_CONSTRUCTOR;
1430 }
1431
1432 void ASTDeclWriter::VisitCXXDestructorDecl(CXXDestructorDecl *D) {
1433   VisitCXXMethodDecl(D);
1434
1435   Record.AddDeclRef(D->getOperatorDelete());
1436   if (D->getOperatorDelete())
1437     Record.AddStmt(D->getOperatorDeleteThisArg());
1438
1439   Code = serialization::DECL_CXX_DESTRUCTOR;
1440 }
1441
1442 void ASTDeclWriter::VisitCXXConversionDecl(CXXConversionDecl *D) {
1443   addExplicitSpecifier(D->getExplicitSpecifier(), Record);
1444   VisitCXXMethodDecl(D);
1445   Code = serialization::DECL_CXX_CONVERSION;
1446 }
1447
1448 void ASTDeclWriter::VisitImportDecl(ImportDecl *D) {
1449   VisitDecl(D);
1450   Record.push_back(Writer.getSubmoduleID(D->getImportedModule()));
1451   ArrayRef<SourceLocation> IdentifierLocs = D->getIdentifierLocs();
1452   Record.push_back(!IdentifierLocs.empty());
1453   if (IdentifierLocs.empty()) {
1454     Record.AddSourceLocation(D->getEndLoc());
1455     Record.push_back(1);
1456   } else {
1457     for (unsigned I = 0, N = IdentifierLocs.size(); I != N; ++I)
1458       Record.AddSourceLocation(IdentifierLocs[I]);
1459     Record.push_back(IdentifierLocs.size());
1460   }
1461   // Note: the number of source locations must always be the last element in
1462   // the record.
1463   Code = serialization::DECL_IMPORT;
1464 }
1465
1466 void ASTDeclWriter::VisitAccessSpecDecl(AccessSpecDecl *D) {
1467   VisitDecl(D);
1468   Record.AddSourceLocation(D->getColonLoc());
1469   Code = serialization::DECL_ACCESS_SPEC;
1470 }
1471
1472 void ASTDeclWriter::VisitFriendDecl(FriendDecl *D) {
1473   // Record the number of friend type template parameter lists here
1474   // so as to simplify memory allocation during deserialization.
1475   Record.push_back(D->NumTPLists);
1476   VisitDecl(D);
1477   bool hasFriendDecl = D->Friend.is<NamedDecl*>();
1478   Record.push_back(hasFriendDecl);
1479   if (hasFriendDecl)
1480     Record.AddDeclRef(D->getFriendDecl());
1481   else
1482     Record.AddTypeSourceInfo(D->getFriendType());
1483   for (unsigned i = 0; i < D->NumTPLists; ++i)
1484     Record.AddTemplateParameterList(D->getFriendTypeTemplateParameterList(i));
1485   Record.AddDeclRef(D->getNextFriend());
1486   Record.push_back(D->UnsupportedFriend);
1487   Record.AddSourceLocation(D->FriendLoc);
1488   Code = serialization::DECL_FRIEND;
1489 }
1490
1491 void ASTDeclWriter::VisitFriendTemplateDecl(FriendTemplateDecl *D) {
1492   VisitDecl(D);
1493   Record.push_back(D->getNumTemplateParameters());
1494   for (unsigned i = 0, e = D->getNumTemplateParameters(); i != e; ++i)
1495     Record.AddTemplateParameterList(D->getTemplateParameterList(i));
1496   Record.push_back(D->getFriendDecl() != nullptr);
1497   if (D->getFriendDecl())
1498     Record.AddDeclRef(D->getFriendDecl());
1499   else
1500     Record.AddTypeSourceInfo(D->getFriendType());
1501   Record.AddSourceLocation(D->getFriendLoc());
1502   Code = serialization::DECL_FRIEND_TEMPLATE;
1503 }
1504
1505 void ASTDeclWriter::VisitTemplateDecl(TemplateDecl *D) {
1506   VisitNamedDecl(D);
1507
1508   Record.AddDeclRef(D->getTemplatedDecl());
1509   Record.AddTemplateParameterList(D->getTemplateParameters());
1510 }
1511
1512 void ASTDeclWriter::VisitConceptDecl(ConceptDecl *D) {
1513   VisitTemplateDecl(D);
1514   Record.AddStmt(D->getConstraintExpr());
1515   Code = serialization::DECL_CONCEPT;
1516 }
1517
1518 void ASTDeclWriter::VisitRequiresExprBodyDecl(RequiresExprBodyDecl *D) {
1519   Code = serialization::DECL_REQUIRES_EXPR_BODY;
1520 }
1521
1522 void ASTDeclWriter::VisitRedeclarableTemplateDecl(RedeclarableTemplateDecl *D) {
1523   VisitRedeclarable(D);
1524
1525   // Emit data to initialize CommonOrPrev before VisitTemplateDecl so that
1526   // getCommonPtr() can be used while this is still initializing.
1527   if (D->isFirstDecl()) {
1528     // This declaration owns the 'common' pointer, so serialize that data now.
1529     Record.AddDeclRef(D->getInstantiatedFromMemberTemplate());
1530     if (D->getInstantiatedFromMemberTemplate())
1531       Record.push_back(D->isMemberSpecialization());
1532   }
1533
1534   VisitTemplateDecl(D);
1535   Record.push_back(D->getIdentifierNamespace());
1536 }
1537
1538 void ASTDeclWriter::VisitClassTemplateDecl(ClassTemplateDecl *D) {
1539   VisitRedeclarableTemplateDecl(D);
1540
1541   if (D->isFirstDecl())
1542     AddTemplateSpecializations(D);
1543   Code = serialization::DECL_CLASS_TEMPLATE;
1544 }
1545
1546 void ASTDeclWriter::VisitClassTemplateSpecializationDecl(
1547                                            ClassTemplateSpecializationDecl *D) {
1548   RegisterTemplateSpecialization(D->getSpecializedTemplate(), D);
1549
1550   VisitCXXRecordDecl(D);
1551
1552   llvm::PointerUnion<ClassTemplateDecl *,
1553                      ClassTemplatePartialSpecializationDecl *> InstFrom
1554     = D->getSpecializedTemplateOrPartial();
1555   if (Decl *InstFromD = InstFrom.dyn_cast<ClassTemplateDecl *>()) {
1556     Record.AddDeclRef(InstFromD);
1557   } else {
1558     Record.AddDeclRef(InstFrom.get<ClassTemplatePartialSpecializationDecl *>());
1559     Record.AddTemplateArgumentList(&D->getTemplateInstantiationArgs());
1560   }
1561
1562   Record.AddTemplateArgumentList(&D->getTemplateArgs());
1563   Record.AddSourceLocation(D->getPointOfInstantiation());
1564   Record.push_back(D->getSpecializationKind());
1565   Record.push_back(D->isCanonicalDecl());
1566
1567   if (D->isCanonicalDecl()) {
1568     // When reading, we'll add it to the folding set of the following template.
1569     Record.AddDeclRef(D->getSpecializedTemplate()->getCanonicalDecl());
1570   }
1571
1572   // Explicit info.
1573   Record.AddTypeSourceInfo(D->getTypeAsWritten());
1574   if (D->getTypeAsWritten()) {
1575     Record.AddSourceLocation(D->getExternLoc());
1576     Record.AddSourceLocation(D->getTemplateKeywordLoc());
1577   }
1578
1579   Code = serialization::DECL_CLASS_TEMPLATE_SPECIALIZATION;
1580 }
1581
1582 void ASTDeclWriter::VisitClassTemplatePartialSpecializationDecl(
1583                                     ClassTemplatePartialSpecializationDecl *D) {
1584   Record.AddTemplateParameterList(D->getTemplateParameters());
1585   Record.AddASTTemplateArgumentListInfo(D->getTemplateArgsAsWritten());
1586
1587   VisitClassTemplateSpecializationDecl(D);
1588
1589   // These are read/set from/to the first declaration.
1590   if (D->getPreviousDecl() == nullptr) {
1591     Record.AddDeclRef(D->getInstantiatedFromMember());
1592     Record.push_back(D->isMemberSpecialization());
1593   }
1594
1595   Code = serialization::DECL_CLASS_TEMPLATE_PARTIAL_SPECIALIZATION;
1596 }
1597
1598 void ASTDeclWriter::VisitVarTemplateDecl(VarTemplateDecl *D) {
1599   VisitRedeclarableTemplateDecl(D);
1600
1601   if (D->isFirstDecl())
1602     AddTemplateSpecializations(D);
1603   Code = serialization::DECL_VAR_TEMPLATE;
1604 }
1605
1606 void ASTDeclWriter::VisitVarTemplateSpecializationDecl(
1607     VarTemplateSpecializationDecl *D) {
1608   RegisterTemplateSpecialization(D->getSpecializedTemplate(), D);
1609
1610   VisitVarDecl(D);
1611
1612   llvm::PointerUnion<VarTemplateDecl *, VarTemplatePartialSpecializationDecl *>
1613   InstFrom = D->getSpecializedTemplateOrPartial();
1614   if (Decl *InstFromD = InstFrom.dyn_cast<VarTemplateDecl *>()) {
1615     Record.AddDeclRef(InstFromD);
1616   } else {
1617     Record.AddDeclRef(InstFrom.get<VarTemplatePartialSpecializationDecl *>());
1618     Record.AddTemplateArgumentList(&D->getTemplateInstantiationArgs());
1619   }
1620
1621   // Explicit info.
1622   Record.AddTypeSourceInfo(D->getTypeAsWritten());
1623   if (D->getTypeAsWritten()) {
1624     Record.AddSourceLocation(D->getExternLoc());
1625     Record.AddSourceLocation(D->getTemplateKeywordLoc());
1626   }
1627
1628   Record.AddTemplateArgumentList(&D->getTemplateArgs());
1629   Record.AddSourceLocation(D->getPointOfInstantiation());
1630   Record.push_back(D->getSpecializationKind());
1631   Record.push_back(D->IsCompleteDefinition);
1632   Record.push_back(D->isCanonicalDecl());
1633
1634   if (D->isCanonicalDecl()) {
1635     // When reading, we'll add it to the folding set of the following template.
1636     Record.AddDeclRef(D->getSpecializedTemplate()->getCanonicalDecl());
1637   }
1638
1639   Code = serialization::DECL_VAR_TEMPLATE_SPECIALIZATION;
1640 }
1641
1642 void ASTDeclWriter::VisitVarTemplatePartialSpecializationDecl(
1643     VarTemplatePartialSpecializationDecl *D) {
1644   Record.AddTemplateParameterList(D->getTemplateParameters());
1645   Record.AddASTTemplateArgumentListInfo(D->getTemplateArgsAsWritten());
1646
1647   VisitVarTemplateSpecializationDecl(D);
1648
1649   // These are read/set from/to the first declaration.
1650   if (D->getPreviousDecl() == nullptr) {
1651     Record.AddDeclRef(D->getInstantiatedFromMember());
1652     Record.push_back(D->isMemberSpecialization());
1653   }
1654
1655   Code = serialization::DECL_VAR_TEMPLATE_PARTIAL_SPECIALIZATION;
1656 }
1657
1658 void ASTDeclWriter::VisitClassScopeFunctionSpecializationDecl(
1659                                     ClassScopeFunctionSpecializationDecl *D) {
1660   VisitDecl(D);
1661   Record.AddDeclRef(D->getSpecialization());
1662   Record.push_back(D->hasExplicitTemplateArgs());
1663   if (D->hasExplicitTemplateArgs())
1664     Record.AddASTTemplateArgumentListInfo(D->getTemplateArgsAsWritten());
1665   Code = serialization::DECL_CLASS_SCOPE_FUNCTION_SPECIALIZATION;
1666 }
1667
1668
1669 void ASTDeclWriter::VisitFunctionTemplateDecl(FunctionTemplateDecl *D) {
1670   VisitRedeclarableTemplateDecl(D);
1671
1672   if (D->isFirstDecl())
1673     AddTemplateSpecializations(D);
1674   Code = serialization::DECL_FUNCTION_TEMPLATE;
1675 }
1676
1677 void ASTDeclWriter::VisitTemplateTypeParmDecl(TemplateTypeParmDecl *D) {
1678   Record.push_back(D->hasTypeConstraint());
1679   VisitTypeDecl(D);
1680
1681   Record.push_back(D->wasDeclaredWithTypename());
1682
1683   const TypeConstraint *TC = D->getTypeConstraint();
1684   Record.push_back(TC != nullptr);
1685   if (TC) {
1686     Record.AddNestedNameSpecifierLoc(TC->getNestedNameSpecifierLoc());
1687     Record.AddDeclarationNameInfo(TC->getConceptNameInfo());
1688     Record.AddDeclRef(TC->getNamedConcept());
1689     Record.push_back(TC->getTemplateArgsAsWritten() != nullptr);
1690     if (TC->getTemplateArgsAsWritten())
1691       Record.AddASTTemplateArgumentListInfo(TC->getTemplateArgsAsWritten());
1692     Record.AddStmt(TC->getImmediatelyDeclaredConstraint());
1693     Record.push_back(D->isExpandedParameterPack());
1694     if (D->isExpandedParameterPack())
1695       Record.push_back(D->getNumExpansionParameters());
1696   }
1697
1698   bool OwnsDefaultArg = D->hasDefaultArgument() &&
1699                         !D->defaultArgumentWasInherited();
1700   Record.push_back(OwnsDefaultArg);
1701   if (OwnsDefaultArg)
1702     Record.AddTypeSourceInfo(D->getDefaultArgumentInfo());
1703
1704   Code = serialization::DECL_TEMPLATE_TYPE_PARM;
1705 }
1706
1707 void ASTDeclWriter::VisitNonTypeTemplateParmDecl(NonTypeTemplateParmDecl *D) {
1708   // For an expanded parameter pack, record the number of expansion types here
1709   // so that it's easier for deserialization to allocate the right amount of
1710   // memory.
1711   Expr *TypeConstraint = D->getPlaceholderTypeConstraint();
1712   Record.push_back(!!TypeConstraint);
1713   if (D->isExpandedParameterPack())
1714     Record.push_back(D->getNumExpansionTypes());
1715
1716   VisitDeclaratorDecl(D);
1717   // TemplateParmPosition.
1718   Record.push_back(D->getDepth());
1719   Record.push_back(D->getPosition());
1720   if (TypeConstraint)
1721     Record.AddStmt(TypeConstraint);
1722
1723   if (D->isExpandedParameterPack()) {
1724     for (unsigned I = 0, N = D->getNumExpansionTypes(); I != N; ++I) {
1725       Record.AddTypeRef(D->getExpansionType(I));
1726       Record.AddTypeSourceInfo(D->getExpansionTypeSourceInfo(I));
1727     }
1728
1729     Code = serialization::DECL_EXPANDED_NON_TYPE_TEMPLATE_PARM_PACK;
1730   } else {
1731     // Rest of NonTypeTemplateParmDecl.
1732     Record.push_back(D->isParameterPack());
1733     bool OwnsDefaultArg = D->hasDefaultArgument() &&
1734                           !D->defaultArgumentWasInherited();
1735     Record.push_back(OwnsDefaultArg);
1736     if (OwnsDefaultArg)
1737       Record.AddStmt(D->getDefaultArgument());
1738     Code = serialization::DECL_NON_TYPE_TEMPLATE_PARM;
1739   }
1740 }
1741
1742 void ASTDeclWriter::VisitTemplateTemplateParmDecl(TemplateTemplateParmDecl *D) {
1743   // For an expanded parameter pack, record the number of expansion types here
1744   // so that it's easier for deserialization to allocate the right amount of
1745   // memory.
1746   if (D->isExpandedParameterPack())
1747     Record.push_back(D->getNumExpansionTemplateParameters());
1748
1749   VisitTemplateDecl(D);
1750   // TemplateParmPosition.
1751   Record.push_back(D->getDepth());
1752   Record.push_back(D->getPosition());
1753
1754   if (D->isExpandedParameterPack()) {
1755     for (unsigned I = 0, N = D->getNumExpansionTemplateParameters();
1756          I != N; ++I)
1757       Record.AddTemplateParameterList(D->getExpansionTemplateParameters(I));
1758     Code = serialization::DECL_EXPANDED_TEMPLATE_TEMPLATE_PARM_PACK;
1759   } else {
1760     // Rest of TemplateTemplateParmDecl.
1761     Record.push_back(D->isParameterPack());
1762     bool OwnsDefaultArg = D->hasDefaultArgument() &&
1763                           !D->defaultArgumentWasInherited();
1764     Record.push_back(OwnsDefaultArg);
1765     if (OwnsDefaultArg)
1766       Record.AddTemplateArgumentLoc(D->getDefaultArgument());
1767     Code = serialization::DECL_TEMPLATE_TEMPLATE_PARM;
1768   }
1769 }
1770
1771 void ASTDeclWriter::VisitTypeAliasTemplateDecl(TypeAliasTemplateDecl *D) {
1772   VisitRedeclarableTemplateDecl(D);
1773   Code = serialization::DECL_TYPE_ALIAS_TEMPLATE;
1774 }
1775
1776 void ASTDeclWriter::VisitStaticAssertDecl(StaticAssertDecl *D) {
1777   VisitDecl(D);
1778   Record.AddStmt(D->getAssertExpr());
1779   Record.push_back(D->isFailed());
1780   Record.AddStmt(D->getMessage());
1781   Record.AddSourceLocation(D->getRParenLoc());
1782   Code = serialization::DECL_STATIC_ASSERT;
1783 }
1784
1785 /// Emit the DeclContext part of a declaration context decl.
1786 void ASTDeclWriter::VisitDeclContext(DeclContext *DC) {
1787   Record.AddOffset(Writer.WriteDeclContextLexicalBlock(Context, DC));
1788   Record.AddOffset(Writer.WriteDeclContextVisibleBlock(Context, DC));
1789 }
1790
1791 const Decl *ASTWriter::getFirstLocalDecl(const Decl *D) {
1792   assert(IsLocalDecl(D) && "expected a local declaration");
1793
1794   const Decl *Canon = D->getCanonicalDecl();
1795   if (IsLocalDecl(Canon))
1796     return Canon;
1797
1798   const Decl *&CacheEntry = FirstLocalDeclCache[Canon];
1799   if (CacheEntry)
1800     return CacheEntry;
1801
1802   for (const Decl *Redecl = D; Redecl; Redecl = Redecl->getPreviousDecl())
1803     if (IsLocalDecl(Redecl))
1804       D = Redecl;
1805   return CacheEntry = D;
1806 }
1807
1808 template <typename T>
1809 void ASTDeclWriter::VisitRedeclarable(Redeclarable<T> *D) {
1810   T *First = D->getFirstDecl();
1811   T *MostRecent = First->getMostRecentDecl();
1812   T *DAsT = static_cast<T *>(D);
1813   if (MostRecent != First) {
1814     assert(isRedeclarableDeclKind(DAsT->getKind()) &&
1815            "Not considered redeclarable?");
1816
1817     Record.AddDeclRef(First);
1818
1819     // Write out a list of local redeclarations of this declaration if it's the
1820     // first local declaration in the chain.
1821     const Decl *FirstLocal = Writer.getFirstLocalDecl(DAsT);
1822     if (DAsT == FirstLocal) {
1823       // Emit a list of all imported first declarations so that we can be sure
1824       // that all redeclarations visible to this module are before D in the
1825       // redecl chain.
1826       unsigned I = Record.size();
1827       Record.push_back(0);
1828       if (Writer.Chain)
1829         AddFirstDeclFromEachModule(DAsT, /*IncludeLocal*/false);
1830       // This is the number of imported first declarations + 1.
1831       Record[I] = Record.size() - I;
1832
1833       // Collect the set of local redeclarations of this declaration, from
1834       // newest to oldest.
1835       ASTWriter::RecordData LocalRedecls;
1836       ASTRecordWriter LocalRedeclWriter(Record, LocalRedecls);
1837       for (const Decl *Prev = FirstLocal->getMostRecentDecl();
1838            Prev != FirstLocal; Prev = Prev->getPreviousDecl())
1839         if (!Prev->isFromASTFile())
1840           LocalRedeclWriter.AddDeclRef(Prev);
1841
1842       // If we have any redecls, write them now as a separate record preceding
1843       // the declaration itself.
1844       if (LocalRedecls.empty())
1845         Record.push_back(0);
1846       else
1847         Record.AddOffset(LocalRedeclWriter.Emit(LOCAL_REDECLARATIONS));
1848     } else {
1849       Record.push_back(0);
1850       Record.AddDeclRef(FirstLocal);
1851     }
1852
1853     // Make sure that we serialize both the previous and the most-recent
1854     // declarations, which (transitively) ensures that all declarations in the
1855     // chain get serialized.
1856     //
1857     // FIXME: This is not correct; when we reach an imported declaration we
1858     // won't emit its previous declaration.
1859     (void)Writer.GetDeclRef(D->getPreviousDecl());
1860     (void)Writer.GetDeclRef(MostRecent);
1861   } else {
1862     // We use the sentinel value 0 to indicate an only declaration.
1863     Record.push_back(0);
1864   }
1865 }
1866
1867 void ASTDeclWriter::VisitOMPThreadPrivateDecl(OMPThreadPrivateDecl *D) {
1868   Record.writeOMPChildren(D->Data);
1869   VisitDecl(D);
1870   Code = serialization::DECL_OMP_THREADPRIVATE;
1871 }
1872
1873 void ASTDeclWriter::VisitOMPAllocateDecl(OMPAllocateDecl *D) {
1874   Record.writeOMPChildren(D->Data);
1875   VisitDecl(D);
1876   Code = serialization::DECL_OMP_ALLOCATE;
1877 }
1878
1879 void ASTDeclWriter::VisitOMPRequiresDecl(OMPRequiresDecl *D) {
1880   Record.writeOMPChildren(D->Data);
1881   VisitDecl(D);
1882   Code = serialization::DECL_OMP_REQUIRES;
1883 }
1884
1885 void ASTDeclWriter::VisitOMPDeclareReductionDecl(OMPDeclareReductionDecl *D) {
1886   VisitValueDecl(D);
1887   Record.AddSourceLocation(D->getBeginLoc());
1888   Record.AddStmt(D->getCombinerIn());
1889   Record.AddStmt(D->getCombinerOut());
1890   Record.AddStmt(D->getCombiner());
1891   Record.AddStmt(D->getInitOrig());
1892   Record.AddStmt(D->getInitPriv());
1893   Record.AddStmt(D->getInitializer());
1894   Record.push_back(D->getInitializerKind());
1895   Record.AddDeclRef(D->getPrevDeclInScope());
1896   Code = serialization::DECL_OMP_DECLARE_REDUCTION;
1897 }
1898
1899 void ASTDeclWriter::VisitOMPDeclareMapperDecl(OMPDeclareMapperDecl *D) {
1900   Record.writeOMPChildren(D->Data);
1901   VisitValueDecl(D);
1902   Record.AddDeclarationName(D->getVarName());
1903   Record.AddDeclRef(D->getPrevDeclInScope());
1904   Code = serialization::DECL_OMP_DECLARE_MAPPER;
1905 }
1906
1907 void ASTDeclWriter::VisitOMPCapturedExprDecl(OMPCapturedExprDecl *D) {
1908   VisitVarDecl(D);
1909   Code = serialization::DECL_OMP_CAPTUREDEXPR;
1910 }
1911
1912 //===----------------------------------------------------------------------===//
1913 // ASTWriter Implementation
1914 //===----------------------------------------------------------------------===//
1915
1916 void ASTWriter::WriteDeclAbbrevs() {
1917   using namespace llvm;
1918
1919   std::shared_ptr<BitCodeAbbrev> Abv;
1920
1921   // Abbreviation for DECL_FIELD
1922   Abv = std::make_shared<BitCodeAbbrev>();
1923   Abv->Add(BitCodeAbbrevOp(serialization::DECL_FIELD));
1924   // Decl
1925   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclContext
1926   Abv->Add(BitCodeAbbrevOp(0));                       // LexicalDeclContext
1927   Abv->Add(BitCodeAbbrevOp(0));                       // isInvalidDecl
1928   Abv->Add(BitCodeAbbrevOp(0));                       // HasAttrs
1929   Abv->Add(BitCodeAbbrevOp(0));                       // isImplicit
1930   Abv->Add(BitCodeAbbrevOp(0));                       // isUsed
1931   Abv->Add(BitCodeAbbrevOp(0));                       // isReferenced
1932   Abv->Add(BitCodeAbbrevOp(0));                   // TopLevelDeclInObjCContainer
1933   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2));  // AccessSpecifier
1934   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3));  // ModuleOwnershipKind
1935   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // SubmoduleID
1936   // NamedDecl
1937   Abv->Add(BitCodeAbbrevOp(0));                       // NameKind = Identifier
1938   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Name
1939   Abv->Add(BitCodeAbbrevOp(0));                       // AnonDeclNumber
1940   // ValueDecl
1941   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
1942   // DeclaratorDecl
1943   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // InnerStartLoc
1944   Abv->Add(BitCodeAbbrevOp(0));                       // hasExtInfo
1945   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // TSIType
1946   // FieldDecl
1947   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isMutable
1948   Abv->Add(BitCodeAbbrevOp(0));                       // InitStyle
1949   // Type Source Info
1950   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1951   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // TypeLoc
1952   DeclFieldAbbrev = Stream.EmitAbbrev(std::move(Abv));
1953
1954   // Abbreviation for DECL_OBJC_IVAR
1955   Abv = std::make_shared<BitCodeAbbrev>();
1956   Abv->Add(BitCodeAbbrevOp(serialization::DECL_OBJC_IVAR));
1957   // Decl
1958   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclContext
1959   Abv->Add(BitCodeAbbrevOp(0));                       // LexicalDeclContext
1960   Abv->Add(BitCodeAbbrevOp(0));                       // isInvalidDecl
1961   Abv->Add(BitCodeAbbrevOp(0));                       // HasAttrs
1962   Abv->Add(BitCodeAbbrevOp(0));                       // isImplicit
1963   Abv->Add(BitCodeAbbrevOp(0));                       // isUsed
1964   Abv->Add(BitCodeAbbrevOp(0));                       // isReferenced
1965   Abv->Add(BitCodeAbbrevOp(0));                   // TopLevelDeclInObjCContainer
1966   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2));  // AccessSpecifier
1967   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3));  // ModuleOwnershipKind
1968   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // SubmoduleID
1969   // NamedDecl
1970   Abv->Add(BitCodeAbbrevOp(0));                       // NameKind = Identifier
1971   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Name
1972   Abv->Add(BitCodeAbbrevOp(0));                       // AnonDeclNumber
1973   // ValueDecl
1974   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
1975   // DeclaratorDecl
1976   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // InnerStartLoc
1977   Abv->Add(BitCodeAbbrevOp(0));                       // hasExtInfo
1978   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // TSIType
1979   // FieldDecl
1980   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isMutable
1981   Abv->Add(BitCodeAbbrevOp(0));                       // InitStyle
1982   // ObjC Ivar
1983   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // getAccessControl
1984   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // getSynthesize
1985   // Type Source Info
1986   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1987   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // TypeLoc
1988   DeclObjCIvarAbbrev = Stream.EmitAbbrev(std::move(Abv));
1989
1990   // Abbreviation for DECL_ENUM
1991   Abv = std::make_shared<BitCodeAbbrev>();
1992   Abv->Add(BitCodeAbbrevOp(serialization::DECL_ENUM));
1993   // Redeclarable
1994   Abv->Add(BitCodeAbbrevOp(0));                       // No redeclaration
1995   // Decl
1996   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclContext
1997   Abv->Add(BitCodeAbbrevOp(0));                       // LexicalDeclContext
1998   Abv->Add(BitCodeAbbrevOp(0));                       // isInvalidDecl
1999   Abv->Add(BitCodeAbbrevOp(0));                       // HasAttrs
2000   Abv->Add(BitCodeAbbrevOp(0));                       // isImplicit
2001   Abv->Add(BitCodeAbbrevOp(0));                       // isUsed
2002   Abv->Add(BitCodeAbbrevOp(0));                       // isReferenced
2003   Abv->Add(BitCodeAbbrevOp(0));                   // TopLevelDeclInObjCContainer
2004   Abv->Add(BitCodeAbbrevOp(AS_none));                 // C++ AccessSpecifier
2005   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); // ModuleOwnershipKind
2006   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // SubmoduleID
2007   // NamedDecl
2008   Abv->Add(BitCodeAbbrevOp(0));                       // NameKind = Identifier
2009   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Name
2010   Abv->Add(BitCodeAbbrevOp(0));                       // AnonDeclNumber
2011   // TypeDecl
2012   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Source Location
2013   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type Ref
2014   // TagDecl
2015   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // IdentifierNamespace
2016   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // getTagKind
2017   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isCompleteDefinition
2018   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // EmbeddedInDeclarator
2019   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsFreeStanding
2020   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsCompleteDefinitionRequired
2021   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // SourceLocation
2022   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // SourceLocation
2023   Abv->Add(BitCodeAbbrevOp(0));                         // ExtInfoKind
2024   // EnumDecl
2025   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // AddTypeRef
2026   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // IntegerType
2027   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // getPromotionType
2028   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // getNumPositiveBits
2029   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // getNumNegativeBits
2030   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isScoped
2031   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isScopedUsingClassTag
2032   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isFixed
2033   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));// ODRHash
2034   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // InstantiatedMembEnum
2035   // DC
2036   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // LexicalOffset
2037   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // VisibleOffset
2038   DeclEnumAbbrev = Stream.EmitAbbrev(std::move(Abv));
2039
2040   // Abbreviation for DECL_RECORD
2041   Abv = std::make_shared<BitCodeAbbrev>();
2042   Abv->Add(BitCodeAbbrevOp(serialization::DECL_RECORD));
2043   // Redeclarable
2044   Abv->Add(BitCodeAbbrevOp(0));                       // No redeclaration
2045   // Decl
2046   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclContext
2047   Abv->Add(BitCodeAbbrevOp(0));                       // LexicalDeclContext
2048   Abv->Add(BitCodeAbbrevOp(0));                       // isInvalidDecl
2049   Abv->Add(BitCodeAbbrevOp(0));                       // HasAttrs
2050   Abv->Add(BitCodeAbbrevOp(0));                       // isImplicit
2051   Abv->Add(BitCodeAbbrevOp(0));                       // isUsed
2052   Abv->Add(BitCodeAbbrevOp(0));                       // isReferenced
2053   Abv->Add(BitCodeAbbrevOp(0));                   // TopLevelDeclInObjCContainer
2054   Abv->Add(BitCodeAbbrevOp(AS_none));                 // C++ AccessSpecifier
2055   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); // ModuleOwnershipKind
2056   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // SubmoduleID
2057   // NamedDecl
2058   Abv->Add(BitCodeAbbrevOp(0));                       // NameKind = Identifier
2059   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Name
2060   Abv->Add(BitCodeAbbrevOp(0));                       // AnonDeclNumber
2061   // TypeDecl
2062   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Source Location
2063   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type Ref
2064   // TagDecl
2065   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // IdentifierNamespace
2066   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // getTagKind
2067   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isCompleteDefinition
2068   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // EmbeddedInDeclarator
2069   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsFreeStanding
2070   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsCompleteDefinitionRequired
2071   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // SourceLocation
2072   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // SourceLocation
2073   Abv->Add(BitCodeAbbrevOp(0));                         // ExtInfoKind
2074   // RecordDecl
2075   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // FlexibleArrayMember
2076   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // AnonymousStructUnion
2077   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // hasObjectMember
2078   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // hasVolatileMember
2079
2080   // isNonTrivialToPrimitiveDefaultInitialize
2081   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
2082   // isNonTrivialToPrimitiveCopy
2083   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
2084   // isNonTrivialToPrimitiveDestroy
2085   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
2086   // hasNonTrivialToPrimitiveDefaultInitializeCUnion
2087   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
2088   // hasNonTrivialToPrimitiveDestructCUnion
2089   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
2090   // hasNonTrivialToPrimitiveCopyCUnion
2091   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
2092   // isParamDestroyedInCallee
2093   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
2094   // getArgPassingRestrictions
2095   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2));
2096
2097   // DC
2098   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // LexicalOffset
2099   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // VisibleOffset
2100   DeclRecordAbbrev = Stream.EmitAbbrev(std::move(Abv));
2101
2102   // Abbreviation for DECL_PARM_VAR
2103   Abv = std::make_shared<BitCodeAbbrev>();
2104   Abv->Add(BitCodeAbbrevOp(serialization::DECL_PARM_VAR));
2105   // Redeclarable
2106   Abv->Add(BitCodeAbbrevOp(0));                       // No redeclaration
2107   // Decl
2108   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclContext
2109   Abv->Add(BitCodeAbbrevOp(0));                       // LexicalDeclContext
2110   Abv->Add(BitCodeAbbrevOp(0));                       // isInvalidDecl
2111   Abv->Add(BitCodeAbbrevOp(0));                       // HasAttrs
2112   Abv->Add(BitCodeAbbrevOp(0));                       // isImplicit
2113   Abv->Add(BitCodeAbbrevOp(0));                       // isUsed
2114   Abv->Add(BitCodeAbbrevOp(0));                       // isReferenced
2115   Abv->Add(BitCodeAbbrevOp(0));                   // TopLevelDeclInObjCContainer
2116   Abv->Add(BitCodeAbbrevOp(AS_none));                 // C++ AccessSpecifier
2117   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); // ModuleOwnershipKind
2118   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // SubmoduleID
2119   // NamedDecl
2120   Abv->Add(BitCodeAbbrevOp(0));                       // NameKind = Identifier
2121   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Name
2122   Abv->Add(BitCodeAbbrevOp(0));                       // AnonDeclNumber
2123   // ValueDecl
2124   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
2125   // DeclaratorDecl
2126   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // InnerStartLoc
2127   Abv->Add(BitCodeAbbrevOp(0));                       // hasExtInfo
2128   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // TSIType
2129   // VarDecl
2130   Abv->Add(BitCodeAbbrevOp(0));                       // SClass
2131   Abv->Add(BitCodeAbbrevOp(0));                       // TSCSpec
2132   Abv->Add(BitCodeAbbrevOp(0));                       // InitStyle
2133   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isARCPseudoStrong
2134   Abv->Add(BitCodeAbbrevOp(0));                       // Linkage
2135   Abv->Add(BitCodeAbbrevOp(0));                       // HasInit
2136   Abv->Add(BitCodeAbbrevOp(0));                   // HasMemberSpecializationInfo
2137   // ParmVarDecl
2138   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsObjCMethodParameter
2139   Abv->Add(BitCodeAbbrevOp(0));                       // ScopeDepth
2140   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // ScopeIndex
2141   Abv->Add(BitCodeAbbrevOp(0));                       // ObjCDeclQualifier
2142   Abv->Add(BitCodeAbbrevOp(0));                       // KNRPromoted
2143   Abv->Add(BitCodeAbbrevOp(0));                       // HasInheritedDefaultArg
2144   Abv->Add(BitCodeAbbrevOp(0));                   // HasUninstantiatedDefaultArg
2145   // Type Source Info
2146   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2147   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // TypeLoc
2148   DeclParmVarAbbrev = Stream.EmitAbbrev(std::move(Abv));
2149
2150   // Abbreviation for DECL_TYPEDEF
2151   Abv = std::make_shared<BitCodeAbbrev>();
2152   Abv->Add(BitCodeAbbrevOp(serialization::DECL_TYPEDEF));
2153   // Redeclarable
2154   Abv->Add(BitCodeAbbrevOp(0));                       // No redeclaration
2155   // Decl
2156   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclContext
2157   Abv->Add(BitCodeAbbrevOp(0));                       // LexicalDeclContext
2158   Abv->Add(BitCodeAbbrevOp(0));                       // isInvalidDecl
2159   Abv->Add(BitCodeAbbrevOp(0));                       // HasAttrs
2160   Abv->Add(BitCodeAbbrevOp(0));                       // isImplicit
2161   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isUsed
2162   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isReferenced
2163   Abv->Add(BitCodeAbbrevOp(0));                   // TopLevelDeclInObjCContainer
2164   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2)); // C++ AccessSpecifier
2165   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); // ModuleOwnershipKind
2166   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // SubmoduleID
2167   // NamedDecl
2168   Abv->Add(BitCodeAbbrevOp(0));                       // NameKind = Identifier
2169   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Name
2170   Abv->Add(BitCodeAbbrevOp(0));                       // AnonDeclNumber
2171   // TypeDecl
2172   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Source Location
2173   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type Ref
2174   // TypedefDecl
2175   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2176   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // TypeLoc
2177   DeclTypedefAbbrev = Stream.EmitAbbrev(std::move(Abv));
2178
2179   // Abbreviation for DECL_VAR
2180   Abv = std::make_shared<BitCodeAbbrev>();
2181   Abv->Add(BitCodeAbbrevOp(serialization::DECL_VAR));
2182   // Redeclarable
2183   Abv->Add(BitCodeAbbrevOp(0));                       // No redeclaration
2184   // Decl
2185   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclContext
2186   Abv->Add(BitCodeAbbrevOp(0));                       // LexicalDeclContext
2187   Abv->Add(BitCodeAbbrevOp(0));                       // isInvalidDecl
2188   Abv->Add(BitCodeAbbrevOp(0));                       // HasAttrs
2189   Abv->Add(BitCodeAbbrevOp(0));                       // isImplicit
2190   Abv->Add(BitCodeAbbrevOp(0));                       // isUsed
2191   Abv->Add(BitCodeAbbrevOp(0));                       // isReferenced
2192   Abv->Add(BitCodeAbbrevOp(0));                   // TopLevelDeclInObjCContainer
2193   Abv->Add(BitCodeAbbrevOp(AS_none));                 // C++ AccessSpecifier
2194   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); // ModuleOwnershipKind
2195   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // SubmoduleID
2196   // NamedDecl
2197   Abv->Add(BitCodeAbbrevOp(0));                       // NameKind = Identifier
2198   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Name
2199   Abv->Add(BitCodeAbbrevOp(0));                       // AnonDeclNumber
2200   // ValueDecl
2201   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
2202   // DeclaratorDecl
2203   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // InnerStartLoc
2204   Abv->Add(BitCodeAbbrevOp(0));                       // hasExtInfo
2205   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // TSIType
2206   // VarDecl
2207   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); // SClass
2208   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2)); // TSCSpec
2209   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2)); // InitStyle
2210   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isARCPseudoStrong
2211   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsThisDeclarationADemotedDefinition
2212   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isExceptionVariable
2213   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isNRVOVariable
2214   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isCXXForRangeDecl
2215   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isObjCForDecl
2216   Abv->Add(BitCodeAbbrevOp(0));                         // isInline
2217   Abv->Add(BitCodeAbbrevOp(0));                         // isInlineSpecified
2218   Abv->Add(BitCodeAbbrevOp(0));                         // isConstexpr
2219   Abv->Add(BitCodeAbbrevOp(0));                         // isInitCapture
2220   Abv->Add(BitCodeAbbrevOp(0));                         // isPrevDeclInSameScope
2221   Abv->Add(BitCodeAbbrevOp(0));                         // ImplicitParamKind
2222   Abv->Add(BitCodeAbbrevOp(0));                         // EscapingByref
2223   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); // Linkage
2224   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); // HasConstant*
2225   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2)); // VarKind (local enum)
2226   // Type Source Info
2227   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2228   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // TypeLoc
2229   DeclVarAbbrev = Stream.EmitAbbrev(std::move(Abv));
2230
2231   // Abbreviation for DECL_CXX_METHOD
2232   Abv = std::make_shared<BitCodeAbbrev>();
2233   Abv->Add(BitCodeAbbrevOp(serialization::DECL_CXX_METHOD));
2234   // RedeclarableDecl
2235   Abv->Add(BitCodeAbbrevOp(0));                         // CanonicalDecl
2236   // Decl
2237   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // DeclContext
2238   Abv->Add(BitCodeAbbrevOp(0));                         // LexicalDeclContext
2239   Abv->Add(BitCodeAbbrevOp(0));                         // Invalid
2240   Abv->Add(BitCodeAbbrevOp(0));                         // HasAttrs
2241   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Implicit
2242   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Used
2243   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Referenced
2244   Abv->Add(BitCodeAbbrevOp(0));                         // InObjCContainer
2245   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2)); // Access
2246   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); // ModuleOwnershipKind
2247   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // SubmoduleID
2248   // NamedDecl
2249   Abv->Add(BitCodeAbbrevOp(DeclarationName::Identifier)); // NameKind
2250   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // Identifier
2251   Abv->Add(BitCodeAbbrevOp(0));                         // AnonDeclNumber
2252   // ValueDecl
2253   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // Type
2254   // DeclaratorDecl
2255   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // InnerLocStart
2256   Abv->Add(BitCodeAbbrevOp(0));                         // HasExtInfo
2257   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // TSIType
2258   // FunctionDecl
2259   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 11)); // IDNS
2260   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); // StorageClass
2261   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Inline
2262   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // InlineSpecified
2263   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // VirtualAsWritten
2264   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Pure
2265   Abv->Add(BitCodeAbbrevOp(0));                         // HasInheritedProto
2266   Abv->Add(BitCodeAbbrevOp(1));                         // HasWrittenProto
2267   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Deleted
2268   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Trivial
2269   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // TrivialForCall
2270   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Defaulted
2271   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // ExplicitlyDefaulted
2272   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // ImplicitReturnZero
2273   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2)); // Constexpr
2274   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // UsesSEHTry
2275   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // SkippedBody
2276   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // MultiVersion
2277   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // LateParsed
2278   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); // Linkage
2279   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // LocEnd
2280   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // ODRHash
2281   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); // TemplateKind
2282   // This Array slurps the rest of the record. Fortunately we want to encode
2283   // (nearly) all the remaining (variable number of) fields in the same way.
2284   //
2285   // This is the function template information if any, then
2286   //         NumParams and Params[] from FunctionDecl, and
2287   //         NumOverriddenMethods, OverriddenMethods[] from CXXMethodDecl.
2288   //
2289   //  Add an AbbrevOp for 'size then elements' and use it here.
2290   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2291   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
2292   DeclCXXMethodAbbrev = Stream.EmitAbbrev(std::move(Abv));
2293
2294   unsigned ExprDependenceBits = llvm::BitWidth<ExprDependence>;
2295   // Abbreviation for EXPR_DECL_REF
2296   Abv = std::make_shared<BitCodeAbbrev>();
2297   Abv->Add(BitCodeAbbrevOp(serialization::EXPR_DECL_REF));
2298   //Stmt
2299   // Expr
2300   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
2301   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, ExprDependenceBits));
2302   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetValueKind
2303   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetObjectKind
2304   //DeclRefExpr
2305   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //HasQualifier
2306   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //GetDeclFound
2307   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //ExplicitTemplateArgs
2308   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //HadMultipleCandidates
2309   Abv->Add(BitCodeAbbrevOp(0)); // RefersToEnclosingVariableOrCapture
2310   Abv->Add(BitCodeAbbrevOp(0)); // NonOdrUseReason
2311   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclRef
2312   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Location
2313   DeclRefExprAbbrev = Stream.EmitAbbrev(std::move(Abv));
2314
2315   // Abbreviation for EXPR_INTEGER_LITERAL
2316   Abv = std::make_shared<BitCodeAbbrev>();
2317   Abv->Add(BitCodeAbbrevOp(serialization::EXPR_INTEGER_LITERAL));
2318   //Stmt
2319   // Expr
2320   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
2321   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, ExprDependenceBits));
2322   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetValueKind
2323   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetObjectKind
2324   //Integer Literal
2325   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Location
2326   Abv->Add(BitCodeAbbrevOp(32));                      // Bit Width
2327   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Value
2328   IntegerLiteralAbbrev = Stream.EmitAbbrev(std::move(Abv));
2329
2330   // Abbreviation for EXPR_CHARACTER_LITERAL
2331   Abv = std::make_shared<BitCodeAbbrev>();
2332   Abv->Add(BitCodeAbbrevOp(serialization::EXPR_CHARACTER_LITERAL));
2333   //Stmt
2334   // Expr
2335   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
2336   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, ExprDependenceBits));
2337   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetValueKind
2338   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetObjectKind
2339   //Character Literal
2340   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // getValue
2341   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Location
2342   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); // getKind
2343   CharacterLiteralAbbrev = Stream.EmitAbbrev(std::move(Abv));
2344
2345   // Abbreviation for EXPR_IMPLICIT_CAST
2346   Abv = std::make_shared<BitCodeAbbrev>();
2347   Abv->Add(BitCodeAbbrevOp(serialization::EXPR_IMPLICIT_CAST));
2348   // Stmt
2349   // Expr
2350   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
2351   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, ExprDependenceBits));
2352   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetValueKind
2353   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetObjectKind
2354   // CastExpr
2355   Abv->Add(BitCodeAbbrevOp(0)); // PathSize
2356   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // HasFPFeatures
2357   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 6)); // CastKind
2358   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // PartOfExplicitCast
2359   // ImplicitCastExpr
2360   ExprImplicitCastAbbrev = Stream.EmitAbbrev(std::move(Abv));
2361
2362   Abv = std::make_shared<BitCodeAbbrev>();
2363   Abv->Add(BitCodeAbbrevOp(serialization::DECL_CONTEXT_LEXICAL));
2364   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
2365   DeclContextLexicalAbbrev = Stream.EmitAbbrev(std::move(Abv));
2366
2367   Abv = std::make_shared<BitCodeAbbrev>();
2368   Abv->Add(BitCodeAbbrevOp(serialization::DECL_CONTEXT_VISIBLE));
2369   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
2370   DeclContextVisibleLookupAbbrev = Stream.EmitAbbrev(std::move(Abv));
2371 }
2372
2373 /// isRequiredDecl - Check if this is a "required" Decl, which must be seen by
2374 /// consumers of the AST.
2375 ///
2376 /// Such decls will always be deserialized from the AST file, so we would like
2377 /// this to be as restrictive as possible. Currently the predicate is driven by
2378 /// code generation requirements, if other clients have a different notion of
2379 /// what is "required" then we may have to consider an alternate scheme where
2380 /// clients can iterate over the top-level decls and get information on them,
2381 /// without necessary deserializing them. We could explicitly require such
2382 /// clients to use a separate API call to "realize" the decl. This should be
2383 /// relatively painless since they would presumably only do it for top-level
2384 /// decls.
2385 static bool isRequiredDecl(const Decl *D, ASTContext &Context,
2386                            bool WritingModule) {
2387   // An ObjCMethodDecl is never considered as "required" because its
2388   // implementation container always is.
2389
2390   // File scoped assembly or obj-c or OMP declare target implementation must be
2391   // seen.
2392   if (isa<FileScopeAsmDecl>(D) || isa<ObjCImplDecl>(D))
2393     return true;
2394
2395   if (WritingModule && isPartOfPerModuleInitializer(D)) {
2396     // These declarations are part of the module initializer, and are emitted
2397     // if and when the module is imported, rather than being emitted eagerly.
2398     return false;
2399   }
2400
2401   return Context.DeclMustBeEmitted(D);
2402 }
2403
2404 void ASTWriter::WriteDecl(ASTContext &Context, Decl *D) {
2405   PrettyDeclStackTraceEntry CrashInfo(Context, D, SourceLocation(),
2406                                       "serializing");
2407
2408   // Determine the ID for this declaration.
2409   serialization::DeclID ID;
2410   assert(!D->isFromASTFile() && "should not be emitting imported decl");
2411   serialization::DeclID &IDR = DeclIDs[D];
2412   if (IDR == 0)
2413     IDR = NextDeclID++;
2414
2415   ID = IDR;
2416
2417   assert(ID >= FirstDeclID && "invalid decl ID");
2418
2419   RecordData Record;
2420   ASTDeclWriter W(*this, Context, Record);
2421
2422   // Build a record for this declaration
2423   W.Visit(D);
2424
2425   // Emit this declaration to the bitstream.
2426   uint64_t Offset = W.Emit(D);
2427
2428   // Record the offset for this declaration
2429   SourceLocation Loc = D->getLocation();
2430   unsigned Index = ID - FirstDeclID;
2431   if (DeclOffsets.size() == Index)
2432     DeclOffsets.emplace_back(Loc, Offset, DeclTypesBlockStartOffset);
2433   else if (DeclOffsets.size() < Index) {
2434     // FIXME: Can/should this happen?
2435     DeclOffsets.resize(Index+1);
2436     DeclOffsets[Index].setLocation(Loc);
2437     DeclOffsets[Index].setBitOffset(Offset, DeclTypesBlockStartOffset);
2438   } else {
2439     llvm_unreachable("declarations should be emitted in ID order");
2440   }
2441
2442   SourceManager &SM = Context.getSourceManager();
2443   if (Loc.isValid() && SM.isLocalSourceLocation(Loc))
2444     associateDeclWithFile(D, ID);
2445
2446   // Note declarations that should be deserialized eagerly so that we can add
2447   // them to a record in the AST file later.
2448   if (isRequiredDecl(D, Context, WritingModule))
2449     EagerlyDeserializedDecls.push_back(ID);
2450 }
2451
2452 void ASTRecordWriter::AddFunctionDefinition(const FunctionDecl *FD) {
2453   // Switch case IDs are per function body.
2454   Writer->ClearSwitchCaseIDs();
2455
2456   assert(FD->doesThisDeclarationHaveABody());
2457   bool ModulesCodegen = false;
2458   if (!FD->isDependentContext()) {
2459     Optional<GVALinkage> Linkage;
2460     if (Writer->WritingModule &&
2461         Writer->WritingModule->isInterfaceOrPartition()) {
2462       // When building a C++20 module interface unit or a partition unit, a
2463       // strong definition in the module interface is provided by the
2464       // compilation of that unit, not by its users. (Inline functions are still
2465       // emitted in module users.)
2466       Linkage = Writer->Context->GetGVALinkageForFunction(FD);
2467       ModulesCodegen = *Linkage == GVA_StrongExternal;
2468     }
2469     if (Writer->Context->getLangOpts().ModulesCodegen ||
2470         (FD->hasAttr<DLLExportAttr>() &&
2471          Writer->Context->getLangOpts().BuildingPCHWithObjectFile)) {
2472
2473       // Under -fmodules-codegen, codegen is performed for all non-internal,
2474       // non-always_inline functions, unless they are available elsewhere.
2475       if (!FD->hasAttr<AlwaysInlineAttr>()) {
2476         if (!Linkage)
2477           Linkage = Writer->Context->GetGVALinkageForFunction(FD);
2478         ModulesCodegen =
2479             *Linkage != GVA_Internal && *Linkage != GVA_AvailableExternally;
2480       }
2481     }
2482   }
2483   Record->push_back(ModulesCodegen);
2484   if (ModulesCodegen)
2485     Writer->ModularCodegenDecls.push_back(Writer->GetDeclRef(FD));
2486   if (auto *CD = dyn_cast<CXXConstructorDecl>(FD)) {
2487     Record->push_back(CD->getNumCtorInitializers());
2488     if (CD->getNumCtorInitializers())
2489       AddCXXCtorInitializers(
2490           llvm::makeArrayRef(CD->init_begin(), CD->init_end()));
2491   }
2492   AddStmt(FD->getBody());
2493 }