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