contrib/llvm/tools/clang/lib/Serialization/ASTWriterDecl.cpp

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