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