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->getTemplatedKind());
 542   switch (D->getTemplatedKind()) {
 543   case FunctionDecl::TK_NonTemplate:
 544     break;
 545   case FunctionDecl::TK_FunctionTemplate:
 546     Record.AddDeclRef(D->getDescribedFunctionTemplate());
 547     break;
 548   case FunctionDecl::TK_MemberSpecialization: {
 549     MemberSpecializationInfo *MemberInfo = D->getMemberSpecializationInfo();
 550     Record.AddDeclRef(MemberInfo->getInstantiatedFrom());
 551     Record.push_back(MemberInfo->getTemplateSpecializationKind());
 552     Record.AddSourceLocation(MemberInfo->getPointOfInstantiation());
 553     break;
 554   }
 555   case FunctionDecl::TK_FunctionTemplateSpecialization: {
 556     FunctionTemplateSpecializationInfo *
 557       FTSInfo = D->getTemplateSpecializationInfo();
 558
 559     RegisterTemplateSpecialization(FTSInfo->getTemplate(), D);
 560
 561     Record.AddDeclRef(FTSInfo->getTemplate());
 562     Record.push_back(FTSInfo->getTemplateSpecializationKind());
 563
 564     // Template arguments.
 565     Record.AddTemplateArgumentList(FTSInfo->TemplateArguments);
 566
 567     // Template args as written.
 568     Record.push_back(FTSInfo->TemplateArgumentsAsWritten != nullptr);
 569     if (FTSInfo->TemplateArgumentsAsWritten) {
 570       Record.push_back(FTSInfo->TemplateArgumentsAsWritten->NumTemplateArgs);
 571       for (int i=0, e = FTSInfo->TemplateArgumentsAsWritten->NumTemplateArgs;
 572              i!=e; ++i)
 573         Record.AddTemplateArgumentLoc(
 574             (*FTSInfo->TemplateArgumentsAsWritten)[i]);
 575       Record.AddSourceLocation(FTSInfo->TemplateArgumentsAsWritten->LAngleLoc);
 576       Record.AddSourceLocation(FTSInfo->TemplateArgumentsAsWritten->RAngleLoc);
 577     }
 578
 579     Record.AddSourceLocation(FTSInfo->getPointOfInstantiation());
 580
 581     if (D->isCanonicalDecl()) {
 582       // Write the template that contains the specializations set. We will
 583       // add a FunctionTemplateSpecializationInfo to it when reading.
 584       Record.AddDeclRef(FTSInfo->getTemplate()->getCanonicalDecl());
 585     }
 586     break;
 587   }
 588   case FunctionDecl::TK_DependentFunctionTemplateSpecialization: {
 589     DependentFunctionTemplateSpecializationInfo *
 590       DFTSInfo = D->getDependentSpecializationInfo();
 591
 592     // Templates.
 593     Record.push_back(DFTSInfo->getNumTemplates());
 594     for (int i=0, e = DFTSInfo->getNumTemplates(); i != e; ++i)
 595       Record.AddDeclRef(DFTSInfo->getTemplate(i));
 596
 597     // Templates args.
 598     Record.push_back(DFTSInfo->getNumTemplateArgs());
 599     for (int i=0, e = DFTSInfo->getNumTemplateArgs(); i != e; ++i)
 600       Record.AddTemplateArgumentLoc(DFTSInfo->getTemplateArg(i));
 601     Record.AddSourceLocation(DFTSInfo->getLAngleLoc());
 602     Record.AddSourceLocation(DFTSInfo->getRAngleLoc());
 603     break;
 604   }
 605   }
 606
 607   Record.push_back(D->param_size());
 608   for (auto P : D->parameters())
 609     Record.AddDeclRef(P);
 610   Code = serialization::DECL_FUNCTION;
 611 }
 612
 613 void ASTDeclWriter::VisitCXXDeductionGuideDecl(CXXDeductionGuideDecl *D) {
 614   VisitFunctionDecl(D);
 615   Code = serialization::DECL_CXX_DEDUCTION_GUIDE;
 616 }
 617
 618 void ASTDeclWriter::VisitObjCMethodDecl(ObjCMethodDecl *D) {
 619   VisitNamedDecl(D);
 620   // FIXME: convert to LazyStmtPtr?
 621   // Unlike C/C++, method bodies will never be in header files.
 622   bool HasBodyStuff = D->getBody() != nullptr     ||
 623                       D->getSelfDecl() != nullptr || D->getCmdDecl() != nullptr;
 624   Record.push_back(HasBodyStuff);
 625   if (HasBodyStuff) {
 626     Record.AddStmt(D->getBody());
 627     Record.AddDeclRef(D->getSelfDecl());
 628     Record.AddDeclRef(D->getCmdDecl());
 629   }
 630   Record.push_back(D->isInstanceMethod());
 631   Record.push_back(D->isVariadic());
 632   Record.push_back(D->isPropertyAccessor());
 633   Record.push_back(D->isDefined());
 634   Record.push_back(D->IsOverriding);
 635   Record.push_back(D->HasSkippedBody);
 636
 637   Record.push_back(D->IsRedeclaration);
 638   Record.push_back(D->HasRedeclaration);
 639   if (D->HasRedeclaration) {
 640     assert(Context.getObjCMethodRedeclaration(D));
 641     Record.AddDeclRef(Context.getObjCMethodRedeclaration(D));
 642   }
 643
 644   // FIXME: stable encoding for @required/@optional
 645   Record.push_back(D->getImplementationControl());
 646   // FIXME: stable encoding for in/out/inout/bycopy/byref/oneway/nullability
 647   Record.push_back(D->getObjCDeclQualifier());
 648   Record.push_back(D->hasRelatedResultType());
 649   Record.AddTypeRef(D->getReturnType());
 650   Record.AddTypeSourceInfo(D->getReturnTypeSourceInfo());
 651   Record.AddSourceLocation(D->getLocEnd());
 652   Record.push_back(D->param_size());
 653   for (const auto *P : D->parameters())
 654     Record.AddDeclRef(P);
 655
 656   Record.push_back(D->SelLocsKind);
 657   unsigned NumStoredSelLocs = D->getNumStoredSelLocs();
 658   SourceLocation *SelLocs = D->getStoredSelLocs();
 659   Record.push_back(NumStoredSelLocs);
 660   for (unsigned i = 0; i != NumStoredSelLocs; ++i)
 661     Record.AddSourceLocation(SelLocs[i]);
 662
 663   Code = serialization::DECL_OBJC_METHOD;
 664 }
 665
 666 void ASTDeclWriter::VisitObjCTypeParamDecl(ObjCTypeParamDecl *D) {
 667   VisitTypedefNameDecl(D);
 668   Record.push_back(D->Variance);
 669   Record.push_back(D->Index);
 670   Record.AddSourceLocation(D->VarianceLoc);
 671   Record.AddSourceLocation(D->ColonLoc);
 672
 673   Code = serialization::DECL_OBJC_TYPE_PARAM;
 674 }
 675
 676 void ASTDeclWriter::VisitObjCContainerDecl(ObjCContainerDecl *D) {
 677   VisitNamedDecl(D);
 678   Record.AddSourceLocation(D->getAtStartLoc());
 679   Record.AddSourceRange(D->getAtEndRange());
 680   // Abstract class (no need to define a stable serialization::DECL code).
 681 }
 682
 683 void ASTDeclWriter::VisitObjCInterfaceDecl(ObjCInterfaceDecl *D) {
 684   VisitRedeclarable(D);
 685   VisitObjCContainerDecl(D);
 686   Record.AddTypeRef(QualType(D->getTypeForDecl(), 0));
 687   AddObjCTypeParamList(D->TypeParamList);
 688
 689   Record.push_back(D->isThisDeclarationADefinition());
 690   if (D->isThisDeclarationADefinition()) {
 691     // Write the DefinitionData
 692     ObjCInterfaceDecl::DefinitionData &Data = D->data();
 693
 694     Record.AddTypeSourceInfo(D->getSuperClassTInfo());
 695     Record.AddSourceLocation(D->getEndOfDefinitionLoc());
 696     Record.push_back(Data.HasDesignatedInitializers);
 697
 698     // Write out the protocols that are directly referenced by the @interface.
 699     Record.push_back(Data.ReferencedProtocols.size());
 700     for (const auto *P : D->protocols())
 701       Record.AddDeclRef(P);
 702     for (const auto &PL : D->protocol_locs())
 703       Record.AddSourceLocation(PL);
 704
 705     // Write out the protocols that are transitively referenced.
 706     Record.push_back(Data.AllReferencedProtocols.size());
 707     for (ObjCList<ObjCProtocolDecl>::iterator
 708               P = Data.AllReferencedProtocols.begin(),
 709            PEnd = Data.AllReferencedProtocols.end();
 710          P != PEnd; ++P)
 711       Record.AddDeclRef(*P);
 712
 713
 714     if (ObjCCategoryDecl *Cat = D->getCategoryListRaw()) {
 715       // Ensure that we write out the set of categories for this class.
 716       Writer.ObjCClassesWithCategories.insert(D);
 717
 718       // Make sure that the categories get serialized.
 719       for (; Cat; Cat = Cat->getNextClassCategoryRaw())
 720         (void)Writer.GetDeclRef(Cat);
 721     }
 722   }
 723
 724   Code = serialization::DECL_OBJC_INTERFACE;
 725 }
 726
 727 void ASTDeclWriter::VisitObjCIvarDecl(ObjCIvarDecl *D) {
 728   VisitFieldDecl(D);
 729   // FIXME: stable encoding for @public/@private/@protected/@package
 730   Record.push_back(D->getAccessControl());
 731   Record.push_back(D->getSynthesize());
 732
 733   if (D->getDeclContext() == D->getLexicalDeclContext() &&
 734       !D->hasAttrs() &&
 735       !D->isImplicit() &&
 736       !D->isUsed(false) &&
 737       !D->isInvalidDecl() &&
 738       !D->isReferenced() &&
 739       !D->isModulePrivate() &&
 740       !D->getBitWidth() &&
 741       !D->hasExtInfo() &&
 742       D->getDeclName())
 743     AbbrevToUse = Writer.getDeclObjCIvarAbbrev();
 744
 745   Code = serialization::DECL_OBJC_IVAR;
 746 }
 747
 748 void ASTDeclWriter::VisitObjCProtocolDecl(ObjCProtocolDecl *D) {
 749   VisitRedeclarable(D);
 750   VisitObjCContainerDecl(D);
 751
 752   Record.push_back(D->isThisDeclarationADefinition());
 753   if (D->isThisDeclarationADefinition()) {
 754     Record.push_back(D->protocol_size());
 755     for (const auto *I : D->protocols())
 756       Record.AddDeclRef(I);
 757     for (const auto &PL : D->protocol_locs())
 758       Record.AddSourceLocation(PL);
 759   }
 760
 761   Code = serialization::DECL_OBJC_PROTOCOL;
 762 }
 763
 764 void ASTDeclWriter::VisitObjCAtDefsFieldDecl(ObjCAtDefsFieldDecl *D) {
 765   VisitFieldDecl(D);
 766   Code = serialization::DECL_OBJC_AT_DEFS_FIELD;
 767 }
 768
 769 void ASTDeclWriter::VisitObjCCategoryDecl(ObjCCategoryDecl *D) {
 770   VisitObjCContainerDecl(D);
 771   Record.AddSourceLocation(D->getCategoryNameLoc());
 772   Record.AddSourceLocation(D->getIvarLBraceLoc());
 773   Record.AddSourceLocation(D->getIvarRBraceLoc());
 774   Record.AddDeclRef(D->getClassInterface());
 775   AddObjCTypeParamList(D->TypeParamList);
 776   Record.push_back(D->protocol_size());
 777   for (const auto *I : D->protocols())
 778     Record.AddDeclRef(I);
 779   for (const auto &PL : D->protocol_locs())
 780     Record.AddSourceLocation(PL);
 781   Code = serialization::DECL_OBJC_CATEGORY;
 782 }
 783
 784 void ASTDeclWriter::VisitObjCCompatibleAliasDecl(ObjCCompatibleAliasDecl *D) {
 785   VisitNamedDecl(D);
 786   Record.AddDeclRef(D->getClassInterface());
 787   Code = serialization::DECL_OBJC_COMPATIBLE_ALIAS;
 788 }
 789
 790 void ASTDeclWriter::VisitObjCPropertyDecl(ObjCPropertyDecl *D) {
 791   VisitNamedDecl(D);
 792   Record.AddSourceLocation(D->getAtLoc());
 793   Record.AddSourceLocation(D->getLParenLoc());
 794   Record.AddTypeRef(D->getType());
 795   Record.AddTypeSourceInfo(D->getTypeSourceInfo());
 796   // FIXME: stable encoding
 797   Record.push_back((unsigned)D->getPropertyAttributes());
 798   Record.push_back((unsigned)D->getPropertyAttributesAsWritten());
 799   // FIXME: stable encoding
 800   Record.push_back((unsigned)D->getPropertyImplementation());
 801   Record.AddDeclarationName(D->getGetterName());
 802   Record.AddSourceLocation(D->getGetterNameLoc());
 803   Record.AddDeclarationName(D->getSetterName());
 804   Record.AddSourceLocation(D->getSetterNameLoc());
 805   Record.AddDeclRef(D->getGetterMethodDecl());
 806   Record.AddDeclRef(D->getSetterMethodDecl());
 807   Record.AddDeclRef(D->getPropertyIvarDecl());
 808   Code = serialization::DECL_OBJC_PROPERTY;
 809 }
 810
 811 void ASTDeclWriter::VisitObjCImplDecl(ObjCImplDecl *D) {
 812   VisitObjCContainerDecl(D);
 813   Record.AddDeclRef(D->getClassInterface());
 814   // Abstract class (no need to define a stable serialization::DECL code).
 815 }
 816
 817 void ASTDeclWriter::VisitObjCCategoryImplDecl(ObjCCategoryImplDecl *D) {
 818   VisitObjCImplDecl(D);
 819   Record.AddSourceLocation(D->getCategoryNameLoc());
 820   Code = serialization::DECL_OBJC_CATEGORY_IMPL;
 821 }
 822
 823 void ASTDeclWriter::VisitObjCImplementationDecl(ObjCImplementationDecl *D) {
 824   VisitObjCImplDecl(D);
 825   Record.AddDeclRef(D->getSuperClass());
 826   Record.AddSourceLocation(D->getSuperClassLoc());
 827   Record.AddSourceLocation(D->getIvarLBraceLoc());
 828   Record.AddSourceLocation(D->getIvarRBraceLoc());
 829   Record.push_back(D->hasNonZeroConstructors());
 830   Record.push_back(D->hasDestructors());
 831   Record.push_back(D->NumIvarInitializers);
 832   if (D->NumIvarInitializers)
 833     Record.AddCXXCtorInitializers(
 834         llvm::makeArrayRef(D->init_begin(), D->init_end()));
 835   Code = serialization::DECL_OBJC_IMPLEMENTATION;
 836 }
 837
 838 void ASTDeclWriter::VisitObjCPropertyImplDecl(ObjCPropertyImplDecl *D) {
 839   VisitDecl(D);
 840   Record.AddSourceLocation(D->getLocStart());
 841   Record.AddDeclRef(D->getPropertyDecl());
 842   Record.AddDeclRef(D->getPropertyIvarDecl());
 843   Record.AddSourceLocation(D->getPropertyIvarDeclLoc());
 844   Record.AddStmt(D->getGetterCXXConstructor());
 845   Record.AddStmt(D->getSetterCXXAssignment());
 846   Code = serialization::DECL_OBJC_PROPERTY_IMPL;
 847 }
 848
 849 void ASTDeclWriter::VisitFieldDecl(FieldDecl *D) {
 850   VisitDeclaratorDecl(D);
 851   Record.push_back(D->isMutable());
 852   if (D->InitStorage.getInt() == FieldDecl::ISK_BitWidthOrNothing &&
 853       D->InitStorage.getPointer() == nullptr) {
 854     Record.push_back(0);
 855   } else if (D->InitStorage.getInt() == FieldDecl::ISK_CapturedVLAType) {
 856     Record.push_back(D->InitStorage.getInt() + 1);
 857     Record.AddTypeRef(
 858         QualType(static_cast<Type *>(D->InitStorage.getPointer()), 0));
 859   } else {
 860     Record.push_back(D->InitStorage.getInt() + 1);
 861     Record.AddStmt(static_cast<Expr *>(D->InitStorage.getPointer()));
 862   }
 863   if (!D->getDeclName())
 864     Record.AddDeclRef(Context.getInstantiatedFromUnnamedFieldDecl(D));
 865
 866   if (D->getDeclContext() == D->getLexicalDeclContext() &&
 867       !D->hasAttrs() &&
 868       !D->isImplicit() &&
 869       !D->isUsed(false) &&
 870       !D->isInvalidDecl() &&
 871       !D->isReferenced() &&
 872       !D->isTopLevelDeclInObjCContainer() &&
 873       !D->isModulePrivate() &&
 874       !D->getBitWidth() &&
 875       !D->hasInClassInitializer() &&
 876       !D->hasExtInfo() &&
 877       !ObjCIvarDecl::classofKind(D->getKind()) &&
 878       !ObjCAtDefsFieldDecl::classofKind(D->getKind()) &&
 879       D->getDeclName())
 880     AbbrevToUse = Writer.getDeclFieldAbbrev();
 881
 882   Code = serialization::DECL_FIELD;
 883 }
 884
 885 void ASTDeclWriter::VisitMSPropertyDecl(MSPropertyDecl *D) {
 886   VisitDeclaratorDecl(D);
 887   Record.AddIdentifierRef(D->getGetterId());
 888   Record.AddIdentifierRef(D->getSetterId());
 889   Code = serialization::DECL_MS_PROPERTY;
 890 }
 891
 892 void ASTDeclWriter::VisitIndirectFieldDecl(IndirectFieldDecl *D) {
 893   VisitValueDecl(D);
 894   Record.push_back(D->getChainingSize());
 895
 896   for (const auto *P : D->chain())
 897     Record.AddDeclRef(P);
 898   Code = serialization::DECL_INDIRECTFIELD;
 899 }
 900
 901 void ASTDeclWriter::VisitVarDecl(VarDecl *D) {
 902   VisitRedeclarable(D);
 903   VisitDeclaratorDecl(D);
 904   Record.push_back(D->getStorageClass());
 905   Record.push_back(D->getTSCSpec());
 906   Record.push_back(D->getInitStyle());
 907   if (!isa<ParmVarDecl>(D)) {
 908     Record.push_back(D->isThisDeclarationADemotedDefinition());
 909     Record.push_back(D->isExceptionVariable());
 910     Record.push_back(D->isNRVOVariable());
 911     Record.push_back(D->isCXXForRangeDecl());
 912     Record.push_back(D->isARCPseudoStrong());
 913     Record.push_back(D->isInline());
 914     Record.push_back(D->isInlineSpecified());
 915     Record.push_back(D->isConstexpr());
 916     Record.push_back(D->isInitCapture());
 917     Record.push_back(D->isPreviousDeclInSameBlockScope());
 918   }
 919   Record.push_back(D->getLinkageInternal());
 920
 921   if (D->getInit()) {
 922     Record.push_back(!D->isInitKnownICE() ? 1 : (D->isInitICE() ? 3 : 2));
 923     Record.AddStmt(D->getInit());
 924   } else {
 925     Record.push_back(0);
 926   }
 927
 928   enum {
 929     VarNotTemplate = 0, VarTemplate, StaticDataMemberSpecialization
 930   };
 931   if (VarTemplateDecl *TemplD = D->getDescribedVarTemplate()) {
 932     Record.push_back(VarTemplate);
 933     Record.AddDeclRef(TemplD);
 934   } else if (MemberSpecializationInfo *SpecInfo
 935                = D->getMemberSpecializationInfo()) {
 936     Record.push_back(StaticDataMemberSpecialization);
 937     Record.AddDeclRef(SpecInfo->getInstantiatedFrom());
 938     Record.push_back(SpecInfo->getTemplateSpecializationKind());
 939     Record.AddSourceLocation(SpecInfo->getPointOfInstantiation());
 940   } else {
 941     Record.push_back(VarNotTemplate);
 942   }
 943
 944   if (D->getDeclContext() == D->getLexicalDeclContext() &&
 945       !D->hasAttrs() &&
 946       !D->isImplicit() &&
 947       !D->isUsed(false) &&
 948       !D->isInvalidDecl() &&
 949       !D->isReferenced() &&
 950       !D->isTopLevelDeclInObjCContainer() &&
 951       D->getAccess() == AS_none &&
 952       !D->isModulePrivate() &&
 953       !needsAnonymousDeclarationNumber(D) &&
 954       D->getDeclName().getNameKind() == DeclarationName::Identifier &&
 955       !D->hasExtInfo() &&
 956       D->getFirstDecl() == D->getMostRecentDecl() &&
 957       D->getKind() == Decl::Var &&
 958       !D->isInline() &&
 959       !D->isConstexpr() &&
 960       !D->isInitCapture() &&
 961       !D->isPreviousDeclInSameBlockScope() &&
 962       !D->getMemberSpecializationInfo())
 963     AbbrevToUse = Writer.getDeclVarAbbrev();
 964
 965   Code = serialization::DECL_VAR;
 966 }
 967
 968 void ASTDeclWriter::VisitImplicitParamDecl(ImplicitParamDecl *D) {
 969   VisitVarDecl(D);
 970   Code = serialization::DECL_IMPLICIT_PARAM;
 971 }
 972
 973 void ASTDeclWriter::VisitParmVarDecl(ParmVarDecl *D) {
 974   VisitVarDecl(D);
 975   Record.push_back(D->isObjCMethodParameter());
 976   Record.push_back(D->getFunctionScopeDepth());
 977   Record.push_back(D->getFunctionScopeIndex());
 978   Record.push_back(D->getObjCDeclQualifier()); // FIXME: stable encoding
 979   Record.push_back(D->isKNRPromoted());
 980   Record.push_back(D->hasInheritedDefaultArg());
 981   Record.push_back(D->hasUninstantiatedDefaultArg());
 982   if (D->hasUninstantiatedDefaultArg())
 983     Record.AddStmt(D->getUninstantiatedDefaultArg());
 984   Code = serialization::DECL_PARM_VAR;
 985
 986   assert(!D->isARCPseudoStrong()); // can be true of ImplicitParamDecl
 987
 988   // If the assumptions about the DECL_PARM_VAR abbrev are true, use it.  Here
 989   // we dynamically check for the properties that we optimize for, but don't
 990   // know are true of all PARM_VAR_DECLs.
 991   if (D->getDeclContext() == D->getLexicalDeclContext() &&
 992       !D->hasAttrs() &&
 993       !D->hasExtInfo() &&
 994       !D->isImplicit() &&
 995       !D->isUsed(false) &&
 996       !D->isInvalidDecl() &&
 997       !D->isReferenced() &&
 998       D->getAccess() == AS_none &&
 999       !D->isModulePrivate() &&
1000       D->getStorageClass() == 0 &&
1001       D->getInitStyle() == VarDecl::CInit && // Can params have anything else?
1002       D->getFunctionScopeDepth() == 0 &&
1003       D->getObjCDeclQualifier() == 0 &&
1004       !D->isKNRPromoted() &&
1005       !D->hasInheritedDefaultArg() &&
1006       D->getInit() == nullptr &&
1007       !D->hasUninstantiatedDefaultArg())  // No default expr.
1008     AbbrevToUse = Writer.getDeclParmVarAbbrev();
1009
1010   // Check things we know are true of *every* PARM_VAR_DECL, which is more than
1011   // just us assuming it.
1012   assert(!D->getTSCSpec() && "PARM_VAR_DECL can't use TLS");
1013   assert(!D->isThisDeclarationADemotedDefinition()
1014          && "PARM_VAR_DECL can't be demoted definition.");
1015   assert(D->getAccess() == AS_none && "PARM_VAR_DECL can't be public/private");
1016   assert(!D->isExceptionVariable() && "PARM_VAR_DECL can't be exception var");
1017   assert(D->getPreviousDecl() == nullptr && "PARM_VAR_DECL can't be redecl");
1018   assert(!D->isStaticDataMember() &&
1019          "PARM_VAR_DECL can't be static data member");
1020 }
1021
1022 void ASTDeclWriter::VisitDecompositionDecl(DecompositionDecl *D) {
1023   // Record the number of bindings first to simplify deserialization.
1024   Record.push_back(D->bindings().size());
1025
1026   VisitVarDecl(D);
1027   for (auto *B : D->bindings())
1028     Record.AddDeclRef(B);
1029   Code = serialization::DECL_DECOMPOSITION;
1030 }
1031
1032 void ASTDeclWriter::VisitBindingDecl(BindingDecl *D) {
1033   VisitValueDecl(D);
1034   Record.AddStmt(D->getBinding());
1035   Code = serialization::DECL_BINDING;
1036 }
1037
1038 void ASTDeclWriter::VisitFileScopeAsmDecl(FileScopeAsmDecl *D) {
1039   VisitDecl(D);
1040   Record.AddStmt(D->getAsmString());
1041   Record.AddSourceLocation(D->getRParenLoc());
1042   Code = serialization::DECL_FILE_SCOPE_ASM;
1043 }
1044
1045 void ASTDeclWriter::VisitEmptyDecl(EmptyDecl *D) {
1046   VisitDecl(D);
1047   Code = serialization::DECL_EMPTY;
1048 }
1049
1050 void ASTDeclWriter::VisitBlockDecl(BlockDecl *D) {
1051   VisitDecl(D);
1052   Record.AddStmt(D->getBody());
1053   Record.AddTypeSourceInfo(D->getSignatureAsWritten());
1054   Record.push_back(D->param_size());
1055   for (ParmVarDecl *P : D->parameters())
1056     Record.AddDeclRef(P);
1057   Record.push_back(D->isVariadic());
1058   Record.push_back(D->blockMissingReturnType());
1059   Record.push_back(D->isConversionFromLambda());
1060   Record.push_back(D->capturesCXXThis());
1061   Record.push_back(D->getNumCaptures());
1062   for (const auto &capture : D->captures()) {
1063     Record.AddDeclRef(capture.getVariable());
1064
1065     unsigned flags = 0;
1066     if (capture.isByRef()) flags |= 1;
1067     if (capture.isNested()) flags |= 2;
1068     if (capture.hasCopyExpr()) flags |= 4;
1069     Record.push_back(flags);
1070
1071     if (capture.hasCopyExpr()) Record.AddStmt(capture.getCopyExpr());
1072   }
1073
1074   Code = serialization::DECL_BLOCK;
1075 }
1076
1077 void ASTDeclWriter::VisitCapturedDecl(CapturedDecl *CD) {
1078   Record.push_back(CD->getNumParams());
1079   VisitDecl(CD);
1080   Record.push_back(CD->getContextParamPosition());
1081   Record.push_back(CD->isNothrow() ? 1 : 0);
1082   // Body is stored by VisitCapturedStmt.
1083   for (unsigned I = 0; I < CD->getNumParams(); ++I)
1084     Record.AddDeclRef(CD->getParam(I));
1085   Code = serialization::DECL_CAPTURED;
1086 }
1087
1088 void ASTDeclWriter::VisitLinkageSpecDecl(LinkageSpecDecl *D) {
1089   VisitDecl(D);
1090   Record.push_back(D->getLanguage());
1091   Record.AddSourceLocation(D->getExternLoc());
1092   Record.AddSourceLocation(D->getRBraceLoc());
1093   Code = serialization::DECL_LINKAGE_SPEC;
1094 }
1095
1096 void ASTDeclWriter::VisitExportDecl(ExportDecl *D) {
1097   VisitDecl(D);
1098   Record.AddSourceLocation(D->getRBraceLoc());
1099   Code = serialization::DECL_EXPORT;
1100 }
1101
1102 void ASTDeclWriter::VisitLabelDecl(LabelDecl *D) {
1103   VisitNamedDecl(D);
1104   Record.AddSourceLocation(D->getLocStart());
1105   Code = serialization::DECL_LABEL;
1106 }
1107
1108
1109 void ASTDeclWriter::VisitNamespaceDecl(NamespaceDecl *D) {
1110   VisitRedeclarable(D);
1111   VisitNamedDecl(D);
1112   Record.push_back(D->isInline());
1113   Record.AddSourceLocation(D->getLocStart());
1114   Record.AddSourceLocation(D->getRBraceLoc());
1115
1116   if (D->isOriginalNamespace())
1117     Record.AddDeclRef(D->getAnonymousNamespace());
1118   Code = serialization::DECL_NAMESPACE;
1119
1120   if (Writer.hasChain() && D->isAnonymousNamespace() &&
1121       D == D->getMostRecentDecl()) {
1122     // This is a most recent reopening of the anonymous namespace. If its parent
1123     // is in a previous PCH (or is the TU), mark that parent for update, because
1124     // the original namespace always points to the latest re-opening of its
1125     // anonymous namespace.
1126     Decl *Parent = cast<Decl>(
1127         D->getParent()->getRedeclContext()->getPrimaryContext());
1128     if (Parent->isFromASTFile() || isa<TranslationUnitDecl>(Parent)) {
1129       Writer.DeclUpdates[Parent].push_back(
1130           ASTWriter::DeclUpdate(UPD_CXX_ADDED_ANONYMOUS_NAMESPACE, D));
1131     }
1132   }
1133 }
1134
1135 void ASTDeclWriter::VisitNamespaceAliasDecl(NamespaceAliasDecl *D) {
1136   VisitRedeclarable(D);
1137   VisitNamedDecl(D);
1138   Record.AddSourceLocation(D->getNamespaceLoc());
1139   Record.AddSourceLocation(D->getTargetNameLoc());
1140   Record.AddNestedNameSpecifierLoc(D->getQualifierLoc());
1141   Record.AddDeclRef(D->getNamespace());
1142   Code = serialization::DECL_NAMESPACE_ALIAS;
1143 }
1144
1145 void ASTDeclWriter::VisitUsingDecl(UsingDecl *D) {
1146   VisitNamedDecl(D);
1147   Record.AddSourceLocation(D->getUsingLoc());
1148   Record.AddNestedNameSpecifierLoc(D->getQualifierLoc());
1149   Record.AddDeclarationNameLoc(D->DNLoc, D->getDeclName());
1150   Record.AddDeclRef(D->FirstUsingShadow.getPointer());
1151   Record.push_back(D->hasTypename());
1152   Record.AddDeclRef(Context.getInstantiatedFromUsingDecl(D));
1153   Code = serialization::DECL_USING;
1154 }
1155
1156 void ASTDeclWriter::VisitUsingPackDecl(UsingPackDecl *D) {
1157   Record.push_back(D->NumExpansions);
1158   VisitNamedDecl(D);
1159   Record.AddDeclRef(D->getInstantiatedFromUsingDecl());
1160   for (auto *E : D->expansions())
1161     Record.AddDeclRef(E);
1162   Code = serialization::DECL_USING_PACK;
1163 }
1164
1165 void ASTDeclWriter::VisitUsingShadowDecl(UsingShadowDecl *D) {
1166   VisitRedeclarable(D);
1167   VisitNamedDecl(D);
1168   Record.AddDeclRef(D->getTargetDecl());
1169   Record.AddDeclRef(D->UsingOrNextShadow);
1170   Record.AddDeclRef(Context.getInstantiatedFromUsingShadowDecl(D));
1171   Code = serialization::DECL_USING_SHADOW;
1172 }
1173
1174 void ASTDeclWriter::VisitConstructorUsingShadowDecl(
1175     ConstructorUsingShadowDecl *D) {
1176   VisitUsingShadowDecl(D);
1177   Record.AddDeclRef(D->NominatedBaseClassShadowDecl);
1178   Record.AddDeclRef(D->ConstructedBaseClassShadowDecl);
1179   Record.push_back(D->IsVirtual);
1180   Code = serialization::DECL_CONSTRUCTOR_USING_SHADOW;
1181 }
1182
1183 void ASTDeclWriter::VisitUsingDirectiveDecl(UsingDirectiveDecl *D) {
1184   VisitNamedDecl(D);
1185   Record.AddSourceLocation(D->getUsingLoc());
1186   Record.AddSourceLocation(D->getNamespaceKeyLocation());
1187   Record.AddNestedNameSpecifierLoc(D->getQualifierLoc());
1188   Record.AddDeclRef(D->getNominatedNamespace());
1189   Record.AddDeclRef(dyn_cast<Decl>(D->getCommonAncestor()));
1190   Code = serialization::DECL_USING_DIRECTIVE;
1191 }
1192
1193 void ASTDeclWriter::VisitUnresolvedUsingValueDecl(UnresolvedUsingValueDecl *D) {
1194   VisitValueDecl(D);
1195   Record.AddSourceLocation(D->getUsingLoc());
1196   Record.AddNestedNameSpecifierLoc(D->getQualifierLoc());
1197   Record.AddDeclarationNameLoc(D->DNLoc, D->getDeclName());
1198   Record.AddSourceLocation(D->getEllipsisLoc());
1199   Code = serialization::DECL_UNRESOLVED_USING_VALUE;
1200 }
1201
1202 void ASTDeclWriter::VisitUnresolvedUsingTypenameDecl(
1203                                                UnresolvedUsingTypenameDecl *D) {
1204   VisitTypeDecl(D);
1205   Record.AddSourceLocation(D->getTypenameLoc());
1206   Record.AddNestedNameSpecifierLoc(D->getQualifierLoc());
1207   Record.AddSourceLocation(D->getEllipsisLoc());
1208   Code = serialization::DECL_UNRESOLVED_USING_TYPENAME;
1209 }
1210
1211 void ASTDeclWriter::VisitCXXRecordDecl(CXXRecordDecl *D) {
1212   VisitRecordDecl(D);
1213
1214   enum {
1215     CXXRecNotTemplate = 0, CXXRecTemplate, CXXRecMemberSpecialization
1216   };
1217   if (ClassTemplateDecl *TemplD = D->getDescribedClassTemplate()) {
1218     Record.push_back(CXXRecTemplate);
1219     Record.AddDeclRef(TemplD);
1220   } else if (MemberSpecializationInfo *MSInfo
1221                = D->getMemberSpecializationInfo()) {
1222     Record.push_back(CXXRecMemberSpecialization);
1223     Record.AddDeclRef(MSInfo->getInstantiatedFrom());
1224     Record.push_back(MSInfo->getTemplateSpecializationKind());
1225     Record.AddSourceLocation(MSInfo->getPointOfInstantiation());
1226   } else {
1227     Record.push_back(CXXRecNotTemplate);
1228   }
1229
1230   Record.push_back(D->isThisDeclarationADefinition());
1231   if (D->isThisDeclarationADefinition())
1232     Record.AddCXXDefinitionData(D);
1233
1234   // Store (what we currently believe to be) the key function to avoid
1235   // deserializing every method so we can compute it.
1236   if (D->IsCompleteDefinition)
1237     Record.AddDeclRef(Context.getCurrentKeyFunction(D));
1238
1239   Code = serialization::DECL_CXX_RECORD;
1240 }
1241
1242 void ASTDeclWriter::VisitCXXMethodDecl(CXXMethodDecl *D) {
1243   VisitFunctionDecl(D);
1244   if (D->isCanonicalDecl()) {
1245     Record.push_back(D->size_overridden_methods());
1246     for (CXXMethodDecl::method_iterator
1247            I = D->begin_overridden_methods(), E = D->end_overridden_methods();
1248            I != E; ++I)
1249       Record.AddDeclRef(*I);
1250   } else {
1251     // We only need to record overridden methods once for the canonical decl.
1252     Record.push_back(0);
1253   }
1254
1255   if (D->getDeclContext() == D->getLexicalDeclContext() &&
1256       D->getFirstDecl() == D->getMostRecentDecl() &&
1257       !D->isInvalidDecl() &&
1258       !D->hasAttrs() &&
1259       !D->isTopLevelDeclInObjCContainer() &&
1260       D->getDeclName().getNameKind() == DeclarationName::Identifier &&
1261       !D->hasExtInfo() &&
1262       !D->hasInheritedPrototype() &&
1263       D->hasWrittenPrototype())
1264     AbbrevToUse = Writer.getDeclCXXMethodAbbrev();
1265
1266   Code = serialization::DECL_CXX_METHOD;
1267 }
1268
1269 void ASTDeclWriter::VisitCXXConstructorDecl(CXXConstructorDecl *D) {
1270   if (auto Inherited = D->getInheritedConstructor()) {
1271     Record.AddDeclRef(Inherited.getShadowDecl());
1272     Record.AddDeclRef(Inherited.getConstructor());
1273     Code = serialization::DECL_CXX_INHERITED_CONSTRUCTOR;
1274   } else {
1275     Code = serialization::DECL_CXX_CONSTRUCTOR;
1276   }
1277
1278   VisitCXXMethodDecl(D);
1279
1280   Code = D->isInheritingConstructor()
1281              ? serialization::DECL_CXX_INHERITED_CONSTRUCTOR
1282              : serialization::DECL_CXX_CONSTRUCTOR;
1283 }
1284
1285 void ASTDeclWriter::VisitCXXDestructorDecl(CXXDestructorDecl *D) {
1286   VisitCXXMethodDecl(D);
1287
1288   Record.AddDeclRef(D->getOperatorDelete());
1289
1290   Code = serialization::DECL_CXX_DESTRUCTOR;
1291 }
1292
1293 void ASTDeclWriter::VisitCXXConversionDecl(CXXConversionDecl *D) {
1294   VisitCXXMethodDecl(D);
1295   Code = serialization::DECL_CXX_CONVERSION;
1296 }
1297
1298 void ASTDeclWriter::VisitImportDecl(ImportDecl *D) {
1299   VisitDecl(D);
1300   Record.push_back(Writer.getSubmoduleID(D->getImportedModule()));
1301   ArrayRef<SourceLocation> IdentifierLocs = D->getIdentifierLocs();
1302   Record.push_back(!IdentifierLocs.empty());
1303   if (IdentifierLocs.empty()) {
1304     Record.AddSourceLocation(D->getLocEnd());
1305     Record.push_back(1);
1306   } else {
1307     for (unsigned I = 0, N = IdentifierLocs.size(); I != N; ++I)
1308       Record.AddSourceLocation(IdentifierLocs[I]);
1309     Record.push_back(IdentifierLocs.size());
1310   }
1311   // Note: the number of source locations must always be the last element in
1312   // the record.
1313   Code = serialization::DECL_IMPORT;
1314 }
1315
1316 void ASTDeclWriter::VisitAccessSpecDecl(AccessSpecDecl *D) {
1317   VisitDecl(D);
1318   Record.AddSourceLocation(D->getColonLoc());
1319   Code = serialization::DECL_ACCESS_SPEC;
1320 }
1321
1322 void ASTDeclWriter::VisitFriendDecl(FriendDecl *D) {
1323   // Record the number of friend type template parameter lists here
1324   // so as to simplify memory allocation during deserialization.
1325   Record.push_back(D->NumTPLists);
1326   VisitDecl(D);
1327   bool hasFriendDecl = D->Friend.is<NamedDecl*>();
1328   Record.push_back(hasFriendDecl);
1329   if (hasFriendDecl)
1330     Record.AddDeclRef(D->getFriendDecl());
1331   else
1332     Record.AddTypeSourceInfo(D->getFriendType());
1333   for (unsigned i = 0; i < D->NumTPLists; ++i)
1334     Record.AddTemplateParameterList(D->getFriendTypeTemplateParameterList(i));
1335   Record.AddDeclRef(D->getNextFriend());
1336   Record.push_back(D->UnsupportedFriend);
1337   Record.AddSourceLocation(D->FriendLoc);
1338   Code = serialization::DECL_FRIEND;
1339 }
1340
1341 void ASTDeclWriter::VisitFriendTemplateDecl(FriendTemplateDecl *D) {
1342   VisitDecl(D);
1343   Record.push_back(D->getNumTemplateParameters());
1344   for (unsigned i = 0, e = D->getNumTemplateParameters(); i != e; ++i)
1345     Record.AddTemplateParameterList(D->getTemplateParameterList(i));
1346   Record.push_back(D->getFriendDecl() != nullptr);
1347   if (D->getFriendDecl())
1348     Record.AddDeclRef(D->getFriendDecl());
1349   else
1350     Record.AddTypeSourceInfo(D->getFriendType());
1351   Record.AddSourceLocation(D->getFriendLoc());
1352   Code = serialization::DECL_FRIEND_TEMPLATE;
1353 }
1354
1355 void ASTDeclWriter::VisitTemplateDecl(TemplateDecl *D) {
1356   VisitNamedDecl(D);
1357
1358   Record.AddDeclRef(D->getTemplatedDecl());
1359   Record.AddTemplateParameterList(D->getTemplateParameters());
1360 }
1361
1362 void ASTDeclWriter::VisitRedeclarableTemplateDecl(RedeclarableTemplateDecl *D) {
1363   VisitRedeclarable(D);
1364
1365   // Emit data to initialize CommonOrPrev before VisitTemplateDecl so that
1366   // getCommonPtr() can be used while this is still initializing.
1367   if (D->isFirstDecl()) {
1368     // This declaration owns the 'common' pointer, so serialize that data now.
1369     Record.AddDeclRef(D->getInstantiatedFromMemberTemplate());
1370     if (D->getInstantiatedFromMemberTemplate())
1371       Record.push_back(D->isMemberSpecialization());
1372   }
1373
1374   VisitTemplateDecl(D);
1375   Record.push_back(D->getIdentifierNamespace());
1376 }
1377
1378 void ASTDeclWriter::VisitClassTemplateDecl(ClassTemplateDecl *D) {
1379   VisitRedeclarableTemplateDecl(D);
1380
1381   if (D->isFirstDecl())
1382     AddTemplateSpecializations(D);
1383   Code = serialization::DECL_CLASS_TEMPLATE;
1384 }
1385
1386 void ASTDeclWriter::VisitClassTemplateSpecializationDecl(
1387                                            ClassTemplateSpecializationDecl *D) {
1388   RegisterTemplateSpecialization(D->getSpecializedTemplate(), D);
1389
1390   VisitCXXRecordDecl(D);
1391
1392   llvm::PointerUnion<ClassTemplateDecl *,
1393                      ClassTemplatePartialSpecializationDecl *> InstFrom
1394     = D->getSpecializedTemplateOrPartial();
1395   if (Decl *InstFromD = InstFrom.dyn_cast<ClassTemplateDecl *>()) {
1396     Record.AddDeclRef(InstFromD);
1397   } else {
1398     Record.AddDeclRef(InstFrom.get<ClassTemplatePartialSpecializationDecl *>());
1399     Record.AddTemplateArgumentList(&D->getTemplateInstantiationArgs());
1400   }
1401
1402   Record.AddTemplateArgumentList(&D->getTemplateArgs());
1403   Record.AddSourceLocation(D->getPointOfInstantiation());
1404   Record.push_back(D->getSpecializationKind());
1405   Record.push_back(D->isCanonicalDecl());
1406
1407   if (D->isCanonicalDecl()) {
1408     // When reading, we'll add it to the folding set of the following template.
1409     Record.AddDeclRef(D->getSpecializedTemplate()->getCanonicalDecl());
1410   }
1411
1412   // Explicit info.
1413   Record.AddTypeSourceInfo(D->getTypeAsWritten());
1414   if (D->getTypeAsWritten()) {
1415     Record.AddSourceLocation(D->getExternLoc());
1416     Record.AddSourceLocation(D->getTemplateKeywordLoc());
1417   }
1418
1419   Code = serialization::DECL_CLASS_TEMPLATE_SPECIALIZATION;
1420 }
1421
1422 void ASTDeclWriter::VisitClassTemplatePartialSpecializationDecl(
1423                                     ClassTemplatePartialSpecializationDecl *D) {
1424   VisitClassTemplateSpecializationDecl(D);
1425
1426   Record.AddTemplateParameterList(D->getTemplateParameters());
1427   Record.AddASTTemplateArgumentListInfo(D->getTemplateArgsAsWritten());
1428
1429   // These are read/set from/to the first declaration.
1430   if (D->getPreviousDecl() == nullptr) {
1431     Record.AddDeclRef(D->getInstantiatedFromMember());
1432     Record.push_back(D->isMemberSpecialization());
1433   }
1434
1435   Code = serialization::DECL_CLASS_TEMPLATE_PARTIAL_SPECIALIZATION;
1436 }
1437
1438 void ASTDeclWriter::VisitVarTemplateDecl(VarTemplateDecl *D) {
1439   VisitRedeclarableTemplateDecl(D);
1440
1441   if (D->isFirstDecl())
1442     AddTemplateSpecializations(D);
1443   Code = serialization::DECL_VAR_TEMPLATE;
1444 }
1445
1446 void ASTDeclWriter::VisitVarTemplateSpecializationDecl(
1447     VarTemplateSpecializationDecl *D) {
1448   RegisterTemplateSpecialization(D->getSpecializedTemplate(), D);
1449
1450   VisitVarDecl(D);
1451
1452   llvm::PointerUnion<VarTemplateDecl *, VarTemplatePartialSpecializationDecl *>
1453   InstFrom = D->getSpecializedTemplateOrPartial();
1454   if (Decl *InstFromD = InstFrom.dyn_cast<VarTemplateDecl *>()) {
1455     Record.AddDeclRef(InstFromD);
1456   } else {
1457     Record.AddDeclRef(InstFrom.get<VarTemplatePartialSpecializationDecl *>());
1458     Record.AddTemplateArgumentList(&D->getTemplateInstantiationArgs());
1459   }
1460
1461   // Explicit info.
1462   Record.AddTypeSourceInfo(D->getTypeAsWritten());
1463   if (D->getTypeAsWritten()) {
1464     Record.AddSourceLocation(D->getExternLoc());
1465     Record.AddSourceLocation(D->getTemplateKeywordLoc());
1466   }
1467
1468   Record.AddTemplateArgumentList(&D->getTemplateArgs());
1469   Record.AddSourceLocation(D->getPointOfInstantiation());
1470   Record.push_back(D->getSpecializationKind());
1471   Record.push_back(D->isCanonicalDecl());
1472
1473   if (D->isCanonicalDecl()) {
1474     // When reading, we'll add it to the folding set of the following template.
1475     Record.AddDeclRef(D->getSpecializedTemplate()->getCanonicalDecl());
1476   }
1477
1478   Code = serialization::DECL_VAR_TEMPLATE_SPECIALIZATION;
1479 }
1480
1481 void ASTDeclWriter::VisitVarTemplatePartialSpecializationDecl(
1482     VarTemplatePartialSpecializationDecl *D) {
1483   VisitVarTemplateSpecializationDecl(D);
1484
1485   Record.AddTemplateParameterList(D->getTemplateParameters());
1486   Record.AddASTTemplateArgumentListInfo(D->getTemplateArgsAsWritten());
1487
1488   // These are read/set from/to the first declaration.
1489   if (D->getPreviousDecl() == nullptr) {
1490     Record.AddDeclRef(D->getInstantiatedFromMember());
1491     Record.push_back(D->isMemberSpecialization());
1492   }
1493
1494   Code = serialization::DECL_VAR_TEMPLATE_PARTIAL_SPECIALIZATION;
1495 }
1496
1497 void ASTDeclWriter::VisitClassScopeFunctionSpecializationDecl(
1498                                     ClassScopeFunctionSpecializationDecl *D) {
1499   VisitDecl(D);
1500   Record.AddDeclRef(D->getSpecialization());
1501   Code = serialization::DECL_CLASS_SCOPE_FUNCTION_SPECIALIZATION;
1502 }
1503
1504
1505 void ASTDeclWriter::VisitFunctionTemplateDecl(FunctionTemplateDecl *D) {
1506   VisitRedeclarableTemplateDecl(D);
1507
1508   if (D->isFirstDecl())
1509     AddTemplateSpecializations(D);
1510   Code = serialization::DECL_FUNCTION_TEMPLATE;
1511 }
1512
1513 void ASTDeclWriter::VisitTemplateTypeParmDecl(TemplateTypeParmDecl *D) {
1514   VisitTypeDecl(D);
1515
1516   Record.push_back(D->wasDeclaredWithTypename());
1517
1518   bool OwnsDefaultArg = D->hasDefaultArgument() &&
1519                         !D->defaultArgumentWasInherited();
1520   Record.push_back(OwnsDefaultArg);
1521   if (OwnsDefaultArg)
1522     Record.AddTypeSourceInfo(D->getDefaultArgumentInfo());
1523
1524   Code = serialization::DECL_TEMPLATE_TYPE_PARM;
1525 }
1526
1527 void ASTDeclWriter::VisitNonTypeTemplateParmDecl(NonTypeTemplateParmDecl *D) {
1528   // For an expanded parameter pack, record the number of expansion types here
1529   // so that it's easier for deserialization to allocate the right amount of
1530   // memory.
1531   if (D->isExpandedParameterPack())
1532     Record.push_back(D->getNumExpansionTypes());
1533
1534   VisitDeclaratorDecl(D);
1535   // TemplateParmPosition.
1536   Record.push_back(D->getDepth());
1537   Record.push_back(D->getPosition());
1538
1539   if (D->isExpandedParameterPack()) {
1540     for (unsigned I = 0, N = D->getNumExpansionTypes(); I != N; ++I) {
1541       Record.AddTypeRef(D->getExpansionType(I));
1542       Record.AddTypeSourceInfo(D->getExpansionTypeSourceInfo(I));
1543     }
1544
1545     Code = serialization::DECL_EXPANDED_NON_TYPE_TEMPLATE_PARM_PACK;
1546   } else {
1547     // Rest of NonTypeTemplateParmDecl.
1548     Record.push_back(D->isParameterPack());
1549     bool OwnsDefaultArg = D->hasDefaultArgument() &&
1550                           !D->defaultArgumentWasInherited();
1551     Record.push_back(OwnsDefaultArg);
1552     if (OwnsDefaultArg)
1553       Record.AddStmt(D->getDefaultArgument());
1554     Code = serialization::DECL_NON_TYPE_TEMPLATE_PARM;
1555   }
1556 }
1557
1558 void ASTDeclWriter::VisitTemplateTemplateParmDecl(TemplateTemplateParmDecl *D) {
1559   // For an expanded parameter pack, record the number of expansion types here
1560   // so that it's easier for deserialization to allocate the right amount of
1561   // memory.
1562   if (D->isExpandedParameterPack())
1563     Record.push_back(D->getNumExpansionTemplateParameters());
1564
1565   VisitTemplateDecl(D);
1566   // TemplateParmPosition.
1567   Record.push_back(D->getDepth());
1568   Record.push_back(D->getPosition());
1569
1570   if (D->isExpandedParameterPack()) {
1571     for (unsigned I = 0, N = D->getNumExpansionTemplateParameters();
1572          I != N; ++I)
1573       Record.AddTemplateParameterList(D->getExpansionTemplateParameters(I));
1574     Code = serialization::DECL_EXPANDED_TEMPLATE_TEMPLATE_PARM_PACK;
1575   } else {
1576     // Rest of TemplateTemplateParmDecl.
1577     Record.push_back(D->isParameterPack());
1578     bool OwnsDefaultArg = D->hasDefaultArgument() &&
1579                           !D->defaultArgumentWasInherited();
1580     Record.push_back(OwnsDefaultArg);
1581     if (OwnsDefaultArg)
1582       Record.AddTemplateArgumentLoc(D->getDefaultArgument());
1583     Code = serialization::DECL_TEMPLATE_TEMPLATE_PARM;
1584   }
1585 }
1586
1587 void ASTDeclWriter::VisitTypeAliasTemplateDecl(TypeAliasTemplateDecl *D) {
1588   VisitRedeclarableTemplateDecl(D);
1589   Code = serialization::DECL_TYPE_ALIAS_TEMPLATE;
1590 }
1591
1592 void ASTDeclWriter::VisitStaticAssertDecl(StaticAssertDecl *D) {
1593   VisitDecl(D);
1594   Record.AddStmt(D->getAssertExpr());
1595   Record.push_back(D->isFailed());
1596   Record.AddStmt(D->getMessage());
1597   Record.AddSourceLocation(D->getRParenLoc());
1598   Code = serialization::DECL_STATIC_ASSERT;
1599 }
1600
1601 /// \brief Emit the DeclContext part of a declaration context decl.
1602 void ASTDeclWriter::VisitDeclContext(DeclContext *DC) {
1603   Record.AddOffset(Writer.WriteDeclContextLexicalBlock(Context, DC));
1604   Record.AddOffset(Writer.WriteDeclContextVisibleBlock(Context, DC));
1605 }
1606
1607 const Decl *ASTWriter::getFirstLocalDecl(const Decl *D) {
1608   assert(IsLocalDecl(D) && "expected a local declaration");
1609
1610   const Decl *Canon = D->getCanonicalDecl();
1611   if (IsLocalDecl(Canon))
1612     return Canon;
1613
1614   const Decl *&CacheEntry = FirstLocalDeclCache[Canon];
1615   if (CacheEntry)
1616     return CacheEntry;
1617
1618   for (const Decl *Redecl = D; Redecl; Redecl = Redecl->getPreviousDecl())
1619     if (IsLocalDecl(Redecl))
1620       D = Redecl;
1621   return CacheEntry = D;
1622 }
1623
1624 template <typename T>
1625 void ASTDeclWriter::VisitRedeclarable(Redeclarable<T> *D) {
1626   T *First = D->getFirstDecl();
1627   T *MostRecent = First->getMostRecentDecl();
1628   T *DAsT = static_cast<T *>(D);
1629   if (MostRecent != First) {
1630     assert(isRedeclarableDeclKind(DAsT->getKind()) &&
1631            "Not considered redeclarable?");
1632
1633     Record.AddDeclRef(First);
1634
1635     // Write out a list of local redeclarations of this declaration if it's the
1636     // first local declaration in the chain.
1637     const Decl *FirstLocal = Writer.getFirstLocalDecl(DAsT);
1638     if (DAsT == FirstLocal) {
1639       // Emit a list of all imported first declarations so that we can be sure
1640       // that all redeclarations visible to this module are before D in the
1641       // redecl chain.
1642       unsigned I = Record.size();
1643       Record.push_back(0);
1644       if (Writer.Chain)
1645         AddFirstDeclFromEachModule(DAsT, /*IncludeLocal*/false);
1646       // This is the number of imported first declarations + 1.
1647       Record[I] = Record.size() - I;
1648
1649       // Collect the set of local redeclarations of this declaration, from
1650       // newest to oldest.
1651       ASTWriter::RecordData LocalRedecls;
1652       ASTRecordWriter LocalRedeclWriter(Record, LocalRedecls);
1653       for (const Decl *Prev = FirstLocal->getMostRecentDecl();
1654            Prev != FirstLocal; Prev = Prev->getPreviousDecl())
1655         if (!Prev->isFromASTFile())
1656           LocalRedeclWriter.AddDeclRef(Prev);
1657
1658       // If we have any redecls, write them now as a separate record preceding
1659       // the declaration itself.
1660       if (LocalRedecls.empty())
1661         Record.push_back(0);
1662       else
1663         Record.AddOffset(LocalRedeclWriter.Emit(LOCAL_REDECLARATIONS));
1664     } else {
1665       Record.push_back(0);
1666       Record.AddDeclRef(FirstLocal);
1667     }
1668
1669     // Make sure that we serialize both the previous and the most-recent
1670     // declarations, which (transitively) ensures that all declarations in the
1671     // chain get serialized.
1672     //
1673     // FIXME: This is not correct; when we reach an imported declaration we
1674     // won't emit its previous declaration.
1675     (void)Writer.GetDeclRef(D->getPreviousDecl());
1676     (void)Writer.GetDeclRef(MostRecent);
1677   } else {
1678     // We use the sentinel value 0 to indicate an only declaration.
1679     Record.push_back(0);
1680   }
1681 }
1682
1683 void ASTDeclWriter::VisitOMPThreadPrivateDecl(OMPThreadPrivateDecl *D) {
1684   Record.push_back(D->varlist_size());
1685   VisitDecl(D);
1686   for (auto *I : D->varlists())
1687     Record.AddStmt(I);
1688   Code = serialization::DECL_OMP_THREADPRIVATE;
1689 }
1690
1691 void ASTDeclWriter::VisitOMPDeclareReductionDecl(OMPDeclareReductionDecl *D) {
1692   VisitValueDecl(D);
1693   Record.AddSourceLocation(D->getLocStart());
1694   Record.AddStmt(D->getCombiner());
1695   Record.AddStmt(D->getInitializer());
1696   Record.AddDeclRef(D->getPrevDeclInScope());
1697   Code = serialization::DECL_OMP_DECLARE_REDUCTION;
1698 }
1699
1700 void ASTDeclWriter::VisitOMPCapturedExprDecl(OMPCapturedExprDecl *D) {
1701   VisitVarDecl(D);
1702   Code = serialization::DECL_OMP_CAPTUREDEXPR;
1703 }
1704
1705 //===----------------------------------------------------------------------===//
1706 // ASTWriter Implementation
1707 //===----------------------------------------------------------------------===//
1708
1709 void ASTWriter::WriteDeclAbbrevs() {
1710   using namespace llvm;
1711
1712   std::shared_ptr<BitCodeAbbrev> Abv;
1713
1714   // Abbreviation for DECL_FIELD
1715   Abv = std::make_shared<BitCodeAbbrev>();
1716   Abv->Add(BitCodeAbbrevOp(serialization::DECL_FIELD));
1717   // Decl
1718   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclContext
1719   Abv->Add(BitCodeAbbrevOp(0));                       // LexicalDeclContext
1720   Abv->Add(BitCodeAbbrevOp(0));                       // isInvalidDecl
1721   Abv->Add(BitCodeAbbrevOp(0));                       // HasAttrs
1722   Abv->Add(BitCodeAbbrevOp(0));                       // isImplicit
1723   Abv->Add(BitCodeAbbrevOp(0));                       // isUsed
1724   Abv->Add(BitCodeAbbrevOp(0));                       // isReferenced
1725   Abv->Add(BitCodeAbbrevOp(0));                   // TopLevelDeclInObjCContainer
1726   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2));  // AccessSpecifier
1727   Abv->Add(BitCodeAbbrevOp(0));                       // ModulePrivate
1728   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // SubmoduleID
1729   // NamedDecl
1730   Abv->Add(BitCodeAbbrevOp(0));                       // NameKind = Identifier
1731   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Name
1732   Abv->Add(BitCodeAbbrevOp(0));                       // AnonDeclNumber
1733   // ValueDecl
1734   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
1735   // DeclaratorDecl
1736   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // InnerStartLoc
1737   Abv->Add(BitCodeAbbrevOp(0));                       // hasExtInfo
1738   // FieldDecl
1739   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isMutable
1740   Abv->Add(BitCodeAbbrevOp(0));                       //getBitWidth
1741   // Type Source Info
1742   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1743   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1744   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // TypeLoc
1745   DeclFieldAbbrev = Stream.EmitAbbrev(std::move(Abv));
1746
1747   // Abbreviation for DECL_OBJC_IVAR
1748   Abv = std::make_shared<BitCodeAbbrev>();
1749   Abv->Add(BitCodeAbbrevOp(serialization::DECL_OBJC_IVAR));
1750   // Decl
1751   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclContext
1752   Abv->Add(BitCodeAbbrevOp(0));                       // LexicalDeclContext
1753   Abv->Add(BitCodeAbbrevOp(0));                       // isInvalidDecl
1754   Abv->Add(BitCodeAbbrevOp(0));                       // HasAttrs
1755   Abv->Add(BitCodeAbbrevOp(0));                       // isImplicit
1756   Abv->Add(BitCodeAbbrevOp(0));                       // isUsed
1757   Abv->Add(BitCodeAbbrevOp(0));                       // isReferenced
1758   Abv->Add(BitCodeAbbrevOp(0));                   // TopLevelDeclInObjCContainer
1759   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2));  // AccessSpecifier
1760   Abv->Add(BitCodeAbbrevOp(0));                       // ModulePrivate
1761   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // SubmoduleID
1762   // NamedDecl
1763   Abv->Add(BitCodeAbbrevOp(0));                       // NameKind = Identifier
1764   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Name
1765   Abv->Add(BitCodeAbbrevOp(0));                       // AnonDeclNumber
1766   // ValueDecl
1767   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
1768   // DeclaratorDecl
1769   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // InnerStartLoc
1770   Abv->Add(BitCodeAbbrevOp(0));                       // hasExtInfo
1771   // FieldDecl
1772   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isMutable
1773   Abv->Add(BitCodeAbbrevOp(0));                       //getBitWidth
1774   // ObjC Ivar
1775   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // getAccessControl
1776   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // getSynthesize
1777   // Type Source Info
1778   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1779   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1780   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // TypeLoc
1781   DeclObjCIvarAbbrev = Stream.EmitAbbrev(std::move(Abv));
1782
1783   // Abbreviation for DECL_ENUM
1784   Abv = std::make_shared<BitCodeAbbrev>();
1785   Abv->Add(BitCodeAbbrevOp(serialization::DECL_ENUM));
1786   // Redeclarable
1787   Abv->Add(BitCodeAbbrevOp(0));                       // No redeclaration
1788   // Decl
1789   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclContext
1790   Abv->Add(BitCodeAbbrevOp(0));                       // LexicalDeclContext
1791   Abv->Add(BitCodeAbbrevOp(0));                       // isInvalidDecl
1792   Abv->Add(BitCodeAbbrevOp(0));                       // HasAttrs
1793   Abv->Add(BitCodeAbbrevOp(0));                       // isImplicit
1794   Abv->Add(BitCodeAbbrevOp(0));                       // isUsed
1795   Abv->Add(BitCodeAbbrevOp(0));                       // isReferenced
1796   Abv->Add(BitCodeAbbrevOp(0));                   // TopLevelDeclInObjCContainer
1797   Abv->Add(BitCodeAbbrevOp(AS_none));                 // C++ AccessSpecifier
1798   Abv->Add(BitCodeAbbrevOp(0));                       // ModulePrivate
1799   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // SubmoduleID
1800   // NamedDecl
1801   Abv->Add(BitCodeAbbrevOp(0));                       // NameKind = Identifier
1802   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Name
1803   Abv->Add(BitCodeAbbrevOp(0));                       // AnonDeclNumber
1804   // TypeDecl
1805   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Source Location
1806   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type Ref
1807   // TagDecl
1808   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // IdentifierNamespace
1809   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // getTagKind
1810   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isCompleteDefinition
1811   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // EmbeddedInDeclarator
1812   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsFreeStanding
1813   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsCompleteDefinitionRequired
1814   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // SourceLocation
1815   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // SourceLocation
1816   Abv->Add(BitCodeAbbrevOp(0));                         // ExtInfoKind
1817   // EnumDecl
1818   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // AddTypeRef
1819   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // IntegerType
1820   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // getPromotionType
1821   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // getNumPositiveBits
1822   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // getNumNegativeBits
1823   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isScoped
1824   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isScopedUsingClassTag
1825   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isFixed
1826   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // InstantiatedMembEnum
1827   // DC
1828   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // LexicalOffset
1829   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // VisibleOffset
1830   DeclEnumAbbrev = Stream.EmitAbbrev(std::move(Abv));
1831
1832   // Abbreviation for DECL_RECORD
1833   Abv = std::make_shared<BitCodeAbbrev>();
1834   Abv->Add(BitCodeAbbrevOp(serialization::DECL_RECORD));
1835   // Redeclarable
1836   Abv->Add(BitCodeAbbrevOp(0));                       // No redeclaration
1837   // Decl
1838   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclContext
1839   Abv->Add(BitCodeAbbrevOp(0));                       // LexicalDeclContext
1840   Abv->Add(BitCodeAbbrevOp(0));                       // isInvalidDecl
1841   Abv->Add(BitCodeAbbrevOp(0));                       // HasAttrs
1842   Abv->Add(BitCodeAbbrevOp(0));                       // isImplicit
1843   Abv->Add(BitCodeAbbrevOp(0));                       // isUsed
1844   Abv->Add(BitCodeAbbrevOp(0));                       // isReferenced
1845   Abv->Add(BitCodeAbbrevOp(0));                   // TopLevelDeclInObjCContainer
1846   Abv->Add(BitCodeAbbrevOp(AS_none));                 // C++ AccessSpecifier
1847   Abv->Add(BitCodeAbbrevOp(0));                       // ModulePrivate
1848   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // SubmoduleID
1849   // NamedDecl
1850   Abv->Add(BitCodeAbbrevOp(0));                       // NameKind = Identifier
1851   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Name
1852   Abv->Add(BitCodeAbbrevOp(0));                       // AnonDeclNumber
1853   // TypeDecl
1854   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Source Location
1855   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type Ref
1856   // TagDecl
1857   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // IdentifierNamespace
1858   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // getTagKind
1859   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isCompleteDefinition
1860   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // EmbeddedInDeclarator
1861   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsFreeStanding
1862   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsCompleteDefinitionRequired
1863   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // SourceLocation
1864   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // SourceLocation
1865   Abv->Add(BitCodeAbbrevOp(0));                         // ExtInfoKind
1866   // RecordDecl
1867   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // FlexibleArrayMember
1868   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // AnonymousStructUnion
1869   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // hasObjectMember
1870   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // hasVolatileMember
1871   // DC
1872   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // LexicalOffset
1873   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // VisibleOffset
1874   DeclRecordAbbrev = Stream.EmitAbbrev(std::move(Abv));
1875
1876   // Abbreviation for DECL_PARM_VAR
1877   Abv = std::make_shared<BitCodeAbbrev>();
1878   Abv->Add(BitCodeAbbrevOp(serialization::DECL_PARM_VAR));
1879   // Redeclarable
1880   Abv->Add(BitCodeAbbrevOp(0));                       // No redeclaration
1881   // Decl
1882   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclContext
1883   Abv->Add(BitCodeAbbrevOp(0));                       // LexicalDeclContext
1884   Abv->Add(BitCodeAbbrevOp(0));                       // isInvalidDecl
1885   Abv->Add(BitCodeAbbrevOp(0));                       // HasAttrs
1886   Abv->Add(BitCodeAbbrevOp(0));                       // isImplicit
1887   Abv->Add(BitCodeAbbrevOp(0));                       // isUsed
1888   Abv->Add(BitCodeAbbrevOp(0));                       // isReferenced
1889   Abv->Add(BitCodeAbbrevOp(0));                   // TopLevelDeclInObjCContainer
1890   Abv->Add(BitCodeAbbrevOp(AS_none));                 // C++ AccessSpecifier
1891   Abv->Add(BitCodeAbbrevOp(0));                       // ModulePrivate
1892   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // SubmoduleID
1893   // NamedDecl
1894   Abv->Add(BitCodeAbbrevOp(0));                       // NameKind = Identifier
1895   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Name
1896   Abv->Add(BitCodeAbbrevOp(0));                       // AnonDeclNumber
1897   // ValueDecl
1898   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
1899   // DeclaratorDecl
1900   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // InnerStartLoc
1901   Abv->Add(BitCodeAbbrevOp(0));                       // hasExtInfo
1902   // VarDecl
1903   Abv->Add(BitCodeAbbrevOp(0));                       // SClass
1904   Abv->Add(BitCodeAbbrevOp(0));                       // TSCSpec
1905   Abv->Add(BitCodeAbbrevOp(0));                       // InitStyle
1906   Abv->Add(BitCodeAbbrevOp(0));                       // Linkage
1907   Abv->Add(BitCodeAbbrevOp(0));                       // HasInit
1908   Abv->Add(BitCodeAbbrevOp(0));                   // HasMemberSpecializationInfo
1909   // ParmVarDecl
1910   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsObjCMethodParameter
1911   Abv->Add(BitCodeAbbrevOp(0));                       // ScopeDepth
1912   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // ScopeIndex
1913   Abv->Add(BitCodeAbbrevOp(0));                       // ObjCDeclQualifier
1914   Abv->Add(BitCodeAbbrevOp(0));                       // KNRPromoted
1915   Abv->Add(BitCodeAbbrevOp(0));                       // HasInheritedDefaultArg
1916   Abv->Add(BitCodeAbbrevOp(0));                   // HasUninstantiatedDefaultArg
1917   // Type Source Info
1918   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1919   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1920   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // TypeLoc
1921   DeclParmVarAbbrev = Stream.EmitAbbrev(std::move(Abv));
1922
1923   // Abbreviation for DECL_TYPEDEF
1924   Abv = std::make_shared<BitCodeAbbrev>();
1925   Abv->Add(BitCodeAbbrevOp(serialization::DECL_TYPEDEF));
1926   // Redeclarable
1927   Abv->Add(BitCodeAbbrevOp(0));                       // No redeclaration
1928   // Decl
1929   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclContext
1930   Abv->Add(BitCodeAbbrevOp(0));                       // LexicalDeclContext
1931   Abv->Add(BitCodeAbbrevOp(0));                       // isInvalidDecl
1932   Abv->Add(BitCodeAbbrevOp(0));                       // HasAttrs
1933   Abv->Add(BitCodeAbbrevOp(0));                       // isImplicit
1934   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isUsed
1935   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isReferenced
1936   Abv->Add(BitCodeAbbrevOp(0));                   // TopLevelDeclInObjCContainer
1937   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2)); // C++ AccessSpecifier
1938   Abv->Add(BitCodeAbbrevOp(0));                       // ModulePrivate
1939   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // SubmoduleID
1940   // NamedDecl
1941   Abv->Add(BitCodeAbbrevOp(0));                       // NameKind = Identifier
1942   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Name
1943   Abv->Add(BitCodeAbbrevOp(0));                       // AnonDeclNumber
1944   // TypeDecl
1945   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Source Location
1946   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type Ref
1947   // TypedefDecl
1948   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1949   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // TypeLoc
1950   DeclTypedefAbbrev = Stream.EmitAbbrev(std::move(Abv));
1951
1952   // Abbreviation for DECL_VAR
1953   Abv = std::make_shared<BitCodeAbbrev>();
1954   Abv->Add(BitCodeAbbrevOp(serialization::DECL_VAR));
1955   // Redeclarable
1956   Abv->Add(BitCodeAbbrevOp(0));                       // No redeclaration
1957   // Decl
1958   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclContext
1959   Abv->Add(BitCodeAbbrevOp(0));                       // LexicalDeclContext
1960   Abv->Add(BitCodeAbbrevOp(0));                       // isInvalidDecl
1961   Abv->Add(BitCodeAbbrevOp(0));                       // HasAttrs
1962   Abv->Add(BitCodeAbbrevOp(0));                       // isImplicit
1963   Abv->Add(BitCodeAbbrevOp(0));                       // isUsed
1964   Abv->Add(BitCodeAbbrevOp(0));                       // isReferenced
1965   Abv->Add(BitCodeAbbrevOp(0));                   // TopLevelDeclInObjCContainer
1966   Abv->Add(BitCodeAbbrevOp(AS_none));                 // C++ AccessSpecifier
1967   Abv->Add(BitCodeAbbrevOp(0));                       // ModulePrivate
1968   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // SubmoduleID
1969   // NamedDecl
1970   Abv->Add(BitCodeAbbrevOp(0));                       // NameKind = Identifier
1971   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Name
1972   Abv->Add(BitCodeAbbrevOp(0));                       // AnonDeclNumber
1973   // ValueDecl
1974   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
1975   // DeclaratorDecl
1976   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // InnerStartLoc
1977   Abv->Add(BitCodeAbbrevOp(0));                       // hasExtInfo
1978   // VarDecl
1979   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); // SClass
1980   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2)); // TSCSpec
1981   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2)); // InitStyle
1982   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsThisDeclarationADemotedDefinition
1983   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isExceptionVariable
1984   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isNRVOVariable
1985   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isCXXForRangeDecl
1986   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isARCPseudoStrong
1987   Abv->Add(BitCodeAbbrevOp(0));                         // isInline
1988   Abv->Add(BitCodeAbbrevOp(0));                         // isInlineSpecified
1989   Abv->Add(BitCodeAbbrevOp(0));                         // isConstexpr
1990   Abv->Add(BitCodeAbbrevOp(0));                         // isInitCapture
1991   Abv->Add(BitCodeAbbrevOp(0));                         // isPrevDeclInSameScope
1992   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); // Linkage
1993   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2)); // IsInitICE (local)
1994   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2)); // VarKind (local enum)
1995   // Type Source Info
1996   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1997   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1998   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // TypeLoc
1999   DeclVarAbbrev = Stream.EmitAbbrev(std::move(Abv));
2000
2001   // Abbreviation for DECL_CXX_METHOD
2002   Abv = std::make_shared<BitCodeAbbrev>();
2003   Abv->Add(BitCodeAbbrevOp(serialization::DECL_CXX_METHOD));
2004   // RedeclarableDecl
2005   Abv->Add(BitCodeAbbrevOp(0));                         // CanonicalDecl
2006   // Decl
2007   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // DeclContext
2008   Abv->Add(BitCodeAbbrevOp(0));                         // LexicalDeclContext
2009   Abv->Add(BitCodeAbbrevOp(0));                         // Invalid
2010   Abv->Add(BitCodeAbbrevOp(0));                         // HasAttrs
2011   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Implicit
2012   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Used
2013   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Referenced
2014   Abv->Add(BitCodeAbbrevOp(0));                         // InObjCContainer
2015   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2)); // Access
2016   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // ModulePrivate
2017   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // SubmoduleID
2018   // NamedDecl
2019   Abv->Add(BitCodeAbbrevOp(DeclarationName::Identifier)); // NameKind
2020   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // Identifier
2021   Abv->Add(BitCodeAbbrevOp(0));                         // AnonDeclNumber
2022   // ValueDecl
2023   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // Type
2024   // DeclaratorDecl
2025   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // InnerLocStart
2026   Abv->Add(BitCodeAbbrevOp(0));                         // HasExtInfo
2027   // FunctionDecl
2028   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 11)); // IDNS
2029   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); // StorageClass
2030   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Inline
2031   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // InlineSpecified
2032   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // ExplicitSpecified
2033   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // VirtualAsWritten
2034   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Pure
2035   Abv->Add(BitCodeAbbrevOp(0));                         // HasInheritedProto
2036   Abv->Add(BitCodeAbbrevOp(1));                         // HasWrittenProto
2037   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Deleted
2038   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Trivial
2039   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Defaulted
2040   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // ExplicitlyDefaulted
2041   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // ImplicitReturnZero
2042   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Constexpr
2043   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // UsesSEHTry
2044   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // SkippedBody
2045   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // LateParsed
2046   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); // Linkage
2047   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // LocEnd
2048   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); // TemplateKind
2049   // This Array slurps the rest of the record. Fortunately we want to encode
2050   // (nearly) all the remaining (variable number of) fields in the same way.
2051   //
2052   // This is the function template information if any, then
2053   //         NumParams and Params[] from FunctionDecl, and
2054   //         NumOverriddenMethods, OverriddenMethods[] from CXXMethodDecl.
2055   //
2056   //  Add an AbbrevOp for 'size then elements' and use it here.
2057   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2058   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
2059   DeclCXXMethodAbbrev = Stream.EmitAbbrev(std::move(Abv));
2060
2061   // Abbreviation for EXPR_DECL_REF
2062   Abv = std::make_shared<BitCodeAbbrev>();
2063   Abv->Add(BitCodeAbbrevOp(serialization::EXPR_DECL_REF));
2064   //Stmt
2065   //Expr
2066   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
2067   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //TypeDependent
2068   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //ValueDependent
2069   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //InstantiationDependent
2070   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //UnexpandedParamPack
2071   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetValueKind
2072   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetObjectKind
2073   //DeclRefExpr
2074   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //HasQualifier
2075   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //GetDeclFound
2076   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //ExplicitTemplateArgs
2077   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //HadMultipleCandidates
2078   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
2079                            1)); // RefersToEnclosingVariableOrCapture
2080   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclRef
2081   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Location
2082   DeclRefExprAbbrev = Stream.EmitAbbrev(std::move(Abv));
2083
2084   // Abbreviation for EXPR_INTEGER_LITERAL
2085   Abv = std::make_shared<BitCodeAbbrev>();
2086   Abv->Add(BitCodeAbbrevOp(serialization::EXPR_INTEGER_LITERAL));
2087   //Stmt
2088   //Expr
2089   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
2090   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //TypeDependent
2091   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //ValueDependent
2092   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //InstantiationDependent
2093   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //UnexpandedParamPack
2094   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetValueKind
2095   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetObjectKind
2096   //Integer Literal
2097   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Location
2098   Abv->Add(BitCodeAbbrevOp(32));                      // Bit Width
2099   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Value
2100   IntegerLiteralAbbrev = Stream.EmitAbbrev(std::move(Abv));
2101
2102   // Abbreviation for EXPR_CHARACTER_LITERAL
2103   Abv = std::make_shared<BitCodeAbbrev>();
2104   Abv->Add(BitCodeAbbrevOp(serialization::EXPR_CHARACTER_LITERAL));
2105   //Stmt
2106   //Expr
2107   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
2108   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //TypeDependent
2109   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //ValueDependent
2110   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //InstantiationDependent
2111   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //UnexpandedParamPack
2112   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetValueKind
2113   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetObjectKind
2114   //Character Literal
2115   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // getValue
2116   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Location
2117   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); // getKind
2118   CharacterLiteralAbbrev = Stream.EmitAbbrev(std::move(Abv));
2119
2120   // Abbreviation for EXPR_IMPLICIT_CAST
2121   Abv = std::make_shared<BitCodeAbbrev>();
2122   Abv->Add(BitCodeAbbrevOp(serialization::EXPR_IMPLICIT_CAST));
2123   // Stmt
2124   // Expr
2125   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
2126   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //TypeDependent
2127   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //ValueDependent
2128   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //InstantiationDependent
2129   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //UnexpandedParamPack
2130   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetValueKind
2131   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetObjectKind
2132   // CastExpr
2133   Abv->Add(BitCodeAbbrevOp(0)); // PathSize
2134   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 6)); // CastKind
2135   // ImplicitCastExpr
2136   ExprImplicitCastAbbrev = Stream.EmitAbbrev(std::move(Abv));
2137
2138   Abv = std::make_shared<BitCodeAbbrev>();
2139   Abv->Add(BitCodeAbbrevOp(serialization::DECL_CONTEXT_LEXICAL));
2140   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
2141   DeclContextLexicalAbbrev = Stream.EmitAbbrev(std::move(Abv));
2142
2143   Abv = std::make_shared<BitCodeAbbrev>();
2144   Abv->Add(BitCodeAbbrevOp(serialization::DECL_CONTEXT_VISIBLE));
2145   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
2146   DeclContextVisibleLookupAbbrev = Stream.EmitAbbrev(std::move(Abv));
2147 }
2148
2149 /// isRequiredDecl - Check if this is a "required" Decl, which must be seen by
2150 /// consumers of the AST.
2151 ///
2152 /// Such decls will always be deserialized from the AST file, so we would like
2153 /// this to be as restrictive as possible. Currently the predicate is driven by
2154 /// code generation requirements, if other clients have a different notion of
2155 /// what is "required" then we may have to consider an alternate scheme where
2156 /// clients can iterate over the top-level decls and get information on them,
2157 /// without necessary deserializing them. We could explicitly require such
2158 /// clients to use a separate API call to "realize" the decl. This should be
2159 /// relatively painless since they would presumably only do it for top-level
2160 /// decls.
2161 static bool isRequiredDecl(const Decl *D, ASTContext &Context,
2162                            bool WritingModule) {
2163   // An ObjCMethodDecl is never considered as "required" because its
2164   // implementation container always is.
2165
2166   // File scoped assembly or obj-c or OMP declare target implementation must be
2167   // seen.
2168   if (isa<FileScopeAsmDecl>(D) || isa<ObjCImplDecl>(D) ||
2169       D->hasAttr<OMPDeclareTargetDeclAttr>())
2170     return true;
2171
2172   if (WritingModule && (isa<VarDecl>(D) || isa<ImportDecl>(D))) {
2173     // These declarations are part of the module initializer, and are emitted
2174     // if and when the module is imported, rather than being emitted eagerly.
2175     return false;
2176   }
2177
2178   return Context.DeclMustBeEmitted(D);
2179 }
2180
2181 void ASTWriter::WriteDecl(ASTContext &Context, Decl *D) {
2182   // Determine the ID for this declaration.
2183   serialization::DeclID ID;
2184   assert(!D->isFromASTFile() && "should not be emitting imported decl");
2185   serialization::DeclID &IDR = DeclIDs[D];
2186   if (IDR == 0)
2187     IDR = NextDeclID++;
2188
2189   ID = IDR;
2190
2191   assert(ID >= FirstDeclID && "invalid decl ID");
2192
2193   RecordData Record;
2194   ASTDeclWriter W(*this, Context, Record);
2195
2196   // Build a record for this declaration
2197   W.Visit(D);
2198
2199   // Emit this declaration to the bitstream.
2200   uint64_t Offset = W.Emit(D);
2201
2202   // Record the offset for this declaration
2203   SourceLocation Loc = D->getLocation();
2204   unsigned Index = ID - FirstDeclID;
2205   if (DeclOffsets.size() == Index)
2206     DeclOffsets.push_back(DeclOffset(Loc, Offset));
2207   else if (DeclOffsets.size() < Index) {
2208     // FIXME: Can/should this happen?
2209     DeclOffsets.resize(Index+1);
2210     DeclOffsets[Index].setLocation(Loc);
2211     DeclOffsets[Index].BitOffset = Offset;
2212   } else {
2213     llvm_unreachable("declarations should be emitted in ID order");
2214   }
2215
2216   SourceManager &SM = Context.getSourceManager();
2217   if (Loc.isValid() && SM.isLocalSourceLocation(Loc))
2218     associateDeclWithFile(D, ID);
2219
2220   // Note declarations that should be deserialized eagerly so that we can add
2221   // them to a record in the AST file later.
2222   if (isRequiredDecl(D, Context, WritingModule))
2223     EagerlyDeserializedDecls.push_back(ID);
2224 }
2225
2226 void ASTRecordWriter::AddFunctionDefinition(const FunctionDecl *FD) {
2227   // Switch case IDs are per function body.
2228   Writer->ClearSwitchCaseIDs();
2229
2230   assert(FD->doesThisDeclarationHaveABody());
2231   bool ModulesCodegen = Writer->Context->getLangOpts().ModulesCodegen &&
2232                         Writer->WritingModule && !FD->isDependentContext();
2233   Record->push_back(ModulesCodegen);
2234   if (ModulesCodegen)
2235     Writer->ModularCodegenDecls.push_back(Writer->GetDeclRef(FD));
2236   if (auto *CD = dyn_cast<CXXConstructorDecl>(FD)) {
2237     Record->push_back(CD->getNumCtorInitializers());
2238     if (CD->getNumCtorInitializers())
2239       AddCXXCtorInitializers(
2240           llvm::makeArrayRef(CD->init_begin(), CD->init_end()));
2241   }
2242   AddStmt(FD->getBody());
2243 }