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     if (const auto *IPD = dyn_cast<ImplicitParamDecl>(D))
 919       Record.push_back(static_cast<unsigned>(IPD->getParameterKind()));
 920     else
 921       Record.push_back(0);
 922   }
 923   Record.push_back(D->getLinkageInternal());
 924
 925   if (D->getInit()) {
 926     Record.push_back(!D->isInitKnownICE() ? 1 : (D->isInitICE() ? 3 : 2));
 927     Record.AddStmt(D->getInit());
 928   } else {
 929     Record.push_back(0);
 930   }
 931
 932   enum {
 933     VarNotTemplate = 0, VarTemplate, StaticDataMemberSpecialization
 934   };
 935   if (VarTemplateDecl *TemplD = D->getDescribedVarTemplate()) {
 936     Record.push_back(VarTemplate);
 937     Record.AddDeclRef(TemplD);
 938   } else if (MemberSpecializationInfo *SpecInfo
 939                = D->getMemberSpecializationInfo()) {
 940     Record.push_back(StaticDataMemberSpecialization);
 941     Record.AddDeclRef(SpecInfo->getInstantiatedFrom());
 942     Record.push_back(SpecInfo->getTemplateSpecializationKind());
 943     Record.AddSourceLocation(SpecInfo->getPointOfInstantiation());
 944   } else {
 945     Record.push_back(VarNotTemplate);
 946   }
 947
 948   if (D->getDeclContext() == D->getLexicalDeclContext() &&
 949       !D->hasAttrs() &&
 950       !D->isImplicit() &&
 951       !D->isUsed(false) &&
 952       !D->isInvalidDecl() &&
 953       !D->isReferenced() &&
 954       !D->isTopLevelDeclInObjCContainer() &&
 955       D->getAccess() == AS_none &&
 956       !D->isModulePrivate() &&
 957       !needsAnonymousDeclarationNumber(D) &&
 958       D->getDeclName().getNameKind() == DeclarationName::Identifier &&
 959       !D->hasExtInfo() &&
 960       D->getFirstDecl() == D->getMostRecentDecl() &&
 961       D->getKind() == Decl::Var &&
 962       !D->isInline() &&
 963       !D->isConstexpr() &&
 964       !D->isInitCapture() &&
 965       !D->isPreviousDeclInSameBlockScope() &&
 966       !D->getMemberSpecializationInfo())
 967     AbbrevToUse = Writer.getDeclVarAbbrev();
 968
 969   Code = serialization::DECL_VAR;
 970 }
 971
 972 void ASTDeclWriter::VisitImplicitParamDecl(ImplicitParamDecl *D) {
 973   VisitVarDecl(D);
 974   Code = serialization::DECL_IMPLICIT_PARAM;
 975 }
 976
 977 void ASTDeclWriter::VisitParmVarDecl(ParmVarDecl *D) {
 978   VisitVarDecl(D);
 979   Record.push_back(D->isObjCMethodParameter());
 980   Record.push_back(D->getFunctionScopeDepth());
 981   Record.push_back(D->getFunctionScopeIndex());
 982   Record.push_back(D->getObjCDeclQualifier()); // FIXME: stable encoding
 983   Record.push_back(D->isKNRPromoted());
 984   Record.push_back(D->hasInheritedDefaultArg());
 985   Record.push_back(D->hasUninstantiatedDefaultArg());
 986   if (D->hasUninstantiatedDefaultArg())
 987     Record.AddStmt(D->getUninstantiatedDefaultArg());
 988   Code = serialization::DECL_PARM_VAR;
 989
 990   assert(!D->isARCPseudoStrong()); // can be true of ImplicitParamDecl
 991
 992   // If the assumptions about the DECL_PARM_VAR abbrev are true, use it.  Here
 993   // we dynamically check for the properties that we optimize for, but don't
 994   // know are true of all PARM_VAR_DECLs.
 995   if (D->getDeclContext() == D->getLexicalDeclContext() &&
 996       !D->hasAttrs() &&
 997       !D->hasExtInfo() &&
 998       !D->isImplicit() &&
 999       !D->isUsed(false) &&
1000       !D->isInvalidDecl() &&
1001       !D->isReferenced() &&
1002       D->getAccess() == AS_none &&
1003       !D->isModulePrivate() &&
1004       D->getStorageClass() == 0 &&
1005       D->getInitStyle() == VarDecl::CInit && // Can params have anything else?
1006       D->getFunctionScopeDepth() == 0 &&
1007       D->getObjCDeclQualifier() == 0 &&
1008       !D->isKNRPromoted() &&
1009       !D->hasInheritedDefaultArg() &&
1010       D->getInit() == nullptr &&
1011       !D->hasUninstantiatedDefaultArg())  // No default expr.
1012     AbbrevToUse = Writer.getDeclParmVarAbbrev();
1013
1014   // Check things we know are true of *every* PARM_VAR_DECL, which is more than
1015   // just us assuming it.
1016   assert(!D->getTSCSpec() && "PARM_VAR_DECL can't use TLS");
1017   assert(!D->isThisDeclarationADemotedDefinition()
1018          && "PARM_VAR_DECL can't be demoted definition.");
1019   assert(D->getAccess() == AS_none && "PARM_VAR_DECL can't be public/private");
1020   assert(!D->isExceptionVariable() && "PARM_VAR_DECL can't be exception var");
1021   assert(D->getPreviousDecl() == nullptr && "PARM_VAR_DECL can't be redecl");
1022   assert(!D->isStaticDataMember() &&
1023          "PARM_VAR_DECL can't be static data member");
1024 }
1025
1026 void ASTDeclWriter::VisitDecompositionDecl(DecompositionDecl *D) {
1027   // Record the number of bindings first to simplify deserialization.
1028   Record.push_back(D->bindings().size());
1029
1030   VisitVarDecl(D);
1031   for (auto *B : D->bindings())
1032     Record.AddDeclRef(B);
1033   Code = serialization::DECL_DECOMPOSITION;
1034 }
1035
1036 void ASTDeclWriter::VisitBindingDecl(BindingDecl *D) {
1037   VisitValueDecl(D);
1038   Record.AddStmt(D->getBinding());
1039   Code = serialization::DECL_BINDING;
1040 }
1041
1042 void ASTDeclWriter::VisitFileScopeAsmDecl(FileScopeAsmDecl *D) {
1043   VisitDecl(D);
1044   Record.AddStmt(D->getAsmString());
1045   Record.AddSourceLocation(D->getRParenLoc());
1046   Code = serialization::DECL_FILE_SCOPE_ASM;
1047 }
1048
1049 void ASTDeclWriter::VisitEmptyDecl(EmptyDecl *D) {
1050   VisitDecl(D);
1051   Code = serialization::DECL_EMPTY;
1052 }
1053
1054 void ASTDeclWriter::VisitBlockDecl(BlockDecl *D) {
1055   VisitDecl(D);
1056   Record.AddStmt(D->getBody());
1057   Record.AddTypeSourceInfo(D->getSignatureAsWritten());
1058   Record.push_back(D->param_size());
1059   for (ParmVarDecl *P : D->parameters())
1060     Record.AddDeclRef(P);
1061   Record.push_back(D->isVariadic());
1062   Record.push_back(D->blockMissingReturnType());
1063   Record.push_back(D->isConversionFromLambda());
1064   Record.push_back(D->capturesCXXThis());
1065   Record.push_back(D->getNumCaptures());
1066   for (const auto &capture : D->captures()) {
1067     Record.AddDeclRef(capture.getVariable());
1068
1069     unsigned flags = 0;
1070     if (capture.isByRef()) flags |= 1;
1071     if (capture.isNested()) flags |= 2;
1072     if (capture.hasCopyExpr()) flags |= 4;
1073     Record.push_back(flags);
1074
1075     if (capture.hasCopyExpr()) Record.AddStmt(capture.getCopyExpr());
1076   }
1077
1078   Code = serialization::DECL_BLOCK;
1079 }
1080
1081 void ASTDeclWriter::VisitCapturedDecl(CapturedDecl *CD) {
1082   Record.push_back(CD->getNumParams());
1083   VisitDecl(CD);
1084   Record.push_back(CD->getContextParamPosition());
1085   Record.push_back(CD->isNothrow() ? 1 : 0);
1086   // Body is stored by VisitCapturedStmt.
1087   for (unsigned I = 0; I < CD->getNumParams(); ++I)
1088     Record.AddDeclRef(CD->getParam(I));
1089   Code = serialization::DECL_CAPTURED;
1090 }
1091
1092 void ASTDeclWriter::VisitLinkageSpecDecl(LinkageSpecDecl *D) {
1093   VisitDecl(D);
1094   Record.push_back(D->getLanguage());
1095   Record.AddSourceLocation(D->getExternLoc());
1096   Record.AddSourceLocation(D->getRBraceLoc());
1097   Code = serialization::DECL_LINKAGE_SPEC;
1098 }
1099
1100 void ASTDeclWriter::VisitExportDecl(ExportDecl *D) {
1101   VisitDecl(D);
1102   Record.AddSourceLocation(D->getRBraceLoc());
1103   Code = serialization::DECL_EXPORT;
1104 }
1105
1106 void ASTDeclWriter::VisitLabelDecl(LabelDecl *D) {
1107   VisitNamedDecl(D);
1108   Record.AddSourceLocation(D->getLocStart());
1109   Code = serialization::DECL_LABEL;
1110 }
1111
1112
1113 void ASTDeclWriter::VisitNamespaceDecl(NamespaceDecl *D) {
1114   VisitRedeclarable(D);
1115   VisitNamedDecl(D);
1116   Record.push_back(D->isInline());
1117   Record.AddSourceLocation(D->getLocStart());
1118   Record.AddSourceLocation(D->getRBraceLoc());
1119
1120   if (D->isOriginalNamespace())
1121     Record.AddDeclRef(D->getAnonymousNamespace());
1122   Code = serialization::DECL_NAMESPACE;
1123
1124   if (Writer.hasChain() && D->isAnonymousNamespace() &&
1125       D == D->getMostRecentDecl()) {
1126     // This is a most recent reopening of the anonymous namespace. If its parent
1127     // is in a previous PCH (or is the TU), mark that parent for update, because
1128     // the original namespace always points to the latest re-opening of its
1129     // anonymous namespace.
1130     Decl *Parent = cast<Decl>(
1131         D->getParent()->getRedeclContext()->getPrimaryContext());
1132     if (Parent->isFromASTFile() || isa<TranslationUnitDecl>(Parent)) {
1133       Writer.DeclUpdates[Parent].push_back(
1134           ASTWriter::DeclUpdate(UPD_CXX_ADDED_ANONYMOUS_NAMESPACE, D));
1135     }
1136   }
1137 }
1138
1139 void ASTDeclWriter::VisitNamespaceAliasDecl(NamespaceAliasDecl *D) {
1140   VisitRedeclarable(D);
1141   VisitNamedDecl(D);
1142   Record.AddSourceLocation(D->getNamespaceLoc());
1143   Record.AddSourceLocation(D->getTargetNameLoc());
1144   Record.AddNestedNameSpecifierLoc(D->getQualifierLoc());
1145   Record.AddDeclRef(D->getNamespace());
1146   Code = serialization::DECL_NAMESPACE_ALIAS;
1147 }
1148
1149 void ASTDeclWriter::VisitUsingDecl(UsingDecl *D) {
1150   VisitNamedDecl(D);
1151   Record.AddSourceLocation(D->getUsingLoc());
1152   Record.AddNestedNameSpecifierLoc(D->getQualifierLoc());
1153   Record.AddDeclarationNameLoc(D->DNLoc, D->getDeclName());
1154   Record.AddDeclRef(D->FirstUsingShadow.getPointer());
1155   Record.push_back(D->hasTypename());
1156   Record.AddDeclRef(Context.getInstantiatedFromUsingDecl(D));
1157   Code = serialization::DECL_USING;
1158 }
1159
1160 void ASTDeclWriter::VisitUsingPackDecl(UsingPackDecl *D) {
1161   Record.push_back(D->NumExpansions);
1162   VisitNamedDecl(D);
1163   Record.AddDeclRef(D->getInstantiatedFromUsingDecl());
1164   for (auto *E : D->expansions())
1165     Record.AddDeclRef(E);
1166   Code = serialization::DECL_USING_PACK;
1167 }
1168
1169 void ASTDeclWriter::VisitUsingShadowDecl(UsingShadowDecl *D) {
1170   VisitRedeclarable(D);
1171   VisitNamedDecl(D);
1172   Record.AddDeclRef(D->getTargetDecl());
1173   Record.AddDeclRef(D->UsingOrNextShadow);
1174   Record.AddDeclRef(Context.getInstantiatedFromUsingShadowDecl(D));
1175   Code = serialization::DECL_USING_SHADOW;
1176 }
1177
1178 void ASTDeclWriter::VisitConstructorUsingShadowDecl(
1179     ConstructorUsingShadowDecl *D) {
1180   VisitUsingShadowDecl(D);
1181   Record.AddDeclRef(D->NominatedBaseClassShadowDecl);
1182   Record.AddDeclRef(D->ConstructedBaseClassShadowDecl);
1183   Record.push_back(D->IsVirtual);
1184   Code = serialization::DECL_CONSTRUCTOR_USING_SHADOW;
1185 }
1186
1187 void ASTDeclWriter::VisitUsingDirectiveDecl(UsingDirectiveDecl *D) {
1188   VisitNamedDecl(D);
1189   Record.AddSourceLocation(D->getUsingLoc());
1190   Record.AddSourceLocation(D->getNamespaceKeyLocation());
1191   Record.AddNestedNameSpecifierLoc(D->getQualifierLoc());
1192   Record.AddDeclRef(D->getNominatedNamespace());
1193   Record.AddDeclRef(dyn_cast<Decl>(D->getCommonAncestor()));
1194   Code = serialization::DECL_USING_DIRECTIVE;
1195 }
1196
1197 void ASTDeclWriter::VisitUnresolvedUsingValueDecl(UnresolvedUsingValueDecl *D) {
1198   VisitValueDecl(D);
1199   Record.AddSourceLocation(D->getUsingLoc());
1200   Record.AddNestedNameSpecifierLoc(D->getQualifierLoc());
1201   Record.AddDeclarationNameLoc(D->DNLoc, D->getDeclName());
1202   Record.AddSourceLocation(D->getEllipsisLoc());
1203   Code = serialization::DECL_UNRESOLVED_USING_VALUE;
1204 }
1205
1206 void ASTDeclWriter::VisitUnresolvedUsingTypenameDecl(
1207                                                UnresolvedUsingTypenameDecl *D) {
1208   VisitTypeDecl(D);
1209   Record.AddSourceLocation(D->getTypenameLoc());
1210   Record.AddNestedNameSpecifierLoc(D->getQualifierLoc());
1211   Record.AddSourceLocation(D->getEllipsisLoc());
1212   Code = serialization::DECL_UNRESOLVED_USING_TYPENAME;
1213 }
1214
1215 void ASTDeclWriter::VisitCXXRecordDecl(CXXRecordDecl *D) {
1216   VisitRecordDecl(D);
1217
1218   enum {
1219     CXXRecNotTemplate = 0, CXXRecTemplate, CXXRecMemberSpecialization
1220   };
1221   if (ClassTemplateDecl *TemplD = D->getDescribedClassTemplate()) {
1222     Record.push_back(CXXRecTemplate);
1223     Record.AddDeclRef(TemplD);
1224   } else if (MemberSpecializationInfo *MSInfo
1225                = D->getMemberSpecializationInfo()) {
1226     Record.push_back(CXXRecMemberSpecialization);
1227     Record.AddDeclRef(MSInfo->getInstantiatedFrom());
1228     Record.push_back(MSInfo->getTemplateSpecializationKind());
1229     Record.AddSourceLocation(MSInfo->getPointOfInstantiation());
1230   } else {
1231     Record.push_back(CXXRecNotTemplate);
1232   }
1233
1234   Record.push_back(D->isThisDeclarationADefinition());
1235   if (D->isThisDeclarationADefinition())
1236     Record.AddCXXDefinitionData(D);
1237
1238   // Store (what we currently believe to be) the key function to avoid
1239   // deserializing every method so we can compute it.
1240   if (D->IsCompleteDefinition)
1241     Record.AddDeclRef(Context.getCurrentKeyFunction(D));
1242
1243   Code = serialization::DECL_CXX_RECORD;
1244 }
1245
1246 void ASTDeclWriter::VisitCXXMethodDecl(CXXMethodDecl *D) {
1247   VisitFunctionDecl(D);
1248   if (D->isCanonicalDecl()) {
1249     Record.push_back(D->size_overridden_methods());
1250     for (CXXMethodDecl::method_iterator
1251            I = D->begin_overridden_methods(), E = D->end_overridden_methods();
1252            I != E; ++I)
1253       Record.AddDeclRef(*I);
1254   } else {
1255     // We only need to record overridden methods once for the canonical decl.
1256     Record.push_back(0);
1257   }
1258
1259   if (D->getDeclContext() == D->getLexicalDeclContext() &&
1260       D->getFirstDecl() == D->getMostRecentDecl() &&
1261       !D->isInvalidDecl() &&
1262       !D->hasAttrs() &&
1263       !D->isTopLevelDeclInObjCContainer() &&
1264       D->getDeclName().getNameKind() == DeclarationName::Identifier &&
1265       !D->hasExtInfo() &&
1266       !D->hasInheritedPrototype() &&
1267       D->hasWrittenPrototype())
1268     AbbrevToUse = Writer.getDeclCXXMethodAbbrev();
1269
1270   Code = serialization::DECL_CXX_METHOD;
1271 }
1272
1273 void ASTDeclWriter::VisitCXXConstructorDecl(CXXConstructorDecl *D) {
1274   if (auto Inherited = D->getInheritedConstructor()) {
1275     Record.AddDeclRef(Inherited.getShadowDecl());
1276     Record.AddDeclRef(Inherited.getConstructor());
1277     Code = serialization::DECL_CXX_INHERITED_CONSTRUCTOR;
1278   } else {
1279     Code = serialization::DECL_CXX_CONSTRUCTOR;
1280   }
1281
1282   VisitCXXMethodDecl(D);
1283
1284   Code = D->isInheritingConstructor()
1285              ? serialization::DECL_CXX_INHERITED_CONSTRUCTOR
1286              : serialization::DECL_CXX_CONSTRUCTOR;
1287 }
1288
1289 void ASTDeclWriter::VisitCXXDestructorDecl(CXXDestructorDecl *D) {
1290   VisitCXXMethodDecl(D);
1291
1292   Record.AddDeclRef(D->getOperatorDelete());
1293
1294   Code = serialization::DECL_CXX_DESTRUCTOR;
1295 }
1296
1297 void ASTDeclWriter::VisitCXXConversionDecl(CXXConversionDecl *D) {
1298   VisitCXXMethodDecl(D);
1299   Code = serialization::DECL_CXX_CONVERSION;
1300 }
1301
1302 void ASTDeclWriter::VisitImportDecl(ImportDecl *D) {
1303   VisitDecl(D);
1304   Record.push_back(Writer.getSubmoduleID(D->getImportedModule()));
1305   ArrayRef<SourceLocation> IdentifierLocs = D->getIdentifierLocs();
1306   Record.push_back(!IdentifierLocs.empty());
1307   if (IdentifierLocs.empty()) {
1308     Record.AddSourceLocation(D->getLocEnd());
1309     Record.push_back(1);
1310   } else {
1311     for (unsigned I = 0, N = IdentifierLocs.size(); I != N; ++I)
1312       Record.AddSourceLocation(IdentifierLocs[I]);
1313     Record.push_back(IdentifierLocs.size());
1314   }
1315   // Note: the number of source locations must always be the last element in
1316   // the record.
1317   Code = serialization::DECL_IMPORT;
1318 }
1319
1320 void ASTDeclWriter::VisitAccessSpecDecl(AccessSpecDecl *D) {
1321   VisitDecl(D);
1322   Record.AddSourceLocation(D->getColonLoc());
1323   Code = serialization::DECL_ACCESS_SPEC;
1324 }
1325
1326 void ASTDeclWriter::VisitFriendDecl(FriendDecl *D) {
1327   // Record the number of friend type template parameter lists here
1328   // so as to simplify memory allocation during deserialization.
1329   Record.push_back(D->NumTPLists);
1330   VisitDecl(D);
1331   bool hasFriendDecl = D->Friend.is<NamedDecl*>();
1332   Record.push_back(hasFriendDecl);
1333   if (hasFriendDecl)
1334     Record.AddDeclRef(D->getFriendDecl());
1335   else
1336     Record.AddTypeSourceInfo(D->getFriendType());
1337   for (unsigned i = 0; i < D->NumTPLists; ++i)
1338     Record.AddTemplateParameterList(D->getFriendTypeTemplateParameterList(i));
1339   Record.AddDeclRef(D->getNextFriend());
1340   Record.push_back(D->UnsupportedFriend);
1341   Record.AddSourceLocation(D->FriendLoc);
1342   Code = serialization::DECL_FRIEND;
1343 }
1344
1345 void ASTDeclWriter::VisitFriendTemplateDecl(FriendTemplateDecl *D) {
1346   VisitDecl(D);
1347   Record.push_back(D->getNumTemplateParameters());
1348   for (unsigned i = 0, e = D->getNumTemplateParameters(); i != e; ++i)
1349     Record.AddTemplateParameterList(D->getTemplateParameterList(i));
1350   Record.push_back(D->getFriendDecl() != nullptr);
1351   if (D->getFriendDecl())
1352     Record.AddDeclRef(D->getFriendDecl());
1353   else
1354     Record.AddTypeSourceInfo(D->getFriendType());
1355   Record.AddSourceLocation(D->getFriendLoc());
1356   Code = serialization::DECL_FRIEND_TEMPLATE;
1357 }
1358
1359 void ASTDeclWriter::VisitTemplateDecl(TemplateDecl *D) {
1360   VisitNamedDecl(D);
1361
1362   Record.AddDeclRef(D->getTemplatedDecl());
1363   Record.AddTemplateParameterList(D->getTemplateParameters());
1364 }
1365
1366 void ASTDeclWriter::VisitRedeclarableTemplateDecl(RedeclarableTemplateDecl *D) {
1367   VisitRedeclarable(D);
1368
1369   // Emit data to initialize CommonOrPrev before VisitTemplateDecl so that
1370   // getCommonPtr() can be used while this is still initializing.
1371   if (D->isFirstDecl()) {
1372     // This declaration owns the 'common' pointer, so serialize that data now.
1373     Record.AddDeclRef(D->getInstantiatedFromMemberTemplate());
1374     if (D->getInstantiatedFromMemberTemplate())
1375       Record.push_back(D->isMemberSpecialization());
1376   }
1377
1378   VisitTemplateDecl(D);
1379   Record.push_back(D->getIdentifierNamespace());
1380 }
1381
1382 void ASTDeclWriter::VisitClassTemplateDecl(ClassTemplateDecl *D) {
1383   VisitRedeclarableTemplateDecl(D);
1384
1385   if (D->isFirstDecl())
1386     AddTemplateSpecializations(D);
1387   Code = serialization::DECL_CLASS_TEMPLATE;
1388 }
1389
1390 void ASTDeclWriter::VisitClassTemplateSpecializationDecl(
1391                                            ClassTemplateSpecializationDecl *D) {
1392   RegisterTemplateSpecialization(D->getSpecializedTemplate(), D);
1393
1394   VisitCXXRecordDecl(D);
1395
1396   llvm::PointerUnion<ClassTemplateDecl *,
1397                      ClassTemplatePartialSpecializationDecl *> InstFrom
1398     = D->getSpecializedTemplateOrPartial();
1399   if (Decl *InstFromD = InstFrom.dyn_cast<ClassTemplateDecl *>()) {
1400     Record.AddDeclRef(InstFromD);
1401   } else {
1402     Record.AddDeclRef(InstFrom.get<ClassTemplatePartialSpecializationDecl *>());
1403     Record.AddTemplateArgumentList(&D->getTemplateInstantiationArgs());
1404   }
1405
1406   Record.AddTemplateArgumentList(&D->getTemplateArgs());
1407   Record.AddSourceLocation(D->getPointOfInstantiation());
1408   Record.push_back(D->getSpecializationKind());
1409   Record.push_back(D->isCanonicalDecl());
1410
1411   if (D->isCanonicalDecl()) {
1412     // When reading, we'll add it to the folding set of the following template.
1413     Record.AddDeclRef(D->getSpecializedTemplate()->getCanonicalDecl());
1414   }
1415
1416   // Explicit info.
1417   Record.AddTypeSourceInfo(D->getTypeAsWritten());
1418   if (D->getTypeAsWritten()) {
1419     Record.AddSourceLocation(D->getExternLoc());
1420     Record.AddSourceLocation(D->getTemplateKeywordLoc());
1421   }
1422
1423   Code = serialization::DECL_CLASS_TEMPLATE_SPECIALIZATION;
1424 }
1425
1426 void ASTDeclWriter::VisitClassTemplatePartialSpecializationDecl(
1427                                     ClassTemplatePartialSpecializationDecl *D) {
1428   VisitClassTemplateSpecializationDecl(D);
1429
1430   Record.AddTemplateParameterList(D->getTemplateParameters());
1431   Record.AddASTTemplateArgumentListInfo(D->getTemplateArgsAsWritten());
1432
1433   // These are read/set from/to the first declaration.
1434   if (D->getPreviousDecl() == nullptr) {
1435     Record.AddDeclRef(D->getInstantiatedFromMember());
1436     Record.push_back(D->isMemberSpecialization());
1437   }
1438
1439   Code = serialization::DECL_CLASS_TEMPLATE_PARTIAL_SPECIALIZATION;
1440 }
1441
1442 void ASTDeclWriter::VisitVarTemplateDecl(VarTemplateDecl *D) {
1443   VisitRedeclarableTemplateDecl(D);
1444
1445   if (D->isFirstDecl())
1446     AddTemplateSpecializations(D);
1447   Code = serialization::DECL_VAR_TEMPLATE;
1448 }
1449
1450 void ASTDeclWriter::VisitVarTemplateSpecializationDecl(
1451     VarTemplateSpecializationDecl *D) {
1452   RegisterTemplateSpecialization(D->getSpecializedTemplate(), D);
1453
1454   VisitVarDecl(D);
1455
1456   llvm::PointerUnion<VarTemplateDecl *, VarTemplatePartialSpecializationDecl *>
1457   InstFrom = D->getSpecializedTemplateOrPartial();
1458   if (Decl *InstFromD = InstFrom.dyn_cast<VarTemplateDecl *>()) {
1459     Record.AddDeclRef(InstFromD);
1460   } else {
1461     Record.AddDeclRef(InstFrom.get<VarTemplatePartialSpecializationDecl *>());
1462     Record.AddTemplateArgumentList(&D->getTemplateInstantiationArgs());
1463   }
1464
1465   // Explicit info.
1466   Record.AddTypeSourceInfo(D->getTypeAsWritten());
1467   if (D->getTypeAsWritten()) {
1468     Record.AddSourceLocation(D->getExternLoc());
1469     Record.AddSourceLocation(D->getTemplateKeywordLoc());
1470   }
1471
1472   Record.AddTemplateArgumentList(&D->getTemplateArgs());
1473   Record.AddSourceLocation(D->getPointOfInstantiation());
1474   Record.push_back(D->getSpecializationKind());
1475   Record.push_back(D->isCanonicalDecl());
1476
1477   if (D->isCanonicalDecl()) {
1478     // When reading, we'll add it to the folding set of the following template.
1479     Record.AddDeclRef(D->getSpecializedTemplate()->getCanonicalDecl());
1480   }
1481
1482   Code = serialization::DECL_VAR_TEMPLATE_SPECIALIZATION;
1483 }
1484
1485 void ASTDeclWriter::VisitVarTemplatePartialSpecializationDecl(
1486     VarTemplatePartialSpecializationDecl *D) {
1487   VisitVarTemplateSpecializationDecl(D);
1488
1489   Record.AddTemplateParameterList(D->getTemplateParameters());
1490   Record.AddASTTemplateArgumentListInfo(D->getTemplateArgsAsWritten());
1491
1492   // These are read/set from/to the first declaration.
1493   if (D->getPreviousDecl() == nullptr) {
1494     Record.AddDeclRef(D->getInstantiatedFromMember());
1495     Record.push_back(D->isMemberSpecialization());
1496   }
1497
1498   Code = serialization::DECL_VAR_TEMPLATE_PARTIAL_SPECIALIZATION;
1499 }
1500
1501 void ASTDeclWriter::VisitClassScopeFunctionSpecializationDecl(
1502                                     ClassScopeFunctionSpecializationDecl *D) {
1503   VisitDecl(D);
1504   Record.AddDeclRef(D->getSpecialization());
1505   Code = serialization::DECL_CLASS_SCOPE_FUNCTION_SPECIALIZATION;
1506 }
1507
1508
1509 void ASTDeclWriter::VisitFunctionTemplateDecl(FunctionTemplateDecl *D) {
1510   VisitRedeclarableTemplateDecl(D);
1511
1512   if (D->isFirstDecl())
1513     AddTemplateSpecializations(D);
1514   Code = serialization::DECL_FUNCTION_TEMPLATE;
1515 }
1516
1517 void ASTDeclWriter::VisitTemplateTypeParmDecl(TemplateTypeParmDecl *D) {
1518   VisitTypeDecl(D);
1519
1520   Record.push_back(D->wasDeclaredWithTypename());
1521
1522   bool OwnsDefaultArg = D->hasDefaultArgument() &&
1523                         !D->defaultArgumentWasInherited();
1524   Record.push_back(OwnsDefaultArg);
1525   if (OwnsDefaultArg)
1526     Record.AddTypeSourceInfo(D->getDefaultArgumentInfo());
1527
1528   Code = serialization::DECL_TEMPLATE_TYPE_PARM;
1529 }
1530
1531 void ASTDeclWriter::VisitNonTypeTemplateParmDecl(NonTypeTemplateParmDecl *D) {
1532   // For an expanded parameter pack, record the number of expansion types here
1533   // so that it's easier for deserialization to allocate the right amount of
1534   // memory.
1535   if (D->isExpandedParameterPack())
1536     Record.push_back(D->getNumExpansionTypes());
1537
1538   VisitDeclaratorDecl(D);
1539   // TemplateParmPosition.
1540   Record.push_back(D->getDepth());
1541   Record.push_back(D->getPosition());
1542
1543   if (D->isExpandedParameterPack()) {
1544     for (unsigned I = 0, N = D->getNumExpansionTypes(); I != N; ++I) {
1545       Record.AddTypeRef(D->getExpansionType(I));
1546       Record.AddTypeSourceInfo(D->getExpansionTypeSourceInfo(I));
1547     }
1548
1549     Code = serialization::DECL_EXPANDED_NON_TYPE_TEMPLATE_PARM_PACK;
1550   } else {
1551     // Rest of NonTypeTemplateParmDecl.
1552     Record.push_back(D->isParameterPack());
1553     bool OwnsDefaultArg = D->hasDefaultArgument() &&
1554                           !D->defaultArgumentWasInherited();
1555     Record.push_back(OwnsDefaultArg);
1556     if (OwnsDefaultArg)
1557       Record.AddStmt(D->getDefaultArgument());
1558     Code = serialization::DECL_NON_TYPE_TEMPLATE_PARM;
1559   }
1560 }
1561
1562 void ASTDeclWriter::VisitTemplateTemplateParmDecl(TemplateTemplateParmDecl *D) {
1563   // For an expanded parameter pack, record the number of expansion types here
1564   // so that it's easier for deserialization to allocate the right amount of
1565   // memory.
1566   if (D->isExpandedParameterPack())
1567     Record.push_back(D->getNumExpansionTemplateParameters());
1568
1569   VisitTemplateDecl(D);
1570   // TemplateParmPosition.
1571   Record.push_back(D->getDepth());
1572   Record.push_back(D->getPosition());
1573
1574   if (D->isExpandedParameterPack()) {
1575     for (unsigned I = 0, N = D->getNumExpansionTemplateParameters();
1576          I != N; ++I)
1577       Record.AddTemplateParameterList(D->getExpansionTemplateParameters(I));
1578     Code = serialization::DECL_EXPANDED_TEMPLATE_TEMPLATE_PARM_PACK;
1579   } else {
1580     // Rest of TemplateTemplateParmDecl.
1581     Record.push_back(D->isParameterPack());
1582     bool OwnsDefaultArg = D->hasDefaultArgument() &&
1583                           !D->defaultArgumentWasInherited();
1584     Record.push_back(OwnsDefaultArg);
1585     if (OwnsDefaultArg)
1586       Record.AddTemplateArgumentLoc(D->getDefaultArgument());
1587     Code = serialization::DECL_TEMPLATE_TEMPLATE_PARM;
1588   }
1589 }
1590
1591 void ASTDeclWriter::VisitTypeAliasTemplateDecl(TypeAliasTemplateDecl *D) {
1592   VisitRedeclarableTemplateDecl(D);
1593   Code = serialization::DECL_TYPE_ALIAS_TEMPLATE;
1594 }
1595
1596 void ASTDeclWriter::VisitStaticAssertDecl(StaticAssertDecl *D) {
1597   VisitDecl(D);
1598   Record.AddStmt(D->getAssertExpr());
1599   Record.push_back(D->isFailed());
1600   Record.AddStmt(D->getMessage());
1601   Record.AddSourceLocation(D->getRParenLoc());
1602   Code = serialization::DECL_STATIC_ASSERT;
1603 }
1604
1605 /// \brief Emit the DeclContext part of a declaration context decl.
1606 void ASTDeclWriter::VisitDeclContext(DeclContext *DC) {
1607   Record.AddOffset(Writer.WriteDeclContextLexicalBlock(Context, DC));
1608   Record.AddOffset(Writer.WriteDeclContextVisibleBlock(Context, DC));
1609 }
1610
1611 const Decl *ASTWriter::getFirstLocalDecl(const Decl *D) {
1612   assert(IsLocalDecl(D) && "expected a local declaration");
1613
1614   const Decl *Canon = D->getCanonicalDecl();
1615   if (IsLocalDecl(Canon))
1616     return Canon;
1617
1618   const Decl *&CacheEntry = FirstLocalDeclCache[Canon];
1619   if (CacheEntry)
1620     return CacheEntry;
1621
1622   for (const Decl *Redecl = D; Redecl; Redecl = Redecl->getPreviousDecl())
1623     if (IsLocalDecl(Redecl))
1624       D = Redecl;
1625   return CacheEntry = D;
1626 }
1627
1628 template <typename T>
1629 void ASTDeclWriter::VisitRedeclarable(Redeclarable<T> *D) {
1630   T *First = D->getFirstDecl();
1631   T *MostRecent = First->getMostRecentDecl();
1632   T *DAsT = static_cast<T *>(D);
1633   if (MostRecent != First) {
1634     assert(isRedeclarableDeclKind(DAsT->getKind()) &&
1635            "Not considered redeclarable?");
1636
1637     Record.AddDeclRef(First);
1638
1639     // Write out a list of local redeclarations of this declaration if it's the
1640     // first local declaration in the chain.
1641     const Decl *FirstLocal = Writer.getFirstLocalDecl(DAsT);
1642     if (DAsT == FirstLocal) {
1643       // Emit a list of all imported first declarations so that we can be sure
1644       // that all redeclarations visible to this module are before D in the
1645       // redecl chain.
1646       unsigned I = Record.size();
1647       Record.push_back(0);
1648       if (Writer.Chain)
1649         AddFirstDeclFromEachModule(DAsT, /*IncludeLocal*/false);
1650       // This is the number of imported first declarations + 1.
1651       Record[I] = Record.size() - I;
1652
1653       // Collect the set of local redeclarations of this declaration, from
1654       // newest to oldest.
1655       ASTWriter::RecordData LocalRedecls;
1656       ASTRecordWriter LocalRedeclWriter(Record, LocalRedecls);
1657       for (const Decl *Prev = FirstLocal->getMostRecentDecl();
1658            Prev != FirstLocal; Prev = Prev->getPreviousDecl())
1659         if (!Prev->isFromASTFile())
1660           LocalRedeclWriter.AddDeclRef(Prev);
1661
1662       // If we have any redecls, write them now as a separate record preceding
1663       // the declaration itself.
1664       if (LocalRedecls.empty())
1665         Record.push_back(0);
1666       else
1667         Record.AddOffset(LocalRedeclWriter.Emit(LOCAL_REDECLARATIONS));
1668     } else {
1669       Record.push_back(0);
1670       Record.AddDeclRef(FirstLocal);
1671     }
1672
1673     // Make sure that we serialize both the previous and the most-recent
1674     // declarations, which (transitively) ensures that all declarations in the
1675     // chain get serialized.
1676     //
1677     // FIXME: This is not correct; when we reach an imported declaration we
1678     // won't emit its previous declaration.
1679     (void)Writer.GetDeclRef(D->getPreviousDecl());
1680     (void)Writer.GetDeclRef(MostRecent);
1681   } else {
1682     // We use the sentinel value 0 to indicate an only declaration.
1683     Record.push_back(0);
1684   }
1685 }
1686
1687 void ASTDeclWriter::VisitOMPThreadPrivateDecl(OMPThreadPrivateDecl *D) {
1688   Record.push_back(D->varlist_size());
1689   VisitDecl(D);
1690   for (auto *I : D->varlists())
1691     Record.AddStmt(I);
1692   Code = serialization::DECL_OMP_THREADPRIVATE;
1693 }
1694
1695 void ASTDeclWriter::VisitOMPDeclareReductionDecl(OMPDeclareReductionDecl *D) {
1696   VisitValueDecl(D);
1697   Record.AddSourceLocation(D->getLocStart());
1698   Record.AddStmt(D->getCombiner());
1699   Record.AddStmt(D->getInitializer());
1700   Record.AddDeclRef(D->getPrevDeclInScope());
1701   Code = serialization::DECL_OMP_DECLARE_REDUCTION;
1702 }
1703
1704 void ASTDeclWriter::VisitOMPCapturedExprDecl(OMPCapturedExprDecl *D) {
1705   VisitVarDecl(D);
1706   Code = serialization::DECL_OMP_CAPTUREDEXPR;
1707 }
1708
1709 //===----------------------------------------------------------------------===//
1710 // ASTWriter Implementation
1711 //===----------------------------------------------------------------------===//
1712
1713 void ASTWriter::WriteDeclAbbrevs() {
1714   using namespace llvm;
1715
1716   std::shared_ptr<BitCodeAbbrev> Abv;
1717
1718   // Abbreviation for DECL_FIELD
1719   Abv = std::make_shared<BitCodeAbbrev>();
1720   Abv->Add(BitCodeAbbrevOp(serialization::DECL_FIELD));
1721   // Decl
1722   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclContext
1723   Abv->Add(BitCodeAbbrevOp(0));                       // LexicalDeclContext
1724   Abv->Add(BitCodeAbbrevOp(0));                       // isInvalidDecl
1725   Abv->Add(BitCodeAbbrevOp(0));                       // HasAttrs
1726   Abv->Add(BitCodeAbbrevOp(0));                       // isImplicit
1727   Abv->Add(BitCodeAbbrevOp(0));                       // isUsed
1728   Abv->Add(BitCodeAbbrevOp(0));                       // isReferenced
1729   Abv->Add(BitCodeAbbrevOp(0));                   // TopLevelDeclInObjCContainer
1730   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2));  // AccessSpecifier
1731   Abv->Add(BitCodeAbbrevOp(0));                       // ModulePrivate
1732   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // SubmoduleID
1733   // NamedDecl
1734   Abv->Add(BitCodeAbbrevOp(0));                       // NameKind = Identifier
1735   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Name
1736   Abv->Add(BitCodeAbbrevOp(0));                       // AnonDeclNumber
1737   // ValueDecl
1738   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
1739   // DeclaratorDecl
1740   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // InnerStartLoc
1741   Abv->Add(BitCodeAbbrevOp(0));                       // hasExtInfo
1742   // FieldDecl
1743   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isMutable
1744   Abv->Add(BitCodeAbbrevOp(0));                       //getBitWidth
1745   // Type Source Info
1746   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1747   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1748   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // TypeLoc
1749   DeclFieldAbbrev = Stream.EmitAbbrev(std::move(Abv));
1750
1751   // Abbreviation for DECL_OBJC_IVAR
1752   Abv = std::make_shared<BitCodeAbbrev>();
1753   Abv->Add(BitCodeAbbrevOp(serialization::DECL_OBJC_IVAR));
1754   // Decl
1755   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclContext
1756   Abv->Add(BitCodeAbbrevOp(0));                       // LexicalDeclContext
1757   Abv->Add(BitCodeAbbrevOp(0));                       // isInvalidDecl
1758   Abv->Add(BitCodeAbbrevOp(0));                       // HasAttrs
1759   Abv->Add(BitCodeAbbrevOp(0));                       // isImplicit
1760   Abv->Add(BitCodeAbbrevOp(0));                       // isUsed
1761   Abv->Add(BitCodeAbbrevOp(0));                       // isReferenced
1762   Abv->Add(BitCodeAbbrevOp(0));                   // TopLevelDeclInObjCContainer
1763   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2));  // AccessSpecifier
1764   Abv->Add(BitCodeAbbrevOp(0));                       // ModulePrivate
1765   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // SubmoduleID
1766   // NamedDecl
1767   Abv->Add(BitCodeAbbrevOp(0));                       // NameKind = Identifier
1768   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Name
1769   Abv->Add(BitCodeAbbrevOp(0));                       // AnonDeclNumber
1770   // ValueDecl
1771   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
1772   // DeclaratorDecl
1773   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // InnerStartLoc
1774   Abv->Add(BitCodeAbbrevOp(0));                       // hasExtInfo
1775   // FieldDecl
1776   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isMutable
1777   Abv->Add(BitCodeAbbrevOp(0));                       //getBitWidth
1778   // ObjC Ivar
1779   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // getAccessControl
1780   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // getSynthesize
1781   // Type Source Info
1782   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1783   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1784   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // TypeLoc
1785   DeclObjCIvarAbbrev = Stream.EmitAbbrev(std::move(Abv));
1786
1787   // Abbreviation for DECL_ENUM
1788   Abv = std::make_shared<BitCodeAbbrev>();
1789   Abv->Add(BitCodeAbbrevOp(serialization::DECL_ENUM));
1790   // Redeclarable
1791   Abv->Add(BitCodeAbbrevOp(0));                       // No redeclaration
1792   // Decl
1793   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclContext
1794   Abv->Add(BitCodeAbbrevOp(0));                       // LexicalDeclContext
1795   Abv->Add(BitCodeAbbrevOp(0));                       // isInvalidDecl
1796   Abv->Add(BitCodeAbbrevOp(0));                       // HasAttrs
1797   Abv->Add(BitCodeAbbrevOp(0));                       // isImplicit
1798   Abv->Add(BitCodeAbbrevOp(0));                       // isUsed
1799   Abv->Add(BitCodeAbbrevOp(0));                       // isReferenced
1800   Abv->Add(BitCodeAbbrevOp(0));                   // TopLevelDeclInObjCContainer
1801   Abv->Add(BitCodeAbbrevOp(AS_none));                 // C++ AccessSpecifier
1802   Abv->Add(BitCodeAbbrevOp(0));                       // ModulePrivate
1803   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // SubmoduleID
1804   // NamedDecl
1805   Abv->Add(BitCodeAbbrevOp(0));                       // NameKind = Identifier
1806   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Name
1807   Abv->Add(BitCodeAbbrevOp(0));                       // AnonDeclNumber
1808   // TypeDecl
1809   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Source Location
1810   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type Ref
1811   // TagDecl
1812   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // IdentifierNamespace
1813   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // getTagKind
1814   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isCompleteDefinition
1815   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // EmbeddedInDeclarator
1816   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsFreeStanding
1817   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsCompleteDefinitionRequired
1818   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // SourceLocation
1819   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // SourceLocation
1820   Abv->Add(BitCodeAbbrevOp(0));                         // ExtInfoKind
1821   // EnumDecl
1822   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // AddTypeRef
1823   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // IntegerType
1824   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // getPromotionType
1825   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // getNumPositiveBits
1826   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // getNumNegativeBits
1827   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isScoped
1828   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isScopedUsingClassTag
1829   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isFixed
1830   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // InstantiatedMembEnum
1831   // DC
1832   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // LexicalOffset
1833   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // VisibleOffset
1834   DeclEnumAbbrev = Stream.EmitAbbrev(std::move(Abv));
1835
1836   // Abbreviation for DECL_RECORD
1837   Abv = std::make_shared<BitCodeAbbrev>();
1838   Abv->Add(BitCodeAbbrevOp(serialization::DECL_RECORD));
1839   // Redeclarable
1840   Abv->Add(BitCodeAbbrevOp(0));                       // No redeclaration
1841   // Decl
1842   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclContext
1843   Abv->Add(BitCodeAbbrevOp(0));                       // LexicalDeclContext
1844   Abv->Add(BitCodeAbbrevOp(0));                       // isInvalidDecl
1845   Abv->Add(BitCodeAbbrevOp(0));                       // HasAttrs
1846   Abv->Add(BitCodeAbbrevOp(0));                       // isImplicit
1847   Abv->Add(BitCodeAbbrevOp(0));                       // isUsed
1848   Abv->Add(BitCodeAbbrevOp(0));                       // isReferenced
1849   Abv->Add(BitCodeAbbrevOp(0));                   // TopLevelDeclInObjCContainer
1850   Abv->Add(BitCodeAbbrevOp(AS_none));                 // C++ AccessSpecifier
1851   Abv->Add(BitCodeAbbrevOp(0));                       // ModulePrivate
1852   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // SubmoduleID
1853   // NamedDecl
1854   Abv->Add(BitCodeAbbrevOp(0));                       // NameKind = Identifier
1855   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Name
1856   Abv->Add(BitCodeAbbrevOp(0));                       // AnonDeclNumber
1857   // TypeDecl
1858   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Source Location
1859   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type Ref
1860   // TagDecl
1861   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // IdentifierNamespace
1862   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // getTagKind
1863   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isCompleteDefinition
1864   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // EmbeddedInDeclarator
1865   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsFreeStanding
1866   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsCompleteDefinitionRequired
1867   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // SourceLocation
1868   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // SourceLocation
1869   Abv->Add(BitCodeAbbrevOp(0));                         // ExtInfoKind
1870   // RecordDecl
1871   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // FlexibleArrayMember
1872   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // AnonymousStructUnion
1873   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // hasObjectMember
1874   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // hasVolatileMember
1875   // DC
1876   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // LexicalOffset
1877   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // VisibleOffset
1878   DeclRecordAbbrev = Stream.EmitAbbrev(std::move(Abv));
1879
1880   // Abbreviation for DECL_PARM_VAR
1881   Abv = std::make_shared<BitCodeAbbrev>();
1882   Abv->Add(BitCodeAbbrevOp(serialization::DECL_PARM_VAR));
1883   // Redeclarable
1884   Abv->Add(BitCodeAbbrevOp(0));                       // No redeclaration
1885   // Decl
1886   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclContext
1887   Abv->Add(BitCodeAbbrevOp(0));                       // LexicalDeclContext
1888   Abv->Add(BitCodeAbbrevOp(0));                       // isInvalidDecl
1889   Abv->Add(BitCodeAbbrevOp(0));                       // HasAttrs
1890   Abv->Add(BitCodeAbbrevOp(0));                       // isImplicit
1891   Abv->Add(BitCodeAbbrevOp(0));                       // isUsed
1892   Abv->Add(BitCodeAbbrevOp(0));                       // isReferenced
1893   Abv->Add(BitCodeAbbrevOp(0));                   // TopLevelDeclInObjCContainer
1894   Abv->Add(BitCodeAbbrevOp(AS_none));                 // C++ AccessSpecifier
1895   Abv->Add(BitCodeAbbrevOp(0));                       // ModulePrivate
1896   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // SubmoduleID
1897   // NamedDecl
1898   Abv->Add(BitCodeAbbrevOp(0));                       // NameKind = Identifier
1899   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Name
1900   Abv->Add(BitCodeAbbrevOp(0));                       // AnonDeclNumber
1901   // ValueDecl
1902   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
1903   // DeclaratorDecl
1904   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // InnerStartLoc
1905   Abv->Add(BitCodeAbbrevOp(0));                       // hasExtInfo
1906   // VarDecl
1907   Abv->Add(BitCodeAbbrevOp(0));                       // SClass
1908   Abv->Add(BitCodeAbbrevOp(0));                       // TSCSpec
1909   Abv->Add(BitCodeAbbrevOp(0));                       // InitStyle
1910   Abv->Add(BitCodeAbbrevOp(0));                       // Linkage
1911   Abv->Add(BitCodeAbbrevOp(0));                       // HasInit
1912   Abv->Add(BitCodeAbbrevOp(0));                   // HasMemberSpecializationInfo
1913   // ParmVarDecl
1914   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsObjCMethodParameter
1915   Abv->Add(BitCodeAbbrevOp(0));                       // ScopeDepth
1916   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // ScopeIndex
1917   Abv->Add(BitCodeAbbrevOp(0));                       // ObjCDeclQualifier
1918   Abv->Add(BitCodeAbbrevOp(0));                       // KNRPromoted
1919   Abv->Add(BitCodeAbbrevOp(0));                       // HasInheritedDefaultArg
1920   Abv->Add(BitCodeAbbrevOp(0));                   // HasUninstantiatedDefaultArg
1921   // Type Source Info
1922   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1923   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1924   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // TypeLoc
1925   DeclParmVarAbbrev = Stream.EmitAbbrev(std::move(Abv));
1926
1927   // Abbreviation for DECL_TYPEDEF
1928   Abv = std::make_shared<BitCodeAbbrev>();
1929   Abv->Add(BitCodeAbbrevOp(serialization::DECL_TYPEDEF));
1930   // Redeclarable
1931   Abv->Add(BitCodeAbbrevOp(0));                       // No redeclaration
1932   // Decl
1933   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclContext
1934   Abv->Add(BitCodeAbbrevOp(0));                       // LexicalDeclContext
1935   Abv->Add(BitCodeAbbrevOp(0));                       // isInvalidDecl
1936   Abv->Add(BitCodeAbbrevOp(0));                       // HasAttrs
1937   Abv->Add(BitCodeAbbrevOp(0));                       // isImplicit
1938   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isUsed
1939   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isReferenced
1940   Abv->Add(BitCodeAbbrevOp(0));                   // TopLevelDeclInObjCContainer
1941   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2)); // C++ AccessSpecifier
1942   Abv->Add(BitCodeAbbrevOp(0));                       // ModulePrivate
1943   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // SubmoduleID
1944   // NamedDecl
1945   Abv->Add(BitCodeAbbrevOp(0));                       // NameKind = Identifier
1946   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Name
1947   Abv->Add(BitCodeAbbrevOp(0));                       // AnonDeclNumber
1948   // TypeDecl
1949   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Source Location
1950   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type Ref
1951   // TypedefDecl
1952   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1953   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // TypeLoc
1954   DeclTypedefAbbrev = Stream.EmitAbbrev(std::move(Abv));
1955
1956   // Abbreviation for DECL_VAR
1957   Abv = std::make_shared<BitCodeAbbrev>();
1958   Abv->Add(BitCodeAbbrevOp(serialization::DECL_VAR));
1959   // Redeclarable
1960   Abv->Add(BitCodeAbbrevOp(0));                       // No redeclaration
1961   // Decl
1962   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclContext
1963   Abv->Add(BitCodeAbbrevOp(0));                       // LexicalDeclContext
1964   Abv->Add(BitCodeAbbrevOp(0));                       // isInvalidDecl
1965   Abv->Add(BitCodeAbbrevOp(0));                       // HasAttrs
1966   Abv->Add(BitCodeAbbrevOp(0));                       // isImplicit
1967   Abv->Add(BitCodeAbbrevOp(0));                       // isUsed
1968   Abv->Add(BitCodeAbbrevOp(0));                       // isReferenced
1969   Abv->Add(BitCodeAbbrevOp(0));                   // TopLevelDeclInObjCContainer
1970   Abv->Add(BitCodeAbbrevOp(AS_none));                 // C++ AccessSpecifier
1971   Abv->Add(BitCodeAbbrevOp(0));                       // ModulePrivate
1972   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // SubmoduleID
1973   // NamedDecl
1974   Abv->Add(BitCodeAbbrevOp(0));                       // NameKind = Identifier
1975   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Name
1976   Abv->Add(BitCodeAbbrevOp(0));                       // AnonDeclNumber
1977   // ValueDecl
1978   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
1979   // DeclaratorDecl
1980   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // InnerStartLoc
1981   Abv->Add(BitCodeAbbrevOp(0));                       // hasExtInfo
1982   // VarDecl
1983   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); // SClass
1984   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2)); // TSCSpec
1985   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2)); // InitStyle
1986   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsThisDeclarationADemotedDefinition
1987   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isExceptionVariable
1988   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isNRVOVariable
1989   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isCXXForRangeDecl
1990   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isARCPseudoStrong
1991   Abv->Add(BitCodeAbbrevOp(0));                         // isInline
1992   Abv->Add(BitCodeAbbrevOp(0));                         // isInlineSpecified
1993   Abv->Add(BitCodeAbbrevOp(0));                         // isConstexpr
1994   Abv->Add(BitCodeAbbrevOp(0));                         // isInitCapture
1995   Abv->Add(BitCodeAbbrevOp(0));                         // isPrevDeclInSameScope
1996   Abv->Add(BitCodeAbbrevOp(0));                         // ImplicitParamKind
1997   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); // Linkage
1998   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2)); // IsInitICE (local)
1999   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2)); // VarKind (local enum)
2000   // Type Source Info
2001   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
2002   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2003   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // TypeLoc
2004   DeclVarAbbrev = Stream.EmitAbbrev(std::move(Abv));
2005
2006   // Abbreviation for DECL_CXX_METHOD
2007   Abv = std::make_shared<BitCodeAbbrev>();
2008   Abv->Add(BitCodeAbbrevOp(serialization::DECL_CXX_METHOD));
2009   // RedeclarableDecl
2010   Abv->Add(BitCodeAbbrevOp(0));                         // CanonicalDecl
2011   // Decl
2012   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // DeclContext
2013   Abv->Add(BitCodeAbbrevOp(0));                         // LexicalDeclContext
2014   Abv->Add(BitCodeAbbrevOp(0));                         // Invalid
2015   Abv->Add(BitCodeAbbrevOp(0));                         // HasAttrs
2016   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Implicit
2017   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Used
2018   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Referenced
2019   Abv->Add(BitCodeAbbrevOp(0));                         // InObjCContainer
2020   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2)); // Access
2021   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // ModulePrivate
2022   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // SubmoduleID
2023   // NamedDecl
2024   Abv->Add(BitCodeAbbrevOp(DeclarationName::Identifier)); // NameKind
2025   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // Identifier
2026   Abv->Add(BitCodeAbbrevOp(0));                         // AnonDeclNumber
2027   // ValueDecl
2028   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // Type
2029   // DeclaratorDecl
2030   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // InnerLocStart
2031   Abv->Add(BitCodeAbbrevOp(0));                         // HasExtInfo
2032   // FunctionDecl
2033   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 11)); // IDNS
2034   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); // StorageClass
2035   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Inline
2036   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // InlineSpecified
2037   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // ExplicitSpecified
2038   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // VirtualAsWritten
2039   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Pure
2040   Abv->Add(BitCodeAbbrevOp(0));                         // HasInheritedProto
2041   Abv->Add(BitCodeAbbrevOp(1));                         // HasWrittenProto
2042   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Deleted
2043   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Trivial
2044   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Defaulted
2045   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // ExplicitlyDefaulted
2046   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // ImplicitReturnZero
2047   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Constexpr
2048   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // UsesSEHTry
2049   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // SkippedBody
2050   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // LateParsed
2051   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); // Linkage
2052   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // LocEnd
2053   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); // TemplateKind
2054   // This Array slurps the rest of the record. Fortunately we want to encode
2055   // (nearly) all the remaining (variable number of) fields in the same way.
2056   //
2057   // This is the function template information if any, then
2058   //         NumParams and Params[] from FunctionDecl, and
2059   //         NumOverriddenMethods, OverriddenMethods[] from CXXMethodDecl.
2060   //
2061   //  Add an AbbrevOp for 'size then elements' and use it here.
2062   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2063   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
2064   DeclCXXMethodAbbrev = Stream.EmitAbbrev(std::move(Abv));
2065
2066   // Abbreviation for EXPR_DECL_REF
2067   Abv = std::make_shared<BitCodeAbbrev>();
2068   Abv->Add(BitCodeAbbrevOp(serialization::EXPR_DECL_REF));
2069   //Stmt
2070   //Expr
2071   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
2072   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //TypeDependent
2073   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //ValueDependent
2074   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //InstantiationDependent
2075   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //UnexpandedParamPack
2076   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetValueKind
2077   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetObjectKind
2078   //DeclRefExpr
2079   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //HasQualifier
2080   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //GetDeclFound
2081   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //ExplicitTemplateArgs
2082   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //HadMultipleCandidates
2083   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
2084                            1)); // RefersToEnclosingVariableOrCapture
2085   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclRef
2086   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Location
2087   DeclRefExprAbbrev = Stream.EmitAbbrev(std::move(Abv));
2088
2089   // Abbreviation for EXPR_INTEGER_LITERAL
2090   Abv = std::make_shared<BitCodeAbbrev>();
2091   Abv->Add(BitCodeAbbrevOp(serialization::EXPR_INTEGER_LITERAL));
2092   //Stmt
2093   //Expr
2094   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
2095   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //TypeDependent
2096   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //ValueDependent
2097   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //InstantiationDependent
2098   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //UnexpandedParamPack
2099   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetValueKind
2100   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetObjectKind
2101   //Integer Literal
2102   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Location
2103   Abv->Add(BitCodeAbbrevOp(32));                      // Bit Width
2104   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Value
2105   IntegerLiteralAbbrev = Stream.EmitAbbrev(std::move(Abv));
2106
2107   // Abbreviation for EXPR_CHARACTER_LITERAL
2108   Abv = std::make_shared<BitCodeAbbrev>();
2109   Abv->Add(BitCodeAbbrevOp(serialization::EXPR_CHARACTER_LITERAL));
2110   //Stmt
2111   //Expr
2112   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
2113   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //TypeDependent
2114   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //ValueDependent
2115   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //InstantiationDependent
2116   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //UnexpandedParamPack
2117   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetValueKind
2118   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetObjectKind
2119   //Character Literal
2120   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // getValue
2121   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Location
2122   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); // getKind
2123   CharacterLiteralAbbrev = Stream.EmitAbbrev(std::move(Abv));
2124
2125   // Abbreviation for EXPR_IMPLICIT_CAST
2126   Abv = std::make_shared<BitCodeAbbrev>();
2127   Abv->Add(BitCodeAbbrevOp(serialization::EXPR_IMPLICIT_CAST));
2128   // Stmt
2129   // Expr
2130   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
2131   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //TypeDependent
2132   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //ValueDependent
2133   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //InstantiationDependent
2134   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //UnexpandedParamPack
2135   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetValueKind
2136   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetObjectKind
2137   // CastExpr
2138   Abv->Add(BitCodeAbbrevOp(0)); // PathSize
2139   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 6)); // CastKind
2140   // ImplicitCastExpr
2141   ExprImplicitCastAbbrev = Stream.EmitAbbrev(std::move(Abv));
2142
2143   Abv = std::make_shared<BitCodeAbbrev>();
2144   Abv->Add(BitCodeAbbrevOp(serialization::DECL_CONTEXT_LEXICAL));
2145   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
2146   DeclContextLexicalAbbrev = Stream.EmitAbbrev(std::move(Abv));
2147
2148   Abv = std::make_shared<BitCodeAbbrev>();
2149   Abv->Add(BitCodeAbbrevOp(serialization::DECL_CONTEXT_VISIBLE));
2150   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
2151   DeclContextVisibleLookupAbbrev = Stream.EmitAbbrev(std::move(Abv));
2152 }
2153
2154 /// isRequiredDecl - Check if this is a "required" Decl, which must be seen by
2155 /// consumers of the AST.
2156 ///
2157 /// Such decls will always be deserialized from the AST file, so we would like
2158 /// this to be as restrictive as possible. Currently the predicate is driven by
2159 /// code generation requirements, if other clients have a different notion of
2160 /// what is "required" then we may have to consider an alternate scheme where
2161 /// clients can iterate over the top-level decls and get information on them,
2162 /// without necessary deserializing them. We could explicitly require such
2163 /// clients to use a separate API call to "realize" the decl. This should be
2164 /// relatively painless since they would presumably only do it for top-level
2165 /// decls.
2166 static bool isRequiredDecl(const Decl *D, ASTContext &Context,
2167                            bool WritingModule) {
2168   // An ObjCMethodDecl is never considered as "required" because its
2169   // implementation container always is.
2170
2171   // File scoped assembly or obj-c or OMP declare target implementation must be
2172   // seen.
2173   if (isa<FileScopeAsmDecl>(D) || isa<ObjCImplDecl>(D) ||
2174       D->hasAttr<OMPDeclareTargetDeclAttr>())
2175     return true;
2176
2177   if (WritingModule && (isa<VarDecl>(D) || isa<ImportDecl>(D))) {
2178     // These declarations are part of the module initializer, and are emitted
2179     // if and when the module is imported, rather than being emitted eagerly.
2180     return false;
2181   }
2182
2183   return Context.DeclMustBeEmitted(D);
2184 }
2185
2186 void ASTWriter::WriteDecl(ASTContext &Context, Decl *D) {
2187   // Determine the ID for this declaration.
2188   serialization::DeclID ID;
2189   assert(!D->isFromASTFile() && "should not be emitting imported decl");
2190   serialization::DeclID &IDR = DeclIDs[D];
2191   if (IDR == 0)
2192     IDR = NextDeclID++;
2193
2194   ID = IDR;
2195
2196   assert(ID >= FirstDeclID && "invalid decl ID");
2197
2198   RecordData Record;
2199   ASTDeclWriter W(*this, Context, Record);
2200
2201   // Build a record for this declaration
2202   W.Visit(D);
2203
2204   // Emit this declaration to the bitstream.
2205   uint64_t Offset = W.Emit(D);
2206
2207   // Record the offset for this declaration
2208   SourceLocation Loc = D->getLocation();
2209   unsigned Index = ID - FirstDeclID;
2210   if (DeclOffsets.size() == Index)
2211     DeclOffsets.push_back(DeclOffset(Loc, Offset));
2212   else if (DeclOffsets.size() < Index) {
2213     // FIXME: Can/should this happen?
2214     DeclOffsets.resize(Index+1);
2215     DeclOffsets[Index].setLocation(Loc);
2216     DeclOffsets[Index].BitOffset = Offset;
2217   } else {
2218     llvm_unreachable("declarations should be emitted in ID order");
2219   }
2220
2221   SourceManager &SM = Context.getSourceManager();
2222   if (Loc.isValid() && SM.isLocalSourceLocation(Loc))
2223     associateDeclWithFile(D, ID);
2224
2225   // Note declarations that should be deserialized eagerly so that we can add
2226   // them to a record in the AST file later.
2227   if (isRequiredDecl(D, Context, WritingModule))
2228     EagerlyDeserializedDecls.push_back(ID);
2229 }
2230
2231 void ASTRecordWriter::AddFunctionDefinition(const FunctionDecl *FD) {
2232   // Switch case IDs are per function body.
2233   Writer->ClearSwitchCaseIDs();
2234
2235   assert(FD->doesThisDeclarationHaveABody());
2236   bool ModulesCodegen = false;
2237   if (Writer->WritingModule && !FD->isDependentContext()) {
2238     // Under -fmodules-codegen, codegen is performed for all defined functions.
2239     // When building a C++ Modules TS module interface unit, a strong definition
2240     // in the module interface is provided by the compilation of that module
2241     // interface unit, not by its users. (Inline functions are still emitted
2242     // in module users.)
2243     ModulesCodegen =
2244         Writer->Context->getLangOpts().ModulesCodegen ||
2245         (Writer->WritingModule->Kind == Module::ModuleInterfaceUnit &&
2246          Writer->Context->GetGVALinkageForFunction(FD) == GVA_StrongExternal);
2247   }
2248   Record->push_back(ModulesCodegen);
2249   if (ModulesCodegen)
2250     Writer->ModularCodegenDecls.push_back(Writer->GetDeclRef(FD));
2251   if (auto *CD = dyn_cast<CXXConstructorDecl>(FD)) {
2252     Record->push_back(CD->getNumCtorInitializers());
2253     if (CD->getNumCtorInitializers())
2254       AddCXXCtorInitializers(
2255           llvm::makeArrayRef(CD->init_begin(), CD->init_end()));
2256   }
2257   AddStmt(FD->getBody());
2258 }