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