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