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