1 //===--- ASTWriterDecl.cpp - Declaration Serialization --------------------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 //  This file implements serialization for Declarations.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "ASTCommon.h"
15 #include "clang/AST/DeclCXX.h"
16 #include "clang/AST/DeclContextInternals.h"
17 #include "clang/AST/DeclTemplate.h"
18 #include "clang/AST/DeclVisitor.h"
19 #include "clang/AST/Expr.h"
20 #include "clang/Basic/SourceManager.h"
21 #include "clang/Serialization/ASTReader.h"
22 #include "clang/Serialization/ASTWriter.h"
23 #include "llvm/Bitcode/BitstreamWriter.h"
24 #include "llvm/Support/ErrorHandling.h"
25 using namespace clang;
26 using namespace serialization;
27 
28 //===----------------------------------------------------------------------===//
29 // Declaration serialization
30 //===----------------------------------------------------------------------===//
31 
32 namespace clang {
33   class ASTDeclWriter : public DeclVisitor<ASTDeclWriter, void> {
34     ASTWriter &Writer;
35     ASTContext &Context;
36     ASTRecordWriter Record;
37 
38     serialization::DeclCode Code;
39     unsigned AbbrevToUse;
40 
41   public:
42     ASTDeclWriter(ASTWriter &Writer, ASTContext &Context,
43                   ASTWriter::RecordDataImpl &Record)
44         : Writer(Writer), Context(Context), Record(Writer, Record),
45           Code((serialization::DeclCode)0), AbbrevToUse(0) {}
46 
47     uint64_t Emit(Decl *D) {
48       if (!Code)
49         llvm::report_fatal_error(StringRef("unexpected declaration kind '") +
50             D->getDeclKindName() + "'");
51       return Record.Emit(Code, AbbrevToUse);
52     }
53 
54     void Visit(Decl *D);
55 
56     void VisitDecl(Decl *D);
57     void VisitPragmaCommentDecl(PragmaCommentDecl *D);
58     void VisitPragmaDetectMismatchDecl(PragmaDetectMismatchDecl *D);
59     void VisitTranslationUnitDecl(TranslationUnitDecl *D);
60     void VisitNamedDecl(NamedDecl *D);
61     void VisitLabelDecl(LabelDecl *LD);
62     void VisitNamespaceDecl(NamespaceDecl *D);
63     void VisitUsingDirectiveDecl(UsingDirectiveDecl *D);
64     void VisitNamespaceAliasDecl(NamespaceAliasDecl *D);
65     void VisitTypeDecl(TypeDecl *D);
66     void VisitTypedefNameDecl(TypedefNameDecl *D);
67     void VisitTypedefDecl(TypedefDecl *D);
68     void VisitTypeAliasDecl(TypeAliasDecl *D);
69     void VisitUnresolvedUsingTypenameDecl(UnresolvedUsingTypenameDecl *D);
70     void VisitTagDecl(TagDecl *D);
71     void VisitEnumDecl(EnumDecl *D);
72     void VisitRecordDecl(RecordDecl *D);
73     void VisitCXXRecordDecl(CXXRecordDecl *D);
74     void VisitClassTemplateSpecializationDecl(
75                                             ClassTemplateSpecializationDecl *D);
76     void VisitClassTemplatePartialSpecializationDecl(
77                                      ClassTemplatePartialSpecializationDecl *D);
78     void VisitVarTemplateSpecializationDecl(VarTemplateSpecializationDecl *D);
79     void VisitVarTemplatePartialSpecializationDecl(
80         VarTemplatePartialSpecializationDecl *D);
81     void VisitClassScopeFunctionSpecializationDecl(
82                                        ClassScopeFunctionSpecializationDecl *D);
83     void VisitTemplateTypeParmDecl(TemplateTypeParmDecl *D);
84     void VisitValueDecl(ValueDecl *D);
85     void VisitEnumConstantDecl(EnumConstantDecl *D);
86     void VisitUnresolvedUsingValueDecl(UnresolvedUsingValueDecl *D);
87     void VisitDeclaratorDecl(DeclaratorDecl *D);
88     void VisitFunctionDecl(FunctionDecl *D);
89     void VisitCXXMethodDecl(CXXMethodDecl *D);
90     void VisitCXXConstructorDecl(CXXConstructorDecl *D);
91     void VisitCXXDestructorDecl(CXXDestructorDecl *D);
92     void VisitCXXConversionDecl(CXXConversionDecl *D);
93     void VisitFieldDecl(FieldDecl *D);
94     void VisitMSPropertyDecl(MSPropertyDecl *D);
95     void VisitIndirectFieldDecl(IndirectFieldDecl *D);
96     void VisitVarDecl(VarDecl *D);
97     void VisitImplicitParamDecl(ImplicitParamDecl *D);
98     void VisitParmVarDecl(ParmVarDecl *D);
99     void VisitNonTypeTemplateParmDecl(NonTypeTemplateParmDecl *D);
100     void VisitTemplateDecl(TemplateDecl *D);
101     void VisitRedeclarableTemplateDecl(RedeclarableTemplateDecl *D);
102     void VisitClassTemplateDecl(ClassTemplateDecl *D);
103     void VisitVarTemplateDecl(VarTemplateDecl *D);
104     void VisitFunctionTemplateDecl(FunctionTemplateDecl *D);
105     void VisitTemplateTemplateParmDecl(TemplateTemplateParmDecl *D);
106     void VisitTypeAliasTemplateDecl(TypeAliasTemplateDecl *D);
107     void VisitUsingDecl(UsingDecl *D);
108     void VisitUsingShadowDecl(UsingShadowDecl *D);
109     void VisitConstructorUsingShadowDecl(ConstructorUsingShadowDecl *D);
110     void VisitLinkageSpecDecl(LinkageSpecDecl *D);
111     void VisitFileScopeAsmDecl(FileScopeAsmDecl *D);
112     void VisitImportDecl(ImportDecl *D);
113     void VisitAccessSpecDecl(AccessSpecDecl *D);
114     void VisitFriendDecl(FriendDecl *D);
115     void VisitFriendTemplateDecl(FriendTemplateDecl *D);
116     void VisitStaticAssertDecl(StaticAssertDecl *D);
117     void VisitBlockDecl(BlockDecl *D);
118     void VisitCapturedDecl(CapturedDecl *D);
119     void VisitEmptyDecl(EmptyDecl *D);
120 
121     void VisitDeclContext(DeclContext *DC);
122     template <typename T> void VisitRedeclarable(Redeclarable<T> *D);
123 
124 
125     // FIXME: Put in the same order is DeclNodes.td?
126     void VisitObjCMethodDecl(ObjCMethodDecl *D);
127     void VisitObjCTypeParamDecl(ObjCTypeParamDecl *D);
128     void VisitObjCContainerDecl(ObjCContainerDecl *D);
129     void VisitObjCInterfaceDecl(ObjCInterfaceDecl *D);
130     void VisitObjCIvarDecl(ObjCIvarDecl *D);
131     void VisitObjCProtocolDecl(ObjCProtocolDecl *D);
132     void VisitObjCAtDefsFieldDecl(ObjCAtDefsFieldDecl *D);
133     void VisitObjCCategoryDecl(ObjCCategoryDecl *D);
134     void VisitObjCImplDecl(ObjCImplDecl *D);
135     void VisitObjCCategoryImplDecl(ObjCCategoryImplDecl *D);
136     void VisitObjCImplementationDecl(ObjCImplementationDecl *D);
137     void VisitObjCCompatibleAliasDecl(ObjCCompatibleAliasDecl *D);
138     void VisitObjCPropertyDecl(ObjCPropertyDecl *D);
139     void VisitObjCPropertyImplDecl(ObjCPropertyImplDecl *D);
140     void VisitOMPThreadPrivateDecl(OMPThreadPrivateDecl *D);
141     void VisitOMPDeclareReductionDecl(OMPDeclareReductionDecl *D);
142     void VisitOMPCapturedExprDecl(OMPCapturedExprDecl *D);
143 
144     /// Add an Objective-C type parameter list to the given record.
145     void AddObjCTypeParamList(ObjCTypeParamList *typeParams) {
146       // Empty type parameter list.
147       if (!typeParams) {
148         Record.push_back(0);
149         return;
150       }
151 
152       Record.push_back(typeParams->size());
153       for (auto typeParam : *typeParams) {
154         Record.AddDeclRef(typeParam);
155       }
156       Record.AddSourceLocation(typeParams->getLAngleLoc());
157       Record.AddSourceLocation(typeParams->getRAngleLoc());
158     }
159 
160     /// Add to the record the first declaration from each module file that
161     /// provides a declaration of D. The intent is to provide a sufficient
162     /// set such that reloading this set will load all current redeclarations.
163     void AddFirstDeclFromEachModule(const Decl *D, bool IncludeLocal) {
164       llvm::MapVector<ModuleFile*, const Decl*> Firsts;
165       // FIXME: We can skip entries that we know are implied by others.
166       for (const Decl *R = D->getMostRecentDecl(); R; R = R->getPreviousDecl()) {
167         if (R->isFromASTFile())
168           Firsts[Writer.Chain->getOwningModuleFile(R)] = R;
169         else if (IncludeLocal)
170           Firsts[nullptr] = R;
171       }
172       for (const auto &F : Firsts)
173         Record.AddDeclRef(F.second);
174     }
175 
176     /// Get the specialization decl from an entry in the specialization list.
177     template <typename EntryType>
178     typename RedeclarableTemplateDecl::SpecEntryTraits<EntryType>::DeclType *
179     getSpecializationDecl(EntryType &T) {
180       return RedeclarableTemplateDecl::SpecEntryTraits<EntryType>::getDecl(&T);
181     }
182 
183     /// Get the list of partial specializations from a template's common ptr.
184     template<typename T>
185     decltype(T::PartialSpecializations) &getPartialSpecializations(T *Common) {
186       return Common->PartialSpecializations;
187     }
188     ArrayRef<Decl> getPartialSpecializations(FunctionTemplateDecl::Common *) {
189       return None;
190     }
191 
192     template<typename DeclTy>
193     void AddTemplateSpecializations(DeclTy *D) {
194       auto *Common = D->getCommonPtr();
195 
196       // If we have any lazy specializations, and the external AST source is
197       // our chained AST reader, we can just write out the DeclIDs. Otherwise,
198       // we need to resolve them to actual declarations.
199       if (Writer.Chain != Writer.Context->getExternalSource() &&
200           Common->LazySpecializations) {
201         D->LoadLazySpecializations();
202         assert(!Common->LazySpecializations);
203       }
204 
205       ArrayRef<DeclID> LazySpecializations;
206       if (auto *LS = Common->LazySpecializations)
207         LazySpecializations = llvm::makeArrayRef(LS + 1, LS[0]);
208 
209       // Add a slot to the record for the number of specializations.
210       unsigned I = Record.size();
211       Record.push_back(0);
212 
213       // AddFirstDeclFromEachModule might trigger deserialization, invalidating
214       // *Specializations iterators.
215       llvm::SmallVector<const Decl*, 16> Specs;
216       for (auto &Entry : Common->Specializations)
217         Specs.push_back(getSpecializationDecl(Entry));
218       for (auto &Entry : getPartialSpecializations(Common))
219         Specs.push_back(getSpecializationDecl(Entry));
220 
221       for (auto *D : Specs) {
222         assert(D->isCanonicalDecl() && "non-canonical decl in set");
223         AddFirstDeclFromEachModule(D, /*IncludeLocal*/true);
224       }
225       Record.append(LazySpecializations.begin(), LazySpecializations.end());
226 
227       // Update the size entry we added earlier.
228       Record[I] = Record.size() - I - 1;
229     }
230 
231     /// Ensure that this template specialization is associated with the specified
232     /// template on reload.
233     void RegisterTemplateSpecialization(const Decl *Template,
234                                         const Decl *Specialization) {
235       Template = Template->getCanonicalDecl();
236 
237       // If the canonical template is local, we'll write out this specialization
238       // when we emit it.
239       // FIXME: We can do the same thing if there is any local declaration of
240       // the template, to avoid emitting an update record.
241       if (!Template->isFromASTFile())
242         return;
243 
244       // We only need to associate the first local declaration of the
245       // specialization. The other declarations will get pulled in by it.
246       if (Writer.getFirstLocalDecl(Specialization) != Specialization)
247         return;
248 
249       Writer.DeclUpdates[Template].push_back(ASTWriter::DeclUpdate(
250           UPD_CXX_ADDED_TEMPLATE_SPECIALIZATION, Specialization));
251     }
252   };
253 }
254 
255 void ASTDeclWriter::Visit(Decl *D) {
256   DeclVisitor<ASTDeclWriter>::Visit(D);
257 
258   // Source locations require array (variable-length) abbreviations.  The
259   // abbreviation infrastructure requires that arrays are encoded last, so
260   // we handle it here in the case of those classes derived from DeclaratorDecl
261   if (DeclaratorDecl *DD = dyn_cast<DeclaratorDecl>(D)) {
262     Record.AddTypeSourceInfo(DD->getTypeSourceInfo());
263   }
264 
265   // Handle FunctionDecl's body here and write it after all other Stmts/Exprs
266   // have been written. We want it last because we will not read it back when
267   // retrieving it from the AST, we'll just lazily set the offset.
268   if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
269     Record.push_back(FD->doesThisDeclarationHaveABody());
270     if (FD->doesThisDeclarationHaveABody())
271       Record.AddFunctionDefinition(FD);
272   }
273 
274   // If this declaration is also a DeclContext, write blocks for the
275   // declarations that lexically stored inside its context and those
276   // declarations that are visible from its context.
277   if (DeclContext *DC = dyn_cast<DeclContext>(D))
278     VisitDeclContext(DC);
279 }
280 
281 void ASTDeclWriter::VisitDecl(Decl *D) {
282   Record.AddDeclRef(cast_or_null<Decl>(D->getDeclContext()));
283   if (D->getDeclContext() != D->getLexicalDeclContext())
284     Record.AddDeclRef(cast_or_null<Decl>(D->getLexicalDeclContext()));
285   else
286     Record.push_back(0);
287   Record.push_back(D->isInvalidDecl());
288   Record.push_back(D->hasAttrs());
289   if (D->hasAttrs())
290     Record.AddAttributes(D->getAttrs());
291   Record.push_back(D->isImplicit());
292   Record.push_back(D->isUsed(false));
293   Record.push_back(D->isReferenced());
294   Record.push_back(D->isTopLevelDeclInObjCContainer());
295   Record.push_back(D->getAccess());
296   Record.push_back(D->isModulePrivate());
297   Record.push_back(Writer.inferSubmoduleIDFromLocation(D->getLocation()));
298 
299   // If this declaration injected a name into a context different from its
300   // lexical context, and that context is an imported namespace, we need to
301   // update its visible declarations to include this name.
302   //
303   // This happens when we instantiate a class with a friend declaration or a
304   // function with a local extern declaration, for instance.
305   //
306   // FIXME: Can we handle this in AddedVisibleDecl instead?
307   if (D->isOutOfLine()) {
308     auto *DC = D->getDeclContext();
309     while (auto *NS = dyn_cast<NamespaceDecl>(DC->getRedeclContext())) {
310       if (!NS->isFromASTFile())
311         break;
312       Writer.UpdatedDeclContexts.insert(NS->getPrimaryContext());
313       if (!NS->isInlineNamespace())
314         break;
315       DC = NS->getParent();
316     }
317   }
318 }
319 
320 void ASTDeclWriter::VisitPragmaCommentDecl(PragmaCommentDecl *D) {
321   StringRef Arg = D->getArg();
322   Record.push_back(Arg.size());
323   VisitDecl(D);
324   Record.AddSourceLocation(D->getLocStart());
325   Record.push_back(D->getCommentKind());
326   Record.AddString(Arg);
327   Code = serialization::DECL_PRAGMA_COMMENT;
328 }
329 
330 void ASTDeclWriter::VisitPragmaDetectMismatchDecl(
331     PragmaDetectMismatchDecl *D) {
332   StringRef Name = D->getName();
333   StringRef Value = D->getValue();
334   Record.push_back(Name.size() + 1 + Value.size());
335   VisitDecl(D);
336   Record.AddSourceLocation(D->getLocStart());
337   Record.AddString(Name);
338   Record.AddString(Value);
339   Code = serialization::DECL_PRAGMA_DETECT_MISMATCH;
340 }
341 
342 void ASTDeclWriter::VisitTranslationUnitDecl(TranslationUnitDecl *D) {
343   llvm_unreachable("Translation units aren't directly serialized");
344 }
345 
346 void ASTDeclWriter::VisitNamedDecl(NamedDecl *D) {
347   VisitDecl(D);
348   Record.AddDeclarationName(D->getDeclName());
349   Record.push_back(needsAnonymousDeclarationNumber(D)
350                        ? Writer.getAnonymousDeclarationNumber(D)
351                        : 0);
352 }
353 
354 void ASTDeclWriter::VisitTypeDecl(TypeDecl *D) {
355   VisitNamedDecl(D);
356   Record.AddSourceLocation(D->getLocStart());
357   Record.AddTypeRef(QualType(D->getTypeForDecl(), 0));
358 }
359 
360 void ASTDeclWriter::VisitTypedefNameDecl(TypedefNameDecl *D) {
361   VisitRedeclarable(D);
362   VisitTypeDecl(D);
363   Record.AddTypeSourceInfo(D->getTypeSourceInfo());
364   Record.push_back(D->isModed());
365   if (D->isModed())
366     Record.AddTypeRef(D->getUnderlyingType());
367 }
368 
369 void ASTDeclWriter::VisitTypedefDecl(TypedefDecl *D) {
370   VisitTypedefNameDecl(D);
371   if (D->getDeclContext() == D->getLexicalDeclContext() &&
372       !D->hasAttrs() &&
373       !D->isImplicit() &&
374       D->getFirstDecl() == D->getMostRecentDecl() &&
375       !D->isInvalidDecl() &&
376       !D->isTopLevelDeclInObjCContainer() &&
377       !D->isModulePrivate() &&
378       !needsAnonymousDeclarationNumber(D) &&
379       D->getDeclName().getNameKind() == DeclarationName::Identifier)
380     AbbrevToUse = Writer.getDeclTypedefAbbrev();
381 
382   Code = serialization::DECL_TYPEDEF;
383 }
384 
385 void ASTDeclWriter::VisitTypeAliasDecl(TypeAliasDecl *D) {
386   VisitTypedefNameDecl(D);
387   Record.AddDeclRef(D->getDescribedAliasTemplate());
388   Code = serialization::DECL_TYPEALIAS;
389 }
390 
391 void ASTDeclWriter::VisitTagDecl(TagDecl *D) {
392   VisitRedeclarable(D);
393   VisitTypeDecl(D);
394   Record.push_back(D->getIdentifierNamespace());
395   Record.push_back((unsigned)D->getTagKind()); // FIXME: stable encoding
396   if (!isa<CXXRecordDecl>(D))
397     Record.push_back(D->isCompleteDefinition());
398   Record.push_back(D->isEmbeddedInDeclarator());
399   Record.push_back(D->isFreeStanding());
400   Record.push_back(D->isCompleteDefinitionRequired());
401   Record.AddSourceRange(D->getBraceRange());
402 
403   if (D->hasExtInfo()) {
404     Record.push_back(1);
405     Record.AddQualifierInfo(*D->getExtInfo());
406   } else if (auto *TD = D->getTypedefNameForAnonDecl()) {
407     Record.push_back(2);
408     Record.AddDeclRef(TD);
409     Record.AddIdentifierRef(TD->getDeclName().getAsIdentifierInfo());
410   } else {
411     Record.push_back(0);
412   }
413 }
414 
415 void ASTDeclWriter::VisitEnumDecl(EnumDecl *D) {
416   VisitTagDecl(D);
417   Record.AddTypeSourceInfo(D->getIntegerTypeSourceInfo());
418   if (!D->getIntegerTypeSourceInfo())
419     Record.AddTypeRef(D->getIntegerType());
420   Record.AddTypeRef(D->getPromotionType());
421   Record.push_back(D->getNumPositiveBits());
422   Record.push_back(D->getNumNegativeBits());
423   Record.push_back(D->isScoped());
424   Record.push_back(D->isScopedUsingClassTag());
425   Record.push_back(D->isFixed());
426   if (MemberSpecializationInfo *MemberInfo = D->getMemberSpecializationInfo()) {
427     Record.AddDeclRef(MemberInfo->getInstantiatedFrom());
428     Record.push_back(MemberInfo->getTemplateSpecializationKind());
429     Record.AddSourceLocation(MemberInfo->getPointOfInstantiation());
430   } else {
431     Record.AddDeclRef(nullptr);
432   }
433 
434   if (D->getDeclContext() == D->getLexicalDeclContext() &&
435       !D->hasAttrs() &&
436       !D->isImplicit() &&
437       !D->isUsed(false) &&
438       !D->hasExtInfo() &&
439       !D->getTypedefNameForAnonDecl() &&
440       D->getFirstDecl() == D->getMostRecentDecl() &&
441       !D->isInvalidDecl() &&
442       !D->isReferenced() &&
443       !D->isTopLevelDeclInObjCContainer() &&
444       D->getAccess() == AS_none &&
445       !D->isModulePrivate() &&
446       !CXXRecordDecl::classofKind(D->getKind()) &&
447       !D->getIntegerTypeSourceInfo() &&
448       !D->getMemberSpecializationInfo() &&
449       !needsAnonymousDeclarationNumber(D) &&
450       D->getDeclName().getNameKind() == DeclarationName::Identifier)
451     AbbrevToUse = Writer.getDeclEnumAbbrev();
452 
453   Code = serialization::DECL_ENUM;
454 }
455 
456 void ASTDeclWriter::VisitRecordDecl(RecordDecl *D) {
457   VisitTagDecl(D);
458   Record.push_back(D->hasFlexibleArrayMember());
459   Record.push_back(D->isAnonymousStructOrUnion());
460   Record.push_back(D->hasObjectMember());
461   Record.push_back(D->hasVolatileMember());
462 
463   if (D->getDeclContext() == D->getLexicalDeclContext() &&
464       !D->hasAttrs() &&
465       !D->isImplicit() &&
466       !D->isUsed(false) &&
467       !D->hasExtInfo() &&
468       !D->getTypedefNameForAnonDecl() &&
469       D->getFirstDecl() == D->getMostRecentDecl() &&
470       !D->isInvalidDecl() &&
471       !D->isReferenced() &&
472       !D->isTopLevelDeclInObjCContainer() &&
473       D->getAccess() == AS_none &&
474       !D->isModulePrivate() &&
475       !CXXRecordDecl::classofKind(D->getKind()) &&
476       !needsAnonymousDeclarationNumber(D) &&
477       D->getDeclName().getNameKind() == DeclarationName::Identifier)
478     AbbrevToUse = Writer.getDeclRecordAbbrev();
479 
480   Code = serialization::DECL_RECORD;
481 }
482 
483 void ASTDeclWriter::VisitValueDecl(ValueDecl *D) {
484   VisitNamedDecl(D);
485   Record.AddTypeRef(D->getType());
486 }
487 
488 void ASTDeclWriter::VisitEnumConstantDecl(EnumConstantDecl *D) {
489   VisitValueDecl(D);
490   Record.push_back(D->getInitExpr()? 1 : 0);
491   if (D->getInitExpr())
492     Record.AddStmt(D->getInitExpr());
493   Record.AddAPSInt(D->getInitVal());
494 
495   Code = serialization::DECL_ENUM_CONSTANT;
496 }
497 
498 void ASTDeclWriter::VisitDeclaratorDecl(DeclaratorDecl *D) {
499   VisitValueDecl(D);
500   Record.AddSourceLocation(D->getInnerLocStart());
501   Record.push_back(D->hasExtInfo());
502   if (D->hasExtInfo())
503     Record.AddQualifierInfo(*D->getExtInfo());
504 }
505 
506 void ASTDeclWriter::VisitFunctionDecl(FunctionDecl *D) {
507   VisitRedeclarable(D);
508   VisitDeclaratorDecl(D);
509   Record.AddDeclarationNameLoc(D->DNLoc, D->getDeclName());
510   Record.push_back(D->getIdentifierNamespace());
511 
512   // FunctionDecl's body is handled last at ASTWriterDecl::Visit,
513   // after everything else is written.
514 
515   Record.push_back((int)D->SClass); // FIXME: stable encoding
516   Record.push_back(D->IsInline);
517   Record.push_back(D->IsInlineSpecified);
518   Record.push_back(D->IsVirtualAsWritten);
519   Record.push_back(D->IsPure);
520   Record.push_back(D->HasInheritedPrototype);
521   Record.push_back(D->HasWrittenPrototype);
522   Record.push_back(D->IsDeleted);
523   Record.push_back(D->IsTrivial);
524   Record.push_back(D->IsDefaulted);
525   Record.push_back(D->IsExplicitlyDefaulted);
526   Record.push_back(D->HasImplicitReturnZero);
527   Record.push_back(D->IsConstexpr);
528   Record.push_back(D->HasSkippedBody);
529   Record.push_back(D->IsLateTemplateParsed);
530   Record.push_back(D->getLinkageInternal());
531   Record.AddSourceLocation(D->getLocEnd());
532 
533   Record.push_back(D->getTemplatedKind());
534   switch (D->getTemplatedKind()) {
535   case FunctionDecl::TK_NonTemplate:
536     break;
537   case FunctionDecl::TK_FunctionTemplate:
538     Record.AddDeclRef(D->getDescribedFunctionTemplate());
539     break;
540   case FunctionDecl::TK_MemberSpecialization: {
541     MemberSpecializationInfo *MemberInfo = D->getMemberSpecializationInfo();
542     Record.AddDeclRef(MemberInfo->getInstantiatedFrom());
543     Record.push_back(MemberInfo->getTemplateSpecializationKind());
544     Record.AddSourceLocation(MemberInfo->getPointOfInstantiation());
545     break;
546   }
547   case FunctionDecl::TK_FunctionTemplateSpecialization: {
548     FunctionTemplateSpecializationInfo *
549       FTSInfo = D->getTemplateSpecializationInfo();
550 
551     RegisterTemplateSpecialization(FTSInfo->getTemplate(), D);
552 
553     Record.AddDeclRef(FTSInfo->getTemplate());
554     Record.push_back(FTSInfo->getTemplateSpecializationKind());
555 
556     // Template arguments.
557     Record.AddTemplateArgumentList(FTSInfo->TemplateArguments);
558 
559     // Template args as written.
560     Record.push_back(FTSInfo->TemplateArgumentsAsWritten != nullptr);
561     if (FTSInfo->TemplateArgumentsAsWritten) {
562       Record.push_back(FTSInfo->TemplateArgumentsAsWritten->NumTemplateArgs);
563       for (int i=0, e = FTSInfo->TemplateArgumentsAsWritten->NumTemplateArgs;
564              i!=e; ++i)
565         Record.AddTemplateArgumentLoc(
566             (*FTSInfo->TemplateArgumentsAsWritten)[i]);
567       Record.AddSourceLocation(FTSInfo->TemplateArgumentsAsWritten->LAngleLoc);
568       Record.AddSourceLocation(FTSInfo->TemplateArgumentsAsWritten->RAngleLoc);
569     }
570 
571     Record.AddSourceLocation(FTSInfo->getPointOfInstantiation());
572 
573     if (D->isCanonicalDecl()) {
574       // Write the template that contains the specializations set. We will
575       // add a FunctionTemplateSpecializationInfo to it when reading.
576       Record.AddDeclRef(FTSInfo->getTemplate()->getCanonicalDecl());
577     }
578     break;
579   }
580   case FunctionDecl::TK_DependentFunctionTemplateSpecialization: {
581     DependentFunctionTemplateSpecializationInfo *
582       DFTSInfo = D->getDependentSpecializationInfo();
583 
584     // Templates.
585     Record.push_back(DFTSInfo->getNumTemplates());
586     for (int i=0, e = DFTSInfo->getNumTemplates(); i != e; ++i)
587       Record.AddDeclRef(DFTSInfo->getTemplate(i));
588 
589     // Templates args.
590     Record.push_back(DFTSInfo->getNumTemplateArgs());
591     for (int i=0, e = DFTSInfo->getNumTemplateArgs(); i != e; ++i)
592       Record.AddTemplateArgumentLoc(DFTSInfo->getTemplateArg(i));
593     Record.AddSourceLocation(DFTSInfo->getLAngleLoc());
594     Record.AddSourceLocation(DFTSInfo->getRAngleLoc());
595     break;
596   }
597   }
598 
599   Record.push_back(D->param_size());
600   for (auto P : D->parameters())
601     Record.AddDeclRef(P);
602   Code = serialization::DECL_FUNCTION;
603 }
604 
605 void ASTDeclWriter::VisitObjCMethodDecl(ObjCMethodDecl *D) {
606   VisitNamedDecl(D);
607   // FIXME: convert to LazyStmtPtr?
608   // Unlike C/C++, method bodies will never be in header files.
609   bool HasBodyStuff = D->getBody() != nullptr     ||
610                       D->getSelfDecl() != nullptr || D->getCmdDecl() != nullptr;
611   Record.push_back(HasBodyStuff);
612   if (HasBodyStuff) {
613     Record.AddStmt(D->getBody());
614     Record.AddDeclRef(D->getSelfDecl());
615     Record.AddDeclRef(D->getCmdDecl());
616   }
617   Record.push_back(D->isInstanceMethod());
618   Record.push_back(D->isVariadic());
619   Record.push_back(D->isPropertyAccessor());
620   Record.push_back(D->isDefined());
621   Record.push_back(D->IsOverriding);
622   Record.push_back(D->HasSkippedBody);
623 
624   Record.push_back(D->IsRedeclaration);
625   Record.push_back(D->HasRedeclaration);
626   if (D->HasRedeclaration) {
627     assert(Context.getObjCMethodRedeclaration(D));
628     Record.AddDeclRef(Context.getObjCMethodRedeclaration(D));
629   }
630 
631   // FIXME: stable encoding for @required/@optional
632   Record.push_back(D->getImplementationControl());
633   // FIXME: stable encoding for in/out/inout/bycopy/byref/oneway/nullability
634   Record.push_back(D->getObjCDeclQualifier());
635   Record.push_back(D->hasRelatedResultType());
636   Record.AddTypeRef(D->getReturnType());
637   Record.AddTypeSourceInfo(D->getReturnTypeSourceInfo());
638   Record.AddSourceLocation(D->getLocEnd());
639   Record.push_back(D->param_size());
640   for (const auto *P : D->parameters())
641     Record.AddDeclRef(P);
642 
643   Record.push_back(D->SelLocsKind);
644   unsigned NumStoredSelLocs = D->getNumStoredSelLocs();
645   SourceLocation *SelLocs = D->getStoredSelLocs();
646   Record.push_back(NumStoredSelLocs);
647   for (unsigned i = 0; i != NumStoredSelLocs; ++i)
648     Record.AddSourceLocation(SelLocs[i]);
649 
650   Code = serialization::DECL_OBJC_METHOD;
651 }
652 
653 void ASTDeclWriter::VisitObjCTypeParamDecl(ObjCTypeParamDecl *D) {
654   VisitTypedefNameDecl(D);
655   Record.push_back(D->Variance);
656   Record.push_back(D->Index);
657   Record.AddSourceLocation(D->VarianceLoc);
658   Record.AddSourceLocation(D->ColonLoc);
659 
660   Code = serialization::DECL_OBJC_TYPE_PARAM;
661 }
662 
663 void ASTDeclWriter::VisitObjCContainerDecl(ObjCContainerDecl *D) {
664   VisitNamedDecl(D);
665   Record.AddSourceLocation(D->getAtStartLoc());
666   Record.AddSourceRange(D->getAtEndRange());
667   // Abstract class (no need to define a stable serialization::DECL code).
668 }
669 
670 void ASTDeclWriter::VisitObjCInterfaceDecl(ObjCInterfaceDecl *D) {
671   VisitRedeclarable(D);
672   VisitObjCContainerDecl(D);
673   Record.AddTypeRef(QualType(D->getTypeForDecl(), 0));
674   AddObjCTypeParamList(D->TypeParamList);
675 
676   Record.push_back(D->isThisDeclarationADefinition());
677   if (D->isThisDeclarationADefinition()) {
678     // Write the DefinitionData
679     ObjCInterfaceDecl::DefinitionData &Data = D->data();
680 
681     Record.AddTypeSourceInfo(D->getSuperClassTInfo());
682     Record.AddSourceLocation(D->getEndOfDefinitionLoc());
683     Record.push_back(Data.HasDesignatedInitializers);
684 
685     // Write out the protocols that are directly referenced by the @interface.
686     Record.push_back(Data.ReferencedProtocols.size());
687     for (const auto *P : D->protocols())
688       Record.AddDeclRef(P);
689     for (const auto &PL : D->protocol_locs())
690       Record.AddSourceLocation(PL);
691 
692     // Write out the protocols that are transitively referenced.
693     Record.push_back(Data.AllReferencedProtocols.size());
694     for (ObjCList<ObjCProtocolDecl>::iterator
695               P = Data.AllReferencedProtocols.begin(),
696            PEnd = Data.AllReferencedProtocols.end();
697          P != PEnd; ++P)
698       Record.AddDeclRef(*P);
699 
700 
701     if (ObjCCategoryDecl *Cat = D->getCategoryListRaw()) {
702       // Ensure that we write out the set of categories for this class.
703       Writer.ObjCClassesWithCategories.insert(D);
704 
705       // Make sure that the categories get serialized.
706       for (; Cat; Cat = Cat->getNextClassCategoryRaw())
707         (void)Writer.GetDeclRef(Cat);
708     }
709   }
710 
711   Code = serialization::DECL_OBJC_INTERFACE;
712 }
713 
714 void ASTDeclWriter::VisitObjCIvarDecl(ObjCIvarDecl *D) {
715   VisitFieldDecl(D);
716   // FIXME: stable encoding for @public/@private/@protected/@package
717   Record.push_back(D->getAccessControl());
718   Record.push_back(D->getSynthesize());
719 
720   if (D->getDeclContext() == D->getLexicalDeclContext() &&
721       !D->hasAttrs() &&
722       !D->isImplicit() &&
723       !D->isUsed(false) &&
724       !D->isInvalidDecl() &&
725       !D->isReferenced() &&
726       !D->isModulePrivate() &&
727       !D->getBitWidth() &&
728       !D->hasExtInfo() &&
729       D->getDeclName())
730     AbbrevToUse = Writer.getDeclObjCIvarAbbrev();
731 
732   Code = serialization::DECL_OBJC_IVAR;
733 }
734 
735 void ASTDeclWriter::VisitObjCProtocolDecl(ObjCProtocolDecl *D) {
736   VisitRedeclarable(D);
737   VisitObjCContainerDecl(D);
738 
739   Record.push_back(D->isThisDeclarationADefinition());
740   if (D->isThisDeclarationADefinition()) {
741     Record.push_back(D->protocol_size());
742     for (const auto *I : D->protocols())
743       Record.AddDeclRef(I);
744     for (const auto &PL : D->protocol_locs())
745       Record.AddSourceLocation(PL);
746   }
747 
748   Code = serialization::DECL_OBJC_PROTOCOL;
749 }
750 
751 void ASTDeclWriter::VisitObjCAtDefsFieldDecl(ObjCAtDefsFieldDecl *D) {
752   VisitFieldDecl(D);
753   Code = serialization::DECL_OBJC_AT_DEFS_FIELD;
754 }
755 
756 void ASTDeclWriter::VisitObjCCategoryDecl(ObjCCategoryDecl *D) {
757   VisitObjCContainerDecl(D);
758   Record.AddSourceLocation(D->getCategoryNameLoc());
759   Record.AddSourceLocation(D->getIvarLBraceLoc());
760   Record.AddSourceLocation(D->getIvarRBraceLoc());
761   Record.AddDeclRef(D->getClassInterface());
762   AddObjCTypeParamList(D->TypeParamList);
763   Record.push_back(D->protocol_size());
764   for (const auto *I : D->protocols())
765     Record.AddDeclRef(I);
766   for (const auto &PL : D->protocol_locs())
767     Record.AddSourceLocation(PL);
768   Code = serialization::DECL_OBJC_CATEGORY;
769 }
770 
771 void ASTDeclWriter::VisitObjCCompatibleAliasDecl(ObjCCompatibleAliasDecl *D) {
772   VisitNamedDecl(D);
773   Record.AddDeclRef(D->getClassInterface());
774   Code = serialization::DECL_OBJC_COMPATIBLE_ALIAS;
775 }
776 
777 void ASTDeclWriter::VisitObjCPropertyDecl(ObjCPropertyDecl *D) {
778   VisitNamedDecl(D);
779   Record.AddSourceLocation(D->getAtLoc());
780   Record.AddSourceLocation(D->getLParenLoc());
781   Record.AddTypeRef(D->getType());
782   Record.AddTypeSourceInfo(D->getTypeSourceInfo());
783   // FIXME: stable encoding
784   Record.push_back((unsigned)D->getPropertyAttributes());
785   Record.push_back((unsigned)D->getPropertyAttributesAsWritten());
786   // FIXME: stable encoding
787   Record.push_back((unsigned)D->getPropertyImplementation());
788   Record.AddDeclarationName(D->getGetterName());
789   Record.AddDeclarationName(D->getSetterName());
790   Record.AddDeclRef(D->getGetterMethodDecl());
791   Record.AddDeclRef(D->getSetterMethodDecl());
792   Record.AddDeclRef(D->getPropertyIvarDecl());
793   Code = serialization::DECL_OBJC_PROPERTY;
794 }
795 
796 void ASTDeclWriter::VisitObjCImplDecl(ObjCImplDecl *D) {
797   VisitObjCContainerDecl(D);
798   Record.AddDeclRef(D->getClassInterface());
799   // Abstract class (no need to define a stable serialization::DECL code).
800 }
801 
802 void ASTDeclWriter::VisitObjCCategoryImplDecl(ObjCCategoryImplDecl *D) {
803   VisitObjCImplDecl(D);
804   Record.AddIdentifierRef(D->getIdentifier());
805   Record.AddSourceLocation(D->getCategoryNameLoc());
806   Code = serialization::DECL_OBJC_CATEGORY_IMPL;
807 }
808 
809 void ASTDeclWriter::VisitObjCImplementationDecl(ObjCImplementationDecl *D) {
810   VisitObjCImplDecl(D);
811   Record.AddDeclRef(D->getSuperClass());
812   Record.AddSourceLocation(D->getSuperClassLoc());
813   Record.AddSourceLocation(D->getIvarLBraceLoc());
814   Record.AddSourceLocation(D->getIvarRBraceLoc());
815   Record.push_back(D->hasNonZeroConstructors());
816   Record.push_back(D->hasDestructors());
817   Record.push_back(D->NumIvarInitializers);
818   if (D->NumIvarInitializers)
819     Record.AddCXXCtorInitializers(
820         llvm::makeArrayRef(D->init_begin(), D->init_end()));
821   Code = serialization::DECL_OBJC_IMPLEMENTATION;
822 }
823 
824 void ASTDeclWriter::VisitObjCPropertyImplDecl(ObjCPropertyImplDecl *D) {
825   VisitDecl(D);
826   Record.AddSourceLocation(D->getLocStart());
827   Record.AddDeclRef(D->getPropertyDecl());
828   Record.AddDeclRef(D->getPropertyIvarDecl());
829   Record.AddSourceLocation(D->getPropertyIvarDeclLoc());
830   Record.AddStmt(D->getGetterCXXConstructor());
831   Record.AddStmt(D->getSetterCXXAssignment());
832   Code = serialization::DECL_OBJC_PROPERTY_IMPL;
833 }
834 
835 void ASTDeclWriter::VisitFieldDecl(FieldDecl *D) {
836   VisitDeclaratorDecl(D);
837   Record.push_back(D->isMutable());
838   if (D->InitStorage.getInt() == FieldDecl::ISK_BitWidthOrNothing &&
839       D->InitStorage.getPointer() == nullptr) {
840     Record.push_back(0);
841   } else if (D->InitStorage.getInt() == FieldDecl::ISK_CapturedVLAType) {
842     Record.push_back(D->InitStorage.getInt() + 1);
843     Record.AddTypeRef(
844         QualType(static_cast<Type *>(D->InitStorage.getPointer()), 0));
845   } else {
846     Record.push_back(D->InitStorage.getInt() + 1);
847     Record.AddStmt(static_cast<Expr *>(D->InitStorage.getPointer()));
848   }
849   if (!D->getDeclName())
850     Record.AddDeclRef(Context.getInstantiatedFromUnnamedFieldDecl(D));
851 
852   if (D->getDeclContext() == D->getLexicalDeclContext() &&
853       !D->hasAttrs() &&
854       !D->isImplicit() &&
855       !D->isUsed(false) &&
856       !D->isInvalidDecl() &&
857       !D->isReferenced() &&
858       !D->isTopLevelDeclInObjCContainer() &&
859       !D->isModulePrivate() &&
860       !D->getBitWidth() &&
861       !D->hasInClassInitializer() &&
862       !D->hasExtInfo() &&
863       !ObjCIvarDecl::classofKind(D->getKind()) &&
864       !ObjCAtDefsFieldDecl::classofKind(D->getKind()) &&
865       D->getDeclName())
866     AbbrevToUse = Writer.getDeclFieldAbbrev();
867 
868   Code = serialization::DECL_FIELD;
869 }
870 
871 void ASTDeclWriter::VisitMSPropertyDecl(MSPropertyDecl *D) {
872   VisitDeclaratorDecl(D);
873   Record.AddIdentifierRef(D->getGetterId());
874   Record.AddIdentifierRef(D->getSetterId());
875   Code = serialization::DECL_MS_PROPERTY;
876 }
877 
878 void ASTDeclWriter::VisitIndirectFieldDecl(IndirectFieldDecl *D) {
879   VisitValueDecl(D);
880   Record.push_back(D->getChainingSize());
881 
882   for (const auto *P : D->chain())
883     Record.AddDeclRef(P);
884   Code = serialization::DECL_INDIRECTFIELD;
885 }
886 
887 void ASTDeclWriter::VisitVarDecl(VarDecl *D) {
888   VisitRedeclarable(D);
889   VisitDeclaratorDecl(D);
890   Record.push_back(D->getStorageClass());
891   Record.push_back(D->getTSCSpec());
892   Record.push_back(D->getInitStyle());
893   if (!isa<ParmVarDecl>(D)) {
894     Record.push_back(D->isExceptionVariable());
895     Record.push_back(D->isNRVOVariable());
896     Record.push_back(D->isCXXForRangeDecl());
897     Record.push_back(D->isARCPseudoStrong());
898     Record.push_back(D->isInline());
899     Record.push_back(D->isInlineSpecified());
900     Record.push_back(D->isConstexpr());
901     Record.push_back(D->isInitCapture());
902     Record.push_back(D->isPreviousDeclInSameBlockScope());
903   }
904   Record.push_back(D->getLinkageInternal());
905 
906   if (D->getInit()) {
907     Record.push_back(!D->isInitKnownICE() ? 1 : (D->isInitICE() ? 3 : 2));
908     Record.AddStmt(D->getInit());
909   } else {
910     Record.push_back(0);
911   }
912 
913   enum {
914     VarNotTemplate = 0, VarTemplate, StaticDataMemberSpecialization
915   };
916   if (VarTemplateDecl *TemplD = D->getDescribedVarTemplate()) {
917     Record.push_back(VarTemplate);
918     Record.AddDeclRef(TemplD);
919   } else if (MemberSpecializationInfo *SpecInfo
920                = D->getMemberSpecializationInfo()) {
921     Record.push_back(StaticDataMemberSpecialization);
922     Record.AddDeclRef(SpecInfo->getInstantiatedFrom());
923     Record.push_back(SpecInfo->getTemplateSpecializationKind());
924     Record.AddSourceLocation(SpecInfo->getPointOfInstantiation());
925   } else {
926     Record.push_back(VarNotTemplate);
927   }
928 
929   if (D->getDeclContext() == D->getLexicalDeclContext() &&
930       !D->hasAttrs() &&
931       !D->isImplicit() &&
932       !D->isUsed(false) &&
933       !D->isInvalidDecl() &&
934       !D->isReferenced() &&
935       !D->isTopLevelDeclInObjCContainer() &&
936       D->getAccess() == AS_none &&
937       !D->isModulePrivate() &&
938       !needsAnonymousDeclarationNumber(D) &&
939       D->getDeclName().getNameKind() == DeclarationName::Identifier &&
940       !D->hasExtInfo() &&
941       D->getFirstDecl() == D->getMostRecentDecl() &&
942       D->getInitStyle() == VarDecl::CInit &&
943       D->getInit() == nullptr &&
944       !isa<ParmVarDecl>(D) &&
945       !isa<VarTemplateSpecializationDecl>(D) &&
946       !D->isInline() &&
947       !D->isConstexpr() &&
948       !D->isInitCapture() &&
949       !D->isPreviousDeclInSameBlockScope() &&
950       !D->getMemberSpecializationInfo())
951     AbbrevToUse = Writer.getDeclVarAbbrev();
952 
953   Code = serialization::DECL_VAR;
954 }
955 
956 void ASTDeclWriter::VisitImplicitParamDecl(ImplicitParamDecl *D) {
957   VisitVarDecl(D);
958   Code = serialization::DECL_IMPLICIT_PARAM;
959 }
960 
961 void ASTDeclWriter::VisitParmVarDecl(ParmVarDecl *D) {
962   VisitVarDecl(D);
963   Record.push_back(D->isObjCMethodParameter());
964   Record.push_back(D->getFunctionScopeDepth());
965   Record.push_back(D->getFunctionScopeIndex());
966   Record.push_back(D->getObjCDeclQualifier()); // FIXME: stable encoding
967   Record.push_back(D->isKNRPromoted());
968   Record.push_back(D->hasInheritedDefaultArg());
969   Record.push_back(D->hasUninstantiatedDefaultArg());
970   if (D->hasUninstantiatedDefaultArg())
971     Record.AddStmt(D->getUninstantiatedDefaultArg());
972   Code = serialization::DECL_PARM_VAR;
973 
974   assert(!D->isARCPseudoStrong()); // can be true of ImplicitParamDecl
975 
976   // If the assumptions about the DECL_PARM_VAR abbrev are true, use it.  Here
977   // we dynamically check for the properties that we optimize for, but don't
978   // know are true of all PARM_VAR_DECLs.
979   if (D->getDeclContext() == D->getLexicalDeclContext() &&
980       !D->hasAttrs() &&
981       !D->hasExtInfo() &&
982       !D->isImplicit() &&
983       !D->isUsed(false) &&
984       !D->isInvalidDecl() &&
985       !D->isReferenced() &&
986       D->getAccess() == AS_none &&
987       !D->isModulePrivate() &&
988       D->getStorageClass() == 0 &&
989       D->getInitStyle() == VarDecl::CInit && // Can params have anything else?
990       D->getFunctionScopeDepth() == 0 &&
991       D->getObjCDeclQualifier() == 0 &&
992       !D->isKNRPromoted() &&
993       !D->hasInheritedDefaultArg() &&
994       D->getInit() == nullptr &&
995       !D->hasUninstantiatedDefaultArg())  // No default expr.
996     AbbrevToUse = Writer.getDeclParmVarAbbrev();
997 
998   // Check things we know are true of *every* PARM_VAR_DECL, which is more than
999   // just us assuming it.
1000   assert(!D->getTSCSpec() && "PARM_VAR_DECL can't use TLS");
1001   assert(D->getAccess() == AS_none && "PARM_VAR_DECL can't be public/private");
1002   assert(!D->isExceptionVariable() && "PARM_VAR_DECL can't be exception var");
1003   assert(D->getPreviousDecl() == nullptr && "PARM_VAR_DECL can't be redecl");
1004   assert(!D->isStaticDataMember() &&
1005          "PARM_VAR_DECL can't be static data member");
1006 }
1007 
1008 void ASTDeclWriter::VisitFileScopeAsmDecl(FileScopeAsmDecl *D) {
1009   VisitDecl(D);
1010   Record.AddStmt(D->getAsmString());
1011   Record.AddSourceLocation(D->getRParenLoc());
1012   Code = serialization::DECL_FILE_SCOPE_ASM;
1013 }
1014 
1015 void ASTDeclWriter::VisitEmptyDecl(EmptyDecl *D) {
1016   VisitDecl(D);
1017   Code = serialization::DECL_EMPTY;
1018 }
1019 
1020 void ASTDeclWriter::VisitBlockDecl(BlockDecl *D) {
1021   VisitDecl(D);
1022   Record.AddStmt(D->getBody());
1023   Record.AddTypeSourceInfo(D->getSignatureAsWritten());
1024   Record.push_back(D->param_size());
1025   for (ParmVarDecl *P : D->parameters())
1026     Record.AddDeclRef(P);
1027   Record.push_back(D->isVariadic());
1028   Record.push_back(D->blockMissingReturnType());
1029   Record.push_back(D->isConversionFromLambda());
1030   Record.push_back(D->capturesCXXThis());
1031   Record.push_back(D->getNumCaptures());
1032   for (const auto &capture : D->captures()) {
1033     Record.AddDeclRef(capture.getVariable());
1034 
1035     unsigned flags = 0;
1036     if (capture.isByRef()) flags |= 1;
1037     if (capture.isNested()) flags |= 2;
1038     if (capture.hasCopyExpr()) flags |= 4;
1039     Record.push_back(flags);
1040 
1041     if (capture.hasCopyExpr()) Record.AddStmt(capture.getCopyExpr());
1042   }
1043 
1044   Code = serialization::DECL_BLOCK;
1045 }
1046 
1047 void ASTDeclWriter::VisitCapturedDecl(CapturedDecl *CD) {
1048   Record.push_back(CD->getNumParams());
1049   VisitDecl(CD);
1050   Record.push_back(CD->getContextParamPosition());
1051   Record.push_back(CD->isNothrow() ? 1 : 0);
1052   // Body is stored by VisitCapturedStmt.
1053   for (unsigned I = 0; I < CD->getNumParams(); ++I)
1054     Record.AddDeclRef(CD->getParam(I));
1055   Code = serialization::DECL_CAPTURED;
1056 }
1057 
1058 void ASTDeclWriter::VisitLinkageSpecDecl(LinkageSpecDecl *D) {
1059   VisitDecl(D);
1060   Record.push_back(D->getLanguage());
1061   Record.AddSourceLocation(D->getExternLoc());
1062   Record.AddSourceLocation(D->getRBraceLoc());
1063   Code = serialization::DECL_LINKAGE_SPEC;
1064 }
1065 
1066 void ASTDeclWriter::VisitLabelDecl(LabelDecl *D) {
1067   VisitNamedDecl(D);
1068   Record.AddSourceLocation(D->getLocStart());
1069   Code = serialization::DECL_LABEL;
1070 }
1071 
1072 
1073 void ASTDeclWriter::VisitNamespaceDecl(NamespaceDecl *D) {
1074   VisitRedeclarable(D);
1075   VisitNamedDecl(D);
1076   Record.push_back(D->isInline());
1077   Record.AddSourceLocation(D->getLocStart());
1078   Record.AddSourceLocation(D->getRBraceLoc());
1079 
1080   if (D->isOriginalNamespace())
1081     Record.AddDeclRef(D->getAnonymousNamespace());
1082   Code = serialization::DECL_NAMESPACE;
1083 
1084   if (Writer.hasChain() && D->isAnonymousNamespace() &&
1085       D == D->getMostRecentDecl()) {
1086     // This is a most recent reopening of the anonymous namespace. If its parent
1087     // is in a previous PCH (or is the TU), mark that parent for update, because
1088     // the original namespace always points to the latest re-opening of its
1089     // anonymous namespace.
1090     Decl *Parent = cast<Decl>(
1091         D->getParent()->getRedeclContext()->getPrimaryContext());
1092     if (Parent->isFromASTFile() || isa<TranslationUnitDecl>(Parent)) {
1093       Writer.DeclUpdates[Parent].push_back(
1094           ASTWriter::DeclUpdate(UPD_CXX_ADDED_ANONYMOUS_NAMESPACE, D));
1095     }
1096   }
1097 }
1098 
1099 void ASTDeclWriter::VisitNamespaceAliasDecl(NamespaceAliasDecl *D) {
1100   VisitRedeclarable(D);
1101   VisitNamedDecl(D);
1102   Record.AddSourceLocation(D->getNamespaceLoc());
1103   Record.AddSourceLocation(D->getTargetNameLoc());
1104   Record.AddNestedNameSpecifierLoc(D->getQualifierLoc());
1105   Record.AddDeclRef(D->getNamespace());
1106   Code = serialization::DECL_NAMESPACE_ALIAS;
1107 }
1108 
1109 void ASTDeclWriter::VisitUsingDecl(UsingDecl *D) {
1110   VisitNamedDecl(D);
1111   Record.AddSourceLocation(D->getUsingLoc());
1112   Record.AddNestedNameSpecifierLoc(D->getQualifierLoc());
1113   Record.AddDeclarationNameLoc(D->DNLoc, D->getDeclName());
1114   Record.AddDeclRef(D->FirstUsingShadow.getPointer());
1115   Record.push_back(D->hasTypename());
1116   Record.AddDeclRef(Context.getInstantiatedFromUsingDecl(D));
1117   Code = serialization::DECL_USING;
1118 }
1119 
1120 void ASTDeclWriter::VisitUsingShadowDecl(UsingShadowDecl *D) {
1121   VisitRedeclarable(D);
1122   VisitNamedDecl(D);
1123   Record.AddDeclRef(D->getTargetDecl());
1124   Record.AddDeclRef(D->UsingOrNextShadow);
1125   Record.AddDeclRef(Context.getInstantiatedFromUsingShadowDecl(D));
1126   Code = serialization::DECL_USING_SHADOW;
1127 }
1128 
1129 void ASTDeclWriter::VisitConstructorUsingShadowDecl(
1130     ConstructorUsingShadowDecl *D) {
1131   VisitUsingShadowDecl(D);
1132   Record.AddDeclRef(D->NominatedBaseClassShadowDecl);
1133   Record.AddDeclRef(D->ConstructedBaseClassShadowDecl);
1134   Record.push_back(D->IsVirtual);
1135   Code = serialization::DECL_CONSTRUCTOR_USING_SHADOW;
1136 }
1137 
1138 void ASTDeclWriter::VisitUsingDirectiveDecl(UsingDirectiveDecl *D) {
1139   VisitNamedDecl(D);
1140   Record.AddSourceLocation(D->getUsingLoc());
1141   Record.AddSourceLocation(D->getNamespaceKeyLocation());
1142   Record.AddNestedNameSpecifierLoc(D->getQualifierLoc());
1143   Record.AddDeclRef(D->getNominatedNamespace());
1144   Record.AddDeclRef(dyn_cast<Decl>(D->getCommonAncestor()));
1145   Code = serialization::DECL_USING_DIRECTIVE;
1146 }
1147 
1148 void ASTDeclWriter::VisitUnresolvedUsingValueDecl(UnresolvedUsingValueDecl *D) {
1149   VisitValueDecl(D);
1150   Record.AddSourceLocation(D->getUsingLoc());
1151   Record.AddNestedNameSpecifierLoc(D->getQualifierLoc());
1152   Record.AddDeclarationNameLoc(D->DNLoc, D->getDeclName());
1153   Code = serialization::DECL_UNRESOLVED_USING_VALUE;
1154 }
1155 
1156 void ASTDeclWriter::VisitUnresolvedUsingTypenameDecl(
1157                                                UnresolvedUsingTypenameDecl *D) {
1158   VisitTypeDecl(D);
1159   Record.AddSourceLocation(D->getTypenameLoc());
1160   Record.AddNestedNameSpecifierLoc(D->getQualifierLoc());
1161   Code = serialization::DECL_UNRESOLVED_USING_TYPENAME;
1162 }
1163 
1164 void ASTDeclWriter::VisitCXXRecordDecl(CXXRecordDecl *D) {
1165   VisitRecordDecl(D);
1166 
1167   enum {
1168     CXXRecNotTemplate = 0, CXXRecTemplate, CXXRecMemberSpecialization
1169   };
1170   if (ClassTemplateDecl *TemplD = D->getDescribedClassTemplate()) {
1171     Record.push_back(CXXRecTemplate);
1172     Record.AddDeclRef(TemplD);
1173   } else if (MemberSpecializationInfo *MSInfo
1174                = D->getMemberSpecializationInfo()) {
1175     Record.push_back(CXXRecMemberSpecialization);
1176     Record.AddDeclRef(MSInfo->getInstantiatedFrom());
1177     Record.push_back(MSInfo->getTemplateSpecializationKind());
1178     Record.AddSourceLocation(MSInfo->getPointOfInstantiation());
1179   } else {
1180     Record.push_back(CXXRecNotTemplate);
1181   }
1182 
1183   Record.push_back(D->isThisDeclarationADefinition());
1184   if (D->isThisDeclarationADefinition())
1185     Record.AddCXXDefinitionData(D);
1186 
1187   // Store (what we currently believe to be) the key function to avoid
1188   // deserializing every method so we can compute it.
1189   if (D->IsCompleteDefinition)
1190     Record.AddDeclRef(Context.getCurrentKeyFunction(D));
1191 
1192   Code = serialization::DECL_CXX_RECORD;
1193 }
1194 
1195 void ASTDeclWriter::VisitCXXMethodDecl(CXXMethodDecl *D) {
1196   VisitFunctionDecl(D);
1197   if (D->isCanonicalDecl()) {
1198     Record.push_back(D->size_overridden_methods());
1199     for (CXXMethodDecl::method_iterator
1200            I = D->begin_overridden_methods(), E = D->end_overridden_methods();
1201            I != E; ++I)
1202       Record.AddDeclRef(*I);
1203   } else {
1204     // We only need to record overridden methods once for the canonical decl.
1205     Record.push_back(0);
1206   }
1207 
1208   if (D->getDeclContext() == D->getLexicalDeclContext() &&
1209       D->getFirstDecl() == D->getMostRecentDecl() &&
1210       !D->isInvalidDecl() &&
1211       !D->hasAttrs() &&
1212       !D->isTopLevelDeclInObjCContainer() &&
1213       D->getDeclName().getNameKind() == DeclarationName::Identifier &&
1214       !D->hasExtInfo() &&
1215       !D->hasInheritedPrototype() &&
1216       D->hasWrittenPrototype())
1217     AbbrevToUse = Writer.getDeclCXXMethodAbbrev();
1218 
1219   Code = serialization::DECL_CXX_METHOD;
1220 }
1221 
1222 void ASTDeclWriter::VisitCXXConstructorDecl(CXXConstructorDecl *D) {
1223   if (auto Inherited = D->getInheritedConstructor()) {
1224     Record.AddDeclRef(Inherited.getShadowDecl());
1225     Record.AddDeclRef(Inherited.getConstructor());
1226     Code = serialization::DECL_CXX_INHERITED_CONSTRUCTOR;
1227   } else {
1228     Code = serialization::DECL_CXX_CONSTRUCTOR;
1229   }
1230 
1231   VisitCXXMethodDecl(D);
1232 
1233   Record.push_back(D->IsExplicitSpecified);
1234 
1235   Code = D->isInheritingConstructor()
1236              ? serialization::DECL_CXX_INHERITED_CONSTRUCTOR
1237              : serialization::DECL_CXX_CONSTRUCTOR;
1238 }
1239 
1240 void ASTDeclWriter::VisitCXXDestructorDecl(CXXDestructorDecl *D) {
1241   VisitCXXMethodDecl(D);
1242 
1243   Record.AddDeclRef(D->getOperatorDelete());
1244 
1245   Code = serialization::DECL_CXX_DESTRUCTOR;
1246 }
1247 
1248 void ASTDeclWriter::VisitCXXConversionDecl(CXXConversionDecl *D) {
1249   VisitCXXMethodDecl(D);
1250   Record.push_back(D->IsExplicitSpecified);
1251   Code = serialization::DECL_CXX_CONVERSION;
1252 }
1253 
1254 void ASTDeclWriter::VisitImportDecl(ImportDecl *D) {
1255   VisitDecl(D);
1256   Record.push_back(Writer.getSubmoduleID(D->getImportedModule()));
1257   ArrayRef<SourceLocation> IdentifierLocs = D->getIdentifierLocs();
1258   Record.push_back(!IdentifierLocs.empty());
1259   if (IdentifierLocs.empty()) {
1260     Record.AddSourceLocation(D->getLocEnd());
1261     Record.push_back(1);
1262   } else {
1263     for (unsigned I = 0, N = IdentifierLocs.size(); I != N; ++I)
1264       Record.AddSourceLocation(IdentifierLocs[I]);
1265     Record.push_back(IdentifierLocs.size());
1266   }
1267   // Note: the number of source locations must always be the last element in
1268   // the record.
1269   Code = serialization::DECL_IMPORT;
1270 }
1271 
1272 void ASTDeclWriter::VisitAccessSpecDecl(AccessSpecDecl *D) {
1273   VisitDecl(D);
1274   Record.AddSourceLocation(D->getColonLoc());
1275   Code = serialization::DECL_ACCESS_SPEC;
1276 }
1277 
1278 void ASTDeclWriter::VisitFriendDecl(FriendDecl *D) {
1279   // Record the number of friend type template parameter lists here
1280   // so as to simplify memory allocation during deserialization.
1281   Record.push_back(D->NumTPLists);
1282   VisitDecl(D);
1283   bool hasFriendDecl = D->Friend.is<NamedDecl*>();
1284   Record.push_back(hasFriendDecl);
1285   if (hasFriendDecl)
1286     Record.AddDeclRef(D->getFriendDecl());
1287   else
1288     Record.AddTypeSourceInfo(D->getFriendType());
1289   for (unsigned i = 0; i < D->NumTPLists; ++i)
1290     Record.AddTemplateParameterList(D->getFriendTypeTemplateParameterList(i));
1291   Record.AddDeclRef(D->getNextFriend());
1292   Record.push_back(D->UnsupportedFriend);
1293   Record.AddSourceLocation(D->FriendLoc);
1294   Code = serialization::DECL_FRIEND;
1295 }
1296 
1297 void ASTDeclWriter::VisitFriendTemplateDecl(FriendTemplateDecl *D) {
1298   VisitDecl(D);
1299   Record.push_back(D->getNumTemplateParameters());
1300   for (unsigned i = 0, e = D->getNumTemplateParameters(); i != e; ++i)
1301     Record.AddTemplateParameterList(D->getTemplateParameterList(i));
1302   Record.push_back(D->getFriendDecl() != nullptr);
1303   if (D->getFriendDecl())
1304     Record.AddDeclRef(D->getFriendDecl());
1305   else
1306     Record.AddTypeSourceInfo(D->getFriendType());
1307   Record.AddSourceLocation(D->getFriendLoc());
1308   Code = serialization::DECL_FRIEND_TEMPLATE;
1309 }
1310 
1311 void ASTDeclWriter::VisitTemplateDecl(TemplateDecl *D) {
1312   VisitNamedDecl(D);
1313 
1314   Record.AddDeclRef(D->getTemplatedDecl());
1315   Record.AddTemplateParameterList(D->getTemplateParameters());
1316 }
1317 
1318 void ASTDeclWriter::VisitRedeclarableTemplateDecl(RedeclarableTemplateDecl *D) {
1319   VisitRedeclarable(D);
1320 
1321   // Emit data to initialize CommonOrPrev before VisitTemplateDecl so that
1322   // getCommonPtr() can be used while this is still initializing.
1323   if (D->isFirstDecl()) {
1324     // This declaration owns the 'common' pointer, so serialize that data now.
1325     Record.AddDeclRef(D->getInstantiatedFromMemberTemplate());
1326     if (D->getInstantiatedFromMemberTemplate())
1327       Record.push_back(D->isMemberSpecialization());
1328   }
1329 
1330   VisitTemplateDecl(D);
1331   Record.push_back(D->getIdentifierNamespace());
1332 }
1333 
1334 void ASTDeclWriter::VisitClassTemplateDecl(ClassTemplateDecl *D) {
1335   VisitRedeclarableTemplateDecl(D);
1336 
1337   if (D->isFirstDecl())
1338     AddTemplateSpecializations(D);
1339   Code = serialization::DECL_CLASS_TEMPLATE;
1340 }
1341 
1342 void ASTDeclWriter::VisitClassTemplateSpecializationDecl(
1343                                            ClassTemplateSpecializationDecl *D) {
1344   RegisterTemplateSpecialization(D->getSpecializedTemplate(), D);
1345 
1346   VisitCXXRecordDecl(D);
1347 
1348   llvm::PointerUnion<ClassTemplateDecl *,
1349                      ClassTemplatePartialSpecializationDecl *> InstFrom
1350     = D->getSpecializedTemplateOrPartial();
1351   if (Decl *InstFromD = InstFrom.dyn_cast<ClassTemplateDecl *>()) {
1352     Record.AddDeclRef(InstFromD);
1353   } else {
1354     Record.AddDeclRef(InstFrom.get<ClassTemplatePartialSpecializationDecl *>());
1355     Record.AddTemplateArgumentList(&D->getTemplateInstantiationArgs());
1356   }
1357 
1358   Record.AddTemplateArgumentList(&D->getTemplateArgs());
1359   Record.AddSourceLocation(D->getPointOfInstantiation());
1360   Record.push_back(D->getSpecializationKind());
1361   Record.push_back(D->isCanonicalDecl());
1362 
1363   if (D->isCanonicalDecl()) {
1364     // When reading, we'll add it to the folding set of the following template.
1365     Record.AddDeclRef(D->getSpecializedTemplate()->getCanonicalDecl());
1366   }
1367 
1368   // Explicit info.
1369   Record.AddTypeSourceInfo(D->getTypeAsWritten());
1370   if (D->getTypeAsWritten()) {
1371     Record.AddSourceLocation(D->getExternLoc());
1372     Record.AddSourceLocation(D->getTemplateKeywordLoc());
1373   }
1374 
1375   Code = serialization::DECL_CLASS_TEMPLATE_SPECIALIZATION;
1376 }
1377 
1378 void ASTDeclWriter::VisitClassTemplatePartialSpecializationDecl(
1379                                     ClassTemplatePartialSpecializationDecl *D) {
1380   VisitClassTemplateSpecializationDecl(D);
1381 
1382   Record.AddTemplateParameterList(D->getTemplateParameters());
1383   Record.AddASTTemplateArgumentListInfo(D->getTemplateArgsAsWritten());
1384 
1385   // These are read/set from/to the first declaration.
1386   if (D->getPreviousDecl() == nullptr) {
1387     Record.AddDeclRef(D->getInstantiatedFromMember());
1388     Record.push_back(D->isMemberSpecialization());
1389   }
1390 
1391   Code = serialization::DECL_CLASS_TEMPLATE_PARTIAL_SPECIALIZATION;
1392 }
1393 
1394 void ASTDeclWriter::VisitVarTemplateDecl(VarTemplateDecl *D) {
1395   VisitRedeclarableTemplateDecl(D);
1396 
1397   if (D->isFirstDecl())
1398     AddTemplateSpecializations(D);
1399   Code = serialization::DECL_VAR_TEMPLATE;
1400 }
1401 
1402 void ASTDeclWriter::VisitVarTemplateSpecializationDecl(
1403     VarTemplateSpecializationDecl *D) {
1404   RegisterTemplateSpecialization(D->getSpecializedTemplate(), D);
1405 
1406   VisitVarDecl(D);
1407 
1408   llvm::PointerUnion<VarTemplateDecl *, VarTemplatePartialSpecializationDecl *>
1409   InstFrom = D->getSpecializedTemplateOrPartial();
1410   if (Decl *InstFromD = InstFrom.dyn_cast<VarTemplateDecl *>()) {
1411     Record.AddDeclRef(InstFromD);
1412   } else {
1413     Record.AddDeclRef(InstFrom.get<VarTemplatePartialSpecializationDecl *>());
1414     Record.AddTemplateArgumentList(&D->getTemplateInstantiationArgs());
1415   }
1416 
1417   // Explicit info.
1418   Record.AddTypeSourceInfo(D->getTypeAsWritten());
1419   if (D->getTypeAsWritten()) {
1420     Record.AddSourceLocation(D->getExternLoc());
1421     Record.AddSourceLocation(D->getTemplateKeywordLoc());
1422   }
1423 
1424   Record.AddTemplateArgumentList(&D->getTemplateArgs());
1425   Record.AddSourceLocation(D->getPointOfInstantiation());
1426   Record.push_back(D->getSpecializationKind());
1427   Record.push_back(D->isCanonicalDecl());
1428 
1429   if (D->isCanonicalDecl()) {
1430     // When reading, we'll add it to the folding set of the following template.
1431     Record.AddDeclRef(D->getSpecializedTemplate()->getCanonicalDecl());
1432   }
1433 
1434   Code = serialization::DECL_VAR_TEMPLATE_SPECIALIZATION;
1435 }
1436 
1437 void ASTDeclWriter::VisitVarTemplatePartialSpecializationDecl(
1438     VarTemplatePartialSpecializationDecl *D) {
1439   VisitVarTemplateSpecializationDecl(D);
1440 
1441   Record.AddTemplateParameterList(D->getTemplateParameters());
1442   Record.AddASTTemplateArgumentListInfo(D->getTemplateArgsAsWritten());
1443 
1444   // These are read/set from/to the first declaration.
1445   if (D->getPreviousDecl() == nullptr) {
1446     Record.AddDeclRef(D->getInstantiatedFromMember());
1447     Record.push_back(D->isMemberSpecialization());
1448   }
1449 
1450   Code = serialization::DECL_VAR_TEMPLATE_PARTIAL_SPECIALIZATION;
1451 }
1452 
1453 void ASTDeclWriter::VisitClassScopeFunctionSpecializationDecl(
1454                                     ClassScopeFunctionSpecializationDecl *D) {
1455   VisitDecl(D);
1456   Record.AddDeclRef(D->getSpecialization());
1457   Code = serialization::DECL_CLASS_SCOPE_FUNCTION_SPECIALIZATION;
1458 }
1459 
1460 
1461 void ASTDeclWriter::VisitFunctionTemplateDecl(FunctionTemplateDecl *D) {
1462   VisitRedeclarableTemplateDecl(D);
1463 
1464   if (D->isFirstDecl())
1465     AddTemplateSpecializations(D);
1466   Code = serialization::DECL_FUNCTION_TEMPLATE;
1467 }
1468 
1469 void ASTDeclWriter::VisitTemplateTypeParmDecl(TemplateTypeParmDecl *D) {
1470   VisitTypeDecl(D);
1471 
1472   Record.push_back(D->wasDeclaredWithTypename());
1473 
1474   bool OwnsDefaultArg = D->hasDefaultArgument() &&
1475                         !D->defaultArgumentWasInherited();
1476   Record.push_back(OwnsDefaultArg);
1477   if (OwnsDefaultArg)
1478     Record.AddTypeSourceInfo(D->getDefaultArgumentInfo());
1479 
1480   Code = serialization::DECL_TEMPLATE_TYPE_PARM;
1481 }
1482 
1483 void ASTDeclWriter::VisitNonTypeTemplateParmDecl(NonTypeTemplateParmDecl *D) {
1484   // For an expanded parameter pack, record the number of expansion types here
1485   // so that it's easier for deserialization to allocate the right amount of
1486   // memory.
1487   if (D->isExpandedParameterPack())
1488     Record.push_back(D->getNumExpansionTypes());
1489 
1490   VisitDeclaratorDecl(D);
1491   // TemplateParmPosition.
1492   Record.push_back(D->getDepth());
1493   Record.push_back(D->getPosition());
1494 
1495   if (D->isExpandedParameterPack()) {
1496     for (unsigned I = 0, N = D->getNumExpansionTypes(); I != N; ++I) {
1497       Record.AddTypeRef(D->getExpansionType(I));
1498       Record.AddTypeSourceInfo(D->getExpansionTypeSourceInfo(I));
1499     }
1500 
1501     Code = serialization::DECL_EXPANDED_NON_TYPE_TEMPLATE_PARM_PACK;
1502   } else {
1503     // Rest of NonTypeTemplateParmDecl.
1504     Record.push_back(D->isParameterPack());
1505     bool OwnsDefaultArg = D->hasDefaultArgument() &&
1506                           !D->defaultArgumentWasInherited();
1507     Record.push_back(OwnsDefaultArg);
1508     if (OwnsDefaultArg)
1509       Record.AddStmt(D->getDefaultArgument());
1510     Code = serialization::DECL_NON_TYPE_TEMPLATE_PARM;
1511   }
1512 }
1513 
1514 void ASTDeclWriter::VisitTemplateTemplateParmDecl(TemplateTemplateParmDecl *D) {
1515   // For an expanded parameter pack, record the number of expansion types here
1516   // so that it's easier for deserialization to allocate the right amount of
1517   // memory.
1518   if (D->isExpandedParameterPack())
1519     Record.push_back(D->getNumExpansionTemplateParameters());
1520 
1521   VisitTemplateDecl(D);
1522   // TemplateParmPosition.
1523   Record.push_back(D->getDepth());
1524   Record.push_back(D->getPosition());
1525 
1526   if (D->isExpandedParameterPack()) {
1527     for (unsigned I = 0, N = D->getNumExpansionTemplateParameters();
1528          I != N; ++I)
1529       Record.AddTemplateParameterList(D->getExpansionTemplateParameters(I));
1530     Code = serialization::DECL_EXPANDED_TEMPLATE_TEMPLATE_PARM_PACK;
1531   } else {
1532     // Rest of TemplateTemplateParmDecl.
1533     Record.push_back(D->isParameterPack());
1534     bool OwnsDefaultArg = D->hasDefaultArgument() &&
1535                           !D->defaultArgumentWasInherited();
1536     Record.push_back(OwnsDefaultArg);
1537     if (OwnsDefaultArg)
1538       Record.AddTemplateArgumentLoc(D->getDefaultArgument());
1539     Code = serialization::DECL_TEMPLATE_TEMPLATE_PARM;
1540   }
1541 }
1542 
1543 void ASTDeclWriter::VisitTypeAliasTemplateDecl(TypeAliasTemplateDecl *D) {
1544   VisitRedeclarableTemplateDecl(D);
1545   Code = serialization::DECL_TYPE_ALIAS_TEMPLATE;
1546 }
1547 
1548 void ASTDeclWriter::VisitStaticAssertDecl(StaticAssertDecl *D) {
1549   VisitDecl(D);
1550   Record.AddStmt(D->getAssertExpr());
1551   Record.push_back(D->isFailed());
1552   Record.AddStmt(D->getMessage());
1553   Record.AddSourceLocation(D->getRParenLoc());
1554   Code = serialization::DECL_STATIC_ASSERT;
1555 }
1556 
1557 /// \brief Emit the DeclContext part of a declaration context decl.
1558 void ASTDeclWriter::VisitDeclContext(DeclContext *DC) {
1559   Record.AddOffset(Writer.WriteDeclContextLexicalBlock(Context, DC));
1560   Record.AddOffset(Writer.WriteDeclContextVisibleBlock(Context, DC));
1561 }
1562 
1563 const Decl *ASTWriter::getFirstLocalDecl(const Decl *D) {
1564   assert(IsLocalDecl(D) && "expected a local declaration");
1565 
1566   const Decl *Canon = D->getCanonicalDecl();
1567   if (IsLocalDecl(Canon))
1568     return Canon;
1569 
1570   const Decl *&CacheEntry = FirstLocalDeclCache[Canon];
1571   if (CacheEntry)
1572     return CacheEntry;
1573 
1574   for (const Decl *Redecl = D; Redecl; Redecl = Redecl->getPreviousDecl())
1575     if (IsLocalDecl(Redecl))
1576       D = Redecl;
1577   return CacheEntry = D;
1578 }
1579 
1580 template <typename T>
1581 void ASTDeclWriter::VisitRedeclarable(Redeclarable<T> *D) {
1582   T *First = D->getFirstDecl();
1583   T *MostRecent = First->getMostRecentDecl();
1584   T *DAsT = static_cast<T *>(D);
1585   if (MostRecent != First) {
1586     assert(isRedeclarableDeclKind(DAsT->getKind()) &&
1587            "Not considered redeclarable?");
1588 
1589     Record.AddDeclRef(First);
1590 
1591     // Write out a list of local redeclarations of this declaration if it's the
1592     // first local declaration in the chain.
1593     const Decl *FirstLocal = Writer.getFirstLocalDecl(DAsT);
1594     if (DAsT == FirstLocal) {
1595       // Emit a list of all imported first declarations so that we can be sure
1596       // that all redeclarations visible to this module are before D in the
1597       // redecl chain.
1598       unsigned I = Record.size();
1599       Record.push_back(0);
1600       if (Writer.Chain)
1601         AddFirstDeclFromEachModule(DAsT, /*IncludeLocal*/false);
1602       // This is the number of imported first declarations + 1.
1603       Record[I] = Record.size() - I;
1604 
1605       // Collect the set of local redeclarations of this declaration, from
1606       // newest to oldest.
1607       ASTWriter::RecordData LocalRedecls;
1608       ASTRecordWriter LocalRedeclWriter(Record, LocalRedecls);
1609       for (const Decl *Prev = FirstLocal->getMostRecentDecl();
1610            Prev != FirstLocal; Prev = Prev->getPreviousDecl())
1611         if (!Prev->isFromASTFile())
1612           LocalRedeclWriter.AddDeclRef(Prev);
1613 
1614       // If we have any redecls, write them now as a separate record preceding
1615       // the declaration itself.
1616       if (LocalRedecls.empty())
1617         Record.push_back(0);
1618       else
1619         Record.AddOffset(LocalRedeclWriter.Emit(LOCAL_REDECLARATIONS));
1620     } else {
1621       Record.push_back(0);
1622       Record.AddDeclRef(FirstLocal);
1623     }
1624 
1625     // Make sure that we serialize both the previous and the most-recent
1626     // declarations, which (transitively) ensures that all declarations in the
1627     // chain get serialized.
1628     //
1629     // FIXME: This is not correct; when we reach an imported declaration we
1630     // won't emit its previous declaration.
1631     (void)Writer.GetDeclRef(D->getPreviousDecl());
1632     (void)Writer.GetDeclRef(MostRecent);
1633   } else {
1634     // We use the sentinel value 0 to indicate an only declaration.
1635     Record.push_back(0);
1636   }
1637 }
1638 
1639 void ASTDeclWriter::VisitOMPThreadPrivateDecl(OMPThreadPrivateDecl *D) {
1640   Record.push_back(D->varlist_size());
1641   VisitDecl(D);
1642   for (auto *I : D->varlists())
1643     Record.AddStmt(I);
1644   Code = serialization::DECL_OMP_THREADPRIVATE;
1645 }
1646 
1647 void ASTDeclWriter::VisitOMPDeclareReductionDecl(OMPDeclareReductionDecl *D) {
1648   VisitValueDecl(D);
1649   Record.AddSourceLocation(D->getLocStart());
1650   Record.AddStmt(D->getCombiner());
1651   Record.AddStmt(D->getInitializer());
1652   Record.AddDeclRef(D->getPrevDeclInScope());
1653   Code = serialization::DECL_OMP_DECLARE_REDUCTION;
1654 }
1655 
1656 void ASTDeclWriter::VisitOMPCapturedExprDecl(OMPCapturedExprDecl *D) {
1657   VisitVarDecl(D);
1658   Code = serialization::DECL_OMP_CAPTUREDEXPR;
1659 }
1660 
1661 //===----------------------------------------------------------------------===//
1662 // ASTWriter Implementation
1663 //===----------------------------------------------------------------------===//
1664 
1665 void ASTWriter::WriteDeclAbbrevs() {
1666   using namespace llvm;
1667 
1668   BitCodeAbbrev *Abv;
1669 
1670   // Abbreviation for DECL_FIELD
1671   Abv = new BitCodeAbbrev();
1672   Abv->Add(BitCodeAbbrevOp(serialization::DECL_FIELD));
1673   // Decl
1674   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclContext
1675   Abv->Add(BitCodeAbbrevOp(0));                       // LexicalDeclContext
1676   Abv->Add(BitCodeAbbrevOp(0));                       // isInvalidDecl
1677   Abv->Add(BitCodeAbbrevOp(0));                       // HasAttrs
1678   Abv->Add(BitCodeAbbrevOp(0));                       // isImplicit
1679   Abv->Add(BitCodeAbbrevOp(0));                       // isUsed
1680   Abv->Add(BitCodeAbbrevOp(0));                       // isReferenced
1681   Abv->Add(BitCodeAbbrevOp(0));                   // TopLevelDeclInObjCContainer
1682   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2));  // AccessSpecifier
1683   Abv->Add(BitCodeAbbrevOp(0));                       // ModulePrivate
1684   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // SubmoduleID
1685   // NamedDecl
1686   Abv->Add(BitCodeAbbrevOp(0));                       // NameKind = Identifier
1687   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Name
1688   Abv->Add(BitCodeAbbrevOp(0));                       // AnonDeclNumber
1689   // ValueDecl
1690   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
1691   // DeclaratorDecl
1692   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // InnerStartLoc
1693   Abv->Add(BitCodeAbbrevOp(0));                       // hasExtInfo
1694   // FieldDecl
1695   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isMutable
1696   Abv->Add(BitCodeAbbrevOp(0));                       //getBitWidth
1697   // Type Source Info
1698   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1699   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1700   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // TypeLoc
1701   DeclFieldAbbrev = Stream.EmitAbbrev(Abv);
1702 
1703   // Abbreviation for DECL_OBJC_IVAR
1704   Abv = new BitCodeAbbrev();
1705   Abv->Add(BitCodeAbbrevOp(serialization::DECL_OBJC_IVAR));
1706   // Decl
1707   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclContext
1708   Abv->Add(BitCodeAbbrevOp(0));                       // LexicalDeclContext
1709   Abv->Add(BitCodeAbbrevOp(0));                       // isInvalidDecl
1710   Abv->Add(BitCodeAbbrevOp(0));                       // HasAttrs
1711   Abv->Add(BitCodeAbbrevOp(0));                       // isImplicit
1712   Abv->Add(BitCodeAbbrevOp(0));                       // isUsed
1713   Abv->Add(BitCodeAbbrevOp(0));                       // isReferenced
1714   Abv->Add(BitCodeAbbrevOp(0));                   // TopLevelDeclInObjCContainer
1715   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2));  // AccessSpecifier
1716   Abv->Add(BitCodeAbbrevOp(0));                       // ModulePrivate
1717   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // SubmoduleID
1718   // NamedDecl
1719   Abv->Add(BitCodeAbbrevOp(0));                       // NameKind = Identifier
1720   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Name
1721   Abv->Add(BitCodeAbbrevOp(0));                       // AnonDeclNumber
1722   // ValueDecl
1723   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
1724   // DeclaratorDecl
1725   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // InnerStartLoc
1726   Abv->Add(BitCodeAbbrevOp(0));                       // hasExtInfo
1727   // FieldDecl
1728   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isMutable
1729   Abv->Add(BitCodeAbbrevOp(0));                       //getBitWidth
1730   // ObjC Ivar
1731   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // getAccessControl
1732   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // getSynthesize
1733   // Type Source Info
1734   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1735   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1736   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // TypeLoc
1737   DeclObjCIvarAbbrev = Stream.EmitAbbrev(Abv);
1738 
1739   // Abbreviation for DECL_ENUM
1740   Abv = new BitCodeAbbrev();
1741   Abv->Add(BitCodeAbbrevOp(serialization::DECL_ENUM));
1742   // Redeclarable
1743   Abv->Add(BitCodeAbbrevOp(0));                       // No redeclaration
1744   // Decl
1745   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclContext
1746   Abv->Add(BitCodeAbbrevOp(0));                       // LexicalDeclContext
1747   Abv->Add(BitCodeAbbrevOp(0));                       // isInvalidDecl
1748   Abv->Add(BitCodeAbbrevOp(0));                       // HasAttrs
1749   Abv->Add(BitCodeAbbrevOp(0));                       // isImplicit
1750   Abv->Add(BitCodeAbbrevOp(0));                       // isUsed
1751   Abv->Add(BitCodeAbbrevOp(0));                       // isReferenced
1752   Abv->Add(BitCodeAbbrevOp(0));                   // TopLevelDeclInObjCContainer
1753   Abv->Add(BitCodeAbbrevOp(AS_none));                 // C++ AccessSpecifier
1754   Abv->Add(BitCodeAbbrevOp(0));                       // ModulePrivate
1755   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // SubmoduleID
1756   // NamedDecl
1757   Abv->Add(BitCodeAbbrevOp(0));                       // NameKind = Identifier
1758   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Name
1759   Abv->Add(BitCodeAbbrevOp(0));                       // AnonDeclNumber
1760   // TypeDecl
1761   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Source Location
1762   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type Ref
1763   // TagDecl
1764   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // IdentifierNamespace
1765   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // getTagKind
1766   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isCompleteDefinition
1767   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // EmbeddedInDeclarator
1768   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsFreeStanding
1769   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsCompleteDefinitionRequired
1770   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // SourceLocation
1771   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // SourceLocation
1772   Abv->Add(BitCodeAbbrevOp(0));                         // ExtInfoKind
1773   // EnumDecl
1774   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // AddTypeRef
1775   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // IntegerType
1776   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // getPromotionType
1777   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // getNumPositiveBits
1778   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // getNumNegativeBits
1779   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isScoped
1780   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isScopedUsingClassTag
1781   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isFixed
1782   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // InstantiatedMembEnum
1783   // DC
1784   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // LexicalOffset
1785   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // VisibleOffset
1786   DeclEnumAbbrev = Stream.EmitAbbrev(Abv);
1787 
1788   // Abbreviation for DECL_RECORD
1789   Abv = new BitCodeAbbrev();
1790   Abv->Add(BitCodeAbbrevOp(serialization::DECL_RECORD));
1791   // Redeclarable
1792   Abv->Add(BitCodeAbbrevOp(0));                       // No redeclaration
1793   // Decl
1794   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclContext
1795   Abv->Add(BitCodeAbbrevOp(0));                       // LexicalDeclContext
1796   Abv->Add(BitCodeAbbrevOp(0));                       // isInvalidDecl
1797   Abv->Add(BitCodeAbbrevOp(0));                       // HasAttrs
1798   Abv->Add(BitCodeAbbrevOp(0));                       // isImplicit
1799   Abv->Add(BitCodeAbbrevOp(0));                       // isUsed
1800   Abv->Add(BitCodeAbbrevOp(0));                       // isReferenced
1801   Abv->Add(BitCodeAbbrevOp(0));                   // TopLevelDeclInObjCContainer
1802   Abv->Add(BitCodeAbbrevOp(AS_none));                 // C++ AccessSpecifier
1803   Abv->Add(BitCodeAbbrevOp(0));                       // ModulePrivate
1804   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // SubmoduleID
1805   // NamedDecl
1806   Abv->Add(BitCodeAbbrevOp(0));                       // NameKind = Identifier
1807   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Name
1808   Abv->Add(BitCodeAbbrevOp(0));                       // AnonDeclNumber
1809   // TypeDecl
1810   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Source Location
1811   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type Ref
1812   // TagDecl
1813   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // IdentifierNamespace
1814   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // getTagKind
1815   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isCompleteDefinition
1816   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // EmbeddedInDeclarator
1817   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsFreeStanding
1818   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsCompleteDefinitionRequired
1819   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // SourceLocation
1820   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // SourceLocation
1821   Abv->Add(BitCodeAbbrevOp(0));                         // ExtInfoKind
1822   // RecordDecl
1823   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // FlexibleArrayMember
1824   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // AnonymousStructUnion
1825   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // hasObjectMember
1826   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // hasVolatileMember
1827   // DC
1828   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // LexicalOffset
1829   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // VisibleOffset
1830   DeclRecordAbbrev = Stream.EmitAbbrev(Abv);
1831 
1832   // Abbreviation for DECL_PARM_VAR
1833   Abv = new BitCodeAbbrev();
1834   Abv->Add(BitCodeAbbrevOp(serialization::DECL_PARM_VAR));
1835   // Redeclarable
1836   Abv->Add(BitCodeAbbrevOp(0));                       // No redeclaration
1837   // Decl
1838   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclContext
1839   Abv->Add(BitCodeAbbrevOp(0));                       // LexicalDeclContext
1840   Abv->Add(BitCodeAbbrevOp(0));                       // isInvalidDecl
1841   Abv->Add(BitCodeAbbrevOp(0));                       // HasAttrs
1842   Abv->Add(BitCodeAbbrevOp(0));                       // isImplicit
1843   Abv->Add(BitCodeAbbrevOp(0));                       // isUsed
1844   Abv->Add(BitCodeAbbrevOp(0));                       // isReferenced
1845   Abv->Add(BitCodeAbbrevOp(0));                   // TopLevelDeclInObjCContainer
1846   Abv->Add(BitCodeAbbrevOp(AS_none));                 // C++ AccessSpecifier
1847   Abv->Add(BitCodeAbbrevOp(0));                       // ModulePrivate
1848   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // SubmoduleID
1849   // NamedDecl
1850   Abv->Add(BitCodeAbbrevOp(0));                       // NameKind = Identifier
1851   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Name
1852   Abv->Add(BitCodeAbbrevOp(0));                       // AnonDeclNumber
1853   // ValueDecl
1854   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
1855   // DeclaratorDecl
1856   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // InnerStartLoc
1857   Abv->Add(BitCodeAbbrevOp(0));                       // hasExtInfo
1858   // VarDecl
1859   Abv->Add(BitCodeAbbrevOp(0));                       // StorageClass
1860   Abv->Add(BitCodeAbbrevOp(0));                       // getTSCSpec
1861   Abv->Add(BitCodeAbbrevOp(0));                       // hasCXXDirectInitializer
1862   Abv->Add(BitCodeAbbrevOp(0));                       // Linkage
1863   Abv->Add(BitCodeAbbrevOp(0));                       // HasInit
1864   Abv->Add(BitCodeAbbrevOp(0));                   // HasMemberSpecializationInfo
1865   // ParmVarDecl
1866   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsObjCMethodParameter
1867   Abv->Add(BitCodeAbbrevOp(0));                       // ScopeDepth
1868   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // ScopeIndex
1869   Abv->Add(BitCodeAbbrevOp(0));                       // ObjCDeclQualifier
1870   Abv->Add(BitCodeAbbrevOp(0));                       // KNRPromoted
1871   Abv->Add(BitCodeAbbrevOp(0));                       // HasInheritedDefaultArg
1872   Abv->Add(BitCodeAbbrevOp(0));                   // HasUninstantiatedDefaultArg
1873   // Type Source Info
1874   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1875   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1876   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // TypeLoc
1877   DeclParmVarAbbrev = Stream.EmitAbbrev(Abv);
1878 
1879   // Abbreviation for DECL_TYPEDEF
1880   Abv = new BitCodeAbbrev();
1881   Abv->Add(BitCodeAbbrevOp(serialization::DECL_TYPEDEF));
1882   // Redeclarable
1883   Abv->Add(BitCodeAbbrevOp(0));                       // No redeclaration
1884   // Decl
1885   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclContext
1886   Abv->Add(BitCodeAbbrevOp(0));                       // LexicalDeclContext
1887   Abv->Add(BitCodeAbbrevOp(0));                       // isInvalidDecl
1888   Abv->Add(BitCodeAbbrevOp(0));                       // HasAttrs
1889   Abv->Add(BitCodeAbbrevOp(0));                       // isImplicit
1890   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isUsed
1891   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isReferenced
1892   Abv->Add(BitCodeAbbrevOp(0));                   // TopLevelDeclInObjCContainer
1893   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2)); // C++ AccessSpecifier
1894   Abv->Add(BitCodeAbbrevOp(0));                       // ModulePrivate
1895   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // SubmoduleID
1896   // NamedDecl
1897   Abv->Add(BitCodeAbbrevOp(0));                       // NameKind = Identifier
1898   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Name
1899   Abv->Add(BitCodeAbbrevOp(0));                       // AnonDeclNumber
1900   // TypeDecl
1901   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Source Location
1902   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type Ref
1903   // TypedefDecl
1904   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1905   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // TypeLoc
1906   DeclTypedefAbbrev = Stream.EmitAbbrev(Abv);
1907 
1908   // Abbreviation for DECL_VAR
1909   Abv = new BitCodeAbbrev();
1910   Abv->Add(BitCodeAbbrevOp(serialization::DECL_VAR));
1911   // Redeclarable
1912   Abv->Add(BitCodeAbbrevOp(0));                       // No redeclaration
1913   // Decl
1914   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclContext
1915   Abv->Add(BitCodeAbbrevOp(0));                       // LexicalDeclContext
1916   Abv->Add(BitCodeAbbrevOp(0));                       // isInvalidDecl
1917   Abv->Add(BitCodeAbbrevOp(0));                       // HasAttrs
1918   Abv->Add(BitCodeAbbrevOp(0));                       // isImplicit
1919   Abv->Add(BitCodeAbbrevOp(0));                       // isUsed
1920   Abv->Add(BitCodeAbbrevOp(0));                       // isReferenced
1921   Abv->Add(BitCodeAbbrevOp(0));                   // TopLevelDeclInObjCContainer
1922   Abv->Add(BitCodeAbbrevOp(AS_none));                 // C++ AccessSpecifier
1923   Abv->Add(BitCodeAbbrevOp(0));                       // ModulePrivate
1924   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // SubmoduleID
1925   // NamedDecl
1926   Abv->Add(BitCodeAbbrevOp(0));                       // NameKind = Identifier
1927   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Name
1928   Abv->Add(BitCodeAbbrevOp(0));                       // AnonDeclNumber
1929   // ValueDecl
1930   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
1931   // DeclaratorDecl
1932   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // InnerStartLoc
1933   Abv->Add(BitCodeAbbrevOp(0));                       // hasExtInfo
1934   // VarDecl
1935   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // StorageClass
1936   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2)); // getTSCSpec
1937   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // CXXDirectInitializer
1938   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isExceptionVariable
1939   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isNRVOVariable
1940   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isCXXForRangeDecl
1941   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isARCPseudoStrong
1942   Abv->Add(BitCodeAbbrevOp(0));                         // isInline
1943   Abv->Add(BitCodeAbbrevOp(0));                         // isInlineSpecified
1944   Abv->Add(BitCodeAbbrevOp(0));                         // isConstexpr
1945   Abv->Add(BitCodeAbbrevOp(0));                         // isInitCapture
1946   Abv->Add(BitCodeAbbrevOp(0));                         // isPrevDeclInSameScope
1947   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); // Linkage
1948   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // HasInit
1949   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // HasMemberSpecInfo
1950   // Type Source Info
1951   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1952   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1953   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // TypeLoc
1954   DeclVarAbbrev = Stream.EmitAbbrev(Abv);
1955 
1956   // Abbreviation for DECL_CXX_METHOD
1957   Abv = new BitCodeAbbrev();
1958   Abv->Add(BitCodeAbbrevOp(serialization::DECL_CXX_METHOD));
1959   // RedeclarableDecl
1960   Abv->Add(BitCodeAbbrevOp(0));                         // CanonicalDecl
1961   // Decl
1962   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // DeclContext
1963   Abv->Add(BitCodeAbbrevOp(0));                         // LexicalDeclContext
1964   Abv->Add(BitCodeAbbrevOp(0));                         // Invalid
1965   Abv->Add(BitCodeAbbrevOp(0));                         // HasAttrs
1966   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Implicit
1967   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Used
1968   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Referenced
1969   Abv->Add(BitCodeAbbrevOp(0));                         // InObjCContainer
1970   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2)); // Access
1971   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // ModulePrivate
1972   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // SubmoduleID
1973   // NamedDecl
1974   Abv->Add(BitCodeAbbrevOp(DeclarationName::Identifier)); // NameKind
1975   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // Identifier
1976   Abv->Add(BitCodeAbbrevOp(0));                         // AnonDeclNumber
1977   // ValueDecl
1978   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // Type
1979   // DeclaratorDecl
1980   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // InnerLocStart
1981   Abv->Add(BitCodeAbbrevOp(0));                         // HasExtInfo
1982   // FunctionDecl
1983   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 11)); // IDNS
1984   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); // StorageClass
1985   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Inline
1986   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // InlineSpecified
1987   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // VirtualAsWritten
1988   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Pure
1989   Abv->Add(BitCodeAbbrevOp(0));                         // HasInheritedProto
1990   Abv->Add(BitCodeAbbrevOp(1));                         // HasWrittenProto
1991   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Deleted
1992   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Trivial
1993   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Defaulted
1994   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // ExplicitlyDefaulted
1995   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // ImplicitReturnZero
1996   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Constexpr
1997   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // SkippedBody
1998   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // LateParsed
1999   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); // Linkage
2000   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // LocEnd
2001   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); // TemplateKind
2002   // This Array slurps the rest of the record. Fortunately we want to encode
2003   // (nearly) all the remaining (variable number of) fields in the same way.
2004   //
2005   // This is the function template information if any, then
2006   //         NumParams and Params[] from FunctionDecl, and
2007   //         NumOverriddenMethods, OverriddenMethods[] from CXXMethodDecl.
2008   //
2009   //  Add an AbbrevOp for 'size then elements' and use it here.
2010   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2011   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
2012   DeclCXXMethodAbbrev = Stream.EmitAbbrev(Abv);
2013 
2014   // Abbreviation for EXPR_DECL_REF
2015   Abv = new BitCodeAbbrev();
2016   Abv->Add(BitCodeAbbrevOp(serialization::EXPR_DECL_REF));
2017   //Stmt
2018   //Expr
2019   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
2020   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //TypeDependent
2021   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //ValueDependent
2022   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //InstantiationDependent
2023   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //UnexpandedParamPack
2024   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetValueKind
2025   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetObjectKind
2026   //DeclRefExpr
2027   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //HasQualifier
2028   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //GetDeclFound
2029   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //ExplicitTemplateArgs
2030   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //HadMultipleCandidates
2031   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
2032                            1)); // RefersToEnclosingVariableOrCapture
2033   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclRef
2034   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Location
2035   DeclRefExprAbbrev = Stream.EmitAbbrev(Abv);
2036 
2037   // Abbreviation for EXPR_INTEGER_LITERAL
2038   Abv = new BitCodeAbbrev();
2039   Abv->Add(BitCodeAbbrevOp(serialization::EXPR_INTEGER_LITERAL));
2040   //Stmt
2041   //Expr
2042   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
2043   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //TypeDependent
2044   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //ValueDependent
2045   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //InstantiationDependent
2046   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //UnexpandedParamPack
2047   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetValueKind
2048   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetObjectKind
2049   //Integer Literal
2050   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Location
2051   Abv->Add(BitCodeAbbrevOp(32));                      // Bit Width
2052   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Value
2053   IntegerLiteralAbbrev = Stream.EmitAbbrev(Abv);
2054 
2055   // Abbreviation for EXPR_CHARACTER_LITERAL
2056   Abv = new BitCodeAbbrev();
2057   Abv->Add(BitCodeAbbrevOp(serialization::EXPR_CHARACTER_LITERAL));
2058   //Stmt
2059   //Expr
2060   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
2061   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //TypeDependent
2062   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //ValueDependent
2063   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //InstantiationDependent
2064   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //UnexpandedParamPack
2065   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetValueKind
2066   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetObjectKind
2067   //Character Literal
2068   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // getValue
2069   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Location
2070   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); // getKind
2071   CharacterLiteralAbbrev = Stream.EmitAbbrev(Abv);
2072 
2073   // Abbreviation for EXPR_IMPLICIT_CAST
2074   Abv = new BitCodeAbbrev();
2075   Abv->Add(BitCodeAbbrevOp(serialization::EXPR_IMPLICIT_CAST));
2076   // Stmt
2077   // Expr
2078   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
2079   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //TypeDependent
2080   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //ValueDependent
2081   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //InstantiationDependent
2082   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //UnexpandedParamPack
2083   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetValueKind
2084   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetObjectKind
2085   // CastExpr
2086   Abv->Add(BitCodeAbbrevOp(0)); // PathSize
2087   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 6)); // CastKind
2088   // ImplicitCastExpr
2089   ExprImplicitCastAbbrev = Stream.EmitAbbrev(Abv);
2090 
2091   Abv = new BitCodeAbbrev();
2092   Abv->Add(BitCodeAbbrevOp(serialization::DECL_CONTEXT_LEXICAL));
2093   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
2094   DeclContextLexicalAbbrev = Stream.EmitAbbrev(Abv);
2095 
2096   Abv = new BitCodeAbbrev();
2097   Abv->Add(BitCodeAbbrevOp(serialization::DECL_CONTEXT_VISIBLE));
2098   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
2099   DeclContextVisibleLookupAbbrev = Stream.EmitAbbrev(Abv);
2100 }
2101 
2102 /// isRequiredDecl - Check if this is a "required" Decl, which must be seen by
2103 /// consumers of the AST.
2104 ///
2105 /// Such decls will always be deserialized from the AST file, so we would like
2106 /// this to be as restrictive as possible. Currently the predicate is driven by
2107 /// code generation requirements, if other clients have a different notion of
2108 /// what is "required" then we may have to consider an alternate scheme where
2109 /// clients can iterate over the top-level decls and get information on them,
2110 /// without necessary deserializing them. We could explicitly require such
2111 /// clients to use a separate API call to "realize" the decl. This should be
2112 /// relatively painless since they would presumably only do it for top-level
2113 /// decls.
2114 static bool isRequiredDecl(const Decl *D, ASTContext &Context,
2115                            bool WritingModule) {
2116   // An ObjCMethodDecl is never considered as "required" because its
2117   // implementation container always is.
2118 
2119   // File scoped assembly or obj-c or OMP declare target implementation must be
2120   // seen.
2121   if (isa<FileScopeAsmDecl>(D) || isa<ObjCImplDecl>(D) ||
2122       D->hasAttr<OMPDeclareTargetDeclAttr>())
2123     return true;
2124 
2125   // ImportDecl is used by codegen to determine the set of imported modules to
2126   // search for inputs for automatic linking; include it if it has a semantic
2127   // effect.
2128   if (isa<ImportDecl>(D) && !WritingModule)
2129     return true;
2130 
2131   return Context.DeclMustBeEmitted(D);
2132 }
2133 
2134 void ASTWriter::WriteDecl(ASTContext &Context, Decl *D) {
2135   // Determine the ID for this declaration.
2136   serialization::DeclID ID;
2137   assert(!D->isFromASTFile() && "should not be emitting imported decl");
2138   serialization::DeclID &IDR = DeclIDs[D];
2139   if (IDR == 0)
2140     IDR = NextDeclID++;
2141 
2142   ID = IDR;
2143 
2144   assert(ID >= FirstDeclID && "invalid decl ID");
2145 
2146   RecordData Record;
2147   ASTDeclWriter W(*this, Context, Record);
2148 
2149   // Build a record for this declaration
2150   W.Visit(D);
2151 
2152   // Emit this declaration to the bitstream.
2153   uint64_t Offset = W.Emit(D);
2154 
2155   // Record the offset for this declaration
2156   SourceLocation Loc = D->getLocation();
2157   unsigned Index = ID - FirstDeclID;
2158   if (DeclOffsets.size() == Index)
2159     DeclOffsets.push_back(DeclOffset(Loc, Offset));
2160   else if (DeclOffsets.size() < Index) {
2161     // FIXME: Can/should this happen?
2162     DeclOffsets.resize(Index+1);
2163     DeclOffsets[Index].setLocation(Loc);
2164     DeclOffsets[Index].BitOffset = Offset;
2165   } else {
2166     llvm_unreachable("declarations should be emitted in ID order");
2167   }
2168 
2169   SourceManager &SM = Context.getSourceManager();
2170   if (Loc.isValid() && SM.isLocalSourceLocation(Loc))
2171     associateDeclWithFile(D, ID);
2172 
2173   // Note declarations that should be deserialized eagerly so that we can add
2174   // them to a record in the AST file later.
2175   if (isRequiredDecl(D, Context, WritingModule))
2176     EagerlyDeserializedDecls.push_back(ID);
2177 }
2178 
2179 void ASTRecordWriter::AddFunctionDefinition(const FunctionDecl *FD) {
2180   // Switch case IDs are per function body.
2181   Writer->ClearSwitchCaseIDs();
2182 
2183   assert(FD->doesThisDeclarationHaveABody());
2184   if (auto *CD = dyn_cast<CXXConstructorDecl>(FD)) {
2185     Record->push_back(CD->getNumCtorInitializers());
2186     if (CD->getNumCtorInitializers())
2187       AddCXXCtorInitializers(
2188           llvm::makeArrayRef(CD->init_begin(), CD->init_end()));
2189   }
2190   AddStmt(FD->getBody());
2191 }
2192