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/AST/PrettyDeclStackTrace.h"
21 #include "clang/Basic/SourceManager.h"
22 #include "clang/Serialization/ASTReader.h"
23 #include "clang/Serialization/ASTWriter.h"
24 #include "llvm/Bitcode/BitstreamWriter.h"
25 #include "llvm/Support/ErrorHandling.h"
26 using namespace clang;
27 using namespace serialization;
28 
29 //===----------------------------------------------------------------------===//
30 // Declaration serialization
31 //===----------------------------------------------------------------------===//
32 
33 namespace clang {
34   class ASTDeclWriter : public DeclVisitor<ASTDeclWriter, void> {
35     ASTWriter &Writer;
36     ASTContext &Context;
37     ASTRecordWriter Record;
38 
39     serialization::DeclCode Code;
40     unsigned AbbrevToUse;
41 
42   public:
43     ASTDeclWriter(ASTWriter &Writer, ASTContext &Context,
44                   ASTWriter::RecordDataImpl &Record)
45         : Writer(Writer), Context(Context), Record(Writer, Record),
46           Code((serialization::DeclCode)0), AbbrevToUse(0) {}
47 
48     uint64_t Emit(Decl *D) {
49       if (!Code)
50         llvm::report_fatal_error(StringRef("unexpected declaration kind '") +
51             D->getDeclKindName() + "'");
52       return Record.Emit(Code, AbbrevToUse);
53     }
54 
55     void Visit(Decl *D);
56 
57     void VisitDecl(Decl *D);
58     void VisitPragmaCommentDecl(PragmaCommentDecl *D);
59     void VisitPragmaDetectMismatchDecl(PragmaDetectMismatchDecl *D);
60     void VisitTranslationUnitDecl(TranslationUnitDecl *D);
61     void VisitNamedDecl(NamedDecl *D);
62     void VisitLabelDecl(LabelDecl *LD);
63     void VisitNamespaceDecl(NamespaceDecl *D);
64     void VisitUsingDirectiveDecl(UsingDirectiveDecl *D);
65     void VisitNamespaceAliasDecl(NamespaceAliasDecl *D);
66     void VisitTypeDecl(TypeDecl *D);
67     void VisitTypedefNameDecl(TypedefNameDecl *D);
68     void VisitTypedefDecl(TypedefDecl *D);
69     void VisitTypeAliasDecl(TypeAliasDecl *D);
70     void VisitUnresolvedUsingTypenameDecl(UnresolvedUsingTypenameDecl *D);
71     void VisitTagDecl(TagDecl *D);
72     void VisitEnumDecl(EnumDecl *D);
73     void VisitRecordDecl(RecordDecl *D);
74     void VisitCXXRecordDecl(CXXRecordDecl *D);
75     void VisitClassTemplateSpecializationDecl(
76                                             ClassTemplateSpecializationDecl *D);
77     void VisitClassTemplatePartialSpecializationDecl(
78                                      ClassTemplatePartialSpecializationDecl *D);
79     void VisitVarTemplateSpecializationDecl(VarTemplateSpecializationDecl *D);
80     void VisitVarTemplatePartialSpecializationDecl(
81         VarTemplatePartialSpecializationDecl *D);
82     void VisitClassScopeFunctionSpecializationDecl(
83                                        ClassScopeFunctionSpecializationDecl *D);
84     void VisitTemplateTypeParmDecl(TemplateTypeParmDecl *D);
85     void VisitValueDecl(ValueDecl *D);
86     void VisitEnumConstantDecl(EnumConstantDecl *D);
87     void VisitUnresolvedUsingValueDecl(UnresolvedUsingValueDecl *D);
88     void VisitDeclaratorDecl(DeclaratorDecl *D);
89     void VisitFunctionDecl(FunctionDecl *D);
90     void VisitCXXDeductionGuideDecl(CXXDeductionGuideDecl *D);
91     void VisitCXXMethodDecl(CXXMethodDecl *D);
92     void VisitCXXConstructorDecl(CXXConstructorDecl *D);
93     void VisitCXXDestructorDecl(CXXDestructorDecl *D);
94     void VisitCXXConversionDecl(CXXConversionDecl *D);
95     void VisitFieldDecl(FieldDecl *D);
96     void VisitMSPropertyDecl(MSPropertyDecl *D);
97     void VisitIndirectFieldDecl(IndirectFieldDecl *D);
98     void VisitVarDecl(VarDecl *D);
99     void VisitImplicitParamDecl(ImplicitParamDecl *D);
100     void VisitParmVarDecl(ParmVarDecl *D);
101     void VisitDecompositionDecl(DecompositionDecl *D);
102     void VisitBindingDecl(BindingDecl *D);
103     void VisitNonTypeTemplateParmDecl(NonTypeTemplateParmDecl *D);
104     void VisitTemplateDecl(TemplateDecl *D);
105     void VisitRedeclarableTemplateDecl(RedeclarableTemplateDecl *D);
106     void VisitClassTemplateDecl(ClassTemplateDecl *D);
107     void VisitVarTemplateDecl(VarTemplateDecl *D);
108     void VisitFunctionTemplateDecl(FunctionTemplateDecl *D);
109     void VisitTemplateTemplateParmDecl(TemplateTemplateParmDecl *D);
110     void VisitTypeAliasTemplateDecl(TypeAliasTemplateDecl *D);
111     void VisitUsingDecl(UsingDecl *D);
112     void VisitUsingPackDecl(UsingPackDecl *D);
113     void VisitUsingShadowDecl(UsingShadowDecl *D);
114     void VisitConstructorUsingShadowDecl(ConstructorUsingShadowDecl *D);
115     void VisitLinkageSpecDecl(LinkageSpecDecl *D);
116     void VisitExportDecl(ExportDecl *D);
117     void VisitFileScopeAsmDecl(FileScopeAsmDecl *D);
118     void VisitImportDecl(ImportDecl *D);
119     void VisitAccessSpecDecl(AccessSpecDecl *D);
120     void VisitFriendDecl(FriendDecl *D);
121     void VisitFriendTemplateDecl(FriendTemplateDecl *D);
122     void VisitStaticAssertDecl(StaticAssertDecl *D);
123     void VisitBlockDecl(BlockDecl *D);
124     void VisitCapturedDecl(CapturedDecl *D);
125     void VisitEmptyDecl(EmptyDecl *D);
126 
127     void VisitDeclContext(DeclContext *DC);
128     template <typename T> void VisitRedeclarable(Redeclarable<T> *D);
129 
130 
131     // FIXME: Put in the same order is DeclNodes.td?
132     void VisitObjCMethodDecl(ObjCMethodDecl *D);
133     void VisitObjCTypeParamDecl(ObjCTypeParamDecl *D);
134     void VisitObjCContainerDecl(ObjCContainerDecl *D);
135     void VisitObjCInterfaceDecl(ObjCInterfaceDecl *D);
136     void VisitObjCIvarDecl(ObjCIvarDecl *D);
137     void VisitObjCProtocolDecl(ObjCProtocolDecl *D);
138     void VisitObjCAtDefsFieldDecl(ObjCAtDefsFieldDecl *D);
139     void VisitObjCCategoryDecl(ObjCCategoryDecl *D);
140     void VisitObjCImplDecl(ObjCImplDecl *D);
141     void VisitObjCCategoryImplDecl(ObjCCategoryImplDecl *D);
142     void VisitObjCImplementationDecl(ObjCImplementationDecl *D);
143     void VisitObjCCompatibleAliasDecl(ObjCCompatibleAliasDecl *D);
144     void VisitObjCPropertyDecl(ObjCPropertyDecl *D);
145     void VisitObjCPropertyImplDecl(ObjCPropertyImplDecl *D);
146     void VisitOMPThreadPrivateDecl(OMPThreadPrivateDecl *D);
147     void VisitOMPDeclareReductionDecl(OMPDeclareReductionDecl *D);
148     void VisitOMPCapturedExprDecl(OMPCapturedExprDecl *D);
149 
150     /// Add an Objective-C type parameter list to the given record.
151     void AddObjCTypeParamList(ObjCTypeParamList *typeParams) {
152       // Empty type parameter list.
153       if (!typeParams) {
154         Record.push_back(0);
155         return;
156       }
157 
158       Record.push_back(typeParams->size());
159       for (auto typeParam : *typeParams) {
160         Record.AddDeclRef(typeParam);
161       }
162       Record.AddSourceLocation(typeParams->getLAngleLoc());
163       Record.AddSourceLocation(typeParams->getRAngleLoc());
164     }
165 
166     /// Add to the record the first declaration from each module file that
167     /// provides a declaration of D. The intent is to provide a sufficient
168     /// set such that reloading this set will load all current redeclarations.
169     void AddFirstDeclFromEachModule(const Decl *D, bool IncludeLocal) {
170       llvm::MapVector<ModuleFile*, const Decl*> Firsts;
171       // FIXME: We can skip entries that we know are implied by others.
172       for (const Decl *R = D->getMostRecentDecl(); R; R = R->getPreviousDecl()) {
173         if (R->isFromASTFile())
174           Firsts[Writer.Chain->getOwningModuleFile(R)] = R;
175         else if (IncludeLocal)
176           Firsts[nullptr] = R;
177       }
178       for (const auto &F : Firsts)
179         Record.AddDeclRef(F.second);
180     }
181 
182     /// Get the specialization decl from an entry in the specialization list.
183     template <typename EntryType>
184     typename RedeclarableTemplateDecl::SpecEntryTraits<EntryType>::DeclType *
185     getSpecializationDecl(EntryType &T) {
186       return RedeclarableTemplateDecl::SpecEntryTraits<EntryType>::getDecl(&T);
187     }
188 
189     /// Get the list of partial specializations from a template's common ptr.
190     template<typename T>
191     decltype(T::PartialSpecializations) &getPartialSpecializations(T *Common) {
192       return Common->PartialSpecializations;
193     }
194     ArrayRef<Decl> getPartialSpecializations(FunctionTemplateDecl::Common *) {
195       return None;
196     }
197 
198     template<typename DeclTy>
199     void AddTemplateSpecializations(DeclTy *D) {
200       auto *Common = D->getCommonPtr();
201 
202       // If we have any lazy specializations, and the external AST source is
203       // our chained AST reader, we can just write out the DeclIDs. Otherwise,
204       // we need to resolve them to actual declarations.
205       if (Writer.Chain != Writer.Context->getExternalSource() &&
206           Common->LazySpecializations) {
207         D->LoadLazySpecializations();
208         assert(!Common->LazySpecializations);
209       }
210 
211       ArrayRef<DeclID> LazySpecializations;
212       if (auto *LS = Common->LazySpecializations)
213         LazySpecializations = llvm::makeArrayRef(LS + 1, LS[0]);
214 
215       // Add a slot to the record for the number of specializations.
216       unsigned I = Record.size();
217       Record.push_back(0);
218 
219       // AddFirstDeclFromEachModule might trigger deserialization, invalidating
220       // *Specializations iterators.
221       llvm::SmallVector<const Decl*, 16> Specs;
222       for (auto &Entry : Common->Specializations)
223         Specs.push_back(getSpecializationDecl(Entry));
224       for (auto &Entry : getPartialSpecializations(Common))
225         Specs.push_back(getSpecializationDecl(Entry));
226 
227       for (auto *D : Specs) {
228         assert(D->isCanonicalDecl() && "non-canonical decl in set");
229         AddFirstDeclFromEachModule(D, /*IncludeLocal*/true);
230       }
231       Record.append(LazySpecializations.begin(), LazySpecializations.end());
232 
233       // Update the size entry we added earlier.
234       Record[I] = Record.size() - I - 1;
235     }
236 
237     /// Ensure that this template specialization is associated with the specified
238     /// template on reload.
239     void RegisterTemplateSpecialization(const Decl *Template,
240                                         const Decl *Specialization) {
241       Template = Template->getCanonicalDecl();
242 
243       // If the canonical template is local, we'll write out this specialization
244       // when we emit it.
245       // FIXME: We can do the same thing if there is any local declaration of
246       // the template, to avoid emitting an update record.
247       if (!Template->isFromASTFile())
248         return;
249 
250       // We only need to associate the first local declaration of the
251       // specialization. The other declarations will get pulled in by it.
252       if (Writer.getFirstLocalDecl(Specialization) != Specialization)
253         return;
254 
255       Writer.DeclUpdates[Template].push_back(ASTWriter::DeclUpdate(
256           UPD_CXX_ADDED_TEMPLATE_SPECIALIZATION, Specialization));
257     }
258   };
259 }
260 
261 void ASTDeclWriter::Visit(Decl *D) {
262   DeclVisitor<ASTDeclWriter>::Visit(D);
263 
264   // Source locations require array (variable-length) abbreviations.  The
265   // abbreviation infrastructure requires that arrays are encoded last, so
266   // we handle it here in the case of those classes derived from DeclaratorDecl
267   if (DeclaratorDecl *DD = dyn_cast<DeclaratorDecl>(D)) {
268     Record.AddTypeSourceInfo(DD->getTypeSourceInfo());
269   }
270 
271   // Handle FunctionDecl's body here and write it after all other Stmts/Exprs
272   // have been written. We want it last because we will not read it back when
273   // retrieving it from the AST, we'll just lazily set the offset.
274   if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
275     Record.push_back(FD->doesThisDeclarationHaveABody());
276     if (FD->doesThisDeclarationHaveABody())
277       Record.AddFunctionDefinition(FD);
278   }
279 
280   // If this declaration is also a DeclContext, write blocks for the
281   // declarations that lexically stored inside its context and those
282   // declarations that are visible from its context.
283   if (DeclContext *DC = dyn_cast<DeclContext>(D))
284     VisitDeclContext(DC);
285 }
286 
287 void ASTDeclWriter::VisitDecl(Decl *D) {
288   Record.AddDeclRef(cast_or_null<Decl>(D->getDeclContext()));
289   if (D->getDeclContext() != D->getLexicalDeclContext())
290     Record.AddDeclRef(cast_or_null<Decl>(D->getLexicalDeclContext()));
291   else
292     Record.push_back(0);
293   Record.push_back(D->isInvalidDecl());
294   Record.push_back(D->hasAttrs());
295   if (D->hasAttrs())
296     Record.AddAttributes(D->getAttrs());
297   Record.push_back(D->isImplicit());
298   Record.push_back(D->isUsed(false));
299   Record.push_back(D->isReferenced());
300   Record.push_back(D->isTopLevelDeclInObjCContainer());
301   Record.push_back(D->getAccess());
302   Record.push_back(D->isModulePrivate());
303   Record.push_back(Writer.getSubmoduleID(D->getOwningModule()));
304 
305   // If this declaration injected a name into a context different from its
306   // lexical context, and that context is an imported namespace, we need to
307   // update its visible declarations to include this name.
308   //
309   // This happens when we instantiate a class with a friend declaration or a
310   // function with a local extern declaration, for instance.
311   //
312   // FIXME: Can we handle this in AddedVisibleDecl instead?
313   if (D->isOutOfLine()) {
314     auto *DC = D->getDeclContext();
315     while (auto *NS = dyn_cast<NamespaceDecl>(DC->getRedeclContext())) {
316       if (!NS->isFromASTFile())
317         break;
318       Writer.UpdatedDeclContexts.insert(NS->getPrimaryContext());
319       if (!NS->isInlineNamespace())
320         break;
321       DC = NS->getParent();
322     }
323   }
324 }
325 
326 void ASTDeclWriter::VisitPragmaCommentDecl(PragmaCommentDecl *D) {
327   StringRef Arg = D->getArg();
328   Record.push_back(Arg.size());
329   VisitDecl(D);
330   Record.AddSourceLocation(D->getLocStart());
331   Record.push_back(D->getCommentKind());
332   Record.AddString(Arg);
333   Code = serialization::DECL_PRAGMA_COMMENT;
334 }
335 
336 void ASTDeclWriter::VisitPragmaDetectMismatchDecl(
337     PragmaDetectMismatchDecl *D) {
338   StringRef Name = D->getName();
339   StringRef Value = D->getValue();
340   Record.push_back(Name.size() + 1 + Value.size());
341   VisitDecl(D);
342   Record.AddSourceLocation(D->getLocStart());
343   Record.AddString(Name);
344   Record.AddString(Value);
345   Code = serialization::DECL_PRAGMA_DETECT_MISMATCH;
346 }
347 
348 void ASTDeclWriter::VisitTranslationUnitDecl(TranslationUnitDecl *D) {
349   llvm_unreachable("Translation units aren't directly serialized");
350 }
351 
352 void ASTDeclWriter::VisitNamedDecl(NamedDecl *D) {
353   VisitDecl(D);
354   Record.AddDeclarationName(D->getDeclName());
355   Record.push_back(needsAnonymousDeclarationNumber(D)
356                        ? Writer.getAnonymousDeclarationNumber(D)
357                        : 0);
358 }
359 
360 void ASTDeclWriter::VisitTypeDecl(TypeDecl *D) {
361   VisitNamedDecl(D);
362   Record.AddSourceLocation(D->getLocStart());
363   Record.AddTypeRef(QualType(D->getTypeForDecl(), 0));
364 }
365 
366 void ASTDeclWriter::VisitTypedefNameDecl(TypedefNameDecl *D) {
367   VisitRedeclarable(D);
368   VisitTypeDecl(D);
369   Record.AddTypeSourceInfo(D->getTypeSourceInfo());
370   Record.push_back(D->isModed());
371   if (D->isModed())
372     Record.AddTypeRef(D->getUnderlyingType());
373   Record.AddDeclRef(D->getAnonDeclWithTypedefName(false));
374 }
375 
376 void ASTDeclWriter::VisitTypedefDecl(TypedefDecl *D) {
377   VisitTypedefNameDecl(D);
378   if (D->getDeclContext() == D->getLexicalDeclContext() &&
379       !D->hasAttrs() &&
380       !D->isImplicit() &&
381       D->getFirstDecl() == D->getMostRecentDecl() &&
382       !D->isInvalidDecl() &&
383       !D->isTopLevelDeclInObjCContainer() &&
384       !D->isModulePrivate() &&
385       !needsAnonymousDeclarationNumber(D) &&
386       D->getDeclName().getNameKind() == DeclarationName::Identifier)
387     AbbrevToUse = Writer.getDeclTypedefAbbrev();
388 
389   Code = serialization::DECL_TYPEDEF;
390 }
391 
392 void ASTDeclWriter::VisitTypeAliasDecl(TypeAliasDecl *D) {
393   VisitTypedefNameDecl(D);
394   Record.AddDeclRef(D->getDescribedAliasTemplate());
395   Code = serialization::DECL_TYPEALIAS;
396 }
397 
398 void ASTDeclWriter::VisitTagDecl(TagDecl *D) {
399   VisitRedeclarable(D);
400   VisitTypeDecl(D);
401   Record.push_back(D->getIdentifierNamespace());
402   Record.push_back((unsigned)D->getTagKind()); // FIXME: stable encoding
403   if (!isa<CXXRecordDecl>(D))
404     Record.push_back(D->isCompleteDefinition());
405   Record.push_back(D->isEmbeddedInDeclarator());
406   Record.push_back(D->isFreeStanding());
407   Record.push_back(D->isCompleteDefinitionRequired());
408   Record.AddSourceRange(D->getBraceRange());
409 
410   if (D->hasExtInfo()) {
411     Record.push_back(1);
412     Record.AddQualifierInfo(*D->getExtInfo());
413   } else if (auto *TD = D->getTypedefNameForAnonDecl()) {
414     Record.push_back(2);
415     Record.AddDeclRef(TD);
416     Record.AddIdentifierRef(TD->getDeclName().getAsIdentifierInfo());
417   } else {
418     Record.push_back(0);
419   }
420 }
421 
422 void ASTDeclWriter::VisitEnumDecl(EnumDecl *D) {
423   VisitTagDecl(D);
424   Record.AddTypeSourceInfo(D->getIntegerTypeSourceInfo());
425   if (!D->getIntegerTypeSourceInfo())
426     Record.AddTypeRef(D->getIntegerType());
427   Record.AddTypeRef(D->getPromotionType());
428   Record.push_back(D->getNumPositiveBits());
429   Record.push_back(D->getNumNegativeBits());
430   Record.push_back(D->isScoped());
431   Record.push_back(D->isScopedUsingClassTag());
432   Record.push_back(D->isFixed());
433   if (MemberSpecializationInfo *MemberInfo = D->getMemberSpecializationInfo()) {
434     Record.AddDeclRef(MemberInfo->getInstantiatedFrom());
435     Record.push_back(MemberInfo->getTemplateSpecializationKind());
436     Record.AddSourceLocation(MemberInfo->getPointOfInstantiation());
437   } else {
438     Record.AddDeclRef(nullptr);
439   }
440 
441   if (D->getDeclContext() == D->getLexicalDeclContext() &&
442       !D->hasAttrs() &&
443       !D->isImplicit() &&
444       !D->isUsed(false) &&
445       !D->hasExtInfo() &&
446       !D->getTypedefNameForAnonDecl() &&
447       D->getFirstDecl() == D->getMostRecentDecl() &&
448       !D->isInvalidDecl() &&
449       !D->isReferenced() &&
450       !D->isTopLevelDeclInObjCContainer() &&
451       D->getAccess() == AS_none &&
452       !D->isModulePrivate() &&
453       !CXXRecordDecl::classofKind(D->getKind()) &&
454       !D->getIntegerTypeSourceInfo() &&
455       !D->getMemberSpecializationInfo() &&
456       !needsAnonymousDeclarationNumber(D) &&
457       D->getDeclName().getNameKind() == DeclarationName::Identifier)
458     AbbrevToUse = Writer.getDeclEnumAbbrev();
459 
460   Code = serialization::DECL_ENUM;
461 }
462 
463 void ASTDeclWriter::VisitRecordDecl(RecordDecl *D) {
464   VisitTagDecl(D);
465   Record.push_back(D->hasFlexibleArrayMember());
466   Record.push_back(D->isAnonymousStructOrUnion());
467   Record.push_back(D->hasObjectMember());
468   Record.push_back(D->hasVolatileMember());
469   Record.push_back(D->isNonTrivialToPrimitiveDefaultInitialize());
470   Record.push_back(D->isNonTrivialToPrimitiveCopy());
471   Record.push_back(D->isNonTrivialToPrimitiveDestroy());
472   Record.push_back(D->canPassInRegisters());
473 
474   if (D->getDeclContext() == D->getLexicalDeclContext() &&
475       !D->hasAttrs() &&
476       !D->isImplicit() &&
477       !D->isUsed(false) &&
478       !D->hasExtInfo() &&
479       !D->getTypedefNameForAnonDecl() &&
480       D->getFirstDecl() == D->getMostRecentDecl() &&
481       !D->isInvalidDecl() &&
482       !D->isReferenced() &&
483       !D->isTopLevelDeclInObjCContainer() &&
484       D->getAccess() == AS_none &&
485       !D->isModulePrivate() &&
486       !CXXRecordDecl::classofKind(D->getKind()) &&
487       !needsAnonymousDeclarationNumber(D) &&
488       D->getDeclName().getNameKind() == DeclarationName::Identifier)
489     AbbrevToUse = Writer.getDeclRecordAbbrev();
490 
491   Code = serialization::DECL_RECORD;
492 }
493 
494 void ASTDeclWriter::VisitValueDecl(ValueDecl *D) {
495   VisitNamedDecl(D);
496   Record.AddTypeRef(D->getType());
497 }
498 
499 void ASTDeclWriter::VisitEnumConstantDecl(EnumConstantDecl *D) {
500   VisitValueDecl(D);
501   Record.push_back(D->getInitExpr()? 1 : 0);
502   if (D->getInitExpr())
503     Record.AddStmt(D->getInitExpr());
504   Record.AddAPSInt(D->getInitVal());
505 
506   Code = serialization::DECL_ENUM_CONSTANT;
507 }
508 
509 void ASTDeclWriter::VisitDeclaratorDecl(DeclaratorDecl *D) {
510   VisitValueDecl(D);
511   Record.AddSourceLocation(D->getInnerLocStart());
512   Record.push_back(D->hasExtInfo());
513   if (D->hasExtInfo())
514     Record.AddQualifierInfo(*D->getExtInfo());
515 }
516 
517 void ASTDeclWriter::VisitFunctionDecl(FunctionDecl *D) {
518   VisitRedeclarable(D);
519   VisitDeclaratorDecl(D);
520   Record.AddDeclarationNameLoc(D->DNLoc, D->getDeclName());
521   Record.push_back(D->getIdentifierNamespace());
522 
523   // FunctionDecl's body is handled last at ASTWriterDecl::Visit,
524   // after everything else is written.
525 
526   Record.push_back((int)D->SClass); // FIXME: stable encoding
527   Record.push_back(D->IsInline);
528   Record.push_back(D->IsInlineSpecified);
529   Record.push_back(D->IsExplicitSpecified);
530   Record.push_back(D->IsVirtualAsWritten);
531   Record.push_back(D->IsPure);
532   Record.push_back(D->HasInheritedPrototype);
533   Record.push_back(D->HasWrittenPrototype);
534   Record.push_back(D->IsDeleted);
535   Record.push_back(D->IsTrivial);
536   Record.push_back(D->IsTrivialForCall);
537   Record.push_back(D->IsDefaulted);
538   Record.push_back(D->IsExplicitlyDefaulted);
539   Record.push_back(D->HasImplicitReturnZero);
540   Record.push_back(D->IsConstexpr);
541   Record.push_back(D->UsesSEHTry);
542   Record.push_back(D->HasSkippedBody);
543   Record.push_back(D->IsMultiVersion);
544   Record.push_back(D->IsLateTemplateParsed);
545   Record.push_back(D->getLinkageInternal());
546   Record.AddSourceLocation(D->getLocEnd());
547 
548   Record.push_back(D->getODRHash());
549 
550   Record.push_back(D->getTemplatedKind());
551   switch (D->getTemplatedKind()) {
552   case FunctionDecl::TK_NonTemplate:
553     break;
554   case FunctionDecl::TK_FunctionTemplate:
555     Record.AddDeclRef(D->getDescribedFunctionTemplate());
556     break;
557   case FunctionDecl::TK_MemberSpecialization: {
558     MemberSpecializationInfo *MemberInfo = D->getMemberSpecializationInfo();
559     Record.AddDeclRef(MemberInfo->getInstantiatedFrom());
560     Record.push_back(MemberInfo->getTemplateSpecializationKind());
561     Record.AddSourceLocation(MemberInfo->getPointOfInstantiation());
562     break;
563   }
564   case FunctionDecl::TK_FunctionTemplateSpecialization: {
565     FunctionTemplateSpecializationInfo *
566       FTSInfo = D->getTemplateSpecializationInfo();
567 
568     RegisterTemplateSpecialization(FTSInfo->getTemplate(), D);
569 
570     Record.AddDeclRef(FTSInfo->getTemplate());
571     Record.push_back(FTSInfo->getTemplateSpecializationKind());
572 
573     // Template arguments.
574     Record.AddTemplateArgumentList(FTSInfo->TemplateArguments);
575 
576     // Template args as written.
577     Record.push_back(FTSInfo->TemplateArgumentsAsWritten != nullptr);
578     if (FTSInfo->TemplateArgumentsAsWritten) {
579       Record.push_back(FTSInfo->TemplateArgumentsAsWritten->NumTemplateArgs);
580       for (int i=0, e = FTSInfo->TemplateArgumentsAsWritten->NumTemplateArgs;
581              i!=e; ++i)
582         Record.AddTemplateArgumentLoc(
583             (*FTSInfo->TemplateArgumentsAsWritten)[i]);
584       Record.AddSourceLocation(FTSInfo->TemplateArgumentsAsWritten->LAngleLoc);
585       Record.AddSourceLocation(FTSInfo->TemplateArgumentsAsWritten->RAngleLoc);
586     }
587 
588     Record.AddSourceLocation(FTSInfo->getPointOfInstantiation());
589 
590     if (D->isCanonicalDecl()) {
591       // Write the template that contains the specializations set. We will
592       // add a FunctionTemplateSpecializationInfo to it when reading.
593       Record.AddDeclRef(FTSInfo->getTemplate()->getCanonicalDecl());
594     }
595     break;
596   }
597   case FunctionDecl::TK_DependentFunctionTemplateSpecialization: {
598     DependentFunctionTemplateSpecializationInfo *
599       DFTSInfo = D->getDependentSpecializationInfo();
600 
601     // Templates.
602     Record.push_back(DFTSInfo->getNumTemplates());
603     for (int i=0, e = DFTSInfo->getNumTemplates(); i != e; ++i)
604       Record.AddDeclRef(DFTSInfo->getTemplate(i));
605 
606     // Templates args.
607     Record.push_back(DFTSInfo->getNumTemplateArgs());
608     for (int i=0, e = DFTSInfo->getNumTemplateArgs(); i != e; ++i)
609       Record.AddTemplateArgumentLoc(DFTSInfo->getTemplateArg(i));
610     Record.AddSourceLocation(DFTSInfo->getLAngleLoc());
611     Record.AddSourceLocation(DFTSInfo->getRAngleLoc());
612     break;
613   }
614   }
615 
616   Record.push_back(D->param_size());
617   for (auto P : D->parameters())
618     Record.AddDeclRef(P);
619   Code = serialization::DECL_FUNCTION;
620 }
621 
622 void ASTDeclWriter::VisitCXXDeductionGuideDecl(CXXDeductionGuideDecl *D) {
623   VisitFunctionDecl(D);
624   Record.push_back(D->IsCopyDeductionCandidate);
625   Code = serialization::DECL_CXX_DEDUCTION_GUIDE;
626 }
627 
628 void ASTDeclWriter::VisitObjCMethodDecl(ObjCMethodDecl *D) {
629   VisitNamedDecl(D);
630   // FIXME: convert to LazyStmtPtr?
631   // Unlike C/C++, method bodies will never be in header files.
632   bool HasBodyStuff = D->getBody() != nullptr     ||
633                       D->getSelfDecl() != nullptr || D->getCmdDecl() != nullptr;
634   Record.push_back(HasBodyStuff);
635   if (HasBodyStuff) {
636     Record.AddStmt(D->getBody());
637     Record.AddDeclRef(D->getSelfDecl());
638     Record.AddDeclRef(D->getCmdDecl());
639   }
640   Record.push_back(D->isInstanceMethod());
641   Record.push_back(D->isVariadic());
642   Record.push_back(D->isPropertyAccessor());
643   Record.push_back(D->isDefined());
644   Record.push_back(D->IsOverriding);
645   Record.push_back(D->HasSkippedBody);
646 
647   Record.push_back(D->IsRedeclaration);
648   Record.push_back(D->HasRedeclaration);
649   if (D->HasRedeclaration) {
650     assert(Context.getObjCMethodRedeclaration(D));
651     Record.AddDeclRef(Context.getObjCMethodRedeclaration(D));
652   }
653 
654   // FIXME: stable encoding for @required/@optional
655   Record.push_back(D->getImplementationControl());
656   // FIXME: stable encoding for in/out/inout/bycopy/byref/oneway/nullability
657   Record.push_back(D->getObjCDeclQualifier());
658   Record.push_back(D->hasRelatedResultType());
659   Record.AddTypeRef(D->getReturnType());
660   Record.AddTypeSourceInfo(D->getReturnTypeSourceInfo());
661   Record.AddSourceLocation(D->getLocEnd());
662   Record.push_back(D->param_size());
663   for (const auto *P : D->parameters())
664     Record.AddDeclRef(P);
665 
666   Record.push_back(D->SelLocsKind);
667   unsigned NumStoredSelLocs = D->getNumStoredSelLocs();
668   SourceLocation *SelLocs = D->getStoredSelLocs();
669   Record.push_back(NumStoredSelLocs);
670   for (unsigned i = 0; i != NumStoredSelLocs; ++i)
671     Record.AddSourceLocation(SelLocs[i]);
672 
673   Code = serialization::DECL_OBJC_METHOD;
674 }
675 
676 void ASTDeclWriter::VisitObjCTypeParamDecl(ObjCTypeParamDecl *D) {
677   VisitTypedefNameDecl(D);
678   Record.push_back(D->Variance);
679   Record.push_back(D->Index);
680   Record.AddSourceLocation(D->VarianceLoc);
681   Record.AddSourceLocation(D->ColonLoc);
682 
683   Code = serialization::DECL_OBJC_TYPE_PARAM;
684 }
685 
686 void ASTDeclWriter::VisitObjCContainerDecl(ObjCContainerDecl *D) {
687   VisitNamedDecl(D);
688   Record.AddSourceLocation(D->getAtStartLoc());
689   Record.AddSourceRange(D->getAtEndRange());
690   // Abstract class (no need to define a stable serialization::DECL code).
691 }
692 
693 void ASTDeclWriter::VisitObjCInterfaceDecl(ObjCInterfaceDecl *D) {
694   VisitRedeclarable(D);
695   VisitObjCContainerDecl(D);
696   Record.AddTypeRef(QualType(D->getTypeForDecl(), 0));
697   AddObjCTypeParamList(D->TypeParamList);
698 
699   Record.push_back(D->isThisDeclarationADefinition());
700   if (D->isThisDeclarationADefinition()) {
701     // Write the DefinitionData
702     ObjCInterfaceDecl::DefinitionData &Data = D->data();
703 
704     Record.AddTypeSourceInfo(D->getSuperClassTInfo());
705     Record.AddSourceLocation(D->getEndOfDefinitionLoc());
706     Record.push_back(Data.HasDesignatedInitializers);
707 
708     // Write out the protocols that are directly referenced by the @interface.
709     Record.push_back(Data.ReferencedProtocols.size());
710     for (const auto *P : D->protocols())
711       Record.AddDeclRef(P);
712     for (const auto &PL : D->protocol_locs())
713       Record.AddSourceLocation(PL);
714 
715     // Write out the protocols that are transitively referenced.
716     Record.push_back(Data.AllReferencedProtocols.size());
717     for (ObjCList<ObjCProtocolDecl>::iterator
718               P = Data.AllReferencedProtocols.begin(),
719            PEnd = Data.AllReferencedProtocols.end();
720          P != PEnd; ++P)
721       Record.AddDeclRef(*P);
722 
723 
724     if (ObjCCategoryDecl *Cat = D->getCategoryListRaw()) {
725       // Ensure that we write out the set of categories for this class.
726       Writer.ObjCClassesWithCategories.insert(D);
727 
728       // Make sure that the categories get serialized.
729       for (; Cat; Cat = Cat->getNextClassCategoryRaw())
730         (void)Writer.GetDeclRef(Cat);
731     }
732   }
733 
734   Code = serialization::DECL_OBJC_INTERFACE;
735 }
736 
737 void ASTDeclWriter::VisitObjCIvarDecl(ObjCIvarDecl *D) {
738   VisitFieldDecl(D);
739   // FIXME: stable encoding for @public/@private/@protected/@package
740   Record.push_back(D->getAccessControl());
741   Record.push_back(D->getSynthesize());
742 
743   if (D->getDeclContext() == D->getLexicalDeclContext() &&
744       !D->hasAttrs() &&
745       !D->isImplicit() &&
746       !D->isUsed(false) &&
747       !D->isInvalidDecl() &&
748       !D->isReferenced() &&
749       !D->isModulePrivate() &&
750       !D->getBitWidth() &&
751       !D->hasExtInfo() &&
752       D->getDeclName())
753     AbbrevToUse = Writer.getDeclObjCIvarAbbrev();
754 
755   Code = serialization::DECL_OBJC_IVAR;
756 }
757 
758 void ASTDeclWriter::VisitObjCProtocolDecl(ObjCProtocolDecl *D) {
759   VisitRedeclarable(D);
760   VisitObjCContainerDecl(D);
761 
762   Record.push_back(D->isThisDeclarationADefinition());
763   if (D->isThisDeclarationADefinition()) {
764     Record.push_back(D->protocol_size());
765     for (const auto *I : D->protocols())
766       Record.AddDeclRef(I);
767     for (const auto &PL : D->protocol_locs())
768       Record.AddSourceLocation(PL);
769   }
770 
771   Code = serialization::DECL_OBJC_PROTOCOL;
772 }
773 
774 void ASTDeclWriter::VisitObjCAtDefsFieldDecl(ObjCAtDefsFieldDecl *D) {
775   VisitFieldDecl(D);
776   Code = serialization::DECL_OBJC_AT_DEFS_FIELD;
777 }
778 
779 void ASTDeclWriter::VisitObjCCategoryDecl(ObjCCategoryDecl *D) {
780   VisitObjCContainerDecl(D);
781   Record.AddSourceLocation(D->getCategoryNameLoc());
782   Record.AddSourceLocation(D->getIvarLBraceLoc());
783   Record.AddSourceLocation(D->getIvarRBraceLoc());
784   Record.AddDeclRef(D->getClassInterface());
785   AddObjCTypeParamList(D->TypeParamList);
786   Record.push_back(D->protocol_size());
787   for (const auto *I : D->protocols())
788     Record.AddDeclRef(I);
789   for (const auto &PL : D->protocol_locs())
790     Record.AddSourceLocation(PL);
791   Code = serialization::DECL_OBJC_CATEGORY;
792 }
793 
794 void ASTDeclWriter::VisitObjCCompatibleAliasDecl(ObjCCompatibleAliasDecl *D) {
795   VisitNamedDecl(D);
796   Record.AddDeclRef(D->getClassInterface());
797   Code = serialization::DECL_OBJC_COMPATIBLE_ALIAS;
798 }
799 
800 void ASTDeclWriter::VisitObjCPropertyDecl(ObjCPropertyDecl *D) {
801   VisitNamedDecl(D);
802   Record.AddSourceLocation(D->getAtLoc());
803   Record.AddSourceLocation(D->getLParenLoc());
804   Record.AddTypeRef(D->getType());
805   Record.AddTypeSourceInfo(D->getTypeSourceInfo());
806   // FIXME: stable encoding
807   Record.push_back((unsigned)D->getPropertyAttributes());
808   Record.push_back((unsigned)D->getPropertyAttributesAsWritten());
809   // FIXME: stable encoding
810   Record.push_back((unsigned)D->getPropertyImplementation());
811   Record.AddDeclarationName(D->getGetterName());
812   Record.AddSourceLocation(D->getGetterNameLoc());
813   Record.AddDeclarationName(D->getSetterName());
814   Record.AddSourceLocation(D->getSetterNameLoc());
815   Record.AddDeclRef(D->getGetterMethodDecl());
816   Record.AddDeclRef(D->getSetterMethodDecl());
817   Record.AddDeclRef(D->getPropertyIvarDecl());
818   Code = serialization::DECL_OBJC_PROPERTY;
819 }
820 
821 void ASTDeclWriter::VisitObjCImplDecl(ObjCImplDecl *D) {
822   VisitObjCContainerDecl(D);
823   Record.AddDeclRef(D->getClassInterface());
824   // Abstract class (no need to define a stable serialization::DECL code).
825 }
826 
827 void ASTDeclWriter::VisitObjCCategoryImplDecl(ObjCCategoryImplDecl *D) {
828   VisitObjCImplDecl(D);
829   Record.AddSourceLocation(D->getCategoryNameLoc());
830   Code = serialization::DECL_OBJC_CATEGORY_IMPL;
831 }
832 
833 void ASTDeclWriter::VisitObjCImplementationDecl(ObjCImplementationDecl *D) {
834   VisitObjCImplDecl(D);
835   Record.AddDeclRef(D->getSuperClass());
836   Record.AddSourceLocation(D->getSuperClassLoc());
837   Record.AddSourceLocation(D->getIvarLBraceLoc());
838   Record.AddSourceLocation(D->getIvarRBraceLoc());
839   Record.push_back(D->hasNonZeroConstructors());
840   Record.push_back(D->hasDestructors());
841   Record.push_back(D->NumIvarInitializers);
842   if (D->NumIvarInitializers)
843     Record.AddCXXCtorInitializers(
844         llvm::makeArrayRef(D->init_begin(), D->init_end()));
845   Code = serialization::DECL_OBJC_IMPLEMENTATION;
846 }
847 
848 void ASTDeclWriter::VisitObjCPropertyImplDecl(ObjCPropertyImplDecl *D) {
849   VisitDecl(D);
850   Record.AddSourceLocation(D->getLocStart());
851   Record.AddDeclRef(D->getPropertyDecl());
852   Record.AddDeclRef(D->getPropertyIvarDecl());
853   Record.AddSourceLocation(D->getPropertyIvarDeclLoc());
854   Record.AddStmt(D->getGetterCXXConstructor());
855   Record.AddStmt(D->getSetterCXXAssignment());
856   Code = serialization::DECL_OBJC_PROPERTY_IMPL;
857 }
858 
859 void ASTDeclWriter::VisitFieldDecl(FieldDecl *D) {
860   VisitDeclaratorDecl(D);
861   Record.push_back(D->isMutable());
862 
863   FieldDecl::InitStorageKind ISK = D->InitStorage.getInt();
864   Record.push_back(ISK);
865   if (ISK == FieldDecl::ISK_CapturedVLAType)
866     Record.AddTypeRef(QualType(D->getCapturedVLAType(), 0));
867   else if (ISK)
868     Record.AddStmt(D->getInClassInitializer());
869 
870   Record.AddStmt(D->getBitWidth());
871 
872   if (!D->getDeclName())
873     Record.AddDeclRef(Context.getInstantiatedFromUnnamedFieldDecl(D));
874 
875   if (D->getDeclContext() == D->getLexicalDeclContext() &&
876       !D->hasAttrs() &&
877       !D->isImplicit() &&
878       !D->isUsed(false) &&
879       !D->isInvalidDecl() &&
880       !D->isReferenced() &&
881       !D->isTopLevelDeclInObjCContainer() &&
882       !D->isModulePrivate() &&
883       !D->getBitWidth() &&
884       !D->hasInClassInitializer() &&
885       !D->hasCapturedVLAType() &&
886       !D->hasExtInfo() &&
887       !ObjCIvarDecl::classofKind(D->getKind()) &&
888       !ObjCAtDefsFieldDecl::classofKind(D->getKind()) &&
889       D->getDeclName())
890     AbbrevToUse = Writer.getDeclFieldAbbrev();
891 
892   Code = serialization::DECL_FIELD;
893 }
894 
895 void ASTDeclWriter::VisitMSPropertyDecl(MSPropertyDecl *D) {
896   VisitDeclaratorDecl(D);
897   Record.AddIdentifierRef(D->getGetterId());
898   Record.AddIdentifierRef(D->getSetterId());
899   Code = serialization::DECL_MS_PROPERTY;
900 }
901 
902 void ASTDeclWriter::VisitIndirectFieldDecl(IndirectFieldDecl *D) {
903   VisitValueDecl(D);
904   Record.push_back(D->getChainingSize());
905 
906   for (const auto *P : D->chain())
907     Record.AddDeclRef(P);
908   Code = serialization::DECL_INDIRECTFIELD;
909 }
910 
911 void ASTDeclWriter::VisitVarDecl(VarDecl *D) {
912   VisitRedeclarable(D);
913   VisitDeclaratorDecl(D);
914   Record.push_back(D->getStorageClass());
915   Record.push_back(D->getTSCSpec());
916   Record.push_back(D->getInitStyle());
917   if (!isa<ParmVarDecl>(D)) {
918     Record.push_back(D->isThisDeclarationADemotedDefinition());
919     Record.push_back(D->isExceptionVariable());
920     Record.push_back(D->isNRVOVariable());
921     Record.push_back(D->isCXXForRangeDecl());
922     Record.push_back(D->isARCPseudoStrong());
923     Record.push_back(D->isInline());
924     Record.push_back(D->isInlineSpecified());
925     Record.push_back(D->isConstexpr());
926     Record.push_back(D->isInitCapture());
927     Record.push_back(D->isPreviousDeclInSameBlockScope());
928     if (const auto *IPD = dyn_cast<ImplicitParamDecl>(D))
929       Record.push_back(static_cast<unsigned>(IPD->getParameterKind()));
930     else
931       Record.push_back(0);
932   }
933   Record.push_back(D->getLinkageInternal());
934 
935   if (D->getInit()) {
936     Record.push_back(!D->isInitKnownICE() ? 1 : (D->isInitICE() ? 3 : 2));
937     Record.AddStmt(D->getInit());
938   } else {
939     Record.push_back(0);
940   }
941 
942   if (D->getStorageDuration() == SD_Static) {
943     bool ModulesCodegen = false;
944     if (Writer.WritingModule &&
945         !D->getDescribedVarTemplate() && !D->getMemberSpecializationInfo() &&
946         !isa<VarTemplateSpecializationDecl>(D)) {
947       // When building a C++ Modules TS module interface unit, a strong
948       // definition in the module interface is provided by the compilation of
949       // that module interface unit, not by its users. (Inline variables are
950       // still emitted in module users.)
951       ModulesCodegen =
952           (Writer.WritingModule->Kind == Module::ModuleInterfaceUnit &&
953            Writer.Context->GetGVALinkageForVariable(D) == GVA_StrongExternal);
954     }
955     Record.push_back(ModulesCodegen);
956     if (ModulesCodegen)
957       Writer.ModularCodegenDecls.push_back(Writer.GetDeclRef(D));
958   }
959 
960   enum {
961     VarNotTemplate = 0, VarTemplate, StaticDataMemberSpecialization
962   };
963   if (VarTemplateDecl *TemplD = D->getDescribedVarTemplate()) {
964     Record.push_back(VarTemplate);
965     Record.AddDeclRef(TemplD);
966   } else if (MemberSpecializationInfo *SpecInfo
967                = D->getMemberSpecializationInfo()) {
968     Record.push_back(StaticDataMemberSpecialization);
969     Record.AddDeclRef(SpecInfo->getInstantiatedFrom());
970     Record.push_back(SpecInfo->getTemplateSpecializationKind());
971     Record.AddSourceLocation(SpecInfo->getPointOfInstantiation());
972   } else {
973     Record.push_back(VarNotTemplate);
974   }
975 
976   if (D->getDeclContext() == D->getLexicalDeclContext() &&
977       !D->hasAttrs() &&
978       !D->isImplicit() &&
979       !D->isUsed(false) &&
980       !D->isInvalidDecl() &&
981       !D->isReferenced() &&
982       !D->isTopLevelDeclInObjCContainer() &&
983       D->getAccess() == AS_none &&
984       !D->isModulePrivate() &&
985       !needsAnonymousDeclarationNumber(D) &&
986       D->getDeclName().getNameKind() == DeclarationName::Identifier &&
987       !D->hasExtInfo() &&
988       D->getFirstDecl() == D->getMostRecentDecl() &&
989       D->getKind() == Decl::Var &&
990       !D->isInline() &&
991       !D->isConstexpr() &&
992       !D->isInitCapture() &&
993       !D->isPreviousDeclInSameBlockScope() &&
994       D->getStorageDuration() != SD_Static &&
995       !D->getMemberSpecializationInfo())
996     AbbrevToUse = Writer.getDeclVarAbbrev();
997 
998   Code = serialization::DECL_VAR;
999 }
1000 
1001 void ASTDeclWriter::VisitImplicitParamDecl(ImplicitParamDecl *D) {
1002   VisitVarDecl(D);
1003   Code = serialization::DECL_IMPLICIT_PARAM;
1004 }
1005 
1006 void ASTDeclWriter::VisitParmVarDecl(ParmVarDecl *D) {
1007   VisitVarDecl(D);
1008   Record.push_back(D->isObjCMethodParameter());
1009   Record.push_back(D->getFunctionScopeDepth());
1010   Record.push_back(D->getFunctionScopeIndex());
1011   Record.push_back(D->getObjCDeclQualifier()); // FIXME: stable encoding
1012   Record.push_back(D->isKNRPromoted());
1013   Record.push_back(D->hasInheritedDefaultArg());
1014   Record.push_back(D->hasUninstantiatedDefaultArg());
1015   if (D->hasUninstantiatedDefaultArg())
1016     Record.AddStmt(D->getUninstantiatedDefaultArg());
1017   Code = serialization::DECL_PARM_VAR;
1018 
1019   assert(!D->isARCPseudoStrong()); // can be true of ImplicitParamDecl
1020 
1021   // If the assumptions about the DECL_PARM_VAR abbrev are true, use it.  Here
1022   // we dynamically check for the properties that we optimize for, but don't
1023   // know are true of all PARM_VAR_DECLs.
1024   if (D->getDeclContext() == D->getLexicalDeclContext() &&
1025       !D->hasAttrs() &&
1026       !D->hasExtInfo() &&
1027       !D->isImplicit() &&
1028       !D->isUsed(false) &&
1029       !D->isInvalidDecl() &&
1030       !D->isReferenced() &&
1031       D->getAccess() == AS_none &&
1032       !D->isModulePrivate() &&
1033       D->getStorageClass() == 0 &&
1034       D->getInitStyle() == VarDecl::CInit && // Can params have anything else?
1035       D->getFunctionScopeDepth() == 0 &&
1036       D->getObjCDeclQualifier() == 0 &&
1037       !D->isKNRPromoted() &&
1038       !D->hasInheritedDefaultArg() &&
1039       D->getInit() == nullptr &&
1040       !D->hasUninstantiatedDefaultArg())  // No default expr.
1041     AbbrevToUse = Writer.getDeclParmVarAbbrev();
1042 
1043   // Check things we know are true of *every* PARM_VAR_DECL, which is more than
1044   // just us assuming it.
1045   assert(!D->getTSCSpec() && "PARM_VAR_DECL can't use TLS");
1046   assert(!D->isThisDeclarationADemotedDefinition()
1047          && "PARM_VAR_DECL can't be demoted definition.");
1048   assert(D->getAccess() == AS_none && "PARM_VAR_DECL can't be public/private");
1049   assert(!D->isExceptionVariable() && "PARM_VAR_DECL can't be exception var");
1050   assert(D->getPreviousDecl() == nullptr && "PARM_VAR_DECL can't be redecl");
1051   assert(!D->isStaticDataMember() &&
1052          "PARM_VAR_DECL can't be static data member");
1053 }
1054 
1055 void ASTDeclWriter::VisitDecompositionDecl(DecompositionDecl *D) {
1056   // Record the number of bindings first to simplify deserialization.
1057   Record.push_back(D->bindings().size());
1058 
1059   VisitVarDecl(D);
1060   for (auto *B : D->bindings())
1061     Record.AddDeclRef(B);
1062   Code = serialization::DECL_DECOMPOSITION;
1063 }
1064 
1065 void ASTDeclWriter::VisitBindingDecl(BindingDecl *D) {
1066   VisitValueDecl(D);
1067   Record.AddStmt(D->getBinding());
1068   Code = serialization::DECL_BINDING;
1069 }
1070 
1071 void ASTDeclWriter::VisitFileScopeAsmDecl(FileScopeAsmDecl *D) {
1072   VisitDecl(D);
1073   Record.AddStmt(D->getAsmString());
1074   Record.AddSourceLocation(D->getRParenLoc());
1075   Code = serialization::DECL_FILE_SCOPE_ASM;
1076 }
1077 
1078 void ASTDeclWriter::VisitEmptyDecl(EmptyDecl *D) {
1079   VisitDecl(D);
1080   Code = serialization::DECL_EMPTY;
1081 }
1082 
1083 void ASTDeclWriter::VisitBlockDecl(BlockDecl *D) {
1084   VisitDecl(D);
1085   Record.AddStmt(D->getBody());
1086   Record.AddTypeSourceInfo(D->getSignatureAsWritten());
1087   Record.push_back(D->param_size());
1088   for (ParmVarDecl *P : D->parameters())
1089     Record.AddDeclRef(P);
1090   Record.push_back(D->isVariadic());
1091   Record.push_back(D->blockMissingReturnType());
1092   Record.push_back(D->isConversionFromLambda());
1093   Record.push_back(D->capturesCXXThis());
1094   Record.push_back(D->getNumCaptures());
1095   for (const auto &capture : D->captures()) {
1096     Record.AddDeclRef(capture.getVariable());
1097 
1098     unsigned flags = 0;
1099     if (capture.isByRef()) flags |= 1;
1100     if (capture.isNested()) flags |= 2;
1101     if (capture.hasCopyExpr()) flags |= 4;
1102     Record.push_back(flags);
1103 
1104     if (capture.hasCopyExpr()) Record.AddStmt(capture.getCopyExpr());
1105   }
1106 
1107   Code = serialization::DECL_BLOCK;
1108 }
1109 
1110 void ASTDeclWriter::VisitCapturedDecl(CapturedDecl *CD) {
1111   Record.push_back(CD->getNumParams());
1112   VisitDecl(CD);
1113   Record.push_back(CD->getContextParamPosition());
1114   Record.push_back(CD->isNothrow() ? 1 : 0);
1115   // Body is stored by VisitCapturedStmt.
1116   for (unsigned I = 0; I < CD->getNumParams(); ++I)
1117     Record.AddDeclRef(CD->getParam(I));
1118   Code = serialization::DECL_CAPTURED;
1119 }
1120 
1121 void ASTDeclWriter::VisitLinkageSpecDecl(LinkageSpecDecl *D) {
1122   VisitDecl(D);
1123   Record.push_back(D->getLanguage());
1124   Record.AddSourceLocation(D->getExternLoc());
1125   Record.AddSourceLocation(D->getRBraceLoc());
1126   Code = serialization::DECL_LINKAGE_SPEC;
1127 }
1128 
1129 void ASTDeclWriter::VisitExportDecl(ExportDecl *D) {
1130   VisitDecl(D);
1131   Record.AddSourceLocation(D->getRBraceLoc());
1132   Code = serialization::DECL_EXPORT;
1133 }
1134 
1135 void ASTDeclWriter::VisitLabelDecl(LabelDecl *D) {
1136   VisitNamedDecl(D);
1137   Record.AddSourceLocation(D->getLocStart());
1138   Code = serialization::DECL_LABEL;
1139 }
1140 
1141 
1142 void ASTDeclWriter::VisitNamespaceDecl(NamespaceDecl *D) {
1143   VisitRedeclarable(D);
1144   VisitNamedDecl(D);
1145   Record.push_back(D->isInline());
1146   Record.AddSourceLocation(D->getLocStart());
1147   Record.AddSourceLocation(D->getRBraceLoc());
1148 
1149   if (D->isOriginalNamespace())
1150     Record.AddDeclRef(D->getAnonymousNamespace());
1151   Code = serialization::DECL_NAMESPACE;
1152 
1153   if (Writer.hasChain() && D->isAnonymousNamespace() &&
1154       D == D->getMostRecentDecl()) {
1155     // This is a most recent reopening of the anonymous namespace. If its parent
1156     // is in a previous PCH (or is the TU), mark that parent for update, because
1157     // the original namespace always points to the latest re-opening of its
1158     // anonymous namespace.
1159     Decl *Parent = cast<Decl>(
1160         D->getParent()->getRedeclContext()->getPrimaryContext());
1161     if (Parent->isFromASTFile() || isa<TranslationUnitDecl>(Parent)) {
1162       Writer.DeclUpdates[Parent].push_back(
1163           ASTWriter::DeclUpdate(UPD_CXX_ADDED_ANONYMOUS_NAMESPACE, D));
1164     }
1165   }
1166 }
1167 
1168 void ASTDeclWriter::VisitNamespaceAliasDecl(NamespaceAliasDecl *D) {
1169   VisitRedeclarable(D);
1170   VisitNamedDecl(D);
1171   Record.AddSourceLocation(D->getNamespaceLoc());
1172   Record.AddSourceLocation(D->getTargetNameLoc());
1173   Record.AddNestedNameSpecifierLoc(D->getQualifierLoc());
1174   Record.AddDeclRef(D->getNamespace());
1175   Code = serialization::DECL_NAMESPACE_ALIAS;
1176 }
1177 
1178 void ASTDeclWriter::VisitUsingDecl(UsingDecl *D) {
1179   VisitNamedDecl(D);
1180   Record.AddSourceLocation(D->getUsingLoc());
1181   Record.AddNestedNameSpecifierLoc(D->getQualifierLoc());
1182   Record.AddDeclarationNameLoc(D->DNLoc, D->getDeclName());
1183   Record.AddDeclRef(D->FirstUsingShadow.getPointer());
1184   Record.push_back(D->hasTypename());
1185   Record.AddDeclRef(Context.getInstantiatedFromUsingDecl(D));
1186   Code = serialization::DECL_USING;
1187 }
1188 
1189 void ASTDeclWriter::VisitUsingPackDecl(UsingPackDecl *D) {
1190   Record.push_back(D->NumExpansions);
1191   VisitNamedDecl(D);
1192   Record.AddDeclRef(D->getInstantiatedFromUsingDecl());
1193   for (auto *E : D->expansions())
1194     Record.AddDeclRef(E);
1195   Code = serialization::DECL_USING_PACK;
1196 }
1197 
1198 void ASTDeclWriter::VisitUsingShadowDecl(UsingShadowDecl *D) {
1199   VisitRedeclarable(D);
1200   VisitNamedDecl(D);
1201   Record.AddDeclRef(D->getTargetDecl());
1202   Record.push_back(D->getIdentifierNamespace());
1203   Record.AddDeclRef(D->UsingOrNextShadow);
1204   Record.AddDeclRef(Context.getInstantiatedFromUsingShadowDecl(D));
1205   Code = serialization::DECL_USING_SHADOW;
1206 }
1207 
1208 void ASTDeclWriter::VisitConstructorUsingShadowDecl(
1209     ConstructorUsingShadowDecl *D) {
1210   VisitUsingShadowDecl(D);
1211   Record.AddDeclRef(D->NominatedBaseClassShadowDecl);
1212   Record.AddDeclRef(D->ConstructedBaseClassShadowDecl);
1213   Record.push_back(D->IsVirtual);
1214   Code = serialization::DECL_CONSTRUCTOR_USING_SHADOW;
1215 }
1216 
1217 void ASTDeclWriter::VisitUsingDirectiveDecl(UsingDirectiveDecl *D) {
1218   VisitNamedDecl(D);
1219   Record.AddSourceLocation(D->getUsingLoc());
1220   Record.AddSourceLocation(D->getNamespaceKeyLocation());
1221   Record.AddNestedNameSpecifierLoc(D->getQualifierLoc());
1222   Record.AddDeclRef(D->getNominatedNamespace());
1223   Record.AddDeclRef(dyn_cast<Decl>(D->getCommonAncestor()));
1224   Code = serialization::DECL_USING_DIRECTIVE;
1225 }
1226 
1227 void ASTDeclWriter::VisitUnresolvedUsingValueDecl(UnresolvedUsingValueDecl *D) {
1228   VisitValueDecl(D);
1229   Record.AddSourceLocation(D->getUsingLoc());
1230   Record.AddNestedNameSpecifierLoc(D->getQualifierLoc());
1231   Record.AddDeclarationNameLoc(D->DNLoc, D->getDeclName());
1232   Record.AddSourceLocation(D->getEllipsisLoc());
1233   Code = serialization::DECL_UNRESOLVED_USING_VALUE;
1234 }
1235 
1236 void ASTDeclWriter::VisitUnresolvedUsingTypenameDecl(
1237                                                UnresolvedUsingTypenameDecl *D) {
1238   VisitTypeDecl(D);
1239   Record.AddSourceLocation(D->getTypenameLoc());
1240   Record.AddNestedNameSpecifierLoc(D->getQualifierLoc());
1241   Record.AddSourceLocation(D->getEllipsisLoc());
1242   Code = serialization::DECL_UNRESOLVED_USING_TYPENAME;
1243 }
1244 
1245 void ASTDeclWriter::VisitCXXRecordDecl(CXXRecordDecl *D) {
1246   VisitRecordDecl(D);
1247 
1248   enum {
1249     CXXRecNotTemplate = 0, CXXRecTemplate, CXXRecMemberSpecialization
1250   };
1251   if (ClassTemplateDecl *TemplD = D->getDescribedClassTemplate()) {
1252     Record.push_back(CXXRecTemplate);
1253     Record.AddDeclRef(TemplD);
1254   } else if (MemberSpecializationInfo *MSInfo
1255                = D->getMemberSpecializationInfo()) {
1256     Record.push_back(CXXRecMemberSpecialization);
1257     Record.AddDeclRef(MSInfo->getInstantiatedFrom());
1258     Record.push_back(MSInfo->getTemplateSpecializationKind());
1259     Record.AddSourceLocation(MSInfo->getPointOfInstantiation());
1260   } else {
1261     Record.push_back(CXXRecNotTemplate);
1262   }
1263 
1264   Record.push_back(D->isThisDeclarationADefinition());
1265   if (D->isThisDeclarationADefinition())
1266     Record.AddCXXDefinitionData(D);
1267 
1268   // Store (what we currently believe to be) the key function to avoid
1269   // deserializing every method so we can compute it.
1270   if (D->IsCompleteDefinition)
1271     Record.AddDeclRef(Context.getCurrentKeyFunction(D));
1272 
1273   Code = serialization::DECL_CXX_RECORD;
1274 }
1275 
1276 void ASTDeclWriter::VisitCXXMethodDecl(CXXMethodDecl *D) {
1277   VisitFunctionDecl(D);
1278   if (D->isCanonicalDecl()) {
1279     Record.push_back(D->size_overridden_methods());
1280     for (const CXXMethodDecl *MD : D->overridden_methods())
1281       Record.AddDeclRef(MD);
1282   } else {
1283     // We only need to record overridden methods once for the canonical decl.
1284     Record.push_back(0);
1285   }
1286 
1287   if (D->getDeclContext() == D->getLexicalDeclContext() &&
1288       D->getFirstDecl() == D->getMostRecentDecl() &&
1289       !D->isInvalidDecl() &&
1290       !D->hasAttrs() &&
1291       !D->isTopLevelDeclInObjCContainer() &&
1292       D->getDeclName().getNameKind() == DeclarationName::Identifier &&
1293       !D->hasExtInfo() &&
1294       !D->hasInheritedPrototype() &&
1295       D->hasWrittenPrototype())
1296     AbbrevToUse = Writer.getDeclCXXMethodAbbrev();
1297 
1298   Code = serialization::DECL_CXX_METHOD;
1299 }
1300 
1301 void ASTDeclWriter::VisitCXXConstructorDecl(CXXConstructorDecl *D) {
1302   if (auto Inherited = D->getInheritedConstructor()) {
1303     Record.AddDeclRef(Inherited.getShadowDecl());
1304     Record.AddDeclRef(Inherited.getConstructor());
1305     Code = serialization::DECL_CXX_INHERITED_CONSTRUCTOR;
1306   } else {
1307     Code = serialization::DECL_CXX_CONSTRUCTOR;
1308   }
1309 
1310   VisitCXXMethodDecl(D);
1311 
1312   Code = D->isInheritingConstructor()
1313              ? serialization::DECL_CXX_INHERITED_CONSTRUCTOR
1314              : serialization::DECL_CXX_CONSTRUCTOR;
1315 }
1316 
1317 void ASTDeclWriter::VisitCXXDestructorDecl(CXXDestructorDecl *D) {
1318   VisitCXXMethodDecl(D);
1319 
1320   Record.AddDeclRef(D->getOperatorDelete());
1321   if (D->getOperatorDelete())
1322     Record.AddStmt(D->getOperatorDeleteThisArg());
1323 
1324   Code = serialization::DECL_CXX_DESTRUCTOR;
1325 }
1326 
1327 void ASTDeclWriter::VisitCXXConversionDecl(CXXConversionDecl *D) {
1328   VisitCXXMethodDecl(D);
1329   Code = serialization::DECL_CXX_CONVERSION;
1330 }
1331 
1332 void ASTDeclWriter::VisitImportDecl(ImportDecl *D) {
1333   VisitDecl(D);
1334   Record.push_back(Writer.getSubmoduleID(D->getImportedModule()));
1335   ArrayRef<SourceLocation> IdentifierLocs = D->getIdentifierLocs();
1336   Record.push_back(!IdentifierLocs.empty());
1337   if (IdentifierLocs.empty()) {
1338     Record.AddSourceLocation(D->getLocEnd());
1339     Record.push_back(1);
1340   } else {
1341     for (unsigned I = 0, N = IdentifierLocs.size(); I != N; ++I)
1342       Record.AddSourceLocation(IdentifierLocs[I]);
1343     Record.push_back(IdentifierLocs.size());
1344   }
1345   // Note: the number of source locations must always be the last element in
1346   // the record.
1347   Code = serialization::DECL_IMPORT;
1348 }
1349 
1350 void ASTDeclWriter::VisitAccessSpecDecl(AccessSpecDecl *D) {
1351   VisitDecl(D);
1352   Record.AddSourceLocation(D->getColonLoc());
1353   Code = serialization::DECL_ACCESS_SPEC;
1354 }
1355 
1356 void ASTDeclWriter::VisitFriendDecl(FriendDecl *D) {
1357   // Record the number of friend type template parameter lists here
1358   // so as to simplify memory allocation during deserialization.
1359   Record.push_back(D->NumTPLists);
1360   VisitDecl(D);
1361   bool hasFriendDecl = D->Friend.is<NamedDecl*>();
1362   Record.push_back(hasFriendDecl);
1363   if (hasFriendDecl)
1364     Record.AddDeclRef(D->getFriendDecl());
1365   else
1366     Record.AddTypeSourceInfo(D->getFriendType());
1367   for (unsigned i = 0; i < D->NumTPLists; ++i)
1368     Record.AddTemplateParameterList(D->getFriendTypeTemplateParameterList(i));
1369   Record.AddDeclRef(D->getNextFriend());
1370   Record.push_back(D->UnsupportedFriend);
1371   Record.AddSourceLocation(D->FriendLoc);
1372   Code = serialization::DECL_FRIEND;
1373 }
1374 
1375 void ASTDeclWriter::VisitFriendTemplateDecl(FriendTemplateDecl *D) {
1376   VisitDecl(D);
1377   Record.push_back(D->getNumTemplateParameters());
1378   for (unsigned i = 0, e = D->getNumTemplateParameters(); i != e; ++i)
1379     Record.AddTemplateParameterList(D->getTemplateParameterList(i));
1380   Record.push_back(D->getFriendDecl() != nullptr);
1381   if (D->getFriendDecl())
1382     Record.AddDeclRef(D->getFriendDecl());
1383   else
1384     Record.AddTypeSourceInfo(D->getFriendType());
1385   Record.AddSourceLocation(D->getFriendLoc());
1386   Code = serialization::DECL_FRIEND_TEMPLATE;
1387 }
1388 
1389 void ASTDeclWriter::VisitTemplateDecl(TemplateDecl *D) {
1390   VisitNamedDecl(D);
1391 
1392   Record.AddDeclRef(D->getTemplatedDecl());
1393   Record.AddTemplateParameterList(D->getTemplateParameters());
1394 }
1395 
1396 void ASTDeclWriter::VisitRedeclarableTemplateDecl(RedeclarableTemplateDecl *D) {
1397   VisitRedeclarable(D);
1398 
1399   // Emit data to initialize CommonOrPrev before VisitTemplateDecl so that
1400   // getCommonPtr() can be used while this is still initializing.
1401   if (D->isFirstDecl()) {
1402     // This declaration owns the 'common' pointer, so serialize that data now.
1403     Record.AddDeclRef(D->getInstantiatedFromMemberTemplate());
1404     if (D->getInstantiatedFromMemberTemplate())
1405       Record.push_back(D->isMemberSpecialization());
1406   }
1407 
1408   VisitTemplateDecl(D);
1409   Record.push_back(D->getIdentifierNamespace());
1410 }
1411 
1412 void ASTDeclWriter::VisitClassTemplateDecl(ClassTemplateDecl *D) {
1413   VisitRedeclarableTemplateDecl(D);
1414 
1415   if (D->isFirstDecl())
1416     AddTemplateSpecializations(D);
1417   Code = serialization::DECL_CLASS_TEMPLATE;
1418 }
1419 
1420 void ASTDeclWriter::VisitClassTemplateSpecializationDecl(
1421                                            ClassTemplateSpecializationDecl *D) {
1422   RegisterTemplateSpecialization(D->getSpecializedTemplate(), D);
1423 
1424   VisitCXXRecordDecl(D);
1425 
1426   llvm::PointerUnion<ClassTemplateDecl *,
1427                      ClassTemplatePartialSpecializationDecl *> InstFrom
1428     = D->getSpecializedTemplateOrPartial();
1429   if (Decl *InstFromD = InstFrom.dyn_cast<ClassTemplateDecl *>()) {
1430     Record.AddDeclRef(InstFromD);
1431   } else {
1432     Record.AddDeclRef(InstFrom.get<ClassTemplatePartialSpecializationDecl *>());
1433     Record.AddTemplateArgumentList(&D->getTemplateInstantiationArgs());
1434   }
1435 
1436   Record.AddTemplateArgumentList(&D->getTemplateArgs());
1437   Record.AddSourceLocation(D->getPointOfInstantiation());
1438   Record.push_back(D->getSpecializationKind());
1439   Record.push_back(D->isCanonicalDecl());
1440 
1441   if (D->isCanonicalDecl()) {
1442     // When reading, we'll add it to the folding set of the following template.
1443     Record.AddDeclRef(D->getSpecializedTemplate()->getCanonicalDecl());
1444   }
1445 
1446   // Explicit info.
1447   Record.AddTypeSourceInfo(D->getTypeAsWritten());
1448   if (D->getTypeAsWritten()) {
1449     Record.AddSourceLocation(D->getExternLoc());
1450     Record.AddSourceLocation(D->getTemplateKeywordLoc());
1451   }
1452 
1453   Code = serialization::DECL_CLASS_TEMPLATE_SPECIALIZATION;
1454 }
1455 
1456 void ASTDeclWriter::VisitClassTemplatePartialSpecializationDecl(
1457                                     ClassTemplatePartialSpecializationDecl *D) {
1458   VisitClassTemplateSpecializationDecl(D);
1459 
1460   Record.AddTemplateParameterList(D->getTemplateParameters());
1461   Record.AddASTTemplateArgumentListInfo(D->getTemplateArgsAsWritten());
1462 
1463   // These are read/set from/to the first declaration.
1464   if (D->getPreviousDecl() == nullptr) {
1465     Record.AddDeclRef(D->getInstantiatedFromMember());
1466     Record.push_back(D->isMemberSpecialization());
1467   }
1468 
1469   Code = serialization::DECL_CLASS_TEMPLATE_PARTIAL_SPECIALIZATION;
1470 }
1471 
1472 void ASTDeclWriter::VisitVarTemplateDecl(VarTemplateDecl *D) {
1473   VisitRedeclarableTemplateDecl(D);
1474 
1475   if (D->isFirstDecl())
1476     AddTemplateSpecializations(D);
1477   Code = serialization::DECL_VAR_TEMPLATE;
1478 }
1479 
1480 void ASTDeclWriter::VisitVarTemplateSpecializationDecl(
1481     VarTemplateSpecializationDecl *D) {
1482   RegisterTemplateSpecialization(D->getSpecializedTemplate(), D);
1483 
1484   VisitVarDecl(D);
1485 
1486   llvm::PointerUnion<VarTemplateDecl *, VarTemplatePartialSpecializationDecl *>
1487   InstFrom = D->getSpecializedTemplateOrPartial();
1488   if (Decl *InstFromD = InstFrom.dyn_cast<VarTemplateDecl *>()) {
1489     Record.AddDeclRef(InstFromD);
1490   } else {
1491     Record.AddDeclRef(InstFrom.get<VarTemplatePartialSpecializationDecl *>());
1492     Record.AddTemplateArgumentList(&D->getTemplateInstantiationArgs());
1493   }
1494 
1495   // Explicit info.
1496   Record.AddTypeSourceInfo(D->getTypeAsWritten());
1497   if (D->getTypeAsWritten()) {
1498     Record.AddSourceLocation(D->getExternLoc());
1499     Record.AddSourceLocation(D->getTemplateKeywordLoc());
1500   }
1501 
1502   Record.AddTemplateArgumentList(&D->getTemplateArgs());
1503   Record.AddSourceLocation(D->getPointOfInstantiation());
1504   Record.push_back(D->getSpecializationKind());
1505   Record.push_back(D->IsCompleteDefinition);
1506   Record.push_back(D->isCanonicalDecl());
1507 
1508   if (D->isCanonicalDecl()) {
1509     // When reading, we'll add it to the folding set of the following template.
1510     Record.AddDeclRef(D->getSpecializedTemplate()->getCanonicalDecl());
1511   }
1512 
1513   Code = serialization::DECL_VAR_TEMPLATE_SPECIALIZATION;
1514 }
1515 
1516 void ASTDeclWriter::VisitVarTemplatePartialSpecializationDecl(
1517     VarTemplatePartialSpecializationDecl *D) {
1518   VisitVarTemplateSpecializationDecl(D);
1519 
1520   Record.AddTemplateParameterList(D->getTemplateParameters());
1521   Record.AddASTTemplateArgumentListInfo(D->getTemplateArgsAsWritten());
1522 
1523   // These are read/set from/to the first declaration.
1524   if (D->getPreviousDecl() == nullptr) {
1525     Record.AddDeclRef(D->getInstantiatedFromMember());
1526     Record.push_back(D->isMemberSpecialization());
1527   }
1528 
1529   Code = serialization::DECL_VAR_TEMPLATE_PARTIAL_SPECIALIZATION;
1530 }
1531 
1532 void ASTDeclWriter::VisitClassScopeFunctionSpecializationDecl(
1533                                     ClassScopeFunctionSpecializationDecl *D) {
1534   VisitDecl(D);
1535   Record.AddDeclRef(D->getSpecialization());
1536   Code = serialization::DECL_CLASS_SCOPE_FUNCTION_SPECIALIZATION;
1537 }
1538 
1539 
1540 void ASTDeclWriter::VisitFunctionTemplateDecl(FunctionTemplateDecl *D) {
1541   VisitRedeclarableTemplateDecl(D);
1542 
1543   if (D->isFirstDecl())
1544     AddTemplateSpecializations(D);
1545   Code = serialization::DECL_FUNCTION_TEMPLATE;
1546 }
1547 
1548 void ASTDeclWriter::VisitTemplateTypeParmDecl(TemplateTypeParmDecl *D) {
1549   VisitTypeDecl(D);
1550 
1551   Record.push_back(D->wasDeclaredWithTypename());
1552 
1553   bool OwnsDefaultArg = D->hasDefaultArgument() &&
1554                         !D->defaultArgumentWasInherited();
1555   Record.push_back(OwnsDefaultArg);
1556   if (OwnsDefaultArg)
1557     Record.AddTypeSourceInfo(D->getDefaultArgumentInfo());
1558 
1559   Code = serialization::DECL_TEMPLATE_TYPE_PARM;
1560 }
1561 
1562 void ASTDeclWriter::VisitNonTypeTemplateParmDecl(NonTypeTemplateParmDecl *D) {
1563   // For an expanded parameter pack, record the number of expansion types here
1564   // so that it's easier for deserialization to allocate the right amount of
1565   // memory.
1566   if (D->isExpandedParameterPack())
1567     Record.push_back(D->getNumExpansionTypes());
1568 
1569   VisitDeclaratorDecl(D);
1570   // TemplateParmPosition.
1571   Record.push_back(D->getDepth());
1572   Record.push_back(D->getPosition());
1573 
1574   if (D->isExpandedParameterPack()) {
1575     for (unsigned I = 0, N = D->getNumExpansionTypes(); I != N; ++I) {
1576       Record.AddTypeRef(D->getExpansionType(I));
1577       Record.AddTypeSourceInfo(D->getExpansionTypeSourceInfo(I));
1578     }
1579 
1580     Code = serialization::DECL_EXPANDED_NON_TYPE_TEMPLATE_PARM_PACK;
1581   } else {
1582     // Rest of NonTypeTemplateParmDecl.
1583     Record.push_back(D->isParameterPack());
1584     bool OwnsDefaultArg = D->hasDefaultArgument() &&
1585                           !D->defaultArgumentWasInherited();
1586     Record.push_back(OwnsDefaultArg);
1587     if (OwnsDefaultArg)
1588       Record.AddStmt(D->getDefaultArgument());
1589     Code = serialization::DECL_NON_TYPE_TEMPLATE_PARM;
1590   }
1591 }
1592 
1593 void ASTDeclWriter::VisitTemplateTemplateParmDecl(TemplateTemplateParmDecl *D) {
1594   // For an expanded parameter pack, record the number of expansion types here
1595   // so that it's easier for deserialization to allocate the right amount of
1596   // memory.
1597   if (D->isExpandedParameterPack())
1598     Record.push_back(D->getNumExpansionTemplateParameters());
1599 
1600   VisitTemplateDecl(D);
1601   // TemplateParmPosition.
1602   Record.push_back(D->getDepth());
1603   Record.push_back(D->getPosition());
1604 
1605   if (D->isExpandedParameterPack()) {
1606     for (unsigned I = 0, N = D->getNumExpansionTemplateParameters();
1607          I != N; ++I)
1608       Record.AddTemplateParameterList(D->getExpansionTemplateParameters(I));
1609     Code = serialization::DECL_EXPANDED_TEMPLATE_TEMPLATE_PARM_PACK;
1610   } else {
1611     // Rest of TemplateTemplateParmDecl.
1612     Record.push_back(D->isParameterPack());
1613     bool OwnsDefaultArg = D->hasDefaultArgument() &&
1614                           !D->defaultArgumentWasInherited();
1615     Record.push_back(OwnsDefaultArg);
1616     if (OwnsDefaultArg)
1617       Record.AddTemplateArgumentLoc(D->getDefaultArgument());
1618     Code = serialization::DECL_TEMPLATE_TEMPLATE_PARM;
1619   }
1620 }
1621 
1622 void ASTDeclWriter::VisitTypeAliasTemplateDecl(TypeAliasTemplateDecl *D) {
1623   VisitRedeclarableTemplateDecl(D);
1624   Code = serialization::DECL_TYPE_ALIAS_TEMPLATE;
1625 }
1626 
1627 void ASTDeclWriter::VisitStaticAssertDecl(StaticAssertDecl *D) {
1628   VisitDecl(D);
1629   Record.AddStmt(D->getAssertExpr());
1630   Record.push_back(D->isFailed());
1631   Record.AddStmt(D->getMessage());
1632   Record.AddSourceLocation(D->getRParenLoc());
1633   Code = serialization::DECL_STATIC_ASSERT;
1634 }
1635 
1636 /// \brief Emit the DeclContext part of a declaration context decl.
1637 void ASTDeclWriter::VisitDeclContext(DeclContext *DC) {
1638   Record.AddOffset(Writer.WriteDeclContextLexicalBlock(Context, DC));
1639   Record.AddOffset(Writer.WriteDeclContextVisibleBlock(Context, DC));
1640 }
1641 
1642 const Decl *ASTWriter::getFirstLocalDecl(const Decl *D) {
1643   assert(IsLocalDecl(D) && "expected a local declaration");
1644 
1645   const Decl *Canon = D->getCanonicalDecl();
1646   if (IsLocalDecl(Canon))
1647     return Canon;
1648 
1649   const Decl *&CacheEntry = FirstLocalDeclCache[Canon];
1650   if (CacheEntry)
1651     return CacheEntry;
1652 
1653   for (const Decl *Redecl = D; Redecl; Redecl = Redecl->getPreviousDecl())
1654     if (IsLocalDecl(Redecl))
1655       D = Redecl;
1656   return CacheEntry = D;
1657 }
1658 
1659 template <typename T>
1660 void ASTDeclWriter::VisitRedeclarable(Redeclarable<T> *D) {
1661   T *First = D->getFirstDecl();
1662   T *MostRecent = First->getMostRecentDecl();
1663   T *DAsT = static_cast<T *>(D);
1664   if (MostRecent != First) {
1665     assert(isRedeclarableDeclKind(DAsT->getKind()) &&
1666            "Not considered redeclarable?");
1667 
1668     Record.AddDeclRef(First);
1669 
1670     // Write out a list of local redeclarations of this declaration if it's the
1671     // first local declaration in the chain.
1672     const Decl *FirstLocal = Writer.getFirstLocalDecl(DAsT);
1673     if (DAsT == FirstLocal) {
1674       // Emit a list of all imported first declarations so that we can be sure
1675       // that all redeclarations visible to this module are before D in the
1676       // redecl chain.
1677       unsigned I = Record.size();
1678       Record.push_back(0);
1679       if (Writer.Chain)
1680         AddFirstDeclFromEachModule(DAsT, /*IncludeLocal*/false);
1681       // This is the number of imported first declarations + 1.
1682       Record[I] = Record.size() - I;
1683 
1684       // Collect the set of local redeclarations of this declaration, from
1685       // newest to oldest.
1686       ASTWriter::RecordData LocalRedecls;
1687       ASTRecordWriter LocalRedeclWriter(Record, LocalRedecls);
1688       for (const Decl *Prev = FirstLocal->getMostRecentDecl();
1689            Prev != FirstLocal; Prev = Prev->getPreviousDecl())
1690         if (!Prev->isFromASTFile())
1691           LocalRedeclWriter.AddDeclRef(Prev);
1692 
1693       // If we have any redecls, write them now as a separate record preceding
1694       // the declaration itself.
1695       if (LocalRedecls.empty())
1696         Record.push_back(0);
1697       else
1698         Record.AddOffset(LocalRedeclWriter.Emit(LOCAL_REDECLARATIONS));
1699     } else {
1700       Record.push_back(0);
1701       Record.AddDeclRef(FirstLocal);
1702     }
1703 
1704     // Make sure that we serialize both the previous and the most-recent
1705     // declarations, which (transitively) ensures that all declarations in the
1706     // chain get serialized.
1707     //
1708     // FIXME: This is not correct; when we reach an imported declaration we
1709     // won't emit its previous declaration.
1710     (void)Writer.GetDeclRef(D->getPreviousDecl());
1711     (void)Writer.GetDeclRef(MostRecent);
1712   } else {
1713     // We use the sentinel value 0 to indicate an only declaration.
1714     Record.push_back(0);
1715   }
1716 }
1717 
1718 void ASTDeclWriter::VisitOMPThreadPrivateDecl(OMPThreadPrivateDecl *D) {
1719   Record.push_back(D->varlist_size());
1720   VisitDecl(D);
1721   for (auto *I : D->varlists())
1722     Record.AddStmt(I);
1723   Code = serialization::DECL_OMP_THREADPRIVATE;
1724 }
1725 
1726 void ASTDeclWriter::VisitOMPDeclareReductionDecl(OMPDeclareReductionDecl *D) {
1727   VisitValueDecl(D);
1728   Record.AddSourceLocation(D->getLocStart());
1729   Record.AddStmt(D->getCombiner());
1730   Record.AddStmt(D->getInitializer());
1731   Record.push_back(D->getInitializerKind());
1732   Record.AddDeclRef(D->getPrevDeclInScope());
1733   Code = serialization::DECL_OMP_DECLARE_REDUCTION;
1734 }
1735 
1736 void ASTDeclWriter::VisitOMPCapturedExprDecl(OMPCapturedExprDecl *D) {
1737   VisitVarDecl(D);
1738   Code = serialization::DECL_OMP_CAPTUREDEXPR;
1739 }
1740 
1741 //===----------------------------------------------------------------------===//
1742 // ASTWriter Implementation
1743 //===----------------------------------------------------------------------===//
1744 
1745 void ASTWriter::WriteDeclAbbrevs() {
1746   using namespace llvm;
1747 
1748   std::shared_ptr<BitCodeAbbrev> Abv;
1749 
1750   // Abbreviation for DECL_FIELD
1751   Abv = std::make_shared<BitCodeAbbrev>();
1752   Abv->Add(BitCodeAbbrevOp(serialization::DECL_FIELD));
1753   // Decl
1754   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclContext
1755   Abv->Add(BitCodeAbbrevOp(0));                       // LexicalDeclContext
1756   Abv->Add(BitCodeAbbrevOp(0));                       // isInvalidDecl
1757   Abv->Add(BitCodeAbbrevOp(0));                       // HasAttrs
1758   Abv->Add(BitCodeAbbrevOp(0));                       // isImplicit
1759   Abv->Add(BitCodeAbbrevOp(0));                       // isUsed
1760   Abv->Add(BitCodeAbbrevOp(0));                       // isReferenced
1761   Abv->Add(BitCodeAbbrevOp(0));                   // TopLevelDeclInObjCContainer
1762   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2));  // AccessSpecifier
1763   Abv->Add(BitCodeAbbrevOp(0));                       // ModulePrivate
1764   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // SubmoduleID
1765   // NamedDecl
1766   Abv->Add(BitCodeAbbrevOp(0));                       // NameKind = Identifier
1767   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Name
1768   Abv->Add(BitCodeAbbrevOp(0));                       // AnonDeclNumber
1769   // ValueDecl
1770   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
1771   // DeclaratorDecl
1772   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // InnerStartLoc
1773   Abv->Add(BitCodeAbbrevOp(0));                       // hasExtInfo
1774   // FieldDecl
1775   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isMutable
1776   Abv->Add(BitCodeAbbrevOp(0));                       // InitStyle
1777   // Type Source Info
1778   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1779   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1780   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // TypeLoc
1781   DeclFieldAbbrev = Stream.EmitAbbrev(std::move(Abv));
1782 
1783   // Abbreviation for DECL_OBJC_IVAR
1784   Abv = std::make_shared<BitCodeAbbrev>();
1785   Abv->Add(BitCodeAbbrevOp(serialization::DECL_OBJC_IVAR));
1786   // Decl
1787   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclContext
1788   Abv->Add(BitCodeAbbrevOp(0));                       // LexicalDeclContext
1789   Abv->Add(BitCodeAbbrevOp(0));                       // isInvalidDecl
1790   Abv->Add(BitCodeAbbrevOp(0));                       // HasAttrs
1791   Abv->Add(BitCodeAbbrevOp(0));                       // isImplicit
1792   Abv->Add(BitCodeAbbrevOp(0));                       // isUsed
1793   Abv->Add(BitCodeAbbrevOp(0));                       // isReferenced
1794   Abv->Add(BitCodeAbbrevOp(0));                   // TopLevelDeclInObjCContainer
1795   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2));  // AccessSpecifier
1796   Abv->Add(BitCodeAbbrevOp(0));                       // ModulePrivate
1797   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // SubmoduleID
1798   // NamedDecl
1799   Abv->Add(BitCodeAbbrevOp(0));                       // NameKind = Identifier
1800   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Name
1801   Abv->Add(BitCodeAbbrevOp(0));                       // AnonDeclNumber
1802   // ValueDecl
1803   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
1804   // DeclaratorDecl
1805   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // InnerStartLoc
1806   Abv->Add(BitCodeAbbrevOp(0));                       // hasExtInfo
1807   // FieldDecl
1808   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isMutable
1809   Abv->Add(BitCodeAbbrevOp(0));                       // InitStyle
1810   // ObjC Ivar
1811   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // getAccessControl
1812   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // getSynthesize
1813   // Type Source Info
1814   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1815   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1816   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // TypeLoc
1817   DeclObjCIvarAbbrev = Stream.EmitAbbrev(std::move(Abv));
1818 
1819   // Abbreviation for DECL_ENUM
1820   Abv = std::make_shared<BitCodeAbbrev>();
1821   Abv->Add(BitCodeAbbrevOp(serialization::DECL_ENUM));
1822   // Redeclarable
1823   Abv->Add(BitCodeAbbrevOp(0));                       // No redeclaration
1824   // Decl
1825   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclContext
1826   Abv->Add(BitCodeAbbrevOp(0));                       // LexicalDeclContext
1827   Abv->Add(BitCodeAbbrevOp(0));                       // isInvalidDecl
1828   Abv->Add(BitCodeAbbrevOp(0));                       // HasAttrs
1829   Abv->Add(BitCodeAbbrevOp(0));                       // isImplicit
1830   Abv->Add(BitCodeAbbrevOp(0));                       // isUsed
1831   Abv->Add(BitCodeAbbrevOp(0));                       // isReferenced
1832   Abv->Add(BitCodeAbbrevOp(0));                   // TopLevelDeclInObjCContainer
1833   Abv->Add(BitCodeAbbrevOp(AS_none));                 // C++ AccessSpecifier
1834   Abv->Add(BitCodeAbbrevOp(0));                       // ModulePrivate
1835   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // SubmoduleID
1836   // NamedDecl
1837   Abv->Add(BitCodeAbbrevOp(0));                       // NameKind = Identifier
1838   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Name
1839   Abv->Add(BitCodeAbbrevOp(0));                       // AnonDeclNumber
1840   // TypeDecl
1841   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Source Location
1842   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type Ref
1843   // TagDecl
1844   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // IdentifierNamespace
1845   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // getTagKind
1846   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isCompleteDefinition
1847   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // EmbeddedInDeclarator
1848   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsFreeStanding
1849   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsCompleteDefinitionRequired
1850   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // SourceLocation
1851   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // SourceLocation
1852   Abv->Add(BitCodeAbbrevOp(0));                         // ExtInfoKind
1853   // EnumDecl
1854   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // AddTypeRef
1855   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // IntegerType
1856   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // getPromotionType
1857   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // getNumPositiveBits
1858   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // getNumNegativeBits
1859   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isScoped
1860   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isScopedUsingClassTag
1861   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isFixed
1862   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // InstantiatedMembEnum
1863   // DC
1864   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // LexicalOffset
1865   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // VisibleOffset
1866   DeclEnumAbbrev = Stream.EmitAbbrev(std::move(Abv));
1867 
1868   // Abbreviation for DECL_RECORD
1869   Abv = std::make_shared<BitCodeAbbrev>();
1870   Abv->Add(BitCodeAbbrevOp(serialization::DECL_RECORD));
1871   // Redeclarable
1872   Abv->Add(BitCodeAbbrevOp(0));                       // No redeclaration
1873   // Decl
1874   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclContext
1875   Abv->Add(BitCodeAbbrevOp(0));                       // LexicalDeclContext
1876   Abv->Add(BitCodeAbbrevOp(0));                       // isInvalidDecl
1877   Abv->Add(BitCodeAbbrevOp(0));                       // HasAttrs
1878   Abv->Add(BitCodeAbbrevOp(0));                       // isImplicit
1879   Abv->Add(BitCodeAbbrevOp(0));                       // isUsed
1880   Abv->Add(BitCodeAbbrevOp(0));                       // isReferenced
1881   Abv->Add(BitCodeAbbrevOp(0));                   // TopLevelDeclInObjCContainer
1882   Abv->Add(BitCodeAbbrevOp(AS_none));                 // C++ AccessSpecifier
1883   Abv->Add(BitCodeAbbrevOp(0));                       // ModulePrivate
1884   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // SubmoduleID
1885   // NamedDecl
1886   Abv->Add(BitCodeAbbrevOp(0));                       // NameKind = Identifier
1887   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Name
1888   Abv->Add(BitCodeAbbrevOp(0));                       // AnonDeclNumber
1889   // TypeDecl
1890   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Source Location
1891   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type Ref
1892   // TagDecl
1893   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // IdentifierNamespace
1894   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // getTagKind
1895   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isCompleteDefinition
1896   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // EmbeddedInDeclarator
1897   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsFreeStanding
1898   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsCompleteDefinitionRequired
1899   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // SourceLocation
1900   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // SourceLocation
1901   Abv->Add(BitCodeAbbrevOp(0));                         // ExtInfoKind
1902   // RecordDecl
1903   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // FlexibleArrayMember
1904   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // AnonymousStructUnion
1905   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // hasObjectMember
1906   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // hasVolatileMember
1907 
1908   // isNonTrivialToPrimitiveDefaultInitialize
1909   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
1910   // isNonTrivialToPrimitiveCopy
1911   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
1912   // isNonTrivialToPrimitiveDestroy
1913   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
1914   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // canPassInRegisters
1915 
1916   // DC
1917   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // LexicalOffset
1918   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // VisibleOffset
1919   DeclRecordAbbrev = Stream.EmitAbbrev(std::move(Abv));
1920 
1921   // Abbreviation for DECL_PARM_VAR
1922   Abv = std::make_shared<BitCodeAbbrev>();
1923   Abv->Add(BitCodeAbbrevOp(serialization::DECL_PARM_VAR));
1924   // Redeclarable
1925   Abv->Add(BitCodeAbbrevOp(0));                       // No redeclaration
1926   // Decl
1927   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclContext
1928   Abv->Add(BitCodeAbbrevOp(0));                       // LexicalDeclContext
1929   Abv->Add(BitCodeAbbrevOp(0));                       // isInvalidDecl
1930   Abv->Add(BitCodeAbbrevOp(0));                       // HasAttrs
1931   Abv->Add(BitCodeAbbrevOp(0));                       // isImplicit
1932   Abv->Add(BitCodeAbbrevOp(0));                       // isUsed
1933   Abv->Add(BitCodeAbbrevOp(0));                       // isReferenced
1934   Abv->Add(BitCodeAbbrevOp(0));                   // TopLevelDeclInObjCContainer
1935   Abv->Add(BitCodeAbbrevOp(AS_none));                 // C++ AccessSpecifier
1936   Abv->Add(BitCodeAbbrevOp(0));                       // ModulePrivate
1937   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // SubmoduleID
1938   // NamedDecl
1939   Abv->Add(BitCodeAbbrevOp(0));                       // NameKind = Identifier
1940   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Name
1941   Abv->Add(BitCodeAbbrevOp(0));                       // AnonDeclNumber
1942   // ValueDecl
1943   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
1944   // DeclaratorDecl
1945   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // InnerStartLoc
1946   Abv->Add(BitCodeAbbrevOp(0));                       // hasExtInfo
1947   // VarDecl
1948   Abv->Add(BitCodeAbbrevOp(0));                       // SClass
1949   Abv->Add(BitCodeAbbrevOp(0));                       // TSCSpec
1950   Abv->Add(BitCodeAbbrevOp(0));                       // InitStyle
1951   Abv->Add(BitCodeAbbrevOp(0));                       // Linkage
1952   Abv->Add(BitCodeAbbrevOp(0));                       // HasInit
1953   Abv->Add(BitCodeAbbrevOp(0));                   // HasMemberSpecializationInfo
1954   // ParmVarDecl
1955   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsObjCMethodParameter
1956   Abv->Add(BitCodeAbbrevOp(0));                       // ScopeDepth
1957   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // ScopeIndex
1958   Abv->Add(BitCodeAbbrevOp(0));                       // ObjCDeclQualifier
1959   Abv->Add(BitCodeAbbrevOp(0));                       // KNRPromoted
1960   Abv->Add(BitCodeAbbrevOp(0));                       // HasInheritedDefaultArg
1961   Abv->Add(BitCodeAbbrevOp(0));                   // HasUninstantiatedDefaultArg
1962   // Type Source Info
1963   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1964   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1965   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // TypeLoc
1966   DeclParmVarAbbrev = Stream.EmitAbbrev(std::move(Abv));
1967 
1968   // Abbreviation for DECL_TYPEDEF
1969   Abv = std::make_shared<BitCodeAbbrev>();
1970   Abv->Add(BitCodeAbbrevOp(serialization::DECL_TYPEDEF));
1971   // Redeclarable
1972   Abv->Add(BitCodeAbbrevOp(0));                       // No redeclaration
1973   // Decl
1974   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclContext
1975   Abv->Add(BitCodeAbbrevOp(0));                       // LexicalDeclContext
1976   Abv->Add(BitCodeAbbrevOp(0));                       // isInvalidDecl
1977   Abv->Add(BitCodeAbbrevOp(0));                       // HasAttrs
1978   Abv->Add(BitCodeAbbrevOp(0));                       // isImplicit
1979   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isUsed
1980   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isReferenced
1981   Abv->Add(BitCodeAbbrevOp(0));                   // TopLevelDeclInObjCContainer
1982   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2)); // C++ AccessSpecifier
1983   Abv->Add(BitCodeAbbrevOp(0));                       // ModulePrivate
1984   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // SubmoduleID
1985   // NamedDecl
1986   Abv->Add(BitCodeAbbrevOp(0));                       // NameKind = Identifier
1987   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Name
1988   Abv->Add(BitCodeAbbrevOp(0));                       // AnonDeclNumber
1989   // TypeDecl
1990   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Source Location
1991   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type Ref
1992   // TypedefDecl
1993   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1994   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // TypeLoc
1995   DeclTypedefAbbrev = Stream.EmitAbbrev(std::move(Abv));
1996 
1997   // Abbreviation for DECL_VAR
1998   Abv = std::make_shared<BitCodeAbbrev>();
1999   Abv->Add(BitCodeAbbrevOp(serialization::DECL_VAR));
2000   // Redeclarable
2001   Abv->Add(BitCodeAbbrevOp(0));                       // No redeclaration
2002   // Decl
2003   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclContext
2004   Abv->Add(BitCodeAbbrevOp(0));                       // LexicalDeclContext
2005   Abv->Add(BitCodeAbbrevOp(0));                       // isInvalidDecl
2006   Abv->Add(BitCodeAbbrevOp(0));                       // HasAttrs
2007   Abv->Add(BitCodeAbbrevOp(0));                       // isImplicit
2008   Abv->Add(BitCodeAbbrevOp(0));                       // isUsed
2009   Abv->Add(BitCodeAbbrevOp(0));                       // isReferenced
2010   Abv->Add(BitCodeAbbrevOp(0));                   // TopLevelDeclInObjCContainer
2011   Abv->Add(BitCodeAbbrevOp(AS_none));                 // C++ AccessSpecifier
2012   Abv->Add(BitCodeAbbrevOp(0));                       // ModulePrivate
2013   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // SubmoduleID
2014   // NamedDecl
2015   Abv->Add(BitCodeAbbrevOp(0));                       // NameKind = Identifier
2016   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Name
2017   Abv->Add(BitCodeAbbrevOp(0));                       // AnonDeclNumber
2018   // ValueDecl
2019   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
2020   // DeclaratorDecl
2021   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // InnerStartLoc
2022   Abv->Add(BitCodeAbbrevOp(0));                       // hasExtInfo
2023   // VarDecl
2024   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); // SClass
2025   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2)); // TSCSpec
2026   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2)); // InitStyle
2027   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsThisDeclarationADemotedDefinition
2028   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isExceptionVariable
2029   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isNRVOVariable
2030   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isCXXForRangeDecl
2031   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isARCPseudoStrong
2032   Abv->Add(BitCodeAbbrevOp(0));                         // isInline
2033   Abv->Add(BitCodeAbbrevOp(0));                         // isInlineSpecified
2034   Abv->Add(BitCodeAbbrevOp(0));                         // isConstexpr
2035   Abv->Add(BitCodeAbbrevOp(0));                         // isInitCapture
2036   Abv->Add(BitCodeAbbrevOp(0));                         // isPrevDeclInSameScope
2037   Abv->Add(BitCodeAbbrevOp(0));                         // ImplicitParamKind
2038   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); // Linkage
2039   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2)); // IsInitICE (local)
2040   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2)); // VarKind (local enum)
2041   // Type Source Info
2042   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
2043   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2044   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // TypeLoc
2045   DeclVarAbbrev = Stream.EmitAbbrev(std::move(Abv));
2046 
2047   // Abbreviation for DECL_CXX_METHOD
2048   Abv = std::make_shared<BitCodeAbbrev>();
2049   Abv->Add(BitCodeAbbrevOp(serialization::DECL_CXX_METHOD));
2050   // RedeclarableDecl
2051   Abv->Add(BitCodeAbbrevOp(0));                         // CanonicalDecl
2052   // Decl
2053   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // DeclContext
2054   Abv->Add(BitCodeAbbrevOp(0));                         // LexicalDeclContext
2055   Abv->Add(BitCodeAbbrevOp(0));                         // Invalid
2056   Abv->Add(BitCodeAbbrevOp(0));                         // HasAttrs
2057   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Implicit
2058   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Used
2059   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Referenced
2060   Abv->Add(BitCodeAbbrevOp(0));                         // InObjCContainer
2061   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2)); // Access
2062   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // ModulePrivate
2063   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // SubmoduleID
2064   // NamedDecl
2065   Abv->Add(BitCodeAbbrevOp(DeclarationName::Identifier)); // NameKind
2066   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // Identifier
2067   Abv->Add(BitCodeAbbrevOp(0));                         // AnonDeclNumber
2068   // ValueDecl
2069   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // Type
2070   // DeclaratorDecl
2071   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // InnerLocStart
2072   Abv->Add(BitCodeAbbrevOp(0));                         // HasExtInfo
2073   // FunctionDecl
2074   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 11)); // IDNS
2075   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); // StorageClass
2076   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Inline
2077   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // InlineSpecified
2078   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // ExplicitSpecified
2079   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // VirtualAsWritten
2080   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Pure
2081   Abv->Add(BitCodeAbbrevOp(0));                         // HasInheritedProto
2082   Abv->Add(BitCodeAbbrevOp(1));                         // HasWrittenProto
2083   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Deleted
2084   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Trivial
2085   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // TrivialForCall
2086   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Defaulted
2087   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // ExplicitlyDefaulted
2088   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // ImplicitReturnZero
2089   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Constexpr
2090   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // UsesSEHTry
2091   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // SkippedBody
2092   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // MultiVersion
2093   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // LateParsed
2094   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); // Linkage
2095   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // LocEnd
2096   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // ODRHash
2097   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); // TemplateKind
2098   // This Array slurps the rest of the record. Fortunately we want to encode
2099   // (nearly) all the remaining (variable number of) fields in the same way.
2100   //
2101   // This is the function template information if any, then
2102   //         NumParams and Params[] from FunctionDecl, and
2103   //         NumOverriddenMethods, OverriddenMethods[] from CXXMethodDecl.
2104   //
2105   //  Add an AbbrevOp for 'size then elements' and use it here.
2106   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2107   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
2108   DeclCXXMethodAbbrev = Stream.EmitAbbrev(std::move(Abv));
2109 
2110   // Abbreviation for EXPR_DECL_REF
2111   Abv = std::make_shared<BitCodeAbbrev>();
2112   Abv->Add(BitCodeAbbrevOp(serialization::EXPR_DECL_REF));
2113   //Stmt
2114   //Expr
2115   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
2116   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //TypeDependent
2117   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //ValueDependent
2118   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //InstantiationDependent
2119   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //UnexpandedParamPack
2120   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetValueKind
2121   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetObjectKind
2122   //DeclRefExpr
2123   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //HasQualifier
2124   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //GetDeclFound
2125   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //ExplicitTemplateArgs
2126   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //HadMultipleCandidates
2127   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
2128                            1)); // RefersToEnclosingVariableOrCapture
2129   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclRef
2130   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Location
2131   DeclRefExprAbbrev = Stream.EmitAbbrev(std::move(Abv));
2132 
2133   // Abbreviation for EXPR_INTEGER_LITERAL
2134   Abv = std::make_shared<BitCodeAbbrev>();
2135   Abv->Add(BitCodeAbbrevOp(serialization::EXPR_INTEGER_LITERAL));
2136   //Stmt
2137   //Expr
2138   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
2139   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //TypeDependent
2140   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //ValueDependent
2141   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //InstantiationDependent
2142   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //UnexpandedParamPack
2143   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetValueKind
2144   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetObjectKind
2145   //Integer Literal
2146   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Location
2147   Abv->Add(BitCodeAbbrevOp(32));                      // Bit Width
2148   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Value
2149   IntegerLiteralAbbrev = Stream.EmitAbbrev(std::move(Abv));
2150 
2151   // Abbreviation for EXPR_CHARACTER_LITERAL
2152   Abv = std::make_shared<BitCodeAbbrev>();
2153   Abv->Add(BitCodeAbbrevOp(serialization::EXPR_CHARACTER_LITERAL));
2154   //Stmt
2155   //Expr
2156   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
2157   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //TypeDependent
2158   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //ValueDependent
2159   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //InstantiationDependent
2160   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //UnexpandedParamPack
2161   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetValueKind
2162   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetObjectKind
2163   //Character Literal
2164   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // getValue
2165   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Location
2166   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); // getKind
2167   CharacterLiteralAbbrev = Stream.EmitAbbrev(std::move(Abv));
2168 
2169   // Abbreviation for EXPR_IMPLICIT_CAST
2170   Abv = std::make_shared<BitCodeAbbrev>();
2171   Abv->Add(BitCodeAbbrevOp(serialization::EXPR_IMPLICIT_CAST));
2172   // Stmt
2173   // Expr
2174   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
2175   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //TypeDependent
2176   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //ValueDependent
2177   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //InstantiationDependent
2178   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //UnexpandedParamPack
2179   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetValueKind
2180   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetObjectKind
2181   // CastExpr
2182   Abv->Add(BitCodeAbbrevOp(0)); // PathSize
2183   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 6)); // CastKind
2184   // ImplicitCastExpr
2185   ExprImplicitCastAbbrev = Stream.EmitAbbrev(std::move(Abv));
2186 
2187   Abv = std::make_shared<BitCodeAbbrev>();
2188   Abv->Add(BitCodeAbbrevOp(serialization::DECL_CONTEXT_LEXICAL));
2189   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
2190   DeclContextLexicalAbbrev = Stream.EmitAbbrev(std::move(Abv));
2191 
2192   Abv = std::make_shared<BitCodeAbbrev>();
2193   Abv->Add(BitCodeAbbrevOp(serialization::DECL_CONTEXT_VISIBLE));
2194   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
2195   DeclContextVisibleLookupAbbrev = Stream.EmitAbbrev(std::move(Abv));
2196 }
2197 
2198 /// isRequiredDecl - Check if this is a "required" Decl, which must be seen by
2199 /// consumers of the AST.
2200 ///
2201 /// Such decls will always be deserialized from the AST file, so we would like
2202 /// this to be as restrictive as possible. Currently the predicate is driven by
2203 /// code generation requirements, if other clients have a different notion of
2204 /// what is "required" then we may have to consider an alternate scheme where
2205 /// clients can iterate over the top-level decls and get information on them,
2206 /// without necessary deserializing them. We could explicitly require such
2207 /// clients to use a separate API call to "realize" the decl. This should be
2208 /// relatively painless since they would presumably only do it for top-level
2209 /// decls.
2210 static bool isRequiredDecl(const Decl *D, ASTContext &Context,
2211                            bool WritingModule) {
2212   // An ObjCMethodDecl is never considered as "required" because its
2213   // implementation container always is.
2214 
2215   // File scoped assembly or obj-c or OMP declare target implementation must be
2216   // seen.
2217   if (isa<FileScopeAsmDecl>(D) || isa<ObjCImplDecl>(D) ||
2218       D->hasAttr<OMPDeclareTargetDeclAttr>())
2219     return true;
2220 
2221   if (WritingModule && (isa<VarDecl>(D) || isa<ImportDecl>(D))) {
2222     // These declarations are part of the module initializer, and are emitted
2223     // if and when the module is imported, rather than being emitted eagerly.
2224     return false;
2225   }
2226 
2227   return Context.DeclMustBeEmitted(D);
2228 }
2229 
2230 void ASTWriter::WriteDecl(ASTContext &Context, Decl *D) {
2231   PrettyDeclStackTraceEntry CrashInfo(Context, D, SourceLocation(),
2232                                       "serializing");
2233 
2234   // Determine the ID for this declaration.
2235   serialization::DeclID ID;
2236   assert(!D->isFromASTFile() && "should not be emitting imported decl");
2237   serialization::DeclID &IDR = DeclIDs[D];
2238   if (IDR == 0)
2239     IDR = NextDeclID++;
2240 
2241   ID = IDR;
2242 
2243   assert(ID >= FirstDeclID && "invalid decl ID");
2244 
2245   RecordData Record;
2246   ASTDeclWriter W(*this, Context, Record);
2247 
2248   // Build a record for this declaration
2249   W.Visit(D);
2250 
2251   // Emit this declaration to the bitstream.
2252   uint64_t Offset = W.Emit(D);
2253 
2254   // Record the offset for this declaration
2255   SourceLocation Loc = D->getLocation();
2256   unsigned Index = ID - FirstDeclID;
2257   if (DeclOffsets.size() == Index)
2258     DeclOffsets.push_back(DeclOffset(Loc, Offset));
2259   else if (DeclOffsets.size() < Index) {
2260     // FIXME: Can/should this happen?
2261     DeclOffsets.resize(Index+1);
2262     DeclOffsets[Index].setLocation(Loc);
2263     DeclOffsets[Index].BitOffset = Offset;
2264   } else {
2265     llvm_unreachable("declarations should be emitted in ID order");
2266   }
2267 
2268   SourceManager &SM = Context.getSourceManager();
2269   if (Loc.isValid() && SM.isLocalSourceLocation(Loc))
2270     associateDeclWithFile(D, ID);
2271 
2272   // Note declarations that should be deserialized eagerly so that we can add
2273   // them to a record in the AST file later.
2274   if (isRequiredDecl(D, Context, WritingModule))
2275     EagerlyDeserializedDecls.push_back(ID);
2276 }
2277 
2278 void ASTRecordWriter::AddFunctionDefinition(const FunctionDecl *FD) {
2279   // Switch case IDs are per function body.
2280   Writer->ClearSwitchCaseIDs();
2281 
2282   assert(FD->doesThisDeclarationHaveABody());
2283   bool ModulesCodegen = false;
2284   if (Writer->WritingModule && !FD->isDependentContext()) {
2285     Optional<GVALinkage> Linkage;
2286     if (Writer->WritingModule->Kind == Module::ModuleInterfaceUnit) {
2287       // When building a C++ Modules TS module interface unit, a strong
2288       // definition in the module interface is provided by the compilation of
2289       // that module interface unit, not by its users. (Inline functions are
2290       // still emitted in module users.)
2291       Linkage = Writer->Context->GetGVALinkageForFunction(FD);
2292       ModulesCodegen = *Linkage == GVA_StrongExternal;
2293     }
2294     if (Writer->Context->getLangOpts().ModulesCodegen) {
2295       // Under -fmodules-codegen, codegen is performed for all non-internal,
2296       // non-always_inline functions.
2297       if (!FD->hasAttr<AlwaysInlineAttr>()) {
2298         if (!Linkage)
2299           Linkage = Writer->Context->GetGVALinkageForFunction(FD);
2300         ModulesCodegen = *Linkage != GVA_Internal;
2301       }
2302     }
2303   }
2304   Record->push_back(ModulesCodegen);
2305   if (ModulesCodegen)
2306     Writer->ModularCodegenDecls.push_back(Writer->GetDeclRef(FD));
2307   if (auto *CD = dyn_cast<CXXConstructorDecl>(FD)) {
2308     Record->push_back(CD->getNumCtorInitializers());
2309     if (CD->getNumCtorInitializers())
2310       AddCXXCtorInitializers(
2311           llvm::makeArrayRef(CD->init_begin(), CD->init_end()));
2312   }
2313   AddStmt(FD->getBody());
2314 }
2315