1 //===--- ASTWriterDecl.cpp - Declaration Serialization --------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 //  This file implements serialization for Declarations.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "ASTCommon.h"
14 #include "clang/AST/Attr.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/OpenMPClause.h"
21 #include "clang/AST/PrettyDeclStackTrace.h"
22 #include "clang/Basic/SourceManager.h"
23 #include "clang/Serialization/ASTReader.h"
24 #include "clang/Serialization/ASTRecordWriter.h"
25 #include "llvm/Bitstream/BitstreamWriter.h"
26 #include "llvm/Support/ErrorHandling.h"
27 using namespace clang;
28 using namespace serialization;
29 
30 //===----------------------------------------------------------------------===//
31 // Declaration serialization
32 //===----------------------------------------------------------------------===//
33 
34 namespace clang {
35   class ASTDeclWriter : public DeclVisitor<ASTDeclWriter, void> {
36     ASTWriter &Writer;
37     ASTContext &Context;
38     ASTRecordWriter Record;
39 
40     serialization::DeclCode Code;
41     unsigned AbbrevToUse;
42 
43   public:
44     ASTDeclWriter(ASTWriter &Writer, ASTContext &Context,
45                   ASTWriter::RecordDataImpl &Record)
46         : Writer(Writer), Context(Context), Record(Writer, Record),
47           Code((serialization::DeclCode)0), AbbrevToUse(0) {}
48 
49     uint64_t Emit(Decl *D) {
50       if (!Code)
51         llvm::report_fatal_error(StringRef("unexpected declaration kind '") +
52             D->getDeclKindName() + "'");
53       return Record.Emit(Code, AbbrevToUse);
54     }
55 
56     void Visit(Decl *D);
57 
58     void VisitDecl(Decl *D);
59     void VisitPragmaCommentDecl(PragmaCommentDecl *D);
60     void VisitPragmaDetectMismatchDecl(PragmaDetectMismatchDecl *D);
61     void VisitTranslationUnitDecl(TranslationUnitDecl *D);
62     void VisitNamedDecl(NamedDecl *D);
63     void VisitLabelDecl(LabelDecl *LD);
64     void VisitNamespaceDecl(NamespaceDecl *D);
65     void VisitUsingDirectiveDecl(UsingDirectiveDecl *D);
66     void VisitNamespaceAliasDecl(NamespaceAliasDecl *D);
67     void VisitTypeDecl(TypeDecl *D);
68     void VisitTypedefNameDecl(TypedefNameDecl *D);
69     void VisitTypedefDecl(TypedefDecl *D);
70     void VisitTypeAliasDecl(TypeAliasDecl *D);
71     void VisitUnresolvedUsingTypenameDecl(UnresolvedUsingTypenameDecl *D);
72     void VisitTagDecl(TagDecl *D);
73     void VisitEnumDecl(EnumDecl *D);
74     void VisitRecordDecl(RecordDecl *D);
75     void VisitCXXRecordDecl(CXXRecordDecl *D);
76     void VisitClassTemplateSpecializationDecl(
77                                             ClassTemplateSpecializationDecl *D);
78     void VisitClassTemplatePartialSpecializationDecl(
79                                      ClassTemplatePartialSpecializationDecl *D);
80     void VisitVarTemplateSpecializationDecl(VarTemplateSpecializationDecl *D);
81     void VisitVarTemplatePartialSpecializationDecl(
82         VarTemplatePartialSpecializationDecl *D);
83     void VisitClassScopeFunctionSpecializationDecl(
84                                        ClassScopeFunctionSpecializationDecl *D);
85     void VisitTemplateTypeParmDecl(TemplateTypeParmDecl *D);
86     void VisitValueDecl(ValueDecl *D);
87     void VisitEnumConstantDecl(EnumConstantDecl *D);
88     void VisitUnresolvedUsingValueDecl(UnresolvedUsingValueDecl *D);
89     void VisitDeclaratorDecl(DeclaratorDecl *D);
90     void VisitFunctionDecl(FunctionDecl *D);
91     void VisitCXXDeductionGuideDecl(CXXDeductionGuideDecl *D);
92     void VisitCXXMethodDecl(CXXMethodDecl *D);
93     void VisitCXXConstructorDecl(CXXConstructorDecl *D);
94     void VisitCXXDestructorDecl(CXXDestructorDecl *D);
95     void VisitCXXConversionDecl(CXXConversionDecl *D);
96     void VisitFieldDecl(FieldDecl *D);
97     void VisitMSPropertyDecl(MSPropertyDecl *D);
98     void VisitMSGuidDecl(MSGuidDecl *D);
99     void VisitTemplateParamObjectDecl(TemplateParamObjectDecl *D);
100     void VisitIndirectFieldDecl(IndirectFieldDecl *D);
101     void VisitVarDecl(VarDecl *D);
102     void VisitImplicitParamDecl(ImplicitParamDecl *D);
103     void VisitParmVarDecl(ParmVarDecl *D);
104     void VisitDecompositionDecl(DecompositionDecl *D);
105     void VisitBindingDecl(BindingDecl *D);
106     void VisitNonTypeTemplateParmDecl(NonTypeTemplateParmDecl *D);
107     void VisitTemplateDecl(TemplateDecl *D);
108     void VisitConceptDecl(ConceptDecl *D);
109     void VisitRequiresExprBodyDecl(RequiresExprBodyDecl *D);
110     void VisitRedeclarableTemplateDecl(RedeclarableTemplateDecl *D);
111     void VisitClassTemplateDecl(ClassTemplateDecl *D);
112     void VisitVarTemplateDecl(VarTemplateDecl *D);
113     void VisitFunctionTemplateDecl(FunctionTemplateDecl *D);
114     void VisitTemplateTemplateParmDecl(TemplateTemplateParmDecl *D);
115     void VisitTypeAliasTemplateDecl(TypeAliasTemplateDecl *D);
116     void VisitUsingDecl(UsingDecl *D);
117     void VisitUsingPackDecl(UsingPackDecl *D);
118     void VisitUsingShadowDecl(UsingShadowDecl *D);
119     void VisitConstructorUsingShadowDecl(ConstructorUsingShadowDecl *D);
120     void VisitLinkageSpecDecl(LinkageSpecDecl *D);
121     void VisitExportDecl(ExportDecl *D);
122     void VisitFileScopeAsmDecl(FileScopeAsmDecl *D);
123     void VisitImportDecl(ImportDecl *D);
124     void VisitAccessSpecDecl(AccessSpecDecl *D);
125     void VisitFriendDecl(FriendDecl *D);
126     void VisitFriendTemplateDecl(FriendTemplateDecl *D);
127     void VisitStaticAssertDecl(StaticAssertDecl *D);
128     void VisitBlockDecl(BlockDecl *D);
129     void VisitCapturedDecl(CapturedDecl *D);
130     void VisitEmptyDecl(EmptyDecl *D);
131     void VisitLifetimeExtendedTemporaryDecl(LifetimeExtendedTemporaryDecl *D);
132 
133     void VisitDeclContext(DeclContext *DC);
134     template <typename T> void VisitRedeclarable(Redeclarable<T> *D);
135 
136 
137     // FIXME: Put in the same order is DeclNodes.td?
138     void VisitObjCMethodDecl(ObjCMethodDecl *D);
139     void VisitObjCTypeParamDecl(ObjCTypeParamDecl *D);
140     void VisitObjCContainerDecl(ObjCContainerDecl *D);
141     void VisitObjCInterfaceDecl(ObjCInterfaceDecl *D);
142     void VisitObjCIvarDecl(ObjCIvarDecl *D);
143     void VisitObjCProtocolDecl(ObjCProtocolDecl *D);
144     void VisitObjCAtDefsFieldDecl(ObjCAtDefsFieldDecl *D);
145     void VisitObjCCategoryDecl(ObjCCategoryDecl *D);
146     void VisitObjCImplDecl(ObjCImplDecl *D);
147     void VisitObjCCategoryImplDecl(ObjCCategoryImplDecl *D);
148     void VisitObjCImplementationDecl(ObjCImplementationDecl *D);
149     void VisitObjCCompatibleAliasDecl(ObjCCompatibleAliasDecl *D);
150     void VisitObjCPropertyDecl(ObjCPropertyDecl *D);
151     void VisitObjCPropertyImplDecl(ObjCPropertyImplDecl *D);
152     void VisitOMPThreadPrivateDecl(OMPThreadPrivateDecl *D);
153     void VisitOMPAllocateDecl(OMPAllocateDecl *D);
154     void VisitOMPRequiresDecl(OMPRequiresDecl *D);
155     void VisitOMPDeclareReductionDecl(OMPDeclareReductionDecl *D);
156     void VisitOMPDeclareMapperDecl(OMPDeclareMapperDecl *D);
157     void VisitOMPCapturedExprDecl(OMPCapturedExprDecl *D);
158 
159     /// Add an Objective-C type parameter list to the given record.
160     void AddObjCTypeParamList(ObjCTypeParamList *typeParams) {
161       // Empty type parameter list.
162       if (!typeParams) {
163         Record.push_back(0);
164         return;
165       }
166 
167       Record.push_back(typeParams->size());
168       for (auto typeParam : *typeParams) {
169         Record.AddDeclRef(typeParam);
170       }
171       Record.AddSourceLocation(typeParams->getLAngleLoc());
172       Record.AddSourceLocation(typeParams->getRAngleLoc());
173     }
174 
175     /// Add to the record the first declaration from each module file that
176     /// provides a declaration of D. The intent is to provide a sufficient
177     /// set such that reloading this set will load all current redeclarations.
178     void AddFirstDeclFromEachModule(const Decl *D, bool IncludeLocal) {
179       llvm::MapVector<ModuleFile*, const Decl*> Firsts;
180       // FIXME: We can skip entries that we know are implied by others.
181       for (const Decl *R = D->getMostRecentDecl(); R; R = R->getPreviousDecl()) {
182         if (R->isFromASTFile())
183           Firsts[Writer.Chain->getOwningModuleFile(R)] = R;
184         else if (IncludeLocal)
185           Firsts[nullptr] = R;
186       }
187       for (const auto &F : Firsts)
188         Record.AddDeclRef(F.second);
189     }
190 
191     /// Get the specialization decl from an entry in the specialization list.
192     template <typename EntryType>
193     typename RedeclarableTemplateDecl::SpecEntryTraits<EntryType>::DeclType *
194     getSpecializationDecl(EntryType &T) {
195       return RedeclarableTemplateDecl::SpecEntryTraits<EntryType>::getDecl(&T);
196     }
197 
198     /// Get the list of partial specializations from a template's common ptr.
199     template<typename T>
200     decltype(T::PartialSpecializations) &getPartialSpecializations(T *Common) {
201       return Common->PartialSpecializations;
202     }
203     ArrayRef<Decl> getPartialSpecializations(FunctionTemplateDecl::Common *) {
204       return None;
205     }
206 
207     template<typename DeclTy>
208     void AddTemplateSpecializations(DeclTy *D) {
209       auto *Common = D->getCommonPtr();
210 
211       // If we have any lazy specializations, and the external AST source is
212       // our chained AST reader, we can just write out the DeclIDs. Otherwise,
213       // we need to resolve them to actual declarations.
214       if (Writer.Chain != Writer.Context->getExternalSource() &&
215           Common->LazySpecializations) {
216         D->LoadLazySpecializations();
217         assert(!Common->LazySpecializations);
218       }
219 
220       ArrayRef<DeclID> LazySpecializations;
221       if (auto *LS = Common->LazySpecializations)
222         LazySpecializations = llvm::makeArrayRef(LS + 1, LS[0]);
223 
224       // Add a slot to the record for the number of specializations.
225       unsigned I = Record.size();
226       Record.push_back(0);
227 
228       // AddFirstDeclFromEachModule might trigger deserialization, invalidating
229       // *Specializations iterators.
230       llvm::SmallVector<const Decl*, 16> Specs;
231       for (auto &Entry : Common->Specializations)
232         Specs.push_back(getSpecializationDecl(Entry));
233       for (auto &Entry : getPartialSpecializations(Common))
234         Specs.push_back(getSpecializationDecl(Entry));
235 
236       for (auto *D : Specs) {
237         assert(D->isCanonicalDecl() && "non-canonical decl in set");
238         AddFirstDeclFromEachModule(D, /*IncludeLocal*/true);
239       }
240       Record.append(LazySpecializations.begin(), LazySpecializations.end());
241 
242       // Update the size entry we added earlier.
243       Record[I] = Record.size() - I - 1;
244     }
245 
246     /// Ensure that this template specialization is associated with the specified
247     /// template on reload.
248     void RegisterTemplateSpecialization(const Decl *Template,
249                                         const Decl *Specialization) {
250       Template = Template->getCanonicalDecl();
251 
252       // If the canonical template is local, we'll write out this specialization
253       // when we emit it.
254       // FIXME: We can do the same thing if there is any local declaration of
255       // the template, to avoid emitting an update record.
256       if (!Template->isFromASTFile())
257         return;
258 
259       // We only need to associate the first local declaration of the
260       // specialization. The other declarations will get pulled in by it.
261       if (Writer.getFirstLocalDecl(Specialization) != Specialization)
262         return;
263 
264       Writer.DeclUpdates[Template].push_back(ASTWriter::DeclUpdate(
265           UPD_CXX_ADDED_TEMPLATE_SPECIALIZATION, Specialization));
266     }
267   };
268 }
269 
270 void ASTDeclWriter::Visit(Decl *D) {
271   DeclVisitor<ASTDeclWriter>::Visit(D);
272 
273   // Source locations require array (variable-length) abbreviations.  The
274   // abbreviation infrastructure requires that arrays are encoded last, so
275   // we handle it here in the case of those classes derived from DeclaratorDecl
276   if (DeclaratorDecl *DD = dyn_cast<DeclaratorDecl>(D)) {
277     if (auto *TInfo = DD->getTypeSourceInfo())
278       Record.AddTypeLoc(TInfo->getTypeLoc());
279   }
280 
281   // Handle FunctionDecl's body here and write it after all other Stmts/Exprs
282   // have been written. We want it last because we will not read it back when
283   // retrieving it from the AST, we'll just lazily set the offset.
284   if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
285     Record.push_back(FD->doesThisDeclarationHaveABody());
286     if (FD->doesThisDeclarationHaveABody())
287       Record.AddFunctionDefinition(FD);
288   }
289 
290   // If this declaration is also a DeclContext, write blocks for the
291   // declarations that lexically stored inside its context and those
292   // declarations that are visible from its context.
293   if (DeclContext *DC = dyn_cast<DeclContext>(D))
294     VisitDeclContext(DC);
295 }
296 
297 void ASTDeclWriter::VisitDecl(Decl *D) {
298   Record.AddDeclRef(cast_or_null<Decl>(D->getDeclContext()));
299   if (D->getDeclContext() != D->getLexicalDeclContext())
300     Record.AddDeclRef(cast_or_null<Decl>(D->getLexicalDeclContext()));
301   else
302     Record.push_back(0);
303   Record.push_back(D->isInvalidDecl());
304   Record.push_back(D->hasAttrs());
305   if (D->hasAttrs())
306     Record.AddAttributes(D->getAttrs());
307   Record.push_back(D->isImplicit());
308   Record.push_back(D->isUsed(false));
309   Record.push_back(D->isReferenced());
310   Record.push_back(D->isTopLevelDeclInObjCContainer());
311   Record.push_back(D->getAccess());
312   Record.push_back(D->isModulePrivate());
313   Record.push_back(Writer.getSubmoduleID(D->getOwningModule()));
314 
315   // If this declaration injected a name into a context different from its
316   // lexical context, and that context is an imported namespace, we need to
317   // update its visible declarations to include this name.
318   //
319   // This happens when we instantiate a class with a friend declaration or a
320   // function with a local extern declaration, for instance.
321   //
322   // FIXME: Can we handle this in AddedVisibleDecl instead?
323   if (D->isOutOfLine()) {
324     auto *DC = D->getDeclContext();
325     while (auto *NS = dyn_cast<NamespaceDecl>(DC->getRedeclContext())) {
326       if (!NS->isFromASTFile())
327         break;
328       Writer.UpdatedDeclContexts.insert(NS->getPrimaryContext());
329       if (!NS->isInlineNamespace())
330         break;
331       DC = NS->getParent();
332     }
333   }
334 }
335 
336 void ASTDeclWriter::VisitPragmaCommentDecl(PragmaCommentDecl *D) {
337   StringRef Arg = D->getArg();
338   Record.push_back(Arg.size());
339   VisitDecl(D);
340   Record.AddSourceLocation(D->getBeginLoc());
341   Record.push_back(D->getCommentKind());
342   Record.AddString(Arg);
343   Code = serialization::DECL_PRAGMA_COMMENT;
344 }
345 
346 void ASTDeclWriter::VisitPragmaDetectMismatchDecl(
347     PragmaDetectMismatchDecl *D) {
348   StringRef Name = D->getName();
349   StringRef Value = D->getValue();
350   Record.push_back(Name.size() + 1 + Value.size());
351   VisitDecl(D);
352   Record.AddSourceLocation(D->getBeginLoc());
353   Record.AddString(Name);
354   Record.AddString(Value);
355   Code = serialization::DECL_PRAGMA_DETECT_MISMATCH;
356 }
357 
358 void ASTDeclWriter::VisitTranslationUnitDecl(TranslationUnitDecl *D) {
359   llvm_unreachable("Translation units aren't directly serialized");
360 }
361 
362 void ASTDeclWriter::VisitNamedDecl(NamedDecl *D) {
363   VisitDecl(D);
364   Record.AddDeclarationName(D->getDeclName());
365   Record.push_back(needsAnonymousDeclarationNumber(D)
366                        ? Writer.getAnonymousDeclarationNumber(D)
367                        : 0);
368 }
369 
370 void ASTDeclWriter::VisitTypeDecl(TypeDecl *D) {
371   VisitNamedDecl(D);
372   Record.AddSourceLocation(D->getBeginLoc());
373   Record.AddTypeRef(QualType(D->getTypeForDecl(), 0));
374 }
375 
376 void ASTDeclWriter::VisitTypedefNameDecl(TypedefNameDecl *D) {
377   VisitRedeclarable(D);
378   VisitTypeDecl(D);
379   Record.AddTypeSourceInfo(D->getTypeSourceInfo());
380   Record.push_back(D->isModed());
381   if (D->isModed())
382     Record.AddTypeRef(D->getUnderlyingType());
383   Record.AddDeclRef(D->getAnonDeclWithTypedefName(false));
384 }
385 
386 void ASTDeclWriter::VisitTypedefDecl(TypedefDecl *D) {
387   VisitTypedefNameDecl(D);
388   if (D->getDeclContext() == D->getLexicalDeclContext() &&
389       !D->hasAttrs() &&
390       !D->isImplicit() &&
391       D->getFirstDecl() == D->getMostRecentDecl() &&
392       !D->isInvalidDecl() &&
393       !D->isTopLevelDeclInObjCContainer() &&
394       !D->isModulePrivate() &&
395       !needsAnonymousDeclarationNumber(D) &&
396       D->getDeclName().getNameKind() == DeclarationName::Identifier)
397     AbbrevToUse = Writer.getDeclTypedefAbbrev();
398 
399   Code = serialization::DECL_TYPEDEF;
400 }
401 
402 void ASTDeclWriter::VisitTypeAliasDecl(TypeAliasDecl *D) {
403   VisitTypedefNameDecl(D);
404   Record.AddDeclRef(D->getDescribedAliasTemplate());
405   Code = serialization::DECL_TYPEALIAS;
406 }
407 
408 void ASTDeclWriter::VisitTagDecl(TagDecl *D) {
409   VisitRedeclarable(D);
410   VisitTypeDecl(D);
411   Record.push_back(D->getIdentifierNamespace());
412   Record.push_back((unsigned)D->getTagKind()); // FIXME: stable encoding
413   if (!isa<CXXRecordDecl>(D))
414     Record.push_back(D->isCompleteDefinition());
415   Record.push_back(D->isEmbeddedInDeclarator());
416   Record.push_back(D->isFreeStanding());
417   Record.push_back(D->isCompleteDefinitionRequired());
418   Record.AddSourceRange(D->getBraceRange());
419 
420   if (D->hasExtInfo()) {
421     Record.push_back(1);
422     Record.AddQualifierInfo(*D->getExtInfo());
423   } else if (auto *TD = D->getTypedefNameForAnonDecl()) {
424     Record.push_back(2);
425     Record.AddDeclRef(TD);
426     Record.AddIdentifierRef(TD->getDeclName().getAsIdentifierInfo());
427   } else {
428     Record.push_back(0);
429   }
430 }
431 
432 void ASTDeclWriter::VisitEnumDecl(EnumDecl *D) {
433   VisitTagDecl(D);
434   Record.AddTypeSourceInfo(D->getIntegerTypeSourceInfo());
435   if (!D->getIntegerTypeSourceInfo())
436     Record.AddTypeRef(D->getIntegerType());
437   Record.AddTypeRef(D->getPromotionType());
438   Record.push_back(D->getNumPositiveBits());
439   Record.push_back(D->getNumNegativeBits());
440   Record.push_back(D->isScoped());
441   Record.push_back(D->isScopedUsingClassTag());
442   Record.push_back(D->isFixed());
443   Record.push_back(D->getODRHash());
444 
445   if (MemberSpecializationInfo *MemberInfo = D->getMemberSpecializationInfo()) {
446     Record.AddDeclRef(MemberInfo->getInstantiatedFrom());
447     Record.push_back(MemberInfo->getTemplateSpecializationKind());
448     Record.AddSourceLocation(MemberInfo->getPointOfInstantiation());
449   } else {
450     Record.AddDeclRef(nullptr);
451   }
452 
453   if (D->getDeclContext() == D->getLexicalDeclContext() &&
454       !D->hasAttrs() &&
455       !D->isImplicit() &&
456       !D->isUsed(false) &&
457       !D->hasExtInfo() &&
458       !D->getTypedefNameForAnonDecl() &&
459       D->getFirstDecl() == D->getMostRecentDecl() &&
460       !D->isInvalidDecl() &&
461       !D->isReferenced() &&
462       !D->isTopLevelDeclInObjCContainer() &&
463       D->getAccess() == AS_none &&
464       !D->isModulePrivate() &&
465       !CXXRecordDecl::classofKind(D->getKind()) &&
466       !D->getIntegerTypeSourceInfo() &&
467       !D->getMemberSpecializationInfo() &&
468       !needsAnonymousDeclarationNumber(D) &&
469       D->getDeclName().getNameKind() == DeclarationName::Identifier)
470     AbbrevToUse = Writer.getDeclEnumAbbrev();
471 
472   Code = serialization::DECL_ENUM;
473 }
474 
475 void ASTDeclWriter::VisitRecordDecl(RecordDecl *D) {
476   VisitTagDecl(D);
477   Record.push_back(D->hasFlexibleArrayMember());
478   Record.push_back(D->isAnonymousStructOrUnion());
479   Record.push_back(D->hasObjectMember());
480   Record.push_back(D->hasVolatileMember());
481   Record.push_back(D->isNonTrivialToPrimitiveDefaultInitialize());
482   Record.push_back(D->isNonTrivialToPrimitiveCopy());
483   Record.push_back(D->isNonTrivialToPrimitiveDestroy());
484   Record.push_back(D->hasNonTrivialToPrimitiveDefaultInitializeCUnion());
485   Record.push_back(D->hasNonTrivialToPrimitiveDestructCUnion());
486   Record.push_back(D->hasNonTrivialToPrimitiveCopyCUnion());
487   Record.push_back(D->isParamDestroyedInCallee());
488   Record.push_back(D->getArgPassingRestrictions());
489 
490   if (D->getDeclContext() == D->getLexicalDeclContext() &&
491       !D->hasAttrs() &&
492       !D->isImplicit() &&
493       !D->isUsed(false) &&
494       !D->hasExtInfo() &&
495       !D->getTypedefNameForAnonDecl() &&
496       D->getFirstDecl() == D->getMostRecentDecl() &&
497       !D->isInvalidDecl() &&
498       !D->isReferenced() &&
499       !D->isTopLevelDeclInObjCContainer() &&
500       D->getAccess() == AS_none &&
501       !D->isModulePrivate() &&
502       !CXXRecordDecl::classofKind(D->getKind()) &&
503       !needsAnonymousDeclarationNumber(D) &&
504       D->getDeclName().getNameKind() == DeclarationName::Identifier)
505     AbbrevToUse = Writer.getDeclRecordAbbrev();
506 
507   Code = serialization::DECL_RECORD;
508 }
509 
510 void ASTDeclWriter::VisitValueDecl(ValueDecl *D) {
511   VisitNamedDecl(D);
512   Record.AddTypeRef(D->getType());
513 }
514 
515 void ASTDeclWriter::VisitEnumConstantDecl(EnumConstantDecl *D) {
516   VisitValueDecl(D);
517   Record.push_back(D->getInitExpr()? 1 : 0);
518   if (D->getInitExpr())
519     Record.AddStmt(D->getInitExpr());
520   Record.AddAPSInt(D->getInitVal());
521 
522   Code = serialization::DECL_ENUM_CONSTANT;
523 }
524 
525 void ASTDeclWriter::VisitDeclaratorDecl(DeclaratorDecl *D) {
526   VisitValueDecl(D);
527   Record.AddSourceLocation(D->getInnerLocStart());
528   Record.push_back(D->hasExtInfo());
529   if (D->hasExtInfo()) {
530     DeclaratorDecl::ExtInfo *Info = D->getExtInfo();
531     Record.AddQualifierInfo(*Info);
532     Record.AddStmt(Info->TrailingRequiresClause);
533   }
534   // The location information is deferred until the end of the record.
535   Record.AddTypeRef(D->getTypeSourceInfo() ? D->getTypeSourceInfo()->getType()
536                                            : QualType());
537 }
538 
539 void ASTDeclWriter::VisitFunctionDecl(FunctionDecl *D) {
540   VisitRedeclarable(D);
541   VisitDeclaratorDecl(D);
542   Record.AddDeclarationNameLoc(D->DNLoc, D->getDeclName());
543   Record.push_back(D->getIdentifierNamespace());
544 
545   // FunctionDecl's body is handled last at ASTWriterDecl::Visit,
546   // after everything else is written.
547   Record.push_back(static_cast<int>(D->getStorageClass())); // FIXME: stable encoding
548   Record.push_back(D->isInlineSpecified());
549   Record.push_back(D->isInlined());
550   Record.push_back(D->isVirtualAsWritten());
551   Record.push_back(D->isPure());
552   Record.push_back(D->hasInheritedPrototype());
553   Record.push_back(D->hasWrittenPrototype());
554   Record.push_back(D->isDeletedBit());
555   Record.push_back(D->isTrivial());
556   Record.push_back(D->isTrivialForCall());
557   Record.push_back(D->isDefaulted());
558   Record.push_back(D->isExplicitlyDefaulted());
559   Record.push_back(D->hasImplicitReturnZero());
560   Record.push_back(D->getConstexprKind());
561   Record.push_back(D->usesSEHTry());
562   Record.push_back(D->hasSkippedBody());
563   Record.push_back(D->isMultiVersion());
564   Record.push_back(D->isLateTemplateParsed());
565   Record.push_back(D->getLinkageInternal());
566   Record.AddSourceLocation(D->getEndLoc());
567 
568   Record.push_back(D->getODRHash());
569   Record.push_back(D->usesFPIntrin());
570 
571   if (D->isDefaulted()) {
572     if (auto *FDI = D->getDefaultedFunctionInfo()) {
573       Record.push_back(FDI->getUnqualifiedLookups().size());
574       for (DeclAccessPair P : FDI->getUnqualifiedLookups()) {
575         Record.AddDeclRef(P.getDecl());
576         Record.push_back(P.getAccess());
577       }
578     } else {
579       Record.push_back(0);
580     }
581   }
582 
583   Record.push_back(D->getTemplatedKind());
584   switch (D->getTemplatedKind()) {
585   case FunctionDecl::TK_NonTemplate:
586     break;
587   case FunctionDecl::TK_FunctionTemplate:
588     Record.AddDeclRef(D->getDescribedFunctionTemplate());
589     break;
590   case FunctionDecl::TK_MemberSpecialization: {
591     MemberSpecializationInfo *MemberInfo = D->getMemberSpecializationInfo();
592     Record.AddDeclRef(MemberInfo->getInstantiatedFrom());
593     Record.push_back(MemberInfo->getTemplateSpecializationKind());
594     Record.AddSourceLocation(MemberInfo->getPointOfInstantiation());
595     break;
596   }
597   case FunctionDecl::TK_FunctionTemplateSpecialization: {
598     FunctionTemplateSpecializationInfo *
599       FTSInfo = D->getTemplateSpecializationInfo();
600 
601     RegisterTemplateSpecialization(FTSInfo->getTemplate(), D);
602 
603     Record.AddDeclRef(FTSInfo->getTemplate());
604     Record.push_back(FTSInfo->getTemplateSpecializationKind());
605 
606     // Template arguments.
607     Record.AddTemplateArgumentList(FTSInfo->TemplateArguments);
608 
609     // Template args as written.
610     Record.push_back(FTSInfo->TemplateArgumentsAsWritten != nullptr);
611     if (FTSInfo->TemplateArgumentsAsWritten) {
612       Record.push_back(FTSInfo->TemplateArgumentsAsWritten->NumTemplateArgs);
613       for (int i=0, e = FTSInfo->TemplateArgumentsAsWritten->NumTemplateArgs;
614              i!=e; ++i)
615         Record.AddTemplateArgumentLoc(
616             (*FTSInfo->TemplateArgumentsAsWritten)[i]);
617       Record.AddSourceLocation(FTSInfo->TemplateArgumentsAsWritten->LAngleLoc);
618       Record.AddSourceLocation(FTSInfo->TemplateArgumentsAsWritten->RAngleLoc);
619     }
620 
621     Record.AddSourceLocation(FTSInfo->getPointOfInstantiation());
622 
623     if (MemberSpecializationInfo *MemberInfo =
624         FTSInfo->getMemberSpecializationInfo()) {
625       Record.push_back(1);
626       Record.AddDeclRef(MemberInfo->getInstantiatedFrom());
627       Record.push_back(MemberInfo->getTemplateSpecializationKind());
628       Record.AddSourceLocation(MemberInfo->getPointOfInstantiation());
629     } else {
630       Record.push_back(0);
631     }
632 
633     if (D->isCanonicalDecl()) {
634       // Write the template that contains the specializations set. We will
635       // add a FunctionTemplateSpecializationInfo to it when reading.
636       Record.AddDeclRef(FTSInfo->getTemplate()->getCanonicalDecl());
637     }
638     break;
639   }
640   case FunctionDecl::TK_DependentFunctionTemplateSpecialization: {
641     DependentFunctionTemplateSpecializationInfo *
642       DFTSInfo = D->getDependentSpecializationInfo();
643 
644     // Templates.
645     Record.push_back(DFTSInfo->getNumTemplates());
646     for (int i=0, e = DFTSInfo->getNumTemplates(); i != e; ++i)
647       Record.AddDeclRef(DFTSInfo->getTemplate(i));
648 
649     // Templates args.
650     Record.push_back(DFTSInfo->getNumTemplateArgs());
651     for (int i=0, e = DFTSInfo->getNumTemplateArgs(); i != e; ++i)
652       Record.AddTemplateArgumentLoc(DFTSInfo->getTemplateArg(i));
653     Record.AddSourceLocation(DFTSInfo->getLAngleLoc());
654     Record.AddSourceLocation(DFTSInfo->getRAngleLoc());
655     break;
656   }
657   }
658 
659   Record.push_back(D->param_size());
660   for (auto P : D->parameters())
661     Record.AddDeclRef(P);
662   Code = serialization::DECL_FUNCTION;
663 }
664 
665 static void addExplicitSpecifier(ExplicitSpecifier ES,
666                                  ASTRecordWriter &Record) {
667   uint64_t Kind = static_cast<uint64_t>(ES.getKind());
668   Kind = Kind << 1 | static_cast<bool>(ES.getExpr());
669   Record.push_back(Kind);
670   if (ES.getExpr()) {
671     Record.AddStmt(ES.getExpr());
672   }
673 }
674 
675 void ASTDeclWriter::VisitCXXDeductionGuideDecl(CXXDeductionGuideDecl *D) {
676   addExplicitSpecifier(D->getExplicitSpecifier(), Record);
677   VisitFunctionDecl(D);
678   Record.push_back(D->isCopyDeductionCandidate());
679   Code = serialization::DECL_CXX_DEDUCTION_GUIDE;
680 }
681 
682 void ASTDeclWriter::VisitObjCMethodDecl(ObjCMethodDecl *D) {
683   VisitNamedDecl(D);
684   // FIXME: convert to LazyStmtPtr?
685   // Unlike C/C++, method bodies will never be in header files.
686   bool HasBodyStuff = D->getBody() != nullptr;
687   Record.push_back(HasBodyStuff);
688   if (HasBodyStuff) {
689     Record.AddStmt(D->getBody());
690   }
691   Record.AddDeclRef(D->getSelfDecl());
692   Record.AddDeclRef(D->getCmdDecl());
693   Record.push_back(D->isInstanceMethod());
694   Record.push_back(D->isVariadic());
695   Record.push_back(D->isPropertyAccessor());
696   Record.push_back(D->isSynthesizedAccessorStub());
697   Record.push_back(D->isDefined());
698   Record.push_back(D->isOverriding());
699   Record.push_back(D->hasSkippedBody());
700 
701   Record.push_back(D->isRedeclaration());
702   Record.push_back(D->hasRedeclaration());
703   if (D->hasRedeclaration()) {
704     assert(Context.getObjCMethodRedeclaration(D));
705     Record.AddDeclRef(Context.getObjCMethodRedeclaration(D));
706   }
707 
708   // FIXME: stable encoding for @required/@optional
709   Record.push_back(D->getImplementationControl());
710   // FIXME: stable encoding for in/out/inout/bycopy/byref/oneway/nullability
711   Record.push_back(D->getObjCDeclQualifier());
712   Record.push_back(D->hasRelatedResultType());
713   Record.AddTypeRef(D->getReturnType());
714   Record.AddTypeSourceInfo(D->getReturnTypeSourceInfo());
715   Record.AddSourceLocation(D->getEndLoc());
716   Record.push_back(D->param_size());
717   for (const auto *P : D->parameters())
718     Record.AddDeclRef(P);
719 
720   Record.push_back(D->getSelLocsKind());
721   unsigned NumStoredSelLocs = D->getNumStoredSelLocs();
722   SourceLocation *SelLocs = D->getStoredSelLocs();
723   Record.push_back(NumStoredSelLocs);
724   for (unsigned i = 0; i != NumStoredSelLocs; ++i)
725     Record.AddSourceLocation(SelLocs[i]);
726 
727   Code = serialization::DECL_OBJC_METHOD;
728 }
729 
730 void ASTDeclWriter::VisitObjCTypeParamDecl(ObjCTypeParamDecl *D) {
731   VisitTypedefNameDecl(D);
732   Record.push_back(D->Variance);
733   Record.push_back(D->Index);
734   Record.AddSourceLocation(D->VarianceLoc);
735   Record.AddSourceLocation(D->ColonLoc);
736 
737   Code = serialization::DECL_OBJC_TYPE_PARAM;
738 }
739 
740 void ASTDeclWriter::VisitObjCContainerDecl(ObjCContainerDecl *D) {
741   VisitNamedDecl(D);
742   Record.AddSourceLocation(D->getAtStartLoc());
743   Record.AddSourceRange(D->getAtEndRange());
744   // Abstract class (no need to define a stable serialization::DECL code).
745 }
746 
747 void ASTDeclWriter::VisitObjCInterfaceDecl(ObjCInterfaceDecl *D) {
748   VisitRedeclarable(D);
749   VisitObjCContainerDecl(D);
750   Record.AddTypeRef(QualType(D->getTypeForDecl(), 0));
751   AddObjCTypeParamList(D->TypeParamList);
752 
753   Record.push_back(D->isThisDeclarationADefinition());
754   if (D->isThisDeclarationADefinition()) {
755     // Write the DefinitionData
756     ObjCInterfaceDecl::DefinitionData &Data = D->data();
757 
758     Record.AddTypeSourceInfo(D->getSuperClassTInfo());
759     Record.AddSourceLocation(D->getEndOfDefinitionLoc());
760     Record.push_back(Data.HasDesignatedInitializers);
761 
762     // Write out the protocols that are directly referenced by the @interface.
763     Record.push_back(Data.ReferencedProtocols.size());
764     for (const auto *P : D->protocols())
765       Record.AddDeclRef(P);
766     for (const auto &PL : D->protocol_locs())
767       Record.AddSourceLocation(PL);
768 
769     // Write out the protocols that are transitively referenced.
770     Record.push_back(Data.AllReferencedProtocols.size());
771     for (ObjCList<ObjCProtocolDecl>::iterator
772               P = Data.AllReferencedProtocols.begin(),
773            PEnd = Data.AllReferencedProtocols.end();
774          P != PEnd; ++P)
775       Record.AddDeclRef(*P);
776 
777 
778     if (ObjCCategoryDecl *Cat = D->getCategoryListRaw()) {
779       // Ensure that we write out the set of categories for this class.
780       Writer.ObjCClassesWithCategories.insert(D);
781 
782       // Make sure that the categories get serialized.
783       for (; Cat; Cat = Cat->getNextClassCategoryRaw())
784         (void)Writer.GetDeclRef(Cat);
785     }
786   }
787 
788   Code = serialization::DECL_OBJC_INTERFACE;
789 }
790 
791 void ASTDeclWriter::VisitObjCIvarDecl(ObjCIvarDecl *D) {
792   VisitFieldDecl(D);
793   // FIXME: stable encoding for @public/@private/@protected/@package
794   Record.push_back(D->getAccessControl());
795   Record.push_back(D->getSynthesize());
796 
797   if (D->getDeclContext() == D->getLexicalDeclContext() &&
798       !D->hasAttrs() &&
799       !D->isImplicit() &&
800       !D->isUsed(false) &&
801       !D->isInvalidDecl() &&
802       !D->isReferenced() &&
803       !D->isModulePrivate() &&
804       !D->getBitWidth() &&
805       !D->hasExtInfo() &&
806       D->getDeclName())
807     AbbrevToUse = Writer.getDeclObjCIvarAbbrev();
808 
809   Code = serialization::DECL_OBJC_IVAR;
810 }
811 
812 void ASTDeclWriter::VisitObjCProtocolDecl(ObjCProtocolDecl *D) {
813   VisitRedeclarable(D);
814   VisitObjCContainerDecl(D);
815 
816   Record.push_back(D->isThisDeclarationADefinition());
817   if (D->isThisDeclarationADefinition()) {
818     Record.push_back(D->protocol_size());
819     for (const auto *I : D->protocols())
820       Record.AddDeclRef(I);
821     for (const auto &PL : D->protocol_locs())
822       Record.AddSourceLocation(PL);
823   }
824 
825   Code = serialization::DECL_OBJC_PROTOCOL;
826 }
827 
828 void ASTDeclWriter::VisitObjCAtDefsFieldDecl(ObjCAtDefsFieldDecl *D) {
829   VisitFieldDecl(D);
830   Code = serialization::DECL_OBJC_AT_DEFS_FIELD;
831 }
832 
833 void ASTDeclWriter::VisitObjCCategoryDecl(ObjCCategoryDecl *D) {
834   VisitObjCContainerDecl(D);
835   Record.AddSourceLocation(D->getCategoryNameLoc());
836   Record.AddSourceLocation(D->getIvarLBraceLoc());
837   Record.AddSourceLocation(D->getIvarRBraceLoc());
838   Record.AddDeclRef(D->getClassInterface());
839   AddObjCTypeParamList(D->TypeParamList);
840   Record.push_back(D->protocol_size());
841   for (const auto *I : D->protocols())
842     Record.AddDeclRef(I);
843   for (const auto &PL : D->protocol_locs())
844     Record.AddSourceLocation(PL);
845   Code = serialization::DECL_OBJC_CATEGORY;
846 }
847 
848 void ASTDeclWriter::VisitObjCCompatibleAliasDecl(ObjCCompatibleAliasDecl *D) {
849   VisitNamedDecl(D);
850   Record.AddDeclRef(D->getClassInterface());
851   Code = serialization::DECL_OBJC_COMPATIBLE_ALIAS;
852 }
853 
854 void ASTDeclWriter::VisitObjCPropertyDecl(ObjCPropertyDecl *D) {
855   VisitNamedDecl(D);
856   Record.AddSourceLocation(D->getAtLoc());
857   Record.AddSourceLocation(D->getLParenLoc());
858   Record.AddTypeRef(D->getType());
859   Record.AddTypeSourceInfo(D->getTypeSourceInfo());
860   // FIXME: stable encoding
861   Record.push_back((unsigned)D->getPropertyAttributes());
862   Record.push_back((unsigned)D->getPropertyAttributesAsWritten());
863   // FIXME: stable encoding
864   Record.push_back((unsigned)D->getPropertyImplementation());
865   Record.AddDeclarationName(D->getGetterName());
866   Record.AddSourceLocation(D->getGetterNameLoc());
867   Record.AddDeclarationName(D->getSetterName());
868   Record.AddSourceLocation(D->getSetterNameLoc());
869   Record.AddDeclRef(D->getGetterMethodDecl());
870   Record.AddDeclRef(D->getSetterMethodDecl());
871   Record.AddDeclRef(D->getPropertyIvarDecl());
872   Code = serialization::DECL_OBJC_PROPERTY;
873 }
874 
875 void ASTDeclWriter::VisitObjCImplDecl(ObjCImplDecl *D) {
876   VisitObjCContainerDecl(D);
877   Record.AddDeclRef(D->getClassInterface());
878   // Abstract class (no need to define a stable serialization::DECL code).
879 }
880 
881 void ASTDeclWriter::VisitObjCCategoryImplDecl(ObjCCategoryImplDecl *D) {
882   VisitObjCImplDecl(D);
883   Record.AddSourceLocation(D->getCategoryNameLoc());
884   Code = serialization::DECL_OBJC_CATEGORY_IMPL;
885 }
886 
887 void ASTDeclWriter::VisitObjCImplementationDecl(ObjCImplementationDecl *D) {
888   VisitObjCImplDecl(D);
889   Record.AddDeclRef(D->getSuperClass());
890   Record.AddSourceLocation(D->getSuperClassLoc());
891   Record.AddSourceLocation(D->getIvarLBraceLoc());
892   Record.AddSourceLocation(D->getIvarRBraceLoc());
893   Record.push_back(D->hasNonZeroConstructors());
894   Record.push_back(D->hasDestructors());
895   Record.push_back(D->NumIvarInitializers);
896   if (D->NumIvarInitializers)
897     Record.AddCXXCtorInitializers(
898         llvm::makeArrayRef(D->init_begin(), D->init_end()));
899   Code = serialization::DECL_OBJC_IMPLEMENTATION;
900 }
901 
902 void ASTDeclWriter::VisitObjCPropertyImplDecl(ObjCPropertyImplDecl *D) {
903   VisitDecl(D);
904   Record.AddSourceLocation(D->getBeginLoc());
905   Record.AddDeclRef(D->getPropertyDecl());
906   Record.AddDeclRef(D->getPropertyIvarDecl());
907   Record.AddSourceLocation(D->getPropertyIvarDeclLoc());
908   Record.AddDeclRef(D->getGetterMethodDecl());
909   Record.AddDeclRef(D->getSetterMethodDecl());
910   Record.AddStmt(D->getGetterCXXConstructor());
911   Record.AddStmt(D->getSetterCXXAssignment());
912   Code = serialization::DECL_OBJC_PROPERTY_IMPL;
913 }
914 
915 void ASTDeclWriter::VisitFieldDecl(FieldDecl *D) {
916   VisitDeclaratorDecl(D);
917   Record.push_back(D->isMutable());
918 
919   FieldDecl::InitStorageKind ISK = D->InitStorage.getInt();
920   Record.push_back(ISK);
921   if (ISK == FieldDecl::ISK_CapturedVLAType)
922     Record.AddTypeRef(QualType(D->getCapturedVLAType(), 0));
923   else if (ISK)
924     Record.AddStmt(D->getInClassInitializer());
925 
926   Record.AddStmt(D->getBitWidth());
927 
928   if (!D->getDeclName())
929     Record.AddDeclRef(Context.getInstantiatedFromUnnamedFieldDecl(D));
930 
931   if (D->getDeclContext() == D->getLexicalDeclContext() &&
932       !D->hasAttrs() &&
933       !D->isImplicit() &&
934       !D->isUsed(false) &&
935       !D->isInvalidDecl() &&
936       !D->isReferenced() &&
937       !D->isTopLevelDeclInObjCContainer() &&
938       !D->isModulePrivate() &&
939       !D->getBitWidth() &&
940       !D->hasInClassInitializer() &&
941       !D->hasCapturedVLAType() &&
942       !D->hasExtInfo() &&
943       !ObjCIvarDecl::classofKind(D->getKind()) &&
944       !ObjCAtDefsFieldDecl::classofKind(D->getKind()) &&
945       D->getDeclName())
946     AbbrevToUse = Writer.getDeclFieldAbbrev();
947 
948   Code = serialization::DECL_FIELD;
949 }
950 
951 void ASTDeclWriter::VisitMSPropertyDecl(MSPropertyDecl *D) {
952   VisitDeclaratorDecl(D);
953   Record.AddIdentifierRef(D->getGetterId());
954   Record.AddIdentifierRef(D->getSetterId());
955   Code = serialization::DECL_MS_PROPERTY;
956 }
957 
958 void ASTDeclWriter::VisitMSGuidDecl(MSGuidDecl *D) {
959   VisitValueDecl(D);
960   MSGuidDecl::Parts Parts = D->getParts();
961   Record.push_back(Parts.Part1);
962   Record.push_back(Parts.Part2);
963   Record.push_back(Parts.Part3);
964   for (auto C : Parts.Part4And5)
965     Record.push_back(C);
966   Code = serialization::DECL_MS_GUID;
967 }
968 
969 void ASTDeclWriter::VisitTemplateParamObjectDecl(TemplateParamObjectDecl *D) {
970   VisitValueDecl(D);
971   Record.AddAPValue(D->getValue());
972   Code = serialization::DECL_TEMPLATE_PARAM_OBJECT;
973 }
974 
975 void ASTDeclWriter::VisitIndirectFieldDecl(IndirectFieldDecl *D) {
976   VisitValueDecl(D);
977   Record.push_back(D->getChainingSize());
978 
979   for (const auto *P : D->chain())
980     Record.AddDeclRef(P);
981   Code = serialization::DECL_INDIRECTFIELD;
982 }
983 
984 void ASTDeclWriter::VisitVarDecl(VarDecl *D) {
985   VisitRedeclarable(D);
986   VisitDeclaratorDecl(D);
987   Record.push_back(D->getStorageClass());
988   Record.push_back(D->getTSCSpec());
989   Record.push_back(D->getInitStyle());
990   Record.push_back(D->isARCPseudoStrong());
991   if (!isa<ParmVarDecl>(D)) {
992     Record.push_back(D->isThisDeclarationADemotedDefinition());
993     Record.push_back(D->isExceptionVariable());
994     Record.push_back(D->isNRVOVariable());
995     Record.push_back(D->isCXXForRangeDecl());
996     Record.push_back(D->isObjCForDecl());
997     Record.push_back(D->isInline());
998     Record.push_back(D->isInlineSpecified());
999     Record.push_back(D->isConstexpr());
1000     Record.push_back(D->isInitCapture());
1001     Record.push_back(D->isPreviousDeclInSameBlockScope());
1002     if (const auto *IPD = dyn_cast<ImplicitParamDecl>(D))
1003       Record.push_back(static_cast<unsigned>(IPD->getParameterKind()));
1004     else
1005       Record.push_back(0);
1006     Record.push_back(D->isEscapingByref());
1007   }
1008   Record.push_back(D->getLinkageInternal());
1009 
1010   Record.AddVarDeclInit(D);
1011 
1012   if (D->hasAttr<BlocksAttr>() && D->getType()->getAsCXXRecordDecl()) {
1013     BlockVarCopyInit Init = Writer.Context->getBlockVarCopyInit(D);
1014     Record.AddStmt(Init.getCopyExpr());
1015     if (Init.getCopyExpr())
1016       Record.push_back(Init.canThrow());
1017   }
1018 
1019   if (D->getStorageDuration() == SD_Static) {
1020     bool ModulesCodegen = false;
1021     if (Writer.WritingModule &&
1022         !D->getDescribedVarTemplate() && !D->getMemberSpecializationInfo() &&
1023         !isa<VarTemplateSpecializationDecl>(D)) {
1024       // When building a C++ Modules TS module interface unit, a strong
1025       // definition in the module interface is provided by the compilation of
1026       // that module interface unit, not by its users. (Inline variables are
1027       // still emitted in module users.)
1028       ModulesCodegen =
1029           (Writer.WritingModule->Kind == Module::ModuleInterfaceUnit ||
1030            (D->hasAttr<DLLExportAttr>() &&
1031             Writer.Context->getLangOpts().BuildingPCHWithObjectFile)) &&
1032           Writer.Context->GetGVALinkageForVariable(D) == GVA_StrongExternal;
1033     }
1034     Record.push_back(ModulesCodegen);
1035     if (ModulesCodegen)
1036       Writer.ModularCodegenDecls.push_back(Writer.GetDeclRef(D));
1037   }
1038 
1039   enum {
1040     VarNotTemplate = 0, VarTemplate, StaticDataMemberSpecialization
1041   };
1042   if (VarTemplateDecl *TemplD = D->getDescribedVarTemplate()) {
1043     Record.push_back(VarTemplate);
1044     Record.AddDeclRef(TemplD);
1045   } else if (MemberSpecializationInfo *SpecInfo
1046                = D->getMemberSpecializationInfo()) {
1047     Record.push_back(StaticDataMemberSpecialization);
1048     Record.AddDeclRef(SpecInfo->getInstantiatedFrom());
1049     Record.push_back(SpecInfo->getTemplateSpecializationKind());
1050     Record.AddSourceLocation(SpecInfo->getPointOfInstantiation());
1051   } else {
1052     Record.push_back(VarNotTemplate);
1053   }
1054 
1055   if (D->getDeclContext() == D->getLexicalDeclContext() &&
1056       !D->hasAttrs() &&
1057       !D->isImplicit() &&
1058       !D->isUsed(false) &&
1059       !D->isInvalidDecl() &&
1060       !D->isReferenced() &&
1061       !D->isTopLevelDeclInObjCContainer() &&
1062       D->getAccess() == AS_none &&
1063       !D->isModulePrivate() &&
1064       !needsAnonymousDeclarationNumber(D) &&
1065       D->getDeclName().getNameKind() == DeclarationName::Identifier &&
1066       !D->hasExtInfo() &&
1067       D->getFirstDecl() == D->getMostRecentDecl() &&
1068       D->getKind() == Decl::Var &&
1069       !D->isInline() &&
1070       !D->isConstexpr() &&
1071       !D->isInitCapture() &&
1072       !D->isPreviousDeclInSameBlockScope() &&
1073       !(D->hasAttr<BlocksAttr>() && D->getType()->getAsCXXRecordDecl()) &&
1074       !D->isEscapingByref() &&
1075       D->getStorageDuration() != SD_Static &&
1076       !D->getMemberSpecializationInfo())
1077     AbbrevToUse = Writer.getDeclVarAbbrev();
1078 
1079   Code = serialization::DECL_VAR;
1080 }
1081 
1082 void ASTDeclWriter::VisitImplicitParamDecl(ImplicitParamDecl *D) {
1083   VisitVarDecl(D);
1084   Code = serialization::DECL_IMPLICIT_PARAM;
1085 }
1086 
1087 void ASTDeclWriter::VisitParmVarDecl(ParmVarDecl *D) {
1088   VisitVarDecl(D);
1089   Record.push_back(D->isObjCMethodParameter());
1090   Record.push_back(D->getFunctionScopeDepth());
1091   Record.push_back(D->getFunctionScopeIndex());
1092   Record.push_back(D->getObjCDeclQualifier()); // FIXME: stable encoding
1093   Record.push_back(D->isKNRPromoted());
1094   Record.push_back(D->hasInheritedDefaultArg());
1095   Record.push_back(D->hasUninstantiatedDefaultArg());
1096   if (D->hasUninstantiatedDefaultArg())
1097     Record.AddStmt(D->getUninstantiatedDefaultArg());
1098   Code = serialization::DECL_PARM_VAR;
1099 
1100   // If the assumptions about the DECL_PARM_VAR abbrev are true, use it.  Here
1101   // we dynamically check for the properties that we optimize for, but don't
1102   // know are true of all PARM_VAR_DECLs.
1103   if (D->getDeclContext() == D->getLexicalDeclContext() &&
1104       !D->hasAttrs() &&
1105       !D->hasExtInfo() &&
1106       !D->isImplicit() &&
1107       !D->isUsed(false) &&
1108       !D->isInvalidDecl() &&
1109       !D->isReferenced() &&
1110       D->getAccess() == AS_none &&
1111       !D->isModulePrivate() &&
1112       D->getStorageClass() == 0 &&
1113       D->getInitStyle() == VarDecl::CInit && // Can params have anything else?
1114       D->getFunctionScopeDepth() == 0 &&
1115       D->getObjCDeclQualifier() == 0 &&
1116       !D->isKNRPromoted() &&
1117       !D->hasInheritedDefaultArg() &&
1118       D->getInit() == nullptr &&
1119       !D->hasUninstantiatedDefaultArg())  // No default expr.
1120     AbbrevToUse = Writer.getDeclParmVarAbbrev();
1121 
1122   // Check things we know are true of *every* PARM_VAR_DECL, which is more than
1123   // just us assuming it.
1124   assert(!D->getTSCSpec() && "PARM_VAR_DECL can't use TLS");
1125   assert(!D->isThisDeclarationADemotedDefinition()
1126          && "PARM_VAR_DECL can't be demoted definition.");
1127   assert(D->getAccess() == AS_none && "PARM_VAR_DECL can't be public/private");
1128   assert(!D->isExceptionVariable() && "PARM_VAR_DECL can't be exception var");
1129   assert(D->getPreviousDecl() == nullptr && "PARM_VAR_DECL can't be redecl");
1130   assert(!D->isStaticDataMember() &&
1131          "PARM_VAR_DECL can't be static data member");
1132 }
1133 
1134 void ASTDeclWriter::VisitDecompositionDecl(DecompositionDecl *D) {
1135   // Record the number of bindings first to simplify deserialization.
1136   Record.push_back(D->bindings().size());
1137 
1138   VisitVarDecl(D);
1139   for (auto *B : D->bindings())
1140     Record.AddDeclRef(B);
1141   Code = serialization::DECL_DECOMPOSITION;
1142 }
1143 
1144 void ASTDeclWriter::VisitBindingDecl(BindingDecl *D) {
1145   VisitValueDecl(D);
1146   Record.AddStmt(D->getBinding());
1147   Code = serialization::DECL_BINDING;
1148 }
1149 
1150 void ASTDeclWriter::VisitFileScopeAsmDecl(FileScopeAsmDecl *D) {
1151   VisitDecl(D);
1152   Record.AddStmt(D->getAsmString());
1153   Record.AddSourceLocation(D->getRParenLoc());
1154   Code = serialization::DECL_FILE_SCOPE_ASM;
1155 }
1156 
1157 void ASTDeclWriter::VisitEmptyDecl(EmptyDecl *D) {
1158   VisitDecl(D);
1159   Code = serialization::DECL_EMPTY;
1160 }
1161 
1162 void ASTDeclWriter::VisitLifetimeExtendedTemporaryDecl(
1163     LifetimeExtendedTemporaryDecl *D) {
1164   VisitDecl(D);
1165   Record.AddDeclRef(D->getExtendingDecl());
1166   Record.AddStmt(D->getTemporaryExpr());
1167   Record.push_back(static_cast<bool>(D->getValue()));
1168   if (D->getValue())
1169     Record.AddAPValue(*D->getValue());
1170   Record.push_back(D->getManglingNumber());
1171   Code = serialization::DECL_LIFETIME_EXTENDED_TEMPORARY;
1172 }
1173 void ASTDeclWriter::VisitBlockDecl(BlockDecl *D) {
1174   VisitDecl(D);
1175   Record.AddStmt(D->getBody());
1176   Record.AddTypeSourceInfo(D->getSignatureAsWritten());
1177   Record.push_back(D->param_size());
1178   for (ParmVarDecl *P : D->parameters())
1179     Record.AddDeclRef(P);
1180   Record.push_back(D->isVariadic());
1181   Record.push_back(D->blockMissingReturnType());
1182   Record.push_back(D->isConversionFromLambda());
1183   Record.push_back(D->doesNotEscape());
1184   Record.push_back(D->canAvoidCopyToHeap());
1185   Record.push_back(D->capturesCXXThis());
1186   Record.push_back(D->getNumCaptures());
1187   for (const auto &capture : D->captures()) {
1188     Record.AddDeclRef(capture.getVariable());
1189 
1190     unsigned flags = 0;
1191     if (capture.isByRef()) flags |= 1;
1192     if (capture.isNested()) flags |= 2;
1193     if (capture.hasCopyExpr()) flags |= 4;
1194     Record.push_back(flags);
1195 
1196     if (capture.hasCopyExpr()) Record.AddStmt(capture.getCopyExpr());
1197   }
1198 
1199   Code = serialization::DECL_BLOCK;
1200 }
1201 
1202 void ASTDeclWriter::VisitCapturedDecl(CapturedDecl *CD) {
1203   Record.push_back(CD->getNumParams());
1204   VisitDecl(CD);
1205   Record.push_back(CD->getContextParamPosition());
1206   Record.push_back(CD->isNothrow() ? 1 : 0);
1207   // Body is stored by VisitCapturedStmt.
1208   for (unsigned I = 0; I < CD->getNumParams(); ++I)
1209     Record.AddDeclRef(CD->getParam(I));
1210   Code = serialization::DECL_CAPTURED;
1211 }
1212 
1213 void ASTDeclWriter::VisitLinkageSpecDecl(LinkageSpecDecl *D) {
1214   VisitDecl(D);
1215   Record.push_back(D->getLanguage());
1216   Record.AddSourceLocation(D->getExternLoc());
1217   Record.AddSourceLocation(D->getRBraceLoc());
1218   Code = serialization::DECL_LINKAGE_SPEC;
1219 }
1220 
1221 void ASTDeclWriter::VisitExportDecl(ExportDecl *D) {
1222   VisitDecl(D);
1223   Record.AddSourceLocation(D->getRBraceLoc());
1224   Code = serialization::DECL_EXPORT;
1225 }
1226 
1227 void ASTDeclWriter::VisitLabelDecl(LabelDecl *D) {
1228   VisitNamedDecl(D);
1229   Record.AddSourceLocation(D->getBeginLoc());
1230   Code = serialization::DECL_LABEL;
1231 }
1232 
1233 
1234 void ASTDeclWriter::VisitNamespaceDecl(NamespaceDecl *D) {
1235   VisitRedeclarable(D);
1236   VisitNamedDecl(D);
1237   Record.push_back(D->isInline());
1238   Record.AddSourceLocation(D->getBeginLoc());
1239   Record.AddSourceLocation(D->getRBraceLoc());
1240 
1241   if (D->isOriginalNamespace())
1242     Record.AddDeclRef(D->getAnonymousNamespace());
1243   Code = serialization::DECL_NAMESPACE;
1244 
1245   if (Writer.hasChain() && D->isAnonymousNamespace() &&
1246       D == D->getMostRecentDecl()) {
1247     // This is a most recent reopening of the anonymous namespace. If its parent
1248     // is in a previous PCH (or is the TU), mark that parent for update, because
1249     // the original namespace always points to the latest re-opening of its
1250     // anonymous namespace.
1251     Decl *Parent = cast<Decl>(
1252         D->getParent()->getRedeclContext()->getPrimaryContext());
1253     if (Parent->isFromASTFile() || isa<TranslationUnitDecl>(Parent)) {
1254       Writer.DeclUpdates[Parent].push_back(
1255           ASTWriter::DeclUpdate(UPD_CXX_ADDED_ANONYMOUS_NAMESPACE, D));
1256     }
1257   }
1258 }
1259 
1260 void ASTDeclWriter::VisitNamespaceAliasDecl(NamespaceAliasDecl *D) {
1261   VisitRedeclarable(D);
1262   VisitNamedDecl(D);
1263   Record.AddSourceLocation(D->getNamespaceLoc());
1264   Record.AddSourceLocation(D->getTargetNameLoc());
1265   Record.AddNestedNameSpecifierLoc(D->getQualifierLoc());
1266   Record.AddDeclRef(D->getNamespace());
1267   Code = serialization::DECL_NAMESPACE_ALIAS;
1268 }
1269 
1270 void ASTDeclWriter::VisitUsingDecl(UsingDecl *D) {
1271   VisitNamedDecl(D);
1272   Record.AddSourceLocation(D->getUsingLoc());
1273   Record.AddNestedNameSpecifierLoc(D->getQualifierLoc());
1274   Record.AddDeclarationNameLoc(D->DNLoc, D->getDeclName());
1275   Record.AddDeclRef(D->FirstUsingShadow.getPointer());
1276   Record.push_back(D->hasTypename());
1277   Record.AddDeclRef(Context.getInstantiatedFromUsingDecl(D));
1278   Code = serialization::DECL_USING;
1279 }
1280 
1281 void ASTDeclWriter::VisitUsingPackDecl(UsingPackDecl *D) {
1282   Record.push_back(D->NumExpansions);
1283   VisitNamedDecl(D);
1284   Record.AddDeclRef(D->getInstantiatedFromUsingDecl());
1285   for (auto *E : D->expansions())
1286     Record.AddDeclRef(E);
1287   Code = serialization::DECL_USING_PACK;
1288 }
1289 
1290 void ASTDeclWriter::VisitUsingShadowDecl(UsingShadowDecl *D) {
1291   VisitRedeclarable(D);
1292   VisitNamedDecl(D);
1293   Record.AddDeclRef(D->getTargetDecl());
1294   Record.push_back(D->getIdentifierNamespace());
1295   Record.AddDeclRef(D->UsingOrNextShadow);
1296   Record.AddDeclRef(Context.getInstantiatedFromUsingShadowDecl(D));
1297   Code = serialization::DECL_USING_SHADOW;
1298 }
1299 
1300 void ASTDeclWriter::VisitConstructorUsingShadowDecl(
1301     ConstructorUsingShadowDecl *D) {
1302   VisitUsingShadowDecl(D);
1303   Record.AddDeclRef(D->NominatedBaseClassShadowDecl);
1304   Record.AddDeclRef(D->ConstructedBaseClassShadowDecl);
1305   Record.push_back(D->IsVirtual);
1306   Code = serialization::DECL_CONSTRUCTOR_USING_SHADOW;
1307 }
1308 
1309 void ASTDeclWriter::VisitUsingDirectiveDecl(UsingDirectiveDecl *D) {
1310   VisitNamedDecl(D);
1311   Record.AddSourceLocation(D->getUsingLoc());
1312   Record.AddSourceLocation(D->getNamespaceKeyLocation());
1313   Record.AddNestedNameSpecifierLoc(D->getQualifierLoc());
1314   Record.AddDeclRef(D->getNominatedNamespace());
1315   Record.AddDeclRef(dyn_cast<Decl>(D->getCommonAncestor()));
1316   Code = serialization::DECL_USING_DIRECTIVE;
1317 }
1318 
1319 void ASTDeclWriter::VisitUnresolvedUsingValueDecl(UnresolvedUsingValueDecl *D) {
1320   VisitValueDecl(D);
1321   Record.AddSourceLocation(D->getUsingLoc());
1322   Record.AddNestedNameSpecifierLoc(D->getQualifierLoc());
1323   Record.AddDeclarationNameLoc(D->DNLoc, D->getDeclName());
1324   Record.AddSourceLocation(D->getEllipsisLoc());
1325   Code = serialization::DECL_UNRESOLVED_USING_VALUE;
1326 }
1327 
1328 void ASTDeclWriter::VisitUnresolvedUsingTypenameDecl(
1329                                                UnresolvedUsingTypenameDecl *D) {
1330   VisitTypeDecl(D);
1331   Record.AddSourceLocation(D->getTypenameLoc());
1332   Record.AddNestedNameSpecifierLoc(D->getQualifierLoc());
1333   Record.AddSourceLocation(D->getEllipsisLoc());
1334   Code = serialization::DECL_UNRESOLVED_USING_TYPENAME;
1335 }
1336 
1337 void ASTDeclWriter::VisitCXXRecordDecl(CXXRecordDecl *D) {
1338   VisitRecordDecl(D);
1339 
1340   enum {
1341     CXXRecNotTemplate = 0, CXXRecTemplate, CXXRecMemberSpecialization
1342   };
1343   if (ClassTemplateDecl *TemplD = D->getDescribedClassTemplate()) {
1344     Record.push_back(CXXRecTemplate);
1345     Record.AddDeclRef(TemplD);
1346   } else if (MemberSpecializationInfo *MSInfo
1347                = D->getMemberSpecializationInfo()) {
1348     Record.push_back(CXXRecMemberSpecialization);
1349     Record.AddDeclRef(MSInfo->getInstantiatedFrom());
1350     Record.push_back(MSInfo->getTemplateSpecializationKind());
1351     Record.AddSourceLocation(MSInfo->getPointOfInstantiation());
1352   } else {
1353     Record.push_back(CXXRecNotTemplate);
1354   }
1355 
1356   Record.push_back(D->isThisDeclarationADefinition());
1357   if (D->isThisDeclarationADefinition())
1358     Record.AddCXXDefinitionData(D);
1359 
1360   // Store (what we currently believe to be) the key function to avoid
1361   // deserializing every method so we can compute it.
1362   if (D->isCompleteDefinition())
1363     Record.AddDeclRef(Context.getCurrentKeyFunction(D));
1364 
1365   Code = serialization::DECL_CXX_RECORD;
1366 }
1367 
1368 void ASTDeclWriter::VisitCXXMethodDecl(CXXMethodDecl *D) {
1369   VisitFunctionDecl(D);
1370   if (D->isCanonicalDecl()) {
1371     Record.push_back(D->size_overridden_methods());
1372     for (const CXXMethodDecl *MD : D->overridden_methods())
1373       Record.AddDeclRef(MD);
1374   } else {
1375     // We only need to record overridden methods once for the canonical decl.
1376     Record.push_back(0);
1377   }
1378 
1379   if (D->getDeclContext() == D->getLexicalDeclContext() &&
1380       D->getFirstDecl() == D->getMostRecentDecl() &&
1381       !D->isInvalidDecl() &&
1382       !D->hasAttrs() &&
1383       !D->isTopLevelDeclInObjCContainer() &&
1384       D->getDeclName().getNameKind() == DeclarationName::Identifier &&
1385       !D->hasExtInfo() &&
1386       !D->hasInheritedPrototype() &&
1387       D->hasWrittenPrototype())
1388     AbbrevToUse = Writer.getDeclCXXMethodAbbrev();
1389 
1390   Code = serialization::DECL_CXX_METHOD;
1391 }
1392 
1393 void ASTDeclWriter::VisitCXXConstructorDecl(CXXConstructorDecl *D) {
1394   Record.push_back(D->getTraillingAllocKind());
1395   addExplicitSpecifier(D->getExplicitSpecifier(), Record);
1396   if (auto Inherited = D->getInheritedConstructor()) {
1397     Record.AddDeclRef(Inherited.getShadowDecl());
1398     Record.AddDeclRef(Inherited.getConstructor());
1399   }
1400 
1401   VisitCXXMethodDecl(D);
1402   Code = serialization::DECL_CXX_CONSTRUCTOR;
1403 }
1404 
1405 void ASTDeclWriter::VisitCXXDestructorDecl(CXXDestructorDecl *D) {
1406   VisitCXXMethodDecl(D);
1407 
1408   Record.AddDeclRef(D->getOperatorDelete());
1409   if (D->getOperatorDelete())
1410     Record.AddStmt(D->getOperatorDeleteThisArg());
1411 
1412   Code = serialization::DECL_CXX_DESTRUCTOR;
1413 }
1414 
1415 void ASTDeclWriter::VisitCXXConversionDecl(CXXConversionDecl *D) {
1416   addExplicitSpecifier(D->getExplicitSpecifier(), Record);
1417   VisitCXXMethodDecl(D);
1418   Code = serialization::DECL_CXX_CONVERSION;
1419 }
1420 
1421 void ASTDeclWriter::VisitImportDecl(ImportDecl *D) {
1422   VisitDecl(D);
1423   Record.push_back(Writer.getSubmoduleID(D->getImportedModule()));
1424   ArrayRef<SourceLocation> IdentifierLocs = D->getIdentifierLocs();
1425   Record.push_back(!IdentifierLocs.empty());
1426   if (IdentifierLocs.empty()) {
1427     Record.AddSourceLocation(D->getEndLoc());
1428     Record.push_back(1);
1429   } else {
1430     for (unsigned I = 0, N = IdentifierLocs.size(); I != N; ++I)
1431       Record.AddSourceLocation(IdentifierLocs[I]);
1432     Record.push_back(IdentifierLocs.size());
1433   }
1434   // Note: the number of source locations must always be the last element in
1435   // the record.
1436   Code = serialization::DECL_IMPORT;
1437 }
1438 
1439 void ASTDeclWriter::VisitAccessSpecDecl(AccessSpecDecl *D) {
1440   VisitDecl(D);
1441   Record.AddSourceLocation(D->getColonLoc());
1442   Code = serialization::DECL_ACCESS_SPEC;
1443 }
1444 
1445 void ASTDeclWriter::VisitFriendDecl(FriendDecl *D) {
1446   // Record the number of friend type template parameter lists here
1447   // so as to simplify memory allocation during deserialization.
1448   Record.push_back(D->NumTPLists);
1449   VisitDecl(D);
1450   bool hasFriendDecl = D->Friend.is<NamedDecl*>();
1451   Record.push_back(hasFriendDecl);
1452   if (hasFriendDecl)
1453     Record.AddDeclRef(D->getFriendDecl());
1454   else
1455     Record.AddTypeSourceInfo(D->getFriendType());
1456   for (unsigned i = 0; i < D->NumTPLists; ++i)
1457     Record.AddTemplateParameterList(D->getFriendTypeTemplateParameterList(i));
1458   Record.AddDeclRef(D->getNextFriend());
1459   Record.push_back(D->UnsupportedFriend);
1460   Record.AddSourceLocation(D->FriendLoc);
1461   Code = serialization::DECL_FRIEND;
1462 }
1463 
1464 void ASTDeclWriter::VisitFriendTemplateDecl(FriendTemplateDecl *D) {
1465   VisitDecl(D);
1466   Record.push_back(D->getNumTemplateParameters());
1467   for (unsigned i = 0, e = D->getNumTemplateParameters(); i != e; ++i)
1468     Record.AddTemplateParameterList(D->getTemplateParameterList(i));
1469   Record.push_back(D->getFriendDecl() != nullptr);
1470   if (D->getFriendDecl())
1471     Record.AddDeclRef(D->getFriendDecl());
1472   else
1473     Record.AddTypeSourceInfo(D->getFriendType());
1474   Record.AddSourceLocation(D->getFriendLoc());
1475   Code = serialization::DECL_FRIEND_TEMPLATE;
1476 }
1477 
1478 void ASTDeclWriter::VisitTemplateDecl(TemplateDecl *D) {
1479   VisitNamedDecl(D);
1480 
1481   Record.AddDeclRef(D->getTemplatedDecl());
1482   Record.AddTemplateParameterList(D->getTemplateParameters());
1483 }
1484 
1485 void ASTDeclWriter::VisitConceptDecl(ConceptDecl *D) {
1486   VisitTemplateDecl(D);
1487   Record.AddStmt(D->getConstraintExpr());
1488   Code = serialization::DECL_CONCEPT;
1489 }
1490 
1491 void ASTDeclWriter::VisitRequiresExprBodyDecl(RequiresExprBodyDecl *D) {
1492   Code = serialization::DECL_REQUIRES_EXPR_BODY;
1493 }
1494 
1495 void ASTDeclWriter::VisitRedeclarableTemplateDecl(RedeclarableTemplateDecl *D) {
1496   VisitRedeclarable(D);
1497 
1498   // Emit data to initialize CommonOrPrev before VisitTemplateDecl so that
1499   // getCommonPtr() can be used while this is still initializing.
1500   if (D->isFirstDecl()) {
1501     // This declaration owns the 'common' pointer, so serialize that data now.
1502     Record.AddDeclRef(D->getInstantiatedFromMemberTemplate());
1503     if (D->getInstantiatedFromMemberTemplate())
1504       Record.push_back(D->isMemberSpecialization());
1505   }
1506 
1507   VisitTemplateDecl(D);
1508   Record.push_back(D->getIdentifierNamespace());
1509 }
1510 
1511 void ASTDeclWriter::VisitClassTemplateDecl(ClassTemplateDecl *D) {
1512   VisitRedeclarableTemplateDecl(D);
1513 
1514   if (D->isFirstDecl())
1515     AddTemplateSpecializations(D);
1516   Code = serialization::DECL_CLASS_TEMPLATE;
1517 }
1518 
1519 void ASTDeclWriter::VisitClassTemplateSpecializationDecl(
1520                                            ClassTemplateSpecializationDecl *D) {
1521   RegisterTemplateSpecialization(D->getSpecializedTemplate(), D);
1522 
1523   VisitCXXRecordDecl(D);
1524 
1525   llvm::PointerUnion<ClassTemplateDecl *,
1526                      ClassTemplatePartialSpecializationDecl *> InstFrom
1527     = D->getSpecializedTemplateOrPartial();
1528   if (Decl *InstFromD = InstFrom.dyn_cast<ClassTemplateDecl *>()) {
1529     Record.AddDeclRef(InstFromD);
1530   } else {
1531     Record.AddDeclRef(InstFrom.get<ClassTemplatePartialSpecializationDecl *>());
1532     Record.AddTemplateArgumentList(&D->getTemplateInstantiationArgs());
1533   }
1534 
1535   Record.AddTemplateArgumentList(&D->getTemplateArgs());
1536   Record.AddSourceLocation(D->getPointOfInstantiation());
1537   Record.push_back(D->getSpecializationKind());
1538   Record.push_back(D->isCanonicalDecl());
1539 
1540   if (D->isCanonicalDecl()) {
1541     // When reading, we'll add it to the folding set of the following template.
1542     Record.AddDeclRef(D->getSpecializedTemplate()->getCanonicalDecl());
1543   }
1544 
1545   // Explicit info.
1546   Record.AddTypeSourceInfo(D->getTypeAsWritten());
1547   if (D->getTypeAsWritten()) {
1548     Record.AddSourceLocation(D->getExternLoc());
1549     Record.AddSourceLocation(D->getTemplateKeywordLoc());
1550   }
1551 
1552   Code = serialization::DECL_CLASS_TEMPLATE_SPECIALIZATION;
1553 }
1554 
1555 void ASTDeclWriter::VisitClassTemplatePartialSpecializationDecl(
1556                                     ClassTemplatePartialSpecializationDecl *D) {
1557   Record.AddTemplateParameterList(D->getTemplateParameters());
1558   Record.AddASTTemplateArgumentListInfo(D->getTemplateArgsAsWritten());
1559 
1560   VisitClassTemplateSpecializationDecl(D);
1561 
1562   // These are read/set from/to the first declaration.
1563   if (D->getPreviousDecl() == nullptr) {
1564     Record.AddDeclRef(D->getInstantiatedFromMember());
1565     Record.push_back(D->isMemberSpecialization());
1566   }
1567 
1568   Code = serialization::DECL_CLASS_TEMPLATE_PARTIAL_SPECIALIZATION;
1569 }
1570 
1571 void ASTDeclWriter::VisitVarTemplateDecl(VarTemplateDecl *D) {
1572   VisitRedeclarableTemplateDecl(D);
1573 
1574   if (D->isFirstDecl())
1575     AddTemplateSpecializations(D);
1576   Code = serialization::DECL_VAR_TEMPLATE;
1577 }
1578 
1579 void ASTDeclWriter::VisitVarTemplateSpecializationDecl(
1580     VarTemplateSpecializationDecl *D) {
1581   RegisterTemplateSpecialization(D->getSpecializedTemplate(), D);
1582 
1583   VisitVarDecl(D);
1584 
1585   llvm::PointerUnion<VarTemplateDecl *, VarTemplatePartialSpecializationDecl *>
1586   InstFrom = D->getSpecializedTemplateOrPartial();
1587   if (Decl *InstFromD = InstFrom.dyn_cast<VarTemplateDecl *>()) {
1588     Record.AddDeclRef(InstFromD);
1589   } else {
1590     Record.AddDeclRef(InstFrom.get<VarTemplatePartialSpecializationDecl *>());
1591     Record.AddTemplateArgumentList(&D->getTemplateInstantiationArgs());
1592   }
1593 
1594   // Explicit info.
1595   Record.AddTypeSourceInfo(D->getTypeAsWritten());
1596   if (D->getTypeAsWritten()) {
1597     Record.AddSourceLocation(D->getExternLoc());
1598     Record.AddSourceLocation(D->getTemplateKeywordLoc());
1599   }
1600 
1601   Record.AddTemplateArgumentList(&D->getTemplateArgs());
1602   Record.AddSourceLocation(D->getPointOfInstantiation());
1603   Record.push_back(D->getSpecializationKind());
1604   Record.push_back(D->IsCompleteDefinition);
1605   Record.push_back(D->isCanonicalDecl());
1606 
1607   if (D->isCanonicalDecl()) {
1608     // When reading, we'll add it to the folding set of the following template.
1609     Record.AddDeclRef(D->getSpecializedTemplate()->getCanonicalDecl());
1610   }
1611 
1612   Code = serialization::DECL_VAR_TEMPLATE_SPECIALIZATION;
1613 }
1614 
1615 void ASTDeclWriter::VisitVarTemplatePartialSpecializationDecl(
1616     VarTemplatePartialSpecializationDecl *D) {
1617   Record.AddTemplateParameterList(D->getTemplateParameters());
1618   Record.AddASTTemplateArgumentListInfo(D->getTemplateArgsAsWritten());
1619 
1620   VisitVarTemplateSpecializationDecl(D);
1621 
1622   // These are read/set from/to the first declaration.
1623   if (D->getPreviousDecl() == nullptr) {
1624     Record.AddDeclRef(D->getInstantiatedFromMember());
1625     Record.push_back(D->isMemberSpecialization());
1626   }
1627 
1628   Code = serialization::DECL_VAR_TEMPLATE_PARTIAL_SPECIALIZATION;
1629 }
1630 
1631 void ASTDeclWriter::VisitClassScopeFunctionSpecializationDecl(
1632                                     ClassScopeFunctionSpecializationDecl *D) {
1633   VisitDecl(D);
1634   Record.AddDeclRef(D->getSpecialization());
1635   Record.push_back(D->hasExplicitTemplateArgs());
1636   if (D->hasExplicitTemplateArgs())
1637     Record.AddASTTemplateArgumentListInfo(D->getTemplateArgsAsWritten());
1638   Code = serialization::DECL_CLASS_SCOPE_FUNCTION_SPECIALIZATION;
1639 }
1640 
1641 
1642 void ASTDeclWriter::VisitFunctionTemplateDecl(FunctionTemplateDecl *D) {
1643   VisitRedeclarableTemplateDecl(D);
1644 
1645   if (D->isFirstDecl())
1646     AddTemplateSpecializations(D);
1647   Code = serialization::DECL_FUNCTION_TEMPLATE;
1648 }
1649 
1650 void ASTDeclWriter::VisitTemplateTypeParmDecl(TemplateTypeParmDecl *D) {
1651   Record.push_back(D->hasTypeConstraint());
1652   VisitTypeDecl(D);
1653 
1654   Record.push_back(D->wasDeclaredWithTypename());
1655 
1656   const TypeConstraint *TC = D->getTypeConstraint();
1657   Record.push_back(TC != nullptr);
1658   if (TC) {
1659     Record.AddNestedNameSpecifierLoc(TC->getNestedNameSpecifierLoc());
1660     Record.AddDeclarationNameInfo(TC->getConceptNameInfo());
1661     Record.AddDeclRef(TC->getNamedConcept());
1662     Record.push_back(TC->getTemplateArgsAsWritten() != nullptr);
1663     if (TC->getTemplateArgsAsWritten())
1664       Record.AddASTTemplateArgumentListInfo(TC->getTemplateArgsAsWritten());
1665     Record.AddStmt(TC->getImmediatelyDeclaredConstraint());
1666     Record.push_back(D->isExpandedParameterPack());
1667     if (D->isExpandedParameterPack())
1668       Record.push_back(D->getNumExpansionParameters());
1669   }
1670 
1671   bool OwnsDefaultArg = D->hasDefaultArgument() &&
1672                         !D->defaultArgumentWasInherited();
1673   Record.push_back(OwnsDefaultArg);
1674   if (OwnsDefaultArg)
1675     Record.AddTypeSourceInfo(D->getDefaultArgumentInfo());
1676 
1677   Code = serialization::DECL_TEMPLATE_TYPE_PARM;
1678 }
1679 
1680 void ASTDeclWriter::VisitNonTypeTemplateParmDecl(NonTypeTemplateParmDecl *D) {
1681   // For an expanded parameter pack, record the number of expansion types here
1682   // so that it's easier for deserialization to allocate the right amount of
1683   // memory.
1684   Expr *TypeConstraint = D->getPlaceholderTypeConstraint();
1685   Record.push_back(!!TypeConstraint);
1686   if (D->isExpandedParameterPack())
1687     Record.push_back(D->getNumExpansionTypes());
1688 
1689   VisitDeclaratorDecl(D);
1690   // TemplateParmPosition.
1691   Record.push_back(D->getDepth());
1692   Record.push_back(D->getPosition());
1693   if (TypeConstraint)
1694     Record.AddStmt(TypeConstraint);
1695 
1696   if (D->isExpandedParameterPack()) {
1697     for (unsigned I = 0, N = D->getNumExpansionTypes(); I != N; ++I) {
1698       Record.AddTypeRef(D->getExpansionType(I));
1699       Record.AddTypeSourceInfo(D->getExpansionTypeSourceInfo(I));
1700     }
1701 
1702     Code = serialization::DECL_EXPANDED_NON_TYPE_TEMPLATE_PARM_PACK;
1703   } else {
1704     // Rest of NonTypeTemplateParmDecl.
1705     Record.push_back(D->isParameterPack());
1706     bool OwnsDefaultArg = D->hasDefaultArgument() &&
1707                           !D->defaultArgumentWasInherited();
1708     Record.push_back(OwnsDefaultArg);
1709     if (OwnsDefaultArg)
1710       Record.AddStmt(D->getDefaultArgument());
1711     Code = serialization::DECL_NON_TYPE_TEMPLATE_PARM;
1712   }
1713 }
1714 
1715 void ASTDeclWriter::VisitTemplateTemplateParmDecl(TemplateTemplateParmDecl *D) {
1716   // For an expanded parameter pack, record the number of expansion types here
1717   // so that it's easier for deserialization to allocate the right amount of
1718   // memory.
1719   if (D->isExpandedParameterPack())
1720     Record.push_back(D->getNumExpansionTemplateParameters());
1721 
1722   VisitTemplateDecl(D);
1723   // TemplateParmPosition.
1724   Record.push_back(D->getDepth());
1725   Record.push_back(D->getPosition());
1726 
1727   if (D->isExpandedParameterPack()) {
1728     for (unsigned I = 0, N = D->getNumExpansionTemplateParameters();
1729          I != N; ++I)
1730       Record.AddTemplateParameterList(D->getExpansionTemplateParameters(I));
1731     Code = serialization::DECL_EXPANDED_TEMPLATE_TEMPLATE_PARM_PACK;
1732   } else {
1733     // Rest of TemplateTemplateParmDecl.
1734     Record.push_back(D->isParameterPack());
1735     bool OwnsDefaultArg = D->hasDefaultArgument() &&
1736                           !D->defaultArgumentWasInherited();
1737     Record.push_back(OwnsDefaultArg);
1738     if (OwnsDefaultArg)
1739       Record.AddTemplateArgumentLoc(D->getDefaultArgument());
1740     Code = serialization::DECL_TEMPLATE_TEMPLATE_PARM;
1741   }
1742 }
1743 
1744 void ASTDeclWriter::VisitTypeAliasTemplateDecl(TypeAliasTemplateDecl *D) {
1745   VisitRedeclarableTemplateDecl(D);
1746   Code = serialization::DECL_TYPE_ALIAS_TEMPLATE;
1747 }
1748 
1749 void ASTDeclWriter::VisitStaticAssertDecl(StaticAssertDecl *D) {
1750   VisitDecl(D);
1751   Record.AddStmt(D->getAssertExpr());
1752   Record.push_back(D->isFailed());
1753   Record.AddStmt(D->getMessage());
1754   Record.AddSourceLocation(D->getRParenLoc());
1755   Code = serialization::DECL_STATIC_ASSERT;
1756 }
1757 
1758 /// Emit the DeclContext part of a declaration context decl.
1759 void ASTDeclWriter::VisitDeclContext(DeclContext *DC) {
1760   Record.AddOffset(Writer.WriteDeclContextLexicalBlock(Context, DC));
1761   Record.AddOffset(Writer.WriteDeclContextVisibleBlock(Context, DC));
1762 }
1763 
1764 const Decl *ASTWriter::getFirstLocalDecl(const Decl *D) {
1765   assert(IsLocalDecl(D) && "expected a local declaration");
1766 
1767   const Decl *Canon = D->getCanonicalDecl();
1768   if (IsLocalDecl(Canon))
1769     return Canon;
1770 
1771   const Decl *&CacheEntry = FirstLocalDeclCache[Canon];
1772   if (CacheEntry)
1773     return CacheEntry;
1774 
1775   for (const Decl *Redecl = D; Redecl; Redecl = Redecl->getPreviousDecl())
1776     if (IsLocalDecl(Redecl))
1777       D = Redecl;
1778   return CacheEntry = D;
1779 }
1780 
1781 template <typename T>
1782 void ASTDeclWriter::VisitRedeclarable(Redeclarable<T> *D) {
1783   T *First = D->getFirstDecl();
1784   T *MostRecent = First->getMostRecentDecl();
1785   T *DAsT = static_cast<T *>(D);
1786   if (MostRecent != First) {
1787     assert(isRedeclarableDeclKind(DAsT->getKind()) &&
1788            "Not considered redeclarable?");
1789 
1790     Record.AddDeclRef(First);
1791 
1792     // Write out a list of local redeclarations of this declaration if it's the
1793     // first local declaration in the chain.
1794     const Decl *FirstLocal = Writer.getFirstLocalDecl(DAsT);
1795     if (DAsT == FirstLocal) {
1796       // Emit a list of all imported first declarations so that we can be sure
1797       // that all redeclarations visible to this module are before D in the
1798       // redecl chain.
1799       unsigned I = Record.size();
1800       Record.push_back(0);
1801       if (Writer.Chain)
1802         AddFirstDeclFromEachModule(DAsT, /*IncludeLocal*/false);
1803       // This is the number of imported first declarations + 1.
1804       Record[I] = Record.size() - I;
1805 
1806       // Collect the set of local redeclarations of this declaration, from
1807       // newest to oldest.
1808       ASTWriter::RecordData LocalRedecls;
1809       ASTRecordWriter LocalRedeclWriter(Record, LocalRedecls);
1810       for (const Decl *Prev = FirstLocal->getMostRecentDecl();
1811            Prev != FirstLocal; Prev = Prev->getPreviousDecl())
1812         if (!Prev->isFromASTFile())
1813           LocalRedeclWriter.AddDeclRef(Prev);
1814 
1815       // If we have any redecls, write them now as a separate record preceding
1816       // the declaration itself.
1817       if (LocalRedecls.empty())
1818         Record.push_back(0);
1819       else
1820         Record.AddOffset(LocalRedeclWriter.Emit(LOCAL_REDECLARATIONS));
1821     } else {
1822       Record.push_back(0);
1823       Record.AddDeclRef(FirstLocal);
1824     }
1825 
1826     // Make sure that we serialize both the previous and the most-recent
1827     // declarations, which (transitively) ensures that all declarations in the
1828     // chain get serialized.
1829     //
1830     // FIXME: This is not correct; when we reach an imported declaration we
1831     // won't emit its previous declaration.
1832     (void)Writer.GetDeclRef(D->getPreviousDecl());
1833     (void)Writer.GetDeclRef(MostRecent);
1834   } else {
1835     // We use the sentinel value 0 to indicate an only declaration.
1836     Record.push_back(0);
1837   }
1838 }
1839 
1840 void ASTDeclWriter::VisitOMPThreadPrivateDecl(OMPThreadPrivateDecl *D) {
1841   Record.writeOMPChildren(D->Data);
1842   VisitDecl(D);
1843   Code = serialization::DECL_OMP_THREADPRIVATE;
1844 }
1845 
1846 void ASTDeclWriter::VisitOMPAllocateDecl(OMPAllocateDecl *D) {
1847   Record.writeOMPChildren(D->Data);
1848   VisitDecl(D);
1849   Code = serialization::DECL_OMP_ALLOCATE;
1850 }
1851 
1852 void ASTDeclWriter::VisitOMPRequiresDecl(OMPRequiresDecl *D) {
1853   Record.writeOMPChildren(D->Data);
1854   VisitDecl(D);
1855   Code = serialization::DECL_OMP_REQUIRES;
1856 }
1857 
1858 void ASTDeclWriter::VisitOMPDeclareReductionDecl(OMPDeclareReductionDecl *D) {
1859   VisitValueDecl(D);
1860   Record.AddSourceLocation(D->getBeginLoc());
1861   Record.AddStmt(D->getCombinerIn());
1862   Record.AddStmt(D->getCombinerOut());
1863   Record.AddStmt(D->getCombiner());
1864   Record.AddStmt(D->getInitOrig());
1865   Record.AddStmt(D->getInitPriv());
1866   Record.AddStmt(D->getInitializer());
1867   Record.push_back(D->getInitializerKind());
1868   Record.AddDeclRef(D->getPrevDeclInScope());
1869   Code = serialization::DECL_OMP_DECLARE_REDUCTION;
1870 }
1871 
1872 void ASTDeclWriter::VisitOMPDeclareMapperDecl(OMPDeclareMapperDecl *D) {
1873   Record.writeOMPChildren(D->Data);
1874   VisitValueDecl(D);
1875   Record.AddDeclarationName(D->getVarName());
1876   Record.AddDeclRef(D->getPrevDeclInScope());
1877   Code = serialization::DECL_OMP_DECLARE_MAPPER;
1878 }
1879 
1880 void ASTDeclWriter::VisitOMPCapturedExprDecl(OMPCapturedExprDecl *D) {
1881   VisitVarDecl(D);
1882   Code = serialization::DECL_OMP_CAPTUREDEXPR;
1883 }
1884 
1885 //===----------------------------------------------------------------------===//
1886 // ASTWriter Implementation
1887 //===----------------------------------------------------------------------===//
1888 
1889 void ASTWriter::WriteDeclAbbrevs() {
1890   using namespace llvm;
1891 
1892   std::shared_ptr<BitCodeAbbrev> Abv;
1893 
1894   // Abbreviation for DECL_FIELD
1895   Abv = std::make_shared<BitCodeAbbrev>();
1896   Abv->Add(BitCodeAbbrevOp(serialization::DECL_FIELD));
1897   // Decl
1898   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclContext
1899   Abv->Add(BitCodeAbbrevOp(0));                       // LexicalDeclContext
1900   Abv->Add(BitCodeAbbrevOp(0));                       // isInvalidDecl
1901   Abv->Add(BitCodeAbbrevOp(0));                       // HasAttrs
1902   Abv->Add(BitCodeAbbrevOp(0));                       // isImplicit
1903   Abv->Add(BitCodeAbbrevOp(0));                       // isUsed
1904   Abv->Add(BitCodeAbbrevOp(0));                       // isReferenced
1905   Abv->Add(BitCodeAbbrevOp(0));                   // TopLevelDeclInObjCContainer
1906   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2));  // AccessSpecifier
1907   Abv->Add(BitCodeAbbrevOp(0));                       // ModulePrivate
1908   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // SubmoduleID
1909   // NamedDecl
1910   Abv->Add(BitCodeAbbrevOp(0));                       // NameKind = Identifier
1911   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Name
1912   Abv->Add(BitCodeAbbrevOp(0));                       // AnonDeclNumber
1913   // ValueDecl
1914   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
1915   // DeclaratorDecl
1916   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // InnerStartLoc
1917   Abv->Add(BitCodeAbbrevOp(0));                       // hasExtInfo
1918   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // TSIType
1919   // FieldDecl
1920   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isMutable
1921   Abv->Add(BitCodeAbbrevOp(0));                       // InitStyle
1922   // Type Source Info
1923   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1924   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // TypeLoc
1925   DeclFieldAbbrev = Stream.EmitAbbrev(std::move(Abv));
1926 
1927   // Abbreviation for DECL_OBJC_IVAR
1928   Abv = std::make_shared<BitCodeAbbrev>();
1929   Abv->Add(BitCodeAbbrevOp(serialization::DECL_OBJC_IVAR));
1930   // Decl
1931   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclContext
1932   Abv->Add(BitCodeAbbrevOp(0));                       // LexicalDeclContext
1933   Abv->Add(BitCodeAbbrevOp(0));                       // isInvalidDecl
1934   Abv->Add(BitCodeAbbrevOp(0));                       // HasAttrs
1935   Abv->Add(BitCodeAbbrevOp(0));                       // isImplicit
1936   Abv->Add(BitCodeAbbrevOp(0));                       // isUsed
1937   Abv->Add(BitCodeAbbrevOp(0));                       // isReferenced
1938   Abv->Add(BitCodeAbbrevOp(0));                   // TopLevelDeclInObjCContainer
1939   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2));  // AccessSpecifier
1940   Abv->Add(BitCodeAbbrevOp(0));                       // ModulePrivate
1941   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // SubmoduleID
1942   // NamedDecl
1943   Abv->Add(BitCodeAbbrevOp(0));                       // NameKind = Identifier
1944   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Name
1945   Abv->Add(BitCodeAbbrevOp(0));                       // AnonDeclNumber
1946   // ValueDecl
1947   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
1948   // DeclaratorDecl
1949   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // InnerStartLoc
1950   Abv->Add(BitCodeAbbrevOp(0));                       // hasExtInfo
1951   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // TSIType
1952   // FieldDecl
1953   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isMutable
1954   Abv->Add(BitCodeAbbrevOp(0));                       // InitStyle
1955   // ObjC Ivar
1956   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // getAccessControl
1957   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // getSynthesize
1958   // Type Source Info
1959   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1960   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // TypeLoc
1961   DeclObjCIvarAbbrev = Stream.EmitAbbrev(std::move(Abv));
1962 
1963   // Abbreviation for DECL_ENUM
1964   Abv = std::make_shared<BitCodeAbbrev>();
1965   Abv->Add(BitCodeAbbrevOp(serialization::DECL_ENUM));
1966   // Redeclarable
1967   Abv->Add(BitCodeAbbrevOp(0));                       // No redeclaration
1968   // Decl
1969   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclContext
1970   Abv->Add(BitCodeAbbrevOp(0));                       // LexicalDeclContext
1971   Abv->Add(BitCodeAbbrevOp(0));                       // isInvalidDecl
1972   Abv->Add(BitCodeAbbrevOp(0));                       // HasAttrs
1973   Abv->Add(BitCodeAbbrevOp(0));                       // isImplicit
1974   Abv->Add(BitCodeAbbrevOp(0));                       // isUsed
1975   Abv->Add(BitCodeAbbrevOp(0));                       // isReferenced
1976   Abv->Add(BitCodeAbbrevOp(0));                   // TopLevelDeclInObjCContainer
1977   Abv->Add(BitCodeAbbrevOp(AS_none));                 // C++ AccessSpecifier
1978   Abv->Add(BitCodeAbbrevOp(0));                       // ModulePrivate
1979   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // SubmoduleID
1980   // NamedDecl
1981   Abv->Add(BitCodeAbbrevOp(0));                       // NameKind = Identifier
1982   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Name
1983   Abv->Add(BitCodeAbbrevOp(0));                       // AnonDeclNumber
1984   // TypeDecl
1985   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Source Location
1986   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type Ref
1987   // TagDecl
1988   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // IdentifierNamespace
1989   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // getTagKind
1990   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isCompleteDefinition
1991   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // EmbeddedInDeclarator
1992   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsFreeStanding
1993   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsCompleteDefinitionRequired
1994   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // SourceLocation
1995   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // SourceLocation
1996   Abv->Add(BitCodeAbbrevOp(0));                         // ExtInfoKind
1997   // EnumDecl
1998   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // AddTypeRef
1999   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // IntegerType
2000   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // getPromotionType
2001   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // getNumPositiveBits
2002   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // getNumNegativeBits
2003   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isScoped
2004   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isScopedUsingClassTag
2005   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isFixed
2006   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));// ODRHash
2007   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // InstantiatedMembEnum
2008   // DC
2009   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // LexicalOffset
2010   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // VisibleOffset
2011   DeclEnumAbbrev = Stream.EmitAbbrev(std::move(Abv));
2012 
2013   // Abbreviation for DECL_RECORD
2014   Abv = std::make_shared<BitCodeAbbrev>();
2015   Abv->Add(BitCodeAbbrevOp(serialization::DECL_RECORD));
2016   // Redeclarable
2017   Abv->Add(BitCodeAbbrevOp(0));                       // No redeclaration
2018   // Decl
2019   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclContext
2020   Abv->Add(BitCodeAbbrevOp(0));                       // LexicalDeclContext
2021   Abv->Add(BitCodeAbbrevOp(0));                       // isInvalidDecl
2022   Abv->Add(BitCodeAbbrevOp(0));                       // HasAttrs
2023   Abv->Add(BitCodeAbbrevOp(0));                       // isImplicit
2024   Abv->Add(BitCodeAbbrevOp(0));                       // isUsed
2025   Abv->Add(BitCodeAbbrevOp(0));                       // isReferenced
2026   Abv->Add(BitCodeAbbrevOp(0));                   // TopLevelDeclInObjCContainer
2027   Abv->Add(BitCodeAbbrevOp(AS_none));                 // C++ AccessSpecifier
2028   Abv->Add(BitCodeAbbrevOp(0));                       // ModulePrivate
2029   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // SubmoduleID
2030   // NamedDecl
2031   Abv->Add(BitCodeAbbrevOp(0));                       // NameKind = Identifier
2032   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Name
2033   Abv->Add(BitCodeAbbrevOp(0));                       // AnonDeclNumber
2034   // TypeDecl
2035   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Source Location
2036   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type Ref
2037   // TagDecl
2038   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // IdentifierNamespace
2039   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // getTagKind
2040   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isCompleteDefinition
2041   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // EmbeddedInDeclarator
2042   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsFreeStanding
2043   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsCompleteDefinitionRequired
2044   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // SourceLocation
2045   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // SourceLocation
2046   Abv->Add(BitCodeAbbrevOp(0));                         // ExtInfoKind
2047   // RecordDecl
2048   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // FlexibleArrayMember
2049   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // AnonymousStructUnion
2050   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // hasObjectMember
2051   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // hasVolatileMember
2052 
2053   // isNonTrivialToPrimitiveDefaultInitialize
2054   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
2055   // isNonTrivialToPrimitiveCopy
2056   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
2057   // isNonTrivialToPrimitiveDestroy
2058   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
2059   // hasNonTrivialToPrimitiveDefaultInitializeCUnion
2060   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
2061   // hasNonTrivialToPrimitiveDestructCUnion
2062   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
2063   // hasNonTrivialToPrimitiveCopyCUnion
2064   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
2065   // isParamDestroyedInCallee
2066   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
2067   // getArgPassingRestrictions
2068   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2));
2069 
2070   // DC
2071   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // LexicalOffset
2072   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // VisibleOffset
2073   DeclRecordAbbrev = Stream.EmitAbbrev(std::move(Abv));
2074 
2075   // Abbreviation for DECL_PARM_VAR
2076   Abv = std::make_shared<BitCodeAbbrev>();
2077   Abv->Add(BitCodeAbbrevOp(serialization::DECL_PARM_VAR));
2078   // Redeclarable
2079   Abv->Add(BitCodeAbbrevOp(0));                       // No redeclaration
2080   // Decl
2081   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclContext
2082   Abv->Add(BitCodeAbbrevOp(0));                       // LexicalDeclContext
2083   Abv->Add(BitCodeAbbrevOp(0));                       // isInvalidDecl
2084   Abv->Add(BitCodeAbbrevOp(0));                       // HasAttrs
2085   Abv->Add(BitCodeAbbrevOp(0));                       // isImplicit
2086   Abv->Add(BitCodeAbbrevOp(0));                       // isUsed
2087   Abv->Add(BitCodeAbbrevOp(0));                       // isReferenced
2088   Abv->Add(BitCodeAbbrevOp(0));                   // TopLevelDeclInObjCContainer
2089   Abv->Add(BitCodeAbbrevOp(AS_none));                 // C++ AccessSpecifier
2090   Abv->Add(BitCodeAbbrevOp(0));                       // ModulePrivate
2091   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // SubmoduleID
2092   // NamedDecl
2093   Abv->Add(BitCodeAbbrevOp(0));                       // NameKind = Identifier
2094   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Name
2095   Abv->Add(BitCodeAbbrevOp(0));                       // AnonDeclNumber
2096   // ValueDecl
2097   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
2098   // DeclaratorDecl
2099   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // InnerStartLoc
2100   Abv->Add(BitCodeAbbrevOp(0));                       // hasExtInfo
2101   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // TSIType
2102   // VarDecl
2103   Abv->Add(BitCodeAbbrevOp(0));                       // SClass
2104   Abv->Add(BitCodeAbbrevOp(0));                       // TSCSpec
2105   Abv->Add(BitCodeAbbrevOp(0));                       // InitStyle
2106   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isARCPseudoStrong
2107   Abv->Add(BitCodeAbbrevOp(0));                       // Linkage
2108   Abv->Add(BitCodeAbbrevOp(0));                       // HasInit
2109   Abv->Add(BitCodeAbbrevOp(0));                   // HasMemberSpecializationInfo
2110   // ParmVarDecl
2111   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsObjCMethodParameter
2112   Abv->Add(BitCodeAbbrevOp(0));                       // ScopeDepth
2113   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // ScopeIndex
2114   Abv->Add(BitCodeAbbrevOp(0));                       // ObjCDeclQualifier
2115   Abv->Add(BitCodeAbbrevOp(0));                       // KNRPromoted
2116   Abv->Add(BitCodeAbbrevOp(0));                       // HasInheritedDefaultArg
2117   Abv->Add(BitCodeAbbrevOp(0));                   // HasUninstantiatedDefaultArg
2118   // Type Source Info
2119   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2120   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // TypeLoc
2121   DeclParmVarAbbrev = Stream.EmitAbbrev(std::move(Abv));
2122 
2123   // Abbreviation for DECL_TYPEDEF
2124   Abv = std::make_shared<BitCodeAbbrev>();
2125   Abv->Add(BitCodeAbbrevOp(serialization::DECL_TYPEDEF));
2126   // Redeclarable
2127   Abv->Add(BitCodeAbbrevOp(0));                       // No redeclaration
2128   // Decl
2129   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclContext
2130   Abv->Add(BitCodeAbbrevOp(0));                       // LexicalDeclContext
2131   Abv->Add(BitCodeAbbrevOp(0));                       // isInvalidDecl
2132   Abv->Add(BitCodeAbbrevOp(0));                       // HasAttrs
2133   Abv->Add(BitCodeAbbrevOp(0));                       // isImplicit
2134   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isUsed
2135   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isReferenced
2136   Abv->Add(BitCodeAbbrevOp(0));                   // TopLevelDeclInObjCContainer
2137   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2)); // C++ AccessSpecifier
2138   Abv->Add(BitCodeAbbrevOp(0));                       // ModulePrivate
2139   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // SubmoduleID
2140   // NamedDecl
2141   Abv->Add(BitCodeAbbrevOp(0));                       // NameKind = Identifier
2142   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Name
2143   Abv->Add(BitCodeAbbrevOp(0));                       // AnonDeclNumber
2144   // TypeDecl
2145   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Source Location
2146   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type Ref
2147   // TypedefDecl
2148   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2149   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // TypeLoc
2150   DeclTypedefAbbrev = Stream.EmitAbbrev(std::move(Abv));
2151 
2152   // Abbreviation for DECL_VAR
2153   Abv = std::make_shared<BitCodeAbbrev>();
2154   Abv->Add(BitCodeAbbrevOp(serialization::DECL_VAR));
2155   // Redeclarable
2156   Abv->Add(BitCodeAbbrevOp(0));                       // No redeclaration
2157   // Decl
2158   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclContext
2159   Abv->Add(BitCodeAbbrevOp(0));                       // LexicalDeclContext
2160   Abv->Add(BitCodeAbbrevOp(0));                       // isInvalidDecl
2161   Abv->Add(BitCodeAbbrevOp(0));                       // HasAttrs
2162   Abv->Add(BitCodeAbbrevOp(0));                       // isImplicit
2163   Abv->Add(BitCodeAbbrevOp(0));                       // isUsed
2164   Abv->Add(BitCodeAbbrevOp(0));                       // isReferenced
2165   Abv->Add(BitCodeAbbrevOp(0));                   // TopLevelDeclInObjCContainer
2166   Abv->Add(BitCodeAbbrevOp(AS_none));                 // C++ AccessSpecifier
2167   Abv->Add(BitCodeAbbrevOp(0));                       // ModulePrivate
2168   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // SubmoduleID
2169   // NamedDecl
2170   Abv->Add(BitCodeAbbrevOp(0));                       // NameKind = Identifier
2171   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Name
2172   Abv->Add(BitCodeAbbrevOp(0));                       // AnonDeclNumber
2173   // ValueDecl
2174   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
2175   // DeclaratorDecl
2176   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // InnerStartLoc
2177   Abv->Add(BitCodeAbbrevOp(0));                       // hasExtInfo
2178   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // TSIType
2179   // VarDecl
2180   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); // SClass
2181   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2)); // TSCSpec
2182   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2)); // InitStyle
2183   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isARCPseudoStrong
2184   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsThisDeclarationADemotedDefinition
2185   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isExceptionVariable
2186   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isNRVOVariable
2187   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isCXXForRangeDecl
2188   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isObjCForDecl
2189   Abv->Add(BitCodeAbbrevOp(0));                         // isInline
2190   Abv->Add(BitCodeAbbrevOp(0));                         // isInlineSpecified
2191   Abv->Add(BitCodeAbbrevOp(0));                         // isConstexpr
2192   Abv->Add(BitCodeAbbrevOp(0));                         // isInitCapture
2193   Abv->Add(BitCodeAbbrevOp(0));                         // isPrevDeclInSameScope
2194   Abv->Add(BitCodeAbbrevOp(0));                         // ImplicitParamKind
2195   Abv->Add(BitCodeAbbrevOp(0));                         // EscapingByref
2196   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); // Linkage
2197   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); // HasConstant*
2198   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2)); // VarKind (local enum)
2199   // Type Source Info
2200   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2201   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // TypeLoc
2202   DeclVarAbbrev = Stream.EmitAbbrev(std::move(Abv));
2203 
2204   // Abbreviation for DECL_CXX_METHOD
2205   Abv = std::make_shared<BitCodeAbbrev>();
2206   Abv->Add(BitCodeAbbrevOp(serialization::DECL_CXX_METHOD));
2207   // RedeclarableDecl
2208   Abv->Add(BitCodeAbbrevOp(0));                         // CanonicalDecl
2209   // Decl
2210   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // DeclContext
2211   Abv->Add(BitCodeAbbrevOp(0));                         // LexicalDeclContext
2212   Abv->Add(BitCodeAbbrevOp(0));                         // Invalid
2213   Abv->Add(BitCodeAbbrevOp(0));                         // HasAttrs
2214   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Implicit
2215   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Used
2216   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Referenced
2217   Abv->Add(BitCodeAbbrevOp(0));                         // InObjCContainer
2218   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2)); // Access
2219   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // ModulePrivate
2220   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // SubmoduleID
2221   // NamedDecl
2222   Abv->Add(BitCodeAbbrevOp(DeclarationName::Identifier)); // NameKind
2223   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // Identifier
2224   Abv->Add(BitCodeAbbrevOp(0));                         // AnonDeclNumber
2225   // ValueDecl
2226   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // Type
2227   // DeclaratorDecl
2228   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // InnerLocStart
2229   Abv->Add(BitCodeAbbrevOp(0));                         // HasExtInfo
2230   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // TSIType
2231   // FunctionDecl
2232   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 11)); // IDNS
2233   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); // StorageClass
2234   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Inline
2235   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // InlineSpecified
2236   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // VirtualAsWritten
2237   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Pure
2238   Abv->Add(BitCodeAbbrevOp(0));                         // HasInheritedProto
2239   Abv->Add(BitCodeAbbrevOp(1));                         // HasWrittenProto
2240   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Deleted
2241   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Trivial
2242   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // TrivialForCall
2243   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Defaulted
2244   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // ExplicitlyDefaulted
2245   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // ImplicitReturnZero
2246   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Constexpr
2247   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // UsesSEHTry
2248   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // SkippedBody
2249   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // MultiVersion
2250   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // LateParsed
2251   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); // Linkage
2252   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // LocEnd
2253   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // ODRHash
2254   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); // TemplateKind
2255   // This Array slurps the rest of the record. Fortunately we want to encode
2256   // (nearly) all the remaining (variable number of) fields in the same way.
2257   //
2258   // This is the function template information if any, then
2259   //         NumParams and Params[] from FunctionDecl, and
2260   //         NumOverriddenMethods, OverriddenMethods[] from CXXMethodDecl.
2261   //
2262   //  Add an AbbrevOp for 'size then elements' and use it here.
2263   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2264   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
2265   DeclCXXMethodAbbrev = Stream.EmitAbbrev(std::move(Abv));
2266 
2267   // Abbreviation for EXPR_DECL_REF
2268   Abv = std::make_shared<BitCodeAbbrev>();
2269   Abv->Add(BitCodeAbbrevOp(serialization::EXPR_DECL_REF));
2270   //Stmt
2271   // Expr
2272   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
2273   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //TypeDependent
2274   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //ValueDependent
2275   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //InstantiationDependent
2276   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //UnexpandedParamPack
2277   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //ContainsErrors
2278   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetValueKind
2279   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetObjectKind
2280   //DeclRefExpr
2281   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //HasQualifier
2282   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //GetDeclFound
2283   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //ExplicitTemplateArgs
2284   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //HadMultipleCandidates
2285   Abv->Add(BitCodeAbbrevOp(0)); // RefersToEnclosingVariableOrCapture
2286   Abv->Add(BitCodeAbbrevOp(0)); // NonOdrUseReason
2287   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclRef
2288   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Location
2289   DeclRefExprAbbrev = Stream.EmitAbbrev(std::move(Abv));
2290 
2291   // Abbreviation for EXPR_INTEGER_LITERAL
2292   Abv = std::make_shared<BitCodeAbbrev>();
2293   Abv->Add(BitCodeAbbrevOp(serialization::EXPR_INTEGER_LITERAL));
2294   //Stmt
2295   // Expr
2296   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
2297   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //TypeDependent
2298   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //ValueDependent
2299   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //InstantiationDependent
2300   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //UnexpandedParamPack
2301   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //ContainsErrors
2302   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetValueKind
2303   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetObjectKind
2304   //Integer Literal
2305   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Location
2306   Abv->Add(BitCodeAbbrevOp(32));                      // Bit Width
2307   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Value
2308   IntegerLiteralAbbrev = Stream.EmitAbbrev(std::move(Abv));
2309 
2310   // Abbreviation for EXPR_CHARACTER_LITERAL
2311   Abv = std::make_shared<BitCodeAbbrev>();
2312   Abv->Add(BitCodeAbbrevOp(serialization::EXPR_CHARACTER_LITERAL));
2313   //Stmt
2314   // Expr
2315   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
2316   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //TypeDependent
2317   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //ValueDependent
2318   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //InstantiationDependent
2319   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //UnexpandedParamPack
2320   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //ContainsErrors
2321   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetValueKind
2322   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetObjectKind
2323   //Character Literal
2324   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // getValue
2325   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Location
2326   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); // getKind
2327   CharacterLiteralAbbrev = Stream.EmitAbbrev(std::move(Abv));
2328 
2329   // Abbreviation for EXPR_IMPLICIT_CAST
2330   Abv = std::make_shared<BitCodeAbbrev>();
2331   Abv->Add(BitCodeAbbrevOp(serialization::EXPR_IMPLICIT_CAST));
2332   // Stmt
2333   // Expr
2334   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
2335   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //TypeDependent
2336   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //ValueDependent
2337   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //InstantiationDependent
2338   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //UnexpandedParamPack
2339   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //ContainsErrors
2340   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetValueKind
2341   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetObjectKind
2342   // CastExpr
2343   Abv->Add(BitCodeAbbrevOp(0)); // PathSize
2344   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // HasFPFeatures
2345   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 6)); // CastKind
2346   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // PartOfExplicitCast
2347   // ImplicitCastExpr
2348   ExprImplicitCastAbbrev = Stream.EmitAbbrev(std::move(Abv));
2349 
2350   Abv = std::make_shared<BitCodeAbbrev>();
2351   Abv->Add(BitCodeAbbrevOp(serialization::DECL_CONTEXT_LEXICAL));
2352   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
2353   DeclContextLexicalAbbrev = Stream.EmitAbbrev(std::move(Abv));
2354 
2355   Abv = std::make_shared<BitCodeAbbrev>();
2356   Abv->Add(BitCodeAbbrevOp(serialization::DECL_CONTEXT_VISIBLE));
2357   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
2358   DeclContextVisibleLookupAbbrev = Stream.EmitAbbrev(std::move(Abv));
2359 }
2360 
2361 /// isRequiredDecl - Check if this is a "required" Decl, which must be seen by
2362 /// consumers of the AST.
2363 ///
2364 /// Such decls will always be deserialized from the AST file, so we would like
2365 /// this to be as restrictive as possible. Currently the predicate is driven by
2366 /// code generation requirements, if other clients have a different notion of
2367 /// what is "required" then we may have to consider an alternate scheme where
2368 /// clients can iterate over the top-level decls and get information on them,
2369 /// without necessary deserializing them. We could explicitly require such
2370 /// clients to use a separate API call to "realize" the decl. This should be
2371 /// relatively painless since they would presumably only do it for top-level
2372 /// decls.
2373 static bool isRequiredDecl(const Decl *D, ASTContext &Context,
2374                            bool WritingModule) {
2375   // An ObjCMethodDecl is never considered as "required" because its
2376   // implementation container always is.
2377 
2378   // File scoped assembly or obj-c or OMP declare target implementation must be
2379   // seen.
2380   if (isa<FileScopeAsmDecl>(D) || isa<ObjCImplDecl>(D))
2381     return true;
2382 
2383   if (WritingModule && isPartOfPerModuleInitializer(D)) {
2384     // These declarations are part of the module initializer, and are emitted
2385     // if and when the module is imported, rather than being emitted eagerly.
2386     return false;
2387   }
2388 
2389   return Context.DeclMustBeEmitted(D);
2390 }
2391 
2392 void ASTWriter::WriteDecl(ASTContext &Context, Decl *D) {
2393   PrettyDeclStackTraceEntry CrashInfo(Context, D, SourceLocation(),
2394                                       "serializing");
2395 
2396   // Determine the ID for this declaration.
2397   serialization::DeclID ID;
2398   assert(!D->isFromASTFile() && "should not be emitting imported decl");
2399   serialization::DeclID &IDR = DeclIDs[D];
2400   if (IDR == 0)
2401     IDR = NextDeclID++;
2402 
2403   ID = IDR;
2404 
2405   assert(ID >= FirstDeclID && "invalid decl ID");
2406 
2407   RecordData Record;
2408   ASTDeclWriter W(*this, Context, Record);
2409 
2410   // Build a record for this declaration
2411   W.Visit(D);
2412 
2413   // Emit this declaration to the bitstream.
2414   uint64_t Offset = W.Emit(D);
2415 
2416   // Record the offset for this declaration
2417   SourceLocation Loc = D->getLocation();
2418   unsigned Index = ID - FirstDeclID;
2419   if (DeclOffsets.size() == Index)
2420     DeclOffsets.emplace_back(Loc, Offset, DeclTypesBlockStartOffset);
2421   else if (DeclOffsets.size() < Index) {
2422     // FIXME: Can/should this happen?
2423     DeclOffsets.resize(Index+1);
2424     DeclOffsets[Index].setLocation(Loc);
2425     DeclOffsets[Index].setBitOffset(Offset, DeclTypesBlockStartOffset);
2426   } else {
2427     llvm_unreachable("declarations should be emitted in ID order");
2428   }
2429 
2430   SourceManager &SM = Context.getSourceManager();
2431   if (Loc.isValid() && SM.isLocalSourceLocation(Loc))
2432     associateDeclWithFile(D, ID);
2433 
2434   // Note declarations that should be deserialized eagerly so that we can add
2435   // them to a record in the AST file later.
2436   if (isRequiredDecl(D, Context, WritingModule))
2437     EagerlyDeserializedDecls.push_back(ID);
2438 }
2439 
2440 void ASTRecordWriter::AddFunctionDefinition(const FunctionDecl *FD) {
2441   // Switch case IDs are per function body.
2442   Writer->ClearSwitchCaseIDs();
2443 
2444   assert(FD->doesThisDeclarationHaveABody());
2445   bool ModulesCodegen = false;
2446   if (!FD->isDependentContext()) {
2447     Optional<GVALinkage> Linkage;
2448     if (Writer->WritingModule &&
2449         Writer->WritingModule->Kind == Module::ModuleInterfaceUnit) {
2450       // When building a C++ Modules TS module interface unit, a strong
2451       // definition in the module interface is provided by the compilation of
2452       // that module interface unit, not by its users. (Inline functions are
2453       // still emitted in module users.)
2454       Linkage = Writer->Context->GetGVALinkageForFunction(FD);
2455       ModulesCodegen = *Linkage == GVA_StrongExternal;
2456     }
2457     if (Writer->Context->getLangOpts().ModulesCodegen ||
2458         (FD->hasAttr<DLLExportAttr>() &&
2459          Writer->Context->getLangOpts().BuildingPCHWithObjectFile)) {
2460 
2461       // Under -fmodules-codegen, codegen is performed for all non-internal,
2462       // non-always_inline functions, unless they are available elsewhere.
2463       if (!FD->hasAttr<AlwaysInlineAttr>()) {
2464         if (!Linkage)
2465           Linkage = Writer->Context->GetGVALinkageForFunction(FD);
2466         ModulesCodegen =
2467             *Linkage != GVA_Internal && *Linkage != GVA_AvailableExternally;
2468       }
2469     }
2470   }
2471   Record->push_back(ModulesCodegen);
2472   if (ModulesCodegen)
2473     Writer->ModularCodegenDecls.push_back(Writer->GetDeclRef(FD));
2474   if (auto *CD = dyn_cast<CXXConstructorDecl>(FD)) {
2475     Record->push_back(CD->getNumCtorInitializers());
2476     if (CD->getNumCtorInitializers())
2477       AddCXXCtorInitializers(
2478           llvm::makeArrayRef(CD->init_begin(), CD->init_end()));
2479   }
2480   AddStmt(FD->getBody());
2481 }
2482