xref: /freebsd-src/contrib/llvm-project/clang/lib/Serialization/ASTWriterDecl.cpp (revision 753f127f3ace09432b2baeffd71a308760641a62) 
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/DeclTemplate.h"
17 #include "clang/AST/DeclVisitor.h"
18 #include "clang/AST/Expr.h"
19 #include "clang/AST/OpenMPClause.h"
20 #include "clang/AST/PrettyDeclStackTrace.h"
21 #include "clang/Basic/SourceManager.h"
22 #include "clang/Serialization/ASTReader.h"
23 #include "clang/Serialization/ASTRecordWriter.h"
24 #include "llvm/Bitstream/BitstreamWriter.h"
25 #include "llvm/Support/ErrorHandling.h"
26 using namespace clang;
27 using namespace serialization;
28 
29 //===----------------------------------------------------------------------===//
30 // Declaration serialization
31 //===----------------------------------------------------------------------===//
32 
33 namespace clang {
34   class ASTDeclWriter : public DeclVisitor<ASTDeclWriter, void> {
35     ASTWriter &Writer;
36     ASTContext &Context;
37     ASTRecordWriter Record;
38 
39     serialization::DeclCode Code;
40     unsigned AbbrevToUse;
41 
42   public:
43     ASTDeclWriter(ASTWriter &Writer, ASTContext &Context,
44                   ASTWriter::RecordDataImpl &Record)
45         : Writer(Writer), Context(Context), Record(Writer, Record),
46           Code((serialization::DeclCode)0), AbbrevToUse(0) {}
47 
48     uint64_t Emit(Decl *D) {
49       if (!Code)
50         llvm::report_fatal_error(StringRef("unexpected declaration kind '") +
51             D->getDeclKindName() + "'");
52       return Record.Emit(Code, AbbrevToUse);
53     }
54 
55     void Visit(Decl *D);
56 
57     void VisitDecl(Decl *D);
58     void VisitPragmaCommentDecl(PragmaCommentDecl *D);
59     void VisitPragmaDetectMismatchDecl(PragmaDetectMismatchDecl *D);
60     void VisitTranslationUnitDecl(TranslationUnitDecl *D);
61     void VisitNamedDecl(NamedDecl *D);
62     void VisitLabelDecl(LabelDecl *LD);
63     void VisitNamespaceDecl(NamespaceDecl *D);
64     void VisitUsingDirectiveDecl(UsingDirectiveDecl *D);
65     void VisitNamespaceAliasDecl(NamespaceAliasDecl *D);
66     void VisitTypeDecl(TypeDecl *D);
67     void VisitTypedefNameDecl(TypedefNameDecl *D);
68     void VisitTypedefDecl(TypedefDecl *D);
69     void VisitTypeAliasDecl(TypeAliasDecl *D);
70     void VisitUnresolvedUsingTypenameDecl(UnresolvedUsingTypenameDecl *D);
71     void VisitUnresolvedUsingIfExistsDecl(UnresolvedUsingIfExistsDecl *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 VisitUnnamedGlobalConstantDecl(UnnamedGlobalConstantDecl *D);
100     void VisitTemplateParamObjectDecl(TemplateParamObjectDecl *D);
101     void VisitIndirectFieldDecl(IndirectFieldDecl *D);
102     void VisitVarDecl(VarDecl *D);
103     void VisitImplicitParamDecl(ImplicitParamDecl *D);
104     void VisitParmVarDecl(ParmVarDecl *D);
105     void VisitDecompositionDecl(DecompositionDecl *D);
106     void VisitBindingDecl(BindingDecl *D);
107     void VisitNonTypeTemplateParmDecl(NonTypeTemplateParmDecl *D);
108     void VisitTemplateDecl(TemplateDecl *D);
109     void VisitConceptDecl(ConceptDecl *D);
110     void VisitRequiresExprBodyDecl(RequiresExprBodyDecl *D);
111     void VisitRedeclarableTemplateDecl(RedeclarableTemplateDecl *D);
112     void VisitClassTemplateDecl(ClassTemplateDecl *D);
113     void VisitVarTemplateDecl(VarTemplateDecl *D);
114     void VisitFunctionTemplateDecl(FunctionTemplateDecl *D);
115     void VisitTemplateTemplateParmDecl(TemplateTemplateParmDecl *D);
116     void VisitTypeAliasTemplateDecl(TypeAliasTemplateDecl *D);
117     void VisitUsingDecl(UsingDecl *D);
118     void VisitUsingEnumDecl(UsingEnumDecl *D);
119     void VisitUsingPackDecl(UsingPackDecl *D);
120     void VisitUsingShadowDecl(UsingShadowDecl *D);
121     void VisitConstructorUsingShadowDecl(ConstructorUsingShadowDecl *D);
122     void VisitLinkageSpecDecl(LinkageSpecDecl *D);
123     void VisitExportDecl(ExportDecl *D);
124     void VisitFileScopeAsmDecl(FileScopeAsmDecl *D);
125     void VisitImportDecl(ImportDecl *D);
126     void VisitAccessSpecDecl(AccessSpecDecl *D);
127     void VisitFriendDecl(FriendDecl *D);
128     void VisitFriendTemplateDecl(FriendTemplateDecl *D);
129     void VisitStaticAssertDecl(StaticAssertDecl *D);
130     void VisitBlockDecl(BlockDecl *D);
131     void VisitCapturedDecl(CapturedDecl *D);
132     void VisitEmptyDecl(EmptyDecl *D);
133     void VisitLifetimeExtendedTemporaryDecl(LifetimeExtendedTemporaryDecl *D);
134 
135     void VisitDeclContext(DeclContext *DC);
136     template <typename T> void VisitRedeclarable(Redeclarable<T> *D);
137 
138 
139     // FIXME: Put in the same order is DeclNodes.td?
140     void VisitObjCMethodDecl(ObjCMethodDecl *D);
141     void VisitObjCTypeParamDecl(ObjCTypeParamDecl *D);
142     void VisitObjCContainerDecl(ObjCContainerDecl *D);
143     void VisitObjCInterfaceDecl(ObjCInterfaceDecl *D);
144     void VisitObjCIvarDecl(ObjCIvarDecl *D);
145     void VisitObjCProtocolDecl(ObjCProtocolDecl *D);
146     void VisitObjCAtDefsFieldDecl(ObjCAtDefsFieldDecl *D);
147     void VisitObjCCategoryDecl(ObjCCategoryDecl *D);
148     void VisitObjCImplDecl(ObjCImplDecl *D);
149     void VisitObjCCategoryImplDecl(ObjCCategoryImplDecl *D);
150     void VisitObjCImplementationDecl(ObjCImplementationDecl *D);
151     void VisitObjCCompatibleAliasDecl(ObjCCompatibleAliasDecl *D);
152     void VisitObjCPropertyDecl(ObjCPropertyDecl *D);
153     void VisitObjCPropertyImplDecl(ObjCPropertyImplDecl *D);
154     void VisitOMPThreadPrivateDecl(OMPThreadPrivateDecl *D);
155     void VisitOMPAllocateDecl(OMPAllocateDecl *D);
156     void VisitOMPRequiresDecl(OMPRequiresDecl *D);
157     void VisitOMPDeclareReductionDecl(OMPDeclareReductionDecl *D);
158     void VisitOMPDeclareMapperDecl(OMPDeclareMapperDecl *D);
159     void VisitOMPCapturedExprDecl(OMPCapturedExprDecl *D);
160 
161     /// Add an Objective-C type parameter list to the given record.
162     void AddObjCTypeParamList(ObjCTypeParamList *typeParams) {
163       // Empty type parameter list.
164       if (!typeParams) {
165         Record.push_back(0);
166         return;
167       }
168 
169       Record.push_back(typeParams->size());
170       for (auto typeParam : *typeParams) {
171         Record.AddDeclRef(typeParam);
172       }
173       Record.AddSourceLocation(typeParams->getLAngleLoc());
174       Record.AddSourceLocation(typeParams->getRAngleLoc());
175     }
176 
177     /// Add to the record the first declaration from each module file that
178     /// provides a declaration of D. The intent is to provide a sufficient
179     /// set such that reloading this set will load all current redeclarations.
180     void AddFirstDeclFromEachModule(const Decl *D, bool IncludeLocal) {
181       llvm::MapVector<ModuleFile*, const Decl*> Firsts;
182       // FIXME: We can skip entries that we know are implied by others.
183       for (const Decl *R = D->getMostRecentDecl(); R; R = R->getPreviousDecl()) {
184         if (R->isFromASTFile())
185           Firsts[Writer.Chain->getOwningModuleFile(R)] = R;
186         else if (IncludeLocal)
187           Firsts[nullptr] = R;
188       }
189       for (const auto &F : Firsts)
190         Record.AddDeclRef(F.second);
191     }
192 
193     /// Get the specialization decl from an entry in the specialization list.
194     template <typename EntryType>
195     typename RedeclarableTemplateDecl::SpecEntryTraits<EntryType>::DeclType *
196     getSpecializationDecl(EntryType &T) {
197       return RedeclarableTemplateDecl::SpecEntryTraits<EntryType>::getDecl(&T);
198     }
199 
200     /// Get the list of partial specializations from a template's common ptr.
201     template<typename T>
202     decltype(T::PartialSpecializations) &getPartialSpecializations(T *Common) {
203       return Common->PartialSpecializations;
204     }
205     ArrayRef<Decl> getPartialSpecializations(FunctionTemplateDecl::Common *) {
206       return None;
207     }
208 
209     template<typename DeclTy>
210     void AddTemplateSpecializations(DeclTy *D) {
211       auto *Common = D->getCommonPtr();
212 
213       // If we have any lazy specializations, and the external AST source is
214       // our chained AST reader, we can just write out the DeclIDs. Otherwise,
215       // we need to resolve them to actual declarations.
216       if (Writer.Chain != Writer.Context->getExternalSource() &&
217           Common->LazySpecializations) {
218         D->LoadLazySpecializations();
219         assert(!Common->LazySpecializations);
220       }
221 
222       ArrayRef<DeclID> LazySpecializations;
223       if (auto *LS = Common->LazySpecializations)
224         LazySpecializations = llvm::makeArrayRef(LS + 1, LS[0]);
225 
226       // Add a slot to the record for the number of specializations.
227       unsigned I = Record.size();
228       Record.push_back(0);
229 
230       // AddFirstDeclFromEachModule might trigger deserialization, invalidating
231       // *Specializations iterators.
232       llvm::SmallVector<const Decl*, 16> Specs;
233       for (auto &Entry : Common->Specializations)
234         Specs.push_back(getSpecializationDecl(Entry));
235       for (auto &Entry : getPartialSpecializations(Common))
236         Specs.push_back(getSpecializationDecl(Entry));
237 
238       for (auto *D : Specs) {
239         assert(D->isCanonicalDecl() && "non-canonical decl in set");
240         AddFirstDeclFromEachModule(D, /*IncludeLocal*/true);
241       }
242       Record.append(LazySpecializations.begin(), LazySpecializations.end());
243 
244       // Update the size entry we added earlier.
245       Record[I] = Record.size() - I - 1;
246     }
247 
248     /// Ensure that this template specialization is associated with the specified
249     /// template on reload.
250     void RegisterTemplateSpecialization(const Decl *Template,
251                                         const Decl *Specialization) {
252       Template = Template->getCanonicalDecl();
253 
254       // If the canonical template is local, we'll write out this specialization
255       // when we emit it.
256       // FIXME: We can do the same thing if there is any local declaration of
257       // the template, to avoid emitting an update record.
258       if (!Template->isFromASTFile())
259         return;
260 
261       // We only need to associate the first local declaration of the
262       // specialization. The other declarations will get pulled in by it.
263       if (Writer.getFirstLocalDecl(Specialization) != Specialization)
264         return;
265 
266       Writer.DeclUpdates[Template].push_back(ASTWriter::DeclUpdate(
267           UPD_CXX_ADDED_TEMPLATE_SPECIALIZATION, Specialization));
268     }
269   };
270 }
271 
272 void ASTDeclWriter::Visit(Decl *D) {
273   DeclVisitor<ASTDeclWriter>::Visit(D);
274 
275   // Source locations require array (variable-length) abbreviations.  The
276   // abbreviation infrastructure requires that arrays are encoded last, so
277   // we handle it here in the case of those classes derived from DeclaratorDecl
278   if (DeclaratorDecl *DD = dyn_cast<DeclaratorDecl>(D)) {
279     if (auto *TInfo = DD->getTypeSourceInfo())
280       Record.AddTypeLoc(TInfo->getTypeLoc());
281   }
282 
283   // Handle FunctionDecl's body here and write it after all other Stmts/Exprs
284   // have been written. We want it last because we will not read it back when
285   // retrieving it from the AST, we'll just lazily set the offset.
286   if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
287     Record.push_back(FD->doesThisDeclarationHaveABody());
288     if (FD->doesThisDeclarationHaveABody())
289       Record.AddFunctionDefinition(FD);
290   }
291 
292   // If this declaration is also a DeclContext, write blocks for the
293   // declarations that lexically stored inside its context and those
294   // declarations that are visible from its context.
295   if (DeclContext *DC = dyn_cast<DeclContext>(D))
296     VisitDeclContext(DC);
297 }
298 
299 void ASTDeclWriter::VisitDecl(Decl *D) {
300   Record.AddDeclRef(cast_or_null<Decl>(D->getDeclContext()));
301   if (D->getDeclContext() != D->getLexicalDeclContext())
302     Record.AddDeclRef(cast_or_null<Decl>(D->getLexicalDeclContext()));
303   else
304     Record.push_back(0);
305   Record.push_back(D->isInvalidDecl());
306   Record.push_back(D->hasAttrs());
307   if (D->hasAttrs())
308     Record.AddAttributes(D->getAttrs());
309   Record.push_back(D->isImplicit());
310   Record.push_back(D->isUsed(false));
311   Record.push_back(D->isReferenced());
312   Record.push_back(D->isTopLevelDeclInObjCContainer());
313   Record.push_back(D->getAccess());
314   Record.push_back((uint64_t)D->getModuleOwnershipKind());
315   Record.push_back(Writer.getSubmoduleID(D->getOwningModule()));
316 
317   // If this declaration injected a name into a context different from its
318   // lexical context, and that context is an imported namespace, we need to
319   // update its visible declarations to include this name.
320   //
321   // This happens when we instantiate a class with a friend declaration or a
322   // function with a local extern declaration, for instance.
323   //
324   // FIXME: Can we handle this in AddedVisibleDecl instead?
325   if (D->isOutOfLine()) {
326     auto *DC = D->getDeclContext();
327     while (auto *NS = dyn_cast<NamespaceDecl>(DC->getRedeclContext())) {
328       if (!NS->isFromASTFile())
329         break;
330       Writer.UpdatedDeclContexts.insert(NS->getPrimaryContext());
331       if (!NS->isInlineNamespace())
332         break;
333       DC = NS->getParent();
334     }
335   }
336 }
337 
338 void ASTDeclWriter::VisitPragmaCommentDecl(PragmaCommentDecl *D) {
339   StringRef Arg = D->getArg();
340   Record.push_back(Arg.size());
341   VisitDecl(D);
342   Record.AddSourceLocation(D->getBeginLoc());
343   Record.push_back(D->getCommentKind());
344   Record.AddString(Arg);
345   Code = serialization::DECL_PRAGMA_COMMENT;
346 }
347 
348 void ASTDeclWriter::VisitPragmaDetectMismatchDecl(
349     PragmaDetectMismatchDecl *D) {
350   StringRef Name = D->getName();
351   StringRef Value = D->getValue();
352   Record.push_back(Name.size() + 1 + Value.size());
353   VisitDecl(D);
354   Record.AddSourceLocation(D->getBeginLoc());
355   Record.AddString(Name);
356   Record.AddString(Value);
357   Code = serialization::DECL_PRAGMA_DETECT_MISMATCH;
358 }
359 
360 void ASTDeclWriter::VisitTranslationUnitDecl(TranslationUnitDecl *D) {
361   llvm_unreachable("Translation units aren't directly serialized");
362 }
363 
364 void ASTDeclWriter::VisitNamedDecl(NamedDecl *D) {
365   VisitDecl(D);
366   Record.AddDeclarationName(D->getDeclName());
367   Record.push_back(needsAnonymousDeclarationNumber(D)
368                        ? Writer.getAnonymousDeclarationNumber(D)
369                        : 0);
370 }
371 
372 void ASTDeclWriter::VisitTypeDecl(TypeDecl *D) {
373   VisitNamedDecl(D);
374   Record.AddSourceLocation(D->getBeginLoc());
375   Record.AddTypeRef(QualType(D->getTypeForDecl(), 0));
376 }
377 
378 void ASTDeclWriter::VisitTypedefNameDecl(TypedefNameDecl *D) {
379   VisitRedeclarable(D);
380   VisitTypeDecl(D);
381   Record.AddTypeSourceInfo(D->getTypeSourceInfo());
382   Record.push_back(D->isModed());
383   if (D->isModed())
384     Record.AddTypeRef(D->getUnderlyingType());
385   Record.AddDeclRef(D->getAnonDeclWithTypedefName(false));
386 }
387 
388 void ASTDeclWriter::VisitTypedefDecl(TypedefDecl *D) {
389   VisitTypedefNameDecl(D);
390   if (D->getDeclContext() == D->getLexicalDeclContext() &&
391       !D->hasAttrs() &&
392       !D->isImplicit() &&
393       D->getFirstDecl() == D->getMostRecentDecl() &&
394       !D->isInvalidDecl() &&
395       !D->isTopLevelDeclInObjCContainer() &&
396       !D->isModulePrivate() &&
397       !needsAnonymousDeclarationNumber(D) &&
398       D->getDeclName().getNameKind() == DeclarationName::Identifier)
399     AbbrevToUse = Writer.getDeclTypedefAbbrev();
400 
401   Code = serialization::DECL_TYPEDEF;
402 }
403 
404 void ASTDeclWriter::VisitTypeAliasDecl(TypeAliasDecl *D) {
405   VisitTypedefNameDecl(D);
406   Record.AddDeclRef(D->getDescribedAliasTemplate());
407   Code = serialization::DECL_TYPEALIAS;
408 }
409 
410 void ASTDeclWriter::VisitTagDecl(TagDecl *D) {
411   VisitRedeclarable(D);
412   VisitTypeDecl(D);
413   Record.push_back(D->getIdentifierNamespace());
414   Record.push_back((unsigned)D->getTagKind()); // FIXME: stable encoding
415   if (!isa<CXXRecordDecl>(D))
416     Record.push_back(D->isCompleteDefinition());
417   Record.push_back(D->isEmbeddedInDeclarator());
418   Record.push_back(D->isFreeStanding());
419   Record.push_back(D->isCompleteDefinitionRequired());
420   Record.AddSourceRange(D->getBraceRange());
421 
422   if (D->hasExtInfo()) {
423     Record.push_back(1);
424     Record.AddQualifierInfo(*D->getExtInfo());
425   } else if (auto *TD = D->getTypedefNameForAnonDecl()) {
426     Record.push_back(2);
427     Record.AddDeclRef(TD);
428     Record.AddIdentifierRef(TD->getDeclName().getAsIdentifierInfo());
429   } else {
430     Record.push_back(0);
431   }
432 }
433 
434 void ASTDeclWriter::VisitEnumDecl(EnumDecl *D) {
435   VisitTagDecl(D);
436   Record.AddTypeSourceInfo(D->getIntegerTypeSourceInfo());
437   if (!D->getIntegerTypeSourceInfo())
438     Record.AddTypeRef(D->getIntegerType());
439   Record.AddTypeRef(D->getPromotionType());
440   Record.push_back(D->getNumPositiveBits());
441   Record.push_back(D->getNumNegativeBits());
442   Record.push_back(D->isScoped());
443   Record.push_back(D->isScopedUsingClassTag());
444   Record.push_back(D->isFixed());
445   Record.push_back(D->getODRHash());
446 
447   if (MemberSpecializationInfo *MemberInfo = D->getMemberSpecializationInfo()) {
448     Record.AddDeclRef(MemberInfo->getInstantiatedFrom());
449     Record.push_back(MemberInfo->getTemplateSpecializationKind());
450     Record.AddSourceLocation(MemberInfo->getPointOfInstantiation());
451   } else {
452     Record.AddDeclRef(nullptr);
453   }
454 
455   if (D->getDeclContext() == D->getLexicalDeclContext() &&
456       !D->hasAttrs() &&
457       !D->isImplicit() &&
458       !D->isUsed(false) &&
459       !D->hasExtInfo() &&
460       !D->getTypedefNameForAnonDecl() &&
461       D->getFirstDecl() == D->getMostRecentDecl() &&
462       !D->isInvalidDecl() &&
463       !D->isReferenced() &&
464       !D->isTopLevelDeclInObjCContainer() &&
465       D->getAccess() == AS_none &&
466       !D->isModulePrivate() &&
467       !CXXRecordDecl::classofKind(D->getKind()) &&
468       !D->getIntegerTypeSourceInfo() &&
469       !D->getMemberSpecializationInfo() &&
470       !needsAnonymousDeclarationNumber(D) &&
471       D->getDeclName().getNameKind() == DeclarationName::Identifier)
472     AbbrevToUse = Writer.getDeclEnumAbbrev();
473 
474   Code = serialization::DECL_ENUM;
475 }
476 
477 void ASTDeclWriter::VisitRecordDecl(RecordDecl *D) {
478   VisitTagDecl(D);
479   Record.push_back(D->hasFlexibleArrayMember());
480   Record.push_back(D->isAnonymousStructOrUnion());
481   Record.push_back(D->hasObjectMember());
482   Record.push_back(D->hasVolatileMember());
483   Record.push_back(D->isNonTrivialToPrimitiveDefaultInitialize());
484   Record.push_back(D->isNonTrivialToPrimitiveCopy());
485   Record.push_back(D->isNonTrivialToPrimitiveDestroy());
486   Record.push_back(D->hasNonTrivialToPrimitiveDefaultInitializeCUnion());
487   Record.push_back(D->hasNonTrivialToPrimitiveDestructCUnion());
488   Record.push_back(D->hasNonTrivialToPrimitiveCopyCUnion());
489   Record.push_back(D->isParamDestroyedInCallee());
490   Record.push_back(D->getArgPassingRestrictions());
491 
492   if (D->getDeclContext() == D->getLexicalDeclContext() &&
493       !D->hasAttrs() &&
494       !D->isImplicit() &&
495       !D->isUsed(false) &&
496       !D->hasExtInfo() &&
497       !D->getTypedefNameForAnonDecl() &&
498       D->getFirstDecl() == D->getMostRecentDecl() &&
499       !D->isInvalidDecl() &&
500       !D->isReferenced() &&
501       !D->isTopLevelDeclInObjCContainer() &&
502       D->getAccess() == AS_none &&
503       !D->isModulePrivate() &&
504       !CXXRecordDecl::classofKind(D->getKind()) &&
505       !needsAnonymousDeclarationNumber(D) &&
506       D->getDeclName().getNameKind() == DeclarationName::Identifier)
507     AbbrevToUse = Writer.getDeclRecordAbbrev();
508 
509   Code = serialization::DECL_RECORD;
510 }
511 
512 void ASTDeclWriter::VisitValueDecl(ValueDecl *D) {
513   VisitNamedDecl(D);
514   Record.AddTypeRef(D->getType());
515 }
516 
517 void ASTDeclWriter::VisitEnumConstantDecl(EnumConstantDecl *D) {
518   VisitValueDecl(D);
519   Record.push_back(D->getInitExpr()? 1 : 0);
520   if (D->getInitExpr())
521     Record.AddStmt(D->getInitExpr());
522   Record.AddAPSInt(D->getInitVal());
523 
524   Code = serialization::DECL_ENUM_CONSTANT;
525 }
526 
527 void ASTDeclWriter::VisitDeclaratorDecl(DeclaratorDecl *D) {
528   VisitValueDecl(D);
529   Record.AddSourceLocation(D->getInnerLocStart());
530   Record.push_back(D->hasExtInfo());
531   if (D->hasExtInfo()) {
532     DeclaratorDecl::ExtInfo *Info = D->getExtInfo();
533     Record.AddQualifierInfo(*Info);
534     Record.AddStmt(Info->TrailingRequiresClause);
535   }
536   // The location information is deferred until the end of the record.
537   Record.AddTypeRef(D->getTypeSourceInfo() ? D->getTypeSourceInfo()->getType()
538                                            : QualType());
539 }
540 
541 void ASTDeclWriter::VisitFunctionDecl(FunctionDecl *D) {
542   VisitRedeclarable(D);
543   VisitDeclaratorDecl(D);
544   Record.AddDeclarationNameLoc(D->DNLoc, D->getDeclName());
545   Record.push_back(D->getIdentifierNamespace());
546 
547   // FunctionDecl's body is handled last at ASTWriterDecl::Visit,
548   // after everything else is written.
549   Record.push_back(static_cast<int>(D->getStorageClass())); // FIXME: stable encoding
550   Record.push_back(D->isInlineSpecified());
551   Record.push_back(D->isInlined());
552   Record.push_back(D->isVirtualAsWritten());
553   Record.push_back(D->isPure());
554   Record.push_back(D->hasInheritedPrototype());
555   Record.push_back(D->hasWrittenPrototype());
556   Record.push_back(D->isDeletedBit());
557   Record.push_back(D->isTrivial());
558   Record.push_back(D->isTrivialForCall());
559   Record.push_back(D->isDefaulted());
560   Record.push_back(D->isExplicitlyDefaulted());
561   Record.push_back(D->hasImplicitReturnZero());
562   Record.push_back(static_cast<uint64_t>(D->getConstexprKind()));
563   Record.push_back(D->usesSEHTry());
564   Record.push_back(D->hasSkippedBody());
565   Record.push_back(D->isMultiVersion());
566   Record.push_back(D->isLateTemplateParsed());
567   Record.push_back(D->getLinkageInternal());
568   Record.AddSourceLocation(D->getEndLoc());
569 
570   Record.push_back(D->getODRHash());
571 
572   if (D->isDefaulted()) {
573     if (auto *FDI = D->getDefaultedFunctionInfo()) {
574       Record.push_back(FDI->getUnqualifiedLookups().size());
575       for (DeclAccessPair P : FDI->getUnqualifiedLookups()) {
576         Record.AddDeclRef(P.getDecl());
577         Record.push_back(P.getAccess());
578       }
579     } else {
580       Record.push_back(0);
581     }
582   }
583 
584   Record.push_back(D->getTemplatedKind());
585   switch (D->getTemplatedKind()) {
586   case FunctionDecl::TK_NonTemplate:
587     break;
588   case FunctionDecl::TK_FunctionTemplate:
589     Record.AddDeclRef(D->getDescribedFunctionTemplate());
590     break;
591   case FunctionDecl::TK_MemberSpecialization: {
592     MemberSpecializationInfo *MemberInfo = D->getMemberSpecializationInfo();
593     Record.AddDeclRef(MemberInfo->getInstantiatedFrom());
594     Record.push_back(MemberInfo->getTemplateSpecializationKind());
595     Record.AddSourceLocation(MemberInfo->getPointOfInstantiation());
596     break;
597   }
598   case FunctionDecl::TK_FunctionTemplateSpecialization: {
599     FunctionTemplateSpecializationInfo *
600       FTSInfo = D->getTemplateSpecializationInfo();
601 
602     RegisterTemplateSpecialization(FTSInfo->getTemplate(), D);
603 
604     Record.AddDeclRef(FTSInfo->getTemplate());
605     Record.push_back(FTSInfo->getTemplateSpecializationKind());
606 
607     // Template arguments.
608     Record.AddTemplateArgumentList(FTSInfo->TemplateArguments);
609 
610     // Template args as written.
611     Record.push_back(FTSInfo->TemplateArgumentsAsWritten != nullptr);
612     if (FTSInfo->TemplateArgumentsAsWritten) {
613       Record.push_back(FTSInfo->TemplateArgumentsAsWritten->NumTemplateArgs);
614       for (int i=0, e = FTSInfo->TemplateArgumentsAsWritten->NumTemplateArgs;
615              i!=e; ++i)
616         Record.AddTemplateArgumentLoc(
617             (*FTSInfo->TemplateArgumentsAsWritten)[i]);
618       Record.AddSourceLocation(FTSInfo->TemplateArgumentsAsWritten->LAngleLoc);
619       Record.AddSourceLocation(FTSInfo->TemplateArgumentsAsWritten->RAngleLoc);
620     }
621 
622     Record.AddSourceLocation(FTSInfo->getPointOfInstantiation());
623 
624     if (MemberSpecializationInfo *MemberInfo =
625         FTSInfo->getMemberSpecializationInfo()) {
626       Record.push_back(1);
627       Record.AddDeclRef(MemberInfo->getInstantiatedFrom());
628       Record.push_back(MemberInfo->getTemplateSpecializationKind());
629       Record.AddSourceLocation(MemberInfo->getPointOfInstantiation());
630     } else {
631       Record.push_back(0);
632     }
633 
634     if (D->isCanonicalDecl()) {
635       // Write the template that contains the specializations set. We will
636       // add a FunctionTemplateSpecializationInfo to it when reading.
637       Record.AddDeclRef(FTSInfo->getTemplate()->getCanonicalDecl());
638     }
639     break;
640   }
641   case FunctionDecl::TK_DependentFunctionTemplateSpecialization: {
642     DependentFunctionTemplateSpecializationInfo *
643       DFTSInfo = D->getDependentSpecializationInfo();
644 
645     // Templates.
646     Record.push_back(DFTSInfo->getNumTemplates());
647     for (int i=0, e = DFTSInfo->getNumTemplates(); i != e; ++i)
648       Record.AddDeclRef(DFTSInfo->getTemplate(i));
649 
650     // Templates args.
651     Record.push_back(DFTSInfo->getNumTemplateArgs());
652     for (int i=0, e = DFTSInfo->getNumTemplateArgs(); i != e; ++i)
653       Record.AddTemplateArgumentLoc(DFTSInfo->getTemplateArg(i));
654     Record.AddSourceLocation(DFTSInfo->getLAngleLoc());
655     Record.AddSourceLocation(DFTSInfo->getRAngleLoc());
656     break;
657   }
658   }
659 
660   Record.push_back(D->param_size());
661   for (auto P : D->parameters())
662     Record.AddDeclRef(P);
663   Code = serialization::DECL_FUNCTION;
664 }
665 
666 static void addExplicitSpecifier(ExplicitSpecifier ES,
667                                  ASTRecordWriter &Record) {
668   uint64_t Kind = static_cast<uint64_t>(ES.getKind());
669   Kind = Kind << 1 | static_cast<bool>(ES.getExpr());
670   Record.push_back(Kind);
671   if (ES.getExpr()) {
672     Record.AddStmt(ES.getExpr());
673   }
674 }
675 
676 void ASTDeclWriter::VisitCXXDeductionGuideDecl(CXXDeductionGuideDecl *D) {
677   addExplicitSpecifier(D->getExplicitSpecifier(), Record);
678   Record.AddDeclRef(D->Ctor);
679   VisitFunctionDecl(D);
680   Record.push_back(D->isCopyDeductionCandidate());
681   Code = serialization::DECL_CXX_DEDUCTION_GUIDE;
682 }
683 
684 void ASTDeclWriter::VisitObjCMethodDecl(ObjCMethodDecl *D) {
685   VisitNamedDecl(D);
686   // FIXME: convert to LazyStmtPtr?
687   // Unlike C/C++, method bodies will never be in header files.
688   bool HasBodyStuff = D->getBody() != nullptr;
689   Record.push_back(HasBodyStuff);
690   if (HasBodyStuff) {
691     Record.AddStmt(D->getBody());
692   }
693   Record.AddDeclRef(D->getSelfDecl());
694   Record.AddDeclRef(D->getCmdDecl());
695   Record.push_back(D->isInstanceMethod());
696   Record.push_back(D->isVariadic());
697   Record.push_back(D->isPropertyAccessor());
698   Record.push_back(D->isSynthesizedAccessorStub());
699   Record.push_back(D->isDefined());
700   Record.push_back(D->isOverriding());
701   Record.push_back(D->hasSkippedBody());
702 
703   Record.push_back(D->isRedeclaration());
704   Record.push_back(D->hasRedeclaration());
705   if (D->hasRedeclaration()) {
706     assert(Context.getObjCMethodRedeclaration(D));
707     Record.AddDeclRef(Context.getObjCMethodRedeclaration(D));
708   }
709 
710   // FIXME: stable encoding for @required/@optional
711   Record.push_back(D->getImplementationControl());
712   // FIXME: stable encoding for in/out/inout/bycopy/byref/oneway/nullability
713   Record.push_back(D->getObjCDeclQualifier());
714   Record.push_back(D->hasRelatedResultType());
715   Record.AddTypeRef(D->getReturnType());
716   Record.AddTypeSourceInfo(D->getReturnTypeSourceInfo());
717   Record.AddSourceLocation(D->getEndLoc());
718   Record.push_back(D->param_size());
719   for (const auto *P : D->parameters())
720     Record.AddDeclRef(P);
721 
722   Record.push_back(D->getSelLocsKind());
723   unsigned NumStoredSelLocs = D->getNumStoredSelLocs();
724   SourceLocation *SelLocs = D->getStoredSelLocs();
725   Record.push_back(NumStoredSelLocs);
726   for (unsigned i = 0; i != NumStoredSelLocs; ++i)
727     Record.AddSourceLocation(SelLocs[i]);
728 
729   Code = serialization::DECL_OBJC_METHOD;
730 }
731 
732 void ASTDeclWriter::VisitObjCTypeParamDecl(ObjCTypeParamDecl *D) {
733   VisitTypedefNameDecl(D);
734   Record.push_back(D->Variance);
735   Record.push_back(D->Index);
736   Record.AddSourceLocation(D->VarianceLoc);
737   Record.AddSourceLocation(D->ColonLoc);
738 
739   Code = serialization::DECL_OBJC_TYPE_PARAM;
740 }
741 
742 void ASTDeclWriter::VisitObjCContainerDecl(ObjCContainerDecl *D) {
743   VisitNamedDecl(D);
744   Record.AddSourceLocation(D->getAtStartLoc());
745   Record.AddSourceRange(D->getAtEndRange());
746   // Abstract class (no need to define a stable serialization::DECL code).
747 }
748 
749 void ASTDeclWriter::VisitObjCInterfaceDecl(ObjCInterfaceDecl *D) {
750   VisitRedeclarable(D);
751   VisitObjCContainerDecl(D);
752   Record.AddTypeRef(QualType(D->getTypeForDecl(), 0));
753   AddObjCTypeParamList(D->TypeParamList);
754 
755   Record.push_back(D->isThisDeclarationADefinition());
756   if (D->isThisDeclarationADefinition()) {
757     // Write the DefinitionData
758     ObjCInterfaceDecl::DefinitionData &Data = D->data();
759 
760     Record.AddTypeSourceInfo(D->getSuperClassTInfo());
761     Record.AddSourceLocation(D->getEndOfDefinitionLoc());
762     Record.push_back(Data.HasDesignatedInitializers);
763 
764     // Write out the protocols that are directly referenced by the @interface.
765     Record.push_back(Data.ReferencedProtocols.size());
766     for (const auto *P : D->protocols())
767       Record.AddDeclRef(P);
768     for (const auto &PL : D->protocol_locs())
769       Record.AddSourceLocation(PL);
770 
771     // Write out the protocols that are transitively referenced.
772     Record.push_back(Data.AllReferencedProtocols.size());
773     for (ObjCList<ObjCProtocolDecl>::iterator
774               P = Data.AllReferencedProtocols.begin(),
775            PEnd = Data.AllReferencedProtocols.end();
776          P != PEnd; ++P)
777       Record.AddDeclRef(*P);
778 
779 
780     if (ObjCCategoryDecl *Cat = D->getCategoryListRaw()) {
781       // Ensure that we write out the set of categories for this class.
782       Writer.ObjCClassesWithCategories.insert(D);
783 
784       // Make sure that the categories get serialized.
785       for (; Cat; Cat = Cat->getNextClassCategoryRaw())
786         (void)Writer.GetDeclRef(Cat);
787     }
788   }
789 
790   Code = serialization::DECL_OBJC_INTERFACE;
791 }
792 
793 void ASTDeclWriter::VisitObjCIvarDecl(ObjCIvarDecl *D) {
794   VisitFieldDecl(D);
795   // FIXME: stable encoding for @public/@private/@protected/@package
796   Record.push_back(D->getAccessControl());
797   Record.push_back(D->getSynthesize());
798 
799   if (D->getDeclContext() == D->getLexicalDeclContext() &&
800       !D->hasAttrs() &&
801       !D->isImplicit() &&
802       !D->isUsed(false) &&
803       !D->isInvalidDecl() &&
804       !D->isReferenced() &&
805       !D->isModulePrivate() &&
806       !D->getBitWidth() &&
807       !D->hasExtInfo() &&
808       D->getDeclName())
809     AbbrevToUse = Writer.getDeclObjCIvarAbbrev();
810 
811   Code = serialization::DECL_OBJC_IVAR;
812 }
813 
814 void ASTDeclWriter::VisitObjCProtocolDecl(ObjCProtocolDecl *D) {
815   VisitRedeclarable(D);
816   VisitObjCContainerDecl(D);
817 
818   Record.push_back(D->isThisDeclarationADefinition());
819   if (D->isThisDeclarationADefinition()) {
820     Record.push_back(D->protocol_size());
821     for (const auto *I : D->protocols())
822       Record.AddDeclRef(I);
823     for (const auto &PL : D->protocol_locs())
824       Record.AddSourceLocation(PL);
825   }
826 
827   Code = serialization::DECL_OBJC_PROTOCOL;
828 }
829 
830 void ASTDeclWriter::VisitObjCAtDefsFieldDecl(ObjCAtDefsFieldDecl *D) {
831   VisitFieldDecl(D);
832   Code = serialization::DECL_OBJC_AT_DEFS_FIELD;
833 }
834 
835 void ASTDeclWriter::VisitObjCCategoryDecl(ObjCCategoryDecl *D) {
836   VisitObjCContainerDecl(D);
837   Record.AddSourceLocation(D->getCategoryNameLoc());
838   Record.AddSourceLocation(D->getIvarLBraceLoc());
839   Record.AddSourceLocation(D->getIvarRBraceLoc());
840   Record.AddDeclRef(D->getClassInterface());
841   AddObjCTypeParamList(D->TypeParamList);
842   Record.push_back(D->protocol_size());
843   for (const auto *I : D->protocols())
844     Record.AddDeclRef(I);
845   for (const auto &PL : D->protocol_locs())
846     Record.AddSourceLocation(PL);
847   Code = serialization::DECL_OBJC_CATEGORY;
848 }
849 
850 void ASTDeclWriter::VisitObjCCompatibleAliasDecl(ObjCCompatibleAliasDecl *D) {
851   VisitNamedDecl(D);
852   Record.AddDeclRef(D->getClassInterface());
853   Code = serialization::DECL_OBJC_COMPATIBLE_ALIAS;
854 }
855 
856 void ASTDeclWriter::VisitObjCPropertyDecl(ObjCPropertyDecl *D) {
857   VisitNamedDecl(D);
858   Record.AddSourceLocation(D->getAtLoc());
859   Record.AddSourceLocation(D->getLParenLoc());
860   Record.AddTypeRef(D->getType());
861   Record.AddTypeSourceInfo(D->getTypeSourceInfo());
862   // FIXME: stable encoding
863   Record.push_back((unsigned)D->getPropertyAttributes());
864   Record.push_back((unsigned)D->getPropertyAttributesAsWritten());
865   // FIXME: stable encoding
866   Record.push_back((unsigned)D->getPropertyImplementation());
867   Record.AddDeclarationName(D->getGetterName());
868   Record.AddSourceLocation(D->getGetterNameLoc());
869   Record.AddDeclarationName(D->getSetterName());
870   Record.AddSourceLocation(D->getSetterNameLoc());
871   Record.AddDeclRef(D->getGetterMethodDecl());
872   Record.AddDeclRef(D->getSetterMethodDecl());
873   Record.AddDeclRef(D->getPropertyIvarDecl());
874   Code = serialization::DECL_OBJC_PROPERTY;
875 }
876 
877 void ASTDeclWriter::VisitObjCImplDecl(ObjCImplDecl *D) {
878   VisitObjCContainerDecl(D);
879   Record.AddDeclRef(D->getClassInterface());
880   // Abstract class (no need to define a stable serialization::DECL code).
881 }
882 
883 void ASTDeclWriter::VisitObjCCategoryImplDecl(ObjCCategoryImplDecl *D) {
884   VisitObjCImplDecl(D);
885   Record.AddSourceLocation(D->getCategoryNameLoc());
886   Code = serialization::DECL_OBJC_CATEGORY_IMPL;
887 }
888 
889 void ASTDeclWriter::VisitObjCImplementationDecl(ObjCImplementationDecl *D) {
890   VisitObjCImplDecl(D);
891   Record.AddDeclRef(D->getSuperClass());
892   Record.AddSourceLocation(D->getSuperClassLoc());
893   Record.AddSourceLocation(D->getIvarLBraceLoc());
894   Record.AddSourceLocation(D->getIvarRBraceLoc());
895   Record.push_back(D->hasNonZeroConstructors());
896   Record.push_back(D->hasDestructors());
897   Record.push_back(D->NumIvarInitializers);
898   if (D->NumIvarInitializers)
899     Record.AddCXXCtorInitializers(
900         llvm::makeArrayRef(D->init_begin(), D->init_end()));
901   Code = serialization::DECL_OBJC_IMPLEMENTATION;
902 }
903 
904 void ASTDeclWriter::VisitObjCPropertyImplDecl(ObjCPropertyImplDecl *D) {
905   VisitDecl(D);
906   Record.AddSourceLocation(D->getBeginLoc());
907   Record.AddDeclRef(D->getPropertyDecl());
908   Record.AddDeclRef(D->getPropertyIvarDecl());
909   Record.AddSourceLocation(D->getPropertyIvarDeclLoc());
910   Record.AddDeclRef(D->getGetterMethodDecl());
911   Record.AddDeclRef(D->getSetterMethodDecl());
912   Record.AddStmt(D->getGetterCXXConstructor());
913   Record.AddStmt(D->getSetterCXXAssignment());
914   Code = serialization::DECL_OBJC_PROPERTY_IMPL;
915 }
916 
917 void ASTDeclWriter::VisitFieldDecl(FieldDecl *D) {
918   VisitDeclaratorDecl(D);
919   Record.push_back(D->isMutable());
920 
921   FieldDecl::InitStorageKind ISK = D->InitStorage.getInt();
922   Record.push_back(ISK);
923   if (ISK == FieldDecl::ISK_CapturedVLAType)
924     Record.AddTypeRef(QualType(D->getCapturedVLAType(), 0));
925   else if (ISK)
926     Record.AddStmt(D->getInClassInitializer());
927 
928   Record.AddStmt(D->getBitWidth());
929 
930   if (!D->getDeclName())
931     Record.AddDeclRef(Context.getInstantiatedFromUnnamedFieldDecl(D));
932 
933   if (D->getDeclContext() == D->getLexicalDeclContext() &&
934       !D->hasAttrs() &&
935       !D->isImplicit() &&
936       !D->isUsed(false) &&
937       !D->isInvalidDecl() &&
938       !D->isReferenced() &&
939       !D->isTopLevelDeclInObjCContainer() &&
940       !D->isModulePrivate() &&
941       !D->getBitWidth() &&
942       !D->hasInClassInitializer() &&
943       !D->hasCapturedVLAType() &&
944       !D->hasExtInfo() &&
945       !ObjCIvarDecl::classofKind(D->getKind()) &&
946       !ObjCAtDefsFieldDecl::classofKind(D->getKind()) &&
947       D->getDeclName())
948     AbbrevToUse = Writer.getDeclFieldAbbrev();
949 
950   Code = serialization::DECL_FIELD;
951 }
952 
953 void ASTDeclWriter::VisitMSPropertyDecl(MSPropertyDecl *D) {
954   VisitDeclaratorDecl(D);
955   Record.AddIdentifierRef(D->getGetterId());
956   Record.AddIdentifierRef(D->getSetterId());
957   Code = serialization::DECL_MS_PROPERTY;
958 }
959 
960 void ASTDeclWriter::VisitMSGuidDecl(MSGuidDecl *D) {
961   VisitValueDecl(D);
962   MSGuidDecl::Parts Parts = D->getParts();
963   Record.push_back(Parts.Part1);
964   Record.push_back(Parts.Part2);
965   Record.push_back(Parts.Part3);
966   Record.append(std::begin(Parts.Part4And5), std::end(Parts.Part4And5));
967   Code = serialization::DECL_MS_GUID;
968 }
969 
970 void ASTDeclWriter::VisitUnnamedGlobalConstantDecl(
971     UnnamedGlobalConstantDecl *D) {
972   VisitValueDecl(D);
973   Record.AddAPValue(D->getValue());
974   Code = serialization::DECL_UNNAMED_GLOBAL_CONSTANT;
975 }
976 
977 void ASTDeclWriter::VisitTemplateParamObjectDecl(TemplateParamObjectDecl *D) {
978   VisitValueDecl(D);
979   Record.AddAPValue(D->getValue());
980   Code = serialization::DECL_TEMPLATE_PARAM_OBJECT;
981 }
982 
983 void ASTDeclWriter::VisitIndirectFieldDecl(IndirectFieldDecl *D) {
984   VisitValueDecl(D);
985   Record.push_back(D->getChainingSize());
986 
987   for (const auto *P : D->chain())
988     Record.AddDeclRef(P);
989   Code = serialization::DECL_INDIRECTFIELD;
990 }
991 
992 void ASTDeclWriter::VisitVarDecl(VarDecl *D) {
993   VisitRedeclarable(D);
994   VisitDeclaratorDecl(D);
995   Record.push_back(D->getStorageClass());
996   Record.push_back(D->getTSCSpec());
997   Record.push_back(D->getInitStyle());
998   Record.push_back(D->isARCPseudoStrong());
999   if (!isa<ParmVarDecl>(D)) {
1000     Record.push_back(D->isThisDeclarationADemotedDefinition());
1001     Record.push_back(D->isExceptionVariable());
1002     Record.push_back(D->isNRVOVariable());
1003     Record.push_back(D->isCXXForRangeDecl());
1004     Record.push_back(D->isObjCForDecl());
1005     Record.push_back(D->isInline());
1006     Record.push_back(D->isInlineSpecified());
1007     Record.push_back(D->isConstexpr());
1008     Record.push_back(D->isInitCapture());
1009     Record.push_back(D->isPreviousDeclInSameBlockScope());
1010     if (const auto *IPD = dyn_cast<ImplicitParamDecl>(D))
1011       Record.push_back(static_cast<unsigned>(IPD->getParameterKind()));
1012     else
1013       Record.push_back(0);
1014     Record.push_back(D->isEscapingByref());
1015   }
1016   Record.push_back(D->getLinkageInternal());
1017 
1018   Record.AddVarDeclInit(D);
1019 
1020   if (D->hasAttr<BlocksAttr>() && D->getType()->getAsCXXRecordDecl()) {
1021     BlockVarCopyInit Init = Writer.Context->getBlockVarCopyInit(D);
1022     Record.AddStmt(Init.getCopyExpr());
1023     if (Init.getCopyExpr())
1024       Record.push_back(Init.canThrow());
1025   }
1026 
1027   if (D->getStorageDuration() == SD_Static) {
1028     bool ModulesCodegen = false;
1029     if (Writer.WritingModule &&
1030         !D->getDescribedVarTemplate() && !D->getMemberSpecializationInfo() &&
1031         !isa<VarTemplateSpecializationDecl>(D)) {
1032       // When building a C++20 module interface unit or a partition unit, a
1033       // strong definition in the module interface is provided by the
1034       // compilation of that unit, not by its users. (Inline variables are still
1035       // emitted in module users.)
1036       ModulesCodegen =
1037           (Writer.WritingModule->isInterfaceOrPartition() ||
1038            (D->hasAttr<DLLExportAttr>() &&
1039             Writer.Context->getLangOpts().BuildingPCHWithObjectFile)) &&
1040           Writer.Context->GetGVALinkageForVariable(D) == GVA_StrongExternal;
1041     }
1042     Record.push_back(ModulesCodegen);
1043     if (ModulesCodegen)
1044       Writer.ModularCodegenDecls.push_back(Writer.GetDeclRef(D));
1045   }
1046 
1047   enum {
1048     VarNotTemplate = 0, VarTemplate, StaticDataMemberSpecialization
1049   };
1050   if (VarTemplateDecl *TemplD = D->getDescribedVarTemplate()) {
1051     Record.push_back(VarTemplate);
1052     Record.AddDeclRef(TemplD);
1053   } else if (MemberSpecializationInfo *SpecInfo
1054                = D->getMemberSpecializationInfo()) {
1055     Record.push_back(StaticDataMemberSpecialization);
1056     Record.AddDeclRef(SpecInfo->getInstantiatedFrom());
1057     Record.push_back(SpecInfo->getTemplateSpecializationKind());
1058     Record.AddSourceLocation(SpecInfo->getPointOfInstantiation());
1059   } else {
1060     Record.push_back(VarNotTemplate);
1061   }
1062 
1063   if (D->getDeclContext() == D->getLexicalDeclContext() &&
1064       !D->hasAttrs() &&
1065       !D->isImplicit() &&
1066       !D->isUsed(false) &&
1067       !D->isInvalidDecl() &&
1068       !D->isReferenced() &&
1069       !D->isTopLevelDeclInObjCContainer() &&
1070       D->getAccess() == AS_none &&
1071       !D->isModulePrivate() &&
1072       !needsAnonymousDeclarationNumber(D) &&
1073       D->getDeclName().getNameKind() == DeclarationName::Identifier &&
1074       !D->hasExtInfo() &&
1075       D->getFirstDecl() == D->getMostRecentDecl() &&
1076       D->getKind() == Decl::Var &&
1077       !D->isInline() &&
1078       !D->isConstexpr() &&
1079       !D->isInitCapture() &&
1080       !D->isPreviousDeclInSameBlockScope() &&
1081       !(D->hasAttr<BlocksAttr>() && D->getType()->getAsCXXRecordDecl()) &&
1082       !D->isEscapingByref() &&
1083       D->getStorageDuration() != SD_Static &&
1084       !D->getMemberSpecializationInfo())
1085     AbbrevToUse = Writer.getDeclVarAbbrev();
1086 
1087   Code = serialization::DECL_VAR;
1088 }
1089 
1090 void ASTDeclWriter::VisitImplicitParamDecl(ImplicitParamDecl *D) {
1091   VisitVarDecl(D);
1092   Code = serialization::DECL_IMPLICIT_PARAM;
1093 }
1094 
1095 void ASTDeclWriter::VisitParmVarDecl(ParmVarDecl *D) {
1096   VisitVarDecl(D);
1097   Record.push_back(D->isObjCMethodParameter());
1098   Record.push_back(D->getFunctionScopeDepth());
1099   Record.push_back(D->getFunctionScopeIndex());
1100   Record.push_back(D->getObjCDeclQualifier()); // FIXME: stable encoding
1101   Record.push_back(D->isKNRPromoted());
1102   Record.push_back(D->hasInheritedDefaultArg());
1103   Record.push_back(D->hasUninstantiatedDefaultArg());
1104   if (D->hasUninstantiatedDefaultArg())
1105     Record.AddStmt(D->getUninstantiatedDefaultArg());
1106   Code = serialization::DECL_PARM_VAR;
1107 
1108   // If the assumptions about the DECL_PARM_VAR abbrev are true, use it.  Here
1109   // we dynamically check for the properties that we optimize for, but don't
1110   // know are true of all PARM_VAR_DECLs.
1111   if (D->getDeclContext() == D->getLexicalDeclContext() &&
1112       !D->hasAttrs() &&
1113       !D->hasExtInfo() &&
1114       !D->isImplicit() &&
1115       !D->isUsed(false) &&
1116       !D->isInvalidDecl() &&
1117       !D->isReferenced() &&
1118       D->getAccess() == AS_none &&
1119       !D->isModulePrivate() &&
1120       D->getStorageClass() == 0 &&
1121       D->getInitStyle() == VarDecl::CInit && // Can params have anything else?
1122       D->getFunctionScopeDepth() == 0 &&
1123       D->getObjCDeclQualifier() == 0 &&
1124       !D->isKNRPromoted() &&
1125       !D->hasInheritedDefaultArg() &&
1126       D->getInit() == nullptr &&
1127       !D->hasUninstantiatedDefaultArg())  // No default expr.
1128     AbbrevToUse = Writer.getDeclParmVarAbbrev();
1129 
1130   // Check things we know are true of *every* PARM_VAR_DECL, which is more than
1131   // just us assuming it.
1132   assert(!D->getTSCSpec() && "PARM_VAR_DECL can't use TLS");
1133   assert(!D->isThisDeclarationADemotedDefinition()
1134          && "PARM_VAR_DECL can't be demoted definition.");
1135   assert(D->getAccess() == AS_none && "PARM_VAR_DECL can't be public/private");
1136   assert(!D->isExceptionVariable() && "PARM_VAR_DECL can't be exception var");
1137   assert(D->getPreviousDecl() == nullptr && "PARM_VAR_DECL can't be redecl");
1138   assert(!D->isStaticDataMember() &&
1139          "PARM_VAR_DECL can't be static data member");
1140 }
1141 
1142 void ASTDeclWriter::VisitDecompositionDecl(DecompositionDecl *D) {
1143   // Record the number of bindings first to simplify deserialization.
1144   Record.push_back(D->bindings().size());
1145 
1146   VisitVarDecl(D);
1147   for (auto *B : D->bindings())
1148     Record.AddDeclRef(B);
1149   Code = serialization::DECL_DECOMPOSITION;
1150 }
1151 
1152 void ASTDeclWriter::VisitBindingDecl(BindingDecl *D) {
1153   VisitValueDecl(D);
1154   Record.AddStmt(D->getBinding());
1155   Code = serialization::DECL_BINDING;
1156 }
1157 
1158 void ASTDeclWriter::VisitFileScopeAsmDecl(FileScopeAsmDecl *D) {
1159   VisitDecl(D);
1160   Record.AddStmt(D->getAsmString());
1161   Record.AddSourceLocation(D->getRParenLoc());
1162   Code = serialization::DECL_FILE_SCOPE_ASM;
1163 }
1164 
1165 void ASTDeclWriter::VisitEmptyDecl(EmptyDecl *D) {
1166   VisitDecl(D);
1167   Code = serialization::DECL_EMPTY;
1168 }
1169 
1170 void ASTDeclWriter::VisitLifetimeExtendedTemporaryDecl(
1171     LifetimeExtendedTemporaryDecl *D) {
1172   VisitDecl(D);
1173   Record.AddDeclRef(D->getExtendingDecl());
1174   Record.AddStmt(D->getTemporaryExpr());
1175   Record.push_back(static_cast<bool>(D->getValue()));
1176   if (D->getValue())
1177     Record.AddAPValue(*D->getValue());
1178   Record.push_back(D->getManglingNumber());
1179   Code = serialization::DECL_LIFETIME_EXTENDED_TEMPORARY;
1180 }
1181 void ASTDeclWriter::VisitBlockDecl(BlockDecl *D) {
1182   VisitDecl(D);
1183   Record.AddStmt(D->getBody());
1184   Record.AddTypeSourceInfo(D->getSignatureAsWritten());
1185   Record.push_back(D->param_size());
1186   for (ParmVarDecl *P : D->parameters())
1187     Record.AddDeclRef(P);
1188   Record.push_back(D->isVariadic());
1189   Record.push_back(D->blockMissingReturnType());
1190   Record.push_back(D->isConversionFromLambda());
1191   Record.push_back(D->doesNotEscape());
1192   Record.push_back(D->canAvoidCopyToHeap());
1193   Record.push_back(D->capturesCXXThis());
1194   Record.push_back(D->getNumCaptures());
1195   for (const auto &capture : D->captures()) {
1196     Record.AddDeclRef(capture.getVariable());
1197 
1198     unsigned flags = 0;
1199     if (capture.isByRef()) flags |= 1;
1200     if (capture.isNested()) flags |= 2;
1201     if (capture.hasCopyExpr()) flags |= 4;
1202     Record.push_back(flags);
1203 
1204     if (capture.hasCopyExpr()) Record.AddStmt(capture.getCopyExpr());
1205   }
1206 
1207   Code = serialization::DECL_BLOCK;
1208 }
1209 
1210 void ASTDeclWriter::VisitCapturedDecl(CapturedDecl *CD) {
1211   Record.push_back(CD->getNumParams());
1212   VisitDecl(CD);
1213   Record.push_back(CD->getContextParamPosition());
1214   Record.push_back(CD->isNothrow() ? 1 : 0);
1215   // Body is stored by VisitCapturedStmt.
1216   for (unsigned I = 0; I < CD->getNumParams(); ++I)
1217     Record.AddDeclRef(CD->getParam(I));
1218   Code = serialization::DECL_CAPTURED;
1219 }
1220 
1221 void ASTDeclWriter::VisitLinkageSpecDecl(LinkageSpecDecl *D) {
1222   VisitDecl(D);
1223   Record.push_back(D->getLanguage());
1224   Record.AddSourceLocation(D->getExternLoc());
1225   Record.AddSourceLocation(D->getRBraceLoc());
1226   Code = serialization::DECL_LINKAGE_SPEC;
1227 }
1228 
1229 void ASTDeclWriter::VisitExportDecl(ExportDecl *D) {
1230   VisitDecl(D);
1231   Record.AddSourceLocation(D->getRBraceLoc());
1232   Code = serialization::DECL_EXPORT;
1233 }
1234 
1235 void ASTDeclWriter::VisitLabelDecl(LabelDecl *D) {
1236   VisitNamedDecl(D);
1237   Record.AddSourceLocation(D->getBeginLoc());
1238   Code = serialization::DECL_LABEL;
1239 }
1240 
1241 
1242 void ASTDeclWriter::VisitNamespaceDecl(NamespaceDecl *D) {
1243   VisitRedeclarable(D);
1244   VisitNamedDecl(D);
1245   Record.push_back(D->isInline());
1246   Record.AddSourceLocation(D->getBeginLoc());
1247   Record.AddSourceLocation(D->getRBraceLoc());
1248 
1249   if (D->isOriginalNamespace())
1250     Record.AddDeclRef(D->getAnonymousNamespace());
1251   Code = serialization::DECL_NAMESPACE;
1252 
1253   if (Writer.hasChain() && D->isAnonymousNamespace() &&
1254       D == D->getMostRecentDecl()) {
1255     // This is a most recent reopening of the anonymous namespace. If its parent
1256     // is in a previous PCH (or is the TU), mark that parent for update, because
1257     // the original namespace always points to the latest re-opening of its
1258     // anonymous namespace.
1259     Decl *Parent = cast<Decl>(
1260         D->getParent()->getRedeclContext()->getPrimaryContext());
1261     if (Parent->isFromASTFile() || isa<TranslationUnitDecl>(Parent)) {
1262       Writer.DeclUpdates[Parent].push_back(
1263           ASTWriter::DeclUpdate(UPD_CXX_ADDED_ANONYMOUS_NAMESPACE, D));
1264     }
1265   }
1266 }
1267 
1268 void ASTDeclWriter::VisitNamespaceAliasDecl(NamespaceAliasDecl *D) {
1269   VisitRedeclarable(D);
1270   VisitNamedDecl(D);
1271   Record.AddSourceLocation(D->getNamespaceLoc());
1272   Record.AddSourceLocation(D->getTargetNameLoc());
1273   Record.AddNestedNameSpecifierLoc(D->getQualifierLoc());
1274   Record.AddDeclRef(D->getNamespace());
1275   Code = serialization::DECL_NAMESPACE_ALIAS;
1276 }
1277 
1278 void ASTDeclWriter::VisitUsingDecl(UsingDecl *D) {
1279   VisitNamedDecl(D);
1280   Record.AddSourceLocation(D->getUsingLoc());
1281   Record.AddNestedNameSpecifierLoc(D->getQualifierLoc());
1282   Record.AddDeclarationNameLoc(D->DNLoc, D->getDeclName());
1283   Record.AddDeclRef(D->FirstUsingShadow.getPointer());
1284   Record.push_back(D->hasTypename());
1285   Record.AddDeclRef(Context.getInstantiatedFromUsingDecl(D));
1286   Code = serialization::DECL_USING;
1287 }
1288 
1289 void ASTDeclWriter::VisitUsingEnumDecl(UsingEnumDecl *D) {
1290   VisitNamedDecl(D);
1291   Record.AddSourceLocation(D->getUsingLoc());
1292   Record.AddSourceLocation(D->getEnumLoc());
1293   Record.AddDeclRef(D->getEnumDecl());
1294   Record.AddDeclRef(D->FirstUsingShadow.getPointer());
1295   Record.AddDeclRef(Context.getInstantiatedFromUsingEnumDecl(D));
1296   Code = serialization::DECL_USING_ENUM;
1297 }
1298 
1299 void ASTDeclWriter::VisitUsingPackDecl(UsingPackDecl *D) {
1300   Record.push_back(D->NumExpansions);
1301   VisitNamedDecl(D);
1302   Record.AddDeclRef(D->getInstantiatedFromUsingDecl());
1303   for (auto *E : D->expansions())
1304     Record.AddDeclRef(E);
1305   Code = serialization::DECL_USING_PACK;
1306 }
1307 
1308 void ASTDeclWriter::VisitUsingShadowDecl(UsingShadowDecl *D) {
1309   VisitRedeclarable(D);
1310   VisitNamedDecl(D);
1311   Record.AddDeclRef(D->getTargetDecl());
1312   Record.push_back(D->getIdentifierNamespace());
1313   Record.AddDeclRef(D->UsingOrNextShadow);
1314   Record.AddDeclRef(Context.getInstantiatedFromUsingShadowDecl(D));
1315   Code = serialization::DECL_USING_SHADOW;
1316 }
1317 
1318 void ASTDeclWriter::VisitConstructorUsingShadowDecl(
1319     ConstructorUsingShadowDecl *D) {
1320   VisitUsingShadowDecl(D);
1321   Record.AddDeclRef(D->NominatedBaseClassShadowDecl);
1322   Record.AddDeclRef(D->ConstructedBaseClassShadowDecl);
1323   Record.push_back(D->IsVirtual);
1324   Code = serialization::DECL_CONSTRUCTOR_USING_SHADOW;
1325 }
1326 
1327 void ASTDeclWriter::VisitUsingDirectiveDecl(UsingDirectiveDecl *D) {
1328   VisitNamedDecl(D);
1329   Record.AddSourceLocation(D->getUsingLoc());
1330   Record.AddSourceLocation(D->getNamespaceKeyLocation());
1331   Record.AddNestedNameSpecifierLoc(D->getQualifierLoc());
1332   Record.AddDeclRef(D->getNominatedNamespace());
1333   Record.AddDeclRef(dyn_cast<Decl>(D->getCommonAncestor()));
1334   Code = serialization::DECL_USING_DIRECTIVE;
1335 }
1336 
1337 void ASTDeclWriter::VisitUnresolvedUsingValueDecl(UnresolvedUsingValueDecl *D) {
1338   VisitValueDecl(D);
1339   Record.AddSourceLocation(D->getUsingLoc());
1340   Record.AddNestedNameSpecifierLoc(D->getQualifierLoc());
1341   Record.AddDeclarationNameLoc(D->DNLoc, D->getDeclName());
1342   Record.AddSourceLocation(D->getEllipsisLoc());
1343   Code = serialization::DECL_UNRESOLVED_USING_VALUE;
1344 }
1345 
1346 void ASTDeclWriter::VisitUnresolvedUsingTypenameDecl(
1347                                                UnresolvedUsingTypenameDecl *D) {
1348   VisitTypeDecl(D);
1349   Record.AddSourceLocation(D->getTypenameLoc());
1350   Record.AddNestedNameSpecifierLoc(D->getQualifierLoc());
1351   Record.AddSourceLocation(D->getEllipsisLoc());
1352   Code = serialization::DECL_UNRESOLVED_USING_TYPENAME;
1353 }
1354 
1355 void ASTDeclWriter::VisitUnresolvedUsingIfExistsDecl(
1356     UnresolvedUsingIfExistsDecl *D) {
1357   VisitNamedDecl(D);
1358   Code = serialization::DECL_UNRESOLVED_USING_IF_EXISTS;
1359 }
1360 
1361 void ASTDeclWriter::VisitCXXRecordDecl(CXXRecordDecl *D) {
1362   VisitRecordDecl(D);
1363 
1364   enum {
1365     CXXRecNotTemplate = 0, CXXRecTemplate, CXXRecMemberSpecialization
1366   };
1367   if (ClassTemplateDecl *TemplD = D->getDescribedClassTemplate()) {
1368     Record.push_back(CXXRecTemplate);
1369     Record.AddDeclRef(TemplD);
1370   } else if (MemberSpecializationInfo *MSInfo
1371                = D->getMemberSpecializationInfo()) {
1372     Record.push_back(CXXRecMemberSpecialization);
1373     Record.AddDeclRef(MSInfo->getInstantiatedFrom());
1374     Record.push_back(MSInfo->getTemplateSpecializationKind());
1375     Record.AddSourceLocation(MSInfo->getPointOfInstantiation());
1376   } else {
1377     Record.push_back(CXXRecNotTemplate);
1378   }
1379 
1380   Record.push_back(D->isThisDeclarationADefinition());
1381   if (D->isThisDeclarationADefinition())
1382     Record.AddCXXDefinitionData(D);
1383 
1384   // Store (what we currently believe to be) the key function to avoid
1385   // deserializing every method so we can compute it.
1386   if (D->isCompleteDefinition())
1387     Record.AddDeclRef(Context.getCurrentKeyFunction(D));
1388 
1389   Code = serialization::DECL_CXX_RECORD;
1390 }
1391 
1392 void ASTDeclWriter::VisitCXXMethodDecl(CXXMethodDecl *D) {
1393   VisitFunctionDecl(D);
1394   if (D->isCanonicalDecl()) {
1395     Record.push_back(D->size_overridden_methods());
1396     for (const CXXMethodDecl *MD : D->overridden_methods())
1397       Record.AddDeclRef(MD);
1398   } else {
1399     // We only need to record overridden methods once for the canonical decl.
1400     Record.push_back(0);
1401   }
1402 
1403   if (D->getDeclContext() == D->getLexicalDeclContext() &&
1404       D->getFirstDecl() == D->getMostRecentDecl() &&
1405       !D->isInvalidDecl() &&
1406       !D->hasAttrs() &&
1407       !D->isTopLevelDeclInObjCContainer() &&
1408       D->getDeclName().getNameKind() == DeclarationName::Identifier &&
1409       !D->hasExtInfo() &&
1410       !D->hasInheritedPrototype() &&
1411       D->hasWrittenPrototype())
1412     AbbrevToUse = Writer.getDeclCXXMethodAbbrev();
1413 
1414   Code = serialization::DECL_CXX_METHOD;
1415 }
1416 
1417 void ASTDeclWriter::VisitCXXConstructorDecl(CXXConstructorDecl *D) {
1418   Record.push_back(D->getTrailingAllocKind());
1419   addExplicitSpecifier(D->getExplicitSpecifier(), Record);
1420   if (auto Inherited = D->getInheritedConstructor()) {
1421     Record.AddDeclRef(Inherited.getShadowDecl());
1422     Record.AddDeclRef(Inherited.getConstructor());
1423   }
1424 
1425   VisitCXXMethodDecl(D);
1426   Code = serialization::DECL_CXX_CONSTRUCTOR;
1427 }
1428 
1429 void ASTDeclWriter::VisitCXXDestructorDecl(CXXDestructorDecl *D) {
1430   VisitCXXMethodDecl(D);
1431 
1432   Record.AddDeclRef(D->getOperatorDelete());
1433   if (D->getOperatorDelete())
1434     Record.AddStmt(D->getOperatorDeleteThisArg());
1435 
1436   Code = serialization::DECL_CXX_DESTRUCTOR;
1437 }
1438 
1439 void ASTDeclWriter::VisitCXXConversionDecl(CXXConversionDecl *D) {
1440   addExplicitSpecifier(D->getExplicitSpecifier(), Record);
1441   VisitCXXMethodDecl(D);
1442   Code = serialization::DECL_CXX_CONVERSION;
1443 }
1444 
1445 void ASTDeclWriter::VisitImportDecl(ImportDecl *D) {
1446   VisitDecl(D);
1447   Record.push_back(Writer.getSubmoduleID(D->getImportedModule()));
1448   ArrayRef<SourceLocation> IdentifierLocs = D->getIdentifierLocs();
1449   Record.push_back(!IdentifierLocs.empty());
1450   if (IdentifierLocs.empty()) {
1451     Record.AddSourceLocation(D->getEndLoc());
1452     Record.push_back(1);
1453   } else {
1454     for (unsigned I = 0, N = IdentifierLocs.size(); I != N; ++I)
1455       Record.AddSourceLocation(IdentifierLocs[I]);
1456     Record.push_back(IdentifierLocs.size());
1457   }
1458   // Note: the number of source locations must always be the last element in
1459   // the record.
1460   Code = serialization::DECL_IMPORT;
1461 }
1462 
1463 void ASTDeclWriter::VisitAccessSpecDecl(AccessSpecDecl *D) {
1464   VisitDecl(D);
1465   Record.AddSourceLocation(D->getColonLoc());
1466   Code = serialization::DECL_ACCESS_SPEC;
1467 }
1468 
1469 void ASTDeclWriter::VisitFriendDecl(FriendDecl *D) {
1470   // Record the number of friend type template parameter lists here
1471   // so as to simplify memory allocation during deserialization.
1472   Record.push_back(D->NumTPLists);
1473   VisitDecl(D);
1474   bool hasFriendDecl = D->Friend.is<NamedDecl*>();
1475   Record.push_back(hasFriendDecl);
1476   if (hasFriendDecl)
1477     Record.AddDeclRef(D->getFriendDecl());
1478   else
1479     Record.AddTypeSourceInfo(D->getFriendType());
1480   for (unsigned i = 0; i < D->NumTPLists; ++i)
1481     Record.AddTemplateParameterList(D->getFriendTypeTemplateParameterList(i));
1482   Record.AddDeclRef(D->getNextFriend());
1483   Record.push_back(D->UnsupportedFriend);
1484   Record.AddSourceLocation(D->FriendLoc);
1485   Code = serialization::DECL_FRIEND;
1486 }
1487 
1488 void ASTDeclWriter::VisitFriendTemplateDecl(FriendTemplateDecl *D) {
1489   VisitDecl(D);
1490   Record.push_back(D->getNumTemplateParameters());
1491   for (unsigned i = 0, e = D->getNumTemplateParameters(); i != e; ++i)
1492     Record.AddTemplateParameterList(D->getTemplateParameterList(i));
1493   Record.push_back(D->getFriendDecl() != nullptr);
1494   if (D->getFriendDecl())
1495     Record.AddDeclRef(D->getFriendDecl());
1496   else
1497     Record.AddTypeSourceInfo(D->getFriendType());
1498   Record.AddSourceLocation(D->getFriendLoc());
1499   Code = serialization::DECL_FRIEND_TEMPLATE;
1500 }
1501 
1502 void ASTDeclWriter::VisitTemplateDecl(TemplateDecl *D) {
1503   VisitNamedDecl(D);
1504 
1505   Record.AddDeclRef(D->getTemplatedDecl());
1506   Record.AddTemplateParameterList(D->getTemplateParameters());
1507 }
1508 
1509 void ASTDeclWriter::VisitConceptDecl(ConceptDecl *D) {
1510   VisitTemplateDecl(D);
1511   Record.AddStmt(D->getConstraintExpr());
1512   Code = serialization::DECL_CONCEPT;
1513 }
1514 
1515 void ASTDeclWriter::VisitRequiresExprBodyDecl(RequiresExprBodyDecl *D) {
1516   Code = serialization::DECL_REQUIRES_EXPR_BODY;
1517 }
1518 
1519 void ASTDeclWriter::VisitRedeclarableTemplateDecl(RedeclarableTemplateDecl *D) {
1520   VisitRedeclarable(D);
1521 
1522   // Emit data to initialize CommonOrPrev before VisitTemplateDecl so that
1523   // getCommonPtr() can be used while this is still initializing.
1524   if (D->isFirstDecl()) {
1525     // This declaration owns the 'common' pointer, so serialize that data now.
1526     Record.AddDeclRef(D->getInstantiatedFromMemberTemplate());
1527     if (D->getInstantiatedFromMemberTemplate())
1528       Record.push_back(D->isMemberSpecialization());
1529   }
1530 
1531   VisitTemplateDecl(D);
1532   Record.push_back(D->getIdentifierNamespace());
1533 }
1534 
1535 void ASTDeclWriter::VisitClassTemplateDecl(ClassTemplateDecl *D) {
1536   VisitRedeclarableTemplateDecl(D);
1537 
1538   if (D->isFirstDecl())
1539     AddTemplateSpecializations(D);
1540   Code = serialization::DECL_CLASS_TEMPLATE;
1541 }
1542 
1543 void ASTDeclWriter::VisitClassTemplateSpecializationDecl(
1544                                            ClassTemplateSpecializationDecl *D) {
1545   RegisterTemplateSpecialization(D->getSpecializedTemplate(), D);
1546 
1547   VisitCXXRecordDecl(D);
1548 
1549   llvm::PointerUnion<ClassTemplateDecl *,
1550                      ClassTemplatePartialSpecializationDecl *> InstFrom
1551     = D->getSpecializedTemplateOrPartial();
1552   if (Decl *InstFromD = InstFrom.dyn_cast<ClassTemplateDecl *>()) {
1553     Record.AddDeclRef(InstFromD);
1554   } else {
1555     Record.AddDeclRef(InstFrom.get<ClassTemplatePartialSpecializationDecl *>());
1556     Record.AddTemplateArgumentList(&D->getTemplateInstantiationArgs());
1557   }
1558 
1559   Record.AddTemplateArgumentList(&D->getTemplateArgs());
1560   Record.AddSourceLocation(D->getPointOfInstantiation());
1561   Record.push_back(D->getSpecializationKind());
1562   Record.push_back(D->isCanonicalDecl());
1563 
1564   if (D->isCanonicalDecl()) {
1565     // When reading, we'll add it to the folding set of the following template.
1566     Record.AddDeclRef(D->getSpecializedTemplate()->getCanonicalDecl());
1567   }
1568 
1569   // Explicit info.
1570   Record.AddTypeSourceInfo(D->getTypeAsWritten());
1571   if (D->getTypeAsWritten()) {
1572     Record.AddSourceLocation(D->getExternLoc());
1573     Record.AddSourceLocation(D->getTemplateKeywordLoc());
1574   }
1575 
1576   Code = serialization::DECL_CLASS_TEMPLATE_SPECIALIZATION;
1577 }
1578 
1579 void ASTDeclWriter::VisitClassTemplatePartialSpecializationDecl(
1580                                     ClassTemplatePartialSpecializationDecl *D) {
1581   Record.AddTemplateParameterList(D->getTemplateParameters());
1582   Record.AddASTTemplateArgumentListInfo(D->getTemplateArgsAsWritten());
1583 
1584   VisitClassTemplateSpecializationDecl(D);
1585 
1586   // These are read/set from/to the first declaration.
1587   if (D->getPreviousDecl() == nullptr) {
1588     Record.AddDeclRef(D->getInstantiatedFromMember());
1589     Record.push_back(D->isMemberSpecialization());
1590   }
1591 
1592   Code = serialization::DECL_CLASS_TEMPLATE_PARTIAL_SPECIALIZATION;
1593 }
1594 
1595 void ASTDeclWriter::VisitVarTemplateDecl(VarTemplateDecl *D) {
1596   VisitRedeclarableTemplateDecl(D);
1597 
1598   if (D->isFirstDecl())
1599     AddTemplateSpecializations(D);
1600   Code = serialization::DECL_VAR_TEMPLATE;
1601 }
1602 
1603 void ASTDeclWriter::VisitVarTemplateSpecializationDecl(
1604     VarTemplateSpecializationDecl *D) {
1605   RegisterTemplateSpecialization(D->getSpecializedTemplate(), D);
1606 
1607   VisitVarDecl(D);
1608 
1609   llvm::PointerUnion<VarTemplateDecl *, VarTemplatePartialSpecializationDecl *>
1610   InstFrom = D->getSpecializedTemplateOrPartial();
1611   if (Decl *InstFromD = InstFrom.dyn_cast<VarTemplateDecl *>()) {
1612     Record.AddDeclRef(InstFromD);
1613   } else {
1614     Record.AddDeclRef(InstFrom.get<VarTemplatePartialSpecializationDecl *>());
1615     Record.AddTemplateArgumentList(&D->getTemplateInstantiationArgs());
1616   }
1617 
1618   // Explicit info.
1619   Record.AddTypeSourceInfo(D->getTypeAsWritten());
1620   if (D->getTypeAsWritten()) {
1621     Record.AddSourceLocation(D->getExternLoc());
1622     Record.AddSourceLocation(D->getTemplateKeywordLoc());
1623   }
1624 
1625   Record.AddTemplateArgumentList(&D->getTemplateArgs());
1626   Record.AddSourceLocation(D->getPointOfInstantiation());
1627   Record.push_back(D->getSpecializationKind());
1628   Record.push_back(D->IsCompleteDefinition);
1629   Record.push_back(D->isCanonicalDecl());
1630 
1631   if (D->isCanonicalDecl()) {
1632     // When reading, we'll add it to the folding set of the following template.
1633     Record.AddDeclRef(D->getSpecializedTemplate()->getCanonicalDecl());
1634   }
1635 
1636   Code = serialization::DECL_VAR_TEMPLATE_SPECIALIZATION;
1637 }
1638 
1639 void ASTDeclWriter::VisitVarTemplatePartialSpecializationDecl(
1640     VarTemplatePartialSpecializationDecl *D) {
1641   Record.AddTemplateParameterList(D->getTemplateParameters());
1642   Record.AddASTTemplateArgumentListInfo(D->getTemplateArgsAsWritten());
1643 
1644   VisitVarTemplateSpecializationDecl(D);
1645 
1646   // These are read/set from/to the first declaration.
1647   if (D->getPreviousDecl() == nullptr) {
1648     Record.AddDeclRef(D->getInstantiatedFromMember());
1649     Record.push_back(D->isMemberSpecialization());
1650   }
1651 
1652   Code = serialization::DECL_VAR_TEMPLATE_PARTIAL_SPECIALIZATION;
1653 }
1654 
1655 void ASTDeclWriter::VisitClassScopeFunctionSpecializationDecl(
1656                                     ClassScopeFunctionSpecializationDecl *D) {
1657   VisitDecl(D);
1658   Record.AddDeclRef(D->getSpecialization());
1659   Record.push_back(D->hasExplicitTemplateArgs());
1660   if (D->hasExplicitTemplateArgs())
1661     Record.AddASTTemplateArgumentListInfo(D->getTemplateArgsAsWritten());
1662   Code = serialization::DECL_CLASS_SCOPE_FUNCTION_SPECIALIZATION;
1663 }
1664 
1665 
1666 void ASTDeclWriter::VisitFunctionTemplateDecl(FunctionTemplateDecl *D) {
1667   VisitRedeclarableTemplateDecl(D);
1668 
1669   if (D->isFirstDecl())
1670     AddTemplateSpecializations(D);
1671   Code = serialization::DECL_FUNCTION_TEMPLATE;
1672 }
1673 
1674 void ASTDeclWriter::VisitTemplateTypeParmDecl(TemplateTypeParmDecl *D) {
1675   Record.push_back(D->hasTypeConstraint());
1676   VisitTypeDecl(D);
1677 
1678   Record.push_back(D->wasDeclaredWithTypename());
1679 
1680   const TypeConstraint *TC = D->getTypeConstraint();
1681   Record.push_back(TC != nullptr);
1682   if (TC) {
1683     Record.AddNestedNameSpecifierLoc(TC->getNestedNameSpecifierLoc());
1684     Record.AddDeclarationNameInfo(TC->getConceptNameInfo());
1685     Record.AddDeclRef(TC->getNamedConcept());
1686     Record.push_back(TC->getTemplateArgsAsWritten() != nullptr);
1687     if (TC->getTemplateArgsAsWritten())
1688       Record.AddASTTemplateArgumentListInfo(TC->getTemplateArgsAsWritten());
1689     Record.AddStmt(TC->getImmediatelyDeclaredConstraint());
1690     Record.push_back(D->isExpandedParameterPack());
1691     if (D->isExpandedParameterPack())
1692       Record.push_back(D->getNumExpansionParameters());
1693   }
1694 
1695   bool OwnsDefaultArg = D->hasDefaultArgument() &&
1696                         !D->defaultArgumentWasInherited();
1697   Record.push_back(OwnsDefaultArg);
1698   if (OwnsDefaultArg)
1699     Record.AddTypeSourceInfo(D->getDefaultArgumentInfo());
1700 
1701   Code = serialization::DECL_TEMPLATE_TYPE_PARM;
1702 }
1703 
1704 void ASTDeclWriter::VisitNonTypeTemplateParmDecl(NonTypeTemplateParmDecl *D) {
1705   // For an expanded parameter pack, record the number of expansion types here
1706   // so that it's easier for deserialization to allocate the right amount of
1707   // memory.
1708   Expr *TypeConstraint = D->getPlaceholderTypeConstraint();
1709   Record.push_back(!!TypeConstraint);
1710   if (D->isExpandedParameterPack())
1711     Record.push_back(D->getNumExpansionTypes());
1712 
1713   VisitDeclaratorDecl(D);
1714   // TemplateParmPosition.
1715   Record.push_back(D->getDepth());
1716   Record.push_back(D->getPosition());
1717   if (TypeConstraint)
1718     Record.AddStmt(TypeConstraint);
1719 
1720   if (D->isExpandedParameterPack()) {
1721     for (unsigned I = 0, N = D->getNumExpansionTypes(); I != N; ++I) {
1722       Record.AddTypeRef(D->getExpansionType(I));
1723       Record.AddTypeSourceInfo(D->getExpansionTypeSourceInfo(I));
1724     }
1725 
1726     Code = serialization::DECL_EXPANDED_NON_TYPE_TEMPLATE_PARM_PACK;
1727   } else {
1728     // Rest of NonTypeTemplateParmDecl.
1729     Record.push_back(D->isParameterPack());
1730     bool OwnsDefaultArg = D->hasDefaultArgument() &&
1731                           !D->defaultArgumentWasInherited();
1732     Record.push_back(OwnsDefaultArg);
1733     if (OwnsDefaultArg)
1734       Record.AddStmt(D->getDefaultArgument());
1735     Code = serialization::DECL_NON_TYPE_TEMPLATE_PARM;
1736   }
1737 }
1738 
1739 void ASTDeclWriter::VisitTemplateTemplateParmDecl(TemplateTemplateParmDecl *D) {
1740   // For an expanded parameter pack, record the number of expansion types here
1741   // so that it's easier for deserialization to allocate the right amount of
1742   // memory.
1743   if (D->isExpandedParameterPack())
1744     Record.push_back(D->getNumExpansionTemplateParameters());
1745 
1746   VisitTemplateDecl(D);
1747   // TemplateParmPosition.
1748   Record.push_back(D->getDepth());
1749   Record.push_back(D->getPosition());
1750 
1751   if (D->isExpandedParameterPack()) {
1752     for (unsigned I = 0, N = D->getNumExpansionTemplateParameters();
1753          I != N; ++I)
1754       Record.AddTemplateParameterList(D->getExpansionTemplateParameters(I));
1755     Code = serialization::DECL_EXPANDED_TEMPLATE_TEMPLATE_PARM_PACK;
1756   } else {
1757     // Rest of TemplateTemplateParmDecl.
1758     Record.push_back(D->isParameterPack());
1759     bool OwnsDefaultArg = D->hasDefaultArgument() &&
1760                           !D->defaultArgumentWasInherited();
1761     Record.push_back(OwnsDefaultArg);
1762     if (OwnsDefaultArg)
1763       Record.AddTemplateArgumentLoc(D->getDefaultArgument());
1764     Code = serialization::DECL_TEMPLATE_TEMPLATE_PARM;
1765   }
1766 }
1767 
1768 void ASTDeclWriter::VisitTypeAliasTemplateDecl(TypeAliasTemplateDecl *D) {
1769   VisitRedeclarableTemplateDecl(D);
1770   Code = serialization::DECL_TYPE_ALIAS_TEMPLATE;
1771 }
1772 
1773 void ASTDeclWriter::VisitStaticAssertDecl(StaticAssertDecl *D) {
1774   VisitDecl(D);
1775   Record.AddStmt(D->getAssertExpr());
1776   Record.push_back(D->isFailed());
1777   Record.AddStmt(D->getMessage());
1778   Record.AddSourceLocation(D->getRParenLoc());
1779   Code = serialization::DECL_STATIC_ASSERT;
1780 }
1781 
1782 /// Emit the DeclContext part of a declaration context decl.
1783 void ASTDeclWriter::VisitDeclContext(DeclContext *DC) {
1784   Record.AddOffset(Writer.WriteDeclContextLexicalBlock(Context, DC));
1785   Record.AddOffset(Writer.WriteDeclContextVisibleBlock(Context, DC));
1786 }
1787 
1788 const Decl *ASTWriter::getFirstLocalDecl(const Decl *D) {
1789   assert(IsLocalDecl(D) && "expected a local declaration");
1790 
1791   const Decl *Canon = D->getCanonicalDecl();
1792   if (IsLocalDecl(Canon))
1793     return Canon;
1794 
1795   const Decl *&CacheEntry = FirstLocalDeclCache[Canon];
1796   if (CacheEntry)
1797     return CacheEntry;
1798 
1799   for (const Decl *Redecl = D; Redecl; Redecl = Redecl->getPreviousDecl())
1800     if (IsLocalDecl(Redecl))
1801       D = Redecl;
1802   return CacheEntry = D;
1803 }
1804 
1805 template <typename T>
1806 void ASTDeclWriter::VisitRedeclarable(Redeclarable<T> *D) {
1807   T *First = D->getFirstDecl();
1808   T *MostRecent = First->getMostRecentDecl();
1809   T *DAsT = static_cast<T *>(D);
1810   if (MostRecent != First) {
1811     assert(isRedeclarableDeclKind(DAsT->getKind()) &&
1812            "Not considered redeclarable?");
1813 
1814     Record.AddDeclRef(First);
1815 
1816     // Write out a list of local redeclarations of this declaration if it's the
1817     // first local declaration in the chain.
1818     const Decl *FirstLocal = Writer.getFirstLocalDecl(DAsT);
1819     if (DAsT == FirstLocal) {
1820       // Emit a list of all imported first declarations so that we can be sure
1821       // that all redeclarations visible to this module are before D in the
1822       // redecl chain.
1823       unsigned I = Record.size();
1824       Record.push_back(0);
1825       if (Writer.Chain)
1826         AddFirstDeclFromEachModule(DAsT, /*IncludeLocal*/false);
1827       // This is the number of imported first declarations + 1.
1828       Record[I] = Record.size() - I;
1829 
1830       // Collect the set of local redeclarations of this declaration, from
1831       // newest to oldest.
1832       ASTWriter::RecordData LocalRedecls;
1833       ASTRecordWriter LocalRedeclWriter(Record, LocalRedecls);
1834       for (const Decl *Prev = FirstLocal->getMostRecentDecl();
1835            Prev != FirstLocal; Prev = Prev->getPreviousDecl())
1836         if (!Prev->isFromASTFile())
1837           LocalRedeclWriter.AddDeclRef(Prev);
1838 
1839       // If we have any redecls, write them now as a separate record preceding
1840       // the declaration itself.
1841       if (LocalRedecls.empty())
1842         Record.push_back(0);
1843       else
1844         Record.AddOffset(LocalRedeclWriter.Emit(LOCAL_REDECLARATIONS));
1845     } else {
1846       Record.push_back(0);
1847       Record.AddDeclRef(FirstLocal);
1848     }
1849 
1850     // Make sure that we serialize both the previous and the most-recent
1851     // declarations, which (transitively) ensures that all declarations in the
1852     // chain get serialized.
1853     //
1854     // FIXME: This is not correct; when we reach an imported declaration we
1855     // won't emit its previous declaration.
1856     (void)Writer.GetDeclRef(D->getPreviousDecl());
1857     (void)Writer.GetDeclRef(MostRecent);
1858   } else {
1859     // We use the sentinel value 0 to indicate an only declaration.
1860     Record.push_back(0);
1861   }
1862 }
1863 
1864 void ASTDeclWriter::VisitOMPThreadPrivateDecl(OMPThreadPrivateDecl *D) {
1865   Record.writeOMPChildren(D->Data);
1866   VisitDecl(D);
1867   Code = serialization::DECL_OMP_THREADPRIVATE;
1868 }
1869 
1870 void ASTDeclWriter::VisitOMPAllocateDecl(OMPAllocateDecl *D) {
1871   Record.writeOMPChildren(D->Data);
1872   VisitDecl(D);
1873   Code = serialization::DECL_OMP_ALLOCATE;
1874 }
1875 
1876 void ASTDeclWriter::VisitOMPRequiresDecl(OMPRequiresDecl *D) {
1877   Record.writeOMPChildren(D->Data);
1878   VisitDecl(D);
1879   Code = serialization::DECL_OMP_REQUIRES;
1880 }
1881 
1882 void ASTDeclWriter::VisitOMPDeclareReductionDecl(OMPDeclareReductionDecl *D) {
1883   VisitValueDecl(D);
1884   Record.AddSourceLocation(D->getBeginLoc());
1885   Record.AddStmt(D->getCombinerIn());
1886   Record.AddStmt(D->getCombinerOut());
1887   Record.AddStmt(D->getCombiner());
1888   Record.AddStmt(D->getInitOrig());
1889   Record.AddStmt(D->getInitPriv());
1890   Record.AddStmt(D->getInitializer());
1891   Record.push_back(D->getInitializerKind());
1892   Record.AddDeclRef(D->getPrevDeclInScope());
1893   Code = serialization::DECL_OMP_DECLARE_REDUCTION;
1894 }
1895 
1896 void ASTDeclWriter::VisitOMPDeclareMapperDecl(OMPDeclareMapperDecl *D) {
1897   Record.writeOMPChildren(D->Data);
1898   VisitValueDecl(D);
1899   Record.AddDeclarationName(D->getVarName());
1900   Record.AddDeclRef(D->getPrevDeclInScope());
1901   Code = serialization::DECL_OMP_DECLARE_MAPPER;
1902 }
1903 
1904 void ASTDeclWriter::VisitOMPCapturedExprDecl(OMPCapturedExprDecl *D) {
1905   VisitVarDecl(D);
1906   Code = serialization::DECL_OMP_CAPTUREDEXPR;
1907 }
1908 
1909 //===----------------------------------------------------------------------===//
1910 // ASTWriter Implementation
1911 //===----------------------------------------------------------------------===//
1912 
1913 void ASTWriter::WriteDeclAbbrevs() {
1914   using namespace llvm;
1915 
1916   std::shared_ptr<BitCodeAbbrev> Abv;
1917 
1918   // Abbreviation for DECL_FIELD
1919   Abv = std::make_shared<BitCodeAbbrev>();
1920   Abv->Add(BitCodeAbbrevOp(serialization::DECL_FIELD));
1921   // Decl
1922   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclContext
1923   Abv->Add(BitCodeAbbrevOp(0));                       // LexicalDeclContext
1924   Abv->Add(BitCodeAbbrevOp(0));                       // isInvalidDecl
1925   Abv->Add(BitCodeAbbrevOp(0));                       // HasAttrs
1926   Abv->Add(BitCodeAbbrevOp(0));                       // isImplicit
1927   Abv->Add(BitCodeAbbrevOp(0));                       // isUsed
1928   Abv->Add(BitCodeAbbrevOp(0));                       // isReferenced
1929   Abv->Add(BitCodeAbbrevOp(0));                   // TopLevelDeclInObjCContainer
1930   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2));  // AccessSpecifier
1931   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3));  // ModuleOwnershipKind
1932   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // SubmoduleID
1933   // NamedDecl
1934   Abv->Add(BitCodeAbbrevOp(0));                       // NameKind = Identifier
1935   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Name
1936   Abv->Add(BitCodeAbbrevOp(0));                       // AnonDeclNumber
1937   // ValueDecl
1938   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
1939   // DeclaratorDecl
1940   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // InnerStartLoc
1941   Abv->Add(BitCodeAbbrevOp(0));                       // hasExtInfo
1942   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // TSIType
1943   // FieldDecl
1944   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isMutable
1945   Abv->Add(BitCodeAbbrevOp(0));                       // InitStyle
1946   // Type Source Info
1947   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1948   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // TypeLoc
1949   DeclFieldAbbrev = Stream.EmitAbbrev(std::move(Abv));
1950 
1951   // Abbreviation for DECL_OBJC_IVAR
1952   Abv = std::make_shared<BitCodeAbbrev>();
1953   Abv->Add(BitCodeAbbrevOp(serialization::DECL_OBJC_IVAR));
1954   // Decl
1955   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclContext
1956   Abv->Add(BitCodeAbbrevOp(0));                       // LexicalDeclContext
1957   Abv->Add(BitCodeAbbrevOp(0));                       // isInvalidDecl
1958   Abv->Add(BitCodeAbbrevOp(0));                       // HasAttrs
1959   Abv->Add(BitCodeAbbrevOp(0));                       // isImplicit
1960   Abv->Add(BitCodeAbbrevOp(0));                       // isUsed
1961   Abv->Add(BitCodeAbbrevOp(0));                       // isReferenced
1962   Abv->Add(BitCodeAbbrevOp(0));                   // TopLevelDeclInObjCContainer
1963   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2));  // AccessSpecifier
1964   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3));  // ModuleOwnershipKind
1965   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // SubmoduleID
1966   // NamedDecl
1967   Abv->Add(BitCodeAbbrevOp(0));                       // NameKind = Identifier
1968   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Name
1969   Abv->Add(BitCodeAbbrevOp(0));                       // AnonDeclNumber
1970   // ValueDecl
1971   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
1972   // DeclaratorDecl
1973   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // InnerStartLoc
1974   Abv->Add(BitCodeAbbrevOp(0));                       // hasExtInfo
1975   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // TSIType
1976   // FieldDecl
1977   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isMutable
1978   Abv->Add(BitCodeAbbrevOp(0));                       // InitStyle
1979   // ObjC Ivar
1980   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // getAccessControl
1981   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // getSynthesize
1982   // Type Source Info
1983   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1984   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // TypeLoc
1985   DeclObjCIvarAbbrev = Stream.EmitAbbrev(std::move(Abv));
1986 
1987   // Abbreviation for DECL_ENUM
1988   Abv = std::make_shared<BitCodeAbbrev>();
1989   Abv->Add(BitCodeAbbrevOp(serialization::DECL_ENUM));
1990   // Redeclarable
1991   Abv->Add(BitCodeAbbrevOp(0));                       // No redeclaration
1992   // Decl
1993   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclContext
1994   Abv->Add(BitCodeAbbrevOp(0));                       // LexicalDeclContext
1995   Abv->Add(BitCodeAbbrevOp(0));                       // isInvalidDecl
1996   Abv->Add(BitCodeAbbrevOp(0));                       // HasAttrs
1997   Abv->Add(BitCodeAbbrevOp(0));                       // isImplicit
1998   Abv->Add(BitCodeAbbrevOp(0));                       // isUsed
1999   Abv->Add(BitCodeAbbrevOp(0));                       // isReferenced
2000   Abv->Add(BitCodeAbbrevOp(0));                   // TopLevelDeclInObjCContainer
2001   Abv->Add(BitCodeAbbrevOp(AS_none));                 // C++ AccessSpecifier
2002   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); // ModuleOwnershipKind
2003   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // SubmoduleID
2004   // NamedDecl
2005   Abv->Add(BitCodeAbbrevOp(0));                       // NameKind = Identifier
2006   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Name
2007   Abv->Add(BitCodeAbbrevOp(0));                       // AnonDeclNumber
2008   // TypeDecl
2009   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Source Location
2010   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type Ref
2011   // TagDecl
2012   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // IdentifierNamespace
2013   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // getTagKind
2014   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isCompleteDefinition
2015   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // EmbeddedInDeclarator
2016   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsFreeStanding
2017   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsCompleteDefinitionRequired
2018   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // SourceLocation
2019   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // SourceLocation
2020   Abv->Add(BitCodeAbbrevOp(0));                         // ExtInfoKind
2021   // EnumDecl
2022   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // AddTypeRef
2023   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // IntegerType
2024   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // getPromotionType
2025   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // getNumPositiveBits
2026   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // getNumNegativeBits
2027   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isScoped
2028   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isScopedUsingClassTag
2029   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isFixed
2030   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));// ODRHash
2031   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // InstantiatedMembEnum
2032   // DC
2033   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // LexicalOffset
2034   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // VisibleOffset
2035   DeclEnumAbbrev = Stream.EmitAbbrev(std::move(Abv));
2036 
2037   // Abbreviation for DECL_RECORD
2038   Abv = std::make_shared<BitCodeAbbrev>();
2039   Abv->Add(BitCodeAbbrevOp(serialization::DECL_RECORD));
2040   // Redeclarable
2041   Abv->Add(BitCodeAbbrevOp(0));                       // No redeclaration
2042   // Decl
2043   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclContext
2044   Abv->Add(BitCodeAbbrevOp(0));                       // LexicalDeclContext
2045   Abv->Add(BitCodeAbbrevOp(0));                       // isInvalidDecl
2046   Abv->Add(BitCodeAbbrevOp(0));                       // HasAttrs
2047   Abv->Add(BitCodeAbbrevOp(0));                       // isImplicit
2048   Abv->Add(BitCodeAbbrevOp(0));                       // isUsed
2049   Abv->Add(BitCodeAbbrevOp(0));                       // isReferenced
2050   Abv->Add(BitCodeAbbrevOp(0));                   // TopLevelDeclInObjCContainer
2051   Abv->Add(BitCodeAbbrevOp(AS_none));                 // C++ AccessSpecifier
2052   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); // ModuleOwnershipKind
2053   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // SubmoduleID
2054   // NamedDecl
2055   Abv->Add(BitCodeAbbrevOp(0));                       // NameKind = Identifier
2056   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Name
2057   Abv->Add(BitCodeAbbrevOp(0));                       // AnonDeclNumber
2058   // TypeDecl
2059   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Source Location
2060   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type Ref
2061   // TagDecl
2062   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // IdentifierNamespace
2063   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // getTagKind
2064   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isCompleteDefinition
2065   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // EmbeddedInDeclarator
2066   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsFreeStanding
2067   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsCompleteDefinitionRequired
2068   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // SourceLocation
2069   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // SourceLocation
2070   Abv->Add(BitCodeAbbrevOp(0));                         // ExtInfoKind
2071   // RecordDecl
2072   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // FlexibleArrayMember
2073   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // AnonymousStructUnion
2074   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // hasObjectMember
2075   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // hasVolatileMember
2076 
2077   // isNonTrivialToPrimitiveDefaultInitialize
2078   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
2079   // isNonTrivialToPrimitiveCopy
2080   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
2081   // isNonTrivialToPrimitiveDestroy
2082   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
2083   // hasNonTrivialToPrimitiveDefaultInitializeCUnion
2084   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
2085   // hasNonTrivialToPrimitiveDestructCUnion
2086   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
2087   // hasNonTrivialToPrimitiveCopyCUnion
2088   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
2089   // isParamDestroyedInCallee
2090   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
2091   // getArgPassingRestrictions
2092   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2));
2093 
2094   // DC
2095   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // LexicalOffset
2096   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // VisibleOffset
2097   DeclRecordAbbrev = Stream.EmitAbbrev(std::move(Abv));
2098 
2099   // Abbreviation for DECL_PARM_VAR
2100   Abv = std::make_shared<BitCodeAbbrev>();
2101   Abv->Add(BitCodeAbbrevOp(serialization::DECL_PARM_VAR));
2102   // Redeclarable
2103   Abv->Add(BitCodeAbbrevOp(0));                       // No redeclaration
2104   // Decl
2105   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclContext
2106   Abv->Add(BitCodeAbbrevOp(0));                       // LexicalDeclContext
2107   Abv->Add(BitCodeAbbrevOp(0));                       // isInvalidDecl
2108   Abv->Add(BitCodeAbbrevOp(0));                       // HasAttrs
2109   Abv->Add(BitCodeAbbrevOp(0));                       // isImplicit
2110   Abv->Add(BitCodeAbbrevOp(0));                       // isUsed
2111   Abv->Add(BitCodeAbbrevOp(0));                       // isReferenced
2112   Abv->Add(BitCodeAbbrevOp(0));                   // TopLevelDeclInObjCContainer
2113   Abv->Add(BitCodeAbbrevOp(AS_none));                 // C++ AccessSpecifier
2114   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); // ModuleOwnershipKind
2115   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // SubmoduleID
2116   // NamedDecl
2117   Abv->Add(BitCodeAbbrevOp(0));                       // NameKind = Identifier
2118   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Name
2119   Abv->Add(BitCodeAbbrevOp(0));                       // AnonDeclNumber
2120   // ValueDecl
2121   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
2122   // DeclaratorDecl
2123   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // InnerStartLoc
2124   Abv->Add(BitCodeAbbrevOp(0));                       // hasExtInfo
2125   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // TSIType
2126   // VarDecl
2127   Abv->Add(BitCodeAbbrevOp(0));                       // SClass
2128   Abv->Add(BitCodeAbbrevOp(0));                       // TSCSpec
2129   Abv->Add(BitCodeAbbrevOp(0));                       // InitStyle
2130   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isARCPseudoStrong
2131   Abv->Add(BitCodeAbbrevOp(0));                       // Linkage
2132   Abv->Add(BitCodeAbbrevOp(0));                       // HasInit
2133   Abv->Add(BitCodeAbbrevOp(0));                   // HasMemberSpecializationInfo
2134   // ParmVarDecl
2135   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsObjCMethodParameter
2136   Abv->Add(BitCodeAbbrevOp(0));                       // ScopeDepth
2137   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // ScopeIndex
2138   Abv->Add(BitCodeAbbrevOp(0));                       // ObjCDeclQualifier
2139   Abv->Add(BitCodeAbbrevOp(0));                       // KNRPromoted
2140   Abv->Add(BitCodeAbbrevOp(0));                       // HasInheritedDefaultArg
2141   Abv->Add(BitCodeAbbrevOp(0));                   // HasUninstantiatedDefaultArg
2142   // Type Source Info
2143   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2144   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // TypeLoc
2145   DeclParmVarAbbrev = Stream.EmitAbbrev(std::move(Abv));
2146 
2147   // Abbreviation for DECL_TYPEDEF
2148   Abv = std::make_shared<BitCodeAbbrev>();
2149   Abv->Add(BitCodeAbbrevOp(serialization::DECL_TYPEDEF));
2150   // Redeclarable
2151   Abv->Add(BitCodeAbbrevOp(0));                       // No redeclaration
2152   // Decl
2153   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclContext
2154   Abv->Add(BitCodeAbbrevOp(0));                       // LexicalDeclContext
2155   Abv->Add(BitCodeAbbrevOp(0));                       // isInvalidDecl
2156   Abv->Add(BitCodeAbbrevOp(0));                       // HasAttrs
2157   Abv->Add(BitCodeAbbrevOp(0));                       // isImplicit
2158   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isUsed
2159   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isReferenced
2160   Abv->Add(BitCodeAbbrevOp(0));                   // TopLevelDeclInObjCContainer
2161   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2)); // C++ AccessSpecifier
2162   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); // ModuleOwnershipKind
2163   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // SubmoduleID
2164   // NamedDecl
2165   Abv->Add(BitCodeAbbrevOp(0));                       // NameKind = Identifier
2166   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Name
2167   Abv->Add(BitCodeAbbrevOp(0));                       // AnonDeclNumber
2168   // TypeDecl
2169   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Source Location
2170   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type Ref
2171   // TypedefDecl
2172   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2173   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // TypeLoc
2174   DeclTypedefAbbrev = Stream.EmitAbbrev(std::move(Abv));
2175 
2176   // Abbreviation for DECL_VAR
2177   Abv = std::make_shared<BitCodeAbbrev>();
2178   Abv->Add(BitCodeAbbrevOp(serialization::DECL_VAR));
2179   // Redeclarable
2180   Abv->Add(BitCodeAbbrevOp(0));                       // No redeclaration
2181   // Decl
2182   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclContext
2183   Abv->Add(BitCodeAbbrevOp(0));                       // LexicalDeclContext
2184   Abv->Add(BitCodeAbbrevOp(0));                       // isInvalidDecl
2185   Abv->Add(BitCodeAbbrevOp(0));                       // HasAttrs
2186   Abv->Add(BitCodeAbbrevOp(0));                       // isImplicit
2187   Abv->Add(BitCodeAbbrevOp(0));                       // isUsed
2188   Abv->Add(BitCodeAbbrevOp(0));                       // isReferenced
2189   Abv->Add(BitCodeAbbrevOp(0));                   // TopLevelDeclInObjCContainer
2190   Abv->Add(BitCodeAbbrevOp(AS_none));                 // C++ AccessSpecifier
2191   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); // ModuleOwnershipKind
2192   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // SubmoduleID
2193   // NamedDecl
2194   Abv->Add(BitCodeAbbrevOp(0));                       // NameKind = Identifier
2195   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Name
2196   Abv->Add(BitCodeAbbrevOp(0));                       // AnonDeclNumber
2197   // ValueDecl
2198   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
2199   // DeclaratorDecl
2200   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // InnerStartLoc
2201   Abv->Add(BitCodeAbbrevOp(0));                       // hasExtInfo
2202   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // TSIType
2203   // VarDecl
2204   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); // SClass
2205   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2)); // TSCSpec
2206   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2)); // InitStyle
2207   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isARCPseudoStrong
2208   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsThisDeclarationADemotedDefinition
2209   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isExceptionVariable
2210   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isNRVOVariable
2211   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isCXXForRangeDecl
2212   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isObjCForDecl
2213   Abv->Add(BitCodeAbbrevOp(0));                         // isInline
2214   Abv->Add(BitCodeAbbrevOp(0));                         // isInlineSpecified
2215   Abv->Add(BitCodeAbbrevOp(0));                         // isConstexpr
2216   Abv->Add(BitCodeAbbrevOp(0));                         // isInitCapture
2217   Abv->Add(BitCodeAbbrevOp(0));                         // isPrevDeclInSameScope
2218   Abv->Add(BitCodeAbbrevOp(0));                         // ImplicitParamKind
2219   Abv->Add(BitCodeAbbrevOp(0));                         // EscapingByref
2220   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); // Linkage
2221   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); // HasConstant*
2222   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2)); // VarKind (local enum)
2223   // Type Source Info
2224   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2225   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // TypeLoc
2226   DeclVarAbbrev = Stream.EmitAbbrev(std::move(Abv));
2227 
2228   // Abbreviation for DECL_CXX_METHOD
2229   Abv = std::make_shared<BitCodeAbbrev>();
2230   Abv->Add(BitCodeAbbrevOp(serialization::DECL_CXX_METHOD));
2231   // RedeclarableDecl
2232   Abv->Add(BitCodeAbbrevOp(0));                         // CanonicalDecl
2233   // Decl
2234   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // DeclContext
2235   Abv->Add(BitCodeAbbrevOp(0));                         // LexicalDeclContext
2236   Abv->Add(BitCodeAbbrevOp(0));                         // Invalid
2237   Abv->Add(BitCodeAbbrevOp(0));                         // HasAttrs
2238   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Implicit
2239   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Used
2240   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Referenced
2241   Abv->Add(BitCodeAbbrevOp(0));                         // InObjCContainer
2242   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2)); // Access
2243   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); // ModuleOwnershipKind
2244   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // SubmoduleID
2245   // NamedDecl
2246   Abv->Add(BitCodeAbbrevOp(DeclarationName::Identifier)); // NameKind
2247   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // Identifier
2248   Abv->Add(BitCodeAbbrevOp(0));                         // AnonDeclNumber
2249   // ValueDecl
2250   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // Type
2251   // DeclaratorDecl
2252   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // InnerLocStart
2253   Abv->Add(BitCodeAbbrevOp(0));                         // HasExtInfo
2254   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // TSIType
2255   // FunctionDecl
2256   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 11)); // IDNS
2257   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); // StorageClass
2258   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Inline
2259   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // InlineSpecified
2260   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // VirtualAsWritten
2261   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Pure
2262   Abv->Add(BitCodeAbbrevOp(0));                         // HasInheritedProto
2263   Abv->Add(BitCodeAbbrevOp(1));                         // HasWrittenProto
2264   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Deleted
2265   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Trivial
2266   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // TrivialForCall
2267   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Defaulted
2268   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // ExplicitlyDefaulted
2269   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // ImplicitReturnZero
2270   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2)); // Constexpr
2271   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // UsesSEHTry
2272   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // SkippedBody
2273   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // MultiVersion
2274   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // LateParsed
2275   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); // Linkage
2276   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // LocEnd
2277   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // ODRHash
2278   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); // TemplateKind
2279   // This Array slurps the rest of the record. Fortunately we want to encode
2280   // (nearly) all the remaining (variable number of) fields in the same way.
2281   //
2282   // This is the function template information if any, then
2283   //         NumParams and Params[] from FunctionDecl, and
2284   //         NumOverriddenMethods, OverriddenMethods[] from CXXMethodDecl.
2285   //
2286   //  Add an AbbrevOp for 'size then elements' and use it here.
2287   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2288   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
2289   DeclCXXMethodAbbrev = Stream.EmitAbbrev(std::move(Abv));
2290 
2291   unsigned ExprDependenceBits = llvm::BitWidth<ExprDependence>;
2292   // Abbreviation for EXPR_DECL_REF
2293   Abv = std::make_shared<BitCodeAbbrev>();
2294   Abv->Add(BitCodeAbbrevOp(serialization::EXPR_DECL_REF));
2295   //Stmt
2296   // Expr
2297   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
2298   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, ExprDependenceBits));
2299   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetValueKind
2300   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetObjectKind
2301   //DeclRefExpr
2302   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //HasQualifier
2303   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //GetDeclFound
2304   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //ExplicitTemplateArgs
2305   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //HadMultipleCandidates
2306   Abv->Add(BitCodeAbbrevOp(0)); // RefersToEnclosingVariableOrCapture
2307   Abv->Add(BitCodeAbbrevOp(0)); // NonOdrUseReason
2308   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclRef
2309   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Location
2310   DeclRefExprAbbrev = Stream.EmitAbbrev(std::move(Abv));
2311 
2312   // Abbreviation for EXPR_INTEGER_LITERAL
2313   Abv = std::make_shared<BitCodeAbbrev>();
2314   Abv->Add(BitCodeAbbrevOp(serialization::EXPR_INTEGER_LITERAL));
2315   //Stmt
2316   // Expr
2317   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
2318   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, ExprDependenceBits));
2319   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetValueKind
2320   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetObjectKind
2321   //Integer Literal
2322   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Location
2323   Abv->Add(BitCodeAbbrevOp(32));                      // Bit Width
2324   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Value
2325   IntegerLiteralAbbrev = Stream.EmitAbbrev(std::move(Abv));
2326 
2327   // Abbreviation for EXPR_CHARACTER_LITERAL
2328   Abv = std::make_shared<BitCodeAbbrev>();
2329   Abv->Add(BitCodeAbbrevOp(serialization::EXPR_CHARACTER_LITERAL));
2330   //Stmt
2331   // Expr
2332   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
2333   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, ExprDependenceBits));
2334   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetValueKind
2335   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetObjectKind
2336   //Character Literal
2337   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // getValue
2338   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Location
2339   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); // getKind
2340   CharacterLiteralAbbrev = Stream.EmitAbbrev(std::move(Abv));
2341 
2342   // Abbreviation for EXPR_IMPLICIT_CAST
2343   Abv = std::make_shared<BitCodeAbbrev>();
2344   Abv->Add(BitCodeAbbrevOp(serialization::EXPR_IMPLICIT_CAST));
2345   // Stmt
2346   // Expr
2347   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
2348   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, ExprDependenceBits));
2349   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetValueKind
2350   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetObjectKind
2351   // CastExpr
2352   Abv->Add(BitCodeAbbrevOp(0)); // PathSize
2353   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // HasFPFeatures
2354   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 6)); // CastKind
2355   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // PartOfExplicitCast
2356   // ImplicitCastExpr
2357   ExprImplicitCastAbbrev = Stream.EmitAbbrev(std::move(Abv));
2358 
2359   Abv = std::make_shared<BitCodeAbbrev>();
2360   Abv->Add(BitCodeAbbrevOp(serialization::DECL_CONTEXT_LEXICAL));
2361   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
2362   DeclContextLexicalAbbrev = Stream.EmitAbbrev(std::move(Abv));
2363 
2364   Abv = std::make_shared<BitCodeAbbrev>();
2365   Abv->Add(BitCodeAbbrevOp(serialization::DECL_CONTEXT_VISIBLE));
2366   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
2367   DeclContextVisibleLookupAbbrev = Stream.EmitAbbrev(std::move(Abv));
2368 }
2369 
2370 /// isRequiredDecl - Check if this is a "required" Decl, which must be seen by
2371 /// consumers of the AST.
2372 ///
2373 /// Such decls will always be deserialized from the AST file, so we would like
2374 /// this to be as restrictive as possible. Currently the predicate is driven by
2375 /// code generation requirements, if other clients have a different notion of
2376 /// what is "required" then we may have to consider an alternate scheme where
2377 /// clients can iterate over the top-level decls and get information on them,
2378 /// without necessary deserializing them. We could explicitly require such
2379 /// clients to use a separate API call to "realize" the decl. This should be
2380 /// relatively painless since they would presumably only do it for top-level
2381 /// decls.
2382 static bool isRequiredDecl(const Decl *D, ASTContext &Context,
2383                            bool WritingModule) {
2384   // An ObjCMethodDecl is never considered as "required" because its
2385   // implementation container always is.
2386 
2387   // File scoped assembly or obj-c or OMP declare target implementation must be
2388   // seen.
2389   if (isa<FileScopeAsmDecl>(D) || isa<ObjCImplDecl>(D))
2390     return true;
2391 
2392   if (WritingModule && isPartOfPerModuleInitializer(D)) {
2393     // These declarations are part of the module initializer, and are emitted
2394     // if and when the module is imported, rather than being emitted eagerly.
2395     return false;
2396   }
2397 
2398   return Context.DeclMustBeEmitted(D);
2399 }
2400 
2401 void ASTWriter::WriteDecl(ASTContext &Context, Decl *D) {
2402   PrettyDeclStackTraceEntry CrashInfo(Context, D, SourceLocation(),
2403                                       "serializing");
2404 
2405   // Determine the ID for this declaration.
2406   serialization::DeclID ID;
2407   assert(!D->isFromASTFile() && "should not be emitting imported decl");
2408   serialization::DeclID &IDR = DeclIDs[D];
2409   if (IDR == 0)
2410     IDR = NextDeclID++;
2411 
2412   ID = IDR;
2413 
2414   assert(ID >= FirstDeclID && "invalid decl ID");
2415 
2416   RecordData Record;
2417   ASTDeclWriter W(*this, Context, Record);
2418 
2419   // Build a record for this declaration
2420   W.Visit(D);
2421 
2422   // Emit this declaration to the bitstream.
2423   uint64_t Offset = W.Emit(D);
2424 
2425   // Record the offset for this declaration
2426   SourceLocation Loc = D->getLocation();
2427   unsigned Index = ID - FirstDeclID;
2428   if (DeclOffsets.size() == Index)
2429     DeclOffsets.emplace_back(Loc, Offset, DeclTypesBlockStartOffset);
2430   else if (DeclOffsets.size() < Index) {
2431     // FIXME: Can/should this happen?
2432     DeclOffsets.resize(Index+1);
2433     DeclOffsets[Index].setLocation(Loc);
2434     DeclOffsets[Index].setBitOffset(Offset, DeclTypesBlockStartOffset);
2435   } else {
2436     llvm_unreachable("declarations should be emitted in ID order");
2437   }
2438 
2439   SourceManager &SM = Context.getSourceManager();
2440   if (Loc.isValid() && SM.isLocalSourceLocation(Loc))
2441     associateDeclWithFile(D, ID);
2442 
2443   // Note declarations that should be deserialized eagerly so that we can add
2444   // them to a record in the AST file later.
2445   if (isRequiredDecl(D, Context, WritingModule))
2446     EagerlyDeserializedDecls.push_back(ID);
2447 }
2448 
2449 void ASTRecordWriter::AddFunctionDefinition(const FunctionDecl *FD) {
2450   // Switch case IDs are per function body.
2451   Writer->ClearSwitchCaseIDs();
2452 
2453   assert(FD->doesThisDeclarationHaveABody());
2454   bool ModulesCodegen = false;
2455   if (!FD->isDependentContext()) {
2456     Optional<GVALinkage> Linkage;
2457     if (Writer->WritingModule &&
2458         Writer->WritingModule->isInterfaceOrPartition()) {
2459       // When building a C++20 module interface unit or a partition unit, a
2460       // strong definition in the module interface is provided by the
2461       // compilation of that unit, not by its users. (Inline functions are still
2462       // emitted in module users.)
2463       Linkage = Writer->Context->GetGVALinkageForFunction(FD);
2464       ModulesCodegen = *Linkage == GVA_StrongExternal;
2465     }
2466     if (Writer->Context->getLangOpts().ModulesCodegen ||
2467         (FD->hasAttr<DLLExportAttr>() &&
2468          Writer->Context->getLangOpts().BuildingPCHWithObjectFile)) {
2469 
2470       // Under -fmodules-codegen, codegen is performed for all non-internal,
2471       // non-always_inline functions, unless they are available elsewhere.
2472       if (!FD->hasAttr<AlwaysInlineAttr>()) {
2473         if (!Linkage)
2474           Linkage = Writer->Context->GetGVALinkageForFunction(FD);
2475         ModulesCodegen =
2476             *Linkage != GVA_Internal && *Linkage != GVA_AvailableExternally;
2477       }
2478     }
2479   }
2480   Record->push_back(ModulesCodegen);
2481   if (ModulesCodegen)
2482     Writer->ModularCodegenDecls.push_back(Writer->GetDeclRef(FD));
2483   if (auto *CD = dyn_cast<CXXConstructorDecl>(FD)) {
2484     Record->push_back(CD->getNumCtorInitializers());
2485     if (CD->getNumCtorInitializers())
2486       AddCXXCtorInitializers(
2487           llvm::makeArrayRef(CD->init_begin(), CD->init_end()));
2488   }
2489   AddStmt(FD->getBody());
2490 }
2491