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