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