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