xref: /freebsd/contrib/llvm-project/clang/lib/Serialization/ASTWriterDecl.cpp (revision 3eaa9deb198a754efe38226024efe9b96e31e281)
1 //===--- ASTWriterDecl.cpp - Declaration Serialization --------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 //  This file implements serialization for Declarations.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "ASTCommon.h"
14 #include "clang/AST/Attr.h"
15 #include "clang/AST/DeclCXX.h"
16 #include "clang/AST/DeclContextInternals.h"
17 #include "clang/AST/DeclTemplate.h"
18 #include "clang/AST/DeclVisitor.h"
19 #include "clang/AST/Expr.h"
20 #include "clang/AST/OpenMPClause.h"
21 #include "clang/AST/PrettyDeclStackTrace.h"
22 #include "clang/Basic/SourceManager.h"
23 #include "clang/Serialization/ASTReader.h"
24 #include "clang/Serialization/ASTRecordWriter.h"
25 #include "llvm/Bitstream/BitstreamWriter.h"
26 #include "llvm/Support/ErrorHandling.h"
27 using namespace clang;
28 using namespace serialization;
29 
30 //===----------------------------------------------------------------------===//
31 // Declaration serialization
32 //===----------------------------------------------------------------------===//
33 
34 namespace clang {
35   class ASTDeclWriter : public DeclVisitor<ASTDeclWriter, void> {
36     ASTWriter &Writer;
37     ASTContext &Context;
38     ASTRecordWriter Record;
39 
40     serialization::DeclCode Code;
41     unsigned AbbrevToUse;
42 
43   public:
44     ASTDeclWriter(ASTWriter &Writer, ASTContext &Context,
45                   ASTWriter::RecordDataImpl &Record)
46         : Writer(Writer), Context(Context), Record(Writer, Record),
47           Code((serialization::DeclCode)0), AbbrevToUse(0) {}
48 
49     uint64_t Emit(Decl *D) {
50       if (!Code)
51         llvm::report_fatal_error(StringRef("unexpected declaration kind '") +
52             D->getDeclKindName() + "'");
53       return Record.Emit(Code, AbbrevToUse);
54     }
55 
56     void Visit(Decl *D);
57 
58     void VisitDecl(Decl *D);
59     void VisitPragmaCommentDecl(PragmaCommentDecl *D);
60     void VisitPragmaDetectMismatchDecl(PragmaDetectMismatchDecl *D);
61     void VisitTranslationUnitDecl(TranslationUnitDecl *D);
62     void VisitNamedDecl(NamedDecl *D);
63     void VisitLabelDecl(LabelDecl *LD);
64     void VisitNamespaceDecl(NamespaceDecl *D);
65     void VisitUsingDirectiveDecl(UsingDirectiveDecl *D);
66     void VisitNamespaceAliasDecl(NamespaceAliasDecl *D);
67     void VisitTypeDecl(TypeDecl *D);
68     void VisitTypedefNameDecl(TypedefNameDecl *D);
69     void VisitTypedefDecl(TypedefDecl *D);
70     void VisitTypeAliasDecl(TypeAliasDecl *D);
71     void VisitUnresolvedUsingTypenameDecl(UnresolvedUsingTypenameDecl *D);
72     void VisitTagDecl(TagDecl *D);
73     void VisitEnumDecl(EnumDecl *D);
74     void VisitRecordDecl(RecordDecl *D);
75     void VisitCXXRecordDecl(CXXRecordDecl *D);
76     void VisitClassTemplateSpecializationDecl(
77                                             ClassTemplateSpecializationDecl *D);
78     void VisitClassTemplatePartialSpecializationDecl(
79                                      ClassTemplatePartialSpecializationDecl *D);
80     void VisitVarTemplateSpecializationDecl(VarTemplateSpecializationDecl *D);
81     void VisitVarTemplatePartialSpecializationDecl(
82         VarTemplatePartialSpecializationDecl *D);
83     void VisitClassScopeFunctionSpecializationDecl(
84                                        ClassScopeFunctionSpecializationDecl *D);
85     void VisitTemplateTypeParmDecl(TemplateTypeParmDecl *D);
86     void VisitValueDecl(ValueDecl *D);
87     void VisitEnumConstantDecl(EnumConstantDecl *D);
88     void VisitUnresolvedUsingValueDecl(UnresolvedUsingValueDecl *D);
89     void VisitDeclaratorDecl(DeclaratorDecl *D);
90     void VisitFunctionDecl(FunctionDecl *D);
91     void VisitCXXDeductionGuideDecl(CXXDeductionGuideDecl *D);
92     void VisitCXXMethodDecl(CXXMethodDecl *D);
93     void VisitCXXConstructorDecl(CXXConstructorDecl *D);
94     void VisitCXXDestructorDecl(CXXDestructorDecl *D);
95     void VisitCXXConversionDecl(CXXConversionDecl *D);
96     void VisitFieldDecl(FieldDecl *D);
97     void VisitMSPropertyDecl(MSPropertyDecl *D);
98     void VisitIndirectFieldDecl(IndirectFieldDecl *D);
99     void VisitVarDecl(VarDecl *D);
100     void VisitImplicitParamDecl(ImplicitParamDecl *D);
101     void VisitParmVarDecl(ParmVarDecl *D);
102     void VisitDecompositionDecl(DecompositionDecl *D);
103     void VisitBindingDecl(BindingDecl *D);
104     void VisitNonTypeTemplateParmDecl(NonTypeTemplateParmDecl *D);
105     void VisitTemplateDecl(TemplateDecl *D);
106     void VisitConceptDecl(ConceptDecl *D);
107     void VisitRequiresExprBodyDecl(RequiresExprBodyDecl *D);
108     void VisitRedeclarableTemplateDecl(RedeclarableTemplateDecl *D);
109     void VisitClassTemplateDecl(ClassTemplateDecl *D);
110     void VisitVarTemplateDecl(VarTemplateDecl *D);
111     void VisitFunctionTemplateDecl(FunctionTemplateDecl *D);
112     void VisitTemplateTemplateParmDecl(TemplateTemplateParmDecl *D);
113     void VisitTypeAliasTemplateDecl(TypeAliasTemplateDecl *D);
114     void VisitUsingDecl(UsingDecl *D);
115     void VisitUsingPackDecl(UsingPackDecl *D);
116     void VisitUsingShadowDecl(UsingShadowDecl *D);
117     void VisitConstructorUsingShadowDecl(ConstructorUsingShadowDecl *D);
118     void VisitLinkageSpecDecl(LinkageSpecDecl *D);
119     void VisitExportDecl(ExportDecl *D);
120     void VisitFileScopeAsmDecl(FileScopeAsmDecl *D);
121     void VisitImportDecl(ImportDecl *D);
122     void VisitAccessSpecDecl(AccessSpecDecl *D);
123     void VisitFriendDecl(FriendDecl *D);
124     void VisitFriendTemplateDecl(FriendTemplateDecl *D);
125     void VisitStaticAssertDecl(StaticAssertDecl *D);
126     void VisitBlockDecl(BlockDecl *D);
127     void VisitCapturedDecl(CapturedDecl *D);
128     void VisitEmptyDecl(EmptyDecl *D);
129     void VisitLifetimeExtendedTemporaryDecl(LifetimeExtendedTemporaryDecl *D);
130 
131     void VisitDeclContext(DeclContext *DC);
132     template <typename T> void VisitRedeclarable(Redeclarable<T> *D);
133 
134 
135     // FIXME: Put in the same order is DeclNodes.td?
136     void VisitObjCMethodDecl(ObjCMethodDecl *D);
137     void VisitObjCTypeParamDecl(ObjCTypeParamDecl *D);
138     void VisitObjCContainerDecl(ObjCContainerDecl *D);
139     void VisitObjCInterfaceDecl(ObjCInterfaceDecl *D);
140     void VisitObjCIvarDecl(ObjCIvarDecl *D);
141     void VisitObjCProtocolDecl(ObjCProtocolDecl *D);
142     void VisitObjCAtDefsFieldDecl(ObjCAtDefsFieldDecl *D);
143     void VisitObjCCategoryDecl(ObjCCategoryDecl *D);
144     void VisitObjCImplDecl(ObjCImplDecl *D);
145     void VisitObjCCategoryImplDecl(ObjCCategoryImplDecl *D);
146     void VisitObjCImplementationDecl(ObjCImplementationDecl *D);
147     void VisitObjCCompatibleAliasDecl(ObjCCompatibleAliasDecl *D);
148     void VisitObjCPropertyDecl(ObjCPropertyDecl *D);
149     void VisitObjCPropertyImplDecl(ObjCPropertyImplDecl *D);
150     void VisitOMPThreadPrivateDecl(OMPThreadPrivateDecl *D);
151     void VisitOMPAllocateDecl(OMPAllocateDecl *D);
152     void VisitOMPRequiresDecl(OMPRequiresDecl *D);
153     void VisitOMPDeclareReductionDecl(OMPDeclareReductionDecl *D);
154     void VisitOMPDeclareMapperDecl(OMPDeclareMapperDecl *D);
155     void VisitOMPCapturedExprDecl(OMPCapturedExprDecl *D);
156 
157     /// Add an Objective-C type parameter list to the given record.
158     void AddObjCTypeParamList(ObjCTypeParamList *typeParams) {
159       // Empty type parameter list.
160       if (!typeParams) {
161         Record.push_back(0);
162         return;
163       }
164 
165       Record.push_back(typeParams->size());
166       for (auto typeParam : *typeParams) {
167         Record.AddDeclRef(typeParam);
168       }
169       Record.AddSourceLocation(typeParams->getLAngleLoc());
170       Record.AddSourceLocation(typeParams->getRAngleLoc());
171     }
172 
173     /// Add to the record the first declaration from each module file that
174     /// provides a declaration of D. The intent is to provide a sufficient
175     /// set such that reloading this set will load all current redeclarations.
176     void AddFirstDeclFromEachModule(const Decl *D, bool IncludeLocal) {
177       llvm::MapVector<ModuleFile*, const Decl*> Firsts;
178       // FIXME: We can skip entries that we know are implied by others.
179       for (const Decl *R = D->getMostRecentDecl(); R; R = R->getPreviousDecl()) {
180         if (R->isFromASTFile())
181           Firsts[Writer.Chain->getOwningModuleFile(R)] = R;
182         else if (IncludeLocal)
183           Firsts[nullptr] = R;
184       }
185       for (const auto &F : Firsts)
186         Record.AddDeclRef(F.second);
187     }
188 
189     /// Get the specialization decl from an entry in the specialization list.
190     template <typename EntryType>
191     typename RedeclarableTemplateDecl::SpecEntryTraits<EntryType>::DeclType *
192     getSpecializationDecl(EntryType &T) {
193       return RedeclarableTemplateDecl::SpecEntryTraits<EntryType>::getDecl(&T);
194     }
195 
196     /// Get the list of partial specializations from a template's common ptr.
197     template<typename T>
198     decltype(T::PartialSpecializations) &getPartialSpecializations(T *Common) {
199       return Common->PartialSpecializations;
200     }
201     ArrayRef<Decl> getPartialSpecializations(FunctionTemplateDecl::Common *) {
202       return None;
203     }
204 
205     template<typename DeclTy>
206     void AddTemplateSpecializations(DeclTy *D) {
207       auto *Common = D->getCommonPtr();
208 
209       // If we have any lazy specializations, and the external AST source is
210       // our chained AST reader, we can just write out the DeclIDs. Otherwise,
211       // we need to resolve them to actual declarations.
212       if (Writer.Chain != Writer.Context->getExternalSource() &&
213           Common->LazySpecializations) {
214         D->LoadLazySpecializations();
215         assert(!Common->LazySpecializations);
216       }
217 
218       ArrayRef<DeclID> LazySpecializations;
219       if (auto *LS = Common->LazySpecializations)
220         LazySpecializations = llvm::makeArrayRef(LS + 1, LS[0]);
221 
222       // Add a slot to the record for the number of specializations.
223       unsigned I = Record.size();
224       Record.push_back(0);
225 
226       // AddFirstDeclFromEachModule might trigger deserialization, invalidating
227       // *Specializations iterators.
228       llvm::SmallVector<const Decl*, 16> Specs;
229       for (auto &Entry : Common->Specializations)
230         Specs.push_back(getSpecializationDecl(Entry));
231       for (auto &Entry : getPartialSpecializations(Common))
232         Specs.push_back(getSpecializationDecl(Entry));
233 
234       for (auto *D : Specs) {
235         assert(D->isCanonicalDecl() && "non-canonical decl in set");
236         AddFirstDeclFromEachModule(D, /*IncludeLocal*/true);
237       }
238       Record.append(LazySpecializations.begin(), LazySpecializations.end());
239 
240       // Update the size entry we added earlier.
241       Record[I] = Record.size() - I - 1;
242     }
243 
244     /// Ensure that this template specialization is associated with the specified
245     /// template on reload.
246     void RegisterTemplateSpecialization(const Decl *Template,
247                                         const Decl *Specialization) {
248       Template = Template->getCanonicalDecl();
249 
250       // If the canonical template is local, we'll write out this specialization
251       // when we emit it.
252       // FIXME: We can do the same thing if there is any local declaration of
253       // the template, to avoid emitting an update record.
254       if (!Template->isFromASTFile())
255         return;
256 
257       // We only need to associate the first local declaration of the
258       // specialization. The other declarations will get pulled in by it.
259       if (Writer.getFirstLocalDecl(Specialization) != Specialization)
260         return;
261 
262       Writer.DeclUpdates[Template].push_back(ASTWriter::DeclUpdate(
263           UPD_CXX_ADDED_TEMPLATE_SPECIALIZATION, Specialization));
264     }
265   };
266 }
267 
268 void ASTDeclWriter::Visit(Decl *D) {
269   DeclVisitor<ASTDeclWriter>::Visit(D);
270 
271   // Source locations require array (variable-length) abbreviations.  The
272   // abbreviation infrastructure requires that arrays are encoded last, so
273   // we handle it here in the case of those classes derived from DeclaratorDecl
274   if (DeclaratorDecl *DD = dyn_cast<DeclaratorDecl>(D)) {
275     if (auto *TInfo = DD->getTypeSourceInfo())
276       Record.AddTypeLoc(TInfo->getTypeLoc());
277   }
278 
279   // Handle FunctionDecl's body here and write it after all other Stmts/Exprs
280   // have been written. We want it last because we will not read it back when
281   // retrieving it from the AST, we'll just lazily set the offset.
282   if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
283     Record.push_back(FD->doesThisDeclarationHaveABody());
284     if (FD->doesThisDeclarationHaveABody())
285       Record.AddFunctionDefinition(FD);
286   }
287 
288   // If this declaration is also a DeclContext, write blocks for the
289   // declarations that lexically stored inside its context and those
290   // declarations that are visible from its context.
291   if (DeclContext *DC = dyn_cast<DeclContext>(D))
292     VisitDeclContext(DC);
293 }
294 
295 void ASTDeclWriter::VisitDecl(Decl *D) {
296   Record.AddDeclRef(cast_or_null<Decl>(D->getDeclContext()));
297   if (D->getDeclContext() != D->getLexicalDeclContext())
298     Record.AddDeclRef(cast_or_null<Decl>(D->getLexicalDeclContext()));
299   else
300     Record.push_back(0);
301   Record.push_back(D->isInvalidDecl());
302   Record.push_back(D->hasAttrs());
303   if (D->hasAttrs())
304     Record.AddAttributes(D->getAttrs());
305   Record.push_back(D->isImplicit());
306   Record.push_back(D->isUsed(false));
307   Record.push_back(D->isReferenced());
308   Record.push_back(D->isTopLevelDeclInObjCContainer());
309   Record.push_back(D->getAccess());
310   Record.push_back(D->isModulePrivate());
311   Record.push_back(Writer.getSubmoduleID(D->getOwningModule()));
312 
313   // If this declaration injected a name into a context different from its
314   // lexical context, and that context is an imported namespace, we need to
315   // update its visible declarations to include this name.
316   //
317   // This happens when we instantiate a class with a friend declaration or a
318   // function with a local extern declaration, for instance.
319   //
320   // FIXME: Can we handle this in AddedVisibleDecl instead?
321   if (D->isOutOfLine()) {
322     auto *DC = D->getDeclContext();
323     while (auto *NS = dyn_cast<NamespaceDecl>(DC->getRedeclContext())) {
324       if (!NS->isFromASTFile())
325         break;
326       Writer.UpdatedDeclContexts.insert(NS->getPrimaryContext());
327       if (!NS->isInlineNamespace())
328         break;
329       DC = NS->getParent();
330     }
331   }
332 }
333 
334 void ASTDeclWriter::VisitPragmaCommentDecl(PragmaCommentDecl *D) {
335   StringRef Arg = D->getArg();
336   Record.push_back(Arg.size());
337   VisitDecl(D);
338   Record.AddSourceLocation(D->getBeginLoc());
339   Record.push_back(D->getCommentKind());
340   Record.AddString(Arg);
341   Code = serialization::DECL_PRAGMA_COMMENT;
342 }
343 
344 void ASTDeclWriter::VisitPragmaDetectMismatchDecl(
345     PragmaDetectMismatchDecl *D) {
346   StringRef Name = D->getName();
347   StringRef Value = D->getValue();
348   Record.push_back(Name.size() + 1 + Value.size());
349   VisitDecl(D);
350   Record.AddSourceLocation(D->getBeginLoc());
351   Record.AddString(Name);
352   Record.AddString(Value);
353   Code = serialization::DECL_PRAGMA_DETECT_MISMATCH;
354 }
355 
356 void ASTDeclWriter::VisitTranslationUnitDecl(TranslationUnitDecl *D) {
357   llvm_unreachable("Translation units aren't directly serialized");
358 }
359 
360 void ASTDeclWriter::VisitNamedDecl(NamedDecl *D) {
361   VisitDecl(D);
362   Record.AddDeclarationName(D->getDeclName());
363   Record.push_back(needsAnonymousDeclarationNumber(D)
364                        ? Writer.getAnonymousDeclarationNumber(D)
365                        : 0);
366 }
367 
368 void ASTDeclWriter::VisitTypeDecl(TypeDecl *D) {
369   VisitNamedDecl(D);
370   Record.AddSourceLocation(D->getBeginLoc());
371   Record.AddTypeRef(QualType(D->getTypeForDecl(), 0));
372 }
373 
374 void ASTDeclWriter::VisitTypedefNameDecl(TypedefNameDecl *D) {
375   VisitRedeclarable(D);
376   VisitTypeDecl(D);
377   Record.AddTypeSourceInfo(D->getTypeSourceInfo());
378   Record.push_back(D->isModed());
379   if (D->isModed())
380     Record.AddTypeRef(D->getUnderlyingType());
381   Record.AddDeclRef(D->getAnonDeclWithTypedefName(false));
382 }
383 
384 void ASTDeclWriter::VisitTypedefDecl(TypedefDecl *D) {
385   VisitTypedefNameDecl(D);
386   if (D->getDeclContext() == D->getLexicalDeclContext() &&
387       !D->hasAttrs() &&
388       !D->isImplicit() &&
389       D->getFirstDecl() == D->getMostRecentDecl() &&
390       !D->isInvalidDecl() &&
391       !D->isTopLevelDeclInObjCContainer() &&
392       !D->isModulePrivate() &&
393       !needsAnonymousDeclarationNumber(D) &&
394       D->getDeclName().getNameKind() == DeclarationName::Identifier)
395     AbbrevToUse = Writer.getDeclTypedefAbbrev();
396 
397   Code = serialization::DECL_TYPEDEF;
398 }
399 
400 void ASTDeclWriter::VisitTypeAliasDecl(TypeAliasDecl *D) {
401   VisitTypedefNameDecl(D);
402   Record.AddDeclRef(D->getDescribedAliasTemplate());
403   Code = serialization::DECL_TYPEALIAS;
404 }
405 
406 void ASTDeclWriter::VisitTagDecl(TagDecl *D) {
407   VisitRedeclarable(D);
408   VisitTypeDecl(D);
409   Record.push_back(D->getIdentifierNamespace());
410   Record.push_back((unsigned)D->getTagKind()); // FIXME: stable encoding
411   if (!isa<CXXRecordDecl>(D))
412     Record.push_back(D->isCompleteDefinition());
413   Record.push_back(D->isEmbeddedInDeclarator());
414   Record.push_back(D->isFreeStanding());
415   Record.push_back(D->isCompleteDefinitionRequired());
416   Record.AddSourceRange(D->getBraceRange());
417 
418   if (D->hasExtInfo()) {
419     Record.push_back(1);
420     Record.AddQualifierInfo(*D->getExtInfo());
421   } else if (auto *TD = D->getTypedefNameForAnonDecl()) {
422     Record.push_back(2);
423     Record.AddDeclRef(TD);
424     Record.AddIdentifierRef(TD->getDeclName().getAsIdentifierInfo());
425   } else {
426     Record.push_back(0);
427   }
428 }
429 
430 void ASTDeclWriter::VisitEnumDecl(EnumDecl *D) {
431   VisitTagDecl(D);
432   Record.AddTypeSourceInfo(D->getIntegerTypeSourceInfo());
433   if (!D->getIntegerTypeSourceInfo())
434     Record.AddTypeRef(D->getIntegerType());
435   Record.AddTypeRef(D->getPromotionType());
436   Record.push_back(D->getNumPositiveBits());
437   Record.push_back(D->getNumNegativeBits());
438   Record.push_back(D->isScoped());
439   Record.push_back(D->isScopedUsingClassTag());
440   Record.push_back(D->isFixed());
441   Record.push_back(D->getODRHash());
442 
443   if (MemberSpecializationInfo *MemberInfo = D->getMemberSpecializationInfo()) {
444     Record.AddDeclRef(MemberInfo->getInstantiatedFrom());
445     Record.push_back(MemberInfo->getTemplateSpecializationKind());
446     Record.AddSourceLocation(MemberInfo->getPointOfInstantiation());
447   } else {
448     Record.AddDeclRef(nullptr);
449   }
450 
451   if (D->getDeclContext() == D->getLexicalDeclContext() &&
452       !D->hasAttrs() &&
453       !D->isImplicit() &&
454       !D->isUsed(false) &&
455       !D->hasExtInfo() &&
456       !D->getTypedefNameForAnonDecl() &&
457       D->getFirstDecl() == D->getMostRecentDecl() &&
458       !D->isInvalidDecl() &&
459       !D->isReferenced() &&
460       !D->isTopLevelDeclInObjCContainer() &&
461       D->getAccess() == AS_none &&
462       !D->isModulePrivate() &&
463       !CXXRecordDecl::classofKind(D->getKind()) &&
464       !D->getIntegerTypeSourceInfo() &&
465       !D->getMemberSpecializationInfo() &&
466       !needsAnonymousDeclarationNumber(D) &&
467       D->getDeclName().getNameKind() == DeclarationName::Identifier)
468     AbbrevToUse = Writer.getDeclEnumAbbrev();
469 
470   Code = serialization::DECL_ENUM;
471 }
472 
473 void ASTDeclWriter::VisitRecordDecl(RecordDecl *D) {
474   VisitTagDecl(D);
475   Record.push_back(D->hasFlexibleArrayMember());
476   Record.push_back(D->isAnonymousStructOrUnion());
477   Record.push_back(D->hasObjectMember());
478   Record.push_back(D->hasVolatileMember());
479   Record.push_back(D->isNonTrivialToPrimitiveDefaultInitialize());
480   Record.push_back(D->isNonTrivialToPrimitiveCopy());
481   Record.push_back(D->isNonTrivialToPrimitiveDestroy());
482   Record.push_back(D->hasNonTrivialToPrimitiveDefaultInitializeCUnion());
483   Record.push_back(D->hasNonTrivialToPrimitiveDestructCUnion());
484   Record.push_back(D->hasNonTrivialToPrimitiveCopyCUnion());
485   Record.push_back(D->isParamDestroyedInCallee());
486   Record.push_back(D->getArgPassingRestrictions());
487 
488   if (D->getDeclContext() == D->getLexicalDeclContext() &&
489       !D->hasAttrs() &&
490       !D->isImplicit() &&
491       !D->isUsed(false) &&
492       !D->hasExtInfo() &&
493       !D->getTypedefNameForAnonDecl() &&
494       D->getFirstDecl() == D->getMostRecentDecl() &&
495       !D->isInvalidDecl() &&
496       !D->isReferenced() &&
497       !D->isTopLevelDeclInObjCContainer() &&
498       D->getAccess() == AS_none &&
499       !D->isModulePrivate() &&
500       !CXXRecordDecl::classofKind(D->getKind()) &&
501       !needsAnonymousDeclarationNumber(D) &&
502       D->getDeclName().getNameKind() == DeclarationName::Identifier)
503     AbbrevToUse = Writer.getDeclRecordAbbrev();
504 
505   Code = serialization::DECL_RECORD;
506 }
507 
508 void ASTDeclWriter::VisitValueDecl(ValueDecl *D) {
509   VisitNamedDecl(D);
510   Record.AddTypeRef(D->getType());
511 }
512 
513 void ASTDeclWriter::VisitEnumConstantDecl(EnumConstantDecl *D) {
514   VisitValueDecl(D);
515   Record.push_back(D->getInitExpr()? 1 : 0);
516   if (D->getInitExpr())
517     Record.AddStmt(D->getInitExpr());
518   Record.AddAPSInt(D->getInitVal());
519 
520   Code = serialization::DECL_ENUM_CONSTANT;
521 }
522 
523 void ASTDeclWriter::VisitDeclaratorDecl(DeclaratorDecl *D) {
524   VisitValueDecl(D);
525   Record.AddSourceLocation(D->getInnerLocStart());
526   Record.push_back(D->hasExtInfo());
527   if (D->hasExtInfo()) {
528     DeclaratorDecl::ExtInfo *Info = D->getExtInfo();
529     Record.AddQualifierInfo(*Info);
530     Record.AddStmt(Info->TrailingRequiresClause);
531   }
532   // The location information is deferred until the end of the record.
533   Record.AddTypeRef(D->getTypeSourceInfo() ? D->getTypeSourceInfo()->getType()
534                                            : QualType());
535 }
536 
537 void ASTDeclWriter::VisitFunctionDecl(FunctionDecl *D) {
538   VisitRedeclarable(D);
539   VisitDeclaratorDecl(D);
540   Record.AddDeclarationNameLoc(D->DNLoc, D->getDeclName());
541   Record.push_back(D->getIdentifierNamespace());
542 
543   // FunctionDecl's body is handled last at ASTWriterDecl::Visit,
544   // after everything else is written.
545   Record.push_back(static_cast<int>(D->getStorageClass())); // FIXME: stable encoding
546   Record.push_back(D->isInlineSpecified());
547   Record.push_back(D->isInlined());
548   Record.push_back(D->isVirtualAsWritten());
549   Record.push_back(D->isPure());
550   Record.push_back(D->hasInheritedPrototype());
551   Record.push_back(D->hasWrittenPrototype());
552   Record.push_back(D->isDeletedBit());
553   Record.push_back(D->isTrivial());
554   Record.push_back(D->isTrivialForCall());
555   Record.push_back(D->isDefaulted());
556   Record.push_back(D->isExplicitlyDefaulted());
557   Record.push_back(D->hasImplicitReturnZero());
558   Record.push_back(D->getConstexprKind());
559   Record.push_back(D->usesSEHTry());
560   Record.push_back(D->hasSkippedBody());
561   Record.push_back(D->isMultiVersion());
562   Record.push_back(D->isLateTemplateParsed());
563   Record.push_back(D->getLinkageInternal());
564   Record.AddSourceLocation(D->getEndLoc());
565 
566   Record.push_back(D->getODRHash());
567   Record.push_back(D->usesFPIntrin());
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::VisitIndirectFieldDecl(IndirectFieldDecl *D) {
957   VisitValueDecl(D);
958   Record.push_back(D->getChainingSize());
959 
960   for (const auto *P : D->chain())
961     Record.AddDeclRef(P);
962   Code = serialization::DECL_INDIRECTFIELD;
963 }
964 
965 void ASTDeclWriter::VisitVarDecl(VarDecl *D) {
966   VisitRedeclarable(D);
967   VisitDeclaratorDecl(D);
968   Record.push_back(D->getStorageClass());
969   Record.push_back(D->getTSCSpec());
970   Record.push_back(D->getInitStyle());
971   Record.push_back(D->isARCPseudoStrong());
972   if (!isa<ParmVarDecl>(D)) {
973     Record.push_back(D->isThisDeclarationADemotedDefinition());
974     Record.push_back(D->isExceptionVariable());
975     Record.push_back(D->isNRVOVariable());
976     Record.push_back(D->isCXXForRangeDecl());
977     Record.push_back(D->isObjCForDecl());
978     Record.push_back(D->isInline());
979     Record.push_back(D->isInlineSpecified());
980     Record.push_back(D->isConstexpr());
981     Record.push_back(D->isInitCapture());
982     Record.push_back(D->isPreviousDeclInSameBlockScope());
983     if (const auto *IPD = dyn_cast<ImplicitParamDecl>(D))
984       Record.push_back(static_cast<unsigned>(IPD->getParameterKind()));
985     else
986       Record.push_back(0);
987     Record.push_back(D->isEscapingByref());
988   }
989   Record.push_back(D->getLinkageInternal());
990 
991   if (D->getInit()) {
992     if (!D->isInitKnownICE())
993       Record.push_back(1);
994     else {
995       Record.push_back(
996           2 |
997           (D->isInitICE() ? 1 : 0) |
998           (D->ensureEvaluatedStmt()->HasConstantDestruction ? 4 : 0));
999     }
1000     Record.AddStmt(D->getInit());
1001   } else {
1002     Record.push_back(0);
1003   }
1004 
1005   if (D->hasAttr<BlocksAttr>() && D->getType()->getAsCXXRecordDecl()) {
1006     BlockVarCopyInit Init = Writer.Context->getBlockVarCopyInit(D);
1007     Record.AddStmt(Init.getCopyExpr());
1008     if (Init.getCopyExpr())
1009       Record.push_back(Init.canThrow());
1010   }
1011 
1012   if (D->getStorageDuration() == SD_Static) {
1013     bool ModulesCodegen = false;
1014     if (!D->getDescribedVarTemplate() && !D->getMemberSpecializationInfo() &&
1015         !isa<VarTemplateSpecializationDecl>(D)) {
1016       // When building a C++ Modules TS module interface unit, a strong
1017       // definition in the module interface is provided by the compilation of
1018       // that module interface unit, not by its users. (Inline variables are
1019       // still emitted in module users.)
1020       ModulesCodegen =
1021           (((Writer.WritingModule &&
1022              Writer.WritingModule->Kind == Module::ModuleInterfaceUnit) ||
1023             Writer.Context->getLangOpts().BuildingPCHWithObjectFile) &&
1024            Writer.Context->GetGVALinkageForVariable(D) == GVA_StrongExternal);
1025     }
1026     Record.push_back(ModulesCodegen);
1027     if (ModulesCodegen)
1028       Writer.ModularCodegenDecls.push_back(Writer.GetDeclRef(D));
1029   }
1030 
1031   enum {
1032     VarNotTemplate = 0, VarTemplate, StaticDataMemberSpecialization
1033   };
1034   if (VarTemplateDecl *TemplD = D->getDescribedVarTemplate()) {
1035     Record.push_back(VarTemplate);
1036     Record.AddDeclRef(TemplD);
1037   } else if (MemberSpecializationInfo *SpecInfo
1038                = D->getMemberSpecializationInfo()) {
1039     Record.push_back(StaticDataMemberSpecialization);
1040     Record.AddDeclRef(SpecInfo->getInstantiatedFrom());
1041     Record.push_back(SpecInfo->getTemplateSpecializationKind());
1042     Record.AddSourceLocation(SpecInfo->getPointOfInstantiation());
1043   } else {
1044     Record.push_back(VarNotTemplate);
1045   }
1046 
1047   if (D->getDeclContext() == D->getLexicalDeclContext() &&
1048       !D->hasAttrs() &&
1049       !D->isImplicit() &&
1050       !D->isUsed(false) &&
1051       !D->isInvalidDecl() &&
1052       !D->isReferenced() &&
1053       !D->isTopLevelDeclInObjCContainer() &&
1054       D->getAccess() == AS_none &&
1055       !D->isModulePrivate() &&
1056       !needsAnonymousDeclarationNumber(D) &&
1057       D->getDeclName().getNameKind() == DeclarationName::Identifier &&
1058       !D->hasExtInfo() &&
1059       D->getFirstDecl() == D->getMostRecentDecl() &&
1060       D->getKind() == Decl::Var &&
1061       !D->isInline() &&
1062       !D->isConstexpr() &&
1063       !D->isInitCapture() &&
1064       !D->isPreviousDeclInSameBlockScope() &&
1065       !(D->hasAttr<BlocksAttr>() && D->getType()->getAsCXXRecordDecl()) &&
1066       !D->isEscapingByref() &&
1067       D->getStorageDuration() != SD_Static &&
1068       !D->getMemberSpecializationInfo())
1069     AbbrevToUse = Writer.getDeclVarAbbrev();
1070 
1071   Code = serialization::DECL_VAR;
1072 }
1073 
1074 void ASTDeclWriter::VisitImplicitParamDecl(ImplicitParamDecl *D) {
1075   VisitVarDecl(D);
1076   Code = serialization::DECL_IMPLICIT_PARAM;
1077 }
1078 
1079 void ASTDeclWriter::VisitParmVarDecl(ParmVarDecl *D) {
1080   VisitVarDecl(D);
1081   Record.push_back(D->isObjCMethodParameter());
1082   Record.push_back(D->getFunctionScopeDepth());
1083   Record.push_back(D->getFunctionScopeIndex());
1084   Record.push_back(D->getObjCDeclQualifier()); // FIXME: stable encoding
1085   Record.push_back(D->isKNRPromoted());
1086   Record.push_back(D->hasInheritedDefaultArg());
1087   Record.push_back(D->hasUninstantiatedDefaultArg());
1088   if (D->hasUninstantiatedDefaultArg())
1089     Record.AddStmt(D->getUninstantiatedDefaultArg());
1090   Code = serialization::DECL_PARM_VAR;
1091 
1092   assert(!D->isARCPseudoStrong()); // can be true of ImplicitParamDecl
1093 
1094   // If the assumptions about the DECL_PARM_VAR abbrev are true, use it.  Here
1095   // we dynamically check for the properties that we optimize for, but don't
1096   // know are true of all PARM_VAR_DECLs.
1097   if (D->getDeclContext() == D->getLexicalDeclContext() &&
1098       !D->hasAttrs() &&
1099       !D->hasExtInfo() &&
1100       !D->isImplicit() &&
1101       !D->isUsed(false) &&
1102       !D->isInvalidDecl() &&
1103       !D->isReferenced() &&
1104       D->getAccess() == AS_none &&
1105       !D->isModulePrivate() &&
1106       D->getStorageClass() == 0 &&
1107       D->getInitStyle() == VarDecl::CInit && // Can params have anything else?
1108       D->getFunctionScopeDepth() == 0 &&
1109       D->getObjCDeclQualifier() == 0 &&
1110       !D->isKNRPromoted() &&
1111       !D->hasInheritedDefaultArg() &&
1112       D->getInit() == nullptr &&
1113       !D->hasUninstantiatedDefaultArg())  // No default expr.
1114     AbbrevToUse = Writer.getDeclParmVarAbbrev();
1115 
1116   // Check things we know are true of *every* PARM_VAR_DECL, which is more than
1117   // just us assuming it.
1118   assert(!D->getTSCSpec() && "PARM_VAR_DECL can't use TLS");
1119   assert(!D->isThisDeclarationADemotedDefinition()
1120          && "PARM_VAR_DECL can't be demoted definition.");
1121   assert(D->getAccess() == AS_none && "PARM_VAR_DECL can't be public/private");
1122   assert(!D->isExceptionVariable() && "PARM_VAR_DECL can't be exception var");
1123   assert(D->getPreviousDecl() == nullptr && "PARM_VAR_DECL can't be redecl");
1124   assert(!D->isStaticDataMember() &&
1125          "PARM_VAR_DECL can't be static data member");
1126 }
1127 
1128 void ASTDeclWriter::VisitDecompositionDecl(DecompositionDecl *D) {
1129   // Record the number of bindings first to simplify deserialization.
1130   Record.push_back(D->bindings().size());
1131 
1132   VisitVarDecl(D);
1133   for (auto *B : D->bindings())
1134     Record.AddDeclRef(B);
1135   Code = serialization::DECL_DECOMPOSITION;
1136 }
1137 
1138 void ASTDeclWriter::VisitBindingDecl(BindingDecl *D) {
1139   VisitValueDecl(D);
1140   Record.AddStmt(D->getBinding());
1141   Code = serialization::DECL_BINDING;
1142 }
1143 
1144 void ASTDeclWriter::VisitFileScopeAsmDecl(FileScopeAsmDecl *D) {
1145   VisitDecl(D);
1146   Record.AddStmt(D->getAsmString());
1147   Record.AddSourceLocation(D->getRParenLoc());
1148   Code = serialization::DECL_FILE_SCOPE_ASM;
1149 }
1150 
1151 void ASTDeclWriter::VisitEmptyDecl(EmptyDecl *D) {
1152   VisitDecl(D);
1153   Code = serialization::DECL_EMPTY;
1154 }
1155 
1156 void ASTDeclWriter::VisitLifetimeExtendedTemporaryDecl(
1157     LifetimeExtendedTemporaryDecl *D) {
1158   VisitDecl(D);
1159   Record.AddDeclRef(D->getExtendingDecl());
1160   Record.AddStmt(D->getTemporaryExpr());
1161   Record.push_back(static_cast<bool>(D->getValue()));
1162   if (D->getValue())
1163     Record.AddAPValue(*D->getValue());
1164   Record.push_back(D->getManglingNumber());
1165   Code = serialization::DECL_LIFETIME_EXTENDED_TEMPORARY;
1166 }
1167 void ASTDeclWriter::VisitBlockDecl(BlockDecl *D) {
1168   VisitDecl(D);
1169   Record.AddStmt(D->getBody());
1170   Record.AddTypeSourceInfo(D->getSignatureAsWritten());
1171   Record.push_back(D->param_size());
1172   for (ParmVarDecl *P : D->parameters())
1173     Record.AddDeclRef(P);
1174   Record.push_back(D->isVariadic());
1175   Record.push_back(D->blockMissingReturnType());
1176   Record.push_back(D->isConversionFromLambda());
1177   Record.push_back(D->doesNotEscape());
1178   Record.push_back(D->canAvoidCopyToHeap());
1179   Record.push_back(D->capturesCXXThis());
1180   Record.push_back(D->getNumCaptures());
1181   for (const auto &capture : D->captures()) {
1182     Record.AddDeclRef(capture.getVariable());
1183 
1184     unsigned flags = 0;
1185     if (capture.isByRef()) flags |= 1;
1186     if (capture.isNested()) flags |= 2;
1187     if (capture.hasCopyExpr()) flags |= 4;
1188     Record.push_back(flags);
1189 
1190     if (capture.hasCopyExpr()) Record.AddStmt(capture.getCopyExpr());
1191   }
1192 
1193   Code = serialization::DECL_BLOCK;
1194 }
1195 
1196 void ASTDeclWriter::VisitCapturedDecl(CapturedDecl *CD) {
1197   Record.push_back(CD->getNumParams());
1198   VisitDecl(CD);
1199   Record.push_back(CD->getContextParamPosition());
1200   Record.push_back(CD->isNothrow() ? 1 : 0);
1201   // Body is stored by VisitCapturedStmt.
1202   for (unsigned I = 0; I < CD->getNumParams(); ++I)
1203     Record.AddDeclRef(CD->getParam(I));
1204   Code = serialization::DECL_CAPTURED;
1205 }
1206 
1207 void ASTDeclWriter::VisitLinkageSpecDecl(LinkageSpecDecl *D) {
1208   VisitDecl(D);
1209   Record.push_back(D->getLanguage());
1210   Record.AddSourceLocation(D->getExternLoc());
1211   Record.AddSourceLocation(D->getRBraceLoc());
1212   Code = serialization::DECL_LINKAGE_SPEC;
1213 }
1214 
1215 void ASTDeclWriter::VisitExportDecl(ExportDecl *D) {
1216   VisitDecl(D);
1217   Record.AddSourceLocation(D->getRBraceLoc());
1218   Code = serialization::DECL_EXPORT;
1219 }
1220 
1221 void ASTDeclWriter::VisitLabelDecl(LabelDecl *D) {
1222   VisitNamedDecl(D);
1223   Record.AddSourceLocation(D->getBeginLoc());
1224   Code = serialization::DECL_LABEL;
1225 }
1226 
1227 
1228 void ASTDeclWriter::VisitNamespaceDecl(NamespaceDecl *D) {
1229   VisitRedeclarable(D);
1230   VisitNamedDecl(D);
1231   Record.push_back(D->isInline());
1232   Record.AddSourceLocation(D->getBeginLoc());
1233   Record.AddSourceLocation(D->getRBraceLoc());
1234 
1235   if (D->isOriginalNamespace())
1236     Record.AddDeclRef(D->getAnonymousNamespace());
1237   Code = serialization::DECL_NAMESPACE;
1238 
1239   if (Writer.hasChain() && D->isAnonymousNamespace() &&
1240       D == D->getMostRecentDecl()) {
1241     // This is a most recent reopening of the anonymous namespace. If its parent
1242     // is in a previous PCH (or is the TU), mark that parent for update, because
1243     // the original namespace always points to the latest re-opening of its
1244     // anonymous namespace.
1245     Decl *Parent = cast<Decl>(
1246         D->getParent()->getRedeclContext()->getPrimaryContext());
1247     if (Parent->isFromASTFile() || isa<TranslationUnitDecl>(Parent)) {
1248       Writer.DeclUpdates[Parent].push_back(
1249           ASTWriter::DeclUpdate(UPD_CXX_ADDED_ANONYMOUS_NAMESPACE, D));
1250     }
1251   }
1252 }
1253 
1254 void ASTDeclWriter::VisitNamespaceAliasDecl(NamespaceAliasDecl *D) {
1255   VisitRedeclarable(D);
1256   VisitNamedDecl(D);
1257   Record.AddSourceLocation(D->getNamespaceLoc());
1258   Record.AddSourceLocation(D->getTargetNameLoc());
1259   Record.AddNestedNameSpecifierLoc(D->getQualifierLoc());
1260   Record.AddDeclRef(D->getNamespace());
1261   Code = serialization::DECL_NAMESPACE_ALIAS;
1262 }
1263 
1264 void ASTDeclWriter::VisitUsingDecl(UsingDecl *D) {
1265   VisitNamedDecl(D);
1266   Record.AddSourceLocation(D->getUsingLoc());
1267   Record.AddNestedNameSpecifierLoc(D->getQualifierLoc());
1268   Record.AddDeclarationNameLoc(D->DNLoc, D->getDeclName());
1269   Record.AddDeclRef(D->FirstUsingShadow.getPointer());
1270   Record.push_back(D->hasTypename());
1271   Record.AddDeclRef(Context.getInstantiatedFromUsingDecl(D));
1272   Code = serialization::DECL_USING;
1273 }
1274 
1275 void ASTDeclWriter::VisitUsingPackDecl(UsingPackDecl *D) {
1276   Record.push_back(D->NumExpansions);
1277   VisitNamedDecl(D);
1278   Record.AddDeclRef(D->getInstantiatedFromUsingDecl());
1279   for (auto *E : D->expansions())
1280     Record.AddDeclRef(E);
1281   Code = serialization::DECL_USING_PACK;
1282 }
1283 
1284 void ASTDeclWriter::VisitUsingShadowDecl(UsingShadowDecl *D) {
1285   VisitRedeclarable(D);
1286   VisitNamedDecl(D);
1287   Record.AddDeclRef(D->getTargetDecl());
1288   Record.push_back(D->getIdentifierNamespace());
1289   Record.AddDeclRef(D->UsingOrNextShadow);
1290   Record.AddDeclRef(Context.getInstantiatedFromUsingShadowDecl(D));
1291   Code = serialization::DECL_USING_SHADOW;
1292 }
1293 
1294 void ASTDeclWriter::VisitConstructorUsingShadowDecl(
1295     ConstructorUsingShadowDecl *D) {
1296   VisitUsingShadowDecl(D);
1297   Record.AddDeclRef(D->NominatedBaseClassShadowDecl);
1298   Record.AddDeclRef(D->ConstructedBaseClassShadowDecl);
1299   Record.push_back(D->IsVirtual);
1300   Code = serialization::DECL_CONSTRUCTOR_USING_SHADOW;
1301 }
1302 
1303 void ASTDeclWriter::VisitUsingDirectiveDecl(UsingDirectiveDecl *D) {
1304   VisitNamedDecl(D);
1305   Record.AddSourceLocation(D->getUsingLoc());
1306   Record.AddSourceLocation(D->getNamespaceKeyLocation());
1307   Record.AddNestedNameSpecifierLoc(D->getQualifierLoc());
1308   Record.AddDeclRef(D->getNominatedNamespace());
1309   Record.AddDeclRef(dyn_cast<Decl>(D->getCommonAncestor()));
1310   Code = serialization::DECL_USING_DIRECTIVE;
1311 }
1312 
1313 void ASTDeclWriter::VisitUnresolvedUsingValueDecl(UnresolvedUsingValueDecl *D) {
1314   VisitValueDecl(D);
1315   Record.AddSourceLocation(D->getUsingLoc());
1316   Record.AddNestedNameSpecifierLoc(D->getQualifierLoc());
1317   Record.AddDeclarationNameLoc(D->DNLoc, D->getDeclName());
1318   Record.AddSourceLocation(D->getEllipsisLoc());
1319   Code = serialization::DECL_UNRESOLVED_USING_VALUE;
1320 }
1321 
1322 void ASTDeclWriter::VisitUnresolvedUsingTypenameDecl(
1323                                                UnresolvedUsingTypenameDecl *D) {
1324   VisitTypeDecl(D);
1325   Record.AddSourceLocation(D->getTypenameLoc());
1326   Record.AddNestedNameSpecifierLoc(D->getQualifierLoc());
1327   Record.AddSourceLocation(D->getEllipsisLoc());
1328   Code = serialization::DECL_UNRESOLVED_USING_TYPENAME;
1329 }
1330 
1331 void ASTDeclWriter::VisitCXXRecordDecl(CXXRecordDecl *D) {
1332   VisitRecordDecl(D);
1333 
1334   enum {
1335     CXXRecNotTemplate = 0, CXXRecTemplate, CXXRecMemberSpecialization
1336   };
1337   if (ClassTemplateDecl *TemplD = D->getDescribedClassTemplate()) {
1338     Record.push_back(CXXRecTemplate);
1339     Record.AddDeclRef(TemplD);
1340   } else if (MemberSpecializationInfo *MSInfo
1341                = D->getMemberSpecializationInfo()) {
1342     Record.push_back(CXXRecMemberSpecialization);
1343     Record.AddDeclRef(MSInfo->getInstantiatedFrom());
1344     Record.push_back(MSInfo->getTemplateSpecializationKind());
1345     Record.AddSourceLocation(MSInfo->getPointOfInstantiation());
1346   } else {
1347     Record.push_back(CXXRecNotTemplate);
1348   }
1349 
1350   Record.push_back(D->isThisDeclarationADefinition());
1351   if (D->isThisDeclarationADefinition())
1352     Record.AddCXXDefinitionData(D);
1353 
1354   // Store (what we currently believe to be) the key function to avoid
1355   // deserializing every method so we can compute it.
1356   if (D->isCompleteDefinition())
1357     Record.AddDeclRef(Context.getCurrentKeyFunction(D));
1358 
1359   Code = serialization::DECL_CXX_RECORD;
1360 }
1361 
1362 void ASTDeclWriter::VisitCXXMethodDecl(CXXMethodDecl *D) {
1363   VisitFunctionDecl(D);
1364   if (D->isCanonicalDecl()) {
1365     Record.push_back(D->size_overridden_methods());
1366     for (const CXXMethodDecl *MD : D->overridden_methods())
1367       Record.AddDeclRef(MD);
1368   } else {
1369     // We only need to record overridden methods once for the canonical decl.
1370     Record.push_back(0);
1371   }
1372 
1373   if (D->getDeclContext() == D->getLexicalDeclContext() &&
1374       D->getFirstDecl() == D->getMostRecentDecl() &&
1375       !D->isInvalidDecl() &&
1376       !D->hasAttrs() &&
1377       !D->isTopLevelDeclInObjCContainer() &&
1378       D->getDeclName().getNameKind() == DeclarationName::Identifier &&
1379       !D->hasExtInfo() &&
1380       !D->hasInheritedPrototype() &&
1381       D->hasWrittenPrototype())
1382     AbbrevToUse = Writer.getDeclCXXMethodAbbrev();
1383 
1384   Code = serialization::DECL_CXX_METHOD;
1385 }
1386 
1387 void ASTDeclWriter::VisitCXXConstructorDecl(CXXConstructorDecl *D) {
1388   Record.push_back(D->getTraillingAllocKind());
1389   addExplicitSpecifier(D->getExplicitSpecifier(), Record);
1390   if (auto Inherited = D->getInheritedConstructor()) {
1391     Record.AddDeclRef(Inherited.getShadowDecl());
1392     Record.AddDeclRef(Inherited.getConstructor());
1393   }
1394 
1395   VisitCXXMethodDecl(D);
1396   Code = serialization::DECL_CXX_CONSTRUCTOR;
1397 }
1398 
1399 void ASTDeclWriter::VisitCXXDestructorDecl(CXXDestructorDecl *D) {
1400   VisitCXXMethodDecl(D);
1401 
1402   Record.AddDeclRef(D->getOperatorDelete());
1403   if (D->getOperatorDelete())
1404     Record.AddStmt(D->getOperatorDeleteThisArg());
1405 
1406   Code = serialization::DECL_CXX_DESTRUCTOR;
1407 }
1408 
1409 void ASTDeclWriter::VisitCXXConversionDecl(CXXConversionDecl *D) {
1410   addExplicitSpecifier(D->getExplicitSpecifier(), Record);
1411   VisitCXXMethodDecl(D);
1412   Code = serialization::DECL_CXX_CONVERSION;
1413 }
1414 
1415 void ASTDeclWriter::VisitImportDecl(ImportDecl *D) {
1416   VisitDecl(D);
1417   Record.push_back(Writer.getSubmoduleID(D->getImportedModule()));
1418   ArrayRef<SourceLocation> IdentifierLocs = D->getIdentifierLocs();
1419   Record.push_back(!IdentifierLocs.empty());
1420   if (IdentifierLocs.empty()) {
1421     Record.AddSourceLocation(D->getEndLoc());
1422     Record.push_back(1);
1423   } else {
1424     for (unsigned I = 0, N = IdentifierLocs.size(); I != N; ++I)
1425       Record.AddSourceLocation(IdentifierLocs[I]);
1426     Record.push_back(IdentifierLocs.size());
1427   }
1428   // Note: the number of source locations must always be the last element in
1429   // the record.
1430   Code = serialization::DECL_IMPORT;
1431 }
1432 
1433 void ASTDeclWriter::VisitAccessSpecDecl(AccessSpecDecl *D) {
1434   VisitDecl(D);
1435   Record.AddSourceLocation(D->getColonLoc());
1436   Code = serialization::DECL_ACCESS_SPEC;
1437 }
1438 
1439 void ASTDeclWriter::VisitFriendDecl(FriendDecl *D) {
1440   // Record the number of friend type template parameter lists here
1441   // so as to simplify memory allocation during deserialization.
1442   Record.push_back(D->NumTPLists);
1443   VisitDecl(D);
1444   bool hasFriendDecl = D->Friend.is<NamedDecl*>();
1445   Record.push_back(hasFriendDecl);
1446   if (hasFriendDecl)
1447     Record.AddDeclRef(D->getFriendDecl());
1448   else
1449     Record.AddTypeSourceInfo(D->getFriendType());
1450   for (unsigned i = 0; i < D->NumTPLists; ++i)
1451     Record.AddTemplateParameterList(D->getFriendTypeTemplateParameterList(i));
1452   Record.AddDeclRef(D->getNextFriend());
1453   Record.push_back(D->UnsupportedFriend);
1454   Record.AddSourceLocation(D->FriendLoc);
1455   Code = serialization::DECL_FRIEND;
1456 }
1457 
1458 void ASTDeclWriter::VisitFriendTemplateDecl(FriendTemplateDecl *D) {
1459   VisitDecl(D);
1460   Record.push_back(D->getNumTemplateParameters());
1461   for (unsigned i = 0, e = D->getNumTemplateParameters(); i != e; ++i)
1462     Record.AddTemplateParameterList(D->getTemplateParameterList(i));
1463   Record.push_back(D->getFriendDecl() != nullptr);
1464   if (D->getFriendDecl())
1465     Record.AddDeclRef(D->getFriendDecl());
1466   else
1467     Record.AddTypeSourceInfo(D->getFriendType());
1468   Record.AddSourceLocation(D->getFriendLoc());
1469   Code = serialization::DECL_FRIEND_TEMPLATE;
1470 }
1471 
1472 void ASTDeclWriter::VisitTemplateDecl(TemplateDecl *D) {
1473   VisitNamedDecl(D);
1474 
1475   Record.AddDeclRef(D->getTemplatedDecl());
1476   Record.AddTemplateParameterList(D->getTemplateParameters());
1477 }
1478 
1479 void ASTDeclWriter::VisitConceptDecl(ConceptDecl *D) {
1480   VisitTemplateDecl(D);
1481   Record.AddStmt(D->getConstraintExpr());
1482   Code = serialization::DECL_CONCEPT;
1483 }
1484 
1485 void ASTDeclWriter::VisitRequiresExprBodyDecl(RequiresExprBodyDecl *D) {
1486   Code = serialization::DECL_REQUIRES_EXPR_BODY;
1487 }
1488 
1489 void ASTDeclWriter::VisitRedeclarableTemplateDecl(RedeclarableTemplateDecl *D) {
1490   VisitRedeclarable(D);
1491 
1492   // Emit data to initialize CommonOrPrev before VisitTemplateDecl so that
1493   // getCommonPtr() can be used while this is still initializing.
1494   if (D->isFirstDecl()) {
1495     // This declaration owns the 'common' pointer, so serialize that data now.
1496     Record.AddDeclRef(D->getInstantiatedFromMemberTemplate());
1497     if (D->getInstantiatedFromMemberTemplate())
1498       Record.push_back(D->isMemberSpecialization());
1499   }
1500 
1501   VisitTemplateDecl(D);
1502   Record.push_back(D->getIdentifierNamespace());
1503 }
1504 
1505 void ASTDeclWriter::VisitClassTemplateDecl(ClassTemplateDecl *D) {
1506   VisitRedeclarableTemplateDecl(D);
1507 
1508   if (D->isFirstDecl())
1509     AddTemplateSpecializations(D);
1510   Code = serialization::DECL_CLASS_TEMPLATE;
1511 }
1512 
1513 void ASTDeclWriter::VisitClassTemplateSpecializationDecl(
1514                                            ClassTemplateSpecializationDecl *D) {
1515   RegisterTemplateSpecialization(D->getSpecializedTemplate(), D);
1516 
1517   VisitCXXRecordDecl(D);
1518 
1519   llvm::PointerUnion<ClassTemplateDecl *,
1520                      ClassTemplatePartialSpecializationDecl *> InstFrom
1521     = D->getSpecializedTemplateOrPartial();
1522   if (Decl *InstFromD = InstFrom.dyn_cast<ClassTemplateDecl *>()) {
1523     Record.AddDeclRef(InstFromD);
1524   } else {
1525     Record.AddDeclRef(InstFrom.get<ClassTemplatePartialSpecializationDecl *>());
1526     Record.AddTemplateArgumentList(&D->getTemplateInstantiationArgs());
1527   }
1528 
1529   Record.AddTemplateArgumentList(&D->getTemplateArgs());
1530   Record.AddSourceLocation(D->getPointOfInstantiation());
1531   Record.push_back(D->getSpecializationKind());
1532   Record.push_back(D->isCanonicalDecl());
1533 
1534   if (D->isCanonicalDecl()) {
1535     // When reading, we'll add it to the folding set of the following template.
1536     Record.AddDeclRef(D->getSpecializedTemplate()->getCanonicalDecl());
1537   }
1538 
1539   // Explicit info.
1540   Record.AddTypeSourceInfo(D->getTypeAsWritten());
1541   if (D->getTypeAsWritten()) {
1542     Record.AddSourceLocation(D->getExternLoc());
1543     Record.AddSourceLocation(D->getTemplateKeywordLoc());
1544   }
1545 
1546   Code = serialization::DECL_CLASS_TEMPLATE_SPECIALIZATION;
1547 }
1548 
1549 void ASTDeclWriter::VisitClassTemplatePartialSpecializationDecl(
1550                                     ClassTemplatePartialSpecializationDecl *D) {
1551   Record.AddTemplateParameterList(D->getTemplateParameters());
1552   Record.AddASTTemplateArgumentListInfo(D->getTemplateArgsAsWritten());
1553 
1554   VisitClassTemplateSpecializationDecl(D);
1555 
1556   // These are read/set from/to the first declaration.
1557   if (D->getPreviousDecl() == nullptr) {
1558     Record.AddDeclRef(D->getInstantiatedFromMember());
1559     Record.push_back(D->isMemberSpecialization());
1560   }
1561 
1562   Code = serialization::DECL_CLASS_TEMPLATE_PARTIAL_SPECIALIZATION;
1563 }
1564 
1565 void ASTDeclWriter::VisitVarTemplateDecl(VarTemplateDecl *D) {
1566   VisitRedeclarableTemplateDecl(D);
1567 
1568   if (D->isFirstDecl())
1569     AddTemplateSpecializations(D);
1570   Code = serialization::DECL_VAR_TEMPLATE;
1571 }
1572 
1573 void ASTDeclWriter::VisitVarTemplateSpecializationDecl(
1574     VarTemplateSpecializationDecl *D) {
1575   RegisterTemplateSpecialization(D->getSpecializedTemplate(), D);
1576 
1577   VisitVarDecl(D);
1578 
1579   llvm::PointerUnion<VarTemplateDecl *, VarTemplatePartialSpecializationDecl *>
1580   InstFrom = D->getSpecializedTemplateOrPartial();
1581   if (Decl *InstFromD = InstFrom.dyn_cast<VarTemplateDecl *>()) {
1582     Record.AddDeclRef(InstFromD);
1583   } else {
1584     Record.AddDeclRef(InstFrom.get<VarTemplatePartialSpecializationDecl *>());
1585     Record.AddTemplateArgumentList(&D->getTemplateInstantiationArgs());
1586   }
1587 
1588   // Explicit info.
1589   Record.AddTypeSourceInfo(D->getTypeAsWritten());
1590   if (D->getTypeAsWritten()) {
1591     Record.AddSourceLocation(D->getExternLoc());
1592     Record.AddSourceLocation(D->getTemplateKeywordLoc());
1593   }
1594 
1595   Record.AddTemplateArgumentList(&D->getTemplateArgs());
1596   Record.AddSourceLocation(D->getPointOfInstantiation());
1597   Record.push_back(D->getSpecializationKind());
1598   Record.push_back(D->IsCompleteDefinition);
1599   Record.push_back(D->isCanonicalDecl());
1600 
1601   if (D->isCanonicalDecl()) {
1602     // When reading, we'll add it to the folding set of the following template.
1603     Record.AddDeclRef(D->getSpecializedTemplate()->getCanonicalDecl());
1604   }
1605 
1606   Code = serialization::DECL_VAR_TEMPLATE_SPECIALIZATION;
1607 }
1608 
1609 void ASTDeclWriter::VisitVarTemplatePartialSpecializationDecl(
1610     VarTemplatePartialSpecializationDecl *D) {
1611   Record.AddTemplateParameterList(D->getTemplateParameters());
1612   Record.AddASTTemplateArgumentListInfo(D->getTemplateArgsAsWritten());
1613 
1614   VisitVarTemplateSpecializationDecl(D);
1615 
1616   // These are read/set from/to the first declaration.
1617   if (D->getPreviousDecl() == nullptr) {
1618     Record.AddDeclRef(D->getInstantiatedFromMember());
1619     Record.push_back(D->isMemberSpecialization());
1620   }
1621 
1622   Code = serialization::DECL_VAR_TEMPLATE_PARTIAL_SPECIALIZATION;
1623 }
1624 
1625 void ASTDeclWriter::VisitClassScopeFunctionSpecializationDecl(
1626                                     ClassScopeFunctionSpecializationDecl *D) {
1627   VisitDecl(D);
1628   Record.AddDeclRef(D->getSpecialization());
1629   Record.push_back(D->hasExplicitTemplateArgs());
1630   if (D->hasExplicitTemplateArgs())
1631     Record.AddASTTemplateArgumentListInfo(D->getTemplateArgsAsWritten());
1632   Code = serialization::DECL_CLASS_SCOPE_FUNCTION_SPECIALIZATION;
1633 }
1634 
1635 
1636 void ASTDeclWriter::VisitFunctionTemplateDecl(FunctionTemplateDecl *D) {
1637   VisitRedeclarableTemplateDecl(D);
1638 
1639   if (D->isFirstDecl())
1640     AddTemplateSpecializations(D);
1641   Code = serialization::DECL_FUNCTION_TEMPLATE;
1642 }
1643 
1644 void ASTDeclWriter::VisitTemplateTypeParmDecl(TemplateTypeParmDecl *D) {
1645   Record.push_back(D->hasTypeConstraint());
1646   VisitTypeDecl(D);
1647 
1648   Record.push_back(D->wasDeclaredWithTypename());
1649 
1650   const TypeConstraint *TC = D->getTypeConstraint();
1651   Record.push_back(TC != nullptr);
1652   if (TC) {
1653     Record.AddNestedNameSpecifierLoc(TC->getNestedNameSpecifierLoc());
1654     Record.AddDeclarationNameInfo(TC->getConceptNameInfo());
1655     Record.AddDeclRef(TC->getNamedConcept());
1656     Record.push_back(TC->getTemplateArgsAsWritten() != nullptr);
1657     if (TC->getTemplateArgsAsWritten())
1658       Record.AddASTTemplateArgumentListInfo(TC->getTemplateArgsAsWritten());
1659     Record.AddStmt(TC->getImmediatelyDeclaredConstraint());
1660     Record.push_back(D->isExpandedParameterPack());
1661     if (D->isExpandedParameterPack())
1662       Record.push_back(D->getNumExpansionParameters());
1663   }
1664 
1665   bool OwnsDefaultArg = D->hasDefaultArgument() &&
1666                         !D->defaultArgumentWasInherited();
1667   Record.push_back(OwnsDefaultArg);
1668   if (OwnsDefaultArg)
1669     Record.AddTypeSourceInfo(D->getDefaultArgumentInfo());
1670 
1671   Code = serialization::DECL_TEMPLATE_TYPE_PARM;
1672 }
1673 
1674 void ASTDeclWriter::VisitNonTypeTemplateParmDecl(NonTypeTemplateParmDecl *D) {
1675   // For an expanded parameter pack, record the number of expansion types here
1676   // so that it's easier for deserialization to allocate the right amount of
1677   // memory.
1678   Expr *TypeConstraint = D->getPlaceholderTypeConstraint();
1679   Record.push_back(!!TypeConstraint);
1680   if (D->isExpandedParameterPack())
1681     Record.push_back(D->getNumExpansionTypes());
1682 
1683   VisitDeclaratorDecl(D);
1684   // TemplateParmPosition.
1685   Record.push_back(D->getDepth());
1686   Record.push_back(D->getPosition());
1687   if (TypeConstraint)
1688     Record.AddStmt(TypeConstraint);
1689 
1690   if (D->isExpandedParameterPack()) {
1691     for (unsigned I = 0, N = D->getNumExpansionTypes(); I != N; ++I) {
1692       Record.AddTypeRef(D->getExpansionType(I));
1693       Record.AddTypeSourceInfo(D->getExpansionTypeSourceInfo(I));
1694     }
1695 
1696     Code = serialization::DECL_EXPANDED_NON_TYPE_TEMPLATE_PARM_PACK;
1697   } else {
1698     // Rest of NonTypeTemplateParmDecl.
1699     Record.push_back(D->isParameterPack());
1700     bool OwnsDefaultArg = D->hasDefaultArgument() &&
1701                           !D->defaultArgumentWasInherited();
1702     Record.push_back(OwnsDefaultArg);
1703     if (OwnsDefaultArg)
1704       Record.AddStmt(D->getDefaultArgument());
1705     Code = serialization::DECL_NON_TYPE_TEMPLATE_PARM;
1706   }
1707 }
1708 
1709 void ASTDeclWriter::VisitTemplateTemplateParmDecl(TemplateTemplateParmDecl *D) {
1710   // For an expanded parameter pack, record the number of expansion types here
1711   // so that it's easier for deserialization to allocate the right amount of
1712   // memory.
1713   if (D->isExpandedParameterPack())
1714     Record.push_back(D->getNumExpansionTemplateParameters());
1715 
1716   VisitTemplateDecl(D);
1717   // TemplateParmPosition.
1718   Record.push_back(D->getDepth());
1719   Record.push_back(D->getPosition());
1720 
1721   if (D->isExpandedParameterPack()) {
1722     for (unsigned I = 0, N = D->getNumExpansionTemplateParameters();
1723          I != N; ++I)
1724       Record.AddTemplateParameterList(D->getExpansionTemplateParameters(I));
1725     Code = serialization::DECL_EXPANDED_TEMPLATE_TEMPLATE_PARM_PACK;
1726   } else {
1727     // Rest of TemplateTemplateParmDecl.
1728     Record.push_back(D->isParameterPack());
1729     bool OwnsDefaultArg = D->hasDefaultArgument() &&
1730                           !D->defaultArgumentWasInherited();
1731     Record.push_back(OwnsDefaultArg);
1732     if (OwnsDefaultArg)
1733       Record.AddTemplateArgumentLoc(D->getDefaultArgument());
1734     Code = serialization::DECL_TEMPLATE_TEMPLATE_PARM;
1735   }
1736 }
1737 
1738 void ASTDeclWriter::VisitTypeAliasTemplateDecl(TypeAliasTemplateDecl *D) {
1739   VisitRedeclarableTemplateDecl(D);
1740   Code = serialization::DECL_TYPE_ALIAS_TEMPLATE;
1741 }
1742 
1743 void ASTDeclWriter::VisitStaticAssertDecl(StaticAssertDecl *D) {
1744   VisitDecl(D);
1745   Record.AddStmt(D->getAssertExpr());
1746   Record.push_back(D->isFailed());
1747   Record.AddStmt(D->getMessage());
1748   Record.AddSourceLocation(D->getRParenLoc());
1749   Code = serialization::DECL_STATIC_ASSERT;
1750 }
1751 
1752 /// Emit the DeclContext part of a declaration context decl.
1753 void ASTDeclWriter::VisitDeclContext(DeclContext *DC) {
1754   Record.AddOffset(Writer.WriteDeclContextLexicalBlock(Context, DC));
1755   Record.AddOffset(Writer.WriteDeclContextVisibleBlock(Context, DC));
1756 }
1757 
1758 const Decl *ASTWriter::getFirstLocalDecl(const Decl *D) {
1759   assert(IsLocalDecl(D) && "expected a local declaration");
1760 
1761   const Decl *Canon = D->getCanonicalDecl();
1762   if (IsLocalDecl(Canon))
1763     return Canon;
1764 
1765   const Decl *&CacheEntry = FirstLocalDeclCache[Canon];
1766   if (CacheEntry)
1767     return CacheEntry;
1768 
1769   for (const Decl *Redecl = D; Redecl; Redecl = Redecl->getPreviousDecl())
1770     if (IsLocalDecl(Redecl))
1771       D = Redecl;
1772   return CacheEntry = D;
1773 }
1774 
1775 template <typename T>
1776 void ASTDeclWriter::VisitRedeclarable(Redeclarable<T> *D) {
1777   T *First = D->getFirstDecl();
1778   T *MostRecent = First->getMostRecentDecl();
1779   T *DAsT = static_cast<T *>(D);
1780   if (MostRecent != First) {
1781     assert(isRedeclarableDeclKind(DAsT->getKind()) &&
1782            "Not considered redeclarable?");
1783 
1784     Record.AddDeclRef(First);
1785 
1786     // Write out a list of local redeclarations of this declaration if it's the
1787     // first local declaration in the chain.
1788     const Decl *FirstLocal = Writer.getFirstLocalDecl(DAsT);
1789     if (DAsT == FirstLocal) {
1790       // Emit a list of all imported first declarations so that we can be sure
1791       // that all redeclarations visible to this module are before D in the
1792       // redecl chain.
1793       unsigned I = Record.size();
1794       Record.push_back(0);
1795       if (Writer.Chain)
1796         AddFirstDeclFromEachModule(DAsT, /*IncludeLocal*/false);
1797       // This is the number of imported first declarations + 1.
1798       Record[I] = Record.size() - I;
1799 
1800       // Collect the set of local redeclarations of this declaration, from
1801       // newest to oldest.
1802       ASTWriter::RecordData LocalRedecls;
1803       ASTRecordWriter LocalRedeclWriter(Record, LocalRedecls);
1804       for (const Decl *Prev = FirstLocal->getMostRecentDecl();
1805            Prev != FirstLocal; Prev = Prev->getPreviousDecl())
1806         if (!Prev->isFromASTFile())
1807           LocalRedeclWriter.AddDeclRef(Prev);
1808 
1809       // If we have any redecls, write them now as a separate record preceding
1810       // the declaration itself.
1811       if (LocalRedecls.empty())
1812         Record.push_back(0);
1813       else
1814         Record.AddOffset(LocalRedeclWriter.Emit(LOCAL_REDECLARATIONS));
1815     } else {
1816       Record.push_back(0);
1817       Record.AddDeclRef(FirstLocal);
1818     }
1819 
1820     // Make sure that we serialize both the previous and the most-recent
1821     // declarations, which (transitively) ensures that all declarations in the
1822     // chain get serialized.
1823     //
1824     // FIXME: This is not correct; when we reach an imported declaration we
1825     // won't emit its previous declaration.
1826     (void)Writer.GetDeclRef(D->getPreviousDecl());
1827     (void)Writer.GetDeclRef(MostRecent);
1828   } else {
1829     // We use the sentinel value 0 to indicate an only declaration.
1830     Record.push_back(0);
1831   }
1832 }
1833 
1834 void ASTDeclWriter::VisitOMPThreadPrivateDecl(OMPThreadPrivateDecl *D) {
1835   Record.push_back(D->varlist_size());
1836   VisitDecl(D);
1837   for (auto *I : D->varlists())
1838     Record.AddStmt(I);
1839   Code = serialization::DECL_OMP_THREADPRIVATE;
1840 }
1841 
1842 void ASTDeclWriter::VisitOMPAllocateDecl(OMPAllocateDecl *D) {
1843   Record.push_back(D->varlist_size());
1844   Record.push_back(D->clauselist_size());
1845   VisitDecl(D);
1846   for (auto *I : D->varlists())
1847     Record.AddStmt(I);
1848   for (OMPClause *C : D->clauselists())
1849     Record.writeOMPClause(C);
1850   Code = serialization::DECL_OMP_ALLOCATE;
1851 }
1852 
1853 void ASTDeclWriter::VisitOMPRequiresDecl(OMPRequiresDecl *D) {
1854   Record.push_back(D->clauselist_size());
1855   VisitDecl(D);
1856   for (OMPClause *C : D->clauselists())
1857     Record.writeOMPClause(C);
1858   Code = serialization::DECL_OMP_REQUIRES;
1859 }
1860 
1861 void ASTDeclWriter::VisitOMPDeclareReductionDecl(OMPDeclareReductionDecl *D) {
1862   VisitValueDecl(D);
1863   Record.AddSourceLocation(D->getBeginLoc());
1864   Record.AddStmt(D->getCombinerIn());
1865   Record.AddStmt(D->getCombinerOut());
1866   Record.AddStmt(D->getCombiner());
1867   Record.AddStmt(D->getInitOrig());
1868   Record.AddStmt(D->getInitPriv());
1869   Record.AddStmt(D->getInitializer());
1870   Record.push_back(D->getInitializerKind());
1871   Record.AddDeclRef(D->getPrevDeclInScope());
1872   Code = serialization::DECL_OMP_DECLARE_REDUCTION;
1873 }
1874 
1875 void ASTDeclWriter::VisitOMPDeclareMapperDecl(OMPDeclareMapperDecl *D) {
1876   Record.push_back(D->clauselist_size());
1877   VisitValueDecl(D);
1878   Record.AddSourceLocation(D->getBeginLoc());
1879   Record.AddStmt(D->getMapperVarRef());
1880   Record.AddDeclarationName(D->getVarName());
1881   Record.AddDeclRef(D->getPrevDeclInScope());
1882   for (OMPClause *C : D->clauselists())
1883     Record.writeOMPClause(C);
1884   Code = serialization::DECL_OMP_DECLARE_MAPPER;
1885 }
1886 
1887 void ASTDeclWriter::VisitOMPCapturedExprDecl(OMPCapturedExprDecl *D) {
1888   VisitVarDecl(D);
1889   Code = serialization::DECL_OMP_CAPTUREDEXPR;
1890 }
1891 
1892 //===----------------------------------------------------------------------===//
1893 // ASTWriter Implementation
1894 //===----------------------------------------------------------------------===//
1895 
1896 void ASTWriter::WriteDeclAbbrevs() {
1897   using namespace llvm;
1898 
1899   std::shared_ptr<BitCodeAbbrev> Abv;
1900 
1901   // Abbreviation for DECL_FIELD
1902   Abv = std::make_shared<BitCodeAbbrev>();
1903   Abv->Add(BitCodeAbbrevOp(serialization::DECL_FIELD));
1904   // Decl
1905   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclContext
1906   Abv->Add(BitCodeAbbrevOp(0));                       // LexicalDeclContext
1907   Abv->Add(BitCodeAbbrevOp(0));                       // isInvalidDecl
1908   Abv->Add(BitCodeAbbrevOp(0));                       // HasAttrs
1909   Abv->Add(BitCodeAbbrevOp(0));                       // isImplicit
1910   Abv->Add(BitCodeAbbrevOp(0));                       // isUsed
1911   Abv->Add(BitCodeAbbrevOp(0));                       // isReferenced
1912   Abv->Add(BitCodeAbbrevOp(0));                   // TopLevelDeclInObjCContainer
1913   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2));  // AccessSpecifier
1914   Abv->Add(BitCodeAbbrevOp(0));                       // ModulePrivate
1915   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // SubmoduleID
1916   // NamedDecl
1917   Abv->Add(BitCodeAbbrevOp(0));                       // NameKind = Identifier
1918   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Name
1919   Abv->Add(BitCodeAbbrevOp(0));                       // AnonDeclNumber
1920   // ValueDecl
1921   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
1922   // DeclaratorDecl
1923   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // InnerStartLoc
1924   Abv->Add(BitCodeAbbrevOp(0));                       // hasExtInfo
1925   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // TSIType
1926   // FieldDecl
1927   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isMutable
1928   Abv->Add(BitCodeAbbrevOp(0));                       // InitStyle
1929   // Type Source Info
1930   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1931   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // TypeLoc
1932   DeclFieldAbbrev = Stream.EmitAbbrev(std::move(Abv));
1933 
1934   // Abbreviation for DECL_OBJC_IVAR
1935   Abv = std::make_shared<BitCodeAbbrev>();
1936   Abv->Add(BitCodeAbbrevOp(serialization::DECL_OBJC_IVAR));
1937   // Decl
1938   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclContext
1939   Abv->Add(BitCodeAbbrevOp(0));                       // LexicalDeclContext
1940   Abv->Add(BitCodeAbbrevOp(0));                       // isInvalidDecl
1941   Abv->Add(BitCodeAbbrevOp(0));                       // HasAttrs
1942   Abv->Add(BitCodeAbbrevOp(0));                       // isImplicit
1943   Abv->Add(BitCodeAbbrevOp(0));                       // isUsed
1944   Abv->Add(BitCodeAbbrevOp(0));                       // isReferenced
1945   Abv->Add(BitCodeAbbrevOp(0));                   // TopLevelDeclInObjCContainer
1946   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2));  // AccessSpecifier
1947   Abv->Add(BitCodeAbbrevOp(0));                       // ModulePrivate
1948   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // SubmoduleID
1949   // NamedDecl
1950   Abv->Add(BitCodeAbbrevOp(0));                       // NameKind = Identifier
1951   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Name
1952   Abv->Add(BitCodeAbbrevOp(0));                       // AnonDeclNumber
1953   // ValueDecl
1954   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
1955   // DeclaratorDecl
1956   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // InnerStartLoc
1957   Abv->Add(BitCodeAbbrevOp(0));                       // hasExtInfo
1958   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // TSIType
1959   // FieldDecl
1960   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isMutable
1961   Abv->Add(BitCodeAbbrevOp(0));                       // InitStyle
1962   // ObjC Ivar
1963   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // getAccessControl
1964   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // getSynthesize
1965   // Type Source Info
1966   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1967   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // TypeLoc
1968   DeclObjCIvarAbbrev = Stream.EmitAbbrev(std::move(Abv));
1969 
1970   // Abbreviation for DECL_ENUM
1971   Abv = std::make_shared<BitCodeAbbrev>();
1972   Abv->Add(BitCodeAbbrevOp(serialization::DECL_ENUM));
1973   // Redeclarable
1974   Abv->Add(BitCodeAbbrevOp(0));                       // No redeclaration
1975   // Decl
1976   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclContext
1977   Abv->Add(BitCodeAbbrevOp(0));                       // LexicalDeclContext
1978   Abv->Add(BitCodeAbbrevOp(0));                       // isInvalidDecl
1979   Abv->Add(BitCodeAbbrevOp(0));                       // HasAttrs
1980   Abv->Add(BitCodeAbbrevOp(0));                       // isImplicit
1981   Abv->Add(BitCodeAbbrevOp(0));                       // isUsed
1982   Abv->Add(BitCodeAbbrevOp(0));                       // isReferenced
1983   Abv->Add(BitCodeAbbrevOp(0));                   // TopLevelDeclInObjCContainer
1984   Abv->Add(BitCodeAbbrevOp(AS_none));                 // C++ AccessSpecifier
1985   Abv->Add(BitCodeAbbrevOp(0));                       // ModulePrivate
1986   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // SubmoduleID
1987   // NamedDecl
1988   Abv->Add(BitCodeAbbrevOp(0));                       // NameKind = Identifier
1989   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Name
1990   Abv->Add(BitCodeAbbrevOp(0));                       // AnonDeclNumber
1991   // TypeDecl
1992   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Source Location
1993   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type Ref
1994   // TagDecl
1995   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // IdentifierNamespace
1996   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // getTagKind
1997   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isCompleteDefinition
1998   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // EmbeddedInDeclarator
1999   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsFreeStanding
2000   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsCompleteDefinitionRequired
2001   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // SourceLocation
2002   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // SourceLocation
2003   Abv->Add(BitCodeAbbrevOp(0));                         // ExtInfoKind
2004   // EnumDecl
2005   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // AddTypeRef
2006   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // IntegerType
2007   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // getPromotionType
2008   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // getNumPositiveBits
2009   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // getNumNegativeBits
2010   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isScoped
2011   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isScopedUsingClassTag
2012   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isFixed
2013   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));// ODRHash
2014   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // InstantiatedMembEnum
2015   // DC
2016   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // LexicalOffset
2017   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // VisibleOffset
2018   DeclEnumAbbrev = Stream.EmitAbbrev(std::move(Abv));
2019 
2020   // Abbreviation for DECL_RECORD
2021   Abv = std::make_shared<BitCodeAbbrev>();
2022   Abv->Add(BitCodeAbbrevOp(serialization::DECL_RECORD));
2023   // Redeclarable
2024   Abv->Add(BitCodeAbbrevOp(0));                       // No redeclaration
2025   // Decl
2026   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclContext
2027   Abv->Add(BitCodeAbbrevOp(0));                       // LexicalDeclContext
2028   Abv->Add(BitCodeAbbrevOp(0));                       // isInvalidDecl
2029   Abv->Add(BitCodeAbbrevOp(0));                       // HasAttrs
2030   Abv->Add(BitCodeAbbrevOp(0));                       // isImplicit
2031   Abv->Add(BitCodeAbbrevOp(0));                       // isUsed
2032   Abv->Add(BitCodeAbbrevOp(0));                       // isReferenced
2033   Abv->Add(BitCodeAbbrevOp(0));                   // TopLevelDeclInObjCContainer
2034   Abv->Add(BitCodeAbbrevOp(AS_none));                 // C++ AccessSpecifier
2035   Abv->Add(BitCodeAbbrevOp(0));                       // ModulePrivate
2036   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // SubmoduleID
2037   // NamedDecl
2038   Abv->Add(BitCodeAbbrevOp(0));                       // NameKind = Identifier
2039   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Name
2040   Abv->Add(BitCodeAbbrevOp(0));                       // AnonDeclNumber
2041   // TypeDecl
2042   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Source Location
2043   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type Ref
2044   // TagDecl
2045   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // IdentifierNamespace
2046   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // getTagKind
2047   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isCompleteDefinition
2048   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // EmbeddedInDeclarator
2049   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsFreeStanding
2050   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsCompleteDefinitionRequired
2051   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // SourceLocation
2052   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // SourceLocation
2053   Abv->Add(BitCodeAbbrevOp(0));                         // ExtInfoKind
2054   // RecordDecl
2055   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // FlexibleArrayMember
2056   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // AnonymousStructUnion
2057   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // hasObjectMember
2058   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // hasVolatileMember
2059 
2060   // isNonTrivialToPrimitiveDefaultInitialize
2061   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
2062   // isNonTrivialToPrimitiveCopy
2063   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
2064   // isNonTrivialToPrimitiveDestroy
2065   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
2066   // hasNonTrivialToPrimitiveDefaultInitializeCUnion
2067   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
2068   // hasNonTrivialToPrimitiveDestructCUnion
2069   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
2070   // hasNonTrivialToPrimitiveCopyCUnion
2071   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
2072   // isParamDestroyedInCallee
2073   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
2074   // getArgPassingRestrictions
2075   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2));
2076 
2077   // DC
2078   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // LexicalOffset
2079   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // VisibleOffset
2080   DeclRecordAbbrev = Stream.EmitAbbrev(std::move(Abv));
2081 
2082   // Abbreviation for DECL_PARM_VAR
2083   Abv = std::make_shared<BitCodeAbbrev>();
2084   Abv->Add(BitCodeAbbrevOp(serialization::DECL_PARM_VAR));
2085   // Redeclarable
2086   Abv->Add(BitCodeAbbrevOp(0));                       // No redeclaration
2087   // Decl
2088   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclContext
2089   Abv->Add(BitCodeAbbrevOp(0));                       // LexicalDeclContext
2090   Abv->Add(BitCodeAbbrevOp(0));                       // isInvalidDecl
2091   Abv->Add(BitCodeAbbrevOp(0));                       // HasAttrs
2092   Abv->Add(BitCodeAbbrevOp(0));                       // isImplicit
2093   Abv->Add(BitCodeAbbrevOp(0));                       // isUsed
2094   Abv->Add(BitCodeAbbrevOp(0));                       // isReferenced
2095   Abv->Add(BitCodeAbbrevOp(0));                   // TopLevelDeclInObjCContainer
2096   Abv->Add(BitCodeAbbrevOp(AS_none));                 // C++ AccessSpecifier
2097   Abv->Add(BitCodeAbbrevOp(0));                       // ModulePrivate
2098   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // SubmoduleID
2099   // NamedDecl
2100   Abv->Add(BitCodeAbbrevOp(0));                       // NameKind = Identifier
2101   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Name
2102   Abv->Add(BitCodeAbbrevOp(0));                       // AnonDeclNumber
2103   // ValueDecl
2104   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
2105   // DeclaratorDecl
2106   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // InnerStartLoc
2107   Abv->Add(BitCodeAbbrevOp(0));                       // hasExtInfo
2108   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // TSIType
2109   // VarDecl
2110   Abv->Add(BitCodeAbbrevOp(0));                       // SClass
2111   Abv->Add(BitCodeAbbrevOp(0));                       // TSCSpec
2112   Abv->Add(BitCodeAbbrevOp(0));                       // InitStyle
2113   Abv->Add(BitCodeAbbrevOp(0));                       // ARCPseudoStrong
2114   Abv->Add(BitCodeAbbrevOp(0));                       // Linkage
2115   Abv->Add(BitCodeAbbrevOp(0));                       // HasInit
2116   Abv->Add(BitCodeAbbrevOp(0));                   // HasMemberSpecializationInfo
2117   // ParmVarDecl
2118   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsObjCMethodParameter
2119   Abv->Add(BitCodeAbbrevOp(0));                       // ScopeDepth
2120   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // ScopeIndex
2121   Abv->Add(BitCodeAbbrevOp(0));                       // ObjCDeclQualifier
2122   Abv->Add(BitCodeAbbrevOp(0));                       // KNRPromoted
2123   Abv->Add(BitCodeAbbrevOp(0));                       // HasInheritedDefaultArg
2124   Abv->Add(BitCodeAbbrevOp(0));                   // HasUninstantiatedDefaultArg
2125   // Type Source Info
2126   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2127   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // TypeLoc
2128   DeclParmVarAbbrev = Stream.EmitAbbrev(std::move(Abv));
2129 
2130   // Abbreviation for DECL_TYPEDEF
2131   Abv = std::make_shared<BitCodeAbbrev>();
2132   Abv->Add(BitCodeAbbrevOp(serialization::DECL_TYPEDEF));
2133   // Redeclarable
2134   Abv->Add(BitCodeAbbrevOp(0));                       // No redeclaration
2135   // Decl
2136   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclContext
2137   Abv->Add(BitCodeAbbrevOp(0));                       // LexicalDeclContext
2138   Abv->Add(BitCodeAbbrevOp(0));                       // isInvalidDecl
2139   Abv->Add(BitCodeAbbrevOp(0));                       // HasAttrs
2140   Abv->Add(BitCodeAbbrevOp(0));                       // isImplicit
2141   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isUsed
2142   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isReferenced
2143   Abv->Add(BitCodeAbbrevOp(0));                   // TopLevelDeclInObjCContainer
2144   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2)); // C++ AccessSpecifier
2145   Abv->Add(BitCodeAbbrevOp(0));                       // ModulePrivate
2146   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // SubmoduleID
2147   // NamedDecl
2148   Abv->Add(BitCodeAbbrevOp(0));                       // NameKind = Identifier
2149   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Name
2150   Abv->Add(BitCodeAbbrevOp(0));                       // AnonDeclNumber
2151   // TypeDecl
2152   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Source Location
2153   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type Ref
2154   // TypedefDecl
2155   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2156   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // TypeLoc
2157   DeclTypedefAbbrev = Stream.EmitAbbrev(std::move(Abv));
2158 
2159   // Abbreviation for DECL_VAR
2160   Abv = std::make_shared<BitCodeAbbrev>();
2161   Abv->Add(BitCodeAbbrevOp(serialization::DECL_VAR));
2162   // Redeclarable
2163   Abv->Add(BitCodeAbbrevOp(0));                       // No redeclaration
2164   // Decl
2165   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclContext
2166   Abv->Add(BitCodeAbbrevOp(0));                       // LexicalDeclContext
2167   Abv->Add(BitCodeAbbrevOp(0));                       // isInvalidDecl
2168   Abv->Add(BitCodeAbbrevOp(0));                       // HasAttrs
2169   Abv->Add(BitCodeAbbrevOp(0));                       // isImplicit
2170   Abv->Add(BitCodeAbbrevOp(0));                       // isUsed
2171   Abv->Add(BitCodeAbbrevOp(0));                       // isReferenced
2172   Abv->Add(BitCodeAbbrevOp(0));                   // TopLevelDeclInObjCContainer
2173   Abv->Add(BitCodeAbbrevOp(AS_none));                 // C++ AccessSpecifier
2174   Abv->Add(BitCodeAbbrevOp(0));                       // ModulePrivate
2175   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // SubmoduleID
2176   // NamedDecl
2177   Abv->Add(BitCodeAbbrevOp(0));                       // NameKind = Identifier
2178   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Name
2179   Abv->Add(BitCodeAbbrevOp(0));                       // AnonDeclNumber
2180   // ValueDecl
2181   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
2182   // DeclaratorDecl
2183   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // InnerStartLoc
2184   Abv->Add(BitCodeAbbrevOp(0));                       // hasExtInfo
2185   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // TSIType
2186   // VarDecl
2187   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); // SClass
2188   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2)); // TSCSpec
2189   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2)); // InitStyle
2190   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isARCPseudoStrong
2191   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsThisDeclarationADemotedDefinition
2192   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isExceptionVariable
2193   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isNRVOVariable
2194   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isCXXForRangeDecl
2195   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isObjCForDecl
2196   Abv->Add(BitCodeAbbrevOp(0));                         // isInline
2197   Abv->Add(BitCodeAbbrevOp(0));                         // isInlineSpecified
2198   Abv->Add(BitCodeAbbrevOp(0));                         // isConstexpr
2199   Abv->Add(BitCodeAbbrevOp(0));                         // isInitCapture
2200   Abv->Add(BitCodeAbbrevOp(0));                         // isPrevDeclInSameScope
2201   Abv->Add(BitCodeAbbrevOp(0));                         // ImplicitParamKind
2202   Abv->Add(BitCodeAbbrevOp(0));                         // EscapingByref
2203   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); // Linkage
2204   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); // IsInitICE (local)
2205   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2)); // VarKind (local enum)
2206   // Type Source Info
2207   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2208   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // TypeLoc
2209   DeclVarAbbrev = Stream.EmitAbbrev(std::move(Abv));
2210 
2211   // Abbreviation for DECL_CXX_METHOD
2212   Abv = std::make_shared<BitCodeAbbrev>();
2213   Abv->Add(BitCodeAbbrevOp(serialization::DECL_CXX_METHOD));
2214   // RedeclarableDecl
2215   Abv->Add(BitCodeAbbrevOp(0));                         // CanonicalDecl
2216   // Decl
2217   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // DeclContext
2218   Abv->Add(BitCodeAbbrevOp(0));                         // LexicalDeclContext
2219   Abv->Add(BitCodeAbbrevOp(0));                         // Invalid
2220   Abv->Add(BitCodeAbbrevOp(0));                         // HasAttrs
2221   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Implicit
2222   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Used
2223   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Referenced
2224   Abv->Add(BitCodeAbbrevOp(0));                         // InObjCContainer
2225   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2)); // Access
2226   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // ModulePrivate
2227   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // SubmoduleID
2228   // NamedDecl
2229   Abv->Add(BitCodeAbbrevOp(DeclarationName::Identifier)); // NameKind
2230   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // Identifier
2231   Abv->Add(BitCodeAbbrevOp(0));                         // AnonDeclNumber
2232   // ValueDecl
2233   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // Type
2234   // DeclaratorDecl
2235   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // InnerLocStart
2236   Abv->Add(BitCodeAbbrevOp(0));                         // HasExtInfo
2237   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // TSIType
2238   // FunctionDecl
2239   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 11)); // IDNS
2240   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); // StorageClass
2241   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Inline
2242   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // InlineSpecified
2243   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // VirtualAsWritten
2244   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Pure
2245   Abv->Add(BitCodeAbbrevOp(0));                         // HasInheritedProto
2246   Abv->Add(BitCodeAbbrevOp(1));                         // HasWrittenProto
2247   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Deleted
2248   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Trivial
2249   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // TrivialForCall
2250   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Defaulted
2251   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // ExplicitlyDefaulted
2252   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // ImplicitReturnZero
2253   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Constexpr
2254   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // UsesSEHTry
2255   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // SkippedBody
2256   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // MultiVersion
2257   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // LateParsed
2258   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); // Linkage
2259   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // LocEnd
2260   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // ODRHash
2261   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); // TemplateKind
2262   // This Array slurps the rest of the record. Fortunately we want to encode
2263   // (nearly) all the remaining (variable number of) fields in the same way.
2264   //
2265   // This is the function template information if any, then
2266   //         NumParams and Params[] from FunctionDecl, and
2267   //         NumOverriddenMethods, OverriddenMethods[] from CXXMethodDecl.
2268   //
2269   //  Add an AbbrevOp for 'size then elements' and use it here.
2270   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2271   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
2272   DeclCXXMethodAbbrev = Stream.EmitAbbrev(std::move(Abv));
2273 
2274   // Abbreviation for EXPR_DECL_REF
2275   Abv = std::make_shared<BitCodeAbbrev>();
2276   Abv->Add(BitCodeAbbrevOp(serialization::EXPR_DECL_REF));
2277   //Stmt
2278   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsOMPStructuredBlock
2279   // Expr
2280   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
2281   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //TypeDependent
2282   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //ValueDependent
2283   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //InstantiationDependent
2284   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //UnexpandedParamPack
2285   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetValueKind
2286   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetObjectKind
2287   //DeclRefExpr
2288   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //HasQualifier
2289   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //GetDeclFound
2290   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //ExplicitTemplateArgs
2291   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //HadMultipleCandidates
2292   Abv->Add(BitCodeAbbrevOp(0)); // RefersToEnclosingVariableOrCapture
2293   Abv->Add(BitCodeAbbrevOp(0)); // NonOdrUseReason
2294   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclRef
2295   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Location
2296   DeclRefExprAbbrev = Stream.EmitAbbrev(std::move(Abv));
2297 
2298   // Abbreviation for EXPR_INTEGER_LITERAL
2299   Abv = std::make_shared<BitCodeAbbrev>();
2300   Abv->Add(BitCodeAbbrevOp(serialization::EXPR_INTEGER_LITERAL));
2301   //Stmt
2302   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsOMPStructuredBlock
2303   // Expr
2304   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
2305   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //TypeDependent
2306   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //ValueDependent
2307   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //InstantiationDependent
2308   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //UnexpandedParamPack
2309   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetValueKind
2310   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetObjectKind
2311   //Integer Literal
2312   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Location
2313   Abv->Add(BitCodeAbbrevOp(32));                      // Bit Width
2314   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Value
2315   IntegerLiteralAbbrev = Stream.EmitAbbrev(std::move(Abv));
2316 
2317   // Abbreviation for EXPR_CHARACTER_LITERAL
2318   Abv = std::make_shared<BitCodeAbbrev>();
2319   Abv->Add(BitCodeAbbrevOp(serialization::EXPR_CHARACTER_LITERAL));
2320   //Stmt
2321   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsOMPStructuredBlock
2322   // Expr
2323   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
2324   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //TypeDependent
2325   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //ValueDependent
2326   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //InstantiationDependent
2327   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //UnexpandedParamPack
2328   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetValueKind
2329   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetObjectKind
2330   //Character Literal
2331   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // getValue
2332   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Location
2333   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); // getKind
2334   CharacterLiteralAbbrev = Stream.EmitAbbrev(std::move(Abv));
2335 
2336   // Abbreviation for EXPR_IMPLICIT_CAST
2337   Abv = std::make_shared<BitCodeAbbrev>();
2338   Abv->Add(BitCodeAbbrevOp(serialization::EXPR_IMPLICIT_CAST));
2339   // Stmt
2340   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsOMPStructuredBlock
2341   // Expr
2342   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
2343   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //TypeDependent
2344   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //ValueDependent
2345   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //InstantiationDependent
2346   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //UnexpandedParamPack
2347   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetValueKind
2348   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetObjectKind
2349   // CastExpr
2350   Abv->Add(BitCodeAbbrevOp(0)); // PathSize
2351   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 6)); // CastKind
2352   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // PartOfExplicitCast
2353   // ImplicitCastExpr
2354   ExprImplicitCastAbbrev = Stream.EmitAbbrev(std::move(Abv));
2355 
2356   Abv = std::make_shared<BitCodeAbbrev>();
2357   Abv->Add(BitCodeAbbrevOp(serialization::DECL_CONTEXT_LEXICAL));
2358   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
2359   DeclContextLexicalAbbrev = Stream.EmitAbbrev(std::move(Abv));
2360 
2361   Abv = std::make_shared<BitCodeAbbrev>();
2362   Abv->Add(BitCodeAbbrevOp(serialization::DECL_CONTEXT_VISIBLE));
2363   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
2364   DeclContextVisibleLookupAbbrev = Stream.EmitAbbrev(std::move(Abv));
2365 }
2366 
2367 /// isRequiredDecl - Check if this is a "required" Decl, which must be seen by
2368 /// consumers of the AST.
2369 ///
2370 /// Such decls will always be deserialized from the AST file, so we would like
2371 /// this to be as restrictive as possible. Currently the predicate is driven by
2372 /// code generation requirements, if other clients have a different notion of
2373 /// what is "required" then we may have to consider an alternate scheme where
2374 /// clients can iterate over the top-level decls and get information on them,
2375 /// without necessary deserializing them. We could explicitly require such
2376 /// clients to use a separate API call to "realize" the decl. This should be
2377 /// relatively painless since they would presumably only do it for top-level
2378 /// decls.
2379 static bool isRequiredDecl(const Decl *D, ASTContext &Context,
2380                            bool WritingModule) {
2381   // An ObjCMethodDecl is never considered as "required" because its
2382   // implementation container always is.
2383 
2384   // File scoped assembly or obj-c or OMP declare target implementation must be
2385   // seen.
2386   if (isa<FileScopeAsmDecl>(D) || isa<ObjCImplDecl>(D))
2387     return true;
2388 
2389   if (WritingModule && isPartOfPerModuleInitializer(D)) {
2390     // These declarations are part of the module initializer, and are emitted
2391     // if and when the module is imported, rather than being emitted eagerly.
2392     return false;
2393   }
2394 
2395   return Context.DeclMustBeEmitted(D);
2396 }
2397 
2398 void ASTWriter::WriteDecl(ASTContext &Context, Decl *D) {
2399   PrettyDeclStackTraceEntry CrashInfo(Context, D, SourceLocation(),
2400                                       "serializing");
2401 
2402   // Determine the ID for this declaration.
2403   serialization::DeclID ID;
2404   assert(!D->isFromASTFile() && "should not be emitting imported decl");
2405   serialization::DeclID &IDR = DeclIDs[D];
2406   if (IDR == 0)
2407     IDR = NextDeclID++;
2408 
2409   ID = IDR;
2410 
2411   assert(ID >= FirstDeclID && "invalid decl ID");
2412 
2413   RecordData Record;
2414   ASTDeclWriter W(*this, Context, Record);
2415 
2416   // Build a record for this declaration
2417   W.Visit(D);
2418 
2419   // Emit this declaration to the bitstream.
2420   uint64_t Offset = W.Emit(D);
2421 
2422   // Record the offset for this declaration
2423   SourceLocation Loc = D->getLocation();
2424   unsigned Index = ID - FirstDeclID;
2425   if (DeclOffsets.size() == Index)
2426     DeclOffsets.push_back(DeclOffset(Loc, Offset));
2427   else if (DeclOffsets.size() < Index) {
2428     // FIXME: Can/should this happen?
2429     DeclOffsets.resize(Index+1);
2430     DeclOffsets[Index].setLocation(Loc);
2431     DeclOffsets[Index].BitOffset = Offset;
2432   } else {
2433     llvm_unreachable("declarations should be emitted in ID order");
2434   }
2435 
2436   SourceManager &SM = Context.getSourceManager();
2437   if (Loc.isValid() && SM.isLocalSourceLocation(Loc))
2438     associateDeclWithFile(D, ID);
2439 
2440   // Note declarations that should be deserialized eagerly so that we can add
2441   // them to a record in the AST file later.
2442   if (isRequiredDecl(D, Context, WritingModule))
2443     EagerlyDeserializedDecls.push_back(ID);
2444 }
2445 
2446 void ASTRecordWriter::AddFunctionDefinition(const FunctionDecl *FD) {
2447   // Switch case IDs are per function body.
2448   Writer->ClearSwitchCaseIDs();
2449 
2450   assert(FD->doesThisDeclarationHaveABody());
2451   bool ModulesCodegen = false;
2452   if (!FD->isDependentContext()) {
2453     Optional<GVALinkage> Linkage;
2454     if ((Writer->WritingModule &&
2455          Writer->WritingModule->Kind == Module::ModuleInterfaceUnit) ||
2456         Writer->Context->getLangOpts().BuildingPCHWithObjectFile) {
2457       // When building a C++ Modules TS module interface unit, a strong
2458       // definition in the module interface is provided by the compilation of
2459       // that module interface unit, not by its users. (Inline functions are
2460       // still emitted in module users.)
2461       Linkage = Writer->Context->GetGVALinkageForFunction(FD);
2462       ModulesCodegen = *Linkage == GVA_StrongExternal;
2463     }
2464     if (Writer->Context->getLangOpts().ModulesCodegen) {
2465       // Under -fmodules-codegen, codegen is performed for all non-internal,
2466       // non-always_inline functions, unless they are available elsewhere.
2467       if (!FD->hasAttr<AlwaysInlineAttr>()) {
2468         if (!Linkage)
2469           Linkage = Writer->Context->GetGVALinkageForFunction(FD);
2470         ModulesCodegen =
2471             *Linkage != GVA_Internal && *Linkage != GVA_AvailableExternally;
2472       }
2473     }
2474   }
2475   Record->push_back(ModulesCodegen);
2476   if (ModulesCodegen)
2477     Writer->ModularCodegenDecls.push_back(Writer->GetDeclRef(FD));
2478   if (auto *CD = dyn_cast<CXXConstructorDecl>(FD)) {
2479     Record->push_back(CD->getNumCtorInitializers());
2480     if (CD->getNumCtorInitializers())
2481       AddCXXCtorInitializers(
2482           llvm::makeArrayRef(CD->init_begin(), CD->init_end()));
2483   }
2484   AddStmt(FD->getBody());
2485 }
2486