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