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