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