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