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