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