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