1 //===--- ASTWriterDecl.cpp - Declaration Serialization --------------------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 //  This file implements serialization for Declarations.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "clang/Serialization/ASTWriter.h"
15 #include "clang/Serialization/ASTReader.h"
16 #include "ASTCommon.h"
17 #include "clang/AST/DeclVisitor.h"
18 #include "clang/AST/DeclCXX.h"
19 #include "clang/AST/DeclTemplate.h"
20 #include "clang/AST/Expr.h"
21 #include "clang/AST/DeclContextInternals.h"
22 #include "clang/Basic/SourceManager.h"
23 #include "llvm/ADT/Twine.h"
24 #include "llvm/Bitcode/BitstreamWriter.h"
25 #include "llvm/Support/ErrorHandling.h"
26 using namespace clang;
27 using namespace serialization;
28 
29 //===----------------------------------------------------------------------===//
30 // Declaration serialization
31 //===----------------------------------------------------------------------===//
32 
33 namespace clang {
34   class ASTDeclWriter : public DeclVisitor<ASTDeclWriter, void> {
35 
36     ASTWriter &Writer;
37     ASTContext &Context;
38     typedef ASTWriter::RecordData RecordData;
39     RecordData &Record;
40 
41   public:
42     serialization::DeclCode Code;
43     unsigned AbbrevToUse;
44 
45     ASTDeclWriter(ASTWriter &Writer, ASTContext &Context, RecordData &Record)
46       : Writer(Writer), Context(Context), Record(Record) {
47     }
48 
49     void Visit(Decl *D);
50 
51     void VisitDecl(Decl *D);
52     void VisitTranslationUnitDecl(TranslationUnitDecl *D);
53     void VisitNamedDecl(NamedDecl *D);
54     void VisitLabelDecl(LabelDecl *LD);
55     void VisitNamespaceDecl(NamespaceDecl *D);
56     void VisitUsingDirectiveDecl(UsingDirectiveDecl *D);
57     void VisitNamespaceAliasDecl(NamespaceAliasDecl *D);
58     void VisitTypeDecl(TypeDecl *D);
59     void VisitTypedefNameDecl(TypedefNameDecl *D);
60     void VisitTypedefDecl(TypedefDecl *D);
61     void VisitTypeAliasDecl(TypeAliasDecl *D);
62     void VisitUnresolvedUsingTypenameDecl(UnresolvedUsingTypenameDecl *D);
63     void VisitTagDecl(TagDecl *D);
64     void VisitEnumDecl(EnumDecl *D);
65     void VisitRecordDecl(RecordDecl *D);
66     void VisitCXXRecordDecl(CXXRecordDecl *D);
67     void VisitClassTemplateSpecializationDecl(
68                                             ClassTemplateSpecializationDecl *D);
69     void VisitClassTemplatePartialSpecializationDecl(
70                                      ClassTemplatePartialSpecializationDecl *D);
71     void VisitClassScopeFunctionSpecializationDecl(
72                                        ClassScopeFunctionSpecializationDecl *D);
73     void VisitTemplateTypeParmDecl(TemplateTypeParmDecl *D);
74     void VisitValueDecl(ValueDecl *D);
75     void VisitEnumConstantDecl(EnumConstantDecl *D);
76     void VisitUnresolvedUsingValueDecl(UnresolvedUsingValueDecl *D);
77     void VisitDeclaratorDecl(DeclaratorDecl *D);
78     void VisitFunctionDecl(FunctionDecl *D);
79     void VisitCXXMethodDecl(CXXMethodDecl *D);
80     void VisitCXXConstructorDecl(CXXConstructorDecl *D);
81     void VisitCXXDestructorDecl(CXXDestructorDecl *D);
82     void VisitCXXConversionDecl(CXXConversionDecl *D);
83     void VisitFieldDecl(FieldDecl *D);
84     void VisitIndirectFieldDecl(IndirectFieldDecl *D);
85     void VisitVarDecl(VarDecl *D);
86     void VisitImplicitParamDecl(ImplicitParamDecl *D);
87     void VisitParmVarDecl(ParmVarDecl *D);
88     void VisitNonTypeTemplateParmDecl(NonTypeTemplateParmDecl *D);
89     void VisitTemplateDecl(TemplateDecl *D);
90     void VisitRedeclarableTemplateDecl(RedeclarableTemplateDecl *D);
91     void VisitClassTemplateDecl(ClassTemplateDecl *D);
92     void VisitFunctionTemplateDecl(FunctionTemplateDecl *D);
93     void VisitTemplateTemplateParmDecl(TemplateTemplateParmDecl *D);
94     void VisitTypeAliasTemplateDecl(TypeAliasTemplateDecl *D);
95     void VisitUsingDecl(UsingDecl *D);
96     void VisitUsingShadowDecl(UsingShadowDecl *D);
97     void VisitLinkageSpecDecl(LinkageSpecDecl *D);
98     void VisitFileScopeAsmDecl(FileScopeAsmDecl *D);
99     void VisitImportDecl(ImportDecl *D);
100     void VisitAccessSpecDecl(AccessSpecDecl *D);
101     void VisitFriendDecl(FriendDecl *D);
102     void VisitFriendTemplateDecl(FriendTemplateDecl *D);
103     void VisitStaticAssertDecl(StaticAssertDecl *D);
104     void VisitBlockDecl(BlockDecl *D);
105 
106     void VisitDeclContext(DeclContext *DC, uint64_t LexicalOffset,
107                           uint64_t VisibleOffset);
108     template <typename T> void VisitRedeclarable(Redeclarable<T> *D);
109 
110 
111     // FIXME: Put in the same order is DeclNodes.td?
112     void VisitObjCMethodDecl(ObjCMethodDecl *D);
113     void VisitObjCContainerDecl(ObjCContainerDecl *D);
114     void VisitObjCInterfaceDecl(ObjCInterfaceDecl *D);
115     void VisitObjCIvarDecl(ObjCIvarDecl *D);
116     void VisitObjCProtocolDecl(ObjCProtocolDecl *D);
117     void VisitObjCAtDefsFieldDecl(ObjCAtDefsFieldDecl *D);
118     void VisitObjCCategoryDecl(ObjCCategoryDecl *D);
119     void VisitObjCImplDecl(ObjCImplDecl *D);
120     void VisitObjCCategoryImplDecl(ObjCCategoryImplDecl *D);
121     void VisitObjCImplementationDecl(ObjCImplementationDecl *D);
122     void VisitObjCCompatibleAliasDecl(ObjCCompatibleAliasDecl *D);
123     void VisitObjCPropertyDecl(ObjCPropertyDecl *D);
124     void VisitObjCPropertyImplDecl(ObjCPropertyImplDecl *D);
125   };
126 }
127 
128 void ASTDeclWriter::Visit(Decl *D) {
129   DeclVisitor<ASTDeclWriter>::Visit(D);
130 
131   // Source locations require array (variable-length) abbreviations.  The
132   // abbreviation infrastructure requires that arrays are encoded last, so
133   // we handle it here in the case of those classes derived from DeclaratorDecl
134   if (DeclaratorDecl *DD = dyn_cast<DeclaratorDecl>(D)){
135     Writer.AddTypeSourceInfo(DD->getTypeSourceInfo(), Record);
136   }
137 
138   // Handle FunctionDecl's body here and write it after all other Stmts/Exprs
139   // have been written. We want it last because we will not read it back when
140   // retrieving it from the AST, we'll just lazily set the offset.
141   if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
142     Record.push_back(FD->doesThisDeclarationHaveABody());
143     if (FD->doesThisDeclarationHaveABody())
144       Writer.AddStmt(FD->getBody());
145   }
146 }
147 
148 void ASTDeclWriter::VisitDecl(Decl *D) {
149   Writer.AddDeclRef(cast_or_null<Decl>(D->getDeclContext()), Record);
150   Writer.AddDeclRef(cast_or_null<Decl>(D->getLexicalDeclContext()), Record);
151   Record.push_back(D->isInvalidDecl());
152   Record.push_back(D->hasAttrs());
153   if (D->hasAttrs())
154     Writer.WriteAttributes(ArrayRef<const Attr*>(D->getAttrs().begin(),
155                                                  D->getAttrs().size()), Record);
156   Record.push_back(D->isImplicit());
157   Record.push_back(D->isUsed(false));
158   Record.push_back(D->isReferenced());
159   Record.push_back(D->isTopLevelDeclInObjCContainer());
160   Record.push_back(D->getAccess());
161   Record.push_back(D->isModulePrivate());
162   Record.push_back(Writer.inferSubmoduleIDFromLocation(D->getLocation()));
163 }
164 
165 void ASTDeclWriter::VisitTranslationUnitDecl(TranslationUnitDecl *D) {
166   llvm_unreachable("Translation units aren't directly serialized");
167 }
168 
169 void ASTDeclWriter::VisitNamedDecl(NamedDecl *D) {
170   VisitDecl(D);
171   Writer.AddDeclarationName(D->getDeclName(), Record);
172 }
173 
174 void ASTDeclWriter::VisitTypeDecl(TypeDecl *D) {
175   VisitNamedDecl(D);
176   Writer.AddSourceLocation(D->getLocStart(), Record);
177   Writer.AddTypeRef(QualType(D->getTypeForDecl(), 0), Record);
178 }
179 
180 void ASTDeclWriter::VisitTypedefNameDecl(TypedefNameDecl *D) {
181   VisitRedeclarable(D);
182   VisitTypeDecl(D);
183   Writer.AddTypeSourceInfo(D->getTypeSourceInfo(), Record);
184 }
185 
186 void ASTDeclWriter::VisitTypedefDecl(TypedefDecl *D) {
187   VisitTypedefNameDecl(D);
188   if (!D->hasAttrs() &&
189       !D->isImplicit() &&
190       !D->isUsed(false) &&
191       D->getFirstDeclaration() == D->getMostRecentDecl() &&
192       !D->isInvalidDecl() &&
193       !D->isReferenced() &&
194       !D->isTopLevelDeclInObjCContainer() &&
195       D->getAccess() == AS_none &&
196       !D->isModulePrivate() &&
197       D->getDeclName().getNameKind() == DeclarationName::Identifier)
198     AbbrevToUse = Writer.getDeclTypedefAbbrev();
199 
200   Code = serialization::DECL_TYPEDEF;
201 }
202 
203 void ASTDeclWriter::VisitTypeAliasDecl(TypeAliasDecl *D) {
204   VisitTypedefNameDecl(D);
205   Code = serialization::DECL_TYPEALIAS;
206 }
207 
208 void ASTDeclWriter::VisitTagDecl(TagDecl *D) {
209   VisitRedeclarable(D);
210   VisitTypeDecl(D);
211   Record.push_back(D->getIdentifierNamespace());
212   Record.push_back((unsigned)D->getTagKind()); // FIXME: stable encoding
213   Record.push_back(D->isCompleteDefinition());
214   Record.push_back(D->isEmbeddedInDeclarator());
215   Record.push_back(D->isFreeStanding());
216   Writer.AddSourceLocation(D->getRBraceLoc(), Record);
217   Record.push_back(D->hasExtInfo());
218   if (D->hasExtInfo())
219     Writer.AddQualifierInfo(*D->getExtInfo(), Record);
220   else
221     Writer.AddDeclRef(D->getTypedefNameForAnonDecl(), Record);
222 }
223 
224 void ASTDeclWriter::VisitEnumDecl(EnumDecl *D) {
225   VisitTagDecl(D);
226   Writer.AddTypeSourceInfo(D->getIntegerTypeSourceInfo(), Record);
227   if (!D->getIntegerTypeSourceInfo())
228     Writer.AddTypeRef(D->getIntegerType(), Record);
229   Writer.AddTypeRef(D->getPromotionType(), Record);
230   Record.push_back(D->getNumPositiveBits());
231   Record.push_back(D->getNumNegativeBits());
232   Record.push_back(D->isScoped());
233   Record.push_back(D->isScopedUsingClassTag());
234   Record.push_back(D->isFixed());
235   if (MemberSpecializationInfo *MemberInfo = D->getMemberSpecializationInfo()) {
236     Writer.AddDeclRef(MemberInfo->getInstantiatedFrom(), Record);
237     Record.push_back(MemberInfo->getTemplateSpecializationKind());
238     Writer.AddSourceLocation(MemberInfo->getPointOfInstantiation(), Record);
239   } else {
240     Writer.AddDeclRef(0, Record);
241   }
242 
243   if (!D->hasAttrs() &&
244       !D->isImplicit() &&
245       !D->isUsed(false) &&
246       !D->hasExtInfo() &&
247       D->getFirstDeclaration() == D->getMostRecentDecl() &&
248       !D->isInvalidDecl() &&
249       !D->isReferenced() &&
250       !D->isTopLevelDeclInObjCContainer() &&
251       D->getAccess() == AS_none &&
252       !D->isModulePrivate() &&
253       !CXXRecordDecl::classofKind(D->getKind()) &&
254       !D->getIntegerTypeSourceInfo() &&
255       D->getDeclName().getNameKind() == DeclarationName::Identifier)
256     AbbrevToUse = Writer.getDeclEnumAbbrev();
257 
258   Code = serialization::DECL_ENUM;
259 }
260 
261 void ASTDeclWriter::VisitRecordDecl(RecordDecl *D) {
262   VisitTagDecl(D);
263   Record.push_back(D->hasFlexibleArrayMember());
264   Record.push_back(D->isAnonymousStructOrUnion());
265   Record.push_back(D->hasObjectMember());
266 
267   if (!D->hasAttrs() &&
268       !D->isImplicit() &&
269       !D->isUsed(false) &&
270       !D->hasExtInfo() &&
271       D->getFirstDeclaration() == D->getMostRecentDecl() &&
272       !D->isInvalidDecl() &&
273       !D->isReferenced() &&
274       !D->isTopLevelDeclInObjCContainer() &&
275       D->getAccess() == AS_none &&
276       !D->isModulePrivate() &&
277       !CXXRecordDecl::classofKind(D->getKind()) &&
278       D->getDeclName().getNameKind() == DeclarationName::Identifier)
279     AbbrevToUse = Writer.getDeclRecordAbbrev();
280 
281   Code = serialization::DECL_RECORD;
282 }
283 
284 void ASTDeclWriter::VisitValueDecl(ValueDecl *D) {
285   VisitNamedDecl(D);
286   Writer.AddTypeRef(D->getType(), Record);
287 }
288 
289 void ASTDeclWriter::VisitEnumConstantDecl(EnumConstantDecl *D) {
290   VisitValueDecl(D);
291   Record.push_back(D->getInitExpr()? 1 : 0);
292   if (D->getInitExpr())
293     Writer.AddStmt(D->getInitExpr());
294   Writer.AddAPSInt(D->getInitVal(), Record);
295 
296   Code = serialization::DECL_ENUM_CONSTANT;
297 }
298 
299 void ASTDeclWriter::VisitDeclaratorDecl(DeclaratorDecl *D) {
300   VisitValueDecl(D);
301   Writer.AddSourceLocation(D->getInnerLocStart(), Record);
302   Record.push_back(D->hasExtInfo());
303   if (D->hasExtInfo())
304     Writer.AddQualifierInfo(*D->getExtInfo(), Record);
305 }
306 
307 void ASTDeclWriter::VisitFunctionDecl(FunctionDecl *D) {
308   VisitRedeclarable(D);
309   VisitDeclaratorDecl(D);
310 
311   Writer.AddDeclarationNameLoc(D->DNLoc, D->getDeclName(), Record);
312   Record.push_back(D->getIdentifierNamespace());
313 
314   // FunctionDecl's body is handled last at ASTWriterDecl::Visit,
315   // after everything else is written.
316 
317   Record.push_back(D->getStorageClass()); // FIXME: stable encoding
318   Record.push_back(D->getStorageClassAsWritten());
319   Record.push_back(D->IsInline);
320   Record.push_back(D->isInlineSpecified());
321   Record.push_back(D->isVirtualAsWritten());
322   Record.push_back(D->isPure());
323   Record.push_back(D->hasInheritedPrototype());
324   Record.push_back(D->hasWrittenPrototype());
325   Record.push_back(D->isDeletedAsWritten());
326   Record.push_back(D->isTrivial());
327   Record.push_back(D->isDefaulted());
328   Record.push_back(D->isExplicitlyDefaulted());
329   Record.push_back(D->hasImplicitReturnZero());
330   Record.push_back(D->isConstexpr());
331   Writer.AddSourceLocation(D->getLocEnd(), Record);
332 
333   Record.push_back(D->getTemplatedKind());
334   switch (D->getTemplatedKind()) {
335   case FunctionDecl::TK_NonTemplate:
336     break;
337   case FunctionDecl::TK_FunctionTemplate:
338     Writer.AddDeclRef(D->getDescribedFunctionTemplate(), Record);
339     break;
340   case FunctionDecl::TK_MemberSpecialization: {
341     MemberSpecializationInfo *MemberInfo = D->getMemberSpecializationInfo();
342     Writer.AddDeclRef(MemberInfo->getInstantiatedFrom(), Record);
343     Record.push_back(MemberInfo->getTemplateSpecializationKind());
344     Writer.AddSourceLocation(MemberInfo->getPointOfInstantiation(), Record);
345     break;
346   }
347   case FunctionDecl::TK_FunctionTemplateSpecialization: {
348     FunctionTemplateSpecializationInfo *
349       FTSInfo = D->getTemplateSpecializationInfo();
350     Writer.AddDeclRef(FTSInfo->getTemplate(), Record);
351     Record.push_back(FTSInfo->getTemplateSpecializationKind());
352 
353     // Template arguments.
354     Writer.AddTemplateArgumentList(FTSInfo->TemplateArguments, Record);
355 
356     // Template args as written.
357     Record.push_back(FTSInfo->TemplateArgumentsAsWritten != 0);
358     if (FTSInfo->TemplateArgumentsAsWritten) {
359       Record.push_back(FTSInfo->TemplateArgumentsAsWritten->NumTemplateArgs);
360       for (int i=0, e = FTSInfo->TemplateArgumentsAsWritten->NumTemplateArgs;
361              i!=e; ++i)
362         Writer.AddTemplateArgumentLoc((*FTSInfo->TemplateArgumentsAsWritten)[i],
363                                       Record);
364       Writer.AddSourceLocation(FTSInfo->TemplateArgumentsAsWritten->LAngleLoc,
365                                Record);
366       Writer.AddSourceLocation(FTSInfo->TemplateArgumentsAsWritten->RAngleLoc,
367                                Record);
368     }
369 
370     Writer.AddSourceLocation(FTSInfo->getPointOfInstantiation(), Record);
371 
372     if (D->isCanonicalDecl()) {
373       // Write the template that contains the specializations set. We will
374       // add a FunctionTemplateSpecializationInfo to it when reading.
375       Writer.AddDeclRef(FTSInfo->getTemplate()->getCanonicalDecl(), Record);
376     }
377     break;
378   }
379   case FunctionDecl::TK_DependentFunctionTemplateSpecialization: {
380     DependentFunctionTemplateSpecializationInfo *
381       DFTSInfo = D->getDependentSpecializationInfo();
382 
383     // Templates.
384     Record.push_back(DFTSInfo->getNumTemplates());
385     for (int i=0, e = DFTSInfo->getNumTemplates(); i != e; ++i)
386       Writer.AddDeclRef(DFTSInfo->getTemplate(i), Record);
387 
388     // Templates args.
389     Record.push_back(DFTSInfo->getNumTemplateArgs());
390     for (int i=0, e = DFTSInfo->getNumTemplateArgs(); i != e; ++i)
391       Writer.AddTemplateArgumentLoc(DFTSInfo->getTemplateArg(i), Record);
392     Writer.AddSourceLocation(DFTSInfo->getLAngleLoc(), Record);
393     Writer.AddSourceLocation(DFTSInfo->getRAngleLoc(), Record);
394     break;
395   }
396   }
397 
398   Record.push_back(D->param_size());
399   for (FunctionDecl::param_iterator P = D->param_begin(), PEnd = D->param_end();
400        P != PEnd; ++P)
401     Writer.AddDeclRef(*P, Record);
402   Code = serialization::DECL_FUNCTION;
403 }
404 
405 void ASTDeclWriter::VisitObjCMethodDecl(ObjCMethodDecl *D) {
406   VisitNamedDecl(D);
407   // FIXME: convert to LazyStmtPtr?
408   // Unlike C/C++, method bodies will never be in header files.
409   bool HasBodyStuff = D->getBody() != 0     ||
410                       D->getSelfDecl() != 0 || D->getCmdDecl() != 0;
411   Record.push_back(HasBodyStuff);
412   if (HasBodyStuff) {
413     Writer.AddStmt(D->getBody());
414     Writer.AddDeclRef(D->getSelfDecl(), Record);
415     Writer.AddDeclRef(D->getCmdDecl(), Record);
416   }
417   Record.push_back(D->isInstanceMethod());
418   Record.push_back(D->isVariadic());
419   Record.push_back(D->isSynthesized());
420   Record.push_back(D->isDefined());
421   Record.push_back(D->IsOverriding);
422 
423   Record.push_back(D->IsRedeclaration);
424   Record.push_back(D->HasRedeclaration);
425   if (D->HasRedeclaration) {
426     assert(Context.getObjCMethodRedeclaration(D));
427     Writer.AddDeclRef(Context.getObjCMethodRedeclaration(D), Record);
428   }
429 
430   // FIXME: stable encoding for @required/@optional
431   Record.push_back(D->getImplementationControl());
432   // FIXME: stable encoding for in/out/inout/bycopy/byref/oneway
433   Record.push_back(D->getObjCDeclQualifier());
434   Record.push_back(D->hasRelatedResultType());
435   Writer.AddTypeRef(D->getResultType(), Record);
436   Writer.AddTypeSourceInfo(D->getResultTypeSourceInfo(), Record);
437   Writer.AddSourceLocation(D->getLocEnd(), Record);
438   Record.push_back(D->param_size());
439   for (ObjCMethodDecl::param_iterator P = D->param_begin(),
440                                    PEnd = D->param_end(); P != PEnd; ++P)
441     Writer.AddDeclRef(*P, Record);
442 
443   Record.push_back(D->SelLocsKind);
444   unsigned NumStoredSelLocs = D->getNumStoredSelLocs();
445   SourceLocation *SelLocs = D->getStoredSelLocs();
446   Record.push_back(NumStoredSelLocs);
447   for (unsigned i = 0; i != NumStoredSelLocs; ++i)
448     Writer.AddSourceLocation(SelLocs[i], Record);
449 
450   Code = serialization::DECL_OBJC_METHOD;
451 }
452 
453 void ASTDeclWriter::VisitObjCContainerDecl(ObjCContainerDecl *D) {
454   VisitNamedDecl(D);
455   Writer.AddSourceLocation(D->getAtStartLoc(), Record);
456   Writer.AddSourceRange(D->getAtEndRange(), Record);
457   // Abstract class (no need to define a stable serialization::DECL code).
458 }
459 
460 void ASTDeclWriter::VisitObjCInterfaceDecl(ObjCInterfaceDecl *D) {
461   VisitRedeclarable(D);
462   VisitObjCContainerDecl(D);
463   Writer.AddTypeRef(QualType(D->getTypeForDecl(), 0), Record);
464 
465   Record.push_back(D->isThisDeclarationADefinition());
466   if (D->isThisDeclarationADefinition()) {
467     // Write the DefinitionData
468     ObjCInterfaceDecl::DefinitionData &Data = D->data();
469 
470     Writer.AddDeclRef(D->getSuperClass(), Record);
471     Writer.AddSourceLocation(D->getSuperClassLoc(), Record);
472     Writer.AddSourceLocation(D->getEndOfDefinitionLoc(), Record);
473 
474     // Write out the protocols that are directly referenced by the @interface.
475     Record.push_back(Data.ReferencedProtocols.size());
476     for (ObjCInterfaceDecl::protocol_iterator P = D->protocol_begin(),
477                                            PEnd = D->protocol_end();
478          P != PEnd; ++P)
479       Writer.AddDeclRef(*P, Record);
480     for (ObjCInterfaceDecl::protocol_loc_iterator PL = D->protocol_loc_begin(),
481          PLEnd = D->protocol_loc_end();
482          PL != PLEnd; ++PL)
483       Writer.AddSourceLocation(*PL, Record);
484 
485     // Write out the protocols that are transitively referenced.
486     Record.push_back(Data.AllReferencedProtocols.size());
487     for (ObjCList<ObjCProtocolDecl>::iterator
488               P = Data.AllReferencedProtocols.begin(),
489            PEnd = Data.AllReferencedProtocols.end();
490          P != PEnd; ++P)
491       Writer.AddDeclRef(*P, Record);
492 
493     if (ObjCCategoryDecl *Cat = D->getCategoryList()) {
494       // Ensure that we write out the set of categories for this class.
495       Writer.ObjCClassesWithCategories.insert(D);
496 
497       // Make sure that the categories get serialized.
498       for (; Cat; Cat = Cat->getNextClassCategory())
499         (void)Writer.GetDeclRef(Cat);
500     }
501   }
502 
503   Code = serialization::DECL_OBJC_INTERFACE;
504 }
505 
506 void ASTDeclWriter::VisitObjCIvarDecl(ObjCIvarDecl *D) {
507   VisitFieldDecl(D);
508   // FIXME: stable encoding for @public/@private/@protected/@package
509   Record.push_back(D->getAccessControl());
510   Record.push_back(D->getSynthesize());
511 
512   if (!D->hasAttrs() &&
513       !D->isImplicit() &&
514       !D->isUsed(false) &&
515       !D->isInvalidDecl() &&
516       !D->isReferenced() &&
517       !D->isModulePrivate() &&
518       !D->getBitWidth() &&
519       !D->hasExtInfo() &&
520       D->getDeclName())
521     AbbrevToUse = Writer.getDeclObjCIvarAbbrev();
522 
523   Code = serialization::DECL_OBJC_IVAR;
524 }
525 
526 void ASTDeclWriter::VisitObjCProtocolDecl(ObjCProtocolDecl *D) {
527   VisitRedeclarable(D);
528   VisitObjCContainerDecl(D);
529 
530   Record.push_back(D->isThisDeclarationADefinition());
531   if (D->isThisDeclarationADefinition()) {
532     Record.push_back(D->protocol_size());
533     for (ObjCProtocolDecl::protocol_iterator
534          I = D->protocol_begin(), IEnd = D->protocol_end(); I != IEnd; ++I)
535       Writer.AddDeclRef(*I, Record);
536     for (ObjCProtocolDecl::protocol_loc_iterator PL = D->protocol_loc_begin(),
537            PLEnd = D->protocol_loc_end();
538          PL != PLEnd; ++PL)
539       Writer.AddSourceLocation(*PL, Record);
540   }
541 
542   Code = serialization::DECL_OBJC_PROTOCOL;
543 }
544 
545 void ASTDeclWriter::VisitObjCAtDefsFieldDecl(ObjCAtDefsFieldDecl *D) {
546   VisitFieldDecl(D);
547   Code = serialization::DECL_OBJC_AT_DEFS_FIELD;
548 }
549 
550 void ASTDeclWriter::VisitObjCCategoryDecl(ObjCCategoryDecl *D) {
551   VisitObjCContainerDecl(D);
552   Writer.AddSourceLocation(D->getCategoryNameLoc(), Record);
553   Writer.AddSourceLocation(D->getIvarLBraceLoc(), Record);
554   Writer.AddSourceLocation(D->getIvarRBraceLoc(), Record);
555   Writer.AddDeclRef(D->getClassInterface(), Record);
556   Record.push_back(D->protocol_size());
557   for (ObjCCategoryDecl::protocol_iterator
558        I = D->protocol_begin(), IEnd = D->protocol_end(); I != IEnd; ++I)
559     Writer.AddDeclRef(*I, Record);
560   for (ObjCCategoryDecl::protocol_loc_iterator
561          PL = D->protocol_loc_begin(), PLEnd = D->protocol_loc_end();
562        PL != PLEnd; ++PL)
563     Writer.AddSourceLocation(*PL, Record);
564   Code = serialization::DECL_OBJC_CATEGORY;
565 }
566 
567 void ASTDeclWriter::VisitObjCCompatibleAliasDecl(ObjCCompatibleAliasDecl *D) {
568   VisitNamedDecl(D);
569   Writer.AddDeclRef(D->getClassInterface(), Record);
570   Code = serialization::DECL_OBJC_COMPATIBLE_ALIAS;
571 }
572 
573 void ASTDeclWriter::VisitObjCPropertyDecl(ObjCPropertyDecl *D) {
574   VisitNamedDecl(D);
575   Writer.AddSourceLocation(D->getAtLoc(), Record);
576   Writer.AddSourceLocation(D->getLParenLoc(), Record);
577   Writer.AddTypeSourceInfo(D->getTypeSourceInfo(), Record);
578   // FIXME: stable encoding
579   Record.push_back((unsigned)D->getPropertyAttributes());
580   Record.push_back((unsigned)D->getPropertyAttributesAsWritten());
581   // FIXME: stable encoding
582   Record.push_back((unsigned)D->getPropertyImplementation());
583   Writer.AddDeclarationName(D->getGetterName(), Record);
584   Writer.AddDeclarationName(D->getSetterName(), Record);
585   Writer.AddDeclRef(D->getGetterMethodDecl(), Record);
586   Writer.AddDeclRef(D->getSetterMethodDecl(), Record);
587   Writer.AddDeclRef(D->getPropertyIvarDecl(), Record);
588   Code = serialization::DECL_OBJC_PROPERTY;
589 }
590 
591 void ASTDeclWriter::VisitObjCImplDecl(ObjCImplDecl *D) {
592   VisitObjCContainerDecl(D);
593   Writer.AddDeclRef(D->getClassInterface(), Record);
594   // Abstract class (no need to define a stable serialization::DECL code).
595 }
596 
597 void ASTDeclWriter::VisitObjCCategoryImplDecl(ObjCCategoryImplDecl *D) {
598   VisitObjCImplDecl(D);
599   Writer.AddIdentifierRef(D->getIdentifier(), Record);
600   Writer.AddSourceLocation(D->getCategoryNameLoc(), Record);
601   Code = serialization::DECL_OBJC_CATEGORY_IMPL;
602 }
603 
604 void ASTDeclWriter::VisitObjCImplementationDecl(ObjCImplementationDecl *D) {
605   VisitObjCImplDecl(D);
606   Writer.AddDeclRef(D->getSuperClass(), Record);
607   Writer.AddSourceLocation(D->getIvarLBraceLoc(), Record);
608   Writer.AddSourceLocation(D->getIvarRBraceLoc(), Record);
609   Writer.AddCXXCtorInitializers(D->IvarInitializers, D->NumIvarInitializers,
610                                 Record);
611   Code = serialization::DECL_OBJC_IMPLEMENTATION;
612 }
613 
614 void ASTDeclWriter::VisitObjCPropertyImplDecl(ObjCPropertyImplDecl *D) {
615   VisitDecl(D);
616   Writer.AddSourceLocation(D->getLocStart(), Record);
617   Writer.AddDeclRef(D->getPropertyDecl(), Record);
618   Writer.AddDeclRef(D->getPropertyIvarDecl(), Record);
619   Writer.AddSourceLocation(D->getPropertyIvarDeclLoc(), Record);
620   Writer.AddStmt(D->getGetterCXXConstructor());
621   Writer.AddStmt(D->getSetterCXXAssignment());
622   Code = serialization::DECL_OBJC_PROPERTY_IMPL;
623 }
624 
625 void ASTDeclWriter::VisitFieldDecl(FieldDecl *D) {
626   VisitDeclaratorDecl(D);
627   Record.push_back(D->isMutable());
628   if (D->InitializerOrBitWidth.getInt() != ICIS_NoInit ||
629       D->InitializerOrBitWidth.getPointer()) {
630     Record.push_back(D->InitializerOrBitWidth.getInt() + 1);
631     Writer.AddStmt(D->InitializerOrBitWidth.getPointer());
632   } else {
633     Record.push_back(0);
634   }
635   if (!D->getDeclName())
636     Writer.AddDeclRef(Context.getInstantiatedFromUnnamedFieldDecl(D), Record);
637 
638   if (!D->hasAttrs() &&
639       !D->isImplicit() &&
640       !D->isUsed(false) &&
641       !D->isInvalidDecl() &&
642       !D->isReferenced() &&
643       !D->isTopLevelDeclInObjCContainer() &&
644       !D->isModulePrivate() &&
645       !D->getBitWidth() &&
646       !D->hasInClassInitializer() &&
647       !D->hasExtInfo() &&
648       !ObjCIvarDecl::classofKind(D->getKind()) &&
649       !ObjCAtDefsFieldDecl::classofKind(D->getKind()) &&
650       D->getDeclName())
651     AbbrevToUse = Writer.getDeclFieldAbbrev();
652 
653   Code = serialization::DECL_FIELD;
654 }
655 
656 void ASTDeclWriter::VisitIndirectFieldDecl(IndirectFieldDecl *D) {
657   VisitValueDecl(D);
658   Record.push_back(D->getChainingSize());
659 
660   for (IndirectFieldDecl::chain_iterator
661        P = D->chain_begin(),
662        PEnd = D->chain_end(); P != PEnd; ++P)
663     Writer.AddDeclRef(*P, Record);
664   Code = serialization::DECL_INDIRECTFIELD;
665 }
666 
667 void ASTDeclWriter::VisitVarDecl(VarDecl *D) {
668   VisitRedeclarable(D);
669   VisitDeclaratorDecl(D);
670   Record.push_back(D->getStorageClass()); // FIXME: stable encoding
671   Record.push_back(D->getStorageClassAsWritten());
672   Record.push_back(D->isThreadSpecified());
673   Record.push_back(D->getInitStyle());
674   Record.push_back(D->isExceptionVariable());
675   Record.push_back(D->isNRVOVariable());
676   Record.push_back(D->isCXXForRangeDecl());
677   Record.push_back(D->isARCPseudoStrong());
678   Record.push_back(D->isConstexpr());
679 
680   if (D->getInit()) {
681     Record.push_back(!D->isInitKnownICE() ? 1 : (D->isInitICE() ? 3 : 2));
682     Writer.AddStmt(D->getInit());
683   } else {
684     Record.push_back(0);
685   }
686 
687   MemberSpecializationInfo *SpecInfo
688     = D->isStaticDataMember() ? D->getMemberSpecializationInfo() : 0;
689   Record.push_back(SpecInfo != 0);
690   if (SpecInfo) {
691     Writer.AddDeclRef(SpecInfo->getInstantiatedFrom(), Record);
692     Record.push_back(SpecInfo->getTemplateSpecializationKind());
693     Writer.AddSourceLocation(SpecInfo->getPointOfInstantiation(), Record);
694   }
695 
696   if (!D->hasAttrs() &&
697       !D->isImplicit() &&
698       !D->isUsed(false) &&
699       !D->isInvalidDecl() &&
700       !D->isReferenced() &&
701       !D->isTopLevelDeclInObjCContainer() &&
702       D->getAccess() == AS_none &&
703       !D->isModulePrivate() &&
704       D->getDeclName().getNameKind() == DeclarationName::Identifier &&
705       !D->hasExtInfo() &&
706       D->getFirstDeclaration() == D->getMostRecentDecl() &&
707       D->getInitStyle() == VarDecl::CInit &&
708       D->getInit() == 0 &&
709       !isa<ParmVarDecl>(D) &&
710       !D->isConstexpr() &&
711       !SpecInfo)
712     AbbrevToUse = Writer.getDeclVarAbbrev();
713 
714   Code = serialization::DECL_VAR;
715 }
716 
717 void ASTDeclWriter::VisitImplicitParamDecl(ImplicitParamDecl *D) {
718   VisitVarDecl(D);
719   Code = serialization::DECL_IMPLICIT_PARAM;
720 }
721 
722 void ASTDeclWriter::VisitParmVarDecl(ParmVarDecl *D) {
723   VisitVarDecl(D);
724   Record.push_back(D->isObjCMethodParameter());
725   Record.push_back(D->getFunctionScopeDepth());
726   Record.push_back(D->getFunctionScopeIndex());
727   Record.push_back(D->getObjCDeclQualifier()); // FIXME: stable encoding
728   Record.push_back(D->isKNRPromoted());
729   Record.push_back(D->hasInheritedDefaultArg());
730   Record.push_back(D->hasUninstantiatedDefaultArg());
731   if (D->hasUninstantiatedDefaultArg())
732     Writer.AddStmt(D->getUninstantiatedDefaultArg());
733   Code = serialization::DECL_PARM_VAR;
734 
735   assert(!D->isARCPseudoStrong()); // can be true of ImplicitParamDecl
736 
737   // If the assumptions about the DECL_PARM_VAR abbrev are true, use it.  Here
738   // we dynamically check for the properties that we optimize for, but don't
739   // know are true of all PARM_VAR_DECLs.
740   if (!D->hasAttrs() &&
741       !D->hasExtInfo() &&
742       !D->isImplicit() &&
743       !D->isUsed(false) &&
744       !D->isInvalidDecl() &&
745       !D->isReferenced() &&
746       D->getAccess() == AS_none &&
747       !D->isModulePrivate() &&
748       D->getStorageClass() == 0 &&
749       D->getInitStyle() == VarDecl::CInit && // Can params have anything else?
750       D->getFunctionScopeDepth() == 0 &&
751       D->getObjCDeclQualifier() == 0 &&
752       !D->isKNRPromoted() &&
753       !D->hasInheritedDefaultArg() &&
754       D->getInit() == 0 &&
755       !D->hasUninstantiatedDefaultArg())  // No default expr.
756     AbbrevToUse = Writer.getDeclParmVarAbbrev();
757 
758   // Check things we know are true of *every* PARM_VAR_DECL, which is more than
759   // just us assuming it.
760   assert(!D->isThreadSpecified() && "PARM_VAR_DECL can't be __thread");
761   assert(D->getAccess() == AS_none && "PARM_VAR_DECL can't be public/private");
762   assert(!D->isExceptionVariable() && "PARM_VAR_DECL can't be exception var");
763   assert(D->getPreviousDecl() == 0 && "PARM_VAR_DECL can't be redecl");
764   assert(!D->isStaticDataMember() &&
765          "PARM_VAR_DECL can't be static data member");
766 }
767 
768 void ASTDeclWriter::VisitFileScopeAsmDecl(FileScopeAsmDecl *D) {
769   VisitDecl(D);
770   Writer.AddStmt(D->getAsmString());
771   Writer.AddSourceLocation(D->getRParenLoc(), Record);
772   Code = serialization::DECL_FILE_SCOPE_ASM;
773 }
774 
775 void ASTDeclWriter::VisitBlockDecl(BlockDecl *D) {
776   VisitDecl(D);
777   Writer.AddStmt(D->getBody());
778   Writer.AddTypeSourceInfo(D->getSignatureAsWritten(), Record);
779   Record.push_back(D->param_size());
780   for (FunctionDecl::param_iterator P = D->param_begin(), PEnd = D->param_end();
781        P != PEnd; ++P)
782     Writer.AddDeclRef(*P, Record);
783   Record.push_back(D->isVariadic());
784   Record.push_back(D->blockMissingReturnType());
785   Record.push_back(D->isConversionFromLambda());
786   Record.push_back(D->capturesCXXThis());
787   Record.push_back(D->getNumCaptures());
788   for (BlockDecl::capture_iterator
789          i = D->capture_begin(), e = D->capture_end(); i != e; ++i) {
790     const BlockDecl::Capture &capture = *i;
791     Writer.AddDeclRef(capture.getVariable(), Record);
792 
793     unsigned flags = 0;
794     if (capture.isByRef()) flags |= 1;
795     if (capture.isNested()) flags |= 2;
796     if (capture.hasCopyExpr()) flags |= 4;
797     Record.push_back(flags);
798 
799     if (capture.hasCopyExpr()) Writer.AddStmt(capture.getCopyExpr());
800   }
801 
802   Code = serialization::DECL_BLOCK;
803 }
804 
805 void ASTDeclWriter::VisitLinkageSpecDecl(LinkageSpecDecl *D) {
806   VisitDecl(D);
807   Record.push_back(D->getLanguage());
808   Writer.AddSourceLocation(D->getExternLoc(), Record);
809   Writer.AddSourceLocation(D->getRBraceLoc(), Record);
810   Code = serialization::DECL_LINKAGE_SPEC;
811 }
812 
813 void ASTDeclWriter::VisitLabelDecl(LabelDecl *D) {
814   VisitNamedDecl(D);
815   Writer.AddSourceLocation(D->getLocStart(), Record);
816   Code = serialization::DECL_LABEL;
817 }
818 
819 
820 void ASTDeclWriter::VisitNamespaceDecl(NamespaceDecl *D) {
821   VisitRedeclarable(D);
822   VisitNamedDecl(D);
823   Record.push_back(D->isInline());
824   Writer.AddSourceLocation(D->getLocStart(), Record);
825   Writer.AddSourceLocation(D->getRBraceLoc(), Record);
826 
827   if (D->isOriginalNamespace())
828     Writer.AddDeclRef(D->getAnonymousNamespace(), Record);
829   Code = serialization::DECL_NAMESPACE;
830 
831   if (Writer.hasChain() && !D->isOriginalNamespace() &&
832       D->getOriginalNamespace()->isFromASTFile()) {
833     NamespaceDecl *NS = D->getOriginalNamespace();
834     Writer.AddUpdatedDeclContext(NS);
835 
836     // Make sure all visible decls are written. They will be recorded later.
837     if (StoredDeclsMap *Map = NS->buildLookup()) {
838       for (StoredDeclsMap::iterator D = Map->begin(), DEnd = Map->end();
839            D != DEnd; ++D) {
840         DeclContext::lookup_result Result = D->second.getLookupResult();
841         while (Result.first != Result.second) {
842           Writer.GetDeclRef(*Result.first);
843           ++Result.first;
844         }
845       }
846     }
847   }
848 
849   if (Writer.hasChain() && D->isAnonymousNamespace() &&
850       D == D->getMostRecentDecl()) {
851     // This is a most recent reopening of the anonymous namespace. If its parent
852     // is in a previous PCH (or is the TU), mark that parent for update, because
853     // the original namespace always points to the latest re-opening of its
854     // anonymous namespace.
855     Decl *Parent = cast<Decl>(
856         D->getParent()->getRedeclContext()->getPrimaryContext());
857     if (Parent->isFromASTFile() || isa<TranslationUnitDecl>(Parent)) {
858       ASTWriter::UpdateRecord &Record = Writer.DeclUpdates[Parent];
859       Record.push_back(UPD_CXX_ADDED_ANONYMOUS_NAMESPACE);
860       Writer.AddDeclRef(D, Record);
861     }
862   }
863 }
864 
865 void ASTDeclWriter::VisitNamespaceAliasDecl(NamespaceAliasDecl *D) {
866   VisitNamedDecl(D);
867   Writer.AddSourceLocation(D->getNamespaceLoc(), Record);
868   Writer.AddSourceLocation(D->getTargetNameLoc(), Record);
869   Writer.AddNestedNameSpecifierLoc(D->getQualifierLoc(), Record);
870   Writer.AddDeclRef(D->getNamespace(), Record);
871   Code = serialization::DECL_NAMESPACE_ALIAS;
872 }
873 
874 void ASTDeclWriter::VisitUsingDecl(UsingDecl *D) {
875   VisitNamedDecl(D);
876   Writer.AddSourceLocation(D->getUsingLocation(), Record);
877   Writer.AddNestedNameSpecifierLoc(D->getQualifierLoc(), Record);
878   Writer.AddDeclarationNameLoc(D->DNLoc, D->getDeclName(), Record);
879   Writer.AddDeclRef(D->FirstUsingShadow.getPointer(), Record);
880   Record.push_back(D->isTypeName());
881   Writer.AddDeclRef(Context.getInstantiatedFromUsingDecl(D), Record);
882   Code = serialization::DECL_USING;
883 }
884 
885 void ASTDeclWriter::VisitUsingShadowDecl(UsingShadowDecl *D) {
886   VisitNamedDecl(D);
887   Writer.AddDeclRef(D->getTargetDecl(), Record);
888   Writer.AddDeclRef(D->UsingOrNextShadow, Record);
889   Writer.AddDeclRef(Context.getInstantiatedFromUsingShadowDecl(D), Record);
890   Code = serialization::DECL_USING_SHADOW;
891 }
892 
893 void ASTDeclWriter::VisitUsingDirectiveDecl(UsingDirectiveDecl *D) {
894   VisitNamedDecl(D);
895   Writer.AddSourceLocation(D->getUsingLoc(), Record);
896   Writer.AddSourceLocation(D->getNamespaceKeyLocation(), Record);
897   Writer.AddNestedNameSpecifierLoc(D->getQualifierLoc(), Record);
898   Writer.AddDeclRef(D->getNominatedNamespace(), Record);
899   Writer.AddDeclRef(dyn_cast<Decl>(D->getCommonAncestor()), Record);
900   Code = serialization::DECL_USING_DIRECTIVE;
901 }
902 
903 void ASTDeclWriter::VisitUnresolvedUsingValueDecl(UnresolvedUsingValueDecl *D) {
904   VisitValueDecl(D);
905   Writer.AddSourceLocation(D->getUsingLoc(), Record);
906   Writer.AddNestedNameSpecifierLoc(D->getQualifierLoc(), Record);
907   Writer.AddDeclarationNameLoc(D->DNLoc, D->getDeclName(), Record);
908   Code = serialization::DECL_UNRESOLVED_USING_VALUE;
909 }
910 
911 void ASTDeclWriter::VisitUnresolvedUsingTypenameDecl(
912                                                UnresolvedUsingTypenameDecl *D) {
913   VisitTypeDecl(D);
914   Writer.AddSourceLocation(D->getTypenameLoc(), Record);
915   Writer.AddNestedNameSpecifierLoc(D->getQualifierLoc(), Record);
916   Code = serialization::DECL_UNRESOLVED_USING_TYPENAME;
917 }
918 
919 void ASTDeclWriter::VisitCXXRecordDecl(CXXRecordDecl *D) {
920   VisitRecordDecl(D);
921   Record.push_back(D->isThisDeclarationADefinition());
922   if (D->isThisDeclarationADefinition())
923     Writer.AddCXXDefinitionData(D, Record);
924 
925   enum {
926     CXXRecNotTemplate = 0, CXXRecTemplate, CXXRecMemberSpecialization
927   };
928   if (ClassTemplateDecl *TemplD = D->getDescribedClassTemplate()) {
929     Record.push_back(CXXRecTemplate);
930     Writer.AddDeclRef(TemplD, Record);
931   } else if (MemberSpecializationInfo *MSInfo
932                = D->getMemberSpecializationInfo()) {
933     Record.push_back(CXXRecMemberSpecialization);
934     Writer.AddDeclRef(MSInfo->getInstantiatedFrom(), Record);
935     Record.push_back(MSInfo->getTemplateSpecializationKind());
936     Writer.AddSourceLocation(MSInfo->getPointOfInstantiation(), Record);
937   } else {
938     Record.push_back(CXXRecNotTemplate);
939   }
940 
941   // Store the key function to avoid deserializing every method so we can
942   // compute it.
943   if (D->IsCompleteDefinition)
944     Writer.AddDeclRef(Context.getKeyFunction(D), Record);
945 
946   Code = serialization::DECL_CXX_RECORD;
947 }
948 
949 void ASTDeclWriter::VisitCXXMethodDecl(CXXMethodDecl *D) {
950   VisitFunctionDecl(D);
951   Record.push_back(D->size_overridden_methods());
952   for (CXXMethodDecl::method_iterator
953          I = D->begin_overridden_methods(), E = D->end_overridden_methods();
954          I != E; ++I)
955     Writer.AddDeclRef(*I, Record);
956   Code = serialization::DECL_CXX_METHOD;
957 }
958 
959 void ASTDeclWriter::VisitCXXConstructorDecl(CXXConstructorDecl *D) {
960   VisitCXXMethodDecl(D);
961 
962   Record.push_back(D->IsExplicitSpecified);
963   Record.push_back(D->ImplicitlyDefined);
964   Writer.AddCXXCtorInitializers(D->CtorInitializers, D->NumCtorInitializers,
965                                 Record);
966 
967   Code = serialization::DECL_CXX_CONSTRUCTOR;
968 }
969 
970 void ASTDeclWriter::VisitCXXDestructorDecl(CXXDestructorDecl *D) {
971   VisitCXXMethodDecl(D);
972 
973   Record.push_back(D->ImplicitlyDefined);
974   Writer.AddDeclRef(D->OperatorDelete, Record);
975 
976   Code = serialization::DECL_CXX_DESTRUCTOR;
977 }
978 
979 void ASTDeclWriter::VisitCXXConversionDecl(CXXConversionDecl *D) {
980   VisitCXXMethodDecl(D);
981   Record.push_back(D->IsExplicitSpecified);
982   Code = serialization::DECL_CXX_CONVERSION;
983 }
984 
985 void ASTDeclWriter::VisitImportDecl(ImportDecl *D) {
986   VisitDecl(D);
987   ArrayRef<SourceLocation> IdentifierLocs = D->getIdentifierLocs();
988   Record.push_back(!IdentifierLocs.empty());
989   if (IdentifierLocs.empty()) {
990     Writer.AddSourceLocation(D->getLocEnd(), Record);
991     Record.push_back(1);
992   } else {
993     for (unsigned I = 0, N = IdentifierLocs.size(); I != N; ++I)
994       Writer.AddSourceLocation(IdentifierLocs[I], Record);
995     Record.push_back(IdentifierLocs.size());
996   }
997   // Note: the number of source locations must always be the last element in
998   // the record.
999   Code = serialization::DECL_IMPORT;
1000 }
1001 
1002 void ASTDeclWriter::VisitAccessSpecDecl(AccessSpecDecl *D) {
1003   VisitDecl(D);
1004   Writer.AddSourceLocation(D->getColonLoc(), Record);
1005   Code = serialization::DECL_ACCESS_SPEC;
1006 }
1007 
1008 void ASTDeclWriter::VisitFriendDecl(FriendDecl *D) {
1009   VisitDecl(D);
1010   Record.push_back(D->Friend.is<TypeSourceInfo*>());
1011   if (D->Friend.is<TypeSourceInfo*>())
1012     Writer.AddTypeSourceInfo(D->Friend.get<TypeSourceInfo*>(), Record);
1013   else
1014     Writer.AddDeclRef(D->Friend.get<NamedDecl*>(), Record);
1015   Writer.AddDeclRef(D->getNextFriend(), Record);
1016   Record.push_back(D->UnsupportedFriend);
1017   Writer.AddSourceLocation(D->FriendLoc, Record);
1018   Code = serialization::DECL_FRIEND;
1019 }
1020 
1021 void ASTDeclWriter::VisitFriendTemplateDecl(FriendTemplateDecl *D) {
1022   VisitDecl(D);
1023   Record.push_back(D->getNumTemplateParameters());
1024   for (unsigned i = 0, e = D->getNumTemplateParameters(); i != e; ++i)
1025     Writer.AddTemplateParameterList(D->getTemplateParameterList(i), Record);
1026   Record.push_back(D->getFriendDecl() != 0);
1027   if (D->getFriendDecl())
1028     Writer.AddDeclRef(D->getFriendDecl(), Record);
1029   else
1030     Writer.AddTypeSourceInfo(D->getFriendType(), Record);
1031   Writer.AddSourceLocation(D->getFriendLoc(), Record);
1032   Code = serialization::DECL_FRIEND_TEMPLATE;
1033 }
1034 
1035 void ASTDeclWriter::VisitTemplateDecl(TemplateDecl *D) {
1036   VisitNamedDecl(D);
1037 
1038   Writer.AddDeclRef(D->getTemplatedDecl(), Record);
1039   Writer.AddTemplateParameterList(D->getTemplateParameters(), Record);
1040 }
1041 
1042 void ASTDeclWriter::VisitRedeclarableTemplateDecl(RedeclarableTemplateDecl *D) {
1043   VisitRedeclarable(D);
1044 
1045   // Emit data to initialize CommonOrPrev before VisitTemplateDecl so that
1046   // getCommonPtr() can be used while this is still initializing.
1047   if (D->isFirstDeclaration()) {
1048     // This declaration owns the 'common' pointer, so serialize that data now.
1049     Writer.AddDeclRef(D->getInstantiatedFromMemberTemplate(), Record);
1050     if (D->getInstantiatedFromMemberTemplate())
1051       Record.push_back(D->isMemberSpecialization());
1052   }
1053 
1054   VisitTemplateDecl(D);
1055   Record.push_back(D->getIdentifierNamespace());
1056 }
1057 
1058 void ASTDeclWriter::VisitClassTemplateDecl(ClassTemplateDecl *D) {
1059   VisitRedeclarableTemplateDecl(D);
1060 
1061   if (D->isFirstDeclaration()) {
1062     typedef llvm::FoldingSetVector<ClassTemplateSpecializationDecl> CTSDSetTy;
1063     CTSDSetTy &CTSDSet = D->getSpecializations();
1064     Record.push_back(CTSDSet.size());
1065     for (CTSDSetTy::iterator I=CTSDSet.begin(), E = CTSDSet.end(); I!=E; ++I) {
1066       assert(I->isCanonicalDecl() && "Expected only canonical decls in set");
1067       Writer.AddDeclRef(&*I, Record);
1068     }
1069 
1070     typedef llvm::FoldingSetVector<ClassTemplatePartialSpecializationDecl>
1071       CTPSDSetTy;
1072     CTPSDSetTy &CTPSDSet = D->getPartialSpecializations();
1073     Record.push_back(CTPSDSet.size());
1074     for (CTPSDSetTy::iterator I=CTPSDSet.begin(), E=CTPSDSet.end(); I!=E; ++I) {
1075       assert(I->isCanonicalDecl() && "Expected only canonical decls in set");
1076       Writer.AddDeclRef(&*I, Record);
1077     }
1078 
1079     // InjectedClassNameType is computed, no need to write it.
1080   }
1081   Code = serialization::DECL_CLASS_TEMPLATE;
1082 }
1083 
1084 void ASTDeclWriter::VisitClassTemplateSpecializationDecl(
1085                                            ClassTemplateSpecializationDecl *D) {
1086   VisitCXXRecordDecl(D);
1087 
1088   llvm::PointerUnion<ClassTemplateDecl *,
1089                      ClassTemplatePartialSpecializationDecl *> InstFrom
1090     = D->getSpecializedTemplateOrPartial();
1091   if (Decl *InstFromD = InstFrom.dyn_cast<ClassTemplateDecl *>()) {
1092     Writer.AddDeclRef(InstFromD, Record);
1093   } else {
1094     Writer.AddDeclRef(InstFrom.get<ClassTemplatePartialSpecializationDecl *>(),
1095                       Record);
1096     Writer.AddTemplateArgumentList(&D->getTemplateInstantiationArgs(), Record);
1097   }
1098 
1099   // Explicit info.
1100   Writer.AddTypeSourceInfo(D->getTypeAsWritten(), Record);
1101   if (D->getTypeAsWritten()) {
1102     Writer.AddSourceLocation(D->getExternLoc(), Record);
1103     Writer.AddSourceLocation(D->getTemplateKeywordLoc(), Record);
1104   }
1105 
1106   Writer.AddTemplateArgumentList(&D->getTemplateArgs(), Record);
1107   Writer.AddSourceLocation(D->getPointOfInstantiation(), Record);
1108   Record.push_back(D->getSpecializationKind());
1109 
1110   if (D->isCanonicalDecl()) {
1111     // When reading, we'll add it to the folding set of the following template.
1112     Writer.AddDeclRef(D->getSpecializedTemplate()->getCanonicalDecl(), Record);
1113   }
1114 
1115   Code = serialization::DECL_CLASS_TEMPLATE_SPECIALIZATION;
1116 }
1117 
1118 void ASTDeclWriter::VisitClassTemplatePartialSpecializationDecl(
1119                                     ClassTemplatePartialSpecializationDecl *D) {
1120   VisitClassTemplateSpecializationDecl(D);
1121 
1122   Writer.AddTemplateParameterList(D->getTemplateParameters(), Record);
1123 
1124   Record.push_back(D->getNumTemplateArgsAsWritten());
1125   for (int i = 0, e = D->getNumTemplateArgsAsWritten(); i != e; ++i)
1126     Writer.AddTemplateArgumentLoc(D->getTemplateArgsAsWritten()[i], Record);
1127 
1128   Record.push_back(D->getSequenceNumber());
1129 
1130   // These are read/set from/to the first declaration.
1131   if (D->getPreviousDecl() == 0) {
1132     Writer.AddDeclRef(D->getInstantiatedFromMember(), Record);
1133     Record.push_back(D->isMemberSpecialization());
1134   }
1135 
1136   Code = serialization::DECL_CLASS_TEMPLATE_PARTIAL_SPECIALIZATION;
1137 }
1138 
1139 void ASTDeclWriter::VisitClassScopeFunctionSpecializationDecl(
1140                                     ClassScopeFunctionSpecializationDecl *D) {
1141   VisitDecl(D);
1142   Writer.AddDeclRef(D->getSpecialization(), Record);
1143   Code = serialization::DECL_CLASS_SCOPE_FUNCTION_SPECIALIZATION;
1144 }
1145 
1146 
1147 void ASTDeclWriter::VisitFunctionTemplateDecl(FunctionTemplateDecl *D) {
1148   VisitRedeclarableTemplateDecl(D);
1149 
1150   if (D->isFirstDeclaration()) {
1151     // This FunctionTemplateDecl owns the CommonPtr; write it.
1152 
1153     // Write the function specialization declarations.
1154     Record.push_back(D->getSpecializations().size());
1155     for (llvm::FoldingSetVector<FunctionTemplateSpecializationInfo>::iterator
1156            I = D->getSpecializations().begin(),
1157            E = D->getSpecializations().end()   ; I != E; ++I) {
1158       assert(I->Function->isCanonicalDecl() &&
1159              "Expected only canonical decls in set");
1160       Writer.AddDeclRef(I->Function, Record);
1161     }
1162   }
1163   Code = serialization::DECL_FUNCTION_TEMPLATE;
1164 }
1165 
1166 void ASTDeclWriter::VisitTemplateTypeParmDecl(TemplateTypeParmDecl *D) {
1167   VisitTypeDecl(D);
1168 
1169   Record.push_back(D->wasDeclaredWithTypename());
1170   Record.push_back(D->defaultArgumentWasInherited());
1171   Writer.AddTypeSourceInfo(D->getDefaultArgumentInfo(), Record);
1172 
1173   Code = serialization::DECL_TEMPLATE_TYPE_PARM;
1174 }
1175 
1176 void ASTDeclWriter::VisitNonTypeTemplateParmDecl(NonTypeTemplateParmDecl *D) {
1177   // For an expanded parameter pack, record the number of expansion types here
1178   // so that it's easier for deserialization to allocate the right amount of
1179   // memory.
1180   if (D->isExpandedParameterPack())
1181     Record.push_back(D->getNumExpansionTypes());
1182 
1183   VisitDeclaratorDecl(D);
1184   // TemplateParmPosition.
1185   Record.push_back(D->getDepth());
1186   Record.push_back(D->getPosition());
1187 
1188   if (D->isExpandedParameterPack()) {
1189     for (unsigned I = 0, N = D->getNumExpansionTypes(); I != N; ++I) {
1190       Writer.AddTypeRef(D->getExpansionType(I), Record);
1191       Writer.AddTypeSourceInfo(D->getExpansionTypeSourceInfo(I), Record);
1192     }
1193 
1194     Code = serialization::DECL_EXPANDED_NON_TYPE_TEMPLATE_PARM_PACK;
1195   } else {
1196     // Rest of NonTypeTemplateParmDecl.
1197     Record.push_back(D->isParameterPack());
1198     Record.push_back(D->getDefaultArgument() != 0);
1199     if (D->getDefaultArgument()) {
1200       Writer.AddStmt(D->getDefaultArgument());
1201       Record.push_back(D->defaultArgumentWasInherited());
1202     }
1203     Code = serialization::DECL_NON_TYPE_TEMPLATE_PARM;
1204   }
1205 }
1206 
1207 void ASTDeclWriter::VisitTemplateTemplateParmDecl(TemplateTemplateParmDecl *D) {
1208   // For an expanded parameter pack, record the number of expansion types here
1209   // so that it's easier for deserialization to allocate the right amount of
1210   // memory.
1211   if (D->isExpandedParameterPack())
1212     Record.push_back(D->getNumExpansionTemplateParameters());
1213 
1214   VisitTemplateDecl(D);
1215   // TemplateParmPosition.
1216   Record.push_back(D->getDepth());
1217   Record.push_back(D->getPosition());
1218 
1219   if (D->isExpandedParameterPack()) {
1220     for (unsigned I = 0, N = D->getNumExpansionTemplateParameters();
1221          I != N; ++I)
1222       Writer.AddTemplateParameterList(D->getExpansionTemplateParameters(I),
1223                                       Record);
1224     Code = serialization::DECL_EXPANDED_TEMPLATE_TEMPLATE_PARM_PACK;
1225   } else {
1226     // Rest of TemplateTemplateParmDecl.
1227     Writer.AddTemplateArgumentLoc(D->getDefaultArgument(), Record);
1228     Record.push_back(D->defaultArgumentWasInherited());
1229     Record.push_back(D->isParameterPack());
1230     Code = serialization::DECL_TEMPLATE_TEMPLATE_PARM;
1231   }
1232 }
1233 
1234 void ASTDeclWriter::VisitTypeAliasTemplateDecl(TypeAliasTemplateDecl *D) {
1235   VisitRedeclarableTemplateDecl(D);
1236   Code = serialization::DECL_TYPE_ALIAS_TEMPLATE;
1237 }
1238 
1239 void ASTDeclWriter::VisitStaticAssertDecl(StaticAssertDecl *D) {
1240   VisitDecl(D);
1241   Writer.AddStmt(D->getAssertExpr());
1242   Record.push_back(D->isFailed());
1243   Writer.AddStmt(D->getMessage());
1244   Writer.AddSourceLocation(D->getRParenLoc(), Record);
1245   Code = serialization::DECL_STATIC_ASSERT;
1246 }
1247 
1248 /// \brief Emit the DeclContext part of a declaration context decl.
1249 ///
1250 /// \param LexicalOffset the offset at which the DECL_CONTEXT_LEXICAL
1251 /// block for this declaration context is stored. May be 0 to indicate
1252 /// that there are no declarations stored within this context.
1253 ///
1254 /// \param VisibleOffset the offset at which the DECL_CONTEXT_VISIBLE
1255 /// block for this declaration context is stored. May be 0 to indicate
1256 /// that there are no declarations visible from this context. Note
1257 /// that this value will not be emitted for non-primary declaration
1258 /// contexts.
1259 void ASTDeclWriter::VisitDeclContext(DeclContext *DC, uint64_t LexicalOffset,
1260                                      uint64_t VisibleOffset) {
1261   Record.push_back(LexicalOffset);
1262   Record.push_back(VisibleOffset);
1263 }
1264 
1265 template <typename T>
1266 void ASTDeclWriter::VisitRedeclarable(Redeclarable<T> *D) {
1267   T *First = D->getFirstDeclaration();
1268   if (First->getMostRecentDecl() != First) {
1269     // There is more than one declaration of this entity, so we will need to
1270     // write a redeclaration chain.
1271     Writer.AddDeclRef(First, Record);
1272     Writer.Redeclarations.insert(First);
1273 
1274     // Make sure that we serialize both the previous and the most-recent
1275     // declarations, which (transitively) ensures that all declarations in the
1276     // chain get serialized.
1277     (void)Writer.GetDeclRef(D->getPreviousDecl());
1278     (void)Writer.GetDeclRef(First->getMostRecentDecl());
1279   } else {
1280     // We use the sentinel value 0 to indicate an only declaration.
1281     Record.push_back(0);
1282   }
1283 
1284 }
1285 
1286 //===----------------------------------------------------------------------===//
1287 // ASTWriter Implementation
1288 //===----------------------------------------------------------------------===//
1289 
1290 void ASTWriter::WriteDeclsBlockAbbrevs() {
1291   using namespace llvm;
1292 
1293   BitCodeAbbrev *Abv;
1294 
1295   // Abbreviation for DECL_FIELD
1296   Abv = new BitCodeAbbrev();
1297   Abv->Add(BitCodeAbbrevOp(serialization::DECL_FIELD));
1298   // Decl
1299   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclContext
1300   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LexicalDeclContext
1301   Abv->Add(BitCodeAbbrevOp(0));                       // isInvalidDecl
1302   Abv->Add(BitCodeAbbrevOp(0));                       // HasAttrs
1303   Abv->Add(BitCodeAbbrevOp(0));                       // isImplicit
1304   Abv->Add(BitCodeAbbrevOp(0));                       // isUsed
1305   Abv->Add(BitCodeAbbrevOp(0));                       // isReferenced
1306   Abv->Add(BitCodeAbbrevOp(0));                   // TopLevelDeclInObjCContainer
1307   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2));  // AccessSpecifier
1308   Abv->Add(BitCodeAbbrevOp(0));                       // ModulePrivate
1309   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // SubmoduleID
1310   // NamedDecl
1311   Abv->Add(BitCodeAbbrevOp(0));                       // NameKind = Identifier
1312   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Name
1313   // ValueDecl
1314   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
1315   // DeclaratorDecl
1316   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // InnerStartLoc
1317   Abv->Add(BitCodeAbbrevOp(0));                       // hasExtInfo
1318   // FieldDecl
1319   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isMutable
1320   Abv->Add(BitCodeAbbrevOp(0));                       //getBitWidth
1321   // Type Source Info
1322   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1323   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1324   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // TypeLoc
1325   DeclFieldAbbrev = Stream.EmitAbbrev(Abv);
1326 
1327   // Abbreviation for DECL_OBJC_IVAR
1328   Abv = new BitCodeAbbrev();
1329   Abv->Add(BitCodeAbbrevOp(serialization::DECL_OBJC_IVAR));
1330   // Decl
1331   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclContext
1332   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LexicalDeclContext
1333   Abv->Add(BitCodeAbbrevOp(0));                       // isInvalidDecl
1334   Abv->Add(BitCodeAbbrevOp(0));                       // HasAttrs
1335   Abv->Add(BitCodeAbbrevOp(0));                       // isImplicit
1336   Abv->Add(BitCodeAbbrevOp(0));                       // isUsed
1337   Abv->Add(BitCodeAbbrevOp(0));                       // isReferenced
1338   Abv->Add(BitCodeAbbrevOp(0));                   // TopLevelDeclInObjCContainer
1339   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2));  // AccessSpecifier
1340   Abv->Add(BitCodeAbbrevOp(0));                       // ModulePrivate
1341   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // SubmoduleID
1342   // NamedDecl
1343   Abv->Add(BitCodeAbbrevOp(0));                       // NameKind = Identifier
1344   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Name
1345   // ValueDecl
1346   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
1347   // DeclaratorDecl
1348   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // InnerStartLoc
1349   Abv->Add(BitCodeAbbrevOp(0));                       // hasExtInfo
1350   // FieldDecl
1351   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isMutable
1352   Abv->Add(BitCodeAbbrevOp(0));                       //getBitWidth
1353   // ObjC Ivar
1354   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // getAccessControl
1355   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // getSynthesize
1356   // Type Source Info
1357   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1358   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1359   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // TypeLoc
1360   DeclObjCIvarAbbrev = Stream.EmitAbbrev(Abv);
1361 
1362   // Abbreviation for DECL_ENUM
1363   Abv = new BitCodeAbbrev();
1364   Abv->Add(BitCodeAbbrevOp(serialization::DECL_ENUM));
1365   // Redeclarable
1366   Abv->Add(BitCodeAbbrevOp(0));                       // No redeclaration
1367   // Decl
1368   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclContext
1369   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LexicalDeclContext
1370   Abv->Add(BitCodeAbbrevOp(0));                       // isInvalidDecl
1371   Abv->Add(BitCodeAbbrevOp(0));                       // HasAttrs
1372   Abv->Add(BitCodeAbbrevOp(0));                       // isImplicit
1373   Abv->Add(BitCodeAbbrevOp(0));                       // isUsed
1374   Abv->Add(BitCodeAbbrevOp(0));                       // isReferenced
1375   Abv->Add(BitCodeAbbrevOp(0));                   // TopLevelDeclInObjCContainer
1376   Abv->Add(BitCodeAbbrevOp(AS_none));                 // C++ AccessSpecifier
1377   Abv->Add(BitCodeAbbrevOp(0));                       // ModulePrivate
1378   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // SubmoduleID
1379   // NamedDecl
1380   Abv->Add(BitCodeAbbrevOp(0));                       // NameKind = Identifier
1381   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Name
1382   // TypeDecl
1383   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Source Location
1384   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type Ref
1385   // TagDecl
1386   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // IdentifierNamespace
1387   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // getTagKind
1388   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isCompleteDefinition
1389   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // EmbeddedInDeclarator
1390   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsFreeStanding
1391   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // SourceLocation
1392   Abv->Add(BitCodeAbbrevOp(0));                         // hasExtInfo
1393   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // TypedefNameAnonDecl
1394   // EnumDecl
1395   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // AddTypeRef
1396   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // IntegerType
1397   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // getPromotionType
1398   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // getNumPositiveBits
1399   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // getNumNegativeBits
1400   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isScoped
1401   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isScopedUsingClassTag
1402   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isFixed
1403   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // InstantiatedMembEnum
1404   // DC
1405   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // LexicalOffset
1406   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // VisibleOffset
1407   DeclEnumAbbrev = Stream.EmitAbbrev(Abv);
1408 
1409   // Abbreviation for DECL_RECORD
1410   Abv = new BitCodeAbbrev();
1411   Abv->Add(BitCodeAbbrevOp(serialization::DECL_RECORD));
1412   // Redeclarable
1413   Abv->Add(BitCodeAbbrevOp(0));                       // No redeclaration
1414   // Decl
1415   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclContext
1416   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LexicalDeclContext
1417   Abv->Add(BitCodeAbbrevOp(0));                       // isInvalidDecl
1418   Abv->Add(BitCodeAbbrevOp(0));                       // HasAttrs
1419   Abv->Add(BitCodeAbbrevOp(0));                       // isImplicit
1420   Abv->Add(BitCodeAbbrevOp(0));                       // isUsed
1421   Abv->Add(BitCodeAbbrevOp(0));                       // isReferenced
1422   Abv->Add(BitCodeAbbrevOp(0));                   // TopLevelDeclInObjCContainer
1423   Abv->Add(BitCodeAbbrevOp(AS_none));                 // C++ AccessSpecifier
1424   Abv->Add(BitCodeAbbrevOp(0));                       // ModulePrivate
1425   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // SubmoduleID
1426   // NamedDecl
1427   Abv->Add(BitCodeAbbrevOp(0));                       // NameKind = Identifier
1428   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Name
1429   // TypeDecl
1430   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Source Location
1431   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type Ref
1432   // TagDecl
1433   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // IdentifierNamespace
1434   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // getTagKind
1435   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isCompleteDefinition
1436   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // EmbeddedInDeclarator
1437   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsFreeStanding
1438   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // SourceLocation
1439   Abv->Add(BitCodeAbbrevOp(0));                         // hasExtInfo
1440   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // TypedefNameAnonDecl
1441   // RecordDecl
1442   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // FlexibleArrayMember
1443   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // AnonymousStructUnion
1444   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // hasObjectMember
1445   // DC
1446   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // LexicalOffset
1447   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // VisibleOffset
1448   DeclRecordAbbrev = Stream.EmitAbbrev(Abv);
1449 
1450   // Abbreviation for DECL_PARM_VAR
1451   Abv = new BitCodeAbbrev();
1452   Abv->Add(BitCodeAbbrevOp(serialization::DECL_PARM_VAR));
1453   // Redeclarable
1454   Abv->Add(BitCodeAbbrevOp(0));                       // No redeclaration
1455   // Decl
1456   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclContext
1457   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LexicalDeclContext
1458   Abv->Add(BitCodeAbbrevOp(0));                       // isInvalidDecl
1459   Abv->Add(BitCodeAbbrevOp(0));                       // HasAttrs
1460   Abv->Add(BitCodeAbbrevOp(0));                       // isImplicit
1461   Abv->Add(BitCodeAbbrevOp(0));                       // isUsed
1462   Abv->Add(BitCodeAbbrevOp(0));                       // isReferenced
1463   Abv->Add(BitCodeAbbrevOp(0));                   // TopLevelDeclInObjCContainer
1464   Abv->Add(BitCodeAbbrevOp(AS_none));                 // C++ AccessSpecifier
1465   Abv->Add(BitCodeAbbrevOp(0));                       // ModulePrivate
1466   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // SubmoduleID
1467   // NamedDecl
1468   Abv->Add(BitCodeAbbrevOp(0));                       // NameKind = Identifier
1469   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Name
1470   // ValueDecl
1471   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
1472   // DeclaratorDecl
1473   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // InnerStartLoc
1474   Abv->Add(BitCodeAbbrevOp(0));                       // hasExtInfo
1475   // VarDecl
1476   Abv->Add(BitCodeAbbrevOp(0));                       // StorageClass
1477   Abv->Add(BitCodeAbbrevOp(0));                       // StorageClassAsWritten
1478   Abv->Add(BitCodeAbbrevOp(0));                       // isThreadSpecified
1479   Abv->Add(BitCodeAbbrevOp(0));                       // hasCXXDirectInitializer
1480   Abv->Add(BitCodeAbbrevOp(0));                       // isExceptionVariable
1481   Abv->Add(BitCodeAbbrevOp(0));                       // isNRVOVariable
1482   Abv->Add(BitCodeAbbrevOp(0));                       // isCXXForRangeDecl
1483   Abv->Add(BitCodeAbbrevOp(0));                       // isARCPseudoStrong
1484   Abv->Add(BitCodeAbbrevOp(0));                       // isConstexpr
1485   Abv->Add(BitCodeAbbrevOp(0));                       // HasInit
1486   Abv->Add(BitCodeAbbrevOp(0));                   // HasMemberSpecializationInfo
1487   // ParmVarDecl
1488   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsObjCMethodParameter
1489   Abv->Add(BitCodeAbbrevOp(0));                       // ScopeDepth
1490   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // ScopeIndex
1491   Abv->Add(BitCodeAbbrevOp(0));                       // ObjCDeclQualifier
1492   Abv->Add(BitCodeAbbrevOp(0));                       // KNRPromoted
1493   Abv->Add(BitCodeAbbrevOp(0));                       // HasInheritedDefaultArg
1494   Abv->Add(BitCodeAbbrevOp(0));                   // HasUninstantiatedDefaultArg
1495   // Type Source Info
1496   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1497   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1498   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // TypeLoc
1499   DeclParmVarAbbrev = Stream.EmitAbbrev(Abv);
1500 
1501   // Abbreviation for DECL_TYPEDEF
1502   Abv = new BitCodeAbbrev();
1503   Abv->Add(BitCodeAbbrevOp(serialization::DECL_TYPEDEF));
1504   // Redeclarable
1505   Abv->Add(BitCodeAbbrevOp(0));                       // No redeclaration
1506   // Decl
1507   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclContext
1508   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LexicalDeclContext
1509   Abv->Add(BitCodeAbbrevOp(0));                       // isInvalidDecl
1510   Abv->Add(BitCodeAbbrevOp(0));                       // HasAttrs
1511   Abv->Add(BitCodeAbbrevOp(0));                       // isImplicit
1512   Abv->Add(BitCodeAbbrevOp(0));                       // isUsed
1513   Abv->Add(BitCodeAbbrevOp(0));                       // isReferenced
1514   Abv->Add(BitCodeAbbrevOp(0));                   // TopLevelDeclInObjCContainer
1515   Abv->Add(BitCodeAbbrevOp(AS_none));                 // C++ AccessSpecifier
1516   Abv->Add(BitCodeAbbrevOp(0));                       // ModulePrivate
1517   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // SubmoduleID
1518   // NamedDecl
1519   Abv->Add(BitCodeAbbrevOp(0));                       // NameKind = Identifier
1520   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Name
1521   // TypeDecl
1522   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Source Location
1523   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type Ref
1524   // TypedefDecl
1525   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1526   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // TypeLoc
1527   DeclTypedefAbbrev = Stream.EmitAbbrev(Abv);
1528 
1529   // Abbreviation for DECL_VAR
1530   Abv = new BitCodeAbbrev();
1531   Abv->Add(BitCodeAbbrevOp(serialization::DECL_VAR));
1532   // Redeclarable
1533   Abv->Add(BitCodeAbbrevOp(0));                       // No redeclaration
1534   // Decl
1535   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclContext
1536   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LexicalDeclContext
1537   Abv->Add(BitCodeAbbrevOp(0));                       // isInvalidDecl
1538   Abv->Add(BitCodeAbbrevOp(0));                       // HasAttrs
1539   Abv->Add(BitCodeAbbrevOp(0));                       // isImplicit
1540   Abv->Add(BitCodeAbbrevOp(0));                       // isUsed
1541   Abv->Add(BitCodeAbbrevOp(0));                       // isReferenced
1542   Abv->Add(BitCodeAbbrevOp(0));                   // TopLevelDeclInObjCContainer
1543   Abv->Add(BitCodeAbbrevOp(AS_none));                 // C++ AccessSpecifier
1544   Abv->Add(BitCodeAbbrevOp(0));                       // ModulePrivate
1545   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // SubmoduleID
1546   // NamedDecl
1547   Abv->Add(BitCodeAbbrevOp(0));                       // NameKind = Identifier
1548   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Name
1549   // ValueDecl
1550   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
1551   // DeclaratorDecl
1552   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // InnerStartLoc
1553   Abv->Add(BitCodeAbbrevOp(0));                       // hasExtInfo
1554   // VarDecl
1555   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // StorageClass
1556   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // StorageClassAsWritten
1557   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isThreadSpecified
1558   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // CXXDirectInitializer
1559   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isExceptionVariable
1560   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isNRVOVariable
1561   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isCXXForRangeDecl
1562   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isARCPseudoStrong
1563   Abv->Add(BitCodeAbbrevOp(0));                         // isConstexpr
1564   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // HasInit
1565   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // HasMemberSpecInfo
1566   // Type Source Info
1567   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1568   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1569   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // TypeLoc
1570   DeclVarAbbrev = Stream.EmitAbbrev(Abv);
1571 
1572   // Abbreviation for EXPR_DECL_REF
1573   Abv = new BitCodeAbbrev();
1574   Abv->Add(BitCodeAbbrevOp(serialization::EXPR_DECL_REF));
1575   //Stmt
1576   //Expr
1577   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
1578   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //TypeDependent
1579   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //ValueDependent
1580   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //InstantiationDependent
1581   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //UnexpandedParamPack
1582   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetValueKind
1583   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetObjectKind
1584   //DeclRefExpr
1585   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //HasQualifier
1586   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //GetDeclFound
1587   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //ExplicitTemplateArgs
1588   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //HadMultipleCandidates
1589   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //RefersToEnclosingLocal
1590   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclRef
1591   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Location
1592   DeclRefExprAbbrev = Stream.EmitAbbrev(Abv);
1593 
1594   // Abbreviation for EXPR_INTEGER_LITERAL
1595   Abv = new BitCodeAbbrev();
1596   Abv->Add(BitCodeAbbrevOp(serialization::EXPR_INTEGER_LITERAL));
1597   //Stmt
1598   //Expr
1599   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
1600   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //TypeDependent
1601   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //ValueDependent
1602   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //InstantiationDependent
1603   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //UnexpandedParamPack
1604   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetValueKind
1605   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetObjectKind
1606   //Integer Literal
1607   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Location
1608   Abv->Add(BitCodeAbbrevOp(32));                      // Bit Width
1609   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Value
1610   IntegerLiteralAbbrev = Stream.EmitAbbrev(Abv);
1611 
1612   // Abbreviation for EXPR_CHARACTER_LITERAL
1613   Abv = new BitCodeAbbrev();
1614   Abv->Add(BitCodeAbbrevOp(serialization::EXPR_CHARACTER_LITERAL));
1615   //Stmt
1616   //Expr
1617   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
1618   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //TypeDependent
1619   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //ValueDependent
1620   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //InstantiationDependent
1621   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //UnexpandedParamPack
1622   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetValueKind
1623   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetObjectKind
1624   //Character Literal
1625   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // getValue
1626   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Location
1627   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2)); // getKind
1628   CharacterLiteralAbbrev = Stream.EmitAbbrev(Abv);
1629 
1630   Abv = new BitCodeAbbrev();
1631   Abv->Add(BitCodeAbbrevOp(serialization::DECL_CONTEXT_LEXICAL));
1632   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
1633   DeclContextLexicalAbbrev = Stream.EmitAbbrev(Abv);
1634 
1635   Abv = new BitCodeAbbrev();
1636   Abv->Add(BitCodeAbbrevOp(serialization::DECL_CONTEXT_VISIBLE));
1637   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
1638   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
1639   DeclContextVisibleLookupAbbrev = Stream.EmitAbbrev(Abv);
1640 }
1641 
1642 /// isRequiredDecl - Check if this is a "required" Decl, which must be seen by
1643 /// consumers of the AST.
1644 ///
1645 /// Such decls will always be deserialized from the AST file, so we would like
1646 /// this to be as restrictive as possible. Currently the predicate is driven by
1647 /// code generation requirements, if other clients have a different notion of
1648 /// what is "required" then we may have to consider an alternate scheme where
1649 /// clients can iterate over the top-level decls and get information on them,
1650 /// without necessary deserializing them. We could explicitly require such
1651 /// clients to use a separate API call to "realize" the decl. This should be
1652 /// relatively painless since they would presumably only do it for top-level
1653 /// decls.
1654 static bool isRequiredDecl(const Decl *D, ASTContext &Context) {
1655   // An ObjCMethodDecl is never considered as "required" because its
1656   // implementation container always is.
1657 
1658   // File scoped assembly or obj-c implementation must be seen.
1659   if (isa<FileScopeAsmDecl>(D) || isa<ObjCImplDecl>(D))
1660     return true;
1661 
1662   return Context.DeclMustBeEmitted(D);
1663 }
1664 
1665 void ASTWriter::WriteDecl(ASTContext &Context, Decl *D) {
1666   // Switch case IDs are per Decl.
1667   ClearSwitchCaseIDs();
1668 
1669   RecordData Record;
1670   ASTDeclWriter W(*this, Context, Record);
1671 
1672   // Determine the ID for this declaration.
1673   serialization::DeclID ID;
1674   if (D->isFromASTFile())
1675     ID = getDeclID(D);
1676   else {
1677     serialization::DeclID &IDR = DeclIDs[D];
1678     if (IDR == 0)
1679       IDR = NextDeclID++;
1680 
1681     ID= IDR;
1682   }
1683 
1684   bool isReplacingADecl = ID < FirstDeclID;
1685 
1686   // If this declaration is also a DeclContext, write blocks for the
1687   // declarations that lexically stored inside its context and those
1688   // declarations that are visible from its context. These blocks
1689   // are written before the declaration itself so that we can put
1690   // their offsets into the record for the declaration.
1691   uint64_t LexicalOffset = 0;
1692   uint64_t VisibleOffset = 0;
1693   DeclContext *DC = dyn_cast<DeclContext>(D);
1694   if (DC) {
1695     if (isReplacingADecl) {
1696       // It is replacing a decl from a chained PCH; make sure that the
1697       // DeclContext is fully loaded.
1698       if (DC->hasExternalLexicalStorage())
1699         DC->LoadLexicalDeclsFromExternalStorage();
1700       if (DC->hasExternalVisibleStorage())
1701         Chain->completeVisibleDeclsMap(DC);
1702     }
1703     LexicalOffset = WriteDeclContextLexicalBlock(Context, DC);
1704     VisibleOffset = WriteDeclContextVisibleBlock(Context, DC);
1705   }
1706 
1707   if (isReplacingADecl) {
1708     // We're replacing a decl in a previous file.
1709     ReplacedDecls.push_back(ReplacedDeclInfo(ID, Stream.GetCurrentBitNo(),
1710                                              D->getLocation()));
1711   } else {
1712     unsigned Index = ID - FirstDeclID;
1713 
1714     // Record the offset for this declaration
1715     SourceLocation Loc = D->getLocation();
1716     if (DeclOffsets.size() == Index)
1717       DeclOffsets.push_back(DeclOffset(Loc, Stream.GetCurrentBitNo()));
1718     else if (DeclOffsets.size() < Index) {
1719       DeclOffsets.resize(Index+1);
1720       DeclOffsets[Index].setLocation(Loc);
1721       DeclOffsets[Index].BitOffset = Stream.GetCurrentBitNo();
1722     }
1723 
1724     SourceManager &SM = Context.getSourceManager();
1725     if (Loc.isValid() && SM.isLocalSourceLocation(Loc))
1726       associateDeclWithFile(D, ID);
1727   }
1728 
1729   // Build and emit a record for this declaration
1730   Record.clear();
1731   W.Code = (serialization::DeclCode)0;
1732   W.AbbrevToUse = 0;
1733   W.Visit(D);
1734   if (DC) W.VisitDeclContext(DC, LexicalOffset, VisibleOffset);
1735 
1736   if (!W.Code)
1737     llvm::report_fatal_error(StringRef("unexpected declaration kind '") +
1738                             D->getDeclKindName() + "'");
1739   Stream.EmitRecord(W.Code, Record, W.AbbrevToUse);
1740 
1741   // Flush any expressions that were written as part of this declaration.
1742   FlushStmts();
1743 
1744   // Flush C++ base specifiers, if there are any.
1745   FlushCXXBaseSpecifiers();
1746 
1747   // Note "external" declarations so that we can add them to a record in the
1748   // AST file later.
1749   //
1750   // FIXME: This should be renamed, the predicate is much more complicated.
1751   if (isRequiredDecl(D, Context))
1752     ExternalDefinitions.push_back(ID);
1753 }
1754