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