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