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   if (D->InitializerOrBitWidth.getInt() != ICIS_NoInit ||
630       D->InitializerOrBitWidth.getPointer()) {
631     Record.push_back(D->InitializerOrBitWidth.getInt() + 1);
632     Writer.AddStmt(D->InitializerOrBitWidth.getPointer());
633   } else {
634     Record.push_back(0);
635   }
636   if (!D->getDeclName())
637     Writer.AddDeclRef(Context.getInstantiatedFromUnnamedFieldDecl(D), Record);
638 
639   if (!D->hasAttrs() &&
640       !D->isImplicit() &&
641       !D->isUsed(false) &&
642       !D->isInvalidDecl() &&
643       !D->isReferenced() &&
644       !D->isTopLevelDeclInObjCContainer() &&
645       !D->isModulePrivate() &&
646       !D->getBitWidth() &&
647       !D->hasInClassInitializer() &&
648       !D->hasExtInfo() &&
649       !ObjCIvarDecl::classofKind(D->getKind()) &&
650       !ObjCAtDefsFieldDecl::classofKind(D->getKind()) &&
651       D->getDeclName())
652     AbbrevToUse = Writer.getDeclFieldAbbrev();
653 
654   Code = serialization::DECL_FIELD;
655 }
656 
657 void ASTDeclWriter::VisitIndirectFieldDecl(IndirectFieldDecl *D) {
658   VisitValueDecl(D);
659   Record.push_back(D->getChainingSize());
660 
661   for (IndirectFieldDecl::chain_iterator
662        P = D->chain_begin(),
663        PEnd = D->chain_end(); P != PEnd; ++P)
664     Writer.AddDeclRef(*P, Record);
665   Code = serialization::DECL_INDIRECTFIELD;
666 }
667 
668 void ASTDeclWriter::VisitVarDecl(VarDecl *D) {
669   VisitRedeclarable(D);
670   VisitDeclaratorDecl(D);
671   Record.push_back(D->getStorageClass()); // FIXME: stable encoding
672   Record.push_back(D->getStorageClassAsWritten());
673   Record.push_back(D->isThreadSpecified());
674   Record.push_back(D->getInitStyle());
675   Record.push_back(D->isExceptionVariable());
676   Record.push_back(D->isNRVOVariable());
677   Record.push_back(D->isCXXForRangeDecl());
678   Record.push_back(D->isARCPseudoStrong());
679   if (D->getInit()) {
680     Record.push_back(!D->isInitKnownICE() ? 1 : (D->isInitICE() ? 3 : 2));
681     Writer.AddStmt(D->getInit());
682   } else {
683     Record.push_back(0);
684   }
685 
686   MemberSpecializationInfo *SpecInfo
687     = D->isStaticDataMember() ? D->getMemberSpecializationInfo() : 0;
688   Record.push_back(SpecInfo != 0);
689   if (SpecInfo) {
690     Writer.AddDeclRef(SpecInfo->getInstantiatedFrom(), Record);
691     Record.push_back(SpecInfo->getTemplateSpecializationKind());
692     Writer.AddSourceLocation(SpecInfo->getPointOfInstantiation(), Record);
693   }
694 
695   if (!D->hasAttrs() &&
696       !D->isImplicit() &&
697       !D->isUsed(false) &&
698       !D->isInvalidDecl() &&
699       !D->isReferenced() &&
700       !D->isTopLevelDeclInObjCContainer() &&
701       D->getAccess() == AS_none &&
702       !D->isModulePrivate() &&
703       D->getDeclName().getNameKind() == DeclarationName::Identifier &&
704       !D->hasExtInfo() &&
705       D->getFirstDeclaration() == D->getMostRecentDecl() &&
706       D->getInitStyle() == VarDecl::CInit &&
707       D->getInit() == 0 &&
708       !isa<ParmVarDecl>(D) &&
709       !SpecInfo)
710     AbbrevToUse = Writer.getDeclVarAbbrev();
711 
712   Code = serialization::DECL_VAR;
713 }
714 
715 void ASTDeclWriter::VisitImplicitParamDecl(ImplicitParamDecl *D) {
716   VisitVarDecl(D);
717   Code = serialization::DECL_IMPLICIT_PARAM;
718 }
719 
720 void ASTDeclWriter::VisitParmVarDecl(ParmVarDecl *D) {
721   VisitVarDecl(D);
722   Record.push_back(D->isObjCMethodParameter());
723   Record.push_back(D->getFunctionScopeDepth());
724   Record.push_back(D->getFunctionScopeIndex());
725   Record.push_back(D->getObjCDeclQualifier()); // FIXME: stable encoding
726   Record.push_back(D->isKNRPromoted());
727   Record.push_back(D->hasInheritedDefaultArg());
728   Record.push_back(D->hasUninstantiatedDefaultArg());
729   if (D->hasUninstantiatedDefaultArg())
730     Writer.AddStmt(D->getUninstantiatedDefaultArg());
731   Code = serialization::DECL_PARM_VAR;
732 
733   assert(!D->isARCPseudoStrong()); // can be true of ImplicitParamDecl
734 
735   // If the assumptions about the DECL_PARM_VAR abbrev are true, use it.  Here
736   // we dynamically check for the properties that we optimize for, but don't
737   // know are true of all PARM_VAR_DECLs.
738   if (!D->hasAttrs() &&
739       !D->hasExtInfo() &&
740       !D->isImplicit() &&
741       !D->isUsed(false) &&
742       !D->isInvalidDecl() &&
743       !D->isReferenced() &&
744       D->getAccess() == AS_none &&
745       !D->isModulePrivate() &&
746       D->getStorageClass() == 0 &&
747       D->getInitStyle() == VarDecl::CInit && // Can params have anything else?
748       D->getFunctionScopeDepth() == 0 &&
749       D->getObjCDeclQualifier() == 0 &&
750       !D->isKNRPromoted() &&
751       !D->hasInheritedDefaultArg() &&
752       D->getInit() == 0 &&
753       !D->hasUninstantiatedDefaultArg())  // No default expr.
754     AbbrevToUse = Writer.getDeclParmVarAbbrev();
755 
756   // Check things we know are true of *every* PARM_VAR_DECL, which is more than
757   // just us assuming it.
758   assert(!D->isThreadSpecified() && "PARM_VAR_DECL can't be __thread");
759   assert(D->getAccess() == AS_none && "PARM_VAR_DECL can't be public/private");
760   assert(!D->isExceptionVariable() && "PARM_VAR_DECL can't be exception var");
761   assert(D->getPreviousDecl() == 0 && "PARM_VAR_DECL can't be redecl");
762   assert(!D->isStaticDataMember() &&
763          "PARM_VAR_DECL can't be static data member");
764 }
765 
766 void ASTDeclWriter::VisitFileScopeAsmDecl(FileScopeAsmDecl *D) {
767   VisitDecl(D);
768   Writer.AddStmt(D->getAsmString());
769   Writer.AddSourceLocation(D->getRParenLoc(), Record);
770   Code = serialization::DECL_FILE_SCOPE_ASM;
771 }
772 
773 void ASTDeclWriter::VisitBlockDecl(BlockDecl *D) {
774   VisitDecl(D);
775   Writer.AddStmt(D->getBody());
776   Writer.AddTypeSourceInfo(D->getSignatureAsWritten(), Record);
777   Record.push_back(D->param_size());
778   for (FunctionDecl::param_iterator P = D->param_begin(), PEnd = D->param_end();
779        P != PEnd; ++P)
780     Writer.AddDeclRef(*P, Record);
781   Record.push_back(D->isVariadic());
782   Record.push_back(D->blockMissingReturnType());
783   Record.push_back(D->isConversionFromLambda());
784   Record.push_back(D->capturesCXXThis());
785   Record.push_back(D->getNumCaptures());
786   for (BlockDecl::capture_iterator
787          i = D->capture_begin(), e = D->capture_end(); i != e; ++i) {
788     const BlockDecl::Capture &capture = *i;
789     Writer.AddDeclRef(capture.getVariable(), Record);
790 
791     unsigned flags = 0;
792     if (capture.isByRef()) flags |= 1;
793     if (capture.isNested()) flags |= 2;
794     if (capture.hasCopyExpr()) flags |= 4;
795     Record.push_back(flags);
796 
797     if (capture.hasCopyExpr()) Writer.AddStmt(capture.getCopyExpr());
798   }
799 
800   Code = serialization::DECL_BLOCK;
801 }
802 
803 void ASTDeclWriter::VisitLinkageSpecDecl(LinkageSpecDecl *D) {
804   VisitDecl(D);
805   Record.push_back(D->getLanguage());
806   Writer.AddSourceLocation(D->getExternLoc(), Record);
807   Writer.AddSourceLocation(D->getRBraceLoc(), Record);
808   Code = serialization::DECL_LINKAGE_SPEC;
809 }
810 
811 void ASTDeclWriter::VisitLabelDecl(LabelDecl *D) {
812   VisitNamedDecl(D);
813   Writer.AddSourceLocation(D->getLocStart(), Record);
814   Code = serialization::DECL_LABEL;
815 }
816 
817 
818 void ASTDeclWriter::VisitNamespaceDecl(NamespaceDecl *D) {
819   VisitRedeclarable(D);
820   VisitNamedDecl(D);
821   Record.push_back(D->isInline());
822   Writer.AddSourceLocation(D->getLocStart(), Record);
823   Writer.AddSourceLocation(D->getRBraceLoc(), Record);
824 
825   if (D->isOriginalNamespace())
826     Writer.AddDeclRef(D->getAnonymousNamespace(), Record);
827   Code = serialization::DECL_NAMESPACE;
828 
829   if (Writer.hasChain() && !D->isOriginalNamespace() &&
830       D->getOriginalNamespace()->isFromASTFile()) {
831     NamespaceDecl *NS = D->getOriginalNamespace();
832     Writer.AddUpdatedDeclContext(NS);
833 
834     // Make sure all visible decls are written. They will be recorded later.
835     if (StoredDeclsMap *Map = NS->buildLookup()) {
836       for (StoredDeclsMap::iterator D = Map->begin(), DEnd = Map->end();
837            D != DEnd; ++D) {
838         DeclContext::lookup_result Result = D->second.getLookupResult();
839         while (Result.first != Result.second) {
840           Writer.GetDeclRef(*Result.first);
841           ++Result.first;
842         }
843       }
844     }
845   }
846 
847   if (Writer.hasChain() && D->isAnonymousNamespace() &&
848       D == D->getMostRecentDecl()) {
849     // This is a most recent reopening of the anonymous namespace. If its parent
850     // is in a previous PCH (or is the TU), mark that parent for update, because
851     // the original namespace always points to the latest re-opening of its
852     // anonymous namespace.
853     Decl *Parent = cast<Decl>(
854         D->getParent()->getRedeclContext()->getPrimaryContext());
855     if (Parent->isFromASTFile() || isa<TranslationUnitDecl>(Parent)) {
856       ASTWriter::UpdateRecord &Record = Writer.DeclUpdates[Parent];
857       Record.push_back(UPD_CXX_ADDED_ANONYMOUS_NAMESPACE);
858       Writer.AddDeclRef(D, Record);
859     }
860   }
861 }
862 
863 void ASTDeclWriter::VisitNamespaceAliasDecl(NamespaceAliasDecl *D) {
864   VisitNamedDecl(D);
865   Writer.AddSourceLocation(D->getNamespaceLoc(), Record);
866   Writer.AddSourceLocation(D->getTargetNameLoc(), Record);
867   Writer.AddNestedNameSpecifierLoc(D->getQualifierLoc(), Record);
868   Writer.AddDeclRef(D->getNamespace(), Record);
869   Code = serialization::DECL_NAMESPACE_ALIAS;
870 }
871 
872 void ASTDeclWriter::VisitUsingDecl(UsingDecl *D) {
873   VisitNamedDecl(D);
874   Writer.AddSourceLocation(D->getUsingLocation(), Record);
875   Writer.AddNestedNameSpecifierLoc(D->getQualifierLoc(), Record);
876   Writer.AddDeclarationNameLoc(D->DNLoc, D->getDeclName(), Record);
877   Writer.AddDeclRef(D->FirstUsingShadow.getPointer(), Record);
878   Record.push_back(D->isTypeName());
879   Writer.AddDeclRef(Context.getInstantiatedFromUsingDecl(D), Record);
880   Code = serialization::DECL_USING;
881 }
882 
883 void ASTDeclWriter::VisitUsingShadowDecl(UsingShadowDecl *D) {
884   VisitNamedDecl(D);
885   Writer.AddDeclRef(D->getTargetDecl(), Record);
886   Writer.AddDeclRef(D->UsingOrNextShadow, Record);
887   Writer.AddDeclRef(Context.getInstantiatedFromUsingShadowDecl(D), Record);
888   Code = serialization::DECL_USING_SHADOW;
889 }
890 
891 void ASTDeclWriter::VisitUsingDirectiveDecl(UsingDirectiveDecl *D) {
892   VisitNamedDecl(D);
893   Writer.AddSourceLocation(D->getUsingLoc(), Record);
894   Writer.AddSourceLocation(D->getNamespaceKeyLocation(), Record);
895   Writer.AddNestedNameSpecifierLoc(D->getQualifierLoc(), Record);
896   Writer.AddDeclRef(D->getNominatedNamespace(), Record);
897   Writer.AddDeclRef(dyn_cast<Decl>(D->getCommonAncestor()), Record);
898   Code = serialization::DECL_USING_DIRECTIVE;
899 }
900 
901 void ASTDeclWriter::VisitUnresolvedUsingValueDecl(UnresolvedUsingValueDecl *D) {
902   VisitValueDecl(D);
903   Writer.AddSourceLocation(D->getUsingLoc(), Record);
904   Writer.AddNestedNameSpecifierLoc(D->getQualifierLoc(), Record);
905   Writer.AddDeclarationNameLoc(D->DNLoc, D->getDeclName(), Record);
906   Code = serialization::DECL_UNRESOLVED_USING_VALUE;
907 }
908 
909 void ASTDeclWriter::VisitUnresolvedUsingTypenameDecl(
910                                                UnresolvedUsingTypenameDecl *D) {
911   VisitTypeDecl(D);
912   Writer.AddSourceLocation(D->getTypenameLoc(), Record);
913   Writer.AddNestedNameSpecifierLoc(D->getQualifierLoc(), Record);
914   Code = serialization::DECL_UNRESOLVED_USING_TYPENAME;
915 }
916 
917 void ASTDeclWriter::VisitCXXRecordDecl(CXXRecordDecl *D) {
918   VisitRecordDecl(D);
919   Record.push_back(D->isThisDeclarationADefinition());
920   if (D->isThisDeclarationADefinition())
921     Writer.AddCXXDefinitionData(D, Record);
922 
923   enum {
924     CXXRecNotTemplate = 0, CXXRecTemplate, CXXRecMemberSpecialization
925   };
926   if (ClassTemplateDecl *TemplD = D->getDescribedClassTemplate()) {
927     Record.push_back(CXXRecTemplate);
928     Writer.AddDeclRef(TemplD, Record);
929   } else if (MemberSpecializationInfo *MSInfo
930                = D->getMemberSpecializationInfo()) {
931     Record.push_back(CXXRecMemberSpecialization);
932     Writer.AddDeclRef(MSInfo->getInstantiatedFrom(), Record);
933     Record.push_back(MSInfo->getTemplateSpecializationKind());
934     Writer.AddSourceLocation(MSInfo->getPointOfInstantiation(), Record);
935   } else {
936     Record.push_back(CXXRecNotTemplate);
937   }
938 
939   // Store the key function to avoid deserializing every method so we can
940   // compute it.
941   if (D->IsCompleteDefinition)
942     Writer.AddDeclRef(Context.getKeyFunction(D), Record);
943 
944   Code = serialization::DECL_CXX_RECORD;
945 }
946 
947 void ASTDeclWriter::VisitCXXMethodDecl(CXXMethodDecl *D) {
948   VisitFunctionDecl(D);
949   Record.push_back(D->size_overridden_methods());
950   for (CXXMethodDecl::method_iterator
951          I = D->begin_overridden_methods(), E = D->end_overridden_methods();
952          I != E; ++I)
953     Writer.AddDeclRef(*I, Record);
954   Code = serialization::DECL_CXX_METHOD;
955 }
956 
957 void ASTDeclWriter::VisitCXXConstructorDecl(CXXConstructorDecl *D) {
958   VisitCXXMethodDecl(D);
959 
960   Record.push_back(D->IsExplicitSpecified);
961   Record.push_back(D->ImplicitlyDefined);
962   Writer.AddCXXCtorInitializers(D->CtorInitializers, D->NumCtorInitializers,
963                                 Record);
964 
965   Code = serialization::DECL_CXX_CONSTRUCTOR;
966 }
967 
968 void ASTDeclWriter::VisitCXXDestructorDecl(CXXDestructorDecl *D) {
969   VisitCXXMethodDecl(D);
970 
971   Record.push_back(D->ImplicitlyDefined);
972   Writer.AddDeclRef(D->OperatorDelete, Record);
973 
974   Code = serialization::DECL_CXX_DESTRUCTOR;
975 }
976 
977 void ASTDeclWriter::VisitCXXConversionDecl(CXXConversionDecl *D) {
978   VisitCXXMethodDecl(D);
979   Record.push_back(D->IsExplicitSpecified);
980   Code = serialization::DECL_CXX_CONVERSION;
981 }
982 
983 void ASTDeclWriter::VisitImportDecl(ImportDecl *D) {
984   VisitDecl(D);
985   ArrayRef<SourceLocation> IdentifierLocs = D->getIdentifierLocs();
986   Record.push_back(!IdentifierLocs.empty());
987   if (IdentifierLocs.empty()) {
988     Writer.AddSourceLocation(D->getLocEnd(), Record);
989     Record.push_back(1);
990   } else {
991     for (unsigned I = 0, N = IdentifierLocs.size(); I != N; ++I)
992       Writer.AddSourceLocation(IdentifierLocs[I], Record);
993     Record.push_back(IdentifierLocs.size());
994   }
995   // Note: the number of source locations must always be the last element in
996   // the record.
997   Code = serialization::DECL_IMPORT;
998 }
999 
1000 void ASTDeclWriter::VisitAccessSpecDecl(AccessSpecDecl *D) {
1001   VisitDecl(D);
1002   Writer.AddSourceLocation(D->getColonLoc(), Record);
1003   Code = serialization::DECL_ACCESS_SPEC;
1004 }
1005 
1006 void ASTDeclWriter::VisitFriendDecl(FriendDecl *D) {
1007   VisitDecl(D);
1008   Record.push_back(D->Friend.is<TypeSourceInfo*>());
1009   if (D->Friend.is<TypeSourceInfo*>())
1010     Writer.AddTypeSourceInfo(D->Friend.get<TypeSourceInfo*>(), Record);
1011   else
1012     Writer.AddDeclRef(D->Friend.get<NamedDecl*>(), Record);
1013   Writer.AddDeclRef(D->getNextFriend(), Record);
1014   Record.push_back(D->UnsupportedFriend);
1015   Writer.AddSourceLocation(D->FriendLoc, Record);
1016   Code = serialization::DECL_FRIEND;
1017 }
1018 
1019 void ASTDeclWriter::VisitFriendTemplateDecl(FriendTemplateDecl *D) {
1020   VisitDecl(D);
1021   Record.push_back(D->getNumTemplateParameters());
1022   for (unsigned i = 0, e = D->getNumTemplateParameters(); i != e; ++i)
1023     Writer.AddTemplateParameterList(D->getTemplateParameterList(i), Record);
1024   Record.push_back(D->getFriendDecl() != 0);
1025   if (D->getFriendDecl())
1026     Writer.AddDeclRef(D->getFriendDecl(), Record);
1027   else
1028     Writer.AddTypeSourceInfo(D->getFriendType(), Record);
1029   Writer.AddSourceLocation(D->getFriendLoc(), Record);
1030   Code = serialization::DECL_FRIEND_TEMPLATE;
1031 }
1032 
1033 void ASTDeclWriter::VisitTemplateDecl(TemplateDecl *D) {
1034   VisitNamedDecl(D);
1035 
1036   Writer.AddDeclRef(D->getTemplatedDecl(), Record);
1037   Writer.AddTemplateParameterList(D->getTemplateParameters(), Record);
1038 }
1039 
1040 void ASTDeclWriter::VisitRedeclarableTemplateDecl(RedeclarableTemplateDecl *D) {
1041   VisitRedeclarable(D);
1042 
1043   // Emit data to initialize CommonOrPrev before VisitTemplateDecl so that
1044   // getCommonPtr() can be used while this is still initializing.
1045   if (D->isFirstDeclaration()) {
1046     // This declaration owns the 'common' pointer, so serialize that data now.
1047     Writer.AddDeclRef(D->getInstantiatedFromMemberTemplate(), Record);
1048     if (D->getInstantiatedFromMemberTemplate())
1049       Record.push_back(D->isMemberSpecialization());
1050   }
1051 
1052   VisitTemplateDecl(D);
1053   Record.push_back(D->getIdentifierNamespace());
1054 }
1055 
1056 void ASTDeclWriter::VisitClassTemplateDecl(ClassTemplateDecl *D) {
1057   VisitRedeclarableTemplateDecl(D);
1058 
1059   if (D->isFirstDeclaration()) {
1060     typedef llvm::FoldingSetVector<ClassTemplateSpecializationDecl> CTSDSetTy;
1061     CTSDSetTy &CTSDSet = D->getSpecializations();
1062     Record.push_back(CTSDSet.size());
1063     for (CTSDSetTy::iterator I=CTSDSet.begin(), E = CTSDSet.end(); I!=E; ++I) {
1064       assert(I->isCanonicalDecl() && "Expected only canonical decls in set");
1065       Writer.AddDeclRef(&*I, Record);
1066     }
1067 
1068     typedef llvm::FoldingSetVector<ClassTemplatePartialSpecializationDecl>
1069       CTPSDSetTy;
1070     CTPSDSetTy &CTPSDSet = D->getPartialSpecializations();
1071     Record.push_back(CTPSDSet.size());
1072     for (CTPSDSetTy::iterator I=CTPSDSet.begin(), E=CTPSDSet.end(); I!=E; ++I) {
1073       assert(I->isCanonicalDecl() && "Expected only canonical decls in set");
1074       Writer.AddDeclRef(&*I, Record);
1075     }
1076 
1077     // InjectedClassNameType is computed, no need to write it.
1078   }
1079   Code = serialization::DECL_CLASS_TEMPLATE;
1080 }
1081 
1082 void ASTDeclWriter::VisitClassTemplateSpecializationDecl(
1083                                            ClassTemplateSpecializationDecl *D) {
1084   VisitCXXRecordDecl(D);
1085 
1086   llvm::PointerUnion<ClassTemplateDecl *,
1087                      ClassTemplatePartialSpecializationDecl *> InstFrom
1088     = D->getSpecializedTemplateOrPartial();
1089   if (Decl *InstFromD = InstFrom.dyn_cast<ClassTemplateDecl *>()) {
1090     Writer.AddDeclRef(InstFromD, Record);
1091   } else {
1092     Writer.AddDeclRef(InstFrom.get<ClassTemplatePartialSpecializationDecl *>(),
1093                       Record);
1094     Writer.AddTemplateArgumentList(&D->getTemplateInstantiationArgs(), Record);
1095   }
1096 
1097   // Explicit info.
1098   Writer.AddTypeSourceInfo(D->getTypeAsWritten(), Record);
1099   if (D->getTypeAsWritten()) {
1100     Writer.AddSourceLocation(D->getExternLoc(), Record);
1101     Writer.AddSourceLocation(D->getTemplateKeywordLoc(), Record);
1102   }
1103 
1104   Writer.AddTemplateArgumentList(&D->getTemplateArgs(), Record);
1105   Writer.AddSourceLocation(D->getPointOfInstantiation(), Record);
1106   Record.push_back(D->getSpecializationKind());
1107 
1108   if (D->isCanonicalDecl()) {
1109     // When reading, we'll add it to the folding set of the following template.
1110     Writer.AddDeclRef(D->getSpecializedTemplate()->getCanonicalDecl(), Record);
1111   }
1112 
1113   Code = serialization::DECL_CLASS_TEMPLATE_SPECIALIZATION;
1114 }
1115 
1116 void ASTDeclWriter::VisitClassTemplatePartialSpecializationDecl(
1117                                     ClassTemplatePartialSpecializationDecl *D) {
1118   VisitClassTemplateSpecializationDecl(D);
1119 
1120   Writer.AddTemplateParameterList(D->getTemplateParameters(), Record);
1121 
1122   Record.push_back(D->getNumTemplateArgsAsWritten());
1123   for (int i = 0, e = D->getNumTemplateArgsAsWritten(); i != e; ++i)
1124     Writer.AddTemplateArgumentLoc(D->getTemplateArgsAsWritten()[i], Record);
1125 
1126   Record.push_back(D->getSequenceNumber());
1127 
1128   // These are read/set from/to the first declaration.
1129   if (D->getPreviousDecl() == 0) {
1130     Writer.AddDeclRef(D->getInstantiatedFromMember(), Record);
1131     Record.push_back(D->isMemberSpecialization());
1132   }
1133 
1134   Code = serialization::DECL_CLASS_TEMPLATE_PARTIAL_SPECIALIZATION;
1135 }
1136 
1137 void ASTDeclWriter::VisitClassScopeFunctionSpecializationDecl(
1138                                     ClassScopeFunctionSpecializationDecl *D) {
1139   VisitDecl(D);
1140   Writer.AddDeclRef(D->getSpecialization(), Record);
1141   Code = serialization::DECL_CLASS_SCOPE_FUNCTION_SPECIALIZATION;
1142 }
1143 
1144 
1145 void ASTDeclWriter::VisitFunctionTemplateDecl(FunctionTemplateDecl *D) {
1146   VisitRedeclarableTemplateDecl(D);
1147 
1148   if (D->isFirstDeclaration()) {
1149     // This FunctionTemplateDecl owns the CommonPtr; write it.
1150 
1151     // Write the function specialization declarations.
1152     Record.push_back(D->getSpecializations().size());
1153     for (llvm::FoldingSetVector<FunctionTemplateSpecializationInfo>::iterator
1154            I = D->getSpecializations().begin(),
1155            E = D->getSpecializations().end()   ; I != E; ++I) {
1156       assert(I->Function->isCanonicalDecl() &&
1157              "Expected only canonical decls in set");
1158       Writer.AddDeclRef(I->Function, Record);
1159     }
1160   }
1161   Code = serialization::DECL_FUNCTION_TEMPLATE;
1162 }
1163 
1164 void ASTDeclWriter::VisitTemplateTypeParmDecl(TemplateTypeParmDecl *D) {
1165   VisitTypeDecl(D);
1166 
1167   Record.push_back(D->wasDeclaredWithTypename());
1168   Record.push_back(D->defaultArgumentWasInherited());
1169   Writer.AddTypeSourceInfo(D->getDefaultArgumentInfo(), Record);
1170 
1171   Code = serialization::DECL_TEMPLATE_TYPE_PARM;
1172 }
1173 
1174 void ASTDeclWriter::VisitNonTypeTemplateParmDecl(NonTypeTemplateParmDecl *D) {
1175   // For an expanded parameter pack, record the number of expansion types here
1176   // so that it's easier for
1177   if (D->isExpandedParameterPack())
1178     Record.push_back(D->getNumExpansionTypes());
1179 
1180   VisitDeclaratorDecl(D);
1181   // TemplateParmPosition.
1182   Record.push_back(D->getDepth());
1183   Record.push_back(D->getPosition());
1184 
1185   if (D->isExpandedParameterPack()) {
1186     for (unsigned I = 0, N = D->getNumExpansionTypes(); I != N; ++I) {
1187       Writer.AddTypeRef(D->getExpansionType(I), Record);
1188       Writer.AddTypeSourceInfo(D->getExpansionTypeSourceInfo(I), Record);
1189     }
1190 
1191     Code = serialization::DECL_EXPANDED_NON_TYPE_TEMPLATE_PARM_PACK;
1192   } else {
1193     // Rest of NonTypeTemplateParmDecl.
1194     Record.push_back(D->isParameterPack());
1195     Record.push_back(D->getDefaultArgument() != 0);
1196     if (D->getDefaultArgument()) {
1197       Writer.AddStmt(D->getDefaultArgument());
1198       Record.push_back(D->defaultArgumentWasInherited());
1199     }
1200     Code = serialization::DECL_NON_TYPE_TEMPLATE_PARM;
1201   }
1202 }
1203 
1204 void ASTDeclWriter::VisitTemplateTemplateParmDecl(TemplateTemplateParmDecl *D) {
1205   VisitTemplateDecl(D);
1206   // TemplateParmPosition.
1207   Record.push_back(D->getDepth());
1208   Record.push_back(D->getPosition());
1209   // Rest of TemplateTemplateParmDecl.
1210   Writer.AddTemplateArgumentLoc(D->getDefaultArgument(), Record);
1211   Record.push_back(D->defaultArgumentWasInherited());
1212   Record.push_back(D->isParameterPack());
1213   Code = serialization::DECL_TEMPLATE_TEMPLATE_PARM;
1214 }
1215 
1216 void ASTDeclWriter::VisitTypeAliasTemplateDecl(TypeAliasTemplateDecl *D) {
1217   VisitRedeclarableTemplateDecl(D);
1218   Code = serialization::DECL_TYPE_ALIAS_TEMPLATE;
1219 }
1220 
1221 void ASTDeclWriter::VisitStaticAssertDecl(StaticAssertDecl *D) {
1222   VisitDecl(D);
1223   Writer.AddStmt(D->getAssertExpr());
1224   Writer.AddStmt(D->getMessage());
1225   Writer.AddSourceLocation(D->getRParenLoc(), Record);
1226   Code = serialization::DECL_STATIC_ASSERT;
1227 }
1228 
1229 /// \brief Emit the DeclContext part of a declaration context decl.
1230 ///
1231 /// \param LexicalOffset the offset at which the DECL_CONTEXT_LEXICAL
1232 /// block for this declaration context is stored. May be 0 to indicate
1233 /// that there are no declarations stored within this context.
1234 ///
1235 /// \param VisibleOffset the offset at which the DECL_CONTEXT_VISIBLE
1236 /// block for this declaration context is stored. May be 0 to indicate
1237 /// that there are no declarations visible from this context. Note
1238 /// that this value will not be emitted for non-primary declaration
1239 /// contexts.
1240 void ASTDeclWriter::VisitDeclContext(DeclContext *DC, uint64_t LexicalOffset,
1241                                      uint64_t VisibleOffset) {
1242   Record.push_back(LexicalOffset);
1243   Record.push_back(VisibleOffset);
1244 }
1245 
1246 template <typename T>
1247 void ASTDeclWriter::VisitRedeclarable(Redeclarable<T> *D) {
1248   T *First = D->getFirstDeclaration();
1249   if (First->getMostRecentDecl() != First) {
1250     // There is more than one declaration of this entity, so we will need to
1251     // write a redeclaration chain.
1252     Writer.AddDeclRef(First, Record);
1253     Writer.Redeclarations.insert(First);
1254 
1255     // Make sure that we serialize both the previous and the most-recent
1256     // declarations, which (transitively) ensures that all declarations in the
1257     // chain get serialized.
1258     (void)Writer.GetDeclRef(D->getPreviousDecl());
1259     (void)Writer.GetDeclRef(First->getMostRecentDecl());
1260   } else {
1261     // We use the sentinel value 0 to indicate an only declaration.
1262     Record.push_back(0);
1263   }
1264 
1265 }
1266 
1267 //===----------------------------------------------------------------------===//
1268 // ASTWriter Implementation
1269 //===----------------------------------------------------------------------===//
1270 
1271 void ASTWriter::WriteDeclsBlockAbbrevs() {
1272   using namespace llvm;
1273 
1274   BitCodeAbbrev *Abv;
1275 
1276   // Abbreviation for DECL_FIELD
1277   Abv = new BitCodeAbbrev();
1278   Abv->Add(BitCodeAbbrevOp(serialization::DECL_FIELD));
1279   // Decl
1280   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclContext
1281   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LexicalDeclContext
1282   Abv->Add(BitCodeAbbrevOp(0));                       // isInvalidDecl
1283   Abv->Add(BitCodeAbbrevOp(0));                       // HasAttrs
1284   Abv->Add(BitCodeAbbrevOp(0));                       // isImplicit
1285   Abv->Add(BitCodeAbbrevOp(0));                       // isUsed
1286   Abv->Add(BitCodeAbbrevOp(0));                       // isReferenced
1287   Abv->Add(BitCodeAbbrevOp(0));                   // TopLevelDeclInObjCContainer
1288   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2));  // AccessSpecifier
1289   Abv->Add(BitCodeAbbrevOp(0));                       // ModulePrivate
1290   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // SubmoduleID
1291   // NamedDecl
1292   Abv->Add(BitCodeAbbrevOp(0));                       // NameKind = Identifier
1293   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Name
1294   // ValueDecl
1295   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
1296   // DeclaratorDecl
1297   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // InnerStartLoc
1298   Abv->Add(BitCodeAbbrevOp(0));                       // hasExtInfo
1299   // FieldDecl
1300   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isMutable
1301   Abv->Add(BitCodeAbbrevOp(0));                       //getBitWidth
1302   // Type Source Info
1303   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1304   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1305   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // TypeLoc
1306   DeclFieldAbbrev = Stream.EmitAbbrev(Abv);
1307 
1308   // Abbreviation for DECL_OBJC_IVAR
1309   Abv = new BitCodeAbbrev();
1310   Abv->Add(BitCodeAbbrevOp(serialization::DECL_OBJC_IVAR));
1311   // Decl
1312   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclContext
1313   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LexicalDeclContext
1314   Abv->Add(BitCodeAbbrevOp(0));                       // isInvalidDecl
1315   Abv->Add(BitCodeAbbrevOp(0));                       // HasAttrs
1316   Abv->Add(BitCodeAbbrevOp(0));                       // isImplicit
1317   Abv->Add(BitCodeAbbrevOp(0));                       // isUsed
1318   Abv->Add(BitCodeAbbrevOp(0));                       // isReferenced
1319   Abv->Add(BitCodeAbbrevOp(0));                   // TopLevelDeclInObjCContainer
1320   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2));  // AccessSpecifier
1321   Abv->Add(BitCodeAbbrevOp(0));                       // ModulePrivate
1322   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // SubmoduleID
1323   // NamedDecl
1324   Abv->Add(BitCodeAbbrevOp(0));                       // NameKind = Identifier
1325   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Name
1326   // ValueDecl
1327   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
1328   // DeclaratorDecl
1329   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // InnerStartLoc
1330   Abv->Add(BitCodeAbbrevOp(0));                       // hasExtInfo
1331   // FieldDecl
1332   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isMutable
1333   Abv->Add(BitCodeAbbrevOp(0));                       //getBitWidth
1334   // ObjC Ivar
1335   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // getAccessControl
1336   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // getSynthesize
1337   // Type Source Info
1338   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1339   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1340   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // TypeLoc
1341   DeclObjCIvarAbbrev = Stream.EmitAbbrev(Abv);
1342 
1343   // Abbreviation for DECL_ENUM
1344   Abv = new BitCodeAbbrev();
1345   Abv->Add(BitCodeAbbrevOp(serialization::DECL_ENUM));
1346   // Redeclarable
1347   Abv->Add(BitCodeAbbrevOp(0));                       // No redeclaration
1348   // Decl
1349   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclContext
1350   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LexicalDeclContext
1351   Abv->Add(BitCodeAbbrevOp(0));                       // isInvalidDecl
1352   Abv->Add(BitCodeAbbrevOp(0));                       // HasAttrs
1353   Abv->Add(BitCodeAbbrevOp(0));                       // isImplicit
1354   Abv->Add(BitCodeAbbrevOp(0));                       // isUsed
1355   Abv->Add(BitCodeAbbrevOp(0));                       // isReferenced
1356   Abv->Add(BitCodeAbbrevOp(0));                   // TopLevelDeclInObjCContainer
1357   Abv->Add(BitCodeAbbrevOp(AS_none));                 // C++ AccessSpecifier
1358   Abv->Add(BitCodeAbbrevOp(0));                       // ModulePrivate
1359   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // SubmoduleID
1360   // NamedDecl
1361   Abv->Add(BitCodeAbbrevOp(0));                       // NameKind = Identifier
1362   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Name
1363   // TypeDecl
1364   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Source Location
1365   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type Ref
1366   // TagDecl
1367   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // IdentifierNamespace
1368   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // getTagKind
1369   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isCompleteDefinition
1370   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // EmbeddedInDeclarator
1371   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsFreeStanding
1372   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // SourceLocation
1373   Abv->Add(BitCodeAbbrevOp(0));                         // hasExtInfo
1374   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // TypedefNameAnonDecl
1375   // EnumDecl
1376   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // AddTypeRef
1377   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // IntegerType
1378   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // getPromotionType
1379   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // getNumPositiveBits
1380   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // getNumNegativeBits
1381   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isScoped
1382   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isScopedUsingClassTag
1383   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isFixed
1384   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // InstantiatedMembEnum
1385   // DC
1386   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // LexicalOffset
1387   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // VisibleOffset
1388   DeclEnumAbbrev = Stream.EmitAbbrev(Abv);
1389 
1390   // Abbreviation for DECL_RECORD
1391   Abv = new BitCodeAbbrev();
1392   Abv->Add(BitCodeAbbrevOp(serialization::DECL_RECORD));
1393   // Redeclarable
1394   Abv->Add(BitCodeAbbrevOp(0));                       // No redeclaration
1395   // Decl
1396   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclContext
1397   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LexicalDeclContext
1398   Abv->Add(BitCodeAbbrevOp(0));                       // isInvalidDecl
1399   Abv->Add(BitCodeAbbrevOp(0));                       // HasAttrs
1400   Abv->Add(BitCodeAbbrevOp(0));                       // isImplicit
1401   Abv->Add(BitCodeAbbrevOp(0));                       // isUsed
1402   Abv->Add(BitCodeAbbrevOp(0));                       // isReferenced
1403   Abv->Add(BitCodeAbbrevOp(0));                   // TopLevelDeclInObjCContainer
1404   Abv->Add(BitCodeAbbrevOp(AS_none));                 // C++ AccessSpecifier
1405   Abv->Add(BitCodeAbbrevOp(0));                       // ModulePrivate
1406   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // SubmoduleID
1407   // NamedDecl
1408   Abv->Add(BitCodeAbbrevOp(0));                       // NameKind = Identifier
1409   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Name
1410   // TypeDecl
1411   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Source Location
1412   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type Ref
1413   // TagDecl
1414   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // IdentifierNamespace
1415   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // getTagKind
1416   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isCompleteDefinition
1417   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // EmbeddedInDeclarator
1418   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsFreeStanding
1419   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // SourceLocation
1420   Abv->Add(BitCodeAbbrevOp(0));                         // hasExtInfo
1421   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // TypedefNameAnonDecl
1422   // RecordDecl
1423   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // FlexibleArrayMember
1424   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // AnonymousStructUnion
1425   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // hasObjectMember
1426   // DC
1427   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // LexicalOffset
1428   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // VisibleOffset
1429   DeclRecordAbbrev = Stream.EmitAbbrev(Abv);
1430 
1431   // Abbreviation for DECL_PARM_VAR
1432   Abv = new BitCodeAbbrev();
1433   Abv->Add(BitCodeAbbrevOp(serialization::DECL_PARM_VAR));
1434   // Redeclarable
1435   Abv->Add(BitCodeAbbrevOp(0));                       // No redeclaration
1436   // Decl
1437   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclContext
1438   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LexicalDeclContext
1439   Abv->Add(BitCodeAbbrevOp(0));                       // isInvalidDecl
1440   Abv->Add(BitCodeAbbrevOp(0));                       // HasAttrs
1441   Abv->Add(BitCodeAbbrevOp(0));                       // isImplicit
1442   Abv->Add(BitCodeAbbrevOp(0));                       // isUsed
1443   Abv->Add(BitCodeAbbrevOp(0));                       // isReferenced
1444   Abv->Add(BitCodeAbbrevOp(0));                   // TopLevelDeclInObjCContainer
1445   Abv->Add(BitCodeAbbrevOp(AS_none));                 // C++ AccessSpecifier
1446   Abv->Add(BitCodeAbbrevOp(0));                       // ModulePrivate
1447   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // SubmoduleID
1448   // NamedDecl
1449   Abv->Add(BitCodeAbbrevOp(0));                       // NameKind = Identifier
1450   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Name
1451   // ValueDecl
1452   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
1453   // DeclaratorDecl
1454   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // InnerStartLoc
1455   Abv->Add(BitCodeAbbrevOp(0));                       // hasExtInfo
1456   // VarDecl
1457   Abv->Add(BitCodeAbbrevOp(0));                       // StorageClass
1458   Abv->Add(BitCodeAbbrevOp(0));                       // StorageClassAsWritten
1459   Abv->Add(BitCodeAbbrevOp(0));                       // isThreadSpecified
1460   Abv->Add(BitCodeAbbrevOp(0));                       // hasCXXDirectInitializer
1461   Abv->Add(BitCodeAbbrevOp(0));                       // isExceptionVariable
1462   Abv->Add(BitCodeAbbrevOp(0));                       // isNRVOVariable
1463   Abv->Add(BitCodeAbbrevOp(0));                       // isCXXForRangeDecl
1464   Abv->Add(BitCodeAbbrevOp(0));                       // isARCPseudoStrong
1465   Abv->Add(BitCodeAbbrevOp(0));                       // HasInit
1466   Abv->Add(BitCodeAbbrevOp(0));                   // HasMemberSpecializationInfo
1467   // ParmVarDecl
1468   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsObjCMethodParameter
1469   Abv->Add(BitCodeAbbrevOp(0));                       // ScopeDepth
1470   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // ScopeIndex
1471   Abv->Add(BitCodeAbbrevOp(0));                       // ObjCDeclQualifier
1472   Abv->Add(BitCodeAbbrevOp(0));                       // KNRPromoted
1473   Abv->Add(BitCodeAbbrevOp(0));                       // HasInheritedDefaultArg
1474   Abv->Add(BitCodeAbbrevOp(0));                   // HasUninstantiatedDefaultArg
1475   // Type Source Info
1476   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1477   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1478   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // TypeLoc
1479   DeclParmVarAbbrev = Stream.EmitAbbrev(Abv);
1480 
1481   // Abbreviation for DECL_TYPEDEF
1482   Abv = new BitCodeAbbrev();
1483   Abv->Add(BitCodeAbbrevOp(serialization::DECL_TYPEDEF));
1484   // Redeclarable
1485   Abv->Add(BitCodeAbbrevOp(0));                       // No redeclaration
1486   // Decl
1487   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclContext
1488   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LexicalDeclContext
1489   Abv->Add(BitCodeAbbrevOp(0));                       // isInvalidDecl
1490   Abv->Add(BitCodeAbbrevOp(0));                       // HasAttrs
1491   Abv->Add(BitCodeAbbrevOp(0));                       // isImplicit
1492   Abv->Add(BitCodeAbbrevOp(0));                       // isUsed
1493   Abv->Add(BitCodeAbbrevOp(0));                       // isReferenced
1494   Abv->Add(BitCodeAbbrevOp(0));                   // TopLevelDeclInObjCContainer
1495   Abv->Add(BitCodeAbbrevOp(AS_none));                 // C++ AccessSpecifier
1496   Abv->Add(BitCodeAbbrevOp(0));                       // ModulePrivate
1497   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // SubmoduleID
1498   // NamedDecl
1499   Abv->Add(BitCodeAbbrevOp(0));                       // NameKind = Identifier
1500   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Name
1501   // TypeDecl
1502   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Source Location
1503   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type Ref
1504   // TypedefDecl
1505   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1506   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // TypeLoc
1507   DeclTypedefAbbrev = Stream.EmitAbbrev(Abv);
1508 
1509   // Abbreviation for DECL_VAR
1510   Abv = new BitCodeAbbrev();
1511   Abv->Add(BitCodeAbbrevOp(serialization::DECL_VAR));
1512   // Redeclarable
1513   Abv->Add(BitCodeAbbrevOp(0));                       // No redeclaration
1514   // Decl
1515   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclContext
1516   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LexicalDeclContext
1517   Abv->Add(BitCodeAbbrevOp(0));                       // isInvalidDecl
1518   Abv->Add(BitCodeAbbrevOp(0));                       // HasAttrs
1519   Abv->Add(BitCodeAbbrevOp(0));                       // isImplicit
1520   Abv->Add(BitCodeAbbrevOp(0));                       // isUsed
1521   Abv->Add(BitCodeAbbrevOp(0));                       // isReferenced
1522   Abv->Add(BitCodeAbbrevOp(0));                   // TopLevelDeclInObjCContainer
1523   Abv->Add(BitCodeAbbrevOp(AS_none));                 // C++ AccessSpecifier
1524   Abv->Add(BitCodeAbbrevOp(0));                       // ModulePrivate
1525   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // SubmoduleID
1526   // NamedDecl
1527   Abv->Add(BitCodeAbbrevOp(0));                       // NameKind = Identifier
1528   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Name
1529   // ValueDecl
1530   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
1531   // DeclaratorDecl
1532   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // InnerStartLoc
1533   Abv->Add(BitCodeAbbrevOp(0));                       // hasExtInfo
1534   // VarDecl
1535   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // StorageClass
1536   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // StorageClassAsWritten
1537   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isThreadSpecified
1538   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // CXXDirectInitializer
1539   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isExceptionVariable
1540   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isNRVOVariable
1541   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isCXXForRangeDecl
1542   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isARCPseudoStrong
1543   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // HasInit
1544   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // HasMemberSpecInfo
1545   // Type Source Info
1546   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1547   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1548   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // TypeLoc
1549   DeclVarAbbrev = Stream.EmitAbbrev(Abv);
1550 
1551   // Abbreviation for EXPR_DECL_REF
1552   Abv = new BitCodeAbbrev();
1553   Abv->Add(BitCodeAbbrevOp(serialization::EXPR_DECL_REF));
1554   //Stmt
1555   //Expr
1556   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
1557   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //TypeDependent
1558   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //ValueDependent
1559   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //InstantiationDependent
1560   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //UnexpandedParamPack
1561   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetValueKind
1562   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetObjectKind
1563   //DeclRefExpr
1564   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //HasQualifier
1565   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //GetDeclFound
1566   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //ExplicitTemplateArgs
1567   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //HadMultipleCandidates
1568   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //RefersToEnclosingLocal
1569   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclRef
1570   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Location
1571   DeclRefExprAbbrev = Stream.EmitAbbrev(Abv);
1572 
1573   // Abbreviation for EXPR_INTEGER_LITERAL
1574   Abv = new BitCodeAbbrev();
1575   Abv->Add(BitCodeAbbrevOp(serialization::EXPR_INTEGER_LITERAL));
1576   //Stmt
1577   //Expr
1578   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
1579   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //TypeDependent
1580   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //ValueDependent
1581   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //InstantiationDependent
1582   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //UnexpandedParamPack
1583   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetValueKind
1584   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetObjectKind
1585   //Integer Literal
1586   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Location
1587   Abv->Add(BitCodeAbbrevOp(32));                      // Bit Width
1588   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Value
1589   IntegerLiteralAbbrev = Stream.EmitAbbrev(Abv);
1590 
1591   // Abbreviation for EXPR_CHARACTER_LITERAL
1592   Abv = new BitCodeAbbrev();
1593   Abv->Add(BitCodeAbbrevOp(serialization::EXPR_CHARACTER_LITERAL));
1594   //Stmt
1595   //Expr
1596   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
1597   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //TypeDependent
1598   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //ValueDependent
1599   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //InstantiationDependent
1600   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //UnexpandedParamPack
1601   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetValueKind
1602   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetObjectKind
1603   //Character Literal
1604   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // getValue
1605   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Location
1606   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //IsWide
1607   CharacterLiteralAbbrev = Stream.EmitAbbrev(Abv);
1608 
1609   Abv = new BitCodeAbbrev();
1610   Abv->Add(BitCodeAbbrevOp(serialization::DECL_CONTEXT_LEXICAL));
1611   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
1612   DeclContextLexicalAbbrev = Stream.EmitAbbrev(Abv);
1613 
1614   Abv = new BitCodeAbbrev();
1615   Abv->Add(BitCodeAbbrevOp(serialization::DECL_CONTEXT_VISIBLE));
1616   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
1617   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
1618   DeclContextVisibleLookupAbbrev = Stream.EmitAbbrev(Abv);
1619 }
1620 
1621 /// isRequiredDecl - Check if this is a "required" Decl, which must be seen by
1622 /// consumers of the AST.
1623 ///
1624 /// Such decls will always be deserialized from the AST file, so we would like
1625 /// this to be as restrictive as possible. Currently the predicate is driven by
1626 /// code generation requirements, if other clients have a different notion of
1627 /// what is "required" then we may have to consider an alternate scheme where
1628 /// clients can iterate over the top-level decls and get information on them,
1629 /// without necessary deserializing them. We could explicitly require such
1630 /// clients to use a separate API call to "realize" the decl. This should be
1631 /// relatively painless since they would presumably only do it for top-level
1632 /// decls.
1633 static bool isRequiredDecl(const Decl *D, ASTContext &Context) {
1634   // An ObjCMethodDecl is never considered as "required" because its
1635   // implementation container always is.
1636 
1637   // File scoped assembly or obj-c implementation must be seen.
1638   if (isa<FileScopeAsmDecl>(D) || isa<ObjCImplDecl>(D))
1639     return true;
1640 
1641   return Context.DeclMustBeEmitted(D);
1642 }
1643 
1644 void ASTWriter::WriteDecl(ASTContext &Context, Decl *D) {
1645   // Switch case IDs are per Decl.
1646   ClearSwitchCaseIDs();
1647 
1648   RecordData Record;
1649   ASTDeclWriter W(*this, Context, Record);
1650 
1651   // Determine the ID for this declaration.
1652   serialization::DeclID ID;
1653   if (D->isFromASTFile())
1654     ID = getDeclID(D);
1655   else {
1656     serialization::DeclID &IDR = DeclIDs[D];
1657     if (IDR == 0)
1658       IDR = NextDeclID++;
1659 
1660     ID= IDR;
1661   }
1662 
1663   bool isReplacingADecl = ID < FirstDeclID;
1664 
1665   // If this declaration is also a DeclContext, write blocks for the
1666   // declarations that lexically stored inside its context and those
1667   // declarations that are visible from its context. These blocks
1668   // are written before the declaration itself so that we can put
1669   // their offsets into the record for the declaration.
1670   uint64_t LexicalOffset = 0;
1671   uint64_t VisibleOffset = 0;
1672   DeclContext *DC = dyn_cast<DeclContext>(D);
1673   if (DC) {
1674     if (isReplacingADecl) {
1675       // It is replacing a decl from a chained PCH; make sure that the
1676       // DeclContext is fully loaded.
1677       if (DC->hasExternalLexicalStorage())
1678         DC->LoadLexicalDeclsFromExternalStorage();
1679       if (DC->hasExternalVisibleStorage())
1680         Chain->completeVisibleDeclsMap(DC);
1681     }
1682     LexicalOffset = WriteDeclContextLexicalBlock(Context, DC);
1683     VisibleOffset = WriteDeclContextVisibleBlock(Context, DC);
1684   }
1685 
1686   if (isReplacingADecl) {
1687     // We're replacing a decl in a previous file.
1688     ReplacedDecls.push_back(ReplacedDeclInfo(ID, Stream.GetCurrentBitNo(),
1689                                              D->getLocation()));
1690   } else {
1691     unsigned Index = ID - FirstDeclID;
1692 
1693     // Record the offset for this declaration
1694     SourceLocation Loc = D->getLocation();
1695     if (DeclOffsets.size() == Index)
1696       DeclOffsets.push_back(DeclOffset(Loc, Stream.GetCurrentBitNo()));
1697     else if (DeclOffsets.size() < Index) {
1698       DeclOffsets.resize(Index+1);
1699       DeclOffsets[Index].setLocation(Loc);
1700       DeclOffsets[Index].BitOffset = Stream.GetCurrentBitNo();
1701     }
1702 
1703     SourceManager &SM = Context.getSourceManager();
1704     if (Loc.isValid() && SM.isLocalSourceLocation(Loc))
1705       associateDeclWithFile(D, ID);
1706   }
1707 
1708   // Build and emit a record for this declaration
1709   Record.clear();
1710   W.Code = (serialization::DeclCode)0;
1711   W.AbbrevToUse = 0;
1712   W.Visit(D);
1713   if (DC) W.VisitDeclContext(DC, LexicalOffset, VisibleOffset);
1714 
1715   if (!W.Code)
1716     llvm::report_fatal_error(StringRef("unexpected declaration kind '") +
1717                             D->getDeclKindName() + "'");
1718   Stream.EmitRecord(W.Code, Record, W.AbbrevToUse);
1719 
1720   // Flush any expressions that were written as part of this declaration.
1721   FlushStmts();
1722 
1723   // Flush C++ base specifiers, if there are any.
1724   FlushCXXBaseSpecifiers();
1725 
1726   // Note "external" declarations so that we can add them to a record in the
1727   // AST file later.
1728   //
1729   // FIXME: This should be renamed, the predicate is much more complicated.
1730   if (isRequiredDecl(D, Context))
1731     ExternalDefinitions.push_back(ID);
1732 }
1733