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