lib/Serialization/ASTWriterDecl.cpp

   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/AST/DeclVisitor.h"
  16 #include "clang/AST/DeclCXX.h"
  17 #include "clang/AST/DeclTemplate.h"
  18 #include "clang/AST/Expr.h"
  19 #include "clang/AST/DeclContextInternals.h"
  20 #include "llvm/ADT/Twine.h"
  21 #include "llvm/Bitcode/BitstreamWriter.h"
  22 #include "llvm/Support/ErrorHandling.h"
  23 using namespace clang;
  24
  25 //===----------------------------------------------------------------------===//
  26 // Declaration serialization
  27 //===----------------------------------------------------------------------===//
  28
  29 namespace clang {
  30   class ASTDeclWriter : public DeclVisitor<ASTDeclWriter, void> {
  31
  32     ASTWriter &Writer;
  33     ASTContext &Context;
  34     typedef ASTWriter::RecordData RecordData;
  35     RecordData &Record;
  36
  37   public:
  38     serialization::DeclCode Code;
  39     unsigned AbbrevToUse;
  40
  41     ASTDeclWriter(ASTWriter &Writer, ASTContext &Context, RecordData &Record)
  42       : Writer(Writer), Context(Context), Record(Record) {
  43     }
  44
  45     void Visit(Decl *D);
  46
  47     void VisitDecl(Decl *D);
  48     void VisitTranslationUnitDecl(TranslationUnitDecl *D);
  49     void VisitNamedDecl(NamedDecl *D);
  50     void VisitNamespaceDecl(NamespaceDecl *D);
  51     void VisitUsingDirectiveDecl(UsingDirectiveDecl *D);
  52     void VisitNamespaceAliasDecl(NamespaceAliasDecl *D);
  53     void VisitTypeDecl(TypeDecl *D);
  54     void VisitTypedefDecl(TypedefDecl *D);
  55     void VisitUnresolvedUsingTypenameDecl(UnresolvedUsingTypenameDecl *D);
  56     void VisitTagDecl(TagDecl *D);
  57     void VisitEnumDecl(EnumDecl *D);
  58     void VisitRecordDecl(RecordDecl *D);
  59     void VisitCXXRecordDecl(CXXRecordDecl *D);
  60     void VisitClassTemplateSpecializationDecl(
  61                                             ClassTemplateSpecializationDecl *D);
  62     void VisitClassTemplatePartialSpecializationDecl(
  63                                      ClassTemplatePartialSpecializationDecl *D);
  64     void VisitTemplateTypeParmDecl(TemplateTypeParmDecl *D);
  65     void VisitValueDecl(ValueDecl *D);
  66     void VisitEnumConstantDecl(EnumConstantDecl *D);
  67     void VisitUnresolvedUsingValueDecl(UnresolvedUsingValueDecl *D);
  68     void VisitDeclaratorDecl(DeclaratorDecl *D);
  69     void VisitFunctionDecl(FunctionDecl *D);
  70     void VisitCXXMethodDecl(CXXMethodDecl *D);
  71     void VisitCXXConstructorDecl(CXXConstructorDecl *D);
  72     void VisitCXXDestructorDecl(CXXDestructorDecl *D);
  73     void VisitCXXConversionDecl(CXXConversionDecl *D);
  74     void VisitFieldDecl(FieldDecl *D);
  75     void VisitIndirectFieldDecl(IndirectFieldDecl *D);
  76     void VisitVarDecl(VarDecl *D);
  77     void VisitImplicitParamDecl(ImplicitParamDecl *D);
  78     void VisitParmVarDecl(ParmVarDecl *D);
  79     void VisitNonTypeTemplateParmDecl(NonTypeTemplateParmDecl *D);
  80     void VisitTemplateDecl(TemplateDecl *D);
  81     void VisitRedeclarableTemplateDecl(RedeclarableTemplateDecl *D);
  82     void VisitClassTemplateDecl(ClassTemplateDecl *D);
  83     void VisitFunctionTemplateDecl(FunctionTemplateDecl *D);
  84     void VisitTemplateTemplateParmDecl(TemplateTemplateParmDecl *D);
  85     void VisitUsingDecl(UsingDecl *D);
  86     void VisitUsingShadowDecl(UsingShadowDecl *D);
  87     void VisitLinkageSpecDecl(LinkageSpecDecl *D);
  88     void VisitFileScopeAsmDecl(FileScopeAsmDecl *D);
  89     void VisitAccessSpecDecl(AccessSpecDecl *D);
  90     void VisitFriendDecl(FriendDecl *D);
  91     void VisitFriendTemplateDecl(FriendTemplateDecl *D);
  92     void VisitStaticAssertDecl(StaticAssertDecl *D);
  93     void VisitBlockDecl(BlockDecl *D);
  94
  95     void VisitDeclContext(DeclContext *DC, uint64_t LexicalOffset,
  96                           uint64_t VisibleOffset);
  97     template <typename T> void VisitRedeclarable(Redeclarable<T> *D);
  98
  99
 100     // FIXME: Put in the same order is DeclNodes.td?
 101     void VisitObjCMethodDecl(ObjCMethodDecl *D);
 102     void VisitObjCContainerDecl(ObjCContainerDecl *D);
 103     void VisitObjCInterfaceDecl(ObjCInterfaceDecl *D);
 104     void VisitObjCIvarDecl(ObjCIvarDecl *D);
 105     void VisitObjCProtocolDecl(ObjCProtocolDecl *D);
 106     void VisitObjCAtDefsFieldDecl(ObjCAtDefsFieldDecl *D);
 107     void VisitObjCClassDecl(ObjCClassDecl *D);
 108     void VisitObjCForwardProtocolDecl(ObjCForwardProtocolDecl *D);
 109     void VisitObjCCategoryDecl(ObjCCategoryDecl *D);
 110     void VisitObjCImplDecl(ObjCImplDecl *D);
 111     void VisitObjCCategoryImplDecl(ObjCCategoryImplDecl *D);
 112     void VisitObjCImplementationDecl(ObjCImplementationDecl *D);
 113     void VisitObjCCompatibleAliasDecl(ObjCCompatibleAliasDecl *D);
 114     void VisitObjCPropertyDecl(ObjCPropertyDecl *D);
 115     void VisitObjCPropertyImplDecl(ObjCPropertyImplDecl *D);
 116   };
 117 }
 118
 119 void ASTDeclWriter::Visit(Decl *D) {
 120   DeclVisitor<ASTDeclWriter>::Visit(D);
 121
 122   // Handle FunctionDecl's body here and write it after all other Stmts/Exprs
 123   // have been written. We want it last because we will not read it back when
 124   // retrieving it from the AST, we'll just lazily set the offset.
 125   if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
 126     Record.push_back(FD->isThisDeclarationADefinition());
 127     if (FD->isThisDeclarationADefinition())
 128       Writer.AddStmt(FD->getBody());
 129   }
 130 }
 131
 132 void ASTDeclWriter::VisitDecl(Decl *D) {
 133   Writer.AddDeclRef(cast_or_null<Decl>(D->getDeclContext()), Record);
 134   Writer.AddDeclRef(cast_or_null<Decl>(D->getLexicalDeclContext()), Record);
 135   Writer.AddSourceLocation(D->getLocation(), Record);
 136   Record.push_back(D->isInvalidDecl());
 137   Record.push_back(D->hasAttrs());
 138   if (D->hasAttrs())
 139     Writer.WriteAttributes(D->getAttrs(), Record);
 140   Record.push_back(D->isImplicit());
 141   Record.push_back(D->isUsed(false));
 142   Record.push_back(D->getAccess());
 143   Record.push_back(D->getPCHLevel());
 144 }
 145
 146 void ASTDeclWriter::VisitTranslationUnitDecl(TranslationUnitDecl *D) {
 147   VisitDecl(D);
 148   Writer.AddDeclRef(D->getAnonymousNamespace(), Record);
 149   Code = serialization::DECL_TRANSLATION_UNIT;
 150 }
 151
 152 void ASTDeclWriter::VisitNamedDecl(NamedDecl *D) {
 153   VisitDecl(D);
 154   Writer.AddDeclarationName(D->getDeclName(), Record);
 155 }
 156
 157 void ASTDeclWriter::VisitTypeDecl(TypeDecl *D) {
 158   VisitNamedDecl(D);
 159   Writer.AddTypeRef(QualType(D->getTypeForDecl(), 0), Record);
 160 }
 161
 162 void ASTDeclWriter::VisitTypedefDecl(TypedefDecl *D) {
 163   VisitTypeDecl(D);
 164   Writer.AddTypeSourceInfo(D->getTypeSourceInfo(), Record);
 165   Code = serialization::DECL_TYPEDEF;
 166 }
 167
 168 void ASTDeclWriter::VisitTagDecl(TagDecl *D) {
 169   VisitTypeDecl(D);
 170   VisitRedeclarable(D);
 171   Record.push_back(D->getIdentifierNamespace());
 172   Record.push_back((unsigned)D->getTagKind()); // FIXME: stable encoding
 173   Record.push_back(D->isDefinition());
 174   Record.push_back(D->isEmbeddedInDeclarator());
 175   Writer.AddSourceLocation(D->getRBraceLoc(), Record);
 176   Writer.AddSourceLocation(D->getTagKeywordLoc(), Record);
 177   Record.push_back(D->hasExtInfo());
 178   if (D->hasExtInfo())
 179     Writer.AddQualifierInfo(*D->getExtInfo(), Record);
 180   else
 181     Writer.AddDeclRef(D->getTypedefForAnonDecl(), Record);
 182 }
 183
 184 void ASTDeclWriter::VisitEnumDecl(EnumDecl *D) {
 185   VisitTagDecl(D);
 186   Writer.AddTypeSourceInfo(D->getIntegerTypeSourceInfo(), Record);
 187   if (!D->getIntegerTypeSourceInfo())
 188     Writer.AddTypeRef(D->getIntegerType(), Record);
 189   Writer.AddTypeRef(D->getPromotionType(), Record);
 190   Record.push_back(D->getNumPositiveBits());
 191   Record.push_back(D->getNumNegativeBits());
 192   Record.push_back(D->isScoped());
 193   Record.push_back(D->isScopedUsingClassTag());
 194   Record.push_back(D->isFixed());
 195   Writer.AddDeclRef(D->getInstantiatedFromMemberEnum(), Record);
 196   Code = serialization::DECL_ENUM;
 197 }
 198
 199 void ASTDeclWriter::VisitRecordDecl(RecordDecl *D) {
 200   VisitTagDecl(D);
 201   Record.push_back(D->hasFlexibleArrayMember());
 202   Record.push_back(D->isAnonymousStructOrUnion());
 203   Record.push_back(D->hasObjectMember());
 204   Code = serialization::DECL_RECORD;
 205 }
 206
 207 void ASTDeclWriter::VisitValueDecl(ValueDecl *D) {
 208   VisitNamedDecl(D);
 209   Writer.AddTypeRef(D->getType(), Record);
 210 }
 211
 212 void ASTDeclWriter::VisitEnumConstantDecl(EnumConstantDecl *D) {
 213   VisitValueDecl(D);
 214   Record.push_back(D->getInitExpr()? 1 : 0);
 215   if (D->getInitExpr())
 216     Writer.AddStmt(D->getInitExpr());
 217   Writer.AddAPSInt(D->getInitVal(), Record);
 218   Code = serialization::DECL_ENUM_CONSTANT;
 219 }
 220
 221 void ASTDeclWriter::VisitDeclaratorDecl(DeclaratorDecl *D) {
 222   VisitValueDecl(D);
 223   Record.push_back(D->hasExtInfo());
 224   if (D->hasExtInfo())
 225     Writer.AddQualifierInfo(*D->getExtInfo(), Record);
 226   Writer.AddTypeSourceInfo(D->getTypeSourceInfo(), Record);
 227 }
 228
 229 void ASTDeclWriter::VisitFunctionDecl(FunctionDecl *D) {
 230   VisitDeclaratorDecl(D);
 231   VisitRedeclarable(D);
 232
 233   Writer.AddDeclarationNameLoc(D->DNLoc, D->getDeclName(), Record);
 234   Record.push_back(D->getIdentifierNamespace());
 235   Record.push_back(D->getTemplatedKind());
 236   switch (D->getTemplatedKind()) {
 237   default: assert(false && "Unhandled TemplatedKind!");
 238     break;
 239   case FunctionDecl::TK_NonTemplate:
 240     break;
 241   case FunctionDecl::TK_FunctionTemplate:
 242     Writer.AddDeclRef(D->getDescribedFunctionTemplate(), Record);
 243     break;
 244   case FunctionDecl::TK_MemberSpecialization: {
 245     MemberSpecializationInfo *MemberInfo = D->getMemberSpecializationInfo();
 246     Writer.AddDeclRef(MemberInfo->getInstantiatedFrom(), Record);
 247     Record.push_back(MemberInfo->getTemplateSpecializationKind());
 248     Writer.AddSourceLocation(MemberInfo->getPointOfInstantiation(), Record);
 249     break;
 250   }
 251   case FunctionDecl::TK_FunctionTemplateSpecialization: {
 252     FunctionTemplateSpecializationInfo *
 253       FTSInfo = D->getTemplateSpecializationInfo();
 254     Writer.AddDeclRef(FTSInfo->getTemplate(), Record);
 255     Record.push_back(FTSInfo->getTemplateSpecializationKind());
 256
 257     // Template arguments.
 258     Writer.AddTemplateArgumentList(FTSInfo->TemplateArguments, Record);
 259
 260     // Template args as written.
 261     Record.push_back(FTSInfo->TemplateArgumentsAsWritten != 0);
 262     if (FTSInfo->TemplateArgumentsAsWritten) {
 263       Record.push_back(FTSInfo->TemplateArgumentsAsWritten->size());
 264       for (int i=0, e = FTSInfo->TemplateArgumentsAsWritten->size(); i!=e; ++i)
 265         Writer.AddTemplateArgumentLoc((*FTSInfo->TemplateArgumentsAsWritten)[i],
 266                                       Record);
 267       Writer.AddSourceLocation(FTSInfo->TemplateArgumentsAsWritten->getLAngleLoc(),
 268                                Record);
 269       Writer.AddSourceLocation(FTSInfo->TemplateArgumentsAsWritten->getRAngleLoc(),
 270                                Record);
 271     }
 272
 273     Writer.AddSourceLocation(FTSInfo->getPointOfInstantiation(), Record);
 274
 275     if (D->isCanonicalDecl()) {
 276       // Write the template that contains the specializations set. We will
 277       // add a FunctionTemplateSpecializationInfo to it when reading.
 278       Writer.AddDeclRef(FTSInfo->getTemplate()->getCanonicalDecl(), Record);
 279     }
 280     break;
 281   }
 282   case FunctionDecl::TK_DependentFunctionTemplateSpecialization: {
 283     DependentFunctionTemplateSpecializationInfo *
 284       DFTSInfo = D->getDependentSpecializationInfo();
 285
 286     // Templates.
 287     Record.push_back(DFTSInfo->getNumTemplates());
 288     for (int i=0, e = DFTSInfo->getNumTemplates(); i != e; ++i)
 289       Writer.AddDeclRef(DFTSInfo->getTemplate(i), Record);
 290
 291     // Templates args.
 292     Record.push_back(DFTSInfo->getNumTemplateArgs());
 293     for (int i=0, e = DFTSInfo->getNumTemplateArgs(); i != e; ++i)
 294       Writer.AddTemplateArgumentLoc(DFTSInfo->getTemplateArg(i), Record);
 295     Writer.AddSourceLocation(DFTSInfo->getLAngleLoc(), Record);
 296     Writer.AddSourceLocation(DFTSInfo->getRAngleLoc(), Record);
 297     break;
 298   }
 299   }
 300
 301   // FunctionDecl's body is handled last at ASTWriterDecl::Visit,
 302   // after everything else is written.
 303
 304   Record.push_back(D->getStorageClass()); // FIXME: stable encoding
 305   Record.push_back(D->getStorageClassAsWritten());
 306   Record.push_back(D->IsInline);
 307   Record.push_back(D->isInlineSpecified());
 308   Record.push_back(D->isVirtualAsWritten());
 309   Record.push_back(D->isPure());
 310   Record.push_back(D->hasInheritedPrototype());
 311   Record.push_back(D->hasWrittenPrototype());
 312   Record.push_back(D->isDeleted());
 313   Record.push_back(D->isTrivial());
 314   Record.push_back(D->hasImplicitReturnZero());
 315   Writer.AddSourceLocation(D->getLocEnd(), Record);
 316
 317   Record.push_back(D->param_size());
 318   for (FunctionDecl::param_iterator P = D->param_begin(), PEnd = D->param_end();
 319        P != PEnd; ++P)
 320     Writer.AddDeclRef(*P, Record);
 321   Code = serialization::DECL_FUNCTION;
 322 }
 323
 324 void ASTDeclWriter::VisitObjCMethodDecl(ObjCMethodDecl *D) {
 325   VisitNamedDecl(D);
 326   // FIXME: convert to LazyStmtPtr?
 327   // Unlike C/C++, method bodies will never be in header files.
 328   bool HasBodyStuff = D->getBody() != 0     ||
 329                       D->getSelfDecl() != 0 || D->getCmdDecl() != 0;
 330   Record.push_back(HasBodyStuff);
 331   if (HasBodyStuff) {
 332     Writer.AddStmt(D->getBody());
 333     Writer.AddDeclRef(D->getSelfDecl(), Record);
 334     Writer.AddDeclRef(D->getCmdDecl(), Record);
 335   }
 336   Record.push_back(D->isInstanceMethod());
 337   Record.push_back(D->isVariadic());
 338   Record.push_back(D->isSynthesized());
 339   Record.push_back(D->isDefined());
 340   // FIXME: stable encoding for @required/@optional
 341   Record.push_back(D->getImplementationControl());
 342   // FIXME: stable encoding for in/out/inout/bycopy/byref/oneway
 343   Record.push_back(D->getObjCDeclQualifier());
 344   Record.push_back(D->getNumSelectorArgs());
 345   Writer.AddTypeRef(D->getResultType(), Record);
 346   Writer.AddTypeSourceInfo(D->getResultTypeSourceInfo(), Record);
 347   Writer.AddSourceLocation(D->getLocEnd(), Record);
 348   Record.push_back(D->param_size());
 349   for (ObjCMethodDecl::param_iterator P = D->param_begin(),
 350                                    PEnd = D->param_end(); P != PEnd; ++P)
 351     Writer.AddDeclRef(*P, Record);
 352   Code = serialization::DECL_OBJC_METHOD;
 353 }
 354
 355 void ASTDeclWriter::VisitObjCContainerDecl(ObjCContainerDecl *D) {
 356   VisitNamedDecl(D);
 357   Writer.AddSourceRange(D->getAtEndRange(), Record);
 358   // Abstract class (no need to define a stable serialization::DECL code).
 359 }
 360
 361 void ASTDeclWriter::VisitObjCInterfaceDecl(ObjCInterfaceDecl *D) {
 362   VisitObjCContainerDecl(D);
 363   Writer.AddTypeRef(QualType(D->getTypeForDecl(), 0), Record);
 364   Writer.AddDeclRef(D->getSuperClass(), Record);
 365
 366   // Write out the protocols that are directly referenced by the @interface.
 367   Record.push_back(D->ReferencedProtocols.size());
 368   for (ObjCInterfaceDecl::protocol_iterator P = D->protocol_begin(),
 369          PEnd = D->protocol_end();
 370        P != PEnd; ++P)
 371     Writer.AddDeclRef(*P, Record);
 372   for (ObjCInterfaceDecl::protocol_loc_iterator PL = D->protocol_loc_begin(),
 373          PLEnd = D->protocol_loc_end();
 374        PL != PLEnd; ++PL)
 375     Writer.AddSourceLocation(*PL, Record);
 376
 377   // Write out the protocols that are transitively referenced.
 378   Record.push_back(D->AllReferencedProtocols.size());
 379   for (ObjCList<ObjCProtocolDecl>::iterator
 380         P = D->AllReferencedProtocols.begin(),
 381         PEnd = D->AllReferencedProtocols.end();
 382        P != PEnd; ++P)
 383     Writer.AddDeclRef(*P, Record);
 384
 385   // Write out the ivars.
 386   Record.push_back(D->ivar_size());
 387   for (ObjCInterfaceDecl::ivar_iterator I = D->ivar_begin(),
 388                                      IEnd = D->ivar_end(); I != IEnd; ++I)
 389     Writer.AddDeclRef(*I, Record);
 390   Writer.AddDeclRef(D->getCategoryList(), Record);
 391   Record.push_back(D->isForwardDecl());
 392   Record.push_back(D->isImplicitInterfaceDecl());
 393   Writer.AddSourceLocation(D->getClassLoc(), Record);
 394   Writer.AddSourceLocation(D->getSuperClassLoc(), Record);
 395   Writer.AddSourceLocation(D->getLocEnd(), Record);
 396   Code = serialization::DECL_OBJC_INTERFACE;
 397 }
 398
 399 void ASTDeclWriter::VisitObjCIvarDecl(ObjCIvarDecl *D) {
 400   VisitFieldDecl(D);
 401   // FIXME: stable encoding for @public/@private/@protected/@package
 402   Record.push_back(D->getAccessControl());
 403   Record.push_back(D->getSynthesize());
 404   Code = serialization::DECL_OBJC_IVAR;
 405 }
 406
 407 void ASTDeclWriter::VisitObjCProtocolDecl(ObjCProtocolDecl *D) {
 408   VisitObjCContainerDecl(D);
 409   Record.push_back(D->isForwardDecl());
 410   Writer.AddSourceLocation(D->getLocEnd(), Record);
 411   Record.push_back(D->protocol_size());
 412   for (ObjCProtocolDecl::protocol_iterator
 413        I = D->protocol_begin(), IEnd = D->protocol_end(); I != IEnd; ++I)
 414     Writer.AddDeclRef(*I, Record);
 415   for (ObjCProtocolDecl::protocol_loc_iterator PL = D->protocol_loc_begin(),
 416          PLEnd = D->protocol_loc_end();
 417        PL != PLEnd; ++PL)
 418     Writer.AddSourceLocation(*PL, Record);
 419   Code = serialization::DECL_OBJC_PROTOCOL;
 420 }
 421
 422 void ASTDeclWriter::VisitObjCAtDefsFieldDecl(ObjCAtDefsFieldDecl *D) {
 423   VisitFieldDecl(D);
 424   Code = serialization::DECL_OBJC_AT_DEFS_FIELD;
 425 }
 426
 427 void ASTDeclWriter::VisitObjCClassDecl(ObjCClassDecl *D) {
 428   VisitDecl(D);
 429   Record.push_back(D->size());
 430   for (ObjCClassDecl::iterator I = D->begin(), IEnd = D->end(); I != IEnd; ++I)
 431     Writer.AddDeclRef(I->getInterface(), Record);
 432   for (ObjCClassDecl::iterator I = D->begin(), IEnd = D->end(); I != IEnd; ++I)
 433     Writer.AddSourceLocation(I->getLocation(), Record);
 434   Code = serialization::DECL_OBJC_CLASS;
 435 }
 436
 437 void ASTDeclWriter::VisitObjCForwardProtocolDecl(ObjCForwardProtocolDecl *D) {
 438   VisitDecl(D);
 439   Record.push_back(D->protocol_size());
 440   for (ObjCForwardProtocolDecl::protocol_iterator
 441        I = D->protocol_begin(), IEnd = D->protocol_end(); I != IEnd; ++I)
 442     Writer.AddDeclRef(*I, Record);
 443   for (ObjCForwardProtocolDecl::protocol_loc_iterator
 444          PL = D->protocol_loc_begin(), PLEnd = D->protocol_loc_end();
 445        PL != PLEnd; ++PL)
 446     Writer.AddSourceLocation(*PL, Record);
 447   Code = serialization::DECL_OBJC_FORWARD_PROTOCOL;
 448 }
 449
 450 void ASTDeclWriter::VisitObjCCategoryDecl(ObjCCategoryDecl *D) {
 451   VisitObjCContainerDecl(D);
 452   Writer.AddDeclRef(D->getClassInterface(), Record);
 453   Record.push_back(D->protocol_size());
 454   for (ObjCCategoryDecl::protocol_iterator
 455        I = D->protocol_begin(), IEnd = D->protocol_end(); I != IEnd; ++I)
 456     Writer.AddDeclRef(*I, Record);
 457   for (ObjCCategoryDecl::protocol_loc_iterator
 458          PL = D->protocol_loc_begin(), PLEnd = D->protocol_loc_end();
 459        PL != PLEnd; ++PL)
 460     Writer.AddSourceLocation(*PL, Record);
 461   Writer.AddDeclRef(D->getNextClassCategory(), Record);
 462   Record.push_back(D->hasSynthBitfield());
 463   Writer.AddSourceLocation(D->getAtLoc(), Record);
 464   Writer.AddSourceLocation(D->getCategoryNameLoc(), Record);
 465   Code = serialization::DECL_OBJC_CATEGORY;
 466 }
 467
 468 void ASTDeclWriter::VisitObjCCompatibleAliasDecl(ObjCCompatibleAliasDecl *D) {
 469   VisitNamedDecl(D);
 470   Writer.AddDeclRef(D->getClassInterface(), Record);
 471   Code = serialization::DECL_OBJC_COMPATIBLE_ALIAS;
 472 }
 473
 474 void ASTDeclWriter::VisitObjCPropertyDecl(ObjCPropertyDecl *D) {
 475   VisitNamedDecl(D);
 476   Writer.AddSourceLocation(D->getAtLoc(), Record);
 477   Writer.AddTypeSourceInfo(D->getTypeSourceInfo(), Record);
 478   // FIXME: stable encoding
 479   Record.push_back((unsigned)D->getPropertyAttributes());
 480   Record.push_back((unsigned)D->getPropertyAttributesAsWritten());
 481   // FIXME: stable encoding
 482   Record.push_back((unsigned)D->getPropertyImplementation());
 483   Writer.AddDeclarationName(D->getGetterName(), Record);
 484   Writer.AddDeclarationName(D->getSetterName(), Record);
 485   Writer.AddDeclRef(D->getGetterMethodDecl(), Record);
 486   Writer.AddDeclRef(D->getSetterMethodDecl(), Record);
 487   Writer.AddDeclRef(D->getPropertyIvarDecl(), Record);
 488   Code = serialization::DECL_OBJC_PROPERTY;
 489 }
 490
 491 void ASTDeclWriter::VisitObjCImplDecl(ObjCImplDecl *D) {
 492   VisitObjCContainerDecl(D);
 493   Writer.AddDeclRef(D->getClassInterface(), Record);
 494   // Abstract class (no need to define a stable serialization::DECL code).
 495 }
 496
 497 void ASTDeclWriter::VisitObjCCategoryImplDecl(ObjCCategoryImplDecl *D) {
 498   VisitObjCImplDecl(D);
 499   Writer.AddIdentifierRef(D->getIdentifier(), Record);
 500   Code = serialization::DECL_OBJC_CATEGORY_IMPL;
 501 }
 502
 503 void ASTDeclWriter::VisitObjCImplementationDecl(ObjCImplementationDecl *D) {
 504   VisitObjCImplDecl(D);
 505   Writer.AddDeclRef(D->getSuperClass(), Record);
 506   Writer.AddCXXBaseOrMemberInitializers(D->IvarInitializers,
 507                                         D->NumIvarInitializers, Record);
 508   Record.push_back(D->hasSynthBitfield());
 509   Code = serialization::DECL_OBJC_IMPLEMENTATION;
 510 }
 511
 512 void ASTDeclWriter::VisitObjCPropertyImplDecl(ObjCPropertyImplDecl *D) {
 513   VisitDecl(D);
 514   Writer.AddSourceLocation(D->getLocStart(), Record);
 515   Writer.AddDeclRef(D->getPropertyDecl(), Record);
 516   Writer.AddDeclRef(D->getPropertyIvarDecl(), Record);
 517   Writer.AddSourceLocation(D->getPropertyIvarDeclLoc(), Record);
 518   Writer.AddStmt(D->getGetterCXXConstructor());
 519   Writer.AddStmt(D->getSetterCXXAssignment());
 520   Code = serialization::DECL_OBJC_PROPERTY_IMPL;
 521 }
 522
 523 void ASTDeclWriter::VisitFieldDecl(FieldDecl *D) {
 524   VisitDeclaratorDecl(D);
 525   Record.push_back(D->isMutable());
 526   Record.push_back(D->getBitWidth()? 1 : 0);
 527   if (D->getBitWidth())
 528     Writer.AddStmt(D->getBitWidth());
 529   if (!D->getDeclName())
 530     Writer.AddDeclRef(Context.getInstantiatedFromUnnamedFieldDecl(D), Record);
 531   Code = serialization::DECL_FIELD;
 532 }
 533
 534 void ASTDeclWriter::VisitIndirectFieldDecl(IndirectFieldDecl *D) {
 535   VisitValueDecl(D);
 536   Record.push_back(D->getChainingSize());
 537
 538   for (IndirectFieldDecl::chain_iterator
 539        P = D->chain_begin(),
 540        PEnd = D->chain_end(); P != PEnd; ++P)
 541     Writer.AddDeclRef(*P, Record);
 542   Code = serialization::DECL_INDIRECTFIELD;
 543 }
 544
 545 void ASTDeclWriter::VisitVarDecl(VarDecl *D) {
 546   VisitDeclaratorDecl(D);
 547   VisitRedeclarable(D);
 548   Record.push_back(D->getStorageClass()); // FIXME: stable encoding
 549   Record.push_back(D->getStorageClassAsWritten());
 550   Record.push_back(D->isThreadSpecified());
 551   Record.push_back(D->hasCXXDirectInitializer());
 552   Record.push_back(D->isExceptionVariable());
 553   Record.push_back(D->isNRVOVariable());
 554   Record.push_back(D->getInit() ? 1 : 0);
 555   if (D->getInit())
 556     Writer.AddStmt(D->getInit());
 557
 558   MemberSpecializationInfo *SpecInfo
 559     = D->isStaticDataMember() ? D->getMemberSpecializationInfo() : 0;
 560   Record.push_back(SpecInfo != 0);
 561   if (SpecInfo) {
 562     Writer.AddDeclRef(SpecInfo->getInstantiatedFrom(), Record);
 563     Record.push_back(SpecInfo->getTemplateSpecializationKind());
 564     Writer.AddSourceLocation(SpecInfo->getPointOfInstantiation(), Record);
 565   }
 566
 567   Code = serialization::DECL_VAR;
 568 }
 569
 570 void ASTDeclWriter::VisitImplicitParamDecl(ImplicitParamDecl *D) {
 571   VisitVarDecl(D);
 572   Code = serialization::DECL_IMPLICIT_PARAM;
 573 }
 574
 575 void ASTDeclWriter::VisitParmVarDecl(ParmVarDecl *D) {
 576   VisitVarDecl(D);
 577   Record.push_back(D->getObjCDeclQualifier()); // FIXME: stable encoding
 578   Record.push_back(D->hasInheritedDefaultArg());
 579   Record.push_back(D->hasUninstantiatedDefaultArg());
 580   if (D->hasUninstantiatedDefaultArg())
 581     Writer.AddStmt(D->getUninstantiatedDefaultArg());
 582   Code = serialization::DECL_PARM_VAR;
 583
 584   // If the assumptions about the DECL_PARM_VAR abbrev are true, use it.  Here
 585   // we dynamically check for the properties that we optimize for, but don't
 586   // know are true of all PARM_VAR_DECLs.
 587   if (!D->getTypeSourceInfo() &&
 588       !D->hasAttrs() &&
 589       !D->isImplicit() &&
 590       !D->isUsed(false) &&
 591       D->getAccess() == AS_none &&
 592       D->getPCHLevel() == 0 &&
 593       D->getStorageClass() == 0 &&
 594       !D->hasCXXDirectInitializer() && // Can params have this ever?
 595       D->getObjCDeclQualifier() == 0 &&
 596       !D->hasInheritedDefaultArg() &&
 597       D->getInit() == 0 &&
 598       !D->hasUninstantiatedDefaultArg())  // No default expr.
 599     AbbrevToUse = Writer.getParmVarDeclAbbrev();
 600
 601   // Check things we know are true of *every* PARM_VAR_DECL, which is more than
 602   // just us assuming it.
 603   assert(!D->isInvalidDecl() && "Shouldn't emit invalid decls");
 604   assert(!D->isThreadSpecified() && "PARM_VAR_DECL can't be __thread");
 605   assert(D->getAccess() == AS_none && "PARM_VAR_DECL can't be public/private");
 606   assert(!D->isExceptionVariable() && "PARM_VAR_DECL can't be exception var");
 607   assert(D->getPreviousDeclaration() == 0 && "PARM_VAR_DECL can't be redecl");
 608   assert(!D->isStaticDataMember() &&
 609          "PARM_VAR_DECL can't be static data member");
 610 }
 611
 612 void ASTDeclWriter::VisitFileScopeAsmDecl(FileScopeAsmDecl *D) {
 613   VisitDecl(D);
 614   Writer.AddStmt(D->getAsmString());
 615   Code = serialization::DECL_FILE_SCOPE_ASM;
 616 }
 617
 618 void ASTDeclWriter::VisitBlockDecl(BlockDecl *D) {
 619   VisitDecl(D);
 620   Writer.AddStmt(D->getBody());
 621   Writer.AddTypeSourceInfo(D->getSignatureAsWritten(), Record);
 622   Record.push_back(D->param_size());
 623   for (FunctionDecl::param_iterator P = D->param_begin(), PEnd = D->param_end();
 624        P != PEnd; ++P)
 625     Writer.AddDeclRef(*P, Record);
 626   Code = serialization::DECL_BLOCK;
 627 }
 628
 629 void ASTDeclWriter::VisitLinkageSpecDecl(LinkageSpecDecl *D) {
 630   VisitDecl(D);
 631   // FIXME: It might be nice to serialize the brace locations for this
 632   // declaration, which don't seem to be readily available in the AST.
 633   Record.push_back(D->getLanguage());
 634   Record.push_back(D->hasBraces());
 635   Code = serialization::DECL_LINKAGE_SPEC;
 636 }
 637
 638 void ASTDeclWriter::VisitNamespaceDecl(NamespaceDecl *D) {
 639   VisitNamedDecl(D);
 640   Record.push_back(D->isInline());
 641   Writer.AddSourceLocation(D->getLBracLoc(), Record);
 642   Writer.AddSourceLocation(D->getRBracLoc(), Record);
 643   Writer.AddDeclRef(D->getNextNamespace(), Record);
 644
 645   // Only write one reference--original or anonymous
 646   Record.push_back(D->isOriginalNamespace());
 647   if (D->isOriginalNamespace())
 648     Writer.AddDeclRef(D->getAnonymousNamespace(), Record);
 649   else
 650     Writer.AddDeclRef(D->getOriginalNamespace(), Record);
 651   Code = serialization::DECL_NAMESPACE;
 652
 653   if (Writer.hasChain() && !D->isOriginalNamespace() &&
 654       D->getOriginalNamespace()->getPCHLevel() > 0) {
 655     NamespaceDecl *NS = D->getOriginalNamespace();
 656     Writer.AddUpdatedDeclContext(NS);
 657
 658     // Make sure all visible decls are written. They will be recorded later.
 659     NS->lookup(DeclarationName());
 660     StoredDeclsMap *Map = static_cast<StoredDeclsMap*>(NS->getLookupPtr());
 661     if (Map) {
 662       for (StoredDeclsMap::iterator D = Map->begin(), DEnd = Map->end();
 663            D != DEnd; ++D) {
 664         DeclarationName Name = D->first;
 665         DeclContext::lookup_result Result = D->second.getLookupResult();
 666         while (Result.first != Result.second) {
 667           Writer.GetDeclRef(*Result.first);
 668           ++Result.first;
 669         }
 670       }
 671     }
 672   }
 673 }
 674
 675 void ASTDeclWriter::VisitNamespaceAliasDecl(NamespaceAliasDecl *D) {
 676   VisitNamedDecl(D);
 677   Writer.AddSourceLocation(D->getNamespaceLoc(), Record);
 678   Writer.AddSourceRange(D->getQualifierRange(), Record);
 679   Writer.AddNestedNameSpecifier(D->getQualifier(), Record);
 680   Writer.AddSourceLocation(D->getTargetNameLoc(), Record);
 681   Writer.AddDeclRef(D->getNamespace(), Record);
 682   Code = serialization::DECL_NAMESPACE_ALIAS;
 683 }
 684
 685 void ASTDeclWriter::VisitUsingDecl(UsingDecl *D) {
 686   VisitNamedDecl(D);
 687   Writer.AddSourceRange(D->getNestedNameRange(), Record);
 688   Writer.AddSourceLocation(D->getUsingLocation(), Record);
 689   Writer.AddNestedNameSpecifier(D->getTargetNestedNameDecl(), Record);
 690   Writer.AddDeclarationNameLoc(D->DNLoc, D->getDeclName(), Record);
 691   Writer.AddDeclRef(D->FirstUsingShadow, Record);
 692   Record.push_back(D->isTypeName());
 693   Writer.AddDeclRef(Context.getInstantiatedFromUsingDecl(D), Record);
 694   Code = serialization::DECL_USING;
 695 }
 696
 697 void ASTDeclWriter::VisitUsingShadowDecl(UsingShadowDecl *D) {
 698   VisitNamedDecl(D);
 699   Writer.AddDeclRef(D->getTargetDecl(), Record);
 700   Writer.AddDeclRef(D->UsingOrNextShadow, Record);
 701   Writer.AddDeclRef(Context.getInstantiatedFromUsingShadowDecl(D), Record);
 702   Code = serialization::DECL_USING_SHADOW;
 703 }
 704
 705 void ASTDeclWriter::VisitUsingDirectiveDecl(UsingDirectiveDecl *D) {
 706   VisitNamedDecl(D);
 707   Writer.AddSourceLocation(D->getUsingLoc(), Record);
 708   Writer.AddSourceLocation(D->getNamespaceKeyLocation(), Record);
 709   Writer.AddSourceRange(D->getQualifierRange(), Record);
 710   Writer.AddNestedNameSpecifier(D->getQualifier(), Record);
 711   Writer.AddDeclRef(D->getNominatedNamespace(), Record);
 712   Writer.AddDeclRef(dyn_cast<Decl>(D->getCommonAncestor()), Record);
 713   Code = serialization::DECL_USING_DIRECTIVE;
 714 }
 715
 716 void ASTDeclWriter::VisitUnresolvedUsingValueDecl(UnresolvedUsingValueDecl *D) {
 717   VisitValueDecl(D);
 718   Writer.AddSourceRange(D->getTargetNestedNameRange(), Record);
 719   Writer.AddSourceLocation(D->getUsingLoc(), Record);
 720   Writer.AddNestedNameSpecifier(D->getTargetNestedNameSpecifier(), Record);
 721   Writer.AddDeclarationNameLoc(D->DNLoc, D->getDeclName(), Record);
 722   Code = serialization::DECL_UNRESOLVED_USING_VALUE;
 723 }
 724
 725 void ASTDeclWriter::VisitUnresolvedUsingTypenameDecl(
 726                                                UnresolvedUsingTypenameDecl *D) {
 727   VisitTypeDecl(D);
 728   Writer.AddSourceRange(D->getTargetNestedNameRange(), Record);
 729   Writer.AddSourceLocation(D->getUsingLoc(), Record);
 730   Writer.AddSourceLocation(D->getTypenameLoc(), Record);
 731   Writer.AddNestedNameSpecifier(D->getTargetNestedNameSpecifier(), Record);
 732   Code = serialization::DECL_UNRESOLVED_USING_TYPENAME;
 733 }
 734
 735 void ASTDeclWriter::VisitCXXRecordDecl(CXXRecordDecl *D) {
 736   VisitRecordDecl(D);
 737
 738   CXXRecordDecl *DefinitionDecl = 0;
 739   if (D->DefinitionData)
 740     DefinitionDecl = D->DefinitionData->Definition;
 741   Writer.AddDeclRef(DefinitionDecl, Record);
 742   if (D == DefinitionDecl)
 743     Writer.AddCXXDefinitionData(D, Record);
 744
 745   enum {
 746     CXXRecNotTemplate = 0, CXXRecTemplate, CXXRecMemberSpecialization
 747   };
 748   if (ClassTemplateDecl *TemplD = D->getDescribedClassTemplate()) {
 749     Record.push_back(CXXRecTemplate);
 750     Writer.AddDeclRef(TemplD, Record);
 751   } else if (MemberSpecializationInfo *MSInfo
 752                = D->getMemberSpecializationInfo()) {
 753     Record.push_back(CXXRecMemberSpecialization);
 754     Writer.AddDeclRef(MSInfo->getInstantiatedFrom(), Record);
 755     Record.push_back(MSInfo->getTemplateSpecializationKind());
 756     Writer.AddSourceLocation(MSInfo->getPointOfInstantiation(), Record);
 757   } else {
 758     Record.push_back(CXXRecNotTemplate);
 759   }
 760
 761   // Store the key function to avoid deserializing every method so we can
 762   // compute it.
 763   if (D->IsDefinition)
 764     Writer.AddDeclRef(Context.getKeyFunction(D), Record);
 765
 766   Code = serialization::DECL_CXX_RECORD;
 767 }
 768
 769 void ASTDeclWriter::VisitCXXMethodDecl(CXXMethodDecl *D) {
 770   VisitFunctionDecl(D);
 771   Record.push_back(D->size_overridden_methods());
 772   for (CXXMethodDecl::method_iterator
 773          I = D->begin_overridden_methods(), E = D->end_overridden_methods();
 774          I != E; ++I)
 775     Writer.AddDeclRef(*I, Record);
 776   Code = serialization::DECL_CXX_METHOD;
 777 }
 778
 779 void ASTDeclWriter::VisitCXXConstructorDecl(CXXConstructorDecl *D) {
 780   VisitCXXMethodDecl(D);
 781
 782   Record.push_back(D->IsExplicitSpecified);
 783   Record.push_back(D->ImplicitlyDefined);
 784   Writer.AddCXXBaseOrMemberInitializers(D->BaseOrMemberInitializers,
 785                                         D->NumBaseOrMemberInitializers, Record);
 786
 787   Code = serialization::DECL_CXX_CONSTRUCTOR;
 788 }
 789
 790 void ASTDeclWriter::VisitCXXDestructorDecl(CXXDestructorDecl *D) {
 791   VisitCXXMethodDecl(D);
 792
 793   Record.push_back(D->ImplicitlyDefined);
 794   Writer.AddDeclRef(D->OperatorDelete, Record);
 795
 796   Code = serialization::DECL_CXX_DESTRUCTOR;
 797 }
 798
 799 void ASTDeclWriter::VisitCXXConversionDecl(CXXConversionDecl *D) {
 800   VisitCXXMethodDecl(D);
 801   Record.push_back(D->IsExplicitSpecified);
 802   Code = serialization::DECL_CXX_CONVERSION;
 803 }
 804
 805 void ASTDeclWriter::VisitAccessSpecDecl(AccessSpecDecl *D) {
 806   VisitDecl(D);
 807   Writer.AddSourceLocation(D->getColonLoc(), Record);
 808   Code = serialization::DECL_ACCESS_SPEC;
 809 }
 810
 811 void ASTDeclWriter::VisitFriendDecl(FriendDecl *D) {
 812   VisitDecl(D);
 813   Record.push_back(D->Friend.is<TypeSourceInfo*>());
 814   if (D->Friend.is<TypeSourceInfo*>())
 815     Writer.AddTypeSourceInfo(D->Friend.get<TypeSourceInfo*>(), Record);
 816   else
 817     Writer.AddDeclRef(D->Friend.get<NamedDecl*>(), Record);
 818   Writer.AddDeclRef(D->getNextFriend(), Record);
 819   Record.push_back(D->UnsupportedFriend);
 820   Writer.AddSourceLocation(D->FriendLoc, Record);
 821   Code = serialization::DECL_FRIEND;
 822 }
 823
 824 void ASTDeclWriter::VisitFriendTemplateDecl(FriendTemplateDecl *D) {
 825   VisitDecl(D);
 826   Record.push_back(D->getNumTemplateParameters());
 827   for (unsigned i = 0, e = D->getNumTemplateParameters(); i != e; ++i)
 828     Writer.AddTemplateParameterList(D->getTemplateParameterList(i), Record);
 829   Record.push_back(D->getFriendDecl() != 0);
 830   if (D->getFriendDecl())
 831     Writer.AddDeclRef(D->getFriendDecl(), Record);
 832   else
 833     Writer.AddTypeSourceInfo(D->getFriendType(), Record);
 834   Writer.AddSourceLocation(D->getFriendLoc(), Record);
 835   Code = serialization::DECL_FRIEND_TEMPLATE;
 836 }
 837
 838 void ASTDeclWriter::VisitTemplateDecl(TemplateDecl *D) {
 839   VisitNamedDecl(D);
 840
 841   Writer.AddDeclRef(D->getTemplatedDecl(), Record);
 842   Writer.AddTemplateParameterList(D->getTemplateParameters(), Record);
 843 }
 844
 845 void ASTDeclWriter::VisitRedeclarableTemplateDecl(RedeclarableTemplateDecl *D) {
 846   // Emit data to initialize CommonOrPrev before VisitTemplateDecl so that
 847   // getCommonPtr() can be used while this is still initializing.
 848
 849   Writer.AddDeclRef(D->getPreviousDeclaration(), Record);
 850   if (D->getPreviousDeclaration() == 0) {
 851     // This TemplateDecl owns the CommonPtr; write it.
 852     assert(D->isCanonicalDecl());
 853
 854     Writer.AddDeclRef(D->getInstantiatedFromMemberTemplate(), Record);
 855     if (D->getInstantiatedFromMemberTemplate())
 856       Record.push_back(D->isMemberSpecialization());
 857
 858     Writer.AddDeclRef(D->getCommonPtr()->Latest, Record);
 859   } else {
 860     RedeclarableTemplateDecl *First = D->getFirstDeclaration();
 861     assert(First != D);
 862     // If this is a most recent redeclaration that is pointed to by a first decl
 863     // in a chained PCH, keep track of the association with the map so we can
 864     // update the first decl during AST reading.
 865     if (First->getMostRecentDeclaration() == D &&
 866         First->getPCHLevel() > D->getPCHLevel()) {
 867       assert(Writer.FirstLatestDecls.find(First)==Writer.FirstLatestDecls.end()
 868              && "The latest is already set");
 869       Writer.FirstLatestDecls[First] = D;
 870     }
 871   }
 872
 873   VisitTemplateDecl(D);
 874   Record.push_back(D->getIdentifierNamespace());
 875 }
 876
 877 void ASTDeclWriter::VisitClassTemplateDecl(ClassTemplateDecl *D) {
 878   VisitRedeclarableTemplateDecl(D);
 879
 880   if (D->getPreviousDeclaration() == 0) {
 881     typedef llvm::FoldingSet<ClassTemplateSpecializationDecl> CTSDSetTy;
 882     CTSDSetTy &CTSDSet = D->getSpecializations();
 883     Record.push_back(CTSDSet.size());
 884     for (CTSDSetTy::iterator I=CTSDSet.begin(), E = CTSDSet.end(); I!=E; ++I) {
 885       assert(I->isCanonicalDecl() && "Expected only canonical decls in set");
 886       Writer.AddDeclRef(&*I, Record);
 887     }
 888
 889     typedef llvm::FoldingSet<ClassTemplatePartialSpecializationDecl> CTPSDSetTy;
 890     CTPSDSetTy &CTPSDSet = D->getPartialSpecializations();
 891     Record.push_back(CTPSDSet.size());
 892     for (CTPSDSetTy::iterator I=CTPSDSet.begin(), E=CTPSDSet.end(); I!=E; ++I) {
 893       assert(I->isCanonicalDecl() && "Expected only canonical decls in set");
 894       Writer.AddDeclRef(&*I, Record);
 895     }
 896
 897     // InjectedClassNameType is computed, no need to write it.
 898   }
 899   Code = serialization::DECL_CLASS_TEMPLATE;
 900 }
 901
 902 void ASTDeclWriter::VisitClassTemplateSpecializationDecl(
 903                                            ClassTemplateSpecializationDecl *D) {
 904   VisitCXXRecordDecl(D);
 905
 906   llvm::PointerUnion<ClassTemplateDecl *,
 907                      ClassTemplatePartialSpecializationDecl *> InstFrom
 908     = D->getSpecializedTemplateOrPartial();
 909   Decl *InstFromD;
 910   if (InstFrom.is<ClassTemplateDecl *>()) {
 911     InstFromD = InstFrom.get<ClassTemplateDecl *>();
 912     Writer.AddDeclRef(InstFromD, Record);
 913   } else {
 914     InstFromD = InstFrom.get<ClassTemplatePartialSpecializationDecl *>();
 915     Writer.AddDeclRef(InstFromD, Record);
 916     Writer.AddTemplateArgumentList(&D->getTemplateInstantiationArgs(), Record);
 917     InstFromD = cast<ClassTemplatePartialSpecializationDecl>(InstFromD)->
 918                     getSpecializedTemplate();
 919   }
 920
 921   // Explicit info.
 922   Writer.AddTypeSourceInfo(D->getTypeAsWritten(), Record);
 923   if (D->getTypeAsWritten()) {
 924     Writer.AddSourceLocation(D->getExternLoc(), Record);
 925     Writer.AddSourceLocation(D->getTemplateKeywordLoc(), Record);
 926   }
 927
 928   Writer.AddTemplateArgumentList(&D->getTemplateArgs(), Record);
 929   Writer.AddSourceLocation(D->getPointOfInstantiation(), Record);
 930   Record.push_back(D->getSpecializationKind());
 931
 932   if (D->isCanonicalDecl()) {
 933     // When reading, we'll add it to the folding set of the following template.
 934     Writer.AddDeclRef(D->getSpecializedTemplate()->getCanonicalDecl(), Record);
 935   }
 936
 937   Code = serialization::DECL_CLASS_TEMPLATE_SPECIALIZATION;
 938 }
 939
 940 void ASTDeclWriter::VisitClassTemplatePartialSpecializationDecl(
 941                                     ClassTemplatePartialSpecializationDecl *D) {
 942   VisitClassTemplateSpecializationDecl(D);
 943
 944   Writer.AddTemplateParameterList(D->getTemplateParameters(), Record);
 945
 946   Record.push_back(D->getNumTemplateArgsAsWritten());
 947   for (int i = 0, e = D->getNumTemplateArgsAsWritten(); i != e; ++i)
 948     Writer.AddTemplateArgumentLoc(D->getTemplateArgsAsWritten()[i], Record);
 949
 950   Record.push_back(D->getSequenceNumber());
 951
 952   // These are read/set from/to the first declaration.
 953   if (D->getPreviousDeclaration() == 0) {
 954     Writer.AddDeclRef(D->getInstantiatedFromMember(), Record);
 955     Record.push_back(D->isMemberSpecialization());
 956   }
 957
 958   Code = serialization::DECL_CLASS_TEMPLATE_PARTIAL_SPECIALIZATION;
 959 }
 960
 961 void ASTDeclWriter::VisitFunctionTemplateDecl(FunctionTemplateDecl *D) {
 962   VisitRedeclarableTemplateDecl(D);
 963
 964   if (D->getPreviousDeclaration() == 0) {
 965     // This FunctionTemplateDecl owns the CommonPtr; write it.
 966
 967     // Write the function specialization declarations.
 968     Record.push_back(D->getSpecializations().size());
 969     for (llvm::FoldingSet<FunctionTemplateSpecializationInfo>::iterator
 970            I = D->getSpecializations().begin(),
 971            E = D->getSpecializations().end()   ; I != E; ++I) {
 972       assert(I->Function->isCanonicalDecl() &&
 973              "Expected only canonical decls in set");
 974       Writer.AddDeclRef(I->Function, Record);
 975     }
 976   }
 977   Code = serialization::DECL_FUNCTION_TEMPLATE;
 978 }
 979
 980 void ASTDeclWriter::VisitTemplateTypeParmDecl(TemplateTypeParmDecl *D) {
 981   VisitTypeDecl(D);
 982
 983   Record.push_back(D->wasDeclaredWithTypename());
 984   Record.push_back(D->isParameterPack());
 985   Record.push_back(D->defaultArgumentWasInherited());
 986   Writer.AddTypeSourceInfo(D->getDefaultArgumentInfo(), Record);
 987
 988   Code = serialization::DECL_TEMPLATE_TYPE_PARM;
 989 }
 990
 991 void ASTDeclWriter::VisitNonTypeTemplateParmDecl(NonTypeTemplateParmDecl *D) {
 992   VisitVarDecl(D);
 993   // TemplateParmPosition.
 994   Record.push_back(D->getDepth());
 995   Record.push_back(D->getPosition());
 996   // Rest of NonTypeTemplateParmDecl.
 997   Record.push_back(D->getDefaultArgument() != 0);
 998   if (D->getDefaultArgument()) {
 999     Writer.AddStmt(D->getDefaultArgument());
1000     Record.push_back(D->defaultArgumentWasInherited());
1001   }
1002   Code = serialization::DECL_NON_TYPE_TEMPLATE_PARM;
1003 }
1004
1005 void ASTDeclWriter::VisitTemplateTemplateParmDecl(TemplateTemplateParmDecl *D) {
1006   VisitTemplateDecl(D);
1007   // TemplateParmPosition.
1008   Record.push_back(D->getDepth());
1009   Record.push_back(D->getPosition());
1010   // Rest of TemplateTemplateParmDecl.
1011   Writer.AddTemplateArgumentLoc(D->getDefaultArgument(), Record);
1012   Record.push_back(D->defaultArgumentWasInherited());
1013   Code = serialization::DECL_TEMPLATE_TEMPLATE_PARM;
1014 }
1015
1016 void ASTDeclWriter::VisitStaticAssertDecl(StaticAssertDecl *D) {
1017   VisitDecl(D);
1018   Writer.AddStmt(D->getAssertExpr());
1019   Writer.AddStmt(D->getMessage());
1020   Code = serialization::DECL_STATIC_ASSERT;
1021 }
1022
1023 /// \brief Emit the DeclContext part of a declaration context decl.
1024 ///
1025 /// \param LexicalOffset the offset at which the DECL_CONTEXT_LEXICAL
1026 /// block for this declaration context is stored. May be 0 to indicate
1027 /// that there are no declarations stored within this context.
1028 ///
1029 /// \param VisibleOffset the offset at which the DECL_CONTEXT_VISIBLE
1030 /// block for this declaration context is stored. May be 0 to indicate
1031 /// that there are no declarations visible from this context. Note
1032 /// that this value will not be emitted for non-primary declaration
1033 /// contexts.
1034 void ASTDeclWriter::VisitDeclContext(DeclContext *DC, uint64_t LexicalOffset,
1035                                      uint64_t VisibleOffset) {
1036   Record.push_back(LexicalOffset);
1037   Record.push_back(VisibleOffset);
1038 }
1039
1040 template <typename T>
1041 void ASTDeclWriter::VisitRedeclarable(Redeclarable<T> *D) {
1042   enum { NoRedeclaration = 0, PointsToPrevious, PointsToLatest };
1043   if (D->RedeclLink.getNext() == D) {
1044     Record.push_back(NoRedeclaration);
1045   } else {
1046     Record.push_back(D->RedeclLink.NextIsPrevious() ? PointsToPrevious
1047                                                     : PointsToLatest);
1048     Writer.AddDeclRef(D->RedeclLink.getPointer(), Record);
1049   }
1050
1051   T *First = D->getFirstDeclaration();
1052   T *ThisDecl = static_cast<T*>(D);
1053   // If this is a most recent redeclaration that is pointed to by a first decl
1054   // in a chained PCH, keep track of the association with the map so we can
1055   // update the first decl during AST reading.
1056   if (ThisDecl != First && First->getMostRecentDeclaration() == ThisDecl &&
1057       First->getPCHLevel() > ThisDecl->getPCHLevel()) {
1058     assert(Writer.FirstLatestDecls.find(First) == Writer.FirstLatestDecls.end()
1059            && "The latest is already set");
1060     Writer.FirstLatestDecls[First] = ThisDecl;
1061   }
1062 }
1063
1064 //===----------------------------------------------------------------------===//
1065 // ASTWriter Implementation
1066 //===----------------------------------------------------------------------===//
1067
1068 void ASTWriter::WriteDeclsBlockAbbrevs() {
1069   using namespace llvm;
1070   // Abbreviation for DECL_PARM_VAR.
1071   BitCodeAbbrev *Abv = new BitCodeAbbrev();
1072   Abv->Add(BitCodeAbbrevOp(serialization::DECL_PARM_VAR));
1073
1074   // Decl
1075   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclContext
1076   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LexicalDeclContext
1077   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Location
1078   Abv->Add(BitCodeAbbrevOp(0));                       // isInvalidDecl (!?)
1079   Abv->Add(BitCodeAbbrevOp(0));                       // HasAttrs
1080   Abv->Add(BitCodeAbbrevOp(0));                       // isImplicit
1081   Abv->Add(BitCodeAbbrevOp(0));                       // isUsed
1082   Abv->Add(BitCodeAbbrevOp(AS_none));                 // C++ AccessSpecifier
1083   Abv->Add(BitCodeAbbrevOp(0));                       // PCH level
1084
1085   // NamedDecl
1086   Abv->Add(BitCodeAbbrevOp(0));                       // NameKind = Identifier
1087   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Name
1088   // ValueDecl
1089   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
1090   // DeclaratorDecl
1091   Abv->Add(BitCodeAbbrevOp(0));                       // hasExtInfo
1092   Abv->Add(BitCodeAbbrevOp(serialization::PREDEF_TYPE_NULL_ID)); // InfoType
1093   // VarDecl
1094   Abv->Add(BitCodeAbbrevOp(0));                       // No redeclaration
1095   Abv->Add(BitCodeAbbrevOp(0));                       // StorageClass
1096   Abv->Add(BitCodeAbbrevOp(0));                       // StorageClassAsWritten
1097   Abv->Add(BitCodeAbbrevOp(0));                       // isThreadSpecified
1098   Abv->Add(BitCodeAbbrevOp(0));                       // hasCXXDirectInitializer
1099   Abv->Add(BitCodeAbbrevOp(0));                       // isExceptionVariable
1100   Abv->Add(BitCodeAbbrevOp(0));                       // isNRVOVariable
1101   Abv->Add(BitCodeAbbrevOp(0));                       // HasInit
1102   Abv->Add(BitCodeAbbrevOp(0));                   // HasMemberSpecializationInfo
1103   // ParmVarDecl
1104   Abv->Add(BitCodeAbbrevOp(0));                       // ObjCDeclQualifier
1105   Abv->Add(BitCodeAbbrevOp(0));                       // HasInheritedDefaultArg
1106   Abv->Add(BitCodeAbbrevOp(0));                   // HasUninstantiatedDefaultArg
1107
1108   ParmVarDeclAbbrev = Stream.EmitAbbrev(Abv);
1109
1110   Abv = new BitCodeAbbrev();
1111   Abv->Add(BitCodeAbbrevOp(serialization::DECL_CONTEXT_LEXICAL));
1112   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
1113   DeclContextLexicalAbbrev = Stream.EmitAbbrev(Abv);
1114
1115   Abv = new BitCodeAbbrev();
1116   Abv->Add(BitCodeAbbrevOp(serialization::DECL_CONTEXT_VISIBLE));
1117   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
1118   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
1119   DeclContextVisibleLookupAbbrev = Stream.EmitAbbrev(Abv);
1120 }
1121
1122 /// isRequiredDecl - Check if this is a "required" Decl, which must be seen by
1123 /// consumers of the AST.
1124 ///
1125 /// Such decls will always be deserialized from the AST file, so we would like
1126 /// this to be as restrictive as possible. Currently the predicate is driven by
1127 /// code generation requirements, if other clients have a different notion of
1128 /// what is "required" then we may have to consider an alternate scheme where
1129 /// clients can iterate over the top-level decls and get information on them,
1130 /// without necessary deserializing them. We could explicitly require such
1131 /// clients to use a separate API call to "realize" the decl. This should be
1132 /// relatively painless since they would presumably only do it for top-level
1133 /// decls.
1134 static bool isRequiredDecl(const Decl *D, ASTContext &Context) {
1135   // File scoped assembly or obj-c implementation must be seen.
1136   if (isa<FileScopeAsmDecl>(D) || isa<ObjCImplementationDecl>(D))
1137     return true;
1138
1139   return Context.DeclMustBeEmitted(D);
1140 }
1141
1142 void ASTWriter::WriteDecl(ASTContext &Context, Decl *D) {
1143   // Switch case IDs are per Decl.
1144   ClearSwitchCaseIDs();
1145
1146   RecordData Record;
1147   ASTDeclWriter W(*this, Context, Record);
1148
1149   // If this declaration is also a DeclContext, write blocks for the
1150   // declarations that lexically stored inside its context and those
1151   // declarations that are visible from its context. These blocks
1152   // are written before the declaration itself so that we can put
1153   // their offsets into the record for the declaration.
1154   uint64_t LexicalOffset = 0;
1155   uint64_t VisibleOffset = 0;
1156   DeclContext *DC = dyn_cast<DeclContext>(D);
1157   if (DC) {
1158     LexicalOffset = WriteDeclContextLexicalBlock(Context, DC);
1159     VisibleOffset = WriteDeclContextVisibleBlock(Context, DC);
1160   }
1161
1162   // Determine the ID for this declaration
1163   serialization::DeclID &IDR = DeclIDs[D];
1164   if (IDR == 0)
1165     IDR = NextDeclID++;
1166   serialization::DeclID ID = IDR;
1167
1168   if (ID < FirstDeclID) {
1169     // We're replacing a decl in a previous file.
1170     ReplacedDecls.push_back(std::make_pair(ID, Stream.GetCurrentBitNo()));
1171   } else {
1172     unsigned Index = ID - FirstDeclID;
1173
1174     // Record the offset for this declaration
1175     if (DeclOffsets.size() == Index)
1176       DeclOffsets.push_back(Stream.GetCurrentBitNo());
1177     else if (DeclOffsets.size() < Index) {
1178       DeclOffsets.resize(Index+1);
1179       DeclOffsets[Index] = Stream.GetCurrentBitNo();
1180     }
1181   }
1182
1183   // Build and emit a record for this declaration
1184   Record.clear();
1185   W.Code = (serialization::DeclCode)0;
1186   W.AbbrevToUse = 0;
1187   W.Visit(D);
1188   if (DC) W.VisitDeclContext(DC, LexicalOffset, VisibleOffset);
1189
1190   if (!W.Code)
1191     llvm::report_fatal_error(llvm::StringRef("unexpected declaration kind '") +
1192                             D->getDeclKindName() + "'");
1193   Stream.EmitRecord(W.Code, Record, W.AbbrevToUse);
1194
1195   // Flush any expressions that were written as part of this declaration.
1196   FlushStmts();
1197
1198   // Flush C++ base specifiers, if there are any.
1199   FlushCXXBaseSpecifiers();
1200
1201   // Note "external" declarations so that we can add them to a record in the
1202   // AST file later.
1203   //
1204   // FIXME: This should be renamed, the predicate is much more complicated.
1205   if (isRequiredDecl(D, Context))
1206     ExternalDefinitions.push_back(ID);
1207 }