1 //===--- ASTWriter.cpp - AST File Writer ----------------------------------===//
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 defines the ASTWriter class, which writes AST files.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "clang/Serialization/ASTWriter.h"
15 #include "ASTCommon.h"
16 #include "clang/Sema/Sema.h"
17 #include "clang/Sema/IdentifierResolver.h"
18 #include "clang/AST/ASTContext.h"
19 #include "clang/AST/Decl.h"
20 #include "clang/AST/DeclContextInternals.h"
21 #include "clang/AST/DeclTemplate.h"
22 #include "clang/AST/DeclFriend.h"
23 #include "clang/AST/Expr.h"
24 #include "clang/AST/ExprCXX.h"
25 #include "clang/AST/Type.h"
26 #include "clang/AST/TypeLocVisitor.h"
27 #include "clang/Serialization/ASTReader.h"
28 #include "clang/Lex/MacroInfo.h"
29 #include "clang/Lex/PreprocessingRecord.h"
30 #include "clang/Lex/Preprocessor.h"
31 #include "clang/Lex/HeaderSearch.h"
32 #include "clang/Basic/FileManager.h"
33 #include "clang/Basic/FileSystemStatCache.h"
34 #include "clang/Basic/OnDiskHashTable.h"
35 #include "clang/Basic/SourceManager.h"
36 #include "clang/Basic/SourceManagerInternals.h"
37 #include "clang/Basic/TargetInfo.h"
38 #include "clang/Basic/Version.h"
39 #include "clang/Basic/VersionTuple.h"
40 #include "llvm/ADT/APFloat.h"
41 #include "llvm/ADT/APInt.h"
42 #include "llvm/ADT/StringExtras.h"
43 #include "llvm/Bitcode/BitstreamWriter.h"
44 #include "llvm/Support/FileSystem.h"
45 #include "llvm/Support/MemoryBuffer.h"
46 #include "llvm/Support/Path.h"
47 #include <algorithm>
48 #include <cstdio>
49 #include <string.h>
50 #include <utility>
51 using namespace clang;
52 using namespace clang::serialization;
53 
54 template <typename T, typename Allocator>
55 static StringRef data(const std::vector<T, Allocator> &v) {
56   if (v.empty()) return StringRef();
57   return StringRef(reinterpret_cast<const char*>(&v[0]),
58                          sizeof(T) * v.size());
59 }
60 
61 template <typename T>
62 static StringRef data(const SmallVectorImpl<T> &v) {
63   return StringRef(reinterpret_cast<const char*>(v.data()),
64                          sizeof(T) * v.size());
65 }
66 
67 //===----------------------------------------------------------------------===//
68 // Type serialization
69 //===----------------------------------------------------------------------===//
70 
71 namespace {
72   class ASTTypeWriter {
73     ASTWriter &Writer;
74     ASTWriter::RecordDataImpl &Record;
75 
76   public:
77     /// \brief Type code that corresponds to the record generated.
78     TypeCode Code;
79 
80     ASTTypeWriter(ASTWriter &Writer, ASTWriter::RecordDataImpl &Record)
81       : Writer(Writer), Record(Record), Code(TYPE_EXT_QUAL) { }
82 
83     void VisitArrayType(const ArrayType *T);
84     void VisitFunctionType(const FunctionType *T);
85     void VisitTagType(const TagType *T);
86 
87 #define TYPE(Class, Base) void Visit##Class##Type(const Class##Type *T);
88 #define ABSTRACT_TYPE(Class, Base)
89 #include "clang/AST/TypeNodes.def"
90   };
91 }
92 
93 void ASTTypeWriter::VisitBuiltinType(const BuiltinType *T) {
94   llvm_unreachable("Built-in types are never serialized");
95 }
96 
97 void ASTTypeWriter::VisitComplexType(const ComplexType *T) {
98   Writer.AddTypeRef(T->getElementType(), Record);
99   Code = TYPE_COMPLEX;
100 }
101 
102 void ASTTypeWriter::VisitPointerType(const PointerType *T) {
103   Writer.AddTypeRef(T->getPointeeType(), Record);
104   Code = TYPE_POINTER;
105 }
106 
107 void ASTTypeWriter::VisitBlockPointerType(const BlockPointerType *T) {
108   Writer.AddTypeRef(T->getPointeeType(), Record);
109   Code = TYPE_BLOCK_POINTER;
110 }
111 
112 void ASTTypeWriter::VisitLValueReferenceType(const LValueReferenceType *T) {
113   Writer.AddTypeRef(T->getPointeeTypeAsWritten(), Record);
114   Record.push_back(T->isSpelledAsLValue());
115   Code = TYPE_LVALUE_REFERENCE;
116 }
117 
118 void ASTTypeWriter::VisitRValueReferenceType(const RValueReferenceType *T) {
119   Writer.AddTypeRef(T->getPointeeTypeAsWritten(), Record);
120   Code = TYPE_RVALUE_REFERENCE;
121 }
122 
123 void ASTTypeWriter::VisitMemberPointerType(const MemberPointerType *T) {
124   Writer.AddTypeRef(T->getPointeeType(), Record);
125   Writer.AddTypeRef(QualType(T->getClass(), 0), Record);
126   Code = TYPE_MEMBER_POINTER;
127 }
128 
129 void ASTTypeWriter::VisitArrayType(const ArrayType *T) {
130   Writer.AddTypeRef(T->getElementType(), Record);
131   Record.push_back(T->getSizeModifier()); // FIXME: stable values
132   Record.push_back(T->getIndexTypeCVRQualifiers()); // FIXME: stable values
133 }
134 
135 void ASTTypeWriter::VisitConstantArrayType(const ConstantArrayType *T) {
136   VisitArrayType(T);
137   Writer.AddAPInt(T->getSize(), Record);
138   Code = TYPE_CONSTANT_ARRAY;
139 }
140 
141 void ASTTypeWriter::VisitIncompleteArrayType(const IncompleteArrayType *T) {
142   VisitArrayType(T);
143   Code = TYPE_INCOMPLETE_ARRAY;
144 }
145 
146 void ASTTypeWriter::VisitVariableArrayType(const VariableArrayType *T) {
147   VisitArrayType(T);
148   Writer.AddSourceLocation(T->getLBracketLoc(), Record);
149   Writer.AddSourceLocation(T->getRBracketLoc(), Record);
150   Writer.AddStmt(T->getSizeExpr());
151   Code = TYPE_VARIABLE_ARRAY;
152 }
153 
154 void ASTTypeWriter::VisitVectorType(const VectorType *T) {
155   Writer.AddTypeRef(T->getElementType(), Record);
156   Record.push_back(T->getNumElements());
157   Record.push_back(T->getVectorKind());
158   Code = TYPE_VECTOR;
159 }
160 
161 void ASTTypeWriter::VisitExtVectorType(const ExtVectorType *T) {
162   VisitVectorType(T);
163   Code = TYPE_EXT_VECTOR;
164 }
165 
166 void ASTTypeWriter::VisitFunctionType(const FunctionType *T) {
167   Writer.AddTypeRef(T->getResultType(), Record);
168   FunctionType::ExtInfo C = T->getExtInfo();
169   Record.push_back(C.getNoReturn());
170   Record.push_back(C.getHasRegParm());
171   Record.push_back(C.getRegParm());
172   // FIXME: need to stabilize encoding of calling convention...
173   Record.push_back(C.getCC());
174   Record.push_back(C.getProducesResult());
175 }
176 
177 void ASTTypeWriter::VisitFunctionNoProtoType(const FunctionNoProtoType *T) {
178   VisitFunctionType(T);
179   Code = TYPE_FUNCTION_NO_PROTO;
180 }
181 
182 void ASTTypeWriter::VisitFunctionProtoType(const FunctionProtoType *T) {
183   VisitFunctionType(T);
184   Record.push_back(T->getNumArgs());
185   for (unsigned I = 0, N = T->getNumArgs(); I != N; ++I)
186     Writer.AddTypeRef(T->getArgType(I), Record);
187   Record.push_back(T->isVariadic());
188   Record.push_back(T->getTypeQuals());
189   Record.push_back(static_cast<unsigned>(T->getRefQualifier()));
190   Record.push_back(T->getExceptionSpecType());
191   if (T->getExceptionSpecType() == EST_Dynamic) {
192     Record.push_back(T->getNumExceptions());
193     for (unsigned I = 0, N = T->getNumExceptions(); I != N; ++I)
194       Writer.AddTypeRef(T->getExceptionType(I), Record);
195   } else if (T->getExceptionSpecType() == EST_ComputedNoexcept) {
196     Writer.AddStmt(T->getNoexceptExpr());
197   }
198   Code = TYPE_FUNCTION_PROTO;
199 }
200 
201 void ASTTypeWriter::VisitUnresolvedUsingType(const UnresolvedUsingType *T) {
202   Writer.AddDeclRef(T->getDecl(), Record);
203   Code = TYPE_UNRESOLVED_USING;
204 }
205 
206 void ASTTypeWriter::VisitTypedefType(const TypedefType *T) {
207   Writer.AddDeclRef(T->getDecl(), Record);
208   assert(!T->isCanonicalUnqualified() && "Invalid typedef ?");
209   Writer.AddTypeRef(T->getCanonicalTypeInternal(), Record);
210   Code = TYPE_TYPEDEF;
211 }
212 
213 void ASTTypeWriter::VisitTypeOfExprType(const TypeOfExprType *T) {
214   Writer.AddStmt(T->getUnderlyingExpr());
215   Code = TYPE_TYPEOF_EXPR;
216 }
217 
218 void ASTTypeWriter::VisitTypeOfType(const TypeOfType *T) {
219   Writer.AddTypeRef(T->getUnderlyingType(), Record);
220   Code = TYPE_TYPEOF;
221 }
222 
223 void ASTTypeWriter::VisitDecltypeType(const DecltypeType *T) {
224   Writer.AddStmt(T->getUnderlyingExpr());
225   Code = TYPE_DECLTYPE;
226 }
227 
228 void ASTTypeWriter::VisitUnaryTransformType(const UnaryTransformType *T) {
229   Writer.AddTypeRef(T->getBaseType(), Record);
230   Writer.AddTypeRef(T->getUnderlyingType(), Record);
231   Record.push_back(T->getUTTKind());
232   Code = TYPE_UNARY_TRANSFORM;
233 }
234 
235 void ASTTypeWriter::VisitAutoType(const AutoType *T) {
236   Writer.AddTypeRef(T->getDeducedType(), Record);
237   Code = TYPE_AUTO;
238 }
239 
240 void ASTTypeWriter::VisitTagType(const TagType *T) {
241   Record.push_back(T->isDependentType());
242   Writer.AddDeclRef(T->getDecl(), Record);
243   assert(!T->isBeingDefined() &&
244          "Cannot serialize in the middle of a type definition");
245 }
246 
247 void ASTTypeWriter::VisitRecordType(const RecordType *T) {
248   VisitTagType(T);
249   Code = TYPE_RECORD;
250 }
251 
252 void ASTTypeWriter::VisitEnumType(const EnumType *T) {
253   VisitTagType(T);
254   Code = TYPE_ENUM;
255 }
256 
257 void ASTTypeWriter::VisitAttributedType(const AttributedType *T) {
258   Writer.AddTypeRef(T->getModifiedType(), Record);
259   Writer.AddTypeRef(T->getEquivalentType(), Record);
260   Record.push_back(T->getAttrKind());
261   Code = TYPE_ATTRIBUTED;
262 }
263 
264 void
265 ASTTypeWriter::VisitSubstTemplateTypeParmType(
266                                         const SubstTemplateTypeParmType *T) {
267   Writer.AddTypeRef(QualType(T->getReplacedParameter(), 0), Record);
268   Writer.AddTypeRef(T->getReplacementType(), Record);
269   Code = TYPE_SUBST_TEMPLATE_TYPE_PARM;
270 }
271 
272 void
273 ASTTypeWriter::VisitSubstTemplateTypeParmPackType(
274                                       const SubstTemplateTypeParmPackType *T) {
275   Writer.AddTypeRef(QualType(T->getReplacedParameter(), 0), Record);
276   Writer.AddTemplateArgument(T->getArgumentPack(), Record);
277   Code = TYPE_SUBST_TEMPLATE_TYPE_PARM_PACK;
278 }
279 
280 void
281 ASTTypeWriter::VisitTemplateSpecializationType(
282                                        const TemplateSpecializationType *T) {
283   Record.push_back(T->isDependentType());
284   Writer.AddTemplateName(T->getTemplateName(), Record);
285   Record.push_back(T->getNumArgs());
286   for (TemplateSpecializationType::iterator ArgI = T->begin(), ArgE = T->end();
287          ArgI != ArgE; ++ArgI)
288     Writer.AddTemplateArgument(*ArgI, Record);
289   Writer.AddTypeRef(T->isTypeAlias() ? T->getAliasedType() :
290                     T->isCanonicalUnqualified() ? QualType()
291                                                 : T->getCanonicalTypeInternal(),
292                     Record);
293   Code = TYPE_TEMPLATE_SPECIALIZATION;
294 }
295 
296 void
297 ASTTypeWriter::VisitDependentSizedArrayType(const DependentSizedArrayType *T) {
298   VisitArrayType(T);
299   Writer.AddStmt(T->getSizeExpr());
300   Writer.AddSourceRange(T->getBracketsRange(), Record);
301   Code = TYPE_DEPENDENT_SIZED_ARRAY;
302 }
303 
304 void
305 ASTTypeWriter::VisitDependentSizedExtVectorType(
306                                         const DependentSizedExtVectorType *T) {
307   // FIXME: Serialize this type (C++ only)
308   llvm_unreachable("Cannot serialize dependent sized extended vector types");
309 }
310 
311 void
312 ASTTypeWriter::VisitTemplateTypeParmType(const TemplateTypeParmType *T) {
313   Record.push_back(T->getDepth());
314   Record.push_back(T->getIndex());
315   Record.push_back(T->isParameterPack());
316   Writer.AddDeclRef(T->getDecl(), Record);
317   Code = TYPE_TEMPLATE_TYPE_PARM;
318 }
319 
320 void
321 ASTTypeWriter::VisitDependentNameType(const DependentNameType *T) {
322   Record.push_back(T->getKeyword());
323   Writer.AddNestedNameSpecifier(T->getQualifier(), Record);
324   Writer.AddIdentifierRef(T->getIdentifier(), Record);
325   Writer.AddTypeRef(T->isCanonicalUnqualified() ? QualType()
326                                                 : T->getCanonicalTypeInternal(),
327                     Record);
328   Code = TYPE_DEPENDENT_NAME;
329 }
330 
331 void
332 ASTTypeWriter::VisitDependentTemplateSpecializationType(
333                                 const DependentTemplateSpecializationType *T) {
334   Record.push_back(T->getKeyword());
335   Writer.AddNestedNameSpecifier(T->getQualifier(), Record);
336   Writer.AddIdentifierRef(T->getIdentifier(), Record);
337   Record.push_back(T->getNumArgs());
338   for (DependentTemplateSpecializationType::iterator
339          I = T->begin(), E = T->end(); I != E; ++I)
340     Writer.AddTemplateArgument(*I, Record);
341   Code = TYPE_DEPENDENT_TEMPLATE_SPECIALIZATION;
342 }
343 
344 void ASTTypeWriter::VisitPackExpansionType(const PackExpansionType *T) {
345   Writer.AddTypeRef(T->getPattern(), Record);
346   if (llvm::Optional<unsigned> NumExpansions = T->getNumExpansions())
347     Record.push_back(*NumExpansions + 1);
348   else
349     Record.push_back(0);
350   Code = TYPE_PACK_EXPANSION;
351 }
352 
353 void ASTTypeWriter::VisitParenType(const ParenType *T) {
354   Writer.AddTypeRef(T->getInnerType(), Record);
355   Code = TYPE_PAREN;
356 }
357 
358 void ASTTypeWriter::VisitElaboratedType(const ElaboratedType *T) {
359   Record.push_back(T->getKeyword());
360   Writer.AddNestedNameSpecifier(T->getQualifier(), Record);
361   Writer.AddTypeRef(T->getNamedType(), Record);
362   Code = TYPE_ELABORATED;
363 }
364 
365 void ASTTypeWriter::VisitInjectedClassNameType(const InjectedClassNameType *T) {
366   Writer.AddDeclRef(T->getDecl(), Record);
367   Writer.AddTypeRef(T->getInjectedSpecializationType(), Record);
368   Code = TYPE_INJECTED_CLASS_NAME;
369 }
370 
371 void ASTTypeWriter::VisitObjCInterfaceType(const ObjCInterfaceType *T) {
372   Writer.AddDeclRef(T->getDecl(), Record);
373   Code = TYPE_OBJC_INTERFACE;
374 }
375 
376 void ASTTypeWriter::VisitObjCObjectType(const ObjCObjectType *T) {
377   Writer.AddTypeRef(T->getBaseType(), Record);
378   Record.push_back(T->getNumProtocols());
379   for (ObjCObjectType::qual_iterator I = T->qual_begin(),
380        E = T->qual_end(); I != E; ++I)
381     Writer.AddDeclRef(*I, Record);
382   Code = TYPE_OBJC_OBJECT;
383 }
384 
385 void
386 ASTTypeWriter::VisitObjCObjectPointerType(const ObjCObjectPointerType *T) {
387   Writer.AddTypeRef(T->getPointeeType(), Record);
388   Code = TYPE_OBJC_OBJECT_POINTER;
389 }
390 
391 void
392 ASTTypeWriter::VisitAtomicType(const AtomicType *T) {
393   Writer.AddTypeRef(T->getValueType(), Record);
394   Code = TYPE_ATOMIC;
395 }
396 
397 namespace {
398 
399 class TypeLocWriter : public TypeLocVisitor<TypeLocWriter> {
400   ASTWriter &Writer;
401   ASTWriter::RecordDataImpl &Record;
402 
403 public:
404   TypeLocWriter(ASTWriter &Writer, ASTWriter::RecordDataImpl &Record)
405     : Writer(Writer), Record(Record) { }
406 
407 #define ABSTRACT_TYPELOC(CLASS, PARENT)
408 #define TYPELOC(CLASS, PARENT) \
409     void Visit##CLASS##TypeLoc(CLASS##TypeLoc TyLoc);
410 #include "clang/AST/TypeLocNodes.def"
411 
412   void VisitArrayTypeLoc(ArrayTypeLoc TyLoc);
413   void VisitFunctionTypeLoc(FunctionTypeLoc TyLoc);
414 };
415 
416 }
417 
418 void TypeLocWriter::VisitQualifiedTypeLoc(QualifiedTypeLoc TL) {
419   // nothing to do
420 }
421 void TypeLocWriter::VisitBuiltinTypeLoc(BuiltinTypeLoc TL) {
422   Writer.AddSourceLocation(TL.getBuiltinLoc(), Record);
423   if (TL.needsExtraLocalData()) {
424     Record.push_back(TL.getWrittenTypeSpec());
425     Record.push_back(TL.getWrittenSignSpec());
426     Record.push_back(TL.getWrittenWidthSpec());
427     Record.push_back(TL.hasModeAttr());
428   }
429 }
430 void TypeLocWriter::VisitComplexTypeLoc(ComplexTypeLoc TL) {
431   Writer.AddSourceLocation(TL.getNameLoc(), Record);
432 }
433 void TypeLocWriter::VisitPointerTypeLoc(PointerTypeLoc TL) {
434   Writer.AddSourceLocation(TL.getStarLoc(), Record);
435 }
436 void TypeLocWriter::VisitBlockPointerTypeLoc(BlockPointerTypeLoc TL) {
437   Writer.AddSourceLocation(TL.getCaretLoc(), Record);
438 }
439 void TypeLocWriter::VisitLValueReferenceTypeLoc(LValueReferenceTypeLoc TL) {
440   Writer.AddSourceLocation(TL.getAmpLoc(), Record);
441 }
442 void TypeLocWriter::VisitRValueReferenceTypeLoc(RValueReferenceTypeLoc TL) {
443   Writer.AddSourceLocation(TL.getAmpAmpLoc(), Record);
444 }
445 void TypeLocWriter::VisitMemberPointerTypeLoc(MemberPointerTypeLoc TL) {
446   Writer.AddSourceLocation(TL.getStarLoc(), Record);
447   Writer.AddTypeSourceInfo(TL.getClassTInfo(), Record);
448 }
449 void TypeLocWriter::VisitArrayTypeLoc(ArrayTypeLoc TL) {
450   Writer.AddSourceLocation(TL.getLBracketLoc(), Record);
451   Writer.AddSourceLocation(TL.getRBracketLoc(), Record);
452   Record.push_back(TL.getSizeExpr() ? 1 : 0);
453   if (TL.getSizeExpr())
454     Writer.AddStmt(TL.getSizeExpr());
455 }
456 void TypeLocWriter::VisitConstantArrayTypeLoc(ConstantArrayTypeLoc TL) {
457   VisitArrayTypeLoc(TL);
458 }
459 void TypeLocWriter::VisitIncompleteArrayTypeLoc(IncompleteArrayTypeLoc TL) {
460   VisitArrayTypeLoc(TL);
461 }
462 void TypeLocWriter::VisitVariableArrayTypeLoc(VariableArrayTypeLoc TL) {
463   VisitArrayTypeLoc(TL);
464 }
465 void TypeLocWriter::VisitDependentSizedArrayTypeLoc(
466                                             DependentSizedArrayTypeLoc TL) {
467   VisitArrayTypeLoc(TL);
468 }
469 void TypeLocWriter::VisitDependentSizedExtVectorTypeLoc(
470                                         DependentSizedExtVectorTypeLoc TL) {
471   Writer.AddSourceLocation(TL.getNameLoc(), Record);
472 }
473 void TypeLocWriter::VisitVectorTypeLoc(VectorTypeLoc TL) {
474   Writer.AddSourceLocation(TL.getNameLoc(), Record);
475 }
476 void TypeLocWriter::VisitExtVectorTypeLoc(ExtVectorTypeLoc TL) {
477   Writer.AddSourceLocation(TL.getNameLoc(), Record);
478 }
479 void TypeLocWriter::VisitFunctionTypeLoc(FunctionTypeLoc TL) {
480   Writer.AddSourceLocation(TL.getLocalRangeBegin(), Record);
481   Writer.AddSourceLocation(TL.getLocalRangeEnd(), Record);
482   Record.push_back(TL.getTrailingReturn());
483   for (unsigned i = 0, e = TL.getNumArgs(); i != e; ++i)
484     Writer.AddDeclRef(TL.getArg(i), Record);
485 }
486 void TypeLocWriter::VisitFunctionProtoTypeLoc(FunctionProtoTypeLoc TL) {
487   VisitFunctionTypeLoc(TL);
488 }
489 void TypeLocWriter::VisitFunctionNoProtoTypeLoc(FunctionNoProtoTypeLoc TL) {
490   VisitFunctionTypeLoc(TL);
491 }
492 void TypeLocWriter::VisitUnresolvedUsingTypeLoc(UnresolvedUsingTypeLoc TL) {
493   Writer.AddSourceLocation(TL.getNameLoc(), Record);
494 }
495 void TypeLocWriter::VisitTypedefTypeLoc(TypedefTypeLoc TL) {
496   Writer.AddSourceLocation(TL.getNameLoc(), Record);
497 }
498 void TypeLocWriter::VisitTypeOfExprTypeLoc(TypeOfExprTypeLoc TL) {
499   Writer.AddSourceLocation(TL.getTypeofLoc(), Record);
500   Writer.AddSourceLocation(TL.getLParenLoc(), Record);
501   Writer.AddSourceLocation(TL.getRParenLoc(), Record);
502 }
503 void TypeLocWriter::VisitTypeOfTypeLoc(TypeOfTypeLoc TL) {
504   Writer.AddSourceLocation(TL.getTypeofLoc(), Record);
505   Writer.AddSourceLocation(TL.getLParenLoc(), Record);
506   Writer.AddSourceLocation(TL.getRParenLoc(), Record);
507   Writer.AddTypeSourceInfo(TL.getUnderlyingTInfo(), Record);
508 }
509 void TypeLocWriter::VisitDecltypeTypeLoc(DecltypeTypeLoc TL) {
510   Writer.AddSourceLocation(TL.getNameLoc(), Record);
511 }
512 void TypeLocWriter::VisitUnaryTransformTypeLoc(UnaryTransformTypeLoc TL) {
513   Writer.AddSourceLocation(TL.getKWLoc(), Record);
514   Writer.AddSourceLocation(TL.getLParenLoc(), Record);
515   Writer.AddSourceLocation(TL.getRParenLoc(), Record);
516   Writer.AddTypeSourceInfo(TL.getUnderlyingTInfo(), Record);
517 }
518 void TypeLocWriter::VisitAutoTypeLoc(AutoTypeLoc TL) {
519   Writer.AddSourceLocation(TL.getNameLoc(), Record);
520 }
521 void TypeLocWriter::VisitRecordTypeLoc(RecordTypeLoc TL) {
522   Writer.AddSourceLocation(TL.getNameLoc(), Record);
523 }
524 void TypeLocWriter::VisitEnumTypeLoc(EnumTypeLoc TL) {
525   Writer.AddSourceLocation(TL.getNameLoc(), Record);
526 }
527 void TypeLocWriter::VisitAttributedTypeLoc(AttributedTypeLoc TL) {
528   Writer.AddSourceLocation(TL.getAttrNameLoc(), Record);
529   if (TL.hasAttrOperand()) {
530     SourceRange range = TL.getAttrOperandParensRange();
531     Writer.AddSourceLocation(range.getBegin(), Record);
532     Writer.AddSourceLocation(range.getEnd(), Record);
533   }
534   if (TL.hasAttrExprOperand()) {
535     Expr *operand = TL.getAttrExprOperand();
536     Record.push_back(operand ? 1 : 0);
537     if (operand) Writer.AddStmt(operand);
538   } else if (TL.hasAttrEnumOperand()) {
539     Writer.AddSourceLocation(TL.getAttrEnumOperandLoc(), Record);
540   }
541 }
542 void TypeLocWriter::VisitTemplateTypeParmTypeLoc(TemplateTypeParmTypeLoc TL) {
543   Writer.AddSourceLocation(TL.getNameLoc(), Record);
544 }
545 void TypeLocWriter::VisitSubstTemplateTypeParmTypeLoc(
546                                             SubstTemplateTypeParmTypeLoc TL) {
547   Writer.AddSourceLocation(TL.getNameLoc(), Record);
548 }
549 void TypeLocWriter::VisitSubstTemplateTypeParmPackTypeLoc(
550                                           SubstTemplateTypeParmPackTypeLoc TL) {
551   Writer.AddSourceLocation(TL.getNameLoc(), Record);
552 }
553 void TypeLocWriter::VisitTemplateSpecializationTypeLoc(
554                                            TemplateSpecializationTypeLoc TL) {
555   Writer.AddSourceLocation(TL.getTemplateNameLoc(), Record);
556   Writer.AddSourceLocation(TL.getLAngleLoc(), Record);
557   Writer.AddSourceLocation(TL.getRAngleLoc(), Record);
558   for (unsigned i = 0, e = TL.getNumArgs(); i != e; ++i)
559     Writer.AddTemplateArgumentLocInfo(TL.getArgLoc(i).getArgument().getKind(),
560                                       TL.getArgLoc(i).getLocInfo(), Record);
561 }
562 void TypeLocWriter::VisitParenTypeLoc(ParenTypeLoc TL) {
563   Writer.AddSourceLocation(TL.getLParenLoc(), Record);
564   Writer.AddSourceLocation(TL.getRParenLoc(), Record);
565 }
566 void TypeLocWriter::VisitElaboratedTypeLoc(ElaboratedTypeLoc TL) {
567   Writer.AddSourceLocation(TL.getKeywordLoc(), Record);
568   Writer.AddNestedNameSpecifierLoc(TL.getQualifierLoc(), Record);
569 }
570 void TypeLocWriter::VisitInjectedClassNameTypeLoc(InjectedClassNameTypeLoc TL) {
571   Writer.AddSourceLocation(TL.getNameLoc(), Record);
572 }
573 void TypeLocWriter::VisitDependentNameTypeLoc(DependentNameTypeLoc TL) {
574   Writer.AddSourceLocation(TL.getKeywordLoc(), Record);
575   Writer.AddNestedNameSpecifierLoc(TL.getQualifierLoc(), Record);
576   Writer.AddSourceLocation(TL.getNameLoc(), Record);
577 }
578 void TypeLocWriter::VisitDependentTemplateSpecializationTypeLoc(
579        DependentTemplateSpecializationTypeLoc TL) {
580   Writer.AddSourceLocation(TL.getKeywordLoc(), Record);
581   Writer.AddNestedNameSpecifierLoc(TL.getQualifierLoc(), Record);
582   Writer.AddSourceLocation(TL.getNameLoc(), Record);
583   Writer.AddSourceLocation(TL.getLAngleLoc(), Record);
584   Writer.AddSourceLocation(TL.getRAngleLoc(), Record);
585   for (unsigned I = 0, E = TL.getNumArgs(); I != E; ++I)
586     Writer.AddTemplateArgumentLocInfo(TL.getArgLoc(I).getArgument().getKind(),
587                                       TL.getArgLoc(I).getLocInfo(), Record);
588 }
589 void TypeLocWriter::VisitPackExpansionTypeLoc(PackExpansionTypeLoc TL) {
590   Writer.AddSourceLocation(TL.getEllipsisLoc(), Record);
591 }
592 void TypeLocWriter::VisitObjCInterfaceTypeLoc(ObjCInterfaceTypeLoc TL) {
593   Writer.AddSourceLocation(TL.getNameLoc(), Record);
594 }
595 void TypeLocWriter::VisitObjCObjectTypeLoc(ObjCObjectTypeLoc TL) {
596   Record.push_back(TL.hasBaseTypeAsWritten());
597   Writer.AddSourceLocation(TL.getLAngleLoc(), Record);
598   Writer.AddSourceLocation(TL.getRAngleLoc(), Record);
599   for (unsigned i = 0, e = TL.getNumProtocols(); i != e; ++i)
600     Writer.AddSourceLocation(TL.getProtocolLoc(i), Record);
601 }
602 void TypeLocWriter::VisitObjCObjectPointerTypeLoc(ObjCObjectPointerTypeLoc TL) {
603   Writer.AddSourceLocation(TL.getStarLoc(), Record);
604 }
605 void TypeLocWriter::VisitAtomicTypeLoc(AtomicTypeLoc TL) {
606   Writer.AddSourceLocation(TL.getKWLoc(), Record);
607   Writer.AddSourceLocation(TL.getLParenLoc(), Record);
608   Writer.AddSourceLocation(TL.getRParenLoc(), Record);
609 }
610 
611 //===----------------------------------------------------------------------===//
612 // ASTWriter Implementation
613 //===----------------------------------------------------------------------===//
614 
615 static void EmitBlockID(unsigned ID, const char *Name,
616                         llvm::BitstreamWriter &Stream,
617                         ASTWriter::RecordDataImpl &Record) {
618   Record.clear();
619   Record.push_back(ID);
620   Stream.EmitRecord(llvm::bitc::BLOCKINFO_CODE_SETBID, Record);
621 
622   // Emit the block name if present.
623   if (Name == 0 || Name[0] == 0) return;
624   Record.clear();
625   while (*Name)
626     Record.push_back(*Name++);
627   Stream.EmitRecord(llvm::bitc::BLOCKINFO_CODE_BLOCKNAME, Record);
628 }
629 
630 static void EmitRecordID(unsigned ID, const char *Name,
631                          llvm::BitstreamWriter &Stream,
632                          ASTWriter::RecordDataImpl &Record) {
633   Record.clear();
634   Record.push_back(ID);
635   while (*Name)
636     Record.push_back(*Name++);
637   Stream.EmitRecord(llvm::bitc::BLOCKINFO_CODE_SETRECORDNAME, Record);
638 }
639 
640 static void AddStmtsExprs(llvm::BitstreamWriter &Stream,
641                           ASTWriter::RecordDataImpl &Record) {
642 #define RECORD(X) EmitRecordID(X, #X, Stream, Record)
643   RECORD(STMT_STOP);
644   RECORD(STMT_NULL_PTR);
645   RECORD(STMT_NULL);
646   RECORD(STMT_COMPOUND);
647   RECORD(STMT_CASE);
648   RECORD(STMT_DEFAULT);
649   RECORD(STMT_LABEL);
650   RECORD(STMT_IF);
651   RECORD(STMT_SWITCH);
652   RECORD(STMT_WHILE);
653   RECORD(STMT_DO);
654   RECORD(STMT_FOR);
655   RECORD(STMT_GOTO);
656   RECORD(STMT_INDIRECT_GOTO);
657   RECORD(STMT_CONTINUE);
658   RECORD(STMT_BREAK);
659   RECORD(STMT_RETURN);
660   RECORD(STMT_DECL);
661   RECORD(STMT_ASM);
662   RECORD(EXPR_PREDEFINED);
663   RECORD(EXPR_DECL_REF);
664   RECORD(EXPR_INTEGER_LITERAL);
665   RECORD(EXPR_FLOATING_LITERAL);
666   RECORD(EXPR_IMAGINARY_LITERAL);
667   RECORD(EXPR_STRING_LITERAL);
668   RECORD(EXPR_CHARACTER_LITERAL);
669   RECORD(EXPR_PAREN);
670   RECORD(EXPR_UNARY_OPERATOR);
671   RECORD(EXPR_SIZEOF_ALIGN_OF);
672   RECORD(EXPR_ARRAY_SUBSCRIPT);
673   RECORD(EXPR_CALL);
674   RECORD(EXPR_MEMBER);
675   RECORD(EXPR_BINARY_OPERATOR);
676   RECORD(EXPR_COMPOUND_ASSIGN_OPERATOR);
677   RECORD(EXPR_CONDITIONAL_OPERATOR);
678   RECORD(EXPR_IMPLICIT_CAST);
679   RECORD(EXPR_CSTYLE_CAST);
680   RECORD(EXPR_COMPOUND_LITERAL);
681   RECORD(EXPR_EXT_VECTOR_ELEMENT);
682   RECORD(EXPR_INIT_LIST);
683   RECORD(EXPR_DESIGNATED_INIT);
684   RECORD(EXPR_IMPLICIT_VALUE_INIT);
685   RECORD(EXPR_VA_ARG);
686   RECORD(EXPR_ADDR_LABEL);
687   RECORD(EXPR_STMT);
688   RECORD(EXPR_CHOOSE);
689   RECORD(EXPR_GNU_NULL);
690   RECORD(EXPR_SHUFFLE_VECTOR);
691   RECORD(EXPR_BLOCK);
692   RECORD(EXPR_BLOCK_DECL_REF);
693   RECORD(EXPR_GENERIC_SELECTION);
694   RECORD(EXPR_OBJC_STRING_LITERAL);
695   RECORD(EXPR_OBJC_ENCODE);
696   RECORD(EXPR_OBJC_SELECTOR_EXPR);
697   RECORD(EXPR_OBJC_PROTOCOL_EXPR);
698   RECORD(EXPR_OBJC_IVAR_REF_EXPR);
699   RECORD(EXPR_OBJC_PROPERTY_REF_EXPR);
700   RECORD(EXPR_OBJC_KVC_REF_EXPR);
701   RECORD(EXPR_OBJC_MESSAGE_EXPR);
702   RECORD(STMT_OBJC_FOR_COLLECTION);
703   RECORD(STMT_OBJC_CATCH);
704   RECORD(STMT_OBJC_FINALLY);
705   RECORD(STMT_OBJC_AT_TRY);
706   RECORD(STMT_OBJC_AT_SYNCHRONIZED);
707   RECORD(STMT_OBJC_AT_THROW);
708   RECORD(EXPR_CXX_OPERATOR_CALL);
709   RECORD(EXPR_CXX_CONSTRUCT);
710   RECORD(EXPR_CXX_STATIC_CAST);
711   RECORD(EXPR_CXX_DYNAMIC_CAST);
712   RECORD(EXPR_CXX_REINTERPRET_CAST);
713   RECORD(EXPR_CXX_CONST_CAST);
714   RECORD(EXPR_CXX_FUNCTIONAL_CAST);
715   RECORD(EXPR_CXX_BOOL_LITERAL);
716   RECORD(EXPR_CXX_NULL_PTR_LITERAL);
717   RECORD(EXPR_CXX_TYPEID_EXPR);
718   RECORD(EXPR_CXX_TYPEID_TYPE);
719   RECORD(EXPR_CXX_UUIDOF_EXPR);
720   RECORD(EXPR_CXX_UUIDOF_TYPE);
721   RECORD(EXPR_CXX_THIS);
722   RECORD(EXPR_CXX_THROW);
723   RECORD(EXPR_CXX_DEFAULT_ARG);
724   RECORD(EXPR_CXX_BIND_TEMPORARY);
725   RECORD(EXPR_CXX_SCALAR_VALUE_INIT);
726   RECORD(EXPR_CXX_NEW);
727   RECORD(EXPR_CXX_DELETE);
728   RECORD(EXPR_CXX_PSEUDO_DESTRUCTOR);
729   RECORD(EXPR_EXPR_WITH_CLEANUPS);
730   RECORD(EXPR_CXX_DEPENDENT_SCOPE_MEMBER);
731   RECORD(EXPR_CXX_DEPENDENT_SCOPE_DECL_REF);
732   RECORD(EXPR_CXX_UNRESOLVED_CONSTRUCT);
733   RECORD(EXPR_CXX_UNRESOLVED_MEMBER);
734   RECORD(EXPR_CXX_UNRESOLVED_LOOKUP);
735   RECORD(EXPR_CXX_UNARY_TYPE_TRAIT);
736   RECORD(EXPR_CXX_NOEXCEPT);
737   RECORD(EXPR_OPAQUE_VALUE);
738   RECORD(EXPR_BINARY_TYPE_TRAIT);
739   RECORD(EXPR_PACK_EXPANSION);
740   RECORD(EXPR_SIZEOF_PACK);
741   RECORD(EXPR_SUBST_NON_TYPE_TEMPLATE_PARM_PACK);
742   RECORD(EXPR_CUDA_KERNEL_CALL);
743 #undef RECORD
744 }
745 
746 void ASTWriter::WriteBlockInfoBlock() {
747   RecordData Record;
748   Stream.EnterSubblock(llvm::bitc::BLOCKINFO_BLOCK_ID, 3);
749 
750 #define BLOCK(X) EmitBlockID(X ## _ID, #X, Stream, Record)
751 #define RECORD(X) EmitRecordID(X, #X, Stream, Record)
752 
753   // AST Top-Level Block.
754   BLOCK(AST_BLOCK);
755   RECORD(ORIGINAL_FILE_NAME);
756   RECORD(ORIGINAL_FILE_ID);
757   RECORD(TYPE_OFFSET);
758   RECORD(DECL_OFFSET);
759   RECORD(LANGUAGE_OPTIONS);
760   RECORD(METADATA);
761   RECORD(IDENTIFIER_OFFSET);
762   RECORD(IDENTIFIER_TABLE);
763   RECORD(EXTERNAL_DEFINITIONS);
764   RECORD(SPECIAL_TYPES);
765   RECORD(STATISTICS);
766   RECORD(TENTATIVE_DEFINITIONS);
767   RECORD(UNUSED_FILESCOPED_DECLS);
768   RECORD(LOCALLY_SCOPED_EXTERNAL_DECLS);
769   RECORD(SELECTOR_OFFSETS);
770   RECORD(METHOD_POOL);
771   RECORD(PP_COUNTER_VALUE);
772   RECORD(SOURCE_LOCATION_OFFSETS);
773   RECORD(SOURCE_LOCATION_PRELOADS);
774   RECORD(STAT_CACHE);
775   RECORD(EXT_VECTOR_DECLS);
776   RECORD(VERSION_CONTROL_BRANCH_REVISION);
777   RECORD(PPD_ENTITIES_OFFSETS);
778   RECORD(IMPORTS);
779   RECORD(REFERENCED_SELECTOR_POOL);
780   RECORD(TU_UPDATE_LEXICAL);
781   RECORD(LOCAL_REDECLARATIONS_MAP);
782   RECORD(SEMA_DECL_REFS);
783   RECORD(WEAK_UNDECLARED_IDENTIFIERS);
784   RECORD(PENDING_IMPLICIT_INSTANTIATIONS);
785   RECORD(DECL_REPLACEMENTS);
786   RECORD(UPDATE_VISIBLE);
787   RECORD(DECL_UPDATE_OFFSETS);
788   RECORD(DECL_UPDATES);
789   RECORD(CXX_BASE_SPECIFIER_OFFSETS);
790   RECORD(DIAG_PRAGMA_MAPPINGS);
791   RECORD(CUDA_SPECIAL_DECL_REFS);
792   RECORD(HEADER_SEARCH_TABLE);
793   RECORD(ORIGINAL_PCH_DIR);
794   RECORD(FP_PRAGMA_OPTIONS);
795   RECORD(OPENCL_EXTENSIONS);
796   RECORD(DELEGATING_CTORS);
797   RECORD(FILE_SOURCE_LOCATION_OFFSETS);
798   RECORD(KNOWN_NAMESPACES);
799   RECORD(MODULE_OFFSET_MAP);
800   RECORD(SOURCE_MANAGER_LINE_TABLE);
801   RECORD(OBJC_CHAINED_CATEGORIES);
802   RECORD(FILE_SORTED_DECLS);
803   RECORD(IMPORTED_MODULES);
804   RECORD(MERGED_DECLARATIONS);
805   RECORD(LOCAL_REDECLARATIONS);
806 
807   // SourceManager Block.
808   BLOCK(SOURCE_MANAGER_BLOCK);
809   RECORD(SM_SLOC_FILE_ENTRY);
810   RECORD(SM_SLOC_BUFFER_ENTRY);
811   RECORD(SM_SLOC_BUFFER_BLOB);
812   RECORD(SM_SLOC_EXPANSION_ENTRY);
813 
814   // Preprocessor Block.
815   BLOCK(PREPROCESSOR_BLOCK);
816   RECORD(PP_MACRO_OBJECT_LIKE);
817   RECORD(PP_MACRO_FUNCTION_LIKE);
818   RECORD(PP_TOKEN);
819 
820   // Decls and Types block.
821   BLOCK(DECLTYPES_BLOCK);
822   RECORD(TYPE_EXT_QUAL);
823   RECORD(TYPE_COMPLEX);
824   RECORD(TYPE_POINTER);
825   RECORD(TYPE_BLOCK_POINTER);
826   RECORD(TYPE_LVALUE_REFERENCE);
827   RECORD(TYPE_RVALUE_REFERENCE);
828   RECORD(TYPE_MEMBER_POINTER);
829   RECORD(TYPE_CONSTANT_ARRAY);
830   RECORD(TYPE_INCOMPLETE_ARRAY);
831   RECORD(TYPE_VARIABLE_ARRAY);
832   RECORD(TYPE_VECTOR);
833   RECORD(TYPE_EXT_VECTOR);
834   RECORD(TYPE_FUNCTION_PROTO);
835   RECORD(TYPE_FUNCTION_NO_PROTO);
836   RECORD(TYPE_TYPEDEF);
837   RECORD(TYPE_TYPEOF_EXPR);
838   RECORD(TYPE_TYPEOF);
839   RECORD(TYPE_RECORD);
840   RECORD(TYPE_ENUM);
841   RECORD(TYPE_OBJC_INTERFACE);
842   RECORD(TYPE_OBJC_OBJECT);
843   RECORD(TYPE_OBJC_OBJECT_POINTER);
844   RECORD(TYPE_DECLTYPE);
845   RECORD(TYPE_ELABORATED);
846   RECORD(TYPE_SUBST_TEMPLATE_TYPE_PARM);
847   RECORD(TYPE_UNRESOLVED_USING);
848   RECORD(TYPE_INJECTED_CLASS_NAME);
849   RECORD(TYPE_OBJC_OBJECT);
850   RECORD(TYPE_TEMPLATE_TYPE_PARM);
851   RECORD(TYPE_TEMPLATE_SPECIALIZATION);
852   RECORD(TYPE_DEPENDENT_NAME);
853   RECORD(TYPE_DEPENDENT_TEMPLATE_SPECIALIZATION);
854   RECORD(TYPE_DEPENDENT_SIZED_ARRAY);
855   RECORD(TYPE_PAREN);
856   RECORD(TYPE_PACK_EXPANSION);
857   RECORD(TYPE_ATTRIBUTED);
858   RECORD(TYPE_SUBST_TEMPLATE_TYPE_PARM_PACK);
859   RECORD(TYPE_ATOMIC);
860   RECORD(DECL_TYPEDEF);
861   RECORD(DECL_ENUM);
862   RECORD(DECL_RECORD);
863   RECORD(DECL_ENUM_CONSTANT);
864   RECORD(DECL_FUNCTION);
865   RECORD(DECL_OBJC_METHOD);
866   RECORD(DECL_OBJC_INTERFACE);
867   RECORD(DECL_OBJC_PROTOCOL);
868   RECORD(DECL_OBJC_IVAR);
869   RECORD(DECL_OBJC_AT_DEFS_FIELD);
870   RECORD(DECL_OBJC_CATEGORY);
871   RECORD(DECL_OBJC_CATEGORY_IMPL);
872   RECORD(DECL_OBJC_IMPLEMENTATION);
873   RECORD(DECL_OBJC_COMPATIBLE_ALIAS);
874   RECORD(DECL_OBJC_PROPERTY);
875   RECORD(DECL_OBJC_PROPERTY_IMPL);
876   RECORD(DECL_FIELD);
877   RECORD(DECL_VAR);
878   RECORD(DECL_IMPLICIT_PARAM);
879   RECORD(DECL_PARM_VAR);
880   RECORD(DECL_FILE_SCOPE_ASM);
881   RECORD(DECL_BLOCK);
882   RECORD(DECL_CONTEXT_LEXICAL);
883   RECORD(DECL_CONTEXT_VISIBLE);
884   RECORD(DECL_NAMESPACE);
885   RECORD(DECL_NAMESPACE_ALIAS);
886   RECORD(DECL_USING);
887   RECORD(DECL_USING_SHADOW);
888   RECORD(DECL_USING_DIRECTIVE);
889   RECORD(DECL_UNRESOLVED_USING_VALUE);
890   RECORD(DECL_UNRESOLVED_USING_TYPENAME);
891   RECORD(DECL_LINKAGE_SPEC);
892   RECORD(DECL_CXX_RECORD);
893   RECORD(DECL_CXX_METHOD);
894   RECORD(DECL_CXX_CONSTRUCTOR);
895   RECORD(DECL_CXX_DESTRUCTOR);
896   RECORD(DECL_CXX_CONVERSION);
897   RECORD(DECL_ACCESS_SPEC);
898   RECORD(DECL_FRIEND);
899   RECORD(DECL_FRIEND_TEMPLATE);
900   RECORD(DECL_CLASS_TEMPLATE);
901   RECORD(DECL_CLASS_TEMPLATE_SPECIALIZATION);
902   RECORD(DECL_CLASS_TEMPLATE_PARTIAL_SPECIALIZATION);
903   RECORD(DECL_FUNCTION_TEMPLATE);
904   RECORD(DECL_TEMPLATE_TYPE_PARM);
905   RECORD(DECL_NON_TYPE_TEMPLATE_PARM);
906   RECORD(DECL_TEMPLATE_TEMPLATE_PARM);
907   RECORD(DECL_STATIC_ASSERT);
908   RECORD(DECL_CXX_BASE_SPECIFIERS);
909   RECORD(DECL_INDIRECTFIELD);
910   RECORD(DECL_EXPANDED_NON_TYPE_TEMPLATE_PARM_PACK);
911 
912   // Statements and Exprs can occur in the Decls and Types block.
913   AddStmtsExprs(Stream, Record);
914 
915   BLOCK(PREPROCESSOR_DETAIL_BLOCK);
916   RECORD(PPD_MACRO_EXPANSION);
917   RECORD(PPD_MACRO_DEFINITION);
918   RECORD(PPD_INCLUSION_DIRECTIVE);
919 
920 #undef RECORD
921 #undef BLOCK
922   Stream.ExitBlock();
923 }
924 
925 /// \brief Adjusts the given filename to only write out the portion of the
926 /// filename that is not part of the system root directory.
927 ///
928 /// \param Filename the file name to adjust.
929 ///
930 /// \param isysroot When non-NULL, the PCH file is a relocatable PCH file and
931 /// the returned filename will be adjusted by this system root.
932 ///
933 /// \returns either the original filename (if it needs no adjustment) or the
934 /// adjusted filename (which points into the @p Filename parameter).
935 static const char *
936 adjustFilenameForRelocatablePCH(const char *Filename, StringRef isysroot) {
937   assert(Filename && "No file name to adjust?");
938 
939   if (isysroot.empty())
940     return Filename;
941 
942   // Verify that the filename and the system root have the same prefix.
943   unsigned Pos = 0;
944   for (; Filename[Pos] && Pos < isysroot.size(); ++Pos)
945     if (Filename[Pos] != isysroot[Pos])
946       return Filename; // Prefixes don't match.
947 
948   // We hit the end of the filename before we hit the end of the system root.
949   if (!Filename[Pos])
950     return Filename;
951 
952   // If the file name has a '/' at the current position, skip over the '/'.
953   // We distinguish sysroot-based includes from absolute includes by the
954   // absence of '/' at the beginning of sysroot-based includes.
955   if (Filename[Pos] == '/')
956     ++Pos;
957 
958   return Filename + Pos;
959 }
960 
961 /// \brief Write the AST metadata (e.g., i686-apple-darwin9).
962 void ASTWriter::WriteMetadata(ASTContext &Context, StringRef isysroot,
963                               const std::string &OutputFile) {
964   using namespace llvm;
965 
966   // Metadata
967   const TargetInfo &Target = Context.getTargetInfo();
968   BitCodeAbbrev *MetaAbbrev = new BitCodeAbbrev();
969   MetaAbbrev->Add(BitCodeAbbrevOp(METADATA));
970   MetaAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 16)); // AST major
971   MetaAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 16)); // AST minor
972   MetaAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 16)); // Clang major
973   MetaAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 16)); // Clang minor
974   MetaAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Relocatable
975   MetaAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Target triple
976   unsigned MetaAbbrevCode = Stream.EmitAbbrev(MetaAbbrev);
977 
978   RecordData Record;
979   Record.push_back(METADATA);
980   Record.push_back(VERSION_MAJOR);
981   Record.push_back(VERSION_MINOR);
982   Record.push_back(CLANG_VERSION_MAJOR);
983   Record.push_back(CLANG_VERSION_MINOR);
984   Record.push_back(!isysroot.empty());
985   const std::string &Triple = Target.getTriple().getTriple();
986   Stream.EmitRecordWithBlob(MetaAbbrevCode, Record, Triple);
987 
988   if (Chain) {
989     serialization::ModuleManager &Mgr = Chain->getModuleManager();
990     llvm::SmallVector<char, 128> ModulePaths;
991     Record.clear();
992 
993     for (ModuleManager::ModuleIterator M = Mgr.begin(), MEnd = Mgr.end();
994          M != MEnd; ++M) {
995       // Skip modules that weren't directly imported.
996       if (!(*M)->isDirectlyImported())
997         continue;
998 
999       Record.push_back((unsigned)(*M)->Kind); // FIXME: Stable encoding
1000       // FIXME: Write import location, once it matters.
1001       // FIXME: This writes the absolute path for AST files we depend on.
1002       const std::string &FileName = (*M)->FileName;
1003       Record.push_back(FileName.size());
1004       Record.append(FileName.begin(), FileName.end());
1005     }
1006     Stream.EmitRecord(IMPORTS, Record);
1007   }
1008 
1009   // Original file name and file ID
1010   SourceManager &SM = Context.getSourceManager();
1011   if (const FileEntry *MainFile = SM.getFileEntryForID(SM.getMainFileID())) {
1012     BitCodeAbbrev *FileAbbrev = new BitCodeAbbrev();
1013     FileAbbrev->Add(BitCodeAbbrevOp(ORIGINAL_FILE_NAME));
1014     FileAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // File name
1015     unsigned FileAbbrevCode = Stream.EmitAbbrev(FileAbbrev);
1016 
1017     llvm::SmallString<128> MainFilePath(MainFile->getName());
1018 
1019     llvm::sys::fs::make_absolute(MainFilePath);
1020 
1021     const char *MainFileNameStr = MainFilePath.c_str();
1022     MainFileNameStr = adjustFilenameForRelocatablePCH(MainFileNameStr,
1023                                                       isysroot);
1024     RecordData Record;
1025     Record.push_back(ORIGINAL_FILE_NAME);
1026     Stream.EmitRecordWithBlob(FileAbbrevCode, Record, MainFileNameStr);
1027 
1028     Record.clear();
1029     Record.push_back(SM.getMainFileID().getOpaqueValue());
1030     Stream.EmitRecord(ORIGINAL_FILE_ID, Record);
1031   }
1032 
1033   // Original PCH directory
1034   if (!OutputFile.empty() && OutputFile != "-") {
1035     BitCodeAbbrev *Abbrev = new BitCodeAbbrev();
1036     Abbrev->Add(BitCodeAbbrevOp(ORIGINAL_PCH_DIR));
1037     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // File name
1038     unsigned AbbrevCode = Stream.EmitAbbrev(Abbrev);
1039 
1040     llvm::SmallString<128> OutputPath(OutputFile);
1041 
1042     llvm::sys::fs::make_absolute(OutputPath);
1043     StringRef origDir = llvm::sys::path::parent_path(OutputPath);
1044 
1045     RecordData Record;
1046     Record.push_back(ORIGINAL_PCH_DIR);
1047     Stream.EmitRecordWithBlob(AbbrevCode, Record, origDir);
1048   }
1049 
1050   // Repository branch/version information.
1051   BitCodeAbbrev *RepoAbbrev = new BitCodeAbbrev();
1052   RepoAbbrev->Add(BitCodeAbbrevOp(VERSION_CONTROL_BRANCH_REVISION));
1053   RepoAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // SVN branch/tag
1054   unsigned RepoAbbrevCode = Stream.EmitAbbrev(RepoAbbrev);
1055   Record.clear();
1056   Record.push_back(VERSION_CONTROL_BRANCH_REVISION);
1057   Stream.EmitRecordWithBlob(RepoAbbrevCode, Record,
1058                             getClangFullRepositoryVersion());
1059 }
1060 
1061 /// \brief Write the LangOptions structure.
1062 void ASTWriter::WriteLanguageOptions(const LangOptions &LangOpts) {
1063   RecordData Record;
1064 #define LANGOPT(Name, Bits, Default, Description) \
1065   Record.push_back(LangOpts.Name);
1066 #define ENUM_LANGOPT(Name, Type, Bits, Default, Description) \
1067   Record.push_back(static_cast<unsigned>(LangOpts.get##Name()));
1068 #include "clang/Basic/LangOptions.def"
1069 
1070   Record.push_back(LangOpts.CurrentModule.size());
1071   Record.append(LangOpts.CurrentModule.begin(), LangOpts.CurrentModule.end());
1072   Stream.EmitRecord(LANGUAGE_OPTIONS, Record);
1073 }
1074 
1075 //===----------------------------------------------------------------------===//
1076 // stat cache Serialization
1077 //===----------------------------------------------------------------------===//
1078 
1079 namespace {
1080 // Trait used for the on-disk hash table of stat cache results.
1081 class ASTStatCacheTrait {
1082 public:
1083   typedef const char * key_type;
1084   typedef key_type key_type_ref;
1085 
1086   typedef struct stat data_type;
1087   typedef const data_type &data_type_ref;
1088 
1089   static unsigned ComputeHash(const char *path) {
1090     return llvm::HashString(path);
1091   }
1092 
1093   std::pair<unsigned,unsigned>
1094     EmitKeyDataLength(raw_ostream& Out, const char *path,
1095                       data_type_ref Data) {
1096     unsigned StrLen = strlen(path);
1097     clang::io::Emit16(Out, StrLen);
1098     unsigned DataLen = 4 + 4 + 2 + 8 + 8;
1099     clang::io::Emit8(Out, DataLen);
1100     return std::make_pair(StrLen + 1, DataLen);
1101   }
1102 
1103   void EmitKey(raw_ostream& Out, const char *path, unsigned KeyLen) {
1104     Out.write(path, KeyLen);
1105   }
1106 
1107   void EmitData(raw_ostream &Out, key_type_ref,
1108                 data_type_ref Data, unsigned DataLen) {
1109     using namespace clang::io;
1110     uint64_t Start = Out.tell(); (void)Start;
1111 
1112     Emit32(Out, (uint32_t) Data.st_ino);
1113     Emit32(Out, (uint32_t) Data.st_dev);
1114     Emit16(Out, (uint16_t) Data.st_mode);
1115     Emit64(Out, (uint64_t) Data.st_mtime);
1116     Emit64(Out, (uint64_t) Data.st_size);
1117 
1118     assert(Out.tell() - Start == DataLen && "Wrong data length");
1119   }
1120 };
1121 } // end anonymous namespace
1122 
1123 /// \brief Write the stat() system call cache to the AST file.
1124 void ASTWriter::WriteStatCache(MemorizeStatCalls &StatCalls) {
1125   // Build the on-disk hash table containing information about every
1126   // stat() call.
1127   OnDiskChainedHashTableGenerator<ASTStatCacheTrait> Generator;
1128   unsigned NumStatEntries = 0;
1129   for (MemorizeStatCalls::iterator Stat = StatCalls.begin(),
1130                                 StatEnd = StatCalls.end();
1131        Stat != StatEnd; ++Stat, ++NumStatEntries) {
1132     StringRef Filename = Stat->first();
1133     Generator.insert(Filename.data(), Stat->second);
1134   }
1135 
1136   // Create the on-disk hash table in a buffer.
1137   llvm::SmallString<4096> StatCacheData;
1138   uint32_t BucketOffset;
1139   {
1140     llvm::raw_svector_ostream Out(StatCacheData);
1141     // Make sure that no bucket is at offset 0
1142     clang::io::Emit32(Out, 0);
1143     BucketOffset = Generator.Emit(Out);
1144   }
1145 
1146   // Create a blob abbreviation
1147   using namespace llvm;
1148   BitCodeAbbrev *Abbrev = new BitCodeAbbrev();
1149   Abbrev->Add(BitCodeAbbrevOp(STAT_CACHE));
1150   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
1151   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
1152   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
1153   unsigned StatCacheAbbrev = Stream.EmitAbbrev(Abbrev);
1154 
1155   // Write the stat cache
1156   RecordData Record;
1157   Record.push_back(STAT_CACHE);
1158   Record.push_back(BucketOffset);
1159   Record.push_back(NumStatEntries);
1160   Stream.EmitRecordWithBlob(StatCacheAbbrev, Record, StatCacheData.str());
1161 }
1162 
1163 //===----------------------------------------------------------------------===//
1164 // Source Manager Serialization
1165 //===----------------------------------------------------------------------===//
1166 
1167 /// \brief Create an abbreviation for the SLocEntry that refers to a
1168 /// file.
1169 static unsigned CreateSLocFileAbbrev(llvm::BitstreamWriter &Stream) {
1170   using namespace llvm;
1171   BitCodeAbbrev *Abbrev = new BitCodeAbbrev();
1172   Abbrev->Add(BitCodeAbbrevOp(SM_SLOC_FILE_ENTRY));
1173   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // Offset
1174   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // Include location
1175   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2)); // Characteristic
1176   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Line directives
1177   // FileEntry fields.
1178   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 12)); // Size
1179   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 32)); // Modification time
1180   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // BufferOverridden
1181   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // NumCreatedFIDs
1182   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 24)); // FirstDeclIndex
1183   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // NumDecls
1184   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // File name
1185   return Stream.EmitAbbrev(Abbrev);
1186 }
1187 
1188 /// \brief Create an abbreviation for the SLocEntry that refers to a
1189 /// buffer.
1190 static unsigned CreateSLocBufferAbbrev(llvm::BitstreamWriter &Stream) {
1191   using namespace llvm;
1192   BitCodeAbbrev *Abbrev = new BitCodeAbbrev();
1193   Abbrev->Add(BitCodeAbbrevOp(SM_SLOC_BUFFER_ENTRY));
1194   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // Offset
1195   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // Include location
1196   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2)); // Characteristic
1197   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Line directives
1198   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Buffer name blob
1199   return Stream.EmitAbbrev(Abbrev);
1200 }
1201 
1202 /// \brief Create an abbreviation for the SLocEntry that refers to a
1203 /// buffer's blob.
1204 static unsigned CreateSLocBufferBlobAbbrev(llvm::BitstreamWriter &Stream) {
1205   using namespace llvm;
1206   BitCodeAbbrev *Abbrev = new BitCodeAbbrev();
1207   Abbrev->Add(BitCodeAbbrevOp(SM_SLOC_BUFFER_BLOB));
1208   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Blob
1209   return Stream.EmitAbbrev(Abbrev);
1210 }
1211 
1212 /// \brief Create an abbreviation for the SLocEntry that refers to a macro
1213 /// expansion.
1214 static unsigned CreateSLocExpansionAbbrev(llvm::BitstreamWriter &Stream) {
1215   using namespace llvm;
1216   BitCodeAbbrev *Abbrev = new BitCodeAbbrev();
1217   Abbrev->Add(BitCodeAbbrevOp(SM_SLOC_EXPANSION_ENTRY));
1218   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // Offset
1219   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // Spelling location
1220   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // Start location
1221   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // End location
1222   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Token length
1223   return Stream.EmitAbbrev(Abbrev);
1224 }
1225 
1226 namespace {
1227   // Trait used for the on-disk hash table of header search information.
1228   class HeaderFileInfoTrait {
1229     ASTWriter &Writer;
1230     const HeaderSearch &HS;
1231 
1232     // Keep track of the framework names we've used during serialization.
1233     SmallVector<char, 128> FrameworkStringData;
1234     llvm::StringMap<unsigned> FrameworkNameOffset;
1235 
1236   public:
1237     HeaderFileInfoTrait(ASTWriter &Writer, const HeaderSearch &HS)
1238       : Writer(Writer), HS(HS) { }
1239 
1240     typedef const char *key_type;
1241     typedef key_type key_type_ref;
1242 
1243     typedef HeaderFileInfo data_type;
1244     typedef const data_type &data_type_ref;
1245 
1246     static unsigned ComputeHash(const char *path) {
1247       // The hash is based only on the filename portion of the key, so that the
1248       // reader can match based on filenames when symlinking or excess path
1249       // elements ("foo/../", "../") change the form of the name. However,
1250       // complete path is still the key.
1251       return llvm::HashString(llvm::sys::path::filename(path));
1252     }
1253 
1254     std::pair<unsigned,unsigned>
1255     EmitKeyDataLength(raw_ostream& Out, const char *path,
1256                       data_type_ref Data) {
1257       unsigned StrLen = strlen(path);
1258       clang::io::Emit16(Out, StrLen);
1259       unsigned DataLen = 1 + 2 + 4 + 4;
1260       clang::io::Emit8(Out, DataLen);
1261       return std::make_pair(StrLen + 1, DataLen);
1262     }
1263 
1264     void EmitKey(raw_ostream& Out, const char *path, unsigned KeyLen) {
1265       Out.write(path, KeyLen);
1266     }
1267 
1268     void EmitData(raw_ostream &Out, key_type_ref,
1269                   data_type_ref Data, unsigned DataLen) {
1270       using namespace clang::io;
1271       uint64_t Start = Out.tell(); (void)Start;
1272 
1273       unsigned char Flags = (Data.isImport << 5)
1274                           | (Data.isPragmaOnce << 4)
1275                           | (Data.DirInfo << 2)
1276                           | (Data.Resolved << 1)
1277                           | Data.IndexHeaderMapHeader;
1278       Emit8(Out, (uint8_t)Flags);
1279       Emit16(Out, (uint16_t) Data.NumIncludes);
1280 
1281       if (!Data.ControllingMacro)
1282         Emit32(Out, (uint32_t)Data.ControllingMacroID);
1283       else
1284         Emit32(Out, (uint32_t)Writer.getIdentifierRef(Data.ControllingMacro));
1285 
1286       unsigned Offset = 0;
1287       if (!Data.Framework.empty()) {
1288         // If this header refers into a framework, save the framework name.
1289         llvm::StringMap<unsigned>::iterator Pos
1290           = FrameworkNameOffset.find(Data.Framework);
1291         if (Pos == FrameworkNameOffset.end()) {
1292           Offset = FrameworkStringData.size() + 1;
1293           FrameworkStringData.append(Data.Framework.begin(),
1294                                      Data.Framework.end());
1295           FrameworkStringData.push_back(0);
1296 
1297           FrameworkNameOffset[Data.Framework] = Offset;
1298         } else
1299           Offset = Pos->second;
1300       }
1301       Emit32(Out, Offset);
1302 
1303       assert(Out.tell() - Start == DataLen && "Wrong data length");
1304     }
1305 
1306     const char *strings_begin() const { return FrameworkStringData.begin(); }
1307     const char *strings_end() const { return FrameworkStringData.end(); }
1308   };
1309 } // end anonymous namespace
1310 
1311 /// \brief Write the header search block for the list of files that
1312 ///
1313 /// \param HS The header search structure to save.
1314 ///
1315 /// \param Chain Whether we're creating a chained AST file.
1316 void ASTWriter::WriteHeaderSearch(const HeaderSearch &HS, StringRef isysroot) {
1317   SmallVector<const FileEntry *, 16> FilesByUID;
1318   HS.getFileMgr().GetUniqueIDMapping(FilesByUID);
1319 
1320   if (FilesByUID.size() > HS.header_file_size())
1321     FilesByUID.resize(HS.header_file_size());
1322 
1323   HeaderFileInfoTrait GeneratorTrait(*this, HS);
1324   OnDiskChainedHashTableGenerator<HeaderFileInfoTrait> Generator;
1325   SmallVector<const char *, 4> SavedStrings;
1326   unsigned NumHeaderSearchEntries = 0;
1327   for (unsigned UID = 0, LastUID = FilesByUID.size(); UID != LastUID; ++UID) {
1328     const FileEntry *File = FilesByUID[UID];
1329     if (!File)
1330       continue;
1331 
1332     // Use HeaderSearch's getFileInfo to make sure we get the HeaderFileInfo
1333     // from the external source if it was not provided already.
1334     const HeaderFileInfo &HFI = HS.getFileInfo(File);
1335     if (HFI.External && Chain)
1336       continue;
1337 
1338     // Turn the file name into an absolute path, if it isn't already.
1339     const char *Filename = File->getName();
1340     Filename = adjustFilenameForRelocatablePCH(Filename, isysroot);
1341 
1342     // If we performed any translation on the file name at all, we need to
1343     // save this string, since the generator will refer to it later.
1344     if (Filename != File->getName()) {
1345       Filename = strdup(Filename);
1346       SavedStrings.push_back(Filename);
1347     }
1348 
1349     Generator.insert(Filename, HFI, GeneratorTrait);
1350     ++NumHeaderSearchEntries;
1351   }
1352 
1353   // Create the on-disk hash table in a buffer.
1354   llvm::SmallString<4096> TableData;
1355   uint32_t BucketOffset;
1356   {
1357     llvm::raw_svector_ostream Out(TableData);
1358     // Make sure that no bucket is at offset 0
1359     clang::io::Emit32(Out, 0);
1360     BucketOffset = Generator.Emit(Out, GeneratorTrait);
1361   }
1362 
1363   // Create a blob abbreviation
1364   using namespace llvm;
1365   BitCodeAbbrev *Abbrev = new BitCodeAbbrev();
1366   Abbrev->Add(BitCodeAbbrevOp(HEADER_SEARCH_TABLE));
1367   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
1368   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
1369   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
1370   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
1371   unsigned TableAbbrev = Stream.EmitAbbrev(Abbrev);
1372 
1373   // Write the header search table
1374   RecordData Record;
1375   Record.push_back(HEADER_SEARCH_TABLE);
1376   Record.push_back(BucketOffset);
1377   Record.push_back(NumHeaderSearchEntries);
1378   Record.push_back(TableData.size());
1379   TableData.append(GeneratorTrait.strings_begin(),GeneratorTrait.strings_end());
1380   Stream.EmitRecordWithBlob(TableAbbrev, Record, TableData.str());
1381 
1382   // Free all of the strings we had to duplicate.
1383   for (unsigned I = 0, N = SavedStrings.size(); I != N; ++I)
1384     free((void*)SavedStrings[I]);
1385 }
1386 
1387 /// \brief Writes the block containing the serialized form of the
1388 /// source manager.
1389 ///
1390 /// TODO: We should probably use an on-disk hash table (stored in a
1391 /// blob), indexed based on the file name, so that we only create
1392 /// entries for files that we actually need. In the common case (no
1393 /// errors), we probably won't have to create file entries for any of
1394 /// the files in the AST.
1395 void ASTWriter::WriteSourceManagerBlock(SourceManager &SourceMgr,
1396                                         const Preprocessor &PP,
1397                                         StringRef isysroot) {
1398   RecordData Record;
1399 
1400   // Enter the source manager block.
1401   Stream.EnterSubblock(SOURCE_MANAGER_BLOCK_ID, 3);
1402 
1403   // Abbreviations for the various kinds of source-location entries.
1404   unsigned SLocFileAbbrv = CreateSLocFileAbbrev(Stream);
1405   unsigned SLocBufferAbbrv = CreateSLocBufferAbbrev(Stream);
1406   unsigned SLocBufferBlobAbbrv = CreateSLocBufferBlobAbbrev(Stream);
1407   unsigned SLocExpansionAbbrv = CreateSLocExpansionAbbrev(Stream);
1408 
1409   // Write out the source location entry table. We skip the first
1410   // entry, which is always the same dummy entry.
1411   std::vector<uint32_t> SLocEntryOffsets;
1412   // Write out the offsets of only source location file entries.
1413   // We will go through them in ASTReader::validateFileEntries().
1414   std::vector<uint32_t> SLocFileEntryOffsets;
1415   RecordData PreloadSLocs;
1416   SLocEntryOffsets.reserve(SourceMgr.local_sloc_entry_size() - 1);
1417   for (unsigned I = 1, N = SourceMgr.local_sloc_entry_size();
1418        I != N; ++I) {
1419     // Get this source location entry.
1420     const SrcMgr::SLocEntry *SLoc = &SourceMgr.getLocalSLocEntry(I);
1421 
1422     // Record the offset of this source-location entry.
1423     SLocEntryOffsets.push_back(Stream.GetCurrentBitNo());
1424 
1425     // Figure out which record code to use.
1426     unsigned Code;
1427     if (SLoc->isFile()) {
1428       const SrcMgr::ContentCache *Cache = SLoc->getFile().getContentCache();
1429       if (Cache->OrigEntry) {
1430         Code = SM_SLOC_FILE_ENTRY;
1431         SLocFileEntryOffsets.push_back(Stream.GetCurrentBitNo());
1432       } else
1433         Code = SM_SLOC_BUFFER_ENTRY;
1434     } else
1435       Code = SM_SLOC_EXPANSION_ENTRY;
1436     Record.clear();
1437     Record.push_back(Code);
1438 
1439     // Starting offset of this entry within this module, so skip the dummy.
1440     Record.push_back(SLoc->getOffset() - 2);
1441     if (SLoc->isFile()) {
1442       const SrcMgr::FileInfo &File = SLoc->getFile();
1443       Record.push_back(File.getIncludeLoc().getRawEncoding());
1444       Record.push_back(File.getFileCharacteristic()); // FIXME: stable encoding
1445       Record.push_back(File.hasLineDirectives());
1446 
1447       const SrcMgr::ContentCache *Content = File.getContentCache();
1448       if (Content->OrigEntry) {
1449         assert(Content->OrigEntry == Content->ContentsEntry &&
1450                "Writing to AST an overridden file is not supported");
1451 
1452         // The source location entry is a file. The blob associated
1453         // with this entry is the file name.
1454 
1455         // Emit size/modification time for this file.
1456         Record.push_back(Content->OrigEntry->getSize());
1457         Record.push_back(Content->OrigEntry->getModificationTime());
1458         Record.push_back(Content->BufferOverridden);
1459         Record.push_back(File.NumCreatedFIDs);
1460 
1461         FileDeclIDsTy::iterator FDI = FileDeclIDs.find(SLoc);
1462         if (FDI != FileDeclIDs.end()) {
1463           Record.push_back(FDI->second->FirstDeclIndex);
1464           Record.push_back(FDI->second->DeclIDs.size());
1465         } else {
1466           Record.push_back(0);
1467           Record.push_back(0);
1468         }
1469 
1470         // Turn the file name into an absolute path, if it isn't already.
1471         const char *Filename = Content->OrigEntry->getName();
1472         llvm::SmallString<128> FilePath(Filename);
1473 
1474         // Ask the file manager to fixup the relative path for us. This will
1475         // honor the working directory.
1476         SourceMgr.getFileManager().FixupRelativePath(FilePath);
1477 
1478         // FIXME: This call to make_absolute shouldn't be necessary, the
1479         // call to FixupRelativePath should always return an absolute path.
1480         llvm::sys::fs::make_absolute(FilePath);
1481         Filename = FilePath.c_str();
1482 
1483         Filename = adjustFilenameForRelocatablePCH(Filename, isysroot);
1484         Stream.EmitRecordWithBlob(SLocFileAbbrv, Record, Filename);
1485 
1486         if (Content->BufferOverridden) {
1487           Record.clear();
1488           Record.push_back(SM_SLOC_BUFFER_BLOB);
1489           const llvm::MemoryBuffer *Buffer
1490             = Content->getBuffer(PP.getDiagnostics(), PP.getSourceManager());
1491           Stream.EmitRecordWithBlob(SLocBufferBlobAbbrv, Record,
1492                                     StringRef(Buffer->getBufferStart(),
1493                                               Buffer->getBufferSize() + 1));
1494         }
1495       } else {
1496         // The source location entry is a buffer. The blob associated
1497         // with this entry contains the contents of the buffer.
1498 
1499         // We add one to the size so that we capture the trailing NULL
1500         // that is required by llvm::MemoryBuffer::getMemBuffer (on
1501         // the reader side).
1502         const llvm::MemoryBuffer *Buffer
1503           = Content->getBuffer(PP.getDiagnostics(), PP.getSourceManager());
1504         const char *Name = Buffer->getBufferIdentifier();
1505         Stream.EmitRecordWithBlob(SLocBufferAbbrv, Record,
1506                                   StringRef(Name, strlen(Name) + 1));
1507         Record.clear();
1508         Record.push_back(SM_SLOC_BUFFER_BLOB);
1509         Stream.EmitRecordWithBlob(SLocBufferBlobAbbrv, Record,
1510                                   StringRef(Buffer->getBufferStart(),
1511                                                   Buffer->getBufferSize() + 1));
1512 
1513         if (strcmp(Name, "<built-in>") == 0) {
1514           PreloadSLocs.push_back(SLocEntryOffsets.size());
1515         }
1516       }
1517     } else {
1518       // The source location entry is a macro expansion.
1519       const SrcMgr::ExpansionInfo &Expansion = SLoc->getExpansion();
1520       Record.push_back(Expansion.getSpellingLoc().getRawEncoding());
1521       Record.push_back(Expansion.getExpansionLocStart().getRawEncoding());
1522       Record.push_back(Expansion.isMacroArgExpansion() ? 0
1523                              : Expansion.getExpansionLocEnd().getRawEncoding());
1524 
1525       // Compute the token length for this macro expansion.
1526       unsigned NextOffset = SourceMgr.getNextLocalOffset();
1527       if (I + 1 != N)
1528         NextOffset = SourceMgr.getLocalSLocEntry(I + 1).getOffset();
1529       Record.push_back(NextOffset - SLoc->getOffset() - 1);
1530       Stream.EmitRecordWithAbbrev(SLocExpansionAbbrv, Record);
1531     }
1532   }
1533 
1534   Stream.ExitBlock();
1535 
1536   if (SLocEntryOffsets.empty())
1537     return;
1538 
1539   // Write the source-location offsets table into the AST block. This
1540   // table is used for lazily loading source-location information.
1541   using namespace llvm;
1542   BitCodeAbbrev *Abbrev = new BitCodeAbbrev();
1543   Abbrev->Add(BitCodeAbbrevOp(SOURCE_LOCATION_OFFSETS));
1544   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 16)); // # of slocs
1545   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 16)); // total size
1546   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // offsets
1547   unsigned SLocOffsetsAbbrev = Stream.EmitAbbrev(Abbrev);
1548 
1549   Record.clear();
1550   Record.push_back(SOURCE_LOCATION_OFFSETS);
1551   Record.push_back(SLocEntryOffsets.size());
1552   Record.push_back(SourceMgr.getNextLocalOffset() - 1); // skip dummy
1553   Stream.EmitRecordWithBlob(SLocOffsetsAbbrev, Record, data(SLocEntryOffsets));
1554 
1555   Abbrev = new BitCodeAbbrev();
1556   Abbrev->Add(BitCodeAbbrevOp(FILE_SOURCE_LOCATION_OFFSETS));
1557   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 16)); // # of slocs
1558   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // offsets
1559   unsigned SLocFileOffsetsAbbrev = Stream.EmitAbbrev(Abbrev);
1560 
1561   Record.clear();
1562   Record.push_back(FILE_SOURCE_LOCATION_OFFSETS);
1563   Record.push_back(SLocFileEntryOffsets.size());
1564   Stream.EmitRecordWithBlob(SLocFileOffsetsAbbrev, Record,
1565                             data(SLocFileEntryOffsets));
1566 
1567   // Write the source location entry preloads array, telling the AST
1568   // reader which source locations entries it should load eagerly.
1569   Stream.EmitRecord(SOURCE_LOCATION_PRELOADS, PreloadSLocs);
1570 
1571   // Write the line table. It depends on remapping working, so it must come
1572   // after the source location offsets.
1573   if (SourceMgr.hasLineTable()) {
1574     LineTableInfo &LineTable = SourceMgr.getLineTable();
1575 
1576     Record.clear();
1577     // Emit the file names
1578     Record.push_back(LineTable.getNumFilenames());
1579     for (unsigned I = 0, N = LineTable.getNumFilenames(); I != N; ++I) {
1580       // Emit the file name
1581       const char *Filename = LineTable.getFilename(I);
1582       Filename = adjustFilenameForRelocatablePCH(Filename, isysroot);
1583       unsigned FilenameLen = Filename? strlen(Filename) : 0;
1584       Record.push_back(FilenameLen);
1585       if (FilenameLen)
1586         Record.insert(Record.end(), Filename, Filename + FilenameLen);
1587     }
1588 
1589     // Emit the line entries
1590     for (LineTableInfo::iterator L = LineTable.begin(), LEnd = LineTable.end();
1591          L != LEnd; ++L) {
1592       // Only emit entries for local files.
1593       if (L->first < 0)
1594         continue;
1595 
1596       // Emit the file ID
1597       Record.push_back(L->first);
1598 
1599       // Emit the line entries
1600       Record.push_back(L->second.size());
1601       for (std::vector<LineEntry>::iterator LE = L->second.begin(),
1602                                          LEEnd = L->second.end();
1603            LE != LEEnd; ++LE) {
1604         Record.push_back(LE->FileOffset);
1605         Record.push_back(LE->LineNo);
1606         Record.push_back(LE->FilenameID);
1607         Record.push_back((unsigned)LE->FileKind);
1608         Record.push_back(LE->IncludeOffset);
1609       }
1610     }
1611     Stream.EmitRecord(SOURCE_MANAGER_LINE_TABLE, Record);
1612   }
1613 }
1614 
1615 //===----------------------------------------------------------------------===//
1616 // Preprocessor Serialization
1617 //===----------------------------------------------------------------------===//
1618 
1619 static int compareMacroDefinitions(const void *XPtr, const void *YPtr) {
1620   const std::pair<const IdentifierInfo *, MacroInfo *> &X =
1621     *(const std::pair<const IdentifierInfo *, MacroInfo *>*)XPtr;
1622   const std::pair<const IdentifierInfo *, MacroInfo *> &Y =
1623     *(const std::pair<const IdentifierInfo *, MacroInfo *>*)YPtr;
1624   return X.first->getName().compare(Y.first->getName());
1625 }
1626 
1627 /// \brief Writes the block containing the serialized form of the
1628 /// preprocessor.
1629 ///
1630 void ASTWriter::WritePreprocessor(const Preprocessor &PP, bool IsModule) {
1631   PreprocessingRecord *PPRec = PP.getPreprocessingRecord();
1632   if (PPRec)
1633     WritePreprocessorDetail(*PPRec);
1634 
1635   RecordData Record;
1636 
1637   // If the preprocessor __COUNTER__ value has been bumped, remember it.
1638   if (PP.getCounterValue() != 0) {
1639     Record.push_back(PP.getCounterValue());
1640     Stream.EmitRecord(PP_COUNTER_VALUE, Record);
1641     Record.clear();
1642   }
1643 
1644   // Enter the preprocessor block.
1645   Stream.EnterSubblock(PREPROCESSOR_BLOCK_ID, 3);
1646 
1647   // If the AST file contains __DATE__ or __TIME__ emit a warning about this.
1648   // FIXME: use diagnostics subsystem for localization etc.
1649   if (PP.SawDateOrTime())
1650     fprintf(stderr, "warning: precompiled header used __DATE__ or __TIME__.\n");
1651 
1652 
1653   // Loop over all the macro definitions that are live at the end of the file,
1654   // emitting each to the PP section.
1655 
1656   // Construct the list of macro definitions that need to be serialized.
1657   SmallVector<std::pair<const IdentifierInfo *, MacroInfo *>, 2>
1658     MacrosToEmit;
1659   llvm::SmallPtrSet<const IdentifierInfo*, 4> MacroDefinitionsSeen;
1660   for (Preprocessor::macro_iterator I = PP.macro_begin(Chain == 0),
1661                                     E = PP.macro_end(Chain == 0);
1662        I != E; ++I) {
1663     const IdentifierInfo *Name = I->first;
1664     if (!IsModule || I->second->isPublic()) {
1665       MacroDefinitionsSeen.insert(Name);
1666       MacrosToEmit.push_back(std::make_pair(I->first, I->second));
1667     }
1668   }
1669 
1670   // Sort the set of macro definitions that need to be serialized by the
1671   // name of the macro, to provide a stable ordering.
1672   llvm::array_pod_sort(MacrosToEmit.begin(), MacrosToEmit.end(),
1673                        &compareMacroDefinitions);
1674 
1675   // Resolve any identifiers that defined macros at the time they were
1676   // deserialized, adding them to the list of macros to emit (if appropriate).
1677   for (unsigned I = 0, N = DeserializedMacroNames.size(); I != N; ++I) {
1678     IdentifierInfo *Name
1679       = const_cast<IdentifierInfo *>(DeserializedMacroNames[I]);
1680     if (Name->hasMacroDefinition() && MacroDefinitionsSeen.insert(Name))
1681       MacrosToEmit.push_back(std::make_pair(Name, PP.getMacroInfo(Name)));
1682   }
1683 
1684   for (unsigned I = 0, N = MacrosToEmit.size(); I != N; ++I) {
1685     const IdentifierInfo *Name = MacrosToEmit[I].first;
1686     MacroInfo *MI = MacrosToEmit[I].second;
1687     if (!MI)
1688       continue;
1689 
1690     // Don't emit builtin macros like __LINE__ to the AST file unless they have
1691     // been redefined by the header (in which case they are not isBuiltinMacro).
1692     // Also skip macros from a AST file if we're chaining.
1693 
1694     // FIXME: There is a (probably minor) optimization we could do here, if
1695     // the macro comes from the original PCH but the identifier comes from a
1696     // chained PCH, by storing the offset into the original PCH rather than
1697     // writing the macro definition a second time.
1698     if (MI->isBuiltinMacro() ||
1699         (Chain &&
1700          Name->isFromAST() && !Name->hasChangedSinceDeserialization() &&
1701          MI->isFromAST() && !MI->hasChangedAfterLoad()))
1702       continue;
1703 
1704     AddIdentifierRef(Name, Record);
1705     MacroOffsets[Name] = Stream.GetCurrentBitNo();
1706     Record.push_back(MI->getDefinitionLoc().getRawEncoding());
1707     Record.push_back(MI->isUsed());
1708     Record.push_back(MI->isPublic());
1709     AddSourceLocation(MI->getVisibilityLocation(), Record);
1710     unsigned Code;
1711     if (MI->isObjectLike()) {
1712       Code = PP_MACRO_OBJECT_LIKE;
1713     } else {
1714       Code = PP_MACRO_FUNCTION_LIKE;
1715 
1716       Record.push_back(MI->isC99Varargs());
1717       Record.push_back(MI->isGNUVarargs());
1718       Record.push_back(MI->getNumArgs());
1719       for (MacroInfo::arg_iterator I = MI->arg_begin(), E = MI->arg_end();
1720            I != E; ++I)
1721         AddIdentifierRef(*I, Record);
1722     }
1723 
1724     // If we have a detailed preprocessing record, record the macro definition
1725     // ID that corresponds to this macro.
1726     if (PPRec)
1727       Record.push_back(MacroDefinitions[PPRec->findMacroDefinition(MI)]);
1728 
1729     Stream.EmitRecord(Code, Record);
1730     Record.clear();
1731 
1732     // Emit the tokens array.
1733     for (unsigned TokNo = 0, e = MI->getNumTokens(); TokNo != e; ++TokNo) {
1734       // Note that we know that the preprocessor does not have any annotation
1735       // tokens in it because they are created by the parser, and thus can't be
1736       // in a macro definition.
1737       const Token &Tok = MI->getReplacementToken(TokNo);
1738 
1739       Record.push_back(Tok.getLocation().getRawEncoding());
1740       Record.push_back(Tok.getLength());
1741 
1742       // FIXME: When reading literal tokens, reconstruct the literal pointer if
1743       // it is needed.
1744       AddIdentifierRef(Tok.getIdentifierInfo(), Record);
1745       // FIXME: Should translate token kind to a stable encoding.
1746       Record.push_back(Tok.getKind());
1747       // FIXME: Should translate token flags to a stable encoding.
1748       Record.push_back(Tok.getFlags());
1749 
1750       Stream.EmitRecord(PP_TOKEN, Record);
1751       Record.clear();
1752     }
1753     ++NumMacros;
1754   }
1755   Stream.ExitBlock();
1756 }
1757 
1758 void ASTWriter::WritePreprocessorDetail(PreprocessingRecord &PPRec) {
1759   if (PPRec.local_begin() == PPRec.local_end())
1760     return;
1761 
1762   SmallVector<PPEntityOffset, 64> PreprocessedEntityOffsets;
1763 
1764   // Enter the preprocessor block.
1765   Stream.EnterSubblock(PREPROCESSOR_DETAIL_BLOCK_ID, 3);
1766 
1767   // If the preprocessor has a preprocessing record, emit it.
1768   unsigned NumPreprocessingRecords = 0;
1769   using namespace llvm;
1770 
1771   // Set up the abbreviation for
1772   unsigned InclusionAbbrev = 0;
1773   {
1774     BitCodeAbbrev *Abbrev = new BitCodeAbbrev();
1775     Abbrev->Add(BitCodeAbbrevOp(PPD_INCLUSION_DIRECTIVE));
1776     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // filename length
1777     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // in quotes
1778     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2)); // kind
1779     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
1780     InclusionAbbrev = Stream.EmitAbbrev(Abbrev);
1781   }
1782 
1783   unsigned FirstPreprocessorEntityID
1784     = (Chain ? PPRec.getNumLoadedPreprocessedEntities() : 0)
1785     + NUM_PREDEF_PP_ENTITY_IDS;
1786   unsigned NextPreprocessorEntityID = FirstPreprocessorEntityID;
1787   RecordData Record;
1788   for (PreprocessingRecord::iterator E = PPRec.local_begin(),
1789                                   EEnd = PPRec.local_end();
1790        E != EEnd;
1791        (void)++E, ++NumPreprocessingRecords, ++NextPreprocessorEntityID) {
1792     Record.clear();
1793 
1794     PreprocessedEntityOffsets.push_back(PPEntityOffset((*E)->getSourceRange(),
1795                                                      Stream.GetCurrentBitNo()));
1796 
1797     if (MacroDefinition *MD = dyn_cast<MacroDefinition>(*E)) {
1798       // Record this macro definition's ID.
1799       MacroDefinitions[MD] = NextPreprocessorEntityID;
1800 
1801       AddIdentifierRef(MD->getName(), Record);
1802       Stream.EmitRecord(PPD_MACRO_DEFINITION, Record);
1803       continue;
1804     }
1805 
1806     if (MacroExpansion *ME = dyn_cast<MacroExpansion>(*E)) {
1807       Record.push_back(ME->isBuiltinMacro());
1808       if (ME->isBuiltinMacro())
1809         AddIdentifierRef(ME->getName(), Record);
1810       else
1811         Record.push_back(MacroDefinitions[ME->getDefinition()]);
1812       Stream.EmitRecord(PPD_MACRO_EXPANSION, Record);
1813       continue;
1814     }
1815 
1816     if (InclusionDirective *ID = dyn_cast<InclusionDirective>(*E)) {
1817       Record.push_back(PPD_INCLUSION_DIRECTIVE);
1818       Record.push_back(ID->getFileName().size());
1819       Record.push_back(ID->wasInQuotes());
1820       Record.push_back(static_cast<unsigned>(ID->getKind()));
1821       llvm::SmallString<64> Buffer;
1822       Buffer += ID->getFileName();
1823       Buffer += ID->getFile()->getName();
1824       Stream.EmitRecordWithBlob(InclusionAbbrev, Record, Buffer);
1825       continue;
1826     }
1827 
1828     llvm_unreachable("Unhandled PreprocessedEntity in ASTWriter");
1829   }
1830   Stream.ExitBlock();
1831 
1832   // Write the offsets table for the preprocessing record.
1833   if (NumPreprocessingRecords > 0) {
1834     assert(PreprocessedEntityOffsets.size() == NumPreprocessingRecords);
1835 
1836     // Write the offsets table for identifier IDs.
1837     using namespace llvm;
1838     BitCodeAbbrev *Abbrev = new BitCodeAbbrev();
1839     Abbrev->Add(BitCodeAbbrevOp(PPD_ENTITIES_OFFSETS));
1840     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // first pp entity
1841     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
1842     unsigned PPEOffsetAbbrev = Stream.EmitAbbrev(Abbrev);
1843 
1844     Record.clear();
1845     Record.push_back(PPD_ENTITIES_OFFSETS);
1846     Record.push_back(FirstPreprocessorEntityID - NUM_PREDEF_PP_ENTITY_IDS);
1847     Stream.EmitRecordWithBlob(PPEOffsetAbbrev, Record,
1848                               data(PreprocessedEntityOffsets));
1849   }
1850 }
1851 
1852 unsigned ASTWriter::getSubmoduleID(Module *Mod) {
1853   llvm::DenseMap<Module *, unsigned>::iterator Known = SubmoduleIDs.find(Mod);
1854   if (Known != SubmoduleIDs.end())
1855     return Known->second;
1856 
1857   return SubmoduleIDs[Mod] = NextSubmoduleID++;
1858 }
1859 
1860 /// \brief Compute the number of modules within the given tree (including the
1861 /// given module).
1862 static unsigned getNumberOfModules(Module *Mod) {
1863   unsigned ChildModules = 0;
1864   for (Module::submodule_iterator Sub = Mod->submodule_begin(),
1865                                SubEnd = Mod->submodule_end();
1866        Sub != SubEnd; ++Sub)
1867     ChildModules += getNumberOfModules(*Sub);
1868 
1869   return ChildModules + 1;
1870 }
1871 
1872 void ASTWriter::WriteSubmodules(Module *WritingModule) {
1873   // Determine the dependencies of our module and each of it's submodules.
1874   // FIXME: This feels like it belongs somewhere else, but there are no
1875   // other consumers of this information.
1876   SourceManager &SrcMgr = PP->getSourceManager();
1877   ModuleMap &ModMap = PP->getHeaderSearchInfo().getModuleMap();
1878   for (ASTContext::import_iterator I = Context->local_import_begin(),
1879                                 IEnd = Context->local_import_end();
1880        I != IEnd; ++I) {
1881     if (Module *ImportedFrom
1882           = ModMap.inferModuleFromLocation(FullSourceLoc(I->getLocation(),
1883                                                          SrcMgr))) {
1884       ImportedFrom->Imports.push_back(I->getImportedModule());
1885     }
1886   }
1887 
1888   // Enter the submodule description block.
1889   Stream.EnterSubblock(SUBMODULE_BLOCK_ID, NUM_ALLOWED_ABBREVS_SIZE);
1890 
1891   // Write the abbreviations needed for the submodules block.
1892   using namespace llvm;
1893   BitCodeAbbrev *Abbrev = new BitCodeAbbrev();
1894   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_DEFINITION));
1895   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // ID
1896   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Parent
1897   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsFramework
1898   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsExplicit
1899   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // InferExplicit...
1900   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsExplicit
1901   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // InferExportWild...
1902   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Name
1903   unsigned DefinitionAbbrev = Stream.EmitAbbrev(Abbrev);
1904 
1905   Abbrev = new BitCodeAbbrev();
1906   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_UMBRELLA_HEADER));
1907   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Name
1908   unsigned UmbrellaAbbrev = Stream.EmitAbbrev(Abbrev);
1909 
1910   Abbrev = new BitCodeAbbrev();
1911   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_HEADER));
1912   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Name
1913   unsigned HeaderAbbrev = Stream.EmitAbbrev(Abbrev);
1914 
1915   Abbrev = new BitCodeAbbrev();
1916   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_UMBRELLA_DIR));
1917   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Name
1918   unsigned UmbrellaDirAbbrev = Stream.EmitAbbrev(Abbrev);
1919 
1920   Abbrev = new BitCodeAbbrev();
1921   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_REQUIRES));
1922   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Feature
1923   unsigned RequiresAbbrev = Stream.EmitAbbrev(Abbrev);
1924 
1925   // Write the submodule metadata block.
1926   RecordData Record;
1927   Record.push_back(getNumberOfModules(WritingModule));
1928   Record.push_back(FirstSubmoduleID - NUM_PREDEF_SUBMODULE_IDS);
1929   Stream.EmitRecord(SUBMODULE_METADATA, Record);
1930 
1931   // Write all of the submodules.
1932   std::queue<Module *> Q;
1933   Q.push(WritingModule);
1934   while (!Q.empty()) {
1935     Module *Mod = Q.front();
1936     Q.pop();
1937     unsigned ID = getSubmoduleID(Mod);
1938 
1939     // Emit the definition of the block.
1940     Record.clear();
1941     Record.push_back(SUBMODULE_DEFINITION);
1942     Record.push_back(ID);
1943     if (Mod->Parent) {
1944       assert(SubmoduleIDs[Mod->Parent] && "Submodule parent not written?");
1945       Record.push_back(SubmoduleIDs[Mod->Parent]);
1946     } else {
1947       Record.push_back(0);
1948     }
1949     Record.push_back(Mod->IsFramework);
1950     Record.push_back(Mod->IsExplicit);
1951     Record.push_back(Mod->InferSubmodules);
1952     Record.push_back(Mod->InferExplicitSubmodules);
1953     Record.push_back(Mod->InferExportWildcard);
1954     Stream.EmitRecordWithBlob(DefinitionAbbrev, Record, Mod->Name);
1955 
1956     // Emit the requirements.
1957     for (unsigned I = 0, N = Mod->Requires.size(); I != N; ++I) {
1958       Record.clear();
1959       Record.push_back(SUBMODULE_REQUIRES);
1960       Stream.EmitRecordWithBlob(RequiresAbbrev, Record,
1961                                 Mod->Requires[I].data(),
1962                                 Mod->Requires[I].size());
1963     }
1964 
1965     // Emit the umbrella header, if there is one.
1966     if (const FileEntry *UmbrellaHeader = Mod->getUmbrellaHeader()) {
1967       Record.clear();
1968       Record.push_back(SUBMODULE_UMBRELLA_HEADER);
1969       Stream.EmitRecordWithBlob(UmbrellaAbbrev, Record,
1970                                 UmbrellaHeader->getName());
1971     } else if (const DirectoryEntry *UmbrellaDir = Mod->getUmbrellaDir()) {
1972       Record.clear();
1973       Record.push_back(SUBMODULE_UMBRELLA_DIR);
1974       Stream.EmitRecordWithBlob(UmbrellaDirAbbrev, Record,
1975                                 UmbrellaDir->getName());
1976     }
1977 
1978     // Emit the headers.
1979     for (unsigned I = 0, N = Mod->Headers.size(); I != N; ++I) {
1980       Record.clear();
1981       Record.push_back(SUBMODULE_HEADER);
1982       Stream.EmitRecordWithBlob(HeaderAbbrev, Record,
1983                                 Mod->Headers[I]->getName());
1984     }
1985 
1986     // Emit the imports.
1987     if (!Mod->Imports.empty()) {
1988       Record.clear();
1989       for (unsigned I = 0, N = Mod->Imports.size(); I != N; ++I) {
1990         unsigned ImportedID = getSubmoduleID(Mod->Imports[I]);
1991         assert(ImportedID && "Unknown submodule!");
1992         Record.push_back(ImportedID);
1993       }
1994       Stream.EmitRecord(SUBMODULE_IMPORTS, Record);
1995     }
1996 
1997     // Emit the exports.
1998     if (!Mod->Exports.empty()) {
1999       Record.clear();
2000       for (unsigned I = 0, N = Mod->Exports.size(); I != N; ++I) {
2001         if (Module *Exported = Mod->Exports[I].getPointer()) {
2002           unsigned ExportedID = SubmoduleIDs[Exported];
2003           assert(ExportedID > 0 && "Unknown submodule ID?");
2004           Record.push_back(ExportedID);
2005         } else {
2006           Record.push_back(0);
2007         }
2008 
2009         Record.push_back(Mod->Exports[I].getInt());
2010       }
2011       Stream.EmitRecord(SUBMODULE_EXPORTS, Record);
2012     }
2013 
2014     // Queue up the submodules of this module.
2015     for (Module::submodule_iterator Sub = Mod->submodule_begin(),
2016                                  SubEnd = Mod->submodule_end();
2017          Sub != SubEnd; ++Sub)
2018       Q.push(*Sub);
2019   }
2020 
2021   Stream.ExitBlock();
2022 
2023   assert((NextSubmoduleID - FirstSubmoduleID
2024             == getNumberOfModules(WritingModule)) && "Wrong # of submodules");
2025 }
2026 
2027 serialization::SubmoduleID
2028 ASTWriter::inferSubmoduleIDFromLocation(SourceLocation Loc) {
2029   if (Loc.isInvalid() || !WritingModule)
2030     return 0; // No submodule
2031 
2032   // Find the module that owns this location.
2033   ModuleMap &ModMap = PP->getHeaderSearchInfo().getModuleMap();
2034   Module *OwningMod
2035     = ModMap.inferModuleFromLocation(FullSourceLoc(Loc,PP->getSourceManager()));
2036   if (!OwningMod)
2037     return 0;
2038 
2039   // Check whether this submodule is part of our own module.
2040   if (WritingModule != OwningMod && !OwningMod->isSubModuleOf(WritingModule))
2041     return 0;
2042 
2043   return getSubmoduleID(OwningMod);
2044 }
2045 
2046 void ASTWriter::WritePragmaDiagnosticMappings(const DiagnosticsEngine &Diag) {
2047   RecordData Record;
2048   for (DiagnosticsEngine::DiagStatePointsTy::const_iterator
2049          I = Diag.DiagStatePoints.begin(), E = Diag.DiagStatePoints.end();
2050          I != E; ++I) {
2051     const DiagnosticsEngine::DiagStatePoint &point = *I;
2052     if (point.Loc.isInvalid())
2053       continue;
2054 
2055     Record.push_back(point.Loc.getRawEncoding());
2056     for (DiagnosticsEngine::DiagState::const_iterator
2057            I = point.State->begin(), E = point.State->end(); I != E; ++I) {
2058       if (I->second.isPragma()) {
2059         Record.push_back(I->first);
2060         Record.push_back(I->second.getMapping());
2061       }
2062     }
2063     Record.push_back(-1); // mark the end of the diag/map pairs for this
2064                           // location.
2065   }
2066 
2067   if (!Record.empty())
2068     Stream.EmitRecord(DIAG_PRAGMA_MAPPINGS, Record);
2069 }
2070 
2071 void ASTWriter::WriteCXXBaseSpecifiersOffsets() {
2072   if (CXXBaseSpecifiersOffsets.empty())
2073     return;
2074 
2075   RecordData Record;
2076 
2077   // Create a blob abbreviation for the C++ base specifiers offsets.
2078   using namespace llvm;
2079 
2080   BitCodeAbbrev *Abbrev = new BitCodeAbbrev();
2081   Abbrev->Add(BitCodeAbbrevOp(CXX_BASE_SPECIFIER_OFFSETS));
2082   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // size
2083   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
2084   unsigned BaseSpecifierOffsetAbbrev = Stream.EmitAbbrev(Abbrev);
2085 
2086   // Write the base specifier offsets table.
2087   Record.clear();
2088   Record.push_back(CXX_BASE_SPECIFIER_OFFSETS);
2089   Record.push_back(CXXBaseSpecifiersOffsets.size());
2090   Stream.EmitRecordWithBlob(BaseSpecifierOffsetAbbrev, Record,
2091                             data(CXXBaseSpecifiersOffsets));
2092 }
2093 
2094 //===----------------------------------------------------------------------===//
2095 // Type Serialization
2096 //===----------------------------------------------------------------------===//
2097 
2098 /// \brief Write the representation of a type to the AST stream.
2099 void ASTWriter::WriteType(QualType T) {
2100   TypeIdx &Idx = TypeIdxs[T];
2101   if (Idx.getIndex() == 0) // we haven't seen this type before.
2102     Idx = TypeIdx(NextTypeID++);
2103 
2104   assert(Idx.getIndex() >= FirstTypeID && "Re-writing a type from a prior AST");
2105 
2106   // Record the offset for this type.
2107   unsigned Index = Idx.getIndex() - FirstTypeID;
2108   if (TypeOffsets.size() == Index)
2109     TypeOffsets.push_back(Stream.GetCurrentBitNo());
2110   else if (TypeOffsets.size() < Index) {
2111     TypeOffsets.resize(Index + 1);
2112     TypeOffsets[Index] = Stream.GetCurrentBitNo();
2113   }
2114 
2115   RecordData Record;
2116 
2117   // Emit the type's representation.
2118   ASTTypeWriter W(*this, Record);
2119 
2120   if (T.hasLocalNonFastQualifiers()) {
2121     Qualifiers Qs = T.getLocalQualifiers();
2122     AddTypeRef(T.getLocalUnqualifiedType(), Record);
2123     Record.push_back(Qs.getAsOpaqueValue());
2124     W.Code = TYPE_EXT_QUAL;
2125   } else {
2126     switch (T->getTypeClass()) {
2127       // For all of the concrete, non-dependent types, call the
2128       // appropriate visitor function.
2129 #define TYPE(Class, Base) \
2130     case Type::Class: W.Visit##Class##Type(cast<Class##Type>(T)); break;
2131 #define ABSTRACT_TYPE(Class, Base)
2132 #include "clang/AST/TypeNodes.def"
2133     }
2134   }
2135 
2136   // Emit the serialized record.
2137   Stream.EmitRecord(W.Code, Record);
2138 
2139   // Flush any expressions that were written as part of this type.
2140   FlushStmts();
2141 }
2142 
2143 //===----------------------------------------------------------------------===//
2144 // Declaration Serialization
2145 //===----------------------------------------------------------------------===//
2146 
2147 /// \brief Write the block containing all of the declaration IDs
2148 /// lexically declared within the given DeclContext.
2149 ///
2150 /// \returns the offset of the DECL_CONTEXT_LEXICAL block within the
2151 /// bistream, or 0 if no block was written.
2152 uint64_t ASTWriter::WriteDeclContextLexicalBlock(ASTContext &Context,
2153                                                  DeclContext *DC) {
2154   if (DC->decls_empty())
2155     return 0;
2156 
2157   uint64_t Offset = Stream.GetCurrentBitNo();
2158   RecordData Record;
2159   Record.push_back(DECL_CONTEXT_LEXICAL);
2160   SmallVector<KindDeclIDPair, 64> Decls;
2161   for (DeclContext::decl_iterator D = DC->decls_begin(), DEnd = DC->decls_end();
2162          D != DEnd; ++D)
2163     Decls.push_back(std::make_pair((*D)->getKind(), GetDeclRef(*D)));
2164 
2165   ++NumLexicalDeclContexts;
2166   Stream.EmitRecordWithBlob(DeclContextLexicalAbbrev, Record, data(Decls));
2167   return Offset;
2168 }
2169 
2170 void ASTWriter::WriteTypeDeclOffsets() {
2171   using namespace llvm;
2172   RecordData Record;
2173 
2174   // Write the type offsets array
2175   BitCodeAbbrev *Abbrev = new BitCodeAbbrev();
2176   Abbrev->Add(BitCodeAbbrevOp(TYPE_OFFSET));
2177   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // # of types
2178   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // base type index
2179   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // types block
2180   unsigned TypeOffsetAbbrev = Stream.EmitAbbrev(Abbrev);
2181   Record.clear();
2182   Record.push_back(TYPE_OFFSET);
2183   Record.push_back(TypeOffsets.size());
2184   Record.push_back(FirstTypeID - NUM_PREDEF_TYPE_IDS);
2185   Stream.EmitRecordWithBlob(TypeOffsetAbbrev, Record, data(TypeOffsets));
2186 
2187   // Write the declaration offsets array
2188   Abbrev = new BitCodeAbbrev();
2189   Abbrev->Add(BitCodeAbbrevOp(DECL_OFFSET));
2190   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // # of declarations
2191   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // base decl ID
2192   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // declarations block
2193   unsigned DeclOffsetAbbrev = Stream.EmitAbbrev(Abbrev);
2194   Record.clear();
2195   Record.push_back(DECL_OFFSET);
2196   Record.push_back(DeclOffsets.size());
2197   Record.push_back(FirstDeclID - NUM_PREDEF_DECL_IDS);
2198   Stream.EmitRecordWithBlob(DeclOffsetAbbrev, Record, data(DeclOffsets));
2199 }
2200 
2201 void ASTWriter::WriteFileDeclIDsMap() {
2202   using namespace llvm;
2203   RecordData Record;
2204 
2205   // Join the vectors of DeclIDs from all files.
2206   SmallVector<DeclID, 256> FileSortedIDs;
2207   for (FileDeclIDsTy::iterator
2208          FI = FileDeclIDs.begin(), FE = FileDeclIDs.end(); FI != FE; ++FI) {
2209     DeclIDInFileInfo &Info = *FI->second;
2210     Info.FirstDeclIndex = FileSortedIDs.size();
2211     for (LocDeclIDsTy::iterator
2212            DI = Info.DeclIDs.begin(), DE = Info.DeclIDs.end(); DI != DE; ++DI)
2213       FileSortedIDs.push_back(DI->second);
2214   }
2215 
2216   BitCodeAbbrev *Abbrev = new BitCodeAbbrev();
2217   Abbrev->Add(BitCodeAbbrevOp(FILE_SORTED_DECLS));
2218   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
2219   unsigned AbbrevCode = Stream.EmitAbbrev(Abbrev);
2220   Record.push_back(FILE_SORTED_DECLS);
2221   Stream.EmitRecordWithBlob(AbbrevCode, Record, data(FileSortedIDs));
2222 }
2223 
2224 //===----------------------------------------------------------------------===//
2225 // Global Method Pool and Selector Serialization
2226 //===----------------------------------------------------------------------===//
2227 
2228 namespace {
2229 // Trait used for the on-disk hash table used in the method pool.
2230 class ASTMethodPoolTrait {
2231   ASTWriter &Writer;
2232 
2233 public:
2234   typedef Selector key_type;
2235   typedef key_type key_type_ref;
2236 
2237   struct data_type {
2238     SelectorID ID;
2239     ObjCMethodList Instance, Factory;
2240   };
2241   typedef const data_type& data_type_ref;
2242 
2243   explicit ASTMethodPoolTrait(ASTWriter &Writer) : Writer(Writer) { }
2244 
2245   static unsigned ComputeHash(Selector Sel) {
2246     return serialization::ComputeHash(Sel);
2247   }
2248 
2249   std::pair<unsigned,unsigned>
2250     EmitKeyDataLength(raw_ostream& Out, Selector Sel,
2251                       data_type_ref Methods) {
2252     unsigned KeyLen = 2 + (Sel.getNumArgs()? Sel.getNumArgs() * 4 : 4);
2253     clang::io::Emit16(Out, KeyLen);
2254     unsigned DataLen = 4 + 2 + 2; // 2 bytes for each of the method counts
2255     for (const ObjCMethodList *Method = &Methods.Instance; Method;
2256          Method = Method->Next)
2257       if (Method->Method)
2258         DataLen += 4;
2259     for (const ObjCMethodList *Method = &Methods.Factory; Method;
2260          Method = Method->Next)
2261       if (Method->Method)
2262         DataLen += 4;
2263     clang::io::Emit16(Out, DataLen);
2264     return std::make_pair(KeyLen, DataLen);
2265   }
2266 
2267   void EmitKey(raw_ostream& Out, Selector Sel, unsigned) {
2268     uint64_t Start = Out.tell();
2269     assert((Start >> 32) == 0 && "Selector key offset too large");
2270     Writer.SetSelectorOffset(Sel, Start);
2271     unsigned N = Sel.getNumArgs();
2272     clang::io::Emit16(Out, N);
2273     if (N == 0)
2274       N = 1;
2275     for (unsigned I = 0; I != N; ++I)
2276       clang::io::Emit32(Out,
2277                     Writer.getIdentifierRef(Sel.getIdentifierInfoForSlot(I)));
2278   }
2279 
2280   void EmitData(raw_ostream& Out, key_type_ref,
2281                 data_type_ref Methods, unsigned DataLen) {
2282     uint64_t Start = Out.tell(); (void)Start;
2283     clang::io::Emit32(Out, Methods.ID);
2284     unsigned NumInstanceMethods = 0;
2285     for (const ObjCMethodList *Method = &Methods.Instance; Method;
2286          Method = Method->Next)
2287       if (Method->Method)
2288         ++NumInstanceMethods;
2289 
2290     unsigned NumFactoryMethods = 0;
2291     for (const ObjCMethodList *Method = &Methods.Factory; Method;
2292          Method = Method->Next)
2293       if (Method->Method)
2294         ++NumFactoryMethods;
2295 
2296     clang::io::Emit16(Out, NumInstanceMethods);
2297     clang::io::Emit16(Out, NumFactoryMethods);
2298     for (const ObjCMethodList *Method = &Methods.Instance; Method;
2299          Method = Method->Next)
2300       if (Method->Method)
2301         clang::io::Emit32(Out, Writer.getDeclID(Method->Method));
2302     for (const ObjCMethodList *Method = &Methods.Factory; Method;
2303          Method = Method->Next)
2304       if (Method->Method)
2305         clang::io::Emit32(Out, Writer.getDeclID(Method->Method));
2306 
2307     assert(Out.tell() - Start == DataLen && "Data length is wrong");
2308   }
2309 };
2310 } // end anonymous namespace
2311 
2312 /// \brief Write ObjC data: selectors and the method pool.
2313 ///
2314 /// The method pool contains both instance and factory methods, stored
2315 /// in an on-disk hash table indexed by the selector. The hash table also
2316 /// contains an empty entry for every other selector known to Sema.
2317 void ASTWriter::WriteSelectors(Sema &SemaRef) {
2318   using namespace llvm;
2319 
2320   // Do we have to do anything at all?
2321   if (SemaRef.MethodPool.empty() && SelectorIDs.empty())
2322     return;
2323   unsigned NumTableEntries = 0;
2324   // Create and write out the blob that contains selectors and the method pool.
2325   {
2326     OnDiskChainedHashTableGenerator<ASTMethodPoolTrait> Generator;
2327     ASTMethodPoolTrait Trait(*this);
2328 
2329     // Create the on-disk hash table representation. We walk through every
2330     // selector we've seen and look it up in the method pool.
2331     SelectorOffsets.resize(NextSelectorID - FirstSelectorID);
2332     for (llvm::DenseMap<Selector, SelectorID>::iterator
2333              I = SelectorIDs.begin(), E = SelectorIDs.end();
2334          I != E; ++I) {
2335       Selector S = I->first;
2336       Sema::GlobalMethodPool::iterator F = SemaRef.MethodPool.find(S);
2337       ASTMethodPoolTrait::data_type Data = {
2338         I->second,
2339         ObjCMethodList(),
2340         ObjCMethodList()
2341       };
2342       if (F != SemaRef.MethodPool.end()) {
2343         Data.Instance = F->second.first;
2344         Data.Factory = F->second.second;
2345       }
2346       // Only write this selector if it's not in an existing AST or something
2347       // changed.
2348       if (Chain && I->second < FirstSelectorID) {
2349         // Selector already exists. Did it change?
2350         bool changed = false;
2351         for (ObjCMethodList *M = &Data.Instance; !changed && M && M->Method;
2352              M = M->Next) {
2353           if (!M->Method->isFromASTFile())
2354             changed = true;
2355         }
2356         for (ObjCMethodList *M = &Data.Factory; !changed && M && M->Method;
2357              M = M->Next) {
2358           if (!M->Method->isFromASTFile())
2359             changed = true;
2360         }
2361         if (!changed)
2362           continue;
2363       } else if (Data.Instance.Method || Data.Factory.Method) {
2364         // A new method pool entry.
2365         ++NumTableEntries;
2366       }
2367       Generator.insert(S, Data, Trait);
2368     }
2369 
2370     // Create the on-disk hash table in a buffer.
2371     llvm::SmallString<4096> MethodPool;
2372     uint32_t BucketOffset;
2373     {
2374       ASTMethodPoolTrait Trait(*this);
2375       llvm::raw_svector_ostream Out(MethodPool);
2376       // Make sure that no bucket is at offset 0
2377       clang::io::Emit32(Out, 0);
2378       BucketOffset = Generator.Emit(Out, Trait);
2379     }
2380 
2381     // Create a blob abbreviation
2382     BitCodeAbbrev *Abbrev = new BitCodeAbbrev();
2383     Abbrev->Add(BitCodeAbbrevOp(METHOD_POOL));
2384     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
2385     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
2386     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
2387     unsigned MethodPoolAbbrev = Stream.EmitAbbrev(Abbrev);
2388 
2389     // Write the method pool
2390     RecordData Record;
2391     Record.push_back(METHOD_POOL);
2392     Record.push_back(BucketOffset);
2393     Record.push_back(NumTableEntries);
2394     Stream.EmitRecordWithBlob(MethodPoolAbbrev, Record, MethodPool.str());
2395 
2396     // Create a blob abbreviation for the selector table offsets.
2397     Abbrev = new BitCodeAbbrev();
2398     Abbrev->Add(BitCodeAbbrevOp(SELECTOR_OFFSETS));
2399     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // size
2400     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // first ID
2401     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
2402     unsigned SelectorOffsetAbbrev = Stream.EmitAbbrev(Abbrev);
2403 
2404     // Write the selector offsets table.
2405     Record.clear();
2406     Record.push_back(SELECTOR_OFFSETS);
2407     Record.push_back(SelectorOffsets.size());
2408     Record.push_back(FirstSelectorID - NUM_PREDEF_SELECTOR_IDS);
2409     Stream.EmitRecordWithBlob(SelectorOffsetAbbrev, Record,
2410                               data(SelectorOffsets));
2411   }
2412 }
2413 
2414 /// \brief Write the selectors referenced in @selector expression into AST file.
2415 void ASTWriter::WriteReferencedSelectorsPool(Sema &SemaRef) {
2416   using namespace llvm;
2417   if (SemaRef.ReferencedSelectors.empty())
2418     return;
2419 
2420   RecordData Record;
2421 
2422   // Note: this writes out all references even for a dependent AST. But it is
2423   // very tricky to fix, and given that @selector shouldn't really appear in
2424   // headers, probably not worth it. It's not a correctness issue.
2425   for (DenseMap<Selector, SourceLocation>::iterator S =
2426        SemaRef.ReferencedSelectors.begin(),
2427        E = SemaRef.ReferencedSelectors.end(); S != E; ++S) {
2428     Selector Sel = (*S).first;
2429     SourceLocation Loc = (*S).second;
2430     AddSelectorRef(Sel, Record);
2431     AddSourceLocation(Loc, Record);
2432   }
2433   Stream.EmitRecord(REFERENCED_SELECTOR_POOL, Record);
2434 }
2435 
2436 //===----------------------------------------------------------------------===//
2437 // Identifier Table Serialization
2438 //===----------------------------------------------------------------------===//
2439 
2440 namespace {
2441 class ASTIdentifierTableTrait {
2442   ASTWriter &Writer;
2443   Preprocessor &PP;
2444   IdentifierResolver &IdResolver;
2445   bool IsModule;
2446 
2447   /// \brief Determines whether this is an "interesting" identifier
2448   /// that needs a full IdentifierInfo structure written into the hash
2449   /// table.
2450   bool isInterestingIdentifier(IdentifierInfo *II, MacroInfo *&Macro) {
2451     if (II->isPoisoned() ||
2452         II->isExtensionToken() ||
2453         II->getObjCOrBuiltinID() ||
2454         II->hasRevertedTokenIDToIdentifier() ||
2455         II->getFETokenInfo<void>())
2456       return true;
2457 
2458     return hasMacroDefinition(II, Macro);
2459   }
2460 
2461   bool hasMacroDefinition(IdentifierInfo *II, MacroInfo *&Macro) {
2462     if (!II->hasMacroDefinition())
2463       return false;
2464 
2465     if (Macro || (Macro = PP.getMacroInfo(II)))
2466       return !Macro->isBuiltinMacro() && (!IsModule || Macro->isPublic());
2467 
2468     return false;
2469   }
2470 
2471 public:
2472   typedef IdentifierInfo* key_type;
2473   typedef key_type  key_type_ref;
2474 
2475   typedef IdentID data_type;
2476   typedef data_type data_type_ref;
2477 
2478   ASTIdentifierTableTrait(ASTWriter &Writer, Preprocessor &PP,
2479                           IdentifierResolver &IdResolver, bool IsModule)
2480     : Writer(Writer), PP(PP), IdResolver(IdResolver), IsModule(IsModule) { }
2481 
2482   static unsigned ComputeHash(const IdentifierInfo* II) {
2483     return llvm::HashString(II->getName());
2484   }
2485 
2486   std::pair<unsigned,unsigned>
2487   EmitKeyDataLength(raw_ostream& Out, IdentifierInfo* II, IdentID ID) {
2488     unsigned KeyLen = II->getLength() + 1;
2489     unsigned DataLen = 4; // 4 bytes for the persistent ID << 1
2490     MacroInfo *Macro = 0;
2491     if (isInterestingIdentifier(II, Macro)) {
2492       DataLen += 2; // 2 bytes for builtin ID, flags
2493       if (hasMacroDefinition(II, Macro))
2494         DataLen += 8;
2495 
2496       for (IdentifierResolver::iterator D = IdResolver.begin(II),
2497                                      DEnd = IdResolver.end();
2498            D != DEnd; ++D)
2499         DataLen += sizeof(DeclID);
2500     }
2501     clang::io::Emit16(Out, DataLen);
2502     // We emit the key length after the data length so that every
2503     // string is preceded by a 16-bit length. This matches the PTH
2504     // format for storing identifiers.
2505     clang::io::Emit16(Out, KeyLen);
2506     return std::make_pair(KeyLen, DataLen);
2507   }
2508 
2509   void EmitKey(raw_ostream& Out, const IdentifierInfo* II,
2510                unsigned KeyLen) {
2511     // Record the location of the key data.  This is used when generating
2512     // the mapping from persistent IDs to strings.
2513     Writer.SetIdentifierOffset(II, Out.tell());
2514     Out.write(II->getNameStart(), KeyLen);
2515   }
2516 
2517   void EmitData(raw_ostream& Out, IdentifierInfo* II,
2518                 IdentID ID, unsigned) {
2519     MacroInfo *Macro = 0;
2520     if (!isInterestingIdentifier(II, Macro)) {
2521       clang::io::Emit32(Out, ID << 1);
2522       return;
2523     }
2524 
2525     clang::io::Emit32(Out, (ID << 1) | 0x01);
2526     uint32_t Bits = 0;
2527     bool HasMacroDefinition = hasMacroDefinition(II, Macro);
2528     Bits = (uint32_t)II->getObjCOrBuiltinID();
2529     assert((Bits & 0x7ff) == Bits && "ObjCOrBuiltinID too big for ASTReader.");
2530     Bits = (Bits << 1) | unsigned(HasMacroDefinition);
2531     Bits = (Bits << 1) | unsigned(II->isExtensionToken());
2532     Bits = (Bits << 1) | unsigned(II->isPoisoned());
2533     Bits = (Bits << 1) | unsigned(II->hasRevertedTokenIDToIdentifier());
2534     Bits = (Bits << 1) | unsigned(II->isCPlusPlusOperatorKeyword());
2535     clang::io::Emit16(Out, Bits);
2536 
2537     if (HasMacroDefinition) {
2538       clang::io::Emit32(Out, Writer.getMacroOffset(II));
2539       clang::io::Emit32(Out,
2540         Writer.inferSubmoduleIDFromLocation(Macro->getDefinitionLoc()));
2541     }
2542 
2543     // Emit the declaration IDs in reverse order, because the
2544     // IdentifierResolver provides the declarations as they would be
2545     // visible (e.g., the function "stat" would come before the struct
2546     // "stat"), but the ASTReader adds declarations to the end of the list
2547     // (so we need to see the struct "status" before the function "status").
2548     // Only emit declarations that aren't from a chained PCH, though.
2549     SmallVector<Decl *, 16> Decls(IdResolver.begin(II),
2550                                   IdResolver.end());
2551     for (SmallVector<Decl *, 16>::reverse_iterator D = Decls.rbegin(),
2552                                                 DEnd = Decls.rend();
2553          D != DEnd; ++D)
2554       clang::io::Emit32(Out, Writer.getDeclID(*D));
2555   }
2556 };
2557 } // end anonymous namespace
2558 
2559 /// \brief Write the identifier table into the AST file.
2560 ///
2561 /// The identifier table consists of a blob containing string data
2562 /// (the actual identifiers themselves) and a separate "offsets" index
2563 /// that maps identifier IDs to locations within the blob.
2564 void ASTWriter::WriteIdentifierTable(Preprocessor &PP,
2565                                      IdentifierResolver &IdResolver,
2566                                      bool IsModule) {
2567   using namespace llvm;
2568 
2569   // Create and write out the blob that contains the identifier
2570   // strings.
2571   {
2572     OnDiskChainedHashTableGenerator<ASTIdentifierTableTrait> Generator;
2573     ASTIdentifierTableTrait Trait(*this, PP, IdResolver, IsModule);
2574 
2575     // Look for any identifiers that were named while processing the
2576     // headers, but are otherwise not needed. We add these to the hash
2577     // table to enable checking of the predefines buffer in the case
2578     // where the user adds new macro definitions when building the AST
2579     // file.
2580     for (IdentifierTable::iterator ID = PP.getIdentifierTable().begin(),
2581                                 IDEnd = PP.getIdentifierTable().end();
2582          ID != IDEnd; ++ID)
2583       getIdentifierRef(ID->second);
2584 
2585     // Create the on-disk hash table representation. We only store offsets
2586     // for identifiers that appear here for the first time.
2587     IdentifierOffsets.resize(NextIdentID - FirstIdentID);
2588     for (llvm::DenseMap<const IdentifierInfo *, IdentID>::iterator
2589            ID = IdentifierIDs.begin(), IDEnd = IdentifierIDs.end();
2590          ID != IDEnd; ++ID) {
2591       assert(ID->first && "NULL identifier in identifier table");
2592       if (!Chain || !ID->first->isFromAST() ||
2593           ID->first->hasChangedSinceDeserialization())
2594         Generator.insert(const_cast<IdentifierInfo *>(ID->first), ID->second,
2595                          Trait);
2596     }
2597 
2598     // Create the on-disk hash table in a buffer.
2599     llvm::SmallString<4096> IdentifierTable;
2600     uint32_t BucketOffset;
2601     {
2602       ASTIdentifierTableTrait Trait(*this, PP, IdResolver, IsModule);
2603       llvm::raw_svector_ostream Out(IdentifierTable);
2604       // Make sure that no bucket is at offset 0
2605       clang::io::Emit32(Out, 0);
2606       BucketOffset = Generator.Emit(Out, Trait);
2607     }
2608 
2609     // Create a blob abbreviation
2610     BitCodeAbbrev *Abbrev = new BitCodeAbbrev();
2611     Abbrev->Add(BitCodeAbbrevOp(IDENTIFIER_TABLE));
2612     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
2613     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
2614     unsigned IDTableAbbrev = Stream.EmitAbbrev(Abbrev);
2615 
2616     // Write the identifier table
2617     RecordData Record;
2618     Record.push_back(IDENTIFIER_TABLE);
2619     Record.push_back(BucketOffset);
2620     Stream.EmitRecordWithBlob(IDTableAbbrev, Record, IdentifierTable.str());
2621   }
2622 
2623   // Write the offsets table for identifier IDs.
2624   BitCodeAbbrev *Abbrev = new BitCodeAbbrev();
2625   Abbrev->Add(BitCodeAbbrevOp(IDENTIFIER_OFFSET));
2626   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // # of identifiers
2627   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // first ID
2628   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
2629   unsigned IdentifierOffsetAbbrev = Stream.EmitAbbrev(Abbrev);
2630 
2631   RecordData Record;
2632   Record.push_back(IDENTIFIER_OFFSET);
2633   Record.push_back(IdentifierOffsets.size());
2634   Record.push_back(FirstIdentID - NUM_PREDEF_IDENT_IDS);
2635   Stream.EmitRecordWithBlob(IdentifierOffsetAbbrev, Record,
2636                             data(IdentifierOffsets));
2637 }
2638 
2639 //===----------------------------------------------------------------------===//
2640 // DeclContext's Name Lookup Table Serialization
2641 //===----------------------------------------------------------------------===//
2642 
2643 namespace {
2644 // Trait used for the on-disk hash table used in the method pool.
2645 class ASTDeclContextNameLookupTrait {
2646   ASTWriter &Writer;
2647 
2648 public:
2649   typedef DeclarationName key_type;
2650   typedef key_type key_type_ref;
2651 
2652   typedef DeclContext::lookup_result data_type;
2653   typedef const data_type& data_type_ref;
2654 
2655   explicit ASTDeclContextNameLookupTrait(ASTWriter &Writer) : Writer(Writer) { }
2656 
2657   unsigned ComputeHash(DeclarationName Name) {
2658     llvm::FoldingSetNodeID ID;
2659     ID.AddInteger(Name.getNameKind());
2660 
2661     switch (Name.getNameKind()) {
2662     case DeclarationName::Identifier:
2663       ID.AddString(Name.getAsIdentifierInfo()->getName());
2664       break;
2665     case DeclarationName::ObjCZeroArgSelector:
2666     case DeclarationName::ObjCOneArgSelector:
2667     case DeclarationName::ObjCMultiArgSelector:
2668       ID.AddInteger(serialization::ComputeHash(Name.getObjCSelector()));
2669       break;
2670     case DeclarationName::CXXConstructorName:
2671     case DeclarationName::CXXDestructorName:
2672     case DeclarationName::CXXConversionFunctionName:
2673       break;
2674     case DeclarationName::CXXOperatorName:
2675       ID.AddInteger(Name.getCXXOverloadedOperator());
2676       break;
2677     case DeclarationName::CXXLiteralOperatorName:
2678       ID.AddString(Name.getCXXLiteralIdentifier()->getName());
2679     case DeclarationName::CXXUsingDirective:
2680       break;
2681     }
2682 
2683     return ID.ComputeHash();
2684   }
2685 
2686   std::pair<unsigned,unsigned>
2687     EmitKeyDataLength(raw_ostream& Out, DeclarationName Name,
2688                       data_type_ref Lookup) {
2689     unsigned KeyLen = 1;
2690     switch (Name.getNameKind()) {
2691     case DeclarationName::Identifier:
2692     case DeclarationName::ObjCZeroArgSelector:
2693     case DeclarationName::ObjCOneArgSelector:
2694     case DeclarationName::ObjCMultiArgSelector:
2695     case DeclarationName::CXXLiteralOperatorName:
2696       KeyLen += 4;
2697       break;
2698     case DeclarationName::CXXOperatorName:
2699       KeyLen += 1;
2700       break;
2701     case DeclarationName::CXXConstructorName:
2702     case DeclarationName::CXXDestructorName:
2703     case DeclarationName::CXXConversionFunctionName:
2704     case DeclarationName::CXXUsingDirective:
2705       break;
2706     }
2707     clang::io::Emit16(Out, KeyLen);
2708 
2709     // 2 bytes for num of decls and 4 for each DeclID.
2710     unsigned DataLen = 2 + 4 * (Lookup.second - Lookup.first);
2711     clang::io::Emit16(Out, DataLen);
2712 
2713     return std::make_pair(KeyLen, DataLen);
2714   }
2715 
2716   void EmitKey(raw_ostream& Out, DeclarationName Name, unsigned) {
2717     using namespace clang::io;
2718 
2719     assert(Name.getNameKind() < 0x100 && "Invalid name kind ?");
2720     Emit8(Out, Name.getNameKind());
2721     switch (Name.getNameKind()) {
2722     case DeclarationName::Identifier:
2723       Emit32(Out, Writer.getIdentifierRef(Name.getAsIdentifierInfo()));
2724       break;
2725     case DeclarationName::ObjCZeroArgSelector:
2726     case DeclarationName::ObjCOneArgSelector:
2727     case DeclarationName::ObjCMultiArgSelector:
2728       Emit32(Out, Writer.getSelectorRef(Name.getObjCSelector()));
2729       break;
2730     case DeclarationName::CXXOperatorName:
2731       assert(Name.getCXXOverloadedOperator() < 0x100 && "Invalid operator ?");
2732       Emit8(Out, Name.getCXXOverloadedOperator());
2733       break;
2734     case DeclarationName::CXXLiteralOperatorName:
2735       Emit32(Out, Writer.getIdentifierRef(Name.getCXXLiteralIdentifier()));
2736       break;
2737     case DeclarationName::CXXConstructorName:
2738     case DeclarationName::CXXDestructorName:
2739     case DeclarationName::CXXConversionFunctionName:
2740     case DeclarationName::CXXUsingDirective:
2741       break;
2742     }
2743   }
2744 
2745   void EmitData(raw_ostream& Out, key_type_ref,
2746                 data_type Lookup, unsigned DataLen) {
2747     uint64_t Start = Out.tell(); (void)Start;
2748     clang::io::Emit16(Out, Lookup.second - Lookup.first);
2749     for (; Lookup.first != Lookup.second; ++Lookup.first)
2750       clang::io::Emit32(Out, Writer.GetDeclRef(*Lookup.first));
2751 
2752     assert(Out.tell() - Start == DataLen && "Data length is wrong");
2753   }
2754 };
2755 } // end anonymous namespace
2756 
2757 /// \brief Write the block containing all of the declaration IDs
2758 /// visible from the given DeclContext.
2759 ///
2760 /// \returns the offset of the DECL_CONTEXT_VISIBLE block within the
2761 /// bitstream, or 0 if no block was written.
2762 uint64_t ASTWriter::WriteDeclContextVisibleBlock(ASTContext &Context,
2763                                                  DeclContext *DC) {
2764   if (DC->getPrimaryContext() != DC)
2765     return 0;
2766 
2767   // Since there is no name lookup into functions or methods, don't bother to
2768   // build a visible-declarations table for these entities.
2769   if (DC->isFunctionOrMethod())
2770     return 0;
2771 
2772   // If not in C++, we perform name lookup for the translation unit via the
2773   // IdentifierInfo chains, don't bother to build a visible-declarations table.
2774   // FIXME: In C++ we need the visible declarations in order to "see" the
2775   // friend declarations, is there a way to do this without writing the table ?
2776   if (DC->isTranslationUnit() && !Context.getLangOptions().CPlusPlus)
2777     return 0;
2778 
2779   // Force the DeclContext to build a its name-lookup table.
2780   if (!DC->hasExternalVisibleStorage())
2781     DC->lookup(DeclarationName());
2782 
2783   // Serialize the contents of the mapping used for lookup. Note that,
2784   // although we have two very different code paths, the serialized
2785   // representation is the same for both cases: a declaration name,
2786   // followed by a size, followed by references to the visible
2787   // declarations that have that name.
2788   uint64_t Offset = Stream.GetCurrentBitNo();
2789   StoredDeclsMap *Map = static_cast<StoredDeclsMap*>(DC->getLookupPtr());
2790   if (!Map || Map->empty())
2791     return 0;
2792 
2793   OnDiskChainedHashTableGenerator<ASTDeclContextNameLookupTrait> Generator;
2794   ASTDeclContextNameLookupTrait Trait(*this);
2795 
2796   // Create the on-disk hash table representation.
2797   DeclarationName ConversionName;
2798   llvm::SmallVector<NamedDecl *, 4> ConversionDecls;
2799   for (StoredDeclsMap::iterator D = Map->begin(), DEnd = Map->end();
2800        D != DEnd; ++D) {
2801     DeclarationName Name = D->first;
2802     DeclContext::lookup_result Result = D->second.getLookupResult();
2803     if (Result.first != Result.second) {
2804       if (Name.getNameKind() == DeclarationName::CXXConversionFunctionName) {
2805         // Hash all conversion function names to the same name. The actual
2806         // type information in conversion function name is not used in the
2807         // key (since such type information is not stable across different
2808         // modules), so the intended effect is to coalesce all of the conversion
2809         // functions under a single key.
2810         if (!ConversionName)
2811           ConversionName = Name;
2812         ConversionDecls.append(Result.first, Result.second);
2813         continue;
2814       }
2815 
2816       Generator.insert(Name, Result, Trait);
2817     }
2818   }
2819 
2820   // Add the conversion functions
2821   if (!ConversionDecls.empty()) {
2822     Generator.insert(ConversionName,
2823                      DeclContext::lookup_result(ConversionDecls.begin(),
2824                                                 ConversionDecls.end()),
2825                      Trait);
2826   }
2827 
2828   // Create the on-disk hash table in a buffer.
2829   llvm::SmallString<4096> LookupTable;
2830   uint32_t BucketOffset;
2831   {
2832     llvm::raw_svector_ostream Out(LookupTable);
2833     // Make sure that no bucket is at offset 0
2834     clang::io::Emit32(Out, 0);
2835     BucketOffset = Generator.Emit(Out, Trait);
2836   }
2837 
2838   // Write the lookup table
2839   RecordData Record;
2840   Record.push_back(DECL_CONTEXT_VISIBLE);
2841   Record.push_back(BucketOffset);
2842   Stream.EmitRecordWithBlob(DeclContextVisibleLookupAbbrev, Record,
2843                             LookupTable.str());
2844 
2845   Stream.EmitRecord(DECL_CONTEXT_VISIBLE, Record);
2846   ++NumVisibleDeclContexts;
2847   return Offset;
2848 }
2849 
2850 /// \brief Write an UPDATE_VISIBLE block for the given context.
2851 ///
2852 /// UPDATE_VISIBLE blocks contain the declarations that are added to an existing
2853 /// DeclContext in a dependent AST file. As such, they only exist for the TU
2854 /// (in C++) and for namespaces.
2855 void ASTWriter::WriteDeclContextVisibleUpdate(const DeclContext *DC) {
2856   StoredDeclsMap *Map = static_cast<StoredDeclsMap*>(DC->getLookupPtr());
2857   if (!Map || Map->empty())
2858     return;
2859 
2860   OnDiskChainedHashTableGenerator<ASTDeclContextNameLookupTrait> Generator;
2861   ASTDeclContextNameLookupTrait Trait(*this);
2862 
2863   // Create the hash table.
2864   for (StoredDeclsMap::iterator D = Map->begin(), DEnd = Map->end();
2865        D != DEnd; ++D) {
2866     DeclarationName Name = D->first;
2867     DeclContext::lookup_result Result = D->second.getLookupResult();
2868     // For any name that appears in this table, the results are complete, i.e.
2869     // they overwrite results from previous PCHs. Merging is always a mess.
2870     if (Result.first != Result.second)
2871       Generator.insert(Name, Result, Trait);
2872   }
2873 
2874   // Create the on-disk hash table in a buffer.
2875   llvm::SmallString<4096> LookupTable;
2876   uint32_t BucketOffset;
2877   {
2878     llvm::raw_svector_ostream Out(LookupTable);
2879     // Make sure that no bucket is at offset 0
2880     clang::io::Emit32(Out, 0);
2881     BucketOffset = Generator.Emit(Out, Trait);
2882   }
2883 
2884   // Write the lookup table
2885   RecordData Record;
2886   Record.push_back(UPDATE_VISIBLE);
2887   Record.push_back(getDeclID(cast<Decl>(DC)));
2888   Record.push_back(BucketOffset);
2889   Stream.EmitRecordWithBlob(UpdateVisibleAbbrev, Record, LookupTable.str());
2890 }
2891 
2892 /// \brief Write an FP_PRAGMA_OPTIONS block for the given FPOptions.
2893 void ASTWriter::WriteFPPragmaOptions(const FPOptions &Opts) {
2894   RecordData Record;
2895   Record.push_back(Opts.fp_contract);
2896   Stream.EmitRecord(FP_PRAGMA_OPTIONS, Record);
2897 }
2898 
2899 /// \brief Write an OPENCL_EXTENSIONS block for the given OpenCLOptions.
2900 void ASTWriter::WriteOpenCLExtensions(Sema &SemaRef) {
2901   if (!SemaRef.Context.getLangOptions().OpenCL)
2902     return;
2903 
2904   const OpenCLOptions &Opts = SemaRef.getOpenCLOptions();
2905   RecordData Record;
2906 #define OPENCLEXT(nm)  Record.push_back(Opts.nm);
2907 #include "clang/Basic/OpenCLExtensions.def"
2908   Stream.EmitRecord(OPENCL_EXTENSIONS, Record);
2909 }
2910 
2911 void ASTWriter::WriteRedeclarations() {
2912   RecordData LocalRedeclChains;
2913   SmallVector<serialization::LocalRedeclarationsInfo, 2> LocalRedeclsMap;
2914 
2915   for (unsigned I = 0, N = Redeclarations.size(); I != N; ++I) {
2916     Decl *First = Redeclarations[I];
2917     assert(First->getPreviousDecl() == 0 && "Not the first declaration?");
2918 
2919     Decl *MostRecent = First->getMostRecentDecl();
2920 
2921     // If we only have a single declaration, there is no point in storing
2922     // a redeclaration chain.
2923     if (First == MostRecent)
2924       continue;
2925 
2926     unsigned Offset = LocalRedeclChains.size();
2927     unsigned Size = 0;
2928     LocalRedeclChains.push_back(0); // Placeholder for the size.
2929 
2930     // Collect the set of local redeclarations of this declaration.
2931     for (Decl *Prev = MostRecent; Prev != First;
2932          Prev = Prev->getPreviousDecl()) {
2933       if (!Prev->isFromASTFile()) {
2934         AddDeclRef(Prev, LocalRedeclChains);
2935         ++Size;
2936       }
2937     }
2938     LocalRedeclChains[Offset] = Size;
2939 
2940     // Reverse the set of local redeclarations, so that we store them in
2941     // order (since we found them in reverse order).
2942     std::reverse(LocalRedeclChains.end() - Size, LocalRedeclChains.end());
2943 
2944     // Add the mapping from the first ID to the set of local declarations.
2945     LocalRedeclarationsInfo Info = { getDeclID(First), Offset };
2946     LocalRedeclsMap.push_back(Info);
2947 
2948     assert(N == Redeclarations.size() &&
2949            "Deserialized a declaration we shouldn't have");
2950   }
2951 
2952   if (LocalRedeclChains.empty())
2953     return;
2954 
2955   // Sort the local redeclarations map by the first declaration ID,
2956   // since the reader will be performing binary searches on this information.
2957   llvm::array_pod_sort(LocalRedeclsMap.begin(), LocalRedeclsMap.end());
2958 
2959   // Emit the local redeclarations map.
2960   using namespace llvm;
2961   llvm::BitCodeAbbrev *Abbrev = new BitCodeAbbrev();
2962   Abbrev->Add(BitCodeAbbrevOp(LOCAL_REDECLARATIONS_MAP));
2963   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // # of entries
2964   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
2965   unsigned AbbrevID = Stream.EmitAbbrev(Abbrev);
2966 
2967   RecordData Record;
2968   Record.push_back(LOCAL_REDECLARATIONS_MAP);
2969   Record.push_back(LocalRedeclsMap.size());
2970   Stream.EmitRecordWithBlob(AbbrevID, Record,
2971     reinterpret_cast<char*>(LocalRedeclsMap.data()),
2972     LocalRedeclsMap.size() * sizeof(LocalRedeclarationsInfo));
2973 
2974   // Emit the redeclaration chains.
2975   Stream.EmitRecord(LOCAL_REDECLARATIONS, LocalRedeclChains);
2976 }
2977 
2978 void ASTWriter::WriteMergedDecls() {
2979   if (!Chain || Chain->MergedDecls.empty())
2980     return;
2981 
2982   RecordData Record;
2983   for (ASTReader::MergedDeclsMap::iterator I = Chain->MergedDecls.begin(),
2984                                         IEnd = Chain->MergedDecls.end();
2985        I != IEnd; ++I) {
2986     DeclID CanonID = I->first->isFromASTFile()? I->first->getGlobalID()
2987                                               : getDeclID(I->first);
2988     assert(CanonID && "Merged declaration not known?");
2989 
2990     Record.push_back(CanonID);
2991     Record.push_back(I->second.size());
2992     Record.append(I->second.begin(), I->second.end());
2993   }
2994   Stream.EmitRecord(MERGED_DECLARATIONS, Record);
2995 }
2996 
2997 //===----------------------------------------------------------------------===//
2998 // General Serialization Routines
2999 //===----------------------------------------------------------------------===//
3000 
3001 /// \brief Write a record containing the given attributes.
3002 void ASTWriter::WriteAttributes(const AttrVec &Attrs, RecordDataImpl &Record) {
3003   Record.push_back(Attrs.size());
3004   for (AttrVec::const_iterator i = Attrs.begin(), e = Attrs.end(); i != e; ++i){
3005     const Attr * A = *i;
3006     Record.push_back(A->getKind()); // FIXME: stable encoding, target attrs
3007     AddSourceRange(A->getRange(), Record);
3008 
3009 #include "clang/Serialization/AttrPCHWrite.inc"
3010 
3011   }
3012 }
3013 
3014 void ASTWriter::AddString(StringRef Str, RecordDataImpl &Record) {
3015   Record.push_back(Str.size());
3016   Record.insert(Record.end(), Str.begin(), Str.end());
3017 }
3018 
3019 void ASTWriter::AddVersionTuple(const VersionTuple &Version,
3020                                 RecordDataImpl &Record) {
3021   Record.push_back(Version.getMajor());
3022   if (llvm::Optional<unsigned> Minor = Version.getMinor())
3023     Record.push_back(*Minor + 1);
3024   else
3025     Record.push_back(0);
3026   if (llvm::Optional<unsigned> Subminor = Version.getSubminor())
3027     Record.push_back(*Subminor + 1);
3028   else
3029     Record.push_back(0);
3030 }
3031 
3032 /// \brief Note that the identifier II occurs at the given offset
3033 /// within the identifier table.
3034 void ASTWriter::SetIdentifierOffset(const IdentifierInfo *II, uint32_t Offset) {
3035   IdentID ID = IdentifierIDs[II];
3036   // Only store offsets new to this AST file. Other identifier names are looked
3037   // up earlier in the chain and thus don't need an offset.
3038   if (ID >= FirstIdentID)
3039     IdentifierOffsets[ID - FirstIdentID] = Offset;
3040 }
3041 
3042 /// \brief Note that the selector Sel occurs at the given offset
3043 /// within the method pool/selector table.
3044 void ASTWriter::SetSelectorOffset(Selector Sel, uint32_t Offset) {
3045   unsigned ID = SelectorIDs[Sel];
3046   assert(ID && "Unknown selector");
3047   // Don't record offsets for selectors that are also available in a different
3048   // file.
3049   if (ID < FirstSelectorID)
3050     return;
3051   SelectorOffsets[ID - FirstSelectorID] = Offset;
3052 }
3053 
3054 ASTWriter::ASTWriter(llvm::BitstreamWriter &Stream)
3055   : Stream(Stream), Context(0), PP(0), Chain(0), WritingModule(0),
3056     WritingAST(false),
3057     FirstDeclID(NUM_PREDEF_DECL_IDS), NextDeclID(FirstDeclID),
3058     FirstTypeID(NUM_PREDEF_TYPE_IDS), NextTypeID(FirstTypeID),
3059     FirstIdentID(NUM_PREDEF_IDENT_IDS), NextIdentID(FirstIdentID),
3060     FirstSubmoduleID(NUM_PREDEF_SUBMODULE_IDS),
3061     NextSubmoduleID(FirstSubmoduleID),
3062     FirstSelectorID(NUM_PREDEF_SELECTOR_IDS), NextSelectorID(FirstSelectorID),
3063     CollectedStmts(&StmtsToEmit),
3064     NumStatements(0), NumMacros(0), NumLexicalDeclContexts(0),
3065     NumVisibleDeclContexts(0),
3066     NextCXXBaseSpecifiersID(1),
3067     DeclParmVarAbbrev(0), DeclContextLexicalAbbrev(0),
3068     DeclContextVisibleLookupAbbrev(0), UpdateVisibleAbbrev(0),
3069     DeclRefExprAbbrev(0), CharacterLiteralAbbrev(0),
3070     DeclRecordAbbrev(0), IntegerLiteralAbbrev(0),
3071     DeclTypedefAbbrev(0),
3072     DeclVarAbbrev(0), DeclFieldAbbrev(0),
3073     DeclEnumAbbrev(0), DeclObjCIvarAbbrev(0)
3074 {
3075 }
3076 
3077 ASTWriter::~ASTWriter() {
3078   for (FileDeclIDsTy::iterator
3079          I = FileDeclIDs.begin(), E = FileDeclIDs.end(); I != E; ++I)
3080     delete I->second;
3081 }
3082 
3083 void ASTWriter::WriteAST(Sema &SemaRef, MemorizeStatCalls *StatCalls,
3084                          const std::string &OutputFile,
3085                          Module *WritingModule, StringRef isysroot) {
3086   WritingAST = true;
3087 
3088   // Emit the file header.
3089   Stream.Emit((unsigned)'C', 8);
3090   Stream.Emit((unsigned)'P', 8);
3091   Stream.Emit((unsigned)'C', 8);
3092   Stream.Emit((unsigned)'H', 8);
3093 
3094   WriteBlockInfoBlock();
3095 
3096   Context = &SemaRef.Context;
3097   PP = &SemaRef.PP;
3098   this->WritingModule = WritingModule;
3099   WriteASTCore(SemaRef, StatCalls, isysroot, OutputFile, WritingModule);
3100   Context = 0;
3101   PP = 0;
3102   this->WritingModule = 0;
3103 
3104   WritingAST = false;
3105 }
3106 
3107 template<typename Vector>
3108 static void AddLazyVectorDecls(ASTWriter &Writer, Vector &Vec,
3109                                ASTWriter::RecordData &Record) {
3110   for (typename Vector::iterator I = Vec.begin(0, true), E = Vec.end();
3111        I != E; ++I)  {
3112     Writer.AddDeclRef(*I, Record);
3113   }
3114 }
3115 
3116 void ASTWriter::WriteASTCore(Sema &SemaRef, MemorizeStatCalls *StatCalls,
3117                              StringRef isysroot,
3118                              const std::string &OutputFile,
3119                              Module *WritingModule) {
3120   using namespace llvm;
3121 
3122   // Make sure that the AST reader knows to finalize itself.
3123   if (Chain)
3124     Chain->finalizeForWriting();
3125 
3126   ASTContext &Context = SemaRef.Context;
3127   Preprocessor &PP = SemaRef.PP;
3128 
3129   // Set up predefined declaration IDs.
3130   DeclIDs[Context.getTranslationUnitDecl()] = PREDEF_DECL_TRANSLATION_UNIT_ID;
3131   if (Context.ObjCIdDecl)
3132     DeclIDs[Context.ObjCIdDecl] = PREDEF_DECL_OBJC_ID_ID;
3133   if (Context.ObjCSelDecl)
3134     DeclIDs[Context.ObjCSelDecl] = PREDEF_DECL_OBJC_SEL_ID;
3135   if (Context.ObjCClassDecl)
3136     DeclIDs[Context.ObjCClassDecl] = PREDEF_DECL_OBJC_CLASS_ID;
3137   if (Context.Int128Decl)
3138     DeclIDs[Context.Int128Decl] = PREDEF_DECL_INT_128_ID;
3139   if (Context.UInt128Decl)
3140     DeclIDs[Context.UInt128Decl] = PREDEF_DECL_UNSIGNED_INT_128_ID;
3141   if (Context.ObjCInstanceTypeDecl)
3142     DeclIDs[Context.ObjCInstanceTypeDecl] = PREDEF_DECL_OBJC_INSTANCETYPE_ID;
3143 
3144   if (!Chain) {
3145     // Make sure that we emit IdentifierInfos (and any attached
3146     // declarations) for builtins. We don't need to do this when we're
3147     // emitting chained PCH files, because all of the builtins will be
3148     // in the original PCH file.
3149     // FIXME: Modules won't like this at all.
3150     IdentifierTable &Table = PP.getIdentifierTable();
3151     SmallVector<const char *, 32> BuiltinNames;
3152     Context.BuiltinInfo.GetBuiltinNames(BuiltinNames,
3153                                         Context.getLangOptions().NoBuiltin);
3154     for (unsigned I = 0, N = BuiltinNames.size(); I != N; ++I)
3155       getIdentifierRef(&Table.get(BuiltinNames[I]));
3156   }
3157 
3158   // If there are any out-of-date identifiers, bring them up to date.
3159   if (ExternalPreprocessorSource *ExtSource = PP.getExternalSource()) {
3160     for (IdentifierTable::iterator ID = PP.getIdentifierTable().begin(),
3161                                 IDEnd = PP.getIdentifierTable().end();
3162          ID != IDEnd; ++ID)
3163       if (ID->second->isOutOfDate())
3164         ExtSource->updateOutOfDateIdentifier(*ID->second);
3165   }
3166 
3167   // Build a record containing all of the tentative definitions in this file, in
3168   // TentativeDefinitions order.  Generally, this record will be empty for
3169   // headers.
3170   RecordData TentativeDefinitions;
3171   AddLazyVectorDecls(*this, SemaRef.TentativeDefinitions, TentativeDefinitions);
3172 
3173   // Build a record containing all of the file scoped decls in this file.
3174   RecordData UnusedFileScopedDecls;
3175   AddLazyVectorDecls(*this, SemaRef.UnusedFileScopedDecls,
3176                      UnusedFileScopedDecls);
3177 
3178   // Build a record containing all of the delegating constructors we still need
3179   // to resolve.
3180   RecordData DelegatingCtorDecls;
3181   AddLazyVectorDecls(*this, SemaRef.DelegatingCtorDecls, DelegatingCtorDecls);
3182 
3183   // Write the set of weak, undeclared identifiers. We always write the
3184   // entire table, since later PCH files in a PCH chain are only interested in
3185   // the results at the end of the chain.
3186   RecordData WeakUndeclaredIdentifiers;
3187   if (!SemaRef.WeakUndeclaredIdentifiers.empty()) {
3188     for (llvm::DenseMap<IdentifierInfo*,WeakInfo>::iterator
3189          I = SemaRef.WeakUndeclaredIdentifiers.begin(),
3190          E = SemaRef.WeakUndeclaredIdentifiers.end(); I != E; ++I) {
3191       AddIdentifierRef(I->first, WeakUndeclaredIdentifiers);
3192       AddIdentifierRef(I->second.getAlias(), WeakUndeclaredIdentifiers);
3193       AddSourceLocation(I->second.getLocation(), WeakUndeclaredIdentifiers);
3194       WeakUndeclaredIdentifiers.push_back(I->second.getUsed());
3195     }
3196   }
3197 
3198   // Build a record containing all of the locally-scoped external
3199   // declarations in this header file. Generally, this record will be
3200   // empty.
3201   RecordData LocallyScopedExternalDecls;
3202   // FIXME: This is filling in the AST file in densemap order which is
3203   // nondeterminstic!
3204   for (llvm::DenseMap<DeclarationName, NamedDecl *>::iterator
3205          TD = SemaRef.LocallyScopedExternalDecls.begin(),
3206          TDEnd = SemaRef.LocallyScopedExternalDecls.end();
3207        TD != TDEnd; ++TD) {
3208     if (!TD->second->isFromASTFile())
3209       AddDeclRef(TD->second, LocallyScopedExternalDecls);
3210   }
3211 
3212   // Build a record containing all of the ext_vector declarations.
3213   RecordData ExtVectorDecls;
3214   AddLazyVectorDecls(*this, SemaRef.ExtVectorDecls, ExtVectorDecls);
3215 
3216   // Build a record containing all of the VTable uses information.
3217   RecordData VTableUses;
3218   if (!SemaRef.VTableUses.empty()) {
3219     for (unsigned I = 0, N = SemaRef.VTableUses.size(); I != N; ++I) {
3220       AddDeclRef(SemaRef.VTableUses[I].first, VTableUses);
3221       AddSourceLocation(SemaRef.VTableUses[I].second, VTableUses);
3222       VTableUses.push_back(SemaRef.VTablesUsed[SemaRef.VTableUses[I].first]);
3223     }
3224   }
3225 
3226   // Build a record containing all of dynamic classes declarations.
3227   RecordData DynamicClasses;
3228   AddLazyVectorDecls(*this, SemaRef.DynamicClasses, DynamicClasses);
3229 
3230   // Build a record containing all of pending implicit instantiations.
3231   RecordData PendingInstantiations;
3232   for (std::deque<Sema::PendingImplicitInstantiation>::iterator
3233          I = SemaRef.PendingInstantiations.begin(),
3234          N = SemaRef.PendingInstantiations.end(); I != N; ++I) {
3235     AddDeclRef(I->first, PendingInstantiations);
3236     AddSourceLocation(I->second, PendingInstantiations);
3237   }
3238   assert(SemaRef.PendingLocalImplicitInstantiations.empty() &&
3239          "There are local ones at end of translation unit!");
3240 
3241   // Build a record containing some declaration references.
3242   RecordData SemaDeclRefs;
3243   if (SemaRef.StdNamespace || SemaRef.StdBadAlloc) {
3244     AddDeclRef(SemaRef.getStdNamespace(), SemaDeclRefs);
3245     AddDeclRef(SemaRef.getStdBadAlloc(), SemaDeclRefs);
3246   }
3247 
3248   RecordData CUDASpecialDeclRefs;
3249   if (Context.getcudaConfigureCallDecl()) {
3250     AddDeclRef(Context.getcudaConfigureCallDecl(), CUDASpecialDeclRefs);
3251   }
3252 
3253   // Build a record containing all of the known namespaces.
3254   RecordData KnownNamespaces;
3255   for (llvm::DenseMap<NamespaceDecl*, bool>::iterator
3256             I = SemaRef.KnownNamespaces.begin(),
3257          IEnd = SemaRef.KnownNamespaces.end();
3258        I != IEnd; ++I) {
3259     if (!I->second)
3260       AddDeclRef(I->first, KnownNamespaces);
3261   }
3262 
3263   // Write the remaining AST contents.
3264   RecordData Record;
3265   Stream.EnterSubblock(AST_BLOCK_ID, 5);
3266   WriteMetadata(Context, isysroot, OutputFile);
3267   WriteLanguageOptions(Context.getLangOptions());
3268   if (StatCalls && isysroot.empty())
3269     WriteStatCache(*StatCalls);
3270 
3271   // Create a lexical update block containing all of the declarations in the
3272   // translation unit that do not come from other AST files.
3273   const TranslationUnitDecl *TU = Context.getTranslationUnitDecl();
3274   SmallVector<KindDeclIDPair, 64> NewGlobalDecls;
3275   for (DeclContext::decl_iterator I = TU->noload_decls_begin(),
3276                                   E = TU->noload_decls_end();
3277        I != E; ++I) {
3278     if (!(*I)->isFromASTFile())
3279       NewGlobalDecls.push_back(std::make_pair((*I)->getKind(), GetDeclRef(*I)));
3280   }
3281 
3282   llvm::BitCodeAbbrev *Abv = new llvm::BitCodeAbbrev();
3283   Abv->Add(llvm::BitCodeAbbrevOp(TU_UPDATE_LEXICAL));
3284   Abv->Add(llvm::BitCodeAbbrevOp(llvm::BitCodeAbbrevOp::Blob));
3285   unsigned TuUpdateLexicalAbbrev = Stream.EmitAbbrev(Abv);
3286   Record.clear();
3287   Record.push_back(TU_UPDATE_LEXICAL);
3288   Stream.EmitRecordWithBlob(TuUpdateLexicalAbbrev, Record,
3289                             data(NewGlobalDecls));
3290 
3291   // And a visible updates block for the translation unit.
3292   Abv = new llvm::BitCodeAbbrev();
3293   Abv->Add(llvm::BitCodeAbbrevOp(UPDATE_VISIBLE));
3294   Abv->Add(llvm::BitCodeAbbrevOp(llvm::BitCodeAbbrevOp::VBR, 6));
3295   Abv->Add(llvm::BitCodeAbbrevOp(llvm::BitCodeAbbrevOp::Fixed, 32));
3296   Abv->Add(llvm::BitCodeAbbrevOp(llvm::BitCodeAbbrevOp::Blob));
3297   UpdateVisibleAbbrev = Stream.EmitAbbrev(Abv);
3298   WriteDeclContextVisibleUpdate(TU);
3299 
3300   // If the translation unit has an anonymous namespace, and we don't already
3301   // have an update block for it, write it as an update block.
3302   if (NamespaceDecl *NS = TU->getAnonymousNamespace()) {
3303     ASTWriter::UpdateRecord &Record = DeclUpdates[TU];
3304     if (Record.empty()) {
3305       Record.push_back(UPD_CXX_ADDED_ANONYMOUS_NAMESPACE);
3306       Record.push_back(reinterpret_cast<uint64_t>(NS));
3307     }
3308   }
3309 
3310   // Resolve any declaration pointers within the declaration updates block.
3311   ResolveDeclUpdatesBlocks();
3312 
3313   // Form the record of special types.
3314   RecordData SpecialTypes;
3315   AddTypeRef(Context.getBuiltinVaListType(), SpecialTypes);
3316   AddTypeRef(Context.ObjCProtoType, SpecialTypes);
3317   AddTypeRef(Context.getRawCFConstantStringType(), SpecialTypes);
3318   AddTypeRef(Context.getFILEType(), SpecialTypes);
3319   AddTypeRef(Context.getjmp_bufType(), SpecialTypes);
3320   AddTypeRef(Context.getsigjmp_bufType(), SpecialTypes);
3321   AddTypeRef(Context.ObjCIdRedefinitionType, SpecialTypes);
3322   AddTypeRef(Context.ObjCClassRedefinitionType, SpecialTypes);
3323   AddTypeRef(Context.ObjCSelRedefinitionType, SpecialTypes);
3324   AddTypeRef(Context.getucontext_tType(), SpecialTypes);
3325 
3326   // Keep writing types and declarations until all types and
3327   // declarations have been written.
3328   Stream.EnterSubblock(DECLTYPES_BLOCK_ID, NUM_ALLOWED_ABBREVS_SIZE);
3329   WriteDeclsBlockAbbrevs();
3330   for (DeclsToRewriteTy::iterator I = DeclsToRewrite.begin(),
3331                                   E = DeclsToRewrite.end();
3332        I != E; ++I)
3333     DeclTypesToEmit.push(const_cast<Decl*>(*I));
3334   while (!DeclTypesToEmit.empty()) {
3335     DeclOrType DOT = DeclTypesToEmit.front();
3336     DeclTypesToEmit.pop();
3337     if (DOT.isType())
3338       WriteType(DOT.getType());
3339     else
3340       WriteDecl(Context, DOT.getDecl());
3341   }
3342   Stream.ExitBlock();
3343 
3344   WriteFileDeclIDsMap();
3345   WriteSourceManagerBlock(Context.getSourceManager(), PP, isysroot);
3346 
3347   if (Chain) {
3348     // Write the mapping information describing our module dependencies and how
3349     // each of those modules were mapped into our own offset/ID space, so that
3350     // the reader can build the appropriate mapping to its own offset/ID space.
3351     // The map consists solely of a blob with the following format:
3352     // *(module-name-len:i16 module-name:len*i8
3353     //   source-location-offset:i32
3354     //   identifier-id:i32
3355     //   preprocessed-entity-id:i32
3356     //   macro-definition-id:i32
3357     //   submodule-id:i32
3358     //   selector-id:i32
3359     //   declaration-id:i32
3360     //   c++-base-specifiers-id:i32
3361     //   type-id:i32)
3362     //
3363     llvm::BitCodeAbbrev *Abbrev = new BitCodeAbbrev();
3364     Abbrev->Add(BitCodeAbbrevOp(MODULE_OFFSET_MAP));
3365     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
3366     unsigned ModuleOffsetMapAbbrev = Stream.EmitAbbrev(Abbrev);
3367     llvm::SmallString<2048> Buffer;
3368     {
3369       llvm::raw_svector_ostream Out(Buffer);
3370       for (ModuleManager::ModuleConstIterator M = Chain->ModuleMgr.begin(),
3371                                            MEnd = Chain->ModuleMgr.end();
3372            M != MEnd; ++M) {
3373         StringRef FileName = (*M)->FileName;
3374         io::Emit16(Out, FileName.size());
3375         Out.write(FileName.data(), FileName.size());
3376         io::Emit32(Out, (*M)->SLocEntryBaseOffset);
3377         io::Emit32(Out, (*M)->BaseIdentifierID);
3378         io::Emit32(Out, (*M)->BasePreprocessedEntityID);
3379         io::Emit32(Out, (*M)->BaseSubmoduleID);
3380         io::Emit32(Out, (*M)->BaseSelectorID);
3381         io::Emit32(Out, (*M)->BaseDeclID);
3382         io::Emit32(Out, (*M)->BaseTypeIndex);
3383       }
3384     }
3385     Record.clear();
3386     Record.push_back(MODULE_OFFSET_MAP);
3387     Stream.EmitRecordWithBlob(ModuleOffsetMapAbbrev, Record,
3388                               Buffer.data(), Buffer.size());
3389   }
3390   WritePreprocessor(PP, WritingModule != 0);
3391   WriteHeaderSearch(PP.getHeaderSearchInfo(), isysroot);
3392   WriteSelectors(SemaRef);
3393   WriteReferencedSelectorsPool(SemaRef);
3394   WriteIdentifierTable(PP, SemaRef.IdResolver, WritingModule != 0);
3395   WriteFPPragmaOptions(SemaRef.getFPOptions());
3396   WriteOpenCLExtensions(SemaRef);
3397 
3398   WriteTypeDeclOffsets();
3399   WritePragmaDiagnosticMappings(Context.getDiagnostics());
3400 
3401   WriteCXXBaseSpecifiersOffsets();
3402 
3403   // If we're emitting a module, write out the submodule information.
3404   if (WritingModule)
3405     WriteSubmodules(WritingModule);
3406 
3407   Stream.EmitRecord(SPECIAL_TYPES, SpecialTypes);
3408 
3409   // Write the record containing external, unnamed definitions.
3410   if (!ExternalDefinitions.empty())
3411     Stream.EmitRecord(EXTERNAL_DEFINITIONS, ExternalDefinitions);
3412 
3413   // Write the record containing tentative definitions.
3414   if (!TentativeDefinitions.empty())
3415     Stream.EmitRecord(TENTATIVE_DEFINITIONS, TentativeDefinitions);
3416 
3417   // Write the record containing unused file scoped decls.
3418   if (!UnusedFileScopedDecls.empty())
3419     Stream.EmitRecord(UNUSED_FILESCOPED_DECLS, UnusedFileScopedDecls);
3420 
3421   // Write the record containing weak undeclared identifiers.
3422   if (!WeakUndeclaredIdentifiers.empty())
3423     Stream.EmitRecord(WEAK_UNDECLARED_IDENTIFIERS,
3424                       WeakUndeclaredIdentifiers);
3425 
3426   // Write the record containing locally-scoped external definitions.
3427   if (!LocallyScopedExternalDecls.empty())
3428     Stream.EmitRecord(LOCALLY_SCOPED_EXTERNAL_DECLS,
3429                       LocallyScopedExternalDecls);
3430 
3431   // Write the record containing ext_vector type names.
3432   if (!ExtVectorDecls.empty())
3433     Stream.EmitRecord(EXT_VECTOR_DECLS, ExtVectorDecls);
3434 
3435   // Write the record containing VTable uses information.
3436   if (!VTableUses.empty())
3437     Stream.EmitRecord(VTABLE_USES, VTableUses);
3438 
3439   // Write the record containing dynamic classes declarations.
3440   if (!DynamicClasses.empty())
3441     Stream.EmitRecord(DYNAMIC_CLASSES, DynamicClasses);
3442 
3443   // Write the record containing pending implicit instantiations.
3444   if (!PendingInstantiations.empty())
3445     Stream.EmitRecord(PENDING_IMPLICIT_INSTANTIATIONS, PendingInstantiations);
3446 
3447   // Write the record containing declaration references of Sema.
3448   if (!SemaDeclRefs.empty())
3449     Stream.EmitRecord(SEMA_DECL_REFS, SemaDeclRefs);
3450 
3451   // Write the record containing CUDA-specific declaration references.
3452   if (!CUDASpecialDeclRefs.empty())
3453     Stream.EmitRecord(CUDA_SPECIAL_DECL_REFS, CUDASpecialDeclRefs);
3454 
3455   // Write the delegating constructors.
3456   if (!DelegatingCtorDecls.empty())
3457     Stream.EmitRecord(DELEGATING_CTORS, DelegatingCtorDecls);
3458 
3459   // Write the known namespaces.
3460   if (!KnownNamespaces.empty())
3461     Stream.EmitRecord(KNOWN_NAMESPACES, KnownNamespaces);
3462 
3463   // Write the visible updates to DeclContexts.
3464   for (llvm::SmallPtrSet<const DeclContext *, 16>::iterator
3465        I = UpdatedDeclContexts.begin(),
3466        E = UpdatedDeclContexts.end();
3467        I != E; ++I)
3468     WriteDeclContextVisibleUpdate(*I);
3469 
3470   if (!WritingModule) {
3471     // Write the submodules that were imported, if any.
3472     RecordData ImportedModules;
3473     for (ASTContext::import_iterator I = Context.local_import_begin(),
3474                                   IEnd = Context.local_import_end();
3475          I != IEnd; ++I) {
3476       assert(SubmoduleIDs.find(I->getImportedModule()) != SubmoduleIDs.end());
3477       ImportedModules.push_back(SubmoduleIDs[I->getImportedModule()]);
3478     }
3479     if (!ImportedModules.empty()) {
3480       // Sort module IDs.
3481       llvm::array_pod_sort(ImportedModules.begin(), ImportedModules.end());
3482 
3483       // Unique module IDs.
3484       ImportedModules.erase(std::unique(ImportedModules.begin(),
3485                                         ImportedModules.end()),
3486                             ImportedModules.end());
3487 
3488       Stream.EmitRecord(IMPORTED_MODULES, ImportedModules);
3489     }
3490   }
3491 
3492   WriteDeclUpdatesBlocks();
3493   WriteDeclReplacementsBlock();
3494   WriteChainedObjCCategories();
3495   WriteMergedDecls();
3496   WriteRedeclarations();
3497 
3498   // Some simple statistics
3499   Record.clear();
3500   Record.push_back(NumStatements);
3501   Record.push_back(NumMacros);
3502   Record.push_back(NumLexicalDeclContexts);
3503   Record.push_back(NumVisibleDeclContexts);
3504   Stream.EmitRecord(STATISTICS, Record);
3505   Stream.ExitBlock();
3506 }
3507 
3508 /// \brief Go through the declaration update blocks and resolve declaration
3509 /// pointers into declaration IDs.
3510 void ASTWriter::ResolveDeclUpdatesBlocks() {
3511   for (DeclUpdateMap::iterator
3512        I = DeclUpdates.begin(), E = DeclUpdates.end(); I != E; ++I) {
3513     const Decl *D = I->first;
3514     UpdateRecord &URec = I->second;
3515 
3516     if (isRewritten(D))
3517       continue; // The decl will be written completely
3518 
3519     unsigned Idx = 0, N = URec.size();
3520     while (Idx < N) {
3521       switch ((DeclUpdateKind)URec[Idx++]) {
3522       case UPD_CXX_ADDED_IMPLICIT_MEMBER:
3523       case UPD_CXX_ADDED_TEMPLATE_SPECIALIZATION:
3524       case UPD_CXX_ADDED_ANONYMOUS_NAMESPACE:
3525         URec[Idx] = GetDeclRef(reinterpret_cast<Decl *>(URec[Idx]));
3526         ++Idx;
3527         break;
3528 
3529       case UPD_CXX_INSTANTIATED_STATIC_DATA_MEMBER:
3530         ++Idx;
3531         break;
3532       }
3533     }
3534   }
3535 }
3536 
3537 void ASTWriter::WriteDeclUpdatesBlocks() {
3538   if (DeclUpdates.empty())
3539     return;
3540 
3541   RecordData OffsetsRecord;
3542   Stream.EnterSubblock(DECL_UPDATES_BLOCK_ID, NUM_ALLOWED_ABBREVS_SIZE);
3543   for (DeclUpdateMap::iterator
3544          I = DeclUpdates.begin(), E = DeclUpdates.end(); I != E; ++I) {
3545     const Decl *D = I->first;
3546     UpdateRecord &URec = I->second;
3547 
3548     if (isRewritten(D))
3549       continue; // The decl will be written completely,no need to store updates.
3550 
3551     uint64_t Offset = Stream.GetCurrentBitNo();
3552     Stream.EmitRecord(DECL_UPDATES, URec);
3553 
3554     OffsetsRecord.push_back(GetDeclRef(D));
3555     OffsetsRecord.push_back(Offset);
3556   }
3557   Stream.ExitBlock();
3558   Stream.EmitRecord(DECL_UPDATE_OFFSETS, OffsetsRecord);
3559 }
3560 
3561 void ASTWriter::WriteDeclReplacementsBlock() {
3562   if (ReplacedDecls.empty())
3563     return;
3564 
3565   RecordData Record;
3566   for (SmallVector<ReplacedDeclInfo, 16>::iterator
3567            I = ReplacedDecls.begin(), E = ReplacedDecls.end(); I != E; ++I) {
3568     Record.push_back(I->ID);
3569     Record.push_back(I->Offset);
3570     Record.push_back(I->Loc);
3571   }
3572   Stream.EmitRecord(DECL_REPLACEMENTS, Record);
3573 }
3574 
3575 void ASTWriter::WriteChainedObjCCategories() {
3576   if (LocalChainedObjCCategories.empty())
3577     return;
3578 
3579   RecordData Record;
3580   for (SmallVector<ChainedObjCCategoriesData, 16>::iterator
3581          I = LocalChainedObjCCategories.begin(),
3582          E = LocalChainedObjCCategories.end(); I != E; ++I) {
3583     ChainedObjCCategoriesData &Data = *I;
3584     if (isRewritten(Data.Interface))
3585       continue;
3586 
3587     assert(Data.Interface->getCategoryList());
3588     serialization::DeclID
3589         HeadCatID = getDeclID(Data.Interface->getCategoryList());
3590 
3591     Record.push_back(getDeclID(Data.Interface));
3592     Record.push_back(HeadCatID);
3593     Record.push_back(getDeclID(Data.TailCategory));
3594   }
3595   Stream.EmitRecord(OBJC_CHAINED_CATEGORIES, Record);
3596 }
3597 
3598 void ASTWriter::AddSourceLocation(SourceLocation Loc, RecordDataImpl &Record) {
3599   Record.push_back(Loc.getRawEncoding());
3600 }
3601 
3602 void ASTWriter::AddSourceRange(SourceRange Range, RecordDataImpl &Record) {
3603   AddSourceLocation(Range.getBegin(), Record);
3604   AddSourceLocation(Range.getEnd(), Record);
3605 }
3606 
3607 void ASTWriter::AddAPInt(const llvm::APInt &Value, RecordDataImpl &Record) {
3608   Record.push_back(Value.getBitWidth());
3609   const uint64_t *Words = Value.getRawData();
3610   Record.append(Words, Words + Value.getNumWords());
3611 }
3612 
3613 void ASTWriter::AddAPSInt(const llvm::APSInt &Value, RecordDataImpl &Record) {
3614   Record.push_back(Value.isUnsigned());
3615   AddAPInt(Value, Record);
3616 }
3617 
3618 void ASTWriter::AddAPFloat(const llvm::APFloat &Value, RecordDataImpl &Record) {
3619   AddAPInt(Value.bitcastToAPInt(), Record);
3620 }
3621 
3622 void ASTWriter::AddIdentifierRef(const IdentifierInfo *II, RecordDataImpl &Record) {
3623   Record.push_back(getIdentifierRef(II));
3624 }
3625 
3626 IdentID ASTWriter::getIdentifierRef(const IdentifierInfo *II) {
3627   if (II == 0)
3628     return 0;
3629 
3630   IdentID &ID = IdentifierIDs[II];
3631   if (ID == 0)
3632     ID = NextIdentID++;
3633   return ID;
3634 }
3635 
3636 void ASTWriter::AddSelectorRef(const Selector SelRef, RecordDataImpl &Record) {
3637   Record.push_back(getSelectorRef(SelRef));
3638 }
3639 
3640 SelectorID ASTWriter::getSelectorRef(Selector Sel) {
3641   if (Sel.getAsOpaquePtr() == 0) {
3642     return 0;
3643   }
3644 
3645   SelectorID &SID = SelectorIDs[Sel];
3646   if (SID == 0 && Chain) {
3647     // This might trigger a ReadSelector callback, which will set the ID for
3648     // this selector.
3649     Chain->LoadSelector(Sel);
3650   }
3651   if (SID == 0) {
3652     SID = NextSelectorID++;
3653   }
3654   return SID;
3655 }
3656 
3657 void ASTWriter::AddCXXTemporary(const CXXTemporary *Temp, RecordDataImpl &Record) {
3658   AddDeclRef(Temp->getDestructor(), Record);
3659 }
3660 
3661 void ASTWriter::AddCXXBaseSpecifiersRef(CXXBaseSpecifier const *Bases,
3662                                       CXXBaseSpecifier const *BasesEnd,
3663                                         RecordDataImpl &Record) {
3664   assert(Bases != BasesEnd && "Empty base-specifier sets are not recorded");
3665   CXXBaseSpecifiersToWrite.push_back(
3666                                 QueuedCXXBaseSpecifiers(NextCXXBaseSpecifiersID,
3667                                                         Bases, BasesEnd));
3668   Record.push_back(NextCXXBaseSpecifiersID++);
3669 }
3670 
3671 void ASTWriter::AddTemplateArgumentLocInfo(TemplateArgument::ArgKind Kind,
3672                                            const TemplateArgumentLocInfo &Arg,
3673                                            RecordDataImpl &Record) {
3674   switch (Kind) {
3675   case TemplateArgument::Expression:
3676     AddStmt(Arg.getAsExpr());
3677     break;
3678   case TemplateArgument::Type:
3679     AddTypeSourceInfo(Arg.getAsTypeSourceInfo(), Record);
3680     break;
3681   case TemplateArgument::Template:
3682     AddNestedNameSpecifierLoc(Arg.getTemplateQualifierLoc(), Record);
3683     AddSourceLocation(Arg.getTemplateNameLoc(), Record);
3684     break;
3685   case TemplateArgument::TemplateExpansion:
3686     AddNestedNameSpecifierLoc(Arg.getTemplateQualifierLoc(), Record);
3687     AddSourceLocation(Arg.getTemplateNameLoc(), Record);
3688     AddSourceLocation(Arg.getTemplateEllipsisLoc(), Record);
3689     break;
3690   case TemplateArgument::Null:
3691   case TemplateArgument::Integral:
3692   case TemplateArgument::Declaration:
3693   case TemplateArgument::Pack:
3694     break;
3695   }
3696 }
3697 
3698 void ASTWriter::AddTemplateArgumentLoc(const TemplateArgumentLoc &Arg,
3699                                        RecordDataImpl &Record) {
3700   AddTemplateArgument(Arg.getArgument(), Record);
3701 
3702   if (Arg.getArgument().getKind() == TemplateArgument::Expression) {
3703     bool InfoHasSameExpr
3704       = Arg.getArgument().getAsExpr() == Arg.getLocInfo().getAsExpr();
3705     Record.push_back(InfoHasSameExpr);
3706     if (InfoHasSameExpr)
3707       return; // Avoid storing the same expr twice.
3708   }
3709   AddTemplateArgumentLocInfo(Arg.getArgument().getKind(), Arg.getLocInfo(),
3710                              Record);
3711 }
3712 
3713 void ASTWriter::AddTypeSourceInfo(TypeSourceInfo *TInfo,
3714                                   RecordDataImpl &Record) {
3715   if (TInfo == 0) {
3716     AddTypeRef(QualType(), Record);
3717     return;
3718   }
3719 
3720   AddTypeLoc(TInfo->getTypeLoc(), Record);
3721 }
3722 
3723 void ASTWriter::AddTypeLoc(TypeLoc TL, RecordDataImpl &Record) {
3724   AddTypeRef(TL.getType(), Record);
3725 
3726   TypeLocWriter TLW(*this, Record);
3727   for (; !TL.isNull(); TL = TL.getNextTypeLoc())
3728     TLW.Visit(TL);
3729 }
3730 
3731 void ASTWriter::AddTypeRef(QualType T, RecordDataImpl &Record) {
3732   Record.push_back(GetOrCreateTypeID(T));
3733 }
3734 
3735 TypeID ASTWriter::GetOrCreateTypeID( QualType T) {
3736   return MakeTypeID(*Context, T,
3737               std::bind1st(std::mem_fun(&ASTWriter::GetOrCreateTypeIdx), this));
3738 }
3739 
3740 TypeID ASTWriter::getTypeID(QualType T) const {
3741   return MakeTypeID(*Context, T,
3742               std::bind1st(std::mem_fun(&ASTWriter::getTypeIdx), this));
3743 }
3744 
3745 TypeIdx ASTWriter::GetOrCreateTypeIdx(QualType T) {
3746   if (T.isNull())
3747     return TypeIdx();
3748   assert(!T.getLocalFastQualifiers());
3749 
3750   TypeIdx &Idx = TypeIdxs[T];
3751   if (Idx.getIndex() == 0) {
3752     // We haven't seen this type before. Assign it a new ID and put it
3753     // into the queue of types to emit.
3754     Idx = TypeIdx(NextTypeID++);
3755     DeclTypesToEmit.push(T);
3756   }
3757   return Idx;
3758 }
3759 
3760 TypeIdx ASTWriter::getTypeIdx(QualType T) const {
3761   if (T.isNull())
3762     return TypeIdx();
3763   assert(!T.getLocalFastQualifiers());
3764 
3765   TypeIdxMap::const_iterator I = TypeIdxs.find(T);
3766   assert(I != TypeIdxs.end() && "Type not emitted!");
3767   return I->second;
3768 }
3769 
3770 void ASTWriter::AddDeclRef(const Decl *D, RecordDataImpl &Record) {
3771   Record.push_back(GetDeclRef(D));
3772 }
3773 
3774 DeclID ASTWriter::GetDeclRef(const Decl *D) {
3775   assert(WritingAST && "Cannot request a declaration ID before AST writing");
3776 
3777   if (D == 0) {
3778     return 0;
3779   }
3780 
3781   // If D comes from an AST file, its declaration ID is already known and
3782   // fixed.
3783   if (D->isFromASTFile())
3784     return D->getGlobalID();
3785 
3786   assert(!(reinterpret_cast<uintptr_t>(D) & 0x01) && "Invalid decl pointer");
3787   DeclID &ID = DeclIDs[D];
3788   if (ID == 0) {
3789     // We haven't seen this declaration before. Give it a new ID and
3790     // enqueue it in the list of declarations to emit.
3791     ID = NextDeclID++;
3792     DeclTypesToEmit.push(const_cast<Decl *>(D));
3793   }
3794 
3795   return ID;
3796 }
3797 
3798 DeclID ASTWriter::getDeclID(const Decl *D) {
3799   if (D == 0)
3800     return 0;
3801 
3802   // If D comes from an AST file, its declaration ID is already known and
3803   // fixed.
3804   if (D->isFromASTFile())
3805     return D->getGlobalID();
3806 
3807   assert(DeclIDs.find(D) != DeclIDs.end() && "Declaration not emitted!");
3808   return DeclIDs[D];
3809 }
3810 
3811 static inline bool compLocDecl(std::pair<unsigned, serialization::DeclID> L,
3812                                std::pair<unsigned, serialization::DeclID> R) {
3813   return L.first < R.first;
3814 }
3815 
3816 void ASTWriter::associateDeclWithFile(const Decl *D, DeclID ID) {
3817   assert(ID);
3818   assert(D);
3819 
3820   SourceLocation Loc = D->getLocation();
3821   if (Loc.isInvalid())
3822     return;
3823 
3824   // We only keep track of the file-level declarations of each file.
3825   if (!D->getLexicalDeclContext()->isFileContext())
3826     return;
3827 
3828   SourceManager &SM = Context->getSourceManager();
3829   SourceLocation FileLoc = SM.getFileLoc(Loc);
3830   assert(SM.isLocalSourceLocation(FileLoc));
3831   FileID FID;
3832   unsigned Offset;
3833   llvm::tie(FID, Offset) = SM.getDecomposedLoc(FileLoc);
3834   if (FID.isInvalid())
3835     return;
3836   const SrcMgr::SLocEntry *Entry = &SM.getSLocEntry(FID);
3837   assert(Entry->isFile());
3838 
3839   DeclIDInFileInfo *&Info = FileDeclIDs[Entry];
3840   if (!Info)
3841     Info = new DeclIDInFileInfo();
3842 
3843   std::pair<unsigned, serialization::DeclID> LocDecl(Offset, ID);
3844   LocDeclIDsTy &Decls = Info->DeclIDs;
3845 
3846   if (Decls.empty() || Decls.back().first <= Offset) {
3847     Decls.push_back(LocDecl);
3848     return;
3849   }
3850 
3851   LocDeclIDsTy::iterator
3852     I = std::upper_bound(Decls.begin(), Decls.end(), LocDecl, compLocDecl);
3853 
3854   Decls.insert(I, LocDecl);
3855 }
3856 
3857 void ASTWriter::AddDeclarationName(DeclarationName Name, RecordDataImpl &Record) {
3858   // FIXME: Emit a stable enum for NameKind.  0 = Identifier etc.
3859   Record.push_back(Name.getNameKind());
3860   switch (Name.getNameKind()) {
3861   case DeclarationName::Identifier:
3862     AddIdentifierRef(Name.getAsIdentifierInfo(), Record);
3863     break;
3864 
3865   case DeclarationName::ObjCZeroArgSelector:
3866   case DeclarationName::ObjCOneArgSelector:
3867   case DeclarationName::ObjCMultiArgSelector:
3868     AddSelectorRef(Name.getObjCSelector(), Record);
3869     break;
3870 
3871   case DeclarationName::CXXConstructorName:
3872   case DeclarationName::CXXDestructorName:
3873   case DeclarationName::CXXConversionFunctionName:
3874     AddTypeRef(Name.getCXXNameType(), Record);
3875     break;
3876 
3877   case DeclarationName::CXXOperatorName:
3878     Record.push_back(Name.getCXXOverloadedOperator());
3879     break;
3880 
3881   case DeclarationName::CXXLiteralOperatorName:
3882     AddIdentifierRef(Name.getCXXLiteralIdentifier(), Record);
3883     break;
3884 
3885   case DeclarationName::CXXUsingDirective:
3886     // No extra data to emit
3887     break;
3888   }
3889 }
3890 
3891 void ASTWriter::AddDeclarationNameLoc(const DeclarationNameLoc &DNLoc,
3892                                      DeclarationName Name, RecordDataImpl &Record) {
3893   switch (Name.getNameKind()) {
3894   case DeclarationName::CXXConstructorName:
3895   case DeclarationName::CXXDestructorName:
3896   case DeclarationName::CXXConversionFunctionName:
3897     AddTypeSourceInfo(DNLoc.NamedType.TInfo, Record);
3898     break;
3899 
3900   case DeclarationName::CXXOperatorName:
3901     AddSourceLocation(
3902        SourceLocation::getFromRawEncoding(DNLoc.CXXOperatorName.BeginOpNameLoc),
3903        Record);
3904     AddSourceLocation(
3905         SourceLocation::getFromRawEncoding(DNLoc.CXXOperatorName.EndOpNameLoc),
3906         Record);
3907     break;
3908 
3909   case DeclarationName::CXXLiteralOperatorName:
3910     AddSourceLocation(
3911      SourceLocation::getFromRawEncoding(DNLoc.CXXLiteralOperatorName.OpNameLoc),
3912      Record);
3913     break;
3914 
3915   case DeclarationName::Identifier:
3916   case DeclarationName::ObjCZeroArgSelector:
3917   case DeclarationName::ObjCOneArgSelector:
3918   case DeclarationName::ObjCMultiArgSelector:
3919   case DeclarationName::CXXUsingDirective:
3920     break;
3921   }
3922 }
3923 
3924 void ASTWriter::AddDeclarationNameInfo(const DeclarationNameInfo &NameInfo,
3925                                        RecordDataImpl &Record) {
3926   AddDeclarationName(NameInfo.getName(), Record);
3927   AddSourceLocation(NameInfo.getLoc(), Record);
3928   AddDeclarationNameLoc(NameInfo.getInfo(), NameInfo.getName(), Record);
3929 }
3930 
3931 void ASTWriter::AddQualifierInfo(const QualifierInfo &Info,
3932                                  RecordDataImpl &Record) {
3933   AddNestedNameSpecifierLoc(Info.QualifierLoc, Record);
3934   Record.push_back(Info.NumTemplParamLists);
3935   for (unsigned i=0, e=Info.NumTemplParamLists; i != e; ++i)
3936     AddTemplateParameterList(Info.TemplParamLists[i], Record);
3937 }
3938 
3939 void ASTWriter::AddNestedNameSpecifier(NestedNameSpecifier *NNS,
3940                                        RecordDataImpl &Record) {
3941   // Nested name specifiers usually aren't too long. I think that 8 would
3942   // typically accommodate the vast majority.
3943   SmallVector<NestedNameSpecifier *, 8> NestedNames;
3944 
3945   // Push each of the NNS's onto a stack for serialization in reverse order.
3946   while (NNS) {
3947     NestedNames.push_back(NNS);
3948     NNS = NNS->getPrefix();
3949   }
3950 
3951   Record.push_back(NestedNames.size());
3952   while(!NestedNames.empty()) {
3953     NNS = NestedNames.pop_back_val();
3954     NestedNameSpecifier::SpecifierKind Kind = NNS->getKind();
3955     Record.push_back(Kind);
3956     switch (Kind) {
3957     case NestedNameSpecifier::Identifier:
3958       AddIdentifierRef(NNS->getAsIdentifier(), Record);
3959       break;
3960 
3961     case NestedNameSpecifier::Namespace:
3962       AddDeclRef(NNS->getAsNamespace(), Record);
3963       break;
3964 
3965     case NestedNameSpecifier::NamespaceAlias:
3966       AddDeclRef(NNS->getAsNamespaceAlias(), Record);
3967       break;
3968 
3969     case NestedNameSpecifier::TypeSpec:
3970     case NestedNameSpecifier::TypeSpecWithTemplate:
3971       AddTypeRef(QualType(NNS->getAsType(), 0), Record);
3972       Record.push_back(Kind == NestedNameSpecifier::TypeSpecWithTemplate);
3973       break;
3974 
3975     case NestedNameSpecifier::Global:
3976       // Don't need to write an associated value.
3977       break;
3978     }
3979   }
3980 }
3981 
3982 void ASTWriter::AddNestedNameSpecifierLoc(NestedNameSpecifierLoc NNS,
3983                                           RecordDataImpl &Record) {
3984   // Nested name specifiers usually aren't too long. I think that 8 would
3985   // typically accommodate the vast majority.
3986   SmallVector<NestedNameSpecifierLoc , 8> NestedNames;
3987 
3988   // Push each of the nested-name-specifiers's onto a stack for
3989   // serialization in reverse order.
3990   while (NNS) {
3991     NestedNames.push_back(NNS);
3992     NNS = NNS.getPrefix();
3993   }
3994 
3995   Record.push_back(NestedNames.size());
3996   while(!NestedNames.empty()) {
3997     NNS = NestedNames.pop_back_val();
3998     NestedNameSpecifier::SpecifierKind Kind
3999       = NNS.getNestedNameSpecifier()->getKind();
4000     Record.push_back(Kind);
4001     switch (Kind) {
4002     case NestedNameSpecifier::Identifier:
4003       AddIdentifierRef(NNS.getNestedNameSpecifier()->getAsIdentifier(), Record);
4004       AddSourceRange(NNS.getLocalSourceRange(), Record);
4005       break;
4006 
4007     case NestedNameSpecifier::Namespace:
4008       AddDeclRef(NNS.getNestedNameSpecifier()->getAsNamespace(), Record);
4009       AddSourceRange(NNS.getLocalSourceRange(), Record);
4010       break;
4011 
4012     case NestedNameSpecifier::NamespaceAlias:
4013       AddDeclRef(NNS.getNestedNameSpecifier()->getAsNamespaceAlias(), Record);
4014       AddSourceRange(NNS.getLocalSourceRange(), Record);
4015       break;
4016 
4017     case NestedNameSpecifier::TypeSpec:
4018     case NestedNameSpecifier::TypeSpecWithTemplate:
4019       Record.push_back(Kind == NestedNameSpecifier::TypeSpecWithTemplate);
4020       AddTypeLoc(NNS.getTypeLoc(), Record);
4021       AddSourceLocation(NNS.getLocalSourceRange().getEnd(), Record);
4022       break;
4023 
4024     case NestedNameSpecifier::Global:
4025       AddSourceLocation(NNS.getLocalSourceRange().getEnd(), Record);
4026       break;
4027     }
4028   }
4029 }
4030 
4031 void ASTWriter::AddTemplateName(TemplateName Name, RecordDataImpl &Record) {
4032   TemplateName::NameKind Kind = Name.getKind();
4033   Record.push_back(Kind);
4034   switch (Kind) {
4035   case TemplateName::Template:
4036     AddDeclRef(Name.getAsTemplateDecl(), Record);
4037     break;
4038 
4039   case TemplateName::OverloadedTemplate: {
4040     OverloadedTemplateStorage *OvT = Name.getAsOverloadedTemplate();
4041     Record.push_back(OvT->size());
4042     for (OverloadedTemplateStorage::iterator I = OvT->begin(), E = OvT->end();
4043            I != E; ++I)
4044       AddDeclRef(*I, Record);
4045     break;
4046   }
4047 
4048   case TemplateName::QualifiedTemplate: {
4049     QualifiedTemplateName *QualT = Name.getAsQualifiedTemplateName();
4050     AddNestedNameSpecifier(QualT->getQualifier(), Record);
4051     Record.push_back(QualT->hasTemplateKeyword());
4052     AddDeclRef(QualT->getTemplateDecl(), Record);
4053     break;
4054   }
4055 
4056   case TemplateName::DependentTemplate: {
4057     DependentTemplateName *DepT = Name.getAsDependentTemplateName();
4058     AddNestedNameSpecifier(DepT->getQualifier(), Record);
4059     Record.push_back(DepT->isIdentifier());
4060     if (DepT->isIdentifier())
4061       AddIdentifierRef(DepT->getIdentifier(), Record);
4062     else
4063       Record.push_back(DepT->getOperator());
4064     break;
4065   }
4066 
4067   case TemplateName::SubstTemplateTemplateParm: {
4068     SubstTemplateTemplateParmStorage *subst
4069       = Name.getAsSubstTemplateTemplateParm();
4070     AddDeclRef(subst->getParameter(), Record);
4071     AddTemplateName(subst->getReplacement(), Record);
4072     break;
4073   }
4074 
4075   case TemplateName::SubstTemplateTemplateParmPack: {
4076     SubstTemplateTemplateParmPackStorage *SubstPack
4077       = Name.getAsSubstTemplateTemplateParmPack();
4078     AddDeclRef(SubstPack->getParameterPack(), Record);
4079     AddTemplateArgument(SubstPack->getArgumentPack(), Record);
4080     break;
4081   }
4082   }
4083 }
4084 
4085 void ASTWriter::AddTemplateArgument(const TemplateArgument &Arg,
4086                                     RecordDataImpl &Record) {
4087   Record.push_back(Arg.getKind());
4088   switch (Arg.getKind()) {
4089   case TemplateArgument::Null:
4090     break;
4091   case TemplateArgument::Type:
4092     AddTypeRef(Arg.getAsType(), Record);
4093     break;
4094   case TemplateArgument::Declaration:
4095     AddDeclRef(Arg.getAsDecl(), Record);
4096     break;
4097   case TemplateArgument::Integral:
4098     AddAPSInt(*Arg.getAsIntegral(), Record);
4099     AddTypeRef(Arg.getIntegralType(), Record);
4100     break;
4101   case TemplateArgument::Template:
4102     AddTemplateName(Arg.getAsTemplateOrTemplatePattern(), Record);
4103     break;
4104   case TemplateArgument::TemplateExpansion:
4105     AddTemplateName(Arg.getAsTemplateOrTemplatePattern(), Record);
4106     if (llvm::Optional<unsigned> NumExpansions = Arg.getNumTemplateExpansions())
4107       Record.push_back(*NumExpansions + 1);
4108     else
4109       Record.push_back(0);
4110     break;
4111   case TemplateArgument::Expression:
4112     AddStmt(Arg.getAsExpr());
4113     break;
4114   case TemplateArgument::Pack:
4115     Record.push_back(Arg.pack_size());
4116     for (TemplateArgument::pack_iterator I=Arg.pack_begin(), E=Arg.pack_end();
4117            I != E; ++I)
4118       AddTemplateArgument(*I, Record);
4119     break;
4120   }
4121 }
4122 
4123 void
4124 ASTWriter::AddTemplateParameterList(const TemplateParameterList *TemplateParams,
4125                                     RecordDataImpl &Record) {
4126   assert(TemplateParams && "No TemplateParams!");
4127   AddSourceLocation(TemplateParams->getTemplateLoc(), Record);
4128   AddSourceLocation(TemplateParams->getLAngleLoc(), Record);
4129   AddSourceLocation(TemplateParams->getRAngleLoc(), Record);
4130   Record.push_back(TemplateParams->size());
4131   for (TemplateParameterList::const_iterator
4132          P = TemplateParams->begin(), PEnd = TemplateParams->end();
4133          P != PEnd; ++P)
4134     AddDeclRef(*P, Record);
4135 }
4136 
4137 /// \brief Emit a template argument list.
4138 void
4139 ASTWriter::AddTemplateArgumentList(const TemplateArgumentList *TemplateArgs,
4140                                    RecordDataImpl &Record) {
4141   assert(TemplateArgs && "No TemplateArgs!");
4142   Record.push_back(TemplateArgs->size());
4143   for (int i=0, e = TemplateArgs->size(); i != e; ++i)
4144     AddTemplateArgument(TemplateArgs->get(i), Record);
4145 }
4146 
4147 
4148 void
4149 ASTWriter::AddUnresolvedSet(const UnresolvedSetImpl &Set, RecordDataImpl &Record) {
4150   Record.push_back(Set.size());
4151   for (UnresolvedSetImpl::const_iterator
4152          I = Set.begin(), E = Set.end(); I != E; ++I) {
4153     AddDeclRef(I.getDecl(), Record);
4154     Record.push_back(I.getAccess());
4155   }
4156 }
4157 
4158 void ASTWriter::AddCXXBaseSpecifier(const CXXBaseSpecifier &Base,
4159                                     RecordDataImpl &Record) {
4160   Record.push_back(Base.isVirtual());
4161   Record.push_back(Base.isBaseOfClass());
4162   Record.push_back(Base.getAccessSpecifierAsWritten());
4163   Record.push_back(Base.getInheritConstructors());
4164   AddTypeSourceInfo(Base.getTypeSourceInfo(), Record);
4165   AddSourceRange(Base.getSourceRange(), Record);
4166   AddSourceLocation(Base.isPackExpansion()? Base.getEllipsisLoc()
4167                                           : SourceLocation(),
4168                     Record);
4169 }
4170 
4171 void ASTWriter::FlushCXXBaseSpecifiers() {
4172   RecordData Record;
4173   for (unsigned I = 0, N = CXXBaseSpecifiersToWrite.size(); I != N; ++I) {
4174     Record.clear();
4175 
4176     // Record the offset of this base-specifier set.
4177     unsigned Index = CXXBaseSpecifiersToWrite[I].ID - 1;
4178     if (Index == CXXBaseSpecifiersOffsets.size())
4179       CXXBaseSpecifiersOffsets.push_back(Stream.GetCurrentBitNo());
4180     else {
4181       if (Index > CXXBaseSpecifiersOffsets.size())
4182         CXXBaseSpecifiersOffsets.resize(Index + 1);
4183       CXXBaseSpecifiersOffsets[Index] = Stream.GetCurrentBitNo();
4184     }
4185 
4186     const CXXBaseSpecifier *B = CXXBaseSpecifiersToWrite[I].Bases,
4187                         *BEnd = CXXBaseSpecifiersToWrite[I].BasesEnd;
4188     Record.push_back(BEnd - B);
4189     for (; B != BEnd; ++B)
4190       AddCXXBaseSpecifier(*B, Record);
4191     Stream.EmitRecord(serialization::DECL_CXX_BASE_SPECIFIERS, Record);
4192 
4193     // Flush any expressions that were written as part of the base specifiers.
4194     FlushStmts();
4195   }
4196 
4197   CXXBaseSpecifiersToWrite.clear();
4198 }
4199 
4200 void ASTWriter::AddCXXCtorInitializers(
4201                              const CXXCtorInitializer * const *CtorInitializers,
4202                              unsigned NumCtorInitializers,
4203                              RecordDataImpl &Record) {
4204   Record.push_back(NumCtorInitializers);
4205   for (unsigned i=0; i != NumCtorInitializers; ++i) {
4206     const CXXCtorInitializer *Init = CtorInitializers[i];
4207 
4208     if (Init->isBaseInitializer()) {
4209       Record.push_back(CTOR_INITIALIZER_BASE);
4210       AddTypeSourceInfo(Init->getTypeSourceInfo(), Record);
4211       Record.push_back(Init->isBaseVirtual());
4212     } else if (Init->isDelegatingInitializer()) {
4213       Record.push_back(CTOR_INITIALIZER_DELEGATING);
4214       AddTypeSourceInfo(Init->getTypeSourceInfo(), Record);
4215     } else if (Init->isMemberInitializer()){
4216       Record.push_back(CTOR_INITIALIZER_MEMBER);
4217       AddDeclRef(Init->getMember(), Record);
4218     } else {
4219       Record.push_back(CTOR_INITIALIZER_INDIRECT_MEMBER);
4220       AddDeclRef(Init->getIndirectMember(), Record);
4221     }
4222 
4223     AddSourceLocation(Init->getMemberLocation(), Record);
4224     AddStmt(Init->getInit());
4225     AddSourceLocation(Init->getLParenLoc(), Record);
4226     AddSourceLocation(Init->getRParenLoc(), Record);
4227     Record.push_back(Init->isWritten());
4228     if (Init->isWritten()) {
4229       Record.push_back(Init->getSourceOrder());
4230     } else {
4231       Record.push_back(Init->getNumArrayIndices());
4232       for (unsigned i=0, e=Init->getNumArrayIndices(); i != e; ++i)
4233         AddDeclRef(Init->getArrayIndex(i), Record);
4234     }
4235   }
4236 }
4237 
4238 void ASTWriter::AddCXXDefinitionData(const CXXRecordDecl *D, RecordDataImpl &Record) {
4239   assert(D->DefinitionData);
4240   struct CXXRecordDecl::DefinitionData &Data = *D->DefinitionData;
4241   Record.push_back(Data.UserDeclaredConstructor);
4242   Record.push_back(Data.UserDeclaredCopyConstructor);
4243   Record.push_back(Data.UserDeclaredMoveConstructor);
4244   Record.push_back(Data.UserDeclaredCopyAssignment);
4245   Record.push_back(Data.UserDeclaredMoveAssignment);
4246   Record.push_back(Data.UserDeclaredDestructor);
4247   Record.push_back(Data.Aggregate);
4248   Record.push_back(Data.PlainOldData);
4249   Record.push_back(Data.Empty);
4250   Record.push_back(Data.Polymorphic);
4251   Record.push_back(Data.Abstract);
4252   Record.push_back(Data.IsStandardLayout);
4253   Record.push_back(Data.HasNoNonEmptyBases);
4254   Record.push_back(Data.HasPrivateFields);
4255   Record.push_back(Data.HasProtectedFields);
4256   Record.push_back(Data.HasPublicFields);
4257   Record.push_back(Data.HasMutableFields);
4258   Record.push_back(Data.HasTrivialDefaultConstructor);
4259   Record.push_back(Data.HasConstexprNonCopyMoveConstructor);
4260   Record.push_back(Data.HasTrivialCopyConstructor);
4261   Record.push_back(Data.HasTrivialMoveConstructor);
4262   Record.push_back(Data.HasTrivialCopyAssignment);
4263   Record.push_back(Data.HasTrivialMoveAssignment);
4264   Record.push_back(Data.HasTrivialDestructor);
4265   Record.push_back(Data.HasNonLiteralTypeFieldsOrBases);
4266   Record.push_back(Data.ComputedVisibleConversions);
4267   Record.push_back(Data.UserProvidedDefaultConstructor);
4268   Record.push_back(Data.DeclaredDefaultConstructor);
4269   Record.push_back(Data.DeclaredCopyConstructor);
4270   Record.push_back(Data.DeclaredMoveConstructor);
4271   Record.push_back(Data.DeclaredCopyAssignment);
4272   Record.push_back(Data.DeclaredMoveAssignment);
4273   Record.push_back(Data.DeclaredDestructor);
4274   Record.push_back(Data.FailedImplicitMoveConstructor);
4275   Record.push_back(Data.FailedImplicitMoveAssignment);
4276 
4277   Record.push_back(Data.NumBases);
4278   if (Data.NumBases > 0)
4279     AddCXXBaseSpecifiersRef(Data.getBases(), Data.getBases() + Data.NumBases,
4280                             Record);
4281 
4282   // FIXME: Make VBases lazily computed when needed to avoid storing them.
4283   Record.push_back(Data.NumVBases);
4284   if (Data.NumVBases > 0)
4285     AddCXXBaseSpecifiersRef(Data.getVBases(), Data.getVBases() + Data.NumVBases,
4286                             Record);
4287 
4288   AddUnresolvedSet(Data.Conversions, Record);
4289   AddUnresolvedSet(Data.VisibleConversions, Record);
4290   // Data.Definition is the owning decl, no need to write it.
4291   AddDeclRef(Data.FirstFriend, Record);
4292 }
4293 
4294 void ASTWriter::ReaderInitialized(ASTReader *Reader) {
4295   assert(Reader && "Cannot remove chain");
4296   assert((!Chain || Chain == Reader) && "Cannot replace chain");
4297   assert(FirstDeclID == NextDeclID &&
4298          FirstTypeID == NextTypeID &&
4299          FirstIdentID == NextIdentID &&
4300          FirstSubmoduleID == NextSubmoduleID &&
4301          FirstSelectorID == NextSelectorID &&
4302          "Setting chain after writing has started.");
4303 
4304   Chain = Reader;
4305 
4306   FirstDeclID = NUM_PREDEF_DECL_IDS + Chain->getTotalNumDecls();
4307   FirstTypeID = NUM_PREDEF_TYPE_IDS + Chain->getTotalNumTypes();
4308   FirstIdentID = NUM_PREDEF_IDENT_IDS + Chain->getTotalNumIdentifiers();
4309   FirstSubmoduleID = NUM_PREDEF_SUBMODULE_IDS + Chain->getTotalNumSubmodules();
4310   FirstSelectorID = NUM_PREDEF_SELECTOR_IDS + Chain->getTotalNumSelectors();
4311   NextDeclID = FirstDeclID;
4312   NextTypeID = FirstTypeID;
4313   NextIdentID = FirstIdentID;
4314   NextSelectorID = FirstSelectorID;
4315   NextSubmoduleID = FirstSubmoduleID;
4316 }
4317 
4318 void ASTWriter::IdentifierRead(IdentID ID, IdentifierInfo *II) {
4319   IdentifierIDs[II] = ID;
4320   if (II->hasMacroDefinition())
4321     DeserializedMacroNames.push_back(II);
4322 }
4323 
4324 void ASTWriter::TypeRead(TypeIdx Idx, QualType T) {
4325   // Always take the highest-numbered type index. This copes with an interesting
4326   // case for chained AST writing where we schedule writing the type and then,
4327   // later, deserialize the type from another AST. In this case, we want to
4328   // keep the higher-numbered entry so that we can properly write it out to
4329   // the AST file.
4330   TypeIdx &StoredIdx = TypeIdxs[T];
4331   if (Idx.getIndex() >= StoredIdx.getIndex())
4332     StoredIdx = Idx;
4333 }
4334 
4335 void ASTWriter::SelectorRead(SelectorID ID, Selector S) {
4336   SelectorIDs[S] = ID;
4337 }
4338 
4339 void ASTWriter::MacroDefinitionRead(serialization::PreprocessedEntityID ID,
4340                                     MacroDefinition *MD) {
4341   assert(MacroDefinitions.find(MD) == MacroDefinitions.end());
4342   MacroDefinitions[MD] = ID;
4343 }
4344 
4345 void ASTWriter::MacroVisible(IdentifierInfo *II) {
4346   DeserializedMacroNames.push_back(II);
4347 }
4348 
4349 void ASTWriter::ModuleRead(serialization::SubmoduleID ID, Module *Mod) {
4350   assert(SubmoduleIDs.find(Mod) == SubmoduleIDs.end());
4351   SubmoduleIDs[Mod] = ID;
4352 }
4353 
4354 void ASTWriter::CompletedTagDefinition(const TagDecl *D) {
4355   assert(D->isCompleteDefinition());
4356   assert(!WritingAST && "Already writing the AST!");
4357   if (const CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(D)) {
4358     // We are interested when a PCH decl is modified.
4359     if (RD->isFromASTFile()) {
4360       // A forward reference was mutated into a definition. Rewrite it.
4361       // FIXME: This happens during template instantiation, should we
4362       // have created a new definition decl instead ?
4363       RewriteDecl(RD);
4364     }
4365   }
4366 }
4367 void ASTWriter::AddedVisibleDecl(const DeclContext *DC, const Decl *D) {
4368   assert(!WritingAST && "Already writing the AST!");
4369 
4370   // TU and namespaces are handled elsewhere.
4371   if (isa<TranslationUnitDecl>(DC) || isa<NamespaceDecl>(DC))
4372     return;
4373 
4374   if (!(!D->isFromASTFile() && cast<Decl>(DC)->isFromASTFile()))
4375     return; // Not a source decl added to a DeclContext from PCH.
4376 
4377   AddUpdatedDeclContext(DC);
4378 }
4379 
4380 void ASTWriter::AddedCXXImplicitMember(const CXXRecordDecl *RD, const Decl *D) {
4381   assert(!WritingAST && "Already writing the AST!");
4382   assert(D->isImplicit());
4383   if (!(!D->isFromASTFile() && RD->isFromASTFile()))
4384     return; // Not a source member added to a class from PCH.
4385   if (!isa<CXXMethodDecl>(D))
4386     return; // We are interested in lazily declared implicit methods.
4387 
4388   // A decl coming from PCH was modified.
4389   assert(RD->isCompleteDefinition());
4390   UpdateRecord &Record = DeclUpdates[RD];
4391   Record.push_back(UPD_CXX_ADDED_IMPLICIT_MEMBER);
4392   Record.push_back(reinterpret_cast<uint64_t>(D));
4393 }
4394 
4395 void ASTWriter::AddedCXXTemplateSpecialization(const ClassTemplateDecl *TD,
4396                                      const ClassTemplateSpecializationDecl *D) {
4397   // The specializations set is kept in the canonical template.
4398   assert(!WritingAST && "Already writing the AST!");
4399   TD = TD->getCanonicalDecl();
4400   if (!(!D->isFromASTFile() && TD->isFromASTFile()))
4401     return; // Not a source specialization added to a template from PCH.
4402 
4403   UpdateRecord &Record = DeclUpdates[TD];
4404   Record.push_back(UPD_CXX_ADDED_TEMPLATE_SPECIALIZATION);
4405   Record.push_back(reinterpret_cast<uint64_t>(D));
4406 }
4407 
4408 void ASTWriter::AddedCXXTemplateSpecialization(const FunctionTemplateDecl *TD,
4409                                                const FunctionDecl *D) {
4410   // The specializations set is kept in the canonical template.
4411   assert(!WritingAST && "Already writing the AST!");
4412   TD = TD->getCanonicalDecl();
4413   if (!(!D->isFromASTFile() && TD->isFromASTFile()))
4414     return; // Not a source specialization added to a template from PCH.
4415 
4416   UpdateRecord &Record = DeclUpdates[TD];
4417   Record.push_back(UPD_CXX_ADDED_TEMPLATE_SPECIALIZATION);
4418   Record.push_back(reinterpret_cast<uint64_t>(D));
4419 }
4420 
4421 void ASTWriter::CompletedImplicitDefinition(const FunctionDecl *D) {
4422   assert(!WritingAST && "Already writing the AST!");
4423   if (!D->isFromASTFile())
4424     return; // Declaration not imported from PCH.
4425 
4426   // Implicit decl from a PCH was defined.
4427   // FIXME: Should implicit definition be a separate FunctionDecl?
4428   RewriteDecl(D);
4429 }
4430 
4431 void ASTWriter::StaticDataMemberInstantiated(const VarDecl *D) {
4432   assert(!WritingAST && "Already writing the AST!");
4433   if (!D->isFromASTFile())
4434     return;
4435 
4436   // Since the actual instantiation is delayed, this really means that we need
4437   // to update the instantiation location.
4438   UpdateRecord &Record = DeclUpdates[D];
4439   Record.push_back(UPD_CXX_INSTANTIATED_STATIC_DATA_MEMBER);
4440   AddSourceLocation(
4441       D->getMemberSpecializationInfo()->getPointOfInstantiation(), Record);
4442 }
4443 
4444 void ASTWriter::AddedObjCCategoryToInterface(const ObjCCategoryDecl *CatD,
4445                                              const ObjCInterfaceDecl *IFD) {
4446   assert(!WritingAST && "Already writing the AST!");
4447   if (!IFD->isFromASTFile())
4448     return; // Declaration not imported from PCH.
4449   if (CatD->getNextClassCategory() &&
4450       !CatD->getNextClassCategory()->isFromASTFile())
4451     return; // We already recorded that the tail of a category chain should be
4452             // attached to an interface.
4453 
4454   ChainedObjCCategoriesData Data =  { IFD, CatD };
4455   LocalChainedObjCCategories.push_back(Data);
4456 }
4457 
4458 
4459 void ASTWriter::AddedObjCPropertyInClassExtension(const ObjCPropertyDecl *Prop,
4460                                           const ObjCPropertyDecl *OrigProp,
4461                                           const ObjCCategoryDecl *ClassExt) {
4462   const ObjCInterfaceDecl *D = ClassExt->getClassInterface();
4463   if (!D)
4464     return;
4465 
4466   assert(!WritingAST && "Already writing the AST!");
4467   if (!D->isFromASTFile())
4468     return; // Declaration not imported from PCH.
4469 
4470   RewriteDecl(D);
4471 }
4472 
4473