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/AST/ASTContext.h"
17 #include "clang/AST/Decl.h"
18 #include "clang/AST/DeclContextInternals.h"
19 #include "clang/AST/DeclFriend.h"
20 #include "clang/AST/DeclLookups.h"
21 #include "clang/AST/DeclTemplate.h"
22 #include "clang/AST/Expr.h"
23 #include "clang/AST/ExprCXX.h"
24 #include "clang/AST/Type.h"
25 #include "clang/AST/TypeLocVisitor.h"
26 #include "clang/Basic/FileManager.h"
27 #include "clang/Basic/FileSystemStatCache.h"
28 #include "clang/Basic/SourceManager.h"
29 #include "clang/Basic/SourceManagerInternals.h"
30 #include "clang/Basic/TargetInfo.h"
31 #include "clang/Basic/TargetOptions.h"
32 #include "clang/Basic/Version.h"
33 #include "clang/Basic/VersionTuple.h"
34 #include "clang/Lex/HeaderSearch.h"
35 #include "clang/Lex/HeaderSearchOptions.h"
36 #include "clang/Lex/MacroInfo.h"
37 #include "clang/Lex/PreprocessingRecord.h"
38 #include "clang/Lex/Preprocessor.h"
39 #include "clang/Lex/PreprocessorOptions.h"
40 #include "clang/Sema/IdentifierResolver.h"
41 #include "clang/Sema/Sema.h"
42 #include "clang/Serialization/ASTReader.h"
43 #include "llvm/ADT/APFloat.h"
44 #include "llvm/ADT/APInt.h"
45 #include "llvm/ADT/Hashing.h"
46 #include "llvm/ADT/StringExtras.h"
47 #include "llvm/Bitcode/BitstreamWriter.h"
48 #include "llvm/Support/EndianStream.h"
49 #include "llvm/Support/FileSystem.h"
50 #include "llvm/Support/MemoryBuffer.h"
51 #include "llvm/Support/OnDiskHashTable.h"
52 #include "llvm/Support/Path.h"
53 #include <algorithm>
54 #include <cstdio>
55 #include <string.h>
56 #include <utility>
57 using namespace clang;
58 using namespace clang::serialization;
59 
60 template <typename T, typename Allocator>
61 static StringRef data(const std::vector<T, Allocator> &v) {
62   if (v.empty()) return StringRef();
63   return StringRef(reinterpret_cast<const char*>(&v[0]),
64                          sizeof(T) * v.size());
65 }
66 
67 template <typename T>
68 static StringRef data(const SmallVectorImpl<T> &v) {
69   return StringRef(reinterpret_cast<const char*>(v.data()),
70                          sizeof(T) * v.size());
71 }
72 
73 //===----------------------------------------------------------------------===//
74 // Type serialization
75 //===----------------------------------------------------------------------===//
76 
77 namespace {
78   class ASTTypeWriter {
79     ASTWriter &Writer;
80     ASTWriter::RecordDataImpl &Record;
81 
82   public:
83     /// \brief Type code that corresponds to the record generated.
84     TypeCode Code;
85 
86     ASTTypeWriter(ASTWriter &Writer, ASTWriter::RecordDataImpl &Record)
87       : Writer(Writer), Record(Record), Code(TYPE_EXT_QUAL) { }
88 
89     void VisitArrayType(const ArrayType *T);
90     void VisitFunctionType(const FunctionType *T);
91     void VisitTagType(const TagType *T);
92 
93 #define TYPE(Class, Base) void Visit##Class##Type(const Class##Type *T);
94 #define ABSTRACT_TYPE(Class, Base)
95 #include "clang/AST/TypeNodes.def"
96   };
97 }
98 
99 void ASTTypeWriter::VisitBuiltinType(const BuiltinType *T) {
100   llvm_unreachable("Built-in types are never serialized");
101 }
102 
103 void ASTTypeWriter::VisitComplexType(const ComplexType *T) {
104   Writer.AddTypeRef(T->getElementType(), Record);
105   Code = TYPE_COMPLEX;
106 }
107 
108 void ASTTypeWriter::VisitPointerType(const PointerType *T) {
109   Writer.AddTypeRef(T->getPointeeType(), Record);
110   Code = TYPE_POINTER;
111 }
112 
113 void ASTTypeWriter::VisitDecayedType(const DecayedType *T) {
114   Writer.AddTypeRef(T->getOriginalType(), Record);
115   Code = TYPE_DECAYED;
116 }
117 
118 void ASTTypeWriter::VisitAdjustedType(const AdjustedType *T) {
119   Writer.AddTypeRef(T->getOriginalType(), Record);
120   Writer.AddTypeRef(T->getAdjustedType(), Record);
121   Code = TYPE_ADJUSTED;
122 }
123 
124 void ASTTypeWriter::VisitBlockPointerType(const BlockPointerType *T) {
125   Writer.AddTypeRef(T->getPointeeType(), Record);
126   Code = TYPE_BLOCK_POINTER;
127 }
128 
129 void ASTTypeWriter::VisitLValueReferenceType(const LValueReferenceType *T) {
130   Writer.AddTypeRef(T->getPointeeTypeAsWritten(), Record);
131   Record.push_back(T->isSpelledAsLValue());
132   Code = TYPE_LVALUE_REFERENCE;
133 }
134 
135 void ASTTypeWriter::VisitRValueReferenceType(const RValueReferenceType *T) {
136   Writer.AddTypeRef(T->getPointeeTypeAsWritten(), Record);
137   Code = TYPE_RVALUE_REFERENCE;
138 }
139 
140 void ASTTypeWriter::VisitMemberPointerType(const MemberPointerType *T) {
141   Writer.AddTypeRef(T->getPointeeType(), Record);
142   Writer.AddTypeRef(QualType(T->getClass(), 0), Record);
143   Code = TYPE_MEMBER_POINTER;
144 }
145 
146 void ASTTypeWriter::VisitArrayType(const ArrayType *T) {
147   Writer.AddTypeRef(T->getElementType(), Record);
148   Record.push_back(T->getSizeModifier()); // FIXME: stable values
149   Record.push_back(T->getIndexTypeCVRQualifiers()); // FIXME: stable values
150 }
151 
152 void ASTTypeWriter::VisitConstantArrayType(const ConstantArrayType *T) {
153   VisitArrayType(T);
154   Writer.AddAPInt(T->getSize(), Record);
155   Code = TYPE_CONSTANT_ARRAY;
156 }
157 
158 void ASTTypeWriter::VisitIncompleteArrayType(const IncompleteArrayType *T) {
159   VisitArrayType(T);
160   Code = TYPE_INCOMPLETE_ARRAY;
161 }
162 
163 void ASTTypeWriter::VisitVariableArrayType(const VariableArrayType *T) {
164   VisitArrayType(T);
165   Writer.AddSourceLocation(T->getLBracketLoc(), Record);
166   Writer.AddSourceLocation(T->getRBracketLoc(), Record);
167   Writer.AddStmt(T->getSizeExpr());
168   Code = TYPE_VARIABLE_ARRAY;
169 }
170 
171 void ASTTypeWriter::VisitVectorType(const VectorType *T) {
172   Writer.AddTypeRef(T->getElementType(), Record);
173   Record.push_back(T->getNumElements());
174   Record.push_back(T->getVectorKind());
175   Code = TYPE_VECTOR;
176 }
177 
178 void ASTTypeWriter::VisitExtVectorType(const ExtVectorType *T) {
179   VisitVectorType(T);
180   Code = TYPE_EXT_VECTOR;
181 }
182 
183 void ASTTypeWriter::VisitFunctionType(const FunctionType *T) {
184   Writer.AddTypeRef(T->getReturnType(), Record);
185   FunctionType::ExtInfo C = T->getExtInfo();
186   Record.push_back(C.getNoReturn());
187   Record.push_back(C.getHasRegParm());
188   Record.push_back(C.getRegParm());
189   // FIXME: need to stabilize encoding of calling convention...
190   Record.push_back(C.getCC());
191   Record.push_back(C.getProducesResult());
192 }
193 
194 void ASTTypeWriter::VisitFunctionNoProtoType(const FunctionNoProtoType *T) {
195   VisitFunctionType(T);
196   Code = TYPE_FUNCTION_NO_PROTO;
197 }
198 
199 static void addExceptionSpec(ASTWriter &Writer, const FunctionProtoType *T,
200                              ASTWriter::RecordDataImpl &Record) {
201   Record.push_back(T->getExceptionSpecType());
202   if (T->getExceptionSpecType() == EST_Dynamic) {
203     Record.push_back(T->getNumExceptions());
204     for (unsigned I = 0, N = T->getNumExceptions(); I != N; ++I)
205       Writer.AddTypeRef(T->getExceptionType(I), Record);
206   } else if (T->getExceptionSpecType() == EST_ComputedNoexcept) {
207     Writer.AddStmt(T->getNoexceptExpr());
208   } else if (T->getExceptionSpecType() == EST_Uninstantiated) {
209     Writer.AddDeclRef(T->getExceptionSpecDecl(), Record);
210     Writer.AddDeclRef(T->getExceptionSpecTemplate(), Record);
211   } else if (T->getExceptionSpecType() == EST_Unevaluated) {
212     Writer.AddDeclRef(T->getExceptionSpecDecl(), Record);
213   }
214 }
215 
216 void ASTTypeWriter::VisitFunctionProtoType(const FunctionProtoType *T) {
217   VisitFunctionType(T);
218   Record.push_back(T->getNumParams());
219   for (unsigned I = 0, N = T->getNumParams(); I != N; ++I)
220     Writer.AddTypeRef(T->getParamType(I), Record);
221   Record.push_back(T->isVariadic());
222   Record.push_back(T->hasTrailingReturn());
223   Record.push_back(T->getTypeQuals());
224   Record.push_back(static_cast<unsigned>(T->getRefQualifier()));
225   addExceptionSpec(Writer, T, Record);
226   Code = TYPE_FUNCTION_PROTO;
227 }
228 
229 void ASTTypeWriter::VisitUnresolvedUsingType(const UnresolvedUsingType *T) {
230   Writer.AddDeclRef(T->getDecl(), Record);
231   Code = TYPE_UNRESOLVED_USING;
232 }
233 
234 void ASTTypeWriter::VisitTypedefType(const TypedefType *T) {
235   Writer.AddDeclRef(T->getDecl(), Record);
236   assert(!T->isCanonicalUnqualified() && "Invalid typedef ?");
237   Writer.AddTypeRef(T->getCanonicalTypeInternal(), Record);
238   Code = TYPE_TYPEDEF;
239 }
240 
241 void ASTTypeWriter::VisitTypeOfExprType(const TypeOfExprType *T) {
242   Writer.AddStmt(T->getUnderlyingExpr());
243   Code = TYPE_TYPEOF_EXPR;
244 }
245 
246 void ASTTypeWriter::VisitTypeOfType(const TypeOfType *T) {
247   Writer.AddTypeRef(T->getUnderlyingType(), Record);
248   Code = TYPE_TYPEOF;
249 }
250 
251 void ASTTypeWriter::VisitDecltypeType(const DecltypeType *T) {
252   Writer.AddTypeRef(T->getUnderlyingType(), Record);
253   Writer.AddStmt(T->getUnderlyingExpr());
254   Code = TYPE_DECLTYPE;
255 }
256 
257 void ASTTypeWriter::VisitUnaryTransformType(const UnaryTransformType *T) {
258   Writer.AddTypeRef(T->getBaseType(), Record);
259   Writer.AddTypeRef(T->getUnderlyingType(), Record);
260   Record.push_back(T->getUTTKind());
261   Code = TYPE_UNARY_TRANSFORM;
262 }
263 
264 void ASTTypeWriter::VisitAutoType(const AutoType *T) {
265   Writer.AddTypeRef(T->getDeducedType(), Record);
266   Record.push_back(T->isDecltypeAuto());
267   if (T->getDeducedType().isNull())
268     Record.push_back(T->isDependentType());
269   Code = TYPE_AUTO;
270 }
271 
272 void ASTTypeWriter::VisitTagType(const TagType *T) {
273   Record.push_back(T->isDependentType());
274   Writer.AddDeclRef(T->getDecl()->getCanonicalDecl(), Record);
275   assert(!T->isBeingDefined() &&
276          "Cannot serialize in the middle of a type definition");
277 }
278 
279 void ASTTypeWriter::VisitRecordType(const RecordType *T) {
280   VisitTagType(T);
281   Code = TYPE_RECORD;
282 }
283 
284 void ASTTypeWriter::VisitEnumType(const EnumType *T) {
285   VisitTagType(T);
286   Code = TYPE_ENUM;
287 }
288 
289 void ASTTypeWriter::VisitAttributedType(const AttributedType *T) {
290   Writer.AddTypeRef(T->getModifiedType(), Record);
291   Writer.AddTypeRef(T->getEquivalentType(), Record);
292   Record.push_back(T->getAttrKind());
293   Code = TYPE_ATTRIBUTED;
294 }
295 
296 void
297 ASTTypeWriter::VisitSubstTemplateTypeParmType(
298                                         const SubstTemplateTypeParmType *T) {
299   Writer.AddTypeRef(QualType(T->getReplacedParameter(), 0), Record);
300   Writer.AddTypeRef(T->getReplacementType(), Record);
301   Code = TYPE_SUBST_TEMPLATE_TYPE_PARM;
302 }
303 
304 void
305 ASTTypeWriter::VisitSubstTemplateTypeParmPackType(
306                                       const SubstTemplateTypeParmPackType *T) {
307   Writer.AddTypeRef(QualType(T->getReplacedParameter(), 0), Record);
308   Writer.AddTemplateArgument(T->getArgumentPack(), Record);
309   Code = TYPE_SUBST_TEMPLATE_TYPE_PARM_PACK;
310 }
311 
312 void
313 ASTTypeWriter::VisitTemplateSpecializationType(
314                                        const TemplateSpecializationType *T) {
315   Record.push_back(T->isDependentType());
316   Writer.AddTemplateName(T->getTemplateName(), Record);
317   Record.push_back(T->getNumArgs());
318   for (TemplateSpecializationType::iterator ArgI = T->begin(), ArgE = T->end();
319          ArgI != ArgE; ++ArgI)
320     Writer.AddTemplateArgument(*ArgI, Record);
321   Writer.AddTypeRef(T->isTypeAlias() ? T->getAliasedType() :
322                     T->isCanonicalUnqualified() ? QualType()
323                                                 : T->getCanonicalTypeInternal(),
324                     Record);
325   Code = TYPE_TEMPLATE_SPECIALIZATION;
326 }
327 
328 void
329 ASTTypeWriter::VisitDependentSizedArrayType(const DependentSizedArrayType *T) {
330   VisitArrayType(T);
331   Writer.AddStmt(T->getSizeExpr());
332   Writer.AddSourceRange(T->getBracketsRange(), Record);
333   Code = TYPE_DEPENDENT_SIZED_ARRAY;
334 }
335 
336 void
337 ASTTypeWriter::VisitDependentSizedExtVectorType(
338                                         const DependentSizedExtVectorType *T) {
339   // FIXME: Serialize this type (C++ only)
340   llvm_unreachable("Cannot serialize dependent sized extended vector types");
341 }
342 
343 void
344 ASTTypeWriter::VisitTemplateTypeParmType(const TemplateTypeParmType *T) {
345   Record.push_back(T->getDepth());
346   Record.push_back(T->getIndex());
347   Record.push_back(T->isParameterPack());
348   Writer.AddDeclRef(T->getDecl(), Record);
349   Code = TYPE_TEMPLATE_TYPE_PARM;
350 }
351 
352 void
353 ASTTypeWriter::VisitDependentNameType(const DependentNameType *T) {
354   Record.push_back(T->getKeyword());
355   Writer.AddNestedNameSpecifier(T->getQualifier(), Record);
356   Writer.AddIdentifierRef(T->getIdentifier(), Record);
357   Writer.AddTypeRef(T->isCanonicalUnqualified() ? QualType()
358                                                 : T->getCanonicalTypeInternal(),
359                     Record);
360   Code = TYPE_DEPENDENT_NAME;
361 }
362 
363 void
364 ASTTypeWriter::VisitDependentTemplateSpecializationType(
365                                 const DependentTemplateSpecializationType *T) {
366   Record.push_back(T->getKeyword());
367   Writer.AddNestedNameSpecifier(T->getQualifier(), Record);
368   Writer.AddIdentifierRef(T->getIdentifier(), Record);
369   Record.push_back(T->getNumArgs());
370   for (DependentTemplateSpecializationType::iterator
371          I = T->begin(), E = T->end(); I != E; ++I)
372     Writer.AddTemplateArgument(*I, Record);
373   Code = TYPE_DEPENDENT_TEMPLATE_SPECIALIZATION;
374 }
375 
376 void ASTTypeWriter::VisitPackExpansionType(const PackExpansionType *T) {
377   Writer.AddTypeRef(T->getPattern(), Record);
378   if (Optional<unsigned> NumExpansions = T->getNumExpansions())
379     Record.push_back(*NumExpansions + 1);
380   else
381     Record.push_back(0);
382   Code = TYPE_PACK_EXPANSION;
383 }
384 
385 void ASTTypeWriter::VisitParenType(const ParenType *T) {
386   Writer.AddTypeRef(T->getInnerType(), Record);
387   Code = TYPE_PAREN;
388 }
389 
390 void ASTTypeWriter::VisitElaboratedType(const ElaboratedType *T) {
391   Record.push_back(T->getKeyword());
392   Writer.AddNestedNameSpecifier(T->getQualifier(), Record);
393   Writer.AddTypeRef(T->getNamedType(), Record);
394   Code = TYPE_ELABORATED;
395 }
396 
397 void ASTTypeWriter::VisitInjectedClassNameType(const InjectedClassNameType *T) {
398   Writer.AddDeclRef(T->getDecl()->getCanonicalDecl(), Record);
399   Writer.AddTypeRef(T->getInjectedSpecializationType(), Record);
400   Code = TYPE_INJECTED_CLASS_NAME;
401 }
402 
403 void ASTTypeWriter::VisitObjCInterfaceType(const ObjCInterfaceType *T) {
404   Writer.AddDeclRef(T->getDecl()->getCanonicalDecl(), Record);
405   Code = TYPE_OBJC_INTERFACE;
406 }
407 
408 void ASTTypeWriter::VisitObjCObjectType(const ObjCObjectType *T) {
409   Writer.AddTypeRef(T->getBaseType(), Record);
410   Record.push_back(T->getNumProtocols());
411   for (const auto *I : T->quals())
412     Writer.AddDeclRef(I, Record);
413   Code = TYPE_OBJC_OBJECT;
414 }
415 
416 void
417 ASTTypeWriter::VisitObjCObjectPointerType(const ObjCObjectPointerType *T) {
418   Writer.AddTypeRef(T->getPointeeType(), Record);
419   Code = TYPE_OBJC_OBJECT_POINTER;
420 }
421 
422 void
423 ASTTypeWriter::VisitAtomicType(const AtomicType *T) {
424   Writer.AddTypeRef(T->getValueType(), Record);
425   Code = TYPE_ATOMIC;
426 }
427 
428 namespace {
429 
430 class TypeLocWriter : public TypeLocVisitor<TypeLocWriter> {
431   ASTWriter &Writer;
432   ASTWriter::RecordDataImpl &Record;
433 
434 public:
435   TypeLocWriter(ASTWriter &Writer, ASTWriter::RecordDataImpl &Record)
436     : Writer(Writer), Record(Record) { }
437 
438 #define ABSTRACT_TYPELOC(CLASS, PARENT)
439 #define TYPELOC(CLASS, PARENT) \
440     void Visit##CLASS##TypeLoc(CLASS##TypeLoc TyLoc);
441 #include "clang/AST/TypeLocNodes.def"
442 
443   void VisitArrayTypeLoc(ArrayTypeLoc TyLoc);
444   void VisitFunctionTypeLoc(FunctionTypeLoc TyLoc);
445 };
446 
447 }
448 
449 void TypeLocWriter::VisitQualifiedTypeLoc(QualifiedTypeLoc TL) {
450   // nothing to do
451 }
452 void TypeLocWriter::VisitBuiltinTypeLoc(BuiltinTypeLoc TL) {
453   Writer.AddSourceLocation(TL.getBuiltinLoc(), Record);
454   if (TL.needsExtraLocalData()) {
455     Record.push_back(TL.getWrittenTypeSpec());
456     Record.push_back(TL.getWrittenSignSpec());
457     Record.push_back(TL.getWrittenWidthSpec());
458     Record.push_back(TL.hasModeAttr());
459   }
460 }
461 void TypeLocWriter::VisitComplexTypeLoc(ComplexTypeLoc TL) {
462   Writer.AddSourceLocation(TL.getNameLoc(), Record);
463 }
464 void TypeLocWriter::VisitPointerTypeLoc(PointerTypeLoc TL) {
465   Writer.AddSourceLocation(TL.getStarLoc(), Record);
466 }
467 void TypeLocWriter::VisitDecayedTypeLoc(DecayedTypeLoc TL) {
468   // nothing to do
469 }
470 void TypeLocWriter::VisitAdjustedTypeLoc(AdjustedTypeLoc TL) {
471   // nothing to do
472 }
473 void TypeLocWriter::VisitBlockPointerTypeLoc(BlockPointerTypeLoc TL) {
474   Writer.AddSourceLocation(TL.getCaretLoc(), Record);
475 }
476 void TypeLocWriter::VisitLValueReferenceTypeLoc(LValueReferenceTypeLoc TL) {
477   Writer.AddSourceLocation(TL.getAmpLoc(), Record);
478 }
479 void TypeLocWriter::VisitRValueReferenceTypeLoc(RValueReferenceTypeLoc TL) {
480   Writer.AddSourceLocation(TL.getAmpAmpLoc(), Record);
481 }
482 void TypeLocWriter::VisitMemberPointerTypeLoc(MemberPointerTypeLoc TL) {
483   Writer.AddSourceLocation(TL.getStarLoc(), Record);
484   Writer.AddTypeSourceInfo(TL.getClassTInfo(), Record);
485 }
486 void TypeLocWriter::VisitArrayTypeLoc(ArrayTypeLoc TL) {
487   Writer.AddSourceLocation(TL.getLBracketLoc(), Record);
488   Writer.AddSourceLocation(TL.getRBracketLoc(), Record);
489   Record.push_back(TL.getSizeExpr() ? 1 : 0);
490   if (TL.getSizeExpr())
491     Writer.AddStmt(TL.getSizeExpr());
492 }
493 void TypeLocWriter::VisitConstantArrayTypeLoc(ConstantArrayTypeLoc TL) {
494   VisitArrayTypeLoc(TL);
495 }
496 void TypeLocWriter::VisitIncompleteArrayTypeLoc(IncompleteArrayTypeLoc TL) {
497   VisitArrayTypeLoc(TL);
498 }
499 void TypeLocWriter::VisitVariableArrayTypeLoc(VariableArrayTypeLoc TL) {
500   VisitArrayTypeLoc(TL);
501 }
502 void TypeLocWriter::VisitDependentSizedArrayTypeLoc(
503                                             DependentSizedArrayTypeLoc TL) {
504   VisitArrayTypeLoc(TL);
505 }
506 void TypeLocWriter::VisitDependentSizedExtVectorTypeLoc(
507                                         DependentSizedExtVectorTypeLoc TL) {
508   Writer.AddSourceLocation(TL.getNameLoc(), Record);
509 }
510 void TypeLocWriter::VisitVectorTypeLoc(VectorTypeLoc TL) {
511   Writer.AddSourceLocation(TL.getNameLoc(), Record);
512 }
513 void TypeLocWriter::VisitExtVectorTypeLoc(ExtVectorTypeLoc TL) {
514   Writer.AddSourceLocation(TL.getNameLoc(), Record);
515 }
516 void TypeLocWriter::VisitFunctionTypeLoc(FunctionTypeLoc TL) {
517   Writer.AddSourceLocation(TL.getLocalRangeBegin(), Record);
518   Writer.AddSourceLocation(TL.getLParenLoc(), Record);
519   Writer.AddSourceLocation(TL.getRParenLoc(), Record);
520   Writer.AddSourceLocation(TL.getLocalRangeEnd(), Record);
521   for (unsigned i = 0, e = TL.getNumParams(); i != e; ++i)
522     Writer.AddDeclRef(TL.getParam(i), Record);
523 }
524 void TypeLocWriter::VisitFunctionProtoTypeLoc(FunctionProtoTypeLoc TL) {
525   VisitFunctionTypeLoc(TL);
526 }
527 void TypeLocWriter::VisitFunctionNoProtoTypeLoc(FunctionNoProtoTypeLoc TL) {
528   VisitFunctionTypeLoc(TL);
529 }
530 void TypeLocWriter::VisitUnresolvedUsingTypeLoc(UnresolvedUsingTypeLoc TL) {
531   Writer.AddSourceLocation(TL.getNameLoc(), Record);
532 }
533 void TypeLocWriter::VisitTypedefTypeLoc(TypedefTypeLoc TL) {
534   Writer.AddSourceLocation(TL.getNameLoc(), Record);
535 }
536 void TypeLocWriter::VisitTypeOfExprTypeLoc(TypeOfExprTypeLoc TL) {
537   Writer.AddSourceLocation(TL.getTypeofLoc(), Record);
538   Writer.AddSourceLocation(TL.getLParenLoc(), Record);
539   Writer.AddSourceLocation(TL.getRParenLoc(), Record);
540 }
541 void TypeLocWriter::VisitTypeOfTypeLoc(TypeOfTypeLoc TL) {
542   Writer.AddSourceLocation(TL.getTypeofLoc(), Record);
543   Writer.AddSourceLocation(TL.getLParenLoc(), Record);
544   Writer.AddSourceLocation(TL.getRParenLoc(), Record);
545   Writer.AddTypeSourceInfo(TL.getUnderlyingTInfo(), Record);
546 }
547 void TypeLocWriter::VisitDecltypeTypeLoc(DecltypeTypeLoc TL) {
548   Writer.AddSourceLocation(TL.getNameLoc(), Record);
549 }
550 void TypeLocWriter::VisitUnaryTransformTypeLoc(UnaryTransformTypeLoc TL) {
551   Writer.AddSourceLocation(TL.getKWLoc(), Record);
552   Writer.AddSourceLocation(TL.getLParenLoc(), Record);
553   Writer.AddSourceLocation(TL.getRParenLoc(), Record);
554   Writer.AddTypeSourceInfo(TL.getUnderlyingTInfo(), Record);
555 }
556 void TypeLocWriter::VisitAutoTypeLoc(AutoTypeLoc TL) {
557   Writer.AddSourceLocation(TL.getNameLoc(), Record);
558 }
559 void TypeLocWriter::VisitRecordTypeLoc(RecordTypeLoc TL) {
560   Writer.AddSourceLocation(TL.getNameLoc(), Record);
561 }
562 void TypeLocWriter::VisitEnumTypeLoc(EnumTypeLoc TL) {
563   Writer.AddSourceLocation(TL.getNameLoc(), Record);
564 }
565 void TypeLocWriter::VisitAttributedTypeLoc(AttributedTypeLoc TL) {
566   Writer.AddSourceLocation(TL.getAttrNameLoc(), Record);
567   if (TL.hasAttrOperand()) {
568     SourceRange range = TL.getAttrOperandParensRange();
569     Writer.AddSourceLocation(range.getBegin(), Record);
570     Writer.AddSourceLocation(range.getEnd(), Record);
571   }
572   if (TL.hasAttrExprOperand()) {
573     Expr *operand = TL.getAttrExprOperand();
574     Record.push_back(operand ? 1 : 0);
575     if (operand) Writer.AddStmt(operand);
576   } else if (TL.hasAttrEnumOperand()) {
577     Writer.AddSourceLocation(TL.getAttrEnumOperandLoc(), Record);
578   }
579 }
580 void TypeLocWriter::VisitTemplateTypeParmTypeLoc(TemplateTypeParmTypeLoc TL) {
581   Writer.AddSourceLocation(TL.getNameLoc(), Record);
582 }
583 void TypeLocWriter::VisitSubstTemplateTypeParmTypeLoc(
584                                             SubstTemplateTypeParmTypeLoc TL) {
585   Writer.AddSourceLocation(TL.getNameLoc(), Record);
586 }
587 void TypeLocWriter::VisitSubstTemplateTypeParmPackTypeLoc(
588                                           SubstTemplateTypeParmPackTypeLoc TL) {
589   Writer.AddSourceLocation(TL.getNameLoc(), Record);
590 }
591 void TypeLocWriter::VisitTemplateSpecializationTypeLoc(
592                                            TemplateSpecializationTypeLoc TL) {
593   Writer.AddSourceLocation(TL.getTemplateKeywordLoc(), Record);
594   Writer.AddSourceLocation(TL.getTemplateNameLoc(), Record);
595   Writer.AddSourceLocation(TL.getLAngleLoc(), Record);
596   Writer.AddSourceLocation(TL.getRAngleLoc(), Record);
597   for (unsigned i = 0, e = TL.getNumArgs(); i != e; ++i)
598     Writer.AddTemplateArgumentLocInfo(TL.getArgLoc(i).getArgument().getKind(),
599                                       TL.getArgLoc(i).getLocInfo(), Record);
600 }
601 void TypeLocWriter::VisitParenTypeLoc(ParenTypeLoc TL) {
602   Writer.AddSourceLocation(TL.getLParenLoc(), Record);
603   Writer.AddSourceLocation(TL.getRParenLoc(), Record);
604 }
605 void TypeLocWriter::VisitElaboratedTypeLoc(ElaboratedTypeLoc TL) {
606   Writer.AddSourceLocation(TL.getElaboratedKeywordLoc(), Record);
607   Writer.AddNestedNameSpecifierLoc(TL.getQualifierLoc(), Record);
608 }
609 void TypeLocWriter::VisitInjectedClassNameTypeLoc(InjectedClassNameTypeLoc TL) {
610   Writer.AddSourceLocation(TL.getNameLoc(), Record);
611 }
612 void TypeLocWriter::VisitDependentNameTypeLoc(DependentNameTypeLoc TL) {
613   Writer.AddSourceLocation(TL.getElaboratedKeywordLoc(), Record);
614   Writer.AddNestedNameSpecifierLoc(TL.getQualifierLoc(), Record);
615   Writer.AddSourceLocation(TL.getNameLoc(), Record);
616 }
617 void TypeLocWriter::VisitDependentTemplateSpecializationTypeLoc(
618        DependentTemplateSpecializationTypeLoc TL) {
619   Writer.AddSourceLocation(TL.getElaboratedKeywordLoc(), Record);
620   Writer.AddNestedNameSpecifierLoc(TL.getQualifierLoc(), Record);
621   Writer.AddSourceLocation(TL.getTemplateKeywordLoc(), Record);
622   Writer.AddSourceLocation(TL.getTemplateNameLoc(), Record);
623   Writer.AddSourceLocation(TL.getLAngleLoc(), Record);
624   Writer.AddSourceLocation(TL.getRAngleLoc(), Record);
625   for (unsigned I = 0, E = TL.getNumArgs(); I != E; ++I)
626     Writer.AddTemplateArgumentLocInfo(TL.getArgLoc(I).getArgument().getKind(),
627                                       TL.getArgLoc(I).getLocInfo(), Record);
628 }
629 void TypeLocWriter::VisitPackExpansionTypeLoc(PackExpansionTypeLoc TL) {
630   Writer.AddSourceLocation(TL.getEllipsisLoc(), Record);
631 }
632 void TypeLocWriter::VisitObjCInterfaceTypeLoc(ObjCInterfaceTypeLoc TL) {
633   Writer.AddSourceLocation(TL.getNameLoc(), Record);
634 }
635 void TypeLocWriter::VisitObjCObjectTypeLoc(ObjCObjectTypeLoc TL) {
636   Record.push_back(TL.hasBaseTypeAsWritten());
637   Writer.AddSourceLocation(TL.getLAngleLoc(), Record);
638   Writer.AddSourceLocation(TL.getRAngleLoc(), Record);
639   for (unsigned i = 0, e = TL.getNumProtocols(); i != e; ++i)
640     Writer.AddSourceLocation(TL.getProtocolLoc(i), Record);
641 }
642 void TypeLocWriter::VisitObjCObjectPointerTypeLoc(ObjCObjectPointerTypeLoc TL) {
643   Writer.AddSourceLocation(TL.getStarLoc(), Record);
644 }
645 void TypeLocWriter::VisitAtomicTypeLoc(AtomicTypeLoc TL) {
646   Writer.AddSourceLocation(TL.getKWLoc(), Record);
647   Writer.AddSourceLocation(TL.getLParenLoc(), Record);
648   Writer.AddSourceLocation(TL.getRParenLoc(), Record);
649 }
650 
651 //===----------------------------------------------------------------------===//
652 // ASTWriter Implementation
653 //===----------------------------------------------------------------------===//
654 
655 static void EmitBlockID(unsigned ID, const char *Name,
656                         llvm::BitstreamWriter &Stream,
657                         ASTWriter::RecordDataImpl &Record) {
658   Record.clear();
659   Record.push_back(ID);
660   Stream.EmitRecord(llvm::bitc::BLOCKINFO_CODE_SETBID, Record);
661 
662   // Emit the block name if present.
663   if (Name == 0 || Name[0] == 0) return;
664   Record.clear();
665   while (*Name)
666     Record.push_back(*Name++);
667   Stream.EmitRecord(llvm::bitc::BLOCKINFO_CODE_BLOCKNAME, Record);
668 }
669 
670 static void EmitRecordID(unsigned ID, const char *Name,
671                          llvm::BitstreamWriter &Stream,
672                          ASTWriter::RecordDataImpl &Record) {
673   Record.clear();
674   Record.push_back(ID);
675   while (*Name)
676     Record.push_back(*Name++);
677   Stream.EmitRecord(llvm::bitc::BLOCKINFO_CODE_SETRECORDNAME, Record);
678 }
679 
680 static void AddStmtsExprs(llvm::BitstreamWriter &Stream,
681                           ASTWriter::RecordDataImpl &Record) {
682 #define RECORD(X) EmitRecordID(X, #X, Stream, Record)
683   RECORD(STMT_STOP);
684   RECORD(STMT_NULL_PTR);
685   RECORD(STMT_NULL);
686   RECORD(STMT_COMPOUND);
687   RECORD(STMT_CASE);
688   RECORD(STMT_DEFAULT);
689   RECORD(STMT_LABEL);
690   RECORD(STMT_ATTRIBUTED);
691   RECORD(STMT_IF);
692   RECORD(STMT_SWITCH);
693   RECORD(STMT_WHILE);
694   RECORD(STMT_DO);
695   RECORD(STMT_FOR);
696   RECORD(STMT_GOTO);
697   RECORD(STMT_INDIRECT_GOTO);
698   RECORD(STMT_CONTINUE);
699   RECORD(STMT_BREAK);
700   RECORD(STMT_RETURN);
701   RECORD(STMT_DECL);
702   RECORD(STMT_GCCASM);
703   RECORD(STMT_MSASM);
704   RECORD(EXPR_PREDEFINED);
705   RECORD(EXPR_DECL_REF);
706   RECORD(EXPR_INTEGER_LITERAL);
707   RECORD(EXPR_FLOATING_LITERAL);
708   RECORD(EXPR_IMAGINARY_LITERAL);
709   RECORD(EXPR_STRING_LITERAL);
710   RECORD(EXPR_CHARACTER_LITERAL);
711   RECORD(EXPR_PAREN);
712   RECORD(EXPR_UNARY_OPERATOR);
713   RECORD(EXPR_SIZEOF_ALIGN_OF);
714   RECORD(EXPR_ARRAY_SUBSCRIPT);
715   RECORD(EXPR_CALL);
716   RECORD(EXPR_MEMBER);
717   RECORD(EXPR_BINARY_OPERATOR);
718   RECORD(EXPR_COMPOUND_ASSIGN_OPERATOR);
719   RECORD(EXPR_CONDITIONAL_OPERATOR);
720   RECORD(EXPR_IMPLICIT_CAST);
721   RECORD(EXPR_CSTYLE_CAST);
722   RECORD(EXPR_COMPOUND_LITERAL);
723   RECORD(EXPR_EXT_VECTOR_ELEMENT);
724   RECORD(EXPR_INIT_LIST);
725   RECORD(EXPR_DESIGNATED_INIT);
726   RECORD(EXPR_IMPLICIT_VALUE_INIT);
727   RECORD(EXPR_VA_ARG);
728   RECORD(EXPR_ADDR_LABEL);
729   RECORD(EXPR_STMT);
730   RECORD(EXPR_CHOOSE);
731   RECORD(EXPR_GNU_NULL);
732   RECORD(EXPR_SHUFFLE_VECTOR);
733   RECORD(EXPR_BLOCK);
734   RECORD(EXPR_GENERIC_SELECTION);
735   RECORD(EXPR_OBJC_STRING_LITERAL);
736   RECORD(EXPR_OBJC_BOXED_EXPRESSION);
737   RECORD(EXPR_OBJC_ARRAY_LITERAL);
738   RECORD(EXPR_OBJC_DICTIONARY_LITERAL);
739   RECORD(EXPR_OBJC_ENCODE);
740   RECORD(EXPR_OBJC_SELECTOR_EXPR);
741   RECORD(EXPR_OBJC_PROTOCOL_EXPR);
742   RECORD(EXPR_OBJC_IVAR_REF_EXPR);
743   RECORD(EXPR_OBJC_PROPERTY_REF_EXPR);
744   RECORD(EXPR_OBJC_KVC_REF_EXPR);
745   RECORD(EXPR_OBJC_MESSAGE_EXPR);
746   RECORD(STMT_OBJC_FOR_COLLECTION);
747   RECORD(STMT_OBJC_CATCH);
748   RECORD(STMT_OBJC_FINALLY);
749   RECORD(STMT_OBJC_AT_TRY);
750   RECORD(STMT_OBJC_AT_SYNCHRONIZED);
751   RECORD(STMT_OBJC_AT_THROW);
752   RECORD(EXPR_OBJC_BOOL_LITERAL);
753   RECORD(EXPR_CXX_OPERATOR_CALL);
754   RECORD(EXPR_CXX_CONSTRUCT);
755   RECORD(EXPR_CXX_STATIC_CAST);
756   RECORD(EXPR_CXX_DYNAMIC_CAST);
757   RECORD(EXPR_CXX_REINTERPRET_CAST);
758   RECORD(EXPR_CXX_CONST_CAST);
759   RECORD(EXPR_CXX_FUNCTIONAL_CAST);
760   RECORD(EXPR_USER_DEFINED_LITERAL);
761   RECORD(EXPR_CXX_STD_INITIALIZER_LIST);
762   RECORD(EXPR_CXX_BOOL_LITERAL);
763   RECORD(EXPR_CXX_NULL_PTR_LITERAL);
764   RECORD(EXPR_CXX_TYPEID_EXPR);
765   RECORD(EXPR_CXX_TYPEID_TYPE);
766   RECORD(EXPR_CXX_UUIDOF_EXPR);
767   RECORD(EXPR_CXX_UUIDOF_TYPE);
768   RECORD(EXPR_CXX_THIS);
769   RECORD(EXPR_CXX_THROW);
770   RECORD(EXPR_CXX_DEFAULT_ARG);
771   RECORD(EXPR_CXX_BIND_TEMPORARY);
772   RECORD(EXPR_CXX_SCALAR_VALUE_INIT);
773   RECORD(EXPR_CXX_NEW);
774   RECORD(EXPR_CXX_DELETE);
775   RECORD(EXPR_CXX_PSEUDO_DESTRUCTOR);
776   RECORD(EXPR_EXPR_WITH_CLEANUPS);
777   RECORD(EXPR_CXX_DEPENDENT_SCOPE_MEMBER);
778   RECORD(EXPR_CXX_DEPENDENT_SCOPE_DECL_REF);
779   RECORD(EXPR_CXX_UNRESOLVED_CONSTRUCT);
780   RECORD(EXPR_CXX_UNRESOLVED_MEMBER);
781   RECORD(EXPR_CXX_UNRESOLVED_LOOKUP);
782   RECORD(EXPR_CXX_NOEXCEPT);
783   RECORD(EXPR_OPAQUE_VALUE);
784   RECORD(EXPR_PACK_EXPANSION);
785   RECORD(EXPR_SIZEOF_PACK);
786   RECORD(EXPR_SUBST_NON_TYPE_TEMPLATE_PARM_PACK);
787   RECORD(EXPR_CUDA_KERNEL_CALL);
788 #undef RECORD
789 }
790 
791 void ASTWriter::WriteBlockInfoBlock() {
792   RecordData Record;
793   Stream.EnterSubblock(llvm::bitc::BLOCKINFO_BLOCK_ID, 3);
794 
795 #define BLOCK(X) EmitBlockID(X ## _ID, #X, Stream, Record)
796 #define RECORD(X) EmitRecordID(X, #X, Stream, Record)
797 
798   // Control Block.
799   BLOCK(CONTROL_BLOCK);
800   RECORD(METADATA);
801   RECORD(MODULE_NAME);
802   RECORD(MODULE_MAP_FILE);
803   RECORD(IMPORTS);
804   RECORD(LANGUAGE_OPTIONS);
805   RECORD(TARGET_OPTIONS);
806   RECORD(ORIGINAL_FILE);
807   RECORD(ORIGINAL_PCH_DIR);
808   RECORD(ORIGINAL_FILE_ID);
809   RECORD(INPUT_FILE_OFFSETS);
810   RECORD(DIAGNOSTIC_OPTIONS);
811   RECORD(FILE_SYSTEM_OPTIONS);
812   RECORD(HEADER_SEARCH_OPTIONS);
813   RECORD(PREPROCESSOR_OPTIONS);
814 
815   BLOCK(INPUT_FILES_BLOCK);
816   RECORD(INPUT_FILE);
817 
818   // AST Top-Level Block.
819   BLOCK(AST_BLOCK);
820   RECORD(TYPE_OFFSET);
821   RECORD(DECL_OFFSET);
822   RECORD(IDENTIFIER_OFFSET);
823   RECORD(IDENTIFIER_TABLE);
824   RECORD(EAGERLY_DESERIALIZED_DECLS);
825   RECORD(SPECIAL_TYPES);
826   RECORD(STATISTICS);
827   RECORD(TENTATIVE_DEFINITIONS);
828   RECORD(UNUSED_FILESCOPED_DECLS);
829   RECORD(LOCALLY_SCOPED_EXTERN_C_DECLS);
830   RECORD(SELECTOR_OFFSETS);
831   RECORD(METHOD_POOL);
832   RECORD(PP_COUNTER_VALUE);
833   RECORD(SOURCE_LOCATION_OFFSETS);
834   RECORD(SOURCE_LOCATION_PRELOADS);
835   RECORD(EXT_VECTOR_DECLS);
836   RECORD(PPD_ENTITIES_OFFSETS);
837   RECORD(REFERENCED_SELECTOR_POOL);
838   RECORD(TU_UPDATE_LEXICAL);
839   RECORD(LOCAL_REDECLARATIONS_MAP);
840   RECORD(SEMA_DECL_REFS);
841   RECORD(WEAK_UNDECLARED_IDENTIFIERS);
842   RECORD(PENDING_IMPLICIT_INSTANTIATIONS);
843   RECORD(DECL_REPLACEMENTS);
844   RECORD(UPDATE_VISIBLE);
845   RECORD(DECL_UPDATE_OFFSETS);
846   RECORD(DECL_UPDATES);
847   RECORD(CXX_BASE_SPECIFIER_OFFSETS);
848   RECORD(DIAG_PRAGMA_MAPPINGS);
849   RECORD(CUDA_SPECIAL_DECL_REFS);
850   RECORD(HEADER_SEARCH_TABLE);
851   RECORD(FP_PRAGMA_OPTIONS);
852   RECORD(OPENCL_EXTENSIONS);
853   RECORD(DELEGATING_CTORS);
854   RECORD(KNOWN_NAMESPACES);
855   RECORD(UNDEFINED_BUT_USED);
856   RECORD(MODULE_OFFSET_MAP);
857   RECORD(SOURCE_MANAGER_LINE_TABLE);
858   RECORD(OBJC_CATEGORIES_MAP);
859   RECORD(FILE_SORTED_DECLS);
860   RECORD(IMPORTED_MODULES);
861   RECORD(MERGED_DECLARATIONS);
862   RECORD(LOCAL_REDECLARATIONS);
863   RECORD(OBJC_CATEGORIES);
864   RECORD(MACRO_OFFSET);
865   RECORD(MACRO_TABLE);
866   RECORD(LATE_PARSED_TEMPLATE);
867 
868   // SourceManager Block.
869   BLOCK(SOURCE_MANAGER_BLOCK);
870   RECORD(SM_SLOC_FILE_ENTRY);
871   RECORD(SM_SLOC_BUFFER_ENTRY);
872   RECORD(SM_SLOC_BUFFER_BLOB);
873   RECORD(SM_SLOC_EXPANSION_ENTRY);
874 
875   // Preprocessor Block.
876   BLOCK(PREPROCESSOR_BLOCK);
877   RECORD(PP_MACRO_OBJECT_LIKE);
878   RECORD(PP_MACRO_FUNCTION_LIKE);
879   RECORD(PP_TOKEN);
880 
881   // Decls and Types block.
882   BLOCK(DECLTYPES_BLOCK);
883   RECORD(TYPE_EXT_QUAL);
884   RECORD(TYPE_COMPLEX);
885   RECORD(TYPE_POINTER);
886   RECORD(TYPE_BLOCK_POINTER);
887   RECORD(TYPE_LVALUE_REFERENCE);
888   RECORD(TYPE_RVALUE_REFERENCE);
889   RECORD(TYPE_MEMBER_POINTER);
890   RECORD(TYPE_CONSTANT_ARRAY);
891   RECORD(TYPE_INCOMPLETE_ARRAY);
892   RECORD(TYPE_VARIABLE_ARRAY);
893   RECORD(TYPE_VECTOR);
894   RECORD(TYPE_EXT_VECTOR);
895   RECORD(TYPE_FUNCTION_PROTO);
896   RECORD(TYPE_FUNCTION_NO_PROTO);
897   RECORD(TYPE_TYPEDEF);
898   RECORD(TYPE_TYPEOF_EXPR);
899   RECORD(TYPE_TYPEOF);
900   RECORD(TYPE_RECORD);
901   RECORD(TYPE_ENUM);
902   RECORD(TYPE_OBJC_INTERFACE);
903   RECORD(TYPE_OBJC_OBJECT);
904   RECORD(TYPE_OBJC_OBJECT_POINTER);
905   RECORD(TYPE_DECLTYPE);
906   RECORD(TYPE_ELABORATED);
907   RECORD(TYPE_SUBST_TEMPLATE_TYPE_PARM);
908   RECORD(TYPE_UNRESOLVED_USING);
909   RECORD(TYPE_INJECTED_CLASS_NAME);
910   RECORD(TYPE_OBJC_OBJECT);
911   RECORD(TYPE_TEMPLATE_TYPE_PARM);
912   RECORD(TYPE_TEMPLATE_SPECIALIZATION);
913   RECORD(TYPE_DEPENDENT_NAME);
914   RECORD(TYPE_DEPENDENT_TEMPLATE_SPECIALIZATION);
915   RECORD(TYPE_DEPENDENT_SIZED_ARRAY);
916   RECORD(TYPE_PAREN);
917   RECORD(TYPE_PACK_EXPANSION);
918   RECORD(TYPE_ATTRIBUTED);
919   RECORD(TYPE_SUBST_TEMPLATE_TYPE_PARM_PACK);
920   RECORD(TYPE_ATOMIC);
921   RECORD(DECL_TYPEDEF);
922   RECORD(DECL_ENUM);
923   RECORD(DECL_RECORD);
924   RECORD(DECL_ENUM_CONSTANT);
925   RECORD(DECL_FUNCTION);
926   RECORD(DECL_OBJC_METHOD);
927   RECORD(DECL_OBJC_INTERFACE);
928   RECORD(DECL_OBJC_PROTOCOL);
929   RECORD(DECL_OBJC_IVAR);
930   RECORD(DECL_OBJC_AT_DEFS_FIELD);
931   RECORD(DECL_OBJC_CATEGORY);
932   RECORD(DECL_OBJC_CATEGORY_IMPL);
933   RECORD(DECL_OBJC_IMPLEMENTATION);
934   RECORD(DECL_OBJC_COMPATIBLE_ALIAS);
935   RECORD(DECL_OBJC_PROPERTY);
936   RECORD(DECL_OBJC_PROPERTY_IMPL);
937   RECORD(DECL_FIELD);
938   RECORD(DECL_MS_PROPERTY);
939   RECORD(DECL_VAR);
940   RECORD(DECL_IMPLICIT_PARAM);
941   RECORD(DECL_PARM_VAR);
942   RECORD(DECL_FILE_SCOPE_ASM);
943   RECORD(DECL_BLOCK);
944   RECORD(DECL_CONTEXT_LEXICAL);
945   RECORD(DECL_CONTEXT_VISIBLE);
946   RECORD(DECL_NAMESPACE);
947   RECORD(DECL_NAMESPACE_ALIAS);
948   RECORD(DECL_USING);
949   RECORD(DECL_USING_SHADOW);
950   RECORD(DECL_USING_DIRECTIVE);
951   RECORD(DECL_UNRESOLVED_USING_VALUE);
952   RECORD(DECL_UNRESOLVED_USING_TYPENAME);
953   RECORD(DECL_LINKAGE_SPEC);
954   RECORD(DECL_CXX_RECORD);
955   RECORD(DECL_CXX_METHOD);
956   RECORD(DECL_CXX_CONSTRUCTOR);
957   RECORD(DECL_CXX_DESTRUCTOR);
958   RECORD(DECL_CXX_CONVERSION);
959   RECORD(DECL_ACCESS_SPEC);
960   RECORD(DECL_FRIEND);
961   RECORD(DECL_FRIEND_TEMPLATE);
962   RECORD(DECL_CLASS_TEMPLATE);
963   RECORD(DECL_CLASS_TEMPLATE_SPECIALIZATION);
964   RECORD(DECL_CLASS_TEMPLATE_PARTIAL_SPECIALIZATION);
965   RECORD(DECL_VAR_TEMPLATE);
966   RECORD(DECL_VAR_TEMPLATE_SPECIALIZATION);
967   RECORD(DECL_VAR_TEMPLATE_PARTIAL_SPECIALIZATION);
968   RECORD(DECL_FUNCTION_TEMPLATE);
969   RECORD(DECL_TEMPLATE_TYPE_PARM);
970   RECORD(DECL_NON_TYPE_TEMPLATE_PARM);
971   RECORD(DECL_TEMPLATE_TEMPLATE_PARM);
972   RECORD(DECL_STATIC_ASSERT);
973   RECORD(DECL_CXX_BASE_SPECIFIERS);
974   RECORD(DECL_INDIRECTFIELD);
975   RECORD(DECL_EXPANDED_NON_TYPE_TEMPLATE_PARM_PACK);
976 
977   // Statements and Exprs can occur in the Decls and Types block.
978   AddStmtsExprs(Stream, Record);
979 
980   BLOCK(PREPROCESSOR_DETAIL_BLOCK);
981   RECORD(PPD_MACRO_EXPANSION);
982   RECORD(PPD_MACRO_DEFINITION);
983   RECORD(PPD_INCLUSION_DIRECTIVE);
984 
985 #undef RECORD
986 #undef BLOCK
987   Stream.ExitBlock();
988 }
989 
990 /// \brief Adjusts the given filename to only write out the portion of the
991 /// filename that is not part of the system root directory.
992 ///
993 /// \param Filename the file name to adjust.
994 ///
995 /// \param isysroot When non-NULL, the PCH file is a relocatable PCH file and
996 /// the returned filename will be adjusted by this system root.
997 ///
998 /// \returns either the original filename (if it needs no adjustment) or the
999 /// adjusted filename (which points into the @p Filename parameter).
1000 static const char *
1001 adjustFilenameForRelocatablePCH(const char *Filename, StringRef isysroot) {
1002   assert(Filename && "No file name to adjust?");
1003 
1004   if (isysroot.empty())
1005     return Filename;
1006 
1007   // Verify that the filename and the system root have the same prefix.
1008   unsigned Pos = 0;
1009   for (; Filename[Pos] && Pos < isysroot.size(); ++Pos)
1010     if (Filename[Pos] != isysroot[Pos])
1011       return Filename; // Prefixes don't match.
1012 
1013   // We hit the end of the filename before we hit the end of the system root.
1014   if (!Filename[Pos])
1015     return Filename;
1016 
1017   // If the file name has a '/' at the current position, skip over the '/'.
1018   // We distinguish sysroot-based includes from absolute includes by the
1019   // absence of '/' at the beginning of sysroot-based includes.
1020   if (Filename[Pos] == '/')
1021     ++Pos;
1022 
1023   return Filename + Pos;
1024 }
1025 
1026 /// \brief Write the control block.
1027 void ASTWriter::WriteControlBlock(Preprocessor &PP, ASTContext &Context,
1028                                   StringRef isysroot,
1029                                   const std::string &OutputFile) {
1030   using namespace llvm;
1031   Stream.EnterSubblock(CONTROL_BLOCK_ID, 5);
1032   RecordData Record;
1033 
1034   // Metadata
1035   BitCodeAbbrev *MetadataAbbrev = new BitCodeAbbrev();
1036   MetadataAbbrev->Add(BitCodeAbbrevOp(METADATA));
1037   MetadataAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 16)); // Major
1038   MetadataAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 16)); // Minor
1039   MetadataAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 16)); // Clang maj.
1040   MetadataAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 16)); // Clang min.
1041   MetadataAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Relocatable
1042   MetadataAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Errors
1043   MetadataAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // SVN branch/tag
1044   unsigned MetadataAbbrevCode = Stream.EmitAbbrev(MetadataAbbrev);
1045   Record.push_back(METADATA);
1046   Record.push_back(VERSION_MAJOR);
1047   Record.push_back(VERSION_MINOR);
1048   Record.push_back(CLANG_VERSION_MAJOR);
1049   Record.push_back(CLANG_VERSION_MINOR);
1050   Record.push_back(!isysroot.empty());
1051   Record.push_back(ASTHasCompilerErrors);
1052   Stream.EmitRecordWithBlob(MetadataAbbrevCode, Record,
1053                             getClangFullRepositoryVersion());
1054 
1055   // Module name
1056   if (WritingModule) {
1057     BitCodeAbbrev *Abbrev = new BitCodeAbbrev();
1058     Abbrev->Add(BitCodeAbbrevOp(MODULE_NAME));
1059     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Name
1060     unsigned AbbrevCode = Stream.EmitAbbrev(Abbrev);
1061     RecordData Record;
1062     Record.push_back(MODULE_NAME);
1063     Stream.EmitRecordWithBlob(AbbrevCode, Record, WritingModule->Name);
1064   }
1065 
1066   // Module map file
1067   if (WritingModule) {
1068     BitCodeAbbrev *Abbrev = new BitCodeAbbrev();
1069     Abbrev->Add(BitCodeAbbrevOp(MODULE_MAP_FILE));
1070     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Filename
1071     unsigned AbbrevCode = Stream.EmitAbbrev(Abbrev);
1072 
1073     assert(WritingModule->ModuleMap && "missing module map");
1074     SmallString<128> ModuleMap(WritingModule->ModuleMap->getName());
1075     llvm::sys::fs::make_absolute(ModuleMap);
1076     RecordData Record;
1077     Record.push_back(MODULE_MAP_FILE);
1078     Stream.EmitRecordWithBlob(AbbrevCode, Record, ModuleMap.str());
1079   }
1080 
1081   // Imports
1082   if (Chain) {
1083     serialization::ModuleManager &Mgr = Chain->getModuleManager();
1084     Record.clear();
1085 
1086     for (ModuleManager::ModuleIterator M = Mgr.begin(), MEnd = Mgr.end();
1087          M != MEnd; ++M) {
1088       // Skip modules that weren't directly imported.
1089       if (!(*M)->isDirectlyImported())
1090         continue;
1091 
1092       Record.push_back((unsigned)(*M)->Kind); // FIXME: Stable encoding
1093       AddSourceLocation((*M)->ImportLoc, Record);
1094       Record.push_back((*M)->File->getSize());
1095       Record.push_back((*M)->File->getModificationTime());
1096       const std::string &FileName = (*M)->FileName;
1097       Record.push_back(FileName.size());
1098       Record.append(FileName.begin(), FileName.end());
1099     }
1100     Stream.EmitRecord(IMPORTS, Record);
1101   }
1102 
1103   // Language options.
1104   Record.clear();
1105   const LangOptions &LangOpts = Context.getLangOpts();
1106 #define LANGOPT(Name, Bits, Default, Description) \
1107   Record.push_back(LangOpts.Name);
1108 #define ENUM_LANGOPT(Name, Type, Bits, Default, Description) \
1109   Record.push_back(static_cast<unsigned>(LangOpts.get##Name()));
1110 #include "clang/Basic/LangOptions.def"
1111 #define SANITIZER(NAME, ID) Record.push_back(LangOpts.Sanitize.ID);
1112 #include "clang/Basic/Sanitizers.def"
1113 
1114   Record.push_back((unsigned) LangOpts.ObjCRuntime.getKind());
1115   AddVersionTuple(LangOpts.ObjCRuntime.getVersion(), Record);
1116 
1117   Record.push_back(LangOpts.CurrentModule.size());
1118   Record.append(LangOpts.CurrentModule.begin(), LangOpts.CurrentModule.end());
1119 
1120   // Comment options.
1121   Record.push_back(LangOpts.CommentOpts.BlockCommandNames.size());
1122   for (CommentOptions::BlockCommandNamesTy::const_iterator
1123            I = LangOpts.CommentOpts.BlockCommandNames.begin(),
1124            IEnd = LangOpts.CommentOpts.BlockCommandNames.end();
1125        I != IEnd; ++I) {
1126     AddString(*I, Record);
1127   }
1128   Record.push_back(LangOpts.CommentOpts.ParseAllComments);
1129 
1130   Stream.EmitRecord(LANGUAGE_OPTIONS, Record);
1131 
1132   // Target options.
1133   Record.clear();
1134   const TargetInfo &Target = Context.getTargetInfo();
1135   const TargetOptions &TargetOpts = Target.getTargetOpts();
1136   AddString(TargetOpts.Triple, Record);
1137   AddString(TargetOpts.CPU, Record);
1138   AddString(TargetOpts.ABI, Record);
1139   Record.push_back(TargetOpts.FeaturesAsWritten.size());
1140   for (unsigned I = 0, N = TargetOpts.FeaturesAsWritten.size(); I != N; ++I) {
1141     AddString(TargetOpts.FeaturesAsWritten[I], Record);
1142   }
1143   Record.push_back(TargetOpts.Features.size());
1144   for (unsigned I = 0, N = TargetOpts.Features.size(); I != N; ++I) {
1145     AddString(TargetOpts.Features[I], Record);
1146   }
1147   Stream.EmitRecord(TARGET_OPTIONS, Record);
1148 
1149   // Diagnostic options.
1150   Record.clear();
1151   const DiagnosticOptions &DiagOpts
1152     = Context.getDiagnostics().getDiagnosticOptions();
1153 #define DIAGOPT(Name, Bits, Default) Record.push_back(DiagOpts.Name);
1154 #define ENUM_DIAGOPT(Name, Type, Bits, Default) \
1155   Record.push_back(static_cast<unsigned>(DiagOpts.get##Name()));
1156 #include "clang/Basic/DiagnosticOptions.def"
1157   Record.push_back(DiagOpts.Warnings.size());
1158   for (unsigned I = 0, N = DiagOpts.Warnings.size(); I != N; ++I)
1159     AddString(DiagOpts.Warnings[I], Record);
1160   // Note: we don't serialize the log or serialization file names, because they
1161   // are generally transient files and will almost always be overridden.
1162   Stream.EmitRecord(DIAGNOSTIC_OPTIONS, Record);
1163 
1164   // File system options.
1165   Record.clear();
1166   const FileSystemOptions &FSOpts
1167     = Context.getSourceManager().getFileManager().getFileSystemOptions();
1168   AddString(FSOpts.WorkingDir, Record);
1169   Stream.EmitRecord(FILE_SYSTEM_OPTIONS, Record);
1170 
1171   // Header search options.
1172   Record.clear();
1173   const HeaderSearchOptions &HSOpts
1174     = PP.getHeaderSearchInfo().getHeaderSearchOpts();
1175   AddString(HSOpts.Sysroot, Record);
1176 
1177   // Include entries.
1178   Record.push_back(HSOpts.UserEntries.size());
1179   for (unsigned I = 0, N = HSOpts.UserEntries.size(); I != N; ++I) {
1180     const HeaderSearchOptions::Entry &Entry = HSOpts.UserEntries[I];
1181     AddString(Entry.Path, Record);
1182     Record.push_back(static_cast<unsigned>(Entry.Group));
1183     Record.push_back(Entry.IsFramework);
1184     Record.push_back(Entry.IgnoreSysRoot);
1185   }
1186 
1187   // System header prefixes.
1188   Record.push_back(HSOpts.SystemHeaderPrefixes.size());
1189   for (unsigned I = 0, N = HSOpts.SystemHeaderPrefixes.size(); I != N; ++I) {
1190     AddString(HSOpts.SystemHeaderPrefixes[I].Prefix, Record);
1191     Record.push_back(HSOpts.SystemHeaderPrefixes[I].IsSystemHeader);
1192   }
1193 
1194   AddString(HSOpts.ResourceDir, Record);
1195   AddString(HSOpts.ModuleCachePath, Record);
1196   AddString(HSOpts.ModuleUserBuildPath, Record);
1197   Record.push_back(HSOpts.DisableModuleHash);
1198   Record.push_back(HSOpts.UseBuiltinIncludes);
1199   Record.push_back(HSOpts.UseStandardSystemIncludes);
1200   Record.push_back(HSOpts.UseStandardCXXIncludes);
1201   Record.push_back(HSOpts.UseLibcxx);
1202   Stream.EmitRecord(HEADER_SEARCH_OPTIONS, Record);
1203 
1204   // Preprocessor options.
1205   Record.clear();
1206   const PreprocessorOptions &PPOpts = PP.getPreprocessorOpts();
1207 
1208   // Macro definitions.
1209   Record.push_back(PPOpts.Macros.size());
1210   for (unsigned I = 0, N = PPOpts.Macros.size(); I != N; ++I) {
1211     AddString(PPOpts.Macros[I].first, Record);
1212     Record.push_back(PPOpts.Macros[I].second);
1213   }
1214 
1215   // Includes
1216   Record.push_back(PPOpts.Includes.size());
1217   for (unsigned I = 0, N = PPOpts.Includes.size(); I != N; ++I)
1218     AddString(PPOpts.Includes[I], Record);
1219 
1220   // Macro includes
1221   Record.push_back(PPOpts.MacroIncludes.size());
1222   for (unsigned I = 0, N = PPOpts.MacroIncludes.size(); I != N; ++I)
1223     AddString(PPOpts.MacroIncludes[I], Record);
1224 
1225   Record.push_back(PPOpts.UsePredefines);
1226   // Detailed record is important since it is used for the module cache hash.
1227   Record.push_back(PPOpts.DetailedRecord);
1228   AddString(PPOpts.ImplicitPCHInclude, Record);
1229   AddString(PPOpts.ImplicitPTHInclude, Record);
1230   Record.push_back(static_cast<unsigned>(PPOpts.ObjCXXARCStandardLibrary));
1231   Stream.EmitRecord(PREPROCESSOR_OPTIONS, Record);
1232 
1233   // Original file name and file ID
1234   SourceManager &SM = Context.getSourceManager();
1235   if (const FileEntry *MainFile = SM.getFileEntryForID(SM.getMainFileID())) {
1236     BitCodeAbbrev *FileAbbrev = new BitCodeAbbrev();
1237     FileAbbrev->Add(BitCodeAbbrevOp(ORIGINAL_FILE));
1238     FileAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // File ID
1239     FileAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // File name
1240     unsigned FileAbbrevCode = Stream.EmitAbbrev(FileAbbrev);
1241 
1242     SmallString<128> MainFilePath(MainFile->getName());
1243 
1244     llvm::sys::fs::make_absolute(MainFilePath);
1245 
1246     const char *MainFileNameStr = MainFilePath.c_str();
1247     MainFileNameStr = adjustFilenameForRelocatablePCH(MainFileNameStr,
1248                                                       isysroot);
1249     Record.clear();
1250     Record.push_back(ORIGINAL_FILE);
1251     Record.push_back(SM.getMainFileID().getOpaqueValue());
1252     Stream.EmitRecordWithBlob(FileAbbrevCode, Record, MainFileNameStr);
1253   }
1254 
1255   Record.clear();
1256   Record.push_back(SM.getMainFileID().getOpaqueValue());
1257   Stream.EmitRecord(ORIGINAL_FILE_ID, Record);
1258 
1259   // Original PCH directory
1260   if (!OutputFile.empty() && OutputFile != "-") {
1261     BitCodeAbbrev *Abbrev = new BitCodeAbbrev();
1262     Abbrev->Add(BitCodeAbbrevOp(ORIGINAL_PCH_DIR));
1263     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // File name
1264     unsigned AbbrevCode = Stream.EmitAbbrev(Abbrev);
1265 
1266     SmallString<128> OutputPath(OutputFile);
1267 
1268     llvm::sys::fs::make_absolute(OutputPath);
1269     StringRef origDir = llvm::sys::path::parent_path(OutputPath);
1270 
1271     RecordData Record;
1272     Record.push_back(ORIGINAL_PCH_DIR);
1273     Stream.EmitRecordWithBlob(AbbrevCode, Record, origDir);
1274   }
1275 
1276   WriteInputFiles(Context.SourceMgr,
1277                   PP.getHeaderSearchInfo().getHeaderSearchOpts(),
1278                   isysroot,
1279                   PP.getLangOpts().Modules);
1280   Stream.ExitBlock();
1281 }
1282 
1283 namespace  {
1284   /// \brief An input file.
1285   struct InputFileEntry {
1286     const FileEntry *File;
1287     bool IsSystemFile;
1288     bool BufferOverridden;
1289   };
1290 }
1291 
1292 void ASTWriter::WriteInputFiles(SourceManager &SourceMgr,
1293                                 HeaderSearchOptions &HSOpts,
1294                                 StringRef isysroot,
1295                                 bool Modules) {
1296   using namespace llvm;
1297   Stream.EnterSubblock(INPUT_FILES_BLOCK_ID, 4);
1298   RecordData Record;
1299 
1300   // Create input-file abbreviation.
1301   BitCodeAbbrev *IFAbbrev = new BitCodeAbbrev();
1302   IFAbbrev->Add(BitCodeAbbrevOp(INPUT_FILE));
1303   IFAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // ID
1304   IFAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 12)); // Size
1305   IFAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 32)); // Modification time
1306   IFAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Overridden
1307   IFAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // File name
1308   unsigned IFAbbrevCode = Stream.EmitAbbrev(IFAbbrev);
1309 
1310   // Get all ContentCache objects for files, sorted by whether the file is a
1311   // system one or not. System files go at the back, users files at the front.
1312   std::deque<InputFileEntry> SortedFiles;
1313   for (unsigned I = 1, N = SourceMgr.local_sloc_entry_size(); I != N; ++I) {
1314     // Get this source location entry.
1315     const SrcMgr::SLocEntry *SLoc = &SourceMgr.getLocalSLocEntry(I);
1316     assert(&SourceMgr.getSLocEntry(FileID::get(I)) == SLoc);
1317 
1318     // We only care about file entries that were not overridden.
1319     if (!SLoc->isFile())
1320       continue;
1321     const SrcMgr::ContentCache *Cache = SLoc->getFile().getContentCache();
1322     if (!Cache->OrigEntry)
1323       continue;
1324 
1325     InputFileEntry Entry;
1326     Entry.File = Cache->OrigEntry;
1327     Entry.IsSystemFile = Cache->IsSystemFile;
1328     Entry.BufferOverridden = Cache->BufferOverridden;
1329     if (Cache->IsSystemFile)
1330       SortedFiles.push_back(Entry);
1331     else
1332       SortedFiles.push_front(Entry);
1333   }
1334 
1335   unsigned UserFilesNum = 0;
1336   // Write out all of the input files.
1337   std::vector<uint32_t> InputFileOffsets;
1338   for (std::deque<InputFileEntry>::iterator
1339          I = SortedFiles.begin(), E = SortedFiles.end(); I != E; ++I) {
1340     const InputFileEntry &Entry = *I;
1341 
1342     uint32_t &InputFileID = InputFileIDs[Entry.File];
1343     if (InputFileID != 0)
1344       continue; // already recorded this file.
1345 
1346     // Record this entry's offset.
1347     InputFileOffsets.push_back(Stream.GetCurrentBitNo());
1348 
1349     InputFileID = InputFileOffsets.size();
1350 
1351     if (!Entry.IsSystemFile)
1352       ++UserFilesNum;
1353 
1354     Record.clear();
1355     Record.push_back(INPUT_FILE);
1356     Record.push_back(InputFileOffsets.size());
1357 
1358     // Emit size/modification time for this file.
1359     Record.push_back(Entry.File->getSize());
1360     Record.push_back(Entry.File->getModificationTime());
1361 
1362     // Whether this file was overridden.
1363     Record.push_back(Entry.BufferOverridden);
1364 
1365     // Turn the file name into an absolute path, if it isn't already.
1366     const char *Filename = Entry.File->getName();
1367     SmallString<128> FilePath(Filename);
1368 
1369     // Ask the file manager to fixup the relative path for us. This will
1370     // honor the working directory.
1371     SourceMgr.getFileManager().FixupRelativePath(FilePath);
1372 
1373     // FIXME: This call to make_absolute shouldn't be necessary, the
1374     // call to FixupRelativePath should always return an absolute path.
1375     llvm::sys::fs::make_absolute(FilePath);
1376     Filename = FilePath.c_str();
1377 
1378     Filename = adjustFilenameForRelocatablePCH(Filename, isysroot);
1379 
1380     Stream.EmitRecordWithBlob(IFAbbrevCode, Record, Filename);
1381   }
1382 
1383   Stream.ExitBlock();
1384 
1385   // Create input file offsets abbreviation.
1386   BitCodeAbbrev *OffsetsAbbrev = new BitCodeAbbrev();
1387   OffsetsAbbrev->Add(BitCodeAbbrevOp(INPUT_FILE_OFFSETS));
1388   OffsetsAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // # input files
1389   OffsetsAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // # non-system
1390                                                                 //   input files
1391   OffsetsAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));   // Array
1392   unsigned OffsetsAbbrevCode = Stream.EmitAbbrev(OffsetsAbbrev);
1393 
1394   // Write input file offsets.
1395   Record.clear();
1396   Record.push_back(INPUT_FILE_OFFSETS);
1397   Record.push_back(InputFileOffsets.size());
1398   Record.push_back(UserFilesNum);
1399   Stream.EmitRecordWithBlob(OffsetsAbbrevCode, Record, data(InputFileOffsets));
1400 }
1401 
1402 //===----------------------------------------------------------------------===//
1403 // Source Manager Serialization
1404 //===----------------------------------------------------------------------===//
1405 
1406 /// \brief Create an abbreviation for the SLocEntry that refers to a
1407 /// file.
1408 static unsigned CreateSLocFileAbbrev(llvm::BitstreamWriter &Stream) {
1409   using namespace llvm;
1410   BitCodeAbbrev *Abbrev = new BitCodeAbbrev();
1411   Abbrev->Add(BitCodeAbbrevOp(SM_SLOC_FILE_ENTRY));
1412   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // Offset
1413   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // Include location
1414   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2)); // Characteristic
1415   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Line directives
1416   // FileEntry fields.
1417   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Input File ID
1418   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // NumCreatedFIDs
1419   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 24)); // FirstDeclIndex
1420   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // NumDecls
1421   return Stream.EmitAbbrev(Abbrev);
1422 }
1423 
1424 /// \brief Create an abbreviation for the SLocEntry that refers to a
1425 /// buffer.
1426 static unsigned CreateSLocBufferAbbrev(llvm::BitstreamWriter &Stream) {
1427   using namespace llvm;
1428   BitCodeAbbrev *Abbrev = new BitCodeAbbrev();
1429   Abbrev->Add(BitCodeAbbrevOp(SM_SLOC_BUFFER_ENTRY));
1430   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // Offset
1431   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // Include location
1432   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2)); // Characteristic
1433   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Line directives
1434   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Buffer name blob
1435   return Stream.EmitAbbrev(Abbrev);
1436 }
1437 
1438 /// \brief Create an abbreviation for the SLocEntry that refers to a
1439 /// buffer's blob.
1440 static unsigned CreateSLocBufferBlobAbbrev(llvm::BitstreamWriter &Stream) {
1441   using namespace llvm;
1442   BitCodeAbbrev *Abbrev = new BitCodeAbbrev();
1443   Abbrev->Add(BitCodeAbbrevOp(SM_SLOC_BUFFER_BLOB));
1444   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Blob
1445   return Stream.EmitAbbrev(Abbrev);
1446 }
1447 
1448 /// \brief Create an abbreviation for the SLocEntry that refers to a macro
1449 /// expansion.
1450 static unsigned CreateSLocExpansionAbbrev(llvm::BitstreamWriter &Stream) {
1451   using namespace llvm;
1452   BitCodeAbbrev *Abbrev = new BitCodeAbbrev();
1453   Abbrev->Add(BitCodeAbbrevOp(SM_SLOC_EXPANSION_ENTRY));
1454   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // Offset
1455   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // Spelling location
1456   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // Start location
1457   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // End location
1458   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Token length
1459   return Stream.EmitAbbrev(Abbrev);
1460 }
1461 
1462 namespace {
1463   // Trait used for the on-disk hash table of header search information.
1464   class HeaderFileInfoTrait {
1465     ASTWriter &Writer;
1466     const HeaderSearch &HS;
1467 
1468     // Keep track of the framework names we've used during serialization.
1469     SmallVector<char, 128> FrameworkStringData;
1470     llvm::StringMap<unsigned> FrameworkNameOffset;
1471 
1472   public:
1473     HeaderFileInfoTrait(ASTWriter &Writer, const HeaderSearch &HS)
1474       : Writer(Writer), HS(HS) { }
1475 
1476     struct key_type {
1477       const FileEntry *FE;
1478       const char *Filename;
1479     };
1480     typedef const key_type &key_type_ref;
1481 
1482     typedef HeaderFileInfo data_type;
1483     typedef const data_type &data_type_ref;
1484     typedef unsigned hash_value_type;
1485     typedef unsigned offset_type;
1486 
1487     static hash_value_type ComputeHash(key_type_ref key) {
1488       // The hash is based only on size/time of the file, so that the reader can
1489       // match even when symlinking or excess path elements ("foo/../", "../")
1490       // change the form of the name. However, complete path is still the key.
1491       return llvm::hash_combine(key.FE->getSize(),
1492                                 key.FE->getModificationTime());
1493     }
1494 
1495     std::pair<unsigned,unsigned>
1496     EmitKeyDataLength(raw_ostream& Out, key_type_ref key, data_type_ref Data) {
1497       using namespace llvm::support;
1498       endian::Writer<little> Writer(Out);
1499       unsigned KeyLen = strlen(key.Filename) + 1 + 8 + 8;
1500       Writer.write<uint16_t>(KeyLen);
1501       unsigned DataLen = 1 + 2 + 4 + 4;
1502       if (Data.isModuleHeader)
1503         DataLen += 4;
1504       Writer.write<uint8_t>(DataLen);
1505       return std::make_pair(KeyLen, DataLen);
1506     }
1507 
1508     void EmitKey(raw_ostream& Out, key_type_ref key, unsigned KeyLen) {
1509       using namespace llvm::support;
1510       endian::Writer<little> LE(Out);
1511       LE.write<uint64_t>(key.FE->getSize());
1512       KeyLen -= 8;
1513       LE.write<uint64_t>(key.FE->getModificationTime());
1514       KeyLen -= 8;
1515       Out.write(key.Filename, KeyLen);
1516     }
1517 
1518     void EmitData(raw_ostream &Out, key_type_ref key,
1519                   data_type_ref Data, unsigned DataLen) {
1520       using namespace llvm::support;
1521       endian::Writer<little> LE(Out);
1522       uint64_t Start = Out.tell(); (void)Start;
1523 
1524       unsigned char Flags = (Data.HeaderRole << 6)
1525                           | (Data.isImport << 5)
1526                           | (Data.isPragmaOnce << 4)
1527                           | (Data.DirInfo << 2)
1528                           | (Data.Resolved << 1)
1529                           | Data.IndexHeaderMapHeader;
1530       LE.write<uint8_t>(Flags);
1531       LE.write<uint16_t>(Data.NumIncludes);
1532 
1533       if (!Data.ControllingMacro)
1534         LE.write<uint32_t>(Data.ControllingMacroID);
1535       else
1536         LE.write<uint32_t>(Writer.getIdentifierRef(Data.ControllingMacro));
1537 
1538       unsigned Offset = 0;
1539       if (!Data.Framework.empty()) {
1540         // If this header refers into a framework, save the framework name.
1541         llvm::StringMap<unsigned>::iterator Pos
1542           = FrameworkNameOffset.find(Data.Framework);
1543         if (Pos == FrameworkNameOffset.end()) {
1544           Offset = FrameworkStringData.size() + 1;
1545           FrameworkStringData.append(Data.Framework.begin(),
1546                                      Data.Framework.end());
1547           FrameworkStringData.push_back(0);
1548 
1549           FrameworkNameOffset[Data.Framework] = Offset;
1550         } else
1551           Offset = Pos->second;
1552       }
1553       LE.write<uint32_t>(Offset);
1554 
1555       if (Data.isModuleHeader) {
1556         Module *Mod = HS.findModuleForHeader(key.FE).getModule();
1557         LE.write<uint32_t>(Writer.getExistingSubmoduleID(Mod));
1558       }
1559 
1560       assert(Out.tell() - Start == DataLen && "Wrong data length");
1561     }
1562 
1563     const char *strings_begin() const { return FrameworkStringData.begin(); }
1564     const char *strings_end() const { return FrameworkStringData.end(); }
1565   };
1566 } // end anonymous namespace
1567 
1568 /// \brief Write the header search block for the list of files that
1569 ///
1570 /// \param HS The header search structure to save.
1571 void ASTWriter::WriteHeaderSearch(const HeaderSearch &HS, StringRef isysroot) {
1572   SmallVector<const FileEntry *, 16> FilesByUID;
1573   HS.getFileMgr().GetUniqueIDMapping(FilesByUID);
1574 
1575   if (FilesByUID.size() > HS.header_file_size())
1576     FilesByUID.resize(HS.header_file_size());
1577 
1578   HeaderFileInfoTrait GeneratorTrait(*this, HS);
1579   llvm::OnDiskChainedHashTableGenerator<HeaderFileInfoTrait> Generator;
1580   SmallVector<const char *, 4> SavedStrings;
1581   unsigned NumHeaderSearchEntries = 0;
1582   for (unsigned UID = 0, LastUID = FilesByUID.size(); UID != LastUID; ++UID) {
1583     const FileEntry *File = FilesByUID[UID];
1584     if (!File)
1585       continue;
1586 
1587     // Use HeaderSearch's getFileInfo to make sure we get the HeaderFileInfo
1588     // from the external source if it was not provided already.
1589     HeaderFileInfo HFI;
1590     if (!HS.tryGetFileInfo(File, HFI) ||
1591         (HFI.External && Chain) ||
1592         (HFI.isModuleHeader && !HFI.isCompilingModuleHeader))
1593       continue;
1594 
1595     // Turn the file name into an absolute path, if it isn't already.
1596     const char *Filename = File->getName();
1597     Filename = adjustFilenameForRelocatablePCH(Filename, isysroot);
1598 
1599     // If we performed any translation on the file name at all, we need to
1600     // save this string, since the generator will refer to it later.
1601     if (Filename != File->getName()) {
1602       Filename = strdup(Filename);
1603       SavedStrings.push_back(Filename);
1604     }
1605 
1606     HeaderFileInfoTrait::key_type key = { File, Filename };
1607     Generator.insert(key, HFI, GeneratorTrait);
1608     ++NumHeaderSearchEntries;
1609   }
1610 
1611   // Create the on-disk hash table in a buffer.
1612   SmallString<4096> TableData;
1613   uint32_t BucketOffset;
1614   {
1615     using namespace llvm::support;
1616     llvm::raw_svector_ostream Out(TableData);
1617     // Make sure that no bucket is at offset 0
1618     endian::Writer<little>(Out).write<uint32_t>(0);
1619     BucketOffset = Generator.Emit(Out, GeneratorTrait);
1620   }
1621 
1622   // Create a blob abbreviation
1623   using namespace llvm;
1624   BitCodeAbbrev *Abbrev = new BitCodeAbbrev();
1625   Abbrev->Add(BitCodeAbbrevOp(HEADER_SEARCH_TABLE));
1626   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
1627   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
1628   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
1629   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
1630   unsigned TableAbbrev = Stream.EmitAbbrev(Abbrev);
1631 
1632   // Write the header search table
1633   RecordData Record;
1634   Record.push_back(HEADER_SEARCH_TABLE);
1635   Record.push_back(BucketOffset);
1636   Record.push_back(NumHeaderSearchEntries);
1637   Record.push_back(TableData.size());
1638   TableData.append(GeneratorTrait.strings_begin(),GeneratorTrait.strings_end());
1639   Stream.EmitRecordWithBlob(TableAbbrev, Record, TableData.str());
1640 
1641   // Free all of the strings we had to duplicate.
1642   for (unsigned I = 0, N = SavedStrings.size(); I != N; ++I)
1643     free(const_cast<char *>(SavedStrings[I]));
1644 }
1645 
1646 /// \brief Writes the block containing the serialized form of the
1647 /// source manager.
1648 ///
1649 /// TODO: We should probably use an on-disk hash table (stored in a
1650 /// blob), indexed based on the file name, so that we only create
1651 /// entries for files that we actually need. In the common case (no
1652 /// errors), we probably won't have to create file entries for any of
1653 /// the files in the AST.
1654 void ASTWriter::WriteSourceManagerBlock(SourceManager &SourceMgr,
1655                                         const Preprocessor &PP,
1656                                         StringRef isysroot) {
1657   RecordData Record;
1658 
1659   // Enter the source manager block.
1660   Stream.EnterSubblock(SOURCE_MANAGER_BLOCK_ID, 3);
1661 
1662   // Abbreviations for the various kinds of source-location entries.
1663   unsigned SLocFileAbbrv = CreateSLocFileAbbrev(Stream);
1664   unsigned SLocBufferAbbrv = CreateSLocBufferAbbrev(Stream);
1665   unsigned SLocBufferBlobAbbrv = CreateSLocBufferBlobAbbrev(Stream);
1666   unsigned SLocExpansionAbbrv = CreateSLocExpansionAbbrev(Stream);
1667 
1668   // Write out the source location entry table. We skip the first
1669   // entry, which is always the same dummy entry.
1670   std::vector<uint32_t> SLocEntryOffsets;
1671   RecordData PreloadSLocs;
1672   SLocEntryOffsets.reserve(SourceMgr.local_sloc_entry_size() - 1);
1673   for (unsigned I = 1, N = SourceMgr.local_sloc_entry_size();
1674        I != N; ++I) {
1675     // Get this source location entry.
1676     const SrcMgr::SLocEntry *SLoc = &SourceMgr.getLocalSLocEntry(I);
1677     FileID FID = FileID::get(I);
1678     assert(&SourceMgr.getSLocEntry(FID) == SLoc);
1679 
1680     // Record the offset of this source-location entry.
1681     SLocEntryOffsets.push_back(Stream.GetCurrentBitNo());
1682 
1683     // Figure out which record code to use.
1684     unsigned Code;
1685     if (SLoc->isFile()) {
1686       const SrcMgr::ContentCache *Cache = SLoc->getFile().getContentCache();
1687       if (Cache->OrigEntry) {
1688         Code = SM_SLOC_FILE_ENTRY;
1689       } else
1690         Code = SM_SLOC_BUFFER_ENTRY;
1691     } else
1692       Code = SM_SLOC_EXPANSION_ENTRY;
1693     Record.clear();
1694     Record.push_back(Code);
1695 
1696     // Starting offset of this entry within this module, so skip the dummy.
1697     Record.push_back(SLoc->getOffset() - 2);
1698     if (SLoc->isFile()) {
1699       const SrcMgr::FileInfo &File = SLoc->getFile();
1700       Record.push_back(File.getIncludeLoc().getRawEncoding());
1701       Record.push_back(File.getFileCharacteristic()); // FIXME: stable encoding
1702       Record.push_back(File.hasLineDirectives());
1703 
1704       const SrcMgr::ContentCache *Content = File.getContentCache();
1705       if (Content->OrigEntry) {
1706         assert(Content->OrigEntry == Content->ContentsEntry &&
1707                "Writing to AST an overridden file is not supported");
1708 
1709         // The source location entry is a file. Emit input file ID.
1710         assert(InputFileIDs[Content->OrigEntry] != 0 && "Missed file entry");
1711         Record.push_back(InputFileIDs[Content->OrigEntry]);
1712 
1713         Record.push_back(File.NumCreatedFIDs);
1714 
1715         FileDeclIDsTy::iterator FDI = FileDeclIDs.find(FID);
1716         if (FDI != FileDeclIDs.end()) {
1717           Record.push_back(FDI->second->FirstDeclIndex);
1718           Record.push_back(FDI->second->DeclIDs.size());
1719         } else {
1720           Record.push_back(0);
1721           Record.push_back(0);
1722         }
1723 
1724         Stream.EmitRecordWithAbbrev(SLocFileAbbrv, Record);
1725 
1726         if (Content->BufferOverridden) {
1727           Record.clear();
1728           Record.push_back(SM_SLOC_BUFFER_BLOB);
1729           const llvm::MemoryBuffer *Buffer
1730             = Content->getBuffer(PP.getDiagnostics(), PP.getSourceManager());
1731           Stream.EmitRecordWithBlob(SLocBufferBlobAbbrv, Record,
1732                                     StringRef(Buffer->getBufferStart(),
1733                                               Buffer->getBufferSize() + 1));
1734         }
1735       } else {
1736         // The source location entry is a buffer. The blob associated
1737         // with this entry contains the contents of the buffer.
1738 
1739         // We add one to the size so that we capture the trailing NULL
1740         // that is required by llvm::MemoryBuffer::getMemBuffer (on
1741         // the reader side).
1742         const llvm::MemoryBuffer *Buffer
1743           = Content->getBuffer(PP.getDiagnostics(), PP.getSourceManager());
1744         const char *Name = Buffer->getBufferIdentifier();
1745         Stream.EmitRecordWithBlob(SLocBufferAbbrv, Record,
1746                                   StringRef(Name, strlen(Name) + 1));
1747         Record.clear();
1748         Record.push_back(SM_SLOC_BUFFER_BLOB);
1749         Stream.EmitRecordWithBlob(SLocBufferBlobAbbrv, Record,
1750                                   StringRef(Buffer->getBufferStart(),
1751                                                   Buffer->getBufferSize() + 1));
1752 
1753         if (strcmp(Name, "<built-in>") == 0) {
1754           PreloadSLocs.push_back(SLocEntryOffsets.size());
1755         }
1756       }
1757     } else {
1758       // The source location entry is a macro expansion.
1759       const SrcMgr::ExpansionInfo &Expansion = SLoc->getExpansion();
1760       Record.push_back(Expansion.getSpellingLoc().getRawEncoding());
1761       Record.push_back(Expansion.getExpansionLocStart().getRawEncoding());
1762       Record.push_back(Expansion.isMacroArgExpansion() ? 0
1763                              : Expansion.getExpansionLocEnd().getRawEncoding());
1764 
1765       // Compute the token length for this macro expansion.
1766       unsigned NextOffset = SourceMgr.getNextLocalOffset();
1767       if (I + 1 != N)
1768         NextOffset = SourceMgr.getLocalSLocEntry(I + 1).getOffset();
1769       Record.push_back(NextOffset - SLoc->getOffset() - 1);
1770       Stream.EmitRecordWithAbbrev(SLocExpansionAbbrv, Record);
1771     }
1772   }
1773 
1774   Stream.ExitBlock();
1775 
1776   if (SLocEntryOffsets.empty())
1777     return;
1778 
1779   // Write the source-location offsets table into the AST block. This
1780   // table is used for lazily loading source-location information.
1781   using namespace llvm;
1782   BitCodeAbbrev *Abbrev = new BitCodeAbbrev();
1783   Abbrev->Add(BitCodeAbbrevOp(SOURCE_LOCATION_OFFSETS));
1784   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 16)); // # of slocs
1785   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 16)); // total size
1786   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // offsets
1787   unsigned SLocOffsetsAbbrev = Stream.EmitAbbrev(Abbrev);
1788 
1789   Record.clear();
1790   Record.push_back(SOURCE_LOCATION_OFFSETS);
1791   Record.push_back(SLocEntryOffsets.size());
1792   Record.push_back(SourceMgr.getNextLocalOffset() - 1); // skip dummy
1793   Stream.EmitRecordWithBlob(SLocOffsetsAbbrev, Record, data(SLocEntryOffsets));
1794 
1795   // Write the source location entry preloads array, telling the AST
1796   // reader which source locations entries it should load eagerly.
1797   Stream.EmitRecord(SOURCE_LOCATION_PRELOADS, PreloadSLocs);
1798 
1799   // Write the line table. It depends on remapping working, so it must come
1800   // after the source location offsets.
1801   if (SourceMgr.hasLineTable()) {
1802     LineTableInfo &LineTable = SourceMgr.getLineTable();
1803 
1804     Record.clear();
1805     // Emit the file names
1806     Record.push_back(LineTable.getNumFilenames());
1807     for (unsigned I = 0, N = LineTable.getNumFilenames(); I != N; ++I) {
1808       // Emit the file name
1809       const char *Filename = LineTable.getFilename(I);
1810       Filename = adjustFilenameForRelocatablePCH(Filename, isysroot);
1811       unsigned FilenameLen = Filename? strlen(Filename) : 0;
1812       Record.push_back(FilenameLen);
1813       if (FilenameLen)
1814         Record.insert(Record.end(), Filename, Filename + FilenameLen);
1815     }
1816 
1817     // Emit the line entries
1818     for (LineTableInfo::iterator L = LineTable.begin(), LEnd = LineTable.end();
1819          L != LEnd; ++L) {
1820       // Only emit entries for local files.
1821       if (L->first.ID < 0)
1822         continue;
1823 
1824       // Emit the file ID
1825       Record.push_back(L->first.ID);
1826 
1827       // Emit the line entries
1828       Record.push_back(L->second.size());
1829       for (std::vector<LineEntry>::iterator LE = L->second.begin(),
1830                                          LEEnd = L->second.end();
1831            LE != LEEnd; ++LE) {
1832         Record.push_back(LE->FileOffset);
1833         Record.push_back(LE->LineNo);
1834         Record.push_back(LE->FilenameID);
1835         Record.push_back((unsigned)LE->FileKind);
1836         Record.push_back(LE->IncludeOffset);
1837       }
1838     }
1839     Stream.EmitRecord(SOURCE_MANAGER_LINE_TABLE, Record);
1840   }
1841 }
1842 
1843 //===----------------------------------------------------------------------===//
1844 // Preprocessor Serialization
1845 //===----------------------------------------------------------------------===//
1846 
1847 namespace {
1848 class ASTMacroTableTrait {
1849 public:
1850   typedef IdentID key_type;
1851   typedef key_type key_type_ref;
1852 
1853   struct Data {
1854     uint32_t MacroDirectivesOffset;
1855   };
1856 
1857   typedef Data data_type;
1858   typedef const data_type &data_type_ref;
1859   typedef unsigned hash_value_type;
1860   typedef unsigned offset_type;
1861 
1862   static hash_value_type ComputeHash(IdentID IdID) {
1863     return llvm::hash_value(IdID);
1864   }
1865 
1866   std::pair<unsigned,unsigned>
1867   static EmitKeyDataLength(raw_ostream& Out,
1868                            key_type_ref Key, data_type_ref Data) {
1869     unsigned KeyLen = 4; // IdentID.
1870     unsigned DataLen = 4; // MacroDirectivesOffset.
1871     return std::make_pair(KeyLen, DataLen);
1872   }
1873 
1874   static void EmitKey(raw_ostream& Out, key_type_ref Key, unsigned KeyLen) {
1875     using namespace llvm::support;
1876     endian::Writer<little>(Out).write<uint32_t>(Key);
1877   }
1878 
1879   static void EmitData(raw_ostream& Out, key_type_ref Key, data_type_ref Data,
1880                        unsigned) {
1881     using namespace llvm::support;
1882     endian::Writer<little>(Out).write<uint32_t>(Data.MacroDirectivesOffset);
1883   }
1884 };
1885 } // end anonymous namespace
1886 
1887 static int compareMacroDirectives(
1888     const std::pair<const IdentifierInfo *, MacroDirective *> *X,
1889     const std::pair<const IdentifierInfo *, MacroDirective *> *Y) {
1890   return X->first->getName().compare(Y->first->getName());
1891 }
1892 
1893 static bool shouldIgnoreMacro(MacroDirective *MD, bool IsModule,
1894                               const Preprocessor &PP) {
1895   if (MacroInfo *MI = MD->getMacroInfo())
1896     if (MI->isBuiltinMacro())
1897       return true;
1898 
1899   if (IsModule) {
1900     SourceLocation Loc = MD->getLocation();
1901     if (Loc.isInvalid())
1902       return true;
1903     if (PP.getSourceManager().getFileID(Loc) == PP.getPredefinesFileID())
1904       return true;
1905   }
1906 
1907   return false;
1908 }
1909 
1910 /// \brief Writes the block containing the serialized form of the
1911 /// preprocessor.
1912 ///
1913 void ASTWriter::WritePreprocessor(const Preprocessor &PP, bool IsModule) {
1914   PreprocessingRecord *PPRec = PP.getPreprocessingRecord();
1915   if (PPRec)
1916     WritePreprocessorDetail(*PPRec);
1917 
1918   RecordData Record;
1919 
1920   // If the preprocessor __COUNTER__ value has been bumped, remember it.
1921   if (PP.getCounterValue() != 0) {
1922     Record.push_back(PP.getCounterValue());
1923     Stream.EmitRecord(PP_COUNTER_VALUE, Record);
1924     Record.clear();
1925   }
1926 
1927   // Enter the preprocessor block.
1928   Stream.EnterSubblock(PREPROCESSOR_BLOCK_ID, 3);
1929 
1930   // If the AST file contains __DATE__ or __TIME__ emit a warning about this.
1931   // FIXME: use diagnostics subsystem for localization etc.
1932   if (PP.SawDateOrTime())
1933     fprintf(stderr, "warning: precompiled header used __DATE__ or __TIME__.\n");
1934 
1935 
1936   // Loop over all the macro directives that are live at the end of the file,
1937   // emitting each to the PP section.
1938 
1939   // Construct the list of macro directives that need to be serialized.
1940   SmallVector<std::pair<const IdentifierInfo *, MacroDirective *>, 2>
1941     MacroDirectives;
1942   for (Preprocessor::macro_iterator
1943          I = PP.macro_begin(/*IncludeExternalMacros=*/false),
1944          E = PP.macro_end(/*IncludeExternalMacros=*/false);
1945        I != E; ++I) {
1946     MacroDirectives.push_back(std::make_pair(I->first, I->second));
1947   }
1948 
1949   // Sort the set of macro definitions that need to be serialized by the
1950   // name of the macro, to provide a stable ordering.
1951   llvm::array_pod_sort(MacroDirectives.begin(), MacroDirectives.end(),
1952                        &compareMacroDirectives);
1953 
1954   llvm::OnDiskChainedHashTableGenerator<ASTMacroTableTrait> Generator;
1955 
1956   // Emit the macro directives as a list and associate the offset with the
1957   // identifier they belong to.
1958   for (unsigned I = 0, N = MacroDirectives.size(); I != N; ++I) {
1959     const IdentifierInfo *Name = MacroDirectives[I].first;
1960     uint64_t MacroDirectiveOffset = Stream.GetCurrentBitNo();
1961     MacroDirective *MD = MacroDirectives[I].second;
1962 
1963     // If the macro or identifier need no updates, don't write the macro history
1964     // for this one.
1965     // FIXME: Chain the macro history instead of re-writing it.
1966     if (MD->isFromPCH() &&
1967         Name->isFromAST() && !Name->hasChangedSinceDeserialization())
1968       continue;
1969 
1970     // Emit the macro directives in reverse source order.
1971     for (; MD; MD = MD->getPrevious()) {
1972       if (shouldIgnoreMacro(MD, IsModule, PP))
1973         continue;
1974 
1975       AddSourceLocation(MD->getLocation(), Record);
1976       Record.push_back(MD->getKind());
1977       if (DefMacroDirective *DefMD = dyn_cast<DefMacroDirective>(MD)) {
1978         MacroID InfoID = getMacroRef(DefMD->getInfo(), Name);
1979         Record.push_back(InfoID);
1980         Record.push_back(DefMD->isImported());
1981         Record.push_back(DefMD->isAmbiguous());
1982 
1983       } else if (VisibilityMacroDirective *
1984                    VisMD = dyn_cast<VisibilityMacroDirective>(MD)) {
1985         Record.push_back(VisMD->isPublic());
1986       }
1987     }
1988     if (Record.empty())
1989       continue;
1990 
1991     Stream.EmitRecord(PP_MACRO_DIRECTIVE_HISTORY, Record);
1992     Record.clear();
1993 
1994     IdentMacroDirectivesOffsetMap[Name] = MacroDirectiveOffset;
1995 
1996     IdentID NameID = getIdentifierRef(Name);
1997     ASTMacroTableTrait::Data data;
1998     data.MacroDirectivesOffset = MacroDirectiveOffset;
1999     Generator.insert(NameID, data);
2000   }
2001 
2002   /// \brief Offsets of each of the macros into the bitstream, indexed by
2003   /// the local macro ID
2004   ///
2005   /// For each identifier that is associated with a macro, this map
2006   /// provides the offset into the bitstream where that macro is
2007   /// defined.
2008   std::vector<uint32_t> MacroOffsets;
2009 
2010   for (unsigned I = 0, N = MacroInfosToEmit.size(); I != N; ++I) {
2011     const IdentifierInfo *Name = MacroInfosToEmit[I].Name;
2012     MacroInfo *MI = MacroInfosToEmit[I].MI;
2013     MacroID ID = MacroInfosToEmit[I].ID;
2014 
2015     if (ID < FirstMacroID) {
2016       assert(0 && "Loaded MacroInfo entered MacroInfosToEmit ?");
2017       continue;
2018     }
2019 
2020     // Record the local offset of this macro.
2021     unsigned Index = ID - FirstMacroID;
2022     if (Index == MacroOffsets.size())
2023       MacroOffsets.push_back(Stream.GetCurrentBitNo());
2024     else {
2025       if (Index > MacroOffsets.size())
2026         MacroOffsets.resize(Index + 1);
2027 
2028       MacroOffsets[Index] = Stream.GetCurrentBitNo();
2029     }
2030 
2031     AddIdentifierRef(Name, Record);
2032     Record.push_back(inferSubmoduleIDFromLocation(MI->getDefinitionLoc()));
2033     AddSourceLocation(MI->getDefinitionLoc(), Record);
2034     AddSourceLocation(MI->getDefinitionEndLoc(), Record);
2035     Record.push_back(MI->isUsed());
2036     Record.push_back(MI->isUsedForHeaderGuard());
2037     unsigned Code;
2038     if (MI->isObjectLike()) {
2039       Code = PP_MACRO_OBJECT_LIKE;
2040     } else {
2041       Code = PP_MACRO_FUNCTION_LIKE;
2042 
2043       Record.push_back(MI->isC99Varargs());
2044       Record.push_back(MI->isGNUVarargs());
2045       Record.push_back(MI->hasCommaPasting());
2046       Record.push_back(MI->getNumArgs());
2047       for (MacroInfo::arg_iterator I = MI->arg_begin(), E = MI->arg_end();
2048            I != E; ++I)
2049         AddIdentifierRef(*I, Record);
2050     }
2051 
2052     // If we have a detailed preprocessing record, record the macro definition
2053     // ID that corresponds to this macro.
2054     if (PPRec)
2055       Record.push_back(MacroDefinitions[PPRec->findMacroDefinition(MI)]);
2056 
2057     Stream.EmitRecord(Code, Record);
2058     Record.clear();
2059 
2060     // Emit the tokens array.
2061     for (unsigned TokNo = 0, e = MI->getNumTokens(); TokNo != e; ++TokNo) {
2062       // Note that we know that the preprocessor does not have any annotation
2063       // tokens in it because they are created by the parser, and thus can't
2064       // be in a macro definition.
2065       const Token &Tok = MI->getReplacementToken(TokNo);
2066       AddToken(Tok, Record);
2067       Stream.EmitRecord(PP_TOKEN, Record);
2068       Record.clear();
2069     }
2070     ++NumMacros;
2071   }
2072 
2073   Stream.ExitBlock();
2074 
2075   // Create the on-disk hash table in a buffer.
2076   SmallString<4096> MacroTable;
2077   uint32_t BucketOffset;
2078   {
2079     using namespace llvm::support;
2080     llvm::raw_svector_ostream Out(MacroTable);
2081     // Make sure that no bucket is at offset 0
2082     endian::Writer<little>(Out).write<uint32_t>(0);
2083     BucketOffset = Generator.Emit(Out);
2084   }
2085 
2086   // Write the macro table
2087   using namespace llvm;
2088   BitCodeAbbrev *Abbrev = new BitCodeAbbrev();
2089   Abbrev->Add(BitCodeAbbrevOp(MACRO_TABLE));
2090   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
2091   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
2092   unsigned MacroTableAbbrev = Stream.EmitAbbrev(Abbrev);
2093 
2094   Record.push_back(MACRO_TABLE);
2095   Record.push_back(BucketOffset);
2096   Stream.EmitRecordWithBlob(MacroTableAbbrev, Record, MacroTable.str());
2097   Record.clear();
2098 
2099   // Write the offsets table for macro IDs.
2100   using namespace llvm;
2101   Abbrev = new BitCodeAbbrev();
2102   Abbrev->Add(BitCodeAbbrevOp(MACRO_OFFSET));
2103   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // # of macros
2104   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // first ID
2105   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
2106 
2107   unsigned MacroOffsetAbbrev = Stream.EmitAbbrev(Abbrev);
2108   Record.clear();
2109   Record.push_back(MACRO_OFFSET);
2110   Record.push_back(MacroOffsets.size());
2111   Record.push_back(FirstMacroID - NUM_PREDEF_MACRO_IDS);
2112   Stream.EmitRecordWithBlob(MacroOffsetAbbrev, Record,
2113                             data(MacroOffsets));
2114 }
2115 
2116 void ASTWriter::WritePreprocessorDetail(PreprocessingRecord &PPRec) {
2117   if (PPRec.local_begin() == PPRec.local_end())
2118     return;
2119 
2120   SmallVector<PPEntityOffset, 64> PreprocessedEntityOffsets;
2121 
2122   // Enter the preprocessor block.
2123   Stream.EnterSubblock(PREPROCESSOR_DETAIL_BLOCK_ID, 3);
2124 
2125   // If the preprocessor has a preprocessing record, emit it.
2126   unsigned NumPreprocessingRecords = 0;
2127   using namespace llvm;
2128 
2129   // Set up the abbreviation for
2130   unsigned InclusionAbbrev = 0;
2131   {
2132     BitCodeAbbrev *Abbrev = new BitCodeAbbrev();
2133     Abbrev->Add(BitCodeAbbrevOp(PPD_INCLUSION_DIRECTIVE));
2134     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // filename length
2135     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // in quotes
2136     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2)); // kind
2137     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // imported module
2138     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
2139     InclusionAbbrev = Stream.EmitAbbrev(Abbrev);
2140   }
2141 
2142   unsigned FirstPreprocessorEntityID
2143     = (Chain ? PPRec.getNumLoadedPreprocessedEntities() : 0)
2144     + NUM_PREDEF_PP_ENTITY_IDS;
2145   unsigned NextPreprocessorEntityID = FirstPreprocessorEntityID;
2146   RecordData Record;
2147   for (PreprocessingRecord::iterator E = PPRec.local_begin(),
2148                                   EEnd = PPRec.local_end();
2149        E != EEnd;
2150        (void)++E, ++NumPreprocessingRecords, ++NextPreprocessorEntityID) {
2151     Record.clear();
2152 
2153     PreprocessedEntityOffsets.push_back(PPEntityOffset((*E)->getSourceRange(),
2154                                                      Stream.GetCurrentBitNo()));
2155 
2156     if (MacroDefinition *MD = dyn_cast<MacroDefinition>(*E)) {
2157       // Record this macro definition's ID.
2158       MacroDefinitions[MD] = NextPreprocessorEntityID;
2159 
2160       AddIdentifierRef(MD->getName(), Record);
2161       Stream.EmitRecord(PPD_MACRO_DEFINITION, Record);
2162       continue;
2163     }
2164 
2165     if (MacroExpansion *ME = dyn_cast<MacroExpansion>(*E)) {
2166       Record.push_back(ME->isBuiltinMacro());
2167       if (ME->isBuiltinMacro())
2168         AddIdentifierRef(ME->getName(), Record);
2169       else
2170         Record.push_back(MacroDefinitions[ME->getDefinition()]);
2171       Stream.EmitRecord(PPD_MACRO_EXPANSION, Record);
2172       continue;
2173     }
2174 
2175     if (InclusionDirective *ID = dyn_cast<InclusionDirective>(*E)) {
2176       Record.push_back(PPD_INCLUSION_DIRECTIVE);
2177       Record.push_back(ID->getFileName().size());
2178       Record.push_back(ID->wasInQuotes());
2179       Record.push_back(static_cast<unsigned>(ID->getKind()));
2180       Record.push_back(ID->importedModule());
2181       SmallString<64> Buffer;
2182       Buffer += ID->getFileName();
2183       // Check that the FileEntry is not null because it was not resolved and
2184       // we create a PCH even with compiler errors.
2185       if (ID->getFile())
2186         Buffer += ID->getFile()->getName();
2187       Stream.EmitRecordWithBlob(InclusionAbbrev, Record, Buffer);
2188       continue;
2189     }
2190 
2191     llvm_unreachable("Unhandled PreprocessedEntity in ASTWriter");
2192   }
2193   Stream.ExitBlock();
2194 
2195   // Write the offsets table for the preprocessing record.
2196   if (NumPreprocessingRecords > 0) {
2197     assert(PreprocessedEntityOffsets.size() == NumPreprocessingRecords);
2198 
2199     // Write the offsets table for identifier IDs.
2200     using namespace llvm;
2201     BitCodeAbbrev *Abbrev = new BitCodeAbbrev();
2202     Abbrev->Add(BitCodeAbbrevOp(PPD_ENTITIES_OFFSETS));
2203     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // first pp entity
2204     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
2205     unsigned PPEOffsetAbbrev = Stream.EmitAbbrev(Abbrev);
2206 
2207     Record.clear();
2208     Record.push_back(PPD_ENTITIES_OFFSETS);
2209     Record.push_back(FirstPreprocessorEntityID - NUM_PREDEF_PP_ENTITY_IDS);
2210     Stream.EmitRecordWithBlob(PPEOffsetAbbrev, Record,
2211                               data(PreprocessedEntityOffsets));
2212   }
2213 }
2214 
2215 unsigned ASTWriter::getSubmoduleID(Module *Mod) {
2216   llvm::DenseMap<Module *, unsigned>::iterator Known = SubmoduleIDs.find(Mod);
2217   if (Known != SubmoduleIDs.end())
2218     return Known->second;
2219 
2220   return SubmoduleIDs[Mod] = NextSubmoduleID++;
2221 }
2222 
2223 unsigned ASTWriter::getExistingSubmoduleID(Module *Mod) const {
2224   if (!Mod)
2225     return 0;
2226 
2227   llvm::DenseMap<Module *, unsigned>::const_iterator
2228     Known = SubmoduleIDs.find(Mod);
2229   if (Known != SubmoduleIDs.end())
2230     return Known->second;
2231 
2232   return 0;
2233 }
2234 
2235 /// \brief Compute the number of modules within the given tree (including the
2236 /// given module).
2237 static unsigned getNumberOfModules(Module *Mod) {
2238   unsigned ChildModules = 0;
2239   for (Module::submodule_iterator Sub = Mod->submodule_begin(),
2240                                SubEnd = Mod->submodule_end();
2241        Sub != SubEnd; ++Sub)
2242     ChildModules += getNumberOfModules(*Sub);
2243 
2244   return ChildModules + 1;
2245 }
2246 
2247 void ASTWriter::WriteSubmodules(Module *WritingModule) {
2248   // Determine the dependencies of our module and each of it's submodules.
2249   // FIXME: This feels like it belongs somewhere else, but there are no
2250   // other consumers of this information.
2251   SourceManager &SrcMgr = PP->getSourceManager();
2252   ModuleMap &ModMap = PP->getHeaderSearchInfo().getModuleMap();
2253   for (const auto *I : Context->local_imports()) {
2254     if (Module *ImportedFrom
2255           = ModMap.inferModuleFromLocation(FullSourceLoc(I->getLocation(),
2256                                                          SrcMgr))) {
2257       ImportedFrom->Imports.push_back(I->getImportedModule());
2258     }
2259   }
2260 
2261   // Enter the submodule description block.
2262   Stream.EnterSubblock(SUBMODULE_BLOCK_ID, NUM_ALLOWED_ABBREVS_SIZE);
2263 
2264   // Write the abbreviations needed for the submodules block.
2265   using namespace llvm;
2266   BitCodeAbbrev *Abbrev = new BitCodeAbbrev();
2267   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_DEFINITION));
2268   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // ID
2269   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Parent
2270   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsFramework
2271   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsExplicit
2272   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsSystem
2273   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsExternC
2274   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // InferSubmodules...
2275   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // InferExplicit...
2276   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // InferExportWild...
2277   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // ConfigMacrosExh...
2278   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Name
2279   unsigned DefinitionAbbrev = Stream.EmitAbbrev(Abbrev);
2280 
2281   Abbrev = new BitCodeAbbrev();
2282   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_UMBRELLA_HEADER));
2283   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Name
2284   unsigned UmbrellaAbbrev = Stream.EmitAbbrev(Abbrev);
2285 
2286   Abbrev = new BitCodeAbbrev();
2287   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_HEADER));
2288   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Name
2289   unsigned HeaderAbbrev = Stream.EmitAbbrev(Abbrev);
2290 
2291   Abbrev = new BitCodeAbbrev();
2292   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_TOPHEADER));
2293   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Name
2294   unsigned TopHeaderAbbrev = Stream.EmitAbbrev(Abbrev);
2295 
2296   Abbrev = new BitCodeAbbrev();
2297   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_UMBRELLA_DIR));
2298   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Name
2299   unsigned UmbrellaDirAbbrev = Stream.EmitAbbrev(Abbrev);
2300 
2301   Abbrev = new BitCodeAbbrev();
2302   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_REQUIRES));
2303   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // State
2304   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));     // Feature
2305   unsigned RequiresAbbrev = Stream.EmitAbbrev(Abbrev);
2306 
2307   Abbrev = new BitCodeAbbrev();
2308   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_EXCLUDED_HEADER));
2309   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Name
2310   unsigned ExcludedHeaderAbbrev = Stream.EmitAbbrev(Abbrev);
2311 
2312   Abbrev = new BitCodeAbbrev();
2313   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_PRIVATE_HEADER));
2314   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Name
2315   unsigned PrivateHeaderAbbrev = Stream.EmitAbbrev(Abbrev);
2316 
2317   Abbrev = new BitCodeAbbrev();
2318   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_LINK_LIBRARY));
2319   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsFramework
2320   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));     // Name
2321   unsigned LinkLibraryAbbrev = Stream.EmitAbbrev(Abbrev);
2322 
2323   Abbrev = new BitCodeAbbrev();
2324   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_CONFIG_MACRO));
2325   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));    // Macro name
2326   unsigned ConfigMacroAbbrev = Stream.EmitAbbrev(Abbrev);
2327 
2328   Abbrev = new BitCodeAbbrev();
2329   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_CONFLICT));
2330   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));  // Other module
2331   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));    // Message
2332   unsigned ConflictAbbrev = Stream.EmitAbbrev(Abbrev);
2333 
2334   // Write the submodule metadata block.
2335   RecordData Record;
2336   Record.push_back(getNumberOfModules(WritingModule));
2337   Record.push_back(FirstSubmoduleID - NUM_PREDEF_SUBMODULE_IDS);
2338   Stream.EmitRecord(SUBMODULE_METADATA, Record);
2339 
2340   // Write all of the submodules.
2341   std::queue<Module *> Q;
2342   Q.push(WritingModule);
2343   while (!Q.empty()) {
2344     Module *Mod = Q.front();
2345     Q.pop();
2346     unsigned ID = getSubmoduleID(Mod);
2347 
2348     // Emit the definition of the block.
2349     Record.clear();
2350     Record.push_back(SUBMODULE_DEFINITION);
2351     Record.push_back(ID);
2352     if (Mod->Parent) {
2353       assert(SubmoduleIDs[Mod->Parent] && "Submodule parent not written?");
2354       Record.push_back(SubmoduleIDs[Mod->Parent]);
2355     } else {
2356       Record.push_back(0);
2357     }
2358     Record.push_back(Mod->IsFramework);
2359     Record.push_back(Mod->IsExplicit);
2360     Record.push_back(Mod->IsSystem);
2361     Record.push_back(Mod->IsExternC);
2362     Record.push_back(Mod->InferSubmodules);
2363     Record.push_back(Mod->InferExplicitSubmodules);
2364     Record.push_back(Mod->InferExportWildcard);
2365     Record.push_back(Mod->ConfigMacrosExhaustive);
2366     Stream.EmitRecordWithBlob(DefinitionAbbrev, Record, Mod->Name);
2367 
2368     // Emit the requirements.
2369     for (unsigned I = 0, N = Mod->Requirements.size(); I != N; ++I) {
2370       Record.clear();
2371       Record.push_back(SUBMODULE_REQUIRES);
2372       Record.push_back(Mod->Requirements[I].second);
2373       Stream.EmitRecordWithBlob(RequiresAbbrev, Record,
2374                                 Mod->Requirements[I].first);
2375     }
2376 
2377     // Emit the umbrella header, if there is one.
2378     if (const FileEntry *UmbrellaHeader = Mod->getUmbrellaHeader()) {
2379       Record.clear();
2380       Record.push_back(SUBMODULE_UMBRELLA_HEADER);
2381       Stream.EmitRecordWithBlob(UmbrellaAbbrev, Record,
2382                                 UmbrellaHeader->getName());
2383     } else if (const DirectoryEntry *UmbrellaDir = Mod->getUmbrellaDir()) {
2384       Record.clear();
2385       Record.push_back(SUBMODULE_UMBRELLA_DIR);
2386       Stream.EmitRecordWithBlob(UmbrellaDirAbbrev, Record,
2387                                 UmbrellaDir->getName());
2388     }
2389 
2390     // Emit the headers.
2391     for (unsigned I = 0, N = Mod->NormalHeaders.size(); I != N; ++I) {
2392       Record.clear();
2393       Record.push_back(SUBMODULE_HEADER);
2394       Stream.EmitRecordWithBlob(HeaderAbbrev, Record,
2395                                 Mod->NormalHeaders[I]->getName());
2396     }
2397     // Emit the excluded headers.
2398     for (unsigned I = 0, N = Mod->ExcludedHeaders.size(); I != N; ++I) {
2399       Record.clear();
2400       Record.push_back(SUBMODULE_EXCLUDED_HEADER);
2401       Stream.EmitRecordWithBlob(ExcludedHeaderAbbrev, Record,
2402                                 Mod->ExcludedHeaders[I]->getName());
2403     }
2404     // Emit the private headers.
2405     for (unsigned I = 0, N = Mod->PrivateHeaders.size(); I != N; ++I) {
2406       Record.clear();
2407       Record.push_back(SUBMODULE_PRIVATE_HEADER);
2408       Stream.EmitRecordWithBlob(PrivateHeaderAbbrev, Record,
2409                                 Mod->PrivateHeaders[I]->getName());
2410     }
2411     ArrayRef<const FileEntry *>
2412       TopHeaders = Mod->getTopHeaders(PP->getFileManager());
2413     for (unsigned I = 0, N = TopHeaders.size(); I != N; ++I) {
2414       Record.clear();
2415       Record.push_back(SUBMODULE_TOPHEADER);
2416       Stream.EmitRecordWithBlob(TopHeaderAbbrev, Record,
2417                                 TopHeaders[I]->getName());
2418     }
2419 
2420     // Emit the imports.
2421     if (!Mod->Imports.empty()) {
2422       Record.clear();
2423       for (unsigned I = 0, N = Mod->Imports.size(); I != N; ++I) {
2424         unsigned ImportedID = getSubmoduleID(Mod->Imports[I]);
2425         assert(ImportedID && "Unknown submodule!");
2426         Record.push_back(ImportedID);
2427       }
2428       Stream.EmitRecord(SUBMODULE_IMPORTS, Record);
2429     }
2430 
2431     // Emit the exports.
2432     if (!Mod->Exports.empty()) {
2433       Record.clear();
2434       for (unsigned I = 0, N = Mod->Exports.size(); I != N; ++I) {
2435         if (Module *Exported = Mod->Exports[I].getPointer()) {
2436           unsigned ExportedID = SubmoduleIDs[Exported];
2437           assert(ExportedID > 0 && "Unknown submodule ID?");
2438           Record.push_back(ExportedID);
2439         } else {
2440           Record.push_back(0);
2441         }
2442 
2443         Record.push_back(Mod->Exports[I].getInt());
2444       }
2445       Stream.EmitRecord(SUBMODULE_EXPORTS, Record);
2446     }
2447 
2448     //FIXME: How do we emit the 'use'd modules?  They may not be submodules.
2449     // Might be unnecessary as use declarations are only used to build the
2450     // module itself.
2451 
2452     // Emit the link libraries.
2453     for (unsigned I = 0, N = Mod->LinkLibraries.size(); I != N; ++I) {
2454       Record.clear();
2455       Record.push_back(SUBMODULE_LINK_LIBRARY);
2456       Record.push_back(Mod->LinkLibraries[I].IsFramework);
2457       Stream.EmitRecordWithBlob(LinkLibraryAbbrev, Record,
2458                                 Mod->LinkLibraries[I].Library);
2459     }
2460 
2461     // Emit the conflicts.
2462     for (unsigned I = 0, N = Mod->Conflicts.size(); I != N; ++I) {
2463       Record.clear();
2464       Record.push_back(SUBMODULE_CONFLICT);
2465       unsigned OtherID = getSubmoduleID(Mod->Conflicts[I].Other);
2466       assert(OtherID && "Unknown submodule!");
2467       Record.push_back(OtherID);
2468       Stream.EmitRecordWithBlob(ConflictAbbrev, Record,
2469                                 Mod->Conflicts[I].Message);
2470     }
2471 
2472     // Emit the configuration macros.
2473     for (unsigned I = 0, N =  Mod->ConfigMacros.size(); I != N; ++I) {
2474       Record.clear();
2475       Record.push_back(SUBMODULE_CONFIG_MACRO);
2476       Stream.EmitRecordWithBlob(ConfigMacroAbbrev, Record,
2477                                 Mod->ConfigMacros[I]);
2478     }
2479 
2480     // Queue up the submodules of this module.
2481     for (Module::submodule_iterator Sub = Mod->submodule_begin(),
2482                                  SubEnd = Mod->submodule_end();
2483          Sub != SubEnd; ++Sub)
2484       Q.push(*Sub);
2485   }
2486 
2487   Stream.ExitBlock();
2488 
2489   assert((NextSubmoduleID - FirstSubmoduleID
2490             == getNumberOfModules(WritingModule)) && "Wrong # of submodules");
2491 }
2492 
2493 serialization::SubmoduleID
2494 ASTWriter::inferSubmoduleIDFromLocation(SourceLocation Loc) {
2495   if (Loc.isInvalid() || !WritingModule)
2496     return 0; // No submodule
2497 
2498   // Find the module that owns this location.
2499   ModuleMap &ModMap = PP->getHeaderSearchInfo().getModuleMap();
2500   Module *OwningMod
2501     = ModMap.inferModuleFromLocation(FullSourceLoc(Loc,PP->getSourceManager()));
2502   if (!OwningMod)
2503     return 0;
2504 
2505   // Check whether this submodule is part of our own module.
2506   if (WritingModule != OwningMod && !OwningMod->isSubModuleOf(WritingModule))
2507     return 0;
2508 
2509   return getSubmoduleID(OwningMod);
2510 }
2511 
2512 void ASTWriter::WritePragmaDiagnosticMappings(const DiagnosticsEngine &Diag,
2513                                               bool isModule) {
2514   // Make sure set diagnostic pragmas don't affect the translation unit that
2515   // imports the module.
2516   // FIXME: Make diagnostic pragma sections work properly with modules.
2517   if (isModule)
2518     return;
2519 
2520   llvm::SmallDenseMap<const DiagnosticsEngine::DiagState *, unsigned, 64>
2521       DiagStateIDMap;
2522   unsigned CurrID = 0;
2523   DiagStateIDMap[&Diag.DiagStates.front()] = ++CurrID; // the command-line one.
2524   RecordData Record;
2525   for (DiagnosticsEngine::DiagStatePointsTy::const_iterator
2526          I = Diag.DiagStatePoints.begin(), E = Diag.DiagStatePoints.end();
2527          I != E; ++I) {
2528     const DiagnosticsEngine::DiagStatePoint &point = *I;
2529     if (point.Loc.isInvalid())
2530       continue;
2531 
2532     Record.push_back(point.Loc.getRawEncoding());
2533     unsigned &DiagStateID = DiagStateIDMap[point.State];
2534     Record.push_back(DiagStateID);
2535 
2536     if (DiagStateID == 0) {
2537       DiagStateID = ++CurrID;
2538       for (DiagnosticsEngine::DiagState::const_iterator
2539              I = point.State->begin(), E = point.State->end(); I != E; ++I) {
2540         if (I->second.isPragma()) {
2541           Record.push_back(I->first);
2542           Record.push_back(I->second.getMapping());
2543         }
2544       }
2545       Record.push_back(-1); // mark the end of the diag/map pairs for this
2546                             // location.
2547     }
2548   }
2549 
2550   if (!Record.empty())
2551     Stream.EmitRecord(DIAG_PRAGMA_MAPPINGS, Record);
2552 }
2553 
2554 void ASTWriter::WriteCXXBaseSpecifiersOffsets() {
2555   if (CXXBaseSpecifiersOffsets.empty())
2556     return;
2557 
2558   RecordData Record;
2559 
2560   // Create a blob abbreviation for the C++ base specifiers offsets.
2561   using namespace llvm;
2562 
2563   BitCodeAbbrev *Abbrev = new BitCodeAbbrev();
2564   Abbrev->Add(BitCodeAbbrevOp(CXX_BASE_SPECIFIER_OFFSETS));
2565   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // size
2566   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
2567   unsigned BaseSpecifierOffsetAbbrev = Stream.EmitAbbrev(Abbrev);
2568 
2569   // Write the base specifier offsets table.
2570   Record.clear();
2571   Record.push_back(CXX_BASE_SPECIFIER_OFFSETS);
2572   Record.push_back(CXXBaseSpecifiersOffsets.size());
2573   Stream.EmitRecordWithBlob(BaseSpecifierOffsetAbbrev, Record,
2574                             data(CXXBaseSpecifiersOffsets));
2575 }
2576 
2577 //===----------------------------------------------------------------------===//
2578 // Type Serialization
2579 //===----------------------------------------------------------------------===//
2580 
2581 /// \brief Write the representation of a type to the AST stream.
2582 void ASTWriter::WriteType(QualType T) {
2583   TypeIdx &Idx = TypeIdxs[T];
2584   if (Idx.getIndex() == 0) // we haven't seen this type before.
2585     Idx = TypeIdx(NextTypeID++);
2586 
2587   assert(Idx.getIndex() >= FirstTypeID && "Re-writing a type from a prior AST");
2588 
2589   // Record the offset for this type.
2590   unsigned Index = Idx.getIndex() - FirstTypeID;
2591   if (TypeOffsets.size() == Index)
2592     TypeOffsets.push_back(Stream.GetCurrentBitNo());
2593   else if (TypeOffsets.size() < Index) {
2594     TypeOffsets.resize(Index + 1);
2595     TypeOffsets[Index] = Stream.GetCurrentBitNo();
2596   }
2597 
2598   RecordData Record;
2599 
2600   // Emit the type's representation.
2601   ASTTypeWriter W(*this, Record);
2602 
2603   if (T.hasLocalNonFastQualifiers()) {
2604     Qualifiers Qs = T.getLocalQualifiers();
2605     AddTypeRef(T.getLocalUnqualifiedType(), Record);
2606     Record.push_back(Qs.getAsOpaqueValue());
2607     W.Code = TYPE_EXT_QUAL;
2608   } else {
2609     switch (T->getTypeClass()) {
2610       // For all of the concrete, non-dependent types, call the
2611       // appropriate visitor function.
2612 #define TYPE(Class, Base) \
2613     case Type::Class: W.Visit##Class##Type(cast<Class##Type>(T)); break;
2614 #define ABSTRACT_TYPE(Class, Base)
2615 #include "clang/AST/TypeNodes.def"
2616     }
2617   }
2618 
2619   // Emit the serialized record.
2620   Stream.EmitRecord(W.Code, Record);
2621 
2622   // Flush any expressions that were written as part of this type.
2623   FlushStmts();
2624 }
2625 
2626 //===----------------------------------------------------------------------===//
2627 // Declaration Serialization
2628 //===----------------------------------------------------------------------===//
2629 
2630 /// \brief Write the block containing all of the declaration IDs
2631 /// lexically declared within the given DeclContext.
2632 ///
2633 /// \returns the offset of the DECL_CONTEXT_LEXICAL block within the
2634 /// bistream, or 0 if no block was written.
2635 uint64_t ASTWriter::WriteDeclContextLexicalBlock(ASTContext &Context,
2636                                                  DeclContext *DC) {
2637   if (DC->decls_empty())
2638     return 0;
2639 
2640   uint64_t Offset = Stream.GetCurrentBitNo();
2641   RecordData Record;
2642   Record.push_back(DECL_CONTEXT_LEXICAL);
2643   SmallVector<KindDeclIDPair, 64> Decls;
2644   for (const auto *D : DC->decls())
2645     Decls.push_back(std::make_pair(D->getKind(), GetDeclRef(D)));
2646 
2647   ++NumLexicalDeclContexts;
2648   Stream.EmitRecordWithBlob(DeclContextLexicalAbbrev, Record, data(Decls));
2649   return Offset;
2650 }
2651 
2652 void ASTWriter::WriteTypeDeclOffsets() {
2653   using namespace llvm;
2654   RecordData Record;
2655 
2656   // Write the type offsets array
2657   BitCodeAbbrev *Abbrev = new BitCodeAbbrev();
2658   Abbrev->Add(BitCodeAbbrevOp(TYPE_OFFSET));
2659   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // # of types
2660   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // base type index
2661   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // types block
2662   unsigned TypeOffsetAbbrev = Stream.EmitAbbrev(Abbrev);
2663   Record.clear();
2664   Record.push_back(TYPE_OFFSET);
2665   Record.push_back(TypeOffsets.size());
2666   Record.push_back(FirstTypeID - NUM_PREDEF_TYPE_IDS);
2667   Stream.EmitRecordWithBlob(TypeOffsetAbbrev, Record, data(TypeOffsets));
2668 
2669   // Write the declaration offsets array
2670   Abbrev = new BitCodeAbbrev();
2671   Abbrev->Add(BitCodeAbbrevOp(DECL_OFFSET));
2672   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // # of declarations
2673   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // base decl ID
2674   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // declarations block
2675   unsigned DeclOffsetAbbrev = Stream.EmitAbbrev(Abbrev);
2676   Record.clear();
2677   Record.push_back(DECL_OFFSET);
2678   Record.push_back(DeclOffsets.size());
2679   Record.push_back(FirstDeclID - NUM_PREDEF_DECL_IDS);
2680   Stream.EmitRecordWithBlob(DeclOffsetAbbrev, Record, data(DeclOffsets));
2681 }
2682 
2683 void ASTWriter::WriteFileDeclIDsMap() {
2684   using namespace llvm;
2685   RecordData Record;
2686 
2687   // Join the vectors of DeclIDs from all files.
2688   SmallVector<DeclID, 256> FileSortedIDs;
2689   for (FileDeclIDsTy::iterator
2690          FI = FileDeclIDs.begin(), FE = FileDeclIDs.end(); FI != FE; ++FI) {
2691     DeclIDInFileInfo &Info = *FI->second;
2692     Info.FirstDeclIndex = FileSortedIDs.size();
2693     for (LocDeclIDsTy::iterator
2694            DI = Info.DeclIDs.begin(), DE = Info.DeclIDs.end(); DI != DE; ++DI)
2695       FileSortedIDs.push_back(DI->second);
2696   }
2697 
2698   BitCodeAbbrev *Abbrev = new BitCodeAbbrev();
2699   Abbrev->Add(BitCodeAbbrevOp(FILE_SORTED_DECLS));
2700   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
2701   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
2702   unsigned AbbrevCode = Stream.EmitAbbrev(Abbrev);
2703   Record.push_back(FILE_SORTED_DECLS);
2704   Record.push_back(FileSortedIDs.size());
2705   Stream.EmitRecordWithBlob(AbbrevCode, Record, data(FileSortedIDs));
2706 }
2707 
2708 void ASTWriter::WriteComments() {
2709   Stream.EnterSubblock(COMMENTS_BLOCK_ID, 3);
2710   ArrayRef<RawComment *> RawComments = Context->Comments.getComments();
2711   RecordData Record;
2712   for (ArrayRef<RawComment *>::iterator I = RawComments.begin(),
2713                                         E = RawComments.end();
2714        I != E; ++I) {
2715     Record.clear();
2716     AddSourceRange((*I)->getSourceRange(), Record);
2717     Record.push_back((*I)->getKind());
2718     Record.push_back((*I)->isTrailingComment());
2719     Record.push_back((*I)->isAlmostTrailingComment());
2720     Stream.EmitRecord(COMMENTS_RAW_COMMENT, Record);
2721   }
2722   Stream.ExitBlock();
2723 }
2724 
2725 //===----------------------------------------------------------------------===//
2726 // Global Method Pool and Selector Serialization
2727 //===----------------------------------------------------------------------===//
2728 
2729 namespace {
2730 // Trait used for the on-disk hash table used in the method pool.
2731 class ASTMethodPoolTrait {
2732   ASTWriter &Writer;
2733 
2734 public:
2735   typedef Selector key_type;
2736   typedef key_type key_type_ref;
2737 
2738   struct data_type {
2739     SelectorID ID;
2740     ObjCMethodList Instance, Factory;
2741   };
2742   typedef const data_type& data_type_ref;
2743 
2744   typedef unsigned hash_value_type;
2745   typedef unsigned offset_type;
2746 
2747   explicit ASTMethodPoolTrait(ASTWriter &Writer) : Writer(Writer) { }
2748 
2749   static hash_value_type ComputeHash(Selector Sel) {
2750     return serialization::ComputeHash(Sel);
2751   }
2752 
2753   std::pair<unsigned,unsigned>
2754     EmitKeyDataLength(raw_ostream& Out, Selector Sel,
2755                       data_type_ref Methods) {
2756     using namespace llvm::support;
2757     endian::Writer<little> LE(Out);
2758     unsigned KeyLen = 2 + (Sel.getNumArgs()? Sel.getNumArgs() * 4 : 4);
2759     LE.write<uint16_t>(KeyLen);
2760     unsigned DataLen = 4 + 2 + 2; // 2 bytes for each of the method counts
2761     for (const ObjCMethodList *Method = &Methods.Instance; Method;
2762          Method = Method->getNext())
2763       if (Method->Method)
2764         DataLen += 4;
2765     for (const ObjCMethodList *Method = &Methods.Factory; Method;
2766          Method = Method->getNext())
2767       if (Method->Method)
2768         DataLen += 4;
2769     LE.write<uint16_t>(DataLen);
2770     return std::make_pair(KeyLen, DataLen);
2771   }
2772 
2773   void EmitKey(raw_ostream& Out, Selector Sel, unsigned) {
2774     using namespace llvm::support;
2775     endian::Writer<little> LE(Out);
2776     uint64_t Start = Out.tell();
2777     assert((Start >> 32) == 0 && "Selector key offset too large");
2778     Writer.SetSelectorOffset(Sel, Start);
2779     unsigned N = Sel.getNumArgs();
2780     LE.write<uint16_t>(N);
2781     if (N == 0)
2782       N = 1;
2783     for (unsigned I = 0; I != N; ++I)
2784       LE.write<uint32_t>(
2785           Writer.getIdentifierRef(Sel.getIdentifierInfoForSlot(I)));
2786   }
2787 
2788   void EmitData(raw_ostream& Out, key_type_ref,
2789                 data_type_ref Methods, unsigned DataLen) {
2790     using namespace llvm::support;
2791     endian::Writer<little> LE(Out);
2792     uint64_t Start = Out.tell(); (void)Start;
2793     LE.write<uint32_t>(Methods.ID);
2794     unsigned NumInstanceMethods = 0;
2795     for (const ObjCMethodList *Method = &Methods.Instance; Method;
2796          Method = Method->getNext())
2797       if (Method->Method)
2798         ++NumInstanceMethods;
2799 
2800     unsigned NumFactoryMethods = 0;
2801     for (const ObjCMethodList *Method = &Methods.Factory; Method;
2802          Method = Method->getNext())
2803       if (Method->Method)
2804         ++NumFactoryMethods;
2805 
2806     unsigned InstanceBits = Methods.Instance.getBits();
2807     assert(InstanceBits < 4);
2808     unsigned NumInstanceMethodsAndBits =
2809         (NumInstanceMethods << 2) | InstanceBits;
2810     unsigned FactoryBits = Methods.Factory.getBits();
2811     assert(FactoryBits < 4);
2812     unsigned NumFactoryMethodsAndBits = (NumFactoryMethods << 2) | FactoryBits;
2813     LE.write<uint16_t>(NumInstanceMethodsAndBits);
2814     LE.write<uint16_t>(NumFactoryMethodsAndBits);
2815     for (const ObjCMethodList *Method = &Methods.Instance; Method;
2816          Method = Method->getNext())
2817       if (Method->Method)
2818         LE.write<uint32_t>(Writer.getDeclID(Method->Method));
2819     for (const ObjCMethodList *Method = &Methods.Factory; Method;
2820          Method = Method->getNext())
2821       if (Method->Method)
2822         LE.write<uint32_t>(Writer.getDeclID(Method->Method));
2823 
2824     assert(Out.tell() - Start == DataLen && "Data length is wrong");
2825   }
2826 };
2827 } // end anonymous namespace
2828 
2829 /// \brief Write ObjC data: selectors and the method pool.
2830 ///
2831 /// The method pool contains both instance and factory methods, stored
2832 /// in an on-disk hash table indexed by the selector. The hash table also
2833 /// contains an empty entry for every other selector known to Sema.
2834 void ASTWriter::WriteSelectors(Sema &SemaRef) {
2835   using namespace llvm;
2836 
2837   // Do we have to do anything at all?
2838   if (SemaRef.MethodPool.empty() && SelectorIDs.empty())
2839     return;
2840   unsigned NumTableEntries = 0;
2841   // Create and write out the blob that contains selectors and the method pool.
2842   {
2843     llvm::OnDiskChainedHashTableGenerator<ASTMethodPoolTrait> Generator;
2844     ASTMethodPoolTrait Trait(*this);
2845 
2846     // Create the on-disk hash table representation. We walk through every
2847     // selector we've seen and look it up in the method pool.
2848     SelectorOffsets.resize(NextSelectorID - FirstSelectorID);
2849     for (llvm::DenseMap<Selector, SelectorID>::iterator
2850              I = SelectorIDs.begin(), E = SelectorIDs.end();
2851          I != E; ++I) {
2852       Selector S = I->first;
2853       Sema::GlobalMethodPool::iterator F = SemaRef.MethodPool.find(S);
2854       ASTMethodPoolTrait::data_type Data = {
2855         I->second,
2856         ObjCMethodList(),
2857         ObjCMethodList()
2858       };
2859       if (F != SemaRef.MethodPool.end()) {
2860         Data.Instance = F->second.first;
2861         Data.Factory = F->second.second;
2862       }
2863       // Only write this selector if it's not in an existing AST or something
2864       // changed.
2865       if (Chain && I->second < FirstSelectorID) {
2866         // Selector already exists. Did it change?
2867         bool changed = false;
2868         for (ObjCMethodList *M = &Data.Instance; !changed && M && M->Method;
2869              M = M->getNext()) {
2870           if (!M->Method->isFromASTFile())
2871             changed = true;
2872         }
2873         for (ObjCMethodList *M = &Data.Factory; !changed && M && M->Method;
2874              M = M->getNext()) {
2875           if (!M->Method->isFromASTFile())
2876             changed = true;
2877         }
2878         if (!changed)
2879           continue;
2880       } else if (Data.Instance.Method || Data.Factory.Method) {
2881         // A new method pool entry.
2882         ++NumTableEntries;
2883       }
2884       Generator.insert(S, Data, Trait);
2885     }
2886 
2887     // Create the on-disk hash table in a buffer.
2888     SmallString<4096> MethodPool;
2889     uint32_t BucketOffset;
2890     {
2891       using namespace llvm::support;
2892       ASTMethodPoolTrait Trait(*this);
2893       llvm::raw_svector_ostream Out(MethodPool);
2894       // Make sure that no bucket is at offset 0
2895       endian::Writer<little>(Out).write<uint32_t>(0);
2896       BucketOffset = Generator.Emit(Out, Trait);
2897     }
2898 
2899     // Create a blob abbreviation
2900     BitCodeAbbrev *Abbrev = new BitCodeAbbrev();
2901     Abbrev->Add(BitCodeAbbrevOp(METHOD_POOL));
2902     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
2903     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
2904     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
2905     unsigned MethodPoolAbbrev = Stream.EmitAbbrev(Abbrev);
2906 
2907     // Write the method pool
2908     RecordData Record;
2909     Record.push_back(METHOD_POOL);
2910     Record.push_back(BucketOffset);
2911     Record.push_back(NumTableEntries);
2912     Stream.EmitRecordWithBlob(MethodPoolAbbrev, Record, MethodPool.str());
2913 
2914     // Create a blob abbreviation for the selector table offsets.
2915     Abbrev = new BitCodeAbbrev();
2916     Abbrev->Add(BitCodeAbbrevOp(SELECTOR_OFFSETS));
2917     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // size
2918     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // first ID
2919     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
2920     unsigned SelectorOffsetAbbrev = Stream.EmitAbbrev(Abbrev);
2921 
2922     // Write the selector offsets table.
2923     Record.clear();
2924     Record.push_back(SELECTOR_OFFSETS);
2925     Record.push_back(SelectorOffsets.size());
2926     Record.push_back(FirstSelectorID - NUM_PREDEF_SELECTOR_IDS);
2927     Stream.EmitRecordWithBlob(SelectorOffsetAbbrev, Record,
2928                               data(SelectorOffsets));
2929   }
2930 }
2931 
2932 /// \brief Write the selectors referenced in @selector expression into AST file.
2933 void ASTWriter::WriteReferencedSelectorsPool(Sema &SemaRef) {
2934   using namespace llvm;
2935   if (SemaRef.ReferencedSelectors.empty())
2936     return;
2937 
2938   RecordData Record;
2939 
2940   // Note: this writes out all references even for a dependent AST. But it is
2941   // very tricky to fix, and given that @selector shouldn't really appear in
2942   // headers, probably not worth it. It's not a correctness issue.
2943   for (DenseMap<Selector, SourceLocation>::iterator S =
2944        SemaRef.ReferencedSelectors.begin(),
2945        E = SemaRef.ReferencedSelectors.end(); S != E; ++S) {
2946     Selector Sel = (*S).first;
2947     SourceLocation Loc = (*S).second;
2948     AddSelectorRef(Sel, Record);
2949     AddSourceLocation(Loc, Record);
2950   }
2951   Stream.EmitRecord(REFERENCED_SELECTOR_POOL, Record);
2952 }
2953 
2954 //===----------------------------------------------------------------------===//
2955 // Identifier Table Serialization
2956 //===----------------------------------------------------------------------===//
2957 
2958 namespace {
2959 class ASTIdentifierTableTrait {
2960   ASTWriter &Writer;
2961   Preprocessor &PP;
2962   IdentifierResolver &IdResolver;
2963   bool IsModule;
2964 
2965   /// \brief Determines whether this is an "interesting" identifier
2966   /// that needs a full IdentifierInfo structure written into the hash
2967   /// table.
2968   bool isInterestingIdentifier(IdentifierInfo *II, MacroDirective *&Macro) {
2969     if (II->isPoisoned() ||
2970         II->isExtensionToken() ||
2971         II->getObjCOrBuiltinID() ||
2972         II->hasRevertedTokenIDToIdentifier() ||
2973         II->getFETokenInfo<void>())
2974       return true;
2975 
2976     return hadMacroDefinition(II, Macro);
2977   }
2978 
2979   bool hadMacroDefinition(IdentifierInfo *II, MacroDirective *&Macro) {
2980     if (!II->hadMacroDefinition())
2981       return false;
2982 
2983     if (Macro || (Macro = PP.getMacroDirectiveHistory(II))) {
2984       if (!IsModule)
2985         return !shouldIgnoreMacro(Macro, IsModule, PP);
2986       SubmoduleID ModID;
2987       if (getFirstPublicSubmoduleMacro(Macro, ModID))
2988         return true;
2989     }
2990 
2991     return false;
2992   }
2993 
2994   typedef llvm::SmallVectorImpl<SubmoduleID> OverriddenList;
2995 
2996   MacroDirective *
2997   getFirstPublicSubmoduleMacro(MacroDirective *MD, SubmoduleID &ModID) {
2998     ModID = 0;
2999     llvm::SmallVector<SubmoduleID, 1> Overridden;
3000     if (MacroDirective *NextMD = getPublicSubmoduleMacro(MD, ModID, Overridden))
3001       if (!shouldIgnoreMacro(NextMD, IsModule, PP))
3002         return NextMD;
3003     return 0;
3004   }
3005 
3006   MacroDirective *
3007   getNextPublicSubmoduleMacro(MacroDirective *MD, SubmoduleID &ModID,
3008                               OverriddenList &Overridden) {
3009     if (MacroDirective *NextMD =
3010             getPublicSubmoduleMacro(MD->getPrevious(), ModID, Overridden))
3011       if (!shouldIgnoreMacro(NextMD, IsModule, PP))
3012         return NextMD;
3013     return 0;
3014   }
3015 
3016   /// \brief Traverses the macro directives history and returns the latest
3017   /// public macro definition or undefinition that is not in ModID.
3018   /// A macro that is defined in submodule A and undefined in submodule B
3019   /// will still be considered as defined/exported from submodule A.
3020   /// ModID is updated to the module containing the returned directive.
3021   ///
3022   /// FIXME: This process breaks down if a module defines a macro, imports
3023   ///        another submodule that changes the macro, then changes the
3024   ///        macro again itself.
3025   MacroDirective *getPublicSubmoduleMacro(MacroDirective *MD,
3026                                           SubmoduleID &ModID,
3027                                           OverriddenList &Overridden) {
3028     if (!MD)
3029       return 0;
3030 
3031     Overridden.clear();
3032     SubmoduleID OrigModID = ModID;
3033     Optional<bool> IsPublic;
3034     for (; MD; MD = MD->getPrevious()) {
3035       SubmoduleID ThisModID = getSubmoduleID(MD);
3036       if (ThisModID == 0) {
3037         IsPublic = Optional<bool>();
3038         continue;
3039       }
3040       if (ThisModID != ModID) {
3041         ModID = ThisModID;
3042         IsPublic = Optional<bool>();
3043       }
3044 
3045       // If this is a definition from a submodule import, that submodule's
3046       // definition is overridden by the definition or undefinition that we
3047       // started with.
3048       // FIXME: This should only apply to macros defined in OrigModID.
3049       // We can't do that currently, because a #include of a different submodule
3050       // of the same module just leaks through macros instead of providing new
3051       // DefMacroDirectives for them.
3052       if (DefMacroDirective *DefMD = dyn_cast<DefMacroDirective>(MD)) {
3053         // Figure out which submodule the macro was originally defined within.
3054         SubmoduleID SourceID = DefMD->getInfo()->getOwningModuleID();
3055         if (!SourceID) {
3056           SourceLocation DefLoc = DefMD->getInfo()->getDefinitionLoc();
3057           if (DefLoc == MD->getLocation())
3058             SourceID = ThisModID;
3059           else
3060             SourceID = Writer.inferSubmoduleIDFromLocation(DefLoc);
3061         }
3062         if (SourceID != OrigModID)
3063           Overridden.push_back(SourceID);
3064       }
3065 
3066       // We are looking for a definition in a different submodule than the one
3067       // that we started with. If a submodule has re-definitions of the same
3068       // macro, only the last definition will be used as the "exported" one.
3069       if (ModID == OrigModID)
3070         continue;
3071 
3072       // The latest visibility directive for a name in a submodule affects all
3073       // the directives that come before it.
3074       if (VisibilityMacroDirective *VisMD =
3075               dyn_cast<VisibilityMacroDirective>(MD)) {
3076         if (!IsPublic.hasValue())
3077           IsPublic = VisMD->isPublic();
3078       } else if (!IsPublic.hasValue() || IsPublic.getValue()) {
3079         // FIXME: If we find an imported macro, we should include its list of
3080         // overrides in our export.
3081         return MD;
3082       }
3083     }
3084 
3085     return 0;
3086   }
3087 
3088   SubmoduleID getSubmoduleID(MacroDirective *MD) {
3089     return Writer.inferSubmoduleIDFromLocation(MD->getLocation());
3090   }
3091 
3092 public:
3093   typedef IdentifierInfo* key_type;
3094   typedef key_type  key_type_ref;
3095 
3096   typedef IdentID data_type;
3097   typedef data_type data_type_ref;
3098 
3099   typedef unsigned hash_value_type;
3100   typedef unsigned offset_type;
3101 
3102   ASTIdentifierTableTrait(ASTWriter &Writer, Preprocessor &PP,
3103                           IdentifierResolver &IdResolver, bool IsModule)
3104     : Writer(Writer), PP(PP), IdResolver(IdResolver), IsModule(IsModule) { }
3105 
3106   static hash_value_type ComputeHash(const IdentifierInfo* II) {
3107     return llvm::HashString(II->getName());
3108   }
3109 
3110   std::pair<unsigned,unsigned>
3111   EmitKeyDataLength(raw_ostream& Out, IdentifierInfo* II, IdentID ID) {
3112     unsigned KeyLen = II->getLength() + 1;
3113     unsigned DataLen = 4; // 4 bytes for the persistent ID << 1
3114     MacroDirective *Macro = 0;
3115     if (isInterestingIdentifier(II, Macro)) {
3116       DataLen += 2; // 2 bytes for builtin ID
3117       DataLen += 2; // 2 bytes for flags
3118       if (hadMacroDefinition(II, Macro)) {
3119         DataLen += 4; // MacroDirectives offset.
3120         if (IsModule) {
3121           SubmoduleID ModID;
3122           llvm::SmallVector<SubmoduleID, 4> Overridden;
3123           for (MacroDirective *
3124                  MD = getFirstPublicSubmoduleMacro(Macro, ModID);
3125                  MD; MD = getNextPublicSubmoduleMacro(MD, ModID, Overridden)) {
3126             // Previous macro's overrides.
3127             if (!Overridden.empty())
3128               DataLen += 4 * (1 + Overridden.size());
3129             DataLen += 4; // MacroInfo ID or ModuleID.
3130           }
3131           // Previous macro's overrides.
3132           if (!Overridden.empty())
3133             DataLen += 4 * (1 + Overridden.size());
3134           DataLen += 4;
3135         }
3136       }
3137 
3138       for (IdentifierResolver::iterator D = IdResolver.begin(II),
3139                                      DEnd = IdResolver.end();
3140            D != DEnd; ++D)
3141         DataLen += sizeof(DeclID);
3142     }
3143     using namespace llvm::support;
3144     endian::Writer<little> LE(Out);
3145 
3146     LE.write<uint16_t>(DataLen);
3147     // We emit the key length after the data length so that every
3148     // string is preceded by a 16-bit length. This matches the PTH
3149     // format for storing identifiers.
3150     LE.write<uint16_t>(KeyLen);
3151     return std::make_pair(KeyLen, DataLen);
3152   }
3153 
3154   void EmitKey(raw_ostream& Out, const IdentifierInfo* II,
3155                unsigned KeyLen) {
3156     // Record the location of the key data.  This is used when generating
3157     // the mapping from persistent IDs to strings.
3158     Writer.SetIdentifierOffset(II, Out.tell());
3159     Out.write(II->getNameStart(), KeyLen);
3160   }
3161 
3162   static void emitMacroOverrides(raw_ostream &Out,
3163                                  llvm::ArrayRef<SubmoduleID> Overridden) {
3164     if (!Overridden.empty()) {
3165       using namespace llvm::support;
3166       endian::Writer<little> LE(Out);
3167       LE.write<uint32_t>(Overridden.size() | 0x80000000U);
3168       for (unsigned I = 0, N = Overridden.size(); I != N; ++I)
3169         LE.write<uint32_t>(Overridden[I]);
3170     }
3171   }
3172 
3173   void EmitData(raw_ostream& Out, IdentifierInfo* II,
3174                 IdentID ID, unsigned) {
3175     using namespace llvm::support;
3176     endian::Writer<little> LE(Out);
3177     MacroDirective *Macro = 0;
3178     if (!isInterestingIdentifier(II, Macro)) {
3179       LE.write<uint32_t>(ID << 1);
3180       return;
3181     }
3182 
3183     LE.write<uint32_t>((ID << 1) | 0x01);
3184     uint32_t Bits = (uint32_t)II->getObjCOrBuiltinID();
3185     assert((Bits & 0xffff) == Bits && "ObjCOrBuiltinID too big for ASTReader.");
3186     LE.write<uint16_t>(Bits);
3187     Bits = 0;
3188     bool HadMacroDefinition = hadMacroDefinition(II, Macro);
3189     Bits = (Bits << 1) | unsigned(HadMacroDefinition);
3190     Bits = (Bits << 1) | unsigned(IsModule);
3191     Bits = (Bits << 1) | unsigned(II->isExtensionToken());
3192     Bits = (Bits << 1) | unsigned(II->isPoisoned());
3193     Bits = (Bits << 1) | unsigned(II->hasRevertedTokenIDToIdentifier());
3194     Bits = (Bits << 1) | unsigned(II->isCPlusPlusOperatorKeyword());
3195     LE.write<uint16_t>(Bits);
3196 
3197     if (HadMacroDefinition) {
3198       LE.write<uint32_t>(Writer.getMacroDirectivesOffset(II));
3199       if (IsModule) {
3200         // Write the IDs of macros coming from different submodules.
3201         SubmoduleID ModID;
3202         llvm::SmallVector<SubmoduleID, 4> Overridden;
3203         for (MacroDirective *
3204                MD = getFirstPublicSubmoduleMacro(Macro, ModID);
3205                MD; MD = getNextPublicSubmoduleMacro(MD, ModID, Overridden)) {
3206           MacroID InfoID = 0;
3207           emitMacroOverrides(Out, Overridden);
3208           if (DefMacroDirective *DefMD = dyn_cast<DefMacroDirective>(MD)) {
3209             InfoID = Writer.getMacroID(DefMD->getInfo());
3210             assert(InfoID);
3211             LE.write<uint32_t>(InfoID << 1);
3212           } else {
3213             assert(isa<UndefMacroDirective>(MD));
3214             LE.write<uint32_t>((ModID << 1) | 1);
3215           }
3216         }
3217         emitMacroOverrides(Out, Overridden);
3218         LE.write<uint32_t>(0);
3219       }
3220     }
3221 
3222     // Emit the declaration IDs in reverse order, because the
3223     // IdentifierResolver provides the declarations as they would be
3224     // visible (e.g., the function "stat" would come before the struct
3225     // "stat"), but the ASTReader adds declarations to the end of the list
3226     // (so we need to see the struct "status" before the function "status").
3227     // Only emit declarations that aren't from a chained PCH, though.
3228     SmallVector<Decl *, 16> Decls(IdResolver.begin(II),
3229                                   IdResolver.end());
3230     for (SmallVectorImpl<Decl *>::reverse_iterator D = Decls.rbegin(),
3231                                                 DEnd = Decls.rend();
3232          D != DEnd; ++D)
3233       LE.write<uint32_t>(Writer.getDeclID(getMostRecentLocalDecl(*D)));
3234   }
3235 
3236   /// \brief Returns the most recent local decl or the given decl if there are
3237   /// no local ones. The given decl is assumed to be the most recent one.
3238   Decl *getMostRecentLocalDecl(Decl *Orig) {
3239     // The only way a "from AST file" decl would be more recent from a local one
3240     // is if it came from a module.
3241     if (!PP.getLangOpts().Modules)
3242       return Orig;
3243 
3244     // Look for a local in the decl chain.
3245     for (Decl *D = Orig; D; D = D->getPreviousDecl()) {
3246       if (!D->isFromASTFile())
3247         return D;
3248       // If we come up a decl from a (chained-)PCH stop since we won't find a
3249       // local one.
3250       if (D->getOwningModuleID() == 0)
3251         break;
3252     }
3253 
3254     return Orig;
3255   }
3256 };
3257 } // end anonymous namespace
3258 
3259 /// \brief Write the identifier table into the AST file.
3260 ///
3261 /// The identifier table consists of a blob containing string data
3262 /// (the actual identifiers themselves) and a separate "offsets" index
3263 /// that maps identifier IDs to locations within the blob.
3264 void ASTWriter::WriteIdentifierTable(Preprocessor &PP,
3265                                      IdentifierResolver &IdResolver,
3266                                      bool IsModule) {
3267   using namespace llvm;
3268 
3269   // Create and write out the blob that contains the identifier
3270   // strings.
3271   {
3272     llvm::OnDiskChainedHashTableGenerator<ASTIdentifierTableTrait> Generator;
3273     ASTIdentifierTableTrait Trait(*this, PP, IdResolver, IsModule);
3274 
3275     // Look for any identifiers that were named while processing the
3276     // headers, but are otherwise not needed. We add these to the hash
3277     // table to enable checking of the predefines buffer in the case
3278     // where the user adds new macro definitions when building the AST
3279     // file.
3280     for (IdentifierTable::iterator ID = PP.getIdentifierTable().begin(),
3281                                 IDEnd = PP.getIdentifierTable().end();
3282          ID != IDEnd; ++ID)
3283       getIdentifierRef(ID->second);
3284 
3285     // Create the on-disk hash table representation. We only store offsets
3286     // for identifiers that appear here for the first time.
3287     IdentifierOffsets.resize(NextIdentID - FirstIdentID);
3288     for (llvm::DenseMap<const IdentifierInfo *, IdentID>::iterator
3289            ID = IdentifierIDs.begin(), IDEnd = IdentifierIDs.end();
3290          ID != IDEnd; ++ID) {
3291       assert(ID->first && "NULL identifier in identifier table");
3292       if (!Chain || !ID->first->isFromAST() ||
3293           ID->first->hasChangedSinceDeserialization())
3294         Generator.insert(const_cast<IdentifierInfo *>(ID->first), ID->second,
3295                          Trait);
3296     }
3297 
3298     // Create the on-disk hash table in a buffer.
3299     SmallString<4096> IdentifierTable;
3300     uint32_t BucketOffset;
3301     {
3302       using namespace llvm::support;
3303       ASTIdentifierTableTrait Trait(*this, PP, IdResolver, IsModule);
3304       llvm::raw_svector_ostream Out(IdentifierTable);
3305       // Make sure that no bucket is at offset 0
3306       endian::Writer<little>(Out).write<uint32_t>(0);
3307       BucketOffset = Generator.Emit(Out, Trait);
3308     }
3309 
3310     // Create a blob abbreviation
3311     BitCodeAbbrev *Abbrev = new BitCodeAbbrev();
3312     Abbrev->Add(BitCodeAbbrevOp(IDENTIFIER_TABLE));
3313     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
3314     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
3315     unsigned IDTableAbbrev = Stream.EmitAbbrev(Abbrev);
3316 
3317     // Write the identifier table
3318     RecordData Record;
3319     Record.push_back(IDENTIFIER_TABLE);
3320     Record.push_back(BucketOffset);
3321     Stream.EmitRecordWithBlob(IDTableAbbrev, Record, IdentifierTable.str());
3322   }
3323 
3324   // Write the offsets table for identifier IDs.
3325   BitCodeAbbrev *Abbrev = new BitCodeAbbrev();
3326   Abbrev->Add(BitCodeAbbrevOp(IDENTIFIER_OFFSET));
3327   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // # of identifiers
3328   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // first ID
3329   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
3330   unsigned IdentifierOffsetAbbrev = Stream.EmitAbbrev(Abbrev);
3331 
3332 #ifndef NDEBUG
3333   for (unsigned I = 0, N = IdentifierOffsets.size(); I != N; ++I)
3334     assert(IdentifierOffsets[I] && "Missing identifier offset?");
3335 #endif
3336 
3337   RecordData Record;
3338   Record.push_back(IDENTIFIER_OFFSET);
3339   Record.push_back(IdentifierOffsets.size());
3340   Record.push_back(FirstIdentID - NUM_PREDEF_IDENT_IDS);
3341   Stream.EmitRecordWithBlob(IdentifierOffsetAbbrev, Record,
3342                             data(IdentifierOffsets));
3343 }
3344 
3345 //===----------------------------------------------------------------------===//
3346 // DeclContext's Name Lookup Table Serialization
3347 //===----------------------------------------------------------------------===//
3348 
3349 namespace {
3350 // Trait used for the on-disk hash table used in the method pool.
3351 class ASTDeclContextNameLookupTrait {
3352   ASTWriter &Writer;
3353 
3354 public:
3355   typedef DeclarationName key_type;
3356   typedef key_type key_type_ref;
3357 
3358   typedef DeclContext::lookup_result data_type;
3359   typedef const data_type& data_type_ref;
3360 
3361   typedef unsigned hash_value_type;
3362   typedef unsigned offset_type;
3363 
3364   explicit ASTDeclContextNameLookupTrait(ASTWriter &Writer) : Writer(Writer) { }
3365 
3366   hash_value_type ComputeHash(DeclarationName Name) {
3367     llvm::FoldingSetNodeID ID;
3368     ID.AddInteger(Name.getNameKind());
3369 
3370     switch (Name.getNameKind()) {
3371     case DeclarationName::Identifier:
3372       ID.AddString(Name.getAsIdentifierInfo()->getName());
3373       break;
3374     case DeclarationName::ObjCZeroArgSelector:
3375     case DeclarationName::ObjCOneArgSelector:
3376     case DeclarationName::ObjCMultiArgSelector:
3377       ID.AddInteger(serialization::ComputeHash(Name.getObjCSelector()));
3378       break;
3379     case DeclarationName::CXXConstructorName:
3380     case DeclarationName::CXXDestructorName:
3381     case DeclarationName::CXXConversionFunctionName:
3382       break;
3383     case DeclarationName::CXXOperatorName:
3384       ID.AddInteger(Name.getCXXOverloadedOperator());
3385       break;
3386     case DeclarationName::CXXLiteralOperatorName:
3387       ID.AddString(Name.getCXXLiteralIdentifier()->getName());
3388     case DeclarationName::CXXUsingDirective:
3389       break;
3390     }
3391 
3392     return ID.ComputeHash();
3393   }
3394 
3395   std::pair<unsigned,unsigned>
3396     EmitKeyDataLength(raw_ostream& Out, DeclarationName Name,
3397                       data_type_ref Lookup) {
3398     using namespace llvm::support;
3399     endian::Writer<little> LE(Out);
3400     unsigned KeyLen = 1;
3401     switch (Name.getNameKind()) {
3402     case DeclarationName::Identifier:
3403     case DeclarationName::ObjCZeroArgSelector:
3404     case DeclarationName::ObjCOneArgSelector:
3405     case DeclarationName::ObjCMultiArgSelector:
3406     case DeclarationName::CXXLiteralOperatorName:
3407       KeyLen += 4;
3408       break;
3409     case DeclarationName::CXXOperatorName:
3410       KeyLen += 1;
3411       break;
3412     case DeclarationName::CXXConstructorName:
3413     case DeclarationName::CXXDestructorName:
3414     case DeclarationName::CXXConversionFunctionName:
3415     case DeclarationName::CXXUsingDirective:
3416       break;
3417     }
3418     LE.write<uint16_t>(KeyLen);
3419 
3420     // 2 bytes for num of decls and 4 for each DeclID.
3421     unsigned DataLen = 2 + 4 * Lookup.size();
3422     LE.write<uint16_t>(DataLen);
3423 
3424     return std::make_pair(KeyLen, DataLen);
3425   }
3426 
3427   void EmitKey(raw_ostream& Out, DeclarationName Name, unsigned) {
3428     using namespace llvm::support;
3429     endian::Writer<little> LE(Out);
3430     LE.write<uint8_t>(Name.getNameKind());
3431     switch (Name.getNameKind()) {
3432     case DeclarationName::Identifier:
3433       LE.write<uint32_t>(Writer.getIdentifierRef(Name.getAsIdentifierInfo()));
3434       return;
3435     case DeclarationName::ObjCZeroArgSelector:
3436     case DeclarationName::ObjCOneArgSelector:
3437     case DeclarationName::ObjCMultiArgSelector:
3438       LE.write<uint32_t>(Writer.getSelectorRef(Name.getObjCSelector()));
3439       return;
3440     case DeclarationName::CXXOperatorName:
3441       assert(Name.getCXXOverloadedOperator() < NUM_OVERLOADED_OPERATORS &&
3442              "Invalid operator?");
3443       LE.write<uint8_t>(Name.getCXXOverloadedOperator());
3444       return;
3445     case DeclarationName::CXXLiteralOperatorName:
3446       LE.write<uint32_t>(Writer.getIdentifierRef(Name.getCXXLiteralIdentifier()));
3447       return;
3448     case DeclarationName::CXXConstructorName:
3449     case DeclarationName::CXXDestructorName:
3450     case DeclarationName::CXXConversionFunctionName:
3451     case DeclarationName::CXXUsingDirective:
3452       return;
3453     }
3454 
3455     llvm_unreachable("Invalid name kind?");
3456   }
3457 
3458   void EmitData(raw_ostream& Out, key_type_ref,
3459                 data_type Lookup, unsigned DataLen) {
3460     using namespace llvm::support;
3461     endian::Writer<little> LE(Out);
3462     uint64_t Start = Out.tell(); (void)Start;
3463     LE.write<uint16_t>(Lookup.size());
3464     for (DeclContext::lookup_iterator I = Lookup.begin(), E = Lookup.end();
3465          I != E; ++I)
3466       LE.write<uint32_t>(Writer.GetDeclRef(*I));
3467 
3468     assert(Out.tell() - Start == DataLen && "Data length is wrong");
3469   }
3470 };
3471 } // end anonymous namespace
3472 
3473 template<typename Visitor>
3474 static void visitLocalLookupResults(const DeclContext *ConstDC,
3475                                     bool NeedToReconcileExternalVisibleStorage,
3476                                     Visitor AddLookupResult) {
3477   // FIXME: We need to build the lookups table, which is logically const.
3478   DeclContext *DC = const_cast<DeclContext*>(ConstDC);
3479   assert(DC == DC->getPrimaryContext() && "only primary DC has lookup table");
3480 
3481   SmallVector<DeclarationName, 16> ExternalNames;
3482   for (auto &Lookup : *DC->buildLookup()) {
3483     if (Lookup.second.hasExternalDecls() ||
3484         NeedToReconcileExternalVisibleStorage) {
3485       // We don't know for sure what declarations are found by this name,
3486       // because the external source might have a different set from the set
3487       // that are in the lookup map, and we can't update it now without
3488       // risking invalidating our lookup iterator. So add it to a queue to
3489       // deal with later.
3490       ExternalNames.push_back(Lookup.first);
3491       continue;
3492     }
3493 
3494     AddLookupResult(Lookup.first, Lookup.second.getLookupResult());
3495   }
3496 
3497   // Add the names we needed to defer. Note, this shouldn't add any new decls
3498   // to the list we need to serialize: any new declarations we find here should
3499   // be imported from an external source.
3500   // FIXME: What if the external source isn't an ASTReader?
3501   for (const auto &Name : ExternalNames)
3502     AddLookupResult(Name, DC->lookup(Name));
3503 }
3504 
3505 void ASTWriter::AddUpdatedDeclContext(const DeclContext *DC) {
3506   if (UpdatedDeclContexts.insert(DC) && WritingAST) {
3507     // Ensure we emit all the visible declarations.
3508     visitLocalLookupResults(DC, DC->NeedToReconcileExternalVisibleStorage,
3509                             [&](DeclarationName Name,
3510                                 DeclContext::lookup_const_result Result) {
3511       for (auto *Decl : Result)
3512         GetDeclRef(Decl);
3513     });
3514   }
3515 }
3516 
3517 uint32_t
3518 ASTWriter::GenerateNameLookupTable(const DeclContext *DC,
3519                                    llvm::SmallVectorImpl<char> &LookupTable) {
3520   assert(!DC->LookupPtr.getInt() && "must call buildLookups first");
3521 
3522   llvm::OnDiskChainedHashTableGenerator<ASTDeclContextNameLookupTrait>
3523       Generator;
3524   ASTDeclContextNameLookupTrait Trait(*this);
3525 
3526   // Create the on-disk hash table representation.
3527   DeclarationName ConstructorName;
3528   DeclarationName ConversionName;
3529   SmallVector<NamedDecl *, 8> ConstructorDecls;
3530   SmallVector<NamedDecl *, 4> ConversionDecls;
3531 
3532   visitLocalLookupResults(DC, DC->NeedToReconcileExternalVisibleStorage,
3533                           [&](DeclarationName Name,
3534                               DeclContext::lookup_result Result) {
3535     if (Result.empty())
3536       return;
3537 
3538     // Different DeclarationName values of certain kinds are mapped to
3539     // identical serialized keys, because we don't want to use type
3540     // identifiers in the keys (since type ids are local to the module).
3541     switch (Name.getNameKind()) {
3542     case DeclarationName::CXXConstructorName:
3543       // There may be different CXXConstructorName DeclarationName values
3544       // in a DeclContext because a UsingDecl that inherits constructors
3545       // has the DeclarationName of the inherited constructors.
3546       if (!ConstructorName)
3547         ConstructorName = Name;
3548       ConstructorDecls.append(Result.begin(), Result.end());
3549       return;
3550 
3551     case DeclarationName::CXXConversionFunctionName:
3552       if (!ConversionName)
3553         ConversionName = Name;
3554       ConversionDecls.append(Result.begin(), Result.end());
3555       return;
3556 
3557     default:
3558       break;
3559     }
3560 
3561     Generator.insert(Name, Result, Trait);
3562   });
3563 
3564   // Add the constructors.
3565   if (!ConstructorDecls.empty()) {
3566     Generator.insert(ConstructorName,
3567                      DeclContext::lookup_result(ConstructorDecls.begin(),
3568                                                 ConstructorDecls.end()),
3569                      Trait);
3570   }
3571 
3572   // Add the conversion functions.
3573   if (!ConversionDecls.empty()) {
3574     Generator.insert(ConversionName,
3575                      DeclContext::lookup_result(ConversionDecls.begin(),
3576                                                 ConversionDecls.end()),
3577                      Trait);
3578   }
3579 
3580   // Create the on-disk hash table in a buffer.
3581   llvm::raw_svector_ostream Out(LookupTable);
3582   // Make sure that no bucket is at offset 0
3583   using namespace llvm::support;
3584   endian::Writer<little>(Out).write<uint32_t>(0);
3585   return Generator.Emit(Out, Trait);
3586 }
3587 
3588 /// \brief Write the block containing all of the declaration IDs
3589 /// visible from the given DeclContext.
3590 ///
3591 /// \returns the offset of the DECL_CONTEXT_VISIBLE block within the
3592 /// bitstream, or 0 if no block was written.
3593 uint64_t ASTWriter::WriteDeclContextVisibleBlock(ASTContext &Context,
3594                                                  DeclContext *DC) {
3595   if (DC->getPrimaryContext() != DC)
3596     return 0;
3597 
3598   // Since there is no name lookup into functions or methods, don't bother to
3599   // build a visible-declarations table for these entities.
3600   if (DC->isFunctionOrMethod())
3601     return 0;
3602 
3603   // If not in C++, we perform name lookup for the translation unit via the
3604   // IdentifierInfo chains, don't bother to build a visible-declarations table.
3605   if (DC->isTranslationUnit() && !Context.getLangOpts().CPlusPlus)
3606     return 0;
3607 
3608   // Serialize the contents of the mapping used for lookup. Note that,
3609   // although we have two very different code paths, the serialized
3610   // representation is the same for both cases: a declaration name,
3611   // followed by a size, followed by references to the visible
3612   // declarations that have that name.
3613   uint64_t Offset = Stream.GetCurrentBitNo();
3614   StoredDeclsMap *Map = DC->buildLookup();
3615   if (!Map || Map->empty())
3616     return 0;
3617 
3618   // Create the on-disk hash table in a buffer.
3619   SmallString<4096> LookupTable;
3620   uint32_t BucketOffset = GenerateNameLookupTable(DC, LookupTable);
3621 
3622   // Write the lookup table
3623   RecordData Record;
3624   Record.push_back(DECL_CONTEXT_VISIBLE);
3625   Record.push_back(BucketOffset);
3626   Stream.EmitRecordWithBlob(DeclContextVisibleLookupAbbrev, Record,
3627                             LookupTable.str());
3628 
3629   Stream.EmitRecord(DECL_CONTEXT_VISIBLE, Record);
3630   ++NumVisibleDeclContexts;
3631   return Offset;
3632 }
3633 
3634 /// \brief Write an UPDATE_VISIBLE block for the given context.
3635 ///
3636 /// UPDATE_VISIBLE blocks contain the declarations that are added to an existing
3637 /// DeclContext in a dependent AST file. As such, they only exist for the TU
3638 /// (in C++), for namespaces, and for classes with forward-declared unscoped
3639 /// enumeration members (in C++11).
3640 void ASTWriter::WriteDeclContextVisibleUpdate(const DeclContext *DC) {
3641   StoredDeclsMap *Map = DC->getLookupPtr();
3642   if (!Map || Map->empty())
3643     return;
3644 
3645   // Create the on-disk hash table in a buffer.
3646   SmallString<4096> LookupTable;
3647   uint32_t BucketOffset = GenerateNameLookupTable(DC, LookupTable);
3648 
3649   // Write the lookup table
3650   RecordData Record;
3651   Record.push_back(UPDATE_VISIBLE);
3652   Record.push_back(getDeclID(cast<Decl>(DC)));
3653   Record.push_back(BucketOffset);
3654   Stream.EmitRecordWithBlob(UpdateVisibleAbbrev, Record, LookupTable.str());
3655 }
3656 
3657 /// \brief Write an FP_PRAGMA_OPTIONS block for the given FPOptions.
3658 void ASTWriter::WriteFPPragmaOptions(const FPOptions &Opts) {
3659   RecordData Record;
3660   Record.push_back(Opts.fp_contract);
3661   Stream.EmitRecord(FP_PRAGMA_OPTIONS, Record);
3662 }
3663 
3664 /// \brief Write an OPENCL_EXTENSIONS block for the given OpenCLOptions.
3665 void ASTWriter::WriteOpenCLExtensions(Sema &SemaRef) {
3666   if (!SemaRef.Context.getLangOpts().OpenCL)
3667     return;
3668 
3669   const OpenCLOptions &Opts = SemaRef.getOpenCLOptions();
3670   RecordData Record;
3671 #define OPENCLEXT(nm)  Record.push_back(Opts.nm);
3672 #include "clang/Basic/OpenCLExtensions.def"
3673   Stream.EmitRecord(OPENCL_EXTENSIONS, Record);
3674 }
3675 
3676 void ASTWriter::WriteRedeclarations() {
3677   RecordData LocalRedeclChains;
3678   SmallVector<serialization::LocalRedeclarationsInfo, 2> LocalRedeclsMap;
3679 
3680   for (unsigned I = 0, N = Redeclarations.size(); I != N; ++I) {
3681     Decl *First = Redeclarations[I];
3682     assert(First->isFirstDecl() && "Not the first declaration?");
3683 
3684     Decl *MostRecent = First->getMostRecentDecl();
3685 
3686     // If we only have a single declaration, there is no point in storing
3687     // a redeclaration chain.
3688     if (First == MostRecent)
3689       continue;
3690 
3691     unsigned Offset = LocalRedeclChains.size();
3692     unsigned Size = 0;
3693     LocalRedeclChains.push_back(0); // Placeholder for the size.
3694 
3695     // Collect the set of local redeclarations of this declaration.
3696     for (Decl *Prev = MostRecent; Prev != First;
3697          Prev = Prev->getPreviousDecl()) {
3698       if (!Prev->isFromASTFile()) {
3699         AddDeclRef(Prev, LocalRedeclChains);
3700         ++Size;
3701       }
3702     }
3703 
3704     if (!First->isFromASTFile() && Chain) {
3705       Decl *FirstFromAST = MostRecent;
3706       for (Decl *Prev = MostRecent; Prev; Prev = Prev->getPreviousDecl()) {
3707         if (Prev->isFromASTFile())
3708           FirstFromAST = Prev;
3709       }
3710 
3711       Chain->MergedDecls[FirstFromAST].push_back(getDeclID(First));
3712     }
3713 
3714     LocalRedeclChains[Offset] = Size;
3715 
3716     // Reverse the set of local redeclarations, so that we store them in
3717     // order (since we found them in reverse order).
3718     std::reverse(LocalRedeclChains.end() - Size, LocalRedeclChains.end());
3719 
3720     // Add the mapping from the first ID from the AST to the set of local
3721     // declarations.
3722     LocalRedeclarationsInfo Info = { getDeclID(First), Offset };
3723     LocalRedeclsMap.push_back(Info);
3724 
3725     assert(N == Redeclarations.size() &&
3726            "Deserialized a declaration we shouldn't have");
3727   }
3728 
3729   if (LocalRedeclChains.empty())
3730     return;
3731 
3732   // Sort the local redeclarations map by the first declaration ID,
3733   // since the reader will be performing binary searches on this information.
3734   llvm::array_pod_sort(LocalRedeclsMap.begin(), LocalRedeclsMap.end());
3735 
3736   // Emit the local redeclarations map.
3737   using namespace llvm;
3738   llvm::BitCodeAbbrev *Abbrev = new BitCodeAbbrev();
3739   Abbrev->Add(BitCodeAbbrevOp(LOCAL_REDECLARATIONS_MAP));
3740   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // # of entries
3741   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
3742   unsigned AbbrevID = Stream.EmitAbbrev(Abbrev);
3743 
3744   RecordData Record;
3745   Record.push_back(LOCAL_REDECLARATIONS_MAP);
3746   Record.push_back(LocalRedeclsMap.size());
3747   Stream.EmitRecordWithBlob(AbbrevID, Record,
3748     reinterpret_cast<char*>(LocalRedeclsMap.data()),
3749     LocalRedeclsMap.size() * sizeof(LocalRedeclarationsInfo));
3750 
3751   // Emit the redeclaration chains.
3752   Stream.EmitRecord(LOCAL_REDECLARATIONS, LocalRedeclChains);
3753 }
3754 
3755 void ASTWriter::WriteObjCCategories() {
3756   SmallVector<ObjCCategoriesInfo, 2> CategoriesMap;
3757   RecordData Categories;
3758 
3759   for (unsigned I = 0, N = ObjCClassesWithCategories.size(); I != N; ++I) {
3760     unsigned Size = 0;
3761     unsigned StartIndex = Categories.size();
3762 
3763     ObjCInterfaceDecl *Class = ObjCClassesWithCategories[I];
3764 
3765     // Allocate space for the size.
3766     Categories.push_back(0);
3767 
3768     // Add the categories.
3769     for (ObjCInterfaceDecl::known_categories_iterator
3770            Cat = Class->known_categories_begin(),
3771            CatEnd = Class->known_categories_end();
3772          Cat != CatEnd; ++Cat, ++Size) {
3773       assert(getDeclID(*Cat) != 0 && "Bogus category");
3774       AddDeclRef(*Cat, Categories);
3775     }
3776 
3777     // Update the size.
3778     Categories[StartIndex] = Size;
3779 
3780     // Record this interface -> category map.
3781     ObjCCategoriesInfo CatInfo = { getDeclID(Class), StartIndex };
3782     CategoriesMap.push_back(CatInfo);
3783   }
3784 
3785   // Sort the categories map by the definition ID, since the reader will be
3786   // performing binary searches on this information.
3787   llvm::array_pod_sort(CategoriesMap.begin(), CategoriesMap.end());
3788 
3789   // Emit the categories map.
3790   using namespace llvm;
3791   llvm::BitCodeAbbrev *Abbrev = new BitCodeAbbrev();
3792   Abbrev->Add(BitCodeAbbrevOp(OBJC_CATEGORIES_MAP));
3793   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // # of entries
3794   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
3795   unsigned AbbrevID = Stream.EmitAbbrev(Abbrev);
3796 
3797   RecordData Record;
3798   Record.push_back(OBJC_CATEGORIES_MAP);
3799   Record.push_back(CategoriesMap.size());
3800   Stream.EmitRecordWithBlob(AbbrevID, Record,
3801                             reinterpret_cast<char*>(CategoriesMap.data()),
3802                             CategoriesMap.size() * sizeof(ObjCCategoriesInfo));
3803 
3804   // Emit the category lists.
3805   Stream.EmitRecord(OBJC_CATEGORIES, Categories);
3806 }
3807 
3808 void ASTWriter::WriteMergedDecls() {
3809   if (!Chain || Chain->MergedDecls.empty())
3810     return;
3811 
3812   RecordData Record;
3813   for (ASTReader::MergedDeclsMap::iterator I = Chain->MergedDecls.begin(),
3814                                         IEnd = Chain->MergedDecls.end();
3815        I != IEnd; ++I) {
3816     DeclID CanonID = I->first->isFromASTFile()? I->first->getGlobalID()
3817                                               : GetDeclRef(I->first);
3818     assert(CanonID && "Merged declaration not known?");
3819 
3820     Record.push_back(CanonID);
3821     Record.push_back(I->second.size());
3822     Record.append(I->second.begin(), I->second.end());
3823   }
3824   Stream.EmitRecord(MERGED_DECLARATIONS, Record);
3825 }
3826 
3827 void ASTWriter::WriteLateParsedTemplates(Sema &SemaRef) {
3828   Sema::LateParsedTemplateMapT &LPTMap = SemaRef.LateParsedTemplateMap;
3829 
3830   if (LPTMap.empty())
3831     return;
3832 
3833   RecordData Record;
3834   for (Sema::LateParsedTemplateMapT::iterator It = LPTMap.begin(),
3835                                               ItEnd = LPTMap.end();
3836        It != ItEnd; ++It) {
3837     LateParsedTemplate *LPT = It->second;
3838     AddDeclRef(It->first, Record);
3839     AddDeclRef(LPT->D, Record);
3840     Record.push_back(LPT->Toks.size());
3841 
3842     for (CachedTokens::iterator TokIt = LPT->Toks.begin(),
3843                                 TokEnd = LPT->Toks.end();
3844          TokIt != TokEnd; ++TokIt) {
3845       AddToken(*TokIt, Record);
3846     }
3847   }
3848   Stream.EmitRecord(LATE_PARSED_TEMPLATE, Record);
3849 }
3850 
3851 //===----------------------------------------------------------------------===//
3852 // General Serialization Routines
3853 //===----------------------------------------------------------------------===//
3854 
3855 /// \brief Write a record containing the given attributes.
3856 void ASTWriter::WriteAttributes(ArrayRef<const Attr*> Attrs,
3857                                 RecordDataImpl &Record) {
3858   Record.push_back(Attrs.size());
3859   for (ArrayRef<const Attr *>::iterator i = Attrs.begin(),
3860                                         e = Attrs.end(); i != e; ++i){
3861     const Attr *A = *i;
3862     Record.push_back(A->getKind()); // FIXME: stable encoding, target attrs
3863     AddSourceRange(A->getRange(), Record);
3864 
3865 #include "clang/Serialization/AttrPCHWrite.inc"
3866 
3867   }
3868 }
3869 
3870 void ASTWriter::AddToken(const Token &Tok, RecordDataImpl &Record) {
3871   AddSourceLocation(Tok.getLocation(), Record);
3872   Record.push_back(Tok.getLength());
3873 
3874   // FIXME: When reading literal tokens, reconstruct the literal pointer
3875   // if it is needed.
3876   AddIdentifierRef(Tok.getIdentifierInfo(), Record);
3877   // FIXME: Should translate token kind to a stable encoding.
3878   Record.push_back(Tok.getKind());
3879   // FIXME: Should translate token flags to a stable encoding.
3880   Record.push_back(Tok.getFlags());
3881 }
3882 
3883 void ASTWriter::AddString(StringRef Str, RecordDataImpl &Record) {
3884   Record.push_back(Str.size());
3885   Record.insert(Record.end(), Str.begin(), Str.end());
3886 }
3887 
3888 void ASTWriter::AddVersionTuple(const VersionTuple &Version,
3889                                 RecordDataImpl &Record) {
3890   Record.push_back(Version.getMajor());
3891   if (Optional<unsigned> Minor = Version.getMinor())
3892     Record.push_back(*Minor + 1);
3893   else
3894     Record.push_back(0);
3895   if (Optional<unsigned> Subminor = Version.getSubminor())
3896     Record.push_back(*Subminor + 1);
3897   else
3898     Record.push_back(0);
3899 }
3900 
3901 /// \brief Note that the identifier II occurs at the given offset
3902 /// within the identifier table.
3903 void ASTWriter::SetIdentifierOffset(const IdentifierInfo *II, uint32_t Offset) {
3904   IdentID ID = IdentifierIDs[II];
3905   // Only store offsets new to this AST file. Other identifier names are looked
3906   // up earlier in the chain and thus don't need an offset.
3907   if (ID >= FirstIdentID)
3908     IdentifierOffsets[ID - FirstIdentID] = Offset;
3909 }
3910 
3911 /// \brief Note that the selector Sel occurs at the given offset
3912 /// within the method pool/selector table.
3913 void ASTWriter::SetSelectorOffset(Selector Sel, uint32_t Offset) {
3914   unsigned ID = SelectorIDs[Sel];
3915   assert(ID && "Unknown selector");
3916   // Don't record offsets for selectors that are also available in a different
3917   // file.
3918   if (ID < FirstSelectorID)
3919     return;
3920   SelectorOffsets[ID - FirstSelectorID] = Offset;
3921 }
3922 
3923 ASTWriter::ASTWriter(llvm::BitstreamWriter &Stream)
3924   : Stream(Stream), Context(0), PP(0), Chain(0), WritingModule(0),
3925     WritingAST(false), DoneWritingDeclsAndTypes(false),
3926     ASTHasCompilerErrors(false),
3927     FirstDeclID(NUM_PREDEF_DECL_IDS), NextDeclID(FirstDeclID),
3928     FirstTypeID(NUM_PREDEF_TYPE_IDS), NextTypeID(FirstTypeID),
3929     FirstIdentID(NUM_PREDEF_IDENT_IDS), NextIdentID(FirstIdentID),
3930     FirstMacroID(NUM_PREDEF_MACRO_IDS), NextMacroID(FirstMacroID),
3931     FirstSubmoduleID(NUM_PREDEF_SUBMODULE_IDS),
3932     NextSubmoduleID(FirstSubmoduleID),
3933     FirstSelectorID(NUM_PREDEF_SELECTOR_IDS), NextSelectorID(FirstSelectorID),
3934     CollectedStmts(&StmtsToEmit),
3935     NumStatements(0), NumMacros(0), NumLexicalDeclContexts(0),
3936     NumVisibleDeclContexts(0),
3937     NextCXXBaseSpecifiersID(1),
3938     DeclParmVarAbbrev(0), DeclContextLexicalAbbrev(0),
3939     DeclContextVisibleLookupAbbrev(0), UpdateVisibleAbbrev(0),
3940     DeclRefExprAbbrev(0), CharacterLiteralAbbrev(0),
3941     DeclRecordAbbrev(0), IntegerLiteralAbbrev(0),
3942     DeclTypedefAbbrev(0),
3943     DeclVarAbbrev(0), DeclFieldAbbrev(0),
3944     DeclEnumAbbrev(0), DeclObjCIvarAbbrev(0)
3945 {
3946 }
3947 
3948 ASTWriter::~ASTWriter() {
3949   llvm::DeleteContainerSeconds(FileDeclIDs);
3950 }
3951 
3952 void ASTWriter::WriteAST(Sema &SemaRef,
3953                          const std::string &OutputFile,
3954                          Module *WritingModule, StringRef isysroot,
3955                          bool hasErrors) {
3956   WritingAST = true;
3957 
3958   ASTHasCompilerErrors = hasErrors;
3959 
3960   // Emit the file header.
3961   Stream.Emit((unsigned)'C', 8);
3962   Stream.Emit((unsigned)'P', 8);
3963   Stream.Emit((unsigned)'C', 8);
3964   Stream.Emit((unsigned)'H', 8);
3965 
3966   WriteBlockInfoBlock();
3967 
3968   Context = &SemaRef.Context;
3969   PP = &SemaRef.PP;
3970   this->WritingModule = WritingModule;
3971   WriteASTCore(SemaRef, isysroot, OutputFile, WritingModule);
3972   Context = 0;
3973   PP = 0;
3974   this->WritingModule = 0;
3975 
3976   WritingAST = false;
3977 }
3978 
3979 template<typename Vector>
3980 static void AddLazyVectorDecls(ASTWriter &Writer, Vector &Vec,
3981                                ASTWriter::RecordData &Record) {
3982   for (typename Vector::iterator I = Vec.begin(0, true), E = Vec.end();
3983        I != E; ++I)  {
3984     Writer.AddDeclRef(*I, Record);
3985   }
3986 }
3987 
3988 void ASTWriter::WriteASTCore(Sema &SemaRef,
3989                              StringRef isysroot,
3990                              const std::string &OutputFile,
3991                              Module *WritingModule) {
3992   using namespace llvm;
3993 
3994   bool isModule = WritingModule != 0;
3995 
3996   // Make sure that the AST reader knows to finalize itself.
3997   if (Chain)
3998     Chain->finalizeForWriting();
3999 
4000   ASTContext &Context = SemaRef.Context;
4001   Preprocessor &PP = SemaRef.PP;
4002 
4003   // Set up predefined declaration IDs.
4004   DeclIDs[Context.getTranslationUnitDecl()] = PREDEF_DECL_TRANSLATION_UNIT_ID;
4005   if (Context.ObjCIdDecl)
4006     DeclIDs[Context.ObjCIdDecl] = PREDEF_DECL_OBJC_ID_ID;
4007   if (Context.ObjCSelDecl)
4008     DeclIDs[Context.ObjCSelDecl] = PREDEF_DECL_OBJC_SEL_ID;
4009   if (Context.ObjCClassDecl)
4010     DeclIDs[Context.ObjCClassDecl] = PREDEF_DECL_OBJC_CLASS_ID;
4011   if (Context.ObjCProtocolClassDecl)
4012     DeclIDs[Context.ObjCProtocolClassDecl] = PREDEF_DECL_OBJC_PROTOCOL_ID;
4013   if (Context.Int128Decl)
4014     DeclIDs[Context.Int128Decl] = PREDEF_DECL_INT_128_ID;
4015   if (Context.UInt128Decl)
4016     DeclIDs[Context.UInt128Decl] = PREDEF_DECL_UNSIGNED_INT_128_ID;
4017   if (Context.ObjCInstanceTypeDecl)
4018     DeclIDs[Context.ObjCInstanceTypeDecl] = PREDEF_DECL_OBJC_INSTANCETYPE_ID;
4019   if (Context.BuiltinVaListDecl)
4020     DeclIDs[Context.getBuiltinVaListDecl()] = PREDEF_DECL_BUILTIN_VA_LIST_ID;
4021 
4022   if (!Chain) {
4023     // Make sure that we emit IdentifierInfos (and any attached
4024     // declarations) for builtins. We don't need to do this when we're
4025     // emitting chained PCH files, because all of the builtins will be
4026     // in the original PCH file.
4027     // FIXME: Modules won't like this at all.
4028     IdentifierTable &Table = PP.getIdentifierTable();
4029     SmallVector<const char *, 32> BuiltinNames;
4030     if (!Context.getLangOpts().NoBuiltin) {
4031       Context.BuiltinInfo.GetBuiltinNames(BuiltinNames);
4032     }
4033     for (unsigned I = 0, N = BuiltinNames.size(); I != N; ++I)
4034       getIdentifierRef(&Table.get(BuiltinNames[I]));
4035   }
4036 
4037   // If there are any out-of-date identifiers, bring them up to date.
4038   if (ExternalPreprocessorSource *ExtSource = PP.getExternalSource()) {
4039     // Find out-of-date identifiers.
4040     SmallVector<IdentifierInfo *, 4> OutOfDate;
4041     for (IdentifierTable::iterator ID = PP.getIdentifierTable().begin(),
4042                                 IDEnd = PP.getIdentifierTable().end();
4043          ID != IDEnd; ++ID) {
4044       if (ID->second->isOutOfDate())
4045         OutOfDate.push_back(ID->second);
4046     }
4047 
4048     // Update the out-of-date identifiers.
4049     for (unsigned I = 0, N = OutOfDate.size(); I != N; ++I) {
4050       ExtSource->updateOutOfDateIdentifier(*OutOfDate[I]);
4051     }
4052   }
4053 
4054   // If we saw any DeclContext updates before we started writing the AST file,
4055   // make sure all visible decls in those DeclContexts are written out.
4056   if (!UpdatedDeclContexts.empty()) {
4057     auto OldUpdatedDeclContexts = std::move(UpdatedDeclContexts);
4058     UpdatedDeclContexts.clear();
4059     for (auto *DC : OldUpdatedDeclContexts)
4060       AddUpdatedDeclContext(DC);
4061   }
4062 
4063   // Build a record containing all of the tentative definitions in this file, in
4064   // TentativeDefinitions order.  Generally, this record will be empty for
4065   // headers.
4066   RecordData TentativeDefinitions;
4067   AddLazyVectorDecls(*this, SemaRef.TentativeDefinitions, TentativeDefinitions);
4068 
4069   // Build a record containing all of the file scoped decls in this file.
4070   RecordData UnusedFileScopedDecls;
4071   if (!isModule)
4072     AddLazyVectorDecls(*this, SemaRef.UnusedFileScopedDecls,
4073                        UnusedFileScopedDecls);
4074 
4075   // Build a record containing all of the delegating constructors we still need
4076   // to resolve.
4077   RecordData DelegatingCtorDecls;
4078   if (!isModule)
4079     AddLazyVectorDecls(*this, SemaRef.DelegatingCtorDecls, DelegatingCtorDecls);
4080 
4081   // Write the set of weak, undeclared identifiers. We always write the
4082   // entire table, since later PCH files in a PCH chain are only interested in
4083   // the results at the end of the chain.
4084   RecordData WeakUndeclaredIdentifiers;
4085   if (!SemaRef.WeakUndeclaredIdentifiers.empty()) {
4086     for (llvm::DenseMap<IdentifierInfo*,WeakInfo>::iterator
4087          I = SemaRef.WeakUndeclaredIdentifiers.begin(),
4088          E = SemaRef.WeakUndeclaredIdentifiers.end(); I != E; ++I) {
4089       AddIdentifierRef(I->first, WeakUndeclaredIdentifiers);
4090       AddIdentifierRef(I->second.getAlias(), WeakUndeclaredIdentifiers);
4091       AddSourceLocation(I->second.getLocation(), WeakUndeclaredIdentifiers);
4092       WeakUndeclaredIdentifiers.push_back(I->second.getUsed());
4093     }
4094   }
4095 
4096   // Build a record containing all of the locally-scoped extern "C"
4097   // declarations in this header file. Generally, this record will be
4098   // empty.
4099   RecordData LocallyScopedExternCDecls;
4100   // FIXME: This is filling in the AST file in densemap order which is
4101   // nondeterminstic!
4102   for (llvm::DenseMap<DeclarationName, NamedDecl *>::iterator
4103          TD = SemaRef.LocallyScopedExternCDecls.begin(),
4104          TDEnd = SemaRef.LocallyScopedExternCDecls.end();
4105        TD != TDEnd; ++TD) {
4106     if (!TD->second->isFromASTFile())
4107       AddDeclRef(TD->second, LocallyScopedExternCDecls);
4108   }
4109 
4110   // Build a record containing all of the ext_vector declarations.
4111   RecordData ExtVectorDecls;
4112   AddLazyVectorDecls(*this, SemaRef.ExtVectorDecls, ExtVectorDecls);
4113 
4114   // Build a record containing all of the VTable uses information.
4115   RecordData VTableUses;
4116   if (!SemaRef.VTableUses.empty()) {
4117     for (unsigned I = 0, N = SemaRef.VTableUses.size(); I != N; ++I) {
4118       AddDeclRef(SemaRef.VTableUses[I].first, VTableUses);
4119       AddSourceLocation(SemaRef.VTableUses[I].second, VTableUses);
4120       VTableUses.push_back(SemaRef.VTablesUsed[SemaRef.VTableUses[I].first]);
4121     }
4122   }
4123 
4124   // Build a record containing all of dynamic classes declarations.
4125   RecordData DynamicClasses;
4126   AddLazyVectorDecls(*this, SemaRef.DynamicClasses, DynamicClasses);
4127 
4128   // Build a record containing all of pending implicit instantiations.
4129   RecordData PendingInstantiations;
4130   for (std::deque<Sema::PendingImplicitInstantiation>::iterator
4131          I = SemaRef.PendingInstantiations.begin(),
4132          N = SemaRef.PendingInstantiations.end(); I != N; ++I) {
4133     AddDeclRef(I->first, PendingInstantiations);
4134     AddSourceLocation(I->second, PendingInstantiations);
4135   }
4136   assert(SemaRef.PendingLocalImplicitInstantiations.empty() &&
4137          "There are local ones at end of translation unit!");
4138 
4139   // Build a record containing some declaration references.
4140   RecordData SemaDeclRefs;
4141   if (SemaRef.StdNamespace || SemaRef.StdBadAlloc) {
4142     AddDeclRef(SemaRef.getStdNamespace(), SemaDeclRefs);
4143     AddDeclRef(SemaRef.getStdBadAlloc(), SemaDeclRefs);
4144   }
4145 
4146   RecordData CUDASpecialDeclRefs;
4147   if (Context.getcudaConfigureCallDecl()) {
4148     AddDeclRef(Context.getcudaConfigureCallDecl(), CUDASpecialDeclRefs);
4149   }
4150 
4151   // Build a record containing all of the known namespaces.
4152   RecordData KnownNamespaces;
4153   for (llvm::MapVector<NamespaceDecl*, bool>::iterator
4154             I = SemaRef.KnownNamespaces.begin(),
4155          IEnd = SemaRef.KnownNamespaces.end();
4156        I != IEnd; ++I) {
4157     if (!I->second)
4158       AddDeclRef(I->first, KnownNamespaces);
4159   }
4160 
4161   // Build a record of all used, undefined objects that require definitions.
4162   RecordData UndefinedButUsed;
4163 
4164   SmallVector<std::pair<NamedDecl *, SourceLocation>, 16> Undefined;
4165   SemaRef.getUndefinedButUsed(Undefined);
4166   for (SmallVectorImpl<std::pair<NamedDecl *, SourceLocation> >::iterator
4167          I = Undefined.begin(), E = Undefined.end(); I != E; ++I) {
4168     AddDeclRef(I->first, UndefinedButUsed);
4169     AddSourceLocation(I->second, UndefinedButUsed);
4170   }
4171 
4172   // Write the control block
4173   WriteControlBlock(PP, Context, isysroot, OutputFile);
4174 
4175   // Write the remaining AST contents.
4176   RecordData Record;
4177   Stream.EnterSubblock(AST_BLOCK_ID, 5);
4178 
4179   // This is so that older clang versions, before the introduction
4180   // of the control block, can read and reject the newer PCH format.
4181   Record.clear();
4182   Record.push_back(VERSION_MAJOR);
4183   Stream.EmitRecord(METADATA_OLD_FORMAT, Record);
4184 
4185   // Create a lexical update block containing all of the declarations in the
4186   // translation unit that do not come from other AST files.
4187   const TranslationUnitDecl *TU = Context.getTranslationUnitDecl();
4188   SmallVector<KindDeclIDPair, 64> NewGlobalDecls;
4189   for (const auto *I : TU->noload_decls()) {
4190     if (!I->isFromASTFile())
4191       NewGlobalDecls.push_back(std::make_pair(I->getKind(), GetDeclRef(I)));
4192   }
4193 
4194   llvm::BitCodeAbbrev *Abv = new llvm::BitCodeAbbrev();
4195   Abv->Add(llvm::BitCodeAbbrevOp(TU_UPDATE_LEXICAL));
4196   Abv->Add(llvm::BitCodeAbbrevOp(llvm::BitCodeAbbrevOp::Blob));
4197   unsigned TuUpdateLexicalAbbrev = Stream.EmitAbbrev(Abv);
4198   Record.clear();
4199   Record.push_back(TU_UPDATE_LEXICAL);
4200   Stream.EmitRecordWithBlob(TuUpdateLexicalAbbrev, Record,
4201                             data(NewGlobalDecls));
4202 
4203   // And a visible updates block for the translation unit.
4204   Abv = new llvm::BitCodeAbbrev();
4205   Abv->Add(llvm::BitCodeAbbrevOp(UPDATE_VISIBLE));
4206   Abv->Add(llvm::BitCodeAbbrevOp(llvm::BitCodeAbbrevOp::VBR, 6));
4207   Abv->Add(llvm::BitCodeAbbrevOp(llvm::BitCodeAbbrevOp::Fixed, 32));
4208   Abv->Add(llvm::BitCodeAbbrevOp(llvm::BitCodeAbbrevOp::Blob));
4209   UpdateVisibleAbbrev = Stream.EmitAbbrev(Abv);
4210   WriteDeclContextVisibleUpdate(TU);
4211 
4212   // If the translation unit has an anonymous namespace, and we don't already
4213   // have an update block for it, write it as an update block.
4214   // FIXME: Why do we not do this if there's already an update block?
4215   if (NamespaceDecl *NS = TU->getAnonymousNamespace()) {
4216     ASTWriter::UpdateRecord &Record = DeclUpdates[TU];
4217     if (Record.empty())
4218       Record.push_back(DeclUpdate(UPD_CXX_ADDED_ANONYMOUS_NAMESPACE, NS));
4219   }
4220 
4221   // Add update records for all mangling numbers and static local numbers.
4222   // These aren't really update records, but this is a convenient way of
4223   // tagging this rare extra data onto the declarations.
4224   for (const auto &Number : Context.MangleNumbers)
4225     if (!Number.first->isFromASTFile())
4226       DeclUpdates[Number.first].push_back(DeclUpdate(UPD_MANGLING_NUMBER,
4227                                                      Number.second));
4228   for (const auto &Number : Context.StaticLocalNumbers)
4229     if (!Number.first->isFromASTFile())
4230       DeclUpdates[Number.first].push_back(DeclUpdate(UPD_STATIC_LOCAL_NUMBER,
4231                                                      Number.second));
4232 
4233   // Make sure visible decls, added to DeclContexts previously loaded from
4234   // an AST file, are registered for serialization.
4235   for (SmallVectorImpl<const Decl *>::iterator
4236          I = UpdatingVisibleDecls.begin(),
4237          E = UpdatingVisibleDecls.end(); I != E; ++I) {
4238     GetDeclRef(*I);
4239   }
4240 
4241   // Make sure all decls associated with an identifier are registered for
4242   // serialization.
4243   for (IdentifierTable::iterator ID = PP.getIdentifierTable().begin(),
4244                               IDEnd = PP.getIdentifierTable().end();
4245        ID != IDEnd; ++ID) {
4246     const IdentifierInfo *II = ID->second;
4247     if (!Chain || !II->isFromAST() || II->hasChangedSinceDeserialization()) {
4248       for (IdentifierResolver::iterator D = SemaRef.IdResolver.begin(II),
4249                                      DEnd = SemaRef.IdResolver.end();
4250            D != DEnd; ++D) {
4251         GetDeclRef(*D);
4252       }
4253     }
4254   }
4255 
4256   // Form the record of special types.
4257   RecordData SpecialTypes;
4258   AddTypeRef(Context.getRawCFConstantStringType(), SpecialTypes);
4259   AddTypeRef(Context.getFILEType(), SpecialTypes);
4260   AddTypeRef(Context.getjmp_bufType(), SpecialTypes);
4261   AddTypeRef(Context.getsigjmp_bufType(), SpecialTypes);
4262   AddTypeRef(Context.ObjCIdRedefinitionType, SpecialTypes);
4263   AddTypeRef(Context.ObjCClassRedefinitionType, SpecialTypes);
4264   AddTypeRef(Context.ObjCSelRedefinitionType, SpecialTypes);
4265   AddTypeRef(Context.getucontext_tType(), SpecialTypes);
4266 
4267   if (Chain) {
4268     // Write the mapping information describing our module dependencies and how
4269     // each of those modules were mapped into our own offset/ID space, so that
4270     // the reader can build the appropriate mapping to its own offset/ID space.
4271     // The map consists solely of a blob with the following format:
4272     // *(module-name-len:i16 module-name:len*i8
4273     //   source-location-offset:i32
4274     //   identifier-id:i32
4275     //   preprocessed-entity-id:i32
4276     //   macro-definition-id:i32
4277     //   submodule-id:i32
4278     //   selector-id:i32
4279     //   declaration-id:i32
4280     //   c++-base-specifiers-id:i32
4281     //   type-id:i32)
4282     //
4283     llvm::BitCodeAbbrev *Abbrev = new BitCodeAbbrev();
4284     Abbrev->Add(BitCodeAbbrevOp(MODULE_OFFSET_MAP));
4285     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
4286     unsigned ModuleOffsetMapAbbrev = Stream.EmitAbbrev(Abbrev);
4287     SmallString<2048> Buffer;
4288     {
4289       llvm::raw_svector_ostream Out(Buffer);
4290       for (ModuleManager::ModuleConstIterator M = Chain->ModuleMgr.begin(),
4291                                            MEnd = Chain->ModuleMgr.end();
4292            M != MEnd; ++M) {
4293         using namespace llvm::support;
4294         endian::Writer<little> LE(Out);
4295         StringRef FileName = (*M)->FileName;
4296         LE.write<uint16_t>(FileName.size());
4297         Out.write(FileName.data(), FileName.size());
4298         LE.write<uint32_t>((*M)->SLocEntryBaseOffset);
4299         LE.write<uint32_t>((*M)->BaseIdentifierID);
4300         LE.write<uint32_t>((*M)->BaseMacroID);
4301         LE.write<uint32_t>((*M)->BasePreprocessedEntityID);
4302         LE.write<uint32_t>((*M)->BaseSubmoduleID);
4303         LE.write<uint32_t>((*M)->BaseSelectorID);
4304         LE.write<uint32_t>((*M)->BaseDeclID);
4305         LE.write<uint32_t>((*M)->BaseTypeIndex);
4306       }
4307     }
4308     Record.clear();
4309     Record.push_back(MODULE_OFFSET_MAP);
4310     Stream.EmitRecordWithBlob(ModuleOffsetMapAbbrev, Record,
4311                               Buffer.data(), Buffer.size());
4312   }
4313 
4314   RecordData DeclUpdatesOffsetsRecord;
4315 
4316   // Keep writing types, declarations, and declaration update records
4317   // until we've emitted all of them.
4318   Stream.EnterSubblock(DECLTYPES_BLOCK_ID, NUM_ALLOWED_ABBREVS_SIZE);
4319   WriteDeclsBlockAbbrevs();
4320   for (DeclsToRewriteTy::iterator I = DeclsToRewrite.begin(),
4321                                   E = DeclsToRewrite.end();
4322        I != E; ++I)
4323     DeclTypesToEmit.push(const_cast<Decl*>(*I));
4324   do {
4325     WriteDeclUpdatesBlocks(DeclUpdatesOffsetsRecord);
4326     while (!DeclTypesToEmit.empty()) {
4327       DeclOrType DOT = DeclTypesToEmit.front();
4328       DeclTypesToEmit.pop();
4329       if (DOT.isType())
4330         WriteType(DOT.getType());
4331       else
4332         WriteDecl(Context, DOT.getDecl());
4333     }
4334   } while (!DeclUpdates.empty());
4335   Stream.ExitBlock();
4336 
4337   DoneWritingDeclsAndTypes = true;
4338 
4339   // These things can only be done once we've written out decls and types.
4340   WriteTypeDeclOffsets();
4341   if (!DeclUpdatesOffsetsRecord.empty())
4342     Stream.EmitRecord(DECL_UPDATE_OFFSETS, DeclUpdatesOffsetsRecord);
4343   WriteCXXBaseSpecifiersOffsets();
4344   WriteFileDeclIDsMap();
4345   WriteSourceManagerBlock(Context.getSourceManager(), PP, isysroot);
4346 
4347   WriteComments();
4348   WritePreprocessor(PP, isModule);
4349   WriteHeaderSearch(PP.getHeaderSearchInfo(), isysroot);
4350   WriteSelectors(SemaRef);
4351   WriteReferencedSelectorsPool(SemaRef);
4352   WriteIdentifierTable(PP, SemaRef.IdResolver, isModule);
4353   WriteFPPragmaOptions(SemaRef.getFPOptions());
4354   WriteOpenCLExtensions(SemaRef);
4355   WritePragmaDiagnosticMappings(Context.getDiagnostics(), isModule);
4356 
4357   // If we're emitting a module, write out the submodule information.
4358   if (WritingModule)
4359     WriteSubmodules(WritingModule);
4360 
4361   Stream.EmitRecord(SPECIAL_TYPES, SpecialTypes);
4362 
4363   // Write the record containing external, unnamed definitions.
4364   if (!EagerlyDeserializedDecls.empty())
4365     Stream.EmitRecord(EAGERLY_DESERIALIZED_DECLS, EagerlyDeserializedDecls);
4366 
4367   // Write the record containing tentative definitions.
4368   if (!TentativeDefinitions.empty())
4369     Stream.EmitRecord(TENTATIVE_DEFINITIONS, TentativeDefinitions);
4370 
4371   // Write the record containing unused file scoped decls.
4372   if (!UnusedFileScopedDecls.empty())
4373     Stream.EmitRecord(UNUSED_FILESCOPED_DECLS, UnusedFileScopedDecls);
4374 
4375   // Write the record containing weak undeclared identifiers.
4376   if (!WeakUndeclaredIdentifiers.empty())
4377     Stream.EmitRecord(WEAK_UNDECLARED_IDENTIFIERS,
4378                       WeakUndeclaredIdentifiers);
4379 
4380   // Write the record containing locally-scoped extern "C" definitions.
4381   if (!LocallyScopedExternCDecls.empty())
4382     Stream.EmitRecord(LOCALLY_SCOPED_EXTERN_C_DECLS,
4383                       LocallyScopedExternCDecls);
4384 
4385   // Write the record containing ext_vector type names.
4386   if (!ExtVectorDecls.empty())
4387     Stream.EmitRecord(EXT_VECTOR_DECLS, ExtVectorDecls);
4388 
4389   // Write the record containing VTable uses information.
4390   if (!VTableUses.empty())
4391     Stream.EmitRecord(VTABLE_USES, VTableUses);
4392 
4393   // Write the record containing dynamic classes declarations.
4394   if (!DynamicClasses.empty())
4395     Stream.EmitRecord(DYNAMIC_CLASSES, DynamicClasses);
4396 
4397   // Write the record containing pending implicit instantiations.
4398   if (!PendingInstantiations.empty())
4399     Stream.EmitRecord(PENDING_IMPLICIT_INSTANTIATIONS, PendingInstantiations);
4400 
4401   // Write the record containing declaration references of Sema.
4402   if (!SemaDeclRefs.empty())
4403     Stream.EmitRecord(SEMA_DECL_REFS, SemaDeclRefs);
4404 
4405   // Write the record containing CUDA-specific declaration references.
4406   if (!CUDASpecialDeclRefs.empty())
4407     Stream.EmitRecord(CUDA_SPECIAL_DECL_REFS, CUDASpecialDeclRefs);
4408 
4409   // Write the delegating constructors.
4410   if (!DelegatingCtorDecls.empty())
4411     Stream.EmitRecord(DELEGATING_CTORS, DelegatingCtorDecls);
4412 
4413   // Write the known namespaces.
4414   if (!KnownNamespaces.empty())
4415     Stream.EmitRecord(KNOWN_NAMESPACES, KnownNamespaces);
4416 
4417   // Write the undefined internal functions and variables, and inline functions.
4418   if (!UndefinedButUsed.empty())
4419     Stream.EmitRecord(UNDEFINED_BUT_USED, UndefinedButUsed);
4420 
4421   // Write the visible updates to DeclContexts.
4422   for (auto *DC : UpdatedDeclContexts)
4423     WriteDeclContextVisibleUpdate(DC);
4424 
4425   if (!WritingModule) {
4426     // Write the submodules that were imported, if any.
4427     struct ModuleInfo {
4428       uint64_t ID;
4429       Module *M;
4430       ModuleInfo(uint64_t ID, Module *M) : ID(ID), M(M) {}
4431     };
4432     llvm::SmallVector<ModuleInfo, 64> Imports;
4433     for (const auto *I : Context.local_imports()) {
4434       assert(SubmoduleIDs.find(I->getImportedModule()) != SubmoduleIDs.end());
4435       Imports.push_back(ModuleInfo(SubmoduleIDs[I->getImportedModule()],
4436                          I->getImportedModule()));
4437     }
4438 
4439     if (!Imports.empty()) {
4440       auto Cmp = [](const ModuleInfo &A, const ModuleInfo &B) {
4441         return A.ID < B.ID;
4442       };
4443 
4444       // Sort and deduplicate module IDs.
4445       std::sort(Imports.begin(), Imports.end(), Cmp);
4446       Imports.erase(std::unique(Imports.begin(), Imports.end(), Cmp),
4447                     Imports.end());
4448 
4449       RecordData ImportedModules;
4450       for (const auto &Import : Imports) {
4451         ImportedModules.push_back(Import.ID);
4452         // FIXME: If the module has macros imported then later has declarations
4453         // imported, this location won't be the right one as a location for the
4454         // declaration imports.
4455         AddSourceLocation(Import.M->MacroVisibilityLoc, ImportedModules);
4456       }
4457 
4458       Stream.EmitRecord(IMPORTED_MODULES, ImportedModules);
4459     }
4460   }
4461 
4462   WriteDeclReplacementsBlock();
4463   WriteRedeclarations();
4464   WriteMergedDecls();
4465   WriteObjCCategories();
4466   WriteLateParsedTemplates(SemaRef);
4467 
4468   // Some simple statistics
4469   Record.clear();
4470   Record.push_back(NumStatements);
4471   Record.push_back(NumMacros);
4472   Record.push_back(NumLexicalDeclContexts);
4473   Record.push_back(NumVisibleDeclContexts);
4474   Stream.EmitRecord(STATISTICS, Record);
4475   Stream.ExitBlock();
4476 }
4477 
4478 void ASTWriter::WriteDeclUpdatesBlocks(RecordDataImpl &OffsetsRecord) {
4479   if (DeclUpdates.empty())
4480     return;
4481 
4482   DeclUpdateMap LocalUpdates;
4483   LocalUpdates.swap(DeclUpdates);
4484 
4485   for (auto &DeclUpdate : LocalUpdates) {
4486     const Decl *D = DeclUpdate.first;
4487     if (isRewritten(D))
4488       continue; // The decl will be written completely,no need to store updates.
4489 
4490     bool HasUpdatedBody = false;
4491     RecordData Record;
4492     for (auto &Update : DeclUpdate.second) {
4493       DeclUpdateKind Kind = (DeclUpdateKind)Update.getKind();
4494 
4495       Record.push_back(Kind);
4496       switch (Kind) {
4497       case UPD_CXX_ADDED_IMPLICIT_MEMBER:
4498       case UPD_CXX_ADDED_TEMPLATE_SPECIALIZATION:
4499       case UPD_CXX_ADDED_ANONYMOUS_NAMESPACE:
4500         assert(Update.getDecl() && "no decl to add?");
4501         Record.push_back(GetDeclRef(Update.getDecl()));
4502         break;
4503 
4504       case UPD_CXX_INSTANTIATED_STATIC_DATA_MEMBER:
4505         AddSourceLocation(Update.getLoc(), Record);
4506         break;
4507 
4508       case UPD_CXX_INSTANTIATED_FUNCTION_DEFINITION:
4509         // An updated body is emitted last, so that the reader doesn't need
4510         // to skip over the lazy body to reach statements for other records.
4511         Record.pop_back();
4512         HasUpdatedBody = true;
4513         break;
4514 
4515       case UPD_CXX_INSTANTIATED_CLASS_DEFINITION: {
4516         auto *RD = cast<CXXRecordDecl>(D);
4517         AddUpdatedDeclContext(RD->getPrimaryContext());
4518         AddCXXDefinitionData(RD, Record);
4519         Record.push_back(WriteDeclContextLexicalBlock(
4520             *Context, const_cast<CXXRecordDecl *>(RD)));
4521 
4522         // This state is sometimes updated by template instantiation, when we
4523         // switch from the specialization referring to the template declaration
4524         // to it referring to the template definition.
4525         if (auto *MSInfo = RD->getMemberSpecializationInfo()) {
4526           Record.push_back(MSInfo->getTemplateSpecializationKind());
4527           AddSourceLocation(MSInfo->getPointOfInstantiation(), Record);
4528         } else {
4529           auto *Spec = cast<ClassTemplateSpecializationDecl>(RD);
4530           Record.push_back(Spec->getTemplateSpecializationKind());
4531           AddSourceLocation(Spec->getPointOfInstantiation(), Record);
4532         }
4533         Record.push_back(RD->getTagKind());
4534         AddSourceLocation(RD->getLocation(), Record);
4535         AddSourceLocation(RD->getLocStart(), Record);
4536         AddSourceLocation(RD->getRBraceLoc(), Record);
4537 
4538         // Instantiation may change attributes; write them all out afresh.
4539         Record.push_back(D->hasAttrs());
4540         if (Record.back())
4541           WriteAttributes(ArrayRef<const Attr*>(D->getAttrs().begin(),
4542                                                 D->getAttrs().size()), Record);
4543 
4544         // FIXME: Ensure we don't get here for explicit instantiations.
4545         break;
4546       }
4547 
4548       case UPD_CXX_RESOLVED_EXCEPTION_SPEC:
4549         addExceptionSpec(
4550             *this,
4551             cast<FunctionDecl>(D)->getType()->castAs<FunctionProtoType>(),
4552             Record);
4553         break;
4554 
4555       case UPD_CXX_DEDUCED_RETURN_TYPE:
4556         Record.push_back(GetOrCreateTypeID(Update.getType()));
4557         break;
4558 
4559       case UPD_DECL_MARKED_USED:
4560         break;
4561 
4562       case UPD_MANGLING_NUMBER:
4563       case UPD_STATIC_LOCAL_NUMBER:
4564         Record.push_back(Update.getNumber());
4565         break;
4566       }
4567     }
4568 
4569     if (HasUpdatedBody) {
4570       const FunctionDecl *Def = cast<FunctionDecl>(D);
4571       Record.push_back(UPD_CXX_INSTANTIATED_FUNCTION_DEFINITION);
4572       Record.push_back(Def->isInlined());
4573       AddSourceLocation(Def->getInnerLocStart(), Record);
4574       AddFunctionDefinition(Def, Record);
4575     }
4576 
4577     OffsetsRecord.push_back(GetDeclRef(D));
4578     OffsetsRecord.push_back(Stream.GetCurrentBitNo());
4579 
4580     Stream.EmitRecord(DECL_UPDATES, Record);
4581 
4582     // Flush any statements that were written as part of this update record.
4583     FlushStmts();
4584 
4585     // Flush C++ base specifiers, if there are any.
4586     FlushCXXBaseSpecifiers();
4587   }
4588 }
4589 
4590 void ASTWriter::WriteDeclReplacementsBlock() {
4591   if (ReplacedDecls.empty())
4592     return;
4593 
4594   RecordData Record;
4595   for (SmallVectorImpl<ReplacedDeclInfo>::iterator
4596          I = ReplacedDecls.begin(), E = ReplacedDecls.end(); I != E; ++I) {
4597     Record.push_back(I->ID);
4598     Record.push_back(I->Offset);
4599     Record.push_back(I->Loc);
4600   }
4601   Stream.EmitRecord(DECL_REPLACEMENTS, Record);
4602 }
4603 
4604 void ASTWriter::AddSourceLocation(SourceLocation Loc, RecordDataImpl &Record) {
4605   Record.push_back(Loc.getRawEncoding());
4606 }
4607 
4608 void ASTWriter::AddSourceRange(SourceRange Range, RecordDataImpl &Record) {
4609   AddSourceLocation(Range.getBegin(), Record);
4610   AddSourceLocation(Range.getEnd(), Record);
4611 }
4612 
4613 void ASTWriter::AddAPInt(const llvm::APInt &Value, RecordDataImpl &Record) {
4614   Record.push_back(Value.getBitWidth());
4615   const uint64_t *Words = Value.getRawData();
4616   Record.append(Words, Words + Value.getNumWords());
4617 }
4618 
4619 void ASTWriter::AddAPSInt(const llvm::APSInt &Value, RecordDataImpl &Record) {
4620   Record.push_back(Value.isUnsigned());
4621   AddAPInt(Value, Record);
4622 }
4623 
4624 void ASTWriter::AddAPFloat(const llvm::APFloat &Value, RecordDataImpl &Record) {
4625   AddAPInt(Value.bitcastToAPInt(), Record);
4626 }
4627 
4628 void ASTWriter::AddIdentifierRef(const IdentifierInfo *II, RecordDataImpl &Record) {
4629   Record.push_back(getIdentifierRef(II));
4630 }
4631 
4632 IdentID ASTWriter::getIdentifierRef(const IdentifierInfo *II) {
4633   if (II == 0)
4634     return 0;
4635 
4636   IdentID &ID = IdentifierIDs[II];
4637   if (ID == 0)
4638     ID = NextIdentID++;
4639   return ID;
4640 }
4641 
4642 MacroID ASTWriter::getMacroRef(MacroInfo *MI, const IdentifierInfo *Name) {
4643   // Don't emit builtin macros like __LINE__ to the AST file unless they
4644   // have been redefined by the header (in which case they are not
4645   // isBuiltinMacro).
4646   if (MI == 0 || MI->isBuiltinMacro())
4647     return 0;
4648 
4649   MacroID &ID = MacroIDs[MI];
4650   if (ID == 0) {
4651     ID = NextMacroID++;
4652     MacroInfoToEmitData Info = { Name, MI, ID };
4653     MacroInfosToEmit.push_back(Info);
4654   }
4655   return ID;
4656 }
4657 
4658 MacroID ASTWriter::getMacroID(MacroInfo *MI) {
4659   if (MI == 0 || MI->isBuiltinMacro())
4660     return 0;
4661 
4662   assert(MacroIDs.find(MI) != MacroIDs.end() && "Macro not emitted!");
4663   return MacroIDs[MI];
4664 }
4665 
4666 uint64_t ASTWriter::getMacroDirectivesOffset(const IdentifierInfo *Name) {
4667   assert(IdentMacroDirectivesOffsetMap[Name] && "not set!");
4668   return IdentMacroDirectivesOffsetMap[Name];
4669 }
4670 
4671 void ASTWriter::AddSelectorRef(const Selector SelRef, RecordDataImpl &Record) {
4672   Record.push_back(getSelectorRef(SelRef));
4673 }
4674 
4675 SelectorID ASTWriter::getSelectorRef(Selector Sel) {
4676   if (Sel.getAsOpaquePtr() == 0) {
4677     return 0;
4678   }
4679 
4680   SelectorID SID = SelectorIDs[Sel];
4681   if (SID == 0 && Chain) {
4682     // This might trigger a ReadSelector callback, which will set the ID for
4683     // this selector.
4684     Chain->LoadSelector(Sel);
4685     SID = SelectorIDs[Sel];
4686   }
4687   if (SID == 0) {
4688     SID = NextSelectorID++;
4689     SelectorIDs[Sel] = SID;
4690   }
4691   return SID;
4692 }
4693 
4694 void ASTWriter::AddCXXTemporary(const CXXTemporary *Temp, RecordDataImpl &Record) {
4695   AddDeclRef(Temp->getDestructor(), Record);
4696 }
4697 
4698 void ASTWriter::AddCXXBaseSpecifiersRef(CXXBaseSpecifier const *Bases,
4699                                       CXXBaseSpecifier const *BasesEnd,
4700                                         RecordDataImpl &Record) {
4701   assert(Bases != BasesEnd && "Empty base-specifier sets are not recorded");
4702   CXXBaseSpecifiersToWrite.push_back(
4703                                 QueuedCXXBaseSpecifiers(NextCXXBaseSpecifiersID,
4704                                                         Bases, BasesEnd));
4705   Record.push_back(NextCXXBaseSpecifiersID++);
4706 }
4707 
4708 void ASTWriter::AddTemplateArgumentLocInfo(TemplateArgument::ArgKind Kind,
4709                                            const TemplateArgumentLocInfo &Arg,
4710                                            RecordDataImpl &Record) {
4711   switch (Kind) {
4712   case TemplateArgument::Expression:
4713     AddStmt(Arg.getAsExpr());
4714     break;
4715   case TemplateArgument::Type:
4716     AddTypeSourceInfo(Arg.getAsTypeSourceInfo(), Record);
4717     break;
4718   case TemplateArgument::Template:
4719     AddNestedNameSpecifierLoc(Arg.getTemplateQualifierLoc(), Record);
4720     AddSourceLocation(Arg.getTemplateNameLoc(), Record);
4721     break;
4722   case TemplateArgument::TemplateExpansion:
4723     AddNestedNameSpecifierLoc(Arg.getTemplateQualifierLoc(), Record);
4724     AddSourceLocation(Arg.getTemplateNameLoc(), Record);
4725     AddSourceLocation(Arg.getTemplateEllipsisLoc(), Record);
4726     break;
4727   case TemplateArgument::Null:
4728   case TemplateArgument::Integral:
4729   case TemplateArgument::Declaration:
4730   case TemplateArgument::NullPtr:
4731   case TemplateArgument::Pack:
4732     // FIXME: Is this right?
4733     break;
4734   }
4735 }
4736 
4737 void ASTWriter::AddTemplateArgumentLoc(const TemplateArgumentLoc &Arg,
4738                                        RecordDataImpl &Record) {
4739   AddTemplateArgument(Arg.getArgument(), Record);
4740 
4741   if (Arg.getArgument().getKind() == TemplateArgument::Expression) {
4742     bool InfoHasSameExpr
4743       = Arg.getArgument().getAsExpr() == Arg.getLocInfo().getAsExpr();
4744     Record.push_back(InfoHasSameExpr);
4745     if (InfoHasSameExpr)
4746       return; // Avoid storing the same expr twice.
4747   }
4748   AddTemplateArgumentLocInfo(Arg.getArgument().getKind(), Arg.getLocInfo(),
4749                              Record);
4750 }
4751 
4752 void ASTWriter::AddTypeSourceInfo(TypeSourceInfo *TInfo,
4753                                   RecordDataImpl &Record) {
4754   if (TInfo == 0) {
4755     AddTypeRef(QualType(), Record);
4756     return;
4757   }
4758 
4759   AddTypeLoc(TInfo->getTypeLoc(), Record);
4760 }
4761 
4762 void ASTWriter::AddTypeLoc(TypeLoc TL, RecordDataImpl &Record) {
4763   AddTypeRef(TL.getType(), Record);
4764 
4765   TypeLocWriter TLW(*this, Record);
4766   for (; !TL.isNull(); TL = TL.getNextTypeLoc())
4767     TLW.Visit(TL);
4768 }
4769 
4770 void ASTWriter::AddTypeRef(QualType T, RecordDataImpl &Record) {
4771   Record.push_back(GetOrCreateTypeID(T));
4772 }
4773 
4774 TypeID ASTWriter::GetOrCreateTypeID( QualType T) {
4775   assert(Context);
4776   return MakeTypeID(*Context, T,
4777               std::bind1st(std::mem_fun(&ASTWriter::GetOrCreateTypeIdx), this));
4778 }
4779 
4780 TypeID ASTWriter::getTypeID(QualType T) const {
4781   assert(Context);
4782   return MakeTypeID(*Context, T,
4783               std::bind1st(std::mem_fun(&ASTWriter::getTypeIdx), this));
4784 }
4785 
4786 TypeIdx ASTWriter::GetOrCreateTypeIdx(QualType T) {
4787   if (T.isNull())
4788     return TypeIdx();
4789   assert(!T.getLocalFastQualifiers());
4790 
4791   TypeIdx &Idx = TypeIdxs[T];
4792   if (Idx.getIndex() == 0) {
4793     if (DoneWritingDeclsAndTypes) {
4794       assert(0 && "New type seen after serializing all the types to emit!");
4795       return TypeIdx();
4796     }
4797 
4798     // We haven't seen this type before. Assign it a new ID and put it
4799     // into the queue of types to emit.
4800     Idx = TypeIdx(NextTypeID++);
4801     DeclTypesToEmit.push(T);
4802   }
4803   return Idx;
4804 }
4805 
4806 TypeIdx ASTWriter::getTypeIdx(QualType T) const {
4807   if (T.isNull())
4808     return TypeIdx();
4809   assert(!T.getLocalFastQualifiers());
4810 
4811   TypeIdxMap::const_iterator I = TypeIdxs.find(T);
4812   assert(I != TypeIdxs.end() && "Type not emitted!");
4813   return I->second;
4814 }
4815 
4816 void ASTWriter::AddDeclRef(const Decl *D, RecordDataImpl &Record) {
4817   Record.push_back(GetDeclRef(D));
4818 }
4819 
4820 DeclID ASTWriter::GetDeclRef(const Decl *D) {
4821   assert(WritingAST && "Cannot request a declaration ID before AST writing");
4822 
4823   if (D == 0) {
4824     return 0;
4825   }
4826 
4827   // If D comes from an AST file, its declaration ID is already known and
4828   // fixed.
4829   if (D->isFromASTFile())
4830     return D->getGlobalID();
4831 
4832   assert(!(reinterpret_cast<uintptr_t>(D) & 0x01) && "Invalid decl pointer");
4833   DeclID &ID = DeclIDs[D];
4834   if (ID == 0) {
4835     if (DoneWritingDeclsAndTypes) {
4836       assert(0 && "New decl seen after serializing all the decls to emit!");
4837       return 0;
4838     }
4839 
4840     // We haven't seen this declaration before. Give it a new ID and
4841     // enqueue it in the list of declarations to emit.
4842     ID = NextDeclID++;
4843     DeclTypesToEmit.push(const_cast<Decl *>(D));
4844   }
4845 
4846   return ID;
4847 }
4848 
4849 DeclID ASTWriter::getDeclID(const Decl *D) {
4850   if (D == 0)
4851     return 0;
4852 
4853   // If D comes from an AST file, its declaration ID is already known and
4854   // fixed.
4855   if (D->isFromASTFile())
4856     return D->getGlobalID();
4857 
4858   assert(DeclIDs.find(D) != DeclIDs.end() && "Declaration not emitted!");
4859   return DeclIDs[D];
4860 }
4861 
4862 void ASTWriter::associateDeclWithFile(const Decl *D, DeclID ID) {
4863   assert(ID);
4864   assert(D);
4865 
4866   SourceLocation Loc = D->getLocation();
4867   if (Loc.isInvalid())
4868     return;
4869 
4870   // We only keep track of the file-level declarations of each file.
4871   if (!D->getLexicalDeclContext()->isFileContext())
4872     return;
4873   // FIXME: ParmVarDecls that are part of a function type of a parameter of
4874   // a function/objc method, should not have TU as lexical context.
4875   if (isa<ParmVarDecl>(D))
4876     return;
4877 
4878   SourceManager &SM = Context->getSourceManager();
4879   SourceLocation FileLoc = SM.getFileLoc(Loc);
4880   assert(SM.isLocalSourceLocation(FileLoc));
4881   FileID FID;
4882   unsigned Offset;
4883   std::tie(FID, Offset) = SM.getDecomposedLoc(FileLoc);
4884   if (FID.isInvalid())
4885     return;
4886   assert(SM.getSLocEntry(FID).isFile());
4887 
4888   DeclIDInFileInfo *&Info = FileDeclIDs[FID];
4889   if (!Info)
4890     Info = new DeclIDInFileInfo();
4891 
4892   std::pair<unsigned, serialization::DeclID> LocDecl(Offset, ID);
4893   LocDeclIDsTy &Decls = Info->DeclIDs;
4894 
4895   if (Decls.empty() || Decls.back().first <= Offset) {
4896     Decls.push_back(LocDecl);
4897     return;
4898   }
4899 
4900   LocDeclIDsTy::iterator I =
4901       std::upper_bound(Decls.begin(), Decls.end(), LocDecl, llvm::less_first());
4902 
4903   Decls.insert(I, LocDecl);
4904 }
4905 
4906 void ASTWriter::AddDeclarationName(DeclarationName Name, RecordDataImpl &Record) {
4907   // FIXME: Emit a stable enum for NameKind.  0 = Identifier etc.
4908   Record.push_back(Name.getNameKind());
4909   switch (Name.getNameKind()) {
4910   case DeclarationName::Identifier:
4911     AddIdentifierRef(Name.getAsIdentifierInfo(), Record);
4912     break;
4913 
4914   case DeclarationName::ObjCZeroArgSelector:
4915   case DeclarationName::ObjCOneArgSelector:
4916   case DeclarationName::ObjCMultiArgSelector:
4917     AddSelectorRef(Name.getObjCSelector(), Record);
4918     break;
4919 
4920   case DeclarationName::CXXConstructorName:
4921   case DeclarationName::CXXDestructorName:
4922   case DeclarationName::CXXConversionFunctionName:
4923     AddTypeRef(Name.getCXXNameType(), Record);
4924     break;
4925 
4926   case DeclarationName::CXXOperatorName:
4927     Record.push_back(Name.getCXXOverloadedOperator());
4928     break;
4929 
4930   case DeclarationName::CXXLiteralOperatorName:
4931     AddIdentifierRef(Name.getCXXLiteralIdentifier(), Record);
4932     break;
4933 
4934   case DeclarationName::CXXUsingDirective:
4935     // No extra data to emit
4936     break;
4937   }
4938 }
4939 
4940 void ASTWriter::AddDeclarationNameLoc(const DeclarationNameLoc &DNLoc,
4941                                      DeclarationName Name, RecordDataImpl &Record) {
4942   switch (Name.getNameKind()) {
4943   case DeclarationName::CXXConstructorName:
4944   case DeclarationName::CXXDestructorName:
4945   case DeclarationName::CXXConversionFunctionName:
4946     AddTypeSourceInfo(DNLoc.NamedType.TInfo, Record);
4947     break;
4948 
4949   case DeclarationName::CXXOperatorName:
4950     AddSourceLocation(
4951        SourceLocation::getFromRawEncoding(DNLoc.CXXOperatorName.BeginOpNameLoc),
4952        Record);
4953     AddSourceLocation(
4954         SourceLocation::getFromRawEncoding(DNLoc.CXXOperatorName.EndOpNameLoc),
4955         Record);
4956     break;
4957 
4958   case DeclarationName::CXXLiteralOperatorName:
4959     AddSourceLocation(
4960      SourceLocation::getFromRawEncoding(DNLoc.CXXLiteralOperatorName.OpNameLoc),
4961      Record);
4962     break;
4963 
4964   case DeclarationName::Identifier:
4965   case DeclarationName::ObjCZeroArgSelector:
4966   case DeclarationName::ObjCOneArgSelector:
4967   case DeclarationName::ObjCMultiArgSelector:
4968   case DeclarationName::CXXUsingDirective:
4969     break;
4970   }
4971 }
4972 
4973 void ASTWriter::AddDeclarationNameInfo(const DeclarationNameInfo &NameInfo,
4974                                        RecordDataImpl &Record) {
4975   AddDeclarationName(NameInfo.getName(), Record);
4976   AddSourceLocation(NameInfo.getLoc(), Record);
4977   AddDeclarationNameLoc(NameInfo.getInfo(), NameInfo.getName(), Record);
4978 }
4979 
4980 void ASTWriter::AddQualifierInfo(const QualifierInfo &Info,
4981                                  RecordDataImpl &Record) {
4982   AddNestedNameSpecifierLoc(Info.QualifierLoc, Record);
4983   Record.push_back(Info.NumTemplParamLists);
4984   for (unsigned i=0, e=Info.NumTemplParamLists; i != e; ++i)
4985     AddTemplateParameterList(Info.TemplParamLists[i], Record);
4986 }
4987 
4988 void ASTWriter::AddNestedNameSpecifier(NestedNameSpecifier *NNS,
4989                                        RecordDataImpl &Record) {
4990   // Nested name specifiers usually aren't too long. I think that 8 would
4991   // typically accommodate the vast majority.
4992   SmallVector<NestedNameSpecifier *, 8> NestedNames;
4993 
4994   // Push each of the NNS's onto a stack for serialization in reverse order.
4995   while (NNS) {
4996     NestedNames.push_back(NNS);
4997     NNS = NNS->getPrefix();
4998   }
4999 
5000   Record.push_back(NestedNames.size());
5001   while(!NestedNames.empty()) {
5002     NNS = NestedNames.pop_back_val();
5003     NestedNameSpecifier::SpecifierKind Kind = NNS->getKind();
5004     Record.push_back(Kind);
5005     switch (Kind) {
5006     case NestedNameSpecifier::Identifier:
5007       AddIdentifierRef(NNS->getAsIdentifier(), Record);
5008       break;
5009 
5010     case NestedNameSpecifier::Namespace:
5011       AddDeclRef(NNS->getAsNamespace(), Record);
5012       break;
5013 
5014     case NestedNameSpecifier::NamespaceAlias:
5015       AddDeclRef(NNS->getAsNamespaceAlias(), Record);
5016       break;
5017 
5018     case NestedNameSpecifier::TypeSpec:
5019     case NestedNameSpecifier::TypeSpecWithTemplate:
5020       AddTypeRef(QualType(NNS->getAsType(), 0), Record);
5021       Record.push_back(Kind == NestedNameSpecifier::TypeSpecWithTemplate);
5022       break;
5023 
5024     case NestedNameSpecifier::Global:
5025       // Don't need to write an associated value.
5026       break;
5027     }
5028   }
5029 }
5030 
5031 void ASTWriter::AddNestedNameSpecifierLoc(NestedNameSpecifierLoc NNS,
5032                                           RecordDataImpl &Record) {
5033   // Nested name specifiers usually aren't too long. I think that 8 would
5034   // typically accommodate the vast majority.
5035   SmallVector<NestedNameSpecifierLoc , 8> NestedNames;
5036 
5037   // Push each of the nested-name-specifiers's onto a stack for
5038   // serialization in reverse order.
5039   while (NNS) {
5040     NestedNames.push_back(NNS);
5041     NNS = NNS.getPrefix();
5042   }
5043 
5044   Record.push_back(NestedNames.size());
5045   while(!NestedNames.empty()) {
5046     NNS = NestedNames.pop_back_val();
5047     NestedNameSpecifier::SpecifierKind Kind
5048       = NNS.getNestedNameSpecifier()->getKind();
5049     Record.push_back(Kind);
5050     switch (Kind) {
5051     case NestedNameSpecifier::Identifier:
5052       AddIdentifierRef(NNS.getNestedNameSpecifier()->getAsIdentifier(), Record);
5053       AddSourceRange(NNS.getLocalSourceRange(), Record);
5054       break;
5055 
5056     case NestedNameSpecifier::Namespace:
5057       AddDeclRef(NNS.getNestedNameSpecifier()->getAsNamespace(), Record);
5058       AddSourceRange(NNS.getLocalSourceRange(), Record);
5059       break;
5060 
5061     case NestedNameSpecifier::NamespaceAlias:
5062       AddDeclRef(NNS.getNestedNameSpecifier()->getAsNamespaceAlias(), Record);
5063       AddSourceRange(NNS.getLocalSourceRange(), Record);
5064       break;
5065 
5066     case NestedNameSpecifier::TypeSpec:
5067     case NestedNameSpecifier::TypeSpecWithTemplate:
5068       Record.push_back(Kind == NestedNameSpecifier::TypeSpecWithTemplate);
5069       AddTypeLoc(NNS.getTypeLoc(), Record);
5070       AddSourceLocation(NNS.getLocalSourceRange().getEnd(), Record);
5071       break;
5072 
5073     case NestedNameSpecifier::Global:
5074       AddSourceLocation(NNS.getLocalSourceRange().getEnd(), Record);
5075       break;
5076     }
5077   }
5078 }
5079 
5080 void ASTWriter::AddTemplateName(TemplateName Name, RecordDataImpl &Record) {
5081   TemplateName::NameKind Kind = Name.getKind();
5082   Record.push_back(Kind);
5083   switch (Kind) {
5084   case TemplateName::Template:
5085     AddDeclRef(Name.getAsTemplateDecl(), Record);
5086     break;
5087 
5088   case TemplateName::OverloadedTemplate: {
5089     OverloadedTemplateStorage *OvT = Name.getAsOverloadedTemplate();
5090     Record.push_back(OvT->size());
5091     for (OverloadedTemplateStorage::iterator I = OvT->begin(), E = OvT->end();
5092            I != E; ++I)
5093       AddDeclRef(*I, Record);
5094     break;
5095   }
5096 
5097   case TemplateName::QualifiedTemplate: {
5098     QualifiedTemplateName *QualT = Name.getAsQualifiedTemplateName();
5099     AddNestedNameSpecifier(QualT->getQualifier(), Record);
5100     Record.push_back(QualT->hasTemplateKeyword());
5101     AddDeclRef(QualT->getTemplateDecl(), Record);
5102     break;
5103   }
5104 
5105   case TemplateName::DependentTemplate: {
5106     DependentTemplateName *DepT = Name.getAsDependentTemplateName();
5107     AddNestedNameSpecifier(DepT->getQualifier(), Record);
5108     Record.push_back(DepT->isIdentifier());
5109     if (DepT->isIdentifier())
5110       AddIdentifierRef(DepT->getIdentifier(), Record);
5111     else
5112       Record.push_back(DepT->getOperator());
5113     break;
5114   }
5115 
5116   case TemplateName::SubstTemplateTemplateParm: {
5117     SubstTemplateTemplateParmStorage *subst
5118       = Name.getAsSubstTemplateTemplateParm();
5119     AddDeclRef(subst->getParameter(), Record);
5120     AddTemplateName(subst->getReplacement(), Record);
5121     break;
5122   }
5123 
5124   case TemplateName::SubstTemplateTemplateParmPack: {
5125     SubstTemplateTemplateParmPackStorage *SubstPack
5126       = Name.getAsSubstTemplateTemplateParmPack();
5127     AddDeclRef(SubstPack->getParameterPack(), Record);
5128     AddTemplateArgument(SubstPack->getArgumentPack(), Record);
5129     break;
5130   }
5131   }
5132 }
5133 
5134 void ASTWriter::AddTemplateArgument(const TemplateArgument &Arg,
5135                                     RecordDataImpl &Record) {
5136   Record.push_back(Arg.getKind());
5137   switch (Arg.getKind()) {
5138   case TemplateArgument::Null:
5139     break;
5140   case TemplateArgument::Type:
5141     AddTypeRef(Arg.getAsType(), Record);
5142     break;
5143   case TemplateArgument::Declaration:
5144     AddDeclRef(Arg.getAsDecl(), Record);
5145     Record.push_back(Arg.isDeclForReferenceParam());
5146     break;
5147   case TemplateArgument::NullPtr:
5148     AddTypeRef(Arg.getNullPtrType(), Record);
5149     break;
5150   case TemplateArgument::Integral:
5151     AddAPSInt(Arg.getAsIntegral(), Record);
5152     AddTypeRef(Arg.getIntegralType(), Record);
5153     break;
5154   case TemplateArgument::Template:
5155     AddTemplateName(Arg.getAsTemplateOrTemplatePattern(), Record);
5156     break;
5157   case TemplateArgument::TemplateExpansion:
5158     AddTemplateName(Arg.getAsTemplateOrTemplatePattern(), Record);
5159     if (Optional<unsigned> NumExpansions = Arg.getNumTemplateExpansions())
5160       Record.push_back(*NumExpansions + 1);
5161     else
5162       Record.push_back(0);
5163     break;
5164   case TemplateArgument::Expression:
5165     AddStmt(Arg.getAsExpr());
5166     break;
5167   case TemplateArgument::Pack:
5168     Record.push_back(Arg.pack_size());
5169     for (TemplateArgument::pack_iterator I=Arg.pack_begin(), E=Arg.pack_end();
5170            I != E; ++I)
5171       AddTemplateArgument(*I, Record);
5172     break;
5173   }
5174 }
5175 
5176 void
5177 ASTWriter::AddTemplateParameterList(const TemplateParameterList *TemplateParams,
5178                                     RecordDataImpl &Record) {
5179   assert(TemplateParams && "No TemplateParams!");
5180   AddSourceLocation(TemplateParams->getTemplateLoc(), Record);
5181   AddSourceLocation(TemplateParams->getLAngleLoc(), Record);
5182   AddSourceLocation(TemplateParams->getRAngleLoc(), Record);
5183   Record.push_back(TemplateParams->size());
5184   for (TemplateParameterList::const_iterator
5185          P = TemplateParams->begin(), PEnd = TemplateParams->end();
5186          P != PEnd; ++P)
5187     AddDeclRef(*P, Record);
5188 }
5189 
5190 /// \brief Emit a template argument list.
5191 void
5192 ASTWriter::AddTemplateArgumentList(const TemplateArgumentList *TemplateArgs,
5193                                    RecordDataImpl &Record) {
5194   assert(TemplateArgs && "No TemplateArgs!");
5195   Record.push_back(TemplateArgs->size());
5196   for (int i=0, e = TemplateArgs->size(); i != e; ++i)
5197     AddTemplateArgument(TemplateArgs->get(i), Record);
5198 }
5199 
5200 void
5201 ASTWriter::AddASTTemplateArgumentListInfo
5202 (const ASTTemplateArgumentListInfo *ASTTemplArgList, RecordDataImpl &Record) {
5203   assert(ASTTemplArgList && "No ASTTemplArgList!");
5204   AddSourceLocation(ASTTemplArgList->LAngleLoc, Record);
5205   AddSourceLocation(ASTTemplArgList->RAngleLoc, Record);
5206   Record.push_back(ASTTemplArgList->NumTemplateArgs);
5207   const TemplateArgumentLoc *TemplArgs = ASTTemplArgList->getTemplateArgs();
5208   for (int i=0, e = ASTTemplArgList->NumTemplateArgs; i != e; ++i)
5209     AddTemplateArgumentLoc(TemplArgs[i], Record);
5210 }
5211 
5212 void
5213 ASTWriter::AddUnresolvedSet(const ASTUnresolvedSet &Set, RecordDataImpl &Record) {
5214   Record.push_back(Set.size());
5215   for (ASTUnresolvedSet::const_iterator
5216          I = Set.begin(), E = Set.end(); I != E; ++I) {
5217     AddDeclRef(I.getDecl(), Record);
5218     Record.push_back(I.getAccess());
5219   }
5220 }
5221 
5222 void ASTWriter::AddCXXBaseSpecifier(const CXXBaseSpecifier &Base,
5223                                     RecordDataImpl &Record) {
5224   Record.push_back(Base.isVirtual());
5225   Record.push_back(Base.isBaseOfClass());
5226   Record.push_back(Base.getAccessSpecifierAsWritten());
5227   Record.push_back(Base.getInheritConstructors());
5228   AddTypeSourceInfo(Base.getTypeSourceInfo(), Record);
5229   AddSourceRange(Base.getSourceRange(), Record);
5230   AddSourceLocation(Base.isPackExpansion()? Base.getEllipsisLoc()
5231                                           : SourceLocation(),
5232                     Record);
5233 }
5234 
5235 void ASTWriter::FlushCXXBaseSpecifiers() {
5236   RecordData Record;
5237   for (unsigned I = 0, N = CXXBaseSpecifiersToWrite.size(); I != N; ++I) {
5238     Record.clear();
5239 
5240     // Record the offset of this base-specifier set.
5241     unsigned Index = CXXBaseSpecifiersToWrite[I].ID - 1;
5242     if (Index == CXXBaseSpecifiersOffsets.size())
5243       CXXBaseSpecifiersOffsets.push_back(Stream.GetCurrentBitNo());
5244     else {
5245       if (Index > CXXBaseSpecifiersOffsets.size())
5246         CXXBaseSpecifiersOffsets.resize(Index + 1);
5247       CXXBaseSpecifiersOffsets[Index] = Stream.GetCurrentBitNo();
5248     }
5249 
5250     const CXXBaseSpecifier *B = CXXBaseSpecifiersToWrite[I].Bases,
5251                         *BEnd = CXXBaseSpecifiersToWrite[I].BasesEnd;
5252     Record.push_back(BEnd - B);
5253     for (; B != BEnd; ++B)
5254       AddCXXBaseSpecifier(*B, Record);
5255     Stream.EmitRecord(serialization::DECL_CXX_BASE_SPECIFIERS, Record);
5256 
5257     // Flush any expressions that were written as part of the base specifiers.
5258     FlushStmts();
5259   }
5260 
5261   CXXBaseSpecifiersToWrite.clear();
5262 }
5263 
5264 void ASTWriter::AddCXXCtorInitializers(
5265                              const CXXCtorInitializer * const *CtorInitializers,
5266                              unsigned NumCtorInitializers,
5267                              RecordDataImpl &Record) {
5268   Record.push_back(NumCtorInitializers);
5269   for (unsigned i=0; i != NumCtorInitializers; ++i) {
5270     const CXXCtorInitializer *Init = CtorInitializers[i];
5271 
5272     if (Init->isBaseInitializer()) {
5273       Record.push_back(CTOR_INITIALIZER_BASE);
5274       AddTypeSourceInfo(Init->getTypeSourceInfo(), Record);
5275       Record.push_back(Init->isBaseVirtual());
5276     } else if (Init->isDelegatingInitializer()) {
5277       Record.push_back(CTOR_INITIALIZER_DELEGATING);
5278       AddTypeSourceInfo(Init->getTypeSourceInfo(), Record);
5279     } else if (Init->isMemberInitializer()){
5280       Record.push_back(CTOR_INITIALIZER_MEMBER);
5281       AddDeclRef(Init->getMember(), Record);
5282     } else {
5283       Record.push_back(CTOR_INITIALIZER_INDIRECT_MEMBER);
5284       AddDeclRef(Init->getIndirectMember(), Record);
5285     }
5286 
5287     AddSourceLocation(Init->getMemberLocation(), Record);
5288     AddStmt(Init->getInit());
5289     AddSourceLocation(Init->getLParenLoc(), Record);
5290     AddSourceLocation(Init->getRParenLoc(), Record);
5291     Record.push_back(Init->isWritten());
5292     if (Init->isWritten()) {
5293       Record.push_back(Init->getSourceOrder());
5294     } else {
5295       Record.push_back(Init->getNumArrayIndices());
5296       for (unsigned i=0, e=Init->getNumArrayIndices(); i != e; ++i)
5297         AddDeclRef(Init->getArrayIndex(i), Record);
5298     }
5299   }
5300 }
5301 
5302 void ASTWriter::AddCXXDefinitionData(const CXXRecordDecl *D, RecordDataImpl &Record) {
5303   assert(D->DefinitionData);
5304   struct CXXRecordDecl::DefinitionData &Data = *D->DefinitionData;
5305   Record.push_back(Data.IsLambda);
5306   Record.push_back(Data.UserDeclaredConstructor);
5307   Record.push_back(Data.UserDeclaredSpecialMembers);
5308   Record.push_back(Data.Aggregate);
5309   Record.push_back(Data.PlainOldData);
5310   Record.push_back(Data.Empty);
5311   Record.push_back(Data.Polymorphic);
5312   Record.push_back(Data.Abstract);
5313   Record.push_back(Data.IsStandardLayout);
5314   Record.push_back(Data.HasNoNonEmptyBases);
5315   Record.push_back(Data.HasPrivateFields);
5316   Record.push_back(Data.HasProtectedFields);
5317   Record.push_back(Data.HasPublicFields);
5318   Record.push_back(Data.HasMutableFields);
5319   Record.push_back(Data.HasVariantMembers);
5320   Record.push_back(Data.HasOnlyCMembers);
5321   Record.push_back(Data.HasInClassInitializer);
5322   Record.push_back(Data.HasUninitializedReferenceMember);
5323   Record.push_back(Data.NeedOverloadResolutionForMoveConstructor);
5324   Record.push_back(Data.NeedOverloadResolutionForMoveAssignment);
5325   Record.push_back(Data.NeedOverloadResolutionForDestructor);
5326   Record.push_back(Data.DefaultedMoveConstructorIsDeleted);
5327   Record.push_back(Data.DefaultedMoveAssignmentIsDeleted);
5328   Record.push_back(Data.DefaultedDestructorIsDeleted);
5329   Record.push_back(Data.HasTrivialSpecialMembers);
5330   Record.push_back(Data.DeclaredNonTrivialSpecialMembers);
5331   Record.push_back(Data.HasIrrelevantDestructor);
5332   Record.push_back(Data.HasConstexprNonCopyMoveConstructor);
5333   Record.push_back(Data.DefaultedDefaultConstructorIsConstexpr);
5334   Record.push_back(Data.HasConstexprDefaultConstructor);
5335   Record.push_back(Data.HasNonLiteralTypeFieldsOrBases);
5336   Record.push_back(Data.ComputedVisibleConversions);
5337   Record.push_back(Data.UserProvidedDefaultConstructor);
5338   Record.push_back(Data.DeclaredSpecialMembers);
5339   Record.push_back(Data.ImplicitCopyConstructorHasConstParam);
5340   Record.push_back(Data.ImplicitCopyAssignmentHasConstParam);
5341   Record.push_back(Data.HasDeclaredCopyConstructorWithConstParam);
5342   Record.push_back(Data.HasDeclaredCopyAssignmentWithConstParam);
5343   // IsLambda bit is already saved.
5344 
5345   Record.push_back(Data.NumBases);
5346   if (Data.NumBases > 0)
5347     AddCXXBaseSpecifiersRef(Data.getBases(), Data.getBases() + Data.NumBases,
5348                             Record);
5349 
5350   // FIXME: Make VBases lazily computed when needed to avoid storing them.
5351   Record.push_back(Data.NumVBases);
5352   if (Data.NumVBases > 0)
5353     AddCXXBaseSpecifiersRef(Data.getVBases(), Data.getVBases() + Data.NumVBases,
5354                             Record);
5355 
5356   AddUnresolvedSet(Data.Conversions.get(*Context), Record);
5357   AddUnresolvedSet(Data.VisibleConversions.get(*Context), Record);
5358   // Data.Definition is the owning decl, no need to write it.
5359   AddDeclRef(D->getFirstFriend(), Record);
5360 
5361   // Add lambda-specific data.
5362   if (Data.IsLambda) {
5363     CXXRecordDecl::LambdaDefinitionData &Lambda = D->getLambdaData();
5364     Record.push_back(Lambda.Dependent);
5365     Record.push_back(Lambda.IsGenericLambda);
5366     Record.push_back(Lambda.CaptureDefault);
5367     Record.push_back(Lambda.NumCaptures);
5368     Record.push_back(Lambda.NumExplicitCaptures);
5369     Record.push_back(Lambda.ManglingNumber);
5370     AddDeclRef(Lambda.ContextDecl, Record);
5371     AddTypeSourceInfo(Lambda.MethodTyInfo, Record);
5372     for (unsigned I = 0, N = Lambda.NumCaptures; I != N; ++I) {
5373       LambdaExpr::Capture &Capture = Lambda.Captures[I];
5374       AddSourceLocation(Capture.getLocation(), Record);
5375       Record.push_back(Capture.isImplicit());
5376       Record.push_back(Capture.getCaptureKind());
5377       switch (Capture.getCaptureKind()) {
5378       case LCK_This:
5379         break;
5380       case LCK_ByCopy:
5381       case LCK_ByRef:
5382         VarDecl *Var =
5383             Capture.capturesVariable() ? Capture.getCapturedVar() : 0;
5384         AddDeclRef(Var, Record);
5385         AddSourceLocation(Capture.isPackExpansion() ? Capture.getEllipsisLoc()
5386                                                     : SourceLocation(),
5387                           Record);
5388         break;
5389       }
5390     }
5391   }
5392 }
5393 
5394 void ASTWriter::ReaderInitialized(ASTReader *Reader) {
5395   assert(Reader && "Cannot remove chain");
5396   assert((!Chain || Chain == Reader) && "Cannot replace chain");
5397   assert(FirstDeclID == NextDeclID &&
5398          FirstTypeID == NextTypeID &&
5399          FirstIdentID == NextIdentID &&
5400          FirstMacroID == NextMacroID &&
5401          FirstSubmoduleID == NextSubmoduleID &&
5402          FirstSelectorID == NextSelectorID &&
5403          "Setting chain after writing has started.");
5404 
5405   Chain = Reader;
5406 
5407   FirstDeclID = NUM_PREDEF_DECL_IDS + Chain->getTotalNumDecls();
5408   FirstTypeID = NUM_PREDEF_TYPE_IDS + Chain->getTotalNumTypes();
5409   FirstIdentID = NUM_PREDEF_IDENT_IDS + Chain->getTotalNumIdentifiers();
5410   FirstMacroID = NUM_PREDEF_MACRO_IDS + Chain->getTotalNumMacros();
5411   FirstSubmoduleID = NUM_PREDEF_SUBMODULE_IDS + Chain->getTotalNumSubmodules();
5412   FirstSelectorID = NUM_PREDEF_SELECTOR_IDS + Chain->getTotalNumSelectors();
5413   NextDeclID = FirstDeclID;
5414   NextTypeID = FirstTypeID;
5415   NextIdentID = FirstIdentID;
5416   NextMacroID = FirstMacroID;
5417   NextSelectorID = FirstSelectorID;
5418   NextSubmoduleID = FirstSubmoduleID;
5419 }
5420 
5421 void ASTWriter::IdentifierRead(IdentID ID, IdentifierInfo *II) {
5422   // Always keep the highest ID. See \p TypeRead() for more information.
5423   IdentID &StoredID = IdentifierIDs[II];
5424   if (ID > StoredID)
5425     StoredID = ID;
5426 }
5427 
5428 void ASTWriter::MacroRead(serialization::MacroID ID, MacroInfo *MI) {
5429   // Always keep the highest ID. See \p TypeRead() for more information.
5430   MacroID &StoredID = MacroIDs[MI];
5431   if (ID > StoredID)
5432     StoredID = ID;
5433 }
5434 
5435 void ASTWriter::TypeRead(TypeIdx Idx, QualType T) {
5436   // Always take the highest-numbered type index. This copes with an interesting
5437   // case for chained AST writing where we schedule writing the type and then,
5438   // later, deserialize the type from another AST. In this case, we want to
5439   // keep the higher-numbered entry so that we can properly write it out to
5440   // the AST file.
5441   TypeIdx &StoredIdx = TypeIdxs[T];
5442   if (Idx.getIndex() >= StoredIdx.getIndex())
5443     StoredIdx = Idx;
5444 }
5445 
5446 void ASTWriter::SelectorRead(SelectorID ID, Selector S) {
5447   // Always keep the highest ID. See \p TypeRead() for more information.
5448   SelectorID &StoredID = SelectorIDs[S];
5449   if (ID > StoredID)
5450     StoredID = ID;
5451 }
5452 
5453 void ASTWriter::MacroDefinitionRead(serialization::PreprocessedEntityID ID,
5454                                     MacroDefinition *MD) {
5455   assert(MacroDefinitions.find(MD) == MacroDefinitions.end());
5456   MacroDefinitions[MD] = ID;
5457 }
5458 
5459 void ASTWriter::ModuleRead(serialization::SubmoduleID ID, Module *Mod) {
5460   assert(SubmoduleIDs.find(Mod) == SubmoduleIDs.end());
5461   SubmoduleIDs[Mod] = ID;
5462 }
5463 
5464 void ASTWriter::CompletedTagDefinition(const TagDecl *D) {
5465   assert(D->isCompleteDefinition());
5466   assert(!WritingAST && "Already writing the AST!");
5467   if (const CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(D)) {
5468     // We are interested when a PCH decl is modified.
5469     if (RD->isFromASTFile()) {
5470       // A forward reference was mutated into a definition. Rewrite it.
5471       // FIXME: This happens during template instantiation, should we
5472       // have created a new definition decl instead ?
5473       assert(isTemplateInstantiation(RD->getTemplateSpecializationKind()) &&
5474              "completed a tag from another module but not by instantiation?");
5475       DeclUpdates[RD].push_back(
5476           DeclUpdate(UPD_CXX_INSTANTIATED_CLASS_DEFINITION));
5477     }
5478   }
5479 }
5480 
5481 void ASTWriter::AddedVisibleDecl(const DeclContext *DC, const Decl *D) {
5482   assert(!WritingAST && "Already writing the AST!");
5483 
5484   // TU and namespaces are handled elsewhere.
5485   if (isa<TranslationUnitDecl>(DC) || isa<NamespaceDecl>(DC))
5486     return;
5487 
5488   if (!(!D->isFromASTFile() && cast<Decl>(DC)->isFromASTFile()))
5489     return; // Not a source decl added to a DeclContext from PCH.
5490 
5491   assert(!getDefinitiveDeclContext(DC) && "DeclContext not definitive!");
5492   AddUpdatedDeclContext(DC);
5493   UpdatingVisibleDecls.push_back(D);
5494 }
5495 
5496 void ASTWriter::AddedCXXImplicitMember(const CXXRecordDecl *RD, const Decl *D) {
5497   assert(!WritingAST && "Already writing the AST!");
5498   assert(D->isImplicit());
5499   if (!(!D->isFromASTFile() && RD->isFromASTFile()))
5500     return; // Not a source member added to a class from PCH.
5501   if (!isa<CXXMethodDecl>(D))
5502     return; // We are interested in lazily declared implicit methods.
5503 
5504   // A decl coming from PCH was modified.
5505   assert(RD->isCompleteDefinition());
5506   DeclUpdates[RD].push_back(DeclUpdate(UPD_CXX_ADDED_IMPLICIT_MEMBER, D));
5507 }
5508 
5509 void ASTWriter::AddedCXXTemplateSpecialization(const ClassTemplateDecl *TD,
5510                                      const ClassTemplateSpecializationDecl *D) {
5511   // The specializations set is kept in the canonical template.
5512   assert(!WritingAST && "Already writing the AST!");
5513   TD = TD->getCanonicalDecl();
5514   if (!(!D->isFromASTFile() && TD->isFromASTFile()))
5515     return; // Not a source specialization added to a template from PCH.
5516 
5517   DeclUpdates[TD].push_back(DeclUpdate(UPD_CXX_ADDED_TEMPLATE_SPECIALIZATION,
5518                                        D));
5519 }
5520 
5521 void ASTWriter::AddedCXXTemplateSpecialization(
5522     const VarTemplateDecl *TD, const VarTemplateSpecializationDecl *D) {
5523   // The specializations set is kept in the canonical template.
5524   assert(!WritingAST && "Already writing the AST!");
5525   TD = TD->getCanonicalDecl();
5526   if (!(!D->isFromASTFile() && TD->isFromASTFile()))
5527     return; // Not a source specialization added to a template from PCH.
5528 
5529   DeclUpdates[TD].push_back(DeclUpdate(UPD_CXX_ADDED_TEMPLATE_SPECIALIZATION,
5530                                        D));
5531 }
5532 
5533 void ASTWriter::AddedCXXTemplateSpecialization(const FunctionTemplateDecl *TD,
5534                                                const FunctionDecl *D) {
5535   // The specializations set is kept in the canonical template.
5536   assert(!WritingAST && "Already writing the AST!");
5537   TD = TD->getCanonicalDecl();
5538   if (!(!D->isFromASTFile() && TD->isFromASTFile()))
5539     return; // Not a source specialization added to a template from PCH.
5540 
5541   DeclUpdates[TD].push_back(DeclUpdate(UPD_CXX_ADDED_TEMPLATE_SPECIALIZATION,
5542                                        D));
5543 }
5544 
5545 void ASTWriter::ResolvedExceptionSpec(const FunctionDecl *FD) {
5546   assert(!WritingAST && "Already writing the AST!");
5547   FD = FD->getCanonicalDecl();
5548   if (!FD->isFromASTFile())
5549     return; // Not a function declared in PCH and defined outside.
5550 
5551   DeclUpdates[FD].push_back(UPD_CXX_RESOLVED_EXCEPTION_SPEC);
5552 }
5553 
5554 void ASTWriter::DeducedReturnType(const FunctionDecl *FD, QualType ReturnType) {
5555   assert(!WritingAST && "Already writing the AST!");
5556   FD = FD->getCanonicalDecl();
5557   if (!FD->isFromASTFile())
5558     return; // Not a function declared in PCH and defined outside.
5559 
5560   DeclUpdates[FD].push_back(DeclUpdate(UPD_CXX_DEDUCED_RETURN_TYPE, ReturnType));
5561 }
5562 
5563 void ASTWriter::CompletedImplicitDefinition(const FunctionDecl *D) {
5564   assert(!WritingAST && "Already writing the AST!");
5565   if (!D->isFromASTFile())
5566     return; // Declaration not imported from PCH.
5567 
5568   // Implicit decl from a PCH was defined.
5569   // FIXME: Should implicit definition be a separate FunctionDecl?
5570   RewriteDecl(D);
5571 }
5572 
5573 void ASTWriter::FunctionDefinitionInstantiated(const FunctionDecl *D) {
5574   assert(!WritingAST && "Already writing the AST!");
5575   if (!D->isFromASTFile())
5576     return;
5577 
5578   // Since the actual instantiation is delayed, this really means that we need
5579   // to update the instantiation location.
5580   DeclUpdates[D].push_back(
5581       DeclUpdate(UPD_CXX_INSTANTIATED_FUNCTION_DEFINITION));
5582 }
5583 
5584 void ASTWriter::StaticDataMemberInstantiated(const VarDecl *D) {
5585   assert(!WritingAST && "Already writing the AST!");
5586   if (!D->isFromASTFile())
5587     return;
5588 
5589   // Since the actual instantiation is delayed, this really means that we need
5590   // to update the instantiation location.
5591   DeclUpdates[D].push_back(
5592       DeclUpdate(UPD_CXX_INSTANTIATED_STATIC_DATA_MEMBER,
5593        D->getMemberSpecializationInfo()->getPointOfInstantiation()));
5594 }
5595 
5596 void ASTWriter::AddedObjCCategoryToInterface(const ObjCCategoryDecl *CatD,
5597                                              const ObjCInterfaceDecl *IFD) {
5598   assert(!WritingAST && "Already writing the AST!");
5599   if (!IFD->isFromASTFile())
5600     return; // Declaration not imported from PCH.
5601 
5602   assert(IFD->getDefinition() && "Category on a class without a definition?");
5603   ObjCClassesWithCategories.insert(
5604     const_cast<ObjCInterfaceDecl *>(IFD->getDefinition()));
5605 }
5606 
5607 
5608 void ASTWriter::AddedObjCPropertyInClassExtension(const ObjCPropertyDecl *Prop,
5609                                           const ObjCPropertyDecl *OrigProp,
5610                                           const ObjCCategoryDecl *ClassExt) {
5611   const ObjCInterfaceDecl *D = ClassExt->getClassInterface();
5612   if (!D)
5613     return;
5614 
5615   assert(!WritingAST && "Already writing the AST!");
5616   if (!D->isFromASTFile())
5617     return; // Declaration not imported from PCH.
5618 
5619   RewriteDecl(D);
5620 }
5621 
5622 void ASTWriter::DeclarationMarkedUsed(const Decl *D) {
5623   assert(!WritingAST && "Already writing the AST!");
5624   if (!D->isFromASTFile())
5625     return;
5626 
5627   DeclUpdates[D].push_back(DeclUpdate(UPD_DECL_MARKED_USED));
5628 }
5629