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/DiagnosticOptions.h"
27 #include "clang/Basic/FileManager.h"
28 #include "clang/Basic/FileSystemStatCache.h"
29 #include "clang/Basic/SourceManager.h"
30 #include "clang/Basic/SourceManagerInternals.h"
31 #include "clang/Basic/TargetInfo.h"
32 #include "clang/Basic/TargetOptions.h"
33 #include "clang/Basic/Version.h"
34 #include "clang/Basic/VersionTuple.h"
35 #include "clang/Lex/HeaderSearch.h"
36 #include "clang/Lex/HeaderSearchOptions.h"
37 #include "clang/Lex/MacroInfo.h"
38 #include "clang/Lex/PreprocessingRecord.h"
39 #include "clang/Lex/Preprocessor.h"
40 #include "clang/Lex/PreprocessorOptions.h"
41 #include "clang/Sema/IdentifierResolver.h"
42 #include "clang/Sema/Sema.h"
43 #include "clang/Serialization/ASTReader.h"
44 #include "llvm/ADT/APFloat.h"
45 #include "llvm/ADT/APInt.h"
46 #include "llvm/ADT/Hashing.h"
47 #include "llvm/ADT/StringExtras.h"
48 #include "llvm/Bitcode/BitstreamWriter.h"
49 #include "llvm/Support/EndianStream.h"
50 #include "llvm/Support/FileSystem.h"
51 #include "llvm/Support/MemoryBuffer.h"
52 #include "llvm/Support/OnDiskHashTable.h"
53 #include "llvm/Support/Path.h"
54 #include "llvm/Support/Process.h"
55 #include <algorithm>
56 #include <cstdio>
57 #include <string.h>
58 #include <utility>
59 using namespace clang;
60 using namespace clang::serialization;
61 
62 template <typename T, typename Allocator>
63 static StringRef data(const std::vector<T, Allocator> &v) {
64   if (v.empty()) return StringRef();
65   return StringRef(reinterpret_cast<const char*>(&v[0]),
66                          sizeof(T) * v.size());
67 }
68 
69 template <typename T>
70 static StringRef data(const SmallVectorImpl<T> &v) {
71   return StringRef(reinterpret_cast<const char*>(v.data()),
72                          sizeof(T) * v.size());
73 }
74 
75 //===----------------------------------------------------------------------===//
76 // Type serialization
77 //===----------------------------------------------------------------------===//
78 
79 namespace {
80   class ASTTypeWriter {
81     ASTWriter &Writer;
82     ASTWriter::RecordDataImpl &Record;
83 
84   public:
85     /// \brief Type code that corresponds to the record generated.
86     TypeCode Code;
87     /// \brief Abbreviation to use for the record, if any.
88     unsigned AbbrevToUse;
89 
90     ASTTypeWriter(ASTWriter &Writer, ASTWriter::RecordDataImpl &Record)
91       : Writer(Writer), Record(Record), Code(TYPE_EXT_QUAL) { }
92 
93     void VisitArrayType(const ArrayType *T);
94     void VisitFunctionType(const FunctionType *T);
95     void VisitTagType(const TagType *T);
96 
97 #define TYPE(Class, Base) void Visit##Class##Type(const Class##Type *T);
98 #define ABSTRACT_TYPE(Class, Base)
99 #include "clang/AST/TypeNodes.def"
100   };
101 }
102 
103 void ASTTypeWriter::VisitBuiltinType(const BuiltinType *T) {
104   llvm_unreachable("Built-in types are never serialized");
105 }
106 
107 void ASTTypeWriter::VisitComplexType(const ComplexType *T) {
108   Writer.AddTypeRef(T->getElementType(), Record);
109   Code = TYPE_COMPLEX;
110 }
111 
112 void ASTTypeWriter::VisitPointerType(const PointerType *T) {
113   Writer.AddTypeRef(T->getPointeeType(), Record);
114   Code = TYPE_POINTER;
115 }
116 
117 void ASTTypeWriter::VisitDecayedType(const DecayedType *T) {
118   Writer.AddTypeRef(T->getOriginalType(), Record);
119   Code = TYPE_DECAYED;
120 }
121 
122 void ASTTypeWriter::VisitAdjustedType(const AdjustedType *T) {
123   Writer.AddTypeRef(T->getOriginalType(), Record);
124   Writer.AddTypeRef(T->getAdjustedType(), Record);
125   Code = TYPE_ADJUSTED;
126 }
127 
128 void ASTTypeWriter::VisitBlockPointerType(const BlockPointerType *T) {
129   Writer.AddTypeRef(T->getPointeeType(), Record);
130   Code = TYPE_BLOCK_POINTER;
131 }
132 
133 void ASTTypeWriter::VisitLValueReferenceType(const LValueReferenceType *T) {
134   Writer.AddTypeRef(T->getPointeeTypeAsWritten(), Record);
135   Record.push_back(T->isSpelledAsLValue());
136   Code = TYPE_LVALUE_REFERENCE;
137 }
138 
139 void ASTTypeWriter::VisitRValueReferenceType(const RValueReferenceType *T) {
140   Writer.AddTypeRef(T->getPointeeTypeAsWritten(), Record);
141   Code = TYPE_RVALUE_REFERENCE;
142 }
143 
144 void ASTTypeWriter::VisitMemberPointerType(const MemberPointerType *T) {
145   Writer.AddTypeRef(T->getPointeeType(), Record);
146   Writer.AddTypeRef(QualType(T->getClass(), 0), Record);
147   Code = TYPE_MEMBER_POINTER;
148 }
149 
150 void ASTTypeWriter::VisitArrayType(const ArrayType *T) {
151   Writer.AddTypeRef(T->getElementType(), Record);
152   Record.push_back(T->getSizeModifier()); // FIXME: stable values
153   Record.push_back(T->getIndexTypeCVRQualifiers()); // FIXME: stable values
154 }
155 
156 void ASTTypeWriter::VisitConstantArrayType(const ConstantArrayType *T) {
157   VisitArrayType(T);
158   Writer.AddAPInt(T->getSize(), Record);
159   Code = TYPE_CONSTANT_ARRAY;
160 }
161 
162 void ASTTypeWriter::VisitIncompleteArrayType(const IncompleteArrayType *T) {
163   VisitArrayType(T);
164   Code = TYPE_INCOMPLETE_ARRAY;
165 }
166 
167 void ASTTypeWriter::VisitVariableArrayType(const VariableArrayType *T) {
168   VisitArrayType(T);
169   Writer.AddSourceLocation(T->getLBracketLoc(), Record);
170   Writer.AddSourceLocation(T->getRBracketLoc(), Record);
171   Writer.AddStmt(T->getSizeExpr());
172   Code = TYPE_VARIABLE_ARRAY;
173 }
174 
175 void ASTTypeWriter::VisitVectorType(const VectorType *T) {
176   Writer.AddTypeRef(T->getElementType(), Record);
177   Record.push_back(T->getNumElements());
178   Record.push_back(T->getVectorKind());
179   Code = TYPE_VECTOR;
180 }
181 
182 void ASTTypeWriter::VisitExtVectorType(const ExtVectorType *T) {
183   VisitVectorType(T);
184   Code = TYPE_EXT_VECTOR;
185 }
186 
187 void ASTTypeWriter::VisitFunctionType(const FunctionType *T) {
188   Writer.AddTypeRef(T->getReturnType(), Record);
189   FunctionType::ExtInfo C = T->getExtInfo();
190   Record.push_back(C.getNoReturn());
191   Record.push_back(C.getHasRegParm());
192   Record.push_back(C.getRegParm());
193   // FIXME: need to stabilize encoding of calling convention...
194   Record.push_back(C.getCC());
195   Record.push_back(C.getProducesResult());
196 
197   if (C.getHasRegParm() || C.getRegParm() || C.getProducesResult())
198     AbbrevToUse = 0;
199 }
200 
201 void ASTTypeWriter::VisitFunctionNoProtoType(const FunctionNoProtoType *T) {
202   VisitFunctionType(T);
203   Code = TYPE_FUNCTION_NO_PROTO;
204 }
205 
206 static void addExceptionSpec(ASTWriter &Writer, const FunctionProtoType *T,
207                              ASTWriter::RecordDataImpl &Record) {
208   Record.push_back(T->getExceptionSpecType());
209   if (T->getExceptionSpecType() == EST_Dynamic) {
210     Record.push_back(T->getNumExceptions());
211     for (unsigned I = 0, N = T->getNumExceptions(); I != N; ++I)
212       Writer.AddTypeRef(T->getExceptionType(I), Record);
213   } else if (T->getExceptionSpecType() == EST_ComputedNoexcept) {
214     Writer.AddStmt(T->getNoexceptExpr());
215   } else if (T->getExceptionSpecType() == EST_Uninstantiated) {
216     Writer.AddDeclRef(T->getExceptionSpecDecl(), Record);
217     Writer.AddDeclRef(T->getExceptionSpecTemplate(), Record);
218   } else if (T->getExceptionSpecType() == EST_Unevaluated) {
219     Writer.AddDeclRef(T->getExceptionSpecDecl(), Record);
220   }
221 }
222 
223 void ASTTypeWriter::VisitFunctionProtoType(const FunctionProtoType *T) {
224   VisitFunctionType(T);
225 
226   Record.push_back(T->isVariadic());
227   Record.push_back(T->hasTrailingReturn());
228   Record.push_back(T->getTypeQuals());
229   Record.push_back(static_cast<unsigned>(T->getRefQualifier()));
230   addExceptionSpec(Writer, T, Record);
231 
232   Record.push_back(T->getNumParams());
233   for (unsigned I = 0, N = T->getNumParams(); I != N; ++I)
234     Writer.AddTypeRef(T->getParamType(I), Record);
235 
236   if (T->isVariadic() || T->hasTrailingReturn() || T->getTypeQuals() ||
237       T->getRefQualifier() || T->getExceptionSpecType() != EST_None)
238     AbbrevToUse = 0;
239 
240   Code = TYPE_FUNCTION_PROTO;
241 }
242 
243 void ASTTypeWriter::VisitUnresolvedUsingType(const UnresolvedUsingType *T) {
244   Writer.AddDeclRef(T->getDecl(), Record);
245   Code = TYPE_UNRESOLVED_USING;
246 }
247 
248 void ASTTypeWriter::VisitTypedefType(const TypedefType *T) {
249   Writer.AddDeclRef(T->getDecl(), Record);
250   assert(!T->isCanonicalUnqualified() && "Invalid typedef ?");
251   Writer.AddTypeRef(T->getCanonicalTypeInternal(), Record);
252   Code = TYPE_TYPEDEF;
253 }
254 
255 void ASTTypeWriter::VisitTypeOfExprType(const TypeOfExprType *T) {
256   Writer.AddStmt(T->getUnderlyingExpr());
257   Code = TYPE_TYPEOF_EXPR;
258 }
259 
260 void ASTTypeWriter::VisitTypeOfType(const TypeOfType *T) {
261   Writer.AddTypeRef(T->getUnderlyingType(), Record);
262   Code = TYPE_TYPEOF;
263 }
264 
265 void ASTTypeWriter::VisitDecltypeType(const DecltypeType *T) {
266   Writer.AddTypeRef(T->getUnderlyingType(), Record);
267   Writer.AddStmt(T->getUnderlyingExpr());
268   Code = TYPE_DECLTYPE;
269 }
270 
271 void ASTTypeWriter::VisitUnaryTransformType(const UnaryTransformType *T) {
272   Writer.AddTypeRef(T->getBaseType(), Record);
273   Writer.AddTypeRef(T->getUnderlyingType(), Record);
274   Record.push_back(T->getUTTKind());
275   Code = TYPE_UNARY_TRANSFORM;
276 }
277 
278 void ASTTypeWriter::VisitAutoType(const AutoType *T) {
279   Writer.AddTypeRef(T->getDeducedType(), Record);
280   Record.push_back(T->isDecltypeAuto());
281   if (T->getDeducedType().isNull())
282     Record.push_back(T->isDependentType());
283   Code = TYPE_AUTO;
284 }
285 
286 void ASTTypeWriter::VisitTagType(const TagType *T) {
287   Record.push_back(T->isDependentType());
288   Writer.AddDeclRef(T->getDecl()->getCanonicalDecl(), Record);
289   assert(!T->isBeingDefined() &&
290          "Cannot serialize in the middle of a type definition");
291 }
292 
293 void ASTTypeWriter::VisitRecordType(const RecordType *T) {
294   VisitTagType(T);
295   Code = TYPE_RECORD;
296 }
297 
298 void ASTTypeWriter::VisitEnumType(const EnumType *T) {
299   VisitTagType(T);
300   Code = TYPE_ENUM;
301 }
302 
303 void ASTTypeWriter::VisitAttributedType(const AttributedType *T) {
304   Writer.AddTypeRef(T->getModifiedType(), Record);
305   Writer.AddTypeRef(T->getEquivalentType(), Record);
306   Record.push_back(T->getAttrKind());
307   Code = TYPE_ATTRIBUTED;
308 }
309 
310 void
311 ASTTypeWriter::VisitSubstTemplateTypeParmType(
312                                         const SubstTemplateTypeParmType *T) {
313   Writer.AddTypeRef(QualType(T->getReplacedParameter(), 0), Record);
314   Writer.AddTypeRef(T->getReplacementType(), Record);
315   Code = TYPE_SUBST_TEMPLATE_TYPE_PARM;
316 }
317 
318 void
319 ASTTypeWriter::VisitSubstTemplateTypeParmPackType(
320                                       const SubstTemplateTypeParmPackType *T) {
321   Writer.AddTypeRef(QualType(T->getReplacedParameter(), 0), Record);
322   Writer.AddTemplateArgument(T->getArgumentPack(), Record);
323   Code = TYPE_SUBST_TEMPLATE_TYPE_PARM_PACK;
324 }
325 
326 void
327 ASTTypeWriter::VisitTemplateSpecializationType(
328                                        const TemplateSpecializationType *T) {
329   Record.push_back(T->isDependentType());
330   Writer.AddTemplateName(T->getTemplateName(), Record);
331   Record.push_back(T->getNumArgs());
332   for (TemplateSpecializationType::iterator ArgI = T->begin(), ArgE = T->end();
333          ArgI != ArgE; ++ArgI)
334     Writer.AddTemplateArgument(*ArgI, Record);
335   Writer.AddTypeRef(T->isTypeAlias() ? T->getAliasedType() :
336                     T->isCanonicalUnqualified() ? QualType()
337                                                 : T->getCanonicalTypeInternal(),
338                     Record);
339   Code = TYPE_TEMPLATE_SPECIALIZATION;
340 }
341 
342 void
343 ASTTypeWriter::VisitDependentSizedArrayType(const DependentSizedArrayType *T) {
344   VisitArrayType(T);
345   Writer.AddStmt(T->getSizeExpr());
346   Writer.AddSourceRange(T->getBracketsRange(), Record);
347   Code = TYPE_DEPENDENT_SIZED_ARRAY;
348 }
349 
350 void
351 ASTTypeWriter::VisitDependentSizedExtVectorType(
352                                         const DependentSizedExtVectorType *T) {
353   // FIXME: Serialize this type (C++ only)
354   llvm_unreachable("Cannot serialize dependent sized extended vector types");
355 }
356 
357 void
358 ASTTypeWriter::VisitTemplateTypeParmType(const TemplateTypeParmType *T) {
359   Record.push_back(T->getDepth());
360   Record.push_back(T->getIndex());
361   Record.push_back(T->isParameterPack());
362   Writer.AddDeclRef(T->getDecl(), Record);
363   Code = TYPE_TEMPLATE_TYPE_PARM;
364 }
365 
366 void
367 ASTTypeWriter::VisitDependentNameType(const DependentNameType *T) {
368   Record.push_back(T->getKeyword());
369   Writer.AddNestedNameSpecifier(T->getQualifier(), Record);
370   Writer.AddIdentifierRef(T->getIdentifier(), Record);
371   Writer.AddTypeRef(T->isCanonicalUnqualified() ? QualType()
372                                                 : T->getCanonicalTypeInternal(),
373                     Record);
374   Code = TYPE_DEPENDENT_NAME;
375 }
376 
377 void
378 ASTTypeWriter::VisitDependentTemplateSpecializationType(
379                                 const DependentTemplateSpecializationType *T) {
380   Record.push_back(T->getKeyword());
381   Writer.AddNestedNameSpecifier(T->getQualifier(), Record);
382   Writer.AddIdentifierRef(T->getIdentifier(), Record);
383   Record.push_back(T->getNumArgs());
384   for (DependentTemplateSpecializationType::iterator
385          I = T->begin(), E = T->end(); I != E; ++I)
386     Writer.AddTemplateArgument(*I, Record);
387   Code = TYPE_DEPENDENT_TEMPLATE_SPECIALIZATION;
388 }
389 
390 void ASTTypeWriter::VisitPackExpansionType(const PackExpansionType *T) {
391   Writer.AddTypeRef(T->getPattern(), Record);
392   if (Optional<unsigned> NumExpansions = T->getNumExpansions())
393     Record.push_back(*NumExpansions + 1);
394   else
395     Record.push_back(0);
396   Code = TYPE_PACK_EXPANSION;
397 }
398 
399 void ASTTypeWriter::VisitParenType(const ParenType *T) {
400   Writer.AddTypeRef(T->getInnerType(), Record);
401   Code = TYPE_PAREN;
402 }
403 
404 void ASTTypeWriter::VisitElaboratedType(const ElaboratedType *T) {
405   Record.push_back(T->getKeyword());
406   Writer.AddNestedNameSpecifier(T->getQualifier(), Record);
407   Writer.AddTypeRef(T->getNamedType(), Record);
408   Code = TYPE_ELABORATED;
409 }
410 
411 void ASTTypeWriter::VisitInjectedClassNameType(const InjectedClassNameType *T) {
412   Writer.AddDeclRef(T->getDecl()->getCanonicalDecl(), Record);
413   Writer.AddTypeRef(T->getInjectedSpecializationType(), Record);
414   Code = TYPE_INJECTED_CLASS_NAME;
415 }
416 
417 void ASTTypeWriter::VisitObjCInterfaceType(const ObjCInterfaceType *T) {
418   Writer.AddDeclRef(T->getDecl()->getCanonicalDecl(), Record);
419   Code = TYPE_OBJC_INTERFACE;
420 }
421 
422 void ASTTypeWriter::VisitObjCObjectType(const ObjCObjectType *T) {
423   Writer.AddTypeRef(T->getBaseType(), Record);
424   Record.push_back(T->getNumProtocols());
425   for (const auto *I : T->quals())
426     Writer.AddDeclRef(I, Record);
427   Code = TYPE_OBJC_OBJECT;
428 }
429 
430 void
431 ASTTypeWriter::VisitObjCObjectPointerType(const ObjCObjectPointerType *T) {
432   Writer.AddTypeRef(T->getPointeeType(), Record);
433   Code = TYPE_OBJC_OBJECT_POINTER;
434 }
435 
436 void
437 ASTTypeWriter::VisitAtomicType(const AtomicType *T) {
438   Writer.AddTypeRef(T->getValueType(), Record);
439   Code = TYPE_ATOMIC;
440 }
441 
442 namespace {
443 
444 class TypeLocWriter : public TypeLocVisitor<TypeLocWriter> {
445   ASTWriter &Writer;
446   ASTWriter::RecordDataImpl &Record;
447 
448 public:
449   TypeLocWriter(ASTWriter &Writer, ASTWriter::RecordDataImpl &Record)
450     : Writer(Writer), Record(Record) { }
451 
452 #define ABSTRACT_TYPELOC(CLASS, PARENT)
453 #define TYPELOC(CLASS, PARENT) \
454     void Visit##CLASS##TypeLoc(CLASS##TypeLoc TyLoc);
455 #include "clang/AST/TypeLocNodes.def"
456 
457   void VisitArrayTypeLoc(ArrayTypeLoc TyLoc);
458   void VisitFunctionTypeLoc(FunctionTypeLoc TyLoc);
459 };
460 
461 }
462 
463 void TypeLocWriter::VisitQualifiedTypeLoc(QualifiedTypeLoc TL) {
464   // nothing to do
465 }
466 void TypeLocWriter::VisitBuiltinTypeLoc(BuiltinTypeLoc TL) {
467   Writer.AddSourceLocation(TL.getBuiltinLoc(), Record);
468   if (TL.needsExtraLocalData()) {
469     Record.push_back(TL.getWrittenTypeSpec());
470     Record.push_back(TL.getWrittenSignSpec());
471     Record.push_back(TL.getWrittenWidthSpec());
472     Record.push_back(TL.hasModeAttr());
473   }
474 }
475 void TypeLocWriter::VisitComplexTypeLoc(ComplexTypeLoc TL) {
476   Writer.AddSourceLocation(TL.getNameLoc(), Record);
477 }
478 void TypeLocWriter::VisitPointerTypeLoc(PointerTypeLoc TL) {
479   Writer.AddSourceLocation(TL.getStarLoc(), Record);
480 }
481 void TypeLocWriter::VisitDecayedTypeLoc(DecayedTypeLoc TL) {
482   // nothing to do
483 }
484 void TypeLocWriter::VisitAdjustedTypeLoc(AdjustedTypeLoc TL) {
485   // nothing to do
486 }
487 void TypeLocWriter::VisitBlockPointerTypeLoc(BlockPointerTypeLoc TL) {
488   Writer.AddSourceLocation(TL.getCaretLoc(), Record);
489 }
490 void TypeLocWriter::VisitLValueReferenceTypeLoc(LValueReferenceTypeLoc TL) {
491   Writer.AddSourceLocation(TL.getAmpLoc(), Record);
492 }
493 void TypeLocWriter::VisitRValueReferenceTypeLoc(RValueReferenceTypeLoc TL) {
494   Writer.AddSourceLocation(TL.getAmpAmpLoc(), Record);
495 }
496 void TypeLocWriter::VisitMemberPointerTypeLoc(MemberPointerTypeLoc TL) {
497   Writer.AddSourceLocation(TL.getStarLoc(), Record);
498   Writer.AddTypeSourceInfo(TL.getClassTInfo(), Record);
499 }
500 void TypeLocWriter::VisitArrayTypeLoc(ArrayTypeLoc TL) {
501   Writer.AddSourceLocation(TL.getLBracketLoc(), Record);
502   Writer.AddSourceLocation(TL.getRBracketLoc(), Record);
503   Record.push_back(TL.getSizeExpr() ? 1 : 0);
504   if (TL.getSizeExpr())
505     Writer.AddStmt(TL.getSizeExpr());
506 }
507 void TypeLocWriter::VisitConstantArrayTypeLoc(ConstantArrayTypeLoc TL) {
508   VisitArrayTypeLoc(TL);
509 }
510 void TypeLocWriter::VisitIncompleteArrayTypeLoc(IncompleteArrayTypeLoc TL) {
511   VisitArrayTypeLoc(TL);
512 }
513 void TypeLocWriter::VisitVariableArrayTypeLoc(VariableArrayTypeLoc TL) {
514   VisitArrayTypeLoc(TL);
515 }
516 void TypeLocWriter::VisitDependentSizedArrayTypeLoc(
517                                             DependentSizedArrayTypeLoc TL) {
518   VisitArrayTypeLoc(TL);
519 }
520 void TypeLocWriter::VisitDependentSizedExtVectorTypeLoc(
521                                         DependentSizedExtVectorTypeLoc TL) {
522   Writer.AddSourceLocation(TL.getNameLoc(), Record);
523 }
524 void TypeLocWriter::VisitVectorTypeLoc(VectorTypeLoc TL) {
525   Writer.AddSourceLocation(TL.getNameLoc(), Record);
526 }
527 void TypeLocWriter::VisitExtVectorTypeLoc(ExtVectorTypeLoc TL) {
528   Writer.AddSourceLocation(TL.getNameLoc(), Record);
529 }
530 void TypeLocWriter::VisitFunctionTypeLoc(FunctionTypeLoc TL) {
531   Writer.AddSourceLocation(TL.getLocalRangeBegin(), Record);
532   Writer.AddSourceLocation(TL.getLParenLoc(), Record);
533   Writer.AddSourceLocation(TL.getRParenLoc(), Record);
534   Writer.AddSourceLocation(TL.getLocalRangeEnd(), Record);
535   for (unsigned i = 0, e = TL.getNumParams(); i != e; ++i)
536     Writer.AddDeclRef(TL.getParam(i), Record);
537 }
538 void TypeLocWriter::VisitFunctionProtoTypeLoc(FunctionProtoTypeLoc TL) {
539   VisitFunctionTypeLoc(TL);
540 }
541 void TypeLocWriter::VisitFunctionNoProtoTypeLoc(FunctionNoProtoTypeLoc TL) {
542   VisitFunctionTypeLoc(TL);
543 }
544 void TypeLocWriter::VisitUnresolvedUsingTypeLoc(UnresolvedUsingTypeLoc TL) {
545   Writer.AddSourceLocation(TL.getNameLoc(), Record);
546 }
547 void TypeLocWriter::VisitTypedefTypeLoc(TypedefTypeLoc TL) {
548   Writer.AddSourceLocation(TL.getNameLoc(), Record);
549 }
550 void TypeLocWriter::VisitTypeOfExprTypeLoc(TypeOfExprTypeLoc TL) {
551   Writer.AddSourceLocation(TL.getTypeofLoc(), Record);
552   Writer.AddSourceLocation(TL.getLParenLoc(), Record);
553   Writer.AddSourceLocation(TL.getRParenLoc(), Record);
554 }
555 void TypeLocWriter::VisitTypeOfTypeLoc(TypeOfTypeLoc TL) {
556   Writer.AddSourceLocation(TL.getTypeofLoc(), Record);
557   Writer.AddSourceLocation(TL.getLParenLoc(), Record);
558   Writer.AddSourceLocation(TL.getRParenLoc(), Record);
559   Writer.AddTypeSourceInfo(TL.getUnderlyingTInfo(), Record);
560 }
561 void TypeLocWriter::VisitDecltypeTypeLoc(DecltypeTypeLoc TL) {
562   Writer.AddSourceLocation(TL.getNameLoc(), Record);
563 }
564 void TypeLocWriter::VisitUnaryTransformTypeLoc(UnaryTransformTypeLoc TL) {
565   Writer.AddSourceLocation(TL.getKWLoc(), Record);
566   Writer.AddSourceLocation(TL.getLParenLoc(), Record);
567   Writer.AddSourceLocation(TL.getRParenLoc(), Record);
568   Writer.AddTypeSourceInfo(TL.getUnderlyingTInfo(), Record);
569 }
570 void TypeLocWriter::VisitAutoTypeLoc(AutoTypeLoc TL) {
571   Writer.AddSourceLocation(TL.getNameLoc(), Record);
572 }
573 void TypeLocWriter::VisitRecordTypeLoc(RecordTypeLoc TL) {
574   Writer.AddSourceLocation(TL.getNameLoc(), Record);
575 }
576 void TypeLocWriter::VisitEnumTypeLoc(EnumTypeLoc TL) {
577   Writer.AddSourceLocation(TL.getNameLoc(), Record);
578 }
579 void TypeLocWriter::VisitAttributedTypeLoc(AttributedTypeLoc TL) {
580   Writer.AddSourceLocation(TL.getAttrNameLoc(), Record);
581   if (TL.hasAttrOperand()) {
582     SourceRange range = TL.getAttrOperandParensRange();
583     Writer.AddSourceLocation(range.getBegin(), Record);
584     Writer.AddSourceLocation(range.getEnd(), Record);
585   }
586   if (TL.hasAttrExprOperand()) {
587     Expr *operand = TL.getAttrExprOperand();
588     Record.push_back(operand ? 1 : 0);
589     if (operand) Writer.AddStmt(operand);
590   } else if (TL.hasAttrEnumOperand()) {
591     Writer.AddSourceLocation(TL.getAttrEnumOperandLoc(), Record);
592   }
593 }
594 void TypeLocWriter::VisitTemplateTypeParmTypeLoc(TemplateTypeParmTypeLoc TL) {
595   Writer.AddSourceLocation(TL.getNameLoc(), Record);
596 }
597 void TypeLocWriter::VisitSubstTemplateTypeParmTypeLoc(
598                                             SubstTemplateTypeParmTypeLoc TL) {
599   Writer.AddSourceLocation(TL.getNameLoc(), Record);
600 }
601 void TypeLocWriter::VisitSubstTemplateTypeParmPackTypeLoc(
602                                           SubstTemplateTypeParmPackTypeLoc TL) {
603   Writer.AddSourceLocation(TL.getNameLoc(), Record);
604 }
605 void TypeLocWriter::VisitTemplateSpecializationTypeLoc(
606                                            TemplateSpecializationTypeLoc TL) {
607   Writer.AddSourceLocation(TL.getTemplateKeywordLoc(), Record);
608   Writer.AddSourceLocation(TL.getTemplateNameLoc(), Record);
609   Writer.AddSourceLocation(TL.getLAngleLoc(), Record);
610   Writer.AddSourceLocation(TL.getRAngleLoc(), Record);
611   for (unsigned i = 0, e = TL.getNumArgs(); i != e; ++i)
612     Writer.AddTemplateArgumentLocInfo(TL.getArgLoc(i).getArgument().getKind(),
613                                       TL.getArgLoc(i).getLocInfo(), Record);
614 }
615 void TypeLocWriter::VisitParenTypeLoc(ParenTypeLoc TL) {
616   Writer.AddSourceLocation(TL.getLParenLoc(), Record);
617   Writer.AddSourceLocation(TL.getRParenLoc(), Record);
618 }
619 void TypeLocWriter::VisitElaboratedTypeLoc(ElaboratedTypeLoc TL) {
620   Writer.AddSourceLocation(TL.getElaboratedKeywordLoc(), Record);
621   Writer.AddNestedNameSpecifierLoc(TL.getQualifierLoc(), Record);
622 }
623 void TypeLocWriter::VisitInjectedClassNameTypeLoc(InjectedClassNameTypeLoc TL) {
624   Writer.AddSourceLocation(TL.getNameLoc(), Record);
625 }
626 void TypeLocWriter::VisitDependentNameTypeLoc(DependentNameTypeLoc TL) {
627   Writer.AddSourceLocation(TL.getElaboratedKeywordLoc(), Record);
628   Writer.AddNestedNameSpecifierLoc(TL.getQualifierLoc(), Record);
629   Writer.AddSourceLocation(TL.getNameLoc(), Record);
630 }
631 void TypeLocWriter::VisitDependentTemplateSpecializationTypeLoc(
632        DependentTemplateSpecializationTypeLoc TL) {
633   Writer.AddSourceLocation(TL.getElaboratedKeywordLoc(), Record);
634   Writer.AddNestedNameSpecifierLoc(TL.getQualifierLoc(), Record);
635   Writer.AddSourceLocation(TL.getTemplateKeywordLoc(), Record);
636   Writer.AddSourceLocation(TL.getTemplateNameLoc(), Record);
637   Writer.AddSourceLocation(TL.getLAngleLoc(), Record);
638   Writer.AddSourceLocation(TL.getRAngleLoc(), Record);
639   for (unsigned I = 0, E = TL.getNumArgs(); I != E; ++I)
640     Writer.AddTemplateArgumentLocInfo(TL.getArgLoc(I).getArgument().getKind(),
641                                       TL.getArgLoc(I).getLocInfo(), Record);
642 }
643 void TypeLocWriter::VisitPackExpansionTypeLoc(PackExpansionTypeLoc TL) {
644   Writer.AddSourceLocation(TL.getEllipsisLoc(), Record);
645 }
646 void TypeLocWriter::VisitObjCInterfaceTypeLoc(ObjCInterfaceTypeLoc TL) {
647   Writer.AddSourceLocation(TL.getNameLoc(), Record);
648 }
649 void TypeLocWriter::VisitObjCObjectTypeLoc(ObjCObjectTypeLoc TL) {
650   Record.push_back(TL.hasBaseTypeAsWritten());
651   Writer.AddSourceLocation(TL.getLAngleLoc(), Record);
652   Writer.AddSourceLocation(TL.getRAngleLoc(), Record);
653   for (unsigned i = 0, e = TL.getNumProtocols(); i != e; ++i)
654     Writer.AddSourceLocation(TL.getProtocolLoc(i), Record);
655 }
656 void TypeLocWriter::VisitObjCObjectPointerTypeLoc(ObjCObjectPointerTypeLoc TL) {
657   Writer.AddSourceLocation(TL.getStarLoc(), Record);
658 }
659 void TypeLocWriter::VisitAtomicTypeLoc(AtomicTypeLoc TL) {
660   Writer.AddSourceLocation(TL.getKWLoc(), Record);
661   Writer.AddSourceLocation(TL.getLParenLoc(), Record);
662   Writer.AddSourceLocation(TL.getRParenLoc(), Record);
663 }
664 
665 void ASTWriter::WriteTypeAbbrevs() {
666   using namespace llvm;
667 
668   BitCodeAbbrev *Abv;
669 
670   // Abbreviation for TYPE_EXT_QUAL
671   Abv = new BitCodeAbbrev();
672   Abv->Add(BitCodeAbbrevOp(serialization::TYPE_EXT_QUAL));
673   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // Type
674   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 3));   // Quals
675   TypeExtQualAbbrev = Stream.EmitAbbrev(Abv);
676 
677   // Abbreviation for TYPE_FUNCTION_PROTO
678   Abv = new BitCodeAbbrev();
679   Abv->Add(BitCodeAbbrevOp(serialization::TYPE_FUNCTION_PROTO));
680   // FunctionType
681   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // ReturnType
682   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // NoReturn
683   Abv->Add(BitCodeAbbrevOp(0));                         // HasRegParm
684   Abv->Add(BitCodeAbbrevOp(0));                         // RegParm
685   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // CC
686   Abv->Add(BitCodeAbbrevOp(0));                         // ProducesResult
687   // FunctionProtoType
688   Abv->Add(BitCodeAbbrevOp(0));                         // IsVariadic
689   Abv->Add(BitCodeAbbrevOp(0));                         // HasTrailingReturn
690   Abv->Add(BitCodeAbbrevOp(0));                         // TypeQuals
691   Abv->Add(BitCodeAbbrevOp(0));                         // RefQualifier
692   Abv->Add(BitCodeAbbrevOp(EST_None));                  // ExceptionSpec
693   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // NumParams
694   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
695   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // Params
696   TypeFunctionProtoAbbrev = Stream.EmitAbbrev(Abv);
697 }
698 
699 //===----------------------------------------------------------------------===//
700 // ASTWriter Implementation
701 //===----------------------------------------------------------------------===//
702 
703 static void EmitBlockID(unsigned ID, const char *Name,
704                         llvm::BitstreamWriter &Stream,
705                         ASTWriter::RecordDataImpl &Record) {
706   Record.clear();
707   Record.push_back(ID);
708   Stream.EmitRecord(llvm::bitc::BLOCKINFO_CODE_SETBID, Record);
709 
710   // Emit the block name if present.
711   if (!Name || Name[0] == 0)
712     return;
713   Record.clear();
714   while (*Name)
715     Record.push_back(*Name++);
716   Stream.EmitRecord(llvm::bitc::BLOCKINFO_CODE_BLOCKNAME, Record);
717 }
718 
719 static void EmitRecordID(unsigned ID, const char *Name,
720                          llvm::BitstreamWriter &Stream,
721                          ASTWriter::RecordDataImpl &Record) {
722   Record.clear();
723   Record.push_back(ID);
724   while (*Name)
725     Record.push_back(*Name++);
726   Stream.EmitRecord(llvm::bitc::BLOCKINFO_CODE_SETRECORDNAME, Record);
727 }
728 
729 static void AddStmtsExprs(llvm::BitstreamWriter &Stream,
730                           ASTWriter::RecordDataImpl &Record) {
731 #define RECORD(X) EmitRecordID(X, #X, Stream, Record)
732   RECORD(STMT_STOP);
733   RECORD(STMT_NULL_PTR);
734   RECORD(STMT_REF_PTR);
735   RECORD(STMT_NULL);
736   RECORD(STMT_COMPOUND);
737   RECORD(STMT_CASE);
738   RECORD(STMT_DEFAULT);
739   RECORD(STMT_LABEL);
740   RECORD(STMT_ATTRIBUTED);
741   RECORD(STMT_IF);
742   RECORD(STMT_SWITCH);
743   RECORD(STMT_WHILE);
744   RECORD(STMT_DO);
745   RECORD(STMT_FOR);
746   RECORD(STMT_GOTO);
747   RECORD(STMT_INDIRECT_GOTO);
748   RECORD(STMT_CONTINUE);
749   RECORD(STMT_BREAK);
750   RECORD(STMT_RETURN);
751   RECORD(STMT_DECL);
752   RECORD(STMT_GCCASM);
753   RECORD(STMT_MSASM);
754   RECORD(EXPR_PREDEFINED);
755   RECORD(EXPR_DECL_REF);
756   RECORD(EXPR_INTEGER_LITERAL);
757   RECORD(EXPR_FLOATING_LITERAL);
758   RECORD(EXPR_IMAGINARY_LITERAL);
759   RECORD(EXPR_STRING_LITERAL);
760   RECORD(EXPR_CHARACTER_LITERAL);
761   RECORD(EXPR_PAREN);
762   RECORD(EXPR_PAREN_LIST);
763   RECORD(EXPR_UNARY_OPERATOR);
764   RECORD(EXPR_SIZEOF_ALIGN_OF);
765   RECORD(EXPR_ARRAY_SUBSCRIPT);
766   RECORD(EXPR_CALL);
767   RECORD(EXPR_MEMBER);
768   RECORD(EXPR_BINARY_OPERATOR);
769   RECORD(EXPR_COMPOUND_ASSIGN_OPERATOR);
770   RECORD(EXPR_CONDITIONAL_OPERATOR);
771   RECORD(EXPR_IMPLICIT_CAST);
772   RECORD(EXPR_CSTYLE_CAST);
773   RECORD(EXPR_COMPOUND_LITERAL);
774   RECORD(EXPR_EXT_VECTOR_ELEMENT);
775   RECORD(EXPR_INIT_LIST);
776   RECORD(EXPR_DESIGNATED_INIT);
777   RECORD(EXPR_IMPLICIT_VALUE_INIT);
778   RECORD(EXPR_VA_ARG);
779   RECORD(EXPR_ADDR_LABEL);
780   RECORD(EXPR_STMT);
781   RECORD(EXPR_CHOOSE);
782   RECORD(EXPR_GNU_NULL);
783   RECORD(EXPR_SHUFFLE_VECTOR);
784   RECORD(EXPR_BLOCK);
785   RECORD(EXPR_GENERIC_SELECTION);
786   RECORD(EXPR_OBJC_STRING_LITERAL);
787   RECORD(EXPR_OBJC_BOXED_EXPRESSION);
788   RECORD(EXPR_OBJC_ARRAY_LITERAL);
789   RECORD(EXPR_OBJC_DICTIONARY_LITERAL);
790   RECORD(EXPR_OBJC_ENCODE);
791   RECORD(EXPR_OBJC_SELECTOR_EXPR);
792   RECORD(EXPR_OBJC_PROTOCOL_EXPR);
793   RECORD(EXPR_OBJC_IVAR_REF_EXPR);
794   RECORD(EXPR_OBJC_PROPERTY_REF_EXPR);
795   RECORD(EXPR_OBJC_KVC_REF_EXPR);
796   RECORD(EXPR_OBJC_MESSAGE_EXPR);
797   RECORD(STMT_OBJC_FOR_COLLECTION);
798   RECORD(STMT_OBJC_CATCH);
799   RECORD(STMT_OBJC_FINALLY);
800   RECORD(STMT_OBJC_AT_TRY);
801   RECORD(STMT_OBJC_AT_SYNCHRONIZED);
802   RECORD(STMT_OBJC_AT_THROW);
803   RECORD(EXPR_OBJC_BOOL_LITERAL);
804   RECORD(STMT_CXX_CATCH);
805   RECORD(STMT_CXX_TRY);
806   RECORD(STMT_CXX_FOR_RANGE);
807   RECORD(EXPR_CXX_OPERATOR_CALL);
808   RECORD(EXPR_CXX_MEMBER_CALL);
809   RECORD(EXPR_CXX_CONSTRUCT);
810   RECORD(EXPR_CXX_TEMPORARY_OBJECT);
811   RECORD(EXPR_CXX_STATIC_CAST);
812   RECORD(EXPR_CXX_DYNAMIC_CAST);
813   RECORD(EXPR_CXX_REINTERPRET_CAST);
814   RECORD(EXPR_CXX_CONST_CAST);
815   RECORD(EXPR_CXX_FUNCTIONAL_CAST);
816   RECORD(EXPR_USER_DEFINED_LITERAL);
817   RECORD(EXPR_CXX_STD_INITIALIZER_LIST);
818   RECORD(EXPR_CXX_BOOL_LITERAL);
819   RECORD(EXPR_CXX_NULL_PTR_LITERAL);
820   RECORD(EXPR_CXX_TYPEID_EXPR);
821   RECORD(EXPR_CXX_TYPEID_TYPE);
822   RECORD(EXPR_CXX_THIS);
823   RECORD(EXPR_CXX_THROW);
824   RECORD(EXPR_CXX_DEFAULT_ARG);
825   RECORD(EXPR_CXX_DEFAULT_INIT);
826   RECORD(EXPR_CXX_BIND_TEMPORARY);
827   RECORD(EXPR_CXX_SCALAR_VALUE_INIT);
828   RECORD(EXPR_CXX_NEW);
829   RECORD(EXPR_CXX_DELETE);
830   RECORD(EXPR_CXX_PSEUDO_DESTRUCTOR);
831   RECORD(EXPR_EXPR_WITH_CLEANUPS);
832   RECORD(EXPR_CXX_DEPENDENT_SCOPE_MEMBER);
833   RECORD(EXPR_CXX_DEPENDENT_SCOPE_DECL_REF);
834   RECORD(EXPR_CXX_UNRESOLVED_CONSTRUCT);
835   RECORD(EXPR_CXX_UNRESOLVED_MEMBER);
836   RECORD(EXPR_CXX_UNRESOLVED_LOOKUP);
837   RECORD(EXPR_CXX_EXPRESSION_TRAIT);
838   RECORD(EXPR_CXX_NOEXCEPT);
839   RECORD(EXPR_OPAQUE_VALUE);
840   RECORD(EXPR_BINARY_CONDITIONAL_OPERATOR);
841   RECORD(EXPR_TYPE_TRAIT);
842   RECORD(EXPR_ARRAY_TYPE_TRAIT);
843   RECORD(EXPR_PACK_EXPANSION);
844   RECORD(EXPR_SIZEOF_PACK);
845   RECORD(EXPR_SUBST_NON_TYPE_TEMPLATE_PARM);
846   RECORD(EXPR_SUBST_NON_TYPE_TEMPLATE_PARM_PACK);
847   RECORD(EXPR_FUNCTION_PARM_PACK);
848   RECORD(EXPR_MATERIALIZE_TEMPORARY);
849   RECORD(EXPR_CUDA_KERNEL_CALL);
850   RECORD(EXPR_CXX_UUIDOF_EXPR);
851   RECORD(EXPR_CXX_UUIDOF_TYPE);
852   RECORD(EXPR_LAMBDA);
853 #undef RECORD
854 }
855 
856 void ASTWriter::WriteBlockInfoBlock() {
857   RecordData Record;
858   Stream.EnterSubblock(llvm::bitc::BLOCKINFO_BLOCK_ID, 3);
859 
860 #define BLOCK(X) EmitBlockID(X ## _ID, #X, Stream, Record)
861 #define RECORD(X) EmitRecordID(X, #X, Stream, Record)
862 
863   // Control Block.
864   BLOCK(CONTROL_BLOCK);
865   RECORD(METADATA);
866   RECORD(SIGNATURE);
867   RECORD(MODULE_NAME);
868   RECORD(MODULE_MAP_FILE);
869   RECORD(IMPORTS);
870   RECORD(LANGUAGE_OPTIONS);
871   RECORD(TARGET_OPTIONS);
872   RECORD(ORIGINAL_FILE);
873   RECORD(ORIGINAL_PCH_DIR);
874   RECORD(ORIGINAL_FILE_ID);
875   RECORD(INPUT_FILE_OFFSETS);
876   RECORD(DIAGNOSTIC_OPTIONS);
877   RECORD(FILE_SYSTEM_OPTIONS);
878   RECORD(HEADER_SEARCH_OPTIONS);
879   RECORD(PREPROCESSOR_OPTIONS);
880 
881   BLOCK(INPUT_FILES_BLOCK);
882   RECORD(INPUT_FILE);
883 
884   // AST Top-Level Block.
885   BLOCK(AST_BLOCK);
886   RECORD(TYPE_OFFSET);
887   RECORD(DECL_OFFSET);
888   RECORD(IDENTIFIER_OFFSET);
889   RECORD(IDENTIFIER_TABLE);
890   RECORD(EAGERLY_DESERIALIZED_DECLS);
891   RECORD(SPECIAL_TYPES);
892   RECORD(STATISTICS);
893   RECORD(TENTATIVE_DEFINITIONS);
894   RECORD(UNUSED_FILESCOPED_DECLS);
895   RECORD(LOCALLY_SCOPED_EXTERN_C_DECLS);
896   RECORD(SELECTOR_OFFSETS);
897   RECORD(METHOD_POOL);
898   RECORD(PP_COUNTER_VALUE);
899   RECORD(SOURCE_LOCATION_OFFSETS);
900   RECORD(SOURCE_LOCATION_PRELOADS);
901   RECORD(EXT_VECTOR_DECLS);
902   RECORD(PPD_ENTITIES_OFFSETS);
903   RECORD(REFERENCED_SELECTOR_POOL);
904   RECORD(TU_UPDATE_LEXICAL);
905   RECORD(LOCAL_REDECLARATIONS_MAP);
906   RECORD(SEMA_DECL_REFS);
907   RECORD(WEAK_UNDECLARED_IDENTIFIERS);
908   RECORD(PENDING_IMPLICIT_INSTANTIATIONS);
909   RECORD(DECL_REPLACEMENTS);
910   RECORD(UPDATE_VISIBLE);
911   RECORD(DECL_UPDATE_OFFSETS);
912   RECORD(DECL_UPDATES);
913   RECORD(CXX_BASE_SPECIFIER_OFFSETS);
914   RECORD(DIAG_PRAGMA_MAPPINGS);
915   RECORD(CUDA_SPECIAL_DECL_REFS);
916   RECORD(HEADER_SEARCH_TABLE);
917   RECORD(FP_PRAGMA_OPTIONS);
918   RECORD(OPENCL_EXTENSIONS);
919   RECORD(DELEGATING_CTORS);
920   RECORD(KNOWN_NAMESPACES);
921   RECORD(UNDEFINED_BUT_USED);
922   RECORD(MODULE_OFFSET_MAP);
923   RECORD(SOURCE_MANAGER_LINE_TABLE);
924   RECORD(OBJC_CATEGORIES_MAP);
925   RECORD(FILE_SORTED_DECLS);
926   RECORD(IMPORTED_MODULES);
927   RECORD(MERGED_DECLARATIONS);
928   RECORD(LOCAL_REDECLARATIONS);
929   RECORD(OBJC_CATEGORIES);
930   RECORD(MACRO_OFFSET);
931   RECORD(MACRO_TABLE);
932   RECORD(LATE_PARSED_TEMPLATE);
933   RECORD(OPTIMIZE_PRAGMA_OPTIONS);
934 
935   // SourceManager Block.
936   BLOCK(SOURCE_MANAGER_BLOCK);
937   RECORD(SM_SLOC_FILE_ENTRY);
938   RECORD(SM_SLOC_BUFFER_ENTRY);
939   RECORD(SM_SLOC_BUFFER_BLOB);
940   RECORD(SM_SLOC_EXPANSION_ENTRY);
941 
942   // Preprocessor Block.
943   BLOCK(PREPROCESSOR_BLOCK);
944   RECORD(PP_MACRO_DIRECTIVE_HISTORY);
945   RECORD(PP_MACRO_OBJECT_LIKE);
946   RECORD(PP_MACRO_FUNCTION_LIKE);
947   RECORD(PP_TOKEN);
948 
949   // Decls and Types block.
950   BLOCK(DECLTYPES_BLOCK);
951   RECORD(TYPE_EXT_QUAL);
952   RECORD(TYPE_COMPLEX);
953   RECORD(TYPE_POINTER);
954   RECORD(TYPE_BLOCK_POINTER);
955   RECORD(TYPE_LVALUE_REFERENCE);
956   RECORD(TYPE_RVALUE_REFERENCE);
957   RECORD(TYPE_MEMBER_POINTER);
958   RECORD(TYPE_CONSTANT_ARRAY);
959   RECORD(TYPE_INCOMPLETE_ARRAY);
960   RECORD(TYPE_VARIABLE_ARRAY);
961   RECORD(TYPE_VECTOR);
962   RECORD(TYPE_EXT_VECTOR);
963   RECORD(TYPE_FUNCTION_NO_PROTO);
964   RECORD(TYPE_FUNCTION_PROTO);
965   RECORD(TYPE_TYPEDEF);
966   RECORD(TYPE_TYPEOF_EXPR);
967   RECORD(TYPE_TYPEOF);
968   RECORD(TYPE_RECORD);
969   RECORD(TYPE_ENUM);
970   RECORD(TYPE_OBJC_INTERFACE);
971   RECORD(TYPE_OBJC_OBJECT_POINTER);
972   RECORD(TYPE_DECLTYPE);
973   RECORD(TYPE_ELABORATED);
974   RECORD(TYPE_SUBST_TEMPLATE_TYPE_PARM);
975   RECORD(TYPE_UNRESOLVED_USING);
976   RECORD(TYPE_INJECTED_CLASS_NAME);
977   RECORD(TYPE_OBJC_OBJECT);
978   RECORD(TYPE_TEMPLATE_TYPE_PARM);
979   RECORD(TYPE_TEMPLATE_SPECIALIZATION);
980   RECORD(TYPE_DEPENDENT_NAME);
981   RECORD(TYPE_DEPENDENT_TEMPLATE_SPECIALIZATION);
982   RECORD(TYPE_DEPENDENT_SIZED_ARRAY);
983   RECORD(TYPE_PAREN);
984   RECORD(TYPE_PACK_EXPANSION);
985   RECORD(TYPE_ATTRIBUTED);
986   RECORD(TYPE_SUBST_TEMPLATE_TYPE_PARM_PACK);
987   RECORD(TYPE_AUTO);
988   RECORD(TYPE_UNARY_TRANSFORM);
989   RECORD(TYPE_ATOMIC);
990   RECORD(TYPE_DECAYED);
991   RECORD(TYPE_ADJUSTED);
992   RECORD(DECL_TYPEDEF);
993   RECORD(DECL_TYPEALIAS);
994   RECORD(DECL_ENUM);
995   RECORD(DECL_RECORD);
996   RECORD(DECL_ENUM_CONSTANT);
997   RECORD(DECL_FUNCTION);
998   RECORD(DECL_OBJC_METHOD);
999   RECORD(DECL_OBJC_INTERFACE);
1000   RECORD(DECL_OBJC_PROTOCOL);
1001   RECORD(DECL_OBJC_IVAR);
1002   RECORD(DECL_OBJC_AT_DEFS_FIELD);
1003   RECORD(DECL_OBJC_CATEGORY);
1004   RECORD(DECL_OBJC_CATEGORY_IMPL);
1005   RECORD(DECL_OBJC_IMPLEMENTATION);
1006   RECORD(DECL_OBJC_COMPATIBLE_ALIAS);
1007   RECORD(DECL_OBJC_PROPERTY);
1008   RECORD(DECL_OBJC_PROPERTY_IMPL);
1009   RECORD(DECL_FIELD);
1010   RECORD(DECL_MS_PROPERTY);
1011   RECORD(DECL_VAR);
1012   RECORD(DECL_IMPLICIT_PARAM);
1013   RECORD(DECL_PARM_VAR);
1014   RECORD(DECL_FILE_SCOPE_ASM);
1015   RECORD(DECL_BLOCK);
1016   RECORD(DECL_CONTEXT_LEXICAL);
1017   RECORD(DECL_CONTEXT_VISIBLE);
1018   RECORD(DECL_NAMESPACE);
1019   RECORD(DECL_NAMESPACE_ALIAS);
1020   RECORD(DECL_USING);
1021   RECORD(DECL_USING_SHADOW);
1022   RECORD(DECL_USING_DIRECTIVE);
1023   RECORD(DECL_UNRESOLVED_USING_VALUE);
1024   RECORD(DECL_UNRESOLVED_USING_TYPENAME);
1025   RECORD(DECL_LINKAGE_SPEC);
1026   RECORD(DECL_CXX_RECORD);
1027   RECORD(DECL_CXX_METHOD);
1028   RECORD(DECL_CXX_CONSTRUCTOR);
1029   RECORD(DECL_CXX_DESTRUCTOR);
1030   RECORD(DECL_CXX_CONVERSION);
1031   RECORD(DECL_ACCESS_SPEC);
1032   RECORD(DECL_FRIEND);
1033   RECORD(DECL_FRIEND_TEMPLATE);
1034   RECORD(DECL_CLASS_TEMPLATE);
1035   RECORD(DECL_CLASS_TEMPLATE_SPECIALIZATION);
1036   RECORD(DECL_CLASS_TEMPLATE_PARTIAL_SPECIALIZATION);
1037   RECORD(DECL_VAR_TEMPLATE);
1038   RECORD(DECL_VAR_TEMPLATE_SPECIALIZATION);
1039   RECORD(DECL_VAR_TEMPLATE_PARTIAL_SPECIALIZATION);
1040   RECORD(DECL_FUNCTION_TEMPLATE);
1041   RECORD(DECL_TEMPLATE_TYPE_PARM);
1042   RECORD(DECL_NON_TYPE_TEMPLATE_PARM);
1043   RECORD(DECL_TEMPLATE_TEMPLATE_PARM);
1044   RECORD(DECL_STATIC_ASSERT);
1045   RECORD(DECL_CXX_BASE_SPECIFIERS);
1046   RECORD(DECL_INDIRECTFIELD);
1047   RECORD(DECL_EXPANDED_NON_TYPE_TEMPLATE_PARM_PACK);
1048 
1049   // Statements and Exprs can occur in the Decls and Types block.
1050   AddStmtsExprs(Stream, Record);
1051 
1052   BLOCK(PREPROCESSOR_DETAIL_BLOCK);
1053   RECORD(PPD_MACRO_EXPANSION);
1054   RECORD(PPD_MACRO_DEFINITION);
1055   RECORD(PPD_INCLUSION_DIRECTIVE);
1056 
1057 #undef RECORD
1058 #undef BLOCK
1059   Stream.ExitBlock();
1060 }
1061 
1062 /// \brief Prepares a path for being written to an AST file by converting it
1063 /// to an absolute path and removing nested './'s.
1064 ///
1065 /// \return \c true if the path was changed.
1066 static bool cleanPathForOutput(FileManager &FileMgr,
1067                                SmallVectorImpl<char> &Path) {
1068   bool Changed = false;
1069 
1070   if (!llvm::sys::path::is_absolute(StringRef(Path.data(), Path.size()))) {
1071     llvm::sys::fs::make_absolute(Path);
1072     Changed = true;
1073   }
1074 
1075   return Changed | FileMgr.removeDotPaths(Path);
1076 }
1077 
1078 /// \brief Adjusts the given filename to only write out the portion of the
1079 /// filename that is not part of the system root directory.
1080 ///
1081 /// \param Filename the file name to adjust.
1082 ///
1083 /// \param BaseDir When non-NULL, the PCH file is a relocatable AST file and
1084 /// the returned filename will be adjusted by this root directory.
1085 ///
1086 /// \returns either the original filename (if it needs no adjustment) or the
1087 /// adjusted filename (which points into the @p Filename parameter).
1088 static const char *
1089 adjustFilenameForRelocatableAST(const char *Filename, StringRef BaseDir) {
1090   assert(Filename && "No file name to adjust?");
1091 
1092   if (BaseDir.empty())
1093     return Filename;
1094 
1095   // Verify that the filename and the system root have the same prefix.
1096   unsigned Pos = 0;
1097   for (; Filename[Pos] && Pos < BaseDir.size(); ++Pos)
1098     if (Filename[Pos] != BaseDir[Pos])
1099       return Filename; // Prefixes don't match.
1100 
1101   // We hit the end of the filename before we hit the end of the system root.
1102   if (!Filename[Pos])
1103     return Filename;
1104 
1105   // If there's not a path separator at the end of the base directory nor
1106   // immediately after it, then this isn't within the base directory.
1107   if (!llvm::sys::path::is_separator(Filename[Pos])) {
1108     if (!llvm::sys::path::is_separator(BaseDir.back()))
1109       return Filename;
1110   } else {
1111     // If the file name has a '/' at the current position, skip over the '/'.
1112     // We distinguish relative paths from absolute paths by the
1113     // absence of '/' at the beginning of relative paths.
1114     //
1115     // FIXME: This is wrong. We distinguish them by asking if the path is
1116     // absolute, which isn't the same thing. And there might be multiple '/'s
1117     // in a row. Use a better mechanism to indicate whether we have emitted an
1118     // absolute or relative path.
1119     ++Pos;
1120   }
1121 
1122   return Filename + Pos;
1123 }
1124 
1125 static ASTFileSignature getSignature() {
1126   while (1) {
1127     if (ASTFileSignature S = llvm::sys::Process::GetRandomNumber())
1128       return S;
1129     // Rely on GetRandomNumber to eventually return non-zero...
1130   }
1131 }
1132 
1133 /// \brief Write the control block.
1134 void ASTWriter::WriteControlBlock(Preprocessor &PP, ASTContext &Context,
1135                                   StringRef isysroot,
1136                                   const std::string &OutputFile) {
1137   using namespace llvm;
1138   Stream.EnterSubblock(CONTROL_BLOCK_ID, 5);
1139   RecordData Record;
1140 
1141   // Metadata
1142   BitCodeAbbrev *MetadataAbbrev = new BitCodeAbbrev();
1143   MetadataAbbrev->Add(BitCodeAbbrevOp(METADATA));
1144   MetadataAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 16)); // Major
1145   MetadataAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 16)); // Minor
1146   MetadataAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 16)); // Clang maj.
1147   MetadataAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 16)); // Clang min.
1148   MetadataAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Relocatable
1149   MetadataAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Errors
1150   MetadataAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // SVN branch/tag
1151   unsigned MetadataAbbrevCode = Stream.EmitAbbrev(MetadataAbbrev);
1152   Record.push_back(METADATA);
1153   Record.push_back(VERSION_MAJOR);
1154   Record.push_back(VERSION_MINOR);
1155   Record.push_back(CLANG_VERSION_MAJOR);
1156   Record.push_back(CLANG_VERSION_MINOR);
1157   assert((!WritingModule || isysroot.empty()) &&
1158          "writing module as a relocatable PCH?");
1159   Record.push_back(!isysroot.empty());
1160   Record.push_back(ASTHasCompilerErrors);
1161   Stream.EmitRecordWithBlob(MetadataAbbrevCode, Record,
1162                             getClangFullRepositoryVersion());
1163 
1164   // Signature
1165   Record.clear();
1166   Record.push_back(getSignature());
1167   Stream.EmitRecord(SIGNATURE, Record);
1168 
1169   if (WritingModule) {
1170     // Module name
1171     BitCodeAbbrev *Abbrev = new BitCodeAbbrev();
1172     Abbrev->Add(BitCodeAbbrevOp(MODULE_NAME));
1173     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Name
1174     unsigned AbbrevCode = Stream.EmitAbbrev(Abbrev);
1175     RecordData Record;
1176     Record.push_back(MODULE_NAME);
1177     Stream.EmitRecordWithBlob(AbbrevCode, Record, WritingModule->Name);
1178   }
1179 
1180   if (WritingModule && WritingModule->Directory) {
1181     // Module directory.
1182     BitCodeAbbrev *Abbrev = new BitCodeAbbrev();
1183     Abbrev->Add(BitCodeAbbrevOp(MODULE_DIRECTORY));
1184     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Directory
1185     unsigned AbbrevCode = Stream.EmitAbbrev(Abbrev);
1186     RecordData Record;
1187     Record.push_back(MODULE_DIRECTORY);
1188 
1189     SmallString<128> BaseDir(WritingModule->Directory->getName());
1190     cleanPathForOutput(Context.getSourceManager().getFileManager(), BaseDir);
1191     Stream.EmitRecordWithBlob(AbbrevCode, Record, BaseDir);
1192 
1193     // Write out all other paths relative to the base directory if possible.
1194     BaseDirectory.assign(BaseDir.begin(), BaseDir.end());
1195   } else if (!isysroot.empty()) {
1196     // Write out paths relative to the sysroot if possible.
1197     BaseDirectory = isysroot;
1198   }
1199 
1200   // Module map file
1201   if (WritingModule) {
1202     Record.clear();
1203 
1204     auto &Map = PP.getHeaderSearchInfo().getModuleMap();
1205 
1206     // Primary module map file.
1207     AddPath(Map.getModuleMapFileForUniquing(WritingModule)->getName(), Record);
1208 
1209     // Additional module map files.
1210     if (auto *AdditionalModMaps =
1211             Map.getAdditionalModuleMapFiles(WritingModule)) {
1212       Record.push_back(AdditionalModMaps->size());
1213       for (const FileEntry *F : *AdditionalModMaps)
1214         AddPath(F->getName(), Record);
1215     } else {
1216       Record.push_back(0);
1217     }
1218 
1219     Stream.EmitRecord(MODULE_MAP_FILE, Record);
1220   }
1221 
1222   // Imports
1223   if (Chain) {
1224     serialization::ModuleManager &Mgr = Chain->getModuleManager();
1225     Record.clear();
1226 
1227     for (ModuleManager::ModuleIterator M = Mgr.begin(), MEnd = Mgr.end();
1228          M != MEnd; ++M) {
1229       // Skip modules that weren't directly imported.
1230       if (!(*M)->isDirectlyImported())
1231         continue;
1232 
1233       Record.push_back((unsigned)(*M)->Kind); // FIXME: Stable encoding
1234       AddSourceLocation((*M)->ImportLoc, Record);
1235       Record.push_back((*M)->File->getSize());
1236       Record.push_back((*M)->File->getModificationTime());
1237       Record.push_back((*M)->Signature);
1238       AddPath((*M)->FileName, Record);
1239     }
1240     Stream.EmitRecord(IMPORTS, Record);
1241   }
1242 
1243   // Language options.
1244   Record.clear();
1245   const LangOptions &LangOpts = Context.getLangOpts();
1246 #define LANGOPT(Name, Bits, Default, Description) \
1247   Record.push_back(LangOpts.Name);
1248 #define ENUM_LANGOPT(Name, Type, Bits, Default, Description) \
1249   Record.push_back(static_cast<unsigned>(LangOpts.get##Name()));
1250 #include "clang/Basic/LangOptions.def"
1251 #define SANITIZER(NAME, ID)                                                    \
1252   Record.push_back(LangOpts.Sanitize.has(SanitizerKind::ID));
1253 #include "clang/Basic/Sanitizers.def"
1254 
1255   Record.push_back((unsigned) LangOpts.ObjCRuntime.getKind());
1256   AddVersionTuple(LangOpts.ObjCRuntime.getVersion(), Record);
1257 
1258   Record.push_back(LangOpts.CurrentModule.size());
1259   Record.append(LangOpts.CurrentModule.begin(), LangOpts.CurrentModule.end());
1260 
1261   // Comment options.
1262   Record.push_back(LangOpts.CommentOpts.BlockCommandNames.size());
1263   for (CommentOptions::BlockCommandNamesTy::const_iterator
1264            I = LangOpts.CommentOpts.BlockCommandNames.begin(),
1265            IEnd = LangOpts.CommentOpts.BlockCommandNames.end();
1266        I != IEnd; ++I) {
1267     AddString(*I, Record);
1268   }
1269   Record.push_back(LangOpts.CommentOpts.ParseAllComments);
1270 
1271   Stream.EmitRecord(LANGUAGE_OPTIONS, Record);
1272 
1273   // Target options.
1274   Record.clear();
1275   const TargetInfo &Target = Context.getTargetInfo();
1276   const TargetOptions &TargetOpts = Target.getTargetOpts();
1277   AddString(TargetOpts.Triple, Record);
1278   AddString(TargetOpts.CPU, Record);
1279   AddString(TargetOpts.ABI, Record);
1280   Record.push_back(TargetOpts.FeaturesAsWritten.size());
1281   for (unsigned I = 0, N = TargetOpts.FeaturesAsWritten.size(); I != N; ++I) {
1282     AddString(TargetOpts.FeaturesAsWritten[I], Record);
1283   }
1284   Record.push_back(TargetOpts.Features.size());
1285   for (unsigned I = 0, N = TargetOpts.Features.size(); I != N; ++I) {
1286     AddString(TargetOpts.Features[I], Record);
1287   }
1288   Stream.EmitRecord(TARGET_OPTIONS, Record);
1289 
1290   // Diagnostic options.
1291   Record.clear();
1292   const DiagnosticOptions &DiagOpts
1293     = Context.getDiagnostics().getDiagnosticOptions();
1294 #define DIAGOPT(Name, Bits, Default) Record.push_back(DiagOpts.Name);
1295 #define ENUM_DIAGOPT(Name, Type, Bits, Default) \
1296   Record.push_back(static_cast<unsigned>(DiagOpts.get##Name()));
1297 #include "clang/Basic/DiagnosticOptions.def"
1298   Record.push_back(DiagOpts.Warnings.size());
1299   for (unsigned I = 0, N = DiagOpts.Warnings.size(); I != N; ++I)
1300     AddString(DiagOpts.Warnings[I], Record);
1301   Record.push_back(DiagOpts.Remarks.size());
1302   for (unsigned I = 0, N = DiagOpts.Remarks.size(); I != N; ++I)
1303     AddString(DiagOpts.Remarks[I], Record);
1304   // Note: we don't serialize the log or serialization file names, because they
1305   // are generally transient files and will almost always be overridden.
1306   Stream.EmitRecord(DIAGNOSTIC_OPTIONS, Record);
1307 
1308   // File system options.
1309   Record.clear();
1310   const FileSystemOptions &FSOpts
1311     = Context.getSourceManager().getFileManager().getFileSystemOptions();
1312   AddString(FSOpts.WorkingDir, Record);
1313   Stream.EmitRecord(FILE_SYSTEM_OPTIONS, Record);
1314 
1315   // Header search options.
1316   Record.clear();
1317   const HeaderSearchOptions &HSOpts
1318     = PP.getHeaderSearchInfo().getHeaderSearchOpts();
1319   AddString(HSOpts.Sysroot, Record);
1320 
1321   // Include entries.
1322   Record.push_back(HSOpts.UserEntries.size());
1323   for (unsigned I = 0, N = HSOpts.UserEntries.size(); I != N; ++I) {
1324     const HeaderSearchOptions::Entry &Entry = HSOpts.UserEntries[I];
1325     AddString(Entry.Path, Record);
1326     Record.push_back(static_cast<unsigned>(Entry.Group));
1327     Record.push_back(Entry.IsFramework);
1328     Record.push_back(Entry.IgnoreSysRoot);
1329   }
1330 
1331   // System header prefixes.
1332   Record.push_back(HSOpts.SystemHeaderPrefixes.size());
1333   for (unsigned I = 0, N = HSOpts.SystemHeaderPrefixes.size(); I != N; ++I) {
1334     AddString(HSOpts.SystemHeaderPrefixes[I].Prefix, Record);
1335     Record.push_back(HSOpts.SystemHeaderPrefixes[I].IsSystemHeader);
1336   }
1337 
1338   AddString(HSOpts.ResourceDir, Record);
1339   AddString(HSOpts.ModuleCachePath, Record);
1340   AddString(HSOpts.ModuleUserBuildPath, Record);
1341   Record.push_back(HSOpts.DisableModuleHash);
1342   Record.push_back(HSOpts.UseBuiltinIncludes);
1343   Record.push_back(HSOpts.UseStandardSystemIncludes);
1344   Record.push_back(HSOpts.UseStandardCXXIncludes);
1345   Record.push_back(HSOpts.UseLibcxx);
1346   // Write out the specific module cache path that contains the module files.
1347   AddString(PP.getHeaderSearchInfo().getModuleCachePath(), Record);
1348   Stream.EmitRecord(HEADER_SEARCH_OPTIONS, Record);
1349 
1350   // Preprocessor options.
1351   Record.clear();
1352   const PreprocessorOptions &PPOpts = PP.getPreprocessorOpts();
1353 
1354   // Macro definitions.
1355   Record.push_back(PPOpts.Macros.size());
1356   for (unsigned I = 0, N = PPOpts.Macros.size(); I != N; ++I) {
1357     AddString(PPOpts.Macros[I].first, Record);
1358     Record.push_back(PPOpts.Macros[I].second);
1359   }
1360 
1361   // Includes
1362   Record.push_back(PPOpts.Includes.size());
1363   for (unsigned I = 0, N = PPOpts.Includes.size(); I != N; ++I)
1364     AddString(PPOpts.Includes[I], Record);
1365 
1366   // Macro includes
1367   Record.push_back(PPOpts.MacroIncludes.size());
1368   for (unsigned I = 0, N = PPOpts.MacroIncludes.size(); I != N; ++I)
1369     AddString(PPOpts.MacroIncludes[I], Record);
1370 
1371   Record.push_back(PPOpts.UsePredefines);
1372   // Detailed record is important since it is used for the module cache hash.
1373   Record.push_back(PPOpts.DetailedRecord);
1374   AddString(PPOpts.ImplicitPCHInclude, Record);
1375   AddString(PPOpts.ImplicitPTHInclude, Record);
1376   Record.push_back(static_cast<unsigned>(PPOpts.ObjCXXARCStandardLibrary));
1377   Stream.EmitRecord(PREPROCESSOR_OPTIONS, Record);
1378 
1379   // Original file name and file ID
1380   SourceManager &SM = Context.getSourceManager();
1381   if (const FileEntry *MainFile = SM.getFileEntryForID(SM.getMainFileID())) {
1382     BitCodeAbbrev *FileAbbrev = new BitCodeAbbrev();
1383     FileAbbrev->Add(BitCodeAbbrevOp(ORIGINAL_FILE));
1384     FileAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // File ID
1385     FileAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // File name
1386     unsigned FileAbbrevCode = Stream.EmitAbbrev(FileAbbrev);
1387 
1388     Record.clear();
1389     Record.push_back(ORIGINAL_FILE);
1390     Record.push_back(SM.getMainFileID().getOpaqueValue());
1391     EmitRecordWithPath(FileAbbrevCode, Record, MainFile->getName());
1392   }
1393 
1394   Record.clear();
1395   Record.push_back(SM.getMainFileID().getOpaqueValue());
1396   Stream.EmitRecord(ORIGINAL_FILE_ID, Record);
1397 
1398   // Original PCH directory
1399   if (!OutputFile.empty() && OutputFile != "-") {
1400     BitCodeAbbrev *Abbrev = new BitCodeAbbrev();
1401     Abbrev->Add(BitCodeAbbrevOp(ORIGINAL_PCH_DIR));
1402     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // File name
1403     unsigned AbbrevCode = Stream.EmitAbbrev(Abbrev);
1404 
1405     SmallString<128> OutputPath(OutputFile);
1406 
1407     llvm::sys::fs::make_absolute(OutputPath);
1408     StringRef origDir = llvm::sys::path::parent_path(OutputPath);
1409 
1410     RecordData Record;
1411     Record.push_back(ORIGINAL_PCH_DIR);
1412     Stream.EmitRecordWithBlob(AbbrevCode, Record, origDir);
1413   }
1414 
1415   WriteInputFiles(Context.SourceMgr,
1416                   PP.getHeaderSearchInfo().getHeaderSearchOpts(),
1417                   PP.getLangOpts().Modules);
1418   Stream.ExitBlock();
1419 }
1420 
1421 namespace  {
1422   /// \brief An input file.
1423   struct InputFileEntry {
1424     const FileEntry *File;
1425     bool IsSystemFile;
1426     bool BufferOverridden;
1427   };
1428 }
1429 
1430 void ASTWriter::WriteInputFiles(SourceManager &SourceMgr,
1431                                 HeaderSearchOptions &HSOpts,
1432                                 bool Modules) {
1433   using namespace llvm;
1434   Stream.EnterSubblock(INPUT_FILES_BLOCK_ID, 4);
1435   RecordData Record;
1436 
1437   // Create input-file abbreviation.
1438   BitCodeAbbrev *IFAbbrev = new BitCodeAbbrev();
1439   IFAbbrev->Add(BitCodeAbbrevOp(INPUT_FILE));
1440   IFAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // ID
1441   IFAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 12)); // Size
1442   IFAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 32)); // Modification time
1443   IFAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Overridden
1444   IFAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // File name
1445   unsigned IFAbbrevCode = Stream.EmitAbbrev(IFAbbrev);
1446 
1447   // Get all ContentCache objects for files, sorted by whether the file is a
1448   // system one or not. System files go at the back, users files at the front.
1449   std::deque<InputFileEntry> SortedFiles;
1450   for (unsigned I = 1, N = SourceMgr.local_sloc_entry_size(); I != N; ++I) {
1451     // Get this source location entry.
1452     const SrcMgr::SLocEntry *SLoc = &SourceMgr.getLocalSLocEntry(I);
1453     assert(&SourceMgr.getSLocEntry(FileID::get(I)) == SLoc);
1454 
1455     // We only care about file entries that were not overridden.
1456     if (!SLoc->isFile())
1457       continue;
1458     const SrcMgr::ContentCache *Cache = SLoc->getFile().getContentCache();
1459     if (!Cache->OrigEntry)
1460       continue;
1461 
1462     InputFileEntry Entry;
1463     Entry.File = Cache->OrigEntry;
1464     Entry.IsSystemFile = Cache->IsSystemFile;
1465     Entry.BufferOverridden = Cache->BufferOverridden;
1466     if (Cache->IsSystemFile)
1467       SortedFiles.push_back(Entry);
1468     else
1469       SortedFiles.push_front(Entry);
1470   }
1471 
1472   unsigned UserFilesNum = 0;
1473   // Write out all of the input files.
1474   std::vector<uint64_t> InputFileOffsets;
1475   for (std::deque<InputFileEntry>::iterator
1476          I = SortedFiles.begin(), E = SortedFiles.end(); I != E; ++I) {
1477     const InputFileEntry &Entry = *I;
1478 
1479     uint32_t &InputFileID = InputFileIDs[Entry.File];
1480     if (InputFileID != 0)
1481       continue; // already recorded this file.
1482 
1483     // Record this entry's offset.
1484     InputFileOffsets.push_back(Stream.GetCurrentBitNo());
1485 
1486     InputFileID = InputFileOffsets.size();
1487 
1488     if (!Entry.IsSystemFile)
1489       ++UserFilesNum;
1490 
1491     Record.clear();
1492     Record.push_back(INPUT_FILE);
1493     Record.push_back(InputFileOffsets.size());
1494 
1495     // Emit size/modification time for this file.
1496     Record.push_back(Entry.File->getSize());
1497     Record.push_back(Entry.File->getModificationTime());
1498 
1499     // Whether this file was overridden.
1500     Record.push_back(Entry.BufferOverridden);
1501 
1502     EmitRecordWithPath(IFAbbrevCode, Record, Entry.File->getName());
1503   }
1504 
1505   Stream.ExitBlock();
1506 
1507   // Create input file offsets abbreviation.
1508   BitCodeAbbrev *OffsetsAbbrev = new BitCodeAbbrev();
1509   OffsetsAbbrev->Add(BitCodeAbbrevOp(INPUT_FILE_OFFSETS));
1510   OffsetsAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // # input files
1511   OffsetsAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // # non-system
1512                                                                 //   input files
1513   OffsetsAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));   // Array
1514   unsigned OffsetsAbbrevCode = Stream.EmitAbbrev(OffsetsAbbrev);
1515 
1516   // Write input file offsets.
1517   Record.clear();
1518   Record.push_back(INPUT_FILE_OFFSETS);
1519   Record.push_back(InputFileOffsets.size());
1520   Record.push_back(UserFilesNum);
1521   Stream.EmitRecordWithBlob(OffsetsAbbrevCode, Record, data(InputFileOffsets));
1522 }
1523 
1524 //===----------------------------------------------------------------------===//
1525 // Source Manager Serialization
1526 //===----------------------------------------------------------------------===//
1527 
1528 /// \brief Create an abbreviation for the SLocEntry that refers to a
1529 /// file.
1530 static unsigned CreateSLocFileAbbrev(llvm::BitstreamWriter &Stream) {
1531   using namespace llvm;
1532   BitCodeAbbrev *Abbrev = new BitCodeAbbrev();
1533   Abbrev->Add(BitCodeAbbrevOp(SM_SLOC_FILE_ENTRY));
1534   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // Offset
1535   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // Include location
1536   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2)); // Characteristic
1537   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Line directives
1538   // FileEntry fields.
1539   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Input File ID
1540   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // NumCreatedFIDs
1541   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 24)); // FirstDeclIndex
1542   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // NumDecls
1543   return Stream.EmitAbbrev(Abbrev);
1544 }
1545 
1546 /// \brief Create an abbreviation for the SLocEntry that refers to a
1547 /// buffer.
1548 static unsigned CreateSLocBufferAbbrev(llvm::BitstreamWriter &Stream) {
1549   using namespace llvm;
1550   BitCodeAbbrev *Abbrev = new BitCodeAbbrev();
1551   Abbrev->Add(BitCodeAbbrevOp(SM_SLOC_BUFFER_ENTRY));
1552   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // Offset
1553   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // Include location
1554   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2)); // Characteristic
1555   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Line directives
1556   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Buffer name blob
1557   return Stream.EmitAbbrev(Abbrev);
1558 }
1559 
1560 /// \brief Create an abbreviation for the SLocEntry that refers to a
1561 /// buffer's blob.
1562 static unsigned CreateSLocBufferBlobAbbrev(llvm::BitstreamWriter &Stream) {
1563   using namespace llvm;
1564   BitCodeAbbrev *Abbrev = new BitCodeAbbrev();
1565   Abbrev->Add(BitCodeAbbrevOp(SM_SLOC_BUFFER_BLOB));
1566   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Blob
1567   return Stream.EmitAbbrev(Abbrev);
1568 }
1569 
1570 /// \brief Create an abbreviation for the SLocEntry that refers to a macro
1571 /// expansion.
1572 static unsigned CreateSLocExpansionAbbrev(llvm::BitstreamWriter &Stream) {
1573   using namespace llvm;
1574   BitCodeAbbrev *Abbrev = new BitCodeAbbrev();
1575   Abbrev->Add(BitCodeAbbrevOp(SM_SLOC_EXPANSION_ENTRY));
1576   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // Offset
1577   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // Spelling location
1578   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // Start location
1579   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // End location
1580   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Token length
1581   return Stream.EmitAbbrev(Abbrev);
1582 }
1583 
1584 namespace {
1585   // Trait used for the on-disk hash table of header search information.
1586   class HeaderFileInfoTrait {
1587     ASTWriter &Writer;
1588     const HeaderSearch &HS;
1589 
1590     // Keep track of the framework names we've used during serialization.
1591     SmallVector<char, 128> FrameworkStringData;
1592     llvm::StringMap<unsigned> FrameworkNameOffset;
1593 
1594   public:
1595     HeaderFileInfoTrait(ASTWriter &Writer, const HeaderSearch &HS)
1596       : Writer(Writer), HS(HS) { }
1597 
1598     struct key_type {
1599       const FileEntry *FE;
1600       const char *Filename;
1601     };
1602     typedef const key_type &key_type_ref;
1603 
1604     typedef HeaderFileInfo data_type;
1605     typedef const data_type &data_type_ref;
1606     typedef unsigned hash_value_type;
1607     typedef unsigned offset_type;
1608 
1609     static hash_value_type ComputeHash(key_type_ref key) {
1610       // The hash is based only on size/time of the file, so that the reader can
1611       // match even when symlinking or excess path elements ("foo/../", "../")
1612       // change the form of the name. However, complete path is still the key.
1613       //
1614       // FIXME: Using the mtime here will cause problems for explicit module
1615       // imports.
1616       return llvm::hash_combine(key.FE->getSize(),
1617                                 key.FE->getModificationTime());
1618     }
1619 
1620     std::pair<unsigned,unsigned>
1621     EmitKeyDataLength(raw_ostream& Out, key_type_ref key, data_type_ref Data) {
1622       using namespace llvm::support;
1623       endian::Writer<little> Writer(Out);
1624       unsigned KeyLen = strlen(key.Filename) + 1 + 8 + 8;
1625       Writer.write<uint16_t>(KeyLen);
1626       unsigned DataLen = 1 + 2 + 4 + 4;
1627       if (Data.isModuleHeader)
1628         DataLen += 4;
1629       Writer.write<uint8_t>(DataLen);
1630       return std::make_pair(KeyLen, DataLen);
1631     }
1632 
1633     void EmitKey(raw_ostream& Out, key_type_ref key, unsigned KeyLen) {
1634       using namespace llvm::support;
1635       endian::Writer<little> LE(Out);
1636       LE.write<uint64_t>(key.FE->getSize());
1637       KeyLen -= 8;
1638       LE.write<uint64_t>(key.FE->getModificationTime());
1639       KeyLen -= 8;
1640       Out.write(key.Filename, KeyLen);
1641     }
1642 
1643     void EmitData(raw_ostream &Out, key_type_ref key,
1644                   data_type_ref Data, unsigned DataLen) {
1645       using namespace llvm::support;
1646       endian::Writer<little> LE(Out);
1647       uint64_t Start = Out.tell(); (void)Start;
1648 
1649       unsigned char Flags = (Data.HeaderRole << 6)
1650                           | (Data.isImport << 5)
1651                           | (Data.isPragmaOnce << 4)
1652                           | (Data.DirInfo << 2)
1653                           | (Data.Resolved << 1)
1654                           | Data.IndexHeaderMapHeader;
1655       LE.write<uint8_t>(Flags);
1656       LE.write<uint16_t>(Data.NumIncludes);
1657 
1658       if (!Data.ControllingMacro)
1659         LE.write<uint32_t>(Data.ControllingMacroID);
1660       else
1661         LE.write<uint32_t>(Writer.getIdentifierRef(Data.ControllingMacro));
1662 
1663       unsigned Offset = 0;
1664       if (!Data.Framework.empty()) {
1665         // If this header refers into a framework, save the framework name.
1666         llvm::StringMap<unsigned>::iterator Pos
1667           = FrameworkNameOffset.find(Data.Framework);
1668         if (Pos == FrameworkNameOffset.end()) {
1669           Offset = FrameworkStringData.size() + 1;
1670           FrameworkStringData.append(Data.Framework.begin(),
1671                                      Data.Framework.end());
1672           FrameworkStringData.push_back(0);
1673 
1674           FrameworkNameOffset[Data.Framework] = Offset;
1675         } else
1676           Offset = Pos->second;
1677       }
1678       LE.write<uint32_t>(Offset);
1679 
1680       if (Data.isModuleHeader) {
1681         Module *Mod = HS.findModuleForHeader(key.FE).getModule();
1682         LE.write<uint32_t>(Writer.getExistingSubmoduleID(Mod));
1683       }
1684 
1685       assert(Out.tell() - Start == DataLen && "Wrong data length");
1686     }
1687 
1688     const char *strings_begin() const { return FrameworkStringData.begin(); }
1689     const char *strings_end() const { return FrameworkStringData.end(); }
1690   };
1691 } // end anonymous namespace
1692 
1693 /// \brief Write the header search block for the list of files that
1694 ///
1695 /// \param HS The header search structure to save.
1696 void ASTWriter::WriteHeaderSearch(const HeaderSearch &HS) {
1697   SmallVector<const FileEntry *, 16> FilesByUID;
1698   HS.getFileMgr().GetUniqueIDMapping(FilesByUID);
1699 
1700   if (FilesByUID.size() > HS.header_file_size())
1701     FilesByUID.resize(HS.header_file_size());
1702 
1703   HeaderFileInfoTrait GeneratorTrait(*this, HS);
1704   llvm::OnDiskChainedHashTableGenerator<HeaderFileInfoTrait> Generator;
1705   SmallVector<const char *, 4> SavedStrings;
1706   unsigned NumHeaderSearchEntries = 0;
1707   for (unsigned UID = 0, LastUID = FilesByUID.size(); UID != LastUID; ++UID) {
1708     const FileEntry *File = FilesByUID[UID];
1709     if (!File)
1710       continue;
1711 
1712     // Use HeaderSearch's getFileInfo to make sure we get the HeaderFileInfo
1713     // from the external source if it was not provided already.
1714     HeaderFileInfo HFI;
1715     if (!HS.tryGetFileInfo(File, HFI) ||
1716         (HFI.External && Chain) ||
1717         (HFI.isModuleHeader && !HFI.isCompilingModuleHeader))
1718       continue;
1719 
1720     // Massage the file path into an appropriate form.
1721     const char *Filename = File->getName();
1722     SmallString<128> FilenameTmp(Filename);
1723     if (PreparePathForOutput(FilenameTmp)) {
1724       // If we performed any translation on the file name at all, we need to
1725       // save this string, since the generator will refer to it later.
1726       Filename = strdup(FilenameTmp.c_str());
1727       SavedStrings.push_back(Filename);
1728     }
1729 
1730     HeaderFileInfoTrait::key_type key = { File, Filename };
1731     Generator.insert(key, HFI, GeneratorTrait);
1732     ++NumHeaderSearchEntries;
1733   }
1734 
1735   // Create the on-disk hash table in a buffer.
1736   SmallString<4096> TableData;
1737   uint32_t BucketOffset;
1738   {
1739     using namespace llvm::support;
1740     llvm::raw_svector_ostream Out(TableData);
1741     // Make sure that no bucket is at offset 0
1742     endian::Writer<little>(Out).write<uint32_t>(0);
1743     BucketOffset = Generator.Emit(Out, GeneratorTrait);
1744   }
1745 
1746   // Create a blob abbreviation
1747   using namespace llvm;
1748   BitCodeAbbrev *Abbrev = new BitCodeAbbrev();
1749   Abbrev->Add(BitCodeAbbrevOp(HEADER_SEARCH_TABLE));
1750   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
1751   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
1752   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
1753   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
1754   unsigned TableAbbrev = Stream.EmitAbbrev(Abbrev);
1755 
1756   // Write the header search table
1757   RecordData Record;
1758   Record.push_back(HEADER_SEARCH_TABLE);
1759   Record.push_back(BucketOffset);
1760   Record.push_back(NumHeaderSearchEntries);
1761   Record.push_back(TableData.size());
1762   TableData.append(GeneratorTrait.strings_begin(),GeneratorTrait.strings_end());
1763   Stream.EmitRecordWithBlob(TableAbbrev, Record, TableData.str());
1764 
1765   // Free all of the strings we had to duplicate.
1766   for (unsigned I = 0, N = SavedStrings.size(); I != N; ++I)
1767     free(const_cast<char *>(SavedStrings[I]));
1768 }
1769 
1770 /// \brief Writes the block containing the serialized form of the
1771 /// source manager.
1772 ///
1773 /// TODO: We should probably use an on-disk hash table (stored in a
1774 /// blob), indexed based on the file name, so that we only create
1775 /// entries for files that we actually need. In the common case (no
1776 /// errors), we probably won't have to create file entries for any of
1777 /// the files in the AST.
1778 void ASTWriter::WriteSourceManagerBlock(SourceManager &SourceMgr,
1779                                         const Preprocessor &PP) {
1780   RecordData Record;
1781 
1782   // Enter the source manager block.
1783   Stream.EnterSubblock(SOURCE_MANAGER_BLOCK_ID, 3);
1784 
1785   // Abbreviations for the various kinds of source-location entries.
1786   unsigned SLocFileAbbrv = CreateSLocFileAbbrev(Stream);
1787   unsigned SLocBufferAbbrv = CreateSLocBufferAbbrev(Stream);
1788   unsigned SLocBufferBlobAbbrv = CreateSLocBufferBlobAbbrev(Stream);
1789   unsigned SLocExpansionAbbrv = CreateSLocExpansionAbbrev(Stream);
1790 
1791   // Write out the source location entry table. We skip the first
1792   // entry, which is always the same dummy entry.
1793   std::vector<uint32_t> SLocEntryOffsets;
1794   RecordData PreloadSLocs;
1795   SLocEntryOffsets.reserve(SourceMgr.local_sloc_entry_size() - 1);
1796   for (unsigned I = 1, N = SourceMgr.local_sloc_entry_size();
1797        I != N; ++I) {
1798     // Get this source location entry.
1799     const SrcMgr::SLocEntry *SLoc = &SourceMgr.getLocalSLocEntry(I);
1800     FileID FID = FileID::get(I);
1801     assert(&SourceMgr.getSLocEntry(FID) == SLoc);
1802 
1803     // Record the offset of this source-location entry.
1804     SLocEntryOffsets.push_back(Stream.GetCurrentBitNo());
1805 
1806     // Figure out which record code to use.
1807     unsigned Code;
1808     if (SLoc->isFile()) {
1809       const SrcMgr::ContentCache *Cache = SLoc->getFile().getContentCache();
1810       if (Cache->OrigEntry) {
1811         Code = SM_SLOC_FILE_ENTRY;
1812       } else
1813         Code = SM_SLOC_BUFFER_ENTRY;
1814     } else
1815       Code = SM_SLOC_EXPANSION_ENTRY;
1816     Record.clear();
1817     Record.push_back(Code);
1818 
1819     // Starting offset of this entry within this module, so skip the dummy.
1820     Record.push_back(SLoc->getOffset() - 2);
1821     if (SLoc->isFile()) {
1822       const SrcMgr::FileInfo &File = SLoc->getFile();
1823       Record.push_back(File.getIncludeLoc().getRawEncoding());
1824       Record.push_back(File.getFileCharacteristic()); // FIXME: stable encoding
1825       Record.push_back(File.hasLineDirectives());
1826 
1827       const SrcMgr::ContentCache *Content = File.getContentCache();
1828       if (Content->OrigEntry) {
1829         assert(Content->OrigEntry == Content->ContentsEntry &&
1830                "Writing to AST an overridden file is not supported");
1831 
1832         // The source location entry is a file. Emit input file ID.
1833         assert(InputFileIDs[Content->OrigEntry] != 0 && "Missed file entry");
1834         Record.push_back(InputFileIDs[Content->OrigEntry]);
1835 
1836         Record.push_back(File.NumCreatedFIDs);
1837 
1838         FileDeclIDsTy::iterator FDI = FileDeclIDs.find(FID);
1839         if (FDI != FileDeclIDs.end()) {
1840           Record.push_back(FDI->second->FirstDeclIndex);
1841           Record.push_back(FDI->second->DeclIDs.size());
1842         } else {
1843           Record.push_back(0);
1844           Record.push_back(0);
1845         }
1846 
1847         Stream.EmitRecordWithAbbrev(SLocFileAbbrv, Record);
1848 
1849         if (Content->BufferOverridden) {
1850           Record.clear();
1851           Record.push_back(SM_SLOC_BUFFER_BLOB);
1852           const llvm::MemoryBuffer *Buffer
1853             = Content->getBuffer(PP.getDiagnostics(), PP.getSourceManager());
1854           Stream.EmitRecordWithBlob(SLocBufferBlobAbbrv, Record,
1855                                     StringRef(Buffer->getBufferStart(),
1856                                               Buffer->getBufferSize() + 1));
1857         }
1858       } else {
1859         // The source location entry is a buffer. The blob associated
1860         // with this entry contains the contents of the buffer.
1861 
1862         // We add one to the size so that we capture the trailing NULL
1863         // that is required by llvm::MemoryBuffer::getMemBuffer (on
1864         // the reader side).
1865         const llvm::MemoryBuffer *Buffer
1866           = Content->getBuffer(PP.getDiagnostics(), PP.getSourceManager());
1867         const char *Name = Buffer->getBufferIdentifier();
1868         Stream.EmitRecordWithBlob(SLocBufferAbbrv, Record,
1869                                   StringRef(Name, strlen(Name) + 1));
1870         Record.clear();
1871         Record.push_back(SM_SLOC_BUFFER_BLOB);
1872         Stream.EmitRecordWithBlob(SLocBufferBlobAbbrv, Record,
1873                                   StringRef(Buffer->getBufferStart(),
1874                                                   Buffer->getBufferSize() + 1));
1875 
1876         if (strcmp(Name, "<built-in>") == 0) {
1877           PreloadSLocs.push_back(SLocEntryOffsets.size());
1878         }
1879       }
1880     } else {
1881       // The source location entry is a macro expansion.
1882       const SrcMgr::ExpansionInfo &Expansion = SLoc->getExpansion();
1883       Record.push_back(Expansion.getSpellingLoc().getRawEncoding());
1884       Record.push_back(Expansion.getExpansionLocStart().getRawEncoding());
1885       Record.push_back(Expansion.isMacroArgExpansion() ? 0
1886                              : Expansion.getExpansionLocEnd().getRawEncoding());
1887 
1888       // Compute the token length for this macro expansion.
1889       unsigned NextOffset = SourceMgr.getNextLocalOffset();
1890       if (I + 1 != N)
1891         NextOffset = SourceMgr.getLocalSLocEntry(I + 1).getOffset();
1892       Record.push_back(NextOffset - SLoc->getOffset() - 1);
1893       Stream.EmitRecordWithAbbrev(SLocExpansionAbbrv, Record);
1894     }
1895   }
1896 
1897   Stream.ExitBlock();
1898 
1899   if (SLocEntryOffsets.empty())
1900     return;
1901 
1902   // Write the source-location offsets table into the AST block. This
1903   // table is used for lazily loading source-location information.
1904   using namespace llvm;
1905   BitCodeAbbrev *Abbrev = new BitCodeAbbrev();
1906   Abbrev->Add(BitCodeAbbrevOp(SOURCE_LOCATION_OFFSETS));
1907   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 16)); // # of slocs
1908   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 16)); // total size
1909   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // offsets
1910   unsigned SLocOffsetsAbbrev = Stream.EmitAbbrev(Abbrev);
1911 
1912   Record.clear();
1913   Record.push_back(SOURCE_LOCATION_OFFSETS);
1914   Record.push_back(SLocEntryOffsets.size());
1915   Record.push_back(SourceMgr.getNextLocalOffset() - 1); // skip dummy
1916   Stream.EmitRecordWithBlob(SLocOffsetsAbbrev, Record, data(SLocEntryOffsets));
1917 
1918   // Write the source location entry preloads array, telling the AST
1919   // reader which source locations entries it should load eagerly.
1920   Stream.EmitRecord(SOURCE_LOCATION_PRELOADS, PreloadSLocs);
1921 
1922   // Write the line table. It depends on remapping working, so it must come
1923   // after the source location offsets.
1924   if (SourceMgr.hasLineTable()) {
1925     LineTableInfo &LineTable = SourceMgr.getLineTable();
1926 
1927     Record.clear();
1928     // Emit the file names.
1929     Record.push_back(LineTable.getNumFilenames());
1930     for (unsigned I = 0, N = LineTable.getNumFilenames(); I != N; ++I)
1931       AddPath(LineTable.getFilename(I), Record);
1932 
1933     // Emit the line entries
1934     for (LineTableInfo::iterator L = LineTable.begin(), LEnd = LineTable.end();
1935          L != LEnd; ++L) {
1936       // Only emit entries for local files.
1937       if (L->first.ID < 0)
1938         continue;
1939 
1940       // Emit the file ID
1941       Record.push_back(L->first.ID);
1942 
1943       // Emit the line entries
1944       Record.push_back(L->second.size());
1945       for (std::vector<LineEntry>::iterator LE = L->second.begin(),
1946                                          LEEnd = L->second.end();
1947            LE != LEEnd; ++LE) {
1948         Record.push_back(LE->FileOffset);
1949         Record.push_back(LE->LineNo);
1950         Record.push_back(LE->FilenameID);
1951         Record.push_back((unsigned)LE->FileKind);
1952         Record.push_back(LE->IncludeOffset);
1953       }
1954     }
1955     Stream.EmitRecord(SOURCE_MANAGER_LINE_TABLE, Record);
1956   }
1957 }
1958 
1959 //===----------------------------------------------------------------------===//
1960 // Preprocessor Serialization
1961 //===----------------------------------------------------------------------===//
1962 
1963 namespace {
1964 class ASTMacroTableTrait {
1965 public:
1966   typedef IdentID key_type;
1967   typedef key_type key_type_ref;
1968 
1969   struct Data {
1970     uint32_t MacroDirectivesOffset;
1971   };
1972 
1973   typedef Data data_type;
1974   typedef const data_type &data_type_ref;
1975   typedef unsigned hash_value_type;
1976   typedef unsigned offset_type;
1977 
1978   static hash_value_type ComputeHash(IdentID IdID) {
1979     return llvm::hash_value(IdID);
1980   }
1981 
1982   std::pair<unsigned,unsigned>
1983   static EmitKeyDataLength(raw_ostream& Out,
1984                            key_type_ref Key, data_type_ref Data) {
1985     unsigned KeyLen = 4; // IdentID.
1986     unsigned DataLen = 4; // MacroDirectivesOffset.
1987     return std::make_pair(KeyLen, DataLen);
1988   }
1989 
1990   static void EmitKey(raw_ostream& Out, key_type_ref Key, unsigned KeyLen) {
1991     using namespace llvm::support;
1992     endian::Writer<little>(Out).write<uint32_t>(Key);
1993   }
1994 
1995   static void EmitData(raw_ostream& Out, key_type_ref Key, data_type_ref Data,
1996                        unsigned) {
1997     using namespace llvm::support;
1998     endian::Writer<little>(Out).write<uint32_t>(Data.MacroDirectivesOffset);
1999   }
2000 };
2001 } // end anonymous namespace
2002 
2003 static int compareMacroDirectives(
2004     const std::pair<const IdentifierInfo *, MacroDirective *> *X,
2005     const std::pair<const IdentifierInfo *, MacroDirective *> *Y) {
2006   return X->first->getName().compare(Y->first->getName());
2007 }
2008 
2009 static bool shouldIgnoreMacro(MacroDirective *MD, bool IsModule,
2010                               const Preprocessor &PP) {
2011   if (MacroInfo *MI = MD->getMacroInfo())
2012     if (MI->isBuiltinMacro())
2013       return true;
2014 
2015   if (IsModule) {
2016     // Re-export any imported directives.
2017     if (MD->isImported())
2018       return false;
2019 
2020     SourceLocation Loc = MD->getLocation();
2021     if (Loc.isInvalid())
2022       return true;
2023     if (PP.getSourceManager().getFileID(Loc) == PP.getPredefinesFileID())
2024       return true;
2025   }
2026 
2027   return false;
2028 }
2029 
2030 /// \brief Writes the block containing the serialized form of the
2031 /// preprocessor.
2032 ///
2033 void ASTWriter::WritePreprocessor(const Preprocessor &PP, bool IsModule) {
2034   PreprocessingRecord *PPRec = PP.getPreprocessingRecord();
2035   if (PPRec)
2036     WritePreprocessorDetail(*PPRec);
2037 
2038   RecordData Record;
2039 
2040   // If the preprocessor __COUNTER__ value has been bumped, remember it.
2041   if (PP.getCounterValue() != 0) {
2042     Record.push_back(PP.getCounterValue());
2043     Stream.EmitRecord(PP_COUNTER_VALUE, Record);
2044     Record.clear();
2045   }
2046 
2047   // Enter the preprocessor block.
2048   Stream.EnterSubblock(PREPROCESSOR_BLOCK_ID, 3);
2049 
2050   // If the AST file contains __DATE__ or __TIME__ emit a warning about this.
2051   // FIXME: use diagnostics subsystem for localization etc.
2052   if (PP.SawDateOrTime())
2053     fprintf(stderr, "warning: precompiled header used __DATE__ or __TIME__.\n");
2054 
2055 
2056   // Loop over all the macro directives that are live at the end of the file,
2057   // emitting each to the PP section.
2058 
2059   // Construct the list of macro directives that need to be serialized.
2060   SmallVector<std::pair<const IdentifierInfo *, MacroDirective *>, 2>
2061     MacroDirectives;
2062   for (Preprocessor::macro_iterator
2063          I = PP.macro_begin(/*IncludeExternalMacros=*/false),
2064          E = PP.macro_end(/*IncludeExternalMacros=*/false);
2065        I != E; ++I) {
2066     MacroDirectives.push_back(std::make_pair(I->first, I->second));
2067   }
2068 
2069   // Sort the set of macro definitions that need to be serialized by the
2070   // name of the macro, to provide a stable ordering.
2071   llvm::array_pod_sort(MacroDirectives.begin(), MacroDirectives.end(),
2072                        &compareMacroDirectives);
2073 
2074   llvm::OnDiskChainedHashTableGenerator<ASTMacroTableTrait> Generator;
2075 
2076   // Emit the macro directives as a list and associate the offset with the
2077   // identifier they belong to.
2078   for (unsigned I = 0, N = MacroDirectives.size(); I != N; ++I) {
2079     const IdentifierInfo *Name = MacroDirectives[I].first;
2080     uint64_t MacroDirectiveOffset = Stream.GetCurrentBitNo();
2081     MacroDirective *MD = MacroDirectives[I].second;
2082 
2083     // If the macro or identifier need no updates, don't write the macro history
2084     // for this one.
2085     // FIXME: Chain the macro history instead of re-writing it.
2086     if (MD->isFromPCH() &&
2087         Name->isFromAST() && !Name->hasChangedSinceDeserialization())
2088       continue;
2089 
2090     // Emit the macro directives in reverse source order.
2091     for (; MD; MD = MD->getPrevious()) {
2092       if (shouldIgnoreMacro(MD, IsModule, PP))
2093         continue;
2094 
2095       AddSourceLocation(MD->getLocation(), Record);
2096       Record.push_back(MD->getKind());
2097       if (auto *DefMD = dyn_cast<DefMacroDirective>(MD)) {
2098         MacroID InfoID = getMacroRef(DefMD->getInfo(), Name);
2099         Record.push_back(InfoID);
2100         Record.push_back(DefMD->getOwningModuleID());
2101         Record.push_back(DefMD->isAmbiguous());
2102       } else if (auto *UndefMD = dyn_cast<UndefMacroDirective>(MD)) {
2103         Record.push_back(UndefMD->getOwningModuleID());
2104       } else {
2105         auto *VisMD = cast<VisibilityMacroDirective>(MD);
2106         Record.push_back(VisMD->isPublic());
2107       }
2108 
2109       if (MD->isImported()) {
2110         auto Overrides = MD->getOverriddenModules();
2111         Record.push_back(Overrides.size());
2112         Record.append(Overrides.begin(), Overrides.end());
2113       }
2114     }
2115     if (Record.empty())
2116       continue;
2117 
2118     Stream.EmitRecord(PP_MACRO_DIRECTIVE_HISTORY, Record);
2119     Record.clear();
2120 
2121     IdentMacroDirectivesOffsetMap[Name] = MacroDirectiveOffset;
2122 
2123     IdentID NameID = getIdentifierRef(Name);
2124     ASTMacroTableTrait::Data data;
2125     data.MacroDirectivesOffset = MacroDirectiveOffset;
2126     Generator.insert(NameID, data);
2127   }
2128 
2129   /// \brief Offsets of each of the macros into the bitstream, indexed by
2130   /// the local macro ID
2131   ///
2132   /// For each identifier that is associated with a macro, this map
2133   /// provides the offset into the bitstream where that macro is
2134   /// defined.
2135   std::vector<uint32_t> MacroOffsets;
2136 
2137   for (unsigned I = 0, N = MacroInfosToEmit.size(); I != N; ++I) {
2138     const IdentifierInfo *Name = MacroInfosToEmit[I].Name;
2139     MacroInfo *MI = MacroInfosToEmit[I].MI;
2140     MacroID ID = MacroInfosToEmit[I].ID;
2141 
2142     if (ID < FirstMacroID) {
2143       assert(0 && "Loaded MacroInfo entered MacroInfosToEmit ?");
2144       continue;
2145     }
2146 
2147     // Record the local offset of this macro.
2148     unsigned Index = ID - FirstMacroID;
2149     if (Index == MacroOffsets.size())
2150       MacroOffsets.push_back(Stream.GetCurrentBitNo());
2151     else {
2152       if (Index > MacroOffsets.size())
2153         MacroOffsets.resize(Index + 1);
2154 
2155       MacroOffsets[Index] = Stream.GetCurrentBitNo();
2156     }
2157 
2158     AddIdentifierRef(Name, Record);
2159     Record.push_back(inferSubmoduleIDFromLocation(MI->getDefinitionLoc()));
2160     AddSourceLocation(MI->getDefinitionLoc(), Record);
2161     AddSourceLocation(MI->getDefinitionEndLoc(), Record);
2162     Record.push_back(MI->isUsed());
2163     Record.push_back(MI->isUsedForHeaderGuard());
2164     unsigned Code;
2165     if (MI->isObjectLike()) {
2166       Code = PP_MACRO_OBJECT_LIKE;
2167     } else {
2168       Code = PP_MACRO_FUNCTION_LIKE;
2169 
2170       Record.push_back(MI->isC99Varargs());
2171       Record.push_back(MI->isGNUVarargs());
2172       Record.push_back(MI->hasCommaPasting());
2173       Record.push_back(MI->getNumArgs());
2174       for (MacroInfo::arg_iterator I = MI->arg_begin(), E = MI->arg_end();
2175            I != E; ++I)
2176         AddIdentifierRef(*I, Record);
2177     }
2178 
2179     // If we have a detailed preprocessing record, record the macro definition
2180     // ID that corresponds to this macro.
2181     if (PPRec)
2182       Record.push_back(MacroDefinitions[PPRec->findMacroDefinition(MI)]);
2183 
2184     Stream.EmitRecord(Code, Record);
2185     Record.clear();
2186 
2187     // Emit the tokens array.
2188     for (unsigned TokNo = 0, e = MI->getNumTokens(); TokNo != e; ++TokNo) {
2189       // Note that we know that the preprocessor does not have any annotation
2190       // tokens in it because they are created by the parser, and thus can't
2191       // be in a macro definition.
2192       const Token &Tok = MI->getReplacementToken(TokNo);
2193       AddToken(Tok, Record);
2194       Stream.EmitRecord(PP_TOKEN, Record);
2195       Record.clear();
2196     }
2197     ++NumMacros;
2198   }
2199 
2200   Stream.ExitBlock();
2201 
2202   // Create the on-disk hash table in a buffer.
2203   SmallString<4096> MacroTable;
2204   uint32_t BucketOffset;
2205   {
2206     using namespace llvm::support;
2207     llvm::raw_svector_ostream Out(MacroTable);
2208     // Make sure that no bucket is at offset 0
2209     endian::Writer<little>(Out).write<uint32_t>(0);
2210     BucketOffset = Generator.Emit(Out);
2211   }
2212 
2213   // Write the macro table
2214   using namespace llvm;
2215   BitCodeAbbrev *Abbrev = new BitCodeAbbrev();
2216   Abbrev->Add(BitCodeAbbrevOp(MACRO_TABLE));
2217   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
2218   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
2219   unsigned MacroTableAbbrev = Stream.EmitAbbrev(Abbrev);
2220 
2221   Record.push_back(MACRO_TABLE);
2222   Record.push_back(BucketOffset);
2223   Stream.EmitRecordWithBlob(MacroTableAbbrev, Record, MacroTable.str());
2224   Record.clear();
2225 
2226   // Write the offsets table for macro IDs.
2227   using namespace llvm;
2228   Abbrev = new BitCodeAbbrev();
2229   Abbrev->Add(BitCodeAbbrevOp(MACRO_OFFSET));
2230   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // # of macros
2231   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // first ID
2232   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
2233 
2234   unsigned MacroOffsetAbbrev = Stream.EmitAbbrev(Abbrev);
2235   Record.clear();
2236   Record.push_back(MACRO_OFFSET);
2237   Record.push_back(MacroOffsets.size());
2238   Record.push_back(FirstMacroID - NUM_PREDEF_MACRO_IDS);
2239   Stream.EmitRecordWithBlob(MacroOffsetAbbrev, Record,
2240                             data(MacroOffsets));
2241 }
2242 
2243 void ASTWriter::WritePreprocessorDetail(PreprocessingRecord &PPRec) {
2244   if (PPRec.local_begin() == PPRec.local_end())
2245     return;
2246 
2247   SmallVector<PPEntityOffset, 64> PreprocessedEntityOffsets;
2248 
2249   // Enter the preprocessor block.
2250   Stream.EnterSubblock(PREPROCESSOR_DETAIL_BLOCK_ID, 3);
2251 
2252   // If the preprocessor has a preprocessing record, emit it.
2253   unsigned NumPreprocessingRecords = 0;
2254   using namespace llvm;
2255 
2256   // Set up the abbreviation for
2257   unsigned InclusionAbbrev = 0;
2258   {
2259     BitCodeAbbrev *Abbrev = new BitCodeAbbrev();
2260     Abbrev->Add(BitCodeAbbrevOp(PPD_INCLUSION_DIRECTIVE));
2261     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // filename length
2262     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // in quotes
2263     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2)); // kind
2264     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // imported module
2265     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
2266     InclusionAbbrev = Stream.EmitAbbrev(Abbrev);
2267   }
2268 
2269   unsigned FirstPreprocessorEntityID
2270     = (Chain ? PPRec.getNumLoadedPreprocessedEntities() : 0)
2271     + NUM_PREDEF_PP_ENTITY_IDS;
2272   unsigned NextPreprocessorEntityID = FirstPreprocessorEntityID;
2273   RecordData Record;
2274   for (PreprocessingRecord::iterator E = PPRec.local_begin(),
2275                                   EEnd = PPRec.local_end();
2276        E != EEnd;
2277        (void)++E, ++NumPreprocessingRecords, ++NextPreprocessorEntityID) {
2278     Record.clear();
2279 
2280     PreprocessedEntityOffsets.push_back(PPEntityOffset((*E)->getSourceRange(),
2281                                                      Stream.GetCurrentBitNo()));
2282 
2283     if (MacroDefinition *MD = dyn_cast<MacroDefinition>(*E)) {
2284       // Record this macro definition's ID.
2285       MacroDefinitions[MD] = NextPreprocessorEntityID;
2286 
2287       AddIdentifierRef(MD->getName(), Record);
2288       Stream.EmitRecord(PPD_MACRO_DEFINITION, Record);
2289       continue;
2290     }
2291 
2292     if (MacroExpansion *ME = dyn_cast<MacroExpansion>(*E)) {
2293       Record.push_back(ME->isBuiltinMacro());
2294       if (ME->isBuiltinMacro())
2295         AddIdentifierRef(ME->getName(), Record);
2296       else
2297         Record.push_back(MacroDefinitions[ME->getDefinition()]);
2298       Stream.EmitRecord(PPD_MACRO_EXPANSION, Record);
2299       continue;
2300     }
2301 
2302     if (InclusionDirective *ID = dyn_cast<InclusionDirective>(*E)) {
2303       Record.push_back(PPD_INCLUSION_DIRECTIVE);
2304       Record.push_back(ID->getFileName().size());
2305       Record.push_back(ID->wasInQuotes());
2306       Record.push_back(static_cast<unsigned>(ID->getKind()));
2307       Record.push_back(ID->importedModule());
2308       SmallString<64> Buffer;
2309       Buffer += ID->getFileName();
2310       // Check that the FileEntry is not null because it was not resolved and
2311       // we create a PCH even with compiler errors.
2312       if (ID->getFile())
2313         Buffer += ID->getFile()->getName();
2314       Stream.EmitRecordWithBlob(InclusionAbbrev, Record, Buffer);
2315       continue;
2316     }
2317 
2318     llvm_unreachable("Unhandled PreprocessedEntity in ASTWriter");
2319   }
2320   Stream.ExitBlock();
2321 
2322   // Write the offsets table for the preprocessing record.
2323   if (NumPreprocessingRecords > 0) {
2324     assert(PreprocessedEntityOffsets.size() == NumPreprocessingRecords);
2325 
2326     // Write the offsets table for identifier IDs.
2327     using namespace llvm;
2328     BitCodeAbbrev *Abbrev = new BitCodeAbbrev();
2329     Abbrev->Add(BitCodeAbbrevOp(PPD_ENTITIES_OFFSETS));
2330     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // first pp entity
2331     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
2332     unsigned PPEOffsetAbbrev = Stream.EmitAbbrev(Abbrev);
2333 
2334     Record.clear();
2335     Record.push_back(PPD_ENTITIES_OFFSETS);
2336     Record.push_back(FirstPreprocessorEntityID - NUM_PREDEF_PP_ENTITY_IDS);
2337     Stream.EmitRecordWithBlob(PPEOffsetAbbrev, Record,
2338                               data(PreprocessedEntityOffsets));
2339   }
2340 }
2341 
2342 unsigned ASTWriter::getSubmoduleID(Module *Mod) {
2343   llvm::DenseMap<Module *, unsigned>::iterator Known = SubmoduleIDs.find(Mod);
2344   if (Known != SubmoduleIDs.end())
2345     return Known->second;
2346 
2347   return SubmoduleIDs[Mod] = NextSubmoduleID++;
2348 }
2349 
2350 unsigned ASTWriter::getExistingSubmoduleID(Module *Mod) const {
2351   if (!Mod)
2352     return 0;
2353 
2354   llvm::DenseMap<Module *, unsigned>::const_iterator
2355     Known = SubmoduleIDs.find(Mod);
2356   if (Known != SubmoduleIDs.end())
2357     return Known->second;
2358 
2359   return 0;
2360 }
2361 
2362 /// \brief Compute the number of modules within the given tree (including the
2363 /// given module).
2364 static unsigned getNumberOfModules(Module *Mod) {
2365   unsigned ChildModules = 0;
2366   for (Module::submodule_iterator Sub = Mod->submodule_begin(),
2367                                SubEnd = Mod->submodule_end();
2368        Sub != SubEnd; ++Sub)
2369     ChildModules += getNumberOfModules(*Sub);
2370 
2371   return ChildModules + 1;
2372 }
2373 
2374 void ASTWriter::WriteSubmodules(Module *WritingModule) {
2375   // Determine the dependencies of our module and each of it's submodules.
2376   // FIXME: This feels like it belongs somewhere else, but there are no
2377   // other consumers of this information.
2378   SourceManager &SrcMgr = PP->getSourceManager();
2379   ModuleMap &ModMap = PP->getHeaderSearchInfo().getModuleMap();
2380   for (const auto *I : Context->local_imports()) {
2381     if (Module *ImportedFrom
2382           = ModMap.inferModuleFromLocation(FullSourceLoc(I->getLocation(),
2383                                                          SrcMgr))) {
2384       ImportedFrom->Imports.push_back(I->getImportedModule());
2385     }
2386   }
2387 
2388   // Enter the submodule description block.
2389   Stream.EnterSubblock(SUBMODULE_BLOCK_ID, /*bits for abbreviations*/5);
2390 
2391   // Write the abbreviations needed for the submodules block.
2392   using namespace llvm;
2393   BitCodeAbbrev *Abbrev = new BitCodeAbbrev();
2394   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_DEFINITION));
2395   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // ID
2396   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Parent
2397   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsFramework
2398   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsExplicit
2399   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsSystem
2400   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsExternC
2401   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // InferSubmodules...
2402   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // InferExplicit...
2403   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // InferExportWild...
2404   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // ConfigMacrosExh...
2405   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Name
2406   unsigned DefinitionAbbrev = Stream.EmitAbbrev(Abbrev);
2407 
2408   Abbrev = new BitCodeAbbrev();
2409   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_UMBRELLA_HEADER));
2410   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Name
2411   unsigned UmbrellaAbbrev = Stream.EmitAbbrev(Abbrev);
2412 
2413   Abbrev = new BitCodeAbbrev();
2414   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_HEADER));
2415   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Name
2416   unsigned HeaderAbbrev = Stream.EmitAbbrev(Abbrev);
2417 
2418   Abbrev = new BitCodeAbbrev();
2419   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_TOPHEADER));
2420   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Name
2421   unsigned TopHeaderAbbrev = Stream.EmitAbbrev(Abbrev);
2422 
2423   Abbrev = new BitCodeAbbrev();
2424   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_UMBRELLA_DIR));
2425   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Name
2426   unsigned UmbrellaDirAbbrev = Stream.EmitAbbrev(Abbrev);
2427 
2428   Abbrev = new BitCodeAbbrev();
2429   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_REQUIRES));
2430   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // State
2431   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));     // Feature
2432   unsigned RequiresAbbrev = Stream.EmitAbbrev(Abbrev);
2433 
2434   Abbrev = new BitCodeAbbrev();
2435   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_EXCLUDED_HEADER));
2436   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Name
2437   unsigned ExcludedHeaderAbbrev = Stream.EmitAbbrev(Abbrev);
2438 
2439   Abbrev = new BitCodeAbbrev();
2440   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_TEXTUAL_HEADER));
2441   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Name
2442   unsigned TextualHeaderAbbrev = Stream.EmitAbbrev(Abbrev);
2443 
2444   Abbrev = new BitCodeAbbrev();
2445   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_PRIVATE_HEADER));
2446   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Name
2447   unsigned PrivateHeaderAbbrev = Stream.EmitAbbrev(Abbrev);
2448 
2449   Abbrev = new BitCodeAbbrev();
2450   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_PRIVATE_TEXTUAL_HEADER));
2451   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Name
2452   unsigned PrivateTextualHeaderAbbrev = Stream.EmitAbbrev(Abbrev);
2453 
2454   Abbrev = new BitCodeAbbrev();
2455   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_LINK_LIBRARY));
2456   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsFramework
2457   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));     // Name
2458   unsigned LinkLibraryAbbrev = Stream.EmitAbbrev(Abbrev);
2459 
2460   Abbrev = new BitCodeAbbrev();
2461   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_CONFIG_MACRO));
2462   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));    // Macro name
2463   unsigned ConfigMacroAbbrev = Stream.EmitAbbrev(Abbrev);
2464 
2465   Abbrev = new BitCodeAbbrev();
2466   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_CONFLICT));
2467   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));  // Other module
2468   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));    // Message
2469   unsigned ConflictAbbrev = Stream.EmitAbbrev(Abbrev);
2470 
2471   // Write the submodule metadata block.
2472   RecordData Record;
2473   Record.push_back(getNumberOfModules(WritingModule));
2474   Record.push_back(FirstSubmoduleID - NUM_PREDEF_SUBMODULE_IDS);
2475   Stream.EmitRecord(SUBMODULE_METADATA, Record);
2476 
2477   // Write all of the submodules.
2478   std::queue<Module *> Q;
2479   Q.push(WritingModule);
2480   while (!Q.empty()) {
2481     Module *Mod = Q.front();
2482     Q.pop();
2483     unsigned ID = getSubmoduleID(Mod);
2484 
2485     // Emit the definition of the block.
2486     Record.clear();
2487     Record.push_back(SUBMODULE_DEFINITION);
2488     Record.push_back(ID);
2489     if (Mod->Parent) {
2490       assert(SubmoduleIDs[Mod->Parent] && "Submodule parent not written?");
2491       Record.push_back(SubmoduleIDs[Mod->Parent]);
2492     } else {
2493       Record.push_back(0);
2494     }
2495     Record.push_back(Mod->IsFramework);
2496     Record.push_back(Mod->IsExplicit);
2497     Record.push_back(Mod->IsSystem);
2498     Record.push_back(Mod->IsExternC);
2499     Record.push_back(Mod->InferSubmodules);
2500     Record.push_back(Mod->InferExplicitSubmodules);
2501     Record.push_back(Mod->InferExportWildcard);
2502     Record.push_back(Mod->ConfigMacrosExhaustive);
2503     Stream.EmitRecordWithBlob(DefinitionAbbrev, Record, Mod->Name);
2504 
2505     // Emit the requirements.
2506     for (unsigned I = 0, N = Mod->Requirements.size(); I != N; ++I) {
2507       Record.clear();
2508       Record.push_back(SUBMODULE_REQUIRES);
2509       Record.push_back(Mod->Requirements[I].second);
2510       Stream.EmitRecordWithBlob(RequiresAbbrev, Record,
2511                                 Mod->Requirements[I].first);
2512     }
2513 
2514     // Emit the umbrella header, if there is one.
2515     if (const FileEntry *UmbrellaHeader = Mod->getUmbrellaHeader()) {
2516       Record.clear();
2517       Record.push_back(SUBMODULE_UMBRELLA_HEADER);
2518       Stream.EmitRecordWithBlob(UmbrellaAbbrev, Record,
2519                                 UmbrellaHeader->getName());
2520     } else if (const DirectoryEntry *UmbrellaDir = Mod->getUmbrellaDir()) {
2521       Record.clear();
2522       Record.push_back(SUBMODULE_UMBRELLA_DIR);
2523       Stream.EmitRecordWithBlob(UmbrellaDirAbbrev, Record,
2524                                 UmbrellaDir->getName());
2525     }
2526 
2527     // Emit the headers.
2528     struct {
2529       unsigned RecordKind;
2530       unsigned Abbrev;
2531       Module::HeaderKind HeaderKind;
2532     } HeaderLists[] = {
2533       {SUBMODULE_HEADER, HeaderAbbrev, Module::HK_Normal},
2534       {SUBMODULE_TEXTUAL_HEADER, TextualHeaderAbbrev, Module::HK_Textual},
2535       {SUBMODULE_PRIVATE_HEADER, PrivateHeaderAbbrev, Module::HK_Private},
2536       {SUBMODULE_PRIVATE_TEXTUAL_HEADER, PrivateTextualHeaderAbbrev,
2537         Module::HK_PrivateTextual},
2538       {SUBMODULE_EXCLUDED_HEADER, ExcludedHeaderAbbrev, Module::HK_Excluded}
2539     };
2540     for (auto &HL : HeaderLists) {
2541       Record.clear();
2542       Record.push_back(HL.RecordKind);
2543       for (auto &H : Mod->Headers[HL.HeaderKind])
2544         Stream.EmitRecordWithBlob(HL.Abbrev, Record, H.NameAsWritten);
2545     }
2546 
2547     // Emit the top headers.
2548     {
2549       auto TopHeaders = Mod->getTopHeaders(PP->getFileManager());
2550       Record.clear();
2551       Record.push_back(SUBMODULE_TOPHEADER);
2552       for (auto *H : TopHeaders)
2553         Stream.EmitRecordWithBlob(TopHeaderAbbrev, Record, H->getName());
2554     }
2555 
2556     // Emit the imports.
2557     if (!Mod->Imports.empty()) {
2558       Record.clear();
2559       for (unsigned I = 0, N = Mod->Imports.size(); I != N; ++I) {
2560         unsigned ImportedID = getSubmoduleID(Mod->Imports[I]);
2561         assert(ImportedID && "Unknown submodule!");
2562         Record.push_back(ImportedID);
2563       }
2564       Stream.EmitRecord(SUBMODULE_IMPORTS, Record);
2565     }
2566 
2567     // Emit the exports.
2568     if (!Mod->Exports.empty()) {
2569       Record.clear();
2570       for (unsigned I = 0, N = Mod->Exports.size(); I != N; ++I) {
2571         if (Module *Exported = Mod->Exports[I].getPointer()) {
2572           unsigned ExportedID = SubmoduleIDs[Exported];
2573           assert(ExportedID > 0 && "Unknown submodule ID?");
2574           Record.push_back(ExportedID);
2575         } else {
2576           Record.push_back(0);
2577         }
2578 
2579         Record.push_back(Mod->Exports[I].getInt());
2580       }
2581       Stream.EmitRecord(SUBMODULE_EXPORTS, Record);
2582     }
2583 
2584     //FIXME: How do we emit the 'use'd modules?  They may not be submodules.
2585     // Might be unnecessary as use declarations are only used to build the
2586     // module itself.
2587 
2588     // Emit the link libraries.
2589     for (unsigned I = 0, N = Mod->LinkLibraries.size(); I != N; ++I) {
2590       Record.clear();
2591       Record.push_back(SUBMODULE_LINK_LIBRARY);
2592       Record.push_back(Mod->LinkLibraries[I].IsFramework);
2593       Stream.EmitRecordWithBlob(LinkLibraryAbbrev, Record,
2594                                 Mod->LinkLibraries[I].Library);
2595     }
2596 
2597     // Emit the conflicts.
2598     for (unsigned I = 0, N = Mod->Conflicts.size(); I != N; ++I) {
2599       Record.clear();
2600       Record.push_back(SUBMODULE_CONFLICT);
2601       unsigned OtherID = getSubmoduleID(Mod->Conflicts[I].Other);
2602       assert(OtherID && "Unknown submodule!");
2603       Record.push_back(OtherID);
2604       Stream.EmitRecordWithBlob(ConflictAbbrev, Record,
2605                                 Mod->Conflicts[I].Message);
2606     }
2607 
2608     // Emit the configuration macros.
2609     for (unsigned I = 0, N =  Mod->ConfigMacros.size(); I != N; ++I) {
2610       Record.clear();
2611       Record.push_back(SUBMODULE_CONFIG_MACRO);
2612       Stream.EmitRecordWithBlob(ConfigMacroAbbrev, Record,
2613                                 Mod->ConfigMacros[I]);
2614     }
2615 
2616     // Queue up the submodules of this module.
2617     for (Module::submodule_iterator Sub = Mod->submodule_begin(),
2618                                  SubEnd = Mod->submodule_end();
2619          Sub != SubEnd; ++Sub)
2620       Q.push(*Sub);
2621   }
2622 
2623   Stream.ExitBlock();
2624 
2625   assert((NextSubmoduleID - FirstSubmoduleID
2626             == getNumberOfModules(WritingModule)) && "Wrong # of submodules");
2627 }
2628 
2629 serialization::SubmoduleID
2630 ASTWriter::inferSubmoduleIDFromLocation(SourceLocation Loc) {
2631   if (Loc.isInvalid() || !WritingModule)
2632     return 0; // No submodule
2633 
2634   // Find the module that owns this location.
2635   ModuleMap &ModMap = PP->getHeaderSearchInfo().getModuleMap();
2636   Module *OwningMod
2637     = ModMap.inferModuleFromLocation(FullSourceLoc(Loc,PP->getSourceManager()));
2638   if (!OwningMod)
2639     return 0;
2640 
2641   // Check whether this submodule is part of our own module.
2642   if (WritingModule != OwningMod && !OwningMod->isSubModuleOf(WritingModule))
2643     return 0;
2644 
2645   return getSubmoduleID(OwningMod);
2646 }
2647 
2648 void ASTWriter::WritePragmaDiagnosticMappings(const DiagnosticsEngine &Diag,
2649                                               bool isModule) {
2650   // Make sure set diagnostic pragmas don't affect the translation unit that
2651   // imports the module.
2652   // FIXME: Make diagnostic pragma sections work properly with modules.
2653   if (isModule)
2654     return;
2655 
2656   llvm::SmallDenseMap<const DiagnosticsEngine::DiagState *, unsigned, 64>
2657       DiagStateIDMap;
2658   unsigned CurrID = 0;
2659   DiagStateIDMap[&Diag.DiagStates.front()] = ++CurrID; // the command-line one.
2660   RecordData Record;
2661   for (DiagnosticsEngine::DiagStatePointsTy::const_iterator
2662          I = Diag.DiagStatePoints.begin(), E = Diag.DiagStatePoints.end();
2663          I != E; ++I) {
2664     const DiagnosticsEngine::DiagStatePoint &point = *I;
2665     if (point.Loc.isInvalid())
2666       continue;
2667 
2668     Record.push_back(point.Loc.getRawEncoding());
2669     unsigned &DiagStateID = DiagStateIDMap[point.State];
2670     Record.push_back(DiagStateID);
2671 
2672     if (DiagStateID == 0) {
2673       DiagStateID = ++CurrID;
2674       for (DiagnosticsEngine::DiagState::const_iterator
2675              I = point.State->begin(), E = point.State->end(); I != E; ++I) {
2676         if (I->second.isPragma()) {
2677           Record.push_back(I->first);
2678           Record.push_back((unsigned)I->second.getSeverity());
2679         }
2680       }
2681       Record.push_back(-1); // mark the end of the diag/map pairs for this
2682                             // location.
2683     }
2684   }
2685 
2686   if (!Record.empty())
2687     Stream.EmitRecord(DIAG_PRAGMA_MAPPINGS, Record);
2688 }
2689 
2690 void ASTWriter::WriteCXXBaseSpecifiersOffsets() {
2691   if (CXXBaseSpecifiersOffsets.empty())
2692     return;
2693 
2694   RecordData Record;
2695 
2696   // Create a blob abbreviation for the C++ base specifiers offsets.
2697   using namespace llvm;
2698 
2699   BitCodeAbbrev *Abbrev = new BitCodeAbbrev();
2700   Abbrev->Add(BitCodeAbbrevOp(CXX_BASE_SPECIFIER_OFFSETS));
2701   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // size
2702   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
2703   unsigned BaseSpecifierOffsetAbbrev = Stream.EmitAbbrev(Abbrev);
2704 
2705   // Write the base specifier offsets table.
2706   Record.clear();
2707   Record.push_back(CXX_BASE_SPECIFIER_OFFSETS);
2708   Record.push_back(CXXBaseSpecifiersOffsets.size());
2709   Stream.EmitRecordWithBlob(BaseSpecifierOffsetAbbrev, Record,
2710                             data(CXXBaseSpecifiersOffsets));
2711 }
2712 
2713 //===----------------------------------------------------------------------===//
2714 // Type Serialization
2715 //===----------------------------------------------------------------------===//
2716 
2717 /// \brief Write the representation of a type to the AST stream.
2718 void ASTWriter::WriteType(QualType T) {
2719   TypeIdx &Idx = TypeIdxs[T];
2720   if (Idx.getIndex() == 0) // we haven't seen this type before.
2721     Idx = TypeIdx(NextTypeID++);
2722 
2723   assert(Idx.getIndex() >= FirstTypeID && "Re-writing a type from a prior AST");
2724 
2725   // Record the offset for this type.
2726   unsigned Index = Idx.getIndex() - FirstTypeID;
2727   if (TypeOffsets.size() == Index)
2728     TypeOffsets.push_back(Stream.GetCurrentBitNo());
2729   else if (TypeOffsets.size() < Index) {
2730     TypeOffsets.resize(Index + 1);
2731     TypeOffsets[Index] = Stream.GetCurrentBitNo();
2732   }
2733 
2734   RecordData Record;
2735 
2736   // Emit the type's representation.
2737   ASTTypeWriter W(*this, Record);
2738   W.AbbrevToUse = 0;
2739 
2740   if (T.hasLocalNonFastQualifiers()) {
2741     Qualifiers Qs = T.getLocalQualifiers();
2742     AddTypeRef(T.getLocalUnqualifiedType(), Record);
2743     Record.push_back(Qs.getAsOpaqueValue());
2744     W.Code = TYPE_EXT_QUAL;
2745     W.AbbrevToUse = TypeExtQualAbbrev;
2746   } else {
2747     switch (T->getTypeClass()) {
2748       // For all of the concrete, non-dependent types, call the
2749       // appropriate visitor function.
2750 #define TYPE(Class, Base) \
2751     case Type::Class: W.Visit##Class##Type(cast<Class##Type>(T)); break;
2752 #define ABSTRACT_TYPE(Class, Base)
2753 #include "clang/AST/TypeNodes.def"
2754     }
2755   }
2756 
2757   // Emit the serialized record.
2758   Stream.EmitRecord(W.Code, Record, W.AbbrevToUse);
2759 
2760   // Flush any expressions that were written as part of this type.
2761   FlushStmts();
2762 }
2763 
2764 //===----------------------------------------------------------------------===//
2765 // Declaration Serialization
2766 //===----------------------------------------------------------------------===//
2767 
2768 /// \brief Write the block containing all of the declaration IDs
2769 /// lexically declared within the given DeclContext.
2770 ///
2771 /// \returns the offset of the DECL_CONTEXT_LEXICAL block within the
2772 /// bistream, or 0 if no block was written.
2773 uint64_t ASTWriter::WriteDeclContextLexicalBlock(ASTContext &Context,
2774                                                  DeclContext *DC) {
2775   if (DC->decls_empty())
2776     return 0;
2777 
2778   uint64_t Offset = Stream.GetCurrentBitNo();
2779   RecordData Record;
2780   Record.push_back(DECL_CONTEXT_LEXICAL);
2781   SmallVector<KindDeclIDPair, 64> Decls;
2782   for (const auto *D : DC->decls())
2783     Decls.push_back(std::make_pair(D->getKind(), GetDeclRef(D)));
2784 
2785   ++NumLexicalDeclContexts;
2786   Stream.EmitRecordWithBlob(DeclContextLexicalAbbrev, Record, data(Decls));
2787   return Offset;
2788 }
2789 
2790 void ASTWriter::WriteTypeDeclOffsets() {
2791   using namespace llvm;
2792   RecordData Record;
2793 
2794   // Write the type offsets array
2795   BitCodeAbbrev *Abbrev = new BitCodeAbbrev();
2796   Abbrev->Add(BitCodeAbbrevOp(TYPE_OFFSET));
2797   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // # of types
2798   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // base type index
2799   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // types block
2800   unsigned TypeOffsetAbbrev = Stream.EmitAbbrev(Abbrev);
2801   Record.clear();
2802   Record.push_back(TYPE_OFFSET);
2803   Record.push_back(TypeOffsets.size());
2804   Record.push_back(FirstTypeID - NUM_PREDEF_TYPE_IDS);
2805   Stream.EmitRecordWithBlob(TypeOffsetAbbrev, Record, data(TypeOffsets));
2806 
2807   // Write the declaration offsets array
2808   Abbrev = new BitCodeAbbrev();
2809   Abbrev->Add(BitCodeAbbrevOp(DECL_OFFSET));
2810   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // # of declarations
2811   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // base decl ID
2812   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // declarations block
2813   unsigned DeclOffsetAbbrev = Stream.EmitAbbrev(Abbrev);
2814   Record.clear();
2815   Record.push_back(DECL_OFFSET);
2816   Record.push_back(DeclOffsets.size());
2817   Record.push_back(FirstDeclID - NUM_PREDEF_DECL_IDS);
2818   Stream.EmitRecordWithBlob(DeclOffsetAbbrev, Record, data(DeclOffsets));
2819 }
2820 
2821 void ASTWriter::WriteFileDeclIDsMap() {
2822   using namespace llvm;
2823   RecordData Record;
2824 
2825   // Join the vectors of DeclIDs from all files.
2826   SmallVector<DeclID, 256> FileSortedIDs;
2827   for (FileDeclIDsTy::iterator
2828          FI = FileDeclIDs.begin(), FE = FileDeclIDs.end(); FI != FE; ++FI) {
2829     DeclIDInFileInfo &Info = *FI->second;
2830     Info.FirstDeclIndex = FileSortedIDs.size();
2831     for (LocDeclIDsTy::iterator
2832            DI = Info.DeclIDs.begin(), DE = Info.DeclIDs.end(); DI != DE; ++DI)
2833       FileSortedIDs.push_back(DI->second);
2834   }
2835 
2836   BitCodeAbbrev *Abbrev = new BitCodeAbbrev();
2837   Abbrev->Add(BitCodeAbbrevOp(FILE_SORTED_DECLS));
2838   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
2839   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
2840   unsigned AbbrevCode = Stream.EmitAbbrev(Abbrev);
2841   Record.push_back(FILE_SORTED_DECLS);
2842   Record.push_back(FileSortedIDs.size());
2843   Stream.EmitRecordWithBlob(AbbrevCode, Record, data(FileSortedIDs));
2844 }
2845 
2846 void ASTWriter::WriteComments() {
2847   Stream.EnterSubblock(COMMENTS_BLOCK_ID, 3);
2848   ArrayRef<RawComment *> RawComments = Context->Comments.getComments();
2849   RecordData Record;
2850   for (ArrayRef<RawComment *>::iterator I = RawComments.begin(),
2851                                         E = RawComments.end();
2852        I != E; ++I) {
2853     Record.clear();
2854     AddSourceRange((*I)->getSourceRange(), Record);
2855     Record.push_back((*I)->getKind());
2856     Record.push_back((*I)->isTrailingComment());
2857     Record.push_back((*I)->isAlmostTrailingComment());
2858     Stream.EmitRecord(COMMENTS_RAW_COMMENT, Record);
2859   }
2860   Stream.ExitBlock();
2861 }
2862 
2863 //===----------------------------------------------------------------------===//
2864 // Global Method Pool and Selector Serialization
2865 //===----------------------------------------------------------------------===//
2866 
2867 namespace {
2868 // Trait used for the on-disk hash table used in the method pool.
2869 class ASTMethodPoolTrait {
2870   ASTWriter &Writer;
2871 
2872 public:
2873   typedef Selector key_type;
2874   typedef key_type key_type_ref;
2875 
2876   struct data_type {
2877     SelectorID ID;
2878     ObjCMethodList Instance, Factory;
2879   };
2880   typedef const data_type& data_type_ref;
2881 
2882   typedef unsigned hash_value_type;
2883   typedef unsigned offset_type;
2884 
2885   explicit ASTMethodPoolTrait(ASTWriter &Writer) : Writer(Writer) { }
2886 
2887   static hash_value_type ComputeHash(Selector Sel) {
2888     return serialization::ComputeHash(Sel);
2889   }
2890 
2891   std::pair<unsigned,unsigned>
2892     EmitKeyDataLength(raw_ostream& Out, Selector Sel,
2893                       data_type_ref Methods) {
2894     using namespace llvm::support;
2895     endian::Writer<little> LE(Out);
2896     unsigned KeyLen = 2 + (Sel.getNumArgs()? Sel.getNumArgs() * 4 : 4);
2897     LE.write<uint16_t>(KeyLen);
2898     unsigned DataLen = 4 + 2 + 2; // 2 bytes for each of the method counts
2899     for (const ObjCMethodList *Method = &Methods.Instance; Method;
2900          Method = Method->getNext())
2901       if (Method->getMethod())
2902         DataLen += 4;
2903     for (const ObjCMethodList *Method = &Methods.Factory; Method;
2904          Method = Method->getNext())
2905       if (Method->getMethod())
2906         DataLen += 4;
2907     LE.write<uint16_t>(DataLen);
2908     return std::make_pair(KeyLen, DataLen);
2909   }
2910 
2911   void EmitKey(raw_ostream& Out, Selector Sel, unsigned) {
2912     using namespace llvm::support;
2913     endian::Writer<little> LE(Out);
2914     uint64_t Start = Out.tell();
2915     assert((Start >> 32) == 0 && "Selector key offset too large");
2916     Writer.SetSelectorOffset(Sel, Start);
2917     unsigned N = Sel.getNumArgs();
2918     LE.write<uint16_t>(N);
2919     if (N == 0)
2920       N = 1;
2921     for (unsigned I = 0; I != N; ++I)
2922       LE.write<uint32_t>(
2923           Writer.getIdentifierRef(Sel.getIdentifierInfoForSlot(I)));
2924   }
2925 
2926   void EmitData(raw_ostream& Out, key_type_ref,
2927                 data_type_ref Methods, unsigned DataLen) {
2928     using namespace llvm::support;
2929     endian::Writer<little> LE(Out);
2930     uint64_t Start = Out.tell(); (void)Start;
2931     LE.write<uint32_t>(Methods.ID);
2932     unsigned NumInstanceMethods = 0;
2933     for (const ObjCMethodList *Method = &Methods.Instance; Method;
2934          Method = Method->getNext())
2935       if (Method->getMethod())
2936         ++NumInstanceMethods;
2937 
2938     unsigned NumFactoryMethods = 0;
2939     for (const ObjCMethodList *Method = &Methods.Factory; Method;
2940          Method = Method->getNext())
2941       if (Method->getMethod())
2942         ++NumFactoryMethods;
2943 
2944     unsigned InstanceBits = Methods.Instance.getBits();
2945     assert(InstanceBits < 4);
2946     unsigned InstanceHasMoreThanOneDeclBit =
2947         Methods.Instance.hasMoreThanOneDecl();
2948     unsigned FullInstanceBits = (NumInstanceMethods << 3) |
2949                                 (InstanceHasMoreThanOneDeclBit << 2) |
2950                                 InstanceBits;
2951     unsigned FactoryBits = Methods.Factory.getBits();
2952     assert(FactoryBits < 4);
2953     unsigned FactoryHasMoreThanOneDeclBit =
2954         Methods.Factory.hasMoreThanOneDecl();
2955     unsigned FullFactoryBits = (NumFactoryMethods << 3) |
2956                                (FactoryHasMoreThanOneDeclBit << 2) |
2957                                FactoryBits;
2958     LE.write<uint16_t>(FullInstanceBits);
2959     LE.write<uint16_t>(FullFactoryBits);
2960     for (const ObjCMethodList *Method = &Methods.Instance; Method;
2961          Method = Method->getNext())
2962       if (Method->getMethod())
2963         LE.write<uint32_t>(Writer.getDeclID(Method->getMethod()));
2964     for (const ObjCMethodList *Method = &Methods.Factory; Method;
2965          Method = Method->getNext())
2966       if (Method->getMethod())
2967         LE.write<uint32_t>(Writer.getDeclID(Method->getMethod()));
2968 
2969     assert(Out.tell() - Start == DataLen && "Data length is wrong");
2970   }
2971 };
2972 } // end anonymous namespace
2973 
2974 /// \brief Write ObjC data: selectors and the method pool.
2975 ///
2976 /// The method pool contains both instance and factory methods, stored
2977 /// in an on-disk hash table indexed by the selector. The hash table also
2978 /// contains an empty entry for every other selector known to Sema.
2979 void ASTWriter::WriteSelectors(Sema &SemaRef) {
2980   using namespace llvm;
2981 
2982   // Do we have to do anything at all?
2983   if (SemaRef.MethodPool.empty() && SelectorIDs.empty())
2984     return;
2985   unsigned NumTableEntries = 0;
2986   // Create and write out the blob that contains selectors and the method pool.
2987   {
2988     llvm::OnDiskChainedHashTableGenerator<ASTMethodPoolTrait> Generator;
2989     ASTMethodPoolTrait Trait(*this);
2990 
2991     // Create the on-disk hash table representation. We walk through every
2992     // selector we've seen and look it up in the method pool.
2993     SelectorOffsets.resize(NextSelectorID - FirstSelectorID);
2994     for (llvm::DenseMap<Selector, SelectorID>::iterator
2995              I = SelectorIDs.begin(), E = SelectorIDs.end();
2996          I != E; ++I) {
2997       Selector S = I->first;
2998       Sema::GlobalMethodPool::iterator F = SemaRef.MethodPool.find(S);
2999       ASTMethodPoolTrait::data_type Data = {
3000         I->second,
3001         ObjCMethodList(),
3002         ObjCMethodList()
3003       };
3004       if (F != SemaRef.MethodPool.end()) {
3005         Data.Instance = F->second.first;
3006         Data.Factory = F->second.second;
3007       }
3008       // Only write this selector if it's not in an existing AST or something
3009       // changed.
3010       if (Chain && I->second < FirstSelectorID) {
3011         // Selector already exists. Did it change?
3012         bool changed = false;
3013         for (ObjCMethodList *M = &Data.Instance;
3014              !changed && M && M->getMethod(); M = M->getNext()) {
3015           if (!M->getMethod()->isFromASTFile())
3016             changed = true;
3017         }
3018         for (ObjCMethodList *M = &Data.Factory; !changed && M && M->getMethod();
3019              M = M->getNext()) {
3020           if (!M->getMethod()->isFromASTFile())
3021             changed = true;
3022         }
3023         if (!changed)
3024           continue;
3025       } else if (Data.Instance.getMethod() || Data.Factory.getMethod()) {
3026         // A new method pool entry.
3027         ++NumTableEntries;
3028       }
3029       Generator.insert(S, Data, Trait);
3030     }
3031 
3032     // Create the on-disk hash table in a buffer.
3033     SmallString<4096> MethodPool;
3034     uint32_t BucketOffset;
3035     {
3036       using namespace llvm::support;
3037       ASTMethodPoolTrait Trait(*this);
3038       llvm::raw_svector_ostream Out(MethodPool);
3039       // Make sure that no bucket is at offset 0
3040       endian::Writer<little>(Out).write<uint32_t>(0);
3041       BucketOffset = Generator.Emit(Out, Trait);
3042     }
3043 
3044     // Create a blob abbreviation
3045     BitCodeAbbrev *Abbrev = new BitCodeAbbrev();
3046     Abbrev->Add(BitCodeAbbrevOp(METHOD_POOL));
3047     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
3048     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
3049     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
3050     unsigned MethodPoolAbbrev = Stream.EmitAbbrev(Abbrev);
3051 
3052     // Write the method pool
3053     RecordData Record;
3054     Record.push_back(METHOD_POOL);
3055     Record.push_back(BucketOffset);
3056     Record.push_back(NumTableEntries);
3057     Stream.EmitRecordWithBlob(MethodPoolAbbrev, Record, MethodPool.str());
3058 
3059     // Create a blob abbreviation for the selector table offsets.
3060     Abbrev = new BitCodeAbbrev();
3061     Abbrev->Add(BitCodeAbbrevOp(SELECTOR_OFFSETS));
3062     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // size
3063     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // first ID
3064     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
3065     unsigned SelectorOffsetAbbrev = Stream.EmitAbbrev(Abbrev);
3066 
3067     // Write the selector offsets table.
3068     Record.clear();
3069     Record.push_back(SELECTOR_OFFSETS);
3070     Record.push_back(SelectorOffsets.size());
3071     Record.push_back(FirstSelectorID - NUM_PREDEF_SELECTOR_IDS);
3072     Stream.EmitRecordWithBlob(SelectorOffsetAbbrev, Record,
3073                               data(SelectorOffsets));
3074   }
3075 }
3076 
3077 /// \brief Write the selectors referenced in @selector expression into AST file.
3078 void ASTWriter::WriteReferencedSelectorsPool(Sema &SemaRef) {
3079   using namespace llvm;
3080   if (SemaRef.ReferencedSelectors.empty())
3081     return;
3082 
3083   RecordData Record;
3084 
3085   // Note: this writes out all references even for a dependent AST. But it is
3086   // very tricky to fix, and given that @selector shouldn't really appear in
3087   // headers, probably not worth it. It's not a correctness issue.
3088   for (DenseMap<Selector, SourceLocation>::iterator S =
3089        SemaRef.ReferencedSelectors.begin(),
3090        E = SemaRef.ReferencedSelectors.end(); S != E; ++S) {
3091     Selector Sel = (*S).first;
3092     SourceLocation Loc = (*S).second;
3093     AddSelectorRef(Sel, Record);
3094     AddSourceLocation(Loc, Record);
3095   }
3096   Stream.EmitRecord(REFERENCED_SELECTOR_POOL, Record);
3097 }
3098 
3099 //===----------------------------------------------------------------------===//
3100 // Identifier Table Serialization
3101 //===----------------------------------------------------------------------===//
3102 
3103 /// Determine the declaration that should be put into the name lookup table to
3104 /// represent the given declaration in this module. This is usually D itself,
3105 /// but if D was imported and merged into a local declaration, we want the most
3106 /// recent local declaration instead. The chosen declaration will be the most
3107 /// recent declaration in any module that imports this one.
3108 static NamedDecl *getDeclForLocalLookup(const LangOptions &LangOpts,
3109                                         NamedDecl *D) {
3110   if (!LangOpts.Modules || !D->isFromASTFile())
3111     return D;
3112 
3113   if (Decl *Redecl = D->getPreviousDecl()) {
3114     // For Redeclarable decls, a prior declaration might be local.
3115     for (; Redecl; Redecl = Redecl->getPreviousDecl()) {
3116       if (!Redecl->isFromASTFile())
3117         return cast<NamedDecl>(Redecl);
3118       // If we come up a decl from a (chained-)PCH stop since we won't find a
3119       // local one.
3120       if (D->getOwningModuleID() == 0)
3121         break;
3122     }
3123   } else if (Decl *First = D->getCanonicalDecl()) {
3124     // For Mergeable decls, the first decl might be local.
3125     if (!First->isFromASTFile())
3126       return cast<NamedDecl>(First);
3127   }
3128 
3129   // All declarations are imported. Our most recent declaration will also be
3130   // the most recent one in anyone who imports us.
3131   return D;
3132 }
3133 
3134 namespace {
3135 class ASTIdentifierTableTrait {
3136   ASTWriter &Writer;
3137   Preprocessor &PP;
3138   IdentifierResolver &IdResolver;
3139   bool IsModule;
3140 
3141   /// \brief Determines whether this is an "interesting" identifier
3142   /// that needs a full IdentifierInfo structure written into the hash
3143   /// table.
3144   bool isInterestingIdentifier(IdentifierInfo *II, MacroDirective *&Macro) {
3145     if (II->isPoisoned() ||
3146         II->isExtensionToken() ||
3147         II->getObjCOrBuiltinID() ||
3148         II->hasRevertedTokenIDToIdentifier() ||
3149         II->getFETokenInfo<void>())
3150       return true;
3151 
3152     return hadMacroDefinition(II, Macro);
3153   }
3154 
3155   bool hadMacroDefinition(IdentifierInfo *II, MacroDirective *&Macro) {
3156     if (!II->hadMacroDefinition())
3157       return false;
3158 
3159     if (Macro || (Macro = PP.getMacroDirectiveHistory(II))) {
3160       if (!IsModule)
3161         return !shouldIgnoreMacro(Macro, IsModule, PP);
3162 
3163       MacroState State;
3164       if (getFirstPublicSubmoduleMacro(Macro, State))
3165         return true;
3166     }
3167 
3168     return false;
3169   }
3170 
3171   enum class SubmoduleMacroState {
3172     /// We've seen nothing about this macro.
3173     None,
3174     /// We've seen a public visibility directive.
3175     Public,
3176     /// We've either exported a macro for this module or found that the
3177     /// module's definition of this macro is private.
3178     Done
3179   };
3180   typedef llvm::DenseMap<SubmoduleID, SubmoduleMacroState> MacroState;
3181 
3182   MacroDirective *
3183   getFirstPublicSubmoduleMacro(MacroDirective *MD, MacroState &State) {
3184     if (MacroDirective *NextMD = getPublicSubmoduleMacro(MD, State))
3185       return NextMD;
3186     return nullptr;
3187   }
3188 
3189   MacroDirective *
3190   getNextPublicSubmoduleMacro(MacroDirective *MD, MacroState &State) {
3191     if (MacroDirective *NextMD =
3192             getPublicSubmoduleMacro(MD->getPrevious(), State))
3193       return NextMD;
3194     return nullptr;
3195   }
3196 
3197   /// \brief Traverses the macro directives history and returns the next
3198   /// public macro definition or undefinition that has not been found so far.
3199   ///
3200   /// A macro that is defined in submodule A and undefined in submodule B
3201   /// will still be considered as defined/exported from submodule A.
3202   MacroDirective *getPublicSubmoduleMacro(MacroDirective *MD,
3203                                           MacroState &State) {
3204     if (!MD)
3205       return nullptr;
3206 
3207     Optional<bool> IsPublic;
3208     for (; MD; MD = MD->getPrevious()) {
3209       // Once we hit an ignored macro, we're done: the rest of the chain
3210       // will all be ignored macros.
3211       if (shouldIgnoreMacro(MD, IsModule, PP))
3212         break;
3213 
3214       // If this macro was imported, re-export it.
3215       if (MD->isImported())
3216         return MD;
3217 
3218       SubmoduleID ModID = getSubmoduleID(MD);
3219       auto &S = State[ModID];
3220       assert(ModID && "found macro in no submodule");
3221 
3222       if (S == SubmoduleMacroState::Done)
3223         continue;
3224 
3225       if (auto *VisMD = dyn_cast<VisibilityMacroDirective>(MD)) {
3226         // The latest visibility directive for a name in a submodule affects all
3227         // the directives that come before it.
3228         if (S == SubmoduleMacroState::None)
3229           S = VisMD->isPublic() ? SubmoduleMacroState::Public
3230                                 : SubmoduleMacroState::Done;
3231       } else {
3232         S = SubmoduleMacroState::Done;
3233         return MD;
3234       }
3235     }
3236 
3237     return nullptr;
3238   }
3239 
3240   ArrayRef<SubmoduleID>
3241   getOverriddenSubmodules(MacroDirective *MD,
3242                           SmallVectorImpl<SubmoduleID> &ScratchSpace) {
3243     assert(!isa<VisibilityMacroDirective>(MD) &&
3244            "only #define and #undef can override");
3245     if (MD->isImported())
3246       return MD->getOverriddenModules();
3247 
3248     ScratchSpace.clear();
3249     SubmoduleID ModID = getSubmoduleID(MD);
3250     for (MD = MD->getPrevious(); MD; MD = MD->getPrevious()) {
3251       if (shouldIgnoreMacro(MD, IsModule, PP))
3252         break;
3253 
3254       // If this is a definition from a submodule import, that submodule's
3255       // definition is overridden by the definition or undefinition that we
3256       // started with.
3257       if (MD->isImported()) {
3258         if (auto *DefMD = dyn_cast<DefMacroDirective>(MD)) {
3259           SubmoduleID DefModuleID = DefMD->getInfo()->getOwningModuleID();
3260           assert(DefModuleID && "imported macro has no owning module");
3261           ScratchSpace.push_back(DefModuleID);
3262         } else if (auto *UndefMD = dyn_cast<UndefMacroDirective>(MD)) {
3263           // If we override a #undef, we override anything that #undef overrides.
3264           // We don't need to override it, since an active #undef doesn't affect
3265           // the meaning of a macro.
3266           auto Overrides = UndefMD->getOverriddenModules();
3267           ScratchSpace.insert(ScratchSpace.end(),
3268                               Overrides.begin(), Overrides.end());
3269         }
3270       }
3271 
3272       // Stop once we leave the original macro's submodule.
3273       //
3274       // Either this submodule #included another submodule of the same
3275       // module or it just happened to be built after the other module.
3276       // In the former case, we override the submodule's macro.
3277       //
3278       // FIXME: In the latter case, we shouldn't do so, but we can't tell
3279       // these cases apart.
3280       //
3281       // FIXME: We can leave this submodule and re-enter it if it #includes a
3282       // header within a different submodule of the same module. In such cases
3283       // the overrides list will be incomplete.
3284       SubmoduleID DirectiveModuleID = getSubmoduleID(MD);
3285       if (DirectiveModuleID != ModID) {
3286         if (DirectiveModuleID && !MD->isImported())
3287           ScratchSpace.push_back(DirectiveModuleID);
3288         break;
3289       }
3290     }
3291 
3292     std::sort(ScratchSpace.begin(), ScratchSpace.end());
3293     ScratchSpace.erase(std::unique(ScratchSpace.begin(), ScratchSpace.end()),
3294                        ScratchSpace.end());
3295     return ScratchSpace;
3296   }
3297 
3298   SubmoduleID getSubmoduleID(MacroDirective *MD) {
3299     return Writer.inferSubmoduleIDFromLocation(MD->getLocation());
3300   }
3301 
3302 public:
3303   typedef IdentifierInfo* key_type;
3304   typedef key_type  key_type_ref;
3305 
3306   typedef IdentID data_type;
3307   typedef data_type data_type_ref;
3308 
3309   typedef unsigned hash_value_type;
3310   typedef unsigned offset_type;
3311 
3312   ASTIdentifierTableTrait(ASTWriter &Writer, Preprocessor &PP,
3313                           IdentifierResolver &IdResolver, bool IsModule)
3314     : Writer(Writer), PP(PP), IdResolver(IdResolver), IsModule(IsModule) { }
3315 
3316   static hash_value_type ComputeHash(const IdentifierInfo* II) {
3317     return llvm::HashString(II->getName());
3318   }
3319 
3320   std::pair<unsigned,unsigned>
3321   EmitKeyDataLength(raw_ostream& Out, IdentifierInfo* II, IdentID ID) {
3322     unsigned KeyLen = II->getLength() + 1;
3323     unsigned DataLen = 4; // 4 bytes for the persistent ID << 1
3324     MacroDirective *Macro = nullptr;
3325     if (isInterestingIdentifier(II, Macro)) {
3326       DataLen += 2; // 2 bytes for builtin ID
3327       DataLen += 2; // 2 bytes for flags
3328       if (hadMacroDefinition(II, Macro)) {
3329         DataLen += 4; // MacroDirectives offset.
3330         if (IsModule) {
3331           MacroState State;
3332           SmallVector<SubmoduleID, 16> Scratch;
3333           for (MacroDirective *MD = getFirstPublicSubmoduleMacro(Macro, State);
3334                MD; MD = getNextPublicSubmoduleMacro(MD, State)) {
3335             DataLen += 4; // MacroInfo ID or ModuleID.
3336             if (unsigned NumOverrides =
3337                     getOverriddenSubmodules(MD, Scratch).size())
3338               DataLen += 4 * (1 + NumOverrides);
3339           }
3340           DataLen += 4; // 0 terminator.
3341         }
3342       }
3343 
3344       for (IdentifierResolver::iterator D = IdResolver.begin(II),
3345                                      DEnd = IdResolver.end();
3346            D != DEnd; ++D)
3347         DataLen += 4;
3348     }
3349     using namespace llvm::support;
3350     endian::Writer<little> LE(Out);
3351 
3352     LE.write<uint16_t>(DataLen);
3353     // We emit the key length after the data length so that every
3354     // string is preceded by a 16-bit length. This matches the PTH
3355     // format for storing identifiers.
3356     LE.write<uint16_t>(KeyLen);
3357     return std::make_pair(KeyLen, DataLen);
3358   }
3359 
3360   void EmitKey(raw_ostream& Out, const IdentifierInfo* II,
3361                unsigned KeyLen) {
3362     // Record the location of the key data.  This is used when generating
3363     // the mapping from persistent IDs to strings.
3364     Writer.SetIdentifierOffset(II, Out.tell());
3365     Out.write(II->getNameStart(), KeyLen);
3366   }
3367 
3368   static void emitMacroOverrides(raw_ostream &Out,
3369                                  ArrayRef<SubmoduleID> Overridden) {
3370     if (!Overridden.empty()) {
3371       using namespace llvm::support;
3372       endian::Writer<little> LE(Out);
3373       LE.write<uint32_t>(Overridden.size() | 0x80000000U);
3374       for (unsigned I = 0, N = Overridden.size(); I != N; ++I) {
3375         assert(Overridden[I] && "zero module ID for override");
3376         LE.write<uint32_t>(Overridden[I]);
3377       }
3378     }
3379   }
3380 
3381   void EmitData(raw_ostream& Out, IdentifierInfo* II,
3382                 IdentID ID, unsigned) {
3383     using namespace llvm::support;
3384     endian::Writer<little> LE(Out);
3385     MacroDirective *Macro = nullptr;
3386     if (!isInterestingIdentifier(II, Macro)) {
3387       LE.write<uint32_t>(ID << 1);
3388       return;
3389     }
3390 
3391     LE.write<uint32_t>((ID << 1) | 0x01);
3392     uint32_t Bits = (uint32_t)II->getObjCOrBuiltinID();
3393     assert((Bits & 0xffff) == Bits && "ObjCOrBuiltinID too big for ASTReader.");
3394     LE.write<uint16_t>(Bits);
3395     Bits = 0;
3396     bool HadMacroDefinition = hadMacroDefinition(II, Macro);
3397     Bits = (Bits << 1) | unsigned(HadMacroDefinition);
3398     Bits = (Bits << 1) | unsigned(IsModule);
3399     Bits = (Bits << 1) | unsigned(II->isExtensionToken());
3400     Bits = (Bits << 1) | unsigned(II->isPoisoned());
3401     Bits = (Bits << 1) | unsigned(II->hasRevertedTokenIDToIdentifier());
3402     Bits = (Bits << 1) | unsigned(II->isCPlusPlusOperatorKeyword());
3403     LE.write<uint16_t>(Bits);
3404 
3405     if (HadMacroDefinition) {
3406       LE.write<uint32_t>(Writer.getMacroDirectivesOffset(II));
3407       if (IsModule) {
3408         // Write the IDs of macros coming from different submodules.
3409         MacroState State;
3410         SmallVector<SubmoduleID, 16> Scratch;
3411         for (MacroDirective *MD = getFirstPublicSubmoduleMacro(Macro, State);
3412              MD; MD = getNextPublicSubmoduleMacro(MD, State)) {
3413           if (DefMacroDirective *DefMD = dyn_cast<DefMacroDirective>(MD)) {
3414             // FIXME: If this macro directive was created by #pragma pop_macros,
3415             // or if it was created implicitly by resolving conflicting macros,
3416             // it may be for a different submodule from the one in the MacroInfo
3417             // object. If so, we should write out its owning ModuleID.
3418             MacroID InfoID = Writer.getMacroID(DefMD->getInfo());
3419             assert(InfoID);
3420             LE.write<uint32_t>(InfoID << 1);
3421           } else {
3422             auto *UndefMD = cast<UndefMacroDirective>(MD);
3423             SubmoduleID Mod = UndefMD->isImported()
3424                                   ? UndefMD->getOwningModuleID()
3425                                   : getSubmoduleID(UndefMD);
3426             LE.write<uint32_t>((Mod << 1) | 1);
3427           }
3428           emitMacroOverrides(Out, getOverriddenSubmodules(MD, Scratch));
3429         }
3430         LE.write<uint32_t>(0xdeadbeef);
3431       }
3432     }
3433 
3434     // Emit the declaration IDs in reverse order, because the
3435     // IdentifierResolver provides the declarations as they would be
3436     // visible (e.g., the function "stat" would come before the struct
3437     // "stat"), but the ASTReader adds declarations to the end of the list
3438     // (so we need to see the struct "stat" before the function "stat").
3439     // Only emit declarations that aren't from a chained PCH, though.
3440     SmallVector<NamedDecl *, 16> Decls(IdResolver.begin(II), IdResolver.end());
3441     for (SmallVectorImpl<NamedDecl *>::reverse_iterator D = Decls.rbegin(),
3442                                                         DEnd = Decls.rend();
3443          D != DEnd; ++D)
3444       LE.write<uint32_t>(
3445           Writer.getDeclID(getDeclForLocalLookup(PP.getLangOpts(), *D)));
3446   }
3447 };
3448 } // end anonymous namespace
3449 
3450 /// \brief Write the identifier table into the AST file.
3451 ///
3452 /// The identifier table consists of a blob containing string data
3453 /// (the actual identifiers themselves) and a separate "offsets" index
3454 /// that maps identifier IDs to locations within the blob.
3455 void ASTWriter::WriteIdentifierTable(Preprocessor &PP,
3456                                      IdentifierResolver &IdResolver,
3457                                      bool IsModule) {
3458   using namespace llvm;
3459 
3460   // Create and write out the blob that contains the identifier
3461   // strings.
3462   {
3463     llvm::OnDiskChainedHashTableGenerator<ASTIdentifierTableTrait> Generator;
3464     ASTIdentifierTableTrait Trait(*this, PP, IdResolver, IsModule);
3465 
3466     // Look for any identifiers that were named while processing the
3467     // headers, but are otherwise not needed. We add these to the hash
3468     // table to enable checking of the predefines buffer in the case
3469     // where the user adds new macro definitions when building the AST
3470     // file.
3471     for (IdentifierTable::iterator ID = PP.getIdentifierTable().begin(),
3472                                 IDEnd = PP.getIdentifierTable().end();
3473          ID != IDEnd; ++ID)
3474       getIdentifierRef(ID->second);
3475 
3476     // Create the on-disk hash table representation. We only store offsets
3477     // for identifiers that appear here for the first time.
3478     IdentifierOffsets.resize(NextIdentID - FirstIdentID);
3479     for (llvm::DenseMap<const IdentifierInfo *, IdentID>::iterator
3480            ID = IdentifierIDs.begin(), IDEnd = IdentifierIDs.end();
3481          ID != IDEnd; ++ID) {
3482       assert(ID->first && "NULL identifier in identifier table");
3483       if (!Chain || !ID->first->isFromAST() ||
3484           ID->first->hasChangedSinceDeserialization())
3485         Generator.insert(const_cast<IdentifierInfo *>(ID->first), ID->second,
3486                          Trait);
3487     }
3488 
3489     // Create the on-disk hash table in a buffer.
3490     SmallString<4096> IdentifierTable;
3491     uint32_t BucketOffset;
3492     {
3493       using namespace llvm::support;
3494       ASTIdentifierTableTrait Trait(*this, PP, IdResolver, IsModule);
3495       llvm::raw_svector_ostream Out(IdentifierTable);
3496       // Make sure that no bucket is at offset 0
3497       endian::Writer<little>(Out).write<uint32_t>(0);
3498       BucketOffset = Generator.Emit(Out, Trait);
3499     }
3500 
3501     // Create a blob abbreviation
3502     BitCodeAbbrev *Abbrev = new BitCodeAbbrev();
3503     Abbrev->Add(BitCodeAbbrevOp(IDENTIFIER_TABLE));
3504     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
3505     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
3506     unsigned IDTableAbbrev = Stream.EmitAbbrev(Abbrev);
3507 
3508     // Write the identifier table
3509     RecordData Record;
3510     Record.push_back(IDENTIFIER_TABLE);
3511     Record.push_back(BucketOffset);
3512     Stream.EmitRecordWithBlob(IDTableAbbrev, Record, IdentifierTable.str());
3513   }
3514 
3515   // Write the offsets table for identifier IDs.
3516   BitCodeAbbrev *Abbrev = new BitCodeAbbrev();
3517   Abbrev->Add(BitCodeAbbrevOp(IDENTIFIER_OFFSET));
3518   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // # of identifiers
3519   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // first ID
3520   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
3521   unsigned IdentifierOffsetAbbrev = Stream.EmitAbbrev(Abbrev);
3522 
3523 #ifndef NDEBUG
3524   for (unsigned I = 0, N = IdentifierOffsets.size(); I != N; ++I)
3525     assert(IdentifierOffsets[I] && "Missing identifier offset?");
3526 #endif
3527 
3528   RecordData Record;
3529   Record.push_back(IDENTIFIER_OFFSET);
3530   Record.push_back(IdentifierOffsets.size());
3531   Record.push_back(FirstIdentID - NUM_PREDEF_IDENT_IDS);
3532   Stream.EmitRecordWithBlob(IdentifierOffsetAbbrev, Record,
3533                             data(IdentifierOffsets));
3534 }
3535 
3536 //===----------------------------------------------------------------------===//
3537 // DeclContext's Name Lookup Table Serialization
3538 //===----------------------------------------------------------------------===//
3539 
3540 namespace {
3541 // Trait used for the on-disk hash table used in the method pool.
3542 class ASTDeclContextNameLookupTrait {
3543   ASTWriter &Writer;
3544 
3545 public:
3546   typedef DeclarationName key_type;
3547   typedef key_type key_type_ref;
3548 
3549   typedef DeclContext::lookup_result data_type;
3550   typedef const data_type& data_type_ref;
3551 
3552   typedef unsigned hash_value_type;
3553   typedef unsigned offset_type;
3554 
3555   explicit ASTDeclContextNameLookupTrait(ASTWriter &Writer) : Writer(Writer) { }
3556 
3557   hash_value_type ComputeHash(DeclarationName Name) {
3558     llvm::FoldingSetNodeID ID;
3559     ID.AddInteger(Name.getNameKind());
3560 
3561     switch (Name.getNameKind()) {
3562     case DeclarationName::Identifier:
3563       ID.AddString(Name.getAsIdentifierInfo()->getName());
3564       break;
3565     case DeclarationName::ObjCZeroArgSelector:
3566     case DeclarationName::ObjCOneArgSelector:
3567     case DeclarationName::ObjCMultiArgSelector:
3568       ID.AddInteger(serialization::ComputeHash(Name.getObjCSelector()));
3569       break;
3570     case DeclarationName::CXXConstructorName:
3571     case DeclarationName::CXXDestructorName:
3572     case DeclarationName::CXXConversionFunctionName:
3573       break;
3574     case DeclarationName::CXXOperatorName:
3575       ID.AddInteger(Name.getCXXOverloadedOperator());
3576       break;
3577     case DeclarationName::CXXLiteralOperatorName:
3578       ID.AddString(Name.getCXXLiteralIdentifier()->getName());
3579     case DeclarationName::CXXUsingDirective:
3580       break;
3581     }
3582 
3583     return ID.ComputeHash();
3584   }
3585 
3586   std::pair<unsigned,unsigned>
3587     EmitKeyDataLength(raw_ostream& Out, DeclarationName Name,
3588                       data_type_ref Lookup) {
3589     using namespace llvm::support;
3590     endian::Writer<little> LE(Out);
3591     unsigned KeyLen = 1;
3592     switch (Name.getNameKind()) {
3593     case DeclarationName::Identifier:
3594     case DeclarationName::ObjCZeroArgSelector:
3595     case DeclarationName::ObjCOneArgSelector:
3596     case DeclarationName::ObjCMultiArgSelector:
3597     case DeclarationName::CXXLiteralOperatorName:
3598       KeyLen += 4;
3599       break;
3600     case DeclarationName::CXXOperatorName:
3601       KeyLen += 1;
3602       break;
3603     case DeclarationName::CXXConstructorName:
3604     case DeclarationName::CXXDestructorName:
3605     case DeclarationName::CXXConversionFunctionName:
3606     case DeclarationName::CXXUsingDirective:
3607       break;
3608     }
3609     LE.write<uint16_t>(KeyLen);
3610 
3611     // 2 bytes for num of decls and 4 for each DeclID.
3612     unsigned DataLen = 2 + 4 * Lookup.size();
3613     LE.write<uint16_t>(DataLen);
3614 
3615     return std::make_pair(KeyLen, DataLen);
3616   }
3617 
3618   void EmitKey(raw_ostream& Out, DeclarationName Name, unsigned) {
3619     using namespace llvm::support;
3620     endian::Writer<little> LE(Out);
3621     LE.write<uint8_t>(Name.getNameKind());
3622     switch (Name.getNameKind()) {
3623     case DeclarationName::Identifier:
3624       LE.write<uint32_t>(Writer.getIdentifierRef(Name.getAsIdentifierInfo()));
3625       return;
3626     case DeclarationName::ObjCZeroArgSelector:
3627     case DeclarationName::ObjCOneArgSelector:
3628     case DeclarationName::ObjCMultiArgSelector:
3629       LE.write<uint32_t>(Writer.getSelectorRef(Name.getObjCSelector()));
3630       return;
3631     case DeclarationName::CXXOperatorName:
3632       assert(Name.getCXXOverloadedOperator() < NUM_OVERLOADED_OPERATORS &&
3633              "Invalid operator?");
3634       LE.write<uint8_t>(Name.getCXXOverloadedOperator());
3635       return;
3636     case DeclarationName::CXXLiteralOperatorName:
3637       LE.write<uint32_t>(Writer.getIdentifierRef(Name.getCXXLiteralIdentifier()));
3638       return;
3639     case DeclarationName::CXXConstructorName:
3640     case DeclarationName::CXXDestructorName:
3641     case DeclarationName::CXXConversionFunctionName:
3642     case DeclarationName::CXXUsingDirective:
3643       return;
3644     }
3645 
3646     llvm_unreachable("Invalid name kind?");
3647   }
3648 
3649   void EmitData(raw_ostream& Out, key_type_ref,
3650                 data_type Lookup, unsigned DataLen) {
3651     using namespace llvm::support;
3652     endian::Writer<little> LE(Out);
3653     uint64_t Start = Out.tell(); (void)Start;
3654     LE.write<uint16_t>(Lookup.size());
3655     for (DeclContext::lookup_iterator I = Lookup.begin(), E = Lookup.end();
3656          I != E; ++I)
3657       LE.write<uint32_t>(
3658           Writer.GetDeclRef(getDeclForLocalLookup(Writer.getLangOpts(), *I)));
3659 
3660     assert(Out.tell() - Start == DataLen && "Data length is wrong");
3661   }
3662 };
3663 } // end anonymous namespace
3664 
3665 template<typename Visitor>
3666 void ASTWriter::visitLocalLookupResults(const DeclContext *ConstDC,
3667                                         Visitor AddLookupResult) {
3668   // FIXME: We need to build the lookups table, which is logically const.
3669   DeclContext *DC = const_cast<DeclContext*>(ConstDC);
3670   assert(DC == DC->getPrimaryContext() && "only primary DC has lookup table");
3671 
3672   SmallVector<DeclarationName, 16> ExternalNames;
3673   for (auto &Lookup : *DC->buildLookup()) {
3674     // If there are no local declarations in our lookup result, we don't
3675     // need to write an entry for the name at all unless we're rewriting
3676     // the decl context.
3677     if (!Lookup.second.hasLocalDecls() && !isRewritten(cast<Decl>(DC)))
3678       continue;
3679 
3680     if (Lookup.second.hasExternalDecls() ||
3681         DC->NeedToReconcileExternalVisibleStorage) {
3682       // We don't know for sure what declarations are found by this name,
3683       // because the external source might have a different set from the set
3684       // that are in the lookup map, and we can't update it now without
3685       // risking invalidating our lookup iterator. So add it to a queue to
3686       // deal with later.
3687       ExternalNames.push_back(Lookup.first);
3688       continue;
3689     }
3690 
3691     AddLookupResult(Lookup.first, Lookup.second.getLookupResult());
3692   }
3693 
3694   // Add the names we needed to defer. Note, this shouldn't add any new decls
3695   // to the list we need to serialize: any new declarations we find here should
3696   // be imported from an external source.
3697   // FIXME: What if the external source isn't an ASTReader?
3698   for (const auto &Name : ExternalNames)
3699     AddLookupResult(Name, DC->lookup(Name));
3700 }
3701 
3702 void ASTWriter::AddUpdatedDeclContext(const DeclContext *DC) {
3703   if (UpdatedDeclContexts.insert(DC).second && WritingAST) {
3704     // Ensure we emit all the visible declarations.
3705     visitLocalLookupResults(DC, [&](DeclarationName Name,
3706                                     DeclContext::lookup_result Result) {
3707       for (auto *Decl : Result)
3708         GetDeclRef(getDeclForLocalLookup(getLangOpts(), Decl));
3709     });
3710   }
3711 }
3712 
3713 uint32_t
3714 ASTWriter::GenerateNameLookupTable(const DeclContext *DC,
3715                                    llvm::SmallVectorImpl<char> &LookupTable) {
3716   assert(!DC->LookupPtr.getInt() && "must call buildLookups first");
3717 
3718   llvm::OnDiskChainedHashTableGenerator<ASTDeclContextNameLookupTrait>
3719       Generator;
3720   ASTDeclContextNameLookupTrait Trait(*this);
3721 
3722   // Create the on-disk hash table representation.
3723   DeclarationName ConstructorName;
3724   DeclarationName ConversionName;
3725   SmallVector<NamedDecl *, 8> ConstructorDecls;
3726   SmallVector<NamedDecl *, 4> ConversionDecls;
3727 
3728   visitLocalLookupResults(DC, [&](DeclarationName Name,
3729                                   DeclContext::lookup_result Result) {
3730     if (Result.empty())
3731       return;
3732 
3733     // Different DeclarationName values of certain kinds are mapped to
3734     // identical serialized keys, because we don't want to use type
3735     // identifiers in the keys (since type ids are local to the module).
3736     switch (Name.getNameKind()) {
3737     case DeclarationName::CXXConstructorName:
3738       // There may be different CXXConstructorName DeclarationName values
3739       // in a DeclContext because a UsingDecl that inherits constructors
3740       // has the DeclarationName of the inherited constructors.
3741       if (!ConstructorName)
3742         ConstructorName = Name;
3743       ConstructorDecls.append(Result.begin(), Result.end());
3744       return;
3745 
3746     case DeclarationName::CXXConversionFunctionName:
3747       if (!ConversionName)
3748         ConversionName = Name;
3749       ConversionDecls.append(Result.begin(), Result.end());
3750       return;
3751 
3752     default:
3753       break;
3754     }
3755 
3756     Generator.insert(Name, Result, Trait);
3757   });
3758 
3759   // Add the constructors.
3760   if (!ConstructorDecls.empty()) {
3761     Generator.insert(ConstructorName,
3762                      DeclContext::lookup_result(ConstructorDecls),
3763                      Trait);
3764   }
3765 
3766   // Add the conversion functions.
3767   if (!ConversionDecls.empty()) {
3768     Generator.insert(ConversionName,
3769                      DeclContext::lookup_result(ConversionDecls),
3770                      Trait);
3771   }
3772 
3773   // Create the on-disk hash table in a buffer.
3774   llvm::raw_svector_ostream Out(LookupTable);
3775   // Make sure that no bucket is at offset 0
3776   using namespace llvm::support;
3777   endian::Writer<little>(Out).write<uint32_t>(0);
3778   return Generator.Emit(Out, Trait);
3779 }
3780 
3781 /// \brief Write the block containing all of the declaration IDs
3782 /// visible from the given DeclContext.
3783 ///
3784 /// \returns the offset of the DECL_CONTEXT_VISIBLE block within the
3785 /// bitstream, or 0 if no block was written.
3786 uint64_t ASTWriter::WriteDeclContextVisibleBlock(ASTContext &Context,
3787                                                  DeclContext *DC) {
3788   if (DC->getPrimaryContext() != DC)
3789     return 0;
3790 
3791   // Since there is no name lookup into functions or methods, don't bother to
3792   // build a visible-declarations table for these entities.
3793   if (DC->isFunctionOrMethod())
3794     return 0;
3795 
3796   // If not in C++, we perform name lookup for the translation unit via the
3797   // IdentifierInfo chains, don't bother to build a visible-declarations table.
3798   if (DC->isTranslationUnit() && !Context.getLangOpts().CPlusPlus)
3799     return 0;
3800 
3801   // Serialize the contents of the mapping used for lookup. Note that,
3802   // although we have two very different code paths, the serialized
3803   // representation is the same for both cases: a declaration name,
3804   // followed by a size, followed by references to the visible
3805   // declarations that have that name.
3806   uint64_t Offset = Stream.GetCurrentBitNo();
3807   StoredDeclsMap *Map = DC->buildLookup();
3808   if (!Map || Map->empty())
3809     return 0;
3810 
3811   // Create the on-disk hash table in a buffer.
3812   SmallString<4096> LookupTable;
3813   uint32_t BucketOffset = GenerateNameLookupTable(DC, LookupTable);
3814 
3815   // Write the lookup table
3816   RecordData Record;
3817   Record.push_back(DECL_CONTEXT_VISIBLE);
3818   Record.push_back(BucketOffset);
3819   Stream.EmitRecordWithBlob(DeclContextVisibleLookupAbbrev, Record,
3820                             LookupTable.str());
3821   ++NumVisibleDeclContexts;
3822   return Offset;
3823 }
3824 
3825 /// \brief Write an UPDATE_VISIBLE block for the given context.
3826 ///
3827 /// UPDATE_VISIBLE blocks contain the declarations that are added to an existing
3828 /// DeclContext in a dependent AST file. As such, they only exist for the TU
3829 /// (in C++), for namespaces, and for classes with forward-declared unscoped
3830 /// enumeration members (in C++11).
3831 void ASTWriter::WriteDeclContextVisibleUpdate(const DeclContext *DC) {
3832   StoredDeclsMap *Map = DC->getLookupPtr();
3833   if (!Map || Map->empty())
3834     return;
3835 
3836   // Create the on-disk hash table in a buffer.
3837   SmallString<4096> LookupTable;
3838   uint32_t BucketOffset = GenerateNameLookupTable(DC, LookupTable);
3839 
3840   // Write the lookup table
3841   RecordData Record;
3842   Record.push_back(UPDATE_VISIBLE);
3843   Record.push_back(getDeclID(cast<Decl>(DC)));
3844   Record.push_back(BucketOffset);
3845   Stream.EmitRecordWithBlob(UpdateVisibleAbbrev, Record, LookupTable.str());
3846 }
3847 
3848 /// \brief Write an FP_PRAGMA_OPTIONS block for the given FPOptions.
3849 void ASTWriter::WriteFPPragmaOptions(const FPOptions &Opts) {
3850   RecordData Record;
3851   Record.push_back(Opts.fp_contract);
3852   Stream.EmitRecord(FP_PRAGMA_OPTIONS, Record);
3853 }
3854 
3855 /// \brief Write an OPENCL_EXTENSIONS block for the given OpenCLOptions.
3856 void ASTWriter::WriteOpenCLExtensions(Sema &SemaRef) {
3857   if (!SemaRef.Context.getLangOpts().OpenCL)
3858     return;
3859 
3860   const OpenCLOptions &Opts = SemaRef.getOpenCLOptions();
3861   RecordData Record;
3862 #define OPENCLEXT(nm)  Record.push_back(Opts.nm);
3863 #include "clang/Basic/OpenCLExtensions.def"
3864   Stream.EmitRecord(OPENCL_EXTENSIONS, Record);
3865 }
3866 
3867 void ASTWriter::WriteRedeclarations() {
3868   RecordData LocalRedeclChains;
3869   SmallVector<serialization::LocalRedeclarationsInfo, 2> LocalRedeclsMap;
3870 
3871   for (unsigned I = 0, N = Redeclarations.size(); I != N; ++I) {
3872     Decl *First = Redeclarations[I];
3873     assert(First->isFirstDecl() && "Not the first declaration?");
3874 
3875     Decl *MostRecent = First->getMostRecentDecl();
3876 
3877     // If we only have a single declaration, there is no point in storing
3878     // a redeclaration chain.
3879     if (First == MostRecent)
3880       continue;
3881 
3882     unsigned Offset = LocalRedeclChains.size();
3883     unsigned Size = 0;
3884     LocalRedeclChains.push_back(0); // Placeholder for the size.
3885 
3886     // Collect the set of local redeclarations of this declaration.
3887     for (Decl *Prev = MostRecent; Prev != First;
3888          Prev = Prev->getPreviousDecl()) {
3889       if (!Prev->isFromASTFile()) {
3890         AddDeclRef(Prev, LocalRedeclChains);
3891         ++Size;
3892       }
3893     }
3894 
3895     if (!First->isFromASTFile() && Chain) {
3896       Decl *FirstFromAST = MostRecent;
3897       for (Decl *Prev = MostRecent; Prev; Prev = Prev->getPreviousDecl()) {
3898         if (Prev->isFromASTFile())
3899           FirstFromAST = Prev;
3900       }
3901 
3902       // FIXME: Do we need to do this for the first declaration from each
3903       // redeclaration chain that was merged into this one?
3904       Chain->MergedDecls[FirstFromAST].push_back(getDeclID(First));
3905     }
3906 
3907     LocalRedeclChains[Offset] = Size;
3908 
3909     // Reverse the set of local redeclarations, so that we store them in
3910     // order (since we found them in reverse order).
3911     std::reverse(LocalRedeclChains.end() - Size, LocalRedeclChains.end());
3912 
3913     // Add the mapping from the first ID from the AST to the set of local
3914     // declarations.
3915     LocalRedeclarationsInfo Info = { getDeclID(First), Offset };
3916     LocalRedeclsMap.push_back(Info);
3917 
3918     assert(N == Redeclarations.size() &&
3919            "Deserialized a declaration we shouldn't have");
3920   }
3921 
3922   if (LocalRedeclChains.empty())
3923     return;
3924 
3925   // Sort the local redeclarations map by the first declaration ID,
3926   // since the reader will be performing binary searches on this information.
3927   llvm::array_pod_sort(LocalRedeclsMap.begin(), LocalRedeclsMap.end());
3928 
3929   // Emit the local redeclarations map.
3930   using namespace llvm;
3931   llvm::BitCodeAbbrev *Abbrev = new BitCodeAbbrev();
3932   Abbrev->Add(BitCodeAbbrevOp(LOCAL_REDECLARATIONS_MAP));
3933   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // # of entries
3934   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
3935   unsigned AbbrevID = Stream.EmitAbbrev(Abbrev);
3936 
3937   RecordData Record;
3938   Record.push_back(LOCAL_REDECLARATIONS_MAP);
3939   Record.push_back(LocalRedeclsMap.size());
3940   Stream.EmitRecordWithBlob(AbbrevID, Record,
3941     reinterpret_cast<char*>(LocalRedeclsMap.data()),
3942     LocalRedeclsMap.size() * sizeof(LocalRedeclarationsInfo));
3943 
3944   // Emit the redeclaration chains.
3945   Stream.EmitRecord(LOCAL_REDECLARATIONS, LocalRedeclChains);
3946 }
3947 
3948 void ASTWriter::WriteObjCCategories() {
3949   SmallVector<ObjCCategoriesInfo, 2> CategoriesMap;
3950   RecordData Categories;
3951 
3952   for (unsigned I = 0, N = ObjCClassesWithCategories.size(); I != N; ++I) {
3953     unsigned Size = 0;
3954     unsigned StartIndex = Categories.size();
3955 
3956     ObjCInterfaceDecl *Class = ObjCClassesWithCategories[I];
3957 
3958     // Allocate space for the size.
3959     Categories.push_back(0);
3960 
3961     // Add the categories.
3962     for (ObjCInterfaceDecl::known_categories_iterator
3963            Cat = Class->known_categories_begin(),
3964            CatEnd = Class->known_categories_end();
3965          Cat != CatEnd; ++Cat, ++Size) {
3966       assert(getDeclID(*Cat) != 0 && "Bogus category");
3967       AddDeclRef(*Cat, Categories);
3968     }
3969 
3970     // Update the size.
3971     Categories[StartIndex] = Size;
3972 
3973     // Record this interface -> category map.
3974     ObjCCategoriesInfo CatInfo = { getDeclID(Class), StartIndex };
3975     CategoriesMap.push_back(CatInfo);
3976   }
3977 
3978   // Sort the categories map by the definition ID, since the reader will be
3979   // performing binary searches on this information.
3980   llvm::array_pod_sort(CategoriesMap.begin(), CategoriesMap.end());
3981 
3982   // Emit the categories map.
3983   using namespace llvm;
3984   llvm::BitCodeAbbrev *Abbrev = new BitCodeAbbrev();
3985   Abbrev->Add(BitCodeAbbrevOp(OBJC_CATEGORIES_MAP));
3986   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // # of entries
3987   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
3988   unsigned AbbrevID = Stream.EmitAbbrev(Abbrev);
3989 
3990   RecordData Record;
3991   Record.push_back(OBJC_CATEGORIES_MAP);
3992   Record.push_back(CategoriesMap.size());
3993   Stream.EmitRecordWithBlob(AbbrevID, Record,
3994                             reinterpret_cast<char*>(CategoriesMap.data()),
3995                             CategoriesMap.size() * sizeof(ObjCCategoriesInfo));
3996 
3997   // Emit the category lists.
3998   Stream.EmitRecord(OBJC_CATEGORIES, Categories);
3999 }
4000 
4001 void ASTWriter::WriteMergedDecls() {
4002   if (!Chain || Chain->MergedDecls.empty())
4003     return;
4004 
4005   RecordData Record;
4006   for (ASTReader::MergedDeclsMap::iterator I = Chain->MergedDecls.begin(),
4007                                         IEnd = Chain->MergedDecls.end();
4008        I != IEnd; ++I) {
4009     DeclID CanonID = I->first->isFromASTFile()? I->first->getGlobalID()
4010                                               : GetDeclRef(I->first);
4011     assert(CanonID && "Merged declaration not known?");
4012 
4013     Record.push_back(CanonID);
4014     Record.push_back(I->second.size());
4015     Record.append(I->second.begin(), I->second.end());
4016   }
4017   Stream.EmitRecord(MERGED_DECLARATIONS, Record);
4018 }
4019 
4020 void ASTWriter::WriteLateParsedTemplates(Sema &SemaRef) {
4021   Sema::LateParsedTemplateMapT &LPTMap = SemaRef.LateParsedTemplateMap;
4022 
4023   if (LPTMap.empty())
4024     return;
4025 
4026   RecordData Record;
4027   for (Sema::LateParsedTemplateMapT::iterator It = LPTMap.begin(),
4028                                               ItEnd = LPTMap.end();
4029        It != ItEnd; ++It) {
4030     LateParsedTemplate *LPT = It->second;
4031     AddDeclRef(It->first, Record);
4032     AddDeclRef(LPT->D, Record);
4033     Record.push_back(LPT->Toks.size());
4034 
4035     for (CachedTokens::iterator TokIt = LPT->Toks.begin(),
4036                                 TokEnd = LPT->Toks.end();
4037          TokIt != TokEnd; ++TokIt) {
4038       AddToken(*TokIt, Record);
4039     }
4040   }
4041   Stream.EmitRecord(LATE_PARSED_TEMPLATE, Record);
4042 }
4043 
4044 /// \brief Write the state of 'pragma clang optimize' at the end of the module.
4045 void ASTWriter::WriteOptimizePragmaOptions(Sema &SemaRef) {
4046   RecordData Record;
4047   SourceLocation PragmaLoc = SemaRef.getOptimizeOffPragmaLocation();
4048   AddSourceLocation(PragmaLoc, Record);
4049   Stream.EmitRecord(OPTIMIZE_PRAGMA_OPTIONS, Record);
4050 }
4051 
4052 //===----------------------------------------------------------------------===//
4053 // General Serialization Routines
4054 //===----------------------------------------------------------------------===//
4055 
4056 /// \brief Write a record containing the given attributes.
4057 void ASTWriter::WriteAttributes(ArrayRef<const Attr*> Attrs,
4058                                 RecordDataImpl &Record) {
4059   Record.push_back(Attrs.size());
4060   for (ArrayRef<const Attr *>::iterator i = Attrs.begin(),
4061                                         e = Attrs.end(); i != e; ++i){
4062     const Attr *A = *i;
4063     Record.push_back(A->getKind()); // FIXME: stable encoding, target attrs
4064     AddSourceRange(A->getRange(), Record);
4065 
4066 #include "clang/Serialization/AttrPCHWrite.inc"
4067 
4068   }
4069 }
4070 
4071 void ASTWriter::AddToken(const Token &Tok, RecordDataImpl &Record) {
4072   AddSourceLocation(Tok.getLocation(), Record);
4073   Record.push_back(Tok.getLength());
4074 
4075   // FIXME: When reading literal tokens, reconstruct the literal pointer
4076   // if it is needed.
4077   AddIdentifierRef(Tok.getIdentifierInfo(), Record);
4078   // FIXME: Should translate token kind to a stable encoding.
4079   Record.push_back(Tok.getKind());
4080   // FIXME: Should translate token flags to a stable encoding.
4081   Record.push_back(Tok.getFlags());
4082 }
4083 
4084 void ASTWriter::AddString(StringRef Str, RecordDataImpl &Record) {
4085   Record.push_back(Str.size());
4086   Record.insert(Record.end(), Str.begin(), Str.end());
4087 }
4088 
4089 bool ASTWriter::PreparePathForOutput(SmallVectorImpl<char> &Path) {
4090   assert(Context && "should have context when outputting path");
4091 
4092   bool Changed =
4093       cleanPathForOutput(Context->getSourceManager().getFileManager(), Path);
4094 
4095   // Remove a prefix to make the path relative, if relevant.
4096   const char *PathBegin = Path.data();
4097   const char *PathPtr =
4098       adjustFilenameForRelocatableAST(PathBegin, BaseDirectory);
4099   if (PathPtr != PathBegin) {
4100     Path.erase(Path.begin(), Path.begin() + (PathPtr - PathBegin));
4101     Changed = true;
4102   }
4103 
4104   return Changed;
4105 }
4106 
4107 void ASTWriter::AddPath(StringRef Path, RecordDataImpl &Record) {
4108   SmallString<128> FilePath(Path);
4109   PreparePathForOutput(FilePath);
4110   AddString(FilePath, Record);
4111 }
4112 
4113 void ASTWriter::EmitRecordWithPath(unsigned Abbrev, RecordDataImpl &Record,
4114                                    StringRef Path) {
4115   SmallString<128> FilePath(Path);
4116   PreparePathForOutput(FilePath);
4117   Stream.EmitRecordWithBlob(Abbrev, Record, FilePath);
4118 }
4119 
4120 void ASTWriter::AddVersionTuple(const VersionTuple &Version,
4121                                 RecordDataImpl &Record) {
4122   Record.push_back(Version.getMajor());
4123   if (Optional<unsigned> Minor = Version.getMinor())
4124     Record.push_back(*Minor + 1);
4125   else
4126     Record.push_back(0);
4127   if (Optional<unsigned> Subminor = Version.getSubminor())
4128     Record.push_back(*Subminor + 1);
4129   else
4130     Record.push_back(0);
4131 }
4132 
4133 /// \brief Note that the identifier II occurs at the given offset
4134 /// within the identifier table.
4135 void ASTWriter::SetIdentifierOffset(const IdentifierInfo *II, uint32_t Offset) {
4136   IdentID ID = IdentifierIDs[II];
4137   // Only store offsets new to this AST file. Other identifier names are looked
4138   // up earlier in the chain and thus don't need an offset.
4139   if (ID >= FirstIdentID)
4140     IdentifierOffsets[ID - FirstIdentID] = Offset;
4141 }
4142 
4143 /// \brief Note that the selector Sel occurs at the given offset
4144 /// within the method pool/selector table.
4145 void ASTWriter::SetSelectorOffset(Selector Sel, uint32_t Offset) {
4146   unsigned ID = SelectorIDs[Sel];
4147   assert(ID && "Unknown selector");
4148   // Don't record offsets for selectors that are also available in a different
4149   // file.
4150   if (ID < FirstSelectorID)
4151     return;
4152   SelectorOffsets[ID - FirstSelectorID] = Offset;
4153 }
4154 
4155 ASTWriter::ASTWriter(llvm::BitstreamWriter &Stream)
4156     : Stream(Stream), Context(nullptr), PP(nullptr), Chain(nullptr),
4157       WritingModule(nullptr), WritingAST(false),
4158       DoneWritingDeclsAndTypes(false), ASTHasCompilerErrors(false),
4159       FirstDeclID(NUM_PREDEF_DECL_IDS), NextDeclID(FirstDeclID),
4160       FirstTypeID(NUM_PREDEF_TYPE_IDS), NextTypeID(FirstTypeID),
4161       FirstIdentID(NUM_PREDEF_IDENT_IDS), NextIdentID(FirstIdentID),
4162       FirstMacroID(NUM_PREDEF_MACRO_IDS), NextMacroID(FirstMacroID),
4163       FirstSubmoduleID(NUM_PREDEF_SUBMODULE_IDS),
4164       NextSubmoduleID(FirstSubmoduleID),
4165       FirstSelectorID(NUM_PREDEF_SELECTOR_IDS), NextSelectorID(FirstSelectorID),
4166       CollectedStmts(&StmtsToEmit), NumStatements(0), NumMacros(0),
4167       NumLexicalDeclContexts(0), NumVisibleDeclContexts(0),
4168       NextCXXBaseSpecifiersID(1), TypeExtQualAbbrev(0),
4169       TypeFunctionProtoAbbrev(0), DeclParmVarAbbrev(0),
4170       DeclContextLexicalAbbrev(0), DeclContextVisibleLookupAbbrev(0),
4171       UpdateVisibleAbbrev(0), DeclRecordAbbrev(0), DeclTypedefAbbrev(0),
4172       DeclVarAbbrev(0), DeclFieldAbbrev(0), DeclEnumAbbrev(0),
4173       DeclObjCIvarAbbrev(0), DeclCXXMethodAbbrev(0), DeclRefExprAbbrev(0),
4174       CharacterLiteralAbbrev(0), IntegerLiteralAbbrev(0),
4175       ExprImplicitCastAbbrev(0) {}
4176 
4177 ASTWriter::~ASTWriter() {
4178   llvm::DeleteContainerSeconds(FileDeclIDs);
4179 }
4180 
4181 const LangOptions &ASTWriter::getLangOpts() const {
4182   assert(WritingAST && "can't determine lang opts when not writing AST");
4183   return Context->getLangOpts();
4184 }
4185 
4186 void ASTWriter::WriteAST(Sema &SemaRef,
4187                          const std::string &OutputFile,
4188                          Module *WritingModule, StringRef isysroot,
4189                          bool hasErrors) {
4190   WritingAST = true;
4191 
4192   ASTHasCompilerErrors = hasErrors;
4193 
4194   // Emit the file header.
4195   Stream.Emit((unsigned)'C', 8);
4196   Stream.Emit((unsigned)'P', 8);
4197   Stream.Emit((unsigned)'C', 8);
4198   Stream.Emit((unsigned)'H', 8);
4199 
4200   WriteBlockInfoBlock();
4201 
4202   Context = &SemaRef.Context;
4203   PP = &SemaRef.PP;
4204   this->WritingModule = WritingModule;
4205   WriteASTCore(SemaRef, isysroot, OutputFile, WritingModule);
4206   Context = nullptr;
4207   PP = nullptr;
4208   this->WritingModule = nullptr;
4209   this->BaseDirectory.clear();
4210 
4211   WritingAST = false;
4212 }
4213 
4214 template<typename Vector>
4215 static void AddLazyVectorDecls(ASTWriter &Writer, Vector &Vec,
4216                                ASTWriter::RecordData &Record) {
4217   for (typename Vector::iterator I = Vec.begin(nullptr, true), E = Vec.end();
4218        I != E; ++I) {
4219     Writer.AddDeclRef(*I, Record);
4220   }
4221 }
4222 
4223 void ASTWriter::WriteASTCore(Sema &SemaRef,
4224                              StringRef isysroot,
4225                              const std::string &OutputFile,
4226                              Module *WritingModule) {
4227   using namespace llvm;
4228 
4229   bool isModule = WritingModule != nullptr;
4230 
4231   // Make sure that the AST reader knows to finalize itself.
4232   if (Chain)
4233     Chain->finalizeForWriting();
4234 
4235   ASTContext &Context = SemaRef.Context;
4236   Preprocessor &PP = SemaRef.PP;
4237 
4238   // Set up predefined declaration IDs.
4239   DeclIDs[Context.getTranslationUnitDecl()] = PREDEF_DECL_TRANSLATION_UNIT_ID;
4240   if (Context.ObjCIdDecl)
4241     DeclIDs[Context.ObjCIdDecl] = PREDEF_DECL_OBJC_ID_ID;
4242   if (Context.ObjCSelDecl)
4243     DeclIDs[Context.ObjCSelDecl] = PREDEF_DECL_OBJC_SEL_ID;
4244   if (Context.ObjCClassDecl)
4245     DeclIDs[Context.ObjCClassDecl] = PREDEF_DECL_OBJC_CLASS_ID;
4246   if (Context.ObjCProtocolClassDecl)
4247     DeclIDs[Context.ObjCProtocolClassDecl] = PREDEF_DECL_OBJC_PROTOCOL_ID;
4248   if (Context.Int128Decl)
4249     DeclIDs[Context.Int128Decl] = PREDEF_DECL_INT_128_ID;
4250   if (Context.UInt128Decl)
4251     DeclIDs[Context.UInt128Decl] = PREDEF_DECL_UNSIGNED_INT_128_ID;
4252   if (Context.ObjCInstanceTypeDecl)
4253     DeclIDs[Context.ObjCInstanceTypeDecl] = PREDEF_DECL_OBJC_INSTANCETYPE_ID;
4254   if (Context.BuiltinVaListDecl)
4255     DeclIDs[Context.getBuiltinVaListDecl()] = PREDEF_DECL_BUILTIN_VA_LIST_ID;
4256 
4257   if (!Chain) {
4258     // Make sure that we emit IdentifierInfos (and any attached
4259     // declarations) for builtins. We don't need to do this when we're
4260     // emitting chained PCH files, because all of the builtins will be
4261     // in the original PCH file.
4262     // FIXME: Modules won't like this at all.
4263     IdentifierTable &Table = PP.getIdentifierTable();
4264     SmallVector<const char *, 32> BuiltinNames;
4265     if (!Context.getLangOpts().NoBuiltin) {
4266       Context.BuiltinInfo.GetBuiltinNames(BuiltinNames);
4267     }
4268     for (unsigned I = 0, N = BuiltinNames.size(); I != N; ++I)
4269       getIdentifierRef(&Table.get(BuiltinNames[I]));
4270   }
4271 
4272   // If we saw any DeclContext updates before we started writing the AST file,
4273   // make sure all visible decls in those DeclContexts are written out.
4274   if (!UpdatedDeclContexts.empty()) {
4275     auto OldUpdatedDeclContexts = std::move(UpdatedDeclContexts);
4276     UpdatedDeclContexts.clear();
4277     for (auto *DC : OldUpdatedDeclContexts)
4278       AddUpdatedDeclContext(DC);
4279   }
4280 
4281   // Build a record containing all of the tentative definitions in this file, in
4282   // TentativeDefinitions order.  Generally, this record will be empty for
4283   // headers.
4284   RecordData TentativeDefinitions;
4285   AddLazyVectorDecls(*this, SemaRef.TentativeDefinitions, TentativeDefinitions);
4286 
4287   // Build a record containing all of the file scoped decls in this file.
4288   RecordData UnusedFileScopedDecls;
4289   if (!isModule)
4290     AddLazyVectorDecls(*this, SemaRef.UnusedFileScopedDecls,
4291                        UnusedFileScopedDecls);
4292 
4293   // Build a record containing all of the delegating constructors we still need
4294   // to resolve.
4295   RecordData DelegatingCtorDecls;
4296   if (!isModule)
4297     AddLazyVectorDecls(*this, SemaRef.DelegatingCtorDecls, DelegatingCtorDecls);
4298 
4299   // Write the set of weak, undeclared identifiers. We always write the
4300   // entire table, since later PCH files in a PCH chain are only interested in
4301   // the results at the end of the chain.
4302   RecordData WeakUndeclaredIdentifiers;
4303   if (!SemaRef.WeakUndeclaredIdentifiers.empty()) {
4304     for (llvm::DenseMap<IdentifierInfo*,WeakInfo>::iterator
4305          I = SemaRef.WeakUndeclaredIdentifiers.begin(),
4306          E = SemaRef.WeakUndeclaredIdentifiers.end(); I != E; ++I) {
4307       AddIdentifierRef(I->first, WeakUndeclaredIdentifiers);
4308       AddIdentifierRef(I->second.getAlias(), WeakUndeclaredIdentifiers);
4309       AddSourceLocation(I->second.getLocation(), WeakUndeclaredIdentifiers);
4310       WeakUndeclaredIdentifiers.push_back(I->second.getUsed());
4311     }
4312   }
4313 
4314   // Build a record containing all of the locally-scoped extern "C"
4315   // declarations in this header file. Generally, this record will be
4316   // empty.
4317   RecordData LocallyScopedExternCDecls;
4318   // FIXME: This is filling in the AST file in densemap order which is
4319   // nondeterminstic!
4320   for (llvm::DenseMap<DeclarationName, NamedDecl *>::iterator
4321          TD = SemaRef.LocallyScopedExternCDecls.begin(),
4322          TDEnd = SemaRef.LocallyScopedExternCDecls.end();
4323        TD != TDEnd; ++TD) {
4324     if (!TD->second->isFromASTFile())
4325       AddDeclRef(TD->second, LocallyScopedExternCDecls);
4326   }
4327 
4328   // Build a record containing all of the ext_vector declarations.
4329   RecordData ExtVectorDecls;
4330   AddLazyVectorDecls(*this, SemaRef.ExtVectorDecls, ExtVectorDecls);
4331 
4332   // Build a record containing all of the VTable uses information.
4333   RecordData VTableUses;
4334   if (!SemaRef.VTableUses.empty()) {
4335     for (unsigned I = 0, N = SemaRef.VTableUses.size(); I != N; ++I) {
4336       AddDeclRef(SemaRef.VTableUses[I].first, VTableUses);
4337       AddSourceLocation(SemaRef.VTableUses[I].second, VTableUses);
4338       VTableUses.push_back(SemaRef.VTablesUsed[SemaRef.VTableUses[I].first]);
4339     }
4340   }
4341 
4342   // Build a record containing all of the UnusedLocalTypedefNameCandidates.
4343   RecordData UnusedLocalTypedefNameCandidates;
4344   for (const TypedefNameDecl *TD : SemaRef.UnusedLocalTypedefNameCandidates)
4345     AddDeclRef(TD, UnusedLocalTypedefNameCandidates);
4346 
4347   // Build a record containing all of pending implicit instantiations.
4348   RecordData PendingInstantiations;
4349   for (std::deque<Sema::PendingImplicitInstantiation>::iterator
4350          I = SemaRef.PendingInstantiations.begin(),
4351          N = SemaRef.PendingInstantiations.end(); I != N; ++I) {
4352     AddDeclRef(I->first, PendingInstantiations);
4353     AddSourceLocation(I->second, PendingInstantiations);
4354   }
4355   assert(SemaRef.PendingLocalImplicitInstantiations.empty() &&
4356          "There are local ones at end of translation unit!");
4357 
4358   // Build a record containing some declaration references.
4359   RecordData SemaDeclRefs;
4360   if (SemaRef.StdNamespace || SemaRef.StdBadAlloc) {
4361     AddDeclRef(SemaRef.getStdNamespace(), SemaDeclRefs);
4362     AddDeclRef(SemaRef.getStdBadAlloc(), SemaDeclRefs);
4363   }
4364 
4365   RecordData CUDASpecialDeclRefs;
4366   if (Context.getcudaConfigureCallDecl()) {
4367     AddDeclRef(Context.getcudaConfigureCallDecl(), CUDASpecialDeclRefs);
4368   }
4369 
4370   // Build a record containing all of the known namespaces.
4371   RecordData KnownNamespaces;
4372   for (llvm::MapVector<NamespaceDecl*, bool>::iterator
4373             I = SemaRef.KnownNamespaces.begin(),
4374          IEnd = SemaRef.KnownNamespaces.end();
4375        I != IEnd; ++I) {
4376     if (!I->second)
4377       AddDeclRef(I->first, KnownNamespaces);
4378   }
4379 
4380   // Build a record of all used, undefined objects that require definitions.
4381   RecordData UndefinedButUsed;
4382 
4383   SmallVector<std::pair<NamedDecl *, SourceLocation>, 16> Undefined;
4384   SemaRef.getUndefinedButUsed(Undefined);
4385   for (SmallVectorImpl<std::pair<NamedDecl *, SourceLocation> >::iterator
4386          I = Undefined.begin(), E = Undefined.end(); I != E; ++I) {
4387     AddDeclRef(I->first, UndefinedButUsed);
4388     AddSourceLocation(I->second, UndefinedButUsed);
4389   }
4390 
4391   // Write the control block
4392   WriteControlBlock(PP, Context, isysroot, OutputFile);
4393 
4394   // Write the remaining AST contents.
4395   RecordData Record;
4396   Stream.EnterSubblock(AST_BLOCK_ID, 5);
4397 
4398   // This is so that older clang versions, before the introduction
4399   // of the control block, can read and reject the newer PCH format.
4400   Record.clear();
4401   Record.push_back(VERSION_MAJOR);
4402   Stream.EmitRecord(METADATA_OLD_FORMAT, Record);
4403 
4404   // Create a lexical update block containing all of the declarations in the
4405   // translation unit that do not come from other AST files.
4406   const TranslationUnitDecl *TU = Context.getTranslationUnitDecl();
4407   SmallVector<KindDeclIDPair, 64> NewGlobalDecls;
4408   for (const auto *I : TU->noload_decls()) {
4409     if (!I->isFromASTFile())
4410       NewGlobalDecls.push_back(std::make_pair(I->getKind(), GetDeclRef(I)));
4411   }
4412 
4413   llvm::BitCodeAbbrev *Abv = new llvm::BitCodeAbbrev();
4414   Abv->Add(llvm::BitCodeAbbrevOp(TU_UPDATE_LEXICAL));
4415   Abv->Add(llvm::BitCodeAbbrevOp(llvm::BitCodeAbbrevOp::Blob));
4416   unsigned TuUpdateLexicalAbbrev = Stream.EmitAbbrev(Abv);
4417   Record.clear();
4418   Record.push_back(TU_UPDATE_LEXICAL);
4419   Stream.EmitRecordWithBlob(TuUpdateLexicalAbbrev, Record,
4420                             data(NewGlobalDecls));
4421 
4422   // And a visible updates block for the translation unit.
4423   Abv = new llvm::BitCodeAbbrev();
4424   Abv->Add(llvm::BitCodeAbbrevOp(UPDATE_VISIBLE));
4425   Abv->Add(llvm::BitCodeAbbrevOp(llvm::BitCodeAbbrevOp::VBR, 6));
4426   Abv->Add(llvm::BitCodeAbbrevOp(llvm::BitCodeAbbrevOp::Fixed, 32));
4427   Abv->Add(llvm::BitCodeAbbrevOp(llvm::BitCodeAbbrevOp::Blob));
4428   UpdateVisibleAbbrev = Stream.EmitAbbrev(Abv);
4429   WriteDeclContextVisibleUpdate(TU);
4430 
4431   // If the translation unit has an anonymous namespace, and we don't already
4432   // have an update block for it, write it as an update block.
4433   // FIXME: Why do we not do this if there's already an update block?
4434   if (NamespaceDecl *NS = TU->getAnonymousNamespace()) {
4435     ASTWriter::UpdateRecord &Record = DeclUpdates[TU];
4436     if (Record.empty())
4437       Record.push_back(DeclUpdate(UPD_CXX_ADDED_ANONYMOUS_NAMESPACE, NS));
4438   }
4439 
4440   // Add update records for all mangling numbers and static local numbers.
4441   // These aren't really update records, but this is a convenient way of
4442   // tagging this rare extra data onto the declarations.
4443   for (const auto &Number : Context.MangleNumbers)
4444     if (!Number.first->isFromASTFile())
4445       DeclUpdates[Number.first].push_back(DeclUpdate(UPD_MANGLING_NUMBER,
4446                                                      Number.second));
4447   for (const auto &Number : Context.StaticLocalNumbers)
4448     if (!Number.first->isFromASTFile())
4449       DeclUpdates[Number.first].push_back(DeclUpdate(UPD_STATIC_LOCAL_NUMBER,
4450                                                      Number.second));
4451 
4452   // Make sure visible decls, added to DeclContexts previously loaded from
4453   // an AST file, are registered for serialization.
4454   for (SmallVectorImpl<const Decl *>::iterator
4455          I = UpdatingVisibleDecls.begin(),
4456          E = UpdatingVisibleDecls.end(); I != E; ++I) {
4457     GetDeclRef(*I);
4458   }
4459 
4460   // Make sure all decls associated with an identifier are registered for
4461   // serialization.
4462   for (IdentifierTable::iterator ID = PP.getIdentifierTable().begin(),
4463                               IDEnd = PP.getIdentifierTable().end();
4464        ID != IDEnd; ++ID) {
4465     const IdentifierInfo *II = ID->second;
4466     if (!Chain || !II->isFromAST() || II->hasChangedSinceDeserialization()) {
4467       for (IdentifierResolver::iterator D = SemaRef.IdResolver.begin(II),
4468                                      DEnd = SemaRef.IdResolver.end();
4469            D != DEnd; ++D) {
4470         GetDeclRef(*D);
4471       }
4472     }
4473   }
4474 
4475   // Form the record of special types.
4476   RecordData SpecialTypes;
4477   AddTypeRef(Context.getRawCFConstantStringType(), SpecialTypes);
4478   AddTypeRef(Context.getFILEType(), SpecialTypes);
4479   AddTypeRef(Context.getjmp_bufType(), SpecialTypes);
4480   AddTypeRef(Context.getsigjmp_bufType(), SpecialTypes);
4481   AddTypeRef(Context.ObjCIdRedefinitionType, SpecialTypes);
4482   AddTypeRef(Context.ObjCClassRedefinitionType, SpecialTypes);
4483   AddTypeRef(Context.ObjCSelRedefinitionType, SpecialTypes);
4484   AddTypeRef(Context.getucontext_tType(), SpecialTypes);
4485 
4486   if (Chain) {
4487     // Write the mapping information describing our module dependencies and how
4488     // each of those modules were mapped into our own offset/ID space, so that
4489     // the reader can build the appropriate mapping to its own offset/ID space.
4490     // The map consists solely of a blob with the following format:
4491     // *(module-name-len:i16 module-name:len*i8
4492     //   source-location-offset:i32
4493     //   identifier-id:i32
4494     //   preprocessed-entity-id:i32
4495     //   macro-definition-id:i32
4496     //   submodule-id:i32
4497     //   selector-id:i32
4498     //   declaration-id:i32
4499     //   c++-base-specifiers-id:i32
4500     //   type-id:i32)
4501     //
4502     llvm::BitCodeAbbrev *Abbrev = new BitCodeAbbrev();
4503     Abbrev->Add(BitCodeAbbrevOp(MODULE_OFFSET_MAP));
4504     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
4505     unsigned ModuleOffsetMapAbbrev = Stream.EmitAbbrev(Abbrev);
4506     SmallString<2048> Buffer;
4507     {
4508       llvm::raw_svector_ostream Out(Buffer);
4509       for (ModuleFile *M : Chain->ModuleMgr) {
4510         using namespace llvm::support;
4511         endian::Writer<little> LE(Out);
4512         StringRef FileName = M->FileName;
4513         LE.write<uint16_t>(FileName.size());
4514         Out.write(FileName.data(), FileName.size());
4515 
4516         // Note: if a base ID was uint max, it would not be possible to load
4517         // another module after it or have more than one entity inside it.
4518         uint32_t None = std::numeric_limits<uint32_t>::max();
4519 
4520         auto writeBaseIDOrNone = [&](uint32_t BaseID, bool ShouldWrite) {
4521           assert(BaseID < std::numeric_limits<uint32_t>::max() && "base id too high");
4522           if (ShouldWrite)
4523             LE.write<uint32_t>(BaseID);
4524           else
4525             LE.write<uint32_t>(None);
4526         };
4527 
4528         // These values should be unique within a chain, since they will be read
4529         // as keys into ContinuousRangeMaps.
4530         writeBaseIDOrNone(M->SLocEntryBaseOffset, M->LocalNumSLocEntries);
4531         writeBaseIDOrNone(M->BaseIdentifierID, M->LocalNumIdentifiers);
4532         writeBaseIDOrNone(M->BaseMacroID, M->LocalNumMacros);
4533         writeBaseIDOrNone(M->BasePreprocessedEntityID,
4534                           M->NumPreprocessedEntities);
4535         writeBaseIDOrNone(M->BaseSubmoduleID, M->LocalNumSubmodules);
4536         writeBaseIDOrNone(M->BaseSelectorID, M->LocalNumSelectors);
4537         writeBaseIDOrNone(M->BaseDeclID, M->LocalNumDecls);
4538         writeBaseIDOrNone(M->BaseTypeIndex, M->LocalNumTypes);
4539       }
4540     }
4541     Record.clear();
4542     Record.push_back(MODULE_OFFSET_MAP);
4543     Stream.EmitRecordWithBlob(ModuleOffsetMapAbbrev, Record,
4544                               Buffer.data(), Buffer.size());
4545   }
4546 
4547   RecordData DeclUpdatesOffsetsRecord;
4548 
4549   // Keep writing types, declarations, and declaration update records
4550   // until we've emitted all of them.
4551   Stream.EnterSubblock(DECLTYPES_BLOCK_ID, /*bits for abbreviations*/5);
4552   WriteTypeAbbrevs();
4553   WriteDeclAbbrevs();
4554   for (DeclsToRewriteTy::iterator I = DeclsToRewrite.begin(),
4555                                   E = DeclsToRewrite.end();
4556        I != E; ++I)
4557     DeclTypesToEmit.push(const_cast<Decl*>(*I));
4558   do {
4559     WriteDeclUpdatesBlocks(DeclUpdatesOffsetsRecord);
4560     while (!DeclTypesToEmit.empty()) {
4561       DeclOrType DOT = DeclTypesToEmit.front();
4562       DeclTypesToEmit.pop();
4563       if (DOT.isType())
4564         WriteType(DOT.getType());
4565       else
4566         WriteDecl(Context, DOT.getDecl());
4567     }
4568   } while (!DeclUpdates.empty());
4569   Stream.ExitBlock();
4570 
4571   DoneWritingDeclsAndTypes = true;
4572 
4573   // These things can only be done once we've written out decls and types.
4574   WriteTypeDeclOffsets();
4575   if (!DeclUpdatesOffsetsRecord.empty())
4576     Stream.EmitRecord(DECL_UPDATE_OFFSETS, DeclUpdatesOffsetsRecord);
4577   WriteCXXBaseSpecifiersOffsets();
4578   WriteFileDeclIDsMap();
4579   WriteSourceManagerBlock(Context.getSourceManager(), PP);
4580 
4581   WriteComments();
4582   WritePreprocessor(PP, isModule);
4583   WriteHeaderSearch(PP.getHeaderSearchInfo());
4584   WriteSelectors(SemaRef);
4585   WriteReferencedSelectorsPool(SemaRef);
4586   WriteIdentifierTable(PP, SemaRef.IdResolver, isModule);
4587   WriteFPPragmaOptions(SemaRef.getFPOptions());
4588   WriteOpenCLExtensions(SemaRef);
4589   WritePragmaDiagnosticMappings(Context.getDiagnostics(), isModule);
4590 
4591   // If we're emitting a module, write out the submodule information.
4592   if (WritingModule)
4593     WriteSubmodules(WritingModule);
4594 
4595   Stream.EmitRecord(SPECIAL_TYPES, SpecialTypes);
4596 
4597   // Write the record containing external, unnamed definitions.
4598   if (!EagerlyDeserializedDecls.empty())
4599     Stream.EmitRecord(EAGERLY_DESERIALIZED_DECLS, EagerlyDeserializedDecls);
4600 
4601   // Write the record containing tentative definitions.
4602   if (!TentativeDefinitions.empty())
4603     Stream.EmitRecord(TENTATIVE_DEFINITIONS, TentativeDefinitions);
4604 
4605   // Write the record containing unused file scoped decls.
4606   if (!UnusedFileScopedDecls.empty())
4607     Stream.EmitRecord(UNUSED_FILESCOPED_DECLS, UnusedFileScopedDecls);
4608 
4609   // Write the record containing weak undeclared identifiers.
4610   if (!WeakUndeclaredIdentifiers.empty())
4611     Stream.EmitRecord(WEAK_UNDECLARED_IDENTIFIERS,
4612                       WeakUndeclaredIdentifiers);
4613 
4614   // Write the record containing locally-scoped extern "C" definitions.
4615   if (!LocallyScopedExternCDecls.empty())
4616     Stream.EmitRecord(LOCALLY_SCOPED_EXTERN_C_DECLS,
4617                       LocallyScopedExternCDecls);
4618 
4619   // Write the record containing ext_vector type names.
4620   if (!ExtVectorDecls.empty())
4621     Stream.EmitRecord(EXT_VECTOR_DECLS, ExtVectorDecls);
4622 
4623   // Write the record containing VTable uses information.
4624   if (!VTableUses.empty())
4625     Stream.EmitRecord(VTABLE_USES, VTableUses);
4626 
4627   // Write the record containing potentially unused local typedefs.
4628   if (!UnusedLocalTypedefNameCandidates.empty())
4629     Stream.EmitRecord(UNUSED_LOCAL_TYPEDEF_NAME_CANDIDATES,
4630                       UnusedLocalTypedefNameCandidates);
4631 
4632   // Write the record containing pending implicit instantiations.
4633   if (!PendingInstantiations.empty())
4634     Stream.EmitRecord(PENDING_IMPLICIT_INSTANTIATIONS, PendingInstantiations);
4635 
4636   // Write the record containing declaration references of Sema.
4637   if (!SemaDeclRefs.empty())
4638     Stream.EmitRecord(SEMA_DECL_REFS, SemaDeclRefs);
4639 
4640   // Write the record containing CUDA-specific declaration references.
4641   if (!CUDASpecialDeclRefs.empty())
4642     Stream.EmitRecord(CUDA_SPECIAL_DECL_REFS, CUDASpecialDeclRefs);
4643 
4644   // Write the delegating constructors.
4645   if (!DelegatingCtorDecls.empty())
4646     Stream.EmitRecord(DELEGATING_CTORS, DelegatingCtorDecls);
4647 
4648   // Write the known namespaces.
4649   if (!KnownNamespaces.empty())
4650     Stream.EmitRecord(KNOWN_NAMESPACES, KnownNamespaces);
4651 
4652   // Write the undefined internal functions and variables, and inline functions.
4653   if (!UndefinedButUsed.empty())
4654     Stream.EmitRecord(UNDEFINED_BUT_USED, UndefinedButUsed);
4655 
4656   // Write the visible updates to DeclContexts.
4657   for (auto *DC : UpdatedDeclContexts)
4658     WriteDeclContextVisibleUpdate(DC);
4659 
4660   if (!WritingModule) {
4661     // Write the submodules that were imported, if any.
4662     struct ModuleInfo {
4663       uint64_t ID;
4664       Module *M;
4665       ModuleInfo(uint64_t ID, Module *M) : ID(ID), M(M) {}
4666     };
4667     llvm::SmallVector<ModuleInfo, 64> Imports;
4668     for (const auto *I : Context.local_imports()) {
4669       assert(SubmoduleIDs.find(I->getImportedModule()) != SubmoduleIDs.end());
4670       Imports.push_back(ModuleInfo(SubmoduleIDs[I->getImportedModule()],
4671                          I->getImportedModule()));
4672     }
4673 
4674     if (!Imports.empty()) {
4675       auto Cmp = [](const ModuleInfo &A, const ModuleInfo &B) {
4676         return A.ID < B.ID;
4677       };
4678       auto Eq = [](const ModuleInfo &A, const ModuleInfo &B) {
4679         return A.ID == B.ID;
4680       };
4681 
4682       // Sort and deduplicate module IDs.
4683       std::sort(Imports.begin(), Imports.end(), Cmp);
4684       Imports.erase(std::unique(Imports.begin(), Imports.end(), Eq),
4685                     Imports.end());
4686 
4687       RecordData ImportedModules;
4688       for (const auto &Import : Imports) {
4689         ImportedModules.push_back(Import.ID);
4690         // FIXME: If the module has macros imported then later has declarations
4691         // imported, this location won't be the right one as a location for the
4692         // declaration imports.
4693         AddSourceLocation(Import.M->MacroVisibilityLoc, ImportedModules);
4694       }
4695 
4696       Stream.EmitRecord(IMPORTED_MODULES, ImportedModules);
4697     }
4698   }
4699 
4700   WriteDeclReplacementsBlock();
4701   WriteRedeclarations();
4702   WriteMergedDecls();
4703   WriteObjCCategories();
4704   WriteLateParsedTemplates(SemaRef);
4705   if(!WritingModule)
4706     WriteOptimizePragmaOptions(SemaRef);
4707 
4708   // Some simple statistics
4709   Record.clear();
4710   Record.push_back(NumStatements);
4711   Record.push_back(NumMacros);
4712   Record.push_back(NumLexicalDeclContexts);
4713   Record.push_back(NumVisibleDeclContexts);
4714   Stream.EmitRecord(STATISTICS, Record);
4715   Stream.ExitBlock();
4716 }
4717 
4718 void ASTWriter::WriteDeclUpdatesBlocks(RecordDataImpl &OffsetsRecord) {
4719   if (DeclUpdates.empty())
4720     return;
4721 
4722   DeclUpdateMap LocalUpdates;
4723   LocalUpdates.swap(DeclUpdates);
4724 
4725   for (auto &DeclUpdate : LocalUpdates) {
4726     const Decl *D = DeclUpdate.first;
4727     if (isRewritten(D))
4728       continue; // The decl will be written completely,no need to store updates.
4729 
4730     bool HasUpdatedBody = false;
4731     RecordData Record;
4732     for (auto &Update : DeclUpdate.second) {
4733       DeclUpdateKind Kind = (DeclUpdateKind)Update.getKind();
4734 
4735       Record.push_back(Kind);
4736       switch (Kind) {
4737       case UPD_CXX_ADDED_IMPLICIT_MEMBER:
4738       case UPD_CXX_ADDED_TEMPLATE_SPECIALIZATION:
4739       case UPD_CXX_ADDED_ANONYMOUS_NAMESPACE:
4740         assert(Update.getDecl() && "no decl to add?");
4741         Record.push_back(GetDeclRef(Update.getDecl()));
4742         break;
4743 
4744       case UPD_CXX_ADDED_FUNCTION_DEFINITION:
4745         // An updated body is emitted last, so that the reader doesn't need
4746         // to skip over the lazy body to reach statements for other records.
4747         Record.pop_back();
4748         HasUpdatedBody = true;
4749         break;
4750 
4751       case UPD_CXX_INSTANTIATED_STATIC_DATA_MEMBER:
4752         AddSourceLocation(Update.getLoc(), Record);
4753         break;
4754 
4755       case UPD_CXX_INSTANTIATED_CLASS_DEFINITION: {
4756         auto *RD = cast<CXXRecordDecl>(D);
4757         AddUpdatedDeclContext(RD->getPrimaryContext());
4758         AddCXXDefinitionData(RD, Record);
4759         Record.push_back(WriteDeclContextLexicalBlock(
4760             *Context, const_cast<CXXRecordDecl *>(RD)));
4761 
4762         // This state is sometimes updated by template instantiation, when we
4763         // switch from the specialization referring to the template declaration
4764         // to it referring to the template definition.
4765         if (auto *MSInfo = RD->getMemberSpecializationInfo()) {
4766           Record.push_back(MSInfo->getTemplateSpecializationKind());
4767           AddSourceLocation(MSInfo->getPointOfInstantiation(), Record);
4768         } else {
4769           auto *Spec = cast<ClassTemplateSpecializationDecl>(RD);
4770           Record.push_back(Spec->getTemplateSpecializationKind());
4771           AddSourceLocation(Spec->getPointOfInstantiation(), Record);
4772 
4773           // The instantiation might have been resolved to a partial
4774           // specialization. If so, record which one.
4775           auto From = Spec->getInstantiatedFrom();
4776           if (auto PartialSpec =
4777                 From.dyn_cast<ClassTemplatePartialSpecializationDecl*>()) {
4778             Record.push_back(true);
4779             AddDeclRef(PartialSpec, Record);
4780             AddTemplateArgumentList(&Spec->getTemplateInstantiationArgs(),
4781                                     Record);
4782           } else {
4783             Record.push_back(false);
4784           }
4785         }
4786         Record.push_back(RD->getTagKind());
4787         AddSourceLocation(RD->getLocation(), Record);
4788         AddSourceLocation(RD->getLocStart(), Record);
4789         AddSourceLocation(RD->getRBraceLoc(), Record);
4790 
4791         // Instantiation may change attributes; write them all out afresh.
4792         Record.push_back(D->hasAttrs());
4793         if (Record.back())
4794           WriteAttributes(llvm::makeArrayRef(D->getAttrs().begin(),
4795                                              D->getAttrs().size()), Record);
4796 
4797         // FIXME: Ensure we don't get here for explicit instantiations.
4798         break;
4799       }
4800 
4801       case UPD_CXX_RESOLVED_EXCEPTION_SPEC:
4802         addExceptionSpec(
4803             *this,
4804             cast<FunctionDecl>(D)->getType()->castAs<FunctionProtoType>(),
4805             Record);
4806         break;
4807 
4808       case UPD_CXX_DEDUCED_RETURN_TYPE:
4809         Record.push_back(GetOrCreateTypeID(Update.getType()));
4810         break;
4811 
4812       case UPD_DECL_MARKED_USED:
4813         break;
4814 
4815       case UPD_MANGLING_NUMBER:
4816       case UPD_STATIC_LOCAL_NUMBER:
4817         Record.push_back(Update.getNumber());
4818         break;
4819       case UPD_DECL_MARKED_OPENMP_THREADPRIVATE:
4820         AddSourceRange(D->getAttr<OMPThreadPrivateDeclAttr>()->getRange(),
4821                        Record);
4822         break;
4823       }
4824     }
4825 
4826     if (HasUpdatedBody) {
4827       const FunctionDecl *Def = cast<FunctionDecl>(D);
4828       Record.push_back(UPD_CXX_ADDED_FUNCTION_DEFINITION);
4829       Record.push_back(Def->isInlined());
4830       AddSourceLocation(Def->getInnerLocStart(), Record);
4831       AddFunctionDefinition(Def, Record);
4832       if (auto *DD = dyn_cast<CXXDestructorDecl>(Def))
4833         Record.push_back(GetDeclRef(DD->getOperatorDelete()));
4834     }
4835 
4836     OffsetsRecord.push_back(GetDeclRef(D));
4837     OffsetsRecord.push_back(Stream.GetCurrentBitNo());
4838 
4839     Stream.EmitRecord(DECL_UPDATES, Record);
4840 
4841     // Flush any statements that were written as part of this update record.
4842     FlushStmts();
4843 
4844     // Flush C++ base specifiers, if there are any.
4845     FlushCXXBaseSpecifiers();
4846   }
4847 }
4848 
4849 void ASTWriter::WriteDeclReplacementsBlock() {
4850   if (ReplacedDecls.empty())
4851     return;
4852 
4853   RecordData Record;
4854   for (SmallVectorImpl<ReplacedDeclInfo>::iterator
4855          I = ReplacedDecls.begin(), E = ReplacedDecls.end(); I != E; ++I) {
4856     Record.push_back(I->ID);
4857     Record.push_back(I->Offset);
4858     Record.push_back(I->Loc);
4859   }
4860   Stream.EmitRecord(DECL_REPLACEMENTS, Record);
4861 }
4862 
4863 void ASTWriter::AddSourceLocation(SourceLocation Loc, RecordDataImpl &Record) {
4864   Record.push_back(Loc.getRawEncoding());
4865 }
4866 
4867 void ASTWriter::AddSourceRange(SourceRange Range, RecordDataImpl &Record) {
4868   AddSourceLocation(Range.getBegin(), Record);
4869   AddSourceLocation(Range.getEnd(), Record);
4870 }
4871 
4872 void ASTWriter::AddAPInt(const llvm::APInt &Value, RecordDataImpl &Record) {
4873   Record.push_back(Value.getBitWidth());
4874   const uint64_t *Words = Value.getRawData();
4875   Record.append(Words, Words + Value.getNumWords());
4876 }
4877 
4878 void ASTWriter::AddAPSInt(const llvm::APSInt &Value, RecordDataImpl &Record) {
4879   Record.push_back(Value.isUnsigned());
4880   AddAPInt(Value, Record);
4881 }
4882 
4883 void ASTWriter::AddAPFloat(const llvm::APFloat &Value, RecordDataImpl &Record) {
4884   AddAPInt(Value.bitcastToAPInt(), Record);
4885 }
4886 
4887 void ASTWriter::AddIdentifierRef(const IdentifierInfo *II, RecordDataImpl &Record) {
4888   Record.push_back(getIdentifierRef(II));
4889 }
4890 
4891 IdentID ASTWriter::getIdentifierRef(const IdentifierInfo *II) {
4892   if (!II)
4893     return 0;
4894 
4895   IdentID &ID = IdentifierIDs[II];
4896   if (ID == 0)
4897     ID = NextIdentID++;
4898   return ID;
4899 }
4900 
4901 MacroID ASTWriter::getMacroRef(MacroInfo *MI, const IdentifierInfo *Name) {
4902   // Don't emit builtin macros like __LINE__ to the AST file unless they
4903   // have been redefined by the header (in which case they are not
4904   // isBuiltinMacro).
4905   if (!MI || MI->isBuiltinMacro())
4906     return 0;
4907 
4908   MacroID &ID = MacroIDs[MI];
4909   if (ID == 0) {
4910     ID = NextMacroID++;
4911     MacroInfoToEmitData Info = { Name, MI, ID };
4912     MacroInfosToEmit.push_back(Info);
4913   }
4914   return ID;
4915 }
4916 
4917 MacroID ASTWriter::getMacroID(MacroInfo *MI) {
4918   if (!MI || MI->isBuiltinMacro())
4919     return 0;
4920 
4921   assert(MacroIDs.find(MI) != MacroIDs.end() && "Macro not emitted!");
4922   return MacroIDs[MI];
4923 }
4924 
4925 uint64_t ASTWriter::getMacroDirectivesOffset(const IdentifierInfo *Name) {
4926   assert(IdentMacroDirectivesOffsetMap[Name] && "not set!");
4927   return IdentMacroDirectivesOffsetMap[Name];
4928 }
4929 
4930 void ASTWriter::AddSelectorRef(const Selector SelRef, RecordDataImpl &Record) {
4931   Record.push_back(getSelectorRef(SelRef));
4932 }
4933 
4934 SelectorID ASTWriter::getSelectorRef(Selector Sel) {
4935   if (Sel.getAsOpaquePtr() == nullptr) {
4936     return 0;
4937   }
4938 
4939   SelectorID SID = SelectorIDs[Sel];
4940   if (SID == 0 && Chain) {
4941     // This might trigger a ReadSelector callback, which will set the ID for
4942     // this selector.
4943     Chain->LoadSelector(Sel);
4944     SID = SelectorIDs[Sel];
4945   }
4946   if (SID == 0) {
4947     SID = NextSelectorID++;
4948     SelectorIDs[Sel] = SID;
4949   }
4950   return SID;
4951 }
4952 
4953 void ASTWriter::AddCXXTemporary(const CXXTemporary *Temp, RecordDataImpl &Record) {
4954   AddDeclRef(Temp->getDestructor(), Record);
4955 }
4956 
4957 void ASTWriter::AddCXXBaseSpecifiersRef(CXXBaseSpecifier const *Bases,
4958                                       CXXBaseSpecifier const *BasesEnd,
4959                                         RecordDataImpl &Record) {
4960   assert(Bases != BasesEnd && "Empty base-specifier sets are not recorded");
4961   CXXBaseSpecifiersToWrite.push_back(
4962                                 QueuedCXXBaseSpecifiers(NextCXXBaseSpecifiersID,
4963                                                         Bases, BasesEnd));
4964   Record.push_back(NextCXXBaseSpecifiersID++);
4965 }
4966 
4967 void ASTWriter::AddTemplateArgumentLocInfo(TemplateArgument::ArgKind Kind,
4968                                            const TemplateArgumentLocInfo &Arg,
4969                                            RecordDataImpl &Record) {
4970   switch (Kind) {
4971   case TemplateArgument::Expression:
4972     AddStmt(Arg.getAsExpr());
4973     break;
4974   case TemplateArgument::Type:
4975     AddTypeSourceInfo(Arg.getAsTypeSourceInfo(), Record);
4976     break;
4977   case TemplateArgument::Template:
4978     AddNestedNameSpecifierLoc(Arg.getTemplateQualifierLoc(), Record);
4979     AddSourceLocation(Arg.getTemplateNameLoc(), Record);
4980     break;
4981   case TemplateArgument::TemplateExpansion:
4982     AddNestedNameSpecifierLoc(Arg.getTemplateQualifierLoc(), Record);
4983     AddSourceLocation(Arg.getTemplateNameLoc(), Record);
4984     AddSourceLocation(Arg.getTemplateEllipsisLoc(), Record);
4985     break;
4986   case TemplateArgument::Null:
4987   case TemplateArgument::Integral:
4988   case TemplateArgument::Declaration:
4989   case TemplateArgument::NullPtr:
4990   case TemplateArgument::Pack:
4991     // FIXME: Is this right?
4992     break;
4993   }
4994 }
4995 
4996 void ASTWriter::AddTemplateArgumentLoc(const TemplateArgumentLoc &Arg,
4997                                        RecordDataImpl &Record) {
4998   AddTemplateArgument(Arg.getArgument(), Record);
4999 
5000   if (Arg.getArgument().getKind() == TemplateArgument::Expression) {
5001     bool InfoHasSameExpr
5002       = Arg.getArgument().getAsExpr() == Arg.getLocInfo().getAsExpr();
5003     Record.push_back(InfoHasSameExpr);
5004     if (InfoHasSameExpr)
5005       return; // Avoid storing the same expr twice.
5006   }
5007   AddTemplateArgumentLocInfo(Arg.getArgument().getKind(), Arg.getLocInfo(),
5008                              Record);
5009 }
5010 
5011 void ASTWriter::AddTypeSourceInfo(TypeSourceInfo *TInfo,
5012                                   RecordDataImpl &Record) {
5013   if (!TInfo) {
5014     AddTypeRef(QualType(), Record);
5015     return;
5016   }
5017 
5018   AddTypeLoc(TInfo->getTypeLoc(), Record);
5019 }
5020 
5021 void ASTWriter::AddTypeLoc(TypeLoc TL, RecordDataImpl &Record) {
5022   AddTypeRef(TL.getType(), Record);
5023 
5024   TypeLocWriter TLW(*this, Record);
5025   for (; !TL.isNull(); TL = TL.getNextTypeLoc())
5026     TLW.Visit(TL);
5027 }
5028 
5029 void ASTWriter::AddTypeRef(QualType T, RecordDataImpl &Record) {
5030   Record.push_back(GetOrCreateTypeID(T));
5031 }
5032 
5033 TypeID ASTWriter::GetOrCreateTypeID( QualType T) {
5034   assert(Context);
5035   return MakeTypeID(*Context, T,
5036               std::bind1st(std::mem_fun(&ASTWriter::GetOrCreateTypeIdx), this));
5037 }
5038 
5039 TypeID ASTWriter::getTypeID(QualType T) const {
5040   assert(Context);
5041   return MakeTypeID(*Context, T,
5042               std::bind1st(std::mem_fun(&ASTWriter::getTypeIdx), this));
5043 }
5044 
5045 TypeIdx ASTWriter::GetOrCreateTypeIdx(QualType T) {
5046   if (T.isNull())
5047     return TypeIdx();
5048   assert(!T.getLocalFastQualifiers());
5049 
5050   TypeIdx &Idx = TypeIdxs[T];
5051   if (Idx.getIndex() == 0) {
5052     if (DoneWritingDeclsAndTypes) {
5053       assert(0 && "New type seen after serializing all the types to emit!");
5054       return TypeIdx();
5055     }
5056 
5057     // We haven't seen this type before. Assign it a new ID and put it
5058     // into the queue of types to emit.
5059     Idx = TypeIdx(NextTypeID++);
5060     DeclTypesToEmit.push(T);
5061   }
5062   return Idx;
5063 }
5064 
5065 TypeIdx ASTWriter::getTypeIdx(QualType T) const {
5066   if (T.isNull())
5067     return TypeIdx();
5068   assert(!T.getLocalFastQualifiers());
5069 
5070   TypeIdxMap::const_iterator I = TypeIdxs.find(T);
5071   assert(I != TypeIdxs.end() && "Type not emitted!");
5072   return I->second;
5073 }
5074 
5075 void ASTWriter::AddDeclRef(const Decl *D, RecordDataImpl &Record) {
5076   Record.push_back(GetDeclRef(D));
5077 }
5078 
5079 DeclID ASTWriter::GetDeclRef(const Decl *D) {
5080   assert(WritingAST && "Cannot request a declaration ID before AST writing");
5081 
5082   if (!D) {
5083     return 0;
5084   }
5085 
5086   // If D comes from an AST file, its declaration ID is already known and
5087   // fixed.
5088   if (D->isFromASTFile())
5089     return D->getGlobalID();
5090 
5091   assert(!(reinterpret_cast<uintptr_t>(D) & 0x01) && "Invalid decl pointer");
5092   DeclID &ID = DeclIDs[D];
5093   if (ID == 0) {
5094     if (DoneWritingDeclsAndTypes) {
5095       assert(0 && "New decl seen after serializing all the decls to emit!");
5096       return 0;
5097     }
5098 
5099     // We haven't seen this declaration before. Give it a new ID and
5100     // enqueue it in the list of declarations to emit.
5101     ID = NextDeclID++;
5102     DeclTypesToEmit.push(const_cast<Decl *>(D));
5103   }
5104 
5105   return ID;
5106 }
5107 
5108 DeclID ASTWriter::getDeclID(const Decl *D) {
5109   if (!D)
5110     return 0;
5111 
5112   // If D comes from an AST file, its declaration ID is already known and
5113   // fixed.
5114   if (D->isFromASTFile())
5115     return D->getGlobalID();
5116 
5117   assert(DeclIDs.find(D) != DeclIDs.end() && "Declaration not emitted!");
5118   return DeclIDs[D];
5119 }
5120 
5121 void ASTWriter::associateDeclWithFile(const Decl *D, DeclID ID) {
5122   assert(ID);
5123   assert(D);
5124 
5125   SourceLocation Loc = D->getLocation();
5126   if (Loc.isInvalid())
5127     return;
5128 
5129   // We only keep track of the file-level declarations of each file.
5130   if (!D->getLexicalDeclContext()->isFileContext())
5131     return;
5132   // FIXME: ParmVarDecls that are part of a function type of a parameter of
5133   // a function/objc method, should not have TU as lexical context.
5134   if (isa<ParmVarDecl>(D))
5135     return;
5136 
5137   SourceManager &SM = Context->getSourceManager();
5138   SourceLocation FileLoc = SM.getFileLoc(Loc);
5139   assert(SM.isLocalSourceLocation(FileLoc));
5140   FileID FID;
5141   unsigned Offset;
5142   std::tie(FID, Offset) = SM.getDecomposedLoc(FileLoc);
5143   if (FID.isInvalid())
5144     return;
5145   assert(SM.getSLocEntry(FID).isFile());
5146 
5147   DeclIDInFileInfo *&Info = FileDeclIDs[FID];
5148   if (!Info)
5149     Info = new DeclIDInFileInfo();
5150 
5151   std::pair<unsigned, serialization::DeclID> LocDecl(Offset, ID);
5152   LocDeclIDsTy &Decls = Info->DeclIDs;
5153 
5154   if (Decls.empty() || Decls.back().first <= Offset) {
5155     Decls.push_back(LocDecl);
5156     return;
5157   }
5158 
5159   LocDeclIDsTy::iterator I =
5160       std::upper_bound(Decls.begin(), Decls.end(), LocDecl, llvm::less_first());
5161 
5162   Decls.insert(I, LocDecl);
5163 }
5164 
5165 void ASTWriter::AddDeclarationName(DeclarationName Name, RecordDataImpl &Record) {
5166   // FIXME: Emit a stable enum for NameKind.  0 = Identifier etc.
5167   Record.push_back(Name.getNameKind());
5168   switch (Name.getNameKind()) {
5169   case DeclarationName::Identifier:
5170     AddIdentifierRef(Name.getAsIdentifierInfo(), Record);
5171     break;
5172 
5173   case DeclarationName::ObjCZeroArgSelector:
5174   case DeclarationName::ObjCOneArgSelector:
5175   case DeclarationName::ObjCMultiArgSelector:
5176     AddSelectorRef(Name.getObjCSelector(), Record);
5177     break;
5178 
5179   case DeclarationName::CXXConstructorName:
5180   case DeclarationName::CXXDestructorName:
5181   case DeclarationName::CXXConversionFunctionName:
5182     AddTypeRef(Name.getCXXNameType(), Record);
5183     break;
5184 
5185   case DeclarationName::CXXOperatorName:
5186     Record.push_back(Name.getCXXOverloadedOperator());
5187     break;
5188 
5189   case DeclarationName::CXXLiteralOperatorName:
5190     AddIdentifierRef(Name.getCXXLiteralIdentifier(), Record);
5191     break;
5192 
5193   case DeclarationName::CXXUsingDirective:
5194     // No extra data to emit
5195     break;
5196   }
5197 }
5198 
5199 unsigned ASTWriter::getAnonymousDeclarationNumber(const NamedDecl *D) {
5200   assert(needsAnonymousDeclarationNumber(D) &&
5201          "expected an anonymous declaration");
5202 
5203   // Number the anonymous declarations within this context, if we've not
5204   // already done so.
5205   auto It = AnonymousDeclarationNumbers.find(D);
5206   if (It == AnonymousDeclarationNumbers.end()) {
5207     auto *DC = D->getLexicalDeclContext();
5208     numberAnonymousDeclsWithin(DC, [&](const NamedDecl *ND, unsigned Number) {
5209       AnonymousDeclarationNumbers[ND] = Number;
5210     });
5211 
5212     It = AnonymousDeclarationNumbers.find(D);
5213     assert(It != AnonymousDeclarationNumbers.end() &&
5214            "declaration not found within its lexical context");
5215   }
5216 
5217   return It->second;
5218 }
5219 
5220 void ASTWriter::AddDeclarationNameLoc(const DeclarationNameLoc &DNLoc,
5221                                      DeclarationName Name, RecordDataImpl &Record) {
5222   switch (Name.getNameKind()) {
5223   case DeclarationName::CXXConstructorName:
5224   case DeclarationName::CXXDestructorName:
5225   case DeclarationName::CXXConversionFunctionName:
5226     AddTypeSourceInfo(DNLoc.NamedType.TInfo, Record);
5227     break;
5228 
5229   case DeclarationName::CXXOperatorName:
5230     AddSourceLocation(
5231        SourceLocation::getFromRawEncoding(DNLoc.CXXOperatorName.BeginOpNameLoc),
5232        Record);
5233     AddSourceLocation(
5234         SourceLocation::getFromRawEncoding(DNLoc.CXXOperatorName.EndOpNameLoc),
5235         Record);
5236     break;
5237 
5238   case DeclarationName::CXXLiteralOperatorName:
5239     AddSourceLocation(
5240      SourceLocation::getFromRawEncoding(DNLoc.CXXLiteralOperatorName.OpNameLoc),
5241      Record);
5242     break;
5243 
5244   case DeclarationName::Identifier:
5245   case DeclarationName::ObjCZeroArgSelector:
5246   case DeclarationName::ObjCOneArgSelector:
5247   case DeclarationName::ObjCMultiArgSelector:
5248   case DeclarationName::CXXUsingDirective:
5249     break;
5250   }
5251 }
5252 
5253 void ASTWriter::AddDeclarationNameInfo(const DeclarationNameInfo &NameInfo,
5254                                        RecordDataImpl &Record) {
5255   AddDeclarationName(NameInfo.getName(), Record);
5256   AddSourceLocation(NameInfo.getLoc(), Record);
5257   AddDeclarationNameLoc(NameInfo.getInfo(), NameInfo.getName(), Record);
5258 }
5259 
5260 void ASTWriter::AddQualifierInfo(const QualifierInfo &Info,
5261                                  RecordDataImpl &Record) {
5262   AddNestedNameSpecifierLoc(Info.QualifierLoc, Record);
5263   Record.push_back(Info.NumTemplParamLists);
5264   for (unsigned i=0, e=Info.NumTemplParamLists; i != e; ++i)
5265     AddTemplateParameterList(Info.TemplParamLists[i], Record);
5266 }
5267 
5268 void ASTWriter::AddNestedNameSpecifier(NestedNameSpecifier *NNS,
5269                                        RecordDataImpl &Record) {
5270   // Nested name specifiers usually aren't too long. I think that 8 would
5271   // typically accommodate the vast majority.
5272   SmallVector<NestedNameSpecifier *, 8> NestedNames;
5273 
5274   // Push each of the NNS's onto a stack for serialization in reverse order.
5275   while (NNS) {
5276     NestedNames.push_back(NNS);
5277     NNS = NNS->getPrefix();
5278   }
5279 
5280   Record.push_back(NestedNames.size());
5281   while(!NestedNames.empty()) {
5282     NNS = NestedNames.pop_back_val();
5283     NestedNameSpecifier::SpecifierKind Kind = NNS->getKind();
5284     Record.push_back(Kind);
5285     switch (Kind) {
5286     case NestedNameSpecifier::Identifier:
5287       AddIdentifierRef(NNS->getAsIdentifier(), Record);
5288       break;
5289 
5290     case NestedNameSpecifier::Namespace:
5291       AddDeclRef(NNS->getAsNamespace(), Record);
5292       break;
5293 
5294     case NestedNameSpecifier::NamespaceAlias:
5295       AddDeclRef(NNS->getAsNamespaceAlias(), Record);
5296       break;
5297 
5298     case NestedNameSpecifier::TypeSpec:
5299     case NestedNameSpecifier::TypeSpecWithTemplate:
5300       AddTypeRef(QualType(NNS->getAsType(), 0), Record);
5301       Record.push_back(Kind == NestedNameSpecifier::TypeSpecWithTemplate);
5302       break;
5303 
5304     case NestedNameSpecifier::Global:
5305       // Don't need to write an associated value.
5306       break;
5307 
5308     case NestedNameSpecifier::Super:
5309       AddDeclRef(NNS->getAsRecordDecl(), Record);
5310       break;
5311     }
5312   }
5313 }
5314 
5315 void ASTWriter::AddNestedNameSpecifierLoc(NestedNameSpecifierLoc NNS,
5316                                           RecordDataImpl &Record) {
5317   // Nested name specifiers usually aren't too long. I think that 8 would
5318   // typically accommodate the vast majority.
5319   SmallVector<NestedNameSpecifierLoc , 8> NestedNames;
5320 
5321   // Push each of the nested-name-specifiers's onto a stack for
5322   // serialization in reverse order.
5323   while (NNS) {
5324     NestedNames.push_back(NNS);
5325     NNS = NNS.getPrefix();
5326   }
5327 
5328   Record.push_back(NestedNames.size());
5329   while(!NestedNames.empty()) {
5330     NNS = NestedNames.pop_back_val();
5331     NestedNameSpecifier::SpecifierKind Kind
5332       = NNS.getNestedNameSpecifier()->getKind();
5333     Record.push_back(Kind);
5334     switch (Kind) {
5335     case NestedNameSpecifier::Identifier:
5336       AddIdentifierRef(NNS.getNestedNameSpecifier()->getAsIdentifier(), Record);
5337       AddSourceRange(NNS.getLocalSourceRange(), Record);
5338       break;
5339 
5340     case NestedNameSpecifier::Namespace:
5341       AddDeclRef(NNS.getNestedNameSpecifier()->getAsNamespace(), Record);
5342       AddSourceRange(NNS.getLocalSourceRange(), Record);
5343       break;
5344 
5345     case NestedNameSpecifier::NamespaceAlias:
5346       AddDeclRef(NNS.getNestedNameSpecifier()->getAsNamespaceAlias(), Record);
5347       AddSourceRange(NNS.getLocalSourceRange(), Record);
5348       break;
5349 
5350     case NestedNameSpecifier::TypeSpec:
5351     case NestedNameSpecifier::TypeSpecWithTemplate:
5352       Record.push_back(Kind == NestedNameSpecifier::TypeSpecWithTemplate);
5353       AddTypeLoc(NNS.getTypeLoc(), Record);
5354       AddSourceLocation(NNS.getLocalSourceRange().getEnd(), Record);
5355       break;
5356 
5357     case NestedNameSpecifier::Global:
5358       AddSourceLocation(NNS.getLocalSourceRange().getEnd(), Record);
5359       break;
5360 
5361     case NestedNameSpecifier::Super:
5362       AddDeclRef(NNS.getNestedNameSpecifier()->getAsRecordDecl(), Record);
5363       AddSourceRange(NNS.getLocalSourceRange(), Record);
5364       break;
5365     }
5366   }
5367 }
5368 
5369 void ASTWriter::AddTemplateName(TemplateName Name, RecordDataImpl &Record) {
5370   TemplateName::NameKind Kind = Name.getKind();
5371   Record.push_back(Kind);
5372   switch (Kind) {
5373   case TemplateName::Template:
5374     AddDeclRef(Name.getAsTemplateDecl(), Record);
5375     break;
5376 
5377   case TemplateName::OverloadedTemplate: {
5378     OverloadedTemplateStorage *OvT = Name.getAsOverloadedTemplate();
5379     Record.push_back(OvT->size());
5380     for (OverloadedTemplateStorage::iterator I = OvT->begin(), E = OvT->end();
5381            I != E; ++I)
5382       AddDeclRef(*I, Record);
5383     break;
5384   }
5385 
5386   case TemplateName::QualifiedTemplate: {
5387     QualifiedTemplateName *QualT = Name.getAsQualifiedTemplateName();
5388     AddNestedNameSpecifier(QualT->getQualifier(), Record);
5389     Record.push_back(QualT->hasTemplateKeyword());
5390     AddDeclRef(QualT->getTemplateDecl(), Record);
5391     break;
5392   }
5393 
5394   case TemplateName::DependentTemplate: {
5395     DependentTemplateName *DepT = Name.getAsDependentTemplateName();
5396     AddNestedNameSpecifier(DepT->getQualifier(), Record);
5397     Record.push_back(DepT->isIdentifier());
5398     if (DepT->isIdentifier())
5399       AddIdentifierRef(DepT->getIdentifier(), Record);
5400     else
5401       Record.push_back(DepT->getOperator());
5402     break;
5403   }
5404 
5405   case TemplateName::SubstTemplateTemplateParm: {
5406     SubstTemplateTemplateParmStorage *subst
5407       = Name.getAsSubstTemplateTemplateParm();
5408     AddDeclRef(subst->getParameter(), Record);
5409     AddTemplateName(subst->getReplacement(), Record);
5410     break;
5411   }
5412 
5413   case TemplateName::SubstTemplateTemplateParmPack: {
5414     SubstTemplateTemplateParmPackStorage *SubstPack
5415       = Name.getAsSubstTemplateTemplateParmPack();
5416     AddDeclRef(SubstPack->getParameterPack(), Record);
5417     AddTemplateArgument(SubstPack->getArgumentPack(), Record);
5418     break;
5419   }
5420   }
5421 }
5422 
5423 void ASTWriter::AddTemplateArgument(const TemplateArgument &Arg,
5424                                     RecordDataImpl &Record) {
5425   Record.push_back(Arg.getKind());
5426   switch (Arg.getKind()) {
5427   case TemplateArgument::Null:
5428     break;
5429   case TemplateArgument::Type:
5430     AddTypeRef(Arg.getAsType(), Record);
5431     break;
5432   case TemplateArgument::Declaration:
5433     AddDeclRef(Arg.getAsDecl(), Record);
5434     AddTypeRef(Arg.getParamTypeForDecl(), Record);
5435     break;
5436   case TemplateArgument::NullPtr:
5437     AddTypeRef(Arg.getNullPtrType(), Record);
5438     break;
5439   case TemplateArgument::Integral:
5440     AddAPSInt(Arg.getAsIntegral(), Record);
5441     AddTypeRef(Arg.getIntegralType(), Record);
5442     break;
5443   case TemplateArgument::Template:
5444     AddTemplateName(Arg.getAsTemplateOrTemplatePattern(), Record);
5445     break;
5446   case TemplateArgument::TemplateExpansion:
5447     AddTemplateName(Arg.getAsTemplateOrTemplatePattern(), Record);
5448     if (Optional<unsigned> NumExpansions = Arg.getNumTemplateExpansions())
5449       Record.push_back(*NumExpansions + 1);
5450     else
5451       Record.push_back(0);
5452     break;
5453   case TemplateArgument::Expression:
5454     AddStmt(Arg.getAsExpr());
5455     break;
5456   case TemplateArgument::Pack:
5457     Record.push_back(Arg.pack_size());
5458     for (const auto &P : Arg.pack_elements())
5459       AddTemplateArgument(P, Record);
5460     break;
5461   }
5462 }
5463 
5464 void
5465 ASTWriter::AddTemplateParameterList(const TemplateParameterList *TemplateParams,
5466                                     RecordDataImpl &Record) {
5467   assert(TemplateParams && "No TemplateParams!");
5468   AddSourceLocation(TemplateParams->getTemplateLoc(), Record);
5469   AddSourceLocation(TemplateParams->getLAngleLoc(), Record);
5470   AddSourceLocation(TemplateParams->getRAngleLoc(), Record);
5471   Record.push_back(TemplateParams->size());
5472   for (TemplateParameterList::const_iterator
5473          P = TemplateParams->begin(), PEnd = TemplateParams->end();
5474          P != PEnd; ++P)
5475     AddDeclRef(*P, Record);
5476 }
5477 
5478 /// \brief Emit a template argument list.
5479 void
5480 ASTWriter::AddTemplateArgumentList(const TemplateArgumentList *TemplateArgs,
5481                                    RecordDataImpl &Record) {
5482   assert(TemplateArgs && "No TemplateArgs!");
5483   Record.push_back(TemplateArgs->size());
5484   for (int i=0, e = TemplateArgs->size(); i != e; ++i)
5485     AddTemplateArgument(TemplateArgs->get(i), Record);
5486 }
5487 
5488 void
5489 ASTWriter::AddASTTemplateArgumentListInfo
5490 (const ASTTemplateArgumentListInfo *ASTTemplArgList, RecordDataImpl &Record) {
5491   assert(ASTTemplArgList && "No ASTTemplArgList!");
5492   AddSourceLocation(ASTTemplArgList->LAngleLoc, Record);
5493   AddSourceLocation(ASTTemplArgList->RAngleLoc, Record);
5494   Record.push_back(ASTTemplArgList->NumTemplateArgs);
5495   const TemplateArgumentLoc *TemplArgs = ASTTemplArgList->getTemplateArgs();
5496   for (int i=0, e = ASTTemplArgList->NumTemplateArgs; i != e; ++i)
5497     AddTemplateArgumentLoc(TemplArgs[i], Record);
5498 }
5499 
5500 void
5501 ASTWriter::AddUnresolvedSet(const ASTUnresolvedSet &Set, RecordDataImpl &Record) {
5502   Record.push_back(Set.size());
5503   for (ASTUnresolvedSet::const_iterator
5504          I = Set.begin(), E = Set.end(); I != E; ++I) {
5505     AddDeclRef(I.getDecl(), Record);
5506     Record.push_back(I.getAccess());
5507   }
5508 }
5509 
5510 void ASTWriter::AddCXXBaseSpecifier(const CXXBaseSpecifier &Base,
5511                                     RecordDataImpl &Record) {
5512   Record.push_back(Base.isVirtual());
5513   Record.push_back(Base.isBaseOfClass());
5514   Record.push_back(Base.getAccessSpecifierAsWritten());
5515   Record.push_back(Base.getInheritConstructors());
5516   AddTypeSourceInfo(Base.getTypeSourceInfo(), Record);
5517   AddSourceRange(Base.getSourceRange(), Record);
5518   AddSourceLocation(Base.isPackExpansion()? Base.getEllipsisLoc()
5519                                           : SourceLocation(),
5520                     Record);
5521 }
5522 
5523 void ASTWriter::FlushCXXBaseSpecifiers() {
5524   RecordData Record;
5525   for (unsigned I = 0, N = CXXBaseSpecifiersToWrite.size(); I != N; ++I) {
5526     Record.clear();
5527 
5528     // Record the offset of this base-specifier set.
5529     unsigned Index = CXXBaseSpecifiersToWrite[I].ID - 1;
5530     if (Index == CXXBaseSpecifiersOffsets.size())
5531       CXXBaseSpecifiersOffsets.push_back(Stream.GetCurrentBitNo());
5532     else {
5533       if (Index > CXXBaseSpecifiersOffsets.size())
5534         CXXBaseSpecifiersOffsets.resize(Index + 1);
5535       CXXBaseSpecifiersOffsets[Index] = Stream.GetCurrentBitNo();
5536     }
5537 
5538     const CXXBaseSpecifier *B = CXXBaseSpecifiersToWrite[I].Bases,
5539                         *BEnd = CXXBaseSpecifiersToWrite[I].BasesEnd;
5540     Record.push_back(BEnd - B);
5541     for (; B != BEnd; ++B)
5542       AddCXXBaseSpecifier(*B, Record);
5543     Stream.EmitRecord(serialization::DECL_CXX_BASE_SPECIFIERS, Record);
5544 
5545     // Flush any expressions that were written as part of the base specifiers.
5546     FlushStmts();
5547   }
5548 
5549   CXXBaseSpecifiersToWrite.clear();
5550 }
5551 
5552 void ASTWriter::AddCXXCtorInitializers(
5553                              const CXXCtorInitializer * const *CtorInitializers,
5554                              unsigned NumCtorInitializers,
5555                              RecordDataImpl &Record) {
5556   Record.push_back(NumCtorInitializers);
5557   for (unsigned i=0; i != NumCtorInitializers; ++i) {
5558     const CXXCtorInitializer *Init = CtorInitializers[i];
5559 
5560     if (Init->isBaseInitializer()) {
5561       Record.push_back(CTOR_INITIALIZER_BASE);
5562       AddTypeSourceInfo(Init->getTypeSourceInfo(), Record);
5563       Record.push_back(Init->isBaseVirtual());
5564     } else if (Init->isDelegatingInitializer()) {
5565       Record.push_back(CTOR_INITIALIZER_DELEGATING);
5566       AddTypeSourceInfo(Init->getTypeSourceInfo(), Record);
5567     } else if (Init->isMemberInitializer()){
5568       Record.push_back(CTOR_INITIALIZER_MEMBER);
5569       AddDeclRef(Init->getMember(), Record);
5570     } else {
5571       Record.push_back(CTOR_INITIALIZER_INDIRECT_MEMBER);
5572       AddDeclRef(Init->getIndirectMember(), Record);
5573     }
5574 
5575     AddSourceLocation(Init->getMemberLocation(), Record);
5576     AddStmt(Init->getInit());
5577     AddSourceLocation(Init->getLParenLoc(), Record);
5578     AddSourceLocation(Init->getRParenLoc(), Record);
5579     Record.push_back(Init->isWritten());
5580     if (Init->isWritten()) {
5581       Record.push_back(Init->getSourceOrder());
5582     } else {
5583       Record.push_back(Init->getNumArrayIndices());
5584       for (unsigned i=0, e=Init->getNumArrayIndices(); i != e; ++i)
5585         AddDeclRef(Init->getArrayIndex(i), Record);
5586     }
5587   }
5588 }
5589 
5590 void ASTWriter::AddCXXDefinitionData(const CXXRecordDecl *D, RecordDataImpl &Record) {
5591   auto &Data = D->data();
5592   Record.push_back(Data.IsLambda);
5593   Record.push_back(Data.UserDeclaredConstructor);
5594   Record.push_back(Data.UserDeclaredSpecialMembers);
5595   Record.push_back(Data.Aggregate);
5596   Record.push_back(Data.PlainOldData);
5597   Record.push_back(Data.Empty);
5598   Record.push_back(Data.Polymorphic);
5599   Record.push_back(Data.Abstract);
5600   Record.push_back(Data.IsStandardLayout);
5601   Record.push_back(Data.HasNoNonEmptyBases);
5602   Record.push_back(Data.HasPrivateFields);
5603   Record.push_back(Data.HasProtectedFields);
5604   Record.push_back(Data.HasPublicFields);
5605   Record.push_back(Data.HasMutableFields);
5606   Record.push_back(Data.HasVariantMembers);
5607   Record.push_back(Data.HasOnlyCMembers);
5608   Record.push_back(Data.HasInClassInitializer);
5609   Record.push_back(Data.HasUninitializedReferenceMember);
5610   Record.push_back(Data.NeedOverloadResolutionForMoveConstructor);
5611   Record.push_back(Data.NeedOverloadResolutionForMoveAssignment);
5612   Record.push_back(Data.NeedOverloadResolutionForDestructor);
5613   Record.push_back(Data.DefaultedMoveConstructorIsDeleted);
5614   Record.push_back(Data.DefaultedMoveAssignmentIsDeleted);
5615   Record.push_back(Data.DefaultedDestructorIsDeleted);
5616   Record.push_back(Data.HasTrivialSpecialMembers);
5617   Record.push_back(Data.DeclaredNonTrivialSpecialMembers);
5618   Record.push_back(Data.HasIrrelevantDestructor);
5619   Record.push_back(Data.HasConstexprNonCopyMoveConstructor);
5620   Record.push_back(Data.DefaultedDefaultConstructorIsConstexpr);
5621   Record.push_back(Data.HasConstexprDefaultConstructor);
5622   Record.push_back(Data.HasNonLiteralTypeFieldsOrBases);
5623   Record.push_back(Data.ComputedVisibleConversions);
5624   Record.push_back(Data.UserProvidedDefaultConstructor);
5625   Record.push_back(Data.DeclaredSpecialMembers);
5626   Record.push_back(Data.ImplicitCopyConstructorHasConstParam);
5627   Record.push_back(Data.ImplicitCopyAssignmentHasConstParam);
5628   Record.push_back(Data.HasDeclaredCopyConstructorWithConstParam);
5629   Record.push_back(Data.HasDeclaredCopyAssignmentWithConstParam);
5630   // IsLambda bit is already saved.
5631 
5632   Record.push_back(Data.NumBases);
5633   if (Data.NumBases > 0)
5634     AddCXXBaseSpecifiersRef(Data.getBases(), Data.getBases() + Data.NumBases,
5635                             Record);
5636 
5637   // FIXME: Make VBases lazily computed when needed to avoid storing them.
5638   Record.push_back(Data.NumVBases);
5639   if (Data.NumVBases > 0)
5640     AddCXXBaseSpecifiersRef(Data.getVBases(), Data.getVBases() + Data.NumVBases,
5641                             Record);
5642 
5643   AddUnresolvedSet(Data.Conversions.get(*Context), Record);
5644   AddUnresolvedSet(Data.VisibleConversions.get(*Context), Record);
5645   // Data.Definition is the owning decl, no need to write it.
5646   AddDeclRef(D->getFirstFriend(), Record);
5647 
5648   // Add lambda-specific data.
5649   if (Data.IsLambda) {
5650     auto &Lambda = D->getLambdaData();
5651     Record.push_back(Lambda.Dependent);
5652     Record.push_back(Lambda.IsGenericLambda);
5653     Record.push_back(Lambda.CaptureDefault);
5654     Record.push_back(Lambda.NumCaptures);
5655     Record.push_back(Lambda.NumExplicitCaptures);
5656     Record.push_back(Lambda.ManglingNumber);
5657     AddDeclRef(Lambda.ContextDecl, Record);
5658     AddTypeSourceInfo(Lambda.MethodTyInfo, Record);
5659     for (unsigned I = 0, N = Lambda.NumCaptures; I != N; ++I) {
5660       const LambdaCapture &Capture = Lambda.Captures[I];
5661       AddSourceLocation(Capture.getLocation(), Record);
5662       Record.push_back(Capture.isImplicit());
5663       Record.push_back(Capture.getCaptureKind());
5664       switch (Capture.getCaptureKind()) {
5665       case LCK_This:
5666       case LCK_VLAType:
5667         break;
5668       case LCK_ByCopy:
5669       case LCK_ByRef:
5670         VarDecl *Var =
5671             Capture.capturesVariable() ? Capture.getCapturedVar() : nullptr;
5672         AddDeclRef(Var, Record);
5673         AddSourceLocation(Capture.isPackExpansion() ? Capture.getEllipsisLoc()
5674                                                     : SourceLocation(),
5675                           Record);
5676         break;
5677       }
5678     }
5679   }
5680 }
5681 
5682 void ASTWriter::ReaderInitialized(ASTReader *Reader) {
5683   assert(Reader && "Cannot remove chain");
5684   assert((!Chain || Chain == Reader) && "Cannot replace chain");
5685   assert(FirstDeclID == NextDeclID &&
5686          FirstTypeID == NextTypeID &&
5687          FirstIdentID == NextIdentID &&
5688          FirstMacroID == NextMacroID &&
5689          FirstSubmoduleID == NextSubmoduleID &&
5690          FirstSelectorID == NextSelectorID &&
5691          "Setting chain after writing has started.");
5692 
5693   Chain = Reader;
5694 
5695   FirstDeclID = NUM_PREDEF_DECL_IDS + Chain->getTotalNumDecls();
5696   FirstTypeID = NUM_PREDEF_TYPE_IDS + Chain->getTotalNumTypes();
5697   FirstIdentID = NUM_PREDEF_IDENT_IDS + Chain->getTotalNumIdentifiers();
5698   FirstMacroID = NUM_PREDEF_MACRO_IDS + Chain->getTotalNumMacros();
5699   FirstSubmoduleID = NUM_PREDEF_SUBMODULE_IDS + Chain->getTotalNumSubmodules();
5700   FirstSelectorID = NUM_PREDEF_SELECTOR_IDS + Chain->getTotalNumSelectors();
5701   NextDeclID = FirstDeclID;
5702   NextTypeID = FirstTypeID;
5703   NextIdentID = FirstIdentID;
5704   NextMacroID = FirstMacroID;
5705   NextSelectorID = FirstSelectorID;
5706   NextSubmoduleID = FirstSubmoduleID;
5707 }
5708 
5709 void ASTWriter::IdentifierRead(IdentID ID, IdentifierInfo *II) {
5710   // Always keep the highest ID. See \p TypeRead() for more information.
5711   IdentID &StoredID = IdentifierIDs[II];
5712   if (ID > StoredID)
5713     StoredID = ID;
5714 }
5715 
5716 void ASTWriter::MacroRead(serialization::MacroID ID, MacroInfo *MI) {
5717   // Always keep the highest ID. See \p TypeRead() for more information.
5718   MacroID &StoredID = MacroIDs[MI];
5719   if (ID > StoredID)
5720     StoredID = ID;
5721 }
5722 
5723 void ASTWriter::TypeRead(TypeIdx Idx, QualType T) {
5724   // Always take the highest-numbered type index. This copes with an interesting
5725   // case for chained AST writing where we schedule writing the type and then,
5726   // later, deserialize the type from another AST. In this case, we want to
5727   // keep the higher-numbered entry so that we can properly write it out to
5728   // the AST file.
5729   TypeIdx &StoredIdx = TypeIdxs[T];
5730   if (Idx.getIndex() >= StoredIdx.getIndex())
5731     StoredIdx = Idx;
5732 }
5733 
5734 void ASTWriter::SelectorRead(SelectorID ID, Selector S) {
5735   // Always keep the highest ID. See \p TypeRead() for more information.
5736   SelectorID &StoredID = SelectorIDs[S];
5737   if (ID > StoredID)
5738     StoredID = ID;
5739 }
5740 
5741 void ASTWriter::MacroDefinitionRead(serialization::PreprocessedEntityID ID,
5742                                     MacroDefinition *MD) {
5743   assert(MacroDefinitions.find(MD) == MacroDefinitions.end());
5744   MacroDefinitions[MD] = ID;
5745 }
5746 
5747 void ASTWriter::ModuleRead(serialization::SubmoduleID ID, Module *Mod) {
5748   assert(SubmoduleIDs.find(Mod) == SubmoduleIDs.end());
5749   SubmoduleIDs[Mod] = ID;
5750 }
5751 
5752 void ASTWriter::CompletedTagDefinition(const TagDecl *D) {
5753   assert(D->isCompleteDefinition());
5754   assert(!WritingAST && "Already writing the AST!");
5755   if (const CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(D)) {
5756     // We are interested when a PCH decl is modified.
5757     if (RD->isFromASTFile()) {
5758       // A forward reference was mutated into a definition. Rewrite it.
5759       // FIXME: This happens during template instantiation, should we
5760       // have created a new definition decl instead ?
5761       assert(isTemplateInstantiation(RD->getTemplateSpecializationKind()) &&
5762              "completed a tag from another module but not by instantiation?");
5763       DeclUpdates[RD].push_back(
5764           DeclUpdate(UPD_CXX_INSTANTIATED_CLASS_DEFINITION));
5765     }
5766   }
5767 }
5768 
5769 void ASTWriter::AddedVisibleDecl(const DeclContext *DC, const Decl *D) {
5770   // TU and namespaces are handled elsewhere.
5771   if (isa<TranslationUnitDecl>(DC) || isa<NamespaceDecl>(DC))
5772     return;
5773 
5774   if (!(!D->isFromASTFile() && cast<Decl>(DC)->isFromASTFile()))
5775     return; // Not a source decl added to a DeclContext from PCH.
5776 
5777   assert(!getDefinitiveDeclContext(DC) && "DeclContext not definitive!");
5778   assert(!WritingAST && "Already writing the AST!");
5779   AddUpdatedDeclContext(DC);
5780   UpdatingVisibleDecls.push_back(D);
5781 }
5782 
5783 void ASTWriter::AddedCXXImplicitMember(const CXXRecordDecl *RD, const Decl *D) {
5784   assert(D->isImplicit());
5785   if (!(!D->isFromASTFile() && RD->isFromASTFile()))
5786     return; // Not a source member added to a class from PCH.
5787   if (!isa<CXXMethodDecl>(D))
5788     return; // We are interested in lazily declared implicit methods.
5789 
5790   // A decl coming from PCH was modified.
5791   assert(RD->isCompleteDefinition());
5792   assert(!WritingAST && "Already writing the AST!");
5793   DeclUpdates[RD].push_back(DeclUpdate(UPD_CXX_ADDED_IMPLICIT_MEMBER, D));
5794 }
5795 
5796 void ASTWriter::AddedCXXTemplateSpecialization(const ClassTemplateDecl *TD,
5797                                      const ClassTemplateSpecializationDecl *D) {
5798   // The specializations set is kept in the canonical template.
5799   TD = TD->getCanonicalDecl();
5800   if (!(!D->isFromASTFile() && TD->isFromASTFile()))
5801     return; // Not a source specialization added to a template from PCH.
5802 
5803   assert(!WritingAST && "Already writing the AST!");
5804   DeclUpdates[TD].push_back(DeclUpdate(UPD_CXX_ADDED_TEMPLATE_SPECIALIZATION,
5805                                        D));
5806 }
5807 
5808 void ASTWriter::AddedCXXTemplateSpecialization(
5809     const VarTemplateDecl *TD, const VarTemplateSpecializationDecl *D) {
5810   // The specializations set is kept in the canonical template.
5811   TD = TD->getCanonicalDecl();
5812   if (!(!D->isFromASTFile() && TD->isFromASTFile()))
5813     return; // Not a source specialization added to a template from PCH.
5814 
5815   assert(!WritingAST && "Already writing the AST!");
5816   DeclUpdates[TD].push_back(DeclUpdate(UPD_CXX_ADDED_TEMPLATE_SPECIALIZATION,
5817                                        D));
5818 }
5819 
5820 void ASTWriter::AddedCXXTemplateSpecialization(const FunctionTemplateDecl *TD,
5821                                                const FunctionDecl *D) {
5822   // The specializations set is kept in the canonical template.
5823   TD = TD->getCanonicalDecl();
5824   if (!(!D->isFromASTFile() && TD->isFromASTFile()))
5825     return; // Not a source specialization added to a template from PCH.
5826 
5827   assert(!WritingAST && "Already writing the AST!");
5828   DeclUpdates[TD].push_back(DeclUpdate(UPD_CXX_ADDED_TEMPLATE_SPECIALIZATION,
5829                                        D));
5830 }
5831 
5832 void ASTWriter::ResolvedExceptionSpec(const FunctionDecl *FD) {
5833   assert(!WritingAST && "Already writing the AST!");
5834   FD = FD->getCanonicalDecl();
5835   if (!FD->isFromASTFile())
5836     return; // Not a function declared in PCH and defined outside.
5837 
5838   DeclUpdates[FD].push_back(UPD_CXX_RESOLVED_EXCEPTION_SPEC);
5839 }
5840 
5841 void ASTWriter::DeducedReturnType(const FunctionDecl *FD, QualType ReturnType) {
5842   assert(!WritingAST && "Already writing the AST!");
5843   FD = FD->getCanonicalDecl();
5844   if (!FD->isFromASTFile())
5845     return; // Not a function declared in PCH and defined outside.
5846 
5847   DeclUpdates[FD].push_back(DeclUpdate(UPD_CXX_DEDUCED_RETURN_TYPE, ReturnType));
5848 }
5849 
5850 void ASTWriter::CompletedImplicitDefinition(const FunctionDecl *D) {
5851   assert(!WritingAST && "Already writing the AST!");
5852   if (!D->isFromASTFile())
5853     return; // Declaration not imported from PCH.
5854 
5855   // Implicit function decl from a PCH was defined.
5856   DeclUpdates[D].push_back(DeclUpdate(UPD_CXX_ADDED_FUNCTION_DEFINITION));
5857 }
5858 
5859 void ASTWriter::FunctionDefinitionInstantiated(const FunctionDecl *D) {
5860   assert(!WritingAST && "Already writing the AST!");
5861   if (!D->isFromASTFile())
5862     return;
5863 
5864   DeclUpdates[D].push_back(
5865       DeclUpdate(UPD_CXX_ADDED_FUNCTION_DEFINITION));
5866 }
5867 
5868 void ASTWriter::StaticDataMemberInstantiated(const VarDecl *D) {
5869   assert(!WritingAST && "Already writing the AST!");
5870   if (!D->isFromASTFile())
5871     return;
5872 
5873   // Since the actual instantiation is delayed, this really means that we need
5874   // to update the instantiation location.
5875   DeclUpdates[D].push_back(
5876       DeclUpdate(UPD_CXX_INSTANTIATED_STATIC_DATA_MEMBER,
5877        D->getMemberSpecializationInfo()->getPointOfInstantiation()));
5878 }
5879 
5880 void ASTWriter::AddedObjCCategoryToInterface(const ObjCCategoryDecl *CatD,
5881                                              const ObjCInterfaceDecl *IFD) {
5882   assert(!WritingAST && "Already writing the AST!");
5883   if (!IFD->isFromASTFile())
5884     return; // Declaration not imported from PCH.
5885 
5886   assert(IFD->getDefinition() && "Category on a class without a definition?");
5887   ObjCClassesWithCategories.insert(
5888     const_cast<ObjCInterfaceDecl *>(IFD->getDefinition()));
5889 }
5890 
5891 
5892 void ASTWriter::AddedObjCPropertyInClassExtension(const ObjCPropertyDecl *Prop,
5893                                           const ObjCPropertyDecl *OrigProp,
5894                                           const ObjCCategoryDecl *ClassExt) {
5895   const ObjCInterfaceDecl *D = ClassExt->getClassInterface();
5896   if (!D)
5897     return;
5898 
5899   assert(!WritingAST && "Already writing the AST!");
5900   if (!D->isFromASTFile())
5901     return; // Declaration not imported from PCH.
5902 
5903   RewriteDecl(D);
5904 }
5905 
5906 void ASTWriter::DeclarationMarkedUsed(const Decl *D) {
5907   assert(!WritingAST && "Already writing the AST!");
5908   if (!D->isFromASTFile())
5909     return;
5910 
5911   DeclUpdates[D].push_back(DeclUpdate(UPD_DECL_MARKED_USED));
5912 }
5913 
5914 void ASTWriter::DeclarationMarkedOpenMPThreadPrivate(const Decl *D) {
5915   assert(!WritingAST && "Already writing the AST!");
5916   if (!D->isFromASTFile())
5917     return;
5918 
5919   DeclUpdates[D].push_back(DeclUpdate(UPD_DECL_MARKED_OPENMP_THREADPRIVATE));
5920 }
5921