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     Record.push_back(WritingModule->IsSystem);
1220     Stream.EmitRecord(MODULE_MAP_FILE, Record);
1221   }
1222 
1223   // Imports
1224   if (Chain) {
1225     serialization::ModuleManager &Mgr = Chain->getModuleManager();
1226     Record.clear();
1227 
1228     for (ModuleManager::ModuleIterator M = Mgr.begin(), MEnd = Mgr.end();
1229          M != MEnd; ++M) {
1230       // Skip modules that weren't directly imported.
1231       if (!(*M)->isDirectlyImported())
1232         continue;
1233 
1234       Record.push_back((unsigned)(*M)->Kind); // FIXME: Stable encoding
1235       AddSourceLocation((*M)->ImportLoc, Record);
1236       Record.push_back((*M)->File->getSize());
1237       Record.push_back((*M)->File->getModificationTime());
1238       Record.push_back((*M)->Signature);
1239       AddPath((*M)->FileName, Record);
1240     }
1241     Stream.EmitRecord(IMPORTS, Record);
1242   }
1243 
1244   // Language options.
1245   Record.clear();
1246   const LangOptions &LangOpts = Context.getLangOpts();
1247 #define LANGOPT(Name, Bits, Default, Description) \
1248   Record.push_back(LangOpts.Name);
1249 #define ENUM_LANGOPT(Name, Type, Bits, Default, Description) \
1250   Record.push_back(static_cast<unsigned>(LangOpts.get##Name()));
1251 #include "clang/Basic/LangOptions.def"
1252 #define SANITIZER(NAME, ID)                                                    \
1253   Record.push_back(LangOpts.Sanitize.has(SanitizerKind::ID));
1254 #include "clang/Basic/Sanitizers.def"
1255 
1256   Record.push_back((unsigned) LangOpts.ObjCRuntime.getKind());
1257   AddVersionTuple(LangOpts.ObjCRuntime.getVersion(), Record);
1258 
1259   Record.push_back(LangOpts.CurrentModule.size());
1260   Record.append(LangOpts.CurrentModule.begin(), LangOpts.CurrentModule.end());
1261 
1262   // Comment options.
1263   Record.push_back(LangOpts.CommentOpts.BlockCommandNames.size());
1264   for (CommentOptions::BlockCommandNamesTy::const_iterator
1265            I = LangOpts.CommentOpts.BlockCommandNames.begin(),
1266            IEnd = LangOpts.CommentOpts.BlockCommandNames.end();
1267        I != IEnd; ++I) {
1268     AddString(*I, Record);
1269   }
1270   Record.push_back(LangOpts.CommentOpts.ParseAllComments);
1271 
1272   Stream.EmitRecord(LANGUAGE_OPTIONS, Record);
1273 
1274   // Target options.
1275   Record.clear();
1276   const TargetInfo &Target = Context.getTargetInfo();
1277   const TargetOptions &TargetOpts = Target.getTargetOpts();
1278   AddString(TargetOpts.Triple, Record);
1279   AddString(TargetOpts.CPU, Record);
1280   AddString(TargetOpts.ABI, Record);
1281   Record.push_back(TargetOpts.FeaturesAsWritten.size());
1282   for (unsigned I = 0, N = TargetOpts.FeaturesAsWritten.size(); I != N; ++I) {
1283     AddString(TargetOpts.FeaturesAsWritten[I], Record);
1284   }
1285   Record.push_back(TargetOpts.Features.size());
1286   for (unsigned I = 0, N = TargetOpts.Features.size(); I != N; ++I) {
1287     AddString(TargetOpts.Features[I], Record);
1288   }
1289   Stream.EmitRecord(TARGET_OPTIONS, Record);
1290 
1291   // Diagnostic options.
1292   Record.clear();
1293   const DiagnosticOptions &DiagOpts
1294     = Context.getDiagnostics().getDiagnosticOptions();
1295 #define DIAGOPT(Name, Bits, Default) Record.push_back(DiagOpts.Name);
1296 #define ENUM_DIAGOPT(Name, Type, Bits, Default) \
1297   Record.push_back(static_cast<unsigned>(DiagOpts.get##Name()));
1298 #include "clang/Basic/DiagnosticOptions.def"
1299   Record.push_back(DiagOpts.Warnings.size());
1300   for (unsigned I = 0, N = DiagOpts.Warnings.size(); I != N; ++I)
1301     AddString(DiagOpts.Warnings[I], Record);
1302   Record.push_back(DiagOpts.Remarks.size());
1303   for (unsigned I = 0, N = DiagOpts.Remarks.size(); I != N; ++I)
1304     AddString(DiagOpts.Remarks[I], Record);
1305   // Note: we don't serialize the log or serialization file names, because they
1306   // are generally transient files and will almost always be overridden.
1307   Stream.EmitRecord(DIAGNOSTIC_OPTIONS, Record);
1308 
1309   // File system options.
1310   Record.clear();
1311   const FileSystemOptions &FSOpts
1312     = Context.getSourceManager().getFileManager().getFileSystemOptions();
1313   AddString(FSOpts.WorkingDir, Record);
1314   Stream.EmitRecord(FILE_SYSTEM_OPTIONS, Record);
1315 
1316   // Header search options.
1317   Record.clear();
1318   const HeaderSearchOptions &HSOpts
1319     = PP.getHeaderSearchInfo().getHeaderSearchOpts();
1320   AddString(HSOpts.Sysroot, Record);
1321 
1322   // Include entries.
1323   Record.push_back(HSOpts.UserEntries.size());
1324   for (unsigned I = 0, N = HSOpts.UserEntries.size(); I != N; ++I) {
1325     const HeaderSearchOptions::Entry &Entry = HSOpts.UserEntries[I];
1326     AddString(Entry.Path, Record);
1327     Record.push_back(static_cast<unsigned>(Entry.Group));
1328     Record.push_back(Entry.IsFramework);
1329     Record.push_back(Entry.IgnoreSysRoot);
1330   }
1331 
1332   // System header prefixes.
1333   Record.push_back(HSOpts.SystemHeaderPrefixes.size());
1334   for (unsigned I = 0, N = HSOpts.SystemHeaderPrefixes.size(); I != N; ++I) {
1335     AddString(HSOpts.SystemHeaderPrefixes[I].Prefix, Record);
1336     Record.push_back(HSOpts.SystemHeaderPrefixes[I].IsSystemHeader);
1337   }
1338 
1339   AddString(HSOpts.ResourceDir, Record);
1340   AddString(HSOpts.ModuleCachePath, Record);
1341   AddString(HSOpts.ModuleUserBuildPath, Record);
1342   Record.push_back(HSOpts.DisableModuleHash);
1343   Record.push_back(HSOpts.UseBuiltinIncludes);
1344   Record.push_back(HSOpts.UseStandardSystemIncludes);
1345   Record.push_back(HSOpts.UseStandardCXXIncludes);
1346   Record.push_back(HSOpts.UseLibcxx);
1347   Stream.EmitRecord(HEADER_SEARCH_OPTIONS, Record);
1348 
1349   // Preprocessor options.
1350   Record.clear();
1351   const PreprocessorOptions &PPOpts = PP.getPreprocessorOpts();
1352 
1353   // Macro definitions.
1354   Record.push_back(PPOpts.Macros.size());
1355   for (unsigned I = 0, N = PPOpts.Macros.size(); I != N; ++I) {
1356     AddString(PPOpts.Macros[I].first, Record);
1357     Record.push_back(PPOpts.Macros[I].second);
1358   }
1359 
1360   // Includes
1361   Record.push_back(PPOpts.Includes.size());
1362   for (unsigned I = 0, N = PPOpts.Includes.size(); I != N; ++I)
1363     AddString(PPOpts.Includes[I], Record);
1364 
1365   // Macro includes
1366   Record.push_back(PPOpts.MacroIncludes.size());
1367   for (unsigned I = 0, N = PPOpts.MacroIncludes.size(); I != N; ++I)
1368     AddString(PPOpts.MacroIncludes[I], Record);
1369 
1370   Record.push_back(PPOpts.UsePredefines);
1371   // Detailed record is important since it is used for the module cache hash.
1372   Record.push_back(PPOpts.DetailedRecord);
1373   AddString(PPOpts.ImplicitPCHInclude, Record);
1374   AddString(PPOpts.ImplicitPTHInclude, Record);
1375   Record.push_back(static_cast<unsigned>(PPOpts.ObjCXXARCStandardLibrary));
1376   Stream.EmitRecord(PREPROCESSOR_OPTIONS, Record);
1377 
1378   // Original file name and file ID
1379   SourceManager &SM = Context.getSourceManager();
1380   if (const FileEntry *MainFile = SM.getFileEntryForID(SM.getMainFileID())) {
1381     BitCodeAbbrev *FileAbbrev = new BitCodeAbbrev();
1382     FileAbbrev->Add(BitCodeAbbrevOp(ORIGINAL_FILE));
1383     FileAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // File ID
1384     FileAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // File name
1385     unsigned FileAbbrevCode = Stream.EmitAbbrev(FileAbbrev);
1386 
1387     Record.clear();
1388     Record.push_back(ORIGINAL_FILE);
1389     Record.push_back(SM.getMainFileID().getOpaqueValue());
1390     EmitRecordWithPath(FileAbbrevCode, Record, MainFile->getName());
1391   }
1392 
1393   Record.clear();
1394   Record.push_back(SM.getMainFileID().getOpaqueValue());
1395   Stream.EmitRecord(ORIGINAL_FILE_ID, Record);
1396 
1397   // Original PCH directory
1398   if (!OutputFile.empty() && OutputFile != "-") {
1399     BitCodeAbbrev *Abbrev = new BitCodeAbbrev();
1400     Abbrev->Add(BitCodeAbbrevOp(ORIGINAL_PCH_DIR));
1401     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // File name
1402     unsigned AbbrevCode = Stream.EmitAbbrev(Abbrev);
1403 
1404     SmallString<128> OutputPath(OutputFile);
1405 
1406     llvm::sys::fs::make_absolute(OutputPath);
1407     StringRef origDir = llvm::sys::path::parent_path(OutputPath);
1408 
1409     RecordData Record;
1410     Record.push_back(ORIGINAL_PCH_DIR);
1411     Stream.EmitRecordWithBlob(AbbrevCode, Record, origDir);
1412   }
1413 
1414   WriteInputFiles(Context.SourceMgr,
1415                   PP.getHeaderSearchInfo().getHeaderSearchOpts(),
1416                   PP.getLangOpts().Modules);
1417   Stream.ExitBlock();
1418 }
1419 
1420 namespace  {
1421   /// \brief An input file.
1422   struct InputFileEntry {
1423     const FileEntry *File;
1424     bool IsSystemFile;
1425     bool BufferOverridden;
1426   };
1427 }
1428 
1429 void ASTWriter::WriteInputFiles(SourceManager &SourceMgr,
1430                                 HeaderSearchOptions &HSOpts,
1431                                 bool Modules) {
1432   using namespace llvm;
1433   Stream.EnterSubblock(INPUT_FILES_BLOCK_ID, 4);
1434   RecordData Record;
1435 
1436   // Create input-file abbreviation.
1437   BitCodeAbbrev *IFAbbrev = new BitCodeAbbrev();
1438   IFAbbrev->Add(BitCodeAbbrevOp(INPUT_FILE));
1439   IFAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // ID
1440   IFAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 12)); // Size
1441   IFAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 32)); // Modification time
1442   IFAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Overridden
1443   IFAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // File name
1444   unsigned IFAbbrevCode = Stream.EmitAbbrev(IFAbbrev);
1445 
1446   // Get all ContentCache objects for files, sorted by whether the file is a
1447   // system one or not. System files go at the back, users files at the front.
1448   std::deque<InputFileEntry> SortedFiles;
1449   for (unsigned I = 1, N = SourceMgr.local_sloc_entry_size(); I != N; ++I) {
1450     // Get this source location entry.
1451     const SrcMgr::SLocEntry *SLoc = &SourceMgr.getLocalSLocEntry(I);
1452     assert(&SourceMgr.getSLocEntry(FileID::get(I)) == SLoc);
1453 
1454     // We only care about file entries that were not overridden.
1455     if (!SLoc->isFile())
1456       continue;
1457     const SrcMgr::ContentCache *Cache = SLoc->getFile().getContentCache();
1458     if (!Cache->OrigEntry)
1459       continue;
1460 
1461     InputFileEntry Entry;
1462     Entry.File = Cache->OrigEntry;
1463     Entry.IsSystemFile = Cache->IsSystemFile;
1464     Entry.BufferOverridden = Cache->BufferOverridden;
1465     if (Cache->IsSystemFile)
1466       SortedFiles.push_back(Entry);
1467     else
1468       SortedFiles.push_front(Entry);
1469   }
1470 
1471   unsigned UserFilesNum = 0;
1472   // Write out all of the input files.
1473   std::vector<uint64_t> InputFileOffsets;
1474   for (std::deque<InputFileEntry>::iterator
1475          I = SortedFiles.begin(), E = SortedFiles.end(); I != E; ++I) {
1476     const InputFileEntry &Entry = *I;
1477 
1478     uint32_t &InputFileID = InputFileIDs[Entry.File];
1479     if (InputFileID != 0)
1480       continue; // already recorded this file.
1481 
1482     // Record this entry's offset.
1483     InputFileOffsets.push_back(Stream.GetCurrentBitNo());
1484 
1485     InputFileID = InputFileOffsets.size();
1486 
1487     if (!Entry.IsSystemFile)
1488       ++UserFilesNum;
1489 
1490     Record.clear();
1491     Record.push_back(INPUT_FILE);
1492     Record.push_back(InputFileOffsets.size());
1493 
1494     // Emit size/modification time for this file.
1495     Record.push_back(Entry.File->getSize());
1496     Record.push_back(Entry.File->getModificationTime());
1497 
1498     // Whether this file was overridden.
1499     Record.push_back(Entry.BufferOverridden);
1500 
1501     EmitRecordWithPath(IFAbbrevCode, Record, Entry.File->getName());
1502   }
1503 
1504   Stream.ExitBlock();
1505 
1506   // Create input file offsets abbreviation.
1507   BitCodeAbbrev *OffsetsAbbrev = new BitCodeAbbrev();
1508   OffsetsAbbrev->Add(BitCodeAbbrevOp(INPUT_FILE_OFFSETS));
1509   OffsetsAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // # input files
1510   OffsetsAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // # non-system
1511                                                                 //   input files
1512   OffsetsAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));   // Array
1513   unsigned OffsetsAbbrevCode = Stream.EmitAbbrev(OffsetsAbbrev);
1514 
1515   // Write input file offsets.
1516   Record.clear();
1517   Record.push_back(INPUT_FILE_OFFSETS);
1518   Record.push_back(InputFileOffsets.size());
1519   Record.push_back(UserFilesNum);
1520   Stream.EmitRecordWithBlob(OffsetsAbbrevCode, Record, data(InputFileOffsets));
1521 }
1522 
1523 //===----------------------------------------------------------------------===//
1524 // Source Manager Serialization
1525 //===----------------------------------------------------------------------===//
1526 
1527 /// \brief Create an abbreviation for the SLocEntry that refers to a
1528 /// file.
1529 static unsigned CreateSLocFileAbbrev(llvm::BitstreamWriter &Stream) {
1530   using namespace llvm;
1531   BitCodeAbbrev *Abbrev = new BitCodeAbbrev();
1532   Abbrev->Add(BitCodeAbbrevOp(SM_SLOC_FILE_ENTRY));
1533   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // Offset
1534   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // Include location
1535   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2)); // Characteristic
1536   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Line directives
1537   // FileEntry fields.
1538   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Input File ID
1539   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // NumCreatedFIDs
1540   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 24)); // FirstDeclIndex
1541   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // NumDecls
1542   return Stream.EmitAbbrev(Abbrev);
1543 }
1544 
1545 /// \brief Create an abbreviation for the SLocEntry that refers to a
1546 /// buffer.
1547 static unsigned CreateSLocBufferAbbrev(llvm::BitstreamWriter &Stream) {
1548   using namespace llvm;
1549   BitCodeAbbrev *Abbrev = new BitCodeAbbrev();
1550   Abbrev->Add(BitCodeAbbrevOp(SM_SLOC_BUFFER_ENTRY));
1551   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // Offset
1552   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // Include location
1553   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2)); // Characteristic
1554   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Line directives
1555   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Buffer name blob
1556   return Stream.EmitAbbrev(Abbrev);
1557 }
1558 
1559 /// \brief Create an abbreviation for the SLocEntry that refers to a
1560 /// buffer's blob.
1561 static unsigned CreateSLocBufferBlobAbbrev(llvm::BitstreamWriter &Stream) {
1562   using namespace llvm;
1563   BitCodeAbbrev *Abbrev = new BitCodeAbbrev();
1564   Abbrev->Add(BitCodeAbbrevOp(SM_SLOC_BUFFER_BLOB));
1565   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Blob
1566   return Stream.EmitAbbrev(Abbrev);
1567 }
1568 
1569 /// \brief Create an abbreviation for the SLocEntry that refers to a macro
1570 /// expansion.
1571 static unsigned CreateSLocExpansionAbbrev(llvm::BitstreamWriter &Stream) {
1572   using namespace llvm;
1573   BitCodeAbbrev *Abbrev = new BitCodeAbbrev();
1574   Abbrev->Add(BitCodeAbbrevOp(SM_SLOC_EXPANSION_ENTRY));
1575   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // Offset
1576   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // Spelling location
1577   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // Start location
1578   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // End location
1579   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Token length
1580   return Stream.EmitAbbrev(Abbrev);
1581 }
1582 
1583 namespace {
1584   // Trait used for the on-disk hash table of header search information.
1585   class HeaderFileInfoTrait {
1586     ASTWriter &Writer;
1587     const HeaderSearch &HS;
1588 
1589     // Keep track of the framework names we've used during serialization.
1590     SmallVector<char, 128> FrameworkStringData;
1591     llvm::StringMap<unsigned> FrameworkNameOffset;
1592 
1593   public:
1594     HeaderFileInfoTrait(ASTWriter &Writer, const HeaderSearch &HS)
1595       : Writer(Writer), HS(HS) { }
1596 
1597     struct key_type {
1598       const FileEntry *FE;
1599       const char *Filename;
1600     };
1601     typedef const key_type &key_type_ref;
1602 
1603     typedef HeaderFileInfo data_type;
1604     typedef const data_type &data_type_ref;
1605     typedef unsigned hash_value_type;
1606     typedef unsigned offset_type;
1607 
1608     static hash_value_type ComputeHash(key_type_ref key) {
1609       // The hash is based only on size/time of the file, so that the reader can
1610       // match even when symlinking or excess path elements ("foo/../", "../")
1611       // change the form of the name. However, complete path is still the key.
1612       //
1613       // FIXME: Using the mtime here will cause problems for explicit module
1614       // imports.
1615       return llvm::hash_combine(key.FE->getSize(),
1616                                 key.FE->getModificationTime());
1617     }
1618 
1619     std::pair<unsigned,unsigned>
1620     EmitKeyDataLength(raw_ostream& Out, key_type_ref key, data_type_ref Data) {
1621       using namespace llvm::support;
1622       endian::Writer<little> Writer(Out);
1623       unsigned KeyLen = strlen(key.Filename) + 1 + 8 + 8;
1624       Writer.write<uint16_t>(KeyLen);
1625       unsigned DataLen = 1 + 2 + 4 + 4;
1626       if (Data.isModuleHeader)
1627         DataLen += 4;
1628       Writer.write<uint8_t>(DataLen);
1629       return std::make_pair(KeyLen, DataLen);
1630     }
1631 
1632     void EmitKey(raw_ostream& Out, key_type_ref key, unsigned KeyLen) {
1633       using namespace llvm::support;
1634       endian::Writer<little> LE(Out);
1635       LE.write<uint64_t>(key.FE->getSize());
1636       KeyLen -= 8;
1637       LE.write<uint64_t>(key.FE->getModificationTime());
1638       KeyLen -= 8;
1639       Out.write(key.Filename, KeyLen);
1640     }
1641 
1642     void EmitData(raw_ostream &Out, key_type_ref key,
1643                   data_type_ref Data, unsigned DataLen) {
1644       using namespace llvm::support;
1645       endian::Writer<little> LE(Out);
1646       uint64_t Start = Out.tell(); (void)Start;
1647 
1648       unsigned char Flags = (Data.HeaderRole << 6)
1649                           | (Data.isImport << 5)
1650                           | (Data.isPragmaOnce << 4)
1651                           | (Data.DirInfo << 2)
1652                           | (Data.Resolved << 1)
1653                           | Data.IndexHeaderMapHeader;
1654       LE.write<uint8_t>(Flags);
1655       LE.write<uint16_t>(Data.NumIncludes);
1656 
1657       if (!Data.ControllingMacro)
1658         LE.write<uint32_t>(Data.ControllingMacroID);
1659       else
1660         LE.write<uint32_t>(Writer.getIdentifierRef(Data.ControllingMacro));
1661 
1662       unsigned Offset = 0;
1663       if (!Data.Framework.empty()) {
1664         // If this header refers into a framework, save the framework name.
1665         llvm::StringMap<unsigned>::iterator Pos
1666           = FrameworkNameOffset.find(Data.Framework);
1667         if (Pos == FrameworkNameOffset.end()) {
1668           Offset = FrameworkStringData.size() + 1;
1669           FrameworkStringData.append(Data.Framework.begin(),
1670                                      Data.Framework.end());
1671           FrameworkStringData.push_back(0);
1672 
1673           FrameworkNameOffset[Data.Framework] = Offset;
1674         } else
1675           Offset = Pos->second;
1676       }
1677       LE.write<uint32_t>(Offset);
1678 
1679       if (Data.isModuleHeader) {
1680         Module *Mod = HS.findModuleForHeader(key.FE).getModule();
1681         LE.write<uint32_t>(Writer.getExistingSubmoduleID(Mod));
1682       }
1683 
1684       assert(Out.tell() - Start == DataLen && "Wrong data length");
1685     }
1686 
1687     const char *strings_begin() const { return FrameworkStringData.begin(); }
1688     const char *strings_end() const { return FrameworkStringData.end(); }
1689   };
1690 } // end anonymous namespace
1691 
1692 /// \brief Write the header search block for the list of files that
1693 ///
1694 /// \param HS The header search structure to save.
1695 void ASTWriter::WriteHeaderSearch(const HeaderSearch &HS) {
1696   SmallVector<const FileEntry *, 16> FilesByUID;
1697   HS.getFileMgr().GetUniqueIDMapping(FilesByUID);
1698 
1699   if (FilesByUID.size() > HS.header_file_size())
1700     FilesByUID.resize(HS.header_file_size());
1701 
1702   HeaderFileInfoTrait GeneratorTrait(*this, HS);
1703   llvm::OnDiskChainedHashTableGenerator<HeaderFileInfoTrait> Generator;
1704   SmallVector<const char *, 4> SavedStrings;
1705   unsigned NumHeaderSearchEntries = 0;
1706   for (unsigned UID = 0, LastUID = FilesByUID.size(); UID != LastUID; ++UID) {
1707     const FileEntry *File = FilesByUID[UID];
1708     if (!File)
1709       continue;
1710 
1711     // Use HeaderSearch's getFileInfo to make sure we get the HeaderFileInfo
1712     // from the external source if it was not provided already.
1713     HeaderFileInfo HFI;
1714     if (!HS.tryGetFileInfo(File, HFI) ||
1715         (HFI.External && Chain) ||
1716         (HFI.isModuleHeader && !HFI.isCompilingModuleHeader))
1717       continue;
1718 
1719     // Massage the file path into an appropriate form.
1720     const char *Filename = File->getName();
1721     SmallString<128> FilenameTmp(Filename);
1722     if (PreparePathForOutput(FilenameTmp)) {
1723       // If we performed any translation on the file name at all, we need to
1724       // save this string, since the generator will refer to it later.
1725       Filename = strdup(FilenameTmp.c_str());
1726       SavedStrings.push_back(Filename);
1727     }
1728 
1729     HeaderFileInfoTrait::key_type key = { File, Filename };
1730     Generator.insert(key, HFI, GeneratorTrait);
1731     ++NumHeaderSearchEntries;
1732   }
1733 
1734   // Create the on-disk hash table in a buffer.
1735   SmallString<4096> TableData;
1736   uint32_t BucketOffset;
1737   {
1738     using namespace llvm::support;
1739     llvm::raw_svector_ostream Out(TableData);
1740     // Make sure that no bucket is at offset 0
1741     endian::Writer<little>(Out).write<uint32_t>(0);
1742     BucketOffset = Generator.Emit(Out, GeneratorTrait);
1743   }
1744 
1745   // Create a blob abbreviation
1746   using namespace llvm;
1747   BitCodeAbbrev *Abbrev = new BitCodeAbbrev();
1748   Abbrev->Add(BitCodeAbbrevOp(HEADER_SEARCH_TABLE));
1749   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
1750   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
1751   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
1752   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
1753   unsigned TableAbbrev = Stream.EmitAbbrev(Abbrev);
1754 
1755   // Write the header search table
1756   RecordData Record;
1757   Record.push_back(HEADER_SEARCH_TABLE);
1758   Record.push_back(BucketOffset);
1759   Record.push_back(NumHeaderSearchEntries);
1760   Record.push_back(TableData.size());
1761   TableData.append(GeneratorTrait.strings_begin(),GeneratorTrait.strings_end());
1762   Stream.EmitRecordWithBlob(TableAbbrev, Record, TableData.str());
1763 
1764   // Free all of the strings we had to duplicate.
1765   for (unsigned I = 0, N = SavedStrings.size(); I != N; ++I)
1766     free(const_cast<char *>(SavedStrings[I]));
1767 }
1768 
1769 /// \brief Writes the block containing the serialized form of the
1770 /// source manager.
1771 ///
1772 /// TODO: We should probably use an on-disk hash table (stored in a
1773 /// blob), indexed based on the file name, so that we only create
1774 /// entries for files that we actually need. In the common case (no
1775 /// errors), we probably won't have to create file entries for any of
1776 /// the files in the AST.
1777 void ASTWriter::WriteSourceManagerBlock(SourceManager &SourceMgr,
1778                                         const Preprocessor &PP) {
1779   RecordData Record;
1780 
1781   // Enter the source manager block.
1782   Stream.EnterSubblock(SOURCE_MANAGER_BLOCK_ID, 3);
1783 
1784   // Abbreviations for the various kinds of source-location entries.
1785   unsigned SLocFileAbbrv = CreateSLocFileAbbrev(Stream);
1786   unsigned SLocBufferAbbrv = CreateSLocBufferAbbrev(Stream);
1787   unsigned SLocBufferBlobAbbrv = CreateSLocBufferBlobAbbrev(Stream);
1788   unsigned SLocExpansionAbbrv = CreateSLocExpansionAbbrev(Stream);
1789 
1790   // Write out the source location entry table. We skip the first
1791   // entry, which is always the same dummy entry.
1792   std::vector<uint32_t> SLocEntryOffsets;
1793   RecordData PreloadSLocs;
1794   SLocEntryOffsets.reserve(SourceMgr.local_sloc_entry_size() - 1);
1795   for (unsigned I = 1, N = SourceMgr.local_sloc_entry_size();
1796        I != N; ++I) {
1797     // Get this source location entry.
1798     const SrcMgr::SLocEntry *SLoc = &SourceMgr.getLocalSLocEntry(I);
1799     FileID FID = FileID::get(I);
1800     assert(&SourceMgr.getSLocEntry(FID) == SLoc);
1801 
1802     // Record the offset of this source-location entry.
1803     SLocEntryOffsets.push_back(Stream.GetCurrentBitNo());
1804 
1805     // Figure out which record code to use.
1806     unsigned Code;
1807     if (SLoc->isFile()) {
1808       const SrcMgr::ContentCache *Cache = SLoc->getFile().getContentCache();
1809       if (Cache->OrigEntry) {
1810         Code = SM_SLOC_FILE_ENTRY;
1811       } else
1812         Code = SM_SLOC_BUFFER_ENTRY;
1813     } else
1814       Code = SM_SLOC_EXPANSION_ENTRY;
1815     Record.clear();
1816     Record.push_back(Code);
1817 
1818     // Starting offset of this entry within this module, so skip the dummy.
1819     Record.push_back(SLoc->getOffset() - 2);
1820     if (SLoc->isFile()) {
1821       const SrcMgr::FileInfo &File = SLoc->getFile();
1822       Record.push_back(File.getIncludeLoc().getRawEncoding());
1823       Record.push_back(File.getFileCharacteristic()); // FIXME: stable encoding
1824       Record.push_back(File.hasLineDirectives());
1825 
1826       const SrcMgr::ContentCache *Content = File.getContentCache();
1827       if (Content->OrigEntry) {
1828         assert(Content->OrigEntry == Content->ContentsEntry &&
1829                "Writing to AST an overridden file is not supported");
1830 
1831         // The source location entry is a file. Emit input file ID.
1832         assert(InputFileIDs[Content->OrigEntry] != 0 && "Missed file entry");
1833         Record.push_back(InputFileIDs[Content->OrigEntry]);
1834 
1835         Record.push_back(File.NumCreatedFIDs);
1836 
1837         FileDeclIDsTy::iterator FDI = FileDeclIDs.find(FID);
1838         if (FDI != FileDeclIDs.end()) {
1839           Record.push_back(FDI->second->FirstDeclIndex);
1840           Record.push_back(FDI->second->DeclIDs.size());
1841         } else {
1842           Record.push_back(0);
1843           Record.push_back(0);
1844         }
1845 
1846         Stream.EmitRecordWithAbbrev(SLocFileAbbrv, Record);
1847 
1848         if (Content->BufferOverridden) {
1849           Record.clear();
1850           Record.push_back(SM_SLOC_BUFFER_BLOB);
1851           const llvm::MemoryBuffer *Buffer
1852             = Content->getBuffer(PP.getDiagnostics(), PP.getSourceManager());
1853           Stream.EmitRecordWithBlob(SLocBufferBlobAbbrv, Record,
1854                                     StringRef(Buffer->getBufferStart(),
1855                                               Buffer->getBufferSize() + 1));
1856         }
1857       } else {
1858         // The source location entry is a buffer. The blob associated
1859         // with this entry contains the contents of the buffer.
1860 
1861         // We add one to the size so that we capture the trailing NULL
1862         // that is required by llvm::MemoryBuffer::getMemBuffer (on
1863         // the reader side).
1864         const llvm::MemoryBuffer *Buffer
1865           = Content->getBuffer(PP.getDiagnostics(), PP.getSourceManager());
1866         const char *Name = Buffer->getBufferIdentifier();
1867         Stream.EmitRecordWithBlob(SLocBufferAbbrv, Record,
1868                                   StringRef(Name, strlen(Name) + 1));
1869         Record.clear();
1870         Record.push_back(SM_SLOC_BUFFER_BLOB);
1871         Stream.EmitRecordWithBlob(SLocBufferBlobAbbrv, Record,
1872                                   StringRef(Buffer->getBufferStart(),
1873                                                   Buffer->getBufferSize() + 1));
1874 
1875         if (strcmp(Name, "<built-in>") == 0) {
1876           PreloadSLocs.push_back(SLocEntryOffsets.size());
1877         }
1878       }
1879     } else {
1880       // The source location entry is a macro expansion.
1881       const SrcMgr::ExpansionInfo &Expansion = SLoc->getExpansion();
1882       Record.push_back(Expansion.getSpellingLoc().getRawEncoding());
1883       Record.push_back(Expansion.getExpansionLocStart().getRawEncoding());
1884       Record.push_back(Expansion.isMacroArgExpansion() ? 0
1885                              : Expansion.getExpansionLocEnd().getRawEncoding());
1886 
1887       // Compute the token length for this macro expansion.
1888       unsigned NextOffset = SourceMgr.getNextLocalOffset();
1889       if (I + 1 != N)
1890         NextOffset = SourceMgr.getLocalSLocEntry(I + 1).getOffset();
1891       Record.push_back(NextOffset - SLoc->getOffset() - 1);
1892       Stream.EmitRecordWithAbbrev(SLocExpansionAbbrv, Record);
1893     }
1894   }
1895 
1896   Stream.ExitBlock();
1897 
1898   if (SLocEntryOffsets.empty())
1899     return;
1900 
1901   // Write the source-location offsets table into the AST block. This
1902   // table is used for lazily loading source-location information.
1903   using namespace llvm;
1904   BitCodeAbbrev *Abbrev = new BitCodeAbbrev();
1905   Abbrev->Add(BitCodeAbbrevOp(SOURCE_LOCATION_OFFSETS));
1906   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 16)); // # of slocs
1907   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 16)); // total size
1908   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // offsets
1909   unsigned SLocOffsetsAbbrev = Stream.EmitAbbrev(Abbrev);
1910 
1911   Record.clear();
1912   Record.push_back(SOURCE_LOCATION_OFFSETS);
1913   Record.push_back(SLocEntryOffsets.size());
1914   Record.push_back(SourceMgr.getNextLocalOffset() - 1); // skip dummy
1915   Stream.EmitRecordWithBlob(SLocOffsetsAbbrev, Record, data(SLocEntryOffsets));
1916 
1917   // Write the source location entry preloads array, telling the AST
1918   // reader which source locations entries it should load eagerly.
1919   Stream.EmitRecord(SOURCE_LOCATION_PRELOADS, PreloadSLocs);
1920 
1921   // Write the line table. It depends on remapping working, so it must come
1922   // after the source location offsets.
1923   if (SourceMgr.hasLineTable()) {
1924     LineTableInfo &LineTable = SourceMgr.getLineTable();
1925 
1926     Record.clear();
1927     // Emit the file names.
1928     Record.push_back(LineTable.getNumFilenames());
1929     for (unsigned I = 0, N = LineTable.getNumFilenames(); I != N; ++I)
1930       AddPath(LineTable.getFilename(I), Record);
1931 
1932     // Emit the line entries
1933     for (LineTableInfo::iterator L = LineTable.begin(), LEnd = LineTable.end();
1934          L != LEnd; ++L) {
1935       // Only emit entries for local files.
1936       if (L->first.ID < 0)
1937         continue;
1938 
1939       // Emit the file ID
1940       Record.push_back(L->first.ID);
1941 
1942       // Emit the line entries
1943       Record.push_back(L->second.size());
1944       for (std::vector<LineEntry>::iterator LE = L->second.begin(),
1945                                          LEEnd = L->second.end();
1946            LE != LEEnd; ++LE) {
1947         Record.push_back(LE->FileOffset);
1948         Record.push_back(LE->LineNo);
1949         Record.push_back(LE->FilenameID);
1950         Record.push_back((unsigned)LE->FileKind);
1951         Record.push_back(LE->IncludeOffset);
1952       }
1953     }
1954     Stream.EmitRecord(SOURCE_MANAGER_LINE_TABLE, Record);
1955   }
1956 }
1957 
1958 //===----------------------------------------------------------------------===//
1959 // Preprocessor Serialization
1960 //===----------------------------------------------------------------------===//
1961 
1962 namespace {
1963 class ASTMacroTableTrait {
1964 public:
1965   typedef IdentID key_type;
1966   typedef key_type key_type_ref;
1967 
1968   struct Data {
1969     uint32_t MacroDirectivesOffset;
1970   };
1971 
1972   typedef Data data_type;
1973   typedef const data_type &data_type_ref;
1974   typedef unsigned hash_value_type;
1975   typedef unsigned offset_type;
1976 
1977   static hash_value_type ComputeHash(IdentID IdID) {
1978     return llvm::hash_value(IdID);
1979   }
1980 
1981   std::pair<unsigned,unsigned>
1982   static EmitKeyDataLength(raw_ostream& Out,
1983                            key_type_ref Key, data_type_ref Data) {
1984     unsigned KeyLen = 4; // IdentID.
1985     unsigned DataLen = 4; // MacroDirectivesOffset.
1986     return std::make_pair(KeyLen, DataLen);
1987   }
1988 
1989   static void EmitKey(raw_ostream& Out, key_type_ref Key, unsigned KeyLen) {
1990     using namespace llvm::support;
1991     endian::Writer<little>(Out).write<uint32_t>(Key);
1992   }
1993 
1994   static void EmitData(raw_ostream& Out, key_type_ref Key, data_type_ref Data,
1995                        unsigned) {
1996     using namespace llvm::support;
1997     endian::Writer<little>(Out).write<uint32_t>(Data.MacroDirectivesOffset);
1998   }
1999 };
2000 } // end anonymous namespace
2001 
2002 static int compareMacroDirectives(
2003     const std::pair<const IdentifierInfo *, MacroDirective *> *X,
2004     const std::pair<const IdentifierInfo *, MacroDirective *> *Y) {
2005   return X->first->getName().compare(Y->first->getName());
2006 }
2007 
2008 static bool shouldIgnoreMacro(MacroDirective *MD, bool IsModule,
2009                               const Preprocessor &PP) {
2010   if (MacroInfo *MI = MD->getMacroInfo())
2011     if (MI->isBuiltinMacro())
2012       return true;
2013 
2014   if (IsModule) {
2015     // Re-export any imported directives.
2016     if (MD->isImported())
2017       return false;
2018 
2019     SourceLocation Loc = MD->getLocation();
2020     if (Loc.isInvalid())
2021       return true;
2022     if (PP.getSourceManager().getFileID(Loc) == PP.getPredefinesFileID())
2023       return true;
2024   }
2025 
2026   return false;
2027 }
2028 
2029 /// \brief Writes the block containing the serialized form of the
2030 /// preprocessor.
2031 ///
2032 void ASTWriter::WritePreprocessor(const Preprocessor &PP, bool IsModule) {
2033   PreprocessingRecord *PPRec = PP.getPreprocessingRecord();
2034   if (PPRec)
2035     WritePreprocessorDetail(*PPRec);
2036 
2037   RecordData Record;
2038 
2039   // If the preprocessor __COUNTER__ value has been bumped, remember it.
2040   if (PP.getCounterValue() != 0) {
2041     Record.push_back(PP.getCounterValue());
2042     Stream.EmitRecord(PP_COUNTER_VALUE, Record);
2043     Record.clear();
2044   }
2045 
2046   // Enter the preprocessor block.
2047   Stream.EnterSubblock(PREPROCESSOR_BLOCK_ID, 3);
2048 
2049   // If the AST file contains __DATE__ or __TIME__ emit a warning about this.
2050   // FIXME: use diagnostics subsystem for localization etc.
2051   if (PP.SawDateOrTime())
2052     fprintf(stderr, "warning: precompiled header used __DATE__ or __TIME__.\n");
2053 
2054 
2055   // Loop over all the macro directives that are live at the end of the file,
2056   // emitting each to the PP section.
2057 
2058   // Construct the list of macro directives that need to be serialized.
2059   SmallVector<std::pair<const IdentifierInfo *, MacroDirective *>, 2>
2060     MacroDirectives;
2061   for (Preprocessor::macro_iterator
2062          I = PP.macro_begin(/*IncludeExternalMacros=*/false),
2063          E = PP.macro_end(/*IncludeExternalMacros=*/false);
2064        I != E; ++I) {
2065     MacroDirectives.push_back(std::make_pair(I->first, I->second));
2066   }
2067 
2068   // Sort the set of macro definitions that need to be serialized by the
2069   // name of the macro, to provide a stable ordering.
2070   llvm::array_pod_sort(MacroDirectives.begin(), MacroDirectives.end(),
2071                        &compareMacroDirectives);
2072 
2073   llvm::OnDiskChainedHashTableGenerator<ASTMacroTableTrait> Generator;
2074 
2075   // Emit the macro directives as a list and associate the offset with the
2076   // identifier they belong to.
2077   for (unsigned I = 0, N = MacroDirectives.size(); I != N; ++I) {
2078     const IdentifierInfo *Name = MacroDirectives[I].first;
2079     uint64_t MacroDirectiveOffset = Stream.GetCurrentBitNo();
2080     MacroDirective *MD = MacroDirectives[I].second;
2081 
2082     // If the macro or identifier need no updates, don't write the macro history
2083     // for this one.
2084     // FIXME: Chain the macro history instead of re-writing it.
2085     if (MD->isFromPCH() &&
2086         Name->isFromAST() && !Name->hasChangedSinceDeserialization())
2087       continue;
2088 
2089     // Emit the macro directives in reverse source order.
2090     for (; MD; MD = MD->getPrevious()) {
2091       if (shouldIgnoreMacro(MD, IsModule, PP))
2092         continue;
2093 
2094       AddSourceLocation(MD->getLocation(), Record);
2095       Record.push_back(MD->getKind());
2096       if (auto *DefMD = dyn_cast<DefMacroDirective>(MD)) {
2097         MacroID InfoID = getMacroRef(DefMD->getInfo(), Name);
2098         Record.push_back(InfoID);
2099         Record.push_back(DefMD->getOwningModuleID());
2100         Record.push_back(DefMD->isAmbiguous());
2101       } else if (auto *UndefMD = dyn_cast<UndefMacroDirective>(MD)) {
2102         Record.push_back(UndefMD->getOwningModuleID());
2103       } else {
2104         auto *VisMD = cast<VisibilityMacroDirective>(MD);
2105         Record.push_back(VisMD->isPublic());
2106       }
2107 
2108       if (MD->isImported()) {
2109         auto Overrides = MD->getOverriddenModules();
2110         Record.push_back(Overrides.size());
2111         Record.append(Overrides.begin(), Overrides.end());
2112       }
2113     }
2114     if (Record.empty())
2115       continue;
2116 
2117     Stream.EmitRecord(PP_MACRO_DIRECTIVE_HISTORY, Record);
2118     Record.clear();
2119 
2120     IdentMacroDirectivesOffsetMap[Name] = MacroDirectiveOffset;
2121 
2122     IdentID NameID = getIdentifierRef(Name);
2123     ASTMacroTableTrait::Data data;
2124     data.MacroDirectivesOffset = MacroDirectiveOffset;
2125     Generator.insert(NameID, data);
2126   }
2127 
2128   /// \brief Offsets of each of the macros into the bitstream, indexed by
2129   /// the local macro ID
2130   ///
2131   /// For each identifier that is associated with a macro, this map
2132   /// provides the offset into the bitstream where that macro is
2133   /// defined.
2134   std::vector<uint32_t> MacroOffsets;
2135 
2136   for (unsigned I = 0, N = MacroInfosToEmit.size(); I != N; ++I) {
2137     const IdentifierInfo *Name = MacroInfosToEmit[I].Name;
2138     MacroInfo *MI = MacroInfosToEmit[I].MI;
2139     MacroID ID = MacroInfosToEmit[I].ID;
2140 
2141     if (ID < FirstMacroID) {
2142       assert(0 && "Loaded MacroInfo entered MacroInfosToEmit ?");
2143       continue;
2144     }
2145 
2146     // Record the local offset of this macro.
2147     unsigned Index = ID - FirstMacroID;
2148     if (Index == MacroOffsets.size())
2149       MacroOffsets.push_back(Stream.GetCurrentBitNo());
2150     else {
2151       if (Index > MacroOffsets.size())
2152         MacroOffsets.resize(Index + 1);
2153 
2154       MacroOffsets[Index] = Stream.GetCurrentBitNo();
2155     }
2156 
2157     AddIdentifierRef(Name, Record);
2158     Record.push_back(inferSubmoduleIDFromLocation(MI->getDefinitionLoc()));
2159     AddSourceLocation(MI->getDefinitionLoc(), Record);
2160     AddSourceLocation(MI->getDefinitionEndLoc(), Record);
2161     Record.push_back(MI->isUsed());
2162     Record.push_back(MI->isUsedForHeaderGuard());
2163     unsigned Code;
2164     if (MI->isObjectLike()) {
2165       Code = PP_MACRO_OBJECT_LIKE;
2166     } else {
2167       Code = PP_MACRO_FUNCTION_LIKE;
2168 
2169       Record.push_back(MI->isC99Varargs());
2170       Record.push_back(MI->isGNUVarargs());
2171       Record.push_back(MI->hasCommaPasting());
2172       Record.push_back(MI->getNumArgs());
2173       for (MacroInfo::arg_iterator I = MI->arg_begin(), E = MI->arg_end();
2174            I != E; ++I)
2175         AddIdentifierRef(*I, Record);
2176     }
2177 
2178     // If we have a detailed preprocessing record, record the macro definition
2179     // ID that corresponds to this macro.
2180     if (PPRec)
2181       Record.push_back(MacroDefinitions[PPRec->findMacroDefinition(MI)]);
2182 
2183     Stream.EmitRecord(Code, Record);
2184     Record.clear();
2185 
2186     // Emit the tokens array.
2187     for (unsigned TokNo = 0, e = MI->getNumTokens(); TokNo != e; ++TokNo) {
2188       // Note that we know that the preprocessor does not have any annotation
2189       // tokens in it because they are created by the parser, and thus can't
2190       // be in a macro definition.
2191       const Token &Tok = MI->getReplacementToken(TokNo);
2192       AddToken(Tok, Record);
2193       Stream.EmitRecord(PP_TOKEN, Record);
2194       Record.clear();
2195     }
2196     ++NumMacros;
2197   }
2198 
2199   Stream.ExitBlock();
2200 
2201   // Create the on-disk hash table in a buffer.
2202   SmallString<4096> MacroTable;
2203   uint32_t BucketOffset;
2204   {
2205     using namespace llvm::support;
2206     llvm::raw_svector_ostream Out(MacroTable);
2207     // Make sure that no bucket is at offset 0
2208     endian::Writer<little>(Out).write<uint32_t>(0);
2209     BucketOffset = Generator.Emit(Out);
2210   }
2211 
2212   // Write the macro table
2213   using namespace llvm;
2214   BitCodeAbbrev *Abbrev = new BitCodeAbbrev();
2215   Abbrev->Add(BitCodeAbbrevOp(MACRO_TABLE));
2216   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
2217   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
2218   unsigned MacroTableAbbrev = Stream.EmitAbbrev(Abbrev);
2219 
2220   Record.push_back(MACRO_TABLE);
2221   Record.push_back(BucketOffset);
2222   Stream.EmitRecordWithBlob(MacroTableAbbrev, Record, MacroTable.str());
2223   Record.clear();
2224 
2225   // Write the offsets table for macro IDs.
2226   using namespace llvm;
2227   Abbrev = new BitCodeAbbrev();
2228   Abbrev->Add(BitCodeAbbrevOp(MACRO_OFFSET));
2229   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // # of macros
2230   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // first ID
2231   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
2232 
2233   unsigned MacroOffsetAbbrev = Stream.EmitAbbrev(Abbrev);
2234   Record.clear();
2235   Record.push_back(MACRO_OFFSET);
2236   Record.push_back(MacroOffsets.size());
2237   Record.push_back(FirstMacroID - NUM_PREDEF_MACRO_IDS);
2238   Stream.EmitRecordWithBlob(MacroOffsetAbbrev, Record,
2239                             data(MacroOffsets));
2240 }
2241 
2242 void ASTWriter::WritePreprocessorDetail(PreprocessingRecord &PPRec) {
2243   if (PPRec.local_begin() == PPRec.local_end())
2244     return;
2245 
2246   SmallVector<PPEntityOffset, 64> PreprocessedEntityOffsets;
2247 
2248   // Enter the preprocessor block.
2249   Stream.EnterSubblock(PREPROCESSOR_DETAIL_BLOCK_ID, 3);
2250 
2251   // If the preprocessor has a preprocessing record, emit it.
2252   unsigned NumPreprocessingRecords = 0;
2253   using namespace llvm;
2254 
2255   // Set up the abbreviation for
2256   unsigned InclusionAbbrev = 0;
2257   {
2258     BitCodeAbbrev *Abbrev = new BitCodeAbbrev();
2259     Abbrev->Add(BitCodeAbbrevOp(PPD_INCLUSION_DIRECTIVE));
2260     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // filename length
2261     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // in quotes
2262     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2)); // kind
2263     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // imported module
2264     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
2265     InclusionAbbrev = Stream.EmitAbbrev(Abbrev);
2266   }
2267 
2268   unsigned FirstPreprocessorEntityID
2269     = (Chain ? PPRec.getNumLoadedPreprocessedEntities() : 0)
2270     + NUM_PREDEF_PP_ENTITY_IDS;
2271   unsigned NextPreprocessorEntityID = FirstPreprocessorEntityID;
2272   RecordData Record;
2273   for (PreprocessingRecord::iterator E = PPRec.local_begin(),
2274                                   EEnd = PPRec.local_end();
2275        E != EEnd;
2276        (void)++E, ++NumPreprocessingRecords, ++NextPreprocessorEntityID) {
2277     Record.clear();
2278 
2279     PreprocessedEntityOffsets.push_back(PPEntityOffset((*E)->getSourceRange(),
2280                                                      Stream.GetCurrentBitNo()));
2281 
2282     if (MacroDefinition *MD = dyn_cast<MacroDefinition>(*E)) {
2283       // Record this macro definition's ID.
2284       MacroDefinitions[MD] = NextPreprocessorEntityID;
2285 
2286       AddIdentifierRef(MD->getName(), Record);
2287       Stream.EmitRecord(PPD_MACRO_DEFINITION, Record);
2288       continue;
2289     }
2290 
2291     if (MacroExpansion *ME = dyn_cast<MacroExpansion>(*E)) {
2292       Record.push_back(ME->isBuiltinMacro());
2293       if (ME->isBuiltinMacro())
2294         AddIdentifierRef(ME->getName(), Record);
2295       else
2296         Record.push_back(MacroDefinitions[ME->getDefinition()]);
2297       Stream.EmitRecord(PPD_MACRO_EXPANSION, Record);
2298       continue;
2299     }
2300 
2301     if (InclusionDirective *ID = dyn_cast<InclusionDirective>(*E)) {
2302       Record.push_back(PPD_INCLUSION_DIRECTIVE);
2303       Record.push_back(ID->getFileName().size());
2304       Record.push_back(ID->wasInQuotes());
2305       Record.push_back(static_cast<unsigned>(ID->getKind()));
2306       Record.push_back(ID->importedModule());
2307       SmallString<64> Buffer;
2308       Buffer += ID->getFileName();
2309       // Check that the FileEntry is not null because it was not resolved and
2310       // we create a PCH even with compiler errors.
2311       if (ID->getFile())
2312         Buffer += ID->getFile()->getName();
2313       Stream.EmitRecordWithBlob(InclusionAbbrev, Record, Buffer);
2314       continue;
2315     }
2316 
2317     llvm_unreachable("Unhandled PreprocessedEntity in ASTWriter");
2318   }
2319   Stream.ExitBlock();
2320 
2321   // Write the offsets table for the preprocessing record.
2322   if (NumPreprocessingRecords > 0) {
2323     assert(PreprocessedEntityOffsets.size() == NumPreprocessingRecords);
2324 
2325     // Write the offsets table for identifier IDs.
2326     using namespace llvm;
2327     BitCodeAbbrev *Abbrev = new BitCodeAbbrev();
2328     Abbrev->Add(BitCodeAbbrevOp(PPD_ENTITIES_OFFSETS));
2329     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // first pp entity
2330     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
2331     unsigned PPEOffsetAbbrev = Stream.EmitAbbrev(Abbrev);
2332 
2333     Record.clear();
2334     Record.push_back(PPD_ENTITIES_OFFSETS);
2335     Record.push_back(FirstPreprocessorEntityID - NUM_PREDEF_PP_ENTITY_IDS);
2336     Stream.EmitRecordWithBlob(PPEOffsetAbbrev, Record,
2337                               data(PreprocessedEntityOffsets));
2338   }
2339 }
2340 
2341 unsigned ASTWriter::getSubmoduleID(Module *Mod) {
2342   llvm::DenseMap<Module *, unsigned>::iterator Known = SubmoduleIDs.find(Mod);
2343   if (Known != SubmoduleIDs.end())
2344     return Known->second;
2345 
2346   return SubmoduleIDs[Mod] = NextSubmoduleID++;
2347 }
2348 
2349 unsigned ASTWriter::getExistingSubmoduleID(Module *Mod) const {
2350   if (!Mod)
2351     return 0;
2352 
2353   llvm::DenseMap<Module *, unsigned>::const_iterator
2354     Known = SubmoduleIDs.find(Mod);
2355   if (Known != SubmoduleIDs.end())
2356     return Known->second;
2357 
2358   return 0;
2359 }
2360 
2361 /// \brief Compute the number of modules within the given tree (including the
2362 /// given module).
2363 static unsigned getNumberOfModules(Module *Mod) {
2364   unsigned ChildModules = 0;
2365   for (Module::submodule_iterator Sub = Mod->submodule_begin(),
2366                                SubEnd = Mod->submodule_end();
2367        Sub != SubEnd; ++Sub)
2368     ChildModules += getNumberOfModules(*Sub);
2369 
2370   return ChildModules + 1;
2371 }
2372 
2373 void ASTWriter::WriteSubmodules(Module *WritingModule) {
2374   // Determine the dependencies of our module and each of it's submodules.
2375   // FIXME: This feels like it belongs somewhere else, but there are no
2376   // other consumers of this information.
2377   SourceManager &SrcMgr = PP->getSourceManager();
2378   ModuleMap &ModMap = PP->getHeaderSearchInfo().getModuleMap();
2379   for (const auto *I : Context->local_imports()) {
2380     if (Module *ImportedFrom
2381           = ModMap.inferModuleFromLocation(FullSourceLoc(I->getLocation(),
2382                                                          SrcMgr))) {
2383       ImportedFrom->Imports.push_back(I->getImportedModule());
2384     }
2385   }
2386 
2387   // Enter the submodule description block.
2388   Stream.EnterSubblock(SUBMODULE_BLOCK_ID, /*bits for abbreviations*/5);
2389 
2390   // Write the abbreviations needed for the submodules block.
2391   using namespace llvm;
2392   BitCodeAbbrev *Abbrev = new BitCodeAbbrev();
2393   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_DEFINITION));
2394   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // ID
2395   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Parent
2396   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsFramework
2397   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsExplicit
2398   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsSystem
2399   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsExternC
2400   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // InferSubmodules...
2401   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // InferExplicit...
2402   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // InferExportWild...
2403   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // ConfigMacrosExh...
2404   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Name
2405   unsigned DefinitionAbbrev = Stream.EmitAbbrev(Abbrev);
2406 
2407   Abbrev = new BitCodeAbbrev();
2408   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_UMBRELLA_HEADER));
2409   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Name
2410   unsigned UmbrellaAbbrev = Stream.EmitAbbrev(Abbrev);
2411 
2412   Abbrev = new BitCodeAbbrev();
2413   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_HEADER));
2414   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Name
2415   unsigned HeaderAbbrev = Stream.EmitAbbrev(Abbrev);
2416 
2417   Abbrev = new BitCodeAbbrev();
2418   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_TOPHEADER));
2419   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Name
2420   unsigned TopHeaderAbbrev = Stream.EmitAbbrev(Abbrev);
2421 
2422   Abbrev = new BitCodeAbbrev();
2423   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_UMBRELLA_DIR));
2424   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Name
2425   unsigned UmbrellaDirAbbrev = Stream.EmitAbbrev(Abbrev);
2426 
2427   Abbrev = new BitCodeAbbrev();
2428   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_REQUIRES));
2429   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // State
2430   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));     // Feature
2431   unsigned RequiresAbbrev = Stream.EmitAbbrev(Abbrev);
2432 
2433   Abbrev = new BitCodeAbbrev();
2434   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_EXCLUDED_HEADER));
2435   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Name
2436   unsigned ExcludedHeaderAbbrev = Stream.EmitAbbrev(Abbrev);
2437 
2438   Abbrev = new BitCodeAbbrev();
2439   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_TEXTUAL_HEADER));
2440   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Name
2441   unsigned TextualHeaderAbbrev = Stream.EmitAbbrev(Abbrev);
2442 
2443   Abbrev = new BitCodeAbbrev();
2444   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_PRIVATE_HEADER));
2445   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Name
2446   unsigned PrivateHeaderAbbrev = Stream.EmitAbbrev(Abbrev);
2447 
2448   Abbrev = new BitCodeAbbrev();
2449   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_PRIVATE_TEXTUAL_HEADER));
2450   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Name
2451   unsigned PrivateTextualHeaderAbbrev = Stream.EmitAbbrev(Abbrev);
2452 
2453   Abbrev = new BitCodeAbbrev();
2454   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_LINK_LIBRARY));
2455   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsFramework
2456   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));     // Name
2457   unsigned LinkLibraryAbbrev = Stream.EmitAbbrev(Abbrev);
2458 
2459   Abbrev = new BitCodeAbbrev();
2460   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_CONFIG_MACRO));
2461   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));    // Macro name
2462   unsigned ConfigMacroAbbrev = Stream.EmitAbbrev(Abbrev);
2463 
2464   Abbrev = new BitCodeAbbrev();
2465   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_CONFLICT));
2466   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));  // Other module
2467   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));    // Message
2468   unsigned ConflictAbbrev = Stream.EmitAbbrev(Abbrev);
2469 
2470   // Write the submodule metadata block.
2471   RecordData Record;
2472   Record.push_back(getNumberOfModules(WritingModule));
2473   Record.push_back(FirstSubmoduleID - NUM_PREDEF_SUBMODULE_IDS);
2474   Stream.EmitRecord(SUBMODULE_METADATA, Record);
2475 
2476   // Write all of the submodules.
2477   std::queue<Module *> Q;
2478   Q.push(WritingModule);
2479   while (!Q.empty()) {
2480     Module *Mod = Q.front();
2481     Q.pop();
2482     unsigned ID = getSubmoduleID(Mod);
2483 
2484     // Emit the definition of the block.
2485     Record.clear();
2486     Record.push_back(SUBMODULE_DEFINITION);
2487     Record.push_back(ID);
2488     if (Mod->Parent) {
2489       assert(SubmoduleIDs[Mod->Parent] && "Submodule parent not written?");
2490       Record.push_back(SubmoduleIDs[Mod->Parent]);
2491     } else {
2492       Record.push_back(0);
2493     }
2494     Record.push_back(Mod->IsFramework);
2495     Record.push_back(Mod->IsExplicit);
2496     Record.push_back(Mod->IsSystem);
2497     Record.push_back(Mod->IsExternC);
2498     Record.push_back(Mod->InferSubmodules);
2499     Record.push_back(Mod->InferExplicitSubmodules);
2500     Record.push_back(Mod->InferExportWildcard);
2501     Record.push_back(Mod->ConfigMacrosExhaustive);
2502     Stream.EmitRecordWithBlob(DefinitionAbbrev, Record, Mod->Name);
2503 
2504     // Emit the requirements.
2505     for (unsigned I = 0, N = Mod->Requirements.size(); I != N; ++I) {
2506       Record.clear();
2507       Record.push_back(SUBMODULE_REQUIRES);
2508       Record.push_back(Mod->Requirements[I].second);
2509       Stream.EmitRecordWithBlob(RequiresAbbrev, Record,
2510                                 Mod->Requirements[I].first);
2511     }
2512 
2513     // Emit the umbrella header, if there is one.
2514     if (const FileEntry *UmbrellaHeader = Mod->getUmbrellaHeader()) {
2515       Record.clear();
2516       Record.push_back(SUBMODULE_UMBRELLA_HEADER);
2517       Stream.EmitRecordWithBlob(UmbrellaAbbrev, Record,
2518                                 UmbrellaHeader->getName());
2519     } else if (const DirectoryEntry *UmbrellaDir = Mod->getUmbrellaDir()) {
2520       Record.clear();
2521       Record.push_back(SUBMODULE_UMBRELLA_DIR);
2522       Stream.EmitRecordWithBlob(UmbrellaDirAbbrev, Record,
2523                                 UmbrellaDir->getName());
2524     }
2525 
2526     // Emit the headers.
2527     struct {
2528       unsigned RecordKind;
2529       unsigned Abbrev;
2530       Module::HeaderKind HeaderKind;
2531     } HeaderLists[] = {
2532       {SUBMODULE_HEADER, HeaderAbbrev, Module::HK_Normal},
2533       {SUBMODULE_TEXTUAL_HEADER, TextualHeaderAbbrev, Module::HK_Textual},
2534       {SUBMODULE_PRIVATE_HEADER, PrivateHeaderAbbrev, Module::HK_Private},
2535       {SUBMODULE_PRIVATE_TEXTUAL_HEADER, PrivateTextualHeaderAbbrev,
2536         Module::HK_PrivateTextual},
2537       {SUBMODULE_EXCLUDED_HEADER, ExcludedHeaderAbbrev, Module::HK_Excluded}
2538     };
2539     for (auto &HL : HeaderLists) {
2540       Record.clear();
2541       Record.push_back(HL.RecordKind);
2542       for (auto &H : Mod->Headers[HL.HeaderKind])
2543         Stream.EmitRecordWithBlob(HL.Abbrev, Record, H.NameAsWritten);
2544     }
2545 
2546     // Emit the top headers.
2547     {
2548       auto TopHeaders = Mod->getTopHeaders(PP->getFileManager());
2549       Record.clear();
2550       Record.push_back(SUBMODULE_TOPHEADER);
2551       for (auto *H : TopHeaders)
2552         Stream.EmitRecordWithBlob(TopHeaderAbbrev, Record, H->getName());
2553     }
2554 
2555     // Emit the imports.
2556     if (!Mod->Imports.empty()) {
2557       Record.clear();
2558       for (unsigned I = 0, N = Mod->Imports.size(); I != N; ++I) {
2559         unsigned ImportedID = getSubmoduleID(Mod->Imports[I]);
2560         assert(ImportedID && "Unknown submodule!");
2561         Record.push_back(ImportedID);
2562       }
2563       Stream.EmitRecord(SUBMODULE_IMPORTS, Record);
2564     }
2565 
2566     // Emit the exports.
2567     if (!Mod->Exports.empty()) {
2568       Record.clear();
2569       for (unsigned I = 0, N = Mod->Exports.size(); I != N; ++I) {
2570         if (Module *Exported = Mod->Exports[I].getPointer()) {
2571           unsigned ExportedID = SubmoduleIDs[Exported];
2572           assert(ExportedID > 0 && "Unknown submodule ID?");
2573           Record.push_back(ExportedID);
2574         } else {
2575           Record.push_back(0);
2576         }
2577 
2578         Record.push_back(Mod->Exports[I].getInt());
2579       }
2580       Stream.EmitRecord(SUBMODULE_EXPORTS, Record);
2581     }
2582 
2583     //FIXME: How do we emit the 'use'd modules?  They may not be submodules.
2584     // Might be unnecessary as use declarations are only used to build the
2585     // module itself.
2586 
2587     // Emit the link libraries.
2588     for (unsigned I = 0, N = Mod->LinkLibraries.size(); I != N; ++I) {
2589       Record.clear();
2590       Record.push_back(SUBMODULE_LINK_LIBRARY);
2591       Record.push_back(Mod->LinkLibraries[I].IsFramework);
2592       Stream.EmitRecordWithBlob(LinkLibraryAbbrev, Record,
2593                                 Mod->LinkLibraries[I].Library);
2594     }
2595 
2596     // Emit the conflicts.
2597     for (unsigned I = 0, N = Mod->Conflicts.size(); I != N; ++I) {
2598       Record.clear();
2599       Record.push_back(SUBMODULE_CONFLICT);
2600       unsigned OtherID = getSubmoduleID(Mod->Conflicts[I].Other);
2601       assert(OtherID && "Unknown submodule!");
2602       Record.push_back(OtherID);
2603       Stream.EmitRecordWithBlob(ConflictAbbrev, Record,
2604                                 Mod->Conflicts[I].Message);
2605     }
2606 
2607     // Emit the configuration macros.
2608     for (unsigned I = 0, N =  Mod->ConfigMacros.size(); I != N; ++I) {
2609       Record.clear();
2610       Record.push_back(SUBMODULE_CONFIG_MACRO);
2611       Stream.EmitRecordWithBlob(ConfigMacroAbbrev, Record,
2612                                 Mod->ConfigMacros[I]);
2613     }
2614 
2615     // Queue up the submodules of this module.
2616     for (Module::submodule_iterator Sub = Mod->submodule_begin(),
2617                                  SubEnd = Mod->submodule_end();
2618          Sub != SubEnd; ++Sub)
2619       Q.push(*Sub);
2620   }
2621 
2622   Stream.ExitBlock();
2623 
2624   assert((NextSubmoduleID - FirstSubmoduleID
2625             == getNumberOfModules(WritingModule)) && "Wrong # of submodules");
2626 }
2627 
2628 serialization::SubmoduleID
2629 ASTWriter::inferSubmoduleIDFromLocation(SourceLocation Loc) {
2630   if (Loc.isInvalid() || !WritingModule)
2631     return 0; // No submodule
2632 
2633   // Find the module that owns this location.
2634   ModuleMap &ModMap = PP->getHeaderSearchInfo().getModuleMap();
2635   Module *OwningMod
2636     = ModMap.inferModuleFromLocation(FullSourceLoc(Loc,PP->getSourceManager()));
2637   if (!OwningMod)
2638     return 0;
2639 
2640   // Check whether this submodule is part of our own module.
2641   if (WritingModule != OwningMod && !OwningMod->isSubModuleOf(WritingModule))
2642     return 0;
2643 
2644   return getSubmoduleID(OwningMod);
2645 }
2646 
2647 void ASTWriter::WritePragmaDiagnosticMappings(const DiagnosticsEngine &Diag,
2648                                               bool isModule) {
2649   // Make sure set diagnostic pragmas don't affect the translation unit that
2650   // imports the module.
2651   // FIXME: Make diagnostic pragma sections work properly with modules.
2652   if (isModule)
2653     return;
2654 
2655   llvm::SmallDenseMap<const DiagnosticsEngine::DiagState *, unsigned, 64>
2656       DiagStateIDMap;
2657   unsigned CurrID = 0;
2658   DiagStateIDMap[&Diag.DiagStates.front()] = ++CurrID; // the command-line one.
2659   RecordData Record;
2660   for (DiagnosticsEngine::DiagStatePointsTy::const_iterator
2661          I = Diag.DiagStatePoints.begin(), E = Diag.DiagStatePoints.end();
2662          I != E; ++I) {
2663     const DiagnosticsEngine::DiagStatePoint &point = *I;
2664     if (point.Loc.isInvalid())
2665       continue;
2666 
2667     Record.push_back(point.Loc.getRawEncoding());
2668     unsigned &DiagStateID = DiagStateIDMap[point.State];
2669     Record.push_back(DiagStateID);
2670 
2671     if (DiagStateID == 0) {
2672       DiagStateID = ++CurrID;
2673       for (DiagnosticsEngine::DiagState::const_iterator
2674              I = point.State->begin(), E = point.State->end(); I != E; ++I) {
2675         if (I->second.isPragma()) {
2676           Record.push_back(I->first);
2677           Record.push_back((unsigned)I->second.getSeverity());
2678         }
2679       }
2680       Record.push_back(-1); // mark the end of the diag/map pairs for this
2681                             // location.
2682     }
2683   }
2684 
2685   if (!Record.empty())
2686     Stream.EmitRecord(DIAG_PRAGMA_MAPPINGS, Record);
2687 }
2688 
2689 void ASTWriter::WriteCXXBaseSpecifiersOffsets() {
2690   if (CXXBaseSpecifiersOffsets.empty())
2691     return;
2692 
2693   RecordData Record;
2694 
2695   // Create a blob abbreviation for the C++ base specifiers offsets.
2696   using namespace llvm;
2697 
2698   BitCodeAbbrev *Abbrev = new BitCodeAbbrev();
2699   Abbrev->Add(BitCodeAbbrevOp(CXX_BASE_SPECIFIER_OFFSETS));
2700   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // size
2701   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
2702   unsigned BaseSpecifierOffsetAbbrev = Stream.EmitAbbrev(Abbrev);
2703 
2704   // Write the base specifier offsets table.
2705   Record.clear();
2706   Record.push_back(CXX_BASE_SPECIFIER_OFFSETS);
2707   Record.push_back(CXXBaseSpecifiersOffsets.size());
2708   Stream.EmitRecordWithBlob(BaseSpecifierOffsetAbbrev, Record,
2709                             data(CXXBaseSpecifiersOffsets));
2710 }
2711 
2712 //===----------------------------------------------------------------------===//
2713 // Type Serialization
2714 //===----------------------------------------------------------------------===//
2715 
2716 /// \brief Write the representation of a type to the AST stream.
2717 void ASTWriter::WriteType(QualType T) {
2718   TypeIdx &Idx = TypeIdxs[T];
2719   if (Idx.getIndex() == 0) // we haven't seen this type before.
2720     Idx = TypeIdx(NextTypeID++);
2721 
2722   assert(Idx.getIndex() >= FirstTypeID && "Re-writing a type from a prior AST");
2723 
2724   // Record the offset for this type.
2725   unsigned Index = Idx.getIndex() - FirstTypeID;
2726   if (TypeOffsets.size() == Index)
2727     TypeOffsets.push_back(Stream.GetCurrentBitNo());
2728   else if (TypeOffsets.size() < Index) {
2729     TypeOffsets.resize(Index + 1);
2730     TypeOffsets[Index] = Stream.GetCurrentBitNo();
2731   }
2732 
2733   RecordData Record;
2734 
2735   // Emit the type's representation.
2736   ASTTypeWriter W(*this, Record);
2737   W.AbbrevToUse = 0;
2738 
2739   if (T.hasLocalNonFastQualifiers()) {
2740     Qualifiers Qs = T.getLocalQualifiers();
2741     AddTypeRef(T.getLocalUnqualifiedType(), Record);
2742     Record.push_back(Qs.getAsOpaqueValue());
2743     W.Code = TYPE_EXT_QUAL;
2744     W.AbbrevToUse = TypeExtQualAbbrev;
2745   } else {
2746     switch (T->getTypeClass()) {
2747       // For all of the concrete, non-dependent types, call the
2748       // appropriate visitor function.
2749 #define TYPE(Class, Base) \
2750     case Type::Class: W.Visit##Class##Type(cast<Class##Type>(T)); break;
2751 #define ABSTRACT_TYPE(Class, Base)
2752 #include "clang/AST/TypeNodes.def"
2753     }
2754   }
2755 
2756   // Emit the serialized record.
2757   Stream.EmitRecord(W.Code, Record, W.AbbrevToUse);
2758 
2759   // Flush any expressions that were written as part of this type.
2760   FlushStmts();
2761 }
2762 
2763 //===----------------------------------------------------------------------===//
2764 // Declaration Serialization
2765 //===----------------------------------------------------------------------===//
2766 
2767 /// \brief Write the block containing all of the declaration IDs
2768 /// lexically declared within the given DeclContext.
2769 ///
2770 /// \returns the offset of the DECL_CONTEXT_LEXICAL block within the
2771 /// bistream, or 0 if no block was written.
2772 uint64_t ASTWriter::WriteDeclContextLexicalBlock(ASTContext &Context,
2773                                                  DeclContext *DC) {
2774   if (DC->decls_empty())
2775     return 0;
2776 
2777   uint64_t Offset = Stream.GetCurrentBitNo();
2778   RecordData Record;
2779   Record.push_back(DECL_CONTEXT_LEXICAL);
2780   SmallVector<KindDeclIDPair, 64> Decls;
2781   for (const auto *D : DC->decls())
2782     Decls.push_back(std::make_pair(D->getKind(), GetDeclRef(D)));
2783 
2784   ++NumLexicalDeclContexts;
2785   Stream.EmitRecordWithBlob(DeclContextLexicalAbbrev, Record, data(Decls));
2786   return Offset;
2787 }
2788 
2789 void ASTWriter::WriteTypeDeclOffsets() {
2790   using namespace llvm;
2791   RecordData Record;
2792 
2793   // Write the type offsets array
2794   BitCodeAbbrev *Abbrev = new BitCodeAbbrev();
2795   Abbrev->Add(BitCodeAbbrevOp(TYPE_OFFSET));
2796   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // # of types
2797   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // base type index
2798   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // types block
2799   unsigned TypeOffsetAbbrev = Stream.EmitAbbrev(Abbrev);
2800   Record.clear();
2801   Record.push_back(TYPE_OFFSET);
2802   Record.push_back(TypeOffsets.size());
2803   Record.push_back(FirstTypeID - NUM_PREDEF_TYPE_IDS);
2804   Stream.EmitRecordWithBlob(TypeOffsetAbbrev, Record, data(TypeOffsets));
2805 
2806   // Write the declaration offsets array
2807   Abbrev = new BitCodeAbbrev();
2808   Abbrev->Add(BitCodeAbbrevOp(DECL_OFFSET));
2809   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // # of declarations
2810   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // base decl ID
2811   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // declarations block
2812   unsigned DeclOffsetAbbrev = Stream.EmitAbbrev(Abbrev);
2813   Record.clear();
2814   Record.push_back(DECL_OFFSET);
2815   Record.push_back(DeclOffsets.size());
2816   Record.push_back(FirstDeclID - NUM_PREDEF_DECL_IDS);
2817   Stream.EmitRecordWithBlob(DeclOffsetAbbrev, Record, data(DeclOffsets));
2818 }
2819 
2820 void ASTWriter::WriteFileDeclIDsMap() {
2821   using namespace llvm;
2822   RecordData Record;
2823 
2824   // Join the vectors of DeclIDs from all files.
2825   SmallVector<DeclID, 256> FileSortedIDs;
2826   for (FileDeclIDsTy::iterator
2827          FI = FileDeclIDs.begin(), FE = FileDeclIDs.end(); FI != FE; ++FI) {
2828     DeclIDInFileInfo &Info = *FI->second;
2829     Info.FirstDeclIndex = FileSortedIDs.size();
2830     for (LocDeclIDsTy::iterator
2831            DI = Info.DeclIDs.begin(), DE = Info.DeclIDs.end(); DI != DE; ++DI)
2832       FileSortedIDs.push_back(DI->second);
2833   }
2834 
2835   BitCodeAbbrev *Abbrev = new BitCodeAbbrev();
2836   Abbrev->Add(BitCodeAbbrevOp(FILE_SORTED_DECLS));
2837   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
2838   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
2839   unsigned AbbrevCode = Stream.EmitAbbrev(Abbrev);
2840   Record.push_back(FILE_SORTED_DECLS);
2841   Record.push_back(FileSortedIDs.size());
2842   Stream.EmitRecordWithBlob(AbbrevCode, Record, data(FileSortedIDs));
2843 }
2844 
2845 void ASTWriter::WriteComments() {
2846   Stream.EnterSubblock(COMMENTS_BLOCK_ID, 3);
2847   ArrayRef<RawComment *> RawComments = Context->Comments.getComments();
2848   RecordData Record;
2849   for (ArrayRef<RawComment *>::iterator I = RawComments.begin(),
2850                                         E = RawComments.end();
2851        I != E; ++I) {
2852     Record.clear();
2853     AddSourceRange((*I)->getSourceRange(), Record);
2854     Record.push_back((*I)->getKind());
2855     Record.push_back((*I)->isTrailingComment());
2856     Record.push_back((*I)->isAlmostTrailingComment());
2857     Stream.EmitRecord(COMMENTS_RAW_COMMENT, Record);
2858   }
2859   Stream.ExitBlock();
2860 }
2861 
2862 //===----------------------------------------------------------------------===//
2863 // Global Method Pool and Selector Serialization
2864 //===----------------------------------------------------------------------===//
2865 
2866 namespace {
2867 // Trait used for the on-disk hash table used in the method pool.
2868 class ASTMethodPoolTrait {
2869   ASTWriter &Writer;
2870 
2871 public:
2872   typedef Selector key_type;
2873   typedef key_type key_type_ref;
2874 
2875   struct data_type {
2876     SelectorID ID;
2877     ObjCMethodList Instance, Factory;
2878   };
2879   typedef const data_type& data_type_ref;
2880 
2881   typedef unsigned hash_value_type;
2882   typedef unsigned offset_type;
2883 
2884   explicit ASTMethodPoolTrait(ASTWriter &Writer) : Writer(Writer) { }
2885 
2886   static hash_value_type ComputeHash(Selector Sel) {
2887     return serialization::ComputeHash(Sel);
2888   }
2889 
2890   std::pair<unsigned,unsigned>
2891     EmitKeyDataLength(raw_ostream& Out, Selector Sel,
2892                       data_type_ref Methods) {
2893     using namespace llvm::support;
2894     endian::Writer<little> LE(Out);
2895     unsigned KeyLen = 2 + (Sel.getNumArgs()? Sel.getNumArgs() * 4 : 4);
2896     LE.write<uint16_t>(KeyLen);
2897     unsigned DataLen = 4 + 2 + 2; // 2 bytes for each of the method counts
2898     for (const ObjCMethodList *Method = &Methods.Instance; Method;
2899          Method = Method->getNext())
2900       if (Method->getMethod())
2901         DataLen += 4;
2902     for (const ObjCMethodList *Method = &Methods.Factory; Method;
2903          Method = Method->getNext())
2904       if (Method->getMethod())
2905         DataLen += 4;
2906     LE.write<uint16_t>(DataLen);
2907     return std::make_pair(KeyLen, DataLen);
2908   }
2909 
2910   void EmitKey(raw_ostream& Out, Selector Sel, unsigned) {
2911     using namespace llvm::support;
2912     endian::Writer<little> LE(Out);
2913     uint64_t Start = Out.tell();
2914     assert((Start >> 32) == 0 && "Selector key offset too large");
2915     Writer.SetSelectorOffset(Sel, Start);
2916     unsigned N = Sel.getNumArgs();
2917     LE.write<uint16_t>(N);
2918     if (N == 0)
2919       N = 1;
2920     for (unsigned I = 0; I != N; ++I)
2921       LE.write<uint32_t>(
2922           Writer.getIdentifierRef(Sel.getIdentifierInfoForSlot(I)));
2923   }
2924 
2925   void EmitData(raw_ostream& Out, key_type_ref,
2926                 data_type_ref Methods, unsigned DataLen) {
2927     using namespace llvm::support;
2928     endian::Writer<little> LE(Out);
2929     uint64_t Start = Out.tell(); (void)Start;
2930     LE.write<uint32_t>(Methods.ID);
2931     unsigned NumInstanceMethods = 0;
2932     for (const ObjCMethodList *Method = &Methods.Instance; Method;
2933          Method = Method->getNext())
2934       if (Method->getMethod())
2935         ++NumInstanceMethods;
2936 
2937     unsigned NumFactoryMethods = 0;
2938     for (const ObjCMethodList *Method = &Methods.Factory; Method;
2939          Method = Method->getNext())
2940       if (Method->getMethod())
2941         ++NumFactoryMethods;
2942 
2943     unsigned InstanceBits = Methods.Instance.getBits();
2944     assert(InstanceBits < 4);
2945     unsigned InstanceHasMoreThanOneDeclBit =
2946         Methods.Instance.hasMoreThanOneDecl();
2947     unsigned FullInstanceBits = (NumInstanceMethods << 3) |
2948                                 (InstanceHasMoreThanOneDeclBit << 2) |
2949                                 InstanceBits;
2950     unsigned FactoryBits = Methods.Factory.getBits();
2951     assert(FactoryBits < 4);
2952     unsigned FactoryHasMoreThanOneDeclBit =
2953         Methods.Factory.hasMoreThanOneDecl();
2954     unsigned FullFactoryBits = (NumFactoryMethods << 3) |
2955                                (FactoryHasMoreThanOneDeclBit << 2) |
2956                                FactoryBits;
2957     LE.write<uint16_t>(FullInstanceBits);
2958     LE.write<uint16_t>(FullFactoryBits);
2959     for (const ObjCMethodList *Method = &Methods.Instance; Method;
2960          Method = Method->getNext())
2961       if (Method->getMethod())
2962         LE.write<uint32_t>(Writer.getDeclID(Method->getMethod()));
2963     for (const ObjCMethodList *Method = &Methods.Factory; Method;
2964          Method = Method->getNext())
2965       if (Method->getMethod())
2966         LE.write<uint32_t>(Writer.getDeclID(Method->getMethod()));
2967 
2968     assert(Out.tell() - Start == DataLen && "Data length is wrong");
2969   }
2970 };
2971 } // end anonymous namespace
2972 
2973 /// \brief Write ObjC data: selectors and the method pool.
2974 ///
2975 /// The method pool contains both instance and factory methods, stored
2976 /// in an on-disk hash table indexed by the selector. The hash table also
2977 /// contains an empty entry for every other selector known to Sema.
2978 void ASTWriter::WriteSelectors(Sema &SemaRef) {
2979   using namespace llvm;
2980 
2981   // Do we have to do anything at all?
2982   if (SemaRef.MethodPool.empty() && SelectorIDs.empty())
2983     return;
2984   unsigned NumTableEntries = 0;
2985   // Create and write out the blob that contains selectors and the method pool.
2986   {
2987     llvm::OnDiskChainedHashTableGenerator<ASTMethodPoolTrait> Generator;
2988     ASTMethodPoolTrait Trait(*this);
2989 
2990     // Create the on-disk hash table representation. We walk through every
2991     // selector we've seen and look it up in the method pool.
2992     SelectorOffsets.resize(NextSelectorID - FirstSelectorID);
2993     for (llvm::DenseMap<Selector, SelectorID>::iterator
2994              I = SelectorIDs.begin(), E = SelectorIDs.end();
2995          I != E; ++I) {
2996       Selector S = I->first;
2997       Sema::GlobalMethodPool::iterator F = SemaRef.MethodPool.find(S);
2998       ASTMethodPoolTrait::data_type Data = {
2999         I->second,
3000         ObjCMethodList(),
3001         ObjCMethodList()
3002       };
3003       if (F != SemaRef.MethodPool.end()) {
3004         Data.Instance = F->second.first;
3005         Data.Factory = F->second.second;
3006       }
3007       // Only write this selector if it's not in an existing AST or something
3008       // changed.
3009       if (Chain && I->second < FirstSelectorID) {
3010         // Selector already exists. Did it change?
3011         bool changed = false;
3012         for (ObjCMethodList *M = &Data.Instance;
3013              !changed && M && M->getMethod(); M = M->getNext()) {
3014           if (!M->getMethod()->isFromASTFile())
3015             changed = true;
3016         }
3017         for (ObjCMethodList *M = &Data.Factory; !changed && M && M->getMethod();
3018              M = M->getNext()) {
3019           if (!M->getMethod()->isFromASTFile())
3020             changed = true;
3021         }
3022         if (!changed)
3023           continue;
3024       } else if (Data.Instance.getMethod() || Data.Factory.getMethod()) {
3025         // A new method pool entry.
3026         ++NumTableEntries;
3027       }
3028       Generator.insert(S, Data, Trait);
3029     }
3030 
3031     // Create the on-disk hash table in a buffer.
3032     SmallString<4096> MethodPool;
3033     uint32_t BucketOffset;
3034     {
3035       using namespace llvm::support;
3036       ASTMethodPoolTrait Trait(*this);
3037       llvm::raw_svector_ostream Out(MethodPool);
3038       // Make sure that no bucket is at offset 0
3039       endian::Writer<little>(Out).write<uint32_t>(0);
3040       BucketOffset = Generator.Emit(Out, Trait);
3041     }
3042 
3043     // Create a blob abbreviation
3044     BitCodeAbbrev *Abbrev = new BitCodeAbbrev();
3045     Abbrev->Add(BitCodeAbbrevOp(METHOD_POOL));
3046     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
3047     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
3048     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
3049     unsigned MethodPoolAbbrev = Stream.EmitAbbrev(Abbrev);
3050 
3051     // Write the method pool
3052     RecordData Record;
3053     Record.push_back(METHOD_POOL);
3054     Record.push_back(BucketOffset);
3055     Record.push_back(NumTableEntries);
3056     Stream.EmitRecordWithBlob(MethodPoolAbbrev, Record, MethodPool.str());
3057 
3058     // Create a blob abbreviation for the selector table offsets.
3059     Abbrev = new BitCodeAbbrev();
3060     Abbrev->Add(BitCodeAbbrevOp(SELECTOR_OFFSETS));
3061     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // size
3062     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // first ID
3063     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
3064     unsigned SelectorOffsetAbbrev = Stream.EmitAbbrev(Abbrev);
3065 
3066     // Write the selector offsets table.
3067     Record.clear();
3068     Record.push_back(SELECTOR_OFFSETS);
3069     Record.push_back(SelectorOffsets.size());
3070     Record.push_back(FirstSelectorID - NUM_PREDEF_SELECTOR_IDS);
3071     Stream.EmitRecordWithBlob(SelectorOffsetAbbrev, Record,
3072                               data(SelectorOffsets));
3073   }
3074 }
3075 
3076 /// \brief Write the selectors referenced in @selector expression into AST file.
3077 void ASTWriter::WriteReferencedSelectorsPool(Sema &SemaRef) {
3078   using namespace llvm;
3079   if (SemaRef.ReferencedSelectors.empty())
3080     return;
3081 
3082   RecordData Record;
3083 
3084   // Note: this writes out all references even for a dependent AST. But it is
3085   // very tricky to fix, and given that @selector shouldn't really appear in
3086   // headers, probably not worth it. It's not a correctness issue.
3087   for (DenseMap<Selector, SourceLocation>::iterator S =
3088        SemaRef.ReferencedSelectors.begin(),
3089        E = SemaRef.ReferencedSelectors.end(); S != E; ++S) {
3090     Selector Sel = (*S).first;
3091     SourceLocation Loc = (*S).second;
3092     AddSelectorRef(Sel, Record);
3093     AddSourceLocation(Loc, Record);
3094   }
3095   Stream.EmitRecord(REFERENCED_SELECTOR_POOL, Record);
3096 }
3097 
3098 //===----------------------------------------------------------------------===//
3099 // Identifier Table Serialization
3100 //===----------------------------------------------------------------------===//
3101 
3102 /// Determine the declaration that should be put into the name lookup table to
3103 /// represent the given declaration in this module. This is usually D itself,
3104 /// but if D was imported and merged into a local declaration, we want the most
3105 /// recent local declaration instead. The chosen declaration will be the most
3106 /// recent declaration in any module that imports this one.
3107 static NamedDecl *getDeclForLocalLookup(const LangOptions &LangOpts,
3108                                         NamedDecl *D) {
3109   if (!LangOpts.Modules || !D->isFromASTFile())
3110     return D;
3111 
3112   if (Decl *Redecl = D->getPreviousDecl()) {
3113     // For Redeclarable decls, a prior declaration might be local.
3114     for (; Redecl; Redecl = Redecl->getPreviousDecl()) {
3115       if (!Redecl->isFromASTFile())
3116         return cast<NamedDecl>(Redecl);
3117       // If we come up a decl from a (chained-)PCH stop since we won't find a
3118       // local one.
3119       if (D->getOwningModuleID() == 0)
3120         break;
3121     }
3122   } else if (Decl *First = D->getCanonicalDecl()) {
3123     // For Mergeable decls, the first decl might be local.
3124     if (!First->isFromASTFile())
3125       return cast<NamedDecl>(First);
3126   }
3127 
3128   // All declarations are imported. Our most recent declaration will also be
3129   // the most recent one in anyone who imports us.
3130   return D;
3131 }
3132 
3133 namespace {
3134 class ASTIdentifierTableTrait {
3135   ASTWriter &Writer;
3136   Preprocessor &PP;
3137   IdentifierResolver &IdResolver;
3138   bool IsModule;
3139 
3140   /// \brief Determines whether this is an "interesting" identifier
3141   /// that needs a full IdentifierInfo structure written into the hash
3142   /// table.
3143   bool isInterestingIdentifier(IdentifierInfo *II, MacroDirective *&Macro) {
3144     if (II->isPoisoned() ||
3145         II->isExtensionToken() ||
3146         II->getObjCOrBuiltinID() ||
3147         II->hasRevertedTokenIDToIdentifier() ||
3148         II->getFETokenInfo<void>())
3149       return true;
3150 
3151     return hadMacroDefinition(II, Macro);
3152   }
3153 
3154   bool hadMacroDefinition(IdentifierInfo *II, MacroDirective *&Macro) {
3155     if (!II->hadMacroDefinition())
3156       return false;
3157 
3158     if (Macro || (Macro = PP.getMacroDirectiveHistory(II))) {
3159       if (!IsModule)
3160         return !shouldIgnoreMacro(Macro, IsModule, PP);
3161 
3162       MacroState State;
3163       if (getFirstPublicSubmoduleMacro(Macro, State))
3164         return true;
3165     }
3166 
3167     return false;
3168   }
3169 
3170   enum class SubmoduleMacroState {
3171     /// We've seen nothing about this macro.
3172     None,
3173     /// We've seen a public visibility directive.
3174     Public,
3175     /// We've either exported a macro for this module or found that the
3176     /// module's definition of this macro is private.
3177     Done
3178   };
3179   typedef llvm::DenseMap<SubmoduleID, SubmoduleMacroState> MacroState;
3180 
3181   MacroDirective *
3182   getFirstPublicSubmoduleMacro(MacroDirective *MD, MacroState &State) {
3183     if (MacroDirective *NextMD = getPublicSubmoduleMacro(MD, State))
3184       return NextMD;
3185     return nullptr;
3186   }
3187 
3188   MacroDirective *
3189   getNextPublicSubmoduleMacro(MacroDirective *MD, MacroState &State) {
3190     if (MacroDirective *NextMD =
3191             getPublicSubmoduleMacro(MD->getPrevious(), State))
3192       return NextMD;
3193     return nullptr;
3194   }
3195 
3196   /// \brief Traverses the macro directives history and returns the next
3197   /// public macro definition or undefinition that has not been found so far.
3198   ///
3199   /// A macro that is defined in submodule A and undefined in submodule B
3200   /// will still be considered as defined/exported from submodule A.
3201   MacroDirective *getPublicSubmoduleMacro(MacroDirective *MD,
3202                                           MacroState &State) {
3203     if (!MD)
3204       return nullptr;
3205 
3206     Optional<bool> IsPublic;
3207     for (; MD; MD = MD->getPrevious()) {
3208       // Once we hit an ignored macro, we're done: the rest of the chain
3209       // will all be ignored macros.
3210       if (shouldIgnoreMacro(MD, IsModule, PP))
3211         break;
3212 
3213       // If this macro was imported, re-export it.
3214       if (MD->isImported())
3215         return MD;
3216 
3217       SubmoduleID ModID = getSubmoduleID(MD);
3218       auto &S = State[ModID];
3219       assert(ModID && "found macro in no submodule");
3220 
3221       if (S == SubmoduleMacroState::Done)
3222         continue;
3223 
3224       if (auto *VisMD = dyn_cast<VisibilityMacroDirective>(MD)) {
3225         // The latest visibility directive for a name in a submodule affects all
3226         // the directives that come before it.
3227         if (S == SubmoduleMacroState::None)
3228           S = VisMD->isPublic() ? SubmoduleMacroState::Public
3229                                 : SubmoduleMacroState::Done;
3230       } else {
3231         S = SubmoduleMacroState::Done;
3232         return MD;
3233       }
3234     }
3235 
3236     return nullptr;
3237   }
3238 
3239   ArrayRef<SubmoduleID>
3240   getOverriddenSubmodules(MacroDirective *MD,
3241                           SmallVectorImpl<SubmoduleID> &ScratchSpace) {
3242     assert(!isa<VisibilityMacroDirective>(MD) &&
3243            "only #define and #undef can override");
3244     if (MD->isImported())
3245       return MD->getOverriddenModules();
3246 
3247     ScratchSpace.clear();
3248     SubmoduleID ModID = getSubmoduleID(MD);
3249     for (MD = MD->getPrevious(); MD; MD = MD->getPrevious()) {
3250       if (shouldIgnoreMacro(MD, IsModule, PP))
3251         break;
3252 
3253       // If this is a definition from a submodule import, that submodule's
3254       // definition is overridden by the definition or undefinition that we
3255       // started with.
3256       if (MD->isImported()) {
3257         if (auto *DefMD = dyn_cast<DefMacroDirective>(MD)) {
3258           SubmoduleID DefModuleID = DefMD->getInfo()->getOwningModuleID();
3259           assert(DefModuleID && "imported macro has no owning module");
3260           ScratchSpace.push_back(DefModuleID);
3261         } else if (auto *UndefMD = dyn_cast<UndefMacroDirective>(MD)) {
3262           // If we override a #undef, we override anything that #undef overrides.
3263           // We don't need to override it, since an active #undef doesn't affect
3264           // the meaning of a macro.
3265           auto Overrides = UndefMD->getOverriddenModules();
3266           ScratchSpace.insert(ScratchSpace.end(),
3267                               Overrides.begin(), Overrides.end());
3268         }
3269       }
3270 
3271       // Stop once we leave the original macro's submodule.
3272       //
3273       // Either this submodule #included another submodule of the same
3274       // module or it just happened to be built after the other module.
3275       // In the former case, we override the submodule's macro.
3276       //
3277       // FIXME: In the latter case, we shouldn't do so, but we can't tell
3278       // these cases apart.
3279       //
3280       // FIXME: We can leave this submodule and re-enter it if it #includes a
3281       // header within a different submodule of the same module. In such cases
3282       // the overrides list will be incomplete.
3283       SubmoduleID DirectiveModuleID = getSubmoduleID(MD);
3284       if (DirectiveModuleID != ModID) {
3285         if (DirectiveModuleID && !MD->isImported())
3286           ScratchSpace.push_back(DirectiveModuleID);
3287         break;
3288       }
3289     }
3290 
3291     std::sort(ScratchSpace.begin(), ScratchSpace.end());
3292     ScratchSpace.erase(std::unique(ScratchSpace.begin(), ScratchSpace.end()),
3293                        ScratchSpace.end());
3294     return ScratchSpace;
3295   }
3296 
3297   SubmoduleID getSubmoduleID(MacroDirective *MD) {
3298     return Writer.inferSubmoduleIDFromLocation(MD->getLocation());
3299   }
3300 
3301 public:
3302   typedef IdentifierInfo* key_type;
3303   typedef key_type  key_type_ref;
3304 
3305   typedef IdentID data_type;
3306   typedef data_type data_type_ref;
3307 
3308   typedef unsigned hash_value_type;
3309   typedef unsigned offset_type;
3310 
3311   ASTIdentifierTableTrait(ASTWriter &Writer, Preprocessor &PP,
3312                           IdentifierResolver &IdResolver, bool IsModule)
3313     : Writer(Writer), PP(PP), IdResolver(IdResolver), IsModule(IsModule) { }
3314 
3315   static hash_value_type ComputeHash(const IdentifierInfo* II) {
3316     return llvm::HashString(II->getName());
3317   }
3318 
3319   std::pair<unsigned,unsigned>
3320   EmitKeyDataLength(raw_ostream& Out, IdentifierInfo* II, IdentID ID) {
3321     unsigned KeyLen = II->getLength() + 1;
3322     unsigned DataLen = 4; // 4 bytes for the persistent ID << 1
3323     MacroDirective *Macro = nullptr;
3324     if (isInterestingIdentifier(II, Macro)) {
3325       DataLen += 2; // 2 bytes for builtin ID
3326       DataLen += 2; // 2 bytes for flags
3327       if (hadMacroDefinition(II, Macro)) {
3328         DataLen += 4; // MacroDirectives offset.
3329         if (IsModule) {
3330           MacroState State;
3331           SmallVector<SubmoduleID, 16> Scratch;
3332           for (MacroDirective *MD = getFirstPublicSubmoduleMacro(Macro, State);
3333                MD; MD = getNextPublicSubmoduleMacro(MD, State)) {
3334             DataLen += 4; // MacroInfo ID or ModuleID.
3335             if (unsigned NumOverrides =
3336                     getOverriddenSubmodules(MD, Scratch).size())
3337               DataLen += 4 * (1 + NumOverrides);
3338           }
3339           DataLen += 4; // 0 terminator.
3340         }
3341       }
3342 
3343       for (IdentifierResolver::iterator D = IdResolver.begin(II),
3344                                      DEnd = IdResolver.end();
3345            D != DEnd; ++D)
3346         DataLen += 4;
3347     }
3348     using namespace llvm::support;
3349     endian::Writer<little> LE(Out);
3350 
3351     LE.write<uint16_t>(DataLen);
3352     // We emit the key length after the data length so that every
3353     // string is preceded by a 16-bit length. This matches the PTH
3354     // format for storing identifiers.
3355     LE.write<uint16_t>(KeyLen);
3356     return std::make_pair(KeyLen, DataLen);
3357   }
3358 
3359   void EmitKey(raw_ostream& Out, const IdentifierInfo* II,
3360                unsigned KeyLen) {
3361     // Record the location of the key data.  This is used when generating
3362     // the mapping from persistent IDs to strings.
3363     Writer.SetIdentifierOffset(II, Out.tell());
3364     Out.write(II->getNameStart(), KeyLen);
3365   }
3366 
3367   static void emitMacroOverrides(raw_ostream &Out,
3368                                  ArrayRef<SubmoduleID> Overridden) {
3369     if (!Overridden.empty()) {
3370       using namespace llvm::support;
3371       endian::Writer<little> LE(Out);
3372       LE.write<uint32_t>(Overridden.size() | 0x80000000U);
3373       for (unsigned I = 0, N = Overridden.size(); I != N; ++I) {
3374         assert(Overridden[I] && "zero module ID for override");
3375         LE.write<uint32_t>(Overridden[I]);
3376       }
3377     }
3378   }
3379 
3380   void EmitData(raw_ostream& Out, IdentifierInfo* II,
3381                 IdentID ID, unsigned) {
3382     using namespace llvm::support;
3383     endian::Writer<little> LE(Out);
3384     MacroDirective *Macro = nullptr;
3385     if (!isInterestingIdentifier(II, Macro)) {
3386       LE.write<uint32_t>(ID << 1);
3387       return;
3388     }
3389 
3390     LE.write<uint32_t>((ID << 1) | 0x01);
3391     uint32_t Bits = (uint32_t)II->getObjCOrBuiltinID();
3392     assert((Bits & 0xffff) == Bits && "ObjCOrBuiltinID too big for ASTReader.");
3393     LE.write<uint16_t>(Bits);
3394     Bits = 0;
3395     bool HadMacroDefinition = hadMacroDefinition(II, Macro);
3396     Bits = (Bits << 1) | unsigned(HadMacroDefinition);
3397     Bits = (Bits << 1) | unsigned(IsModule);
3398     Bits = (Bits << 1) | unsigned(II->isExtensionToken());
3399     Bits = (Bits << 1) | unsigned(II->isPoisoned());
3400     Bits = (Bits << 1) | unsigned(II->hasRevertedTokenIDToIdentifier());
3401     Bits = (Bits << 1) | unsigned(II->isCPlusPlusOperatorKeyword());
3402     LE.write<uint16_t>(Bits);
3403 
3404     if (HadMacroDefinition) {
3405       LE.write<uint32_t>(Writer.getMacroDirectivesOffset(II));
3406       if (IsModule) {
3407         // Write the IDs of macros coming from different submodules.
3408         MacroState State;
3409         SmallVector<SubmoduleID, 16> Scratch;
3410         for (MacroDirective *MD = getFirstPublicSubmoduleMacro(Macro, State);
3411              MD; MD = getNextPublicSubmoduleMacro(MD, State)) {
3412           if (DefMacroDirective *DefMD = dyn_cast<DefMacroDirective>(MD)) {
3413             // FIXME: If this macro directive was created by #pragma pop_macros,
3414             // or if it was created implicitly by resolving conflicting macros,
3415             // it may be for a different submodule from the one in the MacroInfo
3416             // object. If so, we should write out its owning ModuleID.
3417             MacroID InfoID = Writer.getMacroID(DefMD->getInfo());
3418             assert(InfoID);
3419             LE.write<uint32_t>(InfoID << 1);
3420           } else {
3421             auto *UndefMD = cast<UndefMacroDirective>(MD);
3422             SubmoduleID Mod = UndefMD->isImported()
3423                                   ? UndefMD->getOwningModuleID()
3424                                   : getSubmoduleID(UndefMD);
3425             LE.write<uint32_t>((Mod << 1) | 1);
3426           }
3427           emitMacroOverrides(Out, getOverriddenSubmodules(MD, Scratch));
3428         }
3429         LE.write<uint32_t>(0xdeadbeef);
3430       }
3431     }
3432 
3433     // Emit the declaration IDs in reverse order, because the
3434     // IdentifierResolver provides the declarations as they would be
3435     // visible (e.g., the function "stat" would come before the struct
3436     // "stat"), but the ASTReader adds declarations to the end of the list
3437     // (so we need to see the struct "stat" before the function "stat").
3438     // Only emit declarations that aren't from a chained PCH, though.
3439     SmallVector<NamedDecl *, 16> Decls(IdResolver.begin(II), IdResolver.end());
3440     for (SmallVectorImpl<NamedDecl *>::reverse_iterator D = Decls.rbegin(),
3441                                                         DEnd = Decls.rend();
3442          D != DEnd; ++D)
3443       LE.write<uint32_t>(
3444           Writer.getDeclID(getDeclForLocalLookup(PP.getLangOpts(), *D)));
3445   }
3446 };
3447 } // end anonymous namespace
3448 
3449 /// \brief Write the identifier table into the AST file.
3450 ///
3451 /// The identifier table consists of a blob containing string data
3452 /// (the actual identifiers themselves) and a separate "offsets" index
3453 /// that maps identifier IDs to locations within the blob.
3454 void ASTWriter::WriteIdentifierTable(Preprocessor &PP,
3455                                      IdentifierResolver &IdResolver,
3456                                      bool IsModule) {
3457   using namespace llvm;
3458 
3459   // Create and write out the blob that contains the identifier
3460   // strings.
3461   {
3462     llvm::OnDiskChainedHashTableGenerator<ASTIdentifierTableTrait> Generator;
3463     ASTIdentifierTableTrait Trait(*this, PP, IdResolver, IsModule);
3464 
3465     // Look for any identifiers that were named while processing the
3466     // headers, but are otherwise not needed. We add these to the hash
3467     // table to enable checking of the predefines buffer in the case
3468     // where the user adds new macro definitions when building the AST
3469     // file.
3470     for (IdentifierTable::iterator ID = PP.getIdentifierTable().begin(),
3471                                 IDEnd = PP.getIdentifierTable().end();
3472          ID != IDEnd; ++ID)
3473       getIdentifierRef(ID->second);
3474 
3475     // Create the on-disk hash table representation. We only store offsets
3476     // for identifiers that appear here for the first time.
3477     IdentifierOffsets.resize(NextIdentID - FirstIdentID);
3478     for (llvm::DenseMap<const IdentifierInfo *, IdentID>::iterator
3479            ID = IdentifierIDs.begin(), IDEnd = IdentifierIDs.end();
3480          ID != IDEnd; ++ID) {
3481       assert(ID->first && "NULL identifier in identifier table");
3482       if (!Chain || !ID->first->isFromAST() ||
3483           ID->first->hasChangedSinceDeserialization())
3484         Generator.insert(const_cast<IdentifierInfo *>(ID->first), ID->second,
3485                          Trait);
3486     }
3487 
3488     // Create the on-disk hash table in a buffer.
3489     SmallString<4096> IdentifierTable;
3490     uint32_t BucketOffset;
3491     {
3492       using namespace llvm::support;
3493       ASTIdentifierTableTrait Trait(*this, PP, IdResolver, IsModule);
3494       llvm::raw_svector_ostream Out(IdentifierTable);
3495       // Make sure that no bucket is at offset 0
3496       endian::Writer<little>(Out).write<uint32_t>(0);
3497       BucketOffset = Generator.Emit(Out, Trait);
3498     }
3499 
3500     // Create a blob abbreviation
3501     BitCodeAbbrev *Abbrev = new BitCodeAbbrev();
3502     Abbrev->Add(BitCodeAbbrevOp(IDENTIFIER_TABLE));
3503     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
3504     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
3505     unsigned IDTableAbbrev = Stream.EmitAbbrev(Abbrev);
3506 
3507     // Write the identifier table
3508     RecordData Record;
3509     Record.push_back(IDENTIFIER_TABLE);
3510     Record.push_back(BucketOffset);
3511     Stream.EmitRecordWithBlob(IDTableAbbrev, Record, IdentifierTable.str());
3512   }
3513 
3514   // Write the offsets table for identifier IDs.
3515   BitCodeAbbrev *Abbrev = new BitCodeAbbrev();
3516   Abbrev->Add(BitCodeAbbrevOp(IDENTIFIER_OFFSET));
3517   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // # of identifiers
3518   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // first ID
3519   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
3520   unsigned IdentifierOffsetAbbrev = Stream.EmitAbbrev(Abbrev);
3521 
3522 #ifndef NDEBUG
3523   for (unsigned I = 0, N = IdentifierOffsets.size(); I != N; ++I)
3524     assert(IdentifierOffsets[I] && "Missing identifier offset?");
3525 #endif
3526 
3527   RecordData Record;
3528   Record.push_back(IDENTIFIER_OFFSET);
3529   Record.push_back(IdentifierOffsets.size());
3530   Record.push_back(FirstIdentID - NUM_PREDEF_IDENT_IDS);
3531   Stream.EmitRecordWithBlob(IdentifierOffsetAbbrev, Record,
3532                             data(IdentifierOffsets));
3533 }
3534 
3535 //===----------------------------------------------------------------------===//
3536 // DeclContext's Name Lookup Table Serialization
3537 //===----------------------------------------------------------------------===//
3538 
3539 namespace {
3540 // Trait used for the on-disk hash table used in the method pool.
3541 class ASTDeclContextNameLookupTrait {
3542   ASTWriter &Writer;
3543 
3544 public:
3545   typedef DeclarationName key_type;
3546   typedef key_type key_type_ref;
3547 
3548   typedef DeclContext::lookup_result data_type;
3549   typedef const data_type& data_type_ref;
3550 
3551   typedef unsigned hash_value_type;
3552   typedef unsigned offset_type;
3553 
3554   explicit ASTDeclContextNameLookupTrait(ASTWriter &Writer) : Writer(Writer) { }
3555 
3556   hash_value_type ComputeHash(DeclarationName Name) {
3557     llvm::FoldingSetNodeID ID;
3558     ID.AddInteger(Name.getNameKind());
3559 
3560     switch (Name.getNameKind()) {
3561     case DeclarationName::Identifier:
3562       ID.AddString(Name.getAsIdentifierInfo()->getName());
3563       break;
3564     case DeclarationName::ObjCZeroArgSelector:
3565     case DeclarationName::ObjCOneArgSelector:
3566     case DeclarationName::ObjCMultiArgSelector:
3567       ID.AddInteger(serialization::ComputeHash(Name.getObjCSelector()));
3568       break;
3569     case DeclarationName::CXXConstructorName:
3570     case DeclarationName::CXXDestructorName:
3571     case DeclarationName::CXXConversionFunctionName:
3572       break;
3573     case DeclarationName::CXXOperatorName:
3574       ID.AddInteger(Name.getCXXOverloadedOperator());
3575       break;
3576     case DeclarationName::CXXLiteralOperatorName:
3577       ID.AddString(Name.getCXXLiteralIdentifier()->getName());
3578     case DeclarationName::CXXUsingDirective:
3579       break;
3580     }
3581 
3582     return ID.ComputeHash();
3583   }
3584 
3585   std::pair<unsigned,unsigned>
3586     EmitKeyDataLength(raw_ostream& Out, DeclarationName Name,
3587                       data_type_ref Lookup) {
3588     using namespace llvm::support;
3589     endian::Writer<little> LE(Out);
3590     unsigned KeyLen = 1;
3591     switch (Name.getNameKind()) {
3592     case DeclarationName::Identifier:
3593     case DeclarationName::ObjCZeroArgSelector:
3594     case DeclarationName::ObjCOneArgSelector:
3595     case DeclarationName::ObjCMultiArgSelector:
3596     case DeclarationName::CXXLiteralOperatorName:
3597       KeyLen += 4;
3598       break;
3599     case DeclarationName::CXXOperatorName:
3600       KeyLen += 1;
3601       break;
3602     case DeclarationName::CXXConstructorName:
3603     case DeclarationName::CXXDestructorName:
3604     case DeclarationName::CXXConversionFunctionName:
3605     case DeclarationName::CXXUsingDirective:
3606       break;
3607     }
3608     LE.write<uint16_t>(KeyLen);
3609 
3610     // 2 bytes for num of decls and 4 for each DeclID.
3611     unsigned DataLen = 2 + 4 * Lookup.size();
3612     LE.write<uint16_t>(DataLen);
3613 
3614     return std::make_pair(KeyLen, DataLen);
3615   }
3616 
3617   void EmitKey(raw_ostream& Out, DeclarationName Name, unsigned) {
3618     using namespace llvm::support;
3619     endian::Writer<little> LE(Out);
3620     LE.write<uint8_t>(Name.getNameKind());
3621     switch (Name.getNameKind()) {
3622     case DeclarationName::Identifier:
3623       LE.write<uint32_t>(Writer.getIdentifierRef(Name.getAsIdentifierInfo()));
3624       return;
3625     case DeclarationName::ObjCZeroArgSelector:
3626     case DeclarationName::ObjCOneArgSelector:
3627     case DeclarationName::ObjCMultiArgSelector:
3628       LE.write<uint32_t>(Writer.getSelectorRef(Name.getObjCSelector()));
3629       return;
3630     case DeclarationName::CXXOperatorName:
3631       assert(Name.getCXXOverloadedOperator() < NUM_OVERLOADED_OPERATORS &&
3632              "Invalid operator?");
3633       LE.write<uint8_t>(Name.getCXXOverloadedOperator());
3634       return;
3635     case DeclarationName::CXXLiteralOperatorName:
3636       LE.write<uint32_t>(Writer.getIdentifierRef(Name.getCXXLiteralIdentifier()));
3637       return;
3638     case DeclarationName::CXXConstructorName:
3639     case DeclarationName::CXXDestructorName:
3640     case DeclarationName::CXXConversionFunctionName:
3641     case DeclarationName::CXXUsingDirective:
3642       return;
3643     }
3644 
3645     llvm_unreachable("Invalid name kind?");
3646   }
3647 
3648   void EmitData(raw_ostream& Out, key_type_ref,
3649                 data_type Lookup, unsigned DataLen) {
3650     using namespace llvm::support;
3651     endian::Writer<little> LE(Out);
3652     uint64_t Start = Out.tell(); (void)Start;
3653     LE.write<uint16_t>(Lookup.size());
3654     for (DeclContext::lookup_iterator I = Lookup.begin(), E = Lookup.end();
3655          I != E; ++I)
3656       LE.write<uint32_t>(
3657           Writer.GetDeclRef(getDeclForLocalLookup(Writer.getLangOpts(), *I)));
3658 
3659     assert(Out.tell() - Start == DataLen && "Data length is wrong");
3660   }
3661 };
3662 } // end anonymous namespace
3663 
3664 template<typename Visitor>
3665 static void visitLocalLookupResults(const DeclContext *ConstDC,
3666                                     bool NeedToReconcileExternalVisibleStorage,
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 (Lookup.second.hasExternalDecls() ||
3675         NeedToReconcileExternalVisibleStorage) {
3676       // We don't know for sure what declarations are found by this name,
3677       // because the external source might have a different set from the set
3678       // that are in the lookup map, and we can't update it now without
3679       // risking invalidating our lookup iterator. So add it to a queue to
3680       // deal with later.
3681       ExternalNames.push_back(Lookup.first);
3682       continue;
3683     }
3684 
3685     AddLookupResult(Lookup.first, Lookup.second.getLookupResult());
3686   }
3687 
3688   // Add the names we needed to defer. Note, this shouldn't add any new decls
3689   // to the list we need to serialize: any new declarations we find here should
3690   // be imported from an external source.
3691   // FIXME: What if the external source isn't an ASTReader?
3692   for (const auto &Name : ExternalNames)
3693     AddLookupResult(Name, DC->lookup(Name));
3694 }
3695 
3696 void ASTWriter::AddUpdatedDeclContext(const DeclContext *DC) {
3697   if (UpdatedDeclContexts.insert(DC).second && WritingAST) {
3698     // Ensure we emit all the visible declarations.
3699     visitLocalLookupResults(DC, DC->NeedToReconcileExternalVisibleStorage,
3700                             [&](DeclarationName Name,
3701                                 DeclContext::lookup_const_result Result) {
3702       for (auto *Decl : Result)
3703         GetDeclRef(getDeclForLocalLookup(getLangOpts(), Decl));
3704     });
3705   }
3706 }
3707 
3708 uint32_t
3709 ASTWriter::GenerateNameLookupTable(const DeclContext *DC,
3710                                    llvm::SmallVectorImpl<char> &LookupTable) {
3711   assert(!DC->LookupPtr.getInt() && "must call buildLookups first");
3712 
3713   llvm::OnDiskChainedHashTableGenerator<ASTDeclContextNameLookupTrait>
3714       Generator;
3715   ASTDeclContextNameLookupTrait Trait(*this);
3716 
3717   // Create the on-disk hash table representation.
3718   DeclarationName ConstructorName;
3719   DeclarationName ConversionName;
3720   SmallVector<NamedDecl *, 8> ConstructorDecls;
3721   SmallVector<NamedDecl *, 4> ConversionDecls;
3722 
3723   visitLocalLookupResults(DC, DC->NeedToReconcileExternalVisibleStorage,
3724                           [&](DeclarationName Name,
3725                               DeclContext::lookup_result Result) {
3726     if (Result.empty())
3727       return;
3728 
3729     // Different DeclarationName values of certain kinds are mapped to
3730     // identical serialized keys, because we don't want to use type
3731     // identifiers in the keys (since type ids are local to the module).
3732     switch (Name.getNameKind()) {
3733     case DeclarationName::CXXConstructorName:
3734       // There may be different CXXConstructorName DeclarationName values
3735       // in a DeclContext because a UsingDecl that inherits constructors
3736       // has the DeclarationName of the inherited constructors.
3737       if (!ConstructorName)
3738         ConstructorName = Name;
3739       ConstructorDecls.append(Result.begin(), Result.end());
3740       return;
3741 
3742     case DeclarationName::CXXConversionFunctionName:
3743       if (!ConversionName)
3744         ConversionName = Name;
3745       ConversionDecls.append(Result.begin(), Result.end());
3746       return;
3747 
3748     default:
3749       break;
3750     }
3751 
3752     Generator.insert(Name, Result, Trait);
3753   });
3754 
3755   // Add the constructors.
3756   if (!ConstructorDecls.empty()) {
3757     Generator.insert(ConstructorName,
3758                      DeclContext::lookup_result(ConstructorDecls.begin(),
3759                                                 ConstructorDecls.end()),
3760                      Trait);
3761   }
3762 
3763   // Add the conversion functions.
3764   if (!ConversionDecls.empty()) {
3765     Generator.insert(ConversionName,
3766                      DeclContext::lookup_result(ConversionDecls.begin(),
3767                                                 ConversionDecls.end()),
3768                      Trait);
3769   }
3770 
3771   // Create the on-disk hash table in a buffer.
3772   llvm::raw_svector_ostream Out(LookupTable);
3773   // Make sure that no bucket is at offset 0
3774   using namespace llvm::support;
3775   endian::Writer<little>(Out).write<uint32_t>(0);
3776   return Generator.Emit(Out, Trait);
3777 }
3778 
3779 /// \brief Write the block containing all of the declaration IDs
3780 /// visible from the given DeclContext.
3781 ///
3782 /// \returns the offset of the DECL_CONTEXT_VISIBLE block within the
3783 /// bitstream, or 0 if no block was written.
3784 uint64_t ASTWriter::WriteDeclContextVisibleBlock(ASTContext &Context,
3785                                                  DeclContext *DC) {
3786   if (DC->getPrimaryContext() != DC)
3787     return 0;
3788 
3789   // Since there is no name lookup into functions or methods, don't bother to
3790   // build a visible-declarations table for these entities.
3791   if (DC->isFunctionOrMethod())
3792     return 0;
3793 
3794   // If not in C++, we perform name lookup for the translation unit via the
3795   // IdentifierInfo chains, don't bother to build a visible-declarations table.
3796   if (DC->isTranslationUnit() && !Context.getLangOpts().CPlusPlus)
3797     return 0;
3798 
3799   // Serialize the contents of the mapping used for lookup. Note that,
3800   // although we have two very different code paths, the serialized
3801   // representation is the same for both cases: a declaration name,
3802   // followed by a size, followed by references to the visible
3803   // declarations that have that name.
3804   uint64_t Offset = Stream.GetCurrentBitNo();
3805   StoredDeclsMap *Map = DC->buildLookup();
3806   if (!Map || Map->empty())
3807     return 0;
3808 
3809   // Create the on-disk hash table in a buffer.
3810   SmallString<4096> LookupTable;
3811   uint32_t BucketOffset = GenerateNameLookupTable(DC, LookupTable);
3812 
3813   // Write the lookup table
3814   RecordData Record;
3815   Record.push_back(DECL_CONTEXT_VISIBLE);
3816   Record.push_back(BucketOffset);
3817   Stream.EmitRecordWithBlob(DeclContextVisibleLookupAbbrev, Record,
3818                             LookupTable.str());
3819   ++NumVisibleDeclContexts;
3820   return Offset;
3821 }
3822 
3823 /// \brief Write an UPDATE_VISIBLE block for the given context.
3824 ///
3825 /// UPDATE_VISIBLE blocks contain the declarations that are added to an existing
3826 /// DeclContext in a dependent AST file. As such, they only exist for the TU
3827 /// (in C++), for namespaces, and for classes with forward-declared unscoped
3828 /// enumeration members (in C++11).
3829 void ASTWriter::WriteDeclContextVisibleUpdate(const DeclContext *DC) {
3830   StoredDeclsMap *Map = DC->getLookupPtr();
3831   if (!Map || Map->empty())
3832     return;
3833 
3834   // Create the on-disk hash table in a buffer.
3835   SmallString<4096> LookupTable;
3836   uint32_t BucketOffset = GenerateNameLookupTable(DC, LookupTable);
3837 
3838   // Write the lookup table
3839   RecordData Record;
3840   Record.push_back(UPDATE_VISIBLE);
3841   Record.push_back(getDeclID(cast<Decl>(DC)));
3842   Record.push_back(BucketOffset);
3843   Stream.EmitRecordWithBlob(UpdateVisibleAbbrev, Record, LookupTable.str());
3844 }
3845 
3846 /// \brief Write an FP_PRAGMA_OPTIONS block for the given FPOptions.
3847 void ASTWriter::WriteFPPragmaOptions(const FPOptions &Opts) {
3848   RecordData Record;
3849   Record.push_back(Opts.fp_contract);
3850   Stream.EmitRecord(FP_PRAGMA_OPTIONS, Record);
3851 }
3852 
3853 /// \brief Write an OPENCL_EXTENSIONS block for the given OpenCLOptions.
3854 void ASTWriter::WriteOpenCLExtensions(Sema &SemaRef) {
3855   if (!SemaRef.Context.getLangOpts().OpenCL)
3856     return;
3857 
3858   const OpenCLOptions &Opts = SemaRef.getOpenCLOptions();
3859   RecordData Record;
3860 #define OPENCLEXT(nm)  Record.push_back(Opts.nm);
3861 #include "clang/Basic/OpenCLExtensions.def"
3862   Stream.EmitRecord(OPENCL_EXTENSIONS, Record);
3863 }
3864 
3865 void ASTWriter::WriteRedeclarations() {
3866   RecordData LocalRedeclChains;
3867   SmallVector<serialization::LocalRedeclarationsInfo, 2> LocalRedeclsMap;
3868 
3869   for (unsigned I = 0, N = Redeclarations.size(); I != N; ++I) {
3870     Decl *First = Redeclarations[I];
3871     assert(First->isFirstDecl() && "Not the first declaration?");
3872 
3873     Decl *MostRecent = First->getMostRecentDecl();
3874 
3875     // If we only have a single declaration, there is no point in storing
3876     // a redeclaration chain.
3877     if (First == MostRecent)
3878       continue;
3879 
3880     unsigned Offset = LocalRedeclChains.size();
3881     unsigned Size = 0;
3882     LocalRedeclChains.push_back(0); // Placeholder for the size.
3883 
3884     // Collect the set of local redeclarations of this declaration.
3885     for (Decl *Prev = MostRecent; Prev != First;
3886          Prev = Prev->getPreviousDecl()) {
3887       if (!Prev->isFromASTFile()) {
3888         AddDeclRef(Prev, LocalRedeclChains);
3889         ++Size;
3890       }
3891     }
3892 
3893     if (!First->isFromASTFile() && Chain) {
3894       Decl *FirstFromAST = MostRecent;
3895       for (Decl *Prev = MostRecent; Prev; Prev = Prev->getPreviousDecl()) {
3896         if (Prev->isFromASTFile())
3897           FirstFromAST = Prev;
3898       }
3899 
3900       // FIXME: Do we need to do this for the first declaration from each
3901       // redeclaration chain that was merged into this one?
3902       Chain->MergedDecls[FirstFromAST].push_back(getDeclID(First));
3903     }
3904 
3905     LocalRedeclChains[Offset] = Size;
3906 
3907     // Reverse the set of local redeclarations, so that we store them in
3908     // order (since we found them in reverse order).
3909     std::reverse(LocalRedeclChains.end() - Size, LocalRedeclChains.end());
3910 
3911     // Add the mapping from the first ID from the AST to the set of local
3912     // declarations.
3913     LocalRedeclarationsInfo Info = { getDeclID(First), Offset };
3914     LocalRedeclsMap.push_back(Info);
3915 
3916     assert(N == Redeclarations.size() &&
3917            "Deserialized a declaration we shouldn't have");
3918   }
3919 
3920   if (LocalRedeclChains.empty())
3921     return;
3922 
3923   // Sort the local redeclarations map by the first declaration ID,
3924   // since the reader will be performing binary searches on this information.
3925   llvm::array_pod_sort(LocalRedeclsMap.begin(), LocalRedeclsMap.end());
3926 
3927   // Emit the local redeclarations map.
3928   using namespace llvm;
3929   llvm::BitCodeAbbrev *Abbrev = new BitCodeAbbrev();
3930   Abbrev->Add(BitCodeAbbrevOp(LOCAL_REDECLARATIONS_MAP));
3931   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // # of entries
3932   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
3933   unsigned AbbrevID = Stream.EmitAbbrev(Abbrev);
3934 
3935   RecordData Record;
3936   Record.push_back(LOCAL_REDECLARATIONS_MAP);
3937   Record.push_back(LocalRedeclsMap.size());
3938   Stream.EmitRecordWithBlob(AbbrevID, Record,
3939     reinterpret_cast<char*>(LocalRedeclsMap.data()),
3940     LocalRedeclsMap.size() * sizeof(LocalRedeclarationsInfo));
3941 
3942   // Emit the redeclaration chains.
3943   Stream.EmitRecord(LOCAL_REDECLARATIONS, LocalRedeclChains);
3944 }
3945 
3946 void ASTWriter::WriteObjCCategories() {
3947   SmallVector<ObjCCategoriesInfo, 2> CategoriesMap;
3948   RecordData Categories;
3949 
3950   for (unsigned I = 0, N = ObjCClassesWithCategories.size(); I != N; ++I) {
3951     unsigned Size = 0;
3952     unsigned StartIndex = Categories.size();
3953 
3954     ObjCInterfaceDecl *Class = ObjCClassesWithCategories[I];
3955 
3956     // Allocate space for the size.
3957     Categories.push_back(0);
3958 
3959     // Add the categories.
3960     for (ObjCInterfaceDecl::known_categories_iterator
3961            Cat = Class->known_categories_begin(),
3962            CatEnd = Class->known_categories_end();
3963          Cat != CatEnd; ++Cat, ++Size) {
3964       assert(getDeclID(*Cat) != 0 && "Bogus category");
3965       AddDeclRef(*Cat, Categories);
3966     }
3967 
3968     // Update the size.
3969     Categories[StartIndex] = Size;
3970 
3971     // Record this interface -> category map.
3972     ObjCCategoriesInfo CatInfo = { getDeclID(Class), StartIndex };
3973     CategoriesMap.push_back(CatInfo);
3974   }
3975 
3976   // Sort the categories map by the definition ID, since the reader will be
3977   // performing binary searches on this information.
3978   llvm::array_pod_sort(CategoriesMap.begin(), CategoriesMap.end());
3979 
3980   // Emit the categories map.
3981   using namespace llvm;
3982   llvm::BitCodeAbbrev *Abbrev = new BitCodeAbbrev();
3983   Abbrev->Add(BitCodeAbbrevOp(OBJC_CATEGORIES_MAP));
3984   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // # of entries
3985   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
3986   unsigned AbbrevID = Stream.EmitAbbrev(Abbrev);
3987 
3988   RecordData Record;
3989   Record.push_back(OBJC_CATEGORIES_MAP);
3990   Record.push_back(CategoriesMap.size());
3991   Stream.EmitRecordWithBlob(AbbrevID, Record,
3992                             reinterpret_cast<char*>(CategoriesMap.data()),
3993                             CategoriesMap.size() * sizeof(ObjCCategoriesInfo));
3994 
3995   // Emit the category lists.
3996   Stream.EmitRecord(OBJC_CATEGORIES, Categories);
3997 }
3998 
3999 void ASTWriter::WriteMergedDecls() {
4000   if (!Chain || Chain->MergedDecls.empty())
4001     return;
4002 
4003   RecordData Record;
4004   for (ASTReader::MergedDeclsMap::iterator I = Chain->MergedDecls.begin(),
4005                                         IEnd = Chain->MergedDecls.end();
4006        I != IEnd; ++I) {
4007     DeclID CanonID = I->first->isFromASTFile()? I->first->getGlobalID()
4008                                               : GetDeclRef(I->first);
4009     assert(CanonID && "Merged declaration not known?");
4010 
4011     Record.push_back(CanonID);
4012     Record.push_back(I->second.size());
4013     Record.append(I->second.begin(), I->second.end());
4014   }
4015   Stream.EmitRecord(MERGED_DECLARATIONS, Record);
4016 }
4017 
4018 void ASTWriter::WriteLateParsedTemplates(Sema &SemaRef) {
4019   Sema::LateParsedTemplateMapT &LPTMap = SemaRef.LateParsedTemplateMap;
4020 
4021   if (LPTMap.empty())
4022     return;
4023 
4024   RecordData Record;
4025   for (Sema::LateParsedTemplateMapT::iterator It = LPTMap.begin(),
4026                                               ItEnd = LPTMap.end();
4027        It != ItEnd; ++It) {
4028     LateParsedTemplate *LPT = It->second;
4029     AddDeclRef(It->first, Record);
4030     AddDeclRef(LPT->D, Record);
4031     Record.push_back(LPT->Toks.size());
4032 
4033     for (CachedTokens::iterator TokIt = LPT->Toks.begin(),
4034                                 TokEnd = LPT->Toks.end();
4035          TokIt != TokEnd; ++TokIt) {
4036       AddToken(*TokIt, Record);
4037     }
4038   }
4039   Stream.EmitRecord(LATE_PARSED_TEMPLATE, Record);
4040 }
4041 
4042 /// \brief Write the state of 'pragma clang optimize' at the end of the module.
4043 void ASTWriter::WriteOptimizePragmaOptions(Sema &SemaRef) {
4044   RecordData Record;
4045   SourceLocation PragmaLoc = SemaRef.getOptimizeOffPragmaLocation();
4046   AddSourceLocation(PragmaLoc, Record);
4047   Stream.EmitRecord(OPTIMIZE_PRAGMA_OPTIONS, Record);
4048 }
4049 
4050 //===----------------------------------------------------------------------===//
4051 // General Serialization Routines
4052 //===----------------------------------------------------------------------===//
4053 
4054 /// \brief Write a record containing the given attributes.
4055 void ASTWriter::WriteAttributes(ArrayRef<const Attr*> Attrs,
4056                                 RecordDataImpl &Record) {
4057   Record.push_back(Attrs.size());
4058   for (ArrayRef<const Attr *>::iterator i = Attrs.begin(),
4059                                         e = Attrs.end(); i != e; ++i){
4060     const Attr *A = *i;
4061     Record.push_back(A->getKind()); // FIXME: stable encoding, target attrs
4062     AddSourceRange(A->getRange(), Record);
4063 
4064 #include "clang/Serialization/AttrPCHWrite.inc"
4065 
4066   }
4067 }
4068 
4069 void ASTWriter::AddToken(const Token &Tok, RecordDataImpl &Record) {
4070   AddSourceLocation(Tok.getLocation(), Record);
4071   Record.push_back(Tok.getLength());
4072 
4073   // FIXME: When reading literal tokens, reconstruct the literal pointer
4074   // if it is needed.
4075   AddIdentifierRef(Tok.getIdentifierInfo(), Record);
4076   // FIXME: Should translate token kind to a stable encoding.
4077   Record.push_back(Tok.getKind());
4078   // FIXME: Should translate token flags to a stable encoding.
4079   Record.push_back(Tok.getFlags());
4080 }
4081 
4082 void ASTWriter::AddString(StringRef Str, RecordDataImpl &Record) {
4083   Record.push_back(Str.size());
4084   Record.insert(Record.end(), Str.begin(), Str.end());
4085 }
4086 
4087 bool ASTWriter::PreparePathForOutput(SmallVectorImpl<char> &Path) {
4088   assert(Context && "should have context when outputting path");
4089 
4090   bool Changed =
4091       cleanPathForOutput(Context->getSourceManager().getFileManager(), Path);
4092 
4093   // Remove a prefix to make the path relative, if relevant.
4094   const char *PathBegin = Path.data();
4095   const char *PathPtr =
4096       adjustFilenameForRelocatableAST(PathBegin, BaseDirectory);
4097   if (PathPtr != PathBegin) {
4098     Path.erase(Path.begin(), Path.begin() + (PathPtr - PathBegin));
4099     Changed = true;
4100   }
4101 
4102   return Changed;
4103 }
4104 
4105 void ASTWriter::AddPath(StringRef Path, RecordDataImpl &Record) {
4106   SmallString<128> FilePath(Path);
4107   PreparePathForOutput(FilePath);
4108   AddString(FilePath, Record);
4109 }
4110 
4111 void ASTWriter::EmitRecordWithPath(unsigned Abbrev, RecordDataImpl &Record,
4112                                    StringRef Path) {
4113   SmallString<128> FilePath(Path);
4114   PreparePathForOutput(FilePath);
4115   Stream.EmitRecordWithBlob(Abbrev, Record, FilePath);
4116 }
4117 
4118 void ASTWriter::AddVersionTuple(const VersionTuple &Version,
4119                                 RecordDataImpl &Record) {
4120   Record.push_back(Version.getMajor());
4121   if (Optional<unsigned> Minor = Version.getMinor())
4122     Record.push_back(*Minor + 1);
4123   else
4124     Record.push_back(0);
4125   if (Optional<unsigned> Subminor = Version.getSubminor())
4126     Record.push_back(*Subminor + 1);
4127   else
4128     Record.push_back(0);
4129 }
4130 
4131 /// \brief Note that the identifier II occurs at the given offset
4132 /// within the identifier table.
4133 void ASTWriter::SetIdentifierOffset(const IdentifierInfo *II, uint32_t Offset) {
4134   IdentID ID = IdentifierIDs[II];
4135   // Only store offsets new to this AST file. Other identifier names are looked
4136   // up earlier in the chain and thus don't need an offset.
4137   if (ID >= FirstIdentID)
4138     IdentifierOffsets[ID - FirstIdentID] = Offset;
4139 }
4140 
4141 /// \brief Note that the selector Sel occurs at the given offset
4142 /// within the method pool/selector table.
4143 void ASTWriter::SetSelectorOffset(Selector Sel, uint32_t Offset) {
4144   unsigned ID = SelectorIDs[Sel];
4145   assert(ID && "Unknown selector");
4146   // Don't record offsets for selectors that are also available in a different
4147   // file.
4148   if (ID < FirstSelectorID)
4149     return;
4150   SelectorOffsets[ID - FirstSelectorID] = Offset;
4151 }
4152 
4153 ASTWriter::ASTWriter(llvm::BitstreamWriter &Stream)
4154     : Stream(Stream), Context(nullptr), PP(nullptr), Chain(nullptr),
4155       WritingModule(nullptr), WritingAST(false),
4156       DoneWritingDeclsAndTypes(false), ASTHasCompilerErrors(false),
4157       FirstDeclID(NUM_PREDEF_DECL_IDS), NextDeclID(FirstDeclID),
4158       FirstTypeID(NUM_PREDEF_TYPE_IDS), NextTypeID(FirstTypeID),
4159       FirstIdentID(NUM_PREDEF_IDENT_IDS), NextIdentID(FirstIdentID),
4160       FirstMacroID(NUM_PREDEF_MACRO_IDS), NextMacroID(FirstMacroID),
4161       FirstSubmoduleID(NUM_PREDEF_SUBMODULE_IDS),
4162       NextSubmoduleID(FirstSubmoduleID),
4163       FirstSelectorID(NUM_PREDEF_SELECTOR_IDS), NextSelectorID(FirstSelectorID),
4164       CollectedStmts(&StmtsToEmit), NumStatements(0), NumMacros(0),
4165       NumLexicalDeclContexts(0), NumVisibleDeclContexts(0),
4166       NextCXXBaseSpecifiersID(1), TypeExtQualAbbrev(0),
4167       TypeFunctionProtoAbbrev(0), DeclParmVarAbbrev(0),
4168       DeclContextLexicalAbbrev(0), DeclContextVisibleLookupAbbrev(0),
4169       UpdateVisibleAbbrev(0), DeclRecordAbbrev(0), DeclTypedefAbbrev(0),
4170       DeclVarAbbrev(0), DeclFieldAbbrev(0), DeclEnumAbbrev(0),
4171       DeclObjCIvarAbbrev(0), DeclCXXMethodAbbrev(0), DeclRefExprAbbrev(0),
4172       CharacterLiteralAbbrev(0), IntegerLiteralAbbrev(0),
4173       ExprImplicitCastAbbrev(0) {}
4174 
4175 ASTWriter::~ASTWriter() {
4176   llvm::DeleteContainerSeconds(FileDeclIDs);
4177 }
4178 
4179 const LangOptions &ASTWriter::getLangOpts() const {
4180   assert(WritingAST && "can't determine lang opts when not writing AST");
4181   return Context->getLangOpts();
4182 }
4183 
4184 void ASTWriter::WriteAST(Sema &SemaRef,
4185                          const std::string &OutputFile,
4186                          Module *WritingModule, StringRef isysroot,
4187                          bool hasErrors) {
4188   WritingAST = true;
4189 
4190   ASTHasCompilerErrors = hasErrors;
4191 
4192   // Emit the file header.
4193   Stream.Emit((unsigned)'C', 8);
4194   Stream.Emit((unsigned)'P', 8);
4195   Stream.Emit((unsigned)'C', 8);
4196   Stream.Emit((unsigned)'H', 8);
4197 
4198   WriteBlockInfoBlock();
4199 
4200   Context = &SemaRef.Context;
4201   PP = &SemaRef.PP;
4202   this->WritingModule = WritingModule;
4203   WriteASTCore(SemaRef, isysroot, OutputFile, WritingModule);
4204   Context = nullptr;
4205   PP = nullptr;
4206   this->WritingModule = nullptr;
4207   this->BaseDirectory.clear();
4208 
4209   WritingAST = false;
4210 }
4211 
4212 template<typename Vector>
4213 static void AddLazyVectorDecls(ASTWriter &Writer, Vector &Vec,
4214                                ASTWriter::RecordData &Record) {
4215   for (typename Vector::iterator I = Vec.begin(nullptr, true), E = Vec.end();
4216        I != E; ++I) {
4217     Writer.AddDeclRef(*I, Record);
4218   }
4219 }
4220 
4221 void ASTWriter::WriteASTCore(Sema &SemaRef,
4222                              StringRef isysroot,
4223                              const std::string &OutputFile,
4224                              Module *WritingModule) {
4225   using namespace llvm;
4226 
4227   bool isModule = WritingModule != nullptr;
4228 
4229   // Make sure that the AST reader knows to finalize itself.
4230   if (Chain)
4231     Chain->finalizeForWriting();
4232 
4233   ASTContext &Context = SemaRef.Context;
4234   Preprocessor &PP = SemaRef.PP;
4235 
4236   // Set up predefined declaration IDs.
4237   DeclIDs[Context.getTranslationUnitDecl()] = PREDEF_DECL_TRANSLATION_UNIT_ID;
4238   if (Context.ObjCIdDecl)
4239     DeclIDs[Context.ObjCIdDecl] = PREDEF_DECL_OBJC_ID_ID;
4240   if (Context.ObjCSelDecl)
4241     DeclIDs[Context.ObjCSelDecl] = PREDEF_DECL_OBJC_SEL_ID;
4242   if (Context.ObjCClassDecl)
4243     DeclIDs[Context.ObjCClassDecl] = PREDEF_DECL_OBJC_CLASS_ID;
4244   if (Context.ObjCProtocolClassDecl)
4245     DeclIDs[Context.ObjCProtocolClassDecl] = PREDEF_DECL_OBJC_PROTOCOL_ID;
4246   if (Context.Int128Decl)
4247     DeclIDs[Context.Int128Decl] = PREDEF_DECL_INT_128_ID;
4248   if (Context.UInt128Decl)
4249     DeclIDs[Context.UInt128Decl] = PREDEF_DECL_UNSIGNED_INT_128_ID;
4250   if (Context.ObjCInstanceTypeDecl)
4251     DeclIDs[Context.ObjCInstanceTypeDecl] = PREDEF_DECL_OBJC_INSTANCETYPE_ID;
4252   if (Context.BuiltinVaListDecl)
4253     DeclIDs[Context.getBuiltinVaListDecl()] = PREDEF_DECL_BUILTIN_VA_LIST_ID;
4254 
4255   if (!Chain) {
4256     // Make sure that we emit IdentifierInfos (and any attached
4257     // declarations) for builtins. We don't need to do this when we're
4258     // emitting chained PCH files, because all of the builtins will be
4259     // in the original PCH file.
4260     // FIXME: Modules won't like this at all.
4261     IdentifierTable &Table = PP.getIdentifierTable();
4262     SmallVector<const char *, 32> BuiltinNames;
4263     if (!Context.getLangOpts().NoBuiltin) {
4264       Context.BuiltinInfo.GetBuiltinNames(BuiltinNames);
4265     }
4266     for (unsigned I = 0, N = BuiltinNames.size(); I != N; ++I)
4267       getIdentifierRef(&Table.get(BuiltinNames[I]));
4268   }
4269 
4270   // If there are any out-of-date identifiers, bring them up to date.
4271   if (ExternalPreprocessorSource *ExtSource = PP.getExternalSource()) {
4272     // Find out-of-date identifiers.
4273     SmallVector<IdentifierInfo *, 4> OutOfDate;
4274     for (IdentifierTable::iterator ID = PP.getIdentifierTable().begin(),
4275                                 IDEnd = PP.getIdentifierTable().end();
4276          ID != IDEnd; ++ID) {
4277       if (ID->second->isOutOfDate())
4278         OutOfDate.push_back(ID->second);
4279     }
4280 
4281     // Update the out-of-date identifiers.
4282     for (unsigned I = 0, N = OutOfDate.size(); I != N; ++I) {
4283       ExtSource->updateOutOfDateIdentifier(*OutOfDate[I]);
4284     }
4285   }
4286 
4287   // If we saw any DeclContext updates before we started writing the AST file,
4288   // make sure all visible decls in those DeclContexts are written out.
4289   if (!UpdatedDeclContexts.empty()) {
4290     auto OldUpdatedDeclContexts = std::move(UpdatedDeclContexts);
4291     UpdatedDeclContexts.clear();
4292     for (auto *DC : OldUpdatedDeclContexts)
4293       AddUpdatedDeclContext(DC);
4294   }
4295 
4296   // Build a record containing all of the tentative definitions in this file, in
4297   // TentativeDefinitions order.  Generally, this record will be empty for
4298   // headers.
4299   RecordData TentativeDefinitions;
4300   AddLazyVectorDecls(*this, SemaRef.TentativeDefinitions, TentativeDefinitions);
4301 
4302   // Build a record containing all of the file scoped decls in this file.
4303   RecordData UnusedFileScopedDecls;
4304   if (!isModule)
4305     AddLazyVectorDecls(*this, SemaRef.UnusedFileScopedDecls,
4306                        UnusedFileScopedDecls);
4307 
4308   // Build a record containing all of the delegating constructors we still need
4309   // to resolve.
4310   RecordData DelegatingCtorDecls;
4311   if (!isModule)
4312     AddLazyVectorDecls(*this, SemaRef.DelegatingCtorDecls, DelegatingCtorDecls);
4313 
4314   // Write the set of weak, undeclared identifiers. We always write the
4315   // entire table, since later PCH files in a PCH chain are only interested in
4316   // the results at the end of the chain.
4317   RecordData WeakUndeclaredIdentifiers;
4318   if (!SemaRef.WeakUndeclaredIdentifiers.empty()) {
4319     for (llvm::DenseMap<IdentifierInfo*,WeakInfo>::iterator
4320          I = SemaRef.WeakUndeclaredIdentifiers.begin(),
4321          E = SemaRef.WeakUndeclaredIdentifiers.end(); I != E; ++I) {
4322       AddIdentifierRef(I->first, WeakUndeclaredIdentifiers);
4323       AddIdentifierRef(I->second.getAlias(), WeakUndeclaredIdentifiers);
4324       AddSourceLocation(I->second.getLocation(), WeakUndeclaredIdentifiers);
4325       WeakUndeclaredIdentifiers.push_back(I->second.getUsed());
4326     }
4327   }
4328 
4329   // Build a record containing all of the locally-scoped extern "C"
4330   // declarations in this header file. Generally, this record will be
4331   // empty.
4332   RecordData LocallyScopedExternCDecls;
4333   // FIXME: This is filling in the AST file in densemap order which is
4334   // nondeterminstic!
4335   for (llvm::DenseMap<DeclarationName, NamedDecl *>::iterator
4336          TD = SemaRef.LocallyScopedExternCDecls.begin(),
4337          TDEnd = SemaRef.LocallyScopedExternCDecls.end();
4338        TD != TDEnd; ++TD) {
4339     if (!TD->second->isFromASTFile())
4340       AddDeclRef(TD->second, LocallyScopedExternCDecls);
4341   }
4342 
4343   // Build a record containing all of the ext_vector declarations.
4344   RecordData ExtVectorDecls;
4345   AddLazyVectorDecls(*this, SemaRef.ExtVectorDecls, ExtVectorDecls);
4346 
4347   // Build a record containing all of the VTable uses information.
4348   RecordData VTableUses;
4349   if (!SemaRef.VTableUses.empty()) {
4350     for (unsigned I = 0, N = SemaRef.VTableUses.size(); I != N; ++I) {
4351       AddDeclRef(SemaRef.VTableUses[I].first, VTableUses);
4352       AddSourceLocation(SemaRef.VTableUses[I].second, VTableUses);
4353       VTableUses.push_back(SemaRef.VTablesUsed[SemaRef.VTableUses[I].first]);
4354     }
4355   }
4356 
4357   // Build a record containing all of the UnusedLocalTypedefNameCandidates.
4358   RecordData UnusedLocalTypedefNameCandidates;
4359   for (const TypedefNameDecl *TD : SemaRef.UnusedLocalTypedefNameCandidates)
4360     AddDeclRef(TD, UnusedLocalTypedefNameCandidates);
4361 
4362   // Build a record containing all of dynamic classes declarations.
4363   RecordData DynamicClasses;
4364   AddLazyVectorDecls(*this, SemaRef.DynamicClasses, DynamicClasses);
4365 
4366   // Build a record containing all of pending implicit instantiations.
4367   RecordData PendingInstantiations;
4368   for (std::deque<Sema::PendingImplicitInstantiation>::iterator
4369          I = SemaRef.PendingInstantiations.begin(),
4370          N = SemaRef.PendingInstantiations.end(); I != N; ++I) {
4371     AddDeclRef(I->first, PendingInstantiations);
4372     AddSourceLocation(I->second, PendingInstantiations);
4373   }
4374   assert(SemaRef.PendingLocalImplicitInstantiations.empty() &&
4375          "There are local ones at end of translation unit!");
4376 
4377   // Build a record containing some declaration references.
4378   RecordData SemaDeclRefs;
4379   if (SemaRef.StdNamespace || SemaRef.StdBadAlloc) {
4380     AddDeclRef(SemaRef.getStdNamespace(), SemaDeclRefs);
4381     AddDeclRef(SemaRef.getStdBadAlloc(), SemaDeclRefs);
4382   }
4383 
4384   RecordData CUDASpecialDeclRefs;
4385   if (Context.getcudaConfigureCallDecl()) {
4386     AddDeclRef(Context.getcudaConfigureCallDecl(), CUDASpecialDeclRefs);
4387   }
4388 
4389   // Build a record containing all of the known namespaces.
4390   RecordData KnownNamespaces;
4391   for (llvm::MapVector<NamespaceDecl*, bool>::iterator
4392             I = SemaRef.KnownNamespaces.begin(),
4393          IEnd = SemaRef.KnownNamespaces.end();
4394        I != IEnd; ++I) {
4395     if (!I->second)
4396       AddDeclRef(I->first, KnownNamespaces);
4397   }
4398 
4399   // Build a record of all used, undefined objects that require definitions.
4400   RecordData UndefinedButUsed;
4401 
4402   SmallVector<std::pair<NamedDecl *, SourceLocation>, 16> Undefined;
4403   SemaRef.getUndefinedButUsed(Undefined);
4404   for (SmallVectorImpl<std::pair<NamedDecl *, SourceLocation> >::iterator
4405          I = Undefined.begin(), E = Undefined.end(); I != E; ++I) {
4406     AddDeclRef(I->first, UndefinedButUsed);
4407     AddSourceLocation(I->second, UndefinedButUsed);
4408   }
4409 
4410   // Write the control block
4411   WriteControlBlock(PP, Context, isysroot, OutputFile);
4412 
4413   // Write the remaining AST contents.
4414   RecordData Record;
4415   Stream.EnterSubblock(AST_BLOCK_ID, 5);
4416 
4417   // This is so that older clang versions, before the introduction
4418   // of the control block, can read and reject the newer PCH format.
4419   Record.clear();
4420   Record.push_back(VERSION_MAJOR);
4421   Stream.EmitRecord(METADATA_OLD_FORMAT, Record);
4422 
4423   // Create a lexical update block containing all of the declarations in the
4424   // translation unit that do not come from other AST files.
4425   const TranslationUnitDecl *TU = Context.getTranslationUnitDecl();
4426   SmallVector<KindDeclIDPair, 64> NewGlobalDecls;
4427   for (const auto *I : TU->noload_decls()) {
4428     if (!I->isFromASTFile())
4429       NewGlobalDecls.push_back(std::make_pair(I->getKind(), GetDeclRef(I)));
4430   }
4431 
4432   llvm::BitCodeAbbrev *Abv = new llvm::BitCodeAbbrev();
4433   Abv->Add(llvm::BitCodeAbbrevOp(TU_UPDATE_LEXICAL));
4434   Abv->Add(llvm::BitCodeAbbrevOp(llvm::BitCodeAbbrevOp::Blob));
4435   unsigned TuUpdateLexicalAbbrev = Stream.EmitAbbrev(Abv);
4436   Record.clear();
4437   Record.push_back(TU_UPDATE_LEXICAL);
4438   Stream.EmitRecordWithBlob(TuUpdateLexicalAbbrev, Record,
4439                             data(NewGlobalDecls));
4440 
4441   // And a visible updates block for the translation unit.
4442   Abv = new llvm::BitCodeAbbrev();
4443   Abv->Add(llvm::BitCodeAbbrevOp(UPDATE_VISIBLE));
4444   Abv->Add(llvm::BitCodeAbbrevOp(llvm::BitCodeAbbrevOp::VBR, 6));
4445   Abv->Add(llvm::BitCodeAbbrevOp(llvm::BitCodeAbbrevOp::Fixed, 32));
4446   Abv->Add(llvm::BitCodeAbbrevOp(llvm::BitCodeAbbrevOp::Blob));
4447   UpdateVisibleAbbrev = Stream.EmitAbbrev(Abv);
4448   WriteDeclContextVisibleUpdate(TU);
4449 
4450   // If the translation unit has an anonymous namespace, and we don't already
4451   // have an update block for it, write it as an update block.
4452   // FIXME: Why do we not do this if there's already an update block?
4453   if (NamespaceDecl *NS = TU->getAnonymousNamespace()) {
4454     ASTWriter::UpdateRecord &Record = DeclUpdates[TU];
4455     if (Record.empty())
4456       Record.push_back(DeclUpdate(UPD_CXX_ADDED_ANONYMOUS_NAMESPACE, NS));
4457   }
4458 
4459   // Add update records for all mangling numbers and static local numbers.
4460   // These aren't really update records, but this is a convenient way of
4461   // tagging this rare extra data onto the declarations.
4462   for (const auto &Number : Context.MangleNumbers)
4463     if (!Number.first->isFromASTFile())
4464       DeclUpdates[Number.first].push_back(DeclUpdate(UPD_MANGLING_NUMBER,
4465                                                      Number.second));
4466   for (const auto &Number : Context.StaticLocalNumbers)
4467     if (!Number.first->isFromASTFile())
4468       DeclUpdates[Number.first].push_back(DeclUpdate(UPD_STATIC_LOCAL_NUMBER,
4469                                                      Number.second));
4470 
4471   // Make sure visible decls, added to DeclContexts previously loaded from
4472   // an AST file, are registered for serialization.
4473   for (SmallVectorImpl<const Decl *>::iterator
4474          I = UpdatingVisibleDecls.begin(),
4475          E = UpdatingVisibleDecls.end(); I != E; ++I) {
4476     GetDeclRef(*I);
4477   }
4478 
4479   // Make sure all decls associated with an identifier are registered for
4480   // serialization.
4481   for (IdentifierTable::iterator ID = PP.getIdentifierTable().begin(),
4482                               IDEnd = PP.getIdentifierTable().end();
4483        ID != IDEnd; ++ID) {
4484     const IdentifierInfo *II = ID->second;
4485     if (!Chain || !II->isFromAST() || II->hasChangedSinceDeserialization()) {
4486       for (IdentifierResolver::iterator D = SemaRef.IdResolver.begin(II),
4487                                      DEnd = SemaRef.IdResolver.end();
4488            D != DEnd; ++D) {
4489         GetDeclRef(*D);
4490       }
4491     }
4492   }
4493 
4494   // Form the record of special types.
4495   RecordData SpecialTypes;
4496   AddTypeRef(Context.getRawCFConstantStringType(), SpecialTypes);
4497   AddTypeRef(Context.getFILEType(), SpecialTypes);
4498   AddTypeRef(Context.getjmp_bufType(), SpecialTypes);
4499   AddTypeRef(Context.getsigjmp_bufType(), SpecialTypes);
4500   AddTypeRef(Context.ObjCIdRedefinitionType, SpecialTypes);
4501   AddTypeRef(Context.ObjCClassRedefinitionType, SpecialTypes);
4502   AddTypeRef(Context.ObjCSelRedefinitionType, SpecialTypes);
4503   AddTypeRef(Context.getucontext_tType(), SpecialTypes);
4504 
4505   if (Chain) {
4506     // Write the mapping information describing our module dependencies and how
4507     // each of those modules were mapped into our own offset/ID space, so that
4508     // the reader can build the appropriate mapping to its own offset/ID space.
4509     // The map consists solely of a blob with the following format:
4510     // *(module-name-len:i16 module-name:len*i8
4511     //   source-location-offset:i32
4512     //   identifier-id:i32
4513     //   preprocessed-entity-id:i32
4514     //   macro-definition-id:i32
4515     //   submodule-id:i32
4516     //   selector-id:i32
4517     //   declaration-id:i32
4518     //   c++-base-specifiers-id:i32
4519     //   type-id:i32)
4520     //
4521     llvm::BitCodeAbbrev *Abbrev = new BitCodeAbbrev();
4522     Abbrev->Add(BitCodeAbbrevOp(MODULE_OFFSET_MAP));
4523     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
4524     unsigned ModuleOffsetMapAbbrev = Stream.EmitAbbrev(Abbrev);
4525     SmallString<2048> Buffer;
4526     {
4527       llvm::raw_svector_ostream Out(Buffer);
4528       for (ModuleFile *M : Chain->ModuleMgr) {
4529         using namespace llvm::support;
4530         endian::Writer<little> LE(Out);
4531         StringRef FileName = M->FileName;
4532         LE.write<uint16_t>(FileName.size());
4533         Out.write(FileName.data(), FileName.size());
4534 
4535         // Note: if a base ID was uint max, it would not be possible to load
4536         // another module after it or have more than one entity inside it.
4537         uint32_t None = std::numeric_limits<uint32_t>::max();
4538 
4539         auto writeBaseIDOrNone = [&](uint32_t BaseID, bool ShouldWrite) {
4540           assert(BaseID < std::numeric_limits<uint32_t>::max() && "base id too high");
4541           if (ShouldWrite)
4542             LE.write<uint32_t>(BaseID);
4543           else
4544             LE.write<uint32_t>(None);
4545         };
4546 
4547         // These values should be unique within a chain, since they will be read
4548         // as keys into ContinuousRangeMaps.
4549         writeBaseIDOrNone(M->SLocEntryBaseOffset, M->LocalNumSLocEntries);
4550         writeBaseIDOrNone(M->BaseIdentifierID, M->LocalNumIdentifiers);
4551         writeBaseIDOrNone(M->BaseMacroID, M->LocalNumMacros);
4552         writeBaseIDOrNone(M->BasePreprocessedEntityID,
4553                           M->NumPreprocessedEntities);
4554         writeBaseIDOrNone(M->BaseSubmoduleID, M->LocalNumSubmodules);
4555         writeBaseIDOrNone(M->BaseSelectorID, M->LocalNumSelectors);
4556         writeBaseIDOrNone(M->BaseDeclID, M->LocalNumDecls);
4557         writeBaseIDOrNone(M->BaseTypeIndex, M->LocalNumTypes);
4558       }
4559     }
4560     Record.clear();
4561     Record.push_back(MODULE_OFFSET_MAP);
4562     Stream.EmitRecordWithBlob(ModuleOffsetMapAbbrev, Record,
4563                               Buffer.data(), Buffer.size());
4564   }
4565 
4566   RecordData DeclUpdatesOffsetsRecord;
4567 
4568   // Keep writing types, declarations, and declaration update records
4569   // until we've emitted all of them.
4570   Stream.EnterSubblock(DECLTYPES_BLOCK_ID, /*bits for abbreviations*/5);
4571   WriteTypeAbbrevs();
4572   WriteDeclAbbrevs();
4573   for (DeclsToRewriteTy::iterator I = DeclsToRewrite.begin(),
4574                                   E = DeclsToRewrite.end();
4575        I != E; ++I)
4576     DeclTypesToEmit.push(const_cast<Decl*>(*I));
4577   do {
4578     WriteDeclUpdatesBlocks(DeclUpdatesOffsetsRecord);
4579     while (!DeclTypesToEmit.empty()) {
4580       DeclOrType DOT = DeclTypesToEmit.front();
4581       DeclTypesToEmit.pop();
4582       if (DOT.isType())
4583         WriteType(DOT.getType());
4584       else
4585         WriteDecl(Context, DOT.getDecl());
4586     }
4587   } while (!DeclUpdates.empty());
4588   Stream.ExitBlock();
4589 
4590   DoneWritingDeclsAndTypes = true;
4591 
4592   // These things can only be done once we've written out decls and types.
4593   WriteTypeDeclOffsets();
4594   if (!DeclUpdatesOffsetsRecord.empty())
4595     Stream.EmitRecord(DECL_UPDATE_OFFSETS, DeclUpdatesOffsetsRecord);
4596   WriteCXXBaseSpecifiersOffsets();
4597   WriteFileDeclIDsMap();
4598   WriteSourceManagerBlock(Context.getSourceManager(), PP);
4599 
4600   WriteComments();
4601   WritePreprocessor(PP, isModule);
4602   WriteHeaderSearch(PP.getHeaderSearchInfo());
4603   WriteSelectors(SemaRef);
4604   WriteReferencedSelectorsPool(SemaRef);
4605   WriteIdentifierTable(PP, SemaRef.IdResolver, isModule);
4606   WriteFPPragmaOptions(SemaRef.getFPOptions());
4607   WriteOpenCLExtensions(SemaRef);
4608   WritePragmaDiagnosticMappings(Context.getDiagnostics(), isModule);
4609 
4610   // If we're emitting a module, write out the submodule information.
4611   if (WritingModule)
4612     WriteSubmodules(WritingModule);
4613 
4614   Stream.EmitRecord(SPECIAL_TYPES, SpecialTypes);
4615 
4616   // Write the record containing external, unnamed definitions.
4617   if (!EagerlyDeserializedDecls.empty())
4618     Stream.EmitRecord(EAGERLY_DESERIALIZED_DECLS, EagerlyDeserializedDecls);
4619 
4620   // Write the record containing tentative definitions.
4621   if (!TentativeDefinitions.empty())
4622     Stream.EmitRecord(TENTATIVE_DEFINITIONS, TentativeDefinitions);
4623 
4624   // Write the record containing unused file scoped decls.
4625   if (!UnusedFileScopedDecls.empty())
4626     Stream.EmitRecord(UNUSED_FILESCOPED_DECLS, UnusedFileScopedDecls);
4627 
4628   // Write the record containing weak undeclared identifiers.
4629   if (!WeakUndeclaredIdentifiers.empty())
4630     Stream.EmitRecord(WEAK_UNDECLARED_IDENTIFIERS,
4631                       WeakUndeclaredIdentifiers);
4632 
4633   // Write the record containing locally-scoped extern "C" definitions.
4634   if (!LocallyScopedExternCDecls.empty())
4635     Stream.EmitRecord(LOCALLY_SCOPED_EXTERN_C_DECLS,
4636                       LocallyScopedExternCDecls);
4637 
4638   // Write the record containing ext_vector type names.
4639   if (!ExtVectorDecls.empty())
4640     Stream.EmitRecord(EXT_VECTOR_DECLS, ExtVectorDecls);
4641 
4642   // Write the record containing VTable uses information.
4643   if (!VTableUses.empty())
4644     Stream.EmitRecord(VTABLE_USES, VTableUses);
4645 
4646   // Write the record containing dynamic classes declarations.
4647   if (!DynamicClasses.empty())
4648     Stream.EmitRecord(DYNAMIC_CLASSES, DynamicClasses);
4649 
4650   // Write the record containing potentially unused local typedefs.
4651   if (!UnusedLocalTypedefNameCandidates.empty())
4652     Stream.EmitRecord(UNUSED_LOCAL_TYPEDEF_NAME_CANDIDATES,
4653                       UnusedLocalTypedefNameCandidates);
4654 
4655   // Write the record containing pending implicit instantiations.
4656   if (!PendingInstantiations.empty())
4657     Stream.EmitRecord(PENDING_IMPLICIT_INSTANTIATIONS, PendingInstantiations);
4658 
4659   // Write the record containing declaration references of Sema.
4660   if (!SemaDeclRefs.empty())
4661     Stream.EmitRecord(SEMA_DECL_REFS, SemaDeclRefs);
4662 
4663   // Write the record containing CUDA-specific declaration references.
4664   if (!CUDASpecialDeclRefs.empty())
4665     Stream.EmitRecord(CUDA_SPECIAL_DECL_REFS, CUDASpecialDeclRefs);
4666 
4667   // Write the delegating constructors.
4668   if (!DelegatingCtorDecls.empty())
4669     Stream.EmitRecord(DELEGATING_CTORS, DelegatingCtorDecls);
4670 
4671   // Write the known namespaces.
4672   if (!KnownNamespaces.empty())
4673     Stream.EmitRecord(KNOWN_NAMESPACES, KnownNamespaces);
4674 
4675   // Write the undefined internal functions and variables, and inline functions.
4676   if (!UndefinedButUsed.empty())
4677     Stream.EmitRecord(UNDEFINED_BUT_USED, UndefinedButUsed);
4678 
4679   // Write the visible updates to DeclContexts.
4680   for (auto *DC : UpdatedDeclContexts)
4681     WriteDeclContextVisibleUpdate(DC);
4682 
4683   if (!WritingModule) {
4684     // Write the submodules that were imported, if any.
4685     struct ModuleInfo {
4686       uint64_t ID;
4687       Module *M;
4688       ModuleInfo(uint64_t ID, Module *M) : ID(ID), M(M) {}
4689     };
4690     llvm::SmallVector<ModuleInfo, 64> Imports;
4691     for (const auto *I : Context.local_imports()) {
4692       assert(SubmoduleIDs.find(I->getImportedModule()) != SubmoduleIDs.end());
4693       Imports.push_back(ModuleInfo(SubmoduleIDs[I->getImportedModule()],
4694                          I->getImportedModule()));
4695     }
4696 
4697     if (!Imports.empty()) {
4698       auto Cmp = [](const ModuleInfo &A, const ModuleInfo &B) {
4699         return A.ID < B.ID;
4700       };
4701       auto Eq = [](const ModuleInfo &A, const ModuleInfo &B) {
4702         return A.ID == B.ID;
4703       };
4704 
4705       // Sort and deduplicate module IDs.
4706       std::sort(Imports.begin(), Imports.end(), Cmp);
4707       Imports.erase(std::unique(Imports.begin(), Imports.end(), Eq),
4708                     Imports.end());
4709 
4710       RecordData ImportedModules;
4711       for (const auto &Import : Imports) {
4712         ImportedModules.push_back(Import.ID);
4713         // FIXME: If the module has macros imported then later has declarations
4714         // imported, this location won't be the right one as a location for the
4715         // declaration imports.
4716         AddSourceLocation(Import.M->MacroVisibilityLoc, ImportedModules);
4717       }
4718 
4719       Stream.EmitRecord(IMPORTED_MODULES, ImportedModules);
4720     }
4721   }
4722 
4723   WriteDeclReplacementsBlock();
4724   WriteRedeclarations();
4725   WriteMergedDecls();
4726   WriteObjCCategories();
4727   WriteLateParsedTemplates(SemaRef);
4728   if(!WritingModule)
4729     WriteOptimizePragmaOptions(SemaRef);
4730 
4731   // Some simple statistics
4732   Record.clear();
4733   Record.push_back(NumStatements);
4734   Record.push_back(NumMacros);
4735   Record.push_back(NumLexicalDeclContexts);
4736   Record.push_back(NumVisibleDeclContexts);
4737   Stream.EmitRecord(STATISTICS, Record);
4738   Stream.ExitBlock();
4739 }
4740 
4741 void ASTWriter::WriteDeclUpdatesBlocks(RecordDataImpl &OffsetsRecord) {
4742   if (DeclUpdates.empty())
4743     return;
4744 
4745   DeclUpdateMap LocalUpdates;
4746   LocalUpdates.swap(DeclUpdates);
4747 
4748   for (auto &DeclUpdate : LocalUpdates) {
4749     const Decl *D = DeclUpdate.first;
4750     if (isRewritten(D))
4751       continue; // The decl will be written completely,no need to store updates.
4752 
4753     bool HasUpdatedBody = false;
4754     RecordData Record;
4755     for (auto &Update : DeclUpdate.second) {
4756       DeclUpdateKind Kind = (DeclUpdateKind)Update.getKind();
4757 
4758       Record.push_back(Kind);
4759       switch (Kind) {
4760       case UPD_CXX_ADDED_IMPLICIT_MEMBER:
4761       case UPD_CXX_ADDED_TEMPLATE_SPECIALIZATION:
4762       case UPD_CXX_ADDED_ANONYMOUS_NAMESPACE:
4763         assert(Update.getDecl() && "no decl to add?");
4764         Record.push_back(GetDeclRef(Update.getDecl()));
4765         break;
4766 
4767       case UPD_CXX_ADDED_FUNCTION_DEFINITION:
4768         // An updated body is emitted last, so that the reader doesn't need
4769         // to skip over the lazy body to reach statements for other records.
4770         Record.pop_back();
4771         HasUpdatedBody = true;
4772         break;
4773 
4774       case UPD_CXX_INSTANTIATED_STATIC_DATA_MEMBER:
4775         AddSourceLocation(Update.getLoc(), Record);
4776         break;
4777 
4778       case UPD_CXX_INSTANTIATED_CLASS_DEFINITION: {
4779         auto *RD = cast<CXXRecordDecl>(D);
4780         AddUpdatedDeclContext(RD->getPrimaryContext());
4781         AddCXXDefinitionData(RD, Record);
4782         Record.push_back(WriteDeclContextLexicalBlock(
4783             *Context, const_cast<CXXRecordDecl *>(RD)));
4784 
4785         // This state is sometimes updated by template instantiation, when we
4786         // switch from the specialization referring to the template declaration
4787         // to it referring to the template definition.
4788         if (auto *MSInfo = RD->getMemberSpecializationInfo()) {
4789           Record.push_back(MSInfo->getTemplateSpecializationKind());
4790           AddSourceLocation(MSInfo->getPointOfInstantiation(), Record);
4791         } else {
4792           auto *Spec = cast<ClassTemplateSpecializationDecl>(RD);
4793           Record.push_back(Spec->getTemplateSpecializationKind());
4794           AddSourceLocation(Spec->getPointOfInstantiation(), Record);
4795 
4796           // The instantiation might have been resolved to a partial
4797           // specialization. If so, record which one.
4798           auto From = Spec->getInstantiatedFrom();
4799           if (auto PartialSpec =
4800                 From.dyn_cast<ClassTemplatePartialSpecializationDecl*>()) {
4801             Record.push_back(true);
4802             AddDeclRef(PartialSpec, Record);
4803             AddTemplateArgumentList(&Spec->getTemplateInstantiationArgs(),
4804                                     Record);
4805           } else {
4806             Record.push_back(false);
4807           }
4808         }
4809         Record.push_back(RD->getTagKind());
4810         AddSourceLocation(RD->getLocation(), Record);
4811         AddSourceLocation(RD->getLocStart(), Record);
4812         AddSourceLocation(RD->getRBraceLoc(), Record);
4813 
4814         // Instantiation may change attributes; write them all out afresh.
4815         Record.push_back(D->hasAttrs());
4816         if (Record.back())
4817           WriteAttributes(llvm::makeArrayRef(D->getAttrs().begin(),
4818                                              D->getAttrs().size()), Record);
4819 
4820         // FIXME: Ensure we don't get here for explicit instantiations.
4821         break;
4822       }
4823 
4824       case UPD_CXX_RESOLVED_EXCEPTION_SPEC:
4825         addExceptionSpec(
4826             *this,
4827             cast<FunctionDecl>(D)->getType()->castAs<FunctionProtoType>(),
4828             Record);
4829         break;
4830 
4831       case UPD_CXX_DEDUCED_RETURN_TYPE:
4832         Record.push_back(GetOrCreateTypeID(Update.getType()));
4833         break;
4834 
4835       case UPD_DECL_MARKED_USED:
4836         break;
4837 
4838       case UPD_MANGLING_NUMBER:
4839       case UPD_STATIC_LOCAL_NUMBER:
4840         Record.push_back(Update.getNumber());
4841         break;
4842       case UPD_DECL_MARKED_OPENMP_THREADPRIVATE:
4843         AddSourceRange(D->getAttr<OMPThreadPrivateDeclAttr>()->getRange(),
4844                        Record);
4845         break;
4846       }
4847     }
4848 
4849     if (HasUpdatedBody) {
4850       const FunctionDecl *Def = cast<FunctionDecl>(D);
4851       Record.push_back(UPD_CXX_ADDED_FUNCTION_DEFINITION);
4852       Record.push_back(Def->isInlined());
4853       AddSourceLocation(Def->getInnerLocStart(), Record);
4854       AddFunctionDefinition(Def, Record);
4855       if (auto *DD = dyn_cast<CXXDestructorDecl>(Def))
4856         Record.push_back(GetDeclRef(DD->getOperatorDelete()));
4857     }
4858 
4859     OffsetsRecord.push_back(GetDeclRef(D));
4860     OffsetsRecord.push_back(Stream.GetCurrentBitNo());
4861 
4862     Stream.EmitRecord(DECL_UPDATES, Record);
4863 
4864     // Flush any statements that were written as part of this update record.
4865     FlushStmts();
4866 
4867     // Flush C++ base specifiers, if there are any.
4868     FlushCXXBaseSpecifiers();
4869   }
4870 }
4871 
4872 void ASTWriter::WriteDeclReplacementsBlock() {
4873   if (ReplacedDecls.empty())
4874     return;
4875 
4876   RecordData Record;
4877   for (SmallVectorImpl<ReplacedDeclInfo>::iterator
4878          I = ReplacedDecls.begin(), E = ReplacedDecls.end(); I != E; ++I) {
4879     Record.push_back(I->ID);
4880     Record.push_back(I->Offset);
4881     Record.push_back(I->Loc);
4882   }
4883   Stream.EmitRecord(DECL_REPLACEMENTS, Record);
4884 }
4885 
4886 void ASTWriter::AddSourceLocation(SourceLocation Loc, RecordDataImpl &Record) {
4887   Record.push_back(Loc.getRawEncoding());
4888 }
4889 
4890 void ASTWriter::AddSourceRange(SourceRange Range, RecordDataImpl &Record) {
4891   AddSourceLocation(Range.getBegin(), Record);
4892   AddSourceLocation(Range.getEnd(), Record);
4893 }
4894 
4895 void ASTWriter::AddAPInt(const llvm::APInt &Value, RecordDataImpl &Record) {
4896   Record.push_back(Value.getBitWidth());
4897   const uint64_t *Words = Value.getRawData();
4898   Record.append(Words, Words + Value.getNumWords());
4899 }
4900 
4901 void ASTWriter::AddAPSInt(const llvm::APSInt &Value, RecordDataImpl &Record) {
4902   Record.push_back(Value.isUnsigned());
4903   AddAPInt(Value, Record);
4904 }
4905 
4906 void ASTWriter::AddAPFloat(const llvm::APFloat &Value, RecordDataImpl &Record) {
4907   AddAPInt(Value.bitcastToAPInt(), Record);
4908 }
4909 
4910 void ASTWriter::AddIdentifierRef(const IdentifierInfo *II, RecordDataImpl &Record) {
4911   Record.push_back(getIdentifierRef(II));
4912 }
4913 
4914 IdentID ASTWriter::getIdentifierRef(const IdentifierInfo *II) {
4915   if (!II)
4916     return 0;
4917 
4918   IdentID &ID = IdentifierIDs[II];
4919   if (ID == 0)
4920     ID = NextIdentID++;
4921   return ID;
4922 }
4923 
4924 MacroID ASTWriter::getMacroRef(MacroInfo *MI, const IdentifierInfo *Name) {
4925   // Don't emit builtin macros like __LINE__ to the AST file unless they
4926   // have been redefined by the header (in which case they are not
4927   // isBuiltinMacro).
4928   if (!MI || MI->isBuiltinMacro())
4929     return 0;
4930 
4931   MacroID &ID = MacroIDs[MI];
4932   if (ID == 0) {
4933     ID = NextMacroID++;
4934     MacroInfoToEmitData Info = { Name, MI, ID };
4935     MacroInfosToEmit.push_back(Info);
4936   }
4937   return ID;
4938 }
4939 
4940 MacroID ASTWriter::getMacroID(MacroInfo *MI) {
4941   if (!MI || MI->isBuiltinMacro())
4942     return 0;
4943 
4944   assert(MacroIDs.find(MI) != MacroIDs.end() && "Macro not emitted!");
4945   return MacroIDs[MI];
4946 }
4947 
4948 uint64_t ASTWriter::getMacroDirectivesOffset(const IdentifierInfo *Name) {
4949   assert(IdentMacroDirectivesOffsetMap[Name] && "not set!");
4950   return IdentMacroDirectivesOffsetMap[Name];
4951 }
4952 
4953 void ASTWriter::AddSelectorRef(const Selector SelRef, RecordDataImpl &Record) {
4954   Record.push_back(getSelectorRef(SelRef));
4955 }
4956 
4957 SelectorID ASTWriter::getSelectorRef(Selector Sel) {
4958   if (Sel.getAsOpaquePtr() == nullptr) {
4959     return 0;
4960   }
4961 
4962   SelectorID SID = SelectorIDs[Sel];
4963   if (SID == 0 && Chain) {
4964     // This might trigger a ReadSelector callback, which will set the ID for
4965     // this selector.
4966     Chain->LoadSelector(Sel);
4967     SID = SelectorIDs[Sel];
4968   }
4969   if (SID == 0) {
4970     SID = NextSelectorID++;
4971     SelectorIDs[Sel] = SID;
4972   }
4973   return SID;
4974 }
4975 
4976 void ASTWriter::AddCXXTemporary(const CXXTemporary *Temp, RecordDataImpl &Record) {
4977   AddDeclRef(Temp->getDestructor(), Record);
4978 }
4979 
4980 void ASTWriter::AddCXXBaseSpecifiersRef(CXXBaseSpecifier const *Bases,
4981                                       CXXBaseSpecifier const *BasesEnd,
4982                                         RecordDataImpl &Record) {
4983   assert(Bases != BasesEnd && "Empty base-specifier sets are not recorded");
4984   CXXBaseSpecifiersToWrite.push_back(
4985                                 QueuedCXXBaseSpecifiers(NextCXXBaseSpecifiersID,
4986                                                         Bases, BasesEnd));
4987   Record.push_back(NextCXXBaseSpecifiersID++);
4988 }
4989 
4990 void ASTWriter::AddTemplateArgumentLocInfo(TemplateArgument::ArgKind Kind,
4991                                            const TemplateArgumentLocInfo &Arg,
4992                                            RecordDataImpl &Record) {
4993   switch (Kind) {
4994   case TemplateArgument::Expression:
4995     AddStmt(Arg.getAsExpr());
4996     break;
4997   case TemplateArgument::Type:
4998     AddTypeSourceInfo(Arg.getAsTypeSourceInfo(), Record);
4999     break;
5000   case TemplateArgument::Template:
5001     AddNestedNameSpecifierLoc(Arg.getTemplateQualifierLoc(), Record);
5002     AddSourceLocation(Arg.getTemplateNameLoc(), Record);
5003     break;
5004   case TemplateArgument::TemplateExpansion:
5005     AddNestedNameSpecifierLoc(Arg.getTemplateQualifierLoc(), Record);
5006     AddSourceLocation(Arg.getTemplateNameLoc(), Record);
5007     AddSourceLocation(Arg.getTemplateEllipsisLoc(), Record);
5008     break;
5009   case TemplateArgument::Null:
5010   case TemplateArgument::Integral:
5011   case TemplateArgument::Declaration:
5012   case TemplateArgument::NullPtr:
5013   case TemplateArgument::Pack:
5014     // FIXME: Is this right?
5015     break;
5016   }
5017 }
5018 
5019 void ASTWriter::AddTemplateArgumentLoc(const TemplateArgumentLoc &Arg,
5020                                        RecordDataImpl &Record) {
5021   AddTemplateArgument(Arg.getArgument(), Record);
5022 
5023   if (Arg.getArgument().getKind() == TemplateArgument::Expression) {
5024     bool InfoHasSameExpr
5025       = Arg.getArgument().getAsExpr() == Arg.getLocInfo().getAsExpr();
5026     Record.push_back(InfoHasSameExpr);
5027     if (InfoHasSameExpr)
5028       return; // Avoid storing the same expr twice.
5029   }
5030   AddTemplateArgumentLocInfo(Arg.getArgument().getKind(), Arg.getLocInfo(),
5031                              Record);
5032 }
5033 
5034 void ASTWriter::AddTypeSourceInfo(TypeSourceInfo *TInfo,
5035                                   RecordDataImpl &Record) {
5036   if (!TInfo) {
5037     AddTypeRef(QualType(), Record);
5038     return;
5039   }
5040 
5041   AddTypeLoc(TInfo->getTypeLoc(), Record);
5042 }
5043 
5044 void ASTWriter::AddTypeLoc(TypeLoc TL, RecordDataImpl &Record) {
5045   AddTypeRef(TL.getType(), Record);
5046 
5047   TypeLocWriter TLW(*this, Record);
5048   for (; !TL.isNull(); TL = TL.getNextTypeLoc())
5049     TLW.Visit(TL);
5050 }
5051 
5052 void ASTWriter::AddTypeRef(QualType T, RecordDataImpl &Record) {
5053   Record.push_back(GetOrCreateTypeID(T));
5054 }
5055 
5056 TypeID ASTWriter::GetOrCreateTypeID( QualType T) {
5057   assert(Context);
5058   return MakeTypeID(*Context, T,
5059               std::bind1st(std::mem_fun(&ASTWriter::GetOrCreateTypeIdx), this));
5060 }
5061 
5062 TypeID ASTWriter::getTypeID(QualType T) const {
5063   assert(Context);
5064   return MakeTypeID(*Context, T,
5065               std::bind1st(std::mem_fun(&ASTWriter::getTypeIdx), this));
5066 }
5067 
5068 TypeIdx ASTWriter::GetOrCreateTypeIdx(QualType T) {
5069   if (T.isNull())
5070     return TypeIdx();
5071   assert(!T.getLocalFastQualifiers());
5072 
5073   TypeIdx &Idx = TypeIdxs[T];
5074   if (Idx.getIndex() == 0) {
5075     if (DoneWritingDeclsAndTypes) {
5076       assert(0 && "New type seen after serializing all the types to emit!");
5077       return TypeIdx();
5078     }
5079 
5080     // We haven't seen this type before. Assign it a new ID and put it
5081     // into the queue of types to emit.
5082     Idx = TypeIdx(NextTypeID++);
5083     DeclTypesToEmit.push(T);
5084   }
5085   return Idx;
5086 }
5087 
5088 TypeIdx ASTWriter::getTypeIdx(QualType T) const {
5089   if (T.isNull())
5090     return TypeIdx();
5091   assert(!T.getLocalFastQualifiers());
5092 
5093   TypeIdxMap::const_iterator I = TypeIdxs.find(T);
5094   assert(I != TypeIdxs.end() && "Type not emitted!");
5095   return I->second;
5096 }
5097 
5098 void ASTWriter::AddDeclRef(const Decl *D, RecordDataImpl &Record) {
5099   Record.push_back(GetDeclRef(D));
5100 }
5101 
5102 DeclID ASTWriter::GetDeclRef(const Decl *D) {
5103   assert(WritingAST && "Cannot request a declaration ID before AST writing");
5104 
5105   if (!D) {
5106     return 0;
5107   }
5108 
5109   // If D comes from an AST file, its declaration ID is already known and
5110   // fixed.
5111   if (D->isFromASTFile())
5112     return D->getGlobalID();
5113 
5114   assert(!(reinterpret_cast<uintptr_t>(D) & 0x01) && "Invalid decl pointer");
5115   DeclID &ID = DeclIDs[D];
5116   if (ID == 0) {
5117     if (DoneWritingDeclsAndTypes) {
5118       assert(0 && "New decl seen after serializing all the decls to emit!");
5119       return 0;
5120     }
5121 
5122     // We haven't seen this declaration before. Give it a new ID and
5123     // enqueue it in the list of declarations to emit.
5124     ID = NextDeclID++;
5125     DeclTypesToEmit.push(const_cast<Decl *>(D));
5126   }
5127 
5128   return ID;
5129 }
5130 
5131 DeclID ASTWriter::getDeclID(const Decl *D) {
5132   if (!D)
5133     return 0;
5134 
5135   // If D comes from an AST file, its declaration ID is already known and
5136   // fixed.
5137   if (D->isFromASTFile())
5138     return D->getGlobalID();
5139 
5140   assert(DeclIDs.find(D) != DeclIDs.end() && "Declaration not emitted!");
5141   return DeclIDs[D];
5142 }
5143 
5144 void ASTWriter::associateDeclWithFile(const Decl *D, DeclID ID) {
5145   assert(ID);
5146   assert(D);
5147 
5148   SourceLocation Loc = D->getLocation();
5149   if (Loc.isInvalid())
5150     return;
5151 
5152   // We only keep track of the file-level declarations of each file.
5153   if (!D->getLexicalDeclContext()->isFileContext())
5154     return;
5155   // FIXME: ParmVarDecls that are part of a function type of a parameter of
5156   // a function/objc method, should not have TU as lexical context.
5157   if (isa<ParmVarDecl>(D))
5158     return;
5159 
5160   SourceManager &SM = Context->getSourceManager();
5161   SourceLocation FileLoc = SM.getFileLoc(Loc);
5162   assert(SM.isLocalSourceLocation(FileLoc));
5163   FileID FID;
5164   unsigned Offset;
5165   std::tie(FID, Offset) = SM.getDecomposedLoc(FileLoc);
5166   if (FID.isInvalid())
5167     return;
5168   assert(SM.getSLocEntry(FID).isFile());
5169 
5170   DeclIDInFileInfo *&Info = FileDeclIDs[FID];
5171   if (!Info)
5172     Info = new DeclIDInFileInfo();
5173 
5174   std::pair<unsigned, serialization::DeclID> LocDecl(Offset, ID);
5175   LocDeclIDsTy &Decls = Info->DeclIDs;
5176 
5177   if (Decls.empty() || Decls.back().first <= Offset) {
5178     Decls.push_back(LocDecl);
5179     return;
5180   }
5181 
5182   LocDeclIDsTy::iterator I =
5183       std::upper_bound(Decls.begin(), Decls.end(), LocDecl, llvm::less_first());
5184 
5185   Decls.insert(I, LocDecl);
5186 }
5187 
5188 void ASTWriter::AddDeclarationName(DeclarationName Name, RecordDataImpl &Record) {
5189   // FIXME: Emit a stable enum for NameKind.  0 = Identifier etc.
5190   Record.push_back(Name.getNameKind());
5191   switch (Name.getNameKind()) {
5192   case DeclarationName::Identifier:
5193     AddIdentifierRef(Name.getAsIdentifierInfo(), Record);
5194     break;
5195 
5196   case DeclarationName::ObjCZeroArgSelector:
5197   case DeclarationName::ObjCOneArgSelector:
5198   case DeclarationName::ObjCMultiArgSelector:
5199     AddSelectorRef(Name.getObjCSelector(), Record);
5200     break;
5201 
5202   case DeclarationName::CXXConstructorName:
5203   case DeclarationName::CXXDestructorName:
5204   case DeclarationName::CXXConversionFunctionName:
5205     AddTypeRef(Name.getCXXNameType(), Record);
5206     break;
5207 
5208   case DeclarationName::CXXOperatorName:
5209     Record.push_back(Name.getCXXOverloadedOperator());
5210     break;
5211 
5212   case DeclarationName::CXXLiteralOperatorName:
5213     AddIdentifierRef(Name.getCXXLiteralIdentifier(), Record);
5214     break;
5215 
5216   case DeclarationName::CXXUsingDirective:
5217     // No extra data to emit
5218     break;
5219   }
5220 }
5221 
5222 unsigned ASTWriter::getAnonymousDeclarationNumber(const NamedDecl *D) {
5223   assert(needsAnonymousDeclarationNumber(D) &&
5224          "expected an anonymous declaration");
5225 
5226   // Number the anonymous declarations within this context, if we've not
5227   // already done so.
5228   auto It = AnonymousDeclarationNumbers.find(D);
5229   if (It == AnonymousDeclarationNumbers.end()) {
5230     auto *DC = D->getLexicalDeclContext();
5231     numberAnonymousDeclsWithin(DC, [&](const NamedDecl *ND, unsigned Number) {
5232       AnonymousDeclarationNumbers[ND] = Number;
5233     });
5234 
5235     It = AnonymousDeclarationNumbers.find(D);
5236     assert(It != AnonymousDeclarationNumbers.end() &&
5237            "declaration not found within its lexical context");
5238   }
5239 
5240   return It->second;
5241 }
5242 
5243 void ASTWriter::AddDeclarationNameLoc(const DeclarationNameLoc &DNLoc,
5244                                      DeclarationName Name, RecordDataImpl &Record) {
5245   switch (Name.getNameKind()) {
5246   case DeclarationName::CXXConstructorName:
5247   case DeclarationName::CXXDestructorName:
5248   case DeclarationName::CXXConversionFunctionName:
5249     AddTypeSourceInfo(DNLoc.NamedType.TInfo, Record);
5250     break;
5251 
5252   case DeclarationName::CXXOperatorName:
5253     AddSourceLocation(
5254        SourceLocation::getFromRawEncoding(DNLoc.CXXOperatorName.BeginOpNameLoc),
5255        Record);
5256     AddSourceLocation(
5257         SourceLocation::getFromRawEncoding(DNLoc.CXXOperatorName.EndOpNameLoc),
5258         Record);
5259     break;
5260 
5261   case DeclarationName::CXXLiteralOperatorName:
5262     AddSourceLocation(
5263      SourceLocation::getFromRawEncoding(DNLoc.CXXLiteralOperatorName.OpNameLoc),
5264      Record);
5265     break;
5266 
5267   case DeclarationName::Identifier:
5268   case DeclarationName::ObjCZeroArgSelector:
5269   case DeclarationName::ObjCOneArgSelector:
5270   case DeclarationName::ObjCMultiArgSelector:
5271   case DeclarationName::CXXUsingDirective:
5272     break;
5273   }
5274 }
5275 
5276 void ASTWriter::AddDeclarationNameInfo(const DeclarationNameInfo &NameInfo,
5277                                        RecordDataImpl &Record) {
5278   AddDeclarationName(NameInfo.getName(), Record);
5279   AddSourceLocation(NameInfo.getLoc(), Record);
5280   AddDeclarationNameLoc(NameInfo.getInfo(), NameInfo.getName(), Record);
5281 }
5282 
5283 void ASTWriter::AddQualifierInfo(const QualifierInfo &Info,
5284                                  RecordDataImpl &Record) {
5285   AddNestedNameSpecifierLoc(Info.QualifierLoc, Record);
5286   Record.push_back(Info.NumTemplParamLists);
5287   for (unsigned i=0, e=Info.NumTemplParamLists; i != e; ++i)
5288     AddTemplateParameterList(Info.TemplParamLists[i], Record);
5289 }
5290 
5291 void ASTWriter::AddNestedNameSpecifier(NestedNameSpecifier *NNS,
5292                                        RecordDataImpl &Record) {
5293   // Nested name specifiers usually aren't too long. I think that 8 would
5294   // typically accommodate the vast majority.
5295   SmallVector<NestedNameSpecifier *, 8> NestedNames;
5296 
5297   // Push each of the NNS's onto a stack for serialization in reverse order.
5298   while (NNS) {
5299     NestedNames.push_back(NNS);
5300     NNS = NNS->getPrefix();
5301   }
5302 
5303   Record.push_back(NestedNames.size());
5304   while(!NestedNames.empty()) {
5305     NNS = NestedNames.pop_back_val();
5306     NestedNameSpecifier::SpecifierKind Kind = NNS->getKind();
5307     Record.push_back(Kind);
5308     switch (Kind) {
5309     case NestedNameSpecifier::Identifier:
5310       AddIdentifierRef(NNS->getAsIdentifier(), Record);
5311       break;
5312 
5313     case NestedNameSpecifier::Namespace:
5314       AddDeclRef(NNS->getAsNamespace(), Record);
5315       break;
5316 
5317     case NestedNameSpecifier::NamespaceAlias:
5318       AddDeclRef(NNS->getAsNamespaceAlias(), Record);
5319       break;
5320 
5321     case NestedNameSpecifier::TypeSpec:
5322     case NestedNameSpecifier::TypeSpecWithTemplate:
5323       AddTypeRef(QualType(NNS->getAsType(), 0), Record);
5324       Record.push_back(Kind == NestedNameSpecifier::TypeSpecWithTemplate);
5325       break;
5326 
5327     case NestedNameSpecifier::Global:
5328       // Don't need to write an associated value.
5329       break;
5330 
5331     case NestedNameSpecifier::Super:
5332       AddDeclRef(NNS->getAsRecordDecl(), Record);
5333       break;
5334     }
5335   }
5336 }
5337 
5338 void ASTWriter::AddNestedNameSpecifierLoc(NestedNameSpecifierLoc NNS,
5339                                           RecordDataImpl &Record) {
5340   // Nested name specifiers usually aren't too long. I think that 8 would
5341   // typically accommodate the vast majority.
5342   SmallVector<NestedNameSpecifierLoc , 8> NestedNames;
5343 
5344   // Push each of the nested-name-specifiers's onto a stack for
5345   // serialization in reverse order.
5346   while (NNS) {
5347     NestedNames.push_back(NNS);
5348     NNS = NNS.getPrefix();
5349   }
5350 
5351   Record.push_back(NestedNames.size());
5352   while(!NestedNames.empty()) {
5353     NNS = NestedNames.pop_back_val();
5354     NestedNameSpecifier::SpecifierKind Kind
5355       = NNS.getNestedNameSpecifier()->getKind();
5356     Record.push_back(Kind);
5357     switch (Kind) {
5358     case NestedNameSpecifier::Identifier:
5359       AddIdentifierRef(NNS.getNestedNameSpecifier()->getAsIdentifier(), Record);
5360       AddSourceRange(NNS.getLocalSourceRange(), Record);
5361       break;
5362 
5363     case NestedNameSpecifier::Namespace:
5364       AddDeclRef(NNS.getNestedNameSpecifier()->getAsNamespace(), Record);
5365       AddSourceRange(NNS.getLocalSourceRange(), Record);
5366       break;
5367 
5368     case NestedNameSpecifier::NamespaceAlias:
5369       AddDeclRef(NNS.getNestedNameSpecifier()->getAsNamespaceAlias(), Record);
5370       AddSourceRange(NNS.getLocalSourceRange(), Record);
5371       break;
5372 
5373     case NestedNameSpecifier::TypeSpec:
5374     case NestedNameSpecifier::TypeSpecWithTemplate:
5375       Record.push_back(Kind == NestedNameSpecifier::TypeSpecWithTemplate);
5376       AddTypeLoc(NNS.getTypeLoc(), Record);
5377       AddSourceLocation(NNS.getLocalSourceRange().getEnd(), Record);
5378       break;
5379 
5380     case NestedNameSpecifier::Global:
5381       AddSourceLocation(NNS.getLocalSourceRange().getEnd(), Record);
5382       break;
5383 
5384     case NestedNameSpecifier::Super:
5385       AddDeclRef(NNS.getNestedNameSpecifier()->getAsRecordDecl(), Record);
5386       AddSourceRange(NNS.getLocalSourceRange(), Record);
5387       break;
5388     }
5389   }
5390 }
5391 
5392 void ASTWriter::AddTemplateName(TemplateName Name, RecordDataImpl &Record) {
5393   TemplateName::NameKind Kind = Name.getKind();
5394   Record.push_back(Kind);
5395   switch (Kind) {
5396   case TemplateName::Template:
5397     AddDeclRef(Name.getAsTemplateDecl(), Record);
5398     break;
5399 
5400   case TemplateName::OverloadedTemplate: {
5401     OverloadedTemplateStorage *OvT = Name.getAsOverloadedTemplate();
5402     Record.push_back(OvT->size());
5403     for (OverloadedTemplateStorage::iterator I = OvT->begin(), E = OvT->end();
5404            I != E; ++I)
5405       AddDeclRef(*I, Record);
5406     break;
5407   }
5408 
5409   case TemplateName::QualifiedTemplate: {
5410     QualifiedTemplateName *QualT = Name.getAsQualifiedTemplateName();
5411     AddNestedNameSpecifier(QualT->getQualifier(), Record);
5412     Record.push_back(QualT->hasTemplateKeyword());
5413     AddDeclRef(QualT->getTemplateDecl(), Record);
5414     break;
5415   }
5416 
5417   case TemplateName::DependentTemplate: {
5418     DependentTemplateName *DepT = Name.getAsDependentTemplateName();
5419     AddNestedNameSpecifier(DepT->getQualifier(), Record);
5420     Record.push_back(DepT->isIdentifier());
5421     if (DepT->isIdentifier())
5422       AddIdentifierRef(DepT->getIdentifier(), Record);
5423     else
5424       Record.push_back(DepT->getOperator());
5425     break;
5426   }
5427 
5428   case TemplateName::SubstTemplateTemplateParm: {
5429     SubstTemplateTemplateParmStorage *subst
5430       = Name.getAsSubstTemplateTemplateParm();
5431     AddDeclRef(subst->getParameter(), Record);
5432     AddTemplateName(subst->getReplacement(), Record);
5433     break;
5434   }
5435 
5436   case TemplateName::SubstTemplateTemplateParmPack: {
5437     SubstTemplateTemplateParmPackStorage *SubstPack
5438       = Name.getAsSubstTemplateTemplateParmPack();
5439     AddDeclRef(SubstPack->getParameterPack(), Record);
5440     AddTemplateArgument(SubstPack->getArgumentPack(), Record);
5441     break;
5442   }
5443   }
5444 }
5445 
5446 void ASTWriter::AddTemplateArgument(const TemplateArgument &Arg,
5447                                     RecordDataImpl &Record) {
5448   Record.push_back(Arg.getKind());
5449   switch (Arg.getKind()) {
5450   case TemplateArgument::Null:
5451     break;
5452   case TemplateArgument::Type:
5453     AddTypeRef(Arg.getAsType(), Record);
5454     break;
5455   case TemplateArgument::Declaration:
5456     AddDeclRef(Arg.getAsDecl(), Record);
5457     AddTypeRef(Arg.getParamTypeForDecl(), Record);
5458     break;
5459   case TemplateArgument::NullPtr:
5460     AddTypeRef(Arg.getNullPtrType(), Record);
5461     break;
5462   case TemplateArgument::Integral:
5463     AddAPSInt(Arg.getAsIntegral(), Record);
5464     AddTypeRef(Arg.getIntegralType(), Record);
5465     break;
5466   case TemplateArgument::Template:
5467     AddTemplateName(Arg.getAsTemplateOrTemplatePattern(), Record);
5468     break;
5469   case TemplateArgument::TemplateExpansion:
5470     AddTemplateName(Arg.getAsTemplateOrTemplatePattern(), Record);
5471     if (Optional<unsigned> NumExpansions = Arg.getNumTemplateExpansions())
5472       Record.push_back(*NumExpansions + 1);
5473     else
5474       Record.push_back(0);
5475     break;
5476   case TemplateArgument::Expression:
5477     AddStmt(Arg.getAsExpr());
5478     break;
5479   case TemplateArgument::Pack:
5480     Record.push_back(Arg.pack_size());
5481     for (const auto &P : Arg.pack_elements())
5482       AddTemplateArgument(P, Record);
5483     break;
5484   }
5485 }
5486 
5487 void
5488 ASTWriter::AddTemplateParameterList(const TemplateParameterList *TemplateParams,
5489                                     RecordDataImpl &Record) {
5490   assert(TemplateParams && "No TemplateParams!");
5491   AddSourceLocation(TemplateParams->getTemplateLoc(), Record);
5492   AddSourceLocation(TemplateParams->getLAngleLoc(), Record);
5493   AddSourceLocation(TemplateParams->getRAngleLoc(), Record);
5494   Record.push_back(TemplateParams->size());
5495   for (TemplateParameterList::const_iterator
5496          P = TemplateParams->begin(), PEnd = TemplateParams->end();
5497          P != PEnd; ++P)
5498     AddDeclRef(*P, Record);
5499 }
5500 
5501 /// \brief Emit a template argument list.
5502 void
5503 ASTWriter::AddTemplateArgumentList(const TemplateArgumentList *TemplateArgs,
5504                                    RecordDataImpl &Record) {
5505   assert(TemplateArgs && "No TemplateArgs!");
5506   Record.push_back(TemplateArgs->size());
5507   for (int i=0, e = TemplateArgs->size(); i != e; ++i)
5508     AddTemplateArgument(TemplateArgs->get(i), Record);
5509 }
5510 
5511 void
5512 ASTWriter::AddASTTemplateArgumentListInfo
5513 (const ASTTemplateArgumentListInfo *ASTTemplArgList, RecordDataImpl &Record) {
5514   assert(ASTTemplArgList && "No ASTTemplArgList!");
5515   AddSourceLocation(ASTTemplArgList->LAngleLoc, Record);
5516   AddSourceLocation(ASTTemplArgList->RAngleLoc, Record);
5517   Record.push_back(ASTTemplArgList->NumTemplateArgs);
5518   const TemplateArgumentLoc *TemplArgs = ASTTemplArgList->getTemplateArgs();
5519   for (int i=0, e = ASTTemplArgList->NumTemplateArgs; i != e; ++i)
5520     AddTemplateArgumentLoc(TemplArgs[i], Record);
5521 }
5522 
5523 void
5524 ASTWriter::AddUnresolvedSet(const ASTUnresolvedSet &Set, RecordDataImpl &Record) {
5525   Record.push_back(Set.size());
5526   for (ASTUnresolvedSet::const_iterator
5527          I = Set.begin(), E = Set.end(); I != E; ++I) {
5528     AddDeclRef(I.getDecl(), Record);
5529     Record.push_back(I.getAccess());
5530   }
5531 }
5532 
5533 void ASTWriter::AddCXXBaseSpecifier(const CXXBaseSpecifier &Base,
5534                                     RecordDataImpl &Record) {
5535   Record.push_back(Base.isVirtual());
5536   Record.push_back(Base.isBaseOfClass());
5537   Record.push_back(Base.getAccessSpecifierAsWritten());
5538   Record.push_back(Base.getInheritConstructors());
5539   AddTypeSourceInfo(Base.getTypeSourceInfo(), Record);
5540   AddSourceRange(Base.getSourceRange(), Record);
5541   AddSourceLocation(Base.isPackExpansion()? Base.getEllipsisLoc()
5542                                           : SourceLocation(),
5543                     Record);
5544 }
5545 
5546 void ASTWriter::FlushCXXBaseSpecifiers() {
5547   RecordData Record;
5548   for (unsigned I = 0, N = CXXBaseSpecifiersToWrite.size(); I != N; ++I) {
5549     Record.clear();
5550 
5551     // Record the offset of this base-specifier set.
5552     unsigned Index = CXXBaseSpecifiersToWrite[I].ID - 1;
5553     if (Index == CXXBaseSpecifiersOffsets.size())
5554       CXXBaseSpecifiersOffsets.push_back(Stream.GetCurrentBitNo());
5555     else {
5556       if (Index > CXXBaseSpecifiersOffsets.size())
5557         CXXBaseSpecifiersOffsets.resize(Index + 1);
5558       CXXBaseSpecifiersOffsets[Index] = Stream.GetCurrentBitNo();
5559     }
5560 
5561     const CXXBaseSpecifier *B = CXXBaseSpecifiersToWrite[I].Bases,
5562                         *BEnd = CXXBaseSpecifiersToWrite[I].BasesEnd;
5563     Record.push_back(BEnd - B);
5564     for (; B != BEnd; ++B)
5565       AddCXXBaseSpecifier(*B, Record);
5566     Stream.EmitRecord(serialization::DECL_CXX_BASE_SPECIFIERS, Record);
5567 
5568     // Flush any expressions that were written as part of the base specifiers.
5569     FlushStmts();
5570   }
5571 
5572   CXXBaseSpecifiersToWrite.clear();
5573 }
5574 
5575 void ASTWriter::AddCXXCtorInitializers(
5576                              const CXXCtorInitializer * const *CtorInitializers,
5577                              unsigned NumCtorInitializers,
5578                              RecordDataImpl &Record) {
5579   Record.push_back(NumCtorInitializers);
5580   for (unsigned i=0; i != NumCtorInitializers; ++i) {
5581     const CXXCtorInitializer *Init = CtorInitializers[i];
5582 
5583     if (Init->isBaseInitializer()) {
5584       Record.push_back(CTOR_INITIALIZER_BASE);
5585       AddTypeSourceInfo(Init->getTypeSourceInfo(), Record);
5586       Record.push_back(Init->isBaseVirtual());
5587     } else if (Init->isDelegatingInitializer()) {
5588       Record.push_back(CTOR_INITIALIZER_DELEGATING);
5589       AddTypeSourceInfo(Init->getTypeSourceInfo(), Record);
5590     } else if (Init->isMemberInitializer()){
5591       Record.push_back(CTOR_INITIALIZER_MEMBER);
5592       AddDeclRef(Init->getMember(), Record);
5593     } else {
5594       Record.push_back(CTOR_INITIALIZER_INDIRECT_MEMBER);
5595       AddDeclRef(Init->getIndirectMember(), Record);
5596     }
5597 
5598     AddSourceLocation(Init->getMemberLocation(), Record);
5599     AddStmt(Init->getInit());
5600     AddSourceLocation(Init->getLParenLoc(), Record);
5601     AddSourceLocation(Init->getRParenLoc(), Record);
5602     Record.push_back(Init->isWritten());
5603     if (Init->isWritten()) {
5604       Record.push_back(Init->getSourceOrder());
5605     } else {
5606       Record.push_back(Init->getNumArrayIndices());
5607       for (unsigned i=0, e=Init->getNumArrayIndices(); i != e; ++i)
5608         AddDeclRef(Init->getArrayIndex(i), Record);
5609     }
5610   }
5611 }
5612 
5613 void ASTWriter::AddCXXDefinitionData(const CXXRecordDecl *D, RecordDataImpl &Record) {
5614   auto &Data = D->data();
5615   Record.push_back(Data.IsLambda);
5616   Record.push_back(Data.UserDeclaredConstructor);
5617   Record.push_back(Data.UserDeclaredSpecialMembers);
5618   Record.push_back(Data.Aggregate);
5619   Record.push_back(Data.PlainOldData);
5620   Record.push_back(Data.Empty);
5621   Record.push_back(Data.Polymorphic);
5622   Record.push_back(Data.Abstract);
5623   Record.push_back(Data.IsStandardLayout);
5624   Record.push_back(Data.HasNoNonEmptyBases);
5625   Record.push_back(Data.HasPrivateFields);
5626   Record.push_back(Data.HasProtectedFields);
5627   Record.push_back(Data.HasPublicFields);
5628   Record.push_back(Data.HasMutableFields);
5629   Record.push_back(Data.HasVariantMembers);
5630   Record.push_back(Data.HasOnlyCMembers);
5631   Record.push_back(Data.HasInClassInitializer);
5632   Record.push_back(Data.HasUninitializedReferenceMember);
5633   Record.push_back(Data.NeedOverloadResolutionForMoveConstructor);
5634   Record.push_back(Data.NeedOverloadResolutionForMoveAssignment);
5635   Record.push_back(Data.NeedOverloadResolutionForDestructor);
5636   Record.push_back(Data.DefaultedMoveConstructorIsDeleted);
5637   Record.push_back(Data.DefaultedMoveAssignmentIsDeleted);
5638   Record.push_back(Data.DefaultedDestructorIsDeleted);
5639   Record.push_back(Data.HasTrivialSpecialMembers);
5640   Record.push_back(Data.DeclaredNonTrivialSpecialMembers);
5641   Record.push_back(Data.HasIrrelevantDestructor);
5642   Record.push_back(Data.HasConstexprNonCopyMoveConstructor);
5643   Record.push_back(Data.DefaultedDefaultConstructorIsConstexpr);
5644   Record.push_back(Data.HasConstexprDefaultConstructor);
5645   Record.push_back(Data.HasNonLiteralTypeFieldsOrBases);
5646   Record.push_back(Data.ComputedVisibleConversions);
5647   Record.push_back(Data.UserProvidedDefaultConstructor);
5648   Record.push_back(Data.DeclaredSpecialMembers);
5649   Record.push_back(Data.ImplicitCopyConstructorHasConstParam);
5650   Record.push_back(Data.ImplicitCopyAssignmentHasConstParam);
5651   Record.push_back(Data.HasDeclaredCopyConstructorWithConstParam);
5652   Record.push_back(Data.HasDeclaredCopyAssignmentWithConstParam);
5653   // IsLambda bit is already saved.
5654 
5655   Record.push_back(Data.NumBases);
5656   if (Data.NumBases > 0)
5657     AddCXXBaseSpecifiersRef(Data.getBases(), Data.getBases() + Data.NumBases,
5658                             Record);
5659 
5660   // FIXME: Make VBases lazily computed when needed to avoid storing them.
5661   Record.push_back(Data.NumVBases);
5662   if (Data.NumVBases > 0)
5663     AddCXXBaseSpecifiersRef(Data.getVBases(), Data.getVBases() + Data.NumVBases,
5664                             Record);
5665 
5666   AddUnresolvedSet(Data.Conversions.get(*Context), Record);
5667   AddUnresolvedSet(Data.VisibleConversions.get(*Context), Record);
5668   // Data.Definition is the owning decl, no need to write it.
5669   AddDeclRef(D->getFirstFriend(), Record);
5670 
5671   // Add lambda-specific data.
5672   if (Data.IsLambda) {
5673     auto &Lambda = D->getLambdaData();
5674     Record.push_back(Lambda.Dependent);
5675     Record.push_back(Lambda.IsGenericLambda);
5676     Record.push_back(Lambda.CaptureDefault);
5677     Record.push_back(Lambda.NumCaptures);
5678     Record.push_back(Lambda.NumExplicitCaptures);
5679     Record.push_back(Lambda.ManglingNumber);
5680     AddDeclRef(Lambda.ContextDecl, Record);
5681     AddTypeSourceInfo(Lambda.MethodTyInfo, Record);
5682     for (unsigned I = 0, N = Lambda.NumCaptures; I != N; ++I) {
5683       const LambdaCapture &Capture = Lambda.Captures[I];
5684       AddSourceLocation(Capture.getLocation(), Record);
5685       Record.push_back(Capture.isImplicit());
5686       Record.push_back(Capture.getCaptureKind());
5687       switch (Capture.getCaptureKind()) {
5688       case LCK_This:
5689       case LCK_VLAType:
5690         break;
5691       case LCK_ByCopy:
5692       case LCK_ByRef:
5693         VarDecl *Var =
5694             Capture.capturesVariable() ? Capture.getCapturedVar() : nullptr;
5695         AddDeclRef(Var, Record);
5696         AddSourceLocation(Capture.isPackExpansion() ? Capture.getEllipsisLoc()
5697                                                     : SourceLocation(),
5698                           Record);
5699         break;
5700       }
5701     }
5702   }
5703 }
5704 
5705 void ASTWriter::ReaderInitialized(ASTReader *Reader) {
5706   assert(Reader && "Cannot remove chain");
5707   assert((!Chain || Chain == Reader) && "Cannot replace chain");
5708   assert(FirstDeclID == NextDeclID &&
5709          FirstTypeID == NextTypeID &&
5710          FirstIdentID == NextIdentID &&
5711          FirstMacroID == NextMacroID &&
5712          FirstSubmoduleID == NextSubmoduleID &&
5713          FirstSelectorID == NextSelectorID &&
5714          "Setting chain after writing has started.");
5715 
5716   Chain = Reader;
5717 
5718   FirstDeclID = NUM_PREDEF_DECL_IDS + Chain->getTotalNumDecls();
5719   FirstTypeID = NUM_PREDEF_TYPE_IDS + Chain->getTotalNumTypes();
5720   FirstIdentID = NUM_PREDEF_IDENT_IDS + Chain->getTotalNumIdentifiers();
5721   FirstMacroID = NUM_PREDEF_MACRO_IDS + Chain->getTotalNumMacros();
5722   FirstSubmoduleID = NUM_PREDEF_SUBMODULE_IDS + Chain->getTotalNumSubmodules();
5723   FirstSelectorID = NUM_PREDEF_SELECTOR_IDS + Chain->getTotalNumSelectors();
5724   NextDeclID = FirstDeclID;
5725   NextTypeID = FirstTypeID;
5726   NextIdentID = FirstIdentID;
5727   NextMacroID = FirstMacroID;
5728   NextSelectorID = FirstSelectorID;
5729   NextSubmoduleID = FirstSubmoduleID;
5730 }
5731 
5732 void ASTWriter::IdentifierRead(IdentID ID, IdentifierInfo *II) {
5733   // Always keep the highest ID. See \p TypeRead() for more information.
5734   IdentID &StoredID = IdentifierIDs[II];
5735   if (ID > StoredID)
5736     StoredID = ID;
5737 }
5738 
5739 void ASTWriter::MacroRead(serialization::MacroID ID, MacroInfo *MI) {
5740   // Always keep the highest ID. See \p TypeRead() for more information.
5741   MacroID &StoredID = MacroIDs[MI];
5742   if (ID > StoredID)
5743     StoredID = ID;
5744 }
5745 
5746 void ASTWriter::TypeRead(TypeIdx Idx, QualType T) {
5747   // Always take the highest-numbered type index. This copes with an interesting
5748   // case for chained AST writing where we schedule writing the type and then,
5749   // later, deserialize the type from another AST. In this case, we want to
5750   // keep the higher-numbered entry so that we can properly write it out to
5751   // the AST file.
5752   TypeIdx &StoredIdx = TypeIdxs[T];
5753   if (Idx.getIndex() >= StoredIdx.getIndex())
5754     StoredIdx = Idx;
5755 }
5756 
5757 void ASTWriter::SelectorRead(SelectorID ID, Selector S) {
5758   // Always keep the highest ID. See \p TypeRead() for more information.
5759   SelectorID &StoredID = SelectorIDs[S];
5760   if (ID > StoredID)
5761     StoredID = ID;
5762 }
5763 
5764 void ASTWriter::MacroDefinitionRead(serialization::PreprocessedEntityID ID,
5765                                     MacroDefinition *MD) {
5766   assert(MacroDefinitions.find(MD) == MacroDefinitions.end());
5767   MacroDefinitions[MD] = ID;
5768 }
5769 
5770 void ASTWriter::ModuleRead(serialization::SubmoduleID ID, Module *Mod) {
5771   assert(SubmoduleIDs.find(Mod) == SubmoduleIDs.end());
5772   SubmoduleIDs[Mod] = ID;
5773 }
5774 
5775 void ASTWriter::CompletedTagDefinition(const TagDecl *D) {
5776   assert(D->isCompleteDefinition());
5777   assert(!WritingAST && "Already writing the AST!");
5778   if (const CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(D)) {
5779     // We are interested when a PCH decl is modified.
5780     if (RD->isFromASTFile()) {
5781       // A forward reference was mutated into a definition. Rewrite it.
5782       // FIXME: This happens during template instantiation, should we
5783       // have created a new definition decl instead ?
5784       assert(isTemplateInstantiation(RD->getTemplateSpecializationKind()) &&
5785              "completed a tag from another module but not by instantiation?");
5786       DeclUpdates[RD].push_back(
5787           DeclUpdate(UPD_CXX_INSTANTIATED_CLASS_DEFINITION));
5788     }
5789   }
5790 }
5791 
5792 void ASTWriter::AddedVisibleDecl(const DeclContext *DC, const Decl *D) {
5793   // TU and namespaces are handled elsewhere.
5794   if (isa<TranslationUnitDecl>(DC) || isa<NamespaceDecl>(DC))
5795     return;
5796 
5797   if (!(!D->isFromASTFile() && cast<Decl>(DC)->isFromASTFile()))
5798     return; // Not a source decl added to a DeclContext from PCH.
5799 
5800   assert(!getDefinitiveDeclContext(DC) && "DeclContext not definitive!");
5801   assert(!WritingAST && "Already writing the AST!");
5802   AddUpdatedDeclContext(DC);
5803   UpdatingVisibleDecls.push_back(D);
5804 }
5805 
5806 void ASTWriter::AddedCXXImplicitMember(const CXXRecordDecl *RD, const Decl *D) {
5807   assert(D->isImplicit());
5808   if (!(!D->isFromASTFile() && RD->isFromASTFile()))
5809     return; // Not a source member added to a class from PCH.
5810   if (!isa<CXXMethodDecl>(D))
5811     return; // We are interested in lazily declared implicit methods.
5812 
5813   // A decl coming from PCH was modified.
5814   assert(RD->isCompleteDefinition());
5815   assert(!WritingAST && "Already writing the AST!");
5816   DeclUpdates[RD].push_back(DeclUpdate(UPD_CXX_ADDED_IMPLICIT_MEMBER, D));
5817 }
5818 
5819 void ASTWriter::AddedCXXTemplateSpecialization(const ClassTemplateDecl *TD,
5820                                      const ClassTemplateSpecializationDecl *D) {
5821   // The specializations set is kept in the canonical template.
5822   TD = TD->getCanonicalDecl();
5823   if (!(!D->isFromASTFile() && TD->isFromASTFile()))
5824     return; // Not a source specialization added to a template from PCH.
5825 
5826   assert(!WritingAST && "Already writing the AST!");
5827   DeclUpdates[TD].push_back(DeclUpdate(UPD_CXX_ADDED_TEMPLATE_SPECIALIZATION,
5828                                        D));
5829 }
5830 
5831 void ASTWriter::AddedCXXTemplateSpecialization(
5832     const VarTemplateDecl *TD, const VarTemplateSpecializationDecl *D) {
5833   // The specializations set is kept in the canonical template.
5834   TD = TD->getCanonicalDecl();
5835   if (!(!D->isFromASTFile() && TD->isFromASTFile()))
5836     return; // Not a source specialization added to a template from PCH.
5837 
5838   assert(!WritingAST && "Already writing the AST!");
5839   DeclUpdates[TD].push_back(DeclUpdate(UPD_CXX_ADDED_TEMPLATE_SPECIALIZATION,
5840                                        D));
5841 }
5842 
5843 void ASTWriter::AddedCXXTemplateSpecialization(const FunctionTemplateDecl *TD,
5844                                                const FunctionDecl *D) {
5845   // The specializations set is kept in the canonical template.
5846   TD = TD->getCanonicalDecl();
5847   if (!(!D->isFromASTFile() && TD->isFromASTFile()))
5848     return; // Not a source specialization added to a template from PCH.
5849 
5850   assert(!WritingAST && "Already writing the AST!");
5851   DeclUpdates[TD].push_back(DeclUpdate(UPD_CXX_ADDED_TEMPLATE_SPECIALIZATION,
5852                                        D));
5853 }
5854 
5855 void ASTWriter::ResolvedExceptionSpec(const FunctionDecl *FD) {
5856   assert(!WritingAST && "Already writing the AST!");
5857   FD = FD->getCanonicalDecl();
5858   if (!FD->isFromASTFile())
5859     return; // Not a function declared in PCH and defined outside.
5860 
5861   DeclUpdates[FD].push_back(UPD_CXX_RESOLVED_EXCEPTION_SPEC);
5862 }
5863 
5864 void ASTWriter::DeducedReturnType(const FunctionDecl *FD, QualType ReturnType) {
5865   assert(!WritingAST && "Already writing the AST!");
5866   FD = FD->getCanonicalDecl();
5867   if (!FD->isFromASTFile())
5868     return; // Not a function declared in PCH and defined outside.
5869 
5870   DeclUpdates[FD].push_back(DeclUpdate(UPD_CXX_DEDUCED_RETURN_TYPE, ReturnType));
5871 }
5872 
5873 void ASTWriter::CompletedImplicitDefinition(const FunctionDecl *D) {
5874   assert(!WritingAST && "Already writing the AST!");
5875   if (!D->isFromASTFile())
5876     return; // Declaration not imported from PCH.
5877 
5878   // Implicit function decl from a PCH was defined.
5879   DeclUpdates[D].push_back(DeclUpdate(UPD_CXX_ADDED_FUNCTION_DEFINITION));
5880 }
5881 
5882 void ASTWriter::FunctionDefinitionInstantiated(const FunctionDecl *D) {
5883   assert(!WritingAST && "Already writing the AST!");
5884   if (!D->isFromASTFile())
5885     return;
5886 
5887   DeclUpdates[D].push_back(
5888       DeclUpdate(UPD_CXX_ADDED_FUNCTION_DEFINITION));
5889 }
5890 
5891 void ASTWriter::StaticDataMemberInstantiated(const VarDecl *D) {
5892   assert(!WritingAST && "Already writing the AST!");
5893   if (!D->isFromASTFile())
5894     return;
5895 
5896   // Since the actual instantiation is delayed, this really means that we need
5897   // to update the instantiation location.
5898   DeclUpdates[D].push_back(
5899       DeclUpdate(UPD_CXX_INSTANTIATED_STATIC_DATA_MEMBER,
5900        D->getMemberSpecializationInfo()->getPointOfInstantiation()));
5901 }
5902 
5903 void ASTWriter::AddedObjCCategoryToInterface(const ObjCCategoryDecl *CatD,
5904                                              const ObjCInterfaceDecl *IFD) {
5905   assert(!WritingAST && "Already writing the AST!");
5906   if (!IFD->isFromASTFile())
5907     return; // Declaration not imported from PCH.
5908 
5909   assert(IFD->getDefinition() && "Category on a class without a definition?");
5910   ObjCClassesWithCategories.insert(
5911     const_cast<ObjCInterfaceDecl *>(IFD->getDefinition()));
5912 }
5913 
5914 
5915 void ASTWriter::AddedObjCPropertyInClassExtension(const ObjCPropertyDecl *Prop,
5916                                           const ObjCPropertyDecl *OrigProp,
5917                                           const ObjCCategoryDecl *ClassExt) {
5918   const ObjCInterfaceDecl *D = ClassExt->getClassInterface();
5919   if (!D)
5920     return;
5921 
5922   assert(!WritingAST && "Already writing the AST!");
5923   if (!D->isFromASTFile())
5924     return; // Declaration not imported from PCH.
5925 
5926   RewriteDecl(D);
5927 }
5928 
5929 void ASTWriter::DeclarationMarkedUsed(const Decl *D) {
5930   assert(!WritingAST && "Already writing the AST!");
5931   if (!D->isFromASTFile())
5932     return;
5933 
5934   DeclUpdates[D].push_back(DeclUpdate(UPD_DECL_MARKED_USED));
5935 }
5936 
5937 void ASTWriter::DeclarationMarkedOpenMPThreadPrivate(const Decl *D) {
5938   assert(!WritingAST && "Already writing the AST!");
5939   if (!D->isFromASTFile())
5940     return;
5941 
5942   DeclUpdates[D].push_back(DeclUpdate(UPD_DECL_MARKED_OPENMP_THREADPRIVATE));
5943 }
5944