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